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Commit | Line | Data |
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16444a8a ACM |
1 | /* |
2 | * Infrastructure for profiling code inserted by 'gcc -pg'. | |
3 | * | |
4 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> | |
5 | * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com> | |
6 | * | |
7 | * Originally ported from the -rt patch by: | |
8 | * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com> | |
9 | * | |
10 | * Based on code in the latency_tracer, that is: | |
11 | * | |
12 | * Copyright (C) 2004-2006 Ingo Molnar | |
6d49e352 | 13 | * Copyright (C) 2004 Nadia Yvette Chambers |
16444a8a ACM |
14 | */ |
15 | ||
3d083395 SR |
16 | #include <linux/stop_machine.h> |
17 | #include <linux/clocksource.h> | |
18 | #include <linux/kallsyms.h> | |
5072c59f | 19 | #include <linux/seq_file.h> |
4a2b8dda | 20 | #include <linux/suspend.h> |
5072c59f | 21 | #include <linux/debugfs.h> |
3d083395 | 22 | #include <linux/hardirq.h> |
2d8b820b | 23 | #include <linux/kthread.h> |
5072c59f | 24 | #include <linux/uaccess.h> |
5855fead | 25 | #include <linux/bsearch.h> |
56d82e00 | 26 | #include <linux/module.h> |
2d8b820b | 27 | #include <linux/ftrace.h> |
b0fc494f | 28 | #include <linux/sysctl.h> |
5a0e3ad6 | 29 | #include <linux/slab.h> |
5072c59f | 30 | #include <linux/ctype.h> |
68950619 | 31 | #include <linux/sort.h> |
3d083395 | 32 | #include <linux/list.h> |
59df055f | 33 | #include <linux/hash.h> |
3f379b03 | 34 | #include <linux/rcupdate.h> |
3d083395 | 35 | |
ad8d75ff | 36 | #include <trace/events/sched.h> |
8aef2d28 | 37 | |
2af15d6a | 38 | #include <asm/setup.h> |
395a59d0 | 39 | |
0706f1c4 | 40 | #include "trace_output.h" |
bac429f0 | 41 | #include "trace_stat.h" |
16444a8a | 42 | |
6912896e | 43 | #define FTRACE_WARN_ON(cond) \ |
0778d9ad SR |
44 | ({ \ |
45 | int ___r = cond; \ | |
46 | if (WARN_ON(___r)) \ | |
6912896e | 47 | ftrace_kill(); \ |
0778d9ad SR |
48 | ___r; \ |
49 | }) | |
6912896e SR |
50 | |
51 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
0778d9ad SR |
52 | ({ \ |
53 | int ___r = cond; \ | |
54 | if (WARN_ON_ONCE(___r)) \ | |
6912896e | 55 | ftrace_kill(); \ |
0778d9ad SR |
56 | ___r; \ |
57 | }) | |
6912896e | 58 | |
8fc0c701 SR |
59 | /* hash bits for specific function selection */ |
60 | #define FTRACE_HASH_BITS 7 | |
61 | #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS) | |
33dc9b12 SR |
62 | #define FTRACE_HASH_DEFAULT_BITS 10 |
63 | #define FTRACE_HASH_MAX_BITS 12 | |
8fc0c701 | 64 | |
4104d326 | 65 | #define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_CONTROL) |
e248491a | 66 | |
f04f24fb | 67 | #ifdef CONFIG_DYNAMIC_FTRACE |
33b7f99c SRRH |
68 | #define INIT_OPS_HASH(opsname) \ |
69 | .func_hash = &opsname.local_hash, \ | |
70 | .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock), | |
5f151b24 SRRH |
71 | #define ASSIGN_OPS_HASH(opsname, val) \ |
72 | .func_hash = val, \ | |
73 | .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock), | |
f04f24fb | 74 | #else |
33b7f99c | 75 | #define INIT_OPS_HASH(opsname) |
5f151b24 | 76 | #define ASSIGN_OPS_HASH(opsname, val) |
f04f24fb MH |
77 | #endif |
78 | ||
2f5f6ad9 SR |
79 | static struct ftrace_ops ftrace_list_end __read_mostly = { |
80 | .func = ftrace_stub, | |
395b97a3 | 81 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB, |
33b7f99c | 82 | INIT_OPS_HASH(ftrace_list_end) |
2f5f6ad9 SR |
83 | }; |
84 | ||
4eebcc81 SR |
85 | /* ftrace_enabled is a method to turn ftrace on or off */ |
86 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 87 | static int last_ftrace_enabled; |
b0fc494f | 88 | |
2f5f6ad9 SR |
89 | /* Current function tracing op */ |
90 | struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end; | |
405e1d83 SRRH |
91 | /* What to set function_trace_op to */ |
92 | static struct ftrace_ops *set_function_trace_op; | |
60a7ecf4 | 93 | |
756d17ee | 94 | /* List for set_ftrace_pid's pids. */ |
95 | LIST_HEAD(ftrace_pids); | |
96 | struct ftrace_pid { | |
97 | struct list_head list; | |
98 | struct pid *pid; | |
99 | }; | |
100 | ||
4eebcc81 SR |
101 | /* |
102 | * ftrace_disabled is set when an anomaly is discovered. | |
103 | * ftrace_disabled is much stronger than ftrace_enabled. | |
104 | */ | |
105 | static int ftrace_disabled __read_mostly; | |
106 | ||
52baf119 | 107 | static DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 108 | |
e248491a | 109 | static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end; |
b848914c | 110 | static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end; |
16444a8a | 111 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
df4fc315 | 112 | ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; |
2b499381 | 113 | static struct ftrace_ops global_ops; |
e248491a | 114 | static struct ftrace_ops control_ops; |
16444a8a | 115 | |
f1ff6348 SRRH |
116 | static void ftrace_ops_recurs_func(unsigned long ip, unsigned long parent_ip, |
117 | struct ftrace_ops *op, struct pt_regs *regs); | |
118 | ||
2f5f6ad9 SR |
119 | #if ARCH_SUPPORTS_FTRACE_OPS |
120 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 121 | struct ftrace_ops *op, struct pt_regs *regs); |
2f5f6ad9 SR |
122 | #else |
123 | /* See comment below, where ftrace_ops_list_func is defined */ | |
124 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip); | |
125 | #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops) | |
126 | #endif | |
b848914c | 127 | |
0a016409 SR |
128 | /* |
129 | * Traverse the ftrace_global_list, invoking all entries. The reason that we | |
1bb539ca | 130 | * can use rcu_dereference_raw_notrace() is that elements removed from this list |
0a016409 | 131 | * are simply leaked, so there is no need to interact with a grace-period |
1bb539ca | 132 | * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle |
0a016409 SR |
133 | * concurrent insertions into the ftrace_global_list. |
134 | * | |
135 | * Silly Alpha and silly pointer-speculation compiler optimizations! | |
136 | */ | |
137 | #define do_for_each_ftrace_op(op, list) \ | |
1bb539ca | 138 | op = rcu_dereference_raw_notrace(list); \ |
0a016409 SR |
139 | do |
140 | ||
141 | /* | |
142 | * Optimized for just a single item in the list (as that is the normal case). | |
143 | */ | |
144 | #define while_for_each_ftrace_op(op) \ | |
1bb539ca | 145 | while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \ |
0a016409 SR |
146 | unlikely((op) != &ftrace_list_end)) |
147 | ||
f04f24fb MH |
148 | static inline void ftrace_ops_init(struct ftrace_ops *ops) |
149 | { | |
150 | #ifdef CONFIG_DYNAMIC_FTRACE | |
151 | if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) { | |
33b7f99c SRRH |
152 | mutex_init(&ops->local_hash.regex_lock); |
153 | ops->func_hash = &ops->local_hash; | |
f04f24fb MH |
154 | ops->flags |= FTRACE_OPS_FL_INITIALIZED; |
155 | } | |
156 | #endif | |
157 | } | |
158 | ||
ea701f11 SR |
159 | /** |
160 | * ftrace_nr_registered_ops - return number of ops registered | |
161 | * | |
162 | * Returns the number of ftrace_ops registered and tracing functions | |
163 | */ | |
164 | int ftrace_nr_registered_ops(void) | |
165 | { | |
166 | struct ftrace_ops *ops; | |
167 | int cnt = 0; | |
168 | ||
169 | mutex_lock(&ftrace_lock); | |
170 | ||
171 | for (ops = ftrace_ops_list; | |
172 | ops != &ftrace_list_end; ops = ops->next) | |
173 | cnt++; | |
174 | ||
175 | mutex_unlock(&ftrace_lock); | |
176 | ||
177 | return cnt; | |
178 | } | |
179 | ||
2f5f6ad9 | 180 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 181 | struct ftrace_ops *op, struct pt_regs *regs) |
df4fc315 | 182 | { |
0ef8cde5 | 183 | if (!test_tsk_trace_trace(current)) |
df4fc315 SR |
184 | return; |
185 | ||
a1e2e31d | 186 | ftrace_pid_function(ip, parent_ip, op, regs); |
df4fc315 SR |
187 | } |
188 | ||
189 | static void set_ftrace_pid_function(ftrace_func_t func) | |
190 | { | |
191 | /* do not set ftrace_pid_function to itself! */ | |
192 | if (func != ftrace_pid_func) | |
193 | ftrace_pid_function = func; | |
194 | } | |
195 | ||
16444a8a | 196 | /** |
3d083395 | 197 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 198 | * |
3d083395 SR |
199 | * This NULLs the ftrace function and in essence stops |
200 | * tracing. There may be lag | |
16444a8a | 201 | */ |
3d083395 | 202 | void clear_ftrace_function(void) |
16444a8a | 203 | { |
3d083395 | 204 | ftrace_trace_function = ftrace_stub; |
df4fc315 | 205 | ftrace_pid_function = ftrace_stub; |
3d083395 SR |
206 | } |
207 | ||
e248491a JO |
208 | static void control_ops_disable_all(struct ftrace_ops *ops) |
209 | { | |
210 | int cpu; | |
211 | ||
212 | for_each_possible_cpu(cpu) | |
213 | *per_cpu_ptr(ops->disabled, cpu) = 1; | |
214 | } | |
215 | ||
216 | static int control_ops_alloc(struct ftrace_ops *ops) | |
217 | { | |
218 | int __percpu *disabled; | |
219 | ||
220 | disabled = alloc_percpu(int); | |
221 | if (!disabled) | |
222 | return -ENOMEM; | |
223 | ||
224 | ops->disabled = disabled; | |
225 | control_ops_disable_all(ops); | |
226 | return 0; | |
227 | } | |
228 | ||
405e1d83 SRRH |
229 | static void ftrace_sync(struct work_struct *work) |
230 | { | |
231 | /* | |
232 | * This function is just a stub to implement a hard force | |
233 | * of synchronize_sched(). This requires synchronizing | |
234 | * tasks even in userspace and idle. | |
235 | * | |
236 | * Yes, function tracing is rude. | |
237 | */ | |
238 | } | |
239 | ||
240 | static void ftrace_sync_ipi(void *data) | |
241 | { | |
242 | /* Probably not needed, but do it anyway */ | |
243 | smp_rmb(); | |
244 | } | |
245 | ||
23a8e844 SRRH |
246 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
247 | static void update_function_graph_func(void); | |
248 | #else | |
249 | static inline void update_function_graph_func(void) { } | |
250 | #endif | |
251 | ||
2b499381 SR |
252 | static void update_ftrace_function(void) |
253 | { | |
254 | ftrace_func_t func; | |
255 | ||
f7aad4e1 SRRH |
256 | /* |
257 | * Prepare the ftrace_ops that the arch callback will use. | |
258 | * If there's only one ftrace_ops registered, the ftrace_ops_list | |
259 | * will point to the ops we want. | |
260 | */ | |
261 | set_function_trace_op = ftrace_ops_list; | |
262 | ||
263 | /* If there's no ftrace_ops registered, just call the stub function */ | |
264 | if (ftrace_ops_list == &ftrace_list_end) { | |
265 | func = ftrace_stub; | |
266 | ||
cdbe61bf SR |
267 | /* |
268 | * If we are at the end of the list and this ops is | |
4740974a SR |
269 | * recursion safe and not dynamic and the arch supports passing ops, |
270 | * then have the mcount trampoline call the function directly. | |
cdbe61bf | 271 | */ |
f7aad4e1 | 272 | } else if (ftrace_ops_list->next == &ftrace_list_end) { |
87354059 | 273 | func = ftrace_ops_get_func(ftrace_ops_list); |
f7aad4e1 | 274 | |
2f5f6ad9 SR |
275 | } else { |
276 | /* Just use the default ftrace_ops */ | |
405e1d83 | 277 | set_function_trace_op = &ftrace_list_end; |
b848914c | 278 | func = ftrace_ops_list_func; |
2f5f6ad9 | 279 | } |
2b499381 | 280 | |
5f8bf2d2 SRRH |
281 | update_function_graph_func(); |
282 | ||
405e1d83 SRRH |
283 | /* If there's no change, then do nothing more here */ |
284 | if (ftrace_trace_function == func) | |
285 | return; | |
286 | ||
287 | /* | |
288 | * If we are using the list function, it doesn't care | |
289 | * about the function_trace_ops. | |
290 | */ | |
291 | if (func == ftrace_ops_list_func) { | |
292 | ftrace_trace_function = func; | |
293 | /* | |
294 | * Don't even bother setting function_trace_ops, | |
295 | * it would be racy to do so anyway. | |
296 | */ | |
297 | return; | |
298 | } | |
299 | ||
300 | #ifndef CONFIG_DYNAMIC_FTRACE | |
301 | /* | |
302 | * For static tracing, we need to be a bit more careful. | |
303 | * The function change takes affect immediately. Thus, | |
304 | * we need to coorditate the setting of the function_trace_ops | |
305 | * with the setting of the ftrace_trace_function. | |
306 | * | |
307 | * Set the function to the list ops, which will call the | |
308 | * function we want, albeit indirectly, but it handles the | |
309 | * ftrace_ops and doesn't depend on function_trace_op. | |
310 | */ | |
311 | ftrace_trace_function = ftrace_ops_list_func; | |
312 | /* | |
313 | * Make sure all CPUs see this. Yes this is slow, but static | |
314 | * tracing is slow and nasty to have enabled. | |
315 | */ | |
316 | schedule_on_each_cpu(ftrace_sync); | |
317 | /* Now all cpus are using the list ops. */ | |
318 | function_trace_op = set_function_trace_op; | |
319 | /* Make sure the function_trace_op is visible on all CPUs */ | |
320 | smp_wmb(); | |
321 | /* Nasty way to force a rmb on all cpus */ | |
322 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
323 | /* OK, we are all set to update the ftrace_trace_function now! */ | |
324 | #endif /* !CONFIG_DYNAMIC_FTRACE */ | |
325 | ||
491d0dcf | 326 | ftrace_trace_function = func; |
491d0dcf SR |
327 | } |
328 | ||
7eea4fce JW |
329 | int using_ftrace_ops_list_func(void) |
330 | { | |
331 | return ftrace_trace_function == ftrace_ops_list_func; | |
332 | } | |
333 | ||
2b499381 | 334 | static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
3d083395 | 335 | { |
2b499381 | 336 | ops->next = *list; |
16444a8a | 337 | /* |
b848914c | 338 | * We are entering ops into the list but another |
16444a8a ACM |
339 | * CPU might be walking that list. We need to make sure |
340 | * the ops->next pointer is valid before another CPU sees | |
b848914c | 341 | * the ops pointer included into the list. |
16444a8a | 342 | */ |
2b499381 | 343 | rcu_assign_pointer(*list, ops); |
16444a8a ACM |
344 | } |
345 | ||
2b499381 | 346 | static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
16444a8a | 347 | { |
16444a8a | 348 | struct ftrace_ops **p; |
16444a8a ACM |
349 | |
350 | /* | |
3d083395 SR |
351 | * If we are removing the last function, then simply point |
352 | * to the ftrace_stub. | |
16444a8a | 353 | */ |
2b499381 SR |
354 | if (*list == ops && ops->next == &ftrace_list_end) { |
355 | *list = &ftrace_list_end; | |
e6ea44e9 | 356 | return 0; |
16444a8a ACM |
357 | } |
358 | ||
2b499381 | 359 | for (p = list; *p != &ftrace_list_end; p = &(*p)->next) |
16444a8a ACM |
360 | if (*p == ops) |
361 | break; | |
362 | ||
e6ea44e9 SR |
363 | if (*p != ops) |
364 | return -1; | |
16444a8a ACM |
365 | |
366 | *p = (*p)->next; | |
2b499381 SR |
367 | return 0; |
368 | } | |
16444a8a | 369 | |
e248491a JO |
370 | static void add_ftrace_list_ops(struct ftrace_ops **list, |
371 | struct ftrace_ops *main_ops, | |
372 | struct ftrace_ops *ops) | |
373 | { | |
374 | int first = *list == &ftrace_list_end; | |
375 | add_ftrace_ops(list, ops); | |
376 | if (first) | |
377 | add_ftrace_ops(&ftrace_ops_list, main_ops); | |
378 | } | |
379 | ||
380 | static int remove_ftrace_list_ops(struct ftrace_ops **list, | |
381 | struct ftrace_ops *main_ops, | |
382 | struct ftrace_ops *ops) | |
383 | { | |
384 | int ret = remove_ftrace_ops(list, ops); | |
385 | if (!ret && *list == &ftrace_list_end) | |
386 | ret = remove_ftrace_ops(&ftrace_ops_list, main_ops); | |
387 | return ret; | |
388 | } | |
389 | ||
f3bea491 SRRH |
390 | static void ftrace_update_trampoline(struct ftrace_ops *ops); |
391 | ||
2b499381 SR |
392 | static int __register_ftrace_function(struct ftrace_ops *ops) |
393 | { | |
591dffda SRRH |
394 | if (ops->flags & FTRACE_OPS_FL_DELETED) |
395 | return -EINVAL; | |
396 | ||
b848914c SR |
397 | if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) |
398 | return -EBUSY; | |
399 | ||
06aeaaea | 400 | #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
08f6fba5 SR |
401 | /* |
402 | * If the ftrace_ops specifies SAVE_REGS, then it only can be used | |
403 | * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set. | |
404 | * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant. | |
405 | */ | |
406 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS && | |
407 | !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)) | |
408 | return -EINVAL; | |
409 | ||
410 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED) | |
411 | ops->flags |= FTRACE_OPS_FL_SAVE_REGS; | |
412 | #endif | |
413 | ||
cdbe61bf SR |
414 | if (!core_kernel_data((unsigned long)ops)) |
415 | ops->flags |= FTRACE_OPS_FL_DYNAMIC; | |
416 | ||
4104d326 | 417 | if (ops->flags & FTRACE_OPS_FL_CONTROL) { |
e248491a JO |
418 | if (control_ops_alloc(ops)) |
419 | return -ENOMEM; | |
420 | add_ftrace_list_ops(&ftrace_control_list, &control_ops, ops); | |
fe578ba3 SRRH |
421 | /* The control_ops needs the trampoline update */ |
422 | ops = &control_ops; | |
b848914c SR |
423 | } else |
424 | add_ftrace_ops(&ftrace_ops_list, ops); | |
425 | ||
f3bea491 SRRH |
426 | ftrace_update_trampoline(ops); |
427 | ||
2b499381 SR |
428 | if (ftrace_enabled) |
429 | update_ftrace_function(); | |
430 | ||
431 | return 0; | |
432 | } | |
433 | ||
434 | static int __unregister_ftrace_function(struct ftrace_ops *ops) | |
435 | { | |
436 | int ret; | |
437 | ||
b848914c SR |
438 | if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) |
439 | return -EBUSY; | |
440 | ||
4104d326 | 441 | if (ops->flags & FTRACE_OPS_FL_CONTROL) { |
e248491a JO |
442 | ret = remove_ftrace_list_ops(&ftrace_control_list, |
443 | &control_ops, ops); | |
b848914c SR |
444 | } else |
445 | ret = remove_ftrace_ops(&ftrace_ops_list, ops); | |
446 | ||
2b499381 SR |
447 | if (ret < 0) |
448 | return ret; | |
b848914c | 449 | |
491d0dcf SR |
450 | if (ftrace_enabled) |
451 | update_ftrace_function(); | |
16444a8a | 452 | |
e6ea44e9 | 453 | return 0; |
3d083395 SR |
454 | } |
455 | ||
df4fc315 SR |
456 | static void ftrace_update_pid_func(void) |
457 | { | |
491d0dcf | 458 | /* Only do something if we are tracing something */ |
df4fc315 | 459 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 460 | return; |
df4fc315 | 461 | |
491d0dcf | 462 | update_ftrace_function(); |
df4fc315 SR |
463 | } |
464 | ||
493762fc SR |
465 | #ifdef CONFIG_FUNCTION_PROFILER |
466 | struct ftrace_profile { | |
467 | struct hlist_node node; | |
468 | unsigned long ip; | |
469 | unsigned long counter; | |
0706f1c4 SR |
470 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
471 | unsigned long long time; | |
e330b3bc | 472 | unsigned long long time_squared; |
0706f1c4 | 473 | #endif |
8fc0c701 SR |
474 | }; |
475 | ||
493762fc SR |
476 | struct ftrace_profile_page { |
477 | struct ftrace_profile_page *next; | |
478 | unsigned long index; | |
479 | struct ftrace_profile records[]; | |
d61f82d0 SR |
480 | }; |
481 | ||
cafb168a SR |
482 | struct ftrace_profile_stat { |
483 | atomic_t disabled; | |
484 | struct hlist_head *hash; | |
485 | struct ftrace_profile_page *pages; | |
486 | struct ftrace_profile_page *start; | |
487 | struct tracer_stat stat; | |
488 | }; | |
489 | ||
493762fc SR |
490 | #define PROFILE_RECORDS_SIZE \ |
491 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 492 | |
493762fc SR |
493 | #define PROFILES_PER_PAGE \ |
494 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 495 | |
fb9fb015 SR |
496 | static int ftrace_profile_enabled __read_mostly; |
497 | ||
498 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
499 | static DEFINE_MUTEX(ftrace_profile_lock); |
500 | ||
cafb168a | 501 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc | 502 | |
20079ebe NK |
503 | #define FTRACE_PROFILE_HASH_BITS 10 |
504 | #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS) | |
493762fc | 505 | |
bac429f0 SR |
506 | static void * |
507 | function_stat_next(void *v, int idx) | |
508 | { | |
493762fc SR |
509 | struct ftrace_profile *rec = v; |
510 | struct ftrace_profile_page *pg; | |
bac429f0 | 511 | |
493762fc | 512 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
513 | |
514 | again: | |
0296e425 LZ |
515 | if (idx != 0) |
516 | rec++; | |
517 | ||
bac429f0 SR |
518 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
519 | pg = pg->next; | |
520 | if (!pg) | |
521 | return NULL; | |
522 | rec = &pg->records[0]; | |
493762fc SR |
523 | if (!rec->counter) |
524 | goto again; | |
bac429f0 SR |
525 | } |
526 | ||
bac429f0 SR |
527 | return rec; |
528 | } | |
529 | ||
530 | static void *function_stat_start(struct tracer_stat *trace) | |
531 | { | |
cafb168a SR |
532 | struct ftrace_profile_stat *stat = |
533 | container_of(trace, struct ftrace_profile_stat, stat); | |
534 | ||
535 | if (!stat || !stat->start) | |
536 | return NULL; | |
537 | ||
538 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
539 | } |
540 | ||
0706f1c4 SR |
541 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
542 | /* function graph compares on total time */ | |
543 | static int function_stat_cmp(void *p1, void *p2) | |
544 | { | |
545 | struct ftrace_profile *a = p1; | |
546 | struct ftrace_profile *b = p2; | |
547 | ||
548 | if (a->time < b->time) | |
549 | return -1; | |
550 | if (a->time > b->time) | |
551 | return 1; | |
552 | else | |
553 | return 0; | |
554 | } | |
555 | #else | |
556 | /* not function graph compares against hits */ | |
bac429f0 SR |
557 | static int function_stat_cmp(void *p1, void *p2) |
558 | { | |
493762fc SR |
559 | struct ftrace_profile *a = p1; |
560 | struct ftrace_profile *b = p2; | |
bac429f0 SR |
561 | |
562 | if (a->counter < b->counter) | |
563 | return -1; | |
564 | if (a->counter > b->counter) | |
565 | return 1; | |
566 | else | |
567 | return 0; | |
568 | } | |
0706f1c4 | 569 | #endif |
bac429f0 SR |
570 | |
571 | static int function_stat_headers(struct seq_file *m) | |
572 | { | |
0706f1c4 | 573 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
fa6f0cc7 RV |
574 | seq_puts(m, " Function " |
575 | "Hit Time Avg s^2\n" | |
576 | " -------- " | |
577 | "--- ---- --- ---\n"); | |
0706f1c4 | 578 | #else |
fa6f0cc7 RV |
579 | seq_puts(m, " Function Hit\n" |
580 | " -------- ---\n"); | |
0706f1c4 | 581 | #endif |
bac429f0 SR |
582 | return 0; |
583 | } | |
584 | ||
585 | static int function_stat_show(struct seq_file *m, void *v) | |
586 | { | |
493762fc | 587 | struct ftrace_profile *rec = v; |
bac429f0 | 588 | char str[KSYM_SYMBOL_LEN]; |
3aaba20f | 589 | int ret = 0; |
0706f1c4 | 590 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
591 | static struct trace_seq s; |
592 | unsigned long long avg; | |
e330b3bc | 593 | unsigned long long stddev; |
0706f1c4 | 594 | #endif |
3aaba20f LZ |
595 | mutex_lock(&ftrace_profile_lock); |
596 | ||
597 | /* we raced with function_profile_reset() */ | |
598 | if (unlikely(rec->counter == 0)) { | |
599 | ret = -EBUSY; | |
600 | goto out; | |
601 | } | |
bac429f0 SR |
602 | |
603 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
0706f1c4 SR |
604 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
605 | ||
606 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
fa6f0cc7 | 607 | seq_puts(m, " "); |
34886c8b SR |
608 | avg = rec->time; |
609 | do_div(avg, rec->counter); | |
610 | ||
e330b3bc CD |
611 | /* Sample standard deviation (s^2) */ |
612 | if (rec->counter <= 1) | |
613 | stddev = 0; | |
614 | else { | |
52d85d76 JL |
615 | /* |
616 | * Apply Welford's method: | |
617 | * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2) | |
618 | */ | |
619 | stddev = rec->counter * rec->time_squared - | |
620 | rec->time * rec->time; | |
621 | ||
e330b3bc CD |
622 | /* |
623 | * Divide only 1000 for ns^2 -> us^2 conversion. | |
624 | * trace_print_graph_duration will divide 1000 again. | |
625 | */ | |
52d85d76 | 626 | do_div(stddev, rec->counter * (rec->counter - 1) * 1000); |
e330b3bc CD |
627 | } |
628 | ||
34886c8b SR |
629 | trace_seq_init(&s); |
630 | trace_print_graph_duration(rec->time, &s); | |
631 | trace_seq_puts(&s, " "); | |
632 | trace_print_graph_duration(avg, &s); | |
e330b3bc CD |
633 | trace_seq_puts(&s, " "); |
634 | trace_print_graph_duration(stddev, &s); | |
0706f1c4 | 635 | trace_print_seq(m, &s); |
0706f1c4 SR |
636 | #endif |
637 | seq_putc(m, '\n'); | |
3aaba20f LZ |
638 | out: |
639 | mutex_unlock(&ftrace_profile_lock); | |
bac429f0 | 640 | |
3aaba20f | 641 | return ret; |
bac429f0 SR |
642 | } |
643 | ||
cafb168a | 644 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 645 | { |
493762fc | 646 | struct ftrace_profile_page *pg; |
bac429f0 | 647 | |
cafb168a | 648 | pg = stat->pages = stat->start; |
bac429f0 | 649 | |
493762fc SR |
650 | while (pg) { |
651 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
652 | pg->index = 0; | |
653 | pg = pg->next; | |
bac429f0 SR |
654 | } |
655 | ||
cafb168a | 656 | memset(stat->hash, 0, |
493762fc SR |
657 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
658 | } | |
bac429f0 | 659 | |
cafb168a | 660 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
661 | { |
662 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
663 | int functions; |
664 | int pages; | |
493762fc | 665 | int i; |
bac429f0 | 666 | |
493762fc | 667 | /* If we already allocated, do nothing */ |
cafb168a | 668 | if (stat->pages) |
493762fc | 669 | return 0; |
bac429f0 | 670 | |
cafb168a SR |
671 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
672 | if (!stat->pages) | |
493762fc | 673 | return -ENOMEM; |
bac429f0 | 674 | |
318e0a73 SR |
675 | #ifdef CONFIG_DYNAMIC_FTRACE |
676 | functions = ftrace_update_tot_cnt; | |
677 | #else | |
678 | /* | |
679 | * We do not know the number of functions that exist because | |
680 | * dynamic tracing is what counts them. With past experience | |
681 | * we have around 20K functions. That should be more than enough. | |
682 | * It is highly unlikely we will execute every function in | |
683 | * the kernel. | |
684 | */ | |
685 | functions = 20000; | |
686 | #endif | |
687 | ||
cafb168a | 688 | pg = stat->start = stat->pages; |
bac429f0 | 689 | |
318e0a73 SR |
690 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
691 | ||
39e30cd1 | 692 | for (i = 1; i < pages; i++) { |
493762fc | 693 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 694 | if (!pg->next) |
318e0a73 | 695 | goto out_free; |
493762fc SR |
696 | pg = pg->next; |
697 | } | |
698 | ||
699 | return 0; | |
318e0a73 SR |
700 | |
701 | out_free: | |
702 | pg = stat->start; | |
703 | while (pg) { | |
704 | unsigned long tmp = (unsigned long)pg; | |
705 | ||
706 | pg = pg->next; | |
707 | free_page(tmp); | |
708 | } | |
709 | ||
318e0a73 SR |
710 | stat->pages = NULL; |
711 | stat->start = NULL; | |
712 | ||
713 | return -ENOMEM; | |
bac429f0 SR |
714 | } |
715 | ||
cafb168a | 716 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 717 | { |
cafb168a | 718 | struct ftrace_profile_stat *stat; |
493762fc | 719 | int size; |
bac429f0 | 720 | |
cafb168a SR |
721 | stat = &per_cpu(ftrace_profile_stats, cpu); |
722 | ||
723 | if (stat->hash) { | |
493762fc | 724 | /* If the profile is already created, simply reset it */ |
cafb168a | 725 | ftrace_profile_reset(stat); |
493762fc SR |
726 | return 0; |
727 | } | |
bac429f0 | 728 | |
493762fc SR |
729 | /* |
730 | * We are profiling all functions, but usually only a few thousand | |
731 | * functions are hit. We'll make a hash of 1024 items. | |
732 | */ | |
733 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 734 | |
cafb168a | 735 | stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
493762fc | 736 | |
cafb168a | 737 | if (!stat->hash) |
493762fc SR |
738 | return -ENOMEM; |
739 | ||
318e0a73 | 740 | /* Preallocate the function profiling pages */ |
cafb168a SR |
741 | if (ftrace_profile_pages_init(stat) < 0) { |
742 | kfree(stat->hash); | |
743 | stat->hash = NULL; | |
493762fc SR |
744 | return -ENOMEM; |
745 | } | |
746 | ||
747 | return 0; | |
bac429f0 SR |
748 | } |
749 | ||
cafb168a SR |
750 | static int ftrace_profile_init(void) |
751 | { | |
752 | int cpu; | |
753 | int ret = 0; | |
754 | ||
c4602c1c | 755 | for_each_possible_cpu(cpu) { |
cafb168a SR |
756 | ret = ftrace_profile_init_cpu(cpu); |
757 | if (ret) | |
758 | break; | |
759 | } | |
760 | ||
761 | return ret; | |
762 | } | |
763 | ||
493762fc | 764 | /* interrupts must be disabled */ |
cafb168a SR |
765 | static struct ftrace_profile * |
766 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 767 | { |
493762fc | 768 | struct ftrace_profile *rec; |
bac429f0 | 769 | struct hlist_head *hhd; |
bac429f0 SR |
770 | unsigned long key; |
771 | ||
20079ebe | 772 | key = hash_long(ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 773 | hhd = &stat->hash[key]; |
bac429f0 SR |
774 | |
775 | if (hlist_empty(hhd)) | |
776 | return NULL; | |
777 | ||
1bb539ca | 778 | hlist_for_each_entry_rcu_notrace(rec, hhd, node) { |
bac429f0 | 779 | if (rec->ip == ip) |
493762fc SR |
780 | return rec; |
781 | } | |
782 | ||
783 | return NULL; | |
784 | } | |
785 | ||
cafb168a SR |
786 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
787 | struct ftrace_profile *rec) | |
493762fc SR |
788 | { |
789 | unsigned long key; | |
790 | ||
20079ebe | 791 | key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 792 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
793 | } |
794 | ||
318e0a73 SR |
795 | /* |
796 | * The memory is already allocated, this simply finds a new record to use. | |
797 | */ | |
493762fc | 798 | static struct ftrace_profile * |
318e0a73 | 799 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
800 | { |
801 | struct ftrace_profile *rec = NULL; | |
802 | ||
318e0a73 | 803 | /* prevent recursion (from NMIs) */ |
cafb168a | 804 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
805 | goto out; |
806 | ||
493762fc | 807 | /* |
318e0a73 SR |
808 | * Try to find the function again since an NMI |
809 | * could have added it | |
493762fc | 810 | */ |
cafb168a | 811 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 812 | if (rec) |
cafb168a | 813 | goto out; |
493762fc | 814 | |
cafb168a SR |
815 | if (stat->pages->index == PROFILES_PER_PAGE) { |
816 | if (!stat->pages->next) | |
817 | goto out; | |
818 | stat->pages = stat->pages->next; | |
bac429f0 | 819 | } |
493762fc | 820 | |
cafb168a | 821 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 822 | rec->ip = ip; |
cafb168a | 823 | ftrace_add_profile(stat, rec); |
493762fc | 824 | |
bac429f0 | 825 | out: |
cafb168a | 826 | atomic_dec(&stat->disabled); |
bac429f0 SR |
827 | |
828 | return rec; | |
829 | } | |
830 | ||
831 | static void | |
2f5f6ad9 | 832 | function_profile_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 833 | struct ftrace_ops *ops, struct pt_regs *regs) |
bac429f0 | 834 | { |
cafb168a | 835 | struct ftrace_profile_stat *stat; |
493762fc | 836 | struct ftrace_profile *rec; |
bac429f0 SR |
837 | unsigned long flags; |
838 | ||
839 | if (!ftrace_profile_enabled) | |
840 | return; | |
841 | ||
842 | local_irq_save(flags); | |
cafb168a | 843 | |
bdffd893 | 844 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 845 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
846 | goto out; |
847 | ||
848 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 849 | if (!rec) { |
318e0a73 | 850 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
851 | if (!rec) |
852 | goto out; | |
853 | } | |
bac429f0 SR |
854 | |
855 | rec->counter++; | |
856 | out: | |
857 | local_irq_restore(flags); | |
858 | } | |
859 | ||
0706f1c4 SR |
860 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
861 | static int profile_graph_entry(struct ftrace_graph_ent *trace) | |
862 | { | |
a1e2e31d | 863 | function_profile_call(trace->func, 0, NULL, NULL); |
0706f1c4 SR |
864 | return 1; |
865 | } | |
866 | ||
867 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
868 | { | |
cafb168a | 869 | struct ftrace_profile_stat *stat; |
a2a16d6a | 870 | unsigned long long calltime; |
0706f1c4 | 871 | struct ftrace_profile *rec; |
cafb168a | 872 | unsigned long flags; |
0706f1c4 SR |
873 | |
874 | local_irq_save(flags); | |
bdffd893 | 875 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 876 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
877 | goto out; |
878 | ||
37e44bc5 SR |
879 | /* If the calltime was zero'd ignore it */ |
880 | if (!trace->calltime) | |
881 | goto out; | |
882 | ||
a2a16d6a SR |
883 | calltime = trace->rettime - trace->calltime; |
884 | ||
885 | if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) { | |
886 | int index; | |
887 | ||
888 | index = trace->depth; | |
889 | ||
890 | /* Append this call time to the parent time to subtract */ | |
891 | if (index) | |
892 | current->ret_stack[index - 1].subtime += calltime; | |
893 | ||
894 | if (current->ret_stack[index].subtime < calltime) | |
895 | calltime -= current->ret_stack[index].subtime; | |
896 | else | |
897 | calltime = 0; | |
898 | } | |
899 | ||
cafb168a | 900 | rec = ftrace_find_profiled_func(stat, trace->func); |
e330b3bc | 901 | if (rec) { |
a2a16d6a | 902 | rec->time += calltime; |
e330b3bc CD |
903 | rec->time_squared += calltime * calltime; |
904 | } | |
a2a16d6a | 905 | |
cafb168a | 906 | out: |
0706f1c4 SR |
907 | local_irq_restore(flags); |
908 | } | |
909 | ||
910 | static int register_ftrace_profiler(void) | |
911 | { | |
912 | return register_ftrace_graph(&profile_graph_return, | |
913 | &profile_graph_entry); | |
914 | } | |
915 | ||
916 | static void unregister_ftrace_profiler(void) | |
917 | { | |
918 | unregister_ftrace_graph(); | |
919 | } | |
920 | #else | |
bd38c0e6 | 921 | static struct ftrace_ops ftrace_profile_ops __read_mostly = { |
fb9fb015 | 922 | .func = function_profile_call, |
f04f24fb | 923 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, |
33b7f99c | 924 | INIT_OPS_HASH(ftrace_profile_ops) |
bac429f0 SR |
925 | }; |
926 | ||
0706f1c4 SR |
927 | static int register_ftrace_profiler(void) |
928 | { | |
929 | return register_ftrace_function(&ftrace_profile_ops); | |
930 | } | |
931 | ||
932 | static void unregister_ftrace_profiler(void) | |
933 | { | |
934 | unregister_ftrace_function(&ftrace_profile_ops); | |
935 | } | |
936 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
937 | ||
bac429f0 SR |
938 | static ssize_t |
939 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
940 | size_t cnt, loff_t *ppos) | |
941 | { | |
942 | unsigned long val; | |
bac429f0 SR |
943 | int ret; |
944 | ||
22fe9b54 PH |
945 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
946 | if (ret) | |
bac429f0 SR |
947 | return ret; |
948 | ||
949 | val = !!val; | |
950 | ||
951 | mutex_lock(&ftrace_profile_lock); | |
952 | if (ftrace_profile_enabled ^ val) { | |
953 | if (val) { | |
493762fc SR |
954 | ret = ftrace_profile_init(); |
955 | if (ret < 0) { | |
956 | cnt = ret; | |
957 | goto out; | |
958 | } | |
959 | ||
0706f1c4 SR |
960 | ret = register_ftrace_profiler(); |
961 | if (ret < 0) { | |
962 | cnt = ret; | |
963 | goto out; | |
964 | } | |
bac429f0 SR |
965 | ftrace_profile_enabled = 1; |
966 | } else { | |
967 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
968 | /* |
969 | * unregister_ftrace_profiler calls stop_machine | |
970 | * so this acts like an synchronize_sched. | |
971 | */ | |
0706f1c4 | 972 | unregister_ftrace_profiler(); |
bac429f0 SR |
973 | } |
974 | } | |
493762fc | 975 | out: |
bac429f0 SR |
976 | mutex_unlock(&ftrace_profile_lock); |
977 | ||
cf8517cf | 978 | *ppos += cnt; |
bac429f0 SR |
979 | |
980 | return cnt; | |
981 | } | |
982 | ||
493762fc SR |
983 | static ssize_t |
984 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
985 | size_t cnt, loff_t *ppos) | |
986 | { | |
fb9fb015 | 987 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
988 | int r; |
989 | ||
990 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
991 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
992 | } | |
993 | ||
bac429f0 SR |
994 | static const struct file_operations ftrace_profile_fops = { |
995 | .open = tracing_open_generic, | |
996 | .read = ftrace_profile_read, | |
997 | .write = ftrace_profile_write, | |
6038f373 | 998 | .llseek = default_llseek, |
bac429f0 SR |
999 | }; |
1000 | ||
cafb168a SR |
1001 | /* used to initialize the real stat files */ |
1002 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
1003 | .name = "functions", |
1004 | .stat_start = function_stat_start, | |
1005 | .stat_next = function_stat_next, | |
1006 | .stat_cmp = function_stat_cmp, | |
1007 | .stat_headers = function_stat_headers, | |
1008 | .stat_show = function_stat_show | |
cafb168a SR |
1009 | }; |
1010 | ||
6ab5d668 | 1011 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 | 1012 | { |
cafb168a | 1013 | struct ftrace_profile_stat *stat; |
bac429f0 | 1014 | struct dentry *entry; |
cafb168a | 1015 | char *name; |
bac429f0 | 1016 | int ret; |
cafb168a SR |
1017 | int cpu; |
1018 | ||
1019 | for_each_possible_cpu(cpu) { | |
1020 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
1021 | ||
1022 | /* allocate enough for function name + cpu number */ | |
1023 | name = kmalloc(32, GFP_KERNEL); | |
1024 | if (!name) { | |
1025 | /* | |
1026 | * The files created are permanent, if something happens | |
1027 | * we still do not free memory. | |
1028 | */ | |
cafb168a SR |
1029 | WARN(1, |
1030 | "Could not allocate stat file for cpu %d\n", | |
1031 | cpu); | |
1032 | return; | |
1033 | } | |
1034 | stat->stat = function_stats; | |
1035 | snprintf(name, 32, "function%d", cpu); | |
1036 | stat->stat.name = name; | |
1037 | ret = register_stat_tracer(&stat->stat); | |
1038 | if (ret) { | |
1039 | WARN(1, | |
1040 | "Could not register function stat for cpu %d\n", | |
1041 | cpu); | |
1042 | kfree(name); | |
1043 | return; | |
1044 | } | |
bac429f0 SR |
1045 | } |
1046 | ||
1047 | entry = debugfs_create_file("function_profile_enabled", 0644, | |
1048 | d_tracer, NULL, &ftrace_profile_fops); | |
1049 | if (!entry) | |
1050 | pr_warning("Could not create debugfs " | |
1051 | "'function_profile_enabled' entry\n"); | |
1052 | } | |
1053 | ||
bac429f0 | 1054 | #else /* CONFIG_FUNCTION_PROFILER */ |
6ab5d668 | 1055 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 SR |
1056 | { |
1057 | } | |
bac429f0 SR |
1058 | #endif /* CONFIG_FUNCTION_PROFILER */ |
1059 | ||
493762fc SR |
1060 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; |
1061 | ||
1619dc3f PA |
1062 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
1063 | static int ftrace_graph_active; | |
1064 | #else | |
1065 | # define ftrace_graph_active 0 | |
1066 | #endif | |
1067 | ||
493762fc SR |
1068 | #ifdef CONFIG_DYNAMIC_FTRACE |
1069 | ||
79922b80 SRRH |
1070 | static struct ftrace_ops *removed_ops; |
1071 | ||
e1effa01 SRRH |
1072 | /* |
1073 | * Set when doing a global update, like enabling all recs or disabling them. | |
1074 | * It is not set when just updating a single ftrace_ops. | |
1075 | */ | |
1076 | static bool update_all_ops; | |
1077 | ||
493762fc SR |
1078 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
1079 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
1080 | #endif | |
1081 | ||
1082 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; | |
1083 | ||
1084 | struct ftrace_func_probe { | |
1085 | struct hlist_node node; | |
1086 | struct ftrace_probe_ops *ops; | |
1087 | unsigned long flags; | |
1088 | unsigned long ip; | |
1089 | void *data; | |
7818b388 | 1090 | struct list_head free_list; |
493762fc SR |
1091 | }; |
1092 | ||
b448c4e3 SR |
1093 | struct ftrace_func_entry { |
1094 | struct hlist_node hlist; | |
1095 | unsigned long ip; | |
1096 | }; | |
1097 | ||
1098 | struct ftrace_hash { | |
1099 | unsigned long size_bits; | |
1100 | struct hlist_head *buckets; | |
1101 | unsigned long count; | |
07fd5515 | 1102 | struct rcu_head rcu; |
b448c4e3 SR |
1103 | }; |
1104 | ||
33dc9b12 SR |
1105 | /* |
1106 | * We make these constant because no one should touch them, | |
1107 | * but they are used as the default "empty hash", to avoid allocating | |
1108 | * it all the time. These are in a read only section such that if | |
1109 | * anyone does try to modify it, it will cause an exception. | |
1110 | */ | |
1111 | static const struct hlist_head empty_buckets[1]; | |
1112 | static const struct ftrace_hash empty_hash = { | |
1113 | .buckets = (struct hlist_head *)empty_buckets, | |
1cf41dd7 | 1114 | }; |
33dc9b12 | 1115 | #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash) |
493762fc | 1116 | |
2b499381 | 1117 | static struct ftrace_ops global_ops = { |
33b7f99c SRRH |
1118 | .func = ftrace_stub, |
1119 | .local_hash.notrace_hash = EMPTY_HASH, | |
1120 | .local_hash.filter_hash = EMPTY_HASH, | |
1121 | INIT_OPS_HASH(global_ops) | |
1122 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | | |
1123 | FTRACE_OPS_FL_INITIALIZED, | |
f45948e8 SR |
1124 | }; |
1125 | ||
aec0be2d SRRH |
1126 | /* |
1127 | * This is used by __kernel_text_address() to return true if the | |
0af26492 | 1128 | * address is on a dynamically allocated trampoline that would |
aec0be2d SRRH |
1129 | * not return true for either core_kernel_text() or |
1130 | * is_module_text_address(). | |
1131 | */ | |
1132 | bool is_ftrace_trampoline(unsigned long addr) | |
1133 | { | |
1134 | struct ftrace_ops *op; | |
1135 | bool ret = false; | |
1136 | ||
1137 | /* | |
1138 | * Some of the ops may be dynamically allocated, | |
1139 | * they are freed after a synchronize_sched(). | |
1140 | */ | |
1141 | preempt_disable_notrace(); | |
1142 | ||
1143 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1144 | /* | |
1145 | * This is to check for dynamically allocated trampolines. | |
1146 | * Trampolines that are in kernel text will have | |
1147 | * core_kernel_text() return true. | |
1148 | */ | |
1149 | if (op->trampoline && op->trampoline_size) | |
1150 | if (addr >= op->trampoline && | |
1151 | addr < op->trampoline + op->trampoline_size) { | |
1152 | ret = true; | |
1153 | goto out; | |
1154 | } | |
1155 | } while_for_each_ftrace_op(op); | |
1156 | ||
1157 | out: | |
1158 | preempt_enable_notrace(); | |
1159 | ||
1160 | return ret; | |
1161 | } | |
1162 | ||
493762fc SR |
1163 | struct ftrace_page { |
1164 | struct ftrace_page *next; | |
a7900875 | 1165 | struct dyn_ftrace *records; |
493762fc | 1166 | int index; |
a7900875 | 1167 | int size; |
493762fc SR |
1168 | }; |
1169 | ||
a7900875 SR |
1170 | #define ENTRY_SIZE sizeof(struct dyn_ftrace) |
1171 | #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE) | |
493762fc SR |
1172 | |
1173 | /* estimate from running different kernels */ | |
1174 | #define NR_TO_INIT 10000 | |
1175 | ||
1176 | static struct ftrace_page *ftrace_pages_start; | |
1177 | static struct ftrace_page *ftrace_pages; | |
1178 | ||
68f40969 | 1179 | static bool __always_inline ftrace_hash_empty(struct ftrace_hash *hash) |
06a51d93 SR |
1180 | { |
1181 | return !hash || !hash->count; | |
1182 | } | |
1183 | ||
b448c4e3 SR |
1184 | static struct ftrace_func_entry * |
1185 | ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
1186 | { | |
1187 | unsigned long key; | |
1188 | struct ftrace_func_entry *entry; | |
1189 | struct hlist_head *hhd; | |
b448c4e3 | 1190 | |
06a51d93 | 1191 | if (ftrace_hash_empty(hash)) |
b448c4e3 SR |
1192 | return NULL; |
1193 | ||
1194 | if (hash->size_bits > 0) | |
1195 | key = hash_long(ip, hash->size_bits); | |
1196 | else | |
1197 | key = 0; | |
1198 | ||
1199 | hhd = &hash->buckets[key]; | |
1200 | ||
1bb539ca | 1201 | hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) { |
b448c4e3 SR |
1202 | if (entry->ip == ip) |
1203 | return entry; | |
1204 | } | |
1205 | return NULL; | |
1206 | } | |
1207 | ||
33dc9b12 SR |
1208 | static void __add_hash_entry(struct ftrace_hash *hash, |
1209 | struct ftrace_func_entry *entry) | |
b448c4e3 | 1210 | { |
b448c4e3 SR |
1211 | struct hlist_head *hhd; |
1212 | unsigned long key; | |
1213 | ||
b448c4e3 | 1214 | if (hash->size_bits) |
33dc9b12 | 1215 | key = hash_long(entry->ip, hash->size_bits); |
b448c4e3 SR |
1216 | else |
1217 | key = 0; | |
1218 | ||
b448c4e3 SR |
1219 | hhd = &hash->buckets[key]; |
1220 | hlist_add_head(&entry->hlist, hhd); | |
1221 | hash->count++; | |
33dc9b12 SR |
1222 | } |
1223 | ||
1224 | static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip) | |
1225 | { | |
1226 | struct ftrace_func_entry *entry; | |
1227 | ||
1228 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1229 | if (!entry) | |
1230 | return -ENOMEM; | |
1231 | ||
1232 | entry->ip = ip; | |
1233 | __add_hash_entry(hash, entry); | |
b448c4e3 SR |
1234 | |
1235 | return 0; | |
1236 | } | |
1237 | ||
1238 | static void | |
33dc9b12 | 1239 | free_hash_entry(struct ftrace_hash *hash, |
b448c4e3 SR |
1240 | struct ftrace_func_entry *entry) |
1241 | { | |
1242 | hlist_del(&entry->hlist); | |
1243 | kfree(entry); | |
1244 | hash->count--; | |
1245 | } | |
1246 | ||
33dc9b12 SR |
1247 | static void |
1248 | remove_hash_entry(struct ftrace_hash *hash, | |
1249 | struct ftrace_func_entry *entry) | |
1250 | { | |
1251 | hlist_del(&entry->hlist); | |
1252 | hash->count--; | |
1253 | } | |
1254 | ||
b448c4e3 SR |
1255 | static void ftrace_hash_clear(struct ftrace_hash *hash) |
1256 | { | |
1257 | struct hlist_head *hhd; | |
b67bfe0d | 1258 | struct hlist_node *tn; |
b448c4e3 SR |
1259 | struct ftrace_func_entry *entry; |
1260 | int size = 1 << hash->size_bits; | |
1261 | int i; | |
1262 | ||
33dc9b12 SR |
1263 | if (!hash->count) |
1264 | return; | |
1265 | ||
b448c4e3 SR |
1266 | for (i = 0; i < size; i++) { |
1267 | hhd = &hash->buckets[i]; | |
b67bfe0d | 1268 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) |
33dc9b12 | 1269 | free_hash_entry(hash, entry); |
b448c4e3 SR |
1270 | } |
1271 | FTRACE_WARN_ON(hash->count); | |
1272 | } | |
1273 | ||
33dc9b12 SR |
1274 | static void free_ftrace_hash(struct ftrace_hash *hash) |
1275 | { | |
1276 | if (!hash || hash == EMPTY_HASH) | |
1277 | return; | |
1278 | ftrace_hash_clear(hash); | |
1279 | kfree(hash->buckets); | |
1280 | kfree(hash); | |
1281 | } | |
1282 | ||
07fd5515 SR |
1283 | static void __free_ftrace_hash_rcu(struct rcu_head *rcu) |
1284 | { | |
1285 | struct ftrace_hash *hash; | |
1286 | ||
1287 | hash = container_of(rcu, struct ftrace_hash, rcu); | |
1288 | free_ftrace_hash(hash); | |
1289 | } | |
1290 | ||
1291 | static void free_ftrace_hash_rcu(struct ftrace_hash *hash) | |
1292 | { | |
1293 | if (!hash || hash == EMPTY_HASH) | |
1294 | return; | |
1295 | call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu); | |
1296 | } | |
1297 | ||
5500fa51 JO |
1298 | void ftrace_free_filter(struct ftrace_ops *ops) |
1299 | { | |
f04f24fb | 1300 | ftrace_ops_init(ops); |
33b7f99c SRRH |
1301 | free_ftrace_hash(ops->func_hash->filter_hash); |
1302 | free_ftrace_hash(ops->func_hash->notrace_hash); | |
5500fa51 JO |
1303 | } |
1304 | ||
33dc9b12 SR |
1305 | static struct ftrace_hash *alloc_ftrace_hash(int size_bits) |
1306 | { | |
1307 | struct ftrace_hash *hash; | |
1308 | int size; | |
1309 | ||
1310 | hash = kzalloc(sizeof(*hash), GFP_KERNEL); | |
1311 | if (!hash) | |
1312 | return NULL; | |
1313 | ||
1314 | size = 1 << size_bits; | |
47b0edcb | 1315 | hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL); |
33dc9b12 SR |
1316 | |
1317 | if (!hash->buckets) { | |
1318 | kfree(hash); | |
1319 | return NULL; | |
1320 | } | |
1321 | ||
1322 | hash->size_bits = size_bits; | |
1323 | ||
1324 | return hash; | |
1325 | } | |
1326 | ||
1327 | static struct ftrace_hash * | |
1328 | alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) | |
1329 | { | |
1330 | struct ftrace_func_entry *entry; | |
1331 | struct ftrace_hash *new_hash; | |
33dc9b12 SR |
1332 | int size; |
1333 | int ret; | |
1334 | int i; | |
1335 | ||
1336 | new_hash = alloc_ftrace_hash(size_bits); | |
1337 | if (!new_hash) | |
1338 | return NULL; | |
1339 | ||
1340 | /* Empty hash? */ | |
06a51d93 | 1341 | if (ftrace_hash_empty(hash)) |
33dc9b12 SR |
1342 | return new_hash; |
1343 | ||
1344 | size = 1 << hash->size_bits; | |
1345 | for (i = 0; i < size; i++) { | |
b67bfe0d | 1346 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { |
33dc9b12 SR |
1347 | ret = add_hash_entry(new_hash, entry->ip); |
1348 | if (ret < 0) | |
1349 | goto free_hash; | |
1350 | } | |
1351 | } | |
1352 | ||
1353 | FTRACE_WARN_ON(new_hash->count != hash->count); | |
1354 | ||
1355 | return new_hash; | |
1356 | ||
1357 | free_hash: | |
1358 | free_ftrace_hash(new_hash); | |
1359 | return NULL; | |
1360 | } | |
1361 | ||
41fb61c2 | 1362 | static void |
84261912 | 1363 | ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash); |
41fb61c2 | 1364 | static void |
84261912 | 1365 | ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash); |
41fb61c2 | 1366 | |
f8b8be8a MH |
1367 | static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, |
1368 | struct ftrace_hash *new_hash); | |
1369 | ||
33dc9b12 | 1370 | static int |
41fb61c2 SR |
1371 | ftrace_hash_move(struct ftrace_ops *ops, int enable, |
1372 | struct ftrace_hash **dst, struct ftrace_hash *src) | |
33dc9b12 SR |
1373 | { |
1374 | struct ftrace_func_entry *entry; | |
b67bfe0d | 1375 | struct hlist_node *tn; |
33dc9b12 | 1376 | struct hlist_head *hhd; |
07fd5515 | 1377 | struct ftrace_hash *new_hash; |
33dc9b12 SR |
1378 | int size = src->count; |
1379 | int bits = 0; | |
f8b8be8a | 1380 | int ret; |
33dc9b12 SR |
1381 | int i; |
1382 | ||
f8b8be8a MH |
1383 | /* Reject setting notrace hash on IPMODIFY ftrace_ops */ |
1384 | if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable) | |
1385 | return -EINVAL; | |
1386 | ||
33dc9b12 SR |
1387 | /* |
1388 | * If the new source is empty, just free dst and assign it | |
1389 | * the empty_hash. | |
1390 | */ | |
1391 | if (!src->count) { | |
5c27c775 MH |
1392 | new_hash = EMPTY_HASH; |
1393 | goto update; | |
33dc9b12 SR |
1394 | } |
1395 | ||
33dc9b12 SR |
1396 | /* |
1397 | * Make the hash size about 1/2 the # found | |
1398 | */ | |
1399 | for (size /= 2; size; size >>= 1) | |
1400 | bits++; | |
1401 | ||
1402 | /* Don't allocate too much */ | |
1403 | if (bits > FTRACE_HASH_MAX_BITS) | |
1404 | bits = FTRACE_HASH_MAX_BITS; | |
1405 | ||
07fd5515 SR |
1406 | new_hash = alloc_ftrace_hash(bits); |
1407 | if (!new_hash) | |
5c27c775 | 1408 | return -ENOMEM; |
33dc9b12 SR |
1409 | |
1410 | size = 1 << src->size_bits; | |
1411 | for (i = 0; i < size; i++) { | |
1412 | hhd = &src->buckets[i]; | |
b67bfe0d | 1413 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) { |
33dc9b12 | 1414 | remove_hash_entry(src, entry); |
07fd5515 | 1415 | __add_hash_entry(new_hash, entry); |
33dc9b12 SR |
1416 | } |
1417 | } | |
1418 | ||
5c27c775 | 1419 | update: |
f8b8be8a MH |
1420 | /* Make sure this can be applied if it is IPMODIFY ftrace_ops */ |
1421 | if (enable) { | |
1422 | /* IPMODIFY should be updated only when filter_hash updating */ | |
1423 | ret = ftrace_hash_ipmodify_update(ops, new_hash); | |
1424 | if (ret < 0) { | |
1425 | free_ftrace_hash(new_hash); | |
1426 | return ret; | |
1427 | } | |
1428 | } | |
1429 | ||
5c27c775 MH |
1430 | /* |
1431 | * Remove the current set, update the hash and add | |
1432 | * them back. | |
1433 | */ | |
84261912 | 1434 | ftrace_hash_rec_disable_modify(ops, enable); |
5c27c775 | 1435 | |
07fd5515 | 1436 | rcu_assign_pointer(*dst, new_hash); |
07fd5515 | 1437 | |
84261912 | 1438 | ftrace_hash_rec_enable_modify(ops, enable); |
41fb61c2 | 1439 | |
5c27c775 | 1440 | return 0; |
33dc9b12 SR |
1441 | } |
1442 | ||
fef5aeee SRRH |
1443 | static bool hash_contains_ip(unsigned long ip, |
1444 | struct ftrace_ops_hash *hash) | |
1445 | { | |
1446 | /* | |
1447 | * The function record is a match if it exists in the filter | |
1448 | * hash and not in the notrace hash. Note, an emty hash is | |
1449 | * considered a match for the filter hash, but an empty | |
1450 | * notrace hash is considered not in the notrace hash. | |
1451 | */ | |
1452 | return (ftrace_hash_empty(hash->filter_hash) || | |
1453 | ftrace_lookup_ip(hash->filter_hash, ip)) && | |
1454 | (ftrace_hash_empty(hash->notrace_hash) || | |
1455 | !ftrace_lookup_ip(hash->notrace_hash, ip)); | |
1456 | } | |
1457 | ||
b848914c SR |
1458 | /* |
1459 | * Test the hashes for this ops to see if we want to call | |
1460 | * the ops->func or not. | |
1461 | * | |
1462 | * It's a match if the ip is in the ops->filter_hash or | |
1463 | * the filter_hash does not exist or is empty, | |
1464 | * AND | |
1465 | * the ip is not in the ops->notrace_hash. | |
cdbe61bf SR |
1466 | * |
1467 | * This needs to be called with preemption disabled as | |
1468 | * the hashes are freed with call_rcu_sched(). | |
b848914c SR |
1469 | */ |
1470 | static int | |
195a8afc | 1471 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
b848914c | 1472 | { |
fef5aeee | 1473 | struct ftrace_ops_hash hash; |
b848914c SR |
1474 | int ret; |
1475 | ||
195a8afc SRRH |
1476 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
1477 | /* | |
1478 | * There's a small race when adding ops that the ftrace handler | |
1479 | * that wants regs, may be called without them. We can not | |
1480 | * allow that handler to be called if regs is NULL. | |
1481 | */ | |
1482 | if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS)) | |
1483 | return 0; | |
1484 | #endif | |
1485 | ||
fef5aeee SRRH |
1486 | hash.filter_hash = rcu_dereference_raw_notrace(ops->func_hash->filter_hash); |
1487 | hash.notrace_hash = rcu_dereference_raw_notrace(ops->func_hash->notrace_hash); | |
b848914c | 1488 | |
fef5aeee | 1489 | if (hash_contains_ip(ip, &hash)) |
b848914c SR |
1490 | ret = 1; |
1491 | else | |
1492 | ret = 0; | |
b848914c SR |
1493 | |
1494 | return ret; | |
1495 | } | |
1496 | ||
493762fc SR |
1497 | /* |
1498 | * This is a double for. Do not use 'break' to break out of the loop, | |
1499 | * you must use a goto. | |
1500 | */ | |
1501 | #define do_for_each_ftrace_rec(pg, rec) \ | |
1502 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
1503 | int _____i; \ | |
1504 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
1505 | rec = &pg->records[_____i]; | |
1506 | ||
1507 | #define while_for_each_ftrace_rec() \ | |
1508 | } \ | |
1509 | } | |
1510 | ||
5855fead SR |
1511 | |
1512 | static int ftrace_cmp_recs(const void *a, const void *b) | |
1513 | { | |
a650e02a SR |
1514 | const struct dyn_ftrace *key = a; |
1515 | const struct dyn_ftrace *rec = b; | |
5855fead | 1516 | |
a650e02a | 1517 | if (key->flags < rec->ip) |
5855fead | 1518 | return -1; |
a650e02a SR |
1519 | if (key->ip >= rec->ip + MCOUNT_INSN_SIZE) |
1520 | return 1; | |
5855fead SR |
1521 | return 0; |
1522 | } | |
1523 | ||
f0cf973a | 1524 | static unsigned long ftrace_location_range(unsigned long start, unsigned long end) |
c88fd863 SR |
1525 | { |
1526 | struct ftrace_page *pg; | |
1527 | struct dyn_ftrace *rec; | |
5855fead | 1528 | struct dyn_ftrace key; |
c88fd863 | 1529 | |
a650e02a SR |
1530 | key.ip = start; |
1531 | key.flags = end; /* overload flags, as it is unsigned long */ | |
5855fead SR |
1532 | |
1533 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
a650e02a SR |
1534 | if (end < pg->records[0].ip || |
1535 | start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) | |
9644302e | 1536 | continue; |
5855fead SR |
1537 | rec = bsearch(&key, pg->records, pg->index, |
1538 | sizeof(struct dyn_ftrace), | |
1539 | ftrace_cmp_recs); | |
1540 | if (rec) | |
f0cf973a | 1541 | return rec->ip; |
5855fead | 1542 | } |
c88fd863 SR |
1543 | |
1544 | return 0; | |
1545 | } | |
1546 | ||
a650e02a SR |
1547 | /** |
1548 | * ftrace_location - return true if the ip giving is a traced location | |
1549 | * @ip: the instruction pointer to check | |
1550 | * | |
f0cf973a | 1551 | * Returns rec->ip if @ip given is a pointer to a ftrace location. |
a650e02a SR |
1552 | * That is, the instruction that is either a NOP or call to |
1553 | * the function tracer. It checks the ftrace internal tables to | |
1554 | * determine if the address belongs or not. | |
1555 | */ | |
f0cf973a | 1556 | unsigned long ftrace_location(unsigned long ip) |
a650e02a SR |
1557 | { |
1558 | return ftrace_location_range(ip, ip); | |
1559 | } | |
1560 | ||
1561 | /** | |
1562 | * ftrace_text_reserved - return true if range contains an ftrace location | |
1563 | * @start: start of range to search | |
1564 | * @end: end of range to search (inclusive). @end points to the last byte to check. | |
1565 | * | |
1566 | * Returns 1 if @start and @end contains a ftrace location. | |
1567 | * That is, the instruction that is either a NOP or call to | |
1568 | * the function tracer. It checks the ftrace internal tables to | |
1569 | * determine if the address belongs or not. | |
1570 | */ | |
d88471cb | 1571 | int ftrace_text_reserved(const void *start, const void *end) |
a650e02a | 1572 | { |
f0cf973a SR |
1573 | unsigned long ret; |
1574 | ||
1575 | ret = ftrace_location_range((unsigned long)start, | |
1576 | (unsigned long)end); | |
1577 | ||
1578 | return (int)!!ret; | |
a650e02a SR |
1579 | } |
1580 | ||
4fbb48cb SRRH |
1581 | /* Test if ops registered to this rec needs regs */ |
1582 | static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec) | |
1583 | { | |
1584 | struct ftrace_ops *ops; | |
1585 | bool keep_regs = false; | |
1586 | ||
1587 | for (ops = ftrace_ops_list; | |
1588 | ops != &ftrace_list_end; ops = ops->next) { | |
1589 | /* pass rec in as regs to have non-NULL val */ | |
1590 | if (ftrace_ops_test(ops, rec->ip, rec)) { | |
1591 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1592 | keep_regs = true; | |
1593 | break; | |
1594 | } | |
1595 | } | |
1596 | } | |
1597 | ||
1598 | return keep_regs; | |
1599 | } | |
1600 | ||
ed926f9b SR |
1601 | static void __ftrace_hash_rec_update(struct ftrace_ops *ops, |
1602 | int filter_hash, | |
1603 | bool inc) | |
1604 | { | |
1605 | struct ftrace_hash *hash; | |
1606 | struct ftrace_hash *other_hash; | |
1607 | struct ftrace_page *pg; | |
1608 | struct dyn_ftrace *rec; | |
1609 | int count = 0; | |
1610 | int all = 0; | |
1611 | ||
1612 | /* Only update if the ops has been registered */ | |
1613 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
1614 | return; | |
1615 | ||
1616 | /* | |
1617 | * In the filter_hash case: | |
1618 | * If the count is zero, we update all records. | |
1619 | * Otherwise we just update the items in the hash. | |
1620 | * | |
1621 | * In the notrace_hash case: | |
1622 | * We enable the update in the hash. | |
1623 | * As disabling notrace means enabling the tracing, | |
1624 | * and enabling notrace means disabling, the inc variable | |
1625 | * gets inversed. | |
1626 | */ | |
1627 | if (filter_hash) { | |
33b7f99c SRRH |
1628 | hash = ops->func_hash->filter_hash; |
1629 | other_hash = ops->func_hash->notrace_hash; | |
06a51d93 | 1630 | if (ftrace_hash_empty(hash)) |
ed926f9b SR |
1631 | all = 1; |
1632 | } else { | |
1633 | inc = !inc; | |
33b7f99c SRRH |
1634 | hash = ops->func_hash->notrace_hash; |
1635 | other_hash = ops->func_hash->filter_hash; | |
ed926f9b SR |
1636 | /* |
1637 | * If the notrace hash has no items, | |
1638 | * then there's nothing to do. | |
1639 | */ | |
06a51d93 | 1640 | if (ftrace_hash_empty(hash)) |
ed926f9b SR |
1641 | return; |
1642 | } | |
1643 | ||
1644 | do_for_each_ftrace_rec(pg, rec) { | |
1645 | int in_other_hash = 0; | |
1646 | int in_hash = 0; | |
1647 | int match = 0; | |
1648 | ||
1649 | if (all) { | |
1650 | /* | |
1651 | * Only the filter_hash affects all records. | |
1652 | * Update if the record is not in the notrace hash. | |
1653 | */ | |
b848914c | 1654 | if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) |
ed926f9b SR |
1655 | match = 1; |
1656 | } else { | |
06a51d93 SR |
1657 | in_hash = !!ftrace_lookup_ip(hash, rec->ip); |
1658 | in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip); | |
ed926f9b SR |
1659 | |
1660 | /* | |
19eab4a4 SRRH |
1661 | * If filter_hash is set, we want to match all functions |
1662 | * that are in the hash but not in the other hash. | |
ed926f9b | 1663 | * |
19eab4a4 SRRH |
1664 | * If filter_hash is not set, then we are decrementing. |
1665 | * That means we match anything that is in the hash | |
1666 | * and also in the other_hash. That is, we need to turn | |
1667 | * off functions in the other hash because they are disabled | |
1668 | * by this hash. | |
ed926f9b SR |
1669 | */ |
1670 | if (filter_hash && in_hash && !in_other_hash) | |
1671 | match = 1; | |
1672 | else if (!filter_hash && in_hash && | |
06a51d93 | 1673 | (in_other_hash || ftrace_hash_empty(other_hash))) |
ed926f9b SR |
1674 | match = 1; |
1675 | } | |
1676 | if (!match) | |
1677 | continue; | |
1678 | ||
1679 | if (inc) { | |
1680 | rec->flags++; | |
0376bde1 | 1681 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX)) |
ed926f9b | 1682 | return; |
79922b80 SRRH |
1683 | |
1684 | /* | |
1685 | * If there's only a single callback registered to a | |
1686 | * function, and the ops has a trampoline registered | |
1687 | * for it, then we can call it directly. | |
1688 | */ | |
fef5aeee | 1689 | if (ftrace_rec_count(rec) == 1 && ops->trampoline) |
79922b80 | 1690 | rec->flags |= FTRACE_FL_TRAMP; |
fef5aeee | 1691 | else |
79922b80 SRRH |
1692 | /* |
1693 | * If we are adding another function callback | |
1694 | * to this function, and the previous had a | |
bce0b6c5 SRRH |
1695 | * custom trampoline in use, then we need to go |
1696 | * back to the default trampoline. | |
79922b80 | 1697 | */ |
fef5aeee | 1698 | rec->flags &= ~FTRACE_FL_TRAMP; |
79922b80 | 1699 | |
08f6fba5 SR |
1700 | /* |
1701 | * If any ops wants regs saved for this function | |
1702 | * then all ops will get saved regs. | |
1703 | */ | |
1704 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) | |
1705 | rec->flags |= FTRACE_FL_REGS; | |
ed926f9b | 1706 | } else { |
0376bde1 | 1707 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0)) |
ed926f9b SR |
1708 | return; |
1709 | rec->flags--; | |
79922b80 | 1710 | |
4fbb48cb SRRH |
1711 | /* |
1712 | * If the rec had REGS enabled and the ops that is | |
1713 | * being removed had REGS set, then see if there is | |
1714 | * still any ops for this record that wants regs. | |
1715 | * If not, we can stop recording them. | |
1716 | */ | |
0376bde1 | 1717 | if (ftrace_rec_count(rec) > 0 && |
4fbb48cb SRRH |
1718 | rec->flags & FTRACE_FL_REGS && |
1719 | ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1720 | if (!test_rec_ops_needs_regs(rec)) | |
1721 | rec->flags &= ~FTRACE_FL_REGS; | |
1722 | } | |
79922b80 | 1723 | |
fef5aeee SRRH |
1724 | /* |
1725 | * If the rec had TRAMP enabled, then it needs to | |
1726 | * be cleared. As TRAMP can only be enabled iff | |
1727 | * there is only a single ops attached to it. | |
1728 | * In otherwords, always disable it on decrementing. | |
1729 | * In the future, we may set it if rec count is | |
1730 | * decremented to one, and the ops that is left | |
1731 | * has a trampoline. | |
1732 | */ | |
1733 | rec->flags &= ~FTRACE_FL_TRAMP; | |
1734 | ||
79922b80 SRRH |
1735 | /* |
1736 | * flags will be cleared in ftrace_check_record() | |
1737 | * if rec count is zero. | |
1738 | */ | |
ed926f9b SR |
1739 | } |
1740 | count++; | |
1741 | /* Shortcut, if we handled all records, we are done. */ | |
1742 | if (!all && count == hash->count) | |
1743 | return; | |
1744 | } while_for_each_ftrace_rec(); | |
1745 | } | |
1746 | ||
1747 | static void ftrace_hash_rec_disable(struct ftrace_ops *ops, | |
1748 | int filter_hash) | |
1749 | { | |
1750 | __ftrace_hash_rec_update(ops, filter_hash, 0); | |
1751 | } | |
1752 | ||
1753 | static void ftrace_hash_rec_enable(struct ftrace_ops *ops, | |
1754 | int filter_hash) | |
1755 | { | |
1756 | __ftrace_hash_rec_update(ops, filter_hash, 1); | |
1757 | } | |
1758 | ||
84261912 SRRH |
1759 | static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops, |
1760 | int filter_hash, int inc) | |
1761 | { | |
1762 | struct ftrace_ops *op; | |
1763 | ||
1764 | __ftrace_hash_rec_update(ops, filter_hash, inc); | |
1765 | ||
1766 | if (ops->func_hash != &global_ops.local_hash) | |
1767 | return; | |
1768 | ||
1769 | /* | |
1770 | * If the ops shares the global_ops hash, then we need to update | |
1771 | * all ops that are enabled and use this hash. | |
1772 | */ | |
1773 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1774 | /* Already done */ | |
1775 | if (op == ops) | |
1776 | continue; | |
1777 | if (op->func_hash == &global_ops.local_hash) | |
1778 | __ftrace_hash_rec_update(op, filter_hash, inc); | |
1779 | } while_for_each_ftrace_op(op); | |
1780 | } | |
1781 | ||
1782 | static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, | |
1783 | int filter_hash) | |
1784 | { | |
1785 | ftrace_hash_rec_update_modify(ops, filter_hash, 0); | |
1786 | } | |
1787 | ||
1788 | static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, | |
1789 | int filter_hash) | |
1790 | { | |
1791 | ftrace_hash_rec_update_modify(ops, filter_hash, 1); | |
1792 | } | |
1793 | ||
f8b8be8a MH |
1794 | /* |
1795 | * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK | |
1796 | * or no-needed to update, -EBUSY if it detects a conflict of the flag | |
1797 | * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs. | |
1798 | * Note that old_hash and new_hash has below meanings | |
1799 | * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected) | |
1800 | * - If the hash is EMPTY_HASH, it hits nothing | |
1801 | * - Anything else hits the recs which match the hash entries. | |
1802 | */ | |
1803 | static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops, | |
1804 | struct ftrace_hash *old_hash, | |
1805 | struct ftrace_hash *new_hash) | |
1806 | { | |
1807 | struct ftrace_page *pg; | |
1808 | struct dyn_ftrace *rec, *end = NULL; | |
1809 | int in_old, in_new; | |
1810 | ||
1811 | /* Only update if the ops has been registered */ | |
1812 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
1813 | return 0; | |
1814 | ||
1815 | if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY)) | |
1816 | return 0; | |
1817 | ||
1818 | /* | |
1819 | * Since the IPMODIFY is a very address sensitive action, we do not | |
1820 | * allow ftrace_ops to set all functions to new hash. | |
1821 | */ | |
1822 | if (!new_hash || !old_hash) | |
1823 | return -EINVAL; | |
1824 | ||
1825 | /* Update rec->flags */ | |
1826 | do_for_each_ftrace_rec(pg, rec) { | |
1827 | /* We need to update only differences of filter_hash */ | |
1828 | in_old = !!ftrace_lookup_ip(old_hash, rec->ip); | |
1829 | in_new = !!ftrace_lookup_ip(new_hash, rec->ip); | |
1830 | if (in_old == in_new) | |
1831 | continue; | |
1832 | ||
1833 | if (in_new) { | |
1834 | /* New entries must ensure no others are using it */ | |
1835 | if (rec->flags & FTRACE_FL_IPMODIFY) | |
1836 | goto rollback; | |
1837 | rec->flags |= FTRACE_FL_IPMODIFY; | |
1838 | } else /* Removed entry */ | |
1839 | rec->flags &= ~FTRACE_FL_IPMODIFY; | |
1840 | } while_for_each_ftrace_rec(); | |
1841 | ||
1842 | return 0; | |
1843 | ||
1844 | rollback: | |
1845 | end = rec; | |
1846 | ||
1847 | /* Roll back what we did above */ | |
1848 | do_for_each_ftrace_rec(pg, rec) { | |
1849 | if (rec == end) | |
1850 | goto err_out; | |
1851 | ||
1852 | in_old = !!ftrace_lookup_ip(old_hash, rec->ip); | |
1853 | in_new = !!ftrace_lookup_ip(new_hash, rec->ip); | |
1854 | if (in_old == in_new) | |
1855 | continue; | |
1856 | ||
1857 | if (in_new) | |
1858 | rec->flags &= ~FTRACE_FL_IPMODIFY; | |
1859 | else | |
1860 | rec->flags |= FTRACE_FL_IPMODIFY; | |
1861 | } while_for_each_ftrace_rec(); | |
1862 | ||
1863 | err_out: | |
1864 | return -EBUSY; | |
1865 | } | |
1866 | ||
1867 | static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops) | |
1868 | { | |
1869 | struct ftrace_hash *hash = ops->func_hash->filter_hash; | |
1870 | ||
1871 | if (ftrace_hash_empty(hash)) | |
1872 | hash = NULL; | |
1873 | ||
1874 | return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash); | |
1875 | } | |
1876 | ||
1877 | /* Disabling always succeeds */ | |
1878 | static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops) | |
1879 | { | |
1880 | struct ftrace_hash *hash = ops->func_hash->filter_hash; | |
1881 | ||
1882 | if (ftrace_hash_empty(hash)) | |
1883 | hash = NULL; | |
1884 | ||
1885 | __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH); | |
1886 | } | |
1887 | ||
1888 | static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, | |
1889 | struct ftrace_hash *new_hash) | |
1890 | { | |
1891 | struct ftrace_hash *old_hash = ops->func_hash->filter_hash; | |
1892 | ||
1893 | if (ftrace_hash_empty(old_hash)) | |
1894 | old_hash = NULL; | |
1895 | ||
1896 | if (ftrace_hash_empty(new_hash)) | |
1897 | new_hash = NULL; | |
1898 | ||
1899 | return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash); | |
1900 | } | |
1901 | ||
b17e8a37 SR |
1902 | static void print_ip_ins(const char *fmt, unsigned char *p) |
1903 | { | |
1904 | int i; | |
1905 | ||
1906 | printk(KERN_CONT "%s", fmt); | |
1907 | ||
1908 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
1909 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
1910 | } | |
1911 | ||
4fd3279b SRRH |
1912 | static struct ftrace_ops * |
1913 | ftrace_find_tramp_ops_any(struct dyn_ftrace *rec); | |
1914 | ||
c88fd863 SR |
1915 | /** |
1916 | * ftrace_bug - report and shutdown function tracer | |
1917 | * @failed: The failed type (EFAULT, EINVAL, EPERM) | |
4fd3279b | 1918 | * @rec: The record that failed |
c88fd863 SR |
1919 | * |
1920 | * The arch code that enables or disables the function tracing | |
1921 | * can call ftrace_bug() when it has detected a problem in | |
1922 | * modifying the code. @failed should be one of either: | |
1923 | * EFAULT - if the problem happens on reading the @ip address | |
1924 | * EINVAL - if what is read at @ip is not what was expected | |
1925 | * EPERM - if the problem happens on writting to the @ip address | |
1926 | */ | |
4fd3279b | 1927 | void ftrace_bug(int failed, struct dyn_ftrace *rec) |
b17e8a37 | 1928 | { |
4fd3279b SRRH |
1929 | unsigned long ip = rec ? rec->ip : 0; |
1930 | ||
b17e8a37 SR |
1931 | switch (failed) { |
1932 | case -EFAULT: | |
1933 | FTRACE_WARN_ON_ONCE(1); | |
1934 | pr_info("ftrace faulted on modifying "); | |
1935 | print_ip_sym(ip); | |
1936 | break; | |
1937 | case -EINVAL: | |
1938 | FTRACE_WARN_ON_ONCE(1); | |
1939 | pr_info("ftrace failed to modify "); | |
1940 | print_ip_sym(ip); | |
b17e8a37 | 1941 | print_ip_ins(" actual: ", (unsigned char *)ip); |
4fd3279b | 1942 | pr_cont("\n"); |
b17e8a37 SR |
1943 | break; |
1944 | case -EPERM: | |
1945 | FTRACE_WARN_ON_ONCE(1); | |
1946 | pr_info("ftrace faulted on writing "); | |
1947 | print_ip_sym(ip); | |
1948 | break; | |
1949 | default: | |
1950 | FTRACE_WARN_ON_ONCE(1); | |
1951 | pr_info("ftrace faulted on unknown error "); | |
1952 | print_ip_sym(ip); | |
1953 | } | |
4fd3279b SRRH |
1954 | if (rec) { |
1955 | struct ftrace_ops *ops = NULL; | |
1956 | ||
1957 | pr_info("ftrace record flags: %lx\n", rec->flags); | |
1958 | pr_cont(" (%ld)%s", ftrace_rec_count(rec), | |
1959 | rec->flags & FTRACE_FL_REGS ? " R" : " "); | |
1960 | if (rec->flags & FTRACE_FL_TRAMP_EN) { | |
1961 | ops = ftrace_find_tramp_ops_any(rec); | |
1962 | if (ops) | |
1963 | pr_cont("\ttramp: %pS", | |
1964 | (void *)ops->trampoline); | |
1965 | else | |
1966 | pr_cont("\ttramp: ERROR!"); | |
1967 | ||
1968 | } | |
1969 | ip = ftrace_get_addr_curr(rec); | |
1970 | pr_cont(" expected tramp: %lx\n", ip); | |
1971 | } | |
b17e8a37 SR |
1972 | } |
1973 | ||
c88fd863 | 1974 | static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update) |
5072c59f | 1975 | { |
64fbcd16 | 1976 | unsigned long flag = 0UL; |
e7d3737e | 1977 | |
982c350b | 1978 | /* |
30fb6aa7 | 1979 | * If we are updating calls: |
982c350b | 1980 | * |
ed926f9b SR |
1981 | * If the record has a ref count, then we need to enable it |
1982 | * because someone is using it. | |
982c350b | 1983 | * |
ed926f9b SR |
1984 | * Otherwise we make sure its disabled. |
1985 | * | |
30fb6aa7 | 1986 | * If we are disabling calls, then disable all records that |
ed926f9b | 1987 | * are enabled. |
982c350b | 1988 | */ |
0376bde1 | 1989 | if (enable && ftrace_rec_count(rec)) |
ed926f9b | 1990 | flag = FTRACE_FL_ENABLED; |
982c350b | 1991 | |
08f6fba5 | 1992 | /* |
79922b80 SRRH |
1993 | * If enabling and the REGS flag does not match the REGS_EN, or |
1994 | * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore | |
1995 | * this record. Set flags to fail the compare against ENABLED. | |
08f6fba5 | 1996 | */ |
79922b80 SRRH |
1997 | if (flag) { |
1998 | if (!(rec->flags & FTRACE_FL_REGS) != | |
1999 | !(rec->flags & FTRACE_FL_REGS_EN)) | |
2000 | flag |= FTRACE_FL_REGS; | |
2001 | ||
2002 | if (!(rec->flags & FTRACE_FL_TRAMP) != | |
2003 | !(rec->flags & FTRACE_FL_TRAMP_EN)) | |
2004 | flag |= FTRACE_FL_TRAMP; | |
2005 | } | |
08f6fba5 | 2006 | |
64fbcd16 XG |
2007 | /* If the state of this record hasn't changed, then do nothing */ |
2008 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
c88fd863 | 2009 | return FTRACE_UPDATE_IGNORE; |
982c350b | 2010 | |
64fbcd16 | 2011 | if (flag) { |
08f6fba5 SR |
2012 | /* Save off if rec is being enabled (for return value) */ |
2013 | flag ^= rec->flags & FTRACE_FL_ENABLED; | |
2014 | ||
2015 | if (update) { | |
c88fd863 | 2016 | rec->flags |= FTRACE_FL_ENABLED; |
08f6fba5 SR |
2017 | if (flag & FTRACE_FL_REGS) { |
2018 | if (rec->flags & FTRACE_FL_REGS) | |
2019 | rec->flags |= FTRACE_FL_REGS_EN; | |
2020 | else | |
2021 | rec->flags &= ~FTRACE_FL_REGS_EN; | |
2022 | } | |
79922b80 SRRH |
2023 | if (flag & FTRACE_FL_TRAMP) { |
2024 | if (rec->flags & FTRACE_FL_TRAMP) | |
2025 | rec->flags |= FTRACE_FL_TRAMP_EN; | |
2026 | else | |
2027 | rec->flags &= ~FTRACE_FL_TRAMP_EN; | |
2028 | } | |
08f6fba5 SR |
2029 | } |
2030 | ||
2031 | /* | |
2032 | * If this record is being updated from a nop, then | |
2033 | * return UPDATE_MAKE_CALL. | |
08f6fba5 SR |
2034 | * Otherwise, |
2035 | * return UPDATE_MODIFY_CALL to tell the caller to convert | |
f1b2f2bd | 2036 | * from the save regs, to a non-save regs function or |
79922b80 | 2037 | * vice versa, or from a trampoline call. |
08f6fba5 SR |
2038 | */ |
2039 | if (flag & FTRACE_FL_ENABLED) | |
2040 | return FTRACE_UPDATE_MAKE_CALL; | |
f1b2f2bd SRRH |
2041 | |
2042 | return FTRACE_UPDATE_MODIFY_CALL; | |
c88fd863 SR |
2043 | } |
2044 | ||
08f6fba5 SR |
2045 | if (update) { |
2046 | /* If there's no more users, clear all flags */ | |
0376bde1 | 2047 | if (!ftrace_rec_count(rec)) |
08f6fba5 SR |
2048 | rec->flags = 0; |
2049 | else | |
b24d443b SRRH |
2050 | /* |
2051 | * Just disable the record, but keep the ops TRAMP | |
2052 | * and REGS states. The _EN flags must be disabled though. | |
2053 | */ | |
2054 | rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN | | |
2055 | FTRACE_FL_REGS_EN); | |
08f6fba5 | 2056 | } |
c88fd863 SR |
2057 | |
2058 | return FTRACE_UPDATE_MAKE_NOP; | |
2059 | } | |
2060 | ||
2061 | /** | |
2062 | * ftrace_update_record, set a record that now is tracing or not | |
2063 | * @rec: the record to update | |
2064 | * @enable: set to 1 if the record is tracing, zero to force disable | |
2065 | * | |
2066 | * The records that represent all functions that can be traced need | |
2067 | * to be updated when tracing has been enabled. | |
2068 | */ | |
2069 | int ftrace_update_record(struct dyn_ftrace *rec, int enable) | |
2070 | { | |
2071 | return ftrace_check_record(rec, enable, 1); | |
2072 | } | |
2073 | ||
2074 | /** | |
2075 | * ftrace_test_record, check if the record has been enabled or not | |
2076 | * @rec: the record to test | |
2077 | * @enable: set to 1 to check if enabled, 0 if it is disabled | |
2078 | * | |
2079 | * The arch code may need to test if a record is already set to | |
2080 | * tracing to determine how to modify the function code that it | |
2081 | * represents. | |
2082 | */ | |
2083 | int ftrace_test_record(struct dyn_ftrace *rec, int enable) | |
2084 | { | |
2085 | return ftrace_check_record(rec, enable, 0); | |
2086 | } | |
2087 | ||
5fecaa04 SRRH |
2088 | static struct ftrace_ops * |
2089 | ftrace_find_tramp_ops_any(struct dyn_ftrace *rec) | |
2090 | { | |
2091 | struct ftrace_ops *op; | |
fef5aeee | 2092 | unsigned long ip = rec->ip; |
5fecaa04 SRRH |
2093 | |
2094 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2095 | ||
2096 | if (!op->trampoline) | |
2097 | continue; | |
2098 | ||
fef5aeee | 2099 | if (hash_contains_ip(ip, op->func_hash)) |
5fecaa04 SRRH |
2100 | return op; |
2101 | } while_for_each_ftrace_op(op); | |
2102 | ||
2103 | return NULL; | |
2104 | } | |
2105 | ||
79922b80 SRRH |
2106 | static struct ftrace_ops * |
2107 | ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec) | |
2108 | { | |
2109 | struct ftrace_ops *op; | |
fef5aeee | 2110 | unsigned long ip = rec->ip; |
79922b80 | 2111 | |
fef5aeee SRRH |
2112 | /* |
2113 | * Need to check removed ops first. | |
2114 | * If they are being removed, and this rec has a tramp, | |
2115 | * and this rec is in the ops list, then it would be the | |
2116 | * one with the tramp. | |
2117 | */ | |
2118 | if (removed_ops) { | |
2119 | if (hash_contains_ip(ip, &removed_ops->old_hash)) | |
79922b80 SRRH |
2120 | return removed_ops; |
2121 | } | |
2122 | ||
fef5aeee SRRH |
2123 | /* |
2124 | * Need to find the current trampoline for a rec. | |
2125 | * Now, a trampoline is only attached to a rec if there | |
2126 | * was a single 'ops' attached to it. But this can be called | |
2127 | * when we are adding another op to the rec or removing the | |
2128 | * current one. Thus, if the op is being added, we can | |
2129 | * ignore it because it hasn't attached itself to the rec | |
4fc40904 SRRH |
2130 | * yet. |
2131 | * | |
2132 | * If an ops is being modified (hooking to different functions) | |
2133 | * then we don't care about the new functions that are being | |
2134 | * added, just the old ones (that are probably being removed). | |
2135 | * | |
2136 | * If we are adding an ops to a function that already is using | |
2137 | * a trampoline, it needs to be removed (trampolines are only | |
2138 | * for single ops connected), then an ops that is not being | |
2139 | * modified also needs to be checked. | |
fef5aeee | 2140 | */ |
79922b80 | 2141 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
fef5aeee SRRH |
2142 | |
2143 | if (!op->trampoline) | |
2144 | continue; | |
2145 | ||
2146 | /* | |
2147 | * If the ops is being added, it hasn't gotten to | |
2148 | * the point to be removed from this tree yet. | |
2149 | */ | |
2150 | if (op->flags & FTRACE_OPS_FL_ADDING) | |
79922b80 SRRH |
2151 | continue; |
2152 | ||
4fc40904 | 2153 | |
fef5aeee | 2154 | /* |
4fc40904 SRRH |
2155 | * If the ops is being modified and is in the old |
2156 | * hash, then it is probably being removed from this | |
2157 | * function. | |
fef5aeee | 2158 | */ |
fef5aeee SRRH |
2159 | if ((op->flags & FTRACE_OPS_FL_MODIFYING) && |
2160 | hash_contains_ip(ip, &op->old_hash)) | |
79922b80 | 2161 | return op; |
4fc40904 SRRH |
2162 | /* |
2163 | * If the ops is not being added or modified, and it's | |
2164 | * in its normal filter hash, then this must be the one | |
2165 | * we want! | |
2166 | */ | |
2167 | if (!(op->flags & FTRACE_OPS_FL_MODIFYING) && | |
2168 | hash_contains_ip(ip, op->func_hash)) | |
2169 | return op; | |
79922b80 SRRH |
2170 | |
2171 | } while_for_each_ftrace_op(op); | |
2172 | ||
2173 | return NULL; | |
2174 | } | |
2175 | ||
2176 | static struct ftrace_ops * | |
2177 | ftrace_find_tramp_ops_new(struct dyn_ftrace *rec) | |
2178 | { | |
2179 | struct ftrace_ops *op; | |
fef5aeee | 2180 | unsigned long ip = rec->ip; |
79922b80 SRRH |
2181 | |
2182 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2183 | /* pass rec in as regs to have non-NULL val */ | |
fef5aeee | 2184 | if (hash_contains_ip(ip, op->func_hash)) |
79922b80 SRRH |
2185 | return op; |
2186 | } while_for_each_ftrace_op(op); | |
2187 | ||
2188 | return NULL; | |
2189 | } | |
2190 | ||
7413af1f SRRH |
2191 | /** |
2192 | * ftrace_get_addr_new - Get the call address to set to | |
2193 | * @rec: The ftrace record descriptor | |
2194 | * | |
2195 | * If the record has the FTRACE_FL_REGS set, that means that it | |
2196 | * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS | |
2197 | * is not not set, then it wants to convert to the normal callback. | |
2198 | * | |
2199 | * Returns the address of the trampoline to set to | |
2200 | */ | |
2201 | unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec) | |
2202 | { | |
79922b80 SRRH |
2203 | struct ftrace_ops *ops; |
2204 | ||
2205 | /* Trampolines take precedence over regs */ | |
2206 | if (rec->flags & FTRACE_FL_TRAMP) { | |
2207 | ops = ftrace_find_tramp_ops_new(rec); | |
2208 | if (FTRACE_WARN_ON(!ops || !ops->trampoline)) { | |
bce0b6c5 SRRH |
2209 | pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n", |
2210 | (void *)rec->ip, (void *)rec->ip, rec->flags); | |
79922b80 SRRH |
2211 | /* Ftrace is shutting down, return anything */ |
2212 | return (unsigned long)FTRACE_ADDR; | |
2213 | } | |
2214 | return ops->trampoline; | |
2215 | } | |
2216 | ||
7413af1f SRRH |
2217 | if (rec->flags & FTRACE_FL_REGS) |
2218 | return (unsigned long)FTRACE_REGS_ADDR; | |
2219 | else | |
2220 | return (unsigned long)FTRACE_ADDR; | |
2221 | } | |
2222 | ||
2223 | /** | |
2224 | * ftrace_get_addr_curr - Get the call address that is already there | |
2225 | * @rec: The ftrace record descriptor | |
2226 | * | |
2227 | * The FTRACE_FL_REGS_EN is set when the record already points to | |
2228 | * a function that saves all the regs. Basically the '_EN' version | |
2229 | * represents the current state of the function. | |
2230 | * | |
2231 | * Returns the address of the trampoline that is currently being called | |
2232 | */ | |
2233 | unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec) | |
2234 | { | |
79922b80 SRRH |
2235 | struct ftrace_ops *ops; |
2236 | ||
2237 | /* Trampolines take precedence over regs */ | |
2238 | if (rec->flags & FTRACE_FL_TRAMP_EN) { | |
2239 | ops = ftrace_find_tramp_ops_curr(rec); | |
2240 | if (FTRACE_WARN_ON(!ops)) { | |
2241 | pr_warning("Bad trampoline accounting at: %p (%pS)\n", | |
2242 | (void *)rec->ip, (void *)rec->ip); | |
2243 | /* Ftrace is shutting down, return anything */ | |
2244 | return (unsigned long)FTRACE_ADDR; | |
2245 | } | |
2246 | return ops->trampoline; | |
2247 | } | |
2248 | ||
7413af1f SRRH |
2249 | if (rec->flags & FTRACE_FL_REGS_EN) |
2250 | return (unsigned long)FTRACE_REGS_ADDR; | |
2251 | else | |
2252 | return (unsigned long)FTRACE_ADDR; | |
2253 | } | |
2254 | ||
c88fd863 SR |
2255 | static int |
2256 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) | |
2257 | { | |
08f6fba5 | 2258 | unsigned long ftrace_old_addr; |
c88fd863 SR |
2259 | unsigned long ftrace_addr; |
2260 | int ret; | |
2261 | ||
7c0868e0 | 2262 | ftrace_addr = ftrace_get_addr_new(rec); |
c88fd863 | 2263 | |
7c0868e0 SRRH |
2264 | /* This needs to be done before we call ftrace_update_record */ |
2265 | ftrace_old_addr = ftrace_get_addr_curr(rec); | |
2266 | ||
2267 | ret = ftrace_update_record(rec, enable); | |
08f6fba5 | 2268 | |
c88fd863 SR |
2269 | switch (ret) { |
2270 | case FTRACE_UPDATE_IGNORE: | |
2271 | return 0; | |
2272 | ||
2273 | case FTRACE_UPDATE_MAKE_CALL: | |
64fbcd16 | 2274 | return ftrace_make_call(rec, ftrace_addr); |
c88fd863 SR |
2275 | |
2276 | case FTRACE_UPDATE_MAKE_NOP: | |
39b5552c | 2277 | return ftrace_make_nop(NULL, rec, ftrace_old_addr); |
08f6fba5 | 2278 | |
08f6fba5 | 2279 | case FTRACE_UPDATE_MODIFY_CALL: |
08f6fba5 | 2280 | return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr); |
5072c59f SR |
2281 | } |
2282 | ||
c88fd863 | 2283 | return -1; /* unknow ftrace bug */ |
5072c59f SR |
2284 | } |
2285 | ||
e4f5d544 | 2286 | void __weak ftrace_replace_code(int enable) |
3c1720f0 | 2287 | { |
3c1720f0 SR |
2288 | struct dyn_ftrace *rec; |
2289 | struct ftrace_page *pg; | |
6a24a244 | 2290 | int failed; |
3c1720f0 | 2291 | |
45a4a237 SR |
2292 | if (unlikely(ftrace_disabled)) |
2293 | return; | |
2294 | ||
265c831c | 2295 | do_for_each_ftrace_rec(pg, rec) { |
e4f5d544 | 2296 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 2297 | if (failed) { |
4fd3279b | 2298 | ftrace_bug(failed, rec); |
3279ba37 SR |
2299 | /* Stop processing */ |
2300 | return; | |
3c1720f0 | 2301 | } |
265c831c | 2302 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
2303 | } |
2304 | ||
c88fd863 SR |
2305 | struct ftrace_rec_iter { |
2306 | struct ftrace_page *pg; | |
2307 | int index; | |
2308 | }; | |
2309 | ||
2310 | /** | |
2311 | * ftrace_rec_iter_start, start up iterating over traced functions | |
2312 | * | |
2313 | * Returns an iterator handle that is used to iterate over all | |
2314 | * the records that represent address locations where functions | |
2315 | * are traced. | |
2316 | * | |
2317 | * May return NULL if no records are available. | |
2318 | */ | |
2319 | struct ftrace_rec_iter *ftrace_rec_iter_start(void) | |
2320 | { | |
2321 | /* | |
2322 | * We only use a single iterator. | |
2323 | * Protected by the ftrace_lock mutex. | |
2324 | */ | |
2325 | static struct ftrace_rec_iter ftrace_rec_iter; | |
2326 | struct ftrace_rec_iter *iter = &ftrace_rec_iter; | |
2327 | ||
2328 | iter->pg = ftrace_pages_start; | |
2329 | iter->index = 0; | |
2330 | ||
2331 | /* Could have empty pages */ | |
2332 | while (iter->pg && !iter->pg->index) | |
2333 | iter->pg = iter->pg->next; | |
2334 | ||
2335 | if (!iter->pg) | |
2336 | return NULL; | |
2337 | ||
2338 | return iter; | |
2339 | } | |
2340 | ||
2341 | /** | |
2342 | * ftrace_rec_iter_next, get the next record to process. | |
2343 | * @iter: The handle to the iterator. | |
2344 | * | |
2345 | * Returns the next iterator after the given iterator @iter. | |
2346 | */ | |
2347 | struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) | |
2348 | { | |
2349 | iter->index++; | |
2350 | ||
2351 | if (iter->index >= iter->pg->index) { | |
2352 | iter->pg = iter->pg->next; | |
2353 | iter->index = 0; | |
2354 | ||
2355 | /* Could have empty pages */ | |
2356 | while (iter->pg && !iter->pg->index) | |
2357 | iter->pg = iter->pg->next; | |
2358 | } | |
2359 | ||
2360 | if (!iter->pg) | |
2361 | return NULL; | |
2362 | ||
2363 | return iter; | |
2364 | } | |
2365 | ||
2366 | /** | |
2367 | * ftrace_rec_iter_record, get the record at the iterator location | |
2368 | * @iter: The current iterator location | |
2369 | * | |
2370 | * Returns the record that the current @iter is at. | |
2371 | */ | |
2372 | struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) | |
2373 | { | |
2374 | return &iter->pg->records[iter->index]; | |
2375 | } | |
2376 | ||
492a7ea5 | 2377 | static int |
31e88909 | 2378 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 | 2379 | { |
593eb8a2 | 2380 | int ret; |
3c1720f0 | 2381 | |
45a4a237 SR |
2382 | if (unlikely(ftrace_disabled)) |
2383 | return 0; | |
2384 | ||
25aac9dc | 2385 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 2386 | if (ret) { |
4fd3279b | 2387 | ftrace_bug(ret, rec); |
492a7ea5 | 2388 | return 0; |
37ad5084 | 2389 | } |
492a7ea5 | 2390 | return 1; |
3c1720f0 SR |
2391 | } |
2392 | ||
000ab691 SR |
2393 | /* |
2394 | * archs can override this function if they must do something | |
2395 | * before the modifying code is performed. | |
2396 | */ | |
2397 | int __weak ftrace_arch_code_modify_prepare(void) | |
2398 | { | |
2399 | return 0; | |
2400 | } | |
2401 | ||
2402 | /* | |
2403 | * archs can override this function if they must do something | |
2404 | * after the modifying code is performed. | |
2405 | */ | |
2406 | int __weak ftrace_arch_code_modify_post_process(void) | |
2407 | { | |
2408 | return 0; | |
2409 | } | |
2410 | ||
8ed3e2cf | 2411 | void ftrace_modify_all_code(int command) |
3d083395 | 2412 | { |
59338f75 | 2413 | int update = command & FTRACE_UPDATE_TRACE_FUNC; |
cd21067f | 2414 | int err = 0; |
59338f75 SRRH |
2415 | |
2416 | /* | |
2417 | * If the ftrace_caller calls a ftrace_ops func directly, | |
2418 | * we need to make sure that it only traces functions it | |
2419 | * expects to trace. When doing the switch of functions, | |
2420 | * we need to update to the ftrace_ops_list_func first | |
2421 | * before the transition between old and new calls are set, | |
2422 | * as the ftrace_ops_list_func will check the ops hashes | |
2423 | * to make sure the ops are having the right functions | |
2424 | * traced. | |
2425 | */ | |
cd21067f PM |
2426 | if (update) { |
2427 | err = ftrace_update_ftrace_func(ftrace_ops_list_func); | |
2428 | if (FTRACE_WARN_ON(err)) | |
2429 | return; | |
2430 | } | |
59338f75 | 2431 | |
8ed3e2cf | 2432 | if (command & FTRACE_UPDATE_CALLS) |
d61f82d0 | 2433 | ftrace_replace_code(1); |
8ed3e2cf | 2434 | else if (command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
2435 | ftrace_replace_code(0); |
2436 | ||
405e1d83 SRRH |
2437 | if (update && ftrace_trace_function != ftrace_ops_list_func) { |
2438 | function_trace_op = set_function_trace_op; | |
2439 | smp_wmb(); | |
2440 | /* If irqs are disabled, we are in stop machine */ | |
2441 | if (!irqs_disabled()) | |
2442 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
cd21067f PM |
2443 | err = ftrace_update_ftrace_func(ftrace_trace_function); |
2444 | if (FTRACE_WARN_ON(err)) | |
2445 | return; | |
405e1d83 | 2446 | } |
d61f82d0 | 2447 | |
8ed3e2cf | 2448 | if (command & FTRACE_START_FUNC_RET) |
cd21067f | 2449 | err = ftrace_enable_ftrace_graph_caller(); |
8ed3e2cf | 2450 | else if (command & FTRACE_STOP_FUNC_RET) |
cd21067f PM |
2451 | err = ftrace_disable_ftrace_graph_caller(); |
2452 | FTRACE_WARN_ON(err); | |
8ed3e2cf SR |
2453 | } |
2454 | ||
2455 | static int __ftrace_modify_code(void *data) | |
2456 | { | |
2457 | int *command = data; | |
2458 | ||
2459 | ftrace_modify_all_code(*command); | |
5a45cfe1 | 2460 | |
d61f82d0 | 2461 | return 0; |
3d083395 SR |
2462 | } |
2463 | ||
c88fd863 SR |
2464 | /** |
2465 | * ftrace_run_stop_machine, go back to the stop machine method | |
2466 | * @command: The command to tell ftrace what to do | |
2467 | * | |
2468 | * If an arch needs to fall back to the stop machine method, the | |
2469 | * it can call this function. | |
2470 | */ | |
2471 | void ftrace_run_stop_machine(int command) | |
2472 | { | |
2473 | stop_machine(__ftrace_modify_code, &command, NULL); | |
2474 | } | |
2475 | ||
2476 | /** | |
2477 | * arch_ftrace_update_code, modify the code to trace or not trace | |
2478 | * @command: The command that needs to be done | |
2479 | * | |
2480 | * Archs can override this function if it does not need to | |
2481 | * run stop_machine() to modify code. | |
2482 | */ | |
2483 | void __weak arch_ftrace_update_code(int command) | |
2484 | { | |
2485 | ftrace_run_stop_machine(command); | |
2486 | } | |
2487 | ||
e309b41d | 2488 | static void ftrace_run_update_code(int command) |
3d083395 | 2489 | { |
000ab691 SR |
2490 | int ret; |
2491 | ||
2492 | ret = ftrace_arch_code_modify_prepare(); | |
2493 | FTRACE_WARN_ON(ret); | |
2494 | if (ret) | |
2495 | return; | |
2496 | ||
c88fd863 SR |
2497 | /* |
2498 | * By default we use stop_machine() to modify the code. | |
2499 | * But archs can do what ever they want as long as it | |
2500 | * is safe. The stop_machine() is the safest, but also | |
2501 | * produces the most overhead. | |
2502 | */ | |
2503 | arch_ftrace_update_code(command); | |
2504 | ||
000ab691 SR |
2505 | ret = ftrace_arch_code_modify_post_process(); |
2506 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
2507 | } |
2508 | ||
8252ecf3 | 2509 | static void ftrace_run_modify_code(struct ftrace_ops *ops, int command, |
7485058e | 2510 | struct ftrace_ops_hash *old_hash) |
e1effa01 SRRH |
2511 | { |
2512 | ops->flags |= FTRACE_OPS_FL_MODIFYING; | |
7485058e SRRH |
2513 | ops->old_hash.filter_hash = old_hash->filter_hash; |
2514 | ops->old_hash.notrace_hash = old_hash->notrace_hash; | |
e1effa01 | 2515 | ftrace_run_update_code(command); |
8252ecf3 | 2516 | ops->old_hash.filter_hash = NULL; |
7485058e | 2517 | ops->old_hash.notrace_hash = NULL; |
e1effa01 SRRH |
2518 | ops->flags &= ~FTRACE_OPS_FL_MODIFYING; |
2519 | } | |
2520 | ||
d61f82d0 | 2521 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 2522 | static int ftrace_start_up; |
df4fc315 | 2523 | |
12cce594 SRRH |
2524 | void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops) |
2525 | { | |
2526 | } | |
2527 | ||
db0fbadc JS |
2528 | static void control_ops_free(struct ftrace_ops *ops) |
2529 | { | |
2530 | free_percpu(ops->disabled); | |
2531 | } | |
2532 | ||
df4fc315 SR |
2533 | static void ftrace_startup_enable(int command) |
2534 | { | |
2535 | if (saved_ftrace_func != ftrace_trace_function) { | |
2536 | saved_ftrace_func = ftrace_trace_function; | |
2537 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2538 | } | |
2539 | ||
2540 | if (!command || !ftrace_enabled) | |
2541 | return; | |
2542 | ||
2543 | ftrace_run_update_code(command); | |
2544 | } | |
d61f82d0 | 2545 | |
e1effa01 SRRH |
2546 | static void ftrace_startup_all(int command) |
2547 | { | |
2548 | update_all_ops = true; | |
2549 | ftrace_startup_enable(command); | |
2550 | update_all_ops = false; | |
2551 | } | |
2552 | ||
a1cd6173 | 2553 | static int ftrace_startup(struct ftrace_ops *ops, int command) |
3d083395 | 2554 | { |
8a56d776 | 2555 | int ret; |
b848914c | 2556 | |
4eebcc81 | 2557 | if (unlikely(ftrace_disabled)) |
a1cd6173 | 2558 | return -ENODEV; |
4eebcc81 | 2559 | |
8a56d776 SRRH |
2560 | ret = __register_ftrace_function(ops); |
2561 | if (ret) | |
2562 | return ret; | |
2563 | ||
60a7ecf4 | 2564 | ftrace_start_up++; |
30fb6aa7 | 2565 | command |= FTRACE_UPDATE_CALLS; |
d61f82d0 | 2566 | |
e1effa01 SRRH |
2567 | /* |
2568 | * Note that ftrace probes uses this to start up | |
2569 | * and modify functions it will probe. But we still | |
2570 | * set the ADDING flag for modification, as probes | |
2571 | * do not have trampolines. If they add them in the | |
2572 | * future, then the probes will need to distinguish | |
2573 | * between adding and updating probes. | |
2574 | */ | |
2575 | ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING; | |
66209a5b | 2576 | |
f8b8be8a MH |
2577 | ret = ftrace_hash_ipmodify_enable(ops); |
2578 | if (ret < 0) { | |
2579 | /* Rollback registration process */ | |
2580 | __unregister_ftrace_function(ops); | |
2581 | ftrace_start_up--; | |
2582 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; | |
2583 | return ret; | |
2584 | } | |
2585 | ||
66209a5b | 2586 | ftrace_hash_rec_enable(ops, 1); |
ed926f9b | 2587 | |
df4fc315 | 2588 | ftrace_startup_enable(command); |
a1cd6173 | 2589 | |
e1effa01 SRRH |
2590 | ops->flags &= ~FTRACE_OPS_FL_ADDING; |
2591 | ||
a1cd6173 | 2592 | return 0; |
3d083395 SR |
2593 | } |
2594 | ||
8a56d776 | 2595 | static int ftrace_shutdown(struct ftrace_ops *ops, int command) |
3d083395 | 2596 | { |
8a56d776 | 2597 | int ret; |
b848914c | 2598 | |
4eebcc81 | 2599 | if (unlikely(ftrace_disabled)) |
8a56d776 SRRH |
2600 | return -ENODEV; |
2601 | ||
2602 | ret = __unregister_ftrace_function(ops); | |
2603 | if (ret) | |
2604 | return ret; | |
4eebcc81 | 2605 | |
60a7ecf4 | 2606 | ftrace_start_up--; |
9ea1a153 FW |
2607 | /* |
2608 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
2609 | * critical but the ftrace_call callers may be never nopped again after | |
2610 | * further ftrace uses. | |
2611 | */ | |
2612 | WARN_ON_ONCE(ftrace_start_up < 0); | |
2613 | ||
f8b8be8a MH |
2614 | /* Disabling ipmodify never fails */ |
2615 | ftrace_hash_ipmodify_disable(ops); | |
66209a5b | 2616 | ftrace_hash_rec_disable(ops, 1); |
ed926f9b | 2617 | |
a737e6dd | 2618 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
b848914c | 2619 | |
30fb6aa7 | 2620 | command |= FTRACE_UPDATE_CALLS; |
3d083395 | 2621 | |
d61f82d0 SR |
2622 | if (saved_ftrace_func != ftrace_trace_function) { |
2623 | saved_ftrace_func = ftrace_trace_function; | |
2624 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2625 | } | |
3d083395 | 2626 | |
a4c35ed2 SRRH |
2627 | if (!command || !ftrace_enabled) { |
2628 | /* | |
2629 | * If these are control ops, they still need their | |
2630 | * per_cpu field freed. Since, function tracing is | |
2631 | * not currently active, we can just free them | |
2632 | * without synchronizing all CPUs. | |
2633 | */ | |
2634 | if (ops->flags & FTRACE_OPS_FL_CONTROL) | |
2635 | control_ops_free(ops); | |
8a56d776 | 2636 | return 0; |
a4c35ed2 | 2637 | } |
d61f82d0 | 2638 | |
79922b80 SRRH |
2639 | /* |
2640 | * If the ops uses a trampoline, then it needs to be | |
2641 | * tested first on update. | |
2642 | */ | |
e1effa01 | 2643 | ops->flags |= FTRACE_OPS_FL_REMOVING; |
79922b80 SRRH |
2644 | removed_ops = ops; |
2645 | ||
fef5aeee SRRH |
2646 | /* The trampoline logic checks the old hashes */ |
2647 | ops->old_hash.filter_hash = ops->func_hash->filter_hash; | |
2648 | ops->old_hash.notrace_hash = ops->func_hash->notrace_hash; | |
2649 | ||
d61f82d0 | 2650 | ftrace_run_update_code(command); |
a4c35ed2 | 2651 | |
84bde62c SRRH |
2652 | /* |
2653 | * If there's no more ops registered with ftrace, run a | |
2654 | * sanity check to make sure all rec flags are cleared. | |
2655 | */ | |
2656 | if (ftrace_ops_list == &ftrace_list_end) { | |
2657 | struct ftrace_page *pg; | |
2658 | struct dyn_ftrace *rec; | |
2659 | ||
2660 | do_for_each_ftrace_rec(pg, rec) { | |
2661 | if (FTRACE_WARN_ON_ONCE(rec->flags)) | |
2662 | pr_warn(" %pS flags:%lx\n", | |
2663 | (void *)rec->ip, rec->flags); | |
2664 | } while_for_each_ftrace_rec(); | |
2665 | } | |
2666 | ||
fef5aeee SRRH |
2667 | ops->old_hash.filter_hash = NULL; |
2668 | ops->old_hash.notrace_hash = NULL; | |
2669 | ||
2670 | removed_ops = NULL; | |
e1effa01 | 2671 | ops->flags &= ~FTRACE_OPS_FL_REMOVING; |
79922b80 | 2672 | |
a4c35ed2 SRRH |
2673 | /* |
2674 | * Dynamic ops may be freed, we must make sure that all | |
2675 | * callers are done before leaving this function. | |
2676 | * The same goes for freeing the per_cpu data of the control | |
2677 | * ops. | |
2678 | * | |
2679 | * Again, normal synchronize_sched() is not good enough. | |
2680 | * We need to do a hard force of sched synchronization. | |
2681 | * This is because we use preempt_disable() to do RCU, but | |
2682 | * the function tracers can be called where RCU is not watching | |
2683 | * (like before user_exit()). We can not rely on the RCU | |
2684 | * infrastructure to do the synchronization, thus we must do it | |
2685 | * ourselves. | |
2686 | */ | |
2687 | if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_CONTROL)) { | |
2688 | schedule_on_each_cpu(ftrace_sync); | |
2689 | ||
12cce594 SRRH |
2690 | arch_ftrace_trampoline_free(ops); |
2691 | ||
a4c35ed2 SRRH |
2692 | if (ops->flags & FTRACE_OPS_FL_CONTROL) |
2693 | control_ops_free(ops); | |
2694 | } | |
2695 | ||
8a56d776 | 2696 | return 0; |
3d083395 SR |
2697 | } |
2698 | ||
e309b41d | 2699 | static void ftrace_startup_sysctl(void) |
b0fc494f | 2700 | { |
1619dc3f PA |
2701 | int command; |
2702 | ||
4eebcc81 SR |
2703 | if (unlikely(ftrace_disabled)) |
2704 | return; | |
2705 | ||
d61f82d0 SR |
2706 | /* Force update next time */ |
2707 | saved_ftrace_func = NULL; | |
60a7ecf4 | 2708 | /* ftrace_start_up is true if we want ftrace running */ |
1619dc3f PA |
2709 | if (ftrace_start_up) { |
2710 | command = FTRACE_UPDATE_CALLS; | |
2711 | if (ftrace_graph_active) | |
2712 | command |= FTRACE_START_FUNC_RET; | |
2713 | ftrace_run_update_code(command); | |
2714 | } | |
b0fc494f SR |
2715 | } |
2716 | ||
e309b41d | 2717 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 2718 | { |
1619dc3f PA |
2719 | int command; |
2720 | ||
4eebcc81 SR |
2721 | if (unlikely(ftrace_disabled)) |
2722 | return; | |
2723 | ||
60a7ecf4 | 2724 | /* ftrace_start_up is true if ftrace is running */ |
1619dc3f PA |
2725 | if (ftrace_start_up) { |
2726 | command = FTRACE_DISABLE_CALLS; | |
2727 | if (ftrace_graph_active) | |
2728 | command |= FTRACE_STOP_FUNC_RET; | |
2729 | ftrace_run_update_code(command); | |
2730 | } | |
b0fc494f SR |
2731 | } |
2732 | ||
3d083395 | 2733 | static cycle_t ftrace_update_time; |
3d083395 SR |
2734 | unsigned long ftrace_update_tot_cnt; |
2735 | ||
8c4f3c3f | 2736 | static inline int ops_traces_mod(struct ftrace_ops *ops) |
f7bc8b61 | 2737 | { |
8c4f3c3f SRRH |
2738 | /* |
2739 | * Filter_hash being empty will default to trace module. | |
2740 | * But notrace hash requires a test of individual module functions. | |
2741 | */ | |
33b7f99c SRRH |
2742 | return ftrace_hash_empty(ops->func_hash->filter_hash) && |
2743 | ftrace_hash_empty(ops->func_hash->notrace_hash); | |
8c4f3c3f SRRH |
2744 | } |
2745 | ||
2746 | /* | |
2747 | * Check if the current ops references the record. | |
2748 | * | |
2749 | * If the ops traces all functions, then it was already accounted for. | |
2750 | * If the ops does not trace the current record function, skip it. | |
2751 | * If the ops ignores the function via notrace filter, skip it. | |
2752 | */ | |
2753 | static inline bool | |
2754 | ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec) | |
2755 | { | |
2756 | /* If ops isn't enabled, ignore it */ | |
2757 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
2758 | return 0; | |
2759 | ||
2760 | /* If ops traces all mods, we already accounted for it */ | |
2761 | if (ops_traces_mod(ops)) | |
2762 | return 0; | |
2763 | ||
2764 | /* The function must be in the filter */ | |
33b7f99c SRRH |
2765 | if (!ftrace_hash_empty(ops->func_hash->filter_hash) && |
2766 | !ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip)) | |
8c4f3c3f | 2767 | return 0; |
f7bc8b61 | 2768 | |
8c4f3c3f | 2769 | /* If in notrace hash, we ignore it too */ |
33b7f99c | 2770 | if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip)) |
8c4f3c3f SRRH |
2771 | return 0; |
2772 | ||
2773 | return 1; | |
2774 | } | |
2775 | ||
2776 | static int referenced_filters(struct dyn_ftrace *rec) | |
2777 | { | |
2778 | struct ftrace_ops *ops; | |
2779 | int cnt = 0; | |
2780 | ||
2781 | for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) { | |
2782 | if (ops_references_rec(ops, rec)) | |
2783 | cnt++; | |
2784 | } | |
2785 | ||
2786 | return cnt; | |
f7bc8b61 SR |
2787 | } |
2788 | ||
1dc43cf0 | 2789 | static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs) |
3d083395 | 2790 | { |
85ae32ae | 2791 | struct ftrace_page *pg; |
e94142a6 | 2792 | struct dyn_ftrace *p; |
f22f9a89 | 2793 | cycle_t start, stop; |
1dc43cf0 | 2794 | unsigned long update_cnt = 0; |
f7bc8b61 | 2795 | unsigned long ref = 0; |
8c4f3c3f | 2796 | bool test = false; |
85ae32ae | 2797 | int i; |
f7bc8b61 SR |
2798 | |
2799 | /* | |
2800 | * When adding a module, we need to check if tracers are | |
2801 | * currently enabled and if they are set to trace all functions. | |
2802 | * If they are, we need to enable the module functions as well | |
2803 | * as update the reference counts for those function records. | |
2804 | */ | |
2805 | if (mod) { | |
2806 | struct ftrace_ops *ops; | |
2807 | ||
2808 | for (ops = ftrace_ops_list; | |
2809 | ops != &ftrace_list_end; ops = ops->next) { | |
8c4f3c3f SRRH |
2810 | if (ops->flags & FTRACE_OPS_FL_ENABLED) { |
2811 | if (ops_traces_mod(ops)) | |
2812 | ref++; | |
2813 | else | |
2814 | test = true; | |
2815 | } | |
f7bc8b61 SR |
2816 | } |
2817 | } | |
3d083395 | 2818 | |
750ed1a4 | 2819 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 | 2820 | |
1dc43cf0 | 2821 | for (pg = new_pgs; pg; pg = pg->next) { |
3d083395 | 2822 | |
85ae32ae | 2823 | for (i = 0; i < pg->index; i++) { |
8c4f3c3f SRRH |
2824 | int cnt = ref; |
2825 | ||
85ae32ae SR |
2826 | /* If something went wrong, bail without enabling anything */ |
2827 | if (unlikely(ftrace_disabled)) | |
2828 | return -1; | |
f22f9a89 | 2829 | |
85ae32ae | 2830 | p = &pg->records[i]; |
8c4f3c3f SRRH |
2831 | if (test) |
2832 | cnt += referenced_filters(p); | |
2833 | p->flags = cnt; | |
f22f9a89 | 2834 | |
85ae32ae SR |
2835 | /* |
2836 | * Do the initial record conversion from mcount jump | |
2837 | * to the NOP instructions. | |
2838 | */ | |
2839 | if (!ftrace_code_disable(mod, p)) | |
2840 | break; | |
5cb084bb | 2841 | |
1dc43cf0 | 2842 | update_cnt++; |
5cb084bb | 2843 | |
85ae32ae SR |
2844 | /* |
2845 | * If the tracing is enabled, go ahead and enable the record. | |
2846 | * | |
2847 | * The reason not to enable the record immediatelly is the | |
2848 | * inherent check of ftrace_make_nop/ftrace_make_call for | |
2849 | * correct previous instructions. Making first the NOP | |
2850 | * conversion puts the module to the correct state, thus | |
2851 | * passing the ftrace_make_call check. | |
2852 | */ | |
8c4f3c3f | 2853 | if (ftrace_start_up && cnt) { |
85ae32ae SR |
2854 | int failed = __ftrace_replace_code(p, 1); |
2855 | if (failed) | |
4fd3279b | 2856 | ftrace_bug(failed, p); |
85ae32ae | 2857 | } |
5cb084bb | 2858 | } |
3d083395 SR |
2859 | } |
2860 | ||
750ed1a4 | 2861 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 | 2862 | ftrace_update_time = stop - start; |
1dc43cf0 | 2863 | ftrace_update_tot_cnt += update_cnt; |
3d083395 | 2864 | |
16444a8a ACM |
2865 | return 0; |
2866 | } | |
2867 | ||
a7900875 | 2868 | static int ftrace_allocate_records(struct ftrace_page *pg, int count) |
3c1720f0 | 2869 | { |
a7900875 | 2870 | int order; |
3c1720f0 | 2871 | int cnt; |
3c1720f0 | 2872 | |
a7900875 SR |
2873 | if (WARN_ON(!count)) |
2874 | return -EINVAL; | |
2875 | ||
2876 | order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE)); | |
3c1720f0 SR |
2877 | |
2878 | /* | |
a7900875 SR |
2879 | * We want to fill as much as possible. No more than a page |
2880 | * may be empty. | |
3c1720f0 | 2881 | */ |
a7900875 SR |
2882 | while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE) |
2883 | order--; | |
3c1720f0 | 2884 | |
a7900875 SR |
2885 | again: |
2886 | pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order); | |
3c1720f0 | 2887 | |
a7900875 SR |
2888 | if (!pg->records) { |
2889 | /* if we can't allocate this size, try something smaller */ | |
2890 | if (!order) | |
2891 | return -ENOMEM; | |
2892 | order >>= 1; | |
2893 | goto again; | |
2894 | } | |
3c1720f0 | 2895 | |
a7900875 SR |
2896 | cnt = (PAGE_SIZE << order) / ENTRY_SIZE; |
2897 | pg->size = cnt; | |
3c1720f0 | 2898 | |
a7900875 SR |
2899 | if (cnt > count) |
2900 | cnt = count; | |
2901 | ||
2902 | return cnt; | |
2903 | } | |
2904 | ||
2905 | static struct ftrace_page * | |
2906 | ftrace_allocate_pages(unsigned long num_to_init) | |
2907 | { | |
2908 | struct ftrace_page *start_pg; | |
2909 | struct ftrace_page *pg; | |
2910 | int order; | |
2911 | int cnt; | |
2912 | ||
2913 | if (!num_to_init) | |
2914 | return 0; | |
2915 | ||
2916 | start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL); | |
2917 | if (!pg) | |
2918 | return NULL; | |
2919 | ||
2920 | /* | |
2921 | * Try to allocate as much as possible in one continues | |
2922 | * location that fills in all of the space. We want to | |
2923 | * waste as little space as possible. | |
2924 | */ | |
2925 | for (;;) { | |
2926 | cnt = ftrace_allocate_records(pg, num_to_init); | |
2927 | if (cnt < 0) | |
2928 | goto free_pages; | |
2929 | ||
2930 | num_to_init -= cnt; | |
2931 | if (!num_to_init) | |
3c1720f0 SR |
2932 | break; |
2933 | ||
a7900875 SR |
2934 | pg->next = kzalloc(sizeof(*pg), GFP_KERNEL); |
2935 | if (!pg->next) | |
2936 | goto free_pages; | |
2937 | ||
3c1720f0 SR |
2938 | pg = pg->next; |
2939 | } | |
2940 | ||
a7900875 SR |
2941 | return start_pg; |
2942 | ||
2943 | free_pages: | |
1f61be00 NK |
2944 | pg = start_pg; |
2945 | while (pg) { | |
a7900875 SR |
2946 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
2947 | free_pages((unsigned long)pg->records, order); | |
2948 | start_pg = pg->next; | |
2949 | kfree(pg); | |
2950 | pg = start_pg; | |
2951 | } | |
2952 | pr_info("ftrace: FAILED to allocate memory for functions\n"); | |
2953 | return NULL; | |
2954 | } | |
2955 | ||
5072c59f SR |
2956 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ |
2957 | ||
2958 | struct ftrace_iterator { | |
98c4fd04 | 2959 | loff_t pos; |
4aeb6967 SR |
2960 | loff_t func_pos; |
2961 | struct ftrace_page *pg; | |
2962 | struct dyn_ftrace *func; | |
2963 | struct ftrace_func_probe *probe; | |
2964 | struct trace_parser parser; | |
1cf41dd7 | 2965 | struct ftrace_hash *hash; |
33dc9b12 | 2966 | struct ftrace_ops *ops; |
4aeb6967 SR |
2967 | int hidx; |
2968 | int idx; | |
2969 | unsigned flags; | |
5072c59f SR |
2970 | }; |
2971 | ||
8fc0c701 | 2972 | static void * |
4aeb6967 | 2973 | t_hash_next(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
2974 | { |
2975 | struct ftrace_iterator *iter = m->private; | |
4aeb6967 | 2976 | struct hlist_node *hnd = NULL; |
8fc0c701 SR |
2977 | struct hlist_head *hhd; |
2978 | ||
8fc0c701 | 2979 | (*pos)++; |
98c4fd04 | 2980 | iter->pos = *pos; |
8fc0c701 | 2981 | |
4aeb6967 SR |
2982 | if (iter->probe) |
2983 | hnd = &iter->probe->node; | |
8fc0c701 SR |
2984 | retry: |
2985 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
2986 | return NULL; | |
2987 | ||
2988 | hhd = &ftrace_func_hash[iter->hidx]; | |
2989 | ||
2990 | if (hlist_empty(hhd)) { | |
2991 | iter->hidx++; | |
2992 | hnd = NULL; | |
2993 | goto retry; | |
2994 | } | |
2995 | ||
2996 | if (!hnd) | |
2997 | hnd = hhd->first; | |
2998 | else { | |
2999 | hnd = hnd->next; | |
3000 | if (!hnd) { | |
3001 | iter->hidx++; | |
3002 | goto retry; | |
3003 | } | |
3004 | } | |
3005 | ||
4aeb6967 SR |
3006 | if (WARN_ON_ONCE(!hnd)) |
3007 | return NULL; | |
3008 | ||
3009 | iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node); | |
3010 | ||
3011 | return iter; | |
8fc0c701 SR |
3012 | } |
3013 | ||
3014 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
3015 | { | |
3016 | struct ftrace_iterator *iter = m->private; | |
3017 | void *p = NULL; | |
d82d6244 LZ |
3018 | loff_t l; |
3019 | ||
69a3083c SR |
3020 | if (!(iter->flags & FTRACE_ITER_DO_HASH)) |
3021 | return NULL; | |
3022 | ||
2bccfffd SR |
3023 | if (iter->func_pos > *pos) |
3024 | return NULL; | |
8fc0c701 | 3025 | |
d82d6244 | 3026 | iter->hidx = 0; |
2bccfffd | 3027 | for (l = 0; l <= (*pos - iter->func_pos); ) { |
4aeb6967 | 3028 | p = t_hash_next(m, &l); |
d82d6244 LZ |
3029 | if (!p) |
3030 | break; | |
3031 | } | |
4aeb6967 SR |
3032 | if (!p) |
3033 | return NULL; | |
3034 | ||
98c4fd04 SR |
3035 | /* Only set this if we have an item */ |
3036 | iter->flags |= FTRACE_ITER_HASH; | |
3037 | ||
4aeb6967 | 3038 | return iter; |
8fc0c701 SR |
3039 | } |
3040 | ||
4aeb6967 SR |
3041 | static int |
3042 | t_hash_show(struct seq_file *m, struct ftrace_iterator *iter) | |
8fc0c701 | 3043 | { |
b6887d79 | 3044 | struct ftrace_func_probe *rec; |
8fc0c701 | 3045 | |
4aeb6967 SR |
3046 | rec = iter->probe; |
3047 | if (WARN_ON_ONCE(!rec)) | |
3048 | return -EIO; | |
8fc0c701 | 3049 | |
809dcf29 SR |
3050 | if (rec->ops->print) |
3051 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
3052 | ||
b375a11a | 3053 | seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func); |
8fc0c701 SR |
3054 | |
3055 | if (rec->data) | |
3056 | seq_printf(m, ":%p", rec->data); | |
3057 | seq_putc(m, '\n'); | |
3058 | ||
3059 | return 0; | |
3060 | } | |
3061 | ||
e309b41d | 3062 | static void * |
5072c59f SR |
3063 | t_next(struct seq_file *m, void *v, loff_t *pos) |
3064 | { | |
3065 | struct ftrace_iterator *iter = m->private; | |
fc13cb0c | 3066 | struct ftrace_ops *ops = iter->ops; |
5072c59f SR |
3067 | struct dyn_ftrace *rec = NULL; |
3068 | ||
45a4a237 SR |
3069 | if (unlikely(ftrace_disabled)) |
3070 | return NULL; | |
3071 | ||
8fc0c701 | 3072 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 3073 | return t_hash_next(m, pos); |
8fc0c701 | 3074 | |
5072c59f | 3075 | (*pos)++; |
1106b699 | 3076 | iter->pos = iter->func_pos = *pos; |
5072c59f | 3077 | |
0c75a3ed | 3078 | if (iter->flags & FTRACE_ITER_PRINTALL) |
57c072c7 | 3079 | return t_hash_start(m, pos); |
0c75a3ed | 3080 | |
5072c59f SR |
3081 | retry: |
3082 | if (iter->idx >= iter->pg->index) { | |
3083 | if (iter->pg->next) { | |
3084 | iter->pg = iter->pg->next; | |
3085 | iter->idx = 0; | |
3086 | goto retry; | |
3087 | } | |
3088 | } else { | |
3089 | rec = &iter->pg->records[iter->idx++]; | |
32082309 | 3090 | if (((iter->flags & FTRACE_ITER_FILTER) && |
33b7f99c | 3091 | !(ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))) || |
0183fb1c | 3092 | |
41c52c0d | 3093 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
33b7f99c | 3094 | !ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip)) || |
647bcd03 SR |
3095 | |
3096 | ((iter->flags & FTRACE_ITER_ENABLED) && | |
23ea9c4d | 3097 | !(rec->flags & FTRACE_FL_ENABLED))) { |
647bcd03 | 3098 | |
5072c59f SR |
3099 | rec = NULL; |
3100 | goto retry; | |
3101 | } | |
3102 | } | |
3103 | ||
4aeb6967 | 3104 | if (!rec) |
57c072c7 | 3105 | return t_hash_start(m, pos); |
4aeb6967 SR |
3106 | |
3107 | iter->func = rec; | |
3108 | ||
3109 | return iter; | |
5072c59f SR |
3110 | } |
3111 | ||
98c4fd04 SR |
3112 | static void reset_iter_read(struct ftrace_iterator *iter) |
3113 | { | |
3114 | iter->pos = 0; | |
3115 | iter->func_pos = 0; | |
70f77b3f | 3116 | iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_HASH); |
5072c59f SR |
3117 | } |
3118 | ||
3119 | static void *t_start(struct seq_file *m, loff_t *pos) | |
3120 | { | |
3121 | struct ftrace_iterator *iter = m->private; | |
fc13cb0c | 3122 | struct ftrace_ops *ops = iter->ops; |
5072c59f | 3123 | void *p = NULL; |
694ce0a5 | 3124 | loff_t l; |
5072c59f | 3125 | |
8fc0c701 | 3126 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
3127 | |
3128 | if (unlikely(ftrace_disabled)) | |
3129 | return NULL; | |
3130 | ||
98c4fd04 SR |
3131 | /* |
3132 | * If an lseek was done, then reset and start from beginning. | |
3133 | */ | |
3134 | if (*pos < iter->pos) | |
3135 | reset_iter_read(iter); | |
3136 | ||
0c75a3ed SR |
3137 | /* |
3138 | * For set_ftrace_filter reading, if we have the filter | |
3139 | * off, we can short cut and just print out that all | |
3140 | * functions are enabled. | |
3141 | */ | |
8c006cf7 | 3142 | if ((iter->flags & FTRACE_ITER_FILTER && |
33b7f99c | 3143 | ftrace_hash_empty(ops->func_hash->filter_hash)) || |
8c006cf7 | 3144 | (iter->flags & FTRACE_ITER_NOTRACE && |
33b7f99c | 3145 | ftrace_hash_empty(ops->func_hash->notrace_hash))) { |
0c75a3ed | 3146 | if (*pos > 0) |
8fc0c701 | 3147 | return t_hash_start(m, pos); |
0c75a3ed | 3148 | iter->flags |= FTRACE_ITER_PRINTALL; |
df091625 CW |
3149 | /* reset in case of seek/pread */ |
3150 | iter->flags &= ~FTRACE_ITER_HASH; | |
0c75a3ed SR |
3151 | return iter; |
3152 | } | |
3153 | ||
8fc0c701 SR |
3154 | if (iter->flags & FTRACE_ITER_HASH) |
3155 | return t_hash_start(m, pos); | |
3156 | ||
98c4fd04 SR |
3157 | /* |
3158 | * Unfortunately, we need to restart at ftrace_pages_start | |
3159 | * every time we let go of the ftrace_mutex. This is because | |
3160 | * those pointers can change without the lock. | |
3161 | */ | |
694ce0a5 LZ |
3162 | iter->pg = ftrace_pages_start; |
3163 | iter->idx = 0; | |
3164 | for (l = 0; l <= *pos; ) { | |
3165 | p = t_next(m, p, &l); | |
3166 | if (!p) | |
3167 | break; | |
50cdaf08 | 3168 | } |
5821e1b7 | 3169 | |
69a3083c SR |
3170 | if (!p) |
3171 | return t_hash_start(m, pos); | |
4aeb6967 SR |
3172 | |
3173 | return iter; | |
5072c59f SR |
3174 | } |
3175 | ||
3176 | static void t_stop(struct seq_file *m, void *p) | |
3177 | { | |
8fc0c701 | 3178 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
3179 | } |
3180 | ||
15d5b02c SRRH |
3181 | void * __weak |
3182 | arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec) | |
3183 | { | |
3184 | return NULL; | |
3185 | } | |
3186 | ||
3187 | static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops, | |
3188 | struct dyn_ftrace *rec) | |
3189 | { | |
3190 | void *ptr; | |
3191 | ||
3192 | ptr = arch_ftrace_trampoline_func(ops, rec); | |
3193 | if (ptr) | |
3194 | seq_printf(m, " ->%pS", ptr); | |
3195 | } | |
3196 | ||
5072c59f SR |
3197 | static int t_show(struct seq_file *m, void *v) |
3198 | { | |
0c75a3ed | 3199 | struct ftrace_iterator *iter = m->private; |
4aeb6967 | 3200 | struct dyn_ftrace *rec; |
5072c59f | 3201 | |
8fc0c701 | 3202 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 3203 | return t_hash_show(m, iter); |
8fc0c701 | 3204 | |
0c75a3ed | 3205 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
8c006cf7 | 3206 | if (iter->flags & FTRACE_ITER_NOTRACE) |
fa6f0cc7 | 3207 | seq_puts(m, "#### no functions disabled ####\n"); |
8c006cf7 | 3208 | else |
fa6f0cc7 | 3209 | seq_puts(m, "#### all functions enabled ####\n"); |
0c75a3ed SR |
3210 | return 0; |
3211 | } | |
3212 | ||
4aeb6967 SR |
3213 | rec = iter->func; |
3214 | ||
5072c59f SR |
3215 | if (!rec) |
3216 | return 0; | |
3217 | ||
647bcd03 | 3218 | seq_printf(m, "%ps", (void *)rec->ip); |
9674b2fa | 3219 | if (iter->flags & FTRACE_ITER_ENABLED) { |
15d5b02c SRRH |
3220 | struct ftrace_ops *ops = NULL; |
3221 | ||
f8b8be8a | 3222 | seq_printf(m, " (%ld)%s%s", |
0376bde1 | 3223 | ftrace_rec_count(rec), |
f8b8be8a MH |
3224 | rec->flags & FTRACE_FL_REGS ? " R" : " ", |
3225 | rec->flags & FTRACE_FL_IPMODIFY ? " I" : " "); | |
9674b2fa | 3226 | if (rec->flags & FTRACE_FL_TRAMP_EN) { |
5fecaa04 | 3227 | ops = ftrace_find_tramp_ops_any(rec); |
fef5aeee | 3228 | if (ops) |
9674b2fa SRRH |
3229 | seq_printf(m, "\ttramp: %pS", |
3230 | (void *)ops->trampoline); | |
3231 | else | |
fa6f0cc7 | 3232 | seq_puts(m, "\ttramp: ERROR!"); |
15d5b02c | 3233 | |
9674b2fa | 3234 | } |
15d5b02c | 3235 | add_trampoline_func(m, ops, rec); |
9674b2fa SRRH |
3236 | } |
3237 | ||
fa6f0cc7 | 3238 | seq_putc(m, '\n'); |
5072c59f SR |
3239 | |
3240 | return 0; | |
3241 | } | |
3242 | ||
88e9d34c | 3243 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
3244 | .start = t_start, |
3245 | .next = t_next, | |
3246 | .stop = t_stop, | |
3247 | .show = t_show, | |
3248 | }; | |
3249 | ||
e309b41d | 3250 | static int |
5072c59f SR |
3251 | ftrace_avail_open(struct inode *inode, struct file *file) |
3252 | { | |
3253 | struct ftrace_iterator *iter; | |
5072c59f | 3254 | |
4eebcc81 SR |
3255 | if (unlikely(ftrace_disabled)) |
3256 | return -ENODEV; | |
3257 | ||
50e18b94 JO |
3258 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
3259 | if (iter) { | |
3260 | iter->pg = ftrace_pages_start; | |
3261 | iter->ops = &global_ops; | |
4bf39a94 | 3262 | } |
5072c59f | 3263 | |
50e18b94 | 3264 | return iter ? 0 : -ENOMEM; |
5072c59f SR |
3265 | } |
3266 | ||
647bcd03 SR |
3267 | static int |
3268 | ftrace_enabled_open(struct inode *inode, struct file *file) | |
3269 | { | |
3270 | struct ftrace_iterator *iter; | |
647bcd03 | 3271 | |
50e18b94 JO |
3272 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
3273 | if (iter) { | |
3274 | iter->pg = ftrace_pages_start; | |
3275 | iter->flags = FTRACE_ITER_ENABLED; | |
3276 | iter->ops = &global_ops; | |
647bcd03 SR |
3277 | } |
3278 | ||
50e18b94 | 3279 | return iter ? 0 : -ENOMEM; |
647bcd03 SR |
3280 | } |
3281 | ||
fc13cb0c SR |
3282 | /** |
3283 | * ftrace_regex_open - initialize function tracer filter files | |
3284 | * @ops: The ftrace_ops that hold the hash filters | |
3285 | * @flag: The type of filter to process | |
3286 | * @inode: The inode, usually passed in to your open routine | |
3287 | * @file: The file, usually passed in to your open routine | |
3288 | * | |
3289 | * ftrace_regex_open() initializes the filter files for the | |
3290 | * @ops. Depending on @flag it may process the filter hash or | |
3291 | * the notrace hash of @ops. With this called from the open | |
3292 | * routine, you can use ftrace_filter_write() for the write | |
3293 | * routine if @flag has FTRACE_ITER_FILTER set, or | |
3294 | * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set. | |
098c879e | 3295 | * tracing_lseek() should be used as the lseek routine, and |
fc13cb0c SR |
3296 | * release must call ftrace_regex_release(). |
3297 | */ | |
3298 | int | |
f45948e8 | 3299 | ftrace_regex_open(struct ftrace_ops *ops, int flag, |
1cf41dd7 | 3300 | struct inode *inode, struct file *file) |
5072c59f SR |
3301 | { |
3302 | struct ftrace_iterator *iter; | |
f45948e8 | 3303 | struct ftrace_hash *hash; |
5072c59f SR |
3304 | int ret = 0; |
3305 | ||
f04f24fb MH |
3306 | ftrace_ops_init(ops); |
3307 | ||
4eebcc81 SR |
3308 | if (unlikely(ftrace_disabled)) |
3309 | return -ENODEV; | |
3310 | ||
5072c59f SR |
3311 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
3312 | if (!iter) | |
3313 | return -ENOMEM; | |
3314 | ||
689fd8b6 | 3315 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) { |
3316 | kfree(iter); | |
3317 | return -ENOMEM; | |
3318 | } | |
3319 | ||
3f2367ba MH |
3320 | iter->ops = ops; |
3321 | iter->flags = flag; | |
3322 | ||
33b7f99c | 3323 | mutex_lock(&ops->func_hash->regex_lock); |
3f2367ba | 3324 | |
f45948e8 | 3325 | if (flag & FTRACE_ITER_NOTRACE) |
33b7f99c | 3326 | hash = ops->func_hash->notrace_hash; |
f45948e8 | 3327 | else |
33b7f99c | 3328 | hash = ops->func_hash->filter_hash; |
f45948e8 | 3329 | |
33dc9b12 | 3330 | if (file->f_mode & FMODE_WRITE) { |
ef2fbe16 NK |
3331 | const int size_bits = FTRACE_HASH_DEFAULT_BITS; |
3332 | ||
3333 | if (file->f_flags & O_TRUNC) | |
3334 | iter->hash = alloc_ftrace_hash(size_bits); | |
3335 | else | |
3336 | iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash); | |
3337 | ||
33dc9b12 SR |
3338 | if (!iter->hash) { |
3339 | trace_parser_put(&iter->parser); | |
3340 | kfree(iter); | |
3f2367ba MH |
3341 | ret = -ENOMEM; |
3342 | goto out_unlock; | |
33dc9b12 SR |
3343 | } |
3344 | } | |
1cf41dd7 | 3345 | |
5072c59f SR |
3346 | if (file->f_mode & FMODE_READ) { |
3347 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
3348 | |
3349 | ret = seq_open(file, &show_ftrace_seq_ops); | |
3350 | if (!ret) { | |
3351 | struct seq_file *m = file->private_data; | |
3352 | m->private = iter; | |
79fe249c | 3353 | } else { |
33dc9b12 SR |
3354 | /* Failed */ |
3355 | free_ftrace_hash(iter->hash); | |
79fe249c | 3356 | trace_parser_put(&iter->parser); |
5072c59f | 3357 | kfree(iter); |
79fe249c | 3358 | } |
5072c59f SR |
3359 | } else |
3360 | file->private_data = iter; | |
3f2367ba MH |
3361 | |
3362 | out_unlock: | |
33b7f99c | 3363 | mutex_unlock(&ops->func_hash->regex_lock); |
5072c59f SR |
3364 | |
3365 | return ret; | |
3366 | } | |
3367 | ||
41c52c0d SR |
3368 | static int |
3369 | ftrace_filter_open(struct inode *inode, struct file *file) | |
3370 | { | |
e3b3e2e8 SRRH |
3371 | struct ftrace_ops *ops = inode->i_private; |
3372 | ||
3373 | return ftrace_regex_open(ops, | |
69a3083c SR |
3374 | FTRACE_ITER_FILTER | FTRACE_ITER_DO_HASH, |
3375 | inode, file); | |
41c52c0d SR |
3376 | } |
3377 | ||
3378 | static int | |
3379 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
3380 | { | |
e3b3e2e8 SRRH |
3381 | struct ftrace_ops *ops = inode->i_private; |
3382 | ||
3383 | return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE, | |
1cf41dd7 | 3384 | inode, file); |
41c52c0d SR |
3385 | } |
3386 | ||
64e7c440 | 3387 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 3388 | { |
9f4801e3 | 3389 | int matched = 0; |
751e9983 | 3390 | int slen; |
9f4801e3 | 3391 | |
9f4801e3 SR |
3392 | switch (type) { |
3393 | case MATCH_FULL: | |
3394 | if (strcmp(str, regex) == 0) | |
3395 | matched = 1; | |
3396 | break; | |
3397 | case MATCH_FRONT_ONLY: | |
3398 | if (strncmp(str, regex, len) == 0) | |
3399 | matched = 1; | |
3400 | break; | |
3401 | case MATCH_MIDDLE_ONLY: | |
3402 | if (strstr(str, regex)) | |
3403 | matched = 1; | |
3404 | break; | |
3405 | case MATCH_END_ONLY: | |
751e9983 LZ |
3406 | slen = strlen(str); |
3407 | if (slen >= len && memcmp(str + slen - len, regex, len) == 0) | |
9f4801e3 SR |
3408 | matched = 1; |
3409 | break; | |
3410 | } | |
3411 | ||
3412 | return matched; | |
3413 | } | |
3414 | ||
b448c4e3 | 3415 | static int |
1cf41dd7 | 3416 | enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not) |
996e87be | 3417 | { |
b448c4e3 | 3418 | struct ftrace_func_entry *entry; |
b448c4e3 SR |
3419 | int ret = 0; |
3420 | ||
1cf41dd7 SR |
3421 | entry = ftrace_lookup_ip(hash, rec->ip); |
3422 | if (not) { | |
3423 | /* Do nothing if it doesn't exist */ | |
3424 | if (!entry) | |
3425 | return 0; | |
b448c4e3 | 3426 | |
33dc9b12 | 3427 | free_hash_entry(hash, entry); |
1cf41dd7 SR |
3428 | } else { |
3429 | /* Do nothing if it exists */ | |
3430 | if (entry) | |
3431 | return 0; | |
b448c4e3 | 3432 | |
1cf41dd7 | 3433 | ret = add_hash_entry(hash, rec->ip); |
b448c4e3 SR |
3434 | } |
3435 | return ret; | |
996e87be SR |
3436 | } |
3437 | ||
64e7c440 | 3438 | static int |
b9df92d2 SR |
3439 | ftrace_match_record(struct dyn_ftrace *rec, char *mod, |
3440 | char *regex, int len, int type) | |
64e7c440 SR |
3441 | { |
3442 | char str[KSYM_SYMBOL_LEN]; | |
b9df92d2 SR |
3443 | char *modname; |
3444 | ||
3445 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
3446 | ||
3447 | if (mod) { | |
3448 | /* module lookup requires matching the module */ | |
3449 | if (!modname || strcmp(modname, mod)) | |
3450 | return 0; | |
3451 | ||
3452 | /* blank search means to match all funcs in the mod */ | |
3453 | if (!len) | |
3454 | return 1; | |
3455 | } | |
64e7c440 | 3456 | |
64e7c440 SR |
3457 | return ftrace_match(str, regex, len, type); |
3458 | } | |
3459 | ||
1cf41dd7 SR |
3460 | static int |
3461 | match_records(struct ftrace_hash *hash, char *buff, | |
3462 | int len, char *mod, int not) | |
9f4801e3 | 3463 | { |
b9df92d2 | 3464 | unsigned search_len = 0; |
9f4801e3 SR |
3465 | struct ftrace_page *pg; |
3466 | struct dyn_ftrace *rec; | |
b9df92d2 SR |
3467 | int type = MATCH_FULL; |
3468 | char *search = buff; | |
311d16da | 3469 | int found = 0; |
b448c4e3 | 3470 | int ret; |
9f4801e3 | 3471 | |
b9df92d2 SR |
3472 | if (len) { |
3473 | type = filter_parse_regex(buff, len, &search, ¬); | |
3474 | search_len = strlen(search); | |
3475 | } | |
9f4801e3 | 3476 | |
52baf119 | 3477 | mutex_lock(&ftrace_lock); |
265c831c | 3478 | |
b9df92d2 SR |
3479 | if (unlikely(ftrace_disabled)) |
3480 | goto out_unlock; | |
9f4801e3 | 3481 | |
265c831c | 3482 | do_for_each_ftrace_rec(pg, rec) { |
b9df92d2 | 3483 | if (ftrace_match_record(rec, mod, search, search_len, type)) { |
1cf41dd7 | 3484 | ret = enter_record(hash, rec, not); |
b448c4e3 SR |
3485 | if (ret < 0) { |
3486 | found = ret; | |
3487 | goto out_unlock; | |
3488 | } | |
311d16da | 3489 | found = 1; |
265c831c SR |
3490 | } |
3491 | } while_for_each_ftrace_rec(); | |
b9df92d2 | 3492 | out_unlock: |
52baf119 | 3493 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
3494 | |
3495 | return found; | |
5072c59f SR |
3496 | } |
3497 | ||
64e7c440 | 3498 | static int |
1cf41dd7 | 3499 | ftrace_match_records(struct ftrace_hash *hash, char *buff, int len) |
64e7c440 | 3500 | { |
1cf41dd7 | 3501 | return match_records(hash, buff, len, NULL, 0); |
64e7c440 SR |
3502 | } |
3503 | ||
1cf41dd7 SR |
3504 | static int |
3505 | ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod) | |
64e7c440 | 3506 | { |
64e7c440 | 3507 | int not = 0; |
6a24a244 | 3508 | |
64e7c440 SR |
3509 | /* blank or '*' mean the same */ |
3510 | if (strcmp(buff, "*") == 0) | |
3511 | buff[0] = 0; | |
3512 | ||
3513 | /* handle the case of 'dont filter this module' */ | |
3514 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
3515 | buff[0] = 0; | |
3516 | not = 1; | |
3517 | } | |
3518 | ||
1cf41dd7 | 3519 | return match_records(hash, buff, strlen(buff), mod, not); |
64e7c440 SR |
3520 | } |
3521 | ||
f6180773 SR |
3522 | /* |
3523 | * We register the module command as a template to show others how | |
3524 | * to register the a command as well. | |
3525 | */ | |
3526 | ||
3527 | static int | |
43dd61c9 SR |
3528 | ftrace_mod_callback(struct ftrace_hash *hash, |
3529 | char *func, char *cmd, char *param, int enable) | |
f6180773 SR |
3530 | { |
3531 | char *mod; | |
b448c4e3 | 3532 | int ret = -EINVAL; |
f6180773 SR |
3533 | |
3534 | /* | |
3535 | * cmd == 'mod' because we only registered this func | |
3536 | * for the 'mod' ftrace_func_command. | |
3537 | * But if you register one func with multiple commands, | |
3538 | * you can tell which command was used by the cmd | |
3539 | * parameter. | |
3540 | */ | |
3541 | ||
3542 | /* we must have a module name */ | |
3543 | if (!param) | |
b448c4e3 | 3544 | return ret; |
f6180773 SR |
3545 | |
3546 | mod = strsep(¶m, ":"); | |
3547 | if (!strlen(mod)) | |
b448c4e3 | 3548 | return ret; |
f6180773 | 3549 | |
1cf41dd7 | 3550 | ret = ftrace_match_module_records(hash, func, mod); |
b448c4e3 SR |
3551 | if (!ret) |
3552 | ret = -EINVAL; | |
3553 | if (ret < 0) | |
3554 | return ret; | |
3555 | ||
3556 | return 0; | |
f6180773 SR |
3557 | } |
3558 | ||
3559 | static struct ftrace_func_command ftrace_mod_cmd = { | |
3560 | .name = "mod", | |
3561 | .func = ftrace_mod_callback, | |
3562 | }; | |
3563 | ||
3564 | static int __init ftrace_mod_cmd_init(void) | |
3565 | { | |
3566 | return register_ftrace_command(&ftrace_mod_cmd); | |
3567 | } | |
6f415672 | 3568 | core_initcall(ftrace_mod_cmd_init); |
f6180773 | 3569 | |
2f5f6ad9 | 3570 | static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 3571 | struct ftrace_ops *op, struct pt_regs *pt_regs) |
59df055f | 3572 | { |
b6887d79 | 3573 | struct ftrace_func_probe *entry; |
59df055f | 3574 | struct hlist_head *hhd; |
59df055f | 3575 | unsigned long key; |
59df055f SR |
3576 | |
3577 | key = hash_long(ip, FTRACE_HASH_BITS); | |
3578 | ||
3579 | hhd = &ftrace_func_hash[key]; | |
3580 | ||
3581 | if (hlist_empty(hhd)) | |
3582 | return; | |
3583 | ||
3584 | /* | |
3585 | * Disable preemption for these calls to prevent a RCU grace | |
3586 | * period. This syncs the hash iteration and freeing of items | |
3587 | * on the hash. rcu_read_lock is too dangerous here. | |
3588 | */ | |
5168ae50 | 3589 | preempt_disable_notrace(); |
1bb539ca | 3590 | hlist_for_each_entry_rcu_notrace(entry, hhd, node) { |
59df055f SR |
3591 | if (entry->ip == ip) |
3592 | entry->ops->func(ip, parent_ip, &entry->data); | |
3593 | } | |
5168ae50 | 3594 | preempt_enable_notrace(); |
59df055f SR |
3595 | } |
3596 | ||
b6887d79 | 3597 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 3598 | { |
fb9fb015 | 3599 | .func = function_trace_probe_call, |
f04f24fb | 3600 | .flags = FTRACE_OPS_FL_INITIALIZED, |
33b7f99c | 3601 | INIT_OPS_HASH(trace_probe_ops) |
59df055f SR |
3602 | }; |
3603 | ||
b6887d79 | 3604 | static int ftrace_probe_registered; |
59df055f | 3605 | |
7485058e | 3606 | static void __enable_ftrace_function_probe(struct ftrace_ops_hash *old_hash) |
59df055f | 3607 | { |
b848914c | 3608 | int ret; |
59df055f SR |
3609 | int i; |
3610 | ||
19dd603e SRRH |
3611 | if (ftrace_probe_registered) { |
3612 | /* still need to update the function call sites */ | |
3613 | if (ftrace_enabled) | |
8252ecf3 SRRH |
3614 | ftrace_run_modify_code(&trace_probe_ops, FTRACE_UPDATE_CALLS, |
3615 | old_hash); | |
59df055f | 3616 | return; |
19dd603e | 3617 | } |
59df055f SR |
3618 | |
3619 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
3620 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
3621 | if (hhd->first) | |
3622 | break; | |
3623 | } | |
3624 | /* Nothing registered? */ | |
3625 | if (i == FTRACE_FUNC_HASHSIZE) | |
3626 | return; | |
3627 | ||
8a56d776 | 3628 | ret = ftrace_startup(&trace_probe_ops, 0); |
b848914c | 3629 | |
b6887d79 | 3630 | ftrace_probe_registered = 1; |
59df055f SR |
3631 | } |
3632 | ||
b6887d79 | 3633 | static void __disable_ftrace_function_probe(void) |
59df055f SR |
3634 | { |
3635 | int i; | |
3636 | ||
b6887d79 | 3637 | if (!ftrace_probe_registered) |
59df055f SR |
3638 | return; |
3639 | ||
3640 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
3641 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
3642 | if (hhd->first) | |
3643 | return; | |
3644 | } | |
3645 | ||
3646 | /* no more funcs left */ | |
8a56d776 | 3647 | ftrace_shutdown(&trace_probe_ops, 0); |
b848914c | 3648 | |
b6887d79 | 3649 | ftrace_probe_registered = 0; |
59df055f SR |
3650 | } |
3651 | ||
3652 | ||
7818b388 | 3653 | static void ftrace_free_entry(struct ftrace_func_probe *entry) |
59df055f | 3654 | { |
59df055f | 3655 | if (entry->ops->free) |
e67efb93 | 3656 | entry->ops->free(entry->ops, entry->ip, &entry->data); |
59df055f SR |
3657 | kfree(entry); |
3658 | } | |
3659 | ||
59df055f | 3660 | int |
b6887d79 | 3661 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3662 | void *data) |
3663 | { | |
7485058e | 3664 | struct ftrace_ops_hash old_hash_ops; |
b6887d79 | 3665 | struct ftrace_func_probe *entry; |
33b7f99c | 3666 | struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash; |
3296fc4e | 3667 | struct ftrace_hash *old_hash = *orig_hash; |
e1df4cb6 | 3668 | struct ftrace_hash *hash; |
59df055f SR |
3669 | struct ftrace_page *pg; |
3670 | struct dyn_ftrace *rec; | |
59df055f | 3671 | int type, len, not; |
6a24a244 | 3672 | unsigned long key; |
59df055f SR |
3673 | int count = 0; |
3674 | char *search; | |
e1df4cb6 | 3675 | int ret; |
59df055f | 3676 | |
3f6fe06d | 3677 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
3678 | len = strlen(search); |
3679 | ||
b6887d79 | 3680 | /* we do not support '!' for function probes */ |
59df055f SR |
3681 | if (WARN_ON(not)) |
3682 | return -EINVAL; | |
3683 | ||
33b7f99c | 3684 | mutex_lock(&trace_probe_ops.func_hash->regex_lock); |
59df055f | 3685 | |
7485058e SRRH |
3686 | old_hash_ops.filter_hash = old_hash; |
3687 | /* Probes only have filters */ | |
3688 | old_hash_ops.notrace_hash = NULL; | |
3689 | ||
3296fc4e | 3690 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); |
e1df4cb6 SRRH |
3691 | if (!hash) { |
3692 | count = -ENOMEM; | |
5ae0bf59 | 3693 | goto out; |
e1df4cb6 SRRH |
3694 | } |
3695 | ||
3696 | if (unlikely(ftrace_disabled)) { | |
3697 | count = -ENODEV; | |
5ae0bf59 | 3698 | goto out; |
e1df4cb6 | 3699 | } |
59df055f | 3700 | |
5ae0bf59 SRRH |
3701 | mutex_lock(&ftrace_lock); |
3702 | ||
45a4a237 | 3703 | do_for_each_ftrace_rec(pg, rec) { |
59df055f | 3704 | |
b9df92d2 | 3705 | if (!ftrace_match_record(rec, NULL, search, len, type)) |
59df055f SR |
3706 | continue; |
3707 | ||
3708 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
3709 | if (!entry) { | |
b6887d79 | 3710 | /* If we did not process any, then return error */ |
59df055f SR |
3711 | if (!count) |
3712 | count = -ENOMEM; | |
3713 | goto out_unlock; | |
3714 | } | |
3715 | ||
3716 | count++; | |
3717 | ||
3718 | entry->data = data; | |
3719 | ||
3720 | /* | |
3721 | * The caller might want to do something special | |
3722 | * for each function we find. We call the callback | |
3723 | * to give the caller an opportunity to do so. | |
3724 | */ | |
e67efb93 SRRH |
3725 | if (ops->init) { |
3726 | if (ops->init(ops, rec->ip, &entry->data) < 0) { | |
59df055f SR |
3727 | /* caller does not like this func */ |
3728 | kfree(entry); | |
3729 | continue; | |
3730 | } | |
3731 | } | |
3732 | ||
e1df4cb6 SRRH |
3733 | ret = enter_record(hash, rec, 0); |
3734 | if (ret < 0) { | |
3735 | kfree(entry); | |
3736 | count = ret; | |
3737 | goto out_unlock; | |
3738 | } | |
3739 | ||
59df055f SR |
3740 | entry->ops = ops; |
3741 | entry->ip = rec->ip; | |
3742 | ||
3743 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
3744 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
3745 | ||
3746 | } while_for_each_ftrace_rec(); | |
e1df4cb6 SRRH |
3747 | |
3748 | ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash); | |
8252ecf3 | 3749 | |
7485058e | 3750 | __enable_ftrace_function_probe(&old_hash_ops); |
8252ecf3 | 3751 | |
3296fc4e SRRH |
3752 | if (!ret) |
3753 | free_ftrace_hash_rcu(old_hash); | |
3754 | else | |
e1df4cb6 SRRH |
3755 | count = ret; |
3756 | ||
59df055f | 3757 | out_unlock: |
5ae0bf59 SRRH |
3758 | mutex_unlock(&ftrace_lock); |
3759 | out: | |
33b7f99c | 3760 | mutex_unlock(&trace_probe_ops.func_hash->regex_lock); |
e1df4cb6 | 3761 | free_ftrace_hash(hash); |
59df055f SR |
3762 | |
3763 | return count; | |
3764 | } | |
3765 | ||
3766 | enum { | |
b6887d79 SR |
3767 | PROBE_TEST_FUNC = 1, |
3768 | PROBE_TEST_DATA = 2 | |
59df055f SR |
3769 | }; |
3770 | ||
3771 | static void | |
b6887d79 | 3772 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3773 | void *data, int flags) |
3774 | { | |
e1df4cb6 | 3775 | struct ftrace_func_entry *rec_entry; |
b6887d79 | 3776 | struct ftrace_func_probe *entry; |
7818b388 | 3777 | struct ftrace_func_probe *p; |
33b7f99c | 3778 | struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash; |
3296fc4e | 3779 | struct ftrace_hash *old_hash = *orig_hash; |
7818b388 | 3780 | struct list_head free_list; |
e1df4cb6 | 3781 | struct ftrace_hash *hash; |
b67bfe0d | 3782 | struct hlist_node *tmp; |
59df055f SR |
3783 | char str[KSYM_SYMBOL_LEN]; |
3784 | int type = MATCH_FULL; | |
3785 | int i, len = 0; | |
3786 | char *search; | |
3296fc4e | 3787 | int ret; |
59df055f | 3788 | |
b36461da | 3789 | if (glob && (strcmp(glob, "*") == 0 || !strlen(glob))) |
59df055f | 3790 | glob = NULL; |
b36461da | 3791 | else if (glob) { |
59df055f SR |
3792 | int not; |
3793 | ||
3f6fe06d | 3794 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
3795 | len = strlen(search); |
3796 | ||
b6887d79 | 3797 | /* we do not support '!' for function probes */ |
59df055f SR |
3798 | if (WARN_ON(not)) |
3799 | return; | |
3800 | } | |
3801 | ||
33b7f99c | 3802 | mutex_lock(&trace_probe_ops.func_hash->regex_lock); |
e1df4cb6 SRRH |
3803 | |
3804 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
3805 | if (!hash) | |
3806 | /* Hmm, should report this somehow */ | |
3807 | goto out_unlock; | |
3808 | ||
7818b388 SRRH |
3809 | INIT_LIST_HEAD(&free_list); |
3810 | ||
59df055f SR |
3811 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { |
3812 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
3813 | ||
b67bfe0d | 3814 | hlist_for_each_entry_safe(entry, tmp, hhd, node) { |
59df055f SR |
3815 | |
3816 | /* break up if statements for readability */ | |
b6887d79 | 3817 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
3818 | continue; |
3819 | ||
b6887d79 | 3820 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
3821 | continue; |
3822 | ||
3823 | /* do this last, since it is the most expensive */ | |
3824 | if (glob) { | |
3825 | kallsyms_lookup(entry->ip, NULL, NULL, | |
3826 | NULL, str); | |
3827 | if (!ftrace_match(str, glob, len, type)) | |
3828 | continue; | |
3829 | } | |
3830 | ||
e1df4cb6 SRRH |
3831 | rec_entry = ftrace_lookup_ip(hash, entry->ip); |
3832 | /* It is possible more than one entry had this ip */ | |
3833 | if (rec_entry) | |
3834 | free_hash_entry(hash, rec_entry); | |
3835 | ||
740466bc | 3836 | hlist_del_rcu(&entry->node); |
7818b388 | 3837 | list_add(&entry->free_list, &free_list); |
59df055f SR |
3838 | } |
3839 | } | |
3f2367ba | 3840 | mutex_lock(&ftrace_lock); |
b6887d79 | 3841 | __disable_ftrace_function_probe(); |
e1df4cb6 SRRH |
3842 | /* |
3843 | * Remove after the disable is called. Otherwise, if the last | |
3844 | * probe is removed, a null hash means *all enabled*. | |
3845 | */ | |
3296fc4e | 3846 | ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash); |
7818b388 | 3847 | synchronize_sched(); |
3296fc4e SRRH |
3848 | if (!ret) |
3849 | free_ftrace_hash_rcu(old_hash); | |
3850 | ||
7818b388 SRRH |
3851 | list_for_each_entry_safe(entry, p, &free_list, free_list) { |
3852 | list_del(&entry->free_list); | |
3853 | ftrace_free_entry(entry); | |
3854 | } | |
3f2367ba | 3855 | mutex_unlock(&ftrace_lock); |
7818b388 | 3856 | |
e1df4cb6 | 3857 | out_unlock: |
33b7f99c | 3858 | mutex_unlock(&trace_probe_ops.func_hash->regex_lock); |
e1df4cb6 | 3859 | free_ftrace_hash(hash); |
59df055f SR |
3860 | } |
3861 | ||
3862 | void | |
b6887d79 | 3863 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3864 | void *data) |
3865 | { | |
b6887d79 SR |
3866 | __unregister_ftrace_function_probe(glob, ops, data, |
3867 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
3868 | } |
3869 | ||
3870 | void | |
b6887d79 | 3871 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 3872 | { |
b6887d79 | 3873 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
3874 | } |
3875 | ||
b6887d79 | 3876 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 3877 | { |
b6887d79 | 3878 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
3879 | } |
3880 | ||
f6180773 SR |
3881 | static LIST_HEAD(ftrace_commands); |
3882 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
3883 | ||
38de93ab TZ |
3884 | /* |
3885 | * Currently we only register ftrace commands from __init, so mark this | |
3886 | * __init too. | |
3887 | */ | |
3888 | __init int register_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
3889 | { |
3890 | struct ftrace_func_command *p; | |
3891 | int ret = 0; | |
3892 | ||
3893 | mutex_lock(&ftrace_cmd_mutex); | |
3894 | list_for_each_entry(p, &ftrace_commands, list) { | |
3895 | if (strcmp(cmd->name, p->name) == 0) { | |
3896 | ret = -EBUSY; | |
3897 | goto out_unlock; | |
3898 | } | |
3899 | } | |
3900 | list_add(&cmd->list, &ftrace_commands); | |
3901 | out_unlock: | |
3902 | mutex_unlock(&ftrace_cmd_mutex); | |
3903 | ||
3904 | return ret; | |
3905 | } | |
3906 | ||
38de93ab TZ |
3907 | /* |
3908 | * Currently we only unregister ftrace commands from __init, so mark | |
3909 | * this __init too. | |
3910 | */ | |
3911 | __init int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
3912 | { |
3913 | struct ftrace_func_command *p, *n; | |
3914 | int ret = -ENODEV; | |
3915 | ||
3916 | mutex_lock(&ftrace_cmd_mutex); | |
3917 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
3918 | if (strcmp(cmd->name, p->name) == 0) { | |
3919 | ret = 0; | |
3920 | list_del_init(&p->list); | |
3921 | goto out_unlock; | |
3922 | } | |
3923 | } | |
3924 | out_unlock: | |
3925 | mutex_unlock(&ftrace_cmd_mutex); | |
3926 | ||
3927 | return ret; | |
3928 | } | |
3929 | ||
33dc9b12 SR |
3930 | static int ftrace_process_regex(struct ftrace_hash *hash, |
3931 | char *buff, int len, int enable) | |
64e7c440 | 3932 | { |
f6180773 | 3933 | char *func, *command, *next = buff; |
6a24a244 | 3934 | struct ftrace_func_command *p; |
0aff1c0c | 3935 | int ret = -EINVAL; |
64e7c440 SR |
3936 | |
3937 | func = strsep(&next, ":"); | |
3938 | ||
3939 | if (!next) { | |
1cf41dd7 | 3940 | ret = ftrace_match_records(hash, func, len); |
b448c4e3 SR |
3941 | if (!ret) |
3942 | ret = -EINVAL; | |
3943 | if (ret < 0) | |
3944 | return ret; | |
3945 | return 0; | |
64e7c440 SR |
3946 | } |
3947 | ||
f6180773 | 3948 | /* command found */ |
64e7c440 SR |
3949 | |
3950 | command = strsep(&next, ":"); | |
3951 | ||
f6180773 SR |
3952 | mutex_lock(&ftrace_cmd_mutex); |
3953 | list_for_each_entry(p, &ftrace_commands, list) { | |
3954 | if (strcmp(p->name, command) == 0) { | |
43dd61c9 | 3955 | ret = p->func(hash, func, command, next, enable); |
f6180773 SR |
3956 | goto out_unlock; |
3957 | } | |
64e7c440 | 3958 | } |
f6180773 SR |
3959 | out_unlock: |
3960 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 3961 | |
f6180773 | 3962 | return ret; |
64e7c440 SR |
3963 | } |
3964 | ||
e309b41d | 3965 | static ssize_t |
41c52c0d SR |
3966 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
3967 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
3968 | { |
3969 | struct ftrace_iterator *iter; | |
689fd8b6 | 3970 | struct trace_parser *parser; |
3971 | ssize_t ret, read; | |
5072c59f | 3972 | |
4ba7978e | 3973 | if (!cnt) |
5072c59f SR |
3974 | return 0; |
3975 | ||
5072c59f SR |
3976 | if (file->f_mode & FMODE_READ) { |
3977 | struct seq_file *m = file->private_data; | |
3978 | iter = m->private; | |
3979 | } else | |
3980 | iter = file->private_data; | |
3981 | ||
f04f24fb | 3982 | if (unlikely(ftrace_disabled)) |
3f2367ba MH |
3983 | return -ENODEV; |
3984 | ||
3985 | /* iter->hash is a local copy, so we don't need regex_lock */ | |
f04f24fb | 3986 | |
689fd8b6 | 3987 | parser = &iter->parser; |
3988 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 3989 | |
4ba7978e | 3990 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 3991 | !trace_parser_cont(parser)) { |
33dc9b12 | 3992 | ret = ftrace_process_regex(iter->hash, parser->buffer, |
689fd8b6 | 3993 | parser->idx, enable); |
313254a9 | 3994 | trace_parser_clear(parser); |
7c088b51 | 3995 | if (ret < 0) |
3f2367ba | 3996 | goto out; |
eda1e328 | 3997 | } |
5072c59f | 3998 | |
5072c59f | 3999 | ret = read; |
3f2367ba | 4000 | out: |
5072c59f SR |
4001 | return ret; |
4002 | } | |
4003 | ||
fc13cb0c | 4004 | ssize_t |
41c52c0d SR |
4005 | ftrace_filter_write(struct file *file, const char __user *ubuf, |
4006 | size_t cnt, loff_t *ppos) | |
4007 | { | |
4008 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
4009 | } | |
4010 | ||
fc13cb0c | 4011 | ssize_t |
41c52c0d SR |
4012 | ftrace_notrace_write(struct file *file, const char __user *ubuf, |
4013 | size_t cnt, loff_t *ppos) | |
4014 | { | |
4015 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
4016 | } | |
4017 | ||
33dc9b12 | 4018 | static int |
647664ea MH |
4019 | ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) |
4020 | { | |
4021 | struct ftrace_func_entry *entry; | |
4022 | ||
4023 | if (!ftrace_location(ip)) | |
4024 | return -EINVAL; | |
4025 | ||
4026 | if (remove) { | |
4027 | entry = ftrace_lookup_ip(hash, ip); | |
4028 | if (!entry) | |
4029 | return -ENOENT; | |
4030 | free_hash_entry(hash, entry); | |
4031 | return 0; | |
4032 | } | |
4033 | ||
4034 | return add_hash_entry(hash, ip); | |
4035 | } | |
4036 | ||
8252ecf3 | 4037 | static void ftrace_ops_update_code(struct ftrace_ops *ops, |
7485058e | 4038 | struct ftrace_ops_hash *old_hash) |
1c80c432 | 4039 | { |
8f86f837 SRRH |
4040 | struct ftrace_ops *op; |
4041 | ||
4042 | if (!ftrace_enabled) | |
4043 | return; | |
4044 | ||
4045 | if (ops->flags & FTRACE_OPS_FL_ENABLED) { | |
8252ecf3 | 4046 | ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash); |
8f86f837 SRRH |
4047 | return; |
4048 | } | |
4049 | ||
4050 | /* | |
4051 | * If this is the shared global_ops filter, then we need to | |
4052 | * check if there is another ops that shares it, is enabled. | |
4053 | * If so, we still need to run the modify code. | |
4054 | */ | |
4055 | if (ops->func_hash != &global_ops.local_hash) | |
4056 | return; | |
4057 | ||
4058 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
4059 | if (op->func_hash == &global_ops.local_hash && | |
4060 | op->flags & FTRACE_OPS_FL_ENABLED) { | |
4061 | ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash); | |
4062 | /* Only need to do this once */ | |
4063 | return; | |
4064 | } | |
4065 | } while_for_each_ftrace_op(op); | |
1c80c432 SRRH |
4066 | } |
4067 | ||
647664ea MH |
4068 | static int |
4069 | ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, | |
4070 | unsigned long ip, int remove, int reset, int enable) | |
41c52c0d | 4071 | { |
33dc9b12 | 4072 | struct ftrace_hash **orig_hash; |
7485058e | 4073 | struct ftrace_ops_hash old_hash_ops; |
3296fc4e | 4074 | struct ftrace_hash *old_hash; |
f45948e8 | 4075 | struct ftrace_hash *hash; |
33dc9b12 | 4076 | int ret; |
f45948e8 | 4077 | |
41c52c0d | 4078 | if (unlikely(ftrace_disabled)) |
33dc9b12 | 4079 | return -ENODEV; |
41c52c0d | 4080 | |
33b7f99c | 4081 | mutex_lock(&ops->func_hash->regex_lock); |
3f2367ba | 4082 | |
f45948e8 | 4083 | if (enable) |
33b7f99c | 4084 | orig_hash = &ops->func_hash->filter_hash; |
f45948e8 | 4085 | else |
33b7f99c | 4086 | orig_hash = &ops->func_hash->notrace_hash; |
33dc9b12 | 4087 | |
b972cc58 WN |
4088 | if (reset) |
4089 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); | |
4090 | else | |
4091 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
4092 | ||
3f2367ba MH |
4093 | if (!hash) { |
4094 | ret = -ENOMEM; | |
4095 | goto out_regex_unlock; | |
4096 | } | |
f45948e8 | 4097 | |
ac483c44 JO |
4098 | if (buf && !ftrace_match_records(hash, buf, len)) { |
4099 | ret = -EINVAL; | |
4100 | goto out_regex_unlock; | |
4101 | } | |
647664ea MH |
4102 | if (ip) { |
4103 | ret = ftrace_match_addr(hash, ip, remove); | |
4104 | if (ret < 0) | |
4105 | goto out_regex_unlock; | |
4106 | } | |
33dc9b12 SR |
4107 | |
4108 | mutex_lock(&ftrace_lock); | |
3296fc4e | 4109 | old_hash = *orig_hash; |
7485058e SRRH |
4110 | old_hash_ops.filter_hash = ops->func_hash->filter_hash; |
4111 | old_hash_ops.notrace_hash = ops->func_hash->notrace_hash; | |
41fb61c2 | 4112 | ret = ftrace_hash_move(ops, enable, orig_hash, hash); |
3296fc4e | 4113 | if (!ret) { |
7485058e | 4114 | ftrace_ops_update_code(ops, &old_hash_ops); |
3296fc4e SRRH |
4115 | free_ftrace_hash_rcu(old_hash); |
4116 | } | |
33dc9b12 SR |
4117 | mutex_unlock(&ftrace_lock); |
4118 | ||
ac483c44 | 4119 | out_regex_unlock: |
33b7f99c | 4120 | mutex_unlock(&ops->func_hash->regex_lock); |
33dc9b12 SR |
4121 | |
4122 | free_ftrace_hash(hash); | |
4123 | return ret; | |
41c52c0d SR |
4124 | } |
4125 | ||
647664ea MH |
4126 | static int |
4127 | ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove, | |
4128 | int reset, int enable) | |
4129 | { | |
4130 | return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable); | |
4131 | } | |
4132 | ||
4133 | /** | |
4134 | * ftrace_set_filter_ip - set a function to filter on in ftrace by address | |
4135 | * @ops - the ops to set the filter with | |
4136 | * @ip - the address to add to or remove from the filter. | |
4137 | * @remove - non zero to remove the ip from the filter | |
4138 | * @reset - non zero to reset all filters before applying this filter. | |
4139 | * | |
4140 | * Filters denote which functions should be enabled when tracing is enabled | |
4141 | * If @ip is NULL, it failes to update filter. | |
4142 | */ | |
4143 | int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, | |
4144 | int remove, int reset) | |
4145 | { | |
f04f24fb | 4146 | ftrace_ops_init(ops); |
647664ea MH |
4147 | return ftrace_set_addr(ops, ip, remove, reset, 1); |
4148 | } | |
4149 | EXPORT_SYMBOL_GPL(ftrace_set_filter_ip); | |
4150 | ||
4151 | static int | |
4152 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, | |
4153 | int reset, int enable) | |
4154 | { | |
4155 | return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable); | |
4156 | } | |
4157 | ||
77a2b37d SR |
4158 | /** |
4159 | * ftrace_set_filter - set a function to filter on in ftrace | |
936e074b SR |
4160 | * @ops - the ops to set the filter with |
4161 | * @buf - the string that holds the function filter text. | |
4162 | * @len - the length of the string. | |
4163 | * @reset - non zero to reset all filters before applying this filter. | |
4164 | * | |
4165 | * Filters denote which functions should be enabled when tracing is enabled. | |
4166 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
4167 | */ | |
ac483c44 | 4168 | int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
4169 | int len, int reset) |
4170 | { | |
f04f24fb | 4171 | ftrace_ops_init(ops); |
ac483c44 | 4172 | return ftrace_set_regex(ops, buf, len, reset, 1); |
936e074b SR |
4173 | } |
4174 | EXPORT_SYMBOL_GPL(ftrace_set_filter); | |
4175 | ||
4176 | /** | |
4177 | * ftrace_set_notrace - set a function to not trace in ftrace | |
4178 | * @ops - the ops to set the notrace filter with | |
4179 | * @buf - the string that holds the function notrace text. | |
4180 | * @len - the length of the string. | |
4181 | * @reset - non zero to reset all filters before applying this filter. | |
4182 | * | |
4183 | * Notrace Filters denote which functions should not be enabled when tracing | |
4184 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
4185 | * for tracing. | |
4186 | */ | |
ac483c44 | 4187 | int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
4188 | int len, int reset) |
4189 | { | |
f04f24fb | 4190 | ftrace_ops_init(ops); |
ac483c44 | 4191 | return ftrace_set_regex(ops, buf, len, reset, 0); |
936e074b SR |
4192 | } |
4193 | EXPORT_SYMBOL_GPL(ftrace_set_notrace); | |
4194 | /** | |
8d1b065d | 4195 | * ftrace_set_global_filter - set a function to filter on with global tracers |
77a2b37d SR |
4196 | * @buf - the string that holds the function filter text. |
4197 | * @len - the length of the string. | |
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 @buf is NULL and reset is set, all functions will be enabled for tracing. | |
4202 | */ | |
936e074b | 4203 | void ftrace_set_global_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 4204 | { |
f45948e8 | 4205 | ftrace_set_regex(&global_ops, buf, len, reset, 1); |
41c52c0d | 4206 | } |
936e074b | 4207 | EXPORT_SYMBOL_GPL(ftrace_set_global_filter); |
4eebcc81 | 4208 | |
41c52c0d | 4209 | /** |
8d1b065d | 4210 | * ftrace_set_global_notrace - set a function to not trace with global tracers |
41c52c0d SR |
4211 | * @buf - the string that holds the function notrace text. |
4212 | * @len - the length of the string. | |
4213 | * @reset - non zero to reset all filters before applying this filter. | |
4214 | * | |
4215 | * Notrace Filters denote which functions should not be enabled when tracing | |
4216 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
4217 | * for tracing. | |
4218 | */ | |
936e074b | 4219 | void ftrace_set_global_notrace(unsigned char *buf, int len, int reset) |
41c52c0d | 4220 | { |
f45948e8 | 4221 | ftrace_set_regex(&global_ops, buf, len, reset, 0); |
77a2b37d | 4222 | } |
936e074b | 4223 | EXPORT_SYMBOL_GPL(ftrace_set_global_notrace); |
77a2b37d | 4224 | |
2af15d6a SR |
4225 | /* |
4226 | * command line interface to allow users to set filters on boot up. | |
4227 | */ | |
4228 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
4229 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
4230 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
4231 | ||
f1ed7c74 SRRH |
4232 | /* Used by function selftest to not test if filter is set */ |
4233 | bool ftrace_filter_param __initdata; | |
4234 | ||
2af15d6a SR |
4235 | static int __init set_ftrace_notrace(char *str) |
4236 | { | |
f1ed7c74 | 4237 | ftrace_filter_param = true; |
75761cc1 | 4238 | strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
4239 | return 1; |
4240 | } | |
4241 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
4242 | ||
4243 | static int __init set_ftrace_filter(char *str) | |
4244 | { | |
f1ed7c74 | 4245 | ftrace_filter_param = true; |
75761cc1 | 4246 | strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
4247 | return 1; |
4248 | } | |
4249 | __setup("ftrace_filter=", set_ftrace_filter); | |
4250 | ||
369bc18f | 4251 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 4252 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
0d7d9a16 | 4253 | static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata; |
faf982a6 | 4254 | static int ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer); |
801c29fd | 4255 | |
f3bea491 SRRH |
4256 | static unsigned long save_global_trampoline; |
4257 | static unsigned long save_global_flags; | |
4258 | ||
369bc18f SA |
4259 | static int __init set_graph_function(char *str) |
4260 | { | |
06f43d66 | 4261 | strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
4262 | return 1; |
4263 | } | |
4264 | __setup("ftrace_graph_filter=", set_graph_function); | |
4265 | ||
0d7d9a16 NK |
4266 | static int __init set_graph_notrace_function(char *str) |
4267 | { | |
4268 | strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE); | |
4269 | return 1; | |
4270 | } | |
4271 | __setup("ftrace_graph_notrace=", set_graph_notrace_function); | |
4272 | ||
4273 | static void __init set_ftrace_early_graph(char *buf, int enable) | |
369bc18f SA |
4274 | { |
4275 | int ret; | |
4276 | char *func; | |
0d7d9a16 NK |
4277 | unsigned long *table = ftrace_graph_funcs; |
4278 | int *count = &ftrace_graph_count; | |
4279 | ||
4280 | if (!enable) { | |
4281 | table = ftrace_graph_notrace_funcs; | |
4282 | count = &ftrace_graph_notrace_count; | |
4283 | } | |
369bc18f SA |
4284 | |
4285 | while (buf) { | |
4286 | func = strsep(&buf, ","); | |
4287 | /* we allow only one expression at a time */ | |
0d7d9a16 | 4288 | ret = ftrace_set_func(table, count, FTRACE_GRAPH_MAX_FUNCS, func); |
369bc18f SA |
4289 | if (ret) |
4290 | printk(KERN_DEBUG "ftrace: function %s not " | |
4291 | "traceable\n", func); | |
4292 | } | |
4293 | } | |
4294 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
4295 | ||
2a85a37f SR |
4296 | void __init |
4297 | ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable) | |
2af15d6a SR |
4298 | { |
4299 | char *func; | |
4300 | ||
f04f24fb MH |
4301 | ftrace_ops_init(ops); |
4302 | ||
2af15d6a SR |
4303 | while (buf) { |
4304 | func = strsep(&buf, ","); | |
f45948e8 | 4305 | ftrace_set_regex(ops, func, strlen(func), 0, enable); |
2af15d6a SR |
4306 | } |
4307 | } | |
4308 | ||
4309 | static void __init set_ftrace_early_filters(void) | |
4310 | { | |
4311 | if (ftrace_filter_buf[0]) | |
2a85a37f | 4312 | ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1); |
2af15d6a | 4313 | if (ftrace_notrace_buf[0]) |
2a85a37f | 4314 | ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0); |
369bc18f SA |
4315 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
4316 | if (ftrace_graph_buf[0]) | |
0d7d9a16 NK |
4317 | set_ftrace_early_graph(ftrace_graph_buf, 1); |
4318 | if (ftrace_graph_notrace_buf[0]) | |
4319 | set_ftrace_early_graph(ftrace_graph_notrace_buf, 0); | |
369bc18f | 4320 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
2af15d6a SR |
4321 | } |
4322 | ||
fc13cb0c | 4323 | int ftrace_regex_release(struct inode *inode, struct file *file) |
5072c59f SR |
4324 | { |
4325 | struct seq_file *m = (struct seq_file *)file->private_data; | |
7485058e | 4326 | struct ftrace_ops_hash old_hash_ops; |
5072c59f | 4327 | struct ftrace_iterator *iter; |
33dc9b12 | 4328 | struct ftrace_hash **orig_hash; |
3296fc4e | 4329 | struct ftrace_hash *old_hash; |
689fd8b6 | 4330 | struct trace_parser *parser; |
ed926f9b | 4331 | int filter_hash; |
33dc9b12 | 4332 | int ret; |
5072c59f | 4333 | |
5072c59f SR |
4334 | if (file->f_mode & FMODE_READ) { |
4335 | iter = m->private; | |
5072c59f SR |
4336 | seq_release(inode, file); |
4337 | } else | |
4338 | iter = file->private_data; | |
4339 | ||
689fd8b6 | 4340 | parser = &iter->parser; |
4341 | if (trace_parser_loaded(parser)) { | |
4342 | parser->buffer[parser->idx] = 0; | |
1cf41dd7 | 4343 | ftrace_match_records(iter->hash, parser->buffer, parser->idx); |
5072c59f SR |
4344 | } |
4345 | ||
689fd8b6 | 4346 | trace_parser_put(parser); |
689fd8b6 | 4347 | |
33b7f99c | 4348 | mutex_lock(&iter->ops->func_hash->regex_lock); |
3f2367ba | 4349 | |
058e297d | 4350 | if (file->f_mode & FMODE_WRITE) { |
ed926f9b SR |
4351 | filter_hash = !!(iter->flags & FTRACE_ITER_FILTER); |
4352 | ||
4353 | if (filter_hash) | |
33b7f99c | 4354 | orig_hash = &iter->ops->func_hash->filter_hash; |
ed926f9b | 4355 | else |
33b7f99c | 4356 | orig_hash = &iter->ops->func_hash->notrace_hash; |
33dc9b12 | 4357 | |
058e297d | 4358 | mutex_lock(&ftrace_lock); |
3296fc4e | 4359 | old_hash = *orig_hash; |
7485058e SRRH |
4360 | old_hash_ops.filter_hash = iter->ops->func_hash->filter_hash; |
4361 | old_hash_ops.notrace_hash = iter->ops->func_hash->notrace_hash; | |
41fb61c2 SR |
4362 | ret = ftrace_hash_move(iter->ops, filter_hash, |
4363 | orig_hash, iter->hash); | |
3296fc4e | 4364 | if (!ret) { |
7485058e | 4365 | ftrace_ops_update_code(iter->ops, &old_hash_ops); |
3296fc4e SRRH |
4366 | free_ftrace_hash_rcu(old_hash); |
4367 | } | |
058e297d SR |
4368 | mutex_unlock(&ftrace_lock); |
4369 | } | |
3f2367ba | 4370 | |
33b7f99c | 4371 | mutex_unlock(&iter->ops->func_hash->regex_lock); |
33dc9b12 SR |
4372 | free_ftrace_hash(iter->hash); |
4373 | kfree(iter); | |
058e297d | 4374 | |
5072c59f SR |
4375 | return 0; |
4376 | } | |
4377 | ||
5e2336a0 | 4378 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
4379 | .open = ftrace_avail_open, |
4380 | .read = seq_read, | |
4381 | .llseek = seq_lseek, | |
3be04b47 | 4382 | .release = seq_release_private, |
5072c59f SR |
4383 | }; |
4384 | ||
647bcd03 SR |
4385 | static const struct file_operations ftrace_enabled_fops = { |
4386 | .open = ftrace_enabled_open, | |
4387 | .read = seq_read, | |
4388 | .llseek = seq_lseek, | |
4389 | .release = seq_release_private, | |
4390 | }; | |
4391 | ||
5e2336a0 | 4392 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 4393 | .open = ftrace_filter_open, |
850a80cf | 4394 | .read = seq_read, |
5072c59f | 4395 | .write = ftrace_filter_write, |
098c879e | 4396 | .llseek = tracing_lseek, |
1cf41dd7 | 4397 | .release = ftrace_regex_release, |
5072c59f SR |
4398 | }; |
4399 | ||
5e2336a0 | 4400 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 4401 | .open = ftrace_notrace_open, |
850a80cf | 4402 | .read = seq_read, |
41c52c0d | 4403 | .write = ftrace_notrace_write, |
098c879e | 4404 | .llseek = tracing_lseek, |
1cf41dd7 | 4405 | .release = ftrace_regex_release, |
41c52c0d SR |
4406 | }; |
4407 | ||
ea4e2bc4 SR |
4408 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
4409 | ||
4410 | static DEFINE_MUTEX(graph_lock); | |
4411 | ||
4412 | int ftrace_graph_count; | |
29ad23b0 | 4413 | int ftrace_graph_notrace_count; |
ea4e2bc4 | 4414 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
29ad23b0 | 4415 | unsigned long ftrace_graph_notrace_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
ea4e2bc4 | 4416 | |
faf982a6 NK |
4417 | struct ftrace_graph_data { |
4418 | unsigned long *table; | |
4419 | size_t size; | |
4420 | int *count; | |
4421 | const struct seq_operations *seq_ops; | |
4422 | }; | |
4423 | ||
ea4e2bc4 | 4424 | static void * |
85951842 | 4425 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 4426 | { |
faf982a6 NK |
4427 | struct ftrace_graph_data *fgd = m->private; |
4428 | ||
4429 | if (*pos >= *fgd->count) | |
ea4e2bc4 | 4430 | return NULL; |
faf982a6 | 4431 | return &fgd->table[*pos]; |
85951842 | 4432 | } |
ea4e2bc4 | 4433 | |
85951842 LZ |
4434 | static void * |
4435 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
4436 | { | |
4437 | (*pos)++; | |
4438 | return __g_next(m, pos); | |
ea4e2bc4 SR |
4439 | } |
4440 | ||
4441 | static void *g_start(struct seq_file *m, loff_t *pos) | |
4442 | { | |
faf982a6 NK |
4443 | struct ftrace_graph_data *fgd = m->private; |
4444 | ||
ea4e2bc4 SR |
4445 | mutex_lock(&graph_lock); |
4446 | ||
f9349a8f | 4447 | /* Nothing, tell g_show to print all functions are enabled */ |
faf982a6 | 4448 | if (!*fgd->count && !*pos) |
f9349a8f FW |
4449 | return (void *)1; |
4450 | ||
85951842 | 4451 | return __g_next(m, pos); |
ea4e2bc4 SR |
4452 | } |
4453 | ||
4454 | static void g_stop(struct seq_file *m, void *p) | |
4455 | { | |
4456 | mutex_unlock(&graph_lock); | |
4457 | } | |
4458 | ||
4459 | static int g_show(struct seq_file *m, void *v) | |
4460 | { | |
4461 | unsigned long *ptr = v; | |
ea4e2bc4 SR |
4462 | |
4463 | if (!ptr) | |
4464 | return 0; | |
4465 | ||
f9349a8f | 4466 | if (ptr == (unsigned long *)1) { |
280d1429 NK |
4467 | struct ftrace_graph_data *fgd = m->private; |
4468 | ||
4469 | if (fgd->table == ftrace_graph_funcs) | |
fa6f0cc7 | 4470 | seq_puts(m, "#### all functions enabled ####\n"); |
280d1429 | 4471 | else |
fa6f0cc7 | 4472 | seq_puts(m, "#### no functions disabled ####\n"); |
f9349a8f FW |
4473 | return 0; |
4474 | } | |
4475 | ||
b375a11a | 4476 | seq_printf(m, "%ps\n", (void *)*ptr); |
ea4e2bc4 SR |
4477 | |
4478 | return 0; | |
4479 | } | |
4480 | ||
88e9d34c | 4481 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
4482 | .start = g_start, |
4483 | .next = g_next, | |
4484 | .stop = g_stop, | |
4485 | .show = g_show, | |
4486 | }; | |
4487 | ||
4488 | static int | |
faf982a6 NK |
4489 | __ftrace_graph_open(struct inode *inode, struct file *file, |
4490 | struct ftrace_graph_data *fgd) | |
ea4e2bc4 SR |
4491 | { |
4492 | int ret = 0; | |
4493 | ||
ea4e2bc4 SR |
4494 | mutex_lock(&graph_lock); |
4495 | if ((file->f_mode & FMODE_WRITE) && | |
8650ae32 | 4496 | (file->f_flags & O_TRUNC)) { |
faf982a6 NK |
4497 | *fgd->count = 0; |
4498 | memset(fgd->table, 0, fgd->size * sizeof(*fgd->table)); | |
ea4e2bc4 | 4499 | } |
a4ec5e0c | 4500 | mutex_unlock(&graph_lock); |
ea4e2bc4 | 4501 | |
faf982a6 NK |
4502 | if (file->f_mode & FMODE_READ) { |
4503 | ret = seq_open(file, fgd->seq_ops); | |
4504 | if (!ret) { | |
4505 | struct seq_file *m = file->private_data; | |
4506 | m->private = fgd; | |
4507 | } | |
4508 | } else | |
4509 | file->private_data = fgd; | |
ea4e2bc4 SR |
4510 | |
4511 | return ret; | |
4512 | } | |
4513 | ||
faf982a6 NK |
4514 | static int |
4515 | ftrace_graph_open(struct inode *inode, struct file *file) | |
4516 | { | |
4517 | struct ftrace_graph_data *fgd; | |
4518 | ||
4519 | if (unlikely(ftrace_disabled)) | |
4520 | return -ENODEV; | |
4521 | ||
4522 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
4523 | if (fgd == NULL) | |
4524 | return -ENOMEM; | |
4525 | ||
4526 | fgd->table = ftrace_graph_funcs; | |
4527 | fgd->size = FTRACE_GRAPH_MAX_FUNCS; | |
4528 | fgd->count = &ftrace_graph_count; | |
4529 | fgd->seq_ops = &ftrace_graph_seq_ops; | |
4530 | ||
4531 | return __ftrace_graph_open(inode, file, fgd); | |
4532 | } | |
4533 | ||
29ad23b0 NK |
4534 | static int |
4535 | ftrace_graph_notrace_open(struct inode *inode, struct file *file) | |
4536 | { | |
4537 | struct ftrace_graph_data *fgd; | |
4538 | ||
4539 | if (unlikely(ftrace_disabled)) | |
4540 | return -ENODEV; | |
4541 | ||
4542 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
4543 | if (fgd == NULL) | |
4544 | return -ENOMEM; | |
4545 | ||
4546 | fgd->table = ftrace_graph_notrace_funcs; | |
4547 | fgd->size = FTRACE_GRAPH_MAX_FUNCS; | |
4548 | fgd->count = &ftrace_graph_notrace_count; | |
4549 | fgd->seq_ops = &ftrace_graph_seq_ops; | |
4550 | ||
4551 | return __ftrace_graph_open(inode, file, fgd); | |
4552 | } | |
4553 | ||
87827111 LZ |
4554 | static int |
4555 | ftrace_graph_release(struct inode *inode, struct file *file) | |
4556 | { | |
faf982a6 NK |
4557 | if (file->f_mode & FMODE_READ) { |
4558 | struct seq_file *m = file->private_data; | |
4559 | ||
4560 | kfree(m->private); | |
87827111 | 4561 | seq_release(inode, file); |
faf982a6 NK |
4562 | } else { |
4563 | kfree(file->private_data); | |
4564 | } | |
4565 | ||
87827111 LZ |
4566 | return 0; |
4567 | } | |
4568 | ||
ea4e2bc4 | 4569 | static int |
faf982a6 | 4570 | ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer) |
ea4e2bc4 | 4571 | { |
ea4e2bc4 SR |
4572 | struct dyn_ftrace *rec; |
4573 | struct ftrace_page *pg; | |
f9349a8f | 4574 | int search_len; |
c7c6b1fe | 4575 | int fail = 1; |
f9349a8f FW |
4576 | int type, not; |
4577 | char *search; | |
4578 | bool exists; | |
4579 | int i; | |
ea4e2bc4 | 4580 | |
f9349a8f | 4581 | /* decode regex */ |
3f6fe06d | 4582 | type = filter_parse_regex(buffer, strlen(buffer), &search, ¬); |
faf982a6 | 4583 | if (!not && *idx >= size) |
c7c6b1fe | 4584 | return -EBUSY; |
f9349a8f FW |
4585 | |
4586 | search_len = strlen(search); | |
4587 | ||
52baf119 | 4588 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
4589 | |
4590 | if (unlikely(ftrace_disabled)) { | |
4591 | mutex_unlock(&ftrace_lock); | |
4592 | return -ENODEV; | |
4593 | } | |
4594 | ||
265c831c SR |
4595 | do_for_each_ftrace_rec(pg, rec) { |
4596 | ||
b9df92d2 | 4597 | if (ftrace_match_record(rec, NULL, search, search_len, type)) { |
c7c6b1fe | 4598 | /* if it is in the array */ |
f9349a8f | 4599 | exists = false; |
c7c6b1fe | 4600 | for (i = 0; i < *idx; i++) { |
f9349a8f FW |
4601 | if (array[i] == rec->ip) { |
4602 | exists = true; | |
265c831c SR |
4603 | break; |
4604 | } | |
c7c6b1fe LZ |
4605 | } |
4606 | ||
4607 | if (!not) { | |
4608 | fail = 0; | |
4609 | if (!exists) { | |
4610 | array[(*idx)++] = rec->ip; | |
faf982a6 | 4611 | if (*idx >= size) |
c7c6b1fe LZ |
4612 | goto out; |
4613 | } | |
4614 | } else { | |
4615 | if (exists) { | |
4616 | array[i] = array[--(*idx)]; | |
4617 | array[*idx] = 0; | |
4618 | fail = 0; | |
4619 | } | |
4620 | } | |
ea4e2bc4 | 4621 | } |
265c831c | 4622 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 4623 | out: |
52baf119 | 4624 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 4625 | |
c7c6b1fe LZ |
4626 | if (fail) |
4627 | return -EINVAL; | |
4628 | ||
c7c6b1fe | 4629 | return 0; |
ea4e2bc4 SR |
4630 | } |
4631 | ||
4632 | static ssize_t | |
4633 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
4634 | size_t cnt, loff_t *ppos) | |
4635 | { | |
689fd8b6 | 4636 | struct trace_parser parser; |
6a10108b | 4637 | ssize_t read, ret = 0; |
faf982a6 | 4638 | struct ftrace_graph_data *fgd = file->private_data; |
ea4e2bc4 | 4639 | |
c7c6b1fe | 4640 | if (!cnt) |
ea4e2bc4 SR |
4641 | return 0; |
4642 | ||
6a10108b NK |
4643 | if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) |
4644 | return -ENOMEM; | |
ea4e2bc4 | 4645 | |
689fd8b6 | 4646 | read = trace_get_user(&parser, ubuf, cnt, ppos); |
ea4e2bc4 | 4647 | |
4ba7978e | 4648 | if (read >= 0 && trace_parser_loaded((&parser))) { |
689fd8b6 | 4649 | parser.buffer[parser.idx] = 0; |
4650 | ||
6a10108b NK |
4651 | mutex_lock(&graph_lock); |
4652 | ||
689fd8b6 | 4653 | /* we allow only one expression at a time */ |
faf982a6 NK |
4654 | ret = ftrace_set_func(fgd->table, fgd->count, fgd->size, |
4655 | parser.buffer); | |
6a10108b NK |
4656 | |
4657 | mutex_unlock(&graph_lock); | |
ea4e2bc4 | 4658 | } |
ea4e2bc4 | 4659 | |
6a10108b NK |
4660 | if (!ret) |
4661 | ret = read; | |
1eb90f13 | 4662 | |
689fd8b6 | 4663 | trace_parser_put(&parser); |
ea4e2bc4 SR |
4664 | |
4665 | return ret; | |
4666 | } | |
4667 | ||
4668 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
4669 | .open = ftrace_graph_open, |
4670 | .read = seq_read, | |
4671 | .write = ftrace_graph_write, | |
098c879e | 4672 | .llseek = tracing_lseek, |
87827111 | 4673 | .release = ftrace_graph_release, |
ea4e2bc4 | 4674 | }; |
29ad23b0 NK |
4675 | |
4676 | static const struct file_operations ftrace_graph_notrace_fops = { | |
4677 | .open = ftrace_graph_notrace_open, | |
4678 | .read = seq_read, | |
4679 | .write = ftrace_graph_write, | |
098c879e | 4680 | .llseek = tracing_lseek, |
29ad23b0 NK |
4681 | .release = ftrace_graph_release, |
4682 | }; | |
ea4e2bc4 SR |
4683 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
4684 | ||
591dffda SRRH |
4685 | void ftrace_create_filter_files(struct ftrace_ops *ops, |
4686 | struct dentry *parent) | |
4687 | { | |
4688 | ||
4689 | trace_create_file("set_ftrace_filter", 0644, parent, | |
4690 | ops, &ftrace_filter_fops); | |
4691 | ||
4692 | trace_create_file("set_ftrace_notrace", 0644, parent, | |
4693 | ops, &ftrace_notrace_fops); | |
4694 | } | |
4695 | ||
4696 | /* | |
4697 | * The name "destroy_filter_files" is really a misnomer. Although | |
4698 | * in the future, it may actualy delete the files, but this is | |
4699 | * really intended to make sure the ops passed in are disabled | |
4700 | * and that when this function returns, the caller is free to | |
4701 | * free the ops. | |
4702 | * | |
4703 | * The "destroy" name is only to match the "create" name that this | |
4704 | * should be paired with. | |
4705 | */ | |
4706 | void ftrace_destroy_filter_files(struct ftrace_ops *ops) | |
4707 | { | |
4708 | mutex_lock(&ftrace_lock); | |
4709 | if (ops->flags & FTRACE_OPS_FL_ENABLED) | |
4710 | ftrace_shutdown(ops, 0); | |
4711 | ops->flags |= FTRACE_OPS_FL_DELETED; | |
4712 | mutex_unlock(&ftrace_lock); | |
4713 | } | |
4714 | ||
df4fc315 | 4715 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 4716 | { |
5072c59f | 4717 | |
5452af66 FW |
4718 | trace_create_file("available_filter_functions", 0444, |
4719 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 4720 | |
647bcd03 SR |
4721 | trace_create_file("enabled_functions", 0444, |
4722 | d_tracer, NULL, &ftrace_enabled_fops); | |
4723 | ||
591dffda | 4724 | ftrace_create_filter_files(&global_ops, d_tracer); |
ad90c0e3 | 4725 | |
ea4e2bc4 | 4726 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5452af66 | 4727 | trace_create_file("set_graph_function", 0444, d_tracer, |
ea4e2bc4 SR |
4728 | NULL, |
4729 | &ftrace_graph_fops); | |
29ad23b0 NK |
4730 | trace_create_file("set_graph_notrace", 0444, d_tracer, |
4731 | NULL, | |
4732 | &ftrace_graph_notrace_fops); | |
ea4e2bc4 SR |
4733 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
4734 | ||
5072c59f SR |
4735 | return 0; |
4736 | } | |
4737 | ||
9fd49328 | 4738 | static int ftrace_cmp_ips(const void *a, const void *b) |
68950619 | 4739 | { |
9fd49328 SR |
4740 | const unsigned long *ipa = a; |
4741 | const unsigned long *ipb = b; | |
68950619 | 4742 | |
9fd49328 SR |
4743 | if (*ipa > *ipb) |
4744 | return 1; | |
4745 | if (*ipa < *ipb) | |
4746 | return -1; | |
4747 | return 0; | |
4748 | } | |
4749 | ||
4750 | static void ftrace_swap_ips(void *a, void *b, int size) | |
4751 | { | |
4752 | unsigned long *ipa = a; | |
4753 | unsigned long *ipb = b; | |
4754 | unsigned long t; | |
4755 | ||
4756 | t = *ipa; | |
4757 | *ipa = *ipb; | |
4758 | *ipb = t; | |
68950619 SR |
4759 | } |
4760 | ||
5cb084bb | 4761 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 4762 | unsigned long *start, |
68bf21aa SR |
4763 | unsigned long *end) |
4764 | { | |
706c81f8 | 4765 | struct ftrace_page *start_pg; |
a7900875 | 4766 | struct ftrace_page *pg; |
706c81f8 | 4767 | struct dyn_ftrace *rec; |
a7900875 | 4768 | unsigned long count; |
68bf21aa SR |
4769 | unsigned long *p; |
4770 | unsigned long addr; | |
4376cac6 | 4771 | unsigned long flags = 0; /* Shut up gcc */ |
a7900875 SR |
4772 | int ret = -ENOMEM; |
4773 | ||
4774 | count = end - start; | |
4775 | ||
4776 | if (!count) | |
4777 | return 0; | |
4778 | ||
9fd49328 SR |
4779 | sort(start, count, sizeof(*start), |
4780 | ftrace_cmp_ips, ftrace_swap_ips); | |
4781 | ||
706c81f8 SR |
4782 | start_pg = ftrace_allocate_pages(count); |
4783 | if (!start_pg) | |
a7900875 | 4784 | return -ENOMEM; |
68bf21aa | 4785 | |
e6ea44e9 | 4786 | mutex_lock(&ftrace_lock); |
a7900875 | 4787 | |
32082309 SR |
4788 | /* |
4789 | * Core and each module needs their own pages, as | |
4790 | * modules will free them when they are removed. | |
4791 | * Force a new page to be allocated for modules. | |
4792 | */ | |
a7900875 SR |
4793 | if (!mod) { |
4794 | WARN_ON(ftrace_pages || ftrace_pages_start); | |
4795 | /* First initialization */ | |
706c81f8 | 4796 | ftrace_pages = ftrace_pages_start = start_pg; |
a7900875 | 4797 | } else { |
32082309 | 4798 | if (!ftrace_pages) |
a7900875 | 4799 | goto out; |
32082309 | 4800 | |
a7900875 SR |
4801 | if (WARN_ON(ftrace_pages->next)) { |
4802 | /* Hmm, we have free pages? */ | |
4803 | while (ftrace_pages->next) | |
4804 | ftrace_pages = ftrace_pages->next; | |
32082309 | 4805 | } |
a7900875 | 4806 | |
706c81f8 | 4807 | ftrace_pages->next = start_pg; |
32082309 SR |
4808 | } |
4809 | ||
68bf21aa | 4810 | p = start; |
706c81f8 | 4811 | pg = start_pg; |
68bf21aa SR |
4812 | while (p < end) { |
4813 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
4814 | /* |
4815 | * Some architecture linkers will pad between | |
4816 | * the different mcount_loc sections of different | |
4817 | * object files to satisfy alignments. | |
4818 | * Skip any NULL pointers. | |
4819 | */ | |
4820 | if (!addr) | |
4821 | continue; | |
706c81f8 SR |
4822 | |
4823 | if (pg->index == pg->size) { | |
4824 | /* We should have allocated enough */ | |
4825 | if (WARN_ON(!pg->next)) | |
4826 | break; | |
4827 | pg = pg->next; | |
4828 | } | |
4829 | ||
4830 | rec = &pg->records[pg->index++]; | |
4831 | rec->ip = addr; | |
68bf21aa SR |
4832 | } |
4833 | ||
706c81f8 SR |
4834 | /* We should have used all pages */ |
4835 | WARN_ON(pg->next); | |
4836 | ||
4837 | /* Assign the last page to ftrace_pages */ | |
4838 | ftrace_pages = pg; | |
4839 | ||
a4f18ed1 | 4840 | /* |
4376cac6 SR |
4841 | * We only need to disable interrupts on start up |
4842 | * because we are modifying code that an interrupt | |
4843 | * may execute, and the modification is not atomic. | |
4844 | * But for modules, nothing runs the code we modify | |
4845 | * until we are finished with it, and there's no | |
4846 | * reason to cause large interrupt latencies while we do it. | |
a4f18ed1 | 4847 | */ |
4376cac6 SR |
4848 | if (!mod) |
4849 | local_irq_save(flags); | |
1dc43cf0 | 4850 | ftrace_update_code(mod, start_pg); |
4376cac6 SR |
4851 | if (!mod) |
4852 | local_irq_restore(flags); | |
a7900875 SR |
4853 | ret = 0; |
4854 | out: | |
e6ea44e9 | 4855 | mutex_unlock(&ftrace_lock); |
68bf21aa | 4856 | |
a7900875 | 4857 | return ret; |
68bf21aa SR |
4858 | } |
4859 | ||
93eb677d | 4860 | #ifdef CONFIG_MODULES |
32082309 SR |
4861 | |
4862 | #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next) | |
4863 | ||
e7247a15 | 4864 | void ftrace_release_mod(struct module *mod) |
93eb677d SR |
4865 | { |
4866 | struct dyn_ftrace *rec; | |
32082309 | 4867 | struct ftrace_page **last_pg; |
93eb677d | 4868 | struct ftrace_page *pg; |
a7900875 | 4869 | int order; |
93eb677d | 4870 | |
45a4a237 SR |
4871 | mutex_lock(&ftrace_lock); |
4872 | ||
e7247a15 | 4873 | if (ftrace_disabled) |
45a4a237 | 4874 | goto out_unlock; |
93eb677d | 4875 | |
32082309 SR |
4876 | /* |
4877 | * Each module has its own ftrace_pages, remove | |
4878 | * them from the list. | |
4879 | */ | |
4880 | last_pg = &ftrace_pages_start; | |
4881 | for (pg = ftrace_pages_start; pg; pg = *last_pg) { | |
4882 | rec = &pg->records[0]; | |
e7247a15 | 4883 | if (within_module_core(rec->ip, mod)) { |
93eb677d | 4884 | /* |
32082309 SR |
4885 | * As core pages are first, the first |
4886 | * page should never be a module page. | |
93eb677d | 4887 | */ |
32082309 SR |
4888 | if (WARN_ON(pg == ftrace_pages_start)) |
4889 | goto out_unlock; | |
4890 | ||
4891 | /* Check if we are deleting the last page */ | |
4892 | if (pg == ftrace_pages) | |
4893 | ftrace_pages = next_to_ftrace_page(last_pg); | |
4894 | ||
4895 | *last_pg = pg->next; | |
a7900875 SR |
4896 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
4897 | free_pages((unsigned long)pg->records, order); | |
4898 | kfree(pg); | |
32082309 SR |
4899 | } else |
4900 | last_pg = &pg->next; | |
4901 | } | |
45a4a237 | 4902 | out_unlock: |
93eb677d SR |
4903 | mutex_unlock(&ftrace_lock); |
4904 | } | |
4905 | ||
4906 | static void ftrace_init_module(struct module *mod, | |
4907 | unsigned long *start, unsigned long *end) | |
90d595fe | 4908 | { |
00fd61ae | 4909 | if (ftrace_disabled || start == end) |
fed1939c | 4910 | return; |
5cb084bb | 4911 | ftrace_process_locs(mod, start, end); |
90d595fe SR |
4912 | } |
4913 | ||
a949ae56 | 4914 | void ftrace_module_init(struct module *mod) |
93eb677d | 4915 | { |
a949ae56 SRRH |
4916 | ftrace_init_module(mod, mod->ftrace_callsites, |
4917 | mod->ftrace_callsites + | |
4918 | mod->num_ftrace_callsites); | |
8c189ea6 SRRH |
4919 | } |
4920 | ||
4921 | static int ftrace_module_notify_exit(struct notifier_block *self, | |
4922 | unsigned long val, void *data) | |
4923 | { | |
4924 | struct module *mod = data; | |
4925 | ||
4926 | if (val == MODULE_STATE_GOING) | |
e7247a15 | 4927 | ftrace_release_mod(mod); |
93eb677d SR |
4928 | |
4929 | return 0; | |
4930 | } | |
4931 | #else | |
8c189ea6 SRRH |
4932 | static int ftrace_module_notify_exit(struct notifier_block *self, |
4933 | unsigned long val, void *data) | |
93eb677d SR |
4934 | { |
4935 | return 0; | |
4936 | } | |
4937 | #endif /* CONFIG_MODULES */ | |
4938 | ||
8c189ea6 SRRH |
4939 | struct notifier_block ftrace_module_exit_nb = { |
4940 | .notifier_call = ftrace_module_notify_exit, | |
4941 | .priority = INT_MIN, /* Run after anything that can remove kprobes */ | |
4942 | }; | |
4943 | ||
68bf21aa SR |
4944 | void __init ftrace_init(void) |
4945 | { | |
1dc43cf0 JS |
4946 | extern unsigned long __start_mcount_loc[]; |
4947 | extern unsigned long __stop_mcount_loc[]; | |
3a36cb11 | 4948 | unsigned long count, flags; |
68bf21aa SR |
4949 | int ret; |
4950 | ||
68bf21aa | 4951 | local_irq_save(flags); |
3a36cb11 | 4952 | ret = ftrace_dyn_arch_init(); |
68bf21aa | 4953 | local_irq_restore(flags); |
af64a7cb | 4954 | if (ret) |
68bf21aa SR |
4955 | goto failed; |
4956 | ||
4957 | count = __stop_mcount_loc - __start_mcount_loc; | |
c867ccd8 JS |
4958 | if (!count) { |
4959 | pr_info("ftrace: No functions to be traced?\n"); | |
68bf21aa | 4960 | goto failed; |
c867ccd8 JS |
4961 | } |
4962 | ||
4963 | pr_info("ftrace: allocating %ld entries in %ld pages\n", | |
4964 | count, count / ENTRIES_PER_PAGE + 1); | |
68bf21aa SR |
4965 | |
4966 | last_ftrace_enabled = ftrace_enabled = 1; | |
4967 | ||
5cb084bb | 4968 | ret = ftrace_process_locs(NULL, |
31e88909 | 4969 | __start_mcount_loc, |
68bf21aa SR |
4970 | __stop_mcount_loc); |
4971 | ||
8c189ea6 | 4972 | ret = register_module_notifier(&ftrace_module_exit_nb); |
24ed0c4b | 4973 | if (ret) |
8c189ea6 | 4974 | pr_warning("Failed to register trace ftrace module exit notifier\n"); |
93eb677d | 4975 | |
2af15d6a SR |
4976 | set_ftrace_early_filters(); |
4977 | ||
68bf21aa SR |
4978 | return; |
4979 | failed: | |
4980 | ftrace_disabled = 1; | |
4981 | } | |
68bf21aa | 4982 | |
f3bea491 SRRH |
4983 | /* Do nothing if arch does not support this */ |
4984 | void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops) | |
4985 | { | |
4986 | } | |
4987 | ||
4988 | static void ftrace_update_trampoline(struct ftrace_ops *ops) | |
4989 | { | |
12cce594 SRRH |
4990 | |
4991 | /* | |
4992 | * Currently there's no safe way to free a trampoline when the kernel | |
4993 | * is configured with PREEMPT. That is because a task could be preempted | |
4994 | * when it jumped to the trampoline, it may be preempted for a long time | |
4995 | * depending on the system load, and currently there's no way to know | |
4996 | * when it will be off the trampoline. If the trampoline is freed | |
4997 | * too early, when the task runs again, it will be executing on freed | |
4998 | * memory and crash. | |
4999 | */ | |
5000 | #ifdef CONFIG_PREEMPT | |
f3bea491 SRRH |
5001 | /* Currently, only non dynamic ops can have a trampoline */ |
5002 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC) | |
5003 | return; | |
12cce594 | 5004 | #endif |
f3bea491 SRRH |
5005 | |
5006 | arch_ftrace_update_trampoline(ops); | |
5007 | } | |
5008 | ||
3d083395 | 5009 | #else |
0b6e4d56 | 5010 | |
2b499381 | 5011 | static struct ftrace_ops global_ops = { |
bd69c30b | 5012 | .func = ftrace_stub, |
f04f24fb | 5013 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, |
bd69c30b SR |
5014 | }; |
5015 | ||
0b6e4d56 FW |
5016 | static int __init ftrace_nodyn_init(void) |
5017 | { | |
5018 | ftrace_enabled = 1; | |
5019 | return 0; | |
5020 | } | |
6f415672 | 5021 | core_initcall(ftrace_nodyn_init); |
0b6e4d56 | 5022 | |
df4fc315 SR |
5023 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
5024 | static inline void ftrace_startup_enable(int command) { } | |
e1effa01 | 5025 | static inline void ftrace_startup_all(int command) { } |
5a45cfe1 | 5026 | /* Keep as macros so we do not need to define the commands */ |
8a56d776 SRRH |
5027 | # define ftrace_startup(ops, command) \ |
5028 | ({ \ | |
5029 | int ___ret = __register_ftrace_function(ops); \ | |
5030 | if (!___ret) \ | |
5031 | (ops)->flags |= FTRACE_OPS_FL_ENABLED; \ | |
5032 | ___ret; \ | |
3b6cfdb1 | 5033 | }) |
1fcc1553 SRRH |
5034 | # define ftrace_shutdown(ops, command) \ |
5035 | ({ \ | |
5036 | int ___ret = __unregister_ftrace_function(ops); \ | |
5037 | if (!___ret) \ | |
5038 | (ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \ | |
5039 | ___ret; \ | |
5040 | }) | |
8a56d776 | 5041 | |
c7aafc54 IM |
5042 | # define ftrace_startup_sysctl() do { } while (0) |
5043 | # define ftrace_shutdown_sysctl() do { } while (0) | |
b848914c SR |
5044 | |
5045 | static inline int | |
195a8afc | 5046 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
b848914c SR |
5047 | { |
5048 | return 1; | |
5049 | } | |
5050 | ||
f3bea491 SRRH |
5051 | static void ftrace_update_trampoline(struct ftrace_ops *ops) |
5052 | { | |
5053 | } | |
5054 | ||
3d083395 SR |
5055 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
5056 | ||
4104d326 SRRH |
5057 | __init void ftrace_init_global_array_ops(struct trace_array *tr) |
5058 | { | |
5059 | tr->ops = &global_ops; | |
5060 | tr->ops->private = tr; | |
5061 | } | |
5062 | ||
5063 | void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func) | |
5064 | { | |
5065 | /* If we filter on pids, update to use the pid function */ | |
5066 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL) { | |
5067 | if (WARN_ON(tr->ops->func != ftrace_stub)) | |
5068 | printk("ftrace ops had %pS for function\n", | |
5069 | tr->ops->func); | |
5070 | /* Only the top level instance does pid tracing */ | |
5071 | if (!list_empty(&ftrace_pids)) { | |
5072 | set_ftrace_pid_function(func); | |
5073 | func = ftrace_pid_func; | |
5074 | } | |
5075 | } | |
5076 | tr->ops->func = func; | |
5077 | tr->ops->private = tr; | |
5078 | } | |
5079 | ||
5080 | void ftrace_reset_array_ops(struct trace_array *tr) | |
5081 | { | |
5082 | tr->ops->func = ftrace_stub; | |
5083 | } | |
5084 | ||
e248491a | 5085 | static void |
2f5f6ad9 | 5086 | ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 5087 | struct ftrace_ops *op, struct pt_regs *regs) |
e248491a | 5088 | { |
e248491a JO |
5089 | if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT))) |
5090 | return; | |
5091 | ||
5092 | /* | |
5093 | * Some of the ops may be dynamically allocated, | |
5094 | * they must be freed after a synchronize_sched(). | |
5095 | */ | |
5096 | preempt_disable_notrace(); | |
5097 | trace_recursion_set(TRACE_CONTROL_BIT); | |
b5aa3a47 SRRH |
5098 | |
5099 | /* | |
5100 | * Control funcs (perf) uses RCU. Only trace if | |
5101 | * RCU is currently active. | |
5102 | */ | |
5103 | if (!rcu_is_watching()) | |
5104 | goto out; | |
5105 | ||
0a016409 | 5106 | do_for_each_ftrace_op(op, ftrace_control_list) { |
395b97a3 SRRH |
5107 | if (!(op->flags & FTRACE_OPS_FL_STUB) && |
5108 | !ftrace_function_local_disabled(op) && | |
195a8afc | 5109 | ftrace_ops_test(op, ip, regs)) |
a1e2e31d | 5110 | op->func(ip, parent_ip, op, regs); |
0a016409 | 5111 | } while_for_each_ftrace_op(op); |
b5aa3a47 | 5112 | out: |
e248491a JO |
5113 | trace_recursion_clear(TRACE_CONTROL_BIT); |
5114 | preempt_enable_notrace(); | |
5115 | } | |
5116 | ||
5117 | static struct ftrace_ops control_ops = { | |
f04f24fb MH |
5118 | .func = ftrace_ops_control_func, |
5119 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, | |
33b7f99c | 5120 | INIT_OPS_HASH(control_ops) |
e248491a JO |
5121 | }; |
5122 | ||
2f5f6ad9 SR |
5123 | static inline void |
5124 | __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 5125 | struct ftrace_ops *ignored, struct pt_regs *regs) |
b848914c | 5126 | { |
cdbe61bf | 5127 | struct ftrace_ops *op; |
edc15caf | 5128 | int bit; |
b848914c | 5129 | |
edc15caf SR |
5130 | bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX); |
5131 | if (bit < 0) | |
5132 | return; | |
b1cff0ad | 5133 | |
cdbe61bf SR |
5134 | /* |
5135 | * Some of the ops may be dynamically allocated, | |
5136 | * they must be freed after a synchronize_sched(). | |
5137 | */ | |
5138 | preempt_disable_notrace(); | |
0a016409 | 5139 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
4104d326 | 5140 | if (ftrace_ops_test(op, ip, regs)) { |
1d48d596 SRRH |
5141 | if (FTRACE_WARN_ON(!op->func)) { |
5142 | pr_warn("op=%p %pS\n", op, op); | |
4104d326 SRRH |
5143 | goto out; |
5144 | } | |
a1e2e31d | 5145 | op->func(ip, parent_ip, op, regs); |
4104d326 | 5146 | } |
0a016409 | 5147 | } while_for_each_ftrace_op(op); |
4104d326 | 5148 | out: |
cdbe61bf | 5149 | preempt_enable_notrace(); |
edc15caf | 5150 | trace_clear_recursion(bit); |
b848914c SR |
5151 | } |
5152 | ||
2f5f6ad9 SR |
5153 | /* |
5154 | * Some archs only support passing ip and parent_ip. Even though | |
5155 | * the list function ignores the op parameter, we do not want any | |
5156 | * C side effects, where a function is called without the caller | |
5157 | * sending a third parameter. | |
a1e2e31d SR |
5158 | * Archs are to support both the regs and ftrace_ops at the same time. |
5159 | * If they support ftrace_ops, it is assumed they support regs. | |
5160 | * If call backs want to use regs, they must either check for regs | |
06aeaaea MH |
5161 | * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS. |
5162 | * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved. | |
a1e2e31d SR |
5163 | * An architecture can pass partial regs with ftrace_ops and still |
5164 | * set the ARCH_SUPPORT_FTARCE_OPS. | |
2f5f6ad9 SR |
5165 | */ |
5166 | #if ARCH_SUPPORTS_FTRACE_OPS | |
5167 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 5168 | struct ftrace_ops *op, struct pt_regs *regs) |
2f5f6ad9 | 5169 | { |
a1e2e31d | 5170 | __ftrace_ops_list_func(ip, parent_ip, NULL, regs); |
2f5f6ad9 SR |
5171 | } |
5172 | #else | |
5173 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip) | |
5174 | { | |
a1e2e31d | 5175 | __ftrace_ops_list_func(ip, parent_ip, NULL, NULL); |
2f5f6ad9 SR |
5176 | } |
5177 | #endif | |
5178 | ||
f1ff6348 SRRH |
5179 | /* |
5180 | * If there's only one function registered but it does not support | |
5181 | * recursion, this function will be called by the mcount trampoline. | |
5182 | * This function will handle recursion protection. | |
5183 | */ | |
5184 | static void ftrace_ops_recurs_func(unsigned long ip, unsigned long parent_ip, | |
5185 | struct ftrace_ops *op, struct pt_regs *regs) | |
5186 | { | |
5187 | int bit; | |
5188 | ||
5189 | bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX); | |
5190 | if (bit < 0) | |
5191 | return; | |
5192 | ||
5193 | op->func(ip, parent_ip, op, regs); | |
5194 | ||
5195 | trace_clear_recursion(bit); | |
5196 | } | |
5197 | ||
87354059 SRRH |
5198 | /** |
5199 | * ftrace_ops_get_func - get the function a trampoline should call | |
5200 | * @ops: the ops to get the function for | |
5201 | * | |
5202 | * Normally the mcount trampoline will call the ops->func, but there | |
5203 | * are times that it should not. For example, if the ops does not | |
5204 | * have its own recursion protection, then it should call the | |
5205 | * ftrace_ops_recurs_func() instead. | |
5206 | * | |
5207 | * Returns the function that the trampoline should call for @ops. | |
5208 | */ | |
5209 | ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops) | |
5210 | { | |
5211 | /* | |
5212 | * If this is a dynamic ops or we force list func, | |
5213 | * then it needs to call the list anyway. | |
5214 | */ | |
5215 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC || FTRACE_FORCE_LIST_FUNC) | |
5216 | return ftrace_ops_list_func; | |
5217 | ||
5218 | /* | |
5219 | * If the func handles its own recursion, call it directly. | |
5220 | * Otherwise call the recursion protected function that | |
5221 | * will call the ftrace ops function. | |
5222 | */ | |
5223 | if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE)) | |
5224 | return ftrace_ops_recurs_func; | |
5225 | ||
5226 | return ops->func; | |
5227 | } | |
5228 | ||
e32d8956 | 5229 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
5230 | { |
5231 | struct task_struct *p; | |
e32d8956 | 5232 | int cpu; |
978f3a45 | 5233 | |
e32d8956 SR |
5234 | get_online_cpus(); |
5235 | for_each_online_cpu(cpu) { | |
5236 | p = idle_task(cpu); | |
978f3a45 | 5237 | clear_tsk_trace_trace(p); |
e32d8956 SR |
5238 | } |
5239 | put_online_cpus(); | |
5240 | } | |
978f3a45 | 5241 | |
e32d8956 SR |
5242 | static void set_ftrace_swapper(void) |
5243 | { | |
5244 | struct task_struct *p; | |
5245 | int cpu; | |
5246 | ||
5247 | get_online_cpus(); | |
5248 | for_each_online_cpu(cpu) { | |
5249 | p = idle_task(cpu); | |
5250 | set_tsk_trace_trace(p); | |
5251 | } | |
5252 | put_online_cpus(); | |
978f3a45 SR |
5253 | } |
5254 | ||
e32d8956 SR |
5255 | static void clear_ftrace_pid(struct pid *pid) |
5256 | { | |
5257 | struct task_struct *p; | |
5258 | ||
229c4ef8 | 5259 | rcu_read_lock(); |
e32d8956 SR |
5260 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
5261 | clear_tsk_trace_trace(p); | |
5262 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
5263 | rcu_read_unlock(); |
5264 | ||
e32d8956 SR |
5265 | put_pid(pid); |
5266 | } | |
5267 | ||
5268 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
5269 | { |
5270 | struct task_struct *p; | |
5271 | ||
229c4ef8 | 5272 | rcu_read_lock(); |
978f3a45 SR |
5273 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
5274 | set_tsk_trace_trace(p); | |
5275 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 5276 | rcu_read_unlock(); |
978f3a45 SR |
5277 | } |
5278 | ||
756d17ee | 5279 | static void clear_ftrace_pid_task(struct pid *pid) |
e32d8956 | 5280 | { |
756d17ee | 5281 | if (pid == ftrace_swapper_pid) |
e32d8956 SR |
5282 | clear_ftrace_swapper(); |
5283 | else | |
756d17ee | 5284 | clear_ftrace_pid(pid); |
e32d8956 SR |
5285 | } |
5286 | ||
5287 | static void set_ftrace_pid_task(struct pid *pid) | |
5288 | { | |
5289 | if (pid == ftrace_swapper_pid) | |
5290 | set_ftrace_swapper(); | |
5291 | else | |
5292 | set_ftrace_pid(pid); | |
5293 | } | |
5294 | ||
756d17ee | 5295 | static int ftrace_pid_add(int p) |
df4fc315 | 5296 | { |
978f3a45 | 5297 | struct pid *pid; |
756d17ee | 5298 | struct ftrace_pid *fpid; |
5299 | int ret = -EINVAL; | |
df4fc315 | 5300 | |
756d17ee | 5301 | mutex_lock(&ftrace_lock); |
df4fc315 | 5302 | |
756d17ee | 5303 | if (!p) |
5304 | pid = ftrace_swapper_pid; | |
5305 | else | |
5306 | pid = find_get_pid(p); | |
df4fc315 | 5307 | |
756d17ee | 5308 | if (!pid) |
5309 | goto out; | |
df4fc315 | 5310 | |
756d17ee | 5311 | ret = 0; |
df4fc315 | 5312 | |
756d17ee | 5313 | list_for_each_entry(fpid, &ftrace_pids, list) |
5314 | if (fpid->pid == pid) | |
5315 | goto out_put; | |
978f3a45 | 5316 | |
756d17ee | 5317 | ret = -ENOMEM; |
df4fc315 | 5318 | |
756d17ee | 5319 | fpid = kmalloc(sizeof(*fpid), GFP_KERNEL); |
5320 | if (!fpid) | |
5321 | goto out_put; | |
df4fc315 | 5322 | |
756d17ee | 5323 | list_add(&fpid->list, &ftrace_pids); |
5324 | fpid->pid = pid; | |
0ef8cde5 | 5325 | |
756d17ee | 5326 | set_ftrace_pid_task(pid); |
978f3a45 | 5327 | |
756d17ee | 5328 | ftrace_update_pid_func(); |
e1effa01 SRRH |
5329 | |
5330 | ftrace_startup_all(0); | |
756d17ee | 5331 | |
5332 | mutex_unlock(&ftrace_lock); | |
5333 | return 0; | |
5334 | ||
5335 | out_put: | |
5336 | if (pid != ftrace_swapper_pid) | |
5337 | put_pid(pid); | |
978f3a45 | 5338 | |
756d17ee | 5339 | out: |
5340 | mutex_unlock(&ftrace_lock); | |
5341 | return ret; | |
5342 | } | |
5343 | ||
5344 | static void ftrace_pid_reset(void) | |
5345 | { | |
5346 | struct ftrace_pid *fpid, *safe; | |
978f3a45 | 5347 | |
756d17ee | 5348 | mutex_lock(&ftrace_lock); |
5349 | list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) { | |
5350 | struct pid *pid = fpid->pid; | |
5351 | ||
5352 | clear_ftrace_pid_task(pid); | |
5353 | ||
5354 | list_del(&fpid->list); | |
5355 | kfree(fpid); | |
df4fc315 SR |
5356 | } |
5357 | ||
df4fc315 | 5358 | ftrace_update_pid_func(); |
e1effa01 | 5359 | ftrace_startup_all(0); |
df4fc315 | 5360 | |
e6ea44e9 | 5361 | mutex_unlock(&ftrace_lock); |
756d17ee | 5362 | } |
df4fc315 | 5363 | |
756d17ee | 5364 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
5365 | { | |
5366 | mutex_lock(&ftrace_lock); | |
5367 | ||
5368 | if (list_empty(&ftrace_pids) && (!*pos)) | |
5369 | return (void *) 1; | |
5370 | ||
5371 | return seq_list_start(&ftrace_pids, *pos); | |
5372 | } | |
5373 | ||
5374 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
5375 | { | |
5376 | if (v == (void *)1) | |
5377 | return NULL; | |
5378 | ||
5379 | return seq_list_next(v, &ftrace_pids, pos); | |
5380 | } | |
5381 | ||
5382 | static void fpid_stop(struct seq_file *m, void *p) | |
5383 | { | |
5384 | mutex_unlock(&ftrace_lock); | |
5385 | } | |
5386 | ||
5387 | static int fpid_show(struct seq_file *m, void *v) | |
5388 | { | |
5389 | const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list); | |
5390 | ||
5391 | if (v == (void *)1) { | |
fa6f0cc7 | 5392 | seq_puts(m, "no pid\n"); |
756d17ee | 5393 | return 0; |
5394 | } | |
5395 | ||
5396 | if (fpid->pid == ftrace_swapper_pid) | |
fa6f0cc7 | 5397 | seq_puts(m, "swapper tasks\n"); |
756d17ee | 5398 | else |
5399 | seq_printf(m, "%u\n", pid_vnr(fpid->pid)); | |
5400 | ||
5401 | return 0; | |
5402 | } | |
5403 | ||
5404 | static const struct seq_operations ftrace_pid_sops = { | |
5405 | .start = fpid_start, | |
5406 | .next = fpid_next, | |
5407 | .stop = fpid_stop, | |
5408 | .show = fpid_show, | |
5409 | }; | |
5410 | ||
5411 | static int | |
5412 | ftrace_pid_open(struct inode *inode, struct file *file) | |
5413 | { | |
5414 | int ret = 0; | |
5415 | ||
5416 | if ((file->f_mode & FMODE_WRITE) && | |
5417 | (file->f_flags & O_TRUNC)) | |
5418 | ftrace_pid_reset(); | |
5419 | ||
5420 | if (file->f_mode & FMODE_READ) | |
5421 | ret = seq_open(file, &ftrace_pid_sops); | |
5422 | ||
5423 | return ret; | |
5424 | } | |
5425 | ||
df4fc315 SR |
5426 | static ssize_t |
5427 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
5428 | size_t cnt, loff_t *ppos) | |
5429 | { | |
457dc928 | 5430 | char buf[64], *tmp; |
df4fc315 SR |
5431 | long val; |
5432 | int ret; | |
5433 | ||
5434 | if (cnt >= sizeof(buf)) | |
5435 | return -EINVAL; | |
5436 | ||
5437 | if (copy_from_user(&buf, ubuf, cnt)) | |
5438 | return -EFAULT; | |
5439 | ||
5440 | buf[cnt] = 0; | |
5441 | ||
756d17ee | 5442 | /* |
5443 | * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid" | |
5444 | * to clean the filter quietly. | |
5445 | */ | |
457dc928 IM |
5446 | tmp = strstrip(buf); |
5447 | if (strlen(tmp) == 0) | |
756d17ee | 5448 | return 1; |
5449 | ||
bcd83ea6 | 5450 | ret = kstrtol(tmp, 10, &val); |
df4fc315 SR |
5451 | if (ret < 0) |
5452 | return ret; | |
5453 | ||
756d17ee | 5454 | ret = ftrace_pid_add(val); |
df4fc315 | 5455 | |
756d17ee | 5456 | return ret ? ret : cnt; |
5457 | } | |
df4fc315 | 5458 | |
756d17ee | 5459 | static int |
5460 | ftrace_pid_release(struct inode *inode, struct file *file) | |
5461 | { | |
5462 | if (file->f_mode & FMODE_READ) | |
5463 | seq_release(inode, file); | |
df4fc315 | 5464 | |
756d17ee | 5465 | return 0; |
df4fc315 SR |
5466 | } |
5467 | ||
5e2336a0 | 5468 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 5469 | .open = ftrace_pid_open, |
5470 | .write = ftrace_pid_write, | |
5471 | .read = seq_read, | |
098c879e | 5472 | .llseek = tracing_lseek, |
756d17ee | 5473 | .release = ftrace_pid_release, |
df4fc315 SR |
5474 | }; |
5475 | ||
5476 | static __init int ftrace_init_debugfs(void) | |
5477 | { | |
5478 | struct dentry *d_tracer; | |
df4fc315 SR |
5479 | |
5480 | d_tracer = tracing_init_dentry(); | |
14a5ae40 | 5481 | if (IS_ERR(d_tracer)) |
df4fc315 SR |
5482 | return 0; |
5483 | ||
5484 | ftrace_init_dyn_debugfs(d_tracer); | |
5485 | ||
5452af66 FW |
5486 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
5487 | NULL, &ftrace_pid_fops); | |
493762fc SR |
5488 | |
5489 | ftrace_profile_debugfs(d_tracer); | |
5490 | ||
df4fc315 SR |
5491 | return 0; |
5492 | } | |
df4fc315 SR |
5493 | fs_initcall(ftrace_init_debugfs); |
5494 | ||
a2bb6a3d | 5495 | /** |
81adbdc0 | 5496 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
5497 | * |
5498 | * This function should be used by panic code. It stops ftrace | |
5499 | * but in a not so nice way. If you need to simply kill ftrace | |
5500 | * from a non-atomic section, use ftrace_kill. | |
5501 | */ | |
81adbdc0 | 5502 | void ftrace_kill(void) |
a2bb6a3d SR |
5503 | { |
5504 | ftrace_disabled = 1; | |
5505 | ftrace_enabled = 0; | |
a2bb6a3d SR |
5506 | clear_ftrace_function(); |
5507 | } | |
5508 | ||
e0a413f6 SR |
5509 | /** |
5510 | * Test if ftrace is dead or not. | |
5511 | */ | |
5512 | int ftrace_is_dead(void) | |
5513 | { | |
5514 | return ftrace_disabled; | |
5515 | } | |
5516 | ||
16444a8a | 5517 | /** |
3d083395 SR |
5518 | * register_ftrace_function - register a function for profiling |
5519 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 5520 | * |
3d083395 SR |
5521 | * Register a function to be called by all functions in the |
5522 | * kernel. | |
5523 | * | |
5524 | * Note: @ops->func and all the functions it calls must be labeled | |
5525 | * with "notrace", otherwise it will go into a | |
5526 | * recursive loop. | |
16444a8a | 5527 | */ |
3d083395 | 5528 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 5529 | { |
45a4a237 | 5530 | int ret = -1; |
4eebcc81 | 5531 | |
f04f24fb MH |
5532 | ftrace_ops_init(ops); |
5533 | ||
e6ea44e9 | 5534 | mutex_lock(&ftrace_lock); |
e7d3737e | 5535 | |
8a56d776 | 5536 | ret = ftrace_startup(ops, 0); |
b848914c | 5537 | |
e6ea44e9 | 5538 | mutex_unlock(&ftrace_lock); |
8d240dd8 | 5539 | |
b0fc494f | 5540 | return ret; |
3d083395 | 5541 | } |
cdbe61bf | 5542 | EXPORT_SYMBOL_GPL(register_ftrace_function); |
3d083395 SR |
5543 | |
5544 | /** | |
32632920 | 5545 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
5546 | * @ops - ops structure that holds the function to unregister |
5547 | * | |
5548 | * Unregister a function that was added to be called by ftrace profiling. | |
5549 | */ | |
5550 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
5551 | { | |
5552 | int ret; | |
5553 | ||
e6ea44e9 | 5554 | mutex_lock(&ftrace_lock); |
8a56d776 | 5555 | ret = ftrace_shutdown(ops, 0); |
e6ea44e9 | 5556 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
5557 | |
5558 | return ret; | |
5559 | } | |
cdbe61bf | 5560 | EXPORT_SYMBOL_GPL(unregister_ftrace_function); |
b0fc494f | 5561 | |
e309b41d | 5562 | int |
b0fc494f | 5563 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
8d65af78 | 5564 | void __user *buffer, size_t *lenp, |
b0fc494f SR |
5565 | loff_t *ppos) |
5566 | { | |
45a4a237 | 5567 | int ret = -ENODEV; |
4eebcc81 | 5568 | |
e6ea44e9 | 5569 | mutex_lock(&ftrace_lock); |
b0fc494f | 5570 | |
45a4a237 SR |
5571 | if (unlikely(ftrace_disabled)) |
5572 | goto out; | |
5573 | ||
5574 | ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
b0fc494f | 5575 | |
a32c7765 | 5576 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
5577 | goto out; |
5578 | ||
a32c7765 | 5579 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f SR |
5580 | |
5581 | if (ftrace_enabled) { | |
5582 | ||
5583 | ftrace_startup_sysctl(); | |
5584 | ||
5585 | /* we are starting ftrace again */ | |
5000c418 JK |
5586 | if (ftrace_ops_list != &ftrace_list_end) |
5587 | update_ftrace_function(); | |
b0fc494f SR |
5588 | |
5589 | } else { | |
5590 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
5591 | ftrace_trace_function = ftrace_stub; | |
5592 | ||
5593 | ftrace_shutdown_sysctl(); | |
5594 | } | |
5595 | ||
5596 | out: | |
e6ea44e9 | 5597 | mutex_unlock(&ftrace_lock); |
3d083395 | 5598 | return ret; |
16444a8a | 5599 | } |
f17845e5 | 5600 | |
fb52607a | 5601 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 5602 | |
5f151b24 SRRH |
5603 | static struct ftrace_ops graph_ops = { |
5604 | .func = ftrace_stub, | |
5605 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | | |
5606 | FTRACE_OPS_FL_INITIALIZED | | |
5607 | FTRACE_OPS_FL_STUB, | |
5608 | #ifdef FTRACE_GRAPH_TRAMP_ADDR | |
5609 | .trampoline = FTRACE_GRAPH_TRAMP_ADDR, | |
aec0be2d | 5610 | /* trampoline_size is only needed for dynamically allocated tramps */ |
5f151b24 SRRH |
5611 | #endif |
5612 | ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash) | |
5613 | }; | |
5614 | ||
e49dc19c SR |
5615 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
5616 | { | |
5617 | return 0; | |
5618 | } | |
5619 | ||
287b6e68 FW |
5620 | /* The callbacks that hook a function */ |
5621 | trace_func_graph_ret_t ftrace_graph_return = | |
5622 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 5623 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
23a8e844 | 5624 | static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
5625 | |
5626 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
5627 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
5628 | { | |
5629 | int i; | |
5630 | int ret = 0; | |
5631 | unsigned long flags; | |
5632 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
5633 | struct task_struct *g, *t; | |
5634 | ||
5635 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
5636 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
5637 | * sizeof(struct ftrace_ret_stack), | |
5638 | GFP_KERNEL); | |
5639 | if (!ret_stack_list[i]) { | |
5640 | start = 0; | |
5641 | end = i; | |
5642 | ret = -ENOMEM; | |
5643 | goto free; | |
5644 | } | |
5645 | } | |
5646 | ||
5647 | read_lock_irqsave(&tasklist_lock, flags); | |
5648 | do_each_thread(g, t) { | |
5649 | if (start == end) { | |
5650 | ret = -EAGAIN; | |
5651 | goto unlock; | |
5652 | } | |
5653 | ||
5654 | if (t->ret_stack == NULL) { | |
380c4b14 | 5655 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 5656 | atomic_set(&t->trace_overrun, 0); |
26c01624 SR |
5657 | t->curr_ret_stack = -1; |
5658 | /* Make sure the tasks see the -1 first: */ | |
5659 | smp_wmb(); | |
5660 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
5661 | } |
5662 | } while_each_thread(g, t); | |
5663 | ||
5664 | unlock: | |
5665 | read_unlock_irqrestore(&tasklist_lock, flags); | |
5666 | free: | |
5667 | for (i = start; i < end; i++) | |
5668 | kfree(ret_stack_list[i]); | |
5669 | return ret; | |
5670 | } | |
5671 | ||
8aef2d28 | 5672 | static void |
38516ab5 SR |
5673 | ftrace_graph_probe_sched_switch(void *ignore, |
5674 | struct task_struct *prev, struct task_struct *next) | |
8aef2d28 SR |
5675 | { |
5676 | unsigned long long timestamp; | |
5677 | int index; | |
5678 | ||
be6f164a SR |
5679 | /* |
5680 | * Does the user want to count the time a function was asleep. | |
5681 | * If so, do not update the time stamps. | |
5682 | */ | |
5683 | if (trace_flags & TRACE_ITER_SLEEP_TIME) | |
5684 | return; | |
5685 | ||
8aef2d28 SR |
5686 | timestamp = trace_clock_local(); |
5687 | ||
5688 | prev->ftrace_timestamp = timestamp; | |
5689 | ||
5690 | /* only process tasks that we timestamped */ | |
5691 | if (!next->ftrace_timestamp) | |
5692 | return; | |
5693 | ||
5694 | /* | |
5695 | * Update all the counters in next to make up for the | |
5696 | * time next was sleeping. | |
5697 | */ | |
5698 | timestamp -= next->ftrace_timestamp; | |
5699 | ||
5700 | for (index = next->curr_ret_stack; index >= 0; index--) | |
5701 | next->ret_stack[index].calltime += timestamp; | |
5702 | } | |
5703 | ||
f201ae23 | 5704 | /* Allocate a return stack for each task */ |
fb52607a | 5705 | static int start_graph_tracing(void) |
f201ae23 FW |
5706 | { |
5707 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 5708 | int ret, cpu; |
f201ae23 FW |
5709 | |
5710 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
5711 | sizeof(struct ftrace_ret_stack *), | |
5712 | GFP_KERNEL); | |
5713 | ||
5714 | if (!ret_stack_list) | |
5715 | return -ENOMEM; | |
5716 | ||
5b058bcd | 5717 | /* The cpu_boot init_task->ret_stack will never be freed */ |
179c498a SR |
5718 | for_each_online_cpu(cpu) { |
5719 | if (!idle_task(cpu)->ret_stack) | |
868baf07 | 5720 | ftrace_graph_init_idle_task(idle_task(cpu), cpu); |
179c498a | 5721 | } |
5b058bcd | 5722 | |
f201ae23 FW |
5723 | do { |
5724 | ret = alloc_retstack_tasklist(ret_stack_list); | |
5725 | } while (ret == -EAGAIN); | |
5726 | ||
8aef2d28 | 5727 | if (!ret) { |
38516ab5 | 5728 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
8aef2d28 SR |
5729 | if (ret) |
5730 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
5731 | " probe to kernel_sched_switch\n"); | |
5732 | } | |
5733 | ||
f201ae23 FW |
5734 | kfree(ret_stack_list); |
5735 | return ret; | |
5736 | } | |
5737 | ||
4a2b8dda FW |
5738 | /* |
5739 | * Hibernation protection. | |
5740 | * The state of the current task is too much unstable during | |
5741 | * suspend/restore to disk. We want to protect against that. | |
5742 | */ | |
5743 | static int | |
5744 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
5745 | void *unused) | |
5746 | { | |
5747 | switch (state) { | |
5748 | case PM_HIBERNATION_PREPARE: | |
5749 | pause_graph_tracing(); | |
5750 | break; | |
5751 | ||
5752 | case PM_POST_HIBERNATION: | |
5753 | unpause_graph_tracing(); | |
5754 | break; | |
5755 | } | |
5756 | return NOTIFY_DONE; | |
5757 | } | |
5758 | ||
23a8e844 SRRH |
5759 | static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace) |
5760 | { | |
5761 | if (!ftrace_ops_test(&global_ops, trace->func, NULL)) | |
5762 | return 0; | |
5763 | return __ftrace_graph_entry(trace); | |
5764 | } | |
5765 | ||
5766 | /* | |
5767 | * The function graph tracer should only trace the functions defined | |
5768 | * by set_ftrace_filter and set_ftrace_notrace. If another function | |
5769 | * tracer ops is registered, the graph tracer requires testing the | |
5770 | * function against the global ops, and not just trace any function | |
5771 | * that any ftrace_ops registered. | |
5772 | */ | |
5773 | static void update_function_graph_func(void) | |
5774 | { | |
5f151b24 SRRH |
5775 | struct ftrace_ops *op; |
5776 | bool do_test = false; | |
5777 | ||
5778 | /* | |
5779 | * The graph and global ops share the same set of functions | |
5780 | * to test. If any other ops is on the list, then | |
5781 | * the graph tracing needs to test if its the function | |
5782 | * it should call. | |
5783 | */ | |
5784 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
5785 | if (op != &global_ops && op != &graph_ops && | |
5786 | op != &ftrace_list_end) { | |
5787 | do_test = true; | |
5788 | /* in double loop, break out with goto */ | |
5789 | goto out; | |
5790 | } | |
5791 | } while_for_each_ftrace_op(op); | |
5792 | out: | |
5793 | if (do_test) | |
23a8e844 | 5794 | ftrace_graph_entry = ftrace_graph_entry_test; |
5f151b24 SRRH |
5795 | else |
5796 | ftrace_graph_entry = __ftrace_graph_entry; | |
23a8e844 SRRH |
5797 | } |
5798 | ||
8275f69f MK |
5799 | static struct notifier_block ftrace_suspend_notifier = { |
5800 | .notifier_call = ftrace_suspend_notifier_call, | |
5801 | }; | |
5802 | ||
287b6e68 FW |
5803 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
5804 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 5805 | { |
e7d3737e FW |
5806 | int ret = 0; |
5807 | ||
e6ea44e9 | 5808 | mutex_lock(&ftrace_lock); |
e7d3737e | 5809 | |
05ce5818 | 5810 | /* we currently allow only one tracer registered at a time */ |
597af815 | 5811 | if (ftrace_graph_active) { |
05ce5818 SR |
5812 | ret = -EBUSY; |
5813 | goto out; | |
5814 | } | |
5815 | ||
4a2b8dda FW |
5816 | register_pm_notifier(&ftrace_suspend_notifier); |
5817 | ||
597af815 | 5818 | ftrace_graph_active++; |
fb52607a | 5819 | ret = start_graph_tracing(); |
f201ae23 | 5820 | if (ret) { |
597af815 | 5821 | ftrace_graph_active--; |
f201ae23 FW |
5822 | goto out; |
5823 | } | |
e53a6319 | 5824 | |
287b6e68 | 5825 | ftrace_graph_return = retfunc; |
23a8e844 SRRH |
5826 | |
5827 | /* | |
5828 | * Update the indirect function to the entryfunc, and the | |
5829 | * function that gets called to the entry_test first. Then | |
5830 | * call the update fgraph entry function to determine if | |
5831 | * the entryfunc should be called directly or not. | |
5832 | */ | |
5833 | __ftrace_graph_entry = entryfunc; | |
5834 | ftrace_graph_entry = ftrace_graph_entry_test; | |
5835 | update_function_graph_func(); | |
e53a6319 | 5836 | |
5f151b24 | 5837 | ret = ftrace_startup(&graph_ops, FTRACE_START_FUNC_RET); |
e7d3737e | 5838 | out: |
e6ea44e9 | 5839 | mutex_unlock(&ftrace_lock); |
e7d3737e | 5840 | return ret; |
15e6cb36 FW |
5841 | } |
5842 | ||
fb52607a | 5843 | void unregister_ftrace_graph(void) |
15e6cb36 | 5844 | { |
e6ea44e9 | 5845 | mutex_lock(&ftrace_lock); |
e7d3737e | 5846 | |
597af815 | 5847 | if (unlikely(!ftrace_graph_active)) |
2aad1b76 SR |
5848 | goto out; |
5849 | ||
597af815 | 5850 | ftrace_graph_active--; |
287b6e68 | 5851 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 5852 | ftrace_graph_entry = ftrace_graph_entry_stub; |
23a8e844 | 5853 | __ftrace_graph_entry = ftrace_graph_entry_stub; |
5f151b24 | 5854 | ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET); |
4a2b8dda | 5855 | unregister_pm_notifier(&ftrace_suspend_notifier); |
38516ab5 | 5856 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
e7d3737e | 5857 | |
f3bea491 SRRH |
5858 | #ifdef CONFIG_DYNAMIC_FTRACE |
5859 | /* | |
5860 | * Function graph does not allocate the trampoline, but | |
5861 | * other global_ops do. We need to reset the ALLOC_TRAMP flag | |
5862 | * if one was used. | |
5863 | */ | |
5864 | global_ops.trampoline = save_global_trampoline; | |
5865 | if (save_global_flags & FTRACE_OPS_FL_ALLOC_TRAMP) | |
5866 | global_ops.flags |= FTRACE_OPS_FL_ALLOC_TRAMP; | |
5867 | #endif | |
5868 | ||
2aad1b76 | 5869 | out: |
e6ea44e9 | 5870 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 5871 | } |
f201ae23 | 5872 | |
868baf07 SR |
5873 | static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack); |
5874 | ||
5875 | static void | |
5876 | graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack) | |
5877 | { | |
5878 | atomic_set(&t->tracing_graph_pause, 0); | |
5879 | atomic_set(&t->trace_overrun, 0); | |
5880 | t->ftrace_timestamp = 0; | |
25985edc | 5881 | /* make curr_ret_stack visible before we add the ret_stack */ |
868baf07 SR |
5882 | smp_wmb(); |
5883 | t->ret_stack = ret_stack; | |
5884 | } | |
5885 | ||
5886 | /* | |
5887 | * Allocate a return stack for the idle task. May be the first | |
5888 | * time through, or it may be done by CPU hotplug online. | |
5889 | */ | |
5890 | void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) | |
5891 | { | |
5892 | t->curr_ret_stack = -1; | |
5893 | /* | |
5894 | * The idle task has no parent, it either has its own | |
5895 | * stack or no stack at all. | |
5896 | */ | |
5897 | if (t->ret_stack) | |
5898 | WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu)); | |
5899 | ||
5900 | if (ftrace_graph_active) { | |
5901 | struct ftrace_ret_stack *ret_stack; | |
5902 | ||
5903 | ret_stack = per_cpu(idle_ret_stack, cpu); | |
5904 | if (!ret_stack) { | |
5905 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
5906 | * sizeof(struct ftrace_ret_stack), | |
5907 | GFP_KERNEL); | |
5908 | if (!ret_stack) | |
5909 | return; | |
5910 | per_cpu(idle_ret_stack, cpu) = ret_stack; | |
5911 | } | |
5912 | graph_init_task(t, ret_stack); | |
5913 | } | |
5914 | } | |
5915 | ||
f201ae23 | 5916 | /* Allocate a return stack for newly created task */ |
fb52607a | 5917 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 5918 | { |
84047e36 SR |
5919 | /* Make sure we do not use the parent ret_stack */ |
5920 | t->ret_stack = NULL; | |
ea14eb71 | 5921 | t->curr_ret_stack = -1; |
84047e36 | 5922 | |
597af815 | 5923 | if (ftrace_graph_active) { |
82310a32 SR |
5924 | struct ftrace_ret_stack *ret_stack; |
5925 | ||
5926 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
f201ae23 FW |
5927 | * sizeof(struct ftrace_ret_stack), |
5928 | GFP_KERNEL); | |
82310a32 | 5929 | if (!ret_stack) |
f201ae23 | 5930 | return; |
868baf07 | 5931 | graph_init_task(t, ret_stack); |
84047e36 | 5932 | } |
f201ae23 FW |
5933 | } |
5934 | ||
fb52607a | 5935 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 5936 | { |
eae849ca FW |
5937 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
5938 | ||
f201ae23 | 5939 | t->ret_stack = NULL; |
eae849ca FW |
5940 | /* NULL must become visible to IRQs before we free it: */ |
5941 | barrier(); | |
5942 | ||
5943 | kfree(ret_stack); | |
f201ae23 | 5944 | } |
15e6cb36 | 5945 | #endif |