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