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 | |
6912896e | 48 | #define FTRACE_WARN_ON(cond) \ |
0778d9ad SR |
49 | ({ \ |
50 | int ___r = cond; \ | |
51 | if (WARN_ON(___r)) \ | |
6912896e | 52 | ftrace_kill(); \ |
0778d9ad SR |
53 | ___r; \ |
54 | }) | |
6912896e SR |
55 | |
56 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
0778d9ad SR |
57 | ({ \ |
58 | int ___r = cond; \ | |
59 | if (WARN_ON_ONCE(___r)) \ | |
6912896e | 60 | ftrace_kill(); \ |
0778d9ad SR |
61 | ___r; \ |
62 | }) | |
6912896e | 63 | |
8fc0c701 | 64 | /* hash bits for specific function selection */ |
33dc9b12 SR |
65 | #define FTRACE_HASH_DEFAULT_BITS 10 |
66 | #define FTRACE_HASH_MAX_BITS 12 | |
8fc0c701 | 67 | |
f04f24fb | 68 | #ifdef CONFIG_DYNAMIC_FTRACE |
33b7f99c SRRH |
69 | #define INIT_OPS_HASH(opsname) \ |
70 | .func_hash = &opsname.local_hash, \ | |
71 | .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock), | |
f04f24fb | 72 | #else |
33b7f99c | 73 | #define INIT_OPS_HASH(opsname) |
f04f24fb MH |
74 | #endif |
75 | ||
a0572f68 SRV |
76 | enum { |
77 | FTRACE_MODIFY_ENABLE_FL = (1 << 0), | |
78 | FTRACE_MODIFY_MAY_SLEEP_FL = (1 << 1), | |
79 | }; | |
80 | ||
3306fc4a | 81 | struct ftrace_ops ftrace_list_end __read_mostly = { |
2f5f6ad9 | 82 | .func = ftrace_stub, |
395b97a3 | 83 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB, |
33b7f99c | 84 | INIT_OPS_HASH(ftrace_list_end) |
2f5f6ad9 SR |
85 | }; |
86 | ||
4eebcc81 SR |
87 | /* ftrace_enabled is a method to turn ftrace on or off */ |
88 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 89 | static int last_ftrace_enabled; |
b0fc494f | 90 | |
2f5f6ad9 SR |
91 | /* Current function tracing op */ |
92 | struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end; | |
405e1d83 SRRH |
93 | /* What to set function_trace_op to */ |
94 | static struct ftrace_ops *set_function_trace_op; | |
60a7ecf4 | 95 | |
345ddcc8 | 96 | static bool ftrace_pids_enabled(struct ftrace_ops *ops) |
e3eea140 | 97 | { |
345ddcc8 SRRH |
98 | struct trace_array *tr; |
99 | ||
100 | if (!(ops->flags & FTRACE_OPS_FL_PID) || !ops->private) | |
101 | return false; | |
102 | ||
103 | tr = ops->private; | |
104 | ||
105 | return tr->function_pids != NULL; | |
e3eea140 SRRH |
106 | } |
107 | ||
108 | static void ftrace_update_trampoline(struct ftrace_ops *ops); | |
109 | ||
4eebcc81 SR |
110 | /* |
111 | * ftrace_disabled is set when an anomaly is discovered. | |
112 | * ftrace_disabled is much stronger than ftrace_enabled. | |
113 | */ | |
114 | static int ftrace_disabled __read_mostly; | |
115 | ||
3306fc4a | 116 | DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 117 | |
3306fc4a | 118 | struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = &ftrace_list_end; |
16444a8a | 119 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
3306fc4a | 120 | struct ftrace_ops global_ops; |
16444a8a | 121 | |
2f5f6ad9 SR |
122 | #if ARCH_SUPPORTS_FTRACE_OPS |
123 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 124 | struct ftrace_ops *op, struct pt_regs *regs); |
2f5f6ad9 SR |
125 | #else |
126 | /* See comment below, where ftrace_ops_list_func is defined */ | |
127 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip); | |
128 | #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops) | |
129 | #endif | |
b848914c | 130 | |
f04f24fb MH |
131 | static inline void ftrace_ops_init(struct ftrace_ops *ops) |
132 | { | |
133 | #ifdef CONFIG_DYNAMIC_FTRACE | |
134 | if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) { | |
33b7f99c SRRH |
135 | mutex_init(&ops->local_hash.regex_lock); |
136 | ops->func_hash = &ops->local_hash; | |
f04f24fb MH |
137 | ops->flags |= FTRACE_OPS_FL_INITIALIZED; |
138 | } | |
139 | #endif | |
140 | } | |
141 | ||
2f5f6ad9 | 142 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 143 | struct ftrace_ops *op, struct pt_regs *regs) |
df4fc315 | 144 | { |
345ddcc8 SRRH |
145 | struct trace_array *tr = op->private; |
146 | ||
1c5eb448 | 147 | if (tr && this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid)) |
df4fc315 SR |
148 | return; |
149 | ||
e3eea140 | 150 | op->saved_func(ip, parent_ip, op, regs); |
df4fc315 SR |
151 | } |
152 | ||
405e1d83 SRRH |
153 | static void ftrace_sync(struct work_struct *work) |
154 | { | |
155 | /* | |
156 | * This function is just a stub to implement a hard force | |
74401729 | 157 | * of synchronize_rcu(). This requires synchronizing |
405e1d83 SRRH |
158 | * tasks even in userspace and idle. |
159 | * | |
160 | * Yes, function tracing is rude. | |
161 | */ | |
162 | } | |
163 | ||
164 | static void ftrace_sync_ipi(void *data) | |
165 | { | |
166 | /* Probably not needed, but do it anyway */ | |
167 | smp_rmb(); | |
168 | } | |
169 | ||
00ccbf2f SRRH |
170 | static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops) |
171 | { | |
172 | /* | |
ba27f2bc | 173 | * If this is a dynamic, RCU, or per CPU ops, or we force list func, |
00ccbf2f SRRH |
174 | * then it needs to call the list anyway. |
175 | */ | |
b3a88803 PZ |
176 | if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_RCU) || |
177 | FTRACE_FORCE_LIST_FUNC) | |
00ccbf2f SRRH |
178 | return ftrace_ops_list_func; |
179 | ||
180 | return ftrace_ops_get_func(ops); | |
181 | } | |
182 | ||
2b499381 SR |
183 | static void update_ftrace_function(void) |
184 | { | |
185 | ftrace_func_t func; | |
186 | ||
f7aad4e1 SRRH |
187 | /* |
188 | * Prepare the ftrace_ops that the arch callback will use. | |
189 | * If there's only one ftrace_ops registered, the ftrace_ops_list | |
190 | * will point to the ops we want. | |
191 | */ | |
f86f4180 CZ |
192 | set_function_trace_op = rcu_dereference_protected(ftrace_ops_list, |
193 | lockdep_is_held(&ftrace_lock)); | |
f7aad4e1 SRRH |
194 | |
195 | /* If there's no ftrace_ops registered, just call the stub function */ | |
f86f4180 | 196 | if (set_function_trace_op == &ftrace_list_end) { |
f7aad4e1 SRRH |
197 | func = ftrace_stub; |
198 | ||
cdbe61bf SR |
199 | /* |
200 | * If we are at the end of the list and this ops is | |
4740974a SR |
201 | * recursion safe and not dynamic and the arch supports passing ops, |
202 | * then have the mcount trampoline call the function directly. | |
cdbe61bf | 203 | */ |
f86f4180 CZ |
204 | } else if (rcu_dereference_protected(ftrace_ops_list->next, |
205 | lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { | |
00ccbf2f | 206 | func = ftrace_ops_get_list_func(ftrace_ops_list); |
f7aad4e1 | 207 | |
2f5f6ad9 SR |
208 | } else { |
209 | /* Just use the default ftrace_ops */ | |
405e1d83 | 210 | set_function_trace_op = &ftrace_list_end; |
b848914c | 211 | func = ftrace_ops_list_func; |
2f5f6ad9 | 212 | } |
2b499381 | 213 | |
5f8bf2d2 SRRH |
214 | update_function_graph_func(); |
215 | ||
405e1d83 SRRH |
216 | /* If there's no change, then do nothing more here */ |
217 | if (ftrace_trace_function == func) | |
218 | return; | |
219 | ||
220 | /* | |
221 | * If we are using the list function, it doesn't care | |
222 | * about the function_trace_ops. | |
223 | */ | |
224 | if (func == ftrace_ops_list_func) { | |
225 | ftrace_trace_function = func; | |
226 | /* | |
227 | * Don't even bother setting function_trace_ops, | |
228 | * it would be racy to do so anyway. | |
229 | */ | |
230 | return; | |
231 | } | |
232 | ||
233 | #ifndef CONFIG_DYNAMIC_FTRACE | |
234 | /* | |
235 | * For static tracing, we need to be a bit more careful. | |
236 | * The function change takes affect immediately. Thus, | |
237 | * we need to coorditate the setting of the function_trace_ops | |
238 | * with the setting of the ftrace_trace_function. | |
239 | * | |
240 | * Set the function to the list ops, which will call the | |
241 | * function we want, albeit indirectly, but it handles the | |
242 | * ftrace_ops and doesn't depend on function_trace_op. | |
243 | */ | |
244 | ftrace_trace_function = ftrace_ops_list_func; | |
245 | /* | |
246 | * Make sure all CPUs see this. Yes this is slow, but static | |
247 | * tracing is slow and nasty to have enabled. | |
248 | */ | |
249 | schedule_on_each_cpu(ftrace_sync); | |
250 | /* Now all cpus are using the list ops. */ | |
251 | function_trace_op = set_function_trace_op; | |
252 | /* Make sure the function_trace_op is visible on all CPUs */ | |
253 | smp_wmb(); | |
254 | /* Nasty way to force a rmb on all cpus */ | |
255 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
256 | /* OK, we are all set to update the ftrace_trace_function now! */ | |
257 | #endif /* !CONFIG_DYNAMIC_FTRACE */ | |
258 | ||
491d0dcf | 259 | ftrace_trace_function = func; |
491d0dcf SR |
260 | } |
261 | ||
f86f4180 CZ |
262 | static void add_ftrace_ops(struct ftrace_ops __rcu **list, |
263 | struct ftrace_ops *ops) | |
3d083395 | 264 | { |
f86f4180 CZ |
265 | rcu_assign_pointer(ops->next, *list); |
266 | ||
16444a8a | 267 | /* |
b848914c | 268 | * We are entering ops into the list but another |
16444a8a ACM |
269 | * CPU might be walking that list. We need to make sure |
270 | * the ops->next pointer is valid before another CPU sees | |
b848914c | 271 | * the ops pointer included into the list. |
16444a8a | 272 | */ |
2b499381 | 273 | rcu_assign_pointer(*list, ops); |
16444a8a ACM |
274 | } |
275 | ||
f86f4180 CZ |
276 | static int remove_ftrace_ops(struct ftrace_ops __rcu **list, |
277 | struct ftrace_ops *ops) | |
16444a8a | 278 | { |
16444a8a | 279 | struct ftrace_ops **p; |
16444a8a ACM |
280 | |
281 | /* | |
3d083395 SR |
282 | * If we are removing the last function, then simply point |
283 | * to the ftrace_stub. | |
16444a8a | 284 | */ |
f86f4180 CZ |
285 | if (rcu_dereference_protected(*list, |
286 | lockdep_is_held(&ftrace_lock)) == ops && | |
287 | rcu_dereference_protected(ops->next, | |
288 | lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { | |
2b499381 | 289 | *list = &ftrace_list_end; |
e6ea44e9 | 290 | return 0; |
16444a8a ACM |
291 | } |
292 | ||
2b499381 | 293 | for (p = list; *p != &ftrace_list_end; p = &(*p)->next) |
16444a8a ACM |
294 | if (*p == ops) |
295 | break; | |
296 | ||
e6ea44e9 SR |
297 | if (*p != ops) |
298 | return -1; | |
16444a8a ACM |
299 | |
300 | *p = (*p)->next; | |
2b499381 SR |
301 | return 0; |
302 | } | |
16444a8a | 303 | |
f3bea491 SRRH |
304 | static void ftrace_update_trampoline(struct ftrace_ops *ops); |
305 | ||
3306fc4a | 306 | int __register_ftrace_function(struct ftrace_ops *ops) |
2b499381 | 307 | { |
591dffda SRRH |
308 | if (ops->flags & FTRACE_OPS_FL_DELETED) |
309 | return -EINVAL; | |
310 | ||
b848914c SR |
311 | if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) |
312 | return -EBUSY; | |
313 | ||
06aeaaea | 314 | #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
08f6fba5 SR |
315 | /* |
316 | * If the ftrace_ops specifies SAVE_REGS, then it only can be used | |
317 | * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set. | |
318 | * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant. | |
319 | */ | |
320 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS && | |
321 | !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)) | |
322 | return -EINVAL; | |
323 | ||
324 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED) | |
325 | ops->flags |= FTRACE_OPS_FL_SAVE_REGS; | |
326 | #endif | |
7162431d MB |
327 | if (!ftrace_enabled && (ops->flags & FTRACE_OPS_FL_PERMANENT)) |
328 | return -EBUSY; | |
08f6fba5 | 329 | |
cdbe61bf SR |
330 | if (!core_kernel_data((unsigned long)ops)) |
331 | ops->flags |= FTRACE_OPS_FL_DYNAMIC; | |
332 | ||
ba27f2bc | 333 | add_ftrace_ops(&ftrace_ops_list, ops); |
b848914c | 334 | |
e3eea140 SRRH |
335 | /* Always save the function, and reset at unregistering */ |
336 | ops->saved_func = ops->func; | |
337 | ||
345ddcc8 | 338 | if (ftrace_pids_enabled(ops)) |
e3eea140 SRRH |
339 | ops->func = ftrace_pid_func; |
340 | ||
f3bea491 SRRH |
341 | ftrace_update_trampoline(ops); |
342 | ||
2b499381 SR |
343 | if (ftrace_enabled) |
344 | update_ftrace_function(); | |
345 | ||
346 | return 0; | |
347 | } | |
348 | ||
3306fc4a | 349 | int __unregister_ftrace_function(struct ftrace_ops *ops) |
2b499381 SR |
350 | { |
351 | int ret; | |
352 | ||
b848914c SR |
353 | if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) |
354 | return -EBUSY; | |
355 | ||
ba27f2bc | 356 | ret = remove_ftrace_ops(&ftrace_ops_list, ops); |
b848914c | 357 | |
2b499381 SR |
358 | if (ret < 0) |
359 | return ret; | |
b848914c | 360 | |
491d0dcf SR |
361 | if (ftrace_enabled) |
362 | update_ftrace_function(); | |
16444a8a | 363 | |
e3eea140 SRRH |
364 | ops->func = ops->saved_func; |
365 | ||
e6ea44e9 | 366 | return 0; |
3d083395 SR |
367 | } |
368 | ||
df4fc315 SR |
369 | static void ftrace_update_pid_func(void) |
370 | { | |
e3eea140 SRRH |
371 | struct ftrace_ops *op; |
372 | ||
491d0dcf | 373 | /* Only do something if we are tracing something */ |
df4fc315 | 374 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 375 | return; |
df4fc315 | 376 | |
e3eea140 SRRH |
377 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
378 | if (op->flags & FTRACE_OPS_FL_PID) { | |
345ddcc8 SRRH |
379 | op->func = ftrace_pids_enabled(op) ? |
380 | ftrace_pid_func : op->saved_func; | |
e3eea140 SRRH |
381 | ftrace_update_trampoline(op); |
382 | } | |
383 | } while_for_each_ftrace_op(op); | |
384 | ||
491d0dcf | 385 | update_ftrace_function(); |
df4fc315 SR |
386 | } |
387 | ||
493762fc SR |
388 | #ifdef CONFIG_FUNCTION_PROFILER |
389 | struct ftrace_profile { | |
390 | struct hlist_node node; | |
391 | unsigned long ip; | |
392 | unsigned long counter; | |
0706f1c4 SR |
393 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
394 | unsigned long long time; | |
e330b3bc | 395 | unsigned long long time_squared; |
0706f1c4 | 396 | #endif |
8fc0c701 SR |
397 | }; |
398 | ||
493762fc SR |
399 | struct ftrace_profile_page { |
400 | struct ftrace_profile_page *next; | |
401 | unsigned long index; | |
402 | struct ftrace_profile records[]; | |
d61f82d0 SR |
403 | }; |
404 | ||
cafb168a SR |
405 | struct ftrace_profile_stat { |
406 | atomic_t disabled; | |
407 | struct hlist_head *hash; | |
408 | struct ftrace_profile_page *pages; | |
409 | struct ftrace_profile_page *start; | |
410 | struct tracer_stat stat; | |
411 | }; | |
412 | ||
493762fc SR |
413 | #define PROFILE_RECORDS_SIZE \ |
414 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 415 | |
493762fc SR |
416 | #define PROFILES_PER_PAGE \ |
417 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 418 | |
fb9fb015 SR |
419 | static int ftrace_profile_enabled __read_mostly; |
420 | ||
421 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
422 | static DEFINE_MUTEX(ftrace_profile_lock); |
423 | ||
cafb168a | 424 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc | 425 | |
20079ebe NK |
426 | #define FTRACE_PROFILE_HASH_BITS 10 |
427 | #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS) | |
493762fc | 428 | |
bac429f0 SR |
429 | static void * |
430 | function_stat_next(void *v, int idx) | |
431 | { | |
493762fc SR |
432 | struct ftrace_profile *rec = v; |
433 | struct ftrace_profile_page *pg; | |
bac429f0 | 434 | |
493762fc | 435 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
436 | |
437 | again: | |
0296e425 LZ |
438 | if (idx != 0) |
439 | rec++; | |
440 | ||
bac429f0 SR |
441 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
442 | pg = pg->next; | |
443 | if (!pg) | |
444 | return NULL; | |
445 | rec = &pg->records[0]; | |
493762fc SR |
446 | if (!rec->counter) |
447 | goto again; | |
bac429f0 SR |
448 | } |
449 | ||
bac429f0 SR |
450 | return rec; |
451 | } | |
452 | ||
453 | static void *function_stat_start(struct tracer_stat *trace) | |
454 | { | |
cafb168a SR |
455 | struct ftrace_profile_stat *stat = |
456 | container_of(trace, struct ftrace_profile_stat, stat); | |
457 | ||
458 | if (!stat || !stat->start) | |
459 | return NULL; | |
460 | ||
461 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
462 | } |
463 | ||
0706f1c4 SR |
464 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
465 | /* function graph compares on total time */ | |
80042c8f | 466 | static int function_stat_cmp(const void *p1, const void *p2) |
0706f1c4 | 467 | { |
80042c8f AS |
468 | const struct ftrace_profile *a = p1; |
469 | const struct ftrace_profile *b = p2; | |
0706f1c4 SR |
470 | |
471 | if (a->time < b->time) | |
472 | return -1; | |
473 | if (a->time > b->time) | |
474 | return 1; | |
475 | else | |
476 | return 0; | |
477 | } | |
478 | #else | |
479 | /* not function graph compares against hits */ | |
80042c8f | 480 | static int function_stat_cmp(const void *p1, const void *p2) |
bac429f0 | 481 | { |
80042c8f AS |
482 | const struct ftrace_profile *a = p1; |
483 | const struct ftrace_profile *b = p2; | |
bac429f0 SR |
484 | |
485 | if (a->counter < b->counter) | |
486 | return -1; | |
487 | if (a->counter > b->counter) | |
488 | return 1; | |
489 | else | |
490 | return 0; | |
491 | } | |
0706f1c4 | 492 | #endif |
bac429f0 SR |
493 | |
494 | static int function_stat_headers(struct seq_file *m) | |
495 | { | |
0706f1c4 | 496 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
fa6f0cc7 RV |
497 | seq_puts(m, " Function " |
498 | "Hit Time Avg s^2\n" | |
499 | " -------- " | |
500 | "--- ---- --- ---\n"); | |
0706f1c4 | 501 | #else |
fa6f0cc7 RV |
502 | seq_puts(m, " Function Hit\n" |
503 | " -------- ---\n"); | |
0706f1c4 | 504 | #endif |
bac429f0 SR |
505 | return 0; |
506 | } | |
507 | ||
508 | static int function_stat_show(struct seq_file *m, void *v) | |
509 | { | |
493762fc | 510 | struct ftrace_profile *rec = v; |
bac429f0 | 511 | char str[KSYM_SYMBOL_LEN]; |
3aaba20f | 512 | int ret = 0; |
0706f1c4 | 513 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
514 | static struct trace_seq s; |
515 | unsigned long long avg; | |
e330b3bc | 516 | unsigned long long stddev; |
0706f1c4 | 517 | #endif |
3aaba20f LZ |
518 | mutex_lock(&ftrace_profile_lock); |
519 | ||
520 | /* we raced with function_profile_reset() */ | |
521 | if (unlikely(rec->counter == 0)) { | |
522 | ret = -EBUSY; | |
523 | goto out; | |
524 | } | |
bac429f0 | 525 | |
8e436ca0 | 526 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e31f7939 | 527 | avg = div64_ul(rec->time, rec->counter); |
8e436ca0 UT |
528 | if (tracing_thresh && (avg < tracing_thresh)) |
529 | goto out; | |
530 | #endif | |
531 | ||
bac429f0 | 532 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
0706f1c4 SR |
533 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
534 | ||
535 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
fa6f0cc7 | 536 | seq_puts(m, " "); |
34886c8b | 537 | |
e330b3bc CD |
538 | /* Sample standard deviation (s^2) */ |
539 | if (rec->counter <= 1) | |
540 | stddev = 0; | |
541 | else { | |
52d85d76 JL |
542 | /* |
543 | * Apply Welford's method: | |
544 | * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2) | |
545 | */ | |
546 | stddev = rec->counter * rec->time_squared - | |
547 | rec->time * rec->time; | |
548 | ||
e330b3bc CD |
549 | /* |
550 | * Divide only 1000 for ns^2 -> us^2 conversion. | |
551 | * trace_print_graph_duration will divide 1000 again. | |
552 | */ | |
e31f7939 WY |
553 | stddev = div64_ul(stddev, |
554 | rec->counter * (rec->counter - 1) * 1000); | |
e330b3bc CD |
555 | } |
556 | ||
34886c8b SR |
557 | trace_seq_init(&s); |
558 | trace_print_graph_duration(rec->time, &s); | |
559 | trace_seq_puts(&s, " "); | |
560 | trace_print_graph_duration(avg, &s); | |
e330b3bc CD |
561 | trace_seq_puts(&s, " "); |
562 | trace_print_graph_duration(stddev, &s); | |
0706f1c4 | 563 | trace_print_seq(m, &s); |
0706f1c4 SR |
564 | #endif |
565 | seq_putc(m, '\n'); | |
3aaba20f LZ |
566 | out: |
567 | mutex_unlock(&ftrace_profile_lock); | |
bac429f0 | 568 | |
3aaba20f | 569 | return ret; |
bac429f0 SR |
570 | } |
571 | ||
cafb168a | 572 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 573 | { |
493762fc | 574 | struct ftrace_profile_page *pg; |
bac429f0 | 575 | |
cafb168a | 576 | pg = stat->pages = stat->start; |
bac429f0 | 577 | |
493762fc SR |
578 | while (pg) { |
579 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
580 | pg->index = 0; | |
581 | pg = pg->next; | |
bac429f0 SR |
582 | } |
583 | ||
cafb168a | 584 | memset(stat->hash, 0, |
493762fc SR |
585 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
586 | } | |
bac429f0 | 587 | |
cafb168a | 588 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
589 | { |
590 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
591 | int functions; |
592 | int pages; | |
493762fc | 593 | int i; |
bac429f0 | 594 | |
493762fc | 595 | /* If we already allocated, do nothing */ |
cafb168a | 596 | if (stat->pages) |
493762fc | 597 | return 0; |
bac429f0 | 598 | |
cafb168a SR |
599 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
600 | if (!stat->pages) | |
493762fc | 601 | return -ENOMEM; |
bac429f0 | 602 | |
318e0a73 SR |
603 | #ifdef CONFIG_DYNAMIC_FTRACE |
604 | functions = ftrace_update_tot_cnt; | |
605 | #else | |
606 | /* | |
607 | * We do not know the number of functions that exist because | |
608 | * dynamic tracing is what counts them. With past experience | |
609 | * we have around 20K functions. That should be more than enough. | |
610 | * It is highly unlikely we will execute every function in | |
611 | * the kernel. | |
612 | */ | |
613 | functions = 20000; | |
614 | #endif | |
615 | ||
cafb168a | 616 | pg = stat->start = stat->pages; |
bac429f0 | 617 | |
318e0a73 SR |
618 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
619 | ||
39e30cd1 | 620 | for (i = 1; i < pages; i++) { |
493762fc | 621 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 622 | if (!pg->next) |
318e0a73 | 623 | goto out_free; |
493762fc SR |
624 | pg = pg->next; |
625 | } | |
626 | ||
627 | return 0; | |
318e0a73 SR |
628 | |
629 | out_free: | |
630 | pg = stat->start; | |
631 | while (pg) { | |
632 | unsigned long tmp = (unsigned long)pg; | |
633 | ||
634 | pg = pg->next; | |
635 | free_page(tmp); | |
636 | } | |
637 | ||
318e0a73 SR |
638 | stat->pages = NULL; |
639 | stat->start = NULL; | |
640 | ||
641 | return -ENOMEM; | |
bac429f0 SR |
642 | } |
643 | ||
cafb168a | 644 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 645 | { |
cafb168a | 646 | struct ftrace_profile_stat *stat; |
493762fc | 647 | int size; |
bac429f0 | 648 | |
cafb168a SR |
649 | stat = &per_cpu(ftrace_profile_stats, cpu); |
650 | ||
651 | if (stat->hash) { | |
493762fc | 652 | /* If the profile is already created, simply reset it */ |
cafb168a | 653 | ftrace_profile_reset(stat); |
493762fc SR |
654 | return 0; |
655 | } | |
bac429f0 | 656 | |
493762fc SR |
657 | /* |
658 | * We are profiling all functions, but usually only a few thousand | |
659 | * functions are hit. We'll make a hash of 1024 items. | |
660 | */ | |
661 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 662 | |
6396bb22 | 663 | stat->hash = kcalloc(size, sizeof(struct hlist_head), GFP_KERNEL); |
493762fc | 664 | |
cafb168a | 665 | if (!stat->hash) |
493762fc SR |
666 | return -ENOMEM; |
667 | ||
318e0a73 | 668 | /* Preallocate the function profiling pages */ |
cafb168a SR |
669 | if (ftrace_profile_pages_init(stat) < 0) { |
670 | kfree(stat->hash); | |
671 | stat->hash = NULL; | |
493762fc SR |
672 | return -ENOMEM; |
673 | } | |
674 | ||
675 | return 0; | |
bac429f0 SR |
676 | } |
677 | ||
cafb168a SR |
678 | static int ftrace_profile_init(void) |
679 | { | |
680 | int cpu; | |
681 | int ret = 0; | |
682 | ||
c4602c1c | 683 | for_each_possible_cpu(cpu) { |
cafb168a SR |
684 | ret = ftrace_profile_init_cpu(cpu); |
685 | if (ret) | |
686 | break; | |
687 | } | |
688 | ||
689 | return ret; | |
690 | } | |
691 | ||
493762fc | 692 | /* interrupts must be disabled */ |
cafb168a SR |
693 | static struct ftrace_profile * |
694 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 695 | { |
493762fc | 696 | struct ftrace_profile *rec; |
bac429f0 | 697 | struct hlist_head *hhd; |
bac429f0 SR |
698 | unsigned long key; |
699 | ||
20079ebe | 700 | key = hash_long(ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 701 | hhd = &stat->hash[key]; |
bac429f0 SR |
702 | |
703 | if (hlist_empty(hhd)) | |
704 | return NULL; | |
705 | ||
1bb539ca | 706 | hlist_for_each_entry_rcu_notrace(rec, hhd, node) { |
bac429f0 | 707 | if (rec->ip == ip) |
493762fc SR |
708 | return rec; |
709 | } | |
710 | ||
711 | return NULL; | |
712 | } | |
713 | ||
cafb168a SR |
714 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
715 | struct ftrace_profile *rec) | |
493762fc SR |
716 | { |
717 | unsigned long key; | |
718 | ||
20079ebe | 719 | key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 720 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
721 | } |
722 | ||
318e0a73 SR |
723 | /* |
724 | * The memory is already allocated, this simply finds a new record to use. | |
725 | */ | |
493762fc | 726 | static struct ftrace_profile * |
318e0a73 | 727 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
728 | { |
729 | struct ftrace_profile *rec = NULL; | |
730 | ||
318e0a73 | 731 | /* prevent recursion (from NMIs) */ |
cafb168a | 732 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
733 | goto out; |
734 | ||
493762fc | 735 | /* |
318e0a73 SR |
736 | * Try to find the function again since an NMI |
737 | * could have added it | |
493762fc | 738 | */ |
cafb168a | 739 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 740 | if (rec) |
cafb168a | 741 | goto out; |
493762fc | 742 | |
cafb168a SR |
743 | if (stat->pages->index == PROFILES_PER_PAGE) { |
744 | if (!stat->pages->next) | |
745 | goto out; | |
746 | stat->pages = stat->pages->next; | |
bac429f0 | 747 | } |
493762fc | 748 | |
cafb168a | 749 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 750 | rec->ip = ip; |
cafb168a | 751 | ftrace_add_profile(stat, rec); |
493762fc | 752 | |
bac429f0 | 753 | out: |
cafb168a | 754 | atomic_dec(&stat->disabled); |
bac429f0 SR |
755 | |
756 | return rec; | |
757 | } | |
758 | ||
759 | static void | |
2f5f6ad9 | 760 | function_profile_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 761 | struct ftrace_ops *ops, struct pt_regs *regs) |
bac429f0 | 762 | { |
cafb168a | 763 | struct ftrace_profile_stat *stat; |
493762fc | 764 | struct ftrace_profile *rec; |
bac429f0 SR |
765 | unsigned long flags; |
766 | ||
767 | if (!ftrace_profile_enabled) | |
768 | return; | |
769 | ||
770 | local_irq_save(flags); | |
cafb168a | 771 | |
bdffd893 | 772 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 773 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
774 | goto out; |
775 | ||
776 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 777 | if (!rec) { |
318e0a73 | 778 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
779 | if (!rec) |
780 | goto out; | |
781 | } | |
bac429f0 SR |
782 | |
783 | rec->counter++; | |
784 | out: | |
785 | local_irq_restore(flags); | |
786 | } | |
787 | ||
0706f1c4 | 788 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e73e679f SRV |
789 | static bool fgraph_graph_time = true; |
790 | ||
791 | void ftrace_graph_graph_time_control(bool enable) | |
792 | { | |
793 | fgraph_graph_time = enable; | |
794 | } | |
795 | ||
0706f1c4 SR |
796 | static int profile_graph_entry(struct ftrace_graph_ent *trace) |
797 | { | |
b0e21a61 | 798 | struct ftrace_ret_stack *ret_stack; |
8861dd30 | 799 | |
a1e2e31d | 800 | function_profile_call(trace->func, 0, NULL, NULL); |
8861dd30 | 801 | |
a8f0f9e4 SRV |
802 | /* If function graph is shutting down, ret_stack can be NULL */ |
803 | if (!current->ret_stack) | |
804 | return 0; | |
805 | ||
b0e21a61 SRV |
806 | ret_stack = ftrace_graph_get_ret_stack(current, 0); |
807 | if (ret_stack) | |
808 | ret_stack->subtime = 0; | |
8861dd30 | 809 | |
0706f1c4 SR |
810 | return 1; |
811 | } | |
812 | ||
813 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
814 | { | |
b0e21a61 | 815 | struct ftrace_ret_stack *ret_stack; |
cafb168a | 816 | struct ftrace_profile_stat *stat; |
a2a16d6a | 817 | unsigned long long calltime; |
0706f1c4 | 818 | struct ftrace_profile *rec; |
cafb168a | 819 | unsigned long flags; |
0706f1c4 SR |
820 | |
821 | local_irq_save(flags); | |
bdffd893 | 822 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 823 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
824 | goto out; |
825 | ||
37e44bc5 SR |
826 | /* If the calltime was zero'd ignore it */ |
827 | if (!trace->calltime) | |
828 | goto out; | |
829 | ||
a2a16d6a SR |
830 | calltime = trace->rettime - trace->calltime; |
831 | ||
55577204 | 832 | if (!fgraph_graph_time) { |
a2a16d6a SR |
833 | |
834 | /* Append this call time to the parent time to subtract */ | |
b0e21a61 SRV |
835 | ret_stack = ftrace_graph_get_ret_stack(current, 1); |
836 | if (ret_stack) | |
837 | ret_stack->subtime += calltime; | |
a2a16d6a | 838 | |
b0e21a61 SRV |
839 | ret_stack = ftrace_graph_get_ret_stack(current, 0); |
840 | if (ret_stack && ret_stack->subtime < calltime) | |
841 | calltime -= ret_stack->subtime; | |
a2a16d6a SR |
842 | else |
843 | calltime = 0; | |
844 | } | |
845 | ||
cafb168a | 846 | rec = ftrace_find_profiled_func(stat, trace->func); |
e330b3bc | 847 | if (rec) { |
a2a16d6a | 848 | rec->time += calltime; |
e330b3bc CD |
849 | rec->time_squared += calltime * calltime; |
850 | } | |
a2a16d6a | 851 | |
cafb168a | 852 | out: |
0706f1c4 SR |
853 | local_irq_restore(flags); |
854 | } | |
855 | ||
688f7089 SRV |
856 | static struct fgraph_ops fprofiler_ops = { |
857 | .entryfunc = &profile_graph_entry, | |
858 | .retfunc = &profile_graph_return, | |
859 | }; | |
860 | ||
0706f1c4 SR |
861 | static int register_ftrace_profiler(void) |
862 | { | |
688f7089 | 863 | return register_ftrace_graph(&fprofiler_ops); |
0706f1c4 SR |
864 | } |
865 | ||
866 | static void unregister_ftrace_profiler(void) | |
867 | { | |
688f7089 | 868 | unregister_ftrace_graph(&fprofiler_ops); |
0706f1c4 SR |
869 | } |
870 | #else | |
bd38c0e6 | 871 | static struct ftrace_ops ftrace_profile_ops __read_mostly = { |
fb9fb015 | 872 | .func = function_profile_call, |
f04f24fb | 873 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, |
33b7f99c | 874 | INIT_OPS_HASH(ftrace_profile_ops) |
bac429f0 SR |
875 | }; |
876 | ||
0706f1c4 SR |
877 | static int register_ftrace_profiler(void) |
878 | { | |
879 | return register_ftrace_function(&ftrace_profile_ops); | |
880 | } | |
881 | ||
882 | static void unregister_ftrace_profiler(void) | |
883 | { | |
884 | unregister_ftrace_function(&ftrace_profile_ops); | |
885 | } | |
886 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
887 | ||
bac429f0 SR |
888 | static ssize_t |
889 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
890 | size_t cnt, loff_t *ppos) | |
891 | { | |
892 | unsigned long val; | |
bac429f0 SR |
893 | int ret; |
894 | ||
22fe9b54 PH |
895 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
896 | if (ret) | |
bac429f0 SR |
897 | return ret; |
898 | ||
899 | val = !!val; | |
900 | ||
901 | mutex_lock(&ftrace_profile_lock); | |
902 | if (ftrace_profile_enabled ^ val) { | |
903 | if (val) { | |
493762fc SR |
904 | ret = ftrace_profile_init(); |
905 | if (ret < 0) { | |
906 | cnt = ret; | |
907 | goto out; | |
908 | } | |
909 | ||
0706f1c4 SR |
910 | ret = register_ftrace_profiler(); |
911 | if (ret < 0) { | |
912 | cnt = ret; | |
913 | goto out; | |
914 | } | |
bac429f0 SR |
915 | ftrace_profile_enabled = 1; |
916 | } else { | |
917 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
918 | /* |
919 | * unregister_ftrace_profiler calls stop_machine | |
74401729 | 920 | * so this acts like an synchronize_rcu. |
0f6ce3de | 921 | */ |
0706f1c4 | 922 | unregister_ftrace_profiler(); |
bac429f0 SR |
923 | } |
924 | } | |
493762fc | 925 | out: |
bac429f0 SR |
926 | mutex_unlock(&ftrace_profile_lock); |
927 | ||
cf8517cf | 928 | *ppos += cnt; |
bac429f0 SR |
929 | |
930 | return cnt; | |
931 | } | |
932 | ||
493762fc SR |
933 | static ssize_t |
934 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
935 | size_t cnt, loff_t *ppos) | |
936 | { | |
fb9fb015 | 937 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
938 | int r; |
939 | ||
940 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
941 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
942 | } | |
943 | ||
bac429f0 SR |
944 | static const struct file_operations ftrace_profile_fops = { |
945 | .open = tracing_open_generic, | |
946 | .read = ftrace_profile_read, | |
947 | .write = ftrace_profile_write, | |
6038f373 | 948 | .llseek = default_llseek, |
bac429f0 SR |
949 | }; |
950 | ||
cafb168a SR |
951 | /* used to initialize the real stat files */ |
952 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
953 | .name = "functions", |
954 | .stat_start = function_stat_start, | |
955 | .stat_next = function_stat_next, | |
956 | .stat_cmp = function_stat_cmp, | |
957 | .stat_headers = function_stat_headers, | |
958 | .stat_show = function_stat_show | |
cafb168a SR |
959 | }; |
960 | ||
8434dc93 | 961 | static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
bac429f0 | 962 | { |
cafb168a | 963 | struct ftrace_profile_stat *stat; |
bac429f0 | 964 | struct dentry *entry; |
cafb168a | 965 | char *name; |
bac429f0 | 966 | int ret; |
cafb168a SR |
967 | int cpu; |
968 | ||
969 | for_each_possible_cpu(cpu) { | |
970 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
971 | ||
6363c6b5 | 972 | name = kasprintf(GFP_KERNEL, "function%d", cpu); |
cafb168a SR |
973 | if (!name) { |
974 | /* | |
975 | * The files created are permanent, if something happens | |
976 | * we still do not free memory. | |
977 | */ | |
cafb168a SR |
978 | WARN(1, |
979 | "Could not allocate stat file for cpu %d\n", | |
980 | cpu); | |
981 | return; | |
982 | } | |
983 | stat->stat = function_stats; | |
cafb168a SR |
984 | stat->stat.name = name; |
985 | ret = register_stat_tracer(&stat->stat); | |
986 | if (ret) { | |
987 | WARN(1, | |
988 | "Could not register function stat for cpu %d\n", | |
989 | cpu); | |
990 | kfree(name); | |
991 | return; | |
992 | } | |
bac429f0 SR |
993 | } |
994 | ||
8434dc93 | 995 | entry = tracefs_create_file("function_profile_enabled", 0644, |
bac429f0 SR |
996 | d_tracer, NULL, &ftrace_profile_fops); |
997 | if (!entry) | |
a395d6a7 | 998 | pr_warn("Could not create tracefs 'function_profile_enabled' entry\n"); |
bac429f0 SR |
999 | } |
1000 | ||
bac429f0 | 1001 | #else /* CONFIG_FUNCTION_PROFILER */ |
8434dc93 | 1002 | static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
bac429f0 SR |
1003 | { |
1004 | } | |
bac429f0 SR |
1005 | #endif /* CONFIG_FUNCTION_PROFILER */ |
1006 | ||
493762fc SR |
1007 | #ifdef CONFIG_DYNAMIC_FTRACE |
1008 | ||
79922b80 SRRH |
1009 | static struct ftrace_ops *removed_ops; |
1010 | ||
e1effa01 SRRH |
1011 | /* |
1012 | * Set when doing a global update, like enabling all recs or disabling them. | |
1013 | * It is not set when just updating a single ftrace_ops. | |
1014 | */ | |
1015 | static bool update_all_ops; | |
1016 | ||
493762fc SR |
1017 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
1018 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
1019 | #endif | |
1020 | ||
7b60f3d8 SRV |
1021 | struct ftrace_func_probe { |
1022 | struct ftrace_probe_ops *probe_ops; | |
1023 | struct ftrace_ops ops; | |
1024 | struct trace_array *tr; | |
1025 | struct list_head list; | |
6e444319 | 1026 | void *data; |
7b60f3d8 SRV |
1027 | int ref; |
1028 | }; | |
1029 | ||
33dc9b12 SR |
1030 | /* |
1031 | * We make these constant because no one should touch them, | |
1032 | * but they are used as the default "empty hash", to avoid allocating | |
1033 | * it all the time. These are in a read only section such that if | |
1034 | * anyone does try to modify it, it will cause an exception. | |
1035 | */ | |
1036 | static const struct hlist_head empty_buckets[1]; | |
1037 | static const struct ftrace_hash empty_hash = { | |
1038 | .buckets = (struct hlist_head *)empty_buckets, | |
1cf41dd7 | 1039 | }; |
33dc9b12 | 1040 | #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash) |
493762fc | 1041 | |
3306fc4a | 1042 | struct ftrace_ops global_ops = { |
33b7f99c SRRH |
1043 | .func = ftrace_stub, |
1044 | .local_hash.notrace_hash = EMPTY_HASH, | |
1045 | .local_hash.filter_hash = EMPTY_HASH, | |
1046 | INIT_OPS_HASH(global_ops) | |
1047 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | | |
e3eea140 SRRH |
1048 | FTRACE_OPS_FL_INITIALIZED | |
1049 | FTRACE_OPS_FL_PID, | |
f45948e8 SR |
1050 | }; |
1051 | ||
aec0be2d | 1052 | /* |
6be7fa3c | 1053 | * Used by the stack undwinder to know about dynamic ftrace trampolines. |
aec0be2d | 1054 | */ |
6be7fa3c | 1055 | struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr) |
aec0be2d | 1056 | { |
6be7fa3c | 1057 | struct ftrace_ops *op = NULL; |
aec0be2d SRRH |
1058 | |
1059 | /* | |
1060 | * Some of the ops may be dynamically allocated, | |
74401729 | 1061 | * they are freed after a synchronize_rcu(). |
aec0be2d SRRH |
1062 | */ |
1063 | preempt_disable_notrace(); | |
1064 | ||
1065 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1066 | /* | |
1067 | * This is to check for dynamically allocated trampolines. | |
1068 | * Trampolines that are in kernel text will have | |
1069 | * core_kernel_text() return true. | |
1070 | */ | |
1071 | if (op->trampoline && op->trampoline_size) | |
1072 | if (addr >= op->trampoline && | |
1073 | addr < op->trampoline + op->trampoline_size) { | |
6be7fa3c SRV |
1074 | preempt_enable_notrace(); |
1075 | return op; | |
aec0be2d SRRH |
1076 | } |
1077 | } while_for_each_ftrace_op(op); | |
aec0be2d SRRH |
1078 | preempt_enable_notrace(); |
1079 | ||
6be7fa3c SRV |
1080 | return NULL; |
1081 | } | |
1082 | ||
1083 | /* | |
1084 | * This is used by __kernel_text_address() to return true if the | |
1085 | * address is on a dynamically allocated trampoline that would | |
1086 | * not return true for either core_kernel_text() or | |
1087 | * is_module_text_address(). | |
1088 | */ | |
1089 | bool is_ftrace_trampoline(unsigned long addr) | |
1090 | { | |
1091 | return ftrace_ops_trampoline(addr) != NULL; | |
aec0be2d SRRH |
1092 | } |
1093 | ||
493762fc SR |
1094 | struct ftrace_page { |
1095 | struct ftrace_page *next; | |
a7900875 | 1096 | struct dyn_ftrace *records; |
493762fc | 1097 | int index; |
a7900875 | 1098 | int size; |
493762fc SR |
1099 | }; |
1100 | ||
a7900875 SR |
1101 | #define ENTRY_SIZE sizeof(struct dyn_ftrace) |
1102 | #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE) | |
493762fc | 1103 | |
493762fc SR |
1104 | static struct ftrace_page *ftrace_pages_start; |
1105 | static struct ftrace_page *ftrace_pages; | |
1106 | ||
2b0cce0e SRV |
1107 | static __always_inline unsigned long |
1108 | ftrace_hash_key(struct ftrace_hash *hash, unsigned long ip) | |
1109 | { | |
1110 | if (hash->size_bits > 0) | |
1111 | return hash_long(ip, hash->size_bits); | |
1112 | ||
1113 | return 0; | |
1114 | } | |
1115 | ||
2b2c279c SRV |
1116 | /* Only use this function if ftrace_hash_empty() has already been tested */ |
1117 | static __always_inline struct ftrace_func_entry * | |
1118 | __ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
b448c4e3 SR |
1119 | { |
1120 | unsigned long key; | |
1121 | struct ftrace_func_entry *entry; | |
1122 | struct hlist_head *hhd; | |
b448c4e3 | 1123 | |
2b0cce0e | 1124 | key = ftrace_hash_key(hash, ip); |
b448c4e3 SR |
1125 | hhd = &hash->buckets[key]; |
1126 | ||
1bb539ca | 1127 | hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) { |
b448c4e3 SR |
1128 | if (entry->ip == ip) |
1129 | return entry; | |
1130 | } | |
1131 | return NULL; | |
1132 | } | |
1133 | ||
2b2c279c SRV |
1134 | /** |
1135 | * ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash | |
1136 | * @hash: The hash to look at | |
1137 | * @ip: The instruction pointer to test | |
1138 | * | |
1139 | * Search a given @hash to see if a given instruction pointer (@ip) | |
1140 | * exists in it. | |
1141 | * | |
1142 | * Returns the entry that holds the @ip if found. NULL otherwise. | |
1143 | */ | |
1144 | struct ftrace_func_entry * | |
1145 | ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
1146 | { | |
1147 | if (ftrace_hash_empty(hash)) | |
1148 | return NULL; | |
1149 | ||
1150 | return __ftrace_lookup_ip(hash, ip); | |
1151 | } | |
1152 | ||
33dc9b12 SR |
1153 | static void __add_hash_entry(struct ftrace_hash *hash, |
1154 | struct ftrace_func_entry *entry) | |
b448c4e3 | 1155 | { |
b448c4e3 SR |
1156 | struct hlist_head *hhd; |
1157 | unsigned long key; | |
1158 | ||
2b0cce0e | 1159 | key = ftrace_hash_key(hash, entry->ip); |
b448c4e3 SR |
1160 | hhd = &hash->buckets[key]; |
1161 | hlist_add_head(&entry->hlist, hhd); | |
1162 | hash->count++; | |
33dc9b12 SR |
1163 | } |
1164 | ||
1165 | static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip) | |
1166 | { | |
1167 | struct ftrace_func_entry *entry; | |
1168 | ||
1169 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1170 | if (!entry) | |
1171 | return -ENOMEM; | |
1172 | ||
1173 | entry->ip = ip; | |
1174 | __add_hash_entry(hash, entry); | |
b448c4e3 SR |
1175 | |
1176 | return 0; | |
1177 | } | |
1178 | ||
1179 | static void | |
33dc9b12 | 1180 | free_hash_entry(struct ftrace_hash *hash, |
b448c4e3 SR |
1181 | struct ftrace_func_entry *entry) |
1182 | { | |
1183 | hlist_del(&entry->hlist); | |
1184 | kfree(entry); | |
1185 | hash->count--; | |
1186 | } | |
1187 | ||
33dc9b12 SR |
1188 | static void |
1189 | remove_hash_entry(struct ftrace_hash *hash, | |
1190 | struct ftrace_func_entry *entry) | |
1191 | { | |
eee8ded1 | 1192 | hlist_del_rcu(&entry->hlist); |
33dc9b12 SR |
1193 | hash->count--; |
1194 | } | |
1195 | ||
b448c4e3 SR |
1196 | static void ftrace_hash_clear(struct ftrace_hash *hash) |
1197 | { | |
1198 | struct hlist_head *hhd; | |
b67bfe0d | 1199 | struct hlist_node *tn; |
b448c4e3 SR |
1200 | struct ftrace_func_entry *entry; |
1201 | int size = 1 << hash->size_bits; | |
1202 | int i; | |
1203 | ||
33dc9b12 SR |
1204 | if (!hash->count) |
1205 | return; | |
1206 | ||
b448c4e3 SR |
1207 | for (i = 0; i < size; i++) { |
1208 | hhd = &hash->buckets[i]; | |
b67bfe0d | 1209 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) |
33dc9b12 | 1210 | free_hash_entry(hash, entry); |
b448c4e3 SR |
1211 | } |
1212 | FTRACE_WARN_ON(hash->count); | |
1213 | } | |
1214 | ||
673feb9d SRV |
1215 | static void free_ftrace_mod(struct ftrace_mod_load *ftrace_mod) |
1216 | { | |
1217 | list_del(&ftrace_mod->list); | |
1218 | kfree(ftrace_mod->module); | |
1219 | kfree(ftrace_mod->func); | |
1220 | kfree(ftrace_mod); | |
1221 | } | |
1222 | ||
1223 | static void clear_ftrace_mod_list(struct list_head *head) | |
1224 | { | |
1225 | struct ftrace_mod_load *p, *n; | |
1226 | ||
1227 | /* stack tracer isn't supported yet */ | |
1228 | if (!head) | |
1229 | return; | |
1230 | ||
1231 | mutex_lock(&ftrace_lock); | |
1232 | list_for_each_entry_safe(p, n, head, list) | |
1233 | free_ftrace_mod(p); | |
1234 | mutex_unlock(&ftrace_lock); | |
1235 | } | |
1236 | ||
33dc9b12 SR |
1237 | static void free_ftrace_hash(struct ftrace_hash *hash) |
1238 | { | |
1239 | if (!hash || hash == EMPTY_HASH) | |
1240 | return; | |
1241 | ftrace_hash_clear(hash); | |
1242 | kfree(hash->buckets); | |
1243 | kfree(hash); | |
1244 | } | |
1245 | ||
07fd5515 SR |
1246 | static void __free_ftrace_hash_rcu(struct rcu_head *rcu) |
1247 | { | |
1248 | struct ftrace_hash *hash; | |
1249 | ||
1250 | hash = container_of(rcu, struct ftrace_hash, rcu); | |
1251 | free_ftrace_hash(hash); | |
1252 | } | |
1253 | ||
1254 | static void free_ftrace_hash_rcu(struct ftrace_hash *hash) | |
1255 | { | |
1256 | if (!hash || hash == EMPTY_HASH) | |
1257 | return; | |
74401729 | 1258 | call_rcu(&hash->rcu, __free_ftrace_hash_rcu); |
07fd5515 SR |
1259 | } |
1260 | ||
5500fa51 JO |
1261 | void ftrace_free_filter(struct ftrace_ops *ops) |
1262 | { | |
f04f24fb | 1263 | ftrace_ops_init(ops); |
33b7f99c SRRH |
1264 | free_ftrace_hash(ops->func_hash->filter_hash); |
1265 | free_ftrace_hash(ops->func_hash->notrace_hash); | |
5500fa51 JO |
1266 | } |
1267 | ||
33dc9b12 SR |
1268 | static struct ftrace_hash *alloc_ftrace_hash(int size_bits) |
1269 | { | |
1270 | struct ftrace_hash *hash; | |
1271 | int size; | |
1272 | ||
1273 | hash = kzalloc(sizeof(*hash), GFP_KERNEL); | |
1274 | if (!hash) | |
1275 | return NULL; | |
1276 | ||
1277 | size = 1 << size_bits; | |
47b0edcb | 1278 | hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL); |
33dc9b12 SR |
1279 | |
1280 | if (!hash->buckets) { | |
1281 | kfree(hash); | |
1282 | return NULL; | |
1283 | } | |
1284 | ||
1285 | hash->size_bits = size_bits; | |
1286 | ||
1287 | return hash; | |
1288 | } | |
1289 | ||
673feb9d SRV |
1290 | |
1291 | static int ftrace_add_mod(struct trace_array *tr, | |
1292 | const char *func, const char *module, | |
1293 | int enable) | |
1294 | { | |
1295 | struct ftrace_mod_load *ftrace_mod; | |
1296 | struct list_head *mod_head = enable ? &tr->mod_trace : &tr->mod_notrace; | |
1297 | ||
1298 | ftrace_mod = kzalloc(sizeof(*ftrace_mod), GFP_KERNEL); | |
1299 | if (!ftrace_mod) | |
1300 | return -ENOMEM; | |
1301 | ||
1302 | ftrace_mod->func = kstrdup(func, GFP_KERNEL); | |
1303 | ftrace_mod->module = kstrdup(module, GFP_KERNEL); | |
1304 | ftrace_mod->enable = enable; | |
1305 | ||
1306 | if (!ftrace_mod->func || !ftrace_mod->module) | |
1307 | goto out_free; | |
1308 | ||
1309 | list_add(&ftrace_mod->list, mod_head); | |
1310 | ||
1311 | return 0; | |
1312 | ||
1313 | out_free: | |
1314 | free_ftrace_mod(ftrace_mod); | |
1315 | ||
1316 | return -ENOMEM; | |
1317 | } | |
1318 | ||
33dc9b12 SR |
1319 | static struct ftrace_hash * |
1320 | alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) | |
1321 | { | |
1322 | struct ftrace_func_entry *entry; | |
1323 | struct ftrace_hash *new_hash; | |
33dc9b12 SR |
1324 | int size; |
1325 | int ret; | |
1326 | int i; | |
1327 | ||
1328 | new_hash = alloc_ftrace_hash(size_bits); | |
1329 | if (!new_hash) | |
1330 | return NULL; | |
1331 | ||
8c08f0d5 SRV |
1332 | if (hash) |
1333 | new_hash->flags = hash->flags; | |
1334 | ||
33dc9b12 | 1335 | /* Empty hash? */ |
06a51d93 | 1336 | if (ftrace_hash_empty(hash)) |
33dc9b12 SR |
1337 | return new_hash; |
1338 | ||
1339 | size = 1 << hash->size_bits; | |
1340 | for (i = 0; i < size; i++) { | |
b67bfe0d | 1341 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { |
33dc9b12 SR |
1342 | ret = add_hash_entry(new_hash, entry->ip); |
1343 | if (ret < 0) | |
1344 | goto free_hash; | |
1345 | } | |
1346 | } | |
1347 | ||
1348 | FTRACE_WARN_ON(new_hash->count != hash->count); | |
1349 | ||
1350 | return new_hash; | |
1351 | ||
1352 | free_hash: | |
1353 | free_ftrace_hash(new_hash); | |
1354 | return NULL; | |
1355 | } | |
1356 | ||
41fb61c2 | 1357 | static void |
84261912 | 1358 | ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash); |
41fb61c2 | 1359 | static void |
84261912 | 1360 | ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash); |
41fb61c2 | 1361 | |
f8b8be8a MH |
1362 | static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, |
1363 | struct ftrace_hash *new_hash); | |
1364 | ||
714641c3 | 1365 | static struct ftrace_hash *dup_hash(struct ftrace_hash *src, int size) |
33dc9b12 SR |
1366 | { |
1367 | struct ftrace_func_entry *entry; | |
07fd5515 | 1368 | struct ftrace_hash *new_hash; |
714641c3 SRV |
1369 | struct hlist_head *hhd; |
1370 | struct hlist_node *tn; | |
33dc9b12 SR |
1371 | int bits = 0; |
1372 | int i; | |
1373 | ||
33dc9b12 SR |
1374 | /* |
1375 | * Make the hash size about 1/2 the # found | |
1376 | */ | |
1377 | for (size /= 2; size; size >>= 1) | |
1378 | bits++; | |
1379 | ||
1380 | /* Don't allocate too much */ | |
1381 | if (bits > FTRACE_HASH_MAX_BITS) | |
1382 | bits = FTRACE_HASH_MAX_BITS; | |
1383 | ||
07fd5515 SR |
1384 | new_hash = alloc_ftrace_hash(bits); |
1385 | if (!new_hash) | |
3e278c0d | 1386 | return NULL; |
33dc9b12 | 1387 | |
8c08f0d5 SRV |
1388 | new_hash->flags = src->flags; |
1389 | ||
33dc9b12 SR |
1390 | size = 1 << src->size_bits; |
1391 | for (i = 0; i < size; i++) { | |
1392 | hhd = &src->buckets[i]; | |
b67bfe0d | 1393 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) { |
33dc9b12 | 1394 | remove_hash_entry(src, entry); |
07fd5515 | 1395 | __add_hash_entry(new_hash, entry); |
33dc9b12 SR |
1396 | } |
1397 | } | |
3e278c0d NK |
1398 | return new_hash; |
1399 | } | |
1400 | ||
714641c3 SRV |
1401 | static struct ftrace_hash * |
1402 | __ftrace_hash_move(struct ftrace_hash *src) | |
1403 | { | |
1404 | int size = src->count; | |
1405 | ||
1406 | /* | |
1407 | * If the new source is empty, just return the empty_hash. | |
1408 | */ | |
1409 | if (ftrace_hash_empty(src)) | |
1410 | return EMPTY_HASH; | |
1411 | ||
1412 | return dup_hash(src, size); | |
1413 | } | |
1414 | ||
3e278c0d NK |
1415 | static int |
1416 | ftrace_hash_move(struct ftrace_ops *ops, int enable, | |
1417 | struct ftrace_hash **dst, struct ftrace_hash *src) | |
1418 | { | |
1419 | struct ftrace_hash *new_hash; | |
1420 | int ret; | |
1421 | ||
1422 | /* Reject setting notrace hash on IPMODIFY ftrace_ops */ | |
1423 | if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable) | |
1424 | return -EINVAL; | |
1425 | ||
1426 | new_hash = __ftrace_hash_move(src); | |
1427 | if (!new_hash) | |
1428 | return -ENOMEM; | |
1429 | ||
f8b8be8a MH |
1430 | /* Make sure this can be applied if it is IPMODIFY ftrace_ops */ |
1431 | if (enable) { | |
1432 | /* IPMODIFY should be updated only when filter_hash updating */ | |
1433 | ret = ftrace_hash_ipmodify_update(ops, new_hash); | |
1434 | if (ret < 0) { | |
1435 | free_ftrace_hash(new_hash); | |
1436 | return ret; | |
1437 | } | |
1438 | } | |
1439 | ||
5c27c775 MH |
1440 | /* |
1441 | * Remove the current set, update the hash and add | |
1442 | * them back. | |
1443 | */ | |
84261912 | 1444 | ftrace_hash_rec_disable_modify(ops, enable); |
5c27c775 | 1445 | |
07fd5515 | 1446 | rcu_assign_pointer(*dst, new_hash); |
07fd5515 | 1447 | |
84261912 | 1448 | ftrace_hash_rec_enable_modify(ops, enable); |
41fb61c2 | 1449 | |
5c27c775 | 1450 | return 0; |
33dc9b12 SR |
1451 | } |
1452 | ||
fef5aeee SRRH |
1453 | static bool hash_contains_ip(unsigned long ip, |
1454 | struct ftrace_ops_hash *hash) | |
1455 | { | |
1456 | /* | |
1457 | * The function record is a match if it exists in the filter | |
1458 | * hash and not in the notrace hash. Note, an emty hash is | |
1459 | * considered a match for the filter hash, but an empty | |
1460 | * notrace hash is considered not in the notrace hash. | |
1461 | */ | |
1462 | return (ftrace_hash_empty(hash->filter_hash) || | |
2b2c279c | 1463 | __ftrace_lookup_ip(hash->filter_hash, ip)) && |
fef5aeee | 1464 | (ftrace_hash_empty(hash->notrace_hash) || |
2b2c279c | 1465 | !__ftrace_lookup_ip(hash->notrace_hash, ip)); |
fef5aeee SRRH |
1466 | } |
1467 | ||
b848914c SR |
1468 | /* |
1469 | * Test the hashes for this ops to see if we want to call | |
1470 | * the ops->func or not. | |
1471 | * | |
1472 | * It's a match if the ip is in the ops->filter_hash or | |
1473 | * the filter_hash does not exist or is empty, | |
1474 | * AND | |
1475 | * the ip is not in the ops->notrace_hash. | |
cdbe61bf SR |
1476 | * |
1477 | * This needs to be called with preemption disabled as | |
74401729 | 1478 | * the hashes are freed with call_rcu(). |
b848914c | 1479 | */ |
3306fc4a | 1480 | int |
195a8afc | 1481 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
b848914c | 1482 | { |
fef5aeee | 1483 | struct ftrace_ops_hash hash; |
b848914c SR |
1484 | int ret; |
1485 | ||
195a8afc SRRH |
1486 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
1487 | /* | |
1488 | * There's a small race when adding ops that the ftrace handler | |
1489 | * that wants regs, may be called without them. We can not | |
1490 | * allow that handler to be called if regs is NULL. | |
1491 | */ | |
1492 | if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS)) | |
1493 | return 0; | |
1494 | #endif | |
1495 | ||
f86f4180 CZ |
1496 | rcu_assign_pointer(hash.filter_hash, ops->func_hash->filter_hash); |
1497 | rcu_assign_pointer(hash.notrace_hash, ops->func_hash->notrace_hash); | |
b848914c | 1498 | |
fef5aeee | 1499 | if (hash_contains_ip(ip, &hash)) |
b848914c SR |
1500 | ret = 1; |
1501 | else | |
1502 | ret = 0; | |
b848914c SR |
1503 | |
1504 | return ret; | |
1505 | } | |
1506 | ||
493762fc SR |
1507 | /* |
1508 | * This is a double for. Do not use 'break' to break out of the loop, | |
1509 | * you must use a goto. | |
1510 | */ | |
1511 | #define do_for_each_ftrace_rec(pg, rec) \ | |
1512 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
1513 | int _____i; \ | |
1514 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
1515 | rec = &pg->records[_____i]; | |
1516 | ||
1517 | #define while_for_each_ftrace_rec() \ | |
1518 | } \ | |
1519 | } | |
1520 | ||
5855fead SR |
1521 | |
1522 | static int ftrace_cmp_recs(const void *a, const void *b) | |
1523 | { | |
a650e02a SR |
1524 | const struct dyn_ftrace *key = a; |
1525 | const struct dyn_ftrace *rec = b; | |
5855fead | 1526 | |
a650e02a | 1527 | if (key->flags < rec->ip) |
5855fead | 1528 | return -1; |
a650e02a SR |
1529 | if (key->ip >= rec->ip + MCOUNT_INSN_SIZE) |
1530 | return 1; | |
5855fead SR |
1531 | return 0; |
1532 | } | |
1533 | ||
7e16f581 SRV |
1534 | static struct dyn_ftrace *lookup_rec(unsigned long start, unsigned long end) |
1535 | { | |
1536 | struct ftrace_page *pg; | |
1537 | struct dyn_ftrace *rec = NULL; | |
1538 | struct dyn_ftrace key; | |
1539 | ||
1540 | key.ip = start; | |
1541 | key.flags = end; /* overload flags, as it is unsigned long */ | |
1542 | ||
1543 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
1544 | if (end < pg->records[0].ip || | |
1545 | start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) | |
1546 | continue; | |
1547 | rec = bsearch(&key, pg->records, pg->index, | |
1548 | sizeof(struct dyn_ftrace), | |
1549 | ftrace_cmp_recs); | |
d9815bff AS |
1550 | if (rec) |
1551 | break; | |
7e16f581 SRV |
1552 | } |
1553 | return rec; | |
1554 | } | |
1555 | ||
04cf31a7 ME |
1556 | /** |
1557 | * ftrace_location_range - return the first address of a traced location | |
1558 | * if it touches the given ip range | |
1559 | * @start: start of range to search. | |
1560 | * @end: end of range to search (inclusive). @end points to the last byte | |
1561 | * to check. | |
1562 | * | |
1563 | * Returns rec->ip if the related ftrace location is a least partly within | |
1564 | * the given address range. That is, the first address of the instruction | |
1565 | * that is either a NOP or call to the function tracer. It checks the ftrace | |
1566 | * internal tables to determine if the address belongs or not. | |
1567 | */ | |
1568 | unsigned long ftrace_location_range(unsigned long start, unsigned long end) | |
c88fd863 | 1569 | { |
c88fd863 | 1570 | struct dyn_ftrace *rec; |
5855fead | 1571 | |
7e16f581 SRV |
1572 | rec = lookup_rec(start, end); |
1573 | if (rec) | |
1574 | return rec->ip; | |
c88fd863 SR |
1575 | |
1576 | return 0; | |
1577 | } | |
1578 | ||
a650e02a SR |
1579 | /** |
1580 | * ftrace_location - return true if the ip giving is a traced location | |
1581 | * @ip: the instruction pointer to check | |
1582 | * | |
f0cf973a | 1583 | * Returns rec->ip if @ip given is a pointer to a ftrace location. |
a650e02a SR |
1584 | * That is, the instruction that is either a NOP or call to |
1585 | * the function tracer. It checks the ftrace internal tables to | |
1586 | * determine if the address belongs or not. | |
1587 | */ | |
f0cf973a | 1588 | unsigned long ftrace_location(unsigned long ip) |
a650e02a SR |
1589 | { |
1590 | return ftrace_location_range(ip, ip); | |
1591 | } | |
1592 | ||
1593 | /** | |
1594 | * ftrace_text_reserved - return true if range contains an ftrace location | |
1595 | * @start: start of range to search | |
1596 | * @end: end of range to search (inclusive). @end points to the last byte to check. | |
1597 | * | |
1598 | * Returns 1 if @start and @end contains a ftrace location. | |
1599 | * That is, the instruction that is either a NOP or call to | |
1600 | * the function tracer. It checks the ftrace internal tables to | |
1601 | * determine if the address belongs or not. | |
1602 | */ | |
d88471cb | 1603 | int ftrace_text_reserved(const void *start, const void *end) |
a650e02a | 1604 | { |
f0cf973a SR |
1605 | unsigned long ret; |
1606 | ||
1607 | ret = ftrace_location_range((unsigned long)start, | |
1608 | (unsigned long)end); | |
1609 | ||
1610 | return (int)!!ret; | |
a650e02a SR |
1611 | } |
1612 | ||
4fbb48cb SRRH |
1613 | /* Test if ops registered to this rec needs regs */ |
1614 | static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec) | |
1615 | { | |
1616 | struct ftrace_ops *ops; | |
1617 | bool keep_regs = false; | |
1618 | ||
1619 | for (ops = ftrace_ops_list; | |
1620 | ops != &ftrace_list_end; ops = ops->next) { | |
1621 | /* pass rec in as regs to have non-NULL val */ | |
1622 | if (ftrace_ops_test(ops, rec->ip, rec)) { | |
1623 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1624 | keep_regs = true; | |
1625 | break; | |
1626 | } | |
1627 | } | |
1628 | } | |
1629 | ||
1630 | return keep_regs; | |
1631 | } | |
1632 | ||
a124692b CJ |
1633 | static struct ftrace_ops * |
1634 | ftrace_find_tramp_ops_any(struct dyn_ftrace *rec); | |
1635 | static struct ftrace_ops * | |
1636 | ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops); | |
1637 | ||
84b6d3e6 | 1638 | static bool __ftrace_hash_rec_update(struct ftrace_ops *ops, |
ed926f9b SR |
1639 | int filter_hash, |
1640 | bool inc) | |
1641 | { | |
1642 | struct ftrace_hash *hash; | |
1643 | struct ftrace_hash *other_hash; | |
1644 | struct ftrace_page *pg; | |
1645 | struct dyn_ftrace *rec; | |
84b6d3e6 | 1646 | bool update = false; |
ed926f9b | 1647 | int count = 0; |
8c08f0d5 | 1648 | int all = false; |
ed926f9b SR |
1649 | |
1650 | /* Only update if the ops has been registered */ | |
1651 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
84b6d3e6 | 1652 | return false; |
ed926f9b SR |
1653 | |
1654 | /* | |
1655 | * In the filter_hash case: | |
1656 | * If the count is zero, we update all records. | |
1657 | * Otherwise we just update the items in the hash. | |
1658 | * | |
1659 | * In the notrace_hash case: | |
1660 | * We enable the update in the hash. | |
1661 | * As disabling notrace means enabling the tracing, | |
1662 | * and enabling notrace means disabling, the inc variable | |
1663 | * gets inversed. | |
1664 | */ | |
1665 | if (filter_hash) { | |
33b7f99c SRRH |
1666 | hash = ops->func_hash->filter_hash; |
1667 | other_hash = ops->func_hash->notrace_hash; | |
06a51d93 | 1668 | if (ftrace_hash_empty(hash)) |
8c08f0d5 | 1669 | all = true; |
ed926f9b SR |
1670 | } else { |
1671 | inc = !inc; | |
33b7f99c SRRH |
1672 | hash = ops->func_hash->notrace_hash; |
1673 | other_hash = ops->func_hash->filter_hash; | |
ed926f9b SR |
1674 | /* |
1675 | * If the notrace hash has no items, | |
1676 | * then there's nothing to do. | |
1677 | */ | |
06a51d93 | 1678 | if (ftrace_hash_empty(hash)) |
84b6d3e6 | 1679 | return false; |
ed926f9b SR |
1680 | } |
1681 | ||
1682 | do_for_each_ftrace_rec(pg, rec) { | |
1683 | int in_other_hash = 0; | |
1684 | int in_hash = 0; | |
1685 | int match = 0; | |
1686 | ||
b7ffffbb SRRH |
1687 | if (rec->flags & FTRACE_FL_DISABLED) |
1688 | continue; | |
1689 | ||
ed926f9b SR |
1690 | if (all) { |
1691 | /* | |
1692 | * Only the filter_hash affects all records. | |
1693 | * Update if the record is not in the notrace hash. | |
1694 | */ | |
b848914c | 1695 | if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) |
ed926f9b SR |
1696 | match = 1; |
1697 | } else { | |
06a51d93 SR |
1698 | in_hash = !!ftrace_lookup_ip(hash, rec->ip); |
1699 | in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip); | |
ed926f9b SR |
1700 | |
1701 | /* | |
19eab4a4 SRRH |
1702 | * If filter_hash is set, we want to match all functions |
1703 | * that are in the hash but not in the other hash. | |
ed926f9b | 1704 | * |
19eab4a4 SRRH |
1705 | * If filter_hash is not set, then we are decrementing. |
1706 | * That means we match anything that is in the hash | |
1707 | * and also in the other_hash. That is, we need to turn | |
1708 | * off functions in the other hash because they are disabled | |
1709 | * by this hash. | |
ed926f9b SR |
1710 | */ |
1711 | if (filter_hash && in_hash && !in_other_hash) | |
1712 | match = 1; | |
1713 | else if (!filter_hash && in_hash && | |
06a51d93 | 1714 | (in_other_hash || ftrace_hash_empty(other_hash))) |
ed926f9b SR |
1715 | match = 1; |
1716 | } | |
1717 | if (!match) | |
1718 | continue; | |
1719 | ||
1720 | if (inc) { | |
1721 | rec->flags++; | |
0376bde1 | 1722 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX)) |
84b6d3e6 | 1723 | return false; |
79922b80 | 1724 | |
763e34e7 SRV |
1725 | if (ops->flags & FTRACE_OPS_FL_DIRECT) |
1726 | rec->flags |= FTRACE_FL_DIRECT; | |
1727 | ||
79922b80 SRRH |
1728 | /* |
1729 | * If there's only a single callback registered to a | |
1730 | * function, and the ops has a trampoline registered | |
1731 | * for it, then we can call it directly. | |
1732 | */ | |
fef5aeee | 1733 | if (ftrace_rec_count(rec) == 1 && ops->trampoline) |
79922b80 | 1734 | rec->flags |= FTRACE_FL_TRAMP; |
fef5aeee | 1735 | else |
79922b80 SRRH |
1736 | /* |
1737 | * If we are adding another function callback | |
1738 | * to this function, and the previous had a | |
bce0b6c5 SRRH |
1739 | * custom trampoline in use, then we need to go |
1740 | * back to the default trampoline. | |
79922b80 | 1741 | */ |
fef5aeee | 1742 | rec->flags &= ~FTRACE_FL_TRAMP; |
79922b80 | 1743 | |
08f6fba5 SR |
1744 | /* |
1745 | * If any ops wants regs saved for this function | |
1746 | * then all ops will get saved regs. | |
1747 | */ | |
1748 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) | |
1749 | rec->flags |= FTRACE_FL_REGS; | |
ed926f9b | 1750 | } else { |
0376bde1 | 1751 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0)) |
84b6d3e6 | 1752 | return false; |
ed926f9b | 1753 | rec->flags--; |
79922b80 | 1754 | |
763e34e7 SRV |
1755 | /* |
1756 | * Only the internal direct_ops should have the | |
1757 | * DIRECT flag set. Thus, if it is removing a | |
1758 | * function, then that function should no longer | |
1759 | * be direct. | |
1760 | */ | |
1761 | if (ops->flags & FTRACE_OPS_FL_DIRECT) | |
1762 | rec->flags &= ~FTRACE_FL_DIRECT; | |
1763 | ||
4fbb48cb SRRH |
1764 | /* |
1765 | * If the rec had REGS enabled and the ops that is | |
1766 | * being removed had REGS set, then see if there is | |
1767 | * still any ops for this record that wants regs. | |
1768 | * If not, we can stop recording them. | |
1769 | */ | |
0376bde1 | 1770 | if (ftrace_rec_count(rec) > 0 && |
4fbb48cb SRRH |
1771 | rec->flags & FTRACE_FL_REGS && |
1772 | ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1773 | if (!test_rec_ops_needs_regs(rec)) | |
1774 | rec->flags &= ~FTRACE_FL_REGS; | |
1775 | } | |
79922b80 | 1776 | |
fef5aeee | 1777 | /* |
a124692b CJ |
1778 | * The TRAMP needs to be set only if rec count |
1779 | * is decremented to one, and the ops that is | |
1780 | * left has a trampoline. As TRAMP can only be | |
1781 | * enabled if there is only a single ops attached | |
1782 | * to it. | |
fef5aeee | 1783 | */ |
a124692b CJ |
1784 | if (ftrace_rec_count(rec) == 1 && |
1785 | ftrace_find_tramp_ops_any(rec)) | |
1786 | rec->flags |= FTRACE_FL_TRAMP; | |
1787 | else | |
1788 | rec->flags &= ~FTRACE_FL_TRAMP; | |
fef5aeee | 1789 | |
79922b80 SRRH |
1790 | /* |
1791 | * flags will be cleared in ftrace_check_record() | |
1792 | * if rec count is zero. | |
1793 | */ | |
ed926f9b SR |
1794 | } |
1795 | count++; | |
84b6d3e6 JO |
1796 | |
1797 | /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */ | |
7375dca1 | 1798 | update |= ftrace_test_record(rec, true) != FTRACE_UPDATE_IGNORE; |
84b6d3e6 | 1799 | |
ed926f9b SR |
1800 | /* Shortcut, if we handled all records, we are done. */ |
1801 | if (!all && count == hash->count) | |
84b6d3e6 | 1802 | return update; |
ed926f9b | 1803 | } while_for_each_ftrace_rec(); |
84b6d3e6 JO |
1804 | |
1805 | return update; | |
ed926f9b SR |
1806 | } |
1807 | ||
84b6d3e6 | 1808 | static bool ftrace_hash_rec_disable(struct ftrace_ops *ops, |
ed926f9b SR |
1809 | int filter_hash) |
1810 | { | |
84b6d3e6 | 1811 | return __ftrace_hash_rec_update(ops, filter_hash, 0); |
ed926f9b SR |
1812 | } |
1813 | ||
84b6d3e6 | 1814 | static bool ftrace_hash_rec_enable(struct ftrace_ops *ops, |
ed926f9b SR |
1815 | int filter_hash) |
1816 | { | |
84b6d3e6 | 1817 | return __ftrace_hash_rec_update(ops, filter_hash, 1); |
ed926f9b SR |
1818 | } |
1819 | ||
84261912 SRRH |
1820 | static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops, |
1821 | int filter_hash, int inc) | |
1822 | { | |
1823 | struct ftrace_ops *op; | |
1824 | ||
1825 | __ftrace_hash_rec_update(ops, filter_hash, inc); | |
1826 | ||
1827 | if (ops->func_hash != &global_ops.local_hash) | |
1828 | return; | |
1829 | ||
1830 | /* | |
1831 | * If the ops shares the global_ops hash, then we need to update | |
1832 | * all ops that are enabled and use this hash. | |
1833 | */ | |
1834 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1835 | /* Already done */ | |
1836 | if (op == ops) | |
1837 | continue; | |
1838 | if (op->func_hash == &global_ops.local_hash) | |
1839 | __ftrace_hash_rec_update(op, filter_hash, inc); | |
1840 | } while_for_each_ftrace_op(op); | |
1841 | } | |
1842 | ||
1843 | static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, | |
1844 | int filter_hash) | |
1845 | { | |
1846 | ftrace_hash_rec_update_modify(ops, filter_hash, 0); | |
1847 | } | |
1848 | ||
1849 | static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, | |
1850 | int filter_hash) | |
1851 | { | |
1852 | ftrace_hash_rec_update_modify(ops, filter_hash, 1); | |
1853 | } | |
1854 | ||
f8b8be8a MH |
1855 | /* |
1856 | * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK | |
1857 | * or no-needed to update, -EBUSY if it detects a conflict of the flag | |
1858 | * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs. | |
1859 | * Note that old_hash and new_hash has below meanings | |
1860 | * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected) | |
1861 | * - If the hash is EMPTY_HASH, it hits nothing | |
1862 | * - Anything else hits the recs which match the hash entries. | |
1863 | */ | |
1864 | static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops, | |
1865 | struct ftrace_hash *old_hash, | |
1866 | struct ftrace_hash *new_hash) | |
1867 | { | |
1868 | struct ftrace_page *pg; | |
1869 | struct dyn_ftrace *rec, *end = NULL; | |
1870 | int in_old, in_new; | |
1871 | ||
1872 | /* Only update if the ops has been registered */ | |
1873 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
1874 | return 0; | |
1875 | ||
1876 | if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY)) | |
1877 | return 0; | |
1878 | ||
1879 | /* | |
1880 | * Since the IPMODIFY is a very address sensitive action, we do not | |
1881 | * allow ftrace_ops to set all functions to new hash. | |
1882 | */ | |
1883 | if (!new_hash || !old_hash) | |
1884 | return -EINVAL; | |
1885 | ||
1886 | /* Update rec->flags */ | |
1887 | do_for_each_ftrace_rec(pg, rec) { | |
546fece4 SRRH |
1888 | |
1889 | if (rec->flags & FTRACE_FL_DISABLED) | |
1890 | continue; | |
1891 | ||
f8b8be8a MH |
1892 | /* We need to update only differences of filter_hash */ |
1893 | in_old = !!ftrace_lookup_ip(old_hash, rec->ip); | |
1894 | in_new = !!ftrace_lookup_ip(new_hash, rec->ip); | |
1895 | if (in_old == in_new) | |
1896 | continue; | |
1897 | ||
1898 | if (in_new) { | |
1899 | /* New entries must ensure no others are using it */ | |
1900 | if (rec->flags & FTRACE_FL_IPMODIFY) | |
1901 | goto rollback; | |
1902 | rec->flags |= FTRACE_FL_IPMODIFY; | |
1903 | } else /* Removed entry */ | |
1904 | rec->flags &= ~FTRACE_FL_IPMODIFY; | |
1905 | } while_for_each_ftrace_rec(); | |
1906 | ||
1907 | return 0; | |
1908 | ||
1909 | rollback: | |
1910 | end = rec; | |
1911 | ||
1912 | /* Roll back what we did above */ | |
1913 | do_for_each_ftrace_rec(pg, rec) { | |
546fece4 SRRH |
1914 | |
1915 | if (rec->flags & FTRACE_FL_DISABLED) | |
1916 | continue; | |
1917 | ||
f8b8be8a MH |
1918 | if (rec == end) |
1919 | goto err_out; | |
1920 | ||
1921 | in_old = !!ftrace_lookup_ip(old_hash, rec->ip); | |
1922 | in_new = !!ftrace_lookup_ip(new_hash, rec->ip); | |
1923 | if (in_old == in_new) | |
1924 | continue; | |
1925 | ||
1926 | if (in_new) | |
1927 | rec->flags &= ~FTRACE_FL_IPMODIFY; | |
1928 | else | |
1929 | rec->flags |= FTRACE_FL_IPMODIFY; | |
1930 | } while_for_each_ftrace_rec(); | |
1931 | ||
1932 | err_out: | |
1933 | return -EBUSY; | |
1934 | } | |
1935 | ||
1936 | static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops) | |
1937 | { | |
1938 | struct ftrace_hash *hash = ops->func_hash->filter_hash; | |
1939 | ||
1940 | if (ftrace_hash_empty(hash)) | |
1941 | hash = NULL; | |
1942 | ||
1943 | return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash); | |
1944 | } | |
1945 | ||
1946 | /* Disabling always succeeds */ | |
1947 | static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops) | |
1948 | { | |
1949 | struct ftrace_hash *hash = ops->func_hash->filter_hash; | |
1950 | ||
1951 | if (ftrace_hash_empty(hash)) | |
1952 | hash = NULL; | |
1953 | ||
1954 | __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH); | |
1955 | } | |
1956 | ||
1957 | static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, | |
1958 | struct ftrace_hash *new_hash) | |
1959 | { | |
1960 | struct ftrace_hash *old_hash = ops->func_hash->filter_hash; | |
1961 | ||
1962 | if (ftrace_hash_empty(old_hash)) | |
1963 | old_hash = NULL; | |
1964 | ||
1965 | if (ftrace_hash_empty(new_hash)) | |
1966 | new_hash = NULL; | |
1967 | ||
1968 | return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash); | |
1969 | } | |
1970 | ||
b05086c7 | 1971 | static void print_ip_ins(const char *fmt, const unsigned char *p) |
b17e8a37 SR |
1972 | { |
1973 | int i; | |
1974 | ||
1975 | printk(KERN_CONT "%s", fmt); | |
1976 | ||
1977 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
1978 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
1979 | } | |
1980 | ||
02a392a0 | 1981 | enum ftrace_bug_type ftrace_bug_type; |
b05086c7 | 1982 | const void *ftrace_expected; |
02a392a0 SRRH |
1983 | |
1984 | static void print_bug_type(void) | |
1985 | { | |
1986 | switch (ftrace_bug_type) { | |
1987 | case FTRACE_BUG_UNKNOWN: | |
1988 | break; | |
1989 | case FTRACE_BUG_INIT: | |
1990 | pr_info("Initializing ftrace call sites\n"); | |
1991 | break; | |
1992 | case FTRACE_BUG_NOP: | |
1993 | pr_info("Setting ftrace call site to NOP\n"); | |
1994 | break; | |
1995 | case FTRACE_BUG_CALL: | |
1996 | pr_info("Setting ftrace call site to call ftrace function\n"); | |
1997 | break; | |
1998 | case FTRACE_BUG_UPDATE: | |
1999 | pr_info("Updating ftrace call site to call a different ftrace function\n"); | |
2000 | break; | |
2001 | } | |
2002 | } | |
2003 | ||
c88fd863 SR |
2004 | /** |
2005 | * ftrace_bug - report and shutdown function tracer | |
2006 | * @failed: The failed type (EFAULT, EINVAL, EPERM) | |
4fd3279b | 2007 | * @rec: The record that failed |
c88fd863 SR |
2008 | * |
2009 | * The arch code that enables or disables the function tracing | |
2010 | * can call ftrace_bug() when it has detected a problem in | |
2011 | * modifying the code. @failed should be one of either: | |
2012 | * EFAULT - if the problem happens on reading the @ip address | |
2013 | * EINVAL - if what is read at @ip is not what was expected | |
9efb85c5 | 2014 | * EPERM - if the problem happens on writing to the @ip address |
c88fd863 | 2015 | */ |
4fd3279b | 2016 | void ftrace_bug(int failed, struct dyn_ftrace *rec) |
b17e8a37 | 2017 | { |
4fd3279b SRRH |
2018 | unsigned long ip = rec ? rec->ip : 0; |
2019 | ||
b17e8a37 SR |
2020 | switch (failed) { |
2021 | case -EFAULT: | |
2022 | FTRACE_WARN_ON_ONCE(1); | |
2023 | pr_info("ftrace faulted on modifying "); | |
2024 | print_ip_sym(ip); | |
2025 | break; | |
2026 | case -EINVAL: | |
2027 | FTRACE_WARN_ON_ONCE(1); | |
2028 | pr_info("ftrace failed to modify "); | |
2029 | print_ip_sym(ip); | |
b05086c7 | 2030 | print_ip_ins(" actual: ", (unsigned char *)ip); |
4fd3279b | 2031 | pr_cont("\n"); |
b05086c7 SRRH |
2032 | if (ftrace_expected) { |
2033 | print_ip_ins(" expected: ", ftrace_expected); | |
2034 | pr_cont("\n"); | |
2035 | } | |
b17e8a37 SR |
2036 | break; |
2037 | case -EPERM: | |
2038 | FTRACE_WARN_ON_ONCE(1); | |
2039 | pr_info("ftrace faulted on writing "); | |
2040 | print_ip_sym(ip); | |
2041 | break; | |
2042 | default: | |
2043 | FTRACE_WARN_ON_ONCE(1); | |
2044 | pr_info("ftrace faulted on unknown error "); | |
2045 | print_ip_sym(ip); | |
2046 | } | |
02a392a0 | 2047 | print_bug_type(); |
4fd3279b SRRH |
2048 | if (rec) { |
2049 | struct ftrace_ops *ops = NULL; | |
2050 | ||
2051 | pr_info("ftrace record flags: %lx\n", rec->flags); | |
2052 | pr_cont(" (%ld)%s", ftrace_rec_count(rec), | |
2053 | rec->flags & FTRACE_FL_REGS ? " R" : " "); | |
2054 | if (rec->flags & FTRACE_FL_TRAMP_EN) { | |
2055 | ops = ftrace_find_tramp_ops_any(rec); | |
39daa7b9 SRRH |
2056 | if (ops) { |
2057 | do { | |
2058 | pr_cont("\ttramp: %pS (%pS)", | |
2059 | (void *)ops->trampoline, | |
2060 | (void *)ops->func); | |
2061 | ops = ftrace_find_tramp_ops_next(rec, ops); | |
2062 | } while (ops); | |
2063 | } else | |
4fd3279b SRRH |
2064 | pr_cont("\ttramp: ERROR!"); |
2065 | ||
2066 | } | |
2067 | ip = ftrace_get_addr_curr(rec); | |
39daa7b9 | 2068 | pr_cont("\n expected tramp: %lx\n", ip); |
4fd3279b | 2069 | } |
b17e8a37 SR |
2070 | } |
2071 | ||
7375dca1 | 2072 | static int ftrace_check_record(struct dyn_ftrace *rec, bool enable, bool update) |
5072c59f | 2073 | { |
64fbcd16 | 2074 | unsigned long flag = 0UL; |
e7d3737e | 2075 | |
02a392a0 SRRH |
2076 | ftrace_bug_type = FTRACE_BUG_UNKNOWN; |
2077 | ||
b7ffffbb SRRH |
2078 | if (rec->flags & FTRACE_FL_DISABLED) |
2079 | return FTRACE_UPDATE_IGNORE; | |
2080 | ||
982c350b | 2081 | /* |
30fb6aa7 | 2082 | * If we are updating calls: |
982c350b | 2083 | * |
ed926f9b SR |
2084 | * If the record has a ref count, then we need to enable it |
2085 | * because someone is using it. | |
982c350b | 2086 | * |
ed926f9b SR |
2087 | * Otherwise we make sure its disabled. |
2088 | * | |
30fb6aa7 | 2089 | * If we are disabling calls, then disable all records that |
ed926f9b | 2090 | * are enabled. |
982c350b | 2091 | */ |
0376bde1 | 2092 | if (enable && ftrace_rec_count(rec)) |
ed926f9b | 2093 | flag = FTRACE_FL_ENABLED; |
982c350b | 2094 | |
08f6fba5 | 2095 | /* |
79922b80 SRRH |
2096 | * If enabling and the REGS flag does not match the REGS_EN, or |
2097 | * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore | |
2098 | * this record. Set flags to fail the compare against ENABLED. | |
763e34e7 | 2099 | * Same for direct calls. |
08f6fba5 | 2100 | */ |
79922b80 | 2101 | if (flag) { |
763e34e7 | 2102 | if (!(rec->flags & FTRACE_FL_REGS) != |
79922b80 SRRH |
2103 | !(rec->flags & FTRACE_FL_REGS_EN)) |
2104 | flag |= FTRACE_FL_REGS; | |
2105 | ||
763e34e7 | 2106 | if (!(rec->flags & FTRACE_FL_TRAMP) != |
79922b80 SRRH |
2107 | !(rec->flags & FTRACE_FL_TRAMP_EN)) |
2108 | flag |= FTRACE_FL_TRAMP; | |
763e34e7 SRV |
2109 | |
2110 | /* | |
2111 | * Direct calls are special, as count matters. | |
2112 | * We must test the record for direct, if the | |
2113 | * DIRECT and DIRECT_EN do not match, but only | |
2114 | * if the count is 1. That's because, if the | |
2115 | * count is something other than one, we do not | |
2116 | * want the direct enabled (it will be done via the | |
2117 | * direct helper). But if DIRECT_EN is set, and | |
2118 | * the count is not one, we need to clear it. | |
2119 | */ | |
2120 | if (ftrace_rec_count(rec) == 1) { | |
2121 | if (!(rec->flags & FTRACE_FL_DIRECT) != | |
2122 | !(rec->flags & FTRACE_FL_DIRECT_EN)) | |
2123 | flag |= FTRACE_FL_DIRECT; | |
2124 | } else if (rec->flags & FTRACE_FL_DIRECT_EN) { | |
2125 | flag |= FTRACE_FL_DIRECT; | |
2126 | } | |
79922b80 | 2127 | } |
08f6fba5 | 2128 | |
64fbcd16 XG |
2129 | /* If the state of this record hasn't changed, then do nothing */ |
2130 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
c88fd863 | 2131 | return FTRACE_UPDATE_IGNORE; |
982c350b | 2132 | |
64fbcd16 | 2133 | if (flag) { |
08f6fba5 SR |
2134 | /* Save off if rec is being enabled (for return value) */ |
2135 | flag ^= rec->flags & FTRACE_FL_ENABLED; | |
2136 | ||
2137 | if (update) { | |
c88fd863 | 2138 | rec->flags |= FTRACE_FL_ENABLED; |
08f6fba5 SR |
2139 | if (flag & FTRACE_FL_REGS) { |
2140 | if (rec->flags & FTRACE_FL_REGS) | |
2141 | rec->flags |= FTRACE_FL_REGS_EN; | |
2142 | else | |
2143 | rec->flags &= ~FTRACE_FL_REGS_EN; | |
2144 | } | |
79922b80 SRRH |
2145 | if (flag & FTRACE_FL_TRAMP) { |
2146 | if (rec->flags & FTRACE_FL_TRAMP) | |
2147 | rec->flags |= FTRACE_FL_TRAMP_EN; | |
2148 | else | |
2149 | rec->flags &= ~FTRACE_FL_TRAMP_EN; | |
2150 | } | |
763e34e7 SRV |
2151 | if (flag & FTRACE_FL_DIRECT) { |
2152 | /* | |
2153 | * If there's only one user (direct_ops helper) | |
2154 | * then we can call the direct function | |
2155 | * directly (no ftrace trampoline). | |
2156 | */ | |
2157 | if (ftrace_rec_count(rec) == 1) { | |
2158 | if (rec->flags & FTRACE_FL_DIRECT) | |
2159 | rec->flags |= FTRACE_FL_DIRECT_EN; | |
2160 | else | |
2161 | rec->flags &= ~FTRACE_FL_DIRECT_EN; | |
2162 | } else { | |
2163 | /* | |
2164 | * Can only call directly if there's | |
2165 | * only one callback to the function. | |
2166 | */ | |
2167 | rec->flags &= ~FTRACE_FL_DIRECT_EN; | |
2168 | } | |
2169 | } | |
08f6fba5 SR |
2170 | } |
2171 | ||
2172 | /* | |
2173 | * If this record is being updated from a nop, then | |
2174 | * return UPDATE_MAKE_CALL. | |
08f6fba5 SR |
2175 | * Otherwise, |
2176 | * return UPDATE_MODIFY_CALL to tell the caller to convert | |
f1b2f2bd | 2177 | * from the save regs, to a non-save regs function or |
79922b80 | 2178 | * vice versa, or from a trampoline call. |
08f6fba5 | 2179 | */ |
02a392a0 SRRH |
2180 | if (flag & FTRACE_FL_ENABLED) { |
2181 | ftrace_bug_type = FTRACE_BUG_CALL; | |
08f6fba5 | 2182 | return FTRACE_UPDATE_MAKE_CALL; |
02a392a0 | 2183 | } |
f1b2f2bd | 2184 | |
02a392a0 | 2185 | ftrace_bug_type = FTRACE_BUG_UPDATE; |
f1b2f2bd | 2186 | return FTRACE_UPDATE_MODIFY_CALL; |
c88fd863 SR |
2187 | } |
2188 | ||
08f6fba5 SR |
2189 | if (update) { |
2190 | /* If there's no more users, clear all flags */ | |
0376bde1 | 2191 | if (!ftrace_rec_count(rec)) |
08f6fba5 SR |
2192 | rec->flags = 0; |
2193 | else | |
b24d443b SRRH |
2194 | /* |
2195 | * Just disable the record, but keep the ops TRAMP | |
2196 | * and REGS states. The _EN flags must be disabled though. | |
2197 | */ | |
2198 | rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN | | |
763e34e7 | 2199 | FTRACE_FL_REGS_EN | FTRACE_FL_DIRECT_EN); |
08f6fba5 | 2200 | } |
c88fd863 | 2201 | |
02a392a0 | 2202 | ftrace_bug_type = FTRACE_BUG_NOP; |
c88fd863 SR |
2203 | return FTRACE_UPDATE_MAKE_NOP; |
2204 | } | |
2205 | ||
2206 | /** | |
2207 | * ftrace_update_record, set a record that now is tracing or not | |
2208 | * @rec: the record to update | |
7375dca1 | 2209 | * @enable: set to true if the record is tracing, false to force disable |
c88fd863 SR |
2210 | * |
2211 | * The records that represent all functions that can be traced need | |
2212 | * to be updated when tracing has been enabled. | |
2213 | */ | |
7375dca1 | 2214 | int ftrace_update_record(struct dyn_ftrace *rec, bool enable) |
c88fd863 | 2215 | { |
7375dca1 | 2216 | return ftrace_check_record(rec, enable, true); |
c88fd863 SR |
2217 | } |
2218 | ||
2219 | /** | |
2220 | * ftrace_test_record, check if the record has been enabled or not | |
2221 | * @rec: the record to test | |
7375dca1 | 2222 | * @enable: set to true to check if enabled, false if it is disabled |
c88fd863 SR |
2223 | * |
2224 | * The arch code may need to test if a record is already set to | |
2225 | * tracing to determine how to modify the function code that it | |
2226 | * represents. | |
2227 | */ | |
7375dca1 | 2228 | int ftrace_test_record(struct dyn_ftrace *rec, bool enable) |
c88fd863 | 2229 | { |
7375dca1 | 2230 | return ftrace_check_record(rec, enable, false); |
c88fd863 SR |
2231 | } |
2232 | ||
5fecaa04 SRRH |
2233 | static struct ftrace_ops * |
2234 | ftrace_find_tramp_ops_any(struct dyn_ftrace *rec) | |
2235 | { | |
2236 | struct ftrace_ops *op; | |
fef5aeee | 2237 | unsigned long ip = rec->ip; |
5fecaa04 SRRH |
2238 | |
2239 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2240 | ||
2241 | if (!op->trampoline) | |
2242 | continue; | |
2243 | ||
fef5aeee | 2244 | if (hash_contains_ip(ip, op->func_hash)) |
5fecaa04 SRRH |
2245 | return op; |
2246 | } while_for_each_ftrace_op(op); | |
2247 | ||
2248 | return NULL; | |
2249 | } | |
2250 | ||
39daa7b9 SRRH |
2251 | static struct ftrace_ops * |
2252 | ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, | |
2253 | struct ftrace_ops *op) | |
2254 | { | |
2255 | unsigned long ip = rec->ip; | |
2256 | ||
2257 | while_for_each_ftrace_op(op) { | |
2258 | ||
2259 | if (!op->trampoline) | |
2260 | continue; | |
2261 | ||
2262 | if (hash_contains_ip(ip, op->func_hash)) | |
2263 | return op; | |
2264 | } | |
2265 | ||
2266 | return NULL; | |
2267 | } | |
2268 | ||
79922b80 SRRH |
2269 | static struct ftrace_ops * |
2270 | ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec) | |
2271 | { | |
2272 | struct ftrace_ops *op; | |
fef5aeee | 2273 | unsigned long ip = rec->ip; |
79922b80 | 2274 | |
fef5aeee SRRH |
2275 | /* |
2276 | * Need to check removed ops first. | |
2277 | * If they are being removed, and this rec has a tramp, | |
2278 | * and this rec is in the ops list, then it would be the | |
2279 | * one with the tramp. | |
2280 | */ | |
2281 | if (removed_ops) { | |
2282 | if (hash_contains_ip(ip, &removed_ops->old_hash)) | |
79922b80 SRRH |
2283 | return removed_ops; |
2284 | } | |
2285 | ||
fef5aeee SRRH |
2286 | /* |
2287 | * Need to find the current trampoline for a rec. | |
2288 | * Now, a trampoline is only attached to a rec if there | |
2289 | * was a single 'ops' attached to it. But this can be called | |
2290 | * when we are adding another op to the rec or removing the | |
2291 | * current one. Thus, if the op is being added, we can | |
2292 | * ignore it because it hasn't attached itself to the rec | |
4fc40904 SRRH |
2293 | * yet. |
2294 | * | |
2295 | * If an ops is being modified (hooking to different functions) | |
2296 | * then we don't care about the new functions that are being | |
2297 | * added, just the old ones (that are probably being removed). | |
2298 | * | |
2299 | * If we are adding an ops to a function that already is using | |
2300 | * a trampoline, it needs to be removed (trampolines are only | |
2301 | * for single ops connected), then an ops that is not being | |
2302 | * modified also needs to be checked. | |
fef5aeee | 2303 | */ |
79922b80 | 2304 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
fef5aeee SRRH |
2305 | |
2306 | if (!op->trampoline) | |
2307 | continue; | |
2308 | ||
2309 | /* | |
2310 | * If the ops is being added, it hasn't gotten to | |
2311 | * the point to be removed from this tree yet. | |
2312 | */ | |
2313 | if (op->flags & FTRACE_OPS_FL_ADDING) | |
79922b80 SRRH |
2314 | continue; |
2315 | ||
4fc40904 | 2316 | |
fef5aeee | 2317 | /* |
4fc40904 SRRH |
2318 | * If the ops is being modified and is in the old |
2319 | * hash, then it is probably being removed from this | |
2320 | * function. | |
fef5aeee | 2321 | */ |
fef5aeee SRRH |
2322 | if ((op->flags & FTRACE_OPS_FL_MODIFYING) && |
2323 | hash_contains_ip(ip, &op->old_hash)) | |
79922b80 | 2324 | return op; |
4fc40904 SRRH |
2325 | /* |
2326 | * If the ops is not being added or modified, and it's | |
2327 | * in its normal filter hash, then this must be the one | |
2328 | * we want! | |
2329 | */ | |
2330 | if (!(op->flags & FTRACE_OPS_FL_MODIFYING) && | |
2331 | hash_contains_ip(ip, op->func_hash)) | |
2332 | return op; | |
79922b80 SRRH |
2333 | |
2334 | } while_for_each_ftrace_op(op); | |
2335 | ||
2336 | return NULL; | |
2337 | } | |
2338 | ||
2339 | static struct ftrace_ops * | |
2340 | ftrace_find_tramp_ops_new(struct dyn_ftrace *rec) | |
2341 | { | |
2342 | struct ftrace_ops *op; | |
fef5aeee | 2343 | unsigned long ip = rec->ip; |
79922b80 SRRH |
2344 | |
2345 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2346 | /* pass rec in as regs to have non-NULL val */ | |
fef5aeee | 2347 | if (hash_contains_ip(ip, op->func_hash)) |
79922b80 SRRH |
2348 | return op; |
2349 | } while_for_each_ftrace_op(op); | |
2350 | ||
2351 | return NULL; | |
2352 | } | |
2353 | ||
763e34e7 SRV |
2354 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS |
2355 | /* Protected by rcu_tasks for reading, and direct_mutex for writing */ | |
2356 | static struct ftrace_hash *direct_functions = EMPTY_HASH; | |
2357 | static DEFINE_MUTEX(direct_mutex); | |
a3ad1a7e | 2358 | int ftrace_direct_func_count; |
763e34e7 SRV |
2359 | |
2360 | /* | |
2361 | * Search the direct_functions hash to see if the given instruction pointer | |
2362 | * has a direct caller attached to it. | |
2363 | */ | |
ff205766 | 2364 | unsigned long ftrace_find_rec_direct(unsigned long ip) |
763e34e7 SRV |
2365 | { |
2366 | struct ftrace_func_entry *entry; | |
2367 | ||
2368 | entry = __ftrace_lookup_ip(direct_functions, ip); | |
2369 | if (!entry) | |
2370 | return 0; | |
2371 | ||
2372 | return entry->direct; | |
2373 | } | |
2374 | ||
2375 | static void call_direct_funcs(unsigned long ip, unsigned long pip, | |
2376 | struct ftrace_ops *ops, struct pt_regs *regs) | |
2377 | { | |
2378 | unsigned long addr; | |
2379 | ||
ff205766 | 2380 | addr = ftrace_find_rec_direct(ip); |
763e34e7 SRV |
2381 | if (!addr) |
2382 | return; | |
2383 | ||
2384 | arch_ftrace_set_direct_caller(regs, addr); | |
2385 | } | |
2386 | ||
2387 | struct ftrace_ops direct_ops = { | |
2388 | .func = call_direct_funcs, | |
2389 | .flags = FTRACE_OPS_FL_IPMODIFY | FTRACE_OPS_FL_RECURSION_SAFE | |
2390 | | FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_REGS | |
2391 | | FTRACE_OPS_FL_PERMANENT, | |
2392 | }; | |
763e34e7 SRV |
2393 | #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ |
2394 | ||
7413af1f SRRH |
2395 | /** |
2396 | * ftrace_get_addr_new - Get the call address to set to | |
2397 | * @rec: The ftrace record descriptor | |
2398 | * | |
2399 | * If the record has the FTRACE_FL_REGS set, that means that it | |
2400 | * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS | |
2401 | * is not not set, then it wants to convert to the normal callback. | |
2402 | * | |
2403 | * Returns the address of the trampoline to set to | |
2404 | */ | |
2405 | unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec) | |
2406 | { | |
79922b80 | 2407 | struct ftrace_ops *ops; |
763e34e7 SRV |
2408 | unsigned long addr; |
2409 | ||
2410 | if ((rec->flags & FTRACE_FL_DIRECT) && | |
2411 | (ftrace_rec_count(rec) == 1)) { | |
ff205766 | 2412 | addr = ftrace_find_rec_direct(rec->ip); |
763e34e7 SRV |
2413 | if (addr) |
2414 | return addr; | |
2415 | WARN_ON_ONCE(1); | |
2416 | } | |
79922b80 SRRH |
2417 | |
2418 | /* Trampolines take precedence over regs */ | |
2419 | if (rec->flags & FTRACE_FL_TRAMP) { | |
2420 | ops = ftrace_find_tramp_ops_new(rec); | |
2421 | if (FTRACE_WARN_ON(!ops || !ops->trampoline)) { | |
bce0b6c5 SRRH |
2422 | pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n", |
2423 | (void *)rec->ip, (void *)rec->ip, rec->flags); | |
79922b80 SRRH |
2424 | /* Ftrace is shutting down, return anything */ |
2425 | return (unsigned long)FTRACE_ADDR; | |
2426 | } | |
2427 | return ops->trampoline; | |
2428 | } | |
2429 | ||
7413af1f SRRH |
2430 | if (rec->flags & FTRACE_FL_REGS) |
2431 | return (unsigned long)FTRACE_REGS_ADDR; | |
2432 | else | |
2433 | return (unsigned long)FTRACE_ADDR; | |
2434 | } | |
2435 | ||
2436 | /** | |
2437 | * ftrace_get_addr_curr - Get the call address that is already there | |
2438 | * @rec: The ftrace record descriptor | |
2439 | * | |
2440 | * The FTRACE_FL_REGS_EN is set when the record already points to | |
2441 | * a function that saves all the regs. Basically the '_EN' version | |
2442 | * represents the current state of the function. | |
2443 | * | |
2444 | * Returns the address of the trampoline that is currently being called | |
2445 | */ | |
2446 | unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec) | |
2447 | { | |
79922b80 | 2448 | struct ftrace_ops *ops; |
763e34e7 SRV |
2449 | unsigned long addr; |
2450 | ||
2451 | /* Direct calls take precedence over trampolines */ | |
2452 | if (rec->flags & FTRACE_FL_DIRECT_EN) { | |
ff205766 | 2453 | addr = ftrace_find_rec_direct(rec->ip); |
763e34e7 SRV |
2454 | if (addr) |
2455 | return addr; | |
2456 | WARN_ON_ONCE(1); | |
2457 | } | |
79922b80 SRRH |
2458 | |
2459 | /* Trampolines take precedence over regs */ | |
2460 | if (rec->flags & FTRACE_FL_TRAMP_EN) { | |
2461 | ops = ftrace_find_tramp_ops_curr(rec); | |
2462 | if (FTRACE_WARN_ON(!ops)) { | |
a395d6a7 JP |
2463 | pr_warn("Bad trampoline accounting at: %p (%pS)\n", |
2464 | (void *)rec->ip, (void *)rec->ip); | |
79922b80 SRRH |
2465 | /* Ftrace is shutting down, return anything */ |
2466 | return (unsigned long)FTRACE_ADDR; | |
2467 | } | |
2468 | return ops->trampoline; | |
2469 | } | |
2470 | ||
7413af1f SRRH |
2471 | if (rec->flags & FTRACE_FL_REGS_EN) |
2472 | return (unsigned long)FTRACE_REGS_ADDR; | |
2473 | else | |
2474 | return (unsigned long)FTRACE_ADDR; | |
2475 | } | |
2476 | ||
c88fd863 | 2477 | static int |
7375dca1 | 2478 | __ftrace_replace_code(struct dyn_ftrace *rec, bool enable) |
c88fd863 | 2479 | { |
08f6fba5 | 2480 | unsigned long ftrace_old_addr; |
c88fd863 SR |
2481 | unsigned long ftrace_addr; |
2482 | int ret; | |
2483 | ||
7c0868e0 | 2484 | ftrace_addr = ftrace_get_addr_new(rec); |
c88fd863 | 2485 | |
7c0868e0 SRRH |
2486 | /* This needs to be done before we call ftrace_update_record */ |
2487 | ftrace_old_addr = ftrace_get_addr_curr(rec); | |
2488 | ||
2489 | ret = ftrace_update_record(rec, enable); | |
08f6fba5 | 2490 | |
02a392a0 SRRH |
2491 | ftrace_bug_type = FTRACE_BUG_UNKNOWN; |
2492 | ||
c88fd863 SR |
2493 | switch (ret) { |
2494 | case FTRACE_UPDATE_IGNORE: | |
2495 | return 0; | |
2496 | ||
2497 | case FTRACE_UPDATE_MAKE_CALL: | |
02a392a0 | 2498 | ftrace_bug_type = FTRACE_BUG_CALL; |
64fbcd16 | 2499 | return ftrace_make_call(rec, ftrace_addr); |
c88fd863 SR |
2500 | |
2501 | case FTRACE_UPDATE_MAKE_NOP: | |
02a392a0 | 2502 | ftrace_bug_type = FTRACE_BUG_NOP; |
39b5552c | 2503 | return ftrace_make_nop(NULL, rec, ftrace_old_addr); |
08f6fba5 | 2504 | |
08f6fba5 | 2505 | case FTRACE_UPDATE_MODIFY_CALL: |
02a392a0 | 2506 | ftrace_bug_type = FTRACE_BUG_UPDATE; |
08f6fba5 | 2507 | return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr); |
5072c59f SR |
2508 | } |
2509 | ||
9efb85c5 | 2510 | return -1; /* unknown ftrace bug */ |
5072c59f SR |
2511 | } |
2512 | ||
a0572f68 | 2513 | void __weak ftrace_replace_code(int mod_flags) |
3c1720f0 | 2514 | { |
3c1720f0 SR |
2515 | struct dyn_ftrace *rec; |
2516 | struct ftrace_page *pg; | |
7375dca1 | 2517 | bool enable = mod_flags & FTRACE_MODIFY_ENABLE_FL; |
a0572f68 | 2518 | int schedulable = mod_flags & FTRACE_MODIFY_MAY_SLEEP_FL; |
6a24a244 | 2519 | int failed; |
3c1720f0 | 2520 | |
45a4a237 SR |
2521 | if (unlikely(ftrace_disabled)) |
2522 | return; | |
2523 | ||
265c831c | 2524 | do_for_each_ftrace_rec(pg, rec) { |
546fece4 SRRH |
2525 | |
2526 | if (rec->flags & FTRACE_FL_DISABLED) | |
2527 | continue; | |
2528 | ||
e4f5d544 | 2529 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 2530 | if (failed) { |
4fd3279b | 2531 | ftrace_bug(failed, rec); |
3279ba37 SR |
2532 | /* Stop processing */ |
2533 | return; | |
3c1720f0 | 2534 | } |
a0572f68 SRV |
2535 | if (schedulable) |
2536 | cond_resched(); | |
265c831c | 2537 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
2538 | } |
2539 | ||
c88fd863 SR |
2540 | struct ftrace_rec_iter { |
2541 | struct ftrace_page *pg; | |
2542 | int index; | |
2543 | }; | |
2544 | ||
2545 | /** | |
2546 | * ftrace_rec_iter_start, start up iterating over traced functions | |
2547 | * | |
2548 | * Returns an iterator handle that is used to iterate over all | |
2549 | * the records that represent address locations where functions | |
2550 | * are traced. | |
2551 | * | |
2552 | * May return NULL if no records are available. | |
2553 | */ | |
2554 | struct ftrace_rec_iter *ftrace_rec_iter_start(void) | |
2555 | { | |
2556 | /* | |
2557 | * We only use a single iterator. | |
2558 | * Protected by the ftrace_lock mutex. | |
2559 | */ | |
2560 | static struct ftrace_rec_iter ftrace_rec_iter; | |
2561 | struct ftrace_rec_iter *iter = &ftrace_rec_iter; | |
2562 | ||
2563 | iter->pg = ftrace_pages_start; | |
2564 | iter->index = 0; | |
2565 | ||
2566 | /* Could have empty pages */ | |
2567 | while (iter->pg && !iter->pg->index) | |
2568 | iter->pg = iter->pg->next; | |
2569 | ||
2570 | if (!iter->pg) | |
2571 | return NULL; | |
2572 | ||
2573 | return iter; | |
2574 | } | |
2575 | ||
2576 | /** | |
2577 | * ftrace_rec_iter_next, get the next record to process. | |
2578 | * @iter: The handle to the iterator. | |
2579 | * | |
2580 | * Returns the next iterator after the given iterator @iter. | |
2581 | */ | |
2582 | struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) | |
2583 | { | |
2584 | iter->index++; | |
2585 | ||
2586 | if (iter->index >= iter->pg->index) { | |
2587 | iter->pg = iter->pg->next; | |
2588 | iter->index = 0; | |
2589 | ||
2590 | /* Could have empty pages */ | |
2591 | while (iter->pg && !iter->pg->index) | |
2592 | iter->pg = iter->pg->next; | |
2593 | } | |
2594 | ||
2595 | if (!iter->pg) | |
2596 | return NULL; | |
2597 | ||
2598 | return iter; | |
2599 | } | |
2600 | ||
2601 | /** | |
2602 | * ftrace_rec_iter_record, get the record at the iterator location | |
2603 | * @iter: The current iterator location | |
2604 | * | |
2605 | * Returns the record that the current @iter is at. | |
2606 | */ | |
2607 | struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) | |
2608 | { | |
2609 | return &iter->pg->records[iter->index]; | |
2610 | } | |
2611 | ||
492a7ea5 | 2612 | static int |
fbf6c73c | 2613 | ftrace_nop_initialize(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 | 2614 | { |
593eb8a2 | 2615 | int ret; |
3c1720f0 | 2616 | |
45a4a237 SR |
2617 | if (unlikely(ftrace_disabled)) |
2618 | return 0; | |
2619 | ||
fbf6c73c | 2620 | ret = ftrace_init_nop(mod, rec); |
593eb8a2 | 2621 | if (ret) { |
02a392a0 | 2622 | ftrace_bug_type = FTRACE_BUG_INIT; |
4fd3279b | 2623 | ftrace_bug(ret, rec); |
492a7ea5 | 2624 | return 0; |
37ad5084 | 2625 | } |
492a7ea5 | 2626 | return 1; |
3c1720f0 SR |
2627 | } |
2628 | ||
000ab691 SR |
2629 | /* |
2630 | * archs can override this function if they must do something | |
2631 | * before the modifying code is performed. | |
2632 | */ | |
2633 | int __weak ftrace_arch_code_modify_prepare(void) | |
2634 | { | |
2635 | return 0; | |
2636 | } | |
2637 | ||
2638 | /* | |
2639 | * archs can override this function if they must do something | |
2640 | * after the modifying code is performed. | |
2641 | */ | |
2642 | int __weak ftrace_arch_code_modify_post_process(void) | |
2643 | { | |
2644 | return 0; | |
2645 | } | |
2646 | ||
8ed3e2cf | 2647 | void ftrace_modify_all_code(int command) |
3d083395 | 2648 | { |
59338f75 | 2649 | int update = command & FTRACE_UPDATE_TRACE_FUNC; |
a0572f68 | 2650 | int mod_flags = 0; |
cd21067f | 2651 | int err = 0; |
59338f75 | 2652 | |
a0572f68 SRV |
2653 | if (command & FTRACE_MAY_SLEEP) |
2654 | mod_flags = FTRACE_MODIFY_MAY_SLEEP_FL; | |
2655 | ||
59338f75 SRRH |
2656 | /* |
2657 | * If the ftrace_caller calls a ftrace_ops func directly, | |
2658 | * we need to make sure that it only traces functions it | |
2659 | * expects to trace. When doing the switch of functions, | |
2660 | * we need to update to the ftrace_ops_list_func first | |
2661 | * before the transition between old and new calls are set, | |
2662 | * as the ftrace_ops_list_func will check the ops hashes | |
2663 | * to make sure the ops are having the right functions | |
2664 | * traced. | |
2665 | */ | |
cd21067f PM |
2666 | if (update) { |
2667 | err = ftrace_update_ftrace_func(ftrace_ops_list_func); | |
2668 | if (FTRACE_WARN_ON(err)) | |
2669 | return; | |
2670 | } | |
59338f75 | 2671 | |
8ed3e2cf | 2672 | if (command & FTRACE_UPDATE_CALLS) |
a0572f68 | 2673 | ftrace_replace_code(mod_flags | FTRACE_MODIFY_ENABLE_FL); |
8ed3e2cf | 2674 | else if (command & FTRACE_DISABLE_CALLS) |
a0572f68 | 2675 | ftrace_replace_code(mod_flags); |
d61f82d0 | 2676 | |
405e1d83 SRRH |
2677 | if (update && ftrace_trace_function != ftrace_ops_list_func) { |
2678 | function_trace_op = set_function_trace_op; | |
2679 | smp_wmb(); | |
2680 | /* If irqs are disabled, we are in stop machine */ | |
2681 | if (!irqs_disabled()) | |
2682 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
cd21067f PM |
2683 | err = ftrace_update_ftrace_func(ftrace_trace_function); |
2684 | if (FTRACE_WARN_ON(err)) | |
2685 | return; | |
405e1d83 | 2686 | } |
d61f82d0 | 2687 | |
8ed3e2cf | 2688 | if (command & FTRACE_START_FUNC_RET) |
cd21067f | 2689 | err = ftrace_enable_ftrace_graph_caller(); |
8ed3e2cf | 2690 | else if (command & FTRACE_STOP_FUNC_RET) |
cd21067f PM |
2691 | err = ftrace_disable_ftrace_graph_caller(); |
2692 | FTRACE_WARN_ON(err); | |
8ed3e2cf SR |
2693 | } |
2694 | ||
2695 | static int __ftrace_modify_code(void *data) | |
2696 | { | |
2697 | int *command = data; | |
2698 | ||
2699 | ftrace_modify_all_code(*command); | |
5a45cfe1 | 2700 | |
d61f82d0 | 2701 | return 0; |
3d083395 SR |
2702 | } |
2703 | ||
c88fd863 SR |
2704 | /** |
2705 | * ftrace_run_stop_machine, go back to the stop machine method | |
2706 | * @command: The command to tell ftrace what to do | |
2707 | * | |
2708 | * If an arch needs to fall back to the stop machine method, the | |
2709 | * it can call this function. | |
2710 | */ | |
2711 | void ftrace_run_stop_machine(int command) | |
2712 | { | |
2713 | stop_machine(__ftrace_modify_code, &command, NULL); | |
2714 | } | |
2715 | ||
2716 | /** | |
2717 | * arch_ftrace_update_code, modify the code to trace or not trace | |
2718 | * @command: The command that needs to be done | |
2719 | * | |
2720 | * Archs can override this function if it does not need to | |
2721 | * run stop_machine() to modify code. | |
2722 | */ | |
2723 | void __weak arch_ftrace_update_code(int command) | |
2724 | { | |
2725 | ftrace_run_stop_machine(command); | |
2726 | } | |
2727 | ||
e309b41d | 2728 | static void ftrace_run_update_code(int command) |
3d083395 | 2729 | { |
000ab691 SR |
2730 | int ret; |
2731 | ||
2732 | ret = ftrace_arch_code_modify_prepare(); | |
2733 | FTRACE_WARN_ON(ret); | |
2734 | if (ret) | |
d5b844a2 | 2735 | return; |
000ab691 | 2736 | |
c88fd863 SR |
2737 | /* |
2738 | * By default we use stop_machine() to modify the code. | |
2739 | * But archs can do what ever they want as long as it | |
2740 | * is safe. The stop_machine() is the safest, but also | |
2741 | * produces the most overhead. | |
2742 | */ | |
2743 | arch_ftrace_update_code(command); | |
2744 | ||
000ab691 SR |
2745 | ret = ftrace_arch_code_modify_post_process(); |
2746 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
2747 | } |
2748 | ||
8252ecf3 | 2749 | static void ftrace_run_modify_code(struct ftrace_ops *ops, int command, |
7485058e | 2750 | struct ftrace_ops_hash *old_hash) |
e1effa01 SRRH |
2751 | { |
2752 | ops->flags |= FTRACE_OPS_FL_MODIFYING; | |
7485058e SRRH |
2753 | ops->old_hash.filter_hash = old_hash->filter_hash; |
2754 | ops->old_hash.notrace_hash = old_hash->notrace_hash; | |
e1effa01 | 2755 | ftrace_run_update_code(command); |
8252ecf3 | 2756 | ops->old_hash.filter_hash = NULL; |
7485058e | 2757 | ops->old_hash.notrace_hash = NULL; |
e1effa01 SRRH |
2758 | ops->flags &= ~FTRACE_OPS_FL_MODIFYING; |
2759 | } | |
2760 | ||
d61f82d0 | 2761 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 2762 | static int ftrace_start_up; |
df4fc315 | 2763 | |
12cce594 SRRH |
2764 | void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops) |
2765 | { | |
2766 | } | |
2767 | ||
df4fc315 SR |
2768 | static void ftrace_startup_enable(int command) |
2769 | { | |
2770 | if (saved_ftrace_func != ftrace_trace_function) { | |
2771 | saved_ftrace_func = ftrace_trace_function; | |
2772 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2773 | } | |
2774 | ||
2775 | if (!command || !ftrace_enabled) | |
2776 | return; | |
2777 | ||
2778 | ftrace_run_update_code(command); | |
2779 | } | |
d61f82d0 | 2780 | |
e1effa01 SRRH |
2781 | static void ftrace_startup_all(int command) |
2782 | { | |
2783 | update_all_ops = true; | |
2784 | ftrace_startup_enable(command); | |
2785 | update_all_ops = false; | |
2786 | } | |
2787 | ||
3306fc4a | 2788 | int ftrace_startup(struct ftrace_ops *ops, int command) |
3d083395 | 2789 | { |
8a56d776 | 2790 | int ret; |
b848914c | 2791 | |
4eebcc81 | 2792 | if (unlikely(ftrace_disabled)) |
a1cd6173 | 2793 | return -ENODEV; |
4eebcc81 | 2794 | |
8a56d776 SRRH |
2795 | ret = __register_ftrace_function(ops); |
2796 | if (ret) | |
2797 | return ret; | |
2798 | ||
60a7ecf4 | 2799 | ftrace_start_up++; |
d61f82d0 | 2800 | |
e1effa01 SRRH |
2801 | /* |
2802 | * Note that ftrace probes uses this to start up | |
2803 | * and modify functions it will probe. But we still | |
2804 | * set the ADDING flag for modification, as probes | |
2805 | * do not have trampolines. If they add them in the | |
2806 | * future, then the probes will need to distinguish | |
2807 | * between adding and updating probes. | |
2808 | */ | |
2809 | ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING; | |
66209a5b | 2810 | |
f8b8be8a MH |
2811 | ret = ftrace_hash_ipmodify_enable(ops); |
2812 | if (ret < 0) { | |
2813 | /* Rollback registration process */ | |
2814 | __unregister_ftrace_function(ops); | |
2815 | ftrace_start_up--; | |
2816 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; | |
2817 | return ret; | |
2818 | } | |
2819 | ||
7f50d06b JO |
2820 | if (ftrace_hash_rec_enable(ops, 1)) |
2821 | command |= FTRACE_UPDATE_CALLS; | |
ed926f9b | 2822 | |
df4fc315 | 2823 | ftrace_startup_enable(command); |
a1cd6173 | 2824 | |
e1effa01 SRRH |
2825 | ops->flags &= ~FTRACE_OPS_FL_ADDING; |
2826 | ||
a1cd6173 | 2827 | return 0; |
3d083395 SR |
2828 | } |
2829 | ||
3306fc4a | 2830 | int ftrace_shutdown(struct ftrace_ops *ops, int command) |
3d083395 | 2831 | { |
8a56d776 | 2832 | int ret; |
b848914c | 2833 | |
4eebcc81 | 2834 | if (unlikely(ftrace_disabled)) |
8a56d776 SRRH |
2835 | return -ENODEV; |
2836 | ||
2837 | ret = __unregister_ftrace_function(ops); | |
2838 | if (ret) | |
2839 | return ret; | |
4eebcc81 | 2840 | |
60a7ecf4 | 2841 | ftrace_start_up--; |
9ea1a153 FW |
2842 | /* |
2843 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
2844 | * critical but the ftrace_call callers may be never nopped again after | |
2845 | * further ftrace uses. | |
2846 | */ | |
2847 | WARN_ON_ONCE(ftrace_start_up < 0); | |
2848 | ||
f8b8be8a MH |
2849 | /* Disabling ipmodify never fails */ |
2850 | ftrace_hash_ipmodify_disable(ops); | |
ed926f9b | 2851 | |
7f50d06b JO |
2852 | if (ftrace_hash_rec_disable(ops, 1)) |
2853 | command |= FTRACE_UPDATE_CALLS; | |
b848914c | 2854 | |
7f50d06b | 2855 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
3d083395 | 2856 | |
d61f82d0 SR |
2857 | if (saved_ftrace_func != ftrace_trace_function) { |
2858 | saved_ftrace_func = ftrace_trace_function; | |
2859 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2860 | } | |
3d083395 | 2861 | |
a4c35ed2 SRRH |
2862 | if (!command || !ftrace_enabled) { |
2863 | /* | |
edb096e0 SRV |
2864 | * If these are dynamic or per_cpu ops, they still |
2865 | * need their data freed. Since, function tracing is | |
a4c35ed2 SRRH |
2866 | * not currently active, we can just free them |
2867 | * without synchronizing all CPUs. | |
2868 | */ | |
b3a88803 | 2869 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC) |
edb096e0 SRV |
2870 | goto free_ops; |
2871 | ||
8a56d776 | 2872 | return 0; |
a4c35ed2 | 2873 | } |
d61f82d0 | 2874 | |
79922b80 SRRH |
2875 | /* |
2876 | * If the ops uses a trampoline, then it needs to be | |
2877 | * tested first on update. | |
2878 | */ | |
e1effa01 | 2879 | ops->flags |= FTRACE_OPS_FL_REMOVING; |
79922b80 SRRH |
2880 | removed_ops = ops; |
2881 | ||
fef5aeee SRRH |
2882 | /* The trampoline logic checks the old hashes */ |
2883 | ops->old_hash.filter_hash = ops->func_hash->filter_hash; | |
2884 | ops->old_hash.notrace_hash = ops->func_hash->notrace_hash; | |
2885 | ||
d61f82d0 | 2886 | ftrace_run_update_code(command); |
a4c35ed2 | 2887 | |
84bde62c SRRH |
2888 | /* |
2889 | * If there's no more ops registered with ftrace, run a | |
2890 | * sanity check to make sure all rec flags are cleared. | |
2891 | */ | |
f86f4180 CZ |
2892 | if (rcu_dereference_protected(ftrace_ops_list, |
2893 | lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) { | |
84bde62c SRRH |
2894 | struct ftrace_page *pg; |
2895 | struct dyn_ftrace *rec; | |
2896 | ||
2897 | do_for_each_ftrace_rec(pg, rec) { | |
977c1f9c | 2898 | if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_FL_DISABLED)) |
84bde62c SRRH |
2899 | pr_warn(" %pS flags:%lx\n", |
2900 | (void *)rec->ip, rec->flags); | |
2901 | } while_for_each_ftrace_rec(); | |
2902 | } | |
2903 | ||
fef5aeee SRRH |
2904 | ops->old_hash.filter_hash = NULL; |
2905 | ops->old_hash.notrace_hash = NULL; | |
2906 | ||
2907 | removed_ops = NULL; | |
e1effa01 | 2908 | ops->flags &= ~FTRACE_OPS_FL_REMOVING; |
79922b80 | 2909 | |
a4c35ed2 SRRH |
2910 | /* |
2911 | * Dynamic ops may be freed, we must make sure that all | |
2912 | * callers are done before leaving this function. | |
ba27f2bc | 2913 | * The same goes for freeing the per_cpu data of the per_cpu |
a4c35ed2 | 2914 | * ops. |
a4c35ed2 | 2915 | */ |
b3a88803 | 2916 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC) { |
0598e4f0 SRV |
2917 | /* |
2918 | * We need to do a hard force of sched synchronization. | |
2919 | * This is because we use preempt_disable() to do RCU, but | |
2920 | * the function tracers can be called where RCU is not watching | |
2921 | * (like before user_exit()). We can not rely on the RCU | |
2922 | * infrastructure to do the synchronization, thus we must do it | |
2923 | * ourselves. | |
2924 | */ | |
a4c35ed2 SRRH |
2925 | schedule_on_each_cpu(ftrace_sync); |
2926 | ||
0598e4f0 SRV |
2927 | /* |
2928 | * When the kernel is preeptive, tasks can be preempted | |
2929 | * while on a ftrace trampoline. Just scheduling a task on | |
2930 | * a CPU is not good enough to flush them. Calling | |
2931 | * synchornize_rcu_tasks() will wait for those tasks to | |
2932 | * execute and either schedule voluntarily or enter user space. | |
2933 | */ | |
30c93704 | 2934 | if (IS_ENABLED(CONFIG_PREEMPTION)) |
0598e4f0 SRV |
2935 | synchronize_rcu_tasks(); |
2936 | ||
edb096e0 | 2937 | free_ops: |
12cce594 | 2938 | arch_ftrace_trampoline_free(ops); |
a4c35ed2 SRRH |
2939 | } |
2940 | ||
8a56d776 | 2941 | return 0; |
3d083395 SR |
2942 | } |
2943 | ||
e309b41d | 2944 | static void ftrace_startup_sysctl(void) |
b0fc494f | 2945 | { |
1619dc3f PA |
2946 | int command; |
2947 | ||
4eebcc81 SR |
2948 | if (unlikely(ftrace_disabled)) |
2949 | return; | |
2950 | ||
d61f82d0 SR |
2951 | /* Force update next time */ |
2952 | saved_ftrace_func = NULL; | |
60a7ecf4 | 2953 | /* ftrace_start_up is true if we want ftrace running */ |
1619dc3f PA |
2954 | if (ftrace_start_up) { |
2955 | command = FTRACE_UPDATE_CALLS; | |
2956 | if (ftrace_graph_active) | |
2957 | command |= FTRACE_START_FUNC_RET; | |
524a3868 | 2958 | ftrace_startup_enable(command); |
1619dc3f | 2959 | } |
b0fc494f SR |
2960 | } |
2961 | ||
e309b41d | 2962 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 2963 | { |
1619dc3f PA |
2964 | int command; |
2965 | ||
4eebcc81 SR |
2966 | if (unlikely(ftrace_disabled)) |
2967 | return; | |
2968 | ||
60a7ecf4 | 2969 | /* ftrace_start_up is true if ftrace is running */ |
1619dc3f PA |
2970 | if (ftrace_start_up) { |
2971 | command = FTRACE_DISABLE_CALLS; | |
2972 | if (ftrace_graph_active) | |
2973 | command |= FTRACE_STOP_FUNC_RET; | |
2974 | ftrace_run_update_code(command); | |
2975 | } | |
b0fc494f SR |
2976 | } |
2977 | ||
a5a1d1c2 | 2978 | static u64 ftrace_update_time; |
3d083395 | 2979 | unsigned long ftrace_update_tot_cnt; |
da537f0a SRV |
2980 | unsigned long ftrace_number_of_pages; |
2981 | unsigned long ftrace_number_of_groups; | |
3d083395 | 2982 | |
8c4f3c3f | 2983 | static inline int ops_traces_mod(struct ftrace_ops *ops) |
f7bc8b61 | 2984 | { |
8c4f3c3f SRRH |
2985 | /* |
2986 | * Filter_hash being empty will default to trace module. | |
2987 | * But notrace hash requires a test of individual module functions. | |
2988 | */ | |
33b7f99c SRRH |
2989 | return ftrace_hash_empty(ops->func_hash->filter_hash) && |
2990 | ftrace_hash_empty(ops->func_hash->notrace_hash); | |
8c4f3c3f SRRH |
2991 | } |
2992 | ||
2993 | /* | |
2994 | * Check if the current ops references the record. | |
2995 | * | |
2996 | * If the ops traces all functions, then it was already accounted for. | |
2997 | * If the ops does not trace the current record function, skip it. | |
2998 | * If the ops ignores the function via notrace filter, skip it. | |
2999 | */ | |
3000 | static inline bool | |
3001 | ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec) | |
3002 | { | |
3003 | /* If ops isn't enabled, ignore it */ | |
3004 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
44ec3ec0 | 3005 | return false; |
8c4f3c3f | 3006 | |
b7ffffbb | 3007 | /* If ops traces all then it includes this function */ |
8c4f3c3f | 3008 | if (ops_traces_mod(ops)) |
44ec3ec0 | 3009 | return true; |
8c4f3c3f SRRH |
3010 | |
3011 | /* The function must be in the filter */ | |
33b7f99c | 3012 | if (!ftrace_hash_empty(ops->func_hash->filter_hash) && |
2b2c279c | 3013 | !__ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip)) |
44ec3ec0 | 3014 | return false; |
f7bc8b61 | 3015 | |
8c4f3c3f | 3016 | /* If in notrace hash, we ignore it too */ |
33b7f99c | 3017 | if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip)) |
44ec3ec0 | 3018 | return false; |
8c4f3c3f | 3019 | |
44ec3ec0 | 3020 | return true; |
8c4f3c3f SRRH |
3021 | } |
3022 | ||
1dc43cf0 | 3023 | static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs) |
3d083395 | 3024 | { |
85ae32ae | 3025 | struct ftrace_page *pg; |
e94142a6 | 3026 | struct dyn_ftrace *p; |
a5a1d1c2 | 3027 | u64 start, stop; |
1dc43cf0 | 3028 | unsigned long update_cnt = 0; |
b7ffffbb | 3029 | unsigned long rec_flags = 0; |
85ae32ae | 3030 | int i; |
f7bc8b61 | 3031 | |
b7ffffbb SRRH |
3032 | start = ftrace_now(raw_smp_processor_id()); |
3033 | ||
f7bc8b61 | 3034 | /* |
b7ffffbb SRRH |
3035 | * When a module is loaded, this function is called to convert |
3036 | * the calls to mcount in its text to nops, and also to create | |
3037 | * an entry in the ftrace data. Now, if ftrace is activated | |
3038 | * after this call, but before the module sets its text to | |
3039 | * read-only, the modification of enabling ftrace can fail if | |
3040 | * the read-only is done while ftrace is converting the calls. | |
3041 | * To prevent this, the module's records are set as disabled | |
3042 | * and will be enabled after the call to set the module's text | |
3043 | * to read-only. | |
f7bc8b61 | 3044 | */ |
b7ffffbb SRRH |
3045 | if (mod) |
3046 | rec_flags |= FTRACE_FL_DISABLED; | |
3d083395 | 3047 | |
1dc43cf0 | 3048 | for (pg = new_pgs; pg; pg = pg->next) { |
3d083395 | 3049 | |
85ae32ae | 3050 | for (i = 0; i < pg->index; i++) { |
8c4f3c3f | 3051 | |
85ae32ae SR |
3052 | /* If something went wrong, bail without enabling anything */ |
3053 | if (unlikely(ftrace_disabled)) | |
3054 | return -1; | |
f22f9a89 | 3055 | |
85ae32ae | 3056 | p = &pg->records[i]; |
b7ffffbb | 3057 | p->flags = rec_flags; |
f22f9a89 | 3058 | |
85ae32ae SR |
3059 | /* |
3060 | * Do the initial record conversion from mcount jump | |
3061 | * to the NOP instructions. | |
3062 | */ | |
cbdaeaf0 | 3063 | if (!__is_defined(CC_USING_NOP_MCOUNT) && |
fbf6c73c | 3064 | !ftrace_nop_initialize(mod, p)) |
85ae32ae | 3065 | break; |
5cb084bb | 3066 | |
1dc43cf0 | 3067 | update_cnt++; |
5cb084bb | 3068 | } |
3d083395 SR |
3069 | } |
3070 | ||
750ed1a4 | 3071 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 | 3072 | ftrace_update_time = stop - start; |
1dc43cf0 | 3073 | ftrace_update_tot_cnt += update_cnt; |
3d083395 | 3074 | |
16444a8a ACM |
3075 | return 0; |
3076 | } | |
3077 | ||
a7900875 | 3078 | static int ftrace_allocate_records(struct ftrace_page *pg, int count) |
3c1720f0 | 3079 | { |
a7900875 | 3080 | int order; |
3c1720f0 | 3081 | int cnt; |
3c1720f0 | 3082 | |
a7900875 SR |
3083 | if (WARN_ON(!count)) |
3084 | return -EINVAL; | |
3085 | ||
3086 | order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE)); | |
3c1720f0 SR |
3087 | |
3088 | /* | |
a7900875 SR |
3089 | * We want to fill as much as possible. No more than a page |
3090 | * may be empty. | |
3c1720f0 | 3091 | */ |
a7900875 SR |
3092 | while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE) |
3093 | order--; | |
3c1720f0 | 3094 | |
a7900875 SR |
3095 | again: |
3096 | pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order); | |
3c1720f0 | 3097 | |
a7900875 SR |
3098 | if (!pg->records) { |
3099 | /* if we can't allocate this size, try something smaller */ | |
3100 | if (!order) | |
3101 | return -ENOMEM; | |
3102 | order >>= 1; | |
3103 | goto again; | |
3104 | } | |
3c1720f0 | 3105 | |
da537f0a SRV |
3106 | ftrace_number_of_pages += 1 << order; |
3107 | ftrace_number_of_groups++; | |
3108 | ||
a7900875 SR |
3109 | cnt = (PAGE_SIZE << order) / ENTRY_SIZE; |
3110 | pg->size = cnt; | |
3c1720f0 | 3111 | |
a7900875 SR |
3112 | if (cnt > count) |
3113 | cnt = count; | |
3114 | ||
3115 | return cnt; | |
3116 | } | |
3117 | ||
3118 | static struct ftrace_page * | |
3119 | ftrace_allocate_pages(unsigned long num_to_init) | |
3120 | { | |
3121 | struct ftrace_page *start_pg; | |
3122 | struct ftrace_page *pg; | |
3123 | int order; | |
3124 | int cnt; | |
3125 | ||
3126 | if (!num_to_init) | |
9efb85c5 | 3127 | return NULL; |
a7900875 SR |
3128 | |
3129 | start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL); | |
3130 | if (!pg) | |
3131 | return NULL; | |
3132 | ||
3133 | /* | |
3134 | * Try to allocate as much as possible in one continues | |
3135 | * location that fills in all of the space. We want to | |
3136 | * waste as little space as possible. | |
3137 | */ | |
3138 | for (;;) { | |
3139 | cnt = ftrace_allocate_records(pg, num_to_init); | |
3140 | if (cnt < 0) | |
3141 | goto free_pages; | |
3142 | ||
3143 | num_to_init -= cnt; | |
3144 | if (!num_to_init) | |
3c1720f0 SR |
3145 | break; |
3146 | ||
a7900875 SR |
3147 | pg->next = kzalloc(sizeof(*pg), GFP_KERNEL); |
3148 | if (!pg->next) | |
3149 | goto free_pages; | |
3150 | ||
3c1720f0 SR |
3151 | pg = pg->next; |
3152 | } | |
3153 | ||
a7900875 SR |
3154 | return start_pg; |
3155 | ||
3156 | free_pages: | |
1f61be00 NK |
3157 | pg = start_pg; |
3158 | while (pg) { | |
a7900875 SR |
3159 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
3160 | free_pages((unsigned long)pg->records, order); | |
3161 | start_pg = pg->next; | |
3162 | kfree(pg); | |
3163 | pg = start_pg; | |
da537f0a SRV |
3164 | ftrace_number_of_pages -= 1 << order; |
3165 | ftrace_number_of_groups--; | |
a7900875 SR |
3166 | } |
3167 | pr_info("ftrace: FAILED to allocate memory for functions\n"); | |
3168 | return NULL; | |
3169 | } | |
3170 | ||
5072c59f SR |
3171 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ |
3172 | ||
3173 | struct ftrace_iterator { | |
98c4fd04 | 3174 | loff_t pos; |
4aeb6967 | 3175 | loff_t func_pos; |
5985ea8b | 3176 | loff_t mod_pos; |
4aeb6967 SR |
3177 | struct ftrace_page *pg; |
3178 | struct dyn_ftrace *func; | |
3179 | struct ftrace_func_probe *probe; | |
eee8ded1 | 3180 | struct ftrace_func_entry *probe_entry; |
4aeb6967 | 3181 | struct trace_parser parser; |
1cf41dd7 | 3182 | struct ftrace_hash *hash; |
33dc9b12 | 3183 | struct ftrace_ops *ops; |
5985ea8b SRV |
3184 | struct trace_array *tr; |
3185 | struct list_head *mod_list; | |
eee8ded1 | 3186 | int pidx; |
4aeb6967 SR |
3187 | int idx; |
3188 | unsigned flags; | |
5072c59f SR |
3189 | }; |
3190 | ||
8fc0c701 | 3191 | static void * |
eee8ded1 | 3192 | t_probe_next(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
3193 | { |
3194 | struct ftrace_iterator *iter = m->private; | |
d2afd57a | 3195 | struct trace_array *tr = iter->ops->private; |
04ec7bb6 | 3196 | struct list_head *func_probes; |
eee8ded1 SRV |
3197 | struct ftrace_hash *hash; |
3198 | struct list_head *next; | |
4aeb6967 | 3199 | struct hlist_node *hnd = NULL; |
8fc0c701 | 3200 | struct hlist_head *hhd; |
eee8ded1 | 3201 | int size; |
8fc0c701 | 3202 | |
8fc0c701 | 3203 | (*pos)++; |
98c4fd04 | 3204 | iter->pos = *pos; |
8fc0c701 | 3205 | |
04ec7bb6 | 3206 | if (!tr) |
8fc0c701 SR |
3207 | return NULL; |
3208 | ||
04ec7bb6 SRV |
3209 | func_probes = &tr->func_probes; |
3210 | if (list_empty(func_probes)) | |
8fc0c701 SR |
3211 | return NULL; |
3212 | ||
eee8ded1 | 3213 | if (!iter->probe) { |
04ec7bb6 | 3214 | next = func_probes->next; |
7b60f3d8 | 3215 | iter->probe = list_entry(next, struct ftrace_func_probe, list); |
eee8ded1 SRV |
3216 | } |
3217 | ||
3218 | if (iter->probe_entry) | |
3219 | hnd = &iter->probe_entry->hlist; | |
3220 | ||
3221 | hash = iter->probe->ops.func_hash->filter_hash; | |
7bd46644 | 3222 | |
372e0d01 SRV |
3223 | /* |
3224 | * A probe being registered may temporarily have an empty hash | |
3225 | * and it's at the end of the func_probes list. | |
3226 | */ | |
3227 | if (!hash || hash == EMPTY_HASH) | |
7bd46644 NR |
3228 | return NULL; |
3229 | ||
eee8ded1 SRV |
3230 | size = 1 << hash->size_bits; |
3231 | ||
3232 | retry: | |
3233 | if (iter->pidx >= size) { | |
04ec7bb6 | 3234 | if (iter->probe->list.next == func_probes) |
eee8ded1 SRV |
3235 | return NULL; |
3236 | next = iter->probe->list.next; | |
7b60f3d8 | 3237 | iter->probe = list_entry(next, struct ftrace_func_probe, list); |
eee8ded1 SRV |
3238 | hash = iter->probe->ops.func_hash->filter_hash; |
3239 | size = 1 << hash->size_bits; | |
3240 | iter->pidx = 0; | |
3241 | } | |
3242 | ||
3243 | hhd = &hash->buckets[iter->pidx]; | |
8fc0c701 SR |
3244 | |
3245 | if (hlist_empty(hhd)) { | |
eee8ded1 | 3246 | iter->pidx++; |
8fc0c701 SR |
3247 | hnd = NULL; |
3248 | goto retry; | |
3249 | } | |
3250 | ||
3251 | if (!hnd) | |
3252 | hnd = hhd->first; | |
3253 | else { | |
3254 | hnd = hnd->next; | |
3255 | if (!hnd) { | |
eee8ded1 | 3256 | iter->pidx++; |
8fc0c701 SR |
3257 | goto retry; |
3258 | } | |
3259 | } | |
3260 | ||
4aeb6967 SR |
3261 | if (WARN_ON_ONCE(!hnd)) |
3262 | return NULL; | |
3263 | ||
eee8ded1 | 3264 | iter->probe_entry = hlist_entry(hnd, struct ftrace_func_entry, hlist); |
4aeb6967 SR |
3265 | |
3266 | return iter; | |
8fc0c701 SR |
3267 | } |
3268 | ||
eee8ded1 | 3269 | static void *t_probe_start(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
3270 | { |
3271 | struct ftrace_iterator *iter = m->private; | |
3272 | void *p = NULL; | |
d82d6244 LZ |
3273 | loff_t l; |
3274 | ||
eee8ded1 | 3275 | if (!(iter->flags & FTRACE_ITER_DO_PROBES)) |
69a3083c SR |
3276 | return NULL; |
3277 | ||
5985ea8b | 3278 | if (iter->mod_pos > *pos) |
2bccfffd | 3279 | return NULL; |
8fc0c701 | 3280 | |
eee8ded1 SRV |
3281 | iter->probe = NULL; |
3282 | iter->probe_entry = NULL; | |
3283 | iter->pidx = 0; | |
5985ea8b | 3284 | for (l = 0; l <= (*pos - iter->mod_pos); ) { |
eee8ded1 | 3285 | p = t_probe_next(m, &l); |
d82d6244 LZ |
3286 | if (!p) |
3287 | break; | |
3288 | } | |
4aeb6967 SR |
3289 | if (!p) |
3290 | return NULL; | |
3291 | ||
98c4fd04 | 3292 | /* Only set this if we have an item */ |
eee8ded1 | 3293 | iter->flags |= FTRACE_ITER_PROBE; |
98c4fd04 | 3294 | |
4aeb6967 | 3295 | return iter; |
8fc0c701 SR |
3296 | } |
3297 | ||
4aeb6967 | 3298 | static int |
eee8ded1 | 3299 | t_probe_show(struct seq_file *m, struct ftrace_iterator *iter) |
8fc0c701 | 3300 | { |
eee8ded1 | 3301 | struct ftrace_func_entry *probe_entry; |
7b60f3d8 SRV |
3302 | struct ftrace_probe_ops *probe_ops; |
3303 | struct ftrace_func_probe *probe; | |
8fc0c701 | 3304 | |
eee8ded1 SRV |
3305 | probe = iter->probe; |
3306 | probe_entry = iter->probe_entry; | |
8fc0c701 | 3307 | |
eee8ded1 | 3308 | if (WARN_ON_ONCE(!probe || !probe_entry)) |
4aeb6967 | 3309 | return -EIO; |
8fc0c701 | 3310 | |
7b60f3d8 | 3311 | probe_ops = probe->probe_ops; |
809dcf29 | 3312 | |
7b60f3d8 | 3313 | if (probe_ops->print) |
6e444319 | 3314 | return probe_ops->print(m, probe_entry->ip, probe_ops, probe->data); |
8fc0c701 | 3315 | |
7b60f3d8 SRV |
3316 | seq_printf(m, "%ps:%ps\n", (void *)probe_entry->ip, |
3317 | (void *)probe_ops->func); | |
8fc0c701 SR |
3318 | |
3319 | return 0; | |
3320 | } | |
3321 | ||
5985ea8b SRV |
3322 | static void * |
3323 | t_mod_next(struct seq_file *m, loff_t *pos) | |
3324 | { | |
3325 | struct ftrace_iterator *iter = m->private; | |
3326 | struct trace_array *tr = iter->tr; | |
3327 | ||
3328 | (*pos)++; | |
3329 | iter->pos = *pos; | |
3330 | ||
3331 | iter->mod_list = iter->mod_list->next; | |
3332 | ||
3333 | if (iter->mod_list == &tr->mod_trace || | |
3334 | iter->mod_list == &tr->mod_notrace) { | |
3335 | iter->flags &= ~FTRACE_ITER_MOD; | |
3336 | return NULL; | |
3337 | } | |
3338 | ||
3339 | iter->mod_pos = *pos; | |
3340 | ||
3341 | return iter; | |
3342 | } | |
3343 | ||
3344 | static void *t_mod_start(struct seq_file *m, loff_t *pos) | |
3345 | { | |
3346 | struct ftrace_iterator *iter = m->private; | |
3347 | void *p = NULL; | |
3348 | loff_t l; | |
3349 | ||
3350 | if (iter->func_pos > *pos) | |
3351 | return NULL; | |
3352 | ||
3353 | iter->mod_pos = iter->func_pos; | |
3354 | ||
3355 | /* probes are only available if tr is set */ | |
3356 | if (!iter->tr) | |
3357 | return NULL; | |
3358 | ||
3359 | for (l = 0; l <= (*pos - iter->func_pos); ) { | |
3360 | p = t_mod_next(m, &l); | |
3361 | if (!p) | |
3362 | break; | |
3363 | } | |
3364 | if (!p) { | |
3365 | iter->flags &= ~FTRACE_ITER_MOD; | |
3366 | return t_probe_start(m, pos); | |
3367 | } | |
3368 | ||
3369 | /* Only set this if we have an item */ | |
3370 | iter->flags |= FTRACE_ITER_MOD; | |
3371 | ||
3372 | return iter; | |
3373 | } | |
3374 | ||
3375 | static int | |
3376 | t_mod_show(struct seq_file *m, struct ftrace_iterator *iter) | |
3377 | { | |
3378 | struct ftrace_mod_load *ftrace_mod; | |
3379 | struct trace_array *tr = iter->tr; | |
3380 | ||
3381 | if (WARN_ON_ONCE(!iter->mod_list) || | |
3382 | iter->mod_list == &tr->mod_trace || | |
3383 | iter->mod_list == &tr->mod_notrace) | |
3384 | return -EIO; | |
3385 | ||
3386 | ftrace_mod = list_entry(iter->mod_list, struct ftrace_mod_load, list); | |
3387 | ||
3388 | if (ftrace_mod->func) | |
3389 | seq_printf(m, "%s", ftrace_mod->func); | |
3390 | else | |
3391 | seq_putc(m, '*'); | |
3392 | ||
3393 | seq_printf(m, ":mod:%s\n", ftrace_mod->module); | |
3394 | ||
3395 | return 0; | |
3396 | } | |
3397 | ||
e309b41d | 3398 | static void * |
5bd84629 | 3399 | t_func_next(struct seq_file *m, loff_t *pos) |
5072c59f SR |
3400 | { |
3401 | struct ftrace_iterator *iter = m->private; | |
3402 | struct dyn_ftrace *rec = NULL; | |
3403 | ||
3404 | (*pos)++; | |
0c75a3ed | 3405 | |
5072c59f SR |
3406 | retry: |
3407 | if (iter->idx >= iter->pg->index) { | |
3408 | if (iter->pg->next) { | |
3409 | iter->pg = iter->pg->next; | |
3410 | iter->idx = 0; | |
3411 | goto retry; | |
3412 | } | |
3413 | } else { | |
3414 | rec = &iter->pg->records[iter->idx++]; | |
c20489da SRV |
3415 | if (((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) && |
3416 | !ftrace_lookup_ip(iter->hash, rec->ip)) || | |
647bcd03 SR |
3417 | |
3418 | ((iter->flags & FTRACE_ITER_ENABLED) && | |
23ea9c4d | 3419 | !(rec->flags & FTRACE_FL_ENABLED))) { |
647bcd03 | 3420 | |
5072c59f SR |
3421 | rec = NULL; |
3422 | goto retry; | |
3423 | } | |
3424 | } | |
3425 | ||
4aeb6967 | 3426 | if (!rec) |
5bd84629 | 3427 | return NULL; |
4aeb6967 | 3428 | |
5bd84629 | 3429 | iter->pos = iter->func_pos = *pos; |
4aeb6967 SR |
3430 | iter->func = rec; |
3431 | ||
3432 | return iter; | |
5072c59f SR |
3433 | } |
3434 | ||
5bd84629 SRV |
3435 | static void * |
3436 | t_next(struct seq_file *m, void *v, loff_t *pos) | |
3437 | { | |
3438 | struct ftrace_iterator *iter = m->private; | |
5985ea8b | 3439 | loff_t l = *pos; /* t_probe_start() must use original pos */ |
5bd84629 SRV |
3440 | void *ret; |
3441 | ||
3442 | if (unlikely(ftrace_disabled)) | |
3443 | return NULL; | |
3444 | ||
eee8ded1 SRV |
3445 | if (iter->flags & FTRACE_ITER_PROBE) |
3446 | return t_probe_next(m, pos); | |
5bd84629 | 3447 | |
5985ea8b SRV |
3448 | if (iter->flags & FTRACE_ITER_MOD) |
3449 | return t_mod_next(m, pos); | |
3450 | ||
5bd84629 | 3451 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
eee8ded1 | 3452 | /* next must increment pos, and t_probe_start does not */ |
5bd84629 | 3453 | (*pos)++; |
5985ea8b | 3454 | return t_mod_start(m, &l); |
5bd84629 SRV |
3455 | } |
3456 | ||
3457 | ret = t_func_next(m, pos); | |
3458 | ||
3459 | if (!ret) | |
5985ea8b | 3460 | return t_mod_start(m, &l); |
5bd84629 SRV |
3461 | |
3462 | return ret; | |
3463 | } | |
3464 | ||
98c4fd04 SR |
3465 | static void reset_iter_read(struct ftrace_iterator *iter) |
3466 | { | |
3467 | iter->pos = 0; | |
3468 | iter->func_pos = 0; | |
5985ea8b | 3469 | iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_PROBE | FTRACE_ITER_MOD); |
5072c59f SR |
3470 | } |
3471 | ||
3472 | static void *t_start(struct seq_file *m, loff_t *pos) | |
3473 | { | |
3474 | struct ftrace_iterator *iter = m->private; | |
3475 | void *p = NULL; | |
694ce0a5 | 3476 | loff_t l; |
5072c59f | 3477 | |
8fc0c701 | 3478 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
3479 | |
3480 | if (unlikely(ftrace_disabled)) | |
3481 | return NULL; | |
3482 | ||
98c4fd04 SR |
3483 | /* |
3484 | * If an lseek was done, then reset and start from beginning. | |
3485 | */ | |
3486 | if (*pos < iter->pos) | |
3487 | reset_iter_read(iter); | |
3488 | ||
0c75a3ed SR |
3489 | /* |
3490 | * For set_ftrace_filter reading, if we have the filter | |
3491 | * off, we can short cut and just print out that all | |
3492 | * functions are enabled. | |
3493 | */ | |
c20489da SRV |
3494 | if ((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) && |
3495 | ftrace_hash_empty(iter->hash)) { | |
43ff926a | 3496 | iter->func_pos = 1; /* Account for the message */ |
0c75a3ed | 3497 | if (*pos > 0) |
5985ea8b | 3498 | return t_mod_start(m, pos); |
0c75a3ed | 3499 | iter->flags |= FTRACE_ITER_PRINTALL; |
df091625 | 3500 | /* reset in case of seek/pread */ |
eee8ded1 | 3501 | iter->flags &= ~FTRACE_ITER_PROBE; |
0c75a3ed SR |
3502 | return iter; |
3503 | } | |
3504 | ||
5985ea8b SRV |
3505 | if (iter->flags & FTRACE_ITER_MOD) |
3506 | return t_mod_start(m, pos); | |
8fc0c701 | 3507 | |
98c4fd04 SR |
3508 | /* |
3509 | * Unfortunately, we need to restart at ftrace_pages_start | |
3510 | * every time we let go of the ftrace_mutex. This is because | |
3511 | * those pointers can change without the lock. | |
3512 | */ | |
694ce0a5 LZ |
3513 | iter->pg = ftrace_pages_start; |
3514 | iter->idx = 0; | |
3515 | for (l = 0; l <= *pos; ) { | |
5bd84629 | 3516 | p = t_func_next(m, &l); |
694ce0a5 LZ |
3517 | if (!p) |
3518 | break; | |
50cdaf08 | 3519 | } |
5821e1b7 | 3520 | |
69a3083c | 3521 | if (!p) |
5985ea8b | 3522 | return t_mod_start(m, pos); |
4aeb6967 SR |
3523 | |
3524 | return iter; | |
5072c59f SR |
3525 | } |
3526 | ||
3527 | static void t_stop(struct seq_file *m, void *p) | |
3528 | { | |
8fc0c701 | 3529 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
3530 | } |
3531 | ||
15d5b02c SRRH |
3532 | void * __weak |
3533 | arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec) | |
3534 | { | |
3535 | return NULL; | |
3536 | } | |
3537 | ||
3538 | static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops, | |
3539 | struct dyn_ftrace *rec) | |
3540 | { | |
3541 | void *ptr; | |
3542 | ||
3543 | ptr = arch_ftrace_trampoline_func(ops, rec); | |
3544 | if (ptr) | |
3545 | seq_printf(m, " ->%pS", ptr); | |
3546 | } | |
3547 | ||
5072c59f SR |
3548 | static int t_show(struct seq_file *m, void *v) |
3549 | { | |
0c75a3ed | 3550 | struct ftrace_iterator *iter = m->private; |
4aeb6967 | 3551 | struct dyn_ftrace *rec; |
5072c59f | 3552 | |
eee8ded1 SRV |
3553 | if (iter->flags & FTRACE_ITER_PROBE) |
3554 | return t_probe_show(m, iter); | |
8fc0c701 | 3555 | |
5985ea8b SRV |
3556 | if (iter->flags & FTRACE_ITER_MOD) |
3557 | return t_mod_show(m, iter); | |
3558 | ||
0c75a3ed | 3559 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
8c006cf7 | 3560 | if (iter->flags & FTRACE_ITER_NOTRACE) |
fa6f0cc7 | 3561 | seq_puts(m, "#### no functions disabled ####\n"); |
8c006cf7 | 3562 | else |
fa6f0cc7 | 3563 | seq_puts(m, "#### all functions enabled ####\n"); |
0c75a3ed SR |
3564 | return 0; |
3565 | } | |
3566 | ||
4aeb6967 SR |
3567 | rec = iter->func; |
3568 | ||
5072c59f SR |
3569 | if (!rec) |
3570 | return 0; | |
3571 | ||
647bcd03 | 3572 | seq_printf(m, "%ps", (void *)rec->ip); |
9674b2fa | 3573 | if (iter->flags & FTRACE_ITER_ENABLED) { |
030f4e1c | 3574 | struct ftrace_ops *ops; |
15d5b02c | 3575 | |
763e34e7 | 3576 | seq_printf(m, " (%ld)%s%s%s", |
0376bde1 | 3577 | ftrace_rec_count(rec), |
f8b8be8a | 3578 | rec->flags & FTRACE_FL_REGS ? " R" : " ", |
763e34e7 SRV |
3579 | rec->flags & FTRACE_FL_IPMODIFY ? " I" : " ", |
3580 | rec->flags & FTRACE_FL_DIRECT ? " D" : " "); | |
9674b2fa | 3581 | if (rec->flags & FTRACE_FL_TRAMP_EN) { |
5fecaa04 | 3582 | ops = ftrace_find_tramp_ops_any(rec); |
39daa7b9 SRRH |
3583 | if (ops) { |
3584 | do { | |
3585 | seq_printf(m, "\ttramp: %pS (%pS)", | |
3586 | (void *)ops->trampoline, | |
3587 | (void *)ops->func); | |
030f4e1c | 3588 | add_trampoline_func(m, ops, rec); |
39daa7b9 SRRH |
3589 | ops = ftrace_find_tramp_ops_next(rec, ops); |
3590 | } while (ops); | |
3591 | } else | |
fa6f0cc7 | 3592 | seq_puts(m, "\ttramp: ERROR!"); |
030f4e1c SRRH |
3593 | } else { |
3594 | add_trampoline_func(m, NULL, rec); | |
9674b2fa | 3595 | } |
763e34e7 SRV |
3596 | if (rec->flags & FTRACE_FL_DIRECT) { |
3597 | unsigned long direct; | |
3598 | ||
ff205766 | 3599 | direct = ftrace_find_rec_direct(rec->ip); |
763e34e7 SRV |
3600 | if (direct) |
3601 | seq_printf(m, "\n\tdirect-->%pS", (void *)direct); | |
3602 | } | |
9674b2fa SRRH |
3603 | } |
3604 | ||
fa6f0cc7 | 3605 | seq_putc(m, '\n'); |
5072c59f SR |
3606 | |
3607 | return 0; | |
3608 | } | |
3609 | ||
88e9d34c | 3610 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
3611 | .start = t_start, |
3612 | .next = t_next, | |
3613 | .stop = t_stop, | |
3614 | .show = t_show, | |
3615 | }; | |
3616 | ||
e309b41d | 3617 | static int |
5072c59f SR |
3618 | ftrace_avail_open(struct inode *inode, struct file *file) |
3619 | { | |
3620 | struct ftrace_iterator *iter; | |
17911ff3 SRV |
3621 | int ret; |
3622 | ||
3623 | ret = security_locked_down(LOCKDOWN_TRACEFS); | |
3624 | if (ret) | |
3625 | return ret; | |
5072c59f | 3626 | |
4eebcc81 SR |
3627 | if (unlikely(ftrace_disabled)) |
3628 | return -ENODEV; | |
3629 | ||
50e18b94 | 3630 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
c1bc5919 SRV |
3631 | if (!iter) |
3632 | return -ENOMEM; | |
5072c59f | 3633 | |
c1bc5919 SRV |
3634 | iter->pg = ftrace_pages_start; |
3635 | iter->ops = &global_ops; | |
3636 | ||
3637 | return 0; | |
5072c59f SR |
3638 | } |
3639 | ||
647bcd03 SR |
3640 | static int |
3641 | ftrace_enabled_open(struct inode *inode, struct file *file) | |
3642 | { | |
3643 | struct ftrace_iterator *iter; | |
647bcd03 | 3644 | |
17911ff3 SRV |
3645 | /* |
3646 | * This shows us what functions are currently being | |
3647 | * traced and by what. Not sure if we want lockdown | |
3648 | * to hide such critical information for an admin. | |
3649 | * Although, perhaps it can show information we don't | |
3650 | * want people to see, but if something is tracing | |
3651 | * something, we probably want to know about it. | |
3652 | */ | |
3653 | ||
50e18b94 | 3654 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
c1bc5919 SRV |
3655 | if (!iter) |
3656 | return -ENOMEM; | |
647bcd03 | 3657 | |
c1bc5919 SRV |
3658 | iter->pg = ftrace_pages_start; |
3659 | iter->flags = FTRACE_ITER_ENABLED; | |
3660 | iter->ops = &global_ops; | |
3661 | ||
3662 | return 0; | |
647bcd03 SR |
3663 | } |
3664 | ||
fc13cb0c SR |
3665 | /** |
3666 | * ftrace_regex_open - initialize function tracer filter files | |
3667 | * @ops: The ftrace_ops that hold the hash filters | |
3668 | * @flag: The type of filter to process | |
3669 | * @inode: The inode, usually passed in to your open routine | |
3670 | * @file: The file, usually passed in to your open routine | |
3671 | * | |
3672 | * ftrace_regex_open() initializes the filter files for the | |
3673 | * @ops. Depending on @flag it may process the filter hash or | |
3674 | * the notrace hash of @ops. With this called from the open | |
3675 | * routine, you can use ftrace_filter_write() for the write | |
3676 | * routine if @flag has FTRACE_ITER_FILTER set, or | |
3677 | * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set. | |
098c879e | 3678 | * tracing_lseek() should be used as the lseek routine, and |
fc13cb0c SR |
3679 | * release must call ftrace_regex_release(). |
3680 | */ | |
3681 | int | |
f45948e8 | 3682 | ftrace_regex_open(struct ftrace_ops *ops, int flag, |
1cf41dd7 | 3683 | struct inode *inode, struct file *file) |
5072c59f SR |
3684 | { |
3685 | struct ftrace_iterator *iter; | |
f45948e8 | 3686 | struct ftrace_hash *hash; |
673feb9d SRV |
3687 | struct list_head *mod_head; |
3688 | struct trace_array *tr = ops->private; | |
9ef16693 | 3689 | int ret = -ENOMEM; |
5072c59f | 3690 | |
f04f24fb MH |
3691 | ftrace_ops_init(ops); |
3692 | ||
4eebcc81 SR |
3693 | if (unlikely(ftrace_disabled)) |
3694 | return -ENODEV; | |
3695 | ||
8530dec6 | 3696 | if (tracing_check_open_get_tr(tr)) |
9ef16693 SRV |
3697 | return -ENODEV; |
3698 | ||
5072c59f SR |
3699 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
3700 | if (!iter) | |
9ef16693 | 3701 | goto out; |
5072c59f | 3702 | |
9ef16693 SRV |
3703 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) |
3704 | goto out; | |
689fd8b6 | 3705 | |
3f2367ba MH |
3706 | iter->ops = ops; |
3707 | iter->flags = flag; | |
5985ea8b | 3708 | iter->tr = tr; |
3f2367ba | 3709 | |
33b7f99c | 3710 | mutex_lock(&ops->func_hash->regex_lock); |
3f2367ba | 3711 | |
673feb9d | 3712 | if (flag & FTRACE_ITER_NOTRACE) { |
33b7f99c | 3713 | hash = ops->func_hash->notrace_hash; |
5985ea8b | 3714 | mod_head = tr ? &tr->mod_notrace : NULL; |
673feb9d | 3715 | } else { |
33b7f99c | 3716 | hash = ops->func_hash->filter_hash; |
5985ea8b | 3717 | mod_head = tr ? &tr->mod_trace : NULL; |
673feb9d | 3718 | } |
f45948e8 | 3719 | |
5985ea8b SRV |
3720 | iter->mod_list = mod_head; |
3721 | ||
33dc9b12 | 3722 | if (file->f_mode & FMODE_WRITE) { |
ef2fbe16 NK |
3723 | const int size_bits = FTRACE_HASH_DEFAULT_BITS; |
3724 | ||
673feb9d | 3725 | if (file->f_flags & O_TRUNC) { |
ef2fbe16 | 3726 | iter->hash = alloc_ftrace_hash(size_bits); |
673feb9d SRV |
3727 | clear_ftrace_mod_list(mod_head); |
3728 | } else { | |
ef2fbe16 | 3729 | iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash); |
673feb9d | 3730 | } |
ef2fbe16 | 3731 | |
33dc9b12 SR |
3732 | if (!iter->hash) { |
3733 | trace_parser_put(&iter->parser); | |
3f2367ba | 3734 | goto out_unlock; |
33dc9b12 | 3735 | } |
c20489da SRV |
3736 | } else |
3737 | iter->hash = hash; | |
1cf41dd7 | 3738 | |
9ef16693 SRV |
3739 | ret = 0; |
3740 | ||
5072c59f SR |
3741 | if (file->f_mode & FMODE_READ) { |
3742 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
3743 | |
3744 | ret = seq_open(file, &show_ftrace_seq_ops); | |
3745 | if (!ret) { | |
3746 | struct seq_file *m = file->private_data; | |
3747 | m->private = iter; | |
79fe249c | 3748 | } else { |
33dc9b12 SR |
3749 | /* Failed */ |
3750 | free_ftrace_hash(iter->hash); | |
79fe249c | 3751 | trace_parser_put(&iter->parser); |
79fe249c | 3752 | } |
5072c59f SR |
3753 | } else |
3754 | file->private_data = iter; | |
3f2367ba MH |
3755 | |
3756 | out_unlock: | |
33b7f99c | 3757 | mutex_unlock(&ops->func_hash->regex_lock); |
5072c59f | 3758 | |
9ef16693 SRV |
3759 | out: |
3760 | if (ret) { | |
3761 | kfree(iter); | |
3762 | if (tr) | |
3763 | trace_array_put(tr); | |
3764 | } | |
3765 | ||
5072c59f SR |
3766 | return ret; |
3767 | } | |
3768 | ||
41c52c0d SR |
3769 | static int |
3770 | ftrace_filter_open(struct inode *inode, struct file *file) | |
3771 | { | |
e3b3e2e8 SRRH |
3772 | struct ftrace_ops *ops = inode->i_private; |
3773 | ||
17911ff3 | 3774 | /* Checks for tracefs lockdown */ |
e3b3e2e8 | 3775 | return ftrace_regex_open(ops, |
eee8ded1 | 3776 | FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES, |
69a3083c | 3777 | inode, file); |
41c52c0d SR |
3778 | } |
3779 | ||
3780 | static int | |
3781 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
3782 | { | |
e3b3e2e8 SRRH |
3783 | struct ftrace_ops *ops = inode->i_private; |
3784 | ||
17911ff3 | 3785 | /* Checks for tracefs lockdown */ |
e3b3e2e8 | 3786 | return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE, |
1cf41dd7 | 3787 | inode, file); |
41c52c0d SR |
3788 | } |
3789 | ||
3ba00929 DS |
3790 | /* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */ |
3791 | struct ftrace_glob { | |
3792 | char *search; | |
3793 | unsigned len; | |
3794 | int type; | |
3795 | }; | |
3796 | ||
7132e2d6 TJB |
3797 | /* |
3798 | * If symbols in an architecture don't correspond exactly to the user-visible | |
3799 | * name of what they represent, it is possible to define this function to | |
3800 | * perform the necessary adjustments. | |
3801 | */ | |
3802 | char * __weak arch_ftrace_match_adjust(char *str, const char *search) | |
3803 | { | |
3804 | return str; | |
3805 | } | |
3806 | ||
3ba00929 | 3807 | static int ftrace_match(char *str, struct ftrace_glob *g) |
9f4801e3 | 3808 | { |
9f4801e3 | 3809 | int matched = 0; |
751e9983 | 3810 | int slen; |
9f4801e3 | 3811 | |
7132e2d6 TJB |
3812 | str = arch_ftrace_match_adjust(str, g->search); |
3813 | ||
3ba00929 | 3814 | switch (g->type) { |
9f4801e3 | 3815 | case MATCH_FULL: |
3ba00929 | 3816 | if (strcmp(str, g->search) == 0) |
9f4801e3 SR |
3817 | matched = 1; |
3818 | break; | |
3819 | case MATCH_FRONT_ONLY: | |
3ba00929 | 3820 | if (strncmp(str, g->search, g->len) == 0) |
9f4801e3 SR |
3821 | matched = 1; |
3822 | break; | |
3823 | case MATCH_MIDDLE_ONLY: | |
3ba00929 | 3824 | if (strstr(str, g->search)) |
9f4801e3 SR |
3825 | matched = 1; |
3826 | break; | |
3827 | case MATCH_END_ONLY: | |
751e9983 | 3828 | slen = strlen(str); |
3ba00929 DS |
3829 | if (slen >= g->len && |
3830 | memcmp(str + slen - g->len, g->search, g->len) == 0) | |
9f4801e3 SR |
3831 | matched = 1; |
3832 | break; | |
60f1d5e3 MH |
3833 | case MATCH_GLOB: |
3834 | if (glob_match(g->search, str)) | |
3835 | matched = 1; | |
3836 | break; | |
9f4801e3 SR |
3837 | } |
3838 | ||
3839 | return matched; | |
3840 | } | |
3841 | ||
b448c4e3 | 3842 | static int |
f0a3b154 | 3843 | enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter) |
996e87be | 3844 | { |
b448c4e3 | 3845 | struct ftrace_func_entry *entry; |
b448c4e3 SR |
3846 | int ret = 0; |
3847 | ||
1cf41dd7 | 3848 | entry = ftrace_lookup_ip(hash, rec->ip); |
f0a3b154 | 3849 | if (clear_filter) { |
1cf41dd7 SR |
3850 | /* Do nothing if it doesn't exist */ |
3851 | if (!entry) | |
3852 | return 0; | |
b448c4e3 | 3853 | |
33dc9b12 | 3854 | free_hash_entry(hash, entry); |
1cf41dd7 SR |
3855 | } else { |
3856 | /* Do nothing if it exists */ | |
3857 | if (entry) | |
3858 | return 0; | |
b448c4e3 | 3859 | |
1cf41dd7 | 3860 | ret = add_hash_entry(hash, rec->ip); |
b448c4e3 SR |
3861 | } |
3862 | return ret; | |
996e87be SR |
3863 | } |
3864 | ||
f79b3f33 SRV |
3865 | static int |
3866 | add_rec_by_index(struct ftrace_hash *hash, struct ftrace_glob *func_g, | |
3867 | int clear_filter) | |
3868 | { | |
3869 | long index = simple_strtoul(func_g->search, NULL, 0); | |
3870 | struct ftrace_page *pg; | |
3871 | struct dyn_ftrace *rec; | |
3872 | ||
3873 | /* The index starts at 1 */ | |
3874 | if (--index < 0) | |
3875 | return 0; | |
3876 | ||
3877 | do_for_each_ftrace_rec(pg, rec) { | |
3878 | if (pg->index <= index) { | |
3879 | index -= pg->index; | |
3880 | /* this is a double loop, break goes to the next page */ | |
3881 | break; | |
3882 | } | |
3883 | rec = &pg->records[index]; | |
3884 | enter_record(hash, rec, clear_filter); | |
3885 | return 1; | |
3886 | } while_for_each_ftrace_rec(); | |
3887 | return 0; | |
3888 | } | |
3889 | ||
64e7c440 | 3890 | static int |
0b507e1e DS |
3891 | ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g, |
3892 | struct ftrace_glob *mod_g, int exclude_mod) | |
64e7c440 SR |
3893 | { |
3894 | char str[KSYM_SYMBOL_LEN]; | |
b9df92d2 SR |
3895 | char *modname; |
3896 | ||
3897 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
3898 | ||
0b507e1e DS |
3899 | if (mod_g) { |
3900 | int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0; | |
3901 | ||
3902 | /* blank module name to match all modules */ | |
3903 | if (!mod_g->len) { | |
3904 | /* blank module globbing: modname xor exclude_mod */ | |
77c0edde | 3905 | if (!exclude_mod != !modname) |
0b507e1e DS |
3906 | goto func_match; |
3907 | return 0; | |
3908 | } | |
3909 | ||
77c0edde SRV |
3910 | /* |
3911 | * exclude_mod is set to trace everything but the given | |
3912 | * module. If it is set and the module matches, then | |
3913 | * return 0. If it is not set, and the module doesn't match | |
3914 | * also return 0. Otherwise, check the function to see if | |
3915 | * that matches. | |
3916 | */ | |
3917 | if (!mod_matches == !exclude_mod) | |
b9df92d2 | 3918 | return 0; |
0b507e1e | 3919 | func_match: |
b9df92d2 | 3920 | /* blank search means to match all funcs in the mod */ |
3ba00929 | 3921 | if (!func_g->len) |
b9df92d2 SR |
3922 | return 1; |
3923 | } | |
64e7c440 | 3924 | |
3ba00929 | 3925 | return ftrace_match(str, func_g); |
64e7c440 SR |
3926 | } |
3927 | ||
1cf41dd7 | 3928 | static int |
3ba00929 | 3929 | match_records(struct ftrace_hash *hash, char *func, int len, char *mod) |
9f4801e3 | 3930 | { |
9f4801e3 SR |
3931 | struct ftrace_page *pg; |
3932 | struct dyn_ftrace *rec; | |
3ba00929 | 3933 | struct ftrace_glob func_g = { .type = MATCH_FULL }; |
0b507e1e DS |
3934 | struct ftrace_glob mod_g = { .type = MATCH_FULL }; |
3935 | struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL; | |
3936 | int exclude_mod = 0; | |
311d16da | 3937 | int found = 0; |
b448c4e3 | 3938 | int ret; |
2e028c4f | 3939 | int clear_filter = 0; |
9f4801e3 | 3940 | |
0b507e1e | 3941 | if (func) { |
3ba00929 DS |
3942 | func_g.type = filter_parse_regex(func, len, &func_g.search, |
3943 | &clear_filter); | |
3944 | func_g.len = strlen(func_g.search); | |
b9df92d2 | 3945 | } |
9f4801e3 | 3946 | |
0b507e1e DS |
3947 | if (mod) { |
3948 | mod_g.type = filter_parse_regex(mod, strlen(mod), | |
3949 | &mod_g.search, &exclude_mod); | |
3950 | mod_g.len = strlen(mod_g.search); | |
b9df92d2 | 3951 | } |
9f4801e3 | 3952 | |
52baf119 | 3953 | mutex_lock(&ftrace_lock); |
265c831c | 3954 | |
b9df92d2 SR |
3955 | if (unlikely(ftrace_disabled)) |
3956 | goto out_unlock; | |
9f4801e3 | 3957 | |
f79b3f33 SRV |
3958 | if (func_g.type == MATCH_INDEX) { |
3959 | found = add_rec_by_index(hash, &func_g, clear_filter); | |
3960 | goto out_unlock; | |
3961 | } | |
3962 | ||
265c831c | 3963 | do_for_each_ftrace_rec(pg, rec) { |
546fece4 SRRH |
3964 | |
3965 | if (rec->flags & FTRACE_FL_DISABLED) | |
3966 | continue; | |
3967 | ||
0b507e1e | 3968 | if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) { |
f0a3b154 | 3969 | ret = enter_record(hash, rec, clear_filter); |
b448c4e3 SR |
3970 | if (ret < 0) { |
3971 | found = ret; | |
3972 | goto out_unlock; | |
3973 | } | |
311d16da | 3974 | found = 1; |
265c831c SR |
3975 | } |
3976 | } while_for_each_ftrace_rec(); | |
b9df92d2 | 3977 | out_unlock: |
52baf119 | 3978 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
3979 | |
3980 | return found; | |
5072c59f SR |
3981 | } |
3982 | ||
64e7c440 | 3983 | static int |
1cf41dd7 | 3984 | ftrace_match_records(struct ftrace_hash *hash, char *buff, int len) |
64e7c440 | 3985 | { |
f0a3b154 | 3986 | return match_records(hash, buff, len, NULL); |
64e7c440 SR |
3987 | } |
3988 | ||
e16b35dd SRV |
3989 | static void ftrace_ops_update_code(struct ftrace_ops *ops, |
3990 | struct ftrace_ops_hash *old_hash) | |
3991 | { | |
3992 | struct ftrace_ops *op; | |
3993 | ||
3994 | if (!ftrace_enabled) | |
3995 | return; | |
3996 | ||
3997 | if (ops->flags & FTRACE_OPS_FL_ENABLED) { | |
3998 | ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash); | |
3999 | return; | |
4000 | } | |
4001 | ||
4002 | /* | |
4003 | * If this is the shared global_ops filter, then we need to | |
4004 | * check if there is another ops that shares it, is enabled. | |
4005 | * If so, we still need to run the modify code. | |
4006 | */ | |
4007 | if (ops->func_hash != &global_ops.local_hash) | |
4008 | return; | |
4009 | ||
4010 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
4011 | if (op->func_hash == &global_ops.local_hash && | |
4012 | op->flags & FTRACE_OPS_FL_ENABLED) { | |
4013 | ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash); | |
4014 | /* Only need to do this once */ | |
4015 | return; | |
4016 | } | |
4017 | } while_for_each_ftrace_op(op); | |
4018 | } | |
4019 | ||
4020 | static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops, | |
4021 | struct ftrace_hash **orig_hash, | |
4022 | struct ftrace_hash *hash, | |
4023 | int enable) | |
4024 | { | |
4025 | struct ftrace_ops_hash old_hash_ops; | |
4026 | struct ftrace_hash *old_hash; | |
4027 | int ret; | |
4028 | ||
4029 | old_hash = *orig_hash; | |
4030 | old_hash_ops.filter_hash = ops->func_hash->filter_hash; | |
4031 | old_hash_ops.notrace_hash = ops->func_hash->notrace_hash; | |
4032 | ret = ftrace_hash_move(ops, enable, orig_hash, hash); | |
4033 | if (!ret) { | |
4034 | ftrace_ops_update_code(ops, &old_hash_ops); | |
4035 | free_ftrace_hash_rcu(old_hash); | |
4036 | } | |
4037 | return ret; | |
4038 | } | |
64e7c440 | 4039 | |
673feb9d SRV |
4040 | static bool module_exists(const char *module) |
4041 | { | |
4042 | /* All modules have the symbol __this_module */ | |
0f5e5a3a | 4043 | static const char this_mod[] = "__this_module"; |
419e9fe5 | 4044 | char modname[MAX_PARAM_PREFIX_LEN + sizeof(this_mod) + 2]; |
673feb9d SRV |
4045 | unsigned long val; |
4046 | int n; | |
4047 | ||
419e9fe5 | 4048 | n = snprintf(modname, sizeof(modname), "%s:%s", module, this_mod); |
673feb9d | 4049 | |
419e9fe5 | 4050 | if (n > sizeof(modname) - 1) |
673feb9d SRV |
4051 | return false; |
4052 | ||
4053 | val = module_kallsyms_lookup_name(modname); | |
4054 | return val != 0; | |
4055 | } | |
4056 | ||
4057 | static int cache_mod(struct trace_array *tr, | |
4058 | const char *func, char *module, int enable) | |
4059 | { | |
4060 | struct ftrace_mod_load *ftrace_mod, *n; | |
4061 | struct list_head *head = enable ? &tr->mod_trace : &tr->mod_notrace; | |
4062 | int ret; | |
4063 | ||
4064 | mutex_lock(&ftrace_lock); | |
4065 | ||
4066 | /* We do not cache inverse filters */ | |
4067 | if (func[0] == '!') { | |
4068 | func++; | |
4069 | ret = -EINVAL; | |
4070 | ||
4071 | /* Look to remove this hash */ | |
4072 | list_for_each_entry_safe(ftrace_mod, n, head, list) { | |
4073 | if (strcmp(ftrace_mod->module, module) != 0) | |
4074 | continue; | |
4075 | ||
4076 | /* no func matches all */ | |
44925dff | 4077 | if (strcmp(func, "*") == 0 || |
673feb9d SRV |
4078 | (ftrace_mod->func && |
4079 | strcmp(ftrace_mod->func, func) == 0)) { | |
4080 | ret = 0; | |
4081 | free_ftrace_mod(ftrace_mod); | |
4082 | continue; | |
4083 | } | |
4084 | } | |
4085 | goto out; | |
4086 | } | |
4087 | ||
4088 | ret = -EINVAL; | |
4089 | /* We only care about modules that have not been loaded yet */ | |
4090 | if (module_exists(module)) | |
4091 | goto out; | |
4092 | ||
4093 | /* Save this string off, and execute it when the module is loaded */ | |
4094 | ret = ftrace_add_mod(tr, func, module, enable); | |
4095 | out: | |
4096 | mutex_unlock(&ftrace_lock); | |
4097 | ||
4098 | return ret; | |
4099 | } | |
4100 | ||
d7fbf8df SRV |
4101 | static int |
4102 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, | |
4103 | int reset, int enable); | |
4104 | ||
69449bbd | 4105 | #ifdef CONFIG_MODULES |
d7fbf8df SRV |
4106 | static void process_mod_list(struct list_head *head, struct ftrace_ops *ops, |
4107 | char *mod, bool enable) | |
4108 | { | |
4109 | struct ftrace_mod_load *ftrace_mod, *n; | |
4110 | struct ftrace_hash **orig_hash, *new_hash; | |
4111 | LIST_HEAD(process_mods); | |
4112 | char *func; | |
4113 | int ret; | |
4114 | ||
4115 | mutex_lock(&ops->func_hash->regex_lock); | |
4116 | ||
4117 | if (enable) | |
4118 | orig_hash = &ops->func_hash->filter_hash; | |
4119 | else | |
4120 | orig_hash = &ops->func_hash->notrace_hash; | |
4121 | ||
4122 | new_hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, | |
4123 | *orig_hash); | |
4124 | if (!new_hash) | |
3b58a3c7 | 4125 | goto out; /* warn? */ |
d7fbf8df SRV |
4126 | |
4127 | mutex_lock(&ftrace_lock); | |
4128 | ||
4129 | list_for_each_entry_safe(ftrace_mod, n, head, list) { | |
4130 | ||
4131 | if (strcmp(ftrace_mod->module, mod) != 0) | |
4132 | continue; | |
4133 | ||
4134 | if (ftrace_mod->func) | |
4135 | func = kstrdup(ftrace_mod->func, GFP_KERNEL); | |
4136 | else | |
4137 | func = kstrdup("*", GFP_KERNEL); | |
4138 | ||
4139 | if (!func) /* warn? */ | |
4140 | continue; | |
4141 | ||
4142 | list_del(&ftrace_mod->list); | |
4143 | list_add(&ftrace_mod->list, &process_mods); | |
4144 | ||
4145 | /* Use the newly allocated func, as it may be "*" */ | |
4146 | kfree(ftrace_mod->func); | |
4147 | ftrace_mod->func = func; | |
4148 | } | |
4149 | ||
4150 | mutex_unlock(&ftrace_lock); | |
4151 | ||
4152 | list_for_each_entry_safe(ftrace_mod, n, &process_mods, list) { | |
4153 | ||
4154 | func = ftrace_mod->func; | |
4155 | ||
4156 | /* Grabs ftrace_lock, which is why we have this extra step */ | |
4157 | match_records(new_hash, func, strlen(func), mod); | |
4158 | free_ftrace_mod(ftrace_mod); | |
4159 | } | |
4160 | ||
8c08f0d5 SRV |
4161 | if (enable && list_empty(head)) |
4162 | new_hash->flags &= ~FTRACE_HASH_FL_MOD; | |
4163 | ||
d7fbf8df SRV |
4164 | mutex_lock(&ftrace_lock); |
4165 | ||
4166 | ret = ftrace_hash_move_and_update_ops(ops, orig_hash, | |
4167 | new_hash, enable); | |
4168 | mutex_unlock(&ftrace_lock); | |
4169 | ||
3b58a3c7 | 4170 | out: |
d7fbf8df SRV |
4171 | mutex_unlock(&ops->func_hash->regex_lock); |
4172 | ||
4173 | free_ftrace_hash(new_hash); | |
4174 | } | |
4175 | ||
4176 | static void process_cached_mods(const char *mod_name) | |
4177 | { | |
4178 | struct trace_array *tr; | |
4179 | char *mod; | |
4180 | ||
4181 | mod = kstrdup(mod_name, GFP_KERNEL); | |
4182 | if (!mod) | |
4183 | return; | |
4184 | ||
4185 | mutex_lock(&trace_types_lock); | |
4186 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
4187 | if (!list_empty(&tr->mod_trace)) | |
4188 | process_mod_list(&tr->mod_trace, tr->ops, mod, true); | |
4189 | if (!list_empty(&tr->mod_notrace)) | |
4190 | process_mod_list(&tr->mod_notrace, tr->ops, mod, false); | |
4191 | } | |
4192 | mutex_unlock(&trace_types_lock); | |
4193 | ||
4194 | kfree(mod); | |
4195 | } | |
69449bbd | 4196 | #endif |
d7fbf8df | 4197 | |
f6180773 SR |
4198 | /* |
4199 | * We register the module command as a template to show others how | |
4200 | * to register the a command as well. | |
4201 | */ | |
4202 | ||
4203 | static int | |
04ec7bb6 | 4204 | ftrace_mod_callback(struct trace_array *tr, struct ftrace_hash *hash, |
673feb9d | 4205 | char *func_orig, char *cmd, char *module, int enable) |
f6180773 | 4206 | { |
673feb9d | 4207 | char *func; |
5e3949f0 | 4208 | int ret; |
f6180773 | 4209 | |
673feb9d SRV |
4210 | /* match_records() modifies func, and we need the original */ |
4211 | func = kstrdup(func_orig, GFP_KERNEL); | |
4212 | if (!func) | |
4213 | return -ENOMEM; | |
4214 | ||
f6180773 SR |
4215 | /* |
4216 | * cmd == 'mod' because we only registered this func | |
4217 | * for the 'mod' ftrace_func_command. | |
4218 | * But if you register one func with multiple commands, | |
4219 | * you can tell which command was used by the cmd | |
4220 | * parameter. | |
4221 | */ | |
f0a3b154 | 4222 | ret = match_records(hash, func, strlen(func), module); |
673feb9d SRV |
4223 | kfree(func); |
4224 | ||
b448c4e3 | 4225 | if (!ret) |
673feb9d | 4226 | return cache_mod(tr, func_orig, module, enable); |
b448c4e3 SR |
4227 | if (ret < 0) |
4228 | return ret; | |
b448c4e3 | 4229 | return 0; |
f6180773 SR |
4230 | } |
4231 | ||
4232 | static struct ftrace_func_command ftrace_mod_cmd = { | |
4233 | .name = "mod", | |
4234 | .func = ftrace_mod_callback, | |
4235 | }; | |
4236 | ||
4237 | static int __init ftrace_mod_cmd_init(void) | |
4238 | { | |
4239 | return register_ftrace_command(&ftrace_mod_cmd); | |
4240 | } | |
6f415672 | 4241 | core_initcall(ftrace_mod_cmd_init); |
f6180773 | 4242 | |
2f5f6ad9 | 4243 | static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 4244 | struct ftrace_ops *op, struct pt_regs *pt_regs) |
59df055f | 4245 | { |
eee8ded1 | 4246 | struct ftrace_probe_ops *probe_ops; |
7b60f3d8 | 4247 | struct ftrace_func_probe *probe; |
59df055f | 4248 | |
7b60f3d8 SRV |
4249 | probe = container_of(op, struct ftrace_func_probe, ops); |
4250 | probe_ops = probe->probe_ops; | |
59df055f SR |
4251 | |
4252 | /* | |
4253 | * Disable preemption for these calls to prevent a RCU grace | |
4254 | * period. This syncs the hash iteration and freeing of items | |
4255 | * on the hash. rcu_read_lock is too dangerous here. | |
4256 | */ | |
5168ae50 | 4257 | preempt_disable_notrace(); |
6e444319 | 4258 | probe_ops->func(ip, parent_ip, probe->tr, probe_ops, probe->data); |
5168ae50 | 4259 | preempt_enable_notrace(); |
59df055f SR |
4260 | } |
4261 | ||
41794f19 SRV |
4262 | struct ftrace_func_map { |
4263 | struct ftrace_func_entry entry; | |
4264 | void *data; | |
59df055f SR |
4265 | }; |
4266 | ||
41794f19 SRV |
4267 | struct ftrace_func_mapper { |
4268 | struct ftrace_hash hash; | |
4269 | }; | |
59df055f | 4270 | |
41794f19 SRV |
4271 | /** |
4272 | * allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper | |
4273 | * | |
4274 | * Returns a ftrace_func_mapper descriptor that can be used to map ips to data. | |
4275 | */ | |
4276 | struct ftrace_func_mapper *allocate_ftrace_func_mapper(void) | |
59df055f | 4277 | { |
41794f19 | 4278 | struct ftrace_hash *hash; |
59df055f | 4279 | |
41794f19 SRV |
4280 | /* |
4281 | * The mapper is simply a ftrace_hash, but since the entries | |
4282 | * in the hash are not ftrace_func_entry type, we define it | |
4283 | * as a separate structure. | |
4284 | */ | |
4285 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); | |
4286 | return (struct ftrace_func_mapper *)hash; | |
4287 | } | |
59df055f | 4288 | |
41794f19 SRV |
4289 | /** |
4290 | * ftrace_func_mapper_find_ip - Find some data mapped to an ip | |
4291 | * @mapper: The mapper that has the ip maps | |
4292 | * @ip: the instruction pointer to find the data for | |
4293 | * | |
4294 | * Returns the data mapped to @ip if found otherwise NULL. The return | |
4295 | * is actually the address of the mapper data pointer. The address is | |
4296 | * returned for use cases where the data is no bigger than a long, and | |
4297 | * the user can use the data pointer as its data instead of having to | |
4298 | * allocate more memory for the reference. | |
4299 | */ | |
4300 | void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper, | |
4301 | unsigned long ip) | |
4302 | { | |
4303 | struct ftrace_func_entry *entry; | |
4304 | struct ftrace_func_map *map; | |
59df055f | 4305 | |
41794f19 SRV |
4306 | entry = ftrace_lookup_ip(&mapper->hash, ip); |
4307 | if (!entry) | |
4308 | return NULL; | |
b848914c | 4309 | |
41794f19 SRV |
4310 | map = (struct ftrace_func_map *)entry; |
4311 | return &map->data; | |
59df055f SR |
4312 | } |
4313 | ||
41794f19 SRV |
4314 | /** |
4315 | * ftrace_func_mapper_add_ip - Map some data to an ip | |
4316 | * @mapper: The mapper that has the ip maps | |
4317 | * @ip: The instruction pointer address to map @data to | |
4318 | * @data: The data to map to @ip | |
4319 | * | |
4320 | * Returns 0 on succes otherwise an error. | |
4321 | */ | |
4322 | int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper, | |
4323 | unsigned long ip, void *data) | |
59df055f | 4324 | { |
41794f19 SRV |
4325 | struct ftrace_func_entry *entry; |
4326 | struct ftrace_func_map *map; | |
59df055f | 4327 | |
41794f19 SRV |
4328 | entry = ftrace_lookup_ip(&mapper->hash, ip); |
4329 | if (entry) | |
4330 | return -EBUSY; | |
59df055f | 4331 | |
41794f19 SRV |
4332 | map = kmalloc(sizeof(*map), GFP_KERNEL); |
4333 | if (!map) | |
4334 | return -ENOMEM; | |
59df055f | 4335 | |
41794f19 SRV |
4336 | map->entry.ip = ip; |
4337 | map->data = data; | |
b848914c | 4338 | |
41794f19 | 4339 | __add_hash_entry(&mapper->hash, &map->entry); |
59df055f | 4340 | |
41794f19 SRV |
4341 | return 0; |
4342 | } | |
59df055f | 4343 | |
41794f19 SRV |
4344 | /** |
4345 | * ftrace_func_mapper_remove_ip - Remove an ip from the mapping | |
4346 | * @mapper: The mapper that has the ip maps | |
4347 | * @ip: The instruction pointer address to remove the data from | |
4348 | * | |
4349 | * Returns the data if it is found, otherwise NULL. | |
4350 | * Note, if the data pointer is used as the data itself, (see | |
4351 | * ftrace_func_mapper_find_ip(), then the return value may be meaningless, | |
4352 | * if the data pointer was set to zero. | |
4353 | */ | |
4354 | void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper, | |
4355 | unsigned long ip) | |
59df055f | 4356 | { |
41794f19 SRV |
4357 | struct ftrace_func_entry *entry; |
4358 | struct ftrace_func_map *map; | |
4359 | void *data; | |
4360 | ||
4361 | entry = ftrace_lookup_ip(&mapper->hash, ip); | |
4362 | if (!entry) | |
4363 | return NULL; | |
4364 | ||
4365 | map = (struct ftrace_func_map *)entry; | |
4366 | data = map->data; | |
4367 | ||
4368 | remove_hash_entry(&mapper->hash, entry); | |
59df055f | 4369 | kfree(entry); |
41794f19 SRV |
4370 | |
4371 | return data; | |
4372 | } | |
4373 | ||
4374 | /** | |
4375 | * free_ftrace_func_mapper - free a mapping of ips and data | |
4376 | * @mapper: The mapper that has the ip maps | |
4377 | * @free_func: A function to be called on each data item. | |
4378 | * | |
4379 | * This is used to free the function mapper. The @free_func is optional | |
4380 | * and can be used if the data needs to be freed as well. | |
4381 | */ | |
4382 | void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper, | |
4383 | ftrace_mapper_func free_func) | |
4384 | { | |
4385 | struct ftrace_func_entry *entry; | |
4386 | struct ftrace_func_map *map; | |
4387 | struct hlist_head *hhd; | |
04e03d9a WL |
4388 | int size, i; |
4389 | ||
4390 | if (!mapper) | |
4391 | return; | |
41794f19 SRV |
4392 | |
4393 | if (free_func && mapper->hash.count) { | |
04e03d9a | 4394 | size = 1 << mapper->hash.size_bits; |
41794f19 SRV |
4395 | for (i = 0; i < size; i++) { |
4396 | hhd = &mapper->hash.buckets[i]; | |
4397 | hlist_for_each_entry(entry, hhd, hlist) { | |
4398 | map = (struct ftrace_func_map *)entry; | |
4399 | free_func(map); | |
4400 | } | |
4401 | } | |
4402 | } | |
4403 | free_ftrace_hash(&mapper->hash); | |
4404 | } | |
4405 | ||
7b60f3d8 SRV |
4406 | static void release_probe(struct ftrace_func_probe *probe) |
4407 | { | |
4408 | struct ftrace_probe_ops *probe_ops; | |
4409 | ||
4410 | mutex_lock(&ftrace_lock); | |
4411 | ||
4412 | WARN_ON(probe->ref <= 0); | |
4413 | ||
4414 | /* Subtract the ref that was used to protect this instance */ | |
4415 | probe->ref--; | |
4416 | ||
4417 | if (!probe->ref) { | |
4418 | probe_ops = probe->probe_ops; | |
6e444319 SRV |
4419 | /* |
4420 | * Sending zero as ip tells probe_ops to free | |
4421 | * the probe->data itself | |
4422 | */ | |
4423 | if (probe_ops->free) | |
4424 | probe_ops->free(probe_ops, probe->tr, 0, probe->data); | |
7b60f3d8 SRV |
4425 | list_del(&probe->list); |
4426 | kfree(probe); | |
4427 | } | |
4428 | mutex_unlock(&ftrace_lock); | |
4429 | } | |
4430 | ||
4431 | static void acquire_probe_locked(struct ftrace_func_probe *probe) | |
4432 | { | |
4433 | /* | |
4434 | * Add one ref to keep it from being freed when releasing the | |
4435 | * ftrace_lock mutex. | |
4436 | */ | |
4437 | probe->ref++; | |
59df055f SR |
4438 | } |
4439 | ||
59df055f | 4440 | int |
04ec7bb6 | 4441 | register_ftrace_function_probe(char *glob, struct trace_array *tr, |
7b60f3d8 SRV |
4442 | struct ftrace_probe_ops *probe_ops, |
4443 | void *data) | |
59df055f | 4444 | { |
1ec3a81a | 4445 | struct ftrace_func_entry *entry; |
7b60f3d8 | 4446 | struct ftrace_func_probe *probe; |
1ec3a81a SRV |
4447 | struct ftrace_hash **orig_hash; |
4448 | struct ftrace_hash *old_hash; | |
e1df4cb6 | 4449 | struct ftrace_hash *hash; |
59df055f | 4450 | int count = 0; |
1ec3a81a | 4451 | int size; |
e1df4cb6 | 4452 | int ret; |
1ec3a81a | 4453 | int i; |
59df055f | 4454 | |
04ec7bb6 | 4455 | if (WARN_ON(!tr)) |
59df055f SR |
4456 | return -EINVAL; |
4457 | ||
1ec3a81a SRV |
4458 | /* We do not support '!' for function probes */ |
4459 | if (WARN_ON(glob[0] == '!')) | |
59df055f | 4460 | return -EINVAL; |
59df055f | 4461 | |
7485058e | 4462 | |
7b60f3d8 SRV |
4463 | mutex_lock(&ftrace_lock); |
4464 | /* Check if the probe_ops is already registered */ | |
4465 | list_for_each_entry(probe, &tr->func_probes, list) { | |
4466 | if (probe->probe_ops == probe_ops) | |
4467 | break; | |
e1df4cb6 | 4468 | } |
7b60f3d8 SRV |
4469 | if (&probe->list == &tr->func_probes) { |
4470 | probe = kzalloc(sizeof(*probe), GFP_KERNEL); | |
4471 | if (!probe) { | |
4472 | mutex_unlock(&ftrace_lock); | |
4473 | return -ENOMEM; | |
4474 | } | |
4475 | probe->probe_ops = probe_ops; | |
4476 | probe->ops.func = function_trace_probe_call; | |
4477 | probe->tr = tr; | |
4478 | ftrace_ops_init(&probe->ops); | |
4479 | list_add(&probe->list, &tr->func_probes); | |
e1df4cb6 | 4480 | } |
59df055f | 4481 | |
7b60f3d8 | 4482 | acquire_probe_locked(probe); |
5ae0bf59 | 4483 | |
7b60f3d8 | 4484 | mutex_unlock(&ftrace_lock); |
59df055f | 4485 | |
372e0d01 SRV |
4486 | /* |
4487 | * Note, there's a small window here that the func_hash->filter_hash | |
4488 | * may be NULL or empty. Need to be carefule when reading the loop. | |
4489 | */ | |
7b60f3d8 | 4490 | mutex_lock(&probe->ops.func_hash->regex_lock); |
546fece4 | 4491 | |
7b60f3d8 | 4492 | orig_hash = &probe->ops.func_hash->filter_hash; |
1ec3a81a SRV |
4493 | old_hash = *orig_hash; |
4494 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); | |
59df055f | 4495 | |
5b0022dd NR |
4496 | if (!hash) { |
4497 | ret = -ENOMEM; | |
4498 | goto out; | |
4499 | } | |
4500 | ||
1ec3a81a | 4501 | ret = ftrace_match_records(hash, glob, strlen(glob)); |
59df055f | 4502 | |
1ec3a81a SRV |
4503 | /* Nothing found? */ |
4504 | if (!ret) | |
4505 | ret = -EINVAL; | |
59df055f | 4506 | |
1ec3a81a SRV |
4507 | if (ret < 0) |
4508 | goto out; | |
59df055f | 4509 | |
1ec3a81a SRV |
4510 | size = 1 << hash->size_bits; |
4511 | for (i = 0; i < size; i++) { | |
4512 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
4513 | if (ftrace_lookup_ip(old_hash, entry->ip)) | |
59df055f | 4514 | continue; |
1ec3a81a SRV |
4515 | /* |
4516 | * The caller might want to do something special | |
4517 | * for each function we find. We call the callback | |
4518 | * to give the caller an opportunity to do so. | |
4519 | */ | |
7b60f3d8 SRV |
4520 | if (probe_ops->init) { |
4521 | ret = probe_ops->init(probe_ops, tr, | |
6e444319 SRV |
4522 | entry->ip, data, |
4523 | &probe->data); | |
4524 | if (ret < 0) { | |
4525 | if (probe_ops->free && count) | |
4526 | probe_ops->free(probe_ops, tr, | |
4527 | 0, probe->data); | |
4528 | probe->data = NULL; | |
eee8ded1 | 4529 | goto out; |
6e444319 | 4530 | } |
59df055f | 4531 | } |
1ec3a81a | 4532 | count++; |
59df055f | 4533 | } |
1ec3a81a | 4534 | } |
59df055f | 4535 | |
1ec3a81a | 4536 | mutex_lock(&ftrace_lock); |
59df055f | 4537 | |
7b60f3d8 SRV |
4538 | if (!count) { |
4539 | /* Nothing was added? */ | |
4540 | ret = -EINVAL; | |
4541 | goto out_unlock; | |
4542 | } | |
e1df4cb6 | 4543 | |
7b60f3d8 SRV |
4544 | ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash, |
4545 | hash, 1); | |
1ec3a81a | 4546 | if (ret < 0) |
8d70725e | 4547 | goto err_unlock; |
8252ecf3 | 4548 | |
7b60f3d8 SRV |
4549 | /* One ref for each new function traced */ |
4550 | probe->ref += count; | |
8252ecf3 | 4551 | |
7b60f3d8 SRV |
4552 | if (!(probe->ops.flags & FTRACE_OPS_FL_ENABLED)) |
4553 | ret = ftrace_startup(&probe->ops, 0); | |
e1df4cb6 | 4554 | |
59df055f | 4555 | out_unlock: |
5ae0bf59 | 4556 | mutex_unlock(&ftrace_lock); |
8252ecf3 | 4557 | |
3296fc4e | 4558 | if (!ret) |
1ec3a81a | 4559 | ret = count; |
5ae0bf59 | 4560 | out: |
7b60f3d8 | 4561 | mutex_unlock(&probe->ops.func_hash->regex_lock); |
e1df4cb6 | 4562 | free_ftrace_hash(hash); |
59df055f | 4563 | |
7b60f3d8 | 4564 | release_probe(probe); |
59df055f | 4565 | |
1ec3a81a | 4566 | return ret; |
59df055f | 4567 | |
8d70725e | 4568 | err_unlock: |
7b60f3d8 | 4569 | if (!probe_ops->free || !count) |
8d70725e SRV |
4570 | goto out_unlock; |
4571 | ||
4572 | /* Failed to do the move, need to call the free functions */ | |
4573 | for (i = 0; i < size; i++) { | |
4574 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
4575 | if (ftrace_lookup_ip(old_hash, entry->ip)) | |
4576 | continue; | |
6e444319 | 4577 | probe_ops->free(probe_ops, tr, entry->ip, probe->data); |
8d70725e SRV |
4578 | } |
4579 | } | |
4580 | goto out_unlock; | |
59df055f SR |
4581 | } |
4582 | ||
d3d532d7 | 4583 | int |
7b60f3d8 SRV |
4584 | unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr, |
4585 | struct ftrace_probe_ops *probe_ops) | |
59df055f | 4586 | { |
82cc4fc2 | 4587 | struct ftrace_ops_hash old_hash_ops; |
eee8ded1 | 4588 | struct ftrace_func_entry *entry; |
7b60f3d8 | 4589 | struct ftrace_func_probe *probe; |
3ba00929 | 4590 | struct ftrace_glob func_g; |
1ec3a81a SRV |
4591 | struct ftrace_hash **orig_hash; |
4592 | struct ftrace_hash *old_hash; | |
1ec3a81a | 4593 | struct ftrace_hash *hash = NULL; |
b67bfe0d | 4594 | struct hlist_node *tmp; |
eee8ded1 | 4595 | struct hlist_head hhd; |
59df055f | 4596 | char str[KSYM_SYMBOL_LEN]; |
7b60f3d8 SRV |
4597 | int count = 0; |
4598 | int i, ret = -ENODEV; | |
eee8ded1 | 4599 | int size; |
59df055f | 4600 | |
cbab567c | 4601 | if (!glob || !strlen(glob) || !strcmp(glob, "*")) |
3ba00929 | 4602 | func_g.search = NULL; |
cbab567c | 4603 | else { |
59df055f SR |
4604 | int not; |
4605 | ||
3ba00929 DS |
4606 | func_g.type = filter_parse_regex(glob, strlen(glob), |
4607 | &func_g.search, ¬); | |
4608 | func_g.len = strlen(func_g.search); | |
59df055f | 4609 | |
b6887d79 | 4610 | /* we do not support '!' for function probes */ |
59df055f | 4611 | if (WARN_ON(not)) |
d3d532d7 | 4612 | return -EINVAL; |
59df055f SR |
4613 | } |
4614 | ||
7b60f3d8 SRV |
4615 | mutex_lock(&ftrace_lock); |
4616 | /* Check if the probe_ops is already registered */ | |
4617 | list_for_each_entry(probe, &tr->func_probes, list) { | |
4618 | if (probe->probe_ops == probe_ops) | |
4619 | break; | |
59df055f | 4620 | } |
7b60f3d8 SRV |
4621 | if (&probe->list == &tr->func_probes) |
4622 | goto err_unlock_ftrace; | |
4623 | ||
4624 | ret = -EINVAL; | |
4625 | if (!(probe->ops.flags & FTRACE_OPS_FL_INITIALIZED)) | |
4626 | goto err_unlock_ftrace; | |
4627 | ||
4628 | acquire_probe_locked(probe); | |
4629 | ||
4630 | mutex_unlock(&ftrace_lock); | |
59df055f | 4631 | |
7b60f3d8 | 4632 | mutex_lock(&probe->ops.func_hash->regex_lock); |
1ec3a81a | 4633 | |
7b60f3d8 | 4634 | orig_hash = &probe->ops.func_hash->filter_hash; |
1ec3a81a SRV |
4635 | old_hash = *orig_hash; |
4636 | ||
1ec3a81a SRV |
4637 | if (ftrace_hash_empty(old_hash)) |
4638 | goto out_unlock; | |
e1df4cb6 | 4639 | |
82cc4fc2 SRV |
4640 | old_hash_ops.filter_hash = old_hash; |
4641 | /* Probes only have filters */ | |
4642 | old_hash_ops.notrace_hash = NULL; | |
4643 | ||
d3d532d7 | 4644 | ret = -ENOMEM; |
1ec3a81a | 4645 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); |
e1df4cb6 | 4646 | if (!hash) |
e1df4cb6 SRRH |
4647 | goto out_unlock; |
4648 | ||
eee8ded1 | 4649 | INIT_HLIST_HEAD(&hhd); |
59df055f | 4650 | |
eee8ded1 SRV |
4651 | size = 1 << hash->size_bits; |
4652 | for (i = 0; i < size; i++) { | |
4653 | hlist_for_each_entry_safe(entry, tmp, &hash->buckets[i], hlist) { | |
59df055f | 4654 | |
3ba00929 | 4655 | if (func_g.search) { |
59df055f SR |
4656 | kallsyms_lookup(entry->ip, NULL, NULL, |
4657 | NULL, str); | |
3ba00929 | 4658 | if (!ftrace_match(str, &func_g)) |
59df055f SR |
4659 | continue; |
4660 | } | |
7b60f3d8 | 4661 | count++; |
eee8ded1 SRV |
4662 | remove_hash_entry(hash, entry); |
4663 | hlist_add_head(&entry->hlist, &hhd); | |
59df055f SR |
4664 | } |
4665 | } | |
d3d532d7 SRV |
4666 | |
4667 | /* Nothing found? */ | |
7b60f3d8 | 4668 | if (!count) { |
d3d532d7 SRV |
4669 | ret = -EINVAL; |
4670 | goto out_unlock; | |
4671 | } | |
4672 | ||
3f2367ba | 4673 | mutex_lock(&ftrace_lock); |
1ec3a81a | 4674 | |
7b60f3d8 | 4675 | WARN_ON(probe->ref < count); |
eee8ded1 | 4676 | |
7b60f3d8 | 4677 | probe->ref -= count; |
1ec3a81a | 4678 | |
7b60f3d8 SRV |
4679 | if (ftrace_hash_empty(hash)) |
4680 | ftrace_shutdown(&probe->ops, 0); | |
4681 | ||
4682 | ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash, | |
1ec3a81a | 4683 | hash, 1); |
82cc4fc2 SRV |
4684 | |
4685 | /* still need to update the function call sites */ | |
1ec3a81a | 4686 | if (ftrace_enabled && !ftrace_hash_empty(hash)) |
7b60f3d8 | 4687 | ftrace_run_modify_code(&probe->ops, FTRACE_UPDATE_CALLS, |
82cc4fc2 | 4688 | &old_hash_ops); |
74401729 | 4689 | synchronize_rcu(); |
3296fc4e | 4690 | |
eee8ded1 SRV |
4691 | hlist_for_each_entry_safe(entry, tmp, &hhd, hlist) { |
4692 | hlist_del(&entry->hlist); | |
7b60f3d8 | 4693 | if (probe_ops->free) |
6e444319 | 4694 | probe_ops->free(probe_ops, tr, entry->ip, probe->data); |
eee8ded1 | 4695 | kfree(entry); |
7818b388 | 4696 | } |
3f2367ba | 4697 | mutex_unlock(&ftrace_lock); |
3ba00929 | 4698 | |
e1df4cb6 | 4699 | out_unlock: |
7b60f3d8 | 4700 | mutex_unlock(&probe->ops.func_hash->regex_lock); |
e1df4cb6 | 4701 | free_ftrace_hash(hash); |
59df055f | 4702 | |
7b60f3d8 | 4703 | release_probe(probe); |
59df055f | 4704 | |
7b60f3d8 | 4705 | return ret; |
59df055f | 4706 | |
7b60f3d8 SRV |
4707 | err_unlock_ftrace: |
4708 | mutex_unlock(&ftrace_lock); | |
d3d532d7 | 4709 | return ret; |
59df055f SR |
4710 | } |
4711 | ||
a0e6369e NR |
4712 | void clear_ftrace_function_probes(struct trace_array *tr) |
4713 | { | |
4714 | struct ftrace_func_probe *probe, *n; | |
4715 | ||
4716 | list_for_each_entry_safe(probe, n, &tr->func_probes, list) | |
4717 | unregister_ftrace_function_probe_func(NULL, tr, probe->probe_ops); | |
4718 | } | |
4719 | ||
f6180773 SR |
4720 | static LIST_HEAD(ftrace_commands); |
4721 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
4722 | ||
38de93ab TZ |
4723 | /* |
4724 | * Currently we only register ftrace commands from __init, so mark this | |
4725 | * __init too. | |
4726 | */ | |
4727 | __init int register_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
4728 | { |
4729 | struct ftrace_func_command *p; | |
4730 | int ret = 0; | |
4731 | ||
4732 | mutex_lock(&ftrace_cmd_mutex); | |
4733 | list_for_each_entry(p, &ftrace_commands, list) { | |
4734 | if (strcmp(cmd->name, p->name) == 0) { | |
4735 | ret = -EBUSY; | |
4736 | goto out_unlock; | |
4737 | } | |
4738 | } | |
4739 | list_add(&cmd->list, &ftrace_commands); | |
4740 | out_unlock: | |
4741 | mutex_unlock(&ftrace_cmd_mutex); | |
4742 | ||
4743 | return ret; | |
4744 | } | |
4745 | ||
38de93ab TZ |
4746 | /* |
4747 | * Currently we only unregister ftrace commands from __init, so mark | |
4748 | * this __init too. | |
4749 | */ | |
4750 | __init int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
4751 | { |
4752 | struct ftrace_func_command *p, *n; | |
4753 | int ret = -ENODEV; | |
4754 | ||
4755 | mutex_lock(&ftrace_cmd_mutex); | |
4756 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
4757 | if (strcmp(cmd->name, p->name) == 0) { | |
4758 | ret = 0; | |
4759 | list_del_init(&p->list); | |
4760 | goto out_unlock; | |
4761 | } | |
4762 | } | |
4763 | out_unlock: | |
4764 | mutex_unlock(&ftrace_cmd_mutex); | |
4765 | ||
4766 | return ret; | |
4767 | } | |
4768 | ||
04ec7bb6 | 4769 | static int ftrace_process_regex(struct ftrace_iterator *iter, |
33dc9b12 | 4770 | char *buff, int len, int enable) |
64e7c440 | 4771 | { |
04ec7bb6 | 4772 | struct ftrace_hash *hash = iter->hash; |
d2afd57a | 4773 | struct trace_array *tr = iter->ops->private; |
f6180773 | 4774 | char *func, *command, *next = buff; |
6a24a244 | 4775 | struct ftrace_func_command *p; |
0aff1c0c | 4776 | int ret = -EINVAL; |
64e7c440 SR |
4777 | |
4778 | func = strsep(&next, ":"); | |
4779 | ||
4780 | if (!next) { | |
1cf41dd7 | 4781 | ret = ftrace_match_records(hash, func, len); |
b448c4e3 SR |
4782 | if (!ret) |
4783 | ret = -EINVAL; | |
4784 | if (ret < 0) | |
4785 | return ret; | |
4786 | return 0; | |
64e7c440 SR |
4787 | } |
4788 | ||
f6180773 | 4789 | /* command found */ |
64e7c440 SR |
4790 | |
4791 | command = strsep(&next, ":"); | |
4792 | ||
f6180773 SR |
4793 | mutex_lock(&ftrace_cmd_mutex); |
4794 | list_for_each_entry(p, &ftrace_commands, list) { | |
4795 | if (strcmp(p->name, command) == 0) { | |
04ec7bb6 | 4796 | ret = p->func(tr, hash, func, command, next, enable); |
f6180773 SR |
4797 | goto out_unlock; |
4798 | } | |
64e7c440 | 4799 | } |
f6180773 SR |
4800 | out_unlock: |
4801 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 4802 | |
f6180773 | 4803 | return ret; |
64e7c440 SR |
4804 | } |
4805 | ||
e309b41d | 4806 | static ssize_t |
41c52c0d SR |
4807 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
4808 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
4809 | { |
4810 | struct ftrace_iterator *iter; | |
689fd8b6 | 4811 | struct trace_parser *parser; |
4812 | ssize_t ret, read; | |
5072c59f | 4813 | |
4ba7978e | 4814 | if (!cnt) |
5072c59f SR |
4815 | return 0; |
4816 | ||
5072c59f SR |
4817 | if (file->f_mode & FMODE_READ) { |
4818 | struct seq_file *m = file->private_data; | |
4819 | iter = m->private; | |
4820 | } else | |
4821 | iter = file->private_data; | |
4822 | ||
f04f24fb | 4823 | if (unlikely(ftrace_disabled)) |
3f2367ba MH |
4824 | return -ENODEV; |
4825 | ||
4826 | /* iter->hash is a local copy, so we don't need regex_lock */ | |
f04f24fb | 4827 | |
689fd8b6 | 4828 | parser = &iter->parser; |
4829 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 4830 | |
4ba7978e | 4831 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 4832 | !trace_parser_cont(parser)) { |
04ec7bb6 | 4833 | ret = ftrace_process_regex(iter, parser->buffer, |
689fd8b6 | 4834 | parser->idx, enable); |
313254a9 | 4835 | trace_parser_clear(parser); |
7c088b51 | 4836 | if (ret < 0) |
3f2367ba | 4837 | goto out; |
eda1e328 | 4838 | } |
5072c59f | 4839 | |
5072c59f | 4840 | ret = read; |
3f2367ba | 4841 | out: |
5072c59f SR |
4842 | return ret; |
4843 | } | |
4844 | ||
fc13cb0c | 4845 | ssize_t |
41c52c0d SR |
4846 | ftrace_filter_write(struct file *file, const char __user *ubuf, |
4847 | size_t cnt, loff_t *ppos) | |
4848 | { | |
4849 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
4850 | } | |
4851 | ||
fc13cb0c | 4852 | ssize_t |
41c52c0d SR |
4853 | ftrace_notrace_write(struct file *file, const char __user *ubuf, |
4854 | size_t cnt, loff_t *ppos) | |
4855 | { | |
4856 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
4857 | } | |
4858 | ||
33dc9b12 | 4859 | static int |
647664ea MH |
4860 | ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) |
4861 | { | |
4862 | struct ftrace_func_entry *entry; | |
4863 | ||
4864 | if (!ftrace_location(ip)) | |
4865 | return -EINVAL; | |
4866 | ||
4867 | if (remove) { | |
4868 | entry = ftrace_lookup_ip(hash, ip); | |
4869 | if (!entry) | |
4870 | return -ENOENT; | |
4871 | free_hash_entry(hash, entry); | |
4872 | return 0; | |
4873 | } | |
4874 | ||
4875 | return add_hash_entry(hash, ip); | |
4876 | } | |
4877 | ||
4878 | static int | |
4879 | ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, | |
4880 | unsigned long ip, int remove, int reset, int enable) | |
41c52c0d | 4881 | { |
33dc9b12 | 4882 | struct ftrace_hash **orig_hash; |
f45948e8 | 4883 | struct ftrace_hash *hash; |
33dc9b12 | 4884 | int ret; |
f45948e8 | 4885 | |
41c52c0d | 4886 | if (unlikely(ftrace_disabled)) |
33dc9b12 | 4887 | return -ENODEV; |
41c52c0d | 4888 | |
33b7f99c | 4889 | mutex_lock(&ops->func_hash->regex_lock); |
3f2367ba | 4890 | |
f45948e8 | 4891 | if (enable) |
33b7f99c | 4892 | orig_hash = &ops->func_hash->filter_hash; |
f45948e8 | 4893 | else |
33b7f99c | 4894 | orig_hash = &ops->func_hash->notrace_hash; |
33dc9b12 | 4895 | |
b972cc58 WN |
4896 | if (reset) |
4897 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); | |
4898 | else | |
4899 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
4900 | ||
3f2367ba MH |
4901 | if (!hash) { |
4902 | ret = -ENOMEM; | |
4903 | goto out_regex_unlock; | |
4904 | } | |
f45948e8 | 4905 | |
ac483c44 JO |
4906 | if (buf && !ftrace_match_records(hash, buf, len)) { |
4907 | ret = -EINVAL; | |
4908 | goto out_regex_unlock; | |
4909 | } | |
647664ea MH |
4910 | if (ip) { |
4911 | ret = ftrace_match_addr(hash, ip, remove); | |
4912 | if (ret < 0) | |
4913 | goto out_regex_unlock; | |
4914 | } | |
33dc9b12 SR |
4915 | |
4916 | mutex_lock(&ftrace_lock); | |
e16b35dd | 4917 | ret = ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable); |
33dc9b12 SR |
4918 | mutex_unlock(&ftrace_lock); |
4919 | ||
ac483c44 | 4920 | out_regex_unlock: |
33b7f99c | 4921 | mutex_unlock(&ops->func_hash->regex_lock); |
33dc9b12 SR |
4922 | |
4923 | free_ftrace_hash(hash); | |
4924 | return ret; | |
41c52c0d SR |
4925 | } |
4926 | ||
647664ea MH |
4927 | static int |
4928 | ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove, | |
4929 | int reset, int enable) | |
4930 | { | |
9efb85c5 | 4931 | return ftrace_set_hash(ops, NULL, 0, ip, remove, reset, enable); |
647664ea MH |
4932 | } |
4933 | ||
763e34e7 | 4934 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS |
013bf0da SRV |
4935 | |
4936 | struct ftrace_direct_func { | |
4937 | struct list_head next; | |
4938 | unsigned long addr; | |
4939 | int count; | |
4940 | }; | |
4941 | ||
4942 | static LIST_HEAD(ftrace_direct_funcs); | |
4943 | ||
4944 | /** | |
4945 | * ftrace_find_direct_func - test an address if it is a registered direct caller | |
4946 | * @addr: The address of a registered direct caller | |
4947 | * | |
4948 | * This searches to see if a ftrace direct caller has been registered | |
4949 | * at a specific address, and if so, it returns a descriptor for it. | |
4950 | * | |
4951 | * This can be used by architecture code to see if an address is | |
4952 | * a direct caller (trampoline) attached to a fentry/mcount location. | |
4953 | * This is useful for the function_graph tracer, as it may need to | |
4954 | * do adjustments if it traced a location that also has a direct | |
4955 | * trampoline attached to it. | |
4956 | */ | |
4957 | struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr) | |
4958 | { | |
4959 | struct ftrace_direct_func *entry; | |
4960 | bool found = false; | |
4961 | ||
4962 | /* May be called by fgraph trampoline (protected by rcu tasks) */ | |
4963 | list_for_each_entry_rcu(entry, &ftrace_direct_funcs, next) { | |
4964 | if (entry->addr == addr) { | |
4965 | found = true; | |
4966 | break; | |
4967 | } | |
4968 | } | |
4969 | if (found) | |
4970 | return entry; | |
4971 | ||
4972 | return NULL; | |
4973 | } | |
4974 | ||
763e34e7 SRV |
4975 | /** |
4976 | * register_ftrace_direct - Call a custom trampoline directly | |
4977 | * @ip: The address of the nop at the beginning of a function | |
4978 | * @addr: The address of the trampoline to call at @ip | |
4979 | * | |
4980 | * This is used to connect a direct call from the nop location (@ip) | |
4981 | * at the start of ftrace traced functions. The location that it calls | |
4982 | * (@addr) must be able to handle a direct call, and save the parameters | |
4983 | * of the function being traced, and restore them (or inject new ones | |
4984 | * if needed), before returning. | |
4985 | * | |
4986 | * Returns: | |
4987 | * 0 on success | |
4988 | * -EBUSY - Another direct function is already attached (there can be only one) | |
4989 | * -ENODEV - @ip does not point to a ftrace nop location (or not supported) | |
4990 | * -ENOMEM - There was an allocation failure. | |
4991 | */ | |
4992 | int register_ftrace_direct(unsigned long ip, unsigned long addr) | |
4993 | { | |
013bf0da | 4994 | struct ftrace_direct_func *direct; |
763e34e7 SRV |
4995 | struct ftrace_func_entry *entry; |
4996 | struct ftrace_hash *free_hash = NULL; | |
4997 | struct dyn_ftrace *rec; | |
4998 | int ret = -EBUSY; | |
4999 | ||
5000 | mutex_lock(&direct_mutex); | |
5001 | ||
5002 | /* See if there's a direct function at @ip already */ | |
ff205766 | 5003 | if (ftrace_find_rec_direct(ip)) |
763e34e7 SRV |
5004 | goto out_unlock; |
5005 | ||
5006 | ret = -ENODEV; | |
5007 | rec = lookup_rec(ip, ip); | |
5008 | if (!rec) | |
5009 | goto out_unlock; | |
5010 | ||
5011 | /* | |
5012 | * Check if the rec says it has a direct call but we didn't | |
5013 | * find one earlier? | |
5014 | */ | |
5015 | if (WARN_ON(rec->flags & FTRACE_FL_DIRECT)) | |
5016 | goto out_unlock; | |
5017 | ||
5018 | /* Make sure the ip points to the exact record */ | |
406acdd3 SRV |
5019 | if (ip != rec->ip) { |
5020 | ip = rec->ip; | |
5021 | /* Need to check this ip for a direct. */ | |
ff205766 | 5022 | if (ftrace_find_rec_direct(ip)) |
406acdd3 SRV |
5023 | goto out_unlock; |
5024 | } | |
763e34e7 SRV |
5025 | |
5026 | ret = -ENOMEM; | |
5027 | if (ftrace_hash_empty(direct_functions) || | |
5028 | direct_functions->count > 2 * (1 << direct_functions->size_bits)) { | |
5029 | struct ftrace_hash *new_hash; | |
5030 | int size = ftrace_hash_empty(direct_functions) ? 0 : | |
5031 | direct_functions->count + 1; | |
5032 | ||
5033 | if (size < 32) | |
5034 | size = 32; | |
5035 | ||
5036 | new_hash = dup_hash(direct_functions, size); | |
5037 | if (!new_hash) | |
5038 | goto out_unlock; | |
5039 | ||
5040 | free_hash = direct_functions; | |
5041 | direct_functions = new_hash; | |
5042 | } | |
5043 | ||
5044 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
5045 | if (!entry) | |
5046 | goto out_unlock; | |
5047 | ||
013bf0da SRV |
5048 | direct = ftrace_find_direct_func(addr); |
5049 | if (!direct) { | |
5050 | direct = kmalloc(sizeof(*direct), GFP_KERNEL); | |
5051 | if (!direct) { | |
5052 | kfree(entry); | |
5053 | goto out_unlock; | |
5054 | } | |
5055 | direct->addr = addr; | |
5056 | direct->count = 0; | |
5057 | list_add_rcu(&direct->next, &ftrace_direct_funcs); | |
a3ad1a7e | 5058 | ftrace_direct_func_count++; |
013bf0da SRV |
5059 | } |
5060 | ||
763e34e7 SRV |
5061 | entry->ip = ip; |
5062 | entry->direct = addr; | |
5063 | __add_hash_entry(direct_functions, entry); | |
5064 | ||
5065 | ret = ftrace_set_filter_ip(&direct_ops, ip, 0, 0); | |
5066 | if (ret) | |
5067 | remove_hash_entry(direct_functions, entry); | |
5068 | ||
5069 | if (!ret && !(direct_ops.flags & FTRACE_OPS_FL_ENABLED)) { | |
5070 | ret = register_ftrace_function(&direct_ops); | |
5071 | if (ret) | |
5072 | ftrace_set_filter_ip(&direct_ops, ip, 1, 0); | |
5073 | } | |
5074 | ||
013bf0da | 5075 | if (ret) { |
763e34e7 | 5076 | kfree(entry); |
013bf0da SRV |
5077 | if (!direct->count) { |
5078 | list_del_rcu(&direct->next); | |
5079 | synchronize_rcu_tasks(); | |
5080 | kfree(direct); | |
5081 | if (free_hash) | |
5082 | free_ftrace_hash(free_hash); | |
5083 | free_hash = NULL; | |
a3ad1a7e | 5084 | ftrace_direct_func_count--; |
013bf0da SRV |
5085 | } |
5086 | } else { | |
1c7f9b67 | 5087 | direct->count++; |
013bf0da | 5088 | } |
763e34e7 SRV |
5089 | out_unlock: |
5090 | mutex_unlock(&direct_mutex); | |
5091 | ||
5092 | if (free_hash) { | |
5093 | synchronize_rcu_tasks(); | |
5094 | free_ftrace_hash(free_hash); | |
5095 | } | |
5096 | ||
5097 | return ret; | |
5098 | } | |
5099 | EXPORT_SYMBOL_GPL(register_ftrace_direct); | |
5100 | ||
ea806eb3 SRV |
5101 | static struct ftrace_func_entry *find_direct_entry(unsigned long *ip, |
5102 | struct dyn_ftrace **recp) | |
763e34e7 SRV |
5103 | { |
5104 | struct ftrace_func_entry *entry; | |
5105 | struct dyn_ftrace *rec; | |
763e34e7 | 5106 | |
128161f4 SRV |
5107 | rec = lookup_rec(*ip, *ip); |
5108 | if (!rec) | |
5109 | return NULL; | |
763e34e7 | 5110 | |
128161f4 | 5111 | entry = __ftrace_lookup_ip(direct_functions, rec->ip); |
763e34e7 | 5112 | if (!entry) { |
128161f4 SRV |
5113 | WARN_ON(rec->flags & FTRACE_FL_DIRECT); |
5114 | return NULL; | |
5115 | } | |
763e34e7 | 5116 | |
128161f4 | 5117 | WARN_ON(!(rec->flags & FTRACE_FL_DIRECT)); |
763e34e7 | 5118 | |
128161f4 SRV |
5119 | /* Passed in ip just needs to be on the call site */ |
5120 | *ip = rec->ip; | |
5121 | ||
ea806eb3 SRV |
5122 | if (recp) |
5123 | *recp = rec; | |
5124 | ||
128161f4 SRV |
5125 | return entry; |
5126 | } | |
5127 | ||
5128 | int unregister_ftrace_direct(unsigned long ip, unsigned long addr) | |
5129 | { | |
5130 | struct ftrace_direct_func *direct; | |
5131 | struct ftrace_func_entry *entry; | |
5132 | int ret = -ENODEV; | |
5133 | ||
5134 | mutex_lock(&direct_mutex); | |
5135 | ||
ea806eb3 | 5136 | entry = find_direct_entry(&ip, NULL); |
128161f4 SRV |
5137 | if (!entry) |
5138 | goto out_unlock; | |
763e34e7 SRV |
5139 | |
5140 | if (direct_functions->count == 1) | |
5141 | unregister_ftrace_function(&direct_ops); | |
5142 | ||
5143 | ret = ftrace_set_filter_ip(&direct_ops, ip, 1, 0); | |
5144 | ||
5145 | WARN_ON(ret); | |
5146 | ||
5147 | remove_hash_entry(direct_functions, entry); | |
5148 | ||
013bf0da SRV |
5149 | direct = ftrace_find_direct_func(addr); |
5150 | if (!WARN_ON(!direct)) { | |
5151 | /* This is the good path (see the ! before WARN) */ | |
5152 | direct->count--; | |
5153 | WARN_ON(direct->count < 0); | |
5154 | if (!direct->count) { | |
5155 | list_del_rcu(&direct->next); | |
5156 | synchronize_rcu_tasks(); | |
5157 | kfree(direct); | |
a3ad1a7e | 5158 | ftrace_direct_func_count--; |
013bf0da SRV |
5159 | } |
5160 | } | |
763e34e7 SRV |
5161 | out_unlock: |
5162 | mutex_unlock(&direct_mutex); | |
5163 | ||
5164 | return ret; | |
5165 | } | |
5166 | EXPORT_SYMBOL_GPL(unregister_ftrace_direct); | |
0567d680 SRV |
5167 | |
5168 | static struct ftrace_ops stub_ops = { | |
5169 | .func = ftrace_stub, | |
5170 | }; | |
5171 | ||
ea806eb3 SRV |
5172 | /** |
5173 | * ftrace_modify_direct_caller - modify ftrace nop directly | |
5174 | * @entry: The ftrace hash entry of the direct helper for @rec | |
5175 | * @rec: The record representing the function site to patch | |
5176 | * @old_addr: The location that the site at @rec->ip currently calls | |
5177 | * @new_addr: The location that the site at @rec->ip should call | |
5178 | * | |
5179 | * An architecture may overwrite this function to optimize the | |
5180 | * changing of the direct callback on an ftrace nop location. | |
5181 | * This is called with the ftrace_lock mutex held, and no other | |
5182 | * ftrace callbacks are on the associated record (@rec). Thus, | |
5183 | * it is safe to modify the ftrace record, where it should be | |
5184 | * currently calling @old_addr directly, to call @new_addr. | |
5185 | * | |
5186 | * Safety checks should be made to make sure that the code at | |
5187 | * @rec->ip is currently calling @old_addr. And this must | |
5188 | * also update entry->direct to @new_addr. | |
5189 | */ | |
5190 | int __weak ftrace_modify_direct_caller(struct ftrace_func_entry *entry, | |
5191 | struct dyn_ftrace *rec, | |
5192 | unsigned long old_addr, | |
5193 | unsigned long new_addr) | |
5194 | { | |
5195 | unsigned long ip = rec->ip; | |
5196 | int ret; | |
5197 | ||
5198 | /* | |
5199 | * The ftrace_lock was used to determine if the record | |
5200 | * had more than one registered user to it. If it did, | |
5201 | * we needed to prevent that from changing to do the quick | |
5202 | * switch. But if it did not (only a direct caller was attached) | |
5203 | * then this function is called. But this function can deal | |
5204 | * with attached callers to the rec that we care about, and | |
5205 | * since this function uses standard ftrace calls that take | |
5206 | * the ftrace_lock mutex, we need to release it. | |
5207 | */ | |
5208 | mutex_unlock(&ftrace_lock); | |
5209 | ||
5210 | /* | |
5211 | * By setting a stub function at the same address, we force | |
5212 | * the code to call the iterator and the direct_ops helper. | |
5213 | * This means that @ip does not call the direct call, and | |
5214 | * we can simply modify it. | |
5215 | */ | |
5216 | ret = ftrace_set_filter_ip(&stub_ops, ip, 0, 0); | |
5217 | if (ret) | |
5218 | goto out_lock; | |
5219 | ||
5220 | ret = register_ftrace_function(&stub_ops); | |
5221 | if (ret) { | |
5222 | ftrace_set_filter_ip(&stub_ops, ip, 1, 0); | |
5223 | goto out_lock; | |
5224 | } | |
5225 | ||
5226 | entry->direct = new_addr; | |
5227 | ||
5228 | /* | |
5229 | * By removing the stub, we put back the direct call, calling | |
5230 | * the @new_addr. | |
5231 | */ | |
5232 | unregister_ftrace_function(&stub_ops); | |
5233 | ftrace_set_filter_ip(&stub_ops, ip, 1, 0); | |
5234 | ||
5235 | out_lock: | |
5236 | mutex_lock(&ftrace_lock); | |
5237 | ||
5238 | return ret; | |
5239 | } | |
5240 | ||
0567d680 SRV |
5241 | /** |
5242 | * modify_ftrace_direct - Modify an existing direct call to call something else | |
5243 | * @ip: The instruction pointer to modify | |
5244 | * @old_addr: The address that the current @ip calls directly | |
5245 | * @new_addr: The address that the @ip should call | |
5246 | * | |
5247 | * This modifies a ftrace direct caller at an instruction pointer without | |
5248 | * having to disable it first. The direct call will switch over to the | |
5249 | * @new_addr without missing anything. | |
5250 | * | |
5251 | * Returns: zero on success. Non zero on error, which includes: | |
5252 | * -ENODEV : the @ip given has no direct caller attached | |
5253 | * -EINVAL : the @old_addr does not match the current direct caller | |
5254 | */ | |
5255 | int modify_ftrace_direct(unsigned long ip, | |
5256 | unsigned long old_addr, unsigned long new_addr) | |
5257 | { | |
5258 | struct ftrace_func_entry *entry; | |
ea806eb3 | 5259 | struct dyn_ftrace *rec; |
0567d680 SRV |
5260 | int ret = -ENODEV; |
5261 | ||
5262 | mutex_lock(&direct_mutex); | |
0567d680 | 5263 | |
ea806eb3 SRV |
5264 | mutex_lock(&ftrace_lock); |
5265 | entry = find_direct_entry(&ip, &rec); | |
128161f4 SRV |
5266 | if (!entry) |
5267 | goto out_unlock; | |
0567d680 SRV |
5268 | |
5269 | ret = -EINVAL; | |
5270 | if (entry->direct != old_addr) | |
5271 | goto out_unlock; | |
5272 | ||
5273 | /* | |
ea806eb3 SRV |
5274 | * If there's no other ftrace callback on the rec->ip location, |
5275 | * then it can be changed directly by the architecture. | |
5276 | * If there is another caller, then we just need to change the | |
5277 | * direct caller helper to point to @new_addr. | |
0567d680 | 5278 | */ |
ea806eb3 SRV |
5279 | if (ftrace_rec_count(rec) == 1) { |
5280 | ret = ftrace_modify_direct_caller(entry, rec, old_addr, new_addr); | |
5281 | } else { | |
5282 | entry->direct = new_addr; | |
5283 | ret = 0; | |
0567d680 SRV |
5284 | } |
5285 | ||
0567d680 | 5286 | out_unlock: |
ea806eb3 | 5287 | mutex_unlock(&ftrace_lock); |
0567d680 SRV |
5288 | mutex_unlock(&direct_mutex); |
5289 | return ret; | |
5290 | } | |
5291 | EXPORT_SYMBOL_GPL(modify_ftrace_direct); | |
763e34e7 SRV |
5292 | #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */ |
5293 | ||
647664ea MH |
5294 | /** |
5295 | * ftrace_set_filter_ip - set a function to filter on in ftrace by address | |
5296 | * @ops - the ops to set the filter with | |
5297 | * @ip - the address to add to or remove from the filter. | |
5298 | * @remove - non zero to remove the ip from the filter | |
5299 | * @reset - non zero to reset all filters before applying this filter. | |
5300 | * | |
5301 | * Filters denote which functions should be enabled when tracing is enabled | |
5302 | * If @ip is NULL, it failes to update filter. | |
5303 | */ | |
5304 | int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, | |
5305 | int remove, int reset) | |
5306 | { | |
f04f24fb | 5307 | ftrace_ops_init(ops); |
647664ea MH |
5308 | return ftrace_set_addr(ops, ip, remove, reset, 1); |
5309 | } | |
5310 | EXPORT_SYMBOL_GPL(ftrace_set_filter_ip); | |
5311 | ||
d032ae89 JF |
5312 | /** |
5313 | * ftrace_ops_set_global_filter - setup ops to use global filters | |
5314 | * @ops - the ops which will use the global filters | |
5315 | * | |
5316 | * ftrace users who need global function trace filtering should call this. | |
5317 | * It can set the global filter only if ops were not initialized before. | |
5318 | */ | |
5319 | void ftrace_ops_set_global_filter(struct ftrace_ops *ops) | |
5320 | { | |
5321 | if (ops->flags & FTRACE_OPS_FL_INITIALIZED) | |
5322 | return; | |
5323 | ||
5324 | ftrace_ops_init(ops); | |
5325 | ops->func_hash = &global_ops.local_hash; | |
5326 | } | |
5327 | EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter); | |
5328 | ||
647664ea MH |
5329 | static int |
5330 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, | |
5331 | int reset, int enable) | |
5332 | { | |
5333 | return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable); | |
5334 | } | |
5335 | ||
77a2b37d SR |
5336 | /** |
5337 | * ftrace_set_filter - set a function to filter on in ftrace | |
936e074b SR |
5338 | * @ops - the ops to set the filter with |
5339 | * @buf - the string that holds the function filter text. | |
5340 | * @len - the length of the string. | |
5341 | * @reset - non zero to reset all filters before applying this filter. | |
5342 | * | |
5343 | * Filters denote which functions should be enabled when tracing is enabled. | |
5344 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
5345 | */ | |
ac483c44 | 5346 | int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
5347 | int len, int reset) |
5348 | { | |
f04f24fb | 5349 | ftrace_ops_init(ops); |
ac483c44 | 5350 | return ftrace_set_regex(ops, buf, len, reset, 1); |
936e074b SR |
5351 | } |
5352 | EXPORT_SYMBOL_GPL(ftrace_set_filter); | |
5353 | ||
5354 | /** | |
5355 | * ftrace_set_notrace - set a function to not trace in ftrace | |
5356 | * @ops - the ops to set the notrace filter with | |
5357 | * @buf - the string that holds the function notrace text. | |
5358 | * @len - the length of the string. | |
5359 | * @reset - non zero to reset all filters before applying this filter. | |
5360 | * | |
5361 | * Notrace Filters denote which functions should not be enabled when tracing | |
5362 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
5363 | * for tracing. | |
5364 | */ | |
ac483c44 | 5365 | int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
5366 | int len, int reset) |
5367 | { | |
f04f24fb | 5368 | ftrace_ops_init(ops); |
ac483c44 | 5369 | return ftrace_set_regex(ops, buf, len, reset, 0); |
936e074b SR |
5370 | } |
5371 | EXPORT_SYMBOL_GPL(ftrace_set_notrace); | |
5372 | /** | |
8d1b065d | 5373 | * ftrace_set_global_filter - set a function to filter on with global tracers |
77a2b37d SR |
5374 | * @buf - the string that holds the function filter text. |
5375 | * @len - the length of the string. | |
5376 | * @reset - non zero to reset all filters before applying this filter. | |
5377 | * | |
5378 | * Filters denote which functions should be enabled when tracing is enabled. | |
5379 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
5380 | */ | |
936e074b | 5381 | void ftrace_set_global_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 5382 | { |
f45948e8 | 5383 | ftrace_set_regex(&global_ops, buf, len, reset, 1); |
41c52c0d | 5384 | } |
936e074b | 5385 | EXPORT_SYMBOL_GPL(ftrace_set_global_filter); |
4eebcc81 | 5386 | |
41c52c0d | 5387 | /** |
8d1b065d | 5388 | * ftrace_set_global_notrace - set a function to not trace with global tracers |
41c52c0d SR |
5389 | * @buf - the string that holds the function notrace text. |
5390 | * @len - the length of the string. | |
5391 | * @reset - non zero to reset all filters before applying this filter. | |
5392 | * | |
5393 | * Notrace Filters denote which functions should not be enabled when tracing | |
5394 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
5395 | * for tracing. | |
5396 | */ | |
936e074b | 5397 | void ftrace_set_global_notrace(unsigned char *buf, int len, int reset) |
41c52c0d | 5398 | { |
f45948e8 | 5399 | ftrace_set_regex(&global_ops, buf, len, reset, 0); |
77a2b37d | 5400 | } |
936e074b | 5401 | EXPORT_SYMBOL_GPL(ftrace_set_global_notrace); |
77a2b37d | 5402 | |
2af15d6a SR |
5403 | /* |
5404 | * command line interface to allow users to set filters on boot up. | |
5405 | */ | |
5406 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
5407 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
5408 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
5409 | ||
f1ed7c74 SRRH |
5410 | /* Used by function selftest to not test if filter is set */ |
5411 | bool ftrace_filter_param __initdata; | |
5412 | ||
2af15d6a SR |
5413 | static int __init set_ftrace_notrace(char *str) |
5414 | { | |
f1ed7c74 | 5415 | ftrace_filter_param = true; |
75761cc1 | 5416 | strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
5417 | return 1; |
5418 | } | |
5419 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
5420 | ||
5421 | static int __init set_ftrace_filter(char *str) | |
5422 | { | |
f1ed7c74 | 5423 | ftrace_filter_param = true; |
75761cc1 | 5424 | strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
5425 | return 1; |
5426 | } | |
5427 | __setup("ftrace_filter=", set_ftrace_filter); | |
5428 | ||
369bc18f | 5429 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 5430 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
0d7d9a16 | 5431 | static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata; |
b9b0c831 | 5432 | static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer); |
801c29fd | 5433 | |
369bc18f SA |
5434 | static int __init set_graph_function(char *str) |
5435 | { | |
06f43d66 | 5436 | strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
5437 | return 1; |
5438 | } | |
5439 | __setup("ftrace_graph_filter=", set_graph_function); | |
5440 | ||
0d7d9a16 NK |
5441 | static int __init set_graph_notrace_function(char *str) |
5442 | { | |
5443 | strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE); | |
5444 | return 1; | |
5445 | } | |
5446 | __setup("ftrace_graph_notrace=", set_graph_notrace_function); | |
5447 | ||
65a50c65 TB |
5448 | static int __init set_graph_max_depth_function(char *str) |
5449 | { | |
5450 | if (!str) | |
5451 | return 0; | |
5452 | fgraph_max_depth = simple_strtoul(str, NULL, 0); | |
5453 | return 1; | |
5454 | } | |
5455 | __setup("ftrace_graph_max_depth=", set_graph_max_depth_function); | |
0d7d9a16 NK |
5456 | |
5457 | static void __init set_ftrace_early_graph(char *buf, int enable) | |
369bc18f SA |
5458 | { |
5459 | int ret; | |
5460 | char *func; | |
b9b0c831 | 5461 | struct ftrace_hash *hash; |
0d7d9a16 | 5462 | |
92ad18ec | 5463 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); |
24589e3a | 5464 | if (MEM_FAIL(!hash, "Failed to allocate hash\n")) |
92ad18ec | 5465 | return; |
369bc18f SA |
5466 | |
5467 | while (buf) { | |
5468 | func = strsep(&buf, ","); | |
5469 | /* we allow only one expression at a time */ | |
b9b0c831 | 5470 | ret = ftrace_graph_set_hash(hash, func); |
369bc18f SA |
5471 | if (ret) |
5472 | printk(KERN_DEBUG "ftrace: function %s not " | |
5473 | "traceable\n", func); | |
5474 | } | |
92ad18ec SRV |
5475 | |
5476 | if (enable) | |
5477 | ftrace_graph_hash = hash; | |
5478 | else | |
5479 | ftrace_graph_notrace_hash = hash; | |
369bc18f SA |
5480 | } |
5481 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
5482 | ||
2a85a37f SR |
5483 | void __init |
5484 | ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable) | |
2af15d6a SR |
5485 | { |
5486 | char *func; | |
5487 | ||
f04f24fb MH |
5488 | ftrace_ops_init(ops); |
5489 | ||
2af15d6a SR |
5490 | while (buf) { |
5491 | func = strsep(&buf, ","); | |
f45948e8 | 5492 | ftrace_set_regex(ops, func, strlen(func), 0, enable); |
2af15d6a SR |
5493 | } |
5494 | } | |
5495 | ||
5496 | static void __init set_ftrace_early_filters(void) | |
5497 | { | |
5498 | if (ftrace_filter_buf[0]) | |
2a85a37f | 5499 | ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1); |
2af15d6a | 5500 | if (ftrace_notrace_buf[0]) |
2a85a37f | 5501 | ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0); |
369bc18f SA |
5502 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5503 | if (ftrace_graph_buf[0]) | |
0d7d9a16 NK |
5504 | set_ftrace_early_graph(ftrace_graph_buf, 1); |
5505 | if (ftrace_graph_notrace_buf[0]) | |
5506 | set_ftrace_early_graph(ftrace_graph_notrace_buf, 0); | |
369bc18f | 5507 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
2af15d6a SR |
5508 | } |
5509 | ||
fc13cb0c | 5510 | int ftrace_regex_release(struct inode *inode, struct file *file) |
5072c59f SR |
5511 | { |
5512 | struct seq_file *m = (struct seq_file *)file->private_data; | |
5513 | struct ftrace_iterator *iter; | |
33dc9b12 | 5514 | struct ftrace_hash **orig_hash; |
689fd8b6 | 5515 | struct trace_parser *parser; |
ed926f9b | 5516 | int filter_hash; |
33dc9b12 | 5517 | int ret; |
5072c59f | 5518 | |
5072c59f SR |
5519 | if (file->f_mode & FMODE_READ) { |
5520 | iter = m->private; | |
5072c59f SR |
5521 | seq_release(inode, file); |
5522 | } else | |
5523 | iter = file->private_data; | |
5524 | ||
689fd8b6 | 5525 | parser = &iter->parser; |
5526 | if (trace_parser_loaded(parser)) { | |
1cf41dd7 | 5527 | ftrace_match_records(iter->hash, parser->buffer, parser->idx); |
5072c59f SR |
5528 | } |
5529 | ||
689fd8b6 | 5530 | trace_parser_put(parser); |
689fd8b6 | 5531 | |
33b7f99c | 5532 | mutex_lock(&iter->ops->func_hash->regex_lock); |
3f2367ba | 5533 | |
058e297d | 5534 | if (file->f_mode & FMODE_WRITE) { |
ed926f9b SR |
5535 | filter_hash = !!(iter->flags & FTRACE_ITER_FILTER); |
5536 | ||
8c08f0d5 | 5537 | if (filter_hash) { |
33b7f99c | 5538 | orig_hash = &iter->ops->func_hash->filter_hash; |
69d71879 | 5539 | if (iter->tr && !list_empty(&iter->tr->mod_trace)) |
8c08f0d5 SRV |
5540 | iter->hash->flags |= FTRACE_HASH_FL_MOD; |
5541 | } else | |
33b7f99c | 5542 | orig_hash = &iter->ops->func_hash->notrace_hash; |
33dc9b12 | 5543 | |
058e297d | 5544 | mutex_lock(&ftrace_lock); |
e16b35dd SRV |
5545 | ret = ftrace_hash_move_and_update_ops(iter->ops, orig_hash, |
5546 | iter->hash, filter_hash); | |
058e297d | 5547 | mutex_unlock(&ftrace_lock); |
c20489da SRV |
5548 | } else { |
5549 | /* For read only, the hash is the ops hash */ | |
5550 | iter->hash = NULL; | |
058e297d | 5551 | } |
3f2367ba | 5552 | |
33b7f99c | 5553 | mutex_unlock(&iter->ops->func_hash->regex_lock); |
33dc9b12 | 5554 | free_ftrace_hash(iter->hash); |
9ef16693 SRV |
5555 | if (iter->tr) |
5556 | trace_array_put(iter->tr); | |
33dc9b12 | 5557 | kfree(iter); |
058e297d | 5558 | |
5072c59f SR |
5559 | return 0; |
5560 | } | |
5561 | ||
5e2336a0 | 5562 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
5563 | .open = ftrace_avail_open, |
5564 | .read = seq_read, | |
5565 | .llseek = seq_lseek, | |
3be04b47 | 5566 | .release = seq_release_private, |
5072c59f SR |
5567 | }; |
5568 | ||
647bcd03 SR |
5569 | static const struct file_operations ftrace_enabled_fops = { |
5570 | .open = ftrace_enabled_open, | |
5571 | .read = seq_read, | |
5572 | .llseek = seq_lseek, | |
5573 | .release = seq_release_private, | |
5574 | }; | |
5575 | ||
5e2336a0 | 5576 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 5577 | .open = ftrace_filter_open, |
850a80cf | 5578 | .read = seq_read, |
5072c59f | 5579 | .write = ftrace_filter_write, |
098c879e | 5580 | .llseek = tracing_lseek, |
1cf41dd7 | 5581 | .release = ftrace_regex_release, |
5072c59f SR |
5582 | }; |
5583 | ||
5e2336a0 | 5584 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 5585 | .open = ftrace_notrace_open, |
850a80cf | 5586 | .read = seq_read, |
41c52c0d | 5587 | .write = ftrace_notrace_write, |
098c879e | 5588 | .llseek = tracing_lseek, |
1cf41dd7 | 5589 | .release = ftrace_regex_release, |
41c52c0d SR |
5590 | }; |
5591 | ||
ea4e2bc4 SR |
5592 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5593 | ||
5594 | static DEFINE_MUTEX(graph_lock); | |
5595 | ||
24a9729f | 5596 | struct ftrace_hash __rcu *ftrace_graph_hash = EMPTY_HASH; |
fd0e6852 | 5597 | struct ftrace_hash __rcu *ftrace_graph_notrace_hash = EMPTY_HASH; |
b9b0c831 NK |
5598 | |
5599 | enum graph_filter_type { | |
5600 | GRAPH_FILTER_NOTRACE = 0, | |
5601 | GRAPH_FILTER_FUNCTION, | |
5602 | }; | |
ea4e2bc4 | 5603 | |
555fc781 SRV |
5604 | #define FTRACE_GRAPH_EMPTY ((void *)1) |
5605 | ||
faf982a6 | 5606 | struct ftrace_graph_data { |
e704eff3 SRV |
5607 | struct ftrace_hash *hash; |
5608 | struct ftrace_func_entry *entry; | |
5609 | int idx; /* for hash table iteration */ | |
5610 | enum graph_filter_type type; | |
5611 | struct ftrace_hash *new_hash; | |
5612 | const struct seq_operations *seq_ops; | |
5613 | struct trace_parser parser; | |
faf982a6 NK |
5614 | }; |
5615 | ||
ea4e2bc4 | 5616 | static void * |
85951842 | 5617 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 5618 | { |
faf982a6 | 5619 | struct ftrace_graph_data *fgd = m->private; |
b9b0c831 NK |
5620 | struct ftrace_func_entry *entry = fgd->entry; |
5621 | struct hlist_head *head; | |
5622 | int i, idx = fgd->idx; | |
faf982a6 | 5623 | |
b9b0c831 | 5624 | if (*pos >= fgd->hash->count) |
ea4e2bc4 | 5625 | return NULL; |
b9b0c831 NK |
5626 | |
5627 | if (entry) { | |
5628 | hlist_for_each_entry_continue(entry, hlist) { | |
5629 | fgd->entry = entry; | |
5630 | return entry; | |
5631 | } | |
5632 | ||
5633 | idx++; | |
5634 | } | |
5635 | ||
5636 | for (i = idx; i < 1 << fgd->hash->size_bits; i++) { | |
5637 | head = &fgd->hash->buckets[i]; | |
5638 | hlist_for_each_entry(entry, head, hlist) { | |
5639 | fgd->entry = entry; | |
5640 | fgd->idx = i; | |
5641 | return entry; | |
5642 | } | |
5643 | } | |
5644 | return NULL; | |
85951842 | 5645 | } |
ea4e2bc4 | 5646 | |
85951842 LZ |
5647 | static void * |
5648 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
5649 | { | |
5650 | (*pos)++; | |
5651 | return __g_next(m, pos); | |
ea4e2bc4 SR |
5652 | } |
5653 | ||
5654 | static void *g_start(struct seq_file *m, loff_t *pos) | |
5655 | { | |
faf982a6 NK |
5656 | struct ftrace_graph_data *fgd = m->private; |
5657 | ||
ea4e2bc4 SR |
5658 | mutex_lock(&graph_lock); |
5659 | ||
649b988b SRV |
5660 | if (fgd->type == GRAPH_FILTER_FUNCTION) |
5661 | fgd->hash = rcu_dereference_protected(ftrace_graph_hash, | |
5662 | lockdep_is_held(&graph_lock)); | |
5663 | else | |
5664 | fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash, | |
5665 | lockdep_is_held(&graph_lock)); | |
5666 | ||
f9349a8f | 5667 | /* Nothing, tell g_show to print all functions are enabled */ |
b9b0c831 | 5668 | if (ftrace_hash_empty(fgd->hash) && !*pos) |
555fc781 | 5669 | return FTRACE_GRAPH_EMPTY; |
f9349a8f | 5670 | |
b9b0c831 NK |
5671 | fgd->idx = 0; |
5672 | fgd->entry = NULL; | |
85951842 | 5673 | return __g_next(m, pos); |
ea4e2bc4 SR |
5674 | } |
5675 | ||
5676 | static void g_stop(struct seq_file *m, void *p) | |
5677 | { | |
5678 | mutex_unlock(&graph_lock); | |
5679 | } | |
5680 | ||
5681 | static int g_show(struct seq_file *m, void *v) | |
5682 | { | |
b9b0c831 | 5683 | struct ftrace_func_entry *entry = v; |
ea4e2bc4 | 5684 | |
b9b0c831 | 5685 | if (!entry) |
ea4e2bc4 SR |
5686 | return 0; |
5687 | ||
555fc781 | 5688 | if (entry == FTRACE_GRAPH_EMPTY) { |
280d1429 NK |
5689 | struct ftrace_graph_data *fgd = m->private; |
5690 | ||
b9b0c831 | 5691 | if (fgd->type == GRAPH_FILTER_FUNCTION) |
fa6f0cc7 | 5692 | seq_puts(m, "#### all functions enabled ####\n"); |
280d1429 | 5693 | else |
fa6f0cc7 | 5694 | seq_puts(m, "#### no functions disabled ####\n"); |
f9349a8f FW |
5695 | return 0; |
5696 | } | |
5697 | ||
b9b0c831 | 5698 | seq_printf(m, "%ps\n", (void *)entry->ip); |
ea4e2bc4 SR |
5699 | |
5700 | return 0; | |
5701 | } | |
5702 | ||
88e9d34c | 5703 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
5704 | .start = g_start, |
5705 | .next = g_next, | |
5706 | .stop = g_stop, | |
5707 | .show = g_show, | |
5708 | }; | |
5709 | ||
5710 | static int | |
faf982a6 NK |
5711 | __ftrace_graph_open(struct inode *inode, struct file *file, |
5712 | struct ftrace_graph_data *fgd) | |
ea4e2bc4 | 5713 | { |
17911ff3 | 5714 | int ret; |
b9b0c831 | 5715 | struct ftrace_hash *new_hash = NULL; |
ea4e2bc4 | 5716 | |
17911ff3 SRV |
5717 | ret = security_locked_down(LOCKDOWN_TRACEFS); |
5718 | if (ret) | |
5719 | return ret; | |
5720 | ||
b9b0c831 NK |
5721 | if (file->f_mode & FMODE_WRITE) { |
5722 | const int size_bits = FTRACE_HASH_DEFAULT_BITS; | |
5723 | ||
e704eff3 SRV |
5724 | if (trace_parser_get_init(&fgd->parser, FTRACE_BUFF_MAX)) |
5725 | return -ENOMEM; | |
5726 | ||
b9b0c831 NK |
5727 | if (file->f_flags & O_TRUNC) |
5728 | new_hash = alloc_ftrace_hash(size_bits); | |
5729 | else | |
5730 | new_hash = alloc_and_copy_ftrace_hash(size_bits, | |
5731 | fgd->hash); | |
5732 | if (!new_hash) { | |
5733 | ret = -ENOMEM; | |
5734 | goto out; | |
5735 | } | |
ea4e2bc4 SR |
5736 | } |
5737 | ||
faf982a6 | 5738 | if (file->f_mode & FMODE_READ) { |
b9b0c831 | 5739 | ret = seq_open(file, &ftrace_graph_seq_ops); |
faf982a6 NK |
5740 | if (!ret) { |
5741 | struct seq_file *m = file->private_data; | |
5742 | m->private = fgd; | |
b9b0c831 NK |
5743 | } else { |
5744 | /* Failed */ | |
5745 | free_ftrace_hash(new_hash); | |
5746 | new_hash = NULL; | |
faf982a6 NK |
5747 | } |
5748 | } else | |
5749 | file->private_data = fgd; | |
ea4e2bc4 | 5750 | |
b9b0c831 | 5751 | out: |
e704eff3 SRV |
5752 | if (ret < 0 && file->f_mode & FMODE_WRITE) |
5753 | trace_parser_put(&fgd->parser); | |
5754 | ||
b9b0c831 | 5755 | fgd->new_hash = new_hash; |
649b988b SRV |
5756 | |
5757 | /* | |
5758 | * All uses of fgd->hash must be taken with the graph_lock | |
5759 | * held. The graph_lock is going to be released, so force | |
5760 | * fgd->hash to be reinitialized when it is taken again. | |
5761 | */ | |
5762 | fgd->hash = NULL; | |
5763 | ||
ea4e2bc4 SR |
5764 | return ret; |
5765 | } | |
5766 | ||
faf982a6 NK |
5767 | static int |
5768 | ftrace_graph_open(struct inode *inode, struct file *file) | |
5769 | { | |
5770 | struct ftrace_graph_data *fgd; | |
b9b0c831 | 5771 | int ret; |
faf982a6 NK |
5772 | |
5773 | if (unlikely(ftrace_disabled)) | |
5774 | return -ENODEV; | |
5775 | ||
5776 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
5777 | if (fgd == NULL) | |
5778 | return -ENOMEM; | |
5779 | ||
b9b0c831 NK |
5780 | mutex_lock(&graph_lock); |
5781 | ||
649b988b SRV |
5782 | fgd->hash = rcu_dereference_protected(ftrace_graph_hash, |
5783 | lockdep_is_held(&graph_lock)); | |
b9b0c831 | 5784 | fgd->type = GRAPH_FILTER_FUNCTION; |
faf982a6 NK |
5785 | fgd->seq_ops = &ftrace_graph_seq_ops; |
5786 | ||
b9b0c831 NK |
5787 | ret = __ftrace_graph_open(inode, file, fgd); |
5788 | if (ret < 0) | |
5789 | kfree(fgd); | |
5790 | ||
5791 | mutex_unlock(&graph_lock); | |
5792 | return ret; | |
faf982a6 NK |
5793 | } |
5794 | ||
29ad23b0 NK |
5795 | static int |
5796 | ftrace_graph_notrace_open(struct inode *inode, struct file *file) | |
5797 | { | |
5798 | struct ftrace_graph_data *fgd; | |
b9b0c831 | 5799 | int ret; |
29ad23b0 NK |
5800 | |
5801 | if (unlikely(ftrace_disabled)) | |
5802 | return -ENODEV; | |
5803 | ||
5804 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
5805 | if (fgd == NULL) | |
5806 | return -ENOMEM; | |
5807 | ||
b9b0c831 NK |
5808 | mutex_lock(&graph_lock); |
5809 | ||
649b988b SRV |
5810 | fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash, |
5811 | lockdep_is_held(&graph_lock)); | |
b9b0c831 | 5812 | fgd->type = GRAPH_FILTER_NOTRACE; |
29ad23b0 NK |
5813 | fgd->seq_ops = &ftrace_graph_seq_ops; |
5814 | ||
b9b0c831 NK |
5815 | ret = __ftrace_graph_open(inode, file, fgd); |
5816 | if (ret < 0) | |
5817 | kfree(fgd); | |
5818 | ||
5819 | mutex_unlock(&graph_lock); | |
5820 | return ret; | |
29ad23b0 NK |
5821 | } |
5822 | ||
87827111 LZ |
5823 | static int |
5824 | ftrace_graph_release(struct inode *inode, struct file *file) | |
5825 | { | |
b9b0c831 | 5826 | struct ftrace_graph_data *fgd; |
e704eff3 SRV |
5827 | struct ftrace_hash *old_hash, *new_hash; |
5828 | struct trace_parser *parser; | |
5829 | int ret = 0; | |
b9b0c831 | 5830 | |
faf982a6 NK |
5831 | if (file->f_mode & FMODE_READ) { |
5832 | struct seq_file *m = file->private_data; | |
5833 | ||
b9b0c831 | 5834 | fgd = m->private; |
87827111 | 5835 | seq_release(inode, file); |
faf982a6 | 5836 | } else { |
b9b0c831 | 5837 | fgd = file->private_data; |
faf982a6 NK |
5838 | } |
5839 | ||
e704eff3 SRV |
5840 | |
5841 | if (file->f_mode & FMODE_WRITE) { | |
5842 | ||
5843 | parser = &fgd->parser; | |
5844 | ||
5845 | if (trace_parser_loaded((parser))) { | |
e704eff3 SRV |
5846 | ret = ftrace_graph_set_hash(fgd->new_hash, |
5847 | parser->buffer); | |
5848 | } | |
5849 | ||
5850 | trace_parser_put(parser); | |
5851 | ||
5852 | new_hash = __ftrace_hash_move(fgd->new_hash); | |
5853 | if (!new_hash) { | |
5854 | ret = -ENOMEM; | |
5855 | goto out; | |
5856 | } | |
5857 | ||
5858 | mutex_lock(&graph_lock); | |
5859 | ||
5860 | if (fgd->type == GRAPH_FILTER_FUNCTION) { | |
5861 | old_hash = rcu_dereference_protected(ftrace_graph_hash, | |
5862 | lockdep_is_held(&graph_lock)); | |
5863 | rcu_assign_pointer(ftrace_graph_hash, new_hash); | |
5864 | } else { | |
5865 | old_hash = rcu_dereference_protected(ftrace_graph_notrace_hash, | |
5866 | lockdep_is_held(&graph_lock)); | |
5867 | rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash); | |
5868 | } | |
5869 | ||
5870 | mutex_unlock(&graph_lock); | |
5871 | ||
54a16ff6 SRV |
5872 | /* |
5873 | * We need to do a hard force of sched synchronization. | |
5874 | * This is because we use preempt_disable() to do RCU, but | |
5875 | * the function tracers can be called where RCU is not watching | |
5876 | * (like before user_exit()). We can not rely on the RCU | |
5877 | * infrastructure to do the synchronization, thus we must do it | |
5878 | * ourselves. | |
5879 | */ | |
5880 | schedule_on_each_cpu(ftrace_sync); | |
e704eff3 SRV |
5881 | |
5882 | free_ftrace_hash(old_hash); | |
5883 | } | |
5884 | ||
5885 | out: | |
f9797c2f | 5886 | free_ftrace_hash(fgd->new_hash); |
b9b0c831 NK |
5887 | kfree(fgd); |
5888 | ||
e704eff3 | 5889 | return ret; |
87827111 LZ |
5890 | } |
5891 | ||
ea4e2bc4 | 5892 | static int |
b9b0c831 | 5893 | ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer) |
ea4e2bc4 | 5894 | { |
3ba00929 | 5895 | struct ftrace_glob func_g; |
ea4e2bc4 SR |
5896 | struct dyn_ftrace *rec; |
5897 | struct ftrace_page *pg; | |
b9b0c831 | 5898 | struct ftrace_func_entry *entry; |
c7c6b1fe | 5899 | int fail = 1; |
3ba00929 | 5900 | int not; |
ea4e2bc4 | 5901 | |
f9349a8f | 5902 | /* decode regex */ |
3ba00929 DS |
5903 | func_g.type = filter_parse_regex(buffer, strlen(buffer), |
5904 | &func_g.search, ¬); | |
f9349a8f | 5905 | |
3ba00929 | 5906 | func_g.len = strlen(func_g.search); |
f9349a8f | 5907 | |
52baf119 | 5908 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
5909 | |
5910 | if (unlikely(ftrace_disabled)) { | |
5911 | mutex_unlock(&ftrace_lock); | |
5912 | return -ENODEV; | |
5913 | } | |
5914 | ||
265c831c SR |
5915 | do_for_each_ftrace_rec(pg, rec) { |
5916 | ||
546fece4 SRRH |
5917 | if (rec->flags & FTRACE_FL_DISABLED) |
5918 | continue; | |
5919 | ||
0b507e1e | 5920 | if (ftrace_match_record(rec, &func_g, NULL, 0)) { |
b9b0c831 | 5921 | entry = ftrace_lookup_ip(hash, rec->ip); |
c7c6b1fe LZ |
5922 | |
5923 | if (!not) { | |
5924 | fail = 0; | |
b9b0c831 NK |
5925 | |
5926 | if (entry) | |
5927 | continue; | |
5928 | if (add_hash_entry(hash, rec->ip) < 0) | |
5929 | goto out; | |
c7c6b1fe | 5930 | } else { |
b9b0c831 NK |
5931 | if (entry) { |
5932 | free_hash_entry(hash, entry); | |
c7c6b1fe LZ |
5933 | fail = 0; |
5934 | } | |
5935 | } | |
ea4e2bc4 | 5936 | } |
265c831c | 5937 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 5938 | out: |
52baf119 | 5939 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 5940 | |
c7c6b1fe LZ |
5941 | if (fail) |
5942 | return -EINVAL; | |
5943 | ||
c7c6b1fe | 5944 | return 0; |
ea4e2bc4 SR |
5945 | } |
5946 | ||
5947 | static ssize_t | |
5948 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
5949 | size_t cnt, loff_t *ppos) | |
5950 | { | |
6a10108b | 5951 | ssize_t read, ret = 0; |
faf982a6 | 5952 | struct ftrace_graph_data *fgd = file->private_data; |
e704eff3 | 5953 | struct trace_parser *parser; |
ea4e2bc4 | 5954 | |
c7c6b1fe | 5955 | if (!cnt) |
ea4e2bc4 SR |
5956 | return 0; |
5957 | ||
ae98d27a SRV |
5958 | /* Read mode uses seq functions */ |
5959 | if (file->f_mode & FMODE_READ) { | |
5960 | struct seq_file *m = file->private_data; | |
5961 | fgd = m->private; | |
5962 | } | |
5963 | ||
e704eff3 | 5964 | parser = &fgd->parser; |
ea4e2bc4 | 5965 | |
e704eff3 | 5966 | read = trace_get_user(parser, ubuf, cnt, ppos); |
689fd8b6 | 5967 | |
e704eff3 SRV |
5968 | if (read >= 0 && trace_parser_loaded(parser) && |
5969 | !trace_parser_cont(parser)) { | |
6a10108b | 5970 | |
b9b0c831 | 5971 | ret = ftrace_graph_set_hash(fgd->new_hash, |
e704eff3 SRV |
5972 | parser->buffer); |
5973 | trace_parser_clear(parser); | |
ea4e2bc4 | 5974 | } |
ea4e2bc4 | 5975 | |
6a10108b NK |
5976 | if (!ret) |
5977 | ret = read; | |
1eb90f13 | 5978 | |
ea4e2bc4 SR |
5979 | return ret; |
5980 | } | |
5981 | ||
5982 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
5983 | .open = ftrace_graph_open, |
5984 | .read = seq_read, | |
5985 | .write = ftrace_graph_write, | |
098c879e | 5986 | .llseek = tracing_lseek, |
87827111 | 5987 | .release = ftrace_graph_release, |
ea4e2bc4 | 5988 | }; |
29ad23b0 NK |
5989 | |
5990 | static const struct file_operations ftrace_graph_notrace_fops = { | |
5991 | .open = ftrace_graph_notrace_open, | |
5992 | .read = seq_read, | |
5993 | .write = ftrace_graph_write, | |
098c879e | 5994 | .llseek = tracing_lseek, |
29ad23b0 NK |
5995 | .release = ftrace_graph_release, |
5996 | }; | |
ea4e2bc4 SR |
5997 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
5998 | ||
591dffda SRRH |
5999 | void ftrace_create_filter_files(struct ftrace_ops *ops, |
6000 | struct dentry *parent) | |
6001 | { | |
6002 | ||
6003 | trace_create_file("set_ftrace_filter", 0644, parent, | |
6004 | ops, &ftrace_filter_fops); | |
6005 | ||
6006 | trace_create_file("set_ftrace_notrace", 0644, parent, | |
6007 | ops, &ftrace_notrace_fops); | |
6008 | } | |
6009 | ||
6010 | /* | |
6011 | * The name "destroy_filter_files" is really a misnomer. Although | |
9efb85c5 | 6012 | * in the future, it may actually delete the files, but this is |
591dffda SRRH |
6013 | * really intended to make sure the ops passed in are disabled |
6014 | * and that when this function returns, the caller is free to | |
6015 | * free the ops. | |
6016 | * | |
6017 | * The "destroy" name is only to match the "create" name that this | |
6018 | * should be paired with. | |
6019 | */ | |
6020 | void ftrace_destroy_filter_files(struct ftrace_ops *ops) | |
6021 | { | |
6022 | mutex_lock(&ftrace_lock); | |
6023 | if (ops->flags & FTRACE_OPS_FL_ENABLED) | |
6024 | ftrace_shutdown(ops, 0); | |
6025 | ops->flags |= FTRACE_OPS_FL_DELETED; | |
2840f84f | 6026 | ftrace_free_filter(ops); |
591dffda SRRH |
6027 | mutex_unlock(&ftrace_lock); |
6028 | } | |
6029 | ||
8434dc93 | 6030 | static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer) |
5072c59f | 6031 | { |
5072c59f | 6032 | |
5452af66 FW |
6033 | trace_create_file("available_filter_functions", 0444, |
6034 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 6035 | |
647bcd03 SR |
6036 | trace_create_file("enabled_functions", 0444, |
6037 | d_tracer, NULL, &ftrace_enabled_fops); | |
6038 | ||
591dffda | 6039 | ftrace_create_filter_files(&global_ops, d_tracer); |
ad90c0e3 | 6040 | |
ea4e2bc4 | 6041 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
1ce0500d | 6042 | trace_create_file("set_graph_function", 0644, d_tracer, |
ea4e2bc4 SR |
6043 | NULL, |
6044 | &ftrace_graph_fops); | |
1ce0500d | 6045 | trace_create_file("set_graph_notrace", 0644, d_tracer, |
29ad23b0 NK |
6046 | NULL, |
6047 | &ftrace_graph_notrace_fops); | |
ea4e2bc4 SR |
6048 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
6049 | ||
5072c59f SR |
6050 | return 0; |
6051 | } | |
6052 | ||
9fd49328 | 6053 | static int ftrace_cmp_ips(const void *a, const void *b) |
68950619 | 6054 | { |
9fd49328 SR |
6055 | const unsigned long *ipa = a; |
6056 | const unsigned long *ipb = b; | |
68950619 | 6057 | |
9fd49328 SR |
6058 | if (*ipa > *ipb) |
6059 | return 1; | |
6060 | if (*ipa < *ipb) | |
6061 | return -1; | |
6062 | return 0; | |
6063 | } | |
6064 | ||
5cb084bb | 6065 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 6066 | unsigned long *start, |
68bf21aa SR |
6067 | unsigned long *end) |
6068 | { | |
706c81f8 | 6069 | struct ftrace_page *start_pg; |
a7900875 | 6070 | struct ftrace_page *pg; |
706c81f8 | 6071 | struct dyn_ftrace *rec; |
a7900875 | 6072 | unsigned long count; |
68bf21aa SR |
6073 | unsigned long *p; |
6074 | unsigned long addr; | |
4376cac6 | 6075 | unsigned long flags = 0; /* Shut up gcc */ |
a7900875 SR |
6076 | int ret = -ENOMEM; |
6077 | ||
6078 | count = end - start; | |
6079 | ||
6080 | if (!count) | |
6081 | return 0; | |
6082 | ||
9fd49328 | 6083 | sort(start, count, sizeof(*start), |
6db02903 | 6084 | ftrace_cmp_ips, NULL); |
9fd49328 | 6085 | |
706c81f8 SR |
6086 | start_pg = ftrace_allocate_pages(count); |
6087 | if (!start_pg) | |
a7900875 | 6088 | return -ENOMEM; |
68bf21aa | 6089 | |
e6ea44e9 | 6090 | mutex_lock(&ftrace_lock); |
a7900875 | 6091 | |
32082309 SR |
6092 | /* |
6093 | * Core and each module needs their own pages, as | |
6094 | * modules will free them when they are removed. | |
6095 | * Force a new page to be allocated for modules. | |
6096 | */ | |
a7900875 SR |
6097 | if (!mod) { |
6098 | WARN_ON(ftrace_pages || ftrace_pages_start); | |
6099 | /* First initialization */ | |
706c81f8 | 6100 | ftrace_pages = ftrace_pages_start = start_pg; |
a7900875 | 6101 | } else { |
32082309 | 6102 | if (!ftrace_pages) |
a7900875 | 6103 | goto out; |
32082309 | 6104 | |
a7900875 SR |
6105 | if (WARN_ON(ftrace_pages->next)) { |
6106 | /* Hmm, we have free pages? */ | |
6107 | while (ftrace_pages->next) | |
6108 | ftrace_pages = ftrace_pages->next; | |
32082309 | 6109 | } |
a7900875 | 6110 | |
706c81f8 | 6111 | ftrace_pages->next = start_pg; |
32082309 SR |
6112 | } |
6113 | ||
68bf21aa | 6114 | p = start; |
706c81f8 | 6115 | pg = start_pg; |
68bf21aa SR |
6116 | while (p < end) { |
6117 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
6118 | /* |
6119 | * Some architecture linkers will pad between | |
6120 | * the different mcount_loc sections of different | |
6121 | * object files to satisfy alignments. | |
6122 | * Skip any NULL pointers. | |
6123 | */ | |
6124 | if (!addr) | |
6125 | continue; | |
706c81f8 SR |
6126 | |
6127 | if (pg->index == pg->size) { | |
6128 | /* We should have allocated enough */ | |
6129 | if (WARN_ON(!pg->next)) | |
6130 | break; | |
6131 | pg = pg->next; | |
6132 | } | |
6133 | ||
6134 | rec = &pg->records[pg->index++]; | |
6135 | rec->ip = addr; | |
68bf21aa SR |
6136 | } |
6137 | ||
706c81f8 SR |
6138 | /* We should have used all pages */ |
6139 | WARN_ON(pg->next); | |
6140 | ||
6141 | /* Assign the last page to ftrace_pages */ | |
6142 | ftrace_pages = pg; | |
6143 | ||
a4f18ed1 | 6144 | /* |
4376cac6 SR |
6145 | * We only need to disable interrupts on start up |
6146 | * because we are modifying code that an interrupt | |
6147 | * may execute, and the modification is not atomic. | |
6148 | * But for modules, nothing runs the code we modify | |
6149 | * until we are finished with it, and there's no | |
6150 | * reason to cause large interrupt latencies while we do it. | |
a4f18ed1 | 6151 | */ |
4376cac6 SR |
6152 | if (!mod) |
6153 | local_irq_save(flags); | |
1dc43cf0 | 6154 | ftrace_update_code(mod, start_pg); |
4376cac6 SR |
6155 | if (!mod) |
6156 | local_irq_restore(flags); | |
a7900875 SR |
6157 | ret = 0; |
6158 | out: | |
e6ea44e9 | 6159 | mutex_unlock(&ftrace_lock); |
68bf21aa | 6160 | |
a7900875 | 6161 | return ret; |
68bf21aa SR |
6162 | } |
6163 | ||
aba4b5c2 SRV |
6164 | struct ftrace_mod_func { |
6165 | struct list_head list; | |
6166 | char *name; | |
6167 | unsigned long ip; | |
6168 | unsigned int size; | |
6169 | }; | |
6170 | ||
6171 | struct ftrace_mod_map { | |
6aa69784 | 6172 | struct rcu_head rcu; |
aba4b5c2 SRV |
6173 | struct list_head list; |
6174 | struct module *mod; | |
6175 | unsigned long start_addr; | |
6176 | unsigned long end_addr; | |
6177 | struct list_head funcs; | |
6171a031 | 6178 | unsigned int num_funcs; |
aba4b5c2 SRV |
6179 | }; |
6180 | ||
93eb677d | 6181 | #ifdef CONFIG_MODULES |
32082309 SR |
6182 | |
6183 | #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next) | |
6184 | ||
6aa69784 SRV |
6185 | static LIST_HEAD(ftrace_mod_maps); |
6186 | ||
b7ffffbb SRRH |
6187 | static int referenced_filters(struct dyn_ftrace *rec) |
6188 | { | |
6189 | struct ftrace_ops *ops; | |
6190 | int cnt = 0; | |
6191 | ||
6192 | for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) { | |
6193 | if (ops_references_rec(ops, rec)) | |
6194 | cnt++; | |
6195 | } | |
6196 | ||
6197 | return cnt; | |
6198 | } | |
6199 | ||
2a5bfe47 SRV |
6200 | static void |
6201 | clear_mod_from_hash(struct ftrace_page *pg, struct ftrace_hash *hash) | |
6202 | { | |
6203 | struct ftrace_func_entry *entry; | |
6204 | struct dyn_ftrace *rec; | |
6205 | int i; | |
6206 | ||
6207 | if (ftrace_hash_empty(hash)) | |
6208 | return; | |
6209 | ||
6210 | for (i = 0; i < pg->index; i++) { | |
6211 | rec = &pg->records[i]; | |
6212 | entry = __ftrace_lookup_ip(hash, rec->ip); | |
6213 | /* | |
6214 | * Do not allow this rec to match again. | |
6215 | * Yeah, it may waste some memory, but will be removed | |
6216 | * if/when the hash is modified again. | |
6217 | */ | |
6218 | if (entry) | |
6219 | entry->ip = 0; | |
6220 | } | |
6221 | } | |
6222 | ||
6223 | /* Clear any records from hashs */ | |
6224 | static void clear_mod_from_hashes(struct ftrace_page *pg) | |
6225 | { | |
6226 | struct trace_array *tr; | |
6227 | ||
6228 | mutex_lock(&trace_types_lock); | |
6229 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
6230 | if (!tr->ops || !tr->ops->func_hash) | |
6231 | continue; | |
6232 | mutex_lock(&tr->ops->func_hash->regex_lock); | |
6233 | clear_mod_from_hash(pg, tr->ops->func_hash->filter_hash); | |
6234 | clear_mod_from_hash(pg, tr->ops->func_hash->notrace_hash); | |
6235 | mutex_unlock(&tr->ops->func_hash->regex_lock); | |
6236 | } | |
6237 | mutex_unlock(&trace_types_lock); | |
6238 | } | |
6239 | ||
6aa69784 SRV |
6240 | static void ftrace_free_mod_map(struct rcu_head *rcu) |
6241 | { | |
6242 | struct ftrace_mod_map *mod_map = container_of(rcu, struct ftrace_mod_map, rcu); | |
6243 | struct ftrace_mod_func *mod_func; | |
6244 | struct ftrace_mod_func *n; | |
6245 | ||
6246 | /* All the contents of mod_map are now not visible to readers */ | |
6247 | list_for_each_entry_safe(mod_func, n, &mod_map->funcs, list) { | |
6248 | kfree(mod_func->name); | |
6249 | list_del(&mod_func->list); | |
6250 | kfree(mod_func); | |
6251 | } | |
6252 | ||
6253 | kfree(mod_map); | |
6254 | } | |
6255 | ||
e7247a15 | 6256 | void ftrace_release_mod(struct module *mod) |
93eb677d | 6257 | { |
6aa69784 SRV |
6258 | struct ftrace_mod_map *mod_map; |
6259 | struct ftrace_mod_map *n; | |
93eb677d | 6260 | struct dyn_ftrace *rec; |
32082309 | 6261 | struct ftrace_page **last_pg; |
2a5bfe47 | 6262 | struct ftrace_page *tmp_page = NULL; |
93eb677d | 6263 | struct ftrace_page *pg; |
a7900875 | 6264 | int order; |
93eb677d | 6265 | |
45a4a237 SR |
6266 | mutex_lock(&ftrace_lock); |
6267 | ||
e7247a15 | 6268 | if (ftrace_disabled) |
45a4a237 | 6269 | goto out_unlock; |
93eb677d | 6270 | |
6aa69784 SRV |
6271 | list_for_each_entry_safe(mod_map, n, &ftrace_mod_maps, list) { |
6272 | if (mod_map->mod == mod) { | |
6273 | list_del_rcu(&mod_map->list); | |
74401729 | 6274 | call_rcu(&mod_map->rcu, ftrace_free_mod_map); |
6aa69784 SRV |
6275 | break; |
6276 | } | |
6277 | } | |
6278 | ||
32082309 SR |
6279 | /* |
6280 | * Each module has its own ftrace_pages, remove | |
6281 | * them from the list. | |
6282 | */ | |
6283 | last_pg = &ftrace_pages_start; | |
6284 | for (pg = ftrace_pages_start; pg; pg = *last_pg) { | |
6285 | rec = &pg->records[0]; | |
3e234289 SRV |
6286 | if (within_module_core(rec->ip, mod) || |
6287 | within_module_init(rec->ip, mod)) { | |
93eb677d | 6288 | /* |
32082309 SR |
6289 | * As core pages are first, the first |
6290 | * page should never be a module page. | |
93eb677d | 6291 | */ |
32082309 SR |
6292 | if (WARN_ON(pg == ftrace_pages_start)) |
6293 | goto out_unlock; | |
6294 | ||
6295 | /* Check if we are deleting the last page */ | |
6296 | if (pg == ftrace_pages) | |
6297 | ftrace_pages = next_to_ftrace_page(last_pg); | |
6298 | ||
83dd1493 | 6299 | ftrace_update_tot_cnt -= pg->index; |
32082309 | 6300 | *last_pg = pg->next; |
2a5bfe47 SRV |
6301 | |
6302 | pg->next = tmp_page; | |
6303 | tmp_page = pg; | |
32082309 SR |
6304 | } else |
6305 | last_pg = &pg->next; | |
6306 | } | |
45a4a237 | 6307 | out_unlock: |
93eb677d | 6308 | mutex_unlock(&ftrace_lock); |
2a5bfe47 SRV |
6309 | |
6310 | for (pg = tmp_page; pg; pg = tmp_page) { | |
6311 | ||
6312 | /* Needs to be called outside of ftrace_lock */ | |
6313 | clear_mod_from_hashes(pg); | |
6314 | ||
6315 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); | |
6316 | free_pages((unsigned long)pg->records, order); | |
6317 | tmp_page = pg->next; | |
6318 | kfree(pg); | |
da537f0a SRV |
6319 | ftrace_number_of_pages -= 1 << order; |
6320 | ftrace_number_of_groups--; | |
2a5bfe47 | 6321 | } |
93eb677d SR |
6322 | } |
6323 | ||
7dcd182b | 6324 | void ftrace_module_enable(struct module *mod) |
b7ffffbb SRRH |
6325 | { |
6326 | struct dyn_ftrace *rec; | |
6327 | struct ftrace_page *pg; | |
6328 | ||
6329 | mutex_lock(&ftrace_lock); | |
6330 | ||
6331 | if (ftrace_disabled) | |
6332 | goto out_unlock; | |
6333 | ||
6334 | /* | |
6335 | * If the tracing is enabled, go ahead and enable the record. | |
6336 | * | |
9efb85c5 | 6337 | * The reason not to enable the record immediately is the |
b7ffffbb SRRH |
6338 | * inherent check of ftrace_make_nop/ftrace_make_call for |
6339 | * correct previous instructions. Making first the NOP | |
6340 | * conversion puts the module to the correct state, thus | |
6341 | * passing the ftrace_make_call check. | |
6342 | * | |
6343 | * We also delay this to after the module code already set the | |
6344 | * text to read-only, as we now need to set it back to read-write | |
6345 | * so that we can modify the text. | |
6346 | */ | |
6347 | if (ftrace_start_up) | |
6348 | ftrace_arch_code_modify_prepare(); | |
6349 | ||
6350 | do_for_each_ftrace_rec(pg, rec) { | |
6351 | int cnt; | |
6352 | /* | |
6353 | * do_for_each_ftrace_rec() is a double loop. | |
6354 | * module text shares the pg. If a record is | |
6355 | * not part of this module, then skip this pg, | |
6356 | * which the "break" will do. | |
6357 | */ | |
3e234289 SRV |
6358 | if (!within_module_core(rec->ip, mod) && |
6359 | !within_module_init(rec->ip, mod)) | |
b7ffffbb SRRH |
6360 | break; |
6361 | ||
6362 | cnt = 0; | |
6363 | ||
6364 | /* | |
6365 | * When adding a module, we need to check if tracers are | |
6366 | * currently enabled and if they are, and can trace this record, | |
6367 | * we need to enable the module functions as well as update the | |
6368 | * reference counts for those function records. | |
6369 | */ | |
6370 | if (ftrace_start_up) | |
6371 | cnt += referenced_filters(rec); | |
6372 | ||
6373 | /* This clears FTRACE_FL_DISABLED */ | |
6374 | rec->flags = cnt; | |
6375 | ||
6376 | if (ftrace_start_up && cnt) { | |
6377 | int failed = __ftrace_replace_code(rec, 1); | |
6378 | if (failed) { | |
6379 | ftrace_bug(failed, rec); | |
6380 | goto out_loop; | |
6381 | } | |
6382 | } | |
6383 | ||
6384 | } while_for_each_ftrace_rec(); | |
6385 | ||
6386 | out_loop: | |
6387 | if (ftrace_start_up) | |
6388 | ftrace_arch_code_modify_post_process(); | |
6389 | ||
6390 | out_unlock: | |
6391 | mutex_unlock(&ftrace_lock); | |
d7fbf8df SRV |
6392 | |
6393 | process_cached_mods(mod->name); | |
b7ffffbb SRRH |
6394 | } |
6395 | ||
b6b71f66 | 6396 | void ftrace_module_init(struct module *mod) |
90d595fe | 6397 | { |
97e9b4fc | 6398 | if (ftrace_disabled || !mod->num_ftrace_callsites) |
fed1939c | 6399 | return; |
90d595fe | 6400 | |
97e9b4fc SRRH |
6401 | ftrace_process_locs(mod, mod->ftrace_callsites, |
6402 | mod->ftrace_callsites + mod->num_ftrace_callsites); | |
8c189ea6 | 6403 | } |
aba4b5c2 SRV |
6404 | |
6405 | static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map, | |
6406 | struct dyn_ftrace *rec) | |
6407 | { | |
6408 | struct ftrace_mod_func *mod_func; | |
6409 | unsigned long symsize; | |
6410 | unsigned long offset; | |
6411 | char str[KSYM_SYMBOL_LEN]; | |
6412 | char *modname; | |
6413 | const char *ret; | |
6414 | ||
6415 | ret = kallsyms_lookup(rec->ip, &symsize, &offset, &modname, str); | |
6416 | if (!ret) | |
6417 | return; | |
6418 | ||
6419 | mod_func = kmalloc(sizeof(*mod_func), GFP_KERNEL); | |
6420 | if (!mod_func) | |
6421 | return; | |
6422 | ||
6423 | mod_func->name = kstrdup(str, GFP_KERNEL); | |
6424 | if (!mod_func->name) { | |
6425 | kfree(mod_func); | |
6426 | return; | |
6427 | } | |
6428 | ||
6429 | mod_func->ip = rec->ip - offset; | |
6430 | mod_func->size = symsize; | |
6431 | ||
6171a031 SRV |
6432 | mod_map->num_funcs++; |
6433 | ||
aba4b5c2 SRV |
6434 | list_add_rcu(&mod_func->list, &mod_map->funcs); |
6435 | } | |
6436 | ||
aba4b5c2 SRV |
6437 | static struct ftrace_mod_map * |
6438 | allocate_ftrace_mod_map(struct module *mod, | |
6439 | unsigned long start, unsigned long end) | |
6440 | { | |
6441 | struct ftrace_mod_map *mod_map; | |
6442 | ||
6443 | mod_map = kmalloc(sizeof(*mod_map), GFP_KERNEL); | |
6444 | if (!mod_map) | |
6445 | return NULL; | |
6446 | ||
6447 | mod_map->mod = mod; | |
6448 | mod_map->start_addr = start; | |
6449 | mod_map->end_addr = end; | |
6171a031 | 6450 | mod_map->num_funcs = 0; |
aba4b5c2 SRV |
6451 | |
6452 | INIT_LIST_HEAD_RCU(&mod_map->funcs); | |
6453 | ||
6454 | list_add_rcu(&mod_map->list, &ftrace_mod_maps); | |
6455 | ||
6456 | return mod_map; | |
6457 | } | |
6458 | ||
6459 | static const char * | |
6460 | ftrace_func_address_lookup(struct ftrace_mod_map *mod_map, | |
6461 | unsigned long addr, unsigned long *size, | |
6462 | unsigned long *off, char *sym) | |
6463 | { | |
6464 | struct ftrace_mod_func *found_func = NULL; | |
6465 | struct ftrace_mod_func *mod_func; | |
6466 | ||
6467 | list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) { | |
6468 | if (addr >= mod_func->ip && | |
6469 | addr < mod_func->ip + mod_func->size) { | |
6470 | found_func = mod_func; | |
6471 | break; | |
6472 | } | |
6473 | } | |
6474 | ||
6475 | if (found_func) { | |
6476 | if (size) | |
6477 | *size = found_func->size; | |
6478 | if (off) | |
6479 | *off = addr - found_func->ip; | |
6480 | if (sym) | |
6481 | strlcpy(sym, found_func->name, KSYM_NAME_LEN); | |
6482 | ||
6483 | return found_func->name; | |
6484 | } | |
6485 | ||
6486 | return NULL; | |
6487 | } | |
6488 | ||
6489 | const char * | |
6490 | ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, | |
6491 | unsigned long *off, char **modname, char *sym) | |
6492 | { | |
6493 | struct ftrace_mod_map *mod_map; | |
6494 | const char *ret = NULL; | |
6495 | ||
74401729 | 6496 | /* mod_map is freed via call_rcu() */ |
aba4b5c2 SRV |
6497 | preempt_disable(); |
6498 | list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) { | |
6499 | ret = ftrace_func_address_lookup(mod_map, addr, size, off, sym); | |
6500 | if (ret) { | |
6501 | if (modname) | |
6502 | *modname = mod_map->mod->name; | |
6503 | break; | |
6504 | } | |
6505 | } | |
6506 | preempt_enable(); | |
6507 | ||
6508 | return ret; | |
6509 | } | |
6510 | ||
6171a031 SRV |
6511 | int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, |
6512 | char *type, char *name, | |
6513 | char *module_name, int *exported) | |
6514 | { | |
6515 | struct ftrace_mod_map *mod_map; | |
6516 | struct ftrace_mod_func *mod_func; | |
6517 | ||
6518 | preempt_disable(); | |
6519 | list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) { | |
6520 | ||
6521 | if (symnum >= mod_map->num_funcs) { | |
6522 | symnum -= mod_map->num_funcs; | |
6523 | continue; | |
6524 | } | |
6525 | ||
6526 | list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) { | |
6527 | if (symnum > 1) { | |
6528 | symnum--; | |
6529 | continue; | |
6530 | } | |
6531 | ||
6532 | *value = mod_func->ip; | |
6533 | *type = 'T'; | |
6534 | strlcpy(name, mod_func->name, KSYM_NAME_LEN); | |
6535 | strlcpy(module_name, mod_map->mod->name, MODULE_NAME_LEN); | |
6536 | *exported = 1; | |
6537 | preempt_enable(); | |
6538 | return 0; | |
6539 | } | |
6540 | WARN_ON(1); | |
6541 | break; | |
6542 | } | |
6543 | preempt_enable(); | |
6544 | return -ERANGE; | |
6545 | } | |
6546 | ||
aba4b5c2 SRV |
6547 | #else |
6548 | static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map, | |
6549 | struct dyn_ftrace *rec) { } | |
6550 | static inline struct ftrace_mod_map * | |
6551 | allocate_ftrace_mod_map(struct module *mod, | |
6552 | unsigned long start, unsigned long end) | |
6553 | { | |
6554 | return NULL; | |
6555 | } | |
93eb677d SR |
6556 | #endif /* CONFIG_MODULES */ |
6557 | ||
8715b108 JF |
6558 | struct ftrace_init_func { |
6559 | struct list_head list; | |
6560 | unsigned long ip; | |
6561 | }; | |
6562 | ||
6563 | /* Clear any init ips from hashes */ | |
6564 | static void | |
6565 | clear_func_from_hash(struct ftrace_init_func *func, struct ftrace_hash *hash) | |
42c269c8 | 6566 | { |
8715b108 JF |
6567 | struct ftrace_func_entry *entry; |
6568 | ||
08468754 | 6569 | entry = ftrace_lookup_ip(hash, func->ip); |
8715b108 JF |
6570 | /* |
6571 | * Do not allow this rec to match again. | |
6572 | * Yeah, it may waste some memory, but will be removed | |
6573 | * if/when the hash is modified again. | |
6574 | */ | |
6575 | if (entry) | |
6576 | entry->ip = 0; | |
6577 | } | |
6578 | ||
6579 | static void | |
6580 | clear_func_from_hashes(struct ftrace_init_func *func) | |
6581 | { | |
6582 | struct trace_array *tr; | |
6583 | ||
6584 | mutex_lock(&trace_types_lock); | |
6585 | list_for_each_entry(tr, &ftrace_trace_arrays, list) { | |
6586 | if (!tr->ops || !tr->ops->func_hash) | |
6587 | continue; | |
6588 | mutex_lock(&tr->ops->func_hash->regex_lock); | |
6589 | clear_func_from_hash(func, tr->ops->func_hash->filter_hash); | |
6590 | clear_func_from_hash(func, tr->ops->func_hash->notrace_hash); | |
6591 | mutex_unlock(&tr->ops->func_hash->regex_lock); | |
6592 | } | |
6593 | mutex_unlock(&trace_types_lock); | |
6594 | } | |
6595 | ||
6596 | static void add_to_clear_hash_list(struct list_head *clear_list, | |
6597 | struct dyn_ftrace *rec) | |
6598 | { | |
6599 | struct ftrace_init_func *func; | |
6600 | ||
6601 | func = kmalloc(sizeof(*func), GFP_KERNEL); | |
6602 | if (!func) { | |
24589e3a | 6603 | MEM_FAIL(1, "alloc failure, ftrace filter could be stale\n"); |
8715b108 JF |
6604 | return; |
6605 | } | |
6606 | ||
6607 | func->ip = rec->ip; | |
6608 | list_add(&func->list, clear_list); | |
6609 | } | |
6610 | ||
aba4b5c2 | 6611 | void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr) |
42c269c8 | 6612 | { |
6cafbe15 SRV |
6613 | unsigned long start = (unsigned long)(start_ptr); |
6614 | unsigned long end = (unsigned long)(end_ptr); | |
42c269c8 SRV |
6615 | struct ftrace_page **last_pg = &ftrace_pages_start; |
6616 | struct ftrace_page *pg; | |
6617 | struct dyn_ftrace *rec; | |
6618 | struct dyn_ftrace key; | |
aba4b5c2 | 6619 | struct ftrace_mod_map *mod_map = NULL; |
8715b108 JF |
6620 | struct ftrace_init_func *func, *func_next; |
6621 | struct list_head clear_hash; | |
42c269c8 SRV |
6622 | int order; |
6623 | ||
8715b108 JF |
6624 | INIT_LIST_HEAD(&clear_hash); |
6625 | ||
42c269c8 SRV |
6626 | key.ip = start; |
6627 | key.flags = end; /* overload flags, as it is unsigned long */ | |
6628 | ||
6629 | mutex_lock(&ftrace_lock); | |
6630 | ||
aba4b5c2 SRV |
6631 | /* |
6632 | * If we are freeing module init memory, then check if | |
6633 | * any tracer is active. If so, we need to save a mapping of | |
6634 | * the module functions being freed with the address. | |
6635 | */ | |
6636 | if (mod && ftrace_ops_list != &ftrace_list_end) | |
6637 | mod_map = allocate_ftrace_mod_map(mod, start, end); | |
6638 | ||
42c269c8 SRV |
6639 | for (pg = ftrace_pages_start; pg; last_pg = &pg->next, pg = *last_pg) { |
6640 | if (end < pg->records[0].ip || | |
6641 | start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) | |
6642 | continue; | |
6643 | again: | |
6644 | rec = bsearch(&key, pg->records, pg->index, | |
6645 | sizeof(struct dyn_ftrace), | |
6646 | ftrace_cmp_recs); | |
6647 | if (!rec) | |
6648 | continue; | |
aba4b5c2 | 6649 | |
8715b108 JF |
6650 | /* rec will be cleared from hashes after ftrace_lock unlock */ |
6651 | add_to_clear_hash_list(&clear_hash, rec); | |
6652 | ||
aba4b5c2 SRV |
6653 | if (mod_map) |
6654 | save_ftrace_mod_rec(mod_map, rec); | |
6655 | ||
42c269c8 | 6656 | pg->index--; |
4ec78467 | 6657 | ftrace_update_tot_cnt--; |
42c269c8 SRV |
6658 | if (!pg->index) { |
6659 | *last_pg = pg->next; | |
6660 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); | |
6661 | free_pages((unsigned long)pg->records, order); | |
da537f0a SRV |
6662 | ftrace_number_of_pages -= 1 << order; |
6663 | ftrace_number_of_groups--; | |
42c269c8 SRV |
6664 | kfree(pg); |
6665 | pg = container_of(last_pg, struct ftrace_page, next); | |
6666 | if (!(*last_pg)) | |
6667 | ftrace_pages = pg; | |
6668 | continue; | |
6669 | } | |
6670 | memmove(rec, rec + 1, | |
6671 | (pg->index - (rec - pg->records)) * sizeof(*rec)); | |
6672 | /* More than one function may be in this block */ | |
6673 | goto again; | |
6674 | } | |
6675 | mutex_unlock(&ftrace_lock); | |
8715b108 JF |
6676 | |
6677 | list_for_each_entry_safe(func, func_next, &clear_hash, list) { | |
6678 | clear_func_from_hashes(func); | |
6679 | kfree(func); | |
6680 | } | |
42c269c8 SRV |
6681 | } |
6682 | ||
6cafbe15 SRV |
6683 | void __init ftrace_free_init_mem(void) |
6684 | { | |
6685 | void *start = (void *)(&__init_begin); | |
6686 | void *end = (void *)(&__init_end); | |
6687 | ||
aba4b5c2 | 6688 | ftrace_free_mem(NULL, start, end); |
42c269c8 SRV |
6689 | } |
6690 | ||
68bf21aa SR |
6691 | void __init ftrace_init(void) |
6692 | { | |
1dc43cf0 JS |
6693 | extern unsigned long __start_mcount_loc[]; |
6694 | extern unsigned long __stop_mcount_loc[]; | |
3a36cb11 | 6695 | unsigned long count, flags; |
68bf21aa SR |
6696 | int ret; |
6697 | ||
68bf21aa | 6698 | local_irq_save(flags); |
3a36cb11 | 6699 | ret = ftrace_dyn_arch_init(); |
68bf21aa | 6700 | local_irq_restore(flags); |
af64a7cb | 6701 | if (ret) |
68bf21aa SR |
6702 | goto failed; |
6703 | ||
6704 | count = __stop_mcount_loc - __start_mcount_loc; | |
c867ccd8 JS |
6705 | if (!count) { |
6706 | pr_info("ftrace: No functions to be traced?\n"); | |
68bf21aa | 6707 | goto failed; |
c867ccd8 JS |
6708 | } |
6709 | ||
6710 | pr_info("ftrace: allocating %ld entries in %ld pages\n", | |
6711 | count, count / ENTRIES_PER_PAGE + 1); | |
68bf21aa SR |
6712 | |
6713 | last_ftrace_enabled = ftrace_enabled = 1; | |
6714 | ||
5cb084bb | 6715 | ret = ftrace_process_locs(NULL, |
31e88909 | 6716 | __start_mcount_loc, |
68bf21aa SR |
6717 | __stop_mcount_loc); |
6718 | ||
da537f0a SRV |
6719 | pr_info("ftrace: allocated %ld pages with %ld groups\n", |
6720 | ftrace_number_of_pages, ftrace_number_of_groups); | |
6721 | ||
2af15d6a SR |
6722 | set_ftrace_early_filters(); |
6723 | ||
68bf21aa SR |
6724 | return; |
6725 | failed: | |
6726 | ftrace_disabled = 1; | |
6727 | } | |
68bf21aa | 6728 | |
f3bea491 SRRH |
6729 | /* Do nothing if arch does not support this */ |
6730 | void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops) | |
6731 | { | |
6732 | } | |
6733 | ||
6734 | static void ftrace_update_trampoline(struct ftrace_ops *ops) | |
6735 | { | |
f3bea491 SRRH |
6736 | arch_ftrace_update_trampoline(ops); |
6737 | } | |
6738 | ||
04ec7bb6 SRV |
6739 | void ftrace_init_trace_array(struct trace_array *tr) |
6740 | { | |
6741 | INIT_LIST_HEAD(&tr->func_probes); | |
673feb9d SRV |
6742 | INIT_LIST_HEAD(&tr->mod_trace); |
6743 | INIT_LIST_HEAD(&tr->mod_notrace); | |
04ec7bb6 | 6744 | } |
3d083395 | 6745 | #else |
0b6e4d56 | 6746 | |
3306fc4a | 6747 | struct ftrace_ops global_ops = { |
bd69c30b | 6748 | .func = ftrace_stub, |
e3eea140 SRRH |
6749 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | |
6750 | FTRACE_OPS_FL_INITIALIZED | | |
6751 | FTRACE_OPS_FL_PID, | |
bd69c30b SR |
6752 | }; |
6753 | ||
0b6e4d56 FW |
6754 | static int __init ftrace_nodyn_init(void) |
6755 | { | |
6756 | ftrace_enabled = 1; | |
6757 | return 0; | |
6758 | } | |
6f415672 | 6759 | core_initcall(ftrace_nodyn_init); |
0b6e4d56 | 6760 | |
8434dc93 | 6761 | static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; } |
df4fc315 | 6762 | static inline void ftrace_startup_enable(int command) { } |
e1effa01 | 6763 | static inline void ftrace_startup_all(int command) { } |
8a56d776 | 6764 | |
c7aafc54 IM |
6765 | # define ftrace_startup_sysctl() do { } while (0) |
6766 | # define ftrace_shutdown_sysctl() do { } while (0) | |
b848914c | 6767 | |
f3bea491 SRRH |
6768 | static void ftrace_update_trampoline(struct ftrace_ops *ops) |
6769 | { | |
6770 | } | |
6771 | ||
3d083395 SR |
6772 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
6773 | ||
4104d326 SRRH |
6774 | __init void ftrace_init_global_array_ops(struct trace_array *tr) |
6775 | { | |
6776 | tr->ops = &global_ops; | |
6777 | tr->ops->private = tr; | |
04ec7bb6 | 6778 | ftrace_init_trace_array(tr); |
4104d326 SRRH |
6779 | } |
6780 | ||
6781 | void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func) | |
6782 | { | |
6783 | /* If we filter on pids, update to use the pid function */ | |
6784 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL) { | |
6785 | if (WARN_ON(tr->ops->func != ftrace_stub)) | |
6786 | printk("ftrace ops had %pS for function\n", | |
6787 | tr->ops->func); | |
4104d326 SRRH |
6788 | } |
6789 | tr->ops->func = func; | |
6790 | tr->ops->private = tr; | |
6791 | } | |
6792 | ||
6793 | void ftrace_reset_array_ops(struct trace_array *tr) | |
6794 | { | |
6795 | tr->ops->func = ftrace_stub; | |
6796 | } | |
6797 | ||
fabe38ab | 6798 | static nokprobe_inline void |
2f5f6ad9 | 6799 | __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 6800 | struct ftrace_ops *ignored, struct pt_regs *regs) |
b848914c | 6801 | { |
cdbe61bf | 6802 | struct ftrace_ops *op; |
edc15caf | 6803 | int bit; |
b848914c | 6804 | |
edc15caf SR |
6805 | bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX); |
6806 | if (bit < 0) | |
6807 | return; | |
b1cff0ad | 6808 | |
cdbe61bf SR |
6809 | /* |
6810 | * Some of the ops may be dynamically allocated, | |
74401729 | 6811 | * they must be freed after a synchronize_rcu(). |
cdbe61bf SR |
6812 | */ |
6813 | preempt_disable_notrace(); | |
ba27f2bc | 6814 | |
0a016409 | 6815 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
2fa717a0 SRV |
6816 | /* Stub functions don't need to be called nor tested */ |
6817 | if (op->flags & FTRACE_OPS_FL_STUB) | |
6818 | continue; | |
ba27f2bc SRRH |
6819 | /* |
6820 | * Check the following for each ops before calling their func: | |
6821 | * if RCU flag is set, then rcu_is_watching() must be true | |
6822 | * if PER_CPU is set, then ftrace_function_local_disable() | |
6823 | * must be false | |
6824 | * Otherwise test if the ip matches the ops filter | |
6825 | * | |
6826 | * If any of the above fails then the op->func() is not executed. | |
6827 | */ | |
6828 | if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) && | |
ba27f2bc | 6829 | ftrace_ops_test(op, ip, regs)) { |
1d48d596 SRRH |
6830 | if (FTRACE_WARN_ON(!op->func)) { |
6831 | pr_warn("op=%p %pS\n", op, op); | |
4104d326 SRRH |
6832 | goto out; |
6833 | } | |
a1e2e31d | 6834 | op->func(ip, parent_ip, op, regs); |
4104d326 | 6835 | } |
0a016409 | 6836 | } while_for_each_ftrace_op(op); |
4104d326 | 6837 | out: |
cdbe61bf | 6838 | preempt_enable_notrace(); |
edc15caf | 6839 | trace_clear_recursion(bit); |
b848914c SR |
6840 | } |
6841 | ||
2f5f6ad9 SR |
6842 | /* |
6843 | * Some archs only support passing ip and parent_ip. Even though | |
6844 | * the list function ignores the op parameter, we do not want any | |
6845 | * C side effects, where a function is called without the caller | |
6846 | * sending a third parameter. | |
a1e2e31d SR |
6847 | * Archs are to support both the regs and ftrace_ops at the same time. |
6848 | * If they support ftrace_ops, it is assumed they support regs. | |
6849 | * If call backs want to use regs, they must either check for regs | |
06aeaaea MH |
6850 | * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS. |
6851 | * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved. | |
a1e2e31d | 6852 | * An architecture can pass partial regs with ftrace_ops and still |
b8ec330a | 6853 | * set the ARCH_SUPPORTS_FTRACE_OPS. |
2f5f6ad9 SR |
6854 | */ |
6855 | #if ARCH_SUPPORTS_FTRACE_OPS | |
6856 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 6857 | struct ftrace_ops *op, struct pt_regs *regs) |
2f5f6ad9 | 6858 | { |
a1e2e31d | 6859 | __ftrace_ops_list_func(ip, parent_ip, NULL, regs); |
2f5f6ad9 | 6860 | } |
fabe38ab | 6861 | NOKPROBE_SYMBOL(ftrace_ops_list_func); |
2f5f6ad9 SR |
6862 | #else |
6863 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip) | |
6864 | { | |
a1e2e31d | 6865 | __ftrace_ops_list_func(ip, parent_ip, NULL, NULL); |
2f5f6ad9 | 6866 | } |
fabe38ab | 6867 | NOKPROBE_SYMBOL(ftrace_ops_no_ops); |
2f5f6ad9 SR |
6868 | #endif |
6869 | ||
f1ff6348 SRRH |
6870 | /* |
6871 | * If there's only one function registered but it does not support | |
c68c0fa2 SRRH |
6872 | * recursion, needs RCU protection and/or requires per cpu handling, then |
6873 | * this function will be called by the mcount trampoline. | |
f1ff6348 | 6874 | */ |
c68c0fa2 | 6875 | static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip, |
f1ff6348 SRRH |
6876 | struct ftrace_ops *op, struct pt_regs *regs) |
6877 | { | |
6878 | int bit; | |
6879 | ||
c68c0fa2 SRRH |
6880 | if ((op->flags & FTRACE_OPS_FL_RCU) && !rcu_is_watching()) |
6881 | return; | |
6882 | ||
f1ff6348 SRRH |
6883 | bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX); |
6884 | if (bit < 0) | |
6885 | return; | |
6886 | ||
c68c0fa2 | 6887 | preempt_disable_notrace(); |
f1ff6348 | 6888 | |
b3a88803 | 6889 | op->func(ip, parent_ip, op, regs); |
c68c0fa2 SRRH |
6890 | |
6891 | preempt_enable_notrace(); | |
f1ff6348 SRRH |
6892 | trace_clear_recursion(bit); |
6893 | } | |
fabe38ab | 6894 | NOKPROBE_SYMBOL(ftrace_ops_assist_func); |
f1ff6348 | 6895 | |
87354059 SRRH |
6896 | /** |
6897 | * ftrace_ops_get_func - get the function a trampoline should call | |
6898 | * @ops: the ops to get the function for | |
6899 | * | |
6900 | * Normally the mcount trampoline will call the ops->func, but there | |
6901 | * are times that it should not. For example, if the ops does not | |
6902 | * have its own recursion protection, then it should call the | |
3a150df9 | 6903 | * ftrace_ops_assist_func() instead. |
87354059 SRRH |
6904 | * |
6905 | * Returns the function that the trampoline should call for @ops. | |
6906 | */ | |
6907 | ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops) | |
6908 | { | |
87354059 | 6909 | /* |
c68c0fa2 SRRH |
6910 | * If the function does not handle recursion, needs to be RCU safe, |
6911 | * or does per cpu logic, then we need to call the assist handler. | |
87354059 | 6912 | */ |
c68c0fa2 | 6913 | if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE) || |
b3a88803 | 6914 | ops->flags & FTRACE_OPS_FL_RCU) |
c68c0fa2 | 6915 | return ftrace_ops_assist_func; |
87354059 SRRH |
6916 | |
6917 | return ops->func; | |
6918 | } | |
6919 | ||
345ddcc8 SRRH |
6920 | static void |
6921 | ftrace_filter_pid_sched_switch_probe(void *data, bool preempt, | |
6922 | struct task_struct *prev, struct task_struct *next) | |
978f3a45 | 6923 | { |
345ddcc8 SRRH |
6924 | struct trace_array *tr = data; |
6925 | struct trace_pid_list *pid_list; | |
978f3a45 | 6926 | |
345ddcc8 | 6927 | pid_list = rcu_dereference_sched(tr->function_pids); |
e32d8956 | 6928 | |
1c5eb448 | 6929 | this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, |
345ddcc8 | 6930 | trace_ignore_this_task(pid_list, next)); |
978f3a45 SR |
6931 | } |
6932 | ||
1e10486f NK |
6933 | static void |
6934 | ftrace_pid_follow_sched_process_fork(void *data, | |
6935 | struct task_struct *self, | |
6936 | struct task_struct *task) | |
6937 | { | |
6938 | struct trace_pid_list *pid_list; | |
6939 | struct trace_array *tr = data; | |
6940 | ||
6941 | pid_list = rcu_dereference_sched(tr->function_pids); | |
6942 | trace_filter_add_remove_task(pid_list, self, task); | |
6943 | } | |
6944 | ||
6945 | static void | |
6946 | ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task) | |
6947 | { | |
6948 | struct trace_pid_list *pid_list; | |
6949 | struct trace_array *tr = data; | |
6950 | ||
6951 | pid_list = rcu_dereference_sched(tr->function_pids); | |
6952 | trace_filter_add_remove_task(pid_list, NULL, task); | |
6953 | } | |
6954 | ||
6955 | void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) | |
6956 | { | |
6957 | if (enable) { | |
6958 | register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, | |
6959 | tr); | |
6960 | register_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit, | |
6961 | tr); | |
6962 | } else { | |
6963 | unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, | |
6964 | tr); | |
6965 | unregister_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit, | |
6966 | tr); | |
6967 | } | |
6968 | } | |
6969 | ||
345ddcc8 | 6970 | static void clear_ftrace_pids(struct trace_array *tr) |
e32d8956 | 6971 | { |
345ddcc8 SRRH |
6972 | struct trace_pid_list *pid_list; |
6973 | int cpu; | |
e32d8956 | 6974 | |
345ddcc8 SRRH |
6975 | pid_list = rcu_dereference_protected(tr->function_pids, |
6976 | lockdep_is_held(&ftrace_lock)); | |
6977 | if (!pid_list) | |
6978 | return; | |
229c4ef8 | 6979 | |
345ddcc8 | 6980 | unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr); |
e32d8956 | 6981 | |
345ddcc8 | 6982 | for_each_possible_cpu(cpu) |
1c5eb448 | 6983 | per_cpu_ptr(tr->array_buffer.data, cpu)->ftrace_ignore_pid = false; |
978f3a45 | 6984 | |
345ddcc8 | 6985 | rcu_assign_pointer(tr->function_pids, NULL); |
978f3a45 | 6986 | |
345ddcc8 | 6987 | /* Wait till all users are no longer using pid filtering */ |
74401729 | 6988 | synchronize_rcu(); |
e32d8956 | 6989 | |
345ddcc8 | 6990 | trace_free_pid_list(pid_list); |
e32d8956 SR |
6991 | } |
6992 | ||
d879d0b8 NK |
6993 | void ftrace_clear_pids(struct trace_array *tr) |
6994 | { | |
6995 | mutex_lock(&ftrace_lock); | |
6996 | ||
6997 | clear_ftrace_pids(tr); | |
6998 | ||
6999 | mutex_unlock(&ftrace_lock); | |
7000 | } | |
7001 | ||
345ddcc8 | 7002 | static void ftrace_pid_reset(struct trace_array *tr) |
df4fc315 | 7003 | { |
756d17ee | 7004 | mutex_lock(&ftrace_lock); |
345ddcc8 | 7005 | clear_ftrace_pids(tr); |
978f3a45 | 7006 | |
756d17ee | 7007 | ftrace_update_pid_func(); |
e1effa01 | 7008 | ftrace_startup_all(0); |
756d17ee | 7009 | |
7010 | mutex_unlock(&ftrace_lock); | |
756d17ee | 7011 | } |
7012 | ||
345ddcc8 SRRH |
7013 | /* Greater than any max PID */ |
7014 | #define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1) | |
df4fc315 | 7015 | |
756d17ee | 7016 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
345ddcc8 | 7017 | __acquires(RCU) |
756d17ee | 7018 | { |
345ddcc8 SRRH |
7019 | struct trace_pid_list *pid_list; |
7020 | struct trace_array *tr = m->private; | |
7021 | ||
756d17ee | 7022 | mutex_lock(&ftrace_lock); |
345ddcc8 SRRH |
7023 | rcu_read_lock_sched(); |
7024 | ||
7025 | pid_list = rcu_dereference_sched(tr->function_pids); | |
756d17ee | 7026 | |
345ddcc8 SRRH |
7027 | if (!pid_list) |
7028 | return !(*pos) ? FTRACE_NO_PIDS : NULL; | |
756d17ee | 7029 | |
345ddcc8 | 7030 | return trace_pid_start(pid_list, pos); |
756d17ee | 7031 | } |
7032 | ||
7033 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
7034 | { | |
345ddcc8 SRRH |
7035 | struct trace_array *tr = m->private; |
7036 | struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids); | |
7037 | ||
e4075e8b VA |
7038 | if (v == FTRACE_NO_PIDS) { |
7039 | (*pos)++; | |
756d17ee | 7040 | return NULL; |
e4075e8b | 7041 | } |
345ddcc8 | 7042 | return trace_pid_next(pid_list, v, pos); |
756d17ee | 7043 | } |
7044 | ||
7045 | static void fpid_stop(struct seq_file *m, void *p) | |
345ddcc8 | 7046 | __releases(RCU) |
756d17ee | 7047 | { |
345ddcc8 | 7048 | rcu_read_unlock_sched(); |
756d17ee | 7049 | mutex_unlock(&ftrace_lock); |
7050 | } | |
7051 | ||
7052 | static int fpid_show(struct seq_file *m, void *v) | |
7053 | { | |
345ddcc8 | 7054 | if (v == FTRACE_NO_PIDS) { |
fa6f0cc7 | 7055 | seq_puts(m, "no pid\n"); |
756d17ee | 7056 | return 0; |
7057 | } | |
7058 | ||
345ddcc8 | 7059 | return trace_pid_show(m, v); |
756d17ee | 7060 | } |
7061 | ||
7062 | static const struct seq_operations ftrace_pid_sops = { | |
7063 | .start = fpid_start, | |
7064 | .next = fpid_next, | |
7065 | .stop = fpid_stop, | |
7066 | .show = fpid_show, | |
7067 | }; | |
7068 | ||
7069 | static int | |
7070 | ftrace_pid_open(struct inode *inode, struct file *file) | |
7071 | { | |
345ddcc8 SRRH |
7072 | struct trace_array *tr = inode->i_private; |
7073 | struct seq_file *m; | |
756d17ee | 7074 | int ret = 0; |
7075 | ||
8530dec6 SRV |
7076 | ret = tracing_check_open_get_tr(tr); |
7077 | if (ret) | |
7078 | return ret; | |
345ddcc8 | 7079 | |
756d17ee | 7080 | if ((file->f_mode & FMODE_WRITE) && |
7081 | (file->f_flags & O_TRUNC)) | |
345ddcc8 | 7082 | ftrace_pid_reset(tr); |
756d17ee | 7083 | |
345ddcc8 SRRH |
7084 | ret = seq_open(file, &ftrace_pid_sops); |
7085 | if (ret < 0) { | |
7086 | trace_array_put(tr); | |
7087 | } else { | |
7088 | m = file->private_data; | |
7089 | /* copy tr over to seq ops */ | |
7090 | m->private = tr; | |
7091 | } | |
756d17ee | 7092 | |
7093 | return ret; | |
7094 | } | |
7095 | ||
345ddcc8 SRRH |
7096 | static void ignore_task_cpu(void *data) |
7097 | { | |
7098 | struct trace_array *tr = data; | |
7099 | struct trace_pid_list *pid_list; | |
7100 | ||
7101 | /* | |
7102 | * This function is called by on_each_cpu() while the | |
7103 | * event_mutex is held. | |
7104 | */ | |
7105 | pid_list = rcu_dereference_protected(tr->function_pids, | |
7106 | mutex_is_locked(&ftrace_lock)); | |
7107 | ||
1c5eb448 | 7108 | this_cpu_write(tr->array_buffer.data->ftrace_ignore_pid, |
345ddcc8 SRRH |
7109 | trace_ignore_this_task(pid_list, current)); |
7110 | } | |
7111 | ||
df4fc315 SR |
7112 | static ssize_t |
7113 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
7114 | size_t cnt, loff_t *ppos) | |
7115 | { | |
345ddcc8 SRRH |
7116 | struct seq_file *m = filp->private_data; |
7117 | struct trace_array *tr = m->private; | |
7118 | struct trace_pid_list *filtered_pids = NULL; | |
7119 | struct trace_pid_list *pid_list; | |
7120 | ssize_t ret; | |
df4fc315 | 7121 | |
345ddcc8 SRRH |
7122 | if (!cnt) |
7123 | return 0; | |
7124 | ||
7125 | mutex_lock(&ftrace_lock); | |
7126 | ||
7127 | filtered_pids = rcu_dereference_protected(tr->function_pids, | |
7128 | lockdep_is_held(&ftrace_lock)); | |
7129 | ||
7130 | ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt); | |
7131 | if (ret < 0) | |
7132 | goto out; | |
df4fc315 | 7133 | |
345ddcc8 | 7134 | rcu_assign_pointer(tr->function_pids, pid_list); |
df4fc315 | 7135 | |
345ddcc8 | 7136 | if (filtered_pids) { |
74401729 | 7137 | synchronize_rcu(); |
345ddcc8 SRRH |
7138 | trace_free_pid_list(filtered_pids); |
7139 | } else if (pid_list) { | |
7140 | /* Register a probe to set whether to ignore the tracing of a task */ | |
7141 | register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr); | |
7142 | } | |
df4fc315 | 7143 | |
756d17ee | 7144 | /* |
345ddcc8 SRRH |
7145 | * Ignoring of pids is done at task switch. But we have to |
7146 | * check for those tasks that are currently running. | |
7147 | * Always do this in case a pid was appended or removed. | |
756d17ee | 7148 | */ |
345ddcc8 | 7149 | on_each_cpu(ignore_task_cpu, tr, 1); |
756d17ee | 7150 | |
345ddcc8 SRRH |
7151 | ftrace_update_pid_func(); |
7152 | ftrace_startup_all(0); | |
7153 | out: | |
7154 | mutex_unlock(&ftrace_lock); | |
df4fc315 | 7155 | |
345ddcc8 SRRH |
7156 | if (ret > 0) |
7157 | *ppos += ret; | |
df4fc315 | 7158 | |
345ddcc8 | 7159 | return ret; |
756d17ee | 7160 | } |
df4fc315 | 7161 | |
756d17ee | 7162 | static int |
7163 | ftrace_pid_release(struct inode *inode, struct file *file) | |
7164 | { | |
345ddcc8 | 7165 | struct trace_array *tr = inode->i_private; |
df4fc315 | 7166 | |
345ddcc8 SRRH |
7167 | trace_array_put(tr); |
7168 | ||
7169 | return seq_release(inode, file); | |
df4fc315 SR |
7170 | } |
7171 | ||
5e2336a0 | 7172 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 7173 | .open = ftrace_pid_open, |
7174 | .write = ftrace_pid_write, | |
7175 | .read = seq_read, | |
098c879e | 7176 | .llseek = tracing_lseek, |
756d17ee | 7177 | .release = ftrace_pid_release, |
df4fc315 SR |
7178 | }; |
7179 | ||
345ddcc8 | 7180 | void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer) |
df4fc315 | 7181 | { |
5452af66 | 7182 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
345ddcc8 | 7183 | tr, &ftrace_pid_fops); |
df4fc315 | 7184 | } |
df4fc315 | 7185 | |
501c2375 SRRH |
7186 | void __init ftrace_init_tracefs_toplevel(struct trace_array *tr, |
7187 | struct dentry *d_tracer) | |
7188 | { | |
7189 | /* Only the top level directory has the dyn_tracefs and profile */ | |
7190 | WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL)); | |
7191 | ||
7192 | ftrace_init_dyn_tracefs(d_tracer); | |
7193 | ftrace_profile_tracefs(d_tracer); | |
7194 | } | |
7195 | ||
a2bb6a3d | 7196 | /** |
81adbdc0 | 7197 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
7198 | * |
7199 | * This function should be used by panic code. It stops ftrace | |
7200 | * but in a not so nice way. If you need to simply kill ftrace | |
7201 | * from a non-atomic section, use ftrace_kill. | |
7202 | */ | |
81adbdc0 | 7203 | void ftrace_kill(void) |
a2bb6a3d SR |
7204 | { |
7205 | ftrace_disabled = 1; | |
7206 | ftrace_enabled = 0; | |
5ccba64a | 7207 | ftrace_trace_function = ftrace_stub; |
a2bb6a3d SR |
7208 | } |
7209 | ||
e0a413f6 SR |
7210 | /** |
7211 | * Test if ftrace is dead or not. | |
7212 | */ | |
7213 | int ftrace_is_dead(void) | |
7214 | { | |
7215 | return ftrace_disabled; | |
7216 | } | |
7217 | ||
16444a8a | 7218 | /** |
3d083395 SR |
7219 | * register_ftrace_function - register a function for profiling |
7220 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 7221 | * |
3d083395 SR |
7222 | * Register a function to be called by all functions in the |
7223 | * kernel. | |
7224 | * | |
7225 | * Note: @ops->func and all the functions it calls must be labeled | |
7226 | * with "notrace", otherwise it will go into a | |
7227 | * recursive loop. | |
16444a8a | 7228 | */ |
3d083395 | 7229 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 7230 | { |
45a4a237 | 7231 | int ret = -1; |
4eebcc81 | 7232 | |
f04f24fb MH |
7233 | ftrace_ops_init(ops); |
7234 | ||
e6ea44e9 | 7235 | mutex_lock(&ftrace_lock); |
e7d3737e | 7236 | |
8a56d776 | 7237 | ret = ftrace_startup(ops, 0); |
b848914c | 7238 | |
e6ea44e9 | 7239 | mutex_unlock(&ftrace_lock); |
8d240dd8 | 7240 | |
b0fc494f | 7241 | return ret; |
3d083395 | 7242 | } |
cdbe61bf | 7243 | EXPORT_SYMBOL_GPL(register_ftrace_function); |
3d083395 SR |
7244 | |
7245 | /** | |
32632920 | 7246 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
7247 | * @ops - ops structure that holds the function to unregister |
7248 | * | |
7249 | * Unregister a function that was added to be called by ftrace profiling. | |
7250 | */ | |
7251 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
7252 | { | |
7253 | int ret; | |
7254 | ||
e6ea44e9 | 7255 | mutex_lock(&ftrace_lock); |
8a56d776 | 7256 | ret = ftrace_shutdown(ops, 0); |
e6ea44e9 | 7257 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
7258 | |
7259 | return ret; | |
7260 | } | |
cdbe61bf | 7261 | EXPORT_SYMBOL_GPL(unregister_ftrace_function); |
b0fc494f | 7262 | |
7162431d MB |
7263 | static bool is_permanent_ops_registered(void) |
7264 | { | |
7265 | struct ftrace_ops *op; | |
7266 | ||
7267 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
7268 | if (op->flags & FTRACE_OPS_FL_PERMANENT) | |
7269 | return true; | |
7270 | } while_for_each_ftrace_op(op); | |
7271 | ||
7272 | return false; | |
7273 | } | |
7274 | ||
e309b41d | 7275 | int |
b0fc494f | 7276 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
8d65af78 | 7277 | void __user *buffer, size_t *lenp, |
b0fc494f SR |
7278 | loff_t *ppos) |
7279 | { | |
45a4a237 | 7280 | int ret = -ENODEV; |
4eebcc81 | 7281 | |
e6ea44e9 | 7282 | mutex_lock(&ftrace_lock); |
b0fc494f | 7283 | |
45a4a237 SR |
7284 | if (unlikely(ftrace_disabled)) |
7285 | goto out; | |
7286 | ||
7287 | ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
b0fc494f | 7288 | |
a32c7765 | 7289 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
7290 | goto out; |
7291 | ||
b0fc494f SR |
7292 | if (ftrace_enabled) { |
7293 | ||
b0fc494f | 7294 | /* we are starting ftrace again */ |
f86f4180 CZ |
7295 | if (rcu_dereference_protected(ftrace_ops_list, |
7296 | lockdep_is_held(&ftrace_lock)) != &ftrace_list_end) | |
5000c418 | 7297 | update_ftrace_function(); |
b0fc494f | 7298 | |
524a3868 SRRH |
7299 | ftrace_startup_sysctl(); |
7300 | ||
b0fc494f | 7301 | } else { |
7162431d MB |
7302 | if (is_permanent_ops_registered()) { |
7303 | ftrace_enabled = true; | |
7304 | ret = -EBUSY; | |
7305 | goto out; | |
7306 | } | |
7307 | ||
b0fc494f SR |
7308 | /* stopping ftrace calls (just send to ftrace_stub) */ |
7309 | ftrace_trace_function = ftrace_stub; | |
7310 | ||
7311 | ftrace_shutdown_sysctl(); | |
7312 | } | |
7313 | ||
7162431d | 7314 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f | 7315 | out: |
e6ea44e9 | 7316 | mutex_unlock(&ftrace_lock); |
3d083395 | 7317 | return ret; |
16444a8a | 7318 | } |