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 | |
f04f24fb | 65 | #ifdef CONFIG_DYNAMIC_FTRACE |
33b7f99c SRRH |
66 | #define INIT_OPS_HASH(opsname) \ |
67 | .func_hash = &opsname.local_hash, \ | |
68 | .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock), | |
5f151b24 SRRH |
69 | #define ASSIGN_OPS_HASH(opsname, val) \ |
70 | .func_hash = val, \ | |
71 | .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock), | |
f04f24fb | 72 | #else |
33b7f99c | 73 | #define INIT_OPS_HASH(opsname) |
5f151b24 | 74 | #define ASSIGN_OPS_HASH(opsname, val) |
f04f24fb MH |
75 | #endif |
76 | ||
2f5f6ad9 SR |
77 | static struct ftrace_ops ftrace_list_end __read_mostly = { |
78 | .func = ftrace_stub, | |
395b97a3 | 79 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB, |
33b7f99c | 80 | INIT_OPS_HASH(ftrace_list_end) |
2f5f6ad9 SR |
81 | }; |
82 | ||
4eebcc81 SR |
83 | /* ftrace_enabled is a method to turn ftrace on or off */ |
84 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 85 | static int last_ftrace_enabled; |
b0fc494f | 86 | |
2f5f6ad9 SR |
87 | /* Current function tracing op */ |
88 | struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end; | |
405e1d83 SRRH |
89 | /* What to set function_trace_op to */ |
90 | static struct ftrace_ops *set_function_trace_op; | |
60a7ecf4 | 91 | |
756d17ee | 92 | /* List for set_ftrace_pid's pids. */ |
93 | LIST_HEAD(ftrace_pids); | |
94 | struct ftrace_pid { | |
95 | struct list_head list; | |
96 | struct pid *pid; | |
97 | }; | |
98 | ||
e3eea140 SRRH |
99 | static bool ftrace_pids_enabled(void) |
100 | { | |
101 | return !list_empty(&ftrace_pids); | |
102 | } | |
103 | ||
104 | static void ftrace_update_trampoline(struct ftrace_ops *ops); | |
105 | ||
4eebcc81 SR |
106 | /* |
107 | * ftrace_disabled is set when an anomaly is discovered. | |
108 | * ftrace_disabled is much stronger than ftrace_enabled. | |
109 | */ | |
110 | static int ftrace_disabled __read_mostly; | |
111 | ||
52baf119 | 112 | static DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 113 | |
b848914c | 114 | static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end; |
16444a8a | 115 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
2b499381 | 116 | static struct ftrace_ops global_ops; |
16444a8a | 117 | |
2f5f6ad9 SR |
118 | #if ARCH_SUPPORTS_FTRACE_OPS |
119 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 120 | struct ftrace_ops *op, struct pt_regs *regs); |
2f5f6ad9 SR |
121 | #else |
122 | /* See comment below, where ftrace_ops_list_func is defined */ | |
123 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip); | |
124 | #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops) | |
125 | #endif | |
b848914c | 126 | |
0a016409 SR |
127 | /* |
128 | * Traverse the ftrace_global_list, invoking all entries. The reason that we | |
1bb539ca | 129 | * can use rcu_dereference_raw_notrace() is that elements removed from this list |
0a016409 | 130 | * are simply leaked, so there is no need to interact with a grace-period |
1bb539ca | 131 | * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle |
0a016409 SR |
132 | * concurrent insertions into the ftrace_global_list. |
133 | * | |
134 | * Silly Alpha and silly pointer-speculation compiler optimizations! | |
135 | */ | |
136 | #define do_for_each_ftrace_op(op, list) \ | |
1bb539ca | 137 | op = rcu_dereference_raw_notrace(list); \ |
0a016409 SR |
138 | do |
139 | ||
140 | /* | |
141 | * Optimized for just a single item in the list (as that is the normal case). | |
142 | */ | |
143 | #define while_for_each_ftrace_op(op) \ | |
1bb539ca | 144 | while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \ |
0a016409 SR |
145 | unlikely((op) != &ftrace_list_end)) |
146 | ||
f04f24fb MH |
147 | static inline void ftrace_ops_init(struct ftrace_ops *ops) |
148 | { | |
149 | #ifdef CONFIG_DYNAMIC_FTRACE | |
150 | if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) { | |
33b7f99c SRRH |
151 | mutex_init(&ops->local_hash.regex_lock); |
152 | ops->func_hash = &ops->local_hash; | |
f04f24fb MH |
153 | ops->flags |= FTRACE_OPS_FL_INITIALIZED; |
154 | } | |
155 | #endif | |
156 | } | |
157 | ||
ea701f11 SR |
158 | /** |
159 | * ftrace_nr_registered_ops - return number of ops registered | |
160 | * | |
161 | * Returns the number of ftrace_ops registered and tracing functions | |
162 | */ | |
163 | int ftrace_nr_registered_ops(void) | |
164 | { | |
165 | struct ftrace_ops *ops; | |
166 | int cnt = 0; | |
167 | ||
168 | mutex_lock(&ftrace_lock); | |
169 | ||
170 | for (ops = ftrace_ops_list; | |
171 | ops != &ftrace_list_end; ops = ops->next) | |
172 | cnt++; | |
173 | ||
174 | mutex_unlock(&ftrace_lock); | |
175 | ||
176 | return cnt; | |
177 | } | |
178 | ||
2f5f6ad9 | 179 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 180 | struct ftrace_ops *op, struct pt_regs *regs) |
df4fc315 | 181 | { |
0ef8cde5 | 182 | if (!test_tsk_trace_trace(current)) |
df4fc315 SR |
183 | return; |
184 | ||
e3eea140 | 185 | op->saved_func(ip, parent_ip, op, regs); |
df4fc315 SR |
186 | } |
187 | ||
16444a8a | 188 | /** |
3d083395 | 189 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 190 | * |
3d083395 SR |
191 | * This NULLs the ftrace function and in essence stops |
192 | * tracing. There may be lag | |
16444a8a | 193 | */ |
3d083395 | 194 | void clear_ftrace_function(void) |
16444a8a | 195 | { |
3d083395 SR |
196 | ftrace_trace_function = ftrace_stub; |
197 | } | |
198 | ||
ba27f2bc | 199 | static void per_cpu_ops_disable_all(struct ftrace_ops *ops) |
e248491a JO |
200 | { |
201 | int cpu; | |
202 | ||
203 | for_each_possible_cpu(cpu) | |
204 | *per_cpu_ptr(ops->disabled, cpu) = 1; | |
205 | } | |
206 | ||
ba27f2bc | 207 | static int per_cpu_ops_alloc(struct ftrace_ops *ops) |
e248491a JO |
208 | { |
209 | int __percpu *disabled; | |
210 | ||
ba27f2bc SRRH |
211 | if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_PER_CPU))) |
212 | return -EINVAL; | |
213 | ||
e248491a JO |
214 | disabled = alloc_percpu(int); |
215 | if (!disabled) | |
216 | return -ENOMEM; | |
217 | ||
218 | ops->disabled = disabled; | |
ba27f2bc | 219 | per_cpu_ops_disable_all(ops); |
e248491a JO |
220 | return 0; |
221 | } | |
222 | ||
405e1d83 SRRH |
223 | static void ftrace_sync(struct work_struct *work) |
224 | { | |
225 | /* | |
226 | * This function is just a stub to implement a hard force | |
227 | * of synchronize_sched(). This requires synchronizing | |
228 | * tasks even in userspace and idle. | |
229 | * | |
230 | * Yes, function tracing is rude. | |
231 | */ | |
232 | } | |
233 | ||
234 | static void ftrace_sync_ipi(void *data) | |
235 | { | |
236 | /* Probably not needed, but do it anyway */ | |
237 | smp_rmb(); | |
238 | } | |
239 | ||
23a8e844 SRRH |
240 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
241 | static void update_function_graph_func(void); | |
55577204 SRRH |
242 | |
243 | /* Both enabled by default (can be cleared by function_graph tracer flags */ | |
244 | static bool fgraph_sleep_time = true; | |
245 | static bool fgraph_graph_time = true; | |
246 | ||
23a8e844 SRRH |
247 | #else |
248 | static inline void update_function_graph_func(void) { } | |
249 | #endif | |
250 | ||
00ccbf2f SRRH |
251 | |
252 | static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops) | |
253 | { | |
254 | /* | |
ba27f2bc | 255 | * If this is a dynamic, RCU, or per CPU ops, or we force list func, |
00ccbf2f SRRH |
256 | * then it needs to call the list anyway. |
257 | */ | |
ba27f2bc SRRH |
258 | if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_PER_CPU | |
259 | FTRACE_OPS_FL_RCU) || FTRACE_FORCE_LIST_FUNC) | |
00ccbf2f SRRH |
260 | return ftrace_ops_list_func; |
261 | ||
262 | return ftrace_ops_get_func(ops); | |
263 | } | |
264 | ||
2b499381 SR |
265 | static void update_ftrace_function(void) |
266 | { | |
267 | ftrace_func_t func; | |
268 | ||
f7aad4e1 SRRH |
269 | /* |
270 | * Prepare the ftrace_ops that the arch callback will use. | |
271 | * If there's only one ftrace_ops registered, the ftrace_ops_list | |
272 | * will point to the ops we want. | |
273 | */ | |
274 | set_function_trace_op = ftrace_ops_list; | |
275 | ||
276 | /* If there's no ftrace_ops registered, just call the stub function */ | |
277 | if (ftrace_ops_list == &ftrace_list_end) { | |
278 | func = ftrace_stub; | |
279 | ||
cdbe61bf SR |
280 | /* |
281 | * If we are at the end of the list and this ops is | |
4740974a SR |
282 | * recursion safe and not dynamic and the arch supports passing ops, |
283 | * then have the mcount trampoline call the function directly. | |
cdbe61bf | 284 | */ |
f7aad4e1 | 285 | } else if (ftrace_ops_list->next == &ftrace_list_end) { |
00ccbf2f | 286 | func = ftrace_ops_get_list_func(ftrace_ops_list); |
f7aad4e1 | 287 | |
2f5f6ad9 SR |
288 | } else { |
289 | /* Just use the default ftrace_ops */ | |
405e1d83 | 290 | set_function_trace_op = &ftrace_list_end; |
b848914c | 291 | func = ftrace_ops_list_func; |
2f5f6ad9 | 292 | } |
2b499381 | 293 | |
5f8bf2d2 SRRH |
294 | update_function_graph_func(); |
295 | ||
405e1d83 SRRH |
296 | /* If there's no change, then do nothing more here */ |
297 | if (ftrace_trace_function == func) | |
298 | return; | |
299 | ||
300 | /* | |
301 | * If we are using the list function, it doesn't care | |
302 | * about the function_trace_ops. | |
303 | */ | |
304 | if (func == ftrace_ops_list_func) { | |
305 | ftrace_trace_function = func; | |
306 | /* | |
307 | * Don't even bother setting function_trace_ops, | |
308 | * it would be racy to do so anyway. | |
309 | */ | |
310 | return; | |
311 | } | |
312 | ||
313 | #ifndef CONFIG_DYNAMIC_FTRACE | |
314 | /* | |
315 | * For static tracing, we need to be a bit more careful. | |
316 | * The function change takes affect immediately. Thus, | |
317 | * we need to coorditate the setting of the function_trace_ops | |
318 | * with the setting of the ftrace_trace_function. | |
319 | * | |
320 | * Set the function to the list ops, which will call the | |
321 | * function we want, albeit indirectly, but it handles the | |
322 | * ftrace_ops and doesn't depend on function_trace_op. | |
323 | */ | |
324 | ftrace_trace_function = ftrace_ops_list_func; | |
325 | /* | |
326 | * Make sure all CPUs see this. Yes this is slow, but static | |
327 | * tracing is slow and nasty to have enabled. | |
328 | */ | |
329 | schedule_on_each_cpu(ftrace_sync); | |
330 | /* Now all cpus are using the list ops. */ | |
331 | function_trace_op = set_function_trace_op; | |
332 | /* Make sure the function_trace_op is visible on all CPUs */ | |
333 | smp_wmb(); | |
334 | /* Nasty way to force a rmb on all cpus */ | |
335 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
336 | /* OK, we are all set to update the ftrace_trace_function now! */ | |
337 | #endif /* !CONFIG_DYNAMIC_FTRACE */ | |
338 | ||
491d0dcf | 339 | ftrace_trace_function = func; |
491d0dcf SR |
340 | } |
341 | ||
7eea4fce JW |
342 | int using_ftrace_ops_list_func(void) |
343 | { | |
344 | return ftrace_trace_function == ftrace_ops_list_func; | |
345 | } | |
346 | ||
2b499381 | 347 | static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
3d083395 | 348 | { |
2b499381 | 349 | ops->next = *list; |
16444a8a | 350 | /* |
b848914c | 351 | * We are entering ops into the list but another |
16444a8a ACM |
352 | * CPU might be walking that list. We need to make sure |
353 | * the ops->next pointer is valid before another CPU sees | |
b848914c | 354 | * the ops pointer included into the list. |
16444a8a | 355 | */ |
2b499381 | 356 | rcu_assign_pointer(*list, ops); |
16444a8a ACM |
357 | } |
358 | ||
2b499381 | 359 | static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
16444a8a | 360 | { |
16444a8a | 361 | struct ftrace_ops **p; |
16444a8a ACM |
362 | |
363 | /* | |
3d083395 SR |
364 | * If we are removing the last function, then simply point |
365 | * to the ftrace_stub. | |
16444a8a | 366 | */ |
2b499381 SR |
367 | if (*list == ops && ops->next == &ftrace_list_end) { |
368 | *list = &ftrace_list_end; | |
e6ea44e9 | 369 | return 0; |
16444a8a ACM |
370 | } |
371 | ||
2b499381 | 372 | for (p = list; *p != &ftrace_list_end; p = &(*p)->next) |
16444a8a ACM |
373 | if (*p == ops) |
374 | break; | |
375 | ||
e6ea44e9 SR |
376 | if (*p != ops) |
377 | return -1; | |
16444a8a ACM |
378 | |
379 | *p = (*p)->next; | |
2b499381 SR |
380 | return 0; |
381 | } | |
16444a8a | 382 | |
f3bea491 SRRH |
383 | static void ftrace_update_trampoline(struct ftrace_ops *ops); |
384 | ||
2b499381 SR |
385 | static int __register_ftrace_function(struct ftrace_ops *ops) |
386 | { | |
591dffda SRRH |
387 | if (ops->flags & FTRACE_OPS_FL_DELETED) |
388 | return -EINVAL; | |
389 | ||
b848914c SR |
390 | if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) |
391 | return -EBUSY; | |
392 | ||
06aeaaea | 393 | #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
08f6fba5 SR |
394 | /* |
395 | * If the ftrace_ops specifies SAVE_REGS, then it only can be used | |
396 | * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set. | |
397 | * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant. | |
398 | */ | |
399 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS && | |
400 | !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)) | |
401 | return -EINVAL; | |
402 | ||
403 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED) | |
404 | ops->flags |= FTRACE_OPS_FL_SAVE_REGS; | |
405 | #endif | |
406 | ||
cdbe61bf SR |
407 | if (!core_kernel_data((unsigned long)ops)) |
408 | ops->flags |= FTRACE_OPS_FL_DYNAMIC; | |
409 | ||
ba27f2bc SRRH |
410 | if (ops->flags & FTRACE_OPS_FL_PER_CPU) { |
411 | if (per_cpu_ops_alloc(ops)) | |
e248491a | 412 | return -ENOMEM; |
ba27f2bc SRRH |
413 | } |
414 | ||
415 | add_ftrace_ops(&ftrace_ops_list, ops); | |
b848914c | 416 | |
e3eea140 SRRH |
417 | /* Always save the function, and reset at unregistering */ |
418 | ops->saved_func = ops->func; | |
419 | ||
420 | if (ops->flags & FTRACE_OPS_FL_PID && ftrace_pids_enabled()) | |
421 | ops->func = ftrace_pid_func; | |
422 | ||
f3bea491 SRRH |
423 | ftrace_update_trampoline(ops); |
424 | ||
2b499381 SR |
425 | if (ftrace_enabled) |
426 | update_ftrace_function(); | |
427 | ||
428 | return 0; | |
429 | } | |
430 | ||
431 | static int __unregister_ftrace_function(struct ftrace_ops *ops) | |
432 | { | |
433 | int ret; | |
434 | ||
b848914c SR |
435 | if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) |
436 | return -EBUSY; | |
437 | ||
ba27f2bc | 438 | ret = remove_ftrace_ops(&ftrace_ops_list, ops); |
b848914c | 439 | |
2b499381 SR |
440 | if (ret < 0) |
441 | return ret; | |
b848914c | 442 | |
491d0dcf SR |
443 | if (ftrace_enabled) |
444 | update_ftrace_function(); | |
16444a8a | 445 | |
e3eea140 SRRH |
446 | ops->func = ops->saved_func; |
447 | ||
e6ea44e9 | 448 | return 0; |
3d083395 SR |
449 | } |
450 | ||
df4fc315 SR |
451 | static void ftrace_update_pid_func(void) |
452 | { | |
e3eea140 SRRH |
453 | bool enabled = ftrace_pids_enabled(); |
454 | struct ftrace_ops *op; | |
455 | ||
491d0dcf | 456 | /* Only do something if we are tracing something */ |
df4fc315 | 457 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 458 | return; |
df4fc315 | 459 | |
e3eea140 SRRH |
460 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
461 | if (op->flags & FTRACE_OPS_FL_PID) { | |
462 | op->func = enabled ? ftrace_pid_func : | |
463 | op->saved_func; | |
464 | ftrace_update_trampoline(op); | |
465 | } | |
466 | } while_for_each_ftrace_op(op); | |
467 | ||
491d0dcf | 468 | update_ftrace_function(); |
df4fc315 SR |
469 | } |
470 | ||
493762fc SR |
471 | #ifdef CONFIG_FUNCTION_PROFILER |
472 | struct ftrace_profile { | |
473 | struct hlist_node node; | |
474 | unsigned long ip; | |
475 | unsigned long counter; | |
0706f1c4 SR |
476 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
477 | unsigned long long time; | |
e330b3bc | 478 | unsigned long long time_squared; |
0706f1c4 | 479 | #endif |
8fc0c701 SR |
480 | }; |
481 | ||
493762fc SR |
482 | struct ftrace_profile_page { |
483 | struct ftrace_profile_page *next; | |
484 | unsigned long index; | |
485 | struct ftrace_profile records[]; | |
d61f82d0 SR |
486 | }; |
487 | ||
cafb168a SR |
488 | struct ftrace_profile_stat { |
489 | atomic_t disabled; | |
490 | struct hlist_head *hash; | |
491 | struct ftrace_profile_page *pages; | |
492 | struct ftrace_profile_page *start; | |
493 | struct tracer_stat stat; | |
494 | }; | |
495 | ||
493762fc SR |
496 | #define PROFILE_RECORDS_SIZE \ |
497 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 498 | |
493762fc SR |
499 | #define PROFILES_PER_PAGE \ |
500 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 501 | |
fb9fb015 SR |
502 | static int ftrace_profile_enabled __read_mostly; |
503 | ||
504 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
505 | static DEFINE_MUTEX(ftrace_profile_lock); |
506 | ||
cafb168a | 507 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc | 508 | |
20079ebe NK |
509 | #define FTRACE_PROFILE_HASH_BITS 10 |
510 | #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS) | |
493762fc | 511 | |
bac429f0 SR |
512 | static void * |
513 | function_stat_next(void *v, int idx) | |
514 | { | |
493762fc SR |
515 | struct ftrace_profile *rec = v; |
516 | struct ftrace_profile_page *pg; | |
bac429f0 | 517 | |
493762fc | 518 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
519 | |
520 | again: | |
0296e425 LZ |
521 | if (idx != 0) |
522 | rec++; | |
523 | ||
bac429f0 SR |
524 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
525 | pg = pg->next; | |
526 | if (!pg) | |
527 | return NULL; | |
528 | rec = &pg->records[0]; | |
493762fc SR |
529 | if (!rec->counter) |
530 | goto again; | |
bac429f0 SR |
531 | } |
532 | ||
bac429f0 SR |
533 | return rec; |
534 | } | |
535 | ||
536 | static void *function_stat_start(struct tracer_stat *trace) | |
537 | { | |
cafb168a SR |
538 | struct ftrace_profile_stat *stat = |
539 | container_of(trace, struct ftrace_profile_stat, stat); | |
540 | ||
541 | if (!stat || !stat->start) | |
542 | return NULL; | |
543 | ||
544 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
545 | } |
546 | ||
0706f1c4 SR |
547 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
548 | /* function graph compares on total time */ | |
549 | static int function_stat_cmp(void *p1, void *p2) | |
550 | { | |
551 | struct ftrace_profile *a = p1; | |
552 | struct ftrace_profile *b = p2; | |
553 | ||
554 | if (a->time < b->time) | |
555 | return -1; | |
556 | if (a->time > b->time) | |
557 | return 1; | |
558 | else | |
559 | return 0; | |
560 | } | |
561 | #else | |
562 | /* not function graph compares against hits */ | |
bac429f0 SR |
563 | static int function_stat_cmp(void *p1, void *p2) |
564 | { | |
493762fc SR |
565 | struct ftrace_profile *a = p1; |
566 | struct ftrace_profile *b = p2; | |
bac429f0 SR |
567 | |
568 | if (a->counter < b->counter) | |
569 | return -1; | |
570 | if (a->counter > b->counter) | |
571 | return 1; | |
572 | else | |
573 | return 0; | |
574 | } | |
0706f1c4 | 575 | #endif |
bac429f0 SR |
576 | |
577 | static int function_stat_headers(struct seq_file *m) | |
578 | { | |
0706f1c4 | 579 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
fa6f0cc7 RV |
580 | seq_puts(m, " Function " |
581 | "Hit Time Avg s^2\n" | |
582 | " -------- " | |
583 | "--- ---- --- ---\n"); | |
0706f1c4 | 584 | #else |
fa6f0cc7 RV |
585 | seq_puts(m, " Function Hit\n" |
586 | " -------- ---\n"); | |
0706f1c4 | 587 | #endif |
bac429f0 SR |
588 | return 0; |
589 | } | |
590 | ||
591 | static int function_stat_show(struct seq_file *m, void *v) | |
592 | { | |
493762fc | 593 | struct ftrace_profile *rec = v; |
bac429f0 | 594 | char str[KSYM_SYMBOL_LEN]; |
3aaba20f | 595 | int ret = 0; |
0706f1c4 | 596 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
597 | static struct trace_seq s; |
598 | unsigned long long avg; | |
e330b3bc | 599 | unsigned long long stddev; |
0706f1c4 | 600 | #endif |
3aaba20f LZ |
601 | mutex_lock(&ftrace_profile_lock); |
602 | ||
603 | /* we raced with function_profile_reset() */ | |
604 | if (unlikely(rec->counter == 0)) { | |
605 | ret = -EBUSY; | |
606 | goto out; | |
607 | } | |
bac429f0 | 608 | |
8e436ca0 UT |
609 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
610 | avg = rec->time; | |
611 | do_div(avg, rec->counter); | |
612 | if (tracing_thresh && (avg < tracing_thresh)) | |
613 | goto out; | |
614 | #endif | |
615 | ||
bac429f0 | 616 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
0706f1c4 SR |
617 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
618 | ||
619 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
fa6f0cc7 | 620 | seq_puts(m, " "); |
34886c8b | 621 | |
e330b3bc CD |
622 | /* Sample standard deviation (s^2) */ |
623 | if (rec->counter <= 1) | |
624 | stddev = 0; | |
625 | else { | |
52d85d76 JL |
626 | /* |
627 | * Apply Welford's method: | |
628 | * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2) | |
629 | */ | |
630 | stddev = rec->counter * rec->time_squared - | |
631 | rec->time * rec->time; | |
632 | ||
e330b3bc CD |
633 | /* |
634 | * Divide only 1000 for ns^2 -> us^2 conversion. | |
635 | * trace_print_graph_duration will divide 1000 again. | |
636 | */ | |
52d85d76 | 637 | do_div(stddev, rec->counter * (rec->counter - 1) * 1000); |
e330b3bc CD |
638 | } |
639 | ||
34886c8b SR |
640 | trace_seq_init(&s); |
641 | trace_print_graph_duration(rec->time, &s); | |
642 | trace_seq_puts(&s, " "); | |
643 | trace_print_graph_duration(avg, &s); | |
e330b3bc CD |
644 | trace_seq_puts(&s, " "); |
645 | trace_print_graph_duration(stddev, &s); | |
0706f1c4 | 646 | trace_print_seq(m, &s); |
0706f1c4 SR |
647 | #endif |
648 | seq_putc(m, '\n'); | |
3aaba20f LZ |
649 | out: |
650 | mutex_unlock(&ftrace_profile_lock); | |
bac429f0 | 651 | |
3aaba20f | 652 | return ret; |
bac429f0 SR |
653 | } |
654 | ||
cafb168a | 655 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 656 | { |
493762fc | 657 | struct ftrace_profile_page *pg; |
bac429f0 | 658 | |
cafb168a | 659 | pg = stat->pages = stat->start; |
bac429f0 | 660 | |
493762fc SR |
661 | while (pg) { |
662 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
663 | pg->index = 0; | |
664 | pg = pg->next; | |
bac429f0 SR |
665 | } |
666 | ||
cafb168a | 667 | memset(stat->hash, 0, |
493762fc SR |
668 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
669 | } | |
bac429f0 | 670 | |
cafb168a | 671 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
672 | { |
673 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
674 | int functions; |
675 | int pages; | |
493762fc | 676 | int i; |
bac429f0 | 677 | |
493762fc | 678 | /* If we already allocated, do nothing */ |
cafb168a | 679 | if (stat->pages) |
493762fc | 680 | return 0; |
bac429f0 | 681 | |
cafb168a SR |
682 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
683 | if (!stat->pages) | |
493762fc | 684 | return -ENOMEM; |
bac429f0 | 685 | |
318e0a73 SR |
686 | #ifdef CONFIG_DYNAMIC_FTRACE |
687 | functions = ftrace_update_tot_cnt; | |
688 | #else | |
689 | /* | |
690 | * We do not know the number of functions that exist because | |
691 | * dynamic tracing is what counts them. With past experience | |
692 | * we have around 20K functions. That should be more than enough. | |
693 | * It is highly unlikely we will execute every function in | |
694 | * the kernel. | |
695 | */ | |
696 | functions = 20000; | |
697 | #endif | |
698 | ||
cafb168a | 699 | pg = stat->start = stat->pages; |
bac429f0 | 700 | |
318e0a73 SR |
701 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
702 | ||
39e30cd1 | 703 | for (i = 1; i < pages; i++) { |
493762fc | 704 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 705 | if (!pg->next) |
318e0a73 | 706 | goto out_free; |
493762fc SR |
707 | pg = pg->next; |
708 | } | |
709 | ||
710 | return 0; | |
318e0a73 SR |
711 | |
712 | out_free: | |
713 | pg = stat->start; | |
714 | while (pg) { | |
715 | unsigned long tmp = (unsigned long)pg; | |
716 | ||
717 | pg = pg->next; | |
718 | free_page(tmp); | |
719 | } | |
720 | ||
318e0a73 SR |
721 | stat->pages = NULL; |
722 | stat->start = NULL; | |
723 | ||
724 | return -ENOMEM; | |
bac429f0 SR |
725 | } |
726 | ||
cafb168a | 727 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 728 | { |
cafb168a | 729 | struct ftrace_profile_stat *stat; |
493762fc | 730 | int size; |
bac429f0 | 731 | |
cafb168a SR |
732 | stat = &per_cpu(ftrace_profile_stats, cpu); |
733 | ||
734 | if (stat->hash) { | |
493762fc | 735 | /* If the profile is already created, simply reset it */ |
cafb168a | 736 | ftrace_profile_reset(stat); |
493762fc SR |
737 | return 0; |
738 | } | |
bac429f0 | 739 | |
493762fc SR |
740 | /* |
741 | * We are profiling all functions, but usually only a few thousand | |
742 | * functions are hit. We'll make a hash of 1024 items. | |
743 | */ | |
744 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 745 | |
cafb168a | 746 | stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
493762fc | 747 | |
cafb168a | 748 | if (!stat->hash) |
493762fc SR |
749 | return -ENOMEM; |
750 | ||
318e0a73 | 751 | /* Preallocate the function profiling pages */ |
cafb168a SR |
752 | if (ftrace_profile_pages_init(stat) < 0) { |
753 | kfree(stat->hash); | |
754 | stat->hash = NULL; | |
493762fc SR |
755 | return -ENOMEM; |
756 | } | |
757 | ||
758 | return 0; | |
bac429f0 SR |
759 | } |
760 | ||
cafb168a SR |
761 | static int ftrace_profile_init(void) |
762 | { | |
763 | int cpu; | |
764 | int ret = 0; | |
765 | ||
c4602c1c | 766 | for_each_possible_cpu(cpu) { |
cafb168a SR |
767 | ret = ftrace_profile_init_cpu(cpu); |
768 | if (ret) | |
769 | break; | |
770 | } | |
771 | ||
772 | return ret; | |
773 | } | |
774 | ||
493762fc | 775 | /* interrupts must be disabled */ |
cafb168a SR |
776 | static struct ftrace_profile * |
777 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 778 | { |
493762fc | 779 | struct ftrace_profile *rec; |
bac429f0 | 780 | struct hlist_head *hhd; |
bac429f0 SR |
781 | unsigned long key; |
782 | ||
20079ebe | 783 | key = hash_long(ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 784 | hhd = &stat->hash[key]; |
bac429f0 SR |
785 | |
786 | if (hlist_empty(hhd)) | |
787 | return NULL; | |
788 | ||
1bb539ca | 789 | hlist_for_each_entry_rcu_notrace(rec, hhd, node) { |
bac429f0 | 790 | if (rec->ip == ip) |
493762fc SR |
791 | return rec; |
792 | } | |
793 | ||
794 | return NULL; | |
795 | } | |
796 | ||
cafb168a SR |
797 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
798 | struct ftrace_profile *rec) | |
493762fc SR |
799 | { |
800 | unsigned long key; | |
801 | ||
20079ebe | 802 | key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 803 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
804 | } |
805 | ||
318e0a73 SR |
806 | /* |
807 | * The memory is already allocated, this simply finds a new record to use. | |
808 | */ | |
493762fc | 809 | static struct ftrace_profile * |
318e0a73 | 810 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
811 | { |
812 | struct ftrace_profile *rec = NULL; | |
813 | ||
318e0a73 | 814 | /* prevent recursion (from NMIs) */ |
cafb168a | 815 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
816 | goto out; |
817 | ||
493762fc | 818 | /* |
318e0a73 SR |
819 | * Try to find the function again since an NMI |
820 | * could have added it | |
493762fc | 821 | */ |
cafb168a | 822 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 823 | if (rec) |
cafb168a | 824 | goto out; |
493762fc | 825 | |
cafb168a SR |
826 | if (stat->pages->index == PROFILES_PER_PAGE) { |
827 | if (!stat->pages->next) | |
828 | goto out; | |
829 | stat->pages = stat->pages->next; | |
bac429f0 | 830 | } |
493762fc | 831 | |
cafb168a | 832 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 833 | rec->ip = ip; |
cafb168a | 834 | ftrace_add_profile(stat, rec); |
493762fc | 835 | |
bac429f0 | 836 | out: |
cafb168a | 837 | atomic_dec(&stat->disabled); |
bac429f0 SR |
838 | |
839 | return rec; | |
840 | } | |
841 | ||
842 | static void | |
2f5f6ad9 | 843 | function_profile_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 844 | struct ftrace_ops *ops, struct pt_regs *regs) |
bac429f0 | 845 | { |
cafb168a | 846 | struct ftrace_profile_stat *stat; |
493762fc | 847 | struct ftrace_profile *rec; |
bac429f0 SR |
848 | unsigned long flags; |
849 | ||
850 | if (!ftrace_profile_enabled) | |
851 | return; | |
852 | ||
853 | local_irq_save(flags); | |
cafb168a | 854 | |
bdffd893 | 855 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 856 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
857 | goto out; |
858 | ||
859 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 860 | if (!rec) { |
318e0a73 | 861 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
862 | if (!rec) |
863 | goto out; | |
864 | } | |
bac429f0 SR |
865 | |
866 | rec->counter++; | |
867 | out: | |
868 | local_irq_restore(flags); | |
869 | } | |
870 | ||
0706f1c4 SR |
871 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
872 | static int profile_graph_entry(struct ftrace_graph_ent *trace) | |
873 | { | |
a1e2e31d | 874 | function_profile_call(trace->func, 0, NULL, NULL); |
0706f1c4 SR |
875 | return 1; |
876 | } | |
877 | ||
878 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
879 | { | |
cafb168a | 880 | struct ftrace_profile_stat *stat; |
a2a16d6a | 881 | unsigned long long calltime; |
0706f1c4 | 882 | struct ftrace_profile *rec; |
cafb168a | 883 | unsigned long flags; |
0706f1c4 SR |
884 | |
885 | local_irq_save(flags); | |
bdffd893 | 886 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 887 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
888 | goto out; |
889 | ||
37e44bc5 SR |
890 | /* If the calltime was zero'd ignore it */ |
891 | if (!trace->calltime) | |
892 | goto out; | |
893 | ||
a2a16d6a SR |
894 | calltime = trace->rettime - trace->calltime; |
895 | ||
55577204 | 896 | if (!fgraph_graph_time) { |
a2a16d6a SR |
897 | int index; |
898 | ||
899 | index = trace->depth; | |
900 | ||
901 | /* Append this call time to the parent time to subtract */ | |
902 | if (index) | |
903 | current->ret_stack[index - 1].subtime += calltime; | |
904 | ||
905 | if (current->ret_stack[index].subtime < calltime) | |
906 | calltime -= current->ret_stack[index].subtime; | |
907 | else | |
908 | calltime = 0; | |
909 | } | |
910 | ||
cafb168a | 911 | rec = ftrace_find_profiled_func(stat, trace->func); |
e330b3bc | 912 | if (rec) { |
a2a16d6a | 913 | rec->time += calltime; |
e330b3bc CD |
914 | rec->time_squared += calltime * calltime; |
915 | } | |
a2a16d6a | 916 | |
cafb168a | 917 | out: |
0706f1c4 SR |
918 | local_irq_restore(flags); |
919 | } | |
920 | ||
921 | static int register_ftrace_profiler(void) | |
922 | { | |
923 | return register_ftrace_graph(&profile_graph_return, | |
924 | &profile_graph_entry); | |
925 | } | |
926 | ||
927 | static void unregister_ftrace_profiler(void) | |
928 | { | |
929 | unregister_ftrace_graph(); | |
930 | } | |
931 | #else | |
bd38c0e6 | 932 | static struct ftrace_ops ftrace_profile_ops __read_mostly = { |
fb9fb015 | 933 | .func = function_profile_call, |
f04f24fb | 934 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, |
33b7f99c | 935 | INIT_OPS_HASH(ftrace_profile_ops) |
bac429f0 SR |
936 | }; |
937 | ||
0706f1c4 SR |
938 | static int register_ftrace_profiler(void) |
939 | { | |
940 | return register_ftrace_function(&ftrace_profile_ops); | |
941 | } | |
942 | ||
943 | static void unregister_ftrace_profiler(void) | |
944 | { | |
945 | unregister_ftrace_function(&ftrace_profile_ops); | |
946 | } | |
947 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
948 | ||
bac429f0 SR |
949 | static ssize_t |
950 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
951 | size_t cnt, loff_t *ppos) | |
952 | { | |
953 | unsigned long val; | |
bac429f0 SR |
954 | int ret; |
955 | ||
22fe9b54 PH |
956 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
957 | if (ret) | |
bac429f0 SR |
958 | return ret; |
959 | ||
960 | val = !!val; | |
961 | ||
962 | mutex_lock(&ftrace_profile_lock); | |
963 | if (ftrace_profile_enabled ^ val) { | |
964 | if (val) { | |
493762fc SR |
965 | ret = ftrace_profile_init(); |
966 | if (ret < 0) { | |
967 | cnt = ret; | |
968 | goto out; | |
969 | } | |
970 | ||
0706f1c4 SR |
971 | ret = register_ftrace_profiler(); |
972 | if (ret < 0) { | |
973 | cnt = ret; | |
974 | goto out; | |
975 | } | |
bac429f0 SR |
976 | ftrace_profile_enabled = 1; |
977 | } else { | |
978 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
979 | /* |
980 | * unregister_ftrace_profiler calls stop_machine | |
981 | * so this acts like an synchronize_sched. | |
982 | */ | |
0706f1c4 | 983 | unregister_ftrace_profiler(); |
bac429f0 SR |
984 | } |
985 | } | |
493762fc | 986 | out: |
bac429f0 SR |
987 | mutex_unlock(&ftrace_profile_lock); |
988 | ||
cf8517cf | 989 | *ppos += cnt; |
bac429f0 SR |
990 | |
991 | return cnt; | |
992 | } | |
993 | ||
493762fc SR |
994 | static ssize_t |
995 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
996 | size_t cnt, loff_t *ppos) | |
997 | { | |
fb9fb015 | 998 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
999 | int r; |
1000 | ||
1001 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
1002 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
1003 | } | |
1004 | ||
bac429f0 SR |
1005 | static const struct file_operations ftrace_profile_fops = { |
1006 | .open = tracing_open_generic, | |
1007 | .read = ftrace_profile_read, | |
1008 | .write = ftrace_profile_write, | |
6038f373 | 1009 | .llseek = default_llseek, |
bac429f0 SR |
1010 | }; |
1011 | ||
cafb168a SR |
1012 | /* used to initialize the real stat files */ |
1013 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
1014 | .name = "functions", |
1015 | .stat_start = function_stat_start, | |
1016 | .stat_next = function_stat_next, | |
1017 | .stat_cmp = function_stat_cmp, | |
1018 | .stat_headers = function_stat_headers, | |
1019 | .stat_show = function_stat_show | |
cafb168a SR |
1020 | }; |
1021 | ||
8434dc93 | 1022 | static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
bac429f0 | 1023 | { |
cafb168a | 1024 | struct ftrace_profile_stat *stat; |
bac429f0 | 1025 | struct dentry *entry; |
cafb168a | 1026 | char *name; |
bac429f0 | 1027 | int ret; |
cafb168a SR |
1028 | int cpu; |
1029 | ||
1030 | for_each_possible_cpu(cpu) { | |
1031 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
1032 | ||
6363c6b5 | 1033 | name = kasprintf(GFP_KERNEL, "function%d", cpu); |
cafb168a SR |
1034 | if (!name) { |
1035 | /* | |
1036 | * The files created are permanent, if something happens | |
1037 | * we still do not free memory. | |
1038 | */ | |
cafb168a SR |
1039 | WARN(1, |
1040 | "Could not allocate stat file for cpu %d\n", | |
1041 | cpu); | |
1042 | return; | |
1043 | } | |
1044 | stat->stat = function_stats; | |
cafb168a SR |
1045 | stat->stat.name = name; |
1046 | ret = register_stat_tracer(&stat->stat); | |
1047 | if (ret) { | |
1048 | WARN(1, | |
1049 | "Could not register function stat for cpu %d\n", | |
1050 | cpu); | |
1051 | kfree(name); | |
1052 | return; | |
1053 | } | |
bac429f0 SR |
1054 | } |
1055 | ||
8434dc93 | 1056 | entry = tracefs_create_file("function_profile_enabled", 0644, |
bac429f0 SR |
1057 | d_tracer, NULL, &ftrace_profile_fops); |
1058 | if (!entry) | |
a395d6a7 | 1059 | pr_warn("Could not create tracefs 'function_profile_enabled' entry\n"); |
bac429f0 SR |
1060 | } |
1061 | ||
bac429f0 | 1062 | #else /* CONFIG_FUNCTION_PROFILER */ |
8434dc93 | 1063 | static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
bac429f0 SR |
1064 | { |
1065 | } | |
bac429f0 SR |
1066 | #endif /* CONFIG_FUNCTION_PROFILER */ |
1067 | ||
493762fc SR |
1068 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; |
1069 | ||
1619dc3f PA |
1070 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
1071 | static int ftrace_graph_active; | |
1072 | #else | |
1073 | # define ftrace_graph_active 0 | |
1074 | #endif | |
1075 | ||
493762fc SR |
1076 | #ifdef CONFIG_DYNAMIC_FTRACE |
1077 | ||
79922b80 SRRH |
1078 | static struct ftrace_ops *removed_ops; |
1079 | ||
e1effa01 SRRH |
1080 | /* |
1081 | * Set when doing a global update, like enabling all recs or disabling them. | |
1082 | * It is not set when just updating a single ftrace_ops. | |
1083 | */ | |
1084 | static bool update_all_ops; | |
1085 | ||
493762fc SR |
1086 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
1087 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
1088 | #endif | |
1089 | ||
1090 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; | |
1091 | ||
1092 | struct ftrace_func_probe { | |
1093 | struct hlist_node node; | |
1094 | struct ftrace_probe_ops *ops; | |
1095 | unsigned long flags; | |
1096 | unsigned long ip; | |
1097 | void *data; | |
7818b388 | 1098 | struct list_head free_list; |
493762fc SR |
1099 | }; |
1100 | ||
b448c4e3 SR |
1101 | struct ftrace_func_entry { |
1102 | struct hlist_node hlist; | |
1103 | unsigned long ip; | |
1104 | }; | |
1105 | ||
1106 | struct ftrace_hash { | |
1107 | unsigned long size_bits; | |
1108 | struct hlist_head *buckets; | |
1109 | unsigned long count; | |
07fd5515 | 1110 | struct rcu_head rcu; |
b448c4e3 SR |
1111 | }; |
1112 | ||
33dc9b12 SR |
1113 | /* |
1114 | * We make these constant because no one should touch them, | |
1115 | * but they are used as the default "empty hash", to avoid allocating | |
1116 | * it all the time. These are in a read only section such that if | |
1117 | * anyone does try to modify it, it will cause an exception. | |
1118 | */ | |
1119 | static const struct hlist_head empty_buckets[1]; | |
1120 | static const struct ftrace_hash empty_hash = { | |
1121 | .buckets = (struct hlist_head *)empty_buckets, | |
1cf41dd7 | 1122 | }; |
33dc9b12 | 1123 | #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash) |
493762fc | 1124 | |
2b499381 | 1125 | static struct ftrace_ops global_ops = { |
33b7f99c SRRH |
1126 | .func = ftrace_stub, |
1127 | .local_hash.notrace_hash = EMPTY_HASH, | |
1128 | .local_hash.filter_hash = EMPTY_HASH, | |
1129 | INIT_OPS_HASH(global_ops) | |
1130 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | | |
e3eea140 SRRH |
1131 | FTRACE_OPS_FL_INITIALIZED | |
1132 | FTRACE_OPS_FL_PID, | |
f45948e8 SR |
1133 | }; |
1134 | ||
aec0be2d SRRH |
1135 | /* |
1136 | * This is used by __kernel_text_address() to return true if the | |
0af26492 | 1137 | * address is on a dynamically allocated trampoline that would |
aec0be2d SRRH |
1138 | * not return true for either core_kernel_text() or |
1139 | * is_module_text_address(). | |
1140 | */ | |
1141 | bool is_ftrace_trampoline(unsigned long addr) | |
1142 | { | |
1143 | struct ftrace_ops *op; | |
1144 | bool ret = false; | |
1145 | ||
1146 | /* | |
1147 | * Some of the ops may be dynamically allocated, | |
1148 | * they are freed after a synchronize_sched(). | |
1149 | */ | |
1150 | preempt_disable_notrace(); | |
1151 | ||
1152 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1153 | /* | |
1154 | * This is to check for dynamically allocated trampolines. | |
1155 | * Trampolines that are in kernel text will have | |
1156 | * core_kernel_text() return true. | |
1157 | */ | |
1158 | if (op->trampoline && op->trampoline_size) | |
1159 | if (addr >= op->trampoline && | |
1160 | addr < op->trampoline + op->trampoline_size) { | |
1161 | ret = true; | |
1162 | goto out; | |
1163 | } | |
1164 | } while_for_each_ftrace_op(op); | |
1165 | ||
1166 | out: | |
1167 | preempt_enable_notrace(); | |
1168 | ||
1169 | return ret; | |
1170 | } | |
1171 | ||
493762fc SR |
1172 | struct ftrace_page { |
1173 | struct ftrace_page *next; | |
a7900875 | 1174 | struct dyn_ftrace *records; |
493762fc | 1175 | int index; |
a7900875 | 1176 | int size; |
493762fc SR |
1177 | }; |
1178 | ||
a7900875 SR |
1179 | #define ENTRY_SIZE sizeof(struct dyn_ftrace) |
1180 | #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE) | |
493762fc SR |
1181 | |
1182 | /* estimate from running different kernels */ | |
1183 | #define NR_TO_INIT 10000 | |
1184 | ||
1185 | static struct ftrace_page *ftrace_pages_start; | |
1186 | static struct ftrace_page *ftrace_pages; | |
1187 | ||
68f40969 | 1188 | static bool __always_inline ftrace_hash_empty(struct ftrace_hash *hash) |
06a51d93 SR |
1189 | { |
1190 | return !hash || !hash->count; | |
1191 | } | |
1192 | ||
b448c4e3 SR |
1193 | static struct ftrace_func_entry * |
1194 | ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
1195 | { | |
1196 | unsigned long key; | |
1197 | struct ftrace_func_entry *entry; | |
1198 | struct hlist_head *hhd; | |
b448c4e3 | 1199 | |
06a51d93 | 1200 | if (ftrace_hash_empty(hash)) |
b448c4e3 SR |
1201 | return NULL; |
1202 | ||
1203 | if (hash->size_bits > 0) | |
1204 | key = hash_long(ip, hash->size_bits); | |
1205 | else | |
1206 | key = 0; | |
1207 | ||
1208 | hhd = &hash->buckets[key]; | |
1209 | ||
1bb539ca | 1210 | hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) { |
b448c4e3 SR |
1211 | if (entry->ip == ip) |
1212 | return entry; | |
1213 | } | |
1214 | return NULL; | |
1215 | } | |
1216 | ||
33dc9b12 SR |
1217 | static void __add_hash_entry(struct ftrace_hash *hash, |
1218 | struct ftrace_func_entry *entry) | |
b448c4e3 | 1219 | { |
b448c4e3 SR |
1220 | struct hlist_head *hhd; |
1221 | unsigned long key; | |
1222 | ||
b448c4e3 | 1223 | if (hash->size_bits) |
33dc9b12 | 1224 | key = hash_long(entry->ip, hash->size_bits); |
b448c4e3 SR |
1225 | else |
1226 | key = 0; | |
1227 | ||
b448c4e3 SR |
1228 | hhd = &hash->buckets[key]; |
1229 | hlist_add_head(&entry->hlist, hhd); | |
1230 | hash->count++; | |
33dc9b12 SR |
1231 | } |
1232 | ||
1233 | static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip) | |
1234 | { | |
1235 | struct ftrace_func_entry *entry; | |
1236 | ||
1237 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1238 | if (!entry) | |
1239 | return -ENOMEM; | |
1240 | ||
1241 | entry->ip = ip; | |
1242 | __add_hash_entry(hash, entry); | |
b448c4e3 SR |
1243 | |
1244 | return 0; | |
1245 | } | |
1246 | ||
1247 | static void | |
33dc9b12 | 1248 | free_hash_entry(struct ftrace_hash *hash, |
b448c4e3 SR |
1249 | struct ftrace_func_entry *entry) |
1250 | { | |
1251 | hlist_del(&entry->hlist); | |
1252 | kfree(entry); | |
1253 | hash->count--; | |
1254 | } | |
1255 | ||
33dc9b12 SR |
1256 | static void |
1257 | remove_hash_entry(struct ftrace_hash *hash, | |
1258 | struct ftrace_func_entry *entry) | |
1259 | { | |
1260 | hlist_del(&entry->hlist); | |
1261 | hash->count--; | |
1262 | } | |
1263 | ||
b448c4e3 SR |
1264 | static void ftrace_hash_clear(struct ftrace_hash *hash) |
1265 | { | |
1266 | struct hlist_head *hhd; | |
b67bfe0d | 1267 | struct hlist_node *tn; |
b448c4e3 SR |
1268 | struct ftrace_func_entry *entry; |
1269 | int size = 1 << hash->size_bits; | |
1270 | int i; | |
1271 | ||
33dc9b12 SR |
1272 | if (!hash->count) |
1273 | return; | |
1274 | ||
b448c4e3 SR |
1275 | for (i = 0; i < size; i++) { |
1276 | hhd = &hash->buckets[i]; | |
b67bfe0d | 1277 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) |
33dc9b12 | 1278 | free_hash_entry(hash, entry); |
b448c4e3 SR |
1279 | } |
1280 | FTRACE_WARN_ON(hash->count); | |
1281 | } | |
1282 | ||
33dc9b12 SR |
1283 | static void free_ftrace_hash(struct ftrace_hash *hash) |
1284 | { | |
1285 | if (!hash || hash == EMPTY_HASH) | |
1286 | return; | |
1287 | ftrace_hash_clear(hash); | |
1288 | kfree(hash->buckets); | |
1289 | kfree(hash); | |
1290 | } | |
1291 | ||
07fd5515 SR |
1292 | static void __free_ftrace_hash_rcu(struct rcu_head *rcu) |
1293 | { | |
1294 | struct ftrace_hash *hash; | |
1295 | ||
1296 | hash = container_of(rcu, struct ftrace_hash, rcu); | |
1297 | free_ftrace_hash(hash); | |
1298 | } | |
1299 | ||
1300 | static void free_ftrace_hash_rcu(struct ftrace_hash *hash) | |
1301 | { | |
1302 | if (!hash || hash == EMPTY_HASH) | |
1303 | return; | |
1304 | call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu); | |
1305 | } | |
1306 | ||
5500fa51 JO |
1307 | void ftrace_free_filter(struct ftrace_ops *ops) |
1308 | { | |
f04f24fb | 1309 | ftrace_ops_init(ops); |
33b7f99c SRRH |
1310 | free_ftrace_hash(ops->func_hash->filter_hash); |
1311 | free_ftrace_hash(ops->func_hash->notrace_hash); | |
5500fa51 JO |
1312 | } |
1313 | ||
33dc9b12 SR |
1314 | static struct ftrace_hash *alloc_ftrace_hash(int size_bits) |
1315 | { | |
1316 | struct ftrace_hash *hash; | |
1317 | int size; | |
1318 | ||
1319 | hash = kzalloc(sizeof(*hash), GFP_KERNEL); | |
1320 | if (!hash) | |
1321 | return NULL; | |
1322 | ||
1323 | size = 1 << size_bits; | |
47b0edcb | 1324 | hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL); |
33dc9b12 SR |
1325 | |
1326 | if (!hash->buckets) { | |
1327 | kfree(hash); | |
1328 | return NULL; | |
1329 | } | |
1330 | ||
1331 | hash->size_bits = size_bits; | |
1332 | ||
1333 | return hash; | |
1334 | } | |
1335 | ||
1336 | static struct ftrace_hash * | |
1337 | alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) | |
1338 | { | |
1339 | struct ftrace_func_entry *entry; | |
1340 | struct ftrace_hash *new_hash; | |
33dc9b12 SR |
1341 | int size; |
1342 | int ret; | |
1343 | int i; | |
1344 | ||
1345 | new_hash = alloc_ftrace_hash(size_bits); | |
1346 | if (!new_hash) | |
1347 | return NULL; | |
1348 | ||
1349 | /* Empty hash? */ | |
06a51d93 | 1350 | if (ftrace_hash_empty(hash)) |
33dc9b12 SR |
1351 | return new_hash; |
1352 | ||
1353 | size = 1 << hash->size_bits; | |
1354 | for (i = 0; i < size; i++) { | |
b67bfe0d | 1355 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { |
33dc9b12 SR |
1356 | ret = add_hash_entry(new_hash, entry->ip); |
1357 | if (ret < 0) | |
1358 | goto free_hash; | |
1359 | } | |
1360 | } | |
1361 | ||
1362 | FTRACE_WARN_ON(new_hash->count != hash->count); | |
1363 | ||
1364 | return new_hash; | |
1365 | ||
1366 | free_hash: | |
1367 | free_ftrace_hash(new_hash); | |
1368 | return NULL; | |
1369 | } | |
1370 | ||
41fb61c2 | 1371 | static void |
84261912 | 1372 | ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash); |
41fb61c2 | 1373 | static void |
84261912 | 1374 | ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash); |
41fb61c2 | 1375 | |
f8b8be8a MH |
1376 | static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, |
1377 | struct ftrace_hash *new_hash); | |
1378 | ||
33dc9b12 | 1379 | static int |
41fb61c2 SR |
1380 | ftrace_hash_move(struct ftrace_ops *ops, int enable, |
1381 | struct ftrace_hash **dst, struct ftrace_hash *src) | |
33dc9b12 SR |
1382 | { |
1383 | struct ftrace_func_entry *entry; | |
b67bfe0d | 1384 | struct hlist_node *tn; |
33dc9b12 | 1385 | struct hlist_head *hhd; |
07fd5515 | 1386 | struct ftrace_hash *new_hash; |
33dc9b12 SR |
1387 | int size = src->count; |
1388 | int bits = 0; | |
f8b8be8a | 1389 | int ret; |
33dc9b12 SR |
1390 | int i; |
1391 | ||
f8b8be8a MH |
1392 | /* Reject setting notrace hash on IPMODIFY ftrace_ops */ |
1393 | if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable) | |
1394 | return -EINVAL; | |
1395 | ||
33dc9b12 SR |
1396 | /* |
1397 | * If the new source is empty, just free dst and assign it | |
1398 | * the empty_hash. | |
1399 | */ | |
1400 | if (!src->count) { | |
5c27c775 MH |
1401 | new_hash = EMPTY_HASH; |
1402 | goto update; | |
33dc9b12 SR |
1403 | } |
1404 | ||
33dc9b12 SR |
1405 | /* |
1406 | * Make the hash size about 1/2 the # found | |
1407 | */ | |
1408 | for (size /= 2; size; size >>= 1) | |
1409 | bits++; | |
1410 | ||
1411 | /* Don't allocate too much */ | |
1412 | if (bits > FTRACE_HASH_MAX_BITS) | |
1413 | bits = FTRACE_HASH_MAX_BITS; | |
1414 | ||
07fd5515 SR |
1415 | new_hash = alloc_ftrace_hash(bits); |
1416 | if (!new_hash) | |
5c27c775 | 1417 | return -ENOMEM; |
33dc9b12 SR |
1418 | |
1419 | size = 1 << src->size_bits; | |
1420 | for (i = 0; i < size; i++) { | |
1421 | hhd = &src->buckets[i]; | |
b67bfe0d | 1422 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) { |
33dc9b12 | 1423 | remove_hash_entry(src, entry); |
07fd5515 | 1424 | __add_hash_entry(new_hash, entry); |
33dc9b12 SR |
1425 | } |
1426 | } | |
1427 | ||
5c27c775 | 1428 | update: |
f8b8be8a MH |
1429 | /* Make sure this can be applied if it is IPMODIFY ftrace_ops */ |
1430 | if (enable) { | |
1431 | /* IPMODIFY should be updated only when filter_hash updating */ | |
1432 | ret = ftrace_hash_ipmodify_update(ops, new_hash); | |
1433 | if (ret < 0) { | |
1434 | free_ftrace_hash(new_hash); | |
1435 | return ret; | |
1436 | } | |
1437 | } | |
1438 | ||
5c27c775 MH |
1439 | /* |
1440 | * Remove the current set, update the hash and add | |
1441 | * them back. | |
1442 | */ | |
84261912 | 1443 | ftrace_hash_rec_disable_modify(ops, enable); |
5c27c775 | 1444 | |
07fd5515 | 1445 | rcu_assign_pointer(*dst, new_hash); |
07fd5515 | 1446 | |
84261912 | 1447 | ftrace_hash_rec_enable_modify(ops, enable); |
41fb61c2 | 1448 | |
5c27c775 | 1449 | return 0; |
33dc9b12 SR |
1450 | } |
1451 | ||
fef5aeee SRRH |
1452 | static bool hash_contains_ip(unsigned long ip, |
1453 | struct ftrace_ops_hash *hash) | |
1454 | { | |
1455 | /* | |
1456 | * The function record is a match if it exists in the filter | |
1457 | * hash and not in the notrace hash. Note, an emty hash is | |
1458 | * considered a match for the filter hash, but an empty | |
1459 | * notrace hash is considered not in the notrace hash. | |
1460 | */ | |
1461 | return (ftrace_hash_empty(hash->filter_hash) || | |
1462 | ftrace_lookup_ip(hash->filter_hash, ip)) && | |
1463 | (ftrace_hash_empty(hash->notrace_hash) || | |
1464 | !ftrace_lookup_ip(hash->notrace_hash, ip)); | |
1465 | } | |
1466 | ||
b848914c SR |
1467 | /* |
1468 | * Test the hashes for this ops to see if we want to call | |
1469 | * the ops->func or not. | |
1470 | * | |
1471 | * It's a match if the ip is in the ops->filter_hash or | |
1472 | * the filter_hash does not exist or is empty, | |
1473 | * AND | |
1474 | * the ip is not in the ops->notrace_hash. | |
cdbe61bf SR |
1475 | * |
1476 | * This needs to be called with preemption disabled as | |
1477 | * the hashes are freed with call_rcu_sched(). | |
b848914c SR |
1478 | */ |
1479 | static int | |
195a8afc | 1480 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
b848914c | 1481 | { |
fef5aeee | 1482 | struct ftrace_ops_hash hash; |
b848914c SR |
1483 | int ret; |
1484 | ||
195a8afc SRRH |
1485 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
1486 | /* | |
1487 | * There's a small race when adding ops that the ftrace handler | |
1488 | * that wants regs, may be called without them. We can not | |
1489 | * allow that handler to be called if regs is NULL. | |
1490 | */ | |
1491 | if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS)) | |
1492 | return 0; | |
1493 | #endif | |
1494 | ||
fef5aeee SRRH |
1495 | hash.filter_hash = rcu_dereference_raw_notrace(ops->func_hash->filter_hash); |
1496 | hash.notrace_hash = rcu_dereference_raw_notrace(ops->func_hash->notrace_hash); | |
b848914c | 1497 | |
fef5aeee | 1498 | if (hash_contains_ip(ip, &hash)) |
b848914c SR |
1499 | ret = 1; |
1500 | else | |
1501 | ret = 0; | |
b848914c SR |
1502 | |
1503 | return ret; | |
1504 | } | |
1505 | ||
493762fc SR |
1506 | /* |
1507 | * This is a double for. Do not use 'break' to break out of the loop, | |
1508 | * you must use a goto. | |
1509 | */ | |
1510 | #define do_for_each_ftrace_rec(pg, rec) \ | |
1511 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
1512 | int _____i; \ | |
1513 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
1514 | rec = &pg->records[_____i]; | |
1515 | ||
1516 | #define while_for_each_ftrace_rec() \ | |
1517 | } \ | |
1518 | } | |
1519 | ||
5855fead SR |
1520 | |
1521 | static int ftrace_cmp_recs(const void *a, const void *b) | |
1522 | { | |
a650e02a SR |
1523 | const struct dyn_ftrace *key = a; |
1524 | const struct dyn_ftrace *rec = b; | |
5855fead | 1525 | |
a650e02a | 1526 | if (key->flags < rec->ip) |
5855fead | 1527 | return -1; |
a650e02a SR |
1528 | if (key->ip >= rec->ip + MCOUNT_INSN_SIZE) |
1529 | return 1; | |
5855fead SR |
1530 | return 0; |
1531 | } | |
1532 | ||
f0cf973a | 1533 | static unsigned long ftrace_location_range(unsigned long start, unsigned long end) |
c88fd863 SR |
1534 | { |
1535 | struct ftrace_page *pg; | |
1536 | struct dyn_ftrace *rec; | |
5855fead | 1537 | struct dyn_ftrace key; |
c88fd863 | 1538 | |
a650e02a SR |
1539 | key.ip = start; |
1540 | key.flags = end; /* overload flags, as it is unsigned long */ | |
5855fead SR |
1541 | |
1542 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
a650e02a SR |
1543 | if (end < pg->records[0].ip || |
1544 | start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) | |
9644302e | 1545 | continue; |
5855fead SR |
1546 | rec = bsearch(&key, pg->records, pg->index, |
1547 | sizeof(struct dyn_ftrace), | |
1548 | ftrace_cmp_recs); | |
1549 | if (rec) | |
f0cf973a | 1550 | return rec->ip; |
5855fead | 1551 | } |
c88fd863 SR |
1552 | |
1553 | return 0; | |
1554 | } | |
1555 | ||
a650e02a SR |
1556 | /** |
1557 | * ftrace_location - return true if the ip giving is a traced location | |
1558 | * @ip: the instruction pointer to check | |
1559 | * | |
f0cf973a | 1560 | * Returns rec->ip if @ip given is a pointer to a ftrace location. |
a650e02a SR |
1561 | * That is, the instruction that is either a NOP or call to |
1562 | * the function tracer. It checks the ftrace internal tables to | |
1563 | * determine if the address belongs or not. | |
1564 | */ | |
f0cf973a | 1565 | unsigned long ftrace_location(unsigned long ip) |
a650e02a SR |
1566 | { |
1567 | return ftrace_location_range(ip, ip); | |
1568 | } | |
1569 | ||
1570 | /** | |
1571 | * ftrace_text_reserved - return true if range contains an ftrace location | |
1572 | * @start: start of range to search | |
1573 | * @end: end of range to search (inclusive). @end points to the last byte to check. | |
1574 | * | |
1575 | * Returns 1 if @start and @end contains a ftrace location. | |
1576 | * That is, the instruction that is either a NOP or call to | |
1577 | * the function tracer. It checks the ftrace internal tables to | |
1578 | * determine if the address belongs or not. | |
1579 | */ | |
d88471cb | 1580 | int ftrace_text_reserved(const void *start, const void *end) |
a650e02a | 1581 | { |
f0cf973a SR |
1582 | unsigned long ret; |
1583 | ||
1584 | ret = ftrace_location_range((unsigned long)start, | |
1585 | (unsigned long)end); | |
1586 | ||
1587 | return (int)!!ret; | |
a650e02a SR |
1588 | } |
1589 | ||
4fbb48cb SRRH |
1590 | /* Test if ops registered to this rec needs regs */ |
1591 | static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec) | |
1592 | { | |
1593 | struct ftrace_ops *ops; | |
1594 | bool keep_regs = false; | |
1595 | ||
1596 | for (ops = ftrace_ops_list; | |
1597 | ops != &ftrace_list_end; ops = ops->next) { | |
1598 | /* pass rec in as regs to have non-NULL val */ | |
1599 | if (ftrace_ops_test(ops, rec->ip, rec)) { | |
1600 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1601 | keep_regs = true; | |
1602 | break; | |
1603 | } | |
1604 | } | |
1605 | } | |
1606 | ||
1607 | return keep_regs; | |
1608 | } | |
1609 | ||
84b6d3e6 | 1610 | static bool __ftrace_hash_rec_update(struct ftrace_ops *ops, |
ed926f9b SR |
1611 | int filter_hash, |
1612 | bool inc) | |
1613 | { | |
1614 | struct ftrace_hash *hash; | |
1615 | struct ftrace_hash *other_hash; | |
1616 | struct ftrace_page *pg; | |
1617 | struct dyn_ftrace *rec; | |
84b6d3e6 | 1618 | bool update = false; |
ed926f9b SR |
1619 | int count = 0; |
1620 | int all = 0; | |
1621 | ||
1622 | /* Only update if the ops has been registered */ | |
1623 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
84b6d3e6 | 1624 | return false; |
ed926f9b SR |
1625 | |
1626 | /* | |
1627 | * In the filter_hash case: | |
1628 | * If the count is zero, we update all records. | |
1629 | * Otherwise we just update the items in the hash. | |
1630 | * | |
1631 | * In the notrace_hash case: | |
1632 | * We enable the update in the hash. | |
1633 | * As disabling notrace means enabling the tracing, | |
1634 | * and enabling notrace means disabling, the inc variable | |
1635 | * gets inversed. | |
1636 | */ | |
1637 | if (filter_hash) { | |
33b7f99c SRRH |
1638 | hash = ops->func_hash->filter_hash; |
1639 | other_hash = ops->func_hash->notrace_hash; | |
06a51d93 | 1640 | if (ftrace_hash_empty(hash)) |
ed926f9b SR |
1641 | all = 1; |
1642 | } else { | |
1643 | inc = !inc; | |
33b7f99c SRRH |
1644 | hash = ops->func_hash->notrace_hash; |
1645 | other_hash = ops->func_hash->filter_hash; | |
ed926f9b SR |
1646 | /* |
1647 | * If the notrace hash has no items, | |
1648 | * then there's nothing to do. | |
1649 | */ | |
06a51d93 | 1650 | if (ftrace_hash_empty(hash)) |
84b6d3e6 | 1651 | return false; |
ed926f9b SR |
1652 | } |
1653 | ||
1654 | do_for_each_ftrace_rec(pg, rec) { | |
1655 | int in_other_hash = 0; | |
1656 | int in_hash = 0; | |
1657 | int match = 0; | |
1658 | ||
b7ffffbb SRRH |
1659 | if (rec->flags & FTRACE_FL_DISABLED) |
1660 | continue; | |
1661 | ||
ed926f9b SR |
1662 | if (all) { |
1663 | /* | |
1664 | * Only the filter_hash affects all records. | |
1665 | * Update if the record is not in the notrace hash. | |
1666 | */ | |
b848914c | 1667 | if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) |
ed926f9b SR |
1668 | match = 1; |
1669 | } else { | |
06a51d93 SR |
1670 | in_hash = !!ftrace_lookup_ip(hash, rec->ip); |
1671 | in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip); | |
ed926f9b SR |
1672 | |
1673 | /* | |
19eab4a4 SRRH |
1674 | * If filter_hash is set, we want to match all functions |
1675 | * that are in the hash but not in the other hash. | |
ed926f9b | 1676 | * |
19eab4a4 SRRH |
1677 | * If filter_hash is not set, then we are decrementing. |
1678 | * That means we match anything that is in the hash | |
1679 | * and also in the other_hash. That is, we need to turn | |
1680 | * off functions in the other hash because they are disabled | |
1681 | * by this hash. | |
ed926f9b SR |
1682 | */ |
1683 | if (filter_hash && in_hash && !in_other_hash) | |
1684 | match = 1; | |
1685 | else if (!filter_hash && in_hash && | |
06a51d93 | 1686 | (in_other_hash || ftrace_hash_empty(other_hash))) |
ed926f9b SR |
1687 | match = 1; |
1688 | } | |
1689 | if (!match) | |
1690 | continue; | |
1691 | ||
1692 | if (inc) { | |
1693 | rec->flags++; | |
0376bde1 | 1694 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX)) |
84b6d3e6 | 1695 | return false; |
79922b80 SRRH |
1696 | |
1697 | /* | |
1698 | * If there's only a single callback registered to a | |
1699 | * function, and the ops has a trampoline registered | |
1700 | * for it, then we can call it directly. | |
1701 | */ | |
fef5aeee | 1702 | if (ftrace_rec_count(rec) == 1 && ops->trampoline) |
79922b80 | 1703 | rec->flags |= FTRACE_FL_TRAMP; |
fef5aeee | 1704 | else |
79922b80 SRRH |
1705 | /* |
1706 | * If we are adding another function callback | |
1707 | * to this function, and the previous had a | |
bce0b6c5 SRRH |
1708 | * custom trampoline in use, then we need to go |
1709 | * back to the default trampoline. | |
79922b80 | 1710 | */ |
fef5aeee | 1711 | rec->flags &= ~FTRACE_FL_TRAMP; |
79922b80 | 1712 | |
08f6fba5 SR |
1713 | /* |
1714 | * If any ops wants regs saved for this function | |
1715 | * then all ops will get saved regs. | |
1716 | */ | |
1717 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) | |
1718 | rec->flags |= FTRACE_FL_REGS; | |
ed926f9b | 1719 | } else { |
0376bde1 | 1720 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0)) |
84b6d3e6 | 1721 | return false; |
ed926f9b | 1722 | rec->flags--; |
79922b80 | 1723 | |
4fbb48cb SRRH |
1724 | /* |
1725 | * If the rec had REGS enabled and the ops that is | |
1726 | * being removed had REGS set, then see if there is | |
1727 | * still any ops for this record that wants regs. | |
1728 | * If not, we can stop recording them. | |
1729 | */ | |
0376bde1 | 1730 | if (ftrace_rec_count(rec) > 0 && |
4fbb48cb SRRH |
1731 | rec->flags & FTRACE_FL_REGS && |
1732 | ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1733 | if (!test_rec_ops_needs_regs(rec)) | |
1734 | rec->flags &= ~FTRACE_FL_REGS; | |
1735 | } | |
79922b80 | 1736 | |
fef5aeee SRRH |
1737 | /* |
1738 | * If the rec had TRAMP enabled, then it needs to | |
1739 | * be cleared. As TRAMP can only be enabled iff | |
1740 | * there is only a single ops attached to it. | |
1741 | * In otherwords, always disable it on decrementing. | |
1742 | * In the future, we may set it if rec count is | |
1743 | * decremented to one, and the ops that is left | |
1744 | * has a trampoline. | |
1745 | */ | |
1746 | rec->flags &= ~FTRACE_FL_TRAMP; | |
1747 | ||
79922b80 SRRH |
1748 | /* |
1749 | * flags will be cleared in ftrace_check_record() | |
1750 | * if rec count is zero. | |
1751 | */ | |
ed926f9b SR |
1752 | } |
1753 | count++; | |
84b6d3e6 JO |
1754 | |
1755 | /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */ | |
1756 | update |= ftrace_test_record(rec, 1) != FTRACE_UPDATE_IGNORE; | |
1757 | ||
ed926f9b SR |
1758 | /* Shortcut, if we handled all records, we are done. */ |
1759 | if (!all && count == hash->count) | |
84b6d3e6 | 1760 | return update; |
ed926f9b | 1761 | } while_for_each_ftrace_rec(); |
84b6d3e6 JO |
1762 | |
1763 | return update; | |
ed926f9b SR |
1764 | } |
1765 | ||
84b6d3e6 | 1766 | static bool ftrace_hash_rec_disable(struct ftrace_ops *ops, |
ed926f9b SR |
1767 | int filter_hash) |
1768 | { | |
84b6d3e6 | 1769 | return __ftrace_hash_rec_update(ops, filter_hash, 0); |
ed926f9b SR |
1770 | } |
1771 | ||
84b6d3e6 | 1772 | static bool ftrace_hash_rec_enable(struct ftrace_ops *ops, |
ed926f9b SR |
1773 | int filter_hash) |
1774 | { | |
84b6d3e6 | 1775 | return __ftrace_hash_rec_update(ops, filter_hash, 1); |
ed926f9b SR |
1776 | } |
1777 | ||
84261912 SRRH |
1778 | static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops, |
1779 | int filter_hash, int inc) | |
1780 | { | |
1781 | struct ftrace_ops *op; | |
1782 | ||
1783 | __ftrace_hash_rec_update(ops, filter_hash, inc); | |
1784 | ||
1785 | if (ops->func_hash != &global_ops.local_hash) | |
1786 | return; | |
1787 | ||
1788 | /* | |
1789 | * If the ops shares the global_ops hash, then we need to update | |
1790 | * all ops that are enabled and use this hash. | |
1791 | */ | |
1792 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1793 | /* Already done */ | |
1794 | if (op == ops) | |
1795 | continue; | |
1796 | if (op->func_hash == &global_ops.local_hash) | |
1797 | __ftrace_hash_rec_update(op, filter_hash, inc); | |
1798 | } while_for_each_ftrace_op(op); | |
1799 | } | |
1800 | ||
1801 | static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, | |
1802 | int filter_hash) | |
1803 | { | |
1804 | ftrace_hash_rec_update_modify(ops, filter_hash, 0); | |
1805 | } | |
1806 | ||
1807 | static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, | |
1808 | int filter_hash) | |
1809 | { | |
1810 | ftrace_hash_rec_update_modify(ops, filter_hash, 1); | |
1811 | } | |
1812 | ||
f8b8be8a MH |
1813 | /* |
1814 | * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK | |
1815 | * or no-needed to update, -EBUSY if it detects a conflict of the flag | |
1816 | * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs. | |
1817 | * Note that old_hash and new_hash has below meanings | |
1818 | * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected) | |
1819 | * - If the hash is EMPTY_HASH, it hits nothing | |
1820 | * - Anything else hits the recs which match the hash entries. | |
1821 | */ | |
1822 | static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops, | |
1823 | struct ftrace_hash *old_hash, | |
1824 | struct ftrace_hash *new_hash) | |
1825 | { | |
1826 | struct ftrace_page *pg; | |
1827 | struct dyn_ftrace *rec, *end = NULL; | |
1828 | int in_old, in_new; | |
1829 | ||
1830 | /* Only update if the ops has been registered */ | |
1831 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
1832 | return 0; | |
1833 | ||
1834 | if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY)) | |
1835 | return 0; | |
1836 | ||
1837 | /* | |
1838 | * Since the IPMODIFY is a very address sensitive action, we do not | |
1839 | * allow ftrace_ops to set all functions to new hash. | |
1840 | */ | |
1841 | if (!new_hash || !old_hash) | |
1842 | return -EINVAL; | |
1843 | ||
1844 | /* Update rec->flags */ | |
1845 | do_for_each_ftrace_rec(pg, rec) { | |
1846 | /* We need to update only differences of filter_hash */ | |
1847 | in_old = !!ftrace_lookup_ip(old_hash, rec->ip); | |
1848 | in_new = !!ftrace_lookup_ip(new_hash, rec->ip); | |
1849 | if (in_old == in_new) | |
1850 | continue; | |
1851 | ||
1852 | if (in_new) { | |
1853 | /* New entries must ensure no others are using it */ | |
1854 | if (rec->flags & FTRACE_FL_IPMODIFY) | |
1855 | goto rollback; | |
1856 | rec->flags |= FTRACE_FL_IPMODIFY; | |
1857 | } else /* Removed entry */ | |
1858 | rec->flags &= ~FTRACE_FL_IPMODIFY; | |
1859 | } while_for_each_ftrace_rec(); | |
1860 | ||
1861 | return 0; | |
1862 | ||
1863 | rollback: | |
1864 | end = rec; | |
1865 | ||
1866 | /* Roll back what we did above */ | |
1867 | do_for_each_ftrace_rec(pg, rec) { | |
1868 | if (rec == end) | |
1869 | goto err_out; | |
1870 | ||
1871 | in_old = !!ftrace_lookup_ip(old_hash, rec->ip); | |
1872 | in_new = !!ftrace_lookup_ip(new_hash, rec->ip); | |
1873 | if (in_old == in_new) | |
1874 | continue; | |
1875 | ||
1876 | if (in_new) | |
1877 | rec->flags &= ~FTRACE_FL_IPMODIFY; | |
1878 | else | |
1879 | rec->flags |= FTRACE_FL_IPMODIFY; | |
1880 | } while_for_each_ftrace_rec(); | |
1881 | ||
1882 | err_out: | |
1883 | return -EBUSY; | |
1884 | } | |
1885 | ||
1886 | static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops) | |
1887 | { | |
1888 | struct ftrace_hash *hash = ops->func_hash->filter_hash; | |
1889 | ||
1890 | if (ftrace_hash_empty(hash)) | |
1891 | hash = NULL; | |
1892 | ||
1893 | return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash); | |
1894 | } | |
1895 | ||
1896 | /* Disabling always succeeds */ | |
1897 | static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops) | |
1898 | { | |
1899 | struct ftrace_hash *hash = ops->func_hash->filter_hash; | |
1900 | ||
1901 | if (ftrace_hash_empty(hash)) | |
1902 | hash = NULL; | |
1903 | ||
1904 | __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH); | |
1905 | } | |
1906 | ||
1907 | static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, | |
1908 | struct ftrace_hash *new_hash) | |
1909 | { | |
1910 | struct ftrace_hash *old_hash = ops->func_hash->filter_hash; | |
1911 | ||
1912 | if (ftrace_hash_empty(old_hash)) | |
1913 | old_hash = NULL; | |
1914 | ||
1915 | if (ftrace_hash_empty(new_hash)) | |
1916 | new_hash = NULL; | |
1917 | ||
1918 | return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash); | |
1919 | } | |
1920 | ||
b05086c7 | 1921 | static void print_ip_ins(const char *fmt, const unsigned char *p) |
b17e8a37 SR |
1922 | { |
1923 | int i; | |
1924 | ||
1925 | printk(KERN_CONT "%s", fmt); | |
1926 | ||
1927 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
1928 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
1929 | } | |
1930 | ||
4fd3279b SRRH |
1931 | static struct ftrace_ops * |
1932 | ftrace_find_tramp_ops_any(struct dyn_ftrace *rec); | |
39daa7b9 SRRH |
1933 | static struct ftrace_ops * |
1934 | ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops); | |
4fd3279b | 1935 | |
02a392a0 | 1936 | enum ftrace_bug_type ftrace_bug_type; |
b05086c7 | 1937 | const void *ftrace_expected; |
02a392a0 SRRH |
1938 | |
1939 | static void print_bug_type(void) | |
1940 | { | |
1941 | switch (ftrace_bug_type) { | |
1942 | case FTRACE_BUG_UNKNOWN: | |
1943 | break; | |
1944 | case FTRACE_BUG_INIT: | |
1945 | pr_info("Initializing ftrace call sites\n"); | |
1946 | break; | |
1947 | case FTRACE_BUG_NOP: | |
1948 | pr_info("Setting ftrace call site to NOP\n"); | |
1949 | break; | |
1950 | case FTRACE_BUG_CALL: | |
1951 | pr_info("Setting ftrace call site to call ftrace function\n"); | |
1952 | break; | |
1953 | case FTRACE_BUG_UPDATE: | |
1954 | pr_info("Updating ftrace call site to call a different ftrace function\n"); | |
1955 | break; | |
1956 | } | |
1957 | } | |
1958 | ||
c88fd863 SR |
1959 | /** |
1960 | * ftrace_bug - report and shutdown function tracer | |
1961 | * @failed: The failed type (EFAULT, EINVAL, EPERM) | |
4fd3279b | 1962 | * @rec: The record that failed |
c88fd863 SR |
1963 | * |
1964 | * The arch code that enables or disables the function tracing | |
1965 | * can call ftrace_bug() when it has detected a problem in | |
1966 | * modifying the code. @failed should be one of either: | |
1967 | * EFAULT - if the problem happens on reading the @ip address | |
1968 | * EINVAL - if what is read at @ip is not what was expected | |
1969 | * EPERM - if the problem happens on writting to the @ip address | |
1970 | */ | |
4fd3279b | 1971 | void ftrace_bug(int failed, struct dyn_ftrace *rec) |
b17e8a37 | 1972 | { |
4fd3279b SRRH |
1973 | unsigned long ip = rec ? rec->ip : 0; |
1974 | ||
b17e8a37 SR |
1975 | switch (failed) { |
1976 | case -EFAULT: | |
1977 | FTRACE_WARN_ON_ONCE(1); | |
1978 | pr_info("ftrace faulted on modifying "); | |
1979 | print_ip_sym(ip); | |
1980 | break; | |
1981 | case -EINVAL: | |
1982 | FTRACE_WARN_ON_ONCE(1); | |
1983 | pr_info("ftrace failed to modify "); | |
1984 | print_ip_sym(ip); | |
b05086c7 | 1985 | print_ip_ins(" actual: ", (unsigned char *)ip); |
4fd3279b | 1986 | pr_cont("\n"); |
b05086c7 SRRH |
1987 | if (ftrace_expected) { |
1988 | print_ip_ins(" expected: ", ftrace_expected); | |
1989 | pr_cont("\n"); | |
1990 | } | |
b17e8a37 SR |
1991 | break; |
1992 | case -EPERM: | |
1993 | FTRACE_WARN_ON_ONCE(1); | |
1994 | pr_info("ftrace faulted on writing "); | |
1995 | print_ip_sym(ip); | |
1996 | break; | |
1997 | default: | |
1998 | FTRACE_WARN_ON_ONCE(1); | |
1999 | pr_info("ftrace faulted on unknown error "); | |
2000 | print_ip_sym(ip); | |
2001 | } | |
02a392a0 | 2002 | print_bug_type(); |
4fd3279b SRRH |
2003 | if (rec) { |
2004 | struct ftrace_ops *ops = NULL; | |
2005 | ||
2006 | pr_info("ftrace record flags: %lx\n", rec->flags); | |
2007 | pr_cont(" (%ld)%s", ftrace_rec_count(rec), | |
2008 | rec->flags & FTRACE_FL_REGS ? " R" : " "); | |
2009 | if (rec->flags & FTRACE_FL_TRAMP_EN) { | |
2010 | ops = ftrace_find_tramp_ops_any(rec); | |
39daa7b9 SRRH |
2011 | if (ops) { |
2012 | do { | |
2013 | pr_cont("\ttramp: %pS (%pS)", | |
2014 | (void *)ops->trampoline, | |
2015 | (void *)ops->func); | |
2016 | ops = ftrace_find_tramp_ops_next(rec, ops); | |
2017 | } while (ops); | |
2018 | } else | |
4fd3279b SRRH |
2019 | pr_cont("\ttramp: ERROR!"); |
2020 | ||
2021 | } | |
2022 | ip = ftrace_get_addr_curr(rec); | |
39daa7b9 | 2023 | pr_cont("\n expected tramp: %lx\n", ip); |
4fd3279b | 2024 | } |
b17e8a37 SR |
2025 | } |
2026 | ||
c88fd863 | 2027 | static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update) |
5072c59f | 2028 | { |
64fbcd16 | 2029 | unsigned long flag = 0UL; |
e7d3737e | 2030 | |
02a392a0 SRRH |
2031 | ftrace_bug_type = FTRACE_BUG_UNKNOWN; |
2032 | ||
b7ffffbb SRRH |
2033 | if (rec->flags & FTRACE_FL_DISABLED) |
2034 | return FTRACE_UPDATE_IGNORE; | |
2035 | ||
982c350b | 2036 | /* |
30fb6aa7 | 2037 | * If we are updating calls: |
982c350b | 2038 | * |
ed926f9b SR |
2039 | * If the record has a ref count, then we need to enable it |
2040 | * because someone is using it. | |
982c350b | 2041 | * |
ed926f9b SR |
2042 | * Otherwise we make sure its disabled. |
2043 | * | |
30fb6aa7 | 2044 | * If we are disabling calls, then disable all records that |
ed926f9b | 2045 | * are enabled. |
982c350b | 2046 | */ |
0376bde1 | 2047 | if (enable && ftrace_rec_count(rec)) |
ed926f9b | 2048 | flag = FTRACE_FL_ENABLED; |
982c350b | 2049 | |
08f6fba5 | 2050 | /* |
79922b80 SRRH |
2051 | * If enabling and the REGS flag does not match the REGS_EN, or |
2052 | * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore | |
2053 | * this record. Set flags to fail the compare against ENABLED. | |
08f6fba5 | 2054 | */ |
79922b80 SRRH |
2055 | if (flag) { |
2056 | if (!(rec->flags & FTRACE_FL_REGS) != | |
2057 | !(rec->flags & FTRACE_FL_REGS_EN)) | |
2058 | flag |= FTRACE_FL_REGS; | |
2059 | ||
2060 | if (!(rec->flags & FTRACE_FL_TRAMP) != | |
2061 | !(rec->flags & FTRACE_FL_TRAMP_EN)) | |
2062 | flag |= FTRACE_FL_TRAMP; | |
2063 | } | |
08f6fba5 | 2064 | |
64fbcd16 XG |
2065 | /* If the state of this record hasn't changed, then do nothing */ |
2066 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
c88fd863 | 2067 | return FTRACE_UPDATE_IGNORE; |
982c350b | 2068 | |
64fbcd16 | 2069 | if (flag) { |
08f6fba5 SR |
2070 | /* Save off if rec is being enabled (for return value) */ |
2071 | flag ^= rec->flags & FTRACE_FL_ENABLED; | |
2072 | ||
2073 | if (update) { | |
c88fd863 | 2074 | rec->flags |= FTRACE_FL_ENABLED; |
08f6fba5 SR |
2075 | if (flag & FTRACE_FL_REGS) { |
2076 | if (rec->flags & FTRACE_FL_REGS) | |
2077 | rec->flags |= FTRACE_FL_REGS_EN; | |
2078 | else | |
2079 | rec->flags &= ~FTRACE_FL_REGS_EN; | |
2080 | } | |
79922b80 SRRH |
2081 | if (flag & FTRACE_FL_TRAMP) { |
2082 | if (rec->flags & FTRACE_FL_TRAMP) | |
2083 | rec->flags |= FTRACE_FL_TRAMP_EN; | |
2084 | else | |
2085 | rec->flags &= ~FTRACE_FL_TRAMP_EN; | |
2086 | } | |
08f6fba5 SR |
2087 | } |
2088 | ||
2089 | /* | |
2090 | * If this record is being updated from a nop, then | |
2091 | * return UPDATE_MAKE_CALL. | |
08f6fba5 SR |
2092 | * Otherwise, |
2093 | * return UPDATE_MODIFY_CALL to tell the caller to convert | |
f1b2f2bd | 2094 | * from the save regs, to a non-save regs function or |
79922b80 | 2095 | * vice versa, or from a trampoline call. |
08f6fba5 | 2096 | */ |
02a392a0 SRRH |
2097 | if (flag & FTRACE_FL_ENABLED) { |
2098 | ftrace_bug_type = FTRACE_BUG_CALL; | |
08f6fba5 | 2099 | return FTRACE_UPDATE_MAKE_CALL; |
02a392a0 | 2100 | } |
f1b2f2bd | 2101 | |
02a392a0 | 2102 | ftrace_bug_type = FTRACE_BUG_UPDATE; |
f1b2f2bd | 2103 | return FTRACE_UPDATE_MODIFY_CALL; |
c88fd863 SR |
2104 | } |
2105 | ||
08f6fba5 SR |
2106 | if (update) { |
2107 | /* If there's no more users, clear all flags */ | |
0376bde1 | 2108 | if (!ftrace_rec_count(rec)) |
08f6fba5 SR |
2109 | rec->flags = 0; |
2110 | else | |
b24d443b SRRH |
2111 | /* |
2112 | * Just disable the record, but keep the ops TRAMP | |
2113 | * and REGS states. The _EN flags must be disabled though. | |
2114 | */ | |
2115 | rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN | | |
2116 | FTRACE_FL_REGS_EN); | |
08f6fba5 | 2117 | } |
c88fd863 | 2118 | |
02a392a0 | 2119 | ftrace_bug_type = FTRACE_BUG_NOP; |
c88fd863 SR |
2120 | return FTRACE_UPDATE_MAKE_NOP; |
2121 | } | |
2122 | ||
2123 | /** | |
2124 | * ftrace_update_record, set a record that now is tracing or not | |
2125 | * @rec: the record to update | |
2126 | * @enable: set to 1 if the record is tracing, zero to force disable | |
2127 | * | |
2128 | * The records that represent all functions that can be traced need | |
2129 | * to be updated when tracing has been enabled. | |
2130 | */ | |
2131 | int ftrace_update_record(struct dyn_ftrace *rec, int enable) | |
2132 | { | |
2133 | return ftrace_check_record(rec, enable, 1); | |
2134 | } | |
2135 | ||
2136 | /** | |
2137 | * ftrace_test_record, check if the record has been enabled or not | |
2138 | * @rec: the record to test | |
2139 | * @enable: set to 1 to check if enabled, 0 if it is disabled | |
2140 | * | |
2141 | * The arch code may need to test if a record is already set to | |
2142 | * tracing to determine how to modify the function code that it | |
2143 | * represents. | |
2144 | */ | |
2145 | int ftrace_test_record(struct dyn_ftrace *rec, int enable) | |
2146 | { | |
2147 | return ftrace_check_record(rec, enable, 0); | |
2148 | } | |
2149 | ||
5fecaa04 SRRH |
2150 | static struct ftrace_ops * |
2151 | ftrace_find_tramp_ops_any(struct dyn_ftrace *rec) | |
2152 | { | |
2153 | struct ftrace_ops *op; | |
fef5aeee | 2154 | unsigned long ip = rec->ip; |
5fecaa04 SRRH |
2155 | |
2156 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2157 | ||
2158 | if (!op->trampoline) | |
2159 | continue; | |
2160 | ||
fef5aeee | 2161 | if (hash_contains_ip(ip, op->func_hash)) |
5fecaa04 SRRH |
2162 | return op; |
2163 | } while_for_each_ftrace_op(op); | |
2164 | ||
2165 | return NULL; | |
2166 | } | |
2167 | ||
39daa7b9 SRRH |
2168 | static struct ftrace_ops * |
2169 | ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, | |
2170 | struct ftrace_ops *op) | |
2171 | { | |
2172 | unsigned long ip = rec->ip; | |
2173 | ||
2174 | while_for_each_ftrace_op(op) { | |
2175 | ||
2176 | if (!op->trampoline) | |
2177 | continue; | |
2178 | ||
2179 | if (hash_contains_ip(ip, op->func_hash)) | |
2180 | return op; | |
2181 | } | |
2182 | ||
2183 | return NULL; | |
2184 | } | |
2185 | ||
79922b80 SRRH |
2186 | static struct ftrace_ops * |
2187 | ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec) | |
2188 | { | |
2189 | struct ftrace_ops *op; | |
fef5aeee | 2190 | unsigned long ip = rec->ip; |
79922b80 | 2191 | |
fef5aeee SRRH |
2192 | /* |
2193 | * Need to check removed ops first. | |
2194 | * If they are being removed, and this rec has a tramp, | |
2195 | * and this rec is in the ops list, then it would be the | |
2196 | * one with the tramp. | |
2197 | */ | |
2198 | if (removed_ops) { | |
2199 | if (hash_contains_ip(ip, &removed_ops->old_hash)) | |
79922b80 SRRH |
2200 | return removed_ops; |
2201 | } | |
2202 | ||
fef5aeee SRRH |
2203 | /* |
2204 | * Need to find the current trampoline for a rec. | |
2205 | * Now, a trampoline is only attached to a rec if there | |
2206 | * was a single 'ops' attached to it. But this can be called | |
2207 | * when we are adding another op to the rec or removing the | |
2208 | * current one. Thus, if the op is being added, we can | |
2209 | * ignore it because it hasn't attached itself to the rec | |
4fc40904 SRRH |
2210 | * yet. |
2211 | * | |
2212 | * If an ops is being modified (hooking to different functions) | |
2213 | * then we don't care about the new functions that are being | |
2214 | * added, just the old ones (that are probably being removed). | |
2215 | * | |
2216 | * If we are adding an ops to a function that already is using | |
2217 | * a trampoline, it needs to be removed (trampolines are only | |
2218 | * for single ops connected), then an ops that is not being | |
2219 | * modified also needs to be checked. | |
fef5aeee | 2220 | */ |
79922b80 | 2221 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
fef5aeee SRRH |
2222 | |
2223 | if (!op->trampoline) | |
2224 | continue; | |
2225 | ||
2226 | /* | |
2227 | * If the ops is being added, it hasn't gotten to | |
2228 | * the point to be removed from this tree yet. | |
2229 | */ | |
2230 | if (op->flags & FTRACE_OPS_FL_ADDING) | |
79922b80 SRRH |
2231 | continue; |
2232 | ||
4fc40904 | 2233 | |
fef5aeee | 2234 | /* |
4fc40904 SRRH |
2235 | * If the ops is being modified and is in the old |
2236 | * hash, then it is probably being removed from this | |
2237 | * function. | |
fef5aeee | 2238 | */ |
fef5aeee SRRH |
2239 | if ((op->flags & FTRACE_OPS_FL_MODIFYING) && |
2240 | hash_contains_ip(ip, &op->old_hash)) | |
79922b80 | 2241 | return op; |
4fc40904 SRRH |
2242 | /* |
2243 | * If the ops is not being added or modified, and it's | |
2244 | * in its normal filter hash, then this must be the one | |
2245 | * we want! | |
2246 | */ | |
2247 | if (!(op->flags & FTRACE_OPS_FL_MODIFYING) && | |
2248 | hash_contains_ip(ip, op->func_hash)) | |
2249 | return op; | |
79922b80 SRRH |
2250 | |
2251 | } while_for_each_ftrace_op(op); | |
2252 | ||
2253 | return NULL; | |
2254 | } | |
2255 | ||
2256 | static struct ftrace_ops * | |
2257 | ftrace_find_tramp_ops_new(struct dyn_ftrace *rec) | |
2258 | { | |
2259 | struct ftrace_ops *op; | |
fef5aeee | 2260 | unsigned long ip = rec->ip; |
79922b80 SRRH |
2261 | |
2262 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2263 | /* pass rec in as regs to have non-NULL val */ | |
fef5aeee | 2264 | if (hash_contains_ip(ip, op->func_hash)) |
79922b80 SRRH |
2265 | return op; |
2266 | } while_for_each_ftrace_op(op); | |
2267 | ||
2268 | return NULL; | |
2269 | } | |
2270 | ||
7413af1f SRRH |
2271 | /** |
2272 | * ftrace_get_addr_new - Get the call address to set to | |
2273 | * @rec: The ftrace record descriptor | |
2274 | * | |
2275 | * If the record has the FTRACE_FL_REGS set, that means that it | |
2276 | * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS | |
2277 | * is not not set, then it wants to convert to the normal callback. | |
2278 | * | |
2279 | * Returns the address of the trampoline to set to | |
2280 | */ | |
2281 | unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec) | |
2282 | { | |
79922b80 SRRH |
2283 | struct ftrace_ops *ops; |
2284 | ||
2285 | /* Trampolines take precedence over regs */ | |
2286 | if (rec->flags & FTRACE_FL_TRAMP) { | |
2287 | ops = ftrace_find_tramp_ops_new(rec); | |
2288 | if (FTRACE_WARN_ON(!ops || !ops->trampoline)) { | |
bce0b6c5 SRRH |
2289 | pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n", |
2290 | (void *)rec->ip, (void *)rec->ip, rec->flags); | |
79922b80 SRRH |
2291 | /* Ftrace is shutting down, return anything */ |
2292 | return (unsigned long)FTRACE_ADDR; | |
2293 | } | |
2294 | return ops->trampoline; | |
2295 | } | |
2296 | ||
7413af1f SRRH |
2297 | if (rec->flags & FTRACE_FL_REGS) |
2298 | return (unsigned long)FTRACE_REGS_ADDR; | |
2299 | else | |
2300 | return (unsigned long)FTRACE_ADDR; | |
2301 | } | |
2302 | ||
2303 | /** | |
2304 | * ftrace_get_addr_curr - Get the call address that is already there | |
2305 | * @rec: The ftrace record descriptor | |
2306 | * | |
2307 | * The FTRACE_FL_REGS_EN is set when the record already points to | |
2308 | * a function that saves all the regs. Basically the '_EN' version | |
2309 | * represents the current state of the function. | |
2310 | * | |
2311 | * Returns the address of the trampoline that is currently being called | |
2312 | */ | |
2313 | unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec) | |
2314 | { | |
79922b80 SRRH |
2315 | struct ftrace_ops *ops; |
2316 | ||
2317 | /* Trampolines take precedence over regs */ | |
2318 | if (rec->flags & FTRACE_FL_TRAMP_EN) { | |
2319 | ops = ftrace_find_tramp_ops_curr(rec); | |
2320 | if (FTRACE_WARN_ON(!ops)) { | |
a395d6a7 JP |
2321 | pr_warn("Bad trampoline accounting at: %p (%pS)\n", |
2322 | (void *)rec->ip, (void *)rec->ip); | |
79922b80 SRRH |
2323 | /* Ftrace is shutting down, return anything */ |
2324 | return (unsigned long)FTRACE_ADDR; | |
2325 | } | |
2326 | return ops->trampoline; | |
2327 | } | |
2328 | ||
7413af1f SRRH |
2329 | if (rec->flags & FTRACE_FL_REGS_EN) |
2330 | return (unsigned long)FTRACE_REGS_ADDR; | |
2331 | else | |
2332 | return (unsigned long)FTRACE_ADDR; | |
2333 | } | |
2334 | ||
c88fd863 SR |
2335 | static int |
2336 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) | |
2337 | { | |
08f6fba5 | 2338 | unsigned long ftrace_old_addr; |
c88fd863 SR |
2339 | unsigned long ftrace_addr; |
2340 | int ret; | |
2341 | ||
7c0868e0 | 2342 | ftrace_addr = ftrace_get_addr_new(rec); |
c88fd863 | 2343 | |
7c0868e0 SRRH |
2344 | /* This needs to be done before we call ftrace_update_record */ |
2345 | ftrace_old_addr = ftrace_get_addr_curr(rec); | |
2346 | ||
2347 | ret = ftrace_update_record(rec, enable); | |
08f6fba5 | 2348 | |
02a392a0 SRRH |
2349 | ftrace_bug_type = FTRACE_BUG_UNKNOWN; |
2350 | ||
c88fd863 SR |
2351 | switch (ret) { |
2352 | case FTRACE_UPDATE_IGNORE: | |
2353 | return 0; | |
2354 | ||
2355 | case FTRACE_UPDATE_MAKE_CALL: | |
02a392a0 | 2356 | ftrace_bug_type = FTRACE_BUG_CALL; |
64fbcd16 | 2357 | return ftrace_make_call(rec, ftrace_addr); |
c88fd863 SR |
2358 | |
2359 | case FTRACE_UPDATE_MAKE_NOP: | |
02a392a0 | 2360 | ftrace_bug_type = FTRACE_BUG_NOP; |
39b5552c | 2361 | return ftrace_make_nop(NULL, rec, ftrace_old_addr); |
08f6fba5 | 2362 | |
08f6fba5 | 2363 | case FTRACE_UPDATE_MODIFY_CALL: |
02a392a0 | 2364 | ftrace_bug_type = FTRACE_BUG_UPDATE; |
08f6fba5 | 2365 | return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr); |
5072c59f SR |
2366 | } |
2367 | ||
c88fd863 | 2368 | return -1; /* unknow ftrace bug */ |
5072c59f SR |
2369 | } |
2370 | ||
e4f5d544 | 2371 | void __weak ftrace_replace_code(int enable) |
3c1720f0 | 2372 | { |
3c1720f0 SR |
2373 | struct dyn_ftrace *rec; |
2374 | struct ftrace_page *pg; | |
6a24a244 | 2375 | int failed; |
3c1720f0 | 2376 | |
45a4a237 SR |
2377 | if (unlikely(ftrace_disabled)) |
2378 | return; | |
2379 | ||
265c831c | 2380 | do_for_each_ftrace_rec(pg, rec) { |
e4f5d544 | 2381 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 2382 | if (failed) { |
4fd3279b | 2383 | ftrace_bug(failed, rec); |
3279ba37 SR |
2384 | /* Stop processing */ |
2385 | return; | |
3c1720f0 | 2386 | } |
265c831c | 2387 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
2388 | } |
2389 | ||
c88fd863 SR |
2390 | struct ftrace_rec_iter { |
2391 | struct ftrace_page *pg; | |
2392 | int index; | |
2393 | }; | |
2394 | ||
2395 | /** | |
2396 | * ftrace_rec_iter_start, start up iterating over traced functions | |
2397 | * | |
2398 | * Returns an iterator handle that is used to iterate over all | |
2399 | * the records that represent address locations where functions | |
2400 | * are traced. | |
2401 | * | |
2402 | * May return NULL if no records are available. | |
2403 | */ | |
2404 | struct ftrace_rec_iter *ftrace_rec_iter_start(void) | |
2405 | { | |
2406 | /* | |
2407 | * We only use a single iterator. | |
2408 | * Protected by the ftrace_lock mutex. | |
2409 | */ | |
2410 | static struct ftrace_rec_iter ftrace_rec_iter; | |
2411 | struct ftrace_rec_iter *iter = &ftrace_rec_iter; | |
2412 | ||
2413 | iter->pg = ftrace_pages_start; | |
2414 | iter->index = 0; | |
2415 | ||
2416 | /* Could have empty pages */ | |
2417 | while (iter->pg && !iter->pg->index) | |
2418 | iter->pg = iter->pg->next; | |
2419 | ||
2420 | if (!iter->pg) | |
2421 | return NULL; | |
2422 | ||
2423 | return iter; | |
2424 | } | |
2425 | ||
2426 | /** | |
2427 | * ftrace_rec_iter_next, get the next record to process. | |
2428 | * @iter: The handle to the iterator. | |
2429 | * | |
2430 | * Returns the next iterator after the given iterator @iter. | |
2431 | */ | |
2432 | struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) | |
2433 | { | |
2434 | iter->index++; | |
2435 | ||
2436 | if (iter->index >= iter->pg->index) { | |
2437 | iter->pg = iter->pg->next; | |
2438 | iter->index = 0; | |
2439 | ||
2440 | /* Could have empty pages */ | |
2441 | while (iter->pg && !iter->pg->index) | |
2442 | iter->pg = iter->pg->next; | |
2443 | } | |
2444 | ||
2445 | if (!iter->pg) | |
2446 | return NULL; | |
2447 | ||
2448 | return iter; | |
2449 | } | |
2450 | ||
2451 | /** | |
2452 | * ftrace_rec_iter_record, get the record at the iterator location | |
2453 | * @iter: The current iterator location | |
2454 | * | |
2455 | * Returns the record that the current @iter is at. | |
2456 | */ | |
2457 | struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) | |
2458 | { | |
2459 | return &iter->pg->records[iter->index]; | |
2460 | } | |
2461 | ||
492a7ea5 | 2462 | static int |
31e88909 | 2463 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 | 2464 | { |
593eb8a2 | 2465 | int ret; |
3c1720f0 | 2466 | |
45a4a237 SR |
2467 | if (unlikely(ftrace_disabled)) |
2468 | return 0; | |
2469 | ||
25aac9dc | 2470 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 2471 | if (ret) { |
02a392a0 | 2472 | ftrace_bug_type = FTRACE_BUG_INIT; |
4fd3279b | 2473 | ftrace_bug(ret, rec); |
492a7ea5 | 2474 | return 0; |
37ad5084 | 2475 | } |
492a7ea5 | 2476 | return 1; |
3c1720f0 SR |
2477 | } |
2478 | ||
000ab691 SR |
2479 | /* |
2480 | * archs can override this function if they must do something | |
2481 | * before the modifying code is performed. | |
2482 | */ | |
2483 | int __weak ftrace_arch_code_modify_prepare(void) | |
2484 | { | |
2485 | return 0; | |
2486 | } | |
2487 | ||
2488 | /* | |
2489 | * archs can override this function if they must do something | |
2490 | * after the modifying code is performed. | |
2491 | */ | |
2492 | int __weak ftrace_arch_code_modify_post_process(void) | |
2493 | { | |
2494 | return 0; | |
2495 | } | |
2496 | ||
8ed3e2cf | 2497 | void ftrace_modify_all_code(int command) |
3d083395 | 2498 | { |
59338f75 | 2499 | int update = command & FTRACE_UPDATE_TRACE_FUNC; |
cd21067f | 2500 | int err = 0; |
59338f75 SRRH |
2501 | |
2502 | /* | |
2503 | * If the ftrace_caller calls a ftrace_ops func directly, | |
2504 | * we need to make sure that it only traces functions it | |
2505 | * expects to trace. When doing the switch of functions, | |
2506 | * we need to update to the ftrace_ops_list_func first | |
2507 | * before the transition between old and new calls are set, | |
2508 | * as the ftrace_ops_list_func will check the ops hashes | |
2509 | * to make sure the ops are having the right functions | |
2510 | * traced. | |
2511 | */ | |
cd21067f PM |
2512 | if (update) { |
2513 | err = ftrace_update_ftrace_func(ftrace_ops_list_func); | |
2514 | if (FTRACE_WARN_ON(err)) | |
2515 | return; | |
2516 | } | |
59338f75 | 2517 | |
8ed3e2cf | 2518 | if (command & FTRACE_UPDATE_CALLS) |
d61f82d0 | 2519 | ftrace_replace_code(1); |
8ed3e2cf | 2520 | else if (command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
2521 | ftrace_replace_code(0); |
2522 | ||
405e1d83 SRRH |
2523 | if (update && ftrace_trace_function != ftrace_ops_list_func) { |
2524 | function_trace_op = set_function_trace_op; | |
2525 | smp_wmb(); | |
2526 | /* If irqs are disabled, we are in stop machine */ | |
2527 | if (!irqs_disabled()) | |
2528 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
cd21067f PM |
2529 | err = ftrace_update_ftrace_func(ftrace_trace_function); |
2530 | if (FTRACE_WARN_ON(err)) | |
2531 | return; | |
405e1d83 | 2532 | } |
d61f82d0 | 2533 | |
8ed3e2cf | 2534 | if (command & FTRACE_START_FUNC_RET) |
cd21067f | 2535 | err = ftrace_enable_ftrace_graph_caller(); |
8ed3e2cf | 2536 | else if (command & FTRACE_STOP_FUNC_RET) |
cd21067f PM |
2537 | err = ftrace_disable_ftrace_graph_caller(); |
2538 | FTRACE_WARN_ON(err); | |
8ed3e2cf SR |
2539 | } |
2540 | ||
2541 | static int __ftrace_modify_code(void *data) | |
2542 | { | |
2543 | int *command = data; | |
2544 | ||
2545 | ftrace_modify_all_code(*command); | |
5a45cfe1 | 2546 | |
d61f82d0 | 2547 | return 0; |
3d083395 SR |
2548 | } |
2549 | ||
c88fd863 SR |
2550 | /** |
2551 | * ftrace_run_stop_machine, go back to the stop machine method | |
2552 | * @command: The command to tell ftrace what to do | |
2553 | * | |
2554 | * If an arch needs to fall back to the stop machine method, the | |
2555 | * it can call this function. | |
2556 | */ | |
2557 | void ftrace_run_stop_machine(int command) | |
2558 | { | |
2559 | stop_machine(__ftrace_modify_code, &command, NULL); | |
2560 | } | |
2561 | ||
2562 | /** | |
2563 | * arch_ftrace_update_code, modify the code to trace or not trace | |
2564 | * @command: The command that needs to be done | |
2565 | * | |
2566 | * Archs can override this function if it does not need to | |
2567 | * run stop_machine() to modify code. | |
2568 | */ | |
2569 | void __weak arch_ftrace_update_code(int command) | |
2570 | { | |
2571 | ftrace_run_stop_machine(command); | |
2572 | } | |
2573 | ||
e309b41d | 2574 | static void ftrace_run_update_code(int command) |
3d083395 | 2575 | { |
000ab691 SR |
2576 | int ret; |
2577 | ||
2578 | ret = ftrace_arch_code_modify_prepare(); | |
2579 | FTRACE_WARN_ON(ret); | |
2580 | if (ret) | |
2581 | return; | |
2582 | ||
c88fd863 SR |
2583 | /* |
2584 | * By default we use stop_machine() to modify the code. | |
2585 | * But archs can do what ever they want as long as it | |
2586 | * is safe. The stop_machine() is the safest, but also | |
2587 | * produces the most overhead. | |
2588 | */ | |
2589 | arch_ftrace_update_code(command); | |
2590 | ||
000ab691 SR |
2591 | ret = ftrace_arch_code_modify_post_process(); |
2592 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
2593 | } |
2594 | ||
8252ecf3 | 2595 | static void ftrace_run_modify_code(struct ftrace_ops *ops, int command, |
7485058e | 2596 | struct ftrace_ops_hash *old_hash) |
e1effa01 SRRH |
2597 | { |
2598 | ops->flags |= FTRACE_OPS_FL_MODIFYING; | |
7485058e SRRH |
2599 | ops->old_hash.filter_hash = old_hash->filter_hash; |
2600 | ops->old_hash.notrace_hash = old_hash->notrace_hash; | |
e1effa01 | 2601 | ftrace_run_update_code(command); |
8252ecf3 | 2602 | ops->old_hash.filter_hash = NULL; |
7485058e | 2603 | ops->old_hash.notrace_hash = NULL; |
e1effa01 SRRH |
2604 | ops->flags &= ~FTRACE_OPS_FL_MODIFYING; |
2605 | } | |
2606 | ||
d61f82d0 | 2607 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 2608 | static int ftrace_start_up; |
df4fc315 | 2609 | |
12cce594 SRRH |
2610 | void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops) |
2611 | { | |
2612 | } | |
2613 | ||
ba27f2bc | 2614 | static void per_cpu_ops_free(struct ftrace_ops *ops) |
db0fbadc JS |
2615 | { |
2616 | free_percpu(ops->disabled); | |
2617 | } | |
2618 | ||
df4fc315 SR |
2619 | static void ftrace_startup_enable(int command) |
2620 | { | |
2621 | if (saved_ftrace_func != ftrace_trace_function) { | |
2622 | saved_ftrace_func = ftrace_trace_function; | |
2623 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2624 | } | |
2625 | ||
2626 | if (!command || !ftrace_enabled) | |
2627 | return; | |
2628 | ||
2629 | ftrace_run_update_code(command); | |
2630 | } | |
d61f82d0 | 2631 | |
e1effa01 SRRH |
2632 | static void ftrace_startup_all(int command) |
2633 | { | |
2634 | update_all_ops = true; | |
2635 | ftrace_startup_enable(command); | |
2636 | update_all_ops = false; | |
2637 | } | |
2638 | ||
a1cd6173 | 2639 | static int ftrace_startup(struct ftrace_ops *ops, int command) |
3d083395 | 2640 | { |
8a56d776 | 2641 | int ret; |
b848914c | 2642 | |
4eebcc81 | 2643 | if (unlikely(ftrace_disabled)) |
a1cd6173 | 2644 | return -ENODEV; |
4eebcc81 | 2645 | |
8a56d776 SRRH |
2646 | ret = __register_ftrace_function(ops); |
2647 | if (ret) | |
2648 | return ret; | |
2649 | ||
60a7ecf4 | 2650 | ftrace_start_up++; |
d61f82d0 | 2651 | |
e1effa01 SRRH |
2652 | /* |
2653 | * Note that ftrace probes uses this to start up | |
2654 | * and modify functions it will probe. But we still | |
2655 | * set the ADDING flag for modification, as probes | |
2656 | * do not have trampolines. If they add them in the | |
2657 | * future, then the probes will need to distinguish | |
2658 | * between adding and updating probes. | |
2659 | */ | |
2660 | ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING; | |
66209a5b | 2661 | |
f8b8be8a MH |
2662 | ret = ftrace_hash_ipmodify_enable(ops); |
2663 | if (ret < 0) { | |
2664 | /* Rollback registration process */ | |
2665 | __unregister_ftrace_function(ops); | |
2666 | ftrace_start_up--; | |
2667 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; | |
2668 | return ret; | |
2669 | } | |
2670 | ||
7f50d06b JO |
2671 | if (ftrace_hash_rec_enable(ops, 1)) |
2672 | command |= FTRACE_UPDATE_CALLS; | |
ed926f9b | 2673 | |
df4fc315 | 2674 | ftrace_startup_enable(command); |
a1cd6173 | 2675 | |
e1effa01 SRRH |
2676 | ops->flags &= ~FTRACE_OPS_FL_ADDING; |
2677 | ||
a1cd6173 | 2678 | return 0; |
3d083395 SR |
2679 | } |
2680 | ||
8a56d776 | 2681 | static int ftrace_shutdown(struct ftrace_ops *ops, int command) |
3d083395 | 2682 | { |
8a56d776 | 2683 | int ret; |
b848914c | 2684 | |
4eebcc81 | 2685 | if (unlikely(ftrace_disabled)) |
8a56d776 SRRH |
2686 | return -ENODEV; |
2687 | ||
2688 | ret = __unregister_ftrace_function(ops); | |
2689 | if (ret) | |
2690 | return ret; | |
4eebcc81 | 2691 | |
60a7ecf4 | 2692 | ftrace_start_up--; |
9ea1a153 FW |
2693 | /* |
2694 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
2695 | * critical but the ftrace_call callers may be never nopped again after | |
2696 | * further ftrace uses. | |
2697 | */ | |
2698 | WARN_ON_ONCE(ftrace_start_up < 0); | |
2699 | ||
f8b8be8a MH |
2700 | /* Disabling ipmodify never fails */ |
2701 | ftrace_hash_ipmodify_disable(ops); | |
ed926f9b | 2702 | |
7f50d06b JO |
2703 | if (ftrace_hash_rec_disable(ops, 1)) |
2704 | command |= FTRACE_UPDATE_CALLS; | |
b848914c | 2705 | |
7f50d06b | 2706 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
3d083395 | 2707 | |
d61f82d0 SR |
2708 | if (saved_ftrace_func != ftrace_trace_function) { |
2709 | saved_ftrace_func = ftrace_trace_function; | |
2710 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2711 | } | |
3d083395 | 2712 | |
a4c35ed2 SRRH |
2713 | if (!command || !ftrace_enabled) { |
2714 | /* | |
ba27f2bc | 2715 | * If these are per_cpu ops, they still need their |
a4c35ed2 SRRH |
2716 | * per_cpu field freed. Since, function tracing is |
2717 | * not currently active, we can just free them | |
2718 | * without synchronizing all CPUs. | |
2719 | */ | |
ba27f2bc SRRH |
2720 | if (ops->flags & FTRACE_OPS_FL_PER_CPU) |
2721 | per_cpu_ops_free(ops); | |
8a56d776 | 2722 | return 0; |
a4c35ed2 | 2723 | } |
d61f82d0 | 2724 | |
79922b80 SRRH |
2725 | /* |
2726 | * If the ops uses a trampoline, then it needs to be | |
2727 | * tested first on update. | |
2728 | */ | |
e1effa01 | 2729 | ops->flags |= FTRACE_OPS_FL_REMOVING; |
79922b80 SRRH |
2730 | removed_ops = ops; |
2731 | ||
fef5aeee SRRH |
2732 | /* The trampoline logic checks the old hashes */ |
2733 | ops->old_hash.filter_hash = ops->func_hash->filter_hash; | |
2734 | ops->old_hash.notrace_hash = ops->func_hash->notrace_hash; | |
2735 | ||
d61f82d0 | 2736 | ftrace_run_update_code(command); |
a4c35ed2 | 2737 | |
84bde62c SRRH |
2738 | /* |
2739 | * If there's no more ops registered with ftrace, run a | |
2740 | * sanity check to make sure all rec flags are cleared. | |
2741 | */ | |
2742 | if (ftrace_ops_list == &ftrace_list_end) { | |
2743 | struct ftrace_page *pg; | |
2744 | struct dyn_ftrace *rec; | |
2745 | ||
2746 | do_for_each_ftrace_rec(pg, rec) { | |
2747 | if (FTRACE_WARN_ON_ONCE(rec->flags)) | |
2748 | pr_warn(" %pS flags:%lx\n", | |
2749 | (void *)rec->ip, rec->flags); | |
2750 | } while_for_each_ftrace_rec(); | |
2751 | } | |
2752 | ||
fef5aeee SRRH |
2753 | ops->old_hash.filter_hash = NULL; |
2754 | ops->old_hash.notrace_hash = NULL; | |
2755 | ||
2756 | removed_ops = NULL; | |
e1effa01 | 2757 | ops->flags &= ~FTRACE_OPS_FL_REMOVING; |
79922b80 | 2758 | |
a4c35ed2 SRRH |
2759 | /* |
2760 | * Dynamic ops may be freed, we must make sure that all | |
2761 | * callers are done before leaving this function. | |
ba27f2bc | 2762 | * The same goes for freeing the per_cpu data of the per_cpu |
a4c35ed2 SRRH |
2763 | * ops. |
2764 | * | |
2765 | * Again, normal synchronize_sched() is not good enough. | |
2766 | * We need to do a hard force of sched synchronization. | |
2767 | * This is because we use preempt_disable() to do RCU, but | |
2768 | * the function tracers can be called where RCU is not watching | |
2769 | * (like before user_exit()). We can not rely on the RCU | |
2770 | * infrastructure to do the synchronization, thus we must do it | |
2771 | * ourselves. | |
2772 | */ | |
ba27f2bc | 2773 | if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_PER_CPU)) { |
a4c35ed2 SRRH |
2774 | schedule_on_each_cpu(ftrace_sync); |
2775 | ||
12cce594 SRRH |
2776 | arch_ftrace_trampoline_free(ops); |
2777 | ||
ba27f2bc SRRH |
2778 | if (ops->flags & FTRACE_OPS_FL_PER_CPU) |
2779 | per_cpu_ops_free(ops); | |
a4c35ed2 SRRH |
2780 | } |
2781 | ||
8a56d776 | 2782 | return 0; |
3d083395 SR |
2783 | } |
2784 | ||
e309b41d | 2785 | static void ftrace_startup_sysctl(void) |
b0fc494f | 2786 | { |
1619dc3f PA |
2787 | int command; |
2788 | ||
4eebcc81 SR |
2789 | if (unlikely(ftrace_disabled)) |
2790 | return; | |
2791 | ||
d61f82d0 SR |
2792 | /* Force update next time */ |
2793 | saved_ftrace_func = NULL; | |
60a7ecf4 | 2794 | /* ftrace_start_up is true if we want ftrace running */ |
1619dc3f PA |
2795 | if (ftrace_start_up) { |
2796 | command = FTRACE_UPDATE_CALLS; | |
2797 | if (ftrace_graph_active) | |
2798 | command |= FTRACE_START_FUNC_RET; | |
524a3868 | 2799 | ftrace_startup_enable(command); |
1619dc3f | 2800 | } |
b0fc494f SR |
2801 | } |
2802 | ||
e309b41d | 2803 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 2804 | { |
1619dc3f PA |
2805 | int command; |
2806 | ||
4eebcc81 SR |
2807 | if (unlikely(ftrace_disabled)) |
2808 | return; | |
2809 | ||
60a7ecf4 | 2810 | /* ftrace_start_up is true if ftrace is running */ |
1619dc3f PA |
2811 | if (ftrace_start_up) { |
2812 | command = FTRACE_DISABLE_CALLS; | |
2813 | if (ftrace_graph_active) | |
2814 | command |= FTRACE_STOP_FUNC_RET; | |
2815 | ftrace_run_update_code(command); | |
2816 | } | |
b0fc494f SR |
2817 | } |
2818 | ||
3d083395 | 2819 | static cycle_t ftrace_update_time; |
3d083395 SR |
2820 | unsigned long ftrace_update_tot_cnt; |
2821 | ||
8c4f3c3f | 2822 | static inline int ops_traces_mod(struct ftrace_ops *ops) |
f7bc8b61 | 2823 | { |
8c4f3c3f SRRH |
2824 | /* |
2825 | * Filter_hash being empty will default to trace module. | |
2826 | * But notrace hash requires a test of individual module functions. | |
2827 | */ | |
33b7f99c SRRH |
2828 | return ftrace_hash_empty(ops->func_hash->filter_hash) && |
2829 | ftrace_hash_empty(ops->func_hash->notrace_hash); | |
8c4f3c3f SRRH |
2830 | } |
2831 | ||
2832 | /* | |
2833 | * Check if the current ops references the record. | |
2834 | * | |
2835 | * If the ops traces all functions, then it was already accounted for. | |
2836 | * If the ops does not trace the current record function, skip it. | |
2837 | * If the ops ignores the function via notrace filter, skip it. | |
2838 | */ | |
2839 | static inline bool | |
2840 | ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec) | |
2841 | { | |
2842 | /* If ops isn't enabled, ignore it */ | |
2843 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
2844 | return 0; | |
2845 | ||
b7ffffbb | 2846 | /* If ops traces all then it includes this function */ |
8c4f3c3f | 2847 | if (ops_traces_mod(ops)) |
b7ffffbb | 2848 | return 1; |
8c4f3c3f SRRH |
2849 | |
2850 | /* The function must be in the filter */ | |
33b7f99c SRRH |
2851 | if (!ftrace_hash_empty(ops->func_hash->filter_hash) && |
2852 | !ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip)) | |
8c4f3c3f | 2853 | return 0; |
f7bc8b61 | 2854 | |
8c4f3c3f | 2855 | /* If in notrace hash, we ignore it too */ |
33b7f99c | 2856 | if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip)) |
8c4f3c3f SRRH |
2857 | return 0; |
2858 | ||
2859 | return 1; | |
2860 | } | |
2861 | ||
1dc43cf0 | 2862 | static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs) |
3d083395 | 2863 | { |
85ae32ae | 2864 | struct ftrace_page *pg; |
e94142a6 | 2865 | struct dyn_ftrace *p; |
f22f9a89 | 2866 | cycle_t start, stop; |
1dc43cf0 | 2867 | unsigned long update_cnt = 0; |
b7ffffbb | 2868 | unsigned long rec_flags = 0; |
85ae32ae | 2869 | int i; |
f7bc8b61 | 2870 | |
b7ffffbb SRRH |
2871 | start = ftrace_now(raw_smp_processor_id()); |
2872 | ||
f7bc8b61 | 2873 | /* |
b7ffffbb SRRH |
2874 | * When a module is loaded, this function is called to convert |
2875 | * the calls to mcount in its text to nops, and also to create | |
2876 | * an entry in the ftrace data. Now, if ftrace is activated | |
2877 | * after this call, but before the module sets its text to | |
2878 | * read-only, the modification of enabling ftrace can fail if | |
2879 | * the read-only is done while ftrace is converting the calls. | |
2880 | * To prevent this, the module's records are set as disabled | |
2881 | * and will be enabled after the call to set the module's text | |
2882 | * to read-only. | |
f7bc8b61 | 2883 | */ |
b7ffffbb SRRH |
2884 | if (mod) |
2885 | rec_flags |= FTRACE_FL_DISABLED; | |
3d083395 | 2886 | |
1dc43cf0 | 2887 | for (pg = new_pgs; pg; pg = pg->next) { |
3d083395 | 2888 | |
85ae32ae | 2889 | for (i = 0; i < pg->index; i++) { |
8c4f3c3f | 2890 | |
85ae32ae SR |
2891 | /* If something went wrong, bail without enabling anything */ |
2892 | if (unlikely(ftrace_disabled)) | |
2893 | return -1; | |
f22f9a89 | 2894 | |
85ae32ae | 2895 | p = &pg->records[i]; |
b7ffffbb | 2896 | p->flags = rec_flags; |
f22f9a89 | 2897 | |
85ae32ae SR |
2898 | /* |
2899 | * Do the initial record conversion from mcount jump | |
2900 | * to the NOP instructions. | |
2901 | */ | |
2902 | if (!ftrace_code_disable(mod, p)) | |
2903 | break; | |
5cb084bb | 2904 | |
1dc43cf0 | 2905 | update_cnt++; |
5cb084bb | 2906 | } |
3d083395 SR |
2907 | } |
2908 | ||
750ed1a4 | 2909 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 | 2910 | ftrace_update_time = stop - start; |
1dc43cf0 | 2911 | ftrace_update_tot_cnt += update_cnt; |
3d083395 | 2912 | |
16444a8a ACM |
2913 | return 0; |
2914 | } | |
2915 | ||
a7900875 | 2916 | static int ftrace_allocate_records(struct ftrace_page *pg, int count) |
3c1720f0 | 2917 | { |
a7900875 | 2918 | int order; |
3c1720f0 | 2919 | int cnt; |
3c1720f0 | 2920 | |
a7900875 SR |
2921 | if (WARN_ON(!count)) |
2922 | return -EINVAL; | |
2923 | ||
2924 | order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE)); | |
3c1720f0 SR |
2925 | |
2926 | /* | |
a7900875 SR |
2927 | * We want to fill as much as possible. No more than a page |
2928 | * may be empty. | |
3c1720f0 | 2929 | */ |
a7900875 SR |
2930 | while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE) |
2931 | order--; | |
3c1720f0 | 2932 | |
a7900875 SR |
2933 | again: |
2934 | pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order); | |
3c1720f0 | 2935 | |
a7900875 SR |
2936 | if (!pg->records) { |
2937 | /* if we can't allocate this size, try something smaller */ | |
2938 | if (!order) | |
2939 | return -ENOMEM; | |
2940 | order >>= 1; | |
2941 | goto again; | |
2942 | } | |
3c1720f0 | 2943 | |
a7900875 SR |
2944 | cnt = (PAGE_SIZE << order) / ENTRY_SIZE; |
2945 | pg->size = cnt; | |
3c1720f0 | 2946 | |
a7900875 SR |
2947 | if (cnt > count) |
2948 | cnt = count; | |
2949 | ||
2950 | return cnt; | |
2951 | } | |
2952 | ||
2953 | static struct ftrace_page * | |
2954 | ftrace_allocate_pages(unsigned long num_to_init) | |
2955 | { | |
2956 | struct ftrace_page *start_pg; | |
2957 | struct ftrace_page *pg; | |
2958 | int order; | |
2959 | int cnt; | |
2960 | ||
2961 | if (!num_to_init) | |
2962 | return 0; | |
2963 | ||
2964 | start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL); | |
2965 | if (!pg) | |
2966 | return NULL; | |
2967 | ||
2968 | /* | |
2969 | * Try to allocate as much as possible in one continues | |
2970 | * location that fills in all of the space. We want to | |
2971 | * waste as little space as possible. | |
2972 | */ | |
2973 | for (;;) { | |
2974 | cnt = ftrace_allocate_records(pg, num_to_init); | |
2975 | if (cnt < 0) | |
2976 | goto free_pages; | |
2977 | ||
2978 | num_to_init -= cnt; | |
2979 | if (!num_to_init) | |
3c1720f0 SR |
2980 | break; |
2981 | ||
a7900875 SR |
2982 | pg->next = kzalloc(sizeof(*pg), GFP_KERNEL); |
2983 | if (!pg->next) | |
2984 | goto free_pages; | |
2985 | ||
3c1720f0 SR |
2986 | pg = pg->next; |
2987 | } | |
2988 | ||
a7900875 SR |
2989 | return start_pg; |
2990 | ||
2991 | free_pages: | |
1f61be00 NK |
2992 | pg = start_pg; |
2993 | while (pg) { | |
a7900875 SR |
2994 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
2995 | free_pages((unsigned long)pg->records, order); | |
2996 | start_pg = pg->next; | |
2997 | kfree(pg); | |
2998 | pg = start_pg; | |
2999 | } | |
3000 | pr_info("ftrace: FAILED to allocate memory for functions\n"); | |
3001 | return NULL; | |
3002 | } | |
3003 | ||
5072c59f SR |
3004 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ |
3005 | ||
3006 | struct ftrace_iterator { | |
98c4fd04 | 3007 | loff_t pos; |
4aeb6967 SR |
3008 | loff_t func_pos; |
3009 | struct ftrace_page *pg; | |
3010 | struct dyn_ftrace *func; | |
3011 | struct ftrace_func_probe *probe; | |
3012 | struct trace_parser parser; | |
1cf41dd7 | 3013 | struct ftrace_hash *hash; |
33dc9b12 | 3014 | struct ftrace_ops *ops; |
4aeb6967 SR |
3015 | int hidx; |
3016 | int idx; | |
3017 | unsigned flags; | |
5072c59f SR |
3018 | }; |
3019 | ||
8fc0c701 | 3020 | static void * |
4aeb6967 | 3021 | t_hash_next(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
3022 | { |
3023 | struct ftrace_iterator *iter = m->private; | |
4aeb6967 | 3024 | struct hlist_node *hnd = NULL; |
8fc0c701 SR |
3025 | struct hlist_head *hhd; |
3026 | ||
8fc0c701 | 3027 | (*pos)++; |
98c4fd04 | 3028 | iter->pos = *pos; |
8fc0c701 | 3029 | |
4aeb6967 SR |
3030 | if (iter->probe) |
3031 | hnd = &iter->probe->node; | |
8fc0c701 SR |
3032 | retry: |
3033 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
3034 | return NULL; | |
3035 | ||
3036 | hhd = &ftrace_func_hash[iter->hidx]; | |
3037 | ||
3038 | if (hlist_empty(hhd)) { | |
3039 | iter->hidx++; | |
3040 | hnd = NULL; | |
3041 | goto retry; | |
3042 | } | |
3043 | ||
3044 | if (!hnd) | |
3045 | hnd = hhd->first; | |
3046 | else { | |
3047 | hnd = hnd->next; | |
3048 | if (!hnd) { | |
3049 | iter->hidx++; | |
3050 | goto retry; | |
3051 | } | |
3052 | } | |
3053 | ||
4aeb6967 SR |
3054 | if (WARN_ON_ONCE(!hnd)) |
3055 | return NULL; | |
3056 | ||
3057 | iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node); | |
3058 | ||
3059 | return iter; | |
8fc0c701 SR |
3060 | } |
3061 | ||
3062 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
3063 | { | |
3064 | struct ftrace_iterator *iter = m->private; | |
3065 | void *p = NULL; | |
d82d6244 LZ |
3066 | loff_t l; |
3067 | ||
69a3083c SR |
3068 | if (!(iter->flags & FTRACE_ITER_DO_HASH)) |
3069 | return NULL; | |
3070 | ||
2bccfffd SR |
3071 | if (iter->func_pos > *pos) |
3072 | return NULL; | |
8fc0c701 | 3073 | |
d82d6244 | 3074 | iter->hidx = 0; |
2bccfffd | 3075 | for (l = 0; l <= (*pos - iter->func_pos); ) { |
4aeb6967 | 3076 | p = t_hash_next(m, &l); |
d82d6244 LZ |
3077 | if (!p) |
3078 | break; | |
3079 | } | |
4aeb6967 SR |
3080 | if (!p) |
3081 | return NULL; | |
3082 | ||
98c4fd04 SR |
3083 | /* Only set this if we have an item */ |
3084 | iter->flags |= FTRACE_ITER_HASH; | |
3085 | ||
4aeb6967 | 3086 | return iter; |
8fc0c701 SR |
3087 | } |
3088 | ||
4aeb6967 SR |
3089 | static int |
3090 | t_hash_show(struct seq_file *m, struct ftrace_iterator *iter) | |
8fc0c701 | 3091 | { |
b6887d79 | 3092 | struct ftrace_func_probe *rec; |
8fc0c701 | 3093 | |
4aeb6967 SR |
3094 | rec = iter->probe; |
3095 | if (WARN_ON_ONCE(!rec)) | |
3096 | return -EIO; | |
8fc0c701 | 3097 | |
809dcf29 SR |
3098 | if (rec->ops->print) |
3099 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
3100 | ||
b375a11a | 3101 | seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func); |
8fc0c701 SR |
3102 | |
3103 | if (rec->data) | |
3104 | seq_printf(m, ":%p", rec->data); | |
3105 | seq_putc(m, '\n'); | |
3106 | ||
3107 | return 0; | |
3108 | } | |
3109 | ||
e309b41d | 3110 | static void * |
5072c59f SR |
3111 | t_next(struct seq_file *m, void *v, loff_t *pos) |
3112 | { | |
3113 | struct ftrace_iterator *iter = m->private; | |
fc13cb0c | 3114 | struct ftrace_ops *ops = iter->ops; |
5072c59f SR |
3115 | struct dyn_ftrace *rec = NULL; |
3116 | ||
45a4a237 SR |
3117 | if (unlikely(ftrace_disabled)) |
3118 | return NULL; | |
3119 | ||
8fc0c701 | 3120 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 3121 | return t_hash_next(m, pos); |
8fc0c701 | 3122 | |
5072c59f | 3123 | (*pos)++; |
1106b699 | 3124 | iter->pos = iter->func_pos = *pos; |
5072c59f | 3125 | |
0c75a3ed | 3126 | if (iter->flags & FTRACE_ITER_PRINTALL) |
57c072c7 | 3127 | return t_hash_start(m, pos); |
0c75a3ed | 3128 | |
5072c59f SR |
3129 | retry: |
3130 | if (iter->idx >= iter->pg->index) { | |
3131 | if (iter->pg->next) { | |
3132 | iter->pg = iter->pg->next; | |
3133 | iter->idx = 0; | |
3134 | goto retry; | |
3135 | } | |
3136 | } else { | |
3137 | rec = &iter->pg->records[iter->idx++]; | |
32082309 | 3138 | if (((iter->flags & FTRACE_ITER_FILTER) && |
33b7f99c | 3139 | !(ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))) || |
0183fb1c | 3140 | |
41c52c0d | 3141 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
33b7f99c | 3142 | !ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip)) || |
647bcd03 SR |
3143 | |
3144 | ((iter->flags & FTRACE_ITER_ENABLED) && | |
23ea9c4d | 3145 | !(rec->flags & FTRACE_FL_ENABLED))) { |
647bcd03 | 3146 | |
5072c59f SR |
3147 | rec = NULL; |
3148 | goto retry; | |
3149 | } | |
3150 | } | |
3151 | ||
4aeb6967 | 3152 | if (!rec) |
57c072c7 | 3153 | return t_hash_start(m, pos); |
4aeb6967 SR |
3154 | |
3155 | iter->func = rec; | |
3156 | ||
3157 | return iter; | |
5072c59f SR |
3158 | } |
3159 | ||
98c4fd04 SR |
3160 | static void reset_iter_read(struct ftrace_iterator *iter) |
3161 | { | |
3162 | iter->pos = 0; | |
3163 | iter->func_pos = 0; | |
70f77b3f | 3164 | iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_HASH); |
5072c59f SR |
3165 | } |
3166 | ||
3167 | static void *t_start(struct seq_file *m, loff_t *pos) | |
3168 | { | |
3169 | struct ftrace_iterator *iter = m->private; | |
fc13cb0c | 3170 | struct ftrace_ops *ops = iter->ops; |
5072c59f | 3171 | void *p = NULL; |
694ce0a5 | 3172 | loff_t l; |
5072c59f | 3173 | |
8fc0c701 | 3174 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
3175 | |
3176 | if (unlikely(ftrace_disabled)) | |
3177 | return NULL; | |
3178 | ||
98c4fd04 SR |
3179 | /* |
3180 | * If an lseek was done, then reset and start from beginning. | |
3181 | */ | |
3182 | if (*pos < iter->pos) | |
3183 | reset_iter_read(iter); | |
3184 | ||
0c75a3ed SR |
3185 | /* |
3186 | * For set_ftrace_filter reading, if we have the filter | |
3187 | * off, we can short cut and just print out that all | |
3188 | * functions are enabled. | |
3189 | */ | |
8c006cf7 | 3190 | if ((iter->flags & FTRACE_ITER_FILTER && |
33b7f99c | 3191 | ftrace_hash_empty(ops->func_hash->filter_hash)) || |
8c006cf7 | 3192 | (iter->flags & FTRACE_ITER_NOTRACE && |
33b7f99c | 3193 | ftrace_hash_empty(ops->func_hash->notrace_hash))) { |
0c75a3ed | 3194 | if (*pos > 0) |
8fc0c701 | 3195 | return t_hash_start(m, pos); |
0c75a3ed | 3196 | iter->flags |= FTRACE_ITER_PRINTALL; |
df091625 CW |
3197 | /* reset in case of seek/pread */ |
3198 | iter->flags &= ~FTRACE_ITER_HASH; | |
0c75a3ed SR |
3199 | return iter; |
3200 | } | |
3201 | ||
8fc0c701 SR |
3202 | if (iter->flags & FTRACE_ITER_HASH) |
3203 | return t_hash_start(m, pos); | |
3204 | ||
98c4fd04 SR |
3205 | /* |
3206 | * Unfortunately, we need to restart at ftrace_pages_start | |
3207 | * every time we let go of the ftrace_mutex. This is because | |
3208 | * those pointers can change without the lock. | |
3209 | */ | |
694ce0a5 LZ |
3210 | iter->pg = ftrace_pages_start; |
3211 | iter->idx = 0; | |
3212 | for (l = 0; l <= *pos; ) { | |
3213 | p = t_next(m, p, &l); | |
3214 | if (!p) | |
3215 | break; | |
50cdaf08 | 3216 | } |
5821e1b7 | 3217 | |
69a3083c SR |
3218 | if (!p) |
3219 | return t_hash_start(m, pos); | |
4aeb6967 SR |
3220 | |
3221 | return iter; | |
5072c59f SR |
3222 | } |
3223 | ||
3224 | static void t_stop(struct seq_file *m, void *p) | |
3225 | { | |
8fc0c701 | 3226 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
3227 | } |
3228 | ||
15d5b02c SRRH |
3229 | void * __weak |
3230 | arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec) | |
3231 | { | |
3232 | return NULL; | |
3233 | } | |
3234 | ||
3235 | static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops, | |
3236 | struct dyn_ftrace *rec) | |
3237 | { | |
3238 | void *ptr; | |
3239 | ||
3240 | ptr = arch_ftrace_trampoline_func(ops, rec); | |
3241 | if (ptr) | |
3242 | seq_printf(m, " ->%pS", ptr); | |
3243 | } | |
3244 | ||
5072c59f SR |
3245 | static int t_show(struct seq_file *m, void *v) |
3246 | { | |
0c75a3ed | 3247 | struct ftrace_iterator *iter = m->private; |
4aeb6967 | 3248 | struct dyn_ftrace *rec; |
5072c59f | 3249 | |
8fc0c701 | 3250 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 3251 | return t_hash_show(m, iter); |
8fc0c701 | 3252 | |
0c75a3ed | 3253 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
8c006cf7 | 3254 | if (iter->flags & FTRACE_ITER_NOTRACE) |
fa6f0cc7 | 3255 | seq_puts(m, "#### no functions disabled ####\n"); |
8c006cf7 | 3256 | else |
fa6f0cc7 | 3257 | seq_puts(m, "#### all functions enabled ####\n"); |
0c75a3ed SR |
3258 | return 0; |
3259 | } | |
3260 | ||
4aeb6967 SR |
3261 | rec = iter->func; |
3262 | ||
5072c59f SR |
3263 | if (!rec) |
3264 | return 0; | |
3265 | ||
647bcd03 | 3266 | seq_printf(m, "%ps", (void *)rec->ip); |
9674b2fa | 3267 | if (iter->flags & FTRACE_ITER_ENABLED) { |
030f4e1c | 3268 | struct ftrace_ops *ops; |
15d5b02c | 3269 | |
f8b8be8a | 3270 | seq_printf(m, " (%ld)%s%s", |
0376bde1 | 3271 | ftrace_rec_count(rec), |
f8b8be8a MH |
3272 | rec->flags & FTRACE_FL_REGS ? " R" : " ", |
3273 | rec->flags & FTRACE_FL_IPMODIFY ? " I" : " "); | |
9674b2fa | 3274 | if (rec->flags & FTRACE_FL_TRAMP_EN) { |
5fecaa04 | 3275 | ops = ftrace_find_tramp_ops_any(rec); |
39daa7b9 SRRH |
3276 | if (ops) { |
3277 | do { | |
3278 | seq_printf(m, "\ttramp: %pS (%pS)", | |
3279 | (void *)ops->trampoline, | |
3280 | (void *)ops->func); | |
030f4e1c | 3281 | add_trampoline_func(m, ops, rec); |
39daa7b9 SRRH |
3282 | ops = ftrace_find_tramp_ops_next(rec, ops); |
3283 | } while (ops); | |
3284 | } else | |
fa6f0cc7 | 3285 | seq_puts(m, "\ttramp: ERROR!"); |
030f4e1c SRRH |
3286 | } else { |
3287 | add_trampoline_func(m, NULL, rec); | |
9674b2fa SRRH |
3288 | } |
3289 | } | |
3290 | ||
fa6f0cc7 | 3291 | seq_putc(m, '\n'); |
5072c59f SR |
3292 | |
3293 | return 0; | |
3294 | } | |
3295 | ||
88e9d34c | 3296 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
3297 | .start = t_start, |
3298 | .next = t_next, | |
3299 | .stop = t_stop, | |
3300 | .show = t_show, | |
3301 | }; | |
3302 | ||
e309b41d | 3303 | static int |
5072c59f SR |
3304 | ftrace_avail_open(struct inode *inode, struct file *file) |
3305 | { | |
3306 | struct ftrace_iterator *iter; | |
5072c59f | 3307 | |
4eebcc81 SR |
3308 | if (unlikely(ftrace_disabled)) |
3309 | return -ENODEV; | |
3310 | ||
50e18b94 JO |
3311 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
3312 | if (iter) { | |
3313 | iter->pg = ftrace_pages_start; | |
3314 | iter->ops = &global_ops; | |
4bf39a94 | 3315 | } |
5072c59f | 3316 | |
50e18b94 | 3317 | return iter ? 0 : -ENOMEM; |
5072c59f SR |
3318 | } |
3319 | ||
647bcd03 SR |
3320 | static int |
3321 | ftrace_enabled_open(struct inode *inode, struct file *file) | |
3322 | { | |
3323 | struct ftrace_iterator *iter; | |
647bcd03 | 3324 | |
50e18b94 JO |
3325 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
3326 | if (iter) { | |
3327 | iter->pg = ftrace_pages_start; | |
3328 | iter->flags = FTRACE_ITER_ENABLED; | |
3329 | iter->ops = &global_ops; | |
647bcd03 SR |
3330 | } |
3331 | ||
50e18b94 | 3332 | return iter ? 0 : -ENOMEM; |
647bcd03 SR |
3333 | } |
3334 | ||
fc13cb0c SR |
3335 | /** |
3336 | * ftrace_regex_open - initialize function tracer filter files | |
3337 | * @ops: The ftrace_ops that hold the hash filters | |
3338 | * @flag: The type of filter to process | |
3339 | * @inode: The inode, usually passed in to your open routine | |
3340 | * @file: The file, usually passed in to your open routine | |
3341 | * | |
3342 | * ftrace_regex_open() initializes the filter files for the | |
3343 | * @ops. Depending on @flag it may process the filter hash or | |
3344 | * the notrace hash of @ops. With this called from the open | |
3345 | * routine, you can use ftrace_filter_write() for the write | |
3346 | * routine if @flag has FTRACE_ITER_FILTER set, or | |
3347 | * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set. | |
098c879e | 3348 | * tracing_lseek() should be used as the lseek routine, and |
fc13cb0c SR |
3349 | * release must call ftrace_regex_release(). |
3350 | */ | |
3351 | int | |
f45948e8 | 3352 | ftrace_regex_open(struct ftrace_ops *ops, int flag, |
1cf41dd7 | 3353 | struct inode *inode, struct file *file) |
5072c59f SR |
3354 | { |
3355 | struct ftrace_iterator *iter; | |
f45948e8 | 3356 | struct ftrace_hash *hash; |
5072c59f SR |
3357 | int ret = 0; |
3358 | ||
f04f24fb MH |
3359 | ftrace_ops_init(ops); |
3360 | ||
4eebcc81 SR |
3361 | if (unlikely(ftrace_disabled)) |
3362 | return -ENODEV; | |
3363 | ||
5072c59f SR |
3364 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
3365 | if (!iter) | |
3366 | return -ENOMEM; | |
3367 | ||
689fd8b6 | 3368 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) { |
3369 | kfree(iter); | |
3370 | return -ENOMEM; | |
3371 | } | |
3372 | ||
3f2367ba MH |
3373 | iter->ops = ops; |
3374 | iter->flags = flag; | |
3375 | ||
33b7f99c | 3376 | mutex_lock(&ops->func_hash->regex_lock); |
3f2367ba | 3377 | |
f45948e8 | 3378 | if (flag & FTRACE_ITER_NOTRACE) |
33b7f99c | 3379 | hash = ops->func_hash->notrace_hash; |
f45948e8 | 3380 | else |
33b7f99c | 3381 | hash = ops->func_hash->filter_hash; |
f45948e8 | 3382 | |
33dc9b12 | 3383 | if (file->f_mode & FMODE_WRITE) { |
ef2fbe16 NK |
3384 | const int size_bits = FTRACE_HASH_DEFAULT_BITS; |
3385 | ||
3386 | if (file->f_flags & O_TRUNC) | |
3387 | iter->hash = alloc_ftrace_hash(size_bits); | |
3388 | else | |
3389 | iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash); | |
3390 | ||
33dc9b12 SR |
3391 | if (!iter->hash) { |
3392 | trace_parser_put(&iter->parser); | |
3393 | kfree(iter); | |
3f2367ba MH |
3394 | ret = -ENOMEM; |
3395 | goto out_unlock; | |
33dc9b12 SR |
3396 | } |
3397 | } | |
1cf41dd7 | 3398 | |
5072c59f SR |
3399 | if (file->f_mode & FMODE_READ) { |
3400 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
3401 | |
3402 | ret = seq_open(file, &show_ftrace_seq_ops); | |
3403 | if (!ret) { | |
3404 | struct seq_file *m = file->private_data; | |
3405 | m->private = iter; | |
79fe249c | 3406 | } else { |
33dc9b12 SR |
3407 | /* Failed */ |
3408 | free_ftrace_hash(iter->hash); | |
79fe249c | 3409 | trace_parser_put(&iter->parser); |
5072c59f | 3410 | kfree(iter); |
79fe249c | 3411 | } |
5072c59f SR |
3412 | } else |
3413 | file->private_data = iter; | |
3f2367ba MH |
3414 | |
3415 | out_unlock: | |
33b7f99c | 3416 | mutex_unlock(&ops->func_hash->regex_lock); |
5072c59f SR |
3417 | |
3418 | return ret; | |
3419 | } | |
3420 | ||
41c52c0d SR |
3421 | static int |
3422 | ftrace_filter_open(struct inode *inode, struct file *file) | |
3423 | { | |
e3b3e2e8 SRRH |
3424 | struct ftrace_ops *ops = inode->i_private; |
3425 | ||
3426 | return ftrace_regex_open(ops, | |
69a3083c SR |
3427 | FTRACE_ITER_FILTER | FTRACE_ITER_DO_HASH, |
3428 | inode, file); | |
41c52c0d SR |
3429 | } |
3430 | ||
3431 | static int | |
3432 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
3433 | { | |
e3b3e2e8 SRRH |
3434 | struct ftrace_ops *ops = inode->i_private; |
3435 | ||
3436 | return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE, | |
1cf41dd7 | 3437 | inode, file); |
41c52c0d SR |
3438 | } |
3439 | ||
3ba00929 DS |
3440 | /* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */ |
3441 | struct ftrace_glob { | |
3442 | char *search; | |
3443 | unsigned len; | |
3444 | int type; | |
3445 | }; | |
3446 | ||
3447 | static int ftrace_match(char *str, struct ftrace_glob *g) | |
9f4801e3 | 3448 | { |
9f4801e3 | 3449 | int matched = 0; |
751e9983 | 3450 | int slen; |
9f4801e3 | 3451 | |
3ba00929 | 3452 | switch (g->type) { |
9f4801e3 | 3453 | case MATCH_FULL: |
3ba00929 | 3454 | if (strcmp(str, g->search) == 0) |
9f4801e3 SR |
3455 | matched = 1; |
3456 | break; | |
3457 | case MATCH_FRONT_ONLY: | |
3ba00929 | 3458 | if (strncmp(str, g->search, g->len) == 0) |
9f4801e3 SR |
3459 | matched = 1; |
3460 | break; | |
3461 | case MATCH_MIDDLE_ONLY: | |
3ba00929 | 3462 | if (strstr(str, g->search)) |
9f4801e3 SR |
3463 | matched = 1; |
3464 | break; | |
3465 | case MATCH_END_ONLY: | |
751e9983 | 3466 | slen = strlen(str); |
3ba00929 DS |
3467 | if (slen >= g->len && |
3468 | memcmp(str + slen - g->len, g->search, g->len) == 0) | |
9f4801e3 SR |
3469 | matched = 1; |
3470 | break; | |
3471 | } | |
3472 | ||
3473 | return matched; | |
3474 | } | |
3475 | ||
b448c4e3 | 3476 | static int |
f0a3b154 | 3477 | enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter) |
996e87be | 3478 | { |
b448c4e3 | 3479 | struct ftrace_func_entry *entry; |
b448c4e3 SR |
3480 | int ret = 0; |
3481 | ||
1cf41dd7 | 3482 | entry = ftrace_lookup_ip(hash, rec->ip); |
f0a3b154 | 3483 | if (clear_filter) { |
1cf41dd7 SR |
3484 | /* Do nothing if it doesn't exist */ |
3485 | if (!entry) | |
3486 | return 0; | |
b448c4e3 | 3487 | |
33dc9b12 | 3488 | free_hash_entry(hash, entry); |
1cf41dd7 SR |
3489 | } else { |
3490 | /* Do nothing if it exists */ | |
3491 | if (entry) | |
3492 | return 0; | |
b448c4e3 | 3493 | |
1cf41dd7 | 3494 | ret = add_hash_entry(hash, rec->ip); |
b448c4e3 SR |
3495 | } |
3496 | return ret; | |
996e87be SR |
3497 | } |
3498 | ||
64e7c440 | 3499 | static int |
0b507e1e DS |
3500 | ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g, |
3501 | struct ftrace_glob *mod_g, int exclude_mod) | |
64e7c440 SR |
3502 | { |
3503 | char str[KSYM_SYMBOL_LEN]; | |
b9df92d2 SR |
3504 | char *modname; |
3505 | ||
3506 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
3507 | ||
0b507e1e DS |
3508 | if (mod_g) { |
3509 | int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0; | |
3510 | ||
3511 | /* blank module name to match all modules */ | |
3512 | if (!mod_g->len) { | |
3513 | /* blank module globbing: modname xor exclude_mod */ | |
3514 | if ((!exclude_mod) != (!modname)) | |
3515 | goto func_match; | |
3516 | return 0; | |
3517 | } | |
3518 | ||
3519 | /* not matching the module */ | |
3520 | if (!modname || !mod_matches) { | |
3521 | if (exclude_mod) | |
3522 | goto func_match; | |
3523 | else | |
3524 | return 0; | |
3525 | } | |
3526 | ||
3527 | if (mod_matches && exclude_mod) | |
b9df92d2 SR |
3528 | return 0; |
3529 | ||
0b507e1e | 3530 | func_match: |
b9df92d2 | 3531 | /* blank search means to match all funcs in the mod */ |
3ba00929 | 3532 | if (!func_g->len) |
b9df92d2 SR |
3533 | return 1; |
3534 | } | |
64e7c440 | 3535 | |
3ba00929 | 3536 | return ftrace_match(str, func_g); |
64e7c440 SR |
3537 | } |
3538 | ||
1cf41dd7 | 3539 | static int |
3ba00929 | 3540 | match_records(struct ftrace_hash *hash, char *func, int len, char *mod) |
9f4801e3 | 3541 | { |
9f4801e3 SR |
3542 | struct ftrace_page *pg; |
3543 | struct dyn_ftrace *rec; | |
3ba00929 | 3544 | struct ftrace_glob func_g = { .type = MATCH_FULL }; |
0b507e1e DS |
3545 | struct ftrace_glob mod_g = { .type = MATCH_FULL }; |
3546 | struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL; | |
3547 | int exclude_mod = 0; | |
311d16da | 3548 | int found = 0; |
b448c4e3 | 3549 | int ret; |
f0a3b154 | 3550 | int clear_filter; |
9f4801e3 | 3551 | |
0b507e1e | 3552 | if (func) { |
3ba00929 DS |
3553 | func_g.type = filter_parse_regex(func, len, &func_g.search, |
3554 | &clear_filter); | |
3555 | func_g.len = strlen(func_g.search); | |
b9df92d2 | 3556 | } |
9f4801e3 | 3557 | |
0b507e1e DS |
3558 | if (mod) { |
3559 | mod_g.type = filter_parse_regex(mod, strlen(mod), | |
3560 | &mod_g.search, &exclude_mod); | |
3561 | mod_g.len = strlen(mod_g.search); | |
b9df92d2 | 3562 | } |
9f4801e3 | 3563 | |
52baf119 | 3564 | mutex_lock(&ftrace_lock); |
265c831c | 3565 | |
b9df92d2 SR |
3566 | if (unlikely(ftrace_disabled)) |
3567 | goto out_unlock; | |
9f4801e3 | 3568 | |
265c831c | 3569 | do_for_each_ftrace_rec(pg, rec) { |
0b507e1e | 3570 | if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) { |
f0a3b154 | 3571 | ret = enter_record(hash, rec, clear_filter); |
b448c4e3 SR |
3572 | if (ret < 0) { |
3573 | found = ret; | |
3574 | goto out_unlock; | |
3575 | } | |
311d16da | 3576 | found = 1; |
265c831c SR |
3577 | } |
3578 | } while_for_each_ftrace_rec(); | |
b9df92d2 | 3579 | out_unlock: |
52baf119 | 3580 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
3581 | |
3582 | return found; | |
5072c59f SR |
3583 | } |
3584 | ||
64e7c440 | 3585 | static int |
1cf41dd7 | 3586 | ftrace_match_records(struct ftrace_hash *hash, char *buff, int len) |
64e7c440 | 3587 | { |
f0a3b154 | 3588 | return match_records(hash, buff, len, NULL); |
64e7c440 SR |
3589 | } |
3590 | ||
64e7c440 | 3591 | |
f6180773 SR |
3592 | /* |
3593 | * We register the module command as a template to show others how | |
3594 | * to register the a command as well. | |
3595 | */ | |
3596 | ||
3597 | static int | |
43dd61c9 | 3598 | ftrace_mod_callback(struct ftrace_hash *hash, |
f0a3b154 | 3599 | char *func, char *cmd, char *module, int enable) |
f6180773 | 3600 | { |
5e3949f0 | 3601 | int ret; |
f6180773 SR |
3602 | |
3603 | /* | |
3604 | * cmd == 'mod' because we only registered this func | |
3605 | * for the 'mod' ftrace_func_command. | |
3606 | * But if you register one func with multiple commands, | |
3607 | * you can tell which command was used by the cmd | |
3608 | * parameter. | |
3609 | */ | |
f0a3b154 | 3610 | ret = match_records(hash, func, strlen(func), module); |
b448c4e3 | 3611 | if (!ret) |
5e3949f0 | 3612 | return -EINVAL; |
b448c4e3 SR |
3613 | if (ret < 0) |
3614 | return ret; | |
b448c4e3 | 3615 | return 0; |
f6180773 SR |
3616 | } |
3617 | ||
3618 | static struct ftrace_func_command ftrace_mod_cmd = { | |
3619 | .name = "mod", | |
3620 | .func = ftrace_mod_callback, | |
3621 | }; | |
3622 | ||
3623 | static int __init ftrace_mod_cmd_init(void) | |
3624 | { | |
3625 | return register_ftrace_command(&ftrace_mod_cmd); | |
3626 | } | |
6f415672 | 3627 | core_initcall(ftrace_mod_cmd_init); |
f6180773 | 3628 | |
2f5f6ad9 | 3629 | static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 3630 | struct ftrace_ops *op, struct pt_regs *pt_regs) |
59df055f | 3631 | { |
b6887d79 | 3632 | struct ftrace_func_probe *entry; |
59df055f | 3633 | struct hlist_head *hhd; |
59df055f | 3634 | unsigned long key; |
59df055f SR |
3635 | |
3636 | key = hash_long(ip, FTRACE_HASH_BITS); | |
3637 | ||
3638 | hhd = &ftrace_func_hash[key]; | |
3639 | ||
3640 | if (hlist_empty(hhd)) | |
3641 | return; | |
3642 | ||
3643 | /* | |
3644 | * Disable preemption for these calls to prevent a RCU grace | |
3645 | * period. This syncs the hash iteration and freeing of items | |
3646 | * on the hash. rcu_read_lock is too dangerous here. | |
3647 | */ | |
5168ae50 | 3648 | preempt_disable_notrace(); |
1bb539ca | 3649 | hlist_for_each_entry_rcu_notrace(entry, hhd, node) { |
59df055f SR |
3650 | if (entry->ip == ip) |
3651 | entry->ops->func(ip, parent_ip, &entry->data); | |
3652 | } | |
5168ae50 | 3653 | preempt_enable_notrace(); |
59df055f SR |
3654 | } |
3655 | ||
b6887d79 | 3656 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 3657 | { |
fb9fb015 | 3658 | .func = function_trace_probe_call, |
f04f24fb | 3659 | .flags = FTRACE_OPS_FL_INITIALIZED, |
33b7f99c | 3660 | INIT_OPS_HASH(trace_probe_ops) |
59df055f SR |
3661 | }; |
3662 | ||
b6887d79 | 3663 | static int ftrace_probe_registered; |
59df055f | 3664 | |
7485058e | 3665 | static void __enable_ftrace_function_probe(struct ftrace_ops_hash *old_hash) |
59df055f | 3666 | { |
b848914c | 3667 | int ret; |
59df055f SR |
3668 | int i; |
3669 | ||
19dd603e SRRH |
3670 | if (ftrace_probe_registered) { |
3671 | /* still need to update the function call sites */ | |
3672 | if (ftrace_enabled) | |
8252ecf3 SRRH |
3673 | ftrace_run_modify_code(&trace_probe_ops, FTRACE_UPDATE_CALLS, |
3674 | old_hash); | |
59df055f | 3675 | return; |
19dd603e | 3676 | } |
59df055f SR |
3677 | |
3678 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
3679 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
3680 | if (hhd->first) | |
3681 | break; | |
3682 | } | |
3683 | /* Nothing registered? */ | |
3684 | if (i == FTRACE_FUNC_HASHSIZE) | |
3685 | return; | |
3686 | ||
8a56d776 | 3687 | ret = ftrace_startup(&trace_probe_ops, 0); |
b848914c | 3688 | |
b6887d79 | 3689 | ftrace_probe_registered = 1; |
59df055f SR |
3690 | } |
3691 | ||
b6887d79 | 3692 | static void __disable_ftrace_function_probe(void) |
59df055f SR |
3693 | { |
3694 | int i; | |
3695 | ||
b6887d79 | 3696 | if (!ftrace_probe_registered) |
59df055f SR |
3697 | return; |
3698 | ||
3699 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
3700 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
3701 | if (hhd->first) | |
3702 | return; | |
3703 | } | |
3704 | ||
3705 | /* no more funcs left */ | |
8a56d776 | 3706 | ftrace_shutdown(&trace_probe_ops, 0); |
b848914c | 3707 | |
b6887d79 | 3708 | ftrace_probe_registered = 0; |
59df055f SR |
3709 | } |
3710 | ||
3711 | ||
7818b388 | 3712 | static void ftrace_free_entry(struct ftrace_func_probe *entry) |
59df055f | 3713 | { |
59df055f | 3714 | if (entry->ops->free) |
e67efb93 | 3715 | entry->ops->free(entry->ops, entry->ip, &entry->data); |
59df055f SR |
3716 | kfree(entry); |
3717 | } | |
3718 | ||
59df055f | 3719 | int |
b6887d79 | 3720 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3721 | void *data) |
3722 | { | |
7485058e | 3723 | struct ftrace_ops_hash old_hash_ops; |
b6887d79 | 3724 | struct ftrace_func_probe *entry; |
3ba00929 | 3725 | struct ftrace_glob func_g; |
33b7f99c | 3726 | struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash; |
3296fc4e | 3727 | struct ftrace_hash *old_hash = *orig_hash; |
e1df4cb6 | 3728 | struct ftrace_hash *hash; |
59df055f SR |
3729 | struct ftrace_page *pg; |
3730 | struct dyn_ftrace *rec; | |
3ba00929 | 3731 | int not; |
6a24a244 | 3732 | unsigned long key; |
59df055f | 3733 | int count = 0; |
e1df4cb6 | 3734 | int ret; |
59df055f | 3735 | |
3ba00929 DS |
3736 | func_g.type = filter_parse_regex(glob, strlen(glob), |
3737 | &func_g.search, ¬); | |
3738 | func_g.len = strlen(func_g.search); | |
59df055f | 3739 | |
b6887d79 | 3740 | /* we do not support '!' for function probes */ |
59df055f SR |
3741 | if (WARN_ON(not)) |
3742 | return -EINVAL; | |
3743 | ||
33b7f99c | 3744 | mutex_lock(&trace_probe_ops.func_hash->regex_lock); |
59df055f | 3745 | |
7485058e SRRH |
3746 | old_hash_ops.filter_hash = old_hash; |
3747 | /* Probes only have filters */ | |
3748 | old_hash_ops.notrace_hash = NULL; | |
3749 | ||
3296fc4e | 3750 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); |
e1df4cb6 SRRH |
3751 | if (!hash) { |
3752 | count = -ENOMEM; | |
5ae0bf59 | 3753 | goto out; |
e1df4cb6 SRRH |
3754 | } |
3755 | ||
3756 | if (unlikely(ftrace_disabled)) { | |
3757 | count = -ENODEV; | |
5ae0bf59 | 3758 | goto out; |
e1df4cb6 | 3759 | } |
59df055f | 3760 | |
5ae0bf59 SRRH |
3761 | mutex_lock(&ftrace_lock); |
3762 | ||
45a4a237 | 3763 | do_for_each_ftrace_rec(pg, rec) { |
59df055f | 3764 | |
0b507e1e | 3765 | if (!ftrace_match_record(rec, &func_g, NULL, 0)) |
59df055f SR |
3766 | continue; |
3767 | ||
3768 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
3769 | if (!entry) { | |
b6887d79 | 3770 | /* If we did not process any, then return error */ |
59df055f SR |
3771 | if (!count) |
3772 | count = -ENOMEM; | |
3773 | goto out_unlock; | |
3774 | } | |
3775 | ||
3776 | count++; | |
3777 | ||
3778 | entry->data = data; | |
3779 | ||
3780 | /* | |
3781 | * The caller might want to do something special | |
3782 | * for each function we find. We call the callback | |
3783 | * to give the caller an opportunity to do so. | |
3784 | */ | |
e67efb93 SRRH |
3785 | if (ops->init) { |
3786 | if (ops->init(ops, rec->ip, &entry->data) < 0) { | |
59df055f SR |
3787 | /* caller does not like this func */ |
3788 | kfree(entry); | |
3789 | continue; | |
3790 | } | |
3791 | } | |
3792 | ||
e1df4cb6 SRRH |
3793 | ret = enter_record(hash, rec, 0); |
3794 | if (ret < 0) { | |
3795 | kfree(entry); | |
3796 | count = ret; | |
3797 | goto out_unlock; | |
3798 | } | |
3799 | ||
59df055f SR |
3800 | entry->ops = ops; |
3801 | entry->ip = rec->ip; | |
3802 | ||
3803 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
3804 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
3805 | ||
3806 | } while_for_each_ftrace_rec(); | |
e1df4cb6 SRRH |
3807 | |
3808 | ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash); | |
8252ecf3 | 3809 | |
7485058e | 3810 | __enable_ftrace_function_probe(&old_hash_ops); |
8252ecf3 | 3811 | |
3296fc4e SRRH |
3812 | if (!ret) |
3813 | free_ftrace_hash_rcu(old_hash); | |
3814 | else | |
e1df4cb6 SRRH |
3815 | count = ret; |
3816 | ||
59df055f | 3817 | out_unlock: |
5ae0bf59 SRRH |
3818 | mutex_unlock(&ftrace_lock); |
3819 | out: | |
33b7f99c | 3820 | mutex_unlock(&trace_probe_ops.func_hash->regex_lock); |
e1df4cb6 | 3821 | free_ftrace_hash(hash); |
59df055f SR |
3822 | |
3823 | return count; | |
3824 | } | |
3825 | ||
3826 | enum { | |
b6887d79 SR |
3827 | PROBE_TEST_FUNC = 1, |
3828 | PROBE_TEST_DATA = 2 | |
59df055f SR |
3829 | }; |
3830 | ||
3831 | static void | |
b6887d79 | 3832 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3833 | void *data, int flags) |
3834 | { | |
e1df4cb6 | 3835 | struct ftrace_func_entry *rec_entry; |
b6887d79 | 3836 | struct ftrace_func_probe *entry; |
7818b388 | 3837 | struct ftrace_func_probe *p; |
3ba00929 | 3838 | struct ftrace_glob func_g; |
33b7f99c | 3839 | struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash; |
3296fc4e | 3840 | struct ftrace_hash *old_hash = *orig_hash; |
7818b388 | 3841 | struct list_head free_list; |
e1df4cb6 | 3842 | struct ftrace_hash *hash; |
b67bfe0d | 3843 | struct hlist_node *tmp; |
59df055f | 3844 | char str[KSYM_SYMBOL_LEN]; |
3ba00929 | 3845 | int i, ret; |
59df055f | 3846 | |
b36461da | 3847 | if (glob && (strcmp(glob, "*") == 0 || !strlen(glob))) |
3ba00929 | 3848 | func_g.search = NULL; |
b36461da | 3849 | else if (glob) { |
59df055f SR |
3850 | int not; |
3851 | ||
3ba00929 DS |
3852 | func_g.type = filter_parse_regex(glob, strlen(glob), |
3853 | &func_g.search, ¬); | |
3854 | func_g.len = strlen(func_g.search); | |
3855 | func_g.search = glob; | |
59df055f | 3856 | |
b6887d79 | 3857 | /* we do not support '!' for function probes */ |
59df055f SR |
3858 | if (WARN_ON(not)) |
3859 | return; | |
3860 | } | |
3861 | ||
33b7f99c | 3862 | mutex_lock(&trace_probe_ops.func_hash->regex_lock); |
e1df4cb6 SRRH |
3863 | |
3864 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
3865 | if (!hash) | |
3866 | /* Hmm, should report this somehow */ | |
3867 | goto out_unlock; | |
3868 | ||
7818b388 SRRH |
3869 | INIT_LIST_HEAD(&free_list); |
3870 | ||
59df055f SR |
3871 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { |
3872 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
3873 | ||
b67bfe0d | 3874 | hlist_for_each_entry_safe(entry, tmp, hhd, node) { |
59df055f SR |
3875 | |
3876 | /* break up if statements for readability */ | |
b6887d79 | 3877 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
3878 | continue; |
3879 | ||
b6887d79 | 3880 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
3881 | continue; |
3882 | ||
3883 | /* do this last, since it is the most expensive */ | |
3ba00929 | 3884 | if (func_g.search) { |
59df055f SR |
3885 | kallsyms_lookup(entry->ip, NULL, NULL, |
3886 | NULL, str); | |
3ba00929 | 3887 | if (!ftrace_match(str, &func_g)) |
59df055f SR |
3888 | continue; |
3889 | } | |
3890 | ||
e1df4cb6 SRRH |
3891 | rec_entry = ftrace_lookup_ip(hash, entry->ip); |
3892 | /* It is possible more than one entry had this ip */ | |
3893 | if (rec_entry) | |
3894 | free_hash_entry(hash, rec_entry); | |
3895 | ||
740466bc | 3896 | hlist_del_rcu(&entry->node); |
7818b388 | 3897 | list_add(&entry->free_list, &free_list); |
59df055f SR |
3898 | } |
3899 | } | |
3f2367ba | 3900 | mutex_lock(&ftrace_lock); |
b6887d79 | 3901 | __disable_ftrace_function_probe(); |
e1df4cb6 SRRH |
3902 | /* |
3903 | * Remove after the disable is called. Otherwise, if the last | |
3904 | * probe is removed, a null hash means *all enabled*. | |
3905 | */ | |
3296fc4e | 3906 | ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash); |
7818b388 | 3907 | synchronize_sched(); |
3296fc4e SRRH |
3908 | if (!ret) |
3909 | free_ftrace_hash_rcu(old_hash); | |
3910 | ||
7818b388 SRRH |
3911 | list_for_each_entry_safe(entry, p, &free_list, free_list) { |
3912 | list_del(&entry->free_list); | |
3913 | ftrace_free_entry(entry); | |
3914 | } | |
3f2367ba | 3915 | mutex_unlock(&ftrace_lock); |
3ba00929 | 3916 | |
e1df4cb6 | 3917 | out_unlock: |
33b7f99c | 3918 | mutex_unlock(&trace_probe_ops.func_hash->regex_lock); |
e1df4cb6 | 3919 | free_ftrace_hash(hash); |
59df055f SR |
3920 | } |
3921 | ||
3922 | void | |
b6887d79 | 3923 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3924 | void *data) |
3925 | { | |
b6887d79 SR |
3926 | __unregister_ftrace_function_probe(glob, ops, data, |
3927 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
3928 | } |
3929 | ||
3930 | void | |
b6887d79 | 3931 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 3932 | { |
b6887d79 | 3933 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
3934 | } |
3935 | ||
b6887d79 | 3936 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 3937 | { |
b6887d79 | 3938 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
3939 | } |
3940 | ||
f6180773 SR |
3941 | static LIST_HEAD(ftrace_commands); |
3942 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
3943 | ||
38de93ab TZ |
3944 | /* |
3945 | * Currently we only register ftrace commands from __init, so mark this | |
3946 | * __init too. | |
3947 | */ | |
3948 | __init int register_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
3949 | { |
3950 | struct ftrace_func_command *p; | |
3951 | int ret = 0; | |
3952 | ||
3953 | mutex_lock(&ftrace_cmd_mutex); | |
3954 | list_for_each_entry(p, &ftrace_commands, list) { | |
3955 | if (strcmp(cmd->name, p->name) == 0) { | |
3956 | ret = -EBUSY; | |
3957 | goto out_unlock; | |
3958 | } | |
3959 | } | |
3960 | list_add(&cmd->list, &ftrace_commands); | |
3961 | out_unlock: | |
3962 | mutex_unlock(&ftrace_cmd_mutex); | |
3963 | ||
3964 | return ret; | |
3965 | } | |
3966 | ||
38de93ab TZ |
3967 | /* |
3968 | * Currently we only unregister ftrace commands from __init, so mark | |
3969 | * this __init too. | |
3970 | */ | |
3971 | __init int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
3972 | { |
3973 | struct ftrace_func_command *p, *n; | |
3974 | int ret = -ENODEV; | |
3975 | ||
3976 | mutex_lock(&ftrace_cmd_mutex); | |
3977 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
3978 | if (strcmp(cmd->name, p->name) == 0) { | |
3979 | ret = 0; | |
3980 | list_del_init(&p->list); | |
3981 | goto out_unlock; | |
3982 | } | |
3983 | } | |
3984 | out_unlock: | |
3985 | mutex_unlock(&ftrace_cmd_mutex); | |
3986 | ||
3987 | return ret; | |
3988 | } | |
3989 | ||
33dc9b12 SR |
3990 | static int ftrace_process_regex(struct ftrace_hash *hash, |
3991 | char *buff, int len, int enable) | |
64e7c440 | 3992 | { |
f6180773 | 3993 | char *func, *command, *next = buff; |
6a24a244 | 3994 | struct ftrace_func_command *p; |
0aff1c0c | 3995 | int ret = -EINVAL; |
64e7c440 SR |
3996 | |
3997 | func = strsep(&next, ":"); | |
3998 | ||
3999 | if (!next) { | |
1cf41dd7 | 4000 | ret = ftrace_match_records(hash, func, len); |
b448c4e3 SR |
4001 | if (!ret) |
4002 | ret = -EINVAL; | |
4003 | if (ret < 0) | |
4004 | return ret; | |
4005 | return 0; | |
64e7c440 SR |
4006 | } |
4007 | ||
f6180773 | 4008 | /* command found */ |
64e7c440 SR |
4009 | |
4010 | command = strsep(&next, ":"); | |
4011 | ||
f6180773 SR |
4012 | mutex_lock(&ftrace_cmd_mutex); |
4013 | list_for_each_entry(p, &ftrace_commands, list) { | |
4014 | if (strcmp(p->name, command) == 0) { | |
43dd61c9 | 4015 | ret = p->func(hash, func, command, next, enable); |
f6180773 SR |
4016 | goto out_unlock; |
4017 | } | |
64e7c440 | 4018 | } |
f6180773 SR |
4019 | out_unlock: |
4020 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 4021 | |
f6180773 | 4022 | return ret; |
64e7c440 SR |
4023 | } |
4024 | ||
e309b41d | 4025 | static ssize_t |
41c52c0d SR |
4026 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
4027 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
4028 | { |
4029 | struct ftrace_iterator *iter; | |
689fd8b6 | 4030 | struct trace_parser *parser; |
4031 | ssize_t ret, read; | |
5072c59f | 4032 | |
4ba7978e | 4033 | if (!cnt) |
5072c59f SR |
4034 | return 0; |
4035 | ||
5072c59f SR |
4036 | if (file->f_mode & FMODE_READ) { |
4037 | struct seq_file *m = file->private_data; | |
4038 | iter = m->private; | |
4039 | } else | |
4040 | iter = file->private_data; | |
4041 | ||
f04f24fb | 4042 | if (unlikely(ftrace_disabled)) |
3f2367ba MH |
4043 | return -ENODEV; |
4044 | ||
4045 | /* iter->hash is a local copy, so we don't need regex_lock */ | |
f04f24fb | 4046 | |
689fd8b6 | 4047 | parser = &iter->parser; |
4048 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 4049 | |
4ba7978e | 4050 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 4051 | !trace_parser_cont(parser)) { |
33dc9b12 | 4052 | ret = ftrace_process_regex(iter->hash, parser->buffer, |
689fd8b6 | 4053 | parser->idx, enable); |
313254a9 | 4054 | trace_parser_clear(parser); |
7c088b51 | 4055 | if (ret < 0) |
3f2367ba | 4056 | goto out; |
eda1e328 | 4057 | } |
5072c59f | 4058 | |
5072c59f | 4059 | ret = read; |
3f2367ba | 4060 | out: |
5072c59f SR |
4061 | return ret; |
4062 | } | |
4063 | ||
fc13cb0c | 4064 | ssize_t |
41c52c0d SR |
4065 | ftrace_filter_write(struct file *file, const char __user *ubuf, |
4066 | size_t cnt, loff_t *ppos) | |
4067 | { | |
4068 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
4069 | } | |
4070 | ||
fc13cb0c | 4071 | ssize_t |
41c52c0d SR |
4072 | ftrace_notrace_write(struct file *file, const char __user *ubuf, |
4073 | size_t cnt, loff_t *ppos) | |
4074 | { | |
4075 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
4076 | } | |
4077 | ||
33dc9b12 | 4078 | static int |
647664ea MH |
4079 | ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) |
4080 | { | |
4081 | struct ftrace_func_entry *entry; | |
4082 | ||
4083 | if (!ftrace_location(ip)) | |
4084 | return -EINVAL; | |
4085 | ||
4086 | if (remove) { | |
4087 | entry = ftrace_lookup_ip(hash, ip); | |
4088 | if (!entry) | |
4089 | return -ENOENT; | |
4090 | free_hash_entry(hash, entry); | |
4091 | return 0; | |
4092 | } | |
4093 | ||
4094 | return add_hash_entry(hash, ip); | |
4095 | } | |
4096 | ||
8252ecf3 | 4097 | static void ftrace_ops_update_code(struct ftrace_ops *ops, |
7485058e | 4098 | struct ftrace_ops_hash *old_hash) |
1c80c432 | 4099 | { |
8f86f837 SRRH |
4100 | struct ftrace_ops *op; |
4101 | ||
4102 | if (!ftrace_enabled) | |
4103 | return; | |
4104 | ||
4105 | if (ops->flags & FTRACE_OPS_FL_ENABLED) { | |
8252ecf3 | 4106 | ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash); |
8f86f837 SRRH |
4107 | return; |
4108 | } | |
4109 | ||
4110 | /* | |
4111 | * If this is the shared global_ops filter, then we need to | |
4112 | * check if there is another ops that shares it, is enabled. | |
4113 | * If so, we still need to run the modify code. | |
4114 | */ | |
4115 | if (ops->func_hash != &global_ops.local_hash) | |
4116 | return; | |
4117 | ||
4118 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
4119 | if (op->func_hash == &global_ops.local_hash && | |
4120 | op->flags & FTRACE_OPS_FL_ENABLED) { | |
4121 | ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash); | |
4122 | /* Only need to do this once */ | |
4123 | return; | |
4124 | } | |
4125 | } while_for_each_ftrace_op(op); | |
1c80c432 SRRH |
4126 | } |
4127 | ||
647664ea MH |
4128 | static int |
4129 | ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, | |
4130 | unsigned long ip, int remove, int reset, int enable) | |
41c52c0d | 4131 | { |
33dc9b12 | 4132 | struct ftrace_hash **orig_hash; |
7485058e | 4133 | struct ftrace_ops_hash old_hash_ops; |
3296fc4e | 4134 | struct ftrace_hash *old_hash; |
f45948e8 | 4135 | struct ftrace_hash *hash; |
33dc9b12 | 4136 | int ret; |
f45948e8 | 4137 | |
41c52c0d | 4138 | if (unlikely(ftrace_disabled)) |
33dc9b12 | 4139 | return -ENODEV; |
41c52c0d | 4140 | |
33b7f99c | 4141 | mutex_lock(&ops->func_hash->regex_lock); |
3f2367ba | 4142 | |
f45948e8 | 4143 | if (enable) |
33b7f99c | 4144 | orig_hash = &ops->func_hash->filter_hash; |
f45948e8 | 4145 | else |
33b7f99c | 4146 | orig_hash = &ops->func_hash->notrace_hash; |
33dc9b12 | 4147 | |
b972cc58 WN |
4148 | if (reset) |
4149 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); | |
4150 | else | |
4151 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
4152 | ||
3f2367ba MH |
4153 | if (!hash) { |
4154 | ret = -ENOMEM; | |
4155 | goto out_regex_unlock; | |
4156 | } | |
f45948e8 | 4157 | |
ac483c44 JO |
4158 | if (buf && !ftrace_match_records(hash, buf, len)) { |
4159 | ret = -EINVAL; | |
4160 | goto out_regex_unlock; | |
4161 | } | |
647664ea MH |
4162 | if (ip) { |
4163 | ret = ftrace_match_addr(hash, ip, remove); | |
4164 | if (ret < 0) | |
4165 | goto out_regex_unlock; | |
4166 | } | |
33dc9b12 SR |
4167 | |
4168 | mutex_lock(&ftrace_lock); | |
3296fc4e | 4169 | old_hash = *orig_hash; |
7485058e SRRH |
4170 | old_hash_ops.filter_hash = ops->func_hash->filter_hash; |
4171 | old_hash_ops.notrace_hash = ops->func_hash->notrace_hash; | |
41fb61c2 | 4172 | ret = ftrace_hash_move(ops, enable, orig_hash, hash); |
3296fc4e | 4173 | if (!ret) { |
7485058e | 4174 | ftrace_ops_update_code(ops, &old_hash_ops); |
3296fc4e SRRH |
4175 | free_ftrace_hash_rcu(old_hash); |
4176 | } | |
33dc9b12 SR |
4177 | mutex_unlock(&ftrace_lock); |
4178 | ||
ac483c44 | 4179 | out_regex_unlock: |
33b7f99c | 4180 | mutex_unlock(&ops->func_hash->regex_lock); |
33dc9b12 SR |
4181 | |
4182 | free_ftrace_hash(hash); | |
4183 | return ret; | |
41c52c0d SR |
4184 | } |
4185 | ||
647664ea MH |
4186 | static int |
4187 | ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove, | |
4188 | int reset, int enable) | |
4189 | { | |
4190 | return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable); | |
4191 | } | |
4192 | ||
4193 | /** | |
4194 | * ftrace_set_filter_ip - set a function to filter on in ftrace by address | |
4195 | * @ops - the ops to set the filter with | |
4196 | * @ip - the address to add to or remove from the filter. | |
4197 | * @remove - non zero to remove the ip from the filter | |
4198 | * @reset - non zero to reset all filters before applying this filter. | |
4199 | * | |
4200 | * Filters denote which functions should be enabled when tracing is enabled | |
4201 | * If @ip is NULL, it failes to update filter. | |
4202 | */ | |
4203 | int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, | |
4204 | int remove, int reset) | |
4205 | { | |
f04f24fb | 4206 | ftrace_ops_init(ops); |
647664ea MH |
4207 | return ftrace_set_addr(ops, ip, remove, reset, 1); |
4208 | } | |
4209 | EXPORT_SYMBOL_GPL(ftrace_set_filter_ip); | |
4210 | ||
4211 | static int | |
4212 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, | |
4213 | int reset, int enable) | |
4214 | { | |
4215 | return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable); | |
4216 | } | |
4217 | ||
77a2b37d SR |
4218 | /** |
4219 | * ftrace_set_filter - set a function to filter on in ftrace | |
936e074b SR |
4220 | * @ops - the ops to set the filter with |
4221 | * @buf - the string that holds the function filter text. | |
4222 | * @len - the length of the string. | |
4223 | * @reset - non zero to reset all filters before applying this filter. | |
4224 | * | |
4225 | * Filters denote which functions should be enabled when tracing is enabled. | |
4226 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
4227 | */ | |
ac483c44 | 4228 | int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
4229 | int len, int reset) |
4230 | { | |
f04f24fb | 4231 | ftrace_ops_init(ops); |
ac483c44 | 4232 | return ftrace_set_regex(ops, buf, len, reset, 1); |
936e074b SR |
4233 | } |
4234 | EXPORT_SYMBOL_GPL(ftrace_set_filter); | |
4235 | ||
4236 | /** | |
4237 | * ftrace_set_notrace - set a function to not trace in ftrace | |
4238 | * @ops - the ops to set the notrace filter with | |
4239 | * @buf - the string that holds the function notrace text. | |
4240 | * @len - the length of the string. | |
4241 | * @reset - non zero to reset all filters before applying this filter. | |
4242 | * | |
4243 | * Notrace Filters denote which functions should not be enabled when tracing | |
4244 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
4245 | * for tracing. | |
4246 | */ | |
ac483c44 | 4247 | int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
4248 | int len, int reset) |
4249 | { | |
f04f24fb | 4250 | ftrace_ops_init(ops); |
ac483c44 | 4251 | return ftrace_set_regex(ops, buf, len, reset, 0); |
936e074b SR |
4252 | } |
4253 | EXPORT_SYMBOL_GPL(ftrace_set_notrace); | |
4254 | /** | |
8d1b065d | 4255 | * ftrace_set_global_filter - set a function to filter on with global tracers |
77a2b37d SR |
4256 | * @buf - the string that holds the function filter text. |
4257 | * @len - the length of the string. | |
4258 | * @reset - non zero to reset all filters before applying this filter. | |
4259 | * | |
4260 | * Filters denote which functions should be enabled when tracing is enabled. | |
4261 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
4262 | */ | |
936e074b | 4263 | void ftrace_set_global_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 4264 | { |
f45948e8 | 4265 | ftrace_set_regex(&global_ops, buf, len, reset, 1); |
41c52c0d | 4266 | } |
936e074b | 4267 | EXPORT_SYMBOL_GPL(ftrace_set_global_filter); |
4eebcc81 | 4268 | |
41c52c0d | 4269 | /** |
8d1b065d | 4270 | * ftrace_set_global_notrace - set a function to not trace with global tracers |
41c52c0d SR |
4271 | * @buf - the string that holds the function notrace text. |
4272 | * @len - the length of the string. | |
4273 | * @reset - non zero to reset all filters before applying this filter. | |
4274 | * | |
4275 | * Notrace Filters denote which functions should not be enabled when tracing | |
4276 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
4277 | * for tracing. | |
4278 | */ | |
936e074b | 4279 | void ftrace_set_global_notrace(unsigned char *buf, int len, int reset) |
41c52c0d | 4280 | { |
f45948e8 | 4281 | ftrace_set_regex(&global_ops, buf, len, reset, 0); |
77a2b37d | 4282 | } |
936e074b | 4283 | EXPORT_SYMBOL_GPL(ftrace_set_global_notrace); |
77a2b37d | 4284 | |
2af15d6a SR |
4285 | /* |
4286 | * command line interface to allow users to set filters on boot up. | |
4287 | */ | |
4288 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
4289 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
4290 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
4291 | ||
f1ed7c74 SRRH |
4292 | /* Used by function selftest to not test if filter is set */ |
4293 | bool ftrace_filter_param __initdata; | |
4294 | ||
2af15d6a SR |
4295 | static int __init set_ftrace_notrace(char *str) |
4296 | { | |
f1ed7c74 | 4297 | ftrace_filter_param = true; |
75761cc1 | 4298 | strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
4299 | return 1; |
4300 | } | |
4301 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
4302 | ||
4303 | static int __init set_ftrace_filter(char *str) | |
4304 | { | |
f1ed7c74 | 4305 | ftrace_filter_param = true; |
75761cc1 | 4306 | strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
4307 | return 1; |
4308 | } | |
4309 | __setup("ftrace_filter=", set_ftrace_filter); | |
4310 | ||
369bc18f | 4311 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 4312 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
0d7d9a16 | 4313 | static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata; |
faf982a6 | 4314 | static int ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer); |
801c29fd | 4315 | |
f3bea491 SRRH |
4316 | static unsigned long save_global_trampoline; |
4317 | static unsigned long save_global_flags; | |
4318 | ||
369bc18f SA |
4319 | static int __init set_graph_function(char *str) |
4320 | { | |
06f43d66 | 4321 | strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
4322 | return 1; |
4323 | } | |
4324 | __setup("ftrace_graph_filter=", set_graph_function); | |
4325 | ||
0d7d9a16 NK |
4326 | static int __init set_graph_notrace_function(char *str) |
4327 | { | |
4328 | strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE); | |
4329 | return 1; | |
4330 | } | |
4331 | __setup("ftrace_graph_notrace=", set_graph_notrace_function); | |
4332 | ||
4333 | static void __init set_ftrace_early_graph(char *buf, int enable) | |
369bc18f SA |
4334 | { |
4335 | int ret; | |
4336 | char *func; | |
0d7d9a16 NK |
4337 | unsigned long *table = ftrace_graph_funcs; |
4338 | int *count = &ftrace_graph_count; | |
4339 | ||
4340 | if (!enable) { | |
4341 | table = ftrace_graph_notrace_funcs; | |
4342 | count = &ftrace_graph_notrace_count; | |
4343 | } | |
369bc18f SA |
4344 | |
4345 | while (buf) { | |
4346 | func = strsep(&buf, ","); | |
4347 | /* we allow only one expression at a time */ | |
0d7d9a16 | 4348 | ret = ftrace_set_func(table, count, FTRACE_GRAPH_MAX_FUNCS, func); |
369bc18f SA |
4349 | if (ret) |
4350 | printk(KERN_DEBUG "ftrace: function %s not " | |
4351 | "traceable\n", func); | |
4352 | } | |
4353 | } | |
4354 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
4355 | ||
2a85a37f SR |
4356 | void __init |
4357 | ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable) | |
2af15d6a SR |
4358 | { |
4359 | char *func; | |
4360 | ||
f04f24fb MH |
4361 | ftrace_ops_init(ops); |
4362 | ||
2af15d6a SR |
4363 | while (buf) { |
4364 | func = strsep(&buf, ","); | |
f45948e8 | 4365 | ftrace_set_regex(ops, func, strlen(func), 0, enable); |
2af15d6a SR |
4366 | } |
4367 | } | |
4368 | ||
4369 | static void __init set_ftrace_early_filters(void) | |
4370 | { | |
4371 | if (ftrace_filter_buf[0]) | |
2a85a37f | 4372 | ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1); |
2af15d6a | 4373 | if (ftrace_notrace_buf[0]) |
2a85a37f | 4374 | ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0); |
369bc18f SA |
4375 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
4376 | if (ftrace_graph_buf[0]) | |
0d7d9a16 NK |
4377 | set_ftrace_early_graph(ftrace_graph_buf, 1); |
4378 | if (ftrace_graph_notrace_buf[0]) | |
4379 | set_ftrace_early_graph(ftrace_graph_notrace_buf, 0); | |
369bc18f | 4380 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
2af15d6a SR |
4381 | } |
4382 | ||
fc13cb0c | 4383 | int ftrace_regex_release(struct inode *inode, struct file *file) |
5072c59f SR |
4384 | { |
4385 | struct seq_file *m = (struct seq_file *)file->private_data; | |
7485058e | 4386 | struct ftrace_ops_hash old_hash_ops; |
5072c59f | 4387 | struct ftrace_iterator *iter; |
33dc9b12 | 4388 | struct ftrace_hash **orig_hash; |
3296fc4e | 4389 | struct ftrace_hash *old_hash; |
689fd8b6 | 4390 | struct trace_parser *parser; |
ed926f9b | 4391 | int filter_hash; |
33dc9b12 | 4392 | int ret; |
5072c59f | 4393 | |
5072c59f SR |
4394 | if (file->f_mode & FMODE_READ) { |
4395 | iter = m->private; | |
5072c59f SR |
4396 | seq_release(inode, file); |
4397 | } else | |
4398 | iter = file->private_data; | |
4399 | ||
689fd8b6 | 4400 | parser = &iter->parser; |
4401 | if (trace_parser_loaded(parser)) { | |
4402 | parser->buffer[parser->idx] = 0; | |
1cf41dd7 | 4403 | ftrace_match_records(iter->hash, parser->buffer, parser->idx); |
5072c59f SR |
4404 | } |
4405 | ||
689fd8b6 | 4406 | trace_parser_put(parser); |
689fd8b6 | 4407 | |
33b7f99c | 4408 | mutex_lock(&iter->ops->func_hash->regex_lock); |
3f2367ba | 4409 | |
058e297d | 4410 | if (file->f_mode & FMODE_WRITE) { |
ed926f9b SR |
4411 | filter_hash = !!(iter->flags & FTRACE_ITER_FILTER); |
4412 | ||
4413 | if (filter_hash) | |
33b7f99c | 4414 | orig_hash = &iter->ops->func_hash->filter_hash; |
ed926f9b | 4415 | else |
33b7f99c | 4416 | orig_hash = &iter->ops->func_hash->notrace_hash; |
33dc9b12 | 4417 | |
058e297d | 4418 | mutex_lock(&ftrace_lock); |
3296fc4e | 4419 | old_hash = *orig_hash; |
7485058e SRRH |
4420 | old_hash_ops.filter_hash = iter->ops->func_hash->filter_hash; |
4421 | old_hash_ops.notrace_hash = iter->ops->func_hash->notrace_hash; | |
41fb61c2 SR |
4422 | ret = ftrace_hash_move(iter->ops, filter_hash, |
4423 | orig_hash, iter->hash); | |
3296fc4e | 4424 | if (!ret) { |
7485058e | 4425 | ftrace_ops_update_code(iter->ops, &old_hash_ops); |
3296fc4e SRRH |
4426 | free_ftrace_hash_rcu(old_hash); |
4427 | } | |
058e297d SR |
4428 | mutex_unlock(&ftrace_lock); |
4429 | } | |
3f2367ba | 4430 | |
33b7f99c | 4431 | mutex_unlock(&iter->ops->func_hash->regex_lock); |
33dc9b12 SR |
4432 | free_ftrace_hash(iter->hash); |
4433 | kfree(iter); | |
058e297d | 4434 | |
5072c59f SR |
4435 | return 0; |
4436 | } | |
4437 | ||
5e2336a0 | 4438 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
4439 | .open = ftrace_avail_open, |
4440 | .read = seq_read, | |
4441 | .llseek = seq_lseek, | |
3be04b47 | 4442 | .release = seq_release_private, |
5072c59f SR |
4443 | }; |
4444 | ||
647bcd03 SR |
4445 | static const struct file_operations ftrace_enabled_fops = { |
4446 | .open = ftrace_enabled_open, | |
4447 | .read = seq_read, | |
4448 | .llseek = seq_lseek, | |
4449 | .release = seq_release_private, | |
4450 | }; | |
4451 | ||
5e2336a0 | 4452 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 4453 | .open = ftrace_filter_open, |
850a80cf | 4454 | .read = seq_read, |
5072c59f | 4455 | .write = ftrace_filter_write, |
098c879e | 4456 | .llseek = tracing_lseek, |
1cf41dd7 | 4457 | .release = ftrace_regex_release, |
5072c59f SR |
4458 | }; |
4459 | ||
5e2336a0 | 4460 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 4461 | .open = ftrace_notrace_open, |
850a80cf | 4462 | .read = seq_read, |
41c52c0d | 4463 | .write = ftrace_notrace_write, |
098c879e | 4464 | .llseek = tracing_lseek, |
1cf41dd7 | 4465 | .release = ftrace_regex_release, |
41c52c0d SR |
4466 | }; |
4467 | ||
ea4e2bc4 SR |
4468 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
4469 | ||
4470 | static DEFINE_MUTEX(graph_lock); | |
4471 | ||
4472 | int ftrace_graph_count; | |
29ad23b0 | 4473 | int ftrace_graph_notrace_count; |
ea4e2bc4 | 4474 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
29ad23b0 | 4475 | unsigned long ftrace_graph_notrace_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
ea4e2bc4 | 4476 | |
faf982a6 NK |
4477 | struct ftrace_graph_data { |
4478 | unsigned long *table; | |
4479 | size_t size; | |
4480 | int *count; | |
4481 | const struct seq_operations *seq_ops; | |
4482 | }; | |
4483 | ||
ea4e2bc4 | 4484 | static void * |
85951842 | 4485 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 4486 | { |
faf982a6 NK |
4487 | struct ftrace_graph_data *fgd = m->private; |
4488 | ||
4489 | if (*pos >= *fgd->count) | |
ea4e2bc4 | 4490 | return NULL; |
faf982a6 | 4491 | return &fgd->table[*pos]; |
85951842 | 4492 | } |
ea4e2bc4 | 4493 | |
85951842 LZ |
4494 | static void * |
4495 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
4496 | { | |
4497 | (*pos)++; | |
4498 | return __g_next(m, pos); | |
ea4e2bc4 SR |
4499 | } |
4500 | ||
4501 | static void *g_start(struct seq_file *m, loff_t *pos) | |
4502 | { | |
faf982a6 NK |
4503 | struct ftrace_graph_data *fgd = m->private; |
4504 | ||
ea4e2bc4 SR |
4505 | mutex_lock(&graph_lock); |
4506 | ||
f9349a8f | 4507 | /* Nothing, tell g_show to print all functions are enabled */ |
faf982a6 | 4508 | if (!*fgd->count && !*pos) |
f9349a8f FW |
4509 | return (void *)1; |
4510 | ||
85951842 | 4511 | return __g_next(m, pos); |
ea4e2bc4 SR |
4512 | } |
4513 | ||
4514 | static void g_stop(struct seq_file *m, void *p) | |
4515 | { | |
4516 | mutex_unlock(&graph_lock); | |
4517 | } | |
4518 | ||
4519 | static int g_show(struct seq_file *m, void *v) | |
4520 | { | |
4521 | unsigned long *ptr = v; | |
ea4e2bc4 SR |
4522 | |
4523 | if (!ptr) | |
4524 | return 0; | |
4525 | ||
f9349a8f | 4526 | if (ptr == (unsigned long *)1) { |
280d1429 NK |
4527 | struct ftrace_graph_data *fgd = m->private; |
4528 | ||
4529 | if (fgd->table == ftrace_graph_funcs) | |
fa6f0cc7 | 4530 | seq_puts(m, "#### all functions enabled ####\n"); |
280d1429 | 4531 | else |
fa6f0cc7 | 4532 | seq_puts(m, "#### no functions disabled ####\n"); |
f9349a8f FW |
4533 | return 0; |
4534 | } | |
4535 | ||
b375a11a | 4536 | seq_printf(m, "%ps\n", (void *)*ptr); |
ea4e2bc4 SR |
4537 | |
4538 | return 0; | |
4539 | } | |
4540 | ||
88e9d34c | 4541 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
4542 | .start = g_start, |
4543 | .next = g_next, | |
4544 | .stop = g_stop, | |
4545 | .show = g_show, | |
4546 | }; | |
4547 | ||
4548 | static int | |
faf982a6 NK |
4549 | __ftrace_graph_open(struct inode *inode, struct file *file, |
4550 | struct ftrace_graph_data *fgd) | |
ea4e2bc4 SR |
4551 | { |
4552 | int ret = 0; | |
4553 | ||
ea4e2bc4 SR |
4554 | mutex_lock(&graph_lock); |
4555 | if ((file->f_mode & FMODE_WRITE) && | |
8650ae32 | 4556 | (file->f_flags & O_TRUNC)) { |
faf982a6 NK |
4557 | *fgd->count = 0; |
4558 | memset(fgd->table, 0, fgd->size * sizeof(*fgd->table)); | |
ea4e2bc4 | 4559 | } |
a4ec5e0c | 4560 | mutex_unlock(&graph_lock); |
ea4e2bc4 | 4561 | |
faf982a6 NK |
4562 | if (file->f_mode & FMODE_READ) { |
4563 | ret = seq_open(file, fgd->seq_ops); | |
4564 | if (!ret) { | |
4565 | struct seq_file *m = file->private_data; | |
4566 | m->private = fgd; | |
4567 | } | |
4568 | } else | |
4569 | file->private_data = fgd; | |
ea4e2bc4 SR |
4570 | |
4571 | return ret; | |
4572 | } | |
4573 | ||
faf982a6 NK |
4574 | static int |
4575 | ftrace_graph_open(struct inode *inode, struct file *file) | |
4576 | { | |
4577 | struct ftrace_graph_data *fgd; | |
4578 | ||
4579 | if (unlikely(ftrace_disabled)) | |
4580 | return -ENODEV; | |
4581 | ||
4582 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
4583 | if (fgd == NULL) | |
4584 | return -ENOMEM; | |
4585 | ||
4586 | fgd->table = ftrace_graph_funcs; | |
4587 | fgd->size = FTRACE_GRAPH_MAX_FUNCS; | |
4588 | fgd->count = &ftrace_graph_count; | |
4589 | fgd->seq_ops = &ftrace_graph_seq_ops; | |
4590 | ||
4591 | return __ftrace_graph_open(inode, file, fgd); | |
4592 | } | |
4593 | ||
29ad23b0 NK |
4594 | static int |
4595 | ftrace_graph_notrace_open(struct inode *inode, struct file *file) | |
4596 | { | |
4597 | struct ftrace_graph_data *fgd; | |
4598 | ||
4599 | if (unlikely(ftrace_disabled)) | |
4600 | return -ENODEV; | |
4601 | ||
4602 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
4603 | if (fgd == NULL) | |
4604 | return -ENOMEM; | |
4605 | ||
4606 | fgd->table = ftrace_graph_notrace_funcs; | |
4607 | fgd->size = FTRACE_GRAPH_MAX_FUNCS; | |
4608 | fgd->count = &ftrace_graph_notrace_count; | |
4609 | fgd->seq_ops = &ftrace_graph_seq_ops; | |
4610 | ||
4611 | return __ftrace_graph_open(inode, file, fgd); | |
4612 | } | |
4613 | ||
87827111 LZ |
4614 | static int |
4615 | ftrace_graph_release(struct inode *inode, struct file *file) | |
4616 | { | |
faf982a6 NK |
4617 | if (file->f_mode & FMODE_READ) { |
4618 | struct seq_file *m = file->private_data; | |
4619 | ||
4620 | kfree(m->private); | |
87827111 | 4621 | seq_release(inode, file); |
faf982a6 NK |
4622 | } else { |
4623 | kfree(file->private_data); | |
4624 | } | |
4625 | ||
87827111 LZ |
4626 | return 0; |
4627 | } | |
4628 | ||
ea4e2bc4 | 4629 | static int |
faf982a6 | 4630 | ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer) |
ea4e2bc4 | 4631 | { |
3ba00929 | 4632 | struct ftrace_glob func_g; |
ea4e2bc4 SR |
4633 | struct dyn_ftrace *rec; |
4634 | struct ftrace_page *pg; | |
c7c6b1fe | 4635 | int fail = 1; |
3ba00929 | 4636 | int not; |
f9349a8f FW |
4637 | bool exists; |
4638 | int i; | |
ea4e2bc4 | 4639 | |
f9349a8f | 4640 | /* decode regex */ |
3ba00929 DS |
4641 | func_g.type = filter_parse_regex(buffer, strlen(buffer), |
4642 | &func_g.search, ¬); | |
faf982a6 | 4643 | if (!not && *idx >= size) |
c7c6b1fe | 4644 | return -EBUSY; |
f9349a8f | 4645 | |
3ba00929 | 4646 | func_g.len = strlen(func_g.search); |
f9349a8f | 4647 | |
52baf119 | 4648 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
4649 | |
4650 | if (unlikely(ftrace_disabled)) { | |
4651 | mutex_unlock(&ftrace_lock); | |
4652 | return -ENODEV; | |
4653 | } | |
4654 | ||
265c831c SR |
4655 | do_for_each_ftrace_rec(pg, rec) { |
4656 | ||
0b507e1e | 4657 | if (ftrace_match_record(rec, &func_g, NULL, 0)) { |
c7c6b1fe | 4658 | /* if it is in the array */ |
f9349a8f | 4659 | exists = false; |
c7c6b1fe | 4660 | for (i = 0; i < *idx; i++) { |
f9349a8f FW |
4661 | if (array[i] == rec->ip) { |
4662 | exists = true; | |
265c831c SR |
4663 | break; |
4664 | } | |
c7c6b1fe LZ |
4665 | } |
4666 | ||
4667 | if (!not) { | |
4668 | fail = 0; | |
4669 | if (!exists) { | |
4670 | array[(*idx)++] = rec->ip; | |
faf982a6 | 4671 | if (*idx >= size) |
c7c6b1fe LZ |
4672 | goto out; |
4673 | } | |
4674 | } else { | |
4675 | if (exists) { | |
4676 | array[i] = array[--(*idx)]; | |
4677 | array[*idx] = 0; | |
4678 | fail = 0; | |
4679 | } | |
4680 | } | |
ea4e2bc4 | 4681 | } |
265c831c | 4682 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 4683 | out: |
52baf119 | 4684 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 4685 | |
c7c6b1fe LZ |
4686 | if (fail) |
4687 | return -EINVAL; | |
4688 | ||
c7c6b1fe | 4689 | return 0; |
ea4e2bc4 SR |
4690 | } |
4691 | ||
4692 | static ssize_t | |
4693 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
4694 | size_t cnt, loff_t *ppos) | |
4695 | { | |
689fd8b6 | 4696 | struct trace_parser parser; |
6a10108b | 4697 | ssize_t read, ret = 0; |
faf982a6 | 4698 | struct ftrace_graph_data *fgd = file->private_data; |
ea4e2bc4 | 4699 | |
c7c6b1fe | 4700 | if (!cnt) |
ea4e2bc4 SR |
4701 | return 0; |
4702 | ||
6a10108b NK |
4703 | if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) |
4704 | return -ENOMEM; | |
ea4e2bc4 | 4705 | |
689fd8b6 | 4706 | read = trace_get_user(&parser, ubuf, cnt, ppos); |
ea4e2bc4 | 4707 | |
4ba7978e | 4708 | if (read >= 0 && trace_parser_loaded((&parser))) { |
689fd8b6 | 4709 | parser.buffer[parser.idx] = 0; |
4710 | ||
6a10108b NK |
4711 | mutex_lock(&graph_lock); |
4712 | ||
689fd8b6 | 4713 | /* we allow only one expression at a time */ |
faf982a6 NK |
4714 | ret = ftrace_set_func(fgd->table, fgd->count, fgd->size, |
4715 | parser.buffer); | |
6a10108b NK |
4716 | |
4717 | mutex_unlock(&graph_lock); | |
ea4e2bc4 | 4718 | } |
ea4e2bc4 | 4719 | |
6a10108b NK |
4720 | if (!ret) |
4721 | ret = read; | |
1eb90f13 | 4722 | |
689fd8b6 | 4723 | trace_parser_put(&parser); |
ea4e2bc4 SR |
4724 | |
4725 | return ret; | |
4726 | } | |
4727 | ||
4728 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
4729 | .open = ftrace_graph_open, |
4730 | .read = seq_read, | |
4731 | .write = ftrace_graph_write, | |
098c879e | 4732 | .llseek = tracing_lseek, |
87827111 | 4733 | .release = ftrace_graph_release, |
ea4e2bc4 | 4734 | }; |
29ad23b0 NK |
4735 | |
4736 | static const struct file_operations ftrace_graph_notrace_fops = { | |
4737 | .open = ftrace_graph_notrace_open, | |
4738 | .read = seq_read, | |
4739 | .write = ftrace_graph_write, | |
098c879e | 4740 | .llseek = tracing_lseek, |
29ad23b0 NK |
4741 | .release = ftrace_graph_release, |
4742 | }; | |
ea4e2bc4 SR |
4743 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
4744 | ||
591dffda SRRH |
4745 | void ftrace_create_filter_files(struct ftrace_ops *ops, |
4746 | struct dentry *parent) | |
4747 | { | |
4748 | ||
4749 | trace_create_file("set_ftrace_filter", 0644, parent, | |
4750 | ops, &ftrace_filter_fops); | |
4751 | ||
4752 | trace_create_file("set_ftrace_notrace", 0644, parent, | |
4753 | ops, &ftrace_notrace_fops); | |
4754 | } | |
4755 | ||
4756 | /* | |
4757 | * The name "destroy_filter_files" is really a misnomer. Although | |
4758 | * in the future, it may actualy delete the files, but this is | |
4759 | * really intended to make sure the ops passed in are disabled | |
4760 | * and that when this function returns, the caller is free to | |
4761 | * free the ops. | |
4762 | * | |
4763 | * The "destroy" name is only to match the "create" name that this | |
4764 | * should be paired with. | |
4765 | */ | |
4766 | void ftrace_destroy_filter_files(struct ftrace_ops *ops) | |
4767 | { | |
4768 | mutex_lock(&ftrace_lock); | |
4769 | if (ops->flags & FTRACE_OPS_FL_ENABLED) | |
4770 | ftrace_shutdown(ops, 0); | |
4771 | ops->flags |= FTRACE_OPS_FL_DELETED; | |
4772 | mutex_unlock(&ftrace_lock); | |
4773 | } | |
4774 | ||
8434dc93 | 4775 | static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer) |
5072c59f | 4776 | { |
5072c59f | 4777 | |
5452af66 FW |
4778 | trace_create_file("available_filter_functions", 0444, |
4779 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 4780 | |
647bcd03 SR |
4781 | trace_create_file("enabled_functions", 0444, |
4782 | d_tracer, NULL, &ftrace_enabled_fops); | |
4783 | ||
591dffda | 4784 | ftrace_create_filter_files(&global_ops, d_tracer); |
ad90c0e3 | 4785 | |
ea4e2bc4 | 4786 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5452af66 | 4787 | trace_create_file("set_graph_function", 0444, d_tracer, |
ea4e2bc4 SR |
4788 | NULL, |
4789 | &ftrace_graph_fops); | |
29ad23b0 NK |
4790 | trace_create_file("set_graph_notrace", 0444, d_tracer, |
4791 | NULL, | |
4792 | &ftrace_graph_notrace_fops); | |
ea4e2bc4 SR |
4793 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
4794 | ||
5072c59f SR |
4795 | return 0; |
4796 | } | |
4797 | ||
9fd49328 | 4798 | static int ftrace_cmp_ips(const void *a, const void *b) |
68950619 | 4799 | { |
9fd49328 SR |
4800 | const unsigned long *ipa = a; |
4801 | const unsigned long *ipb = b; | |
68950619 | 4802 | |
9fd49328 SR |
4803 | if (*ipa > *ipb) |
4804 | return 1; | |
4805 | if (*ipa < *ipb) | |
4806 | return -1; | |
4807 | return 0; | |
4808 | } | |
4809 | ||
5cb084bb | 4810 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 4811 | unsigned long *start, |
68bf21aa SR |
4812 | unsigned long *end) |
4813 | { | |
706c81f8 | 4814 | struct ftrace_page *start_pg; |
a7900875 | 4815 | struct ftrace_page *pg; |
706c81f8 | 4816 | struct dyn_ftrace *rec; |
a7900875 | 4817 | unsigned long count; |
68bf21aa SR |
4818 | unsigned long *p; |
4819 | unsigned long addr; | |
4376cac6 | 4820 | unsigned long flags = 0; /* Shut up gcc */ |
a7900875 SR |
4821 | int ret = -ENOMEM; |
4822 | ||
4823 | count = end - start; | |
4824 | ||
4825 | if (!count) | |
4826 | return 0; | |
4827 | ||
9fd49328 | 4828 | sort(start, count, sizeof(*start), |
6db02903 | 4829 | ftrace_cmp_ips, NULL); |
9fd49328 | 4830 | |
706c81f8 SR |
4831 | start_pg = ftrace_allocate_pages(count); |
4832 | if (!start_pg) | |
a7900875 | 4833 | return -ENOMEM; |
68bf21aa | 4834 | |
e6ea44e9 | 4835 | mutex_lock(&ftrace_lock); |
a7900875 | 4836 | |
32082309 SR |
4837 | /* |
4838 | * Core and each module needs their own pages, as | |
4839 | * modules will free them when they are removed. | |
4840 | * Force a new page to be allocated for modules. | |
4841 | */ | |
a7900875 SR |
4842 | if (!mod) { |
4843 | WARN_ON(ftrace_pages || ftrace_pages_start); | |
4844 | /* First initialization */ | |
706c81f8 | 4845 | ftrace_pages = ftrace_pages_start = start_pg; |
a7900875 | 4846 | } else { |
32082309 | 4847 | if (!ftrace_pages) |
a7900875 | 4848 | goto out; |
32082309 | 4849 | |
a7900875 SR |
4850 | if (WARN_ON(ftrace_pages->next)) { |
4851 | /* Hmm, we have free pages? */ | |
4852 | while (ftrace_pages->next) | |
4853 | ftrace_pages = ftrace_pages->next; | |
32082309 | 4854 | } |
a7900875 | 4855 | |
706c81f8 | 4856 | ftrace_pages->next = start_pg; |
32082309 SR |
4857 | } |
4858 | ||
68bf21aa | 4859 | p = start; |
706c81f8 | 4860 | pg = start_pg; |
68bf21aa SR |
4861 | while (p < end) { |
4862 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
4863 | /* |
4864 | * Some architecture linkers will pad between | |
4865 | * the different mcount_loc sections of different | |
4866 | * object files to satisfy alignments. | |
4867 | * Skip any NULL pointers. | |
4868 | */ | |
4869 | if (!addr) | |
4870 | continue; | |
706c81f8 SR |
4871 | |
4872 | if (pg->index == pg->size) { | |
4873 | /* We should have allocated enough */ | |
4874 | if (WARN_ON(!pg->next)) | |
4875 | break; | |
4876 | pg = pg->next; | |
4877 | } | |
4878 | ||
4879 | rec = &pg->records[pg->index++]; | |
4880 | rec->ip = addr; | |
68bf21aa SR |
4881 | } |
4882 | ||
706c81f8 SR |
4883 | /* We should have used all pages */ |
4884 | WARN_ON(pg->next); | |
4885 | ||
4886 | /* Assign the last page to ftrace_pages */ | |
4887 | ftrace_pages = pg; | |
4888 | ||
a4f18ed1 | 4889 | /* |
4376cac6 SR |
4890 | * We only need to disable interrupts on start up |
4891 | * because we are modifying code that an interrupt | |
4892 | * may execute, and the modification is not atomic. | |
4893 | * But for modules, nothing runs the code we modify | |
4894 | * until we are finished with it, and there's no | |
4895 | * reason to cause large interrupt latencies while we do it. | |
a4f18ed1 | 4896 | */ |
4376cac6 SR |
4897 | if (!mod) |
4898 | local_irq_save(flags); | |
1dc43cf0 | 4899 | ftrace_update_code(mod, start_pg); |
4376cac6 SR |
4900 | if (!mod) |
4901 | local_irq_restore(flags); | |
a7900875 SR |
4902 | ret = 0; |
4903 | out: | |
e6ea44e9 | 4904 | mutex_unlock(&ftrace_lock); |
68bf21aa | 4905 | |
a7900875 | 4906 | return ret; |
68bf21aa SR |
4907 | } |
4908 | ||
93eb677d | 4909 | #ifdef CONFIG_MODULES |
32082309 SR |
4910 | |
4911 | #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next) | |
4912 | ||
b7ffffbb SRRH |
4913 | static int referenced_filters(struct dyn_ftrace *rec) |
4914 | { | |
4915 | struct ftrace_ops *ops; | |
4916 | int cnt = 0; | |
4917 | ||
4918 | for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) { | |
4919 | if (ops_references_rec(ops, rec)) | |
4920 | cnt++; | |
4921 | } | |
4922 | ||
4923 | return cnt; | |
4924 | } | |
4925 | ||
e7247a15 | 4926 | void ftrace_release_mod(struct module *mod) |
93eb677d SR |
4927 | { |
4928 | struct dyn_ftrace *rec; | |
32082309 | 4929 | struct ftrace_page **last_pg; |
93eb677d | 4930 | struct ftrace_page *pg; |
a7900875 | 4931 | int order; |
93eb677d | 4932 | |
45a4a237 SR |
4933 | mutex_lock(&ftrace_lock); |
4934 | ||
e7247a15 | 4935 | if (ftrace_disabled) |
45a4a237 | 4936 | goto out_unlock; |
93eb677d | 4937 | |
32082309 SR |
4938 | /* |
4939 | * Each module has its own ftrace_pages, remove | |
4940 | * them from the list. | |
4941 | */ | |
4942 | last_pg = &ftrace_pages_start; | |
4943 | for (pg = ftrace_pages_start; pg; pg = *last_pg) { | |
4944 | rec = &pg->records[0]; | |
e7247a15 | 4945 | if (within_module_core(rec->ip, mod)) { |
93eb677d | 4946 | /* |
32082309 SR |
4947 | * As core pages are first, the first |
4948 | * page should never be a module page. | |
93eb677d | 4949 | */ |
32082309 SR |
4950 | if (WARN_ON(pg == ftrace_pages_start)) |
4951 | goto out_unlock; | |
4952 | ||
4953 | /* Check if we are deleting the last page */ | |
4954 | if (pg == ftrace_pages) | |
4955 | ftrace_pages = next_to_ftrace_page(last_pg); | |
4956 | ||
4957 | *last_pg = pg->next; | |
a7900875 SR |
4958 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
4959 | free_pages((unsigned long)pg->records, order); | |
4960 | kfree(pg); | |
32082309 SR |
4961 | } else |
4962 | last_pg = &pg->next; | |
4963 | } | |
45a4a237 | 4964 | out_unlock: |
93eb677d SR |
4965 | mutex_unlock(&ftrace_lock); |
4966 | } | |
4967 | ||
7dcd182b | 4968 | void ftrace_module_enable(struct module *mod) |
b7ffffbb SRRH |
4969 | { |
4970 | struct dyn_ftrace *rec; | |
4971 | struct ftrace_page *pg; | |
4972 | ||
4973 | mutex_lock(&ftrace_lock); | |
4974 | ||
4975 | if (ftrace_disabled) | |
4976 | goto out_unlock; | |
4977 | ||
4978 | /* | |
4979 | * If the tracing is enabled, go ahead and enable the record. | |
4980 | * | |
4981 | * The reason not to enable the record immediatelly is the | |
4982 | * inherent check of ftrace_make_nop/ftrace_make_call for | |
4983 | * correct previous instructions. Making first the NOP | |
4984 | * conversion puts the module to the correct state, thus | |
4985 | * passing the ftrace_make_call check. | |
4986 | * | |
4987 | * We also delay this to after the module code already set the | |
4988 | * text to read-only, as we now need to set it back to read-write | |
4989 | * so that we can modify the text. | |
4990 | */ | |
4991 | if (ftrace_start_up) | |
4992 | ftrace_arch_code_modify_prepare(); | |
4993 | ||
4994 | do_for_each_ftrace_rec(pg, rec) { | |
4995 | int cnt; | |
4996 | /* | |
4997 | * do_for_each_ftrace_rec() is a double loop. | |
4998 | * module text shares the pg. If a record is | |
4999 | * not part of this module, then skip this pg, | |
5000 | * which the "break" will do. | |
5001 | */ | |
5002 | if (!within_module_core(rec->ip, mod)) | |
5003 | break; | |
5004 | ||
5005 | cnt = 0; | |
5006 | ||
5007 | /* | |
5008 | * When adding a module, we need to check if tracers are | |
5009 | * currently enabled and if they are, and can trace this record, | |
5010 | * we need to enable the module functions as well as update the | |
5011 | * reference counts for those function records. | |
5012 | */ | |
5013 | if (ftrace_start_up) | |
5014 | cnt += referenced_filters(rec); | |
5015 | ||
5016 | /* This clears FTRACE_FL_DISABLED */ | |
5017 | rec->flags = cnt; | |
5018 | ||
5019 | if (ftrace_start_up && cnt) { | |
5020 | int failed = __ftrace_replace_code(rec, 1); | |
5021 | if (failed) { | |
5022 | ftrace_bug(failed, rec); | |
5023 | goto out_loop; | |
5024 | } | |
5025 | } | |
5026 | ||
5027 | } while_for_each_ftrace_rec(); | |
5028 | ||
5029 | out_loop: | |
5030 | if (ftrace_start_up) | |
5031 | ftrace_arch_code_modify_post_process(); | |
5032 | ||
5033 | out_unlock: | |
5034 | mutex_unlock(&ftrace_lock); | |
5035 | } | |
5036 | ||
b6b71f66 | 5037 | void ftrace_module_init(struct module *mod) |
90d595fe | 5038 | { |
97e9b4fc | 5039 | if (ftrace_disabled || !mod->num_ftrace_callsites) |
fed1939c | 5040 | return; |
90d595fe | 5041 | |
97e9b4fc SRRH |
5042 | ftrace_process_locs(mod, mod->ftrace_callsites, |
5043 | mod->ftrace_callsites + mod->num_ftrace_callsites); | |
8c189ea6 | 5044 | } |
93eb677d SR |
5045 | #endif /* CONFIG_MODULES */ |
5046 | ||
68bf21aa SR |
5047 | void __init ftrace_init(void) |
5048 | { | |
1dc43cf0 JS |
5049 | extern unsigned long __start_mcount_loc[]; |
5050 | extern unsigned long __stop_mcount_loc[]; | |
3a36cb11 | 5051 | unsigned long count, flags; |
68bf21aa SR |
5052 | int ret; |
5053 | ||
68bf21aa | 5054 | local_irq_save(flags); |
3a36cb11 | 5055 | ret = ftrace_dyn_arch_init(); |
68bf21aa | 5056 | local_irq_restore(flags); |
af64a7cb | 5057 | if (ret) |
68bf21aa SR |
5058 | goto failed; |
5059 | ||
5060 | count = __stop_mcount_loc - __start_mcount_loc; | |
c867ccd8 JS |
5061 | if (!count) { |
5062 | pr_info("ftrace: No functions to be traced?\n"); | |
68bf21aa | 5063 | goto failed; |
c867ccd8 JS |
5064 | } |
5065 | ||
5066 | pr_info("ftrace: allocating %ld entries in %ld pages\n", | |
5067 | count, count / ENTRIES_PER_PAGE + 1); | |
68bf21aa SR |
5068 | |
5069 | last_ftrace_enabled = ftrace_enabled = 1; | |
5070 | ||
5cb084bb | 5071 | ret = ftrace_process_locs(NULL, |
31e88909 | 5072 | __start_mcount_loc, |
68bf21aa SR |
5073 | __stop_mcount_loc); |
5074 | ||
2af15d6a SR |
5075 | set_ftrace_early_filters(); |
5076 | ||
68bf21aa SR |
5077 | return; |
5078 | failed: | |
5079 | ftrace_disabled = 1; | |
5080 | } | |
68bf21aa | 5081 | |
f3bea491 SRRH |
5082 | /* Do nothing if arch does not support this */ |
5083 | void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops) | |
5084 | { | |
5085 | } | |
5086 | ||
5087 | static void ftrace_update_trampoline(struct ftrace_ops *ops) | |
5088 | { | |
12cce594 SRRH |
5089 | |
5090 | /* | |
5091 | * Currently there's no safe way to free a trampoline when the kernel | |
5092 | * is configured with PREEMPT. That is because a task could be preempted | |
5093 | * when it jumped to the trampoline, it may be preempted for a long time | |
5094 | * depending on the system load, and currently there's no way to know | |
5095 | * when it will be off the trampoline. If the trampoline is freed | |
5096 | * too early, when the task runs again, it will be executing on freed | |
5097 | * memory and crash. | |
5098 | */ | |
5099 | #ifdef CONFIG_PREEMPT | |
f3bea491 SRRH |
5100 | /* Currently, only non dynamic ops can have a trampoline */ |
5101 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC) | |
5102 | return; | |
12cce594 | 5103 | #endif |
f3bea491 SRRH |
5104 | |
5105 | arch_ftrace_update_trampoline(ops); | |
5106 | } | |
5107 | ||
3d083395 | 5108 | #else |
0b6e4d56 | 5109 | |
2b499381 | 5110 | static struct ftrace_ops global_ops = { |
bd69c30b | 5111 | .func = ftrace_stub, |
e3eea140 SRRH |
5112 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | |
5113 | FTRACE_OPS_FL_INITIALIZED | | |
5114 | FTRACE_OPS_FL_PID, | |
bd69c30b SR |
5115 | }; |
5116 | ||
0b6e4d56 FW |
5117 | static int __init ftrace_nodyn_init(void) |
5118 | { | |
5119 | ftrace_enabled = 1; | |
5120 | return 0; | |
5121 | } | |
6f415672 | 5122 | core_initcall(ftrace_nodyn_init); |
0b6e4d56 | 5123 | |
8434dc93 | 5124 | static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; } |
df4fc315 | 5125 | static inline void ftrace_startup_enable(int command) { } |
e1effa01 | 5126 | static inline void ftrace_startup_all(int command) { } |
5a45cfe1 | 5127 | /* Keep as macros so we do not need to define the commands */ |
8a56d776 SRRH |
5128 | # define ftrace_startup(ops, command) \ |
5129 | ({ \ | |
5130 | int ___ret = __register_ftrace_function(ops); \ | |
5131 | if (!___ret) \ | |
5132 | (ops)->flags |= FTRACE_OPS_FL_ENABLED; \ | |
5133 | ___ret; \ | |
3b6cfdb1 | 5134 | }) |
1fcc1553 SRRH |
5135 | # define ftrace_shutdown(ops, command) \ |
5136 | ({ \ | |
5137 | int ___ret = __unregister_ftrace_function(ops); \ | |
5138 | if (!___ret) \ | |
5139 | (ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \ | |
5140 | ___ret; \ | |
5141 | }) | |
8a56d776 | 5142 | |
c7aafc54 IM |
5143 | # define ftrace_startup_sysctl() do { } while (0) |
5144 | # define ftrace_shutdown_sysctl() do { } while (0) | |
b848914c SR |
5145 | |
5146 | static inline int | |
195a8afc | 5147 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
b848914c SR |
5148 | { |
5149 | return 1; | |
5150 | } | |
5151 | ||
f3bea491 SRRH |
5152 | static void ftrace_update_trampoline(struct ftrace_ops *ops) |
5153 | { | |
5154 | } | |
5155 | ||
3d083395 SR |
5156 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
5157 | ||
4104d326 SRRH |
5158 | __init void ftrace_init_global_array_ops(struct trace_array *tr) |
5159 | { | |
5160 | tr->ops = &global_ops; | |
5161 | tr->ops->private = tr; | |
5162 | } | |
5163 | ||
5164 | void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func) | |
5165 | { | |
5166 | /* If we filter on pids, update to use the pid function */ | |
5167 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL) { | |
5168 | if (WARN_ON(tr->ops->func != ftrace_stub)) | |
5169 | printk("ftrace ops had %pS for function\n", | |
5170 | tr->ops->func); | |
4104d326 SRRH |
5171 | } |
5172 | tr->ops->func = func; | |
5173 | tr->ops->private = tr; | |
5174 | } | |
5175 | ||
5176 | void ftrace_reset_array_ops(struct trace_array *tr) | |
5177 | { | |
5178 | tr->ops->func = ftrace_stub; | |
5179 | } | |
5180 | ||
2f5f6ad9 SR |
5181 | static inline void |
5182 | __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 5183 | struct ftrace_ops *ignored, struct pt_regs *regs) |
b848914c | 5184 | { |
cdbe61bf | 5185 | struct ftrace_ops *op; |
edc15caf | 5186 | int bit; |
b848914c | 5187 | |
edc15caf SR |
5188 | bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX); |
5189 | if (bit < 0) | |
5190 | return; | |
b1cff0ad | 5191 | |
cdbe61bf SR |
5192 | /* |
5193 | * Some of the ops may be dynamically allocated, | |
5194 | * they must be freed after a synchronize_sched(). | |
5195 | */ | |
5196 | preempt_disable_notrace(); | |
ba27f2bc | 5197 | |
0a016409 | 5198 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
ba27f2bc SRRH |
5199 | /* |
5200 | * Check the following for each ops before calling their func: | |
5201 | * if RCU flag is set, then rcu_is_watching() must be true | |
5202 | * if PER_CPU is set, then ftrace_function_local_disable() | |
5203 | * must be false | |
5204 | * Otherwise test if the ip matches the ops filter | |
5205 | * | |
5206 | * If any of the above fails then the op->func() is not executed. | |
5207 | */ | |
5208 | if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) && | |
5209 | (!(op->flags & FTRACE_OPS_FL_PER_CPU) || | |
5210 | !ftrace_function_local_disabled(op)) && | |
5211 | ftrace_ops_test(op, ip, regs)) { | |
5212 | ||
1d48d596 SRRH |
5213 | if (FTRACE_WARN_ON(!op->func)) { |
5214 | pr_warn("op=%p %pS\n", op, op); | |
4104d326 SRRH |
5215 | goto out; |
5216 | } | |
a1e2e31d | 5217 | op->func(ip, parent_ip, op, regs); |
4104d326 | 5218 | } |
0a016409 | 5219 | } while_for_each_ftrace_op(op); |
4104d326 | 5220 | out: |
cdbe61bf | 5221 | preempt_enable_notrace(); |
edc15caf | 5222 | trace_clear_recursion(bit); |
b848914c SR |
5223 | } |
5224 | ||
2f5f6ad9 SR |
5225 | /* |
5226 | * Some archs only support passing ip and parent_ip. Even though | |
5227 | * the list function ignores the op parameter, we do not want any | |
5228 | * C side effects, where a function is called without the caller | |
5229 | * sending a third parameter. | |
a1e2e31d SR |
5230 | * Archs are to support both the regs and ftrace_ops at the same time. |
5231 | * If they support ftrace_ops, it is assumed they support regs. | |
5232 | * If call backs want to use regs, they must either check for regs | |
06aeaaea MH |
5233 | * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS. |
5234 | * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved. | |
a1e2e31d | 5235 | * An architecture can pass partial regs with ftrace_ops and still |
b8ec330a | 5236 | * set the ARCH_SUPPORTS_FTRACE_OPS. |
2f5f6ad9 SR |
5237 | */ |
5238 | #if ARCH_SUPPORTS_FTRACE_OPS | |
5239 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 5240 | struct ftrace_ops *op, struct pt_regs *regs) |
2f5f6ad9 | 5241 | { |
a1e2e31d | 5242 | __ftrace_ops_list_func(ip, parent_ip, NULL, regs); |
2f5f6ad9 SR |
5243 | } |
5244 | #else | |
5245 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip) | |
5246 | { | |
a1e2e31d | 5247 | __ftrace_ops_list_func(ip, parent_ip, NULL, NULL); |
2f5f6ad9 SR |
5248 | } |
5249 | #endif | |
5250 | ||
f1ff6348 SRRH |
5251 | /* |
5252 | * If there's only one function registered but it does not support | |
c68c0fa2 SRRH |
5253 | * recursion, needs RCU protection and/or requires per cpu handling, then |
5254 | * this function will be called by the mcount trampoline. | |
f1ff6348 | 5255 | */ |
c68c0fa2 | 5256 | static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip, |
f1ff6348 SRRH |
5257 | struct ftrace_ops *op, struct pt_regs *regs) |
5258 | { | |
5259 | int bit; | |
5260 | ||
c68c0fa2 SRRH |
5261 | if ((op->flags & FTRACE_OPS_FL_RCU) && !rcu_is_watching()) |
5262 | return; | |
5263 | ||
f1ff6348 SRRH |
5264 | bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX); |
5265 | if (bit < 0) | |
5266 | return; | |
5267 | ||
c68c0fa2 | 5268 | preempt_disable_notrace(); |
f1ff6348 | 5269 | |
c68c0fa2 SRRH |
5270 | if (!(op->flags & FTRACE_OPS_FL_PER_CPU) || |
5271 | !ftrace_function_local_disabled(op)) { | |
5272 | op->func(ip, parent_ip, op, regs); | |
5273 | } | |
5274 | ||
5275 | preempt_enable_notrace(); | |
f1ff6348 SRRH |
5276 | trace_clear_recursion(bit); |
5277 | } | |
5278 | ||
87354059 SRRH |
5279 | /** |
5280 | * ftrace_ops_get_func - get the function a trampoline should call | |
5281 | * @ops: the ops to get the function for | |
5282 | * | |
5283 | * Normally the mcount trampoline will call the ops->func, but there | |
5284 | * are times that it should not. For example, if the ops does not | |
5285 | * have its own recursion protection, then it should call the | |
5286 | * ftrace_ops_recurs_func() instead. | |
5287 | * | |
5288 | * Returns the function that the trampoline should call for @ops. | |
5289 | */ | |
5290 | ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops) | |
5291 | { | |
87354059 | 5292 | /* |
c68c0fa2 SRRH |
5293 | * If the function does not handle recursion, needs to be RCU safe, |
5294 | * or does per cpu logic, then we need to call the assist handler. | |
87354059 | 5295 | */ |
c68c0fa2 SRRH |
5296 | if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE) || |
5297 | ops->flags & (FTRACE_OPS_FL_RCU | FTRACE_OPS_FL_PER_CPU)) | |
5298 | return ftrace_ops_assist_func; | |
87354059 SRRH |
5299 | |
5300 | return ops->func; | |
5301 | } | |
5302 | ||
e32d8956 | 5303 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
5304 | { |
5305 | struct task_struct *p; | |
e32d8956 | 5306 | int cpu; |
978f3a45 | 5307 | |
e32d8956 SR |
5308 | get_online_cpus(); |
5309 | for_each_online_cpu(cpu) { | |
5310 | p = idle_task(cpu); | |
978f3a45 | 5311 | clear_tsk_trace_trace(p); |
e32d8956 SR |
5312 | } |
5313 | put_online_cpus(); | |
5314 | } | |
978f3a45 | 5315 | |
e32d8956 SR |
5316 | static void set_ftrace_swapper(void) |
5317 | { | |
5318 | struct task_struct *p; | |
5319 | int cpu; | |
5320 | ||
5321 | get_online_cpus(); | |
5322 | for_each_online_cpu(cpu) { | |
5323 | p = idle_task(cpu); | |
5324 | set_tsk_trace_trace(p); | |
5325 | } | |
5326 | put_online_cpus(); | |
978f3a45 SR |
5327 | } |
5328 | ||
e32d8956 SR |
5329 | static void clear_ftrace_pid(struct pid *pid) |
5330 | { | |
5331 | struct task_struct *p; | |
5332 | ||
229c4ef8 | 5333 | rcu_read_lock(); |
e32d8956 SR |
5334 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
5335 | clear_tsk_trace_trace(p); | |
5336 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
5337 | rcu_read_unlock(); |
5338 | ||
e32d8956 SR |
5339 | put_pid(pid); |
5340 | } | |
5341 | ||
5342 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
5343 | { |
5344 | struct task_struct *p; | |
5345 | ||
229c4ef8 | 5346 | rcu_read_lock(); |
978f3a45 SR |
5347 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
5348 | set_tsk_trace_trace(p); | |
5349 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 5350 | rcu_read_unlock(); |
978f3a45 SR |
5351 | } |
5352 | ||
756d17ee | 5353 | static void clear_ftrace_pid_task(struct pid *pid) |
e32d8956 | 5354 | { |
756d17ee | 5355 | if (pid == ftrace_swapper_pid) |
e32d8956 SR |
5356 | clear_ftrace_swapper(); |
5357 | else | |
756d17ee | 5358 | clear_ftrace_pid(pid); |
e32d8956 SR |
5359 | } |
5360 | ||
5361 | static void set_ftrace_pid_task(struct pid *pid) | |
5362 | { | |
5363 | if (pid == ftrace_swapper_pid) | |
5364 | set_ftrace_swapper(); | |
5365 | else | |
5366 | set_ftrace_pid(pid); | |
5367 | } | |
5368 | ||
756d17ee | 5369 | static int ftrace_pid_add(int p) |
df4fc315 | 5370 | { |
978f3a45 | 5371 | struct pid *pid; |
756d17ee | 5372 | struct ftrace_pid *fpid; |
5373 | int ret = -EINVAL; | |
df4fc315 | 5374 | |
756d17ee | 5375 | mutex_lock(&ftrace_lock); |
df4fc315 | 5376 | |
756d17ee | 5377 | if (!p) |
5378 | pid = ftrace_swapper_pid; | |
5379 | else | |
5380 | pid = find_get_pid(p); | |
df4fc315 | 5381 | |
756d17ee | 5382 | if (!pid) |
5383 | goto out; | |
df4fc315 | 5384 | |
756d17ee | 5385 | ret = 0; |
df4fc315 | 5386 | |
756d17ee | 5387 | list_for_each_entry(fpid, &ftrace_pids, list) |
5388 | if (fpid->pid == pid) | |
5389 | goto out_put; | |
978f3a45 | 5390 | |
756d17ee | 5391 | ret = -ENOMEM; |
df4fc315 | 5392 | |
756d17ee | 5393 | fpid = kmalloc(sizeof(*fpid), GFP_KERNEL); |
5394 | if (!fpid) | |
5395 | goto out_put; | |
df4fc315 | 5396 | |
756d17ee | 5397 | list_add(&fpid->list, &ftrace_pids); |
5398 | fpid->pid = pid; | |
0ef8cde5 | 5399 | |
756d17ee | 5400 | set_ftrace_pid_task(pid); |
978f3a45 | 5401 | |
756d17ee | 5402 | ftrace_update_pid_func(); |
e1effa01 SRRH |
5403 | |
5404 | ftrace_startup_all(0); | |
756d17ee | 5405 | |
5406 | mutex_unlock(&ftrace_lock); | |
5407 | return 0; | |
5408 | ||
5409 | out_put: | |
5410 | if (pid != ftrace_swapper_pid) | |
5411 | put_pid(pid); | |
978f3a45 | 5412 | |
756d17ee | 5413 | out: |
5414 | mutex_unlock(&ftrace_lock); | |
5415 | return ret; | |
5416 | } | |
5417 | ||
5418 | static void ftrace_pid_reset(void) | |
5419 | { | |
5420 | struct ftrace_pid *fpid, *safe; | |
978f3a45 | 5421 | |
756d17ee | 5422 | mutex_lock(&ftrace_lock); |
5423 | list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) { | |
5424 | struct pid *pid = fpid->pid; | |
5425 | ||
5426 | clear_ftrace_pid_task(pid); | |
5427 | ||
5428 | list_del(&fpid->list); | |
5429 | kfree(fpid); | |
df4fc315 SR |
5430 | } |
5431 | ||
df4fc315 | 5432 | ftrace_update_pid_func(); |
e1effa01 | 5433 | ftrace_startup_all(0); |
df4fc315 | 5434 | |
e6ea44e9 | 5435 | mutex_unlock(&ftrace_lock); |
756d17ee | 5436 | } |
df4fc315 | 5437 | |
756d17ee | 5438 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
5439 | { | |
5440 | mutex_lock(&ftrace_lock); | |
5441 | ||
e3eea140 | 5442 | if (!ftrace_pids_enabled() && (!*pos)) |
756d17ee | 5443 | return (void *) 1; |
5444 | ||
5445 | return seq_list_start(&ftrace_pids, *pos); | |
5446 | } | |
5447 | ||
5448 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
5449 | { | |
5450 | if (v == (void *)1) | |
5451 | return NULL; | |
5452 | ||
5453 | return seq_list_next(v, &ftrace_pids, pos); | |
5454 | } | |
5455 | ||
5456 | static void fpid_stop(struct seq_file *m, void *p) | |
5457 | { | |
5458 | mutex_unlock(&ftrace_lock); | |
5459 | } | |
5460 | ||
5461 | static int fpid_show(struct seq_file *m, void *v) | |
5462 | { | |
5463 | const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list); | |
5464 | ||
5465 | if (v == (void *)1) { | |
fa6f0cc7 | 5466 | seq_puts(m, "no pid\n"); |
756d17ee | 5467 | return 0; |
5468 | } | |
5469 | ||
5470 | if (fpid->pid == ftrace_swapper_pid) | |
fa6f0cc7 | 5471 | seq_puts(m, "swapper tasks\n"); |
756d17ee | 5472 | else |
5473 | seq_printf(m, "%u\n", pid_vnr(fpid->pid)); | |
5474 | ||
5475 | return 0; | |
5476 | } | |
5477 | ||
5478 | static const struct seq_operations ftrace_pid_sops = { | |
5479 | .start = fpid_start, | |
5480 | .next = fpid_next, | |
5481 | .stop = fpid_stop, | |
5482 | .show = fpid_show, | |
5483 | }; | |
5484 | ||
5485 | static int | |
5486 | ftrace_pid_open(struct inode *inode, struct file *file) | |
5487 | { | |
5488 | int ret = 0; | |
5489 | ||
5490 | if ((file->f_mode & FMODE_WRITE) && | |
5491 | (file->f_flags & O_TRUNC)) | |
5492 | ftrace_pid_reset(); | |
5493 | ||
5494 | if (file->f_mode & FMODE_READ) | |
5495 | ret = seq_open(file, &ftrace_pid_sops); | |
5496 | ||
5497 | return ret; | |
5498 | } | |
5499 | ||
df4fc315 SR |
5500 | static ssize_t |
5501 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
5502 | size_t cnt, loff_t *ppos) | |
5503 | { | |
457dc928 | 5504 | char buf[64], *tmp; |
df4fc315 SR |
5505 | long val; |
5506 | int ret; | |
5507 | ||
5508 | if (cnt >= sizeof(buf)) | |
5509 | return -EINVAL; | |
5510 | ||
5511 | if (copy_from_user(&buf, ubuf, cnt)) | |
5512 | return -EFAULT; | |
5513 | ||
5514 | buf[cnt] = 0; | |
5515 | ||
756d17ee | 5516 | /* |
5517 | * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid" | |
5518 | * to clean the filter quietly. | |
5519 | */ | |
457dc928 IM |
5520 | tmp = strstrip(buf); |
5521 | if (strlen(tmp) == 0) | |
756d17ee | 5522 | return 1; |
5523 | ||
bcd83ea6 | 5524 | ret = kstrtol(tmp, 10, &val); |
df4fc315 SR |
5525 | if (ret < 0) |
5526 | return ret; | |
5527 | ||
756d17ee | 5528 | ret = ftrace_pid_add(val); |
df4fc315 | 5529 | |
756d17ee | 5530 | return ret ? ret : cnt; |
5531 | } | |
df4fc315 | 5532 | |
756d17ee | 5533 | static int |
5534 | ftrace_pid_release(struct inode *inode, struct file *file) | |
5535 | { | |
5536 | if (file->f_mode & FMODE_READ) | |
5537 | seq_release(inode, file); | |
df4fc315 | 5538 | |
756d17ee | 5539 | return 0; |
df4fc315 SR |
5540 | } |
5541 | ||
5e2336a0 | 5542 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 5543 | .open = ftrace_pid_open, |
5544 | .write = ftrace_pid_write, | |
5545 | .read = seq_read, | |
098c879e | 5546 | .llseek = tracing_lseek, |
756d17ee | 5547 | .release = ftrace_pid_release, |
df4fc315 SR |
5548 | }; |
5549 | ||
8434dc93 | 5550 | static __init int ftrace_init_tracefs(void) |
df4fc315 SR |
5551 | { |
5552 | struct dentry *d_tracer; | |
df4fc315 SR |
5553 | |
5554 | d_tracer = tracing_init_dentry(); | |
14a5ae40 | 5555 | if (IS_ERR(d_tracer)) |
df4fc315 SR |
5556 | return 0; |
5557 | ||
8434dc93 | 5558 | ftrace_init_dyn_tracefs(d_tracer); |
df4fc315 | 5559 | |
5452af66 FW |
5560 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
5561 | NULL, &ftrace_pid_fops); | |
493762fc | 5562 | |
8434dc93 | 5563 | ftrace_profile_tracefs(d_tracer); |
493762fc | 5564 | |
df4fc315 SR |
5565 | return 0; |
5566 | } | |
8434dc93 | 5567 | fs_initcall(ftrace_init_tracefs); |
df4fc315 | 5568 | |
a2bb6a3d | 5569 | /** |
81adbdc0 | 5570 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
5571 | * |
5572 | * This function should be used by panic code. It stops ftrace | |
5573 | * but in a not so nice way. If you need to simply kill ftrace | |
5574 | * from a non-atomic section, use ftrace_kill. | |
5575 | */ | |
81adbdc0 | 5576 | void ftrace_kill(void) |
a2bb6a3d SR |
5577 | { |
5578 | ftrace_disabled = 1; | |
5579 | ftrace_enabled = 0; | |
a2bb6a3d SR |
5580 | clear_ftrace_function(); |
5581 | } | |
5582 | ||
e0a413f6 SR |
5583 | /** |
5584 | * Test if ftrace is dead or not. | |
5585 | */ | |
5586 | int ftrace_is_dead(void) | |
5587 | { | |
5588 | return ftrace_disabled; | |
5589 | } | |
5590 | ||
16444a8a | 5591 | /** |
3d083395 SR |
5592 | * register_ftrace_function - register a function for profiling |
5593 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 5594 | * |
3d083395 SR |
5595 | * Register a function to be called by all functions in the |
5596 | * kernel. | |
5597 | * | |
5598 | * Note: @ops->func and all the functions it calls must be labeled | |
5599 | * with "notrace", otherwise it will go into a | |
5600 | * recursive loop. | |
16444a8a | 5601 | */ |
3d083395 | 5602 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 5603 | { |
45a4a237 | 5604 | int ret = -1; |
4eebcc81 | 5605 | |
f04f24fb MH |
5606 | ftrace_ops_init(ops); |
5607 | ||
e6ea44e9 | 5608 | mutex_lock(&ftrace_lock); |
e7d3737e | 5609 | |
8a56d776 | 5610 | ret = ftrace_startup(ops, 0); |
b848914c | 5611 | |
e6ea44e9 | 5612 | mutex_unlock(&ftrace_lock); |
8d240dd8 | 5613 | |
b0fc494f | 5614 | return ret; |
3d083395 | 5615 | } |
cdbe61bf | 5616 | EXPORT_SYMBOL_GPL(register_ftrace_function); |
3d083395 SR |
5617 | |
5618 | /** | |
32632920 | 5619 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
5620 | * @ops - ops structure that holds the function to unregister |
5621 | * | |
5622 | * Unregister a function that was added to be called by ftrace profiling. | |
5623 | */ | |
5624 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
5625 | { | |
5626 | int ret; | |
5627 | ||
e6ea44e9 | 5628 | mutex_lock(&ftrace_lock); |
8a56d776 | 5629 | ret = ftrace_shutdown(ops, 0); |
e6ea44e9 | 5630 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
5631 | |
5632 | return ret; | |
5633 | } | |
cdbe61bf | 5634 | EXPORT_SYMBOL_GPL(unregister_ftrace_function); |
b0fc494f | 5635 | |
e309b41d | 5636 | int |
b0fc494f | 5637 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
8d65af78 | 5638 | void __user *buffer, size_t *lenp, |
b0fc494f SR |
5639 | loff_t *ppos) |
5640 | { | |
45a4a237 | 5641 | int ret = -ENODEV; |
4eebcc81 | 5642 | |
e6ea44e9 | 5643 | mutex_lock(&ftrace_lock); |
b0fc494f | 5644 | |
45a4a237 SR |
5645 | if (unlikely(ftrace_disabled)) |
5646 | goto out; | |
5647 | ||
5648 | ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
b0fc494f | 5649 | |
a32c7765 | 5650 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
5651 | goto out; |
5652 | ||
a32c7765 | 5653 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f SR |
5654 | |
5655 | if (ftrace_enabled) { | |
5656 | ||
b0fc494f | 5657 | /* we are starting ftrace again */ |
5000c418 JK |
5658 | if (ftrace_ops_list != &ftrace_list_end) |
5659 | update_ftrace_function(); | |
b0fc494f | 5660 | |
524a3868 SRRH |
5661 | ftrace_startup_sysctl(); |
5662 | ||
b0fc494f SR |
5663 | } else { |
5664 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
5665 | ftrace_trace_function = ftrace_stub; | |
5666 | ||
5667 | ftrace_shutdown_sysctl(); | |
5668 | } | |
5669 | ||
5670 | out: | |
e6ea44e9 | 5671 | mutex_unlock(&ftrace_lock); |
3d083395 | 5672 | return ret; |
16444a8a | 5673 | } |
f17845e5 | 5674 | |
fb52607a | 5675 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 5676 | |
5f151b24 SRRH |
5677 | static struct ftrace_ops graph_ops = { |
5678 | .func = ftrace_stub, | |
5679 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | | |
5680 | FTRACE_OPS_FL_INITIALIZED | | |
e3eea140 | 5681 | FTRACE_OPS_FL_PID | |
5f151b24 SRRH |
5682 | FTRACE_OPS_FL_STUB, |
5683 | #ifdef FTRACE_GRAPH_TRAMP_ADDR | |
5684 | .trampoline = FTRACE_GRAPH_TRAMP_ADDR, | |
aec0be2d | 5685 | /* trampoline_size is only needed for dynamically allocated tramps */ |
5f151b24 SRRH |
5686 | #endif |
5687 | ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash) | |
5688 | }; | |
5689 | ||
55577204 SRRH |
5690 | void ftrace_graph_sleep_time_control(bool enable) |
5691 | { | |
5692 | fgraph_sleep_time = enable; | |
5693 | } | |
5694 | ||
5695 | void ftrace_graph_graph_time_control(bool enable) | |
5696 | { | |
5697 | fgraph_graph_time = enable; | |
5698 | } | |
5699 | ||
e49dc19c SR |
5700 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
5701 | { | |
5702 | return 0; | |
5703 | } | |
5704 | ||
287b6e68 FW |
5705 | /* The callbacks that hook a function */ |
5706 | trace_func_graph_ret_t ftrace_graph_return = | |
5707 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 5708 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
23a8e844 | 5709 | static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
5710 | |
5711 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
5712 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
5713 | { | |
5714 | int i; | |
5715 | int ret = 0; | |
5716 | unsigned long flags; | |
5717 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
5718 | struct task_struct *g, *t; | |
5719 | ||
5720 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
5721 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
5722 | * sizeof(struct ftrace_ret_stack), | |
5723 | GFP_KERNEL); | |
5724 | if (!ret_stack_list[i]) { | |
5725 | start = 0; | |
5726 | end = i; | |
5727 | ret = -ENOMEM; | |
5728 | goto free; | |
5729 | } | |
5730 | } | |
5731 | ||
5732 | read_lock_irqsave(&tasklist_lock, flags); | |
5733 | do_each_thread(g, t) { | |
5734 | if (start == end) { | |
5735 | ret = -EAGAIN; | |
5736 | goto unlock; | |
5737 | } | |
5738 | ||
5739 | if (t->ret_stack == NULL) { | |
380c4b14 | 5740 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 5741 | atomic_set(&t->trace_overrun, 0); |
26c01624 SR |
5742 | t->curr_ret_stack = -1; |
5743 | /* Make sure the tasks see the -1 first: */ | |
5744 | smp_wmb(); | |
5745 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
5746 | } |
5747 | } while_each_thread(g, t); | |
5748 | ||
5749 | unlock: | |
5750 | read_unlock_irqrestore(&tasklist_lock, flags); | |
5751 | free: | |
5752 | for (i = start; i < end; i++) | |
5753 | kfree(ret_stack_list[i]); | |
5754 | return ret; | |
5755 | } | |
5756 | ||
8aef2d28 | 5757 | static void |
c73464b1 | 5758 | ftrace_graph_probe_sched_switch(void *ignore, bool preempt, |
38516ab5 | 5759 | struct task_struct *prev, struct task_struct *next) |
8aef2d28 SR |
5760 | { |
5761 | unsigned long long timestamp; | |
5762 | int index; | |
5763 | ||
be6f164a SR |
5764 | /* |
5765 | * Does the user want to count the time a function was asleep. | |
5766 | * If so, do not update the time stamps. | |
5767 | */ | |
55577204 | 5768 | if (fgraph_sleep_time) |
be6f164a SR |
5769 | return; |
5770 | ||
8aef2d28 SR |
5771 | timestamp = trace_clock_local(); |
5772 | ||
5773 | prev->ftrace_timestamp = timestamp; | |
5774 | ||
5775 | /* only process tasks that we timestamped */ | |
5776 | if (!next->ftrace_timestamp) | |
5777 | return; | |
5778 | ||
5779 | /* | |
5780 | * Update all the counters in next to make up for the | |
5781 | * time next was sleeping. | |
5782 | */ | |
5783 | timestamp -= next->ftrace_timestamp; | |
5784 | ||
5785 | for (index = next->curr_ret_stack; index >= 0; index--) | |
5786 | next->ret_stack[index].calltime += timestamp; | |
5787 | } | |
5788 | ||
f201ae23 | 5789 | /* Allocate a return stack for each task */ |
fb52607a | 5790 | static int start_graph_tracing(void) |
f201ae23 FW |
5791 | { |
5792 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 5793 | int ret, cpu; |
f201ae23 FW |
5794 | |
5795 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
5796 | sizeof(struct ftrace_ret_stack *), | |
5797 | GFP_KERNEL); | |
5798 | ||
5799 | if (!ret_stack_list) | |
5800 | return -ENOMEM; | |
5801 | ||
5b058bcd | 5802 | /* The cpu_boot init_task->ret_stack will never be freed */ |
179c498a SR |
5803 | for_each_online_cpu(cpu) { |
5804 | if (!idle_task(cpu)->ret_stack) | |
868baf07 | 5805 | ftrace_graph_init_idle_task(idle_task(cpu), cpu); |
179c498a | 5806 | } |
5b058bcd | 5807 | |
f201ae23 FW |
5808 | do { |
5809 | ret = alloc_retstack_tasklist(ret_stack_list); | |
5810 | } while (ret == -EAGAIN); | |
5811 | ||
8aef2d28 | 5812 | if (!ret) { |
38516ab5 | 5813 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
8aef2d28 SR |
5814 | if (ret) |
5815 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
5816 | " probe to kernel_sched_switch\n"); | |
5817 | } | |
5818 | ||
f201ae23 FW |
5819 | kfree(ret_stack_list); |
5820 | return ret; | |
5821 | } | |
5822 | ||
4a2b8dda FW |
5823 | /* |
5824 | * Hibernation protection. | |
5825 | * The state of the current task is too much unstable during | |
5826 | * suspend/restore to disk. We want to protect against that. | |
5827 | */ | |
5828 | static int | |
5829 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
5830 | void *unused) | |
5831 | { | |
5832 | switch (state) { | |
5833 | case PM_HIBERNATION_PREPARE: | |
5834 | pause_graph_tracing(); | |
5835 | break; | |
5836 | ||
5837 | case PM_POST_HIBERNATION: | |
5838 | unpause_graph_tracing(); | |
5839 | break; | |
5840 | } | |
5841 | return NOTIFY_DONE; | |
5842 | } | |
5843 | ||
23a8e844 SRRH |
5844 | static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace) |
5845 | { | |
5846 | if (!ftrace_ops_test(&global_ops, trace->func, NULL)) | |
5847 | return 0; | |
5848 | return __ftrace_graph_entry(trace); | |
5849 | } | |
5850 | ||
5851 | /* | |
5852 | * The function graph tracer should only trace the functions defined | |
5853 | * by set_ftrace_filter and set_ftrace_notrace. If another function | |
5854 | * tracer ops is registered, the graph tracer requires testing the | |
5855 | * function against the global ops, and not just trace any function | |
5856 | * that any ftrace_ops registered. | |
5857 | */ | |
5858 | static void update_function_graph_func(void) | |
5859 | { | |
5f151b24 SRRH |
5860 | struct ftrace_ops *op; |
5861 | bool do_test = false; | |
5862 | ||
5863 | /* | |
5864 | * The graph and global ops share the same set of functions | |
5865 | * to test. If any other ops is on the list, then | |
5866 | * the graph tracing needs to test if its the function | |
5867 | * it should call. | |
5868 | */ | |
5869 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
5870 | if (op != &global_ops && op != &graph_ops && | |
5871 | op != &ftrace_list_end) { | |
5872 | do_test = true; | |
5873 | /* in double loop, break out with goto */ | |
5874 | goto out; | |
5875 | } | |
5876 | } while_for_each_ftrace_op(op); | |
5877 | out: | |
5878 | if (do_test) | |
23a8e844 | 5879 | ftrace_graph_entry = ftrace_graph_entry_test; |
5f151b24 SRRH |
5880 | else |
5881 | ftrace_graph_entry = __ftrace_graph_entry; | |
23a8e844 SRRH |
5882 | } |
5883 | ||
8275f69f MK |
5884 | static struct notifier_block ftrace_suspend_notifier = { |
5885 | .notifier_call = ftrace_suspend_notifier_call, | |
5886 | }; | |
5887 | ||
287b6e68 FW |
5888 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
5889 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 5890 | { |
e7d3737e FW |
5891 | int ret = 0; |
5892 | ||
e6ea44e9 | 5893 | mutex_lock(&ftrace_lock); |
e7d3737e | 5894 | |
05ce5818 | 5895 | /* we currently allow only one tracer registered at a time */ |
597af815 | 5896 | if (ftrace_graph_active) { |
05ce5818 SR |
5897 | ret = -EBUSY; |
5898 | goto out; | |
5899 | } | |
5900 | ||
4a2b8dda FW |
5901 | register_pm_notifier(&ftrace_suspend_notifier); |
5902 | ||
597af815 | 5903 | ftrace_graph_active++; |
fb52607a | 5904 | ret = start_graph_tracing(); |
f201ae23 | 5905 | if (ret) { |
597af815 | 5906 | ftrace_graph_active--; |
f201ae23 FW |
5907 | goto out; |
5908 | } | |
e53a6319 | 5909 | |
287b6e68 | 5910 | ftrace_graph_return = retfunc; |
23a8e844 SRRH |
5911 | |
5912 | /* | |
5913 | * Update the indirect function to the entryfunc, and the | |
5914 | * function that gets called to the entry_test first. Then | |
5915 | * call the update fgraph entry function to determine if | |
5916 | * the entryfunc should be called directly or not. | |
5917 | */ | |
5918 | __ftrace_graph_entry = entryfunc; | |
5919 | ftrace_graph_entry = ftrace_graph_entry_test; | |
5920 | update_function_graph_func(); | |
e53a6319 | 5921 | |
5f151b24 | 5922 | ret = ftrace_startup(&graph_ops, FTRACE_START_FUNC_RET); |
e7d3737e | 5923 | out: |
e6ea44e9 | 5924 | mutex_unlock(&ftrace_lock); |
e7d3737e | 5925 | return ret; |
15e6cb36 FW |
5926 | } |
5927 | ||
fb52607a | 5928 | void unregister_ftrace_graph(void) |
15e6cb36 | 5929 | { |
e6ea44e9 | 5930 | mutex_lock(&ftrace_lock); |
e7d3737e | 5931 | |
597af815 | 5932 | if (unlikely(!ftrace_graph_active)) |
2aad1b76 SR |
5933 | goto out; |
5934 | ||
597af815 | 5935 | ftrace_graph_active--; |
287b6e68 | 5936 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 5937 | ftrace_graph_entry = ftrace_graph_entry_stub; |
23a8e844 | 5938 | __ftrace_graph_entry = ftrace_graph_entry_stub; |
5f151b24 | 5939 | ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET); |
4a2b8dda | 5940 | unregister_pm_notifier(&ftrace_suspend_notifier); |
38516ab5 | 5941 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
e7d3737e | 5942 | |
f3bea491 SRRH |
5943 | #ifdef CONFIG_DYNAMIC_FTRACE |
5944 | /* | |
5945 | * Function graph does not allocate the trampoline, but | |
5946 | * other global_ops do. We need to reset the ALLOC_TRAMP flag | |
5947 | * if one was used. | |
5948 | */ | |
5949 | global_ops.trampoline = save_global_trampoline; | |
5950 | if (save_global_flags & FTRACE_OPS_FL_ALLOC_TRAMP) | |
5951 | global_ops.flags |= FTRACE_OPS_FL_ALLOC_TRAMP; | |
5952 | #endif | |
5953 | ||
2aad1b76 | 5954 | out: |
e6ea44e9 | 5955 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 5956 | } |
f201ae23 | 5957 | |
868baf07 SR |
5958 | static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack); |
5959 | ||
5960 | static void | |
5961 | graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack) | |
5962 | { | |
5963 | atomic_set(&t->tracing_graph_pause, 0); | |
5964 | atomic_set(&t->trace_overrun, 0); | |
5965 | t->ftrace_timestamp = 0; | |
25985edc | 5966 | /* make curr_ret_stack visible before we add the ret_stack */ |
868baf07 SR |
5967 | smp_wmb(); |
5968 | t->ret_stack = ret_stack; | |
5969 | } | |
5970 | ||
5971 | /* | |
5972 | * Allocate a return stack for the idle task. May be the first | |
5973 | * time through, or it may be done by CPU hotplug online. | |
5974 | */ | |
5975 | void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) | |
5976 | { | |
5977 | t->curr_ret_stack = -1; | |
5978 | /* | |
5979 | * The idle task has no parent, it either has its own | |
5980 | * stack or no stack at all. | |
5981 | */ | |
5982 | if (t->ret_stack) | |
5983 | WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu)); | |
5984 | ||
5985 | if (ftrace_graph_active) { | |
5986 | struct ftrace_ret_stack *ret_stack; | |
5987 | ||
5988 | ret_stack = per_cpu(idle_ret_stack, cpu); | |
5989 | if (!ret_stack) { | |
5990 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
5991 | * sizeof(struct ftrace_ret_stack), | |
5992 | GFP_KERNEL); | |
5993 | if (!ret_stack) | |
5994 | return; | |
5995 | per_cpu(idle_ret_stack, cpu) = ret_stack; | |
5996 | } | |
5997 | graph_init_task(t, ret_stack); | |
5998 | } | |
5999 | } | |
6000 | ||
f201ae23 | 6001 | /* Allocate a return stack for newly created task */ |
fb52607a | 6002 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 6003 | { |
84047e36 SR |
6004 | /* Make sure we do not use the parent ret_stack */ |
6005 | t->ret_stack = NULL; | |
ea14eb71 | 6006 | t->curr_ret_stack = -1; |
84047e36 | 6007 | |
597af815 | 6008 | if (ftrace_graph_active) { |
82310a32 SR |
6009 | struct ftrace_ret_stack *ret_stack; |
6010 | ||
6011 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
f201ae23 FW |
6012 | * sizeof(struct ftrace_ret_stack), |
6013 | GFP_KERNEL); | |
82310a32 | 6014 | if (!ret_stack) |
f201ae23 | 6015 | return; |
868baf07 | 6016 | graph_init_task(t, ret_stack); |
84047e36 | 6017 | } |
f201ae23 FW |
6018 | } |
6019 | ||
fb52607a | 6020 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 6021 | { |
eae849ca FW |
6022 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
6023 | ||
f201ae23 | 6024 | t->ret_stack = NULL; |
eae849ca FW |
6025 | /* NULL must become visible to IRQs before we free it: */ |
6026 | barrier(); | |
6027 | ||
6028 | kfree(ret_stack); | |
f201ae23 | 6029 | } |
15e6cb36 | 6030 | #endif |