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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 | |
e11b521a | 48 | /* Flags that do not get reset */ |
6ce2c04f SRG |
49 | #define FTRACE_NOCLEAR_FLAGS (FTRACE_FL_DISABLED | FTRACE_FL_TOUCHED | \ |
50 | FTRACE_FL_MODIFIED) | |
e11b521a | 51 | |
b39181f7 SRG |
52 | #define FTRACE_INVALID_FUNCTION "__ftrace_invalid_address__" |
53 | ||
6912896e | 54 | #define FTRACE_WARN_ON(cond) \ |
0778d9ad SR |
55 | ({ \ |
56 | int ___r = cond; \ | |
57 | if (WARN_ON(___r)) \ | |
6912896e | 58 | ftrace_kill(); \ |
0778d9ad SR |
59 | ___r; \ |
60 | }) | |
6912896e SR |
61 | |
62 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
0778d9ad SR |
63 | ({ \ |
64 | int ___r = cond; \ | |
65 | if (WARN_ON_ONCE(___r)) \ | |
6912896e | 66 | ftrace_kill(); \ |
0778d9ad SR |
67 | ___r; \ |
68 | }) | |
6912896e | 69 | |
8fc0c701 | 70 | /* hash bits for specific function selection */ |
33dc9b12 SR |
71 | #define FTRACE_HASH_DEFAULT_BITS 10 |
72 | #define FTRACE_HASH_MAX_BITS 12 | |
8fc0c701 | 73 | |
f04f24fb | 74 | #ifdef CONFIG_DYNAMIC_FTRACE |
33b7f99c SRRH |
75 | #define INIT_OPS_HASH(opsname) \ |
76 | .func_hash = &opsname.local_hash, \ | |
77 | .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock), | |
f04f24fb | 78 | #else |
33b7f99c | 79 | #define INIT_OPS_HASH(opsname) |
f04f24fb MH |
80 | #endif |
81 | ||
a0572f68 SRV |
82 | enum { |
83 | FTRACE_MODIFY_ENABLE_FL = (1 << 0), | |
84 | FTRACE_MODIFY_MAY_SLEEP_FL = (1 << 1), | |
85 | }; | |
86 | ||
3306fc4a | 87 | struct ftrace_ops ftrace_list_end __read_mostly = { |
2f5f6ad9 | 88 | .func = ftrace_stub, |
a25d036d | 89 | .flags = FTRACE_OPS_FL_STUB, |
33b7f99c | 90 | INIT_OPS_HASH(ftrace_list_end) |
2f5f6ad9 SR |
91 | }; |
92 | ||
4eebcc81 SR |
93 | /* ftrace_enabled is a method to turn ftrace on or off */ |
94 | int ftrace_enabled __read_mostly; | |
5d79fa0d | 95 | static int __maybe_unused last_ftrace_enabled; |
b0fc494f | 96 | |
2f5f6ad9 SR |
97 | /* Current function tracing op */ |
98 | struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end; | |
405e1d83 SRRH |
99 | /* What to set function_trace_op to */ |
100 | static struct ftrace_ops *set_function_trace_op; | |
60a7ecf4 | 101 | |
345ddcc8 | 102 | static bool ftrace_pids_enabled(struct ftrace_ops *ops) |
e3eea140 | 103 | { |
345ddcc8 SRRH |
104 | struct trace_array *tr; |
105 | ||
106 | if (!(ops->flags & FTRACE_OPS_FL_PID) || !ops->private) | |
107 | return false; | |
108 | ||
109 | tr = ops->private; | |
110 | ||
b3b1e6ed | 111 | return tr->function_pids != NULL || tr->function_no_pids != NULL; |
e3eea140 SRRH |
112 | } |
113 | ||
114 | static void ftrace_update_trampoline(struct ftrace_ops *ops); | |
115 | ||
4eebcc81 SR |
116 | /* |
117 | * ftrace_disabled is set when an anomaly is discovered. | |
118 | * ftrace_disabled is much stronger than ftrace_enabled. | |
119 | */ | |
120 | static int ftrace_disabled __read_mostly; | |
121 | ||
3306fc4a | 122 | DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 123 | |
3306fc4a | 124 | struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = &ftrace_list_end; |
16444a8a | 125 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
3306fc4a | 126 | struct ftrace_ops global_ops; |
16444a8a | 127 | |
50c69781 | 128 | /* Defined by vmlinux.lds.h see the comment above arch_ftrace_ops_list_func for details */ |
34cdd18b SRV |
129 | void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, |
130 | struct ftrace_ops *op, struct ftrace_regs *fregs); | |
b848914c | 131 | |
cbad0fb2 MR |
132 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS |
133 | /* | |
134 | * Stub used to invoke the list ops without requiring a separate trampoline. | |
135 | */ | |
136 | const struct ftrace_ops ftrace_list_ops = { | |
137 | .func = ftrace_ops_list_func, | |
138 | .flags = FTRACE_OPS_FL_STUB, | |
139 | }; | |
140 | ||
141 | static void ftrace_ops_nop_func(unsigned long ip, unsigned long parent_ip, | |
142 | struct ftrace_ops *op, | |
143 | struct ftrace_regs *fregs) | |
144 | { | |
145 | /* do nothing */ | |
146 | } | |
147 | ||
148 | /* | |
149 | * Stub used when a call site is disabled. May be called transiently by threads | |
150 | * which have made it into ftrace_caller but haven't yet recovered the ops at | |
151 | * the point the call site is disabled. | |
152 | */ | |
153 | const struct ftrace_ops ftrace_nop_ops = { | |
154 | .func = ftrace_ops_nop_func, | |
155 | .flags = FTRACE_OPS_FL_STUB, | |
156 | }; | |
157 | #endif | |
158 | ||
f04f24fb MH |
159 | static inline void ftrace_ops_init(struct ftrace_ops *ops) |
160 | { | |
161 | #ifdef CONFIG_DYNAMIC_FTRACE | |
162 | if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) { | |
33b7f99c SRRH |
163 | mutex_init(&ops->local_hash.regex_lock); |
164 | ops->func_hash = &ops->local_hash; | |
f04f24fb MH |
165 | ops->flags |= FTRACE_OPS_FL_INITIALIZED; |
166 | } | |
167 | #endif | |
168 | } | |
169 | ||
2f5f6ad9 | 170 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, |
d19ad077 | 171 | struct ftrace_ops *op, struct ftrace_regs *fregs) |
df4fc315 | 172 | { |
345ddcc8 | 173 | struct trace_array *tr = op->private; |
717e3f5e | 174 | int pid; |
345ddcc8 | 175 | |
717e3f5e SRV |
176 | if (tr) { |
177 | pid = this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid); | |
178 | if (pid == FTRACE_PID_IGNORE) | |
179 | return; | |
180 | if (pid != FTRACE_PID_TRACE && | |
181 | pid != current->pid) | |
182 | return; | |
183 | } | |
df4fc315 | 184 | |
d19ad077 | 185 | op->saved_func(ip, parent_ip, op, fregs); |
df4fc315 SR |
186 | } |
187 | ||
405e1d83 SRRH |
188 | static void ftrace_sync_ipi(void *data) |
189 | { | |
190 | /* Probably not needed, but do it anyway */ | |
191 | smp_rmb(); | |
192 | } | |
193 | ||
00ccbf2f SRRH |
194 | static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops) |
195 | { | |
196 | /* | |
78a01feb | 197 | * If this is a dynamic or RCU ops, or we force list func, |
00ccbf2f SRRH |
198 | * then it needs to call the list anyway. |
199 | */ | |
b3a88803 PZ |
200 | if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_RCU) || |
201 | FTRACE_FORCE_LIST_FUNC) | |
00ccbf2f SRRH |
202 | return ftrace_ops_list_func; |
203 | ||
204 | return ftrace_ops_get_func(ops); | |
205 | } | |
206 | ||
2b499381 SR |
207 | static void update_ftrace_function(void) |
208 | { | |
209 | ftrace_func_t func; | |
210 | ||
f7aad4e1 SRRH |
211 | /* |
212 | * Prepare the ftrace_ops that the arch callback will use. | |
213 | * If there's only one ftrace_ops registered, the ftrace_ops_list | |
214 | * will point to the ops we want. | |
215 | */ | |
f86f4180 CZ |
216 | set_function_trace_op = rcu_dereference_protected(ftrace_ops_list, |
217 | lockdep_is_held(&ftrace_lock)); | |
f7aad4e1 SRRH |
218 | |
219 | /* If there's no ftrace_ops registered, just call the stub function */ | |
f86f4180 | 220 | if (set_function_trace_op == &ftrace_list_end) { |
f7aad4e1 SRRH |
221 | func = ftrace_stub; |
222 | ||
cdbe61bf SR |
223 | /* |
224 | * If we are at the end of the list and this ops is | |
4740974a SR |
225 | * recursion safe and not dynamic and the arch supports passing ops, |
226 | * then have the mcount trampoline call the function directly. | |
cdbe61bf | 227 | */ |
f86f4180 CZ |
228 | } else if (rcu_dereference_protected(ftrace_ops_list->next, |
229 | lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { | |
00ccbf2f | 230 | func = ftrace_ops_get_list_func(ftrace_ops_list); |
f7aad4e1 | 231 | |
2f5f6ad9 SR |
232 | } else { |
233 | /* Just use the default ftrace_ops */ | |
405e1d83 | 234 | set_function_trace_op = &ftrace_list_end; |
b848914c | 235 | func = ftrace_ops_list_func; |
2f5f6ad9 | 236 | } |
2b499381 | 237 | |
5f8bf2d2 SRRH |
238 | update_function_graph_func(); |
239 | ||
405e1d83 SRRH |
240 | /* If there's no change, then do nothing more here */ |
241 | if (ftrace_trace_function == func) | |
242 | return; | |
243 | ||
244 | /* | |
245 | * If we are using the list function, it doesn't care | |
246 | * about the function_trace_ops. | |
247 | */ | |
248 | if (func == ftrace_ops_list_func) { | |
249 | ftrace_trace_function = func; | |
250 | /* | |
251 | * Don't even bother setting function_trace_ops, | |
252 | * it would be racy to do so anyway. | |
253 | */ | |
254 | return; | |
255 | } | |
256 | ||
257 | #ifndef CONFIG_DYNAMIC_FTRACE | |
258 | /* | |
259 | * For static tracing, we need to be a bit more careful. | |
260 | * The function change takes affect immediately. Thus, | |
fdda88d3 | 261 | * we need to coordinate the setting of the function_trace_ops |
405e1d83 SRRH |
262 | * with the setting of the ftrace_trace_function. |
263 | * | |
264 | * Set the function to the list ops, which will call the | |
265 | * function we want, albeit indirectly, but it handles the | |
266 | * ftrace_ops and doesn't depend on function_trace_op. | |
267 | */ | |
268 | ftrace_trace_function = ftrace_ops_list_func; | |
269 | /* | |
270 | * Make sure all CPUs see this. Yes this is slow, but static | |
271 | * tracing is slow and nasty to have enabled. | |
272 | */ | |
e5a971d7 | 273 | synchronize_rcu_tasks_rude(); |
405e1d83 SRRH |
274 | /* Now all cpus are using the list ops. */ |
275 | function_trace_op = set_function_trace_op; | |
276 | /* Make sure the function_trace_op is visible on all CPUs */ | |
277 | smp_wmb(); | |
278 | /* Nasty way to force a rmb on all cpus */ | |
279 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
280 | /* OK, we are all set to update the ftrace_trace_function now! */ | |
281 | #endif /* !CONFIG_DYNAMIC_FTRACE */ | |
282 | ||
491d0dcf | 283 | ftrace_trace_function = func; |
491d0dcf SR |
284 | } |
285 | ||
f86f4180 CZ |
286 | static void add_ftrace_ops(struct ftrace_ops __rcu **list, |
287 | struct ftrace_ops *ops) | |
3d083395 | 288 | { |
f86f4180 CZ |
289 | rcu_assign_pointer(ops->next, *list); |
290 | ||
16444a8a | 291 | /* |
b848914c | 292 | * We are entering ops into the list but another |
16444a8a ACM |
293 | * CPU might be walking that list. We need to make sure |
294 | * the ops->next pointer is valid before another CPU sees | |
b848914c | 295 | * the ops pointer included into the list. |
16444a8a | 296 | */ |
2b499381 | 297 | rcu_assign_pointer(*list, ops); |
16444a8a ACM |
298 | } |
299 | ||
f86f4180 CZ |
300 | static int remove_ftrace_ops(struct ftrace_ops __rcu **list, |
301 | struct ftrace_ops *ops) | |
16444a8a | 302 | { |
16444a8a | 303 | struct ftrace_ops **p; |
16444a8a ACM |
304 | |
305 | /* | |
3d083395 SR |
306 | * If we are removing the last function, then simply point |
307 | * to the ftrace_stub. | |
16444a8a | 308 | */ |
f86f4180 CZ |
309 | if (rcu_dereference_protected(*list, |
310 | lockdep_is_held(&ftrace_lock)) == ops && | |
311 | rcu_dereference_protected(ops->next, | |
312 | lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { | |
2b499381 | 313 | *list = &ftrace_list_end; |
e6ea44e9 | 314 | return 0; |
16444a8a ACM |
315 | } |
316 | ||
2b499381 | 317 | for (p = list; *p != &ftrace_list_end; p = &(*p)->next) |
16444a8a ACM |
318 | if (*p == ops) |
319 | break; | |
320 | ||
e6ea44e9 SR |
321 | if (*p != ops) |
322 | return -1; | |
16444a8a ACM |
323 | |
324 | *p = (*p)->next; | |
2b499381 SR |
325 | return 0; |
326 | } | |
16444a8a | 327 | |
f3bea491 SRRH |
328 | static void ftrace_update_trampoline(struct ftrace_ops *ops); |
329 | ||
3306fc4a | 330 | int __register_ftrace_function(struct ftrace_ops *ops) |
2b499381 | 331 | { |
591dffda SRRH |
332 | if (ops->flags & FTRACE_OPS_FL_DELETED) |
333 | return -EINVAL; | |
334 | ||
b848914c SR |
335 | if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) |
336 | return -EBUSY; | |
337 | ||
06aeaaea | 338 | #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
08f6fba5 SR |
339 | /* |
340 | * If the ftrace_ops specifies SAVE_REGS, then it only can be used | |
341 | * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set. | |
342 | * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant. | |
343 | */ | |
344 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS && | |
345 | !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)) | |
346 | return -EINVAL; | |
347 | ||
348 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED) | |
349 | ops->flags |= FTRACE_OPS_FL_SAVE_REGS; | |
350 | #endif | |
7162431d MB |
351 | if (!ftrace_enabled && (ops->flags & FTRACE_OPS_FL_PERMANENT)) |
352 | return -EBUSY; | |
08f6fba5 | 353 | |
a20deb3a | 354 | if (!is_kernel_core_data((unsigned long)ops)) |
cdbe61bf SR |
355 | ops->flags |= FTRACE_OPS_FL_DYNAMIC; |
356 | ||
ba27f2bc | 357 | add_ftrace_ops(&ftrace_ops_list, ops); |
b848914c | 358 | |
e3eea140 SRRH |
359 | /* Always save the function, and reset at unregistering */ |
360 | ops->saved_func = ops->func; | |
361 | ||
345ddcc8 | 362 | if (ftrace_pids_enabled(ops)) |
e3eea140 SRRH |
363 | ops->func = ftrace_pid_func; |
364 | ||
f3bea491 SRRH |
365 | ftrace_update_trampoline(ops); |
366 | ||
2b499381 SR |
367 | if (ftrace_enabled) |
368 | update_ftrace_function(); | |
369 | ||
370 | return 0; | |
371 | } | |
372 | ||
3306fc4a | 373 | int __unregister_ftrace_function(struct ftrace_ops *ops) |
2b499381 SR |
374 | { |
375 | int ret; | |
376 | ||
b848914c SR |
377 | if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) |
378 | return -EBUSY; | |
379 | ||
ba27f2bc | 380 | ret = remove_ftrace_ops(&ftrace_ops_list, ops); |
b848914c | 381 | |
2b499381 SR |
382 | if (ret < 0) |
383 | return ret; | |
b848914c | 384 | |
491d0dcf SR |
385 | if (ftrace_enabled) |
386 | update_ftrace_function(); | |
16444a8a | 387 | |
e3eea140 SRRH |
388 | ops->func = ops->saved_func; |
389 | ||
e6ea44e9 | 390 | return 0; |
3d083395 SR |
391 | } |
392 | ||
df4fc315 SR |
393 | static void ftrace_update_pid_func(void) |
394 | { | |
e3eea140 SRRH |
395 | struct ftrace_ops *op; |
396 | ||
491d0dcf | 397 | /* Only do something if we are tracing something */ |
df4fc315 | 398 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 399 | return; |
df4fc315 | 400 | |
e3eea140 SRRH |
401 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
402 | if (op->flags & FTRACE_OPS_FL_PID) { | |
345ddcc8 SRRH |
403 | op->func = ftrace_pids_enabled(op) ? |
404 | ftrace_pid_func : op->saved_func; | |
e3eea140 SRRH |
405 | ftrace_update_trampoline(op); |
406 | } | |
407 | } while_for_each_ftrace_op(op); | |
408 | ||
491d0dcf | 409 | update_ftrace_function(); |
df4fc315 SR |
410 | } |
411 | ||
493762fc SR |
412 | #ifdef CONFIG_FUNCTION_PROFILER |
413 | struct ftrace_profile { | |
414 | struct hlist_node node; | |
415 | unsigned long ip; | |
416 | unsigned long counter; | |
0706f1c4 SR |
417 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
418 | unsigned long long time; | |
e330b3bc | 419 | unsigned long long time_squared; |
0706f1c4 | 420 | #endif |
8fc0c701 SR |
421 | }; |
422 | ||
493762fc SR |
423 | struct ftrace_profile_page { |
424 | struct ftrace_profile_page *next; | |
425 | unsigned long index; | |
426 | struct ftrace_profile records[]; | |
d61f82d0 SR |
427 | }; |
428 | ||
cafb168a SR |
429 | struct ftrace_profile_stat { |
430 | atomic_t disabled; | |
431 | struct hlist_head *hash; | |
432 | struct ftrace_profile_page *pages; | |
433 | struct ftrace_profile_page *start; | |
434 | struct tracer_stat stat; | |
435 | }; | |
436 | ||
493762fc SR |
437 | #define PROFILE_RECORDS_SIZE \ |
438 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 439 | |
493762fc SR |
440 | #define PROFILES_PER_PAGE \ |
441 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 442 | |
fb9fb015 SR |
443 | static int ftrace_profile_enabled __read_mostly; |
444 | ||
445 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
446 | static DEFINE_MUTEX(ftrace_profile_lock); |
447 | ||
cafb168a | 448 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc | 449 | |
20079ebe NK |
450 | #define FTRACE_PROFILE_HASH_BITS 10 |
451 | #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS) | |
493762fc | 452 | |
bac429f0 SR |
453 | static void * |
454 | function_stat_next(void *v, int idx) | |
455 | { | |
493762fc SR |
456 | struct ftrace_profile *rec = v; |
457 | struct ftrace_profile_page *pg; | |
bac429f0 | 458 | |
493762fc | 459 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
460 | |
461 | again: | |
0296e425 LZ |
462 | if (idx != 0) |
463 | rec++; | |
464 | ||
bac429f0 SR |
465 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
466 | pg = pg->next; | |
467 | if (!pg) | |
468 | return NULL; | |
469 | rec = &pg->records[0]; | |
493762fc SR |
470 | if (!rec->counter) |
471 | goto again; | |
bac429f0 SR |
472 | } |
473 | ||
bac429f0 SR |
474 | return rec; |
475 | } | |
476 | ||
477 | static void *function_stat_start(struct tracer_stat *trace) | |
478 | { | |
cafb168a SR |
479 | struct ftrace_profile_stat *stat = |
480 | container_of(trace, struct ftrace_profile_stat, stat); | |
481 | ||
482 | if (!stat || !stat->start) | |
483 | return NULL; | |
484 | ||
485 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
486 | } |
487 | ||
0706f1c4 SR |
488 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
489 | /* function graph compares on total time */ | |
80042c8f | 490 | static int function_stat_cmp(const void *p1, const void *p2) |
0706f1c4 | 491 | { |
80042c8f AS |
492 | const struct ftrace_profile *a = p1; |
493 | const struct ftrace_profile *b = p2; | |
0706f1c4 SR |
494 | |
495 | if (a->time < b->time) | |
496 | return -1; | |
497 | if (a->time > b->time) | |
498 | return 1; | |
499 | else | |
500 | return 0; | |
501 | } | |
502 | #else | |
503 | /* not function graph compares against hits */ | |
80042c8f | 504 | static int function_stat_cmp(const void *p1, const void *p2) |
bac429f0 | 505 | { |
80042c8f AS |
506 | const struct ftrace_profile *a = p1; |
507 | const struct ftrace_profile *b = p2; | |
bac429f0 SR |
508 | |
509 | if (a->counter < b->counter) | |
510 | return -1; | |
511 | if (a->counter > b->counter) | |
512 | return 1; | |
513 | else | |
514 | return 0; | |
515 | } | |
0706f1c4 | 516 | #endif |
bac429f0 SR |
517 | |
518 | static int function_stat_headers(struct seq_file *m) | |
519 | { | |
0706f1c4 | 520 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
fa6f0cc7 RV |
521 | seq_puts(m, " Function " |
522 | "Hit Time Avg s^2\n" | |
523 | " -------- " | |
524 | "--- ---- --- ---\n"); | |
0706f1c4 | 525 | #else |
fa6f0cc7 RV |
526 | seq_puts(m, " Function Hit\n" |
527 | " -------- ---\n"); | |
0706f1c4 | 528 | #endif |
bac429f0 SR |
529 | return 0; |
530 | } | |
531 | ||
532 | static int function_stat_show(struct seq_file *m, void *v) | |
533 | { | |
493762fc | 534 | struct ftrace_profile *rec = v; |
bac429f0 | 535 | char str[KSYM_SYMBOL_LEN]; |
3aaba20f | 536 | int ret = 0; |
0706f1c4 | 537 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
538 | static struct trace_seq s; |
539 | unsigned long long avg; | |
e330b3bc | 540 | unsigned long long stddev; |
0706f1c4 | 541 | #endif |
3aaba20f LZ |
542 | mutex_lock(&ftrace_profile_lock); |
543 | ||
544 | /* we raced with function_profile_reset() */ | |
545 | if (unlikely(rec->counter == 0)) { | |
546 | ret = -EBUSY; | |
547 | goto out; | |
548 | } | |
bac429f0 | 549 | |
8e436ca0 | 550 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e31f7939 | 551 | avg = div64_ul(rec->time, rec->counter); |
8e436ca0 UT |
552 | if (tracing_thresh && (avg < tracing_thresh)) |
553 | goto out; | |
554 | #endif | |
555 | ||
bac429f0 | 556 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
0706f1c4 SR |
557 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
558 | ||
559 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
fa6f0cc7 | 560 | seq_puts(m, " "); |
34886c8b | 561 | |
e330b3bc CD |
562 | /* Sample standard deviation (s^2) */ |
563 | if (rec->counter <= 1) | |
564 | stddev = 0; | |
565 | else { | |
52d85d76 JL |
566 | /* |
567 | * Apply Welford's method: | |
568 | * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2) | |
569 | */ | |
570 | stddev = rec->counter * rec->time_squared - | |
571 | rec->time * rec->time; | |
572 | ||
e330b3bc CD |
573 | /* |
574 | * Divide only 1000 for ns^2 -> us^2 conversion. | |
575 | * trace_print_graph_duration will divide 1000 again. | |
576 | */ | |
e31f7939 WY |
577 | stddev = div64_ul(stddev, |
578 | rec->counter * (rec->counter - 1) * 1000); | |
e330b3bc CD |
579 | } |
580 | ||
34886c8b SR |
581 | trace_seq_init(&s); |
582 | trace_print_graph_duration(rec->time, &s); | |
583 | trace_seq_puts(&s, " "); | |
584 | trace_print_graph_duration(avg, &s); | |
e330b3bc CD |
585 | trace_seq_puts(&s, " "); |
586 | trace_print_graph_duration(stddev, &s); | |
0706f1c4 | 587 | trace_print_seq(m, &s); |
0706f1c4 SR |
588 | #endif |
589 | seq_putc(m, '\n'); | |
3aaba20f LZ |
590 | out: |
591 | mutex_unlock(&ftrace_profile_lock); | |
bac429f0 | 592 | |
3aaba20f | 593 | return ret; |
bac429f0 SR |
594 | } |
595 | ||
cafb168a | 596 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 597 | { |
493762fc | 598 | struct ftrace_profile_page *pg; |
bac429f0 | 599 | |
cafb168a | 600 | pg = stat->pages = stat->start; |
bac429f0 | 601 | |
493762fc SR |
602 | while (pg) { |
603 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
604 | pg->index = 0; | |
605 | pg = pg->next; | |
bac429f0 SR |
606 | } |
607 | ||
cafb168a | 608 | memset(stat->hash, 0, |
493762fc SR |
609 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
610 | } | |
bac429f0 | 611 | |
172f7ba9 | 612 | static int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
613 | { |
614 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
615 | int functions; |
616 | int pages; | |
493762fc | 617 | int i; |
bac429f0 | 618 | |
493762fc | 619 | /* If we already allocated, do nothing */ |
cafb168a | 620 | if (stat->pages) |
493762fc | 621 | return 0; |
bac429f0 | 622 | |
cafb168a SR |
623 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
624 | if (!stat->pages) | |
493762fc | 625 | return -ENOMEM; |
bac429f0 | 626 | |
318e0a73 SR |
627 | #ifdef CONFIG_DYNAMIC_FTRACE |
628 | functions = ftrace_update_tot_cnt; | |
629 | #else | |
630 | /* | |
631 | * We do not know the number of functions that exist because | |
632 | * dynamic tracing is what counts them. With past experience | |
633 | * we have around 20K functions. That should be more than enough. | |
634 | * It is highly unlikely we will execute every function in | |
635 | * the kernel. | |
636 | */ | |
637 | functions = 20000; | |
638 | #endif | |
639 | ||
cafb168a | 640 | pg = stat->start = stat->pages; |
bac429f0 | 641 | |
318e0a73 SR |
642 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
643 | ||
39e30cd1 | 644 | for (i = 1; i < pages; i++) { |
493762fc | 645 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 646 | if (!pg->next) |
318e0a73 | 647 | goto out_free; |
493762fc SR |
648 | pg = pg->next; |
649 | } | |
650 | ||
651 | return 0; | |
318e0a73 SR |
652 | |
653 | out_free: | |
654 | pg = stat->start; | |
655 | while (pg) { | |
656 | unsigned long tmp = (unsigned long)pg; | |
657 | ||
658 | pg = pg->next; | |
659 | free_page(tmp); | |
660 | } | |
661 | ||
318e0a73 SR |
662 | stat->pages = NULL; |
663 | stat->start = NULL; | |
664 | ||
665 | return -ENOMEM; | |
bac429f0 SR |
666 | } |
667 | ||
cafb168a | 668 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 669 | { |
cafb168a | 670 | struct ftrace_profile_stat *stat; |
493762fc | 671 | int size; |
bac429f0 | 672 | |
cafb168a SR |
673 | stat = &per_cpu(ftrace_profile_stats, cpu); |
674 | ||
675 | if (stat->hash) { | |
493762fc | 676 | /* If the profile is already created, simply reset it */ |
cafb168a | 677 | ftrace_profile_reset(stat); |
493762fc SR |
678 | return 0; |
679 | } | |
bac429f0 | 680 | |
493762fc SR |
681 | /* |
682 | * We are profiling all functions, but usually only a few thousand | |
683 | * functions are hit. We'll make a hash of 1024 items. | |
684 | */ | |
685 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 686 | |
6396bb22 | 687 | stat->hash = kcalloc(size, sizeof(struct hlist_head), GFP_KERNEL); |
493762fc | 688 | |
cafb168a | 689 | if (!stat->hash) |
493762fc SR |
690 | return -ENOMEM; |
691 | ||
318e0a73 | 692 | /* Preallocate the function profiling pages */ |
cafb168a SR |
693 | if (ftrace_profile_pages_init(stat) < 0) { |
694 | kfree(stat->hash); | |
695 | stat->hash = NULL; | |
493762fc SR |
696 | return -ENOMEM; |
697 | } | |
698 | ||
699 | return 0; | |
bac429f0 SR |
700 | } |
701 | ||
cafb168a SR |
702 | static int ftrace_profile_init(void) |
703 | { | |
704 | int cpu; | |
705 | int ret = 0; | |
706 | ||
c4602c1c | 707 | for_each_possible_cpu(cpu) { |
cafb168a SR |
708 | ret = ftrace_profile_init_cpu(cpu); |
709 | if (ret) | |
710 | break; | |
711 | } | |
712 | ||
713 | return ret; | |
714 | } | |
715 | ||
493762fc | 716 | /* interrupts must be disabled */ |
cafb168a SR |
717 | static struct ftrace_profile * |
718 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 719 | { |
493762fc | 720 | struct ftrace_profile *rec; |
bac429f0 | 721 | struct hlist_head *hhd; |
bac429f0 SR |
722 | unsigned long key; |
723 | ||
20079ebe | 724 | key = hash_long(ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 725 | hhd = &stat->hash[key]; |
bac429f0 SR |
726 | |
727 | if (hlist_empty(hhd)) | |
728 | return NULL; | |
729 | ||
1bb539ca | 730 | hlist_for_each_entry_rcu_notrace(rec, hhd, node) { |
bac429f0 | 731 | if (rec->ip == ip) |
493762fc SR |
732 | return rec; |
733 | } | |
734 | ||
735 | return NULL; | |
736 | } | |
737 | ||
cafb168a SR |
738 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
739 | struct ftrace_profile *rec) | |
493762fc SR |
740 | { |
741 | unsigned long key; | |
742 | ||
20079ebe | 743 | key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 744 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
745 | } |
746 | ||
318e0a73 SR |
747 | /* |
748 | * The memory is already allocated, this simply finds a new record to use. | |
749 | */ | |
493762fc | 750 | static struct ftrace_profile * |
318e0a73 | 751 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
752 | { |
753 | struct ftrace_profile *rec = NULL; | |
754 | ||
318e0a73 | 755 | /* prevent recursion (from NMIs) */ |
cafb168a | 756 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
757 | goto out; |
758 | ||
493762fc | 759 | /* |
318e0a73 SR |
760 | * Try to find the function again since an NMI |
761 | * could have added it | |
493762fc | 762 | */ |
cafb168a | 763 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 764 | if (rec) |
cafb168a | 765 | goto out; |
493762fc | 766 | |
cafb168a SR |
767 | if (stat->pages->index == PROFILES_PER_PAGE) { |
768 | if (!stat->pages->next) | |
769 | goto out; | |
770 | stat->pages = stat->pages->next; | |
bac429f0 | 771 | } |
493762fc | 772 | |
cafb168a | 773 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 774 | rec->ip = ip; |
cafb168a | 775 | ftrace_add_profile(stat, rec); |
493762fc | 776 | |
bac429f0 | 777 | out: |
cafb168a | 778 | atomic_dec(&stat->disabled); |
bac429f0 SR |
779 | |
780 | return rec; | |
781 | } | |
782 | ||
783 | static void | |
2f5f6ad9 | 784 | function_profile_call(unsigned long ip, unsigned long parent_ip, |
d19ad077 | 785 | struct ftrace_ops *ops, struct ftrace_regs *fregs) |
bac429f0 | 786 | { |
cafb168a | 787 | struct ftrace_profile_stat *stat; |
493762fc | 788 | struct ftrace_profile *rec; |
bac429f0 SR |
789 | unsigned long flags; |
790 | ||
791 | if (!ftrace_profile_enabled) | |
792 | return; | |
793 | ||
794 | local_irq_save(flags); | |
cafb168a | 795 | |
bdffd893 | 796 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 797 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
798 | goto out; |
799 | ||
800 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 801 | if (!rec) { |
318e0a73 | 802 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
803 | if (!rec) |
804 | goto out; | |
805 | } | |
bac429f0 SR |
806 | |
807 | rec->counter++; | |
808 | out: | |
809 | local_irq_restore(flags); | |
810 | } | |
811 | ||
0706f1c4 | 812 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e73e679f SRV |
813 | static bool fgraph_graph_time = true; |
814 | ||
815 | void ftrace_graph_graph_time_control(bool enable) | |
816 | { | |
817 | fgraph_graph_time = enable; | |
818 | } | |
819 | ||
0706f1c4 SR |
820 | static int profile_graph_entry(struct ftrace_graph_ent *trace) |
821 | { | |
b0e21a61 | 822 | struct ftrace_ret_stack *ret_stack; |
8861dd30 | 823 | |
a1e2e31d | 824 | function_profile_call(trace->func, 0, NULL, NULL); |
8861dd30 | 825 | |
a8f0f9e4 SRV |
826 | /* If function graph is shutting down, ret_stack can be NULL */ |
827 | if (!current->ret_stack) | |
828 | return 0; | |
829 | ||
b0e21a61 SRV |
830 | ret_stack = ftrace_graph_get_ret_stack(current, 0); |
831 | if (ret_stack) | |
832 | ret_stack->subtime = 0; | |
8861dd30 | 833 | |
0706f1c4 SR |
834 | return 1; |
835 | } | |
836 | ||
837 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
838 | { | |
b0e21a61 | 839 | struct ftrace_ret_stack *ret_stack; |
cafb168a | 840 | struct ftrace_profile_stat *stat; |
a2a16d6a | 841 | unsigned long long calltime; |
0706f1c4 | 842 | struct ftrace_profile *rec; |
cafb168a | 843 | unsigned long flags; |
0706f1c4 SR |
844 | |
845 | local_irq_save(flags); | |
bdffd893 | 846 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 847 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
848 | goto out; |
849 | ||
37e44bc5 SR |
850 | /* If the calltime was zero'd ignore it */ |
851 | if (!trace->calltime) | |
852 | goto out; | |
853 | ||
a2a16d6a SR |
854 | calltime = trace->rettime - trace->calltime; |
855 | ||
55577204 | 856 | if (!fgraph_graph_time) { |
a2a16d6a SR |
857 | |
858 | /* Append this call time to the parent time to subtract */ | |
b0e21a61 SRV |
859 | ret_stack = ftrace_graph_get_ret_stack(current, 1); |
860 | if (ret_stack) | |
861 | ret_stack->subtime += calltime; | |
a2a16d6a | 862 | |
b0e21a61 SRV |
863 | ret_stack = ftrace_graph_get_ret_stack(current, 0); |
864 | if (ret_stack && ret_stack->subtime < calltime) | |
865 | calltime -= ret_stack->subtime; | |
a2a16d6a SR |
866 | else |
867 | calltime = 0; | |
868 | } | |
869 | ||
cafb168a | 870 | rec = ftrace_find_profiled_func(stat, trace->func); |
e330b3bc | 871 | if (rec) { |
a2a16d6a | 872 | rec->time += calltime; |
e330b3bc CD |
873 | rec->time_squared += calltime * calltime; |
874 | } | |
a2a16d6a | 875 | |
cafb168a | 876 | out: |
0706f1c4 SR |
877 | local_irq_restore(flags); |
878 | } | |
879 | ||
688f7089 SRV |
880 | static struct fgraph_ops fprofiler_ops = { |
881 | .entryfunc = &profile_graph_entry, | |
882 | .retfunc = &profile_graph_return, | |
883 | }; | |
884 | ||
0706f1c4 SR |
885 | static int register_ftrace_profiler(void) |
886 | { | |
688f7089 | 887 | return register_ftrace_graph(&fprofiler_ops); |
0706f1c4 SR |
888 | } |
889 | ||
890 | static void unregister_ftrace_profiler(void) | |
891 | { | |
688f7089 | 892 | unregister_ftrace_graph(&fprofiler_ops); |
0706f1c4 SR |
893 | } |
894 | #else | |
bd38c0e6 | 895 | static struct ftrace_ops ftrace_profile_ops __read_mostly = { |
fb9fb015 | 896 | .func = function_profile_call, |
a25d036d | 897 | .flags = FTRACE_OPS_FL_INITIALIZED, |
33b7f99c | 898 | INIT_OPS_HASH(ftrace_profile_ops) |
bac429f0 SR |
899 | }; |
900 | ||
0706f1c4 SR |
901 | static int register_ftrace_profiler(void) |
902 | { | |
903 | return register_ftrace_function(&ftrace_profile_ops); | |
904 | } | |
905 | ||
906 | static void unregister_ftrace_profiler(void) | |
907 | { | |
908 | unregister_ftrace_function(&ftrace_profile_ops); | |
909 | } | |
910 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
911 | ||
bac429f0 SR |
912 | static ssize_t |
913 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
914 | size_t cnt, loff_t *ppos) | |
915 | { | |
916 | unsigned long val; | |
bac429f0 SR |
917 | int ret; |
918 | ||
22fe9b54 PH |
919 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
920 | if (ret) | |
bac429f0 SR |
921 | return ret; |
922 | ||
923 | val = !!val; | |
924 | ||
925 | mutex_lock(&ftrace_profile_lock); | |
926 | if (ftrace_profile_enabled ^ val) { | |
927 | if (val) { | |
493762fc SR |
928 | ret = ftrace_profile_init(); |
929 | if (ret < 0) { | |
930 | cnt = ret; | |
931 | goto out; | |
932 | } | |
933 | ||
0706f1c4 SR |
934 | ret = register_ftrace_profiler(); |
935 | if (ret < 0) { | |
936 | cnt = ret; | |
937 | goto out; | |
938 | } | |
bac429f0 SR |
939 | ftrace_profile_enabled = 1; |
940 | } else { | |
941 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
942 | /* |
943 | * unregister_ftrace_profiler calls stop_machine | |
74401729 | 944 | * so this acts like an synchronize_rcu. |
0f6ce3de | 945 | */ |
0706f1c4 | 946 | unregister_ftrace_profiler(); |
bac429f0 SR |
947 | } |
948 | } | |
493762fc | 949 | out: |
bac429f0 SR |
950 | mutex_unlock(&ftrace_profile_lock); |
951 | ||
cf8517cf | 952 | *ppos += cnt; |
bac429f0 SR |
953 | |
954 | return cnt; | |
955 | } | |
956 | ||
493762fc SR |
957 | static ssize_t |
958 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
959 | size_t cnt, loff_t *ppos) | |
960 | { | |
fb9fb015 | 961 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
962 | int r; |
963 | ||
964 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
965 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
966 | } | |
967 | ||
bac429f0 SR |
968 | static const struct file_operations ftrace_profile_fops = { |
969 | .open = tracing_open_generic, | |
970 | .read = ftrace_profile_read, | |
971 | .write = ftrace_profile_write, | |
6038f373 | 972 | .llseek = default_llseek, |
bac429f0 SR |
973 | }; |
974 | ||
cafb168a SR |
975 | /* used to initialize the real stat files */ |
976 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
977 | .name = "functions", |
978 | .stat_start = function_stat_start, | |
979 | .stat_next = function_stat_next, | |
980 | .stat_cmp = function_stat_cmp, | |
981 | .stat_headers = function_stat_headers, | |
982 | .stat_show = function_stat_show | |
cafb168a SR |
983 | }; |
984 | ||
8434dc93 | 985 | static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
bac429f0 | 986 | { |
cafb168a | 987 | struct ftrace_profile_stat *stat; |
cafb168a | 988 | char *name; |
bac429f0 | 989 | int ret; |
cafb168a SR |
990 | int cpu; |
991 | ||
992 | for_each_possible_cpu(cpu) { | |
993 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
994 | ||
6363c6b5 | 995 | name = kasprintf(GFP_KERNEL, "function%d", cpu); |
cafb168a SR |
996 | if (!name) { |
997 | /* | |
998 | * The files created are permanent, if something happens | |
999 | * we still do not free memory. | |
1000 | */ | |
cafb168a SR |
1001 | WARN(1, |
1002 | "Could not allocate stat file for cpu %d\n", | |
1003 | cpu); | |
1004 | return; | |
1005 | } | |
1006 | stat->stat = function_stats; | |
cafb168a SR |
1007 | stat->stat.name = name; |
1008 | ret = register_stat_tracer(&stat->stat); | |
1009 | if (ret) { | |
1010 | WARN(1, | |
1011 | "Could not register function stat for cpu %d\n", | |
1012 | cpu); | |
1013 | kfree(name); | |
1014 | return; | |
1015 | } | |
bac429f0 SR |
1016 | } |
1017 | ||
e4931b82 YW |
1018 | trace_create_file("function_profile_enabled", |
1019 | TRACE_MODE_WRITE, d_tracer, NULL, | |
1020 | &ftrace_profile_fops); | |
bac429f0 SR |
1021 | } |
1022 | ||
bac429f0 | 1023 | #else /* CONFIG_FUNCTION_PROFILER */ |
8434dc93 | 1024 | static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
bac429f0 SR |
1025 | { |
1026 | } | |
bac429f0 SR |
1027 | #endif /* CONFIG_FUNCTION_PROFILER */ |
1028 | ||
493762fc SR |
1029 | #ifdef CONFIG_DYNAMIC_FTRACE |
1030 | ||
79922b80 SRRH |
1031 | static struct ftrace_ops *removed_ops; |
1032 | ||
e1effa01 SRRH |
1033 | /* |
1034 | * Set when doing a global update, like enabling all recs or disabling them. | |
1035 | * It is not set when just updating a single ftrace_ops. | |
1036 | */ | |
1037 | static bool update_all_ops; | |
1038 | ||
493762fc SR |
1039 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
1040 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
1041 | #endif | |
1042 | ||
7b60f3d8 SRV |
1043 | struct ftrace_func_probe { |
1044 | struct ftrace_probe_ops *probe_ops; | |
1045 | struct ftrace_ops ops; | |
1046 | struct trace_array *tr; | |
1047 | struct list_head list; | |
6e444319 | 1048 | void *data; |
7b60f3d8 SRV |
1049 | int ref; |
1050 | }; | |
1051 | ||
33dc9b12 SR |
1052 | /* |
1053 | * We make these constant because no one should touch them, | |
1054 | * but they are used as the default "empty hash", to avoid allocating | |
1055 | * it all the time. These are in a read only section such that if | |
1056 | * anyone does try to modify it, it will cause an exception. | |
1057 | */ | |
1058 | static const struct hlist_head empty_buckets[1]; | |
1059 | static const struct ftrace_hash empty_hash = { | |
1060 | .buckets = (struct hlist_head *)empty_buckets, | |
1cf41dd7 | 1061 | }; |
33dc9b12 | 1062 | #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash) |
493762fc | 1063 | |
3306fc4a | 1064 | struct ftrace_ops global_ops = { |
33b7f99c SRRH |
1065 | .func = ftrace_stub, |
1066 | .local_hash.notrace_hash = EMPTY_HASH, | |
1067 | .local_hash.filter_hash = EMPTY_HASH, | |
1068 | INIT_OPS_HASH(global_ops) | |
a25d036d | 1069 | .flags = FTRACE_OPS_FL_INITIALIZED | |
e3eea140 | 1070 | FTRACE_OPS_FL_PID, |
f45948e8 SR |
1071 | }; |
1072 | ||
aec0be2d | 1073 | /* |
f2cc020d | 1074 | * Used by the stack unwinder to know about dynamic ftrace trampolines. |
aec0be2d | 1075 | */ |
6be7fa3c | 1076 | struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr) |
aec0be2d | 1077 | { |
6be7fa3c | 1078 | struct ftrace_ops *op = NULL; |
aec0be2d SRRH |
1079 | |
1080 | /* | |
1081 | * Some of the ops may be dynamically allocated, | |
74401729 | 1082 | * they are freed after a synchronize_rcu(). |
aec0be2d SRRH |
1083 | */ |
1084 | preempt_disable_notrace(); | |
1085 | ||
1086 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1087 | /* | |
1088 | * This is to check for dynamically allocated trampolines. | |
1089 | * Trampolines that are in kernel text will have | |
1090 | * core_kernel_text() return true. | |
1091 | */ | |
1092 | if (op->trampoline && op->trampoline_size) | |
1093 | if (addr >= op->trampoline && | |
1094 | addr < op->trampoline + op->trampoline_size) { | |
6be7fa3c SRV |
1095 | preempt_enable_notrace(); |
1096 | return op; | |
aec0be2d SRRH |
1097 | } |
1098 | } while_for_each_ftrace_op(op); | |
aec0be2d SRRH |
1099 | preempt_enable_notrace(); |
1100 | ||
6be7fa3c SRV |
1101 | return NULL; |
1102 | } | |
1103 | ||
1104 | /* | |
1105 | * This is used by __kernel_text_address() to return true if the | |
1106 | * address is on a dynamically allocated trampoline that would | |
1107 | * not return true for either core_kernel_text() or | |
1108 | * is_module_text_address(). | |
1109 | */ | |
1110 | bool is_ftrace_trampoline(unsigned long addr) | |
1111 | { | |
1112 | return ftrace_ops_trampoline(addr) != NULL; | |
aec0be2d SRRH |
1113 | } |
1114 | ||
493762fc SR |
1115 | struct ftrace_page { |
1116 | struct ftrace_page *next; | |
a7900875 | 1117 | struct dyn_ftrace *records; |
493762fc | 1118 | int index; |
db42523b | 1119 | int order; |
493762fc SR |
1120 | }; |
1121 | ||
a7900875 SR |
1122 | #define ENTRY_SIZE sizeof(struct dyn_ftrace) |
1123 | #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE) | |
493762fc | 1124 | |
493762fc SR |
1125 | static struct ftrace_page *ftrace_pages_start; |
1126 | static struct ftrace_page *ftrace_pages; | |
1127 | ||
2b0cce0e SRV |
1128 | static __always_inline unsigned long |
1129 | ftrace_hash_key(struct ftrace_hash *hash, unsigned long ip) | |
1130 | { | |
1131 | if (hash->size_bits > 0) | |
1132 | return hash_long(ip, hash->size_bits); | |
1133 | ||
1134 | return 0; | |
1135 | } | |
1136 | ||
2b2c279c SRV |
1137 | /* Only use this function if ftrace_hash_empty() has already been tested */ |
1138 | static __always_inline struct ftrace_func_entry * | |
1139 | __ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
b448c4e3 SR |
1140 | { |
1141 | unsigned long key; | |
1142 | struct ftrace_func_entry *entry; | |
1143 | struct hlist_head *hhd; | |
b448c4e3 | 1144 | |
2b0cce0e | 1145 | key = ftrace_hash_key(hash, ip); |
b448c4e3 SR |
1146 | hhd = &hash->buckets[key]; |
1147 | ||
1bb539ca | 1148 | hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) { |
b448c4e3 SR |
1149 | if (entry->ip == ip) |
1150 | return entry; | |
1151 | } | |
1152 | return NULL; | |
1153 | } | |
1154 | ||
2b2c279c SRV |
1155 | /** |
1156 | * ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash | |
1157 | * @hash: The hash to look at | |
1158 | * @ip: The instruction pointer to test | |
1159 | * | |
1160 | * Search a given @hash to see if a given instruction pointer (@ip) | |
1161 | * exists in it. | |
1162 | * | |
1163 | * Returns the entry that holds the @ip if found. NULL otherwise. | |
1164 | */ | |
1165 | struct ftrace_func_entry * | |
1166 | ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
1167 | { | |
1168 | if (ftrace_hash_empty(hash)) | |
1169 | return NULL; | |
1170 | ||
1171 | return __ftrace_lookup_ip(hash, ip); | |
1172 | } | |
1173 | ||
33dc9b12 SR |
1174 | static void __add_hash_entry(struct ftrace_hash *hash, |
1175 | struct ftrace_func_entry *entry) | |
b448c4e3 | 1176 | { |
b448c4e3 SR |
1177 | struct hlist_head *hhd; |
1178 | unsigned long key; | |
1179 | ||
2b0cce0e | 1180 | key = ftrace_hash_key(hash, entry->ip); |
b448c4e3 SR |
1181 | hhd = &hash->buckets[key]; |
1182 | hlist_add_head(&entry->hlist, hhd); | |
1183 | hash->count++; | |
33dc9b12 SR |
1184 | } |
1185 | ||
1186 | static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip) | |
1187 | { | |
1188 | struct ftrace_func_entry *entry; | |
1189 | ||
1190 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1191 | if (!entry) | |
1192 | return -ENOMEM; | |
1193 | ||
1194 | entry->ip = ip; | |
1195 | __add_hash_entry(hash, entry); | |
b448c4e3 SR |
1196 | |
1197 | return 0; | |
1198 | } | |
1199 | ||
1200 | static void | |
33dc9b12 | 1201 | free_hash_entry(struct ftrace_hash *hash, |
b448c4e3 SR |
1202 | struct ftrace_func_entry *entry) |
1203 | { | |
1204 | hlist_del(&entry->hlist); | |
1205 | kfree(entry); | |
1206 | hash->count--; | |
1207 | } | |
1208 | ||
33dc9b12 SR |
1209 | static void |
1210 | remove_hash_entry(struct ftrace_hash *hash, | |
1211 | struct ftrace_func_entry *entry) | |
1212 | { | |
eee8ded1 | 1213 | hlist_del_rcu(&entry->hlist); |
33dc9b12 SR |
1214 | hash->count--; |
1215 | } | |
1216 | ||
b448c4e3 SR |
1217 | static void ftrace_hash_clear(struct ftrace_hash *hash) |
1218 | { | |
1219 | struct hlist_head *hhd; | |
b67bfe0d | 1220 | struct hlist_node *tn; |
b448c4e3 SR |
1221 | struct ftrace_func_entry *entry; |
1222 | int size = 1 << hash->size_bits; | |
1223 | int i; | |
1224 | ||
33dc9b12 SR |
1225 | if (!hash->count) |
1226 | return; | |
1227 | ||
b448c4e3 SR |
1228 | for (i = 0; i < size; i++) { |
1229 | hhd = &hash->buckets[i]; | |
b67bfe0d | 1230 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) |
33dc9b12 | 1231 | free_hash_entry(hash, entry); |
b448c4e3 SR |
1232 | } |
1233 | FTRACE_WARN_ON(hash->count); | |
1234 | } | |
1235 | ||
673feb9d SRV |
1236 | static void free_ftrace_mod(struct ftrace_mod_load *ftrace_mod) |
1237 | { | |
1238 | list_del(&ftrace_mod->list); | |
1239 | kfree(ftrace_mod->module); | |
1240 | kfree(ftrace_mod->func); | |
1241 | kfree(ftrace_mod); | |
1242 | } | |
1243 | ||
1244 | static void clear_ftrace_mod_list(struct list_head *head) | |
1245 | { | |
1246 | struct ftrace_mod_load *p, *n; | |
1247 | ||
1248 | /* stack tracer isn't supported yet */ | |
1249 | if (!head) | |
1250 | return; | |
1251 | ||
1252 | mutex_lock(&ftrace_lock); | |
1253 | list_for_each_entry_safe(p, n, head, list) | |
1254 | free_ftrace_mod(p); | |
1255 | mutex_unlock(&ftrace_lock); | |
1256 | } | |
1257 | ||
33dc9b12 SR |
1258 | static void free_ftrace_hash(struct ftrace_hash *hash) |
1259 | { | |
1260 | if (!hash || hash == EMPTY_HASH) | |
1261 | return; | |
1262 | ftrace_hash_clear(hash); | |
1263 | kfree(hash->buckets); | |
1264 | kfree(hash); | |
1265 | } | |
1266 | ||
07fd5515 SR |
1267 | static void __free_ftrace_hash_rcu(struct rcu_head *rcu) |
1268 | { | |
1269 | struct ftrace_hash *hash; | |
1270 | ||
1271 | hash = container_of(rcu, struct ftrace_hash, rcu); | |
1272 | free_ftrace_hash(hash); | |
1273 | } | |
1274 | ||
1275 | static void free_ftrace_hash_rcu(struct ftrace_hash *hash) | |
1276 | { | |
1277 | if (!hash || hash == EMPTY_HASH) | |
1278 | return; | |
74401729 | 1279 | call_rcu(&hash->rcu, __free_ftrace_hash_rcu); |
07fd5515 SR |
1280 | } |
1281 | ||
8be9fbd5 MR |
1282 | /** |
1283 | * ftrace_free_filter - remove all filters for an ftrace_ops | |
1284 | * @ops - the ops to remove the filters from | |
1285 | */ | |
5500fa51 JO |
1286 | void ftrace_free_filter(struct ftrace_ops *ops) |
1287 | { | |
f04f24fb | 1288 | ftrace_ops_init(ops); |
33b7f99c SRRH |
1289 | free_ftrace_hash(ops->func_hash->filter_hash); |
1290 | free_ftrace_hash(ops->func_hash->notrace_hash); | |
5500fa51 | 1291 | } |
8be9fbd5 | 1292 | EXPORT_SYMBOL_GPL(ftrace_free_filter); |
5500fa51 | 1293 | |
33dc9b12 SR |
1294 | static struct ftrace_hash *alloc_ftrace_hash(int size_bits) |
1295 | { | |
1296 | struct ftrace_hash *hash; | |
1297 | int size; | |
1298 | ||
1299 | hash = kzalloc(sizeof(*hash), GFP_KERNEL); | |
1300 | if (!hash) | |
1301 | return NULL; | |
1302 | ||
1303 | size = 1 << size_bits; | |
47b0edcb | 1304 | hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL); |
33dc9b12 SR |
1305 | |
1306 | if (!hash->buckets) { | |
1307 | kfree(hash); | |
1308 | return NULL; | |
1309 | } | |
1310 | ||
1311 | hash->size_bits = size_bits; | |
1312 | ||
1313 | return hash; | |
1314 | } | |
1315 | ||
673feb9d SRV |
1316 | |
1317 | static int ftrace_add_mod(struct trace_array *tr, | |
1318 | const char *func, const char *module, | |
1319 | int enable) | |
1320 | { | |
1321 | struct ftrace_mod_load *ftrace_mod; | |
1322 | struct list_head *mod_head = enable ? &tr->mod_trace : &tr->mod_notrace; | |
1323 | ||
1324 | ftrace_mod = kzalloc(sizeof(*ftrace_mod), GFP_KERNEL); | |
1325 | if (!ftrace_mod) | |
1326 | return -ENOMEM; | |
1327 | ||
19ba6c8a | 1328 | INIT_LIST_HEAD(&ftrace_mod->list); |
673feb9d SRV |
1329 | ftrace_mod->func = kstrdup(func, GFP_KERNEL); |
1330 | ftrace_mod->module = kstrdup(module, GFP_KERNEL); | |
1331 | ftrace_mod->enable = enable; | |
1332 | ||
1333 | if (!ftrace_mod->func || !ftrace_mod->module) | |
1334 | goto out_free; | |
1335 | ||
1336 | list_add(&ftrace_mod->list, mod_head); | |
1337 | ||
1338 | return 0; | |
1339 | ||
1340 | out_free: | |
1341 | free_ftrace_mod(ftrace_mod); | |
1342 | ||
1343 | return -ENOMEM; | |
1344 | } | |
1345 | ||
33dc9b12 SR |
1346 | static struct ftrace_hash * |
1347 | alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) | |
1348 | { | |
1349 | struct ftrace_func_entry *entry; | |
1350 | struct ftrace_hash *new_hash; | |
33dc9b12 SR |
1351 | int size; |
1352 | int ret; | |
1353 | int i; | |
1354 | ||
1355 | new_hash = alloc_ftrace_hash(size_bits); | |
1356 | if (!new_hash) | |
1357 | return NULL; | |
1358 | ||
8c08f0d5 SRV |
1359 | if (hash) |
1360 | new_hash->flags = hash->flags; | |
1361 | ||
33dc9b12 | 1362 | /* Empty hash? */ |
06a51d93 | 1363 | if (ftrace_hash_empty(hash)) |
33dc9b12 SR |
1364 | return new_hash; |
1365 | ||
1366 | size = 1 << hash->size_bits; | |
1367 | for (i = 0; i < size; i++) { | |
b67bfe0d | 1368 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { |
33dc9b12 SR |
1369 | ret = add_hash_entry(new_hash, entry->ip); |
1370 | if (ret < 0) | |
1371 | goto free_hash; | |
1372 | } | |
1373 | } | |
1374 | ||
1375 | FTRACE_WARN_ON(new_hash->count != hash->count); | |
1376 | ||
1377 | return new_hash; | |
1378 | ||
1379 | free_hash: | |
1380 | free_ftrace_hash(new_hash); | |
1381 | return NULL; | |
1382 | } | |
1383 | ||
41fb61c2 | 1384 | static void |
84261912 | 1385 | ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash); |
41fb61c2 | 1386 | static void |
84261912 | 1387 | ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash); |
41fb61c2 | 1388 | |
f8b8be8a MH |
1389 | static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, |
1390 | struct ftrace_hash *new_hash); | |
1391 | ||
714641c3 | 1392 | static struct ftrace_hash *dup_hash(struct ftrace_hash *src, int size) |
33dc9b12 SR |
1393 | { |
1394 | struct ftrace_func_entry *entry; | |
07fd5515 | 1395 | struct ftrace_hash *new_hash; |
714641c3 SRV |
1396 | struct hlist_head *hhd; |
1397 | struct hlist_node *tn; | |
33dc9b12 SR |
1398 | int bits = 0; |
1399 | int i; | |
1400 | ||
33dc9b12 | 1401 | /* |
be493132 SRV |
1402 | * Use around half the size (max bit of it), but |
1403 | * a minimum of 2 is fine (as size of 0 or 1 both give 1 for bits). | |
33dc9b12 | 1404 | */ |
be493132 | 1405 | bits = fls(size / 2); |
33dc9b12 SR |
1406 | |
1407 | /* Don't allocate too much */ | |
1408 | if (bits > FTRACE_HASH_MAX_BITS) | |
1409 | bits = FTRACE_HASH_MAX_BITS; | |
1410 | ||
07fd5515 SR |
1411 | new_hash = alloc_ftrace_hash(bits); |
1412 | if (!new_hash) | |
3e278c0d | 1413 | return NULL; |
33dc9b12 | 1414 | |
8c08f0d5 SRV |
1415 | new_hash->flags = src->flags; |
1416 | ||
33dc9b12 SR |
1417 | size = 1 << src->size_bits; |
1418 | for (i = 0; i < size; i++) { | |
1419 | hhd = &src->buckets[i]; | |
b67bfe0d | 1420 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) { |
33dc9b12 | 1421 | remove_hash_entry(src, entry); |
07fd5515 | 1422 | __add_hash_entry(new_hash, entry); |
33dc9b12 SR |
1423 | } |
1424 | } | |
3e278c0d NK |
1425 | return new_hash; |
1426 | } | |
1427 | ||
714641c3 SRV |
1428 | static struct ftrace_hash * |
1429 | __ftrace_hash_move(struct ftrace_hash *src) | |
1430 | { | |
1431 | int size = src->count; | |
1432 | ||
1433 | /* | |
1434 | * If the new source is empty, just return the empty_hash. | |
1435 | */ | |
1436 | if (ftrace_hash_empty(src)) | |
1437 | return EMPTY_HASH; | |
1438 | ||
1439 | return dup_hash(src, size); | |
1440 | } | |
1441 | ||
3e278c0d NK |
1442 | static int |
1443 | ftrace_hash_move(struct ftrace_ops *ops, int enable, | |
1444 | struct ftrace_hash **dst, struct ftrace_hash *src) | |
1445 | { | |
1446 | struct ftrace_hash *new_hash; | |
1447 | int ret; | |
1448 | ||
1449 | /* Reject setting notrace hash on IPMODIFY ftrace_ops */ | |
1450 | if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable) | |
1451 | return -EINVAL; | |
1452 | ||
1453 | new_hash = __ftrace_hash_move(src); | |
1454 | if (!new_hash) | |
1455 | return -ENOMEM; | |
1456 | ||
f8b8be8a MH |
1457 | /* Make sure this can be applied if it is IPMODIFY ftrace_ops */ |
1458 | if (enable) { | |
1459 | /* IPMODIFY should be updated only when filter_hash updating */ | |
1460 | ret = ftrace_hash_ipmodify_update(ops, new_hash); | |
1461 | if (ret < 0) { | |
1462 | free_ftrace_hash(new_hash); | |
1463 | return ret; | |
1464 | } | |
1465 | } | |
1466 | ||
5c27c775 MH |
1467 | /* |
1468 | * Remove the current set, update the hash and add | |
1469 | * them back. | |
1470 | */ | |
84261912 | 1471 | ftrace_hash_rec_disable_modify(ops, enable); |
5c27c775 | 1472 | |
07fd5515 | 1473 | rcu_assign_pointer(*dst, new_hash); |
07fd5515 | 1474 | |
84261912 | 1475 | ftrace_hash_rec_enable_modify(ops, enable); |
41fb61c2 | 1476 | |
5c27c775 | 1477 | return 0; |
33dc9b12 SR |
1478 | } |
1479 | ||
fef5aeee SRRH |
1480 | static bool hash_contains_ip(unsigned long ip, |
1481 | struct ftrace_ops_hash *hash) | |
1482 | { | |
1483 | /* | |
1484 | * The function record is a match if it exists in the filter | |
fdda88d3 | 1485 | * hash and not in the notrace hash. Note, an empty hash is |
fef5aeee SRRH |
1486 | * considered a match for the filter hash, but an empty |
1487 | * notrace hash is considered not in the notrace hash. | |
1488 | */ | |
1489 | return (ftrace_hash_empty(hash->filter_hash) || | |
2b2c279c | 1490 | __ftrace_lookup_ip(hash->filter_hash, ip)) && |
fef5aeee | 1491 | (ftrace_hash_empty(hash->notrace_hash) || |
2b2c279c | 1492 | !__ftrace_lookup_ip(hash->notrace_hash, ip)); |
fef5aeee SRRH |
1493 | } |
1494 | ||
b848914c SR |
1495 | /* |
1496 | * Test the hashes for this ops to see if we want to call | |
1497 | * the ops->func or not. | |
1498 | * | |
1499 | * It's a match if the ip is in the ops->filter_hash or | |
1500 | * the filter_hash does not exist or is empty, | |
1501 | * AND | |
1502 | * the ip is not in the ops->notrace_hash. | |
cdbe61bf SR |
1503 | * |
1504 | * This needs to be called with preemption disabled as | |
74401729 | 1505 | * the hashes are freed with call_rcu(). |
b848914c | 1506 | */ |
3306fc4a | 1507 | int |
195a8afc | 1508 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
b848914c | 1509 | { |
fef5aeee | 1510 | struct ftrace_ops_hash hash; |
b848914c SR |
1511 | int ret; |
1512 | ||
195a8afc SRRH |
1513 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
1514 | /* | |
1515 | * There's a small race when adding ops that the ftrace handler | |
1516 | * that wants regs, may be called without them. We can not | |
1517 | * allow that handler to be called if regs is NULL. | |
1518 | */ | |
1519 | if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS)) | |
1520 | return 0; | |
1521 | #endif | |
1522 | ||
f86f4180 CZ |
1523 | rcu_assign_pointer(hash.filter_hash, ops->func_hash->filter_hash); |
1524 | rcu_assign_pointer(hash.notrace_hash, ops->func_hash->notrace_hash); | |
b848914c | 1525 | |
fef5aeee | 1526 | if (hash_contains_ip(ip, &hash)) |
b848914c SR |
1527 | ret = 1; |
1528 | else | |
1529 | ret = 0; | |
b848914c SR |
1530 | |
1531 | return ret; | |
1532 | } | |
1533 | ||
493762fc SR |
1534 | /* |
1535 | * This is a double for. Do not use 'break' to break out of the loop, | |
1536 | * you must use a goto. | |
1537 | */ | |
1538 | #define do_for_each_ftrace_rec(pg, rec) \ | |
1539 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
1540 | int _____i; \ | |
1541 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
1542 | rec = &pg->records[_____i]; | |
1543 | ||
1544 | #define while_for_each_ftrace_rec() \ | |
1545 | } \ | |
1546 | } | |
1547 | ||
5855fead SR |
1548 | |
1549 | static int ftrace_cmp_recs(const void *a, const void *b) | |
1550 | { | |
a650e02a SR |
1551 | const struct dyn_ftrace *key = a; |
1552 | const struct dyn_ftrace *rec = b; | |
5855fead | 1553 | |
a650e02a | 1554 | if (key->flags < rec->ip) |
5855fead | 1555 | return -1; |
a650e02a SR |
1556 | if (key->ip >= rec->ip + MCOUNT_INSN_SIZE) |
1557 | return 1; | |
5855fead SR |
1558 | return 0; |
1559 | } | |
1560 | ||
7e16f581 SRV |
1561 | static struct dyn_ftrace *lookup_rec(unsigned long start, unsigned long end) |
1562 | { | |
1563 | struct ftrace_page *pg; | |
1564 | struct dyn_ftrace *rec = NULL; | |
1565 | struct dyn_ftrace key; | |
1566 | ||
1567 | key.ip = start; | |
1568 | key.flags = end; /* overload flags, as it is unsigned long */ | |
1569 | ||
1570 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
ee92fa44 CZ |
1571 | if (pg->index == 0 || |
1572 | end < pg->records[0].ip || | |
7e16f581 SRV |
1573 | start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) |
1574 | continue; | |
1575 | rec = bsearch(&key, pg->records, pg->index, | |
1576 | sizeof(struct dyn_ftrace), | |
1577 | ftrace_cmp_recs); | |
d9815bff AS |
1578 | if (rec) |
1579 | break; | |
7e16f581 SRV |
1580 | } |
1581 | return rec; | |
1582 | } | |
1583 | ||
04cf31a7 ME |
1584 | /** |
1585 | * ftrace_location_range - return the first address of a traced location | |
1586 | * if it touches the given ip range | |
1587 | * @start: start of range to search. | |
1588 | * @end: end of range to search (inclusive). @end points to the last byte | |
1589 | * to check. | |
1590 | * | |
1591 | * Returns rec->ip if the related ftrace location is a least partly within | |
1592 | * the given address range. That is, the first address of the instruction | |
1593 | * that is either a NOP or call to the function tracer. It checks the ftrace | |
1594 | * internal tables to determine if the address belongs or not. | |
1595 | */ | |
1596 | unsigned long ftrace_location_range(unsigned long start, unsigned long end) | |
c88fd863 | 1597 | { |
c88fd863 | 1598 | struct dyn_ftrace *rec; |
5855fead | 1599 | |
7e16f581 SRV |
1600 | rec = lookup_rec(start, end); |
1601 | if (rec) | |
1602 | return rec->ip; | |
c88fd863 SR |
1603 | |
1604 | return 0; | |
1605 | } | |
1606 | ||
a650e02a | 1607 | /** |
aebfd125 | 1608 | * ftrace_location - return the ftrace location |
a650e02a SR |
1609 | * @ip: the instruction pointer to check |
1610 | * | |
aebfd125 PZ |
1611 | * If @ip matches the ftrace location, return @ip. |
1612 | * If @ip matches sym+0, return sym's ftrace location. | |
1613 | * Otherwise, return 0. | |
a650e02a | 1614 | */ |
f0cf973a | 1615 | unsigned long ftrace_location(unsigned long ip) |
a650e02a | 1616 | { |
aebfd125 PZ |
1617 | struct dyn_ftrace *rec; |
1618 | unsigned long offset; | |
1619 | unsigned long size; | |
1620 | ||
1621 | rec = lookup_rec(ip, ip); | |
1622 | if (!rec) { | |
1623 | if (!kallsyms_lookup_size_offset(ip, &size, &offset)) | |
1624 | goto out; | |
1625 | ||
1626 | /* map sym+0 to __fentry__ */ | |
1627 | if (!offset) | |
1628 | rec = lookup_rec(ip, ip + size - 1); | |
1629 | } | |
1630 | ||
1631 | if (rec) | |
1632 | return rec->ip; | |
1633 | ||
1634 | out: | |
1635 | return 0; | |
a650e02a SR |
1636 | } |
1637 | ||
1638 | /** | |
1639 | * ftrace_text_reserved - return true if range contains an ftrace location | |
1640 | * @start: start of range to search | |
1641 | * @end: end of range to search (inclusive). @end points to the last byte to check. | |
1642 | * | |
1643 | * Returns 1 if @start and @end contains a ftrace location. | |
1644 | * That is, the instruction that is either a NOP or call to | |
1645 | * the function tracer. It checks the ftrace internal tables to | |
1646 | * determine if the address belongs or not. | |
1647 | */ | |
d88471cb | 1648 | int ftrace_text_reserved(const void *start, const void *end) |
a650e02a | 1649 | { |
f0cf973a SR |
1650 | unsigned long ret; |
1651 | ||
1652 | ret = ftrace_location_range((unsigned long)start, | |
1653 | (unsigned long)end); | |
1654 | ||
1655 | return (int)!!ret; | |
a650e02a SR |
1656 | } |
1657 | ||
4fbb48cb SRRH |
1658 | /* Test if ops registered to this rec needs regs */ |
1659 | static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec) | |
1660 | { | |
1661 | struct ftrace_ops *ops; | |
1662 | bool keep_regs = false; | |
1663 | ||
1664 | for (ops = ftrace_ops_list; | |
1665 | ops != &ftrace_list_end; ops = ops->next) { | |
1666 | /* pass rec in as regs to have non-NULL val */ | |
1667 | if (ftrace_ops_test(ops, rec->ip, rec)) { | |
1668 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1669 | keep_regs = true; | |
1670 | break; | |
1671 | } | |
1672 | } | |
1673 | } | |
1674 | ||
1675 | return keep_regs; | |
1676 | } | |
1677 | ||
a124692b CJ |
1678 | static struct ftrace_ops * |
1679 | ftrace_find_tramp_ops_any(struct dyn_ftrace *rec); | |
1680 | static struct ftrace_ops * | |
4c75b0ff NR |
1681 | ftrace_find_tramp_ops_any_other(struct dyn_ftrace *rec, struct ftrace_ops *op_exclude); |
1682 | static struct ftrace_ops * | |
a124692b CJ |
1683 | ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops); |
1684 | ||
cf04f2d5 SRG |
1685 | static bool skip_record(struct dyn_ftrace *rec) |
1686 | { | |
1687 | /* | |
1688 | * At boot up, weak functions are set to disable. Function tracing | |
1689 | * can be enabled before they are, and they still need to be disabled now. | |
1690 | * If the record is disabled, still continue if it is marked as already | |
1691 | * enabled (this is needed to keep the accounting working). | |
1692 | */ | |
1693 | return rec->flags & FTRACE_FL_DISABLED && | |
1694 | !(rec->flags & FTRACE_FL_ENABLED); | |
1695 | } | |
1696 | ||
84b6d3e6 | 1697 | static bool __ftrace_hash_rec_update(struct ftrace_ops *ops, |
ed926f9b SR |
1698 | int filter_hash, |
1699 | bool inc) | |
1700 | { | |
1701 | struct ftrace_hash *hash; | |
1702 | struct ftrace_hash *other_hash; | |
1703 | struct ftrace_page *pg; | |
1704 | struct dyn_ftrace *rec; | |
84b6d3e6 | 1705 | bool update = false; |
ed926f9b | 1706 | int count = 0; |
8c08f0d5 | 1707 | int all = false; |
ed926f9b SR |
1708 | |
1709 | /* Only update if the ops has been registered */ | |
1710 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
84b6d3e6 | 1711 | return false; |
ed926f9b SR |
1712 | |
1713 | /* | |
1714 | * In the filter_hash case: | |
1715 | * If the count is zero, we update all records. | |
1716 | * Otherwise we just update the items in the hash. | |
1717 | * | |
1718 | * In the notrace_hash case: | |
1719 | * We enable the update in the hash. | |
1720 | * As disabling notrace means enabling the tracing, | |
1721 | * and enabling notrace means disabling, the inc variable | |
1722 | * gets inversed. | |
1723 | */ | |
1724 | if (filter_hash) { | |
33b7f99c SRRH |
1725 | hash = ops->func_hash->filter_hash; |
1726 | other_hash = ops->func_hash->notrace_hash; | |
06a51d93 | 1727 | if (ftrace_hash_empty(hash)) |
8c08f0d5 | 1728 | all = true; |
ed926f9b SR |
1729 | } else { |
1730 | inc = !inc; | |
33b7f99c SRRH |
1731 | hash = ops->func_hash->notrace_hash; |
1732 | other_hash = ops->func_hash->filter_hash; | |
ed926f9b SR |
1733 | /* |
1734 | * If the notrace hash has no items, | |
1735 | * then there's nothing to do. | |
1736 | */ | |
06a51d93 | 1737 | if (ftrace_hash_empty(hash)) |
84b6d3e6 | 1738 | return false; |
ed926f9b SR |
1739 | } |
1740 | ||
1741 | do_for_each_ftrace_rec(pg, rec) { | |
1742 | int in_other_hash = 0; | |
1743 | int in_hash = 0; | |
1744 | int match = 0; | |
1745 | ||
cf04f2d5 | 1746 | if (skip_record(rec)) |
b7ffffbb SRRH |
1747 | continue; |
1748 | ||
ed926f9b SR |
1749 | if (all) { |
1750 | /* | |
1751 | * Only the filter_hash affects all records. | |
1752 | * Update if the record is not in the notrace hash. | |
1753 | */ | |
b848914c | 1754 | if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) |
ed926f9b SR |
1755 | match = 1; |
1756 | } else { | |
06a51d93 SR |
1757 | in_hash = !!ftrace_lookup_ip(hash, rec->ip); |
1758 | in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip); | |
ed926f9b SR |
1759 | |
1760 | /* | |
19eab4a4 SRRH |
1761 | * If filter_hash is set, we want to match all functions |
1762 | * that are in the hash but not in the other hash. | |
ed926f9b | 1763 | * |
19eab4a4 SRRH |
1764 | * If filter_hash is not set, then we are decrementing. |
1765 | * That means we match anything that is in the hash | |
1766 | * and also in the other_hash. That is, we need to turn | |
1767 | * off functions in the other hash because they are disabled | |
1768 | * by this hash. | |
ed926f9b SR |
1769 | */ |
1770 | if (filter_hash && in_hash && !in_other_hash) | |
1771 | match = 1; | |
1772 | else if (!filter_hash && in_hash && | |
06a51d93 | 1773 | (in_other_hash || ftrace_hash_empty(other_hash))) |
ed926f9b SR |
1774 | match = 1; |
1775 | } | |
1776 | if (!match) | |
1777 | continue; | |
1778 | ||
1779 | if (inc) { | |
1780 | rec->flags++; | |
0376bde1 | 1781 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX)) |
84b6d3e6 | 1782 | return false; |
79922b80 | 1783 | |
763e34e7 SRV |
1784 | if (ops->flags & FTRACE_OPS_FL_DIRECT) |
1785 | rec->flags |= FTRACE_FL_DIRECT; | |
1786 | ||
79922b80 SRRH |
1787 | /* |
1788 | * If there's only a single callback registered to a | |
1789 | * function, and the ops has a trampoline registered | |
1790 | * for it, then we can call it directly. | |
1791 | */ | |
fef5aeee | 1792 | if (ftrace_rec_count(rec) == 1 && ops->trampoline) |
79922b80 | 1793 | rec->flags |= FTRACE_FL_TRAMP; |
fef5aeee | 1794 | else |
79922b80 SRRH |
1795 | /* |
1796 | * If we are adding another function callback | |
1797 | * to this function, and the previous had a | |
bce0b6c5 SRRH |
1798 | * custom trampoline in use, then we need to go |
1799 | * back to the default trampoline. | |
79922b80 | 1800 | */ |
fef5aeee | 1801 | rec->flags &= ~FTRACE_FL_TRAMP; |
79922b80 | 1802 | |
08f6fba5 SR |
1803 | /* |
1804 | * If any ops wants regs saved for this function | |
1805 | * then all ops will get saved regs. | |
1806 | */ | |
1807 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) | |
1808 | rec->flags |= FTRACE_FL_REGS; | |
ed926f9b | 1809 | } else { |
0376bde1 | 1810 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0)) |
84b6d3e6 | 1811 | return false; |
ed926f9b | 1812 | rec->flags--; |
79922b80 | 1813 | |
763e34e7 SRV |
1814 | /* |
1815 | * Only the internal direct_ops should have the | |
1816 | * DIRECT flag set. Thus, if it is removing a | |
1817 | * function, then that function should no longer | |
1818 | * be direct. | |
1819 | */ | |
1820 | if (ops->flags & FTRACE_OPS_FL_DIRECT) | |
1821 | rec->flags &= ~FTRACE_FL_DIRECT; | |
1822 | ||
4fbb48cb SRRH |
1823 | /* |
1824 | * If the rec had REGS enabled and the ops that is | |
1825 | * being removed had REGS set, then see if there is | |
1826 | * still any ops for this record that wants regs. | |
1827 | * If not, we can stop recording them. | |
1828 | */ | |
0376bde1 | 1829 | if (ftrace_rec_count(rec) > 0 && |
4fbb48cb SRRH |
1830 | rec->flags & FTRACE_FL_REGS && |
1831 | ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1832 | if (!test_rec_ops_needs_regs(rec)) | |
1833 | rec->flags &= ~FTRACE_FL_REGS; | |
1834 | } | |
79922b80 | 1835 | |
fef5aeee | 1836 | /* |
a124692b CJ |
1837 | * The TRAMP needs to be set only if rec count |
1838 | * is decremented to one, and the ops that is | |
1839 | * left has a trampoline. As TRAMP can only be | |
1840 | * enabled if there is only a single ops attached | |
1841 | * to it. | |
fef5aeee | 1842 | */ |
a124692b | 1843 | if (ftrace_rec_count(rec) == 1 && |
4c75b0ff | 1844 | ftrace_find_tramp_ops_any_other(rec, ops)) |
a124692b CJ |
1845 | rec->flags |= FTRACE_FL_TRAMP; |
1846 | else | |
1847 | rec->flags &= ~FTRACE_FL_TRAMP; | |
fef5aeee | 1848 | |
79922b80 SRRH |
1849 | /* |
1850 | * flags will be cleared in ftrace_check_record() | |
1851 | * if rec count is zero. | |
1852 | */ | |
ed926f9b | 1853 | } |
cbad0fb2 MR |
1854 | |
1855 | /* | |
1856 | * If the rec has a single associated ops, and ops->func can be | |
1857 | * called directly, allow the call site to call via the ops. | |
1858 | */ | |
1859 | if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS) && | |
1860 | ftrace_rec_count(rec) == 1 && | |
1861 | ftrace_ops_get_func(ops) == ops->func) | |
1862 | rec->flags |= FTRACE_FL_CALL_OPS; | |
1863 | else | |
1864 | rec->flags &= ~FTRACE_FL_CALL_OPS; | |
1865 | ||
ed926f9b | 1866 | count++; |
84b6d3e6 JO |
1867 | |
1868 | /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */ | |
7375dca1 | 1869 | update |= ftrace_test_record(rec, true) != FTRACE_UPDATE_IGNORE; |
84b6d3e6 | 1870 | |
ed926f9b SR |
1871 | /* Shortcut, if we handled all records, we are done. */ |
1872 | if (!all && count == hash->count) | |
84b6d3e6 | 1873 | return update; |
ed926f9b | 1874 | } while_for_each_ftrace_rec(); |
84b6d3e6 JO |
1875 | |
1876 | return update; | |
ed926f9b SR |
1877 | } |
1878 | ||
84b6d3e6 | 1879 | static bool ftrace_hash_rec_disable(struct ftrace_ops *ops, |
ed926f9b SR |
1880 | int filter_hash) |
1881 | { | |
84b6d3e6 | 1882 | return __ftrace_hash_rec_update(ops, filter_hash, 0); |
ed926f9b SR |
1883 | } |
1884 | ||
84b6d3e6 | 1885 | static bool ftrace_hash_rec_enable(struct ftrace_ops *ops, |
ed926f9b SR |
1886 | int filter_hash) |
1887 | { | |
84b6d3e6 | 1888 | return __ftrace_hash_rec_update(ops, filter_hash, 1); |
ed926f9b SR |
1889 | } |
1890 | ||
84261912 SRRH |
1891 | static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops, |
1892 | int filter_hash, int inc) | |
1893 | { | |
1894 | struct ftrace_ops *op; | |
1895 | ||
1896 | __ftrace_hash_rec_update(ops, filter_hash, inc); | |
1897 | ||
1898 | if (ops->func_hash != &global_ops.local_hash) | |
1899 | return; | |
1900 | ||
1901 | /* | |
1902 | * If the ops shares the global_ops hash, then we need to update | |
1903 | * all ops that are enabled and use this hash. | |
1904 | */ | |
1905 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1906 | /* Already done */ | |
1907 | if (op == ops) | |
1908 | continue; | |
1909 | if (op->func_hash == &global_ops.local_hash) | |
1910 | __ftrace_hash_rec_update(op, filter_hash, inc); | |
1911 | } while_for_each_ftrace_op(op); | |
1912 | } | |
1913 | ||
1914 | static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, | |
1915 | int filter_hash) | |
1916 | { | |
1917 | ftrace_hash_rec_update_modify(ops, filter_hash, 0); | |
1918 | } | |
1919 | ||
1920 | static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, | |
1921 | int filter_hash) | |
1922 | { | |
1923 | ftrace_hash_rec_update_modify(ops, filter_hash, 1); | |
1924 | } | |
1925 | ||
f8b8be8a MH |
1926 | /* |
1927 | * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK | |
1928 | * or no-needed to update, -EBUSY if it detects a conflict of the flag | |
1929 | * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs. | |
1930 | * Note that old_hash and new_hash has below meanings | |
1931 | * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected) | |
1932 | * - If the hash is EMPTY_HASH, it hits nothing | |
1933 | * - Anything else hits the recs which match the hash entries. | |
53cd885b SL |
1934 | * |
1935 | * DIRECT ops does not have IPMODIFY flag, but we still need to check it | |
1936 | * against functions with FTRACE_FL_IPMODIFY. If there is any overlap, call | |
1937 | * ops_func(SHARE_IPMODIFY_SELF) to make sure current ops can share with | |
1938 | * IPMODIFY. If ops_func(SHARE_IPMODIFY_SELF) returns non-zero, propagate | |
1939 | * the return value to the caller and eventually to the owner of the DIRECT | |
1940 | * ops. | |
f8b8be8a MH |
1941 | */ |
1942 | static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops, | |
1943 | struct ftrace_hash *old_hash, | |
1944 | struct ftrace_hash *new_hash) | |
1945 | { | |
1946 | struct ftrace_page *pg; | |
1947 | struct dyn_ftrace *rec, *end = NULL; | |
1948 | int in_old, in_new; | |
53cd885b | 1949 | bool is_ipmodify, is_direct; |
f8b8be8a MH |
1950 | |
1951 | /* Only update if the ops has been registered */ | |
1952 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
1953 | return 0; | |
1954 | ||
53cd885b SL |
1955 | is_ipmodify = ops->flags & FTRACE_OPS_FL_IPMODIFY; |
1956 | is_direct = ops->flags & FTRACE_OPS_FL_DIRECT; | |
1957 | ||
1958 | /* neither IPMODIFY nor DIRECT, skip */ | |
1959 | if (!is_ipmodify && !is_direct) | |
1960 | return 0; | |
1961 | ||
1962 | if (WARN_ON_ONCE(is_ipmodify && is_direct)) | |
f8b8be8a MH |
1963 | return 0; |
1964 | ||
1965 | /* | |
53cd885b SL |
1966 | * Since the IPMODIFY and DIRECT are very address sensitive |
1967 | * actions, we do not allow ftrace_ops to set all functions to new | |
1968 | * hash. | |
f8b8be8a MH |
1969 | */ |
1970 | if (!new_hash || !old_hash) | |
1971 | return -EINVAL; | |
1972 | ||
1973 | /* Update rec->flags */ | |
1974 | do_for_each_ftrace_rec(pg, rec) { | |
546fece4 SRRH |
1975 | |
1976 | if (rec->flags & FTRACE_FL_DISABLED) | |
1977 | continue; | |
1978 | ||
f8b8be8a MH |
1979 | /* We need to update only differences of filter_hash */ |
1980 | in_old = !!ftrace_lookup_ip(old_hash, rec->ip); | |
1981 | in_new = !!ftrace_lookup_ip(new_hash, rec->ip); | |
1982 | if (in_old == in_new) | |
1983 | continue; | |
1984 | ||
1985 | if (in_new) { | |
53cd885b SL |
1986 | if (rec->flags & FTRACE_FL_IPMODIFY) { |
1987 | int ret; | |
1988 | ||
1989 | /* Cannot have two ipmodify on same rec */ | |
1990 | if (is_ipmodify) | |
1991 | goto rollback; | |
1992 | ||
1993 | FTRACE_WARN_ON(rec->flags & FTRACE_FL_DIRECT); | |
1994 | ||
1995 | /* | |
1996 | * Another ops with IPMODIFY is already | |
1997 | * attached. We are now attaching a direct | |
1998 | * ops. Run SHARE_IPMODIFY_SELF, to check | |
1999 | * whether sharing is supported. | |
2000 | */ | |
2001 | if (!ops->ops_func) | |
2002 | return -EBUSY; | |
2003 | ret = ops->ops_func(ops, FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_SELF); | |
2004 | if (ret) | |
2005 | return ret; | |
2006 | } else if (is_ipmodify) { | |
2007 | rec->flags |= FTRACE_FL_IPMODIFY; | |
2008 | } | |
2009 | } else if (is_ipmodify) { | |
f8b8be8a | 2010 | rec->flags &= ~FTRACE_FL_IPMODIFY; |
53cd885b | 2011 | } |
f8b8be8a MH |
2012 | } while_for_each_ftrace_rec(); |
2013 | ||
2014 | return 0; | |
2015 | ||
2016 | rollback: | |
2017 | end = rec; | |
2018 | ||
2019 | /* Roll back what we did above */ | |
2020 | do_for_each_ftrace_rec(pg, rec) { | |
546fece4 SRRH |
2021 | |
2022 | if (rec->flags & FTRACE_FL_DISABLED) | |
2023 | continue; | |
2024 | ||
f8b8be8a MH |
2025 | if (rec == end) |
2026 | goto err_out; | |
2027 | ||
2028 | in_old = !!ftrace_lookup_ip(old_hash, rec->ip); | |
2029 | in_new = !!ftrace_lookup_ip(new_hash, rec->ip); | |
2030 | if (in_old == in_new) | |
2031 | continue; | |
2032 | ||
2033 | if (in_new) | |
2034 | rec->flags &= ~FTRACE_FL_IPMODIFY; | |
2035 | else | |
2036 | rec->flags |= FTRACE_FL_IPMODIFY; | |
2037 | } while_for_each_ftrace_rec(); | |
2038 | ||
2039 | err_out: | |
2040 | return -EBUSY; | |
2041 | } | |
2042 | ||
2043 | static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops) | |
2044 | { | |
2045 | struct ftrace_hash *hash = ops->func_hash->filter_hash; | |
2046 | ||
2047 | if (ftrace_hash_empty(hash)) | |
2048 | hash = NULL; | |
2049 | ||
2050 | return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash); | |
2051 | } | |
2052 | ||
2053 | /* Disabling always succeeds */ | |
2054 | static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops) | |
2055 | { | |
2056 | struct ftrace_hash *hash = ops->func_hash->filter_hash; | |
2057 | ||
2058 | if (ftrace_hash_empty(hash)) | |
2059 | hash = NULL; | |
2060 | ||
2061 | __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH); | |
2062 | } | |
2063 | ||
2064 | static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, | |
2065 | struct ftrace_hash *new_hash) | |
2066 | { | |
2067 | struct ftrace_hash *old_hash = ops->func_hash->filter_hash; | |
2068 | ||
2069 | if (ftrace_hash_empty(old_hash)) | |
2070 | old_hash = NULL; | |
2071 | ||
2072 | if (ftrace_hash_empty(new_hash)) | |
2073 | new_hash = NULL; | |
2074 | ||
2075 | return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash); | |
2076 | } | |
2077 | ||
b05086c7 | 2078 | static void print_ip_ins(const char *fmt, const unsigned char *p) |
b17e8a37 | 2079 | { |
6c14133d | 2080 | char ins[MCOUNT_INSN_SIZE]; |
b17e8a37 | 2081 | |
6c14133d SRV |
2082 | if (copy_from_kernel_nofault(ins, p, MCOUNT_INSN_SIZE)) { |
2083 | printk(KERN_CONT "%s[FAULT] %px\n", fmt, p); | |
2084 | return; | |
2085 | } | |
2086 | ||
b17e8a37 | 2087 | printk(KERN_CONT "%s", fmt); |
30f7d1ca | 2088 | pr_cont("%*phC", MCOUNT_INSN_SIZE, ins); |
b17e8a37 SR |
2089 | } |
2090 | ||
02a392a0 | 2091 | enum ftrace_bug_type ftrace_bug_type; |
b05086c7 | 2092 | const void *ftrace_expected; |
02a392a0 SRRH |
2093 | |
2094 | static void print_bug_type(void) | |
2095 | { | |
2096 | switch (ftrace_bug_type) { | |
2097 | case FTRACE_BUG_UNKNOWN: | |
2098 | break; | |
2099 | case FTRACE_BUG_INIT: | |
2100 | pr_info("Initializing ftrace call sites\n"); | |
2101 | break; | |
2102 | case FTRACE_BUG_NOP: | |
2103 | pr_info("Setting ftrace call site to NOP\n"); | |
2104 | break; | |
2105 | case FTRACE_BUG_CALL: | |
2106 | pr_info("Setting ftrace call site to call ftrace function\n"); | |
2107 | break; | |
2108 | case FTRACE_BUG_UPDATE: | |
2109 | pr_info("Updating ftrace call site to call a different ftrace function\n"); | |
2110 | break; | |
2111 | } | |
2112 | } | |
2113 | ||
c88fd863 SR |
2114 | /** |
2115 | * ftrace_bug - report and shutdown function tracer | |
2116 | * @failed: The failed type (EFAULT, EINVAL, EPERM) | |
4fd3279b | 2117 | * @rec: The record that failed |
c88fd863 SR |
2118 | * |
2119 | * The arch code that enables or disables the function tracing | |
2120 | * can call ftrace_bug() when it has detected a problem in | |
2121 | * modifying the code. @failed should be one of either: | |
2122 | * EFAULT - if the problem happens on reading the @ip address | |
2123 | * EINVAL - if what is read at @ip is not what was expected | |
9efb85c5 | 2124 | * EPERM - if the problem happens on writing to the @ip address |
c88fd863 | 2125 | */ |
4fd3279b | 2126 | void ftrace_bug(int failed, struct dyn_ftrace *rec) |
b17e8a37 | 2127 | { |
4fd3279b SRRH |
2128 | unsigned long ip = rec ? rec->ip : 0; |
2129 | ||
c143b775 CJ |
2130 | pr_info("------------[ ftrace bug ]------------\n"); |
2131 | ||
b17e8a37 SR |
2132 | switch (failed) { |
2133 | case -EFAULT: | |
b17e8a37 | 2134 | pr_info("ftrace faulted on modifying "); |
2062a4e8 | 2135 | print_ip_sym(KERN_INFO, ip); |
b17e8a37 SR |
2136 | break; |
2137 | case -EINVAL: | |
b17e8a37 | 2138 | pr_info("ftrace failed to modify "); |
2062a4e8 | 2139 | print_ip_sym(KERN_INFO, ip); |
b05086c7 | 2140 | print_ip_ins(" actual: ", (unsigned char *)ip); |
4fd3279b | 2141 | pr_cont("\n"); |
b05086c7 SRRH |
2142 | if (ftrace_expected) { |
2143 | print_ip_ins(" expected: ", ftrace_expected); | |
2144 | pr_cont("\n"); | |
2145 | } | |
b17e8a37 SR |
2146 | break; |
2147 | case -EPERM: | |
b17e8a37 | 2148 | pr_info("ftrace faulted on writing "); |
2062a4e8 | 2149 | print_ip_sym(KERN_INFO, ip); |
b17e8a37 SR |
2150 | break; |
2151 | default: | |
b17e8a37 | 2152 | pr_info("ftrace faulted on unknown error "); |
2062a4e8 | 2153 | print_ip_sym(KERN_INFO, ip); |
b17e8a37 | 2154 | } |
02a392a0 | 2155 | print_bug_type(); |
4fd3279b SRRH |
2156 | if (rec) { |
2157 | struct ftrace_ops *ops = NULL; | |
2158 | ||
2159 | pr_info("ftrace record flags: %lx\n", rec->flags); | |
cbad0fb2 MR |
2160 | pr_cont(" (%ld)%s%s", ftrace_rec_count(rec), |
2161 | rec->flags & FTRACE_FL_REGS ? " R" : " ", | |
2162 | rec->flags & FTRACE_FL_CALL_OPS ? " O" : " "); | |
4fd3279b SRRH |
2163 | if (rec->flags & FTRACE_FL_TRAMP_EN) { |
2164 | ops = ftrace_find_tramp_ops_any(rec); | |
39daa7b9 SRRH |
2165 | if (ops) { |
2166 | do { | |
2167 | pr_cont("\ttramp: %pS (%pS)", | |
2168 | (void *)ops->trampoline, | |
2169 | (void *)ops->func); | |
2170 | ops = ftrace_find_tramp_ops_next(rec, ops); | |
2171 | } while (ops); | |
2172 | } else | |
4fd3279b SRRH |
2173 | pr_cont("\ttramp: ERROR!"); |
2174 | ||
2175 | } | |
2176 | ip = ftrace_get_addr_curr(rec); | |
39daa7b9 | 2177 | pr_cont("\n expected tramp: %lx\n", ip); |
4fd3279b | 2178 | } |
c143b775 CJ |
2179 | |
2180 | FTRACE_WARN_ON_ONCE(1); | |
b17e8a37 SR |
2181 | } |
2182 | ||
7375dca1 | 2183 | static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update) |
5072c59f | 2184 | { |
64fbcd16 | 2185 | unsigned long flag = 0UL; |
e7d3737e | 2186 | |
02a392a0 SRRH |
2187 | ftrace_bug_type = FTRACE_BUG_UNKNOWN; |
2188 | ||
cf04f2d5 | 2189 | if (skip_record(rec)) |
b7ffffbb SRRH |
2190 | return FTRACE_UPDATE_IGNORE; |
2191 | ||
982c350b | 2192 | /* |
30fb6aa7 | 2193 | * If we are updating calls: |
982c350b | 2194 | * |
ed926f9b SR |
2195 | * If the record has a ref count, then we need to enable it |
2196 | * because someone is using it. | |
982c350b | 2197 | * |
ed926f9b SR |
2198 | * Otherwise we make sure its disabled. |
2199 | * | |
30fb6aa7 | 2200 | * If we are disabling calls, then disable all records that |
ed926f9b | 2201 | * are enabled. |
982c350b | 2202 | */ |
0376bde1 | 2203 | if (enable && ftrace_rec_count(rec)) |
ed926f9b | 2204 | flag = FTRACE_FL_ENABLED; |
982c350b | 2205 | |
08f6fba5 | 2206 | /* |
79922b80 SRRH |
2207 | * If enabling and the REGS flag does not match the REGS_EN, or |
2208 | * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore | |
2209 | * this record. Set flags to fail the compare against ENABLED. | |
763e34e7 | 2210 | * Same for direct calls. |
08f6fba5 | 2211 | */ |
79922b80 | 2212 | if (flag) { |
763e34e7 | 2213 | if (!(rec->flags & FTRACE_FL_REGS) != |
79922b80 SRRH |
2214 | !(rec->flags & FTRACE_FL_REGS_EN)) |
2215 | flag |= FTRACE_FL_REGS; | |
2216 | ||
763e34e7 | 2217 | if (!(rec->flags & FTRACE_FL_TRAMP) != |
79922b80 SRRH |
2218 | !(rec->flags & FTRACE_FL_TRAMP_EN)) |
2219 | flag |= FTRACE_FL_TRAMP; | |
763e34e7 SRV |
2220 | |
2221 | /* | |
2222 | * Direct calls are special, as count matters. | |
2223 | * We must test the record for direct, if the | |
2224 | * DIRECT and DIRECT_EN do not match, but only | |
2225 | * if the count is 1. That's because, if the | |
2226 | * count is something other than one, we do not | |
2227 | * want the direct enabled (it will be done via the | |
2228 | * direct helper). But if DIRECT_EN is set, and | |
2229 | * the count is not one, we need to clear it. | |
cbad0fb2 | 2230 | * |
763e34e7 SRV |
2231 | */ |
2232 | if (ftrace_rec_count(rec) == 1) { | |
2233 | if (!(rec->flags & FTRACE_FL_DIRECT) != | |
2234 | !(rec->flags & FTRACE_FL_DIRECT_EN)) | |
2235 | flag |= FTRACE_FL_DIRECT; | |
2236 | } else if (rec->flags & FTRACE_FL_DIRECT_EN) { | |
2237 | flag |= FTRACE_FL_DIRECT; | |
2238 | } | |
cbad0fb2 MR |
2239 | |
2240 | /* | |
2241 | * Ops calls are special, as count matters. | |
2242 | * As with direct calls, they must only be enabled when count | |
2243 | * is one, otherwise they'll be handled via the list ops. | |
2244 | */ | |
2245 | if (ftrace_rec_count(rec) == 1) { | |
2246 | if (!(rec->flags & FTRACE_FL_CALL_OPS) != | |
2247 | !(rec->flags & FTRACE_FL_CALL_OPS_EN)) | |
2248 | flag |= FTRACE_FL_CALL_OPS; | |
2249 | } else if (rec->flags & FTRACE_FL_CALL_OPS_EN) { | |
2250 | flag |= FTRACE_FL_CALL_OPS; | |
2251 | } | |
79922b80 | 2252 | } |
08f6fba5 | 2253 | |
64fbcd16 XG |
2254 | /* If the state of this record hasn't changed, then do nothing */ |
2255 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
c88fd863 | 2256 | return FTRACE_UPDATE_IGNORE; |
982c350b | 2257 | |
64fbcd16 | 2258 | if (flag) { |
08f6fba5 SR |
2259 | /* Save off if rec is being enabled (for return value) */ |
2260 | flag ^= rec->flags & FTRACE_FL_ENABLED; | |
2261 | ||
2262 | if (update) { | |
e11b521a | 2263 | rec->flags |= FTRACE_FL_ENABLED | FTRACE_FL_TOUCHED; |
08f6fba5 SR |
2264 | if (flag & FTRACE_FL_REGS) { |
2265 | if (rec->flags & FTRACE_FL_REGS) | |
2266 | rec->flags |= FTRACE_FL_REGS_EN; | |
2267 | else | |
2268 | rec->flags &= ~FTRACE_FL_REGS_EN; | |
2269 | } | |
79922b80 SRRH |
2270 | if (flag & FTRACE_FL_TRAMP) { |
2271 | if (rec->flags & FTRACE_FL_TRAMP) | |
2272 | rec->flags |= FTRACE_FL_TRAMP_EN; | |
2273 | else | |
2274 | rec->flags &= ~FTRACE_FL_TRAMP_EN; | |
2275 | } | |
d19ad077 | 2276 | |
6ce2c04f SRG |
2277 | /* Keep track of anything that modifies the function */ |
2278 | if (rec->flags & (FTRACE_FL_DIRECT | FTRACE_FL_IPMODIFY)) | |
2279 | rec->flags |= FTRACE_FL_MODIFIED; | |
2280 | ||
763e34e7 SRV |
2281 | if (flag & FTRACE_FL_DIRECT) { |
2282 | /* | |
2283 | * If there's only one user (direct_ops helper) | |
2284 | * then we can call the direct function | |
2285 | * directly (no ftrace trampoline). | |
2286 | */ | |
2287 | if (ftrace_rec_count(rec) == 1) { | |
2288 | if (rec->flags & FTRACE_FL_DIRECT) | |
2289 | rec->flags |= FTRACE_FL_DIRECT_EN; | |
2290 | else | |
2291 | rec->flags &= ~FTRACE_FL_DIRECT_EN; | |
2292 | } else { | |
2293 | /* | |
2294 | * Can only call directly if there's | |
2295 | * only one callback to the function. | |
2296 | */ | |
2297 | rec->flags &= ~FTRACE_FL_DIRECT_EN; | |
2298 | } | |
2299 | } | |
cbad0fb2 MR |
2300 | |
2301 | if (flag & FTRACE_FL_CALL_OPS) { | |
2302 | if (ftrace_rec_count(rec) == 1) { | |
2303 | if (rec->flags & FTRACE_FL_CALL_OPS) | |
2304 | rec->flags |= FTRACE_FL_CALL_OPS_EN; | |
2305 | else | |
2306 | rec->flags &= ~FTRACE_FL_CALL_OPS_EN; | |
2307 | } else { | |
2308 | /* | |
2309 | * Can only call directly if there's | |
2310 | * only one set of associated ops. | |
2311 | */ | |
2312 | rec->flags &= ~FTRACE_FL_CALL_OPS_EN; | |
2313 | } | |
2314 | } | |
08f6fba5 SR |
2315 | } |
2316 | ||
2317 | /* | |
2318 | * If this record is being updated from a nop, then | |
2319 | * return UPDATE_MAKE_CALL. | |
08f6fba5 SR |
2320 | * Otherwise, |
2321 | * return UPDATE_MODIFY_CALL to tell the caller to convert | |
f1b2f2bd | 2322 | * from the save regs, to a non-save regs function or |
79922b80 | 2323 | * vice versa, or from a trampoline call. |
08f6fba5 | 2324 | */ |
02a392a0 SRRH |
2325 | if (flag & FTRACE_FL_ENABLED) { |
2326 | ftrace_bug_type = FTRACE_BUG_CALL; | |
08f6fba5 | 2327 | return FTRACE_UPDATE_MAKE_CALL; |
02a392a0 | 2328 | } |
f1b2f2bd | 2329 | |
02a392a0 | 2330 | ftrace_bug_type = FTRACE_BUG_UPDATE; |
f1b2f2bd | 2331 | return FTRACE_UPDATE_MODIFY_CALL; |
c88fd863 SR |
2332 | } |
2333 | ||
08f6fba5 SR |
2334 | if (update) { |
2335 | /* If there's no more users, clear all flags */ | |
0376bde1 | 2336 | if (!ftrace_rec_count(rec)) |
e11b521a | 2337 | rec->flags &= FTRACE_NOCLEAR_FLAGS; |
08f6fba5 | 2338 | else |
b24d443b SRRH |
2339 | /* |
2340 | * Just disable the record, but keep the ops TRAMP | |
2341 | * and REGS states. The _EN flags must be disabled though. | |
2342 | */ | |
2343 | rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN | | |
cbad0fb2 MR |
2344 | FTRACE_FL_REGS_EN | FTRACE_FL_DIRECT_EN | |
2345 | FTRACE_FL_CALL_OPS_EN); | |
08f6fba5 | 2346 | } |
c88fd863 | 2347 | |
02a392a0 | 2348 | ftrace_bug_type = FTRACE_BUG_NOP; |
c88fd863 SR |
2349 | return FTRACE_UPDATE_MAKE_NOP; |
2350 | } | |
2351 | ||
2352 | /** | |
6130722f | 2353 | * ftrace_update_record - set a record that now is tracing or not |
c88fd863 | 2354 | * @rec: the record to update |
7375dca1 | 2355 | * @enable: set to true if the record is tracing, false to force disable |
c88fd863 SR |
2356 | * |
2357 | * The records that represent all functions that can be traced need | |
2358 | * to be updated when tracing has been enabled. | |
2359 | */ | |
7375dca1 | 2360 | int ftrace_update_record(struct dyn_ftrace *rec, bool enable) |
c88fd863 | 2361 | { |
7375dca1 | 2362 | return ftrace_check_record(rec, enable, true); |
c88fd863 SR |
2363 | } |
2364 | ||
2365 | /** | |
6130722f | 2366 | * ftrace_test_record - check if the record has been enabled or not |
c88fd863 | 2367 | * @rec: the record to test |
7375dca1 | 2368 | * @enable: set to true to check if enabled, false if it is disabled |
c88fd863 SR |
2369 | * |
2370 | * The arch code may need to test if a record is already set to | |
2371 | * tracing to determine how to modify the function code that it | |
2372 | * represents. | |
2373 | */ | |
7375dca1 | 2374 | int ftrace_test_record(struct dyn_ftrace *rec, bool enable) |
c88fd863 | 2375 | { |
7375dca1 | 2376 | return ftrace_check_record(rec, enable, false); |
c88fd863 SR |
2377 | } |
2378 | ||
5fecaa04 SRRH |
2379 | static struct ftrace_ops * |
2380 | ftrace_find_tramp_ops_any(struct dyn_ftrace *rec) | |
2381 | { | |
2382 | struct ftrace_ops *op; | |
fef5aeee | 2383 | unsigned long ip = rec->ip; |
5fecaa04 SRRH |
2384 | |
2385 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2386 | ||
2387 | if (!op->trampoline) | |
2388 | continue; | |
2389 | ||
fef5aeee | 2390 | if (hash_contains_ip(ip, op->func_hash)) |
5fecaa04 SRRH |
2391 | return op; |
2392 | } while_for_each_ftrace_op(op); | |
2393 | ||
2394 | return NULL; | |
2395 | } | |
2396 | ||
4c75b0ff NR |
2397 | static struct ftrace_ops * |
2398 | ftrace_find_tramp_ops_any_other(struct dyn_ftrace *rec, struct ftrace_ops *op_exclude) | |
2399 | { | |
2400 | struct ftrace_ops *op; | |
2401 | unsigned long ip = rec->ip; | |
2402 | ||
2403 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2404 | ||
2405 | if (op == op_exclude || !op->trampoline) | |
2406 | continue; | |
2407 | ||
2408 | if (hash_contains_ip(ip, op->func_hash)) | |
2409 | return op; | |
2410 | } while_for_each_ftrace_op(op); | |
2411 | ||
2412 | return NULL; | |
2413 | } | |
2414 | ||
39daa7b9 SRRH |
2415 | static struct ftrace_ops * |
2416 | ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, | |
2417 | struct ftrace_ops *op) | |
2418 | { | |
2419 | unsigned long ip = rec->ip; | |
2420 | ||
2421 | while_for_each_ftrace_op(op) { | |
2422 | ||
2423 | if (!op->trampoline) | |
2424 | continue; | |
2425 | ||
2426 | if (hash_contains_ip(ip, op->func_hash)) | |
2427 | return op; | |
026bb845 | 2428 | } |
39daa7b9 SRRH |
2429 | |
2430 | return NULL; | |
2431 | } | |
2432 | ||
79922b80 SRRH |
2433 | static struct ftrace_ops * |
2434 | ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec) | |
2435 | { | |
2436 | struct ftrace_ops *op; | |
fef5aeee | 2437 | unsigned long ip = rec->ip; |
79922b80 | 2438 | |
fef5aeee SRRH |
2439 | /* |
2440 | * Need to check removed ops first. | |
2441 | * If they are being removed, and this rec has a tramp, | |
2442 | * and this rec is in the ops list, then it would be the | |
2443 | * one with the tramp. | |
2444 | */ | |
2445 | if (removed_ops) { | |
2446 | if (hash_contains_ip(ip, &removed_ops->old_hash)) | |
79922b80 SRRH |
2447 | return removed_ops; |
2448 | } | |
2449 | ||
fef5aeee SRRH |
2450 | /* |
2451 | * Need to find the current trampoline for a rec. | |
2452 | * Now, a trampoline is only attached to a rec if there | |
2453 | * was a single 'ops' attached to it. But this can be called | |
2454 | * when we are adding another op to the rec or removing the | |
2455 | * current one. Thus, if the op is being added, we can | |
2456 | * ignore it because it hasn't attached itself to the rec | |
4fc40904 SRRH |
2457 | * yet. |
2458 | * | |
2459 | * If an ops is being modified (hooking to different functions) | |
2460 | * then we don't care about the new functions that are being | |
2461 | * added, just the old ones (that are probably being removed). | |
2462 | * | |
2463 | * If we are adding an ops to a function that already is using | |
2464 | * a trampoline, it needs to be removed (trampolines are only | |
2465 | * for single ops connected), then an ops that is not being | |
2466 | * modified also needs to be checked. | |
fef5aeee | 2467 | */ |
79922b80 | 2468 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
fef5aeee SRRH |
2469 | |
2470 | if (!op->trampoline) | |
2471 | continue; | |
2472 | ||
2473 | /* | |
2474 | * If the ops is being added, it hasn't gotten to | |
2475 | * the point to be removed from this tree yet. | |
2476 | */ | |
2477 | if (op->flags & FTRACE_OPS_FL_ADDING) | |
79922b80 SRRH |
2478 | continue; |
2479 | ||
4fc40904 | 2480 | |
fef5aeee | 2481 | /* |
4fc40904 SRRH |
2482 | * If the ops is being modified and is in the old |
2483 | * hash, then it is probably being removed from this | |
2484 | * function. | |
fef5aeee | 2485 | */ |
fef5aeee SRRH |
2486 | if ((op->flags & FTRACE_OPS_FL_MODIFYING) && |
2487 | hash_contains_ip(ip, &op->old_hash)) | |
79922b80 | 2488 | return op; |
4fc40904 SRRH |
2489 | /* |
2490 | * If the ops is not being added or modified, and it's | |
2491 | * in its normal filter hash, then this must be the one | |
2492 | * we want! | |
2493 | */ | |
2494 | if (!(op->flags & FTRACE_OPS_FL_MODIFYING) && | |
2495 | hash_contains_ip(ip, op->func_hash)) | |
2496 | return op; | |
79922b80 SRRH |
2497 | |
2498 | } while_for_each_ftrace_op(op); | |
2499 | ||
2500 | return NULL; | |
2501 | } | |
2502 | ||
2503 | static struct ftrace_ops * | |
2504 | ftrace_find_tramp_ops_new(struct dyn_ftrace *rec) | |
2505 | { | |
2506 | struct ftrace_ops *op; | |
fef5aeee | 2507 | unsigned long ip = rec->ip; |
79922b80 SRRH |
2508 | |
2509 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2510 | /* pass rec in as regs to have non-NULL val */ | |
fef5aeee | 2511 | if (hash_contains_ip(ip, op->func_hash)) |
79922b80 SRRH |
2512 | return op; |
2513 | } while_for_each_ftrace_op(op); | |
2514 | ||
2515 | return NULL; | |
2516 | } | |
2517 | ||
cbad0fb2 MR |
2518 | struct ftrace_ops * |
2519 | ftrace_find_unique_ops(struct dyn_ftrace *rec) | |
2520 | { | |
2521 | struct ftrace_ops *op, *found = NULL; | |
2522 | unsigned long ip = rec->ip; | |
2523 | ||
2524 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2525 | ||
2526 | if (hash_contains_ip(ip, op->func_hash)) { | |
2527 | if (found) | |
2528 | return NULL; | |
2529 | found = op; | |
2530 | } | |
2531 | ||
2532 | } while_for_each_ftrace_op(op); | |
2533 | ||
2534 | return found; | |
2535 | } | |
2536 | ||
763e34e7 SRV |
2537 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS |
2538 | /* Protected by rcu_tasks for reading, and direct_mutex for writing */ | |
2539 | static struct ftrace_hash *direct_functions = EMPTY_HASH; | |
2540 | static DEFINE_MUTEX(direct_mutex); | |
a3ad1a7e | 2541 | int ftrace_direct_func_count; |
763e34e7 SRV |
2542 | |
2543 | /* | |
2544 | * Search the direct_functions hash to see if the given instruction pointer | |
2545 | * has a direct caller attached to it. | |
2546 | */ | |
ff205766 | 2547 | unsigned long ftrace_find_rec_direct(unsigned long ip) |
763e34e7 SRV |
2548 | { |
2549 | struct ftrace_func_entry *entry; | |
2550 | ||
2551 | entry = __ftrace_lookup_ip(direct_functions, ip); | |
2552 | if (!entry) | |
2553 | return 0; | |
2554 | ||
2555 | return entry->direct; | |
2556 | } | |
2557 | ||
1904a814 JO |
2558 | static struct ftrace_func_entry* |
2559 | ftrace_add_rec_direct(unsigned long ip, unsigned long addr, | |
2560 | struct ftrace_hash **free_hash) | |
2561 | { | |
2562 | struct ftrace_func_entry *entry; | |
2563 | ||
2564 | if (ftrace_hash_empty(direct_functions) || | |
2565 | direct_functions->count > 2 * (1 << direct_functions->size_bits)) { | |
2566 | struct ftrace_hash *new_hash; | |
2567 | int size = ftrace_hash_empty(direct_functions) ? 0 : | |
2568 | direct_functions->count + 1; | |
2569 | ||
2570 | if (size < 32) | |
2571 | size = 32; | |
2572 | ||
2573 | new_hash = dup_hash(direct_functions, size); | |
2574 | if (!new_hash) | |
2575 | return NULL; | |
2576 | ||
2577 | *free_hash = direct_functions; | |
2578 | direct_functions = new_hash; | |
2579 | } | |
2580 | ||
2581 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
2582 | if (!entry) | |
2583 | return NULL; | |
2584 | ||
2585 | entry->ip = ip; | |
2586 | entry->direct = addr; | |
2587 | __add_hash_entry(direct_functions, entry); | |
2588 | return entry; | |
2589 | } | |
2590 | ||
763e34e7 | 2591 | static void call_direct_funcs(unsigned long ip, unsigned long pip, |
d19ad077 | 2592 | struct ftrace_ops *ops, struct ftrace_regs *fregs) |
763e34e7 | 2593 | { |
dbaccb61 | 2594 | unsigned long addr = READ_ONCE(ops->direct_call); |
763e34e7 | 2595 | |
763e34e7 SRV |
2596 | if (!addr) |
2597 | return; | |
2598 | ||
9705bc70 | 2599 | arch_ftrace_set_direct_caller(fregs, addr); |
763e34e7 | 2600 | } |
763e34e7 SRV |
2601 | #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ |
2602 | ||
7413af1f SRRH |
2603 | /** |
2604 | * ftrace_get_addr_new - Get the call address to set to | |
2605 | * @rec: The ftrace record descriptor | |
2606 | * | |
2607 | * If the record has the FTRACE_FL_REGS set, that means that it | |
2608 | * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS | |
5c8c206e | 2609 | * is not set, then it wants to convert to the normal callback. |
7413af1f SRRH |
2610 | * |
2611 | * Returns the address of the trampoline to set to | |
2612 | */ | |
2613 | unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec) | |
2614 | { | |
79922b80 | 2615 | struct ftrace_ops *ops; |
763e34e7 SRV |
2616 | unsigned long addr; |
2617 | ||
2618 | if ((rec->flags & FTRACE_FL_DIRECT) && | |
2619 | (ftrace_rec_count(rec) == 1)) { | |
ff205766 | 2620 | addr = ftrace_find_rec_direct(rec->ip); |
763e34e7 SRV |
2621 | if (addr) |
2622 | return addr; | |
2623 | WARN_ON_ONCE(1); | |
2624 | } | |
79922b80 SRRH |
2625 | |
2626 | /* Trampolines take precedence over regs */ | |
2627 | if (rec->flags & FTRACE_FL_TRAMP) { | |
2628 | ops = ftrace_find_tramp_ops_new(rec); | |
2629 | if (FTRACE_WARN_ON(!ops || !ops->trampoline)) { | |
bce0b6c5 SRRH |
2630 | pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n", |
2631 | (void *)rec->ip, (void *)rec->ip, rec->flags); | |
79922b80 SRRH |
2632 | /* Ftrace is shutting down, return anything */ |
2633 | return (unsigned long)FTRACE_ADDR; | |
2634 | } | |
2635 | return ops->trampoline; | |
2636 | } | |
2637 | ||
7413af1f SRRH |
2638 | if (rec->flags & FTRACE_FL_REGS) |
2639 | return (unsigned long)FTRACE_REGS_ADDR; | |
2640 | else | |
2641 | return (unsigned long)FTRACE_ADDR; | |
2642 | } | |
2643 | ||
2644 | /** | |
2645 | * ftrace_get_addr_curr - Get the call address that is already there | |
2646 | * @rec: The ftrace record descriptor | |
2647 | * | |
2648 | * The FTRACE_FL_REGS_EN is set when the record already points to | |
2649 | * a function that saves all the regs. Basically the '_EN' version | |
2650 | * represents the current state of the function. | |
2651 | * | |
2652 | * Returns the address of the trampoline that is currently being called | |
2653 | */ | |
2654 | unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec) | |
2655 | { | |
79922b80 | 2656 | struct ftrace_ops *ops; |
763e34e7 SRV |
2657 | unsigned long addr; |
2658 | ||
2659 | /* Direct calls take precedence over trampolines */ | |
2660 | if (rec->flags & FTRACE_FL_DIRECT_EN) { | |
ff205766 | 2661 | addr = ftrace_find_rec_direct(rec->ip); |
763e34e7 SRV |
2662 | if (addr) |
2663 | return addr; | |
2664 | WARN_ON_ONCE(1); | |
2665 | } | |
79922b80 SRRH |
2666 | |
2667 | /* Trampolines take precedence over regs */ | |
2668 | if (rec->flags & FTRACE_FL_TRAMP_EN) { | |
2669 | ops = ftrace_find_tramp_ops_curr(rec); | |
2670 | if (FTRACE_WARN_ON(!ops)) { | |
a395d6a7 JP |
2671 | pr_warn("Bad trampoline accounting at: %p (%pS)\n", |
2672 | (void *)rec->ip, (void *)rec->ip); | |
79922b80 SRRH |
2673 | /* Ftrace is shutting down, return anything */ |
2674 | return (unsigned long)FTRACE_ADDR; | |
2675 | } | |
2676 | return ops->trampoline; | |
2677 | } | |
2678 | ||
7413af1f SRRH |
2679 | if (rec->flags & FTRACE_FL_REGS_EN) |
2680 | return (unsigned long)FTRACE_REGS_ADDR; | |
2681 | else | |
2682 | return (unsigned long)FTRACE_ADDR; | |
2683 | } | |
2684 | ||
c88fd863 | 2685 | static int |
7375dca1 | 2686 | __ftrace_replace_code(struct dyn_ftrace *rec, bool enable) |
c88fd863 | 2687 | { |
08f6fba5 | 2688 | unsigned long ftrace_old_addr; |
c88fd863 SR |
2689 | unsigned long ftrace_addr; |
2690 | int ret; | |
2691 | ||
7c0868e0 | 2692 | ftrace_addr = ftrace_get_addr_new(rec); |
c88fd863 | 2693 | |
7c0868e0 SRRH |
2694 | /* This needs to be done before we call ftrace_update_record */ |
2695 | ftrace_old_addr = ftrace_get_addr_curr(rec); | |
2696 | ||
2697 | ret = ftrace_update_record(rec, enable); | |
08f6fba5 | 2698 | |
02a392a0 SRRH |
2699 | ftrace_bug_type = FTRACE_BUG_UNKNOWN; |
2700 | ||
c88fd863 SR |
2701 | switch (ret) { |
2702 | case FTRACE_UPDATE_IGNORE: | |
2703 | return 0; | |
2704 | ||
2705 | case FTRACE_UPDATE_MAKE_CALL: | |
02a392a0 | 2706 | ftrace_bug_type = FTRACE_BUG_CALL; |
64fbcd16 | 2707 | return ftrace_make_call(rec, ftrace_addr); |
c88fd863 SR |
2708 | |
2709 | case FTRACE_UPDATE_MAKE_NOP: | |
02a392a0 | 2710 | ftrace_bug_type = FTRACE_BUG_NOP; |
39b5552c | 2711 | return ftrace_make_nop(NULL, rec, ftrace_old_addr); |
08f6fba5 | 2712 | |
08f6fba5 | 2713 | case FTRACE_UPDATE_MODIFY_CALL: |
02a392a0 | 2714 | ftrace_bug_type = FTRACE_BUG_UPDATE; |
08f6fba5 | 2715 | return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr); |
5072c59f SR |
2716 | } |
2717 | ||
9efb85c5 | 2718 | return -1; /* unknown ftrace bug */ |
5072c59f SR |
2719 | } |
2720 | ||
a0572f68 | 2721 | void __weak ftrace_replace_code(int mod_flags) |
3c1720f0 | 2722 | { |
3c1720f0 SR |
2723 | struct dyn_ftrace *rec; |
2724 | struct ftrace_page *pg; | |
7375dca1 | 2725 | bool enable = mod_flags & FTRACE_MODIFY_ENABLE_FL; |
a0572f68 | 2726 | int schedulable = mod_flags & FTRACE_MODIFY_MAY_SLEEP_FL; |
6a24a244 | 2727 | int failed; |
3c1720f0 | 2728 | |
45a4a237 SR |
2729 | if (unlikely(ftrace_disabled)) |
2730 | return; | |
2731 | ||
265c831c | 2732 | do_for_each_ftrace_rec(pg, rec) { |
546fece4 | 2733 | |
cf04f2d5 | 2734 | if (skip_record(rec)) |
546fece4 SRRH |
2735 | continue; |
2736 | ||
e4f5d544 | 2737 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 2738 | if (failed) { |
4fd3279b | 2739 | ftrace_bug(failed, rec); |
3279ba37 SR |
2740 | /* Stop processing */ |
2741 | return; | |
3c1720f0 | 2742 | } |
a0572f68 SRV |
2743 | if (schedulable) |
2744 | cond_resched(); | |
265c831c | 2745 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
2746 | } |
2747 | ||
c88fd863 SR |
2748 | struct ftrace_rec_iter { |
2749 | struct ftrace_page *pg; | |
2750 | int index; | |
2751 | }; | |
2752 | ||
2753 | /** | |
6130722f | 2754 | * ftrace_rec_iter_start - start up iterating over traced functions |
c88fd863 SR |
2755 | * |
2756 | * Returns an iterator handle that is used to iterate over all | |
2757 | * the records that represent address locations where functions | |
2758 | * are traced. | |
2759 | * | |
2760 | * May return NULL if no records are available. | |
2761 | */ | |
2762 | struct ftrace_rec_iter *ftrace_rec_iter_start(void) | |
2763 | { | |
2764 | /* | |
2765 | * We only use a single iterator. | |
2766 | * Protected by the ftrace_lock mutex. | |
2767 | */ | |
2768 | static struct ftrace_rec_iter ftrace_rec_iter; | |
2769 | struct ftrace_rec_iter *iter = &ftrace_rec_iter; | |
2770 | ||
2771 | iter->pg = ftrace_pages_start; | |
2772 | iter->index = 0; | |
2773 | ||
2774 | /* Could have empty pages */ | |
2775 | while (iter->pg && !iter->pg->index) | |
2776 | iter->pg = iter->pg->next; | |
2777 | ||
2778 | if (!iter->pg) | |
2779 | return NULL; | |
2780 | ||
2781 | return iter; | |
2782 | } | |
2783 | ||
2784 | /** | |
6130722f | 2785 | * ftrace_rec_iter_next - get the next record to process. |
c88fd863 SR |
2786 | * @iter: The handle to the iterator. |
2787 | * | |
2788 | * Returns the next iterator after the given iterator @iter. | |
2789 | */ | |
2790 | struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) | |
2791 | { | |
2792 | iter->index++; | |
2793 | ||
2794 | if (iter->index >= iter->pg->index) { | |
2795 | iter->pg = iter->pg->next; | |
2796 | iter->index = 0; | |
2797 | ||
2798 | /* Could have empty pages */ | |
2799 | while (iter->pg && !iter->pg->index) | |
2800 | iter->pg = iter->pg->next; | |
2801 | } | |
2802 | ||
2803 | if (!iter->pg) | |
2804 | return NULL; | |
2805 | ||
2806 | return iter; | |
2807 | } | |
2808 | ||
2809 | /** | |
6130722f | 2810 | * ftrace_rec_iter_record - get the record at the iterator location |
c88fd863 SR |
2811 | * @iter: The current iterator location |
2812 | * | |
2813 | * Returns the record that the current @iter is at. | |
2814 | */ | |
2815 | struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) | |
2816 | { | |
2817 | return &iter->pg->records[iter->index]; | |
2818 | } | |
2819 | ||
492a7ea5 | 2820 | static int |
fbf6c73c | 2821 | ftrace_nop_initialize(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 | 2822 | { |
593eb8a2 | 2823 | int ret; |
3c1720f0 | 2824 | |
45a4a237 SR |
2825 | if (unlikely(ftrace_disabled)) |
2826 | return 0; | |
2827 | ||
fbf6c73c | 2828 | ret = ftrace_init_nop(mod, rec); |
593eb8a2 | 2829 | if (ret) { |
02a392a0 | 2830 | ftrace_bug_type = FTRACE_BUG_INIT; |
4fd3279b | 2831 | ftrace_bug(ret, rec); |
492a7ea5 | 2832 | return 0; |
37ad5084 | 2833 | } |
492a7ea5 | 2834 | return 1; |
3c1720f0 SR |
2835 | } |
2836 | ||
000ab691 SR |
2837 | /* |
2838 | * archs can override this function if they must do something | |
2839 | * before the modifying code is performed. | |
2840 | */ | |
3a2bfec0 | 2841 | void __weak ftrace_arch_code_modify_prepare(void) |
000ab691 | 2842 | { |
000ab691 SR |
2843 | } |
2844 | ||
2845 | /* | |
2846 | * archs can override this function if they must do something | |
2847 | * after the modifying code is performed. | |
2848 | */ | |
3a2bfec0 | 2849 | void __weak ftrace_arch_code_modify_post_process(void) |
000ab691 | 2850 | { |
000ab691 SR |
2851 | } |
2852 | ||
bd604f3d SRG |
2853 | static int update_ftrace_func(ftrace_func_t func) |
2854 | { | |
2855 | static ftrace_func_t save_func; | |
2856 | ||
2857 | /* Avoid updating if it hasn't changed */ | |
2858 | if (func == save_func) | |
2859 | return 0; | |
2860 | ||
2861 | save_func = func; | |
2862 | ||
2863 | return ftrace_update_ftrace_func(func); | |
2864 | } | |
2865 | ||
8ed3e2cf | 2866 | void ftrace_modify_all_code(int command) |
3d083395 | 2867 | { |
59338f75 | 2868 | int update = command & FTRACE_UPDATE_TRACE_FUNC; |
a0572f68 | 2869 | int mod_flags = 0; |
cd21067f | 2870 | int err = 0; |
59338f75 | 2871 | |
a0572f68 SRV |
2872 | if (command & FTRACE_MAY_SLEEP) |
2873 | mod_flags = FTRACE_MODIFY_MAY_SLEEP_FL; | |
2874 | ||
59338f75 SRRH |
2875 | /* |
2876 | * If the ftrace_caller calls a ftrace_ops func directly, | |
2877 | * we need to make sure that it only traces functions it | |
2878 | * expects to trace. When doing the switch of functions, | |
2879 | * we need to update to the ftrace_ops_list_func first | |
2880 | * before the transition between old and new calls are set, | |
2881 | * as the ftrace_ops_list_func will check the ops hashes | |
2882 | * to make sure the ops are having the right functions | |
2883 | * traced. | |
2884 | */ | |
cd21067f | 2885 | if (update) { |
bd604f3d | 2886 | err = update_ftrace_func(ftrace_ops_list_func); |
cd21067f PM |
2887 | if (FTRACE_WARN_ON(err)) |
2888 | return; | |
2889 | } | |
59338f75 | 2890 | |
8ed3e2cf | 2891 | if (command & FTRACE_UPDATE_CALLS) |
a0572f68 | 2892 | ftrace_replace_code(mod_flags | FTRACE_MODIFY_ENABLE_FL); |
8ed3e2cf | 2893 | else if (command & FTRACE_DISABLE_CALLS) |
a0572f68 | 2894 | ftrace_replace_code(mod_flags); |
d61f82d0 | 2895 | |
405e1d83 SRRH |
2896 | if (update && ftrace_trace_function != ftrace_ops_list_func) { |
2897 | function_trace_op = set_function_trace_op; | |
2898 | smp_wmb(); | |
2899 | /* If irqs are disabled, we are in stop machine */ | |
2900 | if (!irqs_disabled()) | |
2901 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
bd604f3d | 2902 | err = update_ftrace_func(ftrace_trace_function); |
cd21067f PM |
2903 | if (FTRACE_WARN_ON(err)) |
2904 | return; | |
405e1d83 | 2905 | } |
d61f82d0 | 2906 | |
8ed3e2cf | 2907 | if (command & FTRACE_START_FUNC_RET) |
cd21067f | 2908 | err = ftrace_enable_ftrace_graph_caller(); |
8ed3e2cf | 2909 | else if (command & FTRACE_STOP_FUNC_RET) |
cd21067f PM |
2910 | err = ftrace_disable_ftrace_graph_caller(); |
2911 | FTRACE_WARN_ON(err); | |
8ed3e2cf SR |
2912 | } |
2913 | ||
2914 | static int __ftrace_modify_code(void *data) | |
2915 | { | |
2916 | int *command = data; | |
2917 | ||
2918 | ftrace_modify_all_code(*command); | |
5a45cfe1 | 2919 | |
d61f82d0 | 2920 | return 0; |
3d083395 SR |
2921 | } |
2922 | ||
c88fd863 | 2923 | /** |
6130722f | 2924 | * ftrace_run_stop_machine - go back to the stop machine method |
c88fd863 SR |
2925 | * @command: The command to tell ftrace what to do |
2926 | * | |
2927 | * If an arch needs to fall back to the stop machine method, the | |
2928 | * it can call this function. | |
2929 | */ | |
2930 | void ftrace_run_stop_machine(int command) | |
2931 | { | |
2932 | stop_machine(__ftrace_modify_code, &command, NULL); | |
2933 | } | |
2934 | ||
2935 | /** | |
6130722f | 2936 | * arch_ftrace_update_code - modify the code to trace or not trace |
c88fd863 SR |
2937 | * @command: The command that needs to be done |
2938 | * | |
2939 | * Archs can override this function if it does not need to | |
2940 | * run stop_machine() to modify code. | |
2941 | */ | |
2942 | void __weak arch_ftrace_update_code(int command) | |
2943 | { | |
2944 | ftrace_run_stop_machine(command); | |
2945 | } | |
2946 | ||
e309b41d | 2947 | static void ftrace_run_update_code(int command) |
3d083395 | 2948 | { |
3a2bfec0 | 2949 | ftrace_arch_code_modify_prepare(); |
000ab691 | 2950 | |
c88fd863 SR |
2951 | /* |
2952 | * By default we use stop_machine() to modify the code. | |
2953 | * But archs can do what ever they want as long as it | |
2954 | * is safe. The stop_machine() is the safest, but also | |
2955 | * produces the most overhead. | |
2956 | */ | |
2957 | arch_ftrace_update_code(command); | |
2958 | ||
3a2bfec0 | 2959 | ftrace_arch_code_modify_post_process(); |
3d083395 SR |
2960 | } |
2961 | ||
8252ecf3 | 2962 | static void ftrace_run_modify_code(struct ftrace_ops *ops, int command, |
7485058e | 2963 | struct ftrace_ops_hash *old_hash) |
e1effa01 SRRH |
2964 | { |
2965 | ops->flags |= FTRACE_OPS_FL_MODIFYING; | |
7485058e SRRH |
2966 | ops->old_hash.filter_hash = old_hash->filter_hash; |
2967 | ops->old_hash.notrace_hash = old_hash->notrace_hash; | |
e1effa01 | 2968 | ftrace_run_update_code(command); |
8252ecf3 | 2969 | ops->old_hash.filter_hash = NULL; |
7485058e | 2970 | ops->old_hash.notrace_hash = NULL; |
e1effa01 SRRH |
2971 | ops->flags &= ~FTRACE_OPS_FL_MODIFYING; |
2972 | } | |
2973 | ||
d61f82d0 | 2974 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 2975 | static int ftrace_start_up; |
df4fc315 | 2976 | |
12cce594 SRRH |
2977 | void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops) |
2978 | { | |
2979 | } | |
2980 | ||
fc0ea795 AH |
2981 | /* List of trace_ops that have allocated trampolines */ |
2982 | static LIST_HEAD(ftrace_ops_trampoline_list); | |
2983 | ||
2984 | static void ftrace_add_trampoline_to_kallsyms(struct ftrace_ops *ops) | |
2985 | { | |
2986 | lockdep_assert_held(&ftrace_lock); | |
2987 | list_add_rcu(&ops->list, &ftrace_ops_trampoline_list); | |
2988 | } | |
2989 | ||
2990 | static void ftrace_remove_trampoline_from_kallsyms(struct ftrace_ops *ops) | |
2991 | { | |
2992 | lockdep_assert_held(&ftrace_lock); | |
2993 | list_del_rcu(&ops->list); | |
478ece95 | 2994 | synchronize_rcu(); |
fc0ea795 AH |
2995 | } |
2996 | ||
2997 | /* | |
2998 | * "__builtin__ftrace" is used as a module name in /proc/kallsyms for symbols | |
2999 | * for pages allocated for ftrace purposes, even though "__builtin__ftrace" is | |
3000 | * not a module. | |
3001 | */ | |
3002 | #define FTRACE_TRAMPOLINE_MOD "__builtin__ftrace" | |
3003 | #define FTRACE_TRAMPOLINE_SYM "ftrace_trampoline" | |
3004 | ||
3005 | static void ftrace_trampoline_free(struct ftrace_ops *ops) | |
3006 | { | |
3007 | if (ops && (ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP) && | |
dd9ddf46 | 3008 | ops->trampoline) { |
548e1f6c AH |
3009 | /* |
3010 | * Record the text poke event before the ksymbol unregister | |
3011 | * event. | |
3012 | */ | |
3013 | perf_event_text_poke((void *)ops->trampoline, | |
3014 | (void *)ops->trampoline, | |
3015 | ops->trampoline_size, NULL, 0); | |
dd9ddf46 AH |
3016 | perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL, |
3017 | ops->trampoline, ops->trampoline_size, | |
3018 | true, FTRACE_TRAMPOLINE_SYM); | |
3019 | /* Remove from kallsyms after the perf events */ | |
fc0ea795 | 3020 | ftrace_remove_trampoline_from_kallsyms(ops); |
dd9ddf46 | 3021 | } |
fc0ea795 AH |
3022 | |
3023 | arch_ftrace_trampoline_free(ops); | |
3024 | } | |
3025 | ||
df4fc315 SR |
3026 | static void ftrace_startup_enable(int command) |
3027 | { | |
3028 | if (saved_ftrace_func != ftrace_trace_function) { | |
3029 | saved_ftrace_func = ftrace_trace_function; | |
3030 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
3031 | } | |
3032 | ||
3033 | if (!command || !ftrace_enabled) | |
3034 | return; | |
3035 | ||
3036 | ftrace_run_update_code(command); | |
3037 | } | |
d61f82d0 | 3038 | |
e1effa01 SRRH |
3039 | static void ftrace_startup_all(int command) |
3040 | { | |
3041 | update_all_ops = true; | |
3042 | ftrace_startup_enable(command); | |
3043 | update_all_ops = false; | |
3044 | } | |
3045 | ||
3306fc4a | 3046 | int ftrace_startup(struct ftrace_ops *ops, int command) |
3d083395 | 3047 | { |
8a56d776 | 3048 | int ret; |
b848914c | 3049 | |
4eebcc81 | 3050 | if (unlikely(ftrace_disabled)) |
a1cd6173 | 3051 | return -ENODEV; |
4eebcc81 | 3052 | |
8a56d776 SRRH |
3053 | ret = __register_ftrace_function(ops); |
3054 | if (ret) | |
3055 | return ret; | |
3056 | ||
60a7ecf4 | 3057 | ftrace_start_up++; |
d61f82d0 | 3058 | |
e1effa01 SRRH |
3059 | /* |
3060 | * Note that ftrace probes uses this to start up | |
3061 | * and modify functions it will probe. But we still | |
3062 | * set the ADDING flag for modification, as probes | |
3063 | * do not have trampolines. If they add them in the | |
3064 | * future, then the probes will need to distinguish | |
3065 | * between adding and updating probes. | |
3066 | */ | |
3067 | ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING; | |
66209a5b | 3068 | |
f8b8be8a MH |
3069 | ret = ftrace_hash_ipmodify_enable(ops); |
3070 | if (ret < 0) { | |
3071 | /* Rollback registration process */ | |
3072 | __unregister_ftrace_function(ops); | |
3073 | ftrace_start_up--; | |
3074 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; | |
d5e47505 MB |
3075 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC) |
3076 | ftrace_trampoline_free(ops); | |
f8b8be8a MH |
3077 | return ret; |
3078 | } | |
3079 | ||
7f50d06b JO |
3080 | if (ftrace_hash_rec_enable(ops, 1)) |
3081 | command |= FTRACE_UPDATE_CALLS; | |
ed926f9b | 3082 | |
df4fc315 | 3083 | ftrace_startup_enable(command); |
a1cd6173 | 3084 | |
c3b0f72e YJ |
3085 | /* |
3086 | * If ftrace is in an undefined state, we just remove ops from list | |
3087 | * to prevent the NULL pointer, instead of totally rolling it back and | |
3088 | * free trampoline, because those actions could cause further damage. | |
3089 | */ | |
3090 | if (unlikely(ftrace_disabled)) { | |
3091 | __unregister_ftrace_function(ops); | |
3092 | return -ENODEV; | |
3093 | } | |
3094 | ||
e1effa01 SRRH |
3095 | ops->flags &= ~FTRACE_OPS_FL_ADDING; |
3096 | ||
a1cd6173 | 3097 | return 0; |
3d083395 SR |
3098 | } |
3099 | ||
3306fc4a | 3100 | int ftrace_shutdown(struct ftrace_ops *ops, int command) |
3d083395 | 3101 | { |
8a56d776 | 3102 | int ret; |
b848914c | 3103 | |
4eebcc81 | 3104 | if (unlikely(ftrace_disabled)) |
8a56d776 SRRH |
3105 | return -ENODEV; |
3106 | ||
3107 | ret = __unregister_ftrace_function(ops); | |
3108 | if (ret) | |
3109 | return ret; | |
4eebcc81 | 3110 | |
60a7ecf4 | 3111 | ftrace_start_up--; |
9ea1a153 FW |
3112 | /* |
3113 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
3114 | * critical but the ftrace_call callers may be never nopped again after | |
3115 | * further ftrace uses. | |
3116 | */ | |
3117 | WARN_ON_ONCE(ftrace_start_up < 0); | |
3118 | ||
f8b8be8a MH |
3119 | /* Disabling ipmodify never fails */ |
3120 | ftrace_hash_ipmodify_disable(ops); | |
ed926f9b | 3121 | |
7f50d06b JO |
3122 | if (ftrace_hash_rec_disable(ops, 1)) |
3123 | command |= FTRACE_UPDATE_CALLS; | |
b848914c | 3124 | |
7f50d06b | 3125 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
3d083395 | 3126 | |
d61f82d0 SR |
3127 | if (saved_ftrace_func != ftrace_trace_function) { |
3128 | saved_ftrace_func = ftrace_trace_function; | |
3129 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
3130 | } | |
3d083395 | 3131 | |
0e792b89 LH |
3132 | if (!command || !ftrace_enabled) |
3133 | goto out; | |
d61f82d0 | 3134 | |
79922b80 SRRH |
3135 | /* |
3136 | * If the ops uses a trampoline, then it needs to be | |
3137 | * tested first on update. | |
3138 | */ | |
e1effa01 | 3139 | ops->flags |= FTRACE_OPS_FL_REMOVING; |
79922b80 SRRH |
3140 | removed_ops = ops; |
3141 | ||
fef5aeee SRRH |
3142 | /* The trampoline logic checks the old hashes */ |
3143 | ops->old_hash.filter_hash = ops->func_hash->filter_hash; | |
3144 | ops->old_hash.notrace_hash = ops->func_hash->notrace_hash; | |
3145 | ||
d61f82d0 | 3146 | ftrace_run_update_code(command); |
a4c35ed2 | 3147 | |
84bde62c SRRH |
3148 | /* |
3149 | * If there's no more ops registered with ftrace, run a | |
3150 | * sanity check to make sure all rec flags are cleared. | |
3151 | */ | |
f86f4180 CZ |
3152 | if (rcu_dereference_protected(ftrace_ops_list, |
3153 | lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { | |
84bde62c SRRH |
3154 | struct ftrace_page *pg; |
3155 | struct dyn_ftrace *rec; | |
3156 | ||
3157 | do_for_each_ftrace_rec(pg, rec) { | |
e11b521a | 3158 | if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_NOCLEAR_FLAGS)) |
84bde62c SRRH |
3159 | pr_warn(" %pS flags:%lx\n", |
3160 | (void *)rec->ip, rec->flags); | |
3161 | } while_for_each_ftrace_rec(); | |
3162 | } | |
3163 | ||
fef5aeee SRRH |
3164 | ops->old_hash.filter_hash = NULL; |
3165 | ops->old_hash.notrace_hash = NULL; | |
3166 | ||
3167 | removed_ops = NULL; | |
e1effa01 | 3168 | ops->flags &= ~FTRACE_OPS_FL_REMOVING; |
79922b80 | 3169 | |
0e792b89 | 3170 | out: |
a4c35ed2 SRRH |
3171 | /* |
3172 | * Dynamic ops may be freed, we must make sure that all | |
3173 | * callers are done before leaving this function. | |
a4c35ed2 | 3174 | */ |
b3a88803 | 3175 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC) { |
0598e4f0 SRV |
3176 | /* |
3177 | * We need to do a hard force of sched synchronization. | |
3178 | * This is because we use preempt_disable() to do RCU, but | |
3179 | * the function tracers can be called where RCU is not watching | |
3180 | * (like before user_exit()). We can not rely on the RCU | |
3181 | * infrastructure to do the synchronization, thus we must do it | |
3182 | * ourselves. | |
3183 | */ | |
e5a971d7 | 3184 | synchronize_rcu_tasks_rude(); |
a4c35ed2 | 3185 | |
0598e4f0 | 3186 | /* |
fdda88d3 | 3187 | * When the kernel is preemptive, tasks can be preempted |
0598e4f0 SRV |
3188 | * while on a ftrace trampoline. Just scheduling a task on |
3189 | * a CPU is not good enough to flush them. Calling | |
f2cc020d | 3190 | * synchronize_rcu_tasks() will wait for those tasks to |
0598e4f0 SRV |
3191 | * execute and either schedule voluntarily or enter user space. |
3192 | */ | |
30c93704 | 3193 | if (IS_ENABLED(CONFIG_PREEMPTION)) |
0598e4f0 SRV |
3194 | synchronize_rcu_tasks(); |
3195 | ||
fc0ea795 | 3196 | ftrace_trampoline_free(ops); |
a4c35ed2 SRRH |
3197 | } |
3198 | ||
8a56d776 | 3199 | return 0; |
3d083395 SR |
3200 | } |
3201 | ||
a5a1d1c2 | 3202 | static u64 ftrace_update_time; |
3d083395 | 3203 | unsigned long ftrace_update_tot_cnt; |
da537f0a SRV |
3204 | unsigned long ftrace_number_of_pages; |
3205 | unsigned long ftrace_number_of_groups; | |
3d083395 | 3206 | |
8c4f3c3f | 3207 | static inline int ops_traces_mod(struct ftrace_ops *ops) |
f7bc8b61 | 3208 | { |
8c4f3c3f SRRH |
3209 | /* |
3210 | * Filter_hash being empty will default to trace module. | |
3211 | * But notrace hash requires a test of individual module functions. | |
3212 | */ | |
33b7f99c SRRH |
3213 | return ftrace_hash_empty(ops->func_hash->filter_hash) && |
3214 | ftrace_hash_empty(ops->func_hash->notrace_hash); | |
8c4f3c3f SRRH |
3215 | } |
3216 | ||
1dc43cf0 | 3217 | static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs) |
3d083395 | 3218 | { |
67ccddf8 | 3219 | bool init_nop = ftrace_need_init_nop(); |
85ae32ae | 3220 | struct ftrace_page *pg; |
e94142a6 | 3221 | struct dyn_ftrace *p; |
a5a1d1c2 | 3222 | u64 start, stop; |
1dc43cf0 | 3223 | unsigned long update_cnt = 0; |
b7ffffbb | 3224 | unsigned long rec_flags = 0; |
85ae32ae | 3225 | int i; |
f7bc8b61 | 3226 | |
b7ffffbb SRRH |
3227 | start = ftrace_now(raw_smp_processor_id()); |
3228 | ||
f7bc8b61 | 3229 | /* |
b7ffffbb SRRH |
3230 | * When a module is loaded, this function is called to convert |
3231 | * the calls to mcount in its text to nops, and also to create | |
3232 | * an entry in the ftrace data. Now, if ftrace is activated | |
3233 | * after this call, but before the module sets its text to | |
3234 | * read-only, the modification of enabling ftrace can fail if | |
3235 | * the read-only is done while ftrace is converting the calls. | |
3236 | * To prevent this, the module's records are set as disabled | |
3237 | * and will be enabled after the call to set the module's text | |
3238 | * to read-only. | |
f7bc8b61 | 3239 | */ |
b7ffffbb SRRH |
3240 | if (mod) |
3241 | rec_flags |= FTRACE_FL_DISABLED; | |
3d083395 | 3242 | |
1dc43cf0 | 3243 | for (pg = new_pgs; pg; pg = pg->next) { |
3d083395 | 3244 | |
85ae32ae | 3245 | for (i = 0; i < pg->index; i++) { |
8c4f3c3f | 3246 | |
85ae32ae SR |
3247 | /* If something went wrong, bail without enabling anything */ |
3248 | if (unlikely(ftrace_disabled)) | |
3249 | return -1; | |
f22f9a89 | 3250 | |
85ae32ae | 3251 | p = &pg->records[i]; |
b7ffffbb | 3252 | p->flags = rec_flags; |
f22f9a89 | 3253 | |
85ae32ae SR |
3254 | /* |
3255 | * Do the initial record conversion from mcount jump | |
3256 | * to the NOP instructions. | |
3257 | */ | |
67ccddf8 | 3258 | if (init_nop && !ftrace_nop_initialize(mod, p)) |
85ae32ae | 3259 | break; |
5cb084bb | 3260 | |
1dc43cf0 | 3261 | update_cnt++; |
5cb084bb | 3262 | } |
3d083395 SR |
3263 | } |
3264 | ||
750ed1a4 | 3265 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 | 3266 | ftrace_update_time = stop - start; |
1dc43cf0 | 3267 | ftrace_update_tot_cnt += update_cnt; |
3d083395 | 3268 | |
16444a8a ACM |
3269 | return 0; |
3270 | } | |
3271 | ||
a7900875 | 3272 | static int ftrace_allocate_records(struct ftrace_page *pg, int count) |
3c1720f0 | 3273 | { |
a7900875 | 3274 | int order; |
7ba031e8 | 3275 | int pages; |
3c1720f0 | 3276 | int cnt; |
3c1720f0 | 3277 | |
a7900875 SR |
3278 | if (WARN_ON(!count)) |
3279 | return -EINVAL; | |
3280 | ||
ceaaa129 | 3281 | /* We want to fill as much as possible, with no empty pages */ |
b40c6eab | 3282 | pages = DIV_ROUND_UP(count, ENTRIES_PER_PAGE); |
ceaaa129 | 3283 | order = fls(pages) - 1; |
3c1720f0 | 3284 | |
a7900875 SR |
3285 | again: |
3286 | pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order); | |
3c1720f0 | 3287 | |
a7900875 SR |
3288 | if (!pg->records) { |
3289 | /* if we can't allocate this size, try something smaller */ | |
3290 | if (!order) | |
3291 | return -ENOMEM; | |
bcea02b0 | 3292 | order--; |
a7900875 SR |
3293 | goto again; |
3294 | } | |
3c1720f0 | 3295 | |
da537f0a SRV |
3296 | ftrace_number_of_pages += 1 << order; |
3297 | ftrace_number_of_groups++; | |
3298 | ||
a7900875 | 3299 | cnt = (PAGE_SIZE << order) / ENTRY_SIZE; |
db42523b | 3300 | pg->order = order; |
3c1720f0 | 3301 | |
a7900875 SR |
3302 | if (cnt > count) |
3303 | cnt = count; | |
3304 | ||
3305 | return cnt; | |
3306 | } | |
3307 | ||
3308 | static struct ftrace_page * | |
3309 | ftrace_allocate_pages(unsigned long num_to_init) | |
3310 | { | |
3311 | struct ftrace_page *start_pg; | |
3312 | struct ftrace_page *pg; | |
a7900875 SR |
3313 | int cnt; |
3314 | ||
3315 | if (!num_to_init) | |
9efb85c5 | 3316 | return NULL; |
a7900875 SR |
3317 | |
3318 | start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL); | |
3319 | if (!pg) | |
3320 | return NULL; | |
3321 | ||
3322 | /* | |
3323 | * Try to allocate as much as possible in one continues | |
3324 | * location that fills in all of the space. We want to | |
3325 | * waste as little space as possible. | |
3326 | */ | |
3327 | for (;;) { | |
3328 | cnt = ftrace_allocate_records(pg, num_to_init); | |
3329 | if (cnt < 0) | |
3330 | goto free_pages; | |
3331 | ||
3332 | num_to_init -= cnt; | |
3333 | if (!num_to_init) | |
3c1720f0 SR |
3334 | break; |
3335 | ||
a7900875 SR |
3336 | pg->next = kzalloc(sizeof(*pg), GFP_KERNEL); |
3337 | if (!pg->next) | |
3338 | goto free_pages; | |
3339 | ||
3c1720f0 SR |
3340 | pg = pg->next; |
3341 | } | |
3342 | ||
a7900875 SR |
3343 | return start_pg; |
3344 | ||
3345 | free_pages: | |
1f61be00 NK |
3346 | pg = start_pg; |
3347 | while (pg) { | |
db42523b LT |
3348 | if (pg->records) { |
3349 | free_pages((unsigned long)pg->records, pg->order); | |
3350 | ftrace_number_of_pages -= 1 << pg->order; | |
3351 | } | |
a7900875 SR |
3352 | start_pg = pg->next; |
3353 | kfree(pg); | |
3354 | pg = start_pg; | |
da537f0a | 3355 | ftrace_number_of_groups--; |
a7900875 SR |
3356 | } |
3357 | pr_info("ftrace: FAILED to allocate memory for functions\n"); | |
3358 | return NULL; | |
3359 | } | |
3360 | ||
5072c59f SR |
3361 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ |
3362 | ||
3363 | struct ftrace_iterator { | |
98c4fd04 | 3364 | loff_t pos; |
4aeb6967 | 3365 | loff_t func_pos; |
5985ea8b | 3366 | loff_t mod_pos; |
4aeb6967 SR |
3367 | struct ftrace_page *pg; |
3368 | struct dyn_ftrace *func; | |
3369 | struct ftrace_func_probe *probe; | |
eee8ded1 | 3370 | struct ftrace_func_entry *probe_entry; |
4aeb6967 | 3371 | struct trace_parser parser; |
1cf41dd7 | 3372 | struct ftrace_hash *hash; |
33dc9b12 | 3373 | struct ftrace_ops *ops; |
5985ea8b SRV |
3374 | struct trace_array *tr; |
3375 | struct list_head *mod_list; | |
eee8ded1 | 3376 | int pidx; |
4aeb6967 SR |
3377 | int idx; |
3378 | unsigned flags; | |
5072c59f SR |
3379 | }; |
3380 | ||
8fc0c701 | 3381 | static void * |
eee8ded1 | 3382 | t_probe_next(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
3383 | { |
3384 | struct ftrace_iterator *iter = m->private; | |
d2afd57a | 3385 | struct trace_array *tr = iter->ops->private; |
04ec7bb6 | 3386 | struct list_head *func_probes; |
eee8ded1 SRV |
3387 | struct ftrace_hash *hash; |
3388 | struct list_head *next; | |
4aeb6967 | 3389 | struct hlist_node *hnd = NULL; |
8fc0c701 | 3390 | struct hlist_head *hhd; |
eee8ded1 | 3391 | int size; |
8fc0c701 | 3392 | |
8fc0c701 | 3393 | (*pos)++; |
98c4fd04 | 3394 | iter->pos = *pos; |
8fc0c701 | 3395 | |
04ec7bb6 | 3396 | if (!tr) |
8fc0c701 SR |
3397 | return NULL; |
3398 | ||
04ec7bb6 SRV |
3399 | func_probes = &tr->func_probes; |
3400 | if (list_empty(func_probes)) | |
8fc0c701 SR |
3401 | return NULL; |
3402 | ||
eee8ded1 | 3403 | if (!iter->probe) { |
04ec7bb6 | 3404 | next = func_probes->next; |
7b60f3d8 | 3405 | iter->probe = list_entry(next, struct ftrace_func_probe, list); |
eee8ded1 SRV |
3406 | } |
3407 | ||
3408 | if (iter->probe_entry) | |
3409 | hnd = &iter->probe_entry->hlist; | |
3410 | ||
3411 | hash = iter->probe->ops.func_hash->filter_hash; | |
7bd46644 | 3412 | |
372e0d01 SRV |
3413 | /* |
3414 | * A probe being registered may temporarily have an empty hash | |
3415 | * and it's at the end of the func_probes list. | |
3416 | */ | |
3417 | if (!hash || hash == EMPTY_HASH) | |
7bd46644 NR |
3418 | return NULL; |
3419 | ||
eee8ded1 SRV |
3420 | size = 1 << hash->size_bits; |
3421 | ||
3422 | retry: | |
3423 | if (iter->pidx >= size) { | |
04ec7bb6 | 3424 | if (iter->probe->list.next == func_probes) |
eee8ded1 SRV |
3425 | return NULL; |
3426 | next = iter->probe->list.next; | |
7b60f3d8 | 3427 | iter->probe = list_entry(next, struct ftrace_func_probe, list); |
eee8ded1 SRV |
3428 | hash = iter->probe->ops.func_hash->filter_hash; |
3429 | size = 1 << hash->size_bits; | |
3430 | iter->pidx = 0; | |
3431 | } | |
3432 | ||
3433 | hhd = &hash->buckets[iter->pidx]; | |
8fc0c701 SR |
3434 | |
3435 | if (hlist_empty(hhd)) { | |
eee8ded1 | 3436 | iter->pidx++; |
8fc0c701 SR |
3437 | hnd = NULL; |
3438 | goto retry; | |
3439 | } | |
3440 | ||
3441 | if (!hnd) | |
3442 | hnd = hhd->first; | |
3443 | else { | |
3444 | hnd = hnd->next; | |
3445 | if (!hnd) { | |
eee8ded1 | 3446 | iter->pidx++; |
8fc0c701 SR |
3447 | goto retry; |
3448 | } | |
3449 | } | |
3450 | ||
4aeb6967 SR |
3451 | if (WARN_ON_ONCE(!hnd)) |
3452 | return NULL; | |
3453 | ||
eee8ded1 | 3454 | iter->probe_entry = hlist_entry(hnd, struct ftrace_func_entry, hlist); |
4aeb6967 SR |
3455 | |
3456 | return iter; | |
8fc0c701 SR |
3457 | } |
3458 | ||
eee8ded1 | 3459 | static void *t_probe_start(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
3460 | { |
3461 | struct ftrace_iterator *iter = m->private; | |
3462 | void *p = NULL; | |
d82d6244 LZ |
3463 | loff_t l; |
3464 | ||
eee8ded1 | 3465 | if (!(iter->flags & FTRACE_ITER_DO_PROBES)) |
69a3083c SR |
3466 | return NULL; |
3467 | ||
5985ea8b | 3468 | if (iter->mod_pos > *pos) |
2bccfffd | 3469 | return NULL; |
8fc0c701 | 3470 | |
eee8ded1 SRV |
3471 | iter->probe = NULL; |
3472 | iter->probe_entry = NULL; | |
3473 | iter->pidx = 0; | |
5985ea8b | 3474 | for (l = 0; l <= (*pos - iter->mod_pos); ) { |
eee8ded1 | 3475 | p = t_probe_next(m, &l); |
d82d6244 LZ |
3476 | if (!p) |
3477 | break; | |
3478 | } | |
4aeb6967 SR |
3479 | if (!p) |
3480 | return NULL; | |
3481 | ||
98c4fd04 | 3482 | /* Only set this if we have an item */ |
eee8ded1 | 3483 | iter->flags |= FTRACE_ITER_PROBE; |
98c4fd04 | 3484 | |
4aeb6967 | 3485 | return iter; |
8fc0c701 SR |
3486 | } |
3487 | ||
4aeb6967 | 3488 | static int |
eee8ded1 | 3489 | t_probe_show(struct seq_file *m, struct ftrace_iterator *iter) |
8fc0c701 | 3490 | { |
eee8ded1 | 3491 | struct ftrace_func_entry *probe_entry; |
7b60f3d8 SRV |
3492 | struct ftrace_probe_ops *probe_ops; |
3493 | struct ftrace_func_probe *probe; | |
8fc0c701 | 3494 | |
eee8ded1 SRV |
3495 | probe = iter->probe; |
3496 | probe_entry = iter->probe_entry; | |
8fc0c701 | 3497 | |
eee8ded1 | 3498 | if (WARN_ON_ONCE(!probe || !probe_entry)) |
4aeb6967 | 3499 | return -EIO; |
8fc0c701 | 3500 | |
7b60f3d8 | 3501 | probe_ops = probe->probe_ops; |
809dcf29 | 3502 | |
7b60f3d8 | 3503 | if (probe_ops->print) |
6e444319 | 3504 | return probe_ops->print(m, probe_entry->ip, probe_ops, probe->data); |
8fc0c701 | 3505 | |
7b60f3d8 SRV |
3506 | seq_printf(m, "%ps:%ps\n", (void *)probe_entry->ip, |
3507 | (void *)probe_ops->func); | |
8fc0c701 SR |
3508 | |
3509 | return 0; | |
3510 | } | |
3511 | ||
5985ea8b SRV |
3512 | static void * |
3513 | t_mod_next(struct seq_file *m, loff_t *pos) | |
3514 | { | |
3515 | struct ftrace_iterator *iter = m->private; | |
3516 | struct trace_array *tr = iter->tr; | |
3517 | ||
3518 | (*pos)++; | |
3519 | iter->pos = *pos; | |
3520 | ||
3521 | iter->mod_list = iter->mod_list->next; | |
3522 | ||
3523 | if (iter->mod_list == &tr->mod_trace || | |
3524 | iter->mod_list == &tr->mod_notrace) { | |
3525 | iter->flags &= ~FTRACE_ITER_MOD; | |
3526 | return NULL; | |
3527 | } | |
3528 | ||
3529 | iter->mod_pos = *pos; | |
3530 | ||
3531 | return iter; | |
3532 | } | |
3533 | ||
3534 | static void *t_mod_start(struct seq_file *m, loff_t *pos) | |
3535 | { | |
3536 | struct ftrace_iterator *iter = m->private; | |
3537 | void *p = NULL; | |
3538 | loff_t l; | |
3539 | ||
3540 | if (iter->func_pos > *pos) | |
3541 | return NULL; | |
3542 | ||
3543 | iter->mod_pos = iter->func_pos; | |
3544 | ||
3545 | /* probes are only available if tr is set */ | |
3546 | if (!iter->tr) | |
3547 | return NULL; | |
3548 | ||
3549 | for (l = 0; l <= (*pos - iter->func_pos); ) { | |
3550 | p = t_mod_next(m, &l); | |
3551 | if (!p) | |
3552 | break; | |
3553 | } | |
3554 | if (!p) { | |
3555 | iter->flags &= ~FTRACE_ITER_MOD; | |
3556 | return t_probe_start(m, pos); | |
3557 | } | |
3558 | ||
3559 | /* Only set this if we have an item */ | |
3560 | iter->flags |= FTRACE_ITER_MOD; | |
3561 | ||
3562 | return iter; | |
3563 | } | |
3564 | ||
3565 | static int | |
3566 | t_mod_show(struct seq_file *m, struct ftrace_iterator *iter) | |
3567 | { | |
3568 | struct ftrace_mod_load *ftrace_mod; | |
3569 | struct trace_array *tr = iter->tr; | |
3570 | ||
3571 | if (WARN_ON_ONCE(!iter->mod_list) || | |
3572 | iter->mod_list == &tr->mod_trace || | |
3573 | iter->mod_list == &tr->mod_notrace) | |
3574 | return -EIO; | |
3575 | ||
3576 | ftrace_mod = list_entry(iter->mod_list, struct ftrace_mod_load, list); | |
3577 | ||
3578 | if (ftrace_mod->func) | |
3579 | seq_printf(m, "%s", ftrace_mod->func); | |
3580 | else | |
3581 | seq_putc(m, '*'); | |
3582 | ||
3583 | seq_printf(m, ":mod:%s\n", ftrace_mod->module); | |
3584 | ||
3585 | return 0; | |
3586 | } | |
3587 | ||
e309b41d | 3588 | static void * |
5bd84629 | 3589 | t_func_next(struct seq_file *m, loff_t *pos) |
5072c59f SR |
3590 | { |
3591 | struct ftrace_iterator *iter = m->private; | |
3592 | struct dyn_ftrace *rec = NULL; | |
3593 | ||
3594 | (*pos)++; | |
0c75a3ed | 3595 | |
5072c59f SR |
3596 | retry: |
3597 | if (iter->idx >= iter->pg->index) { | |
3598 | if (iter->pg->next) { | |
3599 | iter->pg = iter->pg->next; | |
3600 | iter->idx = 0; | |
3601 | goto retry; | |
3602 | } | |
3603 | } else { | |
3604 | rec = &iter->pg->records[iter->idx++]; | |
c20489da SRV |
3605 | if (((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) && |
3606 | !ftrace_lookup_ip(iter->hash, rec->ip)) || | |
647bcd03 SR |
3607 | |
3608 | ((iter->flags & FTRACE_ITER_ENABLED) && | |
e11b521a SRG |
3609 | !(rec->flags & FTRACE_FL_ENABLED)) || |
3610 | ||
3611 | ((iter->flags & FTRACE_ITER_TOUCHED) && | |
3612 | !(rec->flags & FTRACE_FL_TOUCHED))) { | |
647bcd03 | 3613 | |
5072c59f SR |
3614 | rec = NULL; |
3615 | goto retry; | |
3616 | } | |
3617 | } | |
3618 | ||
4aeb6967 | 3619 | if (!rec) |
5bd84629 | 3620 | return NULL; |
4aeb6967 | 3621 | |
5bd84629 | 3622 | iter->pos = iter->func_pos = *pos; |
4aeb6967 SR |
3623 | iter->func = rec; |
3624 | ||
3625 | return iter; | |
5072c59f SR |
3626 | } |
3627 | ||
5bd84629 SRV |
3628 | static void * |
3629 | t_next(struct seq_file *m, void *v, loff_t *pos) | |
3630 | { | |
3631 | struct ftrace_iterator *iter = m->private; | |
5985ea8b | 3632 | loff_t l = *pos; /* t_probe_start() must use original pos */ |
5bd84629 SRV |
3633 | void *ret; |
3634 | ||
3635 | if (unlikely(ftrace_disabled)) | |
3636 | return NULL; | |
3637 | ||
eee8ded1 SRV |
3638 | if (iter->flags & FTRACE_ITER_PROBE) |
3639 | return t_probe_next(m, pos); | |
5bd84629 | 3640 | |
5985ea8b SRV |
3641 | if (iter->flags & FTRACE_ITER_MOD) |
3642 | return t_mod_next(m, pos); | |
3643 | ||
5bd84629 | 3644 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
eee8ded1 | 3645 | /* next must increment pos, and t_probe_start does not */ |
5bd84629 | 3646 | (*pos)++; |
5985ea8b | 3647 | return t_mod_start(m, &l); |
5bd84629 SRV |
3648 | } |
3649 | ||
3650 | ret = t_func_next(m, pos); | |
3651 | ||
3652 | if (!ret) | |
5985ea8b | 3653 | return t_mod_start(m, &l); |
5bd84629 SRV |
3654 | |
3655 | return ret; | |
3656 | } | |
3657 | ||
98c4fd04 SR |
3658 | static void reset_iter_read(struct ftrace_iterator *iter) |
3659 | { | |
3660 | iter->pos = 0; | |
3661 | iter->func_pos = 0; | |
5985ea8b | 3662 | iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_PROBE | FTRACE_ITER_MOD); |
5072c59f SR |
3663 | } |
3664 | ||
3665 | static void *t_start(struct seq_file *m, loff_t *pos) | |
3666 | { | |
3667 | struct ftrace_iterator *iter = m->private; | |
3668 | void *p = NULL; | |
694ce0a5 | 3669 | loff_t l; |
5072c59f | 3670 | |
8fc0c701 | 3671 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
3672 | |
3673 | if (unlikely(ftrace_disabled)) | |
3674 | return NULL; | |
3675 | ||
98c4fd04 SR |
3676 | /* |
3677 | * If an lseek was done, then reset and start from beginning. | |
3678 | */ | |
3679 | if (*pos < iter->pos) | |
3680 | reset_iter_read(iter); | |
3681 | ||
0c75a3ed SR |
3682 | /* |
3683 | * For set_ftrace_filter reading, if we have the filter | |
3684 | * off, we can short cut and just print out that all | |
3685 | * functions are enabled. | |
3686 | */ | |
c20489da SRV |
3687 | if ((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) && |
3688 | ftrace_hash_empty(iter->hash)) { | |
43ff926a | 3689 | iter->func_pos = 1; /* Account for the message */ |
0c75a3ed | 3690 | if (*pos > 0) |
5985ea8b | 3691 | return t_mod_start(m, pos); |
0c75a3ed | 3692 | iter->flags |= FTRACE_ITER_PRINTALL; |
df091625 | 3693 | /* reset in case of seek/pread */ |
eee8ded1 | 3694 | iter->flags &= ~FTRACE_ITER_PROBE; |
0c75a3ed SR |
3695 | return iter; |
3696 | } | |
3697 | ||
5985ea8b SRV |
3698 | if (iter->flags & FTRACE_ITER_MOD) |
3699 | return t_mod_start(m, pos); | |
8fc0c701 | 3700 | |
98c4fd04 SR |
3701 | /* |
3702 | * Unfortunately, we need to restart at ftrace_pages_start | |
3703 | * every time we let go of the ftrace_mutex. This is because | |
3704 | * those pointers can change without the lock. | |
3705 | */ | |
694ce0a5 LZ |
3706 | iter->pg = ftrace_pages_start; |
3707 | iter->idx = 0; | |
3708 | for (l = 0; l <= *pos; ) { | |
5bd84629 | 3709 | p = t_func_next(m, &l); |
694ce0a5 LZ |
3710 | if (!p) |
3711 | break; | |
50cdaf08 | 3712 | } |
5821e1b7 | 3713 | |
69a3083c | 3714 | if (!p) |
5985ea8b | 3715 | return t_mod_start(m, pos); |
4aeb6967 SR |
3716 | |
3717 | return iter; | |
5072c59f SR |
3718 | } |
3719 | ||
3720 | static void t_stop(struct seq_file *m, void *p) | |
3721 | { | |
8fc0c701 | 3722 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
3723 | } |
3724 | ||
15d5b02c SRRH |
3725 | void * __weak |
3726 | arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec) | |
3727 | { | |
3728 | return NULL; | |
3729 | } | |
3730 | ||
3731 | static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops, | |
3732 | struct dyn_ftrace *rec) | |
3733 | { | |
3734 | void *ptr; | |
3735 | ||
3736 | ptr = arch_ftrace_trampoline_func(ops, rec); | |
3737 | if (ptr) | |
3738 | seq_printf(m, " ->%pS", ptr); | |
3739 | } | |
3740 | ||
b39181f7 SRG |
3741 | #ifdef FTRACE_MCOUNT_MAX_OFFSET |
3742 | /* | |
3743 | * Weak functions can still have an mcount/fentry that is saved in | |
3744 | * the __mcount_loc section. These can be detected by having a | |
3745 | * symbol offset of greater than FTRACE_MCOUNT_MAX_OFFSET, as the | |
3746 | * symbol found by kallsyms is not the function that the mcount/fentry | |
3747 | * is part of. The offset is much greater in these cases. | |
3748 | * | |
3749 | * Test the record to make sure that the ip points to a valid kallsyms | |
3750 | * and if not, mark it disabled. | |
3751 | */ | |
3752 | static int test_for_valid_rec(struct dyn_ftrace *rec) | |
3753 | { | |
3754 | char str[KSYM_SYMBOL_LEN]; | |
3755 | unsigned long offset; | |
3756 | const char *ret; | |
3757 | ||
3758 | ret = kallsyms_lookup(rec->ip, NULL, &offset, NULL, str); | |
3759 | ||
3760 | /* Weak functions can cause invalid addresses */ | |
3761 | if (!ret || offset > FTRACE_MCOUNT_MAX_OFFSET) { | |
3762 | rec->flags |= FTRACE_FL_DISABLED; | |
3763 | return 0; | |
3764 | } | |
3765 | return 1; | |
3766 | } | |
3767 | ||
3768 | static struct workqueue_struct *ftrace_check_wq __initdata; | |
3769 | static struct work_struct ftrace_check_work __initdata; | |
3770 | ||
3771 | /* | |
3772 | * Scan all the mcount/fentry entries to make sure they are valid. | |
3773 | */ | |
3774 | static __init void ftrace_check_work_func(struct work_struct *work) | |
3775 | { | |
3776 | struct ftrace_page *pg; | |
3777 | struct dyn_ftrace *rec; | |
3778 | ||
3779 | mutex_lock(&ftrace_lock); | |
3780 | do_for_each_ftrace_rec(pg, rec) { | |
3781 | test_for_valid_rec(rec); | |
3782 | } while_for_each_ftrace_rec(); | |
3783 | mutex_unlock(&ftrace_lock); | |
3784 | } | |
3785 | ||
3786 | static int __init ftrace_check_for_weak_functions(void) | |
3787 | { | |
3788 | INIT_WORK(&ftrace_check_work, ftrace_check_work_func); | |
3789 | ||
3790 | ftrace_check_wq = alloc_workqueue("ftrace_check_wq", WQ_UNBOUND, 0); | |
3791 | ||
3792 | queue_work(ftrace_check_wq, &ftrace_check_work); | |
3793 | return 0; | |
3794 | } | |
3795 | ||
3796 | static int __init ftrace_check_sync(void) | |
3797 | { | |
3798 | /* Make sure the ftrace_check updates are finished */ | |
3799 | if (ftrace_check_wq) | |
3800 | destroy_workqueue(ftrace_check_wq); | |
3801 | return 0; | |
3802 | } | |
3803 | ||
3804 | late_initcall_sync(ftrace_check_sync); | |
3805 | subsys_initcall(ftrace_check_for_weak_functions); | |
3806 | ||
3807 | static int print_rec(struct seq_file *m, unsigned long ip) | |
3808 | { | |
3809 | unsigned long offset; | |
3810 | char str[KSYM_SYMBOL_LEN]; | |
3811 | char *modname; | |
3812 | const char *ret; | |
3813 | ||
3814 | ret = kallsyms_lookup(ip, NULL, &offset, &modname, str); | |
3815 | /* Weak functions can cause invalid addresses */ | |
3816 | if (!ret || offset > FTRACE_MCOUNT_MAX_OFFSET) { | |
3817 | snprintf(str, KSYM_SYMBOL_LEN, "%s_%ld", | |
3818 | FTRACE_INVALID_FUNCTION, offset); | |
3819 | ret = NULL; | |
3820 | } | |
3821 | ||
3822 | seq_puts(m, str); | |
3823 | if (modname) | |
3824 | seq_printf(m, " [%s]", modname); | |
3825 | return ret == NULL ? -1 : 0; | |
3826 | } | |
3827 | #else | |
3828 | static inline int test_for_valid_rec(struct dyn_ftrace *rec) | |
3829 | { | |
3830 | return 1; | |
3831 | } | |
3832 | ||
3833 | static inline int print_rec(struct seq_file *m, unsigned long ip) | |
3834 | { | |
3835 | seq_printf(m, "%ps", (void *)ip); | |
3836 | return 0; | |
3837 | } | |
3838 | #endif | |
3839 | ||
5072c59f SR |
3840 | static int t_show(struct seq_file *m, void *v) |
3841 | { | |
0c75a3ed | 3842 | struct ftrace_iterator *iter = m->private; |
4aeb6967 | 3843 | struct dyn_ftrace *rec; |
5072c59f | 3844 | |
eee8ded1 SRV |
3845 | if (iter->flags & FTRACE_ITER_PROBE) |
3846 | return t_probe_show(m, iter); | |
8fc0c701 | 3847 | |
5985ea8b SRV |
3848 | if (iter->flags & FTRACE_ITER_MOD) |
3849 | return t_mod_show(m, iter); | |
3850 | ||
0c75a3ed | 3851 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
8c006cf7 | 3852 | if (iter->flags & FTRACE_ITER_NOTRACE) |
fa6f0cc7 | 3853 | seq_puts(m, "#### no functions disabled ####\n"); |
8c006cf7 | 3854 | else |
fa6f0cc7 | 3855 | seq_puts(m, "#### all functions enabled ####\n"); |
0c75a3ed SR |
3856 | return 0; |
3857 | } | |
3858 | ||
4aeb6967 SR |
3859 | rec = iter->func; |
3860 | ||
5072c59f SR |
3861 | if (!rec) |
3862 | return 0; | |
3863 | ||
b39181f7 SRG |
3864 | if (print_rec(m, rec->ip)) { |
3865 | /* This should only happen when a rec is disabled */ | |
3866 | WARN_ON_ONCE(!(rec->flags & FTRACE_FL_DISABLED)); | |
3867 | seq_putc(m, '\n'); | |
3868 | return 0; | |
3869 | } | |
3870 | ||
e11b521a | 3871 | if (iter->flags & (FTRACE_ITER_ENABLED | FTRACE_ITER_TOUCHED)) { |
030f4e1c | 3872 | struct ftrace_ops *ops; |
15d5b02c | 3873 | |
6ce2c04f | 3874 | seq_printf(m, " (%ld)%s%s%s%s%s", |
0376bde1 | 3875 | ftrace_rec_count(rec), |
f8b8be8a | 3876 | rec->flags & FTRACE_FL_REGS ? " R" : " ", |
763e34e7 | 3877 | rec->flags & FTRACE_FL_IPMODIFY ? " I" : " ", |
cbad0fb2 | 3878 | rec->flags & FTRACE_FL_DIRECT ? " D" : " ", |
6ce2c04f SRG |
3879 | rec->flags & FTRACE_FL_CALL_OPS ? " O" : " ", |
3880 | rec->flags & FTRACE_FL_MODIFIED ? " M " : " "); | |
9674b2fa | 3881 | if (rec->flags & FTRACE_FL_TRAMP_EN) { |
5fecaa04 | 3882 | ops = ftrace_find_tramp_ops_any(rec); |
39daa7b9 SRRH |
3883 | if (ops) { |
3884 | do { | |
3885 | seq_printf(m, "\ttramp: %pS (%pS)", | |
3886 | (void *)ops->trampoline, | |
3887 | (void *)ops->func); | |
030f4e1c | 3888 | add_trampoline_func(m, ops, rec); |
39daa7b9 SRRH |
3889 | ops = ftrace_find_tramp_ops_next(rec, ops); |
3890 | } while (ops); | |
3891 | } else | |
fa6f0cc7 | 3892 | seq_puts(m, "\ttramp: ERROR!"); |
030f4e1c SRRH |
3893 | } else { |
3894 | add_trampoline_func(m, NULL, rec); | |
9674b2fa | 3895 | } |
cbad0fb2 MR |
3896 | if (rec->flags & FTRACE_FL_CALL_OPS_EN) { |
3897 | ops = ftrace_find_unique_ops(rec); | |
3898 | if (ops) { | |
3899 | seq_printf(m, "\tops: %pS (%pS)", | |
3900 | ops, ops->func); | |
3901 | } else { | |
3902 | seq_puts(m, "\tops: ERROR!"); | |
3903 | } | |
3904 | } | |
763e34e7 SRV |
3905 | if (rec->flags & FTRACE_FL_DIRECT) { |
3906 | unsigned long direct; | |
3907 | ||
ff205766 | 3908 | direct = ftrace_find_rec_direct(rec->ip); |
763e34e7 SRV |
3909 | if (direct) |
3910 | seq_printf(m, "\n\tdirect-->%pS", (void *)direct); | |
3911 | } | |
026bb845 | 3912 | } |
9674b2fa | 3913 | |
fa6f0cc7 | 3914 | seq_putc(m, '\n'); |
5072c59f SR |
3915 | |
3916 | return 0; | |
3917 | } | |
3918 | ||
88e9d34c | 3919 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
3920 | .start = t_start, |
3921 | .next = t_next, | |
3922 | .stop = t_stop, | |
3923 | .show = t_show, | |
3924 | }; | |
3925 | ||
e309b41d | 3926 | static int |
5072c59f SR |
3927 | ftrace_avail_open(struct inode *inode, struct file *file) |
3928 | { | |
3929 | struct ftrace_iterator *iter; | |
17911ff3 SRV |
3930 | int ret; |
3931 | ||
3932 | ret = security_locked_down(LOCKDOWN_TRACEFS); | |
3933 | if (ret) | |
3934 | return ret; | |
5072c59f | 3935 | |
4eebcc81 SR |
3936 | if (unlikely(ftrace_disabled)) |
3937 | return -ENODEV; | |
3938 | ||
50e18b94 | 3939 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
c1bc5919 SRV |
3940 | if (!iter) |
3941 | return -ENOMEM; | |
5072c59f | 3942 | |
c1bc5919 SRV |
3943 | iter->pg = ftrace_pages_start; |
3944 | iter->ops = &global_ops; | |
3945 | ||
3946 | return 0; | |
5072c59f SR |
3947 | } |
3948 | ||
647bcd03 SR |
3949 | static int |
3950 | ftrace_enabled_open(struct inode *inode, struct file *file) | |
3951 | { | |
3952 | struct ftrace_iterator *iter; | |
647bcd03 | 3953 | |
17911ff3 SRV |
3954 | /* |
3955 | * This shows us what functions are currently being | |
3956 | * traced and by what. Not sure if we want lockdown | |
3957 | * to hide such critical information for an admin. | |
3958 | * Although, perhaps it can show information we don't | |
3959 | * want people to see, but if something is tracing | |
3960 | * something, we probably want to know about it. | |
3961 | */ | |
3962 | ||
50e18b94 | 3963 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
c1bc5919 SRV |
3964 | if (!iter) |
3965 | return -ENOMEM; | |
647bcd03 | 3966 | |
c1bc5919 SRV |
3967 | iter->pg = ftrace_pages_start; |
3968 | iter->flags = FTRACE_ITER_ENABLED; | |
3969 | iter->ops = &global_ops; | |
3970 | ||
3971 | return 0; | |
647bcd03 SR |
3972 | } |
3973 | ||
e11b521a SRG |
3974 | static int |
3975 | ftrace_touched_open(struct inode *inode, struct file *file) | |
3976 | { | |
3977 | struct ftrace_iterator *iter; | |
3978 | ||
3979 | /* | |
3980 | * This shows us what functions have ever been enabled | |
3981 | * (traced, direct, patched, etc). Not sure if we want lockdown | |
3982 | * to hide such critical information for an admin. | |
3983 | * Although, perhaps it can show information we don't | |
3984 | * want people to see, but if something had traced | |
3985 | * something, we probably want to know about it. | |
3986 | */ | |
3987 | ||
3988 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); | |
3989 | if (!iter) | |
3990 | return -ENOMEM; | |
3991 | ||
3992 | iter->pg = ftrace_pages_start; | |
3993 | iter->flags = FTRACE_ITER_TOUCHED; | |
3994 | iter->ops = &global_ops; | |
3995 | ||
3996 | return 0; | |
3997 | } | |
3998 | ||
fc13cb0c SR |
3999 | /** |
4000 | * ftrace_regex_open - initialize function tracer filter files | |
4001 | * @ops: The ftrace_ops that hold the hash filters | |
4002 | * @flag: The type of filter to process | |
4003 | * @inode: The inode, usually passed in to your open routine | |
4004 | * @file: The file, usually passed in to your open routine | |
4005 | * | |
4006 | * ftrace_regex_open() initializes the filter files for the | |
4007 | * @ops. Depending on @flag it may process the filter hash or | |
4008 | * the notrace hash of @ops. With this called from the open | |
4009 | * routine, you can use ftrace_filter_write() for the write | |
4010 | * routine if @flag has FTRACE_ITER_FILTER set, or | |
4011 | * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set. | |
098c879e | 4012 | * tracing_lseek() should be used as the lseek routine, and |
fc13cb0c SR |
4013 | * release must call ftrace_regex_release(). |
4014 | */ | |
4015 | int | |
f45948e8 | 4016 | ftrace_regex_open(struct ftrace_ops *ops, int flag, |
1cf41dd7 | 4017 | struct inode *inode, struct file *file) |
5072c59f SR |
4018 | { |
4019 | struct ftrace_iterator *iter; | |
f45948e8 | 4020 | struct ftrace_hash *hash; |
673feb9d SRV |
4021 | struct list_head *mod_head; |
4022 | struct trace_array *tr = ops->private; | |
9ef16693 | 4023 | int ret = -ENOMEM; |
5072c59f | 4024 | |
f04f24fb MH |
4025 | ftrace_ops_init(ops); |
4026 | ||
4eebcc81 SR |
4027 | if (unlikely(ftrace_disabled)) |
4028 | return -ENODEV; | |
4029 | ||
8530dec6 | 4030 | if (tracing_check_open_get_tr(tr)) |
9ef16693 SRV |
4031 | return -ENODEV; |
4032 | ||
5072c59f SR |
4033 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
4034 | if (!iter) | |
9ef16693 | 4035 | goto out; |
5072c59f | 4036 | |
9ef16693 SRV |
4037 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) |
4038 | goto out; | |
689fd8b6 | 4039 | |
3f2367ba MH |
4040 | iter->ops = ops; |
4041 | iter->flags = flag; | |
5985ea8b | 4042 | iter->tr = tr; |
3f2367ba | 4043 | |
33b7f99c | 4044 | mutex_lock(&ops->func_hash->regex_lock); |
3f2367ba | 4045 | |
673feb9d | 4046 | if (flag & FTRACE_ITER_NOTRACE) { |
33b7f99c | 4047 | hash = ops->func_hash->notrace_hash; |
5985ea8b | 4048 | mod_head = tr ? &tr->mod_notrace : NULL; |
673feb9d | 4049 | } else { |
33b7f99c | 4050 | hash = ops->func_hash->filter_hash; |
5985ea8b | 4051 | mod_head = tr ? &tr->mod_trace : NULL; |
673feb9d | 4052 | } |
f45948e8 | 4053 | |
5985ea8b SRV |
4054 | iter->mod_list = mod_head; |
4055 | ||
33dc9b12 | 4056 | if (file->f_mode & FMODE_WRITE) { |
ef2fbe16 NK |
4057 | const int size_bits = FTRACE_HASH_DEFAULT_BITS; |
4058 | ||
673feb9d | 4059 | if (file->f_flags & O_TRUNC) { |
ef2fbe16 | 4060 | iter->hash = alloc_ftrace_hash(size_bits); |
673feb9d SRV |
4061 | clear_ftrace_mod_list(mod_head); |
4062 | } else { | |
ef2fbe16 | 4063 | iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash); |
673feb9d | 4064 | } |
ef2fbe16 | 4065 | |
33dc9b12 SR |
4066 | if (!iter->hash) { |
4067 | trace_parser_put(&iter->parser); | |
3f2367ba | 4068 | goto out_unlock; |
33dc9b12 | 4069 | } |
c20489da SRV |
4070 | } else |
4071 | iter->hash = hash; | |
1cf41dd7 | 4072 | |
9ef16693 SRV |
4073 | ret = 0; |
4074 | ||
5072c59f SR |
4075 | if (file->f_mode & FMODE_READ) { |
4076 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
4077 | |
4078 | ret = seq_open(file, &show_ftrace_seq_ops); | |
4079 | if (!ret) { | |
4080 | struct seq_file *m = file->private_data; | |
4081 | m->private = iter; | |
79fe249c | 4082 | } else { |
33dc9b12 SR |
4083 | /* Failed */ |
4084 | free_ftrace_hash(iter->hash); | |
79fe249c | 4085 | trace_parser_put(&iter->parser); |
79fe249c | 4086 | } |
5072c59f SR |
4087 | } else |
4088 | file->private_data = iter; | |
3f2367ba MH |
4089 | |
4090 | out_unlock: | |
33b7f99c | 4091 | mutex_unlock(&ops->func_hash->regex_lock); |
5072c59f | 4092 | |
9ef16693 SRV |
4093 | out: |
4094 | if (ret) { | |
4095 | kfree(iter); | |
4096 | if (tr) | |
4097 | trace_array_put(tr); | |
4098 | } | |
4099 | ||
5072c59f SR |
4100 | return ret; |
4101 | } | |
4102 | ||
41c52c0d SR |
4103 | static int |
4104 | ftrace_filter_open(struct inode *inode, struct file *file) | |
4105 | { | |
e3b3e2e8 SRRH |
4106 | struct ftrace_ops *ops = inode->i_private; |
4107 | ||
17911ff3 | 4108 | /* Checks for tracefs lockdown */ |
e3b3e2e8 | 4109 | return ftrace_regex_open(ops, |
eee8ded1 | 4110 | FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES, |
69a3083c | 4111 | inode, file); |
41c52c0d SR |
4112 | } |
4113 | ||
4114 | static int | |
4115 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
4116 | { | |
e3b3e2e8 SRRH |
4117 | struct ftrace_ops *ops = inode->i_private; |
4118 | ||
17911ff3 | 4119 | /* Checks for tracefs lockdown */ |
e3b3e2e8 | 4120 | return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE, |
1cf41dd7 | 4121 | inode, file); |
41c52c0d SR |
4122 | } |
4123 | ||
3ba00929 DS |
4124 | /* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */ |
4125 | struct ftrace_glob { | |
4126 | char *search; | |
4127 | unsigned len; | |
4128 | int type; | |
4129 | }; | |
4130 | ||
7132e2d6 TJB |
4131 | /* |
4132 | * If symbols in an architecture don't correspond exactly to the user-visible | |
4133 | * name of what they represent, it is possible to define this function to | |
4134 | * perform the necessary adjustments. | |
4135 | */ | |
4136 | char * __weak arch_ftrace_match_adjust(char *str, const char *search) | |
4137 | { | |
4138 | return str; | |
4139 | } | |
4140 | ||
3ba00929 | 4141 | static int ftrace_match(char *str, struct ftrace_glob *g) |
9f4801e3 | 4142 | { |
9f4801e3 | 4143 | int matched = 0; |
751e9983 | 4144 | int slen; |
9f4801e3 | 4145 | |
7132e2d6 TJB |
4146 | str = arch_ftrace_match_adjust(str, g->search); |
4147 | ||
3ba00929 | 4148 | switch (g->type) { |
9f4801e3 | 4149 | case MATCH_FULL: |
3ba00929 | 4150 | if (strcmp(str, g->search) == 0) |
9f4801e3 SR |
4151 | matched = 1; |
4152 | break; | |
4153 | case MATCH_FRONT_ONLY: | |
3ba00929 | 4154 | if (strncmp(str, g->search, g->len) == 0) |
9f4801e3 SR |
4155 | matched = 1; |
4156 | break; | |
4157 | case MATCH_MIDDLE_ONLY: | |
3ba00929 | 4158 | if (strstr(str, g->search)) |
9f4801e3 SR |
4159 | matched = 1; |
4160 | break; | |
4161 | case MATCH_END_ONLY: | |
751e9983 | 4162 | slen = strlen(str); |
3ba00929 DS |
4163 | if (slen >= g->len && |
4164 | memcmp(str + slen - g->len, g->search, g->len) == 0) | |
9f4801e3 SR |
4165 | matched = 1; |
4166 | break; | |
60f1d5e3 MH |
4167 | case MATCH_GLOB: |
4168 | if (glob_match(g->search, str)) | |
4169 | matched = 1; | |
4170 | break; | |
9f4801e3 SR |
4171 | } |
4172 | ||
4173 | return matched; | |
4174 | } | |
4175 | ||
b448c4e3 | 4176 | static int |
f0a3b154 | 4177 | enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter) |
996e87be | 4178 | { |
b448c4e3 | 4179 | struct ftrace_func_entry *entry; |
b448c4e3 SR |
4180 | int ret = 0; |
4181 | ||
1cf41dd7 | 4182 | entry = ftrace_lookup_ip(hash, rec->ip); |
f0a3b154 | 4183 | if (clear_filter) { |
1cf41dd7 SR |
4184 | /* Do nothing if it doesn't exist */ |
4185 | if (!entry) | |
4186 | return 0; | |
b448c4e3 | 4187 | |
33dc9b12 | 4188 | free_hash_entry(hash, entry); |
1cf41dd7 SR |
4189 | } else { |
4190 | /* Do nothing if it exists */ | |
4191 | if (entry) | |
4192 | return 0; | |
b448c4e3 | 4193 | |
1cf41dd7 | 4194 | ret = add_hash_entry(hash, rec->ip); |
b448c4e3 SR |
4195 | } |
4196 | return ret; | |
996e87be SR |
4197 | } |
4198 | ||
f79b3f33 SRV |
4199 | static int |
4200 | add_rec_by_index(struct ftrace_hash *hash, struct ftrace_glob *func_g, | |
4201 | int clear_filter) | |
4202 | { | |
4203 | long index = simple_strtoul(func_g->search, NULL, 0); | |
4204 | struct ftrace_page *pg; | |
4205 | struct dyn_ftrace *rec; | |
4206 | ||
4207 | /* The index starts at 1 */ | |
4208 | if (--index < 0) | |
4209 | return 0; | |
4210 | ||
4211 | do_for_each_ftrace_rec(pg, rec) { | |
4212 | if (pg->index <= index) { | |
4213 | index -= pg->index; | |
4214 | /* this is a double loop, break goes to the next page */ | |
4215 | break; | |
4216 | } | |
4217 | rec = &pg->records[index]; | |
4218 | enter_record(hash, rec, clear_filter); | |
4219 | return 1; | |
4220 | } while_for_each_ftrace_rec(); | |
4221 | return 0; | |
4222 | } | |
4223 | ||
b39181f7 SRG |
4224 | #ifdef FTRACE_MCOUNT_MAX_OFFSET |
4225 | static int lookup_ip(unsigned long ip, char **modname, char *str) | |
4226 | { | |
4227 | unsigned long offset; | |
4228 | ||
4229 | kallsyms_lookup(ip, NULL, &offset, modname, str); | |
4230 | if (offset > FTRACE_MCOUNT_MAX_OFFSET) | |
4231 | return -1; | |
4232 | return 0; | |
4233 | } | |
4234 | #else | |
4235 | static int lookup_ip(unsigned long ip, char **modname, char *str) | |
4236 | { | |
4237 | kallsyms_lookup(ip, NULL, NULL, modname, str); | |
4238 | return 0; | |
4239 | } | |
4240 | #endif | |
4241 | ||
64e7c440 | 4242 | static int |
0b507e1e DS |
4243 | ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g, |
4244 | struct ftrace_glob *mod_g, int exclude_mod) | |
64e7c440 SR |
4245 | { |
4246 | char str[KSYM_SYMBOL_LEN]; | |
b9df92d2 SR |
4247 | char *modname; |
4248 | ||
b39181f7 SRG |
4249 | if (lookup_ip(rec->ip, &modname, str)) { |
4250 | /* This should only happen when a rec is disabled */ | |
4251 | WARN_ON_ONCE(system_state == SYSTEM_RUNNING && | |
4252 | !(rec->flags & FTRACE_FL_DISABLED)); | |
4253 | return 0; | |
4254 | } | |
b9df92d2 | 4255 | |
0b507e1e DS |
4256 | if (mod_g) { |
4257 | int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0; | |
4258 | ||
4259 | /* blank module name to match all modules */ | |
4260 | if (!mod_g->len) { | |
4261 | /* blank module globbing: modname xor exclude_mod */ | |
77c0edde | 4262 | if (!exclude_mod != !modname) |
0b507e1e DS |
4263 | goto func_match; |
4264 | return 0; | |
4265 | } | |
4266 | ||
77c0edde SRV |
4267 | /* |
4268 | * exclude_mod is set to trace everything but the given | |
4269 | * module. If it is set and the module matches, then | |
4270 | * return 0. If it is not set, and the module doesn't match | |
4271 | * also return 0. Otherwise, check the function to see if | |
4272 | * that matches. | |
4273 | */ | |
4274 | if (!mod_matches == !exclude_mod) | |
b9df92d2 | 4275 | return 0; |
0b507e1e | 4276 | func_match: |
b9df92d2 | 4277 | /* blank search means to match all funcs in the mod */ |
3ba00929 | 4278 | if (!func_g->len) |
b9df92d2 SR |
4279 | return 1; |
4280 | } | |
64e7c440 | 4281 | |
3ba00929 | 4282 | return ftrace_match(str, func_g); |
64e7c440 SR |
4283 | } |
4284 | ||
1cf41dd7 | 4285 | static int |
3ba00929 | 4286 | match_records(struct ftrace_hash *hash, char *func, int len, char *mod) |
9f4801e3 | 4287 | { |
9f4801e3 SR |
4288 | struct ftrace_page *pg; |
4289 | struct dyn_ftrace *rec; | |
3ba00929 | 4290 | struct ftrace_glob func_g = { .type = MATCH_FULL }; |
0b507e1e DS |
4291 | struct ftrace_glob mod_g = { .type = MATCH_FULL }; |
4292 | struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL; | |
4293 | int exclude_mod = 0; | |
311d16da | 4294 | int found = 0; |
b448c4e3 | 4295 | int ret; |
2e028c4f | 4296 | int clear_filter = 0; |
9f4801e3 | 4297 | |
0b507e1e | 4298 | if (func) { |
3ba00929 DS |
4299 | func_g.type = filter_parse_regex(func, len, &func_g.search, |
4300 | &clear_filter); | |
4301 | func_g.len = strlen(func_g.search); | |
b9df92d2 | 4302 | } |
9f4801e3 | 4303 | |
0b507e1e DS |
4304 | if (mod) { |
4305 | mod_g.type = filter_parse_regex(mod, strlen(mod), | |
4306 | &mod_g.search, &exclude_mod); | |
4307 | mod_g.len = strlen(mod_g.search); | |
b9df92d2 | 4308 | } |
9f4801e3 | 4309 | |
52baf119 | 4310 | mutex_lock(&ftrace_lock); |
265c831c | 4311 | |
b9df92d2 SR |
4312 | if (unlikely(ftrace_disabled)) |
4313 | goto out_unlock; | |
9f4801e3 | 4314 | |
f79b3f33 SRV |
4315 | if (func_g.type == MATCH_INDEX) { |
4316 | found = add_rec_by_index(hash, &func_g, clear_filter); | |
4317 | goto out_unlock; | |
4318 | } | |
4319 | ||
265c831c | 4320 | do_for_each_ftrace_rec(pg, rec) { |
546fece4 SRRH |
4321 | |
4322 | if (rec->flags & FTRACE_FL_DISABLED) | |
4323 | continue; | |
4324 | ||
0b507e1e | 4325 | if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) { |
f0a3b154 | 4326 | ret = enter_record(hash, rec, clear_filter); |
b448c4e3 SR |
4327 | if (ret < 0) { |
4328 | found = ret; | |
4329 | goto out_unlock; | |
4330 | } | |
311d16da | 4331 | found = 1; |
265c831c | 4332 | } |
d0b24b4e | 4333 | cond_resched(); |
265c831c | 4334 | } while_for_each_ftrace_rec(); |
b9df92d2 | 4335 | out_unlock: |
52baf119 | 4336 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
4337 | |
4338 | return found; | |
5072c59f SR |
4339 | } |
4340 | ||
64e7c440 | 4341 | static int |
1cf41dd7 | 4342 | ftrace_match_records(struct ftrace_hash *hash, char *buff, int len) |
64e7c440 | 4343 | { |
f0a3b154 | 4344 | return match_records(hash, buff, len, NULL); |
64e7c440 SR |
4345 | } |
4346 | ||
e16b35dd SRV |
4347 | static void ftrace_ops_update_code(struct ftrace_ops *ops, |
4348 | struct ftrace_ops_hash *old_hash) | |
4349 | { | |
4350 | struct ftrace_ops *op; | |
4351 | ||
4352 | if (!ftrace_enabled) | |
4353 | return; | |
4354 | ||
4355 | if (ops->flags & FTRACE_OPS_FL_ENABLED) { | |
4356 | ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash); | |
4357 | return; | |
4358 | } | |
4359 | ||
4360 | /* | |
4361 | * If this is the shared global_ops filter, then we need to | |
4362 | * check if there is another ops that shares it, is enabled. | |
4363 | * If so, we still need to run the modify code. | |
4364 | */ | |
4365 | if (ops->func_hash != &global_ops.local_hash) | |
4366 | return; | |
4367 | ||
4368 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
4369 | if (op->func_hash == &global_ops.local_hash && | |
4370 | op->flags & FTRACE_OPS_FL_ENABLED) { | |
4371 | ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash); | |
4372 | /* Only need to do this once */ | |
4373 | return; | |
4374 | } | |
4375 | } while_for_each_ftrace_op(op); | |
4376 | } | |
4377 | ||
4378 | static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops, | |
4379 | struct ftrace_hash **orig_hash, | |
4380 | struct ftrace_hash *hash, | |
4381 | int enable) | |
4382 | { | |
4383 | struct ftrace_ops_hash old_hash_ops; | |
4384 | struct ftrace_hash *old_hash; | |
4385 | int ret; | |
4386 | ||
4387 | old_hash = *orig_hash; | |
4388 | old_hash_ops.filter_hash = ops->func_hash->filter_hash; | |
4389 | old_hash_ops.notrace_hash = ops->func_hash->notrace_hash; | |
4390 | ret = ftrace_hash_move(ops, enable, orig_hash, hash); | |
4391 | if (!ret) { | |
4392 | ftrace_ops_update_code(ops, &old_hash_ops); | |
4393 | free_ftrace_hash_rcu(old_hash); | |
4394 | } | |
4395 | return ret; | |
4396 | } | |
64e7c440 | 4397 | |
673feb9d SRV |
4398 | static bool module_exists(const char *module) |
4399 | { | |
4400 | /* All modules have the symbol __this_module */ | |
0f5e5a3a | 4401 | static const char this_mod[] = "__this_module"; |
419e9fe5 | 4402 | char modname[MAX_PARAM_PREFIX_LEN + sizeof(this_mod) + 2]; |
673feb9d SRV |
4403 | unsigned long val; |
4404 | int n; | |
4405 | ||
419e9fe5 | 4406 | n = snprintf(modname, sizeof(modname), "%s:%s", module, this_mod); |
673feb9d | 4407 | |
419e9fe5 | 4408 | if (n > sizeof(modname) - 1) |
673feb9d SRV |
4409 | return false; |
4410 | ||
4411 | val = module_kallsyms_lookup_name(modname); | |
4412 | return val != 0; | |
4413 | } | |
4414 | ||
4415 | static int cache_mod(struct trace_array *tr, | |
4416 | const char *func, char *module, int enable) | |
4417 | { | |
4418 | struct ftrace_mod_load *ftrace_mod, *n; | |
4419 | struct list_head *head = enable ? &tr->mod_trace : &tr->mod_notrace; | |
4420 | int ret; | |
4421 | ||
4422 | mutex_lock(&ftrace_lock); | |
4423 | ||
4424 | /* We do not cache inverse filters */ | |
4425 | if (func[0] == '!') { | |
4426 | func++; | |
4427 | ret = -EINVAL; | |
4428 | ||
4429 | /* Look to remove this hash */ | |
4430 | list_for_each_entry_safe(ftrace_mod, n, head, list) { | |
4431 | if (strcmp(ftrace_mod->module, module) != 0) | |
4432 | continue; | |
4433 | ||
4434 | /* no func matches all */ | |
44925dff | 4435 | if (strcmp(func, "*") == 0 || |
673feb9d SRV |
4436 | (ftrace_mod->func && |
4437 | strcmp(ftrace_mod->func, func) == 0)) { | |
4438 | ret = 0; | |
4439 | free_ftrace_mod(ftrace_mod); | |
4440 | continue; | |
4441 | } | |
4442 | } | |
4443 | goto out; | |
4444 | } | |
4445 | ||
4446 | ret = -EINVAL; | |
4447 | /* We only care about modules that have not been loaded yet */ | |
4448 | if (module_exists(module)) | |
4449 | goto out; | |
4450 | ||
4451 | /* Save this string off, and execute it when the module is loaded */ | |
4452 | ret = ftrace_add_mod(tr, func, module, enable); | |
4453 | out: | |
4454 | mutex_unlock(&ftrace_lock); | |
4455 | ||
4456 | return ret; | |
4457 | } | |
4458 | ||
d7fbf8df SRV |
4459 | static int |
4460 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, | |
4461 | int reset, int enable); | |
4462 | ||
69449bbd | 4463 | #ifdef CONFIG_MODULES |
d7fbf8df SRV |
4464 | static void process_mod_list(struct list_head *head, struct ftrace_ops *ops, |
4465 | char *mod, bool enable) | |
4466 | { | |
4467 | struct ftrace_mod_load *ftrace_mod, *n; | |
4468 | struct ftrace_hash **orig_hash, *new_hash; | |
4469 | LIST_HEAD(process_mods); | |
4470 | char *func; | |
d7fbf8df SRV |
4471 | |
4472 | mutex_lock(&ops->func_hash->regex_lock); | |
4473 | ||
4474 | if (enable) | |
4475 | orig_hash = &ops->func_hash->filter_hash; | |
4476 | else | |
4477 | orig_hash = &ops->func_hash->notrace_hash; | |
4478 | ||
4479 | new_hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, | |
4480 | *orig_hash); | |
4481 | if (!new_hash) | |
3b58a3c7 | 4482 | goto out; /* warn? */ |
d7fbf8df SRV |
4483 | |
4484 | mutex_lock(&ftrace_lock); | |
4485 | ||
4486 | list_for_each_entry_safe(ftrace_mod, n, head, list) { | |
4487 | ||
4488 | if (strcmp(ftrace_mod->module, mod) != 0) | |
4489 | continue; | |
4490 | ||
4491 | if (ftrace_mod->func) | |
4492 | func = kstrdup(ftrace_mod->func, GFP_KERNEL); | |
4493 | else | |
4494 | func = kstrdup("*", GFP_KERNEL); | |
4495 | ||
4496 | if (!func) /* warn? */ | |
4497 | continue; | |
4498 | ||
3ecda644 | 4499 | list_move(&ftrace_mod->list, &process_mods); |
d7fbf8df SRV |
4500 | |
4501 | /* Use the newly allocated func, as it may be "*" */ | |
4502 | kfree(ftrace_mod->func); | |
4503 | ftrace_mod->func = func; | |
4504 | } | |
4505 | ||
4506 | mutex_unlock(&ftrace_lock); | |
4507 | ||
4508 | list_for_each_entry_safe(ftrace_mod, n, &process_mods, list) { | |
4509 | ||
4510 | func = ftrace_mod->func; | |
4511 | ||
4512 | /* Grabs ftrace_lock, which is why we have this extra step */ | |
4513 | match_records(new_hash, func, strlen(func), mod); | |
4514 | free_ftrace_mod(ftrace_mod); | |
4515 | } | |
4516 | ||
8c08f0d5 SRV |
4517 | if (enable && list_empty(head)) |
4518 | new_hash->flags &= ~FTRACE_HASH_FL_MOD; | |
4519 | ||
d7fbf8df SRV |
4520 | mutex_lock(&ftrace_lock); |
4521 | ||
045e269c | 4522 | ftrace_hash_move_and_update_ops(ops, orig_hash, |
d7fbf8df SRV |
4523 | new_hash, enable); |
4524 | mutex_unlock(&ftrace_lock); | |
4525 | ||
3b58a3c7 | 4526 | out: |
d7fbf8df SRV |
4527 | mutex_unlock(&ops->func_hash->regex_lock); |
4528 | ||
4529 | free_ftrace_hash(new_hash); | |
4530 | } | |
4531 | ||
4532 | static void process_cached_mods(const char *mod_name) | |
4533 | { | |
4534 | struct trace_array *tr; | |
4535 | char *mod; | |
4536 | ||
4537 | mod = kstrdup(mod_name, GFP_KERNEL); | |
4538 | if (!mod) | |
4539 | return; | |
4540 | ||
4541 | mutex_lock(&trace_types_lock); | |
4542 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
4543 | if (!list_empty(&tr->mod_trace)) | |
4544 | process_mod_list(&tr->mod_trace, tr->ops, mod, true); | |
4545 | if (!list_empty(&tr->mod_notrace)) | |
4546 | process_mod_list(&tr->mod_notrace, tr->ops, mod, false); | |
4547 | } | |
4548 | mutex_unlock(&trace_types_lock); | |
4549 | ||
4550 | kfree(mod); | |
4551 | } | |
69449bbd | 4552 | #endif |
d7fbf8df | 4553 | |
f6180773 SR |
4554 | /* |
4555 | * We register the module command as a template to show others how | |
4556 | * to register the a command as well. | |
4557 | */ | |
4558 | ||
4559 | static int | |
04ec7bb6 | 4560 | ftrace_mod_callback(struct trace_array *tr, struct ftrace_hash *hash, |
673feb9d | 4561 | char *func_orig, char *cmd, char *module, int enable) |
f6180773 | 4562 | { |
673feb9d | 4563 | char *func; |
5e3949f0 | 4564 | int ret; |
f6180773 | 4565 | |
673feb9d SRV |
4566 | /* match_records() modifies func, and we need the original */ |
4567 | func = kstrdup(func_orig, GFP_KERNEL); | |
4568 | if (!func) | |
4569 | return -ENOMEM; | |
4570 | ||
f6180773 SR |
4571 | /* |
4572 | * cmd == 'mod' because we only registered this func | |
4573 | * for the 'mod' ftrace_func_command. | |
4574 | * But if you register one func with multiple commands, | |
4575 | * you can tell which command was used by the cmd | |
4576 | * parameter. | |
4577 | */ | |
f0a3b154 | 4578 | ret = match_records(hash, func, strlen(func), module); |
673feb9d SRV |
4579 | kfree(func); |
4580 | ||
b448c4e3 | 4581 | if (!ret) |
673feb9d | 4582 | return cache_mod(tr, func_orig, module, enable); |
b448c4e3 SR |
4583 | if (ret < 0) |
4584 | return ret; | |
b448c4e3 | 4585 | return 0; |
f6180773 SR |
4586 | } |
4587 | ||
4588 | static struct ftrace_func_command ftrace_mod_cmd = { | |
4589 | .name = "mod", | |
4590 | .func = ftrace_mod_callback, | |
4591 | }; | |
4592 | ||
4593 | static int __init ftrace_mod_cmd_init(void) | |
4594 | { | |
4595 | return register_ftrace_command(&ftrace_mod_cmd); | |
4596 | } | |
6f415672 | 4597 | core_initcall(ftrace_mod_cmd_init); |
f6180773 | 4598 | |
2f5f6ad9 | 4599 | static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, |
d19ad077 | 4600 | struct ftrace_ops *op, struct ftrace_regs *fregs) |
59df055f | 4601 | { |
eee8ded1 | 4602 | struct ftrace_probe_ops *probe_ops; |
7b60f3d8 | 4603 | struct ftrace_func_probe *probe; |
59df055f | 4604 | |
7b60f3d8 SRV |
4605 | probe = container_of(op, struct ftrace_func_probe, ops); |
4606 | probe_ops = probe->probe_ops; | |
59df055f SR |
4607 | |
4608 | /* | |
4609 | * Disable preemption for these calls to prevent a RCU grace | |
4610 | * period. This syncs the hash iteration and freeing of items | |
4611 | * on the hash. rcu_read_lock is too dangerous here. | |
4612 | */ | |
5168ae50 | 4613 | preempt_disable_notrace(); |
6e444319 | 4614 | probe_ops->func(ip, parent_ip, probe->tr, probe_ops, probe->data); |
5168ae50 | 4615 | preempt_enable_notrace(); |
59df055f SR |
4616 | } |
4617 | ||
41794f19 SRV |
4618 | struct ftrace_func_map { |
4619 | struct ftrace_func_entry entry; | |
4620 | void *data; | |
59df055f SR |
4621 | }; |
4622 | ||
41794f19 SRV |
4623 | struct ftrace_func_mapper { |
4624 | struct ftrace_hash hash; | |
4625 | }; | |
59df055f | 4626 | |
41794f19 SRV |
4627 | /** |
4628 | * allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper | |
4629 | * | |
4630 | * Returns a ftrace_func_mapper descriptor that can be used to map ips to data. | |
4631 | */ | |
4632 | struct ftrace_func_mapper *allocate_ftrace_func_mapper(void) | |
59df055f | 4633 | { |
41794f19 | 4634 | struct ftrace_hash *hash; |
59df055f | 4635 | |
41794f19 SRV |
4636 | /* |
4637 | * The mapper is simply a ftrace_hash, but since the entries | |
4638 | * in the hash are not ftrace_func_entry type, we define it | |
4639 | * as a separate structure. | |
4640 | */ | |
4641 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); | |
4642 | return (struct ftrace_func_mapper *)hash; | |
4643 | } | |
59df055f | 4644 | |
41794f19 SRV |
4645 | /** |
4646 | * ftrace_func_mapper_find_ip - Find some data mapped to an ip | |
4647 | * @mapper: The mapper that has the ip maps | |
4648 | * @ip: the instruction pointer to find the data for | |
4649 | * | |
4650 | * Returns the data mapped to @ip if found otherwise NULL. The return | |
4651 | * is actually the address of the mapper data pointer. The address is | |
4652 | * returned for use cases where the data is no bigger than a long, and | |
4653 | * the user can use the data pointer as its data instead of having to | |
4654 | * allocate more memory for the reference. | |
4655 | */ | |
4656 | void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper, | |
4657 | unsigned long ip) | |
4658 | { | |
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 NULL; | |
b848914c | 4665 | |
41794f19 SRV |
4666 | map = (struct ftrace_func_map *)entry; |
4667 | return &map->data; | |
59df055f SR |
4668 | } |
4669 | ||
41794f19 SRV |
4670 | /** |
4671 | * ftrace_func_mapper_add_ip - Map some data to an ip | |
4672 | * @mapper: The mapper that has the ip maps | |
4673 | * @ip: The instruction pointer address to map @data to | |
4674 | * @data: The data to map to @ip | |
4675 | * | |
fdda88d3 | 4676 | * Returns 0 on success otherwise an error. |
41794f19 SRV |
4677 | */ |
4678 | int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper, | |
4679 | unsigned long ip, void *data) | |
59df055f | 4680 | { |
41794f19 SRV |
4681 | struct ftrace_func_entry *entry; |
4682 | struct ftrace_func_map *map; | |
59df055f | 4683 | |
41794f19 SRV |
4684 | entry = ftrace_lookup_ip(&mapper->hash, ip); |
4685 | if (entry) | |
4686 | return -EBUSY; | |
59df055f | 4687 | |
41794f19 SRV |
4688 | map = kmalloc(sizeof(*map), GFP_KERNEL); |
4689 | if (!map) | |
4690 | return -ENOMEM; | |
59df055f | 4691 | |
41794f19 SRV |
4692 | map->entry.ip = ip; |
4693 | map->data = data; | |
b848914c | 4694 | |
41794f19 | 4695 | __add_hash_entry(&mapper->hash, &map->entry); |
59df055f | 4696 | |
41794f19 SRV |
4697 | return 0; |
4698 | } | |
59df055f | 4699 | |
41794f19 SRV |
4700 | /** |
4701 | * ftrace_func_mapper_remove_ip - Remove an ip from the mapping | |
4702 | * @mapper: The mapper that has the ip maps | |
4703 | * @ip: The instruction pointer address to remove the data from | |
4704 | * | |
4705 | * Returns the data if it is found, otherwise NULL. | |
7d54c15c | 4706 | * Note, if the data pointer is used as the data itself, (see |
41794f19 SRV |
4707 | * ftrace_func_mapper_find_ip(), then the return value may be meaningless, |
4708 | * if the data pointer was set to zero. | |
4709 | */ | |
4710 | void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper, | |
4711 | unsigned long ip) | |
59df055f | 4712 | { |
41794f19 SRV |
4713 | struct ftrace_func_entry *entry; |
4714 | struct ftrace_func_map *map; | |
4715 | void *data; | |
4716 | ||
4717 | entry = ftrace_lookup_ip(&mapper->hash, ip); | |
4718 | if (!entry) | |
4719 | return NULL; | |
4720 | ||
4721 | map = (struct ftrace_func_map *)entry; | |
4722 | data = map->data; | |
4723 | ||
4724 | remove_hash_entry(&mapper->hash, entry); | |
59df055f | 4725 | kfree(entry); |
41794f19 SRV |
4726 | |
4727 | return data; | |
4728 | } | |
4729 | ||
4730 | /** | |
4731 | * free_ftrace_func_mapper - free a mapping of ips and data | |
4732 | * @mapper: The mapper that has the ip maps | |
4733 | * @free_func: A function to be called on each data item. | |
4734 | * | |
4735 | * This is used to free the function mapper. The @free_func is optional | |
4736 | * and can be used if the data needs to be freed as well. | |
4737 | */ | |
4738 | void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper, | |
4739 | ftrace_mapper_func free_func) | |
4740 | { | |
4741 | struct ftrace_func_entry *entry; | |
4742 | struct ftrace_func_map *map; | |
4743 | struct hlist_head *hhd; | |
04e03d9a WL |
4744 | int size, i; |
4745 | ||
4746 | if (!mapper) | |
4747 | return; | |
41794f19 SRV |
4748 | |
4749 | if (free_func && mapper->hash.count) { | |
04e03d9a | 4750 | size = 1 << mapper->hash.size_bits; |
41794f19 SRV |
4751 | for (i = 0; i < size; i++) { |
4752 | hhd = &mapper->hash.buckets[i]; | |
4753 | hlist_for_each_entry(entry, hhd, hlist) { | |
4754 | map = (struct ftrace_func_map *)entry; | |
4755 | free_func(map); | |
4756 | } | |
4757 | } | |
4758 | } | |
4759 | free_ftrace_hash(&mapper->hash); | |
4760 | } | |
4761 | ||
7b60f3d8 SRV |
4762 | static void release_probe(struct ftrace_func_probe *probe) |
4763 | { | |
4764 | struct ftrace_probe_ops *probe_ops; | |
4765 | ||
4766 | mutex_lock(&ftrace_lock); | |
4767 | ||
4768 | WARN_ON(probe->ref <= 0); | |
4769 | ||
4770 | /* Subtract the ref that was used to protect this instance */ | |
4771 | probe->ref--; | |
4772 | ||
4773 | if (!probe->ref) { | |
4774 | probe_ops = probe->probe_ops; | |
6e444319 SRV |
4775 | /* |
4776 | * Sending zero as ip tells probe_ops to free | |
4777 | * the probe->data itself | |
4778 | */ | |
4779 | if (probe_ops->free) | |
4780 | probe_ops->free(probe_ops, probe->tr, 0, probe->data); | |
7b60f3d8 SRV |
4781 | list_del(&probe->list); |
4782 | kfree(probe); | |
4783 | } | |
4784 | mutex_unlock(&ftrace_lock); | |
4785 | } | |
4786 | ||
4787 | static void acquire_probe_locked(struct ftrace_func_probe *probe) | |
4788 | { | |
4789 | /* | |
4790 | * Add one ref to keep it from being freed when releasing the | |
4791 | * ftrace_lock mutex. | |
4792 | */ | |
4793 | probe->ref++; | |
59df055f SR |
4794 | } |
4795 | ||
59df055f | 4796 | int |
04ec7bb6 | 4797 | register_ftrace_function_probe(char *glob, struct trace_array *tr, |
7b60f3d8 SRV |
4798 | struct ftrace_probe_ops *probe_ops, |
4799 | void *data) | |
59df055f | 4800 | { |
ba27d855 | 4801 | struct ftrace_func_probe *probe = NULL, *iter; |
1ec3a81a | 4802 | struct ftrace_func_entry *entry; |
1ec3a81a SRV |
4803 | struct ftrace_hash **orig_hash; |
4804 | struct ftrace_hash *old_hash; | |
e1df4cb6 | 4805 | struct ftrace_hash *hash; |
59df055f | 4806 | int count = 0; |
1ec3a81a | 4807 | int size; |
e1df4cb6 | 4808 | int ret; |
1ec3a81a | 4809 | int i; |
59df055f | 4810 | |
04ec7bb6 | 4811 | if (WARN_ON(!tr)) |
59df055f SR |
4812 | return -EINVAL; |
4813 | ||
1ec3a81a SRV |
4814 | /* We do not support '!' for function probes */ |
4815 | if (WARN_ON(glob[0] == '!')) | |
59df055f | 4816 | return -EINVAL; |
59df055f | 4817 | |
7485058e | 4818 | |
7b60f3d8 SRV |
4819 | mutex_lock(&ftrace_lock); |
4820 | /* Check if the probe_ops is already registered */ | |
ba27d855 JK |
4821 | list_for_each_entry(iter, &tr->func_probes, list) { |
4822 | if (iter->probe_ops == probe_ops) { | |
4823 | probe = iter; | |
7b60f3d8 | 4824 | break; |
ba27d855 | 4825 | } |
e1df4cb6 | 4826 | } |
ba27d855 | 4827 | if (!probe) { |
7b60f3d8 SRV |
4828 | probe = kzalloc(sizeof(*probe), GFP_KERNEL); |
4829 | if (!probe) { | |
4830 | mutex_unlock(&ftrace_lock); | |
4831 | return -ENOMEM; | |
4832 | } | |
4833 | probe->probe_ops = probe_ops; | |
4834 | probe->ops.func = function_trace_probe_call; | |
4835 | probe->tr = tr; | |
4836 | ftrace_ops_init(&probe->ops); | |
4837 | list_add(&probe->list, &tr->func_probes); | |
e1df4cb6 | 4838 | } |
59df055f | 4839 | |
7b60f3d8 | 4840 | acquire_probe_locked(probe); |
5ae0bf59 | 4841 | |
7b60f3d8 | 4842 | mutex_unlock(&ftrace_lock); |
59df055f | 4843 | |
372e0d01 SRV |
4844 | /* |
4845 | * Note, there's a small window here that the func_hash->filter_hash | |
fdda88d3 | 4846 | * may be NULL or empty. Need to be careful when reading the loop. |
372e0d01 | 4847 | */ |
7b60f3d8 | 4848 | mutex_lock(&probe->ops.func_hash->regex_lock); |
546fece4 | 4849 | |
7b60f3d8 | 4850 | orig_hash = &probe->ops.func_hash->filter_hash; |
1ec3a81a SRV |
4851 | old_hash = *orig_hash; |
4852 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); | |
59df055f | 4853 | |
5b0022dd NR |
4854 | if (!hash) { |
4855 | ret = -ENOMEM; | |
4856 | goto out; | |
4857 | } | |
4858 | ||
1ec3a81a | 4859 | ret = ftrace_match_records(hash, glob, strlen(glob)); |
59df055f | 4860 | |
1ec3a81a SRV |
4861 | /* Nothing found? */ |
4862 | if (!ret) | |
4863 | ret = -EINVAL; | |
59df055f | 4864 | |
1ec3a81a SRV |
4865 | if (ret < 0) |
4866 | goto out; | |
59df055f | 4867 | |
1ec3a81a SRV |
4868 | size = 1 << hash->size_bits; |
4869 | for (i = 0; i < size; i++) { | |
4870 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
4871 | if (ftrace_lookup_ip(old_hash, entry->ip)) | |
59df055f | 4872 | continue; |
1ec3a81a SRV |
4873 | /* |
4874 | * The caller might want to do something special | |
4875 | * for each function we find. We call the callback | |
4876 | * to give the caller an opportunity to do so. | |
4877 | */ | |
7b60f3d8 SRV |
4878 | if (probe_ops->init) { |
4879 | ret = probe_ops->init(probe_ops, tr, | |
6e444319 SRV |
4880 | entry->ip, data, |
4881 | &probe->data); | |
4882 | if (ret < 0) { | |
4883 | if (probe_ops->free && count) | |
4884 | probe_ops->free(probe_ops, tr, | |
4885 | 0, probe->data); | |
4886 | probe->data = NULL; | |
eee8ded1 | 4887 | goto out; |
6e444319 | 4888 | } |
59df055f | 4889 | } |
1ec3a81a | 4890 | count++; |
59df055f | 4891 | } |
1ec3a81a | 4892 | } |
59df055f | 4893 | |
1ec3a81a | 4894 | mutex_lock(&ftrace_lock); |
59df055f | 4895 | |
7b60f3d8 SRV |
4896 | if (!count) { |
4897 | /* Nothing was added? */ | |
4898 | ret = -EINVAL; | |
4899 | goto out_unlock; | |
4900 | } | |
e1df4cb6 | 4901 | |
7b60f3d8 SRV |
4902 | ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash, |
4903 | hash, 1); | |
1ec3a81a | 4904 | if (ret < 0) |
8d70725e | 4905 | goto err_unlock; |
8252ecf3 | 4906 | |
7b60f3d8 SRV |
4907 | /* One ref for each new function traced */ |
4908 | probe->ref += count; | |
8252ecf3 | 4909 | |
7b60f3d8 SRV |
4910 | if (!(probe->ops.flags & FTRACE_OPS_FL_ENABLED)) |
4911 | ret = ftrace_startup(&probe->ops, 0); | |
e1df4cb6 | 4912 | |
59df055f | 4913 | out_unlock: |
5ae0bf59 | 4914 | mutex_unlock(&ftrace_lock); |
8252ecf3 | 4915 | |
3296fc4e | 4916 | if (!ret) |
1ec3a81a | 4917 | ret = count; |
5ae0bf59 | 4918 | out: |
7b60f3d8 | 4919 | mutex_unlock(&probe->ops.func_hash->regex_lock); |
e1df4cb6 | 4920 | free_ftrace_hash(hash); |
59df055f | 4921 | |
7b60f3d8 | 4922 | release_probe(probe); |
59df055f | 4923 | |
1ec3a81a | 4924 | return ret; |
59df055f | 4925 | |
8d70725e | 4926 | err_unlock: |
7b60f3d8 | 4927 | if (!probe_ops->free || !count) |
8d70725e SRV |
4928 | goto out_unlock; |
4929 | ||
4930 | /* Failed to do the move, need to call the free functions */ | |
4931 | for (i = 0; i < size; i++) { | |
4932 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
4933 | if (ftrace_lookup_ip(old_hash, entry->ip)) | |
4934 | continue; | |
6e444319 | 4935 | probe_ops->free(probe_ops, tr, entry->ip, probe->data); |
8d70725e SRV |
4936 | } |
4937 | } | |
4938 | goto out_unlock; | |
59df055f SR |
4939 | } |
4940 | ||
d3d532d7 | 4941 | int |
7b60f3d8 SRV |
4942 | unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr, |
4943 | struct ftrace_probe_ops *probe_ops) | |
59df055f | 4944 | { |
ba27d855 | 4945 | struct ftrace_func_probe *probe = NULL, *iter; |
82cc4fc2 | 4946 | struct ftrace_ops_hash old_hash_ops; |
eee8ded1 | 4947 | struct ftrace_func_entry *entry; |
3ba00929 | 4948 | struct ftrace_glob func_g; |
1ec3a81a SRV |
4949 | struct ftrace_hash **orig_hash; |
4950 | struct ftrace_hash *old_hash; | |
1ec3a81a | 4951 | struct ftrace_hash *hash = NULL; |
b67bfe0d | 4952 | struct hlist_node *tmp; |
eee8ded1 | 4953 | struct hlist_head hhd; |
59df055f | 4954 | char str[KSYM_SYMBOL_LEN]; |
7b60f3d8 SRV |
4955 | int count = 0; |
4956 | int i, ret = -ENODEV; | |
eee8ded1 | 4957 | int size; |
59df055f | 4958 | |
cbab567c | 4959 | if (!glob || !strlen(glob) || !strcmp(glob, "*")) |
3ba00929 | 4960 | func_g.search = NULL; |
cbab567c | 4961 | else { |
59df055f SR |
4962 | int not; |
4963 | ||
3ba00929 DS |
4964 | func_g.type = filter_parse_regex(glob, strlen(glob), |
4965 | &func_g.search, ¬); | |
4966 | func_g.len = strlen(func_g.search); | |
59df055f | 4967 | |
b6887d79 | 4968 | /* we do not support '!' for function probes */ |
59df055f | 4969 | if (WARN_ON(not)) |
d3d532d7 | 4970 | return -EINVAL; |
59df055f SR |
4971 | } |
4972 | ||
7b60f3d8 SRV |
4973 | mutex_lock(&ftrace_lock); |
4974 | /* Check if the probe_ops is already registered */ | |
ba27d855 JK |
4975 | list_for_each_entry(iter, &tr->func_probes, list) { |
4976 | if (iter->probe_ops == probe_ops) { | |
4977 | probe = iter; | |
7b60f3d8 | 4978 | break; |
ba27d855 | 4979 | } |
59df055f | 4980 | } |
ba27d855 | 4981 | if (!probe) |
7b60f3d8 SRV |
4982 | goto err_unlock_ftrace; |
4983 | ||
4984 | ret = -EINVAL; | |
4985 | if (!(probe->ops.flags & FTRACE_OPS_FL_INITIALIZED)) | |
4986 | goto err_unlock_ftrace; | |
4987 | ||
4988 | acquire_probe_locked(probe); | |
4989 | ||
4990 | mutex_unlock(&ftrace_lock); | |
59df055f | 4991 | |
7b60f3d8 | 4992 | mutex_lock(&probe->ops.func_hash->regex_lock); |
1ec3a81a | 4993 | |
7b60f3d8 | 4994 | orig_hash = &probe->ops.func_hash->filter_hash; |
1ec3a81a SRV |
4995 | old_hash = *orig_hash; |
4996 | ||
1ec3a81a SRV |
4997 | if (ftrace_hash_empty(old_hash)) |
4998 | goto out_unlock; | |
e1df4cb6 | 4999 | |
82cc4fc2 SRV |
5000 | old_hash_ops.filter_hash = old_hash; |
5001 | /* Probes only have filters */ | |
5002 | old_hash_ops.notrace_hash = NULL; | |
5003 | ||
d3d532d7 | 5004 | ret = -ENOMEM; |
1ec3a81a | 5005 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); |
e1df4cb6 | 5006 | if (!hash) |
e1df4cb6 SRRH |
5007 | goto out_unlock; |
5008 | ||
eee8ded1 | 5009 | INIT_HLIST_HEAD(&hhd); |
59df055f | 5010 | |
eee8ded1 SRV |
5011 | size = 1 << hash->size_bits; |
5012 | for (i = 0; i < size; i++) { | |
5013 | hlist_for_each_entry_safe(entry, tmp, &hash->buckets[i], hlist) { | |
59df055f | 5014 | |
3ba00929 | 5015 | if (func_g.search) { |
59df055f SR |
5016 | kallsyms_lookup(entry->ip, NULL, NULL, |
5017 | NULL, str); | |
3ba00929 | 5018 | if (!ftrace_match(str, &func_g)) |
59df055f SR |
5019 | continue; |
5020 | } | |
7b60f3d8 | 5021 | count++; |
eee8ded1 SRV |
5022 | remove_hash_entry(hash, entry); |
5023 | hlist_add_head(&entry->hlist, &hhd); | |
59df055f SR |
5024 | } |
5025 | } | |
d3d532d7 SRV |
5026 | |
5027 | /* Nothing found? */ | |
7b60f3d8 | 5028 | if (!count) { |
d3d532d7 SRV |
5029 | ret = -EINVAL; |
5030 | goto out_unlock; | |
5031 | } | |
5032 | ||
3f2367ba | 5033 | mutex_lock(&ftrace_lock); |
1ec3a81a | 5034 | |
7b60f3d8 | 5035 | WARN_ON(probe->ref < count); |
eee8ded1 | 5036 | |
7b60f3d8 | 5037 | probe->ref -= count; |
1ec3a81a | 5038 | |
7b60f3d8 SRV |
5039 | if (ftrace_hash_empty(hash)) |
5040 | ftrace_shutdown(&probe->ops, 0); | |
5041 | ||
5042 | ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash, | |
1ec3a81a | 5043 | hash, 1); |
82cc4fc2 SRV |
5044 | |
5045 | /* still need to update the function call sites */ | |
1ec3a81a | 5046 | if (ftrace_enabled && !ftrace_hash_empty(hash)) |
7b60f3d8 | 5047 | ftrace_run_modify_code(&probe->ops, FTRACE_UPDATE_CALLS, |
82cc4fc2 | 5048 | &old_hash_ops); |
74401729 | 5049 | synchronize_rcu(); |
3296fc4e | 5050 | |
eee8ded1 SRV |
5051 | hlist_for_each_entry_safe(entry, tmp, &hhd, hlist) { |
5052 | hlist_del(&entry->hlist); | |
7b60f3d8 | 5053 | if (probe_ops->free) |
6e444319 | 5054 | probe_ops->free(probe_ops, tr, entry->ip, probe->data); |
eee8ded1 | 5055 | kfree(entry); |
7818b388 | 5056 | } |
3f2367ba | 5057 | mutex_unlock(&ftrace_lock); |
3ba00929 | 5058 | |
e1df4cb6 | 5059 | out_unlock: |
7b60f3d8 | 5060 | mutex_unlock(&probe->ops.func_hash->regex_lock); |
e1df4cb6 | 5061 | free_ftrace_hash(hash); |
59df055f | 5062 | |
7b60f3d8 | 5063 | release_probe(probe); |
59df055f | 5064 | |
7b60f3d8 | 5065 | return ret; |
59df055f | 5066 | |
7b60f3d8 SRV |
5067 | err_unlock_ftrace: |
5068 | mutex_unlock(&ftrace_lock); | |
d3d532d7 | 5069 | return ret; |
59df055f SR |
5070 | } |
5071 | ||
a0e6369e NR |
5072 | void clear_ftrace_function_probes(struct trace_array *tr) |
5073 | { | |
5074 | struct ftrace_func_probe *probe, *n; | |
5075 | ||
5076 | list_for_each_entry_safe(probe, n, &tr->func_probes, list) | |
5077 | unregister_ftrace_function_probe_func(NULL, tr, probe->probe_ops); | |
5078 | } | |
5079 | ||
f6180773 SR |
5080 | static LIST_HEAD(ftrace_commands); |
5081 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
5082 | ||
38de93ab TZ |
5083 | /* |
5084 | * Currently we only register ftrace commands from __init, so mark this | |
5085 | * __init too. | |
5086 | */ | |
5087 | __init int register_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
5088 | { |
5089 | struct ftrace_func_command *p; | |
5090 | int ret = 0; | |
5091 | ||
5092 | mutex_lock(&ftrace_cmd_mutex); | |
5093 | list_for_each_entry(p, &ftrace_commands, list) { | |
5094 | if (strcmp(cmd->name, p->name) == 0) { | |
5095 | ret = -EBUSY; | |
5096 | goto out_unlock; | |
5097 | } | |
5098 | } | |
5099 | list_add(&cmd->list, &ftrace_commands); | |
5100 | out_unlock: | |
5101 | mutex_unlock(&ftrace_cmd_mutex); | |
5102 | ||
5103 | return ret; | |
5104 | } | |
5105 | ||
38de93ab TZ |
5106 | /* |
5107 | * Currently we only unregister ftrace commands from __init, so mark | |
5108 | * this __init too. | |
5109 | */ | |
5110 | __init int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
5111 | { |
5112 | struct ftrace_func_command *p, *n; | |
5113 | int ret = -ENODEV; | |
5114 | ||
5115 | mutex_lock(&ftrace_cmd_mutex); | |
5116 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
5117 | if (strcmp(cmd->name, p->name) == 0) { | |
5118 | ret = 0; | |
5119 | list_del_init(&p->list); | |
5120 | goto out_unlock; | |
5121 | } | |
5122 | } | |
5123 | out_unlock: | |
5124 | mutex_unlock(&ftrace_cmd_mutex); | |
5125 | ||
5126 | return ret; | |
5127 | } | |
5128 | ||
04ec7bb6 | 5129 | static int ftrace_process_regex(struct ftrace_iterator *iter, |
33dc9b12 | 5130 | char *buff, int len, int enable) |
64e7c440 | 5131 | { |
04ec7bb6 | 5132 | struct ftrace_hash *hash = iter->hash; |
d2afd57a | 5133 | struct trace_array *tr = iter->ops->private; |
f6180773 | 5134 | char *func, *command, *next = buff; |
6a24a244 | 5135 | struct ftrace_func_command *p; |
0aff1c0c | 5136 | int ret = -EINVAL; |
64e7c440 SR |
5137 | |
5138 | func = strsep(&next, ":"); | |
5139 | ||
5140 | if (!next) { | |
1cf41dd7 | 5141 | ret = ftrace_match_records(hash, func, len); |
b448c4e3 SR |
5142 | if (!ret) |
5143 | ret = -EINVAL; | |
5144 | if (ret < 0) | |
5145 | return ret; | |
5146 | return 0; | |
64e7c440 SR |
5147 | } |
5148 | ||
f6180773 | 5149 | /* command found */ |
64e7c440 SR |
5150 | |
5151 | command = strsep(&next, ":"); | |
5152 | ||
f6180773 SR |
5153 | mutex_lock(&ftrace_cmd_mutex); |
5154 | list_for_each_entry(p, &ftrace_commands, list) { | |
5155 | if (strcmp(p->name, command) == 0) { | |
04ec7bb6 | 5156 | ret = p->func(tr, hash, func, command, next, enable); |
f6180773 SR |
5157 | goto out_unlock; |
5158 | } | |
64e7c440 | 5159 | } |
f6180773 SR |
5160 | out_unlock: |
5161 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 5162 | |
f6180773 | 5163 | return ret; |
64e7c440 SR |
5164 | } |
5165 | ||
e309b41d | 5166 | static ssize_t |
41c52c0d SR |
5167 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
5168 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
5169 | { |
5170 | struct ftrace_iterator *iter; | |
689fd8b6 | 5171 | struct trace_parser *parser; |
5172 | ssize_t ret, read; | |
5072c59f | 5173 | |
4ba7978e | 5174 | if (!cnt) |
5072c59f SR |
5175 | return 0; |
5176 | ||
5072c59f SR |
5177 | if (file->f_mode & FMODE_READ) { |
5178 | struct seq_file *m = file->private_data; | |
5179 | iter = m->private; | |
5180 | } else | |
5181 | iter = file->private_data; | |
5182 | ||
f04f24fb | 5183 | if (unlikely(ftrace_disabled)) |
3f2367ba MH |
5184 | return -ENODEV; |
5185 | ||
5186 | /* iter->hash is a local copy, so we don't need regex_lock */ | |
f04f24fb | 5187 | |
689fd8b6 | 5188 | parser = &iter->parser; |
5189 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 5190 | |
4ba7978e | 5191 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 5192 | !trace_parser_cont(parser)) { |
04ec7bb6 | 5193 | ret = ftrace_process_regex(iter, parser->buffer, |
689fd8b6 | 5194 | parser->idx, enable); |
313254a9 | 5195 | trace_parser_clear(parser); |
7c088b51 | 5196 | if (ret < 0) |
3f2367ba | 5197 | goto out; |
eda1e328 | 5198 | } |
5072c59f | 5199 | |
5072c59f | 5200 | ret = read; |
3f2367ba | 5201 | out: |
5072c59f SR |
5202 | return ret; |
5203 | } | |
5204 | ||
fc13cb0c | 5205 | ssize_t |
41c52c0d SR |
5206 | ftrace_filter_write(struct file *file, const char __user *ubuf, |
5207 | size_t cnt, loff_t *ppos) | |
5208 | { | |
5209 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
5210 | } | |
5211 | ||
fc13cb0c | 5212 | ssize_t |
41c52c0d SR |
5213 | ftrace_notrace_write(struct file *file, const char __user *ubuf, |
5214 | size_t cnt, loff_t *ppos) | |
5215 | { | |
5216 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
5217 | } | |
5218 | ||
33dc9b12 | 5219 | static int |
4f554e95 | 5220 | __ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) |
647664ea MH |
5221 | { |
5222 | struct ftrace_func_entry *entry; | |
5223 | ||
aebfd125 PZ |
5224 | ip = ftrace_location(ip); |
5225 | if (!ip) | |
647664ea MH |
5226 | return -EINVAL; |
5227 | ||
5228 | if (remove) { | |
5229 | entry = ftrace_lookup_ip(hash, ip); | |
5230 | if (!entry) | |
5231 | return -ENOENT; | |
5232 | free_hash_entry(hash, entry); | |
5233 | return 0; | |
5234 | } | |
5235 | ||
5236 | return add_hash_entry(hash, ip); | |
5237 | } | |
5238 | ||
4f554e95 JO |
5239 | static int |
5240 | ftrace_match_addr(struct ftrace_hash *hash, unsigned long *ips, | |
5241 | unsigned int cnt, int remove) | |
5242 | { | |
5243 | unsigned int i; | |
5244 | int err; | |
5245 | ||
5246 | for (i = 0; i < cnt; i++) { | |
5247 | err = __ftrace_match_addr(hash, ips[i], remove); | |
5248 | if (err) { | |
5249 | /* | |
5250 | * This expects the @hash is a temporary hash and if this | |
5251 | * fails the caller must free the @hash. | |
5252 | */ | |
5253 | return err; | |
5254 | } | |
5255 | } | |
5256 | return 0; | |
5257 | } | |
5258 | ||
647664ea MH |
5259 | static int |
5260 | ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, | |
4f554e95 JO |
5261 | unsigned long *ips, unsigned int cnt, |
5262 | int remove, int reset, int enable) | |
41c52c0d | 5263 | { |
33dc9b12 | 5264 | struct ftrace_hash **orig_hash; |
f45948e8 | 5265 | struct ftrace_hash *hash; |
33dc9b12 | 5266 | int ret; |
f45948e8 | 5267 | |
41c52c0d | 5268 | if (unlikely(ftrace_disabled)) |
33dc9b12 | 5269 | return -ENODEV; |
41c52c0d | 5270 | |
33b7f99c | 5271 | mutex_lock(&ops->func_hash->regex_lock); |
3f2367ba | 5272 | |
f45948e8 | 5273 | if (enable) |
33b7f99c | 5274 | orig_hash = &ops->func_hash->filter_hash; |
f45948e8 | 5275 | else |
33b7f99c | 5276 | orig_hash = &ops->func_hash->notrace_hash; |
33dc9b12 | 5277 | |
b972cc58 WN |
5278 | if (reset) |
5279 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); | |
5280 | else | |
5281 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
5282 | ||
3f2367ba MH |
5283 | if (!hash) { |
5284 | ret = -ENOMEM; | |
5285 | goto out_regex_unlock; | |
5286 | } | |
f45948e8 | 5287 | |
ac483c44 JO |
5288 | if (buf && !ftrace_match_records(hash, buf, len)) { |
5289 | ret = -EINVAL; | |
5290 | goto out_regex_unlock; | |
5291 | } | |
4f554e95 JO |
5292 | if (ips) { |
5293 | ret = ftrace_match_addr(hash, ips, cnt, remove); | |
647664ea MH |
5294 | if (ret < 0) |
5295 | goto out_regex_unlock; | |
5296 | } | |
33dc9b12 SR |
5297 | |
5298 | mutex_lock(&ftrace_lock); | |
e16b35dd | 5299 | ret = ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable); |
33dc9b12 SR |
5300 | mutex_unlock(&ftrace_lock); |
5301 | ||
ac483c44 | 5302 | out_regex_unlock: |
33b7f99c | 5303 | mutex_unlock(&ops->func_hash->regex_lock); |
33dc9b12 SR |
5304 | |
5305 | free_ftrace_hash(hash); | |
5306 | return ret; | |
41c52c0d SR |
5307 | } |
5308 | ||
647664ea | 5309 | static int |
4f554e95 JO |
5310 | ftrace_set_addr(struct ftrace_ops *ops, unsigned long *ips, unsigned int cnt, |
5311 | int remove, int reset, int enable) | |
647664ea | 5312 | { |
4f554e95 | 5313 | return ftrace_set_hash(ops, NULL, 0, ips, cnt, remove, reset, enable); |
647664ea MH |
5314 | } |
5315 | ||
763e34e7 | 5316 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS |
013bf0da SRV |
5317 | |
5318 | struct ftrace_direct_func { | |
5319 | struct list_head next; | |
5320 | unsigned long addr; | |
5321 | int count; | |
5322 | }; | |
5323 | ||
5324 | static LIST_HEAD(ftrace_direct_funcs); | |
5325 | ||
53cd885b SL |
5326 | static int register_ftrace_function_nolock(struct ftrace_ops *ops); |
5327 | ||
60c89718 | 5328 | #define MULTI_FLAGS (FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_ARGS) |
f64dd462 JO |
5329 | |
5330 | static int check_direct_multi(struct ftrace_ops *ops) | |
5331 | { | |
5332 | if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) | |
5333 | return -EINVAL; | |
5334 | if ((ops->flags & MULTI_FLAGS) != MULTI_FLAGS) | |
5335 | return -EINVAL; | |
5336 | return 0; | |
5337 | } | |
5338 | ||
5339 | static void remove_direct_functions_hash(struct ftrace_hash *hash, unsigned long addr) | |
5340 | { | |
5341 | struct ftrace_func_entry *entry, *del; | |
5342 | int size, i; | |
5343 | ||
5344 | size = 1 << hash->size_bits; | |
5345 | for (i = 0; i < size; i++) { | |
5346 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
5347 | del = __ftrace_lookup_ip(direct_functions, entry->ip); | |
5348 | if (del && del->direct == addr) { | |
5349 | remove_hash_entry(direct_functions, del); | |
5350 | kfree(del); | |
5351 | } | |
5352 | } | |
5353 | } | |
5354 | } | |
5355 | ||
5356 | /** | |
da8bdfbd | 5357 | * register_ftrace_direct - Call a custom trampoline directly |
f64dd462 JO |
5358 | * for multiple functions registered in @ops |
5359 | * @ops: The address of the struct ftrace_ops object | |
5360 | * @addr: The address of the trampoline to call at @ops functions | |
5361 | * | |
5362 | * This is used to connect a direct calls to @addr from the nop locations | |
5363 | * of the functions registered in @ops (with by ftrace_set_filter_ip | |
5364 | * function). | |
5365 | * | |
5366 | * The location that it calls (@addr) must be able to handle a direct call, | |
5367 | * and save the parameters of the function being traced, and restore them | |
5368 | * (or inject new ones if needed), before returning. | |
5369 | * | |
5370 | * Returns: | |
5371 | * 0 on success | |
5372 | * -EINVAL - The @ops object was already registered with this call or | |
5373 | * when there are no functions in @ops object. | |
5374 | * -EBUSY - Another direct function is already attached (there can be only one) | |
5375 | * -ENODEV - @ip does not point to a ftrace nop location (or not supported) | |
5376 | * -ENOMEM - There was an allocation failure. | |
5377 | */ | |
da8bdfbd | 5378 | int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr) |
f64dd462 JO |
5379 | { |
5380 | struct ftrace_hash *hash, *free_hash = NULL; | |
5381 | struct ftrace_func_entry *entry, *new; | |
5382 | int err = -EBUSY, size, i; | |
5383 | ||
5384 | if (ops->func || ops->trampoline) | |
5385 | return -EINVAL; | |
5386 | if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) | |
5387 | return -EINVAL; | |
5388 | if (ops->flags & FTRACE_OPS_FL_ENABLED) | |
5389 | return -EINVAL; | |
5390 | ||
5391 | hash = ops->func_hash->filter_hash; | |
5392 | if (ftrace_hash_empty(hash)) | |
5393 | return -EINVAL; | |
5394 | ||
5395 | mutex_lock(&direct_mutex); | |
5396 | ||
5397 | /* Make sure requested entries are not already registered.. */ | |
5398 | size = 1 << hash->size_bits; | |
5399 | for (i = 0; i < size; i++) { | |
5400 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
5401 | if (ftrace_find_rec_direct(entry->ip)) | |
5402 | goto out_unlock; | |
5403 | } | |
5404 | } | |
5405 | ||
5406 | /* ... and insert them to direct_functions hash. */ | |
5407 | err = -ENOMEM; | |
5408 | for (i = 0; i < size; i++) { | |
5409 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
5410 | new = ftrace_add_rec_direct(entry->ip, addr, &free_hash); | |
5411 | if (!new) | |
5412 | goto out_remove; | |
5413 | entry->direct = addr; | |
5414 | } | |
5415 | } | |
5416 | ||
5417 | ops->func = call_direct_funcs; | |
5418 | ops->flags = MULTI_FLAGS; | |
5419 | ops->trampoline = FTRACE_REGS_ADDR; | |
dbaccb61 | 5420 | ops->direct_call = addr; |
f64dd462 | 5421 | |
53cd885b | 5422 | err = register_ftrace_function_nolock(ops); |
f64dd462 JO |
5423 | |
5424 | out_remove: | |
5425 | if (err) | |
5426 | remove_direct_functions_hash(hash, addr); | |
5427 | ||
5428 | out_unlock: | |
5429 | mutex_unlock(&direct_mutex); | |
5430 | ||
5431 | if (free_hash) { | |
5432 | synchronize_rcu_tasks(); | |
5433 | free_ftrace_hash(free_hash); | |
5434 | } | |
5435 | return err; | |
5436 | } | |
da8bdfbd | 5437 | EXPORT_SYMBOL_GPL(register_ftrace_direct); |
f64dd462 JO |
5438 | |
5439 | /** | |
da8bdfbd FR |
5440 | * unregister_ftrace_direct - Remove calls to custom trampoline |
5441 | * previously registered by register_ftrace_direct for @ops object. | |
f64dd462 JO |
5442 | * @ops: The address of the struct ftrace_ops object |
5443 | * | |
5444 | * This is used to remove a direct calls to @addr from the nop locations | |
5445 | * of the functions registered in @ops (with by ftrace_set_filter_ip | |
5446 | * function). | |
5447 | * | |
5448 | * Returns: | |
5449 | * 0 on success | |
5450 | * -EINVAL - The @ops object was not properly registered. | |
5451 | */ | |
da8bdfbd FR |
5452 | int unregister_ftrace_direct(struct ftrace_ops *ops, unsigned long addr, |
5453 | bool free_filters) | |
f64dd462 JO |
5454 | { |
5455 | struct ftrace_hash *hash = ops->func_hash->filter_hash; | |
5456 | int err; | |
5457 | ||
5458 | if (check_direct_multi(ops)) | |
5459 | return -EINVAL; | |
5460 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
5461 | return -EINVAL; | |
5462 | ||
5463 | mutex_lock(&direct_mutex); | |
5464 | err = unregister_ftrace_function(ops); | |
5465 | remove_direct_functions_hash(hash, addr); | |
5466 | mutex_unlock(&direct_mutex); | |
fea3ffa4 JO |
5467 | |
5468 | /* cleanup for possible another register call */ | |
5469 | ops->func = NULL; | |
5470 | ops->trampoline = 0; | |
59495740 FR |
5471 | |
5472 | if (free_filters) | |
5473 | ftrace_free_filter(ops); | |
f64dd462 JO |
5474 | return err; |
5475 | } | |
da8bdfbd | 5476 | EXPORT_SYMBOL_GPL(unregister_ftrace_direct); |
ccf5a89e | 5477 | |
f96f644a | 5478 | static int |
da8bdfbd | 5479 | __modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr) |
ccf5a89e | 5480 | { |
ed292718 | 5481 | struct ftrace_hash *hash; |
ccf5a89e | 5482 | struct ftrace_func_entry *entry, *iter; |
ed292718 SRV |
5483 | static struct ftrace_ops tmp_ops = { |
5484 | .func = ftrace_stub, | |
5485 | .flags = FTRACE_OPS_FL_STUB, | |
5486 | }; | |
ccf5a89e JO |
5487 | int i, size; |
5488 | int err; | |
5489 | ||
f96f644a | 5490 | lockdep_assert_held_once(&direct_mutex); |
ed292718 SRV |
5491 | |
5492 | /* Enable the tmp_ops to have the same functions as the direct ops */ | |
5493 | ftrace_ops_init(&tmp_ops); | |
5494 | tmp_ops.func_hash = ops->func_hash; | |
dbaccb61 | 5495 | tmp_ops.direct_call = addr; |
ed292718 | 5496 | |
53cd885b | 5497 | err = register_ftrace_function_nolock(&tmp_ops); |
ed292718 | 5498 | if (err) |
f96f644a | 5499 | return err; |
ccf5a89e JO |
5500 | |
5501 | /* | |
ed292718 SRV |
5502 | * Now the ftrace_ops_list_func() is called to do the direct callers. |
5503 | * We can safely change the direct functions attached to each entry. | |
ccf5a89e | 5504 | */ |
ed292718 | 5505 | mutex_lock(&ftrace_lock); |
ccf5a89e | 5506 | |
ed292718 | 5507 | hash = ops->func_hash->filter_hash; |
ccf5a89e JO |
5508 | size = 1 << hash->size_bits; |
5509 | for (i = 0; i < size; i++) { | |
5510 | hlist_for_each_entry(iter, &hash->buckets[i], hlist) { | |
5511 | entry = __ftrace_lookup_ip(direct_functions, iter->ip); | |
5512 | if (!entry) | |
5513 | continue; | |
5514 | entry->direct = addr; | |
5515 | } | |
5516 | } | |
dbaccb61 FR |
5517 | /* Prevent store tearing if a trampoline concurrently accesses the value */ |
5518 | WRITE_ONCE(ops->direct_call, addr); | |
ccf5a89e | 5519 | |
2e6e9058 JO |
5520 | mutex_unlock(&ftrace_lock); |
5521 | ||
ed292718 SRV |
5522 | /* Removing the tmp_ops will add the updated direct callers to the functions */ |
5523 | unregister_ftrace_function(&tmp_ops); | |
ccf5a89e | 5524 | |
f96f644a SL |
5525 | return err; |
5526 | } | |
5527 | ||
5528 | /** | |
da8bdfbd | 5529 | * modify_ftrace_direct_nolock - Modify an existing direct 'multi' call |
f96f644a SL |
5530 | * to call something else |
5531 | * @ops: The address of the struct ftrace_ops object | |
5532 | * @addr: The address of the new trampoline to call at @ops functions | |
5533 | * | |
5534 | * This is used to unregister currently registered direct caller and | |
5535 | * register new one @addr on functions registered in @ops object. | |
5536 | * | |
5537 | * Note there's window between ftrace_shutdown and ftrace_startup calls | |
5538 | * where there will be no callbacks called. | |
5539 | * | |
5540 | * Caller should already have direct_mutex locked, so we don't lock | |
5541 | * direct_mutex here. | |
5542 | * | |
5543 | * Returns: zero on success. Non zero on error, which includes: | |
5544 | * -EINVAL - The @ops object was not properly registered. | |
5545 | */ | |
da8bdfbd | 5546 | int modify_ftrace_direct_nolock(struct ftrace_ops *ops, unsigned long addr) |
f96f644a SL |
5547 | { |
5548 | if (check_direct_multi(ops)) | |
5549 | return -EINVAL; | |
5550 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
5551 | return -EINVAL; | |
5552 | ||
da8bdfbd | 5553 | return __modify_ftrace_direct(ops, addr); |
f96f644a | 5554 | } |
da8bdfbd | 5555 | EXPORT_SYMBOL_GPL(modify_ftrace_direct_nolock); |
f96f644a SL |
5556 | |
5557 | /** | |
da8bdfbd | 5558 | * modify_ftrace_direct - Modify an existing direct 'multi' call |
f96f644a SL |
5559 | * to call something else |
5560 | * @ops: The address of the struct ftrace_ops object | |
5561 | * @addr: The address of the new trampoline to call at @ops functions | |
5562 | * | |
5563 | * This is used to unregister currently registered direct caller and | |
5564 | * register new one @addr on functions registered in @ops object. | |
5565 | * | |
5566 | * Note there's window between ftrace_shutdown and ftrace_startup calls | |
5567 | * where there will be no callbacks called. | |
5568 | * | |
5569 | * Returns: zero on success. Non zero on error, which includes: | |
5570 | * -EINVAL - The @ops object was not properly registered. | |
5571 | */ | |
da8bdfbd | 5572 | int modify_ftrace_direct(struct ftrace_ops *ops, unsigned long addr) |
f96f644a SL |
5573 | { |
5574 | int err; | |
5575 | ||
5576 | if (check_direct_multi(ops)) | |
5577 | return -EINVAL; | |
5578 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
5579 | return -EINVAL; | |
5580 | ||
5581 | mutex_lock(&direct_mutex); | |
da8bdfbd | 5582 | err = __modify_ftrace_direct(ops, addr); |
ccf5a89e JO |
5583 | mutex_unlock(&direct_mutex); |
5584 | return err; | |
5585 | } | |
da8bdfbd | 5586 | EXPORT_SYMBOL_GPL(modify_ftrace_direct); |
763e34e7 SRV |
5587 | #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ |
5588 | ||
647664ea MH |
5589 | /** |
5590 | * ftrace_set_filter_ip - set a function to filter on in ftrace by address | |
5591 | * @ops - the ops to set the filter with | |
5592 | * @ip - the address to add to or remove from the filter. | |
5593 | * @remove - non zero to remove the ip from the filter | |
5594 | * @reset - non zero to reset all filters before applying this filter. | |
5595 | * | |
5596 | * Filters denote which functions should be enabled when tracing is enabled | |
f2cc020d | 5597 | * If @ip is NULL, it fails to update filter. |
8be9fbd5 MR |
5598 | * |
5599 | * This can allocate memory which must be freed before @ops can be freed, | |
5600 | * either by removing each filtered addr or by using | |
5601 | * ftrace_free_filter(@ops). | |
647664ea MH |
5602 | */ |
5603 | int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, | |
5604 | int remove, int reset) | |
5605 | { | |
f04f24fb | 5606 | ftrace_ops_init(ops); |
4f554e95 | 5607 | return ftrace_set_addr(ops, &ip, 1, remove, reset, 1); |
647664ea MH |
5608 | } |
5609 | EXPORT_SYMBOL_GPL(ftrace_set_filter_ip); | |
5610 | ||
4f554e95 JO |
5611 | /** |
5612 | * ftrace_set_filter_ips - set functions to filter on in ftrace by addresses | |
5613 | * @ops - the ops to set the filter with | |
5614 | * @ips - the array of addresses to add to or remove from the filter. | |
5615 | * @cnt - the number of addresses in @ips | |
5616 | * @remove - non zero to remove ips from the filter | |
5617 | * @reset - non zero to reset all filters before applying this filter. | |
5618 | * | |
5619 | * Filters denote which functions should be enabled when tracing is enabled | |
5620 | * If @ips array or any ip specified within is NULL , it fails to update filter. | |
8be9fbd5 MR |
5621 | * |
5622 | * This can allocate memory which must be freed before @ops can be freed, | |
5623 | * either by removing each filtered addr or by using | |
5624 | * ftrace_free_filter(@ops). | |
5625 | */ | |
4f554e95 JO |
5626 | int ftrace_set_filter_ips(struct ftrace_ops *ops, unsigned long *ips, |
5627 | unsigned int cnt, int remove, int reset) | |
5628 | { | |
5629 | ftrace_ops_init(ops); | |
5630 | return ftrace_set_addr(ops, ips, cnt, remove, reset, 1); | |
5631 | } | |
5632 | EXPORT_SYMBOL_GPL(ftrace_set_filter_ips); | |
5633 | ||
d032ae89 JF |
5634 | /** |
5635 | * ftrace_ops_set_global_filter - setup ops to use global filters | |
5636 | * @ops - the ops which will use the global filters | |
5637 | * | |
5638 | * ftrace users who need global function trace filtering should call this. | |
5639 | * It can set the global filter only if ops were not initialized before. | |
5640 | */ | |
5641 | void ftrace_ops_set_global_filter(struct ftrace_ops *ops) | |
5642 | { | |
5643 | if (ops->flags & FTRACE_OPS_FL_INITIALIZED) | |
5644 | return; | |
5645 | ||
5646 | ftrace_ops_init(ops); | |
5647 | ops->func_hash = &global_ops.local_hash; | |
5648 | } | |
5649 | EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter); | |
5650 | ||
647664ea MH |
5651 | static int |
5652 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, | |
5653 | int reset, int enable) | |
5654 | { | |
4f554e95 | 5655 | return ftrace_set_hash(ops, buf, len, NULL, 0, 0, reset, enable); |
647664ea MH |
5656 | } |
5657 | ||
77a2b37d SR |
5658 | /** |
5659 | * ftrace_set_filter - set a function to filter on in ftrace | |
936e074b SR |
5660 | * @ops - the ops to set the filter with |
5661 | * @buf - the string that holds the function filter text. | |
5662 | * @len - the length of the string. | |
5663 | * @reset - non zero to reset all filters before applying this filter. | |
5664 | * | |
5665 | * Filters denote which functions should be enabled when tracing is enabled. | |
5666 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
8be9fbd5 MR |
5667 | * |
5668 | * This can allocate memory which must be freed before @ops can be freed, | |
5669 | * either by removing each filtered addr or by using | |
5670 | * ftrace_free_filter(@ops). | |
936e074b | 5671 | */ |
ac483c44 | 5672 | int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
5673 | int len, int reset) |
5674 | { | |
f04f24fb | 5675 | ftrace_ops_init(ops); |
ac483c44 | 5676 | return ftrace_set_regex(ops, buf, len, reset, 1); |
936e074b SR |
5677 | } |
5678 | EXPORT_SYMBOL_GPL(ftrace_set_filter); | |
5679 | ||
5680 | /** | |
5681 | * ftrace_set_notrace - set a function to not trace in ftrace | |
5682 | * @ops - the ops to set the notrace filter with | |
5683 | * @buf - the string that holds the function notrace text. | |
5684 | * @len - the length of the string. | |
5685 | * @reset - non zero to reset all filters before applying this filter. | |
5686 | * | |
5687 | * Notrace Filters denote which functions should not be enabled when tracing | |
5688 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
5689 | * for tracing. | |
8be9fbd5 MR |
5690 | * |
5691 | * This can allocate memory which must be freed before @ops can be freed, | |
5692 | * either by removing each filtered addr or by using | |
5693 | * ftrace_free_filter(@ops). | |
936e074b | 5694 | */ |
ac483c44 | 5695 | int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
5696 | int len, int reset) |
5697 | { | |
f04f24fb | 5698 | ftrace_ops_init(ops); |
ac483c44 | 5699 | return ftrace_set_regex(ops, buf, len, reset, 0); |
936e074b SR |
5700 | } |
5701 | EXPORT_SYMBOL_GPL(ftrace_set_notrace); | |
5702 | /** | |
8d1b065d | 5703 | * ftrace_set_global_filter - set a function to filter on with global tracers |
77a2b37d SR |
5704 | * @buf - the string that holds the function filter text. |
5705 | * @len - the length of the string. | |
5706 | * @reset - non zero to reset all filters before applying this filter. | |
5707 | * | |
5708 | * Filters denote which functions should be enabled when tracing is enabled. | |
5709 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
5710 | */ | |
936e074b | 5711 | void ftrace_set_global_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 5712 | { |
f45948e8 | 5713 | ftrace_set_regex(&global_ops, buf, len, reset, 1); |
41c52c0d | 5714 | } |
936e074b | 5715 | EXPORT_SYMBOL_GPL(ftrace_set_global_filter); |
4eebcc81 | 5716 | |
41c52c0d | 5717 | /** |
8d1b065d | 5718 | * ftrace_set_global_notrace - set a function to not trace with global tracers |
41c52c0d SR |
5719 | * @buf - the string that holds the function notrace text. |
5720 | * @len - the length of the string. | |
5721 | * @reset - non zero to reset all filters before applying this filter. | |
5722 | * | |
5723 | * Notrace Filters denote which functions should not be enabled when tracing | |
5724 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
5725 | * for tracing. | |
5726 | */ | |
936e074b | 5727 | void ftrace_set_global_notrace(unsigned char *buf, int len, int reset) |
41c52c0d | 5728 | { |
f45948e8 | 5729 | ftrace_set_regex(&global_ops, buf, len, reset, 0); |
77a2b37d | 5730 | } |
936e074b | 5731 | EXPORT_SYMBOL_GPL(ftrace_set_global_notrace); |
77a2b37d | 5732 | |
2af15d6a SR |
5733 | /* |
5734 | * command line interface to allow users to set filters on boot up. | |
5735 | */ | |
5736 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
5737 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
5738 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
5739 | ||
f1ed7c74 SRRH |
5740 | /* Used by function selftest to not test if filter is set */ |
5741 | bool ftrace_filter_param __initdata; | |
5742 | ||
2af15d6a SR |
5743 | static int __init set_ftrace_notrace(char *str) |
5744 | { | |
f1ed7c74 | 5745 | ftrace_filter_param = true; |
75761cc1 | 5746 | strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
5747 | return 1; |
5748 | } | |
5749 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
5750 | ||
5751 | static int __init set_ftrace_filter(char *str) | |
5752 | { | |
f1ed7c74 | 5753 | ftrace_filter_param = true; |
75761cc1 | 5754 | strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
5755 | return 1; |
5756 | } | |
5757 | __setup("ftrace_filter=", set_ftrace_filter); | |
5758 | ||
369bc18f | 5759 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 5760 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
0d7d9a16 | 5761 | static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata; |
b9b0c831 | 5762 | static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer); |
801c29fd | 5763 | |
369bc18f SA |
5764 | static int __init set_graph_function(char *str) |
5765 | { | |
06f43d66 | 5766 | strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
5767 | return 1; |
5768 | } | |
5769 | __setup("ftrace_graph_filter=", set_graph_function); | |
5770 | ||
0d7d9a16 NK |
5771 | static int __init set_graph_notrace_function(char *str) |
5772 | { | |
5773 | strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE); | |
5774 | return 1; | |
5775 | } | |
5776 | __setup("ftrace_graph_notrace=", set_graph_notrace_function); | |
5777 | ||
65a50c65 TB |
5778 | static int __init set_graph_max_depth_function(char *str) |
5779 | { | |
5780 | if (!str) | |
5781 | return 0; | |
5782 | fgraph_max_depth = simple_strtoul(str, NULL, 0); | |
5783 | return 1; | |
5784 | } | |
5785 | __setup("ftrace_graph_max_depth=", set_graph_max_depth_function); | |
0d7d9a16 NK |
5786 | |
5787 | static void __init set_ftrace_early_graph(char *buf, int enable) | |
369bc18f SA |
5788 | { |
5789 | int ret; | |
5790 | char *func; | |
b9b0c831 | 5791 | struct ftrace_hash *hash; |
0d7d9a16 | 5792 | |
92ad18ec | 5793 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); |
24589e3a | 5794 | if (MEM_FAIL(!hash, "Failed to allocate hash\n")) |
92ad18ec | 5795 | return; |
369bc18f SA |
5796 | |
5797 | while (buf) { | |
5798 | func = strsep(&buf, ","); | |
5799 | /* we allow only one expression at a time */ | |
b9b0c831 | 5800 | ret = ftrace_graph_set_hash(hash, func); |
369bc18f SA |
5801 | if (ret) |
5802 | printk(KERN_DEBUG "ftrace: function %s not " | |
5803 | "traceable\n", func); | |
5804 | } | |
92ad18ec SRV |
5805 | |
5806 | if (enable) | |
5807 | ftrace_graph_hash = hash; | |
5808 | else | |
5809 | ftrace_graph_notrace_hash = hash; | |
369bc18f SA |
5810 | } |
5811 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
5812 | ||
2a85a37f SR |
5813 | void __init |
5814 | ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable) | |
2af15d6a SR |
5815 | { |
5816 | char *func; | |
5817 | ||
f04f24fb MH |
5818 | ftrace_ops_init(ops); |
5819 | ||
2af15d6a SR |
5820 | while (buf) { |
5821 | func = strsep(&buf, ","); | |
f45948e8 | 5822 | ftrace_set_regex(ops, func, strlen(func), 0, enable); |
2af15d6a SR |
5823 | } |
5824 | } | |
5825 | ||
5826 | static void __init set_ftrace_early_filters(void) | |
5827 | { | |
5828 | if (ftrace_filter_buf[0]) | |
2a85a37f | 5829 | ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1); |
2af15d6a | 5830 | if (ftrace_notrace_buf[0]) |
2a85a37f | 5831 | ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0); |
369bc18f SA |
5832 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5833 | if (ftrace_graph_buf[0]) | |
0d7d9a16 NK |
5834 | set_ftrace_early_graph(ftrace_graph_buf, 1); |
5835 | if (ftrace_graph_notrace_buf[0]) | |
5836 | set_ftrace_early_graph(ftrace_graph_notrace_buf, 0); | |
369bc18f | 5837 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
2af15d6a SR |
5838 | } |
5839 | ||
fc13cb0c | 5840 | int ftrace_regex_release(struct inode *inode, struct file *file) |
5072c59f SR |
5841 | { |
5842 | struct seq_file *m = (struct seq_file *)file->private_data; | |
5843 | struct ftrace_iterator *iter; | |
33dc9b12 | 5844 | struct ftrace_hash **orig_hash; |
689fd8b6 | 5845 | struct trace_parser *parser; |
ed926f9b | 5846 | int filter_hash; |
5072c59f | 5847 | |
5072c59f SR |
5848 | if (file->f_mode & FMODE_READ) { |
5849 | iter = m->private; | |
5072c59f SR |
5850 | seq_release(inode, file); |
5851 | } else | |
5852 | iter = file->private_data; | |
5853 | ||
689fd8b6 | 5854 | parser = &iter->parser; |
5855 | if (trace_parser_loaded(parser)) { | |
8c9af478 SRV |
5856 | int enable = !(iter->flags & FTRACE_ITER_NOTRACE); |
5857 | ||
5858 | ftrace_process_regex(iter, parser->buffer, | |
5859 | parser->idx, enable); | |
5072c59f SR |
5860 | } |
5861 | ||
689fd8b6 | 5862 | trace_parser_put(parser); |
689fd8b6 | 5863 | |
33b7f99c | 5864 | mutex_lock(&iter->ops->func_hash->regex_lock); |
3f2367ba | 5865 | |
058e297d | 5866 | if (file->f_mode & FMODE_WRITE) { |
ed926f9b SR |
5867 | filter_hash = !!(iter->flags & FTRACE_ITER_FILTER); |
5868 | ||
8c08f0d5 | 5869 | if (filter_hash) { |
33b7f99c | 5870 | orig_hash = &iter->ops->func_hash->filter_hash; |
0ce0638e ZY |
5871 | if (iter->tr) { |
5872 | if (list_empty(&iter->tr->mod_trace)) | |
5873 | iter->hash->flags &= ~FTRACE_HASH_FL_MOD; | |
5874 | else | |
5875 | iter->hash->flags |= FTRACE_HASH_FL_MOD; | |
5876 | } | |
8c08f0d5 | 5877 | } else |
33b7f99c | 5878 | orig_hash = &iter->ops->func_hash->notrace_hash; |
33dc9b12 | 5879 | |
058e297d | 5880 | mutex_lock(&ftrace_lock); |
045e269c | 5881 | ftrace_hash_move_and_update_ops(iter->ops, orig_hash, |
e16b35dd | 5882 | iter->hash, filter_hash); |
058e297d | 5883 | mutex_unlock(&ftrace_lock); |
c20489da SRV |
5884 | } else { |
5885 | /* For read only, the hash is the ops hash */ | |
5886 | iter->hash = NULL; | |
058e297d | 5887 | } |
3f2367ba | 5888 | |
33b7f99c | 5889 | mutex_unlock(&iter->ops->func_hash->regex_lock); |
33dc9b12 | 5890 | free_ftrace_hash(iter->hash); |
9ef16693 SRV |
5891 | if (iter->tr) |
5892 | trace_array_put(iter->tr); | |
33dc9b12 | 5893 | kfree(iter); |
058e297d | 5894 | |
5072c59f SR |
5895 | return 0; |
5896 | } | |
5897 | ||
5e2336a0 | 5898 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
5899 | .open = ftrace_avail_open, |
5900 | .read = seq_read, | |
5901 | .llseek = seq_lseek, | |
3be04b47 | 5902 | .release = seq_release_private, |
5072c59f SR |
5903 | }; |
5904 | ||
647bcd03 SR |
5905 | static const struct file_operations ftrace_enabled_fops = { |
5906 | .open = ftrace_enabled_open, | |
5907 | .read = seq_read, | |
5908 | .llseek = seq_lseek, | |
5909 | .release = seq_release_private, | |
5910 | }; | |
5911 | ||
e11b521a SRG |
5912 | static const struct file_operations ftrace_touched_fops = { |
5913 | .open = ftrace_touched_open, | |
5914 | .read = seq_read, | |
5915 | .llseek = seq_lseek, | |
5916 | .release = seq_release_private, | |
5917 | }; | |
5918 | ||
5e2336a0 | 5919 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 5920 | .open = ftrace_filter_open, |
850a80cf | 5921 | .read = seq_read, |
5072c59f | 5922 | .write = ftrace_filter_write, |
098c879e | 5923 | .llseek = tracing_lseek, |
1cf41dd7 | 5924 | .release = ftrace_regex_release, |
5072c59f SR |
5925 | }; |
5926 | ||
5e2336a0 | 5927 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 5928 | .open = ftrace_notrace_open, |
850a80cf | 5929 | .read = seq_read, |
41c52c0d | 5930 | .write = ftrace_notrace_write, |
098c879e | 5931 | .llseek = tracing_lseek, |
1cf41dd7 | 5932 | .release = ftrace_regex_release, |
41c52c0d SR |
5933 | }; |
5934 | ||
ea4e2bc4 SR |
5935 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5936 | ||
5937 | static DEFINE_MUTEX(graph_lock); | |
5938 | ||
24a9729f | 5939 | struct ftrace_hash __rcu *ftrace_graph_hash = EMPTY_HASH; |
fd0e6852 | 5940 | struct ftrace_hash __rcu *ftrace_graph_notrace_hash = EMPTY_HASH; |
b9b0c831 NK |
5941 | |
5942 | enum graph_filter_type { | |
5943 | GRAPH_FILTER_NOTRACE = 0, | |
5944 | GRAPH_FILTER_FUNCTION, | |
5945 | }; | |
ea4e2bc4 | 5946 | |
555fc781 SRV |
5947 | #define FTRACE_GRAPH_EMPTY ((void *)1) |
5948 | ||
faf982a6 | 5949 | struct ftrace_graph_data { |
e704eff3 SRV |
5950 | struct ftrace_hash *hash; |
5951 | struct ftrace_func_entry *entry; | |
5952 | int idx; /* for hash table iteration */ | |
5953 | enum graph_filter_type type; | |
5954 | struct ftrace_hash *new_hash; | |
5955 | const struct seq_operations *seq_ops; | |
5956 | struct trace_parser parser; | |
faf982a6 NK |
5957 | }; |
5958 | ||
ea4e2bc4 | 5959 | static void * |
85951842 | 5960 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 5961 | { |
faf982a6 | 5962 | struct ftrace_graph_data *fgd = m->private; |
b9b0c831 NK |
5963 | struct ftrace_func_entry *entry = fgd->entry; |
5964 | struct hlist_head *head; | |
5965 | int i, idx = fgd->idx; | |
faf982a6 | 5966 | |
b9b0c831 | 5967 | if (*pos >= fgd->hash->count) |
ea4e2bc4 | 5968 | return NULL; |
b9b0c831 NK |
5969 | |
5970 | if (entry) { | |
5971 | hlist_for_each_entry_continue(entry, hlist) { | |
5972 | fgd->entry = entry; | |
5973 | return entry; | |
5974 | } | |
5975 | ||
5976 | idx++; | |
5977 | } | |
5978 | ||
5979 | for (i = idx; i < 1 << fgd->hash->size_bits; i++) { | |
5980 | head = &fgd->hash->buckets[i]; | |
5981 | hlist_for_each_entry(entry, head, hlist) { | |
5982 | fgd->entry = entry; | |
5983 | fgd->idx = i; | |
5984 | return entry; | |
5985 | } | |
5986 | } | |
5987 | return NULL; | |
85951842 | 5988 | } |
ea4e2bc4 | 5989 | |
85951842 LZ |
5990 | static void * |
5991 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
5992 | { | |
5993 | (*pos)++; | |
5994 | return __g_next(m, pos); | |
ea4e2bc4 SR |
5995 | } |
5996 | ||
5997 | static void *g_start(struct seq_file *m, loff_t *pos) | |
5998 | { | |
faf982a6 NK |
5999 | struct ftrace_graph_data *fgd = m->private; |
6000 | ||
ea4e2bc4 SR |
6001 | mutex_lock(&graph_lock); |
6002 | ||
649b988b SRV |
6003 | if (fgd->type == GRAPH_FILTER_FUNCTION) |
6004 | fgd->hash = rcu_dereference_protected(ftrace_graph_hash, | |
6005 | lockdep_is_held(&graph_lock)); | |
6006 | else | |
6007 | fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash, | |
6008 | lockdep_is_held(&graph_lock)); | |
6009 | ||
f9349a8f | 6010 | /* Nothing, tell g_show to print all functions are enabled */ |
b9b0c831 | 6011 | if (ftrace_hash_empty(fgd->hash) && !*pos) |
555fc781 | 6012 | return FTRACE_GRAPH_EMPTY; |
f9349a8f | 6013 | |
b9b0c831 NK |
6014 | fgd->idx = 0; |
6015 | fgd->entry = NULL; | |
85951842 | 6016 | return __g_next(m, pos); |
ea4e2bc4 SR |
6017 | } |
6018 | ||
6019 | static void g_stop(struct seq_file *m, void *p) | |
6020 | { | |
6021 | mutex_unlock(&graph_lock); | |
6022 | } | |
6023 | ||
6024 | static int g_show(struct seq_file *m, void *v) | |
6025 | { | |
b9b0c831 | 6026 | struct ftrace_func_entry *entry = v; |
ea4e2bc4 | 6027 | |
b9b0c831 | 6028 | if (!entry) |
ea4e2bc4 SR |
6029 | return 0; |
6030 | ||
555fc781 | 6031 | if (entry == FTRACE_GRAPH_EMPTY) { |
280d1429 NK |
6032 | struct ftrace_graph_data *fgd = m->private; |
6033 | ||
b9b0c831 | 6034 | if (fgd->type == GRAPH_FILTER_FUNCTION) |
fa6f0cc7 | 6035 | seq_puts(m, "#### all functions enabled ####\n"); |
280d1429 | 6036 | else |
fa6f0cc7 | 6037 | seq_puts(m, "#### no functions disabled ####\n"); |
f9349a8f FW |
6038 | return 0; |
6039 | } | |
6040 | ||
b9b0c831 | 6041 | seq_printf(m, "%ps\n", (void *)entry->ip); |
ea4e2bc4 SR |
6042 | |
6043 | return 0; | |
6044 | } | |
6045 | ||
88e9d34c | 6046 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
6047 | .start = g_start, |
6048 | .next = g_next, | |
6049 | .stop = g_stop, | |
6050 | .show = g_show, | |
6051 | }; | |
6052 | ||
6053 | static int | |
faf982a6 NK |
6054 | __ftrace_graph_open(struct inode *inode, struct file *file, |
6055 | struct ftrace_graph_data *fgd) | |
ea4e2bc4 | 6056 | { |
17911ff3 | 6057 | int ret; |
b9b0c831 | 6058 | struct ftrace_hash *new_hash = NULL; |
ea4e2bc4 | 6059 | |
17911ff3 SRV |
6060 | ret = security_locked_down(LOCKDOWN_TRACEFS); |
6061 | if (ret) | |
6062 | return ret; | |
6063 | ||
b9b0c831 NK |
6064 | if (file->f_mode & FMODE_WRITE) { |
6065 | const int size_bits = FTRACE_HASH_DEFAULT_BITS; | |
6066 | ||
e704eff3 SRV |
6067 | if (trace_parser_get_init(&fgd->parser, FTRACE_BUFF_MAX)) |
6068 | return -ENOMEM; | |
6069 | ||
b9b0c831 NK |
6070 | if (file->f_flags & O_TRUNC) |
6071 | new_hash = alloc_ftrace_hash(size_bits); | |
6072 | else | |
6073 | new_hash = alloc_and_copy_ftrace_hash(size_bits, | |
6074 | fgd->hash); | |
6075 | if (!new_hash) { | |
6076 | ret = -ENOMEM; | |
6077 | goto out; | |
6078 | } | |
ea4e2bc4 SR |
6079 | } |
6080 | ||
faf982a6 | 6081 | if (file->f_mode & FMODE_READ) { |
b9b0c831 | 6082 | ret = seq_open(file, &ftrace_graph_seq_ops); |
faf982a6 NK |
6083 | if (!ret) { |
6084 | struct seq_file *m = file->private_data; | |
6085 | m->private = fgd; | |
b9b0c831 NK |
6086 | } else { |
6087 | /* Failed */ | |
6088 | free_ftrace_hash(new_hash); | |
6089 | new_hash = NULL; | |
faf982a6 NK |
6090 | } |
6091 | } else | |
6092 | file->private_data = fgd; | |
ea4e2bc4 | 6093 | |
b9b0c831 | 6094 | out: |
e704eff3 SRV |
6095 | if (ret < 0 && file->f_mode & FMODE_WRITE) |
6096 | trace_parser_put(&fgd->parser); | |
6097 | ||
b9b0c831 | 6098 | fgd->new_hash = new_hash; |
649b988b SRV |
6099 | |
6100 | /* | |
6101 | * All uses of fgd->hash must be taken with the graph_lock | |
6102 | * held. The graph_lock is going to be released, so force | |
6103 | * fgd->hash to be reinitialized when it is taken again. | |
6104 | */ | |
6105 | fgd->hash = NULL; | |
6106 | ||
ea4e2bc4 SR |
6107 | return ret; |
6108 | } | |
6109 | ||
faf982a6 NK |
6110 | static int |
6111 | ftrace_graph_open(struct inode *inode, struct file *file) | |
6112 | { | |
6113 | struct ftrace_graph_data *fgd; | |
b9b0c831 | 6114 | int ret; |
faf982a6 NK |
6115 | |
6116 | if (unlikely(ftrace_disabled)) | |
6117 | return -ENODEV; | |
6118 | ||
6119 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
6120 | if (fgd == NULL) | |
6121 | return -ENOMEM; | |
6122 | ||
b9b0c831 NK |
6123 | mutex_lock(&graph_lock); |
6124 | ||
649b988b SRV |
6125 | fgd->hash = rcu_dereference_protected(ftrace_graph_hash, |
6126 | lockdep_is_held(&graph_lock)); | |
b9b0c831 | 6127 | fgd->type = GRAPH_FILTER_FUNCTION; |
faf982a6 NK |
6128 | fgd->seq_ops = &ftrace_graph_seq_ops; |
6129 | ||
b9b0c831 NK |
6130 | ret = __ftrace_graph_open(inode, file, fgd); |
6131 | if (ret < 0) | |
6132 | kfree(fgd); | |
6133 | ||
6134 | mutex_unlock(&graph_lock); | |
6135 | return ret; | |
faf982a6 NK |
6136 | } |
6137 | ||
29ad23b0 NK |
6138 | static int |
6139 | ftrace_graph_notrace_open(struct inode *inode, struct file *file) | |
6140 | { | |
6141 | struct ftrace_graph_data *fgd; | |
b9b0c831 | 6142 | int ret; |
29ad23b0 NK |
6143 | |
6144 | if (unlikely(ftrace_disabled)) | |
6145 | return -ENODEV; | |
6146 | ||
6147 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
6148 | if (fgd == NULL) | |
6149 | return -ENOMEM; | |
6150 | ||
b9b0c831 NK |
6151 | mutex_lock(&graph_lock); |
6152 | ||
649b988b SRV |
6153 | fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash, |
6154 | lockdep_is_held(&graph_lock)); | |
b9b0c831 | 6155 | fgd->type = GRAPH_FILTER_NOTRACE; |
29ad23b0 NK |
6156 | fgd->seq_ops = &ftrace_graph_seq_ops; |
6157 | ||
b9b0c831 NK |
6158 | ret = __ftrace_graph_open(inode, file, fgd); |
6159 | if (ret < 0) | |
6160 | kfree(fgd); | |
6161 | ||
6162 | mutex_unlock(&graph_lock); | |
6163 | return ret; | |
29ad23b0 NK |
6164 | } |
6165 | ||
87827111 LZ |
6166 | static int |
6167 | ftrace_graph_release(struct inode *inode, struct file *file) | |
6168 | { | |
b9b0c831 | 6169 | struct ftrace_graph_data *fgd; |
e704eff3 SRV |
6170 | struct ftrace_hash *old_hash, *new_hash; |
6171 | struct trace_parser *parser; | |
6172 | int ret = 0; | |
b9b0c831 | 6173 | |
faf982a6 NK |
6174 | if (file->f_mode & FMODE_READ) { |
6175 | struct seq_file *m = file->private_data; | |
6176 | ||
b9b0c831 | 6177 | fgd = m->private; |
87827111 | 6178 | seq_release(inode, file); |
faf982a6 | 6179 | } else { |
b9b0c831 | 6180 | fgd = file->private_data; |
faf982a6 NK |
6181 | } |
6182 | ||
e704eff3 SRV |
6183 | |
6184 | if (file->f_mode & FMODE_WRITE) { | |
6185 | ||
6186 | parser = &fgd->parser; | |
6187 | ||
6188 | if (trace_parser_loaded((parser))) { | |
e704eff3 SRV |
6189 | ret = ftrace_graph_set_hash(fgd->new_hash, |
6190 | parser->buffer); | |
6191 | } | |
6192 | ||
6193 | trace_parser_put(parser); | |
6194 | ||
6195 | new_hash = __ftrace_hash_move(fgd->new_hash); | |
6196 | if (!new_hash) { | |
6197 | ret = -ENOMEM; | |
6198 | goto out; | |
6199 | } | |
6200 | ||
6201 | mutex_lock(&graph_lock); | |
6202 | ||
6203 | if (fgd->type == GRAPH_FILTER_FUNCTION) { | |
6204 | old_hash = rcu_dereference_protected(ftrace_graph_hash, | |
6205 | lockdep_is_held(&graph_lock)); | |
6206 | rcu_assign_pointer(ftrace_graph_hash, new_hash); | |
6207 | } else { | |
6208 | old_hash = rcu_dereference_protected(ftrace_graph_notrace_hash, | |
6209 | lockdep_is_held(&graph_lock)); | |
6210 | rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash); | |
6211 | } | |
6212 | ||
6213 | mutex_unlock(&graph_lock); | |
6214 | ||
54a16ff6 SRV |
6215 | /* |
6216 | * We need to do a hard force of sched synchronization. | |
6217 | * This is because we use preempt_disable() to do RCU, but | |
6218 | * the function tracers can be called where RCU is not watching | |
6219 | * (like before user_exit()). We can not rely on the RCU | |
6220 | * infrastructure to do the synchronization, thus we must do it | |
6221 | * ourselves. | |
6222 | */ | |
68e83498 NSJ |
6223 | if (old_hash != EMPTY_HASH) |
6224 | synchronize_rcu_tasks_rude(); | |
e704eff3 SRV |
6225 | |
6226 | free_ftrace_hash(old_hash); | |
6227 | } | |
6228 | ||
6229 | out: | |
f9797c2f | 6230 | free_ftrace_hash(fgd->new_hash); |
b9b0c831 NK |
6231 | kfree(fgd); |
6232 | ||
e704eff3 | 6233 | return ret; |
87827111 LZ |
6234 | } |
6235 | ||
ea4e2bc4 | 6236 | static int |
b9b0c831 | 6237 | ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer) |
ea4e2bc4 | 6238 | { |
3ba00929 | 6239 | struct ftrace_glob func_g; |
ea4e2bc4 SR |
6240 | struct dyn_ftrace *rec; |
6241 | struct ftrace_page *pg; | |
b9b0c831 | 6242 | struct ftrace_func_entry *entry; |
c7c6b1fe | 6243 | int fail = 1; |
3ba00929 | 6244 | int not; |
ea4e2bc4 | 6245 | |
f9349a8f | 6246 | /* decode regex */ |
3ba00929 DS |
6247 | func_g.type = filter_parse_regex(buffer, strlen(buffer), |
6248 | &func_g.search, ¬); | |
f9349a8f | 6249 | |
3ba00929 | 6250 | func_g.len = strlen(func_g.search); |
f9349a8f | 6251 | |
52baf119 | 6252 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
6253 | |
6254 | if (unlikely(ftrace_disabled)) { | |
6255 | mutex_unlock(&ftrace_lock); | |
6256 | return -ENODEV; | |
6257 | } | |
6258 | ||
265c831c SR |
6259 | do_for_each_ftrace_rec(pg, rec) { |
6260 | ||
546fece4 SRRH |
6261 | if (rec->flags & FTRACE_FL_DISABLED) |
6262 | continue; | |
6263 | ||
0b507e1e | 6264 | if (ftrace_match_record(rec, &func_g, NULL, 0)) { |
b9b0c831 | 6265 | entry = ftrace_lookup_ip(hash, rec->ip); |
c7c6b1fe LZ |
6266 | |
6267 | if (!not) { | |
6268 | fail = 0; | |
b9b0c831 NK |
6269 | |
6270 | if (entry) | |
6271 | continue; | |
6272 | if (add_hash_entry(hash, rec->ip) < 0) | |
6273 | goto out; | |
c7c6b1fe | 6274 | } else { |
b9b0c831 NK |
6275 | if (entry) { |
6276 | free_hash_entry(hash, entry); | |
c7c6b1fe LZ |
6277 | fail = 0; |
6278 | } | |
6279 | } | |
ea4e2bc4 | 6280 | } |
265c831c | 6281 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 6282 | out: |
52baf119 | 6283 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 6284 | |
c7c6b1fe LZ |
6285 | if (fail) |
6286 | return -EINVAL; | |
6287 | ||
c7c6b1fe | 6288 | return 0; |
ea4e2bc4 SR |
6289 | } |
6290 | ||
6291 | static ssize_t | |
6292 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
6293 | size_t cnt, loff_t *ppos) | |
6294 | { | |
6a10108b | 6295 | ssize_t read, ret = 0; |
faf982a6 | 6296 | struct ftrace_graph_data *fgd = file->private_data; |
e704eff3 | 6297 | struct trace_parser *parser; |
ea4e2bc4 | 6298 | |
c7c6b1fe | 6299 | if (!cnt) |
ea4e2bc4 SR |
6300 | return 0; |
6301 | ||
ae98d27a SRV |
6302 | /* Read mode uses seq functions */ |
6303 | if (file->f_mode & FMODE_READ) { | |
6304 | struct seq_file *m = file->private_data; | |
6305 | fgd = m->private; | |
6306 | } | |
6307 | ||
e704eff3 | 6308 | parser = &fgd->parser; |
ea4e2bc4 | 6309 | |
e704eff3 | 6310 | read = trace_get_user(parser, ubuf, cnt, ppos); |
689fd8b6 | 6311 | |
e704eff3 SRV |
6312 | if (read >= 0 && trace_parser_loaded(parser) && |
6313 | !trace_parser_cont(parser)) { | |
6a10108b | 6314 | |
b9b0c831 | 6315 | ret = ftrace_graph_set_hash(fgd->new_hash, |
e704eff3 SRV |
6316 | parser->buffer); |
6317 | trace_parser_clear(parser); | |
ea4e2bc4 | 6318 | } |
ea4e2bc4 | 6319 | |
6a10108b NK |
6320 | if (!ret) |
6321 | ret = read; | |
1eb90f13 | 6322 | |
ea4e2bc4 SR |
6323 | return ret; |
6324 | } | |
6325 | ||
6326 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
6327 | .open = ftrace_graph_open, |
6328 | .read = seq_read, | |
6329 | .write = ftrace_graph_write, | |
098c879e | 6330 | .llseek = tracing_lseek, |
87827111 | 6331 | .release = ftrace_graph_release, |
ea4e2bc4 | 6332 | }; |
29ad23b0 NK |
6333 | |
6334 | static const struct file_operations ftrace_graph_notrace_fops = { | |
6335 | .open = ftrace_graph_notrace_open, | |
6336 | .read = seq_read, | |
6337 | .write = ftrace_graph_write, | |
098c879e | 6338 | .llseek = tracing_lseek, |
29ad23b0 NK |
6339 | .release = ftrace_graph_release, |
6340 | }; | |
ea4e2bc4 SR |
6341 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
6342 | ||
591dffda SRRH |
6343 | void ftrace_create_filter_files(struct ftrace_ops *ops, |
6344 | struct dentry *parent) | |
6345 | { | |
6346 | ||
21ccc9cd | 6347 | trace_create_file("set_ftrace_filter", TRACE_MODE_WRITE, parent, |
591dffda SRRH |
6348 | ops, &ftrace_filter_fops); |
6349 | ||
21ccc9cd | 6350 | trace_create_file("set_ftrace_notrace", TRACE_MODE_WRITE, parent, |
591dffda SRRH |
6351 | ops, &ftrace_notrace_fops); |
6352 | } | |
6353 | ||
6354 | /* | |
6355 | * The name "destroy_filter_files" is really a misnomer. Although | |
9efb85c5 | 6356 | * in the future, it may actually delete the files, but this is |
591dffda SRRH |
6357 | * really intended to make sure the ops passed in are disabled |
6358 | * and that when this function returns, the caller is free to | |
6359 | * free the ops. | |
6360 | * | |
6361 | * The "destroy" name is only to match the "create" name that this | |
6362 | * should be paired with. | |
6363 | */ | |
6364 | void ftrace_destroy_filter_files(struct ftrace_ops *ops) | |
6365 | { | |
6366 | mutex_lock(&ftrace_lock); | |
6367 | if (ops->flags & FTRACE_OPS_FL_ENABLED) | |
6368 | ftrace_shutdown(ops, 0); | |
6369 | ops->flags |= FTRACE_OPS_FL_DELETED; | |
2840f84f | 6370 | ftrace_free_filter(ops); |
591dffda SRRH |
6371 | mutex_unlock(&ftrace_lock); |
6372 | } | |
6373 | ||
8434dc93 | 6374 | static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer) |
5072c59f | 6375 | { |
5072c59f | 6376 | |
21ccc9cd | 6377 | trace_create_file("available_filter_functions", TRACE_MODE_READ, |
5452af66 | 6378 | d_tracer, NULL, &ftrace_avail_fops); |
5072c59f | 6379 | |
21ccc9cd | 6380 | trace_create_file("enabled_functions", TRACE_MODE_READ, |
647bcd03 SR |
6381 | d_tracer, NULL, &ftrace_enabled_fops); |
6382 | ||
e11b521a SRG |
6383 | trace_create_file("touched_functions", TRACE_MODE_READ, |
6384 | d_tracer, NULL, &ftrace_touched_fops); | |
6385 | ||
591dffda | 6386 | ftrace_create_filter_files(&global_ops, d_tracer); |
ad90c0e3 | 6387 | |
ea4e2bc4 | 6388 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
21ccc9cd | 6389 | trace_create_file("set_graph_function", TRACE_MODE_WRITE, d_tracer, |
ea4e2bc4 SR |
6390 | NULL, |
6391 | &ftrace_graph_fops); | |
21ccc9cd | 6392 | trace_create_file("set_graph_notrace", TRACE_MODE_WRITE, d_tracer, |
29ad23b0 NK |
6393 | NULL, |
6394 | &ftrace_graph_notrace_fops); | |
ea4e2bc4 SR |
6395 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
6396 | ||
5072c59f SR |
6397 | return 0; |
6398 | } | |
6399 | ||
9fd49328 | 6400 | static int ftrace_cmp_ips(const void *a, const void *b) |
68950619 | 6401 | { |
9fd49328 SR |
6402 | const unsigned long *ipa = a; |
6403 | const unsigned long *ipb = b; | |
68950619 | 6404 | |
9fd49328 SR |
6405 | if (*ipa > *ipb) |
6406 | return 1; | |
6407 | if (*ipa < *ipb) | |
6408 | return -1; | |
6409 | return 0; | |
6410 | } | |
6411 | ||
8147dc78 SRV |
6412 | #ifdef CONFIG_FTRACE_SORT_STARTUP_TEST |
6413 | static void test_is_sorted(unsigned long *start, unsigned long count) | |
6414 | { | |
6415 | int i; | |
6416 | ||
6417 | for (i = 1; i < count; i++) { | |
6418 | if (WARN(start[i - 1] > start[i], | |
6419 | "[%d] %pS at %lx is not sorted with %pS at %lx\n", i, | |
6420 | (void *)start[i - 1], start[i - 1], | |
6421 | (void *)start[i], start[i])) | |
6422 | break; | |
6423 | } | |
6424 | if (i == count) | |
6425 | pr_info("ftrace section at %px sorted properly\n", start); | |
6426 | } | |
6427 | #else | |
6428 | static void test_is_sorted(unsigned long *start, unsigned long count) | |
6429 | { | |
6430 | } | |
6431 | #endif | |
6432 | ||
5cb084bb | 6433 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 6434 | unsigned long *start, |
68bf21aa SR |
6435 | unsigned long *end) |
6436 | { | |
706c81f8 | 6437 | struct ftrace_page *start_pg; |
a7900875 | 6438 | struct ftrace_page *pg; |
706c81f8 | 6439 | struct dyn_ftrace *rec; |
a7900875 | 6440 | unsigned long count; |
68bf21aa SR |
6441 | unsigned long *p; |
6442 | unsigned long addr; | |
4376cac6 | 6443 | unsigned long flags = 0; /* Shut up gcc */ |
a7900875 SR |
6444 | int ret = -ENOMEM; |
6445 | ||
6446 | count = end - start; | |
6447 | ||
6448 | if (!count) | |
6449 | return 0; | |
6450 | ||
72b3942a YL |
6451 | /* |
6452 | * Sorting mcount in vmlinux at build time depend on | |
6b9b6413 | 6453 | * CONFIG_BUILDTIME_MCOUNT_SORT, while mcount loc in |
72b3942a YL |
6454 | * modules can not be sorted at build time. |
6455 | */ | |
6b9b6413 | 6456 | if (!IS_ENABLED(CONFIG_BUILDTIME_MCOUNT_SORT) || mod) { |
72b3942a YL |
6457 | sort(start, count, sizeof(*start), |
6458 | ftrace_cmp_ips, NULL); | |
8147dc78 SRV |
6459 | } else { |
6460 | test_is_sorted(start, count); | |
72b3942a | 6461 | } |
9fd49328 | 6462 | |
706c81f8 SR |
6463 | start_pg = ftrace_allocate_pages(count); |
6464 | if (!start_pg) | |
a7900875 | 6465 | return -ENOMEM; |
68bf21aa | 6466 | |
e6ea44e9 | 6467 | mutex_lock(&ftrace_lock); |
a7900875 | 6468 | |
32082309 SR |
6469 | /* |
6470 | * Core and each module needs their own pages, as | |
6471 | * modules will free them when they are removed. | |
6472 | * Force a new page to be allocated for modules. | |
6473 | */ | |
a7900875 SR |
6474 | if (!mod) { |
6475 | WARN_ON(ftrace_pages || ftrace_pages_start); | |
6476 | /* First initialization */ | |
706c81f8 | 6477 | ftrace_pages = ftrace_pages_start = start_pg; |
a7900875 | 6478 | } else { |
32082309 | 6479 | if (!ftrace_pages) |
a7900875 | 6480 | goto out; |
32082309 | 6481 | |
a7900875 SR |
6482 | if (WARN_ON(ftrace_pages->next)) { |
6483 | /* Hmm, we have free pages? */ | |
6484 | while (ftrace_pages->next) | |
6485 | ftrace_pages = ftrace_pages->next; | |
32082309 | 6486 | } |
a7900875 | 6487 | |
706c81f8 | 6488 | ftrace_pages->next = start_pg; |
32082309 SR |
6489 | } |
6490 | ||
68bf21aa | 6491 | p = start; |
706c81f8 | 6492 | pg = start_pg; |
68bf21aa | 6493 | while (p < end) { |
db42523b | 6494 | unsigned long end_offset; |
68bf21aa | 6495 | addr = ftrace_call_adjust(*p++); |
20e5227e SR |
6496 | /* |
6497 | * Some architecture linkers will pad between | |
6498 | * the different mcount_loc sections of different | |
6499 | * object files to satisfy alignments. | |
6500 | * Skip any NULL pointers. | |
6501 | */ | |
6502 | if (!addr) | |
6503 | continue; | |
706c81f8 | 6504 | |
db42523b LT |
6505 | end_offset = (pg->index+1) * sizeof(pg->records[0]); |
6506 | if (end_offset > PAGE_SIZE << pg->order) { | |
706c81f8 SR |
6507 | /* We should have allocated enough */ |
6508 | if (WARN_ON(!pg->next)) | |
6509 | break; | |
6510 | pg = pg->next; | |
6511 | } | |
6512 | ||
6513 | rec = &pg->records[pg->index++]; | |
6514 | rec->ip = addr; | |
68bf21aa SR |
6515 | } |
6516 | ||
706c81f8 SR |
6517 | /* We should have used all pages */ |
6518 | WARN_ON(pg->next); | |
6519 | ||
6520 | /* Assign the last page to ftrace_pages */ | |
6521 | ftrace_pages = pg; | |
6522 | ||
a4f18ed1 | 6523 | /* |
4376cac6 SR |
6524 | * We only need to disable interrupts on start up |
6525 | * because we are modifying code that an interrupt | |
6526 | * may execute, and the modification is not atomic. | |
6527 | * But for modules, nothing runs the code we modify | |
6528 | * until we are finished with it, and there's no | |
6529 | * reason to cause large interrupt latencies while we do it. | |
a4f18ed1 | 6530 | */ |
4376cac6 SR |
6531 | if (!mod) |
6532 | local_irq_save(flags); | |
1dc43cf0 | 6533 | ftrace_update_code(mod, start_pg); |
4376cac6 SR |
6534 | if (!mod) |
6535 | local_irq_restore(flags); | |
a7900875 SR |
6536 | ret = 0; |
6537 | out: | |
e6ea44e9 | 6538 | mutex_unlock(&ftrace_lock); |
68bf21aa | 6539 | |
a7900875 | 6540 | return ret; |
68bf21aa SR |
6541 | } |
6542 | ||
aba4b5c2 SRV |
6543 | struct ftrace_mod_func { |
6544 | struct list_head list; | |
6545 | char *name; | |
6546 | unsigned long ip; | |
6547 | unsigned int size; | |
6548 | }; | |
6549 | ||
6550 | struct ftrace_mod_map { | |
6aa69784 | 6551 | struct rcu_head rcu; |
aba4b5c2 SRV |
6552 | struct list_head list; |
6553 | struct module *mod; | |
6554 | unsigned long start_addr; | |
6555 | unsigned long end_addr; | |
6556 | struct list_head funcs; | |
6171a031 | 6557 | unsigned int num_funcs; |
aba4b5c2 SRV |
6558 | }; |
6559 | ||
fc0ea795 AH |
6560 | static int ftrace_get_trampoline_kallsym(unsigned int symnum, |
6561 | unsigned long *value, char *type, | |
6562 | char *name, char *module_name, | |
6563 | int *exported) | |
6564 | { | |
6565 | struct ftrace_ops *op; | |
6566 | ||
6567 | list_for_each_entry_rcu(op, &ftrace_ops_trampoline_list, list) { | |
6568 | if (!op->trampoline || symnum--) | |
6569 | continue; | |
6570 | *value = op->trampoline; | |
6571 | *type = 't'; | |
6572 | strlcpy(name, FTRACE_TRAMPOLINE_SYM, KSYM_NAME_LEN); | |
6573 | strlcpy(module_name, FTRACE_TRAMPOLINE_MOD, MODULE_NAME_LEN); | |
6574 | *exported = 0; | |
6575 | return 0; | |
6576 | } | |
6577 | ||
6578 | return -ERANGE; | |
6579 | } | |
6580 | ||
123d6455 WJ |
6581 | #if defined(CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS) || defined(CONFIG_MODULES) |
6582 | /* | |
6583 | * Check if the current ops references the given ip. | |
6584 | * | |
6585 | * If the ops traces all functions, then it was already accounted for. | |
6586 | * If the ops does not trace the current record function, skip it. | |
6587 | * If the ops ignores the function via notrace filter, skip it. | |
6588 | */ | |
6589 | static bool | |
6590 | ops_references_ip(struct ftrace_ops *ops, unsigned long ip) | |
6591 | { | |
6592 | /* If ops isn't enabled, ignore it */ | |
6593 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
6594 | return false; | |
6595 | ||
6596 | /* If ops traces all then it includes this function */ | |
6597 | if (ops_traces_mod(ops)) | |
6598 | return true; | |
6599 | ||
6600 | /* The function must be in the filter */ | |
6601 | if (!ftrace_hash_empty(ops->func_hash->filter_hash) && | |
6602 | !__ftrace_lookup_ip(ops->func_hash->filter_hash, ip)) | |
6603 | return false; | |
6604 | ||
6605 | /* If in notrace hash, we ignore it too */ | |
6606 | if (ftrace_lookup_ip(ops->func_hash->notrace_hash, ip)) | |
6607 | return false; | |
6608 | ||
6609 | return true; | |
6610 | } | |
6611 | #endif | |
6612 | ||
93eb677d | 6613 | #ifdef CONFIG_MODULES |
32082309 SR |
6614 | |
6615 | #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next) | |
6616 | ||
6aa69784 SRV |
6617 | static LIST_HEAD(ftrace_mod_maps); |
6618 | ||
b7ffffbb SRRH |
6619 | static int referenced_filters(struct dyn_ftrace *rec) |
6620 | { | |
6621 | struct ftrace_ops *ops; | |
6622 | int cnt = 0; | |
6623 | ||
6624 | for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) { | |
123d6455 | 6625 | if (ops_references_ip(ops, rec->ip)) { |
c5f51572 CZ |
6626 | if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_DIRECT)) |
6627 | continue; | |
6628 | if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_IPMODIFY)) | |
6629 | continue; | |
8a224ffb CZ |
6630 | cnt++; |
6631 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) | |
6632 | rec->flags |= FTRACE_FL_REGS; | |
c5f51572 CZ |
6633 | if (cnt == 1 && ops->trampoline) |
6634 | rec->flags |= FTRACE_FL_TRAMP; | |
6635 | else | |
6636 | rec->flags &= ~FTRACE_FL_TRAMP; | |
8a224ffb | 6637 | } |
b7ffffbb SRRH |
6638 | } |
6639 | ||
6640 | return cnt; | |
6641 | } | |
6642 | ||
2a5bfe47 SRV |
6643 | static void |
6644 | clear_mod_from_hash(struct ftrace_page *pg, struct ftrace_hash *hash) | |
6645 | { | |
6646 | struct ftrace_func_entry *entry; | |
6647 | struct dyn_ftrace *rec; | |
6648 | int i; | |
6649 | ||
6650 | if (ftrace_hash_empty(hash)) | |
6651 | return; | |
6652 | ||
6653 | for (i = 0; i < pg->index; i++) { | |
6654 | rec = &pg->records[i]; | |
6655 | entry = __ftrace_lookup_ip(hash, rec->ip); | |
6656 | /* | |
6657 | * Do not allow this rec to match again. | |
6658 | * Yeah, it may waste some memory, but will be removed | |
6659 | * if/when the hash is modified again. | |
6660 | */ | |
6661 | if (entry) | |
6662 | entry->ip = 0; | |
6663 | } | |
6664 | } | |
6665 | ||
f2cc020d | 6666 | /* Clear any records from hashes */ |
2a5bfe47 SRV |
6667 | static void clear_mod_from_hashes(struct ftrace_page *pg) |
6668 | { | |
6669 | struct trace_array *tr; | |
6670 | ||
6671 | mutex_lock(&trace_types_lock); | |
6672 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
6673 | if (!tr->ops || !tr->ops->func_hash) | |
6674 | continue; | |
6675 | mutex_lock(&tr->ops->func_hash->regex_lock); | |
6676 | clear_mod_from_hash(pg, tr->ops->func_hash->filter_hash); | |
6677 | clear_mod_from_hash(pg, tr->ops->func_hash->notrace_hash); | |
6678 | mutex_unlock(&tr->ops->func_hash->regex_lock); | |
6679 | } | |
6680 | mutex_unlock(&trace_types_lock); | |
6681 | } | |
6682 | ||
6aa69784 SRV |
6683 | static void ftrace_free_mod_map(struct rcu_head *rcu) |
6684 | { | |
6685 | struct ftrace_mod_map *mod_map = container_of(rcu, struct ftrace_mod_map, rcu); | |
6686 | struct ftrace_mod_func *mod_func; | |
6687 | struct ftrace_mod_func *n; | |
6688 | ||
6689 | /* All the contents of mod_map are now not visible to readers */ | |
6690 | list_for_each_entry_safe(mod_func, n, &mod_map->funcs, list) { | |
6691 | kfree(mod_func->name); | |
6692 | list_del(&mod_func->list); | |
6693 | kfree(mod_func); | |
6694 | } | |
6695 | ||
6696 | kfree(mod_map); | |
6697 | } | |
6698 | ||
e7247a15 | 6699 | void ftrace_release_mod(struct module *mod) |
93eb677d | 6700 | { |
6aa69784 SRV |
6701 | struct ftrace_mod_map *mod_map; |
6702 | struct ftrace_mod_map *n; | |
93eb677d | 6703 | struct dyn_ftrace *rec; |
32082309 | 6704 | struct ftrace_page **last_pg; |
2a5bfe47 | 6705 | struct ftrace_page *tmp_page = NULL; |
93eb677d | 6706 | struct ftrace_page *pg; |
93eb677d | 6707 | |
45a4a237 SR |
6708 | mutex_lock(&ftrace_lock); |
6709 | ||
e7247a15 | 6710 | if (ftrace_disabled) |
45a4a237 | 6711 | goto out_unlock; |
93eb677d | 6712 | |
6aa69784 SRV |
6713 | list_for_each_entry_safe(mod_map, n, &ftrace_mod_maps, list) { |
6714 | if (mod_map->mod == mod) { | |
6715 | list_del_rcu(&mod_map->list); | |
74401729 | 6716 | call_rcu(&mod_map->rcu, ftrace_free_mod_map); |
6aa69784 SRV |
6717 | break; |
6718 | } | |
6719 | } | |
6720 | ||
32082309 SR |
6721 | /* |
6722 | * Each module has its own ftrace_pages, remove | |
6723 | * them from the list. | |
6724 | */ | |
6725 | last_pg = &ftrace_pages_start; | |
6726 | for (pg = ftrace_pages_start; pg; pg = *last_pg) { | |
6727 | rec = &pg->records[0]; | |
3e234289 SRV |
6728 | if (within_module_core(rec->ip, mod) || |
6729 | within_module_init(rec->ip, mod)) { | |
93eb677d | 6730 | /* |
32082309 SR |
6731 | * As core pages are first, the first |
6732 | * page should never be a module page. | |
93eb677d | 6733 | */ |
32082309 SR |
6734 | if (WARN_ON(pg == ftrace_pages_start)) |
6735 | goto out_unlock; | |
6736 | ||
6737 | /* Check if we are deleting the last page */ | |
6738 | if (pg == ftrace_pages) | |
6739 | ftrace_pages = next_to_ftrace_page(last_pg); | |
6740 | ||
83dd1493 | 6741 | ftrace_update_tot_cnt -= pg->index; |
32082309 | 6742 | *last_pg = pg->next; |
2a5bfe47 SRV |
6743 | |
6744 | pg->next = tmp_page; | |
6745 | tmp_page = pg; | |
32082309 SR |
6746 | } else |
6747 | last_pg = &pg->next; | |
6748 | } | |
45a4a237 | 6749 | out_unlock: |
93eb677d | 6750 | mutex_unlock(&ftrace_lock); |
2a5bfe47 SRV |
6751 | |
6752 | for (pg = tmp_page; pg; pg = tmp_page) { | |
6753 | ||
6754 | /* Needs to be called outside of ftrace_lock */ | |
6755 | clear_mod_from_hashes(pg); | |
6756 | ||
db42523b LT |
6757 | if (pg->records) { |
6758 | free_pages((unsigned long)pg->records, pg->order); | |
6759 | ftrace_number_of_pages -= 1 << pg->order; | |
6760 | } | |
2a5bfe47 SRV |
6761 | tmp_page = pg->next; |
6762 | kfree(pg); | |
da537f0a | 6763 | ftrace_number_of_groups--; |
2a5bfe47 | 6764 | } |
93eb677d SR |
6765 | } |
6766 | ||
7dcd182b | 6767 | void ftrace_module_enable(struct module *mod) |
b7ffffbb SRRH |
6768 | { |
6769 | struct dyn_ftrace *rec; | |
6770 | struct ftrace_page *pg; | |
6771 | ||
6772 | mutex_lock(&ftrace_lock); | |
6773 | ||
6774 | if (ftrace_disabled) | |
6775 | goto out_unlock; | |
6776 | ||
6777 | /* | |
6778 | * If the tracing is enabled, go ahead and enable the record. | |
6779 | * | |
9efb85c5 | 6780 | * The reason not to enable the record immediately is the |
b7ffffbb SRRH |
6781 | * inherent check of ftrace_make_nop/ftrace_make_call for |
6782 | * correct previous instructions. Making first the NOP | |
6783 | * conversion puts the module to the correct state, thus | |
6784 | * passing the ftrace_make_call check. | |
6785 | * | |
6786 | * We also delay this to after the module code already set the | |
6787 | * text to read-only, as we now need to set it back to read-write | |
6788 | * so that we can modify the text. | |
6789 | */ | |
6790 | if (ftrace_start_up) | |
6791 | ftrace_arch_code_modify_prepare(); | |
6792 | ||
6793 | do_for_each_ftrace_rec(pg, rec) { | |
6794 | int cnt; | |
6795 | /* | |
6796 | * do_for_each_ftrace_rec() is a double loop. | |
6797 | * module text shares the pg. If a record is | |
6798 | * not part of this module, then skip this pg, | |
6799 | * which the "break" will do. | |
6800 | */ | |
3e234289 SRV |
6801 | if (!within_module_core(rec->ip, mod) && |
6802 | !within_module_init(rec->ip, mod)) | |
b7ffffbb SRRH |
6803 | break; |
6804 | ||
b39181f7 SRG |
6805 | /* Weak functions should still be ignored */ |
6806 | if (!test_for_valid_rec(rec)) { | |
6807 | /* Clear all other flags. Should not be enabled anyway */ | |
6808 | rec->flags = FTRACE_FL_DISABLED; | |
6809 | continue; | |
6810 | } | |
6811 | ||
b7ffffbb SRRH |
6812 | cnt = 0; |
6813 | ||
6814 | /* | |
6815 | * When adding a module, we need to check if tracers are | |
6816 | * currently enabled and if they are, and can trace this record, | |
6817 | * we need to enable the module functions as well as update the | |
6818 | * reference counts for those function records. | |
6819 | */ | |
6820 | if (ftrace_start_up) | |
6821 | cnt += referenced_filters(rec); | |
6822 | ||
8a224ffb CZ |
6823 | rec->flags &= ~FTRACE_FL_DISABLED; |
6824 | rec->flags += cnt; | |
b7ffffbb SRRH |
6825 | |
6826 | if (ftrace_start_up && cnt) { | |
6827 | int failed = __ftrace_replace_code(rec, 1); | |
6828 | if (failed) { | |
6829 | ftrace_bug(failed, rec); | |
6830 | goto out_loop; | |
6831 | } | |
6832 | } | |
6833 | ||
6834 | } while_for_each_ftrace_rec(); | |
6835 | ||
6836 | out_loop: | |
6837 | if (ftrace_start_up) | |
6838 | ftrace_arch_code_modify_post_process(); | |
6839 | ||
6840 | out_unlock: | |
6841 | mutex_unlock(&ftrace_lock); | |
d7fbf8df SRV |
6842 | |
6843 | process_cached_mods(mod->name); | |
b7ffffbb SRRH |
6844 | } |
6845 | ||
b6b71f66 | 6846 | void ftrace_module_init(struct module *mod) |
90d595fe | 6847 | { |
2889c658 YW |
6848 | int ret; |
6849 | ||
97e9b4fc | 6850 | if (ftrace_disabled || !mod->num_ftrace_callsites) |
fed1939c | 6851 | return; |
90d595fe | 6852 | |
2889c658 YW |
6853 | ret = ftrace_process_locs(mod, mod->ftrace_callsites, |
6854 | mod->ftrace_callsites + mod->num_ftrace_callsites); | |
6855 | if (ret) | |
6856 | pr_warn("ftrace: failed to allocate entries for module '%s' functions\n", | |
6857 | mod->name); | |
8c189ea6 | 6858 | } |
aba4b5c2 SRV |
6859 | |
6860 | static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map, | |
6861 | struct dyn_ftrace *rec) | |
6862 | { | |
6863 | struct ftrace_mod_func *mod_func; | |
6864 | unsigned long symsize; | |
6865 | unsigned long offset; | |
6866 | char str[KSYM_SYMBOL_LEN]; | |
6867 | char *modname; | |
6868 | const char *ret; | |
6869 | ||
6870 | ret = kallsyms_lookup(rec->ip, &symsize, &offset, &modname, str); | |
6871 | if (!ret) | |
6872 | return; | |
6873 | ||
6874 | mod_func = kmalloc(sizeof(*mod_func), GFP_KERNEL); | |
6875 | if (!mod_func) | |
6876 | return; | |
6877 | ||
6878 | mod_func->name = kstrdup(str, GFP_KERNEL); | |
6879 | if (!mod_func->name) { | |
6880 | kfree(mod_func); | |
6881 | return; | |
6882 | } | |
6883 | ||
6884 | mod_func->ip = rec->ip - offset; | |
6885 | mod_func->size = symsize; | |
6886 | ||
6171a031 SRV |
6887 | mod_map->num_funcs++; |
6888 | ||
aba4b5c2 SRV |
6889 | list_add_rcu(&mod_func->list, &mod_map->funcs); |
6890 | } | |
6891 | ||
aba4b5c2 SRV |
6892 | static struct ftrace_mod_map * |
6893 | allocate_ftrace_mod_map(struct module *mod, | |
6894 | unsigned long start, unsigned long end) | |
6895 | { | |
6896 | struct ftrace_mod_map *mod_map; | |
6897 | ||
6898 | mod_map = kmalloc(sizeof(*mod_map), GFP_KERNEL); | |
6899 | if (!mod_map) | |
6900 | return NULL; | |
6901 | ||
6902 | mod_map->mod = mod; | |
6903 | mod_map->start_addr = start; | |
6904 | mod_map->end_addr = end; | |
6171a031 | 6905 | mod_map->num_funcs = 0; |
aba4b5c2 SRV |
6906 | |
6907 | INIT_LIST_HEAD_RCU(&mod_map->funcs); | |
6908 | ||
6909 | list_add_rcu(&mod_map->list, &ftrace_mod_maps); | |
6910 | ||
6911 | return mod_map; | |
6912 | } | |
6913 | ||
6914 | static const char * | |
6915 | ftrace_func_address_lookup(struct ftrace_mod_map *mod_map, | |
6916 | unsigned long addr, unsigned long *size, | |
6917 | unsigned long *off, char *sym) | |
6918 | { | |
6919 | struct ftrace_mod_func *found_func = NULL; | |
6920 | struct ftrace_mod_func *mod_func; | |
6921 | ||
6922 | list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) { | |
6923 | if (addr >= mod_func->ip && | |
6924 | addr < mod_func->ip + mod_func->size) { | |
6925 | found_func = mod_func; | |
6926 | break; | |
6927 | } | |
6928 | } | |
6929 | ||
6930 | if (found_func) { | |
6931 | if (size) | |
6932 | *size = found_func->size; | |
6933 | if (off) | |
6934 | *off = addr - found_func->ip; | |
6935 | if (sym) | |
6936 | strlcpy(sym, found_func->name, KSYM_NAME_LEN); | |
6937 | ||
6938 | return found_func->name; | |
6939 | } | |
6940 | ||
6941 | return NULL; | |
6942 | } | |
6943 | ||
6944 | const char * | |
6945 | ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, | |
6946 | unsigned long *off, char **modname, char *sym) | |
6947 | { | |
6948 | struct ftrace_mod_map *mod_map; | |
6949 | const char *ret = NULL; | |
6950 | ||
74401729 | 6951 | /* mod_map is freed via call_rcu() */ |
aba4b5c2 SRV |
6952 | preempt_disable(); |
6953 | list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) { | |
6954 | ret = ftrace_func_address_lookup(mod_map, addr, size, off, sym); | |
6955 | if (ret) { | |
6956 | if (modname) | |
6957 | *modname = mod_map->mod->name; | |
6958 | break; | |
6959 | } | |
6960 | } | |
6961 | preempt_enable(); | |
6962 | ||
6963 | return ret; | |
6964 | } | |
6965 | ||
6171a031 SRV |
6966 | int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, |
6967 | char *type, char *name, | |
6968 | char *module_name, int *exported) | |
6969 | { | |
6970 | struct ftrace_mod_map *mod_map; | |
6971 | struct ftrace_mod_func *mod_func; | |
fc0ea795 | 6972 | int ret; |
6171a031 SRV |
6973 | |
6974 | preempt_disable(); | |
6975 | list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) { | |
6976 | ||
6977 | if (symnum >= mod_map->num_funcs) { | |
6978 | symnum -= mod_map->num_funcs; | |
6979 | continue; | |
6980 | } | |
6981 | ||
6982 | list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) { | |
6983 | if (symnum > 1) { | |
6984 | symnum--; | |
6985 | continue; | |
6986 | } | |
6987 | ||
6988 | *value = mod_func->ip; | |
6989 | *type = 'T'; | |
6990 | strlcpy(name, mod_func->name, KSYM_NAME_LEN); | |
6991 | strlcpy(module_name, mod_map->mod->name, MODULE_NAME_LEN); | |
6992 | *exported = 1; | |
6993 | preempt_enable(); | |
6994 | return 0; | |
6995 | } | |
6996 | WARN_ON(1); | |
6997 | break; | |
6998 | } | |
fc0ea795 AH |
6999 | ret = ftrace_get_trampoline_kallsym(symnum, value, type, name, |
7000 | module_name, exported); | |
6171a031 | 7001 | preempt_enable(); |
fc0ea795 | 7002 | return ret; |
6171a031 SRV |
7003 | } |
7004 | ||
aba4b5c2 SRV |
7005 | #else |
7006 | static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map, | |
7007 | struct dyn_ftrace *rec) { } | |
7008 | static inline struct ftrace_mod_map * | |
7009 | allocate_ftrace_mod_map(struct module *mod, | |
7010 | unsigned long start, unsigned long end) | |
7011 | { | |
7012 | return NULL; | |
7013 | } | |
fc0ea795 AH |
7014 | int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, |
7015 | char *type, char *name, char *module_name, | |
7016 | int *exported) | |
7017 | { | |
7018 | int ret; | |
7019 | ||
7020 | preempt_disable(); | |
7021 | ret = ftrace_get_trampoline_kallsym(symnum, value, type, name, | |
7022 | module_name, exported); | |
7023 | preempt_enable(); | |
7024 | return ret; | |
7025 | } | |
93eb677d SR |
7026 | #endif /* CONFIG_MODULES */ |
7027 | ||
8715b108 JF |
7028 | struct ftrace_init_func { |
7029 | struct list_head list; | |
7030 | unsigned long ip; | |
7031 | }; | |
7032 | ||
7033 | /* Clear any init ips from hashes */ | |
7034 | static void | |
7035 | clear_func_from_hash(struct ftrace_init_func *func, struct ftrace_hash *hash) | |
42c269c8 | 7036 | { |
8715b108 JF |
7037 | struct ftrace_func_entry *entry; |
7038 | ||
08468754 | 7039 | entry = ftrace_lookup_ip(hash, func->ip); |
8715b108 JF |
7040 | /* |
7041 | * Do not allow this rec to match again. | |
7042 | * Yeah, it may waste some memory, but will be removed | |
7043 | * if/when the hash is modified again. | |
7044 | */ | |
7045 | if (entry) | |
7046 | entry->ip = 0; | |
7047 | } | |
7048 | ||
7049 | static void | |
7050 | clear_func_from_hashes(struct ftrace_init_func *func) | |
7051 | { | |
7052 | struct trace_array *tr; | |
7053 | ||
7054 | mutex_lock(&trace_types_lock); | |
7055 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
7056 | if (!tr->ops || !tr->ops->func_hash) | |
7057 | continue; | |
7058 | mutex_lock(&tr->ops->func_hash->regex_lock); | |
7059 | clear_func_from_hash(func, tr->ops->func_hash->filter_hash); | |
7060 | clear_func_from_hash(func, tr->ops->func_hash->notrace_hash); | |
7061 | mutex_unlock(&tr->ops->func_hash->regex_lock); | |
7062 | } | |
7063 | mutex_unlock(&trace_types_lock); | |
7064 | } | |
7065 | ||
7066 | static void add_to_clear_hash_list(struct list_head *clear_list, | |
7067 | struct dyn_ftrace *rec) | |
7068 | { | |
7069 | struct ftrace_init_func *func; | |
7070 | ||
7071 | func = kmalloc(sizeof(*func), GFP_KERNEL); | |
7072 | if (!func) { | |
24589e3a | 7073 | MEM_FAIL(1, "alloc failure, ftrace filter could be stale\n"); |
8715b108 JF |
7074 | return; |
7075 | } | |
7076 | ||
7077 | func->ip = rec->ip; | |
7078 | list_add(&func->list, clear_list); | |
7079 | } | |
7080 | ||
aba4b5c2 | 7081 | void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr) |
42c269c8 | 7082 | { |
6cafbe15 SRV |
7083 | unsigned long start = (unsigned long)(start_ptr); |
7084 | unsigned long end = (unsigned long)(end_ptr); | |
42c269c8 SRV |
7085 | struct ftrace_page **last_pg = &ftrace_pages_start; |
7086 | struct ftrace_page *pg; | |
7087 | struct dyn_ftrace *rec; | |
7088 | struct dyn_ftrace key; | |
aba4b5c2 | 7089 | struct ftrace_mod_map *mod_map = NULL; |
8715b108 JF |
7090 | struct ftrace_init_func *func, *func_next; |
7091 | struct list_head clear_hash; | |
42c269c8 | 7092 | |
8715b108 JF |
7093 | INIT_LIST_HEAD(&clear_hash); |
7094 | ||
42c269c8 SRV |
7095 | key.ip = start; |
7096 | key.flags = end; /* overload flags, as it is unsigned long */ | |
7097 | ||
7098 | mutex_lock(&ftrace_lock); | |
7099 | ||
aba4b5c2 SRV |
7100 | /* |
7101 | * If we are freeing module init memory, then check if | |
7102 | * any tracer is active. If so, we need to save a mapping of | |
7103 | * the module functions being freed with the address. | |
7104 | */ | |
7105 | if (mod && ftrace_ops_list != &ftrace_list_end) | |
7106 | mod_map = allocate_ftrace_mod_map(mod, start, end); | |
7107 | ||
42c269c8 SRV |
7108 | for (pg = ftrace_pages_start; pg; last_pg = &pg->next, pg = *last_pg) { |
7109 | if (end < pg->records[0].ip || | |
7110 | start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) | |
7111 | continue; | |
7112 | again: | |
7113 | rec = bsearch(&key, pg->records, pg->index, | |
7114 | sizeof(struct dyn_ftrace), | |
7115 | ftrace_cmp_recs); | |
7116 | if (!rec) | |
7117 | continue; | |
aba4b5c2 | 7118 | |
8715b108 JF |
7119 | /* rec will be cleared from hashes after ftrace_lock unlock */ |
7120 | add_to_clear_hash_list(&clear_hash, rec); | |
7121 | ||
aba4b5c2 SRV |
7122 | if (mod_map) |
7123 | save_ftrace_mod_rec(mod_map, rec); | |
7124 | ||
42c269c8 | 7125 | pg->index--; |
4ec78467 | 7126 | ftrace_update_tot_cnt--; |
42c269c8 SRV |
7127 | if (!pg->index) { |
7128 | *last_pg = pg->next; | |
db42523b LT |
7129 | if (pg->records) { |
7130 | free_pages((unsigned long)pg->records, pg->order); | |
7131 | ftrace_number_of_pages -= 1 << pg->order; | |
7132 | } | |
da537f0a | 7133 | ftrace_number_of_groups--; |
42c269c8 SRV |
7134 | kfree(pg); |
7135 | pg = container_of(last_pg, struct ftrace_page, next); | |
7136 | if (!(*last_pg)) | |
7137 | ftrace_pages = pg; | |
7138 | continue; | |
7139 | } | |
7140 | memmove(rec, rec + 1, | |
7141 | (pg->index - (rec - pg->records)) * sizeof(*rec)); | |
7142 | /* More than one function may be in this block */ | |
7143 | goto again; | |
7144 | } | |
7145 | mutex_unlock(&ftrace_lock); | |
8715b108 JF |
7146 | |
7147 | list_for_each_entry_safe(func, func_next, &clear_hash, list) { | |
7148 | clear_func_from_hashes(func); | |
7149 | kfree(func); | |
7150 | } | |
42c269c8 SRV |
7151 | } |
7152 | ||
6cafbe15 SRV |
7153 | void __init ftrace_free_init_mem(void) |
7154 | { | |
7155 | void *start = (void *)(&__init_begin); | |
7156 | void *end = (void *)(&__init_end); | |
7157 | ||
380af29b SRG |
7158 | ftrace_boot_snapshot(); |
7159 | ||
aba4b5c2 | 7160 | ftrace_free_mem(NULL, start, end); |
42c269c8 SRV |
7161 | } |
7162 | ||
6644c654 WO |
7163 | int __init __weak ftrace_dyn_arch_init(void) |
7164 | { | |
7165 | return 0; | |
7166 | } | |
7167 | ||
68bf21aa SR |
7168 | void __init ftrace_init(void) |
7169 | { | |
1dc43cf0 JS |
7170 | extern unsigned long __start_mcount_loc[]; |
7171 | extern unsigned long __stop_mcount_loc[]; | |
3a36cb11 | 7172 | unsigned long count, flags; |
68bf21aa SR |
7173 | int ret; |
7174 | ||
68bf21aa | 7175 | local_irq_save(flags); |
3a36cb11 | 7176 | ret = ftrace_dyn_arch_init(); |
68bf21aa | 7177 | local_irq_restore(flags); |
af64a7cb | 7178 | if (ret) |
68bf21aa SR |
7179 | goto failed; |
7180 | ||
7181 | count = __stop_mcount_loc - __start_mcount_loc; | |
c867ccd8 JS |
7182 | if (!count) { |
7183 | pr_info("ftrace: No functions to be traced?\n"); | |
68bf21aa | 7184 | goto failed; |
c867ccd8 JS |
7185 | } |
7186 | ||
7187 | pr_info("ftrace: allocating %ld entries in %ld pages\n", | |
08948cae | 7188 | count, DIV_ROUND_UP(count, ENTRIES_PER_PAGE)); |
68bf21aa | 7189 | |
5cb084bb | 7190 | ret = ftrace_process_locs(NULL, |
31e88909 | 7191 | __start_mcount_loc, |
68bf21aa | 7192 | __stop_mcount_loc); |
2889c658 YW |
7193 | if (ret) { |
7194 | pr_warn("ftrace: failed to allocate entries for functions\n"); | |
7195 | goto failed; | |
7196 | } | |
68bf21aa | 7197 | |
da537f0a SRV |
7198 | pr_info("ftrace: allocated %ld pages with %ld groups\n", |
7199 | ftrace_number_of_pages, ftrace_number_of_groups); | |
7200 | ||
2889c658 YW |
7201 | last_ftrace_enabled = ftrace_enabled = 1; |
7202 | ||
2af15d6a SR |
7203 | set_ftrace_early_filters(); |
7204 | ||
68bf21aa SR |
7205 | return; |
7206 | failed: | |
7207 | ftrace_disabled = 1; | |
7208 | } | |
68bf21aa | 7209 | |
f3bea491 SRRH |
7210 | /* Do nothing if arch does not support this */ |
7211 | void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops) | |
7212 | { | |
7213 | } | |
7214 | ||
7215 | static void ftrace_update_trampoline(struct ftrace_ops *ops) | |
7216 | { | |
fc0ea795 AH |
7217 | unsigned long trampoline = ops->trampoline; |
7218 | ||
f3bea491 | 7219 | arch_ftrace_update_trampoline(ops); |
fc0ea795 | 7220 | if (ops->trampoline && ops->trampoline != trampoline && |
dd9ddf46 AH |
7221 | (ops->flags & FTRACE_OPS_FL_ALLOC_TRAMP)) { |
7222 | /* Add to kallsyms before the perf events */ | |
fc0ea795 | 7223 | ftrace_add_trampoline_to_kallsyms(ops); |
dd9ddf46 AH |
7224 | perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL, |
7225 | ops->trampoline, ops->trampoline_size, false, | |
7226 | FTRACE_TRAMPOLINE_SYM); | |
548e1f6c AH |
7227 | /* |
7228 | * Record the perf text poke event after the ksymbol register | |
7229 | * event. | |
7230 | */ | |
7231 | perf_event_text_poke((void *)ops->trampoline, NULL, 0, | |
7232 | (void *)ops->trampoline, | |
7233 | ops->trampoline_size); | |
dd9ddf46 | 7234 | } |
f3bea491 SRRH |
7235 | } |
7236 | ||
04ec7bb6 SRV |
7237 | void ftrace_init_trace_array(struct trace_array *tr) |
7238 | { | |
7239 | INIT_LIST_HEAD(&tr->func_probes); | |
673feb9d SRV |
7240 | INIT_LIST_HEAD(&tr->mod_trace); |
7241 | INIT_LIST_HEAD(&tr->mod_notrace); | |
04ec7bb6 | 7242 | } |
3d083395 | 7243 | #else |
0b6e4d56 | 7244 | |
3306fc4a | 7245 | struct ftrace_ops global_ops = { |
bd69c30b | 7246 | .func = ftrace_stub, |
a25d036d | 7247 | .flags = FTRACE_OPS_FL_INITIALIZED | |
e3eea140 | 7248 | FTRACE_OPS_FL_PID, |
bd69c30b SR |
7249 | }; |
7250 | ||
0b6e4d56 FW |
7251 | static int __init ftrace_nodyn_init(void) |
7252 | { | |
7253 | ftrace_enabled = 1; | |
7254 | return 0; | |
7255 | } | |
6f415672 | 7256 | core_initcall(ftrace_nodyn_init); |
0b6e4d56 | 7257 | |
8434dc93 | 7258 | static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; } |
e1effa01 | 7259 | static inline void ftrace_startup_all(int command) { } |
8a56d776 | 7260 | |
f3bea491 SRRH |
7261 | static void ftrace_update_trampoline(struct ftrace_ops *ops) |
7262 | { | |
7263 | } | |
7264 | ||
3d083395 SR |
7265 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
7266 | ||
4104d326 SRRH |
7267 | __init void ftrace_init_global_array_ops(struct trace_array *tr) |
7268 | { | |
7269 | tr->ops = &global_ops; | |
7270 | tr->ops->private = tr; | |
04ec7bb6 | 7271 | ftrace_init_trace_array(tr); |
4104d326 SRRH |
7272 | } |
7273 | ||
7274 | void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func) | |
7275 | { | |
7276 | /* If we filter on pids, update to use the pid function */ | |
7277 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL) { | |
7278 | if (WARN_ON(tr->ops->func != ftrace_stub)) | |
7279 | printk("ftrace ops had %pS for function\n", | |
7280 | tr->ops->func); | |
4104d326 SRRH |
7281 | } |
7282 | tr->ops->func = func; | |
7283 | tr->ops->private = tr; | |
7284 | } | |
7285 | ||
7286 | void ftrace_reset_array_ops(struct trace_array *tr) | |
7287 | { | |
7288 | tr->ops->func = ftrace_stub; | |
7289 | } | |
7290 | ||
fabe38ab | 7291 | static nokprobe_inline void |
2f5f6ad9 | 7292 | __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, |
d19ad077 | 7293 | struct ftrace_ops *ignored, struct ftrace_regs *fregs) |
b848914c | 7294 | { |
d19ad077 | 7295 | struct pt_regs *regs = ftrace_get_regs(fregs); |
cdbe61bf | 7296 | struct ftrace_ops *op; |
edc15caf | 7297 | int bit; |
b848914c | 7298 | |
ce5e4803 | 7299 | /* |
7300 | * The ftrace_test_and_set_recursion() will disable preemption, | |
7301 | * which is required since some of the ops may be dynamically | |
7302 | * allocated, they must be freed after a synchronize_rcu(). | |
7303 | */ | |
ed65df63 | 7304 | bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START); |
edc15caf SR |
7305 | if (bit < 0) |
7306 | return; | |
b1cff0ad | 7307 | |
0a016409 | 7308 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
2fa717a0 SRV |
7309 | /* Stub functions don't need to be called nor tested */ |
7310 | if (op->flags & FTRACE_OPS_FL_STUB) | |
7311 | continue; | |
ba27f2bc SRRH |
7312 | /* |
7313 | * Check the following for each ops before calling their func: | |
7314 | * if RCU flag is set, then rcu_is_watching() must be true | |
ba27f2bc SRRH |
7315 | * Otherwise test if the ip matches the ops filter |
7316 | * | |
7317 | * If any of the above fails then the op->func() is not executed. | |
7318 | */ | |
7319 | if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) && | |
ba27f2bc | 7320 | ftrace_ops_test(op, ip, regs)) { |
1d48d596 SRRH |
7321 | if (FTRACE_WARN_ON(!op->func)) { |
7322 | pr_warn("op=%p %pS\n", op, op); | |
4104d326 SRRH |
7323 | goto out; |
7324 | } | |
d19ad077 | 7325 | op->func(ip, parent_ip, op, fregs); |
4104d326 | 7326 | } |
0a016409 | 7327 | } while_for_each_ftrace_op(op); |
4104d326 | 7328 | out: |
edc15caf | 7329 | trace_clear_recursion(bit); |
b848914c SR |
7330 | } |
7331 | ||
2f5f6ad9 SR |
7332 | /* |
7333 | * Some archs only support passing ip and parent_ip. Even though | |
7334 | * the list function ignores the op parameter, we do not want any | |
7335 | * C side effects, where a function is called without the caller | |
7336 | * sending a third parameter. | |
a1e2e31d SR |
7337 | * Archs are to support both the regs and ftrace_ops at the same time. |
7338 | * If they support ftrace_ops, it is assumed they support regs. | |
7339 | * If call backs want to use regs, they must either check for regs | |
06aeaaea MH |
7340 | * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS. |
7341 | * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved. | |
a1e2e31d | 7342 | * An architecture can pass partial regs with ftrace_ops and still |
b8ec330a | 7343 | * set the ARCH_SUPPORTS_FTRACE_OPS. |
34cdd18b SRV |
7344 | * |
7345 | * In vmlinux.lds.h, ftrace_ops_list_func() is defined to be | |
7346 | * arch_ftrace_ops_list_func. | |
2f5f6ad9 SR |
7347 | */ |
7348 | #if ARCH_SUPPORTS_FTRACE_OPS | |
34cdd18b SRV |
7349 | void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, |
7350 | struct ftrace_ops *op, struct ftrace_regs *fregs) | |
2f5f6ad9 | 7351 | { |
d19ad077 | 7352 | __ftrace_ops_list_func(ip, parent_ip, NULL, fregs); |
2f5f6ad9 SR |
7353 | } |
7354 | #else | |
34cdd18b | 7355 | void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip) |
2f5f6ad9 | 7356 | { |
a1e2e31d | 7357 | __ftrace_ops_list_func(ip, parent_ip, NULL, NULL); |
2f5f6ad9 SR |
7358 | } |
7359 | #endif | |
34cdd18b | 7360 | NOKPROBE_SYMBOL(arch_ftrace_ops_list_func); |
2f5f6ad9 | 7361 | |
f1ff6348 SRRH |
7362 | /* |
7363 | * If there's only one function registered but it does not support | |
78a01feb ZY |
7364 | * recursion, needs RCU protection, then this function will be called |
7365 | * by the mcount trampoline. | |
f1ff6348 | 7366 | */ |
c68c0fa2 | 7367 | static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip, |
d19ad077 | 7368 | struct ftrace_ops *op, struct ftrace_regs *fregs) |
f1ff6348 SRRH |
7369 | { |
7370 | int bit; | |
7371 | ||
ed65df63 | 7372 | bit = trace_test_and_set_recursion(ip, parent_ip, TRACE_LIST_START); |
f1ff6348 SRRH |
7373 | if (bit < 0) |
7374 | return; | |
7375 | ||
b40341fa | 7376 | if (!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) |
d19ad077 | 7377 | op->func(ip, parent_ip, op, fregs); |
c68c0fa2 | 7378 | |
f1ff6348 SRRH |
7379 | trace_clear_recursion(bit); |
7380 | } | |
fabe38ab | 7381 | NOKPROBE_SYMBOL(ftrace_ops_assist_func); |
f1ff6348 | 7382 | |
87354059 SRRH |
7383 | /** |
7384 | * ftrace_ops_get_func - get the function a trampoline should call | |
7385 | * @ops: the ops to get the function for | |
7386 | * | |
7387 | * Normally the mcount trampoline will call the ops->func, but there | |
7388 | * are times that it should not. For example, if the ops does not | |
7389 | * have its own recursion protection, then it should call the | |
3a150df9 | 7390 | * ftrace_ops_assist_func() instead. |
87354059 SRRH |
7391 | * |
7392 | * Returns the function that the trampoline should call for @ops. | |
7393 | */ | |
7394 | ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops) | |
7395 | { | |
87354059 | 7396 | /* |
a25d036d SRV |
7397 | * If the function does not handle recursion or needs to be RCU safe, |
7398 | * then we need to call the assist handler. | |
87354059 | 7399 | */ |
a25d036d SRV |
7400 | if (ops->flags & (FTRACE_OPS_FL_RECURSION | |
7401 | FTRACE_OPS_FL_RCU)) | |
c68c0fa2 | 7402 | return ftrace_ops_assist_func; |
87354059 SRRH |
7403 | |
7404 | return ops->func; | |
7405 | } | |
7406 | ||
345ddcc8 SRRH |
7407 | static void |
7408 | ftrace_filter_pid_sched_switch_probe(void *data, bool preempt, | |
fa2c3254 | 7409 | struct task_struct *prev, |
9c2136be DK |
7410 | struct task_struct *next, |
7411 | unsigned int prev_state) | |
978f3a45 | 7412 | { |
345ddcc8 SRRH |
7413 | struct trace_array *tr = data; |
7414 | struct trace_pid_list *pid_list; | |
b3b1e6ed | 7415 | struct trace_pid_list *no_pid_list; |
978f3a45 | 7416 | |
345ddcc8 | 7417 | pid_list = rcu_dereference_sched(tr->function_pids); |
b3b1e6ed | 7418 | no_pid_list = rcu_dereference_sched(tr->function_no_pids); |
e32d8956 | 7419 | |
b3b1e6ed | 7420 | if (trace_ignore_this_task(pid_list, no_pid_list, next)) |
717e3f5e SRV |
7421 | this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, |
7422 | FTRACE_PID_IGNORE); | |
7423 | else | |
7424 | this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, | |
7425 | next->pid); | |
978f3a45 SR |
7426 | } |
7427 | ||
1e10486f NK |
7428 | static void |
7429 | ftrace_pid_follow_sched_process_fork(void *data, | |
7430 | struct task_struct *self, | |
7431 | struct task_struct *task) | |
7432 | { | |
7433 | struct trace_pid_list *pid_list; | |
7434 | struct trace_array *tr = data; | |
7435 | ||
7436 | pid_list = rcu_dereference_sched(tr->function_pids); | |
7437 | trace_filter_add_remove_task(pid_list, self, task); | |
b3b1e6ed SRV |
7438 | |
7439 | pid_list = rcu_dereference_sched(tr->function_no_pids); | |
7440 | trace_filter_add_remove_task(pid_list, self, task); | |
1e10486f NK |
7441 | } |
7442 | ||
7443 | static void | |
7444 | ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task) | |
7445 | { | |
7446 | struct trace_pid_list *pid_list; | |
7447 | struct trace_array *tr = data; | |
7448 | ||
7449 | pid_list = rcu_dereference_sched(tr->function_pids); | |
7450 | trace_filter_add_remove_task(pid_list, NULL, task); | |
b3b1e6ed SRV |
7451 | |
7452 | pid_list = rcu_dereference_sched(tr->function_no_pids); | |
7453 | trace_filter_add_remove_task(pid_list, NULL, task); | |
1e10486f NK |
7454 | } |
7455 | ||
7456 | void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) | |
7457 | { | |
7458 | if (enable) { | |
7459 | register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, | |
7460 | tr); | |
afcab636 | 7461 | register_trace_sched_process_free(ftrace_pid_follow_sched_process_exit, |
1e10486f NK |
7462 | tr); |
7463 | } else { | |
7464 | unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, | |
7465 | tr); | |
afcab636 | 7466 | unregister_trace_sched_process_free(ftrace_pid_follow_sched_process_exit, |
1e10486f NK |
7467 | tr); |
7468 | } | |
7469 | } | |
7470 | ||
b3b1e6ed | 7471 | static void clear_ftrace_pids(struct trace_array *tr, int type) |
e32d8956 | 7472 | { |
345ddcc8 | 7473 | struct trace_pid_list *pid_list; |
b3b1e6ed | 7474 | struct trace_pid_list *no_pid_list; |
345ddcc8 | 7475 | int cpu; |
e32d8956 | 7476 | |
345ddcc8 SRRH |
7477 | pid_list = rcu_dereference_protected(tr->function_pids, |
7478 | lockdep_is_held(&ftrace_lock)); | |
b3b1e6ed SRV |
7479 | no_pid_list = rcu_dereference_protected(tr->function_no_pids, |
7480 | lockdep_is_held(&ftrace_lock)); | |
7481 | ||
7482 | /* Make sure there's something to do */ | |
27683626 | 7483 | if (!pid_type_enabled(type, pid_list, no_pid_list)) |
345ddcc8 | 7484 | return; |
229c4ef8 | 7485 | |
b3b1e6ed | 7486 | /* See if the pids still need to be checked after this */ |
27683626 | 7487 | if (!still_need_pid_events(type, pid_list, no_pid_list)) { |
b3b1e6ed SRV |
7488 | unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr); |
7489 | for_each_possible_cpu(cpu) | |
7490 | per_cpu_ptr(tr->array_buffer.data, cpu)->ftrace_ignore_pid = FTRACE_PID_TRACE; | |
7491 | } | |
e32d8956 | 7492 | |
b3b1e6ed SRV |
7493 | if (type & TRACE_PIDS) |
7494 | rcu_assign_pointer(tr->function_pids, NULL); | |
978f3a45 | 7495 | |
b3b1e6ed SRV |
7496 | if (type & TRACE_NO_PIDS) |
7497 | rcu_assign_pointer(tr->function_no_pids, NULL); | |
978f3a45 | 7498 | |
345ddcc8 | 7499 | /* Wait till all users are no longer using pid filtering */ |
74401729 | 7500 | synchronize_rcu(); |
e32d8956 | 7501 | |
b3b1e6ed | 7502 | if ((type & TRACE_PIDS) && pid_list) |
6954e415 | 7503 | trace_pid_list_free(pid_list); |
b3b1e6ed SRV |
7504 | |
7505 | if ((type & TRACE_NO_PIDS) && no_pid_list) | |
6954e415 | 7506 | trace_pid_list_free(no_pid_list); |
e32d8956 SR |
7507 | } |
7508 | ||
d879d0b8 NK |
7509 | void ftrace_clear_pids(struct trace_array *tr) |
7510 | { | |
7511 | mutex_lock(&ftrace_lock); | |
7512 | ||
b3b1e6ed | 7513 | clear_ftrace_pids(tr, TRACE_PIDS | TRACE_NO_PIDS); |
d879d0b8 NK |
7514 | |
7515 | mutex_unlock(&ftrace_lock); | |
7516 | } | |
7517 | ||
b3b1e6ed | 7518 | static void ftrace_pid_reset(struct trace_array *tr, int type) |
df4fc315 | 7519 | { |
756d17ee | 7520 | mutex_lock(&ftrace_lock); |
b3b1e6ed | 7521 | clear_ftrace_pids(tr, type); |
978f3a45 | 7522 | |
756d17ee | 7523 | ftrace_update_pid_func(); |
e1effa01 | 7524 | ftrace_startup_all(0); |
756d17ee | 7525 | |
7526 | mutex_unlock(&ftrace_lock); | |
756d17ee | 7527 | } |
7528 | ||
345ddcc8 SRRH |
7529 | /* Greater than any max PID */ |
7530 | #define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1) | |
df4fc315 | 7531 | |
756d17ee | 7532 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
345ddcc8 | 7533 | __acquires(RCU) |
756d17ee | 7534 | { |
345ddcc8 SRRH |
7535 | struct trace_pid_list *pid_list; |
7536 | struct trace_array *tr = m->private; | |
7537 | ||
756d17ee | 7538 | mutex_lock(&ftrace_lock); |
345ddcc8 SRRH |
7539 | rcu_read_lock_sched(); |
7540 | ||
7541 | pid_list = rcu_dereference_sched(tr->function_pids); | |
756d17ee | 7542 | |
345ddcc8 SRRH |
7543 | if (!pid_list) |
7544 | return !(*pos) ? FTRACE_NO_PIDS : NULL; | |
756d17ee | 7545 | |
345ddcc8 | 7546 | return trace_pid_start(pid_list, pos); |
756d17ee | 7547 | } |
7548 | ||
7549 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
7550 | { | |
345ddcc8 SRRH |
7551 | struct trace_array *tr = m->private; |
7552 | struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids); | |
7553 | ||
e4075e8b VA |
7554 | if (v == FTRACE_NO_PIDS) { |
7555 | (*pos)++; | |
756d17ee | 7556 | return NULL; |
e4075e8b | 7557 | } |
345ddcc8 | 7558 | return trace_pid_next(pid_list, v, pos); |
756d17ee | 7559 | } |
7560 | ||
7561 | static void fpid_stop(struct seq_file *m, void *p) | |
345ddcc8 | 7562 | __releases(RCU) |
756d17ee | 7563 | { |
345ddcc8 | 7564 | rcu_read_unlock_sched(); |
756d17ee | 7565 | mutex_unlock(&ftrace_lock); |
7566 | } | |
7567 | ||
7568 | static int fpid_show(struct seq_file *m, void *v) | |
7569 | { | |
345ddcc8 | 7570 | if (v == FTRACE_NO_PIDS) { |
fa6f0cc7 | 7571 | seq_puts(m, "no pid\n"); |
756d17ee | 7572 | return 0; |
7573 | } | |
7574 | ||
345ddcc8 | 7575 | return trace_pid_show(m, v); |
756d17ee | 7576 | } |
7577 | ||
7578 | static const struct seq_operations ftrace_pid_sops = { | |
7579 | .start = fpid_start, | |
7580 | .next = fpid_next, | |
7581 | .stop = fpid_stop, | |
7582 | .show = fpid_show, | |
7583 | }; | |
7584 | ||
b3b1e6ed SRV |
7585 | static void *fnpid_start(struct seq_file *m, loff_t *pos) |
7586 | __acquires(RCU) | |
7587 | { | |
7588 | struct trace_pid_list *pid_list; | |
7589 | struct trace_array *tr = m->private; | |
7590 | ||
7591 | mutex_lock(&ftrace_lock); | |
7592 | rcu_read_lock_sched(); | |
7593 | ||
7594 | pid_list = rcu_dereference_sched(tr->function_no_pids); | |
7595 | ||
7596 | if (!pid_list) | |
7597 | return !(*pos) ? FTRACE_NO_PIDS : NULL; | |
7598 | ||
7599 | return trace_pid_start(pid_list, pos); | |
7600 | } | |
7601 | ||
7602 | static void *fnpid_next(struct seq_file *m, void *v, loff_t *pos) | |
756d17ee | 7603 | { |
b3b1e6ed SRV |
7604 | struct trace_array *tr = m->private; |
7605 | struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_no_pids); | |
7606 | ||
7607 | if (v == FTRACE_NO_PIDS) { | |
7608 | (*pos)++; | |
7609 | return NULL; | |
7610 | } | |
7611 | return trace_pid_next(pid_list, v, pos); | |
7612 | } | |
7613 | ||
7614 | static const struct seq_operations ftrace_no_pid_sops = { | |
7615 | .start = fnpid_start, | |
7616 | .next = fnpid_next, | |
7617 | .stop = fpid_stop, | |
7618 | .show = fpid_show, | |
7619 | }; | |
7620 | ||
7621 | static int pid_open(struct inode *inode, struct file *file, int type) | |
7622 | { | |
7623 | const struct seq_operations *seq_ops; | |
345ddcc8 SRRH |
7624 | struct trace_array *tr = inode->i_private; |
7625 | struct seq_file *m; | |
756d17ee | 7626 | int ret = 0; |
7627 | ||
8530dec6 SRV |
7628 | ret = tracing_check_open_get_tr(tr); |
7629 | if (ret) | |
7630 | return ret; | |
345ddcc8 | 7631 | |
756d17ee | 7632 | if ((file->f_mode & FMODE_WRITE) && |
7633 | (file->f_flags & O_TRUNC)) | |
b3b1e6ed SRV |
7634 | ftrace_pid_reset(tr, type); |
7635 | ||
7636 | switch (type) { | |
7637 | case TRACE_PIDS: | |
7638 | seq_ops = &ftrace_pid_sops; | |
7639 | break; | |
7640 | case TRACE_NO_PIDS: | |
7641 | seq_ops = &ftrace_no_pid_sops; | |
7642 | break; | |
026bb845 KC |
7643 | default: |
7644 | trace_array_put(tr); | |
7645 | WARN_ON_ONCE(1); | |
7646 | return -EINVAL; | |
b3b1e6ed | 7647 | } |
756d17ee | 7648 | |
b3b1e6ed | 7649 | ret = seq_open(file, seq_ops); |
345ddcc8 SRRH |
7650 | if (ret < 0) { |
7651 | trace_array_put(tr); | |
7652 | } else { | |
7653 | m = file->private_data; | |
7654 | /* copy tr over to seq ops */ | |
7655 | m->private = tr; | |
7656 | } | |
756d17ee | 7657 | |
7658 | return ret; | |
7659 | } | |
7660 | ||
b3b1e6ed SRV |
7661 | static int |
7662 | ftrace_pid_open(struct inode *inode, struct file *file) | |
7663 | { | |
7664 | return pid_open(inode, file, TRACE_PIDS); | |
7665 | } | |
7666 | ||
7667 | static int | |
7668 | ftrace_no_pid_open(struct inode *inode, struct file *file) | |
7669 | { | |
7670 | return pid_open(inode, file, TRACE_NO_PIDS); | |
7671 | } | |
7672 | ||
345ddcc8 SRRH |
7673 | static void ignore_task_cpu(void *data) |
7674 | { | |
7675 | struct trace_array *tr = data; | |
7676 | struct trace_pid_list *pid_list; | |
b3b1e6ed | 7677 | struct trace_pid_list *no_pid_list; |
345ddcc8 SRRH |
7678 | |
7679 | /* | |
7680 | * This function is called by on_each_cpu() while the | |
7681 | * event_mutex is held. | |
7682 | */ | |
7683 | pid_list = rcu_dereference_protected(tr->function_pids, | |
7684 | mutex_is_locked(&ftrace_lock)); | |
b3b1e6ed SRV |
7685 | no_pid_list = rcu_dereference_protected(tr->function_no_pids, |
7686 | mutex_is_locked(&ftrace_lock)); | |
345ddcc8 | 7687 | |
b3b1e6ed | 7688 | if (trace_ignore_this_task(pid_list, no_pid_list, current)) |
717e3f5e SRV |
7689 | this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, |
7690 | FTRACE_PID_IGNORE); | |
7691 | else | |
7692 | this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, | |
7693 | current->pid); | |
345ddcc8 SRRH |
7694 | } |
7695 | ||
df4fc315 | 7696 | static ssize_t |
b3b1e6ed SRV |
7697 | pid_write(struct file *filp, const char __user *ubuf, |
7698 | size_t cnt, loff_t *ppos, int type) | |
df4fc315 | 7699 | { |
345ddcc8 SRRH |
7700 | struct seq_file *m = filp->private_data; |
7701 | struct trace_array *tr = m->private; | |
b3b1e6ed SRV |
7702 | struct trace_pid_list *filtered_pids; |
7703 | struct trace_pid_list *other_pids; | |
345ddcc8 SRRH |
7704 | struct trace_pid_list *pid_list; |
7705 | ssize_t ret; | |
df4fc315 | 7706 | |
345ddcc8 SRRH |
7707 | if (!cnt) |
7708 | return 0; | |
7709 | ||
7710 | mutex_lock(&ftrace_lock); | |
7711 | ||
b3b1e6ed SRV |
7712 | switch (type) { |
7713 | case TRACE_PIDS: | |
7714 | filtered_pids = rcu_dereference_protected(tr->function_pids, | |
345ddcc8 | 7715 | lockdep_is_held(&ftrace_lock)); |
b3b1e6ed SRV |
7716 | other_pids = rcu_dereference_protected(tr->function_no_pids, |
7717 | lockdep_is_held(&ftrace_lock)); | |
7718 | break; | |
7719 | case TRACE_NO_PIDS: | |
7720 | filtered_pids = rcu_dereference_protected(tr->function_no_pids, | |
7721 | lockdep_is_held(&ftrace_lock)); | |
7722 | other_pids = rcu_dereference_protected(tr->function_pids, | |
345ddcc8 | 7723 | lockdep_is_held(&ftrace_lock)); |
b3b1e6ed | 7724 | break; |
026bb845 KC |
7725 | default: |
7726 | ret = -EINVAL; | |
7727 | WARN_ON_ONCE(1); | |
7728 | goto out; | |
b3b1e6ed | 7729 | } |
345ddcc8 SRRH |
7730 | |
7731 | ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt); | |
7732 | if (ret < 0) | |
7733 | goto out; | |
df4fc315 | 7734 | |
b3b1e6ed SRV |
7735 | switch (type) { |
7736 | case TRACE_PIDS: | |
7737 | rcu_assign_pointer(tr->function_pids, pid_list); | |
7738 | break; | |
7739 | case TRACE_NO_PIDS: | |
7740 | rcu_assign_pointer(tr->function_no_pids, pid_list); | |
7741 | break; | |
7742 | } | |
7743 | ||
df4fc315 | 7744 | |
345ddcc8 | 7745 | if (filtered_pids) { |
74401729 | 7746 | synchronize_rcu(); |
6954e415 | 7747 | trace_pid_list_free(filtered_pids); |
b3b1e6ed | 7748 | } else if (pid_list && !other_pids) { |
345ddcc8 SRRH |
7749 | /* Register a probe to set whether to ignore the tracing of a task */ |
7750 | register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr); | |
7751 | } | |
df4fc315 | 7752 | |
756d17ee | 7753 | /* |
345ddcc8 SRRH |
7754 | * Ignoring of pids is done at task switch. But we have to |
7755 | * check for those tasks that are currently running. | |
7756 | * Always do this in case a pid was appended or removed. | |
756d17ee | 7757 | */ |
345ddcc8 | 7758 | on_each_cpu(ignore_task_cpu, tr, 1); |
756d17ee | 7759 | |
345ddcc8 SRRH |
7760 | ftrace_update_pid_func(); |
7761 | ftrace_startup_all(0); | |
7762 | out: | |
7763 | mutex_unlock(&ftrace_lock); | |
df4fc315 | 7764 | |
345ddcc8 SRRH |
7765 | if (ret > 0) |
7766 | *ppos += ret; | |
df4fc315 | 7767 | |
345ddcc8 | 7768 | return ret; |
756d17ee | 7769 | } |
df4fc315 | 7770 | |
b3b1e6ed SRV |
7771 | static ssize_t |
7772 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
7773 | size_t cnt, loff_t *ppos) | |
7774 | { | |
7775 | return pid_write(filp, ubuf, cnt, ppos, TRACE_PIDS); | |
7776 | } | |
7777 | ||
7778 | static ssize_t | |
7779 | ftrace_no_pid_write(struct file *filp, const char __user *ubuf, | |
7780 | size_t cnt, loff_t *ppos) | |
7781 | { | |
7782 | return pid_write(filp, ubuf, cnt, ppos, TRACE_NO_PIDS); | |
7783 | } | |
7784 | ||
756d17ee | 7785 | static int |
7786 | ftrace_pid_release(struct inode *inode, struct file *file) | |
7787 | { | |
345ddcc8 | 7788 | struct trace_array *tr = inode->i_private; |
df4fc315 | 7789 | |
345ddcc8 SRRH |
7790 | trace_array_put(tr); |
7791 | ||
7792 | return seq_release(inode, file); | |
df4fc315 SR |
7793 | } |
7794 | ||
5e2336a0 | 7795 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 7796 | .open = ftrace_pid_open, |
7797 | .write = ftrace_pid_write, | |
7798 | .read = seq_read, | |
098c879e | 7799 | .llseek = tracing_lseek, |
756d17ee | 7800 | .release = ftrace_pid_release, |
df4fc315 SR |
7801 | }; |
7802 | ||
b3b1e6ed SRV |
7803 | static const struct file_operations ftrace_no_pid_fops = { |
7804 | .open = ftrace_no_pid_open, | |
7805 | .write = ftrace_no_pid_write, | |
7806 | .read = seq_read, | |
7807 | .llseek = tracing_lseek, | |
7808 | .release = ftrace_pid_release, | |
7809 | }; | |
7810 | ||
345ddcc8 | 7811 | void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer) |
df4fc315 | 7812 | { |
21ccc9cd | 7813 | trace_create_file("set_ftrace_pid", TRACE_MODE_WRITE, d_tracer, |
345ddcc8 | 7814 | tr, &ftrace_pid_fops); |
21ccc9cd SRV |
7815 | trace_create_file("set_ftrace_notrace_pid", TRACE_MODE_WRITE, |
7816 | d_tracer, tr, &ftrace_no_pid_fops); | |
df4fc315 | 7817 | } |
df4fc315 | 7818 | |
501c2375 SRRH |
7819 | void __init ftrace_init_tracefs_toplevel(struct trace_array *tr, |
7820 | struct dentry *d_tracer) | |
7821 | { | |
7822 | /* Only the top level directory has the dyn_tracefs and profile */ | |
7823 | WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL)); | |
7824 | ||
7825 | ftrace_init_dyn_tracefs(d_tracer); | |
7826 | ftrace_profile_tracefs(d_tracer); | |
7827 | } | |
7828 | ||
a2bb6a3d | 7829 | /** |
81adbdc0 | 7830 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
7831 | * |
7832 | * This function should be used by panic code. It stops ftrace | |
7833 | * but in a not so nice way. If you need to simply kill ftrace | |
7834 | * from a non-atomic section, use ftrace_kill. | |
7835 | */ | |
81adbdc0 | 7836 | void ftrace_kill(void) |
a2bb6a3d SR |
7837 | { |
7838 | ftrace_disabled = 1; | |
7839 | ftrace_enabled = 0; | |
5ccba64a | 7840 | ftrace_trace_function = ftrace_stub; |
a2bb6a3d SR |
7841 | } |
7842 | ||
e0a413f6 | 7843 | /** |
6130722f SRV |
7844 | * ftrace_is_dead - Test if ftrace is dead or not. |
7845 | * | |
7846 | * Returns 1 if ftrace is "dead", zero otherwise. | |
e0a413f6 SR |
7847 | */ |
7848 | int ftrace_is_dead(void) | |
7849 | { | |
7850 | return ftrace_disabled; | |
7851 | } | |
7852 | ||
53cd885b SL |
7853 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS |
7854 | /* | |
7855 | * When registering ftrace_ops with IPMODIFY, it is necessary to make sure | |
7856 | * it doesn't conflict with any direct ftrace_ops. If there is existing | |
7857 | * direct ftrace_ops on a kernel function being patched, call | |
7858 | * FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER on it to enable sharing. | |
7859 | * | |
7860 | * @ops: ftrace_ops being registered. | |
7861 | * | |
7862 | * Returns: | |
7863 | * 0 on success; | |
7864 | * Negative on failure. | |
7865 | */ | |
7866 | static int prepare_direct_functions_for_ipmodify(struct ftrace_ops *ops) | |
7867 | { | |
7868 | struct ftrace_func_entry *entry; | |
7869 | struct ftrace_hash *hash; | |
7870 | struct ftrace_ops *op; | |
7871 | int size, i, ret; | |
7872 | ||
7873 | lockdep_assert_held_once(&direct_mutex); | |
7874 | ||
7875 | if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY)) | |
7876 | return 0; | |
7877 | ||
7878 | hash = ops->func_hash->filter_hash; | |
7879 | size = 1 << hash->size_bits; | |
7880 | for (i = 0; i < size; i++) { | |
7881 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
7882 | unsigned long ip = entry->ip; | |
7883 | bool found_op = false; | |
7884 | ||
7885 | mutex_lock(&ftrace_lock); | |
7886 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
7887 | if (!(op->flags & FTRACE_OPS_FL_DIRECT)) | |
7888 | continue; | |
7889 | if (ops_references_ip(op, ip)) { | |
7890 | found_op = true; | |
7891 | break; | |
7892 | } | |
7893 | } while_for_each_ftrace_op(op); | |
7894 | mutex_unlock(&ftrace_lock); | |
7895 | ||
7896 | if (found_op) { | |
7897 | if (!op->ops_func) | |
7898 | return -EBUSY; | |
7899 | ||
7900 | ret = op->ops_func(op, FTRACE_OPS_CMD_ENABLE_SHARE_IPMODIFY_PEER); | |
7901 | if (ret) | |
7902 | return ret; | |
7903 | } | |
7904 | } | |
7905 | } | |
7906 | ||
7907 | return 0; | |
7908 | } | |
7909 | ||
7910 | /* | |
7911 | * Similar to prepare_direct_functions_for_ipmodify, clean up after ops | |
7912 | * with IPMODIFY is unregistered. The cleanup is optional for most DIRECT | |
7913 | * ops. | |
7914 | */ | |
7915 | static void cleanup_direct_functions_after_ipmodify(struct ftrace_ops *ops) | |
7916 | { | |
7917 | struct ftrace_func_entry *entry; | |
7918 | struct ftrace_hash *hash; | |
7919 | struct ftrace_ops *op; | |
7920 | int size, i; | |
7921 | ||
7922 | if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY)) | |
7923 | return; | |
7924 | ||
7925 | mutex_lock(&direct_mutex); | |
7926 | ||
7927 | hash = ops->func_hash->filter_hash; | |
7928 | size = 1 << hash->size_bits; | |
7929 | for (i = 0; i < size; i++) { | |
7930 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
7931 | unsigned long ip = entry->ip; | |
7932 | bool found_op = false; | |
7933 | ||
7934 | mutex_lock(&ftrace_lock); | |
7935 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
7936 | if (!(op->flags & FTRACE_OPS_FL_DIRECT)) | |
7937 | continue; | |
7938 | if (ops_references_ip(op, ip)) { | |
7939 | found_op = true; | |
7940 | break; | |
7941 | } | |
7942 | } while_for_each_ftrace_op(op); | |
7943 | mutex_unlock(&ftrace_lock); | |
7944 | ||
7945 | /* The cleanup is optional, ignore any errors */ | |
7946 | if (found_op && op->ops_func) | |
7947 | op->ops_func(op, FTRACE_OPS_CMD_DISABLE_SHARE_IPMODIFY_PEER); | |
7948 | } | |
7949 | } | |
7950 | mutex_unlock(&direct_mutex); | |
7951 | } | |
7952 | ||
7953 | #define lock_direct_mutex() mutex_lock(&direct_mutex) | |
7954 | #define unlock_direct_mutex() mutex_unlock(&direct_mutex) | |
7955 | ||
7956 | #else /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ | |
7957 | ||
7958 | static int prepare_direct_functions_for_ipmodify(struct ftrace_ops *ops) | |
7959 | { | |
7960 | return 0; | |
7961 | } | |
7962 | ||
7963 | static void cleanup_direct_functions_after_ipmodify(struct ftrace_ops *ops) | |
7964 | { | |
7965 | } | |
7966 | ||
7967 | #define lock_direct_mutex() do { } while (0) | |
7968 | #define unlock_direct_mutex() do { } while (0) | |
7969 | ||
7970 | #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ | |
7971 | ||
7972 | /* | |
7973 | * Similar to register_ftrace_function, except we don't lock direct_mutex. | |
7974 | */ | |
7975 | static int register_ftrace_function_nolock(struct ftrace_ops *ops) | |
7976 | { | |
7977 | int ret; | |
7978 | ||
7979 | ftrace_ops_init(ops); | |
7980 | ||
7981 | mutex_lock(&ftrace_lock); | |
7982 | ||
7983 | ret = ftrace_startup(ops, 0); | |
7984 | ||
7985 | mutex_unlock(&ftrace_lock); | |
7986 | ||
7987 | return ret; | |
7988 | } | |
7989 | ||
16444a8a | 7990 | /** |
3d083395 | 7991 | * register_ftrace_function - register a function for profiling |
78cbc651 | 7992 | * @ops: ops structure that holds the function for profiling. |
16444a8a | 7993 | * |
3d083395 SR |
7994 | * Register a function to be called by all functions in the |
7995 | * kernel. | |
7996 | * | |
7997 | * Note: @ops->func and all the functions it calls must be labeled | |
7998 | * with "notrace", otherwise it will go into a | |
7999 | * recursive loop. | |
16444a8a | 8000 | */ |
3d083395 | 8001 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 8002 | { |
3b1a8f45 | 8003 | int ret; |
4eebcc81 | 8004 | |
53cd885b SL |
8005 | lock_direct_mutex(); |
8006 | ret = prepare_direct_functions_for_ipmodify(ops); | |
8007 | if (ret < 0) | |
8008 | goto out_unlock; | |
b848914c | 8009 | |
53cd885b | 8010 | ret = register_ftrace_function_nolock(ops); |
8d240dd8 | 8011 | |
53cd885b SL |
8012 | out_unlock: |
8013 | unlock_direct_mutex(); | |
b0fc494f | 8014 | return ret; |
3d083395 | 8015 | } |
cdbe61bf | 8016 | EXPORT_SYMBOL_GPL(register_ftrace_function); |
3d083395 SR |
8017 | |
8018 | /** | |
32632920 | 8019 | * unregister_ftrace_function - unregister a function for profiling. |
78cbc651 | 8020 | * @ops: ops structure that holds the function to unregister |
3d083395 SR |
8021 | * |
8022 | * Unregister a function that was added to be called by ftrace profiling. | |
8023 | */ | |
8024 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
8025 | { | |
8026 | int ret; | |
8027 | ||
e6ea44e9 | 8028 | mutex_lock(&ftrace_lock); |
8a56d776 | 8029 | ret = ftrace_shutdown(ops, 0); |
e6ea44e9 | 8030 | mutex_unlock(&ftrace_lock); |
b0fc494f | 8031 | |
53cd885b | 8032 | cleanup_direct_functions_after_ipmodify(ops); |
b0fc494f SR |
8033 | return ret; |
8034 | } | |
cdbe61bf | 8035 | EXPORT_SYMBOL_GPL(unregister_ftrace_function); |
b0fc494f | 8036 | |
bed0d9a5 JO |
8037 | static int symbols_cmp(const void *a, const void *b) |
8038 | { | |
8039 | const char **str_a = (const char **) a; | |
8040 | const char **str_b = (const char **) b; | |
8041 | ||
8042 | return strcmp(*str_a, *str_b); | |
8043 | } | |
8044 | ||
8045 | struct kallsyms_data { | |
8046 | unsigned long *addrs; | |
8047 | const char **syms; | |
8048 | size_t cnt; | |
8049 | size_t found; | |
8050 | }; | |
8051 | ||
3640bf85 JO |
8052 | /* This function gets called for all kernel and module symbols |
8053 | * and returns 1 in case we resolved all the requested symbols, | |
8054 | * 0 otherwise. | |
8055 | */ | |
3703bd54 | 8056 | static int kallsyms_callback(void *data, const char *name, unsigned long addr) |
bed0d9a5 JO |
8057 | { |
8058 | struct kallsyms_data *args = data; | |
eb1b2985 JO |
8059 | const char **sym; |
8060 | int idx; | |
bed0d9a5 | 8061 | |
eb1b2985 JO |
8062 | sym = bsearch(&name, args->syms, args->cnt, sizeof(*args->syms), symbols_cmp); |
8063 | if (!sym) | |
8064 | return 0; | |
8065 | ||
8066 | idx = sym - args->syms; | |
8067 | if (args->addrs[idx]) | |
bed0d9a5 JO |
8068 | return 0; |
8069 | ||
9d68c19c | 8070 | if (!ftrace_location(addr)) |
bed0d9a5 JO |
8071 | return 0; |
8072 | ||
eb1b2985 JO |
8073 | args->addrs[idx] = addr; |
8074 | args->found++; | |
bed0d9a5 JO |
8075 | return args->found == args->cnt ? 1 : 0; |
8076 | } | |
8077 | ||
8078 | /** | |
8079 | * ftrace_lookup_symbols - Lookup addresses for array of symbols | |
8080 | * | |
8081 | * @sorted_syms: array of symbols pointers symbols to resolve, | |
8082 | * must be alphabetically sorted | |
8083 | * @cnt: number of symbols/addresses in @syms/@addrs arrays | |
8084 | * @addrs: array for storing resulting addresses | |
8085 | * | |
8086 | * This function looks up addresses for array of symbols provided in | |
8087 | * @syms array (must be alphabetically sorted) and stores them in | |
8088 | * @addrs array, which needs to be big enough to store at least @cnt | |
8089 | * addresses. | |
8090 | * | |
8091 | * This function returns 0 if all provided symbols are found, | |
8092 | * -ESRCH otherwise. | |
8093 | */ | |
8094 | int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs) | |
8095 | { | |
8096 | struct kallsyms_data args; | |
3640bf85 | 8097 | int found_all; |
bed0d9a5 | 8098 | |
eb1b2985 | 8099 | memset(addrs, 0, sizeof(*addrs) * cnt); |
bed0d9a5 JO |
8100 | args.addrs = addrs; |
8101 | args.syms = sorted_syms; | |
8102 | args.cnt = cnt; | |
8103 | args.found = 0; | |
3640bf85 JO |
8104 | |
8105 | found_all = kallsyms_on_each_symbol(kallsyms_callback, &args); | |
8106 | if (found_all) | |
8107 | return 0; | |
07cc2c93 | 8108 | found_all = module_kallsyms_on_each_symbol(NULL, kallsyms_callback, &args); |
3640bf85 | 8109 | return found_all ? 0 : -ESRCH; |
bed0d9a5 | 8110 | } |
44d35720 | 8111 | |
5d79fa0d | 8112 | #ifdef CONFIG_SYSCTL |
8fd7c214 LC |
8113 | |
8114 | #ifdef CONFIG_DYNAMIC_FTRACE | |
f8b7d2b4 LC |
8115 | static void ftrace_startup_sysctl(void) |
8116 | { | |
8117 | int command; | |
8118 | ||
8119 | if (unlikely(ftrace_disabled)) | |
8120 | return; | |
8121 | ||
8122 | /* Force update next time */ | |
8123 | saved_ftrace_func = NULL; | |
8124 | /* ftrace_start_up is true if we want ftrace running */ | |
8125 | if (ftrace_start_up) { | |
8126 | command = FTRACE_UPDATE_CALLS; | |
8127 | if (ftrace_graph_active) | |
8128 | command |= FTRACE_START_FUNC_RET; | |
8129 | ftrace_startup_enable(command); | |
8130 | } | |
8131 | } | |
8132 | ||
8133 | static void ftrace_shutdown_sysctl(void) | |
8134 | { | |
8135 | int command; | |
8136 | ||
8137 | if (unlikely(ftrace_disabled)) | |
8138 | return; | |
8139 | ||
8140 | /* ftrace_start_up is true if ftrace is running */ | |
8141 | if (ftrace_start_up) { | |
8142 | command = FTRACE_DISABLE_CALLS; | |
8143 | if (ftrace_graph_active) | |
8144 | command |= FTRACE_STOP_FUNC_RET; | |
8145 | ftrace_run_update_code(command); | |
8146 | } | |
8147 | } | |
8fd7c214 LC |
8148 | #else |
8149 | # define ftrace_startup_sysctl() do { } while (0) | |
8150 | # define ftrace_shutdown_sysctl() do { } while (0) | |
8151 | #endif /* CONFIG_DYNAMIC_FTRACE */ | |
f8b7d2b4 | 8152 | |
7162431d MB |
8153 | static bool is_permanent_ops_registered(void) |
8154 | { | |
8155 | struct ftrace_ops *op; | |
8156 | ||
8157 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
8158 | if (op->flags & FTRACE_OPS_FL_PERMANENT) | |
8159 | return true; | |
8160 | } while_for_each_ftrace_op(op); | |
8161 | ||
8162 | return false; | |
8163 | } | |
8164 | ||
8e4e83b2 | 8165 | static int |
b0fc494f | 8166 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
54fa9ba5 | 8167 | void *buffer, size_t *lenp, loff_t *ppos) |
b0fc494f | 8168 | { |
45a4a237 | 8169 | int ret = -ENODEV; |
4eebcc81 | 8170 | |
e6ea44e9 | 8171 | mutex_lock(&ftrace_lock); |
b0fc494f | 8172 | |
45a4a237 SR |
8173 | if (unlikely(ftrace_disabled)) |
8174 | goto out; | |
8175 | ||
8176 | ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
b0fc494f | 8177 | |
a32c7765 | 8178 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
8179 | goto out; |
8180 | ||
b0fc494f SR |
8181 | if (ftrace_enabled) { |
8182 | ||
b0fc494f | 8183 | /* we are starting ftrace again */ |
f86f4180 CZ |
8184 | if (rcu_dereference_protected(ftrace_ops_list, |
8185 | lockdep_is_held(&ftrace_lock)) != &ftrace_list_end) | |
5000c418 | 8186 | update_ftrace_function(); |
b0fc494f | 8187 | |
524a3868 SRRH |
8188 | ftrace_startup_sysctl(); |
8189 | ||
b0fc494f | 8190 | } else { |
7162431d MB |
8191 | if (is_permanent_ops_registered()) { |
8192 | ftrace_enabled = true; | |
8193 | ret = -EBUSY; | |
8194 | goto out; | |
8195 | } | |
8196 | ||
b0fc494f SR |
8197 | /* stopping ftrace calls (just send to ftrace_stub) */ |
8198 | ftrace_trace_function = ftrace_stub; | |
8199 | ||
8200 | ftrace_shutdown_sysctl(); | |
8201 | } | |
8202 | ||
7162431d | 8203 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f | 8204 | out: |
e6ea44e9 | 8205 | mutex_unlock(&ftrace_lock); |
3d083395 | 8206 | return ret; |
16444a8a | 8207 | } |
8e4e83b2 WX |
8208 | |
8209 | static struct ctl_table ftrace_sysctls[] = { | |
8210 | { | |
8211 | .procname = "ftrace_enabled", | |
8212 | .data = &ftrace_enabled, | |
8213 | .maxlen = sizeof(int), | |
8214 | .mode = 0644, | |
8215 | .proc_handler = ftrace_enable_sysctl, | |
8216 | }, | |
8217 | {} | |
8218 | }; | |
8219 | ||
8220 | static int __init ftrace_sysctl_init(void) | |
8221 | { | |
8222 | register_sysctl_init("kernel", ftrace_sysctls); | |
8223 | return 0; | |
8224 | } | |
8225 | late_initcall(ftrace_sysctl_init); | |
8226 | #endif |