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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 | |
e248491a JO |
65 | #define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_CONTROL) |
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 | |
60a7ecf4 | 83 | /* Quick disabling of function tracer. */ |
2f5f6ad9 SR |
84 | int function_trace_stop __read_mostly; |
85 | ||
86 | /* Current function tracing op */ | |
87 | struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end; | |
405e1d83 SRRH |
88 | /* What to set function_trace_op to */ |
89 | static struct ftrace_ops *set_function_trace_op; | |
60a7ecf4 | 90 | |
756d17ee | 91 | /* List for set_ftrace_pid's pids. */ |
92 | LIST_HEAD(ftrace_pids); | |
93 | struct ftrace_pid { | |
94 | struct list_head list; | |
95 | struct pid *pid; | |
96 | }; | |
97 | ||
4eebcc81 SR |
98 | /* |
99 | * ftrace_disabled is set when an anomaly is discovered. | |
100 | * ftrace_disabled is much stronger than ftrace_enabled. | |
101 | */ | |
102 | static int ftrace_disabled __read_mostly; | |
103 | ||
52baf119 | 104 | static DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 105 | |
b848914c | 106 | static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end; |
e248491a | 107 | static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end; |
b848914c | 108 | static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end; |
16444a8a | 109 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
df4fc315 | 110 | ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; |
2b499381 | 111 | static struct ftrace_ops global_ops; |
e248491a | 112 | static struct ftrace_ops control_ops; |
16444a8a | 113 | |
2f5f6ad9 SR |
114 | #if ARCH_SUPPORTS_FTRACE_OPS |
115 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 116 | struct ftrace_ops *op, struct pt_regs *regs); |
2f5f6ad9 SR |
117 | #else |
118 | /* See comment below, where ftrace_ops_list_func is defined */ | |
119 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip); | |
120 | #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops) | |
121 | #endif | |
b848914c | 122 | |
0a016409 SR |
123 | /* |
124 | * Traverse the ftrace_global_list, invoking all entries. The reason that we | |
1bb539ca | 125 | * can use rcu_dereference_raw_notrace() is that elements removed from this list |
0a016409 | 126 | * are simply leaked, so there is no need to interact with a grace-period |
1bb539ca | 127 | * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle |
0a016409 SR |
128 | * concurrent insertions into the ftrace_global_list. |
129 | * | |
130 | * Silly Alpha and silly pointer-speculation compiler optimizations! | |
131 | */ | |
132 | #define do_for_each_ftrace_op(op, list) \ | |
1bb539ca | 133 | op = rcu_dereference_raw_notrace(list); \ |
0a016409 SR |
134 | do |
135 | ||
136 | /* | |
137 | * Optimized for just a single item in the list (as that is the normal case). | |
138 | */ | |
139 | #define while_for_each_ftrace_op(op) \ | |
1bb539ca | 140 | while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \ |
0a016409 SR |
141 | unlikely((op) != &ftrace_list_end)) |
142 | ||
f04f24fb MH |
143 | static inline void ftrace_ops_init(struct ftrace_ops *ops) |
144 | { | |
145 | #ifdef CONFIG_DYNAMIC_FTRACE | |
146 | if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) { | |
147 | mutex_init(&ops->regex_lock); | |
148 | ops->flags |= FTRACE_OPS_FL_INITIALIZED; | |
149 | } | |
150 | #endif | |
151 | } | |
152 | ||
ea701f11 SR |
153 | /** |
154 | * ftrace_nr_registered_ops - return number of ops registered | |
155 | * | |
156 | * Returns the number of ftrace_ops registered and tracing functions | |
157 | */ | |
158 | int ftrace_nr_registered_ops(void) | |
159 | { | |
160 | struct ftrace_ops *ops; | |
161 | int cnt = 0; | |
162 | ||
163 | mutex_lock(&ftrace_lock); | |
164 | ||
165 | for (ops = ftrace_ops_list; | |
166 | ops != &ftrace_list_end; ops = ops->next) | |
167 | cnt++; | |
168 | ||
169 | mutex_unlock(&ftrace_lock); | |
170 | ||
171 | return cnt; | |
172 | } | |
173 | ||
2f5f6ad9 SR |
174 | static void |
175 | ftrace_global_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 176 | struct ftrace_ops *op, struct pt_regs *regs) |
16444a8a | 177 | { |
c29f122c SR |
178 | int bit; |
179 | ||
edc15caf SR |
180 | bit = trace_test_and_set_recursion(TRACE_GLOBAL_START, TRACE_GLOBAL_MAX); |
181 | if (bit < 0) | |
b1cff0ad | 182 | return; |
16444a8a | 183 | |
0a016409 | 184 | do_for_each_ftrace_op(op, ftrace_global_list) { |
a1e2e31d | 185 | op->func(ip, parent_ip, op, regs); |
0a016409 | 186 | } while_for_each_ftrace_op(op); |
edc15caf SR |
187 | |
188 | trace_clear_recursion(bit); | |
16444a8a ACM |
189 | } |
190 | ||
2f5f6ad9 | 191 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 192 | struct ftrace_ops *op, struct pt_regs *regs) |
df4fc315 | 193 | { |
0ef8cde5 | 194 | if (!test_tsk_trace_trace(current)) |
df4fc315 SR |
195 | return; |
196 | ||
a1e2e31d | 197 | ftrace_pid_function(ip, parent_ip, op, regs); |
df4fc315 SR |
198 | } |
199 | ||
200 | static void set_ftrace_pid_function(ftrace_func_t func) | |
201 | { | |
202 | /* do not set ftrace_pid_function to itself! */ | |
203 | if (func != ftrace_pid_func) | |
204 | ftrace_pid_function = func; | |
205 | } | |
206 | ||
16444a8a | 207 | /** |
3d083395 | 208 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 209 | * |
3d083395 SR |
210 | * This NULLs the ftrace function and in essence stops |
211 | * tracing. There may be lag | |
16444a8a | 212 | */ |
3d083395 | 213 | void clear_ftrace_function(void) |
16444a8a | 214 | { |
3d083395 | 215 | ftrace_trace_function = ftrace_stub; |
df4fc315 | 216 | ftrace_pid_function = ftrace_stub; |
3d083395 SR |
217 | } |
218 | ||
e248491a JO |
219 | static void control_ops_disable_all(struct ftrace_ops *ops) |
220 | { | |
221 | int cpu; | |
222 | ||
223 | for_each_possible_cpu(cpu) | |
224 | *per_cpu_ptr(ops->disabled, cpu) = 1; | |
225 | } | |
226 | ||
227 | static int control_ops_alloc(struct ftrace_ops *ops) | |
228 | { | |
229 | int __percpu *disabled; | |
230 | ||
231 | disabled = alloc_percpu(int); | |
232 | if (!disabled) | |
233 | return -ENOMEM; | |
234 | ||
235 | ops->disabled = disabled; | |
236 | control_ops_disable_all(ops); | |
237 | return 0; | |
238 | } | |
239 | ||
240 | static void control_ops_free(struct ftrace_ops *ops) | |
241 | { | |
242 | free_percpu(ops->disabled); | |
243 | } | |
244 | ||
2b499381 | 245 | static void update_global_ops(void) |
491d0dcf SR |
246 | { |
247 | ftrace_func_t func; | |
248 | ||
249 | /* | |
250 | * If there's only one function registered, then call that | |
251 | * function directly. Otherwise, we need to iterate over the | |
252 | * registered callers. | |
253 | */ | |
b848914c | 254 | if (ftrace_global_list == &ftrace_list_end || |
63503794 | 255 | ftrace_global_list->next == &ftrace_list_end) { |
b848914c | 256 | func = ftrace_global_list->func; |
63503794 SR |
257 | /* |
258 | * As we are calling the function directly. | |
259 | * If it does not have recursion protection, | |
260 | * the function_trace_op needs to be updated | |
261 | * accordingly. | |
262 | */ | |
263 | if (ftrace_global_list->flags & FTRACE_OPS_FL_RECURSION_SAFE) | |
264 | global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE; | |
265 | else | |
266 | global_ops.flags &= ~FTRACE_OPS_FL_RECURSION_SAFE; | |
267 | } else { | |
b848914c | 268 | func = ftrace_global_list_func; |
63503794 SR |
269 | /* The list has its own recursion protection. */ |
270 | global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE; | |
271 | } | |
272 | ||
491d0dcf SR |
273 | |
274 | /* If we filter on pids, update to use the pid function */ | |
275 | if (!list_empty(&ftrace_pids)) { | |
276 | set_ftrace_pid_function(func); | |
277 | func = ftrace_pid_func; | |
278 | } | |
2b499381 SR |
279 | |
280 | global_ops.func = func; | |
281 | } | |
282 | ||
405e1d83 SRRH |
283 | static void ftrace_sync(struct work_struct *work) |
284 | { | |
285 | /* | |
286 | * This function is just a stub to implement a hard force | |
287 | * of synchronize_sched(). This requires synchronizing | |
288 | * tasks even in userspace and idle. | |
289 | * | |
290 | * Yes, function tracing is rude. | |
291 | */ | |
292 | } | |
293 | ||
294 | static void ftrace_sync_ipi(void *data) | |
295 | { | |
296 | /* Probably not needed, but do it anyway */ | |
297 | smp_rmb(); | |
298 | } | |
299 | ||
2b499381 SR |
300 | static void update_ftrace_function(void) |
301 | { | |
302 | ftrace_func_t func; | |
303 | ||
304 | update_global_ops(); | |
305 | ||
cdbe61bf SR |
306 | /* |
307 | * If we are at the end of the list and this ops is | |
4740974a SR |
308 | * recursion safe and not dynamic and the arch supports passing ops, |
309 | * then have the mcount trampoline call the function directly. | |
cdbe61bf | 310 | */ |
b848914c | 311 | if (ftrace_ops_list == &ftrace_list_end || |
cdbe61bf | 312 | (ftrace_ops_list->next == &ftrace_list_end && |
2f5f6ad9 | 313 | !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC) && |
4740974a | 314 | (ftrace_ops_list->flags & FTRACE_OPS_FL_RECURSION_SAFE) && |
ccf3672d | 315 | !FTRACE_FORCE_LIST_FUNC)) { |
2f5f6ad9 SR |
316 | /* Set the ftrace_ops that the arch callback uses */ |
317 | if (ftrace_ops_list == &global_ops) | |
405e1d83 | 318 | set_function_trace_op = ftrace_global_list; |
2f5f6ad9 | 319 | else |
405e1d83 | 320 | set_function_trace_op = ftrace_ops_list; |
b848914c | 321 | func = ftrace_ops_list->func; |
2f5f6ad9 SR |
322 | } else { |
323 | /* Just use the default ftrace_ops */ | |
405e1d83 | 324 | set_function_trace_op = &ftrace_list_end; |
b848914c | 325 | func = ftrace_ops_list_func; |
2f5f6ad9 | 326 | } |
2b499381 | 327 | |
405e1d83 SRRH |
328 | /* If there's no change, then do nothing more here */ |
329 | if (ftrace_trace_function == func) | |
330 | return; | |
331 | ||
332 | /* | |
333 | * If we are using the list function, it doesn't care | |
334 | * about the function_trace_ops. | |
335 | */ | |
336 | if (func == ftrace_ops_list_func) { | |
337 | ftrace_trace_function = func; | |
338 | /* | |
339 | * Don't even bother setting function_trace_ops, | |
340 | * it would be racy to do so anyway. | |
341 | */ | |
342 | return; | |
343 | } | |
344 | ||
345 | #ifndef CONFIG_DYNAMIC_FTRACE | |
346 | /* | |
347 | * For static tracing, we need to be a bit more careful. | |
348 | * The function change takes affect immediately. Thus, | |
349 | * we need to coorditate the setting of the function_trace_ops | |
350 | * with the setting of the ftrace_trace_function. | |
351 | * | |
352 | * Set the function to the list ops, which will call the | |
353 | * function we want, albeit indirectly, but it handles the | |
354 | * ftrace_ops and doesn't depend on function_trace_op. | |
355 | */ | |
356 | ftrace_trace_function = ftrace_ops_list_func; | |
357 | /* | |
358 | * Make sure all CPUs see this. Yes this is slow, but static | |
359 | * tracing is slow and nasty to have enabled. | |
360 | */ | |
361 | schedule_on_each_cpu(ftrace_sync); | |
362 | /* Now all cpus are using the list ops. */ | |
363 | function_trace_op = set_function_trace_op; | |
364 | /* Make sure the function_trace_op is visible on all CPUs */ | |
365 | smp_wmb(); | |
366 | /* Nasty way to force a rmb on all cpus */ | |
367 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
368 | /* OK, we are all set to update the ftrace_trace_function now! */ | |
369 | #endif /* !CONFIG_DYNAMIC_FTRACE */ | |
370 | ||
491d0dcf | 371 | ftrace_trace_function = func; |
491d0dcf SR |
372 | } |
373 | ||
2b499381 | 374 | static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
3d083395 | 375 | { |
2b499381 | 376 | ops->next = *list; |
16444a8a | 377 | /* |
b848914c | 378 | * We are entering ops into the list but another |
16444a8a ACM |
379 | * CPU might be walking that list. We need to make sure |
380 | * the ops->next pointer is valid before another CPU sees | |
b848914c | 381 | * the ops pointer included into the list. |
16444a8a | 382 | */ |
2b499381 | 383 | rcu_assign_pointer(*list, ops); |
16444a8a ACM |
384 | } |
385 | ||
2b499381 | 386 | static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
16444a8a | 387 | { |
16444a8a | 388 | struct ftrace_ops **p; |
16444a8a ACM |
389 | |
390 | /* | |
3d083395 SR |
391 | * If we are removing the last function, then simply point |
392 | * to the ftrace_stub. | |
16444a8a | 393 | */ |
2b499381 SR |
394 | if (*list == ops && ops->next == &ftrace_list_end) { |
395 | *list = &ftrace_list_end; | |
e6ea44e9 | 396 | return 0; |
16444a8a ACM |
397 | } |
398 | ||
2b499381 | 399 | for (p = list; *p != &ftrace_list_end; p = &(*p)->next) |
16444a8a ACM |
400 | if (*p == ops) |
401 | break; | |
402 | ||
e6ea44e9 SR |
403 | if (*p != ops) |
404 | return -1; | |
16444a8a ACM |
405 | |
406 | *p = (*p)->next; | |
2b499381 SR |
407 | return 0; |
408 | } | |
16444a8a | 409 | |
e248491a JO |
410 | static void add_ftrace_list_ops(struct ftrace_ops **list, |
411 | struct ftrace_ops *main_ops, | |
412 | struct ftrace_ops *ops) | |
413 | { | |
414 | int first = *list == &ftrace_list_end; | |
415 | add_ftrace_ops(list, ops); | |
416 | if (first) | |
417 | add_ftrace_ops(&ftrace_ops_list, main_ops); | |
418 | } | |
419 | ||
420 | static int remove_ftrace_list_ops(struct ftrace_ops **list, | |
421 | struct ftrace_ops *main_ops, | |
422 | struct ftrace_ops *ops) | |
423 | { | |
424 | int ret = remove_ftrace_ops(list, ops); | |
425 | if (!ret && *list == &ftrace_list_end) | |
426 | ret = remove_ftrace_ops(&ftrace_ops_list, main_ops); | |
427 | return ret; | |
428 | } | |
429 | ||
2b499381 SR |
430 | static int __register_ftrace_function(struct ftrace_ops *ops) |
431 | { | |
2b499381 SR |
432 | if (FTRACE_WARN_ON(ops == &global_ops)) |
433 | return -EINVAL; | |
434 | ||
b848914c SR |
435 | if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) |
436 | return -EBUSY; | |
437 | ||
e248491a JO |
438 | /* We don't support both control and global flags set. */ |
439 | if ((ops->flags & FL_GLOBAL_CONTROL_MASK) == FL_GLOBAL_CONTROL_MASK) | |
440 | return -EINVAL; | |
441 | ||
06aeaaea | 442 | #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
08f6fba5 SR |
443 | /* |
444 | * If the ftrace_ops specifies SAVE_REGS, then it only can be used | |
445 | * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set. | |
446 | * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant. | |
447 | */ | |
448 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS && | |
449 | !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)) | |
450 | return -EINVAL; | |
451 | ||
452 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED) | |
453 | ops->flags |= FTRACE_OPS_FL_SAVE_REGS; | |
454 | #endif | |
455 | ||
cdbe61bf SR |
456 | if (!core_kernel_data((unsigned long)ops)) |
457 | ops->flags |= FTRACE_OPS_FL_DYNAMIC; | |
458 | ||
b848914c | 459 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { |
e248491a | 460 | add_ftrace_list_ops(&ftrace_global_list, &global_ops, ops); |
b848914c | 461 | ops->flags |= FTRACE_OPS_FL_ENABLED; |
e248491a JO |
462 | } else if (ops->flags & FTRACE_OPS_FL_CONTROL) { |
463 | if (control_ops_alloc(ops)) | |
464 | return -ENOMEM; | |
465 | add_ftrace_list_ops(&ftrace_control_list, &control_ops, ops); | |
b848914c SR |
466 | } else |
467 | add_ftrace_ops(&ftrace_ops_list, ops); | |
468 | ||
2b499381 SR |
469 | if (ftrace_enabled) |
470 | update_ftrace_function(); | |
471 | ||
472 | return 0; | |
473 | } | |
474 | ||
475 | static int __unregister_ftrace_function(struct ftrace_ops *ops) | |
476 | { | |
477 | int ret; | |
478 | ||
b848914c SR |
479 | if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) |
480 | return -EBUSY; | |
481 | ||
2b499381 SR |
482 | if (FTRACE_WARN_ON(ops == &global_ops)) |
483 | return -EINVAL; | |
484 | ||
b848914c | 485 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { |
e248491a JO |
486 | ret = remove_ftrace_list_ops(&ftrace_global_list, |
487 | &global_ops, ops); | |
b848914c SR |
488 | if (!ret) |
489 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; | |
e248491a JO |
490 | } else if (ops->flags & FTRACE_OPS_FL_CONTROL) { |
491 | ret = remove_ftrace_list_ops(&ftrace_control_list, | |
492 | &control_ops, ops); | |
493 | if (!ret) { | |
494 | /* | |
495 | * The ftrace_ops is now removed from the list, | |
496 | * so there'll be no new users. We must ensure | |
497 | * all current users are done before we free | |
498 | * the control data. | |
7614c3dc SR |
499 | * Note synchronize_sched() is not enough, as we |
500 | * use preempt_disable() to do RCU, but the function | |
501 | * tracer can be called where RCU is not active | |
502 | * (before user_exit()). | |
e248491a | 503 | */ |
7614c3dc | 504 | schedule_on_each_cpu(ftrace_sync); |
e248491a JO |
505 | control_ops_free(ops); |
506 | } | |
b848914c SR |
507 | } else |
508 | ret = remove_ftrace_ops(&ftrace_ops_list, ops); | |
509 | ||
2b499381 SR |
510 | if (ret < 0) |
511 | return ret; | |
b848914c | 512 | |
491d0dcf SR |
513 | if (ftrace_enabled) |
514 | update_ftrace_function(); | |
16444a8a | 515 | |
cdbe61bf SR |
516 | /* |
517 | * Dynamic ops may be freed, we must make sure that all | |
518 | * callers are done before leaving this function. | |
7614c3dc SR |
519 | * |
520 | * Again, normal synchronize_sched() is not good enough. | |
521 | * We need to do a hard force of sched synchronization. | |
cdbe61bf SR |
522 | */ |
523 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC) | |
7614c3dc SR |
524 | schedule_on_each_cpu(ftrace_sync); |
525 | ||
cdbe61bf | 526 | |
e6ea44e9 | 527 | return 0; |
3d083395 SR |
528 | } |
529 | ||
df4fc315 SR |
530 | static void ftrace_update_pid_func(void) |
531 | { | |
491d0dcf | 532 | /* Only do something if we are tracing something */ |
df4fc315 | 533 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 534 | return; |
df4fc315 | 535 | |
491d0dcf | 536 | update_ftrace_function(); |
df4fc315 SR |
537 | } |
538 | ||
493762fc SR |
539 | #ifdef CONFIG_FUNCTION_PROFILER |
540 | struct ftrace_profile { | |
541 | struct hlist_node node; | |
542 | unsigned long ip; | |
543 | unsigned long counter; | |
0706f1c4 SR |
544 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
545 | unsigned long long time; | |
e330b3bc | 546 | unsigned long long time_squared; |
0706f1c4 | 547 | #endif |
8fc0c701 SR |
548 | }; |
549 | ||
493762fc SR |
550 | struct ftrace_profile_page { |
551 | struct ftrace_profile_page *next; | |
552 | unsigned long index; | |
553 | struct ftrace_profile records[]; | |
d61f82d0 SR |
554 | }; |
555 | ||
cafb168a SR |
556 | struct ftrace_profile_stat { |
557 | atomic_t disabled; | |
558 | struct hlist_head *hash; | |
559 | struct ftrace_profile_page *pages; | |
560 | struct ftrace_profile_page *start; | |
561 | struct tracer_stat stat; | |
562 | }; | |
563 | ||
493762fc SR |
564 | #define PROFILE_RECORDS_SIZE \ |
565 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 566 | |
493762fc SR |
567 | #define PROFILES_PER_PAGE \ |
568 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 569 | |
fb9fb015 SR |
570 | static int ftrace_profile_enabled __read_mostly; |
571 | ||
572 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
573 | static DEFINE_MUTEX(ftrace_profile_lock); |
574 | ||
cafb168a | 575 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc | 576 | |
20079ebe NK |
577 | #define FTRACE_PROFILE_HASH_BITS 10 |
578 | #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS) | |
493762fc | 579 | |
bac429f0 SR |
580 | static void * |
581 | function_stat_next(void *v, int idx) | |
582 | { | |
493762fc SR |
583 | struct ftrace_profile *rec = v; |
584 | struct ftrace_profile_page *pg; | |
bac429f0 | 585 | |
493762fc | 586 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
587 | |
588 | again: | |
0296e425 LZ |
589 | if (idx != 0) |
590 | rec++; | |
591 | ||
bac429f0 SR |
592 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
593 | pg = pg->next; | |
594 | if (!pg) | |
595 | return NULL; | |
596 | rec = &pg->records[0]; | |
493762fc SR |
597 | if (!rec->counter) |
598 | goto again; | |
bac429f0 SR |
599 | } |
600 | ||
bac429f0 SR |
601 | return rec; |
602 | } | |
603 | ||
604 | static void *function_stat_start(struct tracer_stat *trace) | |
605 | { | |
cafb168a SR |
606 | struct ftrace_profile_stat *stat = |
607 | container_of(trace, struct ftrace_profile_stat, stat); | |
608 | ||
609 | if (!stat || !stat->start) | |
610 | return NULL; | |
611 | ||
612 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
613 | } |
614 | ||
0706f1c4 SR |
615 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
616 | /* function graph compares on total time */ | |
617 | static int function_stat_cmp(void *p1, void *p2) | |
618 | { | |
619 | struct ftrace_profile *a = p1; | |
620 | struct ftrace_profile *b = p2; | |
621 | ||
622 | if (a->time < b->time) | |
623 | return -1; | |
624 | if (a->time > b->time) | |
625 | return 1; | |
626 | else | |
627 | return 0; | |
628 | } | |
629 | #else | |
630 | /* not function graph compares against hits */ | |
bac429f0 SR |
631 | static int function_stat_cmp(void *p1, void *p2) |
632 | { | |
493762fc SR |
633 | struct ftrace_profile *a = p1; |
634 | struct ftrace_profile *b = p2; | |
bac429f0 SR |
635 | |
636 | if (a->counter < b->counter) | |
637 | return -1; | |
638 | if (a->counter > b->counter) | |
639 | return 1; | |
640 | else | |
641 | return 0; | |
642 | } | |
0706f1c4 | 643 | #endif |
bac429f0 SR |
644 | |
645 | static int function_stat_headers(struct seq_file *m) | |
646 | { | |
0706f1c4 | 647 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b | 648 | seq_printf(m, " Function " |
e330b3bc | 649 | "Hit Time Avg s^2\n" |
34886c8b | 650 | " -------- " |
e330b3bc | 651 | "--- ---- --- ---\n"); |
0706f1c4 | 652 | #else |
bac429f0 SR |
653 | seq_printf(m, " Function Hit\n" |
654 | " -------- ---\n"); | |
0706f1c4 | 655 | #endif |
bac429f0 SR |
656 | return 0; |
657 | } | |
658 | ||
659 | static int function_stat_show(struct seq_file *m, void *v) | |
660 | { | |
493762fc | 661 | struct ftrace_profile *rec = v; |
bac429f0 | 662 | char str[KSYM_SYMBOL_LEN]; |
3aaba20f | 663 | int ret = 0; |
0706f1c4 | 664 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
665 | static struct trace_seq s; |
666 | unsigned long long avg; | |
e330b3bc | 667 | unsigned long long stddev; |
0706f1c4 | 668 | #endif |
3aaba20f LZ |
669 | mutex_lock(&ftrace_profile_lock); |
670 | ||
671 | /* we raced with function_profile_reset() */ | |
672 | if (unlikely(rec->counter == 0)) { | |
673 | ret = -EBUSY; | |
674 | goto out; | |
675 | } | |
bac429f0 SR |
676 | |
677 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
0706f1c4 SR |
678 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
679 | ||
680 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
681 | seq_printf(m, " "); | |
34886c8b SR |
682 | avg = rec->time; |
683 | do_div(avg, rec->counter); | |
684 | ||
e330b3bc CD |
685 | /* Sample standard deviation (s^2) */ |
686 | if (rec->counter <= 1) | |
687 | stddev = 0; | |
688 | else { | |
52d85d76 JL |
689 | /* |
690 | * Apply Welford's method: | |
691 | * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2) | |
692 | */ | |
693 | stddev = rec->counter * rec->time_squared - | |
694 | rec->time * rec->time; | |
695 | ||
e330b3bc CD |
696 | /* |
697 | * Divide only 1000 for ns^2 -> us^2 conversion. | |
698 | * trace_print_graph_duration will divide 1000 again. | |
699 | */ | |
52d85d76 | 700 | do_div(stddev, rec->counter * (rec->counter - 1) * 1000); |
e330b3bc CD |
701 | } |
702 | ||
34886c8b SR |
703 | trace_seq_init(&s); |
704 | trace_print_graph_duration(rec->time, &s); | |
705 | trace_seq_puts(&s, " "); | |
706 | trace_print_graph_duration(avg, &s); | |
e330b3bc CD |
707 | trace_seq_puts(&s, " "); |
708 | trace_print_graph_duration(stddev, &s); | |
0706f1c4 | 709 | trace_print_seq(m, &s); |
0706f1c4 SR |
710 | #endif |
711 | seq_putc(m, '\n'); | |
3aaba20f LZ |
712 | out: |
713 | mutex_unlock(&ftrace_profile_lock); | |
bac429f0 | 714 | |
3aaba20f | 715 | return ret; |
bac429f0 SR |
716 | } |
717 | ||
cafb168a | 718 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 719 | { |
493762fc | 720 | struct ftrace_profile_page *pg; |
bac429f0 | 721 | |
cafb168a | 722 | pg = stat->pages = stat->start; |
bac429f0 | 723 | |
493762fc SR |
724 | while (pg) { |
725 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
726 | pg->index = 0; | |
727 | pg = pg->next; | |
bac429f0 SR |
728 | } |
729 | ||
cafb168a | 730 | memset(stat->hash, 0, |
493762fc SR |
731 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
732 | } | |
bac429f0 | 733 | |
cafb168a | 734 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
735 | { |
736 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
737 | int functions; |
738 | int pages; | |
493762fc | 739 | int i; |
bac429f0 | 740 | |
493762fc | 741 | /* If we already allocated, do nothing */ |
cafb168a | 742 | if (stat->pages) |
493762fc | 743 | return 0; |
bac429f0 | 744 | |
cafb168a SR |
745 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
746 | if (!stat->pages) | |
493762fc | 747 | return -ENOMEM; |
bac429f0 | 748 | |
318e0a73 SR |
749 | #ifdef CONFIG_DYNAMIC_FTRACE |
750 | functions = ftrace_update_tot_cnt; | |
751 | #else | |
752 | /* | |
753 | * We do not know the number of functions that exist because | |
754 | * dynamic tracing is what counts them. With past experience | |
755 | * we have around 20K functions. That should be more than enough. | |
756 | * It is highly unlikely we will execute every function in | |
757 | * the kernel. | |
758 | */ | |
759 | functions = 20000; | |
760 | #endif | |
761 | ||
cafb168a | 762 | pg = stat->start = stat->pages; |
bac429f0 | 763 | |
318e0a73 SR |
764 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
765 | ||
39e30cd1 | 766 | for (i = 1; i < pages; i++) { |
493762fc | 767 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 768 | if (!pg->next) |
318e0a73 | 769 | goto out_free; |
493762fc SR |
770 | pg = pg->next; |
771 | } | |
772 | ||
773 | return 0; | |
318e0a73 SR |
774 | |
775 | out_free: | |
776 | pg = stat->start; | |
777 | while (pg) { | |
778 | unsigned long tmp = (unsigned long)pg; | |
779 | ||
780 | pg = pg->next; | |
781 | free_page(tmp); | |
782 | } | |
783 | ||
318e0a73 SR |
784 | stat->pages = NULL; |
785 | stat->start = NULL; | |
786 | ||
787 | return -ENOMEM; | |
bac429f0 SR |
788 | } |
789 | ||
cafb168a | 790 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 791 | { |
cafb168a | 792 | struct ftrace_profile_stat *stat; |
493762fc | 793 | int size; |
bac429f0 | 794 | |
cafb168a SR |
795 | stat = &per_cpu(ftrace_profile_stats, cpu); |
796 | ||
797 | if (stat->hash) { | |
493762fc | 798 | /* If the profile is already created, simply reset it */ |
cafb168a | 799 | ftrace_profile_reset(stat); |
493762fc SR |
800 | return 0; |
801 | } | |
bac429f0 | 802 | |
493762fc SR |
803 | /* |
804 | * We are profiling all functions, but usually only a few thousand | |
805 | * functions are hit. We'll make a hash of 1024 items. | |
806 | */ | |
807 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 808 | |
cafb168a | 809 | stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
493762fc | 810 | |
cafb168a | 811 | if (!stat->hash) |
493762fc SR |
812 | return -ENOMEM; |
813 | ||
318e0a73 | 814 | /* Preallocate the function profiling pages */ |
cafb168a SR |
815 | if (ftrace_profile_pages_init(stat) < 0) { |
816 | kfree(stat->hash); | |
817 | stat->hash = NULL; | |
493762fc SR |
818 | return -ENOMEM; |
819 | } | |
820 | ||
821 | return 0; | |
bac429f0 SR |
822 | } |
823 | ||
cafb168a SR |
824 | static int ftrace_profile_init(void) |
825 | { | |
826 | int cpu; | |
827 | int ret = 0; | |
828 | ||
829 | for_each_online_cpu(cpu) { | |
830 | ret = ftrace_profile_init_cpu(cpu); | |
831 | if (ret) | |
832 | break; | |
833 | } | |
834 | ||
835 | return ret; | |
836 | } | |
837 | ||
493762fc | 838 | /* interrupts must be disabled */ |
cafb168a SR |
839 | static struct ftrace_profile * |
840 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 841 | { |
493762fc | 842 | struct ftrace_profile *rec; |
bac429f0 | 843 | struct hlist_head *hhd; |
bac429f0 SR |
844 | unsigned long key; |
845 | ||
20079ebe | 846 | key = hash_long(ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 847 | hhd = &stat->hash[key]; |
bac429f0 SR |
848 | |
849 | if (hlist_empty(hhd)) | |
850 | return NULL; | |
851 | ||
1bb539ca | 852 | hlist_for_each_entry_rcu_notrace(rec, hhd, node) { |
bac429f0 | 853 | if (rec->ip == ip) |
493762fc SR |
854 | return rec; |
855 | } | |
856 | ||
857 | return NULL; | |
858 | } | |
859 | ||
cafb168a SR |
860 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
861 | struct ftrace_profile *rec) | |
493762fc SR |
862 | { |
863 | unsigned long key; | |
864 | ||
20079ebe | 865 | key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 866 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
867 | } |
868 | ||
318e0a73 SR |
869 | /* |
870 | * The memory is already allocated, this simply finds a new record to use. | |
871 | */ | |
493762fc | 872 | static struct ftrace_profile * |
318e0a73 | 873 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
874 | { |
875 | struct ftrace_profile *rec = NULL; | |
876 | ||
318e0a73 | 877 | /* prevent recursion (from NMIs) */ |
cafb168a | 878 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
879 | goto out; |
880 | ||
493762fc | 881 | /* |
318e0a73 SR |
882 | * Try to find the function again since an NMI |
883 | * could have added it | |
493762fc | 884 | */ |
cafb168a | 885 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 886 | if (rec) |
cafb168a | 887 | goto out; |
493762fc | 888 | |
cafb168a SR |
889 | if (stat->pages->index == PROFILES_PER_PAGE) { |
890 | if (!stat->pages->next) | |
891 | goto out; | |
892 | stat->pages = stat->pages->next; | |
bac429f0 | 893 | } |
493762fc | 894 | |
cafb168a | 895 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 896 | rec->ip = ip; |
cafb168a | 897 | ftrace_add_profile(stat, rec); |
493762fc | 898 | |
bac429f0 | 899 | out: |
cafb168a | 900 | atomic_dec(&stat->disabled); |
bac429f0 SR |
901 | |
902 | return rec; | |
903 | } | |
904 | ||
905 | static void | |
2f5f6ad9 | 906 | function_profile_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 907 | struct ftrace_ops *ops, struct pt_regs *regs) |
bac429f0 | 908 | { |
cafb168a | 909 | struct ftrace_profile_stat *stat; |
493762fc | 910 | struct ftrace_profile *rec; |
bac429f0 SR |
911 | unsigned long flags; |
912 | ||
913 | if (!ftrace_profile_enabled) | |
914 | return; | |
915 | ||
916 | local_irq_save(flags); | |
cafb168a SR |
917 | |
918 | stat = &__get_cpu_var(ftrace_profile_stats); | |
0f6ce3de | 919 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
920 | goto out; |
921 | ||
922 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 923 | if (!rec) { |
318e0a73 | 924 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
925 | if (!rec) |
926 | goto out; | |
927 | } | |
bac429f0 SR |
928 | |
929 | rec->counter++; | |
930 | out: | |
931 | local_irq_restore(flags); | |
932 | } | |
933 | ||
0706f1c4 SR |
934 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
935 | static int profile_graph_entry(struct ftrace_graph_ent *trace) | |
936 | { | |
a1e2e31d | 937 | function_profile_call(trace->func, 0, NULL, NULL); |
0706f1c4 SR |
938 | return 1; |
939 | } | |
940 | ||
941 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
942 | { | |
cafb168a | 943 | struct ftrace_profile_stat *stat; |
a2a16d6a | 944 | unsigned long long calltime; |
0706f1c4 | 945 | struct ftrace_profile *rec; |
cafb168a | 946 | unsigned long flags; |
0706f1c4 SR |
947 | |
948 | local_irq_save(flags); | |
cafb168a | 949 | stat = &__get_cpu_var(ftrace_profile_stats); |
0f6ce3de | 950 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
951 | goto out; |
952 | ||
37e44bc5 SR |
953 | /* If the calltime was zero'd ignore it */ |
954 | if (!trace->calltime) | |
955 | goto out; | |
956 | ||
a2a16d6a SR |
957 | calltime = trace->rettime - trace->calltime; |
958 | ||
959 | if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) { | |
960 | int index; | |
961 | ||
962 | index = trace->depth; | |
963 | ||
964 | /* Append this call time to the parent time to subtract */ | |
965 | if (index) | |
966 | current->ret_stack[index - 1].subtime += calltime; | |
967 | ||
968 | if (current->ret_stack[index].subtime < calltime) | |
969 | calltime -= current->ret_stack[index].subtime; | |
970 | else | |
971 | calltime = 0; | |
972 | } | |
973 | ||
cafb168a | 974 | rec = ftrace_find_profiled_func(stat, trace->func); |
e330b3bc | 975 | if (rec) { |
a2a16d6a | 976 | rec->time += calltime; |
e330b3bc CD |
977 | rec->time_squared += calltime * calltime; |
978 | } | |
a2a16d6a | 979 | |
cafb168a | 980 | out: |
0706f1c4 SR |
981 | local_irq_restore(flags); |
982 | } | |
983 | ||
984 | static int register_ftrace_profiler(void) | |
985 | { | |
986 | return register_ftrace_graph(&profile_graph_return, | |
987 | &profile_graph_entry); | |
988 | } | |
989 | ||
990 | static void unregister_ftrace_profiler(void) | |
991 | { | |
992 | unregister_ftrace_graph(); | |
993 | } | |
994 | #else | |
bd38c0e6 | 995 | static struct ftrace_ops ftrace_profile_ops __read_mostly = { |
fb9fb015 | 996 | .func = function_profile_call, |
f04f24fb MH |
997 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, |
998 | INIT_REGEX_LOCK(ftrace_profile_ops) | |
bac429f0 SR |
999 | }; |
1000 | ||
0706f1c4 SR |
1001 | static int register_ftrace_profiler(void) |
1002 | { | |
1003 | return register_ftrace_function(&ftrace_profile_ops); | |
1004 | } | |
1005 | ||
1006 | static void unregister_ftrace_profiler(void) | |
1007 | { | |
1008 | unregister_ftrace_function(&ftrace_profile_ops); | |
1009 | } | |
1010 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
1011 | ||
bac429f0 SR |
1012 | static ssize_t |
1013 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
1014 | size_t cnt, loff_t *ppos) | |
1015 | { | |
1016 | unsigned long val; | |
bac429f0 SR |
1017 | int ret; |
1018 | ||
22fe9b54 PH |
1019 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
1020 | if (ret) | |
bac429f0 SR |
1021 | return ret; |
1022 | ||
1023 | val = !!val; | |
1024 | ||
1025 | mutex_lock(&ftrace_profile_lock); | |
1026 | if (ftrace_profile_enabled ^ val) { | |
1027 | if (val) { | |
493762fc SR |
1028 | ret = ftrace_profile_init(); |
1029 | if (ret < 0) { | |
1030 | cnt = ret; | |
1031 | goto out; | |
1032 | } | |
1033 | ||
0706f1c4 SR |
1034 | ret = register_ftrace_profiler(); |
1035 | if (ret < 0) { | |
1036 | cnt = ret; | |
1037 | goto out; | |
1038 | } | |
bac429f0 SR |
1039 | ftrace_profile_enabled = 1; |
1040 | } else { | |
1041 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
1042 | /* |
1043 | * unregister_ftrace_profiler calls stop_machine | |
1044 | * so this acts like an synchronize_sched. | |
1045 | */ | |
0706f1c4 | 1046 | unregister_ftrace_profiler(); |
bac429f0 SR |
1047 | } |
1048 | } | |
493762fc | 1049 | out: |
bac429f0 SR |
1050 | mutex_unlock(&ftrace_profile_lock); |
1051 | ||
cf8517cf | 1052 | *ppos += cnt; |
bac429f0 SR |
1053 | |
1054 | return cnt; | |
1055 | } | |
1056 | ||
493762fc SR |
1057 | static ssize_t |
1058 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
1059 | size_t cnt, loff_t *ppos) | |
1060 | { | |
fb9fb015 | 1061 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
1062 | int r; |
1063 | ||
1064 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
1065 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
1066 | } | |
1067 | ||
bac429f0 SR |
1068 | static const struct file_operations ftrace_profile_fops = { |
1069 | .open = tracing_open_generic, | |
1070 | .read = ftrace_profile_read, | |
1071 | .write = ftrace_profile_write, | |
6038f373 | 1072 | .llseek = default_llseek, |
bac429f0 SR |
1073 | }; |
1074 | ||
cafb168a SR |
1075 | /* used to initialize the real stat files */ |
1076 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
1077 | .name = "functions", |
1078 | .stat_start = function_stat_start, | |
1079 | .stat_next = function_stat_next, | |
1080 | .stat_cmp = function_stat_cmp, | |
1081 | .stat_headers = function_stat_headers, | |
1082 | .stat_show = function_stat_show | |
cafb168a SR |
1083 | }; |
1084 | ||
6ab5d668 | 1085 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 | 1086 | { |
cafb168a | 1087 | struct ftrace_profile_stat *stat; |
bac429f0 | 1088 | struct dentry *entry; |
cafb168a | 1089 | char *name; |
bac429f0 | 1090 | int ret; |
cafb168a SR |
1091 | int cpu; |
1092 | ||
1093 | for_each_possible_cpu(cpu) { | |
1094 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
1095 | ||
1096 | /* allocate enough for function name + cpu number */ | |
1097 | name = kmalloc(32, GFP_KERNEL); | |
1098 | if (!name) { | |
1099 | /* | |
1100 | * The files created are permanent, if something happens | |
1101 | * we still do not free memory. | |
1102 | */ | |
cafb168a SR |
1103 | WARN(1, |
1104 | "Could not allocate stat file for cpu %d\n", | |
1105 | cpu); | |
1106 | return; | |
1107 | } | |
1108 | stat->stat = function_stats; | |
1109 | snprintf(name, 32, "function%d", cpu); | |
1110 | stat->stat.name = name; | |
1111 | ret = register_stat_tracer(&stat->stat); | |
1112 | if (ret) { | |
1113 | WARN(1, | |
1114 | "Could not register function stat for cpu %d\n", | |
1115 | cpu); | |
1116 | kfree(name); | |
1117 | return; | |
1118 | } | |
bac429f0 SR |
1119 | } |
1120 | ||
1121 | entry = debugfs_create_file("function_profile_enabled", 0644, | |
1122 | d_tracer, NULL, &ftrace_profile_fops); | |
1123 | if (!entry) | |
1124 | pr_warning("Could not create debugfs " | |
1125 | "'function_profile_enabled' entry\n"); | |
1126 | } | |
1127 | ||
bac429f0 | 1128 | #else /* CONFIG_FUNCTION_PROFILER */ |
6ab5d668 | 1129 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 SR |
1130 | { |
1131 | } | |
bac429f0 SR |
1132 | #endif /* CONFIG_FUNCTION_PROFILER */ |
1133 | ||
493762fc SR |
1134 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; |
1135 | ||
1136 | #ifdef CONFIG_DYNAMIC_FTRACE | |
1137 | ||
1138 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD | |
1139 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
1140 | #endif | |
1141 | ||
1142 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; | |
1143 | ||
1144 | struct ftrace_func_probe { | |
1145 | struct hlist_node node; | |
1146 | struct ftrace_probe_ops *ops; | |
1147 | unsigned long flags; | |
1148 | unsigned long ip; | |
1149 | void *data; | |
7818b388 | 1150 | struct list_head free_list; |
493762fc SR |
1151 | }; |
1152 | ||
b448c4e3 SR |
1153 | struct ftrace_func_entry { |
1154 | struct hlist_node hlist; | |
1155 | unsigned long ip; | |
1156 | }; | |
1157 | ||
1158 | struct ftrace_hash { | |
1159 | unsigned long size_bits; | |
1160 | struct hlist_head *buckets; | |
1161 | unsigned long count; | |
07fd5515 | 1162 | struct rcu_head rcu; |
b448c4e3 SR |
1163 | }; |
1164 | ||
33dc9b12 SR |
1165 | /* |
1166 | * We make these constant because no one should touch them, | |
1167 | * but they are used as the default "empty hash", to avoid allocating | |
1168 | * it all the time. These are in a read only section such that if | |
1169 | * anyone does try to modify it, it will cause an exception. | |
1170 | */ | |
1171 | static const struct hlist_head empty_buckets[1]; | |
1172 | static const struct ftrace_hash empty_hash = { | |
1173 | .buckets = (struct hlist_head *)empty_buckets, | |
1cf41dd7 | 1174 | }; |
33dc9b12 | 1175 | #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash) |
493762fc | 1176 | |
2b499381 | 1177 | static struct ftrace_ops global_ops = { |
f45948e8 | 1178 | .func = ftrace_stub, |
33dc9b12 SR |
1179 | .notrace_hash = EMPTY_HASH, |
1180 | .filter_hash = EMPTY_HASH, | |
f04f24fb MH |
1181 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, |
1182 | INIT_REGEX_LOCK(global_ops) | |
f45948e8 SR |
1183 | }; |
1184 | ||
493762fc SR |
1185 | struct ftrace_page { |
1186 | struct ftrace_page *next; | |
a7900875 | 1187 | struct dyn_ftrace *records; |
493762fc | 1188 | int index; |
a7900875 | 1189 | int size; |
493762fc SR |
1190 | }; |
1191 | ||
85ae32ae SR |
1192 | static struct ftrace_page *ftrace_new_pgs; |
1193 | ||
a7900875 SR |
1194 | #define ENTRY_SIZE sizeof(struct dyn_ftrace) |
1195 | #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE) | |
493762fc SR |
1196 | |
1197 | /* estimate from running different kernels */ | |
1198 | #define NR_TO_INIT 10000 | |
1199 | ||
1200 | static struct ftrace_page *ftrace_pages_start; | |
1201 | static struct ftrace_page *ftrace_pages; | |
1202 | ||
06a51d93 SR |
1203 | static bool ftrace_hash_empty(struct ftrace_hash *hash) |
1204 | { | |
1205 | return !hash || !hash->count; | |
1206 | } | |
1207 | ||
b448c4e3 SR |
1208 | static struct ftrace_func_entry * |
1209 | ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
1210 | { | |
1211 | unsigned long key; | |
1212 | struct ftrace_func_entry *entry; | |
1213 | struct hlist_head *hhd; | |
b448c4e3 | 1214 | |
06a51d93 | 1215 | if (ftrace_hash_empty(hash)) |
b448c4e3 SR |
1216 | return NULL; |
1217 | ||
1218 | if (hash->size_bits > 0) | |
1219 | key = hash_long(ip, hash->size_bits); | |
1220 | else | |
1221 | key = 0; | |
1222 | ||
1223 | hhd = &hash->buckets[key]; | |
1224 | ||
1bb539ca | 1225 | hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) { |
b448c4e3 SR |
1226 | if (entry->ip == ip) |
1227 | return entry; | |
1228 | } | |
1229 | return NULL; | |
1230 | } | |
1231 | ||
33dc9b12 SR |
1232 | static void __add_hash_entry(struct ftrace_hash *hash, |
1233 | struct ftrace_func_entry *entry) | |
b448c4e3 | 1234 | { |
b448c4e3 SR |
1235 | struct hlist_head *hhd; |
1236 | unsigned long key; | |
1237 | ||
b448c4e3 | 1238 | if (hash->size_bits) |
33dc9b12 | 1239 | key = hash_long(entry->ip, hash->size_bits); |
b448c4e3 SR |
1240 | else |
1241 | key = 0; | |
1242 | ||
b448c4e3 SR |
1243 | hhd = &hash->buckets[key]; |
1244 | hlist_add_head(&entry->hlist, hhd); | |
1245 | hash->count++; | |
33dc9b12 SR |
1246 | } |
1247 | ||
1248 | static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip) | |
1249 | { | |
1250 | struct ftrace_func_entry *entry; | |
1251 | ||
1252 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1253 | if (!entry) | |
1254 | return -ENOMEM; | |
1255 | ||
1256 | entry->ip = ip; | |
1257 | __add_hash_entry(hash, entry); | |
b448c4e3 SR |
1258 | |
1259 | return 0; | |
1260 | } | |
1261 | ||
1262 | static void | |
33dc9b12 | 1263 | free_hash_entry(struct ftrace_hash *hash, |
b448c4e3 SR |
1264 | struct ftrace_func_entry *entry) |
1265 | { | |
1266 | hlist_del(&entry->hlist); | |
1267 | kfree(entry); | |
1268 | hash->count--; | |
1269 | } | |
1270 | ||
33dc9b12 SR |
1271 | static void |
1272 | remove_hash_entry(struct ftrace_hash *hash, | |
1273 | struct ftrace_func_entry *entry) | |
1274 | { | |
1275 | hlist_del(&entry->hlist); | |
1276 | hash->count--; | |
1277 | } | |
1278 | ||
b448c4e3 SR |
1279 | static void ftrace_hash_clear(struct ftrace_hash *hash) |
1280 | { | |
1281 | struct hlist_head *hhd; | |
b67bfe0d | 1282 | struct hlist_node *tn; |
b448c4e3 SR |
1283 | struct ftrace_func_entry *entry; |
1284 | int size = 1 << hash->size_bits; | |
1285 | int i; | |
1286 | ||
33dc9b12 SR |
1287 | if (!hash->count) |
1288 | return; | |
1289 | ||
b448c4e3 SR |
1290 | for (i = 0; i < size; i++) { |
1291 | hhd = &hash->buckets[i]; | |
b67bfe0d | 1292 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) |
33dc9b12 | 1293 | free_hash_entry(hash, entry); |
b448c4e3 SR |
1294 | } |
1295 | FTRACE_WARN_ON(hash->count); | |
1296 | } | |
1297 | ||
33dc9b12 SR |
1298 | static void free_ftrace_hash(struct ftrace_hash *hash) |
1299 | { | |
1300 | if (!hash || hash == EMPTY_HASH) | |
1301 | return; | |
1302 | ftrace_hash_clear(hash); | |
1303 | kfree(hash->buckets); | |
1304 | kfree(hash); | |
1305 | } | |
1306 | ||
07fd5515 SR |
1307 | static void __free_ftrace_hash_rcu(struct rcu_head *rcu) |
1308 | { | |
1309 | struct ftrace_hash *hash; | |
1310 | ||
1311 | hash = container_of(rcu, struct ftrace_hash, rcu); | |
1312 | free_ftrace_hash(hash); | |
1313 | } | |
1314 | ||
1315 | static void free_ftrace_hash_rcu(struct ftrace_hash *hash) | |
1316 | { | |
1317 | if (!hash || hash == EMPTY_HASH) | |
1318 | return; | |
1319 | call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu); | |
1320 | } | |
1321 | ||
5500fa51 JO |
1322 | void ftrace_free_filter(struct ftrace_ops *ops) |
1323 | { | |
f04f24fb | 1324 | ftrace_ops_init(ops); |
5500fa51 JO |
1325 | free_ftrace_hash(ops->filter_hash); |
1326 | free_ftrace_hash(ops->notrace_hash); | |
1327 | } | |
1328 | ||
33dc9b12 SR |
1329 | static struct ftrace_hash *alloc_ftrace_hash(int size_bits) |
1330 | { | |
1331 | struct ftrace_hash *hash; | |
1332 | int size; | |
1333 | ||
1334 | hash = kzalloc(sizeof(*hash), GFP_KERNEL); | |
1335 | if (!hash) | |
1336 | return NULL; | |
1337 | ||
1338 | size = 1 << size_bits; | |
47b0edcb | 1339 | hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL); |
33dc9b12 SR |
1340 | |
1341 | if (!hash->buckets) { | |
1342 | kfree(hash); | |
1343 | return NULL; | |
1344 | } | |
1345 | ||
1346 | hash->size_bits = size_bits; | |
1347 | ||
1348 | return hash; | |
1349 | } | |
1350 | ||
1351 | static struct ftrace_hash * | |
1352 | alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) | |
1353 | { | |
1354 | struct ftrace_func_entry *entry; | |
1355 | struct ftrace_hash *new_hash; | |
33dc9b12 SR |
1356 | int size; |
1357 | int ret; | |
1358 | int i; | |
1359 | ||
1360 | new_hash = alloc_ftrace_hash(size_bits); | |
1361 | if (!new_hash) | |
1362 | return NULL; | |
1363 | ||
1364 | /* Empty hash? */ | |
06a51d93 | 1365 | if (ftrace_hash_empty(hash)) |
33dc9b12 SR |
1366 | return new_hash; |
1367 | ||
1368 | size = 1 << hash->size_bits; | |
1369 | for (i = 0; i < size; i++) { | |
b67bfe0d | 1370 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { |
33dc9b12 SR |
1371 | ret = add_hash_entry(new_hash, entry->ip); |
1372 | if (ret < 0) | |
1373 | goto free_hash; | |
1374 | } | |
1375 | } | |
1376 | ||
1377 | FTRACE_WARN_ON(new_hash->count != hash->count); | |
1378 | ||
1379 | return new_hash; | |
1380 | ||
1381 | free_hash: | |
1382 | free_ftrace_hash(new_hash); | |
1383 | return NULL; | |
1384 | } | |
1385 | ||
41fb61c2 SR |
1386 | static void |
1387 | ftrace_hash_rec_disable(struct ftrace_ops *ops, int filter_hash); | |
1388 | static void | |
1389 | ftrace_hash_rec_enable(struct ftrace_ops *ops, int filter_hash); | |
1390 | ||
33dc9b12 | 1391 | static int |
41fb61c2 SR |
1392 | ftrace_hash_move(struct ftrace_ops *ops, int enable, |
1393 | struct ftrace_hash **dst, struct ftrace_hash *src) | |
33dc9b12 SR |
1394 | { |
1395 | struct ftrace_func_entry *entry; | |
b67bfe0d | 1396 | struct hlist_node *tn; |
33dc9b12 | 1397 | struct hlist_head *hhd; |
07fd5515 SR |
1398 | struct ftrace_hash *old_hash; |
1399 | struct ftrace_hash *new_hash; | |
33dc9b12 SR |
1400 | int size = src->count; |
1401 | int bits = 0; | |
41fb61c2 | 1402 | int ret; |
33dc9b12 SR |
1403 | int i; |
1404 | ||
41fb61c2 SR |
1405 | /* |
1406 | * Remove the current set, update the hash and add | |
1407 | * them back. | |
1408 | */ | |
1409 | ftrace_hash_rec_disable(ops, enable); | |
1410 | ||
33dc9b12 SR |
1411 | /* |
1412 | * If the new source is empty, just free dst and assign it | |
1413 | * the empty_hash. | |
1414 | */ | |
1415 | if (!src->count) { | |
07fd5515 SR |
1416 | free_ftrace_hash_rcu(*dst); |
1417 | rcu_assign_pointer(*dst, EMPTY_HASH); | |
d4d34b98 SR |
1418 | /* still need to update the function records */ |
1419 | ret = 0; | |
1420 | goto out; | |
33dc9b12 SR |
1421 | } |
1422 | ||
33dc9b12 SR |
1423 | /* |
1424 | * Make the hash size about 1/2 the # found | |
1425 | */ | |
1426 | for (size /= 2; size; size >>= 1) | |
1427 | bits++; | |
1428 | ||
1429 | /* Don't allocate too much */ | |
1430 | if (bits > FTRACE_HASH_MAX_BITS) | |
1431 | bits = FTRACE_HASH_MAX_BITS; | |
1432 | ||
41fb61c2 | 1433 | ret = -ENOMEM; |
07fd5515 SR |
1434 | new_hash = alloc_ftrace_hash(bits); |
1435 | if (!new_hash) | |
41fb61c2 | 1436 | goto out; |
33dc9b12 SR |
1437 | |
1438 | size = 1 << src->size_bits; | |
1439 | for (i = 0; i < size; i++) { | |
1440 | hhd = &src->buckets[i]; | |
b67bfe0d | 1441 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) { |
33dc9b12 | 1442 | remove_hash_entry(src, entry); |
07fd5515 | 1443 | __add_hash_entry(new_hash, entry); |
33dc9b12 SR |
1444 | } |
1445 | } | |
1446 | ||
07fd5515 SR |
1447 | old_hash = *dst; |
1448 | rcu_assign_pointer(*dst, new_hash); | |
1449 | free_ftrace_hash_rcu(old_hash); | |
1450 | ||
41fb61c2 SR |
1451 | ret = 0; |
1452 | out: | |
1453 | /* | |
1454 | * Enable regardless of ret: | |
1455 | * On success, we enable the new hash. | |
1456 | * On failure, we re-enable the original hash. | |
1457 | */ | |
1458 | ftrace_hash_rec_enable(ops, enable); | |
1459 | ||
1460 | return ret; | |
33dc9b12 SR |
1461 | } |
1462 | ||
b848914c SR |
1463 | /* |
1464 | * Test the hashes for this ops to see if we want to call | |
1465 | * the ops->func or not. | |
1466 | * | |
1467 | * It's a match if the ip is in the ops->filter_hash or | |
1468 | * the filter_hash does not exist or is empty, | |
1469 | * AND | |
1470 | * the ip is not in the ops->notrace_hash. | |
cdbe61bf SR |
1471 | * |
1472 | * This needs to be called with preemption disabled as | |
1473 | * the hashes are freed with call_rcu_sched(). | |
b848914c SR |
1474 | */ |
1475 | static int | |
195a8afc | 1476 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
b848914c SR |
1477 | { |
1478 | struct ftrace_hash *filter_hash; | |
1479 | struct ftrace_hash *notrace_hash; | |
1480 | int ret; | |
1481 | ||
195a8afc SRRH |
1482 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
1483 | /* | |
1484 | * There's a small race when adding ops that the ftrace handler | |
1485 | * that wants regs, may be called without them. We can not | |
1486 | * allow that handler to be called if regs is NULL. | |
1487 | */ | |
1488 | if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS)) | |
1489 | return 0; | |
1490 | #endif | |
1491 | ||
1bb539ca SR |
1492 | filter_hash = rcu_dereference_raw_notrace(ops->filter_hash); |
1493 | notrace_hash = rcu_dereference_raw_notrace(ops->notrace_hash); | |
b848914c | 1494 | |
06a51d93 | 1495 | if ((ftrace_hash_empty(filter_hash) || |
b848914c | 1496 | ftrace_lookup_ip(filter_hash, ip)) && |
06a51d93 | 1497 | (ftrace_hash_empty(notrace_hash) || |
b848914c SR |
1498 | !ftrace_lookup_ip(notrace_hash, ip))) |
1499 | ret = 1; | |
1500 | else | |
1501 | ret = 0; | |
b848914c SR |
1502 | |
1503 | return ret; | |
1504 | } | |
1505 | ||
493762fc SR |
1506 | /* |
1507 | * This is a double for. Do not use 'break' to break out of the loop, | |
1508 | * you must use a goto. | |
1509 | */ | |
1510 | #define do_for_each_ftrace_rec(pg, rec) \ | |
1511 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
1512 | int _____i; \ | |
1513 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
1514 | rec = &pg->records[_____i]; | |
1515 | ||
1516 | #define while_for_each_ftrace_rec() \ | |
1517 | } \ | |
1518 | } | |
1519 | ||
5855fead SR |
1520 | |
1521 | static int ftrace_cmp_recs(const void *a, const void *b) | |
1522 | { | |
a650e02a SR |
1523 | const struct dyn_ftrace *key = a; |
1524 | const struct dyn_ftrace *rec = b; | |
5855fead | 1525 | |
a650e02a | 1526 | if (key->flags < rec->ip) |
5855fead | 1527 | return -1; |
a650e02a SR |
1528 | if (key->ip >= rec->ip + MCOUNT_INSN_SIZE) |
1529 | return 1; | |
5855fead SR |
1530 | return 0; |
1531 | } | |
1532 | ||
f0cf973a | 1533 | static unsigned long ftrace_location_range(unsigned long start, unsigned long end) |
c88fd863 SR |
1534 | { |
1535 | struct ftrace_page *pg; | |
1536 | struct dyn_ftrace *rec; | |
5855fead | 1537 | struct dyn_ftrace key; |
c88fd863 | 1538 | |
a650e02a SR |
1539 | key.ip = start; |
1540 | key.flags = end; /* overload flags, as it is unsigned long */ | |
5855fead SR |
1541 | |
1542 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
a650e02a SR |
1543 | if (end < pg->records[0].ip || |
1544 | start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) | |
9644302e | 1545 | continue; |
5855fead SR |
1546 | rec = bsearch(&key, pg->records, pg->index, |
1547 | sizeof(struct dyn_ftrace), | |
1548 | ftrace_cmp_recs); | |
1549 | if (rec) | |
f0cf973a | 1550 | return rec->ip; |
5855fead | 1551 | } |
c88fd863 SR |
1552 | |
1553 | return 0; | |
1554 | } | |
1555 | ||
a650e02a SR |
1556 | /** |
1557 | * ftrace_location - return true if the ip giving is a traced location | |
1558 | * @ip: the instruction pointer to check | |
1559 | * | |
f0cf973a | 1560 | * Returns rec->ip if @ip given is a pointer to a ftrace location. |
a650e02a SR |
1561 | * That is, the instruction that is either a NOP or call to |
1562 | * the function tracer. It checks the ftrace internal tables to | |
1563 | * determine if the address belongs or not. | |
1564 | */ | |
f0cf973a | 1565 | unsigned long ftrace_location(unsigned long ip) |
a650e02a SR |
1566 | { |
1567 | return ftrace_location_range(ip, ip); | |
1568 | } | |
1569 | ||
1570 | /** | |
1571 | * ftrace_text_reserved - return true if range contains an ftrace location | |
1572 | * @start: start of range to search | |
1573 | * @end: end of range to search (inclusive). @end points to the last byte to check. | |
1574 | * | |
1575 | * Returns 1 if @start and @end contains a ftrace location. | |
1576 | * That is, the instruction that is either a NOP or call to | |
1577 | * the function tracer. It checks the ftrace internal tables to | |
1578 | * determine if the address belongs or not. | |
1579 | */ | |
1580 | int ftrace_text_reserved(void *start, void *end) | |
1581 | { | |
f0cf973a SR |
1582 | unsigned long ret; |
1583 | ||
1584 | ret = ftrace_location_range((unsigned long)start, | |
1585 | (unsigned long)end); | |
1586 | ||
1587 | return (int)!!ret; | |
a650e02a SR |
1588 | } |
1589 | ||
ed926f9b SR |
1590 | static void __ftrace_hash_rec_update(struct ftrace_ops *ops, |
1591 | int filter_hash, | |
1592 | bool inc) | |
1593 | { | |
1594 | struct ftrace_hash *hash; | |
1595 | struct ftrace_hash *other_hash; | |
1596 | struct ftrace_page *pg; | |
1597 | struct dyn_ftrace *rec; | |
1598 | int count = 0; | |
1599 | int all = 0; | |
1600 | ||
1601 | /* Only update if the ops has been registered */ | |
1602 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
1603 | return; | |
1604 | ||
1605 | /* | |
1606 | * In the filter_hash case: | |
1607 | * If the count is zero, we update all records. | |
1608 | * Otherwise we just update the items in the hash. | |
1609 | * | |
1610 | * In the notrace_hash case: | |
1611 | * We enable the update in the hash. | |
1612 | * As disabling notrace means enabling the tracing, | |
1613 | * and enabling notrace means disabling, the inc variable | |
1614 | * gets inversed. | |
1615 | */ | |
1616 | if (filter_hash) { | |
1617 | hash = ops->filter_hash; | |
1618 | other_hash = ops->notrace_hash; | |
06a51d93 | 1619 | if (ftrace_hash_empty(hash)) |
ed926f9b SR |
1620 | all = 1; |
1621 | } else { | |
1622 | inc = !inc; | |
1623 | hash = ops->notrace_hash; | |
1624 | other_hash = ops->filter_hash; | |
1625 | /* | |
1626 | * If the notrace hash has no items, | |
1627 | * then there's nothing to do. | |
1628 | */ | |
06a51d93 | 1629 | if (ftrace_hash_empty(hash)) |
ed926f9b SR |
1630 | return; |
1631 | } | |
1632 | ||
1633 | do_for_each_ftrace_rec(pg, rec) { | |
1634 | int in_other_hash = 0; | |
1635 | int in_hash = 0; | |
1636 | int match = 0; | |
1637 | ||
1638 | if (all) { | |
1639 | /* | |
1640 | * Only the filter_hash affects all records. | |
1641 | * Update if the record is not in the notrace hash. | |
1642 | */ | |
b848914c | 1643 | if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) |
ed926f9b SR |
1644 | match = 1; |
1645 | } else { | |
06a51d93 SR |
1646 | in_hash = !!ftrace_lookup_ip(hash, rec->ip); |
1647 | in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip); | |
ed926f9b SR |
1648 | |
1649 | /* | |
1650 | * | |
1651 | */ | |
1652 | if (filter_hash && in_hash && !in_other_hash) | |
1653 | match = 1; | |
1654 | else if (!filter_hash && in_hash && | |
06a51d93 | 1655 | (in_other_hash || ftrace_hash_empty(other_hash))) |
ed926f9b SR |
1656 | match = 1; |
1657 | } | |
1658 | if (!match) | |
1659 | continue; | |
1660 | ||
1661 | if (inc) { | |
1662 | rec->flags++; | |
1663 | if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == FTRACE_REF_MAX)) | |
1664 | return; | |
08f6fba5 SR |
1665 | /* |
1666 | * If any ops wants regs saved for this function | |
1667 | * then all ops will get saved regs. | |
1668 | */ | |
1669 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) | |
1670 | rec->flags |= FTRACE_FL_REGS; | |
ed926f9b SR |
1671 | } else { |
1672 | if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == 0)) | |
1673 | return; | |
1674 | rec->flags--; | |
1675 | } | |
1676 | count++; | |
1677 | /* Shortcut, if we handled all records, we are done. */ | |
1678 | if (!all && count == hash->count) | |
1679 | return; | |
1680 | } while_for_each_ftrace_rec(); | |
1681 | } | |
1682 | ||
1683 | static void ftrace_hash_rec_disable(struct ftrace_ops *ops, | |
1684 | int filter_hash) | |
1685 | { | |
1686 | __ftrace_hash_rec_update(ops, filter_hash, 0); | |
1687 | } | |
1688 | ||
1689 | static void ftrace_hash_rec_enable(struct ftrace_ops *ops, | |
1690 | int filter_hash) | |
1691 | { | |
1692 | __ftrace_hash_rec_update(ops, filter_hash, 1); | |
1693 | } | |
1694 | ||
b17e8a37 SR |
1695 | static void print_ip_ins(const char *fmt, unsigned char *p) |
1696 | { | |
1697 | int i; | |
1698 | ||
1699 | printk(KERN_CONT "%s", fmt); | |
1700 | ||
1701 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
1702 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
1703 | } | |
1704 | ||
c88fd863 SR |
1705 | /** |
1706 | * ftrace_bug - report and shutdown function tracer | |
1707 | * @failed: The failed type (EFAULT, EINVAL, EPERM) | |
1708 | * @ip: The address that failed | |
1709 | * | |
1710 | * The arch code that enables or disables the function tracing | |
1711 | * can call ftrace_bug() when it has detected a problem in | |
1712 | * modifying the code. @failed should be one of either: | |
1713 | * EFAULT - if the problem happens on reading the @ip address | |
1714 | * EINVAL - if what is read at @ip is not what was expected | |
1715 | * EPERM - if the problem happens on writting to the @ip address | |
1716 | */ | |
1717 | void ftrace_bug(int failed, unsigned long ip) | |
b17e8a37 SR |
1718 | { |
1719 | switch (failed) { | |
1720 | case -EFAULT: | |
1721 | FTRACE_WARN_ON_ONCE(1); | |
1722 | pr_info("ftrace faulted on modifying "); | |
1723 | print_ip_sym(ip); | |
1724 | break; | |
1725 | case -EINVAL: | |
1726 | FTRACE_WARN_ON_ONCE(1); | |
1727 | pr_info("ftrace failed to modify "); | |
1728 | print_ip_sym(ip); | |
b17e8a37 | 1729 | print_ip_ins(" actual: ", (unsigned char *)ip); |
b17e8a37 SR |
1730 | printk(KERN_CONT "\n"); |
1731 | break; | |
1732 | case -EPERM: | |
1733 | FTRACE_WARN_ON_ONCE(1); | |
1734 | pr_info("ftrace faulted on writing "); | |
1735 | print_ip_sym(ip); | |
1736 | break; | |
1737 | default: | |
1738 | FTRACE_WARN_ON_ONCE(1); | |
1739 | pr_info("ftrace faulted on unknown error "); | |
1740 | print_ip_sym(ip); | |
1741 | } | |
1742 | } | |
1743 | ||
c88fd863 | 1744 | static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update) |
5072c59f | 1745 | { |
64fbcd16 | 1746 | unsigned long flag = 0UL; |
e7d3737e | 1747 | |
982c350b | 1748 | /* |
30fb6aa7 | 1749 | * If we are updating calls: |
982c350b | 1750 | * |
ed926f9b SR |
1751 | * If the record has a ref count, then we need to enable it |
1752 | * because someone is using it. | |
982c350b | 1753 | * |
ed926f9b SR |
1754 | * Otherwise we make sure its disabled. |
1755 | * | |
30fb6aa7 | 1756 | * If we are disabling calls, then disable all records that |
ed926f9b | 1757 | * are enabled. |
982c350b | 1758 | */ |
c88fd863 | 1759 | if (enable && (rec->flags & ~FTRACE_FL_MASK)) |
ed926f9b | 1760 | flag = FTRACE_FL_ENABLED; |
982c350b | 1761 | |
08f6fba5 SR |
1762 | /* |
1763 | * If enabling and the REGS flag does not match the REGS_EN, then | |
1764 | * do not ignore this record. Set flags to fail the compare against | |
1765 | * ENABLED. | |
1766 | */ | |
1767 | if (flag && | |
1768 | (!(rec->flags & FTRACE_FL_REGS) != !(rec->flags & FTRACE_FL_REGS_EN))) | |
1769 | flag |= FTRACE_FL_REGS; | |
1770 | ||
64fbcd16 XG |
1771 | /* If the state of this record hasn't changed, then do nothing */ |
1772 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
c88fd863 | 1773 | return FTRACE_UPDATE_IGNORE; |
982c350b | 1774 | |
64fbcd16 | 1775 | if (flag) { |
08f6fba5 SR |
1776 | /* Save off if rec is being enabled (for return value) */ |
1777 | flag ^= rec->flags & FTRACE_FL_ENABLED; | |
1778 | ||
1779 | if (update) { | |
c88fd863 | 1780 | rec->flags |= FTRACE_FL_ENABLED; |
08f6fba5 SR |
1781 | if (flag & FTRACE_FL_REGS) { |
1782 | if (rec->flags & FTRACE_FL_REGS) | |
1783 | rec->flags |= FTRACE_FL_REGS_EN; | |
1784 | else | |
1785 | rec->flags &= ~FTRACE_FL_REGS_EN; | |
1786 | } | |
1787 | } | |
1788 | ||
1789 | /* | |
1790 | * If this record is being updated from a nop, then | |
1791 | * return UPDATE_MAKE_CALL. | |
1792 | * Otherwise, if the EN flag is set, then return | |
1793 | * UPDATE_MODIFY_CALL_REGS to tell the caller to convert | |
1794 | * from the non-save regs, to a save regs function. | |
1795 | * Otherwise, | |
1796 | * return UPDATE_MODIFY_CALL to tell the caller to convert | |
1797 | * from the save regs, to a non-save regs function. | |
1798 | */ | |
1799 | if (flag & FTRACE_FL_ENABLED) | |
1800 | return FTRACE_UPDATE_MAKE_CALL; | |
1801 | else if (rec->flags & FTRACE_FL_REGS_EN) | |
1802 | return FTRACE_UPDATE_MODIFY_CALL_REGS; | |
1803 | else | |
1804 | return FTRACE_UPDATE_MODIFY_CALL; | |
c88fd863 SR |
1805 | } |
1806 | ||
08f6fba5 SR |
1807 | if (update) { |
1808 | /* If there's no more users, clear all flags */ | |
1809 | if (!(rec->flags & ~FTRACE_FL_MASK)) | |
1810 | rec->flags = 0; | |
1811 | else | |
1812 | /* Just disable the record (keep REGS state) */ | |
1813 | rec->flags &= ~FTRACE_FL_ENABLED; | |
1814 | } | |
c88fd863 SR |
1815 | |
1816 | return FTRACE_UPDATE_MAKE_NOP; | |
1817 | } | |
1818 | ||
1819 | /** | |
1820 | * ftrace_update_record, set a record that now is tracing or not | |
1821 | * @rec: the record to update | |
1822 | * @enable: set to 1 if the record is tracing, zero to force disable | |
1823 | * | |
1824 | * The records that represent all functions that can be traced need | |
1825 | * to be updated when tracing has been enabled. | |
1826 | */ | |
1827 | int ftrace_update_record(struct dyn_ftrace *rec, int enable) | |
1828 | { | |
1829 | return ftrace_check_record(rec, enable, 1); | |
1830 | } | |
1831 | ||
1832 | /** | |
1833 | * ftrace_test_record, check if the record has been enabled or not | |
1834 | * @rec: the record to test | |
1835 | * @enable: set to 1 to check if enabled, 0 if it is disabled | |
1836 | * | |
1837 | * The arch code may need to test if a record is already set to | |
1838 | * tracing to determine how to modify the function code that it | |
1839 | * represents. | |
1840 | */ | |
1841 | int ftrace_test_record(struct dyn_ftrace *rec, int enable) | |
1842 | { | |
1843 | return ftrace_check_record(rec, enable, 0); | |
1844 | } | |
1845 | ||
1846 | static int | |
1847 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) | |
1848 | { | |
08f6fba5 | 1849 | unsigned long ftrace_old_addr; |
c88fd863 SR |
1850 | unsigned long ftrace_addr; |
1851 | int ret; | |
1852 | ||
c88fd863 SR |
1853 | ret = ftrace_update_record(rec, enable); |
1854 | ||
08f6fba5 SR |
1855 | if (rec->flags & FTRACE_FL_REGS) |
1856 | ftrace_addr = (unsigned long)FTRACE_REGS_ADDR; | |
1857 | else | |
1858 | ftrace_addr = (unsigned long)FTRACE_ADDR; | |
1859 | ||
c88fd863 SR |
1860 | switch (ret) { |
1861 | case FTRACE_UPDATE_IGNORE: | |
1862 | return 0; | |
1863 | ||
1864 | case FTRACE_UPDATE_MAKE_CALL: | |
64fbcd16 | 1865 | return ftrace_make_call(rec, ftrace_addr); |
c88fd863 SR |
1866 | |
1867 | case FTRACE_UPDATE_MAKE_NOP: | |
1868 | return ftrace_make_nop(NULL, rec, ftrace_addr); | |
08f6fba5 SR |
1869 | |
1870 | case FTRACE_UPDATE_MODIFY_CALL_REGS: | |
1871 | case FTRACE_UPDATE_MODIFY_CALL: | |
1872 | if (rec->flags & FTRACE_FL_REGS) | |
1873 | ftrace_old_addr = (unsigned long)FTRACE_ADDR; | |
1874 | else | |
1875 | ftrace_old_addr = (unsigned long)FTRACE_REGS_ADDR; | |
1876 | ||
1877 | return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr); | |
5072c59f SR |
1878 | } |
1879 | ||
c88fd863 | 1880 | return -1; /* unknow ftrace bug */ |
5072c59f SR |
1881 | } |
1882 | ||
e4f5d544 | 1883 | void __weak ftrace_replace_code(int enable) |
3c1720f0 | 1884 | { |
3c1720f0 SR |
1885 | struct dyn_ftrace *rec; |
1886 | struct ftrace_page *pg; | |
6a24a244 | 1887 | int failed; |
3c1720f0 | 1888 | |
45a4a237 SR |
1889 | if (unlikely(ftrace_disabled)) |
1890 | return; | |
1891 | ||
265c831c | 1892 | do_for_each_ftrace_rec(pg, rec) { |
e4f5d544 | 1893 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 1894 | if (failed) { |
3279ba37 SR |
1895 | ftrace_bug(failed, rec->ip); |
1896 | /* Stop processing */ | |
1897 | return; | |
3c1720f0 | 1898 | } |
265c831c | 1899 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
1900 | } |
1901 | ||
c88fd863 SR |
1902 | struct ftrace_rec_iter { |
1903 | struct ftrace_page *pg; | |
1904 | int index; | |
1905 | }; | |
1906 | ||
1907 | /** | |
1908 | * ftrace_rec_iter_start, start up iterating over traced functions | |
1909 | * | |
1910 | * Returns an iterator handle that is used to iterate over all | |
1911 | * the records that represent address locations where functions | |
1912 | * are traced. | |
1913 | * | |
1914 | * May return NULL if no records are available. | |
1915 | */ | |
1916 | struct ftrace_rec_iter *ftrace_rec_iter_start(void) | |
1917 | { | |
1918 | /* | |
1919 | * We only use a single iterator. | |
1920 | * Protected by the ftrace_lock mutex. | |
1921 | */ | |
1922 | static struct ftrace_rec_iter ftrace_rec_iter; | |
1923 | struct ftrace_rec_iter *iter = &ftrace_rec_iter; | |
1924 | ||
1925 | iter->pg = ftrace_pages_start; | |
1926 | iter->index = 0; | |
1927 | ||
1928 | /* Could have empty pages */ | |
1929 | while (iter->pg && !iter->pg->index) | |
1930 | iter->pg = iter->pg->next; | |
1931 | ||
1932 | if (!iter->pg) | |
1933 | return NULL; | |
1934 | ||
1935 | return iter; | |
1936 | } | |
1937 | ||
1938 | /** | |
1939 | * ftrace_rec_iter_next, get the next record to process. | |
1940 | * @iter: The handle to the iterator. | |
1941 | * | |
1942 | * Returns the next iterator after the given iterator @iter. | |
1943 | */ | |
1944 | struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) | |
1945 | { | |
1946 | iter->index++; | |
1947 | ||
1948 | if (iter->index >= iter->pg->index) { | |
1949 | iter->pg = iter->pg->next; | |
1950 | iter->index = 0; | |
1951 | ||
1952 | /* Could have empty pages */ | |
1953 | while (iter->pg && !iter->pg->index) | |
1954 | iter->pg = iter->pg->next; | |
1955 | } | |
1956 | ||
1957 | if (!iter->pg) | |
1958 | return NULL; | |
1959 | ||
1960 | return iter; | |
1961 | } | |
1962 | ||
1963 | /** | |
1964 | * ftrace_rec_iter_record, get the record at the iterator location | |
1965 | * @iter: The current iterator location | |
1966 | * | |
1967 | * Returns the record that the current @iter is at. | |
1968 | */ | |
1969 | struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) | |
1970 | { | |
1971 | return &iter->pg->records[iter->index]; | |
1972 | } | |
1973 | ||
492a7ea5 | 1974 | static int |
31e88909 | 1975 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 SR |
1976 | { |
1977 | unsigned long ip; | |
593eb8a2 | 1978 | int ret; |
3c1720f0 SR |
1979 | |
1980 | ip = rec->ip; | |
1981 | ||
45a4a237 SR |
1982 | if (unlikely(ftrace_disabled)) |
1983 | return 0; | |
1984 | ||
25aac9dc | 1985 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 1986 | if (ret) { |
31e88909 | 1987 | ftrace_bug(ret, ip); |
492a7ea5 | 1988 | return 0; |
37ad5084 | 1989 | } |
492a7ea5 | 1990 | return 1; |
3c1720f0 SR |
1991 | } |
1992 | ||
000ab691 SR |
1993 | /* |
1994 | * archs can override this function if they must do something | |
1995 | * before the modifying code is performed. | |
1996 | */ | |
1997 | int __weak ftrace_arch_code_modify_prepare(void) | |
1998 | { | |
1999 | return 0; | |
2000 | } | |
2001 | ||
2002 | /* | |
2003 | * archs can override this function if they must do something | |
2004 | * after the modifying code is performed. | |
2005 | */ | |
2006 | int __weak ftrace_arch_code_modify_post_process(void) | |
2007 | { | |
2008 | return 0; | |
2009 | } | |
2010 | ||
8ed3e2cf | 2011 | void ftrace_modify_all_code(int command) |
3d083395 | 2012 | { |
59338f75 SRRH |
2013 | int update = command & FTRACE_UPDATE_TRACE_FUNC; |
2014 | ||
2015 | /* | |
2016 | * If the ftrace_caller calls a ftrace_ops func directly, | |
2017 | * we need to make sure that it only traces functions it | |
2018 | * expects to trace. When doing the switch of functions, | |
2019 | * we need to update to the ftrace_ops_list_func first | |
2020 | * before the transition between old and new calls are set, | |
2021 | * as the ftrace_ops_list_func will check the ops hashes | |
2022 | * to make sure the ops are having the right functions | |
2023 | * traced. | |
2024 | */ | |
2025 | if (update) | |
2026 | ftrace_update_ftrace_func(ftrace_ops_list_func); | |
2027 | ||
8ed3e2cf | 2028 | if (command & FTRACE_UPDATE_CALLS) |
d61f82d0 | 2029 | ftrace_replace_code(1); |
8ed3e2cf | 2030 | else if (command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
2031 | ftrace_replace_code(0); |
2032 | ||
405e1d83 SRRH |
2033 | if (update && ftrace_trace_function != ftrace_ops_list_func) { |
2034 | function_trace_op = set_function_trace_op; | |
2035 | smp_wmb(); | |
2036 | /* If irqs are disabled, we are in stop machine */ | |
2037 | if (!irqs_disabled()) | |
2038 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
d61f82d0 | 2039 | ftrace_update_ftrace_func(ftrace_trace_function); |
405e1d83 | 2040 | } |
d61f82d0 | 2041 | |
8ed3e2cf | 2042 | if (command & FTRACE_START_FUNC_RET) |
5a45cfe1 | 2043 | ftrace_enable_ftrace_graph_caller(); |
8ed3e2cf | 2044 | else if (command & FTRACE_STOP_FUNC_RET) |
5a45cfe1 | 2045 | ftrace_disable_ftrace_graph_caller(); |
8ed3e2cf SR |
2046 | } |
2047 | ||
2048 | static int __ftrace_modify_code(void *data) | |
2049 | { | |
2050 | int *command = data; | |
2051 | ||
2052 | ftrace_modify_all_code(*command); | |
5a45cfe1 | 2053 | |
d61f82d0 | 2054 | return 0; |
3d083395 SR |
2055 | } |
2056 | ||
c88fd863 SR |
2057 | /** |
2058 | * ftrace_run_stop_machine, go back to the stop machine method | |
2059 | * @command: The command to tell ftrace what to do | |
2060 | * | |
2061 | * If an arch needs to fall back to the stop machine method, the | |
2062 | * it can call this function. | |
2063 | */ | |
2064 | void ftrace_run_stop_machine(int command) | |
2065 | { | |
2066 | stop_machine(__ftrace_modify_code, &command, NULL); | |
2067 | } | |
2068 | ||
2069 | /** | |
2070 | * arch_ftrace_update_code, modify the code to trace or not trace | |
2071 | * @command: The command that needs to be done | |
2072 | * | |
2073 | * Archs can override this function if it does not need to | |
2074 | * run stop_machine() to modify code. | |
2075 | */ | |
2076 | void __weak arch_ftrace_update_code(int command) | |
2077 | { | |
2078 | ftrace_run_stop_machine(command); | |
2079 | } | |
2080 | ||
e309b41d | 2081 | static void ftrace_run_update_code(int command) |
3d083395 | 2082 | { |
000ab691 SR |
2083 | int ret; |
2084 | ||
2085 | ret = ftrace_arch_code_modify_prepare(); | |
2086 | FTRACE_WARN_ON(ret); | |
2087 | if (ret) | |
2088 | return; | |
c88fd863 SR |
2089 | /* |
2090 | * Do not call function tracer while we update the code. | |
2091 | * We are in stop machine. | |
2092 | */ | |
2093 | function_trace_stop++; | |
000ab691 | 2094 | |
c88fd863 SR |
2095 | /* |
2096 | * By default we use stop_machine() to modify the code. | |
2097 | * But archs can do what ever they want as long as it | |
2098 | * is safe. The stop_machine() is the safest, but also | |
2099 | * produces the most overhead. | |
2100 | */ | |
2101 | arch_ftrace_update_code(command); | |
2102 | ||
c88fd863 | 2103 | function_trace_stop--; |
000ab691 SR |
2104 | |
2105 | ret = ftrace_arch_code_modify_post_process(); | |
2106 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
2107 | } |
2108 | ||
d61f82d0 | 2109 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 2110 | static int ftrace_start_up; |
b848914c | 2111 | static int global_start_up; |
df4fc315 SR |
2112 | |
2113 | static void ftrace_startup_enable(int command) | |
2114 | { | |
2115 | if (saved_ftrace_func != ftrace_trace_function) { | |
2116 | saved_ftrace_func = ftrace_trace_function; | |
2117 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2118 | } | |
2119 | ||
2120 | if (!command || !ftrace_enabled) | |
2121 | return; | |
2122 | ||
2123 | ftrace_run_update_code(command); | |
2124 | } | |
d61f82d0 | 2125 | |
a1cd6173 | 2126 | static int ftrace_startup(struct ftrace_ops *ops, int command) |
3d083395 | 2127 | { |
b848914c | 2128 | bool hash_enable = true; |
8a56d776 | 2129 | int ret; |
b848914c | 2130 | |
4eebcc81 | 2131 | if (unlikely(ftrace_disabled)) |
a1cd6173 | 2132 | return -ENODEV; |
4eebcc81 | 2133 | |
8a56d776 SRRH |
2134 | ret = __register_ftrace_function(ops); |
2135 | if (ret) | |
2136 | return ret; | |
2137 | ||
60a7ecf4 | 2138 | ftrace_start_up++; |
30fb6aa7 | 2139 | command |= FTRACE_UPDATE_CALLS; |
d61f82d0 | 2140 | |
b848914c SR |
2141 | /* ops marked global share the filter hashes */ |
2142 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { | |
2143 | ops = &global_ops; | |
2144 | /* Don't update hash if global is already set */ | |
2145 | if (global_start_up) | |
2146 | hash_enable = false; | |
2147 | global_start_up++; | |
2148 | } | |
2149 | ||
ed926f9b | 2150 | ops->flags |= FTRACE_OPS_FL_ENABLED; |
b848914c | 2151 | if (hash_enable) |
ed926f9b SR |
2152 | ftrace_hash_rec_enable(ops, 1); |
2153 | ||
df4fc315 | 2154 | ftrace_startup_enable(command); |
a1cd6173 SR |
2155 | |
2156 | return 0; | |
3d083395 SR |
2157 | } |
2158 | ||
8a56d776 | 2159 | static int ftrace_shutdown(struct ftrace_ops *ops, int command) |
3d083395 | 2160 | { |
b848914c | 2161 | bool hash_disable = true; |
8a56d776 | 2162 | int ret; |
b848914c | 2163 | |
4eebcc81 | 2164 | if (unlikely(ftrace_disabled)) |
8a56d776 SRRH |
2165 | return -ENODEV; |
2166 | ||
2167 | ret = __unregister_ftrace_function(ops); | |
2168 | if (ret) | |
2169 | return ret; | |
4eebcc81 | 2170 | |
60a7ecf4 | 2171 | ftrace_start_up--; |
9ea1a153 FW |
2172 | /* |
2173 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
2174 | * critical but the ftrace_call callers may be never nopped again after | |
2175 | * further ftrace uses. | |
2176 | */ | |
2177 | WARN_ON_ONCE(ftrace_start_up < 0); | |
2178 | ||
b848914c SR |
2179 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { |
2180 | ops = &global_ops; | |
2181 | global_start_up--; | |
2182 | WARN_ON_ONCE(global_start_up < 0); | |
2183 | /* Don't update hash if global still has users */ | |
2184 | if (global_start_up) { | |
2185 | WARN_ON_ONCE(!ftrace_start_up); | |
2186 | hash_disable = false; | |
2187 | } | |
2188 | } | |
2189 | ||
2190 | if (hash_disable) | |
ed926f9b SR |
2191 | ftrace_hash_rec_disable(ops, 1); |
2192 | ||
b848914c | 2193 | if (ops != &global_ops || !global_start_up) |
ed926f9b | 2194 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
b848914c | 2195 | |
30fb6aa7 | 2196 | command |= FTRACE_UPDATE_CALLS; |
3d083395 | 2197 | |
d61f82d0 SR |
2198 | if (saved_ftrace_func != ftrace_trace_function) { |
2199 | saved_ftrace_func = ftrace_trace_function; | |
2200 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2201 | } | |
3d083395 | 2202 | |
d61f82d0 | 2203 | if (!command || !ftrace_enabled) |
8a56d776 | 2204 | return 0; |
d61f82d0 SR |
2205 | |
2206 | ftrace_run_update_code(command); | |
8a56d776 | 2207 | return 0; |
3d083395 SR |
2208 | } |
2209 | ||
e309b41d | 2210 | static void ftrace_startup_sysctl(void) |
b0fc494f | 2211 | { |
4eebcc81 SR |
2212 | if (unlikely(ftrace_disabled)) |
2213 | return; | |
2214 | ||
d61f82d0 SR |
2215 | /* Force update next time */ |
2216 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
2217 | /* ftrace_start_up is true if we want ftrace running */ |
2218 | if (ftrace_start_up) | |
30fb6aa7 | 2219 | ftrace_run_update_code(FTRACE_UPDATE_CALLS); |
b0fc494f SR |
2220 | } |
2221 | ||
e309b41d | 2222 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 2223 | { |
4eebcc81 SR |
2224 | if (unlikely(ftrace_disabled)) |
2225 | return; | |
2226 | ||
60a7ecf4 SR |
2227 | /* ftrace_start_up is true if ftrace is running */ |
2228 | if (ftrace_start_up) | |
79e406d7 | 2229 | ftrace_run_update_code(FTRACE_DISABLE_CALLS); |
b0fc494f SR |
2230 | } |
2231 | ||
3d083395 SR |
2232 | static cycle_t ftrace_update_time; |
2233 | static unsigned long ftrace_update_cnt; | |
2234 | unsigned long ftrace_update_tot_cnt; | |
2235 | ||
8c4f3c3f | 2236 | static inline int ops_traces_mod(struct ftrace_ops *ops) |
f7bc8b61 | 2237 | { |
8c4f3c3f SRRH |
2238 | /* |
2239 | * Filter_hash being empty will default to trace module. | |
2240 | * But notrace hash requires a test of individual module functions. | |
2241 | */ | |
2242 | return ftrace_hash_empty(ops->filter_hash) && | |
2243 | ftrace_hash_empty(ops->notrace_hash); | |
2244 | } | |
2245 | ||
2246 | /* | |
2247 | * Check if the current ops references the record. | |
2248 | * | |
2249 | * If the ops traces all functions, then it was already accounted for. | |
2250 | * If the ops does not trace the current record function, skip it. | |
2251 | * If the ops ignores the function via notrace filter, skip it. | |
2252 | */ | |
2253 | static inline bool | |
2254 | ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec) | |
2255 | { | |
2256 | /* If ops isn't enabled, ignore it */ | |
2257 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
2258 | return 0; | |
2259 | ||
2260 | /* If ops traces all mods, we already accounted for it */ | |
2261 | if (ops_traces_mod(ops)) | |
2262 | return 0; | |
2263 | ||
2264 | /* The function must be in the filter */ | |
2265 | if (!ftrace_hash_empty(ops->filter_hash) && | |
2266 | !ftrace_lookup_ip(ops->filter_hash, rec->ip)) | |
2267 | return 0; | |
f7bc8b61 | 2268 | |
8c4f3c3f SRRH |
2269 | /* If in notrace hash, we ignore it too */ |
2270 | if (ftrace_lookup_ip(ops->notrace_hash, rec->ip)) | |
2271 | return 0; | |
2272 | ||
2273 | return 1; | |
2274 | } | |
2275 | ||
2276 | static int referenced_filters(struct dyn_ftrace *rec) | |
2277 | { | |
2278 | struct ftrace_ops *ops; | |
2279 | int cnt = 0; | |
2280 | ||
2281 | for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) { | |
2282 | if (ops_references_rec(ops, rec)) | |
2283 | cnt++; | |
2284 | } | |
2285 | ||
2286 | return cnt; | |
f7bc8b61 SR |
2287 | } |
2288 | ||
31e88909 | 2289 | static int ftrace_update_code(struct module *mod) |
3d083395 | 2290 | { |
85ae32ae | 2291 | struct ftrace_page *pg; |
e94142a6 | 2292 | struct dyn_ftrace *p; |
f22f9a89 | 2293 | cycle_t start, stop; |
f7bc8b61 | 2294 | unsigned long ref = 0; |
8c4f3c3f | 2295 | bool test = false; |
85ae32ae | 2296 | int i; |
f7bc8b61 SR |
2297 | |
2298 | /* | |
2299 | * When adding a module, we need to check if tracers are | |
2300 | * currently enabled and if they are set to trace all functions. | |
2301 | * If they are, we need to enable the module functions as well | |
2302 | * as update the reference counts for those function records. | |
2303 | */ | |
2304 | if (mod) { | |
2305 | struct ftrace_ops *ops; | |
2306 | ||
2307 | for (ops = ftrace_ops_list; | |
2308 | ops != &ftrace_list_end; ops = ops->next) { | |
8c4f3c3f SRRH |
2309 | if (ops->flags & FTRACE_OPS_FL_ENABLED) { |
2310 | if (ops_traces_mod(ops)) | |
2311 | ref++; | |
2312 | else | |
2313 | test = true; | |
2314 | } | |
f7bc8b61 SR |
2315 | } |
2316 | } | |
3d083395 | 2317 | |
750ed1a4 | 2318 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
2319 | ftrace_update_cnt = 0; |
2320 | ||
85ae32ae | 2321 | for (pg = ftrace_new_pgs; pg; pg = pg->next) { |
3d083395 | 2322 | |
85ae32ae | 2323 | for (i = 0; i < pg->index; i++) { |
8c4f3c3f SRRH |
2324 | int cnt = ref; |
2325 | ||
85ae32ae SR |
2326 | /* If something went wrong, bail without enabling anything */ |
2327 | if (unlikely(ftrace_disabled)) | |
2328 | return -1; | |
f22f9a89 | 2329 | |
85ae32ae | 2330 | p = &pg->records[i]; |
8c4f3c3f SRRH |
2331 | if (test) |
2332 | cnt += referenced_filters(p); | |
2333 | p->flags = cnt; | |
f22f9a89 | 2334 | |
85ae32ae SR |
2335 | /* |
2336 | * Do the initial record conversion from mcount jump | |
2337 | * to the NOP instructions. | |
2338 | */ | |
2339 | if (!ftrace_code_disable(mod, p)) | |
2340 | break; | |
5cb084bb | 2341 | |
85ae32ae | 2342 | ftrace_update_cnt++; |
5cb084bb | 2343 | |
85ae32ae SR |
2344 | /* |
2345 | * If the tracing is enabled, go ahead and enable the record. | |
2346 | * | |
2347 | * The reason not to enable the record immediatelly is the | |
2348 | * inherent check of ftrace_make_nop/ftrace_make_call for | |
2349 | * correct previous instructions. Making first the NOP | |
2350 | * conversion puts the module to the correct state, thus | |
2351 | * passing the ftrace_make_call check. | |
2352 | */ | |
8c4f3c3f | 2353 | if (ftrace_start_up && cnt) { |
85ae32ae SR |
2354 | int failed = __ftrace_replace_code(p, 1); |
2355 | if (failed) | |
2356 | ftrace_bug(failed, p->ip); | |
2357 | } | |
5cb084bb | 2358 | } |
3d083395 SR |
2359 | } |
2360 | ||
85ae32ae SR |
2361 | ftrace_new_pgs = NULL; |
2362 | ||
750ed1a4 | 2363 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
2364 | ftrace_update_time = stop - start; |
2365 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
2366 | ||
16444a8a ACM |
2367 | return 0; |
2368 | } | |
2369 | ||
a7900875 | 2370 | static int ftrace_allocate_records(struct ftrace_page *pg, int count) |
3c1720f0 | 2371 | { |
a7900875 | 2372 | int order; |
3c1720f0 | 2373 | int cnt; |
3c1720f0 | 2374 | |
a7900875 SR |
2375 | if (WARN_ON(!count)) |
2376 | return -EINVAL; | |
2377 | ||
2378 | order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE)); | |
3c1720f0 SR |
2379 | |
2380 | /* | |
a7900875 SR |
2381 | * We want to fill as much as possible. No more than a page |
2382 | * may be empty. | |
3c1720f0 | 2383 | */ |
a7900875 SR |
2384 | while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE) |
2385 | order--; | |
3c1720f0 | 2386 | |
a7900875 SR |
2387 | again: |
2388 | pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order); | |
3c1720f0 | 2389 | |
a7900875 SR |
2390 | if (!pg->records) { |
2391 | /* if we can't allocate this size, try something smaller */ | |
2392 | if (!order) | |
2393 | return -ENOMEM; | |
2394 | order >>= 1; | |
2395 | goto again; | |
2396 | } | |
3c1720f0 | 2397 | |
a7900875 SR |
2398 | cnt = (PAGE_SIZE << order) / ENTRY_SIZE; |
2399 | pg->size = cnt; | |
3c1720f0 | 2400 | |
a7900875 SR |
2401 | if (cnt > count) |
2402 | cnt = count; | |
2403 | ||
2404 | return cnt; | |
2405 | } | |
2406 | ||
2407 | static struct ftrace_page * | |
2408 | ftrace_allocate_pages(unsigned long num_to_init) | |
2409 | { | |
2410 | struct ftrace_page *start_pg; | |
2411 | struct ftrace_page *pg; | |
2412 | int order; | |
2413 | int cnt; | |
2414 | ||
2415 | if (!num_to_init) | |
2416 | return 0; | |
2417 | ||
2418 | start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL); | |
2419 | if (!pg) | |
2420 | return NULL; | |
2421 | ||
2422 | /* | |
2423 | * Try to allocate as much as possible in one continues | |
2424 | * location that fills in all of the space. We want to | |
2425 | * waste as little space as possible. | |
2426 | */ | |
2427 | for (;;) { | |
2428 | cnt = ftrace_allocate_records(pg, num_to_init); | |
2429 | if (cnt < 0) | |
2430 | goto free_pages; | |
2431 | ||
2432 | num_to_init -= cnt; | |
2433 | if (!num_to_init) | |
3c1720f0 SR |
2434 | break; |
2435 | ||
a7900875 SR |
2436 | pg->next = kzalloc(sizeof(*pg), GFP_KERNEL); |
2437 | if (!pg->next) | |
2438 | goto free_pages; | |
2439 | ||
3c1720f0 SR |
2440 | pg = pg->next; |
2441 | } | |
2442 | ||
a7900875 SR |
2443 | return start_pg; |
2444 | ||
2445 | free_pages: | |
2446 | while (start_pg) { | |
2447 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); | |
2448 | free_pages((unsigned long)pg->records, order); | |
2449 | start_pg = pg->next; | |
2450 | kfree(pg); | |
2451 | pg = start_pg; | |
2452 | } | |
2453 | pr_info("ftrace: FAILED to allocate memory for functions\n"); | |
2454 | return NULL; | |
2455 | } | |
2456 | ||
2457 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) | |
2458 | { | |
2459 | int cnt; | |
2460 | ||
2461 | if (!num_to_init) { | |
2462 | pr_info("ftrace: No functions to be traced?\n"); | |
2463 | return -1; | |
2464 | } | |
2465 | ||
2466 | cnt = num_to_init / ENTRIES_PER_PAGE; | |
2467 | pr_info("ftrace: allocating %ld entries in %d pages\n", | |
2468 | num_to_init, cnt + 1); | |
2469 | ||
3c1720f0 SR |
2470 | return 0; |
2471 | } | |
2472 | ||
5072c59f SR |
2473 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ |
2474 | ||
2475 | struct ftrace_iterator { | |
98c4fd04 | 2476 | loff_t pos; |
4aeb6967 SR |
2477 | loff_t func_pos; |
2478 | struct ftrace_page *pg; | |
2479 | struct dyn_ftrace *func; | |
2480 | struct ftrace_func_probe *probe; | |
2481 | struct trace_parser parser; | |
1cf41dd7 | 2482 | struct ftrace_hash *hash; |
33dc9b12 | 2483 | struct ftrace_ops *ops; |
4aeb6967 SR |
2484 | int hidx; |
2485 | int idx; | |
2486 | unsigned flags; | |
5072c59f SR |
2487 | }; |
2488 | ||
8fc0c701 | 2489 | static void * |
4aeb6967 | 2490 | t_hash_next(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
2491 | { |
2492 | struct ftrace_iterator *iter = m->private; | |
4aeb6967 | 2493 | struct hlist_node *hnd = NULL; |
8fc0c701 SR |
2494 | struct hlist_head *hhd; |
2495 | ||
8fc0c701 | 2496 | (*pos)++; |
98c4fd04 | 2497 | iter->pos = *pos; |
8fc0c701 | 2498 | |
4aeb6967 SR |
2499 | if (iter->probe) |
2500 | hnd = &iter->probe->node; | |
8fc0c701 SR |
2501 | retry: |
2502 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
2503 | return NULL; | |
2504 | ||
2505 | hhd = &ftrace_func_hash[iter->hidx]; | |
2506 | ||
2507 | if (hlist_empty(hhd)) { | |
2508 | iter->hidx++; | |
2509 | hnd = NULL; | |
2510 | goto retry; | |
2511 | } | |
2512 | ||
2513 | if (!hnd) | |
2514 | hnd = hhd->first; | |
2515 | else { | |
2516 | hnd = hnd->next; | |
2517 | if (!hnd) { | |
2518 | iter->hidx++; | |
2519 | goto retry; | |
2520 | } | |
2521 | } | |
2522 | ||
4aeb6967 SR |
2523 | if (WARN_ON_ONCE(!hnd)) |
2524 | return NULL; | |
2525 | ||
2526 | iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node); | |
2527 | ||
2528 | return iter; | |
8fc0c701 SR |
2529 | } |
2530 | ||
2531 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
2532 | { | |
2533 | struct ftrace_iterator *iter = m->private; | |
2534 | void *p = NULL; | |
d82d6244 LZ |
2535 | loff_t l; |
2536 | ||
69a3083c SR |
2537 | if (!(iter->flags & FTRACE_ITER_DO_HASH)) |
2538 | return NULL; | |
2539 | ||
2bccfffd SR |
2540 | if (iter->func_pos > *pos) |
2541 | return NULL; | |
8fc0c701 | 2542 | |
d82d6244 | 2543 | iter->hidx = 0; |
2bccfffd | 2544 | for (l = 0; l <= (*pos - iter->func_pos); ) { |
4aeb6967 | 2545 | p = t_hash_next(m, &l); |
d82d6244 LZ |
2546 | if (!p) |
2547 | break; | |
2548 | } | |
4aeb6967 SR |
2549 | if (!p) |
2550 | return NULL; | |
2551 | ||
98c4fd04 SR |
2552 | /* Only set this if we have an item */ |
2553 | iter->flags |= FTRACE_ITER_HASH; | |
2554 | ||
4aeb6967 | 2555 | return iter; |
8fc0c701 SR |
2556 | } |
2557 | ||
4aeb6967 SR |
2558 | static int |
2559 | t_hash_show(struct seq_file *m, struct ftrace_iterator *iter) | |
8fc0c701 | 2560 | { |
b6887d79 | 2561 | struct ftrace_func_probe *rec; |
8fc0c701 | 2562 | |
4aeb6967 SR |
2563 | rec = iter->probe; |
2564 | if (WARN_ON_ONCE(!rec)) | |
2565 | return -EIO; | |
8fc0c701 | 2566 | |
809dcf29 SR |
2567 | if (rec->ops->print) |
2568 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
2569 | ||
b375a11a | 2570 | seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func); |
8fc0c701 SR |
2571 | |
2572 | if (rec->data) | |
2573 | seq_printf(m, ":%p", rec->data); | |
2574 | seq_putc(m, '\n'); | |
2575 | ||
2576 | return 0; | |
2577 | } | |
2578 | ||
e309b41d | 2579 | static void * |
5072c59f SR |
2580 | t_next(struct seq_file *m, void *v, loff_t *pos) |
2581 | { | |
2582 | struct ftrace_iterator *iter = m->private; | |
fc13cb0c | 2583 | struct ftrace_ops *ops = iter->ops; |
5072c59f SR |
2584 | struct dyn_ftrace *rec = NULL; |
2585 | ||
45a4a237 SR |
2586 | if (unlikely(ftrace_disabled)) |
2587 | return NULL; | |
2588 | ||
8fc0c701 | 2589 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 2590 | return t_hash_next(m, pos); |
8fc0c701 | 2591 | |
5072c59f | 2592 | (*pos)++; |
1106b699 | 2593 | iter->pos = iter->func_pos = *pos; |
5072c59f | 2594 | |
0c75a3ed | 2595 | if (iter->flags & FTRACE_ITER_PRINTALL) |
57c072c7 | 2596 | return t_hash_start(m, pos); |
0c75a3ed | 2597 | |
5072c59f SR |
2598 | retry: |
2599 | if (iter->idx >= iter->pg->index) { | |
2600 | if (iter->pg->next) { | |
2601 | iter->pg = iter->pg->next; | |
2602 | iter->idx = 0; | |
2603 | goto retry; | |
2604 | } | |
2605 | } else { | |
2606 | rec = &iter->pg->records[iter->idx++]; | |
32082309 | 2607 | if (((iter->flags & FTRACE_ITER_FILTER) && |
f45948e8 | 2608 | !(ftrace_lookup_ip(ops->filter_hash, rec->ip))) || |
0183fb1c | 2609 | |
41c52c0d | 2610 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
647bcd03 SR |
2611 | !ftrace_lookup_ip(ops->notrace_hash, rec->ip)) || |
2612 | ||
2613 | ((iter->flags & FTRACE_ITER_ENABLED) && | |
23ea9c4d | 2614 | !(rec->flags & FTRACE_FL_ENABLED))) { |
647bcd03 | 2615 | |
5072c59f SR |
2616 | rec = NULL; |
2617 | goto retry; | |
2618 | } | |
2619 | } | |
2620 | ||
4aeb6967 | 2621 | if (!rec) |
57c072c7 | 2622 | return t_hash_start(m, pos); |
4aeb6967 SR |
2623 | |
2624 | iter->func = rec; | |
2625 | ||
2626 | return iter; | |
5072c59f SR |
2627 | } |
2628 | ||
98c4fd04 SR |
2629 | static void reset_iter_read(struct ftrace_iterator *iter) |
2630 | { | |
2631 | iter->pos = 0; | |
2632 | iter->func_pos = 0; | |
70f77b3f | 2633 | iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_HASH); |
5072c59f SR |
2634 | } |
2635 | ||
2636 | static void *t_start(struct seq_file *m, loff_t *pos) | |
2637 | { | |
2638 | struct ftrace_iterator *iter = m->private; | |
fc13cb0c | 2639 | struct ftrace_ops *ops = iter->ops; |
5072c59f | 2640 | void *p = NULL; |
694ce0a5 | 2641 | loff_t l; |
5072c59f | 2642 | |
8fc0c701 | 2643 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
2644 | |
2645 | if (unlikely(ftrace_disabled)) | |
2646 | return NULL; | |
2647 | ||
98c4fd04 SR |
2648 | /* |
2649 | * If an lseek was done, then reset and start from beginning. | |
2650 | */ | |
2651 | if (*pos < iter->pos) | |
2652 | reset_iter_read(iter); | |
2653 | ||
0c75a3ed SR |
2654 | /* |
2655 | * For set_ftrace_filter reading, if we have the filter | |
2656 | * off, we can short cut and just print out that all | |
2657 | * functions are enabled. | |
2658 | */ | |
06a51d93 SR |
2659 | if (iter->flags & FTRACE_ITER_FILTER && |
2660 | ftrace_hash_empty(ops->filter_hash)) { | |
0c75a3ed | 2661 | if (*pos > 0) |
8fc0c701 | 2662 | return t_hash_start(m, pos); |
0c75a3ed | 2663 | iter->flags |= FTRACE_ITER_PRINTALL; |
df091625 CW |
2664 | /* reset in case of seek/pread */ |
2665 | iter->flags &= ~FTRACE_ITER_HASH; | |
0c75a3ed SR |
2666 | return iter; |
2667 | } | |
2668 | ||
8fc0c701 SR |
2669 | if (iter->flags & FTRACE_ITER_HASH) |
2670 | return t_hash_start(m, pos); | |
2671 | ||
98c4fd04 SR |
2672 | /* |
2673 | * Unfortunately, we need to restart at ftrace_pages_start | |
2674 | * every time we let go of the ftrace_mutex. This is because | |
2675 | * those pointers can change without the lock. | |
2676 | */ | |
694ce0a5 LZ |
2677 | iter->pg = ftrace_pages_start; |
2678 | iter->idx = 0; | |
2679 | for (l = 0; l <= *pos; ) { | |
2680 | p = t_next(m, p, &l); | |
2681 | if (!p) | |
2682 | break; | |
50cdaf08 | 2683 | } |
5821e1b7 | 2684 | |
69a3083c SR |
2685 | if (!p) |
2686 | return t_hash_start(m, pos); | |
4aeb6967 SR |
2687 | |
2688 | return iter; | |
5072c59f SR |
2689 | } |
2690 | ||
2691 | static void t_stop(struct seq_file *m, void *p) | |
2692 | { | |
8fc0c701 | 2693 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
2694 | } |
2695 | ||
2696 | static int t_show(struct seq_file *m, void *v) | |
2697 | { | |
0c75a3ed | 2698 | struct ftrace_iterator *iter = m->private; |
4aeb6967 | 2699 | struct dyn_ftrace *rec; |
5072c59f | 2700 | |
8fc0c701 | 2701 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 2702 | return t_hash_show(m, iter); |
8fc0c701 | 2703 | |
0c75a3ed SR |
2704 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
2705 | seq_printf(m, "#### all functions enabled ####\n"); | |
2706 | return 0; | |
2707 | } | |
2708 | ||
4aeb6967 SR |
2709 | rec = iter->func; |
2710 | ||
5072c59f SR |
2711 | if (!rec) |
2712 | return 0; | |
2713 | ||
647bcd03 SR |
2714 | seq_printf(m, "%ps", (void *)rec->ip); |
2715 | if (iter->flags & FTRACE_ITER_ENABLED) | |
08f6fba5 SR |
2716 | seq_printf(m, " (%ld)%s", |
2717 | rec->flags & ~FTRACE_FL_MASK, | |
2718 | rec->flags & FTRACE_FL_REGS ? " R" : ""); | |
647bcd03 | 2719 | seq_printf(m, "\n"); |
5072c59f SR |
2720 | |
2721 | return 0; | |
2722 | } | |
2723 | ||
88e9d34c | 2724 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
2725 | .start = t_start, |
2726 | .next = t_next, | |
2727 | .stop = t_stop, | |
2728 | .show = t_show, | |
2729 | }; | |
2730 | ||
e309b41d | 2731 | static int |
5072c59f SR |
2732 | ftrace_avail_open(struct inode *inode, struct file *file) |
2733 | { | |
2734 | struct ftrace_iterator *iter; | |
5072c59f | 2735 | |
4eebcc81 SR |
2736 | if (unlikely(ftrace_disabled)) |
2737 | return -ENODEV; | |
2738 | ||
50e18b94 JO |
2739 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
2740 | if (iter) { | |
2741 | iter->pg = ftrace_pages_start; | |
2742 | iter->ops = &global_ops; | |
4bf39a94 | 2743 | } |
5072c59f | 2744 | |
50e18b94 | 2745 | return iter ? 0 : -ENOMEM; |
5072c59f SR |
2746 | } |
2747 | ||
647bcd03 SR |
2748 | static int |
2749 | ftrace_enabled_open(struct inode *inode, struct file *file) | |
2750 | { | |
2751 | struct ftrace_iterator *iter; | |
647bcd03 SR |
2752 | |
2753 | if (unlikely(ftrace_disabled)) | |
2754 | return -ENODEV; | |
2755 | ||
50e18b94 JO |
2756 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
2757 | if (iter) { | |
2758 | iter->pg = ftrace_pages_start; | |
2759 | iter->flags = FTRACE_ITER_ENABLED; | |
2760 | iter->ops = &global_ops; | |
647bcd03 SR |
2761 | } |
2762 | ||
50e18b94 | 2763 | return iter ? 0 : -ENOMEM; |
647bcd03 SR |
2764 | } |
2765 | ||
1cf41dd7 | 2766 | static void ftrace_filter_reset(struct ftrace_hash *hash) |
5072c59f | 2767 | { |
52baf119 | 2768 | mutex_lock(&ftrace_lock); |
1cf41dd7 | 2769 | ftrace_hash_clear(hash); |
52baf119 | 2770 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
2771 | } |
2772 | ||
fc13cb0c SR |
2773 | /** |
2774 | * ftrace_regex_open - initialize function tracer filter files | |
2775 | * @ops: The ftrace_ops that hold the hash filters | |
2776 | * @flag: The type of filter to process | |
2777 | * @inode: The inode, usually passed in to your open routine | |
2778 | * @file: The file, usually passed in to your open routine | |
2779 | * | |
2780 | * ftrace_regex_open() initializes the filter files for the | |
2781 | * @ops. Depending on @flag it may process the filter hash or | |
2782 | * the notrace hash of @ops. With this called from the open | |
2783 | * routine, you can use ftrace_filter_write() for the write | |
2784 | * routine if @flag has FTRACE_ITER_FILTER set, or | |
2785 | * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set. | |
098c879e | 2786 | * tracing_lseek() should be used as the lseek routine, and |
fc13cb0c SR |
2787 | * release must call ftrace_regex_release(). |
2788 | */ | |
2789 | int | |
f45948e8 | 2790 | ftrace_regex_open(struct ftrace_ops *ops, int flag, |
1cf41dd7 | 2791 | struct inode *inode, struct file *file) |
5072c59f SR |
2792 | { |
2793 | struct ftrace_iterator *iter; | |
f45948e8 | 2794 | struct ftrace_hash *hash; |
5072c59f SR |
2795 | int ret = 0; |
2796 | ||
f04f24fb MH |
2797 | ftrace_ops_init(ops); |
2798 | ||
4eebcc81 SR |
2799 | if (unlikely(ftrace_disabled)) |
2800 | return -ENODEV; | |
2801 | ||
5072c59f SR |
2802 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
2803 | if (!iter) | |
2804 | return -ENOMEM; | |
2805 | ||
689fd8b6 | 2806 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) { |
2807 | kfree(iter); | |
2808 | return -ENOMEM; | |
2809 | } | |
2810 | ||
3f2367ba MH |
2811 | iter->ops = ops; |
2812 | iter->flags = flag; | |
2813 | ||
2814 | mutex_lock(&ops->regex_lock); | |
2815 | ||
f45948e8 SR |
2816 | if (flag & FTRACE_ITER_NOTRACE) |
2817 | hash = ops->notrace_hash; | |
2818 | else | |
2819 | hash = ops->filter_hash; | |
2820 | ||
33dc9b12 | 2821 | if (file->f_mode & FMODE_WRITE) { |
33dc9b12 | 2822 | iter->hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash); |
33dc9b12 SR |
2823 | if (!iter->hash) { |
2824 | trace_parser_put(&iter->parser); | |
2825 | kfree(iter); | |
3f2367ba MH |
2826 | ret = -ENOMEM; |
2827 | goto out_unlock; | |
33dc9b12 SR |
2828 | } |
2829 | } | |
1cf41dd7 | 2830 | |
5072c59f | 2831 | if ((file->f_mode & FMODE_WRITE) && |
8650ae32 | 2832 | (file->f_flags & O_TRUNC)) |
33dc9b12 | 2833 | ftrace_filter_reset(iter->hash); |
5072c59f SR |
2834 | |
2835 | if (file->f_mode & FMODE_READ) { | |
2836 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
2837 | |
2838 | ret = seq_open(file, &show_ftrace_seq_ops); | |
2839 | if (!ret) { | |
2840 | struct seq_file *m = file->private_data; | |
2841 | m->private = iter; | |
79fe249c | 2842 | } else { |
33dc9b12 SR |
2843 | /* Failed */ |
2844 | free_ftrace_hash(iter->hash); | |
79fe249c | 2845 | trace_parser_put(&iter->parser); |
5072c59f | 2846 | kfree(iter); |
79fe249c | 2847 | } |
5072c59f SR |
2848 | } else |
2849 | file->private_data = iter; | |
3f2367ba MH |
2850 | |
2851 | out_unlock: | |
f04f24fb | 2852 | mutex_unlock(&ops->regex_lock); |
5072c59f SR |
2853 | |
2854 | return ret; | |
2855 | } | |
2856 | ||
41c52c0d SR |
2857 | static int |
2858 | ftrace_filter_open(struct inode *inode, struct file *file) | |
2859 | { | |
69a3083c SR |
2860 | return ftrace_regex_open(&global_ops, |
2861 | FTRACE_ITER_FILTER | FTRACE_ITER_DO_HASH, | |
2862 | inode, file); | |
41c52c0d SR |
2863 | } |
2864 | ||
2865 | static int | |
2866 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
2867 | { | |
f45948e8 | 2868 | return ftrace_regex_open(&global_ops, FTRACE_ITER_NOTRACE, |
1cf41dd7 | 2869 | inode, file); |
41c52c0d SR |
2870 | } |
2871 | ||
64e7c440 | 2872 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 2873 | { |
9f4801e3 | 2874 | int matched = 0; |
751e9983 | 2875 | int slen; |
9f4801e3 | 2876 | |
9f4801e3 SR |
2877 | switch (type) { |
2878 | case MATCH_FULL: | |
2879 | if (strcmp(str, regex) == 0) | |
2880 | matched = 1; | |
2881 | break; | |
2882 | case MATCH_FRONT_ONLY: | |
2883 | if (strncmp(str, regex, len) == 0) | |
2884 | matched = 1; | |
2885 | break; | |
2886 | case MATCH_MIDDLE_ONLY: | |
2887 | if (strstr(str, regex)) | |
2888 | matched = 1; | |
2889 | break; | |
2890 | case MATCH_END_ONLY: | |
751e9983 LZ |
2891 | slen = strlen(str); |
2892 | if (slen >= len && memcmp(str + slen - len, regex, len) == 0) | |
9f4801e3 SR |
2893 | matched = 1; |
2894 | break; | |
2895 | } | |
2896 | ||
2897 | return matched; | |
2898 | } | |
2899 | ||
b448c4e3 | 2900 | static int |
1cf41dd7 | 2901 | enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not) |
996e87be | 2902 | { |
b448c4e3 | 2903 | struct ftrace_func_entry *entry; |
b448c4e3 SR |
2904 | int ret = 0; |
2905 | ||
1cf41dd7 SR |
2906 | entry = ftrace_lookup_ip(hash, rec->ip); |
2907 | if (not) { | |
2908 | /* Do nothing if it doesn't exist */ | |
2909 | if (!entry) | |
2910 | return 0; | |
b448c4e3 | 2911 | |
33dc9b12 | 2912 | free_hash_entry(hash, entry); |
1cf41dd7 SR |
2913 | } else { |
2914 | /* Do nothing if it exists */ | |
2915 | if (entry) | |
2916 | return 0; | |
b448c4e3 | 2917 | |
1cf41dd7 | 2918 | ret = add_hash_entry(hash, rec->ip); |
b448c4e3 SR |
2919 | } |
2920 | return ret; | |
996e87be SR |
2921 | } |
2922 | ||
64e7c440 | 2923 | static int |
b9df92d2 SR |
2924 | ftrace_match_record(struct dyn_ftrace *rec, char *mod, |
2925 | char *regex, int len, int type) | |
64e7c440 SR |
2926 | { |
2927 | char str[KSYM_SYMBOL_LEN]; | |
b9df92d2 SR |
2928 | char *modname; |
2929 | ||
2930 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
2931 | ||
2932 | if (mod) { | |
2933 | /* module lookup requires matching the module */ | |
2934 | if (!modname || strcmp(modname, mod)) | |
2935 | return 0; | |
2936 | ||
2937 | /* blank search means to match all funcs in the mod */ | |
2938 | if (!len) | |
2939 | return 1; | |
2940 | } | |
64e7c440 | 2941 | |
64e7c440 SR |
2942 | return ftrace_match(str, regex, len, type); |
2943 | } | |
2944 | ||
1cf41dd7 SR |
2945 | static int |
2946 | match_records(struct ftrace_hash *hash, char *buff, | |
2947 | int len, char *mod, int not) | |
9f4801e3 | 2948 | { |
b9df92d2 | 2949 | unsigned search_len = 0; |
9f4801e3 SR |
2950 | struct ftrace_page *pg; |
2951 | struct dyn_ftrace *rec; | |
b9df92d2 SR |
2952 | int type = MATCH_FULL; |
2953 | char *search = buff; | |
311d16da | 2954 | int found = 0; |
b448c4e3 | 2955 | int ret; |
9f4801e3 | 2956 | |
b9df92d2 SR |
2957 | if (len) { |
2958 | type = filter_parse_regex(buff, len, &search, ¬); | |
2959 | search_len = strlen(search); | |
2960 | } | |
9f4801e3 | 2961 | |
52baf119 | 2962 | mutex_lock(&ftrace_lock); |
265c831c | 2963 | |
b9df92d2 SR |
2964 | if (unlikely(ftrace_disabled)) |
2965 | goto out_unlock; | |
9f4801e3 | 2966 | |
265c831c | 2967 | do_for_each_ftrace_rec(pg, rec) { |
b9df92d2 | 2968 | if (ftrace_match_record(rec, mod, search, search_len, type)) { |
1cf41dd7 | 2969 | ret = enter_record(hash, rec, not); |
b448c4e3 SR |
2970 | if (ret < 0) { |
2971 | found = ret; | |
2972 | goto out_unlock; | |
2973 | } | |
311d16da | 2974 | found = 1; |
265c831c SR |
2975 | } |
2976 | } while_for_each_ftrace_rec(); | |
b9df92d2 | 2977 | out_unlock: |
52baf119 | 2978 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
2979 | |
2980 | return found; | |
5072c59f SR |
2981 | } |
2982 | ||
64e7c440 | 2983 | static int |
1cf41dd7 | 2984 | ftrace_match_records(struct ftrace_hash *hash, char *buff, int len) |
64e7c440 | 2985 | { |
1cf41dd7 | 2986 | return match_records(hash, buff, len, NULL, 0); |
64e7c440 SR |
2987 | } |
2988 | ||
1cf41dd7 SR |
2989 | static int |
2990 | ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod) | |
64e7c440 | 2991 | { |
64e7c440 | 2992 | int not = 0; |
6a24a244 | 2993 | |
64e7c440 SR |
2994 | /* blank or '*' mean the same */ |
2995 | if (strcmp(buff, "*") == 0) | |
2996 | buff[0] = 0; | |
2997 | ||
2998 | /* handle the case of 'dont filter this module' */ | |
2999 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
3000 | buff[0] = 0; | |
3001 | not = 1; | |
3002 | } | |
3003 | ||
1cf41dd7 | 3004 | return match_records(hash, buff, strlen(buff), mod, not); |
64e7c440 SR |
3005 | } |
3006 | ||
f6180773 SR |
3007 | /* |
3008 | * We register the module command as a template to show others how | |
3009 | * to register the a command as well. | |
3010 | */ | |
3011 | ||
3012 | static int | |
43dd61c9 SR |
3013 | ftrace_mod_callback(struct ftrace_hash *hash, |
3014 | char *func, char *cmd, char *param, int enable) | |
f6180773 SR |
3015 | { |
3016 | char *mod; | |
b448c4e3 | 3017 | int ret = -EINVAL; |
f6180773 SR |
3018 | |
3019 | /* | |
3020 | * cmd == 'mod' because we only registered this func | |
3021 | * for the 'mod' ftrace_func_command. | |
3022 | * But if you register one func with multiple commands, | |
3023 | * you can tell which command was used by the cmd | |
3024 | * parameter. | |
3025 | */ | |
3026 | ||
3027 | /* we must have a module name */ | |
3028 | if (!param) | |
b448c4e3 | 3029 | return ret; |
f6180773 SR |
3030 | |
3031 | mod = strsep(¶m, ":"); | |
3032 | if (!strlen(mod)) | |
b448c4e3 | 3033 | return ret; |
f6180773 | 3034 | |
1cf41dd7 | 3035 | ret = ftrace_match_module_records(hash, func, mod); |
b448c4e3 SR |
3036 | if (!ret) |
3037 | ret = -EINVAL; | |
3038 | if (ret < 0) | |
3039 | return ret; | |
3040 | ||
3041 | return 0; | |
f6180773 SR |
3042 | } |
3043 | ||
3044 | static struct ftrace_func_command ftrace_mod_cmd = { | |
3045 | .name = "mod", | |
3046 | .func = ftrace_mod_callback, | |
3047 | }; | |
3048 | ||
3049 | static int __init ftrace_mod_cmd_init(void) | |
3050 | { | |
3051 | return register_ftrace_command(&ftrace_mod_cmd); | |
3052 | } | |
6f415672 | 3053 | core_initcall(ftrace_mod_cmd_init); |
f6180773 | 3054 | |
2f5f6ad9 | 3055 | static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 3056 | struct ftrace_ops *op, struct pt_regs *pt_regs) |
59df055f | 3057 | { |
b6887d79 | 3058 | struct ftrace_func_probe *entry; |
59df055f | 3059 | struct hlist_head *hhd; |
59df055f | 3060 | unsigned long key; |
59df055f SR |
3061 | |
3062 | key = hash_long(ip, FTRACE_HASH_BITS); | |
3063 | ||
3064 | hhd = &ftrace_func_hash[key]; | |
3065 | ||
3066 | if (hlist_empty(hhd)) | |
3067 | return; | |
3068 | ||
3069 | /* | |
3070 | * Disable preemption for these calls to prevent a RCU grace | |
3071 | * period. This syncs the hash iteration and freeing of items | |
3072 | * on the hash. rcu_read_lock is too dangerous here. | |
3073 | */ | |
5168ae50 | 3074 | preempt_disable_notrace(); |
1bb539ca | 3075 | hlist_for_each_entry_rcu_notrace(entry, hhd, node) { |
59df055f SR |
3076 | if (entry->ip == ip) |
3077 | entry->ops->func(ip, parent_ip, &entry->data); | |
3078 | } | |
5168ae50 | 3079 | preempt_enable_notrace(); |
59df055f SR |
3080 | } |
3081 | ||
b6887d79 | 3082 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 3083 | { |
fb9fb015 | 3084 | .func = function_trace_probe_call, |
f04f24fb MH |
3085 | .flags = FTRACE_OPS_FL_INITIALIZED, |
3086 | INIT_REGEX_LOCK(trace_probe_ops) | |
59df055f SR |
3087 | }; |
3088 | ||
b6887d79 | 3089 | static int ftrace_probe_registered; |
59df055f | 3090 | |
b6887d79 | 3091 | static void __enable_ftrace_function_probe(void) |
59df055f | 3092 | { |
b848914c | 3093 | int ret; |
59df055f SR |
3094 | int i; |
3095 | ||
19dd603e SRRH |
3096 | if (ftrace_probe_registered) { |
3097 | /* still need to update the function call sites */ | |
3098 | if (ftrace_enabled) | |
3099 | ftrace_run_update_code(FTRACE_UPDATE_CALLS); | |
59df055f | 3100 | return; |
19dd603e | 3101 | } |
59df055f SR |
3102 | |
3103 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
3104 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
3105 | if (hhd->first) | |
3106 | break; | |
3107 | } | |
3108 | /* Nothing registered? */ | |
3109 | if (i == FTRACE_FUNC_HASHSIZE) | |
3110 | return; | |
3111 | ||
8a56d776 | 3112 | ret = ftrace_startup(&trace_probe_ops, 0); |
b848914c | 3113 | |
b6887d79 | 3114 | ftrace_probe_registered = 1; |
59df055f SR |
3115 | } |
3116 | ||
b6887d79 | 3117 | static void __disable_ftrace_function_probe(void) |
59df055f SR |
3118 | { |
3119 | int i; | |
3120 | ||
b6887d79 | 3121 | if (!ftrace_probe_registered) |
59df055f SR |
3122 | return; |
3123 | ||
3124 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
3125 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
3126 | if (hhd->first) | |
3127 | return; | |
3128 | } | |
3129 | ||
3130 | /* no more funcs left */ | |
8a56d776 | 3131 | ftrace_shutdown(&trace_probe_ops, 0); |
b848914c | 3132 | |
b6887d79 | 3133 | ftrace_probe_registered = 0; |
59df055f SR |
3134 | } |
3135 | ||
3136 | ||
7818b388 | 3137 | static void ftrace_free_entry(struct ftrace_func_probe *entry) |
59df055f | 3138 | { |
59df055f | 3139 | if (entry->ops->free) |
e67efb93 | 3140 | entry->ops->free(entry->ops, entry->ip, &entry->data); |
59df055f SR |
3141 | kfree(entry); |
3142 | } | |
3143 | ||
59df055f | 3144 | int |
b6887d79 | 3145 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3146 | void *data) |
3147 | { | |
b6887d79 | 3148 | struct ftrace_func_probe *entry; |
e1df4cb6 SRRH |
3149 | struct ftrace_hash **orig_hash = &trace_probe_ops.filter_hash; |
3150 | struct ftrace_hash *hash; | |
59df055f SR |
3151 | struct ftrace_page *pg; |
3152 | struct dyn_ftrace *rec; | |
59df055f | 3153 | int type, len, not; |
6a24a244 | 3154 | unsigned long key; |
59df055f SR |
3155 | int count = 0; |
3156 | char *search; | |
e1df4cb6 | 3157 | int ret; |
59df055f | 3158 | |
3f6fe06d | 3159 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
3160 | len = strlen(search); |
3161 | ||
b6887d79 | 3162 | /* we do not support '!' for function probes */ |
59df055f SR |
3163 | if (WARN_ON(not)) |
3164 | return -EINVAL; | |
3165 | ||
3f2367ba | 3166 | mutex_lock(&trace_probe_ops.regex_lock); |
59df055f | 3167 | |
e1df4cb6 SRRH |
3168 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); |
3169 | if (!hash) { | |
3170 | count = -ENOMEM; | |
5ae0bf59 | 3171 | goto out; |
e1df4cb6 SRRH |
3172 | } |
3173 | ||
3174 | if (unlikely(ftrace_disabled)) { | |
3175 | count = -ENODEV; | |
5ae0bf59 | 3176 | goto out; |
e1df4cb6 | 3177 | } |
59df055f | 3178 | |
5ae0bf59 SRRH |
3179 | mutex_lock(&ftrace_lock); |
3180 | ||
45a4a237 | 3181 | do_for_each_ftrace_rec(pg, rec) { |
59df055f | 3182 | |
b9df92d2 | 3183 | if (!ftrace_match_record(rec, NULL, search, len, type)) |
59df055f SR |
3184 | continue; |
3185 | ||
3186 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
3187 | if (!entry) { | |
b6887d79 | 3188 | /* If we did not process any, then return error */ |
59df055f SR |
3189 | if (!count) |
3190 | count = -ENOMEM; | |
3191 | goto out_unlock; | |
3192 | } | |
3193 | ||
3194 | count++; | |
3195 | ||
3196 | entry->data = data; | |
3197 | ||
3198 | /* | |
3199 | * The caller might want to do something special | |
3200 | * for each function we find. We call the callback | |
3201 | * to give the caller an opportunity to do so. | |
3202 | */ | |
e67efb93 SRRH |
3203 | if (ops->init) { |
3204 | if (ops->init(ops, rec->ip, &entry->data) < 0) { | |
59df055f SR |
3205 | /* caller does not like this func */ |
3206 | kfree(entry); | |
3207 | continue; | |
3208 | } | |
3209 | } | |
3210 | ||
e1df4cb6 SRRH |
3211 | ret = enter_record(hash, rec, 0); |
3212 | if (ret < 0) { | |
3213 | kfree(entry); | |
3214 | count = ret; | |
3215 | goto out_unlock; | |
3216 | } | |
3217 | ||
59df055f SR |
3218 | entry->ops = ops; |
3219 | entry->ip = rec->ip; | |
3220 | ||
3221 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
3222 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
3223 | ||
3224 | } while_for_each_ftrace_rec(); | |
e1df4cb6 SRRH |
3225 | |
3226 | ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash); | |
3227 | if (ret < 0) | |
3228 | count = ret; | |
3229 | ||
b6887d79 | 3230 | __enable_ftrace_function_probe(); |
59df055f SR |
3231 | |
3232 | out_unlock: | |
5ae0bf59 SRRH |
3233 | mutex_unlock(&ftrace_lock); |
3234 | out: | |
3f2367ba | 3235 | mutex_unlock(&trace_probe_ops.regex_lock); |
e1df4cb6 | 3236 | free_ftrace_hash(hash); |
59df055f SR |
3237 | |
3238 | return count; | |
3239 | } | |
3240 | ||
3241 | enum { | |
b6887d79 SR |
3242 | PROBE_TEST_FUNC = 1, |
3243 | PROBE_TEST_DATA = 2 | |
59df055f SR |
3244 | }; |
3245 | ||
3246 | static void | |
b6887d79 | 3247 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3248 | void *data, int flags) |
3249 | { | |
e1df4cb6 | 3250 | struct ftrace_func_entry *rec_entry; |
b6887d79 | 3251 | struct ftrace_func_probe *entry; |
7818b388 | 3252 | struct ftrace_func_probe *p; |
e1df4cb6 | 3253 | struct ftrace_hash **orig_hash = &trace_probe_ops.filter_hash; |
7818b388 | 3254 | struct list_head free_list; |
e1df4cb6 | 3255 | struct ftrace_hash *hash; |
b67bfe0d | 3256 | struct hlist_node *tmp; |
59df055f SR |
3257 | char str[KSYM_SYMBOL_LEN]; |
3258 | int type = MATCH_FULL; | |
3259 | int i, len = 0; | |
3260 | char *search; | |
3261 | ||
b36461da | 3262 | if (glob && (strcmp(glob, "*") == 0 || !strlen(glob))) |
59df055f | 3263 | glob = NULL; |
b36461da | 3264 | else if (glob) { |
59df055f SR |
3265 | int not; |
3266 | ||
3f6fe06d | 3267 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
3268 | len = strlen(search); |
3269 | ||
b6887d79 | 3270 | /* we do not support '!' for function probes */ |
59df055f SR |
3271 | if (WARN_ON(not)) |
3272 | return; | |
3273 | } | |
3274 | ||
3f2367ba | 3275 | mutex_lock(&trace_probe_ops.regex_lock); |
e1df4cb6 SRRH |
3276 | |
3277 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
3278 | if (!hash) | |
3279 | /* Hmm, should report this somehow */ | |
3280 | goto out_unlock; | |
3281 | ||
7818b388 SRRH |
3282 | INIT_LIST_HEAD(&free_list); |
3283 | ||
59df055f SR |
3284 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { |
3285 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
3286 | ||
b67bfe0d | 3287 | hlist_for_each_entry_safe(entry, tmp, hhd, node) { |
59df055f SR |
3288 | |
3289 | /* break up if statements for readability */ | |
b6887d79 | 3290 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
3291 | continue; |
3292 | ||
b6887d79 | 3293 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
3294 | continue; |
3295 | ||
3296 | /* do this last, since it is the most expensive */ | |
3297 | if (glob) { | |
3298 | kallsyms_lookup(entry->ip, NULL, NULL, | |
3299 | NULL, str); | |
3300 | if (!ftrace_match(str, glob, len, type)) | |
3301 | continue; | |
3302 | } | |
3303 | ||
e1df4cb6 SRRH |
3304 | rec_entry = ftrace_lookup_ip(hash, entry->ip); |
3305 | /* It is possible more than one entry had this ip */ | |
3306 | if (rec_entry) | |
3307 | free_hash_entry(hash, rec_entry); | |
3308 | ||
740466bc | 3309 | hlist_del_rcu(&entry->node); |
7818b388 | 3310 | list_add(&entry->free_list, &free_list); |
59df055f SR |
3311 | } |
3312 | } | |
3f2367ba | 3313 | mutex_lock(&ftrace_lock); |
b6887d79 | 3314 | __disable_ftrace_function_probe(); |
e1df4cb6 SRRH |
3315 | /* |
3316 | * Remove after the disable is called. Otherwise, if the last | |
3317 | * probe is removed, a null hash means *all enabled*. | |
3318 | */ | |
3319 | ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash); | |
7818b388 SRRH |
3320 | synchronize_sched(); |
3321 | list_for_each_entry_safe(entry, p, &free_list, free_list) { | |
3322 | list_del(&entry->free_list); | |
3323 | ftrace_free_entry(entry); | |
3324 | } | |
3f2367ba | 3325 | mutex_unlock(&ftrace_lock); |
7818b388 | 3326 | |
e1df4cb6 | 3327 | out_unlock: |
3f2367ba | 3328 | mutex_unlock(&trace_probe_ops.regex_lock); |
e1df4cb6 | 3329 | free_ftrace_hash(hash); |
59df055f SR |
3330 | } |
3331 | ||
3332 | void | |
b6887d79 | 3333 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3334 | void *data) |
3335 | { | |
b6887d79 SR |
3336 | __unregister_ftrace_function_probe(glob, ops, data, |
3337 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
3338 | } |
3339 | ||
3340 | void | |
b6887d79 | 3341 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 3342 | { |
b6887d79 | 3343 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
3344 | } |
3345 | ||
b6887d79 | 3346 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 3347 | { |
b6887d79 | 3348 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
3349 | } |
3350 | ||
f6180773 SR |
3351 | static LIST_HEAD(ftrace_commands); |
3352 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
3353 | ||
38de93ab TZ |
3354 | /* |
3355 | * Currently we only register ftrace commands from __init, so mark this | |
3356 | * __init too. | |
3357 | */ | |
3358 | __init int register_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
3359 | { |
3360 | struct ftrace_func_command *p; | |
3361 | int ret = 0; | |
3362 | ||
3363 | mutex_lock(&ftrace_cmd_mutex); | |
3364 | list_for_each_entry(p, &ftrace_commands, list) { | |
3365 | if (strcmp(cmd->name, p->name) == 0) { | |
3366 | ret = -EBUSY; | |
3367 | goto out_unlock; | |
3368 | } | |
3369 | } | |
3370 | list_add(&cmd->list, &ftrace_commands); | |
3371 | out_unlock: | |
3372 | mutex_unlock(&ftrace_cmd_mutex); | |
3373 | ||
3374 | return ret; | |
3375 | } | |
3376 | ||
38de93ab TZ |
3377 | /* |
3378 | * Currently we only unregister ftrace commands from __init, so mark | |
3379 | * this __init too. | |
3380 | */ | |
3381 | __init int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
3382 | { |
3383 | struct ftrace_func_command *p, *n; | |
3384 | int ret = -ENODEV; | |
3385 | ||
3386 | mutex_lock(&ftrace_cmd_mutex); | |
3387 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
3388 | if (strcmp(cmd->name, p->name) == 0) { | |
3389 | ret = 0; | |
3390 | list_del_init(&p->list); | |
3391 | goto out_unlock; | |
3392 | } | |
3393 | } | |
3394 | out_unlock: | |
3395 | mutex_unlock(&ftrace_cmd_mutex); | |
3396 | ||
3397 | return ret; | |
3398 | } | |
3399 | ||
33dc9b12 SR |
3400 | static int ftrace_process_regex(struct ftrace_hash *hash, |
3401 | char *buff, int len, int enable) | |
64e7c440 | 3402 | { |
f6180773 | 3403 | char *func, *command, *next = buff; |
6a24a244 | 3404 | struct ftrace_func_command *p; |
0aff1c0c | 3405 | int ret = -EINVAL; |
64e7c440 SR |
3406 | |
3407 | func = strsep(&next, ":"); | |
3408 | ||
3409 | if (!next) { | |
1cf41dd7 | 3410 | ret = ftrace_match_records(hash, func, len); |
b448c4e3 SR |
3411 | if (!ret) |
3412 | ret = -EINVAL; | |
3413 | if (ret < 0) | |
3414 | return ret; | |
3415 | return 0; | |
64e7c440 SR |
3416 | } |
3417 | ||
f6180773 | 3418 | /* command found */ |
64e7c440 SR |
3419 | |
3420 | command = strsep(&next, ":"); | |
3421 | ||
f6180773 SR |
3422 | mutex_lock(&ftrace_cmd_mutex); |
3423 | list_for_each_entry(p, &ftrace_commands, list) { | |
3424 | if (strcmp(p->name, command) == 0) { | |
43dd61c9 | 3425 | ret = p->func(hash, func, command, next, enable); |
f6180773 SR |
3426 | goto out_unlock; |
3427 | } | |
64e7c440 | 3428 | } |
f6180773 SR |
3429 | out_unlock: |
3430 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 3431 | |
f6180773 | 3432 | return ret; |
64e7c440 SR |
3433 | } |
3434 | ||
e309b41d | 3435 | static ssize_t |
41c52c0d SR |
3436 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
3437 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
3438 | { |
3439 | struct ftrace_iterator *iter; | |
689fd8b6 | 3440 | struct trace_parser *parser; |
3441 | ssize_t ret, read; | |
5072c59f | 3442 | |
4ba7978e | 3443 | if (!cnt) |
5072c59f SR |
3444 | return 0; |
3445 | ||
5072c59f SR |
3446 | if (file->f_mode & FMODE_READ) { |
3447 | struct seq_file *m = file->private_data; | |
3448 | iter = m->private; | |
3449 | } else | |
3450 | iter = file->private_data; | |
3451 | ||
f04f24fb | 3452 | if (unlikely(ftrace_disabled)) |
3f2367ba MH |
3453 | return -ENODEV; |
3454 | ||
3455 | /* iter->hash is a local copy, so we don't need regex_lock */ | |
f04f24fb | 3456 | |
689fd8b6 | 3457 | parser = &iter->parser; |
3458 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 3459 | |
4ba7978e | 3460 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 3461 | !trace_parser_cont(parser)) { |
33dc9b12 | 3462 | ret = ftrace_process_regex(iter->hash, parser->buffer, |
689fd8b6 | 3463 | parser->idx, enable); |
313254a9 | 3464 | trace_parser_clear(parser); |
7c088b51 | 3465 | if (ret < 0) |
3f2367ba | 3466 | goto out; |
eda1e328 | 3467 | } |
5072c59f | 3468 | |
5072c59f | 3469 | ret = read; |
3f2367ba | 3470 | out: |
5072c59f SR |
3471 | return ret; |
3472 | } | |
3473 | ||
fc13cb0c | 3474 | ssize_t |
41c52c0d SR |
3475 | ftrace_filter_write(struct file *file, const char __user *ubuf, |
3476 | size_t cnt, loff_t *ppos) | |
3477 | { | |
3478 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
3479 | } | |
3480 | ||
fc13cb0c | 3481 | ssize_t |
41c52c0d SR |
3482 | ftrace_notrace_write(struct file *file, const char __user *ubuf, |
3483 | size_t cnt, loff_t *ppos) | |
3484 | { | |
3485 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
3486 | } | |
3487 | ||
33dc9b12 | 3488 | static int |
647664ea MH |
3489 | ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) |
3490 | { | |
3491 | struct ftrace_func_entry *entry; | |
3492 | ||
3493 | if (!ftrace_location(ip)) | |
3494 | return -EINVAL; | |
3495 | ||
3496 | if (remove) { | |
3497 | entry = ftrace_lookup_ip(hash, ip); | |
3498 | if (!entry) | |
3499 | return -ENOENT; | |
3500 | free_hash_entry(hash, entry); | |
3501 | return 0; | |
3502 | } | |
3503 | ||
3504 | return add_hash_entry(hash, ip); | |
3505 | } | |
3506 | ||
1c80c432 SRRH |
3507 | static void ftrace_ops_update_code(struct ftrace_ops *ops) |
3508 | { | |
3509 | if (ops->flags & FTRACE_OPS_FL_ENABLED && ftrace_enabled) | |
3510 | ftrace_run_update_code(FTRACE_UPDATE_CALLS); | |
3511 | } | |
3512 | ||
647664ea MH |
3513 | static int |
3514 | ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, | |
3515 | unsigned long ip, int remove, int reset, int enable) | |
41c52c0d | 3516 | { |
33dc9b12 | 3517 | struct ftrace_hash **orig_hash; |
f45948e8 | 3518 | struct ftrace_hash *hash; |
33dc9b12 | 3519 | int ret; |
f45948e8 | 3520 | |
936e074b SR |
3521 | /* All global ops uses the global ops filters */ |
3522 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) | |
3523 | ops = &global_ops; | |
3524 | ||
41c52c0d | 3525 | if (unlikely(ftrace_disabled)) |
33dc9b12 | 3526 | return -ENODEV; |
41c52c0d | 3527 | |
3f2367ba MH |
3528 | mutex_lock(&ops->regex_lock); |
3529 | ||
f45948e8 | 3530 | if (enable) |
33dc9b12 | 3531 | orig_hash = &ops->filter_hash; |
f45948e8 | 3532 | else |
33dc9b12 SR |
3533 | orig_hash = &ops->notrace_hash; |
3534 | ||
3535 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
3f2367ba MH |
3536 | if (!hash) { |
3537 | ret = -ENOMEM; | |
3538 | goto out_regex_unlock; | |
3539 | } | |
f45948e8 | 3540 | |
41c52c0d | 3541 | if (reset) |
1cf41dd7 | 3542 | ftrace_filter_reset(hash); |
ac483c44 JO |
3543 | if (buf && !ftrace_match_records(hash, buf, len)) { |
3544 | ret = -EINVAL; | |
3545 | goto out_regex_unlock; | |
3546 | } | |
647664ea MH |
3547 | if (ip) { |
3548 | ret = ftrace_match_addr(hash, ip, remove); | |
3549 | if (ret < 0) | |
3550 | goto out_regex_unlock; | |
3551 | } | |
33dc9b12 SR |
3552 | |
3553 | mutex_lock(&ftrace_lock); | |
41fb61c2 | 3554 | ret = ftrace_hash_move(ops, enable, orig_hash, hash); |
1c80c432 SRRH |
3555 | if (!ret) |
3556 | ftrace_ops_update_code(ops); | |
072126f4 | 3557 | |
33dc9b12 SR |
3558 | mutex_unlock(&ftrace_lock); |
3559 | ||
ac483c44 | 3560 | out_regex_unlock: |
f04f24fb | 3561 | mutex_unlock(&ops->regex_lock); |
33dc9b12 SR |
3562 | |
3563 | free_ftrace_hash(hash); | |
3564 | return ret; | |
41c52c0d SR |
3565 | } |
3566 | ||
647664ea MH |
3567 | static int |
3568 | ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove, | |
3569 | int reset, int enable) | |
3570 | { | |
3571 | return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable); | |
3572 | } | |
3573 | ||
3574 | /** | |
3575 | * ftrace_set_filter_ip - set a function to filter on in ftrace by address | |
3576 | * @ops - the ops to set the filter with | |
3577 | * @ip - the address to add to or remove from the filter. | |
3578 | * @remove - non zero to remove the ip from the filter | |
3579 | * @reset - non zero to reset all filters before applying this filter. | |
3580 | * | |
3581 | * Filters denote which functions should be enabled when tracing is enabled | |
3582 | * If @ip is NULL, it failes to update filter. | |
3583 | */ | |
3584 | int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, | |
3585 | int remove, int reset) | |
3586 | { | |
f04f24fb | 3587 | ftrace_ops_init(ops); |
647664ea MH |
3588 | return ftrace_set_addr(ops, ip, remove, reset, 1); |
3589 | } | |
3590 | EXPORT_SYMBOL_GPL(ftrace_set_filter_ip); | |
3591 | ||
3592 | static int | |
3593 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, | |
3594 | int reset, int enable) | |
3595 | { | |
3596 | return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable); | |
3597 | } | |
3598 | ||
77a2b37d SR |
3599 | /** |
3600 | * ftrace_set_filter - set a function to filter on in ftrace | |
936e074b SR |
3601 | * @ops - the ops to set the filter with |
3602 | * @buf - the string that holds the function filter text. | |
3603 | * @len - the length of the string. | |
3604 | * @reset - non zero to reset all filters before applying this filter. | |
3605 | * | |
3606 | * Filters denote which functions should be enabled when tracing is enabled. | |
3607 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
3608 | */ | |
ac483c44 | 3609 | int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
3610 | int len, int reset) |
3611 | { | |
f04f24fb | 3612 | ftrace_ops_init(ops); |
ac483c44 | 3613 | return ftrace_set_regex(ops, buf, len, reset, 1); |
936e074b SR |
3614 | } |
3615 | EXPORT_SYMBOL_GPL(ftrace_set_filter); | |
3616 | ||
3617 | /** | |
3618 | * ftrace_set_notrace - set a function to not trace in ftrace | |
3619 | * @ops - the ops to set the notrace filter with | |
3620 | * @buf - the string that holds the function notrace text. | |
3621 | * @len - the length of the string. | |
3622 | * @reset - non zero to reset all filters before applying this filter. | |
3623 | * | |
3624 | * Notrace Filters denote which functions should not be enabled when tracing | |
3625 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
3626 | * for tracing. | |
3627 | */ | |
ac483c44 | 3628 | int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
3629 | int len, int reset) |
3630 | { | |
f04f24fb | 3631 | ftrace_ops_init(ops); |
ac483c44 | 3632 | return ftrace_set_regex(ops, buf, len, reset, 0); |
936e074b SR |
3633 | } |
3634 | EXPORT_SYMBOL_GPL(ftrace_set_notrace); | |
3635 | /** | |
3636 | * ftrace_set_filter - set a function to filter on in ftrace | |
3637 | * @ops - the ops to set the filter with | |
77a2b37d SR |
3638 | * @buf - the string that holds the function filter text. |
3639 | * @len - the length of the string. | |
3640 | * @reset - non zero to reset all filters before applying this filter. | |
3641 | * | |
3642 | * Filters denote which functions should be enabled when tracing is enabled. | |
3643 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
3644 | */ | |
936e074b | 3645 | void ftrace_set_global_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 3646 | { |
f45948e8 | 3647 | ftrace_set_regex(&global_ops, buf, len, reset, 1); |
41c52c0d | 3648 | } |
936e074b | 3649 | EXPORT_SYMBOL_GPL(ftrace_set_global_filter); |
4eebcc81 | 3650 | |
41c52c0d SR |
3651 | /** |
3652 | * ftrace_set_notrace - set a function to not trace in ftrace | |
936e074b | 3653 | * @ops - the ops to set the notrace filter with |
41c52c0d SR |
3654 | * @buf - the string that holds the function notrace text. |
3655 | * @len - the length of the string. | |
3656 | * @reset - non zero to reset all filters before applying this filter. | |
3657 | * | |
3658 | * Notrace Filters denote which functions should not be enabled when tracing | |
3659 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
3660 | * for tracing. | |
3661 | */ | |
936e074b | 3662 | void ftrace_set_global_notrace(unsigned char *buf, int len, int reset) |
41c52c0d | 3663 | { |
f45948e8 | 3664 | ftrace_set_regex(&global_ops, buf, len, reset, 0); |
77a2b37d | 3665 | } |
936e074b | 3666 | EXPORT_SYMBOL_GPL(ftrace_set_global_notrace); |
77a2b37d | 3667 | |
2af15d6a SR |
3668 | /* |
3669 | * command line interface to allow users to set filters on boot up. | |
3670 | */ | |
3671 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
3672 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
3673 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
3674 | ||
f1ed7c74 SRRH |
3675 | /* Used by function selftest to not test if filter is set */ |
3676 | bool ftrace_filter_param __initdata; | |
3677 | ||
2af15d6a SR |
3678 | static int __init set_ftrace_notrace(char *str) |
3679 | { | |
f1ed7c74 | 3680 | ftrace_filter_param = true; |
75761cc1 | 3681 | strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
3682 | return 1; |
3683 | } | |
3684 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
3685 | ||
3686 | static int __init set_ftrace_filter(char *str) | |
3687 | { | |
f1ed7c74 | 3688 | ftrace_filter_param = true; |
75761cc1 | 3689 | strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
3690 | return 1; |
3691 | } | |
3692 | __setup("ftrace_filter=", set_ftrace_filter); | |
3693 | ||
369bc18f | 3694 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 3695 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
faf982a6 | 3696 | static int ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer); |
801c29fd | 3697 | |
369bc18f SA |
3698 | static int __init set_graph_function(char *str) |
3699 | { | |
06f43d66 | 3700 | strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
3701 | return 1; |
3702 | } | |
3703 | __setup("ftrace_graph_filter=", set_graph_function); | |
3704 | ||
3705 | static void __init set_ftrace_early_graph(char *buf) | |
3706 | { | |
3707 | int ret; | |
3708 | char *func; | |
3709 | ||
3710 | while (buf) { | |
3711 | func = strsep(&buf, ","); | |
3712 | /* we allow only one expression at a time */ | |
3713 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, | |
faf982a6 | 3714 | FTRACE_GRAPH_MAX_FUNCS, func); |
369bc18f SA |
3715 | if (ret) |
3716 | printk(KERN_DEBUG "ftrace: function %s not " | |
3717 | "traceable\n", func); | |
3718 | } | |
3719 | } | |
3720 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
3721 | ||
2a85a37f SR |
3722 | void __init |
3723 | ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable) | |
2af15d6a SR |
3724 | { |
3725 | char *func; | |
3726 | ||
f04f24fb MH |
3727 | ftrace_ops_init(ops); |
3728 | ||
2af15d6a SR |
3729 | while (buf) { |
3730 | func = strsep(&buf, ","); | |
f45948e8 | 3731 | ftrace_set_regex(ops, func, strlen(func), 0, enable); |
2af15d6a SR |
3732 | } |
3733 | } | |
3734 | ||
3735 | static void __init set_ftrace_early_filters(void) | |
3736 | { | |
3737 | if (ftrace_filter_buf[0]) | |
2a85a37f | 3738 | ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1); |
2af15d6a | 3739 | if (ftrace_notrace_buf[0]) |
2a85a37f | 3740 | ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0); |
369bc18f SA |
3741 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
3742 | if (ftrace_graph_buf[0]) | |
3743 | set_ftrace_early_graph(ftrace_graph_buf); | |
3744 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2af15d6a SR |
3745 | } |
3746 | ||
fc13cb0c | 3747 | int ftrace_regex_release(struct inode *inode, struct file *file) |
5072c59f SR |
3748 | { |
3749 | struct seq_file *m = (struct seq_file *)file->private_data; | |
3750 | struct ftrace_iterator *iter; | |
33dc9b12 | 3751 | struct ftrace_hash **orig_hash; |
689fd8b6 | 3752 | struct trace_parser *parser; |
ed926f9b | 3753 | int filter_hash; |
33dc9b12 | 3754 | int ret; |
5072c59f | 3755 | |
5072c59f SR |
3756 | if (file->f_mode & FMODE_READ) { |
3757 | iter = m->private; | |
5072c59f SR |
3758 | seq_release(inode, file); |
3759 | } else | |
3760 | iter = file->private_data; | |
3761 | ||
689fd8b6 | 3762 | parser = &iter->parser; |
3763 | if (trace_parser_loaded(parser)) { | |
3764 | parser->buffer[parser->idx] = 0; | |
1cf41dd7 | 3765 | ftrace_match_records(iter->hash, parser->buffer, parser->idx); |
5072c59f SR |
3766 | } |
3767 | ||
689fd8b6 | 3768 | trace_parser_put(parser); |
689fd8b6 | 3769 | |
3f2367ba MH |
3770 | mutex_lock(&iter->ops->regex_lock); |
3771 | ||
058e297d | 3772 | if (file->f_mode & FMODE_WRITE) { |
ed926f9b SR |
3773 | filter_hash = !!(iter->flags & FTRACE_ITER_FILTER); |
3774 | ||
3775 | if (filter_hash) | |
33dc9b12 | 3776 | orig_hash = &iter->ops->filter_hash; |
ed926f9b SR |
3777 | else |
3778 | orig_hash = &iter->ops->notrace_hash; | |
33dc9b12 | 3779 | |
058e297d | 3780 | mutex_lock(&ftrace_lock); |
41fb61c2 SR |
3781 | ret = ftrace_hash_move(iter->ops, filter_hash, |
3782 | orig_hash, iter->hash); | |
1c80c432 SRRH |
3783 | if (!ret) |
3784 | ftrace_ops_update_code(iter->ops); | |
41fb61c2 | 3785 | |
058e297d SR |
3786 | mutex_unlock(&ftrace_lock); |
3787 | } | |
3f2367ba MH |
3788 | |
3789 | mutex_unlock(&iter->ops->regex_lock); | |
33dc9b12 SR |
3790 | free_ftrace_hash(iter->hash); |
3791 | kfree(iter); | |
058e297d | 3792 | |
5072c59f SR |
3793 | return 0; |
3794 | } | |
3795 | ||
5e2336a0 | 3796 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
3797 | .open = ftrace_avail_open, |
3798 | .read = seq_read, | |
3799 | .llseek = seq_lseek, | |
3be04b47 | 3800 | .release = seq_release_private, |
5072c59f SR |
3801 | }; |
3802 | ||
647bcd03 SR |
3803 | static const struct file_operations ftrace_enabled_fops = { |
3804 | .open = ftrace_enabled_open, | |
3805 | .read = seq_read, | |
3806 | .llseek = seq_lseek, | |
3807 | .release = seq_release_private, | |
3808 | }; | |
3809 | ||
5e2336a0 | 3810 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 3811 | .open = ftrace_filter_open, |
850a80cf | 3812 | .read = seq_read, |
5072c59f | 3813 | .write = ftrace_filter_write, |
098c879e | 3814 | .llseek = tracing_lseek, |
1cf41dd7 | 3815 | .release = ftrace_regex_release, |
5072c59f SR |
3816 | }; |
3817 | ||
5e2336a0 | 3818 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 3819 | .open = ftrace_notrace_open, |
850a80cf | 3820 | .read = seq_read, |
41c52c0d | 3821 | .write = ftrace_notrace_write, |
098c879e | 3822 | .llseek = tracing_lseek, |
1cf41dd7 | 3823 | .release = ftrace_regex_release, |
41c52c0d SR |
3824 | }; |
3825 | ||
ea4e2bc4 SR |
3826 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
3827 | ||
3828 | static DEFINE_MUTEX(graph_lock); | |
3829 | ||
3830 | int ftrace_graph_count; | |
29ad23b0 | 3831 | int ftrace_graph_notrace_count; |
ea4e2bc4 | 3832 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
29ad23b0 | 3833 | unsigned long ftrace_graph_notrace_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
ea4e2bc4 | 3834 | |
faf982a6 NK |
3835 | struct ftrace_graph_data { |
3836 | unsigned long *table; | |
3837 | size_t size; | |
3838 | int *count; | |
3839 | const struct seq_operations *seq_ops; | |
3840 | }; | |
3841 | ||
ea4e2bc4 | 3842 | static void * |
85951842 | 3843 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 3844 | { |
faf982a6 NK |
3845 | struct ftrace_graph_data *fgd = m->private; |
3846 | ||
3847 | if (*pos >= *fgd->count) | |
ea4e2bc4 | 3848 | return NULL; |
faf982a6 | 3849 | return &fgd->table[*pos]; |
85951842 | 3850 | } |
ea4e2bc4 | 3851 | |
85951842 LZ |
3852 | static void * |
3853 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
3854 | { | |
3855 | (*pos)++; | |
3856 | return __g_next(m, pos); | |
ea4e2bc4 SR |
3857 | } |
3858 | ||
3859 | static void *g_start(struct seq_file *m, loff_t *pos) | |
3860 | { | |
faf982a6 NK |
3861 | struct ftrace_graph_data *fgd = m->private; |
3862 | ||
ea4e2bc4 SR |
3863 | mutex_lock(&graph_lock); |
3864 | ||
f9349a8f | 3865 | /* Nothing, tell g_show to print all functions are enabled */ |
faf982a6 | 3866 | if (!*fgd->count && !*pos) |
f9349a8f FW |
3867 | return (void *)1; |
3868 | ||
85951842 | 3869 | return __g_next(m, pos); |
ea4e2bc4 SR |
3870 | } |
3871 | ||
3872 | static void g_stop(struct seq_file *m, void *p) | |
3873 | { | |
3874 | mutex_unlock(&graph_lock); | |
3875 | } | |
3876 | ||
3877 | static int g_show(struct seq_file *m, void *v) | |
3878 | { | |
3879 | unsigned long *ptr = v; | |
ea4e2bc4 SR |
3880 | |
3881 | if (!ptr) | |
3882 | return 0; | |
3883 | ||
f9349a8f FW |
3884 | if (ptr == (unsigned long *)1) { |
3885 | seq_printf(m, "#### all functions enabled ####\n"); | |
3886 | return 0; | |
3887 | } | |
3888 | ||
b375a11a | 3889 | seq_printf(m, "%ps\n", (void *)*ptr); |
ea4e2bc4 SR |
3890 | |
3891 | return 0; | |
3892 | } | |
3893 | ||
88e9d34c | 3894 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
3895 | .start = g_start, |
3896 | .next = g_next, | |
3897 | .stop = g_stop, | |
3898 | .show = g_show, | |
3899 | }; | |
3900 | ||
3901 | static int | |
faf982a6 NK |
3902 | __ftrace_graph_open(struct inode *inode, struct file *file, |
3903 | struct ftrace_graph_data *fgd) | |
ea4e2bc4 SR |
3904 | { |
3905 | int ret = 0; | |
3906 | ||
ea4e2bc4 SR |
3907 | mutex_lock(&graph_lock); |
3908 | if ((file->f_mode & FMODE_WRITE) && | |
8650ae32 | 3909 | (file->f_flags & O_TRUNC)) { |
faf982a6 NK |
3910 | *fgd->count = 0; |
3911 | memset(fgd->table, 0, fgd->size * sizeof(*fgd->table)); | |
ea4e2bc4 | 3912 | } |
a4ec5e0c | 3913 | mutex_unlock(&graph_lock); |
ea4e2bc4 | 3914 | |
faf982a6 NK |
3915 | if (file->f_mode & FMODE_READ) { |
3916 | ret = seq_open(file, fgd->seq_ops); | |
3917 | if (!ret) { | |
3918 | struct seq_file *m = file->private_data; | |
3919 | m->private = fgd; | |
3920 | } | |
3921 | } else | |
3922 | file->private_data = fgd; | |
ea4e2bc4 SR |
3923 | |
3924 | return ret; | |
3925 | } | |
3926 | ||
faf982a6 NK |
3927 | static int |
3928 | ftrace_graph_open(struct inode *inode, struct file *file) | |
3929 | { | |
3930 | struct ftrace_graph_data *fgd; | |
3931 | ||
3932 | if (unlikely(ftrace_disabled)) | |
3933 | return -ENODEV; | |
3934 | ||
3935 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
3936 | if (fgd == NULL) | |
3937 | return -ENOMEM; | |
3938 | ||
3939 | fgd->table = ftrace_graph_funcs; | |
3940 | fgd->size = FTRACE_GRAPH_MAX_FUNCS; | |
3941 | fgd->count = &ftrace_graph_count; | |
3942 | fgd->seq_ops = &ftrace_graph_seq_ops; | |
3943 | ||
3944 | return __ftrace_graph_open(inode, file, fgd); | |
3945 | } | |
3946 | ||
29ad23b0 NK |
3947 | static int |
3948 | ftrace_graph_notrace_open(struct inode *inode, struct file *file) | |
3949 | { | |
3950 | struct ftrace_graph_data *fgd; | |
3951 | ||
3952 | if (unlikely(ftrace_disabled)) | |
3953 | return -ENODEV; | |
3954 | ||
3955 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
3956 | if (fgd == NULL) | |
3957 | return -ENOMEM; | |
3958 | ||
3959 | fgd->table = ftrace_graph_notrace_funcs; | |
3960 | fgd->size = FTRACE_GRAPH_MAX_FUNCS; | |
3961 | fgd->count = &ftrace_graph_notrace_count; | |
3962 | fgd->seq_ops = &ftrace_graph_seq_ops; | |
3963 | ||
3964 | return __ftrace_graph_open(inode, file, fgd); | |
3965 | } | |
3966 | ||
87827111 LZ |
3967 | static int |
3968 | ftrace_graph_release(struct inode *inode, struct file *file) | |
3969 | { | |
faf982a6 NK |
3970 | if (file->f_mode & FMODE_READ) { |
3971 | struct seq_file *m = file->private_data; | |
3972 | ||
3973 | kfree(m->private); | |
87827111 | 3974 | seq_release(inode, file); |
faf982a6 NK |
3975 | } else { |
3976 | kfree(file->private_data); | |
3977 | } | |
3978 | ||
87827111 LZ |
3979 | return 0; |
3980 | } | |
3981 | ||
ea4e2bc4 | 3982 | static int |
faf982a6 | 3983 | ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer) |
ea4e2bc4 | 3984 | { |
ea4e2bc4 SR |
3985 | struct dyn_ftrace *rec; |
3986 | struct ftrace_page *pg; | |
f9349a8f | 3987 | int search_len; |
c7c6b1fe | 3988 | int fail = 1; |
f9349a8f FW |
3989 | int type, not; |
3990 | char *search; | |
3991 | bool exists; | |
3992 | int i; | |
ea4e2bc4 | 3993 | |
f9349a8f | 3994 | /* decode regex */ |
3f6fe06d | 3995 | type = filter_parse_regex(buffer, strlen(buffer), &search, ¬); |
faf982a6 | 3996 | if (!not && *idx >= size) |
c7c6b1fe | 3997 | return -EBUSY; |
f9349a8f FW |
3998 | |
3999 | search_len = strlen(search); | |
4000 | ||
52baf119 | 4001 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
4002 | |
4003 | if (unlikely(ftrace_disabled)) { | |
4004 | mutex_unlock(&ftrace_lock); | |
4005 | return -ENODEV; | |
4006 | } | |
4007 | ||
265c831c SR |
4008 | do_for_each_ftrace_rec(pg, rec) { |
4009 | ||
b9df92d2 | 4010 | if (ftrace_match_record(rec, NULL, search, search_len, type)) { |
c7c6b1fe | 4011 | /* if it is in the array */ |
f9349a8f | 4012 | exists = false; |
c7c6b1fe | 4013 | for (i = 0; i < *idx; i++) { |
f9349a8f FW |
4014 | if (array[i] == rec->ip) { |
4015 | exists = true; | |
265c831c SR |
4016 | break; |
4017 | } | |
c7c6b1fe LZ |
4018 | } |
4019 | ||
4020 | if (!not) { | |
4021 | fail = 0; | |
4022 | if (!exists) { | |
4023 | array[(*idx)++] = rec->ip; | |
faf982a6 | 4024 | if (*idx >= size) |
c7c6b1fe LZ |
4025 | goto out; |
4026 | } | |
4027 | } else { | |
4028 | if (exists) { | |
4029 | array[i] = array[--(*idx)]; | |
4030 | array[*idx] = 0; | |
4031 | fail = 0; | |
4032 | } | |
4033 | } | |
ea4e2bc4 | 4034 | } |
265c831c | 4035 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 4036 | out: |
52baf119 | 4037 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 4038 | |
c7c6b1fe LZ |
4039 | if (fail) |
4040 | return -EINVAL; | |
4041 | ||
c7c6b1fe | 4042 | return 0; |
ea4e2bc4 SR |
4043 | } |
4044 | ||
4045 | static ssize_t | |
4046 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
4047 | size_t cnt, loff_t *ppos) | |
4048 | { | |
689fd8b6 | 4049 | struct trace_parser parser; |
6a10108b | 4050 | ssize_t read, ret = 0; |
faf982a6 | 4051 | struct ftrace_graph_data *fgd = file->private_data; |
ea4e2bc4 | 4052 | |
c7c6b1fe | 4053 | if (!cnt) |
ea4e2bc4 SR |
4054 | return 0; |
4055 | ||
6a10108b NK |
4056 | if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) |
4057 | return -ENOMEM; | |
ea4e2bc4 | 4058 | |
689fd8b6 | 4059 | read = trace_get_user(&parser, ubuf, cnt, ppos); |
ea4e2bc4 | 4060 | |
4ba7978e | 4061 | if (read >= 0 && trace_parser_loaded((&parser))) { |
689fd8b6 | 4062 | parser.buffer[parser.idx] = 0; |
4063 | ||
6a10108b NK |
4064 | mutex_lock(&graph_lock); |
4065 | ||
689fd8b6 | 4066 | /* we allow only one expression at a time */ |
faf982a6 NK |
4067 | ret = ftrace_set_func(fgd->table, fgd->count, fgd->size, |
4068 | parser.buffer); | |
6a10108b NK |
4069 | |
4070 | mutex_unlock(&graph_lock); | |
ea4e2bc4 | 4071 | } |
ea4e2bc4 | 4072 | |
6a10108b NK |
4073 | if (!ret) |
4074 | ret = read; | |
1eb90f13 | 4075 | |
689fd8b6 | 4076 | trace_parser_put(&parser); |
ea4e2bc4 SR |
4077 | |
4078 | return ret; | |
4079 | } | |
4080 | ||
4081 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
4082 | .open = ftrace_graph_open, |
4083 | .read = seq_read, | |
4084 | .write = ftrace_graph_write, | |
098c879e | 4085 | .llseek = tracing_lseek, |
87827111 | 4086 | .release = ftrace_graph_release, |
ea4e2bc4 | 4087 | }; |
29ad23b0 NK |
4088 | |
4089 | static const struct file_operations ftrace_graph_notrace_fops = { | |
4090 | .open = ftrace_graph_notrace_open, | |
4091 | .read = seq_read, | |
4092 | .write = ftrace_graph_write, | |
098c879e | 4093 | .llseek = tracing_lseek, |
29ad23b0 NK |
4094 | .release = ftrace_graph_release, |
4095 | }; | |
ea4e2bc4 SR |
4096 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
4097 | ||
df4fc315 | 4098 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 4099 | { |
5072c59f | 4100 | |
5452af66 FW |
4101 | trace_create_file("available_filter_functions", 0444, |
4102 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 4103 | |
647bcd03 SR |
4104 | trace_create_file("enabled_functions", 0444, |
4105 | d_tracer, NULL, &ftrace_enabled_fops); | |
4106 | ||
5452af66 FW |
4107 | trace_create_file("set_ftrace_filter", 0644, d_tracer, |
4108 | NULL, &ftrace_filter_fops); | |
41c52c0d | 4109 | |
5452af66 | 4110 | trace_create_file("set_ftrace_notrace", 0644, d_tracer, |
41c52c0d | 4111 | NULL, &ftrace_notrace_fops); |
ad90c0e3 | 4112 | |
ea4e2bc4 | 4113 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5452af66 | 4114 | trace_create_file("set_graph_function", 0444, d_tracer, |
ea4e2bc4 SR |
4115 | NULL, |
4116 | &ftrace_graph_fops); | |
29ad23b0 NK |
4117 | trace_create_file("set_graph_notrace", 0444, d_tracer, |
4118 | NULL, | |
4119 | &ftrace_graph_notrace_fops); | |
ea4e2bc4 SR |
4120 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
4121 | ||
5072c59f SR |
4122 | return 0; |
4123 | } | |
4124 | ||
9fd49328 | 4125 | static int ftrace_cmp_ips(const void *a, const void *b) |
68950619 | 4126 | { |
9fd49328 SR |
4127 | const unsigned long *ipa = a; |
4128 | const unsigned long *ipb = b; | |
68950619 | 4129 | |
9fd49328 SR |
4130 | if (*ipa > *ipb) |
4131 | return 1; | |
4132 | if (*ipa < *ipb) | |
4133 | return -1; | |
4134 | return 0; | |
4135 | } | |
4136 | ||
4137 | static void ftrace_swap_ips(void *a, void *b, int size) | |
4138 | { | |
4139 | unsigned long *ipa = a; | |
4140 | unsigned long *ipb = b; | |
4141 | unsigned long t; | |
4142 | ||
4143 | t = *ipa; | |
4144 | *ipa = *ipb; | |
4145 | *ipb = t; | |
68950619 SR |
4146 | } |
4147 | ||
5cb084bb | 4148 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 4149 | unsigned long *start, |
68bf21aa SR |
4150 | unsigned long *end) |
4151 | { | |
706c81f8 | 4152 | struct ftrace_page *start_pg; |
a7900875 | 4153 | struct ftrace_page *pg; |
706c81f8 | 4154 | struct dyn_ftrace *rec; |
a7900875 | 4155 | unsigned long count; |
68bf21aa SR |
4156 | unsigned long *p; |
4157 | unsigned long addr; | |
4376cac6 | 4158 | unsigned long flags = 0; /* Shut up gcc */ |
a7900875 SR |
4159 | int ret = -ENOMEM; |
4160 | ||
4161 | count = end - start; | |
4162 | ||
4163 | if (!count) | |
4164 | return 0; | |
4165 | ||
9fd49328 SR |
4166 | sort(start, count, sizeof(*start), |
4167 | ftrace_cmp_ips, ftrace_swap_ips); | |
4168 | ||
706c81f8 SR |
4169 | start_pg = ftrace_allocate_pages(count); |
4170 | if (!start_pg) | |
a7900875 | 4171 | return -ENOMEM; |
68bf21aa | 4172 | |
e6ea44e9 | 4173 | mutex_lock(&ftrace_lock); |
a7900875 | 4174 | |
32082309 SR |
4175 | /* |
4176 | * Core and each module needs their own pages, as | |
4177 | * modules will free them when they are removed. | |
4178 | * Force a new page to be allocated for modules. | |
4179 | */ | |
a7900875 SR |
4180 | if (!mod) { |
4181 | WARN_ON(ftrace_pages || ftrace_pages_start); | |
4182 | /* First initialization */ | |
706c81f8 | 4183 | ftrace_pages = ftrace_pages_start = start_pg; |
a7900875 | 4184 | } else { |
32082309 | 4185 | if (!ftrace_pages) |
a7900875 | 4186 | goto out; |
32082309 | 4187 | |
a7900875 SR |
4188 | if (WARN_ON(ftrace_pages->next)) { |
4189 | /* Hmm, we have free pages? */ | |
4190 | while (ftrace_pages->next) | |
4191 | ftrace_pages = ftrace_pages->next; | |
32082309 | 4192 | } |
a7900875 | 4193 | |
706c81f8 | 4194 | ftrace_pages->next = start_pg; |
32082309 SR |
4195 | } |
4196 | ||
68bf21aa | 4197 | p = start; |
706c81f8 | 4198 | pg = start_pg; |
68bf21aa SR |
4199 | while (p < end) { |
4200 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
4201 | /* |
4202 | * Some architecture linkers will pad between | |
4203 | * the different mcount_loc sections of different | |
4204 | * object files to satisfy alignments. | |
4205 | * Skip any NULL pointers. | |
4206 | */ | |
4207 | if (!addr) | |
4208 | continue; | |
706c81f8 SR |
4209 | |
4210 | if (pg->index == pg->size) { | |
4211 | /* We should have allocated enough */ | |
4212 | if (WARN_ON(!pg->next)) | |
4213 | break; | |
4214 | pg = pg->next; | |
4215 | } | |
4216 | ||
4217 | rec = &pg->records[pg->index++]; | |
4218 | rec->ip = addr; | |
68bf21aa SR |
4219 | } |
4220 | ||
706c81f8 SR |
4221 | /* We should have used all pages */ |
4222 | WARN_ON(pg->next); | |
4223 | ||
4224 | /* Assign the last page to ftrace_pages */ | |
4225 | ftrace_pages = pg; | |
4226 | ||
85ae32ae | 4227 | /* These new locations need to be initialized */ |
706c81f8 | 4228 | ftrace_new_pgs = start_pg; |
85ae32ae | 4229 | |
a4f18ed1 | 4230 | /* |
4376cac6 SR |
4231 | * We only need to disable interrupts on start up |
4232 | * because we are modifying code that an interrupt | |
4233 | * may execute, and the modification is not atomic. | |
4234 | * But for modules, nothing runs the code we modify | |
4235 | * until we are finished with it, and there's no | |
4236 | * reason to cause large interrupt latencies while we do it. | |
a4f18ed1 | 4237 | */ |
4376cac6 SR |
4238 | if (!mod) |
4239 | local_irq_save(flags); | |
31e88909 | 4240 | ftrace_update_code(mod); |
4376cac6 SR |
4241 | if (!mod) |
4242 | local_irq_restore(flags); | |
a7900875 SR |
4243 | ret = 0; |
4244 | out: | |
e6ea44e9 | 4245 | mutex_unlock(&ftrace_lock); |
68bf21aa | 4246 | |
a7900875 | 4247 | return ret; |
68bf21aa SR |
4248 | } |
4249 | ||
93eb677d | 4250 | #ifdef CONFIG_MODULES |
32082309 SR |
4251 | |
4252 | #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next) | |
4253 | ||
e7247a15 | 4254 | void ftrace_release_mod(struct module *mod) |
93eb677d SR |
4255 | { |
4256 | struct dyn_ftrace *rec; | |
32082309 | 4257 | struct ftrace_page **last_pg; |
93eb677d | 4258 | struct ftrace_page *pg; |
a7900875 | 4259 | int order; |
93eb677d | 4260 | |
45a4a237 SR |
4261 | mutex_lock(&ftrace_lock); |
4262 | ||
e7247a15 | 4263 | if (ftrace_disabled) |
45a4a237 | 4264 | goto out_unlock; |
93eb677d | 4265 | |
32082309 SR |
4266 | /* |
4267 | * Each module has its own ftrace_pages, remove | |
4268 | * them from the list. | |
4269 | */ | |
4270 | last_pg = &ftrace_pages_start; | |
4271 | for (pg = ftrace_pages_start; pg; pg = *last_pg) { | |
4272 | rec = &pg->records[0]; | |
e7247a15 | 4273 | if (within_module_core(rec->ip, mod)) { |
93eb677d | 4274 | /* |
32082309 SR |
4275 | * As core pages are first, the first |
4276 | * page should never be a module page. | |
93eb677d | 4277 | */ |
32082309 SR |
4278 | if (WARN_ON(pg == ftrace_pages_start)) |
4279 | goto out_unlock; | |
4280 | ||
4281 | /* Check if we are deleting the last page */ | |
4282 | if (pg == ftrace_pages) | |
4283 | ftrace_pages = next_to_ftrace_page(last_pg); | |
4284 | ||
4285 | *last_pg = pg->next; | |
a7900875 SR |
4286 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
4287 | free_pages((unsigned long)pg->records, order); | |
4288 | kfree(pg); | |
32082309 SR |
4289 | } else |
4290 | last_pg = &pg->next; | |
4291 | } | |
45a4a237 | 4292 | out_unlock: |
93eb677d SR |
4293 | mutex_unlock(&ftrace_lock); |
4294 | } | |
4295 | ||
4296 | static void ftrace_init_module(struct module *mod, | |
4297 | unsigned long *start, unsigned long *end) | |
90d595fe | 4298 | { |
00fd61ae | 4299 | if (ftrace_disabled || start == end) |
fed1939c | 4300 | return; |
5cb084bb | 4301 | ftrace_process_locs(mod, start, end); |
90d595fe SR |
4302 | } |
4303 | ||
8c189ea6 SRRH |
4304 | static int ftrace_module_notify_enter(struct notifier_block *self, |
4305 | unsigned long val, void *data) | |
93eb677d SR |
4306 | { |
4307 | struct module *mod = data; | |
4308 | ||
8c189ea6 | 4309 | if (val == MODULE_STATE_COMING) |
93eb677d SR |
4310 | ftrace_init_module(mod, mod->ftrace_callsites, |
4311 | mod->ftrace_callsites + | |
4312 | mod->num_ftrace_callsites); | |
8c189ea6 SRRH |
4313 | return 0; |
4314 | } | |
4315 | ||
4316 | static int ftrace_module_notify_exit(struct notifier_block *self, | |
4317 | unsigned long val, void *data) | |
4318 | { | |
4319 | struct module *mod = data; | |
4320 | ||
4321 | if (val == MODULE_STATE_GOING) | |
e7247a15 | 4322 | ftrace_release_mod(mod); |
93eb677d SR |
4323 | |
4324 | return 0; | |
4325 | } | |
4326 | #else | |
8c189ea6 SRRH |
4327 | static int ftrace_module_notify_enter(struct notifier_block *self, |
4328 | unsigned long val, void *data) | |
4329 | { | |
4330 | return 0; | |
4331 | } | |
4332 | static int ftrace_module_notify_exit(struct notifier_block *self, | |
4333 | unsigned long val, void *data) | |
93eb677d SR |
4334 | { |
4335 | return 0; | |
4336 | } | |
4337 | #endif /* CONFIG_MODULES */ | |
4338 | ||
8c189ea6 SRRH |
4339 | struct notifier_block ftrace_module_enter_nb = { |
4340 | .notifier_call = ftrace_module_notify_enter, | |
c1bf08ac | 4341 | .priority = INT_MAX, /* Run before anything that can use kprobes */ |
93eb677d SR |
4342 | }; |
4343 | ||
8c189ea6 SRRH |
4344 | struct notifier_block ftrace_module_exit_nb = { |
4345 | .notifier_call = ftrace_module_notify_exit, | |
4346 | .priority = INT_MIN, /* Run after anything that can remove kprobes */ | |
4347 | }; | |
4348 | ||
68bf21aa SR |
4349 | extern unsigned long __start_mcount_loc[]; |
4350 | extern unsigned long __stop_mcount_loc[]; | |
4351 | ||
4352 | void __init ftrace_init(void) | |
4353 | { | |
4354 | unsigned long count, addr, flags; | |
4355 | int ret; | |
4356 | ||
4357 | /* Keep the ftrace pointer to the stub */ | |
4358 | addr = (unsigned long)ftrace_stub; | |
4359 | ||
4360 | local_irq_save(flags); | |
4361 | ftrace_dyn_arch_init(&addr); | |
4362 | local_irq_restore(flags); | |
4363 | ||
4364 | /* ftrace_dyn_arch_init places the return code in addr */ | |
4365 | if (addr) | |
4366 | goto failed; | |
4367 | ||
4368 | count = __stop_mcount_loc - __start_mcount_loc; | |
4369 | ||
4370 | ret = ftrace_dyn_table_alloc(count); | |
4371 | if (ret) | |
4372 | goto failed; | |
4373 | ||
4374 | last_ftrace_enabled = ftrace_enabled = 1; | |
4375 | ||
5cb084bb | 4376 | ret = ftrace_process_locs(NULL, |
31e88909 | 4377 | __start_mcount_loc, |
68bf21aa SR |
4378 | __stop_mcount_loc); |
4379 | ||
8c189ea6 SRRH |
4380 | ret = register_module_notifier(&ftrace_module_enter_nb); |
4381 | if (ret) | |
4382 | pr_warning("Failed to register trace ftrace module enter notifier\n"); | |
4383 | ||
4384 | ret = register_module_notifier(&ftrace_module_exit_nb); | |
24ed0c4b | 4385 | if (ret) |
8c189ea6 | 4386 | pr_warning("Failed to register trace ftrace module exit notifier\n"); |
93eb677d | 4387 | |
2af15d6a SR |
4388 | set_ftrace_early_filters(); |
4389 | ||
68bf21aa SR |
4390 | return; |
4391 | failed: | |
4392 | ftrace_disabled = 1; | |
4393 | } | |
68bf21aa | 4394 | |
3d083395 | 4395 | #else |
0b6e4d56 | 4396 | |
2b499381 | 4397 | static struct ftrace_ops global_ops = { |
bd69c30b | 4398 | .func = ftrace_stub, |
f04f24fb MH |
4399 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, |
4400 | INIT_REGEX_LOCK(global_ops) | |
bd69c30b SR |
4401 | }; |
4402 | ||
0b6e4d56 FW |
4403 | static int __init ftrace_nodyn_init(void) |
4404 | { | |
4405 | ftrace_enabled = 1; | |
4406 | return 0; | |
4407 | } | |
6f415672 | 4408 | core_initcall(ftrace_nodyn_init); |
0b6e4d56 | 4409 | |
df4fc315 SR |
4410 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
4411 | static inline void ftrace_startup_enable(int command) { } | |
5a45cfe1 | 4412 | /* Keep as macros so we do not need to define the commands */ |
8a56d776 SRRH |
4413 | # define ftrace_startup(ops, command) \ |
4414 | ({ \ | |
4415 | int ___ret = __register_ftrace_function(ops); \ | |
4416 | if (!___ret) \ | |
4417 | (ops)->flags |= FTRACE_OPS_FL_ENABLED; \ | |
4418 | ___ret; \ | |
3b6cfdb1 | 4419 | }) |
8a56d776 SRRH |
4420 | # define ftrace_shutdown(ops, command) __unregister_ftrace_function(ops) |
4421 | ||
c7aafc54 IM |
4422 | # define ftrace_startup_sysctl() do { } while (0) |
4423 | # define ftrace_shutdown_sysctl() do { } while (0) | |
b848914c SR |
4424 | |
4425 | static inline int | |
195a8afc | 4426 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
b848914c SR |
4427 | { |
4428 | return 1; | |
4429 | } | |
4430 | ||
3d083395 SR |
4431 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
4432 | ||
e248491a | 4433 | static void |
2f5f6ad9 | 4434 | ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 4435 | struct ftrace_ops *op, struct pt_regs *regs) |
e248491a | 4436 | { |
e248491a JO |
4437 | if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT))) |
4438 | return; | |
4439 | ||
4440 | /* | |
4441 | * Some of the ops may be dynamically allocated, | |
4442 | * they must be freed after a synchronize_sched(). | |
4443 | */ | |
4444 | preempt_disable_notrace(); | |
4445 | trace_recursion_set(TRACE_CONTROL_BIT); | |
b5aa3a47 SRRH |
4446 | |
4447 | /* | |
4448 | * Control funcs (perf) uses RCU. Only trace if | |
4449 | * RCU is currently active. | |
4450 | */ | |
4451 | if (!rcu_is_watching()) | |
4452 | goto out; | |
4453 | ||
0a016409 | 4454 | do_for_each_ftrace_op(op, ftrace_control_list) { |
395b97a3 SRRH |
4455 | if (!(op->flags & FTRACE_OPS_FL_STUB) && |
4456 | !ftrace_function_local_disabled(op) && | |
195a8afc | 4457 | ftrace_ops_test(op, ip, regs)) |
a1e2e31d | 4458 | op->func(ip, parent_ip, op, regs); |
0a016409 | 4459 | } while_for_each_ftrace_op(op); |
b5aa3a47 | 4460 | out: |
e248491a JO |
4461 | trace_recursion_clear(TRACE_CONTROL_BIT); |
4462 | preempt_enable_notrace(); | |
4463 | } | |
4464 | ||
4465 | static struct ftrace_ops control_ops = { | |
f04f24fb MH |
4466 | .func = ftrace_ops_control_func, |
4467 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, | |
4468 | INIT_REGEX_LOCK(control_ops) | |
e248491a JO |
4469 | }; |
4470 | ||
2f5f6ad9 SR |
4471 | static inline void |
4472 | __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 4473 | struct ftrace_ops *ignored, struct pt_regs *regs) |
b848914c | 4474 | { |
cdbe61bf | 4475 | struct ftrace_ops *op; |
edc15caf | 4476 | int bit; |
b848914c | 4477 | |
ccf3672d SR |
4478 | if (function_trace_stop) |
4479 | return; | |
4480 | ||
edc15caf SR |
4481 | bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX); |
4482 | if (bit < 0) | |
4483 | return; | |
b1cff0ad | 4484 | |
cdbe61bf SR |
4485 | /* |
4486 | * Some of the ops may be dynamically allocated, | |
4487 | * they must be freed after a synchronize_sched(). | |
4488 | */ | |
4489 | preempt_disable_notrace(); | |
0a016409 | 4490 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
195a8afc | 4491 | if (ftrace_ops_test(op, ip, regs)) |
a1e2e31d | 4492 | op->func(ip, parent_ip, op, regs); |
0a016409 | 4493 | } while_for_each_ftrace_op(op); |
cdbe61bf | 4494 | preempt_enable_notrace(); |
edc15caf | 4495 | trace_clear_recursion(bit); |
b848914c SR |
4496 | } |
4497 | ||
2f5f6ad9 SR |
4498 | /* |
4499 | * Some archs only support passing ip and parent_ip. Even though | |
4500 | * the list function ignores the op parameter, we do not want any | |
4501 | * C side effects, where a function is called without the caller | |
4502 | * sending a third parameter. | |
a1e2e31d SR |
4503 | * Archs are to support both the regs and ftrace_ops at the same time. |
4504 | * If they support ftrace_ops, it is assumed they support regs. | |
4505 | * If call backs want to use regs, they must either check for regs | |
06aeaaea MH |
4506 | * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS. |
4507 | * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved. | |
a1e2e31d SR |
4508 | * An architecture can pass partial regs with ftrace_ops and still |
4509 | * set the ARCH_SUPPORT_FTARCE_OPS. | |
2f5f6ad9 SR |
4510 | */ |
4511 | #if ARCH_SUPPORTS_FTRACE_OPS | |
4512 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 4513 | struct ftrace_ops *op, struct pt_regs *regs) |
2f5f6ad9 | 4514 | { |
a1e2e31d | 4515 | __ftrace_ops_list_func(ip, parent_ip, NULL, regs); |
2f5f6ad9 SR |
4516 | } |
4517 | #else | |
4518 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip) | |
4519 | { | |
a1e2e31d | 4520 | __ftrace_ops_list_func(ip, parent_ip, NULL, NULL); |
2f5f6ad9 SR |
4521 | } |
4522 | #endif | |
4523 | ||
e32d8956 | 4524 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
4525 | { |
4526 | struct task_struct *p; | |
e32d8956 | 4527 | int cpu; |
978f3a45 | 4528 | |
e32d8956 SR |
4529 | get_online_cpus(); |
4530 | for_each_online_cpu(cpu) { | |
4531 | p = idle_task(cpu); | |
978f3a45 | 4532 | clear_tsk_trace_trace(p); |
e32d8956 SR |
4533 | } |
4534 | put_online_cpus(); | |
4535 | } | |
978f3a45 | 4536 | |
e32d8956 SR |
4537 | static void set_ftrace_swapper(void) |
4538 | { | |
4539 | struct task_struct *p; | |
4540 | int cpu; | |
4541 | ||
4542 | get_online_cpus(); | |
4543 | for_each_online_cpu(cpu) { | |
4544 | p = idle_task(cpu); | |
4545 | set_tsk_trace_trace(p); | |
4546 | } | |
4547 | put_online_cpus(); | |
978f3a45 SR |
4548 | } |
4549 | ||
e32d8956 SR |
4550 | static void clear_ftrace_pid(struct pid *pid) |
4551 | { | |
4552 | struct task_struct *p; | |
4553 | ||
229c4ef8 | 4554 | rcu_read_lock(); |
e32d8956 SR |
4555 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
4556 | clear_tsk_trace_trace(p); | |
4557 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
4558 | rcu_read_unlock(); |
4559 | ||
e32d8956 SR |
4560 | put_pid(pid); |
4561 | } | |
4562 | ||
4563 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
4564 | { |
4565 | struct task_struct *p; | |
4566 | ||
229c4ef8 | 4567 | rcu_read_lock(); |
978f3a45 SR |
4568 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
4569 | set_tsk_trace_trace(p); | |
4570 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 4571 | rcu_read_unlock(); |
978f3a45 SR |
4572 | } |
4573 | ||
756d17ee | 4574 | static void clear_ftrace_pid_task(struct pid *pid) |
e32d8956 | 4575 | { |
756d17ee | 4576 | if (pid == ftrace_swapper_pid) |
e32d8956 SR |
4577 | clear_ftrace_swapper(); |
4578 | else | |
756d17ee | 4579 | clear_ftrace_pid(pid); |
e32d8956 SR |
4580 | } |
4581 | ||
4582 | static void set_ftrace_pid_task(struct pid *pid) | |
4583 | { | |
4584 | if (pid == ftrace_swapper_pid) | |
4585 | set_ftrace_swapper(); | |
4586 | else | |
4587 | set_ftrace_pid(pid); | |
4588 | } | |
4589 | ||
756d17ee | 4590 | static int ftrace_pid_add(int p) |
df4fc315 | 4591 | { |
978f3a45 | 4592 | struct pid *pid; |
756d17ee | 4593 | struct ftrace_pid *fpid; |
4594 | int ret = -EINVAL; | |
df4fc315 | 4595 | |
756d17ee | 4596 | mutex_lock(&ftrace_lock); |
df4fc315 | 4597 | |
756d17ee | 4598 | if (!p) |
4599 | pid = ftrace_swapper_pid; | |
4600 | else | |
4601 | pid = find_get_pid(p); | |
df4fc315 | 4602 | |
756d17ee | 4603 | if (!pid) |
4604 | goto out; | |
df4fc315 | 4605 | |
756d17ee | 4606 | ret = 0; |
df4fc315 | 4607 | |
756d17ee | 4608 | list_for_each_entry(fpid, &ftrace_pids, list) |
4609 | if (fpid->pid == pid) | |
4610 | goto out_put; | |
978f3a45 | 4611 | |
756d17ee | 4612 | ret = -ENOMEM; |
df4fc315 | 4613 | |
756d17ee | 4614 | fpid = kmalloc(sizeof(*fpid), GFP_KERNEL); |
4615 | if (!fpid) | |
4616 | goto out_put; | |
df4fc315 | 4617 | |
756d17ee | 4618 | list_add(&fpid->list, &ftrace_pids); |
4619 | fpid->pid = pid; | |
0ef8cde5 | 4620 | |
756d17ee | 4621 | set_ftrace_pid_task(pid); |
978f3a45 | 4622 | |
756d17ee | 4623 | ftrace_update_pid_func(); |
4624 | ftrace_startup_enable(0); | |
4625 | ||
4626 | mutex_unlock(&ftrace_lock); | |
4627 | return 0; | |
4628 | ||
4629 | out_put: | |
4630 | if (pid != ftrace_swapper_pid) | |
4631 | put_pid(pid); | |
978f3a45 | 4632 | |
756d17ee | 4633 | out: |
4634 | mutex_unlock(&ftrace_lock); | |
4635 | return ret; | |
4636 | } | |
4637 | ||
4638 | static void ftrace_pid_reset(void) | |
4639 | { | |
4640 | struct ftrace_pid *fpid, *safe; | |
978f3a45 | 4641 | |
756d17ee | 4642 | mutex_lock(&ftrace_lock); |
4643 | list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) { | |
4644 | struct pid *pid = fpid->pid; | |
4645 | ||
4646 | clear_ftrace_pid_task(pid); | |
4647 | ||
4648 | list_del(&fpid->list); | |
4649 | kfree(fpid); | |
df4fc315 SR |
4650 | } |
4651 | ||
df4fc315 SR |
4652 | ftrace_update_pid_func(); |
4653 | ftrace_startup_enable(0); | |
4654 | ||
e6ea44e9 | 4655 | mutex_unlock(&ftrace_lock); |
756d17ee | 4656 | } |
df4fc315 | 4657 | |
756d17ee | 4658 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
4659 | { | |
4660 | mutex_lock(&ftrace_lock); | |
4661 | ||
4662 | if (list_empty(&ftrace_pids) && (!*pos)) | |
4663 | return (void *) 1; | |
4664 | ||
4665 | return seq_list_start(&ftrace_pids, *pos); | |
4666 | } | |
4667 | ||
4668 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
4669 | { | |
4670 | if (v == (void *)1) | |
4671 | return NULL; | |
4672 | ||
4673 | return seq_list_next(v, &ftrace_pids, pos); | |
4674 | } | |
4675 | ||
4676 | static void fpid_stop(struct seq_file *m, void *p) | |
4677 | { | |
4678 | mutex_unlock(&ftrace_lock); | |
4679 | } | |
4680 | ||
4681 | static int fpid_show(struct seq_file *m, void *v) | |
4682 | { | |
4683 | const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list); | |
4684 | ||
4685 | if (v == (void *)1) { | |
4686 | seq_printf(m, "no pid\n"); | |
4687 | return 0; | |
4688 | } | |
4689 | ||
4690 | if (fpid->pid == ftrace_swapper_pid) | |
4691 | seq_printf(m, "swapper tasks\n"); | |
4692 | else | |
4693 | seq_printf(m, "%u\n", pid_vnr(fpid->pid)); | |
4694 | ||
4695 | return 0; | |
4696 | } | |
4697 | ||
4698 | static const struct seq_operations ftrace_pid_sops = { | |
4699 | .start = fpid_start, | |
4700 | .next = fpid_next, | |
4701 | .stop = fpid_stop, | |
4702 | .show = fpid_show, | |
4703 | }; | |
4704 | ||
4705 | static int | |
4706 | ftrace_pid_open(struct inode *inode, struct file *file) | |
4707 | { | |
4708 | int ret = 0; | |
4709 | ||
4710 | if ((file->f_mode & FMODE_WRITE) && | |
4711 | (file->f_flags & O_TRUNC)) | |
4712 | ftrace_pid_reset(); | |
4713 | ||
4714 | if (file->f_mode & FMODE_READ) | |
4715 | ret = seq_open(file, &ftrace_pid_sops); | |
4716 | ||
4717 | return ret; | |
4718 | } | |
4719 | ||
df4fc315 SR |
4720 | static ssize_t |
4721 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
4722 | size_t cnt, loff_t *ppos) | |
4723 | { | |
457dc928 | 4724 | char buf[64], *tmp; |
df4fc315 SR |
4725 | long val; |
4726 | int ret; | |
4727 | ||
4728 | if (cnt >= sizeof(buf)) | |
4729 | return -EINVAL; | |
4730 | ||
4731 | if (copy_from_user(&buf, ubuf, cnt)) | |
4732 | return -EFAULT; | |
4733 | ||
4734 | buf[cnt] = 0; | |
4735 | ||
756d17ee | 4736 | /* |
4737 | * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid" | |
4738 | * to clean the filter quietly. | |
4739 | */ | |
457dc928 IM |
4740 | tmp = strstrip(buf); |
4741 | if (strlen(tmp) == 0) | |
756d17ee | 4742 | return 1; |
4743 | ||
bcd83ea6 | 4744 | ret = kstrtol(tmp, 10, &val); |
df4fc315 SR |
4745 | if (ret < 0) |
4746 | return ret; | |
4747 | ||
756d17ee | 4748 | ret = ftrace_pid_add(val); |
df4fc315 | 4749 | |
756d17ee | 4750 | return ret ? ret : cnt; |
4751 | } | |
df4fc315 | 4752 | |
756d17ee | 4753 | static int |
4754 | ftrace_pid_release(struct inode *inode, struct file *file) | |
4755 | { | |
4756 | if (file->f_mode & FMODE_READ) | |
4757 | seq_release(inode, file); | |
df4fc315 | 4758 | |
756d17ee | 4759 | return 0; |
df4fc315 SR |
4760 | } |
4761 | ||
5e2336a0 | 4762 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 4763 | .open = ftrace_pid_open, |
4764 | .write = ftrace_pid_write, | |
4765 | .read = seq_read, | |
098c879e | 4766 | .llseek = tracing_lseek, |
756d17ee | 4767 | .release = ftrace_pid_release, |
df4fc315 SR |
4768 | }; |
4769 | ||
4770 | static __init int ftrace_init_debugfs(void) | |
4771 | { | |
4772 | struct dentry *d_tracer; | |
df4fc315 SR |
4773 | |
4774 | d_tracer = tracing_init_dentry(); | |
4775 | if (!d_tracer) | |
4776 | return 0; | |
4777 | ||
4778 | ftrace_init_dyn_debugfs(d_tracer); | |
4779 | ||
5452af66 FW |
4780 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
4781 | NULL, &ftrace_pid_fops); | |
493762fc SR |
4782 | |
4783 | ftrace_profile_debugfs(d_tracer); | |
4784 | ||
df4fc315 SR |
4785 | return 0; |
4786 | } | |
df4fc315 SR |
4787 | fs_initcall(ftrace_init_debugfs); |
4788 | ||
a2bb6a3d | 4789 | /** |
81adbdc0 | 4790 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
4791 | * |
4792 | * This function should be used by panic code. It stops ftrace | |
4793 | * but in a not so nice way. If you need to simply kill ftrace | |
4794 | * from a non-atomic section, use ftrace_kill. | |
4795 | */ | |
81adbdc0 | 4796 | void ftrace_kill(void) |
a2bb6a3d SR |
4797 | { |
4798 | ftrace_disabled = 1; | |
4799 | ftrace_enabled = 0; | |
a2bb6a3d SR |
4800 | clear_ftrace_function(); |
4801 | } | |
4802 | ||
e0a413f6 SR |
4803 | /** |
4804 | * Test if ftrace is dead or not. | |
4805 | */ | |
4806 | int ftrace_is_dead(void) | |
4807 | { | |
4808 | return ftrace_disabled; | |
4809 | } | |
4810 | ||
16444a8a | 4811 | /** |
3d083395 SR |
4812 | * register_ftrace_function - register a function for profiling |
4813 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 4814 | * |
3d083395 SR |
4815 | * Register a function to be called by all functions in the |
4816 | * kernel. | |
4817 | * | |
4818 | * Note: @ops->func and all the functions it calls must be labeled | |
4819 | * with "notrace", otherwise it will go into a | |
4820 | * recursive loop. | |
16444a8a | 4821 | */ |
3d083395 | 4822 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 4823 | { |
45a4a237 | 4824 | int ret = -1; |
4eebcc81 | 4825 | |
f04f24fb MH |
4826 | ftrace_ops_init(ops); |
4827 | ||
e6ea44e9 | 4828 | mutex_lock(&ftrace_lock); |
e7d3737e | 4829 | |
8a56d776 | 4830 | ret = ftrace_startup(ops, 0); |
b848914c | 4831 | |
e6ea44e9 | 4832 | mutex_unlock(&ftrace_lock); |
8d240dd8 | 4833 | |
b0fc494f | 4834 | return ret; |
3d083395 | 4835 | } |
cdbe61bf | 4836 | EXPORT_SYMBOL_GPL(register_ftrace_function); |
3d083395 SR |
4837 | |
4838 | /** | |
32632920 | 4839 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
4840 | * @ops - ops structure that holds the function to unregister |
4841 | * | |
4842 | * Unregister a function that was added to be called by ftrace profiling. | |
4843 | */ | |
4844 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
4845 | { | |
4846 | int ret; | |
4847 | ||
e6ea44e9 | 4848 | mutex_lock(&ftrace_lock); |
8a56d776 | 4849 | ret = ftrace_shutdown(ops, 0); |
e6ea44e9 | 4850 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
4851 | |
4852 | return ret; | |
4853 | } | |
cdbe61bf | 4854 | EXPORT_SYMBOL_GPL(unregister_ftrace_function); |
b0fc494f | 4855 | |
e309b41d | 4856 | int |
b0fc494f | 4857 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
8d65af78 | 4858 | void __user *buffer, size_t *lenp, |
b0fc494f SR |
4859 | loff_t *ppos) |
4860 | { | |
45a4a237 | 4861 | int ret = -ENODEV; |
4eebcc81 | 4862 | |
e6ea44e9 | 4863 | mutex_lock(&ftrace_lock); |
b0fc494f | 4864 | |
45a4a237 SR |
4865 | if (unlikely(ftrace_disabled)) |
4866 | goto out; | |
4867 | ||
4868 | ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
b0fc494f | 4869 | |
a32c7765 | 4870 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
4871 | goto out; |
4872 | ||
a32c7765 | 4873 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f SR |
4874 | |
4875 | if (ftrace_enabled) { | |
4876 | ||
4877 | ftrace_startup_sysctl(); | |
4878 | ||
4879 | /* we are starting ftrace again */ | |
5000c418 JK |
4880 | if (ftrace_ops_list != &ftrace_list_end) |
4881 | update_ftrace_function(); | |
b0fc494f SR |
4882 | |
4883 | } else { | |
4884 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
4885 | ftrace_trace_function = ftrace_stub; | |
4886 | ||
4887 | ftrace_shutdown_sysctl(); | |
4888 | } | |
4889 | ||
4890 | out: | |
e6ea44e9 | 4891 | mutex_unlock(&ftrace_lock); |
3d083395 | 4892 | return ret; |
16444a8a | 4893 | } |
f17845e5 | 4894 | |
fb52607a | 4895 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 4896 | |
597af815 | 4897 | static int ftrace_graph_active; |
4a2b8dda | 4898 | static struct notifier_block ftrace_suspend_notifier; |
e7d3737e | 4899 | |
e49dc19c SR |
4900 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
4901 | { | |
4902 | return 0; | |
4903 | } | |
4904 | ||
287b6e68 FW |
4905 | /* The callbacks that hook a function */ |
4906 | trace_func_graph_ret_t ftrace_graph_return = | |
4907 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 4908 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
4909 | |
4910 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
4911 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
4912 | { | |
4913 | int i; | |
4914 | int ret = 0; | |
4915 | unsigned long flags; | |
4916 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
4917 | struct task_struct *g, *t; | |
4918 | ||
4919 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
4920 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
4921 | * sizeof(struct ftrace_ret_stack), | |
4922 | GFP_KERNEL); | |
4923 | if (!ret_stack_list[i]) { | |
4924 | start = 0; | |
4925 | end = i; | |
4926 | ret = -ENOMEM; | |
4927 | goto free; | |
4928 | } | |
4929 | } | |
4930 | ||
4931 | read_lock_irqsave(&tasklist_lock, flags); | |
4932 | do_each_thread(g, t) { | |
4933 | if (start == end) { | |
4934 | ret = -EAGAIN; | |
4935 | goto unlock; | |
4936 | } | |
4937 | ||
4938 | if (t->ret_stack == NULL) { | |
380c4b14 | 4939 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 4940 | atomic_set(&t->trace_overrun, 0); |
26c01624 SR |
4941 | t->curr_ret_stack = -1; |
4942 | /* Make sure the tasks see the -1 first: */ | |
4943 | smp_wmb(); | |
4944 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
4945 | } |
4946 | } while_each_thread(g, t); | |
4947 | ||
4948 | unlock: | |
4949 | read_unlock_irqrestore(&tasklist_lock, flags); | |
4950 | free: | |
4951 | for (i = start; i < end; i++) | |
4952 | kfree(ret_stack_list[i]); | |
4953 | return ret; | |
4954 | } | |
4955 | ||
8aef2d28 | 4956 | static void |
38516ab5 SR |
4957 | ftrace_graph_probe_sched_switch(void *ignore, |
4958 | struct task_struct *prev, struct task_struct *next) | |
8aef2d28 SR |
4959 | { |
4960 | unsigned long long timestamp; | |
4961 | int index; | |
4962 | ||
be6f164a SR |
4963 | /* |
4964 | * Does the user want to count the time a function was asleep. | |
4965 | * If so, do not update the time stamps. | |
4966 | */ | |
4967 | if (trace_flags & TRACE_ITER_SLEEP_TIME) | |
4968 | return; | |
4969 | ||
8aef2d28 SR |
4970 | timestamp = trace_clock_local(); |
4971 | ||
4972 | prev->ftrace_timestamp = timestamp; | |
4973 | ||
4974 | /* only process tasks that we timestamped */ | |
4975 | if (!next->ftrace_timestamp) | |
4976 | return; | |
4977 | ||
4978 | /* | |
4979 | * Update all the counters in next to make up for the | |
4980 | * time next was sleeping. | |
4981 | */ | |
4982 | timestamp -= next->ftrace_timestamp; | |
4983 | ||
4984 | for (index = next->curr_ret_stack; index >= 0; index--) | |
4985 | next->ret_stack[index].calltime += timestamp; | |
4986 | } | |
4987 | ||
f201ae23 | 4988 | /* Allocate a return stack for each task */ |
fb52607a | 4989 | static int start_graph_tracing(void) |
f201ae23 FW |
4990 | { |
4991 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 4992 | int ret, cpu; |
f201ae23 FW |
4993 | |
4994 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
4995 | sizeof(struct ftrace_ret_stack *), | |
4996 | GFP_KERNEL); | |
4997 | ||
4998 | if (!ret_stack_list) | |
4999 | return -ENOMEM; | |
5000 | ||
5b058bcd | 5001 | /* The cpu_boot init_task->ret_stack will never be freed */ |
179c498a SR |
5002 | for_each_online_cpu(cpu) { |
5003 | if (!idle_task(cpu)->ret_stack) | |
868baf07 | 5004 | ftrace_graph_init_idle_task(idle_task(cpu), cpu); |
179c498a | 5005 | } |
5b058bcd | 5006 | |
f201ae23 FW |
5007 | do { |
5008 | ret = alloc_retstack_tasklist(ret_stack_list); | |
5009 | } while (ret == -EAGAIN); | |
5010 | ||
8aef2d28 | 5011 | if (!ret) { |
38516ab5 | 5012 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
8aef2d28 SR |
5013 | if (ret) |
5014 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
5015 | " probe to kernel_sched_switch\n"); | |
5016 | } | |
5017 | ||
f201ae23 FW |
5018 | kfree(ret_stack_list); |
5019 | return ret; | |
5020 | } | |
5021 | ||
4a2b8dda FW |
5022 | /* |
5023 | * Hibernation protection. | |
5024 | * The state of the current task is too much unstable during | |
5025 | * suspend/restore to disk. We want to protect against that. | |
5026 | */ | |
5027 | static int | |
5028 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
5029 | void *unused) | |
5030 | { | |
5031 | switch (state) { | |
5032 | case PM_HIBERNATION_PREPARE: | |
5033 | pause_graph_tracing(); | |
5034 | break; | |
5035 | ||
5036 | case PM_POST_HIBERNATION: | |
5037 | unpause_graph_tracing(); | |
5038 | break; | |
5039 | } | |
5040 | return NOTIFY_DONE; | |
5041 | } | |
5042 | ||
8a56d776 SRRH |
5043 | /* Just a place holder for function graph */ |
5044 | static struct ftrace_ops fgraph_ops __read_mostly = { | |
5045 | .func = ftrace_stub, | |
5046 | .flags = FTRACE_OPS_FL_STUB | FTRACE_OPS_FL_GLOBAL | | |
5047 | FTRACE_OPS_FL_RECURSION_SAFE, | |
5048 | }; | |
5049 | ||
287b6e68 FW |
5050 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
5051 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 5052 | { |
e7d3737e FW |
5053 | int ret = 0; |
5054 | ||
e6ea44e9 | 5055 | mutex_lock(&ftrace_lock); |
e7d3737e | 5056 | |
05ce5818 | 5057 | /* we currently allow only one tracer registered at a time */ |
597af815 | 5058 | if (ftrace_graph_active) { |
05ce5818 SR |
5059 | ret = -EBUSY; |
5060 | goto out; | |
5061 | } | |
5062 | ||
4a2b8dda FW |
5063 | ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; |
5064 | register_pm_notifier(&ftrace_suspend_notifier); | |
5065 | ||
597af815 | 5066 | ftrace_graph_active++; |
fb52607a | 5067 | ret = start_graph_tracing(); |
f201ae23 | 5068 | if (ret) { |
597af815 | 5069 | ftrace_graph_active--; |
f201ae23 FW |
5070 | goto out; |
5071 | } | |
e53a6319 | 5072 | |
287b6e68 FW |
5073 | ftrace_graph_return = retfunc; |
5074 | ftrace_graph_entry = entryfunc; | |
e53a6319 | 5075 | |
8a56d776 | 5076 | ret = ftrace_startup(&fgraph_ops, FTRACE_START_FUNC_RET); |
e7d3737e FW |
5077 | |
5078 | out: | |
e6ea44e9 | 5079 | mutex_unlock(&ftrace_lock); |
e7d3737e | 5080 | return ret; |
15e6cb36 FW |
5081 | } |
5082 | ||
fb52607a | 5083 | void unregister_ftrace_graph(void) |
15e6cb36 | 5084 | { |
e6ea44e9 | 5085 | mutex_lock(&ftrace_lock); |
e7d3737e | 5086 | |
597af815 | 5087 | if (unlikely(!ftrace_graph_active)) |
2aad1b76 SR |
5088 | goto out; |
5089 | ||
597af815 | 5090 | ftrace_graph_active--; |
287b6e68 | 5091 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 5092 | ftrace_graph_entry = ftrace_graph_entry_stub; |
8a56d776 | 5093 | ftrace_shutdown(&fgraph_ops, FTRACE_STOP_FUNC_RET); |
4a2b8dda | 5094 | unregister_pm_notifier(&ftrace_suspend_notifier); |
38516ab5 | 5095 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
e7d3737e | 5096 | |
2aad1b76 | 5097 | out: |
e6ea44e9 | 5098 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 5099 | } |
f201ae23 | 5100 | |
868baf07 SR |
5101 | static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack); |
5102 | ||
5103 | static void | |
5104 | graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack) | |
5105 | { | |
5106 | atomic_set(&t->tracing_graph_pause, 0); | |
5107 | atomic_set(&t->trace_overrun, 0); | |
5108 | t->ftrace_timestamp = 0; | |
25985edc | 5109 | /* make curr_ret_stack visible before we add the ret_stack */ |
868baf07 SR |
5110 | smp_wmb(); |
5111 | t->ret_stack = ret_stack; | |
5112 | } | |
5113 | ||
5114 | /* | |
5115 | * Allocate a return stack for the idle task. May be the first | |
5116 | * time through, or it may be done by CPU hotplug online. | |
5117 | */ | |
5118 | void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) | |
5119 | { | |
5120 | t->curr_ret_stack = -1; | |
5121 | /* | |
5122 | * The idle task has no parent, it either has its own | |
5123 | * stack or no stack at all. | |
5124 | */ | |
5125 | if (t->ret_stack) | |
5126 | WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu)); | |
5127 | ||
5128 | if (ftrace_graph_active) { | |
5129 | struct ftrace_ret_stack *ret_stack; | |
5130 | ||
5131 | ret_stack = per_cpu(idle_ret_stack, cpu); | |
5132 | if (!ret_stack) { | |
5133 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
5134 | * sizeof(struct ftrace_ret_stack), | |
5135 | GFP_KERNEL); | |
5136 | if (!ret_stack) | |
5137 | return; | |
5138 | per_cpu(idle_ret_stack, cpu) = ret_stack; | |
5139 | } | |
5140 | graph_init_task(t, ret_stack); | |
5141 | } | |
5142 | } | |
5143 | ||
f201ae23 | 5144 | /* Allocate a return stack for newly created task */ |
fb52607a | 5145 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 5146 | { |
84047e36 SR |
5147 | /* Make sure we do not use the parent ret_stack */ |
5148 | t->ret_stack = NULL; | |
ea14eb71 | 5149 | t->curr_ret_stack = -1; |
84047e36 | 5150 | |
597af815 | 5151 | if (ftrace_graph_active) { |
82310a32 SR |
5152 | struct ftrace_ret_stack *ret_stack; |
5153 | ||
5154 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
f201ae23 FW |
5155 | * sizeof(struct ftrace_ret_stack), |
5156 | GFP_KERNEL); | |
82310a32 | 5157 | if (!ret_stack) |
f201ae23 | 5158 | return; |
868baf07 | 5159 | graph_init_task(t, ret_stack); |
84047e36 | 5160 | } |
f201ae23 FW |
5161 | } |
5162 | ||
fb52607a | 5163 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 5164 | { |
eae849ca FW |
5165 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
5166 | ||
f201ae23 | 5167 | t->ret_stack = NULL; |
eae849ca FW |
5168 | /* NULL must become visible to IRQs before we free it: */ |
5169 | barrier(); | |
5170 | ||
5171 | kfree(ret_stack); | |
f201ae23 | 5172 | } |
14a866c5 SR |
5173 | |
5174 | void ftrace_graph_stop(void) | |
5175 | { | |
5176 | ftrace_stop(); | |
5177 | } | |
15e6cb36 | 5178 | #endif |