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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; | |
60a7ecf4 | 88 | |
756d17ee | 89 | /* List for set_ftrace_pid's pids. */ |
90 | LIST_HEAD(ftrace_pids); | |
91 | struct ftrace_pid { | |
92 | struct list_head list; | |
93 | struct pid *pid; | |
94 | }; | |
95 | ||
4eebcc81 SR |
96 | /* |
97 | * ftrace_disabled is set when an anomaly is discovered. | |
98 | * ftrace_disabled is much stronger than ftrace_enabled. | |
99 | */ | |
100 | static int ftrace_disabled __read_mostly; | |
101 | ||
52baf119 | 102 | static DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 103 | |
b848914c | 104 | static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end; |
e248491a | 105 | static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end; |
b848914c | 106 | static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end; |
16444a8a | 107 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
df4fc315 | 108 | ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; |
2b499381 | 109 | static struct ftrace_ops global_ops; |
e248491a | 110 | static struct ftrace_ops control_ops; |
16444a8a | 111 | |
2f5f6ad9 SR |
112 | #if ARCH_SUPPORTS_FTRACE_OPS |
113 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 114 | struct ftrace_ops *op, struct pt_regs *regs); |
2f5f6ad9 SR |
115 | #else |
116 | /* See comment below, where ftrace_ops_list_func is defined */ | |
117 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip); | |
118 | #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops) | |
119 | #endif | |
b848914c | 120 | |
0a016409 SR |
121 | /* |
122 | * Traverse the ftrace_global_list, invoking all entries. The reason that we | |
1bb539ca | 123 | * can use rcu_dereference_raw_notrace() is that elements removed from this list |
0a016409 | 124 | * are simply leaked, so there is no need to interact with a grace-period |
1bb539ca | 125 | * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle |
0a016409 SR |
126 | * concurrent insertions into the ftrace_global_list. |
127 | * | |
128 | * Silly Alpha and silly pointer-speculation compiler optimizations! | |
129 | */ | |
130 | #define do_for_each_ftrace_op(op, list) \ | |
1bb539ca | 131 | op = rcu_dereference_raw_notrace(list); \ |
0a016409 SR |
132 | do |
133 | ||
134 | /* | |
135 | * Optimized for just a single item in the list (as that is the normal case). | |
136 | */ | |
137 | #define while_for_each_ftrace_op(op) \ | |
1bb539ca | 138 | while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \ |
0a016409 SR |
139 | unlikely((op) != &ftrace_list_end)) |
140 | ||
f04f24fb MH |
141 | static inline void ftrace_ops_init(struct ftrace_ops *ops) |
142 | { | |
143 | #ifdef CONFIG_DYNAMIC_FTRACE | |
144 | if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) { | |
145 | mutex_init(&ops->regex_lock); | |
146 | ops->flags |= FTRACE_OPS_FL_INITIALIZED; | |
147 | } | |
148 | #endif | |
149 | } | |
150 | ||
ea701f11 SR |
151 | /** |
152 | * ftrace_nr_registered_ops - return number of ops registered | |
153 | * | |
154 | * Returns the number of ftrace_ops registered and tracing functions | |
155 | */ | |
156 | int ftrace_nr_registered_ops(void) | |
157 | { | |
158 | struct ftrace_ops *ops; | |
159 | int cnt = 0; | |
160 | ||
161 | mutex_lock(&ftrace_lock); | |
162 | ||
163 | for (ops = ftrace_ops_list; | |
164 | ops != &ftrace_list_end; ops = ops->next) | |
165 | cnt++; | |
166 | ||
167 | mutex_unlock(&ftrace_lock); | |
168 | ||
169 | return cnt; | |
170 | } | |
171 | ||
2f5f6ad9 SR |
172 | static void |
173 | ftrace_global_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 174 | struct ftrace_ops *op, struct pt_regs *regs) |
16444a8a | 175 | { |
c29f122c SR |
176 | int bit; |
177 | ||
edc15caf SR |
178 | bit = trace_test_and_set_recursion(TRACE_GLOBAL_START, TRACE_GLOBAL_MAX); |
179 | if (bit < 0) | |
b1cff0ad | 180 | return; |
16444a8a | 181 | |
0a016409 | 182 | do_for_each_ftrace_op(op, ftrace_global_list) { |
a1e2e31d | 183 | op->func(ip, parent_ip, op, regs); |
0a016409 | 184 | } while_for_each_ftrace_op(op); |
edc15caf SR |
185 | |
186 | trace_clear_recursion(bit); | |
16444a8a ACM |
187 | } |
188 | ||
2f5f6ad9 | 189 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 190 | struct ftrace_ops *op, struct pt_regs *regs) |
df4fc315 | 191 | { |
0ef8cde5 | 192 | if (!test_tsk_trace_trace(current)) |
df4fc315 SR |
193 | return; |
194 | ||
a1e2e31d | 195 | ftrace_pid_function(ip, parent_ip, op, regs); |
df4fc315 SR |
196 | } |
197 | ||
198 | static void set_ftrace_pid_function(ftrace_func_t func) | |
199 | { | |
200 | /* do not set ftrace_pid_function to itself! */ | |
201 | if (func != ftrace_pid_func) | |
202 | ftrace_pid_function = func; | |
203 | } | |
204 | ||
16444a8a | 205 | /** |
3d083395 | 206 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 207 | * |
3d083395 SR |
208 | * This NULLs the ftrace function and in essence stops |
209 | * tracing. There may be lag | |
16444a8a | 210 | */ |
3d083395 | 211 | void clear_ftrace_function(void) |
16444a8a | 212 | { |
3d083395 | 213 | ftrace_trace_function = ftrace_stub; |
df4fc315 | 214 | ftrace_pid_function = ftrace_stub; |
3d083395 SR |
215 | } |
216 | ||
e248491a JO |
217 | static void control_ops_disable_all(struct ftrace_ops *ops) |
218 | { | |
219 | int cpu; | |
220 | ||
221 | for_each_possible_cpu(cpu) | |
222 | *per_cpu_ptr(ops->disabled, cpu) = 1; | |
223 | } | |
224 | ||
225 | static int control_ops_alloc(struct ftrace_ops *ops) | |
226 | { | |
227 | int __percpu *disabled; | |
228 | ||
229 | disabled = alloc_percpu(int); | |
230 | if (!disabled) | |
231 | return -ENOMEM; | |
232 | ||
233 | ops->disabled = disabled; | |
234 | control_ops_disable_all(ops); | |
235 | return 0; | |
236 | } | |
237 | ||
238 | static void control_ops_free(struct ftrace_ops *ops) | |
239 | { | |
240 | free_percpu(ops->disabled); | |
241 | } | |
242 | ||
2b499381 | 243 | static void update_global_ops(void) |
491d0dcf SR |
244 | { |
245 | ftrace_func_t func; | |
246 | ||
247 | /* | |
248 | * If there's only one function registered, then call that | |
249 | * function directly. Otherwise, we need to iterate over the | |
250 | * registered callers. | |
251 | */ | |
b848914c | 252 | if (ftrace_global_list == &ftrace_list_end || |
63503794 | 253 | ftrace_global_list->next == &ftrace_list_end) { |
b848914c | 254 | func = ftrace_global_list->func; |
63503794 SR |
255 | /* |
256 | * As we are calling the function directly. | |
257 | * If it does not have recursion protection, | |
258 | * the function_trace_op needs to be updated | |
259 | * accordingly. | |
260 | */ | |
261 | if (ftrace_global_list->flags & FTRACE_OPS_FL_RECURSION_SAFE) | |
262 | global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE; | |
263 | else | |
264 | global_ops.flags &= ~FTRACE_OPS_FL_RECURSION_SAFE; | |
265 | } else { | |
b848914c | 266 | func = ftrace_global_list_func; |
63503794 SR |
267 | /* The list has its own recursion protection. */ |
268 | global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE; | |
269 | } | |
270 | ||
491d0dcf SR |
271 | |
272 | /* If we filter on pids, update to use the pid function */ | |
273 | if (!list_empty(&ftrace_pids)) { | |
274 | set_ftrace_pid_function(func); | |
275 | func = ftrace_pid_func; | |
276 | } | |
2b499381 SR |
277 | |
278 | global_ops.func = func; | |
279 | } | |
280 | ||
281 | static void update_ftrace_function(void) | |
282 | { | |
283 | ftrace_func_t func; | |
284 | ||
285 | update_global_ops(); | |
286 | ||
cdbe61bf SR |
287 | /* |
288 | * If we are at the end of the list and this ops is | |
4740974a SR |
289 | * recursion safe and not dynamic and the arch supports passing ops, |
290 | * then have the mcount trampoline call the function directly. | |
cdbe61bf | 291 | */ |
b848914c | 292 | if (ftrace_ops_list == &ftrace_list_end || |
cdbe61bf | 293 | (ftrace_ops_list->next == &ftrace_list_end && |
2f5f6ad9 | 294 | !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC) && |
4740974a | 295 | (ftrace_ops_list->flags & FTRACE_OPS_FL_RECURSION_SAFE) && |
ccf3672d | 296 | !FTRACE_FORCE_LIST_FUNC)) { |
2f5f6ad9 SR |
297 | /* Set the ftrace_ops that the arch callback uses */ |
298 | if (ftrace_ops_list == &global_ops) | |
299 | function_trace_op = ftrace_global_list; | |
300 | else | |
301 | function_trace_op = ftrace_ops_list; | |
b848914c | 302 | func = ftrace_ops_list->func; |
2f5f6ad9 SR |
303 | } else { |
304 | /* Just use the default ftrace_ops */ | |
305 | function_trace_op = &ftrace_list_end; | |
b848914c | 306 | func = ftrace_ops_list_func; |
2f5f6ad9 | 307 | } |
2b499381 | 308 | |
491d0dcf | 309 | ftrace_trace_function = func; |
491d0dcf SR |
310 | } |
311 | ||
2b499381 | 312 | static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
3d083395 | 313 | { |
2b499381 | 314 | ops->next = *list; |
16444a8a | 315 | /* |
b848914c | 316 | * We are entering ops into the list but another |
16444a8a ACM |
317 | * CPU might be walking that list. We need to make sure |
318 | * the ops->next pointer is valid before another CPU sees | |
b848914c | 319 | * the ops pointer included into the list. |
16444a8a | 320 | */ |
2b499381 | 321 | rcu_assign_pointer(*list, ops); |
16444a8a ACM |
322 | } |
323 | ||
2b499381 | 324 | static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
16444a8a | 325 | { |
16444a8a | 326 | struct ftrace_ops **p; |
16444a8a ACM |
327 | |
328 | /* | |
3d083395 SR |
329 | * If we are removing the last function, then simply point |
330 | * to the ftrace_stub. | |
16444a8a | 331 | */ |
2b499381 SR |
332 | if (*list == ops && ops->next == &ftrace_list_end) { |
333 | *list = &ftrace_list_end; | |
e6ea44e9 | 334 | return 0; |
16444a8a ACM |
335 | } |
336 | ||
2b499381 | 337 | for (p = list; *p != &ftrace_list_end; p = &(*p)->next) |
16444a8a ACM |
338 | if (*p == ops) |
339 | break; | |
340 | ||
e6ea44e9 SR |
341 | if (*p != ops) |
342 | return -1; | |
16444a8a ACM |
343 | |
344 | *p = (*p)->next; | |
2b499381 SR |
345 | return 0; |
346 | } | |
16444a8a | 347 | |
e248491a JO |
348 | static void add_ftrace_list_ops(struct ftrace_ops **list, |
349 | struct ftrace_ops *main_ops, | |
350 | struct ftrace_ops *ops) | |
351 | { | |
352 | int first = *list == &ftrace_list_end; | |
353 | add_ftrace_ops(list, ops); | |
354 | if (first) | |
355 | add_ftrace_ops(&ftrace_ops_list, main_ops); | |
356 | } | |
357 | ||
358 | static int remove_ftrace_list_ops(struct ftrace_ops **list, | |
359 | struct ftrace_ops *main_ops, | |
360 | struct ftrace_ops *ops) | |
361 | { | |
362 | int ret = remove_ftrace_ops(list, ops); | |
363 | if (!ret && *list == &ftrace_list_end) | |
364 | ret = remove_ftrace_ops(&ftrace_ops_list, main_ops); | |
365 | return ret; | |
366 | } | |
367 | ||
2b499381 SR |
368 | static int __register_ftrace_function(struct ftrace_ops *ops) |
369 | { | |
8d240dd8 | 370 | if (unlikely(ftrace_disabled)) |
2b499381 SR |
371 | return -ENODEV; |
372 | ||
373 | if (FTRACE_WARN_ON(ops == &global_ops)) | |
374 | return -EINVAL; | |
375 | ||
b848914c SR |
376 | if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) |
377 | return -EBUSY; | |
378 | ||
e248491a JO |
379 | /* We don't support both control and global flags set. */ |
380 | if ((ops->flags & FL_GLOBAL_CONTROL_MASK) == FL_GLOBAL_CONTROL_MASK) | |
381 | return -EINVAL; | |
382 | ||
06aeaaea | 383 | #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
08f6fba5 SR |
384 | /* |
385 | * If the ftrace_ops specifies SAVE_REGS, then it only can be used | |
386 | * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set. | |
387 | * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant. | |
388 | */ | |
389 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS && | |
390 | !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)) | |
391 | return -EINVAL; | |
392 | ||
393 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED) | |
394 | ops->flags |= FTRACE_OPS_FL_SAVE_REGS; | |
395 | #endif | |
396 | ||
cdbe61bf SR |
397 | if (!core_kernel_data((unsigned long)ops)) |
398 | ops->flags |= FTRACE_OPS_FL_DYNAMIC; | |
399 | ||
b848914c | 400 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { |
e248491a | 401 | add_ftrace_list_ops(&ftrace_global_list, &global_ops, ops); |
b848914c | 402 | ops->flags |= FTRACE_OPS_FL_ENABLED; |
e248491a JO |
403 | } else if (ops->flags & FTRACE_OPS_FL_CONTROL) { |
404 | if (control_ops_alloc(ops)) | |
405 | return -ENOMEM; | |
406 | add_ftrace_list_ops(&ftrace_control_list, &control_ops, ops); | |
b848914c SR |
407 | } else |
408 | add_ftrace_ops(&ftrace_ops_list, ops); | |
409 | ||
2b499381 SR |
410 | if (ftrace_enabled) |
411 | update_ftrace_function(); | |
412 | ||
413 | return 0; | |
414 | } | |
415 | ||
7614c3dc SR |
416 | static void ftrace_sync(struct work_struct *work) |
417 | { | |
418 | /* | |
419 | * This function is just a stub to implement a hard force | |
420 | * of synchronize_sched(). This requires synchronizing | |
421 | * tasks even in userspace and idle. | |
422 | * | |
423 | * Yes, function tracing is rude. | |
424 | */ | |
425 | } | |
426 | ||
2b499381 SR |
427 | static int __unregister_ftrace_function(struct ftrace_ops *ops) |
428 | { | |
429 | int ret; | |
430 | ||
431 | if (ftrace_disabled) | |
432 | return -ENODEV; | |
433 | ||
b848914c SR |
434 | if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) |
435 | return -EBUSY; | |
436 | ||
2b499381 SR |
437 | if (FTRACE_WARN_ON(ops == &global_ops)) |
438 | return -EINVAL; | |
439 | ||
b848914c | 440 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { |
e248491a JO |
441 | ret = remove_ftrace_list_ops(&ftrace_global_list, |
442 | &global_ops, ops); | |
b848914c SR |
443 | if (!ret) |
444 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; | |
e248491a JO |
445 | } else if (ops->flags & FTRACE_OPS_FL_CONTROL) { |
446 | ret = remove_ftrace_list_ops(&ftrace_control_list, | |
447 | &control_ops, ops); | |
448 | if (!ret) { | |
449 | /* | |
450 | * The ftrace_ops is now removed from the list, | |
451 | * so there'll be no new users. We must ensure | |
452 | * all current users are done before we free | |
453 | * the control data. | |
7614c3dc SR |
454 | * Note synchronize_sched() is not enough, as we |
455 | * use preempt_disable() to do RCU, but the function | |
456 | * tracer can be called where RCU is not active | |
457 | * (before user_exit()). | |
e248491a | 458 | */ |
7614c3dc | 459 | schedule_on_each_cpu(ftrace_sync); |
e248491a JO |
460 | control_ops_free(ops); |
461 | } | |
b848914c SR |
462 | } else |
463 | ret = remove_ftrace_ops(&ftrace_ops_list, ops); | |
464 | ||
2b499381 SR |
465 | if (ret < 0) |
466 | return ret; | |
b848914c | 467 | |
491d0dcf SR |
468 | if (ftrace_enabled) |
469 | update_ftrace_function(); | |
16444a8a | 470 | |
cdbe61bf SR |
471 | /* |
472 | * Dynamic ops may be freed, we must make sure that all | |
473 | * callers are done before leaving this function. | |
7614c3dc SR |
474 | * |
475 | * Again, normal synchronize_sched() is not good enough. | |
476 | * We need to do a hard force of sched synchronization. | |
cdbe61bf SR |
477 | */ |
478 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC) | |
7614c3dc SR |
479 | schedule_on_each_cpu(ftrace_sync); |
480 | ||
cdbe61bf | 481 | |
e6ea44e9 | 482 | return 0; |
3d083395 SR |
483 | } |
484 | ||
df4fc315 SR |
485 | static void ftrace_update_pid_func(void) |
486 | { | |
491d0dcf | 487 | /* Only do something if we are tracing something */ |
df4fc315 | 488 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 489 | return; |
df4fc315 | 490 | |
491d0dcf | 491 | update_ftrace_function(); |
df4fc315 SR |
492 | } |
493 | ||
493762fc SR |
494 | #ifdef CONFIG_FUNCTION_PROFILER |
495 | struct ftrace_profile { | |
496 | struct hlist_node node; | |
497 | unsigned long ip; | |
498 | unsigned long counter; | |
0706f1c4 SR |
499 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
500 | unsigned long long time; | |
e330b3bc | 501 | unsigned long long time_squared; |
0706f1c4 | 502 | #endif |
8fc0c701 SR |
503 | }; |
504 | ||
493762fc SR |
505 | struct ftrace_profile_page { |
506 | struct ftrace_profile_page *next; | |
507 | unsigned long index; | |
508 | struct ftrace_profile records[]; | |
d61f82d0 SR |
509 | }; |
510 | ||
cafb168a SR |
511 | struct ftrace_profile_stat { |
512 | atomic_t disabled; | |
513 | struct hlist_head *hash; | |
514 | struct ftrace_profile_page *pages; | |
515 | struct ftrace_profile_page *start; | |
516 | struct tracer_stat stat; | |
517 | }; | |
518 | ||
493762fc SR |
519 | #define PROFILE_RECORDS_SIZE \ |
520 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 521 | |
493762fc SR |
522 | #define PROFILES_PER_PAGE \ |
523 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 524 | |
fb9fb015 SR |
525 | static int ftrace_profile_enabled __read_mostly; |
526 | ||
527 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
528 | static DEFINE_MUTEX(ftrace_profile_lock); |
529 | ||
cafb168a | 530 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc | 531 | |
20079ebe NK |
532 | #define FTRACE_PROFILE_HASH_BITS 10 |
533 | #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS) | |
493762fc | 534 | |
bac429f0 SR |
535 | static void * |
536 | function_stat_next(void *v, int idx) | |
537 | { | |
493762fc SR |
538 | struct ftrace_profile *rec = v; |
539 | struct ftrace_profile_page *pg; | |
bac429f0 | 540 | |
493762fc | 541 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
542 | |
543 | again: | |
0296e425 LZ |
544 | if (idx != 0) |
545 | rec++; | |
546 | ||
bac429f0 SR |
547 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
548 | pg = pg->next; | |
549 | if (!pg) | |
550 | return NULL; | |
551 | rec = &pg->records[0]; | |
493762fc SR |
552 | if (!rec->counter) |
553 | goto again; | |
bac429f0 SR |
554 | } |
555 | ||
bac429f0 SR |
556 | return rec; |
557 | } | |
558 | ||
559 | static void *function_stat_start(struct tracer_stat *trace) | |
560 | { | |
cafb168a SR |
561 | struct ftrace_profile_stat *stat = |
562 | container_of(trace, struct ftrace_profile_stat, stat); | |
563 | ||
564 | if (!stat || !stat->start) | |
565 | return NULL; | |
566 | ||
567 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
568 | } |
569 | ||
0706f1c4 SR |
570 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
571 | /* function graph compares on total time */ | |
572 | static int function_stat_cmp(void *p1, void *p2) | |
573 | { | |
574 | struct ftrace_profile *a = p1; | |
575 | struct ftrace_profile *b = p2; | |
576 | ||
577 | if (a->time < b->time) | |
578 | return -1; | |
579 | if (a->time > b->time) | |
580 | return 1; | |
581 | else | |
582 | return 0; | |
583 | } | |
584 | #else | |
585 | /* not function graph compares against hits */ | |
bac429f0 SR |
586 | static int function_stat_cmp(void *p1, void *p2) |
587 | { | |
493762fc SR |
588 | struct ftrace_profile *a = p1; |
589 | struct ftrace_profile *b = p2; | |
bac429f0 SR |
590 | |
591 | if (a->counter < b->counter) | |
592 | return -1; | |
593 | if (a->counter > b->counter) | |
594 | return 1; | |
595 | else | |
596 | return 0; | |
597 | } | |
0706f1c4 | 598 | #endif |
bac429f0 SR |
599 | |
600 | static int function_stat_headers(struct seq_file *m) | |
601 | { | |
0706f1c4 | 602 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b | 603 | seq_printf(m, " Function " |
e330b3bc | 604 | "Hit Time Avg s^2\n" |
34886c8b | 605 | " -------- " |
e330b3bc | 606 | "--- ---- --- ---\n"); |
0706f1c4 | 607 | #else |
bac429f0 SR |
608 | seq_printf(m, " Function Hit\n" |
609 | " -------- ---\n"); | |
0706f1c4 | 610 | #endif |
bac429f0 SR |
611 | return 0; |
612 | } | |
613 | ||
614 | static int function_stat_show(struct seq_file *m, void *v) | |
615 | { | |
493762fc | 616 | struct ftrace_profile *rec = v; |
bac429f0 | 617 | char str[KSYM_SYMBOL_LEN]; |
3aaba20f | 618 | int ret = 0; |
0706f1c4 | 619 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
620 | static struct trace_seq s; |
621 | unsigned long long avg; | |
e330b3bc | 622 | unsigned long long stddev; |
0706f1c4 | 623 | #endif |
3aaba20f LZ |
624 | mutex_lock(&ftrace_profile_lock); |
625 | ||
626 | /* we raced with function_profile_reset() */ | |
627 | if (unlikely(rec->counter == 0)) { | |
628 | ret = -EBUSY; | |
629 | goto out; | |
630 | } | |
bac429f0 SR |
631 | |
632 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
0706f1c4 SR |
633 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
634 | ||
635 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
636 | seq_printf(m, " "); | |
34886c8b SR |
637 | avg = rec->time; |
638 | do_div(avg, rec->counter); | |
639 | ||
e330b3bc CD |
640 | /* Sample standard deviation (s^2) */ |
641 | if (rec->counter <= 1) | |
642 | stddev = 0; | |
643 | else { | |
52d85d76 JL |
644 | /* |
645 | * Apply Welford's method: | |
646 | * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2) | |
647 | */ | |
648 | stddev = rec->counter * rec->time_squared - | |
649 | rec->time * rec->time; | |
650 | ||
e330b3bc CD |
651 | /* |
652 | * Divide only 1000 for ns^2 -> us^2 conversion. | |
653 | * trace_print_graph_duration will divide 1000 again. | |
654 | */ | |
52d85d76 | 655 | do_div(stddev, rec->counter * (rec->counter - 1) * 1000); |
e330b3bc CD |
656 | } |
657 | ||
34886c8b SR |
658 | trace_seq_init(&s); |
659 | trace_print_graph_duration(rec->time, &s); | |
660 | trace_seq_puts(&s, " "); | |
661 | trace_print_graph_duration(avg, &s); | |
e330b3bc CD |
662 | trace_seq_puts(&s, " "); |
663 | trace_print_graph_duration(stddev, &s); | |
0706f1c4 | 664 | trace_print_seq(m, &s); |
0706f1c4 SR |
665 | #endif |
666 | seq_putc(m, '\n'); | |
3aaba20f LZ |
667 | out: |
668 | mutex_unlock(&ftrace_profile_lock); | |
bac429f0 | 669 | |
3aaba20f | 670 | return ret; |
bac429f0 SR |
671 | } |
672 | ||
cafb168a | 673 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 674 | { |
493762fc | 675 | struct ftrace_profile_page *pg; |
bac429f0 | 676 | |
cafb168a | 677 | pg = stat->pages = stat->start; |
bac429f0 | 678 | |
493762fc SR |
679 | while (pg) { |
680 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
681 | pg->index = 0; | |
682 | pg = pg->next; | |
bac429f0 SR |
683 | } |
684 | ||
cafb168a | 685 | memset(stat->hash, 0, |
493762fc SR |
686 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
687 | } | |
bac429f0 | 688 | |
cafb168a | 689 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
690 | { |
691 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
692 | int functions; |
693 | int pages; | |
493762fc | 694 | int i; |
bac429f0 | 695 | |
493762fc | 696 | /* If we already allocated, do nothing */ |
cafb168a | 697 | if (stat->pages) |
493762fc | 698 | return 0; |
bac429f0 | 699 | |
cafb168a SR |
700 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
701 | if (!stat->pages) | |
493762fc | 702 | return -ENOMEM; |
bac429f0 | 703 | |
318e0a73 SR |
704 | #ifdef CONFIG_DYNAMIC_FTRACE |
705 | functions = ftrace_update_tot_cnt; | |
706 | #else | |
707 | /* | |
708 | * We do not know the number of functions that exist because | |
709 | * dynamic tracing is what counts them. With past experience | |
710 | * we have around 20K functions. That should be more than enough. | |
711 | * It is highly unlikely we will execute every function in | |
712 | * the kernel. | |
713 | */ | |
714 | functions = 20000; | |
715 | #endif | |
716 | ||
cafb168a | 717 | pg = stat->start = stat->pages; |
bac429f0 | 718 | |
318e0a73 SR |
719 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
720 | ||
39e30cd1 | 721 | for (i = 1; i < pages; i++) { |
493762fc | 722 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 723 | if (!pg->next) |
318e0a73 | 724 | goto out_free; |
493762fc SR |
725 | pg = pg->next; |
726 | } | |
727 | ||
728 | return 0; | |
318e0a73 SR |
729 | |
730 | out_free: | |
731 | pg = stat->start; | |
732 | while (pg) { | |
733 | unsigned long tmp = (unsigned long)pg; | |
734 | ||
735 | pg = pg->next; | |
736 | free_page(tmp); | |
737 | } | |
738 | ||
318e0a73 SR |
739 | stat->pages = NULL; |
740 | stat->start = NULL; | |
741 | ||
742 | return -ENOMEM; | |
bac429f0 SR |
743 | } |
744 | ||
cafb168a | 745 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 746 | { |
cafb168a | 747 | struct ftrace_profile_stat *stat; |
493762fc | 748 | int size; |
bac429f0 | 749 | |
cafb168a SR |
750 | stat = &per_cpu(ftrace_profile_stats, cpu); |
751 | ||
752 | if (stat->hash) { | |
493762fc | 753 | /* If the profile is already created, simply reset it */ |
cafb168a | 754 | ftrace_profile_reset(stat); |
493762fc SR |
755 | return 0; |
756 | } | |
bac429f0 | 757 | |
493762fc SR |
758 | /* |
759 | * We are profiling all functions, but usually only a few thousand | |
760 | * functions are hit. We'll make a hash of 1024 items. | |
761 | */ | |
762 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 763 | |
cafb168a | 764 | stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
493762fc | 765 | |
cafb168a | 766 | if (!stat->hash) |
493762fc SR |
767 | return -ENOMEM; |
768 | ||
318e0a73 | 769 | /* Preallocate the function profiling pages */ |
cafb168a SR |
770 | if (ftrace_profile_pages_init(stat) < 0) { |
771 | kfree(stat->hash); | |
772 | stat->hash = NULL; | |
493762fc SR |
773 | return -ENOMEM; |
774 | } | |
775 | ||
776 | return 0; | |
bac429f0 SR |
777 | } |
778 | ||
cafb168a SR |
779 | static int ftrace_profile_init(void) |
780 | { | |
781 | int cpu; | |
782 | int ret = 0; | |
783 | ||
784 | for_each_online_cpu(cpu) { | |
785 | ret = ftrace_profile_init_cpu(cpu); | |
786 | if (ret) | |
787 | break; | |
788 | } | |
789 | ||
790 | return ret; | |
791 | } | |
792 | ||
493762fc | 793 | /* interrupts must be disabled */ |
cafb168a SR |
794 | static struct ftrace_profile * |
795 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 796 | { |
493762fc | 797 | struct ftrace_profile *rec; |
bac429f0 | 798 | struct hlist_head *hhd; |
bac429f0 SR |
799 | unsigned long key; |
800 | ||
20079ebe | 801 | key = hash_long(ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 802 | hhd = &stat->hash[key]; |
bac429f0 SR |
803 | |
804 | if (hlist_empty(hhd)) | |
805 | return NULL; | |
806 | ||
1bb539ca | 807 | hlist_for_each_entry_rcu_notrace(rec, hhd, node) { |
bac429f0 | 808 | if (rec->ip == ip) |
493762fc SR |
809 | return rec; |
810 | } | |
811 | ||
812 | return NULL; | |
813 | } | |
814 | ||
cafb168a SR |
815 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
816 | struct ftrace_profile *rec) | |
493762fc SR |
817 | { |
818 | unsigned long key; | |
819 | ||
20079ebe | 820 | key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 821 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
822 | } |
823 | ||
318e0a73 SR |
824 | /* |
825 | * The memory is already allocated, this simply finds a new record to use. | |
826 | */ | |
493762fc | 827 | static struct ftrace_profile * |
318e0a73 | 828 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
829 | { |
830 | struct ftrace_profile *rec = NULL; | |
831 | ||
318e0a73 | 832 | /* prevent recursion (from NMIs) */ |
cafb168a | 833 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
834 | goto out; |
835 | ||
493762fc | 836 | /* |
318e0a73 SR |
837 | * Try to find the function again since an NMI |
838 | * could have added it | |
493762fc | 839 | */ |
cafb168a | 840 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 841 | if (rec) |
cafb168a | 842 | goto out; |
493762fc | 843 | |
cafb168a SR |
844 | if (stat->pages->index == PROFILES_PER_PAGE) { |
845 | if (!stat->pages->next) | |
846 | goto out; | |
847 | stat->pages = stat->pages->next; | |
bac429f0 | 848 | } |
493762fc | 849 | |
cafb168a | 850 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 851 | rec->ip = ip; |
cafb168a | 852 | ftrace_add_profile(stat, rec); |
493762fc | 853 | |
bac429f0 | 854 | out: |
cafb168a | 855 | atomic_dec(&stat->disabled); |
bac429f0 SR |
856 | |
857 | return rec; | |
858 | } | |
859 | ||
860 | static void | |
2f5f6ad9 | 861 | function_profile_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 862 | struct ftrace_ops *ops, struct pt_regs *regs) |
bac429f0 | 863 | { |
cafb168a | 864 | struct ftrace_profile_stat *stat; |
493762fc | 865 | struct ftrace_profile *rec; |
bac429f0 SR |
866 | unsigned long flags; |
867 | ||
868 | if (!ftrace_profile_enabled) | |
869 | return; | |
870 | ||
871 | local_irq_save(flags); | |
cafb168a SR |
872 | |
873 | stat = &__get_cpu_var(ftrace_profile_stats); | |
0f6ce3de | 874 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
875 | goto out; |
876 | ||
877 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 878 | if (!rec) { |
318e0a73 | 879 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
880 | if (!rec) |
881 | goto out; | |
882 | } | |
bac429f0 SR |
883 | |
884 | rec->counter++; | |
885 | out: | |
886 | local_irq_restore(flags); | |
887 | } | |
888 | ||
0706f1c4 SR |
889 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
890 | static int profile_graph_entry(struct ftrace_graph_ent *trace) | |
891 | { | |
a1e2e31d | 892 | function_profile_call(trace->func, 0, NULL, NULL); |
0706f1c4 SR |
893 | return 1; |
894 | } | |
895 | ||
896 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
897 | { | |
cafb168a | 898 | struct ftrace_profile_stat *stat; |
a2a16d6a | 899 | unsigned long long calltime; |
0706f1c4 | 900 | struct ftrace_profile *rec; |
cafb168a | 901 | unsigned long flags; |
0706f1c4 SR |
902 | |
903 | local_irq_save(flags); | |
cafb168a | 904 | stat = &__get_cpu_var(ftrace_profile_stats); |
0f6ce3de | 905 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
906 | goto out; |
907 | ||
37e44bc5 SR |
908 | /* If the calltime was zero'd ignore it */ |
909 | if (!trace->calltime) | |
910 | goto out; | |
911 | ||
a2a16d6a SR |
912 | calltime = trace->rettime - trace->calltime; |
913 | ||
914 | if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) { | |
915 | int index; | |
916 | ||
917 | index = trace->depth; | |
918 | ||
919 | /* Append this call time to the parent time to subtract */ | |
920 | if (index) | |
921 | current->ret_stack[index - 1].subtime += calltime; | |
922 | ||
923 | if (current->ret_stack[index].subtime < calltime) | |
924 | calltime -= current->ret_stack[index].subtime; | |
925 | else | |
926 | calltime = 0; | |
927 | } | |
928 | ||
cafb168a | 929 | rec = ftrace_find_profiled_func(stat, trace->func); |
e330b3bc | 930 | if (rec) { |
a2a16d6a | 931 | rec->time += calltime; |
e330b3bc CD |
932 | rec->time_squared += calltime * calltime; |
933 | } | |
a2a16d6a | 934 | |
cafb168a | 935 | out: |
0706f1c4 SR |
936 | local_irq_restore(flags); |
937 | } | |
938 | ||
939 | static int register_ftrace_profiler(void) | |
940 | { | |
941 | return register_ftrace_graph(&profile_graph_return, | |
942 | &profile_graph_entry); | |
943 | } | |
944 | ||
945 | static void unregister_ftrace_profiler(void) | |
946 | { | |
947 | unregister_ftrace_graph(); | |
948 | } | |
949 | #else | |
bd38c0e6 | 950 | static struct ftrace_ops ftrace_profile_ops __read_mostly = { |
fb9fb015 | 951 | .func = function_profile_call, |
f04f24fb MH |
952 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, |
953 | INIT_REGEX_LOCK(ftrace_profile_ops) | |
bac429f0 SR |
954 | }; |
955 | ||
0706f1c4 SR |
956 | static int register_ftrace_profiler(void) |
957 | { | |
958 | return register_ftrace_function(&ftrace_profile_ops); | |
959 | } | |
960 | ||
961 | static void unregister_ftrace_profiler(void) | |
962 | { | |
963 | unregister_ftrace_function(&ftrace_profile_ops); | |
964 | } | |
965 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
966 | ||
bac429f0 SR |
967 | static ssize_t |
968 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
969 | size_t cnt, loff_t *ppos) | |
970 | { | |
971 | unsigned long val; | |
bac429f0 SR |
972 | int ret; |
973 | ||
22fe9b54 PH |
974 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
975 | if (ret) | |
bac429f0 SR |
976 | return ret; |
977 | ||
978 | val = !!val; | |
979 | ||
980 | mutex_lock(&ftrace_profile_lock); | |
981 | if (ftrace_profile_enabled ^ val) { | |
982 | if (val) { | |
493762fc SR |
983 | ret = ftrace_profile_init(); |
984 | if (ret < 0) { | |
985 | cnt = ret; | |
986 | goto out; | |
987 | } | |
988 | ||
0706f1c4 SR |
989 | ret = register_ftrace_profiler(); |
990 | if (ret < 0) { | |
991 | cnt = ret; | |
992 | goto out; | |
993 | } | |
bac429f0 SR |
994 | ftrace_profile_enabled = 1; |
995 | } else { | |
996 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
997 | /* |
998 | * unregister_ftrace_profiler calls stop_machine | |
999 | * so this acts like an synchronize_sched. | |
1000 | */ | |
0706f1c4 | 1001 | unregister_ftrace_profiler(); |
bac429f0 SR |
1002 | } |
1003 | } | |
493762fc | 1004 | out: |
bac429f0 SR |
1005 | mutex_unlock(&ftrace_profile_lock); |
1006 | ||
cf8517cf | 1007 | *ppos += cnt; |
bac429f0 SR |
1008 | |
1009 | return cnt; | |
1010 | } | |
1011 | ||
493762fc SR |
1012 | static ssize_t |
1013 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
1014 | size_t cnt, loff_t *ppos) | |
1015 | { | |
fb9fb015 | 1016 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
1017 | int r; |
1018 | ||
1019 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
1020 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
1021 | } | |
1022 | ||
bac429f0 SR |
1023 | static const struct file_operations ftrace_profile_fops = { |
1024 | .open = tracing_open_generic, | |
1025 | .read = ftrace_profile_read, | |
1026 | .write = ftrace_profile_write, | |
6038f373 | 1027 | .llseek = default_llseek, |
bac429f0 SR |
1028 | }; |
1029 | ||
cafb168a SR |
1030 | /* used to initialize the real stat files */ |
1031 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
1032 | .name = "functions", |
1033 | .stat_start = function_stat_start, | |
1034 | .stat_next = function_stat_next, | |
1035 | .stat_cmp = function_stat_cmp, | |
1036 | .stat_headers = function_stat_headers, | |
1037 | .stat_show = function_stat_show | |
cafb168a SR |
1038 | }; |
1039 | ||
6ab5d668 | 1040 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 | 1041 | { |
cafb168a | 1042 | struct ftrace_profile_stat *stat; |
bac429f0 | 1043 | struct dentry *entry; |
cafb168a | 1044 | char *name; |
bac429f0 | 1045 | int ret; |
cafb168a SR |
1046 | int cpu; |
1047 | ||
1048 | for_each_possible_cpu(cpu) { | |
1049 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
1050 | ||
1051 | /* allocate enough for function name + cpu number */ | |
1052 | name = kmalloc(32, GFP_KERNEL); | |
1053 | if (!name) { | |
1054 | /* | |
1055 | * The files created are permanent, if something happens | |
1056 | * we still do not free memory. | |
1057 | */ | |
cafb168a SR |
1058 | WARN(1, |
1059 | "Could not allocate stat file for cpu %d\n", | |
1060 | cpu); | |
1061 | return; | |
1062 | } | |
1063 | stat->stat = function_stats; | |
1064 | snprintf(name, 32, "function%d", cpu); | |
1065 | stat->stat.name = name; | |
1066 | ret = register_stat_tracer(&stat->stat); | |
1067 | if (ret) { | |
1068 | WARN(1, | |
1069 | "Could not register function stat for cpu %d\n", | |
1070 | cpu); | |
1071 | kfree(name); | |
1072 | return; | |
1073 | } | |
bac429f0 SR |
1074 | } |
1075 | ||
1076 | entry = debugfs_create_file("function_profile_enabled", 0644, | |
1077 | d_tracer, NULL, &ftrace_profile_fops); | |
1078 | if (!entry) | |
1079 | pr_warning("Could not create debugfs " | |
1080 | "'function_profile_enabled' entry\n"); | |
1081 | } | |
1082 | ||
bac429f0 | 1083 | #else /* CONFIG_FUNCTION_PROFILER */ |
6ab5d668 | 1084 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 SR |
1085 | { |
1086 | } | |
bac429f0 SR |
1087 | #endif /* CONFIG_FUNCTION_PROFILER */ |
1088 | ||
493762fc SR |
1089 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; |
1090 | ||
7f49ef69 SRRH |
1091 | loff_t |
1092 | ftrace_filter_lseek(struct file *file, loff_t offset, int whence) | |
1093 | { | |
1094 | loff_t ret; | |
1095 | ||
1096 | if (file->f_mode & FMODE_READ) | |
1097 | ret = seq_lseek(file, offset, whence); | |
1098 | else | |
1099 | file->f_pos = ret = 1; | |
1100 | ||
1101 | return ret; | |
1102 | } | |
1103 | ||
493762fc SR |
1104 | #ifdef CONFIG_DYNAMIC_FTRACE |
1105 | ||
1106 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD | |
1107 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
1108 | #endif | |
1109 | ||
1110 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; | |
1111 | ||
1112 | struct ftrace_func_probe { | |
1113 | struct hlist_node node; | |
1114 | struct ftrace_probe_ops *ops; | |
1115 | unsigned long flags; | |
1116 | unsigned long ip; | |
1117 | void *data; | |
7818b388 | 1118 | struct list_head free_list; |
493762fc SR |
1119 | }; |
1120 | ||
b448c4e3 SR |
1121 | struct ftrace_func_entry { |
1122 | struct hlist_node hlist; | |
1123 | unsigned long ip; | |
1124 | }; | |
1125 | ||
1126 | struct ftrace_hash { | |
1127 | unsigned long size_bits; | |
1128 | struct hlist_head *buckets; | |
1129 | unsigned long count; | |
07fd5515 | 1130 | struct rcu_head rcu; |
b448c4e3 SR |
1131 | }; |
1132 | ||
33dc9b12 SR |
1133 | /* |
1134 | * We make these constant because no one should touch them, | |
1135 | * but they are used as the default "empty hash", to avoid allocating | |
1136 | * it all the time. These are in a read only section such that if | |
1137 | * anyone does try to modify it, it will cause an exception. | |
1138 | */ | |
1139 | static const struct hlist_head empty_buckets[1]; | |
1140 | static const struct ftrace_hash empty_hash = { | |
1141 | .buckets = (struct hlist_head *)empty_buckets, | |
1cf41dd7 | 1142 | }; |
33dc9b12 | 1143 | #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash) |
493762fc | 1144 | |
2b499381 | 1145 | static struct ftrace_ops global_ops = { |
f45948e8 | 1146 | .func = ftrace_stub, |
33dc9b12 SR |
1147 | .notrace_hash = EMPTY_HASH, |
1148 | .filter_hash = EMPTY_HASH, | |
f04f24fb MH |
1149 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, |
1150 | INIT_REGEX_LOCK(global_ops) | |
f45948e8 SR |
1151 | }; |
1152 | ||
493762fc SR |
1153 | struct ftrace_page { |
1154 | struct ftrace_page *next; | |
a7900875 | 1155 | struct dyn_ftrace *records; |
493762fc | 1156 | int index; |
a7900875 | 1157 | int size; |
493762fc SR |
1158 | }; |
1159 | ||
85ae32ae SR |
1160 | static struct ftrace_page *ftrace_new_pgs; |
1161 | ||
a7900875 SR |
1162 | #define ENTRY_SIZE sizeof(struct dyn_ftrace) |
1163 | #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE) | |
493762fc SR |
1164 | |
1165 | /* estimate from running different kernels */ | |
1166 | #define NR_TO_INIT 10000 | |
1167 | ||
1168 | static struct ftrace_page *ftrace_pages_start; | |
1169 | static struct ftrace_page *ftrace_pages; | |
1170 | ||
06a51d93 SR |
1171 | static bool ftrace_hash_empty(struct ftrace_hash *hash) |
1172 | { | |
1173 | return !hash || !hash->count; | |
1174 | } | |
1175 | ||
b448c4e3 SR |
1176 | static struct ftrace_func_entry * |
1177 | ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
1178 | { | |
1179 | unsigned long key; | |
1180 | struct ftrace_func_entry *entry; | |
1181 | struct hlist_head *hhd; | |
b448c4e3 | 1182 | |
06a51d93 | 1183 | if (ftrace_hash_empty(hash)) |
b448c4e3 SR |
1184 | return NULL; |
1185 | ||
1186 | if (hash->size_bits > 0) | |
1187 | key = hash_long(ip, hash->size_bits); | |
1188 | else | |
1189 | key = 0; | |
1190 | ||
1191 | hhd = &hash->buckets[key]; | |
1192 | ||
1bb539ca | 1193 | hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) { |
b448c4e3 SR |
1194 | if (entry->ip == ip) |
1195 | return entry; | |
1196 | } | |
1197 | return NULL; | |
1198 | } | |
1199 | ||
33dc9b12 SR |
1200 | static void __add_hash_entry(struct ftrace_hash *hash, |
1201 | struct ftrace_func_entry *entry) | |
b448c4e3 | 1202 | { |
b448c4e3 SR |
1203 | struct hlist_head *hhd; |
1204 | unsigned long key; | |
1205 | ||
b448c4e3 | 1206 | if (hash->size_bits) |
33dc9b12 | 1207 | key = hash_long(entry->ip, hash->size_bits); |
b448c4e3 SR |
1208 | else |
1209 | key = 0; | |
1210 | ||
b448c4e3 SR |
1211 | hhd = &hash->buckets[key]; |
1212 | hlist_add_head(&entry->hlist, hhd); | |
1213 | hash->count++; | |
33dc9b12 SR |
1214 | } |
1215 | ||
1216 | static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip) | |
1217 | { | |
1218 | struct ftrace_func_entry *entry; | |
1219 | ||
1220 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1221 | if (!entry) | |
1222 | return -ENOMEM; | |
1223 | ||
1224 | entry->ip = ip; | |
1225 | __add_hash_entry(hash, entry); | |
b448c4e3 SR |
1226 | |
1227 | return 0; | |
1228 | } | |
1229 | ||
1230 | static void | |
33dc9b12 | 1231 | free_hash_entry(struct ftrace_hash *hash, |
b448c4e3 SR |
1232 | struct ftrace_func_entry *entry) |
1233 | { | |
1234 | hlist_del(&entry->hlist); | |
1235 | kfree(entry); | |
1236 | hash->count--; | |
1237 | } | |
1238 | ||
33dc9b12 SR |
1239 | static void |
1240 | remove_hash_entry(struct ftrace_hash *hash, | |
1241 | struct ftrace_func_entry *entry) | |
1242 | { | |
1243 | hlist_del(&entry->hlist); | |
1244 | hash->count--; | |
1245 | } | |
1246 | ||
b448c4e3 SR |
1247 | static void ftrace_hash_clear(struct ftrace_hash *hash) |
1248 | { | |
1249 | struct hlist_head *hhd; | |
b67bfe0d | 1250 | struct hlist_node *tn; |
b448c4e3 SR |
1251 | struct ftrace_func_entry *entry; |
1252 | int size = 1 << hash->size_bits; | |
1253 | int i; | |
1254 | ||
33dc9b12 SR |
1255 | if (!hash->count) |
1256 | return; | |
1257 | ||
b448c4e3 SR |
1258 | for (i = 0; i < size; i++) { |
1259 | hhd = &hash->buckets[i]; | |
b67bfe0d | 1260 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) |
33dc9b12 | 1261 | free_hash_entry(hash, entry); |
b448c4e3 SR |
1262 | } |
1263 | FTRACE_WARN_ON(hash->count); | |
1264 | } | |
1265 | ||
33dc9b12 SR |
1266 | static void free_ftrace_hash(struct ftrace_hash *hash) |
1267 | { | |
1268 | if (!hash || hash == EMPTY_HASH) | |
1269 | return; | |
1270 | ftrace_hash_clear(hash); | |
1271 | kfree(hash->buckets); | |
1272 | kfree(hash); | |
1273 | } | |
1274 | ||
07fd5515 SR |
1275 | static void __free_ftrace_hash_rcu(struct rcu_head *rcu) |
1276 | { | |
1277 | struct ftrace_hash *hash; | |
1278 | ||
1279 | hash = container_of(rcu, struct ftrace_hash, rcu); | |
1280 | free_ftrace_hash(hash); | |
1281 | } | |
1282 | ||
1283 | static void free_ftrace_hash_rcu(struct ftrace_hash *hash) | |
1284 | { | |
1285 | if (!hash || hash == EMPTY_HASH) | |
1286 | return; | |
1287 | call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu); | |
1288 | } | |
1289 | ||
5500fa51 JO |
1290 | void ftrace_free_filter(struct ftrace_ops *ops) |
1291 | { | |
f04f24fb | 1292 | ftrace_ops_init(ops); |
5500fa51 JO |
1293 | free_ftrace_hash(ops->filter_hash); |
1294 | free_ftrace_hash(ops->notrace_hash); | |
1295 | } | |
1296 | ||
33dc9b12 SR |
1297 | static struct ftrace_hash *alloc_ftrace_hash(int size_bits) |
1298 | { | |
1299 | struct ftrace_hash *hash; | |
1300 | int size; | |
1301 | ||
1302 | hash = kzalloc(sizeof(*hash), GFP_KERNEL); | |
1303 | if (!hash) | |
1304 | return NULL; | |
1305 | ||
1306 | size = 1 << size_bits; | |
47b0edcb | 1307 | hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL); |
33dc9b12 SR |
1308 | |
1309 | if (!hash->buckets) { | |
1310 | kfree(hash); | |
1311 | return NULL; | |
1312 | } | |
1313 | ||
1314 | hash->size_bits = size_bits; | |
1315 | ||
1316 | return hash; | |
1317 | } | |
1318 | ||
1319 | static struct ftrace_hash * | |
1320 | alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) | |
1321 | { | |
1322 | struct ftrace_func_entry *entry; | |
1323 | struct ftrace_hash *new_hash; | |
33dc9b12 SR |
1324 | int size; |
1325 | int ret; | |
1326 | int i; | |
1327 | ||
1328 | new_hash = alloc_ftrace_hash(size_bits); | |
1329 | if (!new_hash) | |
1330 | return NULL; | |
1331 | ||
1332 | /* Empty hash? */ | |
06a51d93 | 1333 | if (ftrace_hash_empty(hash)) |
33dc9b12 SR |
1334 | return new_hash; |
1335 | ||
1336 | size = 1 << hash->size_bits; | |
1337 | for (i = 0; i < size; i++) { | |
b67bfe0d | 1338 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { |
33dc9b12 SR |
1339 | ret = add_hash_entry(new_hash, entry->ip); |
1340 | if (ret < 0) | |
1341 | goto free_hash; | |
1342 | } | |
1343 | } | |
1344 | ||
1345 | FTRACE_WARN_ON(new_hash->count != hash->count); | |
1346 | ||
1347 | return new_hash; | |
1348 | ||
1349 | free_hash: | |
1350 | free_ftrace_hash(new_hash); | |
1351 | return NULL; | |
1352 | } | |
1353 | ||
41fb61c2 SR |
1354 | static void |
1355 | ftrace_hash_rec_disable(struct ftrace_ops *ops, int filter_hash); | |
1356 | static void | |
1357 | ftrace_hash_rec_enable(struct ftrace_ops *ops, int filter_hash); | |
1358 | ||
33dc9b12 | 1359 | static int |
41fb61c2 SR |
1360 | ftrace_hash_move(struct ftrace_ops *ops, int enable, |
1361 | struct ftrace_hash **dst, struct ftrace_hash *src) | |
33dc9b12 SR |
1362 | { |
1363 | struct ftrace_func_entry *entry; | |
b67bfe0d | 1364 | struct hlist_node *tn; |
33dc9b12 | 1365 | struct hlist_head *hhd; |
07fd5515 SR |
1366 | struct ftrace_hash *old_hash; |
1367 | struct ftrace_hash *new_hash; | |
33dc9b12 SR |
1368 | int size = src->count; |
1369 | int bits = 0; | |
41fb61c2 | 1370 | int ret; |
33dc9b12 SR |
1371 | int i; |
1372 | ||
41fb61c2 SR |
1373 | /* |
1374 | * Remove the current set, update the hash and add | |
1375 | * them back. | |
1376 | */ | |
1377 | ftrace_hash_rec_disable(ops, enable); | |
1378 | ||
33dc9b12 SR |
1379 | /* |
1380 | * If the new source is empty, just free dst and assign it | |
1381 | * the empty_hash. | |
1382 | */ | |
1383 | if (!src->count) { | |
07fd5515 SR |
1384 | free_ftrace_hash_rcu(*dst); |
1385 | rcu_assign_pointer(*dst, EMPTY_HASH); | |
d4d34b98 SR |
1386 | /* still need to update the function records */ |
1387 | ret = 0; | |
1388 | goto out; | |
33dc9b12 SR |
1389 | } |
1390 | ||
33dc9b12 SR |
1391 | /* |
1392 | * Make the hash size about 1/2 the # found | |
1393 | */ | |
1394 | for (size /= 2; size; size >>= 1) | |
1395 | bits++; | |
1396 | ||
1397 | /* Don't allocate too much */ | |
1398 | if (bits > FTRACE_HASH_MAX_BITS) | |
1399 | bits = FTRACE_HASH_MAX_BITS; | |
1400 | ||
41fb61c2 | 1401 | ret = -ENOMEM; |
07fd5515 SR |
1402 | new_hash = alloc_ftrace_hash(bits); |
1403 | if (!new_hash) | |
41fb61c2 | 1404 | goto out; |
33dc9b12 SR |
1405 | |
1406 | size = 1 << src->size_bits; | |
1407 | for (i = 0; i < size; i++) { | |
1408 | hhd = &src->buckets[i]; | |
b67bfe0d | 1409 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) { |
33dc9b12 | 1410 | remove_hash_entry(src, entry); |
07fd5515 | 1411 | __add_hash_entry(new_hash, entry); |
33dc9b12 SR |
1412 | } |
1413 | } | |
1414 | ||
07fd5515 SR |
1415 | old_hash = *dst; |
1416 | rcu_assign_pointer(*dst, new_hash); | |
1417 | free_ftrace_hash_rcu(old_hash); | |
1418 | ||
41fb61c2 SR |
1419 | ret = 0; |
1420 | out: | |
1421 | /* | |
1422 | * Enable regardless of ret: | |
1423 | * On success, we enable the new hash. | |
1424 | * On failure, we re-enable the original hash. | |
1425 | */ | |
1426 | ftrace_hash_rec_enable(ops, enable); | |
1427 | ||
1428 | return ret; | |
33dc9b12 SR |
1429 | } |
1430 | ||
b848914c SR |
1431 | /* |
1432 | * Test the hashes for this ops to see if we want to call | |
1433 | * the ops->func or not. | |
1434 | * | |
1435 | * It's a match if the ip is in the ops->filter_hash or | |
1436 | * the filter_hash does not exist or is empty, | |
1437 | * AND | |
1438 | * the ip is not in the ops->notrace_hash. | |
cdbe61bf SR |
1439 | * |
1440 | * This needs to be called with preemption disabled as | |
1441 | * the hashes are freed with call_rcu_sched(). | |
b848914c SR |
1442 | */ |
1443 | static int | |
195a8afc | 1444 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
b848914c SR |
1445 | { |
1446 | struct ftrace_hash *filter_hash; | |
1447 | struct ftrace_hash *notrace_hash; | |
1448 | int ret; | |
1449 | ||
195a8afc SRRH |
1450 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
1451 | /* | |
1452 | * There's a small race when adding ops that the ftrace handler | |
1453 | * that wants regs, may be called without them. We can not | |
1454 | * allow that handler to be called if regs is NULL. | |
1455 | */ | |
1456 | if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS)) | |
1457 | return 0; | |
1458 | #endif | |
1459 | ||
1bb539ca SR |
1460 | filter_hash = rcu_dereference_raw_notrace(ops->filter_hash); |
1461 | notrace_hash = rcu_dereference_raw_notrace(ops->notrace_hash); | |
b848914c | 1462 | |
06a51d93 | 1463 | if ((ftrace_hash_empty(filter_hash) || |
b848914c | 1464 | ftrace_lookup_ip(filter_hash, ip)) && |
06a51d93 | 1465 | (ftrace_hash_empty(notrace_hash) || |
b848914c SR |
1466 | !ftrace_lookup_ip(notrace_hash, ip))) |
1467 | ret = 1; | |
1468 | else | |
1469 | ret = 0; | |
b848914c SR |
1470 | |
1471 | return ret; | |
1472 | } | |
1473 | ||
493762fc SR |
1474 | /* |
1475 | * This is a double for. Do not use 'break' to break out of the loop, | |
1476 | * you must use a goto. | |
1477 | */ | |
1478 | #define do_for_each_ftrace_rec(pg, rec) \ | |
1479 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
1480 | int _____i; \ | |
1481 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
1482 | rec = &pg->records[_____i]; | |
1483 | ||
1484 | #define while_for_each_ftrace_rec() \ | |
1485 | } \ | |
1486 | } | |
1487 | ||
5855fead SR |
1488 | |
1489 | static int ftrace_cmp_recs(const void *a, const void *b) | |
1490 | { | |
a650e02a SR |
1491 | const struct dyn_ftrace *key = a; |
1492 | const struct dyn_ftrace *rec = b; | |
5855fead | 1493 | |
a650e02a | 1494 | if (key->flags < rec->ip) |
5855fead | 1495 | return -1; |
a650e02a SR |
1496 | if (key->ip >= rec->ip + MCOUNT_INSN_SIZE) |
1497 | return 1; | |
5855fead SR |
1498 | return 0; |
1499 | } | |
1500 | ||
f0cf973a | 1501 | static unsigned long ftrace_location_range(unsigned long start, unsigned long end) |
c88fd863 SR |
1502 | { |
1503 | struct ftrace_page *pg; | |
1504 | struct dyn_ftrace *rec; | |
5855fead | 1505 | struct dyn_ftrace key; |
c88fd863 | 1506 | |
a650e02a SR |
1507 | key.ip = start; |
1508 | key.flags = end; /* overload flags, as it is unsigned long */ | |
5855fead SR |
1509 | |
1510 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
a650e02a SR |
1511 | if (end < pg->records[0].ip || |
1512 | start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) | |
9644302e | 1513 | continue; |
5855fead SR |
1514 | rec = bsearch(&key, pg->records, pg->index, |
1515 | sizeof(struct dyn_ftrace), | |
1516 | ftrace_cmp_recs); | |
1517 | if (rec) | |
f0cf973a | 1518 | return rec->ip; |
5855fead | 1519 | } |
c88fd863 SR |
1520 | |
1521 | return 0; | |
1522 | } | |
1523 | ||
a650e02a SR |
1524 | /** |
1525 | * ftrace_location - return true if the ip giving is a traced location | |
1526 | * @ip: the instruction pointer to check | |
1527 | * | |
f0cf973a | 1528 | * Returns rec->ip if @ip given is a pointer to a ftrace location. |
a650e02a SR |
1529 | * That is, the instruction that is either a NOP or call to |
1530 | * the function tracer. It checks the ftrace internal tables to | |
1531 | * determine if the address belongs or not. | |
1532 | */ | |
f0cf973a | 1533 | unsigned long ftrace_location(unsigned long ip) |
a650e02a SR |
1534 | { |
1535 | return ftrace_location_range(ip, ip); | |
1536 | } | |
1537 | ||
1538 | /** | |
1539 | * ftrace_text_reserved - return true if range contains an ftrace location | |
1540 | * @start: start of range to search | |
1541 | * @end: end of range to search (inclusive). @end points to the last byte to check. | |
1542 | * | |
1543 | * Returns 1 if @start and @end contains a ftrace location. | |
1544 | * That is, the instruction that is either a NOP or call to | |
1545 | * the function tracer. It checks the ftrace internal tables to | |
1546 | * determine if the address belongs or not. | |
1547 | */ | |
1548 | int ftrace_text_reserved(void *start, void *end) | |
1549 | { | |
f0cf973a SR |
1550 | unsigned long ret; |
1551 | ||
1552 | ret = ftrace_location_range((unsigned long)start, | |
1553 | (unsigned long)end); | |
1554 | ||
1555 | return (int)!!ret; | |
a650e02a SR |
1556 | } |
1557 | ||
ed926f9b SR |
1558 | static void __ftrace_hash_rec_update(struct ftrace_ops *ops, |
1559 | int filter_hash, | |
1560 | bool inc) | |
1561 | { | |
1562 | struct ftrace_hash *hash; | |
1563 | struct ftrace_hash *other_hash; | |
1564 | struct ftrace_page *pg; | |
1565 | struct dyn_ftrace *rec; | |
1566 | int count = 0; | |
1567 | int all = 0; | |
1568 | ||
1569 | /* Only update if the ops has been registered */ | |
1570 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
1571 | return; | |
1572 | ||
1573 | /* | |
1574 | * In the filter_hash case: | |
1575 | * If the count is zero, we update all records. | |
1576 | * Otherwise we just update the items in the hash. | |
1577 | * | |
1578 | * In the notrace_hash case: | |
1579 | * We enable the update in the hash. | |
1580 | * As disabling notrace means enabling the tracing, | |
1581 | * and enabling notrace means disabling, the inc variable | |
1582 | * gets inversed. | |
1583 | */ | |
1584 | if (filter_hash) { | |
1585 | hash = ops->filter_hash; | |
1586 | other_hash = ops->notrace_hash; | |
06a51d93 | 1587 | if (ftrace_hash_empty(hash)) |
ed926f9b SR |
1588 | all = 1; |
1589 | } else { | |
1590 | inc = !inc; | |
1591 | hash = ops->notrace_hash; | |
1592 | other_hash = ops->filter_hash; | |
1593 | /* | |
1594 | * If the notrace hash has no items, | |
1595 | * then there's nothing to do. | |
1596 | */ | |
06a51d93 | 1597 | if (ftrace_hash_empty(hash)) |
ed926f9b SR |
1598 | return; |
1599 | } | |
1600 | ||
1601 | do_for_each_ftrace_rec(pg, rec) { | |
1602 | int in_other_hash = 0; | |
1603 | int in_hash = 0; | |
1604 | int match = 0; | |
1605 | ||
1606 | if (all) { | |
1607 | /* | |
1608 | * Only the filter_hash affects all records. | |
1609 | * Update if the record is not in the notrace hash. | |
1610 | */ | |
b848914c | 1611 | if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) |
ed926f9b SR |
1612 | match = 1; |
1613 | } else { | |
06a51d93 SR |
1614 | in_hash = !!ftrace_lookup_ip(hash, rec->ip); |
1615 | in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip); | |
ed926f9b SR |
1616 | |
1617 | /* | |
1618 | * | |
1619 | */ | |
1620 | if (filter_hash && in_hash && !in_other_hash) | |
1621 | match = 1; | |
1622 | else if (!filter_hash && in_hash && | |
06a51d93 | 1623 | (in_other_hash || ftrace_hash_empty(other_hash))) |
ed926f9b SR |
1624 | match = 1; |
1625 | } | |
1626 | if (!match) | |
1627 | continue; | |
1628 | ||
1629 | if (inc) { | |
1630 | rec->flags++; | |
1631 | if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == FTRACE_REF_MAX)) | |
1632 | return; | |
08f6fba5 SR |
1633 | /* |
1634 | * If any ops wants regs saved for this function | |
1635 | * then all ops will get saved regs. | |
1636 | */ | |
1637 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) | |
1638 | rec->flags |= FTRACE_FL_REGS; | |
ed926f9b SR |
1639 | } else { |
1640 | if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == 0)) | |
1641 | return; | |
1642 | rec->flags--; | |
1643 | } | |
1644 | count++; | |
1645 | /* Shortcut, if we handled all records, we are done. */ | |
1646 | if (!all && count == hash->count) | |
1647 | return; | |
1648 | } while_for_each_ftrace_rec(); | |
1649 | } | |
1650 | ||
1651 | static void ftrace_hash_rec_disable(struct ftrace_ops *ops, | |
1652 | int filter_hash) | |
1653 | { | |
1654 | __ftrace_hash_rec_update(ops, filter_hash, 0); | |
1655 | } | |
1656 | ||
1657 | static void ftrace_hash_rec_enable(struct ftrace_ops *ops, | |
1658 | int filter_hash) | |
1659 | { | |
1660 | __ftrace_hash_rec_update(ops, filter_hash, 1); | |
1661 | } | |
1662 | ||
b17e8a37 SR |
1663 | static void print_ip_ins(const char *fmt, unsigned char *p) |
1664 | { | |
1665 | int i; | |
1666 | ||
1667 | printk(KERN_CONT "%s", fmt); | |
1668 | ||
1669 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
1670 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
1671 | } | |
1672 | ||
c88fd863 SR |
1673 | /** |
1674 | * ftrace_bug - report and shutdown function tracer | |
1675 | * @failed: The failed type (EFAULT, EINVAL, EPERM) | |
1676 | * @ip: The address that failed | |
1677 | * | |
1678 | * The arch code that enables or disables the function tracing | |
1679 | * can call ftrace_bug() when it has detected a problem in | |
1680 | * modifying the code. @failed should be one of either: | |
1681 | * EFAULT - if the problem happens on reading the @ip address | |
1682 | * EINVAL - if what is read at @ip is not what was expected | |
1683 | * EPERM - if the problem happens on writting to the @ip address | |
1684 | */ | |
1685 | void ftrace_bug(int failed, unsigned long ip) | |
b17e8a37 SR |
1686 | { |
1687 | switch (failed) { | |
1688 | case -EFAULT: | |
1689 | FTRACE_WARN_ON_ONCE(1); | |
1690 | pr_info("ftrace faulted on modifying "); | |
1691 | print_ip_sym(ip); | |
1692 | break; | |
1693 | case -EINVAL: | |
1694 | FTRACE_WARN_ON_ONCE(1); | |
1695 | pr_info("ftrace failed to modify "); | |
1696 | print_ip_sym(ip); | |
b17e8a37 | 1697 | print_ip_ins(" actual: ", (unsigned char *)ip); |
b17e8a37 SR |
1698 | printk(KERN_CONT "\n"); |
1699 | break; | |
1700 | case -EPERM: | |
1701 | FTRACE_WARN_ON_ONCE(1); | |
1702 | pr_info("ftrace faulted on writing "); | |
1703 | print_ip_sym(ip); | |
1704 | break; | |
1705 | default: | |
1706 | FTRACE_WARN_ON_ONCE(1); | |
1707 | pr_info("ftrace faulted on unknown error "); | |
1708 | print_ip_sym(ip); | |
1709 | } | |
1710 | } | |
1711 | ||
c88fd863 | 1712 | static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update) |
5072c59f | 1713 | { |
64fbcd16 | 1714 | unsigned long flag = 0UL; |
e7d3737e | 1715 | |
982c350b | 1716 | /* |
30fb6aa7 | 1717 | * If we are updating calls: |
982c350b | 1718 | * |
ed926f9b SR |
1719 | * If the record has a ref count, then we need to enable it |
1720 | * because someone is using it. | |
982c350b | 1721 | * |
ed926f9b SR |
1722 | * Otherwise we make sure its disabled. |
1723 | * | |
30fb6aa7 | 1724 | * If we are disabling calls, then disable all records that |
ed926f9b | 1725 | * are enabled. |
982c350b | 1726 | */ |
c88fd863 | 1727 | if (enable && (rec->flags & ~FTRACE_FL_MASK)) |
ed926f9b | 1728 | flag = FTRACE_FL_ENABLED; |
982c350b | 1729 | |
08f6fba5 SR |
1730 | /* |
1731 | * If enabling and the REGS flag does not match the REGS_EN, then | |
1732 | * do not ignore this record. Set flags to fail the compare against | |
1733 | * ENABLED. | |
1734 | */ | |
1735 | if (flag && | |
1736 | (!(rec->flags & FTRACE_FL_REGS) != !(rec->flags & FTRACE_FL_REGS_EN))) | |
1737 | flag |= FTRACE_FL_REGS; | |
1738 | ||
64fbcd16 XG |
1739 | /* If the state of this record hasn't changed, then do nothing */ |
1740 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
c88fd863 | 1741 | return FTRACE_UPDATE_IGNORE; |
982c350b | 1742 | |
64fbcd16 | 1743 | if (flag) { |
08f6fba5 SR |
1744 | /* Save off if rec is being enabled (for return value) */ |
1745 | flag ^= rec->flags & FTRACE_FL_ENABLED; | |
1746 | ||
1747 | if (update) { | |
c88fd863 | 1748 | rec->flags |= FTRACE_FL_ENABLED; |
08f6fba5 SR |
1749 | if (flag & FTRACE_FL_REGS) { |
1750 | if (rec->flags & FTRACE_FL_REGS) | |
1751 | rec->flags |= FTRACE_FL_REGS_EN; | |
1752 | else | |
1753 | rec->flags &= ~FTRACE_FL_REGS_EN; | |
1754 | } | |
1755 | } | |
1756 | ||
1757 | /* | |
1758 | * If this record is being updated from a nop, then | |
1759 | * return UPDATE_MAKE_CALL. | |
1760 | * Otherwise, if the EN flag is set, then return | |
1761 | * UPDATE_MODIFY_CALL_REGS to tell the caller to convert | |
1762 | * from the non-save regs, to a save regs function. | |
1763 | * Otherwise, | |
1764 | * return UPDATE_MODIFY_CALL to tell the caller to convert | |
1765 | * from the save regs, to a non-save regs function. | |
1766 | */ | |
1767 | if (flag & FTRACE_FL_ENABLED) | |
1768 | return FTRACE_UPDATE_MAKE_CALL; | |
1769 | else if (rec->flags & FTRACE_FL_REGS_EN) | |
1770 | return FTRACE_UPDATE_MODIFY_CALL_REGS; | |
1771 | else | |
1772 | return FTRACE_UPDATE_MODIFY_CALL; | |
c88fd863 SR |
1773 | } |
1774 | ||
08f6fba5 SR |
1775 | if (update) { |
1776 | /* If there's no more users, clear all flags */ | |
1777 | if (!(rec->flags & ~FTRACE_FL_MASK)) | |
1778 | rec->flags = 0; | |
1779 | else | |
1780 | /* Just disable the record (keep REGS state) */ | |
1781 | rec->flags &= ~FTRACE_FL_ENABLED; | |
1782 | } | |
c88fd863 SR |
1783 | |
1784 | return FTRACE_UPDATE_MAKE_NOP; | |
1785 | } | |
1786 | ||
1787 | /** | |
1788 | * ftrace_update_record, set a record that now is tracing or not | |
1789 | * @rec: the record to update | |
1790 | * @enable: set to 1 if the record is tracing, zero to force disable | |
1791 | * | |
1792 | * The records that represent all functions that can be traced need | |
1793 | * to be updated when tracing has been enabled. | |
1794 | */ | |
1795 | int ftrace_update_record(struct dyn_ftrace *rec, int enable) | |
1796 | { | |
1797 | return ftrace_check_record(rec, enable, 1); | |
1798 | } | |
1799 | ||
1800 | /** | |
1801 | * ftrace_test_record, check if the record has been enabled or not | |
1802 | * @rec: the record to test | |
1803 | * @enable: set to 1 to check if enabled, 0 if it is disabled | |
1804 | * | |
1805 | * The arch code may need to test if a record is already set to | |
1806 | * tracing to determine how to modify the function code that it | |
1807 | * represents. | |
1808 | */ | |
1809 | int ftrace_test_record(struct dyn_ftrace *rec, int enable) | |
1810 | { | |
1811 | return ftrace_check_record(rec, enable, 0); | |
1812 | } | |
1813 | ||
1814 | static int | |
1815 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) | |
1816 | { | |
08f6fba5 | 1817 | unsigned long ftrace_old_addr; |
c88fd863 SR |
1818 | unsigned long ftrace_addr; |
1819 | int ret; | |
1820 | ||
c88fd863 SR |
1821 | ret = ftrace_update_record(rec, enable); |
1822 | ||
08f6fba5 SR |
1823 | if (rec->flags & FTRACE_FL_REGS) |
1824 | ftrace_addr = (unsigned long)FTRACE_REGS_ADDR; | |
1825 | else | |
1826 | ftrace_addr = (unsigned long)FTRACE_ADDR; | |
1827 | ||
c88fd863 SR |
1828 | switch (ret) { |
1829 | case FTRACE_UPDATE_IGNORE: | |
1830 | return 0; | |
1831 | ||
1832 | case FTRACE_UPDATE_MAKE_CALL: | |
64fbcd16 | 1833 | return ftrace_make_call(rec, ftrace_addr); |
c88fd863 SR |
1834 | |
1835 | case FTRACE_UPDATE_MAKE_NOP: | |
1836 | return ftrace_make_nop(NULL, rec, ftrace_addr); | |
08f6fba5 SR |
1837 | |
1838 | case FTRACE_UPDATE_MODIFY_CALL_REGS: | |
1839 | case FTRACE_UPDATE_MODIFY_CALL: | |
1840 | if (rec->flags & FTRACE_FL_REGS) | |
1841 | ftrace_old_addr = (unsigned long)FTRACE_ADDR; | |
1842 | else | |
1843 | ftrace_old_addr = (unsigned long)FTRACE_REGS_ADDR; | |
1844 | ||
1845 | return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr); | |
5072c59f SR |
1846 | } |
1847 | ||
c88fd863 | 1848 | return -1; /* unknow ftrace bug */ |
5072c59f SR |
1849 | } |
1850 | ||
e4f5d544 | 1851 | void __weak ftrace_replace_code(int enable) |
3c1720f0 | 1852 | { |
3c1720f0 SR |
1853 | struct dyn_ftrace *rec; |
1854 | struct ftrace_page *pg; | |
6a24a244 | 1855 | int failed; |
3c1720f0 | 1856 | |
45a4a237 SR |
1857 | if (unlikely(ftrace_disabled)) |
1858 | return; | |
1859 | ||
265c831c | 1860 | do_for_each_ftrace_rec(pg, rec) { |
e4f5d544 | 1861 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 1862 | if (failed) { |
3279ba37 SR |
1863 | ftrace_bug(failed, rec->ip); |
1864 | /* Stop processing */ | |
1865 | return; | |
3c1720f0 | 1866 | } |
265c831c | 1867 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
1868 | } |
1869 | ||
c88fd863 SR |
1870 | struct ftrace_rec_iter { |
1871 | struct ftrace_page *pg; | |
1872 | int index; | |
1873 | }; | |
1874 | ||
1875 | /** | |
1876 | * ftrace_rec_iter_start, start up iterating over traced functions | |
1877 | * | |
1878 | * Returns an iterator handle that is used to iterate over all | |
1879 | * the records that represent address locations where functions | |
1880 | * are traced. | |
1881 | * | |
1882 | * May return NULL if no records are available. | |
1883 | */ | |
1884 | struct ftrace_rec_iter *ftrace_rec_iter_start(void) | |
1885 | { | |
1886 | /* | |
1887 | * We only use a single iterator. | |
1888 | * Protected by the ftrace_lock mutex. | |
1889 | */ | |
1890 | static struct ftrace_rec_iter ftrace_rec_iter; | |
1891 | struct ftrace_rec_iter *iter = &ftrace_rec_iter; | |
1892 | ||
1893 | iter->pg = ftrace_pages_start; | |
1894 | iter->index = 0; | |
1895 | ||
1896 | /* Could have empty pages */ | |
1897 | while (iter->pg && !iter->pg->index) | |
1898 | iter->pg = iter->pg->next; | |
1899 | ||
1900 | if (!iter->pg) | |
1901 | return NULL; | |
1902 | ||
1903 | return iter; | |
1904 | } | |
1905 | ||
1906 | /** | |
1907 | * ftrace_rec_iter_next, get the next record to process. | |
1908 | * @iter: The handle to the iterator. | |
1909 | * | |
1910 | * Returns the next iterator after the given iterator @iter. | |
1911 | */ | |
1912 | struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) | |
1913 | { | |
1914 | iter->index++; | |
1915 | ||
1916 | if (iter->index >= iter->pg->index) { | |
1917 | iter->pg = iter->pg->next; | |
1918 | iter->index = 0; | |
1919 | ||
1920 | /* Could have empty pages */ | |
1921 | while (iter->pg && !iter->pg->index) | |
1922 | iter->pg = iter->pg->next; | |
1923 | } | |
1924 | ||
1925 | if (!iter->pg) | |
1926 | return NULL; | |
1927 | ||
1928 | return iter; | |
1929 | } | |
1930 | ||
1931 | /** | |
1932 | * ftrace_rec_iter_record, get the record at the iterator location | |
1933 | * @iter: The current iterator location | |
1934 | * | |
1935 | * Returns the record that the current @iter is at. | |
1936 | */ | |
1937 | struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) | |
1938 | { | |
1939 | return &iter->pg->records[iter->index]; | |
1940 | } | |
1941 | ||
492a7ea5 | 1942 | static int |
31e88909 | 1943 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 SR |
1944 | { |
1945 | unsigned long ip; | |
593eb8a2 | 1946 | int ret; |
3c1720f0 SR |
1947 | |
1948 | ip = rec->ip; | |
1949 | ||
45a4a237 SR |
1950 | if (unlikely(ftrace_disabled)) |
1951 | return 0; | |
1952 | ||
25aac9dc | 1953 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 1954 | if (ret) { |
31e88909 | 1955 | ftrace_bug(ret, ip); |
492a7ea5 | 1956 | return 0; |
37ad5084 | 1957 | } |
492a7ea5 | 1958 | return 1; |
3c1720f0 SR |
1959 | } |
1960 | ||
000ab691 SR |
1961 | /* |
1962 | * archs can override this function if they must do something | |
1963 | * before the modifying code is performed. | |
1964 | */ | |
1965 | int __weak ftrace_arch_code_modify_prepare(void) | |
1966 | { | |
1967 | return 0; | |
1968 | } | |
1969 | ||
1970 | /* | |
1971 | * archs can override this function if they must do something | |
1972 | * after the modifying code is performed. | |
1973 | */ | |
1974 | int __weak ftrace_arch_code_modify_post_process(void) | |
1975 | { | |
1976 | return 0; | |
1977 | } | |
1978 | ||
8ed3e2cf | 1979 | void ftrace_modify_all_code(int command) |
3d083395 | 1980 | { |
8ed3e2cf | 1981 | if (command & FTRACE_UPDATE_CALLS) |
d61f82d0 | 1982 | ftrace_replace_code(1); |
8ed3e2cf | 1983 | else if (command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
1984 | ftrace_replace_code(0); |
1985 | ||
8ed3e2cf | 1986 | if (command & FTRACE_UPDATE_TRACE_FUNC) |
d61f82d0 SR |
1987 | ftrace_update_ftrace_func(ftrace_trace_function); |
1988 | ||
8ed3e2cf | 1989 | if (command & FTRACE_START_FUNC_RET) |
5a45cfe1 | 1990 | ftrace_enable_ftrace_graph_caller(); |
8ed3e2cf | 1991 | else if (command & FTRACE_STOP_FUNC_RET) |
5a45cfe1 | 1992 | ftrace_disable_ftrace_graph_caller(); |
8ed3e2cf SR |
1993 | } |
1994 | ||
1995 | static int __ftrace_modify_code(void *data) | |
1996 | { | |
1997 | int *command = data; | |
1998 | ||
1999 | ftrace_modify_all_code(*command); | |
5a45cfe1 | 2000 | |
d61f82d0 | 2001 | return 0; |
3d083395 SR |
2002 | } |
2003 | ||
c88fd863 SR |
2004 | /** |
2005 | * ftrace_run_stop_machine, go back to the stop machine method | |
2006 | * @command: The command to tell ftrace what to do | |
2007 | * | |
2008 | * If an arch needs to fall back to the stop machine method, the | |
2009 | * it can call this function. | |
2010 | */ | |
2011 | void ftrace_run_stop_machine(int command) | |
2012 | { | |
2013 | stop_machine(__ftrace_modify_code, &command, NULL); | |
2014 | } | |
2015 | ||
2016 | /** | |
2017 | * arch_ftrace_update_code, modify the code to trace or not trace | |
2018 | * @command: The command that needs to be done | |
2019 | * | |
2020 | * Archs can override this function if it does not need to | |
2021 | * run stop_machine() to modify code. | |
2022 | */ | |
2023 | void __weak arch_ftrace_update_code(int command) | |
2024 | { | |
2025 | ftrace_run_stop_machine(command); | |
2026 | } | |
2027 | ||
e309b41d | 2028 | static void ftrace_run_update_code(int command) |
3d083395 | 2029 | { |
000ab691 SR |
2030 | int ret; |
2031 | ||
2032 | ret = ftrace_arch_code_modify_prepare(); | |
2033 | FTRACE_WARN_ON(ret); | |
2034 | if (ret) | |
2035 | return; | |
c88fd863 SR |
2036 | /* |
2037 | * Do not call function tracer while we update the code. | |
2038 | * We are in stop machine. | |
2039 | */ | |
2040 | function_trace_stop++; | |
000ab691 | 2041 | |
c88fd863 SR |
2042 | /* |
2043 | * By default we use stop_machine() to modify the code. | |
2044 | * But archs can do what ever they want as long as it | |
2045 | * is safe. The stop_machine() is the safest, but also | |
2046 | * produces the most overhead. | |
2047 | */ | |
2048 | arch_ftrace_update_code(command); | |
2049 | ||
c88fd863 | 2050 | function_trace_stop--; |
000ab691 SR |
2051 | |
2052 | ret = ftrace_arch_code_modify_post_process(); | |
2053 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
2054 | } |
2055 | ||
d61f82d0 | 2056 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 2057 | static int ftrace_start_up; |
b848914c | 2058 | static int global_start_up; |
df4fc315 SR |
2059 | |
2060 | static void ftrace_startup_enable(int command) | |
2061 | { | |
2062 | if (saved_ftrace_func != ftrace_trace_function) { | |
2063 | saved_ftrace_func = ftrace_trace_function; | |
2064 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2065 | } | |
2066 | ||
2067 | if (!command || !ftrace_enabled) | |
2068 | return; | |
2069 | ||
2070 | ftrace_run_update_code(command); | |
2071 | } | |
d61f82d0 | 2072 | |
a1cd6173 | 2073 | static int ftrace_startup(struct ftrace_ops *ops, int command) |
3d083395 | 2074 | { |
b848914c SR |
2075 | bool hash_enable = true; |
2076 | ||
4eebcc81 | 2077 | if (unlikely(ftrace_disabled)) |
a1cd6173 | 2078 | return -ENODEV; |
4eebcc81 | 2079 | |
60a7ecf4 | 2080 | ftrace_start_up++; |
30fb6aa7 | 2081 | command |= FTRACE_UPDATE_CALLS; |
d61f82d0 | 2082 | |
b848914c SR |
2083 | /* ops marked global share the filter hashes */ |
2084 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { | |
2085 | ops = &global_ops; | |
2086 | /* Don't update hash if global is already set */ | |
2087 | if (global_start_up) | |
2088 | hash_enable = false; | |
2089 | global_start_up++; | |
2090 | } | |
2091 | ||
ed926f9b | 2092 | ops->flags |= FTRACE_OPS_FL_ENABLED; |
b848914c | 2093 | if (hash_enable) |
ed926f9b SR |
2094 | ftrace_hash_rec_enable(ops, 1); |
2095 | ||
df4fc315 | 2096 | ftrace_startup_enable(command); |
a1cd6173 SR |
2097 | |
2098 | return 0; | |
3d083395 SR |
2099 | } |
2100 | ||
bd69c30b | 2101 | static void ftrace_shutdown(struct ftrace_ops *ops, int command) |
3d083395 | 2102 | { |
b848914c SR |
2103 | bool hash_disable = true; |
2104 | ||
4eebcc81 SR |
2105 | if (unlikely(ftrace_disabled)) |
2106 | return; | |
2107 | ||
60a7ecf4 | 2108 | ftrace_start_up--; |
9ea1a153 FW |
2109 | /* |
2110 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
2111 | * critical but the ftrace_call callers may be never nopped again after | |
2112 | * further ftrace uses. | |
2113 | */ | |
2114 | WARN_ON_ONCE(ftrace_start_up < 0); | |
2115 | ||
b848914c SR |
2116 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { |
2117 | ops = &global_ops; | |
2118 | global_start_up--; | |
2119 | WARN_ON_ONCE(global_start_up < 0); | |
2120 | /* Don't update hash if global still has users */ | |
2121 | if (global_start_up) { | |
2122 | WARN_ON_ONCE(!ftrace_start_up); | |
2123 | hash_disable = false; | |
2124 | } | |
2125 | } | |
2126 | ||
2127 | if (hash_disable) | |
ed926f9b SR |
2128 | ftrace_hash_rec_disable(ops, 1); |
2129 | ||
b848914c | 2130 | if (ops != &global_ops || !global_start_up) |
ed926f9b | 2131 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
b848914c | 2132 | |
30fb6aa7 | 2133 | command |= FTRACE_UPDATE_CALLS; |
3d083395 | 2134 | |
d61f82d0 SR |
2135 | if (saved_ftrace_func != ftrace_trace_function) { |
2136 | saved_ftrace_func = ftrace_trace_function; | |
2137 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2138 | } | |
3d083395 | 2139 | |
d61f82d0 | 2140 | if (!command || !ftrace_enabled) |
e6ea44e9 | 2141 | return; |
d61f82d0 SR |
2142 | |
2143 | ftrace_run_update_code(command); | |
3d083395 SR |
2144 | } |
2145 | ||
e309b41d | 2146 | static void ftrace_startup_sysctl(void) |
b0fc494f | 2147 | { |
4eebcc81 SR |
2148 | if (unlikely(ftrace_disabled)) |
2149 | return; | |
2150 | ||
d61f82d0 SR |
2151 | /* Force update next time */ |
2152 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
2153 | /* ftrace_start_up is true if we want ftrace running */ |
2154 | if (ftrace_start_up) | |
30fb6aa7 | 2155 | ftrace_run_update_code(FTRACE_UPDATE_CALLS); |
b0fc494f SR |
2156 | } |
2157 | ||
e309b41d | 2158 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 2159 | { |
4eebcc81 SR |
2160 | if (unlikely(ftrace_disabled)) |
2161 | return; | |
2162 | ||
60a7ecf4 SR |
2163 | /* ftrace_start_up is true if ftrace is running */ |
2164 | if (ftrace_start_up) | |
79e406d7 | 2165 | ftrace_run_update_code(FTRACE_DISABLE_CALLS); |
b0fc494f SR |
2166 | } |
2167 | ||
3d083395 SR |
2168 | static cycle_t ftrace_update_time; |
2169 | static unsigned long ftrace_update_cnt; | |
2170 | unsigned long ftrace_update_tot_cnt; | |
2171 | ||
8c4f3c3f | 2172 | static inline int ops_traces_mod(struct ftrace_ops *ops) |
f7bc8b61 | 2173 | { |
8c4f3c3f SRRH |
2174 | /* |
2175 | * Filter_hash being empty will default to trace module. | |
2176 | * But notrace hash requires a test of individual module functions. | |
2177 | */ | |
2178 | return ftrace_hash_empty(ops->filter_hash) && | |
2179 | ftrace_hash_empty(ops->notrace_hash); | |
2180 | } | |
2181 | ||
2182 | /* | |
2183 | * Check if the current ops references the record. | |
2184 | * | |
2185 | * If the ops traces all functions, then it was already accounted for. | |
2186 | * If the ops does not trace the current record function, skip it. | |
2187 | * If the ops ignores the function via notrace filter, skip it. | |
2188 | */ | |
2189 | static inline bool | |
2190 | ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec) | |
2191 | { | |
2192 | /* If ops isn't enabled, ignore it */ | |
2193 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
2194 | return 0; | |
2195 | ||
2196 | /* If ops traces all mods, we already accounted for it */ | |
2197 | if (ops_traces_mod(ops)) | |
2198 | return 0; | |
2199 | ||
2200 | /* The function must be in the filter */ | |
2201 | if (!ftrace_hash_empty(ops->filter_hash) && | |
2202 | !ftrace_lookup_ip(ops->filter_hash, rec->ip)) | |
2203 | return 0; | |
f7bc8b61 | 2204 | |
8c4f3c3f SRRH |
2205 | /* If in notrace hash, we ignore it too */ |
2206 | if (ftrace_lookup_ip(ops->notrace_hash, rec->ip)) | |
2207 | return 0; | |
2208 | ||
2209 | return 1; | |
2210 | } | |
2211 | ||
2212 | static int referenced_filters(struct dyn_ftrace *rec) | |
2213 | { | |
2214 | struct ftrace_ops *ops; | |
2215 | int cnt = 0; | |
2216 | ||
2217 | for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) { | |
2218 | if (ops_references_rec(ops, rec)) | |
2219 | cnt++; | |
2220 | } | |
2221 | ||
2222 | return cnt; | |
f7bc8b61 SR |
2223 | } |
2224 | ||
31e88909 | 2225 | static int ftrace_update_code(struct module *mod) |
3d083395 | 2226 | { |
85ae32ae | 2227 | struct ftrace_page *pg; |
e94142a6 | 2228 | struct dyn_ftrace *p; |
f22f9a89 | 2229 | cycle_t start, stop; |
f7bc8b61 | 2230 | unsigned long ref = 0; |
8c4f3c3f | 2231 | bool test = false; |
85ae32ae | 2232 | int i; |
f7bc8b61 SR |
2233 | |
2234 | /* | |
2235 | * When adding a module, we need to check if tracers are | |
2236 | * currently enabled and if they are set to trace all functions. | |
2237 | * If they are, we need to enable the module functions as well | |
2238 | * as update the reference counts for those function records. | |
2239 | */ | |
2240 | if (mod) { | |
2241 | struct ftrace_ops *ops; | |
2242 | ||
2243 | for (ops = ftrace_ops_list; | |
2244 | ops != &ftrace_list_end; ops = ops->next) { | |
8c4f3c3f SRRH |
2245 | if (ops->flags & FTRACE_OPS_FL_ENABLED) { |
2246 | if (ops_traces_mod(ops)) | |
2247 | ref++; | |
2248 | else | |
2249 | test = true; | |
2250 | } | |
f7bc8b61 SR |
2251 | } |
2252 | } | |
3d083395 | 2253 | |
750ed1a4 | 2254 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
2255 | ftrace_update_cnt = 0; |
2256 | ||
85ae32ae | 2257 | for (pg = ftrace_new_pgs; pg; pg = pg->next) { |
3d083395 | 2258 | |
85ae32ae | 2259 | for (i = 0; i < pg->index; i++) { |
8c4f3c3f SRRH |
2260 | int cnt = ref; |
2261 | ||
85ae32ae SR |
2262 | /* If something went wrong, bail without enabling anything */ |
2263 | if (unlikely(ftrace_disabled)) | |
2264 | return -1; | |
f22f9a89 | 2265 | |
85ae32ae | 2266 | p = &pg->records[i]; |
8c4f3c3f SRRH |
2267 | if (test) |
2268 | cnt += referenced_filters(p); | |
2269 | p->flags = cnt; | |
f22f9a89 | 2270 | |
85ae32ae SR |
2271 | /* |
2272 | * Do the initial record conversion from mcount jump | |
2273 | * to the NOP instructions. | |
2274 | */ | |
2275 | if (!ftrace_code_disable(mod, p)) | |
2276 | break; | |
5cb084bb | 2277 | |
85ae32ae | 2278 | ftrace_update_cnt++; |
5cb084bb | 2279 | |
85ae32ae SR |
2280 | /* |
2281 | * If the tracing is enabled, go ahead and enable the record. | |
2282 | * | |
2283 | * The reason not to enable the record immediatelly is the | |
2284 | * inherent check of ftrace_make_nop/ftrace_make_call for | |
2285 | * correct previous instructions. Making first the NOP | |
2286 | * conversion puts the module to the correct state, thus | |
2287 | * passing the ftrace_make_call check. | |
2288 | */ | |
8c4f3c3f | 2289 | if (ftrace_start_up && cnt) { |
85ae32ae SR |
2290 | int failed = __ftrace_replace_code(p, 1); |
2291 | if (failed) | |
2292 | ftrace_bug(failed, p->ip); | |
2293 | } | |
5cb084bb | 2294 | } |
3d083395 SR |
2295 | } |
2296 | ||
85ae32ae SR |
2297 | ftrace_new_pgs = NULL; |
2298 | ||
750ed1a4 | 2299 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
2300 | ftrace_update_time = stop - start; |
2301 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
2302 | ||
16444a8a ACM |
2303 | return 0; |
2304 | } | |
2305 | ||
a7900875 | 2306 | static int ftrace_allocate_records(struct ftrace_page *pg, int count) |
3c1720f0 | 2307 | { |
a7900875 | 2308 | int order; |
3c1720f0 | 2309 | int cnt; |
3c1720f0 | 2310 | |
a7900875 SR |
2311 | if (WARN_ON(!count)) |
2312 | return -EINVAL; | |
2313 | ||
2314 | order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE)); | |
3c1720f0 SR |
2315 | |
2316 | /* | |
a7900875 SR |
2317 | * We want to fill as much as possible. No more than a page |
2318 | * may be empty. | |
3c1720f0 | 2319 | */ |
a7900875 SR |
2320 | while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE) |
2321 | order--; | |
3c1720f0 | 2322 | |
a7900875 SR |
2323 | again: |
2324 | pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order); | |
3c1720f0 | 2325 | |
a7900875 SR |
2326 | if (!pg->records) { |
2327 | /* if we can't allocate this size, try something smaller */ | |
2328 | if (!order) | |
2329 | return -ENOMEM; | |
2330 | order >>= 1; | |
2331 | goto again; | |
2332 | } | |
3c1720f0 | 2333 | |
a7900875 SR |
2334 | cnt = (PAGE_SIZE << order) / ENTRY_SIZE; |
2335 | pg->size = cnt; | |
3c1720f0 | 2336 | |
a7900875 SR |
2337 | if (cnt > count) |
2338 | cnt = count; | |
2339 | ||
2340 | return cnt; | |
2341 | } | |
2342 | ||
2343 | static struct ftrace_page * | |
2344 | ftrace_allocate_pages(unsigned long num_to_init) | |
2345 | { | |
2346 | struct ftrace_page *start_pg; | |
2347 | struct ftrace_page *pg; | |
2348 | int order; | |
2349 | int cnt; | |
2350 | ||
2351 | if (!num_to_init) | |
2352 | return 0; | |
2353 | ||
2354 | start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL); | |
2355 | if (!pg) | |
2356 | return NULL; | |
2357 | ||
2358 | /* | |
2359 | * Try to allocate as much as possible in one continues | |
2360 | * location that fills in all of the space. We want to | |
2361 | * waste as little space as possible. | |
2362 | */ | |
2363 | for (;;) { | |
2364 | cnt = ftrace_allocate_records(pg, num_to_init); | |
2365 | if (cnt < 0) | |
2366 | goto free_pages; | |
2367 | ||
2368 | num_to_init -= cnt; | |
2369 | if (!num_to_init) | |
3c1720f0 SR |
2370 | break; |
2371 | ||
a7900875 SR |
2372 | pg->next = kzalloc(sizeof(*pg), GFP_KERNEL); |
2373 | if (!pg->next) | |
2374 | goto free_pages; | |
2375 | ||
3c1720f0 SR |
2376 | pg = pg->next; |
2377 | } | |
2378 | ||
a7900875 SR |
2379 | return start_pg; |
2380 | ||
2381 | free_pages: | |
2382 | while (start_pg) { | |
2383 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); | |
2384 | free_pages((unsigned long)pg->records, order); | |
2385 | start_pg = pg->next; | |
2386 | kfree(pg); | |
2387 | pg = start_pg; | |
2388 | } | |
2389 | pr_info("ftrace: FAILED to allocate memory for functions\n"); | |
2390 | return NULL; | |
2391 | } | |
2392 | ||
2393 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) | |
2394 | { | |
2395 | int cnt; | |
2396 | ||
2397 | if (!num_to_init) { | |
2398 | pr_info("ftrace: No functions to be traced?\n"); | |
2399 | return -1; | |
2400 | } | |
2401 | ||
2402 | cnt = num_to_init / ENTRIES_PER_PAGE; | |
2403 | pr_info("ftrace: allocating %ld entries in %d pages\n", | |
2404 | num_to_init, cnt + 1); | |
2405 | ||
3c1720f0 SR |
2406 | return 0; |
2407 | } | |
2408 | ||
5072c59f SR |
2409 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ |
2410 | ||
2411 | struct ftrace_iterator { | |
98c4fd04 | 2412 | loff_t pos; |
4aeb6967 SR |
2413 | loff_t func_pos; |
2414 | struct ftrace_page *pg; | |
2415 | struct dyn_ftrace *func; | |
2416 | struct ftrace_func_probe *probe; | |
2417 | struct trace_parser parser; | |
1cf41dd7 | 2418 | struct ftrace_hash *hash; |
33dc9b12 | 2419 | struct ftrace_ops *ops; |
4aeb6967 SR |
2420 | int hidx; |
2421 | int idx; | |
2422 | unsigned flags; | |
5072c59f SR |
2423 | }; |
2424 | ||
8fc0c701 | 2425 | static void * |
4aeb6967 | 2426 | t_hash_next(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
2427 | { |
2428 | struct ftrace_iterator *iter = m->private; | |
4aeb6967 | 2429 | struct hlist_node *hnd = NULL; |
8fc0c701 SR |
2430 | struct hlist_head *hhd; |
2431 | ||
8fc0c701 | 2432 | (*pos)++; |
98c4fd04 | 2433 | iter->pos = *pos; |
8fc0c701 | 2434 | |
4aeb6967 SR |
2435 | if (iter->probe) |
2436 | hnd = &iter->probe->node; | |
8fc0c701 SR |
2437 | retry: |
2438 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
2439 | return NULL; | |
2440 | ||
2441 | hhd = &ftrace_func_hash[iter->hidx]; | |
2442 | ||
2443 | if (hlist_empty(hhd)) { | |
2444 | iter->hidx++; | |
2445 | hnd = NULL; | |
2446 | goto retry; | |
2447 | } | |
2448 | ||
2449 | if (!hnd) | |
2450 | hnd = hhd->first; | |
2451 | else { | |
2452 | hnd = hnd->next; | |
2453 | if (!hnd) { | |
2454 | iter->hidx++; | |
2455 | goto retry; | |
2456 | } | |
2457 | } | |
2458 | ||
4aeb6967 SR |
2459 | if (WARN_ON_ONCE(!hnd)) |
2460 | return NULL; | |
2461 | ||
2462 | iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node); | |
2463 | ||
2464 | return iter; | |
8fc0c701 SR |
2465 | } |
2466 | ||
2467 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
2468 | { | |
2469 | struct ftrace_iterator *iter = m->private; | |
2470 | void *p = NULL; | |
d82d6244 LZ |
2471 | loff_t l; |
2472 | ||
69a3083c SR |
2473 | if (!(iter->flags & FTRACE_ITER_DO_HASH)) |
2474 | return NULL; | |
2475 | ||
2bccfffd SR |
2476 | if (iter->func_pos > *pos) |
2477 | return NULL; | |
8fc0c701 | 2478 | |
d82d6244 | 2479 | iter->hidx = 0; |
2bccfffd | 2480 | for (l = 0; l <= (*pos - iter->func_pos); ) { |
4aeb6967 | 2481 | p = t_hash_next(m, &l); |
d82d6244 LZ |
2482 | if (!p) |
2483 | break; | |
2484 | } | |
4aeb6967 SR |
2485 | if (!p) |
2486 | return NULL; | |
2487 | ||
98c4fd04 SR |
2488 | /* Only set this if we have an item */ |
2489 | iter->flags |= FTRACE_ITER_HASH; | |
2490 | ||
4aeb6967 | 2491 | return iter; |
8fc0c701 SR |
2492 | } |
2493 | ||
4aeb6967 SR |
2494 | static int |
2495 | t_hash_show(struct seq_file *m, struct ftrace_iterator *iter) | |
8fc0c701 | 2496 | { |
b6887d79 | 2497 | struct ftrace_func_probe *rec; |
8fc0c701 | 2498 | |
4aeb6967 SR |
2499 | rec = iter->probe; |
2500 | if (WARN_ON_ONCE(!rec)) | |
2501 | return -EIO; | |
8fc0c701 | 2502 | |
809dcf29 SR |
2503 | if (rec->ops->print) |
2504 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
2505 | ||
b375a11a | 2506 | seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func); |
8fc0c701 SR |
2507 | |
2508 | if (rec->data) | |
2509 | seq_printf(m, ":%p", rec->data); | |
2510 | seq_putc(m, '\n'); | |
2511 | ||
2512 | return 0; | |
2513 | } | |
2514 | ||
e309b41d | 2515 | static void * |
5072c59f SR |
2516 | t_next(struct seq_file *m, void *v, loff_t *pos) |
2517 | { | |
2518 | struct ftrace_iterator *iter = m->private; | |
fc13cb0c | 2519 | struct ftrace_ops *ops = iter->ops; |
5072c59f SR |
2520 | struct dyn_ftrace *rec = NULL; |
2521 | ||
45a4a237 SR |
2522 | if (unlikely(ftrace_disabled)) |
2523 | return NULL; | |
2524 | ||
8fc0c701 | 2525 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 2526 | return t_hash_next(m, pos); |
8fc0c701 | 2527 | |
5072c59f | 2528 | (*pos)++; |
1106b699 | 2529 | iter->pos = iter->func_pos = *pos; |
5072c59f | 2530 | |
0c75a3ed | 2531 | if (iter->flags & FTRACE_ITER_PRINTALL) |
57c072c7 | 2532 | return t_hash_start(m, pos); |
0c75a3ed | 2533 | |
5072c59f SR |
2534 | retry: |
2535 | if (iter->idx >= iter->pg->index) { | |
2536 | if (iter->pg->next) { | |
2537 | iter->pg = iter->pg->next; | |
2538 | iter->idx = 0; | |
2539 | goto retry; | |
2540 | } | |
2541 | } else { | |
2542 | rec = &iter->pg->records[iter->idx++]; | |
32082309 | 2543 | if (((iter->flags & FTRACE_ITER_FILTER) && |
f45948e8 | 2544 | !(ftrace_lookup_ip(ops->filter_hash, rec->ip))) || |
0183fb1c | 2545 | |
41c52c0d | 2546 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
647bcd03 SR |
2547 | !ftrace_lookup_ip(ops->notrace_hash, rec->ip)) || |
2548 | ||
2549 | ((iter->flags & FTRACE_ITER_ENABLED) && | |
23ea9c4d | 2550 | !(rec->flags & FTRACE_FL_ENABLED))) { |
647bcd03 | 2551 | |
5072c59f SR |
2552 | rec = NULL; |
2553 | goto retry; | |
2554 | } | |
2555 | } | |
2556 | ||
4aeb6967 | 2557 | if (!rec) |
57c072c7 | 2558 | return t_hash_start(m, pos); |
4aeb6967 SR |
2559 | |
2560 | iter->func = rec; | |
2561 | ||
2562 | return iter; | |
5072c59f SR |
2563 | } |
2564 | ||
98c4fd04 SR |
2565 | static void reset_iter_read(struct ftrace_iterator *iter) |
2566 | { | |
2567 | iter->pos = 0; | |
2568 | iter->func_pos = 0; | |
70f77b3f | 2569 | iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_HASH); |
5072c59f SR |
2570 | } |
2571 | ||
2572 | static void *t_start(struct seq_file *m, loff_t *pos) | |
2573 | { | |
2574 | struct ftrace_iterator *iter = m->private; | |
fc13cb0c | 2575 | struct ftrace_ops *ops = iter->ops; |
5072c59f | 2576 | void *p = NULL; |
694ce0a5 | 2577 | loff_t l; |
5072c59f | 2578 | |
8fc0c701 | 2579 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
2580 | |
2581 | if (unlikely(ftrace_disabled)) | |
2582 | return NULL; | |
2583 | ||
98c4fd04 SR |
2584 | /* |
2585 | * If an lseek was done, then reset and start from beginning. | |
2586 | */ | |
2587 | if (*pos < iter->pos) | |
2588 | reset_iter_read(iter); | |
2589 | ||
0c75a3ed SR |
2590 | /* |
2591 | * For set_ftrace_filter reading, if we have the filter | |
2592 | * off, we can short cut and just print out that all | |
2593 | * functions are enabled. | |
2594 | */ | |
06a51d93 SR |
2595 | if (iter->flags & FTRACE_ITER_FILTER && |
2596 | ftrace_hash_empty(ops->filter_hash)) { | |
0c75a3ed | 2597 | if (*pos > 0) |
8fc0c701 | 2598 | return t_hash_start(m, pos); |
0c75a3ed | 2599 | iter->flags |= FTRACE_ITER_PRINTALL; |
df091625 CW |
2600 | /* reset in case of seek/pread */ |
2601 | iter->flags &= ~FTRACE_ITER_HASH; | |
0c75a3ed SR |
2602 | return iter; |
2603 | } | |
2604 | ||
8fc0c701 SR |
2605 | if (iter->flags & FTRACE_ITER_HASH) |
2606 | return t_hash_start(m, pos); | |
2607 | ||
98c4fd04 SR |
2608 | /* |
2609 | * Unfortunately, we need to restart at ftrace_pages_start | |
2610 | * every time we let go of the ftrace_mutex. This is because | |
2611 | * those pointers can change without the lock. | |
2612 | */ | |
694ce0a5 LZ |
2613 | iter->pg = ftrace_pages_start; |
2614 | iter->idx = 0; | |
2615 | for (l = 0; l <= *pos; ) { | |
2616 | p = t_next(m, p, &l); | |
2617 | if (!p) | |
2618 | break; | |
50cdaf08 | 2619 | } |
5821e1b7 | 2620 | |
69a3083c SR |
2621 | if (!p) |
2622 | return t_hash_start(m, pos); | |
4aeb6967 SR |
2623 | |
2624 | return iter; | |
5072c59f SR |
2625 | } |
2626 | ||
2627 | static void t_stop(struct seq_file *m, void *p) | |
2628 | { | |
8fc0c701 | 2629 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
2630 | } |
2631 | ||
2632 | static int t_show(struct seq_file *m, void *v) | |
2633 | { | |
0c75a3ed | 2634 | struct ftrace_iterator *iter = m->private; |
4aeb6967 | 2635 | struct dyn_ftrace *rec; |
5072c59f | 2636 | |
8fc0c701 | 2637 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 2638 | return t_hash_show(m, iter); |
8fc0c701 | 2639 | |
0c75a3ed SR |
2640 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
2641 | seq_printf(m, "#### all functions enabled ####\n"); | |
2642 | return 0; | |
2643 | } | |
2644 | ||
4aeb6967 SR |
2645 | rec = iter->func; |
2646 | ||
5072c59f SR |
2647 | if (!rec) |
2648 | return 0; | |
2649 | ||
647bcd03 SR |
2650 | seq_printf(m, "%ps", (void *)rec->ip); |
2651 | if (iter->flags & FTRACE_ITER_ENABLED) | |
08f6fba5 SR |
2652 | seq_printf(m, " (%ld)%s", |
2653 | rec->flags & ~FTRACE_FL_MASK, | |
2654 | rec->flags & FTRACE_FL_REGS ? " R" : ""); | |
647bcd03 | 2655 | seq_printf(m, "\n"); |
5072c59f SR |
2656 | |
2657 | return 0; | |
2658 | } | |
2659 | ||
88e9d34c | 2660 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
2661 | .start = t_start, |
2662 | .next = t_next, | |
2663 | .stop = t_stop, | |
2664 | .show = t_show, | |
2665 | }; | |
2666 | ||
e309b41d | 2667 | static int |
5072c59f SR |
2668 | ftrace_avail_open(struct inode *inode, struct file *file) |
2669 | { | |
2670 | struct ftrace_iterator *iter; | |
5072c59f | 2671 | |
4eebcc81 SR |
2672 | if (unlikely(ftrace_disabled)) |
2673 | return -ENODEV; | |
2674 | ||
50e18b94 JO |
2675 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
2676 | if (iter) { | |
2677 | iter->pg = ftrace_pages_start; | |
2678 | iter->ops = &global_ops; | |
4bf39a94 | 2679 | } |
5072c59f | 2680 | |
50e18b94 | 2681 | return iter ? 0 : -ENOMEM; |
5072c59f SR |
2682 | } |
2683 | ||
647bcd03 SR |
2684 | static int |
2685 | ftrace_enabled_open(struct inode *inode, struct file *file) | |
2686 | { | |
2687 | struct ftrace_iterator *iter; | |
647bcd03 SR |
2688 | |
2689 | if (unlikely(ftrace_disabled)) | |
2690 | return -ENODEV; | |
2691 | ||
50e18b94 JO |
2692 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
2693 | if (iter) { | |
2694 | iter->pg = ftrace_pages_start; | |
2695 | iter->flags = FTRACE_ITER_ENABLED; | |
2696 | iter->ops = &global_ops; | |
647bcd03 SR |
2697 | } |
2698 | ||
50e18b94 | 2699 | return iter ? 0 : -ENOMEM; |
647bcd03 SR |
2700 | } |
2701 | ||
1cf41dd7 | 2702 | static void ftrace_filter_reset(struct ftrace_hash *hash) |
5072c59f | 2703 | { |
52baf119 | 2704 | mutex_lock(&ftrace_lock); |
1cf41dd7 | 2705 | ftrace_hash_clear(hash); |
52baf119 | 2706 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
2707 | } |
2708 | ||
fc13cb0c SR |
2709 | /** |
2710 | * ftrace_regex_open - initialize function tracer filter files | |
2711 | * @ops: The ftrace_ops that hold the hash filters | |
2712 | * @flag: The type of filter to process | |
2713 | * @inode: The inode, usually passed in to your open routine | |
2714 | * @file: The file, usually passed in to your open routine | |
2715 | * | |
2716 | * ftrace_regex_open() initializes the filter files for the | |
2717 | * @ops. Depending on @flag it may process the filter hash or | |
2718 | * the notrace hash of @ops. With this called from the open | |
2719 | * routine, you can use ftrace_filter_write() for the write | |
2720 | * routine if @flag has FTRACE_ITER_FILTER set, or | |
2721 | * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set. | |
7f49ef69 | 2722 | * ftrace_filter_lseek() should be used as the lseek routine, and |
fc13cb0c SR |
2723 | * release must call ftrace_regex_release(). |
2724 | */ | |
2725 | int | |
f45948e8 | 2726 | ftrace_regex_open(struct ftrace_ops *ops, int flag, |
1cf41dd7 | 2727 | struct inode *inode, struct file *file) |
5072c59f SR |
2728 | { |
2729 | struct ftrace_iterator *iter; | |
f45948e8 | 2730 | struct ftrace_hash *hash; |
5072c59f SR |
2731 | int ret = 0; |
2732 | ||
f04f24fb MH |
2733 | ftrace_ops_init(ops); |
2734 | ||
4eebcc81 SR |
2735 | if (unlikely(ftrace_disabled)) |
2736 | return -ENODEV; | |
2737 | ||
5072c59f SR |
2738 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
2739 | if (!iter) | |
2740 | return -ENOMEM; | |
2741 | ||
689fd8b6 | 2742 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) { |
2743 | kfree(iter); | |
2744 | return -ENOMEM; | |
2745 | } | |
2746 | ||
3f2367ba MH |
2747 | iter->ops = ops; |
2748 | iter->flags = flag; | |
2749 | ||
2750 | mutex_lock(&ops->regex_lock); | |
2751 | ||
f45948e8 SR |
2752 | if (flag & FTRACE_ITER_NOTRACE) |
2753 | hash = ops->notrace_hash; | |
2754 | else | |
2755 | hash = ops->filter_hash; | |
2756 | ||
33dc9b12 | 2757 | if (file->f_mode & FMODE_WRITE) { |
33dc9b12 | 2758 | iter->hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash); |
33dc9b12 SR |
2759 | if (!iter->hash) { |
2760 | trace_parser_put(&iter->parser); | |
2761 | kfree(iter); | |
3f2367ba MH |
2762 | ret = -ENOMEM; |
2763 | goto out_unlock; | |
33dc9b12 SR |
2764 | } |
2765 | } | |
1cf41dd7 | 2766 | |
5072c59f | 2767 | if ((file->f_mode & FMODE_WRITE) && |
8650ae32 | 2768 | (file->f_flags & O_TRUNC)) |
33dc9b12 | 2769 | ftrace_filter_reset(iter->hash); |
5072c59f SR |
2770 | |
2771 | if (file->f_mode & FMODE_READ) { | |
2772 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
2773 | |
2774 | ret = seq_open(file, &show_ftrace_seq_ops); | |
2775 | if (!ret) { | |
2776 | struct seq_file *m = file->private_data; | |
2777 | m->private = iter; | |
79fe249c | 2778 | } else { |
33dc9b12 SR |
2779 | /* Failed */ |
2780 | free_ftrace_hash(iter->hash); | |
79fe249c | 2781 | trace_parser_put(&iter->parser); |
5072c59f | 2782 | kfree(iter); |
79fe249c | 2783 | } |
5072c59f SR |
2784 | } else |
2785 | file->private_data = iter; | |
3f2367ba MH |
2786 | |
2787 | out_unlock: | |
f04f24fb | 2788 | mutex_unlock(&ops->regex_lock); |
5072c59f SR |
2789 | |
2790 | return ret; | |
2791 | } | |
2792 | ||
41c52c0d SR |
2793 | static int |
2794 | ftrace_filter_open(struct inode *inode, struct file *file) | |
2795 | { | |
69a3083c SR |
2796 | return ftrace_regex_open(&global_ops, |
2797 | FTRACE_ITER_FILTER | FTRACE_ITER_DO_HASH, | |
2798 | inode, file); | |
41c52c0d SR |
2799 | } |
2800 | ||
2801 | static int | |
2802 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
2803 | { | |
f45948e8 | 2804 | return ftrace_regex_open(&global_ops, FTRACE_ITER_NOTRACE, |
1cf41dd7 | 2805 | inode, file); |
41c52c0d SR |
2806 | } |
2807 | ||
64e7c440 | 2808 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 2809 | { |
9f4801e3 | 2810 | int matched = 0; |
751e9983 | 2811 | int slen; |
9f4801e3 | 2812 | |
9f4801e3 SR |
2813 | switch (type) { |
2814 | case MATCH_FULL: | |
2815 | if (strcmp(str, regex) == 0) | |
2816 | matched = 1; | |
2817 | break; | |
2818 | case MATCH_FRONT_ONLY: | |
2819 | if (strncmp(str, regex, len) == 0) | |
2820 | matched = 1; | |
2821 | break; | |
2822 | case MATCH_MIDDLE_ONLY: | |
2823 | if (strstr(str, regex)) | |
2824 | matched = 1; | |
2825 | break; | |
2826 | case MATCH_END_ONLY: | |
751e9983 LZ |
2827 | slen = strlen(str); |
2828 | if (slen >= len && memcmp(str + slen - len, regex, len) == 0) | |
9f4801e3 SR |
2829 | matched = 1; |
2830 | break; | |
2831 | } | |
2832 | ||
2833 | return matched; | |
2834 | } | |
2835 | ||
b448c4e3 | 2836 | static int |
1cf41dd7 | 2837 | enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not) |
996e87be | 2838 | { |
b448c4e3 | 2839 | struct ftrace_func_entry *entry; |
b448c4e3 SR |
2840 | int ret = 0; |
2841 | ||
1cf41dd7 SR |
2842 | entry = ftrace_lookup_ip(hash, rec->ip); |
2843 | if (not) { | |
2844 | /* Do nothing if it doesn't exist */ | |
2845 | if (!entry) | |
2846 | return 0; | |
b448c4e3 | 2847 | |
33dc9b12 | 2848 | free_hash_entry(hash, entry); |
1cf41dd7 SR |
2849 | } else { |
2850 | /* Do nothing if it exists */ | |
2851 | if (entry) | |
2852 | return 0; | |
b448c4e3 | 2853 | |
1cf41dd7 | 2854 | ret = add_hash_entry(hash, rec->ip); |
b448c4e3 SR |
2855 | } |
2856 | return ret; | |
996e87be SR |
2857 | } |
2858 | ||
64e7c440 | 2859 | static int |
b9df92d2 SR |
2860 | ftrace_match_record(struct dyn_ftrace *rec, char *mod, |
2861 | char *regex, int len, int type) | |
64e7c440 SR |
2862 | { |
2863 | char str[KSYM_SYMBOL_LEN]; | |
b9df92d2 SR |
2864 | char *modname; |
2865 | ||
2866 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
2867 | ||
2868 | if (mod) { | |
2869 | /* module lookup requires matching the module */ | |
2870 | if (!modname || strcmp(modname, mod)) | |
2871 | return 0; | |
2872 | ||
2873 | /* blank search means to match all funcs in the mod */ | |
2874 | if (!len) | |
2875 | return 1; | |
2876 | } | |
64e7c440 | 2877 | |
64e7c440 SR |
2878 | return ftrace_match(str, regex, len, type); |
2879 | } | |
2880 | ||
1cf41dd7 SR |
2881 | static int |
2882 | match_records(struct ftrace_hash *hash, char *buff, | |
2883 | int len, char *mod, int not) | |
9f4801e3 | 2884 | { |
b9df92d2 | 2885 | unsigned search_len = 0; |
9f4801e3 SR |
2886 | struct ftrace_page *pg; |
2887 | struct dyn_ftrace *rec; | |
b9df92d2 SR |
2888 | int type = MATCH_FULL; |
2889 | char *search = buff; | |
311d16da | 2890 | int found = 0; |
b448c4e3 | 2891 | int ret; |
9f4801e3 | 2892 | |
b9df92d2 SR |
2893 | if (len) { |
2894 | type = filter_parse_regex(buff, len, &search, ¬); | |
2895 | search_len = strlen(search); | |
2896 | } | |
9f4801e3 | 2897 | |
52baf119 | 2898 | mutex_lock(&ftrace_lock); |
265c831c | 2899 | |
b9df92d2 SR |
2900 | if (unlikely(ftrace_disabled)) |
2901 | goto out_unlock; | |
9f4801e3 | 2902 | |
265c831c | 2903 | do_for_each_ftrace_rec(pg, rec) { |
b9df92d2 | 2904 | if (ftrace_match_record(rec, mod, search, search_len, type)) { |
1cf41dd7 | 2905 | ret = enter_record(hash, rec, not); |
b448c4e3 SR |
2906 | if (ret < 0) { |
2907 | found = ret; | |
2908 | goto out_unlock; | |
2909 | } | |
311d16da | 2910 | found = 1; |
265c831c SR |
2911 | } |
2912 | } while_for_each_ftrace_rec(); | |
b9df92d2 | 2913 | out_unlock: |
52baf119 | 2914 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
2915 | |
2916 | return found; | |
5072c59f SR |
2917 | } |
2918 | ||
64e7c440 | 2919 | static int |
1cf41dd7 | 2920 | ftrace_match_records(struct ftrace_hash *hash, char *buff, int len) |
64e7c440 | 2921 | { |
1cf41dd7 | 2922 | return match_records(hash, buff, len, NULL, 0); |
64e7c440 SR |
2923 | } |
2924 | ||
1cf41dd7 SR |
2925 | static int |
2926 | ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod) | |
64e7c440 | 2927 | { |
64e7c440 | 2928 | int not = 0; |
6a24a244 | 2929 | |
64e7c440 SR |
2930 | /* blank or '*' mean the same */ |
2931 | if (strcmp(buff, "*") == 0) | |
2932 | buff[0] = 0; | |
2933 | ||
2934 | /* handle the case of 'dont filter this module' */ | |
2935 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
2936 | buff[0] = 0; | |
2937 | not = 1; | |
2938 | } | |
2939 | ||
1cf41dd7 | 2940 | return match_records(hash, buff, strlen(buff), mod, not); |
64e7c440 SR |
2941 | } |
2942 | ||
f6180773 SR |
2943 | /* |
2944 | * We register the module command as a template to show others how | |
2945 | * to register the a command as well. | |
2946 | */ | |
2947 | ||
2948 | static int | |
43dd61c9 SR |
2949 | ftrace_mod_callback(struct ftrace_hash *hash, |
2950 | char *func, char *cmd, char *param, int enable) | |
f6180773 SR |
2951 | { |
2952 | char *mod; | |
b448c4e3 | 2953 | int ret = -EINVAL; |
f6180773 SR |
2954 | |
2955 | /* | |
2956 | * cmd == 'mod' because we only registered this func | |
2957 | * for the 'mod' ftrace_func_command. | |
2958 | * But if you register one func with multiple commands, | |
2959 | * you can tell which command was used by the cmd | |
2960 | * parameter. | |
2961 | */ | |
2962 | ||
2963 | /* we must have a module name */ | |
2964 | if (!param) | |
b448c4e3 | 2965 | return ret; |
f6180773 SR |
2966 | |
2967 | mod = strsep(¶m, ":"); | |
2968 | if (!strlen(mod)) | |
b448c4e3 | 2969 | return ret; |
f6180773 | 2970 | |
1cf41dd7 | 2971 | ret = ftrace_match_module_records(hash, func, mod); |
b448c4e3 SR |
2972 | if (!ret) |
2973 | ret = -EINVAL; | |
2974 | if (ret < 0) | |
2975 | return ret; | |
2976 | ||
2977 | return 0; | |
f6180773 SR |
2978 | } |
2979 | ||
2980 | static struct ftrace_func_command ftrace_mod_cmd = { | |
2981 | .name = "mod", | |
2982 | .func = ftrace_mod_callback, | |
2983 | }; | |
2984 | ||
2985 | static int __init ftrace_mod_cmd_init(void) | |
2986 | { | |
2987 | return register_ftrace_command(&ftrace_mod_cmd); | |
2988 | } | |
6f415672 | 2989 | core_initcall(ftrace_mod_cmd_init); |
f6180773 | 2990 | |
2f5f6ad9 | 2991 | static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 2992 | struct ftrace_ops *op, struct pt_regs *pt_regs) |
59df055f | 2993 | { |
b6887d79 | 2994 | struct ftrace_func_probe *entry; |
59df055f | 2995 | struct hlist_head *hhd; |
59df055f | 2996 | unsigned long key; |
59df055f SR |
2997 | |
2998 | key = hash_long(ip, FTRACE_HASH_BITS); | |
2999 | ||
3000 | hhd = &ftrace_func_hash[key]; | |
3001 | ||
3002 | if (hlist_empty(hhd)) | |
3003 | return; | |
3004 | ||
3005 | /* | |
3006 | * Disable preemption for these calls to prevent a RCU grace | |
3007 | * period. This syncs the hash iteration and freeing of items | |
3008 | * on the hash. rcu_read_lock is too dangerous here. | |
3009 | */ | |
5168ae50 | 3010 | preempt_disable_notrace(); |
1bb539ca | 3011 | hlist_for_each_entry_rcu_notrace(entry, hhd, node) { |
59df055f SR |
3012 | if (entry->ip == ip) |
3013 | entry->ops->func(ip, parent_ip, &entry->data); | |
3014 | } | |
5168ae50 | 3015 | preempt_enable_notrace(); |
59df055f SR |
3016 | } |
3017 | ||
b6887d79 | 3018 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 3019 | { |
fb9fb015 | 3020 | .func = function_trace_probe_call, |
f04f24fb MH |
3021 | .flags = FTRACE_OPS_FL_INITIALIZED, |
3022 | INIT_REGEX_LOCK(trace_probe_ops) | |
59df055f SR |
3023 | }; |
3024 | ||
b6887d79 | 3025 | static int ftrace_probe_registered; |
59df055f | 3026 | |
b6887d79 | 3027 | static void __enable_ftrace_function_probe(void) |
59df055f | 3028 | { |
b848914c | 3029 | int ret; |
59df055f SR |
3030 | int i; |
3031 | ||
19dd603e SRRH |
3032 | if (ftrace_probe_registered) { |
3033 | /* still need to update the function call sites */ | |
3034 | if (ftrace_enabled) | |
3035 | ftrace_run_update_code(FTRACE_UPDATE_CALLS); | |
59df055f | 3036 | return; |
19dd603e | 3037 | } |
59df055f SR |
3038 | |
3039 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
3040 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
3041 | if (hhd->first) | |
3042 | break; | |
3043 | } | |
3044 | /* Nothing registered? */ | |
3045 | if (i == FTRACE_FUNC_HASHSIZE) | |
3046 | return; | |
3047 | ||
b848914c SR |
3048 | ret = __register_ftrace_function(&trace_probe_ops); |
3049 | if (!ret) | |
a1cd6173 | 3050 | ret = ftrace_startup(&trace_probe_ops, 0); |
b848914c | 3051 | |
b6887d79 | 3052 | ftrace_probe_registered = 1; |
59df055f SR |
3053 | } |
3054 | ||
b6887d79 | 3055 | static void __disable_ftrace_function_probe(void) |
59df055f | 3056 | { |
b848914c | 3057 | int ret; |
59df055f SR |
3058 | int i; |
3059 | ||
b6887d79 | 3060 | if (!ftrace_probe_registered) |
59df055f SR |
3061 | return; |
3062 | ||
3063 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
3064 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
3065 | if (hhd->first) | |
3066 | return; | |
3067 | } | |
3068 | ||
3069 | /* no more funcs left */ | |
b848914c SR |
3070 | ret = __unregister_ftrace_function(&trace_probe_ops); |
3071 | if (!ret) | |
3072 | ftrace_shutdown(&trace_probe_ops, 0); | |
3073 | ||
b6887d79 | 3074 | ftrace_probe_registered = 0; |
59df055f SR |
3075 | } |
3076 | ||
3077 | ||
7818b388 | 3078 | static void ftrace_free_entry(struct ftrace_func_probe *entry) |
59df055f | 3079 | { |
59df055f | 3080 | if (entry->ops->free) |
e67efb93 | 3081 | entry->ops->free(entry->ops, entry->ip, &entry->data); |
59df055f SR |
3082 | kfree(entry); |
3083 | } | |
3084 | ||
59df055f | 3085 | int |
b6887d79 | 3086 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3087 | void *data) |
3088 | { | |
b6887d79 | 3089 | struct ftrace_func_probe *entry; |
e1df4cb6 SRRH |
3090 | struct ftrace_hash **orig_hash = &trace_probe_ops.filter_hash; |
3091 | struct ftrace_hash *hash; | |
59df055f SR |
3092 | struct ftrace_page *pg; |
3093 | struct dyn_ftrace *rec; | |
59df055f | 3094 | int type, len, not; |
6a24a244 | 3095 | unsigned long key; |
59df055f SR |
3096 | int count = 0; |
3097 | char *search; | |
e1df4cb6 | 3098 | int ret; |
59df055f | 3099 | |
3f6fe06d | 3100 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
3101 | len = strlen(search); |
3102 | ||
b6887d79 | 3103 | /* we do not support '!' for function probes */ |
59df055f SR |
3104 | if (WARN_ON(not)) |
3105 | return -EINVAL; | |
3106 | ||
3f2367ba | 3107 | mutex_lock(&trace_probe_ops.regex_lock); |
59df055f | 3108 | |
e1df4cb6 SRRH |
3109 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); |
3110 | if (!hash) { | |
3111 | count = -ENOMEM; | |
5ae0bf59 | 3112 | goto out; |
e1df4cb6 SRRH |
3113 | } |
3114 | ||
3115 | if (unlikely(ftrace_disabled)) { | |
3116 | count = -ENODEV; | |
5ae0bf59 | 3117 | goto out; |
e1df4cb6 | 3118 | } |
59df055f | 3119 | |
5ae0bf59 SRRH |
3120 | mutex_lock(&ftrace_lock); |
3121 | ||
45a4a237 | 3122 | do_for_each_ftrace_rec(pg, rec) { |
59df055f | 3123 | |
b9df92d2 | 3124 | if (!ftrace_match_record(rec, NULL, search, len, type)) |
59df055f SR |
3125 | continue; |
3126 | ||
3127 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
3128 | if (!entry) { | |
b6887d79 | 3129 | /* If we did not process any, then return error */ |
59df055f SR |
3130 | if (!count) |
3131 | count = -ENOMEM; | |
3132 | goto out_unlock; | |
3133 | } | |
3134 | ||
3135 | count++; | |
3136 | ||
3137 | entry->data = data; | |
3138 | ||
3139 | /* | |
3140 | * The caller might want to do something special | |
3141 | * for each function we find. We call the callback | |
3142 | * to give the caller an opportunity to do so. | |
3143 | */ | |
e67efb93 SRRH |
3144 | if (ops->init) { |
3145 | if (ops->init(ops, rec->ip, &entry->data) < 0) { | |
59df055f SR |
3146 | /* caller does not like this func */ |
3147 | kfree(entry); | |
3148 | continue; | |
3149 | } | |
3150 | } | |
3151 | ||
e1df4cb6 SRRH |
3152 | ret = enter_record(hash, rec, 0); |
3153 | if (ret < 0) { | |
3154 | kfree(entry); | |
3155 | count = ret; | |
3156 | goto out_unlock; | |
3157 | } | |
3158 | ||
59df055f SR |
3159 | entry->ops = ops; |
3160 | entry->ip = rec->ip; | |
3161 | ||
3162 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
3163 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
3164 | ||
3165 | } while_for_each_ftrace_rec(); | |
e1df4cb6 SRRH |
3166 | |
3167 | ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash); | |
3168 | if (ret < 0) | |
3169 | count = ret; | |
3170 | ||
b6887d79 | 3171 | __enable_ftrace_function_probe(); |
59df055f SR |
3172 | |
3173 | out_unlock: | |
5ae0bf59 SRRH |
3174 | mutex_unlock(&ftrace_lock); |
3175 | out: | |
3f2367ba | 3176 | mutex_unlock(&trace_probe_ops.regex_lock); |
e1df4cb6 | 3177 | free_ftrace_hash(hash); |
59df055f SR |
3178 | |
3179 | return count; | |
3180 | } | |
3181 | ||
3182 | enum { | |
b6887d79 SR |
3183 | PROBE_TEST_FUNC = 1, |
3184 | PROBE_TEST_DATA = 2 | |
59df055f SR |
3185 | }; |
3186 | ||
3187 | static void | |
b6887d79 | 3188 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3189 | void *data, int flags) |
3190 | { | |
e1df4cb6 | 3191 | struct ftrace_func_entry *rec_entry; |
b6887d79 | 3192 | struct ftrace_func_probe *entry; |
7818b388 | 3193 | struct ftrace_func_probe *p; |
e1df4cb6 | 3194 | struct ftrace_hash **orig_hash = &trace_probe_ops.filter_hash; |
7818b388 | 3195 | struct list_head free_list; |
e1df4cb6 | 3196 | struct ftrace_hash *hash; |
b67bfe0d | 3197 | struct hlist_node *tmp; |
59df055f SR |
3198 | char str[KSYM_SYMBOL_LEN]; |
3199 | int type = MATCH_FULL; | |
3200 | int i, len = 0; | |
3201 | char *search; | |
3202 | ||
b36461da | 3203 | if (glob && (strcmp(glob, "*") == 0 || !strlen(glob))) |
59df055f | 3204 | glob = NULL; |
b36461da | 3205 | else if (glob) { |
59df055f SR |
3206 | int not; |
3207 | ||
3f6fe06d | 3208 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
3209 | len = strlen(search); |
3210 | ||
b6887d79 | 3211 | /* we do not support '!' for function probes */ |
59df055f SR |
3212 | if (WARN_ON(not)) |
3213 | return; | |
3214 | } | |
3215 | ||
3f2367ba | 3216 | mutex_lock(&trace_probe_ops.regex_lock); |
e1df4cb6 SRRH |
3217 | |
3218 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
3219 | if (!hash) | |
3220 | /* Hmm, should report this somehow */ | |
3221 | goto out_unlock; | |
3222 | ||
7818b388 SRRH |
3223 | INIT_LIST_HEAD(&free_list); |
3224 | ||
59df055f SR |
3225 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { |
3226 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
3227 | ||
b67bfe0d | 3228 | hlist_for_each_entry_safe(entry, tmp, hhd, node) { |
59df055f SR |
3229 | |
3230 | /* break up if statements for readability */ | |
b6887d79 | 3231 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
3232 | continue; |
3233 | ||
b6887d79 | 3234 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
3235 | continue; |
3236 | ||
3237 | /* do this last, since it is the most expensive */ | |
3238 | if (glob) { | |
3239 | kallsyms_lookup(entry->ip, NULL, NULL, | |
3240 | NULL, str); | |
3241 | if (!ftrace_match(str, glob, len, type)) | |
3242 | continue; | |
3243 | } | |
3244 | ||
e1df4cb6 SRRH |
3245 | rec_entry = ftrace_lookup_ip(hash, entry->ip); |
3246 | /* It is possible more than one entry had this ip */ | |
3247 | if (rec_entry) | |
3248 | free_hash_entry(hash, rec_entry); | |
3249 | ||
740466bc | 3250 | hlist_del_rcu(&entry->node); |
7818b388 | 3251 | list_add(&entry->free_list, &free_list); |
59df055f SR |
3252 | } |
3253 | } | |
3f2367ba | 3254 | mutex_lock(&ftrace_lock); |
b6887d79 | 3255 | __disable_ftrace_function_probe(); |
e1df4cb6 SRRH |
3256 | /* |
3257 | * Remove after the disable is called. Otherwise, if the last | |
3258 | * probe is removed, a null hash means *all enabled*. | |
3259 | */ | |
3260 | ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash); | |
7818b388 SRRH |
3261 | synchronize_sched(); |
3262 | list_for_each_entry_safe(entry, p, &free_list, free_list) { | |
3263 | list_del(&entry->free_list); | |
3264 | ftrace_free_entry(entry); | |
3265 | } | |
3f2367ba | 3266 | mutex_unlock(&ftrace_lock); |
7818b388 | 3267 | |
e1df4cb6 | 3268 | out_unlock: |
3f2367ba | 3269 | mutex_unlock(&trace_probe_ops.regex_lock); |
e1df4cb6 | 3270 | free_ftrace_hash(hash); |
59df055f SR |
3271 | } |
3272 | ||
3273 | void | |
b6887d79 | 3274 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3275 | void *data) |
3276 | { | |
b6887d79 SR |
3277 | __unregister_ftrace_function_probe(glob, ops, data, |
3278 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
3279 | } |
3280 | ||
3281 | void | |
b6887d79 | 3282 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 3283 | { |
b6887d79 | 3284 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
3285 | } |
3286 | ||
b6887d79 | 3287 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 3288 | { |
b6887d79 | 3289 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
3290 | } |
3291 | ||
f6180773 SR |
3292 | static LIST_HEAD(ftrace_commands); |
3293 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
3294 | ||
3295 | int register_ftrace_command(struct ftrace_func_command *cmd) | |
3296 | { | |
3297 | struct ftrace_func_command *p; | |
3298 | int ret = 0; | |
3299 | ||
3300 | mutex_lock(&ftrace_cmd_mutex); | |
3301 | list_for_each_entry(p, &ftrace_commands, list) { | |
3302 | if (strcmp(cmd->name, p->name) == 0) { | |
3303 | ret = -EBUSY; | |
3304 | goto out_unlock; | |
3305 | } | |
3306 | } | |
3307 | list_add(&cmd->list, &ftrace_commands); | |
3308 | out_unlock: | |
3309 | mutex_unlock(&ftrace_cmd_mutex); | |
3310 | ||
3311 | return ret; | |
3312 | } | |
3313 | ||
3314 | int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
3315 | { | |
3316 | struct ftrace_func_command *p, *n; | |
3317 | int ret = -ENODEV; | |
3318 | ||
3319 | mutex_lock(&ftrace_cmd_mutex); | |
3320 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
3321 | if (strcmp(cmd->name, p->name) == 0) { | |
3322 | ret = 0; | |
3323 | list_del_init(&p->list); | |
3324 | goto out_unlock; | |
3325 | } | |
3326 | } | |
3327 | out_unlock: | |
3328 | mutex_unlock(&ftrace_cmd_mutex); | |
3329 | ||
3330 | return ret; | |
3331 | } | |
3332 | ||
33dc9b12 SR |
3333 | static int ftrace_process_regex(struct ftrace_hash *hash, |
3334 | char *buff, int len, int enable) | |
64e7c440 | 3335 | { |
f6180773 | 3336 | char *func, *command, *next = buff; |
6a24a244 | 3337 | struct ftrace_func_command *p; |
0aff1c0c | 3338 | int ret = -EINVAL; |
64e7c440 SR |
3339 | |
3340 | func = strsep(&next, ":"); | |
3341 | ||
3342 | if (!next) { | |
1cf41dd7 | 3343 | ret = ftrace_match_records(hash, func, len); |
b448c4e3 SR |
3344 | if (!ret) |
3345 | ret = -EINVAL; | |
3346 | if (ret < 0) | |
3347 | return ret; | |
3348 | return 0; | |
64e7c440 SR |
3349 | } |
3350 | ||
f6180773 | 3351 | /* command found */ |
64e7c440 SR |
3352 | |
3353 | command = strsep(&next, ":"); | |
3354 | ||
f6180773 SR |
3355 | mutex_lock(&ftrace_cmd_mutex); |
3356 | list_for_each_entry(p, &ftrace_commands, list) { | |
3357 | if (strcmp(p->name, command) == 0) { | |
43dd61c9 | 3358 | ret = p->func(hash, func, command, next, enable); |
f6180773 SR |
3359 | goto out_unlock; |
3360 | } | |
64e7c440 | 3361 | } |
f6180773 SR |
3362 | out_unlock: |
3363 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 3364 | |
f6180773 | 3365 | return ret; |
64e7c440 SR |
3366 | } |
3367 | ||
e309b41d | 3368 | static ssize_t |
41c52c0d SR |
3369 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
3370 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
3371 | { |
3372 | struct ftrace_iterator *iter; | |
689fd8b6 | 3373 | struct trace_parser *parser; |
3374 | ssize_t ret, read; | |
5072c59f | 3375 | |
4ba7978e | 3376 | if (!cnt) |
5072c59f SR |
3377 | return 0; |
3378 | ||
5072c59f SR |
3379 | if (file->f_mode & FMODE_READ) { |
3380 | struct seq_file *m = file->private_data; | |
3381 | iter = m->private; | |
3382 | } else | |
3383 | iter = file->private_data; | |
3384 | ||
f04f24fb | 3385 | if (unlikely(ftrace_disabled)) |
3f2367ba MH |
3386 | return -ENODEV; |
3387 | ||
3388 | /* iter->hash is a local copy, so we don't need regex_lock */ | |
f04f24fb | 3389 | |
689fd8b6 | 3390 | parser = &iter->parser; |
3391 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 3392 | |
4ba7978e | 3393 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 3394 | !trace_parser_cont(parser)) { |
33dc9b12 | 3395 | ret = ftrace_process_regex(iter->hash, parser->buffer, |
689fd8b6 | 3396 | parser->idx, enable); |
313254a9 | 3397 | trace_parser_clear(parser); |
7c088b51 | 3398 | if (ret < 0) |
3f2367ba | 3399 | goto out; |
eda1e328 | 3400 | } |
5072c59f | 3401 | |
5072c59f | 3402 | ret = read; |
3f2367ba | 3403 | out: |
5072c59f SR |
3404 | return ret; |
3405 | } | |
3406 | ||
fc13cb0c | 3407 | ssize_t |
41c52c0d SR |
3408 | ftrace_filter_write(struct file *file, const char __user *ubuf, |
3409 | size_t cnt, loff_t *ppos) | |
3410 | { | |
3411 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
3412 | } | |
3413 | ||
fc13cb0c | 3414 | ssize_t |
41c52c0d SR |
3415 | ftrace_notrace_write(struct file *file, const char __user *ubuf, |
3416 | size_t cnt, loff_t *ppos) | |
3417 | { | |
3418 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
3419 | } | |
3420 | ||
33dc9b12 | 3421 | static int |
647664ea MH |
3422 | ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) |
3423 | { | |
3424 | struct ftrace_func_entry *entry; | |
3425 | ||
3426 | if (!ftrace_location(ip)) | |
3427 | return -EINVAL; | |
3428 | ||
3429 | if (remove) { | |
3430 | entry = ftrace_lookup_ip(hash, ip); | |
3431 | if (!entry) | |
3432 | return -ENOENT; | |
3433 | free_hash_entry(hash, entry); | |
3434 | return 0; | |
3435 | } | |
3436 | ||
3437 | return add_hash_entry(hash, ip); | |
3438 | } | |
3439 | ||
1c80c432 SRRH |
3440 | static void ftrace_ops_update_code(struct ftrace_ops *ops) |
3441 | { | |
3442 | if (ops->flags & FTRACE_OPS_FL_ENABLED && ftrace_enabled) | |
3443 | ftrace_run_update_code(FTRACE_UPDATE_CALLS); | |
3444 | } | |
3445 | ||
647664ea MH |
3446 | static int |
3447 | ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, | |
3448 | unsigned long ip, int remove, int reset, int enable) | |
41c52c0d | 3449 | { |
33dc9b12 | 3450 | struct ftrace_hash **orig_hash; |
f45948e8 | 3451 | struct ftrace_hash *hash; |
33dc9b12 | 3452 | int ret; |
f45948e8 | 3453 | |
936e074b SR |
3454 | /* All global ops uses the global ops filters */ |
3455 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) | |
3456 | ops = &global_ops; | |
3457 | ||
41c52c0d | 3458 | if (unlikely(ftrace_disabled)) |
33dc9b12 | 3459 | return -ENODEV; |
41c52c0d | 3460 | |
3f2367ba MH |
3461 | mutex_lock(&ops->regex_lock); |
3462 | ||
f45948e8 | 3463 | if (enable) |
33dc9b12 | 3464 | orig_hash = &ops->filter_hash; |
f45948e8 | 3465 | else |
33dc9b12 SR |
3466 | orig_hash = &ops->notrace_hash; |
3467 | ||
3468 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
3f2367ba MH |
3469 | if (!hash) { |
3470 | ret = -ENOMEM; | |
3471 | goto out_regex_unlock; | |
3472 | } | |
f45948e8 | 3473 | |
41c52c0d | 3474 | if (reset) |
1cf41dd7 | 3475 | ftrace_filter_reset(hash); |
ac483c44 JO |
3476 | if (buf && !ftrace_match_records(hash, buf, len)) { |
3477 | ret = -EINVAL; | |
3478 | goto out_regex_unlock; | |
3479 | } | |
647664ea MH |
3480 | if (ip) { |
3481 | ret = ftrace_match_addr(hash, ip, remove); | |
3482 | if (ret < 0) | |
3483 | goto out_regex_unlock; | |
3484 | } | |
33dc9b12 SR |
3485 | |
3486 | mutex_lock(&ftrace_lock); | |
41fb61c2 | 3487 | ret = ftrace_hash_move(ops, enable, orig_hash, hash); |
1c80c432 SRRH |
3488 | if (!ret) |
3489 | ftrace_ops_update_code(ops); | |
072126f4 | 3490 | |
33dc9b12 SR |
3491 | mutex_unlock(&ftrace_lock); |
3492 | ||
ac483c44 | 3493 | out_regex_unlock: |
f04f24fb | 3494 | mutex_unlock(&ops->regex_lock); |
33dc9b12 SR |
3495 | |
3496 | free_ftrace_hash(hash); | |
3497 | return ret; | |
41c52c0d SR |
3498 | } |
3499 | ||
647664ea MH |
3500 | static int |
3501 | ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove, | |
3502 | int reset, int enable) | |
3503 | { | |
3504 | return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable); | |
3505 | } | |
3506 | ||
3507 | /** | |
3508 | * ftrace_set_filter_ip - set a function to filter on in ftrace by address | |
3509 | * @ops - the ops to set the filter with | |
3510 | * @ip - the address to add to or remove from the filter. | |
3511 | * @remove - non zero to remove the ip from the filter | |
3512 | * @reset - non zero to reset all filters before applying this filter. | |
3513 | * | |
3514 | * Filters denote which functions should be enabled when tracing is enabled | |
3515 | * If @ip is NULL, it failes to update filter. | |
3516 | */ | |
3517 | int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, | |
3518 | int remove, int reset) | |
3519 | { | |
f04f24fb | 3520 | ftrace_ops_init(ops); |
647664ea MH |
3521 | return ftrace_set_addr(ops, ip, remove, reset, 1); |
3522 | } | |
3523 | EXPORT_SYMBOL_GPL(ftrace_set_filter_ip); | |
3524 | ||
3525 | static int | |
3526 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, | |
3527 | int reset, int enable) | |
3528 | { | |
3529 | return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable); | |
3530 | } | |
3531 | ||
77a2b37d SR |
3532 | /** |
3533 | * ftrace_set_filter - set a function to filter on in ftrace | |
936e074b SR |
3534 | * @ops - the ops to set the filter with |
3535 | * @buf - the string that holds the function filter text. | |
3536 | * @len - the length of the string. | |
3537 | * @reset - non zero to reset all filters before applying this filter. | |
3538 | * | |
3539 | * Filters denote which functions should be enabled when tracing is enabled. | |
3540 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
3541 | */ | |
ac483c44 | 3542 | int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
3543 | int len, int reset) |
3544 | { | |
f04f24fb | 3545 | ftrace_ops_init(ops); |
ac483c44 | 3546 | return ftrace_set_regex(ops, buf, len, reset, 1); |
936e074b SR |
3547 | } |
3548 | EXPORT_SYMBOL_GPL(ftrace_set_filter); | |
3549 | ||
3550 | /** | |
3551 | * ftrace_set_notrace - set a function to not trace in ftrace | |
3552 | * @ops - the ops to set the notrace filter with | |
3553 | * @buf - the string that holds the function notrace text. | |
3554 | * @len - the length of the string. | |
3555 | * @reset - non zero to reset all filters before applying this filter. | |
3556 | * | |
3557 | * Notrace Filters denote which functions should not be enabled when tracing | |
3558 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
3559 | * for tracing. | |
3560 | */ | |
ac483c44 | 3561 | int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
3562 | int len, int reset) |
3563 | { | |
f04f24fb | 3564 | ftrace_ops_init(ops); |
ac483c44 | 3565 | return ftrace_set_regex(ops, buf, len, reset, 0); |
936e074b SR |
3566 | } |
3567 | EXPORT_SYMBOL_GPL(ftrace_set_notrace); | |
3568 | /** | |
3569 | * ftrace_set_filter - set a function to filter on in ftrace | |
3570 | * @ops - the ops to set the filter with | |
77a2b37d SR |
3571 | * @buf - the string that holds the function filter text. |
3572 | * @len - the length of the string. | |
3573 | * @reset - non zero to reset all filters before applying this filter. | |
3574 | * | |
3575 | * Filters denote which functions should be enabled when tracing is enabled. | |
3576 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
3577 | */ | |
936e074b | 3578 | void ftrace_set_global_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 3579 | { |
f45948e8 | 3580 | ftrace_set_regex(&global_ops, buf, len, reset, 1); |
41c52c0d | 3581 | } |
936e074b | 3582 | EXPORT_SYMBOL_GPL(ftrace_set_global_filter); |
4eebcc81 | 3583 | |
41c52c0d SR |
3584 | /** |
3585 | * ftrace_set_notrace - set a function to not trace in ftrace | |
936e074b | 3586 | * @ops - the ops to set the notrace filter with |
41c52c0d SR |
3587 | * @buf - the string that holds the function notrace text. |
3588 | * @len - the length of the string. | |
3589 | * @reset - non zero to reset all filters before applying this filter. | |
3590 | * | |
3591 | * Notrace Filters denote which functions should not be enabled when tracing | |
3592 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
3593 | * for tracing. | |
3594 | */ | |
936e074b | 3595 | void ftrace_set_global_notrace(unsigned char *buf, int len, int reset) |
41c52c0d | 3596 | { |
f45948e8 | 3597 | ftrace_set_regex(&global_ops, buf, len, reset, 0); |
77a2b37d | 3598 | } |
936e074b | 3599 | EXPORT_SYMBOL_GPL(ftrace_set_global_notrace); |
77a2b37d | 3600 | |
2af15d6a SR |
3601 | /* |
3602 | * command line interface to allow users to set filters on boot up. | |
3603 | */ | |
3604 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
3605 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
3606 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
3607 | ||
f1ed7c74 SRRH |
3608 | /* Used by function selftest to not test if filter is set */ |
3609 | bool ftrace_filter_param __initdata; | |
3610 | ||
2af15d6a SR |
3611 | static int __init set_ftrace_notrace(char *str) |
3612 | { | |
f1ed7c74 | 3613 | ftrace_filter_param = true; |
75761cc1 | 3614 | strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
3615 | return 1; |
3616 | } | |
3617 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
3618 | ||
3619 | static int __init set_ftrace_filter(char *str) | |
3620 | { | |
f1ed7c74 | 3621 | ftrace_filter_param = true; |
75761cc1 | 3622 | strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
3623 | return 1; |
3624 | } | |
3625 | __setup("ftrace_filter=", set_ftrace_filter); | |
3626 | ||
369bc18f | 3627 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 3628 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
801c29fd SR |
3629 | static int ftrace_set_func(unsigned long *array, int *idx, char *buffer); |
3630 | ||
369bc18f SA |
3631 | static int __init set_graph_function(char *str) |
3632 | { | |
06f43d66 | 3633 | strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
3634 | return 1; |
3635 | } | |
3636 | __setup("ftrace_graph_filter=", set_graph_function); | |
3637 | ||
3638 | static void __init set_ftrace_early_graph(char *buf) | |
3639 | { | |
3640 | int ret; | |
3641 | char *func; | |
3642 | ||
3643 | while (buf) { | |
3644 | func = strsep(&buf, ","); | |
3645 | /* we allow only one expression at a time */ | |
3646 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, | |
3647 | func); | |
3648 | if (ret) | |
3649 | printk(KERN_DEBUG "ftrace: function %s not " | |
3650 | "traceable\n", func); | |
3651 | } | |
3652 | } | |
3653 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
3654 | ||
2a85a37f SR |
3655 | void __init |
3656 | ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable) | |
2af15d6a SR |
3657 | { |
3658 | char *func; | |
3659 | ||
f04f24fb MH |
3660 | ftrace_ops_init(ops); |
3661 | ||
2af15d6a SR |
3662 | while (buf) { |
3663 | func = strsep(&buf, ","); | |
f45948e8 | 3664 | ftrace_set_regex(ops, func, strlen(func), 0, enable); |
2af15d6a SR |
3665 | } |
3666 | } | |
3667 | ||
3668 | static void __init set_ftrace_early_filters(void) | |
3669 | { | |
3670 | if (ftrace_filter_buf[0]) | |
2a85a37f | 3671 | ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1); |
2af15d6a | 3672 | if (ftrace_notrace_buf[0]) |
2a85a37f | 3673 | ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0); |
369bc18f SA |
3674 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
3675 | if (ftrace_graph_buf[0]) | |
3676 | set_ftrace_early_graph(ftrace_graph_buf); | |
3677 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2af15d6a SR |
3678 | } |
3679 | ||
fc13cb0c | 3680 | int ftrace_regex_release(struct inode *inode, struct file *file) |
5072c59f SR |
3681 | { |
3682 | struct seq_file *m = (struct seq_file *)file->private_data; | |
3683 | struct ftrace_iterator *iter; | |
33dc9b12 | 3684 | struct ftrace_hash **orig_hash; |
689fd8b6 | 3685 | struct trace_parser *parser; |
ed926f9b | 3686 | int filter_hash; |
33dc9b12 | 3687 | int ret; |
5072c59f | 3688 | |
5072c59f SR |
3689 | if (file->f_mode & FMODE_READ) { |
3690 | iter = m->private; | |
5072c59f SR |
3691 | seq_release(inode, file); |
3692 | } else | |
3693 | iter = file->private_data; | |
3694 | ||
689fd8b6 | 3695 | parser = &iter->parser; |
3696 | if (trace_parser_loaded(parser)) { | |
3697 | parser->buffer[parser->idx] = 0; | |
1cf41dd7 | 3698 | ftrace_match_records(iter->hash, parser->buffer, parser->idx); |
5072c59f SR |
3699 | } |
3700 | ||
689fd8b6 | 3701 | trace_parser_put(parser); |
689fd8b6 | 3702 | |
3f2367ba MH |
3703 | mutex_lock(&iter->ops->regex_lock); |
3704 | ||
058e297d | 3705 | if (file->f_mode & FMODE_WRITE) { |
ed926f9b SR |
3706 | filter_hash = !!(iter->flags & FTRACE_ITER_FILTER); |
3707 | ||
3708 | if (filter_hash) | |
33dc9b12 | 3709 | orig_hash = &iter->ops->filter_hash; |
ed926f9b SR |
3710 | else |
3711 | orig_hash = &iter->ops->notrace_hash; | |
33dc9b12 | 3712 | |
058e297d | 3713 | mutex_lock(&ftrace_lock); |
41fb61c2 SR |
3714 | ret = ftrace_hash_move(iter->ops, filter_hash, |
3715 | orig_hash, iter->hash); | |
1c80c432 SRRH |
3716 | if (!ret) |
3717 | ftrace_ops_update_code(iter->ops); | |
41fb61c2 | 3718 | |
058e297d SR |
3719 | mutex_unlock(&ftrace_lock); |
3720 | } | |
3f2367ba MH |
3721 | |
3722 | mutex_unlock(&iter->ops->regex_lock); | |
33dc9b12 SR |
3723 | free_ftrace_hash(iter->hash); |
3724 | kfree(iter); | |
058e297d | 3725 | |
5072c59f SR |
3726 | return 0; |
3727 | } | |
3728 | ||
5e2336a0 | 3729 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
3730 | .open = ftrace_avail_open, |
3731 | .read = seq_read, | |
3732 | .llseek = seq_lseek, | |
3be04b47 | 3733 | .release = seq_release_private, |
5072c59f SR |
3734 | }; |
3735 | ||
647bcd03 SR |
3736 | static const struct file_operations ftrace_enabled_fops = { |
3737 | .open = ftrace_enabled_open, | |
3738 | .read = seq_read, | |
3739 | .llseek = seq_lseek, | |
3740 | .release = seq_release_private, | |
3741 | }; | |
3742 | ||
5e2336a0 | 3743 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 3744 | .open = ftrace_filter_open, |
850a80cf | 3745 | .read = seq_read, |
5072c59f | 3746 | .write = ftrace_filter_write, |
6a76f8c0 | 3747 | .llseek = ftrace_filter_lseek, |
1cf41dd7 | 3748 | .release = ftrace_regex_release, |
5072c59f SR |
3749 | }; |
3750 | ||
5e2336a0 | 3751 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 3752 | .open = ftrace_notrace_open, |
850a80cf | 3753 | .read = seq_read, |
41c52c0d | 3754 | .write = ftrace_notrace_write, |
6a76f8c0 | 3755 | .llseek = ftrace_filter_lseek, |
1cf41dd7 | 3756 | .release = ftrace_regex_release, |
41c52c0d SR |
3757 | }; |
3758 | ||
ea4e2bc4 SR |
3759 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
3760 | ||
3761 | static DEFINE_MUTEX(graph_lock); | |
3762 | ||
3763 | int ftrace_graph_count; | |
c7c6b1fe | 3764 | int ftrace_graph_filter_enabled; |
ea4e2bc4 SR |
3765 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
3766 | ||
3767 | static void * | |
85951842 | 3768 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 3769 | { |
85951842 | 3770 | if (*pos >= ftrace_graph_count) |
ea4e2bc4 | 3771 | return NULL; |
a4ec5e0c | 3772 | return &ftrace_graph_funcs[*pos]; |
85951842 | 3773 | } |
ea4e2bc4 | 3774 | |
85951842 LZ |
3775 | static void * |
3776 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
3777 | { | |
3778 | (*pos)++; | |
3779 | return __g_next(m, pos); | |
ea4e2bc4 SR |
3780 | } |
3781 | ||
3782 | static void *g_start(struct seq_file *m, loff_t *pos) | |
3783 | { | |
ea4e2bc4 SR |
3784 | mutex_lock(&graph_lock); |
3785 | ||
f9349a8f | 3786 | /* Nothing, tell g_show to print all functions are enabled */ |
c7c6b1fe | 3787 | if (!ftrace_graph_filter_enabled && !*pos) |
f9349a8f FW |
3788 | return (void *)1; |
3789 | ||
85951842 | 3790 | return __g_next(m, pos); |
ea4e2bc4 SR |
3791 | } |
3792 | ||
3793 | static void g_stop(struct seq_file *m, void *p) | |
3794 | { | |
3795 | mutex_unlock(&graph_lock); | |
3796 | } | |
3797 | ||
3798 | static int g_show(struct seq_file *m, void *v) | |
3799 | { | |
3800 | unsigned long *ptr = v; | |
ea4e2bc4 SR |
3801 | |
3802 | if (!ptr) | |
3803 | return 0; | |
3804 | ||
f9349a8f FW |
3805 | if (ptr == (unsigned long *)1) { |
3806 | seq_printf(m, "#### all functions enabled ####\n"); | |
3807 | return 0; | |
3808 | } | |
3809 | ||
b375a11a | 3810 | seq_printf(m, "%ps\n", (void *)*ptr); |
ea4e2bc4 SR |
3811 | |
3812 | return 0; | |
3813 | } | |
3814 | ||
88e9d34c | 3815 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
3816 | .start = g_start, |
3817 | .next = g_next, | |
3818 | .stop = g_stop, | |
3819 | .show = g_show, | |
3820 | }; | |
3821 | ||
3822 | static int | |
3823 | ftrace_graph_open(struct inode *inode, struct file *file) | |
3824 | { | |
3825 | int ret = 0; | |
3826 | ||
3827 | if (unlikely(ftrace_disabled)) | |
3828 | return -ENODEV; | |
3829 | ||
3830 | mutex_lock(&graph_lock); | |
3831 | if ((file->f_mode & FMODE_WRITE) && | |
8650ae32 | 3832 | (file->f_flags & O_TRUNC)) { |
c7c6b1fe | 3833 | ftrace_graph_filter_enabled = 0; |
ea4e2bc4 SR |
3834 | ftrace_graph_count = 0; |
3835 | memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); | |
3836 | } | |
a4ec5e0c | 3837 | mutex_unlock(&graph_lock); |
ea4e2bc4 | 3838 | |
a4ec5e0c | 3839 | if (file->f_mode & FMODE_READ) |
ea4e2bc4 | 3840 | ret = seq_open(file, &ftrace_graph_seq_ops); |
ea4e2bc4 SR |
3841 | |
3842 | return ret; | |
3843 | } | |
3844 | ||
87827111 LZ |
3845 | static int |
3846 | ftrace_graph_release(struct inode *inode, struct file *file) | |
3847 | { | |
3848 | if (file->f_mode & FMODE_READ) | |
3849 | seq_release(inode, file); | |
3850 | return 0; | |
3851 | } | |
3852 | ||
ea4e2bc4 | 3853 | static int |
f9349a8f | 3854 | ftrace_set_func(unsigned long *array, int *idx, char *buffer) |
ea4e2bc4 | 3855 | { |
ea4e2bc4 SR |
3856 | struct dyn_ftrace *rec; |
3857 | struct ftrace_page *pg; | |
f9349a8f | 3858 | int search_len; |
c7c6b1fe | 3859 | int fail = 1; |
f9349a8f FW |
3860 | int type, not; |
3861 | char *search; | |
3862 | bool exists; | |
3863 | int i; | |
ea4e2bc4 | 3864 | |
f9349a8f | 3865 | /* decode regex */ |
3f6fe06d | 3866 | type = filter_parse_regex(buffer, strlen(buffer), &search, ¬); |
c7c6b1fe LZ |
3867 | if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS) |
3868 | return -EBUSY; | |
f9349a8f FW |
3869 | |
3870 | search_len = strlen(search); | |
3871 | ||
52baf119 | 3872 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
3873 | |
3874 | if (unlikely(ftrace_disabled)) { | |
3875 | mutex_unlock(&ftrace_lock); | |
3876 | return -ENODEV; | |
3877 | } | |
3878 | ||
265c831c SR |
3879 | do_for_each_ftrace_rec(pg, rec) { |
3880 | ||
b9df92d2 | 3881 | if (ftrace_match_record(rec, NULL, search, search_len, type)) { |
c7c6b1fe | 3882 | /* if it is in the array */ |
f9349a8f | 3883 | exists = false; |
c7c6b1fe | 3884 | for (i = 0; i < *idx; i++) { |
f9349a8f FW |
3885 | if (array[i] == rec->ip) { |
3886 | exists = true; | |
265c831c SR |
3887 | break; |
3888 | } | |
c7c6b1fe LZ |
3889 | } |
3890 | ||
3891 | if (!not) { | |
3892 | fail = 0; | |
3893 | if (!exists) { | |
3894 | array[(*idx)++] = rec->ip; | |
3895 | if (*idx >= FTRACE_GRAPH_MAX_FUNCS) | |
3896 | goto out; | |
3897 | } | |
3898 | } else { | |
3899 | if (exists) { | |
3900 | array[i] = array[--(*idx)]; | |
3901 | array[*idx] = 0; | |
3902 | fail = 0; | |
3903 | } | |
3904 | } | |
ea4e2bc4 | 3905 | } |
265c831c | 3906 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 3907 | out: |
52baf119 | 3908 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 3909 | |
c7c6b1fe LZ |
3910 | if (fail) |
3911 | return -EINVAL; | |
3912 | ||
9f50afcc NK |
3913 | ftrace_graph_filter_enabled = !!(*idx); |
3914 | ||
c7c6b1fe | 3915 | return 0; |
ea4e2bc4 SR |
3916 | } |
3917 | ||
3918 | static ssize_t | |
3919 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
3920 | size_t cnt, loff_t *ppos) | |
3921 | { | |
689fd8b6 | 3922 | struct trace_parser parser; |
4ba7978e | 3923 | ssize_t read, ret; |
ea4e2bc4 | 3924 | |
c7c6b1fe | 3925 | if (!cnt) |
ea4e2bc4 SR |
3926 | return 0; |
3927 | ||
3928 | mutex_lock(&graph_lock); | |
3929 | ||
689fd8b6 | 3930 | if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) { |
3931 | ret = -ENOMEM; | |
1eb90f13 | 3932 | goto out_unlock; |
ea4e2bc4 SR |
3933 | } |
3934 | ||
689fd8b6 | 3935 | read = trace_get_user(&parser, ubuf, cnt, ppos); |
ea4e2bc4 | 3936 | |
4ba7978e | 3937 | if (read >= 0 && trace_parser_loaded((&parser))) { |
689fd8b6 | 3938 | parser.buffer[parser.idx] = 0; |
3939 | ||
3940 | /* we allow only one expression at a time */ | |
a4ec5e0c | 3941 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, |
689fd8b6 | 3942 | parser.buffer); |
ea4e2bc4 | 3943 | if (ret) |
1eb90f13 | 3944 | goto out_free; |
ea4e2bc4 | 3945 | } |
ea4e2bc4 SR |
3946 | |
3947 | ret = read; | |
1eb90f13 LZ |
3948 | |
3949 | out_free: | |
689fd8b6 | 3950 | trace_parser_put(&parser); |
1eb90f13 | 3951 | out_unlock: |
ea4e2bc4 SR |
3952 | mutex_unlock(&graph_lock); |
3953 | ||
3954 | return ret; | |
3955 | } | |
3956 | ||
3957 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
3958 | .open = ftrace_graph_open, |
3959 | .read = seq_read, | |
3960 | .write = ftrace_graph_write, | |
6a76f8c0 | 3961 | .llseek = ftrace_filter_lseek, |
87827111 | 3962 | .release = ftrace_graph_release, |
ea4e2bc4 SR |
3963 | }; |
3964 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
3965 | ||
df4fc315 | 3966 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 3967 | { |
5072c59f | 3968 | |
5452af66 FW |
3969 | trace_create_file("available_filter_functions", 0444, |
3970 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 3971 | |
647bcd03 SR |
3972 | trace_create_file("enabled_functions", 0444, |
3973 | d_tracer, NULL, &ftrace_enabled_fops); | |
3974 | ||
5452af66 FW |
3975 | trace_create_file("set_ftrace_filter", 0644, d_tracer, |
3976 | NULL, &ftrace_filter_fops); | |
41c52c0d | 3977 | |
5452af66 | 3978 | trace_create_file("set_ftrace_notrace", 0644, d_tracer, |
41c52c0d | 3979 | NULL, &ftrace_notrace_fops); |
ad90c0e3 | 3980 | |
ea4e2bc4 | 3981 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5452af66 | 3982 | trace_create_file("set_graph_function", 0444, d_tracer, |
ea4e2bc4 SR |
3983 | NULL, |
3984 | &ftrace_graph_fops); | |
ea4e2bc4 SR |
3985 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
3986 | ||
5072c59f SR |
3987 | return 0; |
3988 | } | |
3989 | ||
9fd49328 | 3990 | static int ftrace_cmp_ips(const void *a, const void *b) |
68950619 | 3991 | { |
9fd49328 SR |
3992 | const unsigned long *ipa = a; |
3993 | const unsigned long *ipb = b; | |
68950619 | 3994 | |
9fd49328 SR |
3995 | if (*ipa > *ipb) |
3996 | return 1; | |
3997 | if (*ipa < *ipb) | |
3998 | return -1; | |
3999 | return 0; | |
4000 | } | |
4001 | ||
4002 | static void ftrace_swap_ips(void *a, void *b, int size) | |
4003 | { | |
4004 | unsigned long *ipa = a; | |
4005 | unsigned long *ipb = b; | |
4006 | unsigned long t; | |
4007 | ||
4008 | t = *ipa; | |
4009 | *ipa = *ipb; | |
4010 | *ipb = t; | |
68950619 SR |
4011 | } |
4012 | ||
5cb084bb | 4013 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 4014 | unsigned long *start, |
68bf21aa SR |
4015 | unsigned long *end) |
4016 | { | |
706c81f8 | 4017 | struct ftrace_page *start_pg; |
a7900875 | 4018 | struct ftrace_page *pg; |
706c81f8 | 4019 | struct dyn_ftrace *rec; |
a7900875 | 4020 | unsigned long count; |
68bf21aa SR |
4021 | unsigned long *p; |
4022 | unsigned long addr; | |
4376cac6 | 4023 | unsigned long flags = 0; /* Shut up gcc */ |
a7900875 SR |
4024 | int ret = -ENOMEM; |
4025 | ||
4026 | count = end - start; | |
4027 | ||
4028 | if (!count) | |
4029 | return 0; | |
4030 | ||
9fd49328 SR |
4031 | sort(start, count, sizeof(*start), |
4032 | ftrace_cmp_ips, ftrace_swap_ips); | |
4033 | ||
706c81f8 SR |
4034 | start_pg = ftrace_allocate_pages(count); |
4035 | if (!start_pg) | |
a7900875 | 4036 | return -ENOMEM; |
68bf21aa | 4037 | |
e6ea44e9 | 4038 | mutex_lock(&ftrace_lock); |
a7900875 | 4039 | |
32082309 SR |
4040 | /* |
4041 | * Core and each module needs their own pages, as | |
4042 | * modules will free them when they are removed. | |
4043 | * Force a new page to be allocated for modules. | |
4044 | */ | |
a7900875 SR |
4045 | if (!mod) { |
4046 | WARN_ON(ftrace_pages || ftrace_pages_start); | |
4047 | /* First initialization */ | |
706c81f8 | 4048 | ftrace_pages = ftrace_pages_start = start_pg; |
a7900875 | 4049 | } else { |
32082309 | 4050 | if (!ftrace_pages) |
a7900875 | 4051 | goto out; |
32082309 | 4052 | |
a7900875 SR |
4053 | if (WARN_ON(ftrace_pages->next)) { |
4054 | /* Hmm, we have free pages? */ | |
4055 | while (ftrace_pages->next) | |
4056 | ftrace_pages = ftrace_pages->next; | |
32082309 | 4057 | } |
a7900875 | 4058 | |
706c81f8 | 4059 | ftrace_pages->next = start_pg; |
32082309 SR |
4060 | } |
4061 | ||
68bf21aa | 4062 | p = start; |
706c81f8 | 4063 | pg = start_pg; |
68bf21aa SR |
4064 | while (p < end) { |
4065 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
4066 | /* |
4067 | * Some architecture linkers will pad between | |
4068 | * the different mcount_loc sections of different | |
4069 | * object files to satisfy alignments. | |
4070 | * Skip any NULL pointers. | |
4071 | */ | |
4072 | if (!addr) | |
4073 | continue; | |
706c81f8 SR |
4074 | |
4075 | if (pg->index == pg->size) { | |
4076 | /* We should have allocated enough */ | |
4077 | if (WARN_ON(!pg->next)) | |
4078 | break; | |
4079 | pg = pg->next; | |
4080 | } | |
4081 | ||
4082 | rec = &pg->records[pg->index++]; | |
4083 | rec->ip = addr; | |
68bf21aa SR |
4084 | } |
4085 | ||
706c81f8 SR |
4086 | /* We should have used all pages */ |
4087 | WARN_ON(pg->next); | |
4088 | ||
4089 | /* Assign the last page to ftrace_pages */ | |
4090 | ftrace_pages = pg; | |
4091 | ||
85ae32ae | 4092 | /* These new locations need to be initialized */ |
706c81f8 | 4093 | ftrace_new_pgs = start_pg; |
85ae32ae | 4094 | |
a4f18ed1 | 4095 | /* |
4376cac6 SR |
4096 | * We only need to disable interrupts on start up |
4097 | * because we are modifying code that an interrupt | |
4098 | * may execute, and the modification is not atomic. | |
4099 | * But for modules, nothing runs the code we modify | |
4100 | * until we are finished with it, and there's no | |
4101 | * reason to cause large interrupt latencies while we do it. | |
a4f18ed1 | 4102 | */ |
4376cac6 SR |
4103 | if (!mod) |
4104 | local_irq_save(flags); | |
31e88909 | 4105 | ftrace_update_code(mod); |
4376cac6 SR |
4106 | if (!mod) |
4107 | local_irq_restore(flags); | |
a7900875 SR |
4108 | ret = 0; |
4109 | out: | |
e6ea44e9 | 4110 | mutex_unlock(&ftrace_lock); |
68bf21aa | 4111 | |
a7900875 | 4112 | return ret; |
68bf21aa SR |
4113 | } |
4114 | ||
93eb677d | 4115 | #ifdef CONFIG_MODULES |
32082309 SR |
4116 | |
4117 | #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next) | |
4118 | ||
e7247a15 | 4119 | void ftrace_release_mod(struct module *mod) |
93eb677d SR |
4120 | { |
4121 | struct dyn_ftrace *rec; | |
32082309 | 4122 | struct ftrace_page **last_pg; |
93eb677d | 4123 | struct ftrace_page *pg; |
a7900875 | 4124 | int order; |
93eb677d | 4125 | |
45a4a237 SR |
4126 | mutex_lock(&ftrace_lock); |
4127 | ||
e7247a15 | 4128 | if (ftrace_disabled) |
45a4a237 | 4129 | goto out_unlock; |
93eb677d | 4130 | |
32082309 SR |
4131 | /* |
4132 | * Each module has its own ftrace_pages, remove | |
4133 | * them from the list. | |
4134 | */ | |
4135 | last_pg = &ftrace_pages_start; | |
4136 | for (pg = ftrace_pages_start; pg; pg = *last_pg) { | |
4137 | rec = &pg->records[0]; | |
e7247a15 | 4138 | if (within_module_core(rec->ip, mod)) { |
93eb677d | 4139 | /* |
32082309 SR |
4140 | * As core pages are first, the first |
4141 | * page should never be a module page. | |
93eb677d | 4142 | */ |
32082309 SR |
4143 | if (WARN_ON(pg == ftrace_pages_start)) |
4144 | goto out_unlock; | |
4145 | ||
4146 | /* Check if we are deleting the last page */ | |
4147 | if (pg == ftrace_pages) | |
4148 | ftrace_pages = next_to_ftrace_page(last_pg); | |
4149 | ||
4150 | *last_pg = pg->next; | |
a7900875 SR |
4151 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
4152 | free_pages((unsigned long)pg->records, order); | |
4153 | kfree(pg); | |
32082309 SR |
4154 | } else |
4155 | last_pg = &pg->next; | |
4156 | } | |
45a4a237 | 4157 | out_unlock: |
93eb677d SR |
4158 | mutex_unlock(&ftrace_lock); |
4159 | } | |
4160 | ||
4161 | static void ftrace_init_module(struct module *mod, | |
4162 | unsigned long *start, unsigned long *end) | |
90d595fe | 4163 | { |
00fd61ae | 4164 | if (ftrace_disabled || start == end) |
fed1939c | 4165 | return; |
5cb084bb | 4166 | ftrace_process_locs(mod, start, end); |
90d595fe SR |
4167 | } |
4168 | ||
8c189ea6 SRRH |
4169 | static int ftrace_module_notify_enter(struct notifier_block *self, |
4170 | unsigned long val, void *data) | |
93eb677d SR |
4171 | { |
4172 | struct module *mod = data; | |
4173 | ||
8c189ea6 | 4174 | if (val == MODULE_STATE_COMING) |
93eb677d SR |
4175 | ftrace_init_module(mod, mod->ftrace_callsites, |
4176 | mod->ftrace_callsites + | |
4177 | mod->num_ftrace_callsites); | |
8c189ea6 SRRH |
4178 | return 0; |
4179 | } | |
4180 | ||
4181 | static int ftrace_module_notify_exit(struct notifier_block *self, | |
4182 | unsigned long val, void *data) | |
4183 | { | |
4184 | struct module *mod = data; | |
4185 | ||
4186 | if (val == MODULE_STATE_GOING) | |
e7247a15 | 4187 | ftrace_release_mod(mod); |
93eb677d SR |
4188 | |
4189 | return 0; | |
4190 | } | |
4191 | #else | |
8c189ea6 SRRH |
4192 | static int ftrace_module_notify_enter(struct notifier_block *self, |
4193 | unsigned long val, void *data) | |
4194 | { | |
4195 | return 0; | |
4196 | } | |
4197 | static int ftrace_module_notify_exit(struct notifier_block *self, | |
4198 | unsigned long val, void *data) | |
93eb677d SR |
4199 | { |
4200 | return 0; | |
4201 | } | |
4202 | #endif /* CONFIG_MODULES */ | |
4203 | ||
8c189ea6 SRRH |
4204 | struct notifier_block ftrace_module_enter_nb = { |
4205 | .notifier_call = ftrace_module_notify_enter, | |
c1bf08ac | 4206 | .priority = INT_MAX, /* Run before anything that can use kprobes */ |
93eb677d SR |
4207 | }; |
4208 | ||
8c189ea6 SRRH |
4209 | struct notifier_block ftrace_module_exit_nb = { |
4210 | .notifier_call = ftrace_module_notify_exit, | |
4211 | .priority = INT_MIN, /* Run after anything that can remove kprobes */ | |
4212 | }; | |
4213 | ||
68bf21aa SR |
4214 | extern unsigned long __start_mcount_loc[]; |
4215 | extern unsigned long __stop_mcount_loc[]; | |
4216 | ||
4217 | void __init ftrace_init(void) | |
4218 | { | |
4219 | unsigned long count, addr, flags; | |
4220 | int ret; | |
4221 | ||
4222 | /* Keep the ftrace pointer to the stub */ | |
4223 | addr = (unsigned long)ftrace_stub; | |
4224 | ||
4225 | local_irq_save(flags); | |
4226 | ftrace_dyn_arch_init(&addr); | |
4227 | local_irq_restore(flags); | |
4228 | ||
4229 | /* ftrace_dyn_arch_init places the return code in addr */ | |
4230 | if (addr) | |
4231 | goto failed; | |
4232 | ||
4233 | count = __stop_mcount_loc - __start_mcount_loc; | |
4234 | ||
4235 | ret = ftrace_dyn_table_alloc(count); | |
4236 | if (ret) | |
4237 | goto failed; | |
4238 | ||
4239 | last_ftrace_enabled = ftrace_enabled = 1; | |
4240 | ||
5cb084bb | 4241 | ret = ftrace_process_locs(NULL, |
31e88909 | 4242 | __start_mcount_loc, |
68bf21aa SR |
4243 | __stop_mcount_loc); |
4244 | ||
8c189ea6 SRRH |
4245 | ret = register_module_notifier(&ftrace_module_enter_nb); |
4246 | if (ret) | |
4247 | pr_warning("Failed to register trace ftrace module enter notifier\n"); | |
4248 | ||
4249 | ret = register_module_notifier(&ftrace_module_exit_nb); | |
24ed0c4b | 4250 | if (ret) |
8c189ea6 | 4251 | pr_warning("Failed to register trace ftrace module exit notifier\n"); |
93eb677d | 4252 | |
2af15d6a SR |
4253 | set_ftrace_early_filters(); |
4254 | ||
68bf21aa SR |
4255 | return; |
4256 | failed: | |
4257 | ftrace_disabled = 1; | |
4258 | } | |
68bf21aa | 4259 | |
3d083395 | 4260 | #else |
0b6e4d56 | 4261 | |
2b499381 | 4262 | static struct ftrace_ops global_ops = { |
bd69c30b | 4263 | .func = ftrace_stub, |
f04f24fb MH |
4264 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, |
4265 | INIT_REGEX_LOCK(global_ops) | |
bd69c30b SR |
4266 | }; |
4267 | ||
0b6e4d56 FW |
4268 | static int __init ftrace_nodyn_init(void) |
4269 | { | |
4270 | ftrace_enabled = 1; | |
4271 | return 0; | |
4272 | } | |
6f415672 | 4273 | core_initcall(ftrace_nodyn_init); |
0b6e4d56 | 4274 | |
df4fc315 SR |
4275 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
4276 | static inline void ftrace_startup_enable(int command) { } | |
5a45cfe1 | 4277 | /* Keep as macros so we do not need to define the commands */ |
3b6cfdb1 SR |
4278 | # define ftrace_startup(ops, command) \ |
4279 | ({ \ | |
4280 | (ops)->flags |= FTRACE_OPS_FL_ENABLED; \ | |
4281 | 0; \ | |
4282 | }) | |
bd69c30b | 4283 | # define ftrace_shutdown(ops, command) do { } while (0) |
c7aafc54 IM |
4284 | # define ftrace_startup_sysctl() do { } while (0) |
4285 | # define ftrace_shutdown_sysctl() do { } while (0) | |
b848914c SR |
4286 | |
4287 | static inline int | |
195a8afc | 4288 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
b848914c SR |
4289 | { |
4290 | return 1; | |
4291 | } | |
4292 | ||
3d083395 SR |
4293 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
4294 | ||
e248491a | 4295 | static void |
2f5f6ad9 | 4296 | ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 4297 | struct ftrace_ops *op, struct pt_regs *regs) |
e248491a | 4298 | { |
e248491a JO |
4299 | if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT))) |
4300 | return; | |
4301 | ||
4302 | /* | |
4303 | * Some of the ops may be dynamically allocated, | |
4304 | * they must be freed after a synchronize_sched(). | |
4305 | */ | |
4306 | preempt_disable_notrace(); | |
4307 | trace_recursion_set(TRACE_CONTROL_BIT); | |
0a016409 | 4308 | do_for_each_ftrace_op(op, ftrace_control_list) { |
395b97a3 SRRH |
4309 | if (!(op->flags & FTRACE_OPS_FL_STUB) && |
4310 | !ftrace_function_local_disabled(op) && | |
195a8afc | 4311 | ftrace_ops_test(op, ip, regs)) |
a1e2e31d | 4312 | op->func(ip, parent_ip, op, regs); |
0a016409 | 4313 | } while_for_each_ftrace_op(op); |
e248491a JO |
4314 | trace_recursion_clear(TRACE_CONTROL_BIT); |
4315 | preempt_enable_notrace(); | |
4316 | } | |
4317 | ||
4318 | static struct ftrace_ops control_ops = { | |
f04f24fb MH |
4319 | .func = ftrace_ops_control_func, |
4320 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, | |
4321 | INIT_REGEX_LOCK(control_ops) | |
e248491a JO |
4322 | }; |
4323 | ||
2f5f6ad9 SR |
4324 | static inline void |
4325 | __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 4326 | struct ftrace_ops *ignored, struct pt_regs *regs) |
b848914c | 4327 | { |
cdbe61bf | 4328 | struct ftrace_ops *op; |
edc15caf | 4329 | int bit; |
b848914c | 4330 | |
ccf3672d SR |
4331 | if (function_trace_stop) |
4332 | return; | |
4333 | ||
edc15caf SR |
4334 | bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX); |
4335 | if (bit < 0) | |
4336 | return; | |
b1cff0ad | 4337 | |
cdbe61bf SR |
4338 | /* |
4339 | * Some of the ops may be dynamically allocated, | |
4340 | * they must be freed after a synchronize_sched(). | |
4341 | */ | |
4342 | preempt_disable_notrace(); | |
0a016409 | 4343 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
195a8afc | 4344 | if (ftrace_ops_test(op, ip, regs)) |
a1e2e31d | 4345 | op->func(ip, parent_ip, op, regs); |
0a016409 | 4346 | } while_for_each_ftrace_op(op); |
cdbe61bf | 4347 | preempt_enable_notrace(); |
edc15caf | 4348 | trace_clear_recursion(bit); |
b848914c SR |
4349 | } |
4350 | ||
2f5f6ad9 SR |
4351 | /* |
4352 | * Some archs only support passing ip and parent_ip. Even though | |
4353 | * the list function ignores the op parameter, we do not want any | |
4354 | * C side effects, where a function is called without the caller | |
4355 | * sending a third parameter. | |
a1e2e31d SR |
4356 | * Archs are to support both the regs and ftrace_ops at the same time. |
4357 | * If they support ftrace_ops, it is assumed they support regs. | |
4358 | * If call backs want to use regs, they must either check for regs | |
06aeaaea MH |
4359 | * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS. |
4360 | * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved. | |
a1e2e31d SR |
4361 | * An architecture can pass partial regs with ftrace_ops and still |
4362 | * set the ARCH_SUPPORT_FTARCE_OPS. | |
2f5f6ad9 SR |
4363 | */ |
4364 | #if ARCH_SUPPORTS_FTRACE_OPS | |
4365 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 4366 | struct ftrace_ops *op, struct pt_regs *regs) |
2f5f6ad9 | 4367 | { |
a1e2e31d | 4368 | __ftrace_ops_list_func(ip, parent_ip, NULL, regs); |
2f5f6ad9 SR |
4369 | } |
4370 | #else | |
4371 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip) | |
4372 | { | |
a1e2e31d | 4373 | __ftrace_ops_list_func(ip, parent_ip, NULL, NULL); |
2f5f6ad9 SR |
4374 | } |
4375 | #endif | |
4376 | ||
e32d8956 | 4377 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
4378 | { |
4379 | struct task_struct *p; | |
e32d8956 | 4380 | int cpu; |
978f3a45 | 4381 | |
e32d8956 SR |
4382 | get_online_cpus(); |
4383 | for_each_online_cpu(cpu) { | |
4384 | p = idle_task(cpu); | |
978f3a45 | 4385 | clear_tsk_trace_trace(p); |
e32d8956 SR |
4386 | } |
4387 | put_online_cpus(); | |
4388 | } | |
978f3a45 | 4389 | |
e32d8956 SR |
4390 | static void set_ftrace_swapper(void) |
4391 | { | |
4392 | struct task_struct *p; | |
4393 | int cpu; | |
4394 | ||
4395 | get_online_cpus(); | |
4396 | for_each_online_cpu(cpu) { | |
4397 | p = idle_task(cpu); | |
4398 | set_tsk_trace_trace(p); | |
4399 | } | |
4400 | put_online_cpus(); | |
978f3a45 SR |
4401 | } |
4402 | ||
e32d8956 SR |
4403 | static void clear_ftrace_pid(struct pid *pid) |
4404 | { | |
4405 | struct task_struct *p; | |
4406 | ||
229c4ef8 | 4407 | rcu_read_lock(); |
e32d8956 SR |
4408 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
4409 | clear_tsk_trace_trace(p); | |
4410 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
4411 | rcu_read_unlock(); |
4412 | ||
e32d8956 SR |
4413 | put_pid(pid); |
4414 | } | |
4415 | ||
4416 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
4417 | { |
4418 | struct task_struct *p; | |
4419 | ||
229c4ef8 | 4420 | rcu_read_lock(); |
978f3a45 SR |
4421 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
4422 | set_tsk_trace_trace(p); | |
4423 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 4424 | rcu_read_unlock(); |
978f3a45 SR |
4425 | } |
4426 | ||
756d17ee | 4427 | static void clear_ftrace_pid_task(struct pid *pid) |
e32d8956 | 4428 | { |
756d17ee | 4429 | if (pid == ftrace_swapper_pid) |
e32d8956 SR |
4430 | clear_ftrace_swapper(); |
4431 | else | |
756d17ee | 4432 | clear_ftrace_pid(pid); |
e32d8956 SR |
4433 | } |
4434 | ||
4435 | static void set_ftrace_pid_task(struct pid *pid) | |
4436 | { | |
4437 | if (pid == ftrace_swapper_pid) | |
4438 | set_ftrace_swapper(); | |
4439 | else | |
4440 | set_ftrace_pid(pid); | |
4441 | } | |
4442 | ||
756d17ee | 4443 | static int ftrace_pid_add(int p) |
df4fc315 | 4444 | { |
978f3a45 | 4445 | struct pid *pid; |
756d17ee | 4446 | struct ftrace_pid *fpid; |
4447 | int ret = -EINVAL; | |
df4fc315 | 4448 | |
756d17ee | 4449 | mutex_lock(&ftrace_lock); |
df4fc315 | 4450 | |
756d17ee | 4451 | if (!p) |
4452 | pid = ftrace_swapper_pid; | |
4453 | else | |
4454 | pid = find_get_pid(p); | |
df4fc315 | 4455 | |
756d17ee | 4456 | if (!pid) |
4457 | goto out; | |
df4fc315 | 4458 | |
756d17ee | 4459 | ret = 0; |
df4fc315 | 4460 | |
756d17ee | 4461 | list_for_each_entry(fpid, &ftrace_pids, list) |
4462 | if (fpid->pid == pid) | |
4463 | goto out_put; | |
978f3a45 | 4464 | |
756d17ee | 4465 | ret = -ENOMEM; |
df4fc315 | 4466 | |
756d17ee | 4467 | fpid = kmalloc(sizeof(*fpid), GFP_KERNEL); |
4468 | if (!fpid) | |
4469 | goto out_put; | |
df4fc315 | 4470 | |
756d17ee | 4471 | list_add(&fpid->list, &ftrace_pids); |
4472 | fpid->pid = pid; | |
0ef8cde5 | 4473 | |
756d17ee | 4474 | set_ftrace_pid_task(pid); |
978f3a45 | 4475 | |
756d17ee | 4476 | ftrace_update_pid_func(); |
4477 | ftrace_startup_enable(0); | |
4478 | ||
4479 | mutex_unlock(&ftrace_lock); | |
4480 | return 0; | |
4481 | ||
4482 | out_put: | |
4483 | if (pid != ftrace_swapper_pid) | |
4484 | put_pid(pid); | |
978f3a45 | 4485 | |
756d17ee | 4486 | out: |
4487 | mutex_unlock(&ftrace_lock); | |
4488 | return ret; | |
4489 | } | |
4490 | ||
4491 | static void ftrace_pid_reset(void) | |
4492 | { | |
4493 | struct ftrace_pid *fpid, *safe; | |
978f3a45 | 4494 | |
756d17ee | 4495 | mutex_lock(&ftrace_lock); |
4496 | list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) { | |
4497 | struct pid *pid = fpid->pid; | |
4498 | ||
4499 | clear_ftrace_pid_task(pid); | |
4500 | ||
4501 | list_del(&fpid->list); | |
4502 | kfree(fpid); | |
df4fc315 SR |
4503 | } |
4504 | ||
df4fc315 SR |
4505 | ftrace_update_pid_func(); |
4506 | ftrace_startup_enable(0); | |
4507 | ||
e6ea44e9 | 4508 | mutex_unlock(&ftrace_lock); |
756d17ee | 4509 | } |
df4fc315 | 4510 | |
756d17ee | 4511 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
4512 | { | |
4513 | mutex_lock(&ftrace_lock); | |
4514 | ||
4515 | if (list_empty(&ftrace_pids) && (!*pos)) | |
4516 | return (void *) 1; | |
4517 | ||
4518 | return seq_list_start(&ftrace_pids, *pos); | |
4519 | } | |
4520 | ||
4521 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
4522 | { | |
4523 | if (v == (void *)1) | |
4524 | return NULL; | |
4525 | ||
4526 | return seq_list_next(v, &ftrace_pids, pos); | |
4527 | } | |
4528 | ||
4529 | static void fpid_stop(struct seq_file *m, void *p) | |
4530 | { | |
4531 | mutex_unlock(&ftrace_lock); | |
4532 | } | |
4533 | ||
4534 | static int fpid_show(struct seq_file *m, void *v) | |
4535 | { | |
4536 | const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list); | |
4537 | ||
4538 | if (v == (void *)1) { | |
4539 | seq_printf(m, "no pid\n"); | |
4540 | return 0; | |
4541 | } | |
4542 | ||
4543 | if (fpid->pid == ftrace_swapper_pid) | |
4544 | seq_printf(m, "swapper tasks\n"); | |
4545 | else | |
4546 | seq_printf(m, "%u\n", pid_vnr(fpid->pid)); | |
4547 | ||
4548 | return 0; | |
4549 | } | |
4550 | ||
4551 | static const struct seq_operations ftrace_pid_sops = { | |
4552 | .start = fpid_start, | |
4553 | .next = fpid_next, | |
4554 | .stop = fpid_stop, | |
4555 | .show = fpid_show, | |
4556 | }; | |
4557 | ||
4558 | static int | |
4559 | ftrace_pid_open(struct inode *inode, struct file *file) | |
4560 | { | |
4561 | int ret = 0; | |
4562 | ||
4563 | if ((file->f_mode & FMODE_WRITE) && | |
4564 | (file->f_flags & O_TRUNC)) | |
4565 | ftrace_pid_reset(); | |
4566 | ||
4567 | if (file->f_mode & FMODE_READ) | |
4568 | ret = seq_open(file, &ftrace_pid_sops); | |
4569 | ||
4570 | return ret; | |
4571 | } | |
4572 | ||
df4fc315 SR |
4573 | static ssize_t |
4574 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
4575 | size_t cnt, loff_t *ppos) | |
4576 | { | |
457dc928 | 4577 | char buf[64], *tmp; |
df4fc315 SR |
4578 | long val; |
4579 | int ret; | |
4580 | ||
4581 | if (cnt >= sizeof(buf)) | |
4582 | return -EINVAL; | |
4583 | ||
4584 | if (copy_from_user(&buf, ubuf, cnt)) | |
4585 | return -EFAULT; | |
4586 | ||
4587 | buf[cnt] = 0; | |
4588 | ||
756d17ee | 4589 | /* |
4590 | * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid" | |
4591 | * to clean the filter quietly. | |
4592 | */ | |
457dc928 IM |
4593 | tmp = strstrip(buf); |
4594 | if (strlen(tmp) == 0) | |
756d17ee | 4595 | return 1; |
4596 | ||
bcd83ea6 | 4597 | ret = kstrtol(tmp, 10, &val); |
df4fc315 SR |
4598 | if (ret < 0) |
4599 | return ret; | |
4600 | ||
756d17ee | 4601 | ret = ftrace_pid_add(val); |
df4fc315 | 4602 | |
756d17ee | 4603 | return ret ? ret : cnt; |
4604 | } | |
df4fc315 | 4605 | |
756d17ee | 4606 | static int |
4607 | ftrace_pid_release(struct inode *inode, struct file *file) | |
4608 | { | |
4609 | if (file->f_mode & FMODE_READ) | |
4610 | seq_release(inode, file); | |
df4fc315 | 4611 | |
756d17ee | 4612 | return 0; |
df4fc315 SR |
4613 | } |
4614 | ||
5e2336a0 | 4615 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 4616 | .open = ftrace_pid_open, |
4617 | .write = ftrace_pid_write, | |
4618 | .read = seq_read, | |
6a76f8c0 | 4619 | .llseek = ftrace_filter_lseek, |
756d17ee | 4620 | .release = ftrace_pid_release, |
df4fc315 SR |
4621 | }; |
4622 | ||
4623 | static __init int ftrace_init_debugfs(void) | |
4624 | { | |
4625 | struct dentry *d_tracer; | |
df4fc315 SR |
4626 | |
4627 | d_tracer = tracing_init_dentry(); | |
4628 | if (!d_tracer) | |
4629 | return 0; | |
4630 | ||
4631 | ftrace_init_dyn_debugfs(d_tracer); | |
4632 | ||
5452af66 FW |
4633 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
4634 | NULL, &ftrace_pid_fops); | |
493762fc SR |
4635 | |
4636 | ftrace_profile_debugfs(d_tracer); | |
4637 | ||
df4fc315 SR |
4638 | return 0; |
4639 | } | |
df4fc315 SR |
4640 | fs_initcall(ftrace_init_debugfs); |
4641 | ||
a2bb6a3d | 4642 | /** |
81adbdc0 | 4643 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
4644 | * |
4645 | * This function should be used by panic code. It stops ftrace | |
4646 | * but in a not so nice way. If you need to simply kill ftrace | |
4647 | * from a non-atomic section, use ftrace_kill. | |
4648 | */ | |
81adbdc0 | 4649 | void ftrace_kill(void) |
a2bb6a3d SR |
4650 | { |
4651 | ftrace_disabled = 1; | |
4652 | ftrace_enabled = 0; | |
a2bb6a3d SR |
4653 | clear_ftrace_function(); |
4654 | } | |
4655 | ||
e0a413f6 SR |
4656 | /** |
4657 | * Test if ftrace is dead or not. | |
4658 | */ | |
4659 | int ftrace_is_dead(void) | |
4660 | { | |
4661 | return ftrace_disabled; | |
4662 | } | |
4663 | ||
16444a8a | 4664 | /** |
3d083395 SR |
4665 | * register_ftrace_function - register a function for profiling |
4666 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 4667 | * |
3d083395 SR |
4668 | * Register a function to be called by all functions in the |
4669 | * kernel. | |
4670 | * | |
4671 | * Note: @ops->func and all the functions it calls must be labeled | |
4672 | * with "notrace", otherwise it will go into a | |
4673 | * recursive loop. | |
16444a8a | 4674 | */ |
3d083395 | 4675 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 4676 | { |
45a4a237 | 4677 | int ret = -1; |
4eebcc81 | 4678 | |
f04f24fb MH |
4679 | ftrace_ops_init(ops); |
4680 | ||
e6ea44e9 | 4681 | mutex_lock(&ftrace_lock); |
e7d3737e | 4682 | |
b0fc494f | 4683 | ret = __register_ftrace_function(ops); |
b848914c | 4684 | if (!ret) |
a1cd6173 | 4685 | ret = ftrace_startup(ops, 0); |
b848914c | 4686 | |
e6ea44e9 | 4687 | mutex_unlock(&ftrace_lock); |
8d240dd8 | 4688 | |
b0fc494f | 4689 | return ret; |
3d083395 | 4690 | } |
cdbe61bf | 4691 | EXPORT_SYMBOL_GPL(register_ftrace_function); |
3d083395 SR |
4692 | |
4693 | /** | |
32632920 | 4694 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
4695 | * @ops - ops structure that holds the function to unregister |
4696 | * | |
4697 | * Unregister a function that was added to be called by ftrace profiling. | |
4698 | */ | |
4699 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
4700 | { | |
4701 | int ret; | |
4702 | ||
e6ea44e9 | 4703 | mutex_lock(&ftrace_lock); |
3d083395 | 4704 | ret = __unregister_ftrace_function(ops); |
b848914c SR |
4705 | if (!ret) |
4706 | ftrace_shutdown(ops, 0); | |
e6ea44e9 | 4707 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
4708 | |
4709 | return ret; | |
4710 | } | |
cdbe61bf | 4711 | EXPORT_SYMBOL_GPL(unregister_ftrace_function); |
b0fc494f | 4712 | |
e309b41d | 4713 | int |
b0fc494f | 4714 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
8d65af78 | 4715 | void __user *buffer, size_t *lenp, |
b0fc494f SR |
4716 | loff_t *ppos) |
4717 | { | |
45a4a237 | 4718 | int ret = -ENODEV; |
4eebcc81 | 4719 | |
e6ea44e9 | 4720 | mutex_lock(&ftrace_lock); |
b0fc494f | 4721 | |
45a4a237 SR |
4722 | if (unlikely(ftrace_disabled)) |
4723 | goto out; | |
4724 | ||
4725 | ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
b0fc494f | 4726 | |
a32c7765 | 4727 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
4728 | goto out; |
4729 | ||
a32c7765 | 4730 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f SR |
4731 | |
4732 | if (ftrace_enabled) { | |
4733 | ||
4734 | ftrace_startup_sysctl(); | |
4735 | ||
4736 | /* we are starting ftrace again */ | |
5000c418 JK |
4737 | if (ftrace_ops_list != &ftrace_list_end) |
4738 | update_ftrace_function(); | |
b0fc494f SR |
4739 | |
4740 | } else { | |
4741 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
4742 | ftrace_trace_function = ftrace_stub; | |
4743 | ||
4744 | ftrace_shutdown_sysctl(); | |
4745 | } | |
4746 | ||
4747 | out: | |
e6ea44e9 | 4748 | mutex_unlock(&ftrace_lock); |
3d083395 | 4749 | return ret; |
16444a8a | 4750 | } |
f17845e5 | 4751 | |
fb52607a | 4752 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 4753 | |
597af815 | 4754 | static int ftrace_graph_active; |
4a2b8dda | 4755 | static struct notifier_block ftrace_suspend_notifier; |
e7d3737e | 4756 | |
e49dc19c SR |
4757 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
4758 | { | |
4759 | return 0; | |
4760 | } | |
4761 | ||
287b6e68 FW |
4762 | /* The callbacks that hook a function */ |
4763 | trace_func_graph_ret_t ftrace_graph_return = | |
4764 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 4765 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
4766 | |
4767 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
4768 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
4769 | { | |
4770 | int i; | |
4771 | int ret = 0; | |
4772 | unsigned long flags; | |
4773 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
4774 | struct task_struct *g, *t; | |
4775 | ||
4776 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
4777 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
4778 | * sizeof(struct ftrace_ret_stack), | |
4779 | GFP_KERNEL); | |
4780 | if (!ret_stack_list[i]) { | |
4781 | start = 0; | |
4782 | end = i; | |
4783 | ret = -ENOMEM; | |
4784 | goto free; | |
4785 | } | |
4786 | } | |
4787 | ||
4788 | read_lock_irqsave(&tasklist_lock, flags); | |
4789 | do_each_thread(g, t) { | |
4790 | if (start == end) { | |
4791 | ret = -EAGAIN; | |
4792 | goto unlock; | |
4793 | } | |
4794 | ||
4795 | if (t->ret_stack == NULL) { | |
380c4b14 | 4796 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 4797 | atomic_set(&t->trace_overrun, 0); |
26c01624 SR |
4798 | t->curr_ret_stack = -1; |
4799 | /* Make sure the tasks see the -1 first: */ | |
4800 | smp_wmb(); | |
4801 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
4802 | } |
4803 | } while_each_thread(g, t); | |
4804 | ||
4805 | unlock: | |
4806 | read_unlock_irqrestore(&tasklist_lock, flags); | |
4807 | free: | |
4808 | for (i = start; i < end; i++) | |
4809 | kfree(ret_stack_list[i]); | |
4810 | return ret; | |
4811 | } | |
4812 | ||
8aef2d28 | 4813 | static void |
38516ab5 SR |
4814 | ftrace_graph_probe_sched_switch(void *ignore, |
4815 | struct task_struct *prev, struct task_struct *next) | |
8aef2d28 SR |
4816 | { |
4817 | unsigned long long timestamp; | |
4818 | int index; | |
4819 | ||
be6f164a SR |
4820 | /* |
4821 | * Does the user want to count the time a function was asleep. | |
4822 | * If so, do not update the time stamps. | |
4823 | */ | |
4824 | if (trace_flags & TRACE_ITER_SLEEP_TIME) | |
4825 | return; | |
4826 | ||
8aef2d28 SR |
4827 | timestamp = trace_clock_local(); |
4828 | ||
4829 | prev->ftrace_timestamp = timestamp; | |
4830 | ||
4831 | /* only process tasks that we timestamped */ | |
4832 | if (!next->ftrace_timestamp) | |
4833 | return; | |
4834 | ||
4835 | /* | |
4836 | * Update all the counters in next to make up for the | |
4837 | * time next was sleeping. | |
4838 | */ | |
4839 | timestamp -= next->ftrace_timestamp; | |
4840 | ||
4841 | for (index = next->curr_ret_stack; index >= 0; index--) | |
4842 | next->ret_stack[index].calltime += timestamp; | |
4843 | } | |
4844 | ||
f201ae23 | 4845 | /* Allocate a return stack for each task */ |
fb52607a | 4846 | static int start_graph_tracing(void) |
f201ae23 FW |
4847 | { |
4848 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 4849 | int ret, cpu; |
f201ae23 FW |
4850 | |
4851 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
4852 | sizeof(struct ftrace_ret_stack *), | |
4853 | GFP_KERNEL); | |
4854 | ||
4855 | if (!ret_stack_list) | |
4856 | return -ENOMEM; | |
4857 | ||
5b058bcd | 4858 | /* The cpu_boot init_task->ret_stack will never be freed */ |
179c498a SR |
4859 | for_each_online_cpu(cpu) { |
4860 | if (!idle_task(cpu)->ret_stack) | |
868baf07 | 4861 | ftrace_graph_init_idle_task(idle_task(cpu), cpu); |
179c498a | 4862 | } |
5b058bcd | 4863 | |
f201ae23 FW |
4864 | do { |
4865 | ret = alloc_retstack_tasklist(ret_stack_list); | |
4866 | } while (ret == -EAGAIN); | |
4867 | ||
8aef2d28 | 4868 | if (!ret) { |
38516ab5 | 4869 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
8aef2d28 SR |
4870 | if (ret) |
4871 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
4872 | " probe to kernel_sched_switch\n"); | |
4873 | } | |
4874 | ||
f201ae23 FW |
4875 | kfree(ret_stack_list); |
4876 | return ret; | |
4877 | } | |
4878 | ||
4a2b8dda FW |
4879 | /* |
4880 | * Hibernation protection. | |
4881 | * The state of the current task is too much unstable during | |
4882 | * suspend/restore to disk. We want to protect against that. | |
4883 | */ | |
4884 | static int | |
4885 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
4886 | void *unused) | |
4887 | { | |
4888 | switch (state) { | |
4889 | case PM_HIBERNATION_PREPARE: | |
4890 | pause_graph_tracing(); | |
4891 | break; | |
4892 | ||
4893 | case PM_POST_HIBERNATION: | |
4894 | unpause_graph_tracing(); | |
4895 | break; | |
4896 | } | |
4897 | return NOTIFY_DONE; | |
4898 | } | |
4899 | ||
287b6e68 FW |
4900 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
4901 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 4902 | { |
e7d3737e FW |
4903 | int ret = 0; |
4904 | ||
e6ea44e9 | 4905 | mutex_lock(&ftrace_lock); |
e7d3737e | 4906 | |
05ce5818 | 4907 | /* we currently allow only one tracer registered at a time */ |
597af815 | 4908 | if (ftrace_graph_active) { |
05ce5818 SR |
4909 | ret = -EBUSY; |
4910 | goto out; | |
4911 | } | |
4912 | ||
4a2b8dda FW |
4913 | ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; |
4914 | register_pm_notifier(&ftrace_suspend_notifier); | |
4915 | ||
597af815 | 4916 | ftrace_graph_active++; |
fb52607a | 4917 | ret = start_graph_tracing(); |
f201ae23 | 4918 | if (ret) { |
597af815 | 4919 | ftrace_graph_active--; |
f201ae23 FW |
4920 | goto out; |
4921 | } | |
e53a6319 | 4922 | |
287b6e68 FW |
4923 | ftrace_graph_return = retfunc; |
4924 | ftrace_graph_entry = entryfunc; | |
e53a6319 | 4925 | |
a1cd6173 | 4926 | ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET); |
e7d3737e FW |
4927 | |
4928 | out: | |
e6ea44e9 | 4929 | mutex_unlock(&ftrace_lock); |
e7d3737e | 4930 | return ret; |
15e6cb36 FW |
4931 | } |
4932 | ||
fb52607a | 4933 | void unregister_ftrace_graph(void) |
15e6cb36 | 4934 | { |
e6ea44e9 | 4935 | mutex_lock(&ftrace_lock); |
e7d3737e | 4936 | |
597af815 | 4937 | if (unlikely(!ftrace_graph_active)) |
2aad1b76 SR |
4938 | goto out; |
4939 | ||
597af815 | 4940 | ftrace_graph_active--; |
287b6e68 | 4941 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 4942 | ftrace_graph_entry = ftrace_graph_entry_stub; |
bd69c30b | 4943 | ftrace_shutdown(&global_ops, FTRACE_STOP_FUNC_RET); |
4a2b8dda | 4944 | unregister_pm_notifier(&ftrace_suspend_notifier); |
38516ab5 | 4945 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
e7d3737e | 4946 | |
2aad1b76 | 4947 | out: |
e6ea44e9 | 4948 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 4949 | } |
f201ae23 | 4950 | |
868baf07 SR |
4951 | static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack); |
4952 | ||
4953 | static void | |
4954 | graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack) | |
4955 | { | |
4956 | atomic_set(&t->tracing_graph_pause, 0); | |
4957 | atomic_set(&t->trace_overrun, 0); | |
4958 | t->ftrace_timestamp = 0; | |
25985edc | 4959 | /* make curr_ret_stack visible before we add the ret_stack */ |
868baf07 SR |
4960 | smp_wmb(); |
4961 | t->ret_stack = ret_stack; | |
4962 | } | |
4963 | ||
4964 | /* | |
4965 | * Allocate a return stack for the idle task. May be the first | |
4966 | * time through, or it may be done by CPU hotplug online. | |
4967 | */ | |
4968 | void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) | |
4969 | { | |
4970 | t->curr_ret_stack = -1; | |
4971 | /* | |
4972 | * The idle task has no parent, it either has its own | |
4973 | * stack or no stack at all. | |
4974 | */ | |
4975 | if (t->ret_stack) | |
4976 | WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu)); | |
4977 | ||
4978 | if (ftrace_graph_active) { | |
4979 | struct ftrace_ret_stack *ret_stack; | |
4980 | ||
4981 | ret_stack = per_cpu(idle_ret_stack, cpu); | |
4982 | if (!ret_stack) { | |
4983 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
4984 | * sizeof(struct ftrace_ret_stack), | |
4985 | GFP_KERNEL); | |
4986 | if (!ret_stack) | |
4987 | return; | |
4988 | per_cpu(idle_ret_stack, cpu) = ret_stack; | |
4989 | } | |
4990 | graph_init_task(t, ret_stack); | |
4991 | } | |
4992 | } | |
4993 | ||
f201ae23 | 4994 | /* Allocate a return stack for newly created task */ |
fb52607a | 4995 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 4996 | { |
84047e36 SR |
4997 | /* Make sure we do not use the parent ret_stack */ |
4998 | t->ret_stack = NULL; | |
ea14eb71 | 4999 | t->curr_ret_stack = -1; |
84047e36 | 5000 | |
597af815 | 5001 | if (ftrace_graph_active) { |
82310a32 SR |
5002 | struct ftrace_ret_stack *ret_stack; |
5003 | ||
5004 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
f201ae23 FW |
5005 | * sizeof(struct ftrace_ret_stack), |
5006 | GFP_KERNEL); | |
82310a32 | 5007 | if (!ret_stack) |
f201ae23 | 5008 | return; |
868baf07 | 5009 | graph_init_task(t, ret_stack); |
84047e36 | 5010 | } |
f201ae23 FW |
5011 | } |
5012 | ||
fb52607a | 5013 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 5014 | { |
eae849ca FW |
5015 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
5016 | ||
f201ae23 | 5017 | t->ret_stack = NULL; |
eae849ca FW |
5018 | /* NULL must become visible to IRQs before we free it: */ |
5019 | barrier(); | |
5020 | ||
5021 | kfree(ret_stack); | |
f201ae23 | 5022 | } |
14a866c5 SR |
5023 | |
5024 | void ftrace_graph_stop(void) | |
5025 | { | |
5026 | ftrace_stop(); | |
5027 | } | |
15e6cb36 | 5028 | #endif |