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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 | ||
2f5f6ad9 SR |
67 | static struct ftrace_ops ftrace_list_end __read_mostly = { |
68 | .func = ftrace_stub, | |
4740974a | 69 | .flags = FTRACE_OPS_FL_RECURSION_SAFE, |
2f5f6ad9 SR |
70 | }; |
71 | ||
4eebcc81 SR |
72 | /* ftrace_enabled is a method to turn ftrace on or off */ |
73 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 74 | static int last_ftrace_enabled; |
b0fc494f | 75 | |
60a7ecf4 | 76 | /* Quick disabling of function tracer. */ |
2f5f6ad9 SR |
77 | int function_trace_stop __read_mostly; |
78 | ||
79 | /* Current function tracing op */ | |
80 | struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end; | |
60a7ecf4 | 81 | |
756d17ee | 82 | /* List for set_ftrace_pid's pids. */ |
83 | LIST_HEAD(ftrace_pids); | |
84 | struct ftrace_pid { | |
85 | struct list_head list; | |
86 | struct pid *pid; | |
87 | }; | |
88 | ||
4eebcc81 SR |
89 | /* |
90 | * ftrace_disabled is set when an anomaly is discovered. | |
91 | * ftrace_disabled is much stronger than ftrace_enabled. | |
92 | */ | |
93 | static int ftrace_disabled __read_mostly; | |
94 | ||
52baf119 | 95 | static DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 96 | |
b848914c | 97 | static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end; |
e248491a | 98 | static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end; |
b848914c | 99 | static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end; |
16444a8a | 100 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
df4fc315 | 101 | ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; |
2b499381 | 102 | static struct ftrace_ops global_ops; |
e248491a | 103 | static struct ftrace_ops control_ops; |
16444a8a | 104 | |
2f5f6ad9 SR |
105 | #if ARCH_SUPPORTS_FTRACE_OPS |
106 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 107 | struct ftrace_ops *op, struct pt_regs *regs); |
2f5f6ad9 SR |
108 | #else |
109 | /* See comment below, where ftrace_ops_list_func is defined */ | |
110 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip); | |
111 | #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops) | |
112 | #endif | |
b848914c | 113 | |
0a016409 SR |
114 | /* |
115 | * Traverse the ftrace_global_list, invoking all entries. The reason that we | |
116 | * can use rcu_dereference_raw() is that elements removed from this list | |
117 | * are simply leaked, so there is no need to interact with a grace-period | |
118 | * mechanism. The rcu_dereference_raw() calls are needed to handle | |
119 | * concurrent insertions into the ftrace_global_list. | |
120 | * | |
121 | * Silly Alpha and silly pointer-speculation compiler optimizations! | |
122 | */ | |
123 | #define do_for_each_ftrace_op(op, list) \ | |
124 | op = rcu_dereference_raw(list); \ | |
125 | do | |
126 | ||
127 | /* | |
128 | * Optimized for just a single item in the list (as that is the normal case). | |
129 | */ | |
130 | #define while_for_each_ftrace_op(op) \ | |
131 | while (likely(op = rcu_dereference_raw((op)->next)) && \ | |
132 | unlikely((op) != &ftrace_list_end)) | |
133 | ||
ea701f11 SR |
134 | /** |
135 | * ftrace_nr_registered_ops - return number of ops registered | |
136 | * | |
137 | * Returns the number of ftrace_ops registered and tracing functions | |
138 | */ | |
139 | int ftrace_nr_registered_ops(void) | |
140 | { | |
141 | struct ftrace_ops *ops; | |
142 | int cnt = 0; | |
143 | ||
144 | mutex_lock(&ftrace_lock); | |
145 | ||
146 | for (ops = ftrace_ops_list; | |
147 | ops != &ftrace_list_end; ops = ops->next) | |
148 | cnt++; | |
149 | ||
150 | mutex_unlock(&ftrace_lock); | |
151 | ||
152 | return cnt; | |
153 | } | |
154 | ||
2f5f6ad9 SR |
155 | static void |
156 | ftrace_global_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 157 | struct ftrace_ops *op, struct pt_regs *regs) |
16444a8a | 158 | { |
c29f122c SR |
159 | int bit; |
160 | ||
edc15caf SR |
161 | bit = trace_test_and_set_recursion(TRACE_GLOBAL_START, TRACE_GLOBAL_MAX); |
162 | if (bit < 0) | |
b1cff0ad | 163 | return; |
16444a8a | 164 | |
0a016409 | 165 | do_for_each_ftrace_op(op, ftrace_global_list) { |
a1e2e31d | 166 | op->func(ip, parent_ip, op, regs); |
0a016409 | 167 | } while_for_each_ftrace_op(op); |
edc15caf SR |
168 | |
169 | trace_clear_recursion(bit); | |
16444a8a ACM |
170 | } |
171 | ||
2f5f6ad9 | 172 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 173 | struct ftrace_ops *op, struct pt_regs *regs) |
df4fc315 | 174 | { |
0ef8cde5 | 175 | if (!test_tsk_trace_trace(current)) |
df4fc315 SR |
176 | return; |
177 | ||
a1e2e31d | 178 | ftrace_pid_function(ip, parent_ip, op, regs); |
df4fc315 SR |
179 | } |
180 | ||
181 | static void set_ftrace_pid_function(ftrace_func_t func) | |
182 | { | |
183 | /* do not set ftrace_pid_function to itself! */ | |
184 | if (func != ftrace_pid_func) | |
185 | ftrace_pid_function = func; | |
186 | } | |
187 | ||
16444a8a | 188 | /** |
3d083395 | 189 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 190 | * |
3d083395 SR |
191 | * This NULLs the ftrace function and in essence stops |
192 | * tracing. There may be lag | |
16444a8a | 193 | */ |
3d083395 | 194 | void clear_ftrace_function(void) |
16444a8a | 195 | { |
3d083395 | 196 | ftrace_trace_function = ftrace_stub; |
df4fc315 | 197 | ftrace_pid_function = ftrace_stub; |
3d083395 SR |
198 | } |
199 | ||
e248491a JO |
200 | static void control_ops_disable_all(struct ftrace_ops *ops) |
201 | { | |
202 | int cpu; | |
203 | ||
204 | for_each_possible_cpu(cpu) | |
205 | *per_cpu_ptr(ops->disabled, cpu) = 1; | |
206 | } | |
207 | ||
208 | static int control_ops_alloc(struct ftrace_ops *ops) | |
209 | { | |
210 | int __percpu *disabled; | |
211 | ||
212 | disabled = alloc_percpu(int); | |
213 | if (!disabled) | |
214 | return -ENOMEM; | |
215 | ||
216 | ops->disabled = disabled; | |
217 | control_ops_disable_all(ops); | |
218 | return 0; | |
219 | } | |
220 | ||
221 | static void control_ops_free(struct ftrace_ops *ops) | |
222 | { | |
223 | free_percpu(ops->disabled); | |
224 | } | |
225 | ||
2b499381 | 226 | static void update_global_ops(void) |
491d0dcf SR |
227 | { |
228 | ftrace_func_t func; | |
229 | ||
230 | /* | |
231 | * If there's only one function registered, then call that | |
232 | * function directly. Otherwise, we need to iterate over the | |
233 | * registered callers. | |
234 | */ | |
b848914c | 235 | if (ftrace_global_list == &ftrace_list_end || |
63503794 | 236 | ftrace_global_list->next == &ftrace_list_end) { |
b848914c | 237 | func = ftrace_global_list->func; |
63503794 SR |
238 | /* |
239 | * As we are calling the function directly. | |
240 | * If it does not have recursion protection, | |
241 | * the function_trace_op needs to be updated | |
242 | * accordingly. | |
243 | */ | |
244 | if (ftrace_global_list->flags & FTRACE_OPS_FL_RECURSION_SAFE) | |
245 | global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE; | |
246 | else | |
247 | global_ops.flags &= ~FTRACE_OPS_FL_RECURSION_SAFE; | |
248 | } else { | |
b848914c | 249 | func = ftrace_global_list_func; |
63503794 SR |
250 | /* The list has its own recursion protection. */ |
251 | global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE; | |
252 | } | |
253 | ||
491d0dcf SR |
254 | |
255 | /* If we filter on pids, update to use the pid function */ | |
256 | if (!list_empty(&ftrace_pids)) { | |
257 | set_ftrace_pid_function(func); | |
258 | func = ftrace_pid_func; | |
259 | } | |
2b499381 SR |
260 | |
261 | global_ops.func = func; | |
262 | } | |
263 | ||
264 | static void update_ftrace_function(void) | |
265 | { | |
266 | ftrace_func_t func; | |
267 | ||
268 | update_global_ops(); | |
269 | ||
cdbe61bf SR |
270 | /* |
271 | * If we are at the end of the list and this ops is | |
4740974a SR |
272 | * recursion safe and not dynamic and the arch supports passing ops, |
273 | * then have the mcount trampoline call the function directly. | |
cdbe61bf | 274 | */ |
b848914c | 275 | if (ftrace_ops_list == &ftrace_list_end || |
cdbe61bf | 276 | (ftrace_ops_list->next == &ftrace_list_end && |
2f5f6ad9 | 277 | !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC) && |
4740974a | 278 | (ftrace_ops_list->flags & FTRACE_OPS_FL_RECURSION_SAFE) && |
ccf3672d | 279 | !FTRACE_FORCE_LIST_FUNC)) { |
2f5f6ad9 SR |
280 | /* Set the ftrace_ops that the arch callback uses */ |
281 | if (ftrace_ops_list == &global_ops) | |
282 | function_trace_op = ftrace_global_list; | |
283 | else | |
284 | function_trace_op = ftrace_ops_list; | |
b848914c | 285 | func = ftrace_ops_list->func; |
2f5f6ad9 SR |
286 | } else { |
287 | /* Just use the default ftrace_ops */ | |
288 | function_trace_op = &ftrace_list_end; | |
b848914c | 289 | func = ftrace_ops_list_func; |
2f5f6ad9 | 290 | } |
2b499381 | 291 | |
491d0dcf | 292 | ftrace_trace_function = func; |
491d0dcf SR |
293 | } |
294 | ||
2b499381 | 295 | static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
3d083395 | 296 | { |
2b499381 | 297 | ops->next = *list; |
16444a8a | 298 | /* |
b848914c | 299 | * We are entering ops into the list but another |
16444a8a ACM |
300 | * CPU might be walking that list. We need to make sure |
301 | * the ops->next pointer is valid before another CPU sees | |
b848914c | 302 | * the ops pointer included into the list. |
16444a8a | 303 | */ |
2b499381 | 304 | rcu_assign_pointer(*list, ops); |
16444a8a ACM |
305 | } |
306 | ||
2b499381 | 307 | static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
16444a8a | 308 | { |
16444a8a | 309 | struct ftrace_ops **p; |
16444a8a ACM |
310 | |
311 | /* | |
3d083395 SR |
312 | * If we are removing the last function, then simply point |
313 | * to the ftrace_stub. | |
16444a8a | 314 | */ |
2b499381 SR |
315 | if (*list == ops && ops->next == &ftrace_list_end) { |
316 | *list = &ftrace_list_end; | |
e6ea44e9 | 317 | return 0; |
16444a8a ACM |
318 | } |
319 | ||
2b499381 | 320 | for (p = list; *p != &ftrace_list_end; p = &(*p)->next) |
16444a8a ACM |
321 | if (*p == ops) |
322 | break; | |
323 | ||
e6ea44e9 SR |
324 | if (*p != ops) |
325 | return -1; | |
16444a8a ACM |
326 | |
327 | *p = (*p)->next; | |
2b499381 SR |
328 | return 0; |
329 | } | |
16444a8a | 330 | |
e248491a JO |
331 | static void add_ftrace_list_ops(struct ftrace_ops **list, |
332 | struct ftrace_ops *main_ops, | |
333 | struct ftrace_ops *ops) | |
334 | { | |
335 | int first = *list == &ftrace_list_end; | |
336 | add_ftrace_ops(list, ops); | |
337 | if (first) | |
338 | add_ftrace_ops(&ftrace_ops_list, main_ops); | |
339 | } | |
340 | ||
341 | static int remove_ftrace_list_ops(struct ftrace_ops **list, | |
342 | struct ftrace_ops *main_ops, | |
343 | struct ftrace_ops *ops) | |
344 | { | |
345 | int ret = remove_ftrace_ops(list, ops); | |
346 | if (!ret && *list == &ftrace_list_end) | |
347 | ret = remove_ftrace_ops(&ftrace_ops_list, main_ops); | |
348 | return ret; | |
349 | } | |
350 | ||
2b499381 SR |
351 | static int __register_ftrace_function(struct ftrace_ops *ops) |
352 | { | |
8d240dd8 | 353 | if (unlikely(ftrace_disabled)) |
2b499381 SR |
354 | return -ENODEV; |
355 | ||
356 | if (FTRACE_WARN_ON(ops == &global_ops)) | |
357 | return -EINVAL; | |
358 | ||
b848914c SR |
359 | if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) |
360 | return -EBUSY; | |
361 | ||
e248491a JO |
362 | /* We don't support both control and global flags set. */ |
363 | if ((ops->flags & FL_GLOBAL_CONTROL_MASK) == FL_GLOBAL_CONTROL_MASK) | |
364 | return -EINVAL; | |
365 | ||
06aeaaea | 366 | #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
08f6fba5 SR |
367 | /* |
368 | * If the ftrace_ops specifies SAVE_REGS, then it only can be used | |
369 | * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set. | |
370 | * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant. | |
371 | */ | |
372 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS && | |
373 | !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)) | |
374 | return -EINVAL; | |
375 | ||
376 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED) | |
377 | ops->flags |= FTRACE_OPS_FL_SAVE_REGS; | |
378 | #endif | |
379 | ||
cdbe61bf SR |
380 | if (!core_kernel_data((unsigned long)ops)) |
381 | ops->flags |= FTRACE_OPS_FL_DYNAMIC; | |
382 | ||
b848914c | 383 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { |
e248491a | 384 | add_ftrace_list_ops(&ftrace_global_list, &global_ops, ops); |
b848914c | 385 | ops->flags |= FTRACE_OPS_FL_ENABLED; |
e248491a JO |
386 | } else if (ops->flags & FTRACE_OPS_FL_CONTROL) { |
387 | if (control_ops_alloc(ops)) | |
388 | return -ENOMEM; | |
389 | add_ftrace_list_ops(&ftrace_control_list, &control_ops, ops); | |
b848914c SR |
390 | } else |
391 | add_ftrace_ops(&ftrace_ops_list, ops); | |
392 | ||
2b499381 SR |
393 | if (ftrace_enabled) |
394 | update_ftrace_function(); | |
395 | ||
396 | return 0; | |
397 | } | |
398 | ||
399 | static int __unregister_ftrace_function(struct ftrace_ops *ops) | |
400 | { | |
401 | int ret; | |
402 | ||
403 | if (ftrace_disabled) | |
404 | return -ENODEV; | |
405 | ||
b848914c SR |
406 | if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) |
407 | return -EBUSY; | |
408 | ||
2b499381 SR |
409 | if (FTRACE_WARN_ON(ops == &global_ops)) |
410 | return -EINVAL; | |
411 | ||
b848914c | 412 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { |
e248491a JO |
413 | ret = remove_ftrace_list_ops(&ftrace_global_list, |
414 | &global_ops, ops); | |
b848914c SR |
415 | if (!ret) |
416 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; | |
e248491a JO |
417 | } else if (ops->flags & FTRACE_OPS_FL_CONTROL) { |
418 | ret = remove_ftrace_list_ops(&ftrace_control_list, | |
419 | &control_ops, ops); | |
420 | if (!ret) { | |
421 | /* | |
422 | * The ftrace_ops is now removed from the list, | |
423 | * so there'll be no new users. We must ensure | |
424 | * all current users are done before we free | |
425 | * the control data. | |
426 | */ | |
427 | synchronize_sched(); | |
428 | control_ops_free(ops); | |
429 | } | |
b848914c SR |
430 | } else |
431 | ret = remove_ftrace_ops(&ftrace_ops_list, ops); | |
432 | ||
2b499381 SR |
433 | if (ret < 0) |
434 | return ret; | |
b848914c | 435 | |
491d0dcf SR |
436 | if (ftrace_enabled) |
437 | update_ftrace_function(); | |
16444a8a | 438 | |
cdbe61bf SR |
439 | /* |
440 | * Dynamic ops may be freed, we must make sure that all | |
441 | * callers are done before leaving this function. | |
442 | */ | |
443 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC) | |
444 | synchronize_sched(); | |
445 | ||
e6ea44e9 | 446 | return 0; |
3d083395 SR |
447 | } |
448 | ||
df4fc315 SR |
449 | static void ftrace_update_pid_func(void) |
450 | { | |
491d0dcf | 451 | /* Only do something if we are tracing something */ |
df4fc315 | 452 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 453 | return; |
df4fc315 | 454 | |
491d0dcf | 455 | update_ftrace_function(); |
df4fc315 SR |
456 | } |
457 | ||
493762fc SR |
458 | #ifdef CONFIG_FUNCTION_PROFILER |
459 | struct ftrace_profile { | |
460 | struct hlist_node node; | |
461 | unsigned long ip; | |
462 | unsigned long counter; | |
0706f1c4 SR |
463 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
464 | unsigned long long time; | |
e330b3bc | 465 | unsigned long long time_squared; |
0706f1c4 | 466 | #endif |
8fc0c701 SR |
467 | }; |
468 | ||
493762fc SR |
469 | struct ftrace_profile_page { |
470 | struct ftrace_profile_page *next; | |
471 | unsigned long index; | |
472 | struct ftrace_profile records[]; | |
d61f82d0 SR |
473 | }; |
474 | ||
cafb168a SR |
475 | struct ftrace_profile_stat { |
476 | atomic_t disabled; | |
477 | struct hlist_head *hash; | |
478 | struct ftrace_profile_page *pages; | |
479 | struct ftrace_profile_page *start; | |
480 | struct tracer_stat stat; | |
481 | }; | |
482 | ||
493762fc SR |
483 | #define PROFILE_RECORDS_SIZE \ |
484 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 485 | |
493762fc SR |
486 | #define PROFILES_PER_PAGE \ |
487 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 488 | |
fb9fb015 SR |
489 | static int ftrace_profile_bits __read_mostly; |
490 | static int ftrace_profile_enabled __read_mostly; | |
491 | ||
492 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
493 | static DEFINE_MUTEX(ftrace_profile_lock); |
494 | ||
cafb168a | 495 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc SR |
496 | |
497 | #define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */ | |
498 | ||
bac429f0 SR |
499 | static void * |
500 | function_stat_next(void *v, int idx) | |
501 | { | |
493762fc SR |
502 | struct ftrace_profile *rec = v; |
503 | struct ftrace_profile_page *pg; | |
bac429f0 | 504 | |
493762fc | 505 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
506 | |
507 | again: | |
0296e425 LZ |
508 | if (idx != 0) |
509 | rec++; | |
510 | ||
bac429f0 SR |
511 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
512 | pg = pg->next; | |
513 | if (!pg) | |
514 | return NULL; | |
515 | rec = &pg->records[0]; | |
493762fc SR |
516 | if (!rec->counter) |
517 | goto again; | |
bac429f0 SR |
518 | } |
519 | ||
bac429f0 SR |
520 | return rec; |
521 | } | |
522 | ||
523 | static void *function_stat_start(struct tracer_stat *trace) | |
524 | { | |
cafb168a SR |
525 | struct ftrace_profile_stat *stat = |
526 | container_of(trace, struct ftrace_profile_stat, stat); | |
527 | ||
528 | if (!stat || !stat->start) | |
529 | return NULL; | |
530 | ||
531 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
532 | } |
533 | ||
0706f1c4 SR |
534 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
535 | /* function graph compares on total time */ | |
536 | static int function_stat_cmp(void *p1, void *p2) | |
537 | { | |
538 | struct ftrace_profile *a = p1; | |
539 | struct ftrace_profile *b = p2; | |
540 | ||
541 | if (a->time < b->time) | |
542 | return -1; | |
543 | if (a->time > b->time) | |
544 | return 1; | |
545 | else | |
546 | return 0; | |
547 | } | |
548 | #else | |
549 | /* not function graph compares against hits */ | |
bac429f0 SR |
550 | static int function_stat_cmp(void *p1, void *p2) |
551 | { | |
493762fc SR |
552 | struct ftrace_profile *a = p1; |
553 | struct ftrace_profile *b = p2; | |
bac429f0 SR |
554 | |
555 | if (a->counter < b->counter) | |
556 | return -1; | |
557 | if (a->counter > b->counter) | |
558 | return 1; | |
559 | else | |
560 | return 0; | |
561 | } | |
0706f1c4 | 562 | #endif |
bac429f0 SR |
563 | |
564 | static int function_stat_headers(struct seq_file *m) | |
565 | { | |
0706f1c4 | 566 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b | 567 | seq_printf(m, " Function " |
e330b3bc | 568 | "Hit Time Avg s^2\n" |
34886c8b | 569 | " -------- " |
e330b3bc | 570 | "--- ---- --- ---\n"); |
0706f1c4 | 571 | #else |
bac429f0 SR |
572 | seq_printf(m, " Function Hit\n" |
573 | " -------- ---\n"); | |
0706f1c4 | 574 | #endif |
bac429f0 SR |
575 | return 0; |
576 | } | |
577 | ||
578 | static int function_stat_show(struct seq_file *m, void *v) | |
579 | { | |
493762fc | 580 | struct ftrace_profile *rec = v; |
bac429f0 | 581 | char str[KSYM_SYMBOL_LEN]; |
3aaba20f | 582 | int ret = 0; |
0706f1c4 | 583 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
584 | static struct trace_seq s; |
585 | unsigned long long avg; | |
e330b3bc | 586 | unsigned long long stddev; |
0706f1c4 | 587 | #endif |
3aaba20f LZ |
588 | mutex_lock(&ftrace_profile_lock); |
589 | ||
590 | /* we raced with function_profile_reset() */ | |
591 | if (unlikely(rec->counter == 0)) { | |
592 | ret = -EBUSY; | |
593 | goto out; | |
594 | } | |
bac429f0 SR |
595 | |
596 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
0706f1c4 SR |
597 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
598 | ||
599 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
600 | seq_printf(m, " "); | |
34886c8b SR |
601 | avg = rec->time; |
602 | do_div(avg, rec->counter); | |
603 | ||
e330b3bc CD |
604 | /* Sample standard deviation (s^2) */ |
605 | if (rec->counter <= 1) | |
606 | stddev = 0; | |
607 | else { | |
608 | stddev = rec->time_squared - rec->counter * avg * avg; | |
609 | /* | |
610 | * Divide only 1000 for ns^2 -> us^2 conversion. | |
611 | * trace_print_graph_duration will divide 1000 again. | |
612 | */ | |
613 | do_div(stddev, (rec->counter - 1) * 1000); | |
614 | } | |
615 | ||
34886c8b SR |
616 | trace_seq_init(&s); |
617 | trace_print_graph_duration(rec->time, &s); | |
618 | trace_seq_puts(&s, " "); | |
619 | trace_print_graph_duration(avg, &s); | |
e330b3bc CD |
620 | trace_seq_puts(&s, " "); |
621 | trace_print_graph_duration(stddev, &s); | |
0706f1c4 | 622 | trace_print_seq(m, &s); |
0706f1c4 SR |
623 | #endif |
624 | seq_putc(m, '\n'); | |
3aaba20f LZ |
625 | out: |
626 | mutex_unlock(&ftrace_profile_lock); | |
bac429f0 | 627 | |
3aaba20f | 628 | return ret; |
bac429f0 SR |
629 | } |
630 | ||
cafb168a | 631 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 632 | { |
493762fc | 633 | struct ftrace_profile_page *pg; |
bac429f0 | 634 | |
cafb168a | 635 | pg = stat->pages = stat->start; |
bac429f0 | 636 | |
493762fc SR |
637 | while (pg) { |
638 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
639 | pg->index = 0; | |
640 | pg = pg->next; | |
bac429f0 SR |
641 | } |
642 | ||
cafb168a | 643 | memset(stat->hash, 0, |
493762fc SR |
644 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
645 | } | |
bac429f0 | 646 | |
cafb168a | 647 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
648 | { |
649 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
650 | int functions; |
651 | int pages; | |
493762fc | 652 | int i; |
bac429f0 | 653 | |
493762fc | 654 | /* If we already allocated, do nothing */ |
cafb168a | 655 | if (stat->pages) |
493762fc | 656 | return 0; |
bac429f0 | 657 | |
cafb168a SR |
658 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
659 | if (!stat->pages) | |
493762fc | 660 | return -ENOMEM; |
bac429f0 | 661 | |
318e0a73 SR |
662 | #ifdef CONFIG_DYNAMIC_FTRACE |
663 | functions = ftrace_update_tot_cnt; | |
664 | #else | |
665 | /* | |
666 | * We do not know the number of functions that exist because | |
667 | * dynamic tracing is what counts them. With past experience | |
668 | * we have around 20K functions. That should be more than enough. | |
669 | * It is highly unlikely we will execute every function in | |
670 | * the kernel. | |
671 | */ | |
672 | functions = 20000; | |
673 | #endif | |
674 | ||
cafb168a | 675 | pg = stat->start = stat->pages; |
bac429f0 | 676 | |
318e0a73 SR |
677 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
678 | ||
679 | for (i = 0; i < pages; i++) { | |
493762fc | 680 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 681 | if (!pg->next) |
318e0a73 | 682 | goto out_free; |
493762fc SR |
683 | pg = pg->next; |
684 | } | |
685 | ||
686 | return 0; | |
318e0a73 SR |
687 | |
688 | out_free: | |
689 | pg = stat->start; | |
690 | while (pg) { | |
691 | unsigned long tmp = (unsigned long)pg; | |
692 | ||
693 | pg = pg->next; | |
694 | free_page(tmp); | |
695 | } | |
696 | ||
697 | free_page((unsigned long)stat->pages); | |
698 | stat->pages = NULL; | |
699 | stat->start = NULL; | |
700 | ||
701 | return -ENOMEM; | |
bac429f0 SR |
702 | } |
703 | ||
cafb168a | 704 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 705 | { |
cafb168a | 706 | struct ftrace_profile_stat *stat; |
493762fc | 707 | int size; |
bac429f0 | 708 | |
cafb168a SR |
709 | stat = &per_cpu(ftrace_profile_stats, cpu); |
710 | ||
711 | if (stat->hash) { | |
493762fc | 712 | /* If the profile is already created, simply reset it */ |
cafb168a | 713 | ftrace_profile_reset(stat); |
493762fc SR |
714 | return 0; |
715 | } | |
bac429f0 | 716 | |
493762fc SR |
717 | /* |
718 | * We are profiling all functions, but usually only a few thousand | |
719 | * functions are hit. We'll make a hash of 1024 items. | |
720 | */ | |
721 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 722 | |
cafb168a | 723 | stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
493762fc | 724 | |
cafb168a | 725 | if (!stat->hash) |
493762fc SR |
726 | return -ENOMEM; |
727 | ||
cafb168a SR |
728 | if (!ftrace_profile_bits) { |
729 | size--; | |
493762fc | 730 | |
cafb168a SR |
731 | for (; size; size >>= 1) |
732 | ftrace_profile_bits++; | |
733 | } | |
493762fc | 734 | |
318e0a73 | 735 | /* Preallocate the function profiling pages */ |
cafb168a SR |
736 | if (ftrace_profile_pages_init(stat) < 0) { |
737 | kfree(stat->hash); | |
738 | stat->hash = NULL; | |
493762fc SR |
739 | return -ENOMEM; |
740 | } | |
741 | ||
742 | return 0; | |
bac429f0 SR |
743 | } |
744 | ||
cafb168a SR |
745 | static int ftrace_profile_init(void) |
746 | { | |
747 | int cpu; | |
748 | int ret = 0; | |
749 | ||
750 | for_each_online_cpu(cpu) { | |
751 | ret = ftrace_profile_init_cpu(cpu); | |
752 | if (ret) | |
753 | break; | |
754 | } | |
755 | ||
756 | return ret; | |
757 | } | |
758 | ||
493762fc | 759 | /* interrupts must be disabled */ |
cafb168a SR |
760 | static struct ftrace_profile * |
761 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 762 | { |
493762fc | 763 | struct ftrace_profile *rec; |
bac429f0 SR |
764 | struct hlist_head *hhd; |
765 | struct hlist_node *n; | |
bac429f0 SR |
766 | unsigned long key; |
767 | ||
bac429f0 | 768 | key = hash_long(ip, ftrace_profile_bits); |
cafb168a | 769 | hhd = &stat->hash[key]; |
bac429f0 SR |
770 | |
771 | if (hlist_empty(hhd)) | |
772 | return NULL; | |
773 | ||
bac429f0 SR |
774 | hlist_for_each_entry_rcu(rec, n, hhd, node) { |
775 | if (rec->ip == ip) | |
493762fc SR |
776 | return rec; |
777 | } | |
778 | ||
779 | return NULL; | |
780 | } | |
781 | ||
cafb168a SR |
782 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
783 | struct ftrace_profile *rec) | |
493762fc SR |
784 | { |
785 | unsigned long key; | |
786 | ||
787 | key = hash_long(rec->ip, ftrace_profile_bits); | |
cafb168a | 788 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
789 | } |
790 | ||
318e0a73 SR |
791 | /* |
792 | * The memory is already allocated, this simply finds a new record to use. | |
793 | */ | |
493762fc | 794 | static struct ftrace_profile * |
318e0a73 | 795 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
796 | { |
797 | struct ftrace_profile *rec = NULL; | |
798 | ||
318e0a73 | 799 | /* prevent recursion (from NMIs) */ |
cafb168a | 800 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
801 | goto out; |
802 | ||
493762fc | 803 | /* |
318e0a73 SR |
804 | * Try to find the function again since an NMI |
805 | * could have added it | |
493762fc | 806 | */ |
cafb168a | 807 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 808 | if (rec) |
cafb168a | 809 | goto out; |
493762fc | 810 | |
cafb168a SR |
811 | if (stat->pages->index == PROFILES_PER_PAGE) { |
812 | if (!stat->pages->next) | |
813 | goto out; | |
814 | stat->pages = stat->pages->next; | |
bac429f0 | 815 | } |
493762fc | 816 | |
cafb168a | 817 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 818 | rec->ip = ip; |
cafb168a | 819 | ftrace_add_profile(stat, rec); |
493762fc | 820 | |
bac429f0 | 821 | out: |
cafb168a | 822 | atomic_dec(&stat->disabled); |
bac429f0 SR |
823 | |
824 | return rec; | |
825 | } | |
826 | ||
827 | static void | |
2f5f6ad9 | 828 | function_profile_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 829 | struct ftrace_ops *ops, struct pt_regs *regs) |
bac429f0 | 830 | { |
cafb168a | 831 | struct ftrace_profile_stat *stat; |
493762fc | 832 | struct ftrace_profile *rec; |
bac429f0 SR |
833 | unsigned long flags; |
834 | ||
835 | if (!ftrace_profile_enabled) | |
836 | return; | |
837 | ||
838 | local_irq_save(flags); | |
cafb168a SR |
839 | |
840 | stat = &__get_cpu_var(ftrace_profile_stats); | |
0f6ce3de | 841 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
842 | goto out; |
843 | ||
844 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 845 | if (!rec) { |
318e0a73 | 846 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
847 | if (!rec) |
848 | goto out; | |
849 | } | |
bac429f0 SR |
850 | |
851 | rec->counter++; | |
852 | out: | |
853 | local_irq_restore(flags); | |
854 | } | |
855 | ||
0706f1c4 SR |
856 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
857 | static int profile_graph_entry(struct ftrace_graph_ent *trace) | |
858 | { | |
a1e2e31d | 859 | function_profile_call(trace->func, 0, NULL, NULL); |
0706f1c4 SR |
860 | return 1; |
861 | } | |
862 | ||
863 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
864 | { | |
cafb168a | 865 | struct ftrace_profile_stat *stat; |
a2a16d6a | 866 | unsigned long long calltime; |
0706f1c4 | 867 | struct ftrace_profile *rec; |
cafb168a | 868 | unsigned long flags; |
0706f1c4 SR |
869 | |
870 | local_irq_save(flags); | |
cafb168a | 871 | stat = &__get_cpu_var(ftrace_profile_stats); |
0f6ce3de | 872 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
873 | goto out; |
874 | ||
37e44bc5 SR |
875 | /* If the calltime was zero'd ignore it */ |
876 | if (!trace->calltime) | |
877 | goto out; | |
878 | ||
a2a16d6a SR |
879 | calltime = trace->rettime - trace->calltime; |
880 | ||
881 | if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) { | |
882 | int index; | |
883 | ||
884 | index = trace->depth; | |
885 | ||
886 | /* Append this call time to the parent time to subtract */ | |
887 | if (index) | |
888 | current->ret_stack[index - 1].subtime += calltime; | |
889 | ||
890 | if (current->ret_stack[index].subtime < calltime) | |
891 | calltime -= current->ret_stack[index].subtime; | |
892 | else | |
893 | calltime = 0; | |
894 | } | |
895 | ||
cafb168a | 896 | rec = ftrace_find_profiled_func(stat, trace->func); |
e330b3bc | 897 | if (rec) { |
a2a16d6a | 898 | rec->time += calltime; |
e330b3bc CD |
899 | rec->time_squared += calltime * calltime; |
900 | } | |
a2a16d6a | 901 | |
cafb168a | 902 | out: |
0706f1c4 SR |
903 | local_irq_restore(flags); |
904 | } | |
905 | ||
906 | static int register_ftrace_profiler(void) | |
907 | { | |
908 | return register_ftrace_graph(&profile_graph_return, | |
909 | &profile_graph_entry); | |
910 | } | |
911 | ||
912 | static void unregister_ftrace_profiler(void) | |
913 | { | |
914 | unregister_ftrace_graph(); | |
915 | } | |
916 | #else | |
bd38c0e6 | 917 | static struct ftrace_ops ftrace_profile_ops __read_mostly = { |
fb9fb015 | 918 | .func = function_profile_call, |
4740974a | 919 | .flags = FTRACE_OPS_FL_RECURSION_SAFE, |
bac429f0 SR |
920 | }; |
921 | ||
0706f1c4 SR |
922 | static int register_ftrace_profiler(void) |
923 | { | |
924 | return register_ftrace_function(&ftrace_profile_ops); | |
925 | } | |
926 | ||
927 | static void unregister_ftrace_profiler(void) | |
928 | { | |
929 | unregister_ftrace_function(&ftrace_profile_ops); | |
930 | } | |
931 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
932 | ||
bac429f0 SR |
933 | static ssize_t |
934 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
935 | size_t cnt, loff_t *ppos) | |
936 | { | |
937 | unsigned long val; | |
bac429f0 SR |
938 | int ret; |
939 | ||
22fe9b54 PH |
940 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
941 | if (ret) | |
bac429f0 SR |
942 | return ret; |
943 | ||
944 | val = !!val; | |
945 | ||
946 | mutex_lock(&ftrace_profile_lock); | |
947 | if (ftrace_profile_enabled ^ val) { | |
948 | if (val) { | |
493762fc SR |
949 | ret = ftrace_profile_init(); |
950 | if (ret < 0) { | |
951 | cnt = ret; | |
952 | goto out; | |
953 | } | |
954 | ||
0706f1c4 SR |
955 | ret = register_ftrace_profiler(); |
956 | if (ret < 0) { | |
957 | cnt = ret; | |
958 | goto out; | |
959 | } | |
bac429f0 SR |
960 | ftrace_profile_enabled = 1; |
961 | } else { | |
962 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
963 | /* |
964 | * unregister_ftrace_profiler calls stop_machine | |
965 | * so this acts like an synchronize_sched. | |
966 | */ | |
0706f1c4 | 967 | unregister_ftrace_profiler(); |
bac429f0 SR |
968 | } |
969 | } | |
493762fc | 970 | out: |
bac429f0 SR |
971 | mutex_unlock(&ftrace_profile_lock); |
972 | ||
cf8517cf | 973 | *ppos += cnt; |
bac429f0 SR |
974 | |
975 | return cnt; | |
976 | } | |
977 | ||
493762fc SR |
978 | static ssize_t |
979 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
980 | size_t cnt, loff_t *ppos) | |
981 | { | |
fb9fb015 | 982 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
983 | int r; |
984 | ||
985 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
986 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
987 | } | |
988 | ||
bac429f0 SR |
989 | static const struct file_operations ftrace_profile_fops = { |
990 | .open = tracing_open_generic, | |
991 | .read = ftrace_profile_read, | |
992 | .write = ftrace_profile_write, | |
6038f373 | 993 | .llseek = default_llseek, |
bac429f0 SR |
994 | }; |
995 | ||
cafb168a SR |
996 | /* used to initialize the real stat files */ |
997 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
998 | .name = "functions", |
999 | .stat_start = function_stat_start, | |
1000 | .stat_next = function_stat_next, | |
1001 | .stat_cmp = function_stat_cmp, | |
1002 | .stat_headers = function_stat_headers, | |
1003 | .stat_show = function_stat_show | |
cafb168a SR |
1004 | }; |
1005 | ||
6ab5d668 | 1006 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 | 1007 | { |
cafb168a | 1008 | struct ftrace_profile_stat *stat; |
bac429f0 | 1009 | struct dentry *entry; |
cafb168a | 1010 | char *name; |
bac429f0 | 1011 | int ret; |
cafb168a SR |
1012 | int cpu; |
1013 | ||
1014 | for_each_possible_cpu(cpu) { | |
1015 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
1016 | ||
1017 | /* allocate enough for function name + cpu number */ | |
1018 | name = kmalloc(32, GFP_KERNEL); | |
1019 | if (!name) { | |
1020 | /* | |
1021 | * The files created are permanent, if something happens | |
1022 | * we still do not free memory. | |
1023 | */ | |
cafb168a SR |
1024 | WARN(1, |
1025 | "Could not allocate stat file for cpu %d\n", | |
1026 | cpu); | |
1027 | return; | |
1028 | } | |
1029 | stat->stat = function_stats; | |
1030 | snprintf(name, 32, "function%d", cpu); | |
1031 | stat->stat.name = name; | |
1032 | ret = register_stat_tracer(&stat->stat); | |
1033 | if (ret) { | |
1034 | WARN(1, | |
1035 | "Could not register function stat for cpu %d\n", | |
1036 | cpu); | |
1037 | kfree(name); | |
1038 | return; | |
1039 | } | |
bac429f0 SR |
1040 | } |
1041 | ||
1042 | entry = debugfs_create_file("function_profile_enabled", 0644, | |
1043 | d_tracer, NULL, &ftrace_profile_fops); | |
1044 | if (!entry) | |
1045 | pr_warning("Could not create debugfs " | |
1046 | "'function_profile_enabled' entry\n"); | |
1047 | } | |
1048 | ||
bac429f0 | 1049 | #else /* CONFIG_FUNCTION_PROFILER */ |
6ab5d668 | 1050 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 SR |
1051 | { |
1052 | } | |
bac429f0 SR |
1053 | #endif /* CONFIG_FUNCTION_PROFILER */ |
1054 | ||
493762fc SR |
1055 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; |
1056 | ||
1057 | #ifdef CONFIG_DYNAMIC_FTRACE | |
1058 | ||
1059 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD | |
1060 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
1061 | #endif | |
1062 | ||
1063 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; | |
1064 | ||
1065 | struct ftrace_func_probe { | |
1066 | struct hlist_node node; | |
1067 | struct ftrace_probe_ops *ops; | |
1068 | unsigned long flags; | |
1069 | unsigned long ip; | |
1070 | void *data; | |
1071 | struct rcu_head rcu; | |
1072 | }; | |
1073 | ||
b448c4e3 SR |
1074 | struct ftrace_func_entry { |
1075 | struct hlist_node hlist; | |
1076 | unsigned long ip; | |
1077 | }; | |
1078 | ||
1079 | struct ftrace_hash { | |
1080 | unsigned long size_bits; | |
1081 | struct hlist_head *buckets; | |
1082 | unsigned long count; | |
07fd5515 | 1083 | struct rcu_head rcu; |
b448c4e3 SR |
1084 | }; |
1085 | ||
33dc9b12 SR |
1086 | /* |
1087 | * We make these constant because no one should touch them, | |
1088 | * but they are used as the default "empty hash", to avoid allocating | |
1089 | * it all the time. These are in a read only section such that if | |
1090 | * anyone does try to modify it, it will cause an exception. | |
1091 | */ | |
1092 | static const struct hlist_head empty_buckets[1]; | |
1093 | static const struct ftrace_hash empty_hash = { | |
1094 | .buckets = (struct hlist_head *)empty_buckets, | |
1cf41dd7 | 1095 | }; |
33dc9b12 | 1096 | #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash) |
493762fc | 1097 | |
2b499381 | 1098 | static struct ftrace_ops global_ops = { |
f45948e8 | 1099 | .func = ftrace_stub, |
33dc9b12 SR |
1100 | .notrace_hash = EMPTY_HASH, |
1101 | .filter_hash = EMPTY_HASH, | |
4740974a | 1102 | .flags = FTRACE_OPS_FL_RECURSION_SAFE, |
f45948e8 SR |
1103 | }; |
1104 | ||
493762fc SR |
1105 | static DEFINE_MUTEX(ftrace_regex_lock); |
1106 | ||
1107 | struct ftrace_page { | |
1108 | struct ftrace_page *next; | |
a7900875 | 1109 | struct dyn_ftrace *records; |
493762fc | 1110 | int index; |
a7900875 | 1111 | int size; |
493762fc SR |
1112 | }; |
1113 | ||
85ae32ae SR |
1114 | static struct ftrace_page *ftrace_new_pgs; |
1115 | ||
a7900875 SR |
1116 | #define ENTRY_SIZE sizeof(struct dyn_ftrace) |
1117 | #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE) | |
493762fc SR |
1118 | |
1119 | /* estimate from running different kernels */ | |
1120 | #define NR_TO_INIT 10000 | |
1121 | ||
1122 | static struct ftrace_page *ftrace_pages_start; | |
1123 | static struct ftrace_page *ftrace_pages; | |
1124 | ||
06a51d93 SR |
1125 | static bool ftrace_hash_empty(struct ftrace_hash *hash) |
1126 | { | |
1127 | return !hash || !hash->count; | |
1128 | } | |
1129 | ||
b448c4e3 SR |
1130 | static struct ftrace_func_entry * |
1131 | ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
1132 | { | |
1133 | unsigned long key; | |
1134 | struct ftrace_func_entry *entry; | |
1135 | struct hlist_head *hhd; | |
1136 | struct hlist_node *n; | |
1137 | ||
06a51d93 | 1138 | if (ftrace_hash_empty(hash)) |
b448c4e3 SR |
1139 | return NULL; |
1140 | ||
1141 | if (hash->size_bits > 0) | |
1142 | key = hash_long(ip, hash->size_bits); | |
1143 | else | |
1144 | key = 0; | |
1145 | ||
1146 | hhd = &hash->buckets[key]; | |
1147 | ||
1148 | hlist_for_each_entry_rcu(entry, n, hhd, hlist) { | |
1149 | if (entry->ip == ip) | |
1150 | return entry; | |
1151 | } | |
1152 | return NULL; | |
1153 | } | |
1154 | ||
33dc9b12 SR |
1155 | static void __add_hash_entry(struct ftrace_hash *hash, |
1156 | struct ftrace_func_entry *entry) | |
b448c4e3 | 1157 | { |
b448c4e3 SR |
1158 | struct hlist_head *hhd; |
1159 | unsigned long key; | |
1160 | ||
b448c4e3 | 1161 | if (hash->size_bits) |
33dc9b12 | 1162 | key = hash_long(entry->ip, hash->size_bits); |
b448c4e3 SR |
1163 | else |
1164 | key = 0; | |
1165 | ||
b448c4e3 SR |
1166 | hhd = &hash->buckets[key]; |
1167 | hlist_add_head(&entry->hlist, hhd); | |
1168 | hash->count++; | |
33dc9b12 SR |
1169 | } |
1170 | ||
1171 | static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip) | |
1172 | { | |
1173 | struct ftrace_func_entry *entry; | |
1174 | ||
1175 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1176 | if (!entry) | |
1177 | return -ENOMEM; | |
1178 | ||
1179 | entry->ip = ip; | |
1180 | __add_hash_entry(hash, entry); | |
b448c4e3 SR |
1181 | |
1182 | return 0; | |
1183 | } | |
1184 | ||
1185 | static void | |
33dc9b12 | 1186 | free_hash_entry(struct ftrace_hash *hash, |
b448c4e3 SR |
1187 | struct ftrace_func_entry *entry) |
1188 | { | |
1189 | hlist_del(&entry->hlist); | |
1190 | kfree(entry); | |
1191 | hash->count--; | |
1192 | } | |
1193 | ||
33dc9b12 SR |
1194 | static void |
1195 | remove_hash_entry(struct ftrace_hash *hash, | |
1196 | struct ftrace_func_entry *entry) | |
1197 | { | |
1198 | hlist_del(&entry->hlist); | |
1199 | hash->count--; | |
1200 | } | |
1201 | ||
b448c4e3 SR |
1202 | static void ftrace_hash_clear(struct ftrace_hash *hash) |
1203 | { | |
1204 | struct hlist_head *hhd; | |
1205 | struct hlist_node *tp, *tn; | |
1206 | struct ftrace_func_entry *entry; | |
1207 | int size = 1 << hash->size_bits; | |
1208 | int i; | |
1209 | ||
33dc9b12 SR |
1210 | if (!hash->count) |
1211 | return; | |
1212 | ||
b448c4e3 SR |
1213 | for (i = 0; i < size; i++) { |
1214 | hhd = &hash->buckets[i]; | |
1215 | hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist) | |
33dc9b12 | 1216 | free_hash_entry(hash, entry); |
b448c4e3 SR |
1217 | } |
1218 | FTRACE_WARN_ON(hash->count); | |
1219 | } | |
1220 | ||
33dc9b12 SR |
1221 | static void free_ftrace_hash(struct ftrace_hash *hash) |
1222 | { | |
1223 | if (!hash || hash == EMPTY_HASH) | |
1224 | return; | |
1225 | ftrace_hash_clear(hash); | |
1226 | kfree(hash->buckets); | |
1227 | kfree(hash); | |
1228 | } | |
1229 | ||
07fd5515 SR |
1230 | static void __free_ftrace_hash_rcu(struct rcu_head *rcu) |
1231 | { | |
1232 | struct ftrace_hash *hash; | |
1233 | ||
1234 | hash = container_of(rcu, struct ftrace_hash, rcu); | |
1235 | free_ftrace_hash(hash); | |
1236 | } | |
1237 | ||
1238 | static void free_ftrace_hash_rcu(struct ftrace_hash *hash) | |
1239 | { | |
1240 | if (!hash || hash == EMPTY_HASH) | |
1241 | return; | |
1242 | call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu); | |
1243 | } | |
1244 | ||
5500fa51 JO |
1245 | void ftrace_free_filter(struct ftrace_ops *ops) |
1246 | { | |
1247 | free_ftrace_hash(ops->filter_hash); | |
1248 | free_ftrace_hash(ops->notrace_hash); | |
1249 | } | |
1250 | ||
33dc9b12 SR |
1251 | static struct ftrace_hash *alloc_ftrace_hash(int size_bits) |
1252 | { | |
1253 | struct ftrace_hash *hash; | |
1254 | int size; | |
1255 | ||
1256 | hash = kzalloc(sizeof(*hash), GFP_KERNEL); | |
1257 | if (!hash) | |
1258 | return NULL; | |
1259 | ||
1260 | size = 1 << size_bits; | |
47b0edcb | 1261 | hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL); |
33dc9b12 SR |
1262 | |
1263 | if (!hash->buckets) { | |
1264 | kfree(hash); | |
1265 | return NULL; | |
1266 | } | |
1267 | ||
1268 | hash->size_bits = size_bits; | |
1269 | ||
1270 | return hash; | |
1271 | } | |
1272 | ||
1273 | static struct ftrace_hash * | |
1274 | alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) | |
1275 | { | |
1276 | struct ftrace_func_entry *entry; | |
1277 | struct ftrace_hash *new_hash; | |
1278 | struct hlist_node *tp; | |
1279 | int size; | |
1280 | int ret; | |
1281 | int i; | |
1282 | ||
1283 | new_hash = alloc_ftrace_hash(size_bits); | |
1284 | if (!new_hash) | |
1285 | return NULL; | |
1286 | ||
1287 | /* Empty hash? */ | |
06a51d93 | 1288 | if (ftrace_hash_empty(hash)) |
33dc9b12 SR |
1289 | return new_hash; |
1290 | ||
1291 | size = 1 << hash->size_bits; | |
1292 | for (i = 0; i < size; i++) { | |
1293 | hlist_for_each_entry(entry, tp, &hash->buckets[i], hlist) { | |
1294 | ret = add_hash_entry(new_hash, entry->ip); | |
1295 | if (ret < 0) | |
1296 | goto free_hash; | |
1297 | } | |
1298 | } | |
1299 | ||
1300 | FTRACE_WARN_ON(new_hash->count != hash->count); | |
1301 | ||
1302 | return new_hash; | |
1303 | ||
1304 | free_hash: | |
1305 | free_ftrace_hash(new_hash); | |
1306 | return NULL; | |
1307 | } | |
1308 | ||
41fb61c2 SR |
1309 | static void |
1310 | ftrace_hash_rec_disable(struct ftrace_ops *ops, int filter_hash); | |
1311 | static void | |
1312 | ftrace_hash_rec_enable(struct ftrace_ops *ops, int filter_hash); | |
1313 | ||
33dc9b12 | 1314 | static int |
41fb61c2 SR |
1315 | ftrace_hash_move(struct ftrace_ops *ops, int enable, |
1316 | struct ftrace_hash **dst, struct ftrace_hash *src) | |
33dc9b12 SR |
1317 | { |
1318 | struct ftrace_func_entry *entry; | |
1319 | struct hlist_node *tp, *tn; | |
1320 | struct hlist_head *hhd; | |
07fd5515 SR |
1321 | struct ftrace_hash *old_hash; |
1322 | struct ftrace_hash *new_hash; | |
33dc9b12 SR |
1323 | unsigned long key; |
1324 | int size = src->count; | |
1325 | int bits = 0; | |
41fb61c2 | 1326 | int ret; |
33dc9b12 SR |
1327 | int i; |
1328 | ||
41fb61c2 SR |
1329 | /* |
1330 | * Remove the current set, update the hash and add | |
1331 | * them back. | |
1332 | */ | |
1333 | ftrace_hash_rec_disable(ops, enable); | |
1334 | ||
33dc9b12 SR |
1335 | /* |
1336 | * If the new source is empty, just free dst and assign it | |
1337 | * the empty_hash. | |
1338 | */ | |
1339 | if (!src->count) { | |
07fd5515 SR |
1340 | free_ftrace_hash_rcu(*dst); |
1341 | rcu_assign_pointer(*dst, EMPTY_HASH); | |
d4d34b98 SR |
1342 | /* still need to update the function records */ |
1343 | ret = 0; | |
1344 | goto out; | |
33dc9b12 SR |
1345 | } |
1346 | ||
33dc9b12 SR |
1347 | /* |
1348 | * Make the hash size about 1/2 the # found | |
1349 | */ | |
1350 | for (size /= 2; size; size >>= 1) | |
1351 | bits++; | |
1352 | ||
1353 | /* Don't allocate too much */ | |
1354 | if (bits > FTRACE_HASH_MAX_BITS) | |
1355 | bits = FTRACE_HASH_MAX_BITS; | |
1356 | ||
41fb61c2 | 1357 | ret = -ENOMEM; |
07fd5515 SR |
1358 | new_hash = alloc_ftrace_hash(bits); |
1359 | if (!new_hash) | |
41fb61c2 | 1360 | goto out; |
33dc9b12 SR |
1361 | |
1362 | size = 1 << src->size_bits; | |
1363 | for (i = 0; i < size; i++) { | |
1364 | hhd = &src->buckets[i]; | |
1365 | hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist) { | |
1366 | if (bits > 0) | |
1367 | key = hash_long(entry->ip, bits); | |
1368 | else | |
1369 | key = 0; | |
1370 | remove_hash_entry(src, entry); | |
07fd5515 | 1371 | __add_hash_entry(new_hash, entry); |
33dc9b12 SR |
1372 | } |
1373 | } | |
1374 | ||
07fd5515 SR |
1375 | old_hash = *dst; |
1376 | rcu_assign_pointer(*dst, new_hash); | |
1377 | free_ftrace_hash_rcu(old_hash); | |
1378 | ||
41fb61c2 SR |
1379 | ret = 0; |
1380 | out: | |
1381 | /* | |
1382 | * Enable regardless of ret: | |
1383 | * On success, we enable the new hash. | |
1384 | * On failure, we re-enable the original hash. | |
1385 | */ | |
1386 | ftrace_hash_rec_enable(ops, enable); | |
1387 | ||
1388 | return ret; | |
33dc9b12 SR |
1389 | } |
1390 | ||
b848914c SR |
1391 | /* |
1392 | * Test the hashes for this ops to see if we want to call | |
1393 | * the ops->func or not. | |
1394 | * | |
1395 | * It's a match if the ip is in the ops->filter_hash or | |
1396 | * the filter_hash does not exist or is empty, | |
1397 | * AND | |
1398 | * the ip is not in the ops->notrace_hash. | |
cdbe61bf SR |
1399 | * |
1400 | * This needs to be called with preemption disabled as | |
1401 | * the hashes are freed with call_rcu_sched(). | |
b848914c SR |
1402 | */ |
1403 | static int | |
1404 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip) | |
1405 | { | |
1406 | struct ftrace_hash *filter_hash; | |
1407 | struct ftrace_hash *notrace_hash; | |
1408 | int ret; | |
1409 | ||
b848914c SR |
1410 | filter_hash = rcu_dereference_raw(ops->filter_hash); |
1411 | notrace_hash = rcu_dereference_raw(ops->notrace_hash); | |
1412 | ||
06a51d93 | 1413 | if ((ftrace_hash_empty(filter_hash) || |
b848914c | 1414 | ftrace_lookup_ip(filter_hash, ip)) && |
06a51d93 | 1415 | (ftrace_hash_empty(notrace_hash) || |
b848914c SR |
1416 | !ftrace_lookup_ip(notrace_hash, ip))) |
1417 | ret = 1; | |
1418 | else | |
1419 | ret = 0; | |
b848914c SR |
1420 | |
1421 | return ret; | |
1422 | } | |
1423 | ||
493762fc SR |
1424 | /* |
1425 | * This is a double for. Do not use 'break' to break out of the loop, | |
1426 | * you must use a goto. | |
1427 | */ | |
1428 | #define do_for_each_ftrace_rec(pg, rec) \ | |
1429 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
1430 | int _____i; \ | |
1431 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
1432 | rec = &pg->records[_____i]; | |
1433 | ||
1434 | #define while_for_each_ftrace_rec() \ | |
1435 | } \ | |
1436 | } | |
1437 | ||
5855fead SR |
1438 | |
1439 | static int ftrace_cmp_recs(const void *a, const void *b) | |
1440 | { | |
a650e02a SR |
1441 | const struct dyn_ftrace *key = a; |
1442 | const struct dyn_ftrace *rec = b; | |
5855fead | 1443 | |
a650e02a | 1444 | if (key->flags < rec->ip) |
5855fead | 1445 | return -1; |
a650e02a SR |
1446 | if (key->ip >= rec->ip + MCOUNT_INSN_SIZE) |
1447 | return 1; | |
5855fead SR |
1448 | return 0; |
1449 | } | |
1450 | ||
f0cf973a | 1451 | static unsigned long ftrace_location_range(unsigned long start, unsigned long end) |
c88fd863 SR |
1452 | { |
1453 | struct ftrace_page *pg; | |
1454 | struct dyn_ftrace *rec; | |
5855fead | 1455 | struct dyn_ftrace key; |
c88fd863 | 1456 | |
a650e02a SR |
1457 | key.ip = start; |
1458 | key.flags = end; /* overload flags, as it is unsigned long */ | |
5855fead SR |
1459 | |
1460 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
a650e02a SR |
1461 | if (end < pg->records[0].ip || |
1462 | start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) | |
9644302e | 1463 | continue; |
5855fead SR |
1464 | rec = bsearch(&key, pg->records, pg->index, |
1465 | sizeof(struct dyn_ftrace), | |
1466 | ftrace_cmp_recs); | |
1467 | if (rec) | |
f0cf973a | 1468 | return rec->ip; |
5855fead | 1469 | } |
c88fd863 SR |
1470 | |
1471 | return 0; | |
1472 | } | |
1473 | ||
a650e02a SR |
1474 | /** |
1475 | * ftrace_location - return true if the ip giving is a traced location | |
1476 | * @ip: the instruction pointer to check | |
1477 | * | |
f0cf973a | 1478 | * Returns rec->ip if @ip given is a pointer to a ftrace location. |
a650e02a SR |
1479 | * That is, the instruction that is either a NOP or call to |
1480 | * the function tracer. It checks the ftrace internal tables to | |
1481 | * determine if the address belongs or not. | |
1482 | */ | |
f0cf973a | 1483 | unsigned long ftrace_location(unsigned long ip) |
a650e02a SR |
1484 | { |
1485 | return ftrace_location_range(ip, ip); | |
1486 | } | |
1487 | ||
1488 | /** | |
1489 | * ftrace_text_reserved - return true if range contains an ftrace location | |
1490 | * @start: start of range to search | |
1491 | * @end: end of range to search (inclusive). @end points to the last byte to check. | |
1492 | * | |
1493 | * Returns 1 if @start and @end contains a ftrace location. | |
1494 | * That is, the instruction that is either a NOP or call to | |
1495 | * the function tracer. It checks the ftrace internal tables to | |
1496 | * determine if the address belongs or not. | |
1497 | */ | |
1498 | int ftrace_text_reserved(void *start, void *end) | |
1499 | { | |
f0cf973a SR |
1500 | unsigned long ret; |
1501 | ||
1502 | ret = ftrace_location_range((unsigned long)start, | |
1503 | (unsigned long)end); | |
1504 | ||
1505 | return (int)!!ret; | |
a650e02a SR |
1506 | } |
1507 | ||
ed926f9b SR |
1508 | static void __ftrace_hash_rec_update(struct ftrace_ops *ops, |
1509 | int filter_hash, | |
1510 | bool inc) | |
1511 | { | |
1512 | struct ftrace_hash *hash; | |
1513 | struct ftrace_hash *other_hash; | |
1514 | struct ftrace_page *pg; | |
1515 | struct dyn_ftrace *rec; | |
1516 | int count = 0; | |
1517 | int all = 0; | |
1518 | ||
1519 | /* Only update if the ops has been registered */ | |
1520 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
1521 | return; | |
1522 | ||
1523 | /* | |
1524 | * In the filter_hash case: | |
1525 | * If the count is zero, we update all records. | |
1526 | * Otherwise we just update the items in the hash. | |
1527 | * | |
1528 | * In the notrace_hash case: | |
1529 | * We enable the update in the hash. | |
1530 | * As disabling notrace means enabling the tracing, | |
1531 | * and enabling notrace means disabling, the inc variable | |
1532 | * gets inversed. | |
1533 | */ | |
1534 | if (filter_hash) { | |
1535 | hash = ops->filter_hash; | |
1536 | other_hash = ops->notrace_hash; | |
06a51d93 | 1537 | if (ftrace_hash_empty(hash)) |
ed926f9b SR |
1538 | all = 1; |
1539 | } else { | |
1540 | inc = !inc; | |
1541 | hash = ops->notrace_hash; | |
1542 | other_hash = ops->filter_hash; | |
1543 | /* | |
1544 | * If the notrace hash has no items, | |
1545 | * then there's nothing to do. | |
1546 | */ | |
06a51d93 | 1547 | if (ftrace_hash_empty(hash)) |
ed926f9b SR |
1548 | return; |
1549 | } | |
1550 | ||
1551 | do_for_each_ftrace_rec(pg, rec) { | |
1552 | int in_other_hash = 0; | |
1553 | int in_hash = 0; | |
1554 | int match = 0; | |
1555 | ||
1556 | if (all) { | |
1557 | /* | |
1558 | * Only the filter_hash affects all records. | |
1559 | * Update if the record is not in the notrace hash. | |
1560 | */ | |
b848914c | 1561 | if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) |
ed926f9b SR |
1562 | match = 1; |
1563 | } else { | |
06a51d93 SR |
1564 | in_hash = !!ftrace_lookup_ip(hash, rec->ip); |
1565 | in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip); | |
ed926f9b SR |
1566 | |
1567 | /* | |
1568 | * | |
1569 | */ | |
1570 | if (filter_hash && in_hash && !in_other_hash) | |
1571 | match = 1; | |
1572 | else if (!filter_hash && in_hash && | |
06a51d93 | 1573 | (in_other_hash || ftrace_hash_empty(other_hash))) |
ed926f9b SR |
1574 | match = 1; |
1575 | } | |
1576 | if (!match) | |
1577 | continue; | |
1578 | ||
1579 | if (inc) { | |
1580 | rec->flags++; | |
1581 | if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == FTRACE_REF_MAX)) | |
1582 | return; | |
08f6fba5 SR |
1583 | /* |
1584 | * If any ops wants regs saved for this function | |
1585 | * then all ops will get saved regs. | |
1586 | */ | |
1587 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) | |
1588 | rec->flags |= FTRACE_FL_REGS; | |
ed926f9b SR |
1589 | } else { |
1590 | if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == 0)) | |
1591 | return; | |
1592 | rec->flags--; | |
1593 | } | |
1594 | count++; | |
1595 | /* Shortcut, if we handled all records, we are done. */ | |
1596 | if (!all && count == hash->count) | |
1597 | return; | |
1598 | } while_for_each_ftrace_rec(); | |
1599 | } | |
1600 | ||
1601 | static void ftrace_hash_rec_disable(struct ftrace_ops *ops, | |
1602 | int filter_hash) | |
1603 | { | |
1604 | __ftrace_hash_rec_update(ops, filter_hash, 0); | |
1605 | } | |
1606 | ||
1607 | static void ftrace_hash_rec_enable(struct ftrace_ops *ops, | |
1608 | int filter_hash) | |
1609 | { | |
1610 | __ftrace_hash_rec_update(ops, filter_hash, 1); | |
1611 | } | |
1612 | ||
b17e8a37 SR |
1613 | static void print_ip_ins(const char *fmt, unsigned char *p) |
1614 | { | |
1615 | int i; | |
1616 | ||
1617 | printk(KERN_CONT "%s", fmt); | |
1618 | ||
1619 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
1620 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
1621 | } | |
1622 | ||
c88fd863 SR |
1623 | /** |
1624 | * ftrace_bug - report and shutdown function tracer | |
1625 | * @failed: The failed type (EFAULT, EINVAL, EPERM) | |
1626 | * @ip: The address that failed | |
1627 | * | |
1628 | * The arch code that enables or disables the function tracing | |
1629 | * can call ftrace_bug() when it has detected a problem in | |
1630 | * modifying the code. @failed should be one of either: | |
1631 | * EFAULT - if the problem happens on reading the @ip address | |
1632 | * EINVAL - if what is read at @ip is not what was expected | |
1633 | * EPERM - if the problem happens on writting to the @ip address | |
1634 | */ | |
1635 | void ftrace_bug(int failed, unsigned long ip) | |
b17e8a37 SR |
1636 | { |
1637 | switch (failed) { | |
1638 | case -EFAULT: | |
1639 | FTRACE_WARN_ON_ONCE(1); | |
1640 | pr_info("ftrace faulted on modifying "); | |
1641 | print_ip_sym(ip); | |
1642 | break; | |
1643 | case -EINVAL: | |
1644 | FTRACE_WARN_ON_ONCE(1); | |
1645 | pr_info("ftrace failed to modify "); | |
1646 | print_ip_sym(ip); | |
b17e8a37 | 1647 | print_ip_ins(" actual: ", (unsigned char *)ip); |
b17e8a37 SR |
1648 | printk(KERN_CONT "\n"); |
1649 | break; | |
1650 | case -EPERM: | |
1651 | FTRACE_WARN_ON_ONCE(1); | |
1652 | pr_info("ftrace faulted on writing "); | |
1653 | print_ip_sym(ip); | |
1654 | break; | |
1655 | default: | |
1656 | FTRACE_WARN_ON_ONCE(1); | |
1657 | pr_info("ftrace faulted on unknown error "); | |
1658 | print_ip_sym(ip); | |
1659 | } | |
1660 | } | |
1661 | ||
c88fd863 | 1662 | static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update) |
5072c59f | 1663 | { |
64fbcd16 | 1664 | unsigned long flag = 0UL; |
e7d3737e | 1665 | |
982c350b | 1666 | /* |
30fb6aa7 | 1667 | * If we are updating calls: |
982c350b | 1668 | * |
ed926f9b SR |
1669 | * If the record has a ref count, then we need to enable it |
1670 | * because someone is using it. | |
982c350b | 1671 | * |
ed926f9b SR |
1672 | * Otherwise we make sure its disabled. |
1673 | * | |
30fb6aa7 | 1674 | * If we are disabling calls, then disable all records that |
ed926f9b | 1675 | * are enabled. |
982c350b | 1676 | */ |
c88fd863 | 1677 | if (enable && (rec->flags & ~FTRACE_FL_MASK)) |
ed926f9b | 1678 | flag = FTRACE_FL_ENABLED; |
982c350b | 1679 | |
08f6fba5 SR |
1680 | /* |
1681 | * If enabling and the REGS flag does not match the REGS_EN, then | |
1682 | * do not ignore this record. Set flags to fail the compare against | |
1683 | * ENABLED. | |
1684 | */ | |
1685 | if (flag && | |
1686 | (!(rec->flags & FTRACE_FL_REGS) != !(rec->flags & FTRACE_FL_REGS_EN))) | |
1687 | flag |= FTRACE_FL_REGS; | |
1688 | ||
64fbcd16 XG |
1689 | /* If the state of this record hasn't changed, then do nothing */ |
1690 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
c88fd863 | 1691 | return FTRACE_UPDATE_IGNORE; |
982c350b | 1692 | |
64fbcd16 | 1693 | if (flag) { |
08f6fba5 SR |
1694 | /* Save off if rec is being enabled (for return value) */ |
1695 | flag ^= rec->flags & FTRACE_FL_ENABLED; | |
1696 | ||
1697 | if (update) { | |
c88fd863 | 1698 | rec->flags |= FTRACE_FL_ENABLED; |
08f6fba5 SR |
1699 | if (flag & FTRACE_FL_REGS) { |
1700 | if (rec->flags & FTRACE_FL_REGS) | |
1701 | rec->flags |= FTRACE_FL_REGS_EN; | |
1702 | else | |
1703 | rec->flags &= ~FTRACE_FL_REGS_EN; | |
1704 | } | |
1705 | } | |
1706 | ||
1707 | /* | |
1708 | * If this record is being updated from a nop, then | |
1709 | * return UPDATE_MAKE_CALL. | |
1710 | * Otherwise, if the EN flag is set, then return | |
1711 | * UPDATE_MODIFY_CALL_REGS to tell the caller to convert | |
1712 | * from the non-save regs, to a save regs function. | |
1713 | * Otherwise, | |
1714 | * return UPDATE_MODIFY_CALL to tell the caller to convert | |
1715 | * from the save regs, to a non-save regs function. | |
1716 | */ | |
1717 | if (flag & FTRACE_FL_ENABLED) | |
1718 | return FTRACE_UPDATE_MAKE_CALL; | |
1719 | else if (rec->flags & FTRACE_FL_REGS_EN) | |
1720 | return FTRACE_UPDATE_MODIFY_CALL_REGS; | |
1721 | else | |
1722 | return FTRACE_UPDATE_MODIFY_CALL; | |
c88fd863 SR |
1723 | } |
1724 | ||
08f6fba5 SR |
1725 | if (update) { |
1726 | /* If there's no more users, clear all flags */ | |
1727 | if (!(rec->flags & ~FTRACE_FL_MASK)) | |
1728 | rec->flags = 0; | |
1729 | else | |
1730 | /* Just disable the record (keep REGS state) */ | |
1731 | rec->flags &= ~FTRACE_FL_ENABLED; | |
1732 | } | |
c88fd863 SR |
1733 | |
1734 | return FTRACE_UPDATE_MAKE_NOP; | |
1735 | } | |
1736 | ||
1737 | /** | |
1738 | * ftrace_update_record, set a record that now is tracing or not | |
1739 | * @rec: the record to update | |
1740 | * @enable: set to 1 if the record is tracing, zero to force disable | |
1741 | * | |
1742 | * The records that represent all functions that can be traced need | |
1743 | * to be updated when tracing has been enabled. | |
1744 | */ | |
1745 | int ftrace_update_record(struct dyn_ftrace *rec, int enable) | |
1746 | { | |
1747 | return ftrace_check_record(rec, enable, 1); | |
1748 | } | |
1749 | ||
1750 | /** | |
1751 | * ftrace_test_record, check if the record has been enabled or not | |
1752 | * @rec: the record to test | |
1753 | * @enable: set to 1 to check if enabled, 0 if it is disabled | |
1754 | * | |
1755 | * The arch code may need to test if a record is already set to | |
1756 | * tracing to determine how to modify the function code that it | |
1757 | * represents. | |
1758 | */ | |
1759 | int ftrace_test_record(struct dyn_ftrace *rec, int enable) | |
1760 | { | |
1761 | return ftrace_check_record(rec, enable, 0); | |
1762 | } | |
1763 | ||
1764 | static int | |
1765 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) | |
1766 | { | |
08f6fba5 | 1767 | unsigned long ftrace_old_addr; |
c88fd863 SR |
1768 | unsigned long ftrace_addr; |
1769 | int ret; | |
1770 | ||
c88fd863 SR |
1771 | ret = ftrace_update_record(rec, enable); |
1772 | ||
08f6fba5 SR |
1773 | if (rec->flags & FTRACE_FL_REGS) |
1774 | ftrace_addr = (unsigned long)FTRACE_REGS_ADDR; | |
1775 | else | |
1776 | ftrace_addr = (unsigned long)FTRACE_ADDR; | |
1777 | ||
c88fd863 SR |
1778 | switch (ret) { |
1779 | case FTRACE_UPDATE_IGNORE: | |
1780 | return 0; | |
1781 | ||
1782 | case FTRACE_UPDATE_MAKE_CALL: | |
64fbcd16 | 1783 | return ftrace_make_call(rec, ftrace_addr); |
c88fd863 SR |
1784 | |
1785 | case FTRACE_UPDATE_MAKE_NOP: | |
1786 | return ftrace_make_nop(NULL, rec, ftrace_addr); | |
08f6fba5 SR |
1787 | |
1788 | case FTRACE_UPDATE_MODIFY_CALL_REGS: | |
1789 | case FTRACE_UPDATE_MODIFY_CALL: | |
1790 | if (rec->flags & FTRACE_FL_REGS) | |
1791 | ftrace_old_addr = (unsigned long)FTRACE_ADDR; | |
1792 | else | |
1793 | ftrace_old_addr = (unsigned long)FTRACE_REGS_ADDR; | |
1794 | ||
1795 | return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr); | |
5072c59f SR |
1796 | } |
1797 | ||
c88fd863 | 1798 | return -1; /* unknow ftrace bug */ |
5072c59f SR |
1799 | } |
1800 | ||
e4f5d544 | 1801 | void __weak ftrace_replace_code(int enable) |
3c1720f0 | 1802 | { |
3c1720f0 SR |
1803 | struct dyn_ftrace *rec; |
1804 | struct ftrace_page *pg; | |
6a24a244 | 1805 | int failed; |
3c1720f0 | 1806 | |
45a4a237 SR |
1807 | if (unlikely(ftrace_disabled)) |
1808 | return; | |
1809 | ||
265c831c | 1810 | do_for_each_ftrace_rec(pg, rec) { |
e4f5d544 | 1811 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 1812 | if (failed) { |
3279ba37 SR |
1813 | ftrace_bug(failed, rec->ip); |
1814 | /* Stop processing */ | |
1815 | return; | |
3c1720f0 | 1816 | } |
265c831c | 1817 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
1818 | } |
1819 | ||
c88fd863 SR |
1820 | struct ftrace_rec_iter { |
1821 | struct ftrace_page *pg; | |
1822 | int index; | |
1823 | }; | |
1824 | ||
1825 | /** | |
1826 | * ftrace_rec_iter_start, start up iterating over traced functions | |
1827 | * | |
1828 | * Returns an iterator handle that is used to iterate over all | |
1829 | * the records that represent address locations where functions | |
1830 | * are traced. | |
1831 | * | |
1832 | * May return NULL if no records are available. | |
1833 | */ | |
1834 | struct ftrace_rec_iter *ftrace_rec_iter_start(void) | |
1835 | { | |
1836 | /* | |
1837 | * We only use a single iterator. | |
1838 | * Protected by the ftrace_lock mutex. | |
1839 | */ | |
1840 | static struct ftrace_rec_iter ftrace_rec_iter; | |
1841 | struct ftrace_rec_iter *iter = &ftrace_rec_iter; | |
1842 | ||
1843 | iter->pg = ftrace_pages_start; | |
1844 | iter->index = 0; | |
1845 | ||
1846 | /* Could have empty pages */ | |
1847 | while (iter->pg && !iter->pg->index) | |
1848 | iter->pg = iter->pg->next; | |
1849 | ||
1850 | if (!iter->pg) | |
1851 | return NULL; | |
1852 | ||
1853 | return iter; | |
1854 | } | |
1855 | ||
1856 | /** | |
1857 | * ftrace_rec_iter_next, get the next record to process. | |
1858 | * @iter: The handle to the iterator. | |
1859 | * | |
1860 | * Returns the next iterator after the given iterator @iter. | |
1861 | */ | |
1862 | struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) | |
1863 | { | |
1864 | iter->index++; | |
1865 | ||
1866 | if (iter->index >= iter->pg->index) { | |
1867 | iter->pg = iter->pg->next; | |
1868 | iter->index = 0; | |
1869 | ||
1870 | /* Could have empty pages */ | |
1871 | while (iter->pg && !iter->pg->index) | |
1872 | iter->pg = iter->pg->next; | |
1873 | } | |
1874 | ||
1875 | if (!iter->pg) | |
1876 | return NULL; | |
1877 | ||
1878 | return iter; | |
1879 | } | |
1880 | ||
1881 | /** | |
1882 | * ftrace_rec_iter_record, get the record at the iterator location | |
1883 | * @iter: The current iterator location | |
1884 | * | |
1885 | * Returns the record that the current @iter is at. | |
1886 | */ | |
1887 | struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) | |
1888 | { | |
1889 | return &iter->pg->records[iter->index]; | |
1890 | } | |
1891 | ||
492a7ea5 | 1892 | static int |
31e88909 | 1893 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 SR |
1894 | { |
1895 | unsigned long ip; | |
593eb8a2 | 1896 | int ret; |
3c1720f0 SR |
1897 | |
1898 | ip = rec->ip; | |
1899 | ||
45a4a237 SR |
1900 | if (unlikely(ftrace_disabled)) |
1901 | return 0; | |
1902 | ||
25aac9dc | 1903 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 1904 | if (ret) { |
31e88909 | 1905 | ftrace_bug(ret, ip); |
492a7ea5 | 1906 | return 0; |
37ad5084 | 1907 | } |
492a7ea5 | 1908 | return 1; |
3c1720f0 SR |
1909 | } |
1910 | ||
000ab691 SR |
1911 | /* |
1912 | * archs can override this function if they must do something | |
1913 | * before the modifying code is performed. | |
1914 | */ | |
1915 | int __weak ftrace_arch_code_modify_prepare(void) | |
1916 | { | |
1917 | return 0; | |
1918 | } | |
1919 | ||
1920 | /* | |
1921 | * archs can override this function if they must do something | |
1922 | * after the modifying code is performed. | |
1923 | */ | |
1924 | int __weak ftrace_arch_code_modify_post_process(void) | |
1925 | { | |
1926 | return 0; | |
1927 | } | |
1928 | ||
8ed3e2cf | 1929 | void ftrace_modify_all_code(int command) |
3d083395 | 1930 | { |
8ed3e2cf | 1931 | if (command & FTRACE_UPDATE_CALLS) |
d61f82d0 | 1932 | ftrace_replace_code(1); |
8ed3e2cf | 1933 | else if (command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
1934 | ftrace_replace_code(0); |
1935 | ||
8ed3e2cf | 1936 | if (command & FTRACE_UPDATE_TRACE_FUNC) |
d61f82d0 SR |
1937 | ftrace_update_ftrace_func(ftrace_trace_function); |
1938 | ||
8ed3e2cf | 1939 | if (command & FTRACE_START_FUNC_RET) |
5a45cfe1 | 1940 | ftrace_enable_ftrace_graph_caller(); |
8ed3e2cf | 1941 | else if (command & FTRACE_STOP_FUNC_RET) |
5a45cfe1 | 1942 | ftrace_disable_ftrace_graph_caller(); |
8ed3e2cf SR |
1943 | } |
1944 | ||
1945 | static int __ftrace_modify_code(void *data) | |
1946 | { | |
1947 | int *command = data; | |
1948 | ||
1949 | ftrace_modify_all_code(*command); | |
5a45cfe1 | 1950 | |
d61f82d0 | 1951 | return 0; |
3d083395 SR |
1952 | } |
1953 | ||
c88fd863 SR |
1954 | /** |
1955 | * ftrace_run_stop_machine, go back to the stop machine method | |
1956 | * @command: The command to tell ftrace what to do | |
1957 | * | |
1958 | * If an arch needs to fall back to the stop machine method, the | |
1959 | * it can call this function. | |
1960 | */ | |
1961 | void ftrace_run_stop_machine(int command) | |
1962 | { | |
1963 | stop_machine(__ftrace_modify_code, &command, NULL); | |
1964 | } | |
1965 | ||
1966 | /** | |
1967 | * arch_ftrace_update_code, modify the code to trace or not trace | |
1968 | * @command: The command that needs to be done | |
1969 | * | |
1970 | * Archs can override this function if it does not need to | |
1971 | * run stop_machine() to modify code. | |
1972 | */ | |
1973 | void __weak arch_ftrace_update_code(int command) | |
1974 | { | |
1975 | ftrace_run_stop_machine(command); | |
1976 | } | |
1977 | ||
e309b41d | 1978 | static void ftrace_run_update_code(int command) |
3d083395 | 1979 | { |
000ab691 SR |
1980 | int ret; |
1981 | ||
1982 | ret = ftrace_arch_code_modify_prepare(); | |
1983 | FTRACE_WARN_ON(ret); | |
1984 | if (ret) | |
1985 | return; | |
c88fd863 SR |
1986 | /* |
1987 | * Do not call function tracer while we update the code. | |
1988 | * We are in stop machine. | |
1989 | */ | |
1990 | function_trace_stop++; | |
000ab691 | 1991 | |
c88fd863 SR |
1992 | /* |
1993 | * By default we use stop_machine() to modify the code. | |
1994 | * But archs can do what ever they want as long as it | |
1995 | * is safe. The stop_machine() is the safest, but also | |
1996 | * produces the most overhead. | |
1997 | */ | |
1998 | arch_ftrace_update_code(command); | |
1999 | ||
c88fd863 | 2000 | function_trace_stop--; |
000ab691 SR |
2001 | |
2002 | ret = ftrace_arch_code_modify_post_process(); | |
2003 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
2004 | } |
2005 | ||
d61f82d0 | 2006 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 2007 | static int ftrace_start_up; |
b848914c | 2008 | static int global_start_up; |
df4fc315 SR |
2009 | |
2010 | static void ftrace_startup_enable(int command) | |
2011 | { | |
2012 | if (saved_ftrace_func != ftrace_trace_function) { | |
2013 | saved_ftrace_func = ftrace_trace_function; | |
2014 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2015 | } | |
2016 | ||
2017 | if (!command || !ftrace_enabled) | |
2018 | return; | |
2019 | ||
2020 | ftrace_run_update_code(command); | |
2021 | } | |
d61f82d0 | 2022 | |
a1cd6173 | 2023 | static int ftrace_startup(struct ftrace_ops *ops, int command) |
3d083395 | 2024 | { |
b848914c SR |
2025 | bool hash_enable = true; |
2026 | ||
4eebcc81 | 2027 | if (unlikely(ftrace_disabled)) |
a1cd6173 | 2028 | return -ENODEV; |
4eebcc81 | 2029 | |
60a7ecf4 | 2030 | ftrace_start_up++; |
30fb6aa7 | 2031 | command |= FTRACE_UPDATE_CALLS; |
d61f82d0 | 2032 | |
b848914c SR |
2033 | /* ops marked global share the filter hashes */ |
2034 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { | |
2035 | ops = &global_ops; | |
2036 | /* Don't update hash if global is already set */ | |
2037 | if (global_start_up) | |
2038 | hash_enable = false; | |
2039 | global_start_up++; | |
2040 | } | |
2041 | ||
ed926f9b | 2042 | ops->flags |= FTRACE_OPS_FL_ENABLED; |
b848914c | 2043 | if (hash_enable) |
ed926f9b SR |
2044 | ftrace_hash_rec_enable(ops, 1); |
2045 | ||
df4fc315 | 2046 | ftrace_startup_enable(command); |
a1cd6173 SR |
2047 | |
2048 | return 0; | |
3d083395 SR |
2049 | } |
2050 | ||
bd69c30b | 2051 | static void ftrace_shutdown(struct ftrace_ops *ops, int command) |
3d083395 | 2052 | { |
b848914c SR |
2053 | bool hash_disable = true; |
2054 | ||
4eebcc81 SR |
2055 | if (unlikely(ftrace_disabled)) |
2056 | return; | |
2057 | ||
60a7ecf4 | 2058 | ftrace_start_up--; |
9ea1a153 FW |
2059 | /* |
2060 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
2061 | * critical but the ftrace_call callers may be never nopped again after | |
2062 | * further ftrace uses. | |
2063 | */ | |
2064 | WARN_ON_ONCE(ftrace_start_up < 0); | |
2065 | ||
b848914c SR |
2066 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { |
2067 | ops = &global_ops; | |
2068 | global_start_up--; | |
2069 | WARN_ON_ONCE(global_start_up < 0); | |
2070 | /* Don't update hash if global still has users */ | |
2071 | if (global_start_up) { | |
2072 | WARN_ON_ONCE(!ftrace_start_up); | |
2073 | hash_disable = false; | |
2074 | } | |
2075 | } | |
2076 | ||
2077 | if (hash_disable) | |
ed926f9b SR |
2078 | ftrace_hash_rec_disable(ops, 1); |
2079 | ||
b848914c | 2080 | if (ops != &global_ops || !global_start_up) |
ed926f9b | 2081 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
b848914c | 2082 | |
30fb6aa7 | 2083 | command |= FTRACE_UPDATE_CALLS; |
3d083395 | 2084 | |
d61f82d0 SR |
2085 | if (saved_ftrace_func != ftrace_trace_function) { |
2086 | saved_ftrace_func = ftrace_trace_function; | |
2087 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2088 | } | |
3d083395 | 2089 | |
d61f82d0 | 2090 | if (!command || !ftrace_enabled) |
e6ea44e9 | 2091 | return; |
d61f82d0 SR |
2092 | |
2093 | ftrace_run_update_code(command); | |
3d083395 SR |
2094 | } |
2095 | ||
e309b41d | 2096 | static void ftrace_startup_sysctl(void) |
b0fc494f | 2097 | { |
4eebcc81 SR |
2098 | if (unlikely(ftrace_disabled)) |
2099 | return; | |
2100 | ||
d61f82d0 SR |
2101 | /* Force update next time */ |
2102 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
2103 | /* ftrace_start_up is true if we want ftrace running */ |
2104 | if (ftrace_start_up) | |
30fb6aa7 | 2105 | ftrace_run_update_code(FTRACE_UPDATE_CALLS); |
b0fc494f SR |
2106 | } |
2107 | ||
e309b41d | 2108 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 2109 | { |
4eebcc81 SR |
2110 | if (unlikely(ftrace_disabled)) |
2111 | return; | |
2112 | ||
60a7ecf4 SR |
2113 | /* ftrace_start_up is true if ftrace is running */ |
2114 | if (ftrace_start_up) | |
79e406d7 | 2115 | ftrace_run_update_code(FTRACE_DISABLE_CALLS); |
b0fc494f SR |
2116 | } |
2117 | ||
3d083395 SR |
2118 | static cycle_t ftrace_update_time; |
2119 | static unsigned long ftrace_update_cnt; | |
2120 | unsigned long ftrace_update_tot_cnt; | |
2121 | ||
f7bc8b61 SR |
2122 | static int ops_traces_mod(struct ftrace_ops *ops) |
2123 | { | |
2124 | struct ftrace_hash *hash; | |
2125 | ||
2126 | hash = ops->filter_hash; | |
06a51d93 | 2127 | return ftrace_hash_empty(hash); |
f7bc8b61 SR |
2128 | } |
2129 | ||
31e88909 | 2130 | static int ftrace_update_code(struct module *mod) |
3d083395 | 2131 | { |
85ae32ae | 2132 | struct ftrace_page *pg; |
e94142a6 | 2133 | struct dyn_ftrace *p; |
f22f9a89 | 2134 | cycle_t start, stop; |
f7bc8b61 | 2135 | unsigned long ref = 0; |
85ae32ae | 2136 | int i; |
f7bc8b61 SR |
2137 | |
2138 | /* | |
2139 | * When adding a module, we need to check if tracers are | |
2140 | * currently enabled and if they are set to trace all functions. | |
2141 | * If they are, we need to enable the module functions as well | |
2142 | * as update the reference counts for those function records. | |
2143 | */ | |
2144 | if (mod) { | |
2145 | struct ftrace_ops *ops; | |
2146 | ||
2147 | for (ops = ftrace_ops_list; | |
2148 | ops != &ftrace_list_end; ops = ops->next) { | |
2149 | if (ops->flags & FTRACE_OPS_FL_ENABLED && | |
2150 | ops_traces_mod(ops)) | |
2151 | ref++; | |
2152 | } | |
2153 | } | |
3d083395 | 2154 | |
750ed1a4 | 2155 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
2156 | ftrace_update_cnt = 0; |
2157 | ||
85ae32ae | 2158 | for (pg = ftrace_new_pgs; pg; pg = pg->next) { |
3d083395 | 2159 | |
85ae32ae SR |
2160 | for (i = 0; i < pg->index; i++) { |
2161 | /* If something went wrong, bail without enabling anything */ | |
2162 | if (unlikely(ftrace_disabled)) | |
2163 | return -1; | |
f22f9a89 | 2164 | |
85ae32ae SR |
2165 | p = &pg->records[i]; |
2166 | p->flags = ref; | |
f22f9a89 | 2167 | |
85ae32ae SR |
2168 | /* |
2169 | * Do the initial record conversion from mcount jump | |
2170 | * to the NOP instructions. | |
2171 | */ | |
2172 | if (!ftrace_code_disable(mod, p)) | |
2173 | break; | |
5cb084bb | 2174 | |
85ae32ae | 2175 | ftrace_update_cnt++; |
5cb084bb | 2176 | |
85ae32ae SR |
2177 | /* |
2178 | * If the tracing is enabled, go ahead and enable the record. | |
2179 | * | |
2180 | * The reason not to enable the record immediatelly is the | |
2181 | * inherent check of ftrace_make_nop/ftrace_make_call for | |
2182 | * correct previous instructions. Making first the NOP | |
2183 | * conversion puts the module to the correct state, thus | |
2184 | * passing the ftrace_make_call check. | |
2185 | */ | |
2186 | if (ftrace_start_up && ref) { | |
2187 | int failed = __ftrace_replace_code(p, 1); | |
2188 | if (failed) | |
2189 | ftrace_bug(failed, p->ip); | |
2190 | } | |
5cb084bb | 2191 | } |
3d083395 SR |
2192 | } |
2193 | ||
85ae32ae SR |
2194 | ftrace_new_pgs = NULL; |
2195 | ||
750ed1a4 | 2196 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
2197 | ftrace_update_time = stop - start; |
2198 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
2199 | ||
16444a8a ACM |
2200 | return 0; |
2201 | } | |
2202 | ||
a7900875 | 2203 | static int ftrace_allocate_records(struct ftrace_page *pg, int count) |
3c1720f0 | 2204 | { |
a7900875 | 2205 | int order; |
3c1720f0 | 2206 | int cnt; |
3c1720f0 | 2207 | |
a7900875 SR |
2208 | if (WARN_ON(!count)) |
2209 | return -EINVAL; | |
2210 | ||
2211 | order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE)); | |
3c1720f0 SR |
2212 | |
2213 | /* | |
a7900875 SR |
2214 | * We want to fill as much as possible. No more than a page |
2215 | * may be empty. | |
3c1720f0 | 2216 | */ |
a7900875 SR |
2217 | while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE) |
2218 | order--; | |
3c1720f0 | 2219 | |
a7900875 SR |
2220 | again: |
2221 | pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order); | |
3c1720f0 | 2222 | |
a7900875 SR |
2223 | if (!pg->records) { |
2224 | /* if we can't allocate this size, try something smaller */ | |
2225 | if (!order) | |
2226 | return -ENOMEM; | |
2227 | order >>= 1; | |
2228 | goto again; | |
2229 | } | |
3c1720f0 | 2230 | |
a7900875 SR |
2231 | cnt = (PAGE_SIZE << order) / ENTRY_SIZE; |
2232 | pg->size = cnt; | |
3c1720f0 | 2233 | |
a7900875 SR |
2234 | if (cnt > count) |
2235 | cnt = count; | |
2236 | ||
2237 | return cnt; | |
2238 | } | |
2239 | ||
2240 | static struct ftrace_page * | |
2241 | ftrace_allocate_pages(unsigned long num_to_init) | |
2242 | { | |
2243 | struct ftrace_page *start_pg; | |
2244 | struct ftrace_page *pg; | |
2245 | int order; | |
2246 | int cnt; | |
2247 | ||
2248 | if (!num_to_init) | |
2249 | return 0; | |
2250 | ||
2251 | start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL); | |
2252 | if (!pg) | |
2253 | return NULL; | |
2254 | ||
2255 | /* | |
2256 | * Try to allocate as much as possible in one continues | |
2257 | * location that fills in all of the space. We want to | |
2258 | * waste as little space as possible. | |
2259 | */ | |
2260 | for (;;) { | |
2261 | cnt = ftrace_allocate_records(pg, num_to_init); | |
2262 | if (cnt < 0) | |
2263 | goto free_pages; | |
2264 | ||
2265 | num_to_init -= cnt; | |
2266 | if (!num_to_init) | |
3c1720f0 SR |
2267 | break; |
2268 | ||
a7900875 SR |
2269 | pg->next = kzalloc(sizeof(*pg), GFP_KERNEL); |
2270 | if (!pg->next) | |
2271 | goto free_pages; | |
2272 | ||
3c1720f0 SR |
2273 | pg = pg->next; |
2274 | } | |
2275 | ||
a7900875 SR |
2276 | return start_pg; |
2277 | ||
2278 | free_pages: | |
2279 | while (start_pg) { | |
2280 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); | |
2281 | free_pages((unsigned long)pg->records, order); | |
2282 | start_pg = pg->next; | |
2283 | kfree(pg); | |
2284 | pg = start_pg; | |
2285 | } | |
2286 | pr_info("ftrace: FAILED to allocate memory for functions\n"); | |
2287 | return NULL; | |
2288 | } | |
2289 | ||
2290 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) | |
2291 | { | |
2292 | int cnt; | |
2293 | ||
2294 | if (!num_to_init) { | |
2295 | pr_info("ftrace: No functions to be traced?\n"); | |
2296 | return -1; | |
2297 | } | |
2298 | ||
2299 | cnt = num_to_init / ENTRIES_PER_PAGE; | |
2300 | pr_info("ftrace: allocating %ld entries in %d pages\n", | |
2301 | num_to_init, cnt + 1); | |
2302 | ||
3c1720f0 SR |
2303 | return 0; |
2304 | } | |
2305 | ||
5072c59f SR |
2306 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ |
2307 | ||
2308 | struct ftrace_iterator { | |
98c4fd04 | 2309 | loff_t pos; |
4aeb6967 SR |
2310 | loff_t func_pos; |
2311 | struct ftrace_page *pg; | |
2312 | struct dyn_ftrace *func; | |
2313 | struct ftrace_func_probe *probe; | |
2314 | struct trace_parser parser; | |
1cf41dd7 | 2315 | struct ftrace_hash *hash; |
33dc9b12 | 2316 | struct ftrace_ops *ops; |
4aeb6967 SR |
2317 | int hidx; |
2318 | int idx; | |
2319 | unsigned flags; | |
5072c59f SR |
2320 | }; |
2321 | ||
8fc0c701 | 2322 | static void * |
4aeb6967 | 2323 | t_hash_next(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
2324 | { |
2325 | struct ftrace_iterator *iter = m->private; | |
4aeb6967 | 2326 | struct hlist_node *hnd = NULL; |
8fc0c701 SR |
2327 | struct hlist_head *hhd; |
2328 | ||
8fc0c701 | 2329 | (*pos)++; |
98c4fd04 | 2330 | iter->pos = *pos; |
8fc0c701 | 2331 | |
4aeb6967 SR |
2332 | if (iter->probe) |
2333 | hnd = &iter->probe->node; | |
8fc0c701 SR |
2334 | retry: |
2335 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
2336 | return NULL; | |
2337 | ||
2338 | hhd = &ftrace_func_hash[iter->hidx]; | |
2339 | ||
2340 | if (hlist_empty(hhd)) { | |
2341 | iter->hidx++; | |
2342 | hnd = NULL; | |
2343 | goto retry; | |
2344 | } | |
2345 | ||
2346 | if (!hnd) | |
2347 | hnd = hhd->first; | |
2348 | else { | |
2349 | hnd = hnd->next; | |
2350 | if (!hnd) { | |
2351 | iter->hidx++; | |
2352 | goto retry; | |
2353 | } | |
2354 | } | |
2355 | ||
4aeb6967 SR |
2356 | if (WARN_ON_ONCE(!hnd)) |
2357 | return NULL; | |
2358 | ||
2359 | iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node); | |
2360 | ||
2361 | return iter; | |
8fc0c701 SR |
2362 | } |
2363 | ||
2364 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
2365 | { | |
2366 | struct ftrace_iterator *iter = m->private; | |
2367 | void *p = NULL; | |
d82d6244 LZ |
2368 | loff_t l; |
2369 | ||
69a3083c SR |
2370 | if (!(iter->flags & FTRACE_ITER_DO_HASH)) |
2371 | return NULL; | |
2372 | ||
2bccfffd SR |
2373 | if (iter->func_pos > *pos) |
2374 | return NULL; | |
8fc0c701 | 2375 | |
d82d6244 | 2376 | iter->hidx = 0; |
2bccfffd | 2377 | for (l = 0; l <= (*pos - iter->func_pos); ) { |
4aeb6967 | 2378 | p = t_hash_next(m, &l); |
d82d6244 LZ |
2379 | if (!p) |
2380 | break; | |
2381 | } | |
4aeb6967 SR |
2382 | if (!p) |
2383 | return NULL; | |
2384 | ||
98c4fd04 SR |
2385 | /* Only set this if we have an item */ |
2386 | iter->flags |= FTRACE_ITER_HASH; | |
2387 | ||
4aeb6967 | 2388 | return iter; |
8fc0c701 SR |
2389 | } |
2390 | ||
4aeb6967 SR |
2391 | static int |
2392 | t_hash_show(struct seq_file *m, struct ftrace_iterator *iter) | |
8fc0c701 | 2393 | { |
b6887d79 | 2394 | struct ftrace_func_probe *rec; |
8fc0c701 | 2395 | |
4aeb6967 SR |
2396 | rec = iter->probe; |
2397 | if (WARN_ON_ONCE(!rec)) | |
2398 | return -EIO; | |
8fc0c701 | 2399 | |
809dcf29 SR |
2400 | if (rec->ops->print) |
2401 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
2402 | ||
b375a11a | 2403 | seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func); |
8fc0c701 SR |
2404 | |
2405 | if (rec->data) | |
2406 | seq_printf(m, ":%p", rec->data); | |
2407 | seq_putc(m, '\n'); | |
2408 | ||
2409 | return 0; | |
2410 | } | |
2411 | ||
e309b41d | 2412 | static void * |
5072c59f SR |
2413 | t_next(struct seq_file *m, void *v, loff_t *pos) |
2414 | { | |
2415 | struct ftrace_iterator *iter = m->private; | |
fc13cb0c | 2416 | struct ftrace_ops *ops = iter->ops; |
5072c59f SR |
2417 | struct dyn_ftrace *rec = NULL; |
2418 | ||
45a4a237 SR |
2419 | if (unlikely(ftrace_disabled)) |
2420 | return NULL; | |
2421 | ||
8fc0c701 | 2422 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 2423 | return t_hash_next(m, pos); |
8fc0c701 | 2424 | |
5072c59f | 2425 | (*pos)++; |
1106b699 | 2426 | iter->pos = iter->func_pos = *pos; |
5072c59f | 2427 | |
0c75a3ed | 2428 | if (iter->flags & FTRACE_ITER_PRINTALL) |
57c072c7 | 2429 | return t_hash_start(m, pos); |
0c75a3ed | 2430 | |
5072c59f SR |
2431 | retry: |
2432 | if (iter->idx >= iter->pg->index) { | |
2433 | if (iter->pg->next) { | |
2434 | iter->pg = iter->pg->next; | |
2435 | iter->idx = 0; | |
2436 | goto retry; | |
2437 | } | |
2438 | } else { | |
2439 | rec = &iter->pg->records[iter->idx++]; | |
32082309 | 2440 | if (((iter->flags & FTRACE_ITER_FILTER) && |
f45948e8 | 2441 | !(ftrace_lookup_ip(ops->filter_hash, rec->ip))) || |
0183fb1c | 2442 | |
41c52c0d | 2443 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
647bcd03 SR |
2444 | !ftrace_lookup_ip(ops->notrace_hash, rec->ip)) || |
2445 | ||
2446 | ((iter->flags & FTRACE_ITER_ENABLED) && | |
2447 | !(rec->flags & ~FTRACE_FL_MASK))) { | |
2448 | ||
5072c59f SR |
2449 | rec = NULL; |
2450 | goto retry; | |
2451 | } | |
2452 | } | |
2453 | ||
4aeb6967 | 2454 | if (!rec) |
57c072c7 | 2455 | return t_hash_start(m, pos); |
4aeb6967 SR |
2456 | |
2457 | iter->func = rec; | |
2458 | ||
2459 | return iter; | |
5072c59f SR |
2460 | } |
2461 | ||
98c4fd04 SR |
2462 | static void reset_iter_read(struct ftrace_iterator *iter) |
2463 | { | |
2464 | iter->pos = 0; | |
2465 | iter->func_pos = 0; | |
70f77b3f | 2466 | iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_HASH); |
5072c59f SR |
2467 | } |
2468 | ||
2469 | static void *t_start(struct seq_file *m, loff_t *pos) | |
2470 | { | |
2471 | struct ftrace_iterator *iter = m->private; | |
fc13cb0c | 2472 | struct ftrace_ops *ops = iter->ops; |
5072c59f | 2473 | void *p = NULL; |
694ce0a5 | 2474 | loff_t l; |
5072c59f | 2475 | |
8fc0c701 | 2476 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
2477 | |
2478 | if (unlikely(ftrace_disabled)) | |
2479 | return NULL; | |
2480 | ||
98c4fd04 SR |
2481 | /* |
2482 | * If an lseek was done, then reset and start from beginning. | |
2483 | */ | |
2484 | if (*pos < iter->pos) | |
2485 | reset_iter_read(iter); | |
2486 | ||
0c75a3ed SR |
2487 | /* |
2488 | * For set_ftrace_filter reading, if we have the filter | |
2489 | * off, we can short cut and just print out that all | |
2490 | * functions are enabled. | |
2491 | */ | |
06a51d93 SR |
2492 | if (iter->flags & FTRACE_ITER_FILTER && |
2493 | ftrace_hash_empty(ops->filter_hash)) { | |
0c75a3ed | 2494 | if (*pos > 0) |
8fc0c701 | 2495 | return t_hash_start(m, pos); |
0c75a3ed | 2496 | iter->flags |= FTRACE_ITER_PRINTALL; |
df091625 CW |
2497 | /* reset in case of seek/pread */ |
2498 | iter->flags &= ~FTRACE_ITER_HASH; | |
0c75a3ed SR |
2499 | return iter; |
2500 | } | |
2501 | ||
8fc0c701 SR |
2502 | if (iter->flags & FTRACE_ITER_HASH) |
2503 | return t_hash_start(m, pos); | |
2504 | ||
98c4fd04 SR |
2505 | /* |
2506 | * Unfortunately, we need to restart at ftrace_pages_start | |
2507 | * every time we let go of the ftrace_mutex. This is because | |
2508 | * those pointers can change without the lock. | |
2509 | */ | |
694ce0a5 LZ |
2510 | iter->pg = ftrace_pages_start; |
2511 | iter->idx = 0; | |
2512 | for (l = 0; l <= *pos; ) { | |
2513 | p = t_next(m, p, &l); | |
2514 | if (!p) | |
2515 | break; | |
50cdaf08 | 2516 | } |
5821e1b7 | 2517 | |
69a3083c SR |
2518 | if (!p) |
2519 | return t_hash_start(m, pos); | |
4aeb6967 SR |
2520 | |
2521 | return iter; | |
5072c59f SR |
2522 | } |
2523 | ||
2524 | static void t_stop(struct seq_file *m, void *p) | |
2525 | { | |
8fc0c701 | 2526 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
2527 | } |
2528 | ||
2529 | static int t_show(struct seq_file *m, void *v) | |
2530 | { | |
0c75a3ed | 2531 | struct ftrace_iterator *iter = m->private; |
4aeb6967 | 2532 | struct dyn_ftrace *rec; |
5072c59f | 2533 | |
8fc0c701 | 2534 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 2535 | return t_hash_show(m, iter); |
8fc0c701 | 2536 | |
0c75a3ed SR |
2537 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
2538 | seq_printf(m, "#### all functions enabled ####\n"); | |
2539 | return 0; | |
2540 | } | |
2541 | ||
4aeb6967 SR |
2542 | rec = iter->func; |
2543 | ||
5072c59f SR |
2544 | if (!rec) |
2545 | return 0; | |
2546 | ||
647bcd03 SR |
2547 | seq_printf(m, "%ps", (void *)rec->ip); |
2548 | if (iter->flags & FTRACE_ITER_ENABLED) | |
08f6fba5 SR |
2549 | seq_printf(m, " (%ld)%s", |
2550 | rec->flags & ~FTRACE_FL_MASK, | |
2551 | rec->flags & FTRACE_FL_REGS ? " R" : ""); | |
647bcd03 | 2552 | seq_printf(m, "\n"); |
5072c59f SR |
2553 | |
2554 | return 0; | |
2555 | } | |
2556 | ||
88e9d34c | 2557 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
2558 | .start = t_start, |
2559 | .next = t_next, | |
2560 | .stop = t_stop, | |
2561 | .show = t_show, | |
2562 | }; | |
2563 | ||
e309b41d | 2564 | static int |
5072c59f SR |
2565 | ftrace_avail_open(struct inode *inode, struct file *file) |
2566 | { | |
2567 | struct ftrace_iterator *iter; | |
5072c59f | 2568 | |
4eebcc81 SR |
2569 | if (unlikely(ftrace_disabled)) |
2570 | return -ENODEV; | |
2571 | ||
50e18b94 JO |
2572 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
2573 | if (iter) { | |
2574 | iter->pg = ftrace_pages_start; | |
2575 | iter->ops = &global_ops; | |
4bf39a94 | 2576 | } |
5072c59f | 2577 | |
50e18b94 | 2578 | return iter ? 0 : -ENOMEM; |
5072c59f SR |
2579 | } |
2580 | ||
647bcd03 SR |
2581 | static int |
2582 | ftrace_enabled_open(struct inode *inode, struct file *file) | |
2583 | { | |
2584 | struct ftrace_iterator *iter; | |
647bcd03 SR |
2585 | |
2586 | if (unlikely(ftrace_disabled)) | |
2587 | return -ENODEV; | |
2588 | ||
50e18b94 JO |
2589 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
2590 | if (iter) { | |
2591 | iter->pg = ftrace_pages_start; | |
2592 | iter->flags = FTRACE_ITER_ENABLED; | |
2593 | iter->ops = &global_ops; | |
647bcd03 SR |
2594 | } |
2595 | ||
50e18b94 | 2596 | return iter ? 0 : -ENOMEM; |
647bcd03 SR |
2597 | } |
2598 | ||
1cf41dd7 | 2599 | static void ftrace_filter_reset(struct ftrace_hash *hash) |
5072c59f | 2600 | { |
52baf119 | 2601 | mutex_lock(&ftrace_lock); |
1cf41dd7 | 2602 | ftrace_hash_clear(hash); |
52baf119 | 2603 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
2604 | } |
2605 | ||
fc13cb0c SR |
2606 | /** |
2607 | * ftrace_regex_open - initialize function tracer filter files | |
2608 | * @ops: The ftrace_ops that hold the hash filters | |
2609 | * @flag: The type of filter to process | |
2610 | * @inode: The inode, usually passed in to your open routine | |
2611 | * @file: The file, usually passed in to your open routine | |
2612 | * | |
2613 | * ftrace_regex_open() initializes the filter files for the | |
2614 | * @ops. Depending on @flag it may process the filter hash or | |
2615 | * the notrace hash of @ops. With this called from the open | |
2616 | * routine, you can use ftrace_filter_write() for the write | |
2617 | * routine if @flag has FTRACE_ITER_FILTER set, or | |
2618 | * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set. | |
2619 | * ftrace_regex_lseek() should be used as the lseek routine, and | |
2620 | * release must call ftrace_regex_release(). | |
2621 | */ | |
2622 | int | |
f45948e8 | 2623 | ftrace_regex_open(struct ftrace_ops *ops, int flag, |
1cf41dd7 | 2624 | struct inode *inode, struct file *file) |
5072c59f SR |
2625 | { |
2626 | struct ftrace_iterator *iter; | |
f45948e8 | 2627 | struct ftrace_hash *hash; |
5072c59f SR |
2628 | int ret = 0; |
2629 | ||
4eebcc81 SR |
2630 | if (unlikely(ftrace_disabled)) |
2631 | return -ENODEV; | |
2632 | ||
5072c59f SR |
2633 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
2634 | if (!iter) | |
2635 | return -ENOMEM; | |
2636 | ||
689fd8b6 | 2637 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) { |
2638 | kfree(iter); | |
2639 | return -ENOMEM; | |
2640 | } | |
2641 | ||
f45948e8 SR |
2642 | if (flag & FTRACE_ITER_NOTRACE) |
2643 | hash = ops->notrace_hash; | |
2644 | else | |
2645 | hash = ops->filter_hash; | |
2646 | ||
33dc9b12 SR |
2647 | iter->ops = ops; |
2648 | iter->flags = flag; | |
2649 | ||
2650 | if (file->f_mode & FMODE_WRITE) { | |
2651 | mutex_lock(&ftrace_lock); | |
2652 | iter->hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash); | |
2653 | mutex_unlock(&ftrace_lock); | |
2654 | ||
2655 | if (!iter->hash) { | |
2656 | trace_parser_put(&iter->parser); | |
2657 | kfree(iter); | |
2658 | return -ENOMEM; | |
2659 | } | |
2660 | } | |
1cf41dd7 | 2661 | |
41c52c0d | 2662 | mutex_lock(&ftrace_regex_lock); |
33dc9b12 | 2663 | |
5072c59f | 2664 | if ((file->f_mode & FMODE_WRITE) && |
8650ae32 | 2665 | (file->f_flags & O_TRUNC)) |
33dc9b12 | 2666 | ftrace_filter_reset(iter->hash); |
5072c59f SR |
2667 | |
2668 | if (file->f_mode & FMODE_READ) { | |
2669 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
2670 | |
2671 | ret = seq_open(file, &show_ftrace_seq_ops); | |
2672 | if (!ret) { | |
2673 | struct seq_file *m = file->private_data; | |
2674 | m->private = iter; | |
79fe249c | 2675 | } else { |
33dc9b12 SR |
2676 | /* Failed */ |
2677 | free_ftrace_hash(iter->hash); | |
79fe249c | 2678 | trace_parser_put(&iter->parser); |
5072c59f | 2679 | kfree(iter); |
79fe249c | 2680 | } |
5072c59f SR |
2681 | } else |
2682 | file->private_data = iter; | |
41c52c0d | 2683 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
2684 | |
2685 | return ret; | |
2686 | } | |
2687 | ||
41c52c0d SR |
2688 | static int |
2689 | ftrace_filter_open(struct inode *inode, struct file *file) | |
2690 | { | |
69a3083c SR |
2691 | return ftrace_regex_open(&global_ops, |
2692 | FTRACE_ITER_FILTER | FTRACE_ITER_DO_HASH, | |
2693 | inode, file); | |
41c52c0d SR |
2694 | } |
2695 | ||
2696 | static int | |
2697 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
2698 | { | |
f45948e8 | 2699 | return ftrace_regex_open(&global_ops, FTRACE_ITER_NOTRACE, |
1cf41dd7 | 2700 | inode, file); |
41c52c0d SR |
2701 | } |
2702 | ||
fc13cb0c | 2703 | loff_t |
965c8e59 | 2704 | ftrace_regex_lseek(struct file *file, loff_t offset, int whence) |
5072c59f SR |
2705 | { |
2706 | loff_t ret; | |
2707 | ||
2708 | if (file->f_mode & FMODE_READ) | |
965c8e59 | 2709 | ret = seq_lseek(file, offset, whence); |
5072c59f SR |
2710 | else |
2711 | file->f_pos = ret = 1; | |
2712 | ||
2713 | return ret; | |
2714 | } | |
2715 | ||
64e7c440 | 2716 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 2717 | { |
9f4801e3 | 2718 | int matched = 0; |
751e9983 | 2719 | int slen; |
9f4801e3 | 2720 | |
9f4801e3 SR |
2721 | switch (type) { |
2722 | case MATCH_FULL: | |
2723 | if (strcmp(str, regex) == 0) | |
2724 | matched = 1; | |
2725 | break; | |
2726 | case MATCH_FRONT_ONLY: | |
2727 | if (strncmp(str, regex, len) == 0) | |
2728 | matched = 1; | |
2729 | break; | |
2730 | case MATCH_MIDDLE_ONLY: | |
2731 | if (strstr(str, regex)) | |
2732 | matched = 1; | |
2733 | break; | |
2734 | case MATCH_END_ONLY: | |
751e9983 LZ |
2735 | slen = strlen(str); |
2736 | if (slen >= len && memcmp(str + slen - len, regex, len) == 0) | |
9f4801e3 SR |
2737 | matched = 1; |
2738 | break; | |
2739 | } | |
2740 | ||
2741 | return matched; | |
2742 | } | |
2743 | ||
b448c4e3 | 2744 | static int |
1cf41dd7 | 2745 | enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not) |
996e87be | 2746 | { |
b448c4e3 | 2747 | struct ftrace_func_entry *entry; |
b448c4e3 SR |
2748 | int ret = 0; |
2749 | ||
1cf41dd7 SR |
2750 | entry = ftrace_lookup_ip(hash, rec->ip); |
2751 | if (not) { | |
2752 | /* Do nothing if it doesn't exist */ | |
2753 | if (!entry) | |
2754 | return 0; | |
b448c4e3 | 2755 | |
33dc9b12 | 2756 | free_hash_entry(hash, entry); |
1cf41dd7 SR |
2757 | } else { |
2758 | /* Do nothing if it exists */ | |
2759 | if (entry) | |
2760 | return 0; | |
b448c4e3 | 2761 | |
1cf41dd7 | 2762 | ret = add_hash_entry(hash, rec->ip); |
b448c4e3 SR |
2763 | } |
2764 | return ret; | |
996e87be SR |
2765 | } |
2766 | ||
64e7c440 | 2767 | static int |
b9df92d2 SR |
2768 | ftrace_match_record(struct dyn_ftrace *rec, char *mod, |
2769 | char *regex, int len, int type) | |
64e7c440 SR |
2770 | { |
2771 | char str[KSYM_SYMBOL_LEN]; | |
b9df92d2 SR |
2772 | char *modname; |
2773 | ||
2774 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
2775 | ||
2776 | if (mod) { | |
2777 | /* module lookup requires matching the module */ | |
2778 | if (!modname || strcmp(modname, mod)) | |
2779 | return 0; | |
2780 | ||
2781 | /* blank search means to match all funcs in the mod */ | |
2782 | if (!len) | |
2783 | return 1; | |
2784 | } | |
64e7c440 | 2785 | |
64e7c440 SR |
2786 | return ftrace_match(str, regex, len, type); |
2787 | } | |
2788 | ||
1cf41dd7 SR |
2789 | static int |
2790 | match_records(struct ftrace_hash *hash, char *buff, | |
2791 | int len, char *mod, int not) | |
9f4801e3 | 2792 | { |
b9df92d2 | 2793 | unsigned search_len = 0; |
9f4801e3 SR |
2794 | struct ftrace_page *pg; |
2795 | struct dyn_ftrace *rec; | |
b9df92d2 SR |
2796 | int type = MATCH_FULL; |
2797 | char *search = buff; | |
311d16da | 2798 | int found = 0; |
b448c4e3 | 2799 | int ret; |
9f4801e3 | 2800 | |
b9df92d2 SR |
2801 | if (len) { |
2802 | type = filter_parse_regex(buff, len, &search, ¬); | |
2803 | search_len = strlen(search); | |
2804 | } | |
9f4801e3 | 2805 | |
52baf119 | 2806 | mutex_lock(&ftrace_lock); |
265c831c | 2807 | |
b9df92d2 SR |
2808 | if (unlikely(ftrace_disabled)) |
2809 | goto out_unlock; | |
9f4801e3 | 2810 | |
265c831c | 2811 | do_for_each_ftrace_rec(pg, rec) { |
b9df92d2 | 2812 | if (ftrace_match_record(rec, mod, search, search_len, type)) { |
1cf41dd7 | 2813 | ret = enter_record(hash, rec, not); |
b448c4e3 SR |
2814 | if (ret < 0) { |
2815 | found = ret; | |
2816 | goto out_unlock; | |
2817 | } | |
311d16da | 2818 | found = 1; |
265c831c SR |
2819 | } |
2820 | } while_for_each_ftrace_rec(); | |
b9df92d2 | 2821 | out_unlock: |
52baf119 | 2822 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
2823 | |
2824 | return found; | |
5072c59f SR |
2825 | } |
2826 | ||
64e7c440 | 2827 | static int |
1cf41dd7 | 2828 | ftrace_match_records(struct ftrace_hash *hash, char *buff, int len) |
64e7c440 | 2829 | { |
1cf41dd7 | 2830 | return match_records(hash, buff, len, NULL, 0); |
64e7c440 SR |
2831 | } |
2832 | ||
1cf41dd7 SR |
2833 | static int |
2834 | ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod) | |
64e7c440 | 2835 | { |
64e7c440 | 2836 | int not = 0; |
6a24a244 | 2837 | |
64e7c440 SR |
2838 | /* blank or '*' mean the same */ |
2839 | if (strcmp(buff, "*") == 0) | |
2840 | buff[0] = 0; | |
2841 | ||
2842 | /* handle the case of 'dont filter this module' */ | |
2843 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
2844 | buff[0] = 0; | |
2845 | not = 1; | |
2846 | } | |
2847 | ||
1cf41dd7 | 2848 | return match_records(hash, buff, strlen(buff), mod, not); |
64e7c440 SR |
2849 | } |
2850 | ||
f6180773 SR |
2851 | /* |
2852 | * We register the module command as a template to show others how | |
2853 | * to register the a command as well. | |
2854 | */ | |
2855 | ||
2856 | static int | |
43dd61c9 SR |
2857 | ftrace_mod_callback(struct ftrace_hash *hash, |
2858 | char *func, char *cmd, char *param, int enable) | |
f6180773 SR |
2859 | { |
2860 | char *mod; | |
b448c4e3 | 2861 | int ret = -EINVAL; |
f6180773 SR |
2862 | |
2863 | /* | |
2864 | * cmd == 'mod' because we only registered this func | |
2865 | * for the 'mod' ftrace_func_command. | |
2866 | * But if you register one func with multiple commands, | |
2867 | * you can tell which command was used by the cmd | |
2868 | * parameter. | |
2869 | */ | |
2870 | ||
2871 | /* we must have a module name */ | |
2872 | if (!param) | |
b448c4e3 | 2873 | return ret; |
f6180773 SR |
2874 | |
2875 | mod = strsep(¶m, ":"); | |
2876 | if (!strlen(mod)) | |
b448c4e3 | 2877 | return ret; |
f6180773 | 2878 | |
1cf41dd7 | 2879 | ret = ftrace_match_module_records(hash, func, mod); |
b448c4e3 SR |
2880 | if (!ret) |
2881 | ret = -EINVAL; | |
2882 | if (ret < 0) | |
2883 | return ret; | |
2884 | ||
2885 | return 0; | |
f6180773 SR |
2886 | } |
2887 | ||
2888 | static struct ftrace_func_command ftrace_mod_cmd = { | |
2889 | .name = "mod", | |
2890 | .func = ftrace_mod_callback, | |
2891 | }; | |
2892 | ||
2893 | static int __init ftrace_mod_cmd_init(void) | |
2894 | { | |
2895 | return register_ftrace_command(&ftrace_mod_cmd); | |
2896 | } | |
6f415672 | 2897 | core_initcall(ftrace_mod_cmd_init); |
f6180773 | 2898 | |
2f5f6ad9 | 2899 | static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 2900 | struct ftrace_ops *op, struct pt_regs *pt_regs) |
59df055f | 2901 | { |
b6887d79 | 2902 | struct ftrace_func_probe *entry; |
59df055f SR |
2903 | struct hlist_head *hhd; |
2904 | struct hlist_node *n; | |
2905 | unsigned long key; | |
59df055f SR |
2906 | |
2907 | key = hash_long(ip, FTRACE_HASH_BITS); | |
2908 | ||
2909 | hhd = &ftrace_func_hash[key]; | |
2910 | ||
2911 | if (hlist_empty(hhd)) | |
2912 | return; | |
2913 | ||
2914 | /* | |
2915 | * Disable preemption for these calls to prevent a RCU grace | |
2916 | * period. This syncs the hash iteration and freeing of items | |
2917 | * on the hash. rcu_read_lock is too dangerous here. | |
2918 | */ | |
5168ae50 | 2919 | preempt_disable_notrace(); |
59df055f SR |
2920 | hlist_for_each_entry_rcu(entry, n, hhd, node) { |
2921 | if (entry->ip == ip) | |
2922 | entry->ops->func(ip, parent_ip, &entry->data); | |
2923 | } | |
5168ae50 | 2924 | preempt_enable_notrace(); |
59df055f SR |
2925 | } |
2926 | ||
b6887d79 | 2927 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 2928 | { |
fb9fb015 | 2929 | .func = function_trace_probe_call, |
59df055f SR |
2930 | }; |
2931 | ||
b6887d79 | 2932 | static int ftrace_probe_registered; |
59df055f | 2933 | |
b6887d79 | 2934 | static void __enable_ftrace_function_probe(void) |
59df055f | 2935 | { |
b848914c | 2936 | int ret; |
59df055f SR |
2937 | int i; |
2938 | ||
b6887d79 | 2939 | if (ftrace_probe_registered) |
59df055f SR |
2940 | return; |
2941 | ||
2942 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2943 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2944 | if (hhd->first) | |
2945 | break; | |
2946 | } | |
2947 | /* Nothing registered? */ | |
2948 | if (i == FTRACE_FUNC_HASHSIZE) | |
2949 | return; | |
2950 | ||
b848914c SR |
2951 | ret = __register_ftrace_function(&trace_probe_ops); |
2952 | if (!ret) | |
a1cd6173 | 2953 | ret = ftrace_startup(&trace_probe_ops, 0); |
b848914c | 2954 | |
b6887d79 | 2955 | ftrace_probe_registered = 1; |
59df055f SR |
2956 | } |
2957 | ||
b6887d79 | 2958 | static void __disable_ftrace_function_probe(void) |
59df055f | 2959 | { |
b848914c | 2960 | int ret; |
59df055f SR |
2961 | int i; |
2962 | ||
b6887d79 | 2963 | if (!ftrace_probe_registered) |
59df055f SR |
2964 | return; |
2965 | ||
2966 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2967 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2968 | if (hhd->first) | |
2969 | return; | |
2970 | } | |
2971 | ||
2972 | /* no more funcs left */ | |
b848914c SR |
2973 | ret = __unregister_ftrace_function(&trace_probe_ops); |
2974 | if (!ret) | |
2975 | ftrace_shutdown(&trace_probe_ops, 0); | |
2976 | ||
b6887d79 | 2977 | ftrace_probe_registered = 0; |
59df055f SR |
2978 | } |
2979 | ||
2980 | ||
2981 | static void ftrace_free_entry_rcu(struct rcu_head *rhp) | |
2982 | { | |
b6887d79 SR |
2983 | struct ftrace_func_probe *entry = |
2984 | container_of(rhp, struct ftrace_func_probe, rcu); | |
59df055f SR |
2985 | |
2986 | if (entry->ops->free) | |
2987 | entry->ops->free(&entry->data); | |
2988 | kfree(entry); | |
2989 | } | |
2990 | ||
2991 | ||
2992 | int | |
b6887d79 | 2993 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
2994 | void *data) |
2995 | { | |
b6887d79 | 2996 | struct ftrace_func_probe *entry; |
59df055f SR |
2997 | struct ftrace_page *pg; |
2998 | struct dyn_ftrace *rec; | |
59df055f | 2999 | int type, len, not; |
6a24a244 | 3000 | unsigned long key; |
59df055f SR |
3001 | int count = 0; |
3002 | char *search; | |
3003 | ||
3f6fe06d | 3004 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
3005 | len = strlen(search); |
3006 | ||
b6887d79 | 3007 | /* we do not support '!' for function probes */ |
59df055f SR |
3008 | if (WARN_ON(not)) |
3009 | return -EINVAL; | |
3010 | ||
3011 | mutex_lock(&ftrace_lock); | |
59df055f | 3012 | |
45a4a237 SR |
3013 | if (unlikely(ftrace_disabled)) |
3014 | goto out_unlock; | |
59df055f | 3015 | |
45a4a237 | 3016 | do_for_each_ftrace_rec(pg, rec) { |
59df055f | 3017 | |
b9df92d2 | 3018 | if (!ftrace_match_record(rec, NULL, search, len, type)) |
59df055f SR |
3019 | continue; |
3020 | ||
3021 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
3022 | if (!entry) { | |
b6887d79 | 3023 | /* If we did not process any, then return error */ |
59df055f SR |
3024 | if (!count) |
3025 | count = -ENOMEM; | |
3026 | goto out_unlock; | |
3027 | } | |
3028 | ||
3029 | count++; | |
3030 | ||
3031 | entry->data = data; | |
3032 | ||
3033 | /* | |
3034 | * The caller might want to do something special | |
3035 | * for each function we find. We call the callback | |
3036 | * to give the caller an opportunity to do so. | |
3037 | */ | |
3038 | if (ops->callback) { | |
3039 | if (ops->callback(rec->ip, &entry->data) < 0) { | |
3040 | /* caller does not like this func */ | |
3041 | kfree(entry); | |
3042 | continue; | |
3043 | } | |
3044 | } | |
3045 | ||
3046 | entry->ops = ops; | |
3047 | entry->ip = rec->ip; | |
3048 | ||
3049 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
3050 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
3051 | ||
3052 | } while_for_each_ftrace_rec(); | |
b6887d79 | 3053 | __enable_ftrace_function_probe(); |
59df055f SR |
3054 | |
3055 | out_unlock: | |
3056 | mutex_unlock(&ftrace_lock); | |
3057 | ||
3058 | return count; | |
3059 | } | |
3060 | ||
3061 | enum { | |
b6887d79 SR |
3062 | PROBE_TEST_FUNC = 1, |
3063 | PROBE_TEST_DATA = 2 | |
59df055f SR |
3064 | }; |
3065 | ||
3066 | static void | |
b6887d79 | 3067 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3068 | void *data, int flags) |
3069 | { | |
b6887d79 | 3070 | struct ftrace_func_probe *entry; |
59df055f SR |
3071 | struct hlist_node *n, *tmp; |
3072 | char str[KSYM_SYMBOL_LEN]; | |
3073 | int type = MATCH_FULL; | |
3074 | int i, len = 0; | |
3075 | char *search; | |
3076 | ||
b36461da | 3077 | if (glob && (strcmp(glob, "*") == 0 || !strlen(glob))) |
59df055f | 3078 | glob = NULL; |
b36461da | 3079 | else if (glob) { |
59df055f SR |
3080 | int not; |
3081 | ||
3f6fe06d | 3082 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
3083 | len = strlen(search); |
3084 | ||
b6887d79 | 3085 | /* we do not support '!' for function probes */ |
59df055f SR |
3086 | if (WARN_ON(not)) |
3087 | return; | |
3088 | } | |
3089 | ||
3090 | mutex_lock(&ftrace_lock); | |
3091 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
3092 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
3093 | ||
3094 | hlist_for_each_entry_safe(entry, n, tmp, hhd, node) { | |
3095 | ||
3096 | /* break up if statements for readability */ | |
b6887d79 | 3097 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
3098 | continue; |
3099 | ||
b6887d79 | 3100 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
3101 | continue; |
3102 | ||
3103 | /* do this last, since it is the most expensive */ | |
3104 | if (glob) { | |
3105 | kallsyms_lookup(entry->ip, NULL, NULL, | |
3106 | NULL, str); | |
3107 | if (!ftrace_match(str, glob, len, type)) | |
3108 | continue; | |
3109 | } | |
3110 | ||
3111 | hlist_del(&entry->node); | |
3112 | call_rcu(&entry->rcu, ftrace_free_entry_rcu); | |
3113 | } | |
3114 | } | |
b6887d79 | 3115 | __disable_ftrace_function_probe(); |
59df055f SR |
3116 | mutex_unlock(&ftrace_lock); |
3117 | } | |
3118 | ||
3119 | void | |
b6887d79 | 3120 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3121 | void *data) |
3122 | { | |
b6887d79 SR |
3123 | __unregister_ftrace_function_probe(glob, ops, data, |
3124 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
3125 | } |
3126 | ||
3127 | void | |
b6887d79 | 3128 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 3129 | { |
b6887d79 | 3130 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
3131 | } |
3132 | ||
b6887d79 | 3133 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 3134 | { |
b6887d79 | 3135 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
3136 | } |
3137 | ||
f6180773 SR |
3138 | static LIST_HEAD(ftrace_commands); |
3139 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
3140 | ||
3141 | int register_ftrace_command(struct ftrace_func_command *cmd) | |
3142 | { | |
3143 | struct ftrace_func_command *p; | |
3144 | int ret = 0; | |
3145 | ||
3146 | mutex_lock(&ftrace_cmd_mutex); | |
3147 | list_for_each_entry(p, &ftrace_commands, list) { | |
3148 | if (strcmp(cmd->name, p->name) == 0) { | |
3149 | ret = -EBUSY; | |
3150 | goto out_unlock; | |
3151 | } | |
3152 | } | |
3153 | list_add(&cmd->list, &ftrace_commands); | |
3154 | out_unlock: | |
3155 | mutex_unlock(&ftrace_cmd_mutex); | |
3156 | ||
3157 | return ret; | |
3158 | } | |
3159 | ||
3160 | int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
3161 | { | |
3162 | struct ftrace_func_command *p, *n; | |
3163 | int ret = -ENODEV; | |
3164 | ||
3165 | mutex_lock(&ftrace_cmd_mutex); | |
3166 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
3167 | if (strcmp(cmd->name, p->name) == 0) { | |
3168 | ret = 0; | |
3169 | list_del_init(&p->list); | |
3170 | goto out_unlock; | |
3171 | } | |
3172 | } | |
3173 | out_unlock: | |
3174 | mutex_unlock(&ftrace_cmd_mutex); | |
3175 | ||
3176 | return ret; | |
3177 | } | |
3178 | ||
33dc9b12 SR |
3179 | static int ftrace_process_regex(struct ftrace_hash *hash, |
3180 | char *buff, int len, int enable) | |
64e7c440 | 3181 | { |
f6180773 | 3182 | char *func, *command, *next = buff; |
6a24a244 | 3183 | struct ftrace_func_command *p; |
0aff1c0c | 3184 | int ret = -EINVAL; |
64e7c440 SR |
3185 | |
3186 | func = strsep(&next, ":"); | |
3187 | ||
3188 | if (!next) { | |
1cf41dd7 | 3189 | ret = ftrace_match_records(hash, func, len); |
b448c4e3 SR |
3190 | if (!ret) |
3191 | ret = -EINVAL; | |
3192 | if (ret < 0) | |
3193 | return ret; | |
3194 | return 0; | |
64e7c440 SR |
3195 | } |
3196 | ||
f6180773 | 3197 | /* command found */ |
64e7c440 SR |
3198 | |
3199 | command = strsep(&next, ":"); | |
3200 | ||
f6180773 SR |
3201 | mutex_lock(&ftrace_cmd_mutex); |
3202 | list_for_each_entry(p, &ftrace_commands, list) { | |
3203 | if (strcmp(p->name, command) == 0) { | |
43dd61c9 | 3204 | ret = p->func(hash, func, command, next, enable); |
f6180773 SR |
3205 | goto out_unlock; |
3206 | } | |
64e7c440 | 3207 | } |
f6180773 SR |
3208 | out_unlock: |
3209 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 3210 | |
f6180773 | 3211 | return ret; |
64e7c440 SR |
3212 | } |
3213 | ||
e309b41d | 3214 | static ssize_t |
41c52c0d SR |
3215 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
3216 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
3217 | { |
3218 | struct ftrace_iterator *iter; | |
689fd8b6 | 3219 | struct trace_parser *parser; |
3220 | ssize_t ret, read; | |
5072c59f | 3221 | |
4ba7978e | 3222 | if (!cnt) |
5072c59f SR |
3223 | return 0; |
3224 | ||
41c52c0d | 3225 | mutex_lock(&ftrace_regex_lock); |
5072c59f | 3226 | |
45a4a237 SR |
3227 | ret = -ENODEV; |
3228 | if (unlikely(ftrace_disabled)) | |
3229 | goto out_unlock; | |
3230 | ||
5072c59f SR |
3231 | if (file->f_mode & FMODE_READ) { |
3232 | struct seq_file *m = file->private_data; | |
3233 | iter = m->private; | |
3234 | } else | |
3235 | iter = file->private_data; | |
3236 | ||
689fd8b6 | 3237 | parser = &iter->parser; |
3238 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 3239 | |
4ba7978e | 3240 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 3241 | !trace_parser_cont(parser)) { |
33dc9b12 | 3242 | ret = ftrace_process_regex(iter->hash, parser->buffer, |
689fd8b6 | 3243 | parser->idx, enable); |
313254a9 | 3244 | trace_parser_clear(parser); |
5072c59f | 3245 | if (ret) |
ed146b25 | 3246 | goto out_unlock; |
eda1e328 | 3247 | } |
5072c59f | 3248 | |
5072c59f | 3249 | ret = read; |
ed146b25 | 3250 | out_unlock: |
689fd8b6 | 3251 | mutex_unlock(&ftrace_regex_lock); |
ed146b25 | 3252 | |
5072c59f SR |
3253 | return ret; |
3254 | } | |
3255 | ||
fc13cb0c | 3256 | ssize_t |
41c52c0d SR |
3257 | ftrace_filter_write(struct file *file, const char __user *ubuf, |
3258 | size_t cnt, loff_t *ppos) | |
3259 | { | |
3260 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
3261 | } | |
3262 | ||
fc13cb0c | 3263 | ssize_t |
41c52c0d SR |
3264 | ftrace_notrace_write(struct file *file, const char __user *ubuf, |
3265 | size_t cnt, loff_t *ppos) | |
3266 | { | |
3267 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
3268 | } | |
3269 | ||
33dc9b12 | 3270 | static int |
647664ea MH |
3271 | ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) |
3272 | { | |
3273 | struct ftrace_func_entry *entry; | |
3274 | ||
3275 | if (!ftrace_location(ip)) | |
3276 | return -EINVAL; | |
3277 | ||
3278 | if (remove) { | |
3279 | entry = ftrace_lookup_ip(hash, ip); | |
3280 | if (!entry) | |
3281 | return -ENOENT; | |
3282 | free_hash_entry(hash, entry); | |
3283 | return 0; | |
3284 | } | |
3285 | ||
3286 | return add_hash_entry(hash, ip); | |
3287 | } | |
3288 | ||
3289 | static int | |
3290 | ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, | |
3291 | unsigned long ip, int remove, int reset, int enable) | |
41c52c0d | 3292 | { |
33dc9b12 | 3293 | struct ftrace_hash **orig_hash; |
f45948e8 | 3294 | struct ftrace_hash *hash; |
33dc9b12 | 3295 | int ret; |
f45948e8 | 3296 | |
936e074b SR |
3297 | /* All global ops uses the global ops filters */ |
3298 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) | |
3299 | ops = &global_ops; | |
3300 | ||
41c52c0d | 3301 | if (unlikely(ftrace_disabled)) |
33dc9b12 | 3302 | return -ENODEV; |
41c52c0d | 3303 | |
f45948e8 | 3304 | if (enable) |
33dc9b12 | 3305 | orig_hash = &ops->filter_hash; |
f45948e8 | 3306 | else |
33dc9b12 SR |
3307 | orig_hash = &ops->notrace_hash; |
3308 | ||
3309 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
3310 | if (!hash) | |
3311 | return -ENOMEM; | |
f45948e8 | 3312 | |
41c52c0d SR |
3313 | mutex_lock(&ftrace_regex_lock); |
3314 | if (reset) | |
1cf41dd7 | 3315 | ftrace_filter_reset(hash); |
ac483c44 JO |
3316 | if (buf && !ftrace_match_records(hash, buf, len)) { |
3317 | ret = -EINVAL; | |
3318 | goto out_regex_unlock; | |
3319 | } | |
647664ea MH |
3320 | if (ip) { |
3321 | ret = ftrace_match_addr(hash, ip, remove); | |
3322 | if (ret < 0) | |
3323 | goto out_regex_unlock; | |
3324 | } | |
33dc9b12 SR |
3325 | |
3326 | mutex_lock(&ftrace_lock); | |
41fb61c2 | 3327 | ret = ftrace_hash_move(ops, enable, orig_hash, hash); |
072126f4 SR |
3328 | if (!ret && ops->flags & FTRACE_OPS_FL_ENABLED |
3329 | && ftrace_enabled) | |
30fb6aa7 | 3330 | ftrace_run_update_code(FTRACE_UPDATE_CALLS); |
072126f4 | 3331 | |
33dc9b12 SR |
3332 | mutex_unlock(&ftrace_lock); |
3333 | ||
ac483c44 | 3334 | out_regex_unlock: |
41c52c0d | 3335 | mutex_unlock(&ftrace_regex_lock); |
33dc9b12 SR |
3336 | |
3337 | free_ftrace_hash(hash); | |
3338 | return ret; | |
41c52c0d SR |
3339 | } |
3340 | ||
647664ea MH |
3341 | static int |
3342 | ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove, | |
3343 | int reset, int enable) | |
3344 | { | |
3345 | return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable); | |
3346 | } | |
3347 | ||
3348 | /** | |
3349 | * ftrace_set_filter_ip - set a function to filter on in ftrace by address | |
3350 | * @ops - the ops to set the filter with | |
3351 | * @ip - the address to add to or remove from the filter. | |
3352 | * @remove - non zero to remove the ip from the filter | |
3353 | * @reset - non zero to reset all filters before applying this filter. | |
3354 | * | |
3355 | * Filters denote which functions should be enabled when tracing is enabled | |
3356 | * If @ip is NULL, it failes to update filter. | |
3357 | */ | |
3358 | int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, | |
3359 | int remove, int reset) | |
3360 | { | |
3361 | return ftrace_set_addr(ops, ip, remove, reset, 1); | |
3362 | } | |
3363 | EXPORT_SYMBOL_GPL(ftrace_set_filter_ip); | |
3364 | ||
3365 | static int | |
3366 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, | |
3367 | int reset, int enable) | |
3368 | { | |
3369 | return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable); | |
3370 | } | |
3371 | ||
77a2b37d SR |
3372 | /** |
3373 | * ftrace_set_filter - set a function to filter on in ftrace | |
936e074b SR |
3374 | * @ops - the ops to set the filter with |
3375 | * @buf - the string that holds the function filter text. | |
3376 | * @len - the length of the string. | |
3377 | * @reset - non zero to reset all filters before applying this filter. | |
3378 | * | |
3379 | * Filters denote which functions should be enabled when tracing is enabled. | |
3380 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
3381 | */ | |
ac483c44 | 3382 | int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
3383 | int len, int reset) |
3384 | { | |
ac483c44 | 3385 | return ftrace_set_regex(ops, buf, len, reset, 1); |
936e074b SR |
3386 | } |
3387 | EXPORT_SYMBOL_GPL(ftrace_set_filter); | |
3388 | ||
3389 | /** | |
3390 | * ftrace_set_notrace - set a function to not trace in ftrace | |
3391 | * @ops - the ops to set the notrace filter with | |
3392 | * @buf - the string that holds the function notrace text. | |
3393 | * @len - the length of the string. | |
3394 | * @reset - non zero to reset all filters before applying this filter. | |
3395 | * | |
3396 | * Notrace Filters denote which functions should not be enabled when tracing | |
3397 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
3398 | * for tracing. | |
3399 | */ | |
ac483c44 | 3400 | int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
3401 | int len, int reset) |
3402 | { | |
ac483c44 | 3403 | return ftrace_set_regex(ops, buf, len, reset, 0); |
936e074b SR |
3404 | } |
3405 | EXPORT_SYMBOL_GPL(ftrace_set_notrace); | |
3406 | /** | |
3407 | * ftrace_set_filter - set a function to filter on in ftrace | |
3408 | * @ops - the ops to set the filter with | |
77a2b37d SR |
3409 | * @buf - the string that holds the function filter text. |
3410 | * @len - the length of the string. | |
3411 | * @reset - non zero to reset all filters before applying this filter. | |
3412 | * | |
3413 | * Filters denote which functions should be enabled when tracing is enabled. | |
3414 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
3415 | */ | |
936e074b | 3416 | void ftrace_set_global_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 3417 | { |
f45948e8 | 3418 | ftrace_set_regex(&global_ops, buf, len, reset, 1); |
41c52c0d | 3419 | } |
936e074b | 3420 | EXPORT_SYMBOL_GPL(ftrace_set_global_filter); |
4eebcc81 | 3421 | |
41c52c0d SR |
3422 | /** |
3423 | * ftrace_set_notrace - set a function to not trace in ftrace | |
936e074b | 3424 | * @ops - the ops to set the notrace filter with |
41c52c0d SR |
3425 | * @buf - the string that holds the function notrace text. |
3426 | * @len - the length of the string. | |
3427 | * @reset - non zero to reset all filters before applying this filter. | |
3428 | * | |
3429 | * Notrace Filters denote which functions should not be enabled when tracing | |
3430 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
3431 | * for tracing. | |
3432 | */ | |
936e074b | 3433 | void ftrace_set_global_notrace(unsigned char *buf, int len, int reset) |
41c52c0d | 3434 | { |
f45948e8 | 3435 | ftrace_set_regex(&global_ops, buf, len, reset, 0); |
77a2b37d | 3436 | } |
936e074b | 3437 | EXPORT_SYMBOL_GPL(ftrace_set_global_notrace); |
77a2b37d | 3438 | |
2af15d6a SR |
3439 | /* |
3440 | * command line interface to allow users to set filters on boot up. | |
3441 | */ | |
3442 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
3443 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
3444 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
3445 | ||
3446 | static int __init set_ftrace_notrace(char *str) | |
3447 | { | |
3448 | strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); | |
3449 | return 1; | |
3450 | } | |
3451 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
3452 | ||
3453 | static int __init set_ftrace_filter(char *str) | |
3454 | { | |
3455 | strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); | |
3456 | return 1; | |
3457 | } | |
3458 | __setup("ftrace_filter=", set_ftrace_filter); | |
3459 | ||
369bc18f | 3460 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 3461 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
801c29fd SR |
3462 | static int ftrace_set_func(unsigned long *array, int *idx, char *buffer); |
3463 | ||
369bc18f SA |
3464 | static int __init set_graph_function(char *str) |
3465 | { | |
06f43d66 | 3466 | strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
3467 | return 1; |
3468 | } | |
3469 | __setup("ftrace_graph_filter=", set_graph_function); | |
3470 | ||
3471 | static void __init set_ftrace_early_graph(char *buf) | |
3472 | { | |
3473 | int ret; | |
3474 | char *func; | |
3475 | ||
3476 | while (buf) { | |
3477 | func = strsep(&buf, ","); | |
3478 | /* we allow only one expression at a time */ | |
3479 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, | |
3480 | func); | |
3481 | if (ret) | |
3482 | printk(KERN_DEBUG "ftrace: function %s not " | |
3483 | "traceable\n", func); | |
3484 | } | |
3485 | } | |
3486 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
3487 | ||
2a85a37f SR |
3488 | void __init |
3489 | ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable) | |
2af15d6a SR |
3490 | { |
3491 | char *func; | |
3492 | ||
3493 | while (buf) { | |
3494 | func = strsep(&buf, ","); | |
f45948e8 | 3495 | ftrace_set_regex(ops, func, strlen(func), 0, enable); |
2af15d6a SR |
3496 | } |
3497 | } | |
3498 | ||
3499 | static void __init set_ftrace_early_filters(void) | |
3500 | { | |
3501 | if (ftrace_filter_buf[0]) | |
2a85a37f | 3502 | ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1); |
2af15d6a | 3503 | if (ftrace_notrace_buf[0]) |
2a85a37f | 3504 | ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0); |
369bc18f SA |
3505 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
3506 | if (ftrace_graph_buf[0]) | |
3507 | set_ftrace_early_graph(ftrace_graph_buf); | |
3508 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2af15d6a SR |
3509 | } |
3510 | ||
fc13cb0c | 3511 | int ftrace_regex_release(struct inode *inode, struct file *file) |
5072c59f SR |
3512 | { |
3513 | struct seq_file *m = (struct seq_file *)file->private_data; | |
3514 | struct ftrace_iterator *iter; | |
33dc9b12 | 3515 | struct ftrace_hash **orig_hash; |
689fd8b6 | 3516 | struct trace_parser *parser; |
ed926f9b | 3517 | int filter_hash; |
33dc9b12 | 3518 | int ret; |
5072c59f | 3519 | |
41c52c0d | 3520 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
3521 | if (file->f_mode & FMODE_READ) { |
3522 | iter = m->private; | |
3523 | ||
3524 | seq_release(inode, file); | |
3525 | } else | |
3526 | iter = file->private_data; | |
3527 | ||
689fd8b6 | 3528 | parser = &iter->parser; |
3529 | if (trace_parser_loaded(parser)) { | |
3530 | parser->buffer[parser->idx] = 0; | |
1cf41dd7 | 3531 | ftrace_match_records(iter->hash, parser->buffer, parser->idx); |
5072c59f SR |
3532 | } |
3533 | ||
689fd8b6 | 3534 | trace_parser_put(parser); |
689fd8b6 | 3535 | |
058e297d | 3536 | if (file->f_mode & FMODE_WRITE) { |
ed926f9b SR |
3537 | filter_hash = !!(iter->flags & FTRACE_ITER_FILTER); |
3538 | ||
3539 | if (filter_hash) | |
33dc9b12 | 3540 | orig_hash = &iter->ops->filter_hash; |
ed926f9b SR |
3541 | else |
3542 | orig_hash = &iter->ops->notrace_hash; | |
33dc9b12 | 3543 | |
058e297d | 3544 | mutex_lock(&ftrace_lock); |
41fb61c2 SR |
3545 | ret = ftrace_hash_move(iter->ops, filter_hash, |
3546 | orig_hash, iter->hash); | |
3547 | if (!ret && (iter->ops->flags & FTRACE_OPS_FL_ENABLED) | |
3548 | && ftrace_enabled) | |
30fb6aa7 | 3549 | ftrace_run_update_code(FTRACE_UPDATE_CALLS); |
41fb61c2 | 3550 | |
058e297d SR |
3551 | mutex_unlock(&ftrace_lock); |
3552 | } | |
33dc9b12 SR |
3553 | free_ftrace_hash(iter->hash); |
3554 | kfree(iter); | |
058e297d | 3555 | |
41c52c0d | 3556 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
3557 | return 0; |
3558 | } | |
3559 | ||
5e2336a0 | 3560 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
3561 | .open = ftrace_avail_open, |
3562 | .read = seq_read, | |
3563 | .llseek = seq_lseek, | |
3be04b47 | 3564 | .release = seq_release_private, |
5072c59f SR |
3565 | }; |
3566 | ||
647bcd03 SR |
3567 | static const struct file_operations ftrace_enabled_fops = { |
3568 | .open = ftrace_enabled_open, | |
3569 | .read = seq_read, | |
3570 | .llseek = seq_lseek, | |
3571 | .release = seq_release_private, | |
3572 | }; | |
3573 | ||
5e2336a0 | 3574 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 3575 | .open = ftrace_filter_open, |
850a80cf | 3576 | .read = seq_read, |
5072c59f | 3577 | .write = ftrace_filter_write, |
98c4fd04 | 3578 | .llseek = ftrace_regex_lseek, |
1cf41dd7 | 3579 | .release = ftrace_regex_release, |
5072c59f SR |
3580 | }; |
3581 | ||
5e2336a0 | 3582 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 3583 | .open = ftrace_notrace_open, |
850a80cf | 3584 | .read = seq_read, |
41c52c0d SR |
3585 | .write = ftrace_notrace_write, |
3586 | .llseek = ftrace_regex_lseek, | |
1cf41dd7 | 3587 | .release = ftrace_regex_release, |
41c52c0d SR |
3588 | }; |
3589 | ||
ea4e2bc4 SR |
3590 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
3591 | ||
3592 | static DEFINE_MUTEX(graph_lock); | |
3593 | ||
3594 | int ftrace_graph_count; | |
c7c6b1fe | 3595 | int ftrace_graph_filter_enabled; |
ea4e2bc4 SR |
3596 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
3597 | ||
3598 | static void * | |
85951842 | 3599 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 3600 | { |
85951842 | 3601 | if (*pos >= ftrace_graph_count) |
ea4e2bc4 | 3602 | return NULL; |
a4ec5e0c | 3603 | return &ftrace_graph_funcs[*pos]; |
85951842 | 3604 | } |
ea4e2bc4 | 3605 | |
85951842 LZ |
3606 | static void * |
3607 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
3608 | { | |
3609 | (*pos)++; | |
3610 | return __g_next(m, pos); | |
ea4e2bc4 SR |
3611 | } |
3612 | ||
3613 | static void *g_start(struct seq_file *m, loff_t *pos) | |
3614 | { | |
ea4e2bc4 SR |
3615 | mutex_lock(&graph_lock); |
3616 | ||
f9349a8f | 3617 | /* Nothing, tell g_show to print all functions are enabled */ |
c7c6b1fe | 3618 | if (!ftrace_graph_filter_enabled && !*pos) |
f9349a8f FW |
3619 | return (void *)1; |
3620 | ||
85951842 | 3621 | return __g_next(m, pos); |
ea4e2bc4 SR |
3622 | } |
3623 | ||
3624 | static void g_stop(struct seq_file *m, void *p) | |
3625 | { | |
3626 | mutex_unlock(&graph_lock); | |
3627 | } | |
3628 | ||
3629 | static int g_show(struct seq_file *m, void *v) | |
3630 | { | |
3631 | unsigned long *ptr = v; | |
ea4e2bc4 SR |
3632 | |
3633 | if (!ptr) | |
3634 | return 0; | |
3635 | ||
f9349a8f FW |
3636 | if (ptr == (unsigned long *)1) { |
3637 | seq_printf(m, "#### all functions enabled ####\n"); | |
3638 | return 0; | |
3639 | } | |
3640 | ||
b375a11a | 3641 | seq_printf(m, "%ps\n", (void *)*ptr); |
ea4e2bc4 SR |
3642 | |
3643 | return 0; | |
3644 | } | |
3645 | ||
88e9d34c | 3646 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
3647 | .start = g_start, |
3648 | .next = g_next, | |
3649 | .stop = g_stop, | |
3650 | .show = g_show, | |
3651 | }; | |
3652 | ||
3653 | static int | |
3654 | ftrace_graph_open(struct inode *inode, struct file *file) | |
3655 | { | |
3656 | int ret = 0; | |
3657 | ||
3658 | if (unlikely(ftrace_disabled)) | |
3659 | return -ENODEV; | |
3660 | ||
3661 | mutex_lock(&graph_lock); | |
3662 | if ((file->f_mode & FMODE_WRITE) && | |
8650ae32 | 3663 | (file->f_flags & O_TRUNC)) { |
c7c6b1fe | 3664 | ftrace_graph_filter_enabled = 0; |
ea4e2bc4 SR |
3665 | ftrace_graph_count = 0; |
3666 | memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); | |
3667 | } | |
a4ec5e0c | 3668 | mutex_unlock(&graph_lock); |
ea4e2bc4 | 3669 | |
a4ec5e0c | 3670 | if (file->f_mode & FMODE_READ) |
ea4e2bc4 | 3671 | ret = seq_open(file, &ftrace_graph_seq_ops); |
ea4e2bc4 SR |
3672 | |
3673 | return ret; | |
3674 | } | |
3675 | ||
87827111 LZ |
3676 | static int |
3677 | ftrace_graph_release(struct inode *inode, struct file *file) | |
3678 | { | |
3679 | if (file->f_mode & FMODE_READ) | |
3680 | seq_release(inode, file); | |
3681 | return 0; | |
3682 | } | |
3683 | ||
ea4e2bc4 | 3684 | static int |
f9349a8f | 3685 | ftrace_set_func(unsigned long *array, int *idx, char *buffer) |
ea4e2bc4 | 3686 | { |
ea4e2bc4 SR |
3687 | struct dyn_ftrace *rec; |
3688 | struct ftrace_page *pg; | |
f9349a8f | 3689 | int search_len; |
c7c6b1fe | 3690 | int fail = 1; |
f9349a8f FW |
3691 | int type, not; |
3692 | char *search; | |
3693 | bool exists; | |
3694 | int i; | |
ea4e2bc4 | 3695 | |
f9349a8f | 3696 | /* decode regex */ |
3f6fe06d | 3697 | type = filter_parse_regex(buffer, strlen(buffer), &search, ¬); |
c7c6b1fe LZ |
3698 | if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS) |
3699 | return -EBUSY; | |
f9349a8f FW |
3700 | |
3701 | search_len = strlen(search); | |
3702 | ||
52baf119 | 3703 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
3704 | |
3705 | if (unlikely(ftrace_disabled)) { | |
3706 | mutex_unlock(&ftrace_lock); | |
3707 | return -ENODEV; | |
3708 | } | |
3709 | ||
265c831c SR |
3710 | do_for_each_ftrace_rec(pg, rec) { |
3711 | ||
b9df92d2 | 3712 | if (ftrace_match_record(rec, NULL, search, search_len, type)) { |
c7c6b1fe | 3713 | /* if it is in the array */ |
f9349a8f | 3714 | exists = false; |
c7c6b1fe | 3715 | for (i = 0; i < *idx; i++) { |
f9349a8f FW |
3716 | if (array[i] == rec->ip) { |
3717 | exists = true; | |
265c831c SR |
3718 | break; |
3719 | } | |
c7c6b1fe LZ |
3720 | } |
3721 | ||
3722 | if (!not) { | |
3723 | fail = 0; | |
3724 | if (!exists) { | |
3725 | array[(*idx)++] = rec->ip; | |
3726 | if (*idx >= FTRACE_GRAPH_MAX_FUNCS) | |
3727 | goto out; | |
3728 | } | |
3729 | } else { | |
3730 | if (exists) { | |
3731 | array[i] = array[--(*idx)]; | |
3732 | array[*idx] = 0; | |
3733 | fail = 0; | |
3734 | } | |
3735 | } | |
ea4e2bc4 | 3736 | } |
265c831c | 3737 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 3738 | out: |
52baf119 | 3739 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 3740 | |
c7c6b1fe LZ |
3741 | if (fail) |
3742 | return -EINVAL; | |
3743 | ||
3744 | ftrace_graph_filter_enabled = 1; | |
3745 | return 0; | |
ea4e2bc4 SR |
3746 | } |
3747 | ||
3748 | static ssize_t | |
3749 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
3750 | size_t cnt, loff_t *ppos) | |
3751 | { | |
689fd8b6 | 3752 | struct trace_parser parser; |
4ba7978e | 3753 | ssize_t read, ret; |
ea4e2bc4 | 3754 | |
c7c6b1fe | 3755 | if (!cnt) |
ea4e2bc4 SR |
3756 | return 0; |
3757 | ||
3758 | mutex_lock(&graph_lock); | |
3759 | ||
689fd8b6 | 3760 | if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) { |
3761 | ret = -ENOMEM; | |
1eb90f13 | 3762 | goto out_unlock; |
ea4e2bc4 SR |
3763 | } |
3764 | ||
689fd8b6 | 3765 | read = trace_get_user(&parser, ubuf, cnt, ppos); |
ea4e2bc4 | 3766 | |
4ba7978e | 3767 | if (read >= 0 && trace_parser_loaded((&parser))) { |
689fd8b6 | 3768 | parser.buffer[parser.idx] = 0; |
3769 | ||
3770 | /* we allow only one expression at a time */ | |
a4ec5e0c | 3771 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, |
689fd8b6 | 3772 | parser.buffer); |
ea4e2bc4 | 3773 | if (ret) |
1eb90f13 | 3774 | goto out_free; |
ea4e2bc4 | 3775 | } |
ea4e2bc4 SR |
3776 | |
3777 | ret = read; | |
1eb90f13 LZ |
3778 | |
3779 | out_free: | |
689fd8b6 | 3780 | trace_parser_put(&parser); |
1eb90f13 | 3781 | out_unlock: |
ea4e2bc4 SR |
3782 | mutex_unlock(&graph_lock); |
3783 | ||
3784 | return ret; | |
3785 | } | |
3786 | ||
3787 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
3788 | .open = ftrace_graph_open, |
3789 | .read = seq_read, | |
3790 | .write = ftrace_graph_write, | |
3791 | .release = ftrace_graph_release, | |
6038f373 | 3792 | .llseek = seq_lseek, |
ea4e2bc4 SR |
3793 | }; |
3794 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
3795 | ||
df4fc315 | 3796 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 3797 | { |
5072c59f | 3798 | |
5452af66 FW |
3799 | trace_create_file("available_filter_functions", 0444, |
3800 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 3801 | |
647bcd03 SR |
3802 | trace_create_file("enabled_functions", 0444, |
3803 | d_tracer, NULL, &ftrace_enabled_fops); | |
3804 | ||
5452af66 FW |
3805 | trace_create_file("set_ftrace_filter", 0644, d_tracer, |
3806 | NULL, &ftrace_filter_fops); | |
41c52c0d | 3807 | |
5452af66 | 3808 | trace_create_file("set_ftrace_notrace", 0644, d_tracer, |
41c52c0d | 3809 | NULL, &ftrace_notrace_fops); |
ad90c0e3 | 3810 | |
ea4e2bc4 | 3811 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5452af66 | 3812 | trace_create_file("set_graph_function", 0444, d_tracer, |
ea4e2bc4 SR |
3813 | NULL, |
3814 | &ftrace_graph_fops); | |
ea4e2bc4 SR |
3815 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
3816 | ||
5072c59f SR |
3817 | return 0; |
3818 | } | |
3819 | ||
9fd49328 | 3820 | static int ftrace_cmp_ips(const void *a, const void *b) |
68950619 | 3821 | { |
9fd49328 SR |
3822 | const unsigned long *ipa = a; |
3823 | const unsigned long *ipb = b; | |
68950619 | 3824 | |
9fd49328 SR |
3825 | if (*ipa > *ipb) |
3826 | return 1; | |
3827 | if (*ipa < *ipb) | |
3828 | return -1; | |
3829 | return 0; | |
3830 | } | |
3831 | ||
3832 | static void ftrace_swap_ips(void *a, void *b, int size) | |
3833 | { | |
3834 | unsigned long *ipa = a; | |
3835 | unsigned long *ipb = b; | |
3836 | unsigned long t; | |
3837 | ||
3838 | t = *ipa; | |
3839 | *ipa = *ipb; | |
3840 | *ipb = t; | |
68950619 SR |
3841 | } |
3842 | ||
5cb084bb | 3843 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 3844 | unsigned long *start, |
68bf21aa SR |
3845 | unsigned long *end) |
3846 | { | |
706c81f8 | 3847 | struct ftrace_page *start_pg; |
a7900875 | 3848 | struct ftrace_page *pg; |
706c81f8 | 3849 | struct dyn_ftrace *rec; |
a7900875 | 3850 | unsigned long count; |
68bf21aa SR |
3851 | unsigned long *p; |
3852 | unsigned long addr; | |
4376cac6 | 3853 | unsigned long flags = 0; /* Shut up gcc */ |
a7900875 SR |
3854 | int ret = -ENOMEM; |
3855 | ||
3856 | count = end - start; | |
3857 | ||
3858 | if (!count) | |
3859 | return 0; | |
3860 | ||
9fd49328 SR |
3861 | sort(start, count, sizeof(*start), |
3862 | ftrace_cmp_ips, ftrace_swap_ips); | |
3863 | ||
706c81f8 SR |
3864 | start_pg = ftrace_allocate_pages(count); |
3865 | if (!start_pg) | |
a7900875 | 3866 | return -ENOMEM; |
68bf21aa | 3867 | |
e6ea44e9 | 3868 | mutex_lock(&ftrace_lock); |
a7900875 | 3869 | |
32082309 SR |
3870 | /* |
3871 | * Core and each module needs their own pages, as | |
3872 | * modules will free them when they are removed. | |
3873 | * Force a new page to be allocated for modules. | |
3874 | */ | |
a7900875 SR |
3875 | if (!mod) { |
3876 | WARN_ON(ftrace_pages || ftrace_pages_start); | |
3877 | /* First initialization */ | |
706c81f8 | 3878 | ftrace_pages = ftrace_pages_start = start_pg; |
a7900875 | 3879 | } else { |
32082309 | 3880 | if (!ftrace_pages) |
a7900875 | 3881 | goto out; |
32082309 | 3882 | |
a7900875 SR |
3883 | if (WARN_ON(ftrace_pages->next)) { |
3884 | /* Hmm, we have free pages? */ | |
3885 | while (ftrace_pages->next) | |
3886 | ftrace_pages = ftrace_pages->next; | |
32082309 | 3887 | } |
a7900875 | 3888 | |
706c81f8 | 3889 | ftrace_pages->next = start_pg; |
32082309 SR |
3890 | } |
3891 | ||
68bf21aa | 3892 | p = start; |
706c81f8 | 3893 | pg = start_pg; |
68bf21aa SR |
3894 | while (p < end) { |
3895 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
3896 | /* |
3897 | * Some architecture linkers will pad between | |
3898 | * the different mcount_loc sections of different | |
3899 | * object files to satisfy alignments. | |
3900 | * Skip any NULL pointers. | |
3901 | */ | |
3902 | if (!addr) | |
3903 | continue; | |
706c81f8 SR |
3904 | |
3905 | if (pg->index == pg->size) { | |
3906 | /* We should have allocated enough */ | |
3907 | if (WARN_ON(!pg->next)) | |
3908 | break; | |
3909 | pg = pg->next; | |
3910 | } | |
3911 | ||
3912 | rec = &pg->records[pg->index++]; | |
3913 | rec->ip = addr; | |
68bf21aa SR |
3914 | } |
3915 | ||
706c81f8 SR |
3916 | /* We should have used all pages */ |
3917 | WARN_ON(pg->next); | |
3918 | ||
3919 | /* Assign the last page to ftrace_pages */ | |
3920 | ftrace_pages = pg; | |
3921 | ||
85ae32ae | 3922 | /* These new locations need to be initialized */ |
706c81f8 | 3923 | ftrace_new_pgs = start_pg; |
85ae32ae | 3924 | |
a4f18ed1 | 3925 | /* |
4376cac6 SR |
3926 | * We only need to disable interrupts on start up |
3927 | * because we are modifying code that an interrupt | |
3928 | * may execute, and the modification is not atomic. | |
3929 | * But for modules, nothing runs the code we modify | |
3930 | * until we are finished with it, and there's no | |
3931 | * reason to cause large interrupt latencies while we do it. | |
a4f18ed1 | 3932 | */ |
4376cac6 SR |
3933 | if (!mod) |
3934 | local_irq_save(flags); | |
31e88909 | 3935 | ftrace_update_code(mod); |
4376cac6 SR |
3936 | if (!mod) |
3937 | local_irq_restore(flags); | |
a7900875 SR |
3938 | ret = 0; |
3939 | out: | |
e6ea44e9 | 3940 | mutex_unlock(&ftrace_lock); |
68bf21aa | 3941 | |
a7900875 | 3942 | return ret; |
68bf21aa SR |
3943 | } |
3944 | ||
93eb677d | 3945 | #ifdef CONFIG_MODULES |
32082309 SR |
3946 | |
3947 | #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next) | |
3948 | ||
e7247a15 | 3949 | void ftrace_release_mod(struct module *mod) |
93eb677d SR |
3950 | { |
3951 | struct dyn_ftrace *rec; | |
32082309 | 3952 | struct ftrace_page **last_pg; |
93eb677d | 3953 | struct ftrace_page *pg; |
a7900875 | 3954 | int order; |
93eb677d | 3955 | |
45a4a237 SR |
3956 | mutex_lock(&ftrace_lock); |
3957 | ||
e7247a15 | 3958 | if (ftrace_disabled) |
45a4a237 | 3959 | goto out_unlock; |
93eb677d | 3960 | |
32082309 SR |
3961 | /* |
3962 | * Each module has its own ftrace_pages, remove | |
3963 | * them from the list. | |
3964 | */ | |
3965 | last_pg = &ftrace_pages_start; | |
3966 | for (pg = ftrace_pages_start; pg; pg = *last_pg) { | |
3967 | rec = &pg->records[0]; | |
e7247a15 | 3968 | if (within_module_core(rec->ip, mod)) { |
93eb677d | 3969 | /* |
32082309 SR |
3970 | * As core pages are first, the first |
3971 | * page should never be a module page. | |
93eb677d | 3972 | */ |
32082309 SR |
3973 | if (WARN_ON(pg == ftrace_pages_start)) |
3974 | goto out_unlock; | |
3975 | ||
3976 | /* Check if we are deleting the last page */ | |
3977 | if (pg == ftrace_pages) | |
3978 | ftrace_pages = next_to_ftrace_page(last_pg); | |
3979 | ||
3980 | *last_pg = pg->next; | |
a7900875 SR |
3981 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
3982 | free_pages((unsigned long)pg->records, order); | |
3983 | kfree(pg); | |
32082309 SR |
3984 | } else |
3985 | last_pg = &pg->next; | |
3986 | } | |
45a4a237 | 3987 | out_unlock: |
93eb677d SR |
3988 | mutex_unlock(&ftrace_lock); |
3989 | } | |
3990 | ||
3991 | static void ftrace_init_module(struct module *mod, | |
3992 | unsigned long *start, unsigned long *end) | |
90d595fe | 3993 | { |
00fd61ae | 3994 | if (ftrace_disabled || start == end) |
fed1939c | 3995 | return; |
5cb084bb | 3996 | ftrace_process_locs(mod, start, end); |
90d595fe SR |
3997 | } |
3998 | ||
8c189ea6 SRRH |
3999 | static int ftrace_module_notify_enter(struct notifier_block *self, |
4000 | unsigned long val, void *data) | |
93eb677d SR |
4001 | { |
4002 | struct module *mod = data; | |
4003 | ||
8c189ea6 | 4004 | if (val == MODULE_STATE_COMING) |
93eb677d SR |
4005 | ftrace_init_module(mod, mod->ftrace_callsites, |
4006 | mod->ftrace_callsites + | |
4007 | mod->num_ftrace_callsites); | |
8c189ea6 SRRH |
4008 | return 0; |
4009 | } | |
4010 | ||
4011 | static int ftrace_module_notify_exit(struct notifier_block *self, | |
4012 | unsigned long val, void *data) | |
4013 | { | |
4014 | struct module *mod = data; | |
4015 | ||
4016 | if (val == MODULE_STATE_GOING) | |
e7247a15 | 4017 | ftrace_release_mod(mod); |
93eb677d SR |
4018 | |
4019 | return 0; | |
4020 | } | |
4021 | #else | |
8c189ea6 SRRH |
4022 | static int ftrace_module_notify_enter(struct notifier_block *self, |
4023 | unsigned long val, void *data) | |
4024 | { | |
4025 | return 0; | |
4026 | } | |
4027 | static int ftrace_module_notify_exit(struct notifier_block *self, | |
4028 | unsigned long val, void *data) | |
93eb677d SR |
4029 | { |
4030 | return 0; | |
4031 | } | |
4032 | #endif /* CONFIG_MODULES */ | |
4033 | ||
8c189ea6 SRRH |
4034 | struct notifier_block ftrace_module_enter_nb = { |
4035 | .notifier_call = ftrace_module_notify_enter, | |
c1bf08ac | 4036 | .priority = INT_MAX, /* Run before anything that can use kprobes */ |
93eb677d SR |
4037 | }; |
4038 | ||
8c189ea6 SRRH |
4039 | struct notifier_block ftrace_module_exit_nb = { |
4040 | .notifier_call = ftrace_module_notify_exit, | |
4041 | .priority = INT_MIN, /* Run after anything that can remove kprobes */ | |
4042 | }; | |
4043 | ||
68bf21aa SR |
4044 | extern unsigned long __start_mcount_loc[]; |
4045 | extern unsigned long __stop_mcount_loc[]; | |
4046 | ||
4047 | void __init ftrace_init(void) | |
4048 | { | |
4049 | unsigned long count, addr, flags; | |
4050 | int ret; | |
4051 | ||
4052 | /* Keep the ftrace pointer to the stub */ | |
4053 | addr = (unsigned long)ftrace_stub; | |
4054 | ||
4055 | local_irq_save(flags); | |
4056 | ftrace_dyn_arch_init(&addr); | |
4057 | local_irq_restore(flags); | |
4058 | ||
4059 | /* ftrace_dyn_arch_init places the return code in addr */ | |
4060 | if (addr) | |
4061 | goto failed; | |
4062 | ||
4063 | count = __stop_mcount_loc - __start_mcount_loc; | |
4064 | ||
4065 | ret = ftrace_dyn_table_alloc(count); | |
4066 | if (ret) | |
4067 | goto failed; | |
4068 | ||
4069 | last_ftrace_enabled = ftrace_enabled = 1; | |
4070 | ||
5cb084bb | 4071 | ret = ftrace_process_locs(NULL, |
31e88909 | 4072 | __start_mcount_loc, |
68bf21aa SR |
4073 | __stop_mcount_loc); |
4074 | ||
8c189ea6 SRRH |
4075 | ret = register_module_notifier(&ftrace_module_enter_nb); |
4076 | if (ret) | |
4077 | pr_warning("Failed to register trace ftrace module enter notifier\n"); | |
4078 | ||
4079 | ret = register_module_notifier(&ftrace_module_exit_nb); | |
24ed0c4b | 4080 | if (ret) |
8c189ea6 | 4081 | pr_warning("Failed to register trace ftrace module exit notifier\n"); |
93eb677d | 4082 | |
2af15d6a SR |
4083 | set_ftrace_early_filters(); |
4084 | ||
68bf21aa SR |
4085 | return; |
4086 | failed: | |
4087 | ftrace_disabled = 1; | |
4088 | } | |
68bf21aa | 4089 | |
3d083395 | 4090 | #else |
0b6e4d56 | 4091 | |
2b499381 | 4092 | static struct ftrace_ops global_ops = { |
bd69c30b | 4093 | .func = ftrace_stub, |
4740974a | 4094 | .flags = FTRACE_OPS_FL_RECURSION_SAFE, |
bd69c30b SR |
4095 | }; |
4096 | ||
0b6e4d56 FW |
4097 | static int __init ftrace_nodyn_init(void) |
4098 | { | |
4099 | ftrace_enabled = 1; | |
4100 | return 0; | |
4101 | } | |
6f415672 | 4102 | core_initcall(ftrace_nodyn_init); |
0b6e4d56 | 4103 | |
df4fc315 SR |
4104 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
4105 | static inline void ftrace_startup_enable(int command) { } | |
5a45cfe1 | 4106 | /* Keep as macros so we do not need to define the commands */ |
3b6cfdb1 SR |
4107 | # define ftrace_startup(ops, command) \ |
4108 | ({ \ | |
4109 | (ops)->flags |= FTRACE_OPS_FL_ENABLED; \ | |
4110 | 0; \ | |
4111 | }) | |
bd69c30b | 4112 | # define ftrace_shutdown(ops, command) do { } while (0) |
c7aafc54 IM |
4113 | # define ftrace_startup_sysctl() do { } while (0) |
4114 | # define ftrace_shutdown_sysctl() do { } while (0) | |
b848914c SR |
4115 | |
4116 | static inline int | |
4117 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip) | |
4118 | { | |
4119 | return 1; | |
4120 | } | |
4121 | ||
3d083395 SR |
4122 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
4123 | ||
e248491a | 4124 | static void |
2f5f6ad9 | 4125 | ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 4126 | struct ftrace_ops *op, struct pt_regs *regs) |
e248491a | 4127 | { |
e248491a JO |
4128 | if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT))) |
4129 | return; | |
4130 | ||
4131 | /* | |
4132 | * Some of the ops may be dynamically allocated, | |
4133 | * they must be freed after a synchronize_sched(). | |
4134 | */ | |
4135 | preempt_disable_notrace(); | |
4136 | trace_recursion_set(TRACE_CONTROL_BIT); | |
0a016409 | 4137 | do_for_each_ftrace_op(op, ftrace_control_list) { |
e248491a JO |
4138 | if (!ftrace_function_local_disabled(op) && |
4139 | ftrace_ops_test(op, ip)) | |
a1e2e31d | 4140 | op->func(ip, parent_ip, op, regs); |
0a016409 | 4141 | } while_for_each_ftrace_op(op); |
e248491a JO |
4142 | trace_recursion_clear(TRACE_CONTROL_BIT); |
4143 | preempt_enable_notrace(); | |
4144 | } | |
4145 | ||
4146 | static struct ftrace_ops control_ops = { | |
4147 | .func = ftrace_ops_control_func, | |
4740974a | 4148 | .flags = FTRACE_OPS_FL_RECURSION_SAFE, |
e248491a JO |
4149 | }; |
4150 | ||
2f5f6ad9 SR |
4151 | static inline void |
4152 | __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 4153 | struct ftrace_ops *ignored, struct pt_regs *regs) |
b848914c | 4154 | { |
cdbe61bf | 4155 | struct ftrace_ops *op; |
edc15caf | 4156 | int bit; |
b848914c | 4157 | |
ccf3672d SR |
4158 | if (function_trace_stop) |
4159 | return; | |
4160 | ||
edc15caf SR |
4161 | bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX); |
4162 | if (bit < 0) | |
4163 | return; | |
b1cff0ad | 4164 | |
cdbe61bf SR |
4165 | /* |
4166 | * Some of the ops may be dynamically allocated, | |
4167 | * they must be freed after a synchronize_sched(). | |
4168 | */ | |
4169 | preempt_disable_notrace(); | |
0a016409 | 4170 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
b848914c | 4171 | if (ftrace_ops_test(op, ip)) |
a1e2e31d | 4172 | op->func(ip, parent_ip, op, regs); |
0a016409 | 4173 | } while_for_each_ftrace_op(op); |
cdbe61bf | 4174 | preempt_enable_notrace(); |
edc15caf | 4175 | trace_clear_recursion(bit); |
b848914c SR |
4176 | } |
4177 | ||
2f5f6ad9 SR |
4178 | /* |
4179 | * Some archs only support passing ip and parent_ip. Even though | |
4180 | * the list function ignores the op parameter, we do not want any | |
4181 | * C side effects, where a function is called without the caller | |
4182 | * sending a third parameter. | |
a1e2e31d SR |
4183 | * Archs are to support both the regs and ftrace_ops at the same time. |
4184 | * If they support ftrace_ops, it is assumed they support regs. | |
4185 | * If call backs want to use regs, they must either check for regs | |
06aeaaea MH |
4186 | * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS. |
4187 | * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved. | |
a1e2e31d SR |
4188 | * An architecture can pass partial regs with ftrace_ops and still |
4189 | * set the ARCH_SUPPORT_FTARCE_OPS. | |
2f5f6ad9 SR |
4190 | */ |
4191 | #if ARCH_SUPPORTS_FTRACE_OPS | |
4192 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 4193 | struct ftrace_ops *op, struct pt_regs *regs) |
2f5f6ad9 | 4194 | { |
a1e2e31d | 4195 | __ftrace_ops_list_func(ip, parent_ip, NULL, regs); |
2f5f6ad9 SR |
4196 | } |
4197 | #else | |
4198 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip) | |
4199 | { | |
a1e2e31d | 4200 | __ftrace_ops_list_func(ip, parent_ip, NULL, NULL); |
2f5f6ad9 SR |
4201 | } |
4202 | #endif | |
4203 | ||
e32d8956 | 4204 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
4205 | { |
4206 | struct task_struct *p; | |
e32d8956 | 4207 | int cpu; |
978f3a45 | 4208 | |
e32d8956 SR |
4209 | get_online_cpus(); |
4210 | for_each_online_cpu(cpu) { | |
4211 | p = idle_task(cpu); | |
978f3a45 | 4212 | clear_tsk_trace_trace(p); |
e32d8956 SR |
4213 | } |
4214 | put_online_cpus(); | |
4215 | } | |
978f3a45 | 4216 | |
e32d8956 SR |
4217 | static void set_ftrace_swapper(void) |
4218 | { | |
4219 | struct task_struct *p; | |
4220 | int cpu; | |
4221 | ||
4222 | get_online_cpus(); | |
4223 | for_each_online_cpu(cpu) { | |
4224 | p = idle_task(cpu); | |
4225 | set_tsk_trace_trace(p); | |
4226 | } | |
4227 | put_online_cpus(); | |
978f3a45 SR |
4228 | } |
4229 | ||
e32d8956 SR |
4230 | static void clear_ftrace_pid(struct pid *pid) |
4231 | { | |
4232 | struct task_struct *p; | |
4233 | ||
229c4ef8 | 4234 | rcu_read_lock(); |
e32d8956 SR |
4235 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
4236 | clear_tsk_trace_trace(p); | |
4237 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
4238 | rcu_read_unlock(); |
4239 | ||
e32d8956 SR |
4240 | put_pid(pid); |
4241 | } | |
4242 | ||
4243 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
4244 | { |
4245 | struct task_struct *p; | |
4246 | ||
229c4ef8 | 4247 | rcu_read_lock(); |
978f3a45 SR |
4248 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
4249 | set_tsk_trace_trace(p); | |
4250 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 4251 | rcu_read_unlock(); |
978f3a45 SR |
4252 | } |
4253 | ||
756d17ee | 4254 | static void clear_ftrace_pid_task(struct pid *pid) |
e32d8956 | 4255 | { |
756d17ee | 4256 | if (pid == ftrace_swapper_pid) |
e32d8956 SR |
4257 | clear_ftrace_swapper(); |
4258 | else | |
756d17ee | 4259 | clear_ftrace_pid(pid); |
e32d8956 SR |
4260 | } |
4261 | ||
4262 | static void set_ftrace_pid_task(struct pid *pid) | |
4263 | { | |
4264 | if (pid == ftrace_swapper_pid) | |
4265 | set_ftrace_swapper(); | |
4266 | else | |
4267 | set_ftrace_pid(pid); | |
4268 | } | |
4269 | ||
756d17ee | 4270 | static int ftrace_pid_add(int p) |
df4fc315 | 4271 | { |
978f3a45 | 4272 | struct pid *pid; |
756d17ee | 4273 | struct ftrace_pid *fpid; |
4274 | int ret = -EINVAL; | |
df4fc315 | 4275 | |
756d17ee | 4276 | mutex_lock(&ftrace_lock); |
df4fc315 | 4277 | |
756d17ee | 4278 | if (!p) |
4279 | pid = ftrace_swapper_pid; | |
4280 | else | |
4281 | pid = find_get_pid(p); | |
df4fc315 | 4282 | |
756d17ee | 4283 | if (!pid) |
4284 | goto out; | |
df4fc315 | 4285 | |
756d17ee | 4286 | ret = 0; |
df4fc315 | 4287 | |
756d17ee | 4288 | list_for_each_entry(fpid, &ftrace_pids, list) |
4289 | if (fpid->pid == pid) | |
4290 | goto out_put; | |
978f3a45 | 4291 | |
756d17ee | 4292 | ret = -ENOMEM; |
df4fc315 | 4293 | |
756d17ee | 4294 | fpid = kmalloc(sizeof(*fpid), GFP_KERNEL); |
4295 | if (!fpid) | |
4296 | goto out_put; | |
df4fc315 | 4297 | |
756d17ee | 4298 | list_add(&fpid->list, &ftrace_pids); |
4299 | fpid->pid = pid; | |
0ef8cde5 | 4300 | |
756d17ee | 4301 | set_ftrace_pid_task(pid); |
978f3a45 | 4302 | |
756d17ee | 4303 | ftrace_update_pid_func(); |
4304 | ftrace_startup_enable(0); | |
4305 | ||
4306 | mutex_unlock(&ftrace_lock); | |
4307 | return 0; | |
4308 | ||
4309 | out_put: | |
4310 | if (pid != ftrace_swapper_pid) | |
4311 | put_pid(pid); | |
978f3a45 | 4312 | |
756d17ee | 4313 | out: |
4314 | mutex_unlock(&ftrace_lock); | |
4315 | return ret; | |
4316 | } | |
4317 | ||
4318 | static void ftrace_pid_reset(void) | |
4319 | { | |
4320 | struct ftrace_pid *fpid, *safe; | |
978f3a45 | 4321 | |
756d17ee | 4322 | mutex_lock(&ftrace_lock); |
4323 | list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) { | |
4324 | struct pid *pid = fpid->pid; | |
4325 | ||
4326 | clear_ftrace_pid_task(pid); | |
4327 | ||
4328 | list_del(&fpid->list); | |
4329 | kfree(fpid); | |
df4fc315 SR |
4330 | } |
4331 | ||
df4fc315 SR |
4332 | ftrace_update_pid_func(); |
4333 | ftrace_startup_enable(0); | |
4334 | ||
e6ea44e9 | 4335 | mutex_unlock(&ftrace_lock); |
756d17ee | 4336 | } |
df4fc315 | 4337 | |
756d17ee | 4338 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
4339 | { | |
4340 | mutex_lock(&ftrace_lock); | |
4341 | ||
4342 | if (list_empty(&ftrace_pids) && (!*pos)) | |
4343 | return (void *) 1; | |
4344 | ||
4345 | return seq_list_start(&ftrace_pids, *pos); | |
4346 | } | |
4347 | ||
4348 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
4349 | { | |
4350 | if (v == (void *)1) | |
4351 | return NULL; | |
4352 | ||
4353 | return seq_list_next(v, &ftrace_pids, pos); | |
4354 | } | |
4355 | ||
4356 | static void fpid_stop(struct seq_file *m, void *p) | |
4357 | { | |
4358 | mutex_unlock(&ftrace_lock); | |
4359 | } | |
4360 | ||
4361 | static int fpid_show(struct seq_file *m, void *v) | |
4362 | { | |
4363 | const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list); | |
4364 | ||
4365 | if (v == (void *)1) { | |
4366 | seq_printf(m, "no pid\n"); | |
4367 | return 0; | |
4368 | } | |
4369 | ||
4370 | if (fpid->pid == ftrace_swapper_pid) | |
4371 | seq_printf(m, "swapper tasks\n"); | |
4372 | else | |
4373 | seq_printf(m, "%u\n", pid_vnr(fpid->pid)); | |
4374 | ||
4375 | return 0; | |
4376 | } | |
4377 | ||
4378 | static const struct seq_operations ftrace_pid_sops = { | |
4379 | .start = fpid_start, | |
4380 | .next = fpid_next, | |
4381 | .stop = fpid_stop, | |
4382 | .show = fpid_show, | |
4383 | }; | |
4384 | ||
4385 | static int | |
4386 | ftrace_pid_open(struct inode *inode, struct file *file) | |
4387 | { | |
4388 | int ret = 0; | |
4389 | ||
4390 | if ((file->f_mode & FMODE_WRITE) && | |
4391 | (file->f_flags & O_TRUNC)) | |
4392 | ftrace_pid_reset(); | |
4393 | ||
4394 | if (file->f_mode & FMODE_READ) | |
4395 | ret = seq_open(file, &ftrace_pid_sops); | |
4396 | ||
4397 | return ret; | |
4398 | } | |
4399 | ||
df4fc315 SR |
4400 | static ssize_t |
4401 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
4402 | size_t cnt, loff_t *ppos) | |
4403 | { | |
457dc928 | 4404 | char buf[64], *tmp; |
df4fc315 SR |
4405 | long val; |
4406 | int ret; | |
4407 | ||
4408 | if (cnt >= sizeof(buf)) | |
4409 | return -EINVAL; | |
4410 | ||
4411 | if (copy_from_user(&buf, ubuf, cnt)) | |
4412 | return -EFAULT; | |
4413 | ||
4414 | buf[cnt] = 0; | |
4415 | ||
756d17ee | 4416 | /* |
4417 | * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid" | |
4418 | * to clean the filter quietly. | |
4419 | */ | |
457dc928 IM |
4420 | tmp = strstrip(buf); |
4421 | if (strlen(tmp) == 0) | |
756d17ee | 4422 | return 1; |
4423 | ||
bcd83ea6 | 4424 | ret = kstrtol(tmp, 10, &val); |
df4fc315 SR |
4425 | if (ret < 0) |
4426 | return ret; | |
4427 | ||
756d17ee | 4428 | ret = ftrace_pid_add(val); |
df4fc315 | 4429 | |
756d17ee | 4430 | return ret ? ret : cnt; |
4431 | } | |
df4fc315 | 4432 | |
756d17ee | 4433 | static int |
4434 | ftrace_pid_release(struct inode *inode, struct file *file) | |
4435 | { | |
4436 | if (file->f_mode & FMODE_READ) | |
4437 | seq_release(inode, file); | |
df4fc315 | 4438 | |
756d17ee | 4439 | return 0; |
df4fc315 SR |
4440 | } |
4441 | ||
5e2336a0 | 4442 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 4443 | .open = ftrace_pid_open, |
4444 | .write = ftrace_pid_write, | |
4445 | .read = seq_read, | |
4446 | .llseek = seq_lseek, | |
4447 | .release = ftrace_pid_release, | |
df4fc315 SR |
4448 | }; |
4449 | ||
4450 | static __init int ftrace_init_debugfs(void) | |
4451 | { | |
4452 | struct dentry *d_tracer; | |
df4fc315 SR |
4453 | |
4454 | d_tracer = tracing_init_dentry(); | |
4455 | if (!d_tracer) | |
4456 | return 0; | |
4457 | ||
4458 | ftrace_init_dyn_debugfs(d_tracer); | |
4459 | ||
5452af66 FW |
4460 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
4461 | NULL, &ftrace_pid_fops); | |
493762fc SR |
4462 | |
4463 | ftrace_profile_debugfs(d_tracer); | |
4464 | ||
df4fc315 SR |
4465 | return 0; |
4466 | } | |
df4fc315 SR |
4467 | fs_initcall(ftrace_init_debugfs); |
4468 | ||
a2bb6a3d | 4469 | /** |
81adbdc0 | 4470 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
4471 | * |
4472 | * This function should be used by panic code. It stops ftrace | |
4473 | * but in a not so nice way. If you need to simply kill ftrace | |
4474 | * from a non-atomic section, use ftrace_kill. | |
4475 | */ | |
81adbdc0 | 4476 | void ftrace_kill(void) |
a2bb6a3d SR |
4477 | { |
4478 | ftrace_disabled = 1; | |
4479 | ftrace_enabled = 0; | |
a2bb6a3d SR |
4480 | clear_ftrace_function(); |
4481 | } | |
4482 | ||
e0a413f6 SR |
4483 | /** |
4484 | * Test if ftrace is dead or not. | |
4485 | */ | |
4486 | int ftrace_is_dead(void) | |
4487 | { | |
4488 | return ftrace_disabled; | |
4489 | } | |
4490 | ||
16444a8a | 4491 | /** |
3d083395 SR |
4492 | * register_ftrace_function - register a function for profiling |
4493 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 4494 | * |
3d083395 SR |
4495 | * Register a function to be called by all functions in the |
4496 | * kernel. | |
4497 | * | |
4498 | * Note: @ops->func and all the functions it calls must be labeled | |
4499 | * with "notrace", otherwise it will go into a | |
4500 | * recursive loop. | |
16444a8a | 4501 | */ |
3d083395 | 4502 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 4503 | { |
45a4a237 | 4504 | int ret = -1; |
4eebcc81 | 4505 | |
e6ea44e9 | 4506 | mutex_lock(&ftrace_lock); |
e7d3737e | 4507 | |
b0fc494f | 4508 | ret = __register_ftrace_function(ops); |
b848914c | 4509 | if (!ret) |
a1cd6173 | 4510 | ret = ftrace_startup(ops, 0); |
b848914c | 4511 | |
e6ea44e9 | 4512 | mutex_unlock(&ftrace_lock); |
8d240dd8 | 4513 | |
b0fc494f | 4514 | return ret; |
3d083395 | 4515 | } |
cdbe61bf | 4516 | EXPORT_SYMBOL_GPL(register_ftrace_function); |
3d083395 SR |
4517 | |
4518 | /** | |
32632920 | 4519 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
4520 | * @ops - ops structure that holds the function to unregister |
4521 | * | |
4522 | * Unregister a function that was added to be called by ftrace profiling. | |
4523 | */ | |
4524 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
4525 | { | |
4526 | int ret; | |
4527 | ||
e6ea44e9 | 4528 | mutex_lock(&ftrace_lock); |
3d083395 | 4529 | ret = __unregister_ftrace_function(ops); |
b848914c SR |
4530 | if (!ret) |
4531 | ftrace_shutdown(ops, 0); | |
e6ea44e9 | 4532 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
4533 | |
4534 | return ret; | |
4535 | } | |
cdbe61bf | 4536 | EXPORT_SYMBOL_GPL(unregister_ftrace_function); |
b0fc494f | 4537 | |
e309b41d | 4538 | int |
b0fc494f | 4539 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
8d65af78 | 4540 | void __user *buffer, size_t *lenp, |
b0fc494f SR |
4541 | loff_t *ppos) |
4542 | { | |
45a4a237 | 4543 | int ret = -ENODEV; |
4eebcc81 | 4544 | |
e6ea44e9 | 4545 | mutex_lock(&ftrace_lock); |
b0fc494f | 4546 | |
45a4a237 SR |
4547 | if (unlikely(ftrace_disabled)) |
4548 | goto out; | |
4549 | ||
4550 | ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
b0fc494f | 4551 | |
a32c7765 | 4552 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
4553 | goto out; |
4554 | ||
a32c7765 | 4555 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f SR |
4556 | |
4557 | if (ftrace_enabled) { | |
4558 | ||
4559 | ftrace_startup_sysctl(); | |
4560 | ||
4561 | /* we are starting ftrace again */ | |
b848914c SR |
4562 | if (ftrace_ops_list != &ftrace_list_end) { |
4563 | if (ftrace_ops_list->next == &ftrace_list_end) | |
4564 | ftrace_trace_function = ftrace_ops_list->func; | |
b0fc494f | 4565 | else |
b848914c | 4566 | ftrace_trace_function = ftrace_ops_list_func; |
b0fc494f SR |
4567 | } |
4568 | ||
4569 | } else { | |
4570 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
4571 | ftrace_trace_function = ftrace_stub; | |
4572 | ||
4573 | ftrace_shutdown_sysctl(); | |
4574 | } | |
4575 | ||
4576 | out: | |
e6ea44e9 | 4577 | mutex_unlock(&ftrace_lock); |
3d083395 | 4578 | return ret; |
16444a8a | 4579 | } |
f17845e5 | 4580 | |
fb52607a | 4581 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 4582 | |
597af815 | 4583 | static int ftrace_graph_active; |
4a2b8dda | 4584 | static struct notifier_block ftrace_suspend_notifier; |
e7d3737e | 4585 | |
e49dc19c SR |
4586 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
4587 | { | |
4588 | return 0; | |
4589 | } | |
4590 | ||
287b6e68 FW |
4591 | /* The callbacks that hook a function */ |
4592 | trace_func_graph_ret_t ftrace_graph_return = | |
4593 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 4594 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
4595 | |
4596 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
4597 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
4598 | { | |
4599 | int i; | |
4600 | int ret = 0; | |
4601 | unsigned long flags; | |
4602 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
4603 | struct task_struct *g, *t; | |
4604 | ||
4605 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
4606 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
4607 | * sizeof(struct ftrace_ret_stack), | |
4608 | GFP_KERNEL); | |
4609 | if (!ret_stack_list[i]) { | |
4610 | start = 0; | |
4611 | end = i; | |
4612 | ret = -ENOMEM; | |
4613 | goto free; | |
4614 | } | |
4615 | } | |
4616 | ||
4617 | read_lock_irqsave(&tasklist_lock, flags); | |
4618 | do_each_thread(g, t) { | |
4619 | if (start == end) { | |
4620 | ret = -EAGAIN; | |
4621 | goto unlock; | |
4622 | } | |
4623 | ||
4624 | if (t->ret_stack == NULL) { | |
380c4b14 | 4625 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 4626 | atomic_set(&t->trace_overrun, 0); |
26c01624 SR |
4627 | t->curr_ret_stack = -1; |
4628 | /* Make sure the tasks see the -1 first: */ | |
4629 | smp_wmb(); | |
4630 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
4631 | } |
4632 | } while_each_thread(g, t); | |
4633 | ||
4634 | unlock: | |
4635 | read_unlock_irqrestore(&tasklist_lock, flags); | |
4636 | free: | |
4637 | for (i = start; i < end; i++) | |
4638 | kfree(ret_stack_list[i]); | |
4639 | return ret; | |
4640 | } | |
4641 | ||
8aef2d28 | 4642 | static void |
38516ab5 SR |
4643 | ftrace_graph_probe_sched_switch(void *ignore, |
4644 | struct task_struct *prev, struct task_struct *next) | |
8aef2d28 SR |
4645 | { |
4646 | unsigned long long timestamp; | |
4647 | int index; | |
4648 | ||
be6f164a SR |
4649 | /* |
4650 | * Does the user want to count the time a function was asleep. | |
4651 | * If so, do not update the time stamps. | |
4652 | */ | |
4653 | if (trace_flags & TRACE_ITER_SLEEP_TIME) | |
4654 | return; | |
4655 | ||
8aef2d28 SR |
4656 | timestamp = trace_clock_local(); |
4657 | ||
4658 | prev->ftrace_timestamp = timestamp; | |
4659 | ||
4660 | /* only process tasks that we timestamped */ | |
4661 | if (!next->ftrace_timestamp) | |
4662 | return; | |
4663 | ||
4664 | /* | |
4665 | * Update all the counters in next to make up for the | |
4666 | * time next was sleeping. | |
4667 | */ | |
4668 | timestamp -= next->ftrace_timestamp; | |
4669 | ||
4670 | for (index = next->curr_ret_stack; index >= 0; index--) | |
4671 | next->ret_stack[index].calltime += timestamp; | |
4672 | } | |
4673 | ||
f201ae23 | 4674 | /* Allocate a return stack for each task */ |
fb52607a | 4675 | static int start_graph_tracing(void) |
f201ae23 FW |
4676 | { |
4677 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 4678 | int ret, cpu; |
f201ae23 FW |
4679 | |
4680 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
4681 | sizeof(struct ftrace_ret_stack *), | |
4682 | GFP_KERNEL); | |
4683 | ||
4684 | if (!ret_stack_list) | |
4685 | return -ENOMEM; | |
4686 | ||
5b058bcd | 4687 | /* The cpu_boot init_task->ret_stack will never be freed */ |
179c498a SR |
4688 | for_each_online_cpu(cpu) { |
4689 | if (!idle_task(cpu)->ret_stack) | |
868baf07 | 4690 | ftrace_graph_init_idle_task(idle_task(cpu), cpu); |
179c498a | 4691 | } |
5b058bcd | 4692 | |
f201ae23 FW |
4693 | do { |
4694 | ret = alloc_retstack_tasklist(ret_stack_list); | |
4695 | } while (ret == -EAGAIN); | |
4696 | ||
8aef2d28 | 4697 | if (!ret) { |
38516ab5 | 4698 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
8aef2d28 SR |
4699 | if (ret) |
4700 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
4701 | " probe to kernel_sched_switch\n"); | |
4702 | } | |
4703 | ||
f201ae23 FW |
4704 | kfree(ret_stack_list); |
4705 | return ret; | |
4706 | } | |
4707 | ||
4a2b8dda FW |
4708 | /* |
4709 | * Hibernation protection. | |
4710 | * The state of the current task is too much unstable during | |
4711 | * suspend/restore to disk. We want to protect against that. | |
4712 | */ | |
4713 | static int | |
4714 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
4715 | void *unused) | |
4716 | { | |
4717 | switch (state) { | |
4718 | case PM_HIBERNATION_PREPARE: | |
4719 | pause_graph_tracing(); | |
4720 | break; | |
4721 | ||
4722 | case PM_POST_HIBERNATION: | |
4723 | unpause_graph_tracing(); | |
4724 | break; | |
4725 | } | |
4726 | return NOTIFY_DONE; | |
4727 | } | |
4728 | ||
287b6e68 FW |
4729 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
4730 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 4731 | { |
e7d3737e FW |
4732 | int ret = 0; |
4733 | ||
e6ea44e9 | 4734 | mutex_lock(&ftrace_lock); |
e7d3737e | 4735 | |
05ce5818 | 4736 | /* we currently allow only one tracer registered at a time */ |
597af815 | 4737 | if (ftrace_graph_active) { |
05ce5818 SR |
4738 | ret = -EBUSY; |
4739 | goto out; | |
4740 | } | |
4741 | ||
4a2b8dda FW |
4742 | ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; |
4743 | register_pm_notifier(&ftrace_suspend_notifier); | |
4744 | ||
597af815 | 4745 | ftrace_graph_active++; |
fb52607a | 4746 | ret = start_graph_tracing(); |
f201ae23 | 4747 | if (ret) { |
597af815 | 4748 | ftrace_graph_active--; |
f201ae23 FW |
4749 | goto out; |
4750 | } | |
e53a6319 | 4751 | |
287b6e68 FW |
4752 | ftrace_graph_return = retfunc; |
4753 | ftrace_graph_entry = entryfunc; | |
e53a6319 | 4754 | |
a1cd6173 | 4755 | ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET); |
e7d3737e FW |
4756 | |
4757 | out: | |
e6ea44e9 | 4758 | mutex_unlock(&ftrace_lock); |
e7d3737e | 4759 | return ret; |
15e6cb36 FW |
4760 | } |
4761 | ||
fb52607a | 4762 | void unregister_ftrace_graph(void) |
15e6cb36 | 4763 | { |
e6ea44e9 | 4764 | mutex_lock(&ftrace_lock); |
e7d3737e | 4765 | |
597af815 | 4766 | if (unlikely(!ftrace_graph_active)) |
2aad1b76 SR |
4767 | goto out; |
4768 | ||
597af815 | 4769 | ftrace_graph_active--; |
287b6e68 | 4770 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 4771 | ftrace_graph_entry = ftrace_graph_entry_stub; |
bd69c30b | 4772 | ftrace_shutdown(&global_ops, FTRACE_STOP_FUNC_RET); |
4a2b8dda | 4773 | unregister_pm_notifier(&ftrace_suspend_notifier); |
38516ab5 | 4774 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
e7d3737e | 4775 | |
2aad1b76 | 4776 | out: |
e6ea44e9 | 4777 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 4778 | } |
f201ae23 | 4779 | |
868baf07 SR |
4780 | static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack); |
4781 | ||
4782 | static void | |
4783 | graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack) | |
4784 | { | |
4785 | atomic_set(&t->tracing_graph_pause, 0); | |
4786 | atomic_set(&t->trace_overrun, 0); | |
4787 | t->ftrace_timestamp = 0; | |
25985edc | 4788 | /* make curr_ret_stack visible before we add the ret_stack */ |
868baf07 SR |
4789 | smp_wmb(); |
4790 | t->ret_stack = ret_stack; | |
4791 | } | |
4792 | ||
4793 | /* | |
4794 | * Allocate a return stack for the idle task. May be the first | |
4795 | * time through, or it may be done by CPU hotplug online. | |
4796 | */ | |
4797 | void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) | |
4798 | { | |
4799 | t->curr_ret_stack = -1; | |
4800 | /* | |
4801 | * The idle task has no parent, it either has its own | |
4802 | * stack or no stack at all. | |
4803 | */ | |
4804 | if (t->ret_stack) | |
4805 | WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu)); | |
4806 | ||
4807 | if (ftrace_graph_active) { | |
4808 | struct ftrace_ret_stack *ret_stack; | |
4809 | ||
4810 | ret_stack = per_cpu(idle_ret_stack, cpu); | |
4811 | if (!ret_stack) { | |
4812 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
4813 | * sizeof(struct ftrace_ret_stack), | |
4814 | GFP_KERNEL); | |
4815 | if (!ret_stack) | |
4816 | return; | |
4817 | per_cpu(idle_ret_stack, cpu) = ret_stack; | |
4818 | } | |
4819 | graph_init_task(t, ret_stack); | |
4820 | } | |
4821 | } | |
4822 | ||
f201ae23 | 4823 | /* Allocate a return stack for newly created task */ |
fb52607a | 4824 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 4825 | { |
84047e36 SR |
4826 | /* Make sure we do not use the parent ret_stack */ |
4827 | t->ret_stack = NULL; | |
ea14eb71 | 4828 | t->curr_ret_stack = -1; |
84047e36 | 4829 | |
597af815 | 4830 | if (ftrace_graph_active) { |
82310a32 SR |
4831 | struct ftrace_ret_stack *ret_stack; |
4832 | ||
4833 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
f201ae23 FW |
4834 | * sizeof(struct ftrace_ret_stack), |
4835 | GFP_KERNEL); | |
82310a32 | 4836 | if (!ret_stack) |
f201ae23 | 4837 | return; |
868baf07 | 4838 | graph_init_task(t, ret_stack); |
84047e36 | 4839 | } |
f201ae23 FW |
4840 | } |
4841 | ||
fb52607a | 4842 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 4843 | { |
eae849ca FW |
4844 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
4845 | ||
f201ae23 | 4846 | t->ret_stack = NULL; |
eae849ca FW |
4847 | /* NULL must become visible to IRQs before we free it: */ |
4848 | barrier(); | |
4849 | ||
4850 | kfree(ret_stack); | |
f201ae23 | 4851 | } |
14a866c5 SR |
4852 | |
4853 | void ftrace_graph_stop(void) | |
4854 | { | |
4855 | ftrace_stop(); | |
4856 | } | |
15e6cb36 | 4857 | #endif |