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Commit | Line | Data |
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16444a8a ACM |
1 | /* |
2 | * Infrastructure for profiling code inserted by 'gcc -pg'. | |
3 | * | |
4 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> | |
5 | * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com> | |
6 | * | |
7 | * Originally ported from the -rt patch by: | |
8 | * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com> | |
9 | * | |
10 | * Based on code in the latency_tracer, that is: | |
11 | * | |
12 | * Copyright (C) 2004-2006 Ingo Molnar | |
6d49e352 | 13 | * Copyright (C) 2004 Nadia Yvette Chambers |
16444a8a ACM |
14 | */ |
15 | ||
3d083395 SR |
16 | #include <linux/stop_machine.h> |
17 | #include <linux/clocksource.h> | |
18 | #include <linux/kallsyms.h> | |
5072c59f | 19 | #include <linux/seq_file.h> |
4a2b8dda | 20 | #include <linux/suspend.h> |
5072c59f | 21 | #include <linux/debugfs.h> |
3d083395 | 22 | #include <linux/hardirq.h> |
2d8b820b | 23 | #include <linux/kthread.h> |
5072c59f | 24 | #include <linux/uaccess.h> |
5855fead | 25 | #include <linux/bsearch.h> |
56d82e00 | 26 | #include <linux/module.h> |
2d8b820b | 27 | #include <linux/ftrace.h> |
b0fc494f | 28 | #include <linux/sysctl.h> |
5a0e3ad6 | 29 | #include <linux/slab.h> |
5072c59f | 30 | #include <linux/ctype.h> |
68950619 | 31 | #include <linux/sort.h> |
3d083395 | 32 | #include <linux/list.h> |
59df055f | 33 | #include <linux/hash.h> |
3f379b03 | 34 | #include <linux/rcupdate.h> |
3d083395 | 35 | |
ad8d75ff | 36 | #include <trace/events/sched.h> |
8aef2d28 | 37 | |
2af15d6a | 38 | #include <asm/setup.h> |
395a59d0 | 39 | |
0706f1c4 | 40 | #include "trace_output.h" |
bac429f0 | 41 | #include "trace_stat.h" |
16444a8a | 42 | |
6912896e | 43 | #define FTRACE_WARN_ON(cond) \ |
0778d9ad SR |
44 | ({ \ |
45 | int ___r = cond; \ | |
46 | if (WARN_ON(___r)) \ | |
6912896e | 47 | ftrace_kill(); \ |
0778d9ad SR |
48 | ___r; \ |
49 | }) | |
6912896e SR |
50 | |
51 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
0778d9ad SR |
52 | ({ \ |
53 | int ___r = cond; \ | |
54 | if (WARN_ON_ONCE(___r)) \ | |
6912896e | 55 | ftrace_kill(); \ |
0778d9ad SR |
56 | ___r; \ |
57 | }) | |
6912896e | 58 | |
8fc0c701 SR |
59 | /* hash bits for specific function selection */ |
60 | #define FTRACE_HASH_BITS 7 | |
61 | #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS) | |
33dc9b12 SR |
62 | #define FTRACE_HASH_DEFAULT_BITS 10 |
63 | #define FTRACE_HASH_MAX_BITS 12 | |
8fc0c701 | 64 | |
4104d326 | 65 | #define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_CONTROL) |
e248491a | 66 | |
f04f24fb MH |
67 | #ifdef CONFIG_DYNAMIC_FTRACE |
68 | #define INIT_REGEX_LOCK(opsname) \ | |
69 | .regex_lock = __MUTEX_INITIALIZER(opsname.regex_lock), | |
70 | #else | |
71 | #define INIT_REGEX_LOCK(opsname) | |
72 | #endif | |
73 | ||
2f5f6ad9 SR |
74 | static struct ftrace_ops ftrace_list_end __read_mostly = { |
75 | .func = ftrace_stub, | |
395b97a3 | 76 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB, |
2f5f6ad9 SR |
77 | }; |
78 | ||
4eebcc81 SR |
79 | /* ftrace_enabled is a method to turn ftrace on or off */ |
80 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 81 | static int last_ftrace_enabled; |
b0fc494f | 82 | |
2f5f6ad9 SR |
83 | /* Current function tracing op */ |
84 | struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end; | |
405e1d83 SRRH |
85 | /* What to set function_trace_op to */ |
86 | static struct ftrace_ops *set_function_trace_op; | |
60a7ecf4 | 87 | |
756d17ee | 88 | /* List for set_ftrace_pid's pids. */ |
89 | LIST_HEAD(ftrace_pids); | |
90 | struct ftrace_pid { | |
91 | struct list_head list; | |
92 | struct pid *pid; | |
93 | }; | |
94 | ||
4eebcc81 SR |
95 | /* |
96 | * ftrace_disabled is set when an anomaly is discovered. | |
97 | * ftrace_disabled is much stronger than ftrace_enabled. | |
98 | */ | |
99 | static int ftrace_disabled __read_mostly; | |
100 | ||
52baf119 | 101 | static DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 102 | |
e248491a | 103 | static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end; |
b848914c | 104 | static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end; |
16444a8a | 105 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
df4fc315 | 106 | ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; |
2b499381 | 107 | static struct ftrace_ops global_ops; |
e248491a | 108 | static struct ftrace_ops control_ops; |
16444a8a | 109 | |
2f5f6ad9 SR |
110 | #if ARCH_SUPPORTS_FTRACE_OPS |
111 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 112 | struct ftrace_ops *op, struct pt_regs *regs); |
2f5f6ad9 SR |
113 | #else |
114 | /* See comment below, where ftrace_ops_list_func is defined */ | |
115 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip); | |
116 | #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops) | |
117 | #endif | |
b848914c | 118 | |
0a016409 SR |
119 | /* |
120 | * Traverse the ftrace_global_list, invoking all entries. The reason that we | |
1bb539ca | 121 | * can use rcu_dereference_raw_notrace() is that elements removed from this list |
0a016409 | 122 | * are simply leaked, so there is no need to interact with a grace-period |
1bb539ca | 123 | * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle |
0a016409 SR |
124 | * concurrent insertions into the ftrace_global_list. |
125 | * | |
126 | * Silly Alpha and silly pointer-speculation compiler optimizations! | |
127 | */ | |
128 | #define do_for_each_ftrace_op(op, list) \ | |
1bb539ca | 129 | op = rcu_dereference_raw_notrace(list); \ |
0a016409 SR |
130 | do |
131 | ||
132 | /* | |
133 | * Optimized for just a single item in the list (as that is the normal case). | |
134 | */ | |
135 | #define while_for_each_ftrace_op(op) \ | |
1bb539ca | 136 | while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \ |
0a016409 SR |
137 | unlikely((op) != &ftrace_list_end)) |
138 | ||
f04f24fb MH |
139 | static inline void ftrace_ops_init(struct ftrace_ops *ops) |
140 | { | |
141 | #ifdef CONFIG_DYNAMIC_FTRACE | |
142 | if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) { | |
143 | mutex_init(&ops->regex_lock); | |
144 | ops->flags |= FTRACE_OPS_FL_INITIALIZED; | |
145 | } | |
146 | #endif | |
147 | } | |
148 | ||
ea701f11 SR |
149 | /** |
150 | * ftrace_nr_registered_ops - return number of ops registered | |
151 | * | |
152 | * Returns the number of ftrace_ops registered and tracing functions | |
153 | */ | |
154 | int ftrace_nr_registered_ops(void) | |
155 | { | |
156 | struct ftrace_ops *ops; | |
157 | int cnt = 0; | |
158 | ||
159 | mutex_lock(&ftrace_lock); | |
160 | ||
161 | for (ops = ftrace_ops_list; | |
162 | ops != &ftrace_list_end; ops = ops->next) | |
163 | cnt++; | |
164 | ||
165 | mutex_unlock(&ftrace_lock); | |
166 | ||
167 | return cnt; | |
168 | } | |
169 | ||
2f5f6ad9 | 170 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 171 | struct ftrace_ops *op, struct pt_regs *regs) |
df4fc315 | 172 | { |
0ef8cde5 | 173 | if (!test_tsk_trace_trace(current)) |
df4fc315 SR |
174 | return; |
175 | ||
a1e2e31d | 176 | ftrace_pid_function(ip, parent_ip, op, regs); |
df4fc315 SR |
177 | } |
178 | ||
179 | static void set_ftrace_pid_function(ftrace_func_t func) | |
180 | { | |
181 | /* do not set ftrace_pid_function to itself! */ | |
182 | if (func != ftrace_pid_func) | |
183 | ftrace_pid_function = func; | |
184 | } | |
185 | ||
16444a8a | 186 | /** |
3d083395 | 187 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 188 | * |
3d083395 SR |
189 | * This NULLs the ftrace function and in essence stops |
190 | * tracing. There may be lag | |
16444a8a | 191 | */ |
3d083395 | 192 | void clear_ftrace_function(void) |
16444a8a | 193 | { |
3d083395 | 194 | ftrace_trace_function = ftrace_stub; |
df4fc315 | 195 | ftrace_pid_function = ftrace_stub; |
3d083395 SR |
196 | } |
197 | ||
e248491a JO |
198 | static void control_ops_disable_all(struct ftrace_ops *ops) |
199 | { | |
200 | int cpu; | |
201 | ||
202 | for_each_possible_cpu(cpu) | |
203 | *per_cpu_ptr(ops->disabled, cpu) = 1; | |
204 | } | |
205 | ||
206 | static int control_ops_alloc(struct ftrace_ops *ops) | |
207 | { | |
208 | int __percpu *disabled; | |
209 | ||
210 | disabled = alloc_percpu(int); | |
211 | if (!disabled) | |
212 | return -ENOMEM; | |
213 | ||
214 | ops->disabled = disabled; | |
215 | control_ops_disable_all(ops); | |
216 | return 0; | |
217 | } | |
218 | ||
405e1d83 SRRH |
219 | static void ftrace_sync(struct work_struct *work) |
220 | { | |
221 | /* | |
222 | * This function is just a stub to implement a hard force | |
223 | * of synchronize_sched(). This requires synchronizing | |
224 | * tasks even in userspace and idle. | |
225 | * | |
226 | * Yes, function tracing is rude. | |
227 | */ | |
228 | } | |
229 | ||
230 | static void ftrace_sync_ipi(void *data) | |
231 | { | |
232 | /* Probably not needed, but do it anyway */ | |
233 | smp_rmb(); | |
234 | } | |
235 | ||
23a8e844 SRRH |
236 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
237 | static void update_function_graph_func(void); | |
238 | #else | |
239 | static inline void update_function_graph_func(void) { } | |
240 | #endif | |
241 | ||
2b499381 SR |
242 | static void update_ftrace_function(void) |
243 | { | |
244 | ftrace_func_t func; | |
245 | ||
cdbe61bf SR |
246 | /* |
247 | * If we are at the end of the list and this ops is | |
4740974a SR |
248 | * recursion safe and not dynamic and the arch supports passing ops, |
249 | * then have the mcount trampoline call the function directly. | |
cdbe61bf | 250 | */ |
b848914c | 251 | if (ftrace_ops_list == &ftrace_list_end || |
cdbe61bf | 252 | (ftrace_ops_list->next == &ftrace_list_end && |
2f5f6ad9 | 253 | !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC) && |
4740974a | 254 | (ftrace_ops_list->flags & FTRACE_OPS_FL_RECURSION_SAFE) && |
ccf3672d | 255 | !FTRACE_FORCE_LIST_FUNC)) { |
2f5f6ad9 | 256 | /* Set the ftrace_ops that the arch callback uses */ |
4104d326 | 257 | set_function_trace_op = ftrace_ops_list; |
b848914c | 258 | func = ftrace_ops_list->func; |
2f5f6ad9 SR |
259 | } else { |
260 | /* Just use the default ftrace_ops */ | |
405e1d83 | 261 | set_function_trace_op = &ftrace_list_end; |
b848914c | 262 | func = ftrace_ops_list_func; |
2f5f6ad9 | 263 | } |
2b499381 | 264 | |
405e1d83 SRRH |
265 | /* If there's no change, then do nothing more here */ |
266 | if (ftrace_trace_function == func) | |
267 | return; | |
268 | ||
23a8e844 SRRH |
269 | update_function_graph_func(); |
270 | ||
405e1d83 SRRH |
271 | /* |
272 | * If we are using the list function, it doesn't care | |
273 | * about the function_trace_ops. | |
274 | */ | |
275 | if (func == ftrace_ops_list_func) { | |
276 | ftrace_trace_function = func; | |
277 | /* | |
278 | * Don't even bother setting function_trace_ops, | |
279 | * it would be racy to do so anyway. | |
280 | */ | |
281 | return; | |
282 | } | |
283 | ||
284 | #ifndef CONFIG_DYNAMIC_FTRACE | |
285 | /* | |
286 | * For static tracing, we need to be a bit more careful. | |
287 | * The function change takes affect immediately. Thus, | |
288 | * we need to coorditate the setting of the function_trace_ops | |
289 | * with the setting of the ftrace_trace_function. | |
290 | * | |
291 | * Set the function to the list ops, which will call the | |
292 | * function we want, albeit indirectly, but it handles the | |
293 | * ftrace_ops and doesn't depend on function_trace_op. | |
294 | */ | |
295 | ftrace_trace_function = ftrace_ops_list_func; | |
296 | /* | |
297 | * Make sure all CPUs see this. Yes this is slow, but static | |
298 | * tracing is slow and nasty to have enabled. | |
299 | */ | |
300 | schedule_on_each_cpu(ftrace_sync); | |
301 | /* Now all cpus are using the list ops. */ | |
302 | function_trace_op = set_function_trace_op; | |
303 | /* Make sure the function_trace_op is visible on all CPUs */ | |
304 | smp_wmb(); | |
305 | /* Nasty way to force a rmb on all cpus */ | |
306 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
307 | /* OK, we are all set to update the ftrace_trace_function now! */ | |
308 | #endif /* !CONFIG_DYNAMIC_FTRACE */ | |
309 | ||
491d0dcf | 310 | ftrace_trace_function = func; |
491d0dcf SR |
311 | } |
312 | ||
7eea4fce JW |
313 | int using_ftrace_ops_list_func(void) |
314 | { | |
315 | return ftrace_trace_function == ftrace_ops_list_func; | |
316 | } | |
317 | ||
2b499381 | 318 | static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
3d083395 | 319 | { |
2b499381 | 320 | ops->next = *list; |
16444a8a | 321 | /* |
b848914c | 322 | * We are entering ops into the list but another |
16444a8a ACM |
323 | * CPU might be walking that list. We need to make sure |
324 | * the ops->next pointer is valid before another CPU sees | |
b848914c | 325 | * the ops pointer included into the list. |
16444a8a | 326 | */ |
2b499381 | 327 | rcu_assign_pointer(*list, ops); |
16444a8a ACM |
328 | } |
329 | ||
2b499381 | 330 | static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
16444a8a | 331 | { |
16444a8a | 332 | struct ftrace_ops **p; |
16444a8a ACM |
333 | |
334 | /* | |
3d083395 SR |
335 | * If we are removing the last function, then simply point |
336 | * to the ftrace_stub. | |
16444a8a | 337 | */ |
2b499381 SR |
338 | if (*list == ops && ops->next == &ftrace_list_end) { |
339 | *list = &ftrace_list_end; | |
e6ea44e9 | 340 | return 0; |
16444a8a ACM |
341 | } |
342 | ||
2b499381 | 343 | for (p = list; *p != &ftrace_list_end; p = &(*p)->next) |
16444a8a ACM |
344 | if (*p == ops) |
345 | break; | |
346 | ||
e6ea44e9 SR |
347 | if (*p != ops) |
348 | return -1; | |
16444a8a ACM |
349 | |
350 | *p = (*p)->next; | |
2b499381 SR |
351 | return 0; |
352 | } | |
16444a8a | 353 | |
e248491a JO |
354 | static void add_ftrace_list_ops(struct ftrace_ops **list, |
355 | struct ftrace_ops *main_ops, | |
356 | struct ftrace_ops *ops) | |
357 | { | |
358 | int first = *list == &ftrace_list_end; | |
359 | add_ftrace_ops(list, ops); | |
360 | if (first) | |
361 | add_ftrace_ops(&ftrace_ops_list, main_ops); | |
362 | } | |
363 | ||
364 | static int remove_ftrace_list_ops(struct ftrace_ops **list, | |
365 | struct ftrace_ops *main_ops, | |
366 | struct ftrace_ops *ops) | |
367 | { | |
368 | int ret = remove_ftrace_ops(list, ops); | |
369 | if (!ret && *list == &ftrace_list_end) | |
370 | ret = remove_ftrace_ops(&ftrace_ops_list, main_ops); | |
371 | return ret; | |
372 | } | |
373 | ||
2b499381 SR |
374 | static int __register_ftrace_function(struct ftrace_ops *ops) |
375 | { | |
591dffda SRRH |
376 | if (ops->flags & FTRACE_OPS_FL_DELETED) |
377 | return -EINVAL; | |
378 | ||
b848914c SR |
379 | if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) |
380 | return -EBUSY; | |
381 | ||
06aeaaea | 382 | #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
08f6fba5 SR |
383 | /* |
384 | * If the ftrace_ops specifies SAVE_REGS, then it only can be used | |
385 | * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set. | |
386 | * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant. | |
387 | */ | |
388 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS && | |
389 | !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)) | |
390 | return -EINVAL; | |
391 | ||
392 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED) | |
393 | ops->flags |= FTRACE_OPS_FL_SAVE_REGS; | |
394 | #endif | |
395 | ||
cdbe61bf SR |
396 | if (!core_kernel_data((unsigned long)ops)) |
397 | ops->flags |= FTRACE_OPS_FL_DYNAMIC; | |
398 | ||
4104d326 | 399 | if (ops->flags & FTRACE_OPS_FL_CONTROL) { |
e248491a JO |
400 | if (control_ops_alloc(ops)) |
401 | return -ENOMEM; | |
402 | add_ftrace_list_ops(&ftrace_control_list, &control_ops, ops); | |
b848914c SR |
403 | } else |
404 | add_ftrace_ops(&ftrace_ops_list, ops); | |
405 | ||
2b499381 SR |
406 | if (ftrace_enabled) |
407 | update_ftrace_function(); | |
408 | ||
409 | return 0; | |
410 | } | |
411 | ||
412 | static int __unregister_ftrace_function(struct ftrace_ops *ops) | |
413 | { | |
414 | int ret; | |
415 | ||
b848914c SR |
416 | if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) |
417 | return -EBUSY; | |
418 | ||
4104d326 | 419 | if (ops->flags & FTRACE_OPS_FL_CONTROL) { |
e248491a JO |
420 | ret = remove_ftrace_list_ops(&ftrace_control_list, |
421 | &control_ops, ops); | |
b848914c SR |
422 | } else |
423 | ret = remove_ftrace_ops(&ftrace_ops_list, ops); | |
424 | ||
2b499381 SR |
425 | if (ret < 0) |
426 | return ret; | |
b848914c | 427 | |
491d0dcf SR |
428 | if (ftrace_enabled) |
429 | update_ftrace_function(); | |
16444a8a | 430 | |
e6ea44e9 | 431 | return 0; |
3d083395 SR |
432 | } |
433 | ||
df4fc315 SR |
434 | static void ftrace_update_pid_func(void) |
435 | { | |
491d0dcf | 436 | /* Only do something if we are tracing something */ |
df4fc315 | 437 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 438 | return; |
df4fc315 | 439 | |
491d0dcf | 440 | update_ftrace_function(); |
df4fc315 SR |
441 | } |
442 | ||
493762fc SR |
443 | #ifdef CONFIG_FUNCTION_PROFILER |
444 | struct ftrace_profile { | |
445 | struct hlist_node node; | |
446 | unsigned long ip; | |
447 | unsigned long counter; | |
0706f1c4 SR |
448 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
449 | unsigned long long time; | |
e330b3bc | 450 | unsigned long long time_squared; |
0706f1c4 | 451 | #endif |
8fc0c701 SR |
452 | }; |
453 | ||
493762fc SR |
454 | struct ftrace_profile_page { |
455 | struct ftrace_profile_page *next; | |
456 | unsigned long index; | |
457 | struct ftrace_profile records[]; | |
d61f82d0 SR |
458 | }; |
459 | ||
cafb168a SR |
460 | struct ftrace_profile_stat { |
461 | atomic_t disabled; | |
462 | struct hlist_head *hash; | |
463 | struct ftrace_profile_page *pages; | |
464 | struct ftrace_profile_page *start; | |
465 | struct tracer_stat stat; | |
466 | }; | |
467 | ||
493762fc SR |
468 | #define PROFILE_RECORDS_SIZE \ |
469 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 470 | |
493762fc SR |
471 | #define PROFILES_PER_PAGE \ |
472 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 473 | |
fb9fb015 SR |
474 | static int ftrace_profile_enabled __read_mostly; |
475 | ||
476 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
477 | static DEFINE_MUTEX(ftrace_profile_lock); |
478 | ||
cafb168a | 479 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc | 480 | |
20079ebe NK |
481 | #define FTRACE_PROFILE_HASH_BITS 10 |
482 | #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS) | |
493762fc | 483 | |
bac429f0 SR |
484 | static void * |
485 | function_stat_next(void *v, int idx) | |
486 | { | |
493762fc SR |
487 | struct ftrace_profile *rec = v; |
488 | struct ftrace_profile_page *pg; | |
bac429f0 | 489 | |
493762fc | 490 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
491 | |
492 | again: | |
0296e425 LZ |
493 | if (idx != 0) |
494 | rec++; | |
495 | ||
bac429f0 SR |
496 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
497 | pg = pg->next; | |
498 | if (!pg) | |
499 | return NULL; | |
500 | rec = &pg->records[0]; | |
493762fc SR |
501 | if (!rec->counter) |
502 | goto again; | |
bac429f0 SR |
503 | } |
504 | ||
bac429f0 SR |
505 | return rec; |
506 | } | |
507 | ||
508 | static void *function_stat_start(struct tracer_stat *trace) | |
509 | { | |
cafb168a SR |
510 | struct ftrace_profile_stat *stat = |
511 | container_of(trace, struct ftrace_profile_stat, stat); | |
512 | ||
513 | if (!stat || !stat->start) | |
514 | return NULL; | |
515 | ||
516 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
517 | } |
518 | ||
0706f1c4 SR |
519 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
520 | /* function graph compares on total time */ | |
521 | static int function_stat_cmp(void *p1, void *p2) | |
522 | { | |
523 | struct ftrace_profile *a = p1; | |
524 | struct ftrace_profile *b = p2; | |
525 | ||
526 | if (a->time < b->time) | |
527 | return -1; | |
528 | if (a->time > b->time) | |
529 | return 1; | |
530 | else | |
531 | return 0; | |
532 | } | |
533 | #else | |
534 | /* not function graph compares against hits */ | |
bac429f0 SR |
535 | static int function_stat_cmp(void *p1, void *p2) |
536 | { | |
493762fc SR |
537 | struct ftrace_profile *a = p1; |
538 | struct ftrace_profile *b = p2; | |
bac429f0 SR |
539 | |
540 | if (a->counter < b->counter) | |
541 | return -1; | |
542 | if (a->counter > b->counter) | |
543 | return 1; | |
544 | else | |
545 | return 0; | |
546 | } | |
0706f1c4 | 547 | #endif |
bac429f0 SR |
548 | |
549 | static int function_stat_headers(struct seq_file *m) | |
550 | { | |
0706f1c4 | 551 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b | 552 | seq_printf(m, " Function " |
e330b3bc | 553 | "Hit Time Avg s^2\n" |
34886c8b | 554 | " -------- " |
e330b3bc | 555 | "--- ---- --- ---\n"); |
0706f1c4 | 556 | #else |
bac429f0 SR |
557 | seq_printf(m, " Function Hit\n" |
558 | " -------- ---\n"); | |
0706f1c4 | 559 | #endif |
bac429f0 SR |
560 | return 0; |
561 | } | |
562 | ||
563 | static int function_stat_show(struct seq_file *m, void *v) | |
564 | { | |
493762fc | 565 | struct ftrace_profile *rec = v; |
bac429f0 | 566 | char str[KSYM_SYMBOL_LEN]; |
3aaba20f | 567 | int ret = 0; |
0706f1c4 | 568 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
569 | static struct trace_seq s; |
570 | unsigned long long avg; | |
e330b3bc | 571 | unsigned long long stddev; |
0706f1c4 | 572 | #endif |
3aaba20f LZ |
573 | mutex_lock(&ftrace_profile_lock); |
574 | ||
575 | /* we raced with function_profile_reset() */ | |
576 | if (unlikely(rec->counter == 0)) { | |
577 | ret = -EBUSY; | |
578 | goto out; | |
579 | } | |
bac429f0 SR |
580 | |
581 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
0706f1c4 SR |
582 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
583 | ||
584 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
585 | seq_printf(m, " "); | |
34886c8b SR |
586 | avg = rec->time; |
587 | do_div(avg, rec->counter); | |
588 | ||
e330b3bc CD |
589 | /* Sample standard deviation (s^2) */ |
590 | if (rec->counter <= 1) | |
591 | stddev = 0; | |
592 | else { | |
52d85d76 JL |
593 | /* |
594 | * Apply Welford's method: | |
595 | * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2) | |
596 | */ | |
597 | stddev = rec->counter * rec->time_squared - | |
598 | rec->time * rec->time; | |
599 | ||
e330b3bc CD |
600 | /* |
601 | * Divide only 1000 for ns^2 -> us^2 conversion. | |
602 | * trace_print_graph_duration will divide 1000 again. | |
603 | */ | |
52d85d76 | 604 | do_div(stddev, rec->counter * (rec->counter - 1) * 1000); |
e330b3bc CD |
605 | } |
606 | ||
34886c8b SR |
607 | trace_seq_init(&s); |
608 | trace_print_graph_duration(rec->time, &s); | |
609 | trace_seq_puts(&s, " "); | |
610 | trace_print_graph_duration(avg, &s); | |
e330b3bc CD |
611 | trace_seq_puts(&s, " "); |
612 | trace_print_graph_duration(stddev, &s); | |
0706f1c4 | 613 | trace_print_seq(m, &s); |
0706f1c4 SR |
614 | #endif |
615 | seq_putc(m, '\n'); | |
3aaba20f LZ |
616 | out: |
617 | mutex_unlock(&ftrace_profile_lock); | |
bac429f0 | 618 | |
3aaba20f | 619 | return ret; |
bac429f0 SR |
620 | } |
621 | ||
cafb168a | 622 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 623 | { |
493762fc | 624 | struct ftrace_profile_page *pg; |
bac429f0 | 625 | |
cafb168a | 626 | pg = stat->pages = stat->start; |
bac429f0 | 627 | |
493762fc SR |
628 | while (pg) { |
629 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
630 | pg->index = 0; | |
631 | pg = pg->next; | |
bac429f0 SR |
632 | } |
633 | ||
cafb168a | 634 | memset(stat->hash, 0, |
493762fc SR |
635 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
636 | } | |
bac429f0 | 637 | |
cafb168a | 638 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
639 | { |
640 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
641 | int functions; |
642 | int pages; | |
493762fc | 643 | int i; |
bac429f0 | 644 | |
493762fc | 645 | /* If we already allocated, do nothing */ |
cafb168a | 646 | if (stat->pages) |
493762fc | 647 | return 0; |
bac429f0 | 648 | |
cafb168a SR |
649 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
650 | if (!stat->pages) | |
493762fc | 651 | return -ENOMEM; |
bac429f0 | 652 | |
318e0a73 SR |
653 | #ifdef CONFIG_DYNAMIC_FTRACE |
654 | functions = ftrace_update_tot_cnt; | |
655 | #else | |
656 | /* | |
657 | * We do not know the number of functions that exist because | |
658 | * dynamic tracing is what counts them. With past experience | |
659 | * we have around 20K functions. That should be more than enough. | |
660 | * It is highly unlikely we will execute every function in | |
661 | * the kernel. | |
662 | */ | |
663 | functions = 20000; | |
664 | #endif | |
665 | ||
cafb168a | 666 | pg = stat->start = stat->pages; |
bac429f0 | 667 | |
318e0a73 SR |
668 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
669 | ||
39e30cd1 | 670 | for (i = 1; i < pages; i++) { |
493762fc | 671 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 672 | if (!pg->next) |
318e0a73 | 673 | goto out_free; |
493762fc SR |
674 | pg = pg->next; |
675 | } | |
676 | ||
677 | return 0; | |
318e0a73 SR |
678 | |
679 | out_free: | |
680 | pg = stat->start; | |
681 | while (pg) { | |
682 | unsigned long tmp = (unsigned long)pg; | |
683 | ||
684 | pg = pg->next; | |
685 | free_page(tmp); | |
686 | } | |
687 | ||
318e0a73 SR |
688 | stat->pages = NULL; |
689 | stat->start = NULL; | |
690 | ||
691 | return -ENOMEM; | |
bac429f0 SR |
692 | } |
693 | ||
cafb168a | 694 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 695 | { |
cafb168a | 696 | struct ftrace_profile_stat *stat; |
493762fc | 697 | int size; |
bac429f0 | 698 | |
cafb168a SR |
699 | stat = &per_cpu(ftrace_profile_stats, cpu); |
700 | ||
701 | if (stat->hash) { | |
493762fc | 702 | /* If the profile is already created, simply reset it */ |
cafb168a | 703 | ftrace_profile_reset(stat); |
493762fc SR |
704 | return 0; |
705 | } | |
bac429f0 | 706 | |
493762fc SR |
707 | /* |
708 | * We are profiling all functions, but usually only a few thousand | |
709 | * functions are hit. We'll make a hash of 1024 items. | |
710 | */ | |
711 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 712 | |
cafb168a | 713 | stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
493762fc | 714 | |
cafb168a | 715 | if (!stat->hash) |
493762fc SR |
716 | return -ENOMEM; |
717 | ||
318e0a73 | 718 | /* Preallocate the function profiling pages */ |
cafb168a SR |
719 | if (ftrace_profile_pages_init(stat) < 0) { |
720 | kfree(stat->hash); | |
721 | stat->hash = NULL; | |
493762fc SR |
722 | return -ENOMEM; |
723 | } | |
724 | ||
725 | return 0; | |
bac429f0 SR |
726 | } |
727 | ||
cafb168a SR |
728 | static int ftrace_profile_init(void) |
729 | { | |
730 | int cpu; | |
731 | int ret = 0; | |
732 | ||
c4602c1c | 733 | for_each_possible_cpu(cpu) { |
cafb168a SR |
734 | ret = ftrace_profile_init_cpu(cpu); |
735 | if (ret) | |
736 | break; | |
737 | } | |
738 | ||
739 | return ret; | |
740 | } | |
741 | ||
493762fc | 742 | /* interrupts must be disabled */ |
cafb168a SR |
743 | static struct ftrace_profile * |
744 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 745 | { |
493762fc | 746 | struct ftrace_profile *rec; |
bac429f0 | 747 | struct hlist_head *hhd; |
bac429f0 SR |
748 | unsigned long key; |
749 | ||
20079ebe | 750 | key = hash_long(ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 751 | hhd = &stat->hash[key]; |
bac429f0 SR |
752 | |
753 | if (hlist_empty(hhd)) | |
754 | return NULL; | |
755 | ||
1bb539ca | 756 | hlist_for_each_entry_rcu_notrace(rec, hhd, node) { |
bac429f0 | 757 | if (rec->ip == ip) |
493762fc SR |
758 | return rec; |
759 | } | |
760 | ||
761 | return NULL; | |
762 | } | |
763 | ||
cafb168a SR |
764 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
765 | struct ftrace_profile *rec) | |
493762fc SR |
766 | { |
767 | unsigned long key; | |
768 | ||
20079ebe | 769 | key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 770 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
771 | } |
772 | ||
318e0a73 SR |
773 | /* |
774 | * The memory is already allocated, this simply finds a new record to use. | |
775 | */ | |
493762fc | 776 | static struct ftrace_profile * |
318e0a73 | 777 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
778 | { |
779 | struct ftrace_profile *rec = NULL; | |
780 | ||
318e0a73 | 781 | /* prevent recursion (from NMIs) */ |
cafb168a | 782 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
783 | goto out; |
784 | ||
493762fc | 785 | /* |
318e0a73 SR |
786 | * Try to find the function again since an NMI |
787 | * could have added it | |
493762fc | 788 | */ |
cafb168a | 789 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 790 | if (rec) |
cafb168a | 791 | goto out; |
493762fc | 792 | |
cafb168a SR |
793 | if (stat->pages->index == PROFILES_PER_PAGE) { |
794 | if (!stat->pages->next) | |
795 | goto out; | |
796 | stat->pages = stat->pages->next; | |
bac429f0 | 797 | } |
493762fc | 798 | |
cafb168a | 799 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 800 | rec->ip = ip; |
cafb168a | 801 | ftrace_add_profile(stat, rec); |
493762fc | 802 | |
bac429f0 | 803 | out: |
cafb168a | 804 | atomic_dec(&stat->disabled); |
bac429f0 SR |
805 | |
806 | return rec; | |
807 | } | |
808 | ||
809 | static void | |
2f5f6ad9 | 810 | function_profile_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 811 | struct ftrace_ops *ops, struct pt_regs *regs) |
bac429f0 | 812 | { |
cafb168a | 813 | struct ftrace_profile_stat *stat; |
493762fc | 814 | struct ftrace_profile *rec; |
bac429f0 SR |
815 | unsigned long flags; |
816 | ||
817 | if (!ftrace_profile_enabled) | |
818 | return; | |
819 | ||
820 | local_irq_save(flags); | |
cafb168a | 821 | |
bdffd893 | 822 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 823 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
824 | goto out; |
825 | ||
826 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 827 | if (!rec) { |
318e0a73 | 828 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
829 | if (!rec) |
830 | goto out; | |
831 | } | |
bac429f0 SR |
832 | |
833 | rec->counter++; | |
834 | out: | |
835 | local_irq_restore(flags); | |
836 | } | |
837 | ||
0706f1c4 SR |
838 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
839 | static int profile_graph_entry(struct ftrace_graph_ent *trace) | |
840 | { | |
a1e2e31d | 841 | function_profile_call(trace->func, 0, NULL, NULL); |
0706f1c4 SR |
842 | return 1; |
843 | } | |
844 | ||
845 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
846 | { | |
cafb168a | 847 | struct ftrace_profile_stat *stat; |
a2a16d6a | 848 | unsigned long long calltime; |
0706f1c4 | 849 | struct ftrace_profile *rec; |
cafb168a | 850 | unsigned long flags; |
0706f1c4 SR |
851 | |
852 | local_irq_save(flags); | |
bdffd893 | 853 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 854 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
855 | goto out; |
856 | ||
37e44bc5 SR |
857 | /* If the calltime was zero'd ignore it */ |
858 | if (!trace->calltime) | |
859 | goto out; | |
860 | ||
a2a16d6a SR |
861 | calltime = trace->rettime - trace->calltime; |
862 | ||
863 | if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) { | |
864 | int index; | |
865 | ||
866 | index = trace->depth; | |
867 | ||
868 | /* Append this call time to the parent time to subtract */ | |
869 | if (index) | |
870 | current->ret_stack[index - 1].subtime += calltime; | |
871 | ||
872 | if (current->ret_stack[index].subtime < calltime) | |
873 | calltime -= current->ret_stack[index].subtime; | |
874 | else | |
875 | calltime = 0; | |
876 | } | |
877 | ||
cafb168a | 878 | rec = ftrace_find_profiled_func(stat, trace->func); |
e330b3bc | 879 | if (rec) { |
a2a16d6a | 880 | rec->time += calltime; |
e330b3bc CD |
881 | rec->time_squared += calltime * calltime; |
882 | } | |
a2a16d6a | 883 | |
cafb168a | 884 | out: |
0706f1c4 SR |
885 | local_irq_restore(flags); |
886 | } | |
887 | ||
888 | static int register_ftrace_profiler(void) | |
889 | { | |
890 | return register_ftrace_graph(&profile_graph_return, | |
891 | &profile_graph_entry); | |
892 | } | |
893 | ||
894 | static void unregister_ftrace_profiler(void) | |
895 | { | |
896 | unregister_ftrace_graph(); | |
897 | } | |
898 | #else | |
bd38c0e6 | 899 | static struct ftrace_ops ftrace_profile_ops __read_mostly = { |
fb9fb015 | 900 | .func = function_profile_call, |
f04f24fb MH |
901 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, |
902 | INIT_REGEX_LOCK(ftrace_profile_ops) | |
bac429f0 SR |
903 | }; |
904 | ||
0706f1c4 SR |
905 | static int register_ftrace_profiler(void) |
906 | { | |
907 | return register_ftrace_function(&ftrace_profile_ops); | |
908 | } | |
909 | ||
910 | static void unregister_ftrace_profiler(void) | |
911 | { | |
912 | unregister_ftrace_function(&ftrace_profile_ops); | |
913 | } | |
914 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
915 | ||
bac429f0 SR |
916 | static ssize_t |
917 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
918 | size_t cnt, loff_t *ppos) | |
919 | { | |
920 | unsigned long val; | |
bac429f0 SR |
921 | int ret; |
922 | ||
22fe9b54 PH |
923 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
924 | if (ret) | |
bac429f0 SR |
925 | return ret; |
926 | ||
927 | val = !!val; | |
928 | ||
929 | mutex_lock(&ftrace_profile_lock); | |
930 | if (ftrace_profile_enabled ^ val) { | |
931 | if (val) { | |
493762fc SR |
932 | ret = ftrace_profile_init(); |
933 | if (ret < 0) { | |
934 | cnt = ret; | |
935 | goto out; | |
936 | } | |
937 | ||
0706f1c4 SR |
938 | ret = register_ftrace_profiler(); |
939 | if (ret < 0) { | |
940 | cnt = ret; | |
941 | goto out; | |
942 | } | |
bac429f0 SR |
943 | ftrace_profile_enabled = 1; |
944 | } else { | |
945 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
946 | /* |
947 | * unregister_ftrace_profiler calls stop_machine | |
948 | * so this acts like an synchronize_sched. | |
949 | */ | |
0706f1c4 | 950 | unregister_ftrace_profiler(); |
bac429f0 SR |
951 | } |
952 | } | |
493762fc | 953 | out: |
bac429f0 SR |
954 | mutex_unlock(&ftrace_profile_lock); |
955 | ||
cf8517cf | 956 | *ppos += cnt; |
bac429f0 SR |
957 | |
958 | return cnt; | |
959 | } | |
960 | ||
493762fc SR |
961 | static ssize_t |
962 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
963 | size_t cnt, loff_t *ppos) | |
964 | { | |
fb9fb015 | 965 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
966 | int r; |
967 | ||
968 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
969 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
970 | } | |
971 | ||
bac429f0 SR |
972 | static const struct file_operations ftrace_profile_fops = { |
973 | .open = tracing_open_generic, | |
974 | .read = ftrace_profile_read, | |
975 | .write = ftrace_profile_write, | |
6038f373 | 976 | .llseek = default_llseek, |
bac429f0 SR |
977 | }; |
978 | ||
cafb168a SR |
979 | /* used to initialize the real stat files */ |
980 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
981 | .name = "functions", |
982 | .stat_start = function_stat_start, | |
983 | .stat_next = function_stat_next, | |
984 | .stat_cmp = function_stat_cmp, | |
985 | .stat_headers = function_stat_headers, | |
986 | .stat_show = function_stat_show | |
cafb168a SR |
987 | }; |
988 | ||
6ab5d668 | 989 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 | 990 | { |
cafb168a | 991 | struct ftrace_profile_stat *stat; |
bac429f0 | 992 | struct dentry *entry; |
cafb168a | 993 | char *name; |
bac429f0 | 994 | int ret; |
cafb168a SR |
995 | int cpu; |
996 | ||
997 | for_each_possible_cpu(cpu) { | |
998 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
999 | ||
1000 | /* allocate enough for function name + cpu number */ | |
1001 | name = kmalloc(32, GFP_KERNEL); | |
1002 | if (!name) { | |
1003 | /* | |
1004 | * The files created are permanent, if something happens | |
1005 | * we still do not free memory. | |
1006 | */ | |
cafb168a SR |
1007 | WARN(1, |
1008 | "Could not allocate stat file for cpu %d\n", | |
1009 | cpu); | |
1010 | return; | |
1011 | } | |
1012 | stat->stat = function_stats; | |
1013 | snprintf(name, 32, "function%d", cpu); | |
1014 | stat->stat.name = name; | |
1015 | ret = register_stat_tracer(&stat->stat); | |
1016 | if (ret) { | |
1017 | WARN(1, | |
1018 | "Could not register function stat for cpu %d\n", | |
1019 | cpu); | |
1020 | kfree(name); | |
1021 | return; | |
1022 | } | |
bac429f0 SR |
1023 | } |
1024 | ||
1025 | entry = debugfs_create_file("function_profile_enabled", 0644, | |
1026 | d_tracer, NULL, &ftrace_profile_fops); | |
1027 | if (!entry) | |
1028 | pr_warning("Could not create debugfs " | |
1029 | "'function_profile_enabled' entry\n"); | |
1030 | } | |
1031 | ||
bac429f0 | 1032 | #else /* CONFIG_FUNCTION_PROFILER */ |
6ab5d668 | 1033 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 SR |
1034 | { |
1035 | } | |
bac429f0 SR |
1036 | #endif /* CONFIG_FUNCTION_PROFILER */ |
1037 | ||
493762fc SR |
1038 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; |
1039 | ||
1040 | #ifdef CONFIG_DYNAMIC_FTRACE | |
1041 | ||
79922b80 SRRH |
1042 | static struct ftrace_ops *removed_ops; |
1043 | ||
493762fc SR |
1044 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
1045 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
1046 | #endif | |
1047 | ||
1048 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; | |
1049 | ||
1050 | struct ftrace_func_probe { | |
1051 | struct hlist_node node; | |
1052 | struct ftrace_probe_ops *ops; | |
1053 | unsigned long flags; | |
1054 | unsigned long ip; | |
1055 | void *data; | |
7818b388 | 1056 | struct list_head free_list; |
493762fc SR |
1057 | }; |
1058 | ||
b448c4e3 SR |
1059 | struct ftrace_func_entry { |
1060 | struct hlist_node hlist; | |
1061 | unsigned long ip; | |
1062 | }; | |
1063 | ||
1064 | struct ftrace_hash { | |
1065 | unsigned long size_bits; | |
1066 | struct hlist_head *buckets; | |
1067 | unsigned long count; | |
07fd5515 | 1068 | struct rcu_head rcu; |
b448c4e3 SR |
1069 | }; |
1070 | ||
33dc9b12 SR |
1071 | /* |
1072 | * We make these constant because no one should touch them, | |
1073 | * but they are used as the default "empty hash", to avoid allocating | |
1074 | * it all the time. These are in a read only section such that if | |
1075 | * anyone does try to modify it, it will cause an exception. | |
1076 | */ | |
1077 | static const struct hlist_head empty_buckets[1]; | |
1078 | static const struct ftrace_hash empty_hash = { | |
1079 | .buckets = (struct hlist_head *)empty_buckets, | |
1cf41dd7 | 1080 | }; |
33dc9b12 | 1081 | #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash) |
493762fc | 1082 | |
2b499381 | 1083 | static struct ftrace_ops global_ops = { |
f45948e8 | 1084 | .func = ftrace_stub, |
33dc9b12 SR |
1085 | .notrace_hash = EMPTY_HASH, |
1086 | .filter_hash = EMPTY_HASH, | |
f04f24fb MH |
1087 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, |
1088 | INIT_REGEX_LOCK(global_ops) | |
f45948e8 SR |
1089 | }; |
1090 | ||
493762fc SR |
1091 | struct ftrace_page { |
1092 | struct ftrace_page *next; | |
a7900875 | 1093 | struct dyn_ftrace *records; |
493762fc | 1094 | int index; |
a7900875 | 1095 | int size; |
493762fc SR |
1096 | }; |
1097 | ||
a7900875 SR |
1098 | #define ENTRY_SIZE sizeof(struct dyn_ftrace) |
1099 | #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE) | |
493762fc SR |
1100 | |
1101 | /* estimate from running different kernels */ | |
1102 | #define NR_TO_INIT 10000 | |
1103 | ||
1104 | static struct ftrace_page *ftrace_pages_start; | |
1105 | static struct ftrace_page *ftrace_pages; | |
1106 | ||
68f40969 | 1107 | static bool __always_inline ftrace_hash_empty(struct ftrace_hash *hash) |
06a51d93 SR |
1108 | { |
1109 | return !hash || !hash->count; | |
1110 | } | |
1111 | ||
b448c4e3 SR |
1112 | static struct ftrace_func_entry * |
1113 | ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
1114 | { | |
1115 | unsigned long key; | |
1116 | struct ftrace_func_entry *entry; | |
1117 | struct hlist_head *hhd; | |
b448c4e3 | 1118 | |
06a51d93 | 1119 | if (ftrace_hash_empty(hash)) |
b448c4e3 SR |
1120 | return NULL; |
1121 | ||
1122 | if (hash->size_bits > 0) | |
1123 | key = hash_long(ip, hash->size_bits); | |
1124 | else | |
1125 | key = 0; | |
1126 | ||
1127 | hhd = &hash->buckets[key]; | |
1128 | ||
1bb539ca | 1129 | hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) { |
b448c4e3 SR |
1130 | if (entry->ip == ip) |
1131 | return entry; | |
1132 | } | |
1133 | return NULL; | |
1134 | } | |
1135 | ||
33dc9b12 SR |
1136 | static void __add_hash_entry(struct ftrace_hash *hash, |
1137 | struct ftrace_func_entry *entry) | |
b448c4e3 | 1138 | { |
b448c4e3 SR |
1139 | struct hlist_head *hhd; |
1140 | unsigned long key; | |
1141 | ||
b448c4e3 | 1142 | if (hash->size_bits) |
33dc9b12 | 1143 | key = hash_long(entry->ip, hash->size_bits); |
b448c4e3 SR |
1144 | else |
1145 | key = 0; | |
1146 | ||
b448c4e3 SR |
1147 | hhd = &hash->buckets[key]; |
1148 | hlist_add_head(&entry->hlist, hhd); | |
1149 | hash->count++; | |
33dc9b12 SR |
1150 | } |
1151 | ||
1152 | static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip) | |
1153 | { | |
1154 | struct ftrace_func_entry *entry; | |
1155 | ||
1156 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1157 | if (!entry) | |
1158 | return -ENOMEM; | |
1159 | ||
1160 | entry->ip = ip; | |
1161 | __add_hash_entry(hash, entry); | |
b448c4e3 SR |
1162 | |
1163 | return 0; | |
1164 | } | |
1165 | ||
1166 | static void | |
33dc9b12 | 1167 | free_hash_entry(struct ftrace_hash *hash, |
b448c4e3 SR |
1168 | struct ftrace_func_entry *entry) |
1169 | { | |
1170 | hlist_del(&entry->hlist); | |
1171 | kfree(entry); | |
1172 | hash->count--; | |
1173 | } | |
1174 | ||
33dc9b12 SR |
1175 | static void |
1176 | remove_hash_entry(struct ftrace_hash *hash, | |
1177 | struct ftrace_func_entry *entry) | |
1178 | { | |
1179 | hlist_del(&entry->hlist); | |
1180 | hash->count--; | |
1181 | } | |
1182 | ||
b448c4e3 SR |
1183 | static void ftrace_hash_clear(struct ftrace_hash *hash) |
1184 | { | |
1185 | struct hlist_head *hhd; | |
b67bfe0d | 1186 | struct hlist_node *tn; |
b448c4e3 SR |
1187 | struct ftrace_func_entry *entry; |
1188 | int size = 1 << hash->size_bits; | |
1189 | int i; | |
1190 | ||
33dc9b12 SR |
1191 | if (!hash->count) |
1192 | return; | |
1193 | ||
b448c4e3 SR |
1194 | for (i = 0; i < size; i++) { |
1195 | hhd = &hash->buckets[i]; | |
b67bfe0d | 1196 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) |
33dc9b12 | 1197 | free_hash_entry(hash, entry); |
b448c4e3 SR |
1198 | } |
1199 | FTRACE_WARN_ON(hash->count); | |
1200 | } | |
1201 | ||
33dc9b12 SR |
1202 | static void free_ftrace_hash(struct ftrace_hash *hash) |
1203 | { | |
1204 | if (!hash || hash == EMPTY_HASH) | |
1205 | return; | |
1206 | ftrace_hash_clear(hash); | |
1207 | kfree(hash->buckets); | |
1208 | kfree(hash); | |
1209 | } | |
1210 | ||
07fd5515 SR |
1211 | static void __free_ftrace_hash_rcu(struct rcu_head *rcu) |
1212 | { | |
1213 | struct ftrace_hash *hash; | |
1214 | ||
1215 | hash = container_of(rcu, struct ftrace_hash, rcu); | |
1216 | free_ftrace_hash(hash); | |
1217 | } | |
1218 | ||
1219 | static void free_ftrace_hash_rcu(struct ftrace_hash *hash) | |
1220 | { | |
1221 | if (!hash || hash == EMPTY_HASH) | |
1222 | return; | |
1223 | call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu); | |
1224 | } | |
1225 | ||
5500fa51 JO |
1226 | void ftrace_free_filter(struct ftrace_ops *ops) |
1227 | { | |
f04f24fb | 1228 | ftrace_ops_init(ops); |
5500fa51 JO |
1229 | free_ftrace_hash(ops->filter_hash); |
1230 | free_ftrace_hash(ops->notrace_hash); | |
1231 | } | |
1232 | ||
33dc9b12 SR |
1233 | static struct ftrace_hash *alloc_ftrace_hash(int size_bits) |
1234 | { | |
1235 | struct ftrace_hash *hash; | |
1236 | int size; | |
1237 | ||
1238 | hash = kzalloc(sizeof(*hash), GFP_KERNEL); | |
1239 | if (!hash) | |
1240 | return NULL; | |
1241 | ||
1242 | size = 1 << size_bits; | |
47b0edcb | 1243 | hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL); |
33dc9b12 SR |
1244 | |
1245 | if (!hash->buckets) { | |
1246 | kfree(hash); | |
1247 | return NULL; | |
1248 | } | |
1249 | ||
1250 | hash->size_bits = size_bits; | |
1251 | ||
1252 | return hash; | |
1253 | } | |
1254 | ||
1255 | static struct ftrace_hash * | |
1256 | alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) | |
1257 | { | |
1258 | struct ftrace_func_entry *entry; | |
1259 | struct ftrace_hash *new_hash; | |
33dc9b12 SR |
1260 | int size; |
1261 | int ret; | |
1262 | int i; | |
1263 | ||
1264 | new_hash = alloc_ftrace_hash(size_bits); | |
1265 | if (!new_hash) | |
1266 | return NULL; | |
1267 | ||
1268 | /* Empty hash? */ | |
06a51d93 | 1269 | if (ftrace_hash_empty(hash)) |
33dc9b12 SR |
1270 | return new_hash; |
1271 | ||
1272 | size = 1 << hash->size_bits; | |
1273 | for (i = 0; i < size; i++) { | |
b67bfe0d | 1274 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { |
33dc9b12 SR |
1275 | ret = add_hash_entry(new_hash, entry->ip); |
1276 | if (ret < 0) | |
1277 | goto free_hash; | |
1278 | } | |
1279 | } | |
1280 | ||
1281 | FTRACE_WARN_ON(new_hash->count != hash->count); | |
1282 | ||
1283 | return new_hash; | |
1284 | ||
1285 | free_hash: | |
1286 | free_ftrace_hash(new_hash); | |
1287 | return NULL; | |
1288 | } | |
1289 | ||
41fb61c2 SR |
1290 | static void |
1291 | ftrace_hash_rec_disable(struct ftrace_ops *ops, int filter_hash); | |
1292 | static void | |
1293 | ftrace_hash_rec_enable(struct ftrace_ops *ops, int filter_hash); | |
1294 | ||
33dc9b12 | 1295 | static int |
41fb61c2 SR |
1296 | ftrace_hash_move(struct ftrace_ops *ops, int enable, |
1297 | struct ftrace_hash **dst, struct ftrace_hash *src) | |
33dc9b12 SR |
1298 | { |
1299 | struct ftrace_func_entry *entry; | |
b67bfe0d | 1300 | struct hlist_node *tn; |
33dc9b12 | 1301 | struct hlist_head *hhd; |
07fd5515 SR |
1302 | struct ftrace_hash *old_hash; |
1303 | struct ftrace_hash *new_hash; | |
33dc9b12 SR |
1304 | int size = src->count; |
1305 | int bits = 0; | |
1306 | int i; | |
1307 | ||
1308 | /* | |
1309 | * If the new source is empty, just free dst and assign it | |
1310 | * the empty_hash. | |
1311 | */ | |
1312 | if (!src->count) { | |
5c27c775 MH |
1313 | new_hash = EMPTY_HASH; |
1314 | goto update; | |
33dc9b12 SR |
1315 | } |
1316 | ||
33dc9b12 SR |
1317 | /* |
1318 | * Make the hash size about 1/2 the # found | |
1319 | */ | |
1320 | for (size /= 2; size; size >>= 1) | |
1321 | bits++; | |
1322 | ||
1323 | /* Don't allocate too much */ | |
1324 | if (bits > FTRACE_HASH_MAX_BITS) | |
1325 | bits = FTRACE_HASH_MAX_BITS; | |
1326 | ||
07fd5515 SR |
1327 | new_hash = alloc_ftrace_hash(bits); |
1328 | if (!new_hash) | |
5c27c775 | 1329 | return -ENOMEM; |
33dc9b12 SR |
1330 | |
1331 | size = 1 << src->size_bits; | |
1332 | for (i = 0; i < size; i++) { | |
1333 | hhd = &src->buckets[i]; | |
b67bfe0d | 1334 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) { |
33dc9b12 | 1335 | remove_hash_entry(src, entry); |
07fd5515 | 1336 | __add_hash_entry(new_hash, entry); |
33dc9b12 SR |
1337 | } |
1338 | } | |
1339 | ||
5c27c775 MH |
1340 | update: |
1341 | /* | |
1342 | * Remove the current set, update the hash and add | |
1343 | * them back. | |
1344 | */ | |
1345 | ftrace_hash_rec_disable(ops, enable); | |
1346 | ||
07fd5515 SR |
1347 | old_hash = *dst; |
1348 | rcu_assign_pointer(*dst, new_hash); | |
1349 | free_ftrace_hash_rcu(old_hash); | |
1350 | ||
41fb61c2 SR |
1351 | ftrace_hash_rec_enable(ops, enable); |
1352 | ||
5c27c775 | 1353 | return 0; |
33dc9b12 SR |
1354 | } |
1355 | ||
b848914c SR |
1356 | /* |
1357 | * Test the hashes for this ops to see if we want to call | |
1358 | * the ops->func or not. | |
1359 | * | |
1360 | * It's a match if the ip is in the ops->filter_hash or | |
1361 | * the filter_hash does not exist or is empty, | |
1362 | * AND | |
1363 | * the ip is not in the ops->notrace_hash. | |
cdbe61bf SR |
1364 | * |
1365 | * This needs to be called with preemption disabled as | |
1366 | * the hashes are freed with call_rcu_sched(). | |
b848914c SR |
1367 | */ |
1368 | static int | |
195a8afc | 1369 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
b848914c SR |
1370 | { |
1371 | struct ftrace_hash *filter_hash; | |
1372 | struct ftrace_hash *notrace_hash; | |
1373 | int ret; | |
1374 | ||
195a8afc SRRH |
1375 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
1376 | /* | |
1377 | * There's a small race when adding ops that the ftrace handler | |
1378 | * that wants regs, may be called without them. We can not | |
1379 | * allow that handler to be called if regs is NULL. | |
1380 | */ | |
1381 | if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS)) | |
1382 | return 0; | |
1383 | #endif | |
1384 | ||
1bb539ca SR |
1385 | filter_hash = rcu_dereference_raw_notrace(ops->filter_hash); |
1386 | notrace_hash = rcu_dereference_raw_notrace(ops->notrace_hash); | |
b848914c | 1387 | |
06a51d93 | 1388 | if ((ftrace_hash_empty(filter_hash) || |
b848914c | 1389 | ftrace_lookup_ip(filter_hash, ip)) && |
06a51d93 | 1390 | (ftrace_hash_empty(notrace_hash) || |
b848914c SR |
1391 | !ftrace_lookup_ip(notrace_hash, ip))) |
1392 | ret = 1; | |
1393 | else | |
1394 | ret = 0; | |
b848914c SR |
1395 | |
1396 | return ret; | |
1397 | } | |
1398 | ||
493762fc SR |
1399 | /* |
1400 | * This is a double for. Do not use 'break' to break out of the loop, | |
1401 | * you must use a goto. | |
1402 | */ | |
1403 | #define do_for_each_ftrace_rec(pg, rec) \ | |
1404 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
1405 | int _____i; \ | |
1406 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
1407 | rec = &pg->records[_____i]; | |
1408 | ||
1409 | #define while_for_each_ftrace_rec() \ | |
1410 | } \ | |
1411 | } | |
1412 | ||
5855fead SR |
1413 | |
1414 | static int ftrace_cmp_recs(const void *a, const void *b) | |
1415 | { | |
a650e02a SR |
1416 | const struct dyn_ftrace *key = a; |
1417 | const struct dyn_ftrace *rec = b; | |
5855fead | 1418 | |
a650e02a | 1419 | if (key->flags < rec->ip) |
5855fead | 1420 | return -1; |
a650e02a SR |
1421 | if (key->ip >= rec->ip + MCOUNT_INSN_SIZE) |
1422 | return 1; | |
5855fead SR |
1423 | return 0; |
1424 | } | |
1425 | ||
f0cf973a | 1426 | static unsigned long ftrace_location_range(unsigned long start, unsigned long end) |
c88fd863 SR |
1427 | { |
1428 | struct ftrace_page *pg; | |
1429 | struct dyn_ftrace *rec; | |
5855fead | 1430 | struct dyn_ftrace key; |
c88fd863 | 1431 | |
a650e02a SR |
1432 | key.ip = start; |
1433 | key.flags = end; /* overload flags, as it is unsigned long */ | |
5855fead SR |
1434 | |
1435 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
a650e02a SR |
1436 | if (end < pg->records[0].ip || |
1437 | start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) | |
9644302e | 1438 | continue; |
5855fead SR |
1439 | rec = bsearch(&key, pg->records, pg->index, |
1440 | sizeof(struct dyn_ftrace), | |
1441 | ftrace_cmp_recs); | |
1442 | if (rec) | |
f0cf973a | 1443 | return rec->ip; |
5855fead | 1444 | } |
c88fd863 SR |
1445 | |
1446 | return 0; | |
1447 | } | |
1448 | ||
a650e02a SR |
1449 | /** |
1450 | * ftrace_location - return true if the ip giving is a traced location | |
1451 | * @ip: the instruction pointer to check | |
1452 | * | |
f0cf973a | 1453 | * Returns rec->ip if @ip given is a pointer to a ftrace location. |
a650e02a SR |
1454 | * That is, the instruction that is either a NOP or call to |
1455 | * the function tracer. It checks the ftrace internal tables to | |
1456 | * determine if the address belongs or not. | |
1457 | */ | |
f0cf973a | 1458 | unsigned long ftrace_location(unsigned long ip) |
a650e02a SR |
1459 | { |
1460 | return ftrace_location_range(ip, ip); | |
1461 | } | |
1462 | ||
1463 | /** | |
1464 | * ftrace_text_reserved - return true if range contains an ftrace location | |
1465 | * @start: start of range to search | |
1466 | * @end: end of range to search (inclusive). @end points to the last byte to check. | |
1467 | * | |
1468 | * Returns 1 if @start and @end contains a ftrace location. | |
1469 | * That is, the instruction that is either a NOP or call to | |
1470 | * the function tracer. It checks the ftrace internal tables to | |
1471 | * determine if the address belongs or not. | |
1472 | */ | |
d88471cb | 1473 | int ftrace_text_reserved(const void *start, const void *end) |
a650e02a | 1474 | { |
f0cf973a SR |
1475 | unsigned long ret; |
1476 | ||
1477 | ret = ftrace_location_range((unsigned long)start, | |
1478 | (unsigned long)end); | |
1479 | ||
1480 | return (int)!!ret; | |
a650e02a SR |
1481 | } |
1482 | ||
4fbb48cb SRRH |
1483 | /* Test if ops registered to this rec needs regs */ |
1484 | static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec) | |
1485 | { | |
1486 | struct ftrace_ops *ops; | |
1487 | bool keep_regs = false; | |
1488 | ||
1489 | for (ops = ftrace_ops_list; | |
1490 | ops != &ftrace_list_end; ops = ops->next) { | |
1491 | /* pass rec in as regs to have non-NULL val */ | |
1492 | if (ftrace_ops_test(ops, rec->ip, rec)) { | |
1493 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1494 | keep_regs = true; | |
1495 | break; | |
1496 | } | |
1497 | } | |
1498 | } | |
1499 | ||
1500 | return keep_regs; | |
1501 | } | |
1502 | ||
79922b80 SRRH |
1503 | static void ftrace_remove_tramp(struct ftrace_ops *ops, |
1504 | struct dyn_ftrace *rec) | |
1505 | { | |
1506 | struct ftrace_func_entry *entry; | |
1507 | ||
1508 | entry = ftrace_lookup_ip(ops->tramp_hash, rec->ip); | |
1509 | if (!entry) | |
1510 | return; | |
1511 | ||
1512 | /* | |
1513 | * The tramp_hash entry will be removed at time | |
1514 | * of update. | |
1515 | */ | |
0162d621 | 1516 | ops->nr_trampolines--; |
79922b80 SRRH |
1517 | rec->flags &= ~FTRACE_FL_TRAMP; |
1518 | } | |
1519 | ||
1520 | static void ftrace_clear_tramps(struct dyn_ftrace *rec) | |
1521 | { | |
1522 | struct ftrace_ops *op; | |
1523 | ||
1524 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
0162d621 | 1525 | if (op->nr_trampolines) |
79922b80 SRRH |
1526 | ftrace_remove_tramp(op, rec); |
1527 | } while_for_each_ftrace_op(op); | |
1528 | } | |
1529 | ||
ed926f9b SR |
1530 | static void __ftrace_hash_rec_update(struct ftrace_ops *ops, |
1531 | int filter_hash, | |
1532 | bool inc) | |
1533 | { | |
1534 | struct ftrace_hash *hash; | |
1535 | struct ftrace_hash *other_hash; | |
1536 | struct ftrace_page *pg; | |
1537 | struct dyn_ftrace *rec; | |
1538 | int count = 0; | |
1539 | int all = 0; | |
1540 | ||
1541 | /* Only update if the ops has been registered */ | |
1542 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
1543 | return; | |
1544 | ||
1545 | /* | |
1546 | * In the filter_hash case: | |
1547 | * If the count is zero, we update all records. | |
1548 | * Otherwise we just update the items in the hash. | |
1549 | * | |
1550 | * In the notrace_hash case: | |
1551 | * We enable the update in the hash. | |
1552 | * As disabling notrace means enabling the tracing, | |
1553 | * and enabling notrace means disabling, the inc variable | |
1554 | * gets inversed. | |
1555 | */ | |
1556 | if (filter_hash) { | |
1557 | hash = ops->filter_hash; | |
1558 | other_hash = ops->notrace_hash; | |
06a51d93 | 1559 | if (ftrace_hash_empty(hash)) |
ed926f9b SR |
1560 | all = 1; |
1561 | } else { | |
1562 | inc = !inc; | |
1563 | hash = ops->notrace_hash; | |
1564 | other_hash = ops->filter_hash; | |
1565 | /* | |
1566 | * If the notrace hash has no items, | |
1567 | * then there's nothing to do. | |
1568 | */ | |
06a51d93 | 1569 | if (ftrace_hash_empty(hash)) |
ed926f9b SR |
1570 | return; |
1571 | } | |
1572 | ||
1573 | do_for_each_ftrace_rec(pg, rec) { | |
1574 | int in_other_hash = 0; | |
1575 | int in_hash = 0; | |
1576 | int match = 0; | |
1577 | ||
1578 | if (all) { | |
1579 | /* | |
1580 | * Only the filter_hash affects all records. | |
1581 | * Update if the record is not in the notrace hash. | |
1582 | */ | |
b848914c | 1583 | if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) |
ed926f9b SR |
1584 | match = 1; |
1585 | } else { | |
06a51d93 SR |
1586 | in_hash = !!ftrace_lookup_ip(hash, rec->ip); |
1587 | in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip); | |
ed926f9b SR |
1588 | |
1589 | /* | |
19eab4a4 SRRH |
1590 | * If filter_hash is set, we want to match all functions |
1591 | * that are in the hash but not in the other hash. | |
ed926f9b | 1592 | * |
19eab4a4 SRRH |
1593 | * If filter_hash is not set, then we are decrementing. |
1594 | * That means we match anything that is in the hash | |
1595 | * and also in the other_hash. That is, we need to turn | |
1596 | * off functions in the other hash because they are disabled | |
1597 | * by this hash. | |
ed926f9b SR |
1598 | */ |
1599 | if (filter_hash && in_hash && !in_other_hash) | |
1600 | match = 1; | |
1601 | else if (!filter_hash && in_hash && | |
06a51d93 | 1602 | (in_other_hash || ftrace_hash_empty(other_hash))) |
ed926f9b SR |
1603 | match = 1; |
1604 | } | |
1605 | if (!match) | |
1606 | continue; | |
1607 | ||
1608 | if (inc) { | |
1609 | rec->flags++; | |
0376bde1 | 1610 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX)) |
ed926f9b | 1611 | return; |
79922b80 SRRH |
1612 | |
1613 | /* | |
1614 | * If there's only a single callback registered to a | |
1615 | * function, and the ops has a trampoline registered | |
1616 | * for it, then we can call it directly. | |
1617 | */ | |
1618 | if (ftrace_rec_count(rec) == 1 && ops->trampoline) { | |
1619 | rec->flags |= FTRACE_FL_TRAMP; | |
0162d621 | 1620 | ops->nr_trampolines++; |
79922b80 SRRH |
1621 | } else { |
1622 | /* | |
1623 | * If we are adding another function callback | |
1624 | * to this function, and the previous had a | |
1625 | * trampoline used, then we need to go back to | |
1626 | * the default trampoline. | |
1627 | */ | |
1628 | rec->flags &= ~FTRACE_FL_TRAMP; | |
1629 | ||
1630 | /* remove trampolines from any ops for this rec */ | |
1631 | ftrace_clear_tramps(rec); | |
1632 | } | |
1633 | ||
08f6fba5 SR |
1634 | /* |
1635 | * If any ops wants regs saved for this function | |
1636 | * then all ops will get saved regs. | |
1637 | */ | |
1638 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) | |
1639 | rec->flags |= FTRACE_FL_REGS; | |
ed926f9b | 1640 | } else { |
0376bde1 | 1641 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0)) |
ed926f9b SR |
1642 | return; |
1643 | rec->flags--; | |
79922b80 SRRH |
1644 | |
1645 | if (ops->trampoline && !ftrace_rec_count(rec)) | |
1646 | ftrace_remove_tramp(ops, rec); | |
1647 | ||
4fbb48cb SRRH |
1648 | /* |
1649 | * If the rec had REGS enabled and the ops that is | |
1650 | * being removed had REGS set, then see if there is | |
1651 | * still any ops for this record that wants regs. | |
1652 | * If not, we can stop recording them. | |
1653 | */ | |
0376bde1 | 1654 | if (ftrace_rec_count(rec) > 0 && |
4fbb48cb SRRH |
1655 | rec->flags & FTRACE_FL_REGS && |
1656 | ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1657 | if (!test_rec_ops_needs_regs(rec)) | |
1658 | rec->flags &= ~FTRACE_FL_REGS; | |
1659 | } | |
79922b80 SRRH |
1660 | |
1661 | /* | |
1662 | * flags will be cleared in ftrace_check_record() | |
1663 | * if rec count is zero. | |
1664 | */ | |
ed926f9b SR |
1665 | } |
1666 | count++; | |
1667 | /* Shortcut, if we handled all records, we are done. */ | |
1668 | if (!all && count == hash->count) | |
1669 | return; | |
1670 | } while_for_each_ftrace_rec(); | |
1671 | } | |
1672 | ||
1673 | static void ftrace_hash_rec_disable(struct ftrace_ops *ops, | |
1674 | int filter_hash) | |
1675 | { | |
1676 | __ftrace_hash_rec_update(ops, filter_hash, 0); | |
1677 | } | |
1678 | ||
1679 | static void ftrace_hash_rec_enable(struct ftrace_ops *ops, | |
1680 | int filter_hash) | |
1681 | { | |
1682 | __ftrace_hash_rec_update(ops, filter_hash, 1); | |
1683 | } | |
1684 | ||
b17e8a37 SR |
1685 | static void print_ip_ins(const char *fmt, unsigned char *p) |
1686 | { | |
1687 | int i; | |
1688 | ||
1689 | printk(KERN_CONT "%s", fmt); | |
1690 | ||
1691 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
1692 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
1693 | } | |
1694 | ||
c88fd863 SR |
1695 | /** |
1696 | * ftrace_bug - report and shutdown function tracer | |
1697 | * @failed: The failed type (EFAULT, EINVAL, EPERM) | |
1698 | * @ip: The address that failed | |
1699 | * | |
1700 | * The arch code that enables or disables the function tracing | |
1701 | * can call ftrace_bug() when it has detected a problem in | |
1702 | * modifying the code. @failed should be one of either: | |
1703 | * EFAULT - if the problem happens on reading the @ip address | |
1704 | * EINVAL - if what is read at @ip is not what was expected | |
1705 | * EPERM - if the problem happens on writting to the @ip address | |
1706 | */ | |
1707 | void ftrace_bug(int failed, unsigned long ip) | |
b17e8a37 SR |
1708 | { |
1709 | switch (failed) { | |
1710 | case -EFAULT: | |
1711 | FTRACE_WARN_ON_ONCE(1); | |
1712 | pr_info("ftrace faulted on modifying "); | |
1713 | print_ip_sym(ip); | |
1714 | break; | |
1715 | case -EINVAL: | |
1716 | FTRACE_WARN_ON_ONCE(1); | |
1717 | pr_info("ftrace failed to modify "); | |
1718 | print_ip_sym(ip); | |
b17e8a37 | 1719 | print_ip_ins(" actual: ", (unsigned char *)ip); |
b17e8a37 SR |
1720 | printk(KERN_CONT "\n"); |
1721 | break; | |
1722 | case -EPERM: | |
1723 | FTRACE_WARN_ON_ONCE(1); | |
1724 | pr_info("ftrace faulted on writing "); | |
1725 | print_ip_sym(ip); | |
1726 | break; | |
1727 | default: | |
1728 | FTRACE_WARN_ON_ONCE(1); | |
1729 | pr_info("ftrace faulted on unknown error "); | |
1730 | print_ip_sym(ip); | |
1731 | } | |
1732 | } | |
1733 | ||
c88fd863 | 1734 | static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update) |
5072c59f | 1735 | { |
64fbcd16 | 1736 | unsigned long flag = 0UL; |
e7d3737e | 1737 | |
982c350b | 1738 | /* |
30fb6aa7 | 1739 | * If we are updating calls: |
982c350b | 1740 | * |
ed926f9b SR |
1741 | * If the record has a ref count, then we need to enable it |
1742 | * because someone is using it. | |
982c350b | 1743 | * |
ed926f9b SR |
1744 | * Otherwise we make sure its disabled. |
1745 | * | |
30fb6aa7 | 1746 | * If we are disabling calls, then disable all records that |
ed926f9b | 1747 | * are enabled. |
982c350b | 1748 | */ |
0376bde1 | 1749 | if (enable && ftrace_rec_count(rec)) |
ed926f9b | 1750 | flag = FTRACE_FL_ENABLED; |
982c350b | 1751 | |
08f6fba5 | 1752 | /* |
79922b80 SRRH |
1753 | * If enabling and the REGS flag does not match the REGS_EN, or |
1754 | * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore | |
1755 | * this record. Set flags to fail the compare against ENABLED. | |
08f6fba5 | 1756 | */ |
79922b80 SRRH |
1757 | if (flag) { |
1758 | if (!(rec->flags & FTRACE_FL_REGS) != | |
1759 | !(rec->flags & FTRACE_FL_REGS_EN)) | |
1760 | flag |= FTRACE_FL_REGS; | |
1761 | ||
1762 | if (!(rec->flags & FTRACE_FL_TRAMP) != | |
1763 | !(rec->flags & FTRACE_FL_TRAMP_EN)) | |
1764 | flag |= FTRACE_FL_TRAMP; | |
1765 | } | |
08f6fba5 | 1766 | |
64fbcd16 XG |
1767 | /* If the state of this record hasn't changed, then do nothing */ |
1768 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
c88fd863 | 1769 | return FTRACE_UPDATE_IGNORE; |
982c350b | 1770 | |
64fbcd16 | 1771 | if (flag) { |
08f6fba5 SR |
1772 | /* Save off if rec is being enabled (for return value) */ |
1773 | flag ^= rec->flags & FTRACE_FL_ENABLED; | |
1774 | ||
1775 | if (update) { | |
c88fd863 | 1776 | rec->flags |= FTRACE_FL_ENABLED; |
08f6fba5 SR |
1777 | if (flag & FTRACE_FL_REGS) { |
1778 | if (rec->flags & FTRACE_FL_REGS) | |
1779 | rec->flags |= FTRACE_FL_REGS_EN; | |
1780 | else | |
1781 | rec->flags &= ~FTRACE_FL_REGS_EN; | |
1782 | } | |
79922b80 SRRH |
1783 | if (flag & FTRACE_FL_TRAMP) { |
1784 | if (rec->flags & FTRACE_FL_TRAMP) | |
1785 | rec->flags |= FTRACE_FL_TRAMP_EN; | |
1786 | else | |
1787 | rec->flags &= ~FTRACE_FL_TRAMP_EN; | |
1788 | } | |
08f6fba5 SR |
1789 | } |
1790 | ||
1791 | /* | |
1792 | * If this record is being updated from a nop, then | |
1793 | * return UPDATE_MAKE_CALL. | |
08f6fba5 SR |
1794 | * Otherwise, |
1795 | * return UPDATE_MODIFY_CALL to tell the caller to convert | |
f1b2f2bd | 1796 | * from the save regs, to a non-save regs function or |
79922b80 | 1797 | * vice versa, or from a trampoline call. |
08f6fba5 SR |
1798 | */ |
1799 | if (flag & FTRACE_FL_ENABLED) | |
1800 | return FTRACE_UPDATE_MAKE_CALL; | |
f1b2f2bd SRRH |
1801 | |
1802 | return FTRACE_UPDATE_MODIFY_CALL; | |
c88fd863 SR |
1803 | } |
1804 | ||
08f6fba5 SR |
1805 | if (update) { |
1806 | /* If there's no more users, clear all flags */ | |
0376bde1 | 1807 | if (!ftrace_rec_count(rec)) |
08f6fba5 SR |
1808 | rec->flags = 0; |
1809 | else | |
1810 | /* Just disable the record (keep REGS state) */ | |
1811 | rec->flags &= ~FTRACE_FL_ENABLED; | |
1812 | } | |
c88fd863 SR |
1813 | |
1814 | return FTRACE_UPDATE_MAKE_NOP; | |
1815 | } | |
1816 | ||
1817 | /** | |
1818 | * ftrace_update_record, set a record that now is tracing or not | |
1819 | * @rec: the record to update | |
1820 | * @enable: set to 1 if the record is tracing, zero to force disable | |
1821 | * | |
1822 | * The records that represent all functions that can be traced need | |
1823 | * to be updated when tracing has been enabled. | |
1824 | */ | |
1825 | int ftrace_update_record(struct dyn_ftrace *rec, int enable) | |
1826 | { | |
1827 | return ftrace_check_record(rec, enable, 1); | |
1828 | } | |
1829 | ||
1830 | /** | |
1831 | * ftrace_test_record, check if the record has been enabled or not | |
1832 | * @rec: the record to test | |
1833 | * @enable: set to 1 to check if enabled, 0 if it is disabled | |
1834 | * | |
1835 | * The arch code may need to test if a record is already set to | |
1836 | * tracing to determine how to modify the function code that it | |
1837 | * represents. | |
1838 | */ | |
1839 | int ftrace_test_record(struct dyn_ftrace *rec, int enable) | |
1840 | { | |
1841 | return ftrace_check_record(rec, enable, 0); | |
1842 | } | |
1843 | ||
79922b80 SRRH |
1844 | static struct ftrace_ops * |
1845 | ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec) | |
1846 | { | |
1847 | struct ftrace_ops *op; | |
1848 | ||
1849 | /* Removed ops need to be tested first */ | |
1850 | if (removed_ops && removed_ops->tramp_hash) { | |
1851 | if (ftrace_lookup_ip(removed_ops->tramp_hash, rec->ip)) | |
1852 | return removed_ops; | |
1853 | } | |
1854 | ||
1855 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1856 | if (!op->tramp_hash) | |
1857 | continue; | |
1858 | ||
1859 | if (ftrace_lookup_ip(op->tramp_hash, rec->ip)) | |
1860 | return op; | |
1861 | ||
1862 | } while_for_each_ftrace_op(op); | |
1863 | ||
1864 | return NULL; | |
1865 | } | |
1866 | ||
1867 | static struct ftrace_ops * | |
1868 | ftrace_find_tramp_ops_new(struct dyn_ftrace *rec) | |
1869 | { | |
1870 | struct ftrace_ops *op; | |
1871 | ||
1872 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1873 | /* pass rec in as regs to have non-NULL val */ | |
1874 | if (ftrace_ops_test(op, rec->ip, rec)) | |
1875 | return op; | |
1876 | } while_for_each_ftrace_op(op); | |
1877 | ||
1878 | return NULL; | |
1879 | } | |
1880 | ||
7413af1f SRRH |
1881 | /** |
1882 | * ftrace_get_addr_new - Get the call address to set to | |
1883 | * @rec: The ftrace record descriptor | |
1884 | * | |
1885 | * If the record has the FTRACE_FL_REGS set, that means that it | |
1886 | * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS | |
1887 | * is not not set, then it wants to convert to the normal callback. | |
1888 | * | |
1889 | * Returns the address of the trampoline to set to | |
1890 | */ | |
1891 | unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec) | |
1892 | { | |
79922b80 SRRH |
1893 | struct ftrace_ops *ops; |
1894 | ||
1895 | /* Trampolines take precedence over regs */ | |
1896 | if (rec->flags & FTRACE_FL_TRAMP) { | |
1897 | ops = ftrace_find_tramp_ops_new(rec); | |
1898 | if (FTRACE_WARN_ON(!ops || !ops->trampoline)) { | |
1899 | pr_warning("Bad trampoline accounting at: %p (%pS)\n", | |
1900 | (void *)rec->ip, (void *)rec->ip); | |
1901 | /* Ftrace is shutting down, return anything */ | |
1902 | return (unsigned long)FTRACE_ADDR; | |
1903 | } | |
1904 | return ops->trampoline; | |
1905 | } | |
1906 | ||
7413af1f SRRH |
1907 | if (rec->flags & FTRACE_FL_REGS) |
1908 | return (unsigned long)FTRACE_REGS_ADDR; | |
1909 | else | |
1910 | return (unsigned long)FTRACE_ADDR; | |
1911 | } | |
1912 | ||
1913 | /** | |
1914 | * ftrace_get_addr_curr - Get the call address that is already there | |
1915 | * @rec: The ftrace record descriptor | |
1916 | * | |
1917 | * The FTRACE_FL_REGS_EN is set when the record already points to | |
1918 | * a function that saves all the regs. Basically the '_EN' version | |
1919 | * represents the current state of the function. | |
1920 | * | |
1921 | * Returns the address of the trampoline that is currently being called | |
1922 | */ | |
1923 | unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec) | |
1924 | { | |
79922b80 SRRH |
1925 | struct ftrace_ops *ops; |
1926 | ||
1927 | /* Trampolines take precedence over regs */ | |
1928 | if (rec->flags & FTRACE_FL_TRAMP_EN) { | |
1929 | ops = ftrace_find_tramp_ops_curr(rec); | |
1930 | if (FTRACE_WARN_ON(!ops)) { | |
1931 | pr_warning("Bad trampoline accounting at: %p (%pS)\n", | |
1932 | (void *)rec->ip, (void *)rec->ip); | |
1933 | /* Ftrace is shutting down, return anything */ | |
1934 | return (unsigned long)FTRACE_ADDR; | |
1935 | } | |
1936 | return ops->trampoline; | |
1937 | } | |
1938 | ||
7413af1f SRRH |
1939 | if (rec->flags & FTRACE_FL_REGS_EN) |
1940 | return (unsigned long)FTRACE_REGS_ADDR; | |
1941 | else | |
1942 | return (unsigned long)FTRACE_ADDR; | |
1943 | } | |
1944 | ||
c88fd863 SR |
1945 | static int |
1946 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) | |
1947 | { | |
08f6fba5 | 1948 | unsigned long ftrace_old_addr; |
c88fd863 SR |
1949 | unsigned long ftrace_addr; |
1950 | int ret; | |
1951 | ||
7c0868e0 | 1952 | ftrace_addr = ftrace_get_addr_new(rec); |
c88fd863 | 1953 | |
7c0868e0 SRRH |
1954 | /* This needs to be done before we call ftrace_update_record */ |
1955 | ftrace_old_addr = ftrace_get_addr_curr(rec); | |
1956 | ||
1957 | ret = ftrace_update_record(rec, enable); | |
08f6fba5 | 1958 | |
c88fd863 SR |
1959 | switch (ret) { |
1960 | case FTRACE_UPDATE_IGNORE: | |
1961 | return 0; | |
1962 | ||
1963 | case FTRACE_UPDATE_MAKE_CALL: | |
64fbcd16 | 1964 | return ftrace_make_call(rec, ftrace_addr); |
c88fd863 SR |
1965 | |
1966 | case FTRACE_UPDATE_MAKE_NOP: | |
1967 | return ftrace_make_nop(NULL, rec, ftrace_addr); | |
08f6fba5 | 1968 | |
08f6fba5 | 1969 | case FTRACE_UPDATE_MODIFY_CALL: |
08f6fba5 | 1970 | return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr); |
5072c59f SR |
1971 | } |
1972 | ||
c88fd863 | 1973 | return -1; /* unknow ftrace bug */ |
5072c59f SR |
1974 | } |
1975 | ||
e4f5d544 | 1976 | void __weak ftrace_replace_code(int enable) |
3c1720f0 | 1977 | { |
3c1720f0 SR |
1978 | struct dyn_ftrace *rec; |
1979 | struct ftrace_page *pg; | |
6a24a244 | 1980 | int failed; |
3c1720f0 | 1981 | |
45a4a237 SR |
1982 | if (unlikely(ftrace_disabled)) |
1983 | return; | |
1984 | ||
265c831c | 1985 | do_for_each_ftrace_rec(pg, rec) { |
e4f5d544 | 1986 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 1987 | if (failed) { |
3279ba37 SR |
1988 | ftrace_bug(failed, rec->ip); |
1989 | /* Stop processing */ | |
1990 | return; | |
3c1720f0 | 1991 | } |
265c831c | 1992 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
1993 | } |
1994 | ||
c88fd863 SR |
1995 | struct ftrace_rec_iter { |
1996 | struct ftrace_page *pg; | |
1997 | int index; | |
1998 | }; | |
1999 | ||
2000 | /** | |
2001 | * ftrace_rec_iter_start, start up iterating over traced functions | |
2002 | * | |
2003 | * Returns an iterator handle that is used to iterate over all | |
2004 | * the records that represent address locations where functions | |
2005 | * are traced. | |
2006 | * | |
2007 | * May return NULL if no records are available. | |
2008 | */ | |
2009 | struct ftrace_rec_iter *ftrace_rec_iter_start(void) | |
2010 | { | |
2011 | /* | |
2012 | * We only use a single iterator. | |
2013 | * Protected by the ftrace_lock mutex. | |
2014 | */ | |
2015 | static struct ftrace_rec_iter ftrace_rec_iter; | |
2016 | struct ftrace_rec_iter *iter = &ftrace_rec_iter; | |
2017 | ||
2018 | iter->pg = ftrace_pages_start; | |
2019 | iter->index = 0; | |
2020 | ||
2021 | /* Could have empty pages */ | |
2022 | while (iter->pg && !iter->pg->index) | |
2023 | iter->pg = iter->pg->next; | |
2024 | ||
2025 | if (!iter->pg) | |
2026 | return NULL; | |
2027 | ||
2028 | return iter; | |
2029 | } | |
2030 | ||
2031 | /** | |
2032 | * ftrace_rec_iter_next, get the next record to process. | |
2033 | * @iter: The handle to the iterator. | |
2034 | * | |
2035 | * Returns the next iterator after the given iterator @iter. | |
2036 | */ | |
2037 | struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) | |
2038 | { | |
2039 | iter->index++; | |
2040 | ||
2041 | if (iter->index >= iter->pg->index) { | |
2042 | iter->pg = iter->pg->next; | |
2043 | iter->index = 0; | |
2044 | ||
2045 | /* Could have empty pages */ | |
2046 | while (iter->pg && !iter->pg->index) | |
2047 | iter->pg = iter->pg->next; | |
2048 | } | |
2049 | ||
2050 | if (!iter->pg) | |
2051 | return NULL; | |
2052 | ||
2053 | return iter; | |
2054 | } | |
2055 | ||
2056 | /** | |
2057 | * ftrace_rec_iter_record, get the record at the iterator location | |
2058 | * @iter: The current iterator location | |
2059 | * | |
2060 | * Returns the record that the current @iter is at. | |
2061 | */ | |
2062 | struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) | |
2063 | { | |
2064 | return &iter->pg->records[iter->index]; | |
2065 | } | |
2066 | ||
492a7ea5 | 2067 | static int |
31e88909 | 2068 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 SR |
2069 | { |
2070 | unsigned long ip; | |
593eb8a2 | 2071 | int ret; |
3c1720f0 SR |
2072 | |
2073 | ip = rec->ip; | |
2074 | ||
45a4a237 SR |
2075 | if (unlikely(ftrace_disabled)) |
2076 | return 0; | |
2077 | ||
25aac9dc | 2078 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 2079 | if (ret) { |
31e88909 | 2080 | ftrace_bug(ret, ip); |
492a7ea5 | 2081 | return 0; |
37ad5084 | 2082 | } |
492a7ea5 | 2083 | return 1; |
3c1720f0 SR |
2084 | } |
2085 | ||
000ab691 SR |
2086 | /* |
2087 | * archs can override this function if they must do something | |
2088 | * before the modifying code is performed. | |
2089 | */ | |
2090 | int __weak ftrace_arch_code_modify_prepare(void) | |
2091 | { | |
2092 | return 0; | |
2093 | } | |
2094 | ||
2095 | /* | |
2096 | * archs can override this function if they must do something | |
2097 | * after the modifying code is performed. | |
2098 | */ | |
2099 | int __weak ftrace_arch_code_modify_post_process(void) | |
2100 | { | |
2101 | return 0; | |
2102 | } | |
2103 | ||
8ed3e2cf | 2104 | void ftrace_modify_all_code(int command) |
3d083395 | 2105 | { |
59338f75 | 2106 | int update = command & FTRACE_UPDATE_TRACE_FUNC; |
cd21067f | 2107 | int err = 0; |
59338f75 SRRH |
2108 | |
2109 | /* | |
2110 | * If the ftrace_caller calls a ftrace_ops func directly, | |
2111 | * we need to make sure that it only traces functions it | |
2112 | * expects to trace. When doing the switch of functions, | |
2113 | * we need to update to the ftrace_ops_list_func first | |
2114 | * before the transition between old and new calls are set, | |
2115 | * as the ftrace_ops_list_func will check the ops hashes | |
2116 | * to make sure the ops are having the right functions | |
2117 | * traced. | |
2118 | */ | |
cd21067f PM |
2119 | if (update) { |
2120 | err = ftrace_update_ftrace_func(ftrace_ops_list_func); | |
2121 | if (FTRACE_WARN_ON(err)) | |
2122 | return; | |
2123 | } | |
59338f75 | 2124 | |
8ed3e2cf | 2125 | if (command & FTRACE_UPDATE_CALLS) |
d61f82d0 | 2126 | ftrace_replace_code(1); |
8ed3e2cf | 2127 | else if (command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
2128 | ftrace_replace_code(0); |
2129 | ||
405e1d83 SRRH |
2130 | if (update && ftrace_trace_function != ftrace_ops_list_func) { |
2131 | function_trace_op = set_function_trace_op; | |
2132 | smp_wmb(); | |
2133 | /* If irqs are disabled, we are in stop machine */ | |
2134 | if (!irqs_disabled()) | |
2135 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
cd21067f PM |
2136 | err = ftrace_update_ftrace_func(ftrace_trace_function); |
2137 | if (FTRACE_WARN_ON(err)) | |
2138 | return; | |
405e1d83 | 2139 | } |
d61f82d0 | 2140 | |
8ed3e2cf | 2141 | if (command & FTRACE_START_FUNC_RET) |
cd21067f | 2142 | err = ftrace_enable_ftrace_graph_caller(); |
8ed3e2cf | 2143 | else if (command & FTRACE_STOP_FUNC_RET) |
cd21067f PM |
2144 | err = ftrace_disable_ftrace_graph_caller(); |
2145 | FTRACE_WARN_ON(err); | |
8ed3e2cf SR |
2146 | } |
2147 | ||
2148 | static int __ftrace_modify_code(void *data) | |
2149 | { | |
2150 | int *command = data; | |
2151 | ||
2152 | ftrace_modify_all_code(*command); | |
5a45cfe1 | 2153 | |
d61f82d0 | 2154 | return 0; |
3d083395 SR |
2155 | } |
2156 | ||
c88fd863 SR |
2157 | /** |
2158 | * ftrace_run_stop_machine, go back to the stop machine method | |
2159 | * @command: The command to tell ftrace what to do | |
2160 | * | |
2161 | * If an arch needs to fall back to the stop machine method, the | |
2162 | * it can call this function. | |
2163 | */ | |
2164 | void ftrace_run_stop_machine(int command) | |
2165 | { | |
2166 | stop_machine(__ftrace_modify_code, &command, NULL); | |
2167 | } | |
2168 | ||
2169 | /** | |
2170 | * arch_ftrace_update_code, modify the code to trace or not trace | |
2171 | * @command: The command that needs to be done | |
2172 | * | |
2173 | * Archs can override this function if it does not need to | |
2174 | * run stop_machine() to modify code. | |
2175 | */ | |
2176 | void __weak arch_ftrace_update_code(int command) | |
2177 | { | |
2178 | ftrace_run_stop_machine(command); | |
2179 | } | |
2180 | ||
79922b80 SRRH |
2181 | static int ftrace_save_ops_tramp_hash(struct ftrace_ops *ops) |
2182 | { | |
2183 | struct ftrace_page *pg; | |
2184 | struct dyn_ftrace *rec; | |
2185 | int size, bits; | |
2186 | int ret; | |
2187 | ||
0162d621 | 2188 | size = ops->nr_trampolines; |
79922b80 SRRH |
2189 | bits = 0; |
2190 | /* | |
2191 | * Make the hash size about 1/2 the # found | |
2192 | */ | |
2193 | for (size /= 2; size; size >>= 1) | |
2194 | bits++; | |
2195 | ||
2196 | ops->tramp_hash = alloc_ftrace_hash(bits); | |
2197 | /* | |
2198 | * TODO: a failed allocation is going to screw up | |
2199 | * the accounting of what needs to be modified | |
2200 | * and not. For now, we kill ftrace if we fail | |
2201 | * to allocate here. But there are ways around this, | |
2202 | * but that will take a little more work. | |
2203 | */ | |
2204 | if (!ops->tramp_hash) | |
2205 | return -ENOMEM; | |
2206 | ||
2207 | do_for_each_ftrace_rec(pg, rec) { | |
2208 | if (ftrace_rec_count(rec) == 1 && | |
2209 | ftrace_ops_test(ops, rec->ip, rec)) { | |
2210 | ||
2a0343ba SRRH |
2211 | /* |
2212 | * If another ops adds to a rec, the rec will | |
2213 | * lose its trampoline and never get it back | |
2214 | * until all ops are off of it. | |
2215 | */ | |
2216 | if (!(rec->flags & FTRACE_FL_TRAMP)) | |
2217 | continue; | |
2218 | ||
79922b80 SRRH |
2219 | /* This record had better have a trampoline */ |
2220 | if (FTRACE_WARN_ON(!(rec->flags & FTRACE_FL_TRAMP_EN))) | |
2221 | return -1; | |
2222 | ||
2223 | ret = add_hash_entry(ops->tramp_hash, rec->ip); | |
2224 | if (ret < 0) | |
2225 | return ret; | |
2226 | } | |
2227 | } while_for_each_ftrace_rec(); | |
2228 | ||
2229 | return 0; | |
2230 | } | |
2231 | ||
2232 | static int ftrace_save_tramp_hashes(void) | |
2233 | { | |
2234 | struct ftrace_ops *op; | |
2235 | int ret; | |
2236 | ||
2237 | /* | |
2238 | * Now that any trampoline is being used, we need to save the | |
2239 | * hashes for the ops that have them. This allows the mapping | |
2240 | * back from the record to the ops that has the trampoline to | |
2241 | * know what code is being replaced. Modifying code must always | |
2242 | * verify what it is changing. | |
2243 | */ | |
2244 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2245 | ||
2246 | /* The tramp_hash is recreated each time. */ | |
2247 | free_ftrace_hash(op->tramp_hash); | |
2248 | op->tramp_hash = NULL; | |
2249 | ||
0162d621 | 2250 | if (op->nr_trampolines) { |
79922b80 SRRH |
2251 | ret = ftrace_save_ops_tramp_hash(op); |
2252 | if (ret) | |
2253 | return ret; | |
2254 | } | |
2255 | ||
2256 | } while_for_each_ftrace_op(op); | |
2257 | ||
2258 | return 0; | |
2259 | } | |
2260 | ||
e309b41d | 2261 | static void ftrace_run_update_code(int command) |
3d083395 | 2262 | { |
000ab691 SR |
2263 | int ret; |
2264 | ||
2265 | ret = ftrace_arch_code_modify_prepare(); | |
2266 | FTRACE_WARN_ON(ret); | |
2267 | if (ret) | |
2268 | return; | |
2269 | ||
c88fd863 SR |
2270 | /* |
2271 | * By default we use stop_machine() to modify the code. | |
2272 | * But archs can do what ever they want as long as it | |
2273 | * is safe. The stop_machine() is the safest, but also | |
2274 | * produces the most overhead. | |
2275 | */ | |
2276 | arch_ftrace_update_code(command); | |
2277 | ||
000ab691 SR |
2278 | ret = ftrace_arch_code_modify_post_process(); |
2279 | FTRACE_WARN_ON(ret); | |
79922b80 SRRH |
2280 | |
2281 | ret = ftrace_save_tramp_hashes(); | |
2282 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
2283 | } |
2284 | ||
d61f82d0 | 2285 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 2286 | static int ftrace_start_up; |
df4fc315 | 2287 | |
db0fbadc JS |
2288 | static void control_ops_free(struct ftrace_ops *ops) |
2289 | { | |
2290 | free_percpu(ops->disabled); | |
2291 | } | |
2292 | ||
df4fc315 SR |
2293 | static void ftrace_startup_enable(int command) |
2294 | { | |
2295 | if (saved_ftrace_func != ftrace_trace_function) { | |
2296 | saved_ftrace_func = ftrace_trace_function; | |
2297 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2298 | } | |
2299 | ||
2300 | if (!command || !ftrace_enabled) | |
2301 | return; | |
2302 | ||
2303 | ftrace_run_update_code(command); | |
2304 | } | |
d61f82d0 | 2305 | |
a1cd6173 | 2306 | static int ftrace_startup(struct ftrace_ops *ops, int command) |
3d083395 | 2307 | { |
8a56d776 | 2308 | int ret; |
b848914c | 2309 | |
4eebcc81 | 2310 | if (unlikely(ftrace_disabled)) |
a1cd6173 | 2311 | return -ENODEV; |
4eebcc81 | 2312 | |
8a56d776 SRRH |
2313 | ret = __register_ftrace_function(ops); |
2314 | if (ret) | |
2315 | return ret; | |
2316 | ||
60a7ecf4 | 2317 | ftrace_start_up++; |
30fb6aa7 | 2318 | command |= FTRACE_UPDATE_CALLS; |
d61f82d0 | 2319 | |
ed926f9b | 2320 | ops->flags |= FTRACE_OPS_FL_ENABLED; |
66209a5b SRRH |
2321 | |
2322 | ftrace_hash_rec_enable(ops, 1); | |
ed926f9b | 2323 | |
df4fc315 | 2324 | ftrace_startup_enable(command); |
a1cd6173 SR |
2325 | |
2326 | return 0; | |
3d083395 SR |
2327 | } |
2328 | ||
8a56d776 | 2329 | static int ftrace_shutdown(struct ftrace_ops *ops, int command) |
3d083395 | 2330 | { |
8a56d776 | 2331 | int ret; |
b848914c | 2332 | |
4eebcc81 | 2333 | if (unlikely(ftrace_disabled)) |
8a56d776 SRRH |
2334 | return -ENODEV; |
2335 | ||
2336 | ret = __unregister_ftrace_function(ops); | |
2337 | if (ret) | |
2338 | return ret; | |
4eebcc81 | 2339 | |
60a7ecf4 | 2340 | ftrace_start_up--; |
9ea1a153 FW |
2341 | /* |
2342 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
2343 | * critical but the ftrace_call callers may be never nopped again after | |
2344 | * further ftrace uses. | |
2345 | */ | |
2346 | WARN_ON_ONCE(ftrace_start_up < 0); | |
2347 | ||
66209a5b | 2348 | ftrace_hash_rec_disable(ops, 1); |
ed926f9b | 2349 | |
a737e6dd | 2350 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
b848914c | 2351 | |
30fb6aa7 | 2352 | command |= FTRACE_UPDATE_CALLS; |
3d083395 | 2353 | |
d61f82d0 SR |
2354 | if (saved_ftrace_func != ftrace_trace_function) { |
2355 | saved_ftrace_func = ftrace_trace_function; | |
2356 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2357 | } | |
3d083395 | 2358 | |
a4c35ed2 SRRH |
2359 | if (!command || !ftrace_enabled) { |
2360 | /* | |
2361 | * If these are control ops, they still need their | |
2362 | * per_cpu field freed. Since, function tracing is | |
2363 | * not currently active, we can just free them | |
2364 | * without synchronizing all CPUs. | |
2365 | */ | |
2366 | if (ops->flags & FTRACE_OPS_FL_CONTROL) | |
2367 | control_ops_free(ops); | |
8a56d776 | 2368 | return 0; |
a4c35ed2 | 2369 | } |
d61f82d0 | 2370 | |
79922b80 SRRH |
2371 | /* |
2372 | * If the ops uses a trampoline, then it needs to be | |
2373 | * tested first on update. | |
2374 | */ | |
2375 | removed_ops = ops; | |
2376 | ||
d61f82d0 | 2377 | ftrace_run_update_code(command); |
a4c35ed2 | 2378 | |
79922b80 SRRH |
2379 | removed_ops = NULL; |
2380 | ||
a4c35ed2 SRRH |
2381 | /* |
2382 | * Dynamic ops may be freed, we must make sure that all | |
2383 | * callers are done before leaving this function. | |
2384 | * The same goes for freeing the per_cpu data of the control | |
2385 | * ops. | |
2386 | * | |
2387 | * Again, normal synchronize_sched() is not good enough. | |
2388 | * We need to do a hard force of sched synchronization. | |
2389 | * This is because we use preempt_disable() to do RCU, but | |
2390 | * the function tracers can be called where RCU is not watching | |
2391 | * (like before user_exit()). We can not rely on the RCU | |
2392 | * infrastructure to do the synchronization, thus we must do it | |
2393 | * ourselves. | |
2394 | */ | |
2395 | if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_CONTROL)) { | |
2396 | schedule_on_each_cpu(ftrace_sync); | |
2397 | ||
2398 | if (ops->flags & FTRACE_OPS_FL_CONTROL) | |
2399 | control_ops_free(ops); | |
2400 | } | |
2401 | ||
8a56d776 | 2402 | return 0; |
3d083395 SR |
2403 | } |
2404 | ||
e309b41d | 2405 | static void ftrace_startup_sysctl(void) |
b0fc494f | 2406 | { |
4eebcc81 SR |
2407 | if (unlikely(ftrace_disabled)) |
2408 | return; | |
2409 | ||
d61f82d0 SR |
2410 | /* Force update next time */ |
2411 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
2412 | /* ftrace_start_up is true if we want ftrace running */ |
2413 | if (ftrace_start_up) | |
30fb6aa7 | 2414 | ftrace_run_update_code(FTRACE_UPDATE_CALLS); |
b0fc494f SR |
2415 | } |
2416 | ||
e309b41d | 2417 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 2418 | { |
4eebcc81 SR |
2419 | if (unlikely(ftrace_disabled)) |
2420 | return; | |
2421 | ||
60a7ecf4 SR |
2422 | /* ftrace_start_up is true if ftrace is running */ |
2423 | if (ftrace_start_up) | |
79e406d7 | 2424 | ftrace_run_update_code(FTRACE_DISABLE_CALLS); |
b0fc494f SR |
2425 | } |
2426 | ||
3d083395 | 2427 | static cycle_t ftrace_update_time; |
3d083395 SR |
2428 | unsigned long ftrace_update_tot_cnt; |
2429 | ||
8c4f3c3f | 2430 | static inline int ops_traces_mod(struct ftrace_ops *ops) |
f7bc8b61 | 2431 | { |
8c4f3c3f SRRH |
2432 | /* |
2433 | * Filter_hash being empty will default to trace module. | |
2434 | * But notrace hash requires a test of individual module functions. | |
2435 | */ | |
2436 | return ftrace_hash_empty(ops->filter_hash) && | |
2437 | ftrace_hash_empty(ops->notrace_hash); | |
2438 | } | |
2439 | ||
2440 | /* | |
2441 | * Check if the current ops references the record. | |
2442 | * | |
2443 | * If the ops traces all functions, then it was already accounted for. | |
2444 | * If the ops does not trace the current record function, skip it. | |
2445 | * If the ops ignores the function via notrace filter, skip it. | |
2446 | */ | |
2447 | static inline bool | |
2448 | ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec) | |
2449 | { | |
2450 | /* If ops isn't enabled, ignore it */ | |
2451 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
2452 | return 0; | |
2453 | ||
2454 | /* If ops traces all mods, we already accounted for it */ | |
2455 | if (ops_traces_mod(ops)) | |
2456 | return 0; | |
2457 | ||
2458 | /* The function must be in the filter */ | |
2459 | if (!ftrace_hash_empty(ops->filter_hash) && | |
2460 | !ftrace_lookup_ip(ops->filter_hash, rec->ip)) | |
2461 | return 0; | |
f7bc8b61 | 2462 | |
8c4f3c3f SRRH |
2463 | /* If in notrace hash, we ignore it too */ |
2464 | if (ftrace_lookup_ip(ops->notrace_hash, rec->ip)) | |
2465 | return 0; | |
2466 | ||
2467 | return 1; | |
2468 | } | |
2469 | ||
2470 | static int referenced_filters(struct dyn_ftrace *rec) | |
2471 | { | |
2472 | struct ftrace_ops *ops; | |
2473 | int cnt = 0; | |
2474 | ||
2475 | for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) { | |
2476 | if (ops_references_rec(ops, rec)) | |
2477 | cnt++; | |
2478 | } | |
2479 | ||
2480 | return cnt; | |
f7bc8b61 SR |
2481 | } |
2482 | ||
1dc43cf0 | 2483 | static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs) |
3d083395 | 2484 | { |
85ae32ae | 2485 | struct ftrace_page *pg; |
e94142a6 | 2486 | struct dyn_ftrace *p; |
f22f9a89 | 2487 | cycle_t start, stop; |
1dc43cf0 | 2488 | unsigned long update_cnt = 0; |
f7bc8b61 | 2489 | unsigned long ref = 0; |
8c4f3c3f | 2490 | bool test = false; |
85ae32ae | 2491 | int i; |
f7bc8b61 SR |
2492 | |
2493 | /* | |
2494 | * When adding a module, we need to check if tracers are | |
2495 | * currently enabled and if they are set to trace all functions. | |
2496 | * If they are, we need to enable the module functions as well | |
2497 | * as update the reference counts for those function records. | |
2498 | */ | |
2499 | if (mod) { | |
2500 | struct ftrace_ops *ops; | |
2501 | ||
2502 | for (ops = ftrace_ops_list; | |
2503 | ops != &ftrace_list_end; ops = ops->next) { | |
8c4f3c3f SRRH |
2504 | if (ops->flags & FTRACE_OPS_FL_ENABLED) { |
2505 | if (ops_traces_mod(ops)) | |
2506 | ref++; | |
2507 | else | |
2508 | test = true; | |
2509 | } | |
f7bc8b61 SR |
2510 | } |
2511 | } | |
3d083395 | 2512 | |
750ed1a4 | 2513 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 | 2514 | |
1dc43cf0 | 2515 | for (pg = new_pgs; pg; pg = pg->next) { |
3d083395 | 2516 | |
85ae32ae | 2517 | for (i = 0; i < pg->index; i++) { |
8c4f3c3f SRRH |
2518 | int cnt = ref; |
2519 | ||
85ae32ae SR |
2520 | /* If something went wrong, bail without enabling anything */ |
2521 | if (unlikely(ftrace_disabled)) | |
2522 | return -1; | |
f22f9a89 | 2523 | |
85ae32ae | 2524 | p = &pg->records[i]; |
8c4f3c3f SRRH |
2525 | if (test) |
2526 | cnt += referenced_filters(p); | |
2527 | p->flags = cnt; | |
f22f9a89 | 2528 | |
85ae32ae SR |
2529 | /* |
2530 | * Do the initial record conversion from mcount jump | |
2531 | * to the NOP instructions. | |
2532 | */ | |
2533 | if (!ftrace_code_disable(mod, p)) | |
2534 | break; | |
5cb084bb | 2535 | |
1dc43cf0 | 2536 | update_cnt++; |
5cb084bb | 2537 | |
85ae32ae SR |
2538 | /* |
2539 | * If the tracing is enabled, go ahead and enable the record. | |
2540 | * | |
2541 | * The reason not to enable the record immediatelly is the | |
2542 | * inherent check of ftrace_make_nop/ftrace_make_call for | |
2543 | * correct previous instructions. Making first the NOP | |
2544 | * conversion puts the module to the correct state, thus | |
2545 | * passing the ftrace_make_call check. | |
2546 | */ | |
8c4f3c3f | 2547 | if (ftrace_start_up && cnt) { |
85ae32ae SR |
2548 | int failed = __ftrace_replace_code(p, 1); |
2549 | if (failed) | |
2550 | ftrace_bug(failed, p->ip); | |
2551 | } | |
5cb084bb | 2552 | } |
3d083395 SR |
2553 | } |
2554 | ||
750ed1a4 | 2555 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 | 2556 | ftrace_update_time = stop - start; |
1dc43cf0 | 2557 | ftrace_update_tot_cnt += update_cnt; |
3d083395 | 2558 | |
16444a8a ACM |
2559 | return 0; |
2560 | } | |
2561 | ||
a7900875 | 2562 | static int ftrace_allocate_records(struct ftrace_page *pg, int count) |
3c1720f0 | 2563 | { |
a7900875 | 2564 | int order; |
3c1720f0 | 2565 | int cnt; |
3c1720f0 | 2566 | |
a7900875 SR |
2567 | if (WARN_ON(!count)) |
2568 | return -EINVAL; | |
2569 | ||
2570 | order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE)); | |
3c1720f0 SR |
2571 | |
2572 | /* | |
a7900875 SR |
2573 | * We want to fill as much as possible. No more than a page |
2574 | * may be empty. | |
3c1720f0 | 2575 | */ |
a7900875 SR |
2576 | while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE) |
2577 | order--; | |
3c1720f0 | 2578 | |
a7900875 SR |
2579 | again: |
2580 | pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order); | |
3c1720f0 | 2581 | |
a7900875 SR |
2582 | if (!pg->records) { |
2583 | /* if we can't allocate this size, try something smaller */ | |
2584 | if (!order) | |
2585 | return -ENOMEM; | |
2586 | order >>= 1; | |
2587 | goto again; | |
2588 | } | |
3c1720f0 | 2589 | |
a7900875 SR |
2590 | cnt = (PAGE_SIZE << order) / ENTRY_SIZE; |
2591 | pg->size = cnt; | |
3c1720f0 | 2592 | |
a7900875 SR |
2593 | if (cnt > count) |
2594 | cnt = count; | |
2595 | ||
2596 | return cnt; | |
2597 | } | |
2598 | ||
2599 | static struct ftrace_page * | |
2600 | ftrace_allocate_pages(unsigned long num_to_init) | |
2601 | { | |
2602 | struct ftrace_page *start_pg; | |
2603 | struct ftrace_page *pg; | |
2604 | int order; | |
2605 | int cnt; | |
2606 | ||
2607 | if (!num_to_init) | |
2608 | return 0; | |
2609 | ||
2610 | start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL); | |
2611 | if (!pg) | |
2612 | return NULL; | |
2613 | ||
2614 | /* | |
2615 | * Try to allocate as much as possible in one continues | |
2616 | * location that fills in all of the space. We want to | |
2617 | * waste as little space as possible. | |
2618 | */ | |
2619 | for (;;) { | |
2620 | cnt = ftrace_allocate_records(pg, num_to_init); | |
2621 | if (cnt < 0) | |
2622 | goto free_pages; | |
2623 | ||
2624 | num_to_init -= cnt; | |
2625 | if (!num_to_init) | |
3c1720f0 SR |
2626 | break; |
2627 | ||
a7900875 SR |
2628 | pg->next = kzalloc(sizeof(*pg), GFP_KERNEL); |
2629 | if (!pg->next) | |
2630 | goto free_pages; | |
2631 | ||
3c1720f0 SR |
2632 | pg = pg->next; |
2633 | } | |
2634 | ||
a7900875 SR |
2635 | return start_pg; |
2636 | ||
2637 | free_pages: | |
1f61be00 NK |
2638 | pg = start_pg; |
2639 | while (pg) { | |
a7900875 SR |
2640 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
2641 | free_pages((unsigned long)pg->records, order); | |
2642 | start_pg = pg->next; | |
2643 | kfree(pg); | |
2644 | pg = start_pg; | |
2645 | } | |
2646 | pr_info("ftrace: FAILED to allocate memory for functions\n"); | |
2647 | return NULL; | |
2648 | } | |
2649 | ||
5072c59f SR |
2650 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ |
2651 | ||
2652 | struct ftrace_iterator { | |
98c4fd04 | 2653 | loff_t pos; |
4aeb6967 SR |
2654 | loff_t func_pos; |
2655 | struct ftrace_page *pg; | |
2656 | struct dyn_ftrace *func; | |
2657 | struct ftrace_func_probe *probe; | |
2658 | struct trace_parser parser; | |
1cf41dd7 | 2659 | struct ftrace_hash *hash; |
33dc9b12 | 2660 | struct ftrace_ops *ops; |
4aeb6967 SR |
2661 | int hidx; |
2662 | int idx; | |
2663 | unsigned flags; | |
5072c59f SR |
2664 | }; |
2665 | ||
8fc0c701 | 2666 | static void * |
4aeb6967 | 2667 | t_hash_next(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
2668 | { |
2669 | struct ftrace_iterator *iter = m->private; | |
4aeb6967 | 2670 | struct hlist_node *hnd = NULL; |
8fc0c701 SR |
2671 | struct hlist_head *hhd; |
2672 | ||
8fc0c701 | 2673 | (*pos)++; |
98c4fd04 | 2674 | iter->pos = *pos; |
8fc0c701 | 2675 | |
4aeb6967 SR |
2676 | if (iter->probe) |
2677 | hnd = &iter->probe->node; | |
8fc0c701 SR |
2678 | retry: |
2679 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
2680 | return NULL; | |
2681 | ||
2682 | hhd = &ftrace_func_hash[iter->hidx]; | |
2683 | ||
2684 | if (hlist_empty(hhd)) { | |
2685 | iter->hidx++; | |
2686 | hnd = NULL; | |
2687 | goto retry; | |
2688 | } | |
2689 | ||
2690 | if (!hnd) | |
2691 | hnd = hhd->first; | |
2692 | else { | |
2693 | hnd = hnd->next; | |
2694 | if (!hnd) { | |
2695 | iter->hidx++; | |
2696 | goto retry; | |
2697 | } | |
2698 | } | |
2699 | ||
4aeb6967 SR |
2700 | if (WARN_ON_ONCE(!hnd)) |
2701 | return NULL; | |
2702 | ||
2703 | iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node); | |
2704 | ||
2705 | return iter; | |
8fc0c701 SR |
2706 | } |
2707 | ||
2708 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
2709 | { | |
2710 | struct ftrace_iterator *iter = m->private; | |
2711 | void *p = NULL; | |
d82d6244 LZ |
2712 | loff_t l; |
2713 | ||
69a3083c SR |
2714 | if (!(iter->flags & FTRACE_ITER_DO_HASH)) |
2715 | return NULL; | |
2716 | ||
2bccfffd SR |
2717 | if (iter->func_pos > *pos) |
2718 | return NULL; | |
8fc0c701 | 2719 | |
d82d6244 | 2720 | iter->hidx = 0; |
2bccfffd | 2721 | for (l = 0; l <= (*pos - iter->func_pos); ) { |
4aeb6967 | 2722 | p = t_hash_next(m, &l); |
d82d6244 LZ |
2723 | if (!p) |
2724 | break; | |
2725 | } | |
4aeb6967 SR |
2726 | if (!p) |
2727 | return NULL; | |
2728 | ||
98c4fd04 SR |
2729 | /* Only set this if we have an item */ |
2730 | iter->flags |= FTRACE_ITER_HASH; | |
2731 | ||
4aeb6967 | 2732 | return iter; |
8fc0c701 SR |
2733 | } |
2734 | ||
4aeb6967 SR |
2735 | static int |
2736 | t_hash_show(struct seq_file *m, struct ftrace_iterator *iter) | |
8fc0c701 | 2737 | { |
b6887d79 | 2738 | struct ftrace_func_probe *rec; |
8fc0c701 | 2739 | |
4aeb6967 SR |
2740 | rec = iter->probe; |
2741 | if (WARN_ON_ONCE(!rec)) | |
2742 | return -EIO; | |
8fc0c701 | 2743 | |
809dcf29 SR |
2744 | if (rec->ops->print) |
2745 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
2746 | ||
b375a11a | 2747 | seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func); |
8fc0c701 SR |
2748 | |
2749 | if (rec->data) | |
2750 | seq_printf(m, ":%p", rec->data); | |
2751 | seq_putc(m, '\n'); | |
2752 | ||
2753 | return 0; | |
2754 | } | |
2755 | ||
e309b41d | 2756 | static void * |
5072c59f SR |
2757 | t_next(struct seq_file *m, void *v, loff_t *pos) |
2758 | { | |
2759 | struct ftrace_iterator *iter = m->private; | |
fc13cb0c | 2760 | struct ftrace_ops *ops = iter->ops; |
5072c59f SR |
2761 | struct dyn_ftrace *rec = NULL; |
2762 | ||
45a4a237 SR |
2763 | if (unlikely(ftrace_disabled)) |
2764 | return NULL; | |
2765 | ||
8fc0c701 | 2766 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 2767 | return t_hash_next(m, pos); |
8fc0c701 | 2768 | |
5072c59f | 2769 | (*pos)++; |
1106b699 | 2770 | iter->pos = iter->func_pos = *pos; |
5072c59f | 2771 | |
0c75a3ed | 2772 | if (iter->flags & FTRACE_ITER_PRINTALL) |
57c072c7 | 2773 | return t_hash_start(m, pos); |
0c75a3ed | 2774 | |
5072c59f SR |
2775 | retry: |
2776 | if (iter->idx >= iter->pg->index) { | |
2777 | if (iter->pg->next) { | |
2778 | iter->pg = iter->pg->next; | |
2779 | iter->idx = 0; | |
2780 | goto retry; | |
2781 | } | |
2782 | } else { | |
2783 | rec = &iter->pg->records[iter->idx++]; | |
32082309 | 2784 | if (((iter->flags & FTRACE_ITER_FILTER) && |
f45948e8 | 2785 | !(ftrace_lookup_ip(ops->filter_hash, rec->ip))) || |
0183fb1c | 2786 | |
41c52c0d | 2787 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
647bcd03 SR |
2788 | !ftrace_lookup_ip(ops->notrace_hash, rec->ip)) || |
2789 | ||
2790 | ((iter->flags & FTRACE_ITER_ENABLED) && | |
23ea9c4d | 2791 | !(rec->flags & FTRACE_FL_ENABLED))) { |
647bcd03 | 2792 | |
5072c59f SR |
2793 | rec = NULL; |
2794 | goto retry; | |
2795 | } | |
2796 | } | |
2797 | ||
4aeb6967 | 2798 | if (!rec) |
57c072c7 | 2799 | return t_hash_start(m, pos); |
4aeb6967 SR |
2800 | |
2801 | iter->func = rec; | |
2802 | ||
2803 | return iter; | |
5072c59f SR |
2804 | } |
2805 | ||
98c4fd04 SR |
2806 | static void reset_iter_read(struct ftrace_iterator *iter) |
2807 | { | |
2808 | iter->pos = 0; | |
2809 | iter->func_pos = 0; | |
70f77b3f | 2810 | iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_HASH); |
5072c59f SR |
2811 | } |
2812 | ||
2813 | static void *t_start(struct seq_file *m, loff_t *pos) | |
2814 | { | |
2815 | struct ftrace_iterator *iter = m->private; | |
fc13cb0c | 2816 | struct ftrace_ops *ops = iter->ops; |
5072c59f | 2817 | void *p = NULL; |
694ce0a5 | 2818 | loff_t l; |
5072c59f | 2819 | |
8fc0c701 | 2820 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
2821 | |
2822 | if (unlikely(ftrace_disabled)) | |
2823 | return NULL; | |
2824 | ||
98c4fd04 SR |
2825 | /* |
2826 | * If an lseek was done, then reset and start from beginning. | |
2827 | */ | |
2828 | if (*pos < iter->pos) | |
2829 | reset_iter_read(iter); | |
2830 | ||
0c75a3ed SR |
2831 | /* |
2832 | * For set_ftrace_filter reading, if we have the filter | |
2833 | * off, we can short cut and just print out that all | |
2834 | * functions are enabled. | |
2835 | */ | |
8c006cf7 NK |
2836 | if ((iter->flags & FTRACE_ITER_FILTER && |
2837 | ftrace_hash_empty(ops->filter_hash)) || | |
2838 | (iter->flags & FTRACE_ITER_NOTRACE && | |
2839 | ftrace_hash_empty(ops->notrace_hash))) { | |
0c75a3ed | 2840 | if (*pos > 0) |
8fc0c701 | 2841 | return t_hash_start(m, pos); |
0c75a3ed | 2842 | iter->flags |= FTRACE_ITER_PRINTALL; |
df091625 CW |
2843 | /* reset in case of seek/pread */ |
2844 | iter->flags &= ~FTRACE_ITER_HASH; | |
0c75a3ed SR |
2845 | return iter; |
2846 | } | |
2847 | ||
8fc0c701 SR |
2848 | if (iter->flags & FTRACE_ITER_HASH) |
2849 | return t_hash_start(m, pos); | |
2850 | ||
98c4fd04 SR |
2851 | /* |
2852 | * Unfortunately, we need to restart at ftrace_pages_start | |
2853 | * every time we let go of the ftrace_mutex. This is because | |
2854 | * those pointers can change without the lock. | |
2855 | */ | |
694ce0a5 LZ |
2856 | iter->pg = ftrace_pages_start; |
2857 | iter->idx = 0; | |
2858 | for (l = 0; l <= *pos; ) { | |
2859 | p = t_next(m, p, &l); | |
2860 | if (!p) | |
2861 | break; | |
50cdaf08 | 2862 | } |
5821e1b7 | 2863 | |
69a3083c SR |
2864 | if (!p) |
2865 | return t_hash_start(m, pos); | |
4aeb6967 SR |
2866 | |
2867 | return iter; | |
5072c59f SR |
2868 | } |
2869 | ||
2870 | static void t_stop(struct seq_file *m, void *p) | |
2871 | { | |
8fc0c701 | 2872 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
2873 | } |
2874 | ||
2875 | static int t_show(struct seq_file *m, void *v) | |
2876 | { | |
0c75a3ed | 2877 | struct ftrace_iterator *iter = m->private; |
4aeb6967 | 2878 | struct dyn_ftrace *rec; |
5072c59f | 2879 | |
8fc0c701 | 2880 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 2881 | return t_hash_show(m, iter); |
8fc0c701 | 2882 | |
0c75a3ed | 2883 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
8c006cf7 NK |
2884 | if (iter->flags & FTRACE_ITER_NOTRACE) |
2885 | seq_printf(m, "#### no functions disabled ####\n"); | |
2886 | else | |
2887 | seq_printf(m, "#### all functions enabled ####\n"); | |
0c75a3ed SR |
2888 | return 0; |
2889 | } | |
2890 | ||
4aeb6967 SR |
2891 | rec = iter->func; |
2892 | ||
5072c59f SR |
2893 | if (!rec) |
2894 | return 0; | |
2895 | ||
647bcd03 | 2896 | seq_printf(m, "%ps", (void *)rec->ip); |
9674b2fa | 2897 | if (iter->flags & FTRACE_ITER_ENABLED) { |
08f6fba5 | 2898 | seq_printf(m, " (%ld)%s", |
0376bde1 | 2899 | ftrace_rec_count(rec), |
9674b2fa SRRH |
2900 | rec->flags & FTRACE_FL_REGS ? " R" : " "); |
2901 | if (rec->flags & FTRACE_FL_TRAMP_EN) { | |
2902 | struct ftrace_ops *ops; | |
2903 | ||
2904 | ops = ftrace_find_tramp_ops_curr(rec); | |
2905 | if (ops && ops->trampoline) | |
2906 | seq_printf(m, "\ttramp: %pS", | |
2907 | (void *)ops->trampoline); | |
2908 | else | |
2909 | seq_printf(m, "\ttramp: ERROR!"); | |
2910 | } | |
2911 | } | |
2912 | ||
647bcd03 | 2913 | seq_printf(m, "\n"); |
5072c59f SR |
2914 | |
2915 | return 0; | |
2916 | } | |
2917 | ||
88e9d34c | 2918 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
2919 | .start = t_start, |
2920 | .next = t_next, | |
2921 | .stop = t_stop, | |
2922 | .show = t_show, | |
2923 | }; | |
2924 | ||
e309b41d | 2925 | static int |
5072c59f SR |
2926 | ftrace_avail_open(struct inode *inode, struct file *file) |
2927 | { | |
2928 | struct ftrace_iterator *iter; | |
5072c59f | 2929 | |
4eebcc81 SR |
2930 | if (unlikely(ftrace_disabled)) |
2931 | return -ENODEV; | |
2932 | ||
50e18b94 JO |
2933 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
2934 | if (iter) { | |
2935 | iter->pg = ftrace_pages_start; | |
2936 | iter->ops = &global_ops; | |
4bf39a94 | 2937 | } |
5072c59f | 2938 | |
50e18b94 | 2939 | return iter ? 0 : -ENOMEM; |
5072c59f SR |
2940 | } |
2941 | ||
647bcd03 SR |
2942 | static int |
2943 | ftrace_enabled_open(struct inode *inode, struct file *file) | |
2944 | { | |
2945 | struct ftrace_iterator *iter; | |
647bcd03 SR |
2946 | |
2947 | if (unlikely(ftrace_disabled)) | |
2948 | return -ENODEV; | |
2949 | ||
50e18b94 JO |
2950 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
2951 | if (iter) { | |
2952 | iter->pg = ftrace_pages_start; | |
2953 | iter->flags = FTRACE_ITER_ENABLED; | |
2954 | iter->ops = &global_ops; | |
647bcd03 SR |
2955 | } |
2956 | ||
50e18b94 | 2957 | return iter ? 0 : -ENOMEM; |
647bcd03 SR |
2958 | } |
2959 | ||
fc13cb0c SR |
2960 | /** |
2961 | * ftrace_regex_open - initialize function tracer filter files | |
2962 | * @ops: The ftrace_ops that hold the hash filters | |
2963 | * @flag: The type of filter to process | |
2964 | * @inode: The inode, usually passed in to your open routine | |
2965 | * @file: The file, usually passed in to your open routine | |
2966 | * | |
2967 | * ftrace_regex_open() initializes the filter files for the | |
2968 | * @ops. Depending on @flag it may process the filter hash or | |
2969 | * the notrace hash of @ops. With this called from the open | |
2970 | * routine, you can use ftrace_filter_write() for the write | |
2971 | * routine if @flag has FTRACE_ITER_FILTER set, or | |
2972 | * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set. | |
098c879e | 2973 | * tracing_lseek() should be used as the lseek routine, and |
fc13cb0c SR |
2974 | * release must call ftrace_regex_release(). |
2975 | */ | |
2976 | int | |
f45948e8 | 2977 | ftrace_regex_open(struct ftrace_ops *ops, int flag, |
1cf41dd7 | 2978 | struct inode *inode, struct file *file) |
5072c59f SR |
2979 | { |
2980 | struct ftrace_iterator *iter; | |
f45948e8 | 2981 | struct ftrace_hash *hash; |
5072c59f SR |
2982 | int ret = 0; |
2983 | ||
f04f24fb MH |
2984 | ftrace_ops_init(ops); |
2985 | ||
4eebcc81 SR |
2986 | if (unlikely(ftrace_disabled)) |
2987 | return -ENODEV; | |
2988 | ||
5072c59f SR |
2989 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
2990 | if (!iter) | |
2991 | return -ENOMEM; | |
2992 | ||
689fd8b6 | 2993 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) { |
2994 | kfree(iter); | |
2995 | return -ENOMEM; | |
2996 | } | |
2997 | ||
3f2367ba MH |
2998 | iter->ops = ops; |
2999 | iter->flags = flag; | |
3000 | ||
3001 | mutex_lock(&ops->regex_lock); | |
3002 | ||
f45948e8 SR |
3003 | if (flag & FTRACE_ITER_NOTRACE) |
3004 | hash = ops->notrace_hash; | |
3005 | else | |
3006 | hash = ops->filter_hash; | |
3007 | ||
33dc9b12 | 3008 | if (file->f_mode & FMODE_WRITE) { |
ef2fbe16 NK |
3009 | const int size_bits = FTRACE_HASH_DEFAULT_BITS; |
3010 | ||
3011 | if (file->f_flags & O_TRUNC) | |
3012 | iter->hash = alloc_ftrace_hash(size_bits); | |
3013 | else | |
3014 | iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash); | |
3015 | ||
33dc9b12 SR |
3016 | if (!iter->hash) { |
3017 | trace_parser_put(&iter->parser); | |
3018 | kfree(iter); | |
3f2367ba MH |
3019 | ret = -ENOMEM; |
3020 | goto out_unlock; | |
33dc9b12 SR |
3021 | } |
3022 | } | |
1cf41dd7 | 3023 | |
5072c59f SR |
3024 | if (file->f_mode & FMODE_READ) { |
3025 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
3026 | |
3027 | ret = seq_open(file, &show_ftrace_seq_ops); | |
3028 | if (!ret) { | |
3029 | struct seq_file *m = file->private_data; | |
3030 | m->private = iter; | |
79fe249c | 3031 | } else { |
33dc9b12 SR |
3032 | /* Failed */ |
3033 | free_ftrace_hash(iter->hash); | |
79fe249c | 3034 | trace_parser_put(&iter->parser); |
5072c59f | 3035 | kfree(iter); |
79fe249c | 3036 | } |
5072c59f SR |
3037 | } else |
3038 | file->private_data = iter; | |
3f2367ba MH |
3039 | |
3040 | out_unlock: | |
f04f24fb | 3041 | mutex_unlock(&ops->regex_lock); |
5072c59f SR |
3042 | |
3043 | return ret; | |
3044 | } | |
3045 | ||
41c52c0d SR |
3046 | static int |
3047 | ftrace_filter_open(struct inode *inode, struct file *file) | |
3048 | { | |
e3b3e2e8 SRRH |
3049 | struct ftrace_ops *ops = inode->i_private; |
3050 | ||
3051 | return ftrace_regex_open(ops, | |
69a3083c SR |
3052 | FTRACE_ITER_FILTER | FTRACE_ITER_DO_HASH, |
3053 | inode, file); | |
41c52c0d SR |
3054 | } |
3055 | ||
3056 | static int | |
3057 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
3058 | { | |
e3b3e2e8 SRRH |
3059 | struct ftrace_ops *ops = inode->i_private; |
3060 | ||
3061 | return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE, | |
1cf41dd7 | 3062 | inode, file); |
41c52c0d SR |
3063 | } |
3064 | ||
64e7c440 | 3065 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 3066 | { |
9f4801e3 | 3067 | int matched = 0; |
751e9983 | 3068 | int slen; |
9f4801e3 | 3069 | |
9f4801e3 SR |
3070 | switch (type) { |
3071 | case MATCH_FULL: | |
3072 | if (strcmp(str, regex) == 0) | |
3073 | matched = 1; | |
3074 | break; | |
3075 | case MATCH_FRONT_ONLY: | |
3076 | if (strncmp(str, regex, len) == 0) | |
3077 | matched = 1; | |
3078 | break; | |
3079 | case MATCH_MIDDLE_ONLY: | |
3080 | if (strstr(str, regex)) | |
3081 | matched = 1; | |
3082 | break; | |
3083 | case MATCH_END_ONLY: | |
751e9983 LZ |
3084 | slen = strlen(str); |
3085 | if (slen >= len && memcmp(str + slen - len, regex, len) == 0) | |
9f4801e3 SR |
3086 | matched = 1; |
3087 | break; | |
3088 | } | |
3089 | ||
3090 | return matched; | |
3091 | } | |
3092 | ||
b448c4e3 | 3093 | static int |
1cf41dd7 | 3094 | enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not) |
996e87be | 3095 | { |
b448c4e3 | 3096 | struct ftrace_func_entry *entry; |
b448c4e3 SR |
3097 | int ret = 0; |
3098 | ||
1cf41dd7 SR |
3099 | entry = ftrace_lookup_ip(hash, rec->ip); |
3100 | if (not) { | |
3101 | /* Do nothing if it doesn't exist */ | |
3102 | if (!entry) | |
3103 | return 0; | |
b448c4e3 | 3104 | |
33dc9b12 | 3105 | free_hash_entry(hash, entry); |
1cf41dd7 SR |
3106 | } else { |
3107 | /* Do nothing if it exists */ | |
3108 | if (entry) | |
3109 | return 0; | |
b448c4e3 | 3110 | |
1cf41dd7 | 3111 | ret = add_hash_entry(hash, rec->ip); |
b448c4e3 SR |
3112 | } |
3113 | return ret; | |
996e87be SR |
3114 | } |
3115 | ||
64e7c440 | 3116 | static int |
b9df92d2 SR |
3117 | ftrace_match_record(struct dyn_ftrace *rec, char *mod, |
3118 | char *regex, int len, int type) | |
64e7c440 SR |
3119 | { |
3120 | char str[KSYM_SYMBOL_LEN]; | |
b9df92d2 SR |
3121 | char *modname; |
3122 | ||
3123 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
3124 | ||
3125 | if (mod) { | |
3126 | /* module lookup requires matching the module */ | |
3127 | if (!modname || strcmp(modname, mod)) | |
3128 | return 0; | |
3129 | ||
3130 | /* blank search means to match all funcs in the mod */ | |
3131 | if (!len) | |
3132 | return 1; | |
3133 | } | |
64e7c440 | 3134 | |
64e7c440 SR |
3135 | return ftrace_match(str, regex, len, type); |
3136 | } | |
3137 | ||
1cf41dd7 SR |
3138 | static int |
3139 | match_records(struct ftrace_hash *hash, char *buff, | |
3140 | int len, char *mod, int not) | |
9f4801e3 | 3141 | { |
b9df92d2 | 3142 | unsigned search_len = 0; |
9f4801e3 SR |
3143 | struct ftrace_page *pg; |
3144 | struct dyn_ftrace *rec; | |
b9df92d2 SR |
3145 | int type = MATCH_FULL; |
3146 | char *search = buff; | |
311d16da | 3147 | int found = 0; |
b448c4e3 | 3148 | int ret; |
9f4801e3 | 3149 | |
b9df92d2 SR |
3150 | if (len) { |
3151 | type = filter_parse_regex(buff, len, &search, ¬); | |
3152 | search_len = strlen(search); | |
3153 | } | |
9f4801e3 | 3154 | |
52baf119 | 3155 | mutex_lock(&ftrace_lock); |
265c831c | 3156 | |
b9df92d2 SR |
3157 | if (unlikely(ftrace_disabled)) |
3158 | goto out_unlock; | |
9f4801e3 | 3159 | |
265c831c | 3160 | do_for_each_ftrace_rec(pg, rec) { |
b9df92d2 | 3161 | if (ftrace_match_record(rec, mod, search, search_len, type)) { |
1cf41dd7 | 3162 | ret = enter_record(hash, rec, not); |
b448c4e3 SR |
3163 | if (ret < 0) { |
3164 | found = ret; | |
3165 | goto out_unlock; | |
3166 | } | |
311d16da | 3167 | found = 1; |
265c831c SR |
3168 | } |
3169 | } while_for_each_ftrace_rec(); | |
b9df92d2 | 3170 | out_unlock: |
52baf119 | 3171 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
3172 | |
3173 | return found; | |
5072c59f SR |
3174 | } |
3175 | ||
64e7c440 | 3176 | static int |
1cf41dd7 | 3177 | ftrace_match_records(struct ftrace_hash *hash, char *buff, int len) |
64e7c440 | 3178 | { |
1cf41dd7 | 3179 | return match_records(hash, buff, len, NULL, 0); |
64e7c440 SR |
3180 | } |
3181 | ||
1cf41dd7 SR |
3182 | static int |
3183 | ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod) | |
64e7c440 | 3184 | { |
64e7c440 | 3185 | int not = 0; |
6a24a244 | 3186 | |
64e7c440 SR |
3187 | /* blank or '*' mean the same */ |
3188 | if (strcmp(buff, "*") == 0) | |
3189 | buff[0] = 0; | |
3190 | ||
3191 | /* handle the case of 'dont filter this module' */ | |
3192 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
3193 | buff[0] = 0; | |
3194 | not = 1; | |
3195 | } | |
3196 | ||
1cf41dd7 | 3197 | return match_records(hash, buff, strlen(buff), mod, not); |
64e7c440 SR |
3198 | } |
3199 | ||
f6180773 SR |
3200 | /* |
3201 | * We register the module command as a template to show others how | |
3202 | * to register the a command as well. | |
3203 | */ | |
3204 | ||
3205 | static int | |
43dd61c9 SR |
3206 | ftrace_mod_callback(struct ftrace_hash *hash, |
3207 | char *func, char *cmd, char *param, int enable) | |
f6180773 SR |
3208 | { |
3209 | char *mod; | |
b448c4e3 | 3210 | int ret = -EINVAL; |
f6180773 SR |
3211 | |
3212 | /* | |
3213 | * cmd == 'mod' because we only registered this func | |
3214 | * for the 'mod' ftrace_func_command. | |
3215 | * But if you register one func with multiple commands, | |
3216 | * you can tell which command was used by the cmd | |
3217 | * parameter. | |
3218 | */ | |
3219 | ||
3220 | /* we must have a module name */ | |
3221 | if (!param) | |
b448c4e3 | 3222 | return ret; |
f6180773 SR |
3223 | |
3224 | mod = strsep(¶m, ":"); | |
3225 | if (!strlen(mod)) | |
b448c4e3 | 3226 | return ret; |
f6180773 | 3227 | |
1cf41dd7 | 3228 | ret = ftrace_match_module_records(hash, func, mod); |
b448c4e3 SR |
3229 | if (!ret) |
3230 | ret = -EINVAL; | |
3231 | if (ret < 0) | |
3232 | return ret; | |
3233 | ||
3234 | return 0; | |
f6180773 SR |
3235 | } |
3236 | ||
3237 | static struct ftrace_func_command ftrace_mod_cmd = { | |
3238 | .name = "mod", | |
3239 | .func = ftrace_mod_callback, | |
3240 | }; | |
3241 | ||
3242 | static int __init ftrace_mod_cmd_init(void) | |
3243 | { | |
3244 | return register_ftrace_command(&ftrace_mod_cmd); | |
3245 | } | |
6f415672 | 3246 | core_initcall(ftrace_mod_cmd_init); |
f6180773 | 3247 | |
2f5f6ad9 | 3248 | static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 3249 | struct ftrace_ops *op, struct pt_regs *pt_regs) |
59df055f | 3250 | { |
b6887d79 | 3251 | struct ftrace_func_probe *entry; |
59df055f | 3252 | struct hlist_head *hhd; |
59df055f | 3253 | unsigned long key; |
59df055f SR |
3254 | |
3255 | key = hash_long(ip, FTRACE_HASH_BITS); | |
3256 | ||
3257 | hhd = &ftrace_func_hash[key]; | |
3258 | ||
3259 | if (hlist_empty(hhd)) | |
3260 | return; | |
3261 | ||
3262 | /* | |
3263 | * Disable preemption for these calls to prevent a RCU grace | |
3264 | * period. This syncs the hash iteration and freeing of items | |
3265 | * on the hash. rcu_read_lock is too dangerous here. | |
3266 | */ | |
5168ae50 | 3267 | preempt_disable_notrace(); |
1bb539ca | 3268 | hlist_for_each_entry_rcu_notrace(entry, hhd, node) { |
59df055f SR |
3269 | if (entry->ip == ip) |
3270 | entry->ops->func(ip, parent_ip, &entry->data); | |
3271 | } | |
5168ae50 | 3272 | preempt_enable_notrace(); |
59df055f SR |
3273 | } |
3274 | ||
b6887d79 | 3275 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 3276 | { |
fb9fb015 | 3277 | .func = function_trace_probe_call, |
f04f24fb MH |
3278 | .flags = FTRACE_OPS_FL_INITIALIZED, |
3279 | INIT_REGEX_LOCK(trace_probe_ops) | |
59df055f SR |
3280 | }; |
3281 | ||
b6887d79 | 3282 | static int ftrace_probe_registered; |
59df055f | 3283 | |
b6887d79 | 3284 | static void __enable_ftrace_function_probe(void) |
59df055f | 3285 | { |
b848914c | 3286 | int ret; |
59df055f SR |
3287 | int i; |
3288 | ||
19dd603e SRRH |
3289 | if (ftrace_probe_registered) { |
3290 | /* still need to update the function call sites */ | |
3291 | if (ftrace_enabled) | |
3292 | ftrace_run_update_code(FTRACE_UPDATE_CALLS); | |
59df055f | 3293 | return; |
19dd603e | 3294 | } |
59df055f SR |
3295 | |
3296 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
3297 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
3298 | if (hhd->first) | |
3299 | break; | |
3300 | } | |
3301 | /* Nothing registered? */ | |
3302 | if (i == FTRACE_FUNC_HASHSIZE) | |
3303 | return; | |
3304 | ||
8a56d776 | 3305 | ret = ftrace_startup(&trace_probe_ops, 0); |
b848914c | 3306 | |
b6887d79 | 3307 | ftrace_probe_registered = 1; |
59df055f SR |
3308 | } |
3309 | ||
b6887d79 | 3310 | static void __disable_ftrace_function_probe(void) |
59df055f SR |
3311 | { |
3312 | int i; | |
3313 | ||
b6887d79 | 3314 | if (!ftrace_probe_registered) |
59df055f SR |
3315 | return; |
3316 | ||
3317 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
3318 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
3319 | if (hhd->first) | |
3320 | return; | |
3321 | } | |
3322 | ||
3323 | /* no more funcs left */ | |
8a56d776 | 3324 | ftrace_shutdown(&trace_probe_ops, 0); |
b848914c | 3325 | |
b6887d79 | 3326 | ftrace_probe_registered = 0; |
59df055f SR |
3327 | } |
3328 | ||
3329 | ||
7818b388 | 3330 | static void ftrace_free_entry(struct ftrace_func_probe *entry) |
59df055f | 3331 | { |
59df055f | 3332 | if (entry->ops->free) |
e67efb93 | 3333 | entry->ops->free(entry->ops, entry->ip, &entry->data); |
59df055f SR |
3334 | kfree(entry); |
3335 | } | |
3336 | ||
59df055f | 3337 | int |
b6887d79 | 3338 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3339 | void *data) |
3340 | { | |
b6887d79 | 3341 | struct ftrace_func_probe *entry; |
e1df4cb6 SRRH |
3342 | struct ftrace_hash **orig_hash = &trace_probe_ops.filter_hash; |
3343 | struct ftrace_hash *hash; | |
59df055f SR |
3344 | struct ftrace_page *pg; |
3345 | struct dyn_ftrace *rec; | |
59df055f | 3346 | int type, len, not; |
6a24a244 | 3347 | unsigned long key; |
59df055f SR |
3348 | int count = 0; |
3349 | char *search; | |
e1df4cb6 | 3350 | int ret; |
59df055f | 3351 | |
3f6fe06d | 3352 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
3353 | len = strlen(search); |
3354 | ||
b6887d79 | 3355 | /* we do not support '!' for function probes */ |
59df055f SR |
3356 | if (WARN_ON(not)) |
3357 | return -EINVAL; | |
3358 | ||
3f2367ba | 3359 | mutex_lock(&trace_probe_ops.regex_lock); |
59df055f | 3360 | |
e1df4cb6 SRRH |
3361 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); |
3362 | if (!hash) { | |
3363 | count = -ENOMEM; | |
5ae0bf59 | 3364 | goto out; |
e1df4cb6 SRRH |
3365 | } |
3366 | ||
3367 | if (unlikely(ftrace_disabled)) { | |
3368 | count = -ENODEV; | |
5ae0bf59 | 3369 | goto out; |
e1df4cb6 | 3370 | } |
59df055f | 3371 | |
5ae0bf59 SRRH |
3372 | mutex_lock(&ftrace_lock); |
3373 | ||
45a4a237 | 3374 | do_for_each_ftrace_rec(pg, rec) { |
59df055f | 3375 | |
b9df92d2 | 3376 | if (!ftrace_match_record(rec, NULL, search, len, type)) |
59df055f SR |
3377 | continue; |
3378 | ||
3379 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
3380 | if (!entry) { | |
b6887d79 | 3381 | /* If we did not process any, then return error */ |
59df055f SR |
3382 | if (!count) |
3383 | count = -ENOMEM; | |
3384 | goto out_unlock; | |
3385 | } | |
3386 | ||
3387 | count++; | |
3388 | ||
3389 | entry->data = data; | |
3390 | ||
3391 | /* | |
3392 | * The caller might want to do something special | |
3393 | * for each function we find. We call the callback | |
3394 | * to give the caller an opportunity to do so. | |
3395 | */ | |
e67efb93 SRRH |
3396 | if (ops->init) { |
3397 | if (ops->init(ops, rec->ip, &entry->data) < 0) { | |
59df055f SR |
3398 | /* caller does not like this func */ |
3399 | kfree(entry); | |
3400 | continue; | |
3401 | } | |
3402 | } | |
3403 | ||
e1df4cb6 SRRH |
3404 | ret = enter_record(hash, rec, 0); |
3405 | if (ret < 0) { | |
3406 | kfree(entry); | |
3407 | count = ret; | |
3408 | goto out_unlock; | |
3409 | } | |
3410 | ||
59df055f SR |
3411 | entry->ops = ops; |
3412 | entry->ip = rec->ip; | |
3413 | ||
3414 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
3415 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
3416 | ||
3417 | } while_for_each_ftrace_rec(); | |
e1df4cb6 SRRH |
3418 | |
3419 | ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash); | |
3420 | if (ret < 0) | |
3421 | count = ret; | |
3422 | ||
b6887d79 | 3423 | __enable_ftrace_function_probe(); |
59df055f SR |
3424 | |
3425 | out_unlock: | |
5ae0bf59 SRRH |
3426 | mutex_unlock(&ftrace_lock); |
3427 | out: | |
3f2367ba | 3428 | mutex_unlock(&trace_probe_ops.regex_lock); |
e1df4cb6 | 3429 | free_ftrace_hash(hash); |
59df055f SR |
3430 | |
3431 | return count; | |
3432 | } | |
3433 | ||
3434 | enum { | |
b6887d79 SR |
3435 | PROBE_TEST_FUNC = 1, |
3436 | PROBE_TEST_DATA = 2 | |
59df055f SR |
3437 | }; |
3438 | ||
3439 | static void | |
b6887d79 | 3440 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3441 | void *data, int flags) |
3442 | { | |
e1df4cb6 | 3443 | struct ftrace_func_entry *rec_entry; |
b6887d79 | 3444 | struct ftrace_func_probe *entry; |
7818b388 | 3445 | struct ftrace_func_probe *p; |
e1df4cb6 | 3446 | struct ftrace_hash **orig_hash = &trace_probe_ops.filter_hash; |
7818b388 | 3447 | struct list_head free_list; |
e1df4cb6 | 3448 | struct ftrace_hash *hash; |
b67bfe0d | 3449 | struct hlist_node *tmp; |
59df055f SR |
3450 | char str[KSYM_SYMBOL_LEN]; |
3451 | int type = MATCH_FULL; | |
3452 | int i, len = 0; | |
3453 | char *search; | |
3454 | ||
b36461da | 3455 | if (glob && (strcmp(glob, "*") == 0 || !strlen(glob))) |
59df055f | 3456 | glob = NULL; |
b36461da | 3457 | else if (glob) { |
59df055f SR |
3458 | int not; |
3459 | ||
3f6fe06d | 3460 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
3461 | len = strlen(search); |
3462 | ||
b6887d79 | 3463 | /* we do not support '!' for function probes */ |
59df055f SR |
3464 | if (WARN_ON(not)) |
3465 | return; | |
3466 | } | |
3467 | ||
3f2367ba | 3468 | mutex_lock(&trace_probe_ops.regex_lock); |
e1df4cb6 SRRH |
3469 | |
3470 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
3471 | if (!hash) | |
3472 | /* Hmm, should report this somehow */ | |
3473 | goto out_unlock; | |
3474 | ||
7818b388 SRRH |
3475 | INIT_LIST_HEAD(&free_list); |
3476 | ||
59df055f SR |
3477 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { |
3478 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
3479 | ||
b67bfe0d | 3480 | hlist_for_each_entry_safe(entry, tmp, hhd, node) { |
59df055f SR |
3481 | |
3482 | /* break up if statements for readability */ | |
b6887d79 | 3483 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
3484 | continue; |
3485 | ||
b6887d79 | 3486 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
3487 | continue; |
3488 | ||
3489 | /* do this last, since it is the most expensive */ | |
3490 | if (glob) { | |
3491 | kallsyms_lookup(entry->ip, NULL, NULL, | |
3492 | NULL, str); | |
3493 | if (!ftrace_match(str, glob, len, type)) | |
3494 | continue; | |
3495 | } | |
3496 | ||
e1df4cb6 SRRH |
3497 | rec_entry = ftrace_lookup_ip(hash, entry->ip); |
3498 | /* It is possible more than one entry had this ip */ | |
3499 | if (rec_entry) | |
3500 | free_hash_entry(hash, rec_entry); | |
3501 | ||
740466bc | 3502 | hlist_del_rcu(&entry->node); |
7818b388 | 3503 | list_add(&entry->free_list, &free_list); |
59df055f SR |
3504 | } |
3505 | } | |
3f2367ba | 3506 | mutex_lock(&ftrace_lock); |
b6887d79 | 3507 | __disable_ftrace_function_probe(); |
e1df4cb6 SRRH |
3508 | /* |
3509 | * Remove after the disable is called. Otherwise, if the last | |
3510 | * probe is removed, a null hash means *all enabled*. | |
3511 | */ | |
3512 | ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash); | |
7818b388 SRRH |
3513 | synchronize_sched(); |
3514 | list_for_each_entry_safe(entry, p, &free_list, free_list) { | |
3515 | list_del(&entry->free_list); | |
3516 | ftrace_free_entry(entry); | |
3517 | } | |
3f2367ba | 3518 | mutex_unlock(&ftrace_lock); |
7818b388 | 3519 | |
e1df4cb6 | 3520 | out_unlock: |
3f2367ba | 3521 | mutex_unlock(&trace_probe_ops.regex_lock); |
e1df4cb6 | 3522 | free_ftrace_hash(hash); |
59df055f SR |
3523 | } |
3524 | ||
3525 | void | |
b6887d79 | 3526 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3527 | void *data) |
3528 | { | |
b6887d79 SR |
3529 | __unregister_ftrace_function_probe(glob, ops, data, |
3530 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
3531 | } |
3532 | ||
3533 | void | |
b6887d79 | 3534 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 3535 | { |
b6887d79 | 3536 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
3537 | } |
3538 | ||
b6887d79 | 3539 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 3540 | { |
b6887d79 | 3541 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
3542 | } |
3543 | ||
f6180773 SR |
3544 | static LIST_HEAD(ftrace_commands); |
3545 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
3546 | ||
38de93ab TZ |
3547 | /* |
3548 | * Currently we only register ftrace commands from __init, so mark this | |
3549 | * __init too. | |
3550 | */ | |
3551 | __init int register_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
3552 | { |
3553 | struct ftrace_func_command *p; | |
3554 | int ret = 0; | |
3555 | ||
3556 | mutex_lock(&ftrace_cmd_mutex); | |
3557 | list_for_each_entry(p, &ftrace_commands, list) { | |
3558 | if (strcmp(cmd->name, p->name) == 0) { | |
3559 | ret = -EBUSY; | |
3560 | goto out_unlock; | |
3561 | } | |
3562 | } | |
3563 | list_add(&cmd->list, &ftrace_commands); | |
3564 | out_unlock: | |
3565 | mutex_unlock(&ftrace_cmd_mutex); | |
3566 | ||
3567 | return ret; | |
3568 | } | |
3569 | ||
38de93ab TZ |
3570 | /* |
3571 | * Currently we only unregister ftrace commands from __init, so mark | |
3572 | * this __init too. | |
3573 | */ | |
3574 | __init int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
3575 | { |
3576 | struct ftrace_func_command *p, *n; | |
3577 | int ret = -ENODEV; | |
3578 | ||
3579 | mutex_lock(&ftrace_cmd_mutex); | |
3580 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
3581 | if (strcmp(cmd->name, p->name) == 0) { | |
3582 | ret = 0; | |
3583 | list_del_init(&p->list); | |
3584 | goto out_unlock; | |
3585 | } | |
3586 | } | |
3587 | out_unlock: | |
3588 | mutex_unlock(&ftrace_cmd_mutex); | |
3589 | ||
3590 | return ret; | |
3591 | } | |
3592 | ||
33dc9b12 SR |
3593 | static int ftrace_process_regex(struct ftrace_hash *hash, |
3594 | char *buff, int len, int enable) | |
64e7c440 | 3595 | { |
f6180773 | 3596 | char *func, *command, *next = buff; |
6a24a244 | 3597 | struct ftrace_func_command *p; |
0aff1c0c | 3598 | int ret = -EINVAL; |
64e7c440 SR |
3599 | |
3600 | func = strsep(&next, ":"); | |
3601 | ||
3602 | if (!next) { | |
1cf41dd7 | 3603 | ret = ftrace_match_records(hash, func, len); |
b448c4e3 SR |
3604 | if (!ret) |
3605 | ret = -EINVAL; | |
3606 | if (ret < 0) | |
3607 | return ret; | |
3608 | return 0; | |
64e7c440 SR |
3609 | } |
3610 | ||
f6180773 | 3611 | /* command found */ |
64e7c440 SR |
3612 | |
3613 | command = strsep(&next, ":"); | |
3614 | ||
f6180773 SR |
3615 | mutex_lock(&ftrace_cmd_mutex); |
3616 | list_for_each_entry(p, &ftrace_commands, list) { | |
3617 | if (strcmp(p->name, command) == 0) { | |
43dd61c9 | 3618 | ret = p->func(hash, func, command, next, enable); |
f6180773 SR |
3619 | goto out_unlock; |
3620 | } | |
64e7c440 | 3621 | } |
f6180773 SR |
3622 | out_unlock: |
3623 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 3624 | |
f6180773 | 3625 | return ret; |
64e7c440 SR |
3626 | } |
3627 | ||
e309b41d | 3628 | static ssize_t |
41c52c0d SR |
3629 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
3630 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
3631 | { |
3632 | struct ftrace_iterator *iter; | |
689fd8b6 | 3633 | struct trace_parser *parser; |
3634 | ssize_t ret, read; | |
5072c59f | 3635 | |
4ba7978e | 3636 | if (!cnt) |
5072c59f SR |
3637 | return 0; |
3638 | ||
5072c59f SR |
3639 | if (file->f_mode & FMODE_READ) { |
3640 | struct seq_file *m = file->private_data; | |
3641 | iter = m->private; | |
3642 | } else | |
3643 | iter = file->private_data; | |
3644 | ||
f04f24fb | 3645 | if (unlikely(ftrace_disabled)) |
3f2367ba MH |
3646 | return -ENODEV; |
3647 | ||
3648 | /* iter->hash is a local copy, so we don't need regex_lock */ | |
f04f24fb | 3649 | |
689fd8b6 | 3650 | parser = &iter->parser; |
3651 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 3652 | |
4ba7978e | 3653 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 3654 | !trace_parser_cont(parser)) { |
33dc9b12 | 3655 | ret = ftrace_process_regex(iter->hash, parser->buffer, |
689fd8b6 | 3656 | parser->idx, enable); |
313254a9 | 3657 | trace_parser_clear(parser); |
7c088b51 | 3658 | if (ret < 0) |
3f2367ba | 3659 | goto out; |
eda1e328 | 3660 | } |
5072c59f | 3661 | |
5072c59f | 3662 | ret = read; |
3f2367ba | 3663 | out: |
5072c59f SR |
3664 | return ret; |
3665 | } | |
3666 | ||
fc13cb0c | 3667 | ssize_t |
41c52c0d SR |
3668 | ftrace_filter_write(struct file *file, const char __user *ubuf, |
3669 | size_t cnt, loff_t *ppos) | |
3670 | { | |
3671 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
3672 | } | |
3673 | ||
fc13cb0c | 3674 | ssize_t |
41c52c0d SR |
3675 | ftrace_notrace_write(struct file *file, const char __user *ubuf, |
3676 | size_t cnt, loff_t *ppos) | |
3677 | { | |
3678 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
3679 | } | |
3680 | ||
33dc9b12 | 3681 | static int |
647664ea MH |
3682 | ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) |
3683 | { | |
3684 | struct ftrace_func_entry *entry; | |
3685 | ||
3686 | if (!ftrace_location(ip)) | |
3687 | return -EINVAL; | |
3688 | ||
3689 | if (remove) { | |
3690 | entry = ftrace_lookup_ip(hash, ip); | |
3691 | if (!entry) | |
3692 | return -ENOENT; | |
3693 | free_hash_entry(hash, entry); | |
3694 | return 0; | |
3695 | } | |
3696 | ||
3697 | return add_hash_entry(hash, ip); | |
3698 | } | |
3699 | ||
1c80c432 SRRH |
3700 | static void ftrace_ops_update_code(struct ftrace_ops *ops) |
3701 | { | |
3702 | if (ops->flags & FTRACE_OPS_FL_ENABLED && ftrace_enabled) | |
3703 | ftrace_run_update_code(FTRACE_UPDATE_CALLS); | |
3704 | } | |
3705 | ||
647664ea MH |
3706 | static int |
3707 | ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, | |
3708 | unsigned long ip, int remove, int reset, int enable) | |
41c52c0d | 3709 | { |
33dc9b12 | 3710 | struct ftrace_hash **orig_hash; |
f45948e8 | 3711 | struct ftrace_hash *hash; |
33dc9b12 | 3712 | int ret; |
f45948e8 | 3713 | |
41c52c0d | 3714 | if (unlikely(ftrace_disabled)) |
33dc9b12 | 3715 | return -ENODEV; |
41c52c0d | 3716 | |
3f2367ba MH |
3717 | mutex_lock(&ops->regex_lock); |
3718 | ||
f45948e8 | 3719 | if (enable) |
33dc9b12 | 3720 | orig_hash = &ops->filter_hash; |
f45948e8 | 3721 | else |
33dc9b12 SR |
3722 | orig_hash = &ops->notrace_hash; |
3723 | ||
b972cc58 WN |
3724 | if (reset) |
3725 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); | |
3726 | else | |
3727 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
3728 | ||
3f2367ba MH |
3729 | if (!hash) { |
3730 | ret = -ENOMEM; | |
3731 | goto out_regex_unlock; | |
3732 | } | |
f45948e8 | 3733 | |
ac483c44 JO |
3734 | if (buf && !ftrace_match_records(hash, buf, len)) { |
3735 | ret = -EINVAL; | |
3736 | goto out_regex_unlock; | |
3737 | } | |
647664ea MH |
3738 | if (ip) { |
3739 | ret = ftrace_match_addr(hash, ip, remove); | |
3740 | if (ret < 0) | |
3741 | goto out_regex_unlock; | |
3742 | } | |
33dc9b12 SR |
3743 | |
3744 | mutex_lock(&ftrace_lock); | |
41fb61c2 | 3745 | ret = ftrace_hash_move(ops, enable, orig_hash, hash); |
1c80c432 SRRH |
3746 | if (!ret) |
3747 | ftrace_ops_update_code(ops); | |
072126f4 | 3748 | |
33dc9b12 SR |
3749 | mutex_unlock(&ftrace_lock); |
3750 | ||
ac483c44 | 3751 | out_regex_unlock: |
f04f24fb | 3752 | mutex_unlock(&ops->regex_lock); |
33dc9b12 SR |
3753 | |
3754 | free_ftrace_hash(hash); | |
3755 | return ret; | |
41c52c0d SR |
3756 | } |
3757 | ||
647664ea MH |
3758 | static int |
3759 | ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove, | |
3760 | int reset, int enable) | |
3761 | { | |
3762 | return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable); | |
3763 | } | |
3764 | ||
3765 | /** | |
3766 | * ftrace_set_filter_ip - set a function to filter on in ftrace by address | |
3767 | * @ops - the ops to set the filter with | |
3768 | * @ip - the address to add to or remove from the filter. | |
3769 | * @remove - non zero to remove the ip from the filter | |
3770 | * @reset - non zero to reset all filters before applying this filter. | |
3771 | * | |
3772 | * Filters denote which functions should be enabled when tracing is enabled | |
3773 | * If @ip is NULL, it failes to update filter. | |
3774 | */ | |
3775 | int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, | |
3776 | int remove, int reset) | |
3777 | { | |
f04f24fb | 3778 | ftrace_ops_init(ops); |
647664ea MH |
3779 | return ftrace_set_addr(ops, ip, remove, reset, 1); |
3780 | } | |
3781 | EXPORT_SYMBOL_GPL(ftrace_set_filter_ip); | |
3782 | ||
3783 | static int | |
3784 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, | |
3785 | int reset, int enable) | |
3786 | { | |
3787 | return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable); | |
3788 | } | |
3789 | ||
77a2b37d SR |
3790 | /** |
3791 | * ftrace_set_filter - set a function to filter on in ftrace | |
936e074b SR |
3792 | * @ops - the ops to set the filter with |
3793 | * @buf - the string that holds the function filter text. | |
3794 | * @len - the length of the string. | |
3795 | * @reset - non zero to reset all filters before applying this filter. | |
3796 | * | |
3797 | * Filters denote which functions should be enabled when tracing is enabled. | |
3798 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
3799 | */ | |
ac483c44 | 3800 | int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
3801 | int len, int reset) |
3802 | { | |
f04f24fb | 3803 | ftrace_ops_init(ops); |
ac483c44 | 3804 | return ftrace_set_regex(ops, buf, len, reset, 1); |
936e074b SR |
3805 | } |
3806 | EXPORT_SYMBOL_GPL(ftrace_set_filter); | |
3807 | ||
3808 | /** | |
3809 | * ftrace_set_notrace - set a function to not trace in ftrace | |
3810 | * @ops - the ops to set the notrace filter with | |
3811 | * @buf - the string that holds the function notrace text. | |
3812 | * @len - the length of the string. | |
3813 | * @reset - non zero to reset all filters before applying this filter. | |
3814 | * | |
3815 | * Notrace Filters denote which functions should not be enabled when tracing | |
3816 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
3817 | * for tracing. | |
3818 | */ | |
ac483c44 | 3819 | int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
3820 | int len, int reset) |
3821 | { | |
f04f24fb | 3822 | ftrace_ops_init(ops); |
ac483c44 | 3823 | return ftrace_set_regex(ops, buf, len, reset, 0); |
936e074b SR |
3824 | } |
3825 | EXPORT_SYMBOL_GPL(ftrace_set_notrace); | |
3826 | /** | |
8d1b065d | 3827 | * ftrace_set_global_filter - set a function to filter on with global tracers |
77a2b37d SR |
3828 | * @buf - the string that holds the function filter text. |
3829 | * @len - the length of the string. | |
3830 | * @reset - non zero to reset all filters before applying this filter. | |
3831 | * | |
3832 | * Filters denote which functions should be enabled when tracing is enabled. | |
3833 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
3834 | */ | |
936e074b | 3835 | void ftrace_set_global_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 3836 | { |
f45948e8 | 3837 | ftrace_set_regex(&global_ops, buf, len, reset, 1); |
41c52c0d | 3838 | } |
936e074b | 3839 | EXPORT_SYMBOL_GPL(ftrace_set_global_filter); |
4eebcc81 | 3840 | |
41c52c0d | 3841 | /** |
8d1b065d | 3842 | * ftrace_set_global_notrace - set a function to not trace with global tracers |
41c52c0d SR |
3843 | * @buf - the string that holds the function notrace text. |
3844 | * @len - the length of the string. | |
3845 | * @reset - non zero to reset all filters before applying this filter. | |
3846 | * | |
3847 | * Notrace Filters denote which functions should not be enabled when tracing | |
3848 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
3849 | * for tracing. | |
3850 | */ | |
936e074b | 3851 | void ftrace_set_global_notrace(unsigned char *buf, int len, int reset) |
41c52c0d | 3852 | { |
f45948e8 | 3853 | ftrace_set_regex(&global_ops, buf, len, reset, 0); |
77a2b37d | 3854 | } |
936e074b | 3855 | EXPORT_SYMBOL_GPL(ftrace_set_global_notrace); |
77a2b37d | 3856 | |
2af15d6a SR |
3857 | /* |
3858 | * command line interface to allow users to set filters on boot up. | |
3859 | */ | |
3860 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
3861 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
3862 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
3863 | ||
f1ed7c74 SRRH |
3864 | /* Used by function selftest to not test if filter is set */ |
3865 | bool ftrace_filter_param __initdata; | |
3866 | ||
2af15d6a SR |
3867 | static int __init set_ftrace_notrace(char *str) |
3868 | { | |
f1ed7c74 | 3869 | ftrace_filter_param = true; |
75761cc1 | 3870 | strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
3871 | return 1; |
3872 | } | |
3873 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
3874 | ||
3875 | static int __init set_ftrace_filter(char *str) | |
3876 | { | |
f1ed7c74 | 3877 | ftrace_filter_param = true; |
75761cc1 | 3878 | strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
3879 | return 1; |
3880 | } | |
3881 | __setup("ftrace_filter=", set_ftrace_filter); | |
3882 | ||
369bc18f | 3883 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 3884 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
0d7d9a16 | 3885 | static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata; |
faf982a6 | 3886 | static int ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer); |
801c29fd | 3887 | |
369bc18f SA |
3888 | static int __init set_graph_function(char *str) |
3889 | { | |
06f43d66 | 3890 | strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
3891 | return 1; |
3892 | } | |
3893 | __setup("ftrace_graph_filter=", set_graph_function); | |
3894 | ||
0d7d9a16 NK |
3895 | static int __init set_graph_notrace_function(char *str) |
3896 | { | |
3897 | strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE); | |
3898 | return 1; | |
3899 | } | |
3900 | __setup("ftrace_graph_notrace=", set_graph_notrace_function); | |
3901 | ||
3902 | static void __init set_ftrace_early_graph(char *buf, int enable) | |
369bc18f SA |
3903 | { |
3904 | int ret; | |
3905 | char *func; | |
0d7d9a16 NK |
3906 | unsigned long *table = ftrace_graph_funcs; |
3907 | int *count = &ftrace_graph_count; | |
3908 | ||
3909 | if (!enable) { | |
3910 | table = ftrace_graph_notrace_funcs; | |
3911 | count = &ftrace_graph_notrace_count; | |
3912 | } | |
369bc18f SA |
3913 | |
3914 | while (buf) { | |
3915 | func = strsep(&buf, ","); | |
3916 | /* we allow only one expression at a time */ | |
0d7d9a16 | 3917 | ret = ftrace_set_func(table, count, FTRACE_GRAPH_MAX_FUNCS, func); |
369bc18f SA |
3918 | if (ret) |
3919 | printk(KERN_DEBUG "ftrace: function %s not " | |
3920 | "traceable\n", func); | |
3921 | } | |
3922 | } | |
3923 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
3924 | ||
2a85a37f SR |
3925 | void __init |
3926 | ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable) | |
2af15d6a SR |
3927 | { |
3928 | char *func; | |
3929 | ||
f04f24fb MH |
3930 | ftrace_ops_init(ops); |
3931 | ||
2af15d6a SR |
3932 | while (buf) { |
3933 | func = strsep(&buf, ","); | |
f45948e8 | 3934 | ftrace_set_regex(ops, func, strlen(func), 0, enable); |
2af15d6a SR |
3935 | } |
3936 | } | |
3937 | ||
3938 | static void __init set_ftrace_early_filters(void) | |
3939 | { | |
3940 | if (ftrace_filter_buf[0]) | |
2a85a37f | 3941 | ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1); |
2af15d6a | 3942 | if (ftrace_notrace_buf[0]) |
2a85a37f | 3943 | ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0); |
369bc18f SA |
3944 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
3945 | if (ftrace_graph_buf[0]) | |
0d7d9a16 NK |
3946 | set_ftrace_early_graph(ftrace_graph_buf, 1); |
3947 | if (ftrace_graph_notrace_buf[0]) | |
3948 | set_ftrace_early_graph(ftrace_graph_notrace_buf, 0); | |
369bc18f | 3949 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
2af15d6a SR |
3950 | } |
3951 | ||
fc13cb0c | 3952 | int ftrace_regex_release(struct inode *inode, struct file *file) |
5072c59f SR |
3953 | { |
3954 | struct seq_file *m = (struct seq_file *)file->private_data; | |
3955 | struct ftrace_iterator *iter; | |
33dc9b12 | 3956 | struct ftrace_hash **orig_hash; |
689fd8b6 | 3957 | struct trace_parser *parser; |
ed926f9b | 3958 | int filter_hash; |
33dc9b12 | 3959 | int ret; |
5072c59f | 3960 | |
5072c59f SR |
3961 | if (file->f_mode & FMODE_READ) { |
3962 | iter = m->private; | |
5072c59f SR |
3963 | seq_release(inode, file); |
3964 | } else | |
3965 | iter = file->private_data; | |
3966 | ||
689fd8b6 | 3967 | parser = &iter->parser; |
3968 | if (trace_parser_loaded(parser)) { | |
3969 | parser->buffer[parser->idx] = 0; | |
1cf41dd7 | 3970 | ftrace_match_records(iter->hash, parser->buffer, parser->idx); |
5072c59f SR |
3971 | } |
3972 | ||
689fd8b6 | 3973 | trace_parser_put(parser); |
689fd8b6 | 3974 | |
3f2367ba MH |
3975 | mutex_lock(&iter->ops->regex_lock); |
3976 | ||
058e297d | 3977 | if (file->f_mode & FMODE_WRITE) { |
ed926f9b SR |
3978 | filter_hash = !!(iter->flags & FTRACE_ITER_FILTER); |
3979 | ||
3980 | if (filter_hash) | |
33dc9b12 | 3981 | orig_hash = &iter->ops->filter_hash; |
ed926f9b SR |
3982 | else |
3983 | orig_hash = &iter->ops->notrace_hash; | |
33dc9b12 | 3984 | |
058e297d | 3985 | mutex_lock(&ftrace_lock); |
41fb61c2 SR |
3986 | ret = ftrace_hash_move(iter->ops, filter_hash, |
3987 | orig_hash, iter->hash); | |
1c80c432 SRRH |
3988 | if (!ret) |
3989 | ftrace_ops_update_code(iter->ops); | |
41fb61c2 | 3990 | |
058e297d SR |
3991 | mutex_unlock(&ftrace_lock); |
3992 | } | |
3f2367ba MH |
3993 | |
3994 | mutex_unlock(&iter->ops->regex_lock); | |
33dc9b12 SR |
3995 | free_ftrace_hash(iter->hash); |
3996 | kfree(iter); | |
058e297d | 3997 | |
5072c59f SR |
3998 | return 0; |
3999 | } | |
4000 | ||
5e2336a0 | 4001 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
4002 | .open = ftrace_avail_open, |
4003 | .read = seq_read, | |
4004 | .llseek = seq_lseek, | |
3be04b47 | 4005 | .release = seq_release_private, |
5072c59f SR |
4006 | }; |
4007 | ||
647bcd03 SR |
4008 | static const struct file_operations ftrace_enabled_fops = { |
4009 | .open = ftrace_enabled_open, | |
4010 | .read = seq_read, | |
4011 | .llseek = seq_lseek, | |
4012 | .release = seq_release_private, | |
4013 | }; | |
4014 | ||
5e2336a0 | 4015 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 4016 | .open = ftrace_filter_open, |
850a80cf | 4017 | .read = seq_read, |
5072c59f | 4018 | .write = ftrace_filter_write, |
098c879e | 4019 | .llseek = tracing_lseek, |
1cf41dd7 | 4020 | .release = ftrace_regex_release, |
5072c59f SR |
4021 | }; |
4022 | ||
5e2336a0 | 4023 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 4024 | .open = ftrace_notrace_open, |
850a80cf | 4025 | .read = seq_read, |
41c52c0d | 4026 | .write = ftrace_notrace_write, |
098c879e | 4027 | .llseek = tracing_lseek, |
1cf41dd7 | 4028 | .release = ftrace_regex_release, |
41c52c0d SR |
4029 | }; |
4030 | ||
ea4e2bc4 SR |
4031 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
4032 | ||
4033 | static DEFINE_MUTEX(graph_lock); | |
4034 | ||
4035 | int ftrace_graph_count; | |
29ad23b0 | 4036 | int ftrace_graph_notrace_count; |
ea4e2bc4 | 4037 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
29ad23b0 | 4038 | unsigned long ftrace_graph_notrace_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
ea4e2bc4 | 4039 | |
faf982a6 NK |
4040 | struct ftrace_graph_data { |
4041 | unsigned long *table; | |
4042 | size_t size; | |
4043 | int *count; | |
4044 | const struct seq_operations *seq_ops; | |
4045 | }; | |
4046 | ||
ea4e2bc4 | 4047 | static void * |
85951842 | 4048 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 4049 | { |
faf982a6 NK |
4050 | struct ftrace_graph_data *fgd = m->private; |
4051 | ||
4052 | if (*pos >= *fgd->count) | |
ea4e2bc4 | 4053 | return NULL; |
faf982a6 | 4054 | return &fgd->table[*pos]; |
85951842 | 4055 | } |
ea4e2bc4 | 4056 | |
85951842 LZ |
4057 | static void * |
4058 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
4059 | { | |
4060 | (*pos)++; | |
4061 | return __g_next(m, pos); | |
ea4e2bc4 SR |
4062 | } |
4063 | ||
4064 | static void *g_start(struct seq_file *m, loff_t *pos) | |
4065 | { | |
faf982a6 NK |
4066 | struct ftrace_graph_data *fgd = m->private; |
4067 | ||
ea4e2bc4 SR |
4068 | mutex_lock(&graph_lock); |
4069 | ||
f9349a8f | 4070 | /* Nothing, tell g_show to print all functions are enabled */ |
faf982a6 | 4071 | if (!*fgd->count && !*pos) |
f9349a8f FW |
4072 | return (void *)1; |
4073 | ||
85951842 | 4074 | return __g_next(m, pos); |
ea4e2bc4 SR |
4075 | } |
4076 | ||
4077 | static void g_stop(struct seq_file *m, void *p) | |
4078 | { | |
4079 | mutex_unlock(&graph_lock); | |
4080 | } | |
4081 | ||
4082 | static int g_show(struct seq_file *m, void *v) | |
4083 | { | |
4084 | unsigned long *ptr = v; | |
ea4e2bc4 SR |
4085 | |
4086 | if (!ptr) | |
4087 | return 0; | |
4088 | ||
f9349a8f | 4089 | if (ptr == (unsigned long *)1) { |
280d1429 NK |
4090 | struct ftrace_graph_data *fgd = m->private; |
4091 | ||
4092 | if (fgd->table == ftrace_graph_funcs) | |
4093 | seq_printf(m, "#### all functions enabled ####\n"); | |
4094 | else | |
4095 | seq_printf(m, "#### no functions disabled ####\n"); | |
f9349a8f FW |
4096 | return 0; |
4097 | } | |
4098 | ||
b375a11a | 4099 | seq_printf(m, "%ps\n", (void *)*ptr); |
ea4e2bc4 SR |
4100 | |
4101 | return 0; | |
4102 | } | |
4103 | ||
88e9d34c | 4104 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
4105 | .start = g_start, |
4106 | .next = g_next, | |
4107 | .stop = g_stop, | |
4108 | .show = g_show, | |
4109 | }; | |
4110 | ||
4111 | static int | |
faf982a6 NK |
4112 | __ftrace_graph_open(struct inode *inode, struct file *file, |
4113 | struct ftrace_graph_data *fgd) | |
ea4e2bc4 SR |
4114 | { |
4115 | int ret = 0; | |
4116 | ||
ea4e2bc4 SR |
4117 | mutex_lock(&graph_lock); |
4118 | if ((file->f_mode & FMODE_WRITE) && | |
8650ae32 | 4119 | (file->f_flags & O_TRUNC)) { |
faf982a6 NK |
4120 | *fgd->count = 0; |
4121 | memset(fgd->table, 0, fgd->size * sizeof(*fgd->table)); | |
ea4e2bc4 | 4122 | } |
a4ec5e0c | 4123 | mutex_unlock(&graph_lock); |
ea4e2bc4 | 4124 | |
faf982a6 NK |
4125 | if (file->f_mode & FMODE_READ) { |
4126 | ret = seq_open(file, fgd->seq_ops); | |
4127 | if (!ret) { | |
4128 | struct seq_file *m = file->private_data; | |
4129 | m->private = fgd; | |
4130 | } | |
4131 | } else | |
4132 | file->private_data = fgd; | |
ea4e2bc4 SR |
4133 | |
4134 | return ret; | |
4135 | } | |
4136 | ||
faf982a6 NK |
4137 | static int |
4138 | ftrace_graph_open(struct inode *inode, struct file *file) | |
4139 | { | |
4140 | struct ftrace_graph_data *fgd; | |
4141 | ||
4142 | if (unlikely(ftrace_disabled)) | |
4143 | return -ENODEV; | |
4144 | ||
4145 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
4146 | if (fgd == NULL) | |
4147 | return -ENOMEM; | |
4148 | ||
4149 | fgd->table = ftrace_graph_funcs; | |
4150 | fgd->size = FTRACE_GRAPH_MAX_FUNCS; | |
4151 | fgd->count = &ftrace_graph_count; | |
4152 | fgd->seq_ops = &ftrace_graph_seq_ops; | |
4153 | ||
4154 | return __ftrace_graph_open(inode, file, fgd); | |
4155 | } | |
4156 | ||
29ad23b0 NK |
4157 | static int |
4158 | ftrace_graph_notrace_open(struct inode *inode, struct file *file) | |
4159 | { | |
4160 | struct ftrace_graph_data *fgd; | |
4161 | ||
4162 | if (unlikely(ftrace_disabled)) | |
4163 | return -ENODEV; | |
4164 | ||
4165 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
4166 | if (fgd == NULL) | |
4167 | return -ENOMEM; | |
4168 | ||
4169 | fgd->table = ftrace_graph_notrace_funcs; | |
4170 | fgd->size = FTRACE_GRAPH_MAX_FUNCS; | |
4171 | fgd->count = &ftrace_graph_notrace_count; | |
4172 | fgd->seq_ops = &ftrace_graph_seq_ops; | |
4173 | ||
4174 | return __ftrace_graph_open(inode, file, fgd); | |
4175 | } | |
4176 | ||
87827111 LZ |
4177 | static int |
4178 | ftrace_graph_release(struct inode *inode, struct file *file) | |
4179 | { | |
faf982a6 NK |
4180 | if (file->f_mode & FMODE_READ) { |
4181 | struct seq_file *m = file->private_data; | |
4182 | ||
4183 | kfree(m->private); | |
87827111 | 4184 | seq_release(inode, file); |
faf982a6 NK |
4185 | } else { |
4186 | kfree(file->private_data); | |
4187 | } | |
4188 | ||
87827111 LZ |
4189 | return 0; |
4190 | } | |
4191 | ||
ea4e2bc4 | 4192 | static int |
faf982a6 | 4193 | ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer) |
ea4e2bc4 | 4194 | { |
ea4e2bc4 SR |
4195 | struct dyn_ftrace *rec; |
4196 | struct ftrace_page *pg; | |
f9349a8f | 4197 | int search_len; |
c7c6b1fe | 4198 | int fail = 1; |
f9349a8f FW |
4199 | int type, not; |
4200 | char *search; | |
4201 | bool exists; | |
4202 | int i; | |
ea4e2bc4 | 4203 | |
f9349a8f | 4204 | /* decode regex */ |
3f6fe06d | 4205 | type = filter_parse_regex(buffer, strlen(buffer), &search, ¬); |
faf982a6 | 4206 | if (!not && *idx >= size) |
c7c6b1fe | 4207 | return -EBUSY; |
f9349a8f FW |
4208 | |
4209 | search_len = strlen(search); | |
4210 | ||
52baf119 | 4211 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
4212 | |
4213 | if (unlikely(ftrace_disabled)) { | |
4214 | mutex_unlock(&ftrace_lock); | |
4215 | return -ENODEV; | |
4216 | } | |
4217 | ||
265c831c SR |
4218 | do_for_each_ftrace_rec(pg, rec) { |
4219 | ||
b9df92d2 | 4220 | if (ftrace_match_record(rec, NULL, search, search_len, type)) { |
c7c6b1fe | 4221 | /* if it is in the array */ |
f9349a8f | 4222 | exists = false; |
c7c6b1fe | 4223 | for (i = 0; i < *idx; i++) { |
f9349a8f FW |
4224 | if (array[i] == rec->ip) { |
4225 | exists = true; | |
265c831c SR |
4226 | break; |
4227 | } | |
c7c6b1fe LZ |
4228 | } |
4229 | ||
4230 | if (!not) { | |
4231 | fail = 0; | |
4232 | if (!exists) { | |
4233 | array[(*idx)++] = rec->ip; | |
faf982a6 | 4234 | if (*idx >= size) |
c7c6b1fe LZ |
4235 | goto out; |
4236 | } | |
4237 | } else { | |
4238 | if (exists) { | |
4239 | array[i] = array[--(*idx)]; | |
4240 | array[*idx] = 0; | |
4241 | fail = 0; | |
4242 | } | |
4243 | } | |
ea4e2bc4 | 4244 | } |
265c831c | 4245 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 4246 | out: |
52baf119 | 4247 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 4248 | |
c7c6b1fe LZ |
4249 | if (fail) |
4250 | return -EINVAL; | |
4251 | ||
c7c6b1fe | 4252 | return 0; |
ea4e2bc4 SR |
4253 | } |
4254 | ||
4255 | static ssize_t | |
4256 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
4257 | size_t cnt, loff_t *ppos) | |
4258 | { | |
689fd8b6 | 4259 | struct trace_parser parser; |
6a10108b | 4260 | ssize_t read, ret = 0; |
faf982a6 | 4261 | struct ftrace_graph_data *fgd = file->private_data; |
ea4e2bc4 | 4262 | |
c7c6b1fe | 4263 | if (!cnt) |
ea4e2bc4 SR |
4264 | return 0; |
4265 | ||
6a10108b NK |
4266 | if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) |
4267 | return -ENOMEM; | |
ea4e2bc4 | 4268 | |
689fd8b6 | 4269 | read = trace_get_user(&parser, ubuf, cnt, ppos); |
ea4e2bc4 | 4270 | |
4ba7978e | 4271 | if (read >= 0 && trace_parser_loaded((&parser))) { |
689fd8b6 | 4272 | parser.buffer[parser.idx] = 0; |
4273 | ||
6a10108b NK |
4274 | mutex_lock(&graph_lock); |
4275 | ||
689fd8b6 | 4276 | /* we allow only one expression at a time */ |
faf982a6 NK |
4277 | ret = ftrace_set_func(fgd->table, fgd->count, fgd->size, |
4278 | parser.buffer); | |
6a10108b NK |
4279 | |
4280 | mutex_unlock(&graph_lock); | |
ea4e2bc4 | 4281 | } |
ea4e2bc4 | 4282 | |
6a10108b NK |
4283 | if (!ret) |
4284 | ret = read; | |
1eb90f13 | 4285 | |
689fd8b6 | 4286 | trace_parser_put(&parser); |
ea4e2bc4 SR |
4287 | |
4288 | return ret; | |
4289 | } | |
4290 | ||
4291 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
4292 | .open = ftrace_graph_open, |
4293 | .read = seq_read, | |
4294 | .write = ftrace_graph_write, | |
098c879e | 4295 | .llseek = tracing_lseek, |
87827111 | 4296 | .release = ftrace_graph_release, |
ea4e2bc4 | 4297 | }; |
29ad23b0 NK |
4298 | |
4299 | static const struct file_operations ftrace_graph_notrace_fops = { | |
4300 | .open = ftrace_graph_notrace_open, | |
4301 | .read = seq_read, | |
4302 | .write = ftrace_graph_write, | |
098c879e | 4303 | .llseek = tracing_lseek, |
29ad23b0 NK |
4304 | .release = ftrace_graph_release, |
4305 | }; | |
ea4e2bc4 SR |
4306 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
4307 | ||
591dffda SRRH |
4308 | void ftrace_create_filter_files(struct ftrace_ops *ops, |
4309 | struct dentry *parent) | |
4310 | { | |
4311 | ||
4312 | trace_create_file("set_ftrace_filter", 0644, parent, | |
4313 | ops, &ftrace_filter_fops); | |
4314 | ||
4315 | trace_create_file("set_ftrace_notrace", 0644, parent, | |
4316 | ops, &ftrace_notrace_fops); | |
4317 | } | |
4318 | ||
4319 | /* | |
4320 | * The name "destroy_filter_files" is really a misnomer. Although | |
4321 | * in the future, it may actualy delete the files, but this is | |
4322 | * really intended to make sure the ops passed in are disabled | |
4323 | * and that when this function returns, the caller is free to | |
4324 | * free the ops. | |
4325 | * | |
4326 | * The "destroy" name is only to match the "create" name that this | |
4327 | * should be paired with. | |
4328 | */ | |
4329 | void ftrace_destroy_filter_files(struct ftrace_ops *ops) | |
4330 | { | |
4331 | mutex_lock(&ftrace_lock); | |
4332 | if (ops->flags & FTRACE_OPS_FL_ENABLED) | |
4333 | ftrace_shutdown(ops, 0); | |
4334 | ops->flags |= FTRACE_OPS_FL_DELETED; | |
4335 | mutex_unlock(&ftrace_lock); | |
4336 | } | |
4337 | ||
df4fc315 | 4338 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 4339 | { |
5072c59f | 4340 | |
5452af66 FW |
4341 | trace_create_file("available_filter_functions", 0444, |
4342 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 4343 | |
647bcd03 SR |
4344 | trace_create_file("enabled_functions", 0444, |
4345 | d_tracer, NULL, &ftrace_enabled_fops); | |
4346 | ||
591dffda | 4347 | ftrace_create_filter_files(&global_ops, d_tracer); |
ad90c0e3 | 4348 | |
ea4e2bc4 | 4349 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5452af66 | 4350 | trace_create_file("set_graph_function", 0444, d_tracer, |
ea4e2bc4 SR |
4351 | NULL, |
4352 | &ftrace_graph_fops); | |
29ad23b0 NK |
4353 | trace_create_file("set_graph_notrace", 0444, d_tracer, |
4354 | NULL, | |
4355 | &ftrace_graph_notrace_fops); | |
ea4e2bc4 SR |
4356 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
4357 | ||
5072c59f SR |
4358 | return 0; |
4359 | } | |
4360 | ||
9fd49328 | 4361 | static int ftrace_cmp_ips(const void *a, const void *b) |
68950619 | 4362 | { |
9fd49328 SR |
4363 | const unsigned long *ipa = a; |
4364 | const unsigned long *ipb = b; | |
68950619 | 4365 | |
9fd49328 SR |
4366 | if (*ipa > *ipb) |
4367 | return 1; | |
4368 | if (*ipa < *ipb) | |
4369 | return -1; | |
4370 | return 0; | |
4371 | } | |
4372 | ||
4373 | static void ftrace_swap_ips(void *a, void *b, int size) | |
4374 | { | |
4375 | unsigned long *ipa = a; | |
4376 | unsigned long *ipb = b; | |
4377 | unsigned long t; | |
4378 | ||
4379 | t = *ipa; | |
4380 | *ipa = *ipb; | |
4381 | *ipb = t; | |
68950619 SR |
4382 | } |
4383 | ||
5cb084bb | 4384 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 4385 | unsigned long *start, |
68bf21aa SR |
4386 | unsigned long *end) |
4387 | { | |
706c81f8 | 4388 | struct ftrace_page *start_pg; |
a7900875 | 4389 | struct ftrace_page *pg; |
706c81f8 | 4390 | struct dyn_ftrace *rec; |
a7900875 | 4391 | unsigned long count; |
68bf21aa SR |
4392 | unsigned long *p; |
4393 | unsigned long addr; | |
4376cac6 | 4394 | unsigned long flags = 0; /* Shut up gcc */ |
a7900875 SR |
4395 | int ret = -ENOMEM; |
4396 | ||
4397 | count = end - start; | |
4398 | ||
4399 | if (!count) | |
4400 | return 0; | |
4401 | ||
9fd49328 SR |
4402 | sort(start, count, sizeof(*start), |
4403 | ftrace_cmp_ips, ftrace_swap_ips); | |
4404 | ||
706c81f8 SR |
4405 | start_pg = ftrace_allocate_pages(count); |
4406 | if (!start_pg) | |
a7900875 | 4407 | return -ENOMEM; |
68bf21aa | 4408 | |
e6ea44e9 | 4409 | mutex_lock(&ftrace_lock); |
a7900875 | 4410 | |
32082309 SR |
4411 | /* |
4412 | * Core and each module needs their own pages, as | |
4413 | * modules will free them when they are removed. | |
4414 | * Force a new page to be allocated for modules. | |
4415 | */ | |
a7900875 SR |
4416 | if (!mod) { |
4417 | WARN_ON(ftrace_pages || ftrace_pages_start); | |
4418 | /* First initialization */ | |
706c81f8 | 4419 | ftrace_pages = ftrace_pages_start = start_pg; |
a7900875 | 4420 | } else { |
32082309 | 4421 | if (!ftrace_pages) |
a7900875 | 4422 | goto out; |
32082309 | 4423 | |
a7900875 SR |
4424 | if (WARN_ON(ftrace_pages->next)) { |
4425 | /* Hmm, we have free pages? */ | |
4426 | while (ftrace_pages->next) | |
4427 | ftrace_pages = ftrace_pages->next; | |
32082309 | 4428 | } |
a7900875 | 4429 | |
706c81f8 | 4430 | ftrace_pages->next = start_pg; |
32082309 SR |
4431 | } |
4432 | ||
68bf21aa | 4433 | p = start; |
706c81f8 | 4434 | pg = start_pg; |
68bf21aa SR |
4435 | while (p < end) { |
4436 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
4437 | /* |
4438 | * Some architecture linkers will pad between | |
4439 | * the different mcount_loc sections of different | |
4440 | * object files to satisfy alignments. | |
4441 | * Skip any NULL pointers. | |
4442 | */ | |
4443 | if (!addr) | |
4444 | continue; | |
706c81f8 SR |
4445 | |
4446 | if (pg->index == pg->size) { | |
4447 | /* We should have allocated enough */ | |
4448 | if (WARN_ON(!pg->next)) | |
4449 | break; | |
4450 | pg = pg->next; | |
4451 | } | |
4452 | ||
4453 | rec = &pg->records[pg->index++]; | |
4454 | rec->ip = addr; | |
68bf21aa SR |
4455 | } |
4456 | ||
706c81f8 SR |
4457 | /* We should have used all pages */ |
4458 | WARN_ON(pg->next); | |
4459 | ||
4460 | /* Assign the last page to ftrace_pages */ | |
4461 | ftrace_pages = pg; | |
4462 | ||
a4f18ed1 | 4463 | /* |
4376cac6 SR |
4464 | * We only need to disable interrupts on start up |
4465 | * because we are modifying code that an interrupt | |
4466 | * may execute, and the modification is not atomic. | |
4467 | * But for modules, nothing runs the code we modify | |
4468 | * until we are finished with it, and there's no | |
4469 | * reason to cause large interrupt latencies while we do it. | |
a4f18ed1 | 4470 | */ |
4376cac6 SR |
4471 | if (!mod) |
4472 | local_irq_save(flags); | |
1dc43cf0 | 4473 | ftrace_update_code(mod, start_pg); |
4376cac6 SR |
4474 | if (!mod) |
4475 | local_irq_restore(flags); | |
a7900875 SR |
4476 | ret = 0; |
4477 | out: | |
e6ea44e9 | 4478 | mutex_unlock(&ftrace_lock); |
68bf21aa | 4479 | |
a7900875 | 4480 | return ret; |
68bf21aa SR |
4481 | } |
4482 | ||
93eb677d | 4483 | #ifdef CONFIG_MODULES |
32082309 SR |
4484 | |
4485 | #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next) | |
4486 | ||
e7247a15 | 4487 | void ftrace_release_mod(struct module *mod) |
93eb677d SR |
4488 | { |
4489 | struct dyn_ftrace *rec; | |
32082309 | 4490 | struct ftrace_page **last_pg; |
93eb677d | 4491 | struct ftrace_page *pg; |
a7900875 | 4492 | int order; |
93eb677d | 4493 | |
45a4a237 SR |
4494 | mutex_lock(&ftrace_lock); |
4495 | ||
e7247a15 | 4496 | if (ftrace_disabled) |
45a4a237 | 4497 | goto out_unlock; |
93eb677d | 4498 | |
32082309 SR |
4499 | /* |
4500 | * Each module has its own ftrace_pages, remove | |
4501 | * them from the list. | |
4502 | */ | |
4503 | last_pg = &ftrace_pages_start; | |
4504 | for (pg = ftrace_pages_start; pg; pg = *last_pg) { | |
4505 | rec = &pg->records[0]; | |
e7247a15 | 4506 | if (within_module_core(rec->ip, mod)) { |
93eb677d | 4507 | /* |
32082309 SR |
4508 | * As core pages are first, the first |
4509 | * page should never be a module page. | |
93eb677d | 4510 | */ |
32082309 SR |
4511 | if (WARN_ON(pg == ftrace_pages_start)) |
4512 | goto out_unlock; | |
4513 | ||
4514 | /* Check if we are deleting the last page */ | |
4515 | if (pg == ftrace_pages) | |
4516 | ftrace_pages = next_to_ftrace_page(last_pg); | |
4517 | ||
4518 | *last_pg = pg->next; | |
a7900875 SR |
4519 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
4520 | free_pages((unsigned long)pg->records, order); | |
4521 | kfree(pg); | |
32082309 SR |
4522 | } else |
4523 | last_pg = &pg->next; | |
4524 | } | |
45a4a237 | 4525 | out_unlock: |
93eb677d SR |
4526 | mutex_unlock(&ftrace_lock); |
4527 | } | |
4528 | ||
4529 | static void ftrace_init_module(struct module *mod, | |
4530 | unsigned long *start, unsigned long *end) | |
90d595fe | 4531 | { |
00fd61ae | 4532 | if (ftrace_disabled || start == end) |
fed1939c | 4533 | return; |
5cb084bb | 4534 | ftrace_process_locs(mod, start, end); |
90d595fe SR |
4535 | } |
4536 | ||
a949ae56 | 4537 | void ftrace_module_init(struct module *mod) |
93eb677d | 4538 | { |
a949ae56 SRRH |
4539 | ftrace_init_module(mod, mod->ftrace_callsites, |
4540 | mod->ftrace_callsites + | |
4541 | mod->num_ftrace_callsites); | |
8c189ea6 SRRH |
4542 | } |
4543 | ||
4544 | static int ftrace_module_notify_exit(struct notifier_block *self, | |
4545 | unsigned long val, void *data) | |
4546 | { | |
4547 | struct module *mod = data; | |
4548 | ||
4549 | if (val == MODULE_STATE_GOING) | |
e7247a15 | 4550 | ftrace_release_mod(mod); |
93eb677d SR |
4551 | |
4552 | return 0; | |
4553 | } | |
4554 | #else | |
8c189ea6 SRRH |
4555 | static int ftrace_module_notify_exit(struct notifier_block *self, |
4556 | unsigned long val, void *data) | |
93eb677d SR |
4557 | { |
4558 | return 0; | |
4559 | } | |
4560 | #endif /* CONFIG_MODULES */ | |
4561 | ||
8c189ea6 SRRH |
4562 | struct notifier_block ftrace_module_exit_nb = { |
4563 | .notifier_call = ftrace_module_notify_exit, | |
4564 | .priority = INT_MIN, /* Run after anything that can remove kprobes */ | |
4565 | }; | |
4566 | ||
68bf21aa SR |
4567 | void __init ftrace_init(void) |
4568 | { | |
1dc43cf0 JS |
4569 | extern unsigned long __start_mcount_loc[]; |
4570 | extern unsigned long __stop_mcount_loc[]; | |
3a36cb11 | 4571 | unsigned long count, flags; |
68bf21aa SR |
4572 | int ret; |
4573 | ||
68bf21aa | 4574 | local_irq_save(flags); |
3a36cb11 | 4575 | ret = ftrace_dyn_arch_init(); |
68bf21aa | 4576 | local_irq_restore(flags); |
af64a7cb | 4577 | if (ret) |
68bf21aa SR |
4578 | goto failed; |
4579 | ||
4580 | count = __stop_mcount_loc - __start_mcount_loc; | |
c867ccd8 JS |
4581 | if (!count) { |
4582 | pr_info("ftrace: No functions to be traced?\n"); | |
68bf21aa | 4583 | goto failed; |
c867ccd8 JS |
4584 | } |
4585 | ||
4586 | pr_info("ftrace: allocating %ld entries in %ld pages\n", | |
4587 | count, count / ENTRIES_PER_PAGE + 1); | |
68bf21aa SR |
4588 | |
4589 | last_ftrace_enabled = ftrace_enabled = 1; | |
4590 | ||
5cb084bb | 4591 | ret = ftrace_process_locs(NULL, |
31e88909 | 4592 | __start_mcount_loc, |
68bf21aa SR |
4593 | __stop_mcount_loc); |
4594 | ||
8c189ea6 | 4595 | ret = register_module_notifier(&ftrace_module_exit_nb); |
24ed0c4b | 4596 | if (ret) |
8c189ea6 | 4597 | pr_warning("Failed to register trace ftrace module exit notifier\n"); |
93eb677d | 4598 | |
2af15d6a SR |
4599 | set_ftrace_early_filters(); |
4600 | ||
68bf21aa SR |
4601 | return; |
4602 | failed: | |
4603 | ftrace_disabled = 1; | |
4604 | } | |
68bf21aa | 4605 | |
3d083395 | 4606 | #else |
0b6e4d56 | 4607 | |
2b499381 | 4608 | static struct ftrace_ops global_ops = { |
bd69c30b | 4609 | .func = ftrace_stub, |
f04f24fb MH |
4610 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, |
4611 | INIT_REGEX_LOCK(global_ops) | |
bd69c30b SR |
4612 | }; |
4613 | ||
0b6e4d56 FW |
4614 | static int __init ftrace_nodyn_init(void) |
4615 | { | |
4616 | ftrace_enabled = 1; | |
4617 | return 0; | |
4618 | } | |
6f415672 | 4619 | core_initcall(ftrace_nodyn_init); |
0b6e4d56 | 4620 | |
df4fc315 SR |
4621 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
4622 | static inline void ftrace_startup_enable(int command) { } | |
5a45cfe1 | 4623 | /* Keep as macros so we do not need to define the commands */ |
8a56d776 SRRH |
4624 | # define ftrace_startup(ops, command) \ |
4625 | ({ \ | |
4626 | int ___ret = __register_ftrace_function(ops); \ | |
4627 | if (!___ret) \ | |
4628 | (ops)->flags |= FTRACE_OPS_FL_ENABLED; \ | |
4629 | ___ret; \ | |
3b6cfdb1 | 4630 | }) |
1fcc1553 SRRH |
4631 | # define ftrace_shutdown(ops, command) \ |
4632 | ({ \ | |
4633 | int ___ret = __unregister_ftrace_function(ops); \ | |
4634 | if (!___ret) \ | |
4635 | (ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \ | |
4636 | ___ret; \ | |
4637 | }) | |
8a56d776 | 4638 | |
c7aafc54 IM |
4639 | # define ftrace_startup_sysctl() do { } while (0) |
4640 | # define ftrace_shutdown_sysctl() do { } while (0) | |
b848914c SR |
4641 | |
4642 | static inline int | |
195a8afc | 4643 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
b848914c SR |
4644 | { |
4645 | return 1; | |
4646 | } | |
4647 | ||
3d083395 SR |
4648 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
4649 | ||
4104d326 SRRH |
4650 | __init void ftrace_init_global_array_ops(struct trace_array *tr) |
4651 | { | |
4652 | tr->ops = &global_ops; | |
4653 | tr->ops->private = tr; | |
4654 | } | |
4655 | ||
4656 | void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func) | |
4657 | { | |
4658 | /* If we filter on pids, update to use the pid function */ | |
4659 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL) { | |
4660 | if (WARN_ON(tr->ops->func != ftrace_stub)) | |
4661 | printk("ftrace ops had %pS for function\n", | |
4662 | tr->ops->func); | |
4663 | /* Only the top level instance does pid tracing */ | |
4664 | if (!list_empty(&ftrace_pids)) { | |
4665 | set_ftrace_pid_function(func); | |
4666 | func = ftrace_pid_func; | |
4667 | } | |
4668 | } | |
4669 | tr->ops->func = func; | |
4670 | tr->ops->private = tr; | |
4671 | } | |
4672 | ||
4673 | void ftrace_reset_array_ops(struct trace_array *tr) | |
4674 | { | |
4675 | tr->ops->func = ftrace_stub; | |
4676 | } | |
4677 | ||
e248491a | 4678 | static void |
2f5f6ad9 | 4679 | ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 4680 | struct ftrace_ops *op, struct pt_regs *regs) |
e248491a | 4681 | { |
e248491a JO |
4682 | if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT))) |
4683 | return; | |
4684 | ||
4685 | /* | |
4686 | * Some of the ops may be dynamically allocated, | |
4687 | * they must be freed after a synchronize_sched(). | |
4688 | */ | |
4689 | preempt_disable_notrace(); | |
4690 | trace_recursion_set(TRACE_CONTROL_BIT); | |
b5aa3a47 SRRH |
4691 | |
4692 | /* | |
4693 | * Control funcs (perf) uses RCU. Only trace if | |
4694 | * RCU is currently active. | |
4695 | */ | |
4696 | if (!rcu_is_watching()) | |
4697 | goto out; | |
4698 | ||
0a016409 | 4699 | do_for_each_ftrace_op(op, ftrace_control_list) { |
395b97a3 SRRH |
4700 | if (!(op->flags & FTRACE_OPS_FL_STUB) && |
4701 | !ftrace_function_local_disabled(op) && | |
195a8afc | 4702 | ftrace_ops_test(op, ip, regs)) |
a1e2e31d | 4703 | op->func(ip, parent_ip, op, regs); |
0a016409 | 4704 | } while_for_each_ftrace_op(op); |
b5aa3a47 | 4705 | out: |
e248491a JO |
4706 | trace_recursion_clear(TRACE_CONTROL_BIT); |
4707 | preempt_enable_notrace(); | |
4708 | } | |
4709 | ||
4710 | static struct ftrace_ops control_ops = { | |
f04f24fb MH |
4711 | .func = ftrace_ops_control_func, |
4712 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, | |
4713 | INIT_REGEX_LOCK(control_ops) | |
e248491a JO |
4714 | }; |
4715 | ||
2f5f6ad9 SR |
4716 | static inline void |
4717 | __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 4718 | struct ftrace_ops *ignored, struct pt_regs *regs) |
b848914c | 4719 | { |
cdbe61bf | 4720 | struct ftrace_ops *op; |
edc15caf | 4721 | int bit; |
b848914c | 4722 | |
edc15caf SR |
4723 | bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX); |
4724 | if (bit < 0) | |
4725 | return; | |
b1cff0ad | 4726 | |
cdbe61bf SR |
4727 | /* |
4728 | * Some of the ops may be dynamically allocated, | |
4729 | * they must be freed after a synchronize_sched(). | |
4730 | */ | |
4731 | preempt_disable_notrace(); | |
0a016409 | 4732 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
4104d326 | 4733 | if (ftrace_ops_test(op, ip, regs)) { |
1d48d596 SRRH |
4734 | if (FTRACE_WARN_ON(!op->func)) { |
4735 | pr_warn("op=%p %pS\n", op, op); | |
4104d326 SRRH |
4736 | goto out; |
4737 | } | |
a1e2e31d | 4738 | op->func(ip, parent_ip, op, regs); |
4104d326 | 4739 | } |
0a016409 | 4740 | } while_for_each_ftrace_op(op); |
4104d326 | 4741 | out: |
cdbe61bf | 4742 | preempt_enable_notrace(); |
edc15caf | 4743 | trace_clear_recursion(bit); |
b848914c SR |
4744 | } |
4745 | ||
2f5f6ad9 SR |
4746 | /* |
4747 | * Some archs only support passing ip and parent_ip. Even though | |
4748 | * the list function ignores the op parameter, we do not want any | |
4749 | * C side effects, where a function is called without the caller | |
4750 | * sending a third parameter. | |
a1e2e31d SR |
4751 | * Archs are to support both the regs and ftrace_ops at the same time. |
4752 | * If they support ftrace_ops, it is assumed they support regs. | |
4753 | * If call backs want to use regs, they must either check for regs | |
06aeaaea MH |
4754 | * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS. |
4755 | * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved. | |
a1e2e31d SR |
4756 | * An architecture can pass partial regs with ftrace_ops and still |
4757 | * set the ARCH_SUPPORT_FTARCE_OPS. | |
2f5f6ad9 SR |
4758 | */ |
4759 | #if ARCH_SUPPORTS_FTRACE_OPS | |
4760 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 4761 | struct ftrace_ops *op, struct pt_regs *regs) |
2f5f6ad9 | 4762 | { |
a1e2e31d | 4763 | __ftrace_ops_list_func(ip, parent_ip, NULL, regs); |
2f5f6ad9 SR |
4764 | } |
4765 | #else | |
4766 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip) | |
4767 | { | |
a1e2e31d | 4768 | __ftrace_ops_list_func(ip, parent_ip, NULL, NULL); |
2f5f6ad9 SR |
4769 | } |
4770 | #endif | |
4771 | ||
e32d8956 | 4772 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
4773 | { |
4774 | struct task_struct *p; | |
e32d8956 | 4775 | int cpu; |
978f3a45 | 4776 | |
e32d8956 SR |
4777 | get_online_cpus(); |
4778 | for_each_online_cpu(cpu) { | |
4779 | p = idle_task(cpu); | |
978f3a45 | 4780 | clear_tsk_trace_trace(p); |
e32d8956 SR |
4781 | } |
4782 | put_online_cpus(); | |
4783 | } | |
978f3a45 | 4784 | |
e32d8956 SR |
4785 | static void set_ftrace_swapper(void) |
4786 | { | |
4787 | struct task_struct *p; | |
4788 | int cpu; | |
4789 | ||
4790 | get_online_cpus(); | |
4791 | for_each_online_cpu(cpu) { | |
4792 | p = idle_task(cpu); | |
4793 | set_tsk_trace_trace(p); | |
4794 | } | |
4795 | put_online_cpus(); | |
978f3a45 SR |
4796 | } |
4797 | ||
e32d8956 SR |
4798 | static void clear_ftrace_pid(struct pid *pid) |
4799 | { | |
4800 | struct task_struct *p; | |
4801 | ||
229c4ef8 | 4802 | rcu_read_lock(); |
e32d8956 SR |
4803 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
4804 | clear_tsk_trace_trace(p); | |
4805 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
4806 | rcu_read_unlock(); |
4807 | ||
e32d8956 SR |
4808 | put_pid(pid); |
4809 | } | |
4810 | ||
4811 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
4812 | { |
4813 | struct task_struct *p; | |
4814 | ||
229c4ef8 | 4815 | rcu_read_lock(); |
978f3a45 SR |
4816 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
4817 | set_tsk_trace_trace(p); | |
4818 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 4819 | rcu_read_unlock(); |
978f3a45 SR |
4820 | } |
4821 | ||
756d17ee | 4822 | static void clear_ftrace_pid_task(struct pid *pid) |
e32d8956 | 4823 | { |
756d17ee | 4824 | if (pid == ftrace_swapper_pid) |
e32d8956 SR |
4825 | clear_ftrace_swapper(); |
4826 | else | |
756d17ee | 4827 | clear_ftrace_pid(pid); |
e32d8956 SR |
4828 | } |
4829 | ||
4830 | static void set_ftrace_pid_task(struct pid *pid) | |
4831 | { | |
4832 | if (pid == ftrace_swapper_pid) | |
4833 | set_ftrace_swapper(); | |
4834 | else | |
4835 | set_ftrace_pid(pid); | |
4836 | } | |
4837 | ||
756d17ee | 4838 | static int ftrace_pid_add(int p) |
df4fc315 | 4839 | { |
978f3a45 | 4840 | struct pid *pid; |
756d17ee | 4841 | struct ftrace_pid *fpid; |
4842 | int ret = -EINVAL; | |
df4fc315 | 4843 | |
756d17ee | 4844 | mutex_lock(&ftrace_lock); |
df4fc315 | 4845 | |
756d17ee | 4846 | if (!p) |
4847 | pid = ftrace_swapper_pid; | |
4848 | else | |
4849 | pid = find_get_pid(p); | |
df4fc315 | 4850 | |
756d17ee | 4851 | if (!pid) |
4852 | goto out; | |
df4fc315 | 4853 | |
756d17ee | 4854 | ret = 0; |
df4fc315 | 4855 | |
756d17ee | 4856 | list_for_each_entry(fpid, &ftrace_pids, list) |
4857 | if (fpid->pid == pid) | |
4858 | goto out_put; | |
978f3a45 | 4859 | |
756d17ee | 4860 | ret = -ENOMEM; |
df4fc315 | 4861 | |
756d17ee | 4862 | fpid = kmalloc(sizeof(*fpid), GFP_KERNEL); |
4863 | if (!fpid) | |
4864 | goto out_put; | |
df4fc315 | 4865 | |
756d17ee | 4866 | list_add(&fpid->list, &ftrace_pids); |
4867 | fpid->pid = pid; | |
0ef8cde5 | 4868 | |
756d17ee | 4869 | set_ftrace_pid_task(pid); |
978f3a45 | 4870 | |
756d17ee | 4871 | ftrace_update_pid_func(); |
4872 | ftrace_startup_enable(0); | |
4873 | ||
4874 | mutex_unlock(&ftrace_lock); | |
4875 | return 0; | |
4876 | ||
4877 | out_put: | |
4878 | if (pid != ftrace_swapper_pid) | |
4879 | put_pid(pid); | |
978f3a45 | 4880 | |
756d17ee | 4881 | out: |
4882 | mutex_unlock(&ftrace_lock); | |
4883 | return ret; | |
4884 | } | |
4885 | ||
4886 | static void ftrace_pid_reset(void) | |
4887 | { | |
4888 | struct ftrace_pid *fpid, *safe; | |
978f3a45 | 4889 | |
756d17ee | 4890 | mutex_lock(&ftrace_lock); |
4891 | list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) { | |
4892 | struct pid *pid = fpid->pid; | |
4893 | ||
4894 | clear_ftrace_pid_task(pid); | |
4895 | ||
4896 | list_del(&fpid->list); | |
4897 | kfree(fpid); | |
df4fc315 SR |
4898 | } |
4899 | ||
df4fc315 SR |
4900 | ftrace_update_pid_func(); |
4901 | ftrace_startup_enable(0); | |
4902 | ||
e6ea44e9 | 4903 | mutex_unlock(&ftrace_lock); |
756d17ee | 4904 | } |
df4fc315 | 4905 | |
756d17ee | 4906 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
4907 | { | |
4908 | mutex_lock(&ftrace_lock); | |
4909 | ||
4910 | if (list_empty(&ftrace_pids) && (!*pos)) | |
4911 | return (void *) 1; | |
4912 | ||
4913 | return seq_list_start(&ftrace_pids, *pos); | |
4914 | } | |
4915 | ||
4916 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
4917 | { | |
4918 | if (v == (void *)1) | |
4919 | return NULL; | |
4920 | ||
4921 | return seq_list_next(v, &ftrace_pids, pos); | |
4922 | } | |
4923 | ||
4924 | static void fpid_stop(struct seq_file *m, void *p) | |
4925 | { | |
4926 | mutex_unlock(&ftrace_lock); | |
4927 | } | |
4928 | ||
4929 | static int fpid_show(struct seq_file *m, void *v) | |
4930 | { | |
4931 | const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list); | |
4932 | ||
4933 | if (v == (void *)1) { | |
4934 | seq_printf(m, "no pid\n"); | |
4935 | return 0; | |
4936 | } | |
4937 | ||
4938 | if (fpid->pid == ftrace_swapper_pid) | |
4939 | seq_printf(m, "swapper tasks\n"); | |
4940 | else | |
4941 | seq_printf(m, "%u\n", pid_vnr(fpid->pid)); | |
4942 | ||
4943 | return 0; | |
4944 | } | |
4945 | ||
4946 | static const struct seq_operations ftrace_pid_sops = { | |
4947 | .start = fpid_start, | |
4948 | .next = fpid_next, | |
4949 | .stop = fpid_stop, | |
4950 | .show = fpid_show, | |
4951 | }; | |
4952 | ||
4953 | static int | |
4954 | ftrace_pid_open(struct inode *inode, struct file *file) | |
4955 | { | |
4956 | int ret = 0; | |
4957 | ||
4958 | if ((file->f_mode & FMODE_WRITE) && | |
4959 | (file->f_flags & O_TRUNC)) | |
4960 | ftrace_pid_reset(); | |
4961 | ||
4962 | if (file->f_mode & FMODE_READ) | |
4963 | ret = seq_open(file, &ftrace_pid_sops); | |
4964 | ||
4965 | return ret; | |
4966 | } | |
4967 | ||
df4fc315 SR |
4968 | static ssize_t |
4969 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
4970 | size_t cnt, loff_t *ppos) | |
4971 | { | |
457dc928 | 4972 | char buf[64], *tmp; |
df4fc315 SR |
4973 | long val; |
4974 | int ret; | |
4975 | ||
4976 | if (cnt >= sizeof(buf)) | |
4977 | return -EINVAL; | |
4978 | ||
4979 | if (copy_from_user(&buf, ubuf, cnt)) | |
4980 | return -EFAULT; | |
4981 | ||
4982 | buf[cnt] = 0; | |
4983 | ||
756d17ee | 4984 | /* |
4985 | * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid" | |
4986 | * to clean the filter quietly. | |
4987 | */ | |
457dc928 IM |
4988 | tmp = strstrip(buf); |
4989 | if (strlen(tmp) == 0) | |
756d17ee | 4990 | return 1; |
4991 | ||
bcd83ea6 | 4992 | ret = kstrtol(tmp, 10, &val); |
df4fc315 SR |
4993 | if (ret < 0) |
4994 | return ret; | |
4995 | ||
756d17ee | 4996 | ret = ftrace_pid_add(val); |
df4fc315 | 4997 | |
756d17ee | 4998 | return ret ? ret : cnt; |
4999 | } | |
df4fc315 | 5000 | |
756d17ee | 5001 | static int |
5002 | ftrace_pid_release(struct inode *inode, struct file *file) | |
5003 | { | |
5004 | if (file->f_mode & FMODE_READ) | |
5005 | seq_release(inode, file); | |
df4fc315 | 5006 | |
756d17ee | 5007 | return 0; |
df4fc315 SR |
5008 | } |
5009 | ||
5e2336a0 | 5010 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 5011 | .open = ftrace_pid_open, |
5012 | .write = ftrace_pid_write, | |
5013 | .read = seq_read, | |
098c879e | 5014 | .llseek = tracing_lseek, |
756d17ee | 5015 | .release = ftrace_pid_release, |
df4fc315 SR |
5016 | }; |
5017 | ||
5018 | static __init int ftrace_init_debugfs(void) | |
5019 | { | |
5020 | struct dentry *d_tracer; | |
df4fc315 SR |
5021 | |
5022 | d_tracer = tracing_init_dentry(); | |
5023 | if (!d_tracer) | |
5024 | return 0; | |
5025 | ||
5026 | ftrace_init_dyn_debugfs(d_tracer); | |
5027 | ||
5452af66 FW |
5028 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
5029 | NULL, &ftrace_pid_fops); | |
493762fc SR |
5030 | |
5031 | ftrace_profile_debugfs(d_tracer); | |
5032 | ||
df4fc315 SR |
5033 | return 0; |
5034 | } | |
df4fc315 SR |
5035 | fs_initcall(ftrace_init_debugfs); |
5036 | ||
a2bb6a3d | 5037 | /** |
81adbdc0 | 5038 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
5039 | * |
5040 | * This function should be used by panic code. It stops ftrace | |
5041 | * but in a not so nice way. If you need to simply kill ftrace | |
5042 | * from a non-atomic section, use ftrace_kill. | |
5043 | */ | |
81adbdc0 | 5044 | void ftrace_kill(void) |
a2bb6a3d SR |
5045 | { |
5046 | ftrace_disabled = 1; | |
5047 | ftrace_enabled = 0; | |
a2bb6a3d SR |
5048 | clear_ftrace_function(); |
5049 | } | |
5050 | ||
e0a413f6 SR |
5051 | /** |
5052 | * Test if ftrace is dead or not. | |
5053 | */ | |
5054 | int ftrace_is_dead(void) | |
5055 | { | |
5056 | return ftrace_disabled; | |
5057 | } | |
5058 | ||
16444a8a | 5059 | /** |
3d083395 SR |
5060 | * register_ftrace_function - register a function for profiling |
5061 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 5062 | * |
3d083395 SR |
5063 | * Register a function to be called by all functions in the |
5064 | * kernel. | |
5065 | * | |
5066 | * Note: @ops->func and all the functions it calls must be labeled | |
5067 | * with "notrace", otherwise it will go into a | |
5068 | * recursive loop. | |
16444a8a | 5069 | */ |
3d083395 | 5070 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 5071 | { |
45a4a237 | 5072 | int ret = -1; |
4eebcc81 | 5073 | |
f04f24fb MH |
5074 | ftrace_ops_init(ops); |
5075 | ||
e6ea44e9 | 5076 | mutex_lock(&ftrace_lock); |
e7d3737e | 5077 | |
8a56d776 | 5078 | ret = ftrace_startup(ops, 0); |
b848914c | 5079 | |
e6ea44e9 | 5080 | mutex_unlock(&ftrace_lock); |
8d240dd8 | 5081 | |
b0fc494f | 5082 | return ret; |
3d083395 | 5083 | } |
cdbe61bf | 5084 | EXPORT_SYMBOL_GPL(register_ftrace_function); |
3d083395 SR |
5085 | |
5086 | /** | |
32632920 | 5087 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
5088 | * @ops - ops structure that holds the function to unregister |
5089 | * | |
5090 | * Unregister a function that was added to be called by ftrace profiling. | |
5091 | */ | |
5092 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
5093 | { | |
5094 | int ret; | |
5095 | ||
e6ea44e9 | 5096 | mutex_lock(&ftrace_lock); |
8a56d776 | 5097 | ret = ftrace_shutdown(ops, 0); |
e6ea44e9 | 5098 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
5099 | |
5100 | return ret; | |
5101 | } | |
cdbe61bf | 5102 | EXPORT_SYMBOL_GPL(unregister_ftrace_function); |
b0fc494f | 5103 | |
e309b41d | 5104 | int |
b0fc494f | 5105 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
8d65af78 | 5106 | void __user *buffer, size_t *lenp, |
b0fc494f SR |
5107 | loff_t *ppos) |
5108 | { | |
45a4a237 | 5109 | int ret = -ENODEV; |
4eebcc81 | 5110 | |
e6ea44e9 | 5111 | mutex_lock(&ftrace_lock); |
b0fc494f | 5112 | |
45a4a237 SR |
5113 | if (unlikely(ftrace_disabled)) |
5114 | goto out; | |
5115 | ||
5116 | ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
b0fc494f | 5117 | |
a32c7765 | 5118 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
5119 | goto out; |
5120 | ||
a32c7765 | 5121 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f SR |
5122 | |
5123 | if (ftrace_enabled) { | |
5124 | ||
5125 | ftrace_startup_sysctl(); | |
5126 | ||
5127 | /* we are starting ftrace again */ | |
5000c418 JK |
5128 | if (ftrace_ops_list != &ftrace_list_end) |
5129 | update_ftrace_function(); | |
b0fc494f SR |
5130 | |
5131 | } else { | |
5132 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
5133 | ftrace_trace_function = ftrace_stub; | |
5134 | ||
5135 | ftrace_shutdown_sysctl(); | |
5136 | } | |
5137 | ||
5138 | out: | |
e6ea44e9 | 5139 | mutex_unlock(&ftrace_lock); |
3d083395 | 5140 | return ret; |
16444a8a | 5141 | } |
f17845e5 | 5142 | |
fb52607a | 5143 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 5144 | |
597af815 | 5145 | static int ftrace_graph_active; |
e7d3737e | 5146 | |
e49dc19c SR |
5147 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
5148 | { | |
5149 | return 0; | |
5150 | } | |
5151 | ||
287b6e68 FW |
5152 | /* The callbacks that hook a function */ |
5153 | trace_func_graph_ret_t ftrace_graph_return = | |
5154 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 5155 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
23a8e844 | 5156 | static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
5157 | |
5158 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
5159 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
5160 | { | |
5161 | int i; | |
5162 | int ret = 0; | |
5163 | unsigned long flags; | |
5164 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
5165 | struct task_struct *g, *t; | |
5166 | ||
5167 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
5168 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
5169 | * sizeof(struct ftrace_ret_stack), | |
5170 | GFP_KERNEL); | |
5171 | if (!ret_stack_list[i]) { | |
5172 | start = 0; | |
5173 | end = i; | |
5174 | ret = -ENOMEM; | |
5175 | goto free; | |
5176 | } | |
5177 | } | |
5178 | ||
5179 | read_lock_irqsave(&tasklist_lock, flags); | |
5180 | do_each_thread(g, t) { | |
5181 | if (start == end) { | |
5182 | ret = -EAGAIN; | |
5183 | goto unlock; | |
5184 | } | |
5185 | ||
5186 | if (t->ret_stack == NULL) { | |
380c4b14 | 5187 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 5188 | atomic_set(&t->trace_overrun, 0); |
26c01624 SR |
5189 | t->curr_ret_stack = -1; |
5190 | /* Make sure the tasks see the -1 first: */ | |
5191 | smp_wmb(); | |
5192 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
5193 | } |
5194 | } while_each_thread(g, t); | |
5195 | ||
5196 | unlock: | |
5197 | read_unlock_irqrestore(&tasklist_lock, flags); | |
5198 | free: | |
5199 | for (i = start; i < end; i++) | |
5200 | kfree(ret_stack_list[i]); | |
5201 | return ret; | |
5202 | } | |
5203 | ||
8aef2d28 | 5204 | static void |
38516ab5 SR |
5205 | ftrace_graph_probe_sched_switch(void *ignore, |
5206 | struct task_struct *prev, struct task_struct *next) | |
8aef2d28 SR |
5207 | { |
5208 | unsigned long long timestamp; | |
5209 | int index; | |
5210 | ||
be6f164a SR |
5211 | /* |
5212 | * Does the user want to count the time a function was asleep. | |
5213 | * If so, do not update the time stamps. | |
5214 | */ | |
5215 | if (trace_flags & TRACE_ITER_SLEEP_TIME) | |
5216 | return; | |
5217 | ||
8aef2d28 SR |
5218 | timestamp = trace_clock_local(); |
5219 | ||
5220 | prev->ftrace_timestamp = timestamp; | |
5221 | ||
5222 | /* only process tasks that we timestamped */ | |
5223 | if (!next->ftrace_timestamp) | |
5224 | return; | |
5225 | ||
5226 | /* | |
5227 | * Update all the counters in next to make up for the | |
5228 | * time next was sleeping. | |
5229 | */ | |
5230 | timestamp -= next->ftrace_timestamp; | |
5231 | ||
5232 | for (index = next->curr_ret_stack; index >= 0; index--) | |
5233 | next->ret_stack[index].calltime += timestamp; | |
5234 | } | |
5235 | ||
f201ae23 | 5236 | /* Allocate a return stack for each task */ |
fb52607a | 5237 | static int start_graph_tracing(void) |
f201ae23 FW |
5238 | { |
5239 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 5240 | int ret, cpu; |
f201ae23 FW |
5241 | |
5242 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
5243 | sizeof(struct ftrace_ret_stack *), | |
5244 | GFP_KERNEL); | |
5245 | ||
5246 | if (!ret_stack_list) | |
5247 | return -ENOMEM; | |
5248 | ||
5b058bcd | 5249 | /* The cpu_boot init_task->ret_stack will never be freed */ |
179c498a SR |
5250 | for_each_online_cpu(cpu) { |
5251 | if (!idle_task(cpu)->ret_stack) | |
868baf07 | 5252 | ftrace_graph_init_idle_task(idle_task(cpu), cpu); |
179c498a | 5253 | } |
5b058bcd | 5254 | |
f201ae23 FW |
5255 | do { |
5256 | ret = alloc_retstack_tasklist(ret_stack_list); | |
5257 | } while (ret == -EAGAIN); | |
5258 | ||
8aef2d28 | 5259 | if (!ret) { |
38516ab5 | 5260 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
8aef2d28 SR |
5261 | if (ret) |
5262 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
5263 | " probe to kernel_sched_switch\n"); | |
5264 | } | |
5265 | ||
f201ae23 FW |
5266 | kfree(ret_stack_list); |
5267 | return ret; | |
5268 | } | |
5269 | ||
4a2b8dda FW |
5270 | /* |
5271 | * Hibernation protection. | |
5272 | * The state of the current task is too much unstable during | |
5273 | * suspend/restore to disk. We want to protect against that. | |
5274 | */ | |
5275 | static int | |
5276 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
5277 | void *unused) | |
5278 | { | |
5279 | switch (state) { | |
5280 | case PM_HIBERNATION_PREPARE: | |
5281 | pause_graph_tracing(); | |
5282 | break; | |
5283 | ||
5284 | case PM_POST_HIBERNATION: | |
5285 | unpause_graph_tracing(); | |
5286 | break; | |
5287 | } | |
5288 | return NOTIFY_DONE; | |
5289 | } | |
5290 | ||
23a8e844 SRRH |
5291 | static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace) |
5292 | { | |
5293 | if (!ftrace_ops_test(&global_ops, trace->func, NULL)) | |
5294 | return 0; | |
5295 | return __ftrace_graph_entry(trace); | |
5296 | } | |
5297 | ||
5298 | /* | |
5299 | * The function graph tracer should only trace the functions defined | |
5300 | * by set_ftrace_filter and set_ftrace_notrace. If another function | |
5301 | * tracer ops is registered, the graph tracer requires testing the | |
5302 | * function against the global ops, and not just trace any function | |
5303 | * that any ftrace_ops registered. | |
5304 | */ | |
5305 | static void update_function_graph_func(void) | |
5306 | { | |
5307 | if (ftrace_ops_list == &ftrace_list_end || | |
5308 | (ftrace_ops_list == &global_ops && | |
5309 | global_ops.next == &ftrace_list_end)) | |
5310 | ftrace_graph_entry = __ftrace_graph_entry; | |
5311 | else | |
5312 | ftrace_graph_entry = ftrace_graph_entry_test; | |
5313 | } | |
5314 | ||
8275f69f MK |
5315 | static struct notifier_block ftrace_suspend_notifier = { |
5316 | .notifier_call = ftrace_suspend_notifier_call, | |
5317 | }; | |
5318 | ||
287b6e68 FW |
5319 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
5320 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 5321 | { |
e7d3737e FW |
5322 | int ret = 0; |
5323 | ||
e6ea44e9 | 5324 | mutex_lock(&ftrace_lock); |
e7d3737e | 5325 | |
05ce5818 | 5326 | /* we currently allow only one tracer registered at a time */ |
597af815 | 5327 | if (ftrace_graph_active) { |
05ce5818 SR |
5328 | ret = -EBUSY; |
5329 | goto out; | |
5330 | } | |
5331 | ||
4a2b8dda FW |
5332 | register_pm_notifier(&ftrace_suspend_notifier); |
5333 | ||
597af815 | 5334 | ftrace_graph_active++; |
fb52607a | 5335 | ret = start_graph_tracing(); |
f201ae23 | 5336 | if (ret) { |
597af815 | 5337 | ftrace_graph_active--; |
f201ae23 FW |
5338 | goto out; |
5339 | } | |
e53a6319 | 5340 | |
287b6e68 | 5341 | ftrace_graph_return = retfunc; |
23a8e844 SRRH |
5342 | |
5343 | /* | |
5344 | * Update the indirect function to the entryfunc, and the | |
5345 | * function that gets called to the entry_test first. Then | |
5346 | * call the update fgraph entry function to determine if | |
5347 | * the entryfunc should be called directly or not. | |
5348 | */ | |
5349 | __ftrace_graph_entry = entryfunc; | |
5350 | ftrace_graph_entry = ftrace_graph_entry_test; | |
5351 | update_function_graph_func(); | |
e53a6319 | 5352 | |
fd06a549 SRRH |
5353 | /* Function graph doesn't use the .func field of global_ops */ |
5354 | global_ops.flags |= FTRACE_OPS_FL_STUB; | |
5355 | ||
79922b80 SRRH |
5356 | #ifdef CONFIG_DYNAMIC_FTRACE |
5357 | /* Optimize function graph calling (if implemented by arch) */ | |
646d7043 SRRH |
5358 | if (FTRACE_GRAPH_TRAMP_ADDR != 0) |
5359 | global_ops.trampoline = FTRACE_GRAPH_TRAMP_ADDR; | |
79922b80 SRRH |
5360 | #endif |
5361 | ||
fd06a549 | 5362 | ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET); |
e7d3737e FW |
5363 | |
5364 | out: | |
e6ea44e9 | 5365 | mutex_unlock(&ftrace_lock); |
e7d3737e | 5366 | return ret; |
15e6cb36 FW |
5367 | } |
5368 | ||
fb52607a | 5369 | void unregister_ftrace_graph(void) |
15e6cb36 | 5370 | { |
e6ea44e9 | 5371 | mutex_lock(&ftrace_lock); |
e7d3737e | 5372 | |
597af815 | 5373 | if (unlikely(!ftrace_graph_active)) |
2aad1b76 SR |
5374 | goto out; |
5375 | ||
597af815 | 5376 | ftrace_graph_active--; |
287b6e68 | 5377 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 5378 | ftrace_graph_entry = ftrace_graph_entry_stub; |
23a8e844 | 5379 | __ftrace_graph_entry = ftrace_graph_entry_stub; |
fd06a549 SRRH |
5380 | ftrace_shutdown(&global_ops, FTRACE_STOP_FUNC_RET); |
5381 | global_ops.flags &= ~FTRACE_OPS_FL_STUB; | |
79922b80 | 5382 | #ifdef CONFIG_DYNAMIC_FTRACE |
646d7043 SRRH |
5383 | if (FTRACE_GRAPH_TRAMP_ADDR != 0) |
5384 | global_ops.trampoline = 0; | |
79922b80 | 5385 | #endif |
4a2b8dda | 5386 | unregister_pm_notifier(&ftrace_suspend_notifier); |
38516ab5 | 5387 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
e7d3737e | 5388 | |
2aad1b76 | 5389 | out: |
e6ea44e9 | 5390 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 5391 | } |
f201ae23 | 5392 | |
868baf07 SR |
5393 | static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack); |
5394 | ||
5395 | static void | |
5396 | graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack) | |
5397 | { | |
5398 | atomic_set(&t->tracing_graph_pause, 0); | |
5399 | atomic_set(&t->trace_overrun, 0); | |
5400 | t->ftrace_timestamp = 0; | |
25985edc | 5401 | /* make curr_ret_stack visible before we add the ret_stack */ |
868baf07 SR |
5402 | smp_wmb(); |
5403 | t->ret_stack = ret_stack; | |
5404 | } | |
5405 | ||
5406 | /* | |
5407 | * Allocate a return stack for the idle task. May be the first | |
5408 | * time through, or it may be done by CPU hotplug online. | |
5409 | */ | |
5410 | void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) | |
5411 | { | |
5412 | t->curr_ret_stack = -1; | |
5413 | /* | |
5414 | * The idle task has no parent, it either has its own | |
5415 | * stack or no stack at all. | |
5416 | */ | |
5417 | if (t->ret_stack) | |
5418 | WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu)); | |
5419 | ||
5420 | if (ftrace_graph_active) { | |
5421 | struct ftrace_ret_stack *ret_stack; | |
5422 | ||
5423 | ret_stack = per_cpu(idle_ret_stack, cpu); | |
5424 | if (!ret_stack) { | |
5425 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
5426 | * sizeof(struct ftrace_ret_stack), | |
5427 | GFP_KERNEL); | |
5428 | if (!ret_stack) | |
5429 | return; | |
5430 | per_cpu(idle_ret_stack, cpu) = ret_stack; | |
5431 | } | |
5432 | graph_init_task(t, ret_stack); | |
5433 | } | |
5434 | } | |
5435 | ||
f201ae23 | 5436 | /* Allocate a return stack for newly created task */ |
fb52607a | 5437 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 5438 | { |
84047e36 SR |
5439 | /* Make sure we do not use the parent ret_stack */ |
5440 | t->ret_stack = NULL; | |
ea14eb71 | 5441 | t->curr_ret_stack = -1; |
84047e36 | 5442 | |
597af815 | 5443 | if (ftrace_graph_active) { |
82310a32 SR |
5444 | struct ftrace_ret_stack *ret_stack; |
5445 | ||
5446 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
f201ae23 FW |
5447 | * sizeof(struct ftrace_ret_stack), |
5448 | GFP_KERNEL); | |
82310a32 | 5449 | if (!ret_stack) |
f201ae23 | 5450 | return; |
868baf07 | 5451 | graph_init_task(t, ret_stack); |
84047e36 | 5452 | } |
f201ae23 FW |
5453 | } |
5454 | ||
fb52607a | 5455 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 5456 | { |
eae849ca FW |
5457 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
5458 | ||
f201ae23 | 5459 | t->ret_stack = NULL; |
eae849ca FW |
5460 | /* NULL must become visible to IRQs before we free it: */ |
5461 | barrier(); | |
5462 | ||
5463 | kfree(ret_stack); | |
f201ae23 | 5464 | } |
15e6cb36 | 5465 | #endif |