Commit | Line | Data |
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16444a8a ACM |
1 | /* |
2 | * Infrastructure for profiling code inserted by 'gcc -pg'. | |
3 | * | |
4 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> | |
5 | * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com> | |
6 | * | |
7 | * Originally ported from the -rt patch by: | |
8 | * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com> | |
9 | * | |
10 | * Based on code in the latency_tracer, that is: | |
11 | * | |
12 | * Copyright (C) 2004-2006 Ingo Molnar | |
6d49e352 | 13 | * Copyright (C) 2004 Nadia Yvette Chambers |
16444a8a ACM |
14 | */ |
15 | ||
3d083395 SR |
16 | #include <linux/stop_machine.h> |
17 | #include <linux/clocksource.h> | |
18 | #include <linux/kallsyms.h> | |
5072c59f | 19 | #include <linux/seq_file.h> |
4a2b8dda | 20 | #include <linux/suspend.h> |
5072c59f | 21 | #include <linux/debugfs.h> |
3d083395 | 22 | #include <linux/hardirq.h> |
2d8b820b | 23 | #include <linux/kthread.h> |
5072c59f | 24 | #include <linux/uaccess.h> |
5855fead | 25 | #include <linux/bsearch.h> |
56d82e00 | 26 | #include <linux/module.h> |
2d8b820b | 27 | #include <linux/ftrace.h> |
b0fc494f | 28 | #include <linux/sysctl.h> |
5a0e3ad6 | 29 | #include <linux/slab.h> |
5072c59f | 30 | #include <linux/ctype.h> |
68950619 | 31 | #include <linux/sort.h> |
3d083395 | 32 | #include <linux/list.h> |
59df055f | 33 | #include <linux/hash.h> |
3f379b03 | 34 | #include <linux/rcupdate.h> |
3d083395 | 35 | |
ad8d75ff | 36 | #include <trace/events/sched.h> |
8aef2d28 | 37 | |
2af15d6a | 38 | #include <asm/setup.h> |
395a59d0 | 39 | |
0706f1c4 | 40 | #include "trace_output.h" |
bac429f0 | 41 | #include "trace_stat.h" |
16444a8a | 42 | |
6912896e | 43 | #define FTRACE_WARN_ON(cond) \ |
0778d9ad SR |
44 | ({ \ |
45 | int ___r = cond; \ | |
46 | if (WARN_ON(___r)) \ | |
6912896e | 47 | ftrace_kill(); \ |
0778d9ad SR |
48 | ___r; \ |
49 | }) | |
6912896e SR |
50 | |
51 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
0778d9ad SR |
52 | ({ \ |
53 | int ___r = cond; \ | |
54 | if (WARN_ON_ONCE(___r)) \ | |
6912896e | 55 | ftrace_kill(); \ |
0778d9ad SR |
56 | ___r; \ |
57 | }) | |
6912896e | 58 | |
8fc0c701 SR |
59 | /* hash bits for specific function selection */ |
60 | #define FTRACE_HASH_BITS 7 | |
61 | #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS) | |
33dc9b12 SR |
62 | #define FTRACE_HASH_DEFAULT_BITS 10 |
63 | #define FTRACE_HASH_MAX_BITS 12 | |
8fc0c701 | 64 | |
4104d326 | 65 | #define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_CONTROL) |
e248491a | 66 | |
f04f24fb | 67 | #ifdef CONFIG_DYNAMIC_FTRACE |
33b7f99c SRRH |
68 | #define INIT_OPS_HASH(opsname) \ |
69 | .func_hash = &opsname.local_hash, \ | |
70 | .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock), | |
5f151b24 SRRH |
71 | #define ASSIGN_OPS_HASH(opsname, val) \ |
72 | .func_hash = val, \ | |
73 | .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock), | |
f04f24fb | 74 | #else |
33b7f99c | 75 | #define INIT_OPS_HASH(opsname) |
5f151b24 | 76 | #define ASSIGN_OPS_HASH(opsname, val) |
f04f24fb MH |
77 | #endif |
78 | ||
2f5f6ad9 SR |
79 | static struct ftrace_ops ftrace_list_end __read_mostly = { |
80 | .func = ftrace_stub, | |
395b97a3 | 81 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB, |
33b7f99c | 82 | INIT_OPS_HASH(ftrace_list_end) |
2f5f6ad9 SR |
83 | }; |
84 | ||
4eebcc81 SR |
85 | /* ftrace_enabled is a method to turn ftrace on or off */ |
86 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 87 | static int last_ftrace_enabled; |
b0fc494f | 88 | |
2f5f6ad9 SR |
89 | /* Current function tracing op */ |
90 | struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end; | |
405e1d83 SRRH |
91 | /* What to set function_trace_op to */ |
92 | static struct ftrace_ops *set_function_trace_op; | |
60a7ecf4 | 93 | |
756d17ee | 94 | /* List for set_ftrace_pid's pids. */ |
95 | LIST_HEAD(ftrace_pids); | |
96 | struct ftrace_pid { | |
97 | struct list_head list; | |
98 | struct pid *pid; | |
99 | }; | |
100 | ||
4eebcc81 SR |
101 | /* |
102 | * ftrace_disabled is set when an anomaly is discovered. | |
103 | * ftrace_disabled is much stronger than ftrace_enabled. | |
104 | */ | |
105 | static int ftrace_disabled __read_mostly; | |
106 | ||
52baf119 | 107 | static DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 108 | |
e248491a | 109 | static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end; |
b848914c | 110 | static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end; |
16444a8a | 111 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
df4fc315 | 112 | ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; |
2b499381 | 113 | static struct ftrace_ops global_ops; |
e248491a | 114 | static struct ftrace_ops control_ops; |
16444a8a | 115 | |
f1ff6348 SRRH |
116 | static void ftrace_ops_recurs_func(unsigned long ip, unsigned long parent_ip, |
117 | struct ftrace_ops *op, struct pt_regs *regs); | |
118 | ||
2f5f6ad9 SR |
119 | #if ARCH_SUPPORTS_FTRACE_OPS |
120 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 121 | struct ftrace_ops *op, struct pt_regs *regs); |
2f5f6ad9 SR |
122 | #else |
123 | /* See comment below, where ftrace_ops_list_func is defined */ | |
124 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip); | |
125 | #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops) | |
126 | #endif | |
b848914c | 127 | |
0a016409 SR |
128 | /* |
129 | * Traverse the ftrace_global_list, invoking all entries. The reason that we | |
1bb539ca | 130 | * can use rcu_dereference_raw_notrace() is that elements removed from this list |
0a016409 | 131 | * are simply leaked, so there is no need to interact with a grace-period |
1bb539ca | 132 | * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle |
0a016409 SR |
133 | * concurrent insertions into the ftrace_global_list. |
134 | * | |
135 | * Silly Alpha and silly pointer-speculation compiler optimizations! | |
136 | */ | |
137 | #define do_for_each_ftrace_op(op, list) \ | |
1bb539ca | 138 | op = rcu_dereference_raw_notrace(list); \ |
0a016409 SR |
139 | do |
140 | ||
141 | /* | |
142 | * Optimized for just a single item in the list (as that is the normal case). | |
143 | */ | |
144 | #define while_for_each_ftrace_op(op) \ | |
1bb539ca | 145 | while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \ |
0a016409 SR |
146 | unlikely((op) != &ftrace_list_end)) |
147 | ||
f04f24fb MH |
148 | static inline void ftrace_ops_init(struct ftrace_ops *ops) |
149 | { | |
150 | #ifdef CONFIG_DYNAMIC_FTRACE | |
151 | if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) { | |
33b7f99c SRRH |
152 | mutex_init(&ops->local_hash.regex_lock); |
153 | ops->func_hash = &ops->local_hash; | |
f04f24fb MH |
154 | ops->flags |= FTRACE_OPS_FL_INITIALIZED; |
155 | } | |
156 | #endif | |
157 | } | |
158 | ||
ea701f11 SR |
159 | /** |
160 | * ftrace_nr_registered_ops - return number of ops registered | |
161 | * | |
162 | * Returns the number of ftrace_ops registered and tracing functions | |
163 | */ | |
164 | int ftrace_nr_registered_ops(void) | |
165 | { | |
166 | struct ftrace_ops *ops; | |
167 | int cnt = 0; | |
168 | ||
169 | mutex_lock(&ftrace_lock); | |
170 | ||
171 | for (ops = ftrace_ops_list; | |
172 | ops != &ftrace_list_end; ops = ops->next) | |
173 | cnt++; | |
174 | ||
175 | mutex_unlock(&ftrace_lock); | |
176 | ||
177 | return cnt; | |
178 | } | |
179 | ||
2f5f6ad9 | 180 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 181 | struct ftrace_ops *op, struct pt_regs *regs) |
df4fc315 | 182 | { |
0ef8cde5 | 183 | if (!test_tsk_trace_trace(current)) |
df4fc315 SR |
184 | return; |
185 | ||
a1e2e31d | 186 | ftrace_pid_function(ip, parent_ip, op, regs); |
df4fc315 SR |
187 | } |
188 | ||
189 | static void set_ftrace_pid_function(ftrace_func_t func) | |
190 | { | |
191 | /* do not set ftrace_pid_function to itself! */ | |
192 | if (func != ftrace_pid_func) | |
193 | ftrace_pid_function = func; | |
194 | } | |
195 | ||
16444a8a | 196 | /** |
3d083395 | 197 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 198 | * |
3d083395 SR |
199 | * This NULLs the ftrace function and in essence stops |
200 | * tracing. There may be lag | |
16444a8a | 201 | */ |
3d083395 | 202 | void clear_ftrace_function(void) |
16444a8a | 203 | { |
3d083395 | 204 | ftrace_trace_function = ftrace_stub; |
df4fc315 | 205 | ftrace_pid_function = ftrace_stub; |
3d083395 SR |
206 | } |
207 | ||
e248491a JO |
208 | static void control_ops_disable_all(struct ftrace_ops *ops) |
209 | { | |
210 | int cpu; | |
211 | ||
212 | for_each_possible_cpu(cpu) | |
213 | *per_cpu_ptr(ops->disabled, cpu) = 1; | |
214 | } | |
215 | ||
216 | static int control_ops_alloc(struct ftrace_ops *ops) | |
217 | { | |
218 | int __percpu *disabled; | |
219 | ||
220 | disabled = alloc_percpu(int); | |
221 | if (!disabled) | |
222 | return -ENOMEM; | |
223 | ||
224 | ops->disabled = disabled; | |
225 | control_ops_disable_all(ops); | |
226 | return 0; | |
227 | } | |
228 | ||
405e1d83 SRRH |
229 | static void ftrace_sync(struct work_struct *work) |
230 | { | |
231 | /* | |
232 | * This function is just a stub to implement a hard force | |
233 | * of synchronize_sched(). This requires synchronizing | |
234 | * tasks even in userspace and idle. | |
235 | * | |
236 | * Yes, function tracing is rude. | |
237 | */ | |
238 | } | |
239 | ||
240 | static void ftrace_sync_ipi(void *data) | |
241 | { | |
242 | /* Probably not needed, but do it anyway */ | |
243 | smp_rmb(); | |
244 | } | |
245 | ||
23a8e844 SRRH |
246 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
247 | static void update_function_graph_func(void); | |
248 | #else | |
249 | static inline void update_function_graph_func(void) { } | |
250 | #endif | |
251 | ||
2b499381 SR |
252 | static void update_ftrace_function(void) |
253 | { | |
254 | ftrace_func_t func; | |
255 | ||
f7aad4e1 SRRH |
256 | /* |
257 | * Prepare the ftrace_ops that the arch callback will use. | |
258 | * If there's only one ftrace_ops registered, the ftrace_ops_list | |
259 | * will point to the ops we want. | |
260 | */ | |
261 | set_function_trace_op = ftrace_ops_list; | |
262 | ||
263 | /* If there's no ftrace_ops registered, just call the stub function */ | |
264 | if (ftrace_ops_list == &ftrace_list_end) { | |
265 | func = ftrace_stub; | |
266 | ||
cdbe61bf SR |
267 | /* |
268 | * If we are at the end of the list and this ops is | |
4740974a SR |
269 | * recursion safe and not dynamic and the arch supports passing ops, |
270 | * then have the mcount trampoline call the function directly. | |
cdbe61bf | 271 | */ |
f7aad4e1 | 272 | } else if (ftrace_ops_list->next == &ftrace_list_end) { |
87354059 | 273 | func = ftrace_ops_get_func(ftrace_ops_list); |
f7aad4e1 | 274 | |
2f5f6ad9 SR |
275 | } else { |
276 | /* Just use the default ftrace_ops */ | |
405e1d83 | 277 | set_function_trace_op = &ftrace_list_end; |
b848914c | 278 | func = ftrace_ops_list_func; |
2f5f6ad9 | 279 | } |
2b499381 | 280 | |
5f8bf2d2 SRRH |
281 | update_function_graph_func(); |
282 | ||
405e1d83 SRRH |
283 | /* If there's no change, then do nothing more here */ |
284 | if (ftrace_trace_function == func) | |
285 | return; | |
286 | ||
287 | /* | |
288 | * If we are using the list function, it doesn't care | |
289 | * about the function_trace_ops. | |
290 | */ | |
291 | if (func == ftrace_ops_list_func) { | |
292 | ftrace_trace_function = func; | |
293 | /* | |
294 | * Don't even bother setting function_trace_ops, | |
295 | * it would be racy to do so anyway. | |
296 | */ | |
297 | return; | |
298 | } | |
299 | ||
300 | #ifndef CONFIG_DYNAMIC_FTRACE | |
301 | /* | |
302 | * For static tracing, we need to be a bit more careful. | |
303 | * The function change takes affect immediately. Thus, | |
304 | * we need to coorditate the setting of the function_trace_ops | |
305 | * with the setting of the ftrace_trace_function. | |
306 | * | |
307 | * Set the function to the list ops, which will call the | |
308 | * function we want, albeit indirectly, but it handles the | |
309 | * ftrace_ops and doesn't depend on function_trace_op. | |
310 | */ | |
311 | ftrace_trace_function = ftrace_ops_list_func; | |
312 | /* | |
313 | * Make sure all CPUs see this. Yes this is slow, but static | |
314 | * tracing is slow and nasty to have enabled. | |
315 | */ | |
316 | schedule_on_each_cpu(ftrace_sync); | |
317 | /* Now all cpus are using the list ops. */ | |
318 | function_trace_op = set_function_trace_op; | |
319 | /* Make sure the function_trace_op is visible on all CPUs */ | |
320 | smp_wmb(); | |
321 | /* Nasty way to force a rmb on all cpus */ | |
322 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
323 | /* OK, we are all set to update the ftrace_trace_function now! */ | |
324 | #endif /* !CONFIG_DYNAMIC_FTRACE */ | |
325 | ||
491d0dcf | 326 | ftrace_trace_function = func; |
491d0dcf SR |
327 | } |
328 | ||
7eea4fce JW |
329 | int using_ftrace_ops_list_func(void) |
330 | { | |
331 | return ftrace_trace_function == ftrace_ops_list_func; | |
332 | } | |
333 | ||
2b499381 | 334 | static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
3d083395 | 335 | { |
2b499381 | 336 | ops->next = *list; |
16444a8a | 337 | /* |
b848914c | 338 | * We are entering ops into the list but another |
16444a8a ACM |
339 | * CPU might be walking that list. We need to make sure |
340 | * the ops->next pointer is valid before another CPU sees | |
b848914c | 341 | * the ops pointer included into the list. |
16444a8a | 342 | */ |
2b499381 | 343 | rcu_assign_pointer(*list, ops); |
16444a8a ACM |
344 | } |
345 | ||
2b499381 | 346 | static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
16444a8a | 347 | { |
16444a8a | 348 | struct ftrace_ops **p; |
16444a8a ACM |
349 | |
350 | /* | |
3d083395 SR |
351 | * If we are removing the last function, then simply point |
352 | * to the ftrace_stub. | |
16444a8a | 353 | */ |
2b499381 SR |
354 | if (*list == ops && ops->next == &ftrace_list_end) { |
355 | *list = &ftrace_list_end; | |
e6ea44e9 | 356 | return 0; |
16444a8a ACM |
357 | } |
358 | ||
2b499381 | 359 | for (p = list; *p != &ftrace_list_end; p = &(*p)->next) |
16444a8a ACM |
360 | if (*p == ops) |
361 | break; | |
362 | ||
e6ea44e9 SR |
363 | if (*p != ops) |
364 | return -1; | |
16444a8a ACM |
365 | |
366 | *p = (*p)->next; | |
2b499381 SR |
367 | return 0; |
368 | } | |
16444a8a | 369 | |
e248491a JO |
370 | static void add_ftrace_list_ops(struct ftrace_ops **list, |
371 | struct ftrace_ops *main_ops, | |
372 | struct ftrace_ops *ops) | |
373 | { | |
374 | int first = *list == &ftrace_list_end; | |
375 | add_ftrace_ops(list, ops); | |
376 | if (first) | |
377 | add_ftrace_ops(&ftrace_ops_list, main_ops); | |
378 | } | |
379 | ||
380 | static int remove_ftrace_list_ops(struct ftrace_ops **list, | |
381 | struct ftrace_ops *main_ops, | |
382 | struct ftrace_ops *ops) | |
383 | { | |
384 | int ret = remove_ftrace_ops(list, ops); | |
385 | if (!ret && *list == &ftrace_list_end) | |
386 | ret = remove_ftrace_ops(&ftrace_ops_list, main_ops); | |
387 | return ret; | |
388 | } | |
389 | ||
f3bea491 SRRH |
390 | static void ftrace_update_trampoline(struct ftrace_ops *ops); |
391 | ||
2b499381 SR |
392 | static int __register_ftrace_function(struct ftrace_ops *ops) |
393 | { | |
591dffda SRRH |
394 | if (ops->flags & FTRACE_OPS_FL_DELETED) |
395 | return -EINVAL; | |
396 | ||
b848914c SR |
397 | if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) |
398 | return -EBUSY; | |
399 | ||
06aeaaea | 400 | #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
08f6fba5 SR |
401 | /* |
402 | * If the ftrace_ops specifies SAVE_REGS, then it only can be used | |
403 | * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set. | |
404 | * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant. | |
405 | */ | |
406 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS && | |
407 | !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)) | |
408 | return -EINVAL; | |
409 | ||
410 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED) | |
411 | ops->flags |= FTRACE_OPS_FL_SAVE_REGS; | |
412 | #endif | |
413 | ||
cdbe61bf SR |
414 | if (!core_kernel_data((unsigned long)ops)) |
415 | ops->flags |= FTRACE_OPS_FL_DYNAMIC; | |
416 | ||
4104d326 | 417 | if (ops->flags & FTRACE_OPS_FL_CONTROL) { |
e248491a JO |
418 | if (control_ops_alloc(ops)) |
419 | return -ENOMEM; | |
420 | add_ftrace_list_ops(&ftrace_control_list, &control_ops, ops); | |
b848914c SR |
421 | } else |
422 | add_ftrace_ops(&ftrace_ops_list, ops); | |
423 | ||
f3bea491 SRRH |
424 | ftrace_update_trampoline(ops); |
425 | ||
2b499381 SR |
426 | if (ftrace_enabled) |
427 | update_ftrace_function(); | |
428 | ||
429 | return 0; | |
430 | } | |
431 | ||
432 | static int __unregister_ftrace_function(struct ftrace_ops *ops) | |
433 | { | |
434 | int ret; | |
435 | ||
b848914c SR |
436 | if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) |
437 | return -EBUSY; | |
438 | ||
4104d326 | 439 | if (ops->flags & FTRACE_OPS_FL_CONTROL) { |
e248491a JO |
440 | ret = remove_ftrace_list_ops(&ftrace_control_list, |
441 | &control_ops, ops); | |
b848914c SR |
442 | } else |
443 | ret = remove_ftrace_ops(&ftrace_ops_list, ops); | |
444 | ||
2b499381 SR |
445 | if (ret < 0) |
446 | return ret; | |
b848914c | 447 | |
491d0dcf SR |
448 | if (ftrace_enabled) |
449 | update_ftrace_function(); | |
16444a8a | 450 | |
e6ea44e9 | 451 | return 0; |
3d083395 SR |
452 | } |
453 | ||
df4fc315 SR |
454 | static void ftrace_update_pid_func(void) |
455 | { | |
491d0dcf | 456 | /* Only do something if we are tracing something */ |
df4fc315 | 457 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 458 | return; |
df4fc315 | 459 | |
491d0dcf | 460 | update_ftrace_function(); |
df4fc315 SR |
461 | } |
462 | ||
493762fc SR |
463 | #ifdef CONFIG_FUNCTION_PROFILER |
464 | struct ftrace_profile { | |
465 | struct hlist_node node; | |
466 | unsigned long ip; | |
467 | unsigned long counter; | |
0706f1c4 SR |
468 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
469 | unsigned long long time; | |
e330b3bc | 470 | unsigned long long time_squared; |
0706f1c4 | 471 | #endif |
8fc0c701 SR |
472 | }; |
473 | ||
493762fc SR |
474 | struct ftrace_profile_page { |
475 | struct ftrace_profile_page *next; | |
476 | unsigned long index; | |
477 | struct ftrace_profile records[]; | |
d61f82d0 SR |
478 | }; |
479 | ||
cafb168a SR |
480 | struct ftrace_profile_stat { |
481 | atomic_t disabled; | |
482 | struct hlist_head *hash; | |
483 | struct ftrace_profile_page *pages; | |
484 | struct ftrace_profile_page *start; | |
485 | struct tracer_stat stat; | |
486 | }; | |
487 | ||
493762fc SR |
488 | #define PROFILE_RECORDS_SIZE \ |
489 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 490 | |
493762fc SR |
491 | #define PROFILES_PER_PAGE \ |
492 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 493 | |
fb9fb015 SR |
494 | static int ftrace_profile_enabled __read_mostly; |
495 | ||
496 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
497 | static DEFINE_MUTEX(ftrace_profile_lock); |
498 | ||
cafb168a | 499 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc | 500 | |
20079ebe NK |
501 | #define FTRACE_PROFILE_HASH_BITS 10 |
502 | #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS) | |
493762fc | 503 | |
bac429f0 SR |
504 | static void * |
505 | function_stat_next(void *v, int idx) | |
506 | { | |
493762fc SR |
507 | struct ftrace_profile *rec = v; |
508 | struct ftrace_profile_page *pg; | |
bac429f0 | 509 | |
493762fc | 510 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
511 | |
512 | again: | |
0296e425 LZ |
513 | if (idx != 0) |
514 | rec++; | |
515 | ||
bac429f0 SR |
516 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
517 | pg = pg->next; | |
518 | if (!pg) | |
519 | return NULL; | |
520 | rec = &pg->records[0]; | |
493762fc SR |
521 | if (!rec->counter) |
522 | goto again; | |
bac429f0 SR |
523 | } |
524 | ||
bac429f0 SR |
525 | return rec; |
526 | } | |
527 | ||
528 | static void *function_stat_start(struct tracer_stat *trace) | |
529 | { | |
cafb168a SR |
530 | struct ftrace_profile_stat *stat = |
531 | container_of(trace, struct ftrace_profile_stat, stat); | |
532 | ||
533 | if (!stat || !stat->start) | |
534 | return NULL; | |
535 | ||
536 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
537 | } |
538 | ||
0706f1c4 SR |
539 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
540 | /* function graph compares on total time */ | |
541 | static int function_stat_cmp(void *p1, void *p2) | |
542 | { | |
543 | struct ftrace_profile *a = p1; | |
544 | struct ftrace_profile *b = p2; | |
545 | ||
546 | if (a->time < b->time) | |
547 | return -1; | |
548 | if (a->time > b->time) | |
549 | return 1; | |
550 | else | |
551 | return 0; | |
552 | } | |
553 | #else | |
554 | /* not function graph compares against hits */ | |
bac429f0 SR |
555 | static int function_stat_cmp(void *p1, void *p2) |
556 | { | |
493762fc SR |
557 | struct ftrace_profile *a = p1; |
558 | struct ftrace_profile *b = p2; | |
bac429f0 SR |
559 | |
560 | if (a->counter < b->counter) | |
561 | return -1; | |
562 | if (a->counter > b->counter) | |
563 | return 1; | |
564 | else | |
565 | return 0; | |
566 | } | |
0706f1c4 | 567 | #endif |
bac429f0 SR |
568 | |
569 | static int function_stat_headers(struct seq_file *m) | |
570 | { | |
0706f1c4 | 571 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b | 572 | seq_printf(m, " Function " |
e330b3bc | 573 | "Hit Time Avg s^2\n" |
34886c8b | 574 | " -------- " |
e330b3bc | 575 | "--- ---- --- ---\n"); |
0706f1c4 | 576 | #else |
bac429f0 SR |
577 | seq_printf(m, " Function Hit\n" |
578 | " -------- ---\n"); | |
0706f1c4 | 579 | #endif |
bac429f0 SR |
580 | return 0; |
581 | } | |
582 | ||
583 | static int function_stat_show(struct seq_file *m, void *v) | |
584 | { | |
493762fc | 585 | struct ftrace_profile *rec = v; |
bac429f0 | 586 | char str[KSYM_SYMBOL_LEN]; |
3aaba20f | 587 | int ret = 0; |
0706f1c4 | 588 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
589 | static struct trace_seq s; |
590 | unsigned long long avg; | |
e330b3bc | 591 | unsigned long long stddev; |
0706f1c4 | 592 | #endif |
3aaba20f LZ |
593 | mutex_lock(&ftrace_profile_lock); |
594 | ||
595 | /* we raced with function_profile_reset() */ | |
596 | if (unlikely(rec->counter == 0)) { | |
597 | ret = -EBUSY; | |
598 | goto out; | |
599 | } | |
bac429f0 SR |
600 | |
601 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
0706f1c4 SR |
602 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
603 | ||
604 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
605 | seq_printf(m, " "); | |
34886c8b SR |
606 | avg = rec->time; |
607 | do_div(avg, rec->counter); | |
608 | ||
e330b3bc CD |
609 | /* Sample standard deviation (s^2) */ |
610 | if (rec->counter <= 1) | |
611 | stddev = 0; | |
612 | else { | |
52d85d76 JL |
613 | /* |
614 | * Apply Welford's method: | |
615 | * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2) | |
616 | */ | |
617 | stddev = rec->counter * rec->time_squared - | |
618 | rec->time * rec->time; | |
619 | ||
e330b3bc CD |
620 | /* |
621 | * Divide only 1000 for ns^2 -> us^2 conversion. | |
622 | * trace_print_graph_duration will divide 1000 again. | |
623 | */ | |
52d85d76 | 624 | do_div(stddev, rec->counter * (rec->counter - 1) * 1000); |
e330b3bc CD |
625 | } |
626 | ||
34886c8b SR |
627 | trace_seq_init(&s); |
628 | trace_print_graph_duration(rec->time, &s); | |
629 | trace_seq_puts(&s, " "); | |
630 | trace_print_graph_duration(avg, &s); | |
e330b3bc CD |
631 | trace_seq_puts(&s, " "); |
632 | trace_print_graph_duration(stddev, &s); | |
0706f1c4 | 633 | trace_print_seq(m, &s); |
0706f1c4 SR |
634 | #endif |
635 | seq_putc(m, '\n'); | |
3aaba20f LZ |
636 | out: |
637 | mutex_unlock(&ftrace_profile_lock); | |
bac429f0 | 638 | |
3aaba20f | 639 | return ret; |
bac429f0 SR |
640 | } |
641 | ||
cafb168a | 642 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 643 | { |
493762fc | 644 | struct ftrace_profile_page *pg; |
bac429f0 | 645 | |
cafb168a | 646 | pg = stat->pages = stat->start; |
bac429f0 | 647 | |
493762fc SR |
648 | while (pg) { |
649 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
650 | pg->index = 0; | |
651 | pg = pg->next; | |
bac429f0 SR |
652 | } |
653 | ||
cafb168a | 654 | memset(stat->hash, 0, |
493762fc SR |
655 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
656 | } | |
bac429f0 | 657 | |
cafb168a | 658 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
659 | { |
660 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
661 | int functions; |
662 | int pages; | |
493762fc | 663 | int i; |
bac429f0 | 664 | |
493762fc | 665 | /* If we already allocated, do nothing */ |
cafb168a | 666 | if (stat->pages) |
493762fc | 667 | return 0; |
bac429f0 | 668 | |
cafb168a SR |
669 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
670 | if (!stat->pages) | |
493762fc | 671 | return -ENOMEM; |
bac429f0 | 672 | |
318e0a73 SR |
673 | #ifdef CONFIG_DYNAMIC_FTRACE |
674 | functions = ftrace_update_tot_cnt; | |
675 | #else | |
676 | /* | |
677 | * We do not know the number of functions that exist because | |
678 | * dynamic tracing is what counts them. With past experience | |
679 | * we have around 20K functions. That should be more than enough. | |
680 | * It is highly unlikely we will execute every function in | |
681 | * the kernel. | |
682 | */ | |
683 | functions = 20000; | |
684 | #endif | |
685 | ||
cafb168a | 686 | pg = stat->start = stat->pages; |
bac429f0 | 687 | |
318e0a73 SR |
688 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
689 | ||
39e30cd1 | 690 | for (i = 1; i < pages; i++) { |
493762fc | 691 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 692 | if (!pg->next) |
318e0a73 | 693 | goto out_free; |
493762fc SR |
694 | pg = pg->next; |
695 | } | |
696 | ||
697 | return 0; | |
318e0a73 SR |
698 | |
699 | out_free: | |
700 | pg = stat->start; | |
701 | while (pg) { | |
702 | unsigned long tmp = (unsigned long)pg; | |
703 | ||
704 | pg = pg->next; | |
705 | free_page(tmp); | |
706 | } | |
707 | ||
318e0a73 SR |
708 | stat->pages = NULL; |
709 | stat->start = NULL; | |
710 | ||
711 | return -ENOMEM; | |
bac429f0 SR |
712 | } |
713 | ||
cafb168a | 714 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 715 | { |
cafb168a | 716 | struct ftrace_profile_stat *stat; |
493762fc | 717 | int size; |
bac429f0 | 718 | |
cafb168a SR |
719 | stat = &per_cpu(ftrace_profile_stats, cpu); |
720 | ||
721 | if (stat->hash) { | |
493762fc | 722 | /* If the profile is already created, simply reset it */ |
cafb168a | 723 | ftrace_profile_reset(stat); |
493762fc SR |
724 | return 0; |
725 | } | |
bac429f0 | 726 | |
493762fc SR |
727 | /* |
728 | * We are profiling all functions, but usually only a few thousand | |
729 | * functions are hit. We'll make a hash of 1024 items. | |
730 | */ | |
731 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 732 | |
cafb168a | 733 | stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
493762fc | 734 | |
cafb168a | 735 | if (!stat->hash) |
493762fc SR |
736 | return -ENOMEM; |
737 | ||
318e0a73 | 738 | /* Preallocate the function profiling pages */ |
cafb168a SR |
739 | if (ftrace_profile_pages_init(stat) < 0) { |
740 | kfree(stat->hash); | |
741 | stat->hash = NULL; | |
493762fc SR |
742 | return -ENOMEM; |
743 | } | |
744 | ||
745 | return 0; | |
bac429f0 SR |
746 | } |
747 | ||
cafb168a SR |
748 | static int ftrace_profile_init(void) |
749 | { | |
750 | int cpu; | |
751 | int ret = 0; | |
752 | ||
c4602c1c | 753 | for_each_possible_cpu(cpu) { |
cafb168a SR |
754 | ret = ftrace_profile_init_cpu(cpu); |
755 | if (ret) | |
756 | break; | |
757 | } | |
758 | ||
759 | return ret; | |
760 | } | |
761 | ||
493762fc | 762 | /* interrupts must be disabled */ |
cafb168a SR |
763 | static struct ftrace_profile * |
764 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 765 | { |
493762fc | 766 | struct ftrace_profile *rec; |
bac429f0 | 767 | struct hlist_head *hhd; |
bac429f0 SR |
768 | unsigned long key; |
769 | ||
20079ebe | 770 | key = hash_long(ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 771 | hhd = &stat->hash[key]; |
bac429f0 SR |
772 | |
773 | if (hlist_empty(hhd)) | |
774 | return NULL; | |
775 | ||
1bb539ca | 776 | hlist_for_each_entry_rcu_notrace(rec, hhd, node) { |
bac429f0 | 777 | if (rec->ip == ip) |
493762fc SR |
778 | return rec; |
779 | } | |
780 | ||
781 | return NULL; | |
782 | } | |
783 | ||
cafb168a SR |
784 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
785 | struct ftrace_profile *rec) | |
493762fc SR |
786 | { |
787 | unsigned long key; | |
788 | ||
20079ebe | 789 | key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 790 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
791 | } |
792 | ||
318e0a73 SR |
793 | /* |
794 | * The memory is already allocated, this simply finds a new record to use. | |
795 | */ | |
493762fc | 796 | static struct ftrace_profile * |
318e0a73 | 797 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
798 | { |
799 | struct ftrace_profile *rec = NULL; | |
800 | ||
318e0a73 | 801 | /* prevent recursion (from NMIs) */ |
cafb168a | 802 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
803 | goto out; |
804 | ||
493762fc | 805 | /* |
318e0a73 SR |
806 | * Try to find the function again since an NMI |
807 | * could have added it | |
493762fc | 808 | */ |
cafb168a | 809 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 810 | if (rec) |
cafb168a | 811 | goto out; |
493762fc | 812 | |
cafb168a SR |
813 | if (stat->pages->index == PROFILES_PER_PAGE) { |
814 | if (!stat->pages->next) | |
815 | goto out; | |
816 | stat->pages = stat->pages->next; | |
bac429f0 | 817 | } |
493762fc | 818 | |
cafb168a | 819 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 820 | rec->ip = ip; |
cafb168a | 821 | ftrace_add_profile(stat, rec); |
493762fc | 822 | |
bac429f0 | 823 | out: |
cafb168a | 824 | atomic_dec(&stat->disabled); |
bac429f0 SR |
825 | |
826 | return rec; | |
827 | } | |
828 | ||
829 | static void | |
2f5f6ad9 | 830 | function_profile_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 831 | struct ftrace_ops *ops, struct pt_regs *regs) |
bac429f0 | 832 | { |
cafb168a | 833 | struct ftrace_profile_stat *stat; |
493762fc | 834 | struct ftrace_profile *rec; |
bac429f0 SR |
835 | unsigned long flags; |
836 | ||
837 | if (!ftrace_profile_enabled) | |
838 | return; | |
839 | ||
840 | local_irq_save(flags); | |
cafb168a | 841 | |
bdffd893 | 842 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 843 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
844 | goto out; |
845 | ||
846 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 847 | if (!rec) { |
318e0a73 | 848 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
849 | if (!rec) |
850 | goto out; | |
851 | } | |
bac429f0 SR |
852 | |
853 | rec->counter++; | |
854 | out: | |
855 | local_irq_restore(flags); | |
856 | } | |
857 | ||
0706f1c4 SR |
858 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
859 | static int profile_graph_entry(struct ftrace_graph_ent *trace) | |
860 | { | |
a1e2e31d | 861 | function_profile_call(trace->func, 0, NULL, NULL); |
0706f1c4 SR |
862 | return 1; |
863 | } | |
864 | ||
865 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
866 | { | |
cafb168a | 867 | struct ftrace_profile_stat *stat; |
a2a16d6a | 868 | unsigned long long calltime; |
0706f1c4 | 869 | struct ftrace_profile *rec; |
cafb168a | 870 | unsigned long flags; |
0706f1c4 SR |
871 | |
872 | local_irq_save(flags); | |
bdffd893 | 873 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 874 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
875 | goto out; |
876 | ||
37e44bc5 SR |
877 | /* If the calltime was zero'd ignore it */ |
878 | if (!trace->calltime) | |
879 | goto out; | |
880 | ||
a2a16d6a SR |
881 | calltime = trace->rettime - trace->calltime; |
882 | ||
883 | if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) { | |
884 | int index; | |
885 | ||
886 | index = trace->depth; | |
887 | ||
888 | /* Append this call time to the parent time to subtract */ | |
889 | if (index) | |
890 | current->ret_stack[index - 1].subtime += calltime; | |
891 | ||
892 | if (current->ret_stack[index].subtime < calltime) | |
893 | calltime -= current->ret_stack[index].subtime; | |
894 | else | |
895 | calltime = 0; | |
896 | } | |
897 | ||
cafb168a | 898 | rec = ftrace_find_profiled_func(stat, trace->func); |
e330b3bc | 899 | if (rec) { |
a2a16d6a | 900 | rec->time += calltime; |
e330b3bc CD |
901 | rec->time_squared += calltime * calltime; |
902 | } | |
a2a16d6a | 903 | |
cafb168a | 904 | out: |
0706f1c4 SR |
905 | local_irq_restore(flags); |
906 | } | |
907 | ||
908 | static int register_ftrace_profiler(void) | |
909 | { | |
910 | return register_ftrace_graph(&profile_graph_return, | |
911 | &profile_graph_entry); | |
912 | } | |
913 | ||
914 | static void unregister_ftrace_profiler(void) | |
915 | { | |
916 | unregister_ftrace_graph(); | |
917 | } | |
918 | #else | |
bd38c0e6 | 919 | static struct ftrace_ops ftrace_profile_ops __read_mostly = { |
fb9fb015 | 920 | .func = function_profile_call, |
f04f24fb | 921 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, |
33b7f99c | 922 | INIT_OPS_HASH(ftrace_profile_ops) |
bac429f0 SR |
923 | }; |
924 | ||
0706f1c4 SR |
925 | static int register_ftrace_profiler(void) |
926 | { | |
927 | return register_ftrace_function(&ftrace_profile_ops); | |
928 | } | |
929 | ||
930 | static void unregister_ftrace_profiler(void) | |
931 | { | |
932 | unregister_ftrace_function(&ftrace_profile_ops); | |
933 | } | |
934 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
935 | ||
bac429f0 SR |
936 | static ssize_t |
937 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
938 | size_t cnt, loff_t *ppos) | |
939 | { | |
940 | unsigned long val; | |
bac429f0 SR |
941 | int ret; |
942 | ||
22fe9b54 PH |
943 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
944 | if (ret) | |
bac429f0 SR |
945 | return ret; |
946 | ||
947 | val = !!val; | |
948 | ||
949 | mutex_lock(&ftrace_profile_lock); | |
950 | if (ftrace_profile_enabled ^ val) { | |
951 | if (val) { | |
493762fc SR |
952 | ret = ftrace_profile_init(); |
953 | if (ret < 0) { | |
954 | cnt = ret; | |
955 | goto out; | |
956 | } | |
957 | ||
0706f1c4 SR |
958 | ret = register_ftrace_profiler(); |
959 | if (ret < 0) { | |
960 | cnt = ret; | |
961 | goto out; | |
962 | } | |
bac429f0 SR |
963 | ftrace_profile_enabled = 1; |
964 | } else { | |
965 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
966 | /* |
967 | * unregister_ftrace_profiler calls stop_machine | |
968 | * so this acts like an synchronize_sched. | |
969 | */ | |
0706f1c4 | 970 | unregister_ftrace_profiler(); |
bac429f0 SR |
971 | } |
972 | } | |
493762fc | 973 | out: |
bac429f0 SR |
974 | mutex_unlock(&ftrace_profile_lock); |
975 | ||
cf8517cf | 976 | *ppos += cnt; |
bac429f0 SR |
977 | |
978 | return cnt; | |
979 | } | |
980 | ||
493762fc SR |
981 | static ssize_t |
982 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
983 | size_t cnt, loff_t *ppos) | |
984 | { | |
fb9fb015 | 985 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
986 | int r; |
987 | ||
988 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
989 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
990 | } | |
991 | ||
bac429f0 SR |
992 | static const struct file_operations ftrace_profile_fops = { |
993 | .open = tracing_open_generic, | |
994 | .read = ftrace_profile_read, | |
995 | .write = ftrace_profile_write, | |
6038f373 | 996 | .llseek = default_llseek, |
bac429f0 SR |
997 | }; |
998 | ||
cafb168a SR |
999 | /* used to initialize the real stat files */ |
1000 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
1001 | .name = "functions", |
1002 | .stat_start = function_stat_start, | |
1003 | .stat_next = function_stat_next, | |
1004 | .stat_cmp = function_stat_cmp, | |
1005 | .stat_headers = function_stat_headers, | |
1006 | .stat_show = function_stat_show | |
cafb168a SR |
1007 | }; |
1008 | ||
6ab5d668 | 1009 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 | 1010 | { |
cafb168a | 1011 | struct ftrace_profile_stat *stat; |
bac429f0 | 1012 | struct dentry *entry; |
cafb168a | 1013 | char *name; |
bac429f0 | 1014 | int ret; |
cafb168a SR |
1015 | int cpu; |
1016 | ||
1017 | for_each_possible_cpu(cpu) { | |
1018 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
1019 | ||
1020 | /* allocate enough for function name + cpu number */ | |
1021 | name = kmalloc(32, GFP_KERNEL); | |
1022 | if (!name) { | |
1023 | /* | |
1024 | * The files created are permanent, if something happens | |
1025 | * we still do not free memory. | |
1026 | */ | |
cafb168a SR |
1027 | WARN(1, |
1028 | "Could not allocate stat file for cpu %d\n", | |
1029 | cpu); | |
1030 | return; | |
1031 | } | |
1032 | stat->stat = function_stats; | |
1033 | snprintf(name, 32, "function%d", cpu); | |
1034 | stat->stat.name = name; | |
1035 | ret = register_stat_tracer(&stat->stat); | |
1036 | if (ret) { | |
1037 | WARN(1, | |
1038 | "Could not register function stat for cpu %d\n", | |
1039 | cpu); | |
1040 | kfree(name); | |
1041 | return; | |
1042 | } | |
bac429f0 SR |
1043 | } |
1044 | ||
1045 | entry = debugfs_create_file("function_profile_enabled", 0644, | |
1046 | d_tracer, NULL, &ftrace_profile_fops); | |
1047 | if (!entry) | |
1048 | pr_warning("Could not create debugfs " | |
1049 | "'function_profile_enabled' entry\n"); | |
1050 | } | |
1051 | ||
bac429f0 | 1052 | #else /* CONFIG_FUNCTION_PROFILER */ |
6ab5d668 | 1053 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 SR |
1054 | { |
1055 | } | |
bac429f0 SR |
1056 | #endif /* CONFIG_FUNCTION_PROFILER */ |
1057 | ||
493762fc SR |
1058 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; |
1059 | ||
1060 | #ifdef CONFIG_DYNAMIC_FTRACE | |
1061 | ||
79922b80 SRRH |
1062 | static struct ftrace_ops *removed_ops; |
1063 | ||
e1effa01 SRRH |
1064 | /* |
1065 | * Set when doing a global update, like enabling all recs or disabling them. | |
1066 | * It is not set when just updating a single ftrace_ops. | |
1067 | */ | |
1068 | static bool update_all_ops; | |
1069 | ||
493762fc SR |
1070 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
1071 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
1072 | #endif | |
1073 | ||
1074 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; | |
1075 | ||
1076 | struct ftrace_func_probe { | |
1077 | struct hlist_node node; | |
1078 | struct ftrace_probe_ops *ops; | |
1079 | unsigned long flags; | |
1080 | unsigned long ip; | |
1081 | void *data; | |
7818b388 | 1082 | struct list_head free_list; |
493762fc SR |
1083 | }; |
1084 | ||
b448c4e3 SR |
1085 | struct ftrace_func_entry { |
1086 | struct hlist_node hlist; | |
1087 | unsigned long ip; | |
1088 | }; | |
1089 | ||
1090 | struct ftrace_hash { | |
1091 | unsigned long size_bits; | |
1092 | struct hlist_head *buckets; | |
1093 | unsigned long count; | |
07fd5515 | 1094 | struct rcu_head rcu; |
b448c4e3 SR |
1095 | }; |
1096 | ||
33dc9b12 SR |
1097 | /* |
1098 | * We make these constant because no one should touch them, | |
1099 | * but they are used as the default "empty hash", to avoid allocating | |
1100 | * it all the time. These are in a read only section such that if | |
1101 | * anyone does try to modify it, it will cause an exception. | |
1102 | */ | |
1103 | static const struct hlist_head empty_buckets[1]; | |
1104 | static const struct ftrace_hash empty_hash = { | |
1105 | .buckets = (struct hlist_head *)empty_buckets, | |
1cf41dd7 | 1106 | }; |
33dc9b12 | 1107 | #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash) |
493762fc | 1108 | |
2b499381 | 1109 | static struct ftrace_ops global_ops = { |
33b7f99c SRRH |
1110 | .func = ftrace_stub, |
1111 | .local_hash.notrace_hash = EMPTY_HASH, | |
1112 | .local_hash.filter_hash = EMPTY_HASH, | |
1113 | INIT_OPS_HASH(global_ops) | |
1114 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | | |
1115 | FTRACE_OPS_FL_INITIALIZED, | |
f45948e8 SR |
1116 | }; |
1117 | ||
493762fc SR |
1118 | struct ftrace_page { |
1119 | struct ftrace_page *next; | |
a7900875 | 1120 | struct dyn_ftrace *records; |
493762fc | 1121 | int index; |
a7900875 | 1122 | int size; |
493762fc SR |
1123 | }; |
1124 | ||
a7900875 SR |
1125 | #define ENTRY_SIZE sizeof(struct dyn_ftrace) |
1126 | #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE) | |
493762fc SR |
1127 | |
1128 | /* estimate from running different kernels */ | |
1129 | #define NR_TO_INIT 10000 | |
1130 | ||
1131 | static struct ftrace_page *ftrace_pages_start; | |
1132 | static struct ftrace_page *ftrace_pages; | |
1133 | ||
68f40969 | 1134 | static bool __always_inline ftrace_hash_empty(struct ftrace_hash *hash) |
06a51d93 SR |
1135 | { |
1136 | return !hash || !hash->count; | |
1137 | } | |
1138 | ||
b448c4e3 SR |
1139 | static struct ftrace_func_entry * |
1140 | ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
1141 | { | |
1142 | unsigned long key; | |
1143 | struct ftrace_func_entry *entry; | |
1144 | struct hlist_head *hhd; | |
b448c4e3 | 1145 | |
06a51d93 | 1146 | if (ftrace_hash_empty(hash)) |
b448c4e3 SR |
1147 | return NULL; |
1148 | ||
1149 | if (hash->size_bits > 0) | |
1150 | key = hash_long(ip, hash->size_bits); | |
1151 | else | |
1152 | key = 0; | |
1153 | ||
1154 | hhd = &hash->buckets[key]; | |
1155 | ||
1bb539ca | 1156 | hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) { |
b448c4e3 SR |
1157 | if (entry->ip == ip) |
1158 | return entry; | |
1159 | } | |
1160 | return NULL; | |
1161 | } | |
1162 | ||
33dc9b12 SR |
1163 | static void __add_hash_entry(struct ftrace_hash *hash, |
1164 | struct ftrace_func_entry *entry) | |
b448c4e3 | 1165 | { |
b448c4e3 SR |
1166 | struct hlist_head *hhd; |
1167 | unsigned long key; | |
1168 | ||
b448c4e3 | 1169 | if (hash->size_bits) |
33dc9b12 | 1170 | key = hash_long(entry->ip, hash->size_bits); |
b448c4e3 SR |
1171 | else |
1172 | key = 0; | |
1173 | ||
b448c4e3 SR |
1174 | hhd = &hash->buckets[key]; |
1175 | hlist_add_head(&entry->hlist, hhd); | |
1176 | hash->count++; | |
33dc9b12 SR |
1177 | } |
1178 | ||
1179 | static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip) | |
1180 | { | |
1181 | struct ftrace_func_entry *entry; | |
1182 | ||
1183 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1184 | if (!entry) | |
1185 | return -ENOMEM; | |
1186 | ||
1187 | entry->ip = ip; | |
1188 | __add_hash_entry(hash, entry); | |
b448c4e3 SR |
1189 | |
1190 | return 0; | |
1191 | } | |
1192 | ||
1193 | static void | |
33dc9b12 | 1194 | free_hash_entry(struct ftrace_hash *hash, |
b448c4e3 SR |
1195 | struct ftrace_func_entry *entry) |
1196 | { | |
1197 | hlist_del(&entry->hlist); | |
1198 | kfree(entry); | |
1199 | hash->count--; | |
1200 | } | |
1201 | ||
33dc9b12 SR |
1202 | static void |
1203 | remove_hash_entry(struct ftrace_hash *hash, | |
1204 | struct ftrace_func_entry *entry) | |
1205 | { | |
1206 | hlist_del(&entry->hlist); | |
1207 | hash->count--; | |
1208 | } | |
1209 | ||
b448c4e3 SR |
1210 | static void ftrace_hash_clear(struct ftrace_hash *hash) |
1211 | { | |
1212 | struct hlist_head *hhd; | |
b67bfe0d | 1213 | struct hlist_node *tn; |
b448c4e3 SR |
1214 | struct ftrace_func_entry *entry; |
1215 | int size = 1 << hash->size_bits; | |
1216 | int i; | |
1217 | ||
33dc9b12 SR |
1218 | if (!hash->count) |
1219 | return; | |
1220 | ||
b448c4e3 SR |
1221 | for (i = 0; i < size; i++) { |
1222 | hhd = &hash->buckets[i]; | |
b67bfe0d | 1223 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) |
33dc9b12 | 1224 | free_hash_entry(hash, entry); |
b448c4e3 SR |
1225 | } |
1226 | FTRACE_WARN_ON(hash->count); | |
1227 | } | |
1228 | ||
33dc9b12 SR |
1229 | static void free_ftrace_hash(struct ftrace_hash *hash) |
1230 | { | |
1231 | if (!hash || hash == EMPTY_HASH) | |
1232 | return; | |
1233 | ftrace_hash_clear(hash); | |
1234 | kfree(hash->buckets); | |
1235 | kfree(hash); | |
1236 | } | |
1237 | ||
07fd5515 SR |
1238 | static void __free_ftrace_hash_rcu(struct rcu_head *rcu) |
1239 | { | |
1240 | struct ftrace_hash *hash; | |
1241 | ||
1242 | hash = container_of(rcu, struct ftrace_hash, rcu); | |
1243 | free_ftrace_hash(hash); | |
1244 | } | |
1245 | ||
1246 | static void free_ftrace_hash_rcu(struct ftrace_hash *hash) | |
1247 | { | |
1248 | if (!hash || hash == EMPTY_HASH) | |
1249 | return; | |
1250 | call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu); | |
1251 | } | |
1252 | ||
5500fa51 JO |
1253 | void ftrace_free_filter(struct ftrace_ops *ops) |
1254 | { | |
f04f24fb | 1255 | ftrace_ops_init(ops); |
33b7f99c SRRH |
1256 | free_ftrace_hash(ops->func_hash->filter_hash); |
1257 | free_ftrace_hash(ops->func_hash->notrace_hash); | |
5500fa51 JO |
1258 | } |
1259 | ||
33dc9b12 SR |
1260 | static struct ftrace_hash *alloc_ftrace_hash(int size_bits) |
1261 | { | |
1262 | struct ftrace_hash *hash; | |
1263 | int size; | |
1264 | ||
1265 | hash = kzalloc(sizeof(*hash), GFP_KERNEL); | |
1266 | if (!hash) | |
1267 | return NULL; | |
1268 | ||
1269 | size = 1 << size_bits; | |
47b0edcb | 1270 | hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL); |
33dc9b12 SR |
1271 | |
1272 | if (!hash->buckets) { | |
1273 | kfree(hash); | |
1274 | return NULL; | |
1275 | } | |
1276 | ||
1277 | hash->size_bits = size_bits; | |
1278 | ||
1279 | return hash; | |
1280 | } | |
1281 | ||
1282 | static struct ftrace_hash * | |
1283 | alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) | |
1284 | { | |
1285 | struct ftrace_func_entry *entry; | |
1286 | struct ftrace_hash *new_hash; | |
33dc9b12 SR |
1287 | int size; |
1288 | int ret; | |
1289 | int i; | |
1290 | ||
1291 | new_hash = alloc_ftrace_hash(size_bits); | |
1292 | if (!new_hash) | |
1293 | return NULL; | |
1294 | ||
1295 | /* Empty hash? */ | |
06a51d93 | 1296 | if (ftrace_hash_empty(hash)) |
33dc9b12 SR |
1297 | return new_hash; |
1298 | ||
1299 | size = 1 << hash->size_bits; | |
1300 | for (i = 0; i < size; i++) { | |
b67bfe0d | 1301 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { |
33dc9b12 SR |
1302 | ret = add_hash_entry(new_hash, entry->ip); |
1303 | if (ret < 0) | |
1304 | goto free_hash; | |
1305 | } | |
1306 | } | |
1307 | ||
1308 | FTRACE_WARN_ON(new_hash->count != hash->count); | |
1309 | ||
1310 | return new_hash; | |
1311 | ||
1312 | free_hash: | |
1313 | free_ftrace_hash(new_hash); | |
1314 | return NULL; | |
1315 | } | |
1316 | ||
41fb61c2 | 1317 | static void |
84261912 | 1318 | ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash); |
41fb61c2 | 1319 | static void |
84261912 | 1320 | ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash); |
41fb61c2 | 1321 | |
33dc9b12 | 1322 | static int |
41fb61c2 SR |
1323 | ftrace_hash_move(struct ftrace_ops *ops, int enable, |
1324 | struct ftrace_hash **dst, struct ftrace_hash *src) | |
33dc9b12 SR |
1325 | { |
1326 | struct ftrace_func_entry *entry; | |
b67bfe0d | 1327 | struct hlist_node *tn; |
33dc9b12 | 1328 | struct hlist_head *hhd; |
07fd5515 | 1329 | struct ftrace_hash *new_hash; |
33dc9b12 SR |
1330 | int size = src->count; |
1331 | int bits = 0; | |
1332 | int i; | |
1333 | ||
1334 | /* | |
1335 | * If the new source is empty, just free dst and assign it | |
1336 | * the empty_hash. | |
1337 | */ | |
1338 | if (!src->count) { | |
5c27c775 MH |
1339 | new_hash = EMPTY_HASH; |
1340 | goto update; | |
33dc9b12 SR |
1341 | } |
1342 | ||
33dc9b12 SR |
1343 | /* |
1344 | * Make the hash size about 1/2 the # found | |
1345 | */ | |
1346 | for (size /= 2; size; size >>= 1) | |
1347 | bits++; | |
1348 | ||
1349 | /* Don't allocate too much */ | |
1350 | if (bits > FTRACE_HASH_MAX_BITS) | |
1351 | bits = FTRACE_HASH_MAX_BITS; | |
1352 | ||
07fd5515 SR |
1353 | new_hash = alloc_ftrace_hash(bits); |
1354 | if (!new_hash) | |
5c27c775 | 1355 | return -ENOMEM; |
33dc9b12 SR |
1356 | |
1357 | size = 1 << src->size_bits; | |
1358 | for (i = 0; i < size; i++) { | |
1359 | hhd = &src->buckets[i]; | |
b67bfe0d | 1360 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) { |
33dc9b12 | 1361 | remove_hash_entry(src, entry); |
07fd5515 | 1362 | __add_hash_entry(new_hash, entry); |
33dc9b12 SR |
1363 | } |
1364 | } | |
1365 | ||
5c27c775 MH |
1366 | update: |
1367 | /* | |
1368 | * Remove the current set, update the hash and add | |
1369 | * them back. | |
1370 | */ | |
84261912 | 1371 | ftrace_hash_rec_disable_modify(ops, enable); |
5c27c775 | 1372 | |
07fd5515 | 1373 | rcu_assign_pointer(*dst, new_hash); |
07fd5515 | 1374 | |
84261912 | 1375 | ftrace_hash_rec_enable_modify(ops, enable); |
41fb61c2 | 1376 | |
5c27c775 | 1377 | return 0; |
33dc9b12 SR |
1378 | } |
1379 | ||
fef5aeee SRRH |
1380 | static bool hash_contains_ip(unsigned long ip, |
1381 | struct ftrace_ops_hash *hash) | |
1382 | { | |
1383 | /* | |
1384 | * The function record is a match if it exists in the filter | |
1385 | * hash and not in the notrace hash. Note, an emty hash is | |
1386 | * considered a match for the filter hash, but an empty | |
1387 | * notrace hash is considered not in the notrace hash. | |
1388 | */ | |
1389 | return (ftrace_hash_empty(hash->filter_hash) || | |
1390 | ftrace_lookup_ip(hash->filter_hash, ip)) && | |
1391 | (ftrace_hash_empty(hash->notrace_hash) || | |
1392 | !ftrace_lookup_ip(hash->notrace_hash, ip)); | |
1393 | } | |
1394 | ||
b848914c SR |
1395 | /* |
1396 | * Test the hashes for this ops to see if we want to call | |
1397 | * the ops->func or not. | |
1398 | * | |
1399 | * It's a match if the ip is in the ops->filter_hash or | |
1400 | * the filter_hash does not exist or is empty, | |
1401 | * AND | |
1402 | * the ip is not in the ops->notrace_hash. | |
cdbe61bf SR |
1403 | * |
1404 | * This needs to be called with preemption disabled as | |
1405 | * the hashes are freed with call_rcu_sched(). | |
b848914c SR |
1406 | */ |
1407 | static int | |
195a8afc | 1408 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
b848914c | 1409 | { |
fef5aeee | 1410 | struct ftrace_ops_hash hash; |
b848914c SR |
1411 | int ret; |
1412 | ||
195a8afc SRRH |
1413 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
1414 | /* | |
1415 | * There's a small race when adding ops that the ftrace handler | |
1416 | * that wants regs, may be called without them. We can not | |
1417 | * allow that handler to be called if regs is NULL. | |
1418 | */ | |
1419 | if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS)) | |
1420 | return 0; | |
1421 | #endif | |
1422 | ||
fef5aeee SRRH |
1423 | hash.filter_hash = rcu_dereference_raw_notrace(ops->func_hash->filter_hash); |
1424 | hash.notrace_hash = rcu_dereference_raw_notrace(ops->func_hash->notrace_hash); | |
b848914c | 1425 | |
fef5aeee | 1426 | if (hash_contains_ip(ip, &hash)) |
b848914c SR |
1427 | ret = 1; |
1428 | else | |
1429 | ret = 0; | |
b848914c SR |
1430 | |
1431 | return ret; | |
1432 | } | |
1433 | ||
493762fc SR |
1434 | /* |
1435 | * This is a double for. Do not use 'break' to break out of the loop, | |
1436 | * you must use a goto. | |
1437 | */ | |
1438 | #define do_for_each_ftrace_rec(pg, rec) \ | |
1439 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
1440 | int _____i; \ | |
1441 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
1442 | rec = &pg->records[_____i]; | |
1443 | ||
1444 | #define while_for_each_ftrace_rec() \ | |
1445 | } \ | |
1446 | } | |
1447 | ||
5855fead SR |
1448 | |
1449 | static int ftrace_cmp_recs(const void *a, const void *b) | |
1450 | { | |
a650e02a SR |
1451 | const struct dyn_ftrace *key = a; |
1452 | const struct dyn_ftrace *rec = b; | |
5855fead | 1453 | |
a650e02a | 1454 | if (key->flags < rec->ip) |
5855fead | 1455 | return -1; |
a650e02a SR |
1456 | if (key->ip >= rec->ip + MCOUNT_INSN_SIZE) |
1457 | return 1; | |
5855fead SR |
1458 | return 0; |
1459 | } | |
1460 | ||
f0cf973a | 1461 | static unsigned long ftrace_location_range(unsigned long start, unsigned long end) |
c88fd863 SR |
1462 | { |
1463 | struct ftrace_page *pg; | |
1464 | struct dyn_ftrace *rec; | |
5855fead | 1465 | struct dyn_ftrace key; |
c88fd863 | 1466 | |
a650e02a SR |
1467 | key.ip = start; |
1468 | key.flags = end; /* overload flags, as it is unsigned long */ | |
5855fead SR |
1469 | |
1470 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
a650e02a SR |
1471 | if (end < pg->records[0].ip || |
1472 | start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) | |
9644302e | 1473 | continue; |
5855fead SR |
1474 | rec = bsearch(&key, pg->records, pg->index, |
1475 | sizeof(struct dyn_ftrace), | |
1476 | ftrace_cmp_recs); | |
1477 | if (rec) | |
f0cf973a | 1478 | return rec->ip; |
5855fead | 1479 | } |
c88fd863 SR |
1480 | |
1481 | return 0; | |
1482 | } | |
1483 | ||
a650e02a SR |
1484 | /** |
1485 | * ftrace_location - return true if the ip giving is a traced location | |
1486 | * @ip: the instruction pointer to check | |
1487 | * | |
f0cf973a | 1488 | * Returns rec->ip if @ip given is a pointer to a ftrace location. |
a650e02a SR |
1489 | * That is, the instruction that is either a NOP or call to |
1490 | * the function tracer. It checks the ftrace internal tables to | |
1491 | * determine if the address belongs or not. | |
1492 | */ | |
f0cf973a | 1493 | unsigned long ftrace_location(unsigned long ip) |
a650e02a SR |
1494 | { |
1495 | return ftrace_location_range(ip, ip); | |
1496 | } | |
1497 | ||
1498 | /** | |
1499 | * ftrace_text_reserved - return true if range contains an ftrace location | |
1500 | * @start: start of range to search | |
1501 | * @end: end of range to search (inclusive). @end points to the last byte to check. | |
1502 | * | |
1503 | * Returns 1 if @start and @end contains a ftrace location. | |
1504 | * That is, the instruction that is either a NOP or call to | |
1505 | * the function tracer. It checks the ftrace internal tables to | |
1506 | * determine if the address belongs or not. | |
1507 | */ | |
d88471cb | 1508 | int ftrace_text_reserved(const void *start, const void *end) |
a650e02a | 1509 | { |
f0cf973a SR |
1510 | unsigned long ret; |
1511 | ||
1512 | ret = ftrace_location_range((unsigned long)start, | |
1513 | (unsigned long)end); | |
1514 | ||
1515 | return (int)!!ret; | |
a650e02a SR |
1516 | } |
1517 | ||
4fbb48cb SRRH |
1518 | /* Test if ops registered to this rec needs regs */ |
1519 | static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec) | |
1520 | { | |
1521 | struct ftrace_ops *ops; | |
1522 | bool keep_regs = false; | |
1523 | ||
1524 | for (ops = ftrace_ops_list; | |
1525 | ops != &ftrace_list_end; ops = ops->next) { | |
1526 | /* pass rec in as regs to have non-NULL val */ | |
1527 | if (ftrace_ops_test(ops, rec->ip, rec)) { | |
1528 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1529 | keep_regs = true; | |
1530 | break; | |
1531 | } | |
1532 | } | |
1533 | } | |
1534 | ||
1535 | return keep_regs; | |
1536 | } | |
1537 | ||
ed926f9b SR |
1538 | static void __ftrace_hash_rec_update(struct ftrace_ops *ops, |
1539 | int filter_hash, | |
1540 | bool inc) | |
1541 | { | |
1542 | struct ftrace_hash *hash; | |
1543 | struct ftrace_hash *other_hash; | |
1544 | struct ftrace_page *pg; | |
1545 | struct dyn_ftrace *rec; | |
1546 | int count = 0; | |
1547 | int all = 0; | |
1548 | ||
1549 | /* Only update if the ops has been registered */ | |
1550 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
1551 | return; | |
1552 | ||
1553 | /* | |
1554 | * In the filter_hash case: | |
1555 | * If the count is zero, we update all records. | |
1556 | * Otherwise we just update the items in the hash. | |
1557 | * | |
1558 | * In the notrace_hash case: | |
1559 | * We enable the update in the hash. | |
1560 | * As disabling notrace means enabling the tracing, | |
1561 | * and enabling notrace means disabling, the inc variable | |
1562 | * gets inversed. | |
1563 | */ | |
1564 | if (filter_hash) { | |
33b7f99c SRRH |
1565 | hash = ops->func_hash->filter_hash; |
1566 | other_hash = ops->func_hash->notrace_hash; | |
06a51d93 | 1567 | if (ftrace_hash_empty(hash)) |
ed926f9b SR |
1568 | all = 1; |
1569 | } else { | |
1570 | inc = !inc; | |
33b7f99c SRRH |
1571 | hash = ops->func_hash->notrace_hash; |
1572 | other_hash = ops->func_hash->filter_hash; | |
ed926f9b SR |
1573 | /* |
1574 | * If the notrace hash has no items, | |
1575 | * then there's nothing to do. | |
1576 | */ | |
06a51d93 | 1577 | if (ftrace_hash_empty(hash)) |
ed926f9b SR |
1578 | return; |
1579 | } | |
1580 | ||
1581 | do_for_each_ftrace_rec(pg, rec) { | |
1582 | int in_other_hash = 0; | |
1583 | int in_hash = 0; | |
1584 | int match = 0; | |
1585 | ||
1586 | if (all) { | |
1587 | /* | |
1588 | * Only the filter_hash affects all records. | |
1589 | * Update if the record is not in the notrace hash. | |
1590 | */ | |
b848914c | 1591 | if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) |
ed926f9b SR |
1592 | match = 1; |
1593 | } else { | |
06a51d93 SR |
1594 | in_hash = !!ftrace_lookup_ip(hash, rec->ip); |
1595 | in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip); | |
ed926f9b SR |
1596 | |
1597 | /* | |
19eab4a4 SRRH |
1598 | * If filter_hash is set, we want to match all functions |
1599 | * that are in the hash but not in the other hash. | |
ed926f9b | 1600 | * |
19eab4a4 SRRH |
1601 | * If filter_hash is not set, then we are decrementing. |
1602 | * That means we match anything that is in the hash | |
1603 | * and also in the other_hash. That is, we need to turn | |
1604 | * off functions in the other hash because they are disabled | |
1605 | * by this hash. | |
ed926f9b SR |
1606 | */ |
1607 | if (filter_hash && in_hash && !in_other_hash) | |
1608 | match = 1; | |
1609 | else if (!filter_hash && in_hash && | |
06a51d93 | 1610 | (in_other_hash || ftrace_hash_empty(other_hash))) |
ed926f9b SR |
1611 | match = 1; |
1612 | } | |
1613 | if (!match) | |
1614 | continue; | |
1615 | ||
1616 | if (inc) { | |
1617 | rec->flags++; | |
0376bde1 | 1618 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX)) |
ed926f9b | 1619 | return; |
79922b80 SRRH |
1620 | |
1621 | /* | |
1622 | * If there's only a single callback registered to a | |
1623 | * function, and the ops has a trampoline registered | |
1624 | * for it, then we can call it directly. | |
1625 | */ | |
fef5aeee | 1626 | if (ftrace_rec_count(rec) == 1 && ops->trampoline) |
79922b80 | 1627 | rec->flags |= FTRACE_FL_TRAMP; |
fef5aeee | 1628 | else |
79922b80 SRRH |
1629 | /* |
1630 | * If we are adding another function callback | |
1631 | * to this function, and the previous had a | |
bce0b6c5 SRRH |
1632 | * custom trampoline in use, then we need to go |
1633 | * back to the default trampoline. | |
79922b80 | 1634 | */ |
fef5aeee | 1635 | rec->flags &= ~FTRACE_FL_TRAMP; |
79922b80 | 1636 | |
08f6fba5 SR |
1637 | /* |
1638 | * If any ops wants regs saved for this function | |
1639 | * then all ops will get saved regs. | |
1640 | */ | |
1641 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) | |
1642 | rec->flags |= FTRACE_FL_REGS; | |
ed926f9b | 1643 | } else { |
0376bde1 | 1644 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0)) |
ed926f9b SR |
1645 | return; |
1646 | rec->flags--; | |
79922b80 | 1647 | |
4fbb48cb SRRH |
1648 | /* |
1649 | * If the rec had REGS enabled and the ops that is | |
1650 | * being removed had REGS set, then see if there is | |
1651 | * still any ops for this record that wants regs. | |
1652 | * If not, we can stop recording them. | |
1653 | */ | |
0376bde1 | 1654 | if (ftrace_rec_count(rec) > 0 && |
4fbb48cb SRRH |
1655 | rec->flags & FTRACE_FL_REGS && |
1656 | ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1657 | if (!test_rec_ops_needs_regs(rec)) | |
1658 | rec->flags &= ~FTRACE_FL_REGS; | |
1659 | } | |
79922b80 | 1660 | |
fef5aeee SRRH |
1661 | /* |
1662 | * If the rec had TRAMP enabled, then it needs to | |
1663 | * be cleared. As TRAMP can only be enabled iff | |
1664 | * there is only a single ops attached to it. | |
1665 | * In otherwords, always disable it on decrementing. | |
1666 | * In the future, we may set it if rec count is | |
1667 | * decremented to one, and the ops that is left | |
1668 | * has a trampoline. | |
1669 | */ | |
1670 | rec->flags &= ~FTRACE_FL_TRAMP; | |
1671 | ||
79922b80 SRRH |
1672 | /* |
1673 | * flags will be cleared in ftrace_check_record() | |
1674 | * if rec count is zero. | |
1675 | */ | |
ed926f9b SR |
1676 | } |
1677 | count++; | |
1678 | /* Shortcut, if we handled all records, we are done. */ | |
1679 | if (!all && count == hash->count) | |
1680 | return; | |
1681 | } while_for_each_ftrace_rec(); | |
1682 | } | |
1683 | ||
1684 | static void ftrace_hash_rec_disable(struct ftrace_ops *ops, | |
1685 | int filter_hash) | |
1686 | { | |
1687 | __ftrace_hash_rec_update(ops, filter_hash, 0); | |
1688 | } | |
1689 | ||
1690 | static void ftrace_hash_rec_enable(struct ftrace_ops *ops, | |
1691 | int filter_hash) | |
1692 | { | |
1693 | __ftrace_hash_rec_update(ops, filter_hash, 1); | |
1694 | } | |
1695 | ||
84261912 SRRH |
1696 | static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops, |
1697 | int filter_hash, int inc) | |
1698 | { | |
1699 | struct ftrace_ops *op; | |
1700 | ||
1701 | __ftrace_hash_rec_update(ops, filter_hash, inc); | |
1702 | ||
1703 | if (ops->func_hash != &global_ops.local_hash) | |
1704 | return; | |
1705 | ||
1706 | /* | |
1707 | * If the ops shares the global_ops hash, then we need to update | |
1708 | * all ops that are enabled and use this hash. | |
1709 | */ | |
1710 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1711 | /* Already done */ | |
1712 | if (op == ops) | |
1713 | continue; | |
1714 | if (op->func_hash == &global_ops.local_hash) | |
1715 | __ftrace_hash_rec_update(op, filter_hash, inc); | |
1716 | } while_for_each_ftrace_op(op); | |
1717 | } | |
1718 | ||
1719 | static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, | |
1720 | int filter_hash) | |
1721 | { | |
1722 | ftrace_hash_rec_update_modify(ops, filter_hash, 0); | |
1723 | } | |
1724 | ||
1725 | static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, | |
1726 | int filter_hash) | |
1727 | { | |
1728 | ftrace_hash_rec_update_modify(ops, filter_hash, 1); | |
1729 | } | |
1730 | ||
b17e8a37 SR |
1731 | static void print_ip_ins(const char *fmt, unsigned char *p) |
1732 | { | |
1733 | int i; | |
1734 | ||
1735 | printk(KERN_CONT "%s", fmt); | |
1736 | ||
1737 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
1738 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
1739 | } | |
1740 | ||
4fd3279b SRRH |
1741 | static struct ftrace_ops * |
1742 | ftrace_find_tramp_ops_any(struct dyn_ftrace *rec); | |
1743 | ||
c88fd863 SR |
1744 | /** |
1745 | * ftrace_bug - report and shutdown function tracer | |
1746 | * @failed: The failed type (EFAULT, EINVAL, EPERM) | |
4fd3279b | 1747 | * @rec: The record that failed |
c88fd863 SR |
1748 | * |
1749 | * The arch code that enables or disables the function tracing | |
1750 | * can call ftrace_bug() when it has detected a problem in | |
1751 | * modifying the code. @failed should be one of either: | |
1752 | * EFAULT - if the problem happens on reading the @ip address | |
1753 | * EINVAL - if what is read at @ip is not what was expected | |
1754 | * EPERM - if the problem happens on writting to the @ip address | |
1755 | */ | |
4fd3279b | 1756 | void ftrace_bug(int failed, struct dyn_ftrace *rec) |
b17e8a37 | 1757 | { |
4fd3279b SRRH |
1758 | unsigned long ip = rec ? rec->ip : 0; |
1759 | ||
b17e8a37 SR |
1760 | switch (failed) { |
1761 | case -EFAULT: | |
1762 | FTRACE_WARN_ON_ONCE(1); | |
1763 | pr_info("ftrace faulted on modifying "); | |
1764 | print_ip_sym(ip); | |
1765 | break; | |
1766 | case -EINVAL: | |
1767 | FTRACE_WARN_ON_ONCE(1); | |
1768 | pr_info("ftrace failed to modify "); | |
1769 | print_ip_sym(ip); | |
b17e8a37 | 1770 | print_ip_ins(" actual: ", (unsigned char *)ip); |
4fd3279b | 1771 | pr_cont("\n"); |
b17e8a37 SR |
1772 | break; |
1773 | case -EPERM: | |
1774 | FTRACE_WARN_ON_ONCE(1); | |
1775 | pr_info("ftrace faulted on writing "); | |
1776 | print_ip_sym(ip); | |
1777 | break; | |
1778 | default: | |
1779 | FTRACE_WARN_ON_ONCE(1); | |
1780 | pr_info("ftrace faulted on unknown error "); | |
1781 | print_ip_sym(ip); | |
1782 | } | |
4fd3279b SRRH |
1783 | if (rec) { |
1784 | struct ftrace_ops *ops = NULL; | |
1785 | ||
1786 | pr_info("ftrace record flags: %lx\n", rec->flags); | |
1787 | pr_cont(" (%ld)%s", ftrace_rec_count(rec), | |
1788 | rec->flags & FTRACE_FL_REGS ? " R" : " "); | |
1789 | if (rec->flags & FTRACE_FL_TRAMP_EN) { | |
1790 | ops = ftrace_find_tramp_ops_any(rec); | |
1791 | if (ops) | |
1792 | pr_cont("\ttramp: %pS", | |
1793 | (void *)ops->trampoline); | |
1794 | else | |
1795 | pr_cont("\ttramp: ERROR!"); | |
1796 | ||
1797 | } | |
1798 | ip = ftrace_get_addr_curr(rec); | |
1799 | pr_cont(" expected tramp: %lx\n", ip); | |
1800 | } | |
b17e8a37 SR |
1801 | } |
1802 | ||
c88fd863 | 1803 | static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update) |
5072c59f | 1804 | { |
64fbcd16 | 1805 | unsigned long flag = 0UL; |
e7d3737e | 1806 | |
982c350b | 1807 | /* |
30fb6aa7 | 1808 | * If we are updating calls: |
982c350b | 1809 | * |
ed926f9b SR |
1810 | * If the record has a ref count, then we need to enable it |
1811 | * because someone is using it. | |
982c350b | 1812 | * |
ed926f9b SR |
1813 | * Otherwise we make sure its disabled. |
1814 | * | |
30fb6aa7 | 1815 | * If we are disabling calls, then disable all records that |
ed926f9b | 1816 | * are enabled. |
982c350b | 1817 | */ |
0376bde1 | 1818 | if (enable && ftrace_rec_count(rec)) |
ed926f9b | 1819 | flag = FTRACE_FL_ENABLED; |
982c350b | 1820 | |
08f6fba5 | 1821 | /* |
79922b80 SRRH |
1822 | * If enabling and the REGS flag does not match the REGS_EN, or |
1823 | * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore | |
1824 | * this record. Set flags to fail the compare against ENABLED. | |
08f6fba5 | 1825 | */ |
79922b80 SRRH |
1826 | if (flag) { |
1827 | if (!(rec->flags & FTRACE_FL_REGS) != | |
1828 | !(rec->flags & FTRACE_FL_REGS_EN)) | |
1829 | flag |= FTRACE_FL_REGS; | |
1830 | ||
1831 | if (!(rec->flags & FTRACE_FL_TRAMP) != | |
1832 | !(rec->flags & FTRACE_FL_TRAMP_EN)) | |
1833 | flag |= FTRACE_FL_TRAMP; | |
1834 | } | |
08f6fba5 | 1835 | |
64fbcd16 XG |
1836 | /* If the state of this record hasn't changed, then do nothing */ |
1837 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
c88fd863 | 1838 | return FTRACE_UPDATE_IGNORE; |
982c350b | 1839 | |
64fbcd16 | 1840 | if (flag) { |
08f6fba5 SR |
1841 | /* Save off if rec is being enabled (for return value) */ |
1842 | flag ^= rec->flags & FTRACE_FL_ENABLED; | |
1843 | ||
1844 | if (update) { | |
c88fd863 | 1845 | rec->flags |= FTRACE_FL_ENABLED; |
08f6fba5 SR |
1846 | if (flag & FTRACE_FL_REGS) { |
1847 | if (rec->flags & FTRACE_FL_REGS) | |
1848 | rec->flags |= FTRACE_FL_REGS_EN; | |
1849 | else | |
1850 | rec->flags &= ~FTRACE_FL_REGS_EN; | |
1851 | } | |
79922b80 SRRH |
1852 | if (flag & FTRACE_FL_TRAMP) { |
1853 | if (rec->flags & FTRACE_FL_TRAMP) | |
1854 | rec->flags |= FTRACE_FL_TRAMP_EN; | |
1855 | else | |
1856 | rec->flags &= ~FTRACE_FL_TRAMP_EN; | |
1857 | } | |
08f6fba5 SR |
1858 | } |
1859 | ||
1860 | /* | |
1861 | * If this record is being updated from a nop, then | |
1862 | * return UPDATE_MAKE_CALL. | |
08f6fba5 SR |
1863 | * Otherwise, |
1864 | * return UPDATE_MODIFY_CALL to tell the caller to convert | |
f1b2f2bd | 1865 | * from the save regs, to a non-save regs function or |
79922b80 | 1866 | * vice versa, or from a trampoline call. |
08f6fba5 SR |
1867 | */ |
1868 | if (flag & FTRACE_FL_ENABLED) | |
1869 | return FTRACE_UPDATE_MAKE_CALL; | |
f1b2f2bd SRRH |
1870 | |
1871 | return FTRACE_UPDATE_MODIFY_CALL; | |
c88fd863 SR |
1872 | } |
1873 | ||
08f6fba5 SR |
1874 | if (update) { |
1875 | /* If there's no more users, clear all flags */ | |
0376bde1 | 1876 | if (!ftrace_rec_count(rec)) |
08f6fba5 SR |
1877 | rec->flags = 0; |
1878 | else | |
1879 | /* Just disable the record (keep REGS state) */ | |
1880 | rec->flags &= ~FTRACE_FL_ENABLED; | |
1881 | } | |
c88fd863 SR |
1882 | |
1883 | return FTRACE_UPDATE_MAKE_NOP; | |
1884 | } | |
1885 | ||
1886 | /** | |
1887 | * ftrace_update_record, set a record that now is tracing or not | |
1888 | * @rec: the record to update | |
1889 | * @enable: set to 1 if the record is tracing, zero to force disable | |
1890 | * | |
1891 | * The records that represent all functions that can be traced need | |
1892 | * to be updated when tracing has been enabled. | |
1893 | */ | |
1894 | int ftrace_update_record(struct dyn_ftrace *rec, int enable) | |
1895 | { | |
1896 | return ftrace_check_record(rec, enable, 1); | |
1897 | } | |
1898 | ||
1899 | /** | |
1900 | * ftrace_test_record, check if the record has been enabled or not | |
1901 | * @rec: the record to test | |
1902 | * @enable: set to 1 to check if enabled, 0 if it is disabled | |
1903 | * | |
1904 | * The arch code may need to test if a record is already set to | |
1905 | * tracing to determine how to modify the function code that it | |
1906 | * represents. | |
1907 | */ | |
1908 | int ftrace_test_record(struct dyn_ftrace *rec, int enable) | |
1909 | { | |
1910 | return ftrace_check_record(rec, enable, 0); | |
1911 | } | |
1912 | ||
5fecaa04 SRRH |
1913 | static struct ftrace_ops * |
1914 | ftrace_find_tramp_ops_any(struct dyn_ftrace *rec) | |
1915 | { | |
1916 | struct ftrace_ops *op; | |
fef5aeee | 1917 | unsigned long ip = rec->ip; |
5fecaa04 SRRH |
1918 | |
1919 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1920 | ||
1921 | if (!op->trampoline) | |
1922 | continue; | |
1923 | ||
fef5aeee | 1924 | if (hash_contains_ip(ip, op->func_hash)) |
5fecaa04 SRRH |
1925 | return op; |
1926 | } while_for_each_ftrace_op(op); | |
1927 | ||
1928 | return NULL; | |
1929 | } | |
1930 | ||
79922b80 SRRH |
1931 | static struct ftrace_ops * |
1932 | ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec) | |
1933 | { | |
1934 | struct ftrace_ops *op; | |
fef5aeee | 1935 | unsigned long ip = rec->ip; |
79922b80 | 1936 | |
fef5aeee SRRH |
1937 | /* |
1938 | * Need to check removed ops first. | |
1939 | * If they are being removed, and this rec has a tramp, | |
1940 | * and this rec is in the ops list, then it would be the | |
1941 | * one with the tramp. | |
1942 | */ | |
1943 | if (removed_ops) { | |
1944 | if (hash_contains_ip(ip, &removed_ops->old_hash)) | |
79922b80 SRRH |
1945 | return removed_ops; |
1946 | } | |
1947 | ||
fef5aeee SRRH |
1948 | /* |
1949 | * Need to find the current trampoline for a rec. | |
1950 | * Now, a trampoline is only attached to a rec if there | |
1951 | * was a single 'ops' attached to it. But this can be called | |
1952 | * when we are adding another op to the rec or removing the | |
1953 | * current one. Thus, if the op is being added, we can | |
1954 | * ignore it because it hasn't attached itself to the rec | |
4fc40904 SRRH |
1955 | * yet. |
1956 | * | |
1957 | * If an ops is being modified (hooking to different functions) | |
1958 | * then we don't care about the new functions that are being | |
1959 | * added, just the old ones (that are probably being removed). | |
1960 | * | |
1961 | * If we are adding an ops to a function that already is using | |
1962 | * a trampoline, it needs to be removed (trampolines are only | |
1963 | * for single ops connected), then an ops that is not being | |
1964 | * modified also needs to be checked. | |
fef5aeee | 1965 | */ |
79922b80 | 1966 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
fef5aeee SRRH |
1967 | |
1968 | if (!op->trampoline) | |
1969 | continue; | |
1970 | ||
1971 | /* | |
1972 | * If the ops is being added, it hasn't gotten to | |
1973 | * the point to be removed from this tree yet. | |
1974 | */ | |
1975 | if (op->flags & FTRACE_OPS_FL_ADDING) | |
79922b80 SRRH |
1976 | continue; |
1977 | ||
4fc40904 | 1978 | |
fef5aeee | 1979 | /* |
4fc40904 SRRH |
1980 | * If the ops is being modified and is in the old |
1981 | * hash, then it is probably being removed from this | |
1982 | * function. | |
fef5aeee | 1983 | */ |
fef5aeee SRRH |
1984 | if ((op->flags & FTRACE_OPS_FL_MODIFYING) && |
1985 | hash_contains_ip(ip, &op->old_hash)) | |
79922b80 | 1986 | return op; |
4fc40904 SRRH |
1987 | /* |
1988 | * If the ops is not being added or modified, and it's | |
1989 | * in its normal filter hash, then this must be the one | |
1990 | * we want! | |
1991 | */ | |
1992 | if (!(op->flags & FTRACE_OPS_FL_MODIFYING) && | |
1993 | hash_contains_ip(ip, op->func_hash)) | |
1994 | return op; | |
79922b80 SRRH |
1995 | |
1996 | } while_for_each_ftrace_op(op); | |
1997 | ||
1998 | return NULL; | |
1999 | } | |
2000 | ||
2001 | static struct ftrace_ops * | |
2002 | ftrace_find_tramp_ops_new(struct dyn_ftrace *rec) | |
2003 | { | |
2004 | struct ftrace_ops *op; | |
fef5aeee | 2005 | unsigned long ip = rec->ip; |
79922b80 SRRH |
2006 | |
2007 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2008 | /* pass rec in as regs to have non-NULL val */ | |
fef5aeee | 2009 | if (hash_contains_ip(ip, op->func_hash)) |
79922b80 SRRH |
2010 | return op; |
2011 | } while_for_each_ftrace_op(op); | |
2012 | ||
2013 | return NULL; | |
2014 | } | |
2015 | ||
7413af1f SRRH |
2016 | /** |
2017 | * ftrace_get_addr_new - Get the call address to set to | |
2018 | * @rec: The ftrace record descriptor | |
2019 | * | |
2020 | * If the record has the FTRACE_FL_REGS set, that means that it | |
2021 | * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS | |
2022 | * is not not set, then it wants to convert to the normal callback. | |
2023 | * | |
2024 | * Returns the address of the trampoline to set to | |
2025 | */ | |
2026 | unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec) | |
2027 | { | |
79922b80 SRRH |
2028 | struct ftrace_ops *ops; |
2029 | ||
2030 | /* Trampolines take precedence over regs */ | |
2031 | if (rec->flags & FTRACE_FL_TRAMP) { | |
2032 | ops = ftrace_find_tramp_ops_new(rec); | |
2033 | if (FTRACE_WARN_ON(!ops || !ops->trampoline)) { | |
bce0b6c5 SRRH |
2034 | pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n", |
2035 | (void *)rec->ip, (void *)rec->ip, rec->flags); | |
79922b80 SRRH |
2036 | /* Ftrace is shutting down, return anything */ |
2037 | return (unsigned long)FTRACE_ADDR; | |
2038 | } | |
2039 | return ops->trampoline; | |
2040 | } | |
2041 | ||
7413af1f SRRH |
2042 | if (rec->flags & FTRACE_FL_REGS) |
2043 | return (unsigned long)FTRACE_REGS_ADDR; | |
2044 | else | |
2045 | return (unsigned long)FTRACE_ADDR; | |
2046 | } | |
2047 | ||
2048 | /** | |
2049 | * ftrace_get_addr_curr - Get the call address that is already there | |
2050 | * @rec: The ftrace record descriptor | |
2051 | * | |
2052 | * The FTRACE_FL_REGS_EN is set when the record already points to | |
2053 | * a function that saves all the regs. Basically the '_EN' version | |
2054 | * represents the current state of the function. | |
2055 | * | |
2056 | * Returns the address of the trampoline that is currently being called | |
2057 | */ | |
2058 | unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec) | |
2059 | { | |
79922b80 SRRH |
2060 | struct ftrace_ops *ops; |
2061 | ||
2062 | /* Trampolines take precedence over regs */ | |
2063 | if (rec->flags & FTRACE_FL_TRAMP_EN) { | |
2064 | ops = ftrace_find_tramp_ops_curr(rec); | |
2065 | if (FTRACE_WARN_ON(!ops)) { | |
2066 | pr_warning("Bad trampoline accounting at: %p (%pS)\n", | |
2067 | (void *)rec->ip, (void *)rec->ip); | |
2068 | /* Ftrace is shutting down, return anything */ | |
2069 | return (unsigned long)FTRACE_ADDR; | |
2070 | } | |
2071 | return ops->trampoline; | |
2072 | } | |
2073 | ||
7413af1f SRRH |
2074 | if (rec->flags & FTRACE_FL_REGS_EN) |
2075 | return (unsigned long)FTRACE_REGS_ADDR; | |
2076 | else | |
2077 | return (unsigned long)FTRACE_ADDR; | |
2078 | } | |
2079 | ||
c88fd863 SR |
2080 | static int |
2081 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) | |
2082 | { | |
08f6fba5 | 2083 | unsigned long ftrace_old_addr; |
c88fd863 SR |
2084 | unsigned long ftrace_addr; |
2085 | int ret; | |
2086 | ||
7c0868e0 | 2087 | ftrace_addr = ftrace_get_addr_new(rec); |
c88fd863 | 2088 | |
7c0868e0 SRRH |
2089 | /* This needs to be done before we call ftrace_update_record */ |
2090 | ftrace_old_addr = ftrace_get_addr_curr(rec); | |
2091 | ||
2092 | ret = ftrace_update_record(rec, enable); | |
08f6fba5 | 2093 | |
c88fd863 SR |
2094 | switch (ret) { |
2095 | case FTRACE_UPDATE_IGNORE: | |
2096 | return 0; | |
2097 | ||
2098 | case FTRACE_UPDATE_MAKE_CALL: | |
64fbcd16 | 2099 | return ftrace_make_call(rec, ftrace_addr); |
c88fd863 SR |
2100 | |
2101 | case FTRACE_UPDATE_MAKE_NOP: | |
39b5552c | 2102 | return ftrace_make_nop(NULL, rec, ftrace_old_addr); |
08f6fba5 | 2103 | |
08f6fba5 | 2104 | case FTRACE_UPDATE_MODIFY_CALL: |
08f6fba5 | 2105 | return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr); |
5072c59f SR |
2106 | } |
2107 | ||
c88fd863 | 2108 | return -1; /* unknow ftrace bug */ |
5072c59f SR |
2109 | } |
2110 | ||
e4f5d544 | 2111 | void __weak ftrace_replace_code(int enable) |
3c1720f0 | 2112 | { |
3c1720f0 SR |
2113 | struct dyn_ftrace *rec; |
2114 | struct ftrace_page *pg; | |
6a24a244 | 2115 | int failed; |
3c1720f0 | 2116 | |
45a4a237 SR |
2117 | if (unlikely(ftrace_disabled)) |
2118 | return; | |
2119 | ||
265c831c | 2120 | do_for_each_ftrace_rec(pg, rec) { |
e4f5d544 | 2121 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 2122 | if (failed) { |
4fd3279b | 2123 | ftrace_bug(failed, rec); |
3279ba37 SR |
2124 | /* Stop processing */ |
2125 | return; | |
3c1720f0 | 2126 | } |
265c831c | 2127 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
2128 | } |
2129 | ||
c88fd863 SR |
2130 | struct ftrace_rec_iter { |
2131 | struct ftrace_page *pg; | |
2132 | int index; | |
2133 | }; | |
2134 | ||
2135 | /** | |
2136 | * ftrace_rec_iter_start, start up iterating over traced functions | |
2137 | * | |
2138 | * Returns an iterator handle that is used to iterate over all | |
2139 | * the records that represent address locations where functions | |
2140 | * are traced. | |
2141 | * | |
2142 | * May return NULL if no records are available. | |
2143 | */ | |
2144 | struct ftrace_rec_iter *ftrace_rec_iter_start(void) | |
2145 | { | |
2146 | /* | |
2147 | * We only use a single iterator. | |
2148 | * Protected by the ftrace_lock mutex. | |
2149 | */ | |
2150 | static struct ftrace_rec_iter ftrace_rec_iter; | |
2151 | struct ftrace_rec_iter *iter = &ftrace_rec_iter; | |
2152 | ||
2153 | iter->pg = ftrace_pages_start; | |
2154 | iter->index = 0; | |
2155 | ||
2156 | /* Could have empty pages */ | |
2157 | while (iter->pg && !iter->pg->index) | |
2158 | iter->pg = iter->pg->next; | |
2159 | ||
2160 | if (!iter->pg) | |
2161 | return NULL; | |
2162 | ||
2163 | return iter; | |
2164 | } | |
2165 | ||
2166 | /** | |
2167 | * ftrace_rec_iter_next, get the next record to process. | |
2168 | * @iter: The handle to the iterator. | |
2169 | * | |
2170 | * Returns the next iterator after the given iterator @iter. | |
2171 | */ | |
2172 | struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) | |
2173 | { | |
2174 | iter->index++; | |
2175 | ||
2176 | if (iter->index >= iter->pg->index) { | |
2177 | iter->pg = iter->pg->next; | |
2178 | iter->index = 0; | |
2179 | ||
2180 | /* Could have empty pages */ | |
2181 | while (iter->pg && !iter->pg->index) | |
2182 | iter->pg = iter->pg->next; | |
2183 | } | |
2184 | ||
2185 | if (!iter->pg) | |
2186 | return NULL; | |
2187 | ||
2188 | return iter; | |
2189 | } | |
2190 | ||
2191 | /** | |
2192 | * ftrace_rec_iter_record, get the record at the iterator location | |
2193 | * @iter: The current iterator location | |
2194 | * | |
2195 | * Returns the record that the current @iter is at. | |
2196 | */ | |
2197 | struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) | |
2198 | { | |
2199 | return &iter->pg->records[iter->index]; | |
2200 | } | |
2201 | ||
492a7ea5 | 2202 | static int |
31e88909 | 2203 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 | 2204 | { |
593eb8a2 | 2205 | int ret; |
3c1720f0 | 2206 | |
45a4a237 SR |
2207 | if (unlikely(ftrace_disabled)) |
2208 | return 0; | |
2209 | ||
25aac9dc | 2210 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 2211 | if (ret) { |
4fd3279b | 2212 | ftrace_bug(ret, rec); |
492a7ea5 | 2213 | return 0; |
37ad5084 | 2214 | } |
492a7ea5 | 2215 | return 1; |
3c1720f0 SR |
2216 | } |
2217 | ||
000ab691 SR |
2218 | /* |
2219 | * archs can override this function if they must do something | |
2220 | * before the modifying code is performed. | |
2221 | */ | |
2222 | int __weak ftrace_arch_code_modify_prepare(void) | |
2223 | { | |
2224 | return 0; | |
2225 | } | |
2226 | ||
2227 | /* | |
2228 | * archs can override this function if they must do something | |
2229 | * after the modifying code is performed. | |
2230 | */ | |
2231 | int __weak ftrace_arch_code_modify_post_process(void) | |
2232 | { | |
2233 | return 0; | |
2234 | } | |
2235 | ||
8ed3e2cf | 2236 | void ftrace_modify_all_code(int command) |
3d083395 | 2237 | { |
59338f75 | 2238 | int update = command & FTRACE_UPDATE_TRACE_FUNC; |
cd21067f | 2239 | int err = 0; |
59338f75 SRRH |
2240 | |
2241 | /* | |
2242 | * If the ftrace_caller calls a ftrace_ops func directly, | |
2243 | * we need to make sure that it only traces functions it | |
2244 | * expects to trace. When doing the switch of functions, | |
2245 | * we need to update to the ftrace_ops_list_func first | |
2246 | * before the transition between old and new calls are set, | |
2247 | * as the ftrace_ops_list_func will check the ops hashes | |
2248 | * to make sure the ops are having the right functions | |
2249 | * traced. | |
2250 | */ | |
cd21067f PM |
2251 | if (update) { |
2252 | err = ftrace_update_ftrace_func(ftrace_ops_list_func); | |
2253 | if (FTRACE_WARN_ON(err)) | |
2254 | return; | |
2255 | } | |
59338f75 | 2256 | |
8ed3e2cf | 2257 | if (command & FTRACE_UPDATE_CALLS) |
d61f82d0 | 2258 | ftrace_replace_code(1); |
8ed3e2cf | 2259 | else if (command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
2260 | ftrace_replace_code(0); |
2261 | ||
405e1d83 SRRH |
2262 | if (update && ftrace_trace_function != ftrace_ops_list_func) { |
2263 | function_trace_op = set_function_trace_op; | |
2264 | smp_wmb(); | |
2265 | /* If irqs are disabled, we are in stop machine */ | |
2266 | if (!irqs_disabled()) | |
2267 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
cd21067f PM |
2268 | err = ftrace_update_ftrace_func(ftrace_trace_function); |
2269 | if (FTRACE_WARN_ON(err)) | |
2270 | return; | |
405e1d83 | 2271 | } |
d61f82d0 | 2272 | |
8ed3e2cf | 2273 | if (command & FTRACE_START_FUNC_RET) |
cd21067f | 2274 | err = ftrace_enable_ftrace_graph_caller(); |
8ed3e2cf | 2275 | else if (command & FTRACE_STOP_FUNC_RET) |
cd21067f PM |
2276 | err = ftrace_disable_ftrace_graph_caller(); |
2277 | FTRACE_WARN_ON(err); | |
8ed3e2cf SR |
2278 | } |
2279 | ||
2280 | static int __ftrace_modify_code(void *data) | |
2281 | { | |
2282 | int *command = data; | |
2283 | ||
2284 | ftrace_modify_all_code(*command); | |
5a45cfe1 | 2285 | |
d61f82d0 | 2286 | return 0; |
3d083395 SR |
2287 | } |
2288 | ||
c88fd863 SR |
2289 | /** |
2290 | * ftrace_run_stop_machine, go back to the stop machine method | |
2291 | * @command: The command to tell ftrace what to do | |
2292 | * | |
2293 | * If an arch needs to fall back to the stop machine method, the | |
2294 | * it can call this function. | |
2295 | */ | |
2296 | void ftrace_run_stop_machine(int command) | |
2297 | { | |
2298 | stop_machine(__ftrace_modify_code, &command, NULL); | |
2299 | } | |
2300 | ||
2301 | /** | |
2302 | * arch_ftrace_update_code, modify the code to trace or not trace | |
2303 | * @command: The command that needs to be done | |
2304 | * | |
2305 | * Archs can override this function if it does not need to | |
2306 | * run stop_machine() to modify code. | |
2307 | */ | |
2308 | void __weak arch_ftrace_update_code(int command) | |
2309 | { | |
2310 | ftrace_run_stop_machine(command); | |
2311 | } | |
2312 | ||
e309b41d | 2313 | static void ftrace_run_update_code(int command) |
3d083395 | 2314 | { |
000ab691 SR |
2315 | int ret; |
2316 | ||
2317 | ret = ftrace_arch_code_modify_prepare(); | |
2318 | FTRACE_WARN_ON(ret); | |
2319 | if (ret) | |
2320 | return; | |
2321 | ||
c88fd863 SR |
2322 | /* |
2323 | * By default we use stop_machine() to modify the code. | |
2324 | * But archs can do what ever they want as long as it | |
2325 | * is safe. The stop_machine() is the safest, but also | |
2326 | * produces the most overhead. | |
2327 | */ | |
2328 | arch_ftrace_update_code(command); | |
2329 | ||
000ab691 SR |
2330 | ret = ftrace_arch_code_modify_post_process(); |
2331 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
2332 | } |
2333 | ||
8252ecf3 SRRH |
2334 | static void ftrace_run_modify_code(struct ftrace_ops *ops, int command, |
2335 | struct ftrace_hash *old_hash) | |
e1effa01 SRRH |
2336 | { |
2337 | ops->flags |= FTRACE_OPS_FL_MODIFYING; | |
8252ecf3 | 2338 | ops->old_hash.filter_hash = old_hash; |
e1effa01 | 2339 | ftrace_run_update_code(command); |
8252ecf3 | 2340 | ops->old_hash.filter_hash = NULL; |
e1effa01 SRRH |
2341 | ops->flags &= ~FTRACE_OPS_FL_MODIFYING; |
2342 | } | |
2343 | ||
d61f82d0 | 2344 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 2345 | static int ftrace_start_up; |
df4fc315 | 2346 | |
12cce594 SRRH |
2347 | void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops) |
2348 | { | |
2349 | } | |
2350 | ||
db0fbadc JS |
2351 | static void control_ops_free(struct ftrace_ops *ops) |
2352 | { | |
2353 | free_percpu(ops->disabled); | |
2354 | } | |
2355 | ||
df4fc315 SR |
2356 | static void ftrace_startup_enable(int command) |
2357 | { | |
2358 | if (saved_ftrace_func != ftrace_trace_function) { | |
2359 | saved_ftrace_func = ftrace_trace_function; | |
2360 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2361 | } | |
2362 | ||
2363 | if (!command || !ftrace_enabled) | |
2364 | return; | |
2365 | ||
2366 | ftrace_run_update_code(command); | |
2367 | } | |
d61f82d0 | 2368 | |
e1effa01 SRRH |
2369 | static void ftrace_startup_all(int command) |
2370 | { | |
2371 | update_all_ops = true; | |
2372 | ftrace_startup_enable(command); | |
2373 | update_all_ops = false; | |
2374 | } | |
2375 | ||
a1cd6173 | 2376 | static int ftrace_startup(struct ftrace_ops *ops, int command) |
3d083395 | 2377 | { |
8a56d776 | 2378 | int ret; |
b848914c | 2379 | |
4eebcc81 | 2380 | if (unlikely(ftrace_disabled)) |
a1cd6173 | 2381 | return -ENODEV; |
4eebcc81 | 2382 | |
8a56d776 SRRH |
2383 | ret = __register_ftrace_function(ops); |
2384 | if (ret) | |
2385 | return ret; | |
2386 | ||
60a7ecf4 | 2387 | ftrace_start_up++; |
30fb6aa7 | 2388 | command |= FTRACE_UPDATE_CALLS; |
d61f82d0 | 2389 | |
e1effa01 SRRH |
2390 | /* |
2391 | * Note that ftrace probes uses this to start up | |
2392 | * and modify functions it will probe. But we still | |
2393 | * set the ADDING flag for modification, as probes | |
2394 | * do not have trampolines. If they add them in the | |
2395 | * future, then the probes will need to distinguish | |
2396 | * between adding and updating probes. | |
2397 | */ | |
2398 | ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING; | |
66209a5b SRRH |
2399 | |
2400 | ftrace_hash_rec_enable(ops, 1); | |
ed926f9b | 2401 | |
df4fc315 | 2402 | ftrace_startup_enable(command); |
a1cd6173 | 2403 | |
e1effa01 SRRH |
2404 | ops->flags &= ~FTRACE_OPS_FL_ADDING; |
2405 | ||
a1cd6173 | 2406 | return 0; |
3d083395 SR |
2407 | } |
2408 | ||
8a56d776 | 2409 | static int ftrace_shutdown(struct ftrace_ops *ops, int command) |
3d083395 | 2410 | { |
8a56d776 | 2411 | int ret; |
b848914c | 2412 | |
4eebcc81 | 2413 | if (unlikely(ftrace_disabled)) |
8a56d776 SRRH |
2414 | return -ENODEV; |
2415 | ||
2416 | ret = __unregister_ftrace_function(ops); | |
2417 | if (ret) | |
2418 | return ret; | |
4eebcc81 | 2419 | |
60a7ecf4 | 2420 | ftrace_start_up--; |
9ea1a153 FW |
2421 | /* |
2422 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
2423 | * critical but the ftrace_call callers may be never nopped again after | |
2424 | * further ftrace uses. | |
2425 | */ | |
2426 | WARN_ON_ONCE(ftrace_start_up < 0); | |
2427 | ||
66209a5b | 2428 | ftrace_hash_rec_disable(ops, 1); |
ed926f9b | 2429 | |
a737e6dd | 2430 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
b848914c | 2431 | |
30fb6aa7 | 2432 | command |= FTRACE_UPDATE_CALLS; |
3d083395 | 2433 | |
d61f82d0 SR |
2434 | if (saved_ftrace_func != ftrace_trace_function) { |
2435 | saved_ftrace_func = ftrace_trace_function; | |
2436 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2437 | } | |
3d083395 | 2438 | |
a4c35ed2 SRRH |
2439 | if (!command || !ftrace_enabled) { |
2440 | /* | |
2441 | * If these are control ops, they still need their | |
2442 | * per_cpu field freed. Since, function tracing is | |
2443 | * not currently active, we can just free them | |
2444 | * without synchronizing all CPUs. | |
2445 | */ | |
2446 | if (ops->flags & FTRACE_OPS_FL_CONTROL) | |
2447 | control_ops_free(ops); | |
8a56d776 | 2448 | return 0; |
a4c35ed2 | 2449 | } |
d61f82d0 | 2450 | |
79922b80 SRRH |
2451 | /* |
2452 | * If the ops uses a trampoline, then it needs to be | |
2453 | * tested first on update. | |
2454 | */ | |
e1effa01 | 2455 | ops->flags |= FTRACE_OPS_FL_REMOVING; |
79922b80 SRRH |
2456 | removed_ops = ops; |
2457 | ||
fef5aeee SRRH |
2458 | /* The trampoline logic checks the old hashes */ |
2459 | ops->old_hash.filter_hash = ops->func_hash->filter_hash; | |
2460 | ops->old_hash.notrace_hash = ops->func_hash->notrace_hash; | |
2461 | ||
d61f82d0 | 2462 | ftrace_run_update_code(command); |
a4c35ed2 | 2463 | |
84bde62c SRRH |
2464 | /* |
2465 | * If there's no more ops registered with ftrace, run a | |
2466 | * sanity check to make sure all rec flags are cleared. | |
2467 | */ | |
2468 | if (ftrace_ops_list == &ftrace_list_end) { | |
2469 | struct ftrace_page *pg; | |
2470 | struct dyn_ftrace *rec; | |
2471 | ||
2472 | do_for_each_ftrace_rec(pg, rec) { | |
2473 | if (FTRACE_WARN_ON_ONCE(rec->flags)) | |
2474 | pr_warn(" %pS flags:%lx\n", | |
2475 | (void *)rec->ip, rec->flags); | |
2476 | } while_for_each_ftrace_rec(); | |
2477 | } | |
2478 | ||
fef5aeee SRRH |
2479 | ops->old_hash.filter_hash = NULL; |
2480 | ops->old_hash.notrace_hash = NULL; | |
2481 | ||
2482 | removed_ops = NULL; | |
e1effa01 | 2483 | ops->flags &= ~FTRACE_OPS_FL_REMOVING; |
79922b80 | 2484 | |
a4c35ed2 SRRH |
2485 | /* |
2486 | * Dynamic ops may be freed, we must make sure that all | |
2487 | * callers are done before leaving this function. | |
2488 | * The same goes for freeing the per_cpu data of the control | |
2489 | * ops. | |
2490 | * | |
2491 | * Again, normal synchronize_sched() is not good enough. | |
2492 | * We need to do a hard force of sched synchronization. | |
2493 | * This is because we use preempt_disable() to do RCU, but | |
2494 | * the function tracers can be called where RCU is not watching | |
2495 | * (like before user_exit()). We can not rely on the RCU | |
2496 | * infrastructure to do the synchronization, thus we must do it | |
2497 | * ourselves. | |
2498 | */ | |
2499 | if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_CONTROL)) { | |
2500 | schedule_on_each_cpu(ftrace_sync); | |
2501 | ||
12cce594 SRRH |
2502 | arch_ftrace_trampoline_free(ops); |
2503 | ||
a4c35ed2 SRRH |
2504 | if (ops->flags & FTRACE_OPS_FL_CONTROL) |
2505 | control_ops_free(ops); | |
2506 | } | |
2507 | ||
8a56d776 | 2508 | return 0; |
3d083395 SR |
2509 | } |
2510 | ||
e309b41d | 2511 | static void ftrace_startup_sysctl(void) |
b0fc494f | 2512 | { |
4eebcc81 SR |
2513 | if (unlikely(ftrace_disabled)) |
2514 | return; | |
2515 | ||
d61f82d0 SR |
2516 | /* Force update next time */ |
2517 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
2518 | /* ftrace_start_up is true if we want ftrace running */ |
2519 | if (ftrace_start_up) | |
30fb6aa7 | 2520 | ftrace_run_update_code(FTRACE_UPDATE_CALLS); |
b0fc494f SR |
2521 | } |
2522 | ||
e309b41d | 2523 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 2524 | { |
4eebcc81 SR |
2525 | if (unlikely(ftrace_disabled)) |
2526 | return; | |
2527 | ||
60a7ecf4 SR |
2528 | /* ftrace_start_up is true if ftrace is running */ |
2529 | if (ftrace_start_up) | |
79e406d7 | 2530 | ftrace_run_update_code(FTRACE_DISABLE_CALLS); |
b0fc494f SR |
2531 | } |
2532 | ||
3d083395 | 2533 | static cycle_t ftrace_update_time; |
3d083395 SR |
2534 | unsigned long ftrace_update_tot_cnt; |
2535 | ||
8c4f3c3f | 2536 | static inline int ops_traces_mod(struct ftrace_ops *ops) |
f7bc8b61 | 2537 | { |
8c4f3c3f SRRH |
2538 | /* |
2539 | * Filter_hash being empty will default to trace module. | |
2540 | * But notrace hash requires a test of individual module functions. | |
2541 | */ | |
33b7f99c SRRH |
2542 | return ftrace_hash_empty(ops->func_hash->filter_hash) && |
2543 | ftrace_hash_empty(ops->func_hash->notrace_hash); | |
8c4f3c3f SRRH |
2544 | } |
2545 | ||
2546 | /* | |
2547 | * Check if the current ops references the record. | |
2548 | * | |
2549 | * If the ops traces all functions, then it was already accounted for. | |
2550 | * If the ops does not trace the current record function, skip it. | |
2551 | * If the ops ignores the function via notrace filter, skip it. | |
2552 | */ | |
2553 | static inline bool | |
2554 | ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec) | |
2555 | { | |
2556 | /* If ops isn't enabled, ignore it */ | |
2557 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
2558 | return 0; | |
2559 | ||
2560 | /* If ops traces all mods, we already accounted for it */ | |
2561 | if (ops_traces_mod(ops)) | |
2562 | return 0; | |
2563 | ||
2564 | /* The function must be in the filter */ | |
33b7f99c SRRH |
2565 | if (!ftrace_hash_empty(ops->func_hash->filter_hash) && |
2566 | !ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip)) | |
8c4f3c3f | 2567 | return 0; |
f7bc8b61 | 2568 | |
8c4f3c3f | 2569 | /* If in notrace hash, we ignore it too */ |
33b7f99c | 2570 | if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip)) |
8c4f3c3f SRRH |
2571 | return 0; |
2572 | ||
2573 | return 1; | |
2574 | } | |
2575 | ||
2576 | static int referenced_filters(struct dyn_ftrace *rec) | |
2577 | { | |
2578 | struct ftrace_ops *ops; | |
2579 | int cnt = 0; | |
2580 | ||
2581 | for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) { | |
2582 | if (ops_references_rec(ops, rec)) | |
2583 | cnt++; | |
2584 | } | |
2585 | ||
2586 | return cnt; | |
f7bc8b61 SR |
2587 | } |
2588 | ||
1dc43cf0 | 2589 | static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs) |
3d083395 | 2590 | { |
85ae32ae | 2591 | struct ftrace_page *pg; |
e94142a6 | 2592 | struct dyn_ftrace *p; |
f22f9a89 | 2593 | cycle_t start, stop; |
1dc43cf0 | 2594 | unsigned long update_cnt = 0; |
f7bc8b61 | 2595 | unsigned long ref = 0; |
8c4f3c3f | 2596 | bool test = false; |
85ae32ae | 2597 | int i; |
f7bc8b61 SR |
2598 | |
2599 | /* | |
2600 | * When adding a module, we need to check if tracers are | |
2601 | * currently enabled and if they are set to trace all functions. | |
2602 | * If they are, we need to enable the module functions as well | |
2603 | * as update the reference counts for those function records. | |
2604 | */ | |
2605 | if (mod) { | |
2606 | struct ftrace_ops *ops; | |
2607 | ||
2608 | for (ops = ftrace_ops_list; | |
2609 | ops != &ftrace_list_end; ops = ops->next) { | |
8c4f3c3f SRRH |
2610 | if (ops->flags & FTRACE_OPS_FL_ENABLED) { |
2611 | if (ops_traces_mod(ops)) | |
2612 | ref++; | |
2613 | else | |
2614 | test = true; | |
2615 | } | |
f7bc8b61 SR |
2616 | } |
2617 | } | |
3d083395 | 2618 | |
750ed1a4 | 2619 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 | 2620 | |
1dc43cf0 | 2621 | for (pg = new_pgs; pg; pg = pg->next) { |
3d083395 | 2622 | |
85ae32ae | 2623 | for (i = 0; i < pg->index; i++) { |
8c4f3c3f SRRH |
2624 | int cnt = ref; |
2625 | ||
85ae32ae SR |
2626 | /* If something went wrong, bail without enabling anything */ |
2627 | if (unlikely(ftrace_disabled)) | |
2628 | return -1; | |
f22f9a89 | 2629 | |
85ae32ae | 2630 | p = &pg->records[i]; |
8c4f3c3f SRRH |
2631 | if (test) |
2632 | cnt += referenced_filters(p); | |
2633 | p->flags = cnt; | |
f22f9a89 | 2634 | |
85ae32ae SR |
2635 | /* |
2636 | * Do the initial record conversion from mcount jump | |
2637 | * to the NOP instructions. | |
2638 | */ | |
2639 | if (!ftrace_code_disable(mod, p)) | |
2640 | break; | |
5cb084bb | 2641 | |
1dc43cf0 | 2642 | update_cnt++; |
5cb084bb | 2643 | |
85ae32ae SR |
2644 | /* |
2645 | * If the tracing is enabled, go ahead and enable the record. | |
2646 | * | |
2647 | * The reason not to enable the record immediatelly is the | |
2648 | * inherent check of ftrace_make_nop/ftrace_make_call for | |
2649 | * correct previous instructions. Making first the NOP | |
2650 | * conversion puts the module to the correct state, thus | |
2651 | * passing the ftrace_make_call check. | |
2652 | */ | |
8c4f3c3f | 2653 | if (ftrace_start_up && cnt) { |
85ae32ae SR |
2654 | int failed = __ftrace_replace_code(p, 1); |
2655 | if (failed) | |
4fd3279b | 2656 | ftrace_bug(failed, p); |
85ae32ae | 2657 | } |
5cb084bb | 2658 | } |
3d083395 SR |
2659 | } |
2660 | ||
750ed1a4 | 2661 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 | 2662 | ftrace_update_time = stop - start; |
1dc43cf0 | 2663 | ftrace_update_tot_cnt += update_cnt; |
3d083395 | 2664 | |
16444a8a ACM |
2665 | return 0; |
2666 | } | |
2667 | ||
a7900875 | 2668 | static int ftrace_allocate_records(struct ftrace_page *pg, int count) |
3c1720f0 | 2669 | { |
a7900875 | 2670 | int order; |
3c1720f0 | 2671 | int cnt; |
3c1720f0 | 2672 | |
a7900875 SR |
2673 | if (WARN_ON(!count)) |
2674 | return -EINVAL; | |
2675 | ||
2676 | order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE)); | |
3c1720f0 SR |
2677 | |
2678 | /* | |
a7900875 SR |
2679 | * We want to fill as much as possible. No more than a page |
2680 | * may be empty. | |
3c1720f0 | 2681 | */ |
a7900875 SR |
2682 | while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE) |
2683 | order--; | |
3c1720f0 | 2684 | |
a7900875 SR |
2685 | again: |
2686 | pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order); | |
3c1720f0 | 2687 | |
a7900875 SR |
2688 | if (!pg->records) { |
2689 | /* if we can't allocate this size, try something smaller */ | |
2690 | if (!order) | |
2691 | return -ENOMEM; | |
2692 | order >>= 1; | |
2693 | goto again; | |
2694 | } | |
3c1720f0 | 2695 | |
a7900875 SR |
2696 | cnt = (PAGE_SIZE << order) / ENTRY_SIZE; |
2697 | pg->size = cnt; | |
3c1720f0 | 2698 | |
a7900875 SR |
2699 | if (cnt > count) |
2700 | cnt = count; | |
2701 | ||
2702 | return cnt; | |
2703 | } | |
2704 | ||
2705 | static struct ftrace_page * | |
2706 | ftrace_allocate_pages(unsigned long num_to_init) | |
2707 | { | |
2708 | struct ftrace_page *start_pg; | |
2709 | struct ftrace_page *pg; | |
2710 | int order; | |
2711 | int cnt; | |
2712 | ||
2713 | if (!num_to_init) | |
2714 | return 0; | |
2715 | ||
2716 | start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL); | |
2717 | if (!pg) | |
2718 | return NULL; | |
2719 | ||
2720 | /* | |
2721 | * Try to allocate as much as possible in one continues | |
2722 | * location that fills in all of the space. We want to | |
2723 | * waste as little space as possible. | |
2724 | */ | |
2725 | for (;;) { | |
2726 | cnt = ftrace_allocate_records(pg, num_to_init); | |
2727 | if (cnt < 0) | |
2728 | goto free_pages; | |
2729 | ||
2730 | num_to_init -= cnt; | |
2731 | if (!num_to_init) | |
3c1720f0 SR |
2732 | break; |
2733 | ||
a7900875 SR |
2734 | pg->next = kzalloc(sizeof(*pg), GFP_KERNEL); |
2735 | if (!pg->next) | |
2736 | goto free_pages; | |
2737 | ||
3c1720f0 SR |
2738 | pg = pg->next; |
2739 | } | |
2740 | ||
a7900875 SR |
2741 | return start_pg; |
2742 | ||
2743 | free_pages: | |
1f61be00 NK |
2744 | pg = start_pg; |
2745 | while (pg) { | |
a7900875 SR |
2746 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
2747 | free_pages((unsigned long)pg->records, order); | |
2748 | start_pg = pg->next; | |
2749 | kfree(pg); | |
2750 | pg = start_pg; | |
2751 | } | |
2752 | pr_info("ftrace: FAILED to allocate memory for functions\n"); | |
2753 | return NULL; | |
2754 | } | |
2755 | ||
5072c59f SR |
2756 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ |
2757 | ||
2758 | struct ftrace_iterator { | |
98c4fd04 | 2759 | loff_t pos; |
4aeb6967 SR |
2760 | loff_t func_pos; |
2761 | struct ftrace_page *pg; | |
2762 | struct dyn_ftrace *func; | |
2763 | struct ftrace_func_probe *probe; | |
2764 | struct trace_parser parser; | |
1cf41dd7 | 2765 | struct ftrace_hash *hash; |
33dc9b12 | 2766 | struct ftrace_ops *ops; |
4aeb6967 SR |
2767 | int hidx; |
2768 | int idx; | |
2769 | unsigned flags; | |
5072c59f SR |
2770 | }; |
2771 | ||
8fc0c701 | 2772 | static void * |
4aeb6967 | 2773 | t_hash_next(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
2774 | { |
2775 | struct ftrace_iterator *iter = m->private; | |
4aeb6967 | 2776 | struct hlist_node *hnd = NULL; |
8fc0c701 SR |
2777 | struct hlist_head *hhd; |
2778 | ||
8fc0c701 | 2779 | (*pos)++; |
98c4fd04 | 2780 | iter->pos = *pos; |
8fc0c701 | 2781 | |
4aeb6967 SR |
2782 | if (iter->probe) |
2783 | hnd = &iter->probe->node; | |
8fc0c701 SR |
2784 | retry: |
2785 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
2786 | return NULL; | |
2787 | ||
2788 | hhd = &ftrace_func_hash[iter->hidx]; | |
2789 | ||
2790 | if (hlist_empty(hhd)) { | |
2791 | iter->hidx++; | |
2792 | hnd = NULL; | |
2793 | goto retry; | |
2794 | } | |
2795 | ||
2796 | if (!hnd) | |
2797 | hnd = hhd->first; | |
2798 | else { | |
2799 | hnd = hnd->next; | |
2800 | if (!hnd) { | |
2801 | iter->hidx++; | |
2802 | goto retry; | |
2803 | } | |
2804 | } | |
2805 | ||
4aeb6967 SR |
2806 | if (WARN_ON_ONCE(!hnd)) |
2807 | return NULL; | |
2808 | ||
2809 | iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node); | |
2810 | ||
2811 | return iter; | |
8fc0c701 SR |
2812 | } |
2813 | ||
2814 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
2815 | { | |
2816 | struct ftrace_iterator *iter = m->private; | |
2817 | void *p = NULL; | |
d82d6244 LZ |
2818 | loff_t l; |
2819 | ||
69a3083c SR |
2820 | if (!(iter->flags & FTRACE_ITER_DO_HASH)) |
2821 | return NULL; | |
2822 | ||
2bccfffd SR |
2823 | if (iter->func_pos > *pos) |
2824 | return NULL; | |
8fc0c701 | 2825 | |
d82d6244 | 2826 | iter->hidx = 0; |
2bccfffd | 2827 | for (l = 0; l <= (*pos - iter->func_pos); ) { |
4aeb6967 | 2828 | p = t_hash_next(m, &l); |
d82d6244 LZ |
2829 | if (!p) |
2830 | break; | |
2831 | } | |
4aeb6967 SR |
2832 | if (!p) |
2833 | return NULL; | |
2834 | ||
98c4fd04 SR |
2835 | /* Only set this if we have an item */ |
2836 | iter->flags |= FTRACE_ITER_HASH; | |
2837 | ||
4aeb6967 | 2838 | return iter; |
8fc0c701 SR |
2839 | } |
2840 | ||
4aeb6967 SR |
2841 | static int |
2842 | t_hash_show(struct seq_file *m, struct ftrace_iterator *iter) | |
8fc0c701 | 2843 | { |
b6887d79 | 2844 | struct ftrace_func_probe *rec; |
8fc0c701 | 2845 | |
4aeb6967 SR |
2846 | rec = iter->probe; |
2847 | if (WARN_ON_ONCE(!rec)) | |
2848 | return -EIO; | |
8fc0c701 | 2849 | |
809dcf29 SR |
2850 | if (rec->ops->print) |
2851 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
2852 | ||
b375a11a | 2853 | seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func); |
8fc0c701 SR |
2854 | |
2855 | if (rec->data) | |
2856 | seq_printf(m, ":%p", rec->data); | |
2857 | seq_putc(m, '\n'); | |
2858 | ||
2859 | return 0; | |
2860 | } | |
2861 | ||
e309b41d | 2862 | static void * |
5072c59f SR |
2863 | t_next(struct seq_file *m, void *v, loff_t *pos) |
2864 | { | |
2865 | struct ftrace_iterator *iter = m->private; | |
fc13cb0c | 2866 | struct ftrace_ops *ops = iter->ops; |
5072c59f SR |
2867 | struct dyn_ftrace *rec = NULL; |
2868 | ||
45a4a237 SR |
2869 | if (unlikely(ftrace_disabled)) |
2870 | return NULL; | |
2871 | ||
8fc0c701 | 2872 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 2873 | return t_hash_next(m, pos); |
8fc0c701 | 2874 | |
5072c59f | 2875 | (*pos)++; |
1106b699 | 2876 | iter->pos = iter->func_pos = *pos; |
5072c59f | 2877 | |
0c75a3ed | 2878 | if (iter->flags & FTRACE_ITER_PRINTALL) |
57c072c7 | 2879 | return t_hash_start(m, pos); |
0c75a3ed | 2880 | |
5072c59f SR |
2881 | retry: |
2882 | if (iter->idx >= iter->pg->index) { | |
2883 | if (iter->pg->next) { | |
2884 | iter->pg = iter->pg->next; | |
2885 | iter->idx = 0; | |
2886 | goto retry; | |
2887 | } | |
2888 | } else { | |
2889 | rec = &iter->pg->records[iter->idx++]; | |
32082309 | 2890 | if (((iter->flags & FTRACE_ITER_FILTER) && |
33b7f99c | 2891 | !(ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))) || |
0183fb1c | 2892 | |
41c52c0d | 2893 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
33b7f99c | 2894 | !ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip)) || |
647bcd03 SR |
2895 | |
2896 | ((iter->flags & FTRACE_ITER_ENABLED) && | |
23ea9c4d | 2897 | !(rec->flags & FTRACE_FL_ENABLED))) { |
647bcd03 | 2898 | |
5072c59f SR |
2899 | rec = NULL; |
2900 | goto retry; | |
2901 | } | |
2902 | } | |
2903 | ||
4aeb6967 | 2904 | if (!rec) |
57c072c7 | 2905 | return t_hash_start(m, pos); |
4aeb6967 SR |
2906 | |
2907 | iter->func = rec; | |
2908 | ||
2909 | return iter; | |
5072c59f SR |
2910 | } |
2911 | ||
98c4fd04 SR |
2912 | static void reset_iter_read(struct ftrace_iterator *iter) |
2913 | { | |
2914 | iter->pos = 0; | |
2915 | iter->func_pos = 0; | |
70f77b3f | 2916 | iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_HASH); |
5072c59f SR |
2917 | } |
2918 | ||
2919 | static void *t_start(struct seq_file *m, loff_t *pos) | |
2920 | { | |
2921 | struct ftrace_iterator *iter = m->private; | |
fc13cb0c | 2922 | struct ftrace_ops *ops = iter->ops; |
5072c59f | 2923 | void *p = NULL; |
694ce0a5 | 2924 | loff_t l; |
5072c59f | 2925 | |
8fc0c701 | 2926 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
2927 | |
2928 | if (unlikely(ftrace_disabled)) | |
2929 | return NULL; | |
2930 | ||
98c4fd04 SR |
2931 | /* |
2932 | * If an lseek was done, then reset and start from beginning. | |
2933 | */ | |
2934 | if (*pos < iter->pos) | |
2935 | reset_iter_read(iter); | |
2936 | ||
0c75a3ed SR |
2937 | /* |
2938 | * For set_ftrace_filter reading, if we have the filter | |
2939 | * off, we can short cut and just print out that all | |
2940 | * functions are enabled. | |
2941 | */ | |
8c006cf7 | 2942 | if ((iter->flags & FTRACE_ITER_FILTER && |
33b7f99c | 2943 | ftrace_hash_empty(ops->func_hash->filter_hash)) || |
8c006cf7 | 2944 | (iter->flags & FTRACE_ITER_NOTRACE && |
33b7f99c | 2945 | ftrace_hash_empty(ops->func_hash->notrace_hash))) { |
0c75a3ed | 2946 | if (*pos > 0) |
8fc0c701 | 2947 | return t_hash_start(m, pos); |
0c75a3ed | 2948 | iter->flags |= FTRACE_ITER_PRINTALL; |
df091625 CW |
2949 | /* reset in case of seek/pread */ |
2950 | iter->flags &= ~FTRACE_ITER_HASH; | |
0c75a3ed SR |
2951 | return iter; |
2952 | } | |
2953 | ||
8fc0c701 SR |
2954 | if (iter->flags & FTRACE_ITER_HASH) |
2955 | return t_hash_start(m, pos); | |
2956 | ||
98c4fd04 SR |
2957 | /* |
2958 | * Unfortunately, we need to restart at ftrace_pages_start | |
2959 | * every time we let go of the ftrace_mutex. This is because | |
2960 | * those pointers can change without the lock. | |
2961 | */ | |
694ce0a5 LZ |
2962 | iter->pg = ftrace_pages_start; |
2963 | iter->idx = 0; | |
2964 | for (l = 0; l <= *pos; ) { | |
2965 | p = t_next(m, p, &l); | |
2966 | if (!p) | |
2967 | break; | |
50cdaf08 | 2968 | } |
5821e1b7 | 2969 | |
69a3083c SR |
2970 | if (!p) |
2971 | return t_hash_start(m, pos); | |
4aeb6967 SR |
2972 | |
2973 | return iter; | |
5072c59f SR |
2974 | } |
2975 | ||
2976 | static void t_stop(struct seq_file *m, void *p) | |
2977 | { | |
8fc0c701 | 2978 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
2979 | } |
2980 | ||
15d5b02c SRRH |
2981 | void * __weak |
2982 | arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec) | |
2983 | { | |
2984 | return NULL; | |
2985 | } | |
2986 | ||
2987 | static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops, | |
2988 | struct dyn_ftrace *rec) | |
2989 | { | |
2990 | void *ptr; | |
2991 | ||
2992 | ptr = arch_ftrace_trampoline_func(ops, rec); | |
2993 | if (ptr) | |
2994 | seq_printf(m, " ->%pS", ptr); | |
2995 | } | |
2996 | ||
5072c59f SR |
2997 | static int t_show(struct seq_file *m, void *v) |
2998 | { | |
0c75a3ed | 2999 | struct ftrace_iterator *iter = m->private; |
4aeb6967 | 3000 | struct dyn_ftrace *rec; |
5072c59f | 3001 | |
8fc0c701 | 3002 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 3003 | return t_hash_show(m, iter); |
8fc0c701 | 3004 | |
0c75a3ed | 3005 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
8c006cf7 NK |
3006 | if (iter->flags & FTRACE_ITER_NOTRACE) |
3007 | seq_printf(m, "#### no functions disabled ####\n"); | |
3008 | else | |
3009 | seq_printf(m, "#### all functions enabled ####\n"); | |
0c75a3ed SR |
3010 | return 0; |
3011 | } | |
3012 | ||
4aeb6967 SR |
3013 | rec = iter->func; |
3014 | ||
5072c59f SR |
3015 | if (!rec) |
3016 | return 0; | |
3017 | ||
647bcd03 | 3018 | seq_printf(m, "%ps", (void *)rec->ip); |
9674b2fa | 3019 | if (iter->flags & FTRACE_ITER_ENABLED) { |
15d5b02c SRRH |
3020 | struct ftrace_ops *ops = NULL; |
3021 | ||
08f6fba5 | 3022 | seq_printf(m, " (%ld)%s", |
0376bde1 | 3023 | ftrace_rec_count(rec), |
9674b2fa SRRH |
3024 | rec->flags & FTRACE_FL_REGS ? " R" : " "); |
3025 | if (rec->flags & FTRACE_FL_TRAMP_EN) { | |
5fecaa04 | 3026 | ops = ftrace_find_tramp_ops_any(rec); |
fef5aeee | 3027 | if (ops) |
9674b2fa SRRH |
3028 | seq_printf(m, "\ttramp: %pS", |
3029 | (void *)ops->trampoline); | |
3030 | else | |
3031 | seq_printf(m, "\ttramp: ERROR!"); | |
15d5b02c | 3032 | |
9674b2fa | 3033 | } |
15d5b02c | 3034 | add_trampoline_func(m, ops, rec); |
9674b2fa SRRH |
3035 | } |
3036 | ||
647bcd03 | 3037 | seq_printf(m, "\n"); |
5072c59f SR |
3038 | |
3039 | return 0; | |
3040 | } | |
3041 | ||
88e9d34c | 3042 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
3043 | .start = t_start, |
3044 | .next = t_next, | |
3045 | .stop = t_stop, | |
3046 | .show = t_show, | |
3047 | }; | |
3048 | ||
e309b41d | 3049 | static int |
5072c59f SR |
3050 | ftrace_avail_open(struct inode *inode, struct file *file) |
3051 | { | |
3052 | struct ftrace_iterator *iter; | |
5072c59f | 3053 | |
4eebcc81 SR |
3054 | if (unlikely(ftrace_disabled)) |
3055 | return -ENODEV; | |
3056 | ||
50e18b94 JO |
3057 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
3058 | if (iter) { | |
3059 | iter->pg = ftrace_pages_start; | |
3060 | iter->ops = &global_ops; | |
4bf39a94 | 3061 | } |
5072c59f | 3062 | |
50e18b94 | 3063 | return iter ? 0 : -ENOMEM; |
5072c59f SR |
3064 | } |
3065 | ||
647bcd03 SR |
3066 | static int |
3067 | ftrace_enabled_open(struct inode *inode, struct file *file) | |
3068 | { | |
3069 | struct ftrace_iterator *iter; | |
647bcd03 | 3070 | |
50e18b94 JO |
3071 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
3072 | if (iter) { | |
3073 | iter->pg = ftrace_pages_start; | |
3074 | iter->flags = FTRACE_ITER_ENABLED; | |
3075 | iter->ops = &global_ops; | |
647bcd03 SR |
3076 | } |
3077 | ||
50e18b94 | 3078 | return iter ? 0 : -ENOMEM; |
647bcd03 SR |
3079 | } |
3080 | ||
fc13cb0c SR |
3081 | /** |
3082 | * ftrace_regex_open - initialize function tracer filter files | |
3083 | * @ops: The ftrace_ops that hold the hash filters | |
3084 | * @flag: The type of filter to process | |
3085 | * @inode: The inode, usually passed in to your open routine | |
3086 | * @file: The file, usually passed in to your open routine | |
3087 | * | |
3088 | * ftrace_regex_open() initializes the filter files for the | |
3089 | * @ops. Depending on @flag it may process the filter hash or | |
3090 | * the notrace hash of @ops. With this called from the open | |
3091 | * routine, you can use ftrace_filter_write() for the write | |
3092 | * routine if @flag has FTRACE_ITER_FILTER set, or | |
3093 | * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set. | |
098c879e | 3094 | * tracing_lseek() should be used as the lseek routine, and |
fc13cb0c SR |
3095 | * release must call ftrace_regex_release(). |
3096 | */ | |
3097 | int | |
f45948e8 | 3098 | ftrace_regex_open(struct ftrace_ops *ops, int flag, |
1cf41dd7 | 3099 | struct inode *inode, struct file *file) |
5072c59f SR |
3100 | { |
3101 | struct ftrace_iterator *iter; | |
f45948e8 | 3102 | struct ftrace_hash *hash; |
5072c59f SR |
3103 | int ret = 0; |
3104 | ||
f04f24fb MH |
3105 | ftrace_ops_init(ops); |
3106 | ||
4eebcc81 SR |
3107 | if (unlikely(ftrace_disabled)) |
3108 | return -ENODEV; | |
3109 | ||
5072c59f SR |
3110 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
3111 | if (!iter) | |
3112 | return -ENOMEM; | |
3113 | ||
689fd8b6 | 3114 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) { |
3115 | kfree(iter); | |
3116 | return -ENOMEM; | |
3117 | } | |
3118 | ||
3f2367ba MH |
3119 | iter->ops = ops; |
3120 | iter->flags = flag; | |
3121 | ||
33b7f99c | 3122 | mutex_lock(&ops->func_hash->regex_lock); |
3f2367ba | 3123 | |
f45948e8 | 3124 | if (flag & FTRACE_ITER_NOTRACE) |
33b7f99c | 3125 | hash = ops->func_hash->notrace_hash; |
f45948e8 | 3126 | else |
33b7f99c | 3127 | hash = ops->func_hash->filter_hash; |
f45948e8 | 3128 | |
33dc9b12 | 3129 | if (file->f_mode & FMODE_WRITE) { |
ef2fbe16 NK |
3130 | const int size_bits = FTRACE_HASH_DEFAULT_BITS; |
3131 | ||
3132 | if (file->f_flags & O_TRUNC) | |
3133 | iter->hash = alloc_ftrace_hash(size_bits); | |
3134 | else | |
3135 | iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash); | |
3136 | ||
33dc9b12 SR |
3137 | if (!iter->hash) { |
3138 | trace_parser_put(&iter->parser); | |
3139 | kfree(iter); | |
3f2367ba MH |
3140 | ret = -ENOMEM; |
3141 | goto out_unlock; | |
33dc9b12 SR |
3142 | } |
3143 | } | |
1cf41dd7 | 3144 | |
5072c59f SR |
3145 | if (file->f_mode & FMODE_READ) { |
3146 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
3147 | |
3148 | ret = seq_open(file, &show_ftrace_seq_ops); | |
3149 | if (!ret) { | |
3150 | struct seq_file *m = file->private_data; | |
3151 | m->private = iter; | |
79fe249c | 3152 | } else { |
33dc9b12 SR |
3153 | /* Failed */ |
3154 | free_ftrace_hash(iter->hash); | |
79fe249c | 3155 | trace_parser_put(&iter->parser); |
5072c59f | 3156 | kfree(iter); |
79fe249c | 3157 | } |
5072c59f SR |
3158 | } else |
3159 | file->private_data = iter; | |
3f2367ba MH |
3160 | |
3161 | out_unlock: | |
33b7f99c | 3162 | mutex_unlock(&ops->func_hash->regex_lock); |
5072c59f SR |
3163 | |
3164 | return ret; | |
3165 | } | |
3166 | ||
41c52c0d SR |
3167 | static int |
3168 | ftrace_filter_open(struct inode *inode, struct file *file) | |
3169 | { | |
e3b3e2e8 SRRH |
3170 | struct ftrace_ops *ops = inode->i_private; |
3171 | ||
3172 | return ftrace_regex_open(ops, | |
69a3083c SR |
3173 | FTRACE_ITER_FILTER | FTRACE_ITER_DO_HASH, |
3174 | inode, file); | |
41c52c0d SR |
3175 | } |
3176 | ||
3177 | static int | |
3178 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
3179 | { | |
e3b3e2e8 SRRH |
3180 | struct ftrace_ops *ops = inode->i_private; |
3181 | ||
3182 | return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE, | |
1cf41dd7 | 3183 | inode, file); |
41c52c0d SR |
3184 | } |
3185 | ||
64e7c440 | 3186 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 3187 | { |
9f4801e3 | 3188 | int matched = 0; |
751e9983 | 3189 | int slen; |
9f4801e3 | 3190 | |
9f4801e3 SR |
3191 | switch (type) { |
3192 | case MATCH_FULL: | |
3193 | if (strcmp(str, regex) == 0) | |
3194 | matched = 1; | |
3195 | break; | |
3196 | case MATCH_FRONT_ONLY: | |
3197 | if (strncmp(str, regex, len) == 0) | |
3198 | matched = 1; | |
3199 | break; | |
3200 | case MATCH_MIDDLE_ONLY: | |
3201 | if (strstr(str, regex)) | |
3202 | matched = 1; | |
3203 | break; | |
3204 | case MATCH_END_ONLY: | |
751e9983 LZ |
3205 | slen = strlen(str); |
3206 | if (slen >= len && memcmp(str + slen - len, regex, len) == 0) | |
9f4801e3 SR |
3207 | matched = 1; |
3208 | break; | |
3209 | } | |
3210 | ||
3211 | return matched; | |
3212 | } | |
3213 | ||
b448c4e3 | 3214 | static int |
1cf41dd7 | 3215 | enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not) |
996e87be | 3216 | { |
b448c4e3 | 3217 | struct ftrace_func_entry *entry; |
b448c4e3 SR |
3218 | int ret = 0; |
3219 | ||
1cf41dd7 SR |
3220 | entry = ftrace_lookup_ip(hash, rec->ip); |
3221 | if (not) { | |
3222 | /* Do nothing if it doesn't exist */ | |
3223 | if (!entry) | |
3224 | return 0; | |
b448c4e3 | 3225 | |
33dc9b12 | 3226 | free_hash_entry(hash, entry); |
1cf41dd7 SR |
3227 | } else { |
3228 | /* Do nothing if it exists */ | |
3229 | if (entry) | |
3230 | return 0; | |
b448c4e3 | 3231 | |
1cf41dd7 | 3232 | ret = add_hash_entry(hash, rec->ip); |
b448c4e3 SR |
3233 | } |
3234 | return ret; | |
996e87be SR |
3235 | } |
3236 | ||
64e7c440 | 3237 | static int |
b9df92d2 SR |
3238 | ftrace_match_record(struct dyn_ftrace *rec, char *mod, |
3239 | char *regex, int len, int type) | |
64e7c440 SR |
3240 | { |
3241 | char str[KSYM_SYMBOL_LEN]; | |
b9df92d2 SR |
3242 | char *modname; |
3243 | ||
3244 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
3245 | ||
3246 | if (mod) { | |
3247 | /* module lookup requires matching the module */ | |
3248 | if (!modname || strcmp(modname, mod)) | |
3249 | return 0; | |
3250 | ||
3251 | /* blank search means to match all funcs in the mod */ | |
3252 | if (!len) | |
3253 | return 1; | |
3254 | } | |
64e7c440 | 3255 | |
64e7c440 SR |
3256 | return ftrace_match(str, regex, len, type); |
3257 | } | |
3258 | ||
1cf41dd7 SR |
3259 | static int |
3260 | match_records(struct ftrace_hash *hash, char *buff, | |
3261 | int len, char *mod, int not) | |
9f4801e3 | 3262 | { |
b9df92d2 | 3263 | unsigned search_len = 0; |
9f4801e3 SR |
3264 | struct ftrace_page *pg; |
3265 | struct dyn_ftrace *rec; | |
b9df92d2 SR |
3266 | int type = MATCH_FULL; |
3267 | char *search = buff; | |
311d16da | 3268 | int found = 0; |
b448c4e3 | 3269 | int ret; |
9f4801e3 | 3270 | |
b9df92d2 SR |
3271 | if (len) { |
3272 | type = filter_parse_regex(buff, len, &search, ¬); | |
3273 | search_len = strlen(search); | |
3274 | } | |
9f4801e3 | 3275 | |
52baf119 | 3276 | mutex_lock(&ftrace_lock); |
265c831c | 3277 | |
b9df92d2 SR |
3278 | if (unlikely(ftrace_disabled)) |
3279 | goto out_unlock; | |
9f4801e3 | 3280 | |
265c831c | 3281 | do_for_each_ftrace_rec(pg, rec) { |
b9df92d2 | 3282 | if (ftrace_match_record(rec, mod, search, search_len, type)) { |
1cf41dd7 | 3283 | ret = enter_record(hash, rec, not); |
b448c4e3 SR |
3284 | if (ret < 0) { |
3285 | found = ret; | |
3286 | goto out_unlock; | |
3287 | } | |
311d16da | 3288 | found = 1; |
265c831c SR |
3289 | } |
3290 | } while_for_each_ftrace_rec(); | |
b9df92d2 | 3291 | out_unlock: |
52baf119 | 3292 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
3293 | |
3294 | return found; | |
5072c59f SR |
3295 | } |
3296 | ||
64e7c440 | 3297 | static int |
1cf41dd7 | 3298 | ftrace_match_records(struct ftrace_hash *hash, char *buff, int len) |
64e7c440 | 3299 | { |
1cf41dd7 | 3300 | return match_records(hash, buff, len, NULL, 0); |
64e7c440 SR |
3301 | } |
3302 | ||
1cf41dd7 SR |
3303 | static int |
3304 | ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod) | |
64e7c440 | 3305 | { |
64e7c440 | 3306 | int not = 0; |
6a24a244 | 3307 | |
64e7c440 SR |
3308 | /* blank or '*' mean the same */ |
3309 | if (strcmp(buff, "*") == 0) | |
3310 | buff[0] = 0; | |
3311 | ||
3312 | /* handle the case of 'dont filter this module' */ | |
3313 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
3314 | buff[0] = 0; | |
3315 | not = 1; | |
3316 | } | |
3317 | ||
1cf41dd7 | 3318 | return match_records(hash, buff, strlen(buff), mod, not); |
64e7c440 SR |
3319 | } |
3320 | ||
f6180773 SR |
3321 | /* |
3322 | * We register the module command as a template to show others how | |
3323 | * to register the a command as well. | |
3324 | */ | |
3325 | ||
3326 | static int | |
43dd61c9 SR |
3327 | ftrace_mod_callback(struct ftrace_hash *hash, |
3328 | char *func, char *cmd, char *param, int enable) | |
f6180773 SR |
3329 | { |
3330 | char *mod; | |
b448c4e3 | 3331 | int ret = -EINVAL; |
f6180773 SR |
3332 | |
3333 | /* | |
3334 | * cmd == 'mod' because we only registered this func | |
3335 | * for the 'mod' ftrace_func_command. | |
3336 | * But if you register one func with multiple commands, | |
3337 | * you can tell which command was used by the cmd | |
3338 | * parameter. | |
3339 | */ | |
3340 | ||
3341 | /* we must have a module name */ | |
3342 | if (!param) | |
b448c4e3 | 3343 | return ret; |
f6180773 SR |
3344 | |
3345 | mod = strsep(¶m, ":"); | |
3346 | if (!strlen(mod)) | |
b448c4e3 | 3347 | return ret; |
f6180773 | 3348 | |
1cf41dd7 | 3349 | ret = ftrace_match_module_records(hash, func, mod); |
b448c4e3 SR |
3350 | if (!ret) |
3351 | ret = -EINVAL; | |
3352 | if (ret < 0) | |
3353 | return ret; | |
3354 | ||
3355 | return 0; | |
f6180773 SR |
3356 | } |
3357 | ||
3358 | static struct ftrace_func_command ftrace_mod_cmd = { | |
3359 | .name = "mod", | |
3360 | .func = ftrace_mod_callback, | |
3361 | }; | |
3362 | ||
3363 | static int __init ftrace_mod_cmd_init(void) | |
3364 | { | |
3365 | return register_ftrace_command(&ftrace_mod_cmd); | |
3366 | } | |
6f415672 | 3367 | core_initcall(ftrace_mod_cmd_init); |
f6180773 | 3368 | |
2f5f6ad9 | 3369 | static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 3370 | struct ftrace_ops *op, struct pt_regs *pt_regs) |
59df055f | 3371 | { |
b6887d79 | 3372 | struct ftrace_func_probe *entry; |
59df055f | 3373 | struct hlist_head *hhd; |
59df055f | 3374 | unsigned long key; |
59df055f SR |
3375 | |
3376 | key = hash_long(ip, FTRACE_HASH_BITS); | |
3377 | ||
3378 | hhd = &ftrace_func_hash[key]; | |
3379 | ||
3380 | if (hlist_empty(hhd)) | |
3381 | return; | |
3382 | ||
3383 | /* | |
3384 | * Disable preemption for these calls to prevent a RCU grace | |
3385 | * period. This syncs the hash iteration and freeing of items | |
3386 | * on the hash. rcu_read_lock is too dangerous here. | |
3387 | */ | |
5168ae50 | 3388 | preempt_disable_notrace(); |
1bb539ca | 3389 | hlist_for_each_entry_rcu_notrace(entry, hhd, node) { |
59df055f SR |
3390 | if (entry->ip == ip) |
3391 | entry->ops->func(ip, parent_ip, &entry->data); | |
3392 | } | |
5168ae50 | 3393 | preempt_enable_notrace(); |
59df055f SR |
3394 | } |
3395 | ||
b6887d79 | 3396 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 3397 | { |
fb9fb015 | 3398 | .func = function_trace_probe_call, |
f04f24fb | 3399 | .flags = FTRACE_OPS_FL_INITIALIZED, |
33b7f99c | 3400 | INIT_OPS_HASH(trace_probe_ops) |
59df055f SR |
3401 | }; |
3402 | ||
b6887d79 | 3403 | static int ftrace_probe_registered; |
59df055f | 3404 | |
8252ecf3 | 3405 | static void __enable_ftrace_function_probe(struct ftrace_hash *old_hash) |
59df055f | 3406 | { |
b848914c | 3407 | int ret; |
59df055f SR |
3408 | int i; |
3409 | ||
19dd603e SRRH |
3410 | if (ftrace_probe_registered) { |
3411 | /* still need to update the function call sites */ | |
3412 | if (ftrace_enabled) | |
8252ecf3 SRRH |
3413 | ftrace_run_modify_code(&trace_probe_ops, FTRACE_UPDATE_CALLS, |
3414 | old_hash); | |
59df055f | 3415 | return; |
19dd603e | 3416 | } |
59df055f SR |
3417 | |
3418 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
3419 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
3420 | if (hhd->first) | |
3421 | break; | |
3422 | } | |
3423 | /* Nothing registered? */ | |
3424 | if (i == FTRACE_FUNC_HASHSIZE) | |
3425 | return; | |
3426 | ||
8a56d776 | 3427 | ret = ftrace_startup(&trace_probe_ops, 0); |
b848914c | 3428 | |
b6887d79 | 3429 | ftrace_probe_registered = 1; |
59df055f SR |
3430 | } |
3431 | ||
b6887d79 | 3432 | static void __disable_ftrace_function_probe(void) |
59df055f SR |
3433 | { |
3434 | int i; | |
3435 | ||
b6887d79 | 3436 | if (!ftrace_probe_registered) |
59df055f SR |
3437 | return; |
3438 | ||
3439 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
3440 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
3441 | if (hhd->first) | |
3442 | return; | |
3443 | } | |
3444 | ||
3445 | /* no more funcs left */ | |
8a56d776 | 3446 | ftrace_shutdown(&trace_probe_ops, 0); |
b848914c | 3447 | |
b6887d79 | 3448 | ftrace_probe_registered = 0; |
59df055f SR |
3449 | } |
3450 | ||
3451 | ||
7818b388 | 3452 | static void ftrace_free_entry(struct ftrace_func_probe *entry) |
59df055f | 3453 | { |
59df055f | 3454 | if (entry->ops->free) |
e67efb93 | 3455 | entry->ops->free(entry->ops, entry->ip, &entry->data); |
59df055f SR |
3456 | kfree(entry); |
3457 | } | |
3458 | ||
59df055f | 3459 | int |
b6887d79 | 3460 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3461 | void *data) |
3462 | { | |
b6887d79 | 3463 | struct ftrace_func_probe *entry; |
33b7f99c | 3464 | struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash; |
3296fc4e | 3465 | struct ftrace_hash *old_hash = *orig_hash; |
e1df4cb6 | 3466 | struct ftrace_hash *hash; |
59df055f SR |
3467 | struct ftrace_page *pg; |
3468 | struct dyn_ftrace *rec; | |
59df055f | 3469 | int type, len, not; |
6a24a244 | 3470 | unsigned long key; |
59df055f SR |
3471 | int count = 0; |
3472 | char *search; | |
e1df4cb6 | 3473 | int ret; |
59df055f | 3474 | |
3f6fe06d | 3475 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
3476 | len = strlen(search); |
3477 | ||
b6887d79 | 3478 | /* we do not support '!' for function probes */ |
59df055f SR |
3479 | if (WARN_ON(not)) |
3480 | return -EINVAL; | |
3481 | ||
33b7f99c | 3482 | mutex_lock(&trace_probe_ops.func_hash->regex_lock); |
59df055f | 3483 | |
3296fc4e | 3484 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); |
e1df4cb6 SRRH |
3485 | if (!hash) { |
3486 | count = -ENOMEM; | |
5ae0bf59 | 3487 | goto out; |
e1df4cb6 SRRH |
3488 | } |
3489 | ||
3490 | if (unlikely(ftrace_disabled)) { | |
3491 | count = -ENODEV; | |
5ae0bf59 | 3492 | goto out; |
e1df4cb6 | 3493 | } |
59df055f | 3494 | |
5ae0bf59 SRRH |
3495 | mutex_lock(&ftrace_lock); |
3496 | ||
45a4a237 | 3497 | do_for_each_ftrace_rec(pg, rec) { |
59df055f | 3498 | |
b9df92d2 | 3499 | if (!ftrace_match_record(rec, NULL, search, len, type)) |
59df055f SR |
3500 | continue; |
3501 | ||
3502 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
3503 | if (!entry) { | |
b6887d79 | 3504 | /* If we did not process any, then return error */ |
59df055f SR |
3505 | if (!count) |
3506 | count = -ENOMEM; | |
3507 | goto out_unlock; | |
3508 | } | |
3509 | ||
3510 | count++; | |
3511 | ||
3512 | entry->data = data; | |
3513 | ||
3514 | /* | |
3515 | * The caller might want to do something special | |
3516 | * for each function we find. We call the callback | |
3517 | * to give the caller an opportunity to do so. | |
3518 | */ | |
e67efb93 SRRH |
3519 | if (ops->init) { |
3520 | if (ops->init(ops, rec->ip, &entry->data) < 0) { | |
59df055f SR |
3521 | /* caller does not like this func */ |
3522 | kfree(entry); | |
3523 | continue; | |
3524 | } | |
3525 | } | |
3526 | ||
e1df4cb6 SRRH |
3527 | ret = enter_record(hash, rec, 0); |
3528 | if (ret < 0) { | |
3529 | kfree(entry); | |
3530 | count = ret; | |
3531 | goto out_unlock; | |
3532 | } | |
3533 | ||
59df055f SR |
3534 | entry->ops = ops; |
3535 | entry->ip = rec->ip; | |
3536 | ||
3537 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
3538 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
3539 | ||
3540 | } while_for_each_ftrace_rec(); | |
e1df4cb6 SRRH |
3541 | |
3542 | ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash); | |
8252ecf3 SRRH |
3543 | |
3544 | __enable_ftrace_function_probe(old_hash); | |
3545 | ||
3296fc4e SRRH |
3546 | if (!ret) |
3547 | free_ftrace_hash_rcu(old_hash); | |
3548 | else | |
e1df4cb6 SRRH |
3549 | count = ret; |
3550 | ||
59df055f | 3551 | out_unlock: |
5ae0bf59 SRRH |
3552 | mutex_unlock(&ftrace_lock); |
3553 | out: | |
33b7f99c | 3554 | mutex_unlock(&trace_probe_ops.func_hash->regex_lock); |
e1df4cb6 | 3555 | free_ftrace_hash(hash); |
59df055f SR |
3556 | |
3557 | return count; | |
3558 | } | |
3559 | ||
3560 | enum { | |
b6887d79 SR |
3561 | PROBE_TEST_FUNC = 1, |
3562 | PROBE_TEST_DATA = 2 | |
59df055f SR |
3563 | }; |
3564 | ||
3565 | static void | |
b6887d79 | 3566 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3567 | void *data, int flags) |
3568 | { | |
e1df4cb6 | 3569 | struct ftrace_func_entry *rec_entry; |
b6887d79 | 3570 | struct ftrace_func_probe *entry; |
7818b388 | 3571 | struct ftrace_func_probe *p; |
33b7f99c | 3572 | struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash; |
3296fc4e | 3573 | struct ftrace_hash *old_hash = *orig_hash; |
7818b388 | 3574 | struct list_head free_list; |
e1df4cb6 | 3575 | struct ftrace_hash *hash; |
b67bfe0d | 3576 | struct hlist_node *tmp; |
59df055f SR |
3577 | char str[KSYM_SYMBOL_LEN]; |
3578 | int type = MATCH_FULL; | |
3579 | int i, len = 0; | |
3580 | char *search; | |
3296fc4e | 3581 | int ret; |
59df055f | 3582 | |
b36461da | 3583 | if (glob && (strcmp(glob, "*") == 0 || !strlen(glob))) |
59df055f | 3584 | glob = NULL; |
b36461da | 3585 | else if (glob) { |
59df055f SR |
3586 | int not; |
3587 | ||
3f6fe06d | 3588 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
3589 | len = strlen(search); |
3590 | ||
b6887d79 | 3591 | /* we do not support '!' for function probes */ |
59df055f SR |
3592 | if (WARN_ON(not)) |
3593 | return; | |
3594 | } | |
3595 | ||
33b7f99c | 3596 | mutex_lock(&trace_probe_ops.func_hash->regex_lock); |
e1df4cb6 SRRH |
3597 | |
3598 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
3599 | if (!hash) | |
3600 | /* Hmm, should report this somehow */ | |
3601 | goto out_unlock; | |
3602 | ||
7818b388 SRRH |
3603 | INIT_LIST_HEAD(&free_list); |
3604 | ||
59df055f SR |
3605 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { |
3606 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
3607 | ||
b67bfe0d | 3608 | hlist_for_each_entry_safe(entry, tmp, hhd, node) { |
59df055f SR |
3609 | |
3610 | /* break up if statements for readability */ | |
b6887d79 | 3611 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
3612 | continue; |
3613 | ||
b6887d79 | 3614 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
3615 | continue; |
3616 | ||
3617 | /* do this last, since it is the most expensive */ | |
3618 | if (glob) { | |
3619 | kallsyms_lookup(entry->ip, NULL, NULL, | |
3620 | NULL, str); | |
3621 | if (!ftrace_match(str, glob, len, type)) | |
3622 | continue; | |
3623 | } | |
3624 | ||
e1df4cb6 SRRH |
3625 | rec_entry = ftrace_lookup_ip(hash, entry->ip); |
3626 | /* It is possible more than one entry had this ip */ | |
3627 | if (rec_entry) | |
3628 | free_hash_entry(hash, rec_entry); | |
3629 | ||
740466bc | 3630 | hlist_del_rcu(&entry->node); |
7818b388 | 3631 | list_add(&entry->free_list, &free_list); |
59df055f SR |
3632 | } |
3633 | } | |
3f2367ba | 3634 | mutex_lock(&ftrace_lock); |
b6887d79 | 3635 | __disable_ftrace_function_probe(); |
e1df4cb6 SRRH |
3636 | /* |
3637 | * Remove after the disable is called. Otherwise, if the last | |
3638 | * probe is removed, a null hash means *all enabled*. | |
3639 | */ | |
3296fc4e | 3640 | ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash); |
7818b388 | 3641 | synchronize_sched(); |
3296fc4e SRRH |
3642 | if (!ret) |
3643 | free_ftrace_hash_rcu(old_hash); | |
3644 | ||
7818b388 SRRH |
3645 | list_for_each_entry_safe(entry, p, &free_list, free_list) { |
3646 | list_del(&entry->free_list); | |
3647 | ftrace_free_entry(entry); | |
3648 | } | |
3f2367ba | 3649 | mutex_unlock(&ftrace_lock); |
7818b388 | 3650 | |
e1df4cb6 | 3651 | out_unlock: |
33b7f99c | 3652 | mutex_unlock(&trace_probe_ops.func_hash->regex_lock); |
e1df4cb6 | 3653 | free_ftrace_hash(hash); |
59df055f SR |
3654 | } |
3655 | ||
3656 | void | |
b6887d79 | 3657 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3658 | void *data) |
3659 | { | |
b6887d79 SR |
3660 | __unregister_ftrace_function_probe(glob, ops, data, |
3661 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
3662 | } |
3663 | ||
3664 | void | |
b6887d79 | 3665 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 3666 | { |
b6887d79 | 3667 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
3668 | } |
3669 | ||
b6887d79 | 3670 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 3671 | { |
b6887d79 | 3672 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
3673 | } |
3674 | ||
f6180773 SR |
3675 | static LIST_HEAD(ftrace_commands); |
3676 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
3677 | ||
38de93ab TZ |
3678 | /* |
3679 | * Currently we only register ftrace commands from __init, so mark this | |
3680 | * __init too. | |
3681 | */ | |
3682 | __init int register_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
3683 | { |
3684 | struct ftrace_func_command *p; | |
3685 | int ret = 0; | |
3686 | ||
3687 | mutex_lock(&ftrace_cmd_mutex); | |
3688 | list_for_each_entry(p, &ftrace_commands, list) { | |
3689 | if (strcmp(cmd->name, p->name) == 0) { | |
3690 | ret = -EBUSY; | |
3691 | goto out_unlock; | |
3692 | } | |
3693 | } | |
3694 | list_add(&cmd->list, &ftrace_commands); | |
3695 | out_unlock: | |
3696 | mutex_unlock(&ftrace_cmd_mutex); | |
3697 | ||
3698 | return ret; | |
3699 | } | |
3700 | ||
38de93ab TZ |
3701 | /* |
3702 | * Currently we only unregister ftrace commands from __init, so mark | |
3703 | * this __init too. | |
3704 | */ | |
3705 | __init int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
3706 | { |
3707 | struct ftrace_func_command *p, *n; | |
3708 | int ret = -ENODEV; | |
3709 | ||
3710 | mutex_lock(&ftrace_cmd_mutex); | |
3711 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
3712 | if (strcmp(cmd->name, p->name) == 0) { | |
3713 | ret = 0; | |
3714 | list_del_init(&p->list); | |
3715 | goto out_unlock; | |
3716 | } | |
3717 | } | |
3718 | out_unlock: | |
3719 | mutex_unlock(&ftrace_cmd_mutex); | |
3720 | ||
3721 | return ret; | |
3722 | } | |
3723 | ||
33dc9b12 SR |
3724 | static int ftrace_process_regex(struct ftrace_hash *hash, |
3725 | char *buff, int len, int enable) | |
64e7c440 | 3726 | { |
f6180773 | 3727 | char *func, *command, *next = buff; |
6a24a244 | 3728 | struct ftrace_func_command *p; |
0aff1c0c | 3729 | int ret = -EINVAL; |
64e7c440 SR |
3730 | |
3731 | func = strsep(&next, ":"); | |
3732 | ||
3733 | if (!next) { | |
1cf41dd7 | 3734 | ret = ftrace_match_records(hash, func, len); |
b448c4e3 SR |
3735 | if (!ret) |
3736 | ret = -EINVAL; | |
3737 | if (ret < 0) | |
3738 | return ret; | |
3739 | return 0; | |
64e7c440 SR |
3740 | } |
3741 | ||
f6180773 | 3742 | /* command found */ |
64e7c440 SR |
3743 | |
3744 | command = strsep(&next, ":"); | |
3745 | ||
f6180773 SR |
3746 | mutex_lock(&ftrace_cmd_mutex); |
3747 | list_for_each_entry(p, &ftrace_commands, list) { | |
3748 | if (strcmp(p->name, command) == 0) { | |
43dd61c9 | 3749 | ret = p->func(hash, func, command, next, enable); |
f6180773 SR |
3750 | goto out_unlock; |
3751 | } | |
64e7c440 | 3752 | } |
f6180773 SR |
3753 | out_unlock: |
3754 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 3755 | |
f6180773 | 3756 | return ret; |
64e7c440 SR |
3757 | } |
3758 | ||
e309b41d | 3759 | static ssize_t |
41c52c0d SR |
3760 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
3761 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
3762 | { |
3763 | struct ftrace_iterator *iter; | |
689fd8b6 | 3764 | struct trace_parser *parser; |
3765 | ssize_t ret, read; | |
5072c59f | 3766 | |
4ba7978e | 3767 | if (!cnt) |
5072c59f SR |
3768 | return 0; |
3769 | ||
5072c59f SR |
3770 | if (file->f_mode & FMODE_READ) { |
3771 | struct seq_file *m = file->private_data; | |
3772 | iter = m->private; | |
3773 | } else | |
3774 | iter = file->private_data; | |
3775 | ||
f04f24fb | 3776 | if (unlikely(ftrace_disabled)) |
3f2367ba MH |
3777 | return -ENODEV; |
3778 | ||
3779 | /* iter->hash is a local copy, so we don't need regex_lock */ | |
f04f24fb | 3780 | |
689fd8b6 | 3781 | parser = &iter->parser; |
3782 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 3783 | |
4ba7978e | 3784 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 3785 | !trace_parser_cont(parser)) { |
33dc9b12 | 3786 | ret = ftrace_process_regex(iter->hash, parser->buffer, |
689fd8b6 | 3787 | parser->idx, enable); |
313254a9 | 3788 | trace_parser_clear(parser); |
7c088b51 | 3789 | if (ret < 0) |
3f2367ba | 3790 | goto out; |
eda1e328 | 3791 | } |
5072c59f | 3792 | |
5072c59f | 3793 | ret = read; |
3f2367ba | 3794 | out: |
5072c59f SR |
3795 | return ret; |
3796 | } | |
3797 | ||
fc13cb0c | 3798 | ssize_t |
41c52c0d SR |
3799 | ftrace_filter_write(struct file *file, const char __user *ubuf, |
3800 | size_t cnt, loff_t *ppos) | |
3801 | { | |
3802 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
3803 | } | |
3804 | ||
fc13cb0c | 3805 | ssize_t |
41c52c0d SR |
3806 | ftrace_notrace_write(struct file *file, const char __user *ubuf, |
3807 | size_t cnt, loff_t *ppos) | |
3808 | { | |
3809 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
3810 | } | |
3811 | ||
33dc9b12 | 3812 | static int |
647664ea MH |
3813 | ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) |
3814 | { | |
3815 | struct ftrace_func_entry *entry; | |
3816 | ||
3817 | if (!ftrace_location(ip)) | |
3818 | return -EINVAL; | |
3819 | ||
3820 | if (remove) { | |
3821 | entry = ftrace_lookup_ip(hash, ip); | |
3822 | if (!entry) | |
3823 | return -ENOENT; | |
3824 | free_hash_entry(hash, entry); | |
3825 | return 0; | |
3826 | } | |
3827 | ||
3828 | return add_hash_entry(hash, ip); | |
3829 | } | |
3830 | ||
8252ecf3 SRRH |
3831 | static void ftrace_ops_update_code(struct ftrace_ops *ops, |
3832 | struct ftrace_hash *old_hash) | |
1c80c432 SRRH |
3833 | { |
3834 | if (ops->flags & FTRACE_OPS_FL_ENABLED && ftrace_enabled) | |
8252ecf3 | 3835 | ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash); |
1c80c432 SRRH |
3836 | } |
3837 | ||
647664ea MH |
3838 | static int |
3839 | ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, | |
3840 | unsigned long ip, int remove, int reset, int enable) | |
41c52c0d | 3841 | { |
33dc9b12 | 3842 | struct ftrace_hash **orig_hash; |
3296fc4e | 3843 | struct ftrace_hash *old_hash; |
f45948e8 | 3844 | struct ftrace_hash *hash; |
33dc9b12 | 3845 | int ret; |
f45948e8 | 3846 | |
41c52c0d | 3847 | if (unlikely(ftrace_disabled)) |
33dc9b12 | 3848 | return -ENODEV; |
41c52c0d | 3849 | |
33b7f99c | 3850 | mutex_lock(&ops->func_hash->regex_lock); |
3f2367ba | 3851 | |
f45948e8 | 3852 | if (enable) |
33b7f99c | 3853 | orig_hash = &ops->func_hash->filter_hash; |
f45948e8 | 3854 | else |
33b7f99c | 3855 | orig_hash = &ops->func_hash->notrace_hash; |
33dc9b12 | 3856 | |
b972cc58 WN |
3857 | if (reset) |
3858 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); | |
3859 | else | |
3860 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
3861 | ||
3f2367ba MH |
3862 | if (!hash) { |
3863 | ret = -ENOMEM; | |
3864 | goto out_regex_unlock; | |
3865 | } | |
f45948e8 | 3866 | |
ac483c44 JO |
3867 | if (buf && !ftrace_match_records(hash, buf, len)) { |
3868 | ret = -EINVAL; | |
3869 | goto out_regex_unlock; | |
3870 | } | |
647664ea MH |
3871 | if (ip) { |
3872 | ret = ftrace_match_addr(hash, ip, remove); | |
3873 | if (ret < 0) | |
3874 | goto out_regex_unlock; | |
3875 | } | |
33dc9b12 SR |
3876 | |
3877 | mutex_lock(&ftrace_lock); | |
3296fc4e | 3878 | old_hash = *orig_hash; |
41fb61c2 | 3879 | ret = ftrace_hash_move(ops, enable, orig_hash, hash); |
3296fc4e | 3880 | if (!ret) { |
8252ecf3 | 3881 | ftrace_ops_update_code(ops, old_hash); |
3296fc4e SRRH |
3882 | free_ftrace_hash_rcu(old_hash); |
3883 | } | |
33dc9b12 SR |
3884 | mutex_unlock(&ftrace_lock); |
3885 | ||
ac483c44 | 3886 | out_regex_unlock: |
33b7f99c | 3887 | mutex_unlock(&ops->func_hash->regex_lock); |
33dc9b12 SR |
3888 | |
3889 | free_ftrace_hash(hash); | |
3890 | return ret; | |
41c52c0d SR |
3891 | } |
3892 | ||
647664ea MH |
3893 | static int |
3894 | ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove, | |
3895 | int reset, int enable) | |
3896 | { | |
3897 | return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable); | |
3898 | } | |
3899 | ||
3900 | /** | |
3901 | * ftrace_set_filter_ip - set a function to filter on in ftrace by address | |
3902 | * @ops - the ops to set the filter with | |
3903 | * @ip - the address to add to or remove from the filter. | |
3904 | * @remove - non zero to remove the ip from the filter | |
3905 | * @reset - non zero to reset all filters before applying this filter. | |
3906 | * | |
3907 | * Filters denote which functions should be enabled when tracing is enabled | |
3908 | * If @ip is NULL, it failes to update filter. | |
3909 | */ | |
3910 | int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, | |
3911 | int remove, int reset) | |
3912 | { | |
f04f24fb | 3913 | ftrace_ops_init(ops); |
647664ea MH |
3914 | return ftrace_set_addr(ops, ip, remove, reset, 1); |
3915 | } | |
3916 | EXPORT_SYMBOL_GPL(ftrace_set_filter_ip); | |
3917 | ||
3918 | static int | |
3919 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, | |
3920 | int reset, int enable) | |
3921 | { | |
3922 | return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable); | |
3923 | } | |
3924 | ||
77a2b37d SR |
3925 | /** |
3926 | * ftrace_set_filter - set a function to filter on in ftrace | |
936e074b SR |
3927 | * @ops - the ops to set the filter with |
3928 | * @buf - the string that holds the function filter text. | |
3929 | * @len - the length of the string. | |
3930 | * @reset - non zero to reset all filters before applying this filter. | |
3931 | * | |
3932 | * Filters denote which functions should be enabled when tracing is enabled. | |
3933 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
3934 | */ | |
ac483c44 | 3935 | int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
3936 | int len, int reset) |
3937 | { | |
f04f24fb | 3938 | ftrace_ops_init(ops); |
ac483c44 | 3939 | return ftrace_set_regex(ops, buf, len, reset, 1); |
936e074b SR |
3940 | } |
3941 | EXPORT_SYMBOL_GPL(ftrace_set_filter); | |
3942 | ||
3943 | /** | |
3944 | * ftrace_set_notrace - set a function to not trace in ftrace | |
3945 | * @ops - the ops to set the notrace filter with | |
3946 | * @buf - the string that holds the function notrace text. | |
3947 | * @len - the length of the string. | |
3948 | * @reset - non zero to reset all filters before applying this filter. | |
3949 | * | |
3950 | * Notrace Filters denote which functions should not be enabled when tracing | |
3951 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
3952 | * for tracing. | |
3953 | */ | |
ac483c44 | 3954 | int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
3955 | int len, int reset) |
3956 | { | |
f04f24fb | 3957 | ftrace_ops_init(ops); |
ac483c44 | 3958 | return ftrace_set_regex(ops, buf, len, reset, 0); |
936e074b SR |
3959 | } |
3960 | EXPORT_SYMBOL_GPL(ftrace_set_notrace); | |
3961 | /** | |
8d1b065d | 3962 | * ftrace_set_global_filter - set a function to filter on with global tracers |
77a2b37d SR |
3963 | * @buf - the string that holds the function filter text. |
3964 | * @len - the length of the string. | |
3965 | * @reset - non zero to reset all filters before applying this filter. | |
3966 | * | |
3967 | * Filters denote which functions should be enabled when tracing is enabled. | |
3968 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
3969 | */ | |
936e074b | 3970 | void ftrace_set_global_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 3971 | { |
f45948e8 | 3972 | ftrace_set_regex(&global_ops, buf, len, reset, 1); |
41c52c0d | 3973 | } |
936e074b | 3974 | EXPORT_SYMBOL_GPL(ftrace_set_global_filter); |
4eebcc81 | 3975 | |
41c52c0d | 3976 | /** |
8d1b065d | 3977 | * ftrace_set_global_notrace - set a function to not trace with global tracers |
41c52c0d SR |
3978 | * @buf - the string that holds the function notrace text. |
3979 | * @len - the length of the string. | |
3980 | * @reset - non zero to reset all filters before applying this filter. | |
3981 | * | |
3982 | * Notrace Filters denote which functions should not be enabled when tracing | |
3983 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
3984 | * for tracing. | |
3985 | */ | |
936e074b | 3986 | void ftrace_set_global_notrace(unsigned char *buf, int len, int reset) |
41c52c0d | 3987 | { |
f45948e8 | 3988 | ftrace_set_regex(&global_ops, buf, len, reset, 0); |
77a2b37d | 3989 | } |
936e074b | 3990 | EXPORT_SYMBOL_GPL(ftrace_set_global_notrace); |
77a2b37d | 3991 | |
2af15d6a SR |
3992 | /* |
3993 | * command line interface to allow users to set filters on boot up. | |
3994 | */ | |
3995 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
3996 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
3997 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
3998 | ||
f1ed7c74 SRRH |
3999 | /* Used by function selftest to not test if filter is set */ |
4000 | bool ftrace_filter_param __initdata; | |
4001 | ||
2af15d6a SR |
4002 | static int __init set_ftrace_notrace(char *str) |
4003 | { | |
f1ed7c74 | 4004 | ftrace_filter_param = true; |
75761cc1 | 4005 | strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
4006 | return 1; |
4007 | } | |
4008 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
4009 | ||
4010 | static int __init set_ftrace_filter(char *str) | |
4011 | { | |
f1ed7c74 | 4012 | ftrace_filter_param = true; |
75761cc1 | 4013 | strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
4014 | return 1; |
4015 | } | |
4016 | __setup("ftrace_filter=", set_ftrace_filter); | |
4017 | ||
369bc18f | 4018 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 4019 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
0d7d9a16 | 4020 | static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata; |
faf982a6 | 4021 | static int ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer); |
801c29fd | 4022 | |
f3bea491 SRRH |
4023 | static unsigned long save_global_trampoline; |
4024 | static unsigned long save_global_flags; | |
4025 | ||
369bc18f SA |
4026 | static int __init set_graph_function(char *str) |
4027 | { | |
06f43d66 | 4028 | strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
4029 | return 1; |
4030 | } | |
4031 | __setup("ftrace_graph_filter=", set_graph_function); | |
4032 | ||
0d7d9a16 NK |
4033 | static int __init set_graph_notrace_function(char *str) |
4034 | { | |
4035 | strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE); | |
4036 | return 1; | |
4037 | } | |
4038 | __setup("ftrace_graph_notrace=", set_graph_notrace_function); | |
4039 | ||
4040 | static void __init set_ftrace_early_graph(char *buf, int enable) | |
369bc18f SA |
4041 | { |
4042 | int ret; | |
4043 | char *func; | |
0d7d9a16 NK |
4044 | unsigned long *table = ftrace_graph_funcs; |
4045 | int *count = &ftrace_graph_count; | |
4046 | ||
4047 | if (!enable) { | |
4048 | table = ftrace_graph_notrace_funcs; | |
4049 | count = &ftrace_graph_notrace_count; | |
4050 | } | |
369bc18f SA |
4051 | |
4052 | while (buf) { | |
4053 | func = strsep(&buf, ","); | |
4054 | /* we allow only one expression at a time */ | |
0d7d9a16 | 4055 | ret = ftrace_set_func(table, count, FTRACE_GRAPH_MAX_FUNCS, func); |
369bc18f SA |
4056 | if (ret) |
4057 | printk(KERN_DEBUG "ftrace: function %s not " | |
4058 | "traceable\n", func); | |
4059 | } | |
4060 | } | |
4061 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
4062 | ||
2a85a37f SR |
4063 | void __init |
4064 | ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable) | |
2af15d6a SR |
4065 | { |
4066 | char *func; | |
4067 | ||
f04f24fb MH |
4068 | ftrace_ops_init(ops); |
4069 | ||
2af15d6a SR |
4070 | while (buf) { |
4071 | func = strsep(&buf, ","); | |
f45948e8 | 4072 | ftrace_set_regex(ops, func, strlen(func), 0, enable); |
2af15d6a SR |
4073 | } |
4074 | } | |
4075 | ||
4076 | static void __init set_ftrace_early_filters(void) | |
4077 | { | |
4078 | if (ftrace_filter_buf[0]) | |
2a85a37f | 4079 | ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1); |
2af15d6a | 4080 | if (ftrace_notrace_buf[0]) |
2a85a37f | 4081 | ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0); |
369bc18f SA |
4082 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
4083 | if (ftrace_graph_buf[0]) | |
0d7d9a16 NK |
4084 | set_ftrace_early_graph(ftrace_graph_buf, 1); |
4085 | if (ftrace_graph_notrace_buf[0]) | |
4086 | set_ftrace_early_graph(ftrace_graph_notrace_buf, 0); | |
369bc18f | 4087 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
2af15d6a SR |
4088 | } |
4089 | ||
fc13cb0c | 4090 | int ftrace_regex_release(struct inode *inode, struct file *file) |
5072c59f SR |
4091 | { |
4092 | struct seq_file *m = (struct seq_file *)file->private_data; | |
4093 | struct ftrace_iterator *iter; | |
33dc9b12 | 4094 | struct ftrace_hash **orig_hash; |
3296fc4e | 4095 | struct ftrace_hash *old_hash; |
689fd8b6 | 4096 | struct trace_parser *parser; |
ed926f9b | 4097 | int filter_hash; |
33dc9b12 | 4098 | int ret; |
5072c59f | 4099 | |
5072c59f SR |
4100 | if (file->f_mode & FMODE_READ) { |
4101 | iter = m->private; | |
5072c59f SR |
4102 | seq_release(inode, file); |
4103 | } else | |
4104 | iter = file->private_data; | |
4105 | ||
689fd8b6 | 4106 | parser = &iter->parser; |
4107 | if (trace_parser_loaded(parser)) { | |
4108 | parser->buffer[parser->idx] = 0; | |
1cf41dd7 | 4109 | ftrace_match_records(iter->hash, parser->buffer, parser->idx); |
5072c59f SR |
4110 | } |
4111 | ||
689fd8b6 | 4112 | trace_parser_put(parser); |
689fd8b6 | 4113 | |
33b7f99c | 4114 | mutex_lock(&iter->ops->func_hash->regex_lock); |
3f2367ba | 4115 | |
058e297d | 4116 | if (file->f_mode & FMODE_WRITE) { |
ed926f9b SR |
4117 | filter_hash = !!(iter->flags & FTRACE_ITER_FILTER); |
4118 | ||
4119 | if (filter_hash) | |
33b7f99c | 4120 | orig_hash = &iter->ops->func_hash->filter_hash; |
ed926f9b | 4121 | else |
33b7f99c | 4122 | orig_hash = &iter->ops->func_hash->notrace_hash; |
33dc9b12 | 4123 | |
058e297d | 4124 | mutex_lock(&ftrace_lock); |
3296fc4e | 4125 | old_hash = *orig_hash; |
41fb61c2 SR |
4126 | ret = ftrace_hash_move(iter->ops, filter_hash, |
4127 | orig_hash, iter->hash); | |
3296fc4e | 4128 | if (!ret) { |
8252ecf3 | 4129 | ftrace_ops_update_code(iter->ops, old_hash); |
3296fc4e SRRH |
4130 | free_ftrace_hash_rcu(old_hash); |
4131 | } | |
058e297d SR |
4132 | mutex_unlock(&ftrace_lock); |
4133 | } | |
3f2367ba | 4134 | |
33b7f99c | 4135 | mutex_unlock(&iter->ops->func_hash->regex_lock); |
33dc9b12 SR |
4136 | free_ftrace_hash(iter->hash); |
4137 | kfree(iter); | |
058e297d | 4138 | |
5072c59f SR |
4139 | return 0; |
4140 | } | |
4141 | ||
5e2336a0 | 4142 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
4143 | .open = ftrace_avail_open, |
4144 | .read = seq_read, | |
4145 | .llseek = seq_lseek, | |
3be04b47 | 4146 | .release = seq_release_private, |
5072c59f SR |
4147 | }; |
4148 | ||
647bcd03 SR |
4149 | static const struct file_operations ftrace_enabled_fops = { |
4150 | .open = ftrace_enabled_open, | |
4151 | .read = seq_read, | |
4152 | .llseek = seq_lseek, | |
4153 | .release = seq_release_private, | |
4154 | }; | |
4155 | ||
5e2336a0 | 4156 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 4157 | .open = ftrace_filter_open, |
850a80cf | 4158 | .read = seq_read, |
5072c59f | 4159 | .write = ftrace_filter_write, |
098c879e | 4160 | .llseek = tracing_lseek, |
1cf41dd7 | 4161 | .release = ftrace_regex_release, |
5072c59f SR |
4162 | }; |
4163 | ||
5e2336a0 | 4164 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 4165 | .open = ftrace_notrace_open, |
850a80cf | 4166 | .read = seq_read, |
41c52c0d | 4167 | .write = ftrace_notrace_write, |
098c879e | 4168 | .llseek = tracing_lseek, |
1cf41dd7 | 4169 | .release = ftrace_regex_release, |
41c52c0d SR |
4170 | }; |
4171 | ||
ea4e2bc4 SR |
4172 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
4173 | ||
4174 | static DEFINE_MUTEX(graph_lock); | |
4175 | ||
4176 | int ftrace_graph_count; | |
29ad23b0 | 4177 | int ftrace_graph_notrace_count; |
ea4e2bc4 | 4178 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
29ad23b0 | 4179 | unsigned long ftrace_graph_notrace_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
ea4e2bc4 | 4180 | |
faf982a6 NK |
4181 | struct ftrace_graph_data { |
4182 | unsigned long *table; | |
4183 | size_t size; | |
4184 | int *count; | |
4185 | const struct seq_operations *seq_ops; | |
4186 | }; | |
4187 | ||
ea4e2bc4 | 4188 | static void * |
85951842 | 4189 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 4190 | { |
faf982a6 NK |
4191 | struct ftrace_graph_data *fgd = m->private; |
4192 | ||
4193 | if (*pos >= *fgd->count) | |
ea4e2bc4 | 4194 | return NULL; |
faf982a6 | 4195 | return &fgd->table[*pos]; |
85951842 | 4196 | } |
ea4e2bc4 | 4197 | |
85951842 LZ |
4198 | static void * |
4199 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
4200 | { | |
4201 | (*pos)++; | |
4202 | return __g_next(m, pos); | |
ea4e2bc4 SR |
4203 | } |
4204 | ||
4205 | static void *g_start(struct seq_file *m, loff_t *pos) | |
4206 | { | |
faf982a6 NK |
4207 | struct ftrace_graph_data *fgd = m->private; |
4208 | ||
ea4e2bc4 SR |
4209 | mutex_lock(&graph_lock); |
4210 | ||
f9349a8f | 4211 | /* Nothing, tell g_show to print all functions are enabled */ |
faf982a6 | 4212 | if (!*fgd->count && !*pos) |
f9349a8f FW |
4213 | return (void *)1; |
4214 | ||
85951842 | 4215 | return __g_next(m, pos); |
ea4e2bc4 SR |
4216 | } |
4217 | ||
4218 | static void g_stop(struct seq_file *m, void *p) | |
4219 | { | |
4220 | mutex_unlock(&graph_lock); | |
4221 | } | |
4222 | ||
4223 | static int g_show(struct seq_file *m, void *v) | |
4224 | { | |
4225 | unsigned long *ptr = v; | |
ea4e2bc4 SR |
4226 | |
4227 | if (!ptr) | |
4228 | return 0; | |
4229 | ||
f9349a8f | 4230 | if (ptr == (unsigned long *)1) { |
280d1429 NK |
4231 | struct ftrace_graph_data *fgd = m->private; |
4232 | ||
4233 | if (fgd->table == ftrace_graph_funcs) | |
4234 | seq_printf(m, "#### all functions enabled ####\n"); | |
4235 | else | |
4236 | seq_printf(m, "#### no functions disabled ####\n"); | |
f9349a8f FW |
4237 | return 0; |
4238 | } | |
4239 | ||
b375a11a | 4240 | seq_printf(m, "%ps\n", (void *)*ptr); |
ea4e2bc4 SR |
4241 | |
4242 | return 0; | |
4243 | } | |
4244 | ||
88e9d34c | 4245 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
4246 | .start = g_start, |
4247 | .next = g_next, | |
4248 | .stop = g_stop, | |
4249 | .show = g_show, | |
4250 | }; | |
4251 | ||
4252 | static int | |
faf982a6 NK |
4253 | __ftrace_graph_open(struct inode *inode, struct file *file, |
4254 | struct ftrace_graph_data *fgd) | |
ea4e2bc4 SR |
4255 | { |
4256 | int ret = 0; | |
4257 | ||
ea4e2bc4 SR |
4258 | mutex_lock(&graph_lock); |
4259 | if ((file->f_mode & FMODE_WRITE) && | |
8650ae32 | 4260 | (file->f_flags & O_TRUNC)) { |
faf982a6 NK |
4261 | *fgd->count = 0; |
4262 | memset(fgd->table, 0, fgd->size * sizeof(*fgd->table)); | |
ea4e2bc4 | 4263 | } |
a4ec5e0c | 4264 | mutex_unlock(&graph_lock); |
ea4e2bc4 | 4265 | |
faf982a6 NK |
4266 | if (file->f_mode & FMODE_READ) { |
4267 | ret = seq_open(file, fgd->seq_ops); | |
4268 | if (!ret) { | |
4269 | struct seq_file *m = file->private_data; | |
4270 | m->private = fgd; | |
4271 | } | |
4272 | } else | |
4273 | file->private_data = fgd; | |
ea4e2bc4 SR |
4274 | |
4275 | return ret; | |
4276 | } | |
4277 | ||
faf982a6 NK |
4278 | static int |
4279 | ftrace_graph_open(struct inode *inode, struct file *file) | |
4280 | { | |
4281 | struct ftrace_graph_data *fgd; | |
4282 | ||
4283 | if (unlikely(ftrace_disabled)) | |
4284 | return -ENODEV; | |
4285 | ||
4286 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
4287 | if (fgd == NULL) | |
4288 | return -ENOMEM; | |
4289 | ||
4290 | fgd->table = ftrace_graph_funcs; | |
4291 | fgd->size = FTRACE_GRAPH_MAX_FUNCS; | |
4292 | fgd->count = &ftrace_graph_count; | |
4293 | fgd->seq_ops = &ftrace_graph_seq_ops; | |
4294 | ||
4295 | return __ftrace_graph_open(inode, file, fgd); | |
4296 | } | |
4297 | ||
29ad23b0 NK |
4298 | static int |
4299 | ftrace_graph_notrace_open(struct inode *inode, struct file *file) | |
4300 | { | |
4301 | struct ftrace_graph_data *fgd; | |
4302 | ||
4303 | if (unlikely(ftrace_disabled)) | |
4304 | return -ENODEV; | |
4305 | ||
4306 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
4307 | if (fgd == NULL) | |
4308 | return -ENOMEM; | |
4309 | ||
4310 | fgd->table = ftrace_graph_notrace_funcs; | |
4311 | fgd->size = FTRACE_GRAPH_MAX_FUNCS; | |
4312 | fgd->count = &ftrace_graph_notrace_count; | |
4313 | fgd->seq_ops = &ftrace_graph_seq_ops; | |
4314 | ||
4315 | return __ftrace_graph_open(inode, file, fgd); | |
4316 | } | |
4317 | ||
87827111 LZ |
4318 | static int |
4319 | ftrace_graph_release(struct inode *inode, struct file *file) | |
4320 | { | |
faf982a6 NK |
4321 | if (file->f_mode & FMODE_READ) { |
4322 | struct seq_file *m = file->private_data; | |
4323 | ||
4324 | kfree(m->private); | |
87827111 | 4325 | seq_release(inode, file); |
faf982a6 NK |
4326 | } else { |
4327 | kfree(file->private_data); | |
4328 | } | |
4329 | ||
87827111 LZ |
4330 | return 0; |
4331 | } | |
4332 | ||
ea4e2bc4 | 4333 | static int |
faf982a6 | 4334 | ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer) |
ea4e2bc4 | 4335 | { |
ea4e2bc4 SR |
4336 | struct dyn_ftrace *rec; |
4337 | struct ftrace_page *pg; | |
f9349a8f | 4338 | int search_len; |
c7c6b1fe | 4339 | int fail = 1; |
f9349a8f FW |
4340 | int type, not; |
4341 | char *search; | |
4342 | bool exists; | |
4343 | int i; | |
ea4e2bc4 | 4344 | |
f9349a8f | 4345 | /* decode regex */ |
3f6fe06d | 4346 | type = filter_parse_regex(buffer, strlen(buffer), &search, ¬); |
faf982a6 | 4347 | if (!not && *idx >= size) |
c7c6b1fe | 4348 | return -EBUSY; |
f9349a8f FW |
4349 | |
4350 | search_len = strlen(search); | |
4351 | ||
52baf119 | 4352 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
4353 | |
4354 | if (unlikely(ftrace_disabled)) { | |
4355 | mutex_unlock(&ftrace_lock); | |
4356 | return -ENODEV; | |
4357 | } | |
4358 | ||
265c831c SR |
4359 | do_for_each_ftrace_rec(pg, rec) { |
4360 | ||
b9df92d2 | 4361 | if (ftrace_match_record(rec, NULL, search, search_len, type)) { |
c7c6b1fe | 4362 | /* if it is in the array */ |
f9349a8f | 4363 | exists = false; |
c7c6b1fe | 4364 | for (i = 0; i < *idx; i++) { |
f9349a8f FW |
4365 | if (array[i] == rec->ip) { |
4366 | exists = true; | |
265c831c SR |
4367 | break; |
4368 | } | |
c7c6b1fe LZ |
4369 | } |
4370 | ||
4371 | if (!not) { | |
4372 | fail = 0; | |
4373 | if (!exists) { | |
4374 | array[(*idx)++] = rec->ip; | |
faf982a6 | 4375 | if (*idx >= size) |
c7c6b1fe LZ |
4376 | goto out; |
4377 | } | |
4378 | } else { | |
4379 | if (exists) { | |
4380 | array[i] = array[--(*idx)]; | |
4381 | array[*idx] = 0; | |
4382 | fail = 0; | |
4383 | } | |
4384 | } | |
ea4e2bc4 | 4385 | } |
265c831c | 4386 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 4387 | out: |
52baf119 | 4388 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 4389 | |
c7c6b1fe LZ |
4390 | if (fail) |
4391 | return -EINVAL; | |
4392 | ||
c7c6b1fe | 4393 | return 0; |
ea4e2bc4 SR |
4394 | } |
4395 | ||
4396 | static ssize_t | |
4397 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
4398 | size_t cnt, loff_t *ppos) | |
4399 | { | |
689fd8b6 | 4400 | struct trace_parser parser; |
6a10108b | 4401 | ssize_t read, ret = 0; |
faf982a6 | 4402 | struct ftrace_graph_data *fgd = file->private_data; |
ea4e2bc4 | 4403 | |
c7c6b1fe | 4404 | if (!cnt) |
ea4e2bc4 SR |
4405 | return 0; |
4406 | ||
6a10108b NK |
4407 | if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) |
4408 | return -ENOMEM; | |
ea4e2bc4 | 4409 | |
689fd8b6 | 4410 | read = trace_get_user(&parser, ubuf, cnt, ppos); |
ea4e2bc4 | 4411 | |
4ba7978e | 4412 | if (read >= 0 && trace_parser_loaded((&parser))) { |
689fd8b6 | 4413 | parser.buffer[parser.idx] = 0; |
4414 | ||
6a10108b NK |
4415 | mutex_lock(&graph_lock); |
4416 | ||
689fd8b6 | 4417 | /* we allow only one expression at a time */ |
faf982a6 NK |
4418 | ret = ftrace_set_func(fgd->table, fgd->count, fgd->size, |
4419 | parser.buffer); | |
6a10108b NK |
4420 | |
4421 | mutex_unlock(&graph_lock); | |
ea4e2bc4 | 4422 | } |
ea4e2bc4 | 4423 | |
6a10108b NK |
4424 | if (!ret) |
4425 | ret = read; | |
1eb90f13 | 4426 | |
689fd8b6 | 4427 | trace_parser_put(&parser); |
ea4e2bc4 SR |
4428 | |
4429 | return ret; | |
4430 | } | |
4431 | ||
4432 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
4433 | .open = ftrace_graph_open, |
4434 | .read = seq_read, | |
4435 | .write = ftrace_graph_write, | |
098c879e | 4436 | .llseek = tracing_lseek, |
87827111 | 4437 | .release = ftrace_graph_release, |
ea4e2bc4 | 4438 | }; |
29ad23b0 NK |
4439 | |
4440 | static const struct file_operations ftrace_graph_notrace_fops = { | |
4441 | .open = ftrace_graph_notrace_open, | |
4442 | .read = seq_read, | |
4443 | .write = ftrace_graph_write, | |
098c879e | 4444 | .llseek = tracing_lseek, |
29ad23b0 NK |
4445 | .release = ftrace_graph_release, |
4446 | }; | |
ea4e2bc4 SR |
4447 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
4448 | ||
591dffda SRRH |
4449 | void ftrace_create_filter_files(struct ftrace_ops *ops, |
4450 | struct dentry *parent) | |
4451 | { | |
4452 | ||
4453 | trace_create_file("set_ftrace_filter", 0644, parent, | |
4454 | ops, &ftrace_filter_fops); | |
4455 | ||
4456 | trace_create_file("set_ftrace_notrace", 0644, parent, | |
4457 | ops, &ftrace_notrace_fops); | |
4458 | } | |
4459 | ||
4460 | /* | |
4461 | * The name "destroy_filter_files" is really a misnomer. Although | |
4462 | * in the future, it may actualy delete the files, but this is | |
4463 | * really intended to make sure the ops passed in are disabled | |
4464 | * and that when this function returns, the caller is free to | |
4465 | * free the ops. | |
4466 | * | |
4467 | * The "destroy" name is only to match the "create" name that this | |
4468 | * should be paired with. | |
4469 | */ | |
4470 | void ftrace_destroy_filter_files(struct ftrace_ops *ops) | |
4471 | { | |
4472 | mutex_lock(&ftrace_lock); | |
4473 | if (ops->flags & FTRACE_OPS_FL_ENABLED) | |
4474 | ftrace_shutdown(ops, 0); | |
4475 | ops->flags |= FTRACE_OPS_FL_DELETED; | |
4476 | mutex_unlock(&ftrace_lock); | |
4477 | } | |
4478 | ||
df4fc315 | 4479 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 4480 | { |
5072c59f | 4481 | |
5452af66 FW |
4482 | trace_create_file("available_filter_functions", 0444, |
4483 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 4484 | |
647bcd03 SR |
4485 | trace_create_file("enabled_functions", 0444, |
4486 | d_tracer, NULL, &ftrace_enabled_fops); | |
4487 | ||
591dffda | 4488 | ftrace_create_filter_files(&global_ops, d_tracer); |
ad90c0e3 | 4489 | |
ea4e2bc4 | 4490 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5452af66 | 4491 | trace_create_file("set_graph_function", 0444, d_tracer, |
ea4e2bc4 SR |
4492 | NULL, |
4493 | &ftrace_graph_fops); | |
29ad23b0 NK |
4494 | trace_create_file("set_graph_notrace", 0444, d_tracer, |
4495 | NULL, | |
4496 | &ftrace_graph_notrace_fops); | |
ea4e2bc4 SR |
4497 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
4498 | ||
5072c59f SR |
4499 | return 0; |
4500 | } | |
4501 | ||
9fd49328 | 4502 | static int ftrace_cmp_ips(const void *a, const void *b) |
68950619 | 4503 | { |
9fd49328 SR |
4504 | const unsigned long *ipa = a; |
4505 | const unsigned long *ipb = b; | |
68950619 | 4506 | |
9fd49328 SR |
4507 | if (*ipa > *ipb) |
4508 | return 1; | |
4509 | if (*ipa < *ipb) | |
4510 | return -1; | |
4511 | return 0; | |
4512 | } | |
4513 | ||
4514 | static void ftrace_swap_ips(void *a, void *b, int size) | |
4515 | { | |
4516 | unsigned long *ipa = a; | |
4517 | unsigned long *ipb = b; | |
4518 | unsigned long t; | |
4519 | ||
4520 | t = *ipa; | |
4521 | *ipa = *ipb; | |
4522 | *ipb = t; | |
68950619 SR |
4523 | } |
4524 | ||
5cb084bb | 4525 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 4526 | unsigned long *start, |
68bf21aa SR |
4527 | unsigned long *end) |
4528 | { | |
706c81f8 | 4529 | struct ftrace_page *start_pg; |
a7900875 | 4530 | struct ftrace_page *pg; |
706c81f8 | 4531 | struct dyn_ftrace *rec; |
a7900875 | 4532 | unsigned long count; |
68bf21aa SR |
4533 | unsigned long *p; |
4534 | unsigned long addr; | |
4376cac6 | 4535 | unsigned long flags = 0; /* Shut up gcc */ |
a7900875 SR |
4536 | int ret = -ENOMEM; |
4537 | ||
4538 | count = end - start; | |
4539 | ||
4540 | if (!count) | |
4541 | return 0; | |
4542 | ||
9fd49328 SR |
4543 | sort(start, count, sizeof(*start), |
4544 | ftrace_cmp_ips, ftrace_swap_ips); | |
4545 | ||
706c81f8 SR |
4546 | start_pg = ftrace_allocate_pages(count); |
4547 | if (!start_pg) | |
a7900875 | 4548 | return -ENOMEM; |
68bf21aa | 4549 | |
e6ea44e9 | 4550 | mutex_lock(&ftrace_lock); |
a7900875 | 4551 | |
32082309 SR |
4552 | /* |
4553 | * Core and each module needs their own pages, as | |
4554 | * modules will free them when they are removed. | |
4555 | * Force a new page to be allocated for modules. | |
4556 | */ | |
a7900875 SR |
4557 | if (!mod) { |
4558 | WARN_ON(ftrace_pages || ftrace_pages_start); | |
4559 | /* First initialization */ | |
706c81f8 | 4560 | ftrace_pages = ftrace_pages_start = start_pg; |
a7900875 | 4561 | } else { |
32082309 | 4562 | if (!ftrace_pages) |
a7900875 | 4563 | goto out; |
32082309 | 4564 | |
a7900875 SR |
4565 | if (WARN_ON(ftrace_pages->next)) { |
4566 | /* Hmm, we have free pages? */ | |
4567 | while (ftrace_pages->next) | |
4568 | ftrace_pages = ftrace_pages->next; | |
32082309 | 4569 | } |
a7900875 | 4570 | |
706c81f8 | 4571 | ftrace_pages->next = start_pg; |
32082309 SR |
4572 | } |
4573 | ||
68bf21aa | 4574 | p = start; |
706c81f8 | 4575 | pg = start_pg; |
68bf21aa SR |
4576 | while (p < end) { |
4577 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
4578 | /* |
4579 | * Some architecture linkers will pad between | |
4580 | * the different mcount_loc sections of different | |
4581 | * object files to satisfy alignments. | |
4582 | * Skip any NULL pointers. | |
4583 | */ | |
4584 | if (!addr) | |
4585 | continue; | |
706c81f8 SR |
4586 | |
4587 | if (pg->index == pg->size) { | |
4588 | /* We should have allocated enough */ | |
4589 | if (WARN_ON(!pg->next)) | |
4590 | break; | |
4591 | pg = pg->next; | |
4592 | } | |
4593 | ||
4594 | rec = &pg->records[pg->index++]; | |
4595 | rec->ip = addr; | |
68bf21aa SR |
4596 | } |
4597 | ||
706c81f8 SR |
4598 | /* We should have used all pages */ |
4599 | WARN_ON(pg->next); | |
4600 | ||
4601 | /* Assign the last page to ftrace_pages */ | |
4602 | ftrace_pages = pg; | |
4603 | ||
a4f18ed1 | 4604 | /* |
4376cac6 SR |
4605 | * We only need to disable interrupts on start up |
4606 | * because we are modifying code that an interrupt | |
4607 | * may execute, and the modification is not atomic. | |
4608 | * But for modules, nothing runs the code we modify | |
4609 | * until we are finished with it, and there's no | |
4610 | * reason to cause large interrupt latencies while we do it. | |
a4f18ed1 | 4611 | */ |
4376cac6 SR |
4612 | if (!mod) |
4613 | local_irq_save(flags); | |
1dc43cf0 | 4614 | ftrace_update_code(mod, start_pg); |
4376cac6 SR |
4615 | if (!mod) |
4616 | local_irq_restore(flags); | |
a7900875 SR |
4617 | ret = 0; |
4618 | out: | |
e6ea44e9 | 4619 | mutex_unlock(&ftrace_lock); |
68bf21aa | 4620 | |
a7900875 | 4621 | return ret; |
68bf21aa SR |
4622 | } |
4623 | ||
93eb677d | 4624 | #ifdef CONFIG_MODULES |
32082309 SR |
4625 | |
4626 | #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next) | |
4627 | ||
e7247a15 | 4628 | void ftrace_release_mod(struct module *mod) |
93eb677d SR |
4629 | { |
4630 | struct dyn_ftrace *rec; | |
32082309 | 4631 | struct ftrace_page **last_pg; |
93eb677d | 4632 | struct ftrace_page *pg; |
a7900875 | 4633 | int order; |
93eb677d | 4634 | |
45a4a237 SR |
4635 | mutex_lock(&ftrace_lock); |
4636 | ||
e7247a15 | 4637 | if (ftrace_disabled) |
45a4a237 | 4638 | goto out_unlock; |
93eb677d | 4639 | |
32082309 SR |
4640 | /* |
4641 | * Each module has its own ftrace_pages, remove | |
4642 | * them from the list. | |
4643 | */ | |
4644 | last_pg = &ftrace_pages_start; | |
4645 | for (pg = ftrace_pages_start; pg; pg = *last_pg) { | |
4646 | rec = &pg->records[0]; | |
e7247a15 | 4647 | if (within_module_core(rec->ip, mod)) { |
93eb677d | 4648 | /* |
32082309 SR |
4649 | * As core pages are first, the first |
4650 | * page should never be a module page. | |
93eb677d | 4651 | */ |
32082309 SR |
4652 | if (WARN_ON(pg == ftrace_pages_start)) |
4653 | goto out_unlock; | |
4654 | ||
4655 | /* Check if we are deleting the last page */ | |
4656 | if (pg == ftrace_pages) | |
4657 | ftrace_pages = next_to_ftrace_page(last_pg); | |
4658 | ||
4659 | *last_pg = pg->next; | |
a7900875 SR |
4660 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
4661 | free_pages((unsigned long)pg->records, order); | |
4662 | kfree(pg); | |
32082309 SR |
4663 | } else |
4664 | last_pg = &pg->next; | |
4665 | } | |
45a4a237 | 4666 | out_unlock: |
93eb677d SR |
4667 | mutex_unlock(&ftrace_lock); |
4668 | } | |
4669 | ||
4670 | static void ftrace_init_module(struct module *mod, | |
4671 | unsigned long *start, unsigned long *end) | |
90d595fe | 4672 | { |
00fd61ae | 4673 | if (ftrace_disabled || start == end) |
fed1939c | 4674 | return; |
5cb084bb | 4675 | ftrace_process_locs(mod, start, end); |
90d595fe SR |
4676 | } |
4677 | ||
a949ae56 | 4678 | void ftrace_module_init(struct module *mod) |
93eb677d | 4679 | { |
a949ae56 SRRH |
4680 | ftrace_init_module(mod, mod->ftrace_callsites, |
4681 | mod->ftrace_callsites + | |
4682 | mod->num_ftrace_callsites); | |
8c189ea6 SRRH |
4683 | } |
4684 | ||
4685 | static int ftrace_module_notify_exit(struct notifier_block *self, | |
4686 | unsigned long val, void *data) | |
4687 | { | |
4688 | struct module *mod = data; | |
4689 | ||
4690 | if (val == MODULE_STATE_GOING) | |
e7247a15 | 4691 | ftrace_release_mod(mod); |
93eb677d SR |
4692 | |
4693 | return 0; | |
4694 | } | |
4695 | #else | |
8c189ea6 SRRH |
4696 | static int ftrace_module_notify_exit(struct notifier_block *self, |
4697 | unsigned long val, void *data) | |
93eb677d SR |
4698 | { |
4699 | return 0; | |
4700 | } | |
4701 | #endif /* CONFIG_MODULES */ | |
4702 | ||
8c189ea6 SRRH |
4703 | struct notifier_block ftrace_module_exit_nb = { |
4704 | .notifier_call = ftrace_module_notify_exit, | |
4705 | .priority = INT_MIN, /* Run after anything that can remove kprobes */ | |
4706 | }; | |
4707 | ||
68bf21aa SR |
4708 | void __init ftrace_init(void) |
4709 | { | |
1dc43cf0 JS |
4710 | extern unsigned long __start_mcount_loc[]; |
4711 | extern unsigned long __stop_mcount_loc[]; | |
3a36cb11 | 4712 | unsigned long count, flags; |
68bf21aa SR |
4713 | int ret; |
4714 | ||
68bf21aa | 4715 | local_irq_save(flags); |
3a36cb11 | 4716 | ret = ftrace_dyn_arch_init(); |
68bf21aa | 4717 | local_irq_restore(flags); |
af64a7cb | 4718 | if (ret) |
68bf21aa SR |
4719 | goto failed; |
4720 | ||
4721 | count = __stop_mcount_loc - __start_mcount_loc; | |
c867ccd8 JS |
4722 | if (!count) { |
4723 | pr_info("ftrace: No functions to be traced?\n"); | |
68bf21aa | 4724 | goto failed; |
c867ccd8 JS |
4725 | } |
4726 | ||
4727 | pr_info("ftrace: allocating %ld entries in %ld pages\n", | |
4728 | count, count / ENTRIES_PER_PAGE + 1); | |
68bf21aa SR |
4729 | |
4730 | last_ftrace_enabled = ftrace_enabled = 1; | |
4731 | ||
5cb084bb | 4732 | ret = ftrace_process_locs(NULL, |
31e88909 | 4733 | __start_mcount_loc, |
68bf21aa SR |
4734 | __stop_mcount_loc); |
4735 | ||
8c189ea6 | 4736 | ret = register_module_notifier(&ftrace_module_exit_nb); |
24ed0c4b | 4737 | if (ret) |
8c189ea6 | 4738 | pr_warning("Failed to register trace ftrace module exit notifier\n"); |
93eb677d | 4739 | |
2af15d6a SR |
4740 | set_ftrace_early_filters(); |
4741 | ||
68bf21aa SR |
4742 | return; |
4743 | failed: | |
4744 | ftrace_disabled = 1; | |
4745 | } | |
68bf21aa | 4746 | |
f3bea491 SRRH |
4747 | /* Do nothing if arch does not support this */ |
4748 | void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops) | |
4749 | { | |
4750 | } | |
4751 | ||
4752 | static void ftrace_update_trampoline(struct ftrace_ops *ops) | |
4753 | { | |
12cce594 SRRH |
4754 | |
4755 | /* | |
4756 | * Currently there's no safe way to free a trampoline when the kernel | |
4757 | * is configured with PREEMPT. That is because a task could be preempted | |
4758 | * when it jumped to the trampoline, it may be preempted for a long time | |
4759 | * depending on the system load, and currently there's no way to know | |
4760 | * when it will be off the trampoline. If the trampoline is freed | |
4761 | * too early, when the task runs again, it will be executing on freed | |
4762 | * memory and crash. | |
4763 | */ | |
4764 | #ifdef CONFIG_PREEMPT | |
f3bea491 SRRH |
4765 | /* Currently, only non dynamic ops can have a trampoline */ |
4766 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC) | |
4767 | return; | |
12cce594 | 4768 | #endif |
f3bea491 SRRH |
4769 | |
4770 | arch_ftrace_update_trampoline(ops); | |
4771 | } | |
4772 | ||
3d083395 | 4773 | #else |
0b6e4d56 | 4774 | |
2b499381 | 4775 | static struct ftrace_ops global_ops = { |
bd69c30b | 4776 | .func = ftrace_stub, |
f04f24fb | 4777 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, |
bd69c30b SR |
4778 | }; |
4779 | ||
0b6e4d56 FW |
4780 | static int __init ftrace_nodyn_init(void) |
4781 | { | |
4782 | ftrace_enabled = 1; | |
4783 | return 0; | |
4784 | } | |
6f415672 | 4785 | core_initcall(ftrace_nodyn_init); |
0b6e4d56 | 4786 | |
df4fc315 SR |
4787 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
4788 | static inline void ftrace_startup_enable(int command) { } | |
e1effa01 | 4789 | static inline void ftrace_startup_all(int command) { } |
5a45cfe1 | 4790 | /* Keep as macros so we do not need to define the commands */ |
8a56d776 SRRH |
4791 | # define ftrace_startup(ops, command) \ |
4792 | ({ \ | |
4793 | int ___ret = __register_ftrace_function(ops); \ | |
4794 | if (!___ret) \ | |
4795 | (ops)->flags |= FTRACE_OPS_FL_ENABLED; \ | |
4796 | ___ret; \ | |
3b6cfdb1 | 4797 | }) |
1fcc1553 SRRH |
4798 | # define ftrace_shutdown(ops, command) \ |
4799 | ({ \ | |
4800 | int ___ret = __unregister_ftrace_function(ops); \ | |
4801 | if (!___ret) \ | |
4802 | (ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \ | |
4803 | ___ret; \ | |
4804 | }) | |
8a56d776 | 4805 | |
c7aafc54 IM |
4806 | # define ftrace_startup_sysctl() do { } while (0) |
4807 | # define ftrace_shutdown_sysctl() do { } while (0) | |
b848914c SR |
4808 | |
4809 | static inline int | |
195a8afc | 4810 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
b848914c SR |
4811 | { |
4812 | return 1; | |
4813 | } | |
4814 | ||
f3bea491 SRRH |
4815 | static void ftrace_update_trampoline(struct ftrace_ops *ops) |
4816 | { | |
4817 | } | |
4818 | ||
3d083395 SR |
4819 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
4820 | ||
4104d326 SRRH |
4821 | __init void ftrace_init_global_array_ops(struct trace_array *tr) |
4822 | { | |
4823 | tr->ops = &global_ops; | |
4824 | tr->ops->private = tr; | |
4825 | } | |
4826 | ||
4827 | void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func) | |
4828 | { | |
4829 | /* If we filter on pids, update to use the pid function */ | |
4830 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL) { | |
4831 | if (WARN_ON(tr->ops->func != ftrace_stub)) | |
4832 | printk("ftrace ops had %pS for function\n", | |
4833 | tr->ops->func); | |
4834 | /* Only the top level instance does pid tracing */ | |
4835 | if (!list_empty(&ftrace_pids)) { | |
4836 | set_ftrace_pid_function(func); | |
4837 | func = ftrace_pid_func; | |
4838 | } | |
4839 | } | |
4840 | tr->ops->func = func; | |
4841 | tr->ops->private = tr; | |
4842 | } | |
4843 | ||
4844 | void ftrace_reset_array_ops(struct trace_array *tr) | |
4845 | { | |
4846 | tr->ops->func = ftrace_stub; | |
4847 | } | |
4848 | ||
e248491a | 4849 | static void |
2f5f6ad9 | 4850 | ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 4851 | struct ftrace_ops *op, struct pt_regs *regs) |
e248491a | 4852 | { |
e248491a JO |
4853 | if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT))) |
4854 | return; | |
4855 | ||
4856 | /* | |
4857 | * Some of the ops may be dynamically allocated, | |
4858 | * they must be freed after a synchronize_sched(). | |
4859 | */ | |
4860 | preempt_disable_notrace(); | |
4861 | trace_recursion_set(TRACE_CONTROL_BIT); | |
b5aa3a47 SRRH |
4862 | |
4863 | /* | |
4864 | * Control funcs (perf) uses RCU. Only trace if | |
4865 | * RCU is currently active. | |
4866 | */ | |
4867 | if (!rcu_is_watching()) | |
4868 | goto out; | |
4869 | ||
0a016409 | 4870 | do_for_each_ftrace_op(op, ftrace_control_list) { |
395b97a3 SRRH |
4871 | if (!(op->flags & FTRACE_OPS_FL_STUB) && |
4872 | !ftrace_function_local_disabled(op) && | |
195a8afc | 4873 | ftrace_ops_test(op, ip, regs)) |
a1e2e31d | 4874 | op->func(ip, parent_ip, op, regs); |
0a016409 | 4875 | } while_for_each_ftrace_op(op); |
b5aa3a47 | 4876 | out: |
e248491a JO |
4877 | trace_recursion_clear(TRACE_CONTROL_BIT); |
4878 | preempt_enable_notrace(); | |
4879 | } | |
4880 | ||
4881 | static struct ftrace_ops control_ops = { | |
f04f24fb MH |
4882 | .func = ftrace_ops_control_func, |
4883 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, | |
33b7f99c | 4884 | INIT_OPS_HASH(control_ops) |
e248491a JO |
4885 | }; |
4886 | ||
2f5f6ad9 SR |
4887 | static inline void |
4888 | __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 4889 | struct ftrace_ops *ignored, struct pt_regs *regs) |
b848914c | 4890 | { |
cdbe61bf | 4891 | struct ftrace_ops *op; |
edc15caf | 4892 | int bit; |
b848914c | 4893 | |
edc15caf SR |
4894 | bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX); |
4895 | if (bit < 0) | |
4896 | return; | |
b1cff0ad | 4897 | |
cdbe61bf SR |
4898 | /* |
4899 | * Some of the ops may be dynamically allocated, | |
4900 | * they must be freed after a synchronize_sched(). | |
4901 | */ | |
4902 | preempt_disable_notrace(); | |
0a016409 | 4903 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
4104d326 | 4904 | if (ftrace_ops_test(op, ip, regs)) { |
1d48d596 SRRH |
4905 | if (FTRACE_WARN_ON(!op->func)) { |
4906 | pr_warn("op=%p %pS\n", op, op); | |
4104d326 SRRH |
4907 | goto out; |
4908 | } | |
a1e2e31d | 4909 | op->func(ip, parent_ip, op, regs); |
4104d326 | 4910 | } |
0a016409 | 4911 | } while_for_each_ftrace_op(op); |
4104d326 | 4912 | out: |
cdbe61bf | 4913 | preempt_enable_notrace(); |
edc15caf | 4914 | trace_clear_recursion(bit); |
b848914c SR |
4915 | } |
4916 | ||
2f5f6ad9 SR |
4917 | /* |
4918 | * Some archs only support passing ip and parent_ip. Even though | |
4919 | * the list function ignores the op parameter, we do not want any | |
4920 | * C side effects, where a function is called without the caller | |
4921 | * sending a third parameter. | |
a1e2e31d SR |
4922 | * Archs are to support both the regs and ftrace_ops at the same time. |
4923 | * If they support ftrace_ops, it is assumed they support regs. | |
4924 | * If call backs want to use regs, they must either check for regs | |
06aeaaea MH |
4925 | * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS. |
4926 | * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved. | |
a1e2e31d SR |
4927 | * An architecture can pass partial regs with ftrace_ops and still |
4928 | * set the ARCH_SUPPORT_FTARCE_OPS. | |
2f5f6ad9 SR |
4929 | */ |
4930 | #if ARCH_SUPPORTS_FTRACE_OPS | |
4931 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 4932 | struct ftrace_ops *op, struct pt_regs *regs) |
2f5f6ad9 | 4933 | { |
a1e2e31d | 4934 | __ftrace_ops_list_func(ip, parent_ip, NULL, regs); |
2f5f6ad9 SR |
4935 | } |
4936 | #else | |
4937 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip) | |
4938 | { | |
a1e2e31d | 4939 | __ftrace_ops_list_func(ip, parent_ip, NULL, NULL); |
2f5f6ad9 SR |
4940 | } |
4941 | #endif | |
4942 | ||
f1ff6348 SRRH |
4943 | /* |
4944 | * If there's only one function registered but it does not support | |
4945 | * recursion, this function will be called by the mcount trampoline. | |
4946 | * This function will handle recursion protection. | |
4947 | */ | |
4948 | static void ftrace_ops_recurs_func(unsigned long ip, unsigned long parent_ip, | |
4949 | struct ftrace_ops *op, struct pt_regs *regs) | |
4950 | { | |
4951 | int bit; | |
4952 | ||
4953 | bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX); | |
4954 | if (bit < 0) | |
4955 | return; | |
4956 | ||
4957 | op->func(ip, parent_ip, op, regs); | |
4958 | ||
4959 | trace_clear_recursion(bit); | |
4960 | } | |
4961 | ||
87354059 SRRH |
4962 | /** |
4963 | * ftrace_ops_get_func - get the function a trampoline should call | |
4964 | * @ops: the ops to get the function for | |
4965 | * | |
4966 | * Normally the mcount trampoline will call the ops->func, but there | |
4967 | * are times that it should not. For example, if the ops does not | |
4968 | * have its own recursion protection, then it should call the | |
4969 | * ftrace_ops_recurs_func() instead. | |
4970 | * | |
4971 | * Returns the function that the trampoline should call for @ops. | |
4972 | */ | |
4973 | ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops) | |
4974 | { | |
4975 | /* | |
4976 | * If this is a dynamic ops or we force list func, | |
4977 | * then it needs to call the list anyway. | |
4978 | */ | |
4979 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC || FTRACE_FORCE_LIST_FUNC) | |
4980 | return ftrace_ops_list_func; | |
4981 | ||
4982 | /* | |
4983 | * If the func handles its own recursion, call it directly. | |
4984 | * Otherwise call the recursion protected function that | |
4985 | * will call the ftrace ops function. | |
4986 | */ | |
4987 | if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE)) | |
4988 | return ftrace_ops_recurs_func; | |
4989 | ||
4990 | return ops->func; | |
4991 | } | |
4992 | ||
e32d8956 | 4993 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
4994 | { |
4995 | struct task_struct *p; | |
e32d8956 | 4996 | int cpu; |
978f3a45 | 4997 | |
e32d8956 SR |
4998 | get_online_cpus(); |
4999 | for_each_online_cpu(cpu) { | |
5000 | p = idle_task(cpu); | |
978f3a45 | 5001 | clear_tsk_trace_trace(p); |
e32d8956 SR |
5002 | } |
5003 | put_online_cpus(); | |
5004 | } | |
978f3a45 | 5005 | |
e32d8956 SR |
5006 | static void set_ftrace_swapper(void) |
5007 | { | |
5008 | struct task_struct *p; | |
5009 | int cpu; | |
5010 | ||
5011 | get_online_cpus(); | |
5012 | for_each_online_cpu(cpu) { | |
5013 | p = idle_task(cpu); | |
5014 | set_tsk_trace_trace(p); | |
5015 | } | |
5016 | put_online_cpus(); | |
978f3a45 SR |
5017 | } |
5018 | ||
e32d8956 SR |
5019 | static void clear_ftrace_pid(struct pid *pid) |
5020 | { | |
5021 | struct task_struct *p; | |
5022 | ||
229c4ef8 | 5023 | rcu_read_lock(); |
e32d8956 SR |
5024 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
5025 | clear_tsk_trace_trace(p); | |
5026 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
5027 | rcu_read_unlock(); |
5028 | ||
e32d8956 SR |
5029 | put_pid(pid); |
5030 | } | |
5031 | ||
5032 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
5033 | { |
5034 | struct task_struct *p; | |
5035 | ||
229c4ef8 | 5036 | rcu_read_lock(); |
978f3a45 SR |
5037 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
5038 | set_tsk_trace_trace(p); | |
5039 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 5040 | rcu_read_unlock(); |
978f3a45 SR |
5041 | } |
5042 | ||
756d17ee | 5043 | static void clear_ftrace_pid_task(struct pid *pid) |
e32d8956 | 5044 | { |
756d17ee | 5045 | if (pid == ftrace_swapper_pid) |
e32d8956 SR |
5046 | clear_ftrace_swapper(); |
5047 | else | |
756d17ee | 5048 | clear_ftrace_pid(pid); |
e32d8956 SR |
5049 | } |
5050 | ||
5051 | static void set_ftrace_pid_task(struct pid *pid) | |
5052 | { | |
5053 | if (pid == ftrace_swapper_pid) | |
5054 | set_ftrace_swapper(); | |
5055 | else | |
5056 | set_ftrace_pid(pid); | |
5057 | } | |
5058 | ||
756d17ee | 5059 | static int ftrace_pid_add(int p) |
df4fc315 | 5060 | { |
978f3a45 | 5061 | struct pid *pid; |
756d17ee | 5062 | struct ftrace_pid *fpid; |
5063 | int ret = -EINVAL; | |
df4fc315 | 5064 | |
756d17ee | 5065 | mutex_lock(&ftrace_lock); |
df4fc315 | 5066 | |
756d17ee | 5067 | if (!p) |
5068 | pid = ftrace_swapper_pid; | |
5069 | else | |
5070 | pid = find_get_pid(p); | |
df4fc315 | 5071 | |
756d17ee | 5072 | if (!pid) |
5073 | goto out; | |
df4fc315 | 5074 | |
756d17ee | 5075 | ret = 0; |
df4fc315 | 5076 | |
756d17ee | 5077 | list_for_each_entry(fpid, &ftrace_pids, list) |
5078 | if (fpid->pid == pid) | |
5079 | goto out_put; | |
978f3a45 | 5080 | |
756d17ee | 5081 | ret = -ENOMEM; |
df4fc315 | 5082 | |
756d17ee | 5083 | fpid = kmalloc(sizeof(*fpid), GFP_KERNEL); |
5084 | if (!fpid) | |
5085 | goto out_put; | |
df4fc315 | 5086 | |
756d17ee | 5087 | list_add(&fpid->list, &ftrace_pids); |
5088 | fpid->pid = pid; | |
0ef8cde5 | 5089 | |
756d17ee | 5090 | set_ftrace_pid_task(pid); |
978f3a45 | 5091 | |
756d17ee | 5092 | ftrace_update_pid_func(); |
e1effa01 SRRH |
5093 | |
5094 | ftrace_startup_all(0); | |
756d17ee | 5095 | |
5096 | mutex_unlock(&ftrace_lock); | |
5097 | return 0; | |
5098 | ||
5099 | out_put: | |
5100 | if (pid != ftrace_swapper_pid) | |
5101 | put_pid(pid); | |
978f3a45 | 5102 | |
756d17ee | 5103 | out: |
5104 | mutex_unlock(&ftrace_lock); | |
5105 | return ret; | |
5106 | } | |
5107 | ||
5108 | static void ftrace_pid_reset(void) | |
5109 | { | |
5110 | struct ftrace_pid *fpid, *safe; | |
978f3a45 | 5111 | |
756d17ee | 5112 | mutex_lock(&ftrace_lock); |
5113 | list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) { | |
5114 | struct pid *pid = fpid->pid; | |
5115 | ||
5116 | clear_ftrace_pid_task(pid); | |
5117 | ||
5118 | list_del(&fpid->list); | |
5119 | kfree(fpid); | |
df4fc315 SR |
5120 | } |
5121 | ||
df4fc315 | 5122 | ftrace_update_pid_func(); |
e1effa01 | 5123 | ftrace_startup_all(0); |
df4fc315 | 5124 | |
e6ea44e9 | 5125 | mutex_unlock(&ftrace_lock); |
756d17ee | 5126 | } |
df4fc315 | 5127 | |
756d17ee | 5128 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
5129 | { | |
5130 | mutex_lock(&ftrace_lock); | |
5131 | ||
5132 | if (list_empty(&ftrace_pids) && (!*pos)) | |
5133 | return (void *) 1; | |
5134 | ||
5135 | return seq_list_start(&ftrace_pids, *pos); | |
5136 | } | |
5137 | ||
5138 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
5139 | { | |
5140 | if (v == (void *)1) | |
5141 | return NULL; | |
5142 | ||
5143 | return seq_list_next(v, &ftrace_pids, pos); | |
5144 | } | |
5145 | ||
5146 | static void fpid_stop(struct seq_file *m, void *p) | |
5147 | { | |
5148 | mutex_unlock(&ftrace_lock); | |
5149 | } | |
5150 | ||
5151 | static int fpid_show(struct seq_file *m, void *v) | |
5152 | { | |
5153 | const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list); | |
5154 | ||
5155 | if (v == (void *)1) { | |
5156 | seq_printf(m, "no pid\n"); | |
5157 | return 0; | |
5158 | } | |
5159 | ||
5160 | if (fpid->pid == ftrace_swapper_pid) | |
5161 | seq_printf(m, "swapper tasks\n"); | |
5162 | else | |
5163 | seq_printf(m, "%u\n", pid_vnr(fpid->pid)); | |
5164 | ||
5165 | return 0; | |
5166 | } | |
5167 | ||
5168 | static const struct seq_operations ftrace_pid_sops = { | |
5169 | .start = fpid_start, | |
5170 | .next = fpid_next, | |
5171 | .stop = fpid_stop, | |
5172 | .show = fpid_show, | |
5173 | }; | |
5174 | ||
5175 | static int | |
5176 | ftrace_pid_open(struct inode *inode, struct file *file) | |
5177 | { | |
5178 | int ret = 0; | |
5179 | ||
5180 | if ((file->f_mode & FMODE_WRITE) && | |
5181 | (file->f_flags & O_TRUNC)) | |
5182 | ftrace_pid_reset(); | |
5183 | ||
5184 | if (file->f_mode & FMODE_READ) | |
5185 | ret = seq_open(file, &ftrace_pid_sops); | |
5186 | ||
5187 | return ret; | |
5188 | } | |
5189 | ||
df4fc315 SR |
5190 | static ssize_t |
5191 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
5192 | size_t cnt, loff_t *ppos) | |
5193 | { | |
457dc928 | 5194 | char buf[64], *tmp; |
df4fc315 SR |
5195 | long val; |
5196 | int ret; | |
5197 | ||
5198 | if (cnt >= sizeof(buf)) | |
5199 | return -EINVAL; | |
5200 | ||
5201 | if (copy_from_user(&buf, ubuf, cnt)) | |
5202 | return -EFAULT; | |
5203 | ||
5204 | buf[cnt] = 0; | |
5205 | ||
756d17ee | 5206 | /* |
5207 | * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid" | |
5208 | * to clean the filter quietly. | |
5209 | */ | |
457dc928 IM |
5210 | tmp = strstrip(buf); |
5211 | if (strlen(tmp) == 0) | |
756d17ee | 5212 | return 1; |
5213 | ||
bcd83ea6 | 5214 | ret = kstrtol(tmp, 10, &val); |
df4fc315 SR |
5215 | if (ret < 0) |
5216 | return ret; | |
5217 | ||
756d17ee | 5218 | ret = ftrace_pid_add(val); |
df4fc315 | 5219 | |
756d17ee | 5220 | return ret ? ret : cnt; |
5221 | } | |
df4fc315 | 5222 | |
756d17ee | 5223 | static int |
5224 | ftrace_pid_release(struct inode *inode, struct file *file) | |
5225 | { | |
5226 | if (file->f_mode & FMODE_READ) | |
5227 | seq_release(inode, file); | |
df4fc315 | 5228 | |
756d17ee | 5229 | return 0; |
df4fc315 SR |
5230 | } |
5231 | ||
5e2336a0 | 5232 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 5233 | .open = ftrace_pid_open, |
5234 | .write = ftrace_pid_write, | |
5235 | .read = seq_read, | |
098c879e | 5236 | .llseek = tracing_lseek, |
756d17ee | 5237 | .release = ftrace_pid_release, |
df4fc315 SR |
5238 | }; |
5239 | ||
5240 | static __init int ftrace_init_debugfs(void) | |
5241 | { | |
5242 | struct dentry *d_tracer; | |
df4fc315 SR |
5243 | |
5244 | d_tracer = tracing_init_dentry(); | |
5245 | if (!d_tracer) | |
5246 | return 0; | |
5247 | ||
5248 | ftrace_init_dyn_debugfs(d_tracer); | |
5249 | ||
5452af66 FW |
5250 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
5251 | NULL, &ftrace_pid_fops); | |
493762fc SR |
5252 | |
5253 | ftrace_profile_debugfs(d_tracer); | |
5254 | ||
df4fc315 SR |
5255 | return 0; |
5256 | } | |
df4fc315 SR |
5257 | fs_initcall(ftrace_init_debugfs); |
5258 | ||
a2bb6a3d | 5259 | /** |
81adbdc0 | 5260 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
5261 | * |
5262 | * This function should be used by panic code. It stops ftrace | |
5263 | * but in a not so nice way. If you need to simply kill ftrace | |
5264 | * from a non-atomic section, use ftrace_kill. | |
5265 | */ | |
81adbdc0 | 5266 | void ftrace_kill(void) |
a2bb6a3d SR |
5267 | { |
5268 | ftrace_disabled = 1; | |
5269 | ftrace_enabled = 0; | |
a2bb6a3d SR |
5270 | clear_ftrace_function(); |
5271 | } | |
5272 | ||
e0a413f6 SR |
5273 | /** |
5274 | * Test if ftrace is dead or not. | |
5275 | */ | |
5276 | int ftrace_is_dead(void) | |
5277 | { | |
5278 | return ftrace_disabled; | |
5279 | } | |
5280 | ||
16444a8a | 5281 | /** |
3d083395 SR |
5282 | * register_ftrace_function - register a function for profiling |
5283 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 5284 | * |
3d083395 SR |
5285 | * Register a function to be called by all functions in the |
5286 | * kernel. | |
5287 | * | |
5288 | * Note: @ops->func and all the functions it calls must be labeled | |
5289 | * with "notrace", otherwise it will go into a | |
5290 | * recursive loop. | |
16444a8a | 5291 | */ |
3d083395 | 5292 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 5293 | { |
45a4a237 | 5294 | int ret = -1; |
4eebcc81 | 5295 | |
f04f24fb MH |
5296 | ftrace_ops_init(ops); |
5297 | ||
e6ea44e9 | 5298 | mutex_lock(&ftrace_lock); |
e7d3737e | 5299 | |
8a56d776 | 5300 | ret = ftrace_startup(ops, 0); |
b848914c | 5301 | |
e6ea44e9 | 5302 | mutex_unlock(&ftrace_lock); |
8d240dd8 | 5303 | |
b0fc494f | 5304 | return ret; |
3d083395 | 5305 | } |
cdbe61bf | 5306 | EXPORT_SYMBOL_GPL(register_ftrace_function); |
3d083395 SR |
5307 | |
5308 | /** | |
32632920 | 5309 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
5310 | * @ops - ops structure that holds the function to unregister |
5311 | * | |
5312 | * Unregister a function that was added to be called by ftrace profiling. | |
5313 | */ | |
5314 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
5315 | { | |
5316 | int ret; | |
5317 | ||
e6ea44e9 | 5318 | mutex_lock(&ftrace_lock); |
8a56d776 | 5319 | ret = ftrace_shutdown(ops, 0); |
e6ea44e9 | 5320 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
5321 | |
5322 | return ret; | |
5323 | } | |
cdbe61bf | 5324 | EXPORT_SYMBOL_GPL(unregister_ftrace_function); |
b0fc494f | 5325 | |
e309b41d | 5326 | int |
b0fc494f | 5327 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
8d65af78 | 5328 | void __user *buffer, size_t *lenp, |
b0fc494f SR |
5329 | loff_t *ppos) |
5330 | { | |
45a4a237 | 5331 | int ret = -ENODEV; |
4eebcc81 | 5332 | |
e6ea44e9 | 5333 | mutex_lock(&ftrace_lock); |
b0fc494f | 5334 | |
45a4a237 SR |
5335 | if (unlikely(ftrace_disabled)) |
5336 | goto out; | |
5337 | ||
5338 | ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
b0fc494f | 5339 | |
a32c7765 | 5340 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
5341 | goto out; |
5342 | ||
a32c7765 | 5343 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f SR |
5344 | |
5345 | if (ftrace_enabled) { | |
5346 | ||
5347 | ftrace_startup_sysctl(); | |
5348 | ||
5349 | /* we are starting ftrace again */ | |
5000c418 JK |
5350 | if (ftrace_ops_list != &ftrace_list_end) |
5351 | update_ftrace_function(); | |
b0fc494f SR |
5352 | |
5353 | } else { | |
5354 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
5355 | ftrace_trace_function = ftrace_stub; | |
5356 | ||
5357 | ftrace_shutdown_sysctl(); | |
5358 | } | |
5359 | ||
5360 | out: | |
e6ea44e9 | 5361 | mutex_unlock(&ftrace_lock); |
3d083395 | 5362 | return ret; |
16444a8a | 5363 | } |
f17845e5 | 5364 | |
fb52607a | 5365 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 5366 | |
5f151b24 SRRH |
5367 | static struct ftrace_ops graph_ops = { |
5368 | .func = ftrace_stub, | |
5369 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | | |
5370 | FTRACE_OPS_FL_INITIALIZED | | |
5371 | FTRACE_OPS_FL_STUB, | |
5372 | #ifdef FTRACE_GRAPH_TRAMP_ADDR | |
5373 | .trampoline = FTRACE_GRAPH_TRAMP_ADDR, | |
5374 | #endif | |
5375 | ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash) | |
5376 | }; | |
5377 | ||
597af815 | 5378 | static int ftrace_graph_active; |
e7d3737e | 5379 | |
e49dc19c SR |
5380 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
5381 | { | |
5382 | return 0; | |
5383 | } | |
5384 | ||
287b6e68 FW |
5385 | /* The callbacks that hook a function */ |
5386 | trace_func_graph_ret_t ftrace_graph_return = | |
5387 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 5388 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
23a8e844 | 5389 | static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
5390 | |
5391 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
5392 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
5393 | { | |
5394 | int i; | |
5395 | int ret = 0; | |
5396 | unsigned long flags; | |
5397 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
5398 | struct task_struct *g, *t; | |
5399 | ||
5400 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
5401 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
5402 | * sizeof(struct ftrace_ret_stack), | |
5403 | GFP_KERNEL); | |
5404 | if (!ret_stack_list[i]) { | |
5405 | start = 0; | |
5406 | end = i; | |
5407 | ret = -ENOMEM; | |
5408 | goto free; | |
5409 | } | |
5410 | } | |
5411 | ||
5412 | read_lock_irqsave(&tasklist_lock, flags); | |
5413 | do_each_thread(g, t) { | |
5414 | if (start == end) { | |
5415 | ret = -EAGAIN; | |
5416 | goto unlock; | |
5417 | } | |
5418 | ||
5419 | if (t->ret_stack == NULL) { | |
380c4b14 | 5420 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 5421 | atomic_set(&t->trace_overrun, 0); |
26c01624 SR |
5422 | t->curr_ret_stack = -1; |
5423 | /* Make sure the tasks see the -1 first: */ | |
5424 | smp_wmb(); | |
5425 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
5426 | } |
5427 | } while_each_thread(g, t); | |
5428 | ||
5429 | unlock: | |
5430 | read_unlock_irqrestore(&tasklist_lock, flags); | |
5431 | free: | |
5432 | for (i = start; i < end; i++) | |
5433 | kfree(ret_stack_list[i]); | |
5434 | return ret; | |
5435 | } | |
5436 | ||
8aef2d28 | 5437 | static void |
38516ab5 SR |
5438 | ftrace_graph_probe_sched_switch(void *ignore, |
5439 | struct task_struct *prev, struct task_struct *next) | |
8aef2d28 SR |
5440 | { |
5441 | unsigned long long timestamp; | |
5442 | int index; | |
5443 | ||
be6f164a SR |
5444 | /* |
5445 | * Does the user want to count the time a function was asleep. | |
5446 | * If so, do not update the time stamps. | |
5447 | */ | |
5448 | if (trace_flags & TRACE_ITER_SLEEP_TIME) | |
5449 | return; | |
5450 | ||
8aef2d28 SR |
5451 | timestamp = trace_clock_local(); |
5452 | ||
5453 | prev->ftrace_timestamp = timestamp; | |
5454 | ||
5455 | /* only process tasks that we timestamped */ | |
5456 | if (!next->ftrace_timestamp) | |
5457 | return; | |
5458 | ||
5459 | /* | |
5460 | * Update all the counters in next to make up for the | |
5461 | * time next was sleeping. | |
5462 | */ | |
5463 | timestamp -= next->ftrace_timestamp; | |
5464 | ||
5465 | for (index = next->curr_ret_stack; index >= 0; index--) | |
5466 | next->ret_stack[index].calltime += timestamp; | |
5467 | } | |
5468 | ||
f201ae23 | 5469 | /* Allocate a return stack for each task */ |
fb52607a | 5470 | static int start_graph_tracing(void) |
f201ae23 FW |
5471 | { |
5472 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 5473 | int ret, cpu; |
f201ae23 FW |
5474 | |
5475 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
5476 | sizeof(struct ftrace_ret_stack *), | |
5477 | GFP_KERNEL); | |
5478 | ||
5479 | if (!ret_stack_list) | |
5480 | return -ENOMEM; | |
5481 | ||
5b058bcd | 5482 | /* The cpu_boot init_task->ret_stack will never be freed */ |
179c498a SR |
5483 | for_each_online_cpu(cpu) { |
5484 | if (!idle_task(cpu)->ret_stack) | |
868baf07 | 5485 | ftrace_graph_init_idle_task(idle_task(cpu), cpu); |
179c498a | 5486 | } |
5b058bcd | 5487 | |
f201ae23 FW |
5488 | do { |
5489 | ret = alloc_retstack_tasklist(ret_stack_list); | |
5490 | } while (ret == -EAGAIN); | |
5491 | ||
8aef2d28 | 5492 | if (!ret) { |
38516ab5 | 5493 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
8aef2d28 SR |
5494 | if (ret) |
5495 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
5496 | " probe to kernel_sched_switch\n"); | |
5497 | } | |
5498 | ||
f201ae23 FW |
5499 | kfree(ret_stack_list); |
5500 | return ret; | |
5501 | } | |
5502 | ||
4a2b8dda FW |
5503 | /* |
5504 | * Hibernation protection. | |
5505 | * The state of the current task is too much unstable during | |
5506 | * suspend/restore to disk. We want to protect against that. | |
5507 | */ | |
5508 | static int | |
5509 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
5510 | void *unused) | |
5511 | { | |
5512 | switch (state) { | |
5513 | case PM_HIBERNATION_PREPARE: | |
5514 | pause_graph_tracing(); | |
5515 | break; | |
5516 | ||
5517 | case PM_POST_HIBERNATION: | |
5518 | unpause_graph_tracing(); | |
5519 | break; | |
5520 | } | |
5521 | return NOTIFY_DONE; | |
5522 | } | |
5523 | ||
23a8e844 SRRH |
5524 | static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace) |
5525 | { | |
5526 | if (!ftrace_ops_test(&global_ops, trace->func, NULL)) | |
5527 | return 0; | |
5528 | return __ftrace_graph_entry(trace); | |
5529 | } | |
5530 | ||
5531 | /* | |
5532 | * The function graph tracer should only trace the functions defined | |
5533 | * by set_ftrace_filter and set_ftrace_notrace. If another function | |
5534 | * tracer ops is registered, the graph tracer requires testing the | |
5535 | * function against the global ops, and not just trace any function | |
5536 | * that any ftrace_ops registered. | |
5537 | */ | |
5538 | static void update_function_graph_func(void) | |
5539 | { | |
5f151b24 SRRH |
5540 | struct ftrace_ops *op; |
5541 | bool do_test = false; | |
5542 | ||
5543 | /* | |
5544 | * The graph and global ops share the same set of functions | |
5545 | * to test. If any other ops is on the list, then | |
5546 | * the graph tracing needs to test if its the function | |
5547 | * it should call. | |
5548 | */ | |
5549 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
5550 | if (op != &global_ops && op != &graph_ops && | |
5551 | op != &ftrace_list_end) { | |
5552 | do_test = true; | |
5553 | /* in double loop, break out with goto */ | |
5554 | goto out; | |
5555 | } | |
5556 | } while_for_each_ftrace_op(op); | |
5557 | out: | |
5558 | if (do_test) | |
23a8e844 | 5559 | ftrace_graph_entry = ftrace_graph_entry_test; |
5f151b24 SRRH |
5560 | else |
5561 | ftrace_graph_entry = __ftrace_graph_entry; | |
23a8e844 SRRH |
5562 | } |
5563 | ||
8275f69f MK |
5564 | static struct notifier_block ftrace_suspend_notifier = { |
5565 | .notifier_call = ftrace_suspend_notifier_call, | |
5566 | }; | |
5567 | ||
287b6e68 FW |
5568 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
5569 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 5570 | { |
e7d3737e FW |
5571 | int ret = 0; |
5572 | ||
e6ea44e9 | 5573 | mutex_lock(&ftrace_lock); |
e7d3737e | 5574 | |
05ce5818 | 5575 | /* we currently allow only one tracer registered at a time */ |
597af815 | 5576 | if (ftrace_graph_active) { |
05ce5818 SR |
5577 | ret = -EBUSY; |
5578 | goto out; | |
5579 | } | |
5580 | ||
4a2b8dda FW |
5581 | register_pm_notifier(&ftrace_suspend_notifier); |
5582 | ||
597af815 | 5583 | ftrace_graph_active++; |
fb52607a | 5584 | ret = start_graph_tracing(); |
f201ae23 | 5585 | if (ret) { |
597af815 | 5586 | ftrace_graph_active--; |
f201ae23 FW |
5587 | goto out; |
5588 | } | |
e53a6319 | 5589 | |
287b6e68 | 5590 | ftrace_graph_return = retfunc; |
23a8e844 SRRH |
5591 | |
5592 | /* | |
5593 | * Update the indirect function to the entryfunc, and the | |
5594 | * function that gets called to the entry_test first. Then | |
5595 | * call the update fgraph entry function to determine if | |
5596 | * the entryfunc should be called directly or not. | |
5597 | */ | |
5598 | __ftrace_graph_entry = entryfunc; | |
5599 | ftrace_graph_entry = ftrace_graph_entry_test; | |
5600 | update_function_graph_func(); | |
e53a6319 | 5601 | |
5f151b24 | 5602 | ret = ftrace_startup(&graph_ops, FTRACE_START_FUNC_RET); |
e7d3737e | 5603 | out: |
e6ea44e9 | 5604 | mutex_unlock(&ftrace_lock); |
e7d3737e | 5605 | return ret; |
15e6cb36 FW |
5606 | } |
5607 | ||
fb52607a | 5608 | void unregister_ftrace_graph(void) |
15e6cb36 | 5609 | { |
e6ea44e9 | 5610 | mutex_lock(&ftrace_lock); |
e7d3737e | 5611 | |
597af815 | 5612 | if (unlikely(!ftrace_graph_active)) |
2aad1b76 SR |
5613 | goto out; |
5614 | ||
597af815 | 5615 | ftrace_graph_active--; |
287b6e68 | 5616 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 5617 | ftrace_graph_entry = ftrace_graph_entry_stub; |
23a8e844 | 5618 | __ftrace_graph_entry = ftrace_graph_entry_stub; |
5f151b24 | 5619 | ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET); |
4a2b8dda | 5620 | unregister_pm_notifier(&ftrace_suspend_notifier); |
38516ab5 | 5621 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
e7d3737e | 5622 | |
f3bea491 SRRH |
5623 | #ifdef CONFIG_DYNAMIC_FTRACE |
5624 | /* | |
5625 | * Function graph does not allocate the trampoline, but | |
5626 | * other global_ops do. We need to reset the ALLOC_TRAMP flag | |
5627 | * if one was used. | |
5628 | */ | |
5629 | global_ops.trampoline = save_global_trampoline; | |
5630 | if (save_global_flags & FTRACE_OPS_FL_ALLOC_TRAMP) | |
5631 | global_ops.flags |= FTRACE_OPS_FL_ALLOC_TRAMP; | |
5632 | #endif | |
5633 | ||
2aad1b76 | 5634 | out: |
e6ea44e9 | 5635 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 5636 | } |
f201ae23 | 5637 | |
868baf07 SR |
5638 | static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack); |
5639 | ||
5640 | static void | |
5641 | graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack) | |
5642 | { | |
5643 | atomic_set(&t->tracing_graph_pause, 0); | |
5644 | atomic_set(&t->trace_overrun, 0); | |
5645 | t->ftrace_timestamp = 0; | |
25985edc | 5646 | /* make curr_ret_stack visible before we add the ret_stack */ |
868baf07 SR |
5647 | smp_wmb(); |
5648 | t->ret_stack = ret_stack; | |
5649 | } | |
5650 | ||
5651 | /* | |
5652 | * Allocate a return stack for the idle task. May be the first | |
5653 | * time through, or it may be done by CPU hotplug online. | |
5654 | */ | |
5655 | void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) | |
5656 | { | |
5657 | t->curr_ret_stack = -1; | |
5658 | /* | |
5659 | * The idle task has no parent, it either has its own | |
5660 | * stack or no stack at all. | |
5661 | */ | |
5662 | if (t->ret_stack) | |
5663 | WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu)); | |
5664 | ||
5665 | if (ftrace_graph_active) { | |
5666 | struct ftrace_ret_stack *ret_stack; | |
5667 | ||
5668 | ret_stack = per_cpu(idle_ret_stack, cpu); | |
5669 | if (!ret_stack) { | |
5670 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
5671 | * sizeof(struct ftrace_ret_stack), | |
5672 | GFP_KERNEL); | |
5673 | if (!ret_stack) | |
5674 | return; | |
5675 | per_cpu(idle_ret_stack, cpu) = ret_stack; | |
5676 | } | |
5677 | graph_init_task(t, ret_stack); | |
5678 | } | |
5679 | } | |
5680 | ||
f201ae23 | 5681 | /* Allocate a return stack for newly created task */ |
fb52607a | 5682 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 5683 | { |
84047e36 SR |
5684 | /* Make sure we do not use the parent ret_stack */ |
5685 | t->ret_stack = NULL; | |
ea14eb71 | 5686 | t->curr_ret_stack = -1; |
84047e36 | 5687 | |
597af815 | 5688 | if (ftrace_graph_active) { |
82310a32 SR |
5689 | struct ftrace_ret_stack *ret_stack; |
5690 | ||
5691 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
f201ae23 FW |
5692 | * sizeof(struct ftrace_ret_stack), |
5693 | GFP_KERNEL); | |
82310a32 | 5694 | if (!ret_stack) |
f201ae23 | 5695 | return; |
868baf07 | 5696 | graph_init_task(t, ret_stack); |
84047e36 | 5697 | } |
f201ae23 FW |
5698 | } |
5699 | ||
fb52607a | 5700 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 5701 | { |
eae849ca FW |
5702 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
5703 | ||
f201ae23 | 5704 | t->ret_stack = NULL; |
eae849ca FW |
5705 | /* NULL must become visible to IRQs before we free it: */ |
5706 | barrier(); | |
5707 | ||
5708 | kfree(ret_stack); | |
f201ae23 | 5709 | } |
15e6cb36 | 5710 | #endif |