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bcea3f96 | 1 | // SPDX-License-Identifier: GPL-2.0 |
16444a8a ACM |
2 | /* |
3 | * Infrastructure for profiling code inserted by 'gcc -pg'. | |
4 | * | |
5 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> | |
6 | * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com> | |
7 | * | |
8 | * Originally ported from the -rt patch by: | |
9 | * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com> | |
10 | * | |
11 | * Based on code in the latency_tracer, that is: | |
12 | * | |
13 | * Copyright (C) 2004-2006 Ingo Molnar | |
6d49e352 | 14 | * Copyright (C) 2004 Nadia Yvette Chambers |
16444a8a ACM |
15 | */ |
16 | ||
3d083395 SR |
17 | #include <linux/stop_machine.h> |
18 | #include <linux/clocksource.h> | |
29930025 | 19 | #include <linux/sched/task.h> |
3d083395 | 20 | #include <linux/kallsyms.h> |
17911ff3 | 21 | #include <linux/security.h> |
5072c59f | 22 | #include <linux/seq_file.h> |
8434dc93 | 23 | #include <linux/tracefs.h> |
3d083395 | 24 | #include <linux/hardirq.h> |
2d8b820b | 25 | #include <linux/kthread.h> |
5072c59f | 26 | #include <linux/uaccess.h> |
5855fead | 27 | #include <linux/bsearch.h> |
56d82e00 | 28 | #include <linux/module.h> |
2d8b820b | 29 | #include <linux/ftrace.h> |
b0fc494f | 30 | #include <linux/sysctl.h> |
5a0e3ad6 | 31 | #include <linux/slab.h> |
5072c59f | 32 | #include <linux/ctype.h> |
68950619 | 33 | #include <linux/sort.h> |
3d083395 | 34 | #include <linux/list.h> |
59df055f | 35 | #include <linux/hash.h> |
3f379b03 | 36 | #include <linux/rcupdate.h> |
fabe38ab | 37 | #include <linux/kprobes.h> |
3d083395 | 38 | |
ad8d75ff | 39 | #include <trace/events/sched.h> |
8aef2d28 | 40 | |
b80f0f6c | 41 | #include <asm/sections.h> |
2af15d6a | 42 | #include <asm/setup.h> |
395a59d0 | 43 | |
3306fc4a | 44 | #include "ftrace_internal.h" |
0706f1c4 | 45 | #include "trace_output.h" |
bac429f0 | 46 | #include "trace_stat.h" |
16444a8a | 47 | |
b39181f7 SRG |
48 | #define FTRACE_INVALID_FUNCTION "__ftrace_invalid_address__" |
49 | ||
6912896e | 50 | #define FTRACE_WARN_ON(cond) \ |
0778d9ad SR |
51 | ({ \ |
52 | int ___r = cond; \ | |
53 | if (WARN_ON(___r)) \ | |
6912896e | 54 | ftrace_kill(); \ |
0778d9ad SR |
55 | ___r; \ |
56 | }) | |
6912896e SR |
57 | |
58 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
0778d9ad SR |
59 | ({ \ |
60 | int ___r = cond; \ | |
61 | if (WARN_ON_ONCE(___r)) \ | |
6912896e | 62 | ftrace_kill(); \ |
0778d9ad SR |
63 | ___r; \ |
64 | }) | |
6912896e | 65 | |
8fc0c701 | 66 | /* hash bits for specific function selection */ |
33dc9b12 SR |
67 | #define FTRACE_HASH_DEFAULT_BITS 10 |
68 | #define FTRACE_HASH_MAX_BITS 12 | |
8fc0c701 | 69 | |
f04f24fb | 70 | #ifdef CONFIG_DYNAMIC_FTRACE |
33b7f99c SRRH |
71 | #define INIT_OPS_HASH(opsname) \ |
72 | .func_hash = &opsname.local_hash, \ | |
73 | .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock), | |
f04f24fb | 74 | #else |
33b7f99c | 75 | #define INIT_OPS_HASH(opsname) |
f04f24fb MH |
76 | #endif |
77 | ||
a0572f68 SRV |
78 | enum { |
79 | FTRACE_MODIFY_ENABLE_FL = (1 << 0), | |
80 | FTRACE_MODIFY_MAY_SLEEP_FL = (1 << 1), | |
81 | }; | |
82 | ||
3306fc4a | 83 | struct ftrace_ops ftrace_list_end __read_mostly = { |
2f5f6ad9 | 84 | .func = ftrace_stub, |
a25d036d | 85 | .flags = FTRACE_OPS_FL_STUB, |
33b7f99c | 86 | INIT_OPS_HASH(ftrace_list_end) |
2f5f6ad9 SR |
87 | }; |
88 | ||
4eebcc81 SR |
89 | /* ftrace_enabled is a method to turn ftrace on or off */ |
90 | int ftrace_enabled __read_mostly; | |
5d79fa0d | 91 | static int __maybe_unused last_ftrace_enabled; |
b0fc494f | 92 | |
2f5f6ad9 SR |
93 | /* Current function tracing op */ |
94 | struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end; | |
405e1d83 SRRH |
95 | /* What to set function_trace_op to */ |
96 | static struct ftrace_ops *set_function_trace_op; | |
60a7ecf4 | 97 | |
345ddcc8 | 98 | static bool ftrace_pids_enabled(struct ftrace_ops *ops) |
e3eea140 | 99 | { |
345ddcc8 SRRH |
100 | struct trace_array *tr; |
101 | ||
102 | if (!(ops->flags & FTRACE_OPS_FL_PID) || !ops->private) | |
103 | return false; | |
104 | ||
105 | tr = ops->private; | |
106 | ||
b3b1e6ed | 107 | return tr->function_pids != NULL || tr->function_no_pids != NULL; |
e3eea140 SRRH |
108 | } |
109 | ||
110 | static void ftrace_update_trampoline(struct ftrace_ops *ops); | |
111 | ||
4eebcc81 SR |
112 | /* |
113 | * ftrace_disabled is set when an anomaly is discovered. | |
114 | * ftrace_disabled is much stronger than ftrace_enabled. | |
115 | */ | |
116 | static int ftrace_disabled __read_mostly; | |
117 | ||
3306fc4a | 118 | DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 119 | |
3306fc4a | 120 | struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = &ftrace_list_end; |
16444a8a | 121 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
3306fc4a | 122 | struct ftrace_ops global_ops; |
16444a8a | 123 | |
50c69781 | 124 | /* Defined by vmlinux.lds.h see the comment above arch_ftrace_ops_list_func for details */ |
34cdd18b SRV |
125 | void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, |
126 | struct ftrace_ops *op, struct ftrace_regs *fregs); | |
b848914c | 127 | |
cbad0fb2 MR |
128 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS |
129 | /* | |
130 | * Stub used to invoke the list ops without requiring a separate trampoline. | |
131 | */ | |
132 | const struct ftrace_ops ftrace_list_ops = { | |
133 | .func = ftrace_ops_list_func, | |
134 | .flags = FTRACE_OPS_FL_STUB, | |
135 | }; | |
136 | ||
137 | static void ftrace_ops_nop_func(unsigned long ip, unsigned long parent_ip, | |
138 | struct ftrace_ops *op, | |
139 | struct ftrace_regs *fregs) | |
140 | { | |
141 | /* do nothing */ | |
142 | } | |
143 | ||
144 | /* | |
145 | * Stub used when a call site is disabled. May be called transiently by threads | |
146 | * which have made it into ftrace_caller but haven't yet recovered the ops at | |
147 | * the point the call site is disabled. | |
148 | */ | |
149 | const struct ftrace_ops ftrace_nop_ops = { | |
150 | .func = ftrace_ops_nop_func, | |
151 | .flags = FTRACE_OPS_FL_STUB, | |
152 | }; | |
153 | #endif | |
154 | ||
f04f24fb MH |
155 | static inline void ftrace_ops_init(struct ftrace_ops *ops) |
156 | { | |
157 | #ifdef CONFIG_DYNAMIC_FTRACE | |
158 | if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) { | |
33b7f99c SRRH |
159 | mutex_init(&ops->local_hash.regex_lock); |
160 | ops->func_hash = &ops->local_hash; | |
f04f24fb MH |
161 | ops->flags |= FTRACE_OPS_FL_INITIALIZED; |
162 | } | |
163 | #endif | |
164 | } | |
165 | ||
2f5f6ad9 | 166 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, |
d19ad077 | 167 | struct ftrace_ops *op, struct ftrace_regs *fregs) |
df4fc315 | 168 | { |
345ddcc8 | 169 | struct trace_array *tr = op->private; |
717e3f5e | 170 | int pid; |
345ddcc8 | 171 | |
717e3f5e SRV |
172 | if (tr) { |
173 | pid = this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid); | |
174 | if (pid == FTRACE_PID_IGNORE) | |
175 | return; | |
176 | if (pid != FTRACE_PID_TRACE && | |
177 | pid != current->pid) | |
178 | return; | |
179 | } | |
df4fc315 | 180 | |
d19ad077 | 181 | op->saved_func(ip, parent_ip, op, fregs); |
df4fc315 SR |
182 | } |
183 | ||
405e1d83 SRRH |
184 | static void ftrace_sync_ipi(void *data) |
185 | { | |
186 | /* Probably not needed, but do it anyway */ | |
187 | smp_rmb(); | |
188 | } | |
189 | ||
00ccbf2f SRRH |
190 | static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops) |
191 | { | |
192 | /* | |
78a01feb | 193 | * If this is a dynamic or RCU ops, or we force list func, |
00ccbf2f SRRH |
194 | * then it needs to call the list anyway. |
195 | */ | |
b3a88803 PZ |
196 | if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_RCU) || |
197 | FTRACE_FORCE_LIST_FUNC) | |
00ccbf2f SRRH |
198 | return ftrace_ops_list_func; |
199 | ||
200 | return ftrace_ops_get_func(ops); | |
201 | } | |
202 | ||
2b499381 SR |
203 | static void update_ftrace_function(void) |
204 | { | |
205 | ftrace_func_t func; | |
206 | ||
f7aad4e1 SRRH |
207 | /* |
208 | * Prepare the ftrace_ops that the arch callback will use. | |
209 | * If there's only one ftrace_ops registered, the ftrace_ops_list | |
210 | * will point to the ops we want. | |
211 | */ | |
f86f4180 CZ |
212 | set_function_trace_op = rcu_dereference_protected(ftrace_ops_list, |
213 | lockdep_is_held(&ftrace_lock)); | |
f7aad4e1 SRRH |
214 | |
215 | /* If there's no ftrace_ops registered, just call the stub function */ | |
f86f4180 | 216 | if (set_function_trace_op == &ftrace_list_end) { |
f7aad4e1 SRRH |
217 | func = ftrace_stub; |
218 | ||
cdbe61bf SR |
219 | /* |
220 | * If we are at the end of the list and this ops is | |
4740974a SR |
221 | * recursion safe and not dynamic and the arch supports passing ops, |
222 | * then have the mcount trampoline call the function directly. | |
cdbe61bf | 223 | */ |
f86f4180 CZ |
224 | } else if (rcu_dereference_protected(ftrace_ops_list->next, |
225 | lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { | |
00ccbf2f | 226 | func = ftrace_ops_get_list_func(ftrace_ops_list); |
f7aad4e1 | 227 | |
2f5f6ad9 SR |
228 | } else { |
229 | /* Just use the default ftrace_ops */ | |
405e1d83 | 230 | set_function_trace_op = &ftrace_list_end; |
b848914c | 231 | func = ftrace_ops_list_func; |
2f5f6ad9 | 232 | } |
2b499381 | 233 | |
5f8bf2d2 SRRH |
234 | update_function_graph_func(); |
235 | ||
405e1d83 SRRH |
236 | /* If there's no change, then do nothing more here */ |
237 | if (ftrace_trace_function == func) | |
238 | return; | |
239 | ||
240 | /* | |
241 | * If we are using the list function, it doesn't care | |
242 | * about the function_trace_ops. | |
243 | */ | |
244 | if (func == ftrace_ops_list_func) { | |
245 | ftrace_trace_function = func; | |
246 | /* | |
247 | * Don't even bother setting function_trace_ops, | |
248 | * it would be racy to do so anyway. | |
249 | */ | |
250 | return; | |
251 | } | |
252 | ||
253 | #ifndef CONFIG_DYNAMIC_FTRACE | |
254 | /* | |
255 | * For static tracing, we need to be a bit more careful. | |
256 | * The function change takes affect immediately. Thus, | |
fdda88d3 | 257 | * we need to coordinate the setting of the function_trace_ops |
405e1d83 SRRH |
258 | * with the setting of the ftrace_trace_function. |
259 | * | |
260 | * Set the function to the list ops, which will call the | |
261 | * function we want, albeit indirectly, but it handles the | |
262 | * ftrace_ops and doesn't depend on function_trace_op. | |
263 | */ | |
264 | ftrace_trace_function = ftrace_ops_list_func; | |
265 | /* | |
266 | * Make sure all CPUs see this. Yes this is slow, but static | |
267 | * tracing is slow and nasty to have enabled. | |
268 | */ | |
e5a971d7 | 269 | synchronize_rcu_tasks_rude(); |
405e1d83 SRRH |
270 | /* Now all cpus are using the list ops. */ |
271 | function_trace_op = set_function_trace_op; | |
272 | /* Make sure the function_trace_op is visible on all CPUs */ | |
273 | smp_wmb(); | |
274 | /* Nasty way to force a rmb on all cpus */ | |
275 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
276 | /* OK, we are all set to update the ftrace_trace_function now! */ | |
277 | #endif /* !CONFIG_DYNAMIC_FTRACE */ | |
278 | ||
491d0dcf | 279 | ftrace_trace_function = func; |
491d0dcf SR |
280 | } |
281 | ||
f86f4180 CZ |
282 | static void add_ftrace_ops(struct ftrace_ops __rcu **list, |
283 | struct ftrace_ops *ops) | |
3d083395 | 284 | { |
f86f4180 CZ |
285 | rcu_assign_pointer(ops->next, *list); |
286 | ||
16444a8a | 287 | /* |
b848914c | 288 | * We are entering ops into the list but another |
16444a8a ACM |
289 | * CPU might be walking that list. We need to make sure |
290 | * the ops->next pointer is valid before another CPU sees | |
b848914c | 291 | * the ops pointer included into the list. |
16444a8a | 292 | */ |
2b499381 | 293 | rcu_assign_pointer(*list, ops); |
16444a8a ACM |
294 | } |
295 | ||
f86f4180 CZ |
296 | static int remove_ftrace_ops(struct ftrace_ops __rcu **list, |
297 | struct ftrace_ops *ops) | |
16444a8a | 298 | { |
16444a8a | 299 | struct ftrace_ops **p; |
16444a8a ACM |
300 | |
301 | /* | |
3d083395 SR |
302 | * If we are removing the last function, then simply point |
303 | * to the ftrace_stub. | |
16444a8a | 304 | */ |
f86f4180 CZ |
305 | if (rcu_dereference_protected(*list, |
306 | lockdep_is_held(&ftrace_lock)) == ops && | |
307 | rcu_dereference_protected(ops->next, | |
308 | lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { | |
2b499381 | 309 | *list = &ftrace_list_end; |
e6ea44e9 | 310 | return 0; |
16444a8a ACM |
311 | } |
312 | ||
2b499381 | 313 | for (p = list; *p != &ftrace_list_end; p = &(*p)->next) |
16444a8a ACM |
314 | if (*p == ops) |
315 | break; | |
316 | ||
e6ea44e9 SR |
317 | if (*p != ops) |
318 | return -1; | |
16444a8a ACM |
319 | |
320 | *p = (*p)->next; | |
2b499381 SR |
321 | return 0; |
322 | } | |
16444a8a | 323 | |
f3bea491 SRRH |
324 | static void ftrace_update_trampoline(struct ftrace_ops *ops); |
325 | ||
3306fc4a | 326 | int __register_ftrace_function(struct ftrace_ops *ops) |
2b499381 | 327 | { |
591dffda SRRH |
328 | if (ops->flags & FTRACE_OPS_FL_DELETED) |
329 | return -EINVAL; | |
330 | ||
b848914c SR |
331 | if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) |
332 | return -EBUSY; | |
333 | ||
06aeaaea | 334 | #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
08f6fba5 SR |
335 | /* |
336 | * If the ftrace_ops specifies SAVE_REGS, then it only can be used | |
337 | * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set. | |
338 | * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant. | |
339 | */ | |
340 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS && | |
341 | !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)) | |
342 | return -EINVAL; | |
343 | ||
344 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED) | |
345 | ops->flags |= FTRACE_OPS_FL_SAVE_REGS; | |
346 | #endif | |
7162431d MB |
347 | if (!ftrace_enabled && (ops->flags & FTRACE_OPS_FL_PERMANENT)) |
348 | return -EBUSY; | |
08f6fba5 | 349 | |
a20deb3a | 350 | if (!is_kernel_core_data((unsigned long)ops)) |
cdbe61bf SR |
351 | ops->flags |= FTRACE_OPS_FL_DYNAMIC; |
352 | ||
ba27f2bc | 353 | add_ftrace_ops(&ftrace_ops_list, ops); |
b848914c | 354 | |
e3eea140 SRRH |
355 | /* Always save the function, and reset at unregistering */ |
356 | ops->saved_func = ops->func; | |
357 | ||
345ddcc8 | 358 | if (ftrace_pids_enabled(ops)) |
e3eea140 SRRH |
359 | ops->func = ftrace_pid_func; |
360 | ||
f3bea491 SRRH |
361 | ftrace_update_trampoline(ops); |
362 | ||
2b499381 SR |
363 | if (ftrace_enabled) |
364 | update_ftrace_function(); | |
365 | ||
366 | return 0; | |
367 | } | |
368 | ||
3306fc4a | 369 | int __unregister_ftrace_function(struct ftrace_ops *ops) |
2b499381 SR |
370 | { |
371 | int ret; | |
372 | ||
b848914c SR |
373 | if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) |
374 | return -EBUSY; | |
375 | ||
ba27f2bc | 376 | ret = remove_ftrace_ops(&ftrace_ops_list, ops); |
b848914c | 377 | |
2b499381 SR |
378 | if (ret < 0) |
379 | return ret; | |
b848914c | 380 | |
491d0dcf SR |
381 | if (ftrace_enabled) |
382 | update_ftrace_function(); | |
16444a8a | 383 | |
e3eea140 SRRH |
384 | ops->func = ops->saved_func; |
385 | ||
e6ea44e9 | 386 | return 0; |
3d083395 SR |
387 | } |
388 | ||
df4fc315 SR |
389 | static void ftrace_update_pid_func(void) |
390 | { | |
e3eea140 SRRH |
391 | struct ftrace_ops *op; |
392 | ||
491d0dcf | 393 | /* Only do something if we are tracing something */ |
df4fc315 | 394 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 395 | return; |
df4fc315 | 396 | |
e3eea140 SRRH |
397 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
398 | if (op->flags & FTRACE_OPS_FL_PID) { | |
345ddcc8 SRRH |
399 | op->func = ftrace_pids_enabled(op) ? |
400 | ftrace_pid_func : op->saved_func; | |
e3eea140 SRRH |
401 | ftrace_update_trampoline(op); |
402 | } | |
403 | } while_for_each_ftrace_op(op); | |
404 | ||
491d0dcf | 405 | update_ftrace_function(); |
df4fc315 SR |
406 | } |
407 | ||
493762fc SR |
408 | #ifdef CONFIG_FUNCTION_PROFILER |
409 | struct ftrace_profile { | |
410 | struct hlist_node node; | |
411 | unsigned long ip; | |
412 | unsigned long counter; | |
0706f1c4 SR |
413 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
414 | unsigned long long time; | |
e330b3bc | 415 | unsigned long long time_squared; |
0706f1c4 | 416 | #endif |
8fc0c701 SR |
417 | }; |
418 | ||
493762fc SR |
419 | struct ftrace_profile_page { |
420 | struct ftrace_profile_page *next; | |
421 | unsigned long index; | |
422 | struct ftrace_profile records[]; | |
d61f82d0 SR |
423 | }; |
424 | ||
cafb168a SR |
425 | struct ftrace_profile_stat { |
426 | atomic_t disabled; | |
427 | struct hlist_head *hash; | |
428 | struct ftrace_profile_page *pages; | |
429 | struct ftrace_profile_page *start; | |
430 | struct tracer_stat stat; | |
431 | }; | |
432 | ||
493762fc SR |
433 | #define PROFILE_RECORDS_SIZE \ |
434 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 435 | |
493762fc SR |
436 | #define PROFILES_PER_PAGE \ |
437 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 438 | |
fb9fb015 SR |
439 | static int ftrace_profile_enabled __read_mostly; |
440 | ||
441 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
442 | static DEFINE_MUTEX(ftrace_profile_lock); |
443 | ||
cafb168a | 444 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc | 445 | |
20079ebe NK |
446 | #define FTRACE_PROFILE_HASH_BITS 10 |
447 | #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS) | |
493762fc | 448 | |
bac429f0 SR |
449 | static void * |
450 | function_stat_next(void *v, int idx) | |
451 | { | |
493762fc SR |
452 | struct ftrace_profile *rec = v; |
453 | struct ftrace_profile_page *pg; | |
bac429f0 | 454 | |
493762fc | 455 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
456 | |
457 | again: | |
0296e425 LZ |
458 | if (idx != 0) |
459 | rec++; | |
460 | ||
bac429f0 SR |
461 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
462 | pg = pg->next; | |
463 | if (!pg) | |
464 | return NULL; | |
465 | rec = &pg->records[0]; | |
493762fc SR |
466 | if (!rec->counter) |
467 | goto again; | |
bac429f0 SR |
468 | } |
469 | ||
bac429f0 SR |
470 | return rec; |
471 | } | |
472 | ||
473 | static void *function_stat_start(struct tracer_stat *trace) | |
474 | { | |
cafb168a SR |
475 | struct ftrace_profile_stat *stat = |
476 | container_of(trace, struct ftrace_profile_stat, stat); | |
477 | ||
478 | if (!stat || !stat->start) | |
479 | return NULL; | |
480 | ||
481 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
482 | } |
483 | ||
0706f1c4 SR |
484 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
485 | /* function graph compares on total time */ | |
80042c8f | 486 | static int function_stat_cmp(const void *p1, const void *p2) |
0706f1c4 | 487 | { |
80042c8f AS |
488 | const struct ftrace_profile *a = p1; |
489 | const struct ftrace_profile *b = p2; | |
0706f1c4 SR |
490 | |
491 | if (a->time < b->time) | |
492 | return -1; | |
493 | if (a->time > b->time) | |
494 | return 1; | |
495 | else | |
496 | return 0; | |
497 | } | |
498 | #else | |
499 | /* not function graph compares against hits */ | |
80042c8f | 500 | static int function_stat_cmp(const void *p1, const void *p2) |
bac429f0 | 501 | { |
80042c8f AS |
502 | const struct ftrace_profile *a = p1; |
503 | const struct ftrace_profile *b = p2; | |
bac429f0 SR |
504 | |
505 | if (a->counter < b->counter) | |
506 | return -1; | |
507 | if (a->counter > b->counter) | |
508 | return 1; | |
509 | else | |
510 | return 0; | |
511 | } | |
0706f1c4 | 512 | #endif |
bac429f0 SR |
513 | |
514 | static int function_stat_headers(struct seq_file *m) | |
515 | { | |
0706f1c4 | 516 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
fa6f0cc7 RV |
517 | seq_puts(m, " Function " |
518 | "Hit Time Avg s^2\n" | |
519 | " -------- " | |
520 | "--- ---- --- ---\n"); | |
0706f1c4 | 521 | #else |
fa6f0cc7 RV |
522 | seq_puts(m, " Function Hit\n" |
523 | " -------- ---\n"); | |
0706f1c4 | 524 | #endif |
bac429f0 SR |
525 | return 0; |
526 | } | |
527 | ||
528 | static int function_stat_show(struct seq_file *m, void *v) | |
529 | { | |
493762fc | 530 | struct ftrace_profile *rec = v; |
bac429f0 | 531 | char str[KSYM_SYMBOL_LEN]; |
3aaba20f | 532 | int ret = 0; |
0706f1c4 | 533 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
534 | static struct trace_seq s; |
535 | unsigned long long avg; | |
e330b3bc | 536 | unsigned long long stddev; |
0706f1c4 | 537 | #endif |
3aaba20f LZ |
538 | mutex_lock(&ftrace_profile_lock); |
539 | ||
540 | /* we raced with function_profile_reset() */ | |
541 | if (unlikely(rec->counter == 0)) { | |
542 | ret = -EBUSY; | |
543 | goto out; | |
544 | } | |
bac429f0 | 545 | |
8e436ca0 | 546 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e31f7939 | 547 | avg = div64_ul(rec->time, rec->counter); |
8e436ca0 UT |
548 | if (tracing_thresh && (avg < tracing_thresh)) |
549 | goto out; | |
550 | #endif | |
551 | ||
bac429f0 | 552 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
0706f1c4 SR |
553 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
554 | ||
555 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
fa6f0cc7 | 556 | seq_puts(m, " "); |
34886c8b | 557 | |
e330b3bc CD |
558 | /* Sample standard deviation (s^2) */ |
559 | if (rec->counter <= 1) | |
560 | stddev = 0; | |
561 | else { | |
52d85d76 JL |
562 | /* |
563 | * Apply Welford's method: | |
564 | * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2) | |
565 | */ | |
566 | stddev = rec->counter * rec->time_squared - | |
567 | rec->time * rec->time; | |
568 | ||
e330b3bc CD |
569 | /* |
570 | * Divide only 1000 for ns^2 -> us^2 conversion. | |
571 | * trace_print_graph_duration will divide 1000 again. | |
572 | */ | |
e31f7939 WY |
573 | stddev = div64_ul(stddev, |
574 | rec->counter * (rec->counter - 1) * 1000); | |
e330b3bc CD |
575 | } |
576 | ||
34886c8b SR |
577 | trace_seq_init(&s); |
578 | trace_print_graph_duration(rec->time, &s); | |
579 | trace_seq_puts(&s, " "); | |
580 | trace_print_graph_duration(avg, &s); | |
e330b3bc CD |
581 | trace_seq_puts(&s, " "); |
582 | trace_print_graph_duration(stddev, &s); | |
0706f1c4 | 583 | trace_print_seq(m, &s); |
0706f1c4 SR |
584 | #endif |
585 | seq_putc(m, '\n'); | |
3aaba20f LZ |
586 | out: |
587 | mutex_unlock(&ftrace_profile_lock); | |
bac429f0 | 588 | |
3aaba20f | 589 | return ret; |
bac429f0 SR |
590 | } |
591 | ||
cafb168a | 592 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 593 | { |
493762fc | 594 | struct ftrace_profile_page *pg; |
bac429f0 | 595 | |
cafb168a | 596 | pg = stat->pages = stat->start; |
bac429f0 | 597 | |
493762fc SR |
598 | while (pg) { |
599 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
600 | pg->index = 0; | |
601 | pg = pg->next; | |
bac429f0 SR |
602 | } |
603 | ||
cafb168a | 604 | memset(stat->hash, 0, |
493762fc SR |
605 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
606 | } | |
bac429f0 | 607 | |
172f7ba9 | 608 | static int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
609 | { |
610 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
611 | int functions; |
612 | int pages; | |
493762fc | 613 | int i; |
bac429f0 | 614 | |
493762fc | 615 | /* If we already allocated, do nothing */ |
cafb168a | 616 | if (stat->pages) |
493762fc | 617 | return 0; |
bac429f0 | 618 | |
cafb168a SR |
619 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
620 | if (!stat->pages) | |
493762fc | 621 | return -ENOMEM; |
bac429f0 | 622 | |
318e0a73 SR |
623 | #ifdef CONFIG_DYNAMIC_FTRACE |
624 | functions = ftrace_update_tot_cnt; | |
625 | #else | |
626 | /* | |
627 | * We do not know the number of functions that exist because | |
628 | * dynamic tracing is what counts them. With past experience | |
629 | * we have around 20K functions. That should be more than enough. | |
630 | * It is highly unlikely we will execute every function in | |
631 | * the kernel. | |
632 | */ | |
633 | functions = 20000; | |
634 | #endif | |
635 | ||
cafb168a | 636 | pg = stat->start = stat->pages; |
bac429f0 | 637 | |
318e0a73 SR |
638 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
639 | ||
39e30cd1 | 640 | for (i = 1; i < pages; i++) { |
493762fc | 641 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 642 | if (!pg->next) |
318e0a73 | 643 | goto out_free; |
493762fc SR |
644 | pg = pg->next; |
645 | } | |
646 | ||
647 | return 0; | |
318e0a73 SR |
648 | |
649 | out_free: | |
650 | pg = stat->start; | |
651 | while (pg) { | |
652 | unsigned long tmp = (unsigned long)pg; | |
653 | ||
654 | pg = pg->next; | |
655 | free_page(tmp); | |
656 | } | |
657 | ||
318e0a73 SR |
658 | stat->pages = NULL; |
659 | stat->start = NULL; | |
660 | ||
661 | return -ENOMEM; | |
bac429f0 SR |
662 | } |
663 | ||
cafb168a | 664 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 665 | { |
cafb168a | 666 | struct ftrace_profile_stat *stat; |
493762fc | 667 | int size; |
bac429f0 | 668 | |
cafb168a SR |
669 | stat = &per_cpu(ftrace_profile_stats, cpu); |
670 | ||
671 | if (stat->hash) { | |
493762fc | 672 | /* If the profile is already created, simply reset it */ |
cafb168a | 673 | ftrace_profile_reset(stat); |
493762fc SR |
674 | return 0; |
675 | } | |
bac429f0 | 676 | |
493762fc SR |
677 | /* |
678 | * We are profiling all functions, but usually only a few thousand | |
679 | * functions are hit. We'll make a hash of 1024 items. | |
680 | */ | |
681 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 682 | |
6396bb22 | 683 | stat->hash = kcalloc(size, sizeof(struct hlist_head), GFP_KERNEL); |
493762fc | 684 | |
cafb168a | 685 | if (!stat->hash) |
493762fc SR |
686 | return -ENOMEM; |
687 | ||
318e0a73 | 688 | /* Preallocate the function profiling pages */ |
cafb168a SR |
689 | if (ftrace_profile_pages_init(stat) < 0) { |
690 | kfree(stat->hash); | |
691 | stat->hash = NULL; | |
493762fc SR |
692 | return -ENOMEM; |
693 | } | |
694 | ||
695 | return 0; | |
bac429f0 SR |
696 | } |
697 | ||
cafb168a SR |
698 | static int ftrace_profile_init(void) |
699 | { | |
700 | int cpu; | |
701 | int ret = 0; | |
702 | ||
c4602c1c | 703 | for_each_possible_cpu(cpu) { |
cafb168a SR |
704 | ret = ftrace_profile_init_cpu(cpu); |
705 | if (ret) | |
706 | break; | |
707 | } | |
708 | ||
709 | return ret; | |
710 | } | |
711 | ||
493762fc | 712 | /* interrupts must be disabled */ |
cafb168a SR |
713 | static struct ftrace_profile * |
714 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 715 | { |
493762fc | 716 | struct ftrace_profile *rec; |
bac429f0 | 717 | struct hlist_head *hhd; |
bac429f0 SR |
718 | unsigned long key; |
719 | ||
20079ebe | 720 | key = hash_long(ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 721 | hhd = &stat->hash[key]; |
bac429f0 SR |
722 | |
723 | if (hlist_empty(hhd)) | |
724 | return NULL; | |
725 | ||
1bb539ca | 726 | hlist_for_each_entry_rcu_notrace(rec, hhd, node) { |
bac429f0 | 727 | if (rec->ip == ip) |
493762fc SR |
728 | return rec; |
729 | } | |
730 | ||
731 | return NULL; | |
732 | } | |
733 | ||
cafb168a SR |
734 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
735 | struct ftrace_profile *rec) | |
493762fc SR |
736 | { |
737 | unsigned long key; | |
738 | ||
20079ebe | 739 | key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 740 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
741 | } |
742 | ||
318e0a73 SR |
743 | /* |
744 | * The memory is already allocated, this simply finds a new record to use. | |
745 | */ | |
493762fc | 746 | static struct ftrace_profile * |
318e0a73 | 747 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
748 | { |
749 | struct ftrace_profile *rec = NULL; | |
750 | ||
318e0a73 | 751 | /* prevent recursion (from NMIs) */ |
cafb168a | 752 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
753 | goto out; |
754 | ||
493762fc | 755 | /* |
318e0a73 SR |
756 | * Try to find the function again since an NMI |
757 | * could have added it | |
493762fc | 758 | */ |
cafb168a | 759 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 760 | if (rec) |
cafb168a | 761 | goto out; |
493762fc | 762 | |
cafb168a SR |
763 | if (stat->pages->index == PROFILES_PER_PAGE) { |
764 | if (!stat->pages->next) | |
765 | goto out; | |
766 | stat->pages = stat->pages->next; | |
bac429f0 | 767 | } |
493762fc | 768 | |
cafb168a | 769 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 770 | rec->ip = ip; |
cafb168a | 771 | ftrace_add_profile(stat, rec); |
493762fc | 772 | |
bac429f0 | 773 | out: |
cafb168a | 774 | atomic_dec(&stat->disabled); |
bac429f0 SR |
775 | |
776 | return rec; | |
777 | } | |
778 | ||
779 | static void | |
2f5f6ad9 | 780 | function_profile_call(unsigned long ip, unsigned long parent_ip, |
d19ad077 | 781 | struct ftrace_ops *ops, struct ftrace_regs *fregs) |
bac429f0 | 782 | { |
cafb168a | 783 | struct ftrace_profile_stat *stat; |
493762fc | 784 | struct ftrace_profile *rec; |
bac429f0 SR |
785 | unsigned long flags; |
786 | ||
787 | if (!ftrace_profile_enabled) | |
788 | return; | |
789 | ||
790 | local_irq_save(flags); | |
cafb168a | 791 | |
bdffd893 | 792 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 793 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
794 | goto out; |
795 | ||
796 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 797 | if (!rec) { |
318e0a73 | 798 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
799 | if (!rec) |
800 | goto out; | |
801 | } | |
bac429f0 SR |
802 | |
803 | rec->counter++; | |
804 | out: | |
805 | local_irq_restore(flags); | |
806 | } | |
807 | ||
0706f1c4 | 808 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e73e679f SRV |
809 | static bool fgraph_graph_time = true; |
810 | ||
811 | void ftrace_graph_graph_time_control(bool enable) | |
812 | { | |
813 | fgraph_graph_time = enable; | |
814 | } | |
815 | ||
0706f1c4 SR |
816 | static int profile_graph_entry(struct ftrace_graph_ent *trace) |
817 | { | |
b0e21a61 | 818 | struct ftrace_ret_stack *ret_stack; |
8861dd30 | 819 | |
a1e2e31d | 820 | function_profile_call(trace->func, 0, NULL, NULL); |
8861dd30 | 821 | |
a8f0f9e4 SRV |
822 | /* If function graph is shutting down, ret_stack can be NULL */ |
823 | if (!current->ret_stack) | |
824 | return 0; | |
825 | ||
b0e21a61 SRV |
826 | ret_stack = ftrace_graph_get_ret_stack(current, 0); |
827 | if (ret_stack) | |
828 | ret_stack->subtime = 0; | |
8861dd30 | 829 | |
0706f1c4 SR |
830 | return 1; |
831 | } | |
832 | ||
833 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
834 | { | |
b0e21a61 | 835 | struct ftrace_ret_stack *ret_stack; |
cafb168a | 836 | struct ftrace_profile_stat *stat; |
a2a16d6a | 837 | unsigned long long calltime; |
0706f1c4 | 838 | struct ftrace_profile *rec; |
cafb168a | 839 | unsigned long flags; |
0706f1c4 SR |
840 | |
841 | local_irq_save(flags); | |
bdffd893 | 842 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 843 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
844 | goto out; |
845 | ||
37e44bc5 SR |
846 | /* If the calltime was zero'd ignore it */ |
847 | if (!trace->calltime) | |
848 | goto out; | |
849 | ||
a2a16d6a SR |
850 | calltime = trace->rettime - trace->calltime; |
851 | ||
55577204 | 852 | if (!fgraph_graph_time) { |
a2a16d6a SR |
853 | |
854 | /* Append this call time to the parent time to subtract */ | |
b0e21a61 SRV |
855 | ret_stack = ftrace_graph_get_ret_stack(current, 1); |
856 | if (ret_stack) | |
857 | ret_stack->subtime += calltime; | |
a2a16d6a | 858 | |
b0e21a61 SRV |
859 | ret_stack = ftrace_graph_get_ret_stack(current, 0); |
860 | if (ret_stack && ret_stack->subtime < calltime) | |
861 | calltime -= ret_stack->subtime; | |
a2a16d6a SR |
862 | else |
863 | calltime = 0; | |
864 | } | |
865 | ||
cafb168a | 866 | rec = ftrace_find_profiled_func(stat, trace->func); |
e330b3bc | 867 | if (rec) { |
a2a16d6a | 868 | rec->time += calltime; |
e330b3bc CD |
869 | rec->time_squared += calltime * calltime; |
870 | } | |
a2a16d6a | 871 | |
cafb168a | 872 | out: |
0706f1c4 SR |
873 | local_irq_restore(flags); |
874 | } | |
875 | ||
688f7089 SRV |
876 | static struct fgraph_ops fprofiler_ops = { |
877 | .entryfunc = &profile_graph_entry, | |
878 | .retfunc = &profile_graph_return, | |
879 | }; | |
880 | ||
0706f1c4 SR |
881 | static int register_ftrace_profiler(void) |
882 | { | |
688f7089 | 883 | return register_ftrace_graph(&fprofiler_ops); |
0706f1c4 SR |
884 | } |
885 | ||
886 | static void unregister_ftrace_profiler(void) | |
887 | { | |
688f7089 | 888 | unregister_ftrace_graph(&fprofiler_ops); |
0706f1c4 SR |
889 | } |
890 | #else | |
bd38c0e6 | 891 | static struct ftrace_ops ftrace_profile_ops __read_mostly = { |
fb9fb015 | 892 | .func = function_profile_call, |
a25d036d | 893 | .flags = FTRACE_OPS_FL_INITIALIZED, |
33b7f99c | 894 | INIT_OPS_HASH(ftrace_profile_ops) |
bac429f0 SR |
895 | }; |
896 | ||
0706f1c4 SR |
897 | static int register_ftrace_profiler(void) |
898 | { | |
899 | return register_ftrace_function(&ftrace_profile_ops); | |
900 | } | |
901 | ||
902 | static void unregister_ftrace_profiler(void) | |
903 | { | |
904 | unregister_ftrace_function(&ftrace_profile_ops); | |
905 | } | |
906 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
907 | ||
bac429f0 SR |
908 | static ssize_t |
909 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
910 | size_t cnt, loff_t *ppos) | |
911 | { | |
912 | unsigned long val; | |
bac429f0 SR |
913 | int ret; |
914 | ||
22fe9b54 PH |
915 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
916 | if (ret) | |
bac429f0 SR |
917 | return ret; |
918 | ||
919 | val = !!val; | |
920 | ||
921 | mutex_lock(&ftrace_profile_lock); | |
922 | if (ftrace_profile_enabled ^ val) { | |
923 | if (val) { | |
493762fc SR |
924 | ret = ftrace_profile_init(); |
925 | if (ret < 0) { | |
926 | cnt = ret; | |
927 | goto out; | |
928 | } | |
929 | ||
0706f1c4 SR |
930 | ret = register_ftrace_profiler(); |
931 | if (ret < 0) { | |
932 | cnt = ret; | |
933 | goto out; | |
934 | } | |
bac429f0 SR |
935 | ftrace_profile_enabled = 1; |
936 | } else { | |
937 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
938 | /* |
939 | * unregister_ftrace_profiler calls stop_machine | |
74401729 | 940 | * so this acts like an synchronize_rcu. |
0f6ce3de | 941 | */ |
0706f1c4 | 942 | unregister_ftrace_profiler(); |
bac429f0 SR |
943 | } |
944 | } | |
493762fc | 945 | out: |
bac429f0 SR |
946 | mutex_unlock(&ftrace_profile_lock); |
947 | ||
cf8517cf | 948 | *ppos += cnt; |
bac429f0 SR |
949 | |
950 | return cnt; | |
951 | } | |
952 | ||
493762fc SR |
953 | static ssize_t |
954 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
955 | size_t cnt, loff_t *ppos) | |
956 | { | |
fb9fb015 | 957 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
958 | int r; |
959 | ||
960 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
961 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
962 | } | |
963 | ||
bac429f0 SR |
964 | static const struct file_operations ftrace_profile_fops = { |
965 | .open = tracing_open_generic, | |
966 | .read = ftrace_profile_read, | |
967 | .write = ftrace_profile_write, | |
6038f373 | 968 | .llseek = default_llseek, |
bac429f0 SR |
969 | }; |
970 | ||
cafb168a SR |
971 | /* used to initialize the real stat files */ |
972 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
973 | .name = "functions", |
974 | .stat_start = function_stat_start, | |
975 | .stat_next = function_stat_next, | |
976 | .stat_cmp = function_stat_cmp, | |
977 | .stat_headers = function_stat_headers, | |
978 | .stat_show = function_stat_show | |
cafb168a SR |
979 | }; |
980 | ||
8434dc93 | 981 | static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
bac429f0 | 982 | { |
cafb168a | 983 | struct ftrace_profile_stat *stat; |
cafb168a | 984 | char *name; |
bac429f0 | 985 | int ret; |
cafb168a SR |
986 | int cpu; |
987 | ||
988 | for_each_possible_cpu(cpu) { | |
989 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
990 | ||
6363c6b5 | 991 | name = kasprintf(GFP_KERNEL, "function%d", cpu); |
cafb168a SR |
992 | if (!name) { |
993 | /* | |
994 | * The files created are permanent, if something happens | |
995 | * we still do not free memory. | |
996 | */ | |
cafb168a SR |
997 | WARN(1, |
998 | "Could not allocate stat file for cpu %d\n", | |
999 | cpu); | |
1000 | return; | |
1001 | } | |
1002 | stat->stat = function_stats; | |
cafb168a SR |
1003 | stat->stat.name = name; |
1004 | ret = register_stat_tracer(&stat->stat); | |
1005 | if (ret) { | |
1006 | WARN(1, | |
1007 | "Could not register function stat for cpu %d\n", | |
1008 | cpu); | |
1009 | kfree(name); | |
1010 | return; | |
1011 | } | |
bac429f0 SR |
1012 | } |
1013 | ||
e4931b82 YW |
1014 | trace_create_file("function_profile_enabled", |
1015 | TRACE_MODE_WRITE, d_tracer, NULL, | |
1016 | &ftrace_profile_fops); | |
bac429f0 SR |
1017 | } |
1018 | ||
bac429f0 | 1019 | #else /* CONFIG_FUNCTION_PROFILER */ |
8434dc93 | 1020 | static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
bac429f0 SR |
1021 | { |
1022 | } | |
bac429f0 SR |
1023 | #endif /* CONFIG_FUNCTION_PROFILER */ |
1024 | ||
493762fc SR |
1025 | #ifdef CONFIG_DYNAMIC_FTRACE |
1026 | ||
79922b80 SRRH |
1027 | static struct ftrace_ops *removed_ops; |
1028 | ||
e1effa01 SRRH |
1029 | /* |
1030 | * Set when doing a global update, like enabling all recs or disabling them. | |
1031 | * It is not set when just updating a single ftrace_ops. | |
1032 | */ | |
1033 | static bool update_all_ops; | |
1034 | ||
493762fc SR |
1035 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
1036 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
1037 | #endif | |
1038 | ||
7b60f3d8 SRV |
1039 | struct ftrace_func_probe { |
1040 | struct ftrace_probe_ops *probe_ops; | |
1041 | struct ftrace_ops ops; | |
1042 | struct trace_array *tr; | |
1043 | struct list_head list; | |
6e444319 | 1044 | void *data; |
7b60f3d8 SRV |
1045 | int ref; |
1046 | }; | |
1047 | ||
33dc9b12 SR |
1048 | /* |
1049 | * We make these constant because no one should touch them, | |
1050 | * but they are used as the default "empty hash", to avoid allocating | |
1051 | * it all the time. These are in a read only section such that if | |
1052 | * anyone does try to modify it, it will cause an exception. | |
1053 | */ | |
1054 | static const struct hlist_head empty_buckets[1]; | |
1055 | static const struct ftrace_hash empty_hash = { | |
1056 | .buckets = (struct hlist_head *)empty_buckets, | |
1cf41dd7 | 1057 | }; |
33dc9b12 | 1058 | #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash) |
493762fc | 1059 | |
3306fc4a | 1060 | struct ftrace_ops global_ops = { |
33b7f99c SRRH |
1061 | .func = ftrace_stub, |
1062 | .local_hash.notrace_hash = EMPTY_HASH, | |
1063 | .local_hash.filter_hash = EMPTY_HASH, | |
1064 | INIT_OPS_HASH(global_ops) | |
a25d036d | 1065 | .flags = FTRACE_OPS_FL_INITIALIZED | |
e3eea140 | 1066 | FTRACE_OPS_FL_PID, |
f45948e8 SR |
1067 | }; |
1068 | ||
aec0be2d | 1069 | /* |
f2cc020d | 1070 | * Used by the stack unwinder to know about dynamic ftrace trampolines. |
aec0be2d | 1071 | */ |
6be7fa3c | 1072 | struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr) |
aec0be2d | 1073 | { |
6be7fa3c | 1074 | struct ftrace_ops *op = NULL; |
aec0be2d SRRH |
1075 | |
1076 | /* | |
1077 | * Some of the ops may be dynamically allocated, | |
74401729 | 1078 | * they are freed after a synchronize_rcu(). |
aec0be2d SRRH |
1079 | */ |
1080 | preempt_disable_notrace(); | |
1081 | ||
1082 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1083 | /* | |
1084 | * This is to check for dynamically allocated trampolines. | |
1085 | * Trampolines that are in kernel text will have | |
1086 | * core_kernel_text() return true. | |
1087 | */ | |
1088 | if (op->trampoline && op->trampoline_size) | |
1089 | if (addr >= op->trampoline && | |
1090 | addr < op->trampoline + op->trampoline_size) { | |
6be7fa3c SRV |
1091 | preempt_enable_notrace(); |
1092 | return op; | |
aec0be2d SRRH |
1093 | } |
1094 | } while_for_each_ftrace_op(op); | |
aec0be2d SRRH |
1095 | preempt_enable_notrace(); |
1096 | ||
6be7fa3c SRV |
1097 | return NULL; |
1098 | } | |
1099 | ||
1100 | /* | |
1101 | * This is used by __kernel_text_address() to return true if the | |
1102 | * address is on a dynamically allocated trampoline that would | |
1103 | * not return true for either core_kernel_text() or | |
1104 | * is_module_text_address(). | |
1105 | */ | |
1106 | bool is_ftrace_trampoline(unsigned long addr) | |
1107 | { | |
1108 | return ftrace_ops_trampoline(addr) != NULL; | |
aec0be2d SRRH |
1109 | } |
1110 | ||
493762fc SR |
1111 | struct ftrace_page { |
1112 | struct ftrace_page *next; | |
a7900875 | 1113 | struct dyn_ftrace *records; |
493762fc | 1114 | int index; |
db42523b | 1115 | int order; |
493762fc SR |
1116 | }; |
1117 | ||
a7900875 SR |
1118 | #define ENTRY_SIZE sizeof(struct dyn_ftrace) |
1119 | #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE) | |
493762fc | 1120 | |
493762fc SR |
1121 | static struct ftrace_page *ftrace_pages_start; |
1122 | static struct ftrace_page *ftrace_pages; | |
1123 | ||
2b0cce0e SRV |
1124 | static __always_inline unsigned long |
1125 | ftrace_hash_key(struct ftrace_hash *hash, unsigned long ip) | |
1126 | { | |
1127 | if (hash->size_bits > 0) | |
1128 | return hash_long(ip, hash->size_bits); | |
1129 | ||
1130 | return 0; | |
1131 | } | |
1132 | ||
2b2c279c SRV |
1133 | /* Only use this function if ftrace_hash_empty() has already been tested */ |
1134 | static __always_inline struct ftrace_func_entry * | |
1135 | __ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
b448c4e3 SR |
1136 | { |
1137 | unsigned long key; | |
1138 | struct ftrace_func_entry *entry; | |
1139 | struct hlist_head *hhd; | |
b448c4e3 | 1140 | |
2b0cce0e | 1141 | key = ftrace_hash_key(hash, ip); |
b448c4e3 SR |
1142 | hhd = &hash->buckets[key]; |
1143 | ||
1bb539ca | 1144 | hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) { |
b448c4e3 SR |
1145 | if (entry->ip == ip) |
1146 | return entry; | |
1147 | } | |
1148 | return NULL; | |
1149 | } | |
1150 | ||
2b2c279c SRV |
1151 | /** |
1152 | * ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash | |
1153 | * @hash: The hash to look at | |
1154 | * @ip: The instruction pointer to test | |
1155 | * | |
1156 | * Search a given @hash to see if a given instruction pointer (@ip) | |
1157 | * exists in it. | |
1158 | * | |
1159 | * Returns the entry that holds the @ip if found. NULL otherwise. | |
1160 | */ | |
1161 | struct ftrace_func_entry * | |
1162 | ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
1163 | { | |
1164 | if (ftrace_hash_empty(hash)) | |
1165 | return NULL; | |
1166 | ||
1167 | return __ftrace_lookup_ip(hash, ip); | |
1168 | } | |
1169 | ||
33dc9b12 SR |
1170 | static void __add_hash_entry(struct ftrace_hash *hash, |
1171 | struct ftrace_func_entry *entry) | |
b448c4e3 | 1172 | { |
b448c4e3 SR |
1173 | struct hlist_head *hhd; |
1174 | unsigned long key; | |
1175 | ||
2b0cce0e | 1176 | key = ftrace_hash_key(hash, entry->ip); |
b448c4e3 SR |
1177 | hhd = &hash->buckets[key]; |
1178 | hlist_add_head(&entry->hlist, hhd); | |
1179 | hash->count++; | |
33dc9b12 SR |
1180 | } |
1181 | ||
1182 | static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip) | |
1183 | { | |
1184 | struct ftrace_func_entry *entry; | |
1185 | ||
1186 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1187 | if (!entry) | |
1188 | return -ENOMEM; | |
1189 | ||
1190 | entry->ip = ip; | |
1191 | __add_hash_entry(hash, entry); | |
b448c4e3 SR |
1192 | |
1193 | return 0; | |
1194 | } | |
1195 | ||
1196 | static void | |
33dc9b12 | 1197 | free_hash_entry(struct ftrace_hash *hash, |
b448c4e3 SR |
1198 | struct ftrace_func_entry *entry) |
1199 | { | |
1200 | hlist_del(&entry->hlist); | |
1201 | kfree(entry); | |
1202 | hash->count--; | |
1203 | } | |
1204 | ||
33dc9b12 SR |
1205 | static void |
1206 | remove_hash_entry(struct ftrace_hash *hash, | |
1207 | struct ftrace_func_entry *entry) | |
1208 | { | |
eee8ded1 | 1209 | hlist_del_rcu(&entry->hlist); |
33dc9b12 SR |
1210 | hash->count--; |
1211 | } | |
1212 | ||
b448c4e3 SR |
1213 | static void ftrace_hash_clear(struct ftrace_hash *hash) |
1214 | { | |
1215 | struct hlist_head *hhd; | |
b67bfe0d | 1216 | struct hlist_node *tn; |
b448c4e3 SR |
1217 | struct ftrace_func_entry *entry; |
1218 | int size = 1 << hash->size_bits; | |
1219 | int i; | |
1220 | ||
33dc9b12 SR |
1221 | if (!hash->count) |
1222 | return; | |
1223 | ||
b448c4e3 SR |
1224 | for (i = 0; i < size; i++) { |
1225 | hhd = &hash->buckets[i]; | |
b67bfe0d | 1226 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) |
33dc9b12 | 1227 | free_hash_entry(hash, entry); |
b448c4e3 SR |
1228 | } |
1229 | FTRACE_WARN_ON(hash->count); | |
1230 | } | |
1231 | ||
673feb9d SRV |
1232 | static void free_ftrace_mod(struct ftrace_mod_load *ftrace_mod) |
1233 | { | |
1234 | list_del(&ftrace_mod->list); | |
1235 | kfree(ftrace_mod->module); | |
1236 | kfree(ftrace_mod->func); | |
1237 | kfree(ftrace_mod); | |
1238 | } | |
1239 | ||
1240 | static void clear_ftrace_mod_list(struct list_head *head) | |
1241 | { | |
1242 | struct ftrace_mod_load *p, *n; | |
1243 | ||
1244 | /* stack tracer isn't supported yet */ | |
1245 | if (!head) | |
1246 | return; | |
1247 | ||
1248 | mutex_lock(&ftrace_lock); | |
1249 | list_for_each_entry_safe(p, n, head, list) | |
1250 | free_ftrace_mod(p); | |
1251 | mutex_unlock(&ftrace_lock); | |
1252 | } | |
1253 | ||
33dc9b12 SR |
1254 | static void free_ftrace_hash(struct ftrace_hash *hash) |
1255 | { | |
1256 | if (!hash || hash == EMPTY_HASH) | |
1257 | return; | |
1258 | ftrace_hash_clear(hash); | |
1259 | kfree(hash->buckets); | |
1260 | kfree(hash); | |
1261 | } | |
1262 | ||
07fd5515 SR |
1263 | static void __free_ftrace_hash_rcu(struct rcu_head *rcu) |
1264 | { | |
1265 | struct ftrace_hash *hash; | |
1266 | ||
1267 | hash = container_of(rcu, struct ftrace_hash, rcu); | |
1268 | free_ftrace_hash(hash); | |
1269 | } | |
1270 | ||
1271 | static void free_ftrace_hash_rcu(struct ftrace_hash *hash) | |
1272 | { | |
1273 | if (!hash || hash == EMPTY_HASH) | |
1274 | return; | |
74401729 | 1275 | call_rcu(&hash->rcu, __free_ftrace_hash_rcu); |
07fd5515 SR |
1276 | } |
1277 | ||
8be9fbd5 MR |
1278 | /** |
1279 | * ftrace_free_filter - remove all filters for an ftrace_ops | |
1280 | * @ops - the ops to remove the filters from | |
1281 | */ | |
5500fa51 JO |
1282 | void ftrace_free_filter(struct ftrace_ops *ops) |
1283 | { | |
f04f24fb | 1284 | ftrace_ops_init(ops); |
33b7f99c SRRH |
1285 | free_ftrace_hash(ops->func_hash->filter_hash); |
1286 | free_ftrace_hash(ops->func_hash->notrace_hash); | |
5500fa51 | 1287 | } |
8be9fbd5 | 1288 | EXPORT_SYMBOL_GPL(ftrace_free_filter); |
5500fa51 | 1289 | |
33dc9b12 SR |
1290 | static struct ftrace_hash *alloc_ftrace_hash(int size_bits) |
1291 | { | |
1292 | struct ftrace_hash *hash; | |
1293 | int size; | |
1294 | ||
1295 | hash = kzalloc(sizeof(*hash), GFP_KERNEL); | |
1296 | if (!hash) | |
1297 | return NULL; | |
1298 | ||
1299 | size = 1 << size_bits; | |
47b0edcb | 1300 | hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL); |
33dc9b12 SR |
1301 | |
1302 | if (!hash->buckets) { | |
1303 | kfree(hash); | |
1304 | return NULL; | |
1305 | } | |
1306 | ||
1307 | hash->size_bits = size_bits; | |
1308 | ||
1309 | return hash; | |
1310 | } | |
1311 | ||
673feb9d SRV |
1312 | |
1313 | static int ftrace_add_mod(struct trace_array *tr, | |
1314 | const char *func, const char *module, | |
1315 | int enable) | |
1316 | { | |
1317 | struct ftrace_mod_load *ftrace_mod; | |
1318 | struct list_head *mod_head = enable ? &tr->mod_trace : &tr->mod_notrace; | |
1319 | ||
1320 | ftrace_mod = kzalloc(sizeof(*ftrace_mod), GFP_KERNEL); | |
1321 | if (!ftrace_mod) | |
1322 | return -ENOMEM; | |
1323 | ||
19ba6c8a | 1324 | INIT_LIST_HEAD(&ftrace_mod->list); |
673feb9d SRV |
1325 | ftrace_mod->func = kstrdup(func, GFP_KERNEL); |
1326 | ftrace_mod->module = kstrdup(module, GFP_KERNEL); | |
1327 | ftrace_mod->enable = enable; | |
1328 | ||
1329 | if (!ftrace_mod->func || !ftrace_mod->module) | |
1330 | goto out_free; | |
1331 | ||
1332 | list_add(&ftrace_mod->list, mod_head); | |
1333 | ||
1334 | return 0; | |
1335 | ||
1336 | out_free: | |
1337 | free_ftrace_mod(ftrace_mod); | |
1338 | ||
1339 | return -ENOMEM; | |
1340 | } | |
1341 | ||
33dc9b12 SR |
1342 | static struct ftrace_hash * |
1343 | alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) | |
1344 | { | |
1345 | struct ftrace_func_entry *entry; | |
1346 | struct ftrace_hash *new_hash; | |
33dc9b12 SR |
1347 | int size; |
1348 | int ret; | |
1349 | int i; | |
1350 | ||
1351 | new_hash = alloc_ftrace_hash(size_bits); | |
1352 | if (!new_hash) | |
1353 | return NULL; | |
1354 | ||
8c08f0d5 SRV |
1355 | if (hash) |
1356 | new_hash->flags = hash->flags; | |
1357 | ||
33dc9b12 | 1358 | /* Empty hash? */ |
06a51d93 | 1359 | if (ftrace_hash_empty(hash)) |
33dc9b12 SR |
1360 | return new_hash; |
1361 | ||
1362 | size = 1 << hash->size_bits; | |
1363 | for (i = 0; i < size; i++) { | |
b67bfe0d | 1364 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { |
33dc9b12 SR |
1365 | ret = add_hash_entry(new_hash, entry->ip); |
1366 | if (ret < 0) | |
1367 | goto free_hash; | |
1368 | } | |
1369 | } | |
1370 | ||
1371 | FTRACE_WARN_ON(new_hash->count != hash->count); | |
1372 | ||
1373 | return new_hash; | |
1374 | ||
1375 | free_hash: | |
1376 | free_ftrace_hash(new_hash); | |
1377 | return NULL; | |
1378 | } | |
1379 | ||
41fb61c2 | 1380 | static void |
84261912 | 1381 | ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash); |
41fb61c2 | 1382 | static void |
84261912 | 1383 | ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash); |
41fb61c2 | 1384 | |
f8b8be8a MH |
1385 | static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, |
1386 | struct ftrace_hash *new_hash); | |
1387 | ||
714641c3 | 1388 | static struct ftrace_hash *dup_hash(struct ftrace_hash *src, int size) |
33dc9b12 SR |
1389 | { |
1390 | struct ftrace_func_entry *entry; | |
07fd5515 | 1391 | struct ftrace_hash *new_hash; |
714641c3 SRV |
1392 | struct hlist_head *hhd; |
1393 | struct hlist_node *tn; | |
33dc9b12 SR |
1394 | int bits = 0; |
1395 | int i; | |
1396 | ||
33dc9b12 | 1397 | /* |
be493132 SRV |
1398 | * Use around half the size (max bit of it), but |
1399 | * a minimum of 2 is fine (as size of 0 or 1 both give 1 for bits). | |
33dc9b12 | 1400 | */ |
be493132 | 1401 | bits = fls(size / 2); |
33dc9b12 SR |
1402 | |
1403 | /* Don't allocate too much */ | |
1404 | if (bits > FTRACE_HASH_MAX_BITS) | |
1405 | bits = FTRACE_HASH_MAX_BITS; | |
1406 | ||
07fd5515 SR |
1407 | new_hash = alloc_ftrace_hash(bits); |
1408 | if (!new_hash) | |
3e278c0d | 1409 | return NULL; |
33dc9b12 | 1410 | |
8c08f0d5 SRV |
1411 | new_hash->flags = src->flags; |
1412 | ||
33dc9b12 SR |
1413 | size = 1 << src->size_bits; |
1414 | for (i = 0; i < size; i++) { | |
1415 | hhd = &src->buckets[i]; | |
b67bfe0d | 1416 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) { |
33dc9b12 | 1417 | remove_hash_entry(src, entry); |
07fd5515 | 1418 | __add_hash_entry(new_hash, entry); |
33dc9b12 SR |
1419 | } |
1420 | } | |
3e278c0d NK |
1421 | return new_hash; |
1422 | } | |
1423 | ||
714641c3 SRV |
1424 | static struct ftrace_hash * |
1425 | __ftrace_hash_move(struct ftrace_hash *src) | |
1426 | { | |
1427 | int size = src->count; | |
1428 | ||
1429 | /* | |
1430 | * If the new source is empty, just return the empty_hash. | |
1431 | */ | |
1432 | if (ftrace_hash_empty(src)) | |
1433 | return EMPTY_HASH; | |
1434 | ||
1435 | return dup_hash(src, size); | |
1436 | } | |
1437 | ||
3e278c0d NK |
1438 | static int |
1439 | ftrace_hash_move(struct ftrace_ops *ops, int enable, | |
1440 | struct ftrace_hash **dst, struct ftrace_hash *src) | |
1441 | { | |
1442 | struct ftrace_hash *new_hash; | |
1443 | int ret; | |
1444 | ||
1445 | /* Reject setting notrace hash on IPMODIFY ftrace_ops */ | |
1446 | if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable) | |
1447 | return -EINVAL; | |
1448 | ||
1449 | new_hash = __ftrace_hash_move(src); | |
1450 | if (!new_hash) | |
1451 | return -ENOMEM; | |
1452 | ||
f8b8be8a MH |
1453 | /* Make sure this can be applied if it is IPMODIFY ftrace_ops */ |
1454 | if (enable) { | |
1455 | /* IPMODIFY should be updated only when filter_hash updating */ | |
1456 | ret = ftrace_hash_ipmodify_update(ops, new_hash); | |
1457 | if (ret < 0) { | |
1458 | free_ftrace_hash(new_hash); | |
1459 | return ret; | |
1460 | } | |
1461 | } | |
1462 | ||
5c27c775 MH |
1463 | /* |
1464 | * Remove the current set, update the hash and add | |
1465 | * them back. | |
1466 | */ | |
84261912 | 1467 | ftrace_hash_rec_disable_modify(ops, enable); |
5c27c775 | 1468 | |
07fd5515 | 1469 | rcu_assign_pointer(*dst, new_hash); |
07fd5515 | 1470 | |
84261912 | 1471 | ftrace_hash_rec_enable_modify(ops, enable); |
41fb61c2 | 1472 | |
5c27c775 | 1473 | return 0; |
33dc9b12 SR |
1474 | } |
1475 | ||
fef5aeee SRRH |
1476 | static bool hash_contains_ip(unsigned long ip, |
1477 | struct ftrace_ops_hash *hash) | |
1478 | { | |
1479 | /* | |
1480 | * The function record is a match if it exists in the filter | |
fdda88d3 | 1481 | * hash and not in the notrace hash. Note, an empty hash is |
fef5aeee SRRH |
1482 | * considered a match for the filter hash, but an empty |
1483 | * notrace hash is considered not in the notrace hash. | |
1484 | */ | |
1485 | return (ftrace_hash_empty(hash->filter_hash) || | |
2b2c279c | 1486 | __ftrace_lookup_ip(hash->filter_hash, ip)) && |
fef5aeee | 1487 | (ftrace_hash_empty(hash->notrace_hash) || |
2b2c279c | 1488 | !__ftrace_lookup_ip(hash->notrace_hash, ip)); |
fef5aeee SRRH |
1489 | } |
1490 | ||
b848914c SR |
1491 | /* |
1492 | * Test the hashes for this ops to see if we want to call | |
1493 | * the ops->func or not. | |
1494 | * | |
1495 | * It's a match if the ip is in the ops->filter_hash or | |
1496 | * the filter_hash does not exist or is empty, | |
1497 | * AND | |
1498 | * the ip is not in the ops->notrace_hash. | |
cdbe61bf SR |
1499 | * |
1500 | * This needs to be called with preemption disabled as | |
74401729 | 1501 | * the hashes are freed with call_rcu(). |
b848914c | 1502 | */ |
3306fc4a | 1503 | int |
195a8afc | 1504 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
b848914c | 1505 | { |
fef5aeee | 1506 | struct ftrace_ops_hash hash; |
b848914c SR |
1507 | int ret; |
1508 | ||
195a8afc SRRH |
1509 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
1510 | /* | |
1511 | * There's a small race when adding ops that the ftrace handler | |
1512 | * that wants regs, may be called without them. We can not | |
1513 | * allow that handler to be called if regs is NULL. | |
1514 | */ | |
1515 | if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS)) | |
1516 | return 0; | |
1517 | #endif | |
1518 | ||
f86f4180 CZ |
1519 | rcu_assign_pointer(hash.filter_hash, ops->func_hash->filter_hash); |
1520 | rcu_assign_pointer(hash.notrace_hash, ops->func_hash->notrace_hash); | |
b848914c | 1521 | |
fef5aeee | 1522 | if (hash_contains_ip(ip, &hash)) |
b848914c SR |
1523 | ret = 1; |
1524 | else | |
1525 | ret = 0; | |
b848914c SR |
1526 | |
1527 | return ret; | |
1528 | } | |
1529 | ||
493762fc SR |
1530 | /* |
1531 | * This is a double for. Do not use 'break' to break out of the loop, | |
1532 | * you must use a goto. | |
1533 | */ | |
1534 | #define do_for_each_ftrace_rec(pg, rec) \ | |
1535 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
1536 | int _____i; \ | |
1537 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
1538 | rec = &pg->records[_____i]; | |
1539 | ||
1540 | #define while_for_each_ftrace_rec() \ | |
1541 | } \ | |
1542 | } | |
1543 | ||
5855fead SR |
1544 | |
1545 | static int ftrace_cmp_recs(const void *a, const void *b) | |
1546 | { | |
a650e02a SR |
1547 | const struct dyn_ftrace *key = a; |
1548 | const struct dyn_ftrace *rec = b; | |
5855fead | 1549 | |
a650e02a | 1550 | if (key->flags < rec->ip) |
5855fead | 1551 | return -1; |
a650e02a SR |
1552 | if (key->ip >= rec->ip + MCOUNT_INSN_SIZE) |
1553 | return 1; | |
5855fead SR |
1554 | return 0; |
1555 | } | |
1556 | ||
7e16f581 SRV |
1557 | static struct dyn_ftrace *lookup_rec(unsigned long start, unsigned long end) |
1558 | { | |
1559 | struct ftrace_page *pg; | |
1560 | struct dyn_ftrace *rec = NULL; | |
1561 | struct dyn_ftrace key; | |
1562 | ||
1563 | key.ip = start; | |
1564 | key.flags = end; /* overload flags, as it is unsigned long */ | |
1565 | ||
1566 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
ee92fa44 CZ |
1567 | if (pg->index == 0 || |
1568 | end < pg->records[0].ip || | |
7e16f581 SRV |
1569 | start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) |
1570 | continue; | |
1571 | rec = bsearch(&key, pg->records, pg->index, | |
1572 | sizeof(struct dyn_ftrace), | |
1573 | ftrace_cmp_recs); | |
d9815bff AS |
1574 | if (rec) |
1575 | break; | |
7e16f581 SRV |
1576 | } |
1577 | return rec; | |
1578 | } | |
1579 | ||
04cf31a7 ME |
1580 | /** |
1581 | * ftrace_location_range - return the first address of a traced location | |
1582 | * if it touches the given ip range | |
1583 | * @start: start of range to search. | |
1584 | * @end: end of range to search (inclusive). @end points to the last byte | |
1585 | * to check. | |
1586 | * | |
1587 | * Returns rec->ip if the related ftrace location is a least partly within | |
1588 | * the given address range. That is, the first address of the instruction | |
1589 | * that is either a NOP or call to the function tracer. It checks the ftrace | |
1590 | * internal tables to determine if the address belongs or not. | |
1591 | */ | |
1592 | unsigned long ftrace_location_range(unsigned long start, unsigned long end) | |
c88fd863 | 1593 | { |
c88fd863 | 1594 | struct dyn_ftrace *rec; |
5855fead | 1595 | |
7e16f581 SRV |
1596 | rec = lookup_rec(start, end); |
1597 | if (rec) | |
1598 | return rec->ip; | |
c88fd863 SR |
1599 | |
1600 | return 0; | |
1601 | } | |
1602 | ||
a650e02a | 1603 | /** |
aebfd125 | 1604 | * ftrace_location - return the ftrace location |
a650e02a SR |
1605 | * @ip: the instruction pointer to check |
1606 | * | |
aebfd125 PZ |
1607 | * If @ip matches the ftrace location, return @ip. |
1608 | * If @ip matches sym+0, return sym's ftrace location. | |
1609 | * Otherwise, return 0. | |
a650e02a | 1610 | */ |
f0cf973a | 1611 | unsigned long ftrace_location(unsigned long ip) |
a650e02a | 1612 | { |
aebfd125 PZ |
1613 | struct dyn_ftrace *rec; |
1614 | unsigned long offset; | |
1615 | unsigned long size; | |
1616 | ||
1617 | rec = lookup_rec(ip, ip); | |
1618 | if (!rec) { | |
1619 | if (!kallsyms_lookup_size_offset(ip, &size, &offset)) | |
1620 | goto out; | |
1621 | ||
1622 | /* map sym+0 to __fentry__ */ | |
1623 | if (!offset) | |
1624 | rec = lookup_rec(ip, ip + size - 1); | |
1625 | } | |
1626 | ||
1627 | if (rec) | |
1628 | return rec->ip; | |
1629 | ||
1630 | out: | |
1631 | return 0; | |
a650e02a SR |
1632 | } |
1633 | ||
1634 | /** | |
1635 | * ftrace_text_reserved - return true if range contains an ftrace location | |
1636 | * @start: start of range to search | |
1637 | * @end: end of range to search (inclusive). @end points to the last byte to check. | |
1638 | * | |
1639 | * Returns 1 if @start and @end contains a ftrace location. | |
1640 | * That is, the instruction that is either a NOP or call to | |
1641 | * the function tracer. It checks the ftrace internal tables to | |
1642 | * determine if the address belongs or not. | |
1643 | */ | |
d88471cb | 1644 | int ftrace_text_reserved(const void *start, const void *end) |
a650e02a | 1645 | { |
f0cf973a SR |
1646 | unsigned long ret; |
1647 | ||
1648 | ret = ftrace_location_range((unsigned long)start, | |
1649 | (unsigned long)end); | |
1650 | ||
1651 | return (int)!!ret; | |
a650e02a SR |
1652 | } |
1653 | ||
4fbb48cb SRRH |
1654 | /* Test if ops registered to this rec needs regs */ |
1655 | static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec) | |
1656 | { | |
1657 | struct ftrace_ops *ops; | |
1658 | bool keep_regs = false; | |
1659 | ||
1660 | for (ops = ftrace_ops_list; | |
1661 | ops != &ftrace_list_end; ops = ops->next) { | |
1662 | /* pass rec in as regs to have non-NULL val */ | |
1663 | if (ftrace_ops_test(ops, rec->ip, rec)) { | |
1664 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1665 | keep_regs = true; | |
1666 | break; | |
1667 | } | |
1668 | } | |
1669 | } | |
1670 | ||
1671 | return keep_regs; | |
1672 | } | |
1673 | ||
a124692b CJ |
1674 | static struct ftrace_ops * |
1675 | ftrace_find_tramp_ops_any(struct dyn_ftrace *rec); | |
1676 | static struct ftrace_ops * | |
4c75b0ff NR |
1677 | ftrace_find_tramp_ops_any_other(struct dyn_ftrace *rec, struct ftrace_ops *op_exclude); |
1678 | static struct ftrace_ops * | |
a124692b CJ |
1679 | ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops); |
1680 | ||
cf04f2d5 SRG |
1681 | static bool skip_record(struct dyn_ftrace *rec) |
1682 | { | |
1683 | /* | |
1684 | * At boot up, weak functions are set to disable. Function tracing | |
1685 | * can be enabled before they are, and they still need to be disabled now. | |
1686 | * If the record is disabled, still continue if it is marked as already | |
1687 | * enabled (this is needed to keep the accounting working). | |
1688 | */ | |
1689 | return rec->flags & FTRACE_FL_DISABLED && | |
1690 | !(rec->flags & FTRACE_FL_ENABLED); | |
1691 | } | |
1692 | ||
84b6d3e6 | 1693 | static bool __ftrace_hash_rec_update(struct ftrace_ops *ops, |
ed926f9b SR |
1694 | int filter_hash, |
1695 | bool inc) | |
1696 | { | |
1697 | struct ftrace_hash *hash; | |
1698 | struct ftrace_hash *other_hash; | |
1699 | struct ftrace_page *pg; | |
1700 | struct dyn_ftrace *rec; | |
84b6d3e6 | 1701 | bool update = false; |
ed926f9b | 1702 | int count = 0; |
8c08f0d5 | 1703 | int all = false; |
ed926f9b SR |
1704 | |
1705 | /* Only update if the ops has been registered */ | |
1706 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
84b6d3e6 | 1707 | return false; |
ed926f9b SR |
1708 | |
1709 | /* | |
1710 | * In the filter_hash case: | |
1711 | * If the count is zero, we update all records. | |
1712 | * Otherwise we just update the items in the hash. | |
1713 | * | |
1714 | * In the notrace_hash case: | |
1715 | * We enable the update in the hash. | |
1716 | * As disabling notrace means enabling the tracing, | |
1717 | * and enabling notrace means disabling, the inc variable | |
1718 | * gets inversed. | |
1719 | */ | |
1720 | if (filter_hash) { | |
33b7f99c SRRH |
1721 | hash = ops->func_hash->filter_hash; |
1722 | other_hash = ops->func_hash->notrace_hash; | |
06a51d93 | 1723 | if (ftrace_hash_empty(hash)) |
8c08f0d5 | 1724 | all = true; |
ed926f9b SR |
1725 | } else { |
1726 | inc = !inc; | |
33b7f99c SRRH |
1727 | hash = ops->func_hash->notrace_hash; |
1728 | other_hash = ops->func_hash->filter_hash; | |
ed926f9b SR |
1729 | /* |
1730 | * If the notrace hash has no items, | |
1731 | * then there's nothing to do. | |
1732 | */ | |
06a51d93 | 1733 | if (ftrace_hash_empty(hash)) |
84b6d3e6 | 1734 | return false; |
ed926f9b SR |
1735 | } |
1736 | ||
1737 | do_for_each_ftrace_rec(pg, rec) { | |
1738 | int in_other_hash = 0; | |
1739 | int in_hash = 0; | |
1740 | int match = 0; | |
1741 | ||
cf04f2d5 | 1742 | if (skip_record(rec)) |
b7ffffbb SRRH |
1743 | continue; |
1744 | ||
ed926f9b SR |
1745 | if (all) { |
1746 | /* | |
1747 | * Only the filter_hash affects all records. | |
1748 | * Update if the record is not in the notrace hash. | |
1749 | */ | |
b848914c | 1750 | if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) |
ed926f9b SR |
1751 | match = 1; |
1752 | } else { | |
06a51d93 SR |
1753 | in_hash = !!ftrace_lookup_ip(hash, rec->ip); |
1754 | in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip); | |
ed926f9b SR |
1755 | |
1756 | /* | |
19eab4a4 SRRH |
1757 | * If filter_hash is set, we want to match all functions |
1758 | * that are in the hash but not in the other hash. | |
ed926f9b | 1759 | * |
19eab4a4 SRRH |
1760 | * If filter_hash is not set, then we are decrementing. |
1761 | * That means we match anything that is in the hash | |
1762 | * and also in the other_hash. That is, we need to turn | |
1763 | * off functions in the other hash because they are disabled | |
1764 | * by this hash. | |
ed926f9b SR |
1765 | */ |
1766 | if (filter_hash && in_hash && !in_other_hash) | |
1767 | match = 1; | |
1768 | else if (!filter_hash && in_hash && | |
06a51d93 | 1769 | (in_other_hash || ftrace_hash_empty(other_hash))) |
ed926f9b SR |
1770 | match = 1; |
1771 | } | |
1772 | if (!match) | |
1773 | continue; | |
1774 | ||
1775 | if (inc) { | |
1776 | rec->flags++; | |
0376bde1 | 1777 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX)) |
84b6d3e6 | 1778 | return false; |
79922b80 | 1779 | |
763e34e7 SRV |
1780 | if (ops->flags & FTRACE_OPS_FL_DIRECT) |
1781 | rec->flags |= FTRACE_FL_DIRECT; | |
1782 | ||
79922b80 SRRH |
1783 | /* |
1784 | * If there's only a single callback registered to a | |
1785 | * function, and the ops has a trampoline registered | |
1786 | * for it, then we can call it directly. | |
1787 | */ | |
fef5aeee | 1788 | if (ftrace_rec_count(rec) == 1 && ops->trampoline) |
79922b80 | 1789 | rec->flags |= FTRACE_FL_TRAMP; |
fef5aeee | 1790 | else |
79922b80 SRRH |
1791 | /* |
1792 | * If we are adding another function callback | |
1793 | * to this function, and the previous had a | |
bce0b6c5 SRRH |
1794 | * custom trampoline in use, then we need to go |
1795 | * back to the default trampoline. | |
79922b80 | 1796 | */ |
fef5aeee | 1797 | rec->flags &= ~FTRACE_FL_TRAMP; |
79922b80 | 1798 | |
08f6fba5 SR |
1799 | /* |
1800 | * If any ops wants regs saved for this function | |
1801 | * then all ops will get saved regs. | |
1802 | */ | |
1803 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) | |
1804 | rec->flags |= FTRACE_FL_REGS; | |
ed926f9b | 1805 | } else { |
0376bde1 | 1806 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0)) |
84b6d3e6 | 1807 | return false; |
ed926f9b | 1808 | rec->flags--; |
79922b80 | 1809 | |
763e34e7 SRV |
1810 | /* |
1811 | * Only the internal direct_ops should have the | |
1812 | * DIRECT flag set. Thus, if it is removing a | |
1813 | * function, then that function should no longer | |
1814 | * be direct. | |
1815 | */ | |
1816 | if (ops->flags & FTRACE_OPS_FL_DIRECT) | |
1817 | rec->flags &= ~FTRACE_FL_DIRECT; | |
1818 | ||
4fbb48cb SRRH |
1819 | /* |
1820 | * If the rec had REGS enabled and the ops that is | |
1821 | * being removed had REGS set, then see if there is | |
1822 | * still any ops for this record that wants regs. | |
1823 | * If not, we can stop recording them. | |
1824 | */ | |
0376bde1 | 1825 | if (ftrace_rec_count(rec) > 0 && |
4fbb48cb SRRH |
1826 | rec->flags & FTRACE_FL_REGS && |
1827 | ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1828 | if (!test_rec_ops_needs_regs(rec)) | |
1829 | rec->flags &= ~FTRACE_FL_REGS; | |
1830 | } | |
79922b80 | 1831 | |
fef5aeee | 1832 | /* |
a124692b CJ |
1833 | * The TRAMP needs to be set only if rec count |
1834 | * is decremented to one, and the ops that is | |
1835 | * left has a trampoline. As TRAMP can only be | |
1836 | * enabled if there is only a single ops attached | |
1837 | * to it. | |
fef5aeee | 1838 | */ |
a124692b | 1839 | if (ftrace_rec_count(rec) == 1 && |
4c75b0ff | 1840 | ftrace_find_tramp_ops_any_other(rec, ops)) |
a124692b CJ |
1841 | rec->flags |= FTRACE_FL_TRAMP; |
1842 | else | |
1843 | rec->flags &= ~FTRACE_FL_TRAMP; | |
fef5aeee | 1844 | |
79922b80 SRRH |
1845 | /* |
1846 | * flags will be cleared in ftrace_check_record() | |
1847 | * if rec count is zero. | |
1848 | */ | |
ed926f9b | 1849 | } |
cbad0fb2 MR |
1850 | |
1851 | /* | |
1852 | * If the rec has a single associated ops, and ops->func can be | |
1853 | * called directly, allow the call site to call via the ops. | |
1854 | */ | |
1855 | if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS) && | |
1856 | ftrace_rec_count(rec) == 1 && | |
1857 | ftrace_ops_get_func(ops) == ops->func) | |
1858 | rec->flags |= FTRACE_FL_CALL_OPS; | |
1859 | else | |
1860 | rec->flags &= ~FTRACE_FL_CALL_OPS; | |
1861 | ||
ed926f9b | 1862 | count++; |
84b6d3e6 JO |
1863 | |
1864 | /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */ | |
7375dca1 | 1865 | update |= ftrace_test_record(rec, true) != FTRACE_UPDATE_IGNORE; |
84b6d3e6 | 1866 | |
ed926f9b SR |
1867 | /* Shortcut, if we handled all records, we are done. */ |
1868 | if (!all && count == hash->count) | |
84b6d3e6 | 1869 | return update; |
ed926f9b | 1870 | } while_for_each_ftrace_rec(); |
84b6d3e6 JO |
1871 | |
1872 | return update; | |
ed926f9b SR |
1873 | } |
1874 | ||
84b6d3e6 | 1875 | static bool ftrace_hash_rec_disable(struct ftrace_ops *ops, |
ed926f9b SR |
1876 | int filter_hash) |
1877 | { | |
84b6d3e6 | 1878 | return __ftrace_hash_rec_update(ops, filter_hash, 0); |
ed926f9b SR |
1879 | } |
1880 | ||
84b6d3e6 | 1881 | static bool ftrace_hash_rec_enable(struct ftrace_ops *ops, |
ed926f9b SR |
1882 | int filter_hash) |
1883 | { | |
84b6d3e6 | 1884 | return __ftrace_hash_rec_update(ops, filter_hash, 1); |
ed926f9b SR |
1885 | } |
1886 | ||
84261912 SRRH |
1887 | static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops, |
1888 | int filter_hash, int inc) | |
1889 | { | |
1890 | struct ftrace_ops *op; | |
1891 | ||
1892 | __ftrace_hash_rec_update(ops, filter_hash, inc); | |
1893 | ||
1894 | if (ops->func_hash != &global_ops.local_hash) | |
1895 | return; | |
1896 | ||
1897 | /* | |
1898 | * If the ops shares the global_ops hash, then we need to update | |
1899 | * all ops that are enabled and use this hash. | |
1900 | */ | |
1901 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1902 | /* Already done */ | |
1903 | if (op == ops) | |
1904 | continue; | |
1905 | if (op->func_hash == &global_ops.local_hash) | |
1906 | __ftrace_hash_rec_update(op, filter_hash, inc); | |
1907 | } while_for_each_ftrace_op(op); | |
1908 | } | |
1909 | ||
1910 | static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, | |
1911 | int filter_hash) | |
1912 | { | |
1913 | ftrace_hash_rec_update_modify(ops, filter_hash, 0); | |
1914 | } | |
1915 | ||
1916 | static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, | |
1917 | int filter_hash) | |
1918 | { | |
1919 | ftrace_hash_rec_update_modify(ops, filter_hash, 1); | |
1920 | } | |
1921 | ||
f8b8be8a MH |
1922 | /* |
1923 | * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK | |
1924 | * or no-needed to update, -EBUSY if it detects a conflict of the flag | |
1925 | * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs. | |
1926 | * Note that old_hash and new_hash has below meanings | |
1927 | * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected) | |
1928 | * - If the hash is EMPTY_HASH, it hits nothing | |
1929 | * - Anything else hits the recs which match the hash entries. | |
53cd885b SL |
1930 | * |
1931 | * DIRECT ops does not have IPMODIFY flag, but we still need to check it | |
1932 | * against functions with FTRACE_FL_IPMODIFY. If there is any overlap, call | |
1933 | * ops_func(SHARE_IPMODIFY_SELF) to make sure current ops can share with | |
1934 | * IPMODIFY. If ops_func(SHARE_IPMODIFY_SELF) returns non-zero, propagate | |
1935 | * the return value to the caller and eventually to the owner of the DIRECT | |
1936 | * ops. | |
f8b8be8a MH |
1937 | */ |
1938 | static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops, | |
1939 | struct ftrace_hash *old_hash, | |
1940 | struct ftrace_hash *new_hash) | |
1941 | { | |
1942 | struct ftrace_page *pg; | |
1943 | struct dyn_ftrace *rec, *end = NULL; | |
1944 | int in_old, in_new; | |
53cd885b | 1945 | bool is_ipmodify, is_direct; |
f8b8be8a MH |
1946 | |
1947 | /* Only update if the ops has been registered */ | |
1948 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
1949 | return 0; | |
1950 | ||
53cd885b SL |
1951 | is_ipmodify = ops->flags & FTRACE_OPS_FL_IPMODIFY; |
1952 | is_direct = ops->flags & FTRACE_OPS_FL_DIRECT; | |
1953 | ||
1954 | /* neither IPMODIFY nor DIRECT, skip */ | |
1955 | if (!is_ipmodify && !is_direct) | |
1956 | return 0; | |
1957 | ||
1958 | if (WARN_ON_ONCE(is_ipmodify && is_direct)) | |
f8b8be8a MH |
1959 | return 0; |
1960 | ||
1961 | /* | |
53cd885b SL |
1962 | * Since the IPMODIFY and DIRECT are very address sensitive |
1963 | * actions, we do not allow ftrace_ops to set all functions to new | |
1964 | * hash. | |
f8b8be8a MH |
1965 | */ |
1966 | if (!new_hash || !old_hash) | |
1967 | return -EINVAL; | |
1968 | ||
1969 | /* Update rec->flags */ | |
1970 | do_for_each_ftrace_rec(pg, rec) { | |
546fece4 SRRH |
1971 | |
1972 | if (rec->flags & FTRACE_FL_DISABLED) | |
1973 | continue; | |
1974 | ||
f8b8be8a MH |
1975 | /* We need to update only differences of filter_hash */ |
1976 | in_old = !!ftrace_lookup_ip(old_hash, rec->ip); | |
1977 | in_new = !!ftrace_lookup_ip(new_hash, rec->ip); | |
1978 | if (in_old == in_new) | |
1979 | continue; | |
1980 | ||
1981 | if (in_new) { | |
53cd885b SL |
1982 | if (rec->flags & FTRACE_FL_IPMODIFY) { |
1983 | int ret; | |
1984 | ||
1985 | /* Cannot have two ipmodify on same rec */ | |
1986 | if (is_ipmodify) | |
1987 | goto rollback; | |
1988 | ||
1989 | FTRACE_WARN_ON(rec->flags & FTRACE_FL_DIRECT); | |
1990 | ||
1991 | /* | |
1992 | * Another ops with IPMODIFY is already | |
1993 | * attached. We are now attaching a direct | |
1994 | * ops. Run SHARE_IPMODIFY_SELF, to check | |
1995 | * whether sharing is supported. | |
1996 | */ | |
1997 | if (!ops->ops_func) | |
1998 | return -EBUSY; | |
1999 | ret = ops->ops_func(ops, FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_SELF); | |
2000 | if (ret) | |
2001 | return ret; | |
2002 | } else if (is_ipmodify) { | |
2003 | rec->flags |= FTRACE_FL_IPMODIFY; | |
2004 | } | |
2005 | } else if (is_ipmodify) { | |
f8b8be8a | 2006 | rec->flags &= ~FTRACE_FL_IPMODIFY; |
53cd885b | 2007 | } |
f8b8be8a MH |
2008 | } while_for_each_ftrace_rec(); |
2009 | ||
2010 | return 0; | |
2011 | ||
2012 | rollback: | |
2013 | end = rec; | |
2014 | ||
2015 | /* Roll back what we did above */ | |
2016 | do_for_each_ftrace_rec(pg, rec) { | |
546fece4 SRRH |
2017 | |
2018 | if (rec->flags & FTRACE_FL_DISABLED) | |
2019 | continue; | |
2020 | ||
f8b8be8a MH |
2021 | if (rec == end) |
2022 | goto err_out; | |
2023 | ||
2024 | in_old = !!ftrace_lookup_ip(old_hash, rec->ip); | |
2025 | in_new = !!ftrace_lookup_ip(new_hash, rec->ip); | |
2026 | if (in_old == in_new) | |
2027 | continue; | |
2028 | ||
2029 | if (in_new) | |
2030 | rec->flags &= ~FTRACE_FL_IPMODIFY; | |
2031 | else | |
2032 | rec->flags |= FTRACE_FL_IPMODIFY; | |
2033 | } while_for_each_ftrace_rec(); | |
2034 | ||
2035 | err_out: | |
2036 | return -EBUSY; | |
2037 | } | |
2038 | ||
2039 | static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops) | |
2040 | { | |
2041 | struct ftrace_hash *hash = ops->func_hash->filter_hash; | |
2042 | ||
2043 | if (ftrace_hash_empty(hash)) | |
2044 | hash = NULL; | |
2045 | ||
2046 | return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash); | |
2047 | } | |
2048 | ||
2049 | /* Disabling always succeeds */ | |
2050 | static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops) | |
2051 | { | |
2052 | struct ftrace_hash *hash = ops->func_hash->filter_hash; | |
2053 | ||
2054 | if (ftrace_hash_empty(hash)) | |
2055 | hash = NULL; | |
2056 | ||
2057 | __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH); | |
2058 | } | |
2059 | ||
2060 | static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, | |
2061 | struct ftrace_hash *new_hash) | |
2062 | { | |
2063 | struct ftrace_hash *old_hash = ops->func_hash->filter_hash; | |
2064 | ||
2065 | if (ftrace_hash_empty(old_hash)) | |
2066 | old_hash = NULL; | |
2067 | ||
2068 | if (ftrace_hash_empty(new_hash)) | |
2069 | new_hash = NULL; | |
2070 | ||
2071 | return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash); | |
2072 | } | |
2073 | ||
b05086c7 | 2074 | static void print_ip_ins(const char *fmt, const unsigned char *p) |
b17e8a37 | 2075 | { |
6c14133d | 2076 | char ins[MCOUNT_INSN_SIZE]; |
b17e8a37 | 2077 | |
6c14133d SRV |
2078 | if (copy_from_kernel_nofault(ins, p, MCOUNT_INSN_SIZE)) { |
2079 | printk(KERN_CONT "%s[FAULT] %px\n", fmt, p); | |
2080 | return; | |
2081 | } | |
2082 | ||
b17e8a37 | 2083 | printk(KERN_CONT "%s", fmt); |
30f7d1ca | 2084 | pr_cont("%*phC", MCOUNT_INSN_SIZE, ins); |
b17e8a37 SR |
2085 | } |
2086 | ||
02a392a0 | 2087 | enum ftrace_bug_type ftrace_bug_type; |
b05086c7 | 2088 | const void *ftrace_expected; |
02a392a0 SRRH |
2089 | |
2090 | static void print_bug_type(void) | |
2091 | { | |
2092 | switch (ftrace_bug_type) { | |
2093 | case FTRACE_BUG_UNKNOWN: | |
2094 | break; | |
2095 | case FTRACE_BUG_INIT: | |
2096 | pr_info("Initializing ftrace call sites\n"); | |
2097 | break; | |
2098 | case FTRACE_BUG_NOP: | |
2099 | pr_info("Setting ftrace call site to NOP\n"); | |
2100 | break; | |
2101 | case FTRACE_BUG_CALL: | |
2102 | pr_info("Setting ftrace call site to call ftrace function\n"); | |
2103 | break; | |
2104 | case FTRACE_BUG_UPDATE: | |
2105 | pr_info("Updating ftrace call site to call a different ftrace function\n"); | |
2106 | break; | |
2107 | } | |
2108 | } | |
2109 | ||
c88fd863 SR |
2110 | /** |
2111 | * ftrace_bug - report and shutdown function tracer | |
2112 | * @failed: The failed type (EFAULT, EINVAL, EPERM) | |
4fd3279b | 2113 | * @rec: The record that failed |
c88fd863 SR |
2114 | * |
2115 | * The arch code that enables or disables the function tracing | |
2116 | * can call ftrace_bug() when it has detected a problem in | |
2117 | * modifying the code. @failed should be one of either: | |
2118 | * EFAULT - if the problem happens on reading the @ip address | |
2119 | * EINVAL - if what is read at @ip is not what was expected | |
9efb85c5 | 2120 | * EPERM - if the problem happens on writing to the @ip address |
c88fd863 | 2121 | */ |
4fd3279b | 2122 | void ftrace_bug(int failed, struct dyn_ftrace *rec) |
b17e8a37 | 2123 | { |
4fd3279b SRRH |
2124 | unsigned long ip = rec ? rec->ip : 0; |
2125 | ||
c143b775 CJ |
2126 | pr_info("------------[ ftrace bug ]------------\n"); |
2127 | ||
b17e8a37 SR |
2128 | switch (failed) { |
2129 | case -EFAULT: | |
b17e8a37 | 2130 | pr_info("ftrace faulted on modifying "); |
2062a4e8 | 2131 | print_ip_sym(KERN_INFO, ip); |
b17e8a37 SR |
2132 | break; |
2133 | case -EINVAL: | |
b17e8a37 | 2134 | pr_info("ftrace failed to modify "); |
2062a4e8 | 2135 | print_ip_sym(KERN_INFO, ip); |
b05086c7 | 2136 | print_ip_ins(" actual: ", (unsigned char *)ip); |
4fd3279b | 2137 | pr_cont("\n"); |
b05086c7 SRRH |
2138 | if (ftrace_expected) { |
2139 | print_ip_ins(" expected: ", ftrace_expected); | |
2140 | pr_cont("\n"); | |
2141 | } | |
b17e8a37 SR |
2142 | break; |
2143 | case -EPERM: | |
b17e8a37 | 2144 | pr_info("ftrace faulted on writing "); |
2062a4e8 | 2145 | print_ip_sym(KERN_INFO, ip); |
b17e8a37 SR |
2146 | break; |
2147 | default: | |
b17e8a37 | 2148 | pr_info("ftrace faulted on unknown error "); |
2062a4e8 | 2149 | print_ip_sym(KERN_INFO, ip); |
b17e8a37 | 2150 | } |
02a392a0 | 2151 | print_bug_type(); |
4fd3279b SRRH |
2152 | if (rec) { |
2153 | struct ftrace_ops *ops = NULL; | |
2154 | ||
2155 | pr_info("ftrace record flags: %lx\n", rec->flags); | |
cbad0fb2 MR |
2156 | pr_cont(" (%ld)%s%s", ftrace_rec_count(rec), |
2157 | rec->flags & FTRACE_FL_REGS ? " R" : " ", | |
2158 | rec->flags & FTRACE_FL_CALL_OPS ? " O" : " "); | |
4fd3279b SRRH |
2159 | if (rec->flags & FTRACE_FL_TRAMP_EN) { |
2160 | ops = ftrace_find_tramp_ops_any(rec); | |
39daa7b9 SRRH |
2161 | if (ops) { |
2162 | do { | |
2163 | pr_cont("\ttramp: %pS (%pS)", | |
2164 | (void *)ops->trampoline, | |
2165 | (void *)ops->func); | |
2166 | ops = ftrace_find_tramp_ops_next(rec, ops); | |
2167 | } while (ops); | |
2168 | } else | |
4fd3279b SRRH |
2169 | pr_cont("\ttramp: ERROR!"); |
2170 | ||
2171 | } | |
2172 | ip = ftrace_get_addr_curr(rec); | |
39daa7b9 | 2173 | pr_cont("\n expected tramp: %lx\n", ip); |
4fd3279b | 2174 | } |
c143b775 CJ |
2175 | |
2176 | FTRACE_WARN_ON_ONCE(1); | |
b17e8a37 SR |
2177 | } |
2178 | ||
7375dca1 | 2179 | static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update) |
5072c59f | 2180 | { |
64fbcd16 | 2181 | unsigned long flag = 0UL; |
e7d3737e | 2182 | |
02a392a0 SRRH |
2183 | ftrace_bug_type = FTRACE_BUG_UNKNOWN; |
2184 | ||
cf04f2d5 | 2185 | if (skip_record(rec)) |
b7ffffbb SRRH |
2186 | return FTRACE_UPDATE_IGNORE; |
2187 | ||
982c350b | 2188 | /* |
30fb6aa7 | 2189 | * If we are updating calls: |
982c350b | 2190 | * |
ed926f9b SR |
2191 | * If the record has a ref count, then we need to enable it |
2192 | * because someone is using it. | |
982c350b | 2193 | * |
ed926f9b SR |
2194 | * Otherwise we make sure its disabled. |
2195 | * | |
30fb6aa7 | 2196 | * If we are disabling calls, then disable all records that |
ed926f9b | 2197 | * are enabled. |
982c350b | 2198 | */ |
0376bde1 | 2199 | if (enable && ftrace_rec_count(rec)) |
ed926f9b | 2200 | flag = FTRACE_FL_ENABLED; |
982c350b | 2201 | |
08f6fba5 | 2202 | /* |
79922b80 SRRH |
2203 | * If enabling and the REGS flag does not match the REGS_EN, or |
2204 | * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore | |
2205 | * this record. Set flags to fail the compare against ENABLED. | |
763e34e7 | 2206 | * Same for direct calls. |
08f6fba5 | 2207 | */ |
79922b80 | 2208 | if (flag) { |
763e34e7 | 2209 | if (!(rec->flags & FTRACE_FL_REGS) != |
79922b80 SRRH |
2210 | !(rec->flags & FTRACE_FL_REGS_EN)) |
2211 | flag |= FTRACE_FL_REGS; | |
2212 | ||
763e34e7 | 2213 | if (!(rec->flags & FTRACE_FL_TRAMP) != |
79922b80 SRRH |
2214 | !(rec->flags & FTRACE_FL_TRAMP_EN)) |
2215 | flag |= FTRACE_FL_TRAMP; | |
763e34e7 SRV |
2216 | |
2217 | /* | |
2218 | * Direct calls are special, as count matters. | |
2219 | * We must test the record for direct, if the | |
2220 | * DIRECT and DIRECT_EN do not match, but only | |
2221 | * if the count is 1. That's because, if the | |
2222 | * count is something other than one, we do not | |
2223 | * want the direct enabled (it will be done via the | |
2224 | * direct helper). But if DIRECT_EN is set, and | |
2225 | * the count is not one, we need to clear it. | |
cbad0fb2 | 2226 | * |
763e34e7 SRV |
2227 | */ |
2228 | if (ftrace_rec_count(rec) == 1) { | |
2229 | if (!(rec->flags & FTRACE_FL_DIRECT) != | |
2230 | !(rec->flags & FTRACE_FL_DIRECT_EN)) | |
2231 | flag |= FTRACE_FL_DIRECT; | |
2232 | } else if (rec->flags & FTRACE_FL_DIRECT_EN) { | |
2233 | flag |= FTRACE_FL_DIRECT; | |
2234 | } | |
cbad0fb2 MR |
2235 | |
2236 | /* | |
2237 | * Ops calls are special, as count matters. | |
2238 | * As with direct calls, they must only be enabled when count | |
2239 | * is one, otherwise they'll be handled via the list ops. | |
2240 | */ | |
2241 | if (ftrace_rec_count(rec) == 1) { | |
2242 | if (!(rec->flags & FTRACE_FL_CALL_OPS) != | |
2243 | !(rec->flags & FTRACE_FL_CALL_OPS_EN)) | |
2244 | flag |= FTRACE_FL_CALL_OPS; | |
2245 | } else if (rec->flags & FTRACE_FL_CALL_OPS_EN) { | |
2246 | flag |= FTRACE_FL_CALL_OPS; | |
2247 | } | |
79922b80 | 2248 | } |
08f6fba5 | 2249 | |
64fbcd16 XG |
2250 | /* If the state of this record hasn't changed, then do nothing */ |
2251 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
c88fd863 | 2252 | return FTRACE_UPDATE_IGNORE; |
982c350b | 2253 | |
64fbcd16 | 2254 | if (flag) { |
08f6fba5 SR |
2255 | /* Save off if rec is being enabled (for return value) */ |
2256 | flag ^= rec->flags & FTRACE_FL_ENABLED; | |
2257 | ||
2258 | if (update) { | |
c88fd863 | 2259 | rec->flags |= FTRACE_FL_ENABLED; |
08f6fba5 SR |
2260 | if (flag & FTRACE_FL_REGS) { |
2261 | if (rec->flags & FTRACE_FL_REGS) | |
2262 | rec->flags |= FTRACE_FL_REGS_EN; | |
2263 | else | |
2264 | rec->flags &= ~FTRACE_FL_REGS_EN; | |
2265 | } | |
79922b80 SRRH |
2266 | if (flag & FTRACE_FL_TRAMP) { |
2267 | if (rec->flags & FTRACE_FL_TRAMP) | |
2268 | rec->flags |= FTRACE_FL_TRAMP_EN; | |
2269 | else | |
2270 | rec->flags &= ~FTRACE_FL_TRAMP_EN; | |
2271 | } | |
d19ad077 | 2272 | |
763e34e7 SRV |
2273 | if (flag & FTRACE_FL_DIRECT) { |
2274 | /* | |
2275 | * If there's only one user (direct_ops helper) | |
2276 | * then we can call the direct function | |
2277 | * directly (no ftrace trampoline). | |
2278 | */ | |
2279 | if (ftrace_rec_count(rec) == 1) { | |
2280 | if (rec->flags & FTRACE_FL_DIRECT) | |
2281 | rec->flags |= FTRACE_FL_DIRECT_EN; | |
2282 | else | |
2283 | rec->flags &= ~FTRACE_FL_DIRECT_EN; | |
2284 | } else { | |
2285 | /* | |
2286 | * Can only call directly if there's | |
2287 | * only one callback to the function. | |
2288 | */ | |
2289 | rec->flags &= ~FTRACE_FL_DIRECT_EN; | |
2290 | } | |
2291 | } | |
cbad0fb2 MR |
2292 | |
2293 | if (flag & FTRACE_FL_CALL_OPS) { | |
2294 | if (ftrace_rec_count(rec) == 1) { | |
2295 | if (rec->flags & FTRACE_FL_CALL_OPS) | |
2296 | rec->flags |= FTRACE_FL_CALL_OPS_EN; | |
2297 | else | |
2298 | rec->flags &= ~FTRACE_FL_CALL_OPS_EN; | |
2299 | } else { | |
2300 | /* | |
2301 | * Can only call directly if there's | |
2302 | * only one set of associated ops. | |
2303 | */ | |
2304 | rec->flags &= ~FTRACE_FL_CALL_OPS_EN; | |
2305 | } | |
2306 | } | |
08f6fba5 SR |
2307 | } |
2308 | ||
2309 | /* | |
2310 | * If this record is being updated from a nop, then | |
2311 | * return UPDATE_MAKE_CALL. | |
08f6fba5 SR |
2312 | * Otherwise, |
2313 | * return UPDATE_MODIFY_CALL to tell the caller to convert | |
f1b2f2bd | 2314 | * from the save regs, to a non-save regs function or |
79922b80 | 2315 | * vice versa, or from a trampoline call. |
08f6fba5 | 2316 | */ |
02a392a0 SRRH |
2317 | if (flag & FTRACE_FL_ENABLED) { |
2318 | ftrace_bug_type = FTRACE_BUG_CALL; | |
08f6fba5 | 2319 | return FTRACE_UPDATE_MAKE_CALL; |
02a392a0 | 2320 | } |
f1b2f2bd | 2321 | |
02a392a0 | 2322 | ftrace_bug_type = FTRACE_BUG_UPDATE; |
f1b2f2bd | 2323 | return FTRACE_UPDATE_MODIFY_CALL; |
c88fd863 SR |
2324 | } |
2325 | ||
08f6fba5 SR |
2326 | if (update) { |
2327 | /* If there's no more users, clear all flags */ | |
0376bde1 | 2328 | if (!ftrace_rec_count(rec)) |
cf04f2d5 | 2329 | rec->flags &= FTRACE_FL_DISABLED; |
08f6fba5 | 2330 | else |
b24d443b SRRH |
2331 | /* |
2332 | * Just disable the record, but keep the ops TRAMP | |
2333 | * and REGS states. The _EN flags must be disabled though. | |
2334 | */ | |
2335 | rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN | | |
cbad0fb2 MR |
2336 | FTRACE_FL_REGS_EN | FTRACE_FL_DIRECT_EN | |
2337 | FTRACE_FL_CALL_OPS_EN); | |
08f6fba5 | 2338 | } |
c88fd863 | 2339 | |
02a392a0 | 2340 | ftrace_bug_type = FTRACE_BUG_NOP; |
c88fd863 SR |
2341 | return FTRACE_UPDATE_MAKE_NOP; |
2342 | } | |
2343 | ||
2344 | /** | |
6130722f | 2345 | * ftrace_update_record - set a record that now is tracing or not |
c88fd863 | 2346 | * @rec: the record to update |
7375dca1 | 2347 | * @enable: set to true if the record is tracing, false to force disable |
c88fd863 SR |
2348 | * |
2349 | * The records that represent all functions that can be traced need | |
2350 | * to be updated when tracing has been enabled. | |
2351 | */ | |
7375dca1 | 2352 | int ftrace_update_record(struct dyn_ftrace *rec, bool enable) |
c88fd863 | 2353 | { |
7375dca1 | 2354 | return ftrace_check_record(rec, enable, true); |
c88fd863 SR |
2355 | } |
2356 | ||
2357 | /** | |
6130722f | 2358 | * ftrace_test_record - check if the record has been enabled or not |
c88fd863 | 2359 | * @rec: the record to test |
7375dca1 | 2360 | * @enable: set to true to check if enabled, false if it is disabled |
c88fd863 SR |
2361 | * |
2362 | * The arch code may need to test if a record is already set to | |
2363 | * tracing to determine how to modify the function code that it | |
2364 | * represents. | |
2365 | */ | |
7375dca1 | 2366 | int ftrace_test_record(struct dyn_ftrace *rec, bool enable) |
c88fd863 | 2367 | { |
7375dca1 | 2368 | return ftrace_check_record(rec, enable, false); |
c88fd863 SR |
2369 | } |
2370 | ||
5fecaa04 SRRH |
2371 | static struct ftrace_ops * |
2372 | ftrace_find_tramp_ops_any(struct dyn_ftrace *rec) | |
2373 | { | |
2374 | struct ftrace_ops *op; | |
fef5aeee | 2375 | unsigned long ip = rec->ip; |
5fecaa04 SRRH |
2376 | |
2377 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2378 | ||
2379 | if (!op->trampoline) | |
2380 | continue; | |
2381 | ||
fef5aeee | 2382 | if (hash_contains_ip(ip, op->func_hash)) |
5fecaa04 SRRH |
2383 | return op; |
2384 | } while_for_each_ftrace_op(op); | |
2385 | ||
2386 | return NULL; | |
2387 | } | |
2388 | ||
4c75b0ff NR |
2389 | static struct ftrace_ops * |
2390 | ftrace_find_tramp_ops_any_other(struct dyn_ftrace *rec, struct ftrace_ops *op_exclude) | |
2391 | { | |
2392 | struct ftrace_ops *op; | |
2393 | unsigned long ip = rec->ip; | |
2394 | ||
2395 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2396 | ||
2397 | if (op == op_exclude || !op->trampoline) | |
2398 | continue; | |
2399 | ||
2400 | if (hash_contains_ip(ip, op->func_hash)) | |
2401 | return op; | |
2402 | } while_for_each_ftrace_op(op); | |
2403 | ||
2404 | return NULL; | |
2405 | } | |
2406 | ||
39daa7b9 SRRH |
2407 | static struct ftrace_ops * |
2408 | ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, | |
2409 | struct ftrace_ops *op) | |
2410 | { | |
2411 | unsigned long ip = rec->ip; | |
2412 | ||
2413 | while_for_each_ftrace_op(op) { | |
2414 | ||
2415 | if (!op->trampoline) | |
2416 | continue; | |
2417 | ||
2418 | if (hash_contains_ip(ip, op->func_hash)) | |
2419 | return op; | |
026bb845 | 2420 | } |
39daa7b9 SRRH |
2421 | |
2422 | return NULL; | |
2423 | } | |
2424 | ||
79922b80 SRRH |
2425 | static struct ftrace_ops * |
2426 | ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec) | |
2427 | { | |
2428 | struct ftrace_ops *op; | |
fef5aeee | 2429 | unsigned long ip = rec->ip; |
79922b80 | 2430 | |
fef5aeee SRRH |
2431 | /* |
2432 | * Need to check removed ops first. | |
2433 | * If they are being removed, and this rec has a tramp, | |
2434 | * and this rec is in the ops list, then it would be the | |
2435 | * one with the tramp. | |
2436 | */ | |
2437 | if (removed_ops) { | |
2438 | if (hash_contains_ip(ip, &removed_ops->old_hash)) | |
79922b80 SRRH |
2439 | return removed_ops; |
2440 | } | |
2441 | ||
fef5aeee SRRH |
2442 | /* |
2443 | * Need to find the current trampoline for a rec. | |
2444 | * Now, a trampoline is only attached to a rec if there | |
2445 | * was a single 'ops' attached to it. But this can be called | |
2446 | * when we are adding another op to the rec or removing the | |
2447 | * current one. Thus, if the op is being added, we can | |
2448 | * ignore it because it hasn't attached itself to the rec | |
4fc40904 SRRH |
2449 | * yet. |
2450 | * | |
2451 | * If an ops is being modified (hooking to different functions) | |
2452 | * then we don't care about the new functions that are being | |
2453 | * added, just the old ones (that are probably being removed). | |
2454 | * | |
2455 | * If we are adding an ops to a function that already is using | |
2456 | * a trampoline, it needs to be removed (trampolines are only | |
2457 | * for single ops connected), then an ops that is not being | |
2458 | * modified also needs to be checked. | |
fef5aeee | 2459 | */ |
79922b80 | 2460 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
fef5aeee SRRH |
2461 | |
2462 | if (!op->trampoline) | |
2463 | continue; | |
2464 | ||
2465 | /* | |
2466 | * If the ops is being added, it hasn't gotten to | |
2467 | * the point to be removed from this tree yet. | |
2468 | */ | |
2469 | if (op->flags & FTRACE_OPS_FL_ADDING) | |
79922b80 SRRH |
2470 | continue; |
2471 | ||
4fc40904 | 2472 | |
fef5aeee | 2473 | /* |
4fc40904 SRRH |
2474 | * If the ops is being modified and is in the old |
2475 | * hash, then it is probably being removed from this | |
2476 | * function. | |
fef5aeee | 2477 | */ |
fef5aeee SRRH |
2478 | if ((op->flags & FTRACE_OPS_FL_MODIFYING) && |
2479 | hash_contains_ip(ip, &op->old_hash)) | |
79922b80 | 2480 | return op; |
4fc40904 SRRH |
2481 | /* |
2482 | * If the ops is not being added or modified, and it's | |
2483 | * in its normal filter hash, then this must be the one | |
2484 | * we want! | |
2485 | */ | |
2486 | if (!(op->flags & FTRACE_OPS_FL_MODIFYING) && | |
2487 | hash_contains_ip(ip, op->func_hash)) | |
2488 | return op; | |
79922b80 SRRH |
2489 | |
2490 | } while_for_each_ftrace_op(op); | |
2491 | ||
2492 | return NULL; | |
2493 | } | |
2494 | ||
2495 | static struct ftrace_ops * | |
2496 | ftrace_find_tramp_ops_new(struct dyn_ftrace *rec) | |
2497 | { | |
2498 | struct ftrace_ops *op; | |
fef5aeee | 2499 | unsigned long ip = rec->ip; |
79922b80 SRRH |
2500 | |
2501 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2502 | /* pass rec in as regs to have non-NULL val */ | |
fef5aeee | 2503 | if (hash_contains_ip(ip, op->func_hash)) |
79922b80 SRRH |
2504 | return op; |
2505 | } while_for_each_ftrace_op(op); | |
2506 | ||
2507 | return NULL; | |
2508 | } | |
2509 | ||
cbad0fb2 MR |
2510 | struct ftrace_ops * |
2511 | ftrace_find_unique_ops(struct dyn_ftrace *rec) | |
2512 | { | |
2513 | struct ftrace_ops *op, *found = NULL; | |
2514 | unsigned long ip = rec->ip; | |
2515 | ||
2516 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2517 | ||
2518 | if (hash_contains_ip(ip, op->func_hash)) { | |
2519 | if (found) | |
2520 | return NULL; | |
2521 | found = op; | |
2522 | } | |
2523 | ||
2524 | } while_for_each_ftrace_op(op); | |
2525 | ||
2526 | return found; | |
2527 | } | |
2528 | ||
763e34e7 SRV |
2529 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS |
2530 | /* Protected by rcu_tasks for reading, and direct_mutex for writing */ | |
2531 | static struct ftrace_hash *direct_functions = EMPTY_HASH; | |
2532 | static DEFINE_MUTEX(direct_mutex); | |
a3ad1a7e | 2533 | int ftrace_direct_func_count; |
763e34e7 SRV |
2534 | |
2535 | /* | |
2536 | * Search the direct_functions hash to see if the given instruction pointer | |
2537 | * has a direct caller attached to it. | |
2538 | */ | |
ff205766 | 2539 | unsigned long ftrace_find_rec_direct(unsigned long ip) |
763e34e7 SRV |
2540 | { |
2541 | struct ftrace_func_entry *entry; | |
2542 | ||
2543 | entry = __ftrace_lookup_ip(direct_functions, ip); | |
2544 | if (!entry) | |
2545 | return 0; | |
2546 | ||
2547 | return entry->direct; | |
2548 | } | |
2549 | ||
1904a814 JO |
2550 | static struct ftrace_func_entry* |
2551 | ftrace_add_rec_direct(unsigned long ip, unsigned long addr, | |
2552 | struct ftrace_hash **free_hash) | |
2553 | { | |
2554 | struct ftrace_func_entry *entry; | |
2555 | ||
2556 | if (ftrace_hash_empty(direct_functions) || | |
2557 | direct_functions->count > 2 * (1 << direct_functions->size_bits)) { | |
2558 | struct ftrace_hash *new_hash; | |
2559 | int size = ftrace_hash_empty(direct_functions) ? 0 : | |
2560 | direct_functions->count + 1; | |
2561 | ||
2562 | if (size < 32) | |
2563 | size = 32; | |
2564 | ||
2565 | new_hash = dup_hash(direct_functions, size); | |
2566 | if (!new_hash) | |
2567 | return NULL; | |
2568 | ||
2569 | *free_hash = direct_functions; | |
2570 | direct_functions = new_hash; | |
2571 | } | |
2572 | ||
2573 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
2574 | if (!entry) | |
2575 | return NULL; | |
2576 | ||
2577 | entry->ip = ip; | |
2578 | entry->direct = addr; | |
2579 | __add_hash_entry(direct_functions, entry); | |
2580 | return entry; | |
2581 | } | |
2582 | ||
763e34e7 | 2583 | static void call_direct_funcs(unsigned long ip, unsigned long pip, |
d19ad077 | 2584 | struct ftrace_ops *ops, struct ftrace_regs *fregs) |
763e34e7 SRV |
2585 | { |
2586 | unsigned long addr; | |
2587 | ||
ff205766 | 2588 | addr = ftrace_find_rec_direct(ip); |
763e34e7 SRV |
2589 | if (!addr) |
2590 | return; | |
2591 | ||
9705bc70 | 2592 | arch_ftrace_set_direct_caller(fregs, addr); |
763e34e7 SRV |
2593 | } |
2594 | ||
87325655 | 2595 | static struct ftrace_ops direct_ops = { |
763e34e7 | 2596 | .func = call_direct_funcs, |
53cd885b | 2597 | .flags = FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_REGS |
763e34e7 | 2598 | | FTRACE_OPS_FL_PERMANENT, |
5da7cd11 SRV |
2599 | /* |
2600 | * By declaring the main trampoline as this trampoline | |
2601 | * it will never have one allocated for it. Allocated | |
2602 | * trampolines should not call direct functions. | |
2603 | * The direct_ops should only be called by the builtin | |
2604 | * ftrace_regs_caller trampoline. | |
2605 | */ | |
2606 | .trampoline = FTRACE_REGS_ADDR, | |
763e34e7 | 2607 | }; |
763e34e7 SRV |
2608 | #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ |
2609 | ||
7413af1f SRRH |
2610 | /** |
2611 | * ftrace_get_addr_new - Get the call address to set to | |
2612 | * @rec: The ftrace record descriptor | |
2613 | * | |
2614 | * If the record has the FTRACE_FL_REGS set, that means that it | |
2615 | * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS | |
5c8c206e | 2616 | * is not set, then it wants to convert to the normal callback. |
7413af1f SRRH |
2617 | * |
2618 | * Returns the address of the trampoline to set to | |
2619 | */ | |
2620 | unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec) | |
2621 | { | |
79922b80 | 2622 | struct ftrace_ops *ops; |
763e34e7 SRV |
2623 | unsigned long addr; |
2624 | ||
2625 | if ((rec->flags & FTRACE_FL_DIRECT) && | |
2626 | (ftrace_rec_count(rec) == 1)) { | |
ff205766 | 2627 | addr = ftrace_find_rec_direct(rec->ip); |
763e34e7 SRV |
2628 | if (addr) |
2629 | return addr; | |
2630 | WARN_ON_ONCE(1); | |
2631 | } | |
79922b80 SRRH |
2632 | |
2633 | /* Trampolines take precedence over regs */ | |
2634 | if (rec->flags & FTRACE_FL_TRAMP) { | |
2635 | ops = ftrace_find_tramp_ops_new(rec); | |
2636 | if (FTRACE_WARN_ON(!ops || !ops->trampoline)) { | |
bce0b6c5 SRRH |
2637 | pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n", |
2638 | (void *)rec->ip, (void *)rec->ip, rec->flags); | |
79922b80 SRRH |
2639 | /* Ftrace is shutting down, return anything */ |
2640 | return (unsigned long)FTRACE_ADDR; | |
2641 | } | |
2642 | return ops->trampoline; | |
2643 | } | |
2644 | ||
7413af1f SRRH |
2645 | if (rec->flags & FTRACE_FL_REGS) |
2646 | return (unsigned long)FTRACE_REGS_ADDR; | |
2647 | else | |
2648 | return (unsigned long)FTRACE_ADDR; | |
2649 | } | |
2650 | ||
2651 | /** | |
2652 | * ftrace_get_addr_curr - Get the call address that is already there | |
2653 | * @rec: The ftrace record descriptor | |
2654 | * | |
2655 | * The FTRACE_FL_REGS_EN is set when the record already points to | |
2656 | * a function that saves all the regs. Basically the '_EN' version | |
2657 | * represents the current state of the function. | |
2658 | * | |
2659 | * Returns the address of the trampoline that is currently being called | |
2660 | */ | |
2661 | unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec) | |
2662 | { | |
79922b80 | 2663 | struct ftrace_ops *ops; |
763e34e7 SRV |
2664 | unsigned long addr; |
2665 | ||
2666 | /* Direct calls take precedence over trampolines */ | |
2667 | if (rec->flags & FTRACE_FL_DIRECT_EN) { | |
ff205766 | 2668 | addr = ftrace_find_rec_direct(rec->ip); |
763e34e7 SRV |
2669 | if (addr) |
2670 | return addr; | |
2671 | WARN_ON_ONCE(1); | |
2672 | } | |
79922b80 SRRH |
2673 | |
2674 | /* Trampolines take precedence over regs */ | |
2675 | if (rec->flags & FTRACE_FL_TRAMP_EN) { | |
2676 | ops = ftrace_find_tramp_ops_curr(rec); | |
2677 | if (FTRACE_WARN_ON(!ops)) { | |
a395d6a7 JP |
2678 | pr_warn("Bad trampoline accounting at: %p (%pS)\n", |
2679 | (void *)rec->ip, (void *)rec->ip); | |
79922b80 SRRH |
2680 | /* Ftrace is shutting down, return anything */ |
2681 | return (unsigned long)FTRACE_ADDR; | |
2682 | } | |
2683 | return ops->trampoline; | |
2684 | } | |
2685 | ||
7413af1f SRRH |
2686 | if (rec->flags & FTRACE_FL_REGS_EN) |
2687 | return (unsigned long)FTRACE_REGS_ADDR; | |
2688 | else | |
2689 | return (unsigned long)FTRACE_ADDR; | |
2690 | } | |
2691 | ||
c88fd863 | 2692 | static int |
7375dca1 | 2693 | __ftrace_replace_code(struct dyn_ftrace *rec, bool enable) |
c88fd863 | 2694 | { |
08f6fba5 | 2695 | unsigned long ftrace_old_addr; |
c88fd863 SR |
2696 | unsigned long ftrace_addr; |
2697 | int ret; | |
2698 | ||
7c0868e0 | 2699 | ftrace_addr = ftrace_get_addr_new(rec); |
c88fd863 | 2700 | |
7c0868e0 SRRH |
2701 | /* This needs to be done before we call ftrace_update_record */ |
2702 | ftrace_old_addr = ftrace_get_addr_curr(rec); | |
2703 | ||
2704 | ret = ftrace_update_record(rec, enable); | |
08f6fba5 | 2705 | |
02a392a0 SRRH |
2706 | ftrace_bug_type = FTRACE_BUG_UNKNOWN; |
2707 | ||
c88fd863 SR |
2708 | switch (ret) { |
2709 | case FTRACE_UPDATE_IGNORE: | |
2710 | return 0; | |
2711 | ||
2712 | case FTRACE_UPDATE_MAKE_CALL: | |
02a392a0 | 2713 | ftrace_bug_type = FTRACE_BUG_CALL; |
64fbcd16 | 2714 | return ftrace_make_call(rec, ftrace_addr); |
c88fd863 SR |
2715 | |
2716 | case FTRACE_UPDATE_MAKE_NOP: | |
02a392a0 | 2717 | ftrace_bug_type = FTRACE_BUG_NOP; |
39b5552c | 2718 | return ftrace_make_nop(NULL, rec, ftrace_old_addr); |
08f6fba5 | 2719 | |
08f6fba5 | 2720 | case FTRACE_UPDATE_MODIFY_CALL: |
02a392a0 | 2721 | ftrace_bug_type = FTRACE_BUG_UPDATE; |
08f6fba5 | 2722 | return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr); |
5072c59f SR |
2723 | } |
2724 | ||
9efb85c5 | 2725 | return -1; /* unknown ftrace bug */ |
5072c59f SR |
2726 | } |
2727 | ||
a0572f68 | 2728 | void __weak ftrace_replace_code(int mod_flags) |
3c1720f0 | 2729 | { |
3c1720f0 SR |
2730 | struct dyn_ftrace *rec; |
2731 | struct ftrace_page *pg; | |
7375dca1 | 2732 | bool enable = mod_flags & FTRACE_MODIFY_ENABLE_FL; |
a0572f68 | 2733 | int schedulable = mod_flags & FTRACE_MODIFY_MAY_SLEEP_FL; |
6a24a244 | 2734 | int failed; |
3c1720f0 | 2735 | |
45a4a237 SR |
2736 | if (unlikely(ftrace_disabled)) |
2737 | return; | |
2738 | ||
265c831c | 2739 | do_for_each_ftrace_rec(pg, rec) { |
546fece4 | 2740 | |
cf04f2d5 | 2741 | if (skip_record(rec)) |
546fece4 SRRH |
2742 | continue; |
2743 | ||
e4f5d544 | 2744 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 2745 | if (failed) { |
4fd3279b | 2746 | ftrace_bug(failed, rec); |
3279ba37 SR |
2747 | /* Stop processing */ |
2748 | return; | |
3c1720f0 | 2749 | } |
a0572f68 SRV |
2750 | if (schedulable) |
2751 | cond_resched(); | |
265c831c | 2752 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
2753 | } |
2754 | ||
c88fd863 SR |
2755 | struct ftrace_rec_iter { |
2756 | struct ftrace_page *pg; | |
2757 | int index; | |
2758 | }; | |
2759 | ||
2760 | /** | |
6130722f | 2761 | * ftrace_rec_iter_start - start up iterating over traced functions |
c88fd863 SR |
2762 | * |
2763 | * Returns an iterator handle that is used to iterate over all | |
2764 | * the records that represent address locations where functions | |
2765 | * are traced. | |
2766 | * | |
2767 | * May return NULL if no records are available. | |
2768 | */ | |
2769 | struct ftrace_rec_iter *ftrace_rec_iter_start(void) | |
2770 | { | |
2771 | /* | |
2772 | * We only use a single iterator. | |
2773 | * Protected by the ftrace_lock mutex. | |
2774 | */ | |
2775 | static struct ftrace_rec_iter ftrace_rec_iter; | |
2776 | struct ftrace_rec_iter *iter = &ftrace_rec_iter; | |
2777 | ||
2778 | iter->pg = ftrace_pages_start; | |
2779 | iter->index = 0; | |
2780 | ||
2781 | /* Could have empty pages */ | |
2782 | while (iter->pg && !iter->pg->index) | |
2783 | iter->pg = iter->pg->next; | |
2784 | ||
2785 | if (!iter->pg) | |
2786 | return NULL; | |
2787 | ||
2788 | return iter; | |
2789 | } | |
2790 | ||
2791 | /** | |
6130722f | 2792 | * ftrace_rec_iter_next - get the next record to process. |
c88fd863 SR |
2793 | * @iter: The handle to the iterator. |
2794 | * | |
2795 | * Returns the next iterator after the given iterator @iter. | |
2796 | */ | |
2797 | struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) | |
2798 | { | |
2799 | iter->index++; | |
2800 | ||
2801 | if (iter->index >= iter->pg->index) { | |
2802 | iter->pg = iter->pg->next; | |
2803 | iter->index = 0; | |
2804 | ||
2805 | /* Could have empty pages */ | |
2806 | while (iter->pg && !iter->pg->index) | |
2807 | iter->pg = iter->pg->next; | |
2808 | } | |
2809 | ||
2810 | if (!iter->pg) | |
2811 | return NULL; | |
2812 | ||
2813 | return iter; | |
2814 | } | |
2815 | ||
2816 | /** | |
6130722f | 2817 | * ftrace_rec_iter_record - get the record at the iterator location |
c88fd863 SR |
2818 | * @iter: The current iterator location |
2819 | * | |
2820 | * Returns the record that the current @iter is at. | |
2821 | */ | |
2822 | struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) | |
2823 | { | |
2824 | return &iter->pg->records[iter->index]; | |
2825 | } | |
2826 | ||
492a7ea5 | 2827 | static int |
fbf6c73c | 2828 | ftrace_nop_initialize(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 | 2829 | { |
593eb8a2 | 2830 | int ret; |
3c1720f0 | 2831 | |
45a4a237 SR |
2832 | if (unlikely(ftrace_disabled)) |
2833 | return 0; | |
2834 | ||
fbf6c73c | 2835 | ret = ftrace_init_nop(mod, rec); |
593eb8a2 | 2836 | if (ret) { |
02a392a0 | 2837 | ftrace_bug_type = FTRACE_BUG_INIT; |
4fd3279b | 2838 | ftrace_bug(ret, rec); |
492a7ea5 | 2839 | return 0; |
37ad5084 | 2840 | } |
492a7ea5 | 2841 | return 1; |
3c1720f0 SR |
2842 | } |
2843 | ||
000ab691 SR |
2844 | /* |
2845 | * archs can override this function if they must do something | |
2846 | * before the modifying code is performed. | |
2847 | */ | |
3a2bfec0 | 2848 | void __weak ftrace_arch_code_modify_prepare(void) |
000ab691 | 2849 | { |
000ab691 SR |
2850 | } |
2851 | ||
2852 | /* | |
2853 | * archs can override this function if they must do something | |
2854 | * after the modifying code is performed. | |
2855 | */ | |
3a2bfec0 | 2856 | void __weak ftrace_arch_code_modify_post_process(void) |
000ab691 | 2857 | { |
000ab691 SR |
2858 | } |
2859 | ||
bd604f3d SRG |
2860 | static int update_ftrace_func(ftrace_func_t func) |
2861 | { | |
2862 | static ftrace_func_t save_func; | |
2863 | ||
2864 | /* Avoid updating if it hasn't changed */ | |
2865 | if (func == save_func) | |
2866 | return 0; | |
2867 | ||
2868 | save_func = func; | |
2869 | ||
2870 | return ftrace_update_ftrace_func(func); | |
2871 | } | |
2872 | ||
8ed3e2cf | 2873 | void ftrace_modify_all_code(int command) |
3d083395 | 2874 | { |
59338f75 | 2875 | int update = command & FTRACE_UPDATE_TRACE_FUNC; |
a0572f68 | 2876 | int mod_flags = 0; |
cd21067f | 2877 | int err = 0; |
59338f75 | 2878 | |
a0572f68 SRV |
2879 | if (command & FTRACE_MAY_SLEEP) |
2880 | mod_flags = FTRACE_MODIFY_MAY_SLEEP_FL; | |
2881 | ||
59338f75 SRRH |
2882 | /* |
2883 | * If the ftrace_caller calls a ftrace_ops func directly, | |
2884 | * we need to make sure that it only traces functions it | |
2885 | * expects to trace. When doing the switch of functions, | |
2886 | * we need to update to the ftrace_ops_list_func first | |
2887 | * before the transition between old and new calls are set, | |
2888 | * as the ftrace_ops_list_func will check the ops hashes | |
2889 | * to make sure the ops are having the right functions | |
2890 | * traced. | |
2891 | */ | |
cd21067f | 2892 | if (update) { |
bd604f3d | 2893 | err = update_ftrace_func(ftrace_ops_list_func); |
cd21067f PM |
2894 | if (FTRACE_WARN_ON(err)) |
2895 | return; | |
2896 | } | |
59338f75 | 2897 | |
8ed3e2cf | 2898 | if (command & FTRACE_UPDATE_CALLS) |
a0572f68 | 2899 | ftrace_replace_code(mod_flags | FTRACE_MODIFY_ENABLE_FL); |
8ed3e2cf | 2900 | else if (command & FTRACE_DISABLE_CALLS) |
a0572f68 | 2901 | ftrace_replace_code(mod_flags); |
d61f82d0 | 2902 | |
405e1d83 SRRH |
2903 | if (update && ftrace_trace_function != ftrace_ops_list_func) { |
2904 | function_trace_op = set_function_trace_op; | |
2905 | smp_wmb(); | |
2906 | /* If irqs are disabled, we are in stop machine */ | |
2907 | if (!irqs_disabled()) | |
2908 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
bd604f3d | 2909 | err = update_ftrace_func(ftrace_trace_function); |
cd21067f PM |
2910 | if (FTRACE_WARN_ON(err)) |
2911 | return; | |
405e1d83 | 2912 | } |
d61f82d0 | 2913 | |
8ed3e2cf | 2914 | if (command & FTRACE_START_FUNC_RET) |
cd21067f | 2915 | err = ftrace_enable_ftrace_graph_caller(); |
8ed3e2cf | 2916 | else if (command & FTRACE_STOP_FUNC_RET) |
cd21067f PM |
2917 | err = ftrace_disable_ftrace_graph_caller(); |
2918 | FTRACE_WARN_ON(err); | |
8ed3e2cf SR |
2919 | } |
2920 | ||
2921 | static int __ftrace_modify_code(void *data) | |
2922 | { | |
2923 | int *command = data; | |
2924 | ||
2925 | ftrace_modify_all_code(*command); | |
5a45cfe1 | 2926 | |
d61f82d0 | 2927 | return 0; |
3d083395 SR |
2928 | } |
2929 | ||
c88fd863 | 2930 | /** |
6130722f | 2931 | * ftrace_run_stop_machine - go back to the stop machine method |
c88fd863 SR |
2932 | * @command: The command to tell ftrace what to do |
2933 | * | |
2934 | * If an arch needs to fall back to the stop machine method, the | |
2935 | * it can call this function. | |
2936 | */ | |
2937 | void ftrace_run_stop_machine(int command) | |
2938 | { | |
2939 | stop_machine(__ftrace_modify_code, &command, NULL); | |
2940 | } | |
2941 | ||
2942 | /** | |
6130722f | 2943 | * arch_ftrace_update_code - modify the code to trace or not trace |
c88fd863 SR |
2944 | * @command: The command that needs to be done |
2945 | * | |
2946 | * Archs can override this function if it does not need to | |
2947 | * run stop_machine() to modify code. | |
2948 | */ | |
2949 | void __weak arch_ftrace_update_code(int command) | |
2950 | { | |
2951 | ftrace_run_stop_machine(command); | |
2952 | } | |
2953 | ||
e309b41d | 2954 | static void ftrace_run_update_code(int command) |
3d083395 | 2955 | { |
3a2bfec0 | 2956 | ftrace_arch_code_modify_prepare(); |
000ab691 | 2957 | |
c88fd863 SR |
2958 | /* |
2959 | * By default we use stop_machine() to modify the code. | |
2960 | * But archs can do what ever they want as long as it | |
2961 | * is safe. The stop_machine() is the safest, but also | |
2962 | * produces the most overhead. | |
2963 | */ | |
2964 | arch_ftrace_update_code(command); | |
2965 | ||
3a2bfec0 | 2966 | ftrace_arch_code_modify_post_process(); |
3d083395 SR |
2967 | } |
2968 | ||
8252ecf3 | 2969 | static void ftrace_run_modify_code(struct ftrace_ops *ops, int command, |
7485058e | 2970 | struct ftrace_ops_hash *old_hash) |
e1effa01 SRRH |
2971 | { |
2972 | ops->flags |= FTRACE_OPS_FL_MODIFYING; | |
7485058e SRRH |
2973 | ops->old_hash.filter_hash = old_hash->filter_hash; |
2974 | ops->old_hash.notrace_hash = old_hash->notrace_hash; | |
e1effa01 | 2975 | ftrace_run_update_code(command); |
8252ecf3 | 2976 | ops->old_hash.filter_hash = NULL; |
7485058e | 2977 | ops->old_hash.notrace_hash = NULL; |
e1effa01 SRRH |
2978 | ops->flags &= ~FTRACE_OPS_FL_MODIFYING; |
2979 | } | |
2980 | ||
d61f82d0 | 2981 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 2982 | static int ftrace_start_up; |
df4fc315 | 2983 | |
12cce594 SRRH |
2984 | void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops) |
2985 | { | |
2986 | } | |
2987 | ||
fc0ea795 AH |
2988 | /* List of trace_ops that have allocated trampolines */ |
2989 | static LIST_HEAD(ftrace_ops_trampoline_list); | |
2990 | ||
2991 | static void ftrace_add_trampoline_to_kallsyms(struct ftrace_ops *ops) | |
2992 | { | |
2993 | lockdep_assert_held(&ftrace_lock); | |
2994 | list_add_rcu(&ops->list, &ftrace_ops_trampoline_list); | |
2995 | } | |
2996 | ||
2997 | static void ftrace_remove_trampoline_from_kallsyms(struct ftrace_ops *ops) | |
2998 | { | |
2999 | lockdep_assert_held(&ftrace_lock); | |
3000 | list_del_rcu(&ops->list); | |
478ece95 | 3001 | synchronize_rcu(); |
fc0ea795 AH |
3002 | } |
3003 | ||
3004 | /* | |
3005 | * "__builtin__ftrace" is used as a module name in /proc/kallsyms for symbols | |
3006 | * for pages allocated for ftrace purposes, even though "__builtin__ftrace" is | |
3007 | * not a module. | |
3008 | */ | |
3009 | #define FTRACE_TRAMPOLINE_MOD "__builtin__ftrace" | |
3010 | #define FTRACE_TRAMPOLINE_SYM "ftrace_trampoline" | |
3011 | ||
3012 | static void ftrace_trampoline_free(struct ftrace_ops *ops) | |
3013 | { | |
3014 | if (ops && (ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP) && | |
dd9ddf46 | 3015 | ops->trampoline) { |
548e1f6c AH |
3016 | /* |
3017 | * Record the text poke event before the ksymbol unregister | |
3018 | * event. | |
3019 | */ | |
3020 | perf_event_text_poke((void *)ops->trampoline, | |
3021 | (void *)ops->trampoline, | |
3022 | ops->trampoline_size, NULL, 0); | |
dd9ddf46 AH |
3023 | perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL, |
3024 | ops->trampoline, ops->trampoline_size, | |
3025 | true, FTRACE_TRAMPOLINE_SYM); | |
3026 | /* Remove from kallsyms after the perf events */ | |
fc0ea795 | 3027 | ftrace_remove_trampoline_from_kallsyms(ops); |
dd9ddf46 | 3028 | } |
fc0ea795 AH |
3029 | |
3030 | arch_ftrace_trampoline_free(ops); | |
3031 | } | |
3032 | ||
df4fc315 SR |
3033 | static void ftrace_startup_enable(int command) |
3034 | { | |
3035 | if (saved_ftrace_func != ftrace_trace_function) { | |
3036 | saved_ftrace_func = ftrace_trace_function; | |
3037 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
3038 | } | |
3039 | ||
3040 | if (!command || !ftrace_enabled) | |
3041 | return; | |
3042 | ||
3043 | ftrace_run_update_code(command); | |
3044 | } | |
d61f82d0 | 3045 | |
e1effa01 SRRH |
3046 | static void ftrace_startup_all(int command) |
3047 | { | |
3048 | update_all_ops = true; | |
3049 | ftrace_startup_enable(command); | |
3050 | update_all_ops = false; | |
3051 | } | |
3052 | ||
3306fc4a | 3053 | int ftrace_startup(struct ftrace_ops *ops, int command) |
3d083395 | 3054 | { |
8a56d776 | 3055 | int ret; |
b848914c | 3056 | |
4eebcc81 | 3057 | if (unlikely(ftrace_disabled)) |
a1cd6173 | 3058 | return -ENODEV; |
4eebcc81 | 3059 | |
8a56d776 SRRH |
3060 | ret = __register_ftrace_function(ops); |
3061 | if (ret) | |
3062 | return ret; | |
3063 | ||
60a7ecf4 | 3064 | ftrace_start_up++; |
d61f82d0 | 3065 | |
e1effa01 SRRH |
3066 | /* |
3067 | * Note that ftrace probes uses this to start up | |
3068 | * and modify functions it will probe. But we still | |
3069 | * set the ADDING flag for modification, as probes | |
3070 | * do not have trampolines. If they add them in the | |
3071 | * future, then the probes will need to distinguish | |
3072 | * between adding and updating probes. | |
3073 | */ | |
3074 | ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING; | |
66209a5b | 3075 | |
f8b8be8a MH |
3076 | ret = ftrace_hash_ipmodify_enable(ops); |
3077 | if (ret < 0) { | |
3078 | /* Rollback registration process */ | |
3079 | __unregister_ftrace_function(ops); | |
3080 | ftrace_start_up--; | |
3081 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; | |
d5e47505 MB |
3082 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC) |
3083 | ftrace_trampoline_free(ops); | |
f8b8be8a MH |
3084 | return ret; |
3085 | } | |
3086 | ||
7f50d06b JO |
3087 | if (ftrace_hash_rec_enable(ops, 1)) |
3088 | command |= FTRACE_UPDATE_CALLS; | |
ed926f9b | 3089 | |
df4fc315 | 3090 | ftrace_startup_enable(command); |
a1cd6173 | 3091 | |
c3b0f72e YJ |
3092 | /* |
3093 | * If ftrace is in an undefined state, we just remove ops from list | |
3094 | * to prevent the NULL pointer, instead of totally rolling it back and | |
3095 | * free trampoline, because those actions could cause further damage. | |
3096 | */ | |
3097 | if (unlikely(ftrace_disabled)) { | |
3098 | __unregister_ftrace_function(ops); | |
3099 | return -ENODEV; | |
3100 | } | |
3101 | ||
e1effa01 SRRH |
3102 | ops->flags &= ~FTRACE_OPS_FL_ADDING; |
3103 | ||
a1cd6173 | 3104 | return 0; |
3d083395 SR |
3105 | } |
3106 | ||
3306fc4a | 3107 | int ftrace_shutdown(struct ftrace_ops *ops, int command) |
3d083395 | 3108 | { |
8a56d776 | 3109 | int ret; |
b848914c | 3110 | |
4eebcc81 | 3111 | if (unlikely(ftrace_disabled)) |
8a56d776 SRRH |
3112 | return -ENODEV; |
3113 | ||
3114 | ret = __unregister_ftrace_function(ops); | |
3115 | if (ret) | |
3116 | return ret; | |
4eebcc81 | 3117 | |
60a7ecf4 | 3118 | ftrace_start_up--; |
9ea1a153 FW |
3119 | /* |
3120 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
3121 | * critical but the ftrace_call callers may be never nopped again after | |
3122 | * further ftrace uses. | |
3123 | */ | |
3124 | WARN_ON_ONCE(ftrace_start_up < 0); | |
3125 | ||
f8b8be8a MH |
3126 | /* Disabling ipmodify never fails */ |
3127 | ftrace_hash_ipmodify_disable(ops); | |
ed926f9b | 3128 | |
7f50d06b JO |
3129 | if (ftrace_hash_rec_disable(ops, 1)) |
3130 | command |= FTRACE_UPDATE_CALLS; | |
b848914c | 3131 | |
7f50d06b | 3132 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
3d083395 | 3133 | |
d61f82d0 SR |
3134 | if (saved_ftrace_func != ftrace_trace_function) { |
3135 | saved_ftrace_func = ftrace_trace_function; | |
3136 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
3137 | } | |
3d083395 | 3138 | |
0e792b89 LH |
3139 | if (!command || !ftrace_enabled) |
3140 | goto out; | |
d61f82d0 | 3141 | |
79922b80 SRRH |
3142 | /* |
3143 | * If the ops uses a trampoline, then it needs to be | |
3144 | * tested first on update. | |
3145 | */ | |
e1effa01 | 3146 | ops->flags |= FTRACE_OPS_FL_REMOVING; |
79922b80 SRRH |
3147 | removed_ops = ops; |
3148 | ||
fef5aeee SRRH |
3149 | /* The trampoline logic checks the old hashes */ |
3150 | ops->old_hash.filter_hash = ops->func_hash->filter_hash; | |
3151 | ops->old_hash.notrace_hash = ops->func_hash->notrace_hash; | |
3152 | ||
d61f82d0 | 3153 | ftrace_run_update_code(command); |
a4c35ed2 | 3154 | |
84bde62c SRRH |
3155 | /* |
3156 | * If there's no more ops registered with ftrace, run a | |
3157 | * sanity check to make sure all rec flags are cleared. | |
3158 | */ | |
f86f4180 CZ |
3159 | if (rcu_dereference_protected(ftrace_ops_list, |
3160 | lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { | |
84bde62c SRRH |
3161 | struct ftrace_page *pg; |
3162 | struct dyn_ftrace *rec; | |
3163 | ||
3164 | do_for_each_ftrace_rec(pg, rec) { | |
977c1f9c | 3165 | if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_FL_DISABLED)) |
84bde62c SRRH |
3166 | pr_warn(" %pS flags:%lx\n", |
3167 | (void *)rec->ip, rec->flags); | |
3168 | } while_for_each_ftrace_rec(); | |
3169 | } | |
3170 | ||
fef5aeee SRRH |
3171 | ops->old_hash.filter_hash = NULL; |
3172 | ops->old_hash.notrace_hash = NULL; | |
3173 | ||
3174 | removed_ops = NULL; | |
e1effa01 | 3175 | ops->flags &= ~FTRACE_OPS_FL_REMOVING; |
79922b80 | 3176 | |
0e792b89 | 3177 | out: |
a4c35ed2 SRRH |
3178 | /* |
3179 | * Dynamic ops may be freed, we must make sure that all | |
3180 | * callers are done before leaving this function. | |
a4c35ed2 | 3181 | */ |
b3a88803 | 3182 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC) { |
0598e4f0 SRV |
3183 | /* |
3184 | * We need to do a hard force of sched synchronization. | |
3185 | * This is because we use preempt_disable() to do RCU, but | |
3186 | * the function tracers can be called where RCU is not watching | |
3187 | * (like before user_exit()). We can not rely on the RCU | |
3188 | * infrastructure to do the synchronization, thus we must do it | |
3189 | * ourselves. | |
3190 | */ | |
e5a971d7 | 3191 | synchronize_rcu_tasks_rude(); |
a4c35ed2 | 3192 | |
0598e4f0 | 3193 | /* |
fdda88d3 | 3194 | * When the kernel is preemptive, tasks can be preempted |
0598e4f0 SRV |
3195 | * while on a ftrace trampoline. Just scheduling a task on |
3196 | * a CPU is not good enough to flush them. Calling | |
f2cc020d | 3197 | * synchronize_rcu_tasks() will wait for those tasks to |
0598e4f0 SRV |
3198 | * execute and either schedule voluntarily or enter user space. |
3199 | */ | |
30c93704 | 3200 | if (IS_ENABLED(CONFIG_PREEMPTION)) |
0598e4f0 SRV |
3201 | synchronize_rcu_tasks(); |
3202 | ||
fc0ea795 | 3203 | ftrace_trampoline_free(ops); |
a4c35ed2 SRRH |
3204 | } |
3205 | ||
8a56d776 | 3206 | return 0; |
3d083395 SR |
3207 | } |
3208 | ||
a5a1d1c2 | 3209 | static u64 ftrace_update_time; |
3d083395 | 3210 | unsigned long ftrace_update_tot_cnt; |
da537f0a SRV |
3211 | unsigned long ftrace_number_of_pages; |
3212 | unsigned long ftrace_number_of_groups; | |
3d083395 | 3213 | |
8c4f3c3f | 3214 | static inline int ops_traces_mod(struct ftrace_ops *ops) |
f7bc8b61 | 3215 | { |
8c4f3c3f SRRH |
3216 | /* |
3217 | * Filter_hash being empty will default to trace module. | |
3218 | * But notrace hash requires a test of individual module functions. | |
3219 | */ | |
33b7f99c SRRH |
3220 | return ftrace_hash_empty(ops->func_hash->filter_hash) && |
3221 | ftrace_hash_empty(ops->func_hash->notrace_hash); | |
8c4f3c3f SRRH |
3222 | } |
3223 | ||
1dc43cf0 | 3224 | static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs) |
3d083395 | 3225 | { |
67ccddf8 | 3226 | bool init_nop = ftrace_need_init_nop(); |
85ae32ae | 3227 | struct ftrace_page *pg; |
e94142a6 | 3228 | struct dyn_ftrace *p; |
a5a1d1c2 | 3229 | u64 start, stop; |
1dc43cf0 | 3230 | unsigned long update_cnt = 0; |
b7ffffbb | 3231 | unsigned long rec_flags = 0; |
85ae32ae | 3232 | int i; |
f7bc8b61 | 3233 | |
b7ffffbb SRRH |
3234 | start = ftrace_now(raw_smp_processor_id()); |
3235 | ||
f7bc8b61 | 3236 | /* |
b7ffffbb SRRH |
3237 | * When a module is loaded, this function is called to convert |
3238 | * the calls to mcount in its text to nops, and also to create | |
3239 | * an entry in the ftrace data. Now, if ftrace is activated | |
3240 | * after this call, but before the module sets its text to | |
3241 | * read-only, the modification of enabling ftrace can fail if | |
3242 | * the read-only is done while ftrace is converting the calls. | |
3243 | * To prevent this, the module's records are set as disabled | |
3244 | * and will be enabled after the call to set the module's text | |
3245 | * to read-only. | |
f7bc8b61 | 3246 | */ |
b7ffffbb SRRH |
3247 | if (mod) |
3248 | rec_flags |= FTRACE_FL_DISABLED; | |
3d083395 | 3249 | |
1dc43cf0 | 3250 | for (pg = new_pgs; pg; pg = pg->next) { |
3d083395 | 3251 | |
85ae32ae | 3252 | for (i = 0; i < pg->index; i++) { |
8c4f3c3f | 3253 | |
85ae32ae SR |
3254 | /* If something went wrong, bail without enabling anything */ |
3255 | if (unlikely(ftrace_disabled)) | |
3256 | return -1; | |
f22f9a89 | 3257 | |
85ae32ae | 3258 | p = &pg->records[i]; |
b7ffffbb | 3259 | p->flags = rec_flags; |
f22f9a89 | 3260 | |
85ae32ae SR |
3261 | /* |
3262 | * Do the initial record conversion from mcount jump | |
3263 | * to the NOP instructions. | |
3264 | */ | |
67ccddf8 | 3265 | if (init_nop && !ftrace_nop_initialize(mod, p)) |
85ae32ae | 3266 | break; |
5cb084bb | 3267 | |
1dc43cf0 | 3268 | update_cnt++; |
5cb084bb | 3269 | } |
3d083395 SR |
3270 | } |
3271 | ||
750ed1a4 | 3272 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 | 3273 | ftrace_update_time = stop - start; |
1dc43cf0 | 3274 | ftrace_update_tot_cnt += update_cnt; |
3d083395 | 3275 | |
16444a8a ACM |
3276 | return 0; |
3277 | } | |
3278 | ||
a7900875 | 3279 | static int ftrace_allocate_records(struct ftrace_page *pg, int count) |
3c1720f0 | 3280 | { |
a7900875 | 3281 | int order; |
7ba031e8 | 3282 | int pages; |
3c1720f0 | 3283 | int cnt; |
3c1720f0 | 3284 | |
a7900875 SR |
3285 | if (WARN_ON(!count)) |
3286 | return -EINVAL; | |
3287 | ||
ceaaa129 | 3288 | /* We want to fill as much as possible, with no empty pages */ |
b40c6eab | 3289 | pages = DIV_ROUND_UP(count, ENTRIES_PER_PAGE); |
ceaaa129 | 3290 | order = fls(pages) - 1; |
3c1720f0 | 3291 | |
a7900875 SR |
3292 | again: |
3293 | pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order); | |
3c1720f0 | 3294 | |
a7900875 SR |
3295 | if (!pg->records) { |
3296 | /* if we can't allocate this size, try something smaller */ | |
3297 | if (!order) | |
3298 | return -ENOMEM; | |
bcea02b0 | 3299 | order--; |
a7900875 SR |
3300 | goto again; |
3301 | } | |
3c1720f0 | 3302 | |
da537f0a SRV |
3303 | ftrace_number_of_pages += 1 << order; |
3304 | ftrace_number_of_groups++; | |
3305 | ||
a7900875 | 3306 | cnt = (PAGE_SIZE << order) / ENTRY_SIZE; |
db42523b | 3307 | pg->order = order; |
3c1720f0 | 3308 | |
a7900875 SR |
3309 | if (cnt > count) |
3310 | cnt = count; | |
3311 | ||
3312 | return cnt; | |
3313 | } | |
3314 | ||
3315 | static struct ftrace_page * | |
3316 | ftrace_allocate_pages(unsigned long num_to_init) | |
3317 | { | |
3318 | struct ftrace_page *start_pg; | |
3319 | struct ftrace_page *pg; | |
a7900875 SR |
3320 | int cnt; |
3321 | ||
3322 | if (!num_to_init) | |
9efb85c5 | 3323 | return NULL; |
a7900875 SR |
3324 | |
3325 | start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL); | |
3326 | if (!pg) | |
3327 | return NULL; | |
3328 | ||
3329 | /* | |
3330 | * Try to allocate as much as possible in one continues | |
3331 | * location that fills in all of the space. We want to | |
3332 | * waste as little space as possible. | |
3333 | */ | |
3334 | for (;;) { | |
3335 | cnt = ftrace_allocate_records(pg, num_to_init); | |
3336 | if (cnt < 0) | |
3337 | goto free_pages; | |
3338 | ||
3339 | num_to_init -= cnt; | |
3340 | if (!num_to_init) | |
3c1720f0 SR |
3341 | break; |
3342 | ||
a7900875 SR |
3343 | pg->next = kzalloc(sizeof(*pg), GFP_KERNEL); |
3344 | if (!pg->next) | |
3345 | goto free_pages; | |
3346 | ||
3c1720f0 SR |
3347 | pg = pg->next; |
3348 | } | |
3349 | ||
a7900875 SR |
3350 | return start_pg; |
3351 | ||
3352 | free_pages: | |
1f61be00 NK |
3353 | pg = start_pg; |
3354 | while (pg) { | |
db42523b LT |
3355 | if (pg->records) { |
3356 | free_pages((unsigned long)pg->records, pg->order); | |
3357 | ftrace_number_of_pages -= 1 << pg->order; | |
3358 | } | |
a7900875 SR |
3359 | start_pg = pg->next; |
3360 | kfree(pg); | |
3361 | pg = start_pg; | |
da537f0a | 3362 | ftrace_number_of_groups--; |
a7900875 SR |
3363 | } |
3364 | pr_info("ftrace: FAILED to allocate memory for functions\n"); | |
3365 | return NULL; | |
3366 | } | |
3367 | ||
5072c59f SR |
3368 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ |
3369 | ||
3370 | struct ftrace_iterator { | |
98c4fd04 | 3371 | loff_t pos; |
4aeb6967 | 3372 | loff_t func_pos; |
5985ea8b | 3373 | loff_t mod_pos; |
4aeb6967 SR |
3374 | struct ftrace_page *pg; |
3375 | struct dyn_ftrace *func; | |
3376 | struct ftrace_func_probe *probe; | |
eee8ded1 | 3377 | struct ftrace_func_entry *probe_entry; |
4aeb6967 | 3378 | struct trace_parser parser; |
1cf41dd7 | 3379 | struct ftrace_hash *hash; |
33dc9b12 | 3380 | struct ftrace_ops *ops; |
5985ea8b SRV |
3381 | struct trace_array *tr; |
3382 | struct list_head *mod_list; | |
eee8ded1 | 3383 | int pidx; |
4aeb6967 SR |
3384 | int idx; |
3385 | unsigned flags; | |
5072c59f SR |
3386 | }; |
3387 | ||
8fc0c701 | 3388 | static void * |
eee8ded1 | 3389 | t_probe_next(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
3390 | { |
3391 | struct ftrace_iterator *iter = m->private; | |
d2afd57a | 3392 | struct trace_array *tr = iter->ops->private; |
04ec7bb6 | 3393 | struct list_head *func_probes; |
eee8ded1 SRV |
3394 | struct ftrace_hash *hash; |
3395 | struct list_head *next; | |
4aeb6967 | 3396 | struct hlist_node *hnd = NULL; |
8fc0c701 | 3397 | struct hlist_head *hhd; |
eee8ded1 | 3398 | int size; |
8fc0c701 | 3399 | |
8fc0c701 | 3400 | (*pos)++; |
98c4fd04 | 3401 | iter->pos = *pos; |
8fc0c701 | 3402 | |
04ec7bb6 | 3403 | if (!tr) |
8fc0c701 SR |
3404 | return NULL; |
3405 | ||
04ec7bb6 SRV |
3406 | func_probes = &tr->func_probes; |
3407 | if (list_empty(func_probes)) | |
8fc0c701 SR |
3408 | return NULL; |
3409 | ||
eee8ded1 | 3410 | if (!iter->probe) { |
04ec7bb6 | 3411 | next = func_probes->next; |
7b60f3d8 | 3412 | iter->probe = list_entry(next, struct ftrace_func_probe, list); |
eee8ded1 SRV |
3413 | } |
3414 | ||
3415 | if (iter->probe_entry) | |
3416 | hnd = &iter->probe_entry->hlist; | |
3417 | ||
3418 | hash = iter->probe->ops.func_hash->filter_hash; | |
7bd46644 | 3419 | |
372e0d01 SRV |
3420 | /* |
3421 | * A probe being registered may temporarily have an empty hash | |
3422 | * and it's at the end of the func_probes list. | |
3423 | */ | |
3424 | if (!hash || hash == EMPTY_HASH) | |
7bd46644 NR |
3425 | return NULL; |
3426 | ||
eee8ded1 SRV |
3427 | size = 1 << hash->size_bits; |
3428 | ||
3429 | retry: | |
3430 | if (iter->pidx >= size) { | |
04ec7bb6 | 3431 | if (iter->probe->list.next == func_probes) |
eee8ded1 SRV |
3432 | return NULL; |
3433 | next = iter->probe->list.next; | |
7b60f3d8 | 3434 | iter->probe = list_entry(next, struct ftrace_func_probe, list); |
eee8ded1 SRV |
3435 | hash = iter->probe->ops.func_hash->filter_hash; |
3436 | size = 1 << hash->size_bits; | |
3437 | iter->pidx = 0; | |
3438 | } | |
3439 | ||
3440 | hhd = &hash->buckets[iter->pidx]; | |
8fc0c701 SR |
3441 | |
3442 | if (hlist_empty(hhd)) { | |
eee8ded1 | 3443 | iter->pidx++; |
8fc0c701 SR |
3444 | hnd = NULL; |
3445 | goto retry; | |
3446 | } | |
3447 | ||
3448 | if (!hnd) | |
3449 | hnd = hhd->first; | |
3450 | else { | |
3451 | hnd = hnd->next; | |
3452 | if (!hnd) { | |
eee8ded1 | 3453 | iter->pidx++; |
8fc0c701 SR |
3454 | goto retry; |
3455 | } | |
3456 | } | |
3457 | ||
4aeb6967 SR |
3458 | if (WARN_ON_ONCE(!hnd)) |
3459 | return NULL; | |
3460 | ||
eee8ded1 | 3461 | iter->probe_entry = hlist_entry(hnd, struct ftrace_func_entry, hlist); |
4aeb6967 SR |
3462 | |
3463 | return iter; | |
8fc0c701 SR |
3464 | } |
3465 | ||
eee8ded1 | 3466 | static void *t_probe_start(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
3467 | { |
3468 | struct ftrace_iterator *iter = m->private; | |
3469 | void *p = NULL; | |
d82d6244 LZ |
3470 | loff_t l; |
3471 | ||
eee8ded1 | 3472 | if (!(iter->flags & FTRACE_ITER_DO_PROBES)) |
69a3083c SR |
3473 | return NULL; |
3474 | ||
5985ea8b | 3475 | if (iter->mod_pos > *pos) |
2bccfffd | 3476 | return NULL; |
8fc0c701 | 3477 | |
eee8ded1 SRV |
3478 | iter->probe = NULL; |
3479 | iter->probe_entry = NULL; | |
3480 | iter->pidx = 0; | |
5985ea8b | 3481 | for (l = 0; l <= (*pos - iter->mod_pos); ) { |
eee8ded1 | 3482 | p = t_probe_next(m, &l); |
d82d6244 LZ |
3483 | if (!p) |
3484 | break; | |
3485 | } | |
4aeb6967 SR |
3486 | if (!p) |
3487 | return NULL; | |
3488 | ||
98c4fd04 | 3489 | /* Only set this if we have an item */ |
eee8ded1 | 3490 | iter->flags |= FTRACE_ITER_PROBE; |
98c4fd04 | 3491 | |
4aeb6967 | 3492 | return iter; |
8fc0c701 SR |
3493 | } |
3494 | ||
4aeb6967 | 3495 | static int |
eee8ded1 | 3496 | t_probe_show(struct seq_file *m, struct ftrace_iterator *iter) |
8fc0c701 | 3497 | { |
eee8ded1 | 3498 | struct ftrace_func_entry *probe_entry; |
7b60f3d8 SRV |
3499 | struct ftrace_probe_ops *probe_ops; |
3500 | struct ftrace_func_probe *probe; | |
8fc0c701 | 3501 | |
eee8ded1 SRV |
3502 | probe = iter->probe; |
3503 | probe_entry = iter->probe_entry; | |
8fc0c701 | 3504 | |
eee8ded1 | 3505 | if (WARN_ON_ONCE(!probe || !probe_entry)) |
4aeb6967 | 3506 | return -EIO; |
8fc0c701 | 3507 | |
7b60f3d8 | 3508 | probe_ops = probe->probe_ops; |
809dcf29 | 3509 | |
7b60f3d8 | 3510 | if (probe_ops->print) |
6e444319 | 3511 | return probe_ops->print(m, probe_entry->ip, probe_ops, probe->data); |
8fc0c701 | 3512 | |
7b60f3d8 SRV |
3513 | seq_printf(m, "%ps:%ps\n", (void *)probe_entry->ip, |
3514 | (void *)probe_ops->func); | |
8fc0c701 SR |
3515 | |
3516 | return 0; | |
3517 | } | |
3518 | ||
5985ea8b SRV |
3519 | static void * |
3520 | t_mod_next(struct seq_file *m, loff_t *pos) | |
3521 | { | |
3522 | struct ftrace_iterator *iter = m->private; | |
3523 | struct trace_array *tr = iter->tr; | |
3524 | ||
3525 | (*pos)++; | |
3526 | iter->pos = *pos; | |
3527 | ||
3528 | iter->mod_list = iter->mod_list->next; | |
3529 | ||
3530 | if (iter->mod_list == &tr->mod_trace || | |
3531 | iter->mod_list == &tr->mod_notrace) { | |
3532 | iter->flags &= ~FTRACE_ITER_MOD; | |
3533 | return NULL; | |
3534 | } | |
3535 | ||
3536 | iter->mod_pos = *pos; | |
3537 | ||
3538 | return iter; | |
3539 | } | |
3540 | ||
3541 | static void *t_mod_start(struct seq_file *m, loff_t *pos) | |
3542 | { | |
3543 | struct ftrace_iterator *iter = m->private; | |
3544 | void *p = NULL; | |
3545 | loff_t l; | |
3546 | ||
3547 | if (iter->func_pos > *pos) | |
3548 | return NULL; | |
3549 | ||
3550 | iter->mod_pos = iter->func_pos; | |
3551 | ||
3552 | /* probes are only available if tr is set */ | |
3553 | if (!iter->tr) | |
3554 | return NULL; | |
3555 | ||
3556 | for (l = 0; l <= (*pos - iter->func_pos); ) { | |
3557 | p = t_mod_next(m, &l); | |
3558 | if (!p) | |
3559 | break; | |
3560 | } | |
3561 | if (!p) { | |
3562 | iter->flags &= ~FTRACE_ITER_MOD; | |
3563 | return t_probe_start(m, pos); | |
3564 | } | |
3565 | ||
3566 | /* Only set this if we have an item */ | |
3567 | iter->flags |= FTRACE_ITER_MOD; | |
3568 | ||
3569 | return iter; | |
3570 | } | |
3571 | ||
3572 | static int | |
3573 | t_mod_show(struct seq_file *m, struct ftrace_iterator *iter) | |
3574 | { | |
3575 | struct ftrace_mod_load *ftrace_mod; | |
3576 | struct trace_array *tr = iter->tr; | |
3577 | ||
3578 | if (WARN_ON_ONCE(!iter->mod_list) || | |
3579 | iter->mod_list == &tr->mod_trace || | |
3580 | iter->mod_list == &tr->mod_notrace) | |
3581 | return -EIO; | |
3582 | ||
3583 | ftrace_mod = list_entry(iter->mod_list, struct ftrace_mod_load, list); | |
3584 | ||
3585 | if (ftrace_mod->func) | |
3586 | seq_printf(m, "%s", ftrace_mod->func); | |
3587 | else | |
3588 | seq_putc(m, '*'); | |
3589 | ||
3590 | seq_printf(m, ":mod:%s\n", ftrace_mod->module); | |
3591 | ||
3592 | return 0; | |
3593 | } | |
3594 | ||
e309b41d | 3595 | static void * |
5bd84629 | 3596 | t_func_next(struct seq_file *m, loff_t *pos) |
5072c59f SR |
3597 | { |
3598 | struct ftrace_iterator *iter = m->private; | |
3599 | struct dyn_ftrace *rec = NULL; | |
3600 | ||
3601 | (*pos)++; | |
0c75a3ed | 3602 | |
5072c59f SR |
3603 | retry: |
3604 | if (iter->idx >= iter->pg->index) { | |
3605 | if (iter->pg->next) { | |
3606 | iter->pg = iter->pg->next; | |
3607 | iter->idx = 0; | |
3608 | goto retry; | |
3609 | } | |
3610 | } else { | |
3611 | rec = &iter->pg->records[iter->idx++]; | |
c20489da SRV |
3612 | if (((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) && |
3613 | !ftrace_lookup_ip(iter->hash, rec->ip)) || | |
647bcd03 SR |
3614 | |
3615 | ((iter->flags & FTRACE_ITER_ENABLED) && | |
23ea9c4d | 3616 | !(rec->flags & FTRACE_FL_ENABLED))) { |
647bcd03 | 3617 | |
5072c59f SR |
3618 | rec = NULL; |
3619 | goto retry; | |
3620 | } | |
3621 | } | |
3622 | ||
4aeb6967 | 3623 | if (!rec) |
5bd84629 | 3624 | return NULL; |
4aeb6967 | 3625 | |
5bd84629 | 3626 | iter->pos = iter->func_pos = *pos; |
4aeb6967 SR |
3627 | iter->func = rec; |
3628 | ||
3629 | return iter; | |
5072c59f SR |
3630 | } |
3631 | ||
5bd84629 SRV |
3632 | static void * |
3633 | t_next(struct seq_file *m, void *v, loff_t *pos) | |
3634 | { | |
3635 | struct ftrace_iterator *iter = m->private; | |
5985ea8b | 3636 | loff_t l = *pos; /* t_probe_start() must use original pos */ |
5bd84629 SRV |
3637 | void *ret; |
3638 | ||
3639 | if (unlikely(ftrace_disabled)) | |
3640 | return NULL; | |
3641 | ||
eee8ded1 SRV |
3642 | if (iter->flags & FTRACE_ITER_PROBE) |
3643 | return t_probe_next(m, pos); | |
5bd84629 | 3644 | |
5985ea8b SRV |
3645 | if (iter->flags & FTRACE_ITER_MOD) |
3646 | return t_mod_next(m, pos); | |
3647 | ||
5bd84629 | 3648 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
eee8ded1 | 3649 | /* next must increment pos, and t_probe_start does not */ |
5bd84629 | 3650 | (*pos)++; |
5985ea8b | 3651 | return t_mod_start(m, &l); |
5bd84629 SRV |
3652 | } |
3653 | ||
3654 | ret = t_func_next(m, pos); | |
3655 | ||
3656 | if (!ret) | |
5985ea8b | 3657 | return t_mod_start(m, &l); |
5bd84629 SRV |
3658 | |
3659 | return ret; | |
3660 | } | |
3661 | ||
98c4fd04 SR |
3662 | static void reset_iter_read(struct ftrace_iterator *iter) |
3663 | { | |
3664 | iter->pos = 0; | |
3665 | iter->func_pos = 0; | |
5985ea8b | 3666 | iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_PROBE | FTRACE_ITER_MOD); |
5072c59f SR |
3667 | } |
3668 | ||
3669 | static void *t_start(struct seq_file *m, loff_t *pos) | |
3670 | { | |
3671 | struct ftrace_iterator *iter = m->private; | |
3672 | void *p = NULL; | |
694ce0a5 | 3673 | loff_t l; |
5072c59f | 3674 | |
8fc0c701 | 3675 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
3676 | |
3677 | if (unlikely(ftrace_disabled)) | |
3678 | return NULL; | |
3679 | ||
98c4fd04 SR |
3680 | /* |
3681 | * If an lseek was done, then reset and start from beginning. | |
3682 | */ | |
3683 | if (*pos < iter->pos) | |
3684 | reset_iter_read(iter); | |
3685 | ||
0c75a3ed SR |
3686 | /* |
3687 | * For set_ftrace_filter reading, if we have the filter | |
3688 | * off, we can short cut and just print out that all | |
3689 | * functions are enabled. | |
3690 | */ | |
c20489da SRV |
3691 | if ((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) && |
3692 | ftrace_hash_empty(iter->hash)) { | |
43ff926a | 3693 | iter->func_pos = 1; /* Account for the message */ |
0c75a3ed | 3694 | if (*pos > 0) |
5985ea8b | 3695 | return t_mod_start(m, pos); |
0c75a3ed | 3696 | iter->flags |= FTRACE_ITER_PRINTALL; |
df091625 | 3697 | /* reset in case of seek/pread */ |
eee8ded1 | 3698 | iter->flags &= ~FTRACE_ITER_PROBE; |
0c75a3ed SR |
3699 | return iter; |
3700 | } | |
3701 | ||
5985ea8b SRV |
3702 | if (iter->flags & FTRACE_ITER_MOD) |
3703 | return t_mod_start(m, pos); | |
8fc0c701 | 3704 | |
98c4fd04 SR |
3705 | /* |
3706 | * Unfortunately, we need to restart at ftrace_pages_start | |
3707 | * every time we let go of the ftrace_mutex. This is because | |
3708 | * those pointers can change without the lock. | |
3709 | */ | |
694ce0a5 LZ |
3710 | iter->pg = ftrace_pages_start; |
3711 | iter->idx = 0; | |
3712 | for (l = 0; l <= *pos; ) { | |
5bd84629 | 3713 | p = t_func_next(m, &l); |
694ce0a5 LZ |
3714 | if (!p) |
3715 | break; | |
50cdaf08 | 3716 | } |
5821e1b7 | 3717 | |
69a3083c | 3718 | if (!p) |
5985ea8b | 3719 | return t_mod_start(m, pos); |
4aeb6967 SR |
3720 | |
3721 | return iter; | |
5072c59f SR |
3722 | } |
3723 | ||
3724 | static void t_stop(struct seq_file *m, void *p) | |
3725 | { | |
8fc0c701 | 3726 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
3727 | } |
3728 | ||
15d5b02c SRRH |
3729 | void * __weak |
3730 | arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec) | |
3731 | { | |
3732 | return NULL; | |
3733 | } | |
3734 | ||
3735 | static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops, | |
3736 | struct dyn_ftrace *rec) | |
3737 | { | |
3738 | void *ptr; | |
3739 | ||
3740 | ptr = arch_ftrace_trampoline_func(ops, rec); | |
3741 | if (ptr) | |
3742 | seq_printf(m, " ->%pS", ptr); | |
3743 | } | |
3744 | ||
b39181f7 SRG |
3745 | #ifdef FTRACE_MCOUNT_MAX_OFFSET |
3746 | /* | |
3747 | * Weak functions can still have an mcount/fentry that is saved in | |
3748 | * the __mcount_loc section. These can be detected by having a | |
3749 | * symbol offset of greater than FTRACE_MCOUNT_MAX_OFFSET, as the | |
3750 | * symbol found by kallsyms is not the function that the mcount/fentry | |
3751 | * is part of. The offset is much greater in these cases. | |
3752 | * | |
3753 | * Test the record to make sure that the ip points to a valid kallsyms | |
3754 | * and if not, mark it disabled. | |
3755 | */ | |
3756 | static int test_for_valid_rec(struct dyn_ftrace *rec) | |
3757 | { | |
3758 | char str[KSYM_SYMBOL_LEN]; | |
3759 | unsigned long offset; | |
3760 | const char *ret; | |
3761 | ||
3762 | ret = kallsyms_lookup(rec->ip, NULL, &offset, NULL, str); | |
3763 | ||
3764 | /* Weak functions can cause invalid addresses */ | |
3765 | if (!ret || offset > FTRACE_MCOUNT_MAX_OFFSET) { | |
3766 | rec->flags |= FTRACE_FL_DISABLED; | |
3767 | return 0; | |
3768 | } | |
3769 | return 1; | |
3770 | } | |
3771 | ||
3772 | static struct workqueue_struct *ftrace_check_wq __initdata; | |
3773 | static struct work_struct ftrace_check_work __initdata; | |
3774 | ||
3775 | /* | |
3776 | * Scan all the mcount/fentry entries to make sure they are valid. | |
3777 | */ | |
3778 | static __init void ftrace_check_work_func(struct work_struct *work) | |
3779 | { | |
3780 | struct ftrace_page *pg; | |
3781 | struct dyn_ftrace *rec; | |
3782 | ||
3783 | mutex_lock(&ftrace_lock); | |
3784 | do_for_each_ftrace_rec(pg, rec) { | |
3785 | test_for_valid_rec(rec); | |
3786 | } while_for_each_ftrace_rec(); | |
3787 | mutex_unlock(&ftrace_lock); | |
3788 | } | |
3789 | ||
3790 | static int __init ftrace_check_for_weak_functions(void) | |
3791 | { | |
3792 | INIT_WORK(&ftrace_check_work, ftrace_check_work_func); | |
3793 | ||
3794 | ftrace_check_wq = alloc_workqueue("ftrace_check_wq", WQ_UNBOUND, 0); | |
3795 | ||
3796 | queue_work(ftrace_check_wq, &ftrace_check_work); | |
3797 | return 0; | |
3798 | } | |
3799 | ||
3800 | static int __init ftrace_check_sync(void) | |
3801 | { | |
3802 | /* Make sure the ftrace_check updates are finished */ | |
3803 | if (ftrace_check_wq) | |
3804 | destroy_workqueue(ftrace_check_wq); | |
3805 | return 0; | |
3806 | } | |
3807 | ||
3808 | late_initcall_sync(ftrace_check_sync); | |
3809 | subsys_initcall(ftrace_check_for_weak_functions); | |
3810 | ||
3811 | static int print_rec(struct seq_file *m, unsigned long ip) | |
3812 | { | |
3813 | unsigned long offset; | |
3814 | char str[KSYM_SYMBOL_LEN]; | |
3815 | char *modname; | |
3816 | const char *ret; | |
3817 | ||
3818 | ret = kallsyms_lookup(ip, NULL, &offset, &modname, str); | |
3819 | /* Weak functions can cause invalid addresses */ | |
3820 | if (!ret || offset > FTRACE_MCOUNT_MAX_OFFSET) { | |
3821 | snprintf(str, KSYM_SYMBOL_LEN, "%s_%ld", | |
3822 | FTRACE_INVALID_FUNCTION, offset); | |
3823 | ret = NULL; | |
3824 | } | |
3825 | ||
3826 | seq_puts(m, str); | |
3827 | if (modname) | |
3828 | seq_printf(m, " [%s]", modname); | |
3829 | return ret == NULL ? -1 : 0; | |
3830 | } | |
3831 | #else | |
3832 | static inline int test_for_valid_rec(struct dyn_ftrace *rec) | |
3833 | { | |
3834 | return 1; | |
3835 | } | |
3836 | ||
3837 | static inline int print_rec(struct seq_file *m, unsigned long ip) | |
3838 | { | |
3839 | seq_printf(m, "%ps", (void *)ip); | |
3840 | return 0; | |
3841 | } | |
3842 | #endif | |
3843 | ||
5072c59f SR |
3844 | static int t_show(struct seq_file *m, void *v) |
3845 | { | |
0c75a3ed | 3846 | struct ftrace_iterator *iter = m->private; |
4aeb6967 | 3847 | struct dyn_ftrace *rec; |
5072c59f | 3848 | |
eee8ded1 SRV |
3849 | if (iter->flags & FTRACE_ITER_PROBE) |
3850 | return t_probe_show(m, iter); | |
8fc0c701 | 3851 | |
5985ea8b SRV |
3852 | if (iter->flags & FTRACE_ITER_MOD) |
3853 | return t_mod_show(m, iter); | |
3854 | ||
0c75a3ed | 3855 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
8c006cf7 | 3856 | if (iter->flags & FTRACE_ITER_NOTRACE) |
fa6f0cc7 | 3857 | seq_puts(m, "#### no functions disabled ####\n"); |
8c006cf7 | 3858 | else |
fa6f0cc7 | 3859 | seq_puts(m, "#### all functions enabled ####\n"); |
0c75a3ed SR |
3860 | return 0; |
3861 | } | |
3862 | ||
4aeb6967 SR |
3863 | rec = iter->func; |
3864 | ||
5072c59f SR |
3865 | if (!rec) |
3866 | return 0; | |
3867 | ||
b39181f7 SRG |
3868 | if (print_rec(m, rec->ip)) { |
3869 | /* This should only happen when a rec is disabled */ | |
3870 | WARN_ON_ONCE(!(rec->flags & FTRACE_FL_DISABLED)); | |
3871 | seq_putc(m, '\n'); | |
3872 | return 0; | |
3873 | } | |
3874 | ||
9674b2fa | 3875 | if (iter->flags & FTRACE_ITER_ENABLED) { |
030f4e1c | 3876 | struct ftrace_ops *ops; |
15d5b02c | 3877 | |
cbad0fb2 | 3878 | seq_printf(m, " (%ld)%s%s%s%s", |
0376bde1 | 3879 | ftrace_rec_count(rec), |
f8b8be8a | 3880 | rec->flags & FTRACE_FL_REGS ? " R" : " ", |
763e34e7 | 3881 | rec->flags & FTRACE_FL_IPMODIFY ? " I" : " ", |
cbad0fb2 MR |
3882 | rec->flags & FTRACE_FL_DIRECT ? " D" : " ", |
3883 | rec->flags & FTRACE_FL_CALL_OPS ? " O" : " "); | |
9674b2fa | 3884 | if (rec->flags & FTRACE_FL_TRAMP_EN) { |
5fecaa04 | 3885 | ops = ftrace_find_tramp_ops_any(rec); |
39daa7b9 SRRH |
3886 | if (ops) { |
3887 | do { | |
3888 | seq_printf(m, "\ttramp: %pS (%pS)", | |
3889 | (void *)ops->trampoline, | |
3890 | (void *)ops->func); | |
030f4e1c | 3891 | add_trampoline_func(m, ops, rec); |
39daa7b9 SRRH |
3892 | ops = ftrace_find_tramp_ops_next(rec, ops); |
3893 | } while (ops); | |
3894 | } else | |
fa6f0cc7 | 3895 | seq_puts(m, "\ttramp: ERROR!"); |
030f4e1c SRRH |
3896 | } else { |
3897 | add_trampoline_func(m, NULL, rec); | |
9674b2fa | 3898 | } |
cbad0fb2 MR |
3899 | if (rec->flags & FTRACE_FL_CALL_OPS_EN) { |
3900 | ops = ftrace_find_unique_ops(rec); | |
3901 | if (ops) { | |
3902 | seq_printf(m, "\tops: %pS (%pS)", | |
3903 | ops, ops->func); | |
3904 | } else { | |
3905 | seq_puts(m, "\tops: ERROR!"); | |
3906 | } | |
3907 | } | |
763e34e7 SRV |
3908 | if (rec->flags & FTRACE_FL_DIRECT) { |
3909 | unsigned long direct; | |
3910 | ||
ff205766 | 3911 | direct = ftrace_find_rec_direct(rec->ip); |
763e34e7 SRV |
3912 | if (direct) |
3913 | seq_printf(m, "\n\tdirect-->%pS", (void *)direct); | |
3914 | } | |
026bb845 | 3915 | } |
9674b2fa | 3916 | |
fa6f0cc7 | 3917 | seq_putc(m, '\n'); |
5072c59f SR |
3918 | |
3919 | return 0; | |
3920 | } | |
3921 | ||
88e9d34c | 3922 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
3923 | .start = t_start, |
3924 | .next = t_next, | |
3925 | .stop = t_stop, | |
3926 | .show = t_show, | |
3927 | }; | |
3928 | ||
e309b41d | 3929 | static int |
5072c59f SR |
3930 | ftrace_avail_open(struct inode *inode, struct file *file) |
3931 | { | |
3932 | struct ftrace_iterator *iter; | |
17911ff3 SRV |
3933 | int ret; |
3934 | ||
3935 | ret = security_locked_down(LOCKDOWN_TRACEFS); | |
3936 | if (ret) | |
3937 | return ret; | |
5072c59f | 3938 | |
4eebcc81 SR |
3939 | if (unlikely(ftrace_disabled)) |
3940 | return -ENODEV; | |
3941 | ||
50e18b94 | 3942 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
c1bc5919 SRV |
3943 | if (!iter) |
3944 | return -ENOMEM; | |
5072c59f | 3945 | |
c1bc5919 SRV |
3946 | iter->pg = ftrace_pages_start; |
3947 | iter->ops = &global_ops; | |
3948 | ||
3949 | return 0; | |
5072c59f SR |
3950 | } |
3951 | ||
647bcd03 SR |
3952 | static int |
3953 | ftrace_enabled_open(struct inode *inode, struct file *file) | |
3954 | { | |
3955 | struct ftrace_iterator *iter; | |
647bcd03 | 3956 | |
17911ff3 SRV |
3957 | /* |
3958 | * This shows us what functions are currently being | |
3959 | * traced and by what. Not sure if we want lockdown | |
3960 | * to hide such critical information for an admin. | |
3961 | * Although, perhaps it can show information we don't | |
3962 | * want people to see, but if something is tracing | |
3963 | * something, we probably want to know about it. | |
3964 | */ | |
3965 | ||
50e18b94 | 3966 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
c1bc5919 SRV |
3967 | if (!iter) |
3968 | return -ENOMEM; | |
647bcd03 | 3969 | |
c1bc5919 SRV |
3970 | iter->pg = ftrace_pages_start; |
3971 | iter->flags = FTRACE_ITER_ENABLED; | |
3972 | iter->ops = &global_ops; | |
3973 | ||
3974 | return 0; | |
647bcd03 SR |
3975 | } |
3976 | ||
fc13cb0c SR |
3977 | /** |
3978 | * ftrace_regex_open - initialize function tracer filter files | |
3979 | * @ops: The ftrace_ops that hold the hash filters | |
3980 | * @flag: The type of filter to process | |
3981 | * @inode: The inode, usually passed in to your open routine | |
3982 | * @file: The file, usually passed in to your open routine | |
3983 | * | |
3984 | * ftrace_regex_open() initializes the filter files for the | |
3985 | * @ops. Depending on @flag it may process the filter hash or | |
3986 | * the notrace hash of @ops. With this called from the open | |
3987 | * routine, you can use ftrace_filter_write() for the write | |
3988 | * routine if @flag has FTRACE_ITER_FILTER set, or | |
3989 | * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set. | |
098c879e | 3990 | * tracing_lseek() should be used as the lseek routine, and |
fc13cb0c SR |
3991 | * release must call ftrace_regex_release(). |
3992 | */ | |
3993 | int | |
f45948e8 | 3994 | ftrace_regex_open(struct ftrace_ops *ops, int flag, |
1cf41dd7 | 3995 | struct inode *inode, struct file *file) |
5072c59f SR |
3996 | { |
3997 | struct ftrace_iterator *iter; | |
f45948e8 | 3998 | struct ftrace_hash *hash; |
673feb9d SRV |
3999 | struct list_head *mod_head; |
4000 | struct trace_array *tr = ops->private; | |
9ef16693 | 4001 | int ret = -ENOMEM; |
5072c59f | 4002 | |
f04f24fb MH |
4003 | ftrace_ops_init(ops); |
4004 | ||
4eebcc81 SR |
4005 | if (unlikely(ftrace_disabled)) |
4006 | return -ENODEV; | |
4007 | ||
8530dec6 | 4008 | if (tracing_check_open_get_tr(tr)) |
9ef16693 SRV |
4009 | return -ENODEV; |
4010 | ||
5072c59f SR |
4011 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
4012 | if (!iter) | |
9ef16693 | 4013 | goto out; |
5072c59f | 4014 | |
9ef16693 SRV |
4015 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) |
4016 | goto out; | |
689fd8b6 | 4017 | |
3f2367ba MH |
4018 | iter->ops = ops; |
4019 | iter->flags = flag; | |
5985ea8b | 4020 | iter->tr = tr; |
3f2367ba | 4021 | |
33b7f99c | 4022 | mutex_lock(&ops->func_hash->regex_lock); |
3f2367ba | 4023 | |
673feb9d | 4024 | if (flag & FTRACE_ITER_NOTRACE) { |
33b7f99c | 4025 | hash = ops->func_hash->notrace_hash; |
5985ea8b | 4026 | mod_head = tr ? &tr->mod_notrace : NULL; |
673feb9d | 4027 | } else { |
33b7f99c | 4028 | hash = ops->func_hash->filter_hash; |
5985ea8b | 4029 | mod_head = tr ? &tr->mod_trace : NULL; |
673feb9d | 4030 | } |
f45948e8 | 4031 | |
5985ea8b SRV |
4032 | iter->mod_list = mod_head; |
4033 | ||
33dc9b12 | 4034 | if (file->f_mode & FMODE_WRITE) { |
ef2fbe16 NK |
4035 | const int size_bits = FTRACE_HASH_DEFAULT_BITS; |
4036 | ||
673feb9d | 4037 | if (file->f_flags & O_TRUNC) { |
ef2fbe16 | 4038 | iter->hash = alloc_ftrace_hash(size_bits); |
673feb9d SRV |
4039 | clear_ftrace_mod_list(mod_head); |
4040 | } else { | |
ef2fbe16 | 4041 | iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash); |
673feb9d | 4042 | } |
ef2fbe16 | 4043 | |
33dc9b12 SR |
4044 | if (!iter->hash) { |
4045 | trace_parser_put(&iter->parser); | |
3f2367ba | 4046 | goto out_unlock; |
33dc9b12 | 4047 | } |
c20489da SRV |
4048 | } else |
4049 | iter->hash = hash; | |
1cf41dd7 | 4050 | |
9ef16693 SRV |
4051 | ret = 0; |
4052 | ||
5072c59f SR |
4053 | if (file->f_mode & FMODE_READ) { |
4054 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
4055 | |
4056 | ret = seq_open(file, &show_ftrace_seq_ops); | |
4057 | if (!ret) { | |
4058 | struct seq_file *m = file->private_data; | |
4059 | m->private = iter; | |
79fe249c | 4060 | } else { |
33dc9b12 SR |
4061 | /* Failed */ |
4062 | free_ftrace_hash(iter->hash); | |
79fe249c | 4063 | trace_parser_put(&iter->parser); |
79fe249c | 4064 | } |
5072c59f SR |
4065 | } else |
4066 | file->private_data = iter; | |
3f2367ba MH |
4067 | |
4068 | out_unlock: | |
33b7f99c | 4069 | mutex_unlock(&ops->func_hash->regex_lock); |
5072c59f | 4070 | |
9ef16693 SRV |
4071 | out: |
4072 | if (ret) { | |
4073 | kfree(iter); | |
4074 | if (tr) | |
4075 | trace_array_put(tr); | |
4076 | } | |
4077 | ||
5072c59f SR |
4078 | return ret; |
4079 | } | |
4080 | ||
41c52c0d SR |
4081 | static int |
4082 | ftrace_filter_open(struct inode *inode, struct file *file) | |
4083 | { | |
e3b3e2e8 SRRH |
4084 | struct ftrace_ops *ops = inode->i_private; |
4085 | ||
17911ff3 | 4086 | /* Checks for tracefs lockdown */ |
e3b3e2e8 | 4087 | return ftrace_regex_open(ops, |
eee8ded1 | 4088 | FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES, |
69a3083c | 4089 | inode, file); |
41c52c0d SR |
4090 | } |
4091 | ||
4092 | static int | |
4093 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
4094 | { | |
e3b3e2e8 SRRH |
4095 | struct ftrace_ops *ops = inode->i_private; |
4096 | ||
17911ff3 | 4097 | /* Checks for tracefs lockdown */ |
e3b3e2e8 | 4098 | return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE, |
1cf41dd7 | 4099 | inode, file); |
41c52c0d SR |
4100 | } |
4101 | ||
3ba00929 DS |
4102 | /* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */ |
4103 | struct ftrace_glob { | |
4104 | char *search; | |
4105 | unsigned len; | |
4106 | int type; | |
4107 | }; | |
4108 | ||
7132e2d6 TJB |
4109 | /* |
4110 | * If symbols in an architecture don't correspond exactly to the user-visible | |
4111 | * name of what they represent, it is possible to define this function to | |
4112 | * perform the necessary adjustments. | |
4113 | */ | |
4114 | char * __weak arch_ftrace_match_adjust(char *str, const char *search) | |
4115 | { | |
4116 | return str; | |
4117 | } | |
4118 | ||
3ba00929 | 4119 | static int ftrace_match(char *str, struct ftrace_glob *g) |
9f4801e3 | 4120 | { |
9f4801e3 | 4121 | int matched = 0; |
751e9983 | 4122 | int slen; |
9f4801e3 | 4123 | |
7132e2d6 TJB |
4124 | str = arch_ftrace_match_adjust(str, g->search); |
4125 | ||
3ba00929 | 4126 | switch (g->type) { |
9f4801e3 | 4127 | case MATCH_FULL: |
3ba00929 | 4128 | if (strcmp(str, g->search) == 0) |
9f4801e3 SR |
4129 | matched = 1; |
4130 | break; | |
4131 | case MATCH_FRONT_ONLY: | |
3ba00929 | 4132 | if (strncmp(str, g->search, g->len) == 0) |
9f4801e3 SR |
4133 | matched = 1; |
4134 | break; | |
4135 | case MATCH_MIDDLE_ONLY: | |
3ba00929 | 4136 | if (strstr(str, g->search)) |
9f4801e3 SR |
4137 | matched = 1; |
4138 | break; | |
4139 | case MATCH_END_ONLY: | |
751e9983 | 4140 | slen = strlen(str); |
3ba00929 DS |
4141 | if (slen >= g->len && |
4142 | memcmp(str + slen - g->len, g->search, g->len) == 0) | |
9f4801e3 SR |
4143 | matched = 1; |
4144 | break; | |
60f1d5e3 MH |
4145 | case MATCH_GLOB: |
4146 | if (glob_match(g->search, str)) | |
4147 | matched = 1; | |
4148 | break; | |
9f4801e3 SR |
4149 | } |
4150 | ||
4151 | return matched; | |
4152 | } | |
4153 | ||
b448c4e3 | 4154 | static int |
f0a3b154 | 4155 | enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter) |
996e87be | 4156 | { |
b448c4e3 | 4157 | struct ftrace_func_entry *entry; |
b448c4e3 SR |
4158 | int ret = 0; |
4159 | ||
1cf41dd7 | 4160 | entry = ftrace_lookup_ip(hash, rec->ip); |
f0a3b154 | 4161 | if (clear_filter) { |
1cf41dd7 SR |
4162 | /* Do nothing if it doesn't exist */ |
4163 | if (!entry) | |
4164 | return 0; | |
b448c4e3 | 4165 | |
33dc9b12 | 4166 | free_hash_entry(hash, entry); |
1cf41dd7 SR |
4167 | } else { |
4168 | /* Do nothing if it exists */ | |
4169 | if (entry) | |
4170 | return 0; | |
b448c4e3 | 4171 | |
1cf41dd7 | 4172 | ret = add_hash_entry(hash, rec->ip); |
b448c4e3 SR |
4173 | } |
4174 | return ret; | |
996e87be SR |
4175 | } |
4176 | ||
f79b3f33 SRV |
4177 | static int |
4178 | add_rec_by_index(struct ftrace_hash *hash, struct ftrace_glob *func_g, | |
4179 | int clear_filter) | |
4180 | { | |
4181 | long index = simple_strtoul(func_g->search, NULL, 0); | |
4182 | struct ftrace_page *pg; | |
4183 | struct dyn_ftrace *rec; | |
4184 | ||
4185 | /* The index starts at 1 */ | |
4186 | if (--index < 0) | |
4187 | return 0; | |
4188 | ||
4189 | do_for_each_ftrace_rec(pg, rec) { | |
4190 | if (pg->index <= index) { | |
4191 | index -= pg->index; | |
4192 | /* this is a double loop, break goes to the next page */ | |
4193 | break; | |
4194 | } | |
4195 | rec = &pg->records[index]; | |
4196 | enter_record(hash, rec, clear_filter); | |
4197 | return 1; | |
4198 | } while_for_each_ftrace_rec(); | |
4199 | return 0; | |
4200 | } | |
4201 | ||
b39181f7 SRG |
4202 | #ifdef FTRACE_MCOUNT_MAX_OFFSET |
4203 | static int lookup_ip(unsigned long ip, char **modname, char *str) | |
4204 | { | |
4205 | unsigned long offset; | |
4206 | ||
4207 | kallsyms_lookup(ip, NULL, &offset, modname, str); | |
4208 | if (offset > FTRACE_MCOUNT_MAX_OFFSET) | |
4209 | return -1; | |
4210 | return 0; | |
4211 | } | |
4212 | #else | |
4213 | static int lookup_ip(unsigned long ip, char **modname, char *str) | |
4214 | { | |
4215 | kallsyms_lookup(ip, NULL, NULL, modname, str); | |
4216 | return 0; | |
4217 | } | |
4218 | #endif | |
4219 | ||
64e7c440 | 4220 | static int |
0b507e1e DS |
4221 | ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g, |
4222 | struct ftrace_glob *mod_g, int exclude_mod) | |
64e7c440 SR |
4223 | { |
4224 | char str[KSYM_SYMBOL_LEN]; | |
b9df92d2 SR |
4225 | char *modname; |
4226 | ||
b39181f7 SRG |
4227 | if (lookup_ip(rec->ip, &modname, str)) { |
4228 | /* This should only happen when a rec is disabled */ | |
4229 | WARN_ON_ONCE(system_state == SYSTEM_RUNNING && | |
4230 | !(rec->flags & FTRACE_FL_DISABLED)); | |
4231 | return 0; | |
4232 | } | |
b9df92d2 | 4233 | |
0b507e1e DS |
4234 | if (mod_g) { |
4235 | int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0; | |
4236 | ||
4237 | /* blank module name to match all modules */ | |
4238 | if (!mod_g->len) { | |
4239 | /* blank module globbing: modname xor exclude_mod */ | |
77c0edde | 4240 | if (!exclude_mod != !modname) |
0b507e1e DS |
4241 | goto func_match; |
4242 | return 0; | |
4243 | } | |
4244 | ||
77c0edde SRV |
4245 | /* |
4246 | * exclude_mod is set to trace everything but the given | |
4247 | * module. If it is set and the module matches, then | |
4248 | * return 0. If it is not set, and the module doesn't match | |
4249 | * also return 0. Otherwise, check the function to see if | |
4250 | * that matches. | |
4251 | */ | |
4252 | if (!mod_matches == !exclude_mod) | |
b9df92d2 | 4253 | return 0; |
0b507e1e | 4254 | func_match: |
b9df92d2 | 4255 | /* blank search means to match all funcs in the mod */ |
3ba00929 | 4256 | if (!func_g->len) |
b9df92d2 SR |
4257 | return 1; |
4258 | } | |
64e7c440 | 4259 | |
3ba00929 | 4260 | return ftrace_match(str, func_g); |
64e7c440 SR |
4261 | } |
4262 | ||
1cf41dd7 | 4263 | static int |
3ba00929 | 4264 | match_records(struct ftrace_hash *hash, char *func, int len, char *mod) |
9f4801e3 | 4265 | { |
9f4801e3 SR |
4266 | struct ftrace_page *pg; |
4267 | struct dyn_ftrace *rec; | |
3ba00929 | 4268 | struct ftrace_glob func_g = { .type = MATCH_FULL }; |
0b507e1e DS |
4269 | struct ftrace_glob mod_g = { .type = MATCH_FULL }; |
4270 | struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL; | |
4271 | int exclude_mod = 0; | |
311d16da | 4272 | int found = 0; |
b448c4e3 | 4273 | int ret; |
2e028c4f | 4274 | int clear_filter = 0; |
9f4801e3 | 4275 | |
0b507e1e | 4276 | if (func) { |
3ba00929 DS |
4277 | func_g.type = filter_parse_regex(func, len, &func_g.search, |
4278 | &clear_filter); | |
4279 | func_g.len = strlen(func_g.search); | |
b9df92d2 | 4280 | } |
9f4801e3 | 4281 | |
0b507e1e DS |
4282 | if (mod) { |
4283 | mod_g.type = filter_parse_regex(mod, strlen(mod), | |
4284 | &mod_g.search, &exclude_mod); | |
4285 | mod_g.len = strlen(mod_g.search); | |
b9df92d2 | 4286 | } |
9f4801e3 | 4287 | |
52baf119 | 4288 | mutex_lock(&ftrace_lock); |
265c831c | 4289 | |
b9df92d2 SR |
4290 | if (unlikely(ftrace_disabled)) |
4291 | goto out_unlock; | |
9f4801e3 | 4292 | |
f79b3f33 SRV |
4293 | if (func_g.type == MATCH_INDEX) { |
4294 | found = add_rec_by_index(hash, &func_g, clear_filter); | |
4295 | goto out_unlock; | |
4296 | } | |
4297 | ||
265c831c | 4298 | do_for_each_ftrace_rec(pg, rec) { |
546fece4 SRRH |
4299 | |
4300 | if (rec->flags & FTRACE_FL_DISABLED) | |
4301 | continue; | |
4302 | ||
0b507e1e | 4303 | if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) { |
f0a3b154 | 4304 | ret = enter_record(hash, rec, clear_filter); |
b448c4e3 SR |
4305 | if (ret < 0) { |
4306 | found = ret; | |
4307 | goto out_unlock; | |
4308 | } | |
311d16da | 4309 | found = 1; |
265c831c | 4310 | } |
d0b24b4e | 4311 | cond_resched(); |
265c831c | 4312 | } while_for_each_ftrace_rec(); |
b9df92d2 | 4313 | out_unlock: |
52baf119 | 4314 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
4315 | |
4316 | return found; | |
5072c59f SR |
4317 | } |
4318 | ||
64e7c440 | 4319 | static int |
1cf41dd7 | 4320 | ftrace_match_records(struct ftrace_hash *hash, char *buff, int len) |
64e7c440 | 4321 | { |
f0a3b154 | 4322 | return match_records(hash, buff, len, NULL); |
64e7c440 SR |
4323 | } |
4324 | ||
e16b35dd SRV |
4325 | static void ftrace_ops_update_code(struct ftrace_ops *ops, |
4326 | struct ftrace_ops_hash *old_hash) | |
4327 | { | |
4328 | struct ftrace_ops *op; | |
4329 | ||
4330 | if (!ftrace_enabled) | |
4331 | return; | |
4332 | ||
4333 | if (ops->flags & FTRACE_OPS_FL_ENABLED) { | |
4334 | ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash); | |
4335 | return; | |
4336 | } | |
4337 | ||
4338 | /* | |
4339 | * If this is the shared global_ops filter, then we need to | |
4340 | * check if there is another ops that shares it, is enabled. | |
4341 | * If so, we still need to run the modify code. | |
4342 | */ | |
4343 | if (ops->func_hash != &global_ops.local_hash) | |
4344 | return; | |
4345 | ||
4346 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
4347 | if (op->func_hash == &global_ops.local_hash && | |
4348 | op->flags & FTRACE_OPS_FL_ENABLED) { | |
4349 | ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash); | |
4350 | /* Only need to do this once */ | |
4351 | return; | |
4352 | } | |
4353 | } while_for_each_ftrace_op(op); | |
4354 | } | |
4355 | ||
4356 | static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops, | |
4357 | struct ftrace_hash **orig_hash, | |
4358 | struct ftrace_hash *hash, | |
4359 | int enable) | |
4360 | { | |
4361 | struct ftrace_ops_hash old_hash_ops; | |
4362 | struct ftrace_hash *old_hash; | |
4363 | int ret; | |
4364 | ||
4365 | old_hash = *orig_hash; | |
4366 | old_hash_ops.filter_hash = ops->func_hash->filter_hash; | |
4367 | old_hash_ops.notrace_hash = ops->func_hash->notrace_hash; | |
4368 | ret = ftrace_hash_move(ops, enable, orig_hash, hash); | |
4369 | if (!ret) { | |
4370 | ftrace_ops_update_code(ops, &old_hash_ops); | |
4371 | free_ftrace_hash_rcu(old_hash); | |
4372 | } | |
4373 | return ret; | |
4374 | } | |
64e7c440 | 4375 | |
673feb9d SRV |
4376 | static bool module_exists(const char *module) |
4377 | { | |
4378 | /* All modules have the symbol __this_module */ | |
0f5e5a3a | 4379 | static const char this_mod[] = "__this_module"; |
419e9fe5 | 4380 | char modname[MAX_PARAM_PREFIX_LEN + sizeof(this_mod) + 2]; |
673feb9d SRV |
4381 | unsigned long val; |
4382 | int n; | |
4383 | ||
419e9fe5 | 4384 | n = snprintf(modname, sizeof(modname), "%s:%s", module, this_mod); |
673feb9d | 4385 | |
419e9fe5 | 4386 | if (n > sizeof(modname) - 1) |
673feb9d SRV |
4387 | return false; |
4388 | ||
4389 | val = module_kallsyms_lookup_name(modname); | |
4390 | return val != 0; | |
4391 | } | |
4392 | ||
4393 | static int cache_mod(struct trace_array *tr, | |
4394 | const char *func, char *module, int enable) | |
4395 | { | |
4396 | struct ftrace_mod_load *ftrace_mod, *n; | |
4397 | struct list_head *head = enable ? &tr->mod_trace : &tr->mod_notrace; | |
4398 | int ret; | |
4399 | ||
4400 | mutex_lock(&ftrace_lock); | |
4401 | ||
4402 | /* We do not cache inverse filters */ | |
4403 | if (func[0] == '!') { | |
4404 | func++; | |
4405 | ret = -EINVAL; | |
4406 | ||
4407 | /* Look to remove this hash */ | |
4408 | list_for_each_entry_safe(ftrace_mod, n, head, list) { | |
4409 | if (strcmp(ftrace_mod->module, module) != 0) | |
4410 | continue; | |
4411 | ||
4412 | /* no func matches all */ | |
44925dff | 4413 | if (strcmp(func, "*") == 0 || |
673feb9d SRV |
4414 | (ftrace_mod->func && |
4415 | strcmp(ftrace_mod->func, func) == 0)) { | |
4416 | ret = 0; | |
4417 | free_ftrace_mod(ftrace_mod); | |
4418 | continue; | |
4419 | } | |
4420 | } | |
4421 | goto out; | |
4422 | } | |
4423 | ||
4424 | ret = -EINVAL; | |
4425 | /* We only care about modules that have not been loaded yet */ | |
4426 | if (module_exists(module)) | |
4427 | goto out; | |
4428 | ||
4429 | /* Save this string off, and execute it when the module is loaded */ | |
4430 | ret = ftrace_add_mod(tr, func, module, enable); | |
4431 | out: | |
4432 | mutex_unlock(&ftrace_lock); | |
4433 | ||
4434 | return ret; | |
4435 | } | |
4436 | ||
d7fbf8df SRV |
4437 | static int |
4438 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, | |
4439 | int reset, int enable); | |
4440 | ||
69449bbd | 4441 | #ifdef CONFIG_MODULES |
d7fbf8df SRV |
4442 | static void process_mod_list(struct list_head *head, struct ftrace_ops *ops, |
4443 | char *mod, bool enable) | |
4444 | { | |
4445 | struct ftrace_mod_load *ftrace_mod, *n; | |
4446 | struct ftrace_hash **orig_hash, *new_hash; | |
4447 | LIST_HEAD(process_mods); | |
4448 | char *func; | |
d7fbf8df SRV |
4449 | |
4450 | mutex_lock(&ops->func_hash->regex_lock); | |
4451 | ||
4452 | if (enable) | |
4453 | orig_hash = &ops->func_hash->filter_hash; | |
4454 | else | |
4455 | orig_hash = &ops->func_hash->notrace_hash; | |
4456 | ||
4457 | new_hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, | |
4458 | *orig_hash); | |
4459 | if (!new_hash) | |
3b58a3c7 | 4460 | goto out; /* warn? */ |
d7fbf8df SRV |
4461 | |
4462 | mutex_lock(&ftrace_lock); | |
4463 | ||
4464 | list_for_each_entry_safe(ftrace_mod, n, head, list) { | |
4465 | ||
4466 | if (strcmp(ftrace_mod->module, mod) != 0) | |
4467 | continue; | |
4468 | ||
4469 | if (ftrace_mod->func) | |
4470 | func = kstrdup(ftrace_mod->func, GFP_KERNEL); | |
4471 | else | |
4472 | func = kstrdup("*", GFP_KERNEL); | |
4473 | ||
4474 | if (!func) /* warn? */ | |
4475 | continue; | |
4476 | ||
3ecda644 | 4477 | list_move(&ftrace_mod->list, &process_mods); |
d7fbf8df SRV |
4478 | |
4479 | /* Use the newly allocated func, as it may be "*" */ | |
4480 | kfree(ftrace_mod->func); | |
4481 | ftrace_mod->func = func; | |
4482 | } | |
4483 | ||
4484 | mutex_unlock(&ftrace_lock); | |
4485 | ||
4486 | list_for_each_entry_safe(ftrace_mod, n, &process_mods, list) { | |
4487 | ||
4488 | func = ftrace_mod->func; | |
4489 | ||
4490 | /* Grabs ftrace_lock, which is why we have this extra step */ | |
4491 | match_records(new_hash, func, strlen(func), mod); | |
4492 | free_ftrace_mod(ftrace_mod); | |
4493 | } | |
4494 | ||
8c08f0d5 SRV |
4495 | if (enable && list_empty(head)) |
4496 | new_hash->flags &= ~FTRACE_HASH_FL_MOD; | |
4497 | ||
d7fbf8df SRV |
4498 | mutex_lock(&ftrace_lock); |
4499 | ||
045e269c | 4500 | ftrace_hash_move_and_update_ops(ops, orig_hash, |
d7fbf8df SRV |
4501 | new_hash, enable); |
4502 | mutex_unlock(&ftrace_lock); | |
4503 | ||
3b58a3c7 | 4504 | out: |
d7fbf8df SRV |
4505 | mutex_unlock(&ops->func_hash->regex_lock); |
4506 | ||
4507 | free_ftrace_hash(new_hash); | |
4508 | } | |
4509 | ||
4510 | static void process_cached_mods(const char *mod_name) | |
4511 | { | |
4512 | struct trace_array *tr; | |
4513 | char *mod; | |
4514 | ||
4515 | mod = kstrdup(mod_name, GFP_KERNEL); | |
4516 | if (!mod) | |
4517 | return; | |
4518 | ||
4519 | mutex_lock(&trace_types_lock); | |
4520 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
4521 | if (!list_empty(&tr->mod_trace)) | |
4522 | process_mod_list(&tr->mod_trace, tr->ops, mod, true); | |
4523 | if (!list_empty(&tr->mod_notrace)) | |
4524 | process_mod_list(&tr->mod_notrace, tr->ops, mod, false); | |
4525 | } | |
4526 | mutex_unlock(&trace_types_lock); | |
4527 | ||
4528 | kfree(mod); | |
4529 | } | |
69449bbd | 4530 | #endif |
d7fbf8df | 4531 | |
f6180773 SR |
4532 | /* |
4533 | * We register the module command as a template to show others how | |
4534 | * to register the a command as well. | |
4535 | */ | |
4536 | ||
4537 | static int | |
04ec7bb6 | 4538 | ftrace_mod_callback(struct trace_array *tr, struct ftrace_hash *hash, |
673feb9d | 4539 | char *func_orig, char *cmd, char *module, int enable) |
f6180773 | 4540 | { |
673feb9d | 4541 | char *func; |
5e3949f0 | 4542 | int ret; |
f6180773 | 4543 | |
673feb9d SRV |
4544 | /* match_records() modifies func, and we need the original */ |
4545 | func = kstrdup(func_orig, GFP_KERNEL); | |
4546 | if (!func) | |
4547 | return -ENOMEM; | |
4548 | ||
f6180773 SR |
4549 | /* |
4550 | * cmd == 'mod' because we only registered this func | |
4551 | * for the 'mod' ftrace_func_command. | |
4552 | * But if you register one func with multiple commands, | |
4553 | * you can tell which command was used by the cmd | |
4554 | * parameter. | |
4555 | */ | |
f0a3b154 | 4556 | ret = match_records(hash, func, strlen(func), module); |
673feb9d SRV |
4557 | kfree(func); |
4558 | ||
b448c4e3 | 4559 | if (!ret) |
673feb9d | 4560 | return cache_mod(tr, func_orig, module, enable); |
b448c4e3 SR |
4561 | if (ret < 0) |
4562 | return ret; | |
b448c4e3 | 4563 | return 0; |
f6180773 SR |
4564 | } |
4565 | ||
4566 | static struct ftrace_func_command ftrace_mod_cmd = { | |
4567 | .name = "mod", | |
4568 | .func = ftrace_mod_callback, | |
4569 | }; | |
4570 | ||
4571 | static int __init ftrace_mod_cmd_init(void) | |
4572 | { | |
4573 | return register_ftrace_command(&ftrace_mod_cmd); | |
4574 | } | |
6f415672 | 4575 | core_initcall(ftrace_mod_cmd_init); |
f6180773 | 4576 | |
2f5f6ad9 | 4577 | static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, |
d19ad077 | 4578 | struct ftrace_ops *op, struct ftrace_regs *fregs) |
59df055f | 4579 | { |
eee8ded1 | 4580 | struct ftrace_probe_ops *probe_ops; |
7b60f3d8 | 4581 | struct ftrace_func_probe *probe; |
59df055f | 4582 | |
7b60f3d8 SRV |
4583 | probe = container_of(op, struct ftrace_func_probe, ops); |
4584 | probe_ops = probe->probe_ops; | |
59df055f SR |
4585 | |
4586 | /* | |
4587 | * Disable preemption for these calls to prevent a RCU grace | |
4588 | * period. This syncs the hash iteration and freeing of items | |
4589 | * on the hash. rcu_read_lock is too dangerous here. | |
4590 | */ | |
5168ae50 | 4591 | preempt_disable_notrace(); |
6e444319 | 4592 | probe_ops->func(ip, parent_ip, probe->tr, probe_ops, probe->data); |
5168ae50 | 4593 | preempt_enable_notrace(); |
59df055f SR |
4594 | } |
4595 | ||
41794f19 SRV |
4596 | struct ftrace_func_map { |
4597 | struct ftrace_func_entry entry; | |
4598 | void *data; | |
59df055f SR |
4599 | }; |
4600 | ||
41794f19 SRV |
4601 | struct ftrace_func_mapper { |
4602 | struct ftrace_hash hash; | |
4603 | }; | |
59df055f | 4604 | |
41794f19 SRV |
4605 | /** |
4606 | * allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper | |
4607 | * | |
4608 | * Returns a ftrace_func_mapper descriptor that can be used to map ips to data. | |
4609 | */ | |
4610 | struct ftrace_func_mapper *allocate_ftrace_func_mapper(void) | |
59df055f | 4611 | { |
41794f19 | 4612 | struct ftrace_hash *hash; |
59df055f | 4613 | |
41794f19 SRV |
4614 | /* |
4615 | * The mapper is simply a ftrace_hash, but since the entries | |
4616 | * in the hash are not ftrace_func_entry type, we define it | |
4617 | * as a separate structure. | |
4618 | */ | |
4619 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); | |
4620 | return (struct ftrace_func_mapper *)hash; | |
4621 | } | |
59df055f | 4622 | |
41794f19 SRV |
4623 | /** |
4624 | * ftrace_func_mapper_find_ip - Find some data mapped to an ip | |
4625 | * @mapper: The mapper that has the ip maps | |
4626 | * @ip: the instruction pointer to find the data for | |
4627 | * | |
4628 | * Returns the data mapped to @ip if found otherwise NULL. The return | |
4629 | * is actually the address of the mapper data pointer. The address is | |
4630 | * returned for use cases where the data is no bigger than a long, and | |
4631 | * the user can use the data pointer as its data instead of having to | |
4632 | * allocate more memory for the reference. | |
4633 | */ | |
4634 | void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper, | |
4635 | unsigned long ip) | |
4636 | { | |
4637 | struct ftrace_func_entry *entry; | |
4638 | struct ftrace_func_map *map; | |
59df055f | 4639 | |
41794f19 SRV |
4640 | entry = ftrace_lookup_ip(&mapper->hash, ip); |
4641 | if (!entry) | |
4642 | return NULL; | |
b848914c | 4643 | |
41794f19 SRV |
4644 | map = (struct ftrace_func_map *)entry; |
4645 | return &map->data; | |
59df055f SR |
4646 | } |
4647 | ||
41794f19 SRV |
4648 | /** |
4649 | * ftrace_func_mapper_add_ip - Map some data to an ip | |
4650 | * @mapper: The mapper that has the ip maps | |
4651 | * @ip: The instruction pointer address to map @data to | |
4652 | * @data: The data to map to @ip | |
4653 | * | |
fdda88d3 | 4654 | * Returns 0 on success otherwise an error. |
41794f19 SRV |
4655 | */ |
4656 | int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper, | |
4657 | unsigned long ip, void *data) | |
59df055f | 4658 | { |
41794f19 SRV |
4659 | struct ftrace_func_entry *entry; |
4660 | struct ftrace_func_map *map; | |
59df055f | 4661 | |
41794f19 SRV |
4662 | entry = ftrace_lookup_ip(&mapper->hash, ip); |
4663 | if (entry) | |
4664 | return -EBUSY; | |
59df055f | 4665 | |
41794f19 SRV |
4666 | map = kmalloc(sizeof(*map), GFP_KERNEL); |
4667 | if (!map) | |
4668 | return -ENOMEM; | |
59df055f | 4669 | |
41794f19 SRV |
4670 | map->entry.ip = ip; |
4671 | map->data = data; | |
b848914c | 4672 | |
41794f19 | 4673 | __add_hash_entry(&mapper->hash, &map->entry); |
59df055f | 4674 | |
41794f19 SRV |
4675 | return 0; |
4676 | } | |
59df055f | 4677 | |
41794f19 SRV |
4678 | /** |
4679 | * ftrace_func_mapper_remove_ip - Remove an ip from the mapping | |
4680 | * @mapper: The mapper that has the ip maps | |
4681 | * @ip: The instruction pointer address to remove the data from | |
4682 | * | |
4683 | * Returns the data if it is found, otherwise NULL. | |
7d54c15c | 4684 | * Note, if the data pointer is used as the data itself, (see |
41794f19 SRV |
4685 | * ftrace_func_mapper_find_ip(), then the return value may be meaningless, |
4686 | * if the data pointer was set to zero. | |
4687 | */ | |
4688 | void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper, | |
4689 | unsigned long ip) | |
59df055f | 4690 | { |
41794f19 SRV |
4691 | struct ftrace_func_entry *entry; |
4692 | struct ftrace_func_map *map; | |
4693 | void *data; | |
4694 | ||
4695 | entry = ftrace_lookup_ip(&mapper->hash, ip); | |
4696 | if (!entry) | |
4697 | return NULL; | |
4698 | ||
4699 | map = (struct ftrace_func_map *)entry; | |
4700 | data = map->data; | |
4701 | ||
4702 | remove_hash_entry(&mapper->hash, entry); | |
59df055f | 4703 | kfree(entry); |
41794f19 SRV |
4704 | |
4705 | return data; | |
4706 | } | |
4707 | ||
4708 | /** | |
4709 | * free_ftrace_func_mapper - free a mapping of ips and data | |
4710 | * @mapper: The mapper that has the ip maps | |
4711 | * @free_func: A function to be called on each data item. | |
4712 | * | |
4713 | * This is used to free the function mapper. The @free_func is optional | |
4714 | * and can be used if the data needs to be freed as well. | |
4715 | */ | |
4716 | void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper, | |
4717 | ftrace_mapper_func free_func) | |
4718 | { | |
4719 | struct ftrace_func_entry *entry; | |
4720 | struct ftrace_func_map *map; | |
4721 | struct hlist_head *hhd; | |
04e03d9a WL |
4722 | int size, i; |
4723 | ||
4724 | if (!mapper) | |
4725 | return; | |
41794f19 SRV |
4726 | |
4727 | if (free_func && mapper->hash.count) { | |
04e03d9a | 4728 | size = 1 << mapper->hash.size_bits; |
41794f19 SRV |
4729 | for (i = 0; i < size; i++) { |
4730 | hhd = &mapper->hash.buckets[i]; | |
4731 | hlist_for_each_entry(entry, hhd, hlist) { | |
4732 | map = (struct ftrace_func_map *)entry; | |
4733 | free_func(map); | |
4734 | } | |
4735 | } | |
4736 | } | |
4737 | free_ftrace_hash(&mapper->hash); | |
4738 | } | |
4739 | ||
7b60f3d8 SRV |
4740 | static void release_probe(struct ftrace_func_probe *probe) |
4741 | { | |
4742 | struct ftrace_probe_ops *probe_ops; | |
4743 | ||
4744 | mutex_lock(&ftrace_lock); | |
4745 | ||
4746 | WARN_ON(probe->ref <= 0); | |
4747 | ||
4748 | /* Subtract the ref that was used to protect this instance */ | |
4749 | probe->ref--; | |
4750 | ||
4751 | if (!probe->ref) { | |
4752 | probe_ops = probe->probe_ops; | |
6e444319 SRV |
4753 | /* |
4754 | * Sending zero as ip tells probe_ops to free | |
4755 | * the probe->data itself | |
4756 | */ | |
4757 | if (probe_ops->free) | |
4758 | probe_ops->free(probe_ops, probe->tr, 0, probe->data); | |
7b60f3d8 SRV |
4759 | list_del(&probe->list); |
4760 | kfree(probe); | |
4761 | } | |
4762 | mutex_unlock(&ftrace_lock); | |
4763 | } | |
4764 | ||
4765 | static void acquire_probe_locked(struct ftrace_func_probe *probe) | |
4766 | { | |
4767 | /* | |
4768 | * Add one ref to keep it from being freed when releasing the | |
4769 | * ftrace_lock mutex. | |
4770 | */ | |
4771 | probe->ref++; | |
59df055f SR |
4772 | } |
4773 | ||
59df055f | 4774 | int |
04ec7bb6 | 4775 | register_ftrace_function_probe(char *glob, struct trace_array *tr, |
7b60f3d8 SRV |
4776 | struct ftrace_probe_ops *probe_ops, |
4777 | void *data) | |
59df055f | 4778 | { |
ba27d855 | 4779 | struct ftrace_func_probe *probe = NULL, *iter; |
1ec3a81a | 4780 | struct ftrace_func_entry *entry; |
1ec3a81a SRV |
4781 | struct ftrace_hash **orig_hash; |
4782 | struct ftrace_hash *old_hash; | |
e1df4cb6 | 4783 | struct ftrace_hash *hash; |
59df055f | 4784 | int count = 0; |
1ec3a81a | 4785 | int size; |
e1df4cb6 | 4786 | int ret; |
1ec3a81a | 4787 | int i; |
59df055f | 4788 | |
04ec7bb6 | 4789 | if (WARN_ON(!tr)) |
59df055f SR |
4790 | return -EINVAL; |
4791 | ||
1ec3a81a SRV |
4792 | /* We do not support '!' for function probes */ |
4793 | if (WARN_ON(glob[0] == '!')) | |
59df055f | 4794 | return -EINVAL; |
59df055f | 4795 | |
7485058e | 4796 | |
7b60f3d8 SRV |
4797 | mutex_lock(&ftrace_lock); |
4798 | /* Check if the probe_ops is already registered */ | |
ba27d855 JK |
4799 | list_for_each_entry(iter, &tr->func_probes, list) { |
4800 | if (iter->probe_ops == probe_ops) { | |
4801 | probe = iter; | |
7b60f3d8 | 4802 | break; |
ba27d855 | 4803 | } |
e1df4cb6 | 4804 | } |
ba27d855 | 4805 | if (!probe) { |
7b60f3d8 SRV |
4806 | probe = kzalloc(sizeof(*probe), GFP_KERNEL); |
4807 | if (!probe) { | |
4808 | mutex_unlock(&ftrace_lock); | |
4809 | return -ENOMEM; | |
4810 | } | |
4811 | probe->probe_ops = probe_ops; | |
4812 | probe->ops.func = function_trace_probe_call; | |
4813 | probe->tr = tr; | |
4814 | ftrace_ops_init(&probe->ops); | |
4815 | list_add(&probe->list, &tr->func_probes); | |
e1df4cb6 | 4816 | } |
59df055f | 4817 | |
7b60f3d8 | 4818 | acquire_probe_locked(probe); |
5ae0bf59 | 4819 | |
7b60f3d8 | 4820 | mutex_unlock(&ftrace_lock); |
59df055f | 4821 | |
372e0d01 SRV |
4822 | /* |
4823 | * Note, there's a small window here that the func_hash->filter_hash | |
fdda88d3 | 4824 | * may be NULL or empty. Need to be careful when reading the loop. |
372e0d01 | 4825 | */ |
7b60f3d8 | 4826 | mutex_lock(&probe->ops.func_hash->regex_lock); |
546fece4 | 4827 | |
7b60f3d8 | 4828 | orig_hash = &probe->ops.func_hash->filter_hash; |
1ec3a81a SRV |
4829 | old_hash = *orig_hash; |
4830 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); | |
59df055f | 4831 | |
5b0022dd NR |
4832 | if (!hash) { |
4833 | ret = -ENOMEM; | |
4834 | goto out; | |
4835 | } | |
4836 | ||
1ec3a81a | 4837 | ret = ftrace_match_records(hash, glob, strlen(glob)); |
59df055f | 4838 | |
1ec3a81a SRV |
4839 | /* Nothing found? */ |
4840 | if (!ret) | |
4841 | ret = -EINVAL; | |
59df055f | 4842 | |
1ec3a81a SRV |
4843 | if (ret < 0) |
4844 | goto out; | |
59df055f | 4845 | |
1ec3a81a SRV |
4846 | size = 1 << hash->size_bits; |
4847 | for (i = 0; i < size; i++) { | |
4848 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
4849 | if (ftrace_lookup_ip(old_hash, entry->ip)) | |
59df055f | 4850 | continue; |
1ec3a81a SRV |
4851 | /* |
4852 | * The caller might want to do something special | |
4853 | * for each function we find. We call the callback | |
4854 | * to give the caller an opportunity to do so. | |
4855 | */ | |
7b60f3d8 SRV |
4856 | if (probe_ops->init) { |
4857 | ret = probe_ops->init(probe_ops, tr, | |
6e444319 SRV |
4858 | entry->ip, data, |
4859 | &probe->data); | |
4860 | if (ret < 0) { | |
4861 | if (probe_ops->free && count) | |
4862 | probe_ops->free(probe_ops, tr, | |
4863 | 0, probe->data); | |
4864 | probe->data = NULL; | |
eee8ded1 | 4865 | goto out; |
6e444319 | 4866 | } |
59df055f | 4867 | } |
1ec3a81a | 4868 | count++; |
59df055f | 4869 | } |
1ec3a81a | 4870 | } |
59df055f | 4871 | |
1ec3a81a | 4872 | mutex_lock(&ftrace_lock); |
59df055f | 4873 | |
7b60f3d8 SRV |
4874 | if (!count) { |
4875 | /* Nothing was added? */ | |
4876 | ret = -EINVAL; | |
4877 | goto out_unlock; | |
4878 | } | |
e1df4cb6 | 4879 | |
7b60f3d8 SRV |
4880 | ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash, |
4881 | hash, 1); | |
1ec3a81a | 4882 | if (ret < 0) |
8d70725e | 4883 | goto err_unlock; |
8252ecf3 | 4884 | |
7b60f3d8 SRV |
4885 | /* One ref for each new function traced */ |
4886 | probe->ref += count; | |
8252ecf3 | 4887 | |
7b60f3d8 SRV |
4888 | if (!(probe->ops.flags & FTRACE_OPS_FL_ENABLED)) |
4889 | ret = ftrace_startup(&probe->ops, 0); | |
e1df4cb6 | 4890 | |
59df055f | 4891 | out_unlock: |
5ae0bf59 | 4892 | mutex_unlock(&ftrace_lock); |
8252ecf3 | 4893 | |
3296fc4e | 4894 | if (!ret) |
1ec3a81a | 4895 | ret = count; |
5ae0bf59 | 4896 | out: |
7b60f3d8 | 4897 | mutex_unlock(&probe->ops.func_hash->regex_lock); |
e1df4cb6 | 4898 | free_ftrace_hash(hash); |
59df055f | 4899 | |
7b60f3d8 | 4900 | release_probe(probe); |
59df055f | 4901 | |
1ec3a81a | 4902 | return ret; |
59df055f | 4903 | |
8d70725e | 4904 | err_unlock: |
7b60f3d8 | 4905 | if (!probe_ops->free || !count) |
8d70725e SRV |
4906 | goto out_unlock; |
4907 | ||
4908 | /* Failed to do the move, need to call the free functions */ | |
4909 | for (i = 0; i < size; i++) { | |
4910 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
4911 | if (ftrace_lookup_ip(old_hash, entry->ip)) | |
4912 | continue; | |
6e444319 | 4913 | probe_ops->free(probe_ops, tr, entry->ip, probe->data); |
8d70725e SRV |
4914 | } |
4915 | } | |
4916 | goto out_unlock; | |
59df055f SR |
4917 | } |
4918 | ||
d3d532d7 | 4919 | int |
7b60f3d8 SRV |
4920 | unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr, |
4921 | struct ftrace_probe_ops *probe_ops) | |
59df055f | 4922 | { |
ba27d855 | 4923 | struct ftrace_func_probe *probe = NULL, *iter; |
82cc4fc2 | 4924 | struct ftrace_ops_hash old_hash_ops; |
eee8ded1 | 4925 | struct ftrace_func_entry *entry; |
3ba00929 | 4926 | struct ftrace_glob func_g; |
1ec3a81a SRV |
4927 | struct ftrace_hash **orig_hash; |
4928 | struct ftrace_hash *old_hash; | |
1ec3a81a | 4929 | struct ftrace_hash *hash = NULL; |
b67bfe0d | 4930 | struct hlist_node *tmp; |
eee8ded1 | 4931 | struct hlist_head hhd; |
59df055f | 4932 | char str[KSYM_SYMBOL_LEN]; |
7b60f3d8 SRV |
4933 | int count = 0; |
4934 | int i, ret = -ENODEV; | |
eee8ded1 | 4935 | int size; |
59df055f | 4936 | |
cbab567c | 4937 | if (!glob || !strlen(glob) || !strcmp(glob, "*")) |
3ba00929 | 4938 | func_g.search = NULL; |
cbab567c | 4939 | else { |
59df055f SR |
4940 | int not; |
4941 | ||
3ba00929 DS |
4942 | func_g.type = filter_parse_regex(glob, strlen(glob), |
4943 | &func_g.search, ¬); | |
4944 | func_g.len = strlen(func_g.search); | |
59df055f | 4945 | |
b6887d79 | 4946 | /* we do not support '!' for function probes */ |
59df055f | 4947 | if (WARN_ON(not)) |
d3d532d7 | 4948 | return -EINVAL; |
59df055f SR |
4949 | } |
4950 | ||
7b60f3d8 SRV |
4951 | mutex_lock(&ftrace_lock); |
4952 | /* Check if the probe_ops is already registered */ | |
ba27d855 JK |
4953 | list_for_each_entry(iter, &tr->func_probes, list) { |
4954 | if (iter->probe_ops == probe_ops) { | |
4955 | probe = iter; | |
7b60f3d8 | 4956 | break; |
ba27d855 | 4957 | } |
59df055f | 4958 | } |
ba27d855 | 4959 | if (!probe) |
7b60f3d8 SRV |
4960 | goto err_unlock_ftrace; |
4961 | ||
4962 | ret = -EINVAL; | |
4963 | if (!(probe->ops.flags & FTRACE_OPS_FL_INITIALIZED)) | |
4964 | goto err_unlock_ftrace; | |
4965 | ||
4966 | acquire_probe_locked(probe); | |
4967 | ||
4968 | mutex_unlock(&ftrace_lock); | |
59df055f | 4969 | |
7b60f3d8 | 4970 | mutex_lock(&probe->ops.func_hash->regex_lock); |
1ec3a81a | 4971 | |
7b60f3d8 | 4972 | orig_hash = &probe->ops.func_hash->filter_hash; |
1ec3a81a SRV |
4973 | old_hash = *orig_hash; |
4974 | ||
1ec3a81a SRV |
4975 | if (ftrace_hash_empty(old_hash)) |
4976 | goto out_unlock; | |
e1df4cb6 | 4977 | |
82cc4fc2 SRV |
4978 | old_hash_ops.filter_hash = old_hash; |
4979 | /* Probes only have filters */ | |
4980 | old_hash_ops.notrace_hash = NULL; | |
4981 | ||
d3d532d7 | 4982 | ret = -ENOMEM; |
1ec3a81a | 4983 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); |
e1df4cb6 | 4984 | if (!hash) |
e1df4cb6 SRRH |
4985 | goto out_unlock; |
4986 | ||
eee8ded1 | 4987 | INIT_HLIST_HEAD(&hhd); |
59df055f | 4988 | |
eee8ded1 SRV |
4989 | size = 1 << hash->size_bits; |
4990 | for (i = 0; i < size; i++) { | |
4991 | hlist_for_each_entry_safe(entry, tmp, &hash->buckets[i], hlist) { | |
59df055f | 4992 | |
3ba00929 | 4993 | if (func_g.search) { |
59df055f SR |
4994 | kallsyms_lookup(entry->ip, NULL, NULL, |
4995 | NULL, str); | |
3ba00929 | 4996 | if (!ftrace_match(str, &func_g)) |
59df055f SR |
4997 | continue; |
4998 | } | |
7b60f3d8 | 4999 | count++; |
eee8ded1 SRV |
5000 | remove_hash_entry(hash, entry); |
5001 | hlist_add_head(&entry->hlist, &hhd); | |
59df055f SR |
5002 | } |
5003 | } | |
d3d532d7 SRV |
5004 | |
5005 | /* Nothing found? */ | |
7b60f3d8 | 5006 | if (!count) { |
d3d532d7 SRV |
5007 | ret = -EINVAL; |
5008 | goto out_unlock; | |
5009 | } | |
5010 | ||
3f2367ba | 5011 | mutex_lock(&ftrace_lock); |
1ec3a81a | 5012 | |
7b60f3d8 | 5013 | WARN_ON(probe->ref < count); |
eee8ded1 | 5014 | |
7b60f3d8 | 5015 | probe->ref -= count; |
1ec3a81a | 5016 | |
7b60f3d8 SRV |
5017 | if (ftrace_hash_empty(hash)) |
5018 | ftrace_shutdown(&probe->ops, 0); | |
5019 | ||
5020 | ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash, | |
1ec3a81a | 5021 | hash, 1); |
82cc4fc2 SRV |
5022 | |
5023 | /* still need to update the function call sites */ | |
1ec3a81a | 5024 | if (ftrace_enabled && !ftrace_hash_empty(hash)) |
7b60f3d8 | 5025 | ftrace_run_modify_code(&probe->ops, FTRACE_UPDATE_CALLS, |
82cc4fc2 | 5026 | &old_hash_ops); |
74401729 | 5027 | synchronize_rcu(); |
3296fc4e | 5028 | |
eee8ded1 SRV |
5029 | hlist_for_each_entry_safe(entry, tmp, &hhd, hlist) { |
5030 | hlist_del(&entry->hlist); | |
7b60f3d8 | 5031 | if (probe_ops->free) |
6e444319 | 5032 | probe_ops->free(probe_ops, tr, entry->ip, probe->data); |
eee8ded1 | 5033 | kfree(entry); |
7818b388 | 5034 | } |
3f2367ba | 5035 | mutex_unlock(&ftrace_lock); |
3ba00929 | 5036 | |
e1df4cb6 | 5037 | out_unlock: |
7b60f3d8 | 5038 | mutex_unlock(&probe->ops.func_hash->regex_lock); |
e1df4cb6 | 5039 | free_ftrace_hash(hash); |
59df055f | 5040 | |
7b60f3d8 | 5041 | release_probe(probe); |
59df055f | 5042 | |
7b60f3d8 | 5043 | return ret; |
59df055f | 5044 | |
7b60f3d8 SRV |
5045 | err_unlock_ftrace: |
5046 | mutex_unlock(&ftrace_lock); | |
d3d532d7 | 5047 | return ret; |
59df055f SR |
5048 | } |
5049 | ||
a0e6369e NR |
5050 | void clear_ftrace_function_probes(struct trace_array *tr) |
5051 | { | |
5052 | struct ftrace_func_probe *probe, *n; | |
5053 | ||
5054 | list_for_each_entry_safe(probe, n, &tr->func_probes, list) | |
5055 | unregister_ftrace_function_probe_func(NULL, tr, probe->probe_ops); | |
5056 | } | |
5057 | ||
f6180773 SR |
5058 | static LIST_HEAD(ftrace_commands); |
5059 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
5060 | ||
38de93ab TZ |
5061 | /* |
5062 | * Currently we only register ftrace commands from __init, so mark this | |
5063 | * __init too. | |
5064 | */ | |
5065 | __init int register_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
5066 | { |
5067 | struct ftrace_func_command *p; | |
5068 | int ret = 0; | |
5069 | ||
5070 | mutex_lock(&ftrace_cmd_mutex); | |
5071 | list_for_each_entry(p, &ftrace_commands, list) { | |
5072 | if (strcmp(cmd->name, p->name) == 0) { | |
5073 | ret = -EBUSY; | |
5074 | goto out_unlock; | |
5075 | } | |
5076 | } | |
5077 | list_add(&cmd->list, &ftrace_commands); | |
5078 | out_unlock: | |
5079 | mutex_unlock(&ftrace_cmd_mutex); | |
5080 | ||
5081 | return ret; | |
5082 | } | |
5083 | ||
38de93ab TZ |
5084 | /* |
5085 | * Currently we only unregister ftrace commands from __init, so mark | |
5086 | * this __init too. | |
5087 | */ | |
5088 | __init int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
5089 | { |
5090 | struct ftrace_func_command *p, *n; | |
5091 | int ret = -ENODEV; | |
5092 | ||
5093 | mutex_lock(&ftrace_cmd_mutex); | |
5094 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
5095 | if (strcmp(cmd->name, p->name) == 0) { | |
5096 | ret = 0; | |
5097 | list_del_init(&p->list); | |
5098 | goto out_unlock; | |
5099 | } | |
5100 | } | |
5101 | out_unlock: | |
5102 | mutex_unlock(&ftrace_cmd_mutex); | |
5103 | ||
5104 | return ret; | |
5105 | } | |
5106 | ||
04ec7bb6 | 5107 | static int ftrace_process_regex(struct ftrace_iterator *iter, |
33dc9b12 | 5108 | char *buff, int len, int enable) |
64e7c440 | 5109 | { |
04ec7bb6 | 5110 | struct ftrace_hash *hash = iter->hash; |
d2afd57a | 5111 | struct trace_array *tr = iter->ops->private; |
f6180773 | 5112 | char *func, *command, *next = buff; |
6a24a244 | 5113 | struct ftrace_func_command *p; |
0aff1c0c | 5114 | int ret = -EINVAL; |
64e7c440 SR |
5115 | |
5116 | func = strsep(&next, ":"); | |
5117 | ||
5118 | if (!next) { | |
1cf41dd7 | 5119 | ret = ftrace_match_records(hash, func, len); |
b448c4e3 SR |
5120 | if (!ret) |
5121 | ret = -EINVAL; | |
5122 | if (ret < 0) | |
5123 | return ret; | |
5124 | return 0; | |
64e7c440 SR |
5125 | } |
5126 | ||
f6180773 | 5127 | /* command found */ |
64e7c440 SR |
5128 | |
5129 | command = strsep(&next, ":"); | |
5130 | ||
f6180773 SR |
5131 | mutex_lock(&ftrace_cmd_mutex); |
5132 | list_for_each_entry(p, &ftrace_commands, list) { | |
5133 | if (strcmp(p->name, command) == 0) { | |
04ec7bb6 | 5134 | ret = p->func(tr, hash, func, command, next, enable); |
f6180773 SR |
5135 | goto out_unlock; |
5136 | } | |
64e7c440 | 5137 | } |
f6180773 SR |
5138 | out_unlock: |
5139 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 5140 | |
f6180773 | 5141 | return ret; |
64e7c440 SR |
5142 | } |
5143 | ||
e309b41d | 5144 | static ssize_t |
41c52c0d SR |
5145 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
5146 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
5147 | { |
5148 | struct ftrace_iterator *iter; | |
689fd8b6 | 5149 | struct trace_parser *parser; |
5150 | ssize_t ret, read; | |
5072c59f | 5151 | |
4ba7978e | 5152 | if (!cnt) |
5072c59f SR |
5153 | return 0; |
5154 | ||
5072c59f SR |
5155 | if (file->f_mode & FMODE_READ) { |
5156 | struct seq_file *m = file->private_data; | |
5157 | iter = m->private; | |
5158 | } else | |
5159 | iter = file->private_data; | |
5160 | ||
f04f24fb | 5161 | if (unlikely(ftrace_disabled)) |
3f2367ba MH |
5162 | return -ENODEV; |
5163 | ||
5164 | /* iter->hash is a local copy, so we don't need regex_lock */ | |
f04f24fb | 5165 | |
689fd8b6 | 5166 | parser = &iter->parser; |
5167 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 5168 | |
4ba7978e | 5169 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 5170 | !trace_parser_cont(parser)) { |
04ec7bb6 | 5171 | ret = ftrace_process_regex(iter, parser->buffer, |
689fd8b6 | 5172 | parser->idx, enable); |
313254a9 | 5173 | trace_parser_clear(parser); |
7c088b51 | 5174 | if (ret < 0) |
3f2367ba | 5175 | goto out; |
eda1e328 | 5176 | } |
5072c59f | 5177 | |
5072c59f | 5178 | ret = read; |
3f2367ba | 5179 | out: |
5072c59f SR |
5180 | return ret; |
5181 | } | |
5182 | ||
fc13cb0c | 5183 | ssize_t |
41c52c0d SR |
5184 | ftrace_filter_write(struct file *file, const char __user *ubuf, |
5185 | size_t cnt, loff_t *ppos) | |
5186 | { | |
5187 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
5188 | } | |
5189 | ||
fc13cb0c | 5190 | ssize_t |
41c52c0d SR |
5191 | ftrace_notrace_write(struct file *file, const char __user *ubuf, |
5192 | size_t cnt, loff_t *ppos) | |
5193 | { | |
5194 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
5195 | } | |
5196 | ||
33dc9b12 | 5197 | static int |
4f554e95 | 5198 | __ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) |
647664ea MH |
5199 | { |
5200 | struct ftrace_func_entry *entry; | |
5201 | ||
aebfd125 PZ |
5202 | ip = ftrace_location(ip); |
5203 | if (!ip) | |
647664ea MH |
5204 | return -EINVAL; |
5205 | ||
5206 | if (remove) { | |
5207 | entry = ftrace_lookup_ip(hash, ip); | |
5208 | if (!entry) | |
5209 | return -ENOENT; | |
5210 | free_hash_entry(hash, entry); | |
5211 | return 0; | |
5212 | } | |
5213 | ||
5214 | return add_hash_entry(hash, ip); | |
5215 | } | |
5216 | ||
4f554e95 JO |
5217 | static int |
5218 | ftrace_match_addr(struct ftrace_hash *hash, unsigned long *ips, | |
5219 | unsigned int cnt, int remove) | |
5220 | { | |
5221 | unsigned int i; | |
5222 | int err; | |
5223 | ||
5224 | for (i = 0; i < cnt; i++) { | |
5225 | err = __ftrace_match_addr(hash, ips[i], remove); | |
5226 | if (err) { | |
5227 | /* | |
5228 | * This expects the @hash is a temporary hash and if this | |
5229 | * fails the caller must free the @hash. | |
5230 | */ | |
5231 | return err; | |
5232 | } | |
5233 | } | |
5234 | return 0; | |
5235 | } | |
5236 | ||
647664ea MH |
5237 | static int |
5238 | ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, | |
4f554e95 JO |
5239 | unsigned long *ips, unsigned int cnt, |
5240 | int remove, int reset, int enable) | |
41c52c0d | 5241 | { |
33dc9b12 | 5242 | struct ftrace_hash **orig_hash; |
f45948e8 | 5243 | struct ftrace_hash *hash; |
33dc9b12 | 5244 | int ret; |
f45948e8 | 5245 | |
41c52c0d | 5246 | if (unlikely(ftrace_disabled)) |
33dc9b12 | 5247 | return -ENODEV; |
41c52c0d | 5248 | |
33b7f99c | 5249 | mutex_lock(&ops->func_hash->regex_lock); |
3f2367ba | 5250 | |
f45948e8 | 5251 | if (enable) |
33b7f99c | 5252 | orig_hash = &ops->func_hash->filter_hash; |
f45948e8 | 5253 | else |
33b7f99c | 5254 | orig_hash = &ops->func_hash->notrace_hash; |
33dc9b12 | 5255 | |
b972cc58 WN |
5256 | if (reset) |
5257 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); | |
5258 | else | |
5259 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
5260 | ||
3f2367ba MH |
5261 | if (!hash) { |
5262 | ret = -ENOMEM; | |
5263 | goto out_regex_unlock; | |
5264 | } | |
f45948e8 | 5265 | |
ac483c44 JO |
5266 | if (buf && !ftrace_match_records(hash, buf, len)) { |
5267 | ret = -EINVAL; | |
5268 | goto out_regex_unlock; | |
5269 | } | |
4f554e95 JO |
5270 | if (ips) { |
5271 | ret = ftrace_match_addr(hash, ips, cnt, remove); | |
647664ea MH |
5272 | if (ret < 0) |
5273 | goto out_regex_unlock; | |
5274 | } | |
33dc9b12 SR |
5275 | |
5276 | mutex_lock(&ftrace_lock); | |
e16b35dd | 5277 | ret = ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable); |
33dc9b12 SR |
5278 | mutex_unlock(&ftrace_lock); |
5279 | ||
ac483c44 | 5280 | out_regex_unlock: |
33b7f99c | 5281 | mutex_unlock(&ops->func_hash->regex_lock); |
33dc9b12 SR |
5282 | |
5283 | free_ftrace_hash(hash); | |
5284 | return ret; | |
41c52c0d SR |
5285 | } |
5286 | ||
647664ea | 5287 | static int |
4f554e95 JO |
5288 | ftrace_set_addr(struct ftrace_ops *ops, unsigned long *ips, unsigned int cnt, |
5289 | int remove, int reset, int enable) | |
647664ea | 5290 | { |
4f554e95 | 5291 | return ftrace_set_hash(ops, NULL, 0, ips, cnt, remove, reset, enable); |
647664ea MH |
5292 | } |
5293 | ||
763e34e7 | 5294 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS |
013bf0da SRV |
5295 | |
5296 | struct ftrace_direct_func { | |
5297 | struct list_head next; | |
5298 | unsigned long addr; | |
5299 | int count; | |
5300 | }; | |
5301 | ||
5302 | static LIST_HEAD(ftrace_direct_funcs); | |
5303 | ||
5304 | /** | |
5305 | * ftrace_find_direct_func - test an address if it is a registered direct caller | |
5306 | * @addr: The address of a registered direct caller | |
5307 | * | |
5308 | * This searches to see if a ftrace direct caller has been registered | |
5309 | * at a specific address, and if so, it returns a descriptor for it. | |
5310 | * | |
5311 | * This can be used by architecture code to see if an address is | |
5312 | * a direct caller (trampoline) attached to a fentry/mcount location. | |
5313 | * This is useful for the function_graph tracer, as it may need to | |
5314 | * do adjustments if it traced a location that also has a direct | |
5315 | * trampoline attached to it. | |
5316 | */ | |
5317 | struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr) | |
5318 | { | |
5319 | struct ftrace_direct_func *entry; | |
5320 | bool found = false; | |
5321 | ||
5322 | /* May be called by fgraph trampoline (protected by rcu tasks) */ | |
5323 | list_for_each_entry_rcu(entry, &ftrace_direct_funcs, next) { | |
5324 | if (entry->addr == addr) { | |
5325 | found = true; | |
5326 | break; | |
5327 | } | |
5328 | } | |
5329 | if (found) | |
5330 | return entry; | |
5331 | ||
5332 | return NULL; | |
5333 | } | |
5334 | ||
8a141dd7 AS |
5335 | static struct ftrace_direct_func *ftrace_alloc_direct_func(unsigned long addr) |
5336 | { | |
5337 | struct ftrace_direct_func *direct; | |
5338 | ||
5339 | direct = kmalloc(sizeof(*direct), GFP_KERNEL); | |
5340 | if (!direct) | |
5341 | return NULL; | |
5342 | direct->addr = addr; | |
5343 | direct->count = 0; | |
5344 | list_add_rcu(&direct->next, &ftrace_direct_funcs); | |
5345 | ftrace_direct_func_count++; | |
5346 | return direct; | |
5347 | } | |
5348 | ||
53cd885b SL |
5349 | static int register_ftrace_function_nolock(struct ftrace_ops *ops); |
5350 | ||
763e34e7 SRV |
5351 | /** |
5352 | * register_ftrace_direct - Call a custom trampoline directly | |
5353 | * @ip: The address of the nop at the beginning of a function | |
5354 | * @addr: The address of the trampoline to call at @ip | |
5355 | * | |
5356 | * This is used to connect a direct call from the nop location (@ip) | |
5357 | * at the start of ftrace traced functions. The location that it calls | |
5358 | * (@addr) must be able to handle a direct call, and save the parameters | |
5359 | * of the function being traced, and restore them (or inject new ones | |
5360 | * if needed), before returning. | |
5361 | * | |
5362 | * Returns: | |
5363 | * 0 on success | |
5364 | * -EBUSY - Another direct function is already attached (there can be only one) | |
5365 | * -ENODEV - @ip does not point to a ftrace nop location (or not supported) | |
5366 | * -ENOMEM - There was an allocation failure. | |
5367 | */ | |
5368 | int register_ftrace_direct(unsigned long ip, unsigned long addr) | |
5369 | { | |
013bf0da | 5370 | struct ftrace_direct_func *direct; |
763e34e7 SRV |
5371 | struct ftrace_func_entry *entry; |
5372 | struct ftrace_hash *free_hash = NULL; | |
5373 | struct dyn_ftrace *rec; | |
aebfd125 | 5374 | int ret = -ENODEV; |
763e34e7 SRV |
5375 | |
5376 | mutex_lock(&direct_mutex); | |
5377 | ||
aebfd125 PZ |
5378 | ip = ftrace_location(ip); |
5379 | if (!ip) | |
5380 | goto out_unlock; | |
5381 | ||
763e34e7 | 5382 | /* See if there's a direct function at @ip already */ |
aebfd125 | 5383 | ret = -EBUSY; |
ff205766 | 5384 | if (ftrace_find_rec_direct(ip)) |
763e34e7 SRV |
5385 | goto out_unlock; |
5386 | ||
5387 | ret = -ENODEV; | |
5388 | rec = lookup_rec(ip, ip); | |
5389 | if (!rec) | |
5390 | goto out_unlock; | |
5391 | ||
5392 | /* | |
5393 | * Check if the rec says it has a direct call but we didn't | |
5394 | * find one earlier? | |
5395 | */ | |
5396 | if (WARN_ON(rec->flags & FTRACE_FL_DIRECT)) | |
5397 | goto out_unlock; | |
5398 | ||
5399 | /* Make sure the ip points to the exact record */ | |
406acdd3 SRV |
5400 | if (ip != rec->ip) { |
5401 | ip = rec->ip; | |
5402 | /* Need to check this ip for a direct. */ | |
ff205766 | 5403 | if (ftrace_find_rec_direct(ip)) |
406acdd3 SRV |
5404 | goto out_unlock; |
5405 | } | |
763e34e7 SRV |
5406 | |
5407 | ret = -ENOMEM; | |
013bf0da SRV |
5408 | direct = ftrace_find_direct_func(addr); |
5409 | if (!direct) { | |
8a141dd7 | 5410 | direct = ftrace_alloc_direct_func(addr); |
1904a814 | 5411 | if (!direct) |
013bf0da | 5412 | goto out_unlock; |
013bf0da SRV |
5413 | } |
5414 | ||
1904a814 JO |
5415 | entry = ftrace_add_rec_direct(ip, addr, &free_hash); |
5416 | if (!entry) | |
5417 | goto out_unlock; | |
763e34e7 SRV |
5418 | |
5419 | ret = ftrace_set_filter_ip(&direct_ops, ip, 0, 0); | |
763e34e7 SRV |
5420 | |
5421 | if (!ret && !(direct_ops.flags & FTRACE_OPS_FL_ENABLED)) { | |
53cd885b | 5422 | ret = register_ftrace_function_nolock(&direct_ops); |
763e34e7 SRV |
5423 | if (ret) |
5424 | ftrace_set_filter_ip(&direct_ops, ip, 1, 0); | |
5425 | } | |
5426 | ||
013bf0da | 5427 | if (ret) { |
7d54c15c | 5428 | remove_hash_entry(direct_functions, entry); |
763e34e7 | 5429 | kfree(entry); |
013bf0da SRV |
5430 | if (!direct->count) { |
5431 | list_del_rcu(&direct->next); | |
5432 | synchronize_rcu_tasks(); | |
5433 | kfree(direct); | |
5434 | if (free_hash) | |
5435 | free_ftrace_hash(free_hash); | |
5436 | free_hash = NULL; | |
a3ad1a7e | 5437 | ftrace_direct_func_count--; |
013bf0da SRV |
5438 | } |
5439 | } else { | |
1c7f9b67 | 5440 | direct->count++; |
013bf0da | 5441 | } |
763e34e7 SRV |
5442 | out_unlock: |
5443 | mutex_unlock(&direct_mutex); | |
5444 | ||
5445 | if (free_hash) { | |
5446 | synchronize_rcu_tasks(); | |
5447 | free_ftrace_hash(free_hash); | |
5448 | } | |
5449 | ||
5450 | return ret; | |
5451 | } | |
5452 | EXPORT_SYMBOL_GPL(register_ftrace_direct); | |
5453 | ||
ea806eb3 SRV |
5454 | static struct ftrace_func_entry *find_direct_entry(unsigned long *ip, |
5455 | struct dyn_ftrace **recp) | |
763e34e7 SRV |
5456 | { |
5457 | struct ftrace_func_entry *entry; | |
5458 | struct dyn_ftrace *rec; | |
763e34e7 | 5459 | |
128161f4 SRV |
5460 | rec = lookup_rec(*ip, *ip); |
5461 | if (!rec) | |
5462 | return NULL; | |
763e34e7 | 5463 | |
128161f4 | 5464 | entry = __ftrace_lookup_ip(direct_functions, rec->ip); |
763e34e7 | 5465 | if (!entry) { |
128161f4 SRV |
5466 | WARN_ON(rec->flags & FTRACE_FL_DIRECT); |
5467 | return NULL; | |
5468 | } | |
763e34e7 | 5469 | |
128161f4 | 5470 | WARN_ON(!(rec->flags & FTRACE_FL_DIRECT)); |
763e34e7 | 5471 | |
128161f4 SRV |
5472 | /* Passed in ip just needs to be on the call site */ |
5473 | *ip = rec->ip; | |
5474 | ||
ea806eb3 SRV |
5475 | if (recp) |
5476 | *recp = rec; | |
5477 | ||
128161f4 SRV |
5478 | return entry; |
5479 | } | |
5480 | ||
5481 | int unregister_ftrace_direct(unsigned long ip, unsigned long addr) | |
5482 | { | |
5483 | struct ftrace_direct_func *direct; | |
5484 | struct ftrace_func_entry *entry; | |
7d5b7cad | 5485 | struct ftrace_hash *hash; |
128161f4 SRV |
5486 | int ret = -ENODEV; |
5487 | ||
5488 | mutex_lock(&direct_mutex); | |
5489 | ||
aebfd125 PZ |
5490 | ip = ftrace_location(ip); |
5491 | if (!ip) | |
5492 | goto out_unlock; | |
5493 | ||
ea806eb3 | 5494 | entry = find_direct_entry(&ip, NULL); |
128161f4 SRV |
5495 | if (!entry) |
5496 | goto out_unlock; | |
763e34e7 | 5497 | |
7d5b7cad JO |
5498 | hash = direct_ops.func_hash->filter_hash; |
5499 | if (hash->count == 1) | |
763e34e7 SRV |
5500 | unregister_ftrace_function(&direct_ops); |
5501 | ||
5502 | ret = ftrace_set_filter_ip(&direct_ops, ip, 1, 0); | |
5503 | ||
5504 | WARN_ON(ret); | |
5505 | ||
5506 | remove_hash_entry(direct_functions, entry); | |
5507 | ||
013bf0da SRV |
5508 | direct = ftrace_find_direct_func(addr); |
5509 | if (!WARN_ON(!direct)) { | |
5510 | /* This is the good path (see the ! before WARN) */ | |
5511 | direct->count--; | |
5512 | WARN_ON(direct->count < 0); | |
5513 | if (!direct->count) { | |
5514 | list_del_rcu(&direct->next); | |
5515 | synchronize_rcu_tasks(); | |
5516 | kfree(direct); | |
353da879 | 5517 | kfree(entry); |
a3ad1a7e | 5518 | ftrace_direct_func_count--; |
013bf0da SRV |
5519 | } |
5520 | } | |
763e34e7 SRV |
5521 | out_unlock: |
5522 | mutex_unlock(&direct_mutex); | |
5523 | ||
5524 | return ret; | |
5525 | } | |
5526 | EXPORT_SYMBOL_GPL(unregister_ftrace_direct); | |
0567d680 SRV |
5527 | |
5528 | static struct ftrace_ops stub_ops = { | |
5529 | .func = ftrace_stub, | |
5530 | }; | |
5531 | ||
ea806eb3 SRV |
5532 | /** |
5533 | * ftrace_modify_direct_caller - modify ftrace nop directly | |
5534 | * @entry: The ftrace hash entry of the direct helper for @rec | |
5535 | * @rec: The record representing the function site to patch | |
5536 | * @old_addr: The location that the site at @rec->ip currently calls | |
5537 | * @new_addr: The location that the site at @rec->ip should call | |
5538 | * | |
5539 | * An architecture may overwrite this function to optimize the | |
5540 | * changing of the direct callback on an ftrace nop location. | |
5541 | * This is called with the ftrace_lock mutex held, and no other | |
5542 | * ftrace callbacks are on the associated record (@rec). Thus, | |
5543 | * it is safe to modify the ftrace record, where it should be | |
5544 | * currently calling @old_addr directly, to call @new_addr. | |
5545 | * | |
9d2ce78d SL |
5546 | * This is called with direct_mutex locked. |
5547 | * | |
ea806eb3 SRV |
5548 | * Safety checks should be made to make sure that the code at |
5549 | * @rec->ip is currently calling @old_addr. And this must | |
5550 | * also update entry->direct to @new_addr. | |
5551 | */ | |
5552 | int __weak ftrace_modify_direct_caller(struct ftrace_func_entry *entry, | |
5553 | struct dyn_ftrace *rec, | |
5554 | unsigned long old_addr, | |
5555 | unsigned long new_addr) | |
5556 | { | |
5557 | unsigned long ip = rec->ip; | |
5558 | int ret; | |
5559 | ||
9d2ce78d SL |
5560 | lockdep_assert_held(&direct_mutex); |
5561 | ||
ea806eb3 SRV |
5562 | /* |
5563 | * The ftrace_lock was used to determine if the record | |
5564 | * had more than one registered user to it. If it did, | |
5565 | * we needed to prevent that from changing to do the quick | |
5566 | * switch. But if it did not (only a direct caller was attached) | |
5567 | * then this function is called. But this function can deal | |
5568 | * with attached callers to the rec that we care about, and | |
5569 | * since this function uses standard ftrace calls that take | |
5570 | * the ftrace_lock mutex, we need to release it. | |
5571 | */ | |
5572 | mutex_unlock(&ftrace_lock); | |
5573 | ||
5574 | /* | |
5575 | * By setting a stub function at the same address, we force | |
5576 | * the code to call the iterator and the direct_ops helper. | |
5577 | * This means that @ip does not call the direct call, and | |
5578 | * we can simply modify it. | |
5579 | */ | |
5580 | ret = ftrace_set_filter_ip(&stub_ops, ip, 0, 0); | |
5581 | if (ret) | |
5582 | goto out_lock; | |
5583 | ||
9d2ce78d | 5584 | ret = register_ftrace_function_nolock(&stub_ops); |
ea806eb3 SRV |
5585 | if (ret) { |
5586 | ftrace_set_filter_ip(&stub_ops, ip, 1, 0); | |
5587 | goto out_lock; | |
5588 | } | |
5589 | ||
5590 | entry->direct = new_addr; | |
5591 | ||
5592 | /* | |
5593 | * By removing the stub, we put back the direct call, calling | |
5594 | * the @new_addr. | |
5595 | */ | |
5596 | unregister_ftrace_function(&stub_ops); | |
5597 | ftrace_set_filter_ip(&stub_ops, ip, 1, 0); | |
5598 | ||
5599 | out_lock: | |
5600 | mutex_lock(&ftrace_lock); | |
5601 | ||
5602 | return ret; | |
5603 | } | |
5604 | ||
0567d680 SRV |
5605 | /** |
5606 | * modify_ftrace_direct - Modify an existing direct call to call something else | |
5607 | * @ip: The instruction pointer to modify | |
5608 | * @old_addr: The address that the current @ip calls directly | |
5609 | * @new_addr: The address that the @ip should call | |
5610 | * | |
5611 | * This modifies a ftrace direct caller at an instruction pointer without | |
5612 | * having to disable it first. The direct call will switch over to the | |
5613 | * @new_addr without missing anything. | |
5614 | * | |
5615 | * Returns: zero on success. Non zero on error, which includes: | |
5616 | * -ENODEV : the @ip given has no direct caller attached | |
5617 | * -EINVAL : the @old_addr does not match the current direct caller | |
5618 | */ | |
5619 | int modify_ftrace_direct(unsigned long ip, | |
5620 | unsigned long old_addr, unsigned long new_addr) | |
5621 | { | |
8a141dd7 | 5622 | struct ftrace_direct_func *direct, *new_direct = NULL; |
0567d680 | 5623 | struct ftrace_func_entry *entry; |
ea806eb3 | 5624 | struct dyn_ftrace *rec; |
0567d680 SRV |
5625 | int ret = -ENODEV; |
5626 | ||
5627 | mutex_lock(&direct_mutex); | |
0567d680 | 5628 | |
ea806eb3 | 5629 | mutex_lock(&ftrace_lock); |
aebfd125 PZ |
5630 | |
5631 | ip = ftrace_location(ip); | |
5632 | if (!ip) | |
5633 | goto out_unlock; | |
5634 | ||
ea806eb3 | 5635 | entry = find_direct_entry(&ip, &rec); |
128161f4 SRV |
5636 | if (!entry) |
5637 | goto out_unlock; | |
0567d680 SRV |
5638 | |
5639 | ret = -EINVAL; | |
5640 | if (entry->direct != old_addr) | |
5641 | goto out_unlock; | |
5642 | ||
8a141dd7 AS |
5643 | direct = ftrace_find_direct_func(old_addr); |
5644 | if (WARN_ON(!direct)) | |
5645 | goto out_unlock; | |
5646 | if (direct->count > 1) { | |
5647 | ret = -ENOMEM; | |
5648 | new_direct = ftrace_alloc_direct_func(new_addr); | |
5649 | if (!new_direct) | |
5650 | goto out_unlock; | |
5651 | direct->count--; | |
5652 | new_direct->count++; | |
5653 | } else { | |
5654 | direct->addr = new_addr; | |
5655 | } | |
5656 | ||
0567d680 | 5657 | /* |
ea806eb3 SRV |
5658 | * If there's no other ftrace callback on the rec->ip location, |
5659 | * then it can be changed directly by the architecture. | |
5660 | * If there is another caller, then we just need to change the | |
5661 | * direct caller helper to point to @new_addr. | |
0567d680 | 5662 | */ |
ea806eb3 SRV |
5663 | if (ftrace_rec_count(rec) == 1) { |
5664 | ret = ftrace_modify_direct_caller(entry, rec, old_addr, new_addr); | |
5665 | } else { | |
5666 | entry->direct = new_addr; | |
5667 | ret = 0; | |
0567d680 SRV |
5668 | } |
5669 | ||
2a2d8c51 ZY |
5670 | if (ret) { |
5671 | direct->addr = old_addr; | |
5672 | if (unlikely(new_direct)) { | |
5673 | direct->count++; | |
5674 | list_del_rcu(&new_direct->next); | |
5675 | synchronize_rcu_tasks(); | |
5676 | kfree(new_direct); | |
5677 | ftrace_direct_func_count--; | |
5678 | } | |
8a141dd7 AS |
5679 | } |
5680 | ||
0567d680 | 5681 | out_unlock: |
ea806eb3 | 5682 | mutex_unlock(&ftrace_lock); |
0567d680 SRV |
5683 | mutex_unlock(&direct_mutex); |
5684 | return ret; | |
5685 | } | |
5686 | EXPORT_SYMBOL_GPL(modify_ftrace_direct); | |
f64dd462 | 5687 | |
53cd885b | 5688 | #define MULTI_FLAGS (FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_REGS) |
f64dd462 JO |
5689 | |
5690 | static int check_direct_multi(struct ftrace_ops *ops) | |
5691 | { | |
5692 | if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) | |
5693 | return -EINVAL; | |
5694 | if ((ops->flags & MULTI_FLAGS) != MULTI_FLAGS) | |
5695 | return -EINVAL; | |
5696 | return 0; | |
5697 | } | |
5698 | ||
5699 | static void remove_direct_functions_hash(struct ftrace_hash *hash, unsigned long addr) | |
5700 | { | |
5701 | struct ftrace_func_entry *entry, *del; | |
5702 | int size, i; | |
5703 | ||
5704 | size = 1 << hash->size_bits; | |
5705 | for (i = 0; i < size; i++) { | |
5706 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
5707 | del = __ftrace_lookup_ip(direct_functions, entry->ip); | |
5708 | if (del && del->direct == addr) { | |
5709 | remove_hash_entry(direct_functions, del); | |
5710 | kfree(del); | |
5711 | } | |
5712 | } | |
5713 | } | |
5714 | } | |
5715 | ||
5716 | /** | |
5717 | * register_ftrace_direct_multi - Call a custom trampoline directly | |
5718 | * for multiple functions registered in @ops | |
5719 | * @ops: The address of the struct ftrace_ops object | |
5720 | * @addr: The address of the trampoline to call at @ops functions | |
5721 | * | |
5722 | * This is used to connect a direct calls to @addr from the nop locations | |
5723 | * of the functions registered in @ops (with by ftrace_set_filter_ip | |
5724 | * function). | |
5725 | * | |
5726 | * The location that it calls (@addr) must be able to handle a direct call, | |
5727 | * and save the parameters of the function being traced, and restore them | |
5728 | * (or inject new ones if needed), before returning. | |
5729 | * | |
5730 | * Returns: | |
5731 | * 0 on success | |
5732 | * -EINVAL - The @ops object was already registered with this call or | |
5733 | * when there are no functions in @ops object. | |
5734 | * -EBUSY - Another direct function is already attached (there can be only one) | |
5735 | * -ENODEV - @ip does not point to a ftrace nop location (or not supported) | |
5736 | * -ENOMEM - There was an allocation failure. | |
5737 | */ | |
5738 | int register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) | |
5739 | { | |
5740 | struct ftrace_hash *hash, *free_hash = NULL; | |
5741 | struct ftrace_func_entry *entry, *new; | |
5742 | int err = -EBUSY, size, i; | |
5743 | ||
5744 | if (ops->func || ops->trampoline) | |
5745 | return -EINVAL; | |
5746 | if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) | |
5747 | return -EINVAL; | |
5748 | if (ops->flags & FTRACE_OPS_FL_ENABLED) | |
5749 | return -EINVAL; | |
5750 | ||
5751 | hash = ops->func_hash->filter_hash; | |
5752 | if (ftrace_hash_empty(hash)) | |
5753 | return -EINVAL; | |
5754 | ||
5755 | mutex_lock(&direct_mutex); | |
5756 | ||
5757 | /* Make sure requested entries are not already registered.. */ | |
5758 | size = 1 << hash->size_bits; | |
5759 | for (i = 0; i < size; i++) { | |
5760 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
5761 | if (ftrace_find_rec_direct(entry->ip)) | |
5762 | goto out_unlock; | |
5763 | } | |
5764 | } | |
5765 | ||
5766 | /* ... and insert them to direct_functions hash. */ | |
5767 | err = -ENOMEM; | |
5768 | for (i = 0; i < size; i++) { | |
5769 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
5770 | new = ftrace_add_rec_direct(entry->ip, addr, &free_hash); | |
5771 | if (!new) | |
5772 | goto out_remove; | |
5773 | entry->direct = addr; | |
5774 | } | |
5775 | } | |
5776 | ||
5777 | ops->func = call_direct_funcs; | |
5778 | ops->flags = MULTI_FLAGS; | |
5779 | ops->trampoline = FTRACE_REGS_ADDR; | |
5780 | ||
53cd885b | 5781 | err = register_ftrace_function_nolock(ops); |
f64dd462 JO |
5782 | |
5783 | out_remove: | |
5784 | if (err) | |
5785 | remove_direct_functions_hash(hash, addr); | |
5786 | ||
5787 | out_unlock: | |
5788 | mutex_unlock(&direct_mutex); | |
5789 | ||
5790 | if (free_hash) { | |
5791 | synchronize_rcu_tasks(); | |
5792 | free_ftrace_hash(free_hash); | |
5793 | } | |
5794 | return err; | |
5795 | } | |
5796 | EXPORT_SYMBOL_GPL(register_ftrace_direct_multi); | |
5797 | ||
5798 | /** | |
5799 | * unregister_ftrace_direct_multi - Remove calls to custom trampoline | |
5800 | * previously registered by register_ftrace_direct_multi for @ops object. | |
5801 | * @ops: The address of the struct ftrace_ops object | |
5802 | * | |
5803 | * This is used to remove a direct calls to @addr from the nop locations | |
5804 | * of the functions registered in @ops (with by ftrace_set_filter_ip | |
5805 | * function). | |
5806 | * | |
5807 | * Returns: | |
5808 | * 0 on success | |
5809 | * -EINVAL - The @ops object was not properly registered. | |
5810 | */ | |
5811 | int unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) | |
5812 | { | |
5813 | struct ftrace_hash *hash = ops->func_hash->filter_hash; | |
5814 | int err; | |
5815 | ||
5816 | if (check_direct_multi(ops)) | |
5817 | return -EINVAL; | |
5818 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
5819 | return -EINVAL; | |
5820 | ||
5821 | mutex_lock(&direct_mutex); | |
5822 | err = unregister_ftrace_function(ops); | |
5823 | remove_direct_functions_hash(hash, addr); | |
5824 | mutex_unlock(&direct_mutex); | |
fea3ffa4 JO |
5825 | |
5826 | /* cleanup for possible another register call */ | |
5827 | ops->func = NULL; | |
5828 | ops->trampoline = 0; | |
f64dd462 JO |
5829 | return err; |
5830 | } | |
5831 | EXPORT_SYMBOL_GPL(unregister_ftrace_direct_multi); | |
ccf5a89e | 5832 | |
f96f644a SL |
5833 | static int |
5834 | __modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) | |
ccf5a89e | 5835 | { |
ed292718 | 5836 | struct ftrace_hash *hash; |
ccf5a89e | 5837 | struct ftrace_func_entry *entry, *iter; |
ed292718 SRV |
5838 | static struct ftrace_ops tmp_ops = { |
5839 | .func = ftrace_stub, | |
5840 | .flags = FTRACE_OPS_FL_STUB, | |
5841 | }; | |
ccf5a89e JO |
5842 | int i, size; |
5843 | int err; | |
5844 | ||
f96f644a | 5845 | lockdep_assert_held_once(&direct_mutex); |
ed292718 SRV |
5846 | |
5847 | /* Enable the tmp_ops to have the same functions as the direct ops */ | |
5848 | ftrace_ops_init(&tmp_ops); | |
5849 | tmp_ops.func_hash = ops->func_hash; | |
5850 | ||
53cd885b | 5851 | err = register_ftrace_function_nolock(&tmp_ops); |
ed292718 | 5852 | if (err) |
f96f644a | 5853 | return err; |
ccf5a89e JO |
5854 | |
5855 | /* | |
ed292718 SRV |
5856 | * Now the ftrace_ops_list_func() is called to do the direct callers. |
5857 | * We can safely change the direct functions attached to each entry. | |
ccf5a89e | 5858 | */ |
ed292718 | 5859 | mutex_lock(&ftrace_lock); |
ccf5a89e | 5860 | |
ed292718 | 5861 | hash = ops->func_hash->filter_hash; |
ccf5a89e JO |
5862 | size = 1 << hash->size_bits; |
5863 | for (i = 0; i < size; i++) { | |
5864 | hlist_for_each_entry(iter, &hash->buckets[i], hlist) { | |
5865 | entry = __ftrace_lookup_ip(direct_functions, iter->ip); | |
5866 | if (!entry) | |
5867 | continue; | |
5868 | entry->direct = addr; | |
5869 | } | |
5870 | } | |
5871 | ||
2e6e9058 JO |
5872 | mutex_unlock(&ftrace_lock); |
5873 | ||
ed292718 SRV |
5874 | /* Removing the tmp_ops will add the updated direct callers to the functions */ |
5875 | unregister_ftrace_function(&tmp_ops); | |
ccf5a89e | 5876 | |
f96f644a SL |
5877 | return err; |
5878 | } | |
5879 | ||
5880 | /** | |
5881 | * modify_ftrace_direct_multi_nolock - Modify an existing direct 'multi' call | |
5882 | * to call something else | |
5883 | * @ops: The address of the struct ftrace_ops object | |
5884 | * @addr: The address of the new trampoline to call at @ops functions | |
5885 | * | |
5886 | * This is used to unregister currently registered direct caller and | |
5887 | * register new one @addr on functions registered in @ops object. | |
5888 | * | |
5889 | * Note there's window between ftrace_shutdown and ftrace_startup calls | |
5890 | * where there will be no callbacks called. | |
5891 | * | |
5892 | * Caller should already have direct_mutex locked, so we don't lock | |
5893 | * direct_mutex here. | |
5894 | * | |
5895 | * Returns: zero on success. Non zero on error, which includes: | |
5896 | * -EINVAL - The @ops object was not properly registered. | |
5897 | */ | |
5898 | int modify_ftrace_direct_multi_nolock(struct ftrace_ops *ops, unsigned long addr) | |
5899 | { | |
5900 | if (check_direct_multi(ops)) | |
5901 | return -EINVAL; | |
5902 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
5903 | return -EINVAL; | |
5904 | ||
5905 | return __modify_ftrace_direct_multi(ops, addr); | |
5906 | } | |
5907 | EXPORT_SYMBOL_GPL(modify_ftrace_direct_multi_nolock); | |
5908 | ||
5909 | /** | |
5910 | * modify_ftrace_direct_multi - Modify an existing direct 'multi' call | |
5911 | * to call something else | |
5912 | * @ops: The address of the struct ftrace_ops object | |
5913 | * @addr: The address of the new trampoline to call at @ops functions | |
5914 | * | |
5915 | * This is used to unregister currently registered direct caller and | |
5916 | * register new one @addr on functions registered in @ops object. | |
5917 | * | |
5918 | * Note there's window between ftrace_shutdown and ftrace_startup calls | |
5919 | * where there will be no callbacks called. | |
5920 | * | |
5921 | * Returns: zero on success. Non zero on error, which includes: | |
5922 | * -EINVAL - The @ops object was not properly registered. | |
5923 | */ | |
5924 | int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) | |
5925 | { | |
5926 | int err; | |
5927 | ||
5928 | if (check_direct_multi(ops)) | |
5929 | return -EINVAL; | |
5930 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
5931 | return -EINVAL; | |
5932 | ||
5933 | mutex_lock(&direct_mutex); | |
5934 | err = __modify_ftrace_direct_multi(ops, addr); | |
ccf5a89e JO |
5935 | mutex_unlock(&direct_mutex); |
5936 | return err; | |
5937 | } | |
5938 | EXPORT_SYMBOL_GPL(modify_ftrace_direct_multi); | |
763e34e7 SRV |
5939 | #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ |
5940 | ||
647664ea MH |
5941 | /** |
5942 | * ftrace_set_filter_ip - set a function to filter on in ftrace by address | |
5943 | * @ops - the ops to set the filter with | |
5944 | * @ip - the address to add to or remove from the filter. | |
5945 | * @remove - non zero to remove the ip from the filter | |
5946 | * @reset - non zero to reset all filters before applying this filter. | |
5947 | * | |
5948 | * Filters denote which functions should be enabled when tracing is enabled | |
f2cc020d | 5949 | * If @ip is NULL, it fails to update filter. |
8be9fbd5 MR |
5950 | * |
5951 | * This can allocate memory which must be freed before @ops can be freed, | |
5952 | * either by removing each filtered addr or by using | |
5953 | * ftrace_free_filter(@ops). | |
647664ea MH |
5954 | */ |
5955 | int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, | |
5956 | int remove, int reset) | |
5957 | { | |
f04f24fb | 5958 | ftrace_ops_init(ops); |
4f554e95 | 5959 | return ftrace_set_addr(ops, &ip, 1, remove, reset, 1); |
647664ea MH |
5960 | } |
5961 | EXPORT_SYMBOL_GPL(ftrace_set_filter_ip); | |
5962 | ||
4f554e95 JO |
5963 | /** |
5964 | * ftrace_set_filter_ips - set functions to filter on in ftrace by addresses | |
5965 | * @ops - the ops to set the filter with | |
5966 | * @ips - the array of addresses to add to or remove from the filter. | |
5967 | * @cnt - the number of addresses in @ips | |
5968 | * @remove - non zero to remove ips from the filter | |
5969 | * @reset - non zero to reset all filters before applying this filter. | |
5970 | * | |
5971 | * Filters denote which functions should be enabled when tracing is enabled | |
5972 | * If @ips array or any ip specified within is NULL , it fails to update filter. | |
8be9fbd5 MR |
5973 | * |
5974 | * This can allocate memory which must be freed before @ops can be freed, | |
5975 | * either by removing each filtered addr or by using | |
5976 | * ftrace_free_filter(@ops). | |
5977 | */ | |
4f554e95 JO |
5978 | int ftrace_set_filter_ips(struct ftrace_ops *ops, unsigned long *ips, |
5979 | unsigned int cnt, int remove, int reset) | |
5980 | { | |
5981 | ftrace_ops_init(ops); | |
5982 | return ftrace_set_addr(ops, ips, cnt, remove, reset, 1); | |
5983 | } | |
5984 | EXPORT_SYMBOL_GPL(ftrace_set_filter_ips); | |
5985 | ||
d032ae89 JF |
5986 | /** |
5987 | * ftrace_ops_set_global_filter - setup ops to use global filters | |
5988 | * @ops - the ops which will use the global filters | |
5989 | * | |
5990 | * ftrace users who need global function trace filtering should call this. | |
5991 | * It can set the global filter only if ops were not initialized before. | |
5992 | */ | |
5993 | void ftrace_ops_set_global_filter(struct ftrace_ops *ops) | |
5994 | { | |
5995 | if (ops->flags & FTRACE_OPS_FL_INITIALIZED) | |
5996 | return; | |
5997 | ||
5998 | ftrace_ops_init(ops); | |
5999 | ops->func_hash = &global_ops.local_hash; | |
6000 | } | |
6001 | EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter); | |
6002 | ||
647664ea MH |
6003 | static int |
6004 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, | |
6005 | int reset, int enable) | |
6006 | { | |
4f554e95 | 6007 | return ftrace_set_hash(ops, buf, len, NULL, 0, 0, reset, enable); |
647664ea MH |
6008 | } |
6009 | ||
77a2b37d SR |
6010 | /** |
6011 | * ftrace_set_filter - set a function to filter on in ftrace | |
936e074b SR |
6012 | * @ops - the ops to set the filter with |
6013 | * @buf - the string that holds the function filter text. | |
6014 | * @len - the length of the string. | |
6015 | * @reset - non zero to reset all filters before applying this filter. | |
6016 | * | |
6017 | * Filters denote which functions should be enabled when tracing is enabled. | |
6018 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
8be9fbd5 MR |
6019 | * |
6020 | * This can allocate memory which must be freed before @ops can be freed, | |
6021 | * either by removing each filtered addr or by using | |
6022 | * ftrace_free_filter(@ops). | |
936e074b | 6023 | */ |
ac483c44 | 6024 | int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
6025 | int len, int reset) |
6026 | { | |
f04f24fb | 6027 | ftrace_ops_init(ops); |
ac483c44 | 6028 | return ftrace_set_regex(ops, buf, len, reset, 1); |
936e074b SR |
6029 | } |
6030 | EXPORT_SYMBOL_GPL(ftrace_set_filter); | |
6031 | ||
6032 | /** | |
6033 | * ftrace_set_notrace - set a function to not trace in ftrace | |
6034 | * @ops - the ops to set the notrace filter with | |
6035 | * @buf - the string that holds the function notrace text. | |
6036 | * @len - the length of the string. | |
6037 | * @reset - non zero to reset all filters before applying this filter. | |
6038 | * | |
6039 | * Notrace Filters denote which functions should not be enabled when tracing | |
6040 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
6041 | * for tracing. | |
8be9fbd5 MR |
6042 | * |
6043 | * This can allocate memory which must be freed before @ops can be freed, | |
6044 | * either by removing each filtered addr or by using | |
6045 | * ftrace_free_filter(@ops). | |
936e074b | 6046 | */ |
ac483c44 | 6047 | int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
6048 | int len, int reset) |
6049 | { | |
f04f24fb | 6050 | ftrace_ops_init(ops); |
ac483c44 | 6051 | return ftrace_set_regex(ops, buf, len, reset, 0); |
936e074b SR |
6052 | } |
6053 | EXPORT_SYMBOL_GPL(ftrace_set_notrace); | |
6054 | /** | |
8d1b065d | 6055 | * ftrace_set_global_filter - set a function to filter on with global tracers |
77a2b37d SR |
6056 | * @buf - the string that holds the function filter text. |
6057 | * @len - the length of the string. | |
6058 | * @reset - non zero to reset all filters before applying this filter. | |
6059 | * | |
6060 | * Filters denote which functions should be enabled when tracing is enabled. | |
6061 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
6062 | */ | |
936e074b | 6063 | void ftrace_set_global_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 6064 | { |
f45948e8 | 6065 | ftrace_set_regex(&global_ops, buf, len, reset, 1); |
41c52c0d | 6066 | } |
936e074b | 6067 | EXPORT_SYMBOL_GPL(ftrace_set_global_filter); |
4eebcc81 | 6068 | |
41c52c0d | 6069 | /** |
8d1b065d | 6070 | * ftrace_set_global_notrace - set a function to not trace with global tracers |
41c52c0d SR |
6071 | * @buf - the string that holds the function notrace text. |
6072 | * @len - the length of the string. | |
6073 | * @reset - non zero to reset all filters before applying this filter. | |
6074 | * | |
6075 | * Notrace Filters denote which functions should not be enabled when tracing | |
6076 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
6077 | * for tracing. | |
6078 | */ | |
936e074b | 6079 | void ftrace_set_global_notrace(unsigned char *buf, int len, int reset) |
41c52c0d | 6080 | { |
f45948e8 | 6081 | ftrace_set_regex(&global_ops, buf, len, reset, 0); |
77a2b37d | 6082 | } |
936e074b | 6083 | EXPORT_SYMBOL_GPL(ftrace_set_global_notrace); |
77a2b37d | 6084 | |
2af15d6a SR |
6085 | /* |
6086 | * command line interface to allow users to set filters on boot up. | |
6087 | */ | |
6088 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
6089 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
6090 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
6091 | ||
f1ed7c74 SRRH |
6092 | /* Used by function selftest to not test if filter is set */ |
6093 | bool ftrace_filter_param __initdata; | |
6094 | ||
2af15d6a SR |
6095 | static int __init set_ftrace_notrace(char *str) |
6096 | { | |
f1ed7c74 | 6097 | ftrace_filter_param = true; |
75761cc1 | 6098 | strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
6099 | return 1; |
6100 | } | |
6101 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
6102 | ||
6103 | static int __init set_ftrace_filter(char *str) | |
6104 | { | |
f1ed7c74 | 6105 | ftrace_filter_param = true; |
75761cc1 | 6106 | strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
6107 | return 1; |
6108 | } | |
6109 | __setup("ftrace_filter=", set_ftrace_filter); | |
6110 | ||
369bc18f | 6111 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 6112 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
0d7d9a16 | 6113 | static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata; |
b9b0c831 | 6114 | static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer); |
801c29fd | 6115 | |
369bc18f SA |
6116 | static int __init set_graph_function(char *str) |
6117 | { | |
06f43d66 | 6118 | strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
6119 | return 1; |
6120 | } | |
6121 | __setup("ftrace_graph_filter=", set_graph_function); | |
6122 | ||
0d7d9a16 NK |
6123 | static int __init set_graph_notrace_function(char *str) |
6124 | { | |
6125 | strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE); | |
6126 | return 1; | |
6127 | } | |
6128 | __setup("ftrace_graph_notrace=", set_graph_notrace_function); | |
6129 | ||
65a50c65 TB |
6130 | static int __init set_graph_max_depth_function(char *str) |
6131 | { | |
6132 | if (!str) | |
6133 | return 0; | |
6134 | fgraph_max_depth = simple_strtoul(str, NULL, 0); | |
6135 | return 1; | |
6136 | } | |
6137 | __setup("ftrace_graph_max_depth=", set_graph_max_depth_function); | |
0d7d9a16 NK |
6138 | |
6139 | static void __init set_ftrace_early_graph(char *buf, int enable) | |
369bc18f SA |
6140 | { |
6141 | int ret; | |
6142 | char *func; | |
b9b0c831 | 6143 | struct ftrace_hash *hash; |
0d7d9a16 | 6144 | |
92ad18ec | 6145 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); |
24589e3a | 6146 | if (MEM_FAIL(!hash, "Failed to allocate hash\n")) |
92ad18ec | 6147 | return; |
369bc18f SA |
6148 | |
6149 | while (buf) { | |
6150 | func = strsep(&buf, ","); | |
6151 | /* we allow only one expression at a time */ | |
b9b0c831 | 6152 | ret = ftrace_graph_set_hash(hash, func); |
369bc18f SA |
6153 | if (ret) |
6154 | printk(KERN_DEBUG "ftrace: function %s not " | |
6155 | "traceable\n", func); | |
6156 | } | |
92ad18ec SRV |
6157 | |
6158 | if (enable) | |
6159 | ftrace_graph_hash = hash; | |
6160 | else | |
6161 | ftrace_graph_notrace_hash = hash; | |
369bc18f SA |
6162 | } |
6163 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
6164 | ||
2a85a37f SR |
6165 | void __init |
6166 | ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable) | |
2af15d6a SR |
6167 | { |
6168 | char *func; | |
6169 | ||
f04f24fb MH |
6170 | ftrace_ops_init(ops); |
6171 | ||
2af15d6a SR |
6172 | while (buf) { |
6173 | func = strsep(&buf, ","); | |
f45948e8 | 6174 | ftrace_set_regex(ops, func, strlen(func), 0, enable); |
2af15d6a SR |
6175 | } |
6176 | } | |
6177 | ||
6178 | static void __init set_ftrace_early_filters(void) | |
6179 | { | |
6180 | if (ftrace_filter_buf[0]) | |
2a85a37f | 6181 | ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1); |
2af15d6a | 6182 | if (ftrace_notrace_buf[0]) |
2a85a37f | 6183 | ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0); |
369bc18f SA |
6184 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
6185 | if (ftrace_graph_buf[0]) | |
0d7d9a16 NK |
6186 | set_ftrace_early_graph(ftrace_graph_buf, 1); |
6187 | if (ftrace_graph_notrace_buf[0]) | |
6188 | set_ftrace_early_graph(ftrace_graph_notrace_buf, 0); | |
369bc18f | 6189 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
2af15d6a SR |
6190 | } |
6191 | ||
fc13cb0c | 6192 | int ftrace_regex_release(struct inode *inode, struct file *file) |
5072c59f SR |
6193 | { |
6194 | struct seq_file *m = (struct seq_file *)file->private_data; | |
6195 | struct ftrace_iterator *iter; | |
33dc9b12 | 6196 | struct ftrace_hash **orig_hash; |
689fd8b6 | 6197 | struct trace_parser *parser; |
ed926f9b | 6198 | int filter_hash; |
5072c59f | 6199 | |
5072c59f SR |
6200 | if (file->f_mode & FMODE_READ) { |
6201 | iter = m->private; | |
5072c59f SR |
6202 | seq_release(inode, file); |
6203 | } else | |
6204 | iter = file->private_data; | |
6205 | ||
689fd8b6 | 6206 | parser = &iter->parser; |
6207 | if (trace_parser_loaded(parser)) { | |
8c9af478 SRV |
6208 | int enable = !(iter->flags & FTRACE_ITER_NOTRACE); |
6209 | ||
6210 | ftrace_process_regex(iter, parser->buffer, | |
6211 | parser->idx, enable); | |
5072c59f SR |
6212 | } |
6213 | ||
689fd8b6 | 6214 | trace_parser_put(parser); |
689fd8b6 | 6215 | |
33b7f99c | 6216 | mutex_lock(&iter->ops->func_hash->regex_lock); |
3f2367ba | 6217 | |
058e297d | 6218 | if (file->f_mode & FMODE_WRITE) { |
ed926f9b SR |
6219 | filter_hash = !!(iter->flags & FTRACE_ITER_FILTER); |
6220 | ||
8c08f0d5 | 6221 | if (filter_hash) { |
33b7f99c | 6222 | orig_hash = &iter->ops->func_hash->filter_hash; |
0ce0638e ZY |
6223 | if (iter->tr) { |
6224 | if (list_empty(&iter->tr->mod_trace)) | |
6225 | iter->hash->flags &= ~FTRACE_HASH_FL_MOD; | |
6226 | else | |
6227 | iter->hash->flags |= FTRACE_HASH_FL_MOD; | |
6228 | } | |
8c08f0d5 | 6229 | } else |
33b7f99c | 6230 | orig_hash = &iter->ops->func_hash->notrace_hash; |
33dc9b12 | 6231 | |
058e297d | 6232 | mutex_lock(&ftrace_lock); |
045e269c | 6233 | ftrace_hash_move_and_update_ops(iter->ops, orig_hash, |
e16b35dd | 6234 | iter->hash, filter_hash); |
058e297d | 6235 | mutex_unlock(&ftrace_lock); |
c20489da SRV |
6236 | } else { |
6237 | /* For read only, the hash is the ops hash */ | |
6238 | iter->hash = NULL; | |
058e297d | 6239 | } |
3f2367ba | 6240 | |
33b7f99c | 6241 | mutex_unlock(&iter->ops->func_hash->regex_lock); |
33dc9b12 | 6242 | free_ftrace_hash(iter->hash); |
9ef16693 SRV |
6243 | if (iter->tr) |
6244 | trace_array_put(iter->tr); | |
33dc9b12 | 6245 | kfree(iter); |
058e297d | 6246 | |
5072c59f SR |
6247 | return 0; |
6248 | } | |
6249 | ||
5e2336a0 | 6250 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
6251 | .open = ftrace_avail_open, |
6252 | .read = seq_read, | |
6253 | .llseek = seq_lseek, | |
3be04b47 | 6254 | .release = seq_release_private, |
5072c59f SR |
6255 | }; |
6256 | ||
647bcd03 SR |
6257 | static const struct file_operations ftrace_enabled_fops = { |
6258 | .open = ftrace_enabled_open, | |
6259 | .read = seq_read, | |
6260 | .llseek = seq_lseek, | |
6261 | .release = seq_release_private, | |
6262 | }; | |
6263 | ||
5e2336a0 | 6264 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 6265 | .open = ftrace_filter_open, |
850a80cf | 6266 | .read = seq_read, |
5072c59f | 6267 | .write = ftrace_filter_write, |
098c879e | 6268 | .llseek = tracing_lseek, |
1cf41dd7 | 6269 | .release = ftrace_regex_release, |
5072c59f SR |
6270 | }; |
6271 | ||
5e2336a0 | 6272 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 6273 | .open = ftrace_notrace_open, |
850a80cf | 6274 | .read = seq_read, |
41c52c0d | 6275 | .write = ftrace_notrace_write, |
098c879e | 6276 | .llseek = tracing_lseek, |
1cf41dd7 | 6277 | .release = ftrace_regex_release, |
41c52c0d SR |
6278 | }; |
6279 | ||
ea4e2bc4 SR |
6280 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
6281 | ||
6282 | static DEFINE_MUTEX(graph_lock); | |
6283 | ||
24a9729f | 6284 | struct ftrace_hash __rcu *ftrace_graph_hash = EMPTY_HASH; |
fd0e6852 | 6285 | struct ftrace_hash __rcu *ftrace_graph_notrace_hash = EMPTY_HASH; |
b9b0c831 NK |
6286 | |
6287 | enum graph_filter_type { | |
6288 | GRAPH_FILTER_NOTRACE = 0, | |
6289 | GRAPH_FILTER_FUNCTION, | |
6290 | }; | |
ea4e2bc4 | 6291 | |
555fc781 SRV |
6292 | #define FTRACE_GRAPH_EMPTY ((void *)1) |
6293 | ||
faf982a6 | 6294 | struct ftrace_graph_data { |
e704eff3 SRV |
6295 | struct ftrace_hash *hash; |
6296 | struct ftrace_func_entry *entry; | |
6297 | int idx; /* for hash table iteration */ | |
6298 | enum graph_filter_type type; | |
6299 | struct ftrace_hash *new_hash; | |
6300 | const struct seq_operations *seq_ops; | |
6301 | struct trace_parser parser; | |
faf982a6 NK |
6302 | }; |
6303 | ||
ea4e2bc4 | 6304 | static void * |
85951842 | 6305 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 6306 | { |
faf982a6 | 6307 | struct ftrace_graph_data *fgd = m->private; |
b9b0c831 NK |
6308 | struct ftrace_func_entry *entry = fgd->entry; |
6309 | struct hlist_head *head; | |
6310 | int i, idx = fgd->idx; | |
faf982a6 | 6311 | |
b9b0c831 | 6312 | if (*pos >= fgd->hash->count) |
ea4e2bc4 | 6313 | return NULL; |
b9b0c831 NK |
6314 | |
6315 | if (entry) { | |
6316 | hlist_for_each_entry_continue(entry, hlist) { | |
6317 | fgd->entry = entry; | |
6318 | return entry; | |
6319 | } | |
6320 | ||
6321 | idx++; | |
6322 | } | |
6323 | ||
6324 | for (i = idx; i < 1 << fgd->hash->size_bits; i++) { | |
6325 | head = &fgd->hash->buckets[i]; | |
6326 | hlist_for_each_entry(entry, head, hlist) { | |
6327 | fgd->entry = entry; | |
6328 | fgd->idx = i; | |
6329 | return entry; | |
6330 | } | |
6331 | } | |
6332 | return NULL; | |
85951842 | 6333 | } |
ea4e2bc4 | 6334 | |
85951842 LZ |
6335 | static void * |
6336 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
6337 | { | |
6338 | (*pos)++; | |
6339 | return __g_next(m, pos); | |
ea4e2bc4 SR |
6340 | } |
6341 | ||
6342 | static void *g_start(struct seq_file *m, loff_t *pos) | |
6343 | { | |
faf982a6 NK |
6344 | struct ftrace_graph_data *fgd = m->private; |
6345 | ||
ea4e2bc4 SR |
6346 | mutex_lock(&graph_lock); |
6347 | ||
649b988b SRV |
6348 | if (fgd->type == GRAPH_FILTER_FUNCTION) |
6349 | fgd->hash = rcu_dereference_protected(ftrace_graph_hash, | |
6350 | lockdep_is_held(&graph_lock)); | |
6351 | else | |
6352 | fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash, | |
6353 | lockdep_is_held(&graph_lock)); | |
6354 | ||
f9349a8f | 6355 | /* Nothing, tell g_show to print all functions are enabled */ |
b9b0c831 | 6356 | if (ftrace_hash_empty(fgd->hash) && !*pos) |
555fc781 | 6357 | return FTRACE_GRAPH_EMPTY; |
f9349a8f | 6358 | |
b9b0c831 NK |
6359 | fgd->idx = 0; |
6360 | fgd->entry = NULL; | |
85951842 | 6361 | return __g_next(m, pos); |
ea4e2bc4 SR |
6362 | } |
6363 | ||
6364 | static void g_stop(struct seq_file *m, void *p) | |
6365 | { | |
6366 | mutex_unlock(&graph_lock); | |
6367 | } | |
6368 | ||
6369 | static int g_show(struct seq_file *m, void *v) | |
6370 | { | |
b9b0c831 | 6371 | struct ftrace_func_entry *entry = v; |
ea4e2bc4 | 6372 | |
b9b0c831 | 6373 | if (!entry) |
ea4e2bc4 SR |
6374 | return 0; |
6375 | ||
555fc781 | 6376 | if (entry == FTRACE_GRAPH_EMPTY) { |
280d1429 NK |
6377 | struct ftrace_graph_data *fgd = m->private; |
6378 | ||
b9b0c831 | 6379 | if (fgd->type == GRAPH_FILTER_FUNCTION) |
fa6f0cc7 | 6380 | seq_puts(m, "#### all functions enabled ####\n"); |
280d1429 | 6381 | else |
fa6f0cc7 | 6382 | seq_puts(m, "#### no functions disabled ####\n"); |
f9349a8f FW |
6383 | return 0; |
6384 | } | |
6385 | ||
b9b0c831 | 6386 | seq_printf(m, "%ps\n", (void *)entry->ip); |
ea4e2bc4 SR |
6387 | |
6388 | return 0; | |
6389 | } | |
6390 | ||
88e9d34c | 6391 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
6392 | .start = g_start, |
6393 | .next = g_next, | |
6394 | .stop = g_stop, | |
6395 | .show = g_show, | |
6396 | }; | |
6397 | ||
6398 | static int | |
faf982a6 NK |
6399 | __ftrace_graph_open(struct inode *inode, struct file *file, |
6400 | struct ftrace_graph_data *fgd) | |
ea4e2bc4 | 6401 | { |
17911ff3 | 6402 | int ret; |
b9b0c831 | 6403 | struct ftrace_hash *new_hash = NULL; |
ea4e2bc4 | 6404 | |
17911ff3 SRV |
6405 | ret = security_locked_down(LOCKDOWN_TRACEFS); |
6406 | if (ret) | |
6407 | return ret; | |
6408 | ||
b9b0c831 NK |
6409 | if (file->f_mode & FMODE_WRITE) { |
6410 | const int size_bits = FTRACE_HASH_DEFAULT_BITS; | |
6411 | ||
e704eff3 SRV |
6412 | if (trace_parser_get_init(&fgd->parser, FTRACE_BUFF_MAX)) |
6413 | return -ENOMEM; | |
6414 | ||
b9b0c831 NK |
6415 | if (file->f_flags & O_TRUNC) |
6416 | new_hash = alloc_ftrace_hash(size_bits); | |
6417 | else | |
6418 | new_hash = alloc_and_copy_ftrace_hash(size_bits, | |
6419 | fgd->hash); | |
6420 | if (!new_hash) { | |
6421 | ret = -ENOMEM; | |
6422 | goto out; | |
6423 | } | |
ea4e2bc4 SR |
6424 | } |
6425 | ||
faf982a6 | 6426 | if (file->f_mode & FMODE_READ) { |
b9b0c831 | 6427 | ret = seq_open(file, &ftrace_graph_seq_ops); |
faf982a6 NK |
6428 | if (!ret) { |
6429 | struct seq_file *m = file->private_data; | |
6430 | m->private = fgd; | |
b9b0c831 NK |
6431 | } else { |
6432 | /* Failed */ | |
6433 | free_ftrace_hash(new_hash); | |
6434 | new_hash = NULL; | |
faf982a6 NK |
6435 | } |
6436 | } else | |
6437 | file->private_data = fgd; | |
ea4e2bc4 | 6438 | |
b9b0c831 | 6439 | out: |
e704eff3 SRV |
6440 | if (ret < 0 && file->f_mode & FMODE_WRITE) |
6441 | trace_parser_put(&fgd->parser); | |
6442 | ||
b9b0c831 | 6443 | fgd->new_hash = new_hash; |
649b988b SRV |
6444 | |
6445 | /* | |
6446 | * All uses of fgd->hash must be taken with the graph_lock | |
6447 | * held. The graph_lock is going to be released, so force | |
6448 | * fgd->hash to be reinitialized when it is taken again. | |
6449 | */ | |
6450 | fgd->hash = NULL; | |
6451 | ||
ea4e2bc4 SR |
6452 | return ret; |
6453 | } | |
6454 | ||
faf982a6 NK |
6455 | static int |
6456 | ftrace_graph_open(struct inode *inode, struct file *file) | |
6457 | { | |
6458 | struct ftrace_graph_data *fgd; | |
b9b0c831 | 6459 | int ret; |
faf982a6 NK |
6460 | |
6461 | if (unlikely(ftrace_disabled)) | |
6462 | return -ENODEV; | |
6463 | ||
6464 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
6465 | if (fgd == NULL) | |
6466 | return -ENOMEM; | |
6467 | ||
b9b0c831 NK |
6468 | mutex_lock(&graph_lock); |
6469 | ||
649b988b SRV |
6470 | fgd->hash = rcu_dereference_protected(ftrace_graph_hash, |
6471 | lockdep_is_held(&graph_lock)); | |
b9b0c831 | 6472 | fgd->type = GRAPH_FILTER_FUNCTION; |
faf982a6 NK |
6473 | fgd->seq_ops = &ftrace_graph_seq_ops; |
6474 | ||
b9b0c831 NK |
6475 | ret = __ftrace_graph_open(inode, file, fgd); |
6476 | if (ret < 0) | |
6477 | kfree(fgd); | |
6478 | ||
6479 | mutex_unlock(&graph_lock); | |
6480 | return ret; | |
faf982a6 NK |
6481 | } |
6482 | ||
29ad23b0 NK |
6483 | static int |
6484 | ftrace_graph_notrace_open(struct inode *inode, struct file *file) | |
6485 | { | |
6486 | struct ftrace_graph_data *fgd; | |
b9b0c831 | 6487 | int ret; |
29ad23b0 NK |
6488 | |
6489 | if (unlikely(ftrace_disabled)) | |
6490 | return -ENODEV; | |
6491 | ||
6492 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
6493 | if (fgd == NULL) | |
6494 | return -ENOMEM; | |
6495 | ||
b9b0c831 NK |
6496 | mutex_lock(&graph_lock); |
6497 | ||
649b988b SRV |
6498 | fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash, |
6499 | lockdep_is_held(&graph_lock)); | |
b9b0c831 | 6500 | fgd->type = GRAPH_FILTER_NOTRACE; |
29ad23b0 NK |
6501 | fgd->seq_ops = &ftrace_graph_seq_ops; |
6502 | ||
b9b0c831 NK |
6503 | ret = __ftrace_graph_open(inode, file, fgd); |
6504 | if (ret < 0) | |
6505 | kfree(fgd); | |
6506 | ||
6507 | mutex_unlock(&graph_lock); | |
6508 | return ret; | |
29ad23b0 NK |
6509 | } |
6510 | ||
87827111 LZ |
6511 | static int |
6512 | ftrace_graph_release(struct inode *inode, struct file *file) | |
6513 | { | |
b9b0c831 | 6514 | struct ftrace_graph_data *fgd; |
e704eff3 SRV |
6515 | struct ftrace_hash *old_hash, *new_hash; |
6516 | struct trace_parser *parser; | |
6517 | int ret = 0; | |
b9b0c831 | 6518 | |
faf982a6 NK |
6519 | if (file->f_mode & FMODE_READ) { |
6520 | struct seq_file *m = file->private_data; | |
6521 | ||
b9b0c831 | 6522 | fgd = m->private; |
87827111 | 6523 | seq_release(inode, file); |
faf982a6 | 6524 | } else { |
b9b0c831 | 6525 | fgd = file->private_data; |
faf982a6 NK |
6526 | } |
6527 | ||
e704eff3 SRV |
6528 | |
6529 | if (file->f_mode & FMODE_WRITE) { | |
6530 | ||
6531 | parser = &fgd->parser; | |
6532 | ||
6533 | if (trace_parser_loaded((parser))) { | |
e704eff3 SRV |
6534 | ret = ftrace_graph_set_hash(fgd->new_hash, |
6535 | parser->buffer); | |
6536 | } | |
6537 | ||
6538 | trace_parser_put(parser); | |
6539 | ||
6540 | new_hash = __ftrace_hash_move(fgd->new_hash); | |
6541 | if (!new_hash) { | |
6542 | ret = -ENOMEM; | |
6543 | goto out; | |
6544 | } | |
6545 | ||
6546 | mutex_lock(&graph_lock); | |
6547 | ||
6548 | if (fgd->type == GRAPH_FILTER_FUNCTION) { | |
6549 | old_hash = rcu_dereference_protected(ftrace_graph_hash, | |
6550 | lockdep_is_held(&graph_lock)); | |
6551 | rcu_assign_pointer(ftrace_graph_hash, new_hash); | |
6552 | } else { | |
6553 | old_hash = rcu_dereference_protected(ftrace_graph_notrace_hash, | |
6554 | lockdep_is_held(&graph_lock)); | |
6555 | rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash); | |
6556 | } | |
6557 | ||
6558 | mutex_unlock(&graph_lock); | |
6559 | ||
54a16ff6 SRV |
6560 | /* |
6561 | * We need to do a hard force of sched synchronization. | |
6562 | * This is because we use preempt_disable() to do RCU, but | |
6563 | * the function tracers can be called where RCU is not watching | |
6564 | * (like before user_exit()). We can not rely on the RCU | |
6565 | * infrastructure to do the synchronization, thus we must do it | |
6566 | * ourselves. | |
6567 | */ | |
68e83498 NSJ |
6568 | if (old_hash != EMPTY_HASH) |
6569 | synchronize_rcu_tasks_rude(); | |
e704eff3 SRV |
6570 | |
6571 | free_ftrace_hash(old_hash); | |
6572 | } | |
6573 | ||
6574 | out: | |
f9797c2f | 6575 | free_ftrace_hash(fgd->new_hash); |
b9b0c831 NK |
6576 | kfree(fgd); |
6577 | ||
e704eff3 | 6578 | return ret; |
87827111 LZ |
6579 | } |
6580 | ||
ea4e2bc4 | 6581 | static int |
b9b0c831 | 6582 | ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer) |
ea4e2bc4 | 6583 | { |
3ba00929 | 6584 | struct ftrace_glob func_g; |
ea4e2bc4 SR |
6585 | struct dyn_ftrace *rec; |
6586 | struct ftrace_page *pg; | |
b9b0c831 | 6587 | struct ftrace_func_entry *entry; |
c7c6b1fe | 6588 | int fail = 1; |
3ba00929 | 6589 | int not; |
ea4e2bc4 | 6590 | |
f9349a8f | 6591 | /* decode regex */ |
3ba00929 DS |
6592 | func_g.type = filter_parse_regex(buffer, strlen(buffer), |
6593 | &func_g.search, ¬); | |
f9349a8f | 6594 | |
3ba00929 | 6595 | func_g.len = strlen(func_g.search); |
f9349a8f | 6596 | |
52baf119 | 6597 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
6598 | |
6599 | if (unlikely(ftrace_disabled)) { | |
6600 | mutex_unlock(&ftrace_lock); | |
6601 | return -ENODEV; | |
6602 | } | |
6603 | ||
265c831c SR |
6604 | do_for_each_ftrace_rec(pg, rec) { |
6605 | ||
546fece4 SRRH |
6606 | if (rec->flags & FTRACE_FL_DISABLED) |
6607 | continue; | |
6608 | ||
0b507e1e | 6609 | if (ftrace_match_record(rec, &func_g, NULL, 0)) { |
b9b0c831 | 6610 | entry = ftrace_lookup_ip(hash, rec->ip); |
c7c6b1fe LZ |
6611 | |
6612 | if (!not) { | |
6613 | fail = 0; | |
b9b0c831 NK |
6614 | |
6615 | if (entry) | |
6616 | continue; | |
6617 | if (add_hash_entry(hash, rec->ip) < 0) | |
6618 | goto out; | |
c7c6b1fe | 6619 | } else { |
b9b0c831 NK |
6620 | if (entry) { |
6621 | free_hash_entry(hash, entry); | |
c7c6b1fe LZ |
6622 | fail = 0; |
6623 | } | |
6624 | } | |
ea4e2bc4 | 6625 | } |
265c831c | 6626 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 6627 | out: |
52baf119 | 6628 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 6629 | |
c7c6b1fe LZ |
6630 | if (fail) |
6631 | return -EINVAL; | |
6632 | ||
c7c6b1fe | 6633 | return 0; |
ea4e2bc4 SR |
6634 | } |
6635 | ||
6636 | static ssize_t | |
6637 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
6638 | size_t cnt, loff_t *ppos) | |
6639 | { | |
6a10108b | 6640 | ssize_t read, ret = 0; |
faf982a6 | 6641 | struct ftrace_graph_data *fgd = file->private_data; |
e704eff3 | 6642 | struct trace_parser *parser; |
ea4e2bc4 | 6643 | |
c7c6b1fe | 6644 | if (!cnt) |
ea4e2bc4 SR |
6645 | return 0; |
6646 | ||
ae98d27a SRV |
6647 | /* Read mode uses seq functions */ |
6648 | if (file->f_mode & FMODE_READ) { | |
6649 | struct seq_file *m = file->private_data; | |
6650 | fgd = m->private; | |
6651 | } | |
6652 | ||
e704eff3 | 6653 | parser = &fgd->parser; |
ea4e2bc4 | 6654 | |
e704eff3 | 6655 | read = trace_get_user(parser, ubuf, cnt, ppos); |
689fd8b6 | 6656 | |
e704eff3 SRV |
6657 | if (read >= 0 && trace_parser_loaded(parser) && |
6658 | !trace_parser_cont(parser)) { | |
6a10108b | 6659 | |
b9b0c831 | 6660 | ret = ftrace_graph_set_hash(fgd->new_hash, |
e704eff3 SRV |
6661 | parser->buffer); |
6662 | trace_parser_clear(parser); | |
ea4e2bc4 | 6663 | } |
ea4e2bc4 | 6664 | |
6a10108b NK |
6665 | if (!ret) |
6666 | ret = read; | |
1eb90f13 | 6667 | |
ea4e2bc4 SR |
6668 | return ret; |
6669 | } | |
6670 | ||
6671 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
6672 | .open = ftrace_graph_open, |
6673 | .read = seq_read, | |
6674 | .write = ftrace_graph_write, | |
098c879e | 6675 | .llseek = tracing_lseek, |
87827111 | 6676 | .release = ftrace_graph_release, |
ea4e2bc4 | 6677 | }; |
29ad23b0 NK |
6678 | |
6679 | static const struct file_operations ftrace_graph_notrace_fops = { | |
6680 | .open = ftrace_graph_notrace_open, | |
6681 | .read = seq_read, | |
6682 | .write = ftrace_graph_write, | |
098c879e | 6683 | .llseek = tracing_lseek, |
29ad23b0 NK |
6684 | .release = ftrace_graph_release, |
6685 | }; | |
ea4e2bc4 SR |
6686 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
6687 | ||
591dffda SRRH |
6688 | void ftrace_create_filter_files(struct ftrace_ops *ops, |
6689 | struct dentry *parent) | |
6690 | { | |
6691 | ||
21ccc9cd | 6692 | trace_create_file("set_ftrace_filter", TRACE_MODE_WRITE, parent, |
591dffda SRRH |
6693 | ops, &ftrace_filter_fops); |
6694 | ||
21ccc9cd | 6695 | trace_create_file("set_ftrace_notrace", TRACE_MODE_WRITE, parent, |
591dffda SRRH |
6696 | ops, &ftrace_notrace_fops); |
6697 | } | |
6698 | ||
6699 | /* | |
6700 | * The name "destroy_filter_files" is really a misnomer. Although | |
9efb85c5 | 6701 | * in the future, it may actually delete the files, but this is |
591dffda SRRH |
6702 | * really intended to make sure the ops passed in are disabled |
6703 | * and that when this function returns, the caller is free to | |
6704 | * free the ops. | |
6705 | * | |
6706 | * The "destroy" name is only to match the "create" name that this | |
6707 | * should be paired with. | |
6708 | */ | |
6709 | void ftrace_destroy_filter_files(struct ftrace_ops *ops) | |
6710 | { | |
6711 | mutex_lock(&ftrace_lock); | |
6712 | if (ops->flags & FTRACE_OPS_FL_ENABLED) | |
6713 | ftrace_shutdown(ops, 0); | |
6714 | ops->flags |= FTRACE_OPS_FL_DELETED; | |
2840f84f | 6715 | ftrace_free_filter(ops); |
591dffda SRRH |
6716 | mutex_unlock(&ftrace_lock); |
6717 | } | |
6718 | ||
8434dc93 | 6719 | static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer) |
5072c59f | 6720 | { |
5072c59f | 6721 | |
21ccc9cd | 6722 | trace_create_file("available_filter_functions", TRACE_MODE_READ, |
5452af66 | 6723 | d_tracer, NULL, &ftrace_avail_fops); |
5072c59f | 6724 | |
21ccc9cd | 6725 | trace_create_file("enabled_functions", TRACE_MODE_READ, |
647bcd03 SR |
6726 | d_tracer, NULL, &ftrace_enabled_fops); |
6727 | ||
591dffda | 6728 | ftrace_create_filter_files(&global_ops, d_tracer); |
ad90c0e3 | 6729 | |
ea4e2bc4 | 6730 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
21ccc9cd | 6731 | trace_create_file("set_graph_function", TRACE_MODE_WRITE, d_tracer, |
ea4e2bc4 SR |
6732 | NULL, |
6733 | &ftrace_graph_fops); | |
21ccc9cd | 6734 | trace_create_file("set_graph_notrace", TRACE_MODE_WRITE, d_tracer, |
29ad23b0 NK |
6735 | NULL, |
6736 | &ftrace_graph_notrace_fops); | |
ea4e2bc4 SR |
6737 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
6738 | ||
5072c59f SR |
6739 | return 0; |
6740 | } | |
6741 | ||
9fd49328 | 6742 | static int ftrace_cmp_ips(const void *a, const void *b) |
68950619 | 6743 | { |
9fd49328 SR |
6744 | const unsigned long *ipa = a; |
6745 | const unsigned long *ipb = b; | |
68950619 | 6746 | |
9fd49328 SR |
6747 | if (*ipa > *ipb) |
6748 | return 1; | |
6749 | if (*ipa < *ipb) | |
6750 | return -1; | |
6751 | return 0; | |
6752 | } | |
6753 | ||
8147dc78 SRV |
6754 | #ifdef CONFIG_FTRACE_SORT_STARTUP_TEST |
6755 | static void test_is_sorted(unsigned long *start, unsigned long count) | |
6756 | { | |
6757 | int i; | |
6758 | ||
6759 | for (i = 1; i < count; i++) { | |
6760 | if (WARN(start[i - 1] > start[i], | |
6761 | "[%d] %pS at %lx is not sorted with %pS at %lx\n", i, | |
6762 | (void *)start[i - 1], start[i - 1], | |
6763 | (void *)start[i], start[i])) | |
6764 | break; | |
6765 | } | |
6766 | if (i == count) | |
6767 | pr_info("ftrace section at %px sorted properly\n", start); | |
6768 | } | |
6769 | #else | |
6770 | static void test_is_sorted(unsigned long *start, unsigned long count) | |
6771 | { | |
6772 | } | |
6773 | #endif | |
6774 | ||
5cb084bb | 6775 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 6776 | unsigned long *start, |
68bf21aa SR |
6777 | unsigned long *end) |
6778 | { | |
706c81f8 | 6779 | struct ftrace_page *start_pg; |
a7900875 | 6780 | struct ftrace_page *pg; |
706c81f8 | 6781 | struct dyn_ftrace *rec; |
a7900875 | 6782 | unsigned long count; |
68bf21aa SR |
6783 | unsigned long *p; |
6784 | unsigned long addr; | |
4376cac6 | 6785 | unsigned long flags = 0; /* Shut up gcc */ |
a7900875 SR |
6786 | int ret = -ENOMEM; |
6787 | ||
6788 | count = end - start; | |
6789 | ||
6790 | if (!count) | |
6791 | return 0; | |
6792 | ||
72b3942a YL |
6793 | /* |
6794 | * Sorting mcount in vmlinux at build time depend on | |
6b9b6413 | 6795 | * CONFIG_BUILDTIME_MCOUNT_SORT, while mcount loc in |
72b3942a YL |
6796 | * modules can not be sorted at build time. |
6797 | */ | |
6b9b6413 | 6798 | if (!IS_ENABLED(CONFIG_BUILDTIME_MCOUNT_SORT) || mod) { |
72b3942a YL |
6799 | sort(start, count, sizeof(*start), |
6800 | ftrace_cmp_ips, NULL); | |
8147dc78 SRV |
6801 | } else { |
6802 | test_is_sorted(start, count); | |
72b3942a | 6803 | } |
9fd49328 | 6804 | |
706c81f8 SR |
6805 | start_pg = ftrace_allocate_pages(count); |
6806 | if (!start_pg) | |
a7900875 | 6807 | return -ENOMEM; |
68bf21aa | 6808 | |
e6ea44e9 | 6809 | mutex_lock(&ftrace_lock); |
a7900875 | 6810 | |
32082309 SR |
6811 | /* |
6812 | * Core and each module needs their own pages, as | |
6813 | * modules will free them when they are removed. | |
6814 | * Force a new page to be allocated for modules. | |
6815 | */ | |
a7900875 SR |
6816 | if (!mod) { |
6817 | WARN_ON(ftrace_pages || ftrace_pages_start); | |
6818 | /* First initialization */ | |
706c81f8 | 6819 | ftrace_pages = ftrace_pages_start = start_pg; |
a7900875 | 6820 | } else { |
32082309 | 6821 | if (!ftrace_pages) |
a7900875 | 6822 | goto out; |
32082309 | 6823 | |
a7900875 SR |
6824 | if (WARN_ON(ftrace_pages->next)) { |
6825 | /* Hmm, we have free pages? */ | |
6826 | while (ftrace_pages->next) | |
6827 | ftrace_pages = ftrace_pages->next; | |
32082309 | 6828 | } |
a7900875 | 6829 | |
706c81f8 | 6830 | ftrace_pages->next = start_pg; |
32082309 SR |
6831 | } |
6832 | ||
68bf21aa | 6833 | p = start; |
706c81f8 | 6834 | pg = start_pg; |
68bf21aa | 6835 | while (p < end) { |
db42523b | 6836 | unsigned long end_offset; |
68bf21aa | 6837 | addr = ftrace_call_adjust(*p++); |
20e5227e SR |
6838 | /* |
6839 | * Some architecture linkers will pad between | |
6840 | * the different mcount_loc sections of different | |
6841 | * object files to satisfy alignments. | |
6842 | * Skip any NULL pointers. | |
6843 | */ | |
6844 | if (!addr) | |
6845 | continue; | |
706c81f8 | 6846 | |
db42523b LT |
6847 | end_offset = (pg->index+1) * sizeof(pg->records[0]); |
6848 | if (end_offset > PAGE_SIZE << pg->order) { | |
706c81f8 SR |
6849 | /* We should have allocated enough */ |
6850 | if (WARN_ON(!pg->next)) | |
6851 | break; | |
6852 | pg = pg->next; | |
6853 | } | |
6854 | ||
6855 | rec = &pg->records[pg->index++]; | |
6856 | rec->ip = addr; | |
68bf21aa SR |
6857 | } |
6858 | ||
706c81f8 SR |
6859 | /* We should have used all pages */ |
6860 | WARN_ON(pg->next); | |
6861 | ||
6862 | /* Assign the last page to ftrace_pages */ | |
6863 | ftrace_pages = pg; | |
6864 | ||
a4f18ed1 | 6865 | /* |
4376cac6 SR |
6866 | * We only need to disable interrupts on start up |
6867 | * because we are modifying code that an interrupt | |
6868 | * may execute, and the modification is not atomic. | |
6869 | * But for modules, nothing runs the code we modify | |
6870 | * until we are finished with it, and there's no | |
6871 | * reason to cause large interrupt latencies while we do it. | |
a4f18ed1 | 6872 | */ |
4376cac6 SR |
6873 | if (!mod) |
6874 | local_irq_save(flags); | |
1dc43cf0 | 6875 | ftrace_update_code(mod, start_pg); |
4376cac6 SR |
6876 | if (!mod) |
6877 | local_irq_restore(flags); | |
a7900875 SR |
6878 | ret = 0; |
6879 | out: | |
e6ea44e9 | 6880 | mutex_unlock(&ftrace_lock); |
68bf21aa | 6881 | |
a7900875 | 6882 | return ret; |
68bf21aa SR |
6883 | } |
6884 | ||
aba4b5c2 SRV |
6885 | struct ftrace_mod_func { |
6886 | struct list_head list; | |
6887 | char *name; | |
6888 | unsigned long ip; | |
6889 | unsigned int size; | |
6890 | }; | |
6891 | ||
6892 | struct ftrace_mod_map { | |
6aa69784 | 6893 | struct rcu_head rcu; |
aba4b5c2 SRV |
6894 | struct list_head list; |
6895 | struct module *mod; | |
6896 | unsigned long start_addr; | |
6897 | unsigned long end_addr; | |
6898 | struct list_head funcs; | |
6171a031 | 6899 | unsigned int num_funcs; |
aba4b5c2 SRV |
6900 | }; |
6901 | ||
fc0ea795 AH |
6902 | static int ftrace_get_trampoline_kallsym(unsigned int symnum, |
6903 | unsigned long *value, char *type, | |
6904 | char *name, char *module_name, | |
6905 | int *exported) | |
6906 | { | |
6907 | struct ftrace_ops *op; | |
6908 | ||
6909 | list_for_each_entry_rcu(op, &ftrace_ops_trampoline_list, list) { | |
6910 | if (!op->trampoline || symnum--) | |
6911 | continue; | |
6912 | *value = op->trampoline; | |
6913 | *type = 't'; | |
6914 | strlcpy(name, FTRACE_TRAMPOLINE_SYM, KSYM_NAME_LEN); | |
6915 | strlcpy(module_name, FTRACE_TRAMPOLINE_MOD, MODULE_NAME_LEN); | |
6916 | *exported = 0; | |
6917 | return 0; | |
6918 | } | |
6919 | ||
6920 | return -ERANGE; | |
6921 | } | |
6922 | ||
123d6455 WJ |
6923 | #if defined(CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS) || defined(CONFIG_MODULES) |
6924 | /* | |
6925 | * Check if the current ops references the given ip. | |
6926 | * | |
6927 | * If the ops traces all functions, then it was already accounted for. | |
6928 | * If the ops does not trace the current record function, skip it. | |
6929 | * If the ops ignores the function via notrace filter, skip it. | |
6930 | */ | |
6931 | static bool | |
6932 | ops_references_ip(struct ftrace_ops *ops, unsigned long ip) | |
6933 | { | |
6934 | /* If ops isn't enabled, ignore it */ | |
6935 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
6936 | return false; | |
6937 | ||
6938 | /* If ops traces all then it includes this function */ | |
6939 | if (ops_traces_mod(ops)) | |
6940 | return true; | |
6941 | ||
6942 | /* The function must be in the filter */ | |
6943 | if (!ftrace_hash_empty(ops->func_hash->filter_hash) && | |
6944 | !__ftrace_lookup_ip(ops->func_hash->filter_hash, ip)) | |
6945 | return false; | |
6946 | ||
6947 | /* If in notrace hash, we ignore it too */ | |
6948 | if (ftrace_lookup_ip(ops->func_hash->notrace_hash, ip)) | |
6949 | return false; | |
6950 | ||
6951 | return true; | |
6952 | } | |
6953 | #endif | |
6954 | ||
93eb677d | 6955 | #ifdef CONFIG_MODULES |
32082309 SR |
6956 | |
6957 | #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next) | |
6958 | ||
6aa69784 SRV |
6959 | static LIST_HEAD(ftrace_mod_maps); |
6960 | ||
b7ffffbb SRRH |
6961 | static int referenced_filters(struct dyn_ftrace *rec) |
6962 | { | |
6963 | struct ftrace_ops *ops; | |
6964 | int cnt = 0; | |
6965 | ||
6966 | for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) { | |
123d6455 | 6967 | if (ops_references_ip(ops, rec->ip)) { |
c5f51572 CZ |
6968 | if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_DIRECT)) |
6969 | continue; | |
6970 | if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_IPMODIFY)) | |
6971 | continue; | |
8a224ffb CZ |
6972 | cnt++; |
6973 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) | |
6974 | rec->flags |= FTRACE_FL_REGS; | |
c5f51572 CZ |
6975 | if (cnt == 1 && ops->trampoline) |
6976 | rec->flags |= FTRACE_FL_TRAMP; | |
6977 | else | |
6978 | rec->flags &= ~FTRACE_FL_TRAMP; | |
8a224ffb | 6979 | } |
b7ffffbb SRRH |
6980 | } |
6981 | ||
6982 | return cnt; | |
6983 | } | |
6984 | ||
2a5bfe47 SRV |
6985 | static void |
6986 | clear_mod_from_hash(struct ftrace_page *pg, struct ftrace_hash *hash) | |
6987 | { | |
6988 | struct ftrace_func_entry *entry; | |
6989 | struct dyn_ftrace *rec; | |
6990 | int i; | |
6991 | ||
6992 | if (ftrace_hash_empty(hash)) | |
6993 | return; | |
6994 | ||
6995 | for (i = 0; i < pg->index; i++) { | |
6996 | rec = &pg->records[i]; | |
6997 | entry = __ftrace_lookup_ip(hash, rec->ip); | |
6998 | /* | |
6999 | * Do not allow this rec to match again. | |
7000 | * Yeah, it may waste some memory, but will be removed | |
7001 | * if/when the hash is modified again. | |
7002 | */ | |
7003 | if (entry) | |
7004 | entry->ip = 0; | |
7005 | } | |
7006 | } | |
7007 | ||
f2cc020d | 7008 | /* Clear any records from hashes */ |
2a5bfe47 SRV |
7009 | static void clear_mod_from_hashes(struct ftrace_page *pg) |
7010 | { | |
7011 | struct trace_array *tr; | |
7012 | ||
7013 | mutex_lock(&trace_types_lock); | |
7014 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
7015 | if (!tr->ops || !tr->ops->func_hash) | |
7016 | continue; | |
7017 | mutex_lock(&tr->ops->func_hash->regex_lock); | |
7018 | clear_mod_from_hash(pg, tr->ops->func_hash->filter_hash); | |
7019 | clear_mod_from_hash(pg, tr->ops->func_hash->notrace_hash); | |
7020 | mutex_unlock(&tr->ops->func_hash->regex_lock); | |
7021 | } | |
7022 | mutex_unlock(&trace_types_lock); | |
7023 | } | |
7024 | ||
6aa69784 SRV |
7025 | static void ftrace_free_mod_map(struct rcu_head *rcu) |
7026 | { | |
7027 | struct ftrace_mod_map *mod_map = container_of(rcu, struct ftrace_mod_map, rcu); | |
7028 | struct ftrace_mod_func *mod_func; | |
7029 | struct ftrace_mod_func *n; | |
7030 | ||
7031 | /* All the contents of mod_map are now not visible to readers */ | |
7032 | list_for_each_entry_safe(mod_func, n, &mod_map->funcs, list) { | |
7033 | kfree(mod_func->name); | |
7034 | list_del(&mod_func->list); | |
7035 | kfree(mod_func); | |
7036 | } | |
7037 | ||
7038 | kfree(mod_map); | |
7039 | } | |
7040 | ||
e7247a15 | 7041 | void ftrace_release_mod(struct module *mod) |
93eb677d | 7042 | { |
6aa69784 SRV |
7043 | struct ftrace_mod_map *mod_map; |
7044 | struct ftrace_mod_map *n; | |
93eb677d | 7045 | struct dyn_ftrace *rec; |
32082309 | 7046 | struct ftrace_page **last_pg; |
2a5bfe47 | 7047 | struct ftrace_page *tmp_page = NULL; |
93eb677d | 7048 | struct ftrace_page *pg; |
93eb677d | 7049 | |
45a4a237 SR |
7050 | mutex_lock(&ftrace_lock); |
7051 | ||
e7247a15 | 7052 | if (ftrace_disabled) |
45a4a237 | 7053 | goto out_unlock; |
93eb677d | 7054 | |
6aa69784 SRV |
7055 | list_for_each_entry_safe(mod_map, n, &ftrace_mod_maps, list) { |
7056 | if (mod_map->mod == mod) { | |
7057 | list_del_rcu(&mod_map->list); | |
74401729 | 7058 | call_rcu(&mod_map->rcu, ftrace_free_mod_map); |
6aa69784 SRV |
7059 | break; |
7060 | } | |
7061 | } | |
7062 | ||
32082309 SR |
7063 | /* |
7064 | * Each module has its own ftrace_pages, remove | |
7065 | * them from the list. | |
7066 | */ | |
7067 | last_pg = &ftrace_pages_start; | |
7068 | for (pg = ftrace_pages_start; pg; pg = *last_pg) { | |
7069 | rec = &pg->records[0]; | |
3e234289 SRV |
7070 | if (within_module_core(rec->ip, mod) || |
7071 | within_module_init(rec->ip, mod)) { | |
93eb677d | 7072 | /* |
32082309 SR |
7073 | * As core pages are first, the first |
7074 | * page should never be a module page. | |
93eb677d | 7075 | */ |
32082309 SR |
7076 | if (WARN_ON(pg == ftrace_pages_start)) |
7077 | goto out_unlock; | |
7078 | ||
7079 | /* Check if we are deleting the last page */ | |
7080 | if (pg == ftrace_pages) | |
7081 | ftrace_pages = next_to_ftrace_page(last_pg); | |
7082 | ||
83dd1493 | 7083 | ftrace_update_tot_cnt -= pg->index; |
32082309 | 7084 | *last_pg = pg->next; |
2a5bfe47 SRV |
7085 | |
7086 | pg->next = tmp_page; | |
7087 | tmp_page = pg; | |
32082309 SR |
7088 | } else |
7089 | last_pg = &pg->next; | |
7090 | } | |
45a4a237 | 7091 | out_unlock: |
93eb677d | 7092 | mutex_unlock(&ftrace_lock); |
2a5bfe47 SRV |
7093 | |
7094 | for (pg = tmp_page; pg; pg = tmp_page) { | |
7095 | ||
7096 | /* Needs to be called outside of ftrace_lock */ | |
7097 | clear_mod_from_hashes(pg); | |
7098 | ||
db42523b LT |
7099 | if (pg->records) { |
7100 | free_pages((unsigned long)pg->records, pg->order); | |
7101 | ftrace_number_of_pages -= 1 << pg->order; | |
7102 | } | |
2a5bfe47 SRV |
7103 | tmp_page = pg->next; |
7104 | kfree(pg); | |
da537f0a | 7105 | ftrace_number_of_groups--; |
2a5bfe47 | 7106 | } |
93eb677d SR |
7107 | } |
7108 | ||
7dcd182b | 7109 | void ftrace_module_enable(struct module *mod) |
b7ffffbb SRRH |
7110 | { |
7111 | struct dyn_ftrace *rec; | |
7112 | struct ftrace_page *pg; | |
7113 | ||
7114 | mutex_lock(&ftrace_lock); | |
7115 | ||
7116 | if (ftrace_disabled) | |
7117 | goto out_unlock; | |
7118 | ||
7119 | /* | |
7120 | * If the tracing is enabled, go ahead and enable the record. | |
7121 | * | |
9efb85c5 | 7122 | * The reason not to enable the record immediately is the |
b7ffffbb SRRH |
7123 | * inherent check of ftrace_make_nop/ftrace_make_call for |
7124 | * correct previous instructions. Making first the NOP | |
7125 | * conversion puts the module to the correct state, thus | |
7126 | * passing the ftrace_make_call check. | |
7127 | * | |
7128 | * We also delay this to after the module code already set the | |
7129 | * text to read-only, as we now need to set it back to read-write | |
7130 | * so that we can modify the text. | |
7131 | */ | |
7132 | if (ftrace_start_up) | |
7133 | ftrace_arch_code_modify_prepare(); | |
7134 | ||
7135 | do_for_each_ftrace_rec(pg, rec) { | |
7136 | int cnt; | |
7137 | /* | |
7138 | * do_for_each_ftrace_rec() is a double loop. | |
7139 | * module text shares the pg. If a record is | |
7140 | * not part of this module, then skip this pg, | |
7141 | * which the "break" will do. | |
7142 | */ | |
3e234289 SRV |
7143 | if (!within_module_core(rec->ip, mod) && |
7144 | !within_module_init(rec->ip, mod)) | |
b7ffffbb SRRH |
7145 | break; |
7146 | ||
b39181f7 SRG |
7147 | /* Weak functions should still be ignored */ |
7148 | if (!test_for_valid_rec(rec)) { | |
7149 | /* Clear all other flags. Should not be enabled anyway */ | |
7150 | rec->flags = FTRACE_FL_DISABLED; | |
7151 | continue; | |
7152 | } | |
7153 | ||
b7ffffbb SRRH |
7154 | cnt = 0; |
7155 | ||
7156 | /* | |
7157 | * When adding a module, we need to check if tracers are | |
7158 | * currently enabled and if they are, and can trace this record, | |
7159 | * we need to enable the module functions as well as update the | |
7160 | * reference counts for those function records. | |
7161 | */ | |
7162 | if (ftrace_start_up) | |
7163 | cnt += referenced_filters(rec); | |
7164 | ||
8a224ffb CZ |
7165 | rec->flags &= ~FTRACE_FL_DISABLED; |
7166 | rec->flags += cnt; | |
b7ffffbb SRRH |
7167 | |
7168 | if (ftrace_start_up && cnt) { | |
7169 | int failed = __ftrace_replace_code(rec, 1); | |
7170 | if (failed) { | |
7171 | ftrace_bug(failed, rec); | |
7172 | goto out_loop; | |
7173 | } | |
7174 | } | |
7175 | ||
7176 | } while_for_each_ftrace_rec(); | |
7177 | ||
7178 | out_loop: | |
7179 | if (ftrace_start_up) | |
7180 | ftrace_arch_code_modify_post_process(); | |
7181 | ||
7182 | out_unlock: | |
7183 | mutex_unlock(&ftrace_lock); | |
d7fbf8df SRV |
7184 | |
7185 | process_cached_mods(mod->name); | |
b7ffffbb SRRH |
7186 | } |
7187 | ||
b6b71f66 | 7188 | void ftrace_module_init(struct module *mod) |
90d595fe | 7189 | { |
2889c658 YW |
7190 | int ret; |
7191 | ||
97e9b4fc | 7192 | if (ftrace_disabled || !mod->num_ftrace_callsites) |
fed1939c | 7193 | return; |
90d595fe | 7194 | |
2889c658 YW |
7195 | ret = ftrace_process_locs(mod, mod->ftrace_callsites, |
7196 | mod->ftrace_callsites + mod->num_ftrace_callsites); | |
7197 | if (ret) | |
7198 | pr_warn("ftrace: failed to allocate entries for module '%s' functions\n", | |
7199 | mod->name); | |
8c189ea6 | 7200 | } |
aba4b5c2 SRV |
7201 | |
7202 | static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map, | |
7203 | struct dyn_ftrace *rec) | |
7204 | { | |
7205 | struct ftrace_mod_func *mod_func; | |
7206 | unsigned long symsize; | |
7207 | unsigned long offset; | |
7208 | char str[KSYM_SYMBOL_LEN]; | |
7209 | char *modname; | |
7210 | const char *ret; | |
7211 | ||
7212 | ret = kallsyms_lookup(rec->ip, &symsize, &offset, &modname, str); | |
7213 | if (!ret) | |
7214 | return; | |
7215 | ||
7216 | mod_func = kmalloc(sizeof(*mod_func), GFP_KERNEL); | |
7217 | if (!mod_func) | |
7218 | return; | |
7219 | ||
7220 | mod_func->name = kstrdup(str, GFP_KERNEL); | |
7221 | if (!mod_func->name) { | |
7222 | kfree(mod_func); | |
7223 | return; | |
7224 | } | |
7225 | ||
7226 | mod_func->ip = rec->ip - offset; | |
7227 | mod_func->size = symsize; | |
7228 | ||
6171a031 SRV |
7229 | mod_map->num_funcs++; |
7230 | ||
aba4b5c2 SRV |
7231 | list_add_rcu(&mod_func->list, &mod_map->funcs); |
7232 | } | |
7233 | ||
aba4b5c2 SRV |
7234 | static struct ftrace_mod_map * |
7235 | allocate_ftrace_mod_map(struct module *mod, | |
7236 | unsigned long start, unsigned long end) | |
7237 | { | |
7238 | struct ftrace_mod_map *mod_map; | |
7239 | ||
7240 | mod_map = kmalloc(sizeof(*mod_map), GFP_KERNEL); | |
7241 | if (!mod_map) | |
7242 | return NULL; | |
7243 | ||
7244 | mod_map->mod = mod; | |
7245 | mod_map->start_addr = start; | |
7246 | mod_map->end_addr = end; | |
6171a031 | 7247 | mod_map->num_funcs = 0; |
aba4b5c2 SRV |
7248 | |
7249 | INIT_LIST_HEAD_RCU(&mod_map->funcs); | |
7250 | ||
7251 | list_add_rcu(&mod_map->list, &ftrace_mod_maps); | |
7252 | ||
7253 | return mod_map; | |
7254 | } | |
7255 | ||
7256 | static const char * | |
7257 | ftrace_func_address_lookup(struct ftrace_mod_map *mod_map, | |
7258 | unsigned long addr, unsigned long *size, | |
7259 | unsigned long *off, char *sym) | |
7260 | { | |
7261 | struct ftrace_mod_func *found_func = NULL; | |
7262 | struct ftrace_mod_func *mod_func; | |
7263 | ||
7264 | list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) { | |
7265 | if (addr >= mod_func->ip && | |
7266 | addr < mod_func->ip + mod_func->size) { | |
7267 | found_func = mod_func; | |
7268 | break; | |
7269 | } | |
7270 | } | |
7271 | ||
7272 | if (found_func) { | |
7273 | if (size) | |
7274 | *size = found_func->size; | |
7275 | if (off) | |
7276 | *off = addr - found_func->ip; | |
7277 | if (sym) | |
7278 | strlcpy(sym, found_func->name, KSYM_NAME_LEN); | |
7279 | ||
7280 | return found_func->name; | |
7281 | } | |
7282 | ||
7283 | return NULL; | |
7284 | } | |
7285 | ||
7286 | const char * | |
7287 | ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, | |
7288 | unsigned long *off, char **modname, char *sym) | |
7289 | { | |
7290 | struct ftrace_mod_map *mod_map; | |
7291 | const char *ret = NULL; | |
7292 | ||
74401729 | 7293 | /* mod_map is freed via call_rcu() */ |
aba4b5c2 SRV |
7294 | preempt_disable(); |
7295 | list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) { | |
7296 | ret = ftrace_func_address_lookup(mod_map, addr, size, off, sym); | |
7297 | if (ret) { | |
7298 | if (modname) | |
7299 | *modname = mod_map->mod->name; | |
7300 | break; | |
7301 | } | |
7302 | } | |
7303 | preempt_enable(); | |
7304 | ||
7305 | return ret; | |
7306 | } | |
7307 | ||
6171a031 SRV |
7308 | int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, |
7309 | char *type, char *name, | |
7310 | char *module_name, int *exported) | |
7311 | { | |
7312 | struct ftrace_mod_map *mod_map; | |
7313 | struct ftrace_mod_func *mod_func; | |
fc0ea795 | 7314 | int ret; |
6171a031 SRV |
7315 | |
7316 | preempt_disable(); | |
7317 | list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) { | |
7318 | ||
7319 | if (symnum >= mod_map->num_funcs) { | |
7320 | symnum -= mod_map->num_funcs; | |
7321 | continue; | |
7322 | } | |
7323 | ||
7324 | list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) { | |
7325 | if (symnum > 1) { | |
7326 | symnum--; | |
7327 | continue; | |
7328 | } | |
7329 | ||
7330 | *value = mod_func->ip; | |
7331 | *type = 'T'; | |
7332 | strlcpy(name, mod_func->name, KSYM_NAME_LEN); | |
7333 | strlcpy(module_name, mod_map->mod->name, MODULE_NAME_LEN); | |
7334 | *exported = 1; | |
7335 | preempt_enable(); | |
7336 | return 0; | |
7337 | } | |
7338 | WARN_ON(1); | |
7339 | break; | |
7340 | } | |
fc0ea795 AH |
7341 | ret = ftrace_get_trampoline_kallsym(symnum, value, type, name, |
7342 | module_name, exported); | |
6171a031 | 7343 | preempt_enable(); |
fc0ea795 | 7344 | return ret; |
6171a031 SRV |
7345 | } |
7346 | ||
aba4b5c2 SRV |
7347 | #else |
7348 | static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map, | |
7349 | struct dyn_ftrace *rec) { } | |
7350 | static inline struct ftrace_mod_map * | |
7351 | allocate_ftrace_mod_map(struct module *mod, | |
7352 | unsigned long start, unsigned long end) | |
7353 | { | |
7354 | return NULL; | |
7355 | } | |
fc0ea795 AH |
7356 | int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, |
7357 | char *type, char *name, char *module_name, | |
7358 | int *exported) | |
7359 | { | |
7360 | int ret; | |
7361 | ||
7362 | preempt_disable(); | |
7363 | ret = ftrace_get_trampoline_kallsym(symnum, value, type, name, | |
7364 | module_name, exported); | |
7365 | preempt_enable(); | |
7366 | return ret; | |
7367 | } | |
93eb677d SR |
7368 | #endif /* CONFIG_MODULES */ |
7369 | ||
8715b108 JF |
7370 | struct ftrace_init_func { |
7371 | struct list_head list; | |
7372 | unsigned long ip; | |
7373 | }; | |
7374 | ||
7375 | /* Clear any init ips from hashes */ | |
7376 | static void | |
7377 | clear_func_from_hash(struct ftrace_init_func *func, struct ftrace_hash *hash) | |
42c269c8 | 7378 | { |
8715b108 JF |
7379 | struct ftrace_func_entry *entry; |
7380 | ||
08468754 | 7381 | entry = ftrace_lookup_ip(hash, func->ip); |
8715b108 JF |
7382 | /* |
7383 | * Do not allow this rec to match again. | |
7384 | * Yeah, it may waste some memory, but will be removed | |
7385 | * if/when the hash is modified again. | |
7386 | */ | |
7387 | if (entry) | |
7388 | entry->ip = 0; | |
7389 | } | |
7390 | ||
7391 | static void | |
7392 | clear_func_from_hashes(struct ftrace_init_func *func) | |
7393 | { | |
7394 | struct trace_array *tr; | |
7395 | ||
7396 | mutex_lock(&trace_types_lock); | |
7397 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
7398 | if (!tr->ops || !tr->ops->func_hash) | |
7399 | continue; | |
7400 | mutex_lock(&tr->ops->func_hash->regex_lock); | |
7401 | clear_func_from_hash(func, tr->ops->func_hash->filter_hash); | |
7402 | clear_func_from_hash(func, tr->ops->func_hash->notrace_hash); | |
7403 | mutex_unlock(&tr->ops->func_hash->regex_lock); | |
7404 | } | |
7405 | mutex_unlock(&trace_types_lock); | |
7406 | } | |
7407 | ||
7408 | static void add_to_clear_hash_list(struct list_head *clear_list, | |
7409 | struct dyn_ftrace *rec) | |
7410 | { | |
7411 | struct ftrace_init_func *func; | |
7412 | ||
7413 | func = kmalloc(sizeof(*func), GFP_KERNEL); | |
7414 | if (!func) { | |
24589e3a | 7415 | MEM_FAIL(1, "alloc failure, ftrace filter could be stale\n"); |
8715b108 JF |
7416 | return; |
7417 | } | |
7418 | ||
7419 | func->ip = rec->ip; | |
7420 | list_add(&func->list, clear_list); | |
7421 | } | |
7422 | ||
aba4b5c2 | 7423 | void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr) |
42c269c8 | 7424 | { |
6cafbe15 SRV |
7425 | unsigned long start = (unsigned long)(start_ptr); |
7426 | unsigned long end = (unsigned long)(end_ptr); | |
42c269c8 SRV |
7427 | struct ftrace_page **last_pg = &ftrace_pages_start; |
7428 | struct ftrace_page *pg; | |
7429 | struct dyn_ftrace *rec; | |
7430 | struct dyn_ftrace key; | |
aba4b5c2 | 7431 | struct ftrace_mod_map *mod_map = NULL; |
8715b108 JF |
7432 | struct ftrace_init_func *func, *func_next; |
7433 | struct list_head clear_hash; | |
42c269c8 | 7434 | |
8715b108 JF |
7435 | INIT_LIST_HEAD(&clear_hash); |
7436 | ||
42c269c8 SRV |
7437 | key.ip = start; |
7438 | key.flags = end; /* overload flags, as it is unsigned long */ | |
7439 | ||
7440 | mutex_lock(&ftrace_lock); | |
7441 | ||
aba4b5c2 SRV |
7442 | /* |
7443 | * If we are freeing module init memory, then check if | |
7444 | * any tracer is active. If so, we need to save a mapping of | |
7445 | * the module functions being freed with the address. | |
7446 | */ | |
7447 | if (mod && ftrace_ops_list != &ftrace_list_end) | |
7448 | mod_map = allocate_ftrace_mod_map(mod, start, end); | |
7449 | ||
42c269c8 SRV |
7450 | for (pg = ftrace_pages_start; pg; last_pg = &pg->next, pg = *last_pg) { |
7451 | if (end < pg->records[0].ip || | |
7452 | start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) | |
7453 | continue; | |
7454 | again: | |
7455 | rec = bsearch(&key, pg->records, pg->index, | |
7456 | sizeof(struct dyn_ftrace), | |
7457 | ftrace_cmp_recs); | |
7458 | if (!rec) | |
7459 | continue; | |
aba4b5c2 | 7460 | |
8715b108 JF |
7461 | /* rec will be cleared from hashes after ftrace_lock unlock */ |
7462 | add_to_clear_hash_list(&clear_hash, rec); | |
7463 | ||
aba4b5c2 SRV |
7464 | if (mod_map) |
7465 | save_ftrace_mod_rec(mod_map, rec); | |
7466 | ||
42c269c8 | 7467 | pg->index--; |
4ec78467 | 7468 | ftrace_update_tot_cnt--; |
42c269c8 SRV |
7469 | if (!pg->index) { |
7470 | *last_pg = pg->next; | |
db42523b LT |
7471 | if (pg->records) { |
7472 | free_pages((unsigned long)pg->records, pg->order); | |
7473 | ftrace_number_of_pages -= 1 << pg->order; | |
7474 | } | |
da537f0a | 7475 | ftrace_number_of_groups--; |
42c269c8 SRV |
7476 | kfree(pg); |
7477 | pg = container_of(last_pg, struct ftrace_page, next); | |
7478 | if (!(*last_pg)) | |
7479 | ftrace_pages = pg; | |
7480 | continue; | |
7481 | } | |
7482 | memmove(rec, rec + 1, | |
7483 | (pg->index - (rec - pg->records)) * sizeof(*rec)); | |
7484 | /* More than one function may be in this block */ | |
7485 | goto again; | |
7486 | } | |
7487 | mutex_unlock(&ftrace_lock); | |
8715b108 JF |
7488 | |
7489 | list_for_each_entry_safe(func, func_next, &clear_hash, list) { | |
7490 | clear_func_from_hashes(func); | |
7491 | kfree(func); | |
7492 | } | |
42c269c8 SRV |
7493 | } |
7494 | ||
6cafbe15 SRV |
7495 | void __init ftrace_free_init_mem(void) |
7496 | { | |
7497 | void *start = (void *)(&__init_begin); | |
7498 | void *end = (void *)(&__init_end); | |
7499 | ||
380af29b SRG |
7500 | ftrace_boot_snapshot(); |
7501 | ||
aba4b5c2 | 7502 | ftrace_free_mem(NULL, start, end); |
42c269c8 SRV |
7503 | } |
7504 | ||
6644c654 WO |
7505 | int __init __weak ftrace_dyn_arch_init(void) |
7506 | { | |
7507 | return 0; | |
7508 | } | |
7509 | ||
68bf21aa SR |
7510 | void __init ftrace_init(void) |
7511 | { | |
1dc43cf0 JS |
7512 | extern unsigned long __start_mcount_loc[]; |
7513 | extern unsigned long __stop_mcount_loc[]; | |
3a36cb11 | 7514 | unsigned long count, flags; |
68bf21aa SR |
7515 | int ret; |
7516 | ||
68bf21aa | 7517 | local_irq_save(flags); |
3a36cb11 | 7518 | ret = ftrace_dyn_arch_init(); |
68bf21aa | 7519 | local_irq_restore(flags); |
af64a7cb | 7520 | if (ret) |
68bf21aa SR |
7521 | goto failed; |
7522 | ||
7523 | count = __stop_mcount_loc - __start_mcount_loc; | |
c867ccd8 JS |
7524 | if (!count) { |
7525 | pr_info("ftrace: No functions to be traced?\n"); | |
68bf21aa | 7526 | goto failed; |
c867ccd8 JS |
7527 | } |
7528 | ||
7529 | pr_info("ftrace: allocating %ld entries in %ld pages\n", | |
08948cae | 7530 | count, DIV_ROUND_UP(count, ENTRIES_PER_PAGE)); |
68bf21aa | 7531 | |
5cb084bb | 7532 | ret = ftrace_process_locs(NULL, |
31e88909 | 7533 | __start_mcount_loc, |
68bf21aa | 7534 | __stop_mcount_loc); |
2889c658 YW |
7535 | if (ret) { |
7536 | pr_warn("ftrace: failed to allocate entries for functions\n"); | |
7537 | goto failed; | |
7538 | } | |
68bf21aa | 7539 | |
da537f0a SRV |
7540 | pr_info("ftrace: allocated %ld pages with %ld groups\n", |
7541 | ftrace_number_of_pages, ftrace_number_of_groups); | |
7542 | ||
2889c658 YW |
7543 | last_ftrace_enabled = ftrace_enabled = 1; |
7544 | ||
2af15d6a SR |
7545 | set_ftrace_early_filters(); |
7546 | ||
68bf21aa SR |
7547 | return; |
7548 | failed: | |
7549 | ftrace_disabled = 1; | |
7550 | } | |
68bf21aa | 7551 | |
f3bea491 SRRH |
7552 | /* Do nothing if arch does not support this */ |
7553 | void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops) | |
7554 | { | |
7555 | } | |
7556 | ||
7557 | static void ftrace_update_trampoline(struct ftrace_ops *ops) | |
7558 | { | |
fc0ea795 AH |
7559 | unsigned long trampoline = ops->trampoline; |
7560 | ||
f3bea491 | 7561 | arch_ftrace_update_trampoline(ops); |
fc0ea795 | 7562 | if (ops->trampoline && ops->trampoline != trampoline && |
dd9ddf46 AH |
7563 | (ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP)) { |
7564 | /* Add to kallsyms before the perf events */ | |
fc0ea795 | 7565 | ftrace_add_trampoline_to_kallsyms(ops); |
dd9ddf46 AH |
7566 | perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL, |
7567 | ops->trampoline, ops->trampoline_size, false, | |
7568 | FTRACE_TRAMPOLINE_SYM); | |
548e1f6c AH |
7569 | /* |
7570 | * Record the perf text poke event after the ksymbol register | |
7571 | * event. | |
7572 | */ | |
7573 | perf_event_text_poke((void *)ops->trampoline, NULL, 0, | |
7574 | (void *)ops->trampoline, | |
7575 | ops->trampoline_size); | |
dd9ddf46 | 7576 | } |
f3bea491 SRRH |
7577 | } |
7578 | ||
04ec7bb6 SRV |
7579 | void ftrace_init_trace_array(struct trace_array *tr) |
7580 | { | |
7581 | INIT_LIST_HEAD(&tr->func_probes); | |
673feb9d SRV |
7582 | INIT_LIST_HEAD(&tr->mod_trace); |
7583 | INIT_LIST_HEAD(&tr->mod_notrace); | |
04ec7bb6 | 7584 | } |
3d083395 | 7585 | #else |
0b6e4d56 | 7586 | |
3306fc4a | 7587 | struct ftrace_ops global_ops = { |
bd69c30b | 7588 | .func = ftrace_stub, |
a25d036d | 7589 | .flags = FTRACE_OPS_FL_INITIALIZED | |
e3eea140 | 7590 | FTRACE_OPS_FL_PID, |
bd69c30b SR |
7591 | }; |
7592 | ||
0b6e4d56 FW |
7593 | static int __init ftrace_nodyn_init(void) |
7594 | { | |
7595 | ftrace_enabled = 1; | |
7596 | return 0; | |
7597 | } | |
6f415672 | 7598 | core_initcall(ftrace_nodyn_init); |
0b6e4d56 | 7599 | |
8434dc93 | 7600 | static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; } |
e1effa01 | 7601 | static inline void ftrace_startup_all(int command) { } |
8a56d776 | 7602 | |
f3bea491 SRRH |
7603 | static void ftrace_update_trampoline(struct ftrace_ops *ops) |
7604 | { | |
7605 | } | |
7606 | ||
3d083395 SR |
7607 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
7608 | ||
4104d326 SRRH |
7609 | __init void ftrace_init_global_array_ops(struct trace_array *tr) |
7610 | { | |
7611 | tr->ops = &global_ops; | |
7612 | tr->ops->private = tr; | |
04ec7bb6 | 7613 | ftrace_init_trace_array(tr); |
4104d326 SRRH |
7614 | } |
7615 | ||
7616 | void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func) | |
7617 | { | |
7618 | /* If we filter on pids, update to use the pid function */ | |
7619 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL) { | |
7620 | if (WARN_ON(tr->ops->func != ftrace_stub)) | |
7621 | printk("ftrace ops had %pS for function\n", | |
7622 | tr->ops->func); | |
4104d326 SRRH |
7623 | } |
7624 | tr->ops->func = func; | |
7625 | tr->ops->private = tr; | |
7626 | } | |
7627 | ||
7628 | void ftrace_reset_array_ops(struct trace_array *tr) | |
7629 | { | |
7630 | tr->ops->func = ftrace_stub; | |
7631 | } | |
7632 | ||
fabe38ab | 7633 | static nokprobe_inline void |
2f5f6ad9 | 7634 | __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, |
d19ad077 | 7635 | struct ftrace_ops *ignored, struct ftrace_regs *fregs) |
b848914c | 7636 | { |
d19ad077 | 7637 | struct pt_regs *regs = ftrace_get_regs(fregs); |
cdbe61bf | 7638 | struct ftrace_ops *op; |
edc15caf | 7639 | int bit; |
b848914c | 7640 | |
ce5e4803 | 7641 | /* |
7642 | * The ftrace_test_and_set_recursion() will disable preemption, | |
7643 | * which is required since some of the ops may be dynamically | |
7644 | * allocated, they must be freed after a synchronize_rcu(). | |
7645 | */ | |
ed65df63 | 7646 | bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START); |
edc15caf SR |
7647 | if (bit < 0) |
7648 | return; | |
b1cff0ad | 7649 | |
0a016409 | 7650 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
2fa717a0 SRV |
7651 | /* Stub functions don't need to be called nor tested */ |
7652 | if (op->flags & FTRACE_OPS_FL_STUB) | |
7653 | continue; | |
ba27f2bc SRRH |
7654 | /* |
7655 | * Check the following for each ops before calling their func: | |
7656 | * if RCU flag is set, then rcu_is_watching() must be true | |
ba27f2bc SRRH |
7657 | * Otherwise test if the ip matches the ops filter |
7658 | * | |
7659 | * If any of the above fails then the op->func() is not executed. | |
7660 | */ | |
7661 | if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) && | |
ba27f2bc | 7662 | ftrace_ops_test(op, ip, regs)) { |
1d48d596 SRRH |
7663 | if (FTRACE_WARN_ON(!op->func)) { |
7664 | pr_warn("op=%p %pS\n", op, op); | |
4104d326 SRRH |
7665 | goto out; |
7666 | } | |
d19ad077 | 7667 | op->func(ip, parent_ip, op, fregs); |
4104d326 | 7668 | } |
0a016409 | 7669 | } while_for_each_ftrace_op(op); |
4104d326 | 7670 | out: |
edc15caf | 7671 | trace_clear_recursion(bit); |
b848914c SR |
7672 | } |
7673 | ||
2f5f6ad9 SR |
7674 | /* |
7675 | * Some archs only support passing ip and parent_ip. Even though | |
7676 | * the list function ignores the op parameter, we do not want any | |
7677 | * C side effects, where a function is called without the caller | |
7678 | * sending a third parameter. | |
a1e2e31d SR |
7679 | * Archs are to support both the regs and ftrace_ops at the same time. |
7680 | * If they support ftrace_ops, it is assumed they support regs. | |
7681 | * If call backs want to use regs, they must either check for regs | |
06aeaaea MH |
7682 | * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS. |
7683 | * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved. | |
a1e2e31d | 7684 | * An architecture can pass partial regs with ftrace_ops and still |
b8ec330a | 7685 | * set the ARCH_SUPPORTS_FTRACE_OPS. |
34cdd18b SRV |
7686 | * |
7687 | * In vmlinux.lds.h, ftrace_ops_list_func() is defined to be | |
7688 | * arch_ftrace_ops_list_func. | |
2f5f6ad9 SR |
7689 | */ |
7690 | #if ARCH_SUPPORTS_FTRACE_OPS | |
34cdd18b SRV |
7691 | void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, |
7692 | struct ftrace_ops *op, struct ftrace_regs *fregs) | |
2f5f6ad9 | 7693 | { |
d19ad077 | 7694 | __ftrace_ops_list_func(ip, parent_ip, NULL, fregs); |
2f5f6ad9 SR |
7695 | } |
7696 | #else | |
34cdd18b | 7697 | void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip) |
2f5f6ad9 | 7698 | { |
a1e2e31d | 7699 | __ftrace_ops_list_func(ip, parent_ip, NULL, NULL); |
2f5f6ad9 SR |
7700 | } |
7701 | #endif | |
34cdd18b | 7702 | NOKPROBE_SYMBOL(arch_ftrace_ops_list_func); |
2f5f6ad9 | 7703 | |
f1ff6348 SRRH |
7704 | /* |
7705 | * If there's only one function registered but it does not support | |
78a01feb ZY |
7706 | * recursion, needs RCU protection, then this function will be called |
7707 | * by the mcount trampoline. | |
f1ff6348 | 7708 | */ |
c68c0fa2 | 7709 | static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip, |
d19ad077 | 7710 | struct ftrace_ops *op, struct ftrace_regs *fregs) |
f1ff6348 SRRH |
7711 | { |
7712 | int bit; | |
7713 | ||
ed65df63 | 7714 | bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START); |
f1ff6348 SRRH |
7715 | if (bit < 0) |
7716 | return; | |
7717 | ||
b40341fa | 7718 | if (!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) |
d19ad077 | 7719 | op->func(ip, parent_ip, op, fregs); |
c68c0fa2 | 7720 | |
f1ff6348 SRRH |
7721 | trace_clear_recursion(bit); |
7722 | } | |
fabe38ab | 7723 | NOKPROBE_SYMBOL(ftrace_ops_assist_func); |
f1ff6348 | 7724 | |
87354059 SRRH |
7725 | /** |
7726 | * ftrace_ops_get_func - get the function a trampoline should call | |
7727 | * @ops: the ops to get the function for | |
7728 | * | |
7729 | * Normally the mcount trampoline will call the ops->func, but there | |
7730 | * are times that it should not. For example, if the ops does not | |
7731 | * have its own recursion protection, then it should call the | |
3a150df9 | 7732 | * ftrace_ops_assist_func() instead. |
87354059 SRRH |
7733 | * |
7734 | * Returns the function that the trampoline should call for @ops. | |
7735 | */ | |
7736 | ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops) | |
7737 | { | |
87354059 | 7738 | /* |
a25d036d SRV |
7739 | * If the function does not handle recursion or needs to be RCU safe, |
7740 | * then we need to call the assist handler. | |
87354059 | 7741 | */ |
a25d036d SRV |
7742 | if (ops->flags & (FTRACE_OPS_FL_RECURSION | |
7743 | FTRACE_OPS_FL_RCU)) | |
c68c0fa2 | 7744 | return ftrace_ops_assist_func; |
87354059 SRRH |
7745 | |
7746 | return ops->func; | |
7747 | } | |
7748 | ||
345ddcc8 SRRH |
7749 | static void |
7750 | ftrace_filter_pid_sched_switch_probe(void *data, bool preempt, | |
fa2c3254 | 7751 | struct task_struct *prev, |
9c2136be DK |
7752 | struct task_struct *next, |
7753 | unsigned int prev_state) | |
978f3a45 | 7754 | { |
345ddcc8 SRRH |
7755 | struct trace_array *tr = data; |
7756 | struct trace_pid_list *pid_list; | |
b3b1e6ed | 7757 | struct trace_pid_list *no_pid_list; |
978f3a45 | 7758 | |
345ddcc8 | 7759 | pid_list = rcu_dereference_sched(tr->function_pids); |
b3b1e6ed | 7760 | no_pid_list = rcu_dereference_sched(tr->function_no_pids); |
e32d8956 | 7761 | |
b3b1e6ed | 7762 | if (trace_ignore_this_task(pid_list, no_pid_list, next)) |
717e3f5e SRV |
7763 | this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, |
7764 | FTRACE_PID_IGNORE); | |
7765 | else | |
7766 | this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, | |
7767 | next->pid); | |
978f3a45 SR |
7768 | } |
7769 | ||
1e10486f NK |
7770 | static void |
7771 | ftrace_pid_follow_sched_process_fork(void *data, | |
7772 | struct task_struct *self, | |
7773 | struct task_struct *task) | |
7774 | { | |
7775 | struct trace_pid_list *pid_list; | |
7776 | struct trace_array *tr = data; | |
7777 | ||
7778 | pid_list = rcu_dereference_sched(tr->function_pids); | |
7779 | trace_filter_add_remove_task(pid_list, self, task); | |
b3b1e6ed SRV |
7780 | |
7781 | pid_list = rcu_dereference_sched(tr->function_no_pids); | |
7782 | trace_filter_add_remove_task(pid_list, self, task); | |
1e10486f NK |
7783 | } |
7784 | ||
7785 | static void | |
7786 | ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task) | |
7787 | { | |
7788 | struct trace_pid_list *pid_list; | |
7789 | struct trace_array *tr = data; | |
7790 | ||
7791 | pid_list = rcu_dereference_sched(tr->function_pids); | |
7792 | trace_filter_add_remove_task(pid_list, NULL, task); | |
b3b1e6ed SRV |
7793 | |
7794 | pid_list = rcu_dereference_sched(tr->function_no_pids); | |
7795 | trace_filter_add_remove_task(pid_list, NULL, task); | |
1e10486f NK |
7796 | } |
7797 | ||
7798 | void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) | |
7799 | { | |
7800 | if (enable) { | |
7801 | register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, | |
7802 | tr); | |
afcab636 | 7803 | register_trace_sched_process_free(ftrace_pid_follow_sched_process_exit, |
1e10486f NK |
7804 | tr); |
7805 | } else { | |
7806 | unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, | |
7807 | tr); | |
afcab636 | 7808 | unregister_trace_sched_process_free(ftrace_pid_follow_sched_process_exit, |
1e10486f NK |
7809 | tr); |
7810 | } | |
7811 | } | |
7812 | ||
b3b1e6ed | 7813 | static void clear_ftrace_pids(struct trace_array *tr, int type) |
e32d8956 | 7814 | { |
345ddcc8 | 7815 | struct trace_pid_list *pid_list; |
b3b1e6ed | 7816 | struct trace_pid_list *no_pid_list; |
345ddcc8 | 7817 | int cpu; |
e32d8956 | 7818 | |
345ddcc8 SRRH |
7819 | pid_list = rcu_dereference_protected(tr->function_pids, |
7820 | lockdep_is_held(&ftrace_lock)); | |
b3b1e6ed SRV |
7821 | no_pid_list = rcu_dereference_protected(tr->function_no_pids, |
7822 | lockdep_is_held(&ftrace_lock)); | |
7823 | ||
7824 | /* Make sure there's something to do */ | |
27683626 | 7825 | if (!pid_type_enabled(type, pid_list, no_pid_list)) |
345ddcc8 | 7826 | return; |
229c4ef8 | 7827 | |
b3b1e6ed | 7828 | /* See if the pids still need to be checked after this */ |
27683626 | 7829 | if (!still_need_pid_events(type, pid_list, no_pid_list)) { |
b3b1e6ed SRV |
7830 | unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr); |
7831 | for_each_possible_cpu(cpu) | |
7832 | per_cpu_ptr(tr->array_buffer.data, cpu)->ftrace_ignore_pid = FTRACE_PID_TRACE; | |
7833 | } | |
e32d8956 | 7834 | |
b3b1e6ed SRV |
7835 | if (type & TRACE_PIDS) |
7836 | rcu_assign_pointer(tr->function_pids, NULL); | |
978f3a45 | 7837 | |
b3b1e6ed SRV |
7838 | if (type & TRACE_NO_PIDS) |
7839 | rcu_assign_pointer(tr->function_no_pids, NULL); | |
978f3a45 | 7840 | |
345ddcc8 | 7841 | /* Wait till all users are no longer using pid filtering */ |
74401729 | 7842 | synchronize_rcu(); |
e32d8956 | 7843 | |
b3b1e6ed | 7844 | if ((type & TRACE_PIDS) && pid_list) |
6954e415 | 7845 | trace_pid_list_free(pid_list); |
b3b1e6ed SRV |
7846 | |
7847 | if ((type & TRACE_NO_PIDS) && no_pid_list) | |
6954e415 | 7848 | trace_pid_list_free(no_pid_list); |
e32d8956 SR |
7849 | } |
7850 | ||
d879d0b8 NK |
7851 | void ftrace_clear_pids(struct trace_array *tr) |
7852 | { | |
7853 | mutex_lock(&ftrace_lock); | |
7854 | ||
b3b1e6ed | 7855 | clear_ftrace_pids(tr, TRACE_PIDS | TRACE_NO_PIDS); |
d879d0b8 NK |
7856 | |
7857 | mutex_unlock(&ftrace_lock); | |
7858 | } | |
7859 | ||
b3b1e6ed | 7860 | static void ftrace_pid_reset(struct trace_array *tr, int type) |
df4fc315 | 7861 | { |
756d17ee | 7862 | mutex_lock(&ftrace_lock); |
b3b1e6ed | 7863 | clear_ftrace_pids(tr, type); |
978f3a45 | 7864 | |
756d17ee | 7865 | ftrace_update_pid_func(); |
e1effa01 | 7866 | ftrace_startup_all(0); |
756d17ee | 7867 | |
7868 | mutex_unlock(&ftrace_lock); | |
756d17ee | 7869 | } |
7870 | ||
345ddcc8 SRRH |
7871 | /* Greater than any max PID */ |
7872 | #define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1) | |
df4fc315 | 7873 | |
756d17ee | 7874 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
345ddcc8 | 7875 | __acquires(RCU) |
756d17ee | 7876 | { |
345ddcc8 SRRH |
7877 | struct trace_pid_list *pid_list; |
7878 | struct trace_array *tr = m->private; | |
7879 | ||
756d17ee | 7880 | mutex_lock(&ftrace_lock); |
345ddcc8 SRRH |
7881 | rcu_read_lock_sched(); |
7882 | ||
7883 | pid_list = rcu_dereference_sched(tr->function_pids); | |
756d17ee | 7884 | |
345ddcc8 SRRH |
7885 | if (!pid_list) |
7886 | return !(*pos) ? FTRACE_NO_PIDS : NULL; | |
756d17ee | 7887 | |
345ddcc8 | 7888 | return trace_pid_start(pid_list, pos); |
756d17ee | 7889 | } |
7890 | ||
7891 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
7892 | { | |
345ddcc8 SRRH |
7893 | struct trace_array *tr = m->private; |
7894 | struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids); | |
7895 | ||
e4075e8b VA |
7896 | if (v == FTRACE_NO_PIDS) { |
7897 | (*pos)++; | |
756d17ee | 7898 | return NULL; |
e4075e8b | 7899 | } |
345ddcc8 | 7900 | return trace_pid_next(pid_list, v, pos); |
756d17ee | 7901 | } |
7902 | ||
7903 | static void fpid_stop(struct seq_file *m, void *p) | |
345ddcc8 | 7904 | __releases(RCU) |
756d17ee | 7905 | { |
345ddcc8 | 7906 | rcu_read_unlock_sched(); |
756d17ee | 7907 | mutex_unlock(&ftrace_lock); |
7908 | } | |
7909 | ||
7910 | static int fpid_show(struct seq_file *m, void *v) | |
7911 | { | |
345ddcc8 | 7912 | if (v == FTRACE_NO_PIDS) { |
fa6f0cc7 | 7913 | seq_puts(m, "no pid\n"); |
756d17ee | 7914 | return 0; |
7915 | } | |
7916 | ||
345ddcc8 | 7917 | return trace_pid_show(m, v); |
756d17ee | 7918 | } |
7919 | ||
7920 | static const struct seq_operations ftrace_pid_sops = { | |
7921 | .start = fpid_start, | |
7922 | .next = fpid_next, | |
7923 | .stop = fpid_stop, | |
7924 | .show = fpid_show, | |
7925 | }; | |
7926 | ||
b3b1e6ed SRV |
7927 | static void *fnpid_start(struct seq_file *m, loff_t *pos) |
7928 | __acquires(RCU) | |
7929 | { | |
7930 | struct trace_pid_list *pid_list; | |
7931 | struct trace_array *tr = m->private; | |
7932 | ||
7933 | mutex_lock(&ftrace_lock); | |
7934 | rcu_read_lock_sched(); | |
7935 | ||
7936 | pid_list = rcu_dereference_sched(tr->function_no_pids); | |
7937 | ||
7938 | if (!pid_list) | |
7939 | return !(*pos) ? FTRACE_NO_PIDS : NULL; | |
7940 | ||
7941 | return trace_pid_start(pid_list, pos); | |
7942 | } | |
7943 | ||
7944 | static void *fnpid_next(struct seq_file *m, void *v, loff_t *pos) | |
756d17ee | 7945 | { |
b3b1e6ed SRV |
7946 | struct trace_array *tr = m->private; |
7947 | struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_no_pids); | |
7948 | ||
7949 | if (v == FTRACE_NO_PIDS) { | |
7950 | (*pos)++; | |
7951 | return NULL; | |
7952 | } | |
7953 | return trace_pid_next(pid_list, v, pos); | |
7954 | } | |
7955 | ||
7956 | static const struct seq_operations ftrace_no_pid_sops = { | |
7957 | .start = fnpid_start, | |
7958 | .next = fnpid_next, | |
7959 | .stop = fpid_stop, | |
7960 | .show = fpid_show, | |
7961 | }; | |
7962 | ||
7963 | static int pid_open(struct inode *inode, struct file *file, int type) | |
7964 | { | |
7965 | const struct seq_operations *seq_ops; | |
345ddcc8 SRRH |
7966 | struct trace_array *tr = inode->i_private; |
7967 | struct seq_file *m; | |
756d17ee | 7968 | int ret = 0; |
7969 | ||
8530dec6 SRV |
7970 | ret = tracing_check_open_get_tr(tr); |
7971 | if (ret) | |
7972 | return ret; | |
345ddcc8 | 7973 | |
756d17ee | 7974 | if ((file->f_mode & FMODE_WRITE) && |
7975 | (file->f_flags & O_TRUNC)) | |
b3b1e6ed SRV |
7976 | ftrace_pid_reset(tr, type); |
7977 | ||
7978 | switch (type) { | |
7979 | case TRACE_PIDS: | |
7980 | seq_ops = &ftrace_pid_sops; | |
7981 | break; | |
7982 | case TRACE_NO_PIDS: | |
7983 | seq_ops = &ftrace_no_pid_sops; | |
7984 | break; | |
026bb845 KC |
7985 | default: |
7986 | trace_array_put(tr); | |
7987 | WARN_ON_ONCE(1); | |
7988 | return -EINVAL; | |
b3b1e6ed | 7989 | } |
756d17ee | 7990 | |
b3b1e6ed | 7991 | ret = seq_open(file, seq_ops); |
345ddcc8 SRRH |
7992 | if (ret < 0) { |
7993 | trace_array_put(tr); | |
7994 | } else { | |
7995 | m = file->private_data; | |
7996 | /* copy tr over to seq ops */ | |
7997 | m->private = tr; | |
7998 | } | |
756d17ee | 7999 | |
8000 | return ret; | |
8001 | } | |
8002 | ||
b3b1e6ed SRV |
8003 | static int |
8004 | ftrace_pid_open(struct inode *inode, struct file *file) | |
8005 | { | |
8006 | return pid_open(inode, file, TRACE_PIDS); | |
8007 | } | |
8008 | ||
8009 | static int | |
8010 | ftrace_no_pid_open(struct inode *inode, struct file *file) | |
8011 | { | |
8012 | return pid_open(inode, file, TRACE_NO_PIDS); | |
8013 | } | |
8014 | ||
345ddcc8 SRRH |
8015 | static void ignore_task_cpu(void *data) |
8016 | { | |
8017 | struct trace_array *tr = data; | |
8018 | struct trace_pid_list *pid_list; | |
b3b1e6ed | 8019 | struct trace_pid_list *no_pid_list; |
345ddcc8 SRRH |
8020 | |
8021 | /* | |
8022 | * This function is called by on_each_cpu() while the | |
8023 | * event_mutex is held. | |
8024 | */ | |
8025 | pid_list = rcu_dereference_protected(tr->function_pids, | |
8026 | mutex_is_locked(&ftrace_lock)); | |
b3b1e6ed SRV |
8027 | no_pid_list = rcu_dereference_protected(tr->function_no_pids, |
8028 | mutex_is_locked(&ftrace_lock)); | |
345ddcc8 | 8029 | |
b3b1e6ed | 8030 | if (trace_ignore_this_task(pid_list, no_pid_list, current)) |
717e3f5e SRV |
8031 | this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, |
8032 | FTRACE_PID_IGNORE); | |
8033 | else | |
8034 | this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, | |
8035 | current->pid); | |
345ddcc8 SRRH |
8036 | } |
8037 | ||
df4fc315 | 8038 | static ssize_t |
b3b1e6ed SRV |
8039 | pid_write(struct file *filp, const char __user *ubuf, |
8040 | size_t cnt, loff_t *ppos, int type) | |
df4fc315 | 8041 | { |
345ddcc8 SRRH |
8042 | struct seq_file *m = filp->private_data; |
8043 | struct trace_array *tr = m->private; | |
b3b1e6ed SRV |
8044 | struct trace_pid_list *filtered_pids; |
8045 | struct trace_pid_list *other_pids; | |
345ddcc8 SRRH |
8046 | struct trace_pid_list *pid_list; |
8047 | ssize_t ret; | |
df4fc315 | 8048 | |
345ddcc8 SRRH |
8049 | if (!cnt) |
8050 | return 0; | |
8051 | ||
8052 | mutex_lock(&ftrace_lock); | |
8053 | ||
b3b1e6ed SRV |
8054 | switch (type) { |
8055 | case TRACE_PIDS: | |
8056 | filtered_pids = rcu_dereference_protected(tr->function_pids, | |
345ddcc8 | 8057 | lockdep_is_held(&ftrace_lock)); |
b3b1e6ed SRV |
8058 | other_pids = rcu_dereference_protected(tr->function_no_pids, |
8059 | lockdep_is_held(&ftrace_lock)); | |
8060 | break; | |
8061 | case TRACE_NO_PIDS: | |
8062 | filtered_pids = rcu_dereference_protected(tr->function_no_pids, | |
8063 | lockdep_is_held(&ftrace_lock)); | |
8064 | other_pids = rcu_dereference_protected(tr->function_pids, | |
345ddcc8 | 8065 | lockdep_is_held(&ftrace_lock)); |
b3b1e6ed | 8066 | break; |
026bb845 KC |
8067 | default: |
8068 | ret = -EINVAL; | |
8069 | WARN_ON_ONCE(1); | |
8070 | goto out; | |
b3b1e6ed | 8071 | } |
345ddcc8 SRRH |
8072 | |
8073 | ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt); | |
8074 | if (ret < 0) | |
8075 | goto out; | |
df4fc315 | 8076 | |
b3b1e6ed SRV |
8077 | switch (type) { |
8078 | case TRACE_PIDS: | |
8079 | rcu_assign_pointer(tr->function_pids, pid_list); | |
8080 | break; | |
8081 | case TRACE_NO_PIDS: | |
8082 | rcu_assign_pointer(tr->function_no_pids, pid_list); | |
8083 | break; | |
8084 | } | |
8085 | ||
df4fc315 | 8086 | |
345ddcc8 | 8087 | if (filtered_pids) { |
74401729 | 8088 | synchronize_rcu(); |
6954e415 | 8089 | trace_pid_list_free(filtered_pids); |
b3b1e6ed | 8090 | } else if (pid_list && !other_pids) { |
345ddcc8 SRRH |
8091 | /* Register a probe to set whether to ignore the tracing of a task */ |
8092 | register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr); | |
8093 | } | |
df4fc315 | 8094 | |
756d17ee | 8095 | /* |
345ddcc8 SRRH |
8096 | * Ignoring of pids is done at task switch. But we have to |
8097 | * check for those tasks that are currently running. | |
8098 | * Always do this in case a pid was appended or removed. | |
756d17ee | 8099 | */ |
345ddcc8 | 8100 | on_each_cpu(ignore_task_cpu, tr, 1); |
756d17ee | 8101 | |
345ddcc8 SRRH |
8102 | ftrace_update_pid_func(); |
8103 | ftrace_startup_all(0); | |
8104 | out: | |
8105 | mutex_unlock(&ftrace_lock); | |
df4fc315 | 8106 | |
345ddcc8 SRRH |
8107 | if (ret > 0) |
8108 | *ppos += ret; | |
df4fc315 | 8109 | |
345ddcc8 | 8110 | return ret; |
756d17ee | 8111 | } |
df4fc315 | 8112 | |
b3b1e6ed SRV |
8113 | static ssize_t |
8114 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
8115 | size_t cnt, loff_t *ppos) | |
8116 | { | |
8117 | return pid_write(filp, ubuf, cnt, ppos, TRACE_PIDS); | |
8118 | } | |
8119 | ||
8120 | static ssize_t | |
8121 | ftrace_no_pid_write(struct file *filp, const char __user *ubuf, | |
8122 | size_t cnt, loff_t *ppos) | |
8123 | { | |
8124 | return pid_write(filp, ubuf, cnt, ppos, TRACE_NO_PIDS); | |
8125 | } | |
8126 | ||
756d17ee | 8127 | static int |
8128 | ftrace_pid_release(struct inode *inode, struct file *file) | |
8129 | { | |
345ddcc8 | 8130 | struct trace_array *tr = inode->i_private; |
df4fc315 | 8131 | |
345ddcc8 SRRH |
8132 | trace_array_put(tr); |
8133 | ||
8134 | return seq_release(inode, file); | |
df4fc315 SR |
8135 | } |
8136 | ||
5e2336a0 | 8137 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 8138 | .open = ftrace_pid_open, |
8139 | .write = ftrace_pid_write, | |
8140 | .read = seq_read, | |
098c879e | 8141 | .llseek = tracing_lseek, |
756d17ee | 8142 | .release = ftrace_pid_release, |
df4fc315 SR |
8143 | }; |
8144 | ||
b3b1e6ed SRV |
8145 | static const struct file_operations ftrace_no_pid_fops = { |
8146 | .open = ftrace_no_pid_open, | |
8147 | .write = ftrace_no_pid_write, | |
8148 | .read = seq_read, | |
8149 | .llseek = tracing_lseek, | |
8150 | .release = ftrace_pid_release, | |
8151 | }; | |
8152 | ||
345ddcc8 | 8153 | void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer) |
df4fc315 | 8154 | { |
21ccc9cd | 8155 | trace_create_file("set_ftrace_pid", TRACE_MODE_WRITE, d_tracer, |
345ddcc8 | 8156 | tr, &ftrace_pid_fops); |
21ccc9cd SRV |
8157 | trace_create_file("set_ftrace_notrace_pid", TRACE_MODE_WRITE, |
8158 | d_tracer, tr, &ftrace_no_pid_fops); | |
df4fc315 | 8159 | } |
df4fc315 | 8160 | |
501c2375 SRRH |
8161 | void __init ftrace_init_tracefs_toplevel(struct trace_array *tr, |
8162 | struct dentry *d_tracer) | |
8163 | { | |
8164 | /* Only the top level directory has the dyn_tracefs and profile */ | |
8165 | WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL)); | |
8166 | ||
8167 | ftrace_init_dyn_tracefs(d_tracer); | |
8168 | ftrace_profile_tracefs(d_tracer); | |
8169 | } | |
8170 | ||
a2bb6a3d | 8171 | /** |
81adbdc0 | 8172 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
8173 | * |
8174 | * This function should be used by panic code. It stops ftrace | |
8175 | * but in a not so nice way. If you need to simply kill ftrace | |
8176 | * from a non-atomic section, use ftrace_kill. | |
8177 | */ | |
81adbdc0 | 8178 | void ftrace_kill(void) |
a2bb6a3d SR |
8179 | { |
8180 | ftrace_disabled = 1; | |
8181 | ftrace_enabled = 0; | |
5ccba64a | 8182 | ftrace_trace_function = ftrace_stub; |
a2bb6a3d SR |
8183 | } |
8184 | ||
e0a413f6 | 8185 | /** |
6130722f SRV |
8186 | * ftrace_is_dead - Test if ftrace is dead or not. |
8187 | * | |
8188 | * Returns 1 if ftrace is "dead", zero otherwise. | |
e0a413f6 SR |
8189 | */ |
8190 | int ftrace_is_dead(void) | |
8191 | { | |
8192 | return ftrace_disabled; | |
8193 | } | |
8194 | ||
53cd885b SL |
8195 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS |
8196 | /* | |
8197 | * When registering ftrace_ops with IPMODIFY, it is necessary to make sure | |
8198 | * it doesn't conflict with any direct ftrace_ops. If there is existing | |
8199 | * direct ftrace_ops on a kernel function being patched, call | |
8200 | * FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER on it to enable sharing. | |
8201 | * | |
8202 | * @ops: ftrace_ops being registered. | |
8203 | * | |
8204 | * Returns: | |
8205 | * 0 on success; | |
8206 | * Negative on failure. | |
8207 | */ | |
8208 | static int prepare_direct_functions_for_ipmodify(struct ftrace_ops *ops) | |
8209 | { | |
8210 | struct ftrace_func_entry *entry; | |
8211 | struct ftrace_hash *hash; | |
8212 | struct ftrace_ops *op; | |
8213 | int size, i, ret; | |
8214 | ||
8215 | lockdep_assert_held_once(&direct_mutex); | |
8216 | ||
8217 | if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY)) | |
8218 | return 0; | |
8219 | ||
8220 | hash = ops->func_hash->filter_hash; | |
8221 | size = 1 << hash->size_bits; | |
8222 | for (i = 0; i < size; i++) { | |
8223 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
8224 | unsigned long ip = entry->ip; | |
8225 | bool found_op = false; | |
8226 | ||
8227 | mutex_lock(&ftrace_lock); | |
8228 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
8229 | if (!(op->flags & FTRACE_OPS_FL_DIRECT)) | |
8230 | continue; | |
8231 | if (ops_references_ip(op, ip)) { | |
8232 | found_op = true; | |
8233 | break; | |
8234 | } | |
8235 | } while_for_each_ftrace_op(op); | |
8236 | mutex_unlock(&ftrace_lock); | |
8237 | ||
8238 | if (found_op) { | |
8239 | if (!op->ops_func) | |
8240 | return -EBUSY; | |
8241 | ||
8242 | ret = op->ops_func(op, FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER); | |
8243 | if (ret) | |
8244 | return ret; | |
8245 | } | |
8246 | } | |
8247 | } | |
8248 | ||
8249 | return 0; | |
8250 | } | |
8251 | ||
8252 | /* | |
8253 | * Similar to prepare_direct_functions_for_ipmodify, clean up after ops | |
8254 | * with IPMODIFY is unregistered. The cleanup is optional for most DIRECT | |
8255 | * ops. | |
8256 | */ | |
8257 | static void cleanup_direct_functions_after_ipmodify(struct ftrace_ops *ops) | |
8258 | { | |
8259 | struct ftrace_func_entry *entry; | |
8260 | struct ftrace_hash *hash; | |
8261 | struct ftrace_ops *op; | |
8262 | int size, i; | |
8263 | ||
8264 | if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY)) | |
8265 | return; | |
8266 | ||
8267 | mutex_lock(&direct_mutex); | |
8268 | ||
8269 | hash = ops->func_hash->filter_hash; | |
8270 | size = 1 << hash->size_bits; | |
8271 | for (i = 0; i < size; i++) { | |
8272 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
8273 | unsigned long ip = entry->ip; | |
8274 | bool found_op = false; | |
8275 | ||
8276 | mutex_lock(&ftrace_lock); | |
8277 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
8278 | if (!(op->flags & FTRACE_OPS_FL_DIRECT)) | |
8279 | continue; | |
8280 | if (ops_references_ip(op, ip)) { | |
8281 | found_op = true; | |
8282 | break; | |
8283 | } | |
8284 | } while_for_each_ftrace_op(op); | |
8285 | mutex_unlock(&ftrace_lock); | |
8286 | ||
8287 | /* The cleanup is optional, ignore any errors */ | |
8288 | if (found_op && op->ops_func) | |
8289 | op->ops_func(op, FTRACE_OPS_CMD_DISABLE_SHARE_IPMODIFY_PEER); | |
8290 | } | |
8291 | } | |
8292 | mutex_unlock(&direct_mutex); | |
8293 | } | |
8294 | ||
8295 | #define lock_direct_mutex() mutex_lock(&direct_mutex) | |
8296 | #define unlock_direct_mutex() mutex_unlock(&direct_mutex) | |
8297 | ||
8298 | #else /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ | |
8299 | ||
8300 | static int prepare_direct_functions_for_ipmodify(struct ftrace_ops *ops) | |
8301 | { | |
8302 | return 0; | |
8303 | } | |
8304 | ||
8305 | static void cleanup_direct_functions_after_ipmodify(struct ftrace_ops *ops) | |
8306 | { | |
8307 | } | |
8308 | ||
8309 | #define lock_direct_mutex() do { } while (0) | |
8310 | #define unlock_direct_mutex() do { } while (0) | |
8311 | ||
8312 | #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ | |
8313 | ||
8314 | /* | |
8315 | * Similar to register_ftrace_function, except we don't lock direct_mutex. | |
8316 | */ | |
8317 | static int register_ftrace_function_nolock(struct ftrace_ops *ops) | |
8318 | { | |
8319 | int ret; | |
8320 | ||
8321 | ftrace_ops_init(ops); | |
8322 | ||
8323 | mutex_lock(&ftrace_lock); | |
8324 | ||
8325 | ret = ftrace_startup(ops, 0); | |
8326 | ||
8327 | mutex_unlock(&ftrace_lock); | |
8328 | ||
8329 | return ret; | |
8330 | } | |
8331 | ||
16444a8a | 8332 | /** |
3d083395 | 8333 | * register_ftrace_function - register a function for profiling |
78cbc651 | 8334 | * @ops: ops structure that holds the function for profiling. |
16444a8a | 8335 | * |
3d083395 SR |
8336 | * Register a function to be called by all functions in the |
8337 | * kernel. | |
8338 | * | |
8339 | * Note: @ops->func and all the functions it calls must be labeled | |
8340 | * with "notrace", otherwise it will go into a | |
8341 | * recursive loop. | |
16444a8a | 8342 | */ |
3d083395 | 8343 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 8344 | { |
3b1a8f45 | 8345 | int ret; |
4eebcc81 | 8346 | |
53cd885b SL |
8347 | lock_direct_mutex(); |
8348 | ret = prepare_direct_functions_for_ipmodify(ops); | |
8349 | if (ret < 0) | |
8350 | goto out_unlock; | |
b848914c | 8351 | |
53cd885b | 8352 | ret = register_ftrace_function_nolock(ops); |
8d240dd8 | 8353 | |
53cd885b SL |
8354 | out_unlock: |
8355 | unlock_direct_mutex(); | |
b0fc494f | 8356 | return ret; |
3d083395 | 8357 | } |
cdbe61bf | 8358 | EXPORT_SYMBOL_GPL(register_ftrace_function); |
3d083395 SR |
8359 | |
8360 | /** | |
32632920 | 8361 | * unregister_ftrace_function - unregister a function for profiling. |
78cbc651 | 8362 | * @ops: ops structure that holds the function to unregister |
3d083395 SR |
8363 | * |
8364 | * Unregister a function that was added to be called by ftrace profiling. | |
8365 | */ | |
8366 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
8367 | { | |
8368 | int ret; | |
8369 | ||
e6ea44e9 | 8370 | mutex_lock(&ftrace_lock); |
8a56d776 | 8371 | ret = ftrace_shutdown(ops, 0); |
e6ea44e9 | 8372 | mutex_unlock(&ftrace_lock); |
b0fc494f | 8373 | |
53cd885b | 8374 | cleanup_direct_functions_after_ipmodify(ops); |
b0fc494f SR |
8375 | return ret; |
8376 | } | |
cdbe61bf | 8377 | EXPORT_SYMBOL_GPL(unregister_ftrace_function); |
b0fc494f | 8378 | |
bed0d9a5 JO |
8379 | static int symbols_cmp(const void *a, const void *b) |
8380 | { | |
8381 | const char **str_a = (const char **) a; | |
8382 | const char **str_b = (const char **) b; | |
8383 | ||
8384 | return strcmp(*str_a, *str_b); | |
8385 | } | |
8386 | ||
8387 | struct kallsyms_data { | |
8388 | unsigned long *addrs; | |
8389 | const char **syms; | |
8390 | size_t cnt; | |
8391 | size_t found; | |
8392 | }; | |
8393 | ||
3640bf85 JO |
8394 | /* This function gets called for all kernel and module symbols |
8395 | * and returns 1 in case we resolved all the requested symbols, | |
8396 | * 0 otherwise. | |
8397 | */ | |
bed0d9a5 JO |
8398 | static int kallsyms_callback(void *data, const char *name, |
8399 | struct module *mod, unsigned long addr) | |
8400 | { | |
8401 | struct kallsyms_data *args = data; | |
eb1b2985 JO |
8402 | const char **sym; |
8403 | int idx; | |
bed0d9a5 | 8404 | |
eb1b2985 JO |
8405 | sym = bsearch(&name, args->syms, args->cnt, sizeof(*args->syms), symbols_cmp); |
8406 | if (!sym) | |
8407 | return 0; | |
8408 | ||
8409 | idx = sym - args->syms; | |
8410 | if (args->addrs[idx]) | |
bed0d9a5 JO |
8411 | return 0; |
8412 | ||
9d68c19c | 8413 | if (!ftrace_location(addr)) |
bed0d9a5 JO |
8414 | return 0; |
8415 | ||
eb1b2985 JO |
8416 | args->addrs[idx] = addr; |
8417 | args->found++; | |
bed0d9a5 JO |
8418 | return args->found == args->cnt ? 1 : 0; |
8419 | } | |
8420 | ||
8421 | /** | |
8422 | * ftrace_lookup_symbols - Lookup addresses for array of symbols | |
8423 | * | |
8424 | * @sorted_syms: array of symbols pointers symbols to resolve, | |
8425 | * must be alphabetically sorted | |
8426 | * @cnt: number of symbols/addresses in @syms/@addrs arrays | |
8427 | * @addrs: array for storing resulting addresses | |
8428 | * | |
8429 | * This function looks up addresses for array of symbols provided in | |
8430 | * @syms array (must be alphabetically sorted) and stores them in | |
8431 | * @addrs array, which needs to be big enough to store at least @cnt | |
8432 | * addresses. | |
8433 | * | |
8434 | * This function returns 0 if all provided symbols are found, | |
8435 | * -ESRCH otherwise. | |
8436 | */ | |
8437 | int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs) | |
8438 | { | |
8439 | struct kallsyms_data args; | |
3640bf85 | 8440 | int found_all; |
bed0d9a5 | 8441 | |
eb1b2985 | 8442 | memset(addrs, 0, sizeof(*addrs) * cnt); |
bed0d9a5 JO |
8443 | args.addrs = addrs; |
8444 | args.syms = sorted_syms; | |
8445 | args.cnt = cnt; | |
8446 | args.found = 0; | |
3640bf85 JO |
8447 | |
8448 | found_all = kallsyms_on_each_symbol(kallsyms_callback, &args); | |
8449 | if (found_all) | |
8450 | return 0; | |
07cc2c93 | 8451 | found_all = module_kallsyms_on_each_symbol(NULL, kallsyms_callback, &args); |
3640bf85 | 8452 | return found_all ? 0 : -ESRCH; |
bed0d9a5 | 8453 | } |
44d35720 | 8454 | |
5d79fa0d | 8455 | #ifdef CONFIG_SYSCTL |
8fd7c214 LC |
8456 | |
8457 | #ifdef CONFIG_DYNAMIC_FTRACE | |
f8b7d2b4 LC |
8458 | static void ftrace_startup_sysctl(void) |
8459 | { | |
8460 | int command; | |
8461 | ||
8462 | if (unlikely(ftrace_disabled)) | |
8463 | return; | |
8464 | ||
8465 | /* Force update next time */ | |
8466 | saved_ftrace_func = NULL; | |
8467 | /* ftrace_start_up is true if we want ftrace running */ | |
8468 | if (ftrace_start_up) { | |
8469 | command = FTRACE_UPDATE_CALLS; | |
8470 | if (ftrace_graph_active) | |
8471 | command |= FTRACE_START_FUNC_RET; | |
8472 | ftrace_startup_enable(command); | |
8473 | } | |
8474 | } | |
8475 | ||
8476 | static void ftrace_shutdown_sysctl(void) | |
8477 | { | |
8478 | int command; | |
8479 | ||
8480 | if (unlikely(ftrace_disabled)) | |
8481 | return; | |
8482 | ||
8483 | /* ftrace_start_up is true if ftrace is running */ | |
8484 | if (ftrace_start_up) { | |
8485 | command = FTRACE_DISABLE_CALLS; | |
8486 | if (ftrace_graph_active) | |
8487 | command |= FTRACE_STOP_FUNC_RET; | |
8488 | ftrace_run_update_code(command); | |
8489 | } | |
8490 | } | |
8fd7c214 LC |
8491 | #else |
8492 | # define ftrace_startup_sysctl() do { } while (0) | |
8493 | # define ftrace_shutdown_sysctl() do { } while (0) | |
8494 | #endif /* CONFIG_DYNAMIC_FTRACE */ | |
f8b7d2b4 | 8495 | |
7162431d MB |
8496 | static bool is_permanent_ops_registered(void) |
8497 | { | |
8498 | struct ftrace_ops *op; | |
8499 | ||
8500 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
8501 | if (op->flags & FTRACE_OPS_FL_PERMANENT) | |
8502 | return true; | |
8503 | } while_for_each_ftrace_op(op); | |
8504 | ||
8505 | return false; | |
8506 | } | |
8507 | ||
8e4e83b2 | 8508 | static int |
b0fc494f | 8509 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
54fa9ba5 | 8510 | void *buffer, size_t *lenp, loff_t *ppos) |
b0fc494f | 8511 | { |
45a4a237 | 8512 | int ret = -ENODEV; |
4eebcc81 | 8513 | |
e6ea44e9 | 8514 | mutex_lock(&ftrace_lock); |
b0fc494f | 8515 | |
45a4a237 SR |
8516 | if (unlikely(ftrace_disabled)) |
8517 | goto out; | |
8518 | ||
8519 | ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
b0fc494f | 8520 | |
a32c7765 | 8521 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
8522 | goto out; |
8523 | ||
b0fc494f SR |
8524 | if (ftrace_enabled) { |
8525 | ||
b0fc494f | 8526 | /* we are starting ftrace again */ |
f86f4180 CZ |
8527 | if (rcu_dereference_protected(ftrace_ops_list, |
8528 | lockdep_is_held(&ftrace_lock)) != &ftrace_list_end) | |
5000c418 | 8529 | update_ftrace_function(); |
b0fc494f | 8530 | |
524a3868 SRRH |
8531 | ftrace_startup_sysctl(); |
8532 | ||
b0fc494f | 8533 | } else { |
7162431d MB |
8534 | if (is_permanent_ops_registered()) { |
8535 | ftrace_enabled = true; | |
8536 | ret = -EBUSY; | |
8537 | goto out; | |
8538 | } | |
8539 | ||
b0fc494f SR |
8540 | /* stopping ftrace calls (just send to ftrace_stub) */ |
8541 | ftrace_trace_function = ftrace_stub; | |
8542 | ||
8543 | ftrace_shutdown_sysctl(); | |
8544 | } | |
8545 | ||
7162431d | 8546 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f | 8547 | out: |
e6ea44e9 | 8548 | mutex_unlock(&ftrace_lock); |
3d083395 | 8549 | return ret; |
16444a8a | 8550 | } |
8e4e83b2 WX |
8551 | |
8552 | static struct ctl_table ftrace_sysctls[] = { | |
8553 | { | |
8554 | .procname = "ftrace_enabled", | |
8555 | .data = &ftrace_enabled, | |
8556 | .maxlen = sizeof(int), | |
8557 | .mode = 0644, | |
8558 | .proc_handler = ftrace_enable_sysctl, | |
8559 | }, | |
8560 | {} | |
8561 | }; | |
8562 | ||
8563 | static int __init ftrace_sysctl_init(void) | |
8564 | { | |
8565 | register_sysctl_init("kernel", ftrace_sysctls); | |
8566 | return 0; | |
8567 | } | |
8568 | late_initcall(ftrace_sysctl_init); | |
8569 | #endif |