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> |
8434dc93 | 21 | #include <linux/tracefs.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 | ||
e3eea140 SRRH |
101 | static bool ftrace_pids_enabled(void) |
102 | { | |
103 | return !list_empty(&ftrace_pids); | |
104 | } | |
105 | ||
106 | static void ftrace_update_trampoline(struct ftrace_ops *ops); | |
107 | ||
4eebcc81 SR |
108 | /* |
109 | * ftrace_disabled is set when an anomaly is discovered. | |
110 | * ftrace_disabled is much stronger than ftrace_enabled. | |
111 | */ | |
112 | static int ftrace_disabled __read_mostly; | |
113 | ||
52baf119 | 114 | static DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 115 | |
e248491a | 116 | static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end; |
b848914c | 117 | static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end; |
16444a8a | 118 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
2b499381 | 119 | static struct ftrace_ops global_ops; |
e248491a | 120 | static struct ftrace_ops control_ops; |
16444a8a | 121 | |
f1ff6348 SRRH |
122 | static void ftrace_ops_recurs_func(unsigned long ip, unsigned long parent_ip, |
123 | struct ftrace_ops *op, struct pt_regs *regs); | |
124 | ||
2f5f6ad9 SR |
125 | #if ARCH_SUPPORTS_FTRACE_OPS |
126 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 127 | struct ftrace_ops *op, struct pt_regs *regs); |
2f5f6ad9 SR |
128 | #else |
129 | /* See comment below, where ftrace_ops_list_func is defined */ | |
130 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip); | |
131 | #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops) | |
132 | #endif | |
b848914c | 133 | |
0a016409 SR |
134 | /* |
135 | * Traverse the ftrace_global_list, invoking all entries. The reason that we | |
1bb539ca | 136 | * can use rcu_dereference_raw_notrace() is that elements removed from this list |
0a016409 | 137 | * are simply leaked, so there is no need to interact with a grace-period |
1bb539ca | 138 | * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle |
0a016409 SR |
139 | * concurrent insertions into the ftrace_global_list. |
140 | * | |
141 | * Silly Alpha and silly pointer-speculation compiler optimizations! | |
142 | */ | |
143 | #define do_for_each_ftrace_op(op, list) \ | |
1bb539ca | 144 | op = rcu_dereference_raw_notrace(list); \ |
0a016409 SR |
145 | do |
146 | ||
147 | /* | |
148 | * Optimized for just a single item in the list (as that is the normal case). | |
149 | */ | |
150 | #define while_for_each_ftrace_op(op) \ | |
1bb539ca | 151 | while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \ |
0a016409 SR |
152 | unlikely((op) != &ftrace_list_end)) |
153 | ||
f04f24fb MH |
154 | static inline void ftrace_ops_init(struct ftrace_ops *ops) |
155 | { | |
156 | #ifdef CONFIG_DYNAMIC_FTRACE | |
157 | if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) { | |
33b7f99c SRRH |
158 | mutex_init(&ops->local_hash.regex_lock); |
159 | ops->func_hash = &ops->local_hash; | |
f04f24fb MH |
160 | ops->flags |= FTRACE_OPS_FL_INITIALIZED; |
161 | } | |
162 | #endif | |
163 | } | |
164 | ||
ea701f11 SR |
165 | /** |
166 | * ftrace_nr_registered_ops - return number of ops registered | |
167 | * | |
168 | * Returns the number of ftrace_ops registered and tracing functions | |
169 | */ | |
170 | int ftrace_nr_registered_ops(void) | |
171 | { | |
172 | struct ftrace_ops *ops; | |
173 | int cnt = 0; | |
174 | ||
175 | mutex_lock(&ftrace_lock); | |
176 | ||
177 | for (ops = ftrace_ops_list; | |
178 | ops != &ftrace_list_end; ops = ops->next) | |
179 | cnt++; | |
180 | ||
181 | mutex_unlock(&ftrace_lock); | |
182 | ||
183 | return cnt; | |
184 | } | |
185 | ||
2f5f6ad9 | 186 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 187 | struct ftrace_ops *op, struct pt_regs *regs) |
df4fc315 | 188 | { |
0ef8cde5 | 189 | if (!test_tsk_trace_trace(current)) |
df4fc315 SR |
190 | return; |
191 | ||
e3eea140 | 192 | op->saved_func(ip, parent_ip, op, regs); |
df4fc315 SR |
193 | } |
194 | ||
16444a8a | 195 | /** |
3d083395 | 196 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 197 | * |
3d083395 SR |
198 | * This NULLs the ftrace function and in essence stops |
199 | * tracing. There may be lag | |
16444a8a | 200 | */ |
3d083395 | 201 | void clear_ftrace_function(void) |
16444a8a | 202 | { |
3d083395 SR |
203 | ftrace_trace_function = ftrace_stub; |
204 | } | |
205 | ||
e248491a JO |
206 | static void control_ops_disable_all(struct ftrace_ops *ops) |
207 | { | |
208 | int cpu; | |
209 | ||
210 | for_each_possible_cpu(cpu) | |
211 | *per_cpu_ptr(ops->disabled, cpu) = 1; | |
212 | } | |
213 | ||
214 | static int control_ops_alloc(struct ftrace_ops *ops) | |
215 | { | |
216 | int __percpu *disabled; | |
217 | ||
218 | disabled = alloc_percpu(int); | |
219 | if (!disabled) | |
220 | return -ENOMEM; | |
221 | ||
222 | ops->disabled = disabled; | |
223 | control_ops_disable_all(ops); | |
224 | return 0; | |
225 | } | |
226 | ||
405e1d83 SRRH |
227 | static void ftrace_sync(struct work_struct *work) |
228 | { | |
229 | /* | |
230 | * This function is just a stub to implement a hard force | |
231 | * of synchronize_sched(). This requires synchronizing | |
232 | * tasks even in userspace and idle. | |
233 | * | |
234 | * Yes, function tracing is rude. | |
235 | */ | |
236 | } | |
237 | ||
238 | static void ftrace_sync_ipi(void *data) | |
239 | { | |
240 | /* Probably not needed, but do it anyway */ | |
241 | smp_rmb(); | |
242 | } | |
243 | ||
23a8e844 SRRH |
244 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
245 | static void update_function_graph_func(void); | |
246 | #else | |
247 | static inline void update_function_graph_func(void) { } | |
248 | #endif | |
249 | ||
00ccbf2f SRRH |
250 | |
251 | static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops) | |
252 | { | |
253 | /* | |
254 | * If this is a dynamic ops or we force list func, | |
255 | * then it needs to call the list anyway. | |
256 | */ | |
257 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC || FTRACE_FORCE_LIST_FUNC) | |
258 | return ftrace_ops_list_func; | |
259 | ||
260 | return ftrace_ops_get_func(ops); | |
261 | } | |
262 | ||
2b499381 SR |
263 | static void update_ftrace_function(void) |
264 | { | |
265 | ftrace_func_t func; | |
266 | ||
f7aad4e1 SRRH |
267 | /* |
268 | * Prepare the ftrace_ops that the arch callback will use. | |
269 | * If there's only one ftrace_ops registered, the ftrace_ops_list | |
270 | * will point to the ops we want. | |
271 | */ | |
272 | set_function_trace_op = ftrace_ops_list; | |
273 | ||
274 | /* If there's no ftrace_ops registered, just call the stub function */ | |
275 | if (ftrace_ops_list == &ftrace_list_end) { | |
276 | func = ftrace_stub; | |
277 | ||
cdbe61bf SR |
278 | /* |
279 | * If we are at the end of the list and this ops is | |
4740974a SR |
280 | * recursion safe and not dynamic and the arch supports passing ops, |
281 | * then have the mcount trampoline call the function directly. | |
cdbe61bf | 282 | */ |
f7aad4e1 | 283 | } else if (ftrace_ops_list->next == &ftrace_list_end) { |
00ccbf2f | 284 | func = ftrace_ops_get_list_func(ftrace_ops_list); |
f7aad4e1 | 285 | |
2f5f6ad9 SR |
286 | } else { |
287 | /* Just use the default ftrace_ops */ | |
405e1d83 | 288 | set_function_trace_op = &ftrace_list_end; |
b848914c | 289 | func = ftrace_ops_list_func; |
2f5f6ad9 | 290 | } |
2b499381 | 291 | |
5f8bf2d2 SRRH |
292 | update_function_graph_func(); |
293 | ||
405e1d83 SRRH |
294 | /* If there's no change, then do nothing more here */ |
295 | if (ftrace_trace_function == func) | |
296 | return; | |
297 | ||
298 | /* | |
299 | * If we are using the list function, it doesn't care | |
300 | * about the function_trace_ops. | |
301 | */ | |
302 | if (func == ftrace_ops_list_func) { | |
303 | ftrace_trace_function = func; | |
304 | /* | |
305 | * Don't even bother setting function_trace_ops, | |
306 | * it would be racy to do so anyway. | |
307 | */ | |
308 | return; | |
309 | } | |
310 | ||
311 | #ifndef CONFIG_DYNAMIC_FTRACE | |
312 | /* | |
313 | * For static tracing, we need to be a bit more careful. | |
314 | * The function change takes affect immediately. Thus, | |
315 | * we need to coorditate the setting of the function_trace_ops | |
316 | * with the setting of the ftrace_trace_function. | |
317 | * | |
318 | * Set the function to the list ops, which will call the | |
319 | * function we want, albeit indirectly, but it handles the | |
320 | * ftrace_ops and doesn't depend on function_trace_op. | |
321 | */ | |
322 | ftrace_trace_function = ftrace_ops_list_func; | |
323 | /* | |
324 | * Make sure all CPUs see this. Yes this is slow, but static | |
325 | * tracing is slow and nasty to have enabled. | |
326 | */ | |
327 | schedule_on_each_cpu(ftrace_sync); | |
328 | /* Now all cpus are using the list ops. */ | |
329 | function_trace_op = set_function_trace_op; | |
330 | /* Make sure the function_trace_op is visible on all CPUs */ | |
331 | smp_wmb(); | |
332 | /* Nasty way to force a rmb on all cpus */ | |
333 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
334 | /* OK, we are all set to update the ftrace_trace_function now! */ | |
335 | #endif /* !CONFIG_DYNAMIC_FTRACE */ | |
336 | ||
491d0dcf | 337 | ftrace_trace_function = func; |
491d0dcf SR |
338 | } |
339 | ||
7eea4fce JW |
340 | int using_ftrace_ops_list_func(void) |
341 | { | |
342 | return ftrace_trace_function == ftrace_ops_list_func; | |
343 | } | |
344 | ||
2b499381 | 345 | static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
3d083395 | 346 | { |
2b499381 | 347 | ops->next = *list; |
16444a8a | 348 | /* |
b848914c | 349 | * We are entering ops into the list but another |
16444a8a ACM |
350 | * CPU might be walking that list. We need to make sure |
351 | * the ops->next pointer is valid before another CPU sees | |
b848914c | 352 | * the ops pointer included into the list. |
16444a8a | 353 | */ |
2b499381 | 354 | rcu_assign_pointer(*list, ops); |
16444a8a ACM |
355 | } |
356 | ||
2b499381 | 357 | static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
16444a8a | 358 | { |
16444a8a | 359 | struct ftrace_ops **p; |
16444a8a ACM |
360 | |
361 | /* | |
3d083395 SR |
362 | * If we are removing the last function, then simply point |
363 | * to the ftrace_stub. | |
16444a8a | 364 | */ |
2b499381 SR |
365 | if (*list == ops && ops->next == &ftrace_list_end) { |
366 | *list = &ftrace_list_end; | |
e6ea44e9 | 367 | return 0; |
16444a8a ACM |
368 | } |
369 | ||
2b499381 | 370 | for (p = list; *p != &ftrace_list_end; p = &(*p)->next) |
16444a8a ACM |
371 | if (*p == ops) |
372 | break; | |
373 | ||
e6ea44e9 SR |
374 | if (*p != ops) |
375 | return -1; | |
16444a8a ACM |
376 | |
377 | *p = (*p)->next; | |
2b499381 SR |
378 | return 0; |
379 | } | |
16444a8a | 380 | |
e248491a JO |
381 | static void add_ftrace_list_ops(struct ftrace_ops **list, |
382 | struct ftrace_ops *main_ops, | |
383 | struct ftrace_ops *ops) | |
384 | { | |
385 | int first = *list == &ftrace_list_end; | |
386 | add_ftrace_ops(list, ops); | |
387 | if (first) | |
388 | add_ftrace_ops(&ftrace_ops_list, main_ops); | |
389 | } | |
390 | ||
391 | static int remove_ftrace_list_ops(struct ftrace_ops **list, | |
392 | struct ftrace_ops *main_ops, | |
393 | struct ftrace_ops *ops) | |
394 | { | |
395 | int ret = remove_ftrace_ops(list, ops); | |
396 | if (!ret && *list == &ftrace_list_end) | |
397 | ret = remove_ftrace_ops(&ftrace_ops_list, main_ops); | |
398 | return ret; | |
399 | } | |
400 | ||
f3bea491 SRRH |
401 | static void ftrace_update_trampoline(struct ftrace_ops *ops); |
402 | ||
2b499381 SR |
403 | static int __register_ftrace_function(struct ftrace_ops *ops) |
404 | { | |
591dffda SRRH |
405 | if (ops->flags & FTRACE_OPS_FL_DELETED) |
406 | return -EINVAL; | |
407 | ||
b848914c SR |
408 | if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) |
409 | return -EBUSY; | |
410 | ||
06aeaaea | 411 | #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
08f6fba5 SR |
412 | /* |
413 | * If the ftrace_ops specifies SAVE_REGS, then it only can be used | |
414 | * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set. | |
415 | * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant. | |
416 | */ | |
417 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS && | |
418 | !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)) | |
419 | return -EINVAL; | |
420 | ||
421 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED) | |
422 | ops->flags |= FTRACE_OPS_FL_SAVE_REGS; | |
423 | #endif | |
424 | ||
cdbe61bf SR |
425 | if (!core_kernel_data((unsigned long)ops)) |
426 | ops->flags |= FTRACE_OPS_FL_DYNAMIC; | |
427 | ||
4104d326 | 428 | if (ops->flags & FTRACE_OPS_FL_CONTROL) { |
e248491a JO |
429 | if (control_ops_alloc(ops)) |
430 | return -ENOMEM; | |
431 | add_ftrace_list_ops(&ftrace_control_list, &control_ops, ops); | |
fe578ba3 SRRH |
432 | /* The control_ops needs the trampoline update */ |
433 | ops = &control_ops; | |
b848914c SR |
434 | } else |
435 | add_ftrace_ops(&ftrace_ops_list, ops); | |
436 | ||
e3eea140 SRRH |
437 | /* Always save the function, and reset at unregistering */ |
438 | ops->saved_func = ops->func; | |
439 | ||
440 | if (ops->flags & FTRACE_OPS_FL_PID && ftrace_pids_enabled()) | |
441 | ops->func = ftrace_pid_func; | |
442 | ||
f3bea491 SRRH |
443 | ftrace_update_trampoline(ops); |
444 | ||
2b499381 SR |
445 | if (ftrace_enabled) |
446 | update_ftrace_function(); | |
447 | ||
448 | return 0; | |
449 | } | |
450 | ||
451 | static int __unregister_ftrace_function(struct ftrace_ops *ops) | |
452 | { | |
453 | int ret; | |
454 | ||
b848914c SR |
455 | if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) |
456 | return -EBUSY; | |
457 | ||
4104d326 | 458 | if (ops->flags & FTRACE_OPS_FL_CONTROL) { |
e248491a JO |
459 | ret = remove_ftrace_list_ops(&ftrace_control_list, |
460 | &control_ops, ops); | |
b848914c SR |
461 | } else |
462 | ret = remove_ftrace_ops(&ftrace_ops_list, ops); | |
463 | ||
2b499381 SR |
464 | if (ret < 0) |
465 | return ret; | |
b848914c | 466 | |
491d0dcf SR |
467 | if (ftrace_enabled) |
468 | update_ftrace_function(); | |
16444a8a | 469 | |
e3eea140 SRRH |
470 | ops->func = ops->saved_func; |
471 | ||
e6ea44e9 | 472 | return 0; |
3d083395 SR |
473 | } |
474 | ||
df4fc315 SR |
475 | static void ftrace_update_pid_func(void) |
476 | { | |
e3eea140 SRRH |
477 | bool enabled = ftrace_pids_enabled(); |
478 | struct ftrace_ops *op; | |
479 | ||
491d0dcf | 480 | /* Only do something if we are tracing something */ |
df4fc315 | 481 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 482 | return; |
df4fc315 | 483 | |
e3eea140 SRRH |
484 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
485 | if (op->flags & FTRACE_OPS_FL_PID) { | |
486 | op->func = enabled ? ftrace_pid_func : | |
487 | op->saved_func; | |
488 | ftrace_update_trampoline(op); | |
489 | } | |
490 | } while_for_each_ftrace_op(op); | |
491 | ||
491d0dcf | 492 | update_ftrace_function(); |
df4fc315 SR |
493 | } |
494 | ||
493762fc SR |
495 | #ifdef CONFIG_FUNCTION_PROFILER |
496 | struct ftrace_profile { | |
497 | struct hlist_node node; | |
498 | unsigned long ip; | |
499 | unsigned long counter; | |
0706f1c4 SR |
500 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
501 | unsigned long long time; | |
e330b3bc | 502 | unsigned long long time_squared; |
0706f1c4 | 503 | #endif |
8fc0c701 SR |
504 | }; |
505 | ||
493762fc SR |
506 | struct ftrace_profile_page { |
507 | struct ftrace_profile_page *next; | |
508 | unsigned long index; | |
509 | struct ftrace_profile records[]; | |
d61f82d0 SR |
510 | }; |
511 | ||
cafb168a SR |
512 | struct ftrace_profile_stat { |
513 | atomic_t disabled; | |
514 | struct hlist_head *hash; | |
515 | struct ftrace_profile_page *pages; | |
516 | struct ftrace_profile_page *start; | |
517 | struct tracer_stat stat; | |
518 | }; | |
519 | ||
493762fc SR |
520 | #define PROFILE_RECORDS_SIZE \ |
521 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 522 | |
493762fc SR |
523 | #define PROFILES_PER_PAGE \ |
524 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 525 | |
fb9fb015 SR |
526 | static int ftrace_profile_enabled __read_mostly; |
527 | ||
528 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
529 | static DEFINE_MUTEX(ftrace_profile_lock); |
530 | ||
cafb168a | 531 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc | 532 | |
20079ebe NK |
533 | #define FTRACE_PROFILE_HASH_BITS 10 |
534 | #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS) | |
493762fc | 535 | |
bac429f0 SR |
536 | static void * |
537 | function_stat_next(void *v, int idx) | |
538 | { | |
493762fc SR |
539 | struct ftrace_profile *rec = v; |
540 | struct ftrace_profile_page *pg; | |
bac429f0 | 541 | |
493762fc | 542 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
543 | |
544 | again: | |
0296e425 LZ |
545 | if (idx != 0) |
546 | rec++; | |
547 | ||
bac429f0 SR |
548 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
549 | pg = pg->next; | |
550 | if (!pg) | |
551 | return NULL; | |
552 | rec = &pg->records[0]; | |
493762fc SR |
553 | if (!rec->counter) |
554 | goto again; | |
bac429f0 SR |
555 | } |
556 | ||
bac429f0 SR |
557 | return rec; |
558 | } | |
559 | ||
560 | static void *function_stat_start(struct tracer_stat *trace) | |
561 | { | |
cafb168a SR |
562 | struct ftrace_profile_stat *stat = |
563 | container_of(trace, struct ftrace_profile_stat, stat); | |
564 | ||
565 | if (!stat || !stat->start) | |
566 | return NULL; | |
567 | ||
568 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
569 | } |
570 | ||
0706f1c4 SR |
571 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
572 | /* function graph compares on total time */ | |
573 | static int function_stat_cmp(void *p1, void *p2) | |
574 | { | |
575 | struct ftrace_profile *a = p1; | |
576 | struct ftrace_profile *b = p2; | |
577 | ||
578 | if (a->time < b->time) | |
579 | return -1; | |
580 | if (a->time > b->time) | |
581 | return 1; | |
582 | else | |
583 | return 0; | |
584 | } | |
585 | #else | |
586 | /* not function graph compares against hits */ | |
bac429f0 SR |
587 | static int function_stat_cmp(void *p1, void *p2) |
588 | { | |
493762fc SR |
589 | struct ftrace_profile *a = p1; |
590 | struct ftrace_profile *b = p2; | |
bac429f0 SR |
591 | |
592 | if (a->counter < b->counter) | |
593 | return -1; | |
594 | if (a->counter > b->counter) | |
595 | return 1; | |
596 | else | |
597 | return 0; | |
598 | } | |
0706f1c4 | 599 | #endif |
bac429f0 SR |
600 | |
601 | static int function_stat_headers(struct seq_file *m) | |
602 | { | |
0706f1c4 | 603 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
fa6f0cc7 RV |
604 | seq_puts(m, " Function " |
605 | "Hit Time Avg s^2\n" | |
606 | " -------- " | |
607 | "--- ---- --- ---\n"); | |
0706f1c4 | 608 | #else |
fa6f0cc7 RV |
609 | seq_puts(m, " Function Hit\n" |
610 | " -------- ---\n"); | |
0706f1c4 | 611 | #endif |
bac429f0 SR |
612 | return 0; |
613 | } | |
614 | ||
615 | static int function_stat_show(struct seq_file *m, void *v) | |
616 | { | |
493762fc | 617 | struct ftrace_profile *rec = v; |
bac429f0 | 618 | char str[KSYM_SYMBOL_LEN]; |
3aaba20f | 619 | int ret = 0; |
0706f1c4 | 620 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
621 | static struct trace_seq s; |
622 | unsigned long long avg; | |
e330b3bc | 623 | unsigned long long stddev; |
0706f1c4 | 624 | #endif |
3aaba20f LZ |
625 | mutex_lock(&ftrace_profile_lock); |
626 | ||
627 | /* we raced with function_profile_reset() */ | |
628 | if (unlikely(rec->counter == 0)) { | |
629 | ret = -EBUSY; | |
630 | goto out; | |
631 | } | |
bac429f0 SR |
632 | |
633 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
0706f1c4 SR |
634 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
635 | ||
636 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
fa6f0cc7 | 637 | seq_puts(m, " "); |
34886c8b SR |
638 | avg = rec->time; |
639 | do_div(avg, rec->counter); | |
640 | ||
e330b3bc CD |
641 | /* Sample standard deviation (s^2) */ |
642 | if (rec->counter <= 1) | |
643 | stddev = 0; | |
644 | else { | |
52d85d76 JL |
645 | /* |
646 | * Apply Welford's method: | |
647 | * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2) | |
648 | */ | |
649 | stddev = rec->counter * rec->time_squared - | |
650 | rec->time * rec->time; | |
651 | ||
e330b3bc CD |
652 | /* |
653 | * Divide only 1000 for ns^2 -> us^2 conversion. | |
654 | * trace_print_graph_duration will divide 1000 again. | |
655 | */ | |
52d85d76 | 656 | do_div(stddev, rec->counter * (rec->counter - 1) * 1000); |
e330b3bc CD |
657 | } |
658 | ||
34886c8b SR |
659 | trace_seq_init(&s); |
660 | trace_print_graph_duration(rec->time, &s); | |
661 | trace_seq_puts(&s, " "); | |
662 | trace_print_graph_duration(avg, &s); | |
e330b3bc CD |
663 | trace_seq_puts(&s, " "); |
664 | trace_print_graph_duration(stddev, &s); | |
0706f1c4 | 665 | trace_print_seq(m, &s); |
0706f1c4 SR |
666 | #endif |
667 | seq_putc(m, '\n'); | |
3aaba20f LZ |
668 | out: |
669 | mutex_unlock(&ftrace_profile_lock); | |
bac429f0 | 670 | |
3aaba20f | 671 | return ret; |
bac429f0 SR |
672 | } |
673 | ||
cafb168a | 674 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 675 | { |
493762fc | 676 | struct ftrace_profile_page *pg; |
bac429f0 | 677 | |
cafb168a | 678 | pg = stat->pages = stat->start; |
bac429f0 | 679 | |
493762fc SR |
680 | while (pg) { |
681 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
682 | pg->index = 0; | |
683 | pg = pg->next; | |
bac429f0 SR |
684 | } |
685 | ||
cafb168a | 686 | memset(stat->hash, 0, |
493762fc SR |
687 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
688 | } | |
bac429f0 | 689 | |
cafb168a | 690 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
691 | { |
692 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
693 | int functions; |
694 | int pages; | |
493762fc | 695 | int i; |
bac429f0 | 696 | |
493762fc | 697 | /* If we already allocated, do nothing */ |
cafb168a | 698 | if (stat->pages) |
493762fc | 699 | return 0; |
bac429f0 | 700 | |
cafb168a SR |
701 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
702 | if (!stat->pages) | |
493762fc | 703 | return -ENOMEM; |
bac429f0 | 704 | |
318e0a73 SR |
705 | #ifdef CONFIG_DYNAMIC_FTRACE |
706 | functions = ftrace_update_tot_cnt; | |
707 | #else | |
708 | /* | |
709 | * We do not know the number of functions that exist because | |
710 | * dynamic tracing is what counts them. With past experience | |
711 | * we have around 20K functions. That should be more than enough. | |
712 | * It is highly unlikely we will execute every function in | |
713 | * the kernel. | |
714 | */ | |
715 | functions = 20000; | |
716 | #endif | |
717 | ||
cafb168a | 718 | pg = stat->start = stat->pages; |
bac429f0 | 719 | |
318e0a73 SR |
720 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
721 | ||
39e30cd1 | 722 | for (i = 1; i < pages; i++) { |
493762fc | 723 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 724 | if (!pg->next) |
318e0a73 | 725 | goto out_free; |
493762fc SR |
726 | pg = pg->next; |
727 | } | |
728 | ||
729 | return 0; | |
318e0a73 SR |
730 | |
731 | out_free: | |
732 | pg = stat->start; | |
733 | while (pg) { | |
734 | unsigned long tmp = (unsigned long)pg; | |
735 | ||
736 | pg = pg->next; | |
737 | free_page(tmp); | |
738 | } | |
739 | ||
318e0a73 SR |
740 | stat->pages = NULL; |
741 | stat->start = NULL; | |
742 | ||
743 | return -ENOMEM; | |
bac429f0 SR |
744 | } |
745 | ||
cafb168a | 746 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 747 | { |
cafb168a | 748 | struct ftrace_profile_stat *stat; |
493762fc | 749 | int size; |
bac429f0 | 750 | |
cafb168a SR |
751 | stat = &per_cpu(ftrace_profile_stats, cpu); |
752 | ||
753 | if (stat->hash) { | |
493762fc | 754 | /* If the profile is already created, simply reset it */ |
cafb168a | 755 | ftrace_profile_reset(stat); |
493762fc SR |
756 | return 0; |
757 | } | |
bac429f0 | 758 | |
493762fc SR |
759 | /* |
760 | * We are profiling all functions, but usually only a few thousand | |
761 | * functions are hit. We'll make a hash of 1024 items. | |
762 | */ | |
763 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 764 | |
cafb168a | 765 | stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
493762fc | 766 | |
cafb168a | 767 | if (!stat->hash) |
493762fc SR |
768 | return -ENOMEM; |
769 | ||
318e0a73 | 770 | /* Preallocate the function profiling pages */ |
cafb168a SR |
771 | if (ftrace_profile_pages_init(stat) < 0) { |
772 | kfree(stat->hash); | |
773 | stat->hash = NULL; | |
493762fc SR |
774 | return -ENOMEM; |
775 | } | |
776 | ||
777 | return 0; | |
bac429f0 SR |
778 | } |
779 | ||
cafb168a SR |
780 | static int ftrace_profile_init(void) |
781 | { | |
782 | int cpu; | |
783 | int ret = 0; | |
784 | ||
c4602c1c | 785 | for_each_possible_cpu(cpu) { |
cafb168a SR |
786 | ret = ftrace_profile_init_cpu(cpu); |
787 | if (ret) | |
788 | break; | |
789 | } | |
790 | ||
791 | return ret; | |
792 | } | |
793 | ||
493762fc | 794 | /* interrupts must be disabled */ |
cafb168a SR |
795 | static struct ftrace_profile * |
796 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 797 | { |
493762fc | 798 | struct ftrace_profile *rec; |
bac429f0 | 799 | struct hlist_head *hhd; |
bac429f0 SR |
800 | unsigned long key; |
801 | ||
20079ebe | 802 | key = hash_long(ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 803 | hhd = &stat->hash[key]; |
bac429f0 SR |
804 | |
805 | if (hlist_empty(hhd)) | |
806 | return NULL; | |
807 | ||
1bb539ca | 808 | hlist_for_each_entry_rcu_notrace(rec, hhd, node) { |
bac429f0 | 809 | if (rec->ip == ip) |
493762fc SR |
810 | return rec; |
811 | } | |
812 | ||
813 | return NULL; | |
814 | } | |
815 | ||
cafb168a SR |
816 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
817 | struct ftrace_profile *rec) | |
493762fc SR |
818 | { |
819 | unsigned long key; | |
820 | ||
20079ebe | 821 | key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 822 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
823 | } |
824 | ||
318e0a73 SR |
825 | /* |
826 | * The memory is already allocated, this simply finds a new record to use. | |
827 | */ | |
493762fc | 828 | static struct ftrace_profile * |
318e0a73 | 829 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
830 | { |
831 | struct ftrace_profile *rec = NULL; | |
832 | ||
318e0a73 | 833 | /* prevent recursion (from NMIs) */ |
cafb168a | 834 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
835 | goto out; |
836 | ||
493762fc | 837 | /* |
318e0a73 SR |
838 | * Try to find the function again since an NMI |
839 | * could have added it | |
493762fc | 840 | */ |
cafb168a | 841 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 842 | if (rec) |
cafb168a | 843 | goto out; |
493762fc | 844 | |
cafb168a SR |
845 | if (stat->pages->index == PROFILES_PER_PAGE) { |
846 | if (!stat->pages->next) | |
847 | goto out; | |
848 | stat->pages = stat->pages->next; | |
bac429f0 | 849 | } |
493762fc | 850 | |
cafb168a | 851 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 852 | rec->ip = ip; |
cafb168a | 853 | ftrace_add_profile(stat, rec); |
493762fc | 854 | |
bac429f0 | 855 | out: |
cafb168a | 856 | atomic_dec(&stat->disabled); |
bac429f0 SR |
857 | |
858 | return rec; | |
859 | } | |
860 | ||
861 | static void | |
2f5f6ad9 | 862 | function_profile_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 863 | struct ftrace_ops *ops, struct pt_regs *regs) |
bac429f0 | 864 | { |
cafb168a | 865 | struct ftrace_profile_stat *stat; |
493762fc | 866 | struct ftrace_profile *rec; |
bac429f0 SR |
867 | unsigned long flags; |
868 | ||
869 | if (!ftrace_profile_enabled) | |
870 | return; | |
871 | ||
872 | local_irq_save(flags); | |
cafb168a | 873 | |
bdffd893 | 874 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 875 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
876 | goto out; |
877 | ||
878 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 879 | if (!rec) { |
318e0a73 | 880 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
881 | if (!rec) |
882 | goto out; | |
883 | } | |
bac429f0 SR |
884 | |
885 | rec->counter++; | |
886 | out: | |
887 | local_irq_restore(flags); | |
888 | } | |
889 | ||
0706f1c4 SR |
890 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
891 | static int profile_graph_entry(struct ftrace_graph_ent *trace) | |
892 | { | |
a1e2e31d | 893 | function_profile_call(trace->func, 0, NULL, NULL); |
0706f1c4 SR |
894 | return 1; |
895 | } | |
896 | ||
897 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
898 | { | |
cafb168a | 899 | struct ftrace_profile_stat *stat; |
a2a16d6a | 900 | unsigned long long calltime; |
0706f1c4 | 901 | struct ftrace_profile *rec; |
cafb168a | 902 | unsigned long flags; |
0706f1c4 SR |
903 | |
904 | local_irq_save(flags); | |
bdffd893 | 905 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 906 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
907 | goto out; |
908 | ||
37e44bc5 SR |
909 | /* If the calltime was zero'd ignore it */ |
910 | if (!trace->calltime) | |
911 | goto out; | |
912 | ||
a2a16d6a SR |
913 | calltime = trace->rettime - trace->calltime; |
914 | ||
915 | if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) { | |
916 | int index; | |
917 | ||
918 | index = trace->depth; | |
919 | ||
920 | /* Append this call time to the parent time to subtract */ | |
921 | if (index) | |
922 | current->ret_stack[index - 1].subtime += calltime; | |
923 | ||
924 | if (current->ret_stack[index].subtime < calltime) | |
925 | calltime -= current->ret_stack[index].subtime; | |
926 | else | |
927 | calltime = 0; | |
928 | } | |
929 | ||
cafb168a | 930 | rec = ftrace_find_profiled_func(stat, trace->func); |
e330b3bc | 931 | if (rec) { |
a2a16d6a | 932 | rec->time += calltime; |
e330b3bc CD |
933 | rec->time_squared += calltime * calltime; |
934 | } | |
a2a16d6a | 935 | |
cafb168a | 936 | out: |
0706f1c4 SR |
937 | local_irq_restore(flags); |
938 | } | |
939 | ||
940 | static int register_ftrace_profiler(void) | |
941 | { | |
942 | return register_ftrace_graph(&profile_graph_return, | |
943 | &profile_graph_entry); | |
944 | } | |
945 | ||
946 | static void unregister_ftrace_profiler(void) | |
947 | { | |
948 | unregister_ftrace_graph(); | |
949 | } | |
950 | #else | |
bd38c0e6 | 951 | static struct ftrace_ops ftrace_profile_ops __read_mostly = { |
fb9fb015 | 952 | .func = function_profile_call, |
f04f24fb | 953 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, |
33b7f99c | 954 | INIT_OPS_HASH(ftrace_profile_ops) |
bac429f0 SR |
955 | }; |
956 | ||
0706f1c4 SR |
957 | static int register_ftrace_profiler(void) |
958 | { | |
959 | return register_ftrace_function(&ftrace_profile_ops); | |
960 | } | |
961 | ||
962 | static void unregister_ftrace_profiler(void) | |
963 | { | |
964 | unregister_ftrace_function(&ftrace_profile_ops); | |
965 | } | |
966 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
967 | ||
bac429f0 SR |
968 | static ssize_t |
969 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
970 | size_t cnt, loff_t *ppos) | |
971 | { | |
972 | unsigned long val; | |
bac429f0 SR |
973 | int ret; |
974 | ||
22fe9b54 PH |
975 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
976 | if (ret) | |
bac429f0 SR |
977 | return ret; |
978 | ||
979 | val = !!val; | |
980 | ||
981 | mutex_lock(&ftrace_profile_lock); | |
982 | if (ftrace_profile_enabled ^ val) { | |
983 | if (val) { | |
493762fc SR |
984 | ret = ftrace_profile_init(); |
985 | if (ret < 0) { | |
986 | cnt = ret; | |
987 | goto out; | |
988 | } | |
989 | ||
0706f1c4 SR |
990 | ret = register_ftrace_profiler(); |
991 | if (ret < 0) { | |
992 | cnt = ret; | |
993 | goto out; | |
994 | } | |
bac429f0 SR |
995 | ftrace_profile_enabled = 1; |
996 | } else { | |
997 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
998 | /* |
999 | * unregister_ftrace_profiler calls stop_machine | |
1000 | * so this acts like an synchronize_sched. | |
1001 | */ | |
0706f1c4 | 1002 | unregister_ftrace_profiler(); |
bac429f0 SR |
1003 | } |
1004 | } | |
493762fc | 1005 | out: |
bac429f0 SR |
1006 | mutex_unlock(&ftrace_profile_lock); |
1007 | ||
cf8517cf | 1008 | *ppos += cnt; |
bac429f0 SR |
1009 | |
1010 | return cnt; | |
1011 | } | |
1012 | ||
493762fc SR |
1013 | static ssize_t |
1014 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
1015 | size_t cnt, loff_t *ppos) | |
1016 | { | |
fb9fb015 | 1017 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
1018 | int r; |
1019 | ||
1020 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
1021 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
1022 | } | |
1023 | ||
bac429f0 SR |
1024 | static const struct file_operations ftrace_profile_fops = { |
1025 | .open = tracing_open_generic, | |
1026 | .read = ftrace_profile_read, | |
1027 | .write = ftrace_profile_write, | |
6038f373 | 1028 | .llseek = default_llseek, |
bac429f0 SR |
1029 | }; |
1030 | ||
cafb168a SR |
1031 | /* used to initialize the real stat files */ |
1032 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
1033 | .name = "functions", |
1034 | .stat_start = function_stat_start, | |
1035 | .stat_next = function_stat_next, | |
1036 | .stat_cmp = function_stat_cmp, | |
1037 | .stat_headers = function_stat_headers, | |
1038 | .stat_show = function_stat_show | |
cafb168a SR |
1039 | }; |
1040 | ||
8434dc93 | 1041 | static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
bac429f0 | 1042 | { |
cafb168a | 1043 | struct ftrace_profile_stat *stat; |
bac429f0 | 1044 | struct dentry *entry; |
cafb168a | 1045 | char *name; |
bac429f0 | 1046 | int ret; |
cafb168a SR |
1047 | int cpu; |
1048 | ||
1049 | for_each_possible_cpu(cpu) { | |
1050 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
1051 | ||
1052 | /* allocate enough for function name + cpu number */ | |
1053 | name = kmalloc(32, GFP_KERNEL); | |
1054 | if (!name) { | |
1055 | /* | |
1056 | * The files created are permanent, if something happens | |
1057 | * we still do not free memory. | |
1058 | */ | |
cafb168a SR |
1059 | WARN(1, |
1060 | "Could not allocate stat file for cpu %d\n", | |
1061 | cpu); | |
1062 | return; | |
1063 | } | |
1064 | stat->stat = function_stats; | |
1065 | snprintf(name, 32, "function%d", cpu); | |
1066 | stat->stat.name = name; | |
1067 | ret = register_stat_tracer(&stat->stat); | |
1068 | if (ret) { | |
1069 | WARN(1, | |
1070 | "Could not register function stat for cpu %d\n", | |
1071 | cpu); | |
1072 | kfree(name); | |
1073 | return; | |
1074 | } | |
bac429f0 SR |
1075 | } |
1076 | ||
8434dc93 | 1077 | entry = tracefs_create_file("function_profile_enabled", 0644, |
bac429f0 SR |
1078 | d_tracer, NULL, &ftrace_profile_fops); |
1079 | if (!entry) | |
8434dc93 | 1080 | pr_warning("Could not create tracefs " |
bac429f0 SR |
1081 | "'function_profile_enabled' entry\n"); |
1082 | } | |
1083 | ||
bac429f0 | 1084 | #else /* CONFIG_FUNCTION_PROFILER */ |
8434dc93 | 1085 | static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
bac429f0 SR |
1086 | { |
1087 | } | |
bac429f0 SR |
1088 | #endif /* CONFIG_FUNCTION_PROFILER */ |
1089 | ||
493762fc SR |
1090 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; |
1091 | ||
1619dc3f PA |
1092 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
1093 | static int ftrace_graph_active; | |
1094 | #else | |
1095 | # define ftrace_graph_active 0 | |
1096 | #endif | |
1097 | ||
493762fc SR |
1098 | #ifdef CONFIG_DYNAMIC_FTRACE |
1099 | ||
79922b80 SRRH |
1100 | static struct ftrace_ops *removed_ops; |
1101 | ||
e1effa01 SRRH |
1102 | /* |
1103 | * Set when doing a global update, like enabling all recs or disabling them. | |
1104 | * It is not set when just updating a single ftrace_ops. | |
1105 | */ | |
1106 | static bool update_all_ops; | |
1107 | ||
493762fc SR |
1108 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
1109 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
1110 | #endif | |
1111 | ||
1112 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; | |
1113 | ||
1114 | struct ftrace_func_probe { | |
1115 | struct hlist_node node; | |
1116 | struct ftrace_probe_ops *ops; | |
1117 | unsigned long flags; | |
1118 | unsigned long ip; | |
1119 | void *data; | |
7818b388 | 1120 | struct list_head free_list; |
493762fc SR |
1121 | }; |
1122 | ||
b448c4e3 SR |
1123 | struct ftrace_func_entry { |
1124 | struct hlist_node hlist; | |
1125 | unsigned long ip; | |
1126 | }; | |
1127 | ||
1128 | struct ftrace_hash { | |
1129 | unsigned long size_bits; | |
1130 | struct hlist_head *buckets; | |
1131 | unsigned long count; | |
07fd5515 | 1132 | struct rcu_head rcu; |
b448c4e3 SR |
1133 | }; |
1134 | ||
33dc9b12 SR |
1135 | /* |
1136 | * We make these constant because no one should touch them, | |
1137 | * but they are used as the default "empty hash", to avoid allocating | |
1138 | * it all the time. These are in a read only section such that if | |
1139 | * anyone does try to modify it, it will cause an exception. | |
1140 | */ | |
1141 | static const struct hlist_head empty_buckets[1]; | |
1142 | static const struct ftrace_hash empty_hash = { | |
1143 | .buckets = (struct hlist_head *)empty_buckets, | |
1cf41dd7 | 1144 | }; |
33dc9b12 | 1145 | #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash) |
493762fc | 1146 | |
2b499381 | 1147 | static struct ftrace_ops global_ops = { |
33b7f99c SRRH |
1148 | .func = ftrace_stub, |
1149 | .local_hash.notrace_hash = EMPTY_HASH, | |
1150 | .local_hash.filter_hash = EMPTY_HASH, | |
1151 | INIT_OPS_HASH(global_ops) | |
1152 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | | |
e3eea140 SRRH |
1153 | FTRACE_OPS_FL_INITIALIZED | |
1154 | FTRACE_OPS_FL_PID, | |
f45948e8 SR |
1155 | }; |
1156 | ||
aec0be2d SRRH |
1157 | /* |
1158 | * This is used by __kernel_text_address() to return true if the | |
0af26492 | 1159 | * address is on a dynamically allocated trampoline that would |
aec0be2d SRRH |
1160 | * not return true for either core_kernel_text() or |
1161 | * is_module_text_address(). | |
1162 | */ | |
1163 | bool is_ftrace_trampoline(unsigned long addr) | |
1164 | { | |
1165 | struct ftrace_ops *op; | |
1166 | bool ret = false; | |
1167 | ||
1168 | /* | |
1169 | * Some of the ops may be dynamically allocated, | |
1170 | * they are freed after a synchronize_sched(). | |
1171 | */ | |
1172 | preempt_disable_notrace(); | |
1173 | ||
1174 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1175 | /* | |
1176 | * This is to check for dynamically allocated trampolines. | |
1177 | * Trampolines that are in kernel text will have | |
1178 | * core_kernel_text() return true. | |
1179 | */ | |
1180 | if (op->trampoline && op->trampoline_size) | |
1181 | if (addr >= op->trampoline && | |
1182 | addr < op->trampoline + op->trampoline_size) { | |
1183 | ret = true; | |
1184 | goto out; | |
1185 | } | |
1186 | } while_for_each_ftrace_op(op); | |
1187 | ||
1188 | out: | |
1189 | preempt_enable_notrace(); | |
1190 | ||
1191 | return ret; | |
1192 | } | |
1193 | ||
493762fc SR |
1194 | struct ftrace_page { |
1195 | struct ftrace_page *next; | |
a7900875 | 1196 | struct dyn_ftrace *records; |
493762fc | 1197 | int index; |
a7900875 | 1198 | int size; |
493762fc SR |
1199 | }; |
1200 | ||
a7900875 SR |
1201 | #define ENTRY_SIZE sizeof(struct dyn_ftrace) |
1202 | #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE) | |
493762fc SR |
1203 | |
1204 | /* estimate from running different kernels */ | |
1205 | #define NR_TO_INIT 10000 | |
1206 | ||
1207 | static struct ftrace_page *ftrace_pages_start; | |
1208 | static struct ftrace_page *ftrace_pages; | |
1209 | ||
68f40969 | 1210 | static bool __always_inline ftrace_hash_empty(struct ftrace_hash *hash) |
06a51d93 SR |
1211 | { |
1212 | return !hash || !hash->count; | |
1213 | } | |
1214 | ||
b448c4e3 SR |
1215 | static struct ftrace_func_entry * |
1216 | ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
1217 | { | |
1218 | unsigned long key; | |
1219 | struct ftrace_func_entry *entry; | |
1220 | struct hlist_head *hhd; | |
b448c4e3 | 1221 | |
06a51d93 | 1222 | if (ftrace_hash_empty(hash)) |
b448c4e3 SR |
1223 | return NULL; |
1224 | ||
1225 | if (hash->size_bits > 0) | |
1226 | key = hash_long(ip, hash->size_bits); | |
1227 | else | |
1228 | key = 0; | |
1229 | ||
1230 | hhd = &hash->buckets[key]; | |
1231 | ||
1bb539ca | 1232 | hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) { |
b448c4e3 SR |
1233 | if (entry->ip == ip) |
1234 | return entry; | |
1235 | } | |
1236 | return NULL; | |
1237 | } | |
1238 | ||
33dc9b12 SR |
1239 | static void __add_hash_entry(struct ftrace_hash *hash, |
1240 | struct ftrace_func_entry *entry) | |
b448c4e3 | 1241 | { |
b448c4e3 SR |
1242 | struct hlist_head *hhd; |
1243 | unsigned long key; | |
1244 | ||
b448c4e3 | 1245 | if (hash->size_bits) |
33dc9b12 | 1246 | key = hash_long(entry->ip, hash->size_bits); |
b448c4e3 SR |
1247 | else |
1248 | key = 0; | |
1249 | ||
b448c4e3 SR |
1250 | hhd = &hash->buckets[key]; |
1251 | hlist_add_head(&entry->hlist, hhd); | |
1252 | hash->count++; | |
33dc9b12 SR |
1253 | } |
1254 | ||
1255 | static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip) | |
1256 | { | |
1257 | struct ftrace_func_entry *entry; | |
1258 | ||
1259 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1260 | if (!entry) | |
1261 | return -ENOMEM; | |
1262 | ||
1263 | entry->ip = ip; | |
1264 | __add_hash_entry(hash, entry); | |
b448c4e3 SR |
1265 | |
1266 | return 0; | |
1267 | } | |
1268 | ||
1269 | static void | |
33dc9b12 | 1270 | free_hash_entry(struct ftrace_hash *hash, |
b448c4e3 SR |
1271 | struct ftrace_func_entry *entry) |
1272 | { | |
1273 | hlist_del(&entry->hlist); | |
1274 | kfree(entry); | |
1275 | hash->count--; | |
1276 | } | |
1277 | ||
33dc9b12 SR |
1278 | static void |
1279 | remove_hash_entry(struct ftrace_hash *hash, | |
1280 | struct ftrace_func_entry *entry) | |
1281 | { | |
1282 | hlist_del(&entry->hlist); | |
1283 | hash->count--; | |
1284 | } | |
1285 | ||
b448c4e3 SR |
1286 | static void ftrace_hash_clear(struct ftrace_hash *hash) |
1287 | { | |
1288 | struct hlist_head *hhd; | |
b67bfe0d | 1289 | struct hlist_node *tn; |
b448c4e3 SR |
1290 | struct ftrace_func_entry *entry; |
1291 | int size = 1 << hash->size_bits; | |
1292 | int i; | |
1293 | ||
33dc9b12 SR |
1294 | if (!hash->count) |
1295 | return; | |
1296 | ||
b448c4e3 SR |
1297 | for (i = 0; i < size; i++) { |
1298 | hhd = &hash->buckets[i]; | |
b67bfe0d | 1299 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) |
33dc9b12 | 1300 | free_hash_entry(hash, entry); |
b448c4e3 SR |
1301 | } |
1302 | FTRACE_WARN_ON(hash->count); | |
1303 | } | |
1304 | ||
33dc9b12 SR |
1305 | static void free_ftrace_hash(struct ftrace_hash *hash) |
1306 | { | |
1307 | if (!hash || hash == EMPTY_HASH) | |
1308 | return; | |
1309 | ftrace_hash_clear(hash); | |
1310 | kfree(hash->buckets); | |
1311 | kfree(hash); | |
1312 | } | |
1313 | ||
07fd5515 SR |
1314 | static void __free_ftrace_hash_rcu(struct rcu_head *rcu) |
1315 | { | |
1316 | struct ftrace_hash *hash; | |
1317 | ||
1318 | hash = container_of(rcu, struct ftrace_hash, rcu); | |
1319 | free_ftrace_hash(hash); | |
1320 | } | |
1321 | ||
1322 | static void free_ftrace_hash_rcu(struct ftrace_hash *hash) | |
1323 | { | |
1324 | if (!hash || hash == EMPTY_HASH) | |
1325 | return; | |
1326 | call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu); | |
1327 | } | |
1328 | ||
5500fa51 JO |
1329 | void ftrace_free_filter(struct ftrace_ops *ops) |
1330 | { | |
f04f24fb | 1331 | ftrace_ops_init(ops); |
33b7f99c SRRH |
1332 | free_ftrace_hash(ops->func_hash->filter_hash); |
1333 | free_ftrace_hash(ops->func_hash->notrace_hash); | |
5500fa51 JO |
1334 | } |
1335 | ||
33dc9b12 SR |
1336 | static struct ftrace_hash *alloc_ftrace_hash(int size_bits) |
1337 | { | |
1338 | struct ftrace_hash *hash; | |
1339 | int size; | |
1340 | ||
1341 | hash = kzalloc(sizeof(*hash), GFP_KERNEL); | |
1342 | if (!hash) | |
1343 | return NULL; | |
1344 | ||
1345 | size = 1 << size_bits; | |
47b0edcb | 1346 | hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL); |
33dc9b12 SR |
1347 | |
1348 | if (!hash->buckets) { | |
1349 | kfree(hash); | |
1350 | return NULL; | |
1351 | } | |
1352 | ||
1353 | hash->size_bits = size_bits; | |
1354 | ||
1355 | return hash; | |
1356 | } | |
1357 | ||
1358 | static struct ftrace_hash * | |
1359 | alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) | |
1360 | { | |
1361 | struct ftrace_func_entry *entry; | |
1362 | struct ftrace_hash *new_hash; | |
33dc9b12 SR |
1363 | int size; |
1364 | int ret; | |
1365 | int i; | |
1366 | ||
1367 | new_hash = alloc_ftrace_hash(size_bits); | |
1368 | if (!new_hash) | |
1369 | return NULL; | |
1370 | ||
1371 | /* Empty hash? */ | |
06a51d93 | 1372 | if (ftrace_hash_empty(hash)) |
33dc9b12 SR |
1373 | return new_hash; |
1374 | ||
1375 | size = 1 << hash->size_bits; | |
1376 | for (i = 0; i < size; i++) { | |
b67bfe0d | 1377 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { |
33dc9b12 SR |
1378 | ret = add_hash_entry(new_hash, entry->ip); |
1379 | if (ret < 0) | |
1380 | goto free_hash; | |
1381 | } | |
1382 | } | |
1383 | ||
1384 | FTRACE_WARN_ON(new_hash->count != hash->count); | |
1385 | ||
1386 | return new_hash; | |
1387 | ||
1388 | free_hash: | |
1389 | free_ftrace_hash(new_hash); | |
1390 | return NULL; | |
1391 | } | |
1392 | ||
41fb61c2 | 1393 | static void |
84261912 | 1394 | ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash); |
41fb61c2 | 1395 | static void |
84261912 | 1396 | ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash); |
41fb61c2 | 1397 | |
f8b8be8a MH |
1398 | static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, |
1399 | struct ftrace_hash *new_hash); | |
1400 | ||
33dc9b12 | 1401 | static int |
41fb61c2 SR |
1402 | ftrace_hash_move(struct ftrace_ops *ops, int enable, |
1403 | struct ftrace_hash **dst, struct ftrace_hash *src) | |
33dc9b12 SR |
1404 | { |
1405 | struct ftrace_func_entry *entry; | |
b67bfe0d | 1406 | struct hlist_node *tn; |
33dc9b12 | 1407 | struct hlist_head *hhd; |
07fd5515 | 1408 | struct ftrace_hash *new_hash; |
33dc9b12 SR |
1409 | int size = src->count; |
1410 | int bits = 0; | |
f8b8be8a | 1411 | int ret; |
33dc9b12 SR |
1412 | int i; |
1413 | ||
f8b8be8a MH |
1414 | /* Reject setting notrace hash on IPMODIFY ftrace_ops */ |
1415 | if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable) | |
1416 | return -EINVAL; | |
1417 | ||
33dc9b12 SR |
1418 | /* |
1419 | * If the new source is empty, just free dst and assign it | |
1420 | * the empty_hash. | |
1421 | */ | |
1422 | if (!src->count) { | |
5c27c775 MH |
1423 | new_hash = EMPTY_HASH; |
1424 | goto update; | |
33dc9b12 SR |
1425 | } |
1426 | ||
33dc9b12 SR |
1427 | /* |
1428 | * Make the hash size about 1/2 the # found | |
1429 | */ | |
1430 | for (size /= 2; size; size >>= 1) | |
1431 | bits++; | |
1432 | ||
1433 | /* Don't allocate too much */ | |
1434 | if (bits > FTRACE_HASH_MAX_BITS) | |
1435 | bits = FTRACE_HASH_MAX_BITS; | |
1436 | ||
07fd5515 SR |
1437 | new_hash = alloc_ftrace_hash(bits); |
1438 | if (!new_hash) | |
5c27c775 | 1439 | return -ENOMEM; |
33dc9b12 SR |
1440 | |
1441 | size = 1 << src->size_bits; | |
1442 | for (i = 0; i < size; i++) { | |
1443 | hhd = &src->buckets[i]; | |
b67bfe0d | 1444 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) { |
33dc9b12 | 1445 | remove_hash_entry(src, entry); |
07fd5515 | 1446 | __add_hash_entry(new_hash, entry); |
33dc9b12 SR |
1447 | } |
1448 | } | |
1449 | ||
5c27c775 | 1450 | update: |
f8b8be8a MH |
1451 | /* Make sure this can be applied if it is IPMODIFY ftrace_ops */ |
1452 | if (enable) { | |
1453 | /* IPMODIFY should be updated only when filter_hash updating */ | |
1454 | ret = ftrace_hash_ipmodify_update(ops, new_hash); | |
1455 | if (ret < 0) { | |
1456 | free_ftrace_hash(new_hash); | |
1457 | return ret; | |
1458 | } | |
1459 | } | |
1460 | ||
5c27c775 MH |
1461 | /* |
1462 | * Remove the current set, update the hash and add | |
1463 | * them back. | |
1464 | */ | |
84261912 | 1465 | ftrace_hash_rec_disable_modify(ops, enable); |
5c27c775 | 1466 | |
07fd5515 | 1467 | rcu_assign_pointer(*dst, new_hash); |
07fd5515 | 1468 | |
84261912 | 1469 | ftrace_hash_rec_enable_modify(ops, enable); |
41fb61c2 | 1470 | |
5c27c775 | 1471 | return 0; |
33dc9b12 SR |
1472 | } |
1473 | ||
fef5aeee SRRH |
1474 | static bool hash_contains_ip(unsigned long ip, |
1475 | struct ftrace_ops_hash *hash) | |
1476 | { | |
1477 | /* | |
1478 | * The function record is a match if it exists in the filter | |
1479 | * hash and not in the notrace hash. Note, an emty hash is | |
1480 | * considered a match for the filter hash, but an empty | |
1481 | * notrace hash is considered not in the notrace hash. | |
1482 | */ | |
1483 | return (ftrace_hash_empty(hash->filter_hash) || | |
1484 | ftrace_lookup_ip(hash->filter_hash, ip)) && | |
1485 | (ftrace_hash_empty(hash->notrace_hash) || | |
1486 | !ftrace_lookup_ip(hash->notrace_hash, ip)); | |
1487 | } | |
1488 | ||
b848914c SR |
1489 | /* |
1490 | * Test the hashes for this ops to see if we want to call | |
1491 | * the ops->func or not. | |
1492 | * | |
1493 | * It's a match if the ip is in the ops->filter_hash or | |
1494 | * the filter_hash does not exist or is empty, | |
1495 | * AND | |
1496 | * the ip is not in the ops->notrace_hash. | |
cdbe61bf SR |
1497 | * |
1498 | * This needs to be called with preemption disabled as | |
1499 | * the hashes are freed with call_rcu_sched(). | |
b848914c SR |
1500 | */ |
1501 | static int | |
195a8afc | 1502 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
b848914c | 1503 | { |
fef5aeee | 1504 | struct ftrace_ops_hash hash; |
b848914c SR |
1505 | int ret; |
1506 | ||
195a8afc SRRH |
1507 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
1508 | /* | |
1509 | * There's a small race when adding ops that the ftrace handler | |
1510 | * that wants regs, may be called without them. We can not | |
1511 | * allow that handler to be called if regs is NULL. | |
1512 | */ | |
1513 | if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS)) | |
1514 | return 0; | |
1515 | #endif | |
1516 | ||
fef5aeee SRRH |
1517 | hash.filter_hash = rcu_dereference_raw_notrace(ops->func_hash->filter_hash); |
1518 | hash.notrace_hash = rcu_dereference_raw_notrace(ops->func_hash->notrace_hash); | |
b848914c | 1519 | |
fef5aeee | 1520 | if (hash_contains_ip(ip, &hash)) |
b848914c SR |
1521 | ret = 1; |
1522 | else | |
1523 | ret = 0; | |
b848914c SR |
1524 | |
1525 | return ret; | |
1526 | } | |
1527 | ||
493762fc SR |
1528 | /* |
1529 | * This is a double for. Do not use 'break' to break out of the loop, | |
1530 | * you must use a goto. | |
1531 | */ | |
1532 | #define do_for_each_ftrace_rec(pg, rec) \ | |
1533 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
1534 | int _____i; \ | |
1535 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
1536 | rec = &pg->records[_____i]; | |
1537 | ||
1538 | #define while_for_each_ftrace_rec() \ | |
1539 | } \ | |
1540 | } | |
1541 | ||
5855fead SR |
1542 | |
1543 | static int ftrace_cmp_recs(const void *a, const void *b) | |
1544 | { | |
a650e02a SR |
1545 | const struct dyn_ftrace *key = a; |
1546 | const struct dyn_ftrace *rec = b; | |
5855fead | 1547 | |
a650e02a | 1548 | if (key->flags < rec->ip) |
5855fead | 1549 | return -1; |
a650e02a SR |
1550 | if (key->ip >= rec->ip + MCOUNT_INSN_SIZE) |
1551 | return 1; | |
5855fead SR |
1552 | return 0; |
1553 | } | |
1554 | ||
f0cf973a | 1555 | static unsigned long ftrace_location_range(unsigned long start, unsigned long end) |
c88fd863 SR |
1556 | { |
1557 | struct ftrace_page *pg; | |
1558 | struct dyn_ftrace *rec; | |
5855fead | 1559 | struct dyn_ftrace key; |
c88fd863 | 1560 | |
a650e02a SR |
1561 | key.ip = start; |
1562 | key.flags = end; /* overload flags, as it is unsigned long */ | |
5855fead SR |
1563 | |
1564 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
a650e02a SR |
1565 | if (end < pg->records[0].ip || |
1566 | start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) | |
9644302e | 1567 | continue; |
5855fead SR |
1568 | rec = bsearch(&key, pg->records, pg->index, |
1569 | sizeof(struct dyn_ftrace), | |
1570 | ftrace_cmp_recs); | |
1571 | if (rec) | |
f0cf973a | 1572 | return rec->ip; |
5855fead | 1573 | } |
c88fd863 SR |
1574 | |
1575 | return 0; | |
1576 | } | |
1577 | ||
a650e02a SR |
1578 | /** |
1579 | * ftrace_location - return true if the ip giving is a traced location | |
1580 | * @ip: the instruction pointer to check | |
1581 | * | |
f0cf973a | 1582 | * Returns rec->ip if @ip given is a pointer to a ftrace location. |
a650e02a SR |
1583 | * That is, the instruction that is either a NOP or call to |
1584 | * the function tracer. It checks the ftrace internal tables to | |
1585 | * determine if the address belongs or not. | |
1586 | */ | |
f0cf973a | 1587 | unsigned long ftrace_location(unsigned long ip) |
a650e02a SR |
1588 | { |
1589 | return ftrace_location_range(ip, ip); | |
1590 | } | |
1591 | ||
1592 | /** | |
1593 | * ftrace_text_reserved - return true if range contains an ftrace location | |
1594 | * @start: start of range to search | |
1595 | * @end: end of range to search (inclusive). @end points to the last byte to check. | |
1596 | * | |
1597 | * Returns 1 if @start and @end contains a ftrace location. | |
1598 | * That is, the instruction that is either a NOP or call to | |
1599 | * the function tracer. It checks the ftrace internal tables to | |
1600 | * determine if the address belongs or not. | |
1601 | */ | |
d88471cb | 1602 | int ftrace_text_reserved(const void *start, const void *end) |
a650e02a | 1603 | { |
f0cf973a SR |
1604 | unsigned long ret; |
1605 | ||
1606 | ret = ftrace_location_range((unsigned long)start, | |
1607 | (unsigned long)end); | |
1608 | ||
1609 | return (int)!!ret; | |
a650e02a SR |
1610 | } |
1611 | ||
4fbb48cb SRRH |
1612 | /* Test if ops registered to this rec needs regs */ |
1613 | static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec) | |
1614 | { | |
1615 | struct ftrace_ops *ops; | |
1616 | bool keep_regs = false; | |
1617 | ||
1618 | for (ops = ftrace_ops_list; | |
1619 | ops != &ftrace_list_end; ops = ops->next) { | |
1620 | /* pass rec in as regs to have non-NULL val */ | |
1621 | if (ftrace_ops_test(ops, rec->ip, rec)) { | |
1622 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1623 | keep_regs = true; | |
1624 | break; | |
1625 | } | |
1626 | } | |
1627 | } | |
1628 | ||
1629 | return keep_regs; | |
1630 | } | |
1631 | ||
ed926f9b SR |
1632 | static void __ftrace_hash_rec_update(struct ftrace_ops *ops, |
1633 | int filter_hash, | |
1634 | bool inc) | |
1635 | { | |
1636 | struct ftrace_hash *hash; | |
1637 | struct ftrace_hash *other_hash; | |
1638 | struct ftrace_page *pg; | |
1639 | struct dyn_ftrace *rec; | |
1640 | int count = 0; | |
1641 | int all = 0; | |
1642 | ||
1643 | /* Only update if the ops has been registered */ | |
1644 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
1645 | return; | |
1646 | ||
1647 | /* | |
1648 | * In the filter_hash case: | |
1649 | * If the count is zero, we update all records. | |
1650 | * Otherwise we just update the items in the hash. | |
1651 | * | |
1652 | * In the notrace_hash case: | |
1653 | * We enable the update in the hash. | |
1654 | * As disabling notrace means enabling the tracing, | |
1655 | * and enabling notrace means disabling, the inc variable | |
1656 | * gets inversed. | |
1657 | */ | |
1658 | if (filter_hash) { | |
33b7f99c SRRH |
1659 | hash = ops->func_hash->filter_hash; |
1660 | other_hash = ops->func_hash->notrace_hash; | |
06a51d93 | 1661 | if (ftrace_hash_empty(hash)) |
ed926f9b SR |
1662 | all = 1; |
1663 | } else { | |
1664 | inc = !inc; | |
33b7f99c SRRH |
1665 | hash = ops->func_hash->notrace_hash; |
1666 | other_hash = ops->func_hash->filter_hash; | |
ed926f9b SR |
1667 | /* |
1668 | * If the notrace hash has no items, | |
1669 | * then there's nothing to do. | |
1670 | */ | |
06a51d93 | 1671 | if (ftrace_hash_empty(hash)) |
ed926f9b SR |
1672 | return; |
1673 | } | |
1674 | ||
1675 | do_for_each_ftrace_rec(pg, rec) { | |
1676 | int in_other_hash = 0; | |
1677 | int in_hash = 0; | |
1678 | int match = 0; | |
1679 | ||
1680 | if (all) { | |
1681 | /* | |
1682 | * Only the filter_hash affects all records. | |
1683 | * Update if the record is not in the notrace hash. | |
1684 | */ | |
b848914c | 1685 | if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) |
ed926f9b SR |
1686 | match = 1; |
1687 | } else { | |
06a51d93 SR |
1688 | in_hash = !!ftrace_lookup_ip(hash, rec->ip); |
1689 | in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip); | |
ed926f9b SR |
1690 | |
1691 | /* | |
19eab4a4 SRRH |
1692 | * If filter_hash is set, we want to match all functions |
1693 | * that are in the hash but not in the other hash. | |
ed926f9b | 1694 | * |
19eab4a4 SRRH |
1695 | * If filter_hash is not set, then we are decrementing. |
1696 | * That means we match anything that is in the hash | |
1697 | * and also in the other_hash. That is, we need to turn | |
1698 | * off functions in the other hash because they are disabled | |
1699 | * by this hash. | |
ed926f9b SR |
1700 | */ |
1701 | if (filter_hash && in_hash && !in_other_hash) | |
1702 | match = 1; | |
1703 | else if (!filter_hash && in_hash && | |
06a51d93 | 1704 | (in_other_hash || ftrace_hash_empty(other_hash))) |
ed926f9b SR |
1705 | match = 1; |
1706 | } | |
1707 | if (!match) | |
1708 | continue; | |
1709 | ||
1710 | if (inc) { | |
1711 | rec->flags++; | |
0376bde1 | 1712 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX)) |
ed926f9b | 1713 | return; |
79922b80 SRRH |
1714 | |
1715 | /* | |
1716 | * If there's only a single callback registered to a | |
1717 | * function, and the ops has a trampoline registered | |
1718 | * for it, then we can call it directly. | |
1719 | */ | |
fef5aeee | 1720 | if (ftrace_rec_count(rec) == 1 && ops->trampoline) |
79922b80 | 1721 | rec->flags |= FTRACE_FL_TRAMP; |
fef5aeee | 1722 | else |
79922b80 SRRH |
1723 | /* |
1724 | * If we are adding another function callback | |
1725 | * to this function, and the previous had a | |
bce0b6c5 SRRH |
1726 | * custom trampoline in use, then we need to go |
1727 | * back to the default trampoline. | |
79922b80 | 1728 | */ |
fef5aeee | 1729 | rec->flags &= ~FTRACE_FL_TRAMP; |
79922b80 | 1730 | |
08f6fba5 SR |
1731 | /* |
1732 | * If any ops wants regs saved for this function | |
1733 | * then all ops will get saved regs. | |
1734 | */ | |
1735 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) | |
1736 | rec->flags |= FTRACE_FL_REGS; | |
ed926f9b | 1737 | } else { |
0376bde1 | 1738 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0)) |
ed926f9b SR |
1739 | return; |
1740 | rec->flags--; | |
79922b80 | 1741 | |
4fbb48cb SRRH |
1742 | /* |
1743 | * If the rec had REGS enabled and the ops that is | |
1744 | * being removed had REGS set, then see if there is | |
1745 | * still any ops for this record that wants regs. | |
1746 | * If not, we can stop recording them. | |
1747 | */ | |
0376bde1 | 1748 | if (ftrace_rec_count(rec) > 0 && |
4fbb48cb SRRH |
1749 | rec->flags & FTRACE_FL_REGS && |
1750 | ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1751 | if (!test_rec_ops_needs_regs(rec)) | |
1752 | rec->flags &= ~FTRACE_FL_REGS; | |
1753 | } | |
79922b80 | 1754 | |
fef5aeee SRRH |
1755 | /* |
1756 | * If the rec had TRAMP enabled, then it needs to | |
1757 | * be cleared. As TRAMP can only be enabled iff | |
1758 | * there is only a single ops attached to it. | |
1759 | * In otherwords, always disable it on decrementing. | |
1760 | * In the future, we may set it if rec count is | |
1761 | * decremented to one, and the ops that is left | |
1762 | * has a trampoline. | |
1763 | */ | |
1764 | rec->flags &= ~FTRACE_FL_TRAMP; | |
1765 | ||
79922b80 SRRH |
1766 | /* |
1767 | * flags will be cleared in ftrace_check_record() | |
1768 | * if rec count is zero. | |
1769 | */ | |
ed926f9b SR |
1770 | } |
1771 | count++; | |
1772 | /* Shortcut, if we handled all records, we are done. */ | |
1773 | if (!all && count == hash->count) | |
1774 | return; | |
1775 | } while_for_each_ftrace_rec(); | |
1776 | } | |
1777 | ||
1778 | static void ftrace_hash_rec_disable(struct ftrace_ops *ops, | |
1779 | int filter_hash) | |
1780 | { | |
1781 | __ftrace_hash_rec_update(ops, filter_hash, 0); | |
1782 | } | |
1783 | ||
1784 | static void ftrace_hash_rec_enable(struct ftrace_ops *ops, | |
1785 | int filter_hash) | |
1786 | { | |
1787 | __ftrace_hash_rec_update(ops, filter_hash, 1); | |
1788 | } | |
1789 | ||
84261912 SRRH |
1790 | static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops, |
1791 | int filter_hash, int inc) | |
1792 | { | |
1793 | struct ftrace_ops *op; | |
1794 | ||
1795 | __ftrace_hash_rec_update(ops, filter_hash, inc); | |
1796 | ||
1797 | if (ops->func_hash != &global_ops.local_hash) | |
1798 | return; | |
1799 | ||
1800 | /* | |
1801 | * If the ops shares the global_ops hash, then we need to update | |
1802 | * all ops that are enabled and use this hash. | |
1803 | */ | |
1804 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1805 | /* Already done */ | |
1806 | if (op == ops) | |
1807 | continue; | |
1808 | if (op->func_hash == &global_ops.local_hash) | |
1809 | __ftrace_hash_rec_update(op, filter_hash, inc); | |
1810 | } while_for_each_ftrace_op(op); | |
1811 | } | |
1812 | ||
1813 | static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, | |
1814 | int filter_hash) | |
1815 | { | |
1816 | ftrace_hash_rec_update_modify(ops, filter_hash, 0); | |
1817 | } | |
1818 | ||
1819 | static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, | |
1820 | int filter_hash) | |
1821 | { | |
1822 | ftrace_hash_rec_update_modify(ops, filter_hash, 1); | |
1823 | } | |
1824 | ||
f8b8be8a MH |
1825 | /* |
1826 | * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK | |
1827 | * or no-needed to update, -EBUSY if it detects a conflict of the flag | |
1828 | * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs. | |
1829 | * Note that old_hash and new_hash has below meanings | |
1830 | * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected) | |
1831 | * - If the hash is EMPTY_HASH, it hits nothing | |
1832 | * - Anything else hits the recs which match the hash entries. | |
1833 | */ | |
1834 | static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops, | |
1835 | struct ftrace_hash *old_hash, | |
1836 | struct ftrace_hash *new_hash) | |
1837 | { | |
1838 | struct ftrace_page *pg; | |
1839 | struct dyn_ftrace *rec, *end = NULL; | |
1840 | int in_old, in_new; | |
1841 | ||
1842 | /* Only update if the ops has been registered */ | |
1843 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
1844 | return 0; | |
1845 | ||
1846 | if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY)) | |
1847 | return 0; | |
1848 | ||
1849 | /* | |
1850 | * Since the IPMODIFY is a very address sensitive action, we do not | |
1851 | * allow ftrace_ops to set all functions to new hash. | |
1852 | */ | |
1853 | if (!new_hash || !old_hash) | |
1854 | return -EINVAL; | |
1855 | ||
1856 | /* Update rec->flags */ | |
1857 | do_for_each_ftrace_rec(pg, rec) { | |
1858 | /* We need to update only differences of filter_hash */ | |
1859 | in_old = !!ftrace_lookup_ip(old_hash, rec->ip); | |
1860 | in_new = !!ftrace_lookup_ip(new_hash, rec->ip); | |
1861 | if (in_old == in_new) | |
1862 | continue; | |
1863 | ||
1864 | if (in_new) { | |
1865 | /* New entries must ensure no others are using it */ | |
1866 | if (rec->flags & FTRACE_FL_IPMODIFY) | |
1867 | goto rollback; | |
1868 | rec->flags |= FTRACE_FL_IPMODIFY; | |
1869 | } else /* Removed entry */ | |
1870 | rec->flags &= ~FTRACE_FL_IPMODIFY; | |
1871 | } while_for_each_ftrace_rec(); | |
1872 | ||
1873 | return 0; | |
1874 | ||
1875 | rollback: | |
1876 | end = rec; | |
1877 | ||
1878 | /* Roll back what we did above */ | |
1879 | do_for_each_ftrace_rec(pg, rec) { | |
1880 | if (rec == end) | |
1881 | goto err_out; | |
1882 | ||
1883 | in_old = !!ftrace_lookup_ip(old_hash, rec->ip); | |
1884 | in_new = !!ftrace_lookup_ip(new_hash, rec->ip); | |
1885 | if (in_old == in_new) | |
1886 | continue; | |
1887 | ||
1888 | if (in_new) | |
1889 | rec->flags &= ~FTRACE_FL_IPMODIFY; | |
1890 | else | |
1891 | rec->flags |= FTRACE_FL_IPMODIFY; | |
1892 | } while_for_each_ftrace_rec(); | |
1893 | ||
1894 | err_out: | |
1895 | return -EBUSY; | |
1896 | } | |
1897 | ||
1898 | static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops) | |
1899 | { | |
1900 | struct ftrace_hash *hash = ops->func_hash->filter_hash; | |
1901 | ||
1902 | if (ftrace_hash_empty(hash)) | |
1903 | hash = NULL; | |
1904 | ||
1905 | return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash); | |
1906 | } | |
1907 | ||
1908 | /* Disabling always succeeds */ | |
1909 | static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops) | |
1910 | { | |
1911 | struct ftrace_hash *hash = ops->func_hash->filter_hash; | |
1912 | ||
1913 | if (ftrace_hash_empty(hash)) | |
1914 | hash = NULL; | |
1915 | ||
1916 | __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH); | |
1917 | } | |
1918 | ||
1919 | static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, | |
1920 | struct ftrace_hash *new_hash) | |
1921 | { | |
1922 | struct ftrace_hash *old_hash = ops->func_hash->filter_hash; | |
1923 | ||
1924 | if (ftrace_hash_empty(old_hash)) | |
1925 | old_hash = NULL; | |
1926 | ||
1927 | if (ftrace_hash_empty(new_hash)) | |
1928 | new_hash = NULL; | |
1929 | ||
1930 | return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash); | |
1931 | } | |
1932 | ||
b17e8a37 SR |
1933 | static void print_ip_ins(const char *fmt, unsigned char *p) |
1934 | { | |
1935 | int i; | |
1936 | ||
1937 | printk(KERN_CONT "%s", fmt); | |
1938 | ||
1939 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
1940 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
1941 | } | |
1942 | ||
4fd3279b SRRH |
1943 | static struct ftrace_ops * |
1944 | ftrace_find_tramp_ops_any(struct dyn_ftrace *rec); | |
1945 | ||
c88fd863 SR |
1946 | /** |
1947 | * ftrace_bug - report and shutdown function tracer | |
1948 | * @failed: The failed type (EFAULT, EINVAL, EPERM) | |
4fd3279b | 1949 | * @rec: The record that failed |
c88fd863 SR |
1950 | * |
1951 | * The arch code that enables or disables the function tracing | |
1952 | * can call ftrace_bug() when it has detected a problem in | |
1953 | * modifying the code. @failed should be one of either: | |
1954 | * EFAULT - if the problem happens on reading the @ip address | |
1955 | * EINVAL - if what is read at @ip is not what was expected | |
1956 | * EPERM - if the problem happens on writting to the @ip address | |
1957 | */ | |
4fd3279b | 1958 | void ftrace_bug(int failed, struct dyn_ftrace *rec) |
b17e8a37 | 1959 | { |
4fd3279b SRRH |
1960 | unsigned long ip = rec ? rec->ip : 0; |
1961 | ||
b17e8a37 SR |
1962 | switch (failed) { |
1963 | case -EFAULT: | |
1964 | FTRACE_WARN_ON_ONCE(1); | |
1965 | pr_info("ftrace faulted on modifying "); | |
1966 | print_ip_sym(ip); | |
1967 | break; | |
1968 | case -EINVAL: | |
1969 | FTRACE_WARN_ON_ONCE(1); | |
1970 | pr_info("ftrace failed to modify "); | |
1971 | print_ip_sym(ip); | |
b17e8a37 | 1972 | print_ip_ins(" actual: ", (unsigned char *)ip); |
4fd3279b | 1973 | pr_cont("\n"); |
b17e8a37 SR |
1974 | break; |
1975 | case -EPERM: | |
1976 | FTRACE_WARN_ON_ONCE(1); | |
1977 | pr_info("ftrace faulted on writing "); | |
1978 | print_ip_sym(ip); | |
1979 | break; | |
1980 | default: | |
1981 | FTRACE_WARN_ON_ONCE(1); | |
1982 | pr_info("ftrace faulted on unknown error "); | |
1983 | print_ip_sym(ip); | |
1984 | } | |
4fd3279b SRRH |
1985 | if (rec) { |
1986 | struct ftrace_ops *ops = NULL; | |
1987 | ||
1988 | pr_info("ftrace record flags: %lx\n", rec->flags); | |
1989 | pr_cont(" (%ld)%s", ftrace_rec_count(rec), | |
1990 | rec->flags & FTRACE_FL_REGS ? " R" : " "); | |
1991 | if (rec->flags & FTRACE_FL_TRAMP_EN) { | |
1992 | ops = ftrace_find_tramp_ops_any(rec); | |
1993 | if (ops) | |
1994 | pr_cont("\ttramp: %pS", | |
1995 | (void *)ops->trampoline); | |
1996 | else | |
1997 | pr_cont("\ttramp: ERROR!"); | |
1998 | ||
1999 | } | |
2000 | ip = ftrace_get_addr_curr(rec); | |
2001 | pr_cont(" expected tramp: %lx\n", ip); | |
2002 | } | |
b17e8a37 SR |
2003 | } |
2004 | ||
c88fd863 | 2005 | static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update) |
5072c59f | 2006 | { |
64fbcd16 | 2007 | unsigned long flag = 0UL; |
e7d3737e | 2008 | |
982c350b | 2009 | /* |
30fb6aa7 | 2010 | * If we are updating calls: |
982c350b | 2011 | * |
ed926f9b SR |
2012 | * If the record has a ref count, then we need to enable it |
2013 | * because someone is using it. | |
982c350b | 2014 | * |
ed926f9b SR |
2015 | * Otherwise we make sure its disabled. |
2016 | * | |
30fb6aa7 | 2017 | * If we are disabling calls, then disable all records that |
ed926f9b | 2018 | * are enabled. |
982c350b | 2019 | */ |
0376bde1 | 2020 | if (enable && ftrace_rec_count(rec)) |
ed926f9b | 2021 | flag = FTRACE_FL_ENABLED; |
982c350b | 2022 | |
08f6fba5 | 2023 | /* |
79922b80 SRRH |
2024 | * If enabling and the REGS flag does not match the REGS_EN, or |
2025 | * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore | |
2026 | * this record. Set flags to fail the compare against ENABLED. | |
08f6fba5 | 2027 | */ |
79922b80 SRRH |
2028 | if (flag) { |
2029 | if (!(rec->flags & FTRACE_FL_REGS) != | |
2030 | !(rec->flags & FTRACE_FL_REGS_EN)) | |
2031 | flag |= FTRACE_FL_REGS; | |
2032 | ||
2033 | if (!(rec->flags & FTRACE_FL_TRAMP) != | |
2034 | !(rec->flags & FTRACE_FL_TRAMP_EN)) | |
2035 | flag |= FTRACE_FL_TRAMP; | |
2036 | } | |
08f6fba5 | 2037 | |
64fbcd16 XG |
2038 | /* If the state of this record hasn't changed, then do nothing */ |
2039 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
c88fd863 | 2040 | return FTRACE_UPDATE_IGNORE; |
982c350b | 2041 | |
64fbcd16 | 2042 | if (flag) { |
08f6fba5 SR |
2043 | /* Save off if rec is being enabled (for return value) */ |
2044 | flag ^= rec->flags & FTRACE_FL_ENABLED; | |
2045 | ||
2046 | if (update) { | |
c88fd863 | 2047 | rec->flags |= FTRACE_FL_ENABLED; |
08f6fba5 SR |
2048 | if (flag & FTRACE_FL_REGS) { |
2049 | if (rec->flags & FTRACE_FL_REGS) | |
2050 | rec->flags |= FTRACE_FL_REGS_EN; | |
2051 | else | |
2052 | rec->flags &= ~FTRACE_FL_REGS_EN; | |
2053 | } | |
79922b80 SRRH |
2054 | if (flag & FTRACE_FL_TRAMP) { |
2055 | if (rec->flags & FTRACE_FL_TRAMP) | |
2056 | rec->flags |= FTRACE_FL_TRAMP_EN; | |
2057 | else | |
2058 | rec->flags &= ~FTRACE_FL_TRAMP_EN; | |
2059 | } | |
08f6fba5 SR |
2060 | } |
2061 | ||
2062 | /* | |
2063 | * If this record is being updated from a nop, then | |
2064 | * return UPDATE_MAKE_CALL. | |
08f6fba5 SR |
2065 | * Otherwise, |
2066 | * return UPDATE_MODIFY_CALL to tell the caller to convert | |
f1b2f2bd | 2067 | * from the save regs, to a non-save regs function or |
79922b80 | 2068 | * vice versa, or from a trampoline call. |
08f6fba5 SR |
2069 | */ |
2070 | if (flag & FTRACE_FL_ENABLED) | |
2071 | return FTRACE_UPDATE_MAKE_CALL; | |
f1b2f2bd SRRH |
2072 | |
2073 | return FTRACE_UPDATE_MODIFY_CALL; | |
c88fd863 SR |
2074 | } |
2075 | ||
08f6fba5 SR |
2076 | if (update) { |
2077 | /* If there's no more users, clear all flags */ | |
0376bde1 | 2078 | if (!ftrace_rec_count(rec)) |
08f6fba5 SR |
2079 | rec->flags = 0; |
2080 | else | |
b24d443b SRRH |
2081 | /* |
2082 | * Just disable the record, but keep the ops TRAMP | |
2083 | * and REGS states. The _EN flags must be disabled though. | |
2084 | */ | |
2085 | rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN | | |
2086 | FTRACE_FL_REGS_EN); | |
08f6fba5 | 2087 | } |
c88fd863 SR |
2088 | |
2089 | return FTRACE_UPDATE_MAKE_NOP; | |
2090 | } | |
2091 | ||
2092 | /** | |
2093 | * ftrace_update_record, set a record that now is tracing or not | |
2094 | * @rec: the record to update | |
2095 | * @enable: set to 1 if the record is tracing, zero to force disable | |
2096 | * | |
2097 | * The records that represent all functions that can be traced need | |
2098 | * to be updated when tracing has been enabled. | |
2099 | */ | |
2100 | int ftrace_update_record(struct dyn_ftrace *rec, int enable) | |
2101 | { | |
2102 | return ftrace_check_record(rec, enable, 1); | |
2103 | } | |
2104 | ||
2105 | /** | |
2106 | * ftrace_test_record, check if the record has been enabled or not | |
2107 | * @rec: the record to test | |
2108 | * @enable: set to 1 to check if enabled, 0 if it is disabled | |
2109 | * | |
2110 | * The arch code may need to test if a record is already set to | |
2111 | * tracing to determine how to modify the function code that it | |
2112 | * represents. | |
2113 | */ | |
2114 | int ftrace_test_record(struct dyn_ftrace *rec, int enable) | |
2115 | { | |
2116 | return ftrace_check_record(rec, enable, 0); | |
2117 | } | |
2118 | ||
5fecaa04 SRRH |
2119 | static struct ftrace_ops * |
2120 | ftrace_find_tramp_ops_any(struct dyn_ftrace *rec) | |
2121 | { | |
2122 | struct ftrace_ops *op; | |
fef5aeee | 2123 | unsigned long ip = rec->ip; |
5fecaa04 SRRH |
2124 | |
2125 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2126 | ||
2127 | if (!op->trampoline) | |
2128 | continue; | |
2129 | ||
fef5aeee | 2130 | if (hash_contains_ip(ip, op->func_hash)) |
5fecaa04 SRRH |
2131 | return op; |
2132 | } while_for_each_ftrace_op(op); | |
2133 | ||
2134 | return NULL; | |
2135 | } | |
2136 | ||
79922b80 SRRH |
2137 | static struct ftrace_ops * |
2138 | ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec) | |
2139 | { | |
2140 | struct ftrace_ops *op; | |
fef5aeee | 2141 | unsigned long ip = rec->ip; |
79922b80 | 2142 | |
fef5aeee SRRH |
2143 | /* |
2144 | * Need to check removed ops first. | |
2145 | * If they are being removed, and this rec has a tramp, | |
2146 | * and this rec is in the ops list, then it would be the | |
2147 | * one with the tramp. | |
2148 | */ | |
2149 | if (removed_ops) { | |
2150 | if (hash_contains_ip(ip, &removed_ops->old_hash)) | |
79922b80 SRRH |
2151 | return removed_ops; |
2152 | } | |
2153 | ||
fef5aeee SRRH |
2154 | /* |
2155 | * Need to find the current trampoline for a rec. | |
2156 | * Now, a trampoline is only attached to a rec if there | |
2157 | * was a single 'ops' attached to it. But this can be called | |
2158 | * when we are adding another op to the rec or removing the | |
2159 | * current one. Thus, if the op is being added, we can | |
2160 | * ignore it because it hasn't attached itself to the rec | |
4fc40904 SRRH |
2161 | * yet. |
2162 | * | |
2163 | * If an ops is being modified (hooking to different functions) | |
2164 | * then we don't care about the new functions that are being | |
2165 | * added, just the old ones (that are probably being removed). | |
2166 | * | |
2167 | * If we are adding an ops to a function that already is using | |
2168 | * a trampoline, it needs to be removed (trampolines are only | |
2169 | * for single ops connected), then an ops that is not being | |
2170 | * modified also needs to be checked. | |
fef5aeee | 2171 | */ |
79922b80 | 2172 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
fef5aeee SRRH |
2173 | |
2174 | if (!op->trampoline) | |
2175 | continue; | |
2176 | ||
2177 | /* | |
2178 | * If the ops is being added, it hasn't gotten to | |
2179 | * the point to be removed from this tree yet. | |
2180 | */ | |
2181 | if (op->flags & FTRACE_OPS_FL_ADDING) | |
79922b80 SRRH |
2182 | continue; |
2183 | ||
4fc40904 | 2184 | |
fef5aeee | 2185 | /* |
4fc40904 SRRH |
2186 | * If the ops is being modified and is in the old |
2187 | * hash, then it is probably being removed from this | |
2188 | * function. | |
fef5aeee | 2189 | */ |
fef5aeee SRRH |
2190 | if ((op->flags & FTRACE_OPS_FL_MODIFYING) && |
2191 | hash_contains_ip(ip, &op->old_hash)) | |
79922b80 | 2192 | return op; |
4fc40904 SRRH |
2193 | /* |
2194 | * If the ops is not being added or modified, and it's | |
2195 | * in its normal filter hash, then this must be the one | |
2196 | * we want! | |
2197 | */ | |
2198 | if (!(op->flags & FTRACE_OPS_FL_MODIFYING) && | |
2199 | hash_contains_ip(ip, op->func_hash)) | |
2200 | return op; | |
79922b80 SRRH |
2201 | |
2202 | } while_for_each_ftrace_op(op); | |
2203 | ||
2204 | return NULL; | |
2205 | } | |
2206 | ||
2207 | static struct ftrace_ops * | |
2208 | ftrace_find_tramp_ops_new(struct dyn_ftrace *rec) | |
2209 | { | |
2210 | struct ftrace_ops *op; | |
fef5aeee | 2211 | unsigned long ip = rec->ip; |
79922b80 SRRH |
2212 | |
2213 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2214 | /* pass rec in as regs to have non-NULL val */ | |
fef5aeee | 2215 | if (hash_contains_ip(ip, op->func_hash)) |
79922b80 SRRH |
2216 | return op; |
2217 | } while_for_each_ftrace_op(op); | |
2218 | ||
2219 | return NULL; | |
2220 | } | |
2221 | ||
7413af1f SRRH |
2222 | /** |
2223 | * ftrace_get_addr_new - Get the call address to set to | |
2224 | * @rec: The ftrace record descriptor | |
2225 | * | |
2226 | * If the record has the FTRACE_FL_REGS set, that means that it | |
2227 | * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS | |
2228 | * is not not set, then it wants to convert to the normal callback. | |
2229 | * | |
2230 | * Returns the address of the trampoline to set to | |
2231 | */ | |
2232 | unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec) | |
2233 | { | |
79922b80 SRRH |
2234 | struct ftrace_ops *ops; |
2235 | ||
2236 | /* Trampolines take precedence over regs */ | |
2237 | if (rec->flags & FTRACE_FL_TRAMP) { | |
2238 | ops = ftrace_find_tramp_ops_new(rec); | |
2239 | if (FTRACE_WARN_ON(!ops || !ops->trampoline)) { | |
bce0b6c5 SRRH |
2240 | pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n", |
2241 | (void *)rec->ip, (void *)rec->ip, rec->flags); | |
79922b80 SRRH |
2242 | /* Ftrace is shutting down, return anything */ |
2243 | return (unsigned long)FTRACE_ADDR; | |
2244 | } | |
2245 | return ops->trampoline; | |
2246 | } | |
2247 | ||
7413af1f SRRH |
2248 | if (rec->flags & FTRACE_FL_REGS) |
2249 | return (unsigned long)FTRACE_REGS_ADDR; | |
2250 | else | |
2251 | return (unsigned long)FTRACE_ADDR; | |
2252 | } | |
2253 | ||
2254 | /** | |
2255 | * ftrace_get_addr_curr - Get the call address that is already there | |
2256 | * @rec: The ftrace record descriptor | |
2257 | * | |
2258 | * The FTRACE_FL_REGS_EN is set when the record already points to | |
2259 | * a function that saves all the regs. Basically the '_EN' version | |
2260 | * represents the current state of the function. | |
2261 | * | |
2262 | * Returns the address of the trampoline that is currently being called | |
2263 | */ | |
2264 | unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec) | |
2265 | { | |
79922b80 SRRH |
2266 | struct ftrace_ops *ops; |
2267 | ||
2268 | /* Trampolines take precedence over regs */ | |
2269 | if (rec->flags & FTRACE_FL_TRAMP_EN) { | |
2270 | ops = ftrace_find_tramp_ops_curr(rec); | |
2271 | if (FTRACE_WARN_ON(!ops)) { | |
2272 | pr_warning("Bad trampoline accounting at: %p (%pS)\n", | |
2273 | (void *)rec->ip, (void *)rec->ip); | |
2274 | /* Ftrace is shutting down, return anything */ | |
2275 | return (unsigned long)FTRACE_ADDR; | |
2276 | } | |
2277 | return ops->trampoline; | |
2278 | } | |
2279 | ||
7413af1f SRRH |
2280 | if (rec->flags & FTRACE_FL_REGS_EN) |
2281 | return (unsigned long)FTRACE_REGS_ADDR; | |
2282 | else | |
2283 | return (unsigned long)FTRACE_ADDR; | |
2284 | } | |
2285 | ||
c88fd863 SR |
2286 | static int |
2287 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) | |
2288 | { | |
08f6fba5 | 2289 | unsigned long ftrace_old_addr; |
c88fd863 SR |
2290 | unsigned long ftrace_addr; |
2291 | int ret; | |
2292 | ||
7c0868e0 | 2293 | ftrace_addr = ftrace_get_addr_new(rec); |
c88fd863 | 2294 | |
7c0868e0 SRRH |
2295 | /* This needs to be done before we call ftrace_update_record */ |
2296 | ftrace_old_addr = ftrace_get_addr_curr(rec); | |
2297 | ||
2298 | ret = ftrace_update_record(rec, enable); | |
08f6fba5 | 2299 | |
c88fd863 SR |
2300 | switch (ret) { |
2301 | case FTRACE_UPDATE_IGNORE: | |
2302 | return 0; | |
2303 | ||
2304 | case FTRACE_UPDATE_MAKE_CALL: | |
64fbcd16 | 2305 | return ftrace_make_call(rec, ftrace_addr); |
c88fd863 SR |
2306 | |
2307 | case FTRACE_UPDATE_MAKE_NOP: | |
39b5552c | 2308 | return ftrace_make_nop(NULL, rec, ftrace_old_addr); |
08f6fba5 | 2309 | |
08f6fba5 | 2310 | case FTRACE_UPDATE_MODIFY_CALL: |
08f6fba5 | 2311 | return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr); |
5072c59f SR |
2312 | } |
2313 | ||
c88fd863 | 2314 | return -1; /* unknow ftrace bug */ |
5072c59f SR |
2315 | } |
2316 | ||
e4f5d544 | 2317 | void __weak ftrace_replace_code(int enable) |
3c1720f0 | 2318 | { |
3c1720f0 SR |
2319 | struct dyn_ftrace *rec; |
2320 | struct ftrace_page *pg; | |
6a24a244 | 2321 | int failed; |
3c1720f0 | 2322 | |
45a4a237 SR |
2323 | if (unlikely(ftrace_disabled)) |
2324 | return; | |
2325 | ||
265c831c | 2326 | do_for_each_ftrace_rec(pg, rec) { |
e4f5d544 | 2327 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 2328 | if (failed) { |
4fd3279b | 2329 | ftrace_bug(failed, rec); |
3279ba37 SR |
2330 | /* Stop processing */ |
2331 | return; | |
3c1720f0 | 2332 | } |
265c831c | 2333 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
2334 | } |
2335 | ||
c88fd863 SR |
2336 | struct ftrace_rec_iter { |
2337 | struct ftrace_page *pg; | |
2338 | int index; | |
2339 | }; | |
2340 | ||
2341 | /** | |
2342 | * ftrace_rec_iter_start, start up iterating over traced functions | |
2343 | * | |
2344 | * Returns an iterator handle that is used to iterate over all | |
2345 | * the records that represent address locations where functions | |
2346 | * are traced. | |
2347 | * | |
2348 | * May return NULL if no records are available. | |
2349 | */ | |
2350 | struct ftrace_rec_iter *ftrace_rec_iter_start(void) | |
2351 | { | |
2352 | /* | |
2353 | * We only use a single iterator. | |
2354 | * Protected by the ftrace_lock mutex. | |
2355 | */ | |
2356 | static struct ftrace_rec_iter ftrace_rec_iter; | |
2357 | struct ftrace_rec_iter *iter = &ftrace_rec_iter; | |
2358 | ||
2359 | iter->pg = ftrace_pages_start; | |
2360 | iter->index = 0; | |
2361 | ||
2362 | /* Could have empty pages */ | |
2363 | while (iter->pg && !iter->pg->index) | |
2364 | iter->pg = iter->pg->next; | |
2365 | ||
2366 | if (!iter->pg) | |
2367 | return NULL; | |
2368 | ||
2369 | return iter; | |
2370 | } | |
2371 | ||
2372 | /** | |
2373 | * ftrace_rec_iter_next, get the next record to process. | |
2374 | * @iter: The handle to the iterator. | |
2375 | * | |
2376 | * Returns the next iterator after the given iterator @iter. | |
2377 | */ | |
2378 | struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) | |
2379 | { | |
2380 | iter->index++; | |
2381 | ||
2382 | if (iter->index >= iter->pg->index) { | |
2383 | iter->pg = iter->pg->next; | |
2384 | iter->index = 0; | |
2385 | ||
2386 | /* Could have empty pages */ | |
2387 | while (iter->pg && !iter->pg->index) | |
2388 | iter->pg = iter->pg->next; | |
2389 | } | |
2390 | ||
2391 | if (!iter->pg) | |
2392 | return NULL; | |
2393 | ||
2394 | return iter; | |
2395 | } | |
2396 | ||
2397 | /** | |
2398 | * ftrace_rec_iter_record, get the record at the iterator location | |
2399 | * @iter: The current iterator location | |
2400 | * | |
2401 | * Returns the record that the current @iter is at. | |
2402 | */ | |
2403 | struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) | |
2404 | { | |
2405 | return &iter->pg->records[iter->index]; | |
2406 | } | |
2407 | ||
492a7ea5 | 2408 | static int |
31e88909 | 2409 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 | 2410 | { |
593eb8a2 | 2411 | int ret; |
3c1720f0 | 2412 | |
45a4a237 SR |
2413 | if (unlikely(ftrace_disabled)) |
2414 | return 0; | |
2415 | ||
25aac9dc | 2416 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 2417 | if (ret) { |
4fd3279b | 2418 | ftrace_bug(ret, rec); |
492a7ea5 | 2419 | return 0; |
37ad5084 | 2420 | } |
492a7ea5 | 2421 | return 1; |
3c1720f0 SR |
2422 | } |
2423 | ||
000ab691 SR |
2424 | /* |
2425 | * archs can override this function if they must do something | |
2426 | * before the modifying code is performed. | |
2427 | */ | |
2428 | int __weak ftrace_arch_code_modify_prepare(void) | |
2429 | { | |
2430 | return 0; | |
2431 | } | |
2432 | ||
2433 | /* | |
2434 | * archs can override this function if they must do something | |
2435 | * after the modifying code is performed. | |
2436 | */ | |
2437 | int __weak ftrace_arch_code_modify_post_process(void) | |
2438 | { | |
2439 | return 0; | |
2440 | } | |
2441 | ||
8ed3e2cf | 2442 | void ftrace_modify_all_code(int command) |
3d083395 | 2443 | { |
59338f75 | 2444 | int update = command & FTRACE_UPDATE_TRACE_FUNC; |
cd21067f | 2445 | int err = 0; |
59338f75 SRRH |
2446 | |
2447 | /* | |
2448 | * If the ftrace_caller calls a ftrace_ops func directly, | |
2449 | * we need to make sure that it only traces functions it | |
2450 | * expects to trace. When doing the switch of functions, | |
2451 | * we need to update to the ftrace_ops_list_func first | |
2452 | * before the transition between old and new calls are set, | |
2453 | * as the ftrace_ops_list_func will check the ops hashes | |
2454 | * to make sure the ops are having the right functions | |
2455 | * traced. | |
2456 | */ | |
cd21067f PM |
2457 | if (update) { |
2458 | err = ftrace_update_ftrace_func(ftrace_ops_list_func); | |
2459 | if (FTRACE_WARN_ON(err)) | |
2460 | return; | |
2461 | } | |
59338f75 | 2462 | |
8ed3e2cf | 2463 | if (command & FTRACE_UPDATE_CALLS) |
d61f82d0 | 2464 | ftrace_replace_code(1); |
8ed3e2cf | 2465 | else if (command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
2466 | ftrace_replace_code(0); |
2467 | ||
405e1d83 SRRH |
2468 | if (update && ftrace_trace_function != ftrace_ops_list_func) { |
2469 | function_trace_op = set_function_trace_op; | |
2470 | smp_wmb(); | |
2471 | /* If irqs are disabled, we are in stop machine */ | |
2472 | if (!irqs_disabled()) | |
2473 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
cd21067f PM |
2474 | err = ftrace_update_ftrace_func(ftrace_trace_function); |
2475 | if (FTRACE_WARN_ON(err)) | |
2476 | return; | |
405e1d83 | 2477 | } |
d61f82d0 | 2478 | |
8ed3e2cf | 2479 | if (command & FTRACE_START_FUNC_RET) |
cd21067f | 2480 | err = ftrace_enable_ftrace_graph_caller(); |
8ed3e2cf | 2481 | else if (command & FTRACE_STOP_FUNC_RET) |
cd21067f PM |
2482 | err = ftrace_disable_ftrace_graph_caller(); |
2483 | FTRACE_WARN_ON(err); | |
8ed3e2cf SR |
2484 | } |
2485 | ||
2486 | static int __ftrace_modify_code(void *data) | |
2487 | { | |
2488 | int *command = data; | |
2489 | ||
2490 | ftrace_modify_all_code(*command); | |
5a45cfe1 | 2491 | |
d61f82d0 | 2492 | return 0; |
3d083395 SR |
2493 | } |
2494 | ||
c88fd863 SR |
2495 | /** |
2496 | * ftrace_run_stop_machine, go back to the stop machine method | |
2497 | * @command: The command to tell ftrace what to do | |
2498 | * | |
2499 | * If an arch needs to fall back to the stop machine method, the | |
2500 | * it can call this function. | |
2501 | */ | |
2502 | void ftrace_run_stop_machine(int command) | |
2503 | { | |
2504 | stop_machine(__ftrace_modify_code, &command, NULL); | |
2505 | } | |
2506 | ||
2507 | /** | |
2508 | * arch_ftrace_update_code, modify the code to trace or not trace | |
2509 | * @command: The command that needs to be done | |
2510 | * | |
2511 | * Archs can override this function if it does not need to | |
2512 | * run stop_machine() to modify code. | |
2513 | */ | |
2514 | void __weak arch_ftrace_update_code(int command) | |
2515 | { | |
2516 | ftrace_run_stop_machine(command); | |
2517 | } | |
2518 | ||
e309b41d | 2519 | static void ftrace_run_update_code(int command) |
3d083395 | 2520 | { |
000ab691 SR |
2521 | int ret; |
2522 | ||
2523 | ret = ftrace_arch_code_modify_prepare(); | |
2524 | FTRACE_WARN_ON(ret); | |
2525 | if (ret) | |
2526 | return; | |
2527 | ||
c88fd863 SR |
2528 | /* |
2529 | * By default we use stop_machine() to modify the code. | |
2530 | * But archs can do what ever they want as long as it | |
2531 | * is safe. The stop_machine() is the safest, but also | |
2532 | * produces the most overhead. | |
2533 | */ | |
2534 | arch_ftrace_update_code(command); | |
2535 | ||
000ab691 SR |
2536 | ret = ftrace_arch_code_modify_post_process(); |
2537 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
2538 | } |
2539 | ||
8252ecf3 | 2540 | static void ftrace_run_modify_code(struct ftrace_ops *ops, int command, |
7485058e | 2541 | struct ftrace_ops_hash *old_hash) |
e1effa01 SRRH |
2542 | { |
2543 | ops->flags |= FTRACE_OPS_FL_MODIFYING; | |
7485058e SRRH |
2544 | ops->old_hash.filter_hash = old_hash->filter_hash; |
2545 | ops->old_hash.notrace_hash = old_hash->notrace_hash; | |
e1effa01 | 2546 | ftrace_run_update_code(command); |
8252ecf3 | 2547 | ops->old_hash.filter_hash = NULL; |
7485058e | 2548 | ops->old_hash.notrace_hash = NULL; |
e1effa01 SRRH |
2549 | ops->flags &= ~FTRACE_OPS_FL_MODIFYING; |
2550 | } | |
2551 | ||
d61f82d0 | 2552 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 2553 | static int ftrace_start_up; |
df4fc315 | 2554 | |
12cce594 SRRH |
2555 | void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops) |
2556 | { | |
2557 | } | |
2558 | ||
db0fbadc JS |
2559 | static void control_ops_free(struct ftrace_ops *ops) |
2560 | { | |
2561 | free_percpu(ops->disabled); | |
2562 | } | |
2563 | ||
df4fc315 SR |
2564 | static void ftrace_startup_enable(int command) |
2565 | { | |
2566 | if (saved_ftrace_func != ftrace_trace_function) { | |
2567 | saved_ftrace_func = ftrace_trace_function; | |
2568 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2569 | } | |
2570 | ||
2571 | if (!command || !ftrace_enabled) | |
2572 | return; | |
2573 | ||
2574 | ftrace_run_update_code(command); | |
2575 | } | |
d61f82d0 | 2576 | |
e1effa01 SRRH |
2577 | static void ftrace_startup_all(int command) |
2578 | { | |
2579 | update_all_ops = true; | |
2580 | ftrace_startup_enable(command); | |
2581 | update_all_ops = false; | |
2582 | } | |
2583 | ||
a1cd6173 | 2584 | static int ftrace_startup(struct ftrace_ops *ops, int command) |
3d083395 | 2585 | { |
8a56d776 | 2586 | int ret; |
b848914c | 2587 | |
4eebcc81 | 2588 | if (unlikely(ftrace_disabled)) |
a1cd6173 | 2589 | return -ENODEV; |
4eebcc81 | 2590 | |
8a56d776 SRRH |
2591 | ret = __register_ftrace_function(ops); |
2592 | if (ret) | |
2593 | return ret; | |
2594 | ||
60a7ecf4 | 2595 | ftrace_start_up++; |
30fb6aa7 | 2596 | command |= FTRACE_UPDATE_CALLS; |
d61f82d0 | 2597 | |
e1effa01 SRRH |
2598 | /* |
2599 | * Note that ftrace probes uses this to start up | |
2600 | * and modify functions it will probe. But we still | |
2601 | * set the ADDING flag for modification, as probes | |
2602 | * do not have trampolines. If they add them in the | |
2603 | * future, then the probes will need to distinguish | |
2604 | * between adding and updating probes. | |
2605 | */ | |
2606 | ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING; | |
66209a5b | 2607 | |
f8b8be8a MH |
2608 | ret = ftrace_hash_ipmodify_enable(ops); |
2609 | if (ret < 0) { | |
2610 | /* Rollback registration process */ | |
2611 | __unregister_ftrace_function(ops); | |
2612 | ftrace_start_up--; | |
2613 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; | |
2614 | return ret; | |
2615 | } | |
2616 | ||
66209a5b | 2617 | ftrace_hash_rec_enable(ops, 1); |
ed926f9b | 2618 | |
df4fc315 | 2619 | ftrace_startup_enable(command); |
a1cd6173 | 2620 | |
e1effa01 SRRH |
2621 | ops->flags &= ~FTRACE_OPS_FL_ADDING; |
2622 | ||
a1cd6173 | 2623 | return 0; |
3d083395 SR |
2624 | } |
2625 | ||
8a56d776 | 2626 | static int ftrace_shutdown(struct ftrace_ops *ops, int command) |
3d083395 | 2627 | { |
8a56d776 | 2628 | int ret; |
b848914c | 2629 | |
4eebcc81 | 2630 | if (unlikely(ftrace_disabled)) |
8a56d776 SRRH |
2631 | return -ENODEV; |
2632 | ||
2633 | ret = __unregister_ftrace_function(ops); | |
2634 | if (ret) | |
2635 | return ret; | |
4eebcc81 | 2636 | |
60a7ecf4 | 2637 | ftrace_start_up--; |
9ea1a153 FW |
2638 | /* |
2639 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
2640 | * critical but the ftrace_call callers may be never nopped again after | |
2641 | * further ftrace uses. | |
2642 | */ | |
2643 | WARN_ON_ONCE(ftrace_start_up < 0); | |
2644 | ||
f8b8be8a MH |
2645 | /* Disabling ipmodify never fails */ |
2646 | ftrace_hash_ipmodify_disable(ops); | |
66209a5b | 2647 | ftrace_hash_rec_disable(ops, 1); |
ed926f9b | 2648 | |
a737e6dd | 2649 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
b848914c | 2650 | |
30fb6aa7 | 2651 | command |= FTRACE_UPDATE_CALLS; |
3d083395 | 2652 | |
d61f82d0 SR |
2653 | if (saved_ftrace_func != ftrace_trace_function) { |
2654 | saved_ftrace_func = ftrace_trace_function; | |
2655 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2656 | } | |
3d083395 | 2657 | |
a4c35ed2 SRRH |
2658 | if (!command || !ftrace_enabled) { |
2659 | /* | |
2660 | * If these are control ops, they still need their | |
2661 | * per_cpu field freed. Since, function tracing is | |
2662 | * not currently active, we can just free them | |
2663 | * without synchronizing all CPUs. | |
2664 | */ | |
2665 | if (ops->flags & FTRACE_OPS_FL_CONTROL) | |
2666 | control_ops_free(ops); | |
8a56d776 | 2667 | return 0; |
a4c35ed2 | 2668 | } |
d61f82d0 | 2669 | |
79922b80 SRRH |
2670 | /* |
2671 | * If the ops uses a trampoline, then it needs to be | |
2672 | * tested first on update. | |
2673 | */ | |
e1effa01 | 2674 | ops->flags |= FTRACE_OPS_FL_REMOVING; |
79922b80 SRRH |
2675 | removed_ops = ops; |
2676 | ||
fef5aeee SRRH |
2677 | /* The trampoline logic checks the old hashes */ |
2678 | ops->old_hash.filter_hash = ops->func_hash->filter_hash; | |
2679 | ops->old_hash.notrace_hash = ops->func_hash->notrace_hash; | |
2680 | ||
d61f82d0 | 2681 | ftrace_run_update_code(command); |
a4c35ed2 | 2682 | |
84bde62c SRRH |
2683 | /* |
2684 | * If there's no more ops registered with ftrace, run a | |
2685 | * sanity check to make sure all rec flags are cleared. | |
2686 | */ | |
2687 | if (ftrace_ops_list == &ftrace_list_end) { | |
2688 | struct ftrace_page *pg; | |
2689 | struct dyn_ftrace *rec; | |
2690 | ||
2691 | do_for_each_ftrace_rec(pg, rec) { | |
2692 | if (FTRACE_WARN_ON_ONCE(rec->flags)) | |
2693 | pr_warn(" %pS flags:%lx\n", | |
2694 | (void *)rec->ip, rec->flags); | |
2695 | } while_for_each_ftrace_rec(); | |
2696 | } | |
2697 | ||
fef5aeee SRRH |
2698 | ops->old_hash.filter_hash = NULL; |
2699 | ops->old_hash.notrace_hash = NULL; | |
2700 | ||
2701 | removed_ops = NULL; | |
e1effa01 | 2702 | ops->flags &= ~FTRACE_OPS_FL_REMOVING; |
79922b80 | 2703 | |
a4c35ed2 SRRH |
2704 | /* |
2705 | * Dynamic ops may be freed, we must make sure that all | |
2706 | * callers are done before leaving this function. | |
2707 | * The same goes for freeing the per_cpu data of the control | |
2708 | * ops. | |
2709 | * | |
2710 | * Again, normal synchronize_sched() is not good enough. | |
2711 | * We need to do a hard force of sched synchronization. | |
2712 | * This is because we use preempt_disable() to do RCU, but | |
2713 | * the function tracers can be called where RCU is not watching | |
2714 | * (like before user_exit()). We can not rely on the RCU | |
2715 | * infrastructure to do the synchronization, thus we must do it | |
2716 | * ourselves. | |
2717 | */ | |
2718 | if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_CONTROL)) { | |
2719 | schedule_on_each_cpu(ftrace_sync); | |
2720 | ||
12cce594 SRRH |
2721 | arch_ftrace_trampoline_free(ops); |
2722 | ||
a4c35ed2 SRRH |
2723 | if (ops->flags & FTRACE_OPS_FL_CONTROL) |
2724 | control_ops_free(ops); | |
2725 | } | |
2726 | ||
8a56d776 | 2727 | return 0; |
3d083395 SR |
2728 | } |
2729 | ||
e309b41d | 2730 | static void ftrace_startup_sysctl(void) |
b0fc494f | 2731 | { |
1619dc3f PA |
2732 | int command; |
2733 | ||
4eebcc81 SR |
2734 | if (unlikely(ftrace_disabled)) |
2735 | return; | |
2736 | ||
d61f82d0 SR |
2737 | /* Force update next time */ |
2738 | saved_ftrace_func = NULL; | |
60a7ecf4 | 2739 | /* ftrace_start_up is true if we want ftrace running */ |
1619dc3f PA |
2740 | if (ftrace_start_up) { |
2741 | command = FTRACE_UPDATE_CALLS; | |
2742 | if (ftrace_graph_active) | |
2743 | command |= FTRACE_START_FUNC_RET; | |
524a3868 | 2744 | ftrace_startup_enable(command); |
1619dc3f | 2745 | } |
b0fc494f SR |
2746 | } |
2747 | ||
e309b41d | 2748 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 2749 | { |
1619dc3f PA |
2750 | int command; |
2751 | ||
4eebcc81 SR |
2752 | if (unlikely(ftrace_disabled)) |
2753 | return; | |
2754 | ||
60a7ecf4 | 2755 | /* ftrace_start_up is true if ftrace is running */ |
1619dc3f PA |
2756 | if (ftrace_start_up) { |
2757 | command = FTRACE_DISABLE_CALLS; | |
2758 | if (ftrace_graph_active) | |
2759 | command |= FTRACE_STOP_FUNC_RET; | |
2760 | ftrace_run_update_code(command); | |
2761 | } | |
b0fc494f SR |
2762 | } |
2763 | ||
3d083395 | 2764 | static cycle_t ftrace_update_time; |
3d083395 SR |
2765 | unsigned long ftrace_update_tot_cnt; |
2766 | ||
8c4f3c3f | 2767 | static inline int ops_traces_mod(struct ftrace_ops *ops) |
f7bc8b61 | 2768 | { |
8c4f3c3f SRRH |
2769 | /* |
2770 | * Filter_hash being empty will default to trace module. | |
2771 | * But notrace hash requires a test of individual module functions. | |
2772 | */ | |
33b7f99c SRRH |
2773 | return ftrace_hash_empty(ops->func_hash->filter_hash) && |
2774 | ftrace_hash_empty(ops->func_hash->notrace_hash); | |
8c4f3c3f SRRH |
2775 | } |
2776 | ||
2777 | /* | |
2778 | * Check if the current ops references the record. | |
2779 | * | |
2780 | * If the ops traces all functions, then it was already accounted for. | |
2781 | * If the ops does not trace the current record function, skip it. | |
2782 | * If the ops ignores the function via notrace filter, skip it. | |
2783 | */ | |
2784 | static inline bool | |
2785 | ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec) | |
2786 | { | |
2787 | /* If ops isn't enabled, ignore it */ | |
2788 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
2789 | return 0; | |
2790 | ||
2791 | /* If ops traces all mods, we already accounted for it */ | |
2792 | if (ops_traces_mod(ops)) | |
2793 | return 0; | |
2794 | ||
2795 | /* The function must be in the filter */ | |
33b7f99c SRRH |
2796 | if (!ftrace_hash_empty(ops->func_hash->filter_hash) && |
2797 | !ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip)) | |
8c4f3c3f | 2798 | return 0; |
f7bc8b61 | 2799 | |
8c4f3c3f | 2800 | /* If in notrace hash, we ignore it too */ |
33b7f99c | 2801 | if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip)) |
8c4f3c3f SRRH |
2802 | return 0; |
2803 | ||
2804 | return 1; | |
2805 | } | |
2806 | ||
2807 | static int referenced_filters(struct dyn_ftrace *rec) | |
2808 | { | |
2809 | struct ftrace_ops *ops; | |
2810 | int cnt = 0; | |
2811 | ||
2812 | for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) { | |
2813 | if (ops_references_rec(ops, rec)) | |
2814 | cnt++; | |
2815 | } | |
2816 | ||
2817 | return cnt; | |
f7bc8b61 SR |
2818 | } |
2819 | ||
1dc43cf0 | 2820 | static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs) |
3d083395 | 2821 | { |
85ae32ae | 2822 | struct ftrace_page *pg; |
e94142a6 | 2823 | struct dyn_ftrace *p; |
f22f9a89 | 2824 | cycle_t start, stop; |
1dc43cf0 | 2825 | unsigned long update_cnt = 0; |
f7bc8b61 | 2826 | unsigned long ref = 0; |
8c4f3c3f | 2827 | bool test = false; |
85ae32ae | 2828 | int i; |
f7bc8b61 SR |
2829 | |
2830 | /* | |
2831 | * When adding a module, we need to check if tracers are | |
2832 | * currently enabled and if they are set to trace all functions. | |
2833 | * If they are, we need to enable the module functions as well | |
2834 | * as update the reference counts for those function records. | |
2835 | */ | |
2836 | if (mod) { | |
2837 | struct ftrace_ops *ops; | |
2838 | ||
2839 | for (ops = ftrace_ops_list; | |
2840 | ops != &ftrace_list_end; ops = ops->next) { | |
8c4f3c3f SRRH |
2841 | if (ops->flags & FTRACE_OPS_FL_ENABLED) { |
2842 | if (ops_traces_mod(ops)) | |
2843 | ref++; | |
2844 | else | |
2845 | test = true; | |
2846 | } | |
f7bc8b61 SR |
2847 | } |
2848 | } | |
3d083395 | 2849 | |
750ed1a4 | 2850 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 | 2851 | |
1dc43cf0 | 2852 | for (pg = new_pgs; pg; pg = pg->next) { |
3d083395 | 2853 | |
85ae32ae | 2854 | for (i = 0; i < pg->index; i++) { |
8c4f3c3f SRRH |
2855 | int cnt = ref; |
2856 | ||
85ae32ae SR |
2857 | /* If something went wrong, bail without enabling anything */ |
2858 | if (unlikely(ftrace_disabled)) | |
2859 | return -1; | |
f22f9a89 | 2860 | |
85ae32ae | 2861 | p = &pg->records[i]; |
8c4f3c3f SRRH |
2862 | if (test) |
2863 | cnt += referenced_filters(p); | |
2864 | p->flags = cnt; | |
f22f9a89 | 2865 | |
85ae32ae SR |
2866 | /* |
2867 | * Do the initial record conversion from mcount jump | |
2868 | * to the NOP instructions. | |
2869 | */ | |
2870 | if (!ftrace_code_disable(mod, p)) | |
2871 | break; | |
5cb084bb | 2872 | |
1dc43cf0 | 2873 | update_cnt++; |
5cb084bb | 2874 | |
85ae32ae SR |
2875 | /* |
2876 | * If the tracing is enabled, go ahead and enable the record. | |
2877 | * | |
2878 | * The reason not to enable the record immediatelly is the | |
2879 | * inherent check of ftrace_make_nop/ftrace_make_call for | |
2880 | * correct previous instructions. Making first the NOP | |
2881 | * conversion puts the module to the correct state, thus | |
2882 | * passing the ftrace_make_call check. | |
2883 | */ | |
8c4f3c3f | 2884 | if (ftrace_start_up && cnt) { |
85ae32ae SR |
2885 | int failed = __ftrace_replace_code(p, 1); |
2886 | if (failed) | |
4fd3279b | 2887 | ftrace_bug(failed, p); |
85ae32ae | 2888 | } |
5cb084bb | 2889 | } |
3d083395 SR |
2890 | } |
2891 | ||
750ed1a4 | 2892 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 | 2893 | ftrace_update_time = stop - start; |
1dc43cf0 | 2894 | ftrace_update_tot_cnt += update_cnt; |
3d083395 | 2895 | |
16444a8a ACM |
2896 | return 0; |
2897 | } | |
2898 | ||
a7900875 | 2899 | static int ftrace_allocate_records(struct ftrace_page *pg, int count) |
3c1720f0 | 2900 | { |
a7900875 | 2901 | int order; |
3c1720f0 | 2902 | int cnt; |
3c1720f0 | 2903 | |
a7900875 SR |
2904 | if (WARN_ON(!count)) |
2905 | return -EINVAL; | |
2906 | ||
2907 | order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE)); | |
3c1720f0 SR |
2908 | |
2909 | /* | |
a7900875 SR |
2910 | * We want to fill as much as possible. No more than a page |
2911 | * may be empty. | |
3c1720f0 | 2912 | */ |
a7900875 SR |
2913 | while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE) |
2914 | order--; | |
3c1720f0 | 2915 | |
a7900875 SR |
2916 | again: |
2917 | pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order); | |
3c1720f0 | 2918 | |
a7900875 SR |
2919 | if (!pg->records) { |
2920 | /* if we can't allocate this size, try something smaller */ | |
2921 | if (!order) | |
2922 | return -ENOMEM; | |
2923 | order >>= 1; | |
2924 | goto again; | |
2925 | } | |
3c1720f0 | 2926 | |
a7900875 SR |
2927 | cnt = (PAGE_SIZE << order) / ENTRY_SIZE; |
2928 | pg->size = cnt; | |
3c1720f0 | 2929 | |
a7900875 SR |
2930 | if (cnt > count) |
2931 | cnt = count; | |
2932 | ||
2933 | return cnt; | |
2934 | } | |
2935 | ||
2936 | static struct ftrace_page * | |
2937 | ftrace_allocate_pages(unsigned long num_to_init) | |
2938 | { | |
2939 | struct ftrace_page *start_pg; | |
2940 | struct ftrace_page *pg; | |
2941 | int order; | |
2942 | int cnt; | |
2943 | ||
2944 | if (!num_to_init) | |
2945 | return 0; | |
2946 | ||
2947 | start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL); | |
2948 | if (!pg) | |
2949 | return NULL; | |
2950 | ||
2951 | /* | |
2952 | * Try to allocate as much as possible in one continues | |
2953 | * location that fills in all of the space. We want to | |
2954 | * waste as little space as possible. | |
2955 | */ | |
2956 | for (;;) { | |
2957 | cnt = ftrace_allocate_records(pg, num_to_init); | |
2958 | if (cnt < 0) | |
2959 | goto free_pages; | |
2960 | ||
2961 | num_to_init -= cnt; | |
2962 | if (!num_to_init) | |
3c1720f0 SR |
2963 | break; |
2964 | ||
a7900875 SR |
2965 | pg->next = kzalloc(sizeof(*pg), GFP_KERNEL); |
2966 | if (!pg->next) | |
2967 | goto free_pages; | |
2968 | ||
3c1720f0 SR |
2969 | pg = pg->next; |
2970 | } | |
2971 | ||
a7900875 SR |
2972 | return start_pg; |
2973 | ||
2974 | free_pages: | |
1f61be00 NK |
2975 | pg = start_pg; |
2976 | while (pg) { | |
a7900875 SR |
2977 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
2978 | free_pages((unsigned long)pg->records, order); | |
2979 | start_pg = pg->next; | |
2980 | kfree(pg); | |
2981 | pg = start_pg; | |
2982 | } | |
2983 | pr_info("ftrace: FAILED to allocate memory for functions\n"); | |
2984 | return NULL; | |
2985 | } | |
2986 | ||
5072c59f SR |
2987 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ |
2988 | ||
2989 | struct ftrace_iterator { | |
98c4fd04 | 2990 | loff_t pos; |
4aeb6967 SR |
2991 | loff_t func_pos; |
2992 | struct ftrace_page *pg; | |
2993 | struct dyn_ftrace *func; | |
2994 | struct ftrace_func_probe *probe; | |
2995 | struct trace_parser parser; | |
1cf41dd7 | 2996 | struct ftrace_hash *hash; |
33dc9b12 | 2997 | struct ftrace_ops *ops; |
4aeb6967 SR |
2998 | int hidx; |
2999 | int idx; | |
3000 | unsigned flags; | |
5072c59f SR |
3001 | }; |
3002 | ||
8fc0c701 | 3003 | static void * |
4aeb6967 | 3004 | t_hash_next(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
3005 | { |
3006 | struct ftrace_iterator *iter = m->private; | |
4aeb6967 | 3007 | struct hlist_node *hnd = NULL; |
8fc0c701 SR |
3008 | struct hlist_head *hhd; |
3009 | ||
8fc0c701 | 3010 | (*pos)++; |
98c4fd04 | 3011 | iter->pos = *pos; |
8fc0c701 | 3012 | |
4aeb6967 SR |
3013 | if (iter->probe) |
3014 | hnd = &iter->probe->node; | |
8fc0c701 SR |
3015 | retry: |
3016 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
3017 | return NULL; | |
3018 | ||
3019 | hhd = &ftrace_func_hash[iter->hidx]; | |
3020 | ||
3021 | if (hlist_empty(hhd)) { | |
3022 | iter->hidx++; | |
3023 | hnd = NULL; | |
3024 | goto retry; | |
3025 | } | |
3026 | ||
3027 | if (!hnd) | |
3028 | hnd = hhd->first; | |
3029 | else { | |
3030 | hnd = hnd->next; | |
3031 | if (!hnd) { | |
3032 | iter->hidx++; | |
3033 | goto retry; | |
3034 | } | |
3035 | } | |
3036 | ||
4aeb6967 SR |
3037 | if (WARN_ON_ONCE(!hnd)) |
3038 | return NULL; | |
3039 | ||
3040 | iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node); | |
3041 | ||
3042 | return iter; | |
8fc0c701 SR |
3043 | } |
3044 | ||
3045 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
3046 | { | |
3047 | struct ftrace_iterator *iter = m->private; | |
3048 | void *p = NULL; | |
d82d6244 LZ |
3049 | loff_t l; |
3050 | ||
69a3083c SR |
3051 | if (!(iter->flags & FTRACE_ITER_DO_HASH)) |
3052 | return NULL; | |
3053 | ||
2bccfffd SR |
3054 | if (iter->func_pos > *pos) |
3055 | return NULL; | |
8fc0c701 | 3056 | |
d82d6244 | 3057 | iter->hidx = 0; |
2bccfffd | 3058 | for (l = 0; l <= (*pos - iter->func_pos); ) { |
4aeb6967 | 3059 | p = t_hash_next(m, &l); |
d82d6244 LZ |
3060 | if (!p) |
3061 | break; | |
3062 | } | |
4aeb6967 SR |
3063 | if (!p) |
3064 | return NULL; | |
3065 | ||
98c4fd04 SR |
3066 | /* Only set this if we have an item */ |
3067 | iter->flags |= FTRACE_ITER_HASH; | |
3068 | ||
4aeb6967 | 3069 | return iter; |
8fc0c701 SR |
3070 | } |
3071 | ||
4aeb6967 SR |
3072 | static int |
3073 | t_hash_show(struct seq_file *m, struct ftrace_iterator *iter) | |
8fc0c701 | 3074 | { |
b6887d79 | 3075 | struct ftrace_func_probe *rec; |
8fc0c701 | 3076 | |
4aeb6967 SR |
3077 | rec = iter->probe; |
3078 | if (WARN_ON_ONCE(!rec)) | |
3079 | return -EIO; | |
8fc0c701 | 3080 | |
809dcf29 SR |
3081 | if (rec->ops->print) |
3082 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
3083 | ||
b375a11a | 3084 | seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func); |
8fc0c701 SR |
3085 | |
3086 | if (rec->data) | |
3087 | seq_printf(m, ":%p", rec->data); | |
3088 | seq_putc(m, '\n'); | |
3089 | ||
3090 | return 0; | |
3091 | } | |
3092 | ||
e309b41d | 3093 | static void * |
5072c59f SR |
3094 | t_next(struct seq_file *m, void *v, loff_t *pos) |
3095 | { | |
3096 | struct ftrace_iterator *iter = m->private; | |
fc13cb0c | 3097 | struct ftrace_ops *ops = iter->ops; |
5072c59f SR |
3098 | struct dyn_ftrace *rec = NULL; |
3099 | ||
45a4a237 SR |
3100 | if (unlikely(ftrace_disabled)) |
3101 | return NULL; | |
3102 | ||
8fc0c701 | 3103 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 3104 | return t_hash_next(m, pos); |
8fc0c701 | 3105 | |
5072c59f | 3106 | (*pos)++; |
1106b699 | 3107 | iter->pos = iter->func_pos = *pos; |
5072c59f | 3108 | |
0c75a3ed | 3109 | if (iter->flags & FTRACE_ITER_PRINTALL) |
57c072c7 | 3110 | return t_hash_start(m, pos); |
0c75a3ed | 3111 | |
5072c59f SR |
3112 | retry: |
3113 | if (iter->idx >= iter->pg->index) { | |
3114 | if (iter->pg->next) { | |
3115 | iter->pg = iter->pg->next; | |
3116 | iter->idx = 0; | |
3117 | goto retry; | |
3118 | } | |
3119 | } else { | |
3120 | rec = &iter->pg->records[iter->idx++]; | |
32082309 | 3121 | if (((iter->flags & FTRACE_ITER_FILTER) && |
33b7f99c | 3122 | !(ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))) || |
0183fb1c | 3123 | |
41c52c0d | 3124 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
33b7f99c | 3125 | !ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip)) || |
647bcd03 SR |
3126 | |
3127 | ((iter->flags & FTRACE_ITER_ENABLED) && | |
23ea9c4d | 3128 | !(rec->flags & FTRACE_FL_ENABLED))) { |
647bcd03 | 3129 | |
5072c59f SR |
3130 | rec = NULL; |
3131 | goto retry; | |
3132 | } | |
3133 | } | |
3134 | ||
4aeb6967 | 3135 | if (!rec) |
57c072c7 | 3136 | return t_hash_start(m, pos); |
4aeb6967 SR |
3137 | |
3138 | iter->func = rec; | |
3139 | ||
3140 | return iter; | |
5072c59f SR |
3141 | } |
3142 | ||
98c4fd04 SR |
3143 | static void reset_iter_read(struct ftrace_iterator *iter) |
3144 | { | |
3145 | iter->pos = 0; | |
3146 | iter->func_pos = 0; | |
70f77b3f | 3147 | iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_HASH); |
5072c59f SR |
3148 | } |
3149 | ||
3150 | static void *t_start(struct seq_file *m, loff_t *pos) | |
3151 | { | |
3152 | struct ftrace_iterator *iter = m->private; | |
fc13cb0c | 3153 | struct ftrace_ops *ops = iter->ops; |
5072c59f | 3154 | void *p = NULL; |
694ce0a5 | 3155 | loff_t l; |
5072c59f | 3156 | |
8fc0c701 | 3157 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
3158 | |
3159 | if (unlikely(ftrace_disabled)) | |
3160 | return NULL; | |
3161 | ||
98c4fd04 SR |
3162 | /* |
3163 | * If an lseek was done, then reset and start from beginning. | |
3164 | */ | |
3165 | if (*pos < iter->pos) | |
3166 | reset_iter_read(iter); | |
3167 | ||
0c75a3ed SR |
3168 | /* |
3169 | * For set_ftrace_filter reading, if we have the filter | |
3170 | * off, we can short cut and just print out that all | |
3171 | * functions are enabled. | |
3172 | */ | |
8c006cf7 | 3173 | if ((iter->flags & FTRACE_ITER_FILTER && |
33b7f99c | 3174 | ftrace_hash_empty(ops->func_hash->filter_hash)) || |
8c006cf7 | 3175 | (iter->flags & FTRACE_ITER_NOTRACE && |
33b7f99c | 3176 | ftrace_hash_empty(ops->func_hash->notrace_hash))) { |
0c75a3ed | 3177 | if (*pos > 0) |
8fc0c701 | 3178 | return t_hash_start(m, pos); |
0c75a3ed | 3179 | iter->flags |= FTRACE_ITER_PRINTALL; |
df091625 CW |
3180 | /* reset in case of seek/pread */ |
3181 | iter->flags &= ~FTRACE_ITER_HASH; | |
0c75a3ed SR |
3182 | return iter; |
3183 | } | |
3184 | ||
8fc0c701 SR |
3185 | if (iter->flags & FTRACE_ITER_HASH) |
3186 | return t_hash_start(m, pos); | |
3187 | ||
98c4fd04 SR |
3188 | /* |
3189 | * Unfortunately, we need to restart at ftrace_pages_start | |
3190 | * every time we let go of the ftrace_mutex. This is because | |
3191 | * those pointers can change without the lock. | |
3192 | */ | |
694ce0a5 LZ |
3193 | iter->pg = ftrace_pages_start; |
3194 | iter->idx = 0; | |
3195 | for (l = 0; l <= *pos; ) { | |
3196 | p = t_next(m, p, &l); | |
3197 | if (!p) | |
3198 | break; | |
50cdaf08 | 3199 | } |
5821e1b7 | 3200 | |
69a3083c SR |
3201 | if (!p) |
3202 | return t_hash_start(m, pos); | |
4aeb6967 SR |
3203 | |
3204 | return iter; | |
5072c59f SR |
3205 | } |
3206 | ||
3207 | static void t_stop(struct seq_file *m, void *p) | |
3208 | { | |
8fc0c701 | 3209 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
3210 | } |
3211 | ||
15d5b02c SRRH |
3212 | void * __weak |
3213 | arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec) | |
3214 | { | |
3215 | return NULL; | |
3216 | } | |
3217 | ||
3218 | static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops, | |
3219 | struct dyn_ftrace *rec) | |
3220 | { | |
3221 | void *ptr; | |
3222 | ||
3223 | ptr = arch_ftrace_trampoline_func(ops, rec); | |
3224 | if (ptr) | |
3225 | seq_printf(m, " ->%pS", ptr); | |
3226 | } | |
3227 | ||
5072c59f SR |
3228 | static int t_show(struct seq_file *m, void *v) |
3229 | { | |
0c75a3ed | 3230 | struct ftrace_iterator *iter = m->private; |
4aeb6967 | 3231 | struct dyn_ftrace *rec; |
5072c59f | 3232 | |
8fc0c701 | 3233 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 3234 | return t_hash_show(m, iter); |
8fc0c701 | 3235 | |
0c75a3ed | 3236 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
8c006cf7 | 3237 | if (iter->flags & FTRACE_ITER_NOTRACE) |
fa6f0cc7 | 3238 | seq_puts(m, "#### no functions disabled ####\n"); |
8c006cf7 | 3239 | else |
fa6f0cc7 | 3240 | seq_puts(m, "#### all functions enabled ####\n"); |
0c75a3ed SR |
3241 | return 0; |
3242 | } | |
3243 | ||
4aeb6967 SR |
3244 | rec = iter->func; |
3245 | ||
5072c59f SR |
3246 | if (!rec) |
3247 | return 0; | |
3248 | ||
647bcd03 | 3249 | seq_printf(m, "%ps", (void *)rec->ip); |
9674b2fa | 3250 | if (iter->flags & FTRACE_ITER_ENABLED) { |
15d5b02c SRRH |
3251 | struct ftrace_ops *ops = NULL; |
3252 | ||
f8b8be8a | 3253 | seq_printf(m, " (%ld)%s%s", |
0376bde1 | 3254 | ftrace_rec_count(rec), |
f8b8be8a MH |
3255 | rec->flags & FTRACE_FL_REGS ? " R" : " ", |
3256 | rec->flags & FTRACE_FL_IPMODIFY ? " I" : " "); | |
9674b2fa | 3257 | if (rec->flags & FTRACE_FL_TRAMP_EN) { |
5fecaa04 | 3258 | ops = ftrace_find_tramp_ops_any(rec); |
fef5aeee | 3259 | if (ops) |
9674b2fa SRRH |
3260 | seq_printf(m, "\ttramp: %pS", |
3261 | (void *)ops->trampoline); | |
3262 | else | |
fa6f0cc7 | 3263 | seq_puts(m, "\ttramp: ERROR!"); |
15d5b02c | 3264 | |
9674b2fa | 3265 | } |
15d5b02c | 3266 | add_trampoline_func(m, ops, rec); |
9674b2fa SRRH |
3267 | } |
3268 | ||
fa6f0cc7 | 3269 | seq_putc(m, '\n'); |
5072c59f SR |
3270 | |
3271 | return 0; | |
3272 | } | |
3273 | ||
88e9d34c | 3274 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
3275 | .start = t_start, |
3276 | .next = t_next, | |
3277 | .stop = t_stop, | |
3278 | .show = t_show, | |
3279 | }; | |
3280 | ||
e309b41d | 3281 | static int |
5072c59f SR |
3282 | ftrace_avail_open(struct inode *inode, struct file *file) |
3283 | { | |
3284 | struct ftrace_iterator *iter; | |
5072c59f | 3285 | |
4eebcc81 SR |
3286 | if (unlikely(ftrace_disabled)) |
3287 | return -ENODEV; | |
3288 | ||
50e18b94 JO |
3289 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
3290 | if (iter) { | |
3291 | iter->pg = ftrace_pages_start; | |
3292 | iter->ops = &global_ops; | |
4bf39a94 | 3293 | } |
5072c59f | 3294 | |
50e18b94 | 3295 | return iter ? 0 : -ENOMEM; |
5072c59f SR |
3296 | } |
3297 | ||
647bcd03 SR |
3298 | static int |
3299 | ftrace_enabled_open(struct inode *inode, struct file *file) | |
3300 | { | |
3301 | struct ftrace_iterator *iter; | |
647bcd03 | 3302 | |
50e18b94 JO |
3303 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
3304 | if (iter) { | |
3305 | iter->pg = ftrace_pages_start; | |
3306 | iter->flags = FTRACE_ITER_ENABLED; | |
3307 | iter->ops = &global_ops; | |
647bcd03 SR |
3308 | } |
3309 | ||
50e18b94 | 3310 | return iter ? 0 : -ENOMEM; |
647bcd03 SR |
3311 | } |
3312 | ||
fc13cb0c SR |
3313 | /** |
3314 | * ftrace_regex_open - initialize function tracer filter files | |
3315 | * @ops: The ftrace_ops that hold the hash filters | |
3316 | * @flag: The type of filter to process | |
3317 | * @inode: The inode, usually passed in to your open routine | |
3318 | * @file: The file, usually passed in to your open routine | |
3319 | * | |
3320 | * ftrace_regex_open() initializes the filter files for the | |
3321 | * @ops. Depending on @flag it may process the filter hash or | |
3322 | * the notrace hash of @ops. With this called from the open | |
3323 | * routine, you can use ftrace_filter_write() for the write | |
3324 | * routine if @flag has FTRACE_ITER_FILTER set, or | |
3325 | * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set. | |
098c879e | 3326 | * tracing_lseek() should be used as the lseek routine, and |
fc13cb0c SR |
3327 | * release must call ftrace_regex_release(). |
3328 | */ | |
3329 | int | |
f45948e8 | 3330 | ftrace_regex_open(struct ftrace_ops *ops, int flag, |
1cf41dd7 | 3331 | struct inode *inode, struct file *file) |
5072c59f SR |
3332 | { |
3333 | struct ftrace_iterator *iter; | |
f45948e8 | 3334 | struct ftrace_hash *hash; |
5072c59f SR |
3335 | int ret = 0; |
3336 | ||
f04f24fb MH |
3337 | ftrace_ops_init(ops); |
3338 | ||
4eebcc81 SR |
3339 | if (unlikely(ftrace_disabled)) |
3340 | return -ENODEV; | |
3341 | ||
5072c59f SR |
3342 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
3343 | if (!iter) | |
3344 | return -ENOMEM; | |
3345 | ||
689fd8b6 | 3346 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) { |
3347 | kfree(iter); | |
3348 | return -ENOMEM; | |
3349 | } | |
3350 | ||
3f2367ba MH |
3351 | iter->ops = ops; |
3352 | iter->flags = flag; | |
3353 | ||
33b7f99c | 3354 | mutex_lock(&ops->func_hash->regex_lock); |
3f2367ba | 3355 | |
f45948e8 | 3356 | if (flag & FTRACE_ITER_NOTRACE) |
33b7f99c | 3357 | hash = ops->func_hash->notrace_hash; |
f45948e8 | 3358 | else |
33b7f99c | 3359 | hash = ops->func_hash->filter_hash; |
f45948e8 | 3360 | |
33dc9b12 | 3361 | if (file->f_mode & FMODE_WRITE) { |
ef2fbe16 NK |
3362 | const int size_bits = FTRACE_HASH_DEFAULT_BITS; |
3363 | ||
3364 | if (file->f_flags & O_TRUNC) | |
3365 | iter->hash = alloc_ftrace_hash(size_bits); | |
3366 | else | |
3367 | iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash); | |
3368 | ||
33dc9b12 SR |
3369 | if (!iter->hash) { |
3370 | trace_parser_put(&iter->parser); | |
3371 | kfree(iter); | |
3f2367ba MH |
3372 | ret = -ENOMEM; |
3373 | goto out_unlock; | |
33dc9b12 SR |
3374 | } |
3375 | } | |
1cf41dd7 | 3376 | |
5072c59f SR |
3377 | if (file->f_mode & FMODE_READ) { |
3378 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
3379 | |
3380 | ret = seq_open(file, &show_ftrace_seq_ops); | |
3381 | if (!ret) { | |
3382 | struct seq_file *m = file->private_data; | |
3383 | m->private = iter; | |
79fe249c | 3384 | } else { |
33dc9b12 SR |
3385 | /* Failed */ |
3386 | free_ftrace_hash(iter->hash); | |
79fe249c | 3387 | trace_parser_put(&iter->parser); |
5072c59f | 3388 | kfree(iter); |
79fe249c | 3389 | } |
5072c59f SR |
3390 | } else |
3391 | file->private_data = iter; | |
3f2367ba MH |
3392 | |
3393 | out_unlock: | |
33b7f99c | 3394 | mutex_unlock(&ops->func_hash->regex_lock); |
5072c59f SR |
3395 | |
3396 | return ret; | |
3397 | } | |
3398 | ||
41c52c0d SR |
3399 | static int |
3400 | ftrace_filter_open(struct inode *inode, struct file *file) | |
3401 | { | |
e3b3e2e8 SRRH |
3402 | struct ftrace_ops *ops = inode->i_private; |
3403 | ||
3404 | return ftrace_regex_open(ops, | |
69a3083c SR |
3405 | FTRACE_ITER_FILTER | FTRACE_ITER_DO_HASH, |
3406 | inode, file); | |
41c52c0d SR |
3407 | } |
3408 | ||
3409 | static int | |
3410 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
3411 | { | |
e3b3e2e8 SRRH |
3412 | struct ftrace_ops *ops = inode->i_private; |
3413 | ||
3414 | return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE, | |
1cf41dd7 | 3415 | inode, file); |
41c52c0d SR |
3416 | } |
3417 | ||
64e7c440 | 3418 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 3419 | { |
9f4801e3 | 3420 | int matched = 0; |
751e9983 | 3421 | int slen; |
9f4801e3 | 3422 | |
9f4801e3 SR |
3423 | switch (type) { |
3424 | case MATCH_FULL: | |
3425 | if (strcmp(str, regex) == 0) | |
3426 | matched = 1; | |
3427 | break; | |
3428 | case MATCH_FRONT_ONLY: | |
3429 | if (strncmp(str, regex, len) == 0) | |
3430 | matched = 1; | |
3431 | break; | |
3432 | case MATCH_MIDDLE_ONLY: | |
3433 | if (strstr(str, regex)) | |
3434 | matched = 1; | |
3435 | break; | |
3436 | case MATCH_END_ONLY: | |
751e9983 LZ |
3437 | slen = strlen(str); |
3438 | if (slen >= len && memcmp(str + slen - len, regex, len) == 0) | |
9f4801e3 SR |
3439 | matched = 1; |
3440 | break; | |
3441 | } | |
3442 | ||
3443 | return matched; | |
3444 | } | |
3445 | ||
b448c4e3 | 3446 | static int |
1cf41dd7 | 3447 | enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not) |
996e87be | 3448 | { |
b448c4e3 | 3449 | struct ftrace_func_entry *entry; |
b448c4e3 SR |
3450 | int ret = 0; |
3451 | ||
1cf41dd7 SR |
3452 | entry = ftrace_lookup_ip(hash, rec->ip); |
3453 | if (not) { | |
3454 | /* Do nothing if it doesn't exist */ | |
3455 | if (!entry) | |
3456 | return 0; | |
b448c4e3 | 3457 | |
33dc9b12 | 3458 | free_hash_entry(hash, entry); |
1cf41dd7 SR |
3459 | } else { |
3460 | /* Do nothing if it exists */ | |
3461 | if (entry) | |
3462 | return 0; | |
b448c4e3 | 3463 | |
1cf41dd7 | 3464 | ret = add_hash_entry(hash, rec->ip); |
b448c4e3 SR |
3465 | } |
3466 | return ret; | |
996e87be SR |
3467 | } |
3468 | ||
64e7c440 | 3469 | static int |
b9df92d2 SR |
3470 | ftrace_match_record(struct dyn_ftrace *rec, char *mod, |
3471 | char *regex, int len, int type) | |
64e7c440 SR |
3472 | { |
3473 | char str[KSYM_SYMBOL_LEN]; | |
b9df92d2 SR |
3474 | char *modname; |
3475 | ||
3476 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
3477 | ||
3478 | if (mod) { | |
3479 | /* module lookup requires matching the module */ | |
3480 | if (!modname || strcmp(modname, mod)) | |
3481 | return 0; | |
3482 | ||
3483 | /* blank search means to match all funcs in the mod */ | |
3484 | if (!len) | |
3485 | return 1; | |
3486 | } | |
64e7c440 | 3487 | |
64e7c440 SR |
3488 | return ftrace_match(str, regex, len, type); |
3489 | } | |
3490 | ||
1cf41dd7 SR |
3491 | static int |
3492 | match_records(struct ftrace_hash *hash, char *buff, | |
3493 | int len, char *mod, int not) | |
9f4801e3 | 3494 | { |
b9df92d2 | 3495 | unsigned search_len = 0; |
9f4801e3 SR |
3496 | struct ftrace_page *pg; |
3497 | struct dyn_ftrace *rec; | |
b9df92d2 SR |
3498 | int type = MATCH_FULL; |
3499 | char *search = buff; | |
311d16da | 3500 | int found = 0; |
b448c4e3 | 3501 | int ret; |
9f4801e3 | 3502 | |
b9df92d2 SR |
3503 | if (len) { |
3504 | type = filter_parse_regex(buff, len, &search, ¬); | |
3505 | search_len = strlen(search); | |
3506 | } | |
9f4801e3 | 3507 | |
52baf119 | 3508 | mutex_lock(&ftrace_lock); |
265c831c | 3509 | |
b9df92d2 SR |
3510 | if (unlikely(ftrace_disabled)) |
3511 | goto out_unlock; | |
9f4801e3 | 3512 | |
265c831c | 3513 | do_for_each_ftrace_rec(pg, rec) { |
b9df92d2 | 3514 | if (ftrace_match_record(rec, mod, search, search_len, type)) { |
1cf41dd7 | 3515 | ret = enter_record(hash, rec, not); |
b448c4e3 SR |
3516 | if (ret < 0) { |
3517 | found = ret; | |
3518 | goto out_unlock; | |
3519 | } | |
311d16da | 3520 | found = 1; |
265c831c SR |
3521 | } |
3522 | } while_for_each_ftrace_rec(); | |
b9df92d2 | 3523 | out_unlock: |
52baf119 | 3524 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
3525 | |
3526 | return found; | |
5072c59f SR |
3527 | } |
3528 | ||
64e7c440 | 3529 | static int |
1cf41dd7 | 3530 | ftrace_match_records(struct ftrace_hash *hash, char *buff, int len) |
64e7c440 | 3531 | { |
1cf41dd7 | 3532 | return match_records(hash, buff, len, NULL, 0); |
64e7c440 SR |
3533 | } |
3534 | ||
1cf41dd7 SR |
3535 | static int |
3536 | ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod) | |
64e7c440 | 3537 | { |
64e7c440 | 3538 | int not = 0; |
6a24a244 | 3539 | |
64e7c440 SR |
3540 | /* blank or '*' mean the same */ |
3541 | if (strcmp(buff, "*") == 0) | |
3542 | buff[0] = 0; | |
3543 | ||
3544 | /* handle the case of 'dont filter this module' */ | |
3545 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
3546 | buff[0] = 0; | |
3547 | not = 1; | |
3548 | } | |
3549 | ||
1cf41dd7 | 3550 | return match_records(hash, buff, strlen(buff), mod, not); |
64e7c440 SR |
3551 | } |
3552 | ||
f6180773 SR |
3553 | /* |
3554 | * We register the module command as a template to show others how | |
3555 | * to register the a command as well. | |
3556 | */ | |
3557 | ||
3558 | static int | |
43dd61c9 SR |
3559 | ftrace_mod_callback(struct ftrace_hash *hash, |
3560 | char *func, char *cmd, char *param, int enable) | |
f6180773 SR |
3561 | { |
3562 | char *mod; | |
b448c4e3 | 3563 | int ret = -EINVAL; |
f6180773 SR |
3564 | |
3565 | /* | |
3566 | * cmd == 'mod' because we only registered this func | |
3567 | * for the 'mod' ftrace_func_command. | |
3568 | * But if you register one func with multiple commands, | |
3569 | * you can tell which command was used by the cmd | |
3570 | * parameter. | |
3571 | */ | |
3572 | ||
3573 | /* we must have a module name */ | |
3574 | if (!param) | |
b448c4e3 | 3575 | return ret; |
f6180773 SR |
3576 | |
3577 | mod = strsep(¶m, ":"); | |
3578 | if (!strlen(mod)) | |
b448c4e3 | 3579 | return ret; |
f6180773 | 3580 | |
1cf41dd7 | 3581 | ret = ftrace_match_module_records(hash, func, mod); |
b448c4e3 SR |
3582 | if (!ret) |
3583 | ret = -EINVAL; | |
3584 | if (ret < 0) | |
3585 | return ret; | |
3586 | ||
3587 | return 0; | |
f6180773 SR |
3588 | } |
3589 | ||
3590 | static struct ftrace_func_command ftrace_mod_cmd = { | |
3591 | .name = "mod", | |
3592 | .func = ftrace_mod_callback, | |
3593 | }; | |
3594 | ||
3595 | static int __init ftrace_mod_cmd_init(void) | |
3596 | { | |
3597 | return register_ftrace_command(&ftrace_mod_cmd); | |
3598 | } | |
6f415672 | 3599 | core_initcall(ftrace_mod_cmd_init); |
f6180773 | 3600 | |
2f5f6ad9 | 3601 | static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 3602 | struct ftrace_ops *op, struct pt_regs *pt_regs) |
59df055f | 3603 | { |
b6887d79 | 3604 | struct ftrace_func_probe *entry; |
59df055f | 3605 | struct hlist_head *hhd; |
59df055f | 3606 | unsigned long key; |
59df055f SR |
3607 | |
3608 | key = hash_long(ip, FTRACE_HASH_BITS); | |
3609 | ||
3610 | hhd = &ftrace_func_hash[key]; | |
3611 | ||
3612 | if (hlist_empty(hhd)) | |
3613 | return; | |
3614 | ||
3615 | /* | |
3616 | * Disable preemption for these calls to prevent a RCU grace | |
3617 | * period. This syncs the hash iteration and freeing of items | |
3618 | * on the hash. rcu_read_lock is too dangerous here. | |
3619 | */ | |
5168ae50 | 3620 | preempt_disable_notrace(); |
1bb539ca | 3621 | hlist_for_each_entry_rcu_notrace(entry, hhd, node) { |
59df055f SR |
3622 | if (entry->ip == ip) |
3623 | entry->ops->func(ip, parent_ip, &entry->data); | |
3624 | } | |
5168ae50 | 3625 | preempt_enable_notrace(); |
59df055f SR |
3626 | } |
3627 | ||
b6887d79 | 3628 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 3629 | { |
fb9fb015 | 3630 | .func = function_trace_probe_call, |
f04f24fb | 3631 | .flags = FTRACE_OPS_FL_INITIALIZED, |
33b7f99c | 3632 | INIT_OPS_HASH(trace_probe_ops) |
59df055f SR |
3633 | }; |
3634 | ||
b6887d79 | 3635 | static int ftrace_probe_registered; |
59df055f | 3636 | |
7485058e | 3637 | static void __enable_ftrace_function_probe(struct ftrace_ops_hash *old_hash) |
59df055f | 3638 | { |
b848914c | 3639 | int ret; |
59df055f SR |
3640 | int i; |
3641 | ||
19dd603e SRRH |
3642 | if (ftrace_probe_registered) { |
3643 | /* still need to update the function call sites */ | |
3644 | if (ftrace_enabled) | |
8252ecf3 SRRH |
3645 | ftrace_run_modify_code(&trace_probe_ops, FTRACE_UPDATE_CALLS, |
3646 | old_hash); | |
59df055f | 3647 | return; |
19dd603e | 3648 | } |
59df055f SR |
3649 | |
3650 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
3651 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
3652 | if (hhd->first) | |
3653 | break; | |
3654 | } | |
3655 | /* Nothing registered? */ | |
3656 | if (i == FTRACE_FUNC_HASHSIZE) | |
3657 | return; | |
3658 | ||
8a56d776 | 3659 | ret = ftrace_startup(&trace_probe_ops, 0); |
b848914c | 3660 | |
b6887d79 | 3661 | ftrace_probe_registered = 1; |
59df055f SR |
3662 | } |
3663 | ||
b6887d79 | 3664 | static void __disable_ftrace_function_probe(void) |
59df055f SR |
3665 | { |
3666 | int i; | |
3667 | ||
b6887d79 | 3668 | if (!ftrace_probe_registered) |
59df055f SR |
3669 | return; |
3670 | ||
3671 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
3672 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
3673 | if (hhd->first) | |
3674 | return; | |
3675 | } | |
3676 | ||
3677 | /* no more funcs left */ | |
8a56d776 | 3678 | ftrace_shutdown(&trace_probe_ops, 0); |
b848914c | 3679 | |
b6887d79 | 3680 | ftrace_probe_registered = 0; |
59df055f SR |
3681 | } |
3682 | ||
3683 | ||
7818b388 | 3684 | static void ftrace_free_entry(struct ftrace_func_probe *entry) |
59df055f | 3685 | { |
59df055f | 3686 | if (entry->ops->free) |
e67efb93 | 3687 | entry->ops->free(entry->ops, entry->ip, &entry->data); |
59df055f SR |
3688 | kfree(entry); |
3689 | } | |
3690 | ||
59df055f | 3691 | int |
b6887d79 | 3692 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3693 | void *data) |
3694 | { | |
7485058e | 3695 | struct ftrace_ops_hash old_hash_ops; |
b6887d79 | 3696 | struct ftrace_func_probe *entry; |
33b7f99c | 3697 | struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash; |
3296fc4e | 3698 | struct ftrace_hash *old_hash = *orig_hash; |
e1df4cb6 | 3699 | struct ftrace_hash *hash; |
59df055f SR |
3700 | struct ftrace_page *pg; |
3701 | struct dyn_ftrace *rec; | |
59df055f | 3702 | int type, len, not; |
6a24a244 | 3703 | unsigned long key; |
59df055f SR |
3704 | int count = 0; |
3705 | char *search; | |
e1df4cb6 | 3706 | int ret; |
59df055f | 3707 | |
3f6fe06d | 3708 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
3709 | len = strlen(search); |
3710 | ||
b6887d79 | 3711 | /* we do not support '!' for function probes */ |
59df055f SR |
3712 | if (WARN_ON(not)) |
3713 | return -EINVAL; | |
3714 | ||
33b7f99c | 3715 | mutex_lock(&trace_probe_ops.func_hash->regex_lock); |
59df055f | 3716 | |
7485058e SRRH |
3717 | old_hash_ops.filter_hash = old_hash; |
3718 | /* Probes only have filters */ | |
3719 | old_hash_ops.notrace_hash = NULL; | |
3720 | ||
3296fc4e | 3721 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); |
e1df4cb6 SRRH |
3722 | if (!hash) { |
3723 | count = -ENOMEM; | |
5ae0bf59 | 3724 | goto out; |
e1df4cb6 SRRH |
3725 | } |
3726 | ||
3727 | if (unlikely(ftrace_disabled)) { | |
3728 | count = -ENODEV; | |
5ae0bf59 | 3729 | goto out; |
e1df4cb6 | 3730 | } |
59df055f | 3731 | |
5ae0bf59 SRRH |
3732 | mutex_lock(&ftrace_lock); |
3733 | ||
45a4a237 | 3734 | do_for_each_ftrace_rec(pg, rec) { |
59df055f | 3735 | |
b9df92d2 | 3736 | if (!ftrace_match_record(rec, NULL, search, len, type)) |
59df055f SR |
3737 | continue; |
3738 | ||
3739 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
3740 | if (!entry) { | |
b6887d79 | 3741 | /* If we did not process any, then return error */ |
59df055f SR |
3742 | if (!count) |
3743 | count = -ENOMEM; | |
3744 | goto out_unlock; | |
3745 | } | |
3746 | ||
3747 | count++; | |
3748 | ||
3749 | entry->data = data; | |
3750 | ||
3751 | /* | |
3752 | * The caller might want to do something special | |
3753 | * for each function we find. We call the callback | |
3754 | * to give the caller an opportunity to do so. | |
3755 | */ | |
e67efb93 SRRH |
3756 | if (ops->init) { |
3757 | if (ops->init(ops, rec->ip, &entry->data) < 0) { | |
59df055f SR |
3758 | /* caller does not like this func */ |
3759 | kfree(entry); | |
3760 | continue; | |
3761 | } | |
3762 | } | |
3763 | ||
e1df4cb6 SRRH |
3764 | ret = enter_record(hash, rec, 0); |
3765 | if (ret < 0) { | |
3766 | kfree(entry); | |
3767 | count = ret; | |
3768 | goto out_unlock; | |
3769 | } | |
3770 | ||
59df055f SR |
3771 | entry->ops = ops; |
3772 | entry->ip = rec->ip; | |
3773 | ||
3774 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
3775 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
3776 | ||
3777 | } while_for_each_ftrace_rec(); | |
e1df4cb6 SRRH |
3778 | |
3779 | ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash); | |
8252ecf3 | 3780 | |
7485058e | 3781 | __enable_ftrace_function_probe(&old_hash_ops); |
8252ecf3 | 3782 | |
3296fc4e SRRH |
3783 | if (!ret) |
3784 | free_ftrace_hash_rcu(old_hash); | |
3785 | else | |
e1df4cb6 SRRH |
3786 | count = ret; |
3787 | ||
59df055f | 3788 | out_unlock: |
5ae0bf59 SRRH |
3789 | mutex_unlock(&ftrace_lock); |
3790 | out: | |
33b7f99c | 3791 | mutex_unlock(&trace_probe_ops.func_hash->regex_lock); |
e1df4cb6 | 3792 | free_ftrace_hash(hash); |
59df055f SR |
3793 | |
3794 | return count; | |
3795 | } | |
3796 | ||
3797 | enum { | |
b6887d79 SR |
3798 | PROBE_TEST_FUNC = 1, |
3799 | PROBE_TEST_DATA = 2 | |
59df055f SR |
3800 | }; |
3801 | ||
3802 | static void | |
b6887d79 | 3803 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3804 | void *data, int flags) |
3805 | { | |
e1df4cb6 | 3806 | struct ftrace_func_entry *rec_entry; |
b6887d79 | 3807 | struct ftrace_func_probe *entry; |
7818b388 | 3808 | struct ftrace_func_probe *p; |
33b7f99c | 3809 | struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash; |
3296fc4e | 3810 | struct ftrace_hash *old_hash = *orig_hash; |
7818b388 | 3811 | struct list_head free_list; |
e1df4cb6 | 3812 | struct ftrace_hash *hash; |
b67bfe0d | 3813 | struct hlist_node *tmp; |
59df055f SR |
3814 | char str[KSYM_SYMBOL_LEN]; |
3815 | int type = MATCH_FULL; | |
3816 | int i, len = 0; | |
3817 | char *search; | |
3296fc4e | 3818 | int ret; |
59df055f | 3819 | |
b36461da | 3820 | if (glob && (strcmp(glob, "*") == 0 || !strlen(glob))) |
59df055f | 3821 | glob = NULL; |
b36461da | 3822 | else if (glob) { |
59df055f SR |
3823 | int not; |
3824 | ||
3f6fe06d | 3825 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
3826 | len = strlen(search); |
3827 | ||
b6887d79 | 3828 | /* we do not support '!' for function probes */ |
59df055f SR |
3829 | if (WARN_ON(not)) |
3830 | return; | |
3831 | } | |
3832 | ||
33b7f99c | 3833 | mutex_lock(&trace_probe_ops.func_hash->regex_lock); |
e1df4cb6 SRRH |
3834 | |
3835 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
3836 | if (!hash) | |
3837 | /* Hmm, should report this somehow */ | |
3838 | goto out_unlock; | |
3839 | ||
7818b388 SRRH |
3840 | INIT_LIST_HEAD(&free_list); |
3841 | ||
59df055f SR |
3842 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { |
3843 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
3844 | ||
b67bfe0d | 3845 | hlist_for_each_entry_safe(entry, tmp, hhd, node) { |
59df055f SR |
3846 | |
3847 | /* break up if statements for readability */ | |
b6887d79 | 3848 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
3849 | continue; |
3850 | ||
b6887d79 | 3851 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
3852 | continue; |
3853 | ||
3854 | /* do this last, since it is the most expensive */ | |
3855 | if (glob) { | |
3856 | kallsyms_lookup(entry->ip, NULL, NULL, | |
3857 | NULL, str); | |
3858 | if (!ftrace_match(str, glob, len, type)) | |
3859 | continue; | |
3860 | } | |
3861 | ||
e1df4cb6 SRRH |
3862 | rec_entry = ftrace_lookup_ip(hash, entry->ip); |
3863 | /* It is possible more than one entry had this ip */ | |
3864 | if (rec_entry) | |
3865 | free_hash_entry(hash, rec_entry); | |
3866 | ||
740466bc | 3867 | hlist_del_rcu(&entry->node); |
7818b388 | 3868 | list_add(&entry->free_list, &free_list); |
59df055f SR |
3869 | } |
3870 | } | |
3f2367ba | 3871 | mutex_lock(&ftrace_lock); |
b6887d79 | 3872 | __disable_ftrace_function_probe(); |
e1df4cb6 SRRH |
3873 | /* |
3874 | * Remove after the disable is called. Otherwise, if the last | |
3875 | * probe is removed, a null hash means *all enabled*. | |
3876 | */ | |
3296fc4e | 3877 | ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash); |
7818b388 | 3878 | synchronize_sched(); |
3296fc4e SRRH |
3879 | if (!ret) |
3880 | free_ftrace_hash_rcu(old_hash); | |
3881 | ||
7818b388 SRRH |
3882 | list_for_each_entry_safe(entry, p, &free_list, free_list) { |
3883 | list_del(&entry->free_list); | |
3884 | ftrace_free_entry(entry); | |
3885 | } | |
3f2367ba | 3886 | mutex_unlock(&ftrace_lock); |
7818b388 | 3887 | |
e1df4cb6 | 3888 | out_unlock: |
33b7f99c | 3889 | mutex_unlock(&trace_probe_ops.func_hash->regex_lock); |
e1df4cb6 | 3890 | free_ftrace_hash(hash); |
59df055f SR |
3891 | } |
3892 | ||
3893 | void | |
b6887d79 | 3894 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3895 | void *data) |
3896 | { | |
b6887d79 SR |
3897 | __unregister_ftrace_function_probe(glob, ops, data, |
3898 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
3899 | } |
3900 | ||
3901 | void | |
b6887d79 | 3902 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 3903 | { |
b6887d79 | 3904 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
3905 | } |
3906 | ||
b6887d79 | 3907 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 3908 | { |
b6887d79 | 3909 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
3910 | } |
3911 | ||
f6180773 SR |
3912 | static LIST_HEAD(ftrace_commands); |
3913 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
3914 | ||
38de93ab TZ |
3915 | /* |
3916 | * Currently we only register ftrace commands from __init, so mark this | |
3917 | * __init too. | |
3918 | */ | |
3919 | __init int register_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
3920 | { |
3921 | struct ftrace_func_command *p; | |
3922 | int ret = 0; | |
3923 | ||
3924 | mutex_lock(&ftrace_cmd_mutex); | |
3925 | list_for_each_entry(p, &ftrace_commands, list) { | |
3926 | if (strcmp(cmd->name, p->name) == 0) { | |
3927 | ret = -EBUSY; | |
3928 | goto out_unlock; | |
3929 | } | |
3930 | } | |
3931 | list_add(&cmd->list, &ftrace_commands); | |
3932 | out_unlock: | |
3933 | mutex_unlock(&ftrace_cmd_mutex); | |
3934 | ||
3935 | return ret; | |
3936 | } | |
3937 | ||
38de93ab TZ |
3938 | /* |
3939 | * Currently we only unregister ftrace commands from __init, so mark | |
3940 | * this __init too. | |
3941 | */ | |
3942 | __init int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
3943 | { |
3944 | struct ftrace_func_command *p, *n; | |
3945 | int ret = -ENODEV; | |
3946 | ||
3947 | mutex_lock(&ftrace_cmd_mutex); | |
3948 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
3949 | if (strcmp(cmd->name, p->name) == 0) { | |
3950 | ret = 0; | |
3951 | list_del_init(&p->list); | |
3952 | goto out_unlock; | |
3953 | } | |
3954 | } | |
3955 | out_unlock: | |
3956 | mutex_unlock(&ftrace_cmd_mutex); | |
3957 | ||
3958 | return ret; | |
3959 | } | |
3960 | ||
33dc9b12 SR |
3961 | static int ftrace_process_regex(struct ftrace_hash *hash, |
3962 | char *buff, int len, int enable) | |
64e7c440 | 3963 | { |
f6180773 | 3964 | char *func, *command, *next = buff; |
6a24a244 | 3965 | struct ftrace_func_command *p; |
0aff1c0c | 3966 | int ret = -EINVAL; |
64e7c440 SR |
3967 | |
3968 | func = strsep(&next, ":"); | |
3969 | ||
3970 | if (!next) { | |
1cf41dd7 | 3971 | ret = ftrace_match_records(hash, func, len); |
b448c4e3 SR |
3972 | if (!ret) |
3973 | ret = -EINVAL; | |
3974 | if (ret < 0) | |
3975 | return ret; | |
3976 | return 0; | |
64e7c440 SR |
3977 | } |
3978 | ||
f6180773 | 3979 | /* command found */ |
64e7c440 SR |
3980 | |
3981 | command = strsep(&next, ":"); | |
3982 | ||
f6180773 SR |
3983 | mutex_lock(&ftrace_cmd_mutex); |
3984 | list_for_each_entry(p, &ftrace_commands, list) { | |
3985 | if (strcmp(p->name, command) == 0) { | |
43dd61c9 | 3986 | ret = p->func(hash, func, command, next, enable); |
f6180773 SR |
3987 | goto out_unlock; |
3988 | } | |
64e7c440 | 3989 | } |
f6180773 SR |
3990 | out_unlock: |
3991 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 3992 | |
f6180773 | 3993 | return ret; |
64e7c440 SR |
3994 | } |
3995 | ||
e309b41d | 3996 | static ssize_t |
41c52c0d SR |
3997 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
3998 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
3999 | { |
4000 | struct ftrace_iterator *iter; | |
689fd8b6 | 4001 | struct trace_parser *parser; |
4002 | ssize_t ret, read; | |
5072c59f | 4003 | |
4ba7978e | 4004 | if (!cnt) |
5072c59f SR |
4005 | return 0; |
4006 | ||
5072c59f SR |
4007 | if (file->f_mode & FMODE_READ) { |
4008 | struct seq_file *m = file->private_data; | |
4009 | iter = m->private; | |
4010 | } else | |
4011 | iter = file->private_data; | |
4012 | ||
f04f24fb | 4013 | if (unlikely(ftrace_disabled)) |
3f2367ba MH |
4014 | return -ENODEV; |
4015 | ||
4016 | /* iter->hash is a local copy, so we don't need regex_lock */ | |
f04f24fb | 4017 | |
689fd8b6 | 4018 | parser = &iter->parser; |
4019 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 4020 | |
4ba7978e | 4021 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 4022 | !trace_parser_cont(parser)) { |
33dc9b12 | 4023 | ret = ftrace_process_regex(iter->hash, parser->buffer, |
689fd8b6 | 4024 | parser->idx, enable); |
313254a9 | 4025 | trace_parser_clear(parser); |
7c088b51 | 4026 | if (ret < 0) |
3f2367ba | 4027 | goto out; |
eda1e328 | 4028 | } |
5072c59f | 4029 | |
5072c59f | 4030 | ret = read; |
3f2367ba | 4031 | out: |
5072c59f SR |
4032 | return ret; |
4033 | } | |
4034 | ||
fc13cb0c | 4035 | ssize_t |
41c52c0d SR |
4036 | ftrace_filter_write(struct file *file, const char __user *ubuf, |
4037 | size_t cnt, loff_t *ppos) | |
4038 | { | |
4039 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
4040 | } | |
4041 | ||
fc13cb0c | 4042 | ssize_t |
41c52c0d SR |
4043 | ftrace_notrace_write(struct file *file, const char __user *ubuf, |
4044 | size_t cnt, loff_t *ppos) | |
4045 | { | |
4046 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
4047 | } | |
4048 | ||
33dc9b12 | 4049 | static int |
647664ea MH |
4050 | ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) |
4051 | { | |
4052 | struct ftrace_func_entry *entry; | |
4053 | ||
4054 | if (!ftrace_location(ip)) | |
4055 | return -EINVAL; | |
4056 | ||
4057 | if (remove) { | |
4058 | entry = ftrace_lookup_ip(hash, ip); | |
4059 | if (!entry) | |
4060 | return -ENOENT; | |
4061 | free_hash_entry(hash, entry); | |
4062 | return 0; | |
4063 | } | |
4064 | ||
4065 | return add_hash_entry(hash, ip); | |
4066 | } | |
4067 | ||
8252ecf3 | 4068 | static void ftrace_ops_update_code(struct ftrace_ops *ops, |
7485058e | 4069 | struct ftrace_ops_hash *old_hash) |
1c80c432 | 4070 | { |
8f86f837 SRRH |
4071 | struct ftrace_ops *op; |
4072 | ||
4073 | if (!ftrace_enabled) | |
4074 | return; | |
4075 | ||
4076 | if (ops->flags & FTRACE_OPS_FL_ENABLED) { | |
8252ecf3 | 4077 | ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash); |
8f86f837 SRRH |
4078 | return; |
4079 | } | |
4080 | ||
4081 | /* | |
4082 | * If this is the shared global_ops filter, then we need to | |
4083 | * check if there is another ops that shares it, is enabled. | |
4084 | * If so, we still need to run the modify code. | |
4085 | */ | |
4086 | if (ops->func_hash != &global_ops.local_hash) | |
4087 | return; | |
4088 | ||
4089 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
4090 | if (op->func_hash == &global_ops.local_hash && | |
4091 | op->flags & FTRACE_OPS_FL_ENABLED) { | |
4092 | ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash); | |
4093 | /* Only need to do this once */ | |
4094 | return; | |
4095 | } | |
4096 | } while_for_each_ftrace_op(op); | |
1c80c432 SRRH |
4097 | } |
4098 | ||
647664ea MH |
4099 | static int |
4100 | ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, | |
4101 | unsigned long ip, int remove, int reset, int enable) | |
41c52c0d | 4102 | { |
33dc9b12 | 4103 | struct ftrace_hash **orig_hash; |
7485058e | 4104 | struct ftrace_ops_hash old_hash_ops; |
3296fc4e | 4105 | struct ftrace_hash *old_hash; |
f45948e8 | 4106 | struct ftrace_hash *hash; |
33dc9b12 | 4107 | int ret; |
f45948e8 | 4108 | |
41c52c0d | 4109 | if (unlikely(ftrace_disabled)) |
33dc9b12 | 4110 | return -ENODEV; |
41c52c0d | 4111 | |
33b7f99c | 4112 | mutex_lock(&ops->func_hash->regex_lock); |
3f2367ba | 4113 | |
f45948e8 | 4114 | if (enable) |
33b7f99c | 4115 | orig_hash = &ops->func_hash->filter_hash; |
f45948e8 | 4116 | else |
33b7f99c | 4117 | orig_hash = &ops->func_hash->notrace_hash; |
33dc9b12 | 4118 | |
b972cc58 WN |
4119 | if (reset) |
4120 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); | |
4121 | else | |
4122 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
4123 | ||
3f2367ba MH |
4124 | if (!hash) { |
4125 | ret = -ENOMEM; | |
4126 | goto out_regex_unlock; | |
4127 | } | |
f45948e8 | 4128 | |
ac483c44 JO |
4129 | if (buf && !ftrace_match_records(hash, buf, len)) { |
4130 | ret = -EINVAL; | |
4131 | goto out_regex_unlock; | |
4132 | } | |
647664ea MH |
4133 | if (ip) { |
4134 | ret = ftrace_match_addr(hash, ip, remove); | |
4135 | if (ret < 0) | |
4136 | goto out_regex_unlock; | |
4137 | } | |
33dc9b12 SR |
4138 | |
4139 | mutex_lock(&ftrace_lock); | |
3296fc4e | 4140 | old_hash = *orig_hash; |
7485058e SRRH |
4141 | old_hash_ops.filter_hash = ops->func_hash->filter_hash; |
4142 | old_hash_ops.notrace_hash = ops->func_hash->notrace_hash; | |
41fb61c2 | 4143 | ret = ftrace_hash_move(ops, enable, orig_hash, hash); |
3296fc4e | 4144 | if (!ret) { |
7485058e | 4145 | ftrace_ops_update_code(ops, &old_hash_ops); |
3296fc4e SRRH |
4146 | free_ftrace_hash_rcu(old_hash); |
4147 | } | |
33dc9b12 SR |
4148 | mutex_unlock(&ftrace_lock); |
4149 | ||
ac483c44 | 4150 | out_regex_unlock: |
33b7f99c | 4151 | mutex_unlock(&ops->func_hash->regex_lock); |
33dc9b12 SR |
4152 | |
4153 | free_ftrace_hash(hash); | |
4154 | return ret; | |
41c52c0d SR |
4155 | } |
4156 | ||
647664ea MH |
4157 | static int |
4158 | ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove, | |
4159 | int reset, int enable) | |
4160 | { | |
4161 | return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable); | |
4162 | } | |
4163 | ||
4164 | /** | |
4165 | * ftrace_set_filter_ip - set a function to filter on in ftrace by address | |
4166 | * @ops - the ops to set the filter with | |
4167 | * @ip - the address to add to or remove from the filter. | |
4168 | * @remove - non zero to remove the ip from the filter | |
4169 | * @reset - non zero to reset all filters before applying this filter. | |
4170 | * | |
4171 | * Filters denote which functions should be enabled when tracing is enabled | |
4172 | * If @ip is NULL, it failes to update filter. | |
4173 | */ | |
4174 | int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, | |
4175 | int remove, int reset) | |
4176 | { | |
f04f24fb | 4177 | ftrace_ops_init(ops); |
647664ea MH |
4178 | return ftrace_set_addr(ops, ip, remove, reset, 1); |
4179 | } | |
4180 | EXPORT_SYMBOL_GPL(ftrace_set_filter_ip); | |
4181 | ||
4182 | static int | |
4183 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, | |
4184 | int reset, int enable) | |
4185 | { | |
4186 | return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable); | |
4187 | } | |
4188 | ||
77a2b37d SR |
4189 | /** |
4190 | * ftrace_set_filter - set a function to filter on in ftrace | |
936e074b SR |
4191 | * @ops - the ops to set the filter with |
4192 | * @buf - the string that holds the function filter text. | |
4193 | * @len - the length of the string. | |
4194 | * @reset - non zero to reset all filters before applying this filter. | |
4195 | * | |
4196 | * Filters denote which functions should be enabled when tracing is enabled. | |
4197 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
4198 | */ | |
ac483c44 | 4199 | int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
4200 | int len, int reset) |
4201 | { | |
f04f24fb | 4202 | ftrace_ops_init(ops); |
ac483c44 | 4203 | return ftrace_set_regex(ops, buf, len, reset, 1); |
936e074b SR |
4204 | } |
4205 | EXPORT_SYMBOL_GPL(ftrace_set_filter); | |
4206 | ||
4207 | /** | |
4208 | * ftrace_set_notrace - set a function to not trace in ftrace | |
4209 | * @ops - the ops to set the notrace filter with | |
4210 | * @buf - the string that holds the function notrace text. | |
4211 | * @len - the length of the string. | |
4212 | * @reset - non zero to reset all filters before applying this filter. | |
4213 | * | |
4214 | * Notrace Filters denote which functions should not be enabled when tracing | |
4215 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
4216 | * for tracing. | |
4217 | */ | |
ac483c44 | 4218 | int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
4219 | int len, int reset) |
4220 | { | |
f04f24fb | 4221 | ftrace_ops_init(ops); |
ac483c44 | 4222 | return ftrace_set_regex(ops, buf, len, reset, 0); |
936e074b SR |
4223 | } |
4224 | EXPORT_SYMBOL_GPL(ftrace_set_notrace); | |
4225 | /** | |
8d1b065d | 4226 | * ftrace_set_global_filter - set a function to filter on with global tracers |
77a2b37d SR |
4227 | * @buf - the string that holds the function filter text. |
4228 | * @len - the length of the string. | |
4229 | * @reset - non zero to reset all filters before applying this filter. | |
4230 | * | |
4231 | * Filters denote which functions should be enabled when tracing is enabled. | |
4232 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
4233 | */ | |
936e074b | 4234 | void ftrace_set_global_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 4235 | { |
f45948e8 | 4236 | ftrace_set_regex(&global_ops, buf, len, reset, 1); |
41c52c0d | 4237 | } |
936e074b | 4238 | EXPORT_SYMBOL_GPL(ftrace_set_global_filter); |
4eebcc81 | 4239 | |
41c52c0d | 4240 | /** |
8d1b065d | 4241 | * ftrace_set_global_notrace - set a function to not trace with global tracers |
41c52c0d SR |
4242 | * @buf - the string that holds the function notrace text. |
4243 | * @len - the length of the string. | |
4244 | * @reset - non zero to reset all filters before applying this filter. | |
4245 | * | |
4246 | * Notrace Filters denote which functions should not be enabled when tracing | |
4247 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
4248 | * for tracing. | |
4249 | */ | |
936e074b | 4250 | void ftrace_set_global_notrace(unsigned char *buf, int len, int reset) |
41c52c0d | 4251 | { |
f45948e8 | 4252 | ftrace_set_regex(&global_ops, buf, len, reset, 0); |
77a2b37d | 4253 | } |
936e074b | 4254 | EXPORT_SYMBOL_GPL(ftrace_set_global_notrace); |
77a2b37d | 4255 | |
2af15d6a SR |
4256 | /* |
4257 | * command line interface to allow users to set filters on boot up. | |
4258 | */ | |
4259 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
4260 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
4261 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
4262 | ||
f1ed7c74 SRRH |
4263 | /* Used by function selftest to not test if filter is set */ |
4264 | bool ftrace_filter_param __initdata; | |
4265 | ||
2af15d6a SR |
4266 | static int __init set_ftrace_notrace(char *str) |
4267 | { | |
f1ed7c74 | 4268 | ftrace_filter_param = true; |
75761cc1 | 4269 | strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
4270 | return 1; |
4271 | } | |
4272 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
4273 | ||
4274 | static int __init set_ftrace_filter(char *str) | |
4275 | { | |
f1ed7c74 | 4276 | ftrace_filter_param = true; |
75761cc1 | 4277 | strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
4278 | return 1; |
4279 | } | |
4280 | __setup("ftrace_filter=", set_ftrace_filter); | |
4281 | ||
369bc18f | 4282 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 4283 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
0d7d9a16 | 4284 | static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata; |
faf982a6 | 4285 | static int ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer); |
801c29fd | 4286 | |
f3bea491 SRRH |
4287 | static unsigned long save_global_trampoline; |
4288 | static unsigned long save_global_flags; | |
4289 | ||
369bc18f SA |
4290 | static int __init set_graph_function(char *str) |
4291 | { | |
06f43d66 | 4292 | strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
4293 | return 1; |
4294 | } | |
4295 | __setup("ftrace_graph_filter=", set_graph_function); | |
4296 | ||
0d7d9a16 NK |
4297 | static int __init set_graph_notrace_function(char *str) |
4298 | { | |
4299 | strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE); | |
4300 | return 1; | |
4301 | } | |
4302 | __setup("ftrace_graph_notrace=", set_graph_notrace_function); | |
4303 | ||
4304 | static void __init set_ftrace_early_graph(char *buf, int enable) | |
369bc18f SA |
4305 | { |
4306 | int ret; | |
4307 | char *func; | |
0d7d9a16 NK |
4308 | unsigned long *table = ftrace_graph_funcs; |
4309 | int *count = &ftrace_graph_count; | |
4310 | ||
4311 | if (!enable) { | |
4312 | table = ftrace_graph_notrace_funcs; | |
4313 | count = &ftrace_graph_notrace_count; | |
4314 | } | |
369bc18f SA |
4315 | |
4316 | while (buf) { | |
4317 | func = strsep(&buf, ","); | |
4318 | /* we allow only one expression at a time */ | |
0d7d9a16 | 4319 | ret = ftrace_set_func(table, count, FTRACE_GRAPH_MAX_FUNCS, func); |
369bc18f SA |
4320 | if (ret) |
4321 | printk(KERN_DEBUG "ftrace: function %s not " | |
4322 | "traceable\n", func); | |
4323 | } | |
4324 | } | |
4325 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
4326 | ||
2a85a37f SR |
4327 | void __init |
4328 | ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable) | |
2af15d6a SR |
4329 | { |
4330 | char *func; | |
4331 | ||
f04f24fb MH |
4332 | ftrace_ops_init(ops); |
4333 | ||
2af15d6a SR |
4334 | while (buf) { |
4335 | func = strsep(&buf, ","); | |
f45948e8 | 4336 | ftrace_set_regex(ops, func, strlen(func), 0, enable); |
2af15d6a SR |
4337 | } |
4338 | } | |
4339 | ||
4340 | static void __init set_ftrace_early_filters(void) | |
4341 | { | |
4342 | if (ftrace_filter_buf[0]) | |
2a85a37f | 4343 | ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1); |
2af15d6a | 4344 | if (ftrace_notrace_buf[0]) |
2a85a37f | 4345 | ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0); |
369bc18f SA |
4346 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
4347 | if (ftrace_graph_buf[0]) | |
0d7d9a16 NK |
4348 | set_ftrace_early_graph(ftrace_graph_buf, 1); |
4349 | if (ftrace_graph_notrace_buf[0]) | |
4350 | set_ftrace_early_graph(ftrace_graph_notrace_buf, 0); | |
369bc18f | 4351 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
2af15d6a SR |
4352 | } |
4353 | ||
fc13cb0c | 4354 | int ftrace_regex_release(struct inode *inode, struct file *file) |
5072c59f SR |
4355 | { |
4356 | struct seq_file *m = (struct seq_file *)file->private_data; | |
7485058e | 4357 | struct ftrace_ops_hash old_hash_ops; |
5072c59f | 4358 | struct ftrace_iterator *iter; |
33dc9b12 | 4359 | struct ftrace_hash **orig_hash; |
3296fc4e | 4360 | struct ftrace_hash *old_hash; |
689fd8b6 | 4361 | struct trace_parser *parser; |
ed926f9b | 4362 | int filter_hash; |
33dc9b12 | 4363 | int ret; |
5072c59f | 4364 | |
5072c59f SR |
4365 | if (file->f_mode & FMODE_READ) { |
4366 | iter = m->private; | |
5072c59f SR |
4367 | seq_release(inode, file); |
4368 | } else | |
4369 | iter = file->private_data; | |
4370 | ||
689fd8b6 | 4371 | parser = &iter->parser; |
4372 | if (trace_parser_loaded(parser)) { | |
4373 | parser->buffer[parser->idx] = 0; | |
1cf41dd7 | 4374 | ftrace_match_records(iter->hash, parser->buffer, parser->idx); |
5072c59f SR |
4375 | } |
4376 | ||
689fd8b6 | 4377 | trace_parser_put(parser); |
689fd8b6 | 4378 | |
33b7f99c | 4379 | mutex_lock(&iter->ops->func_hash->regex_lock); |
3f2367ba | 4380 | |
058e297d | 4381 | if (file->f_mode & FMODE_WRITE) { |
ed926f9b SR |
4382 | filter_hash = !!(iter->flags & FTRACE_ITER_FILTER); |
4383 | ||
4384 | if (filter_hash) | |
33b7f99c | 4385 | orig_hash = &iter->ops->func_hash->filter_hash; |
ed926f9b | 4386 | else |
33b7f99c | 4387 | orig_hash = &iter->ops->func_hash->notrace_hash; |
33dc9b12 | 4388 | |
058e297d | 4389 | mutex_lock(&ftrace_lock); |
3296fc4e | 4390 | old_hash = *orig_hash; |
7485058e SRRH |
4391 | old_hash_ops.filter_hash = iter->ops->func_hash->filter_hash; |
4392 | old_hash_ops.notrace_hash = iter->ops->func_hash->notrace_hash; | |
41fb61c2 SR |
4393 | ret = ftrace_hash_move(iter->ops, filter_hash, |
4394 | orig_hash, iter->hash); | |
3296fc4e | 4395 | if (!ret) { |
7485058e | 4396 | ftrace_ops_update_code(iter->ops, &old_hash_ops); |
3296fc4e SRRH |
4397 | free_ftrace_hash_rcu(old_hash); |
4398 | } | |
058e297d SR |
4399 | mutex_unlock(&ftrace_lock); |
4400 | } | |
3f2367ba | 4401 | |
33b7f99c | 4402 | mutex_unlock(&iter->ops->func_hash->regex_lock); |
33dc9b12 SR |
4403 | free_ftrace_hash(iter->hash); |
4404 | kfree(iter); | |
058e297d | 4405 | |
5072c59f SR |
4406 | return 0; |
4407 | } | |
4408 | ||
5e2336a0 | 4409 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
4410 | .open = ftrace_avail_open, |
4411 | .read = seq_read, | |
4412 | .llseek = seq_lseek, | |
3be04b47 | 4413 | .release = seq_release_private, |
5072c59f SR |
4414 | }; |
4415 | ||
647bcd03 SR |
4416 | static const struct file_operations ftrace_enabled_fops = { |
4417 | .open = ftrace_enabled_open, | |
4418 | .read = seq_read, | |
4419 | .llseek = seq_lseek, | |
4420 | .release = seq_release_private, | |
4421 | }; | |
4422 | ||
5e2336a0 | 4423 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 4424 | .open = ftrace_filter_open, |
850a80cf | 4425 | .read = seq_read, |
5072c59f | 4426 | .write = ftrace_filter_write, |
098c879e | 4427 | .llseek = tracing_lseek, |
1cf41dd7 | 4428 | .release = ftrace_regex_release, |
5072c59f SR |
4429 | }; |
4430 | ||
5e2336a0 | 4431 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 4432 | .open = ftrace_notrace_open, |
850a80cf | 4433 | .read = seq_read, |
41c52c0d | 4434 | .write = ftrace_notrace_write, |
098c879e | 4435 | .llseek = tracing_lseek, |
1cf41dd7 | 4436 | .release = ftrace_regex_release, |
41c52c0d SR |
4437 | }; |
4438 | ||
ea4e2bc4 SR |
4439 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
4440 | ||
4441 | static DEFINE_MUTEX(graph_lock); | |
4442 | ||
4443 | int ftrace_graph_count; | |
29ad23b0 | 4444 | int ftrace_graph_notrace_count; |
ea4e2bc4 | 4445 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
29ad23b0 | 4446 | unsigned long ftrace_graph_notrace_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
ea4e2bc4 | 4447 | |
faf982a6 NK |
4448 | struct ftrace_graph_data { |
4449 | unsigned long *table; | |
4450 | size_t size; | |
4451 | int *count; | |
4452 | const struct seq_operations *seq_ops; | |
4453 | }; | |
4454 | ||
ea4e2bc4 | 4455 | static void * |
85951842 | 4456 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 4457 | { |
faf982a6 NK |
4458 | struct ftrace_graph_data *fgd = m->private; |
4459 | ||
4460 | if (*pos >= *fgd->count) | |
ea4e2bc4 | 4461 | return NULL; |
faf982a6 | 4462 | return &fgd->table[*pos]; |
85951842 | 4463 | } |
ea4e2bc4 | 4464 | |
85951842 LZ |
4465 | static void * |
4466 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
4467 | { | |
4468 | (*pos)++; | |
4469 | return __g_next(m, pos); | |
ea4e2bc4 SR |
4470 | } |
4471 | ||
4472 | static void *g_start(struct seq_file *m, loff_t *pos) | |
4473 | { | |
faf982a6 NK |
4474 | struct ftrace_graph_data *fgd = m->private; |
4475 | ||
ea4e2bc4 SR |
4476 | mutex_lock(&graph_lock); |
4477 | ||
f9349a8f | 4478 | /* Nothing, tell g_show to print all functions are enabled */ |
faf982a6 | 4479 | if (!*fgd->count && !*pos) |
f9349a8f FW |
4480 | return (void *)1; |
4481 | ||
85951842 | 4482 | return __g_next(m, pos); |
ea4e2bc4 SR |
4483 | } |
4484 | ||
4485 | static void g_stop(struct seq_file *m, void *p) | |
4486 | { | |
4487 | mutex_unlock(&graph_lock); | |
4488 | } | |
4489 | ||
4490 | static int g_show(struct seq_file *m, void *v) | |
4491 | { | |
4492 | unsigned long *ptr = v; | |
ea4e2bc4 SR |
4493 | |
4494 | if (!ptr) | |
4495 | return 0; | |
4496 | ||
f9349a8f | 4497 | if (ptr == (unsigned long *)1) { |
280d1429 NK |
4498 | struct ftrace_graph_data *fgd = m->private; |
4499 | ||
4500 | if (fgd->table == ftrace_graph_funcs) | |
fa6f0cc7 | 4501 | seq_puts(m, "#### all functions enabled ####\n"); |
280d1429 | 4502 | else |
fa6f0cc7 | 4503 | seq_puts(m, "#### no functions disabled ####\n"); |
f9349a8f FW |
4504 | return 0; |
4505 | } | |
4506 | ||
b375a11a | 4507 | seq_printf(m, "%ps\n", (void *)*ptr); |
ea4e2bc4 SR |
4508 | |
4509 | return 0; | |
4510 | } | |
4511 | ||
88e9d34c | 4512 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
4513 | .start = g_start, |
4514 | .next = g_next, | |
4515 | .stop = g_stop, | |
4516 | .show = g_show, | |
4517 | }; | |
4518 | ||
4519 | static int | |
faf982a6 NK |
4520 | __ftrace_graph_open(struct inode *inode, struct file *file, |
4521 | struct ftrace_graph_data *fgd) | |
ea4e2bc4 SR |
4522 | { |
4523 | int ret = 0; | |
4524 | ||
ea4e2bc4 SR |
4525 | mutex_lock(&graph_lock); |
4526 | if ((file->f_mode & FMODE_WRITE) && | |
8650ae32 | 4527 | (file->f_flags & O_TRUNC)) { |
faf982a6 NK |
4528 | *fgd->count = 0; |
4529 | memset(fgd->table, 0, fgd->size * sizeof(*fgd->table)); | |
ea4e2bc4 | 4530 | } |
a4ec5e0c | 4531 | mutex_unlock(&graph_lock); |
ea4e2bc4 | 4532 | |
faf982a6 NK |
4533 | if (file->f_mode & FMODE_READ) { |
4534 | ret = seq_open(file, fgd->seq_ops); | |
4535 | if (!ret) { | |
4536 | struct seq_file *m = file->private_data; | |
4537 | m->private = fgd; | |
4538 | } | |
4539 | } else | |
4540 | file->private_data = fgd; | |
ea4e2bc4 SR |
4541 | |
4542 | return ret; | |
4543 | } | |
4544 | ||
faf982a6 NK |
4545 | static int |
4546 | ftrace_graph_open(struct inode *inode, struct file *file) | |
4547 | { | |
4548 | struct ftrace_graph_data *fgd; | |
4549 | ||
4550 | if (unlikely(ftrace_disabled)) | |
4551 | return -ENODEV; | |
4552 | ||
4553 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
4554 | if (fgd == NULL) | |
4555 | return -ENOMEM; | |
4556 | ||
4557 | fgd->table = ftrace_graph_funcs; | |
4558 | fgd->size = FTRACE_GRAPH_MAX_FUNCS; | |
4559 | fgd->count = &ftrace_graph_count; | |
4560 | fgd->seq_ops = &ftrace_graph_seq_ops; | |
4561 | ||
4562 | return __ftrace_graph_open(inode, file, fgd); | |
4563 | } | |
4564 | ||
29ad23b0 NK |
4565 | static int |
4566 | ftrace_graph_notrace_open(struct inode *inode, struct file *file) | |
4567 | { | |
4568 | struct ftrace_graph_data *fgd; | |
4569 | ||
4570 | if (unlikely(ftrace_disabled)) | |
4571 | return -ENODEV; | |
4572 | ||
4573 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
4574 | if (fgd == NULL) | |
4575 | return -ENOMEM; | |
4576 | ||
4577 | fgd->table = ftrace_graph_notrace_funcs; | |
4578 | fgd->size = FTRACE_GRAPH_MAX_FUNCS; | |
4579 | fgd->count = &ftrace_graph_notrace_count; | |
4580 | fgd->seq_ops = &ftrace_graph_seq_ops; | |
4581 | ||
4582 | return __ftrace_graph_open(inode, file, fgd); | |
4583 | } | |
4584 | ||
87827111 LZ |
4585 | static int |
4586 | ftrace_graph_release(struct inode *inode, struct file *file) | |
4587 | { | |
faf982a6 NK |
4588 | if (file->f_mode & FMODE_READ) { |
4589 | struct seq_file *m = file->private_data; | |
4590 | ||
4591 | kfree(m->private); | |
87827111 | 4592 | seq_release(inode, file); |
faf982a6 NK |
4593 | } else { |
4594 | kfree(file->private_data); | |
4595 | } | |
4596 | ||
87827111 LZ |
4597 | return 0; |
4598 | } | |
4599 | ||
ea4e2bc4 | 4600 | static int |
faf982a6 | 4601 | ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer) |
ea4e2bc4 | 4602 | { |
ea4e2bc4 SR |
4603 | struct dyn_ftrace *rec; |
4604 | struct ftrace_page *pg; | |
f9349a8f | 4605 | int search_len; |
c7c6b1fe | 4606 | int fail = 1; |
f9349a8f FW |
4607 | int type, not; |
4608 | char *search; | |
4609 | bool exists; | |
4610 | int i; | |
ea4e2bc4 | 4611 | |
f9349a8f | 4612 | /* decode regex */ |
3f6fe06d | 4613 | type = filter_parse_regex(buffer, strlen(buffer), &search, ¬); |
faf982a6 | 4614 | if (!not && *idx >= size) |
c7c6b1fe | 4615 | return -EBUSY; |
f9349a8f FW |
4616 | |
4617 | search_len = strlen(search); | |
4618 | ||
52baf119 | 4619 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
4620 | |
4621 | if (unlikely(ftrace_disabled)) { | |
4622 | mutex_unlock(&ftrace_lock); | |
4623 | return -ENODEV; | |
4624 | } | |
4625 | ||
265c831c SR |
4626 | do_for_each_ftrace_rec(pg, rec) { |
4627 | ||
b9df92d2 | 4628 | if (ftrace_match_record(rec, NULL, search, search_len, type)) { |
c7c6b1fe | 4629 | /* if it is in the array */ |
f9349a8f | 4630 | exists = false; |
c7c6b1fe | 4631 | for (i = 0; i < *idx; i++) { |
f9349a8f FW |
4632 | if (array[i] == rec->ip) { |
4633 | exists = true; | |
265c831c SR |
4634 | break; |
4635 | } | |
c7c6b1fe LZ |
4636 | } |
4637 | ||
4638 | if (!not) { | |
4639 | fail = 0; | |
4640 | if (!exists) { | |
4641 | array[(*idx)++] = rec->ip; | |
faf982a6 | 4642 | if (*idx >= size) |
c7c6b1fe LZ |
4643 | goto out; |
4644 | } | |
4645 | } else { | |
4646 | if (exists) { | |
4647 | array[i] = array[--(*idx)]; | |
4648 | array[*idx] = 0; | |
4649 | fail = 0; | |
4650 | } | |
4651 | } | |
ea4e2bc4 | 4652 | } |
265c831c | 4653 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 4654 | out: |
52baf119 | 4655 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 4656 | |
c7c6b1fe LZ |
4657 | if (fail) |
4658 | return -EINVAL; | |
4659 | ||
c7c6b1fe | 4660 | return 0; |
ea4e2bc4 SR |
4661 | } |
4662 | ||
4663 | static ssize_t | |
4664 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
4665 | size_t cnt, loff_t *ppos) | |
4666 | { | |
689fd8b6 | 4667 | struct trace_parser parser; |
6a10108b | 4668 | ssize_t read, ret = 0; |
faf982a6 | 4669 | struct ftrace_graph_data *fgd = file->private_data; |
ea4e2bc4 | 4670 | |
c7c6b1fe | 4671 | if (!cnt) |
ea4e2bc4 SR |
4672 | return 0; |
4673 | ||
6a10108b NK |
4674 | if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) |
4675 | return -ENOMEM; | |
ea4e2bc4 | 4676 | |
689fd8b6 | 4677 | read = trace_get_user(&parser, ubuf, cnt, ppos); |
ea4e2bc4 | 4678 | |
4ba7978e | 4679 | if (read >= 0 && trace_parser_loaded((&parser))) { |
689fd8b6 | 4680 | parser.buffer[parser.idx] = 0; |
4681 | ||
6a10108b NK |
4682 | mutex_lock(&graph_lock); |
4683 | ||
689fd8b6 | 4684 | /* we allow only one expression at a time */ |
faf982a6 NK |
4685 | ret = ftrace_set_func(fgd->table, fgd->count, fgd->size, |
4686 | parser.buffer); | |
6a10108b NK |
4687 | |
4688 | mutex_unlock(&graph_lock); | |
ea4e2bc4 | 4689 | } |
ea4e2bc4 | 4690 | |
6a10108b NK |
4691 | if (!ret) |
4692 | ret = read; | |
1eb90f13 | 4693 | |
689fd8b6 | 4694 | trace_parser_put(&parser); |
ea4e2bc4 SR |
4695 | |
4696 | return ret; | |
4697 | } | |
4698 | ||
4699 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
4700 | .open = ftrace_graph_open, |
4701 | .read = seq_read, | |
4702 | .write = ftrace_graph_write, | |
098c879e | 4703 | .llseek = tracing_lseek, |
87827111 | 4704 | .release = ftrace_graph_release, |
ea4e2bc4 | 4705 | }; |
29ad23b0 NK |
4706 | |
4707 | static const struct file_operations ftrace_graph_notrace_fops = { | |
4708 | .open = ftrace_graph_notrace_open, | |
4709 | .read = seq_read, | |
4710 | .write = ftrace_graph_write, | |
098c879e | 4711 | .llseek = tracing_lseek, |
29ad23b0 NK |
4712 | .release = ftrace_graph_release, |
4713 | }; | |
ea4e2bc4 SR |
4714 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
4715 | ||
591dffda SRRH |
4716 | void ftrace_create_filter_files(struct ftrace_ops *ops, |
4717 | struct dentry *parent) | |
4718 | { | |
4719 | ||
4720 | trace_create_file("set_ftrace_filter", 0644, parent, | |
4721 | ops, &ftrace_filter_fops); | |
4722 | ||
4723 | trace_create_file("set_ftrace_notrace", 0644, parent, | |
4724 | ops, &ftrace_notrace_fops); | |
4725 | } | |
4726 | ||
4727 | /* | |
4728 | * The name "destroy_filter_files" is really a misnomer. Although | |
4729 | * in the future, it may actualy delete the files, but this is | |
4730 | * really intended to make sure the ops passed in are disabled | |
4731 | * and that when this function returns, the caller is free to | |
4732 | * free the ops. | |
4733 | * | |
4734 | * The "destroy" name is only to match the "create" name that this | |
4735 | * should be paired with. | |
4736 | */ | |
4737 | void ftrace_destroy_filter_files(struct ftrace_ops *ops) | |
4738 | { | |
4739 | mutex_lock(&ftrace_lock); | |
4740 | if (ops->flags & FTRACE_OPS_FL_ENABLED) | |
4741 | ftrace_shutdown(ops, 0); | |
4742 | ops->flags |= FTRACE_OPS_FL_DELETED; | |
4743 | mutex_unlock(&ftrace_lock); | |
4744 | } | |
4745 | ||
8434dc93 | 4746 | static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer) |
5072c59f | 4747 | { |
5072c59f | 4748 | |
5452af66 FW |
4749 | trace_create_file("available_filter_functions", 0444, |
4750 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 4751 | |
647bcd03 SR |
4752 | trace_create_file("enabled_functions", 0444, |
4753 | d_tracer, NULL, &ftrace_enabled_fops); | |
4754 | ||
591dffda | 4755 | ftrace_create_filter_files(&global_ops, d_tracer); |
ad90c0e3 | 4756 | |
ea4e2bc4 | 4757 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5452af66 | 4758 | trace_create_file("set_graph_function", 0444, d_tracer, |
ea4e2bc4 SR |
4759 | NULL, |
4760 | &ftrace_graph_fops); | |
29ad23b0 NK |
4761 | trace_create_file("set_graph_notrace", 0444, d_tracer, |
4762 | NULL, | |
4763 | &ftrace_graph_notrace_fops); | |
ea4e2bc4 SR |
4764 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
4765 | ||
5072c59f SR |
4766 | return 0; |
4767 | } | |
4768 | ||
9fd49328 | 4769 | static int ftrace_cmp_ips(const void *a, const void *b) |
68950619 | 4770 | { |
9fd49328 SR |
4771 | const unsigned long *ipa = a; |
4772 | const unsigned long *ipb = b; | |
68950619 | 4773 | |
9fd49328 SR |
4774 | if (*ipa > *ipb) |
4775 | return 1; | |
4776 | if (*ipa < *ipb) | |
4777 | return -1; | |
4778 | return 0; | |
4779 | } | |
4780 | ||
4781 | static void ftrace_swap_ips(void *a, void *b, int size) | |
4782 | { | |
4783 | unsigned long *ipa = a; | |
4784 | unsigned long *ipb = b; | |
4785 | unsigned long t; | |
4786 | ||
4787 | t = *ipa; | |
4788 | *ipa = *ipb; | |
4789 | *ipb = t; | |
68950619 SR |
4790 | } |
4791 | ||
5cb084bb | 4792 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 4793 | unsigned long *start, |
68bf21aa SR |
4794 | unsigned long *end) |
4795 | { | |
706c81f8 | 4796 | struct ftrace_page *start_pg; |
a7900875 | 4797 | struct ftrace_page *pg; |
706c81f8 | 4798 | struct dyn_ftrace *rec; |
a7900875 | 4799 | unsigned long count; |
68bf21aa SR |
4800 | unsigned long *p; |
4801 | unsigned long addr; | |
4376cac6 | 4802 | unsigned long flags = 0; /* Shut up gcc */ |
a7900875 SR |
4803 | int ret = -ENOMEM; |
4804 | ||
4805 | count = end - start; | |
4806 | ||
4807 | if (!count) | |
4808 | return 0; | |
4809 | ||
9fd49328 SR |
4810 | sort(start, count, sizeof(*start), |
4811 | ftrace_cmp_ips, ftrace_swap_ips); | |
4812 | ||
706c81f8 SR |
4813 | start_pg = ftrace_allocate_pages(count); |
4814 | if (!start_pg) | |
a7900875 | 4815 | return -ENOMEM; |
68bf21aa | 4816 | |
e6ea44e9 | 4817 | mutex_lock(&ftrace_lock); |
a7900875 | 4818 | |
32082309 SR |
4819 | /* |
4820 | * Core and each module needs their own pages, as | |
4821 | * modules will free them when they are removed. | |
4822 | * Force a new page to be allocated for modules. | |
4823 | */ | |
a7900875 SR |
4824 | if (!mod) { |
4825 | WARN_ON(ftrace_pages || ftrace_pages_start); | |
4826 | /* First initialization */ | |
706c81f8 | 4827 | ftrace_pages = ftrace_pages_start = start_pg; |
a7900875 | 4828 | } else { |
32082309 | 4829 | if (!ftrace_pages) |
a7900875 | 4830 | goto out; |
32082309 | 4831 | |
a7900875 SR |
4832 | if (WARN_ON(ftrace_pages->next)) { |
4833 | /* Hmm, we have free pages? */ | |
4834 | while (ftrace_pages->next) | |
4835 | ftrace_pages = ftrace_pages->next; | |
32082309 | 4836 | } |
a7900875 | 4837 | |
706c81f8 | 4838 | ftrace_pages->next = start_pg; |
32082309 SR |
4839 | } |
4840 | ||
68bf21aa | 4841 | p = start; |
706c81f8 | 4842 | pg = start_pg; |
68bf21aa SR |
4843 | while (p < end) { |
4844 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
4845 | /* |
4846 | * Some architecture linkers will pad between | |
4847 | * the different mcount_loc sections of different | |
4848 | * object files to satisfy alignments. | |
4849 | * Skip any NULL pointers. | |
4850 | */ | |
4851 | if (!addr) | |
4852 | continue; | |
706c81f8 SR |
4853 | |
4854 | if (pg->index == pg->size) { | |
4855 | /* We should have allocated enough */ | |
4856 | if (WARN_ON(!pg->next)) | |
4857 | break; | |
4858 | pg = pg->next; | |
4859 | } | |
4860 | ||
4861 | rec = &pg->records[pg->index++]; | |
4862 | rec->ip = addr; | |
68bf21aa SR |
4863 | } |
4864 | ||
706c81f8 SR |
4865 | /* We should have used all pages */ |
4866 | WARN_ON(pg->next); | |
4867 | ||
4868 | /* Assign the last page to ftrace_pages */ | |
4869 | ftrace_pages = pg; | |
4870 | ||
a4f18ed1 | 4871 | /* |
4376cac6 SR |
4872 | * We only need to disable interrupts on start up |
4873 | * because we are modifying code that an interrupt | |
4874 | * may execute, and the modification is not atomic. | |
4875 | * But for modules, nothing runs the code we modify | |
4876 | * until we are finished with it, and there's no | |
4877 | * reason to cause large interrupt latencies while we do it. | |
a4f18ed1 | 4878 | */ |
4376cac6 SR |
4879 | if (!mod) |
4880 | local_irq_save(flags); | |
1dc43cf0 | 4881 | ftrace_update_code(mod, start_pg); |
4376cac6 SR |
4882 | if (!mod) |
4883 | local_irq_restore(flags); | |
a7900875 SR |
4884 | ret = 0; |
4885 | out: | |
e6ea44e9 | 4886 | mutex_unlock(&ftrace_lock); |
68bf21aa | 4887 | |
a7900875 | 4888 | return ret; |
68bf21aa SR |
4889 | } |
4890 | ||
93eb677d | 4891 | #ifdef CONFIG_MODULES |
32082309 SR |
4892 | |
4893 | #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next) | |
4894 | ||
e7247a15 | 4895 | void ftrace_release_mod(struct module *mod) |
93eb677d SR |
4896 | { |
4897 | struct dyn_ftrace *rec; | |
32082309 | 4898 | struct ftrace_page **last_pg; |
93eb677d | 4899 | struct ftrace_page *pg; |
a7900875 | 4900 | int order; |
93eb677d | 4901 | |
45a4a237 SR |
4902 | mutex_lock(&ftrace_lock); |
4903 | ||
e7247a15 | 4904 | if (ftrace_disabled) |
45a4a237 | 4905 | goto out_unlock; |
93eb677d | 4906 | |
32082309 SR |
4907 | /* |
4908 | * Each module has its own ftrace_pages, remove | |
4909 | * them from the list. | |
4910 | */ | |
4911 | last_pg = &ftrace_pages_start; | |
4912 | for (pg = ftrace_pages_start; pg; pg = *last_pg) { | |
4913 | rec = &pg->records[0]; | |
e7247a15 | 4914 | if (within_module_core(rec->ip, mod)) { |
93eb677d | 4915 | /* |
32082309 SR |
4916 | * As core pages are first, the first |
4917 | * page should never be a module page. | |
93eb677d | 4918 | */ |
32082309 SR |
4919 | if (WARN_ON(pg == ftrace_pages_start)) |
4920 | goto out_unlock; | |
4921 | ||
4922 | /* Check if we are deleting the last page */ | |
4923 | if (pg == ftrace_pages) | |
4924 | ftrace_pages = next_to_ftrace_page(last_pg); | |
4925 | ||
4926 | *last_pg = pg->next; | |
a7900875 SR |
4927 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
4928 | free_pages((unsigned long)pg->records, order); | |
4929 | kfree(pg); | |
32082309 SR |
4930 | } else |
4931 | last_pg = &pg->next; | |
4932 | } | |
45a4a237 | 4933 | out_unlock: |
93eb677d SR |
4934 | mutex_unlock(&ftrace_lock); |
4935 | } | |
4936 | ||
4937 | static void ftrace_init_module(struct module *mod, | |
4938 | unsigned long *start, unsigned long *end) | |
90d595fe | 4939 | { |
00fd61ae | 4940 | if (ftrace_disabled || start == end) |
fed1939c | 4941 | return; |
5cb084bb | 4942 | ftrace_process_locs(mod, start, end); |
90d595fe SR |
4943 | } |
4944 | ||
a949ae56 | 4945 | void ftrace_module_init(struct module *mod) |
93eb677d | 4946 | { |
a949ae56 SRRH |
4947 | ftrace_init_module(mod, mod->ftrace_callsites, |
4948 | mod->ftrace_callsites + | |
4949 | mod->num_ftrace_callsites); | |
8c189ea6 SRRH |
4950 | } |
4951 | ||
4952 | static int ftrace_module_notify_exit(struct notifier_block *self, | |
4953 | unsigned long val, void *data) | |
4954 | { | |
4955 | struct module *mod = data; | |
4956 | ||
4957 | if (val == MODULE_STATE_GOING) | |
e7247a15 | 4958 | ftrace_release_mod(mod); |
93eb677d SR |
4959 | |
4960 | return 0; | |
4961 | } | |
4962 | #else | |
8c189ea6 SRRH |
4963 | static int ftrace_module_notify_exit(struct notifier_block *self, |
4964 | unsigned long val, void *data) | |
93eb677d SR |
4965 | { |
4966 | return 0; | |
4967 | } | |
4968 | #endif /* CONFIG_MODULES */ | |
4969 | ||
8c189ea6 SRRH |
4970 | struct notifier_block ftrace_module_exit_nb = { |
4971 | .notifier_call = ftrace_module_notify_exit, | |
4972 | .priority = INT_MIN, /* Run after anything that can remove kprobes */ | |
4973 | }; | |
4974 | ||
68bf21aa SR |
4975 | void __init ftrace_init(void) |
4976 | { | |
1dc43cf0 JS |
4977 | extern unsigned long __start_mcount_loc[]; |
4978 | extern unsigned long __stop_mcount_loc[]; | |
3a36cb11 | 4979 | unsigned long count, flags; |
68bf21aa SR |
4980 | int ret; |
4981 | ||
68bf21aa | 4982 | local_irq_save(flags); |
3a36cb11 | 4983 | ret = ftrace_dyn_arch_init(); |
68bf21aa | 4984 | local_irq_restore(flags); |
af64a7cb | 4985 | if (ret) |
68bf21aa SR |
4986 | goto failed; |
4987 | ||
4988 | count = __stop_mcount_loc - __start_mcount_loc; | |
c867ccd8 JS |
4989 | if (!count) { |
4990 | pr_info("ftrace: No functions to be traced?\n"); | |
68bf21aa | 4991 | goto failed; |
c867ccd8 JS |
4992 | } |
4993 | ||
4994 | pr_info("ftrace: allocating %ld entries in %ld pages\n", | |
4995 | count, count / ENTRIES_PER_PAGE + 1); | |
68bf21aa SR |
4996 | |
4997 | last_ftrace_enabled = ftrace_enabled = 1; | |
4998 | ||
5cb084bb | 4999 | ret = ftrace_process_locs(NULL, |
31e88909 | 5000 | __start_mcount_loc, |
68bf21aa SR |
5001 | __stop_mcount_loc); |
5002 | ||
8c189ea6 | 5003 | ret = register_module_notifier(&ftrace_module_exit_nb); |
24ed0c4b | 5004 | if (ret) |
8c189ea6 | 5005 | pr_warning("Failed to register trace ftrace module exit notifier\n"); |
93eb677d | 5006 | |
2af15d6a SR |
5007 | set_ftrace_early_filters(); |
5008 | ||
68bf21aa SR |
5009 | return; |
5010 | failed: | |
5011 | ftrace_disabled = 1; | |
5012 | } | |
68bf21aa | 5013 | |
f3bea491 SRRH |
5014 | /* Do nothing if arch does not support this */ |
5015 | void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops) | |
5016 | { | |
5017 | } | |
5018 | ||
5019 | static void ftrace_update_trampoline(struct ftrace_ops *ops) | |
5020 | { | |
12cce594 SRRH |
5021 | |
5022 | /* | |
5023 | * Currently there's no safe way to free a trampoline when the kernel | |
5024 | * is configured with PREEMPT. That is because a task could be preempted | |
5025 | * when it jumped to the trampoline, it may be preempted for a long time | |
5026 | * depending on the system load, and currently there's no way to know | |
5027 | * when it will be off the trampoline. If the trampoline is freed | |
5028 | * too early, when the task runs again, it will be executing on freed | |
5029 | * memory and crash. | |
5030 | */ | |
5031 | #ifdef CONFIG_PREEMPT | |
f3bea491 SRRH |
5032 | /* Currently, only non dynamic ops can have a trampoline */ |
5033 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC) | |
5034 | return; | |
12cce594 | 5035 | #endif |
f3bea491 SRRH |
5036 | |
5037 | arch_ftrace_update_trampoline(ops); | |
5038 | } | |
5039 | ||
3d083395 | 5040 | #else |
0b6e4d56 | 5041 | |
2b499381 | 5042 | static struct ftrace_ops global_ops = { |
bd69c30b | 5043 | .func = ftrace_stub, |
e3eea140 SRRH |
5044 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | |
5045 | FTRACE_OPS_FL_INITIALIZED | | |
5046 | FTRACE_OPS_FL_PID, | |
bd69c30b SR |
5047 | }; |
5048 | ||
0b6e4d56 FW |
5049 | static int __init ftrace_nodyn_init(void) |
5050 | { | |
5051 | ftrace_enabled = 1; | |
5052 | return 0; | |
5053 | } | |
6f415672 | 5054 | core_initcall(ftrace_nodyn_init); |
0b6e4d56 | 5055 | |
8434dc93 | 5056 | static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; } |
df4fc315 | 5057 | static inline void ftrace_startup_enable(int command) { } |
e1effa01 | 5058 | static inline void ftrace_startup_all(int command) { } |
5a45cfe1 | 5059 | /* Keep as macros so we do not need to define the commands */ |
8a56d776 SRRH |
5060 | # define ftrace_startup(ops, command) \ |
5061 | ({ \ | |
5062 | int ___ret = __register_ftrace_function(ops); \ | |
5063 | if (!___ret) \ | |
5064 | (ops)->flags |= FTRACE_OPS_FL_ENABLED; \ | |
5065 | ___ret; \ | |
3b6cfdb1 | 5066 | }) |
1fcc1553 SRRH |
5067 | # define ftrace_shutdown(ops, command) \ |
5068 | ({ \ | |
5069 | int ___ret = __unregister_ftrace_function(ops); \ | |
5070 | if (!___ret) \ | |
5071 | (ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \ | |
5072 | ___ret; \ | |
5073 | }) | |
8a56d776 | 5074 | |
c7aafc54 IM |
5075 | # define ftrace_startup_sysctl() do { } while (0) |
5076 | # define ftrace_shutdown_sysctl() do { } while (0) | |
b848914c SR |
5077 | |
5078 | static inline int | |
195a8afc | 5079 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
b848914c SR |
5080 | { |
5081 | return 1; | |
5082 | } | |
5083 | ||
f3bea491 SRRH |
5084 | static void ftrace_update_trampoline(struct ftrace_ops *ops) |
5085 | { | |
5086 | } | |
5087 | ||
3d083395 SR |
5088 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
5089 | ||
4104d326 SRRH |
5090 | __init void ftrace_init_global_array_ops(struct trace_array *tr) |
5091 | { | |
5092 | tr->ops = &global_ops; | |
5093 | tr->ops->private = tr; | |
5094 | } | |
5095 | ||
5096 | void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func) | |
5097 | { | |
5098 | /* If we filter on pids, update to use the pid function */ | |
5099 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL) { | |
5100 | if (WARN_ON(tr->ops->func != ftrace_stub)) | |
5101 | printk("ftrace ops had %pS for function\n", | |
5102 | tr->ops->func); | |
4104d326 SRRH |
5103 | } |
5104 | tr->ops->func = func; | |
5105 | tr->ops->private = tr; | |
5106 | } | |
5107 | ||
5108 | void ftrace_reset_array_ops(struct trace_array *tr) | |
5109 | { | |
5110 | tr->ops->func = ftrace_stub; | |
5111 | } | |
5112 | ||
e248491a | 5113 | static void |
2f5f6ad9 | 5114 | ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 5115 | struct ftrace_ops *op, struct pt_regs *regs) |
e248491a | 5116 | { |
e248491a JO |
5117 | if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT))) |
5118 | return; | |
5119 | ||
5120 | /* | |
5121 | * Some of the ops may be dynamically allocated, | |
5122 | * they must be freed after a synchronize_sched(). | |
5123 | */ | |
5124 | preempt_disable_notrace(); | |
5125 | trace_recursion_set(TRACE_CONTROL_BIT); | |
b5aa3a47 SRRH |
5126 | |
5127 | /* | |
5128 | * Control funcs (perf) uses RCU. Only trace if | |
5129 | * RCU is currently active. | |
5130 | */ | |
5131 | if (!rcu_is_watching()) | |
5132 | goto out; | |
5133 | ||
0a016409 | 5134 | do_for_each_ftrace_op(op, ftrace_control_list) { |
395b97a3 SRRH |
5135 | if (!(op->flags & FTRACE_OPS_FL_STUB) && |
5136 | !ftrace_function_local_disabled(op) && | |
195a8afc | 5137 | ftrace_ops_test(op, ip, regs)) |
a1e2e31d | 5138 | op->func(ip, parent_ip, op, regs); |
0a016409 | 5139 | } while_for_each_ftrace_op(op); |
b5aa3a47 | 5140 | out: |
e248491a JO |
5141 | trace_recursion_clear(TRACE_CONTROL_BIT); |
5142 | preempt_enable_notrace(); | |
5143 | } | |
5144 | ||
5145 | static struct ftrace_ops control_ops = { | |
f04f24fb MH |
5146 | .func = ftrace_ops_control_func, |
5147 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, | |
33b7f99c | 5148 | INIT_OPS_HASH(control_ops) |
e248491a JO |
5149 | }; |
5150 | ||
2f5f6ad9 SR |
5151 | static inline void |
5152 | __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 5153 | struct ftrace_ops *ignored, struct pt_regs *regs) |
b848914c | 5154 | { |
cdbe61bf | 5155 | struct ftrace_ops *op; |
edc15caf | 5156 | int bit; |
b848914c | 5157 | |
edc15caf SR |
5158 | bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX); |
5159 | if (bit < 0) | |
5160 | return; | |
b1cff0ad | 5161 | |
cdbe61bf SR |
5162 | /* |
5163 | * Some of the ops may be dynamically allocated, | |
5164 | * they must be freed after a synchronize_sched(). | |
5165 | */ | |
5166 | preempt_disable_notrace(); | |
0a016409 | 5167 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
4104d326 | 5168 | if (ftrace_ops_test(op, ip, regs)) { |
1d48d596 SRRH |
5169 | if (FTRACE_WARN_ON(!op->func)) { |
5170 | pr_warn("op=%p %pS\n", op, op); | |
4104d326 SRRH |
5171 | goto out; |
5172 | } | |
a1e2e31d | 5173 | op->func(ip, parent_ip, op, regs); |
4104d326 | 5174 | } |
0a016409 | 5175 | } while_for_each_ftrace_op(op); |
4104d326 | 5176 | out: |
cdbe61bf | 5177 | preempt_enable_notrace(); |
edc15caf | 5178 | trace_clear_recursion(bit); |
b848914c SR |
5179 | } |
5180 | ||
2f5f6ad9 SR |
5181 | /* |
5182 | * Some archs only support passing ip and parent_ip. Even though | |
5183 | * the list function ignores the op parameter, we do not want any | |
5184 | * C side effects, where a function is called without the caller | |
5185 | * sending a third parameter. | |
a1e2e31d SR |
5186 | * Archs are to support both the regs and ftrace_ops at the same time. |
5187 | * If they support ftrace_ops, it is assumed they support regs. | |
5188 | * If call backs want to use regs, they must either check for regs | |
06aeaaea MH |
5189 | * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS. |
5190 | * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved. | |
a1e2e31d SR |
5191 | * An architecture can pass partial regs with ftrace_ops and still |
5192 | * set the ARCH_SUPPORT_FTARCE_OPS. | |
2f5f6ad9 SR |
5193 | */ |
5194 | #if ARCH_SUPPORTS_FTRACE_OPS | |
5195 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 5196 | struct ftrace_ops *op, struct pt_regs *regs) |
2f5f6ad9 | 5197 | { |
a1e2e31d | 5198 | __ftrace_ops_list_func(ip, parent_ip, NULL, regs); |
2f5f6ad9 SR |
5199 | } |
5200 | #else | |
5201 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip) | |
5202 | { | |
a1e2e31d | 5203 | __ftrace_ops_list_func(ip, parent_ip, NULL, NULL); |
2f5f6ad9 SR |
5204 | } |
5205 | #endif | |
5206 | ||
f1ff6348 SRRH |
5207 | /* |
5208 | * If there's only one function registered but it does not support | |
5209 | * recursion, this function will be called by the mcount trampoline. | |
5210 | * This function will handle recursion protection. | |
5211 | */ | |
5212 | static void ftrace_ops_recurs_func(unsigned long ip, unsigned long parent_ip, | |
5213 | struct ftrace_ops *op, struct pt_regs *regs) | |
5214 | { | |
5215 | int bit; | |
5216 | ||
5217 | bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX); | |
5218 | if (bit < 0) | |
5219 | return; | |
5220 | ||
5221 | op->func(ip, parent_ip, op, regs); | |
5222 | ||
5223 | trace_clear_recursion(bit); | |
5224 | } | |
5225 | ||
87354059 SRRH |
5226 | /** |
5227 | * ftrace_ops_get_func - get the function a trampoline should call | |
5228 | * @ops: the ops to get the function for | |
5229 | * | |
5230 | * Normally the mcount trampoline will call the ops->func, but there | |
5231 | * are times that it should not. For example, if the ops does not | |
5232 | * have its own recursion protection, then it should call the | |
5233 | * ftrace_ops_recurs_func() instead. | |
5234 | * | |
5235 | * Returns the function that the trampoline should call for @ops. | |
5236 | */ | |
5237 | ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops) | |
5238 | { | |
87354059 SRRH |
5239 | /* |
5240 | * If the func handles its own recursion, call it directly. | |
5241 | * Otherwise call the recursion protected function that | |
5242 | * will call the ftrace ops function. | |
5243 | */ | |
5244 | if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE)) | |
5245 | return ftrace_ops_recurs_func; | |
5246 | ||
5247 | return ops->func; | |
5248 | } | |
5249 | ||
e32d8956 | 5250 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
5251 | { |
5252 | struct task_struct *p; | |
e32d8956 | 5253 | int cpu; |
978f3a45 | 5254 | |
e32d8956 SR |
5255 | get_online_cpus(); |
5256 | for_each_online_cpu(cpu) { | |
5257 | p = idle_task(cpu); | |
978f3a45 | 5258 | clear_tsk_trace_trace(p); |
e32d8956 SR |
5259 | } |
5260 | put_online_cpus(); | |
5261 | } | |
978f3a45 | 5262 | |
e32d8956 SR |
5263 | static void set_ftrace_swapper(void) |
5264 | { | |
5265 | struct task_struct *p; | |
5266 | int cpu; | |
5267 | ||
5268 | get_online_cpus(); | |
5269 | for_each_online_cpu(cpu) { | |
5270 | p = idle_task(cpu); | |
5271 | set_tsk_trace_trace(p); | |
5272 | } | |
5273 | put_online_cpus(); | |
978f3a45 SR |
5274 | } |
5275 | ||
e32d8956 SR |
5276 | static void clear_ftrace_pid(struct pid *pid) |
5277 | { | |
5278 | struct task_struct *p; | |
5279 | ||
229c4ef8 | 5280 | rcu_read_lock(); |
e32d8956 SR |
5281 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
5282 | clear_tsk_trace_trace(p); | |
5283 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
5284 | rcu_read_unlock(); |
5285 | ||
e32d8956 SR |
5286 | put_pid(pid); |
5287 | } | |
5288 | ||
5289 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
5290 | { |
5291 | struct task_struct *p; | |
5292 | ||
229c4ef8 | 5293 | rcu_read_lock(); |
978f3a45 SR |
5294 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
5295 | set_tsk_trace_trace(p); | |
5296 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 5297 | rcu_read_unlock(); |
978f3a45 SR |
5298 | } |
5299 | ||
756d17ee | 5300 | static void clear_ftrace_pid_task(struct pid *pid) |
e32d8956 | 5301 | { |
756d17ee | 5302 | if (pid == ftrace_swapper_pid) |
e32d8956 SR |
5303 | clear_ftrace_swapper(); |
5304 | else | |
756d17ee | 5305 | clear_ftrace_pid(pid); |
e32d8956 SR |
5306 | } |
5307 | ||
5308 | static void set_ftrace_pid_task(struct pid *pid) | |
5309 | { | |
5310 | if (pid == ftrace_swapper_pid) | |
5311 | set_ftrace_swapper(); | |
5312 | else | |
5313 | set_ftrace_pid(pid); | |
5314 | } | |
5315 | ||
756d17ee | 5316 | static int ftrace_pid_add(int p) |
df4fc315 | 5317 | { |
978f3a45 | 5318 | struct pid *pid; |
756d17ee | 5319 | struct ftrace_pid *fpid; |
5320 | int ret = -EINVAL; | |
df4fc315 | 5321 | |
756d17ee | 5322 | mutex_lock(&ftrace_lock); |
df4fc315 | 5323 | |
756d17ee | 5324 | if (!p) |
5325 | pid = ftrace_swapper_pid; | |
5326 | else | |
5327 | pid = find_get_pid(p); | |
df4fc315 | 5328 | |
756d17ee | 5329 | if (!pid) |
5330 | goto out; | |
df4fc315 | 5331 | |
756d17ee | 5332 | ret = 0; |
df4fc315 | 5333 | |
756d17ee | 5334 | list_for_each_entry(fpid, &ftrace_pids, list) |
5335 | if (fpid->pid == pid) | |
5336 | goto out_put; | |
978f3a45 | 5337 | |
756d17ee | 5338 | ret = -ENOMEM; |
df4fc315 | 5339 | |
756d17ee | 5340 | fpid = kmalloc(sizeof(*fpid), GFP_KERNEL); |
5341 | if (!fpid) | |
5342 | goto out_put; | |
df4fc315 | 5343 | |
756d17ee | 5344 | list_add(&fpid->list, &ftrace_pids); |
5345 | fpid->pid = pid; | |
0ef8cde5 | 5346 | |
756d17ee | 5347 | set_ftrace_pid_task(pid); |
978f3a45 | 5348 | |
756d17ee | 5349 | ftrace_update_pid_func(); |
e1effa01 SRRH |
5350 | |
5351 | ftrace_startup_all(0); | |
756d17ee | 5352 | |
5353 | mutex_unlock(&ftrace_lock); | |
5354 | return 0; | |
5355 | ||
5356 | out_put: | |
5357 | if (pid != ftrace_swapper_pid) | |
5358 | put_pid(pid); | |
978f3a45 | 5359 | |
756d17ee | 5360 | out: |
5361 | mutex_unlock(&ftrace_lock); | |
5362 | return ret; | |
5363 | } | |
5364 | ||
5365 | static void ftrace_pid_reset(void) | |
5366 | { | |
5367 | struct ftrace_pid *fpid, *safe; | |
978f3a45 | 5368 | |
756d17ee | 5369 | mutex_lock(&ftrace_lock); |
5370 | list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) { | |
5371 | struct pid *pid = fpid->pid; | |
5372 | ||
5373 | clear_ftrace_pid_task(pid); | |
5374 | ||
5375 | list_del(&fpid->list); | |
5376 | kfree(fpid); | |
df4fc315 SR |
5377 | } |
5378 | ||
df4fc315 | 5379 | ftrace_update_pid_func(); |
e1effa01 | 5380 | ftrace_startup_all(0); |
df4fc315 | 5381 | |
e6ea44e9 | 5382 | mutex_unlock(&ftrace_lock); |
756d17ee | 5383 | } |
df4fc315 | 5384 | |
756d17ee | 5385 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
5386 | { | |
5387 | mutex_lock(&ftrace_lock); | |
5388 | ||
e3eea140 | 5389 | if (!ftrace_pids_enabled() && (!*pos)) |
756d17ee | 5390 | return (void *) 1; |
5391 | ||
5392 | return seq_list_start(&ftrace_pids, *pos); | |
5393 | } | |
5394 | ||
5395 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
5396 | { | |
5397 | if (v == (void *)1) | |
5398 | return NULL; | |
5399 | ||
5400 | return seq_list_next(v, &ftrace_pids, pos); | |
5401 | } | |
5402 | ||
5403 | static void fpid_stop(struct seq_file *m, void *p) | |
5404 | { | |
5405 | mutex_unlock(&ftrace_lock); | |
5406 | } | |
5407 | ||
5408 | static int fpid_show(struct seq_file *m, void *v) | |
5409 | { | |
5410 | const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list); | |
5411 | ||
5412 | if (v == (void *)1) { | |
fa6f0cc7 | 5413 | seq_puts(m, "no pid\n"); |
756d17ee | 5414 | return 0; |
5415 | } | |
5416 | ||
5417 | if (fpid->pid == ftrace_swapper_pid) | |
fa6f0cc7 | 5418 | seq_puts(m, "swapper tasks\n"); |
756d17ee | 5419 | else |
5420 | seq_printf(m, "%u\n", pid_vnr(fpid->pid)); | |
5421 | ||
5422 | return 0; | |
5423 | } | |
5424 | ||
5425 | static const struct seq_operations ftrace_pid_sops = { | |
5426 | .start = fpid_start, | |
5427 | .next = fpid_next, | |
5428 | .stop = fpid_stop, | |
5429 | .show = fpid_show, | |
5430 | }; | |
5431 | ||
5432 | static int | |
5433 | ftrace_pid_open(struct inode *inode, struct file *file) | |
5434 | { | |
5435 | int ret = 0; | |
5436 | ||
5437 | if ((file->f_mode & FMODE_WRITE) && | |
5438 | (file->f_flags & O_TRUNC)) | |
5439 | ftrace_pid_reset(); | |
5440 | ||
5441 | if (file->f_mode & FMODE_READ) | |
5442 | ret = seq_open(file, &ftrace_pid_sops); | |
5443 | ||
5444 | return ret; | |
5445 | } | |
5446 | ||
df4fc315 SR |
5447 | static ssize_t |
5448 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
5449 | size_t cnt, loff_t *ppos) | |
5450 | { | |
457dc928 | 5451 | char buf[64], *tmp; |
df4fc315 SR |
5452 | long val; |
5453 | int ret; | |
5454 | ||
5455 | if (cnt >= sizeof(buf)) | |
5456 | return -EINVAL; | |
5457 | ||
5458 | if (copy_from_user(&buf, ubuf, cnt)) | |
5459 | return -EFAULT; | |
5460 | ||
5461 | buf[cnt] = 0; | |
5462 | ||
756d17ee | 5463 | /* |
5464 | * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid" | |
5465 | * to clean the filter quietly. | |
5466 | */ | |
457dc928 IM |
5467 | tmp = strstrip(buf); |
5468 | if (strlen(tmp) == 0) | |
756d17ee | 5469 | return 1; |
5470 | ||
bcd83ea6 | 5471 | ret = kstrtol(tmp, 10, &val); |
df4fc315 SR |
5472 | if (ret < 0) |
5473 | return ret; | |
5474 | ||
756d17ee | 5475 | ret = ftrace_pid_add(val); |
df4fc315 | 5476 | |
756d17ee | 5477 | return ret ? ret : cnt; |
5478 | } | |
df4fc315 | 5479 | |
756d17ee | 5480 | static int |
5481 | ftrace_pid_release(struct inode *inode, struct file *file) | |
5482 | { | |
5483 | if (file->f_mode & FMODE_READ) | |
5484 | seq_release(inode, file); | |
df4fc315 | 5485 | |
756d17ee | 5486 | return 0; |
df4fc315 SR |
5487 | } |
5488 | ||
5e2336a0 | 5489 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 5490 | .open = ftrace_pid_open, |
5491 | .write = ftrace_pid_write, | |
5492 | .read = seq_read, | |
098c879e | 5493 | .llseek = tracing_lseek, |
756d17ee | 5494 | .release = ftrace_pid_release, |
df4fc315 SR |
5495 | }; |
5496 | ||
8434dc93 | 5497 | static __init int ftrace_init_tracefs(void) |
df4fc315 SR |
5498 | { |
5499 | struct dentry *d_tracer; | |
df4fc315 SR |
5500 | |
5501 | d_tracer = tracing_init_dentry(); | |
14a5ae40 | 5502 | if (IS_ERR(d_tracer)) |
df4fc315 SR |
5503 | return 0; |
5504 | ||
8434dc93 | 5505 | ftrace_init_dyn_tracefs(d_tracer); |
df4fc315 | 5506 | |
5452af66 FW |
5507 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
5508 | NULL, &ftrace_pid_fops); | |
493762fc | 5509 | |
8434dc93 | 5510 | ftrace_profile_tracefs(d_tracer); |
493762fc | 5511 | |
df4fc315 SR |
5512 | return 0; |
5513 | } | |
8434dc93 | 5514 | fs_initcall(ftrace_init_tracefs); |
df4fc315 | 5515 | |
a2bb6a3d | 5516 | /** |
81adbdc0 | 5517 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
5518 | * |
5519 | * This function should be used by panic code. It stops ftrace | |
5520 | * but in a not so nice way. If you need to simply kill ftrace | |
5521 | * from a non-atomic section, use ftrace_kill. | |
5522 | */ | |
81adbdc0 | 5523 | void ftrace_kill(void) |
a2bb6a3d SR |
5524 | { |
5525 | ftrace_disabled = 1; | |
5526 | ftrace_enabled = 0; | |
a2bb6a3d SR |
5527 | clear_ftrace_function(); |
5528 | } | |
5529 | ||
e0a413f6 SR |
5530 | /** |
5531 | * Test if ftrace is dead or not. | |
5532 | */ | |
5533 | int ftrace_is_dead(void) | |
5534 | { | |
5535 | return ftrace_disabled; | |
5536 | } | |
5537 | ||
16444a8a | 5538 | /** |
3d083395 SR |
5539 | * register_ftrace_function - register a function for profiling |
5540 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 5541 | * |
3d083395 SR |
5542 | * Register a function to be called by all functions in the |
5543 | * kernel. | |
5544 | * | |
5545 | * Note: @ops->func and all the functions it calls must be labeled | |
5546 | * with "notrace", otherwise it will go into a | |
5547 | * recursive loop. | |
16444a8a | 5548 | */ |
3d083395 | 5549 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 5550 | { |
45a4a237 | 5551 | int ret = -1; |
4eebcc81 | 5552 | |
f04f24fb MH |
5553 | ftrace_ops_init(ops); |
5554 | ||
e6ea44e9 | 5555 | mutex_lock(&ftrace_lock); |
e7d3737e | 5556 | |
8a56d776 | 5557 | ret = ftrace_startup(ops, 0); |
b848914c | 5558 | |
e6ea44e9 | 5559 | mutex_unlock(&ftrace_lock); |
8d240dd8 | 5560 | |
b0fc494f | 5561 | return ret; |
3d083395 | 5562 | } |
cdbe61bf | 5563 | EXPORT_SYMBOL_GPL(register_ftrace_function); |
3d083395 SR |
5564 | |
5565 | /** | |
32632920 | 5566 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
5567 | * @ops - ops structure that holds the function to unregister |
5568 | * | |
5569 | * Unregister a function that was added to be called by ftrace profiling. | |
5570 | */ | |
5571 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
5572 | { | |
5573 | int ret; | |
5574 | ||
e6ea44e9 | 5575 | mutex_lock(&ftrace_lock); |
8a56d776 | 5576 | ret = ftrace_shutdown(ops, 0); |
e6ea44e9 | 5577 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
5578 | |
5579 | return ret; | |
5580 | } | |
cdbe61bf | 5581 | EXPORT_SYMBOL_GPL(unregister_ftrace_function); |
b0fc494f | 5582 | |
e309b41d | 5583 | int |
b0fc494f | 5584 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
8d65af78 | 5585 | void __user *buffer, size_t *lenp, |
b0fc494f SR |
5586 | loff_t *ppos) |
5587 | { | |
45a4a237 | 5588 | int ret = -ENODEV; |
4eebcc81 | 5589 | |
e6ea44e9 | 5590 | mutex_lock(&ftrace_lock); |
b0fc494f | 5591 | |
45a4a237 SR |
5592 | if (unlikely(ftrace_disabled)) |
5593 | goto out; | |
5594 | ||
5595 | ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
b0fc494f | 5596 | |
a32c7765 | 5597 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
5598 | goto out; |
5599 | ||
a32c7765 | 5600 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f SR |
5601 | |
5602 | if (ftrace_enabled) { | |
5603 | ||
b0fc494f | 5604 | /* we are starting ftrace again */ |
5000c418 JK |
5605 | if (ftrace_ops_list != &ftrace_list_end) |
5606 | update_ftrace_function(); | |
b0fc494f | 5607 | |
524a3868 SRRH |
5608 | ftrace_startup_sysctl(); |
5609 | ||
b0fc494f SR |
5610 | } else { |
5611 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
5612 | ftrace_trace_function = ftrace_stub; | |
5613 | ||
5614 | ftrace_shutdown_sysctl(); | |
5615 | } | |
5616 | ||
5617 | out: | |
e6ea44e9 | 5618 | mutex_unlock(&ftrace_lock); |
3d083395 | 5619 | return ret; |
16444a8a | 5620 | } |
f17845e5 | 5621 | |
fb52607a | 5622 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 5623 | |
5f151b24 SRRH |
5624 | static struct ftrace_ops graph_ops = { |
5625 | .func = ftrace_stub, | |
5626 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | | |
5627 | FTRACE_OPS_FL_INITIALIZED | | |
e3eea140 | 5628 | FTRACE_OPS_FL_PID | |
5f151b24 SRRH |
5629 | FTRACE_OPS_FL_STUB, |
5630 | #ifdef FTRACE_GRAPH_TRAMP_ADDR | |
5631 | .trampoline = FTRACE_GRAPH_TRAMP_ADDR, | |
aec0be2d | 5632 | /* trampoline_size is only needed for dynamically allocated tramps */ |
5f151b24 SRRH |
5633 | #endif |
5634 | ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash) | |
5635 | }; | |
5636 | ||
e49dc19c SR |
5637 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
5638 | { | |
5639 | return 0; | |
5640 | } | |
5641 | ||
287b6e68 FW |
5642 | /* The callbacks that hook a function */ |
5643 | trace_func_graph_ret_t ftrace_graph_return = | |
5644 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 5645 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
23a8e844 | 5646 | static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
5647 | |
5648 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
5649 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
5650 | { | |
5651 | int i; | |
5652 | int ret = 0; | |
5653 | unsigned long flags; | |
5654 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
5655 | struct task_struct *g, *t; | |
5656 | ||
5657 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
5658 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
5659 | * sizeof(struct ftrace_ret_stack), | |
5660 | GFP_KERNEL); | |
5661 | if (!ret_stack_list[i]) { | |
5662 | start = 0; | |
5663 | end = i; | |
5664 | ret = -ENOMEM; | |
5665 | goto free; | |
5666 | } | |
5667 | } | |
5668 | ||
5669 | read_lock_irqsave(&tasklist_lock, flags); | |
5670 | do_each_thread(g, t) { | |
5671 | if (start == end) { | |
5672 | ret = -EAGAIN; | |
5673 | goto unlock; | |
5674 | } | |
5675 | ||
5676 | if (t->ret_stack == NULL) { | |
380c4b14 | 5677 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 5678 | atomic_set(&t->trace_overrun, 0); |
26c01624 SR |
5679 | t->curr_ret_stack = -1; |
5680 | /* Make sure the tasks see the -1 first: */ | |
5681 | smp_wmb(); | |
5682 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
5683 | } |
5684 | } while_each_thread(g, t); | |
5685 | ||
5686 | unlock: | |
5687 | read_unlock_irqrestore(&tasklist_lock, flags); | |
5688 | free: | |
5689 | for (i = start; i < end; i++) | |
5690 | kfree(ret_stack_list[i]); | |
5691 | return ret; | |
5692 | } | |
5693 | ||
8aef2d28 | 5694 | static void |
38516ab5 SR |
5695 | ftrace_graph_probe_sched_switch(void *ignore, |
5696 | struct task_struct *prev, struct task_struct *next) | |
8aef2d28 SR |
5697 | { |
5698 | unsigned long long timestamp; | |
5699 | int index; | |
5700 | ||
be6f164a SR |
5701 | /* |
5702 | * Does the user want to count the time a function was asleep. | |
5703 | * If so, do not update the time stamps. | |
5704 | */ | |
5705 | if (trace_flags & TRACE_ITER_SLEEP_TIME) | |
5706 | return; | |
5707 | ||
8aef2d28 SR |
5708 | timestamp = trace_clock_local(); |
5709 | ||
5710 | prev->ftrace_timestamp = timestamp; | |
5711 | ||
5712 | /* only process tasks that we timestamped */ | |
5713 | if (!next->ftrace_timestamp) | |
5714 | return; | |
5715 | ||
5716 | /* | |
5717 | * Update all the counters in next to make up for the | |
5718 | * time next was sleeping. | |
5719 | */ | |
5720 | timestamp -= next->ftrace_timestamp; | |
5721 | ||
5722 | for (index = next->curr_ret_stack; index >= 0; index--) | |
5723 | next->ret_stack[index].calltime += timestamp; | |
5724 | } | |
5725 | ||
f201ae23 | 5726 | /* Allocate a return stack for each task */ |
fb52607a | 5727 | static int start_graph_tracing(void) |
f201ae23 FW |
5728 | { |
5729 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 5730 | int ret, cpu; |
f201ae23 FW |
5731 | |
5732 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
5733 | sizeof(struct ftrace_ret_stack *), | |
5734 | GFP_KERNEL); | |
5735 | ||
5736 | if (!ret_stack_list) | |
5737 | return -ENOMEM; | |
5738 | ||
5b058bcd | 5739 | /* The cpu_boot init_task->ret_stack will never be freed */ |
179c498a SR |
5740 | for_each_online_cpu(cpu) { |
5741 | if (!idle_task(cpu)->ret_stack) | |
868baf07 | 5742 | ftrace_graph_init_idle_task(idle_task(cpu), cpu); |
179c498a | 5743 | } |
5b058bcd | 5744 | |
f201ae23 FW |
5745 | do { |
5746 | ret = alloc_retstack_tasklist(ret_stack_list); | |
5747 | } while (ret == -EAGAIN); | |
5748 | ||
8aef2d28 | 5749 | if (!ret) { |
38516ab5 | 5750 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
8aef2d28 SR |
5751 | if (ret) |
5752 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
5753 | " probe to kernel_sched_switch\n"); | |
5754 | } | |
5755 | ||
f201ae23 FW |
5756 | kfree(ret_stack_list); |
5757 | return ret; | |
5758 | } | |
5759 | ||
4a2b8dda FW |
5760 | /* |
5761 | * Hibernation protection. | |
5762 | * The state of the current task is too much unstable during | |
5763 | * suspend/restore to disk. We want to protect against that. | |
5764 | */ | |
5765 | static int | |
5766 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
5767 | void *unused) | |
5768 | { | |
5769 | switch (state) { | |
5770 | case PM_HIBERNATION_PREPARE: | |
5771 | pause_graph_tracing(); | |
5772 | break; | |
5773 | ||
5774 | case PM_POST_HIBERNATION: | |
5775 | unpause_graph_tracing(); | |
5776 | break; | |
5777 | } | |
5778 | return NOTIFY_DONE; | |
5779 | } | |
5780 | ||
23a8e844 SRRH |
5781 | static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace) |
5782 | { | |
5783 | if (!ftrace_ops_test(&global_ops, trace->func, NULL)) | |
5784 | return 0; | |
5785 | return __ftrace_graph_entry(trace); | |
5786 | } | |
5787 | ||
5788 | /* | |
5789 | * The function graph tracer should only trace the functions defined | |
5790 | * by set_ftrace_filter and set_ftrace_notrace. If another function | |
5791 | * tracer ops is registered, the graph tracer requires testing the | |
5792 | * function against the global ops, and not just trace any function | |
5793 | * that any ftrace_ops registered. | |
5794 | */ | |
5795 | static void update_function_graph_func(void) | |
5796 | { | |
5f151b24 SRRH |
5797 | struct ftrace_ops *op; |
5798 | bool do_test = false; | |
5799 | ||
5800 | /* | |
5801 | * The graph and global ops share the same set of functions | |
5802 | * to test. If any other ops is on the list, then | |
5803 | * the graph tracing needs to test if its the function | |
5804 | * it should call. | |
5805 | */ | |
5806 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
5807 | if (op != &global_ops && op != &graph_ops && | |
5808 | op != &ftrace_list_end) { | |
5809 | do_test = true; | |
5810 | /* in double loop, break out with goto */ | |
5811 | goto out; | |
5812 | } | |
5813 | } while_for_each_ftrace_op(op); | |
5814 | out: | |
5815 | if (do_test) | |
23a8e844 | 5816 | ftrace_graph_entry = ftrace_graph_entry_test; |
5f151b24 SRRH |
5817 | else |
5818 | ftrace_graph_entry = __ftrace_graph_entry; | |
23a8e844 SRRH |
5819 | } |
5820 | ||
8275f69f MK |
5821 | static struct notifier_block ftrace_suspend_notifier = { |
5822 | .notifier_call = ftrace_suspend_notifier_call, | |
5823 | }; | |
5824 | ||
287b6e68 FW |
5825 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
5826 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 5827 | { |
e7d3737e FW |
5828 | int ret = 0; |
5829 | ||
e6ea44e9 | 5830 | mutex_lock(&ftrace_lock); |
e7d3737e | 5831 | |
05ce5818 | 5832 | /* we currently allow only one tracer registered at a time */ |
597af815 | 5833 | if (ftrace_graph_active) { |
05ce5818 SR |
5834 | ret = -EBUSY; |
5835 | goto out; | |
5836 | } | |
5837 | ||
4a2b8dda FW |
5838 | register_pm_notifier(&ftrace_suspend_notifier); |
5839 | ||
597af815 | 5840 | ftrace_graph_active++; |
fb52607a | 5841 | ret = start_graph_tracing(); |
f201ae23 | 5842 | if (ret) { |
597af815 | 5843 | ftrace_graph_active--; |
f201ae23 FW |
5844 | goto out; |
5845 | } | |
e53a6319 | 5846 | |
287b6e68 | 5847 | ftrace_graph_return = retfunc; |
23a8e844 SRRH |
5848 | |
5849 | /* | |
5850 | * Update the indirect function to the entryfunc, and the | |
5851 | * function that gets called to the entry_test first. Then | |
5852 | * call the update fgraph entry function to determine if | |
5853 | * the entryfunc should be called directly or not. | |
5854 | */ | |
5855 | __ftrace_graph_entry = entryfunc; | |
5856 | ftrace_graph_entry = ftrace_graph_entry_test; | |
5857 | update_function_graph_func(); | |
e53a6319 | 5858 | |
5f151b24 | 5859 | ret = ftrace_startup(&graph_ops, FTRACE_START_FUNC_RET); |
e7d3737e | 5860 | out: |
e6ea44e9 | 5861 | mutex_unlock(&ftrace_lock); |
e7d3737e | 5862 | return ret; |
15e6cb36 FW |
5863 | } |
5864 | ||
fb52607a | 5865 | void unregister_ftrace_graph(void) |
15e6cb36 | 5866 | { |
e6ea44e9 | 5867 | mutex_lock(&ftrace_lock); |
e7d3737e | 5868 | |
597af815 | 5869 | if (unlikely(!ftrace_graph_active)) |
2aad1b76 SR |
5870 | goto out; |
5871 | ||
597af815 | 5872 | ftrace_graph_active--; |
287b6e68 | 5873 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 5874 | ftrace_graph_entry = ftrace_graph_entry_stub; |
23a8e844 | 5875 | __ftrace_graph_entry = ftrace_graph_entry_stub; |
5f151b24 | 5876 | ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET); |
4a2b8dda | 5877 | unregister_pm_notifier(&ftrace_suspend_notifier); |
38516ab5 | 5878 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
e7d3737e | 5879 | |
f3bea491 SRRH |
5880 | #ifdef CONFIG_DYNAMIC_FTRACE |
5881 | /* | |
5882 | * Function graph does not allocate the trampoline, but | |
5883 | * other global_ops do. We need to reset the ALLOC_TRAMP flag | |
5884 | * if one was used. | |
5885 | */ | |
5886 | global_ops.trampoline = save_global_trampoline; | |
5887 | if (save_global_flags & FTRACE_OPS_FL_ALLOC_TRAMP) | |
5888 | global_ops.flags |= FTRACE_OPS_FL_ALLOC_TRAMP; | |
5889 | #endif | |
5890 | ||
2aad1b76 | 5891 | out: |
e6ea44e9 | 5892 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 5893 | } |
f201ae23 | 5894 | |
868baf07 SR |
5895 | static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack); |
5896 | ||
5897 | static void | |
5898 | graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack) | |
5899 | { | |
5900 | atomic_set(&t->tracing_graph_pause, 0); | |
5901 | atomic_set(&t->trace_overrun, 0); | |
5902 | t->ftrace_timestamp = 0; | |
25985edc | 5903 | /* make curr_ret_stack visible before we add the ret_stack */ |
868baf07 SR |
5904 | smp_wmb(); |
5905 | t->ret_stack = ret_stack; | |
5906 | } | |
5907 | ||
5908 | /* | |
5909 | * Allocate a return stack for the idle task. May be the first | |
5910 | * time through, or it may be done by CPU hotplug online. | |
5911 | */ | |
5912 | void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) | |
5913 | { | |
5914 | t->curr_ret_stack = -1; | |
5915 | /* | |
5916 | * The idle task has no parent, it either has its own | |
5917 | * stack or no stack at all. | |
5918 | */ | |
5919 | if (t->ret_stack) | |
5920 | WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu)); | |
5921 | ||
5922 | if (ftrace_graph_active) { | |
5923 | struct ftrace_ret_stack *ret_stack; | |
5924 | ||
5925 | ret_stack = per_cpu(idle_ret_stack, cpu); | |
5926 | if (!ret_stack) { | |
5927 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
5928 | * sizeof(struct ftrace_ret_stack), | |
5929 | GFP_KERNEL); | |
5930 | if (!ret_stack) | |
5931 | return; | |
5932 | per_cpu(idle_ret_stack, cpu) = ret_stack; | |
5933 | } | |
5934 | graph_init_task(t, ret_stack); | |
5935 | } | |
5936 | } | |
5937 | ||
f201ae23 | 5938 | /* Allocate a return stack for newly created task */ |
fb52607a | 5939 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 5940 | { |
84047e36 SR |
5941 | /* Make sure we do not use the parent ret_stack */ |
5942 | t->ret_stack = NULL; | |
ea14eb71 | 5943 | t->curr_ret_stack = -1; |
84047e36 | 5944 | |
597af815 | 5945 | if (ftrace_graph_active) { |
82310a32 SR |
5946 | struct ftrace_ret_stack *ret_stack; |
5947 | ||
5948 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
f201ae23 FW |
5949 | * sizeof(struct ftrace_ret_stack), |
5950 | GFP_KERNEL); | |
82310a32 | 5951 | if (!ret_stack) |
f201ae23 | 5952 | return; |
868baf07 | 5953 | graph_init_task(t, ret_stack); |
84047e36 | 5954 | } |
f201ae23 FW |
5955 | } |
5956 | ||
fb52607a | 5957 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 5958 | { |
eae849ca FW |
5959 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
5960 | ||
f201ae23 | 5961 | t->ret_stack = NULL; |
eae849ca FW |
5962 | /* NULL must become visible to IRQs before we free it: */ |
5963 | barrier(); | |
5964 | ||
5965 | kfree(ret_stack); | |
f201ae23 | 5966 | } |
15e6cb36 | 5967 | #endif |