Commit | Line | Data |
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16444a8a ACM |
1 | /* |
2 | * Infrastructure for profiling code inserted by 'gcc -pg'. | |
3 | * | |
4 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> | |
5 | * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com> | |
6 | * | |
7 | * Originally ported from the -rt patch by: | |
8 | * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com> | |
9 | * | |
10 | * Based on code in the latency_tracer, that is: | |
11 | * | |
12 | * Copyright (C) 2004-2006 Ingo Molnar | |
6d49e352 | 13 | * Copyright (C) 2004 Nadia Yvette Chambers |
16444a8a ACM |
14 | */ |
15 | ||
3d083395 SR |
16 | #include <linux/stop_machine.h> |
17 | #include <linux/clocksource.h> | |
18 | #include <linux/kallsyms.h> | |
5072c59f | 19 | #include <linux/seq_file.h> |
4a2b8dda | 20 | #include <linux/suspend.h> |
8434dc93 | 21 | #include <linux/tracefs.h> |
3d083395 | 22 | #include <linux/hardirq.h> |
2d8b820b | 23 | #include <linux/kthread.h> |
5072c59f | 24 | #include <linux/uaccess.h> |
5855fead | 25 | #include <linux/bsearch.h> |
56d82e00 | 26 | #include <linux/module.h> |
2d8b820b | 27 | #include <linux/ftrace.h> |
b0fc494f | 28 | #include <linux/sysctl.h> |
5a0e3ad6 | 29 | #include <linux/slab.h> |
5072c59f | 30 | #include <linux/ctype.h> |
68950619 | 31 | #include <linux/sort.h> |
3d083395 | 32 | #include <linux/list.h> |
59df055f | 33 | #include <linux/hash.h> |
3f379b03 | 34 | #include <linux/rcupdate.h> |
3d083395 | 35 | |
ad8d75ff | 36 | #include <trace/events/sched.h> |
8aef2d28 | 37 | |
2af15d6a | 38 | #include <asm/setup.h> |
395a59d0 | 39 | |
0706f1c4 | 40 | #include "trace_output.h" |
bac429f0 | 41 | #include "trace_stat.h" |
16444a8a | 42 | |
6912896e | 43 | #define FTRACE_WARN_ON(cond) \ |
0778d9ad SR |
44 | ({ \ |
45 | int ___r = cond; \ | |
46 | if (WARN_ON(___r)) \ | |
6912896e | 47 | ftrace_kill(); \ |
0778d9ad SR |
48 | ___r; \ |
49 | }) | |
6912896e SR |
50 | |
51 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
0778d9ad SR |
52 | ({ \ |
53 | int ___r = cond; \ | |
54 | if (WARN_ON_ONCE(___r)) \ | |
6912896e | 55 | ftrace_kill(); \ |
0778d9ad SR |
56 | ___r; \ |
57 | }) | |
6912896e | 58 | |
8fc0c701 SR |
59 | /* hash bits for specific function selection */ |
60 | #define FTRACE_HASH_BITS 7 | |
61 | #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS) | |
33dc9b12 SR |
62 | #define FTRACE_HASH_DEFAULT_BITS 10 |
63 | #define FTRACE_HASH_MAX_BITS 12 | |
8fc0c701 | 64 | |
4104d326 | 65 | #define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_CONTROL) |
e248491a | 66 | |
f04f24fb | 67 | #ifdef CONFIG_DYNAMIC_FTRACE |
33b7f99c SRRH |
68 | #define INIT_OPS_HASH(opsname) \ |
69 | .func_hash = &opsname.local_hash, \ | |
70 | .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock), | |
5f151b24 SRRH |
71 | #define ASSIGN_OPS_HASH(opsname, val) \ |
72 | .func_hash = val, \ | |
73 | .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock), | |
f04f24fb | 74 | #else |
33b7f99c | 75 | #define INIT_OPS_HASH(opsname) |
5f151b24 | 76 | #define ASSIGN_OPS_HASH(opsname, val) |
f04f24fb MH |
77 | #endif |
78 | ||
2f5f6ad9 SR |
79 | static struct ftrace_ops ftrace_list_end __read_mostly = { |
80 | .func = ftrace_stub, | |
395b97a3 | 81 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB, |
33b7f99c | 82 | INIT_OPS_HASH(ftrace_list_end) |
2f5f6ad9 SR |
83 | }; |
84 | ||
4eebcc81 SR |
85 | /* ftrace_enabled is a method to turn ftrace on or off */ |
86 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 87 | static int last_ftrace_enabled; |
b0fc494f | 88 | |
2f5f6ad9 SR |
89 | /* Current function tracing op */ |
90 | struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end; | |
405e1d83 SRRH |
91 | /* What to set function_trace_op to */ |
92 | static struct ftrace_ops *set_function_trace_op; | |
60a7ecf4 | 93 | |
756d17ee | 94 | /* List for set_ftrace_pid's pids. */ |
95 | LIST_HEAD(ftrace_pids); | |
96 | struct ftrace_pid { | |
97 | struct list_head list; | |
98 | struct pid *pid; | |
99 | }; | |
100 | ||
e3eea140 SRRH |
101 | static bool ftrace_pids_enabled(void) |
102 | { | |
103 | return !list_empty(&ftrace_pids); | |
104 | } | |
105 | ||
106 | static void ftrace_update_trampoline(struct ftrace_ops *ops); | |
107 | ||
4eebcc81 SR |
108 | /* |
109 | * ftrace_disabled is set when an anomaly is discovered. | |
110 | * ftrace_disabled is much stronger than ftrace_enabled. | |
111 | */ | |
112 | static int ftrace_disabled __read_mostly; | |
113 | ||
52baf119 | 114 | static DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 115 | |
e248491a | 116 | static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end; |
b848914c | 117 | static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end; |
16444a8a | 118 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
2b499381 | 119 | static struct ftrace_ops global_ops; |
e248491a | 120 | static struct ftrace_ops control_ops; |
16444a8a | 121 | |
f1ff6348 SRRH |
122 | static void ftrace_ops_recurs_func(unsigned long ip, unsigned long parent_ip, |
123 | struct ftrace_ops *op, struct pt_regs *regs); | |
124 | ||
2f5f6ad9 SR |
125 | #if ARCH_SUPPORTS_FTRACE_OPS |
126 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 127 | struct ftrace_ops *op, struct pt_regs *regs); |
2f5f6ad9 SR |
128 | #else |
129 | /* See comment below, where ftrace_ops_list_func is defined */ | |
130 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip); | |
131 | #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops) | |
132 | #endif | |
b848914c | 133 | |
0a016409 SR |
134 | /* |
135 | * Traverse the ftrace_global_list, invoking all entries. The reason that we | |
1bb539ca | 136 | * can use rcu_dereference_raw_notrace() is that elements removed from this list |
0a016409 | 137 | * are simply leaked, so there is no need to interact with a grace-period |
1bb539ca | 138 | * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle |
0a016409 SR |
139 | * concurrent insertions into the ftrace_global_list. |
140 | * | |
141 | * Silly Alpha and silly pointer-speculation compiler optimizations! | |
142 | */ | |
143 | #define do_for_each_ftrace_op(op, list) \ | |
1bb539ca | 144 | op = rcu_dereference_raw_notrace(list); \ |
0a016409 SR |
145 | do |
146 | ||
147 | /* | |
148 | * Optimized for just a single item in the list (as that is the normal case). | |
149 | */ | |
150 | #define while_for_each_ftrace_op(op) \ | |
1bb539ca | 151 | while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \ |
0a016409 SR |
152 | unlikely((op) != &ftrace_list_end)) |
153 | ||
f04f24fb MH |
154 | static inline void ftrace_ops_init(struct ftrace_ops *ops) |
155 | { | |
156 | #ifdef CONFIG_DYNAMIC_FTRACE | |
157 | if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) { | |
33b7f99c SRRH |
158 | mutex_init(&ops->local_hash.regex_lock); |
159 | ops->func_hash = &ops->local_hash; | |
f04f24fb MH |
160 | ops->flags |= FTRACE_OPS_FL_INITIALIZED; |
161 | } | |
162 | #endif | |
163 | } | |
164 | ||
ea701f11 SR |
165 | /** |
166 | * ftrace_nr_registered_ops - return number of ops registered | |
167 | * | |
168 | * Returns the number of ftrace_ops registered and tracing functions | |
169 | */ | |
170 | int ftrace_nr_registered_ops(void) | |
171 | { | |
172 | struct ftrace_ops *ops; | |
173 | int cnt = 0; | |
174 | ||
175 | mutex_lock(&ftrace_lock); | |
176 | ||
177 | for (ops = ftrace_ops_list; | |
178 | ops != &ftrace_list_end; ops = ops->next) | |
179 | cnt++; | |
180 | ||
181 | mutex_unlock(&ftrace_lock); | |
182 | ||
183 | return cnt; | |
184 | } | |
185 | ||
2f5f6ad9 | 186 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 187 | struct ftrace_ops *op, struct pt_regs *regs) |
df4fc315 | 188 | { |
0ef8cde5 | 189 | if (!test_tsk_trace_trace(current)) |
df4fc315 SR |
190 | return; |
191 | ||
e3eea140 | 192 | op->saved_func(ip, parent_ip, op, regs); |
df4fc315 SR |
193 | } |
194 | ||
16444a8a | 195 | /** |
3d083395 | 196 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 197 | * |
3d083395 SR |
198 | * This NULLs the ftrace function and in essence stops |
199 | * tracing. There may be lag | |
16444a8a | 200 | */ |
3d083395 | 201 | void clear_ftrace_function(void) |
16444a8a | 202 | { |
3d083395 SR |
203 | ftrace_trace_function = ftrace_stub; |
204 | } | |
205 | ||
e248491a JO |
206 | static void control_ops_disable_all(struct ftrace_ops *ops) |
207 | { | |
208 | int cpu; | |
209 | ||
210 | for_each_possible_cpu(cpu) | |
211 | *per_cpu_ptr(ops->disabled, cpu) = 1; | |
212 | } | |
213 | ||
214 | static int control_ops_alloc(struct ftrace_ops *ops) | |
215 | { | |
216 | int __percpu *disabled; | |
217 | ||
218 | disabled = alloc_percpu(int); | |
219 | if (!disabled) | |
220 | return -ENOMEM; | |
221 | ||
222 | ops->disabled = disabled; | |
223 | control_ops_disable_all(ops); | |
224 | return 0; | |
225 | } | |
226 | ||
405e1d83 SRRH |
227 | static void ftrace_sync(struct work_struct *work) |
228 | { | |
229 | /* | |
230 | * This function is just a stub to implement a hard force | |
231 | * of synchronize_sched(). This requires synchronizing | |
232 | * tasks even in userspace and idle. | |
233 | * | |
234 | * Yes, function tracing is rude. | |
235 | */ | |
236 | } | |
237 | ||
238 | static void ftrace_sync_ipi(void *data) | |
239 | { | |
240 | /* Probably not needed, but do it anyway */ | |
241 | smp_rmb(); | |
242 | } | |
243 | ||
23a8e844 SRRH |
244 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
245 | static void update_function_graph_func(void); | |
55577204 SRRH |
246 | |
247 | /* Both enabled by default (can be cleared by function_graph tracer flags */ | |
248 | static bool fgraph_sleep_time = true; | |
249 | static bool fgraph_graph_time = true; | |
250 | ||
23a8e844 SRRH |
251 | #else |
252 | static inline void update_function_graph_func(void) { } | |
253 | #endif | |
254 | ||
00ccbf2f SRRH |
255 | |
256 | static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops) | |
257 | { | |
258 | /* | |
259 | * If this is a dynamic ops or we force list func, | |
260 | * then it needs to call the list anyway. | |
261 | */ | |
262 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC || FTRACE_FORCE_LIST_FUNC) | |
263 | return ftrace_ops_list_func; | |
264 | ||
265 | return ftrace_ops_get_func(ops); | |
266 | } | |
267 | ||
2b499381 SR |
268 | static void update_ftrace_function(void) |
269 | { | |
270 | ftrace_func_t func; | |
271 | ||
f7aad4e1 SRRH |
272 | /* |
273 | * Prepare the ftrace_ops that the arch callback will use. | |
274 | * If there's only one ftrace_ops registered, the ftrace_ops_list | |
275 | * will point to the ops we want. | |
276 | */ | |
277 | set_function_trace_op = ftrace_ops_list; | |
278 | ||
279 | /* If there's no ftrace_ops registered, just call the stub function */ | |
280 | if (ftrace_ops_list == &ftrace_list_end) { | |
281 | func = ftrace_stub; | |
282 | ||
cdbe61bf SR |
283 | /* |
284 | * If we are at the end of the list and this ops is | |
4740974a SR |
285 | * recursion safe and not dynamic and the arch supports passing ops, |
286 | * then have the mcount trampoline call the function directly. | |
cdbe61bf | 287 | */ |
f7aad4e1 | 288 | } else if (ftrace_ops_list->next == &ftrace_list_end) { |
00ccbf2f | 289 | func = ftrace_ops_get_list_func(ftrace_ops_list); |
f7aad4e1 | 290 | |
2f5f6ad9 SR |
291 | } else { |
292 | /* Just use the default ftrace_ops */ | |
405e1d83 | 293 | set_function_trace_op = &ftrace_list_end; |
b848914c | 294 | func = ftrace_ops_list_func; |
2f5f6ad9 | 295 | } |
2b499381 | 296 | |
5f8bf2d2 SRRH |
297 | update_function_graph_func(); |
298 | ||
405e1d83 SRRH |
299 | /* If there's no change, then do nothing more here */ |
300 | if (ftrace_trace_function == func) | |
301 | return; | |
302 | ||
303 | /* | |
304 | * If we are using the list function, it doesn't care | |
305 | * about the function_trace_ops. | |
306 | */ | |
307 | if (func == ftrace_ops_list_func) { | |
308 | ftrace_trace_function = func; | |
309 | /* | |
310 | * Don't even bother setting function_trace_ops, | |
311 | * it would be racy to do so anyway. | |
312 | */ | |
313 | return; | |
314 | } | |
315 | ||
316 | #ifndef CONFIG_DYNAMIC_FTRACE | |
317 | /* | |
318 | * For static tracing, we need to be a bit more careful. | |
319 | * The function change takes affect immediately. Thus, | |
320 | * we need to coorditate the setting of the function_trace_ops | |
321 | * with the setting of the ftrace_trace_function. | |
322 | * | |
323 | * Set the function to the list ops, which will call the | |
324 | * function we want, albeit indirectly, but it handles the | |
325 | * ftrace_ops and doesn't depend on function_trace_op. | |
326 | */ | |
327 | ftrace_trace_function = ftrace_ops_list_func; | |
328 | /* | |
329 | * Make sure all CPUs see this. Yes this is slow, but static | |
330 | * tracing is slow and nasty to have enabled. | |
331 | */ | |
332 | schedule_on_each_cpu(ftrace_sync); | |
333 | /* Now all cpus are using the list ops. */ | |
334 | function_trace_op = set_function_trace_op; | |
335 | /* Make sure the function_trace_op is visible on all CPUs */ | |
336 | smp_wmb(); | |
337 | /* Nasty way to force a rmb on all cpus */ | |
338 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
339 | /* OK, we are all set to update the ftrace_trace_function now! */ | |
340 | #endif /* !CONFIG_DYNAMIC_FTRACE */ | |
341 | ||
491d0dcf | 342 | ftrace_trace_function = func; |
491d0dcf SR |
343 | } |
344 | ||
7eea4fce JW |
345 | int using_ftrace_ops_list_func(void) |
346 | { | |
347 | return ftrace_trace_function == ftrace_ops_list_func; | |
348 | } | |
349 | ||
2b499381 | 350 | static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
3d083395 | 351 | { |
2b499381 | 352 | ops->next = *list; |
16444a8a | 353 | /* |
b848914c | 354 | * We are entering ops into the list but another |
16444a8a ACM |
355 | * CPU might be walking that list. We need to make sure |
356 | * the ops->next pointer is valid before another CPU sees | |
b848914c | 357 | * the ops pointer included into the list. |
16444a8a | 358 | */ |
2b499381 | 359 | rcu_assign_pointer(*list, ops); |
16444a8a ACM |
360 | } |
361 | ||
2b499381 | 362 | static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
16444a8a | 363 | { |
16444a8a | 364 | struct ftrace_ops **p; |
16444a8a ACM |
365 | |
366 | /* | |
3d083395 SR |
367 | * If we are removing the last function, then simply point |
368 | * to the ftrace_stub. | |
16444a8a | 369 | */ |
2b499381 SR |
370 | if (*list == ops && ops->next == &ftrace_list_end) { |
371 | *list = &ftrace_list_end; | |
e6ea44e9 | 372 | return 0; |
16444a8a ACM |
373 | } |
374 | ||
2b499381 | 375 | for (p = list; *p != &ftrace_list_end; p = &(*p)->next) |
16444a8a ACM |
376 | if (*p == ops) |
377 | break; | |
378 | ||
e6ea44e9 SR |
379 | if (*p != ops) |
380 | return -1; | |
16444a8a ACM |
381 | |
382 | *p = (*p)->next; | |
2b499381 SR |
383 | return 0; |
384 | } | |
16444a8a | 385 | |
e248491a JO |
386 | static void add_ftrace_list_ops(struct ftrace_ops **list, |
387 | struct ftrace_ops *main_ops, | |
388 | struct ftrace_ops *ops) | |
389 | { | |
390 | int first = *list == &ftrace_list_end; | |
391 | add_ftrace_ops(list, ops); | |
392 | if (first) | |
393 | add_ftrace_ops(&ftrace_ops_list, main_ops); | |
394 | } | |
395 | ||
396 | static int remove_ftrace_list_ops(struct ftrace_ops **list, | |
397 | struct ftrace_ops *main_ops, | |
398 | struct ftrace_ops *ops) | |
399 | { | |
400 | int ret = remove_ftrace_ops(list, ops); | |
401 | if (!ret && *list == &ftrace_list_end) | |
402 | ret = remove_ftrace_ops(&ftrace_ops_list, main_ops); | |
403 | return ret; | |
404 | } | |
405 | ||
f3bea491 SRRH |
406 | static void ftrace_update_trampoline(struct ftrace_ops *ops); |
407 | ||
2b499381 SR |
408 | static int __register_ftrace_function(struct ftrace_ops *ops) |
409 | { | |
591dffda SRRH |
410 | if (ops->flags & FTRACE_OPS_FL_DELETED) |
411 | return -EINVAL; | |
412 | ||
b848914c SR |
413 | if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) |
414 | return -EBUSY; | |
415 | ||
06aeaaea | 416 | #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
08f6fba5 SR |
417 | /* |
418 | * If the ftrace_ops specifies SAVE_REGS, then it only can be used | |
419 | * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set. | |
420 | * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant. | |
421 | */ | |
422 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS && | |
423 | !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)) | |
424 | return -EINVAL; | |
425 | ||
426 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED) | |
427 | ops->flags |= FTRACE_OPS_FL_SAVE_REGS; | |
428 | #endif | |
429 | ||
cdbe61bf SR |
430 | if (!core_kernel_data((unsigned long)ops)) |
431 | ops->flags |= FTRACE_OPS_FL_DYNAMIC; | |
432 | ||
4104d326 | 433 | if (ops->flags & FTRACE_OPS_FL_CONTROL) { |
e248491a JO |
434 | if (control_ops_alloc(ops)) |
435 | return -ENOMEM; | |
436 | add_ftrace_list_ops(&ftrace_control_list, &control_ops, ops); | |
fe578ba3 SRRH |
437 | /* The control_ops needs the trampoline update */ |
438 | ops = &control_ops; | |
b848914c SR |
439 | } else |
440 | add_ftrace_ops(&ftrace_ops_list, ops); | |
441 | ||
e3eea140 SRRH |
442 | /* Always save the function, and reset at unregistering */ |
443 | ops->saved_func = ops->func; | |
444 | ||
445 | if (ops->flags & FTRACE_OPS_FL_PID && ftrace_pids_enabled()) | |
446 | ops->func = ftrace_pid_func; | |
447 | ||
f3bea491 SRRH |
448 | ftrace_update_trampoline(ops); |
449 | ||
2b499381 SR |
450 | if (ftrace_enabled) |
451 | update_ftrace_function(); | |
452 | ||
453 | return 0; | |
454 | } | |
455 | ||
456 | static int __unregister_ftrace_function(struct ftrace_ops *ops) | |
457 | { | |
458 | int ret; | |
459 | ||
b848914c SR |
460 | if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) |
461 | return -EBUSY; | |
462 | ||
4104d326 | 463 | if (ops->flags & FTRACE_OPS_FL_CONTROL) { |
e248491a JO |
464 | ret = remove_ftrace_list_ops(&ftrace_control_list, |
465 | &control_ops, ops); | |
b848914c SR |
466 | } else |
467 | ret = remove_ftrace_ops(&ftrace_ops_list, ops); | |
468 | ||
2b499381 SR |
469 | if (ret < 0) |
470 | return ret; | |
b848914c | 471 | |
491d0dcf SR |
472 | if (ftrace_enabled) |
473 | update_ftrace_function(); | |
16444a8a | 474 | |
e3eea140 SRRH |
475 | ops->func = ops->saved_func; |
476 | ||
e6ea44e9 | 477 | return 0; |
3d083395 SR |
478 | } |
479 | ||
df4fc315 SR |
480 | static void ftrace_update_pid_func(void) |
481 | { | |
e3eea140 SRRH |
482 | bool enabled = ftrace_pids_enabled(); |
483 | struct ftrace_ops *op; | |
484 | ||
491d0dcf | 485 | /* Only do something if we are tracing something */ |
df4fc315 | 486 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 487 | return; |
df4fc315 | 488 | |
e3eea140 SRRH |
489 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
490 | if (op->flags & FTRACE_OPS_FL_PID) { | |
491 | op->func = enabled ? ftrace_pid_func : | |
492 | op->saved_func; | |
493 | ftrace_update_trampoline(op); | |
494 | } | |
495 | } while_for_each_ftrace_op(op); | |
496 | ||
491d0dcf | 497 | update_ftrace_function(); |
df4fc315 SR |
498 | } |
499 | ||
493762fc SR |
500 | #ifdef CONFIG_FUNCTION_PROFILER |
501 | struct ftrace_profile { | |
502 | struct hlist_node node; | |
503 | unsigned long ip; | |
504 | unsigned long counter; | |
0706f1c4 SR |
505 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
506 | unsigned long long time; | |
e330b3bc | 507 | unsigned long long time_squared; |
0706f1c4 | 508 | #endif |
8fc0c701 SR |
509 | }; |
510 | ||
493762fc SR |
511 | struct ftrace_profile_page { |
512 | struct ftrace_profile_page *next; | |
513 | unsigned long index; | |
514 | struct ftrace_profile records[]; | |
d61f82d0 SR |
515 | }; |
516 | ||
cafb168a SR |
517 | struct ftrace_profile_stat { |
518 | atomic_t disabled; | |
519 | struct hlist_head *hash; | |
520 | struct ftrace_profile_page *pages; | |
521 | struct ftrace_profile_page *start; | |
522 | struct tracer_stat stat; | |
523 | }; | |
524 | ||
493762fc SR |
525 | #define PROFILE_RECORDS_SIZE \ |
526 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 527 | |
493762fc SR |
528 | #define PROFILES_PER_PAGE \ |
529 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 530 | |
fb9fb015 SR |
531 | static int ftrace_profile_enabled __read_mostly; |
532 | ||
533 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
534 | static DEFINE_MUTEX(ftrace_profile_lock); |
535 | ||
cafb168a | 536 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc | 537 | |
20079ebe NK |
538 | #define FTRACE_PROFILE_HASH_BITS 10 |
539 | #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS) | |
493762fc | 540 | |
bac429f0 SR |
541 | static void * |
542 | function_stat_next(void *v, int idx) | |
543 | { | |
493762fc SR |
544 | struct ftrace_profile *rec = v; |
545 | struct ftrace_profile_page *pg; | |
bac429f0 | 546 | |
493762fc | 547 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
548 | |
549 | again: | |
0296e425 LZ |
550 | if (idx != 0) |
551 | rec++; | |
552 | ||
bac429f0 SR |
553 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
554 | pg = pg->next; | |
555 | if (!pg) | |
556 | return NULL; | |
557 | rec = &pg->records[0]; | |
493762fc SR |
558 | if (!rec->counter) |
559 | goto again; | |
bac429f0 SR |
560 | } |
561 | ||
bac429f0 SR |
562 | return rec; |
563 | } | |
564 | ||
565 | static void *function_stat_start(struct tracer_stat *trace) | |
566 | { | |
cafb168a SR |
567 | struct ftrace_profile_stat *stat = |
568 | container_of(trace, struct ftrace_profile_stat, stat); | |
569 | ||
570 | if (!stat || !stat->start) | |
571 | return NULL; | |
572 | ||
573 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
574 | } |
575 | ||
0706f1c4 SR |
576 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
577 | /* function graph compares on total time */ | |
578 | static int function_stat_cmp(void *p1, void *p2) | |
579 | { | |
580 | struct ftrace_profile *a = p1; | |
581 | struct ftrace_profile *b = p2; | |
582 | ||
583 | if (a->time < b->time) | |
584 | return -1; | |
585 | if (a->time > b->time) | |
586 | return 1; | |
587 | else | |
588 | return 0; | |
589 | } | |
590 | #else | |
591 | /* not function graph compares against hits */ | |
bac429f0 SR |
592 | static int function_stat_cmp(void *p1, void *p2) |
593 | { | |
493762fc SR |
594 | struct ftrace_profile *a = p1; |
595 | struct ftrace_profile *b = p2; | |
bac429f0 SR |
596 | |
597 | if (a->counter < b->counter) | |
598 | return -1; | |
599 | if (a->counter > b->counter) | |
600 | return 1; | |
601 | else | |
602 | return 0; | |
603 | } | |
0706f1c4 | 604 | #endif |
bac429f0 SR |
605 | |
606 | static int function_stat_headers(struct seq_file *m) | |
607 | { | |
0706f1c4 | 608 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
fa6f0cc7 RV |
609 | seq_puts(m, " Function " |
610 | "Hit Time Avg s^2\n" | |
611 | " -------- " | |
612 | "--- ---- --- ---\n"); | |
0706f1c4 | 613 | #else |
fa6f0cc7 RV |
614 | seq_puts(m, " Function Hit\n" |
615 | " -------- ---\n"); | |
0706f1c4 | 616 | #endif |
bac429f0 SR |
617 | return 0; |
618 | } | |
619 | ||
620 | static int function_stat_show(struct seq_file *m, void *v) | |
621 | { | |
493762fc | 622 | struct ftrace_profile *rec = v; |
bac429f0 | 623 | char str[KSYM_SYMBOL_LEN]; |
3aaba20f | 624 | int ret = 0; |
0706f1c4 | 625 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
626 | static struct trace_seq s; |
627 | unsigned long long avg; | |
e330b3bc | 628 | unsigned long long stddev; |
0706f1c4 | 629 | #endif |
3aaba20f LZ |
630 | mutex_lock(&ftrace_profile_lock); |
631 | ||
632 | /* we raced with function_profile_reset() */ | |
633 | if (unlikely(rec->counter == 0)) { | |
634 | ret = -EBUSY; | |
635 | goto out; | |
636 | } | |
bac429f0 | 637 | |
8e436ca0 UT |
638 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
639 | avg = rec->time; | |
640 | do_div(avg, rec->counter); | |
641 | if (tracing_thresh && (avg < tracing_thresh)) | |
642 | goto out; | |
643 | #endif | |
644 | ||
bac429f0 | 645 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
0706f1c4 SR |
646 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
647 | ||
648 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
fa6f0cc7 | 649 | seq_puts(m, " "); |
34886c8b | 650 | |
e330b3bc CD |
651 | /* Sample standard deviation (s^2) */ |
652 | if (rec->counter <= 1) | |
653 | stddev = 0; | |
654 | else { | |
52d85d76 JL |
655 | /* |
656 | * Apply Welford's method: | |
657 | * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2) | |
658 | */ | |
659 | stddev = rec->counter * rec->time_squared - | |
660 | rec->time * rec->time; | |
661 | ||
e330b3bc CD |
662 | /* |
663 | * Divide only 1000 for ns^2 -> us^2 conversion. | |
664 | * trace_print_graph_duration will divide 1000 again. | |
665 | */ | |
52d85d76 | 666 | do_div(stddev, rec->counter * (rec->counter - 1) * 1000); |
e330b3bc CD |
667 | } |
668 | ||
34886c8b SR |
669 | trace_seq_init(&s); |
670 | trace_print_graph_duration(rec->time, &s); | |
671 | trace_seq_puts(&s, " "); | |
672 | trace_print_graph_duration(avg, &s); | |
e330b3bc CD |
673 | trace_seq_puts(&s, " "); |
674 | trace_print_graph_duration(stddev, &s); | |
0706f1c4 | 675 | trace_print_seq(m, &s); |
0706f1c4 SR |
676 | #endif |
677 | seq_putc(m, '\n'); | |
3aaba20f LZ |
678 | out: |
679 | mutex_unlock(&ftrace_profile_lock); | |
bac429f0 | 680 | |
3aaba20f | 681 | return ret; |
bac429f0 SR |
682 | } |
683 | ||
cafb168a | 684 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 685 | { |
493762fc | 686 | struct ftrace_profile_page *pg; |
bac429f0 | 687 | |
cafb168a | 688 | pg = stat->pages = stat->start; |
bac429f0 | 689 | |
493762fc SR |
690 | while (pg) { |
691 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
692 | pg->index = 0; | |
693 | pg = pg->next; | |
bac429f0 SR |
694 | } |
695 | ||
cafb168a | 696 | memset(stat->hash, 0, |
493762fc SR |
697 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
698 | } | |
bac429f0 | 699 | |
cafb168a | 700 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
701 | { |
702 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
703 | int functions; |
704 | int pages; | |
493762fc | 705 | int i; |
bac429f0 | 706 | |
493762fc | 707 | /* If we already allocated, do nothing */ |
cafb168a | 708 | if (stat->pages) |
493762fc | 709 | return 0; |
bac429f0 | 710 | |
cafb168a SR |
711 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
712 | if (!stat->pages) | |
493762fc | 713 | return -ENOMEM; |
bac429f0 | 714 | |
318e0a73 SR |
715 | #ifdef CONFIG_DYNAMIC_FTRACE |
716 | functions = ftrace_update_tot_cnt; | |
717 | #else | |
718 | /* | |
719 | * We do not know the number of functions that exist because | |
720 | * dynamic tracing is what counts them. With past experience | |
721 | * we have around 20K functions. That should be more than enough. | |
722 | * It is highly unlikely we will execute every function in | |
723 | * the kernel. | |
724 | */ | |
725 | functions = 20000; | |
726 | #endif | |
727 | ||
cafb168a | 728 | pg = stat->start = stat->pages; |
bac429f0 | 729 | |
318e0a73 SR |
730 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
731 | ||
39e30cd1 | 732 | for (i = 1; i < pages; i++) { |
493762fc | 733 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 734 | if (!pg->next) |
318e0a73 | 735 | goto out_free; |
493762fc SR |
736 | pg = pg->next; |
737 | } | |
738 | ||
739 | return 0; | |
318e0a73 SR |
740 | |
741 | out_free: | |
742 | pg = stat->start; | |
743 | while (pg) { | |
744 | unsigned long tmp = (unsigned long)pg; | |
745 | ||
746 | pg = pg->next; | |
747 | free_page(tmp); | |
748 | } | |
749 | ||
318e0a73 SR |
750 | stat->pages = NULL; |
751 | stat->start = NULL; | |
752 | ||
753 | return -ENOMEM; | |
bac429f0 SR |
754 | } |
755 | ||
cafb168a | 756 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 757 | { |
cafb168a | 758 | struct ftrace_profile_stat *stat; |
493762fc | 759 | int size; |
bac429f0 | 760 | |
cafb168a SR |
761 | stat = &per_cpu(ftrace_profile_stats, cpu); |
762 | ||
763 | if (stat->hash) { | |
493762fc | 764 | /* If the profile is already created, simply reset it */ |
cafb168a | 765 | ftrace_profile_reset(stat); |
493762fc SR |
766 | return 0; |
767 | } | |
bac429f0 | 768 | |
493762fc SR |
769 | /* |
770 | * We are profiling all functions, but usually only a few thousand | |
771 | * functions are hit. We'll make a hash of 1024 items. | |
772 | */ | |
773 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 774 | |
cafb168a | 775 | stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
493762fc | 776 | |
cafb168a | 777 | if (!stat->hash) |
493762fc SR |
778 | return -ENOMEM; |
779 | ||
318e0a73 | 780 | /* Preallocate the function profiling pages */ |
cafb168a SR |
781 | if (ftrace_profile_pages_init(stat) < 0) { |
782 | kfree(stat->hash); | |
783 | stat->hash = NULL; | |
493762fc SR |
784 | return -ENOMEM; |
785 | } | |
786 | ||
787 | return 0; | |
bac429f0 SR |
788 | } |
789 | ||
cafb168a SR |
790 | static int ftrace_profile_init(void) |
791 | { | |
792 | int cpu; | |
793 | int ret = 0; | |
794 | ||
c4602c1c | 795 | for_each_possible_cpu(cpu) { |
cafb168a SR |
796 | ret = ftrace_profile_init_cpu(cpu); |
797 | if (ret) | |
798 | break; | |
799 | } | |
800 | ||
801 | return ret; | |
802 | } | |
803 | ||
493762fc | 804 | /* interrupts must be disabled */ |
cafb168a SR |
805 | static struct ftrace_profile * |
806 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 807 | { |
493762fc | 808 | struct ftrace_profile *rec; |
bac429f0 | 809 | struct hlist_head *hhd; |
bac429f0 SR |
810 | unsigned long key; |
811 | ||
20079ebe | 812 | key = hash_long(ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 813 | hhd = &stat->hash[key]; |
bac429f0 SR |
814 | |
815 | if (hlist_empty(hhd)) | |
816 | return NULL; | |
817 | ||
1bb539ca | 818 | hlist_for_each_entry_rcu_notrace(rec, hhd, node) { |
bac429f0 | 819 | if (rec->ip == ip) |
493762fc SR |
820 | return rec; |
821 | } | |
822 | ||
823 | return NULL; | |
824 | } | |
825 | ||
cafb168a SR |
826 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
827 | struct ftrace_profile *rec) | |
493762fc SR |
828 | { |
829 | unsigned long key; | |
830 | ||
20079ebe | 831 | key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 832 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
833 | } |
834 | ||
318e0a73 SR |
835 | /* |
836 | * The memory is already allocated, this simply finds a new record to use. | |
837 | */ | |
493762fc | 838 | static struct ftrace_profile * |
318e0a73 | 839 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
840 | { |
841 | struct ftrace_profile *rec = NULL; | |
842 | ||
318e0a73 | 843 | /* prevent recursion (from NMIs) */ |
cafb168a | 844 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
845 | goto out; |
846 | ||
493762fc | 847 | /* |
318e0a73 SR |
848 | * Try to find the function again since an NMI |
849 | * could have added it | |
493762fc | 850 | */ |
cafb168a | 851 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 852 | if (rec) |
cafb168a | 853 | goto out; |
493762fc | 854 | |
cafb168a SR |
855 | if (stat->pages->index == PROFILES_PER_PAGE) { |
856 | if (!stat->pages->next) | |
857 | goto out; | |
858 | stat->pages = stat->pages->next; | |
bac429f0 | 859 | } |
493762fc | 860 | |
cafb168a | 861 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 862 | rec->ip = ip; |
cafb168a | 863 | ftrace_add_profile(stat, rec); |
493762fc | 864 | |
bac429f0 | 865 | out: |
cafb168a | 866 | atomic_dec(&stat->disabled); |
bac429f0 SR |
867 | |
868 | return rec; | |
869 | } | |
870 | ||
871 | static void | |
2f5f6ad9 | 872 | function_profile_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 873 | struct ftrace_ops *ops, struct pt_regs *regs) |
bac429f0 | 874 | { |
cafb168a | 875 | struct ftrace_profile_stat *stat; |
493762fc | 876 | struct ftrace_profile *rec; |
bac429f0 SR |
877 | unsigned long flags; |
878 | ||
879 | if (!ftrace_profile_enabled) | |
880 | return; | |
881 | ||
882 | local_irq_save(flags); | |
cafb168a | 883 | |
bdffd893 | 884 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 885 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
886 | goto out; |
887 | ||
888 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 889 | if (!rec) { |
318e0a73 | 890 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
891 | if (!rec) |
892 | goto out; | |
893 | } | |
bac429f0 SR |
894 | |
895 | rec->counter++; | |
896 | out: | |
897 | local_irq_restore(flags); | |
898 | } | |
899 | ||
0706f1c4 SR |
900 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
901 | static int profile_graph_entry(struct ftrace_graph_ent *trace) | |
902 | { | |
a1e2e31d | 903 | function_profile_call(trace->func, 0, NULL, NULL); |
0706f1c4 SR |
904 | return 1; |
905 | } | |
906 | ||
907 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
908 | { | |
cafb168a | 909 | struct ftrace_profile_stat *stat; |
a2a16d6a | 910 | unsigned long long calltime; |
0706f1c4 | 911 | struct ftrace_profile *rec; |
cafb168a | 912 | unsigned long flags; |
0706f1c4 SR |
913 | |
914 | local_irq_save(flags); | |
bdffd893 | 915 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 916 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
917 | goto out; |
918 | ||
37e44bc5 SR |
919 | /* If the calltime was zero'd ignore it */ |
920 | if (!trace->calltime) | |
921 | goto out; | |
922 | ||
a2a16d6a SR |
923 | calltime = trace->rettime - trace->calltime; |
924 | ||
55577204 | 925 | if (!fgraph_graph_time) { |
a2a16d6a SR |
926 | int index; |
927 | ||
928 | index = trace->depth; | |
929 | ||
930 | /* Append this call time to the parent time to subtract */ | |
931 | if (index) | |
932 | current->ret_stack[index - 1].subtime += calltime; | |
933 | ||
934 | if (current->ret_stack[index].subtime < calltime) | |
935 | calltime -= current->ret_stack[index].subtime; | |
936 | else | |
937 | calltime = 0; | |
938 | } | |
939 | ||
cafb168a | 940 | rec = ftrace_find_profiled_func(stat, trace->func); |
e330b3bc | 941 | if (rec) { |
a2a16d6a | 942 | rec->time += calltime; |
e330b3bc CD |
943 | rec->time_squared += calltime * calltime; |
944 | } | |
a2a16d6a | 945 | |
cafb168a | 946 | out: |
0706f1c4 SR |
947 | local_irq_restore(flags); |
948 | } | |
949 | ||
950 | static int register_ftrace_profiler(void) | |
951 | { | |
952 | return register_ftrace_graph(&profile_graph_return, | |
953 | &profile_graph_entry); | |
954 | } | |
955 | ||
956 | static void unregister_ftrace_profiler(void) | |
957 | { | |
958 | unregister_ftrace_graph(); | |
959 | } | |
960 | #else | |
bd38c0e6 | 961 | static struct ftrace_ops ftrace_profile_ops __read_mostly = { |
fb9fb015 | 962 | .func = function_profile_call, |
f04f24fb | 963 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, |
33b7f99c | 964 | INIT_OPS_HASH(ftrace_profile_ops) |
bac429f0 SR |
965 | }; |
966 | ||
0706f1c4 SR |
967 | static int register_ftrace_profiler(void) |
968 | { | |
969 | return register_ftrace_function(&ftrace_profile_ops); | |
970 | } | |
971 | ||
972 | static void unregister_ftrace_profiler(void) | |
973 | { | |
974 | unregister_ftrace_function(&ftrace_profile_ops); | |
975 | } | |
976 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
977 | ||
bac429f0 SR |
978 | static ssize_t |
979 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
980 | size_t cnt, loff_t *ppos) | |
981 | { | |
982 | unsigned long val; | |
bac429f0 SR |
983 | int ret; |
984 | ||
22fe9b54 PH |
985 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
986 | if (ret) | |
bac429f0 SR |
987 | return ret; |
988 | ||
989 | val = !!val; | |
990 | ||
991 | mutex_lock(&ftrace_profile_lock); | |
992 | if (ftrace_profile_enabled ^ val) { | |
993 | if (val) { | |
493762fc SR |
994 | ret = ftrace_profile_init(); |
995 | if (ret < 0) { | |
996 | cnt = ret; | |
997 | goto out; | |
998 | } | |
999 | ||
0706f1c4 SR |
1000 | ret = register_ftrace_profiler(); |
1001 | if (ret < 0) { | |
1002 | cnt = ret; | |
1003 | goto out; | |
1004 | } | |
bac429f0 SR |
1005 | ftrace_profile_enabled = 1; |
1006 | } else { | |
1007 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
1008 | /* |
1009 | * unregister_ftrace_profiler calls stop_machine | |
1010 | * so this acts like an synchronize_sched. | |
1011 | */ | |
0706f1c4 | 1012 | unregister_ftrace_profiler(); |
bac429f0 SR |
1013 | } |
1014 | } | |
493762fc | 1015 | out: |
bac429f0 SR |
1016 | mutex_unlock(&ftrace_profile_lock); |
1017 | ||
cf8517cf | 1018 | *ppos += cnt; |
bac429f0 SR |
1019 | |
1020 | return cnt; | |
1021 | } | |
1022 | ||
493762fc SR |
1023 | static ssize_t |
1024 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
1025 | size_t cnt, loff_t *ppos) | |
1026 | { | |
fb9fb015 | 1027 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
1028 | int r; |
1029 | ||
1030 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
1031 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
1032 | } | |
1033 | ||
bac429f0 SR |
1034 | static const struct file_operations ftrace_profile_fops = { |
1035 | .open = tracing_open_generic, | |
1036 | .read = ftrace_profile_read, | |
1037 | .write = ftrace_profile_write, | |
6038f373 | 1038 | .llseek = default_llseek, |
bac429f0 SR |
1039 | }; |
1040 | ||
cafb168a SR |
1041 | /* used to initialize the real stat files */ |
1042 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
1043 | .name = "functions", |
1044 | .stat_start = function_stat_start, | |
1045 | .stat_next = function_stat_next, | |
1046 | .stat_cmp = function_stat_cmp, | |
1047 | .stat_headers = function_stat_headers, | |
1048 | .stat_show = function_stat_show | |
cafb168a SR |
1049 | }; |
1050 | ||
8434dc93 | 1051 | static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
bac429f0 | 1052 | { |
cafb168a | 1053 | struct ftrace_profile_stat *stat; |
bac429f0 | 1054 | struct dentry *entry; |
cafb168a | 1055 | char *name; |
bac429f0 | 1056 | int ret; |
cafb168a SR |
1057 | int cpu; |
1058 | ||
1059 | for_each_possible_cpu(cpu) { | |
1060 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
1061 | ||
1062 | /* allocate enough for function name + cpu number */ | |
1063 | name = kmalloc(32, GFP_KERNEL); | |
1064 | if (!name) { | |
1065 | /* | |
1066 | * The files created are permanent, if something happens | |
1067 | * we still do not free memory. | |
1068 | */ | |
cafb168a SR |
1069 | WARN(1, |
1070 | "Could not allocate stat file for cpu %d\n", | |
1071 | cpu); | |
1072 | return; | |
1073 | } | |
1074 | stat->stat = function_stats; | |
1075 | snprintf(name, 32, "function%d", cpu); | |
1076 | stat->stat.name = name; | |
1077 | ret = register_stat_tracer(&stat->stat); | |
1078 | if (ret) { | |
1079 | WARN(1, | |
1080 | "Could not register function stat for cpu %d\n", | |
1081 | cpu); | |
1082 | kfree(name); | |
1083 | return; | |
1084 | } | |
bac429f0 SR |
1085 | } |
1086 | ||
8434dc93 | 1087 | entry = tracefs_create_file("function_profile_enabled", 0644, |
bac429f0 SR |
1088 | d_tracer, NULL, &ftrace_profile_fops); |
1089 | if (!entry) | |
8434dc93 | 1090 | pr_warning("Could not create tracefs " |
bac429f0 SR |
1091 | "'function_profile_enabled' entry\n"); |
1092 | } | |
1093 | ||
bac429f0 | 1094 | #else /* CONFIG_FUNCTION_PROFILER */ |
8434dc93 | 1095 | static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
bac429f0 SR |
1096 | { |
1097 | } | |
bac429f0 SR |
1098 | #endif /* CONFIG_FUNCTION_PROFILER */ |
1099 | ||
493762fc SR |
1100 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; |
1101 | ||
1619dc3f PA |
1102 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
1103 | static int ftrace_graph_active; | |
1104 | #else | |
1105 | # define ftrace_graph_active 0 | |
1106 | #endif | |
1107 | ||
493762fc SR |
1108 | #ifdef CONFIG_DYNAMIC_FTRACE |
1109 | ||
79922b80 SRRH |
1110 | static struct ftrace_ops *removed_ops; |
1111 | ||
e1effa01 SRRH |
1112 | /* |
1113 | * Set when doing a global update, like enabling all recs or disabling them. | |
1114 | * It is not set when just updating a single ftrace_ops. | |
1115 | */ | |
1116 | static bool update_all_ops; | |
1117 | ||
493762fc SR |
1118 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
1119 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
1120 | #endif | |
1121 | ||
1122 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; | |
1123 | ||
1124 | struct ftrace_func_probe { | |
1125 | struct hlist_node node; | |
1126 | struct ftrace_probe_ops *ops; | |
1127 | unsigned long flags; | |
1128 | unsigned long ip; | |
1129 | void *data; | |
7818b388 | 1130 | struct list_head free_list; |
493762fc SR |
1131 | }; |
1132 | ||
b448c4e3 SR |
1133 | struct ftrace_func_entry { |
1134 | struct hlist_node hlist; | |
1135 | unsigned long ip; | |
1136 | }; | |
1137 | ||
1138 | struct ftrace_hash { | |
1139 | unsigned long size_bits; | |
1140 | struct hlist_head *buckets; | |
1141 | unsigned long count; | |
07fd5515 | 1142 | struct rcu_head rcu; |
b448c4e3 SR |
1143 | }; |
1144 | ||
33dc9b12 SR |
1145 | /* |
1146 | * We make these constant because no one should touch them, | |
1147 | * but they are used as the default "empty hash", to avoid allocating | |
1148 | * it all the time. These are in a read only section such that if | |
1149 | * anyone does try to modify it, it will cause an exception. | |
1150 | */ | |
1151 | static const struct hlist_head empty_buckets[1]; | |
1152 | static const struct ftrace_hash empty_hash = { | |
1153 | .buckets = (struct hlist_head *)empty_buckets, | |
1cf41dd7 | 1154 | }; |
33dc9b12 | 1155 | #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash) |
493762fc | 1156 | |
2b499381 | 1157 | static struct ftrace_ops global_ops = { |
33b7f99c SRRH |
1158 | .func = ftrace_stub, |
1159 | .local_hash.notrace_hash = EMPTY_HASH, | |
1160 | .local_hash.filter_hash = EMPTY_HASH, | |
1161 | INIT_OPS_HASH(global_ops) | |
1162 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | | |
e3eea140 SRRH |
1163 | FTRACE_OPS_FL_INITIALIZED | |
1164 | FTRACE_OPS_FL_PID, | |
f45948e8 SR |
1165 | }; |
1166 | ||
aec0be2d SRRH |
1167 | /* |
1168 | * This is used by __kernel_text_address() to return true if the | |
0af26492 | 1169 | * address is on a dynamically allocated trampoline that would |
aec0be2d SRRH |
1170 | * not return true for either core_kernel_text() or |
1171 | * is_module_text_address(). | |
1172 | */ | |
1173 | bool is_ftrace_trampoline(unsigned long addr) | |
1174 | { | |
1175 | struct ftrace_ops *op; | |
1176 | bool ret = false; | |
1177 | ||
1178 | /* | |
1179 | * Some of the ops may be dynamically allocated, | |
1180 | * they are freed after a synchronize_sched(). | |
1181 | */ | |
1182 | preempt_disable_notrace(); | |
1183 | ||
1184 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1185 | /* | |
1186 | * This is to check for dynamically allocated trampolines. | |
1187 | * Trampolines that are in kernel text will have | |
1188 | * core_kernel_text() return true. | |
1189 | */ | |
1190 | if (op->trampoline && op->trampoline_size) | |
1191 | if (addr >= op->trampoline && | |
1192 | addr < op->trampoline + op->trampoline_size) { | |
1193 | ret = true; | |
1194 | goto out; | |
1195 | } | |
1196 | } while_for_each_ftrace_op(op); | |
1197 | ||
1198 | out: | |
1199 | preempt_enable_notrace(); | |
1200 | ||
1201 | return ret; | |
1202 | } | |
1203 | ||
493762fc SR |
1204 | struct ftrace_page { |
1205 | struct ftrace_page *next; | |
a7900875 | 1206 | struct dyn_ftrace *records; |
493762fc | 1207 | int index; |
a7900875 | 1208 | int size; |
493762fc SR |
1209 | }; |
1210 | ||
a7900875 SR |
1211 | #define ENTRY_SIZE sizeof(struct dyn_ftrace) |
1212 | #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE) | |
493762fc SR |
1213 | |
1214 | /* estimate from running different kernels */ | |
1215 | #define NR_TO_INIT 10000 | |
1216 | ||
1217 | static struct ftrace_page *ftrace_pages_start; | |
1218 | static struct ftrace_page *ftrace_pages; | |
1219 | ||
68f40969 | 1220 | static bool __always_inline ftrace_hash_empty(struct ftrace_hash *hash) |
06a51d93 SR |
1221 | { |
1222 | return !hash || !hash->count; | |
1223 | } | |
1224 | ||
b448c4e3 SR |
1225 | static struct ftrace_func_entry * |
1226 | ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
1227 | { | |
1228 | unsigned long key; | |
1229 | struct ftrace_func_entry *entry; | |
1230 | struct hlist_head *hhd; | |
b448c4e3 | 1231 | |
06a51d93 | 1232 | if (ftrace_hash_empty(hash)) |
b448c4e3 SR |
1233 | return NULL; |
1234 | ||
1235 | if (hash->size_bits > 0) | |
1236 | key = hash_long(ip, hash->size_bits); | |
1237 | else | |
1238 | key = 0; | |
1239 | ||
1240 | hhd = &hash->buckets[key]; | |
1241 | ||
1bb539ca | 1242 | hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) { |
b448c4e3 SR |
1243 | if (entry->ip == ip) |
1244 | return entry; | |
1245 | } | |
1246 | return NULL; | |
1247 | } | |
1248 | ||
33dc9b12 SR |
1249 | static void __add_hash_entry(struct ftrace_hash *hash, |
1250 | struct ftrace_func_entry *entry) | |
b448c4e3 | 1251 | { |
b448c4e3 SR |
1252 | struct hlist_head *hhd; |
1253 | unsigned long key; | |
1254 | ||
b448c4e3 | 1255 | if (hash->size_bits) |
33dc9b12 | 1256 | key = hash_long(entry->ip, hash->size_bits); |
b448c4e3 SR |
1257 | else |
1258 | key = 0; | |
1259 | ||
b448c4e3 SR |
1260 | hhd = &hash->buckets[key]; |
1261 | hlist_add_head(&entry->hlist, hhd); | |
1262 | hash->count++; | |
33dc9b12 SR |
1263 | } |
1264 | ||
1265 | static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip) | |
1266 | { | |
1267 | struct ftrace_func_entry *entry; | |
1268 | ||
1269 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1270 | if (!entry) | |
1271 | return -ENOMEM; | |
1272 | ||
1273 | entry->ip = ip; | |
1274 | __add_hash_entry(hash, entry); | |
b448c4e3 SR |
1275 | |
1276 | return 0; | |
1277 | } | |
1278 | ||
1279 | static void | |
33dc9b12 | 1280 | free_hash_entry(struct ftrace_hash *hash, |
b448c4e3 SR |
1281 | struct ftrace_func_entry *entry) |
1282 | { | |
1283 | hlist_del(&entry->hlist); | |
1284 | kfree(entry); | |
1285 | hash->count--; | |
1286 | } | |
1287 | ||
33dc9b12 SR |
1288 | static void |
1289 | remove_hash_entry(struct ftrace_hash *hash, | |
1290 | struct ftrace_func_entry *entry) | |
1291 | { | |
1292 | hlist_del(&entry->hlist); | |
1293 | hash->count--; | |
1294 | } | |
1295 | ||
b448c4e3 SR |
1296 | static void ftrace_hash_clear(struct ftrace_hash *hash) |
1297 | { | |
1298 | struct hlist_head *hhd; | |
b67bfe0d | 1299 | struct hlist_node *tn; |
b448c4e3 SR |
1300 | struct ftrace_func_entry *entry; |
1301 | int size = 1 << hash->size_bits; | |
1302 | int i; | |
1303 | ||
33dc9b12 SR |
1304 | if (!hash->count) |
1305 | return; | |
1306 | ||
b448c4e3 SR |
1307 | for (i = 0; i < size; i++) { |
1308 | hhd = &hash->buckets[i]; | |
b67bfe0d | 1309 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) |
33dc9b12 | 1310 | free_hash_entry(hash, entry); |
b448c4e3 SR |
1311 | } |
1312 | FTRACE_WARN_ON(hash->count); | |
1313 | } | |
1314 | ||
33dc9b12 SR |
1315 | static void free_ftrace_hash(struct ftrace_hash *hash) |
1316 | { | |
1317 | if (!hash || hash == EMPTY_HASH) | |
1318 | return; | |
1319 | ftrace_hash_clear(hash); | |
1320 | kfree(hash->buckets); | |
1321 | kfree(hash); | |
1322 | } | |
1323 | ||
07fd5515 SR |
1324 | static void __free_ftrace_hash_rcu(struct rcu_head *rcu) |
1325 | { | |
1326 | struct ftrace_hash *hash; | |
1327 | ||
1328 | hash = container_of(rcu, struct ftrace_hash, rcu); | |
1329 | free_ftrace_hash(hash); | |
1330 | } | |
1331 | ||
1332 | static void free_ftrace_hash_rcu(struct ftrace_hash *hash) | |
1333 | { | |
1334 | if (!hash || hash == EMPTY_HASH) | |
1335 | return; | |
1336 | call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu); | |
1337 | } | |
1338 | ||
5500fa51 JO |
1339 | void ftrace_free_filter(struct ftrace_ops *ops) |
1340 | { | |
f04f24fb | 1341 | ftrace_ops_init(ops); |
33b7f99c SRRH |
1342 | free_ftrace_hash(ops->func_hash->filter_hash); |
1343 | free_ftrace_hash(ops->func_hash->notrace_hash); | |
5500fa51 JO |
1344 | } |
1345 | ||
33dc9b12 SR |
1346 | static struct ftrace_hash *alloc_ftrace_hash(int size_bits) |
1347 | { | |
1348 | struct ftrace_hash *hash; | |
1349 | int size; | |
1350 | ||
1351 | hash = kzalloc(sizeof(*hash), GFP_KERNEL); | |
1352 | if (!hash) | |
1353 | return NULL; | |
1354 | ||
1355 | size = 1 << size_bits; | |
47b0edcb | 1356 | hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL); |
33dc9b12 SR |
1357 | |
1358 | if (!hash->buckets) { | |
1359 | kfree(hash); | |
1360 | return NULL; | |
1361 | } | |
1362 | ||
1363 | hash->size_bits = size_bits; | |
1364 | ||
1365 | return hash; | |
1366 | } | |
1367 | ||
1368 | static struct ftrace_hash * | |
1369 | alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) | |
1370 | { | |
1371 | struct ftrace_func_entry *entry; | |
1372 | struct ftrace_hash *new_hash; | |
33dc9b12 SR |
1373 | int size; |
1374 | int ret; | |
1375 | int i; | |
1376 | ||
1377 | new_hash = alloc_ftrace_hash(size_bits); | |
1378 | if (!new_hash) | |
1379 | return NULL; | |
1380 | ||
1381 | /* Empty hash? */ | |
06a51d93 | 1382 | if (ftrace_hash_empty(hash)) |
33dc9b12 SR |
1383 | return new_hash; |
1384 | ||
1385 | size = 1 << hash->size_bits; | |
1386 | for (i = 0; i < size; i++) { | |
b67bfe0d | 1387 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { |
33dc9b12 SR |
1388 | ret = add_hash_entry(new_hash, entry->ip); |
1389 | if (ret < 0) | |
1390 | goto free_hash; | |
1391 | } | |
1392 | } | |
1393 | ||
1394 | FTRACE_WARN_ON(new_hash->count != hash->count); | |
1395 | ||
1396 | return new_hash; | |
1397 | ||
1398 | free_hash: | |
1399 | free_ftrace_hash(new_hash); | |
1400 | return NULL; | |
1401 | } | |
1402 | ||
41fb61c2 | 1403 | static void |
84261912 | 1404 | ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash); |
41fb61c2 | 1405 | static void |
84261912 | 1406 | ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash); |
41fb61c2 | 1407 | |
f8b8be8a MH |
1408 | static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, |
1409 | struct ftrace_hash *new_hash); | |
1410 | ||
33dc9b12 | 1411 | static int |
41fb61c2 SR |
1412 | ftrace_hash_move(struct ftrace_ops *ops, int enable, |
1413 | struct ftrace_hash **dst, struct ftrace_hash *src) | |
33dc9b12 SR |
1414 | { |
1415 | struct ftrace_func_entry *entry; | |
b67bfe0d | 1416 | struct hlist_node *tn; |
33dc9b12 | 1417 | struct hlist_head *hhd; |
07fd5515 | 1418 | struct ftrace_hash *new_hash; |
33dc9b12 SR |
1419 | int size = src->count; |
1420 | int bits = 0; | |
f8b8be8a | 1421 | int ret; |
33dc9b12 SR |
1422 | int i; |
1423 | ||
f8b8be8a MH |
1424 | /* Reject setting notrace hash on IPMODIFY ftrace_ops */ |
1425 | if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable) | |
1426 | return -EINVAL; | |
1427 | ||
33dc9b12 SR |
1428 | /* |
1429 | * If the new source is empty, just free dst and assign it | |
1430 | * the empty_hash. | |
1431 | */ | |
1432 | if (!src->count) { | |
5c27c775 MH |
1433 | new_hash = EMPTY_HASH; |
1434 | goto update; | |
33dc9b12 SR |
1435 | } |
1436 | ||
33dc9b12 SR |
1437 | /* |
1438 | * Make the hash size about 1/2 the # found | |
1439 | */ | |
1440 | for (size /= 2; size; size >>= 1) | |
1441 | bits++; | |
1442 | ||
1443 | /* Don't allocate too much */ | |
1444 | if (bits > FTRACE_HASH_MAX_BITS) | |
1445 | bits = FTRACE_HASH_MAX_BITS; | |
1446 | ||
07fd5515 SR |
1447 | new_hash = alloc_ftrace_hash(bits); |
1448 | if (!new_hash) | |
5c27c775 | 1449 | return -ENOMEM; |
33dc9b12 SR |
1450 | |
1451 | size = 1 << src->size_bits; | |
1452 | for (i = 0; i < size; i++) { | |
1453 | hhd = &src->buckets[i]; | |
b67bfe0d | 1454 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) { |
33dc9b12 | 1455 | remove_hash_entry(src, entry); |
07fd5515 | 1456 | __add_hash_entry(new_hash, entry); |
33dc9b12 SR |
1457 | } |
1458 | } | |
1459 | ||
5c27c775 | 1460 | update: |
f8b8be8a MH |
1461 | /* Make sure this can be applied if it is IPMODIFY ftrace_ops */ |
1462 | if (enable) { | |
1463 | /* IPMODIFY should be updated only when filter_hash updating */ | |
1464 | ret = ftrace_hash_ipmodify_update(ops, new_hash); | |
1465 | if (ret < 0) { | |
1466 | free_ftrace_hash(new_hash); | |
1467 | return ret; | |
1468 | } | |
1469 | } | |
1470 | ||
5c27c775 MH |
1471 | /* |
1472 | * Remove the current set, update the hash and add | |
1473 | * them back. | |
1474 | */ | |
84261912 | 1475 | ftrace_hash_rec_disable_modify(ops, enable); |
5c27c775 | 1476 | |
07fd5515 | 1477 | rcu_assign_pointer(*dst, new_hash); |
07fd5515 | 1478 | |
84261912 | 1479 | ftrace_hash_rec_enable_modify(ops, enable); |
41fb61c2 | 1480 | |
5c27c775 | 1481 | return 0; |
33dc9b12 SR |
1482 | } |
1483 | ||
fef5aeee SRRH |
1484 | static bool hash_contains_ip(unsigned long ip, |
1485 | struct ftrace_ops_hash *hash) | |
1486 | { | |
1487 | /* | |
1488 | * The function record is a match if it exists in the filter | |
1489 | * hash and not in the notrace hash. Note, an emty hash is | |
1490 | * considered a match for the filter hash, but an empty | |
1491 | * notrace hash is considered not in the notrace hash. | |
1492 | */ | |
1493 | return (ftrace_hash_empty(hash->filter_hash) || | |
1494 | ftrace_lookup_ip(hash->filter_hash, ip)) && | |
1495 | (ftrace_hash_empty(hash->notrace_hash) || | |
1496 | !ftrace_lookup_ip(hash->notrace_hash, ip)); | |
1497 | } | |
1498 | ||
b848914c SR |
1499 | /* |
1500 | * Test the hashes for this ops to see if we want to call | |
1501 | * the ops->func or not. | |
1502 | * | |
1503 | * It's a match if the ip is in the ops->filter_hash or | |
1504 | * the filter_hash does not exist or is empty, | |
1505 | * AND | |
1506 | * the ip is not in the ops->notrace_hash. | |
cdbe61bf SR |
1507 | * |
1508 | * This needs to be called with preemption disabled as | |
1509 | * the hashes are freed with call_rcu_sched(). | |
b848914c SR |
1510 | */ |
1511 | static int | |
195a8afc | 1512 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
b848914c | 1513 | { |
fef5aeee | 1514 | struct ftrace_ops_hash hash; |
b848914c SR |
1515 | int ret; |
1516 | ||
195a8afc SRRH |
1517 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
1518 | /* | |
1519 | * There's a small race when adding ops that the ftrace handler | |
1520 | * that wants regs, may be called without them. We can not | |
1521 | * allow that handler to be called if regs is NULL. | |
1522 | */ | |
1523 | if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS)) | |
1524 | return 0; | |
1525 | #endif | |
1526 | ||
fef5aeee SRRH |
1527 | hash.filter_hash = rcu_dereference_raw_notrace(ops->func_hash->filter_hash); |
1528 | hash.notrace_hash = rcu_dereference_raw_notrace(ops->func_hash->notrace_hash); | |
b848914c | 1529 | |
fef5aeee | 1530 | if (hash_contains_ip(ip, &hash)) |
b848914c SR |
1531 | ret = 1; |
1532 | else | |
1533 | ret = 0; | |
b848914c SR |
1534 | |
1535 | return ret; | |
1536 | } | |
1537 | ||
493762fc SR |
1538 | /* |
1539 | * This is a double for. Do not use 'break' to break out of the loop, | |
1540 | * you must use a goto. | |
1541 | */ | |
1542 | #define do_for_each_ftrace_rec(pg, rec) \ | |
1543 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
1544 | int _____i; \ | |
1545 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
1546 | rec = &pg->records[_____i]; | |
1547 | ||
1548 | #define while_for_each_ftrace_rec() \ | |
1549 | } \ | |
1550 | } | |
1551 | ||
5855fead SR |
1552 | |
1553 | static int ftrace_cmp_recs(const void *a, const void *b) | |
1554 | { | |
a650e02a SR |
1555 | const struct dyn_ftrace *key = a; |
1556 | const struct dyn_ftrace *rec = b; | |
5855fead | 1557 | |
a650e02a | 1558 | if (key->flags < rec->ip) |
5855fead | 1559 | return -1; |
a650e02a SR |
1560 | if (key->ip >= rec->ip + MCOUNT_INSN_SIZE) |
1561 | return 1; | |
5855fead SR |
1562 | return 0; |
1563 | } | |
1564 | ||
f0cf973a | 1565 | static unsigned long ftrace_location_range(unsigned long start, unsigned long end) |
c88fd863 SR |
1566 | { |
1567 | struct ftrace_page *pg; | |
1568 | struct dyn_ftrace *rec; | |
5855fead | 1569 | struct dyn_ftrace key; |
c88fd863 | 1570 | |
a650e02a SR |
1571 | key.ip = start; |
1572 | key.flags = end; /* overload flags, as it is unsigned long */ | |
5855fead SR |
1573 | |
1574 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
a650e02a SR |
1575 | if (end < pg->records[0].ip || |
1576 | start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) | |
9644302e | 1577 | continue; |
5855fead SR |
1578 | rec = bsearch(&key, pg->records, pg->index, |
1579 | sizeof(struct dyn_ftrace), | |
1580 | ftrace_cmp_recs); | |
1581 | if (rec) | |
f0cf973a | 1582 | return rec->ip; |
5855fead | 1583 | } |
c88fd863 SR |
1584 | |
1585 | return 0; | |
1586 | } | |
1587 | ||
a650e02a SR |
1588 | /** |
1589 | * ftrace_location - return true if the ip giving is a traced location | |
1590 | * @ip: the instruction pointer to check | |
1591 | * | |
f0cf973a | 1592 | * Returns rec->ip if @ip given is a pointer to a ftrace location. |
a650e02a SR |
1593 | * That is, the instruction that is either a NOP or call to |
1594 | * the function tracer. It checks the ftrace internal tables to | |
1595 | * determine if the address belongs or not. | |
1596 | */ | |
f0cf973a | 1597 | unsigned long ftrace_location(unsigned long ip) |
a650e02a SR |
1598 | { |
1599 | return ftrace_location_range(ip, ip); | |
1600 | } | |
1601 | ||
1602 | /** | |
1603 | * ftrace_text_reserved - return true if range contains an ftrace location | |
1604 | * @start: start of range to search | |
1605 | * @end: end of range to search (inclusive). @end points to the last byte to check. | |
1606 | * | |
1607 | * Returns 1 if @start and @end contains a ftrace location. | |
1608 | * That is, the instruction that is either a NOP or call to | |
1609 | * the function tracer. It checks the ftrace internal tables to | |
1610 | * determine if the address belongs or not. | |
1611 | */ | |
d88471cb | 1612 | int ftrace_text_reserved(const void *start, const void *end) |
a650e02a | 1613 | { |
f0cf973a SR |
1614 | unsigned long ret; |
1615 | ||
1616 | ret = ftrace_location_range((unsigned long)start, | |
1617 | (unsigned long)end); | |
1618 | ||
1619 | return (int)!!ret; | |
a650e02a SR |
1620 | } |
1621 | ||
4fbb48cb SRRH |
1622 | /* Test if ops registered to this rec needs regs */ |
1623 | static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec) | |
1624 | { | |
1625 | struct ftrace_ops *ops; | |
1626 | bool keep_regs = false; | |
1627 | ||
1628 | for (ops = ftrace_ops_list; | |
1629 | ops != &ftrace_list_end; ops = ops->next) { | |
1630 | /* pass rec in as regs to have non-NULL val */ | |
1631 | if (ftrace_ops_test(ops, rec->ip, rec)) { | |
1632 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1633 | keep_regs = true; | |
1634 | break; | |
1635 | } | |
1636 | } | |
1637 | } | |
1638 | ||
1639 | return keep_regs; | |
1640 | } | |
1641 | ||
ed926f9b SR |
1642 | static void __ftrace_hash_rec_update(struct ftrace_ops *ops, |
1643 | int filter_hash, | |
1644 | bool inc) | |
1645 | { | |
1646 | struct ftrace_hash *hash; | |
1647 | struct ftrace_hash *other_hash; | |
1648 | struct ftrace_page *pg; | |
1649 | struct dyn_ftrace *rec; | |
1650 | int count = 0; | |
1651 | int all = 0; | |
1652 | ||
1653 | /* Only update if the ops has been registered */ | |
1654 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
1655 | return; | |
1656 | ||
1657 | /* | |
1658 | * In the filter_hash case: | |
1659 | * If the count is zero, we update all records. | |
1660 | * Otherwise we just update the items in the hash. | |
1661 | * | |
1662 | * In the notrace_hash case: | |
1663 | * We enable the update in the hash. | |
1664 | * As disabling notrace means enabling the tracing, | |
1665 | * and enabling notrace means disabling, the inc variable | |
1666 | * gets inversed. | |
1667 | */ | |
1668 | if (filter_hash) { | |
33b7f99c SRRH |
1669 | hash = ops->func_hash->filter_hash; |
1670 | other_hash = ops->func_hash->notrace_hash; | |
06a51d93 | 1671 | if (ftrace_hash_empty(hash)) |
ed926f9b SR |
1672 | all = 1; |
1673 | } else { | |
1674 | inc = !inc; | |
33b7f99c SRRH |
1675 | hash = ops->func_hash->notrace_hash; |
1676 | other_hash = ops->func_hash->filter_hash; | |
ed926f9b SR |
1677 | /* |
1678 | * If the notrace hash has no items, | |
1679 | * then there's nothing to do. | |
1680 | */ | |
06a51d93 | 1681 | if (ftrace_hash_empty(hash)) |
ed926f9b SR |
1682 | return; |
1683 | } | |
1684 | ||
1685 | do_for_each_ftrace_rec(pg, rec) { | |
1686 | int in_other_hash = 0; | |
1687 | int in_hash = 0; | |
1688 | int match = 0; | |
1689 | ||
1690 | if (all) { | |
1691 | /* | |
1692 | * Only the filter_hash affects all records. | |
1693 | * Update if the record is not in the notrace hash. | |
1694 | */ | |
b848914c | 1695 | if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) |
ed926f9b SR |
1696 | match = 1; |
1697 | } else { | |
06a51d93 SR |
1698 | in_hash = !!ftrace_lookup_ip(hash, rec->ip); |
1699 | in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip); | |
ed926f9b SR |
1700 | |
1701 | /* | |
19eab4a4 SRRH |
1702 | * If filter_hash is set, we want to match all functions |
1703 | * that are in the hash but not in the other hash. | |
ed926f9b | 1704 | * |
19eab4a4 SRRH |
1705 | * If filter_hash is not set, then we are decrementing. |
1706 | * That means we match anything that is in the hash | |
1707 | * and also in the other_hash. That is, we need to turn | |
1708 | * off functions in the other hash because they are disabled | |
1709 | * by this hash. | |
ed926f9b SR |
1710 | */ |
1711 | if (filter_hash && in_hash && !in_other_hash) | |
1712 | match = 1; | |
1713 | else if (!filter_hash && in_hash && | |
06a51d93 | 1714 | (in_other_hash || ftrace_hash_empty(other_hash))) |
ed926f9b SR |
1715 | match = 1; |
1716 | } | |
1717 | if (!match) | |
1718 | continue; | |
1719 | ||
1720 | if (inc) { | |
1721 | rec->flags++; | |
0376bde1 | 1722 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX)) |
ed926f9b | 1723 | return; |
79922b80 SRRH |
1724 | |
1725 | /* | |
1726 | * If there's only a single callback registered to a | |
1727 | * function, and the ops has a trampoline registered | |
1728 | * for it, then we can call it directly. | |
1729 | */ | |
fef5aeee | 1730 | if (ftrace_rec_count(rec) == 1 && ops->trampoline) |
79922b80 | 1731 | rec->flags |= FTRACE_FL_TRAMP; |
fef5aeee | 1732 | else |
79922b80 SRRH |
1733 | /* |
1734 | * If we are adding another function callback | |
1735 | * to this function, and the previous had a | |
bce0b6c5 SRRH |
1736 | * custom trampoline in use, then we need to go |
1737 | * back to the default trampoline. | |
79922b80 | 1738 | */ |
fef5aeee | 1739 | rec->flags &= ~FTRACE_FL_TRAMP; |
79922b80 | 1740 | |
08f6fba5 SR |
1741 | /* |
1742 | * If any ops wants regs saved for this function | |
1743 | * then all ops will get saved regs. | |
1744 | */ | |
1745 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) | |
1746 | rec->flags |= FTRACE_FL_REGS; | |
ed926f9b | 1747 | } else { |
0376bde1 | 1748 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0)) |
ed926f9b SR |
1749 | return; |
1750 | rec->flags--; | |
79922b80 | 1751 | |
4fbb48cb SRRH |
1752 | /* |
1753 | * If the rec had REGS enabled and the ops that is | |
1754 | * being removed had REGS set, then see if there is | |
1755 | * still any ops for this record that wants regs. | |
1756 | * If not, we can stop recording them. | |
1757 | */ | |
0376bde1 | 1758 | if (ftrace_rec_count(rec) > 0 && |
4fbb48cb SRRH |
1759 | rec->flags & FTRACE_FL_REGS && |
1760 | ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1761 | if (!test_rec_ops_needs_regs(rec)) | |
1762 | rec->flags &= ~FTRACE_FL_REGS; | |
1763 | } | |
79922b80 | 1764 | |
fef5aeee SRRH |
1765 | /* |
1766 | * If the rec had TRAMP enabled, then it needs to | |
1767 | * be cleared. As TRAMP can only be enabled iff | |
1768 | * there is only a single ops attached to it. | |
1769 | * In otherwords, always disable it on decrementing. | |
1770 | * In the future, we may set it if rec count is | |
1771 | * decremented to one, and the ops that is left | |
1772 | * has a trampoline. | |
1773 | */ | |
1774 | rec->flags &= ~FTRACE_FL_TRAMP; | |
1775 | ||
79922b80 SRRH |
1776 | /* |
1777 | * flags will be cleared in ftrace_check_record() | |
1778 | * if rec count is zero. | |
1779 | */ | |
ed926f9b SR |
1780 | } |
1781 | count++; | |
1782 | /* Shortcut, if we handled all records, we are done. */ | |
1783 | if (!all && count == hash->count) | |
1784 | return; | |
1785 | } while_for_each_ftrace_rec(); | |
1786 | } | |
1787 | ||
1788 | static void ftrace_hash_rec_disable(struct ftrace_ops *ops, | |
1789 | int filter_hash) | |
1790 | { | |
1791 | __ftrace_hash_rec_update(ops, filter_hash, 0); | |
1792 | } | |
1793 | ||
1794 | static void ftrace_hash_rec_enable(struct ftrace_ops *ops, | |
1795 | int filter_hash) | |
1796 | { | |
1797 | __ftrace_hash_rec_update(ops, filter_hash, 1); | |
1798 | } | |
1799 | ||
84261912 SRRH |
1800 | static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops, |
1801 | int filter_hash, int inc) | |
1802 | { | |
1803 | struct ftrace_ops *op; | |
1804 | ||
1805 | __ftrace_hash_rec_update(ops, filter_hash, inc); | |
1806 | ||
1807 | if (ops->func_hash != &global_ops.local_hash) | |
1808 | return; | |
1809 | ||
1810 | /* | |
1811 | * If the ops shares the global_ops hash, then we need to update | |
1812 | * all ops that are enabled and use this hash. | |
1813 | */ | |
1814 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1815 | /* Already done */ | |
1816 | if (op == ops) | |
1817 | continue; | |
1818 | if (op->func_hash == &global_ops.local_hash) | |
1819 | __ftrace_hash_rec_update(op, filter_hash, inc); | |
1820 | } while_for_each_ftrace_op(op); | |
1821 | } | |
1822 | ||
1823 | static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, | |
1824 | int filter_hash) | |
1825 | { | |
1826 | ftrace_hash_rec_update_modify(ops, filter_hash, 0); | |
1827 | } | |
1828 | ||
1829 | static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, | |
1830 | int filter_hash) | |
1831 | { | |
1832 | ftrace_hash_rec_update_modify(ops, filter_hash, 1); | |
1833 | } | |
1834 | ||
f8b8be8a MH |
1835 | /* |
1836 | * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK | |
1837 | * or no-needed to update, -EBUSY if it detects a conflict of the flag | |
1838 | * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs. | |
1839 | * Note that old_hash and new_hash has below meanings | |
1840 | * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected) | |
1841 | * - If the hash is EMPTY_HASH, it hits nothing | |
1842 | * - Anything else hits the recs which match the hash entries. | |
1843 | */ | |
1844 | static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops, | |
1845 | struct ftrace_hash *old_hash, | |
1846 | struct ftrace_hash *new_hash) | |
1847 | { | |
1848 | struct ftrace_page *pg; | |
1849 | struct dyn_ftrace *rec, *end = NULL; | |
1850 | int in_old, in_new; | |
1851 | ||
1852 | /* Only update if the ops has been registered */ | |
1853 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
1854 | return 0; | |
1855 | ||
1856 | if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY)) | |
1857 | return 0; | |
1858 | ||
1859 | /* | |
1860 | * Since the IPMODIFY is a very address sensitive action, we do not | |
1861 | * allow ftrace_ops to set all functions to new hash. | |
1862 | */ | |
1863 | if (!new_hash || !old_hash) | |
1864 | return -EINVAL; | |
1865 | ||
1866 | /* Update rec->flags */ | |
1867 | do_for_each_ftrace_rec(pg, rec) { | |
1868 | /* We need to update only differences of filter_hash */ | |
1869 | in_old = !!ftrace_lookup_ip(old_hash, rec->ip); | |
1870 | in_new = !!ftrace_lookup_ip(new_hash, rec->ip); | |
1871 | if (in_old == in_new) | |
1872 | continue; | |
1873 | ||
1874 | if (in_new) { | |
1875 | /* New entries must ensure no others are using it */ | |
1876 | if (rec->flags & FTRACE_FL_IPMODIFY) | |
1877 | goto rollback; | |
1878 | rec->flags |= FTRACE_FL_IPMODIFY; | |
1879 | } else /* Removed entry */ | |
1880 | rec->flags &= ~FTRACE_FL_IPMODIFY; | |
1881 | } while_for_each_ftrace_rec(); | |
1882 | ||
1883 | return 0; | |
1884 | ||
1885 | rollback: | |
1886 | end = rec; | |
1887 | ||
1888 | /* Roll back what we did above */ | |
1889 | do_for_each_ftrace_rec(pg, rec) { | |
1890 | if (rec == end) | |
1891 | goto err_out; | |
1892 | ||
1893 | in_old = !!ftrace_lookup_ip(old_hash, rec->ip); | |
1894 | in_new = !!ftrace_lookup_ip(new_hash, rec->ip); | |
1895 | if (in_old == in_new) | |
1896 | continue; | |
1897 | ||
1898 | if (in_new) | |
1899 | rec->flags &= ~FTRACE_FL_IPMODIFY; | |
1900 | else | |
1901 | rec->flags |= FTRACE_FL_IPMODIFY; | |
1902 | } while_for_each_ftrace_rec(); | |
1903 | ||
1904 | err_out: | |
1905 | return -EBUSY; | |
1906 | } | |
1907 | ||
1908 | static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops) | |
1909 | { | |
1910 | struct ftrace_hash *hash = ops->func_hash->filter_hash; | |
1911 | ||
1912 | if (ftrace_hash_empty(hash)) | |
1913 | hash = NULL; | |
1914 | ||
1915 | return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash); | |
1916 | } | |
1917 | ||
1918 | /* Disabling always succeeds */ | |
1919 | static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops) | |
1920 | { | |
1921 | struct ftrace_hash *hash = ops->func_hash->filter_hash; | |
1922 | ||
1923 | if (ftrace_hash_empty(hash)) | |
1924 | hash = NULL; | |
1925 | ||
1926 | __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH); | |
1927 | } | |
1928 | ||
1929 | static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, | |
1930 | struct ftrace_hash *new_hash) | |
1931 | { | |
1932 | struct ftrace_hash *old_hash = ops->func_hash->filter_hash; | |
1933 | ||
1934 | if (ftrace_hash_empty(old_hash)) | |
1935 | old_hash = NULL; | |
1936 | ||
1937 | if (ftrace_hash_empty(new_hash)) | |
1938 | new_hash = NULL; | |
1939 | ||
1940 | return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash); | |
1941 | } | |
1942 | ||
b17e8a37 SR |
1943 | static void print_ip_ins(const char *fmt, unsigned char *p) |
1944 | { | |
1945 | int i; | |
1946 | ||
1947 | printk(KERN_CONT "%s", fmt); | |
1948 | ||
1949 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
1950 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
1951 | } | |
1952 | ||
4fd3279b SRRH |
1953 | static struct ftrace_ops * |
1954 | ftrace_find_tramp_ops_any(struct dyn_ftrace *rec); | |
1955 | ||
c88fd863 SR |
1956 | /** |
1957 | * ftrace_bug - report and shutdown function tracer | |
1958 | * @failed: The failed type (EFAULT, EINVAL, EPERM) | |
4fd3279b | 1959 | * @rec: The record that failed |
c88fd863 SR |
1960 | * |
1961 | * The arch code that enables or disables the function tracing | |
1962 | * can call ftrace_bug() when it has detected a problem in | |
1963 | * modifying the code. @failed should be one of either: | |
1964 | * EFAULT - if the problem happens on reading the @ip address | |
1965 | * EINVAL - if what is read at @ip is not what was expected | |
1966 | * EPERM - if the problem happens on writting to the @ip address | |
1967 | */ | |
4fd3279b | 1968 | void ftrace_bug(int failed, struct dyn_ftrace *rec) |
b17e8a37 | 1969 | { |
4fd3279b SRRH |
1970 | unsigned long ip = rec ? rec->ip : 0; |
1971 | ||
b17e8a37 SR |
1972 | switch (failed) { |
1973 | case -EFAULT: | |
1974 | FTRACE_WARN_ON_ONCE(1); | |
1975 | pr_info("ftrace faulted on modifying "); | |
1976 | print_ip_sym(ip); | |
1977 | break; | |
1978 | case -EINVAL: | |
1979 | FTRACE_WARN_ON_ONCE(1); | |
1980 | pr_info("ftrace failed to modify "); | |
1981 | print_ip_sym(ip); | |
b17e8a37 | 1982 | print_ip_ins(" actual: ", (unsigned char *)ip); |
4fd3279b | 1983 | pr_cont("\n"); |
b17e8a37 SR |
1984 | break; |
1985 | case -EPERM: | |
1986 | FTRACE_WARN_ON_ONCE(1); | |
1987 | pr_info("ftrace faulted on writing "); | |
1988 | print_ip_sym(ip); | |
1989 | break; | |
1990 | default: | |
1991 | FTRACE_WARN_ON_ONCE(1); | |
1992 | pr_info("ftrace faulted on unknown error "); | |
1993 | print_ip_sym(ip); | |
1994 | } | |
4fd3279b SRRH |
1995 | if (rec) { |
1996 | struct ftrace_ops *ops = NULL; | |
1997 | ||
1998 | pr_info("ftrace record flags: %lx\n", rec->flags); | |
1999 | pr_cont(" (%ld)%s", ftrace_rec_count(rec), | |
2000 | rec->flags & FTRACE_FL_REGS ? " R" : " "); | |
2001 | if (rec->flags & FTRACE_FL_TRAMP_EN) { | |
2002 | ops = ftrace_find_tramp_ops_any(rec); | |
2003 | if (ops) | |
2004 | pr_cont("\ttramp: %pS", | |
2005 | (void *)ops->trampoline); | |
2006 | else | |
2007 | pr_cont("\ttramp: ERROR!"); | |
2008 | ||
2009 | } | |
2010 | ip = ftrace_get_addr_curr(rec); | |
2011 | pr_cont(" expected tramp: %lx\n", ip); | |
2012 | } | |
b17e8a37 SR |
2013 | } |
2014 | ||
c88fd863 | 2015 | static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update) |
5072c59f | 2016 | { |
64fbcd16 | 2017 | unsigned long flag = 0UL; |
e7d3737e | 2018 | |
982c350b | 2019 | /* |
30fb6aa7 | 2020 | * If we are updating calls: |
982c350b | 2021 | * |
ed926f9b SR |
2022 | * If the record has a ref count, then we need to enable it |
2023 | * because someone is using it. | |
982c350b | 2024 | * |
ed926f9b SR |
2025 | * Otherwise we make sure its disabled. |
2026 | * | |
30fb6aa7 | 2027 | * If we are disabling calls, then disable all records that |
ed926f9b | 2028 | * are enabled. |
982c350b | 2029 | */ |
0376bde1 | 2030 | if (enable && ftrace_rec_count(rec)) |
ed926f9b | 2031 | flag = FTRACE_FL_ENABLED; |
982c350b | 2032 | |
08f6fba5 | 2033 | /* |
79922b80 SRRH |
2034 | * If enabling and the REGS flag does not match the REGS_EN, or |
2035 | * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore | |
2036 | * this record. Set flags to fail the compare against ENABLED. | |
08f6fba5 | 2037 | */ |
79922b80 SRRH |
2038 | if (flag) { |
2039 | if (!(rec->flags & FTRACE_FL_REGS) != | |
2040 | !(rec->flags & FTRACE_FL_REGS_EN)) | |
2041 | flag |= FTRACE_FL_REGS; | |
2042 | ||
2043 | if (!(rec->flags & FTRACE_FL_TRAMP) != | |
2044 | !(rec->flags & FTRACE_FL_TRAMP_EN)) | |
2045 | flag |= FTRACE_FL_TRAMP; | |
2046 | } | |
08f6fba5 | 2047 | |
64fbcd16 XG |
2048 | /* If the state of this record hasn't changed, then do nothing */ |
2049 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
c88fd863 | 2050 | return FTRACE_UPDATE_IGNORE; |
982c350b | 2051 | |
64fbcd16 | 2052 | if (flag) { |
08f6fba5 SR |
2053 | /* Save off if rec is being enabled (for return value) */ |
2054 | flag ^= rec->flags & FTRACE_FL_ENABLED; | |
2055 | ||
2056 | if (update) { | |
c88fd863 | 2057 | rec->flags |= FTRACE_FL_ENABLED; |
08f6fba5 SR |
2058 | if (flag & FTRACE_FL_REGS) { |
2059 | if (rec->flags & FTRACE_FL_REGS) | |
2060 | rec->flags |= FTRACE_FL_REGS_EN; | |
2061 | else | |
2062 | rec->flags &= ~FTRACE_FL_REGS_EN; | |
2063 | } | |
79922b80 SRRH |
2064 | if (flag & FTRACE_FL_TRAMP) { |
2065 | if (rec->flags & FTRACE_FL_TRAMP) | |
2066 | rec->flags |= FTRACE_FL_TRAMP_EN; | |
2067 | else | |
2068 | rec->flags &= ~FTRACE_FL_TRAMP_EN; | |
2069 | } | |
08f6fba5 SR |
2070 | } |
2071 | ||
2072 | /* | |
2073 | * If this record is being updated from a nop, then | |
2074 | * return UPDATE_MAKE_CALL. | |
08f6fba5 SR |
2075 | * Otherwise, |
2076 | * return UPDATE_MODIFY_CALL to tell the caller to convert | |
f1b2f2bd | 2077 | * from the save regs, to a non-save regs function or |
79922b80 | 2078 | * vice versa, or from a trampoline call. |
08f6fba5 SR |
2079 | */ |
2080 | if (flag & FTRACE_FL_ENABLED) | |
2081 | return FTRACE_UPDATE_MAKE_CALL; | |
f1b2f2bd SRRH |
2082 | |
2083 | return FTRACE_UPDATE_MODIFY_CALL; | |
c88fd863 SR |
2084 | } |
2085 | ||
08f6fba5 SR |
2086 | if (update) { |
2087 | /* If there's no more users, clear all flags */ | |
0376bde1 | 2088 | if (!ftrace_rec_count(rec)) |
08f6fba5 SR |
2089 | rec->flags = 0; |
2090 | else | |
b24d443b SRRH |
2091 | /* |
2092 | * Just disable the record, but keep the ops TRAMP | |
2093 | * and REGS states. The _EN flags must be disabled though. | |
2094 | */ | |
2095 | rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN | | |
2096 | FTRACE_FL_REGS_EN); | |
08f6fba5 | 2097 | } |
c88fd863 SR |
2098 | |
2099 | return FTRACE_UPDATE_MAKE_NOP; | |
2100 | } | |
2101 | ||
2102 | /** | |
2103 | * ftrace_update_record, set a record that now is tracing or not | |
2104 | * @rec: the record to update | |
2105 | * @enable: set to 1 if the record is tracing, zero to force disable | |
2106 | * | |
2107 | * The records that represent all functions that can be traced need | |
2108 | * to be updated when tracing has been enabled. | |
2109 | */ | |
2110 | int ftrace_update_record(struct dyn_ftrace *rec, int enable) | |
2111 | { | |
2112 | return ftrace_check_record(rec, enable, 1); | |
2113 | } | |
2114 | ||
2115 | /** | |
2116 | * ftrace_test_record, check if the record has been enabled or not | |
2117 | * @rec: the record to test | |
2118 | * @enable: set to 1 to check if enabled, 0 if it is disabled | |
2119 | * | |
2120 | * The arch code may need to test if a record is already set to | |
2121 | * tracing to determine how to modify the function code that it | |
2122 | * represents. | |
2123 | */ | |
2124 | int ftrace_test_record(struct dyn_ftrace *rec, int enable) | |
2125 | { | |
2126 | return ftrace_check_record(rec, enable, 0); | |
2127 | } | |
2128 | ||
5fecaa04 SRRH |
2129 | static struct ftrace_ops * |
2130 | ftrace_find_tramp_ops_any(struct dyn_ftrace *rec) | |
2131 | { | |
2132 | struct ftrace_ops *op; | |
fef5aeee | 2133 | unsigned long ip = rec->ip; |
5fecaa04 SRRH |
2134 | |
2135 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2136 | ||
2137 | if (!op->trampoline) | |
2138 | continue; | |
2139 | ||
fef5aeee | 2140 | if (hash_contains_ip(ip, op->func_hash)) |
5fecaa04 SRRH |
2141 | return op; |
2142 | } while_for_each_ftrace_op(op); | |
2143 | ||
2144 | return NULL; | |
2145 | } | |
2146 | ||
79922b80 SRRH |
2147 | static struct ftrace_ops * |
2148 | ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec) | |
2149 | { | |
2150 | struct ftrace_ops *op; | |
fef5aeee | 2151 | unsigned long ip = rec->ip; |
79922b80 | 2152 | |
fef5aeee SRRH |
2153 | /* |
2154 | * Need to check removed ops first. | |
2155 | * If they are being removed, and this rec has a tramp, | |
2156 | * and this rec is in the ops list, then it would be the | |
2157 | * one with the tramp. | |
2158 | */ | |
2159 | if (removed_ops) { | |
2160 | if (hash_contains_ip(ip, &removed_ops->old_hash)) | |
79922b80 SRRH |
2161 | return removed_ops; |
2162 | } | |
2163 | ||
fef5aeee SRRH |
2164 | /* |
2165 | * Need to find the current trampoline for a rec. | |
2166 | * Now, a trampoline is only attached to a rec if there | |
2167 | * was a single 'ops' attached to it. But this can be called | |
2168 | * when we are adding another op to the rec or removing the | |
2169 | * current one. Thus, if the op is being added, we can | |
2170 | * ignore it because it hasn't attached itself to the rec | |
4fc40904 SRRH |
2171 | * yet. |
2172 | * | |
2173 | * If an ops is being modified (hooking to different functions) | |
2174 | * then we don't care about the new functions that are being | |
2175 | * added, just the old ones (that are probably being removed). | |
2176 | * | |
2177 | * If we are adding an ops to a function that already is using | |
2178 | * a trampoline, it needs to be removed (trampolines are only | |
2179 | * for single ops connected), then an ops that is not being | |
2180 | * modified also needs to be checked. | |
fef5aeee | 2181 | */ |
79922b80 | 2182 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
fef5aeee SRRH |
2183 | |
2184 | if (!op->trampoline) | |
2185 | continue; | |
2186 | ||
2187 | /* | |
2188 | * If the ops is being added, it hasn't gotten to | |
2189 | * the point to be removed from this tree yet. | |
2190 | */ | |
2191 | if (op->flags & FTRACE_OPS_FL_ADDING) | |
79922b80 SRRH |
2192 | continue; |
2193 | ||
4fc40904 | 2194 | |
fef5aeee | 2195 | /* |
4fc40904 SRRH |
2196 | * If the ops is being modified and is in the old |
2197 | * hash, then it is probably being removed from this | |
2198 | * function. | |
fef5aeee | 2199 | */ |
fef5aeee SRRH |
2200 | if ((op->flags & FTRACE_OPS_FL_MODIFYING) && |
2201 | hash_contains_ip(ip, &op->old_hash)) | |
79922b80 | 2202 | return op; |
4fc40904 SRRH |
2203 | /* |
2204 | * If the ops is not being added or modified, and it's | |
2205 | * in its normal filter hash, then this must be the one | |
2206 | * we want! | |
2207 | */ | |
2208 | if (!(op->flags & FTRACE_OPS_FL_MODIFYING) && | |
2209 | hash_contains_ip(ip, op->func_hash)) | |
2210 | return op; | |
79922b80 SRRH |
2211 | |
2212 | } while_for_each_ftrace_op(op); | |
2213 | ||
2214 | return NULL; | |
2215 | } | |
2216 | ||
2217 | static struct ftrace_ops * | |
2218 | ftrace_find_tramp_ops_new(struct dyn_ftrace *rec) | |
2219 | { | |
2220 | struct ftrace_ops *op; | |
fef5aeee | 2221 | unsigned long ip = rec->ip; |
79922b80 SRRH |
2222 | |
2223 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2224 | /* pass rec in as regs to have non-NULL val */ | |
fef5aeee | 2225 | if (hash_contains_ip(ip, op->func_hash)) |
79922b80 SRRH |
2226 | return op; |
2227 | } while_for_each_ftrace_op(op); | |
2228 | ||
2229 | return NULL; | |
2230 | } | |
2231 | ||
7413af1f SRRH |
2232 | /** |
2233 | * ftrace_get_addr_new - Get the call address to set to | |
2234 | * @rec: The ftrace record descriptor | |
2235 | * | |
2236 | * If the record has the FTRACE_FL_REGS set, that means that it | |
2237 | * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS | |
2238 | * is not not set, then it wants to convert to the normal callback. | |
2239 | * | |
2240 | * Returns the address of the trampoline to set to | |
2241 | */ | |
2242 | unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec) | |
2243 | { | |
79922b80 SRRH |
2244 | struct ftrace_ops *ops; |
2245 | ||
2246 | /* Trampolines take precedence over regs */ | |
2247 | if (rec->flags & FTRACE_FL_TRAMP) { | |
2248 | ops = ftrace_find_tramp_ops_new(rec); | |
2249 | if (FTRACE_WARN_ON(!ops || !ops->trampoline)) { | |
bce0b6c5 SRRH |
2250 | pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n", |
2251 | (void *)rec->ip, (void *)rec->ip, rec->flags); | |
79922b80 SRRH |
2252 | /* Ftrace is shutting down, return anything */ |
2253 | return (unsigned long)FTRACE_ADDR; | |
2254 | } | |
2255 | return ops->trampoline; | |
2256 | } | |
2257 | ||
7413af1f SRRH |
2258 | if (rec->flags & FTRACE_FL_REGS) |
2259 | return (unsigned long)FTRACE_REGS_ADDR; | |
2260 | else | |
2261 | return (unsigned long)FTRACE_ADDR; | |
2262 | } | |
2263 | ||
2264 | /** | |
2265 | * ftrace_get_addr_curr - Get the call address that is already there | |
2266 | * @rec: The ftrace record descriptor | |
2267 | * | |
2268 | * The FTRACE_FL_REGS_EN is set when the record already points to | |
2269 | * a function that saves all the regs. Basically the '_EN' version | |
2270 | * represents the current state of the function. | |
2271 | * | |
2272 | * Returns the address of the trampoline that is currently being called | |
2273 | */ | |
2274 | unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec) | |
2275 | { | |
79922b80 SRRH |
2276 | struct ftrace_ops *ops; |
2277 | ||
2278 | /* Trampolines take precedence over regs */ | |
2279 | if (rec->flags & FTRACE_FL_TRAMP_EN) { | |
2280 | ops = ftrace_find_tramp_ops_curr(rec); | |
2281 | if (FTRACE_WARN_ON(!ops)) { | |
2282 | pr_warning("Bad trampoline accounting at: %p (%pS)\n", | |
2283 | (void *)rec->ip, (void *)rec->ip); | |
2284 | /* Ftrace is shutting down, return anything */ | |
2285 | return (unsigned long)FTRACE_ADDR; | |
2286 | } | |
2287 | return ops->trampoline; | |
2288 | } | |
2289 | ||
7413af1f SRRH |
2290 | if (rec->flags & FTRACE_FL_REGS_EN) |
2291 | return (unsigned long)FTRACE_REGS_ADDR; | |
2292 | else | |
2293 | return (unsigned long)FTRACE_ADDR; | |
2294 | } | |
2295 | ||
c88fd863 SR |
2296 | static int |
2297 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) | |
2298 | { | |
08f6fba5 | 2299 | unsigned long ftrace_old_addr; |
c88fd863 SR |
2300 | unsigned long ftrace_addr; |
2301 | int ret; | |
2302 | ||
7c0868e0 | 2303 | ftrace_addr = ftrace_get_addr_new(rec); |
c88fd863 | 2304 | |
7c0868e0 SRRH |
2305 | /* This needs to be done before we call ftrace_update_record */ |
2306 | ftrace_old_addr = ftrace_get_addr_curr(rec); | |
2307 | ||
2308 | ret = ftrace_update_record(rec, enable); | |
08f6fba5 | 2309 | |
c88fd863 SR |
2310 | switch (ret) { |
2311 | case FTRACE_UPDATE_IGNORE: | |
2312 | return 0; | |
2313 | ||
2314 | case FTRACE_UPDATE_MAKE_CALL: | |
64fbcd16 | 2315 | return ftrace_make_call(rec, ftrace_addr); |
c88fd863 SR |
2316 | |
2317 | case FTRACE_UPDATE_MAKE_NOP: | |
39b5552c | 2318 | return ftrace_make_nop(NULL, rec, ftrace_old_addr); |
08f6fba5 | 2319 | |
08f6fba5 | 2320 | case FTRACE_UPDATE_MODIFY_CALL: |
08f6fba5 | 2321 | return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr); |
5072c59f SR |
2322 | } |
2323 | ||
c88fd863 | 2324 | return -1; /* unknow ftrace bug */ |
5072c59f SR |
2325 | } |
2326 | ||
e4f5d544 | 2327 | void __weak ftrace_replace_code(int enable) |
3c1720f0 | 2328 | { |
3c1720f0 SR |
2329 | struct dyn_ftrace *rec; |
2330 | struct ftrace_page *pg; | |
6a24a244 | 2331 | int failed; |
3c1720f0 | 2332 | |
45a4a237 SR |
2333 | if (unlikely(ftrace_disabled)) |
2334 | return; | |
2335 | ||
265c831c | 2336 | do_for_each_ftrace_rec(pg, rec) { |
e4f5d544 | 2337 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 2338 | if (failed) { |
4fd3279b | 2339 | ftrace_bug(failed, rec); |
3279ba37 SR |
2340 | /* Stop processing */ |
2341 | return; | |
3c1720f0 | 2342 | } |
265c831c | 2343 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
2344 | } |
2345 | ||
c88fd863 SR |
2346 | struct ftrace_rec_iter { |
2347 | struct ftrace_page *pg; | |
2348 | int index; | |
2349 | }; | |
2350 | ||
2351 | /** | |
2352 | * ftrace_rec_iter_start, start up iterating over traced functions | |
2353 | * | |
2354 | * Returns an iterator handle that is used to iterate over all | |
2355 | * the records that represent address locations where functions | |
2356 | * are traced. | |
2357 | * | |
2358 | * May return NULL if no records are available. | |
2359 | */ | |
2360 | struct ftrace_rec_iter *ftrace_rec_iter_start(void) | |
2361 | { | |
2362 | /* | |
2363 | * We only use a single iterator. | |
2364 | * Protected by the ftrace_lock mutex. | |
2365 | */ | |
2366 | static struct ftrace_rec_iter ftrace_rec_iter; | |
2367 | struct ftrace_rec_iter *iter = &ftrace_rec_iter; | |
2368 | ||
2369 | iter->pg = ftrace_pages_start; | |
2370 | iter->index = 0; | |
2371 | ||
2372 | /* Could have empty pages */ | |
2373 | while (iter->pg && !iter->pg->index) | |
2374 | iter->pg = iter->pg->next; | |
2375 | ||
2376 | if (!iter->pg) | |
2377 | return NULL; | |
2378 | ||
2379 | return iter; | |
2380 | } | |
2381 | ||
2382 | /** | |
2383 | * ftrace_rec_iter_next, get the next record to process. | |
2384 | * @iter: The handle to the iterator. | |
2385 | * | |
2386 | * Returns the next iterator after the given iterator @iter. | |
2387 | */ | |
2388 | struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) | |
2389 | { | |
2390 | iter->index++; | |
2391 | ||
2392 | if (iter->index >= iter->pg->index) { | |
2393 | iter->pg = iter->pg->next; | |
2394 | iter->index = 0; | |
2395 | ||
2396 | /* Could have empty pages */ | |
2397 | while (iter->pg && !iter->pg->index) | |
2398 | iter->pg = iter->pg->next; | |
2399 | } | |
2400 | ||
2401 | if (!iter->pg) | |
2402 | return NULL; | |
2403 | ||
2404 | return iter; | |
2405 | } | |
2406 | ||
2407 | /** | |
2408 | * ftrace_rec_iter_record, get the record at the iterator location | |
2409 | * @iter: The current iterator location | |
2410 | * | |
2411 | * Returns the record that the current @iter is at. | |
2412 | */ | |
2413 | struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) | |
2414 | { | |
2415 | return &iter->pg->records[iter->index]; | |
2416 | } | |
2417 | ||
492a7ea5 | 2418 | static int |
31e88909 | 2419 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 | 2420 | { |
593eb8a2 | 2421 | int ret; |
3c1720f0 | 2422 | |
45a4a237 SR |
2423 | if (unlikely(ftrace_disabled)) |
2424 | return 0; | |
2425 | ||
25aac9dc | 2426 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 2427 | if (ret) { |
4fd3279b | 2428 | ftrace_bug(ret, rec); |
492a7ea5 | 2429 | return 0; |
37ad5084 | 2430 | } |
492a7ea5 | 2431 | return 1; |
3c1720f0 SR |
2432 | } |
2433 | ||
000ab691 SR |
2434 | /* |
2435 | * archs can override this function if they must do something | |
2436 | * before the modifying code is performed. | |
2437 | */ | |
2438 | int __weak ftrace_arch_code_modify_prepare(void) | |
2439 | { | |
2440 | return 0; | |
2441 | } | |
2442 | ||
2443 | /* | |
2444 | * archs can override this function if they must do something | |
2445 | * after the modifying code is performed. | |
2446 | */ | |
2447 | int __weak ftrace_arch_code_modify_post_process(void) | |
2448 | { | |
2449 | return 0; | |
2450 | } | |
2451 | ||
8ed3e2cf | 2452 | void ftrace_modify_all_code(int command) |
3d083395 | 2453 | { |
59338f75 | 2454 | int update = command & FTRACE_UPDATE_TRACE_FUNC; |
cd21067f | 2455 | int err = 0; |
59338f75 SRRH |
2456 | |
2457 | /* | |
2458 | * If the ftrace_caller calls a ftrace_ops func directly, | |
2459 | * we need to make sure that it only traces functions it | |
2460 | * expects to trace. When doing the switch of functions, | |
2461 | * we need to update to the ftrace_ops_list_func first | |
2462 | * before the transition between old and new calls are set, | |
2463 | * as the ftrace_ops_list_func will check the ops hashes | |
2464 | * to make sure the ops are having the right functions | |
2465 | * traced. | |
2466 | */ | |
cd21067f PM |
2467 | if (update) { |
2468 | err = ftrace_update_ftrace_func(ftrace_ops_list_func); | |
2469 | if (FTRACE_WARN_ON(err)) | |
2470 | return; | |
2471 | } | |
59338f75 | 2472 | |
8ed3e2cf | 2473 | if (command & FTRACE_UPDATE_CALLS) |
d61f82d0 | 2474 | ftrace_replace_code(1); |
8ed3e2cf | 2475 | else if (command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
2476 | ftrace_replace_code(0); |
2477 | ||
405e1d83 SRRH |
2478 | if (update && ftrace_trace_function != ftrace_ops_list_func) { |
2479 | function_trace_op = set_function_trace_op; | |
2480 | smp_wmb(); | |
2481 | /* If irqs are disabled, we are in stop machine */ | |
2482 | if (!irqs_disabled()) | |
2483 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
cd21067f PM |
2484 | err = ftrace_update_ftrace_func(ftrace_trace_function); |
2485 | if (FTRACE_WARN_ON(err)) | |
2486 | return; | |
405e1d83 | 2487 | } |
d61f82d0 | 2488 | |
8ed3e2cf | 2489 | if (command & FTRACE_START_FUNC_RET) |
cd21067f | 2490 | err = ftrace_enable_ftrace_graph_caller(); |
8ed3e2cf | 2491 | else if (command & FTRACE_STOP_FUNC_RET) |
cd21067f PM |
2492 | err = ftrace_disable_ftrace_graph_caller(); |
2493 | FTRACE_WARN_ON(err); | |
8ed3e2cf SR |
2494 | } |
2495 | ||
2496 | static int __ftrace_modify_code(void *data) | |
2497 | { | |
2498 | int *command = data; | |
2499 | ||
2500 | ftrace_modify_all_code(*command); | |
5a45cfe1 | 2501 | |
d61f82d0 | 2502 | return 0; |
3d083395 SR |
2503 | } |
2504 | ||
c88fd863 SR |
2505 | /** |
2506 | * ftrace_run_stop_machine, go back to the stop machine method | |
2507 | * @command: The command to tell ftrace what to do | |
2508 | * | |
2509 | * If an arch needs to fall back to the stop machine method, the | |
2510 | * it can call this function. | |
2511 | */ | |
2512 | void ftrace_run_stop_machine(int command) | |
2513 | { | |
2514 | stop_machine(__ftrace_modify_code, &command, NULL); | |
2515 | } | |
2516 | ||
2517 | /** | |
2518 | * arch_ftrace_update_code, modify the code to trace or not trace | |
2519 | * @command: The command that needs to be done | |
2520 | * | |
2521 | * Archs can override this function if it does not need to | |
2522 | * run stop_machine() to modify code. | |
2523 | */ | |
2524 | void __weak arch_ftrace_update_code(int command) | |
2525 | { | |
2526 | ftrace_run_stop_machine(command); | |
2527 | } | |
2528 | ||
e309b41d | 2529 | static void ftrace_run_update_code(int command) |
3d083395 | 2530 | { |
000ab691 SR |
2531 | int ret; |
2532 | ||
2533 | ret = ftrace_arch_code_modify_prepare(); | |
2534 | FTRACE_WARN_ON(ret); | |
2535 | if (ret) | |
2536 | return; | |
2537 | ||
c88fd863 SR |
2538 | /* |
2539 | * By default we use stop_machine() to modify the code. | |
2540 | * But archs can do what ever they want as long as it | |
2541 | * is safe. The stop_machine() is the safest, but also | |
2542 | * produces the most overhead. | |
2543 | */ | |
2544 | arch_ftrace_update_code(command); | |
2545 | ||
000ab691 SR |
2546 | ret = ftrace_arch_code_modify_post_process(); |
2547 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
2548 | } |
2549 | ||
8252ecf3 | 2550 | static void ftrace_run_modify_code(struct ftrace_ops *ops, int command, |
7485058e | 2551 | struct ftrace_ops_hash *old_hash) |
e1effa01 SRRH |
2552 | { |
2553 | ops->flags |= FTRACE_OPS_FL_MODIFYING; | |
7485058e SRRH |
2554 | ops->old_hash.filter_hash = old_hash->filter_hash; |
2555 | ops->old_hash.notrace_hash = old_hash->notrace_hash; | |
e1effa01 | 2556 | ftrace_run_update_code(command); |
8252ecf3 | 2557 | ops->old_hash.filter_hash = NULL; |
7485058e | 2558 | ops->old_hash.notrace_hash = NULL; |
e1effa01 SRRH |
2559 | ops->flags &= ~FTRACE_OPS_FL_MODIFYING; |
2560 | } | |
2561 | ||
d61f82d0 | 2562 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 2563 | static int ftrace_start_up; |
df4fc315 | 2564 | |
12cce594 SRRH |
2565 | void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops) |
2566 | { | |
2567 | } | |
2568 | ||
db0fbadc JS |
2569 | static void control_ops_free(struct ftrace_ops *ops) |
2570 | { | |
2571 | free_percpu(ops->disabled); | |
2572 | } | |
2573 | ||
df4fc315 SR |
2574 | static void ftrace_startup_enable(int command) |
2575 | { | |
2576 | if (saved_ftrace_func != ftrace_trace_function) { | |
2577 | saved_ftrace_func = ftrace_trace_function; | |
2578 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2579 | } | |
2580 | ||
2581 | if (!command || !ftrace_enabled) | |
2582 | return; | |
2583 | ||
2584 | ftrace_run_update_code(command); | |
2585 | } | |
d61f82d0 | 2586 | |
e1effa01 SRRH |
2587 | static void ftrace_startup_all(int command) |
2588 | { | |
2589 | update_all_ops = true; | |
2590 | ftrace_startup_enable(command); | |
2591 | update_all_ops = false; | |
2592 | } | |
2593 | ||
a1cd6173 | 2594 | static int ftrace_startup(struct ftrace_ops *ops, int command) |
3d083395 | 2595 | { |
8a56d776 | 2596 | int ret; |
b848914c | 2597 | |
4eebcc81 | 2598 | if (unlikely(ftrace_disabled)) |
a1cd6173 | 2599 | return -ENODEV; |
4eebcc81 | 2600 | |
8a56d776 SRRH |
2601 | ret = __register_ftrace_function(ops); |
2602 | if (ret) | |
2603 | return ret; | |
2604 | ||
60a7ecf4 | 2605 | ftrace_start_up++; |
30fb6aa7 | 2606 | command |= FTRACE_UPDATE_CALLS; |
d61f82d0 | 2607 | |
e1effa01 SRRH |
2608 | /* |
2609 | * Note that ftrace probes uses this to start up | |
2610 | * and modify functions it will probe. But we still | |
2611 | * set the ADDING flag for modification, as probes | |
2612 | * do not have trampolines. If they add them in the | |
2613 | * future, then the probes will need to distinguish | |
2614 | * between adding and updating probes. | |
2615 | */ | |
2616 | ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING; | |
66209a5b | 2617 | |
f8b8be8a MH |
2618 | ret = ftrace_hash_ipmodify_enable(ops); |
2619 | if (ret < 0) { | |
2620 | /* Rollback registration process */ | |
2621 | __unregister_ftrace_function(ops); | |
2622 | ftrace_start_up--; | |
2623 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; | |
2624 | return ret; | |
2625 | } | |
2626 | ||
66209a5b | 2627 | ftrace_hash_rec_enable(ops, 1); |
ed926f9b | 2628 | |
df4fc315 | 2629 | ftrace_startup_enable(command); |
a1cd6173 | 2630 | |
e1effa01 SRRH |
2631 | ops->flags &= ~FTRACE_OPS_FL_ADDING; |
2632 | ||
a1cd6173 | 2633 | return 0; |
3d083395 SR |
2634 | } |
2635 | ||
8a56d776 | 2636 | static int ftrace_shutdown(struct ftrace_ops *ops, int command) |
3d083395 | 2637 | { |
8a56d776 | 2638 | int ret; |
b848914c | 2639 | |
4eebcc81 | 2640 | if (unlikely(ftrace_disabled)) |
8a56d776 SRRH |
2641 | return -ENODEV; |
2642 | ||
2643 | ret = __unregister_ftrace_function(ops); | |
2644 | if (ret) | |
2645 | return ret; | |
4eebcc81 | 2646 | |
60a7ecf4 | 2647 | ftrace_start_up--; |
9ea1a153 FW |
2648 | /* |
2649 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
2650 | * critical but the ftrace_call callers may be never nopped again after | |
2651 | * further ftrace uses. | |
2652 | */ | |
2653 | WARN_ON_ONCE(ftrace_start_up < 0); | |
2654 | ||
f8b8be8a MH |
2655 | /* Disabling ipmodify never fails */ |
2656 | ftrace_hash_ipmodify_disable(ops); | |
66209a5b | 2657 | ftrace_hash_rec_disable(ops, 1); |
ed926f9b | 2658 | |
a737e6dd | 2659 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
b848914c | 2660 | |
30fb6aa7 | 2661 | command |= FTRACE_UPDATE_CALLS; |
3d083395 | 2662 | |
d61f82d0 SR |
2663 | if (saved_ftrace_func != ftrace_trace_function) { |
2664 | saved_ftrace_func = ftrace_trace_function; | |
2665 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2666 | } | |
3d083395 | 2667 | |
a4c35ed2 SRRH |
2668 | if (!command || !ftrace_enabled) { |
2669 | /* | |
2670 | * If these are control ops, they still need their | |
2671 | * per_cpu field freed. Since, function tracing is | |
2672 | * not currently active, we can just free them | |
2673 | * without synchronizing all CPUs. | |
2674 | */ | |
2675 | if (ops->flags & FTRACE_OPS_FL_CONTROL) | |
2676 | control_ops_free(ops); | |
8a56d776 | 2677 | return 0; |
a4c35ed2 | 2678 | } |
d61f82d0 | 2679 | |
79922b80 SRRH |
2680 | /* |
2681 | * If the ops uses a trampoline, then it needs to be | |
2682 | * tested first on update. | |
2683 | */ | |
e1effa01 | 2684 | ops->flags |= FTRACE_OPS_FL_REMOVING; |
79922b80 SRRH |
2685 | removed_ops = ops; |
2686 | ||
fef5aeee SRRH |
2687 | /* The trampoline logic checks the old hashes */ |
2688 | ops->old_hash.filter_hash = ops->func_hash->filter_hash; | |
2689 | ops->old_hash.notrace_hash = ops->func_hash->notrace_hash; | |
2690 | ||
d61f82d0 | 2691 | ftrace_run_update_code(command); |
a4c35ed2 | 2692 | |
84bde62c SRRH |
2693 | /* |
2694 | * If there's no more ops registered with ftrace, run a | |
2695 | * sanity check to make sure all rec flags are cleared. | |
2696 | */ | |
2697 | if (ftrace_ops_list == &ftrace_list_end) { | |
2698 | struct ftrace_page *pg; | |
2699 | struct dyn_ftrace *rec; | |
2700 | ||
2701 | do_for_each_ftrace_rec(pg, rec) { | |
2702 | if (FTRACE_WARN_ON_ONCE(rec->flags)) | |
2703 | pr_warn(" %pS flags:%lx\n", | |
2704 | (void *)rec->ip, rec->flags); | |
2705 | } while_for_each_ftrace_rec(); | |
2706 | } | |
2707 | ||
fef5aeee SRRH |
2708 | ops->old_hash.filter_hash = NULL; |
2709 | ops->old_hash.notrace_hash = NULL; | |
2710 | ||
2711 | removed_ops = NULL; | |
e1effa01 | 2712 | ops->flags &= ~FTRACE_OPS_FL_REMOVING; |
79922b80 | 2713 | |
a4c35ed2 SRRH |
2714 | /* |
2715 | * Dynamic ops may be freed, we must make sure that all | |
2716 | * callers are done before leaving this function. | |
2717 | * The same goes for freeing the per_cpu data of the control | |
2718 | * ops. | |
2719 | * | |
2720 | * Again, normal synchronize_sched() is not good enough. | |
2721 | * We need to do a hard force of sched synchronization. | |
2722 | * This is because we use preempt_disable() to do RCU, but | |
2723 | * the function tracers can be called where RCU is not watching | |
2724 | * (like before user_exit()). We can not rely on the RCU | |
2725 | * infrastructure to do the synchronization, thus we must do it | |
2726 | * ourselves. | |
2727 | */ | |
2728 | if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_CONTROL)) { | |
2729 | schedule_on_each_cpu(ftrace_sync); | |
2730 | ||
12cce594 SRRH |
2731 | arch_ftrace_trampoline_free(ops); |
2732 | ||
a4c35ed2 SRRH |
2733 | if (ops->flags & FTRACE_OPS_FL_CONTROL) |
2734 | control_ops_free(ops); | |
2735 | } | |
2736 | ||
8a56d776 | 2737 | return 0; |
3d083395 SR |
2738 | } |
2739 | ||
e309b41d | 2740 | static void ftrace_startup_sysctl(void) |
b0fc494f | 2741 | { |
1619dc3f PA |
2742 | int command; |
2743 | ||
4eebcc81 SR |
2744 | if (unlikely(ftrace_disabled)) |
2745 | return; | |
2746 | ||
d61f82d0 SR |
2747 | /* Force update next time */ |
2748 | saved_ftrace_func = NULL; | |
60a7ecf4 | 2749 | /* ftrace_start_up is true if we want ftrace running */ |
1619dc3f PA |
2750 | if (ftrace_start_up) { |
2751 | command = FTRACE_UPDATE_CALLS; | |
2752 | if (ftrace_graph_active) | |
2753 | command |= FTRACE_START_FUNC_RET; | |
524a3868 | 2754 | ftrace_startup_enable(command); |
1619dc3f | 2755 | } |
b0fc494f SR |
2756 | } |
2757 | ||
e309b41d | 2758 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 2759 | { |
1619dc3f PA |
2760 | int command; |
2761 | ||
4eebcc81 SR |
2762 | if (unlikely(ftrace_disabled)) |
2763 | return; | |
2764 | ||
60a7ecf4 | 2765 | /* ftrace_start_up is true if ftrace is running */ |
1619dc3f PA |
2766 | if (ftrace_start_up) { |
2767 | command = FTRACE_DISABLE_CALLS; | |
2768 | if (ftrace_graph_active) | |
2769 | command |= FTRACE_STOP_FUNC_RET; | |
2770 | ftrace_run_update_code(command); | |
2771 | } | |
b0fc494f SR |
2772 | } |
2773 | ||
3d083395 | 2774 | static cycle_t ftrace_update_time; |
3d083395 SR |
2775 | unsigned long ftrace_update_tot_cnt; |
2776 | ||
8c4f3c3f | 2777 | static inline int ops_traces_mod(struct ftrace_ops *ops) |
f7bc8b61 | 2778 | { |
8c4f3c3f SRRH |
2779 | /* |
2780 | * Filter_hash being empty will default to trace module. | |
2781 | * But notrace hash requires a test of individual module functions. | |
2782 | */ | |
33b7f99c SRRH |
2783 | return ftrace_hash_empty(ops->func_hash->filter_hash) && |
2784 | ftrace_hash_empty(ops->func_hash->notrace_hash); | |
8c4f3c3f SRRH |
2785 | } |
2786 | ||
2787 | /* | |
2788 | * Check if the current ops references the record. | |
2789 | * | |
2790 | * If the ops traces all functions, then it was already accounted for. | |
2791 | * If the ops does not trace the current record function, skip it. | |
2792 | * If the ops ignores the function via notrace filter, skip it. | |
2793 | */ | |
2794 | static inline bool | |
2795 | ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec) | |
2796 | { | |
2797 | /* If ops isn't enabled, ignore it */ | |
2798 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
2799 | return 0; | |
2800 | ||
2801 | /* If ops traces all mods, we already accounted for it */ | |
2802 | if (ops_traces_mod(ops)) | |
2803 | return 0; | |
2804 | ||
2805 | /* The function must be in the filter */ | |
33b7f99c SRRH |
2806 | if (!ftrace_hash_empty(ops->func_hash->filter_hash) && |
2807 | !ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip)) | |
8c4f3c3f | 2808 | return 0; |
f7bc8b61 | 2809 | |
8c4f3c3f | 2810 | /* If in notrace hash, we ignore it too */ |
33b7f99c | 2811 | if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip)) |
8c4f3c3f SRRH |
2812 | return 0; |
2813 | ||
2814 | return 1; | |
2815 | } | |
2816 | ||
2817 | static int referenced_filters(struct dyn_ftrace *rec) | |
2818 | { | |
2819 | struct ftrace_ops *ops; | |
2820 | int cnt = 0; | |
2821 | ||
2822 | for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) { | |
2823 | if (ops_references_rec(ops, rec)) | |
2824 | cnt++; | |
2825 | } | |
2826 | ||
2827 | return cnt; | |
f7bc8b61 SR |
2828 | } |
2829 | ||
1dc43cf0 | 2830 | static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs) |
3d083395 | 2831 | { |
85ae32ae | 2832 | struct ftrace_page *pg; |
e94142a6 | 2833 | struct dyn_ftrace *p; |
f22f9a89 | 2834 | cycle_t start, stop; |
1dc43cf0 | 2835 | unsigned long update_cnt = 0; |
f7bc8b61 | 2836 | unsigned long ref = 0; |
8c4f3c3f | 2837 | bool test = false; |
85ae32ae | 2838 | int i; |
f7bc8b61 SR |
2839 | |
2840 | /* | |
2841 | * When adding a module, we need to check if tracers are | |
2842 | * currently enabled and if they are set to trace all functions. | |
2843 | * If they are, we need to enable the module functions as well | |
2844 | * as update the reference counts for those function records. | |
2845 | */ | |
2846 | if (mod) { | |
2847 | struct ftrace_ops *ops; | |
2848 | ||
2849 | for (ops = ftrace_ops_list; | |
2850 | ops != &ftrace_list_end; ops = ops->next) { | |
8c4f3c3f SRRH |
2851 | if (ops->flags & FTRACE_OPS_FL_ENABLED) { |
2852 | if (ops_traces_mod(ops)) | |
2853 | ref++; | |
2854 | else | |
2855 | test = true; | |
2856 | } | |
f7bc8b61 SR |
2857 | } |
2858 | } | |
3d083395 | 2859 | |
750ed1a4 | 2860 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 | 2861 | |
1dc43cf0 | 2862 | for (pg = new_pgs; pg; pg = pg->next) { |
3d083395 | 2863 | |
85ae32ae | 2864 | for (i = 0; i < pg->index; i++) { |
8c4f3c3f SRRH |
2865 | int cnt = ref; |
2866 | ||
85ae32ae SR |
2867 | /* If something went wrong, bail without enabling anything */ |
2868 | if (unlikely(ftrace_disabled)) | |
2869 | return -1; | |
f22f9a89 | 2870 | |
85ae32ae | 2871 | p = &pg->records[i]; |
8c4f3c3f SRRH |
2872 | if (test) |
2873 | cnt += referenced_filters(p); | |
2874 | p->flags = cnt; | |
f22f9a89 | 2875 | |
85ae32ae SR |
2876 | /* |
2877 | * Do the initial record conversion from mcount jump | |
2878 | * to the NOP instructions. | |
2879 | */ | |
2880 | if (!ftrace_code_disable(mod, p)) | |
2881 | break; | |
5cb084bb | 2882 | |
1dc43cf0 | 2883 | update_cnt++; |
5cb084bb | 2884 | |
85ae32ae SR |
2885 | /* |
2886 | * If the tracing is enabled, go ahead and enable the record. | |
2887 | * | |
2888 | * The reason not to enable the record immediatelly is the | |
2889 | * inherent check of ftrace_make_nop/ftrace_make_call for | |
2890 | * correct previous instructions. Making first the NOP | |
2891 | * conversion puts the module to the correct state, thus | |
2892 | * passing the ftrace_make_call check. | |
2893 | */ | |
8c4f3c3f | 2894 | if (ftrace_start_up && cnt) { |
85ae32ae SR |
2895 | int failed = __ftrace_replace_code(p, 1); |
2896 | if (failed) | |
4fd3279b | 2897 | ftrace_bug(failed, p); |
85ae32ae | 2898 | } |
5cb084bb | 2899 | } |
3d083395 SR |
2900 | } |
2901 | ||
750ed1a4 | 2902 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 | 2903 | ftrace_update_time = stop - start; |
1dc43cf0 | 2904 | ftrace_update_tot_cnt += update_cnt; |
3d083395 | 2905 | |
16444a8a ACM |
2906 | return 0; |
2907 | } | |
2908 | ||
a7900875 | 2909 | static int ftrace_allocate_records(struct ftrace_page *pg, int count) |
3c1720f0 | 2910 | { |
a7900875 | 2911 | int order; |
3c1720f0 | 2912 | int cnt; |
3c1720f0 | 2913 | |
a7900875 SR |
2914 | if (WARN_ON(!count)) |
2915 | return -EINVAL; | |
2916 | ||
2917 | order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE)); | |
3c1720f0 SR |
2918 | |
2919 | /* | |
a7900875 SR |
2920 | * We want to fill as much as possible. No more than a page |
2921 | * may be empty. | |
3c1720f0 | 2922 | */ |
a7900875 SR |
2923 | while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE) |
2924 | order--; | |
3c1720f0 | 2925 | |
a7900875 SR |
2926 | again: |
2927 | pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order); | |
3c1720f0 | 2928 | |
a7900875 SR |
2929 | if (!pg->records) { |
2930 | /* if we can't allocate this size, try something smaller */ | |
2931 | if (!order) | |
2932 | return -ENOMEM; | |
2933 | order >>= 1; | |
2934 | goto again; | |
2935 | } | |
3c1720f0 | 2936 | |
a7900875 SR |
2937 | cnt = (PAGE_SIZE << order) / ENTRY_SIZE; |
2938 | pg->size = cnt; | |
3c1720f0 | 2939 | |
a7900875 SR |
2940 | if (cnt > count) |
2941 | cnt = count; | |
2942 | ||
2943 | return cnt; | |
2944 | } | |
2945 | ||
2946 | static struct ftrace_page * | |
2947 | ftrace_allocate_pages(unsigned long num_to_init) | |
2948 | { | |
2949 | struct ftrace_page *start_pg; | |
2950 | struct ftrace_page *pg; | |
2951 | int order; | |
2952 | int cnt; | |
2953 | ||
2954 | if (!num_to_init) | |
2955 | return 0; | |
2956 | ||
2957 | start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL); | |
2958 | if (!pg) | |
2959 | return NULL; | |
2960 | ||
2961 | /* | |
2962 | * Try to allocate as much as possible in one continues | |
2963 | * location that fills in all of the space. We want to | |
2964 | * waste as little space as possible. | |
2965 | */ | |
2966 | for (;;) { | |
2967 | cnt = ftrace_allocate_records(pg, num_to_init); | |
2968 | if (cnt < 0) | |
2969 | goto free_pages; | |
2970 | ||
2971 | num_to_init -= cnt; | |
2972 | if (!num_to_init) | |
3c1720f0 SR |
2973 | break; |
2974 | ||
a7900875 SR |
2975 | pg->next = kzalloc(sizeof(*pg), GFP_KERNEL); |
2976 | if (!pg->next) | |
2977 | goto free_pages; | |
2978 | ||
3c1720f0 SR |
2979 | pg = pg->next; |
2980 | } | |
2981 | ||
a7900875 SR |
2982 | return start_pg; |
2983 | ||
2984 | free_pages: | |
1f61be00 NK |
2985 | pg = start_pg; |
2986 | while (pg) { | |
a7900875 SR |
2987 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
2988 | free_pages((unsigned long)pg->records, order); | |
2989 | start_pg = pg->next; | |
2990 | kfree(pg); | |
2991 | pg = start_pg; | |
2992 | } | |
2993 | pr_info("ftrace: FAILED to allocate memory for functions\n"); | |
2994 | return NULL; | |
2995 | } | |
2996 | ||
5072c59f SR |
2997 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ |
2998 | ||
2999 | struct ftrace_iterator { | |
98c4fd04 | 3000 | loff_t pos; |
4aeb6967 SR |
3001 | loff_t func_pos; |
3002 | struct ftrace_page *pg; | |
3003 | struct dyn_ftrace *func; | |
3004 | struct ftrace_func_probe *probe; | |
3005 | struct trace_parser parser; | |
1cf41dd7 | 3006 | struct ftrace_hash *hash; |
33dc9b12 | 3007 | struct ftrace_ops *ops; |
4aeb6967 SR |
3008 | int hidx; |
3009 | int idx; | |
3010 | unsigned flags; | |
5072c59f SR |
3011 | }; |
3012 | ||
8fc0c701 | 3013 | static void * |
4aeb6967 | 3014 | t_hash_next(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
3015 | { |
3016 | struct ftrace_iterator *iter = m->private; | |
4aeb6967 | 3017 | struct hlist_node *hnd = NULL; |
8fc0c701 SR |
3018 | struct hlist_head *hhd; |
3019 | ||
8fc0c701 | 3020 | (*pos)++; |
98c4fd04 | 3021 | iter->pos = *pos; |
8fc0c701 | 3022 | |
4aeb6967 SR |
3023 | if (iter->probe) |
3024 | hnd = &iter->probe->node; | |
8fc0c701 SR |
3025 | retry: |
3026 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
3027 | return NULL; | |
3028 | ||
3029 | hhd = &ftrace_func_hash[iter->hidx]; | |
3030 | ||
3031 | if (hlist_empty(hhd)) { | |
3032 | iter->hidx++; | |
3033 | hnd = NULL; | |
3034 | goto retry; | |
3035 | } | |
3036 | ||
3037 | if (!hnd) | |
3038 | hnd = hhd->first; | |
3039 | else { | |
3040 | hnd = hnd->next; | |
3041 | if (!hnd) { | |
3042 | iter->hidx++; | |
3043 | goto retry; | |
3044 | } | |
3045 | } | |
3046 | ||
4aeb6967 SR |
3047 | if (WARN_ON_ONCE(!hnd)) |
3048 | return NULL; | |
3049 | ||
3050 | iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node); | |
3051 | ||
3052 | return iter; | |
8fc0c701 SR |
3053 | } |
3054 | ||
3055 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
3056 | { | |
3057 | struct ftrace_iterator *iter = m->private; | |
3058 | void *p = NULL; | |
d82d6244 LZ |
3059 | loff_t l; |
3060 | ||
69a3083c SR |
3061 | if (!(iter->flags & FTRACE_ITER_DO_HASH)) |
3062 | return NULL; | |
3063 | ||
2bccfffd SR |
3064 | if (iter->func_pos > *pos) |
3065 | return NULL; | |
8fc0c701 | 3066 | |
d82d6244 | 3067 | iter->hidx = 0; |
2bccfffd | 3068 | for (l = 0; l <= (*pos - iter->func_pos); ) { |
4aeb6967 | 3069 | p = t_hash_next(m, &l); |
d82d6244 LZ |
3070 | if (!p) |
3071 | break; | |
3072 | } | |
4aeb6967 SR |
3073 | if (!p) |
3074 | return NULL; | |
3075 | ||
98c4fd04 SR |
3076 | /* Only set this if we have an item */ |
3077 | iter->flags |= FTRACE_ITER_HASH; | |
3078 | ||
4aeb6967 | 3079 | return iter; |
8fc0c701 SR |
3080 | } |
3081 | ||
4aeb6967 SR |
3082 | static int |
3083 | t_hash_show(struct seq_file *m, struct ftrace_iterator *iter) | |
8fc0c701 | 3084 | { |
b6887d79 | 3085 | struct ftrace_func_probe *rec; |
8fc0c701 | 3086 | |
4aeb6967 SR |
3087 | rec = iter->probe; |
3088 | if (WARN_ON_ONCE(!rec)) | |
3089 | return -EIO; | |
8fc0c701 | 3090 | |
809dcf29 SR |
3091 | if (rec->ops->print) |
3092 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
3093 | ||
b375a11a | 3094 | seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func); |
8fc0c701 SR |
3095 | |
3096 | if (rec->data) | |
3097 | seq_printf(m, ":%p", rec->data); | |
3098 | seq_putc(m, '\n'); | |
3099 | ||
3100 | return 0; | |
3101 | } | |
3102 | ||
e309b41d | 3103 | static void * |
5072c59f SR |
3104 | t_next(struct seq_file *m, void *v, loff_t *pos) |
3105 | { | |
3106 | struct ftrace_iterator *iter = m->private; | |
fc13cb0c | 3107 | struct ftrace_ops *ops = iter->ops; |
5072c59f SR |
3108 | struct dyn_ftrace *rec = NULL; |
3109 | ||
45a4a237 SR |
3110 | if (unlikely(ftrace_disabled)) |
3111 | return NULL; | |
3112 | ||
8fc0c701 | 3113 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 3114 | return t_hash_next(m, pos); |
8fc0c701 | 3115 | |
5072c59f | 3116 | (*pos)++; |
1106b699 | 3117 | iter->pos = iter->func_pos = *pos; |
5072c59f | 3118 | |
0c75a3ed | 3119 | if (iter->flags & FTRACE_ITER_PRINTALL) |
57c072c7 | 3120 | return t_hash_start(m, pos); |
0c75a3ed | 3121 | |
5072c59f SR |
3122 | retry: |
3123 | if (iter->idx >= iter->pg->index) { | |
3124 | if (iter->pg->next) { | |
3125 | iter->pg = iter->pg->next; | |
3126 | iter->idx = 0; | |
3127 | goto retry; | |
3128 | } | |
3129 | } else { | |
3130 | rec = &iter->pg->records[iter->idx++]; | |
32082309 | 3131 | if (((iter->flags & FTRACE_ITER_FILTER) && |
33b7f99c | 3132 | !(ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))) || |
0183fb1c | 3133 | |
41c52c0d | 3134 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
33b7f99c | 3135 | !ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip)) || |
647bcd03 SR |
3136 | |
3137 | ((iter->flags & FTRACE_ITER_ENABLED) && | |
23ea9c4d | 3138 | !(rec->flags & FTRACE_FL_ENABLED))) { |
647bcd03 | 3139 | |
5072c59f SR |
3140 | rec = NULL; |
3141 | goto retry; | |
3142 | } | |
3143 | } | |
3144 | ||
4aeb6967 | 3145 | if (!rec) |
57c072c7 | 3146 | return t_hash_start(m, pos); |
4aeb6967 SR |
3147 | |
3148 | iter->func = rec; | |
3149 | ||
3150 | return iter; | |
5072c59f SR |
3151 | } |
3152 | ||
98c4fd04 SR |
3153 | static void reset_iter_read(struct ftrace_iterator *iter) |
3154 | { | |
3155 | iter->pos = 0; | |
3156 | iter->func_pos = 0; | |
70f77b3f | 3157 | iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_HASH); |
5072c59f SR |
3158 | } |
3159 | ||
3160 | static void *t_start(struct seq_file *m, loff_t *pos) | |
3161 | { | |
3162 | struct ftrace_iterator *iter = m->private; | |
fc13cb0c | 3163 | struct ftrace_ops *ops = iter->ops; |
5072c59f | 3164 | void *p = NULL; |
694ce0a5 | 3165 | loff_t l; |
5072c59f | 3166 | |
8fc0c701 | 3167 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
3168 | |
3169 | if (unlikely(ftrace_disabled)) | |
3170 | return NULL; | |
3171 | ||
98c4fd04 SR |
3172 | /* |
3173 | * If an lseek was done, then reset and start from beginning. | |
3174 | */ | |
3175 | if (*pos < iter->pos) | |
3176 | reset_iter_read(iter); | |
3177 | ||
0c75a3ed SR |
3178 | /* |
3179 | * For set_ftrace_filter reading, if we have the filter | |
3180 | * off, we can short cut and just print out that all | |
3181 | * functions are enabled. | |
3182 | */ | |
8c006cf7 | 3183 | if ((iter->flags & FTRACE_ITER_FILTER && |
33b7f99c | 3184 | ftrace_hash_empty(ops->func_hash->filter_hash)) || |
8c006cf7 | 3185 | (iter->flags & FTRACE_ITER_NOTRACE && |
33b7f99c | 3186 | ftrace_hash_empty(ops->func_hash->notrace_hash))) { |
0c75a3ed | 3187 | if (*pos > 0) |
8fc0c701 | 3188 | return t_hash_start(m, pos); |
0c75a3ed | 3189 | iter->flags |= FTRACE_ITER_PRINTALL; |
df091625 CW |
3190 | /* reset in case of seek/pread */ |
3191 | iter->flags &= ~FTRACE_ITER_HASH; | |
0c75a3ed SR |
3192 | return iter; |
3193 | } | |
3194 | ||
8fc0c701 SR |
3195 | if (iter->flags & FTRACE_ITER_HASH) |
3196 | return t_hash_start(m, pos); | |
3197 | ||
98c4fd04 SR |
3198 | /* |
3199 | * Unfortunately, we need to restart at ftrace_pages_start | |
3200 | * every time we let go of the ftrace_mutex. This is because | |
3201 | * those pointers can change without the lock. | |
3202 | */ | |
694ce0a5 LZ |
3203 | iter->pg = ftrace_pages_start; |
3204 | iter->idx = 0; | |
3205 | for (l = 0; l <= *pos; ) { | |
3206 | p = t_next(m, p, &l); | |
3207 | if (!p) | |
3208 | break; | |
50cdaf08 | 3209 | } |
5821e1b7 | 3210 | |
69a3083c SR |
3211 | if (!p) |
3212 | return t_hash_start(m, pos); | |
4aeb6967 SR |
3213 | |
3214 | return iter; | |
5072c59f SR |
3215 | } |
3216 | ||
3217 | static void t_stop(struct seq_file *m, void *p) | |
3218 | { | |
8fc0c701 | 3219 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
3220 | } |
3221 | ||
15d5b02c SRRH |
3222 | void * __weak |
3223 | arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec) | |
3224 | { | |
3225 | return NULL; | |
3226 | } | |
3227 | ||
3228 | static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops, | |
3229 | struct dyn_ftrace *rec) | |
3230 | { | |
3231 | void *ptr; | |
3232 | ||
3233 | ptr = arch_ftrace_trampoline_func(ops, rec); | |
3234 | if (ptr) | |
3235 | seq_printf(m, " ->%pS", ptr); | |
3236 | } | |
3237 | ||
5072c59f SR |
3238 | static int t_show(struct seq_file *m, void *v) |
3239 | { | |
0c75a3ed | 3240 | struct ftrace_iterator *iter = m->private; |
4aeb6967 | 3241 | struct dyn_ftrace *rec; |
5072c59f | 3242 | |
8fc0c701 | 3243 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 3244 | return t_hash_show(m, iter); |
8fc0c701 | 3245 | |
0c75a3ed | 3246 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
8c006cf7 | 3247 | if (iter->flags & FTRACE_ITER_NOTRACE) |
fa6f0cc7 | 3248 | seq_puts(m, "#### no functions disabled ####\n"); |
8c006cf7 | 3249 | else |
fa6f0cc7 | 3250 | seq_puts(m, "#### all functions enabled ####\n"); |
0c75a3ed SR |
3251 | return 0; |
3252 | } | |
3253 | ||
4aeb6967 SR |
3254 | rec = iter->func; |
3255 | ||
5072c59f SR |
3256 | if (!rec) |
3257 | return 0; | |
3258 | ||
647bcd03 | 3259 | seq_printf(m, "%ps", (void *)rec->ip); |
9674b2fa | 3260 | if (iter->flags & FTRACE_ITER_ENABLED) { |
15d5b02c SRRH |
3261 | struct ftrace_ops *ops = NULL; |
3262 | ||
f8b8be8a | 3263 | seq_printf(m, " (%ld)%s%s", |
0376bde1 | 3264 | ftrace_rec_count(rec), |
f8b8be8a MH |
3265 | rec->flags & FTRACE_FL_REGS ? " R" : " ", |
3266 | rec->flags & FTRACE_FL_IPMODIFY ? " I" : " "); | |
9674b2fa | 3267 | if (rec->flags & FTRACE_FL_TRAMP_EN) { |
5fecaa04 | 3268 | ops = ftrace_find_tramp_ops_any(rec); |
fef5aeee | 3269 | if (ops) |
9674b2fa SRRH |
3270 | seq_printf(m, "\ttramp: %pS", |
3271 | (void *)ops->trampoline); | |
3272 | else | |
fa6f0cc7 | 3273 | seq_puts(m, "\ttramp: ERROR!"); |
15d5b02c | 3274 | |
9674b2fa | 3275 | } |
15d5b02c | 3276 | add_trampoline_func(m, ops, rec); |
9674b2fa SRRH |
3277 | } |
3278 | ||
fa6f0cc7 | 3279 | seq_putc(m, '\n'); |
5072c59f SR |
3280 | |
3281 | return 0; | |
3282 | } | |
3283 | ||
88e9d34c | 3284 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
3285 | .start = t_start, |
3286 | .next = t_next, | |
3287 | .stop = t_stop, | |
3288 | .show = t_show, | |
3289 | }; | |
3290 | ||
e309b41d | 3291 | static int |
5072c59f SR |
3292 | ftrace_avail_open(struct inode *inode, struct file *file) |
3293 | { | |
3294 | struct ftrace_iterator *iter; | |
5072c59f | 3295 | |
4eebcc81 SR |
3296 | if (unlikely(ftrace_disabled)) |
3297 | return -ENODEV; | |
3298 | ||
50e18b94 JO |
3299 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
3300 | if (iter) { | |
3301 | iter->pg = ftrace_pages_start; | |
3302 | iter->ops = &global_ops; | |
4bf39a94 | 3303 | } |
5072c59f | 3304 | |
50e18b94 | 3305 | return iter ? 0 : -ENOMEM; |
5072c59f SR |
3306 | } |
3307 | ||
647bcd03 SR |
3308 | static int |
3309 | ftrace_enabled_open(struct inode *inode, struct file *file) | |
3310 | { | |
3311 | struct ftrace_iterator *iter; | |
647bcd03 | 3312 | |
50e18b94 JO |
3313 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
3314 | if (iter) { | |
3315 | iter->pg = ftrace_pages_start; | |
3316 | iter->flags = FTRACE_ITER_ENABLED; | |
3317 | iter->ops = &global_ops; | |
647bcd03 SR |
3318 | } |
3319 | ||
50e18b94 | 3320 | return iter ? 0 : -ENOMEM; |
647bcd03 SR |
3321 | } |
3322 | ||
fc13cb0c SR |
3323 | /** |
3324 | * ftrace_regex_open - initialize function tracer filter files | |
3325 | * @ops: The ftrace_ops that hold the hash filters | |
3326 | * @flag: The type of filter to process | |
3327 | * @inode: The inode, usually passed in to your open routine | |
3328 | * @file: The file, usually passed in to your open routine | |
3329 | * | |
3330 | * ftrace_regex_open() initializes the filter files for the | |
3331 | * @ops. Depending on @flag it may process the filter hash or | |
3332 | * the notrace hash of @ops. With this called from the open | |
3333 | * routine, you can use ftrace_filter_write() for the write | |
3334 | * routine if @flag has FTRACE_ITER_FILTER set, or | |
3335 | * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set. | |
098c879e | 3336 | * tracing_lseek() should be used as the lseek routine, and |
fc13cb0c SR |
3337 | * release must call ftrace_regex_release(). |
3338 | */ | |
3339 | int | |
f45948e8 | 3340 | ftrace_regex_open(struct ftrace_ops *ops, int flag, |
1cf41dd7 | 3341 | struct inode *inode, struct file *file) |
5072c59f SR |
3342 | { |
3343 | struct ftrace_iterator *iter; | |
f45948e8 | 3344 | struct ftrace_hash *hash; |
5072c59f SR |
3345 | int ret = 0; |
3346 | ||
f04f24fb MH |
3347 | ftrace_ops_init(ops); |
3348 | ||
4eebcc81 SR |
3349 | if (unlikely(ftrace_disabled)) |
3350 | return -ENODEV; | |
3351 | ||
5072c59f SR |
3352 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
3353 | if (!iter) | |
3354 | return -ENOMEM; | |
3355 | ||
689fd8b6 | 3356 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) { |
3357 | kfree(iter); | |
3358 | return -ENOMEM; | |
3359 | } | |
3360 | ||
3f2367ba MH |
3361 | iter->ops = ops; |
3362 | iter->flags = flag; | |
3363 | ||
33b7f99c | 3364 | mutex_lock(&ops->func_hash->regex_lock); |
3f2367ba | 3365 | |
f45948e8 | 3366 | if (flag & FTRACE_ITER_NOTRACE) |
33b7f99c | 3367 | hash = ops->func_hash->notrace_hash; |
f45948e8 | 3368 | else |
33b7f99c | 3369 | hash = ops->func_hash->filter_hash; |
f45948e8 | 3370 | |
33dc9b12 | 3371 | if (file->f_mode & FMODE_WRITE) { |
ef2fbe16 NK |
3372 | const int size_bits = FTRACE_HASH_DEFAULT_BITS; |
3373 | ||
3374 | if (file->f_flags & O_TRUNC) | |
3375 | iter->hash = alloc_ftrace_hash(size_bits); | |
3376 | else | |
3377 | iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash); | |
3378 | ||
33dc9b12 SR |
3379 | if (!iter->hash) { |
3380 | trace_parser_put(&iter->parser); | |
3381 | kfree(iter); | |
3f2367ba MH |
3382 | ret = -ENOMEM; |
3383 | goto out_unlock; | |
33dc9b12 SR |
3384 | } |
3385 | } | |
1cf41dd7 | 3386 | |
5072c59f SR |
3387 | if (file->f_mode & FMODE_READ) { |
3388 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
3389 | |
3390 | ret = seq_open(file, &show_ftrace_seq_ops); | |
3391 | if (!ret) { | |
3392 | struct seq_file *m = file->private_data; | |
3393 | m->private = iter; | |
79fe249c | 3394 | } else { |
33dc9b12 SR |
3395 | /* Failed */ |
3396 | free_ftrace_hash(iter->hash); | |
79fe249c | 3397 | trace_parser_put(&iter->parser); |
5072c59f | 3398 | kfree(iter); |
79fe249c | 3399 | } |
5072c59f SR |
3400 | } else |
3401 | file->private_data = iter; | |
3f2367ba MH |
3402 | |
3403 | out_unlock: | |
33b7f99c | 3404 | mutex_unlock(&ops->func_hash->regex_lock); |
5072c59f SR |
3405 | |
3406 | return ret; | |
3407 | } | |
3408 | ||
41c52c0d SR |
3409 | static int |
3410 | ftrace_filter_open(struct inode *inode, struct file *file) | |
3411 | { | |
e3b3e2e8 SRRH |
3412 | struct ftrace_ops *ops = inode->i_private; |
3413 | ||
3414 | return ftrace_regex_open(ops, | |
69a3083c SR |
3415 | FTRACE_ITER_FILTER | FTRACE_ITER_DO_HASH, |
3416 | inode, file); | |
41c52c0d SR |
3417 | } |
3418 | ||
3419 | static int | |
3420 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
3421 | { | |
e3b3e2e8 SRRH |
3422 | struct ftrace_ops *ops = inode->i_private; |
3423 | ||
3424 | return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE, | |
1cf41dd7 | 3425 | inode, file); |
41c52c0d SR |
3426 | } |
3427 | ||
64e7c440 | 3428 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 3429 | { |
9f4801e3 | 3430 | int matched = 0; |
751e9983 | 3431 | int slen; |
9f4801e3 | 3432 | |
9f4801e3 SR |
3433 | switch (type) { |
3434 | case MATCH_FULL: | |
3435 | if (strcmp(str, regex) == 0) | |
3436 | matched = 1; | |
3437 | break; | |
3438 | case MATCH_FRONT_ONLY: | |
3439 | if (strncmp(str, regex, len) == 0) | |
3440 | matched = 1; | |
3441 | break; | |
3442 | case MATCH_MIDDLE_ONLY: | |
3443 | if (strstr(str, regex)) | |
3444 | matched = 1; | |
3445 | break; | |
3446 | case MATCH_END_ONLY: | |
751e9983 LZ |
3447 | slen = strlen(str); |
3448 | if (slen >= len && memcmp(str + slen - len, regex, len) == 0) | |
9f4801e3 SR |
3449 | matched = 1; |
3450 | break; | |
3451 | } | |
3452 | ||
3453 | return matched; | |
3454 | } | |
3455 | ||
b448c4e3 | 3456 | static int |
1cf41dd7 | 3457 | enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not) |
996e87be | 3458 | { |
b448c4e3 | 3459 | struct ftrace_func_entry *entry; |
b448c4e3 SR |
3460 | int ret = 0; |
3461 | ||
1cf41dd7 SR |
3462 | entry = ftrace_lookup_ip(hash, rec->ip); |
3463 | if (not) { | |
3464 | /* Do nothing if it doesn't exist */ | |
3465 | if (!entry) | |
3466 | return 0; | |
b448c4e3 | 3467 | |
33dc9b12 | 3468 | free_hash_entry(hash, entry); |
1cf41dd7 SR |
3469 | } else { |
3470 | /* Do nothing if it exists */ | |
3471 | if (entry) | |
3472 | return 0; | |
b448c4e3 | 3473 | |
1cf41dd7 | 3474 | ret = add_hash_entry(hash, rec->ip); |
b448c4e3 SR |
3475 | } |
3476 | return ret; | |
996e87be SR |
3477 | } |
3478 | ||
64e7c440 | 3479 | static int |
b9df92d2 SR |
3480 | ftrace_match_record(struct dyn_ftrace *rec, char *mod, |
3481 | char *regex, int len, int type) | |
64e7c440 SR |
3482 | { |
3483 | char str[KSYM_SYMBOL_LEN]; | |
b9df92d2 SR |
3484 | char *modname; |
3485 | ||
3486 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
3487 | ||
3488 | if (mod) { | |
3489 | /* module lookup requires matching the module */ | |
3490 | if (!modname || strcmp(modname, mod)) | |
3491 | return 0; | |
3492 | ||
3493 | /* blank search means to match all funcs in the mod */ | |
3494 | if (!len) | |
3495 | return 1; | |
3496 | } | |
64e7c440 | 3497 | |
64e7c440 SR |
3498 | return ftrace_match(str, regex, len, type); |
3499 | } | |
3500 | ||
1cf41dd7 SR |
3501 | static int |
3502 | match_records(struct ftrace_hash *hash, char *buff, | |
3503 | int len, char *mod, int not) | |
9f4801e3 | 3504 | { |
b9df92d2 | 3505 | unsigned search_len = 0; |
9f4801e3 SR |
3506 | struct ftrace_page *pg; |
3507 | struct dyn_ftrace *rec; | |
b9df92d2 SR |
3508 | int type = MATCH_FULL; |
3509 | char *search = buff; | |
311d16da | 3510 | int found = 0; |
b448c4e3 | 3511 | int ret; |
9f4801e3 | 3512 | |
b9df92d2 SR |
3513 | if (len) { |
3514 | type = filter_parse_regex(buff, len, &search, ¬); | |
3515 | search_len = strlen(search); | |
3516 | } | |
9f4801e3 | 3517 | |
52baf119 | 3518 | mutex_lock(&ftrace_lock); |
265c831c | 3519 | |
b9df92d2 SR |
3520 | if (unlikely(ftrace_disabled)) |
3521 | goto out_unlock; | |
9f4801e3 | 3522 | |
265c831c | 3523 | do_for_each_ftrace_rec(pg, rec) { |
b9df92d2 | 3524 | if (ftrace_match_record(rec, mod, search, search_len, type)) { |
1cf41dd7 | 3525 | ret = enter_record(hash, rec, not); |
b448c4e3 SR |
3526 | if (ret < 0) { |
3527 | found = ret; | |
3528 | goto out_unlock; | |
3529 | } | |
311d16da | 3530 | found = 1; |
265c831c SR |
3531 | } |
3532 | } while_for_each_ftrace_rec(); | |
b9df92d2 | 3533 | out_unlock: |
52baf119 | 3534 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
3535 | |
3536 | return found; | |
5072c59f SR |
3537 | } |
3538 | ||
64e7c440 | 3539 | static int |
1cf41dd7 | 3540 | ftrace_match_records(struct ftrace_hash *hash, char *buff, int len) |
64e7c440 | 3541 | { |
1cf41dd7 | 3542 | return match_records(hash, buff, len, NULL, 0); |
64e7c440 SR |
3543 | } |
3544 | ||
1cf41dd7 SR |
3545 | static int |
3546 | ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod) | |
64e7c440 | 3547 | { |
64e7c440 | 3548 | int not = 0; |
6a24a244 | 3549 | |
64e7c440 SR |
3550 | /* blank or '*' mean the same */ |
3551 | if (strcmp(buff, "*") == 0) | |
3552 | buff[0] = 0; | |
3553 | ||
3554 | /* handle the case of 'dont filter this module' */ | |
3555 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
3556 | buff[0] = 0; | |
3557 | not = 1; | |
3558 | } | |
3559 | ||
1cf41dd7 | 3560 | return match_records(hash, buff, strlen(buff), mod, not); |
64e7c440 SR |
3561 | } |
3562 | ||
f6180773 SR |
3563 | /* |
3564 | * We register the module command as a template to show others how | |
3565 | * to register the a command as well. | |
3566 | */ | |
3567 | ||
3568 | static int | |
43dd61c9 SR |
3569 | ftrace_mod_callback(struct ftrace_hash *hash, |
3570 | char *func, char *cmd, char *param, int enable) | |
f6180773 SR |
3571 | { |
3572 | char *mod; | |
b448c4e3 | 3573 | int ret = -EINVAL; |
f6180773 SR |
3574 | |
3575 | /* | |
3576 | * cmd == 'mod' because we only registered this func | |
3577 | * for the 'mod' ftrace_func_command. | |
3578 | * But if you register one func with multiple commands, | |
3579 | * you can tell which command was used by the cmd | |
3580 | * parameter. | |
3581 | */ | |
3582 | ||
3583 | /* we must have a module name */ | |
3584 | if (!param) | |
b448c4e3 | 3585 | return ret; |
f6180773 SR |
3586 | |
3587 | mod = strsep(¶m, ":"); | |
3588 | if (!strlen(mod)) | |
b448c4e3 | 3589 | return ret; |
f6180773 | 3590 | |
1cf41dd7 | 3591 | ret = ftrace_match_module_records(hash, func, mod); |
b448c4e3 SR |
3592 | if (!ret) |
3593 | ret = -EINVAL; | |
3594 | if (ret < 0) | |
3595 | return ret; | |
3596 | ||
3597 | return 0; | |
f6180773 SR |
3598 | } |
3599 | ||
3600 | static struct ftrace_func_command ftrace_mod_cmd = { | |
3601 | .name = "mod", | |
3602 | .func = ftrace_mod_callback, | |
3603 | }; | |
3604 | ||
3605 | static int __init ftrace_mod_cmd_init(void) | |
3606 | { | |
3607 | return register_ftrace_command(&ftrace_mod_cmd); | |
3608 | } | |
6f415672 | 3609 | core_initcall(ftrace_mod_cmd_init); |
f6180773 | 3610 | |
2f5f6ad9 | 3611 | static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 3612 | struct ftrace_ops *op, struct pt_regs *pt_regs) |
59df055f | 3613 | { |
b6887d79 | 3614 | struct ftrace_func_probe *entry; |
59df055f | 3615 | struct hlist_head *hhd; |
59df055f | 3616 | unsigned long key; |
59df055f SR |
3617 | |
3618 | key = hash_long(ip, FTRACE_HASH_BITS); | |
3619 | ||
3620 | hhd = &ftrace_func_hash[key]; | |
3621 | ||
3622 | if (hlist_empty(hhd)) | |
3623 | return; | |
3624 | ||
3625 | /* | |
3626 | * Disable preemption for these calls to prevent a RCU grace | |
3627 | * period. This syncs the hash iteration and freeing of items | |
3628 | * on the hash. rcu_read_lock is too dangerous here. | |
3629 | */ | |
5168ae50 | 3630 | preempt_disable_notrace(); |
1bb539ca | 3631 | hlist_for_each_entry_rcu_notrace(entry, hhd, node) { |
59df055f SR |
3632 | if (entry->ip == ip) |
3633 | entry->ops->func(ip, parent_ip, &entry->data); | |
3634 | } | |
5168ae50 | 3635 | preempt_enable_notrace(); |
59df055f SR |
3636 | } |
3637 | ||
b6887d79 | 3638 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 3639 | { |
fb9fb015 | 3640 | .func = function_trace_probe_call, |
f04f24fb | 3641 | .flags = FTRACE_OPS_FL_INITIALIZED, |
33b7f99c | 3642 | INIT_OPS_HASH(trace_probe_ops) |
59df055f SR |
3643 | }; |
3644 | ||
b6887d79 | 3645 | static int ftrace_probe_registered; |
59df055f | 3646 | |
7485058e | 3647 | static void __enable_ftrace_function_probe(struct ftrace_ops_hash *old_hash) |
59df055f | 3648 | { |
b848914c | 3649 | int ret; |
59df055f SR |
3650 | int i; |
3651 | ||
19dd603e SRRH |
3652 | if (ftrace_probe_registered) { |
3653 | /* still need to update the function call sites */ | |
3654 | if (ftrace_enabled) | |
8252ecf3 SRRH |
3655 | ftrace_run_modify_code(&trace_probe_ops, FTRACE_UPDATE_CALLS, |
3656 | old_hash); | |
59df055f | 3657 | return; |
19dd603e | 3658 | } |
59df055f SR |
3659 | |
3660 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
3661 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
3662 | if (hhd->first) | |
3663 | break; | |
3664 | } | |
3665 | /* Nothing registered? */ | |
3666 | if (i == FTRACE_FUNC_HASHSIZE) | |
3667 | return; | |
3668 | ||
8a56d776 | 3669 | ret = ftrace_startup(&trace_probe_ops, 0); |
b848914c | 3670 | |
b6887d79 | 3671 | ftrace_probe_registered = 1; |
59df055f SR |
3672 | } |
3673 | ||
b6887d79 | 3674 | static void __disable_ftrace_function_probe(void) |
59df055f SR |
3675 | { |
3676 | int i; | |
3677 | ||
b6887d79 | 3678 | if (!ftrace_probe_registered) |
59df055f SR |
3679 | return; |
3680 | ||
3681 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
3682 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
3683 | if (hhd->first) | |
3684 | return; | |
3685 | } | |
3686 | ||
3687 | /* no more funcs left */ | |
8a56d776 | 3688 | ftrace_shutdown(&trace_probe_ops, 0); |
b848914c | 3689 | |
b6887d79 | 3690 | ftrace_probe_registered = 0; |
59df055f SR |
3691 | } |
3692 | ||
3693 | ||
7818b388 | 3694 | static void ftrace_free_entry(struct ftrace_func_probe *entry) |
59df055f | 3695 | { |
59df055f | 3696 | if (entry->ops->free) |
e67efb93 | 3697 | entry->ops->free(entry->ops, entry->ip, &entry->data); |
59df055f SR |
3698 | kfree(entry); |
3699 | } | |
3700 | ||
59df055f | 3701 | int |
b6887d79 | 3702 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3703 | void *data) |
3704 | { | |
7485058e | 3705 | struct ftrace_ops_hash old_hash_ops; |
b6887d79 | 3706 | struct ftrace_func_probe *entry; |
33b7f99c | 3707 | struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash; |
3296fc4e | 3708 | struct ftrace_hash *old_hash = *orig_hash; |
e1df4cb6 | 3709 | struct ftrace_hash *hash; |
59df055f SR |
3710 | struct ftrace_page *pg; |
3711 | struct dyn_ftrace *rec; | |
59df055f | 3712 | int type, len, not; |
6a24a244 | 3713 | unsigned long key; |
59df055f SR |
3714 | int count = 0; |
3715 | char *search; | |
e1df4cb6 | 3716 | int ret; |
59df055f | 3717 | |
3f6fe06d | 3718 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
3719 | len = strlen(search); |
3720 | ||
b6887d79 | 3721 | /* we do not support '!' for function probes */ |
59df055f SR |
3722 | if (WARN_ON(not)) |
3723 | return -EINVAL; | |
3724 | ||
33b7f99c | 3725 | mutex_lock(&trace_probe_ops.func_hash->regex_lock); |
59df055f | 3726 | |
7485058e SRRH |
3727 | old_hash_ops.filter_hash = old_hash; |
3728 | /* Probes only have filters */ | |
3729 | old_hash_ops.notrace_hash = NULL; | |
3730 | ||
3296fc4e | 3731 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); |
e1df4cb6 SRRH |
3732 | if (!hash) { |
3733 | count = -ENOMEM; | |
5ae0bf59 | 3734 | goto out; |
e1df4cb6 SRRH |
3735 | } |
3736 | ||
3737 | if (unlikely(ftrace_disabled)) { | |
3738 | count = -ENODEV; | |
5ae0bf59 | 3739 | goto out; |
e1df4cb6 | 3740 | } |
59df055f | 3741 | |
5ae0bf59 SRRH |
3742 | mutex_lock(&ftrace_lock); |
3743 | ||
45a4a237 | 3744 | do_for_each_ftrace_rec(pg, rec) { |
59df055f | 3745 | |
b9df92d2 | 3746 | if (!ftrace_match_record(rec, NULL, search, len, type)) |
59df055f SR |
3747 | continue; |
3748 | ||
3749 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
3750 | if (!entry) { | |
b6887d79 | 3751 | /* If we did not process any, then return error */ |
59df055f SR |
3752 | if (!count) |
3753 | count = -ENOMEM; | |
3754 | goto out_unlock; | |
3755 | } | |
3756 | ||
3757 | count++; | |
3758 | ||
3759 | entry->data = data; | |
3760 | ||
3761 | /* | |
3762 | * The caller might want to do something special | |
3763 | * for each function we find. We call the callback | |
3764 | * to give the caller an opportunity to do so. | |
3765 | */ | |
e67efb93 SRRH |
3766 | if (ops->init) { |
3767 | if (ops->init(ops, rec->ip, &entry->data) < 0) { | |
59df055f SR |
3768 | /* caller does not like this func */ |
3769 | kfree(entry); | |
3770 | continue; | |
3771 | } | |
3772 | } | |
3773 | ||
e1df4cb6 SRRH |
3774 | ret = enter_record(hash, rec, 0); |
3775 | if (ret < 0) { | |
3776 | kfree(entry); | |
3777 | count = ret; | |
3778 | goto out_unlock; | |
3779 | } | |
3780 | ||
59df055f SR |
3781 | entry->ops = ops; |
3782 | entry->ip = rec->ip; | |
3783 | ||
3784 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
3785 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
3786 | ||
3787 | } while_for_each_ftrace_rec(); | |
e1df4cb6 SRRH |
3788 | |
3789 | ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash); | |
8252ecf3 | 3790 | |
7485058e | 3791 | __enable_ftrace_function_probe(&old_hash_ops); |
8252ecf3 | 3792 | |
3296fc4e SRRH |
3793 | if (!ret) |
3794 | free_ftrace_hash_rcu(old_hash); | |
3795 | else | |
e1df4cb6 SRRH |
3796 | count = ret; |
3797 | ||
59df055f | 3798 | out_unlock: |
5ae0bf59 SRRH |
3799 | mutex_unlock(&ftrace_lock); |
3800 | out: | |
33b7f99c | 3801 | mutex_unlock(&trace_probe_ops.func_hash->regex_lock); |
e1df4cb6 | 3802 | free_ftrace_hash(hash); |
59df055f SR |
3803 | |
3804 | return count; | |
3805 | } | |
3806 | ||
3807 | enum { | |
b6887d79 SR |
3808 | PROBE_TEST_FUNC = 1, |
3809 | PROBE_TEST_DATA = 2 | |
59df055f SR |
3810 | }; |
3811 | ||
3812 | static void | |
b6887d79 | 3813 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3814 | void *data, int flags) |
3815 | { | |
e1df4cb6 | 3816 | struct ftrace_func_entry *rec_entry; |
b6887d79 | 3817 | struct ftrace_func_probe *entry; |
7818b388 | 3818 | struct ftrace_func_probe *p; |
33b7f99c | 3819 | struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash; |
3296fc4e | 3820 | struct ftrace_hash *old_hash = *orig_hash; |
7818b388 | 3821 | struct list_head free_list; |
e1df4cb6 | 3822 | struct ftrace_hash *hash; |
b67bfe0d | 3823 | struct hlist_node *tmp; |
59df055f SR |
3824 | char str[KSYM_SYMBOL_LEN]; |
3825 | int type = MATCH_FULL; | |
3826 | int i, len = 0; | |
3827 | char *search; | |
3296fc4e | 3828 | int ret; |
59df055f | 3829 | |
b36461da | 3830 | if (glob && (strcmp(glob, "*") == 0 || !strlen(glob))) |
59df055f | 3831 | glob = NULL; |
b36461da | 3832 | else if (glob) { |
59df055f SR |
3833 | int not; |
3834 | ||
3f6fe06d | 3835 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
3836 | len = strlen(search); |
3837 | ||
b6887d79 | 3838 | /* we do not support '!' for function probes */ |
59df055f SR |
3839 | if (WARN_ON(not)) |
3840 | return; | |
3841 | } | |
3842 | ||
33b7f99c | 3843 | mutex_lock(&trace_probe_ops.func_hash->regex_lock); |
e1df4cb6 SRRH |
3844 | |
3845 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
3846 | if (!hash) | |
3847 | /* Hmm, should report this somehow */ | |
3848 | goto out_unlock; | |
3849 | ||
7818b388 SRRH |
3850 | INIT_LIST_HEAD(&free_list); |
3851 | ||
59df055f SR |
3852 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { |
3853 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
3854 | ||
b67bfe0d | 3855 | hlist_for_each_entry_safe(entry, tmp, hhd, node) { |
59df055f SR |
3856 | |
3857 | /* break up if statements for readability */ | |
b6887d79 | 3858 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
3859 | continue; |
3860 | ||
b6887d79 | 3861 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
3862 | continue; |
3863 | ||
3864 | /* do this last, since it is the most expensive */ | |
3865 | if (glob) { | |
3866 | kallsyms_lookup(entry->ip, NULL, NULL, | |
3867 | NULL, str); | |
3868 | if (!ftrace_match(str, glob, len, type)) | |
3869 | continue; | |
3870 | } | |
3871 | ||
e1df4cb6 SRRH |
3872 | rec_entry = ftrace_lookup_ip(hash, entry->ip); |
3873 | /* It is possible more than one entry had this ip */ | |
3874 | if (rec_entry) | |
3875 | free_hash_entry(hash, rec_entry); | |
3876 | ||
740466bc | 3877 | hlist_del_rcu(&entry->node); |
7818b388 | 3878 | list_add(&entry->free_list, &free_list); |
59df055f SR |
3879 | } |
3880 | } | |
3f2367ba | 3881 | mutex_lock(&ftrace_lock); |
b6887d79 | 3882 | __disable_ftrace_function_probe(); |
e1df4cb6 SRRH |
3883 | /* |
3884 | * Remove after the disable is called. Otherwise, if the last | |
3885 | * probe is removed, a null hash means *all enabled*. | |
3886 | */ | |
3296fc4e | 3887 | ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash); |
7818b388 | 3888 | synchronize_sched(); |
3296fc4e SRRH |
3889 | if (!ret) |
3890 | free_ftrace_hash_rcu(old_hash); | |
3891 | ||
7818b388 SRRH |
3892 | list_for_each_entry_safe(entry, p, &free_list, free_list) { |
3893 | list_del(&entry->free_list); | |
3894 | ftrace_free_entry(entry); | |
3895 | } | |
3f2367ba | 3896 | mutex_unlock(&ftrace_lock); |
7818b388 | 3897 | |
e1df4cb6 | 3898 | out_unlock: |
33b7f99c | 3899 | mutex_unlock(&trace_probe_ops.func_hash->regex_lock); |
e1df4cb6 | 3900 | free_ftrace_hash(hash); |
59df055f SR |
3901 | } |
3902 | ||
3903 | void | |
b6887d79 | 3904 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3905 | void *data) |
3906 | { | |
b6887d79 SR |
3907 | __unregister_ftrace_function_probe(glob, ops, data, |
3908 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
3909 | } |
3910 | ||
3911 | void | |
b6887d79 | 3912 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 3913 | { |
b6887d79 | 3914 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
3915 | } |
3916 | ||
b6887d79 | 3917 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 3918 | { |
b6887d79 | 3919 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
3920 | } |
3921 | ||
f6180773 SR |
3922 | static LIST_HEAD(ftrace_commands); |
3923 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
3924 | ||
38de93ab TZ |
3925 | /* |
3926 | * Currently we only register ftrace commands from __init, so mark this | |
3927 | * __init too. | |
3928 | */ | |
3929 | __init int register_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
3930 | { |
3931 | struct ftrace_func_command *p; | |
3932 | int ret = 0; | |
3933 | ||
3934 | mutex_lock(&ftrace_cmd_mutex); | |
3935 | list_for_each_entry(p, &ftrace_commands, list) { | |
3936 | if (strcmp(cmd->name, p->name) == 0) { | |
3937 | ret = -EBUSY; | |
3938 | goto out_unlock; | |
3939 | } | |
3940 | } | |
3941 | list_add(&cmd->list, &ftrace_commands); | |
3942 | out_unlock: | |
3943 | mutex_unlock(&ftrace_cmd_mutex); | |
3944 | ||
3945 | return ret; | |
3946 | } | |
3947 | ||
38de93ab TZ |
3948 | /* |
3949 | * Currently we only unregister ftrace commands from __init, so mark | |
3950 | * this __init too. | |
3951 | */ | |
3952 | __init int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
3953 | { |
3954 | struct ftrace_func_command *p, *n; | |
3955 | int ret = -ENODEV; | |
3956 | ||
3957 | mutex_lock(&ftrace_cmd_mutex); | |
3958 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
3959 | if (strcmp(cmd->name, p->name) == 0) { | |
3960 | ret = 0; | |
3961 | list_del_init(&p->list); | |
3962 | goto out_unlock; | |
3963 | } | |
3964 | } | |
3965 | out_unlock: | |
3966 | mutex_unlock(&ftrace_cmd_mutex); | |
3967 | ||
3968 | return ret; | |
3969 | } | |
3970 | ||
33dc9b12 SR |
3971 | static int ftrace_process_regex(struct ftrace_hash *hash, |
3972 | char *buff, int len, int enable) | |
64e7c440 | 3973 | { |
f6180773 | 3974 | char *func, *command, *next = buff; |
6a24a244 | 3975 | struct ftrace_func_command *p; |
0aff1c0c | 3976 | int ret = -EINVAL; |
64e7c440 SR |
3977 | |
3978 | func = strsep(&next, ":"); | |
3979 | ||
3980 | if (!next) { | |
1cf41dd7 | 3981 | ret = ftrace_match_records(hash, func, len); |
b448c4e3 SR |
3982 | if (!ret) |
3983 | ret = -EINVAL; | |
3984 | if (ret < 0) | |
3985 | return ret; | |
3986 | return 0; | |
64e7c440 SR |
3987 | } |
3988 | ||
f6180773 | 3989 | /* command found */ |
64e7c440 SR |
3990 | |
3991 | command = strsep(&next, ":"); | |
3992 | ||
f6180773 SR |
3993 | mutex_lock(&ftrace_cmd_mutex); |
3994 | list_for_each_entry(p, &ftrace_commands, list) { | |
3995 | if (strcmp(p->name, command) == 0) { | |
43dd61c9 | 3996 | ret = p->func(hash, func, command, next, enable); |
f6180773 SR |
3997 | goto out_unlock; |
3998 | } | |
64e7c440 | 3999 | } |
f6180773 SR |
4000 | out_unlock: |
4001 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 4002 | |
f6180773 | 4003 | return ret; |
64e7c440 SR |
4004 | } |
4005 | ||
e309b41d | 4006 | static ssize_t |
41c52c0d SR |
4007 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
4008 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
4009 | { |
4010 | struct ftrace_iterator *iter; | |
689fd8b6 | 4011 | struct trace_parser *parser; |
4012 | ssize_t ret, read; | |
5072c59f | 4013 | |
4ba7978e | 4014 | if (!cnt) |
5072c59f SR |
4015 | return 0; |
4016 | ||
5072c59f SR |
4017 | if (file->f_mode & FMODE_READ) { |
4018 | struct seq_file *m = file->private_data; | |
4019 | iter = m->private; | |
4020 | } else | |
4021 | iter = file->private_data; | |
4022 | ||
f04f24fb | 4023 | if (unlikely(ftrace_disabled)) |
3f2367ba MH |
4024 | return -ENODEV; |
4025 | ||
4026 | /* iter->hash is a local copy, so we don't need regex_lock */ | |
f04f24fb | 4027 | |
689fd8b6 | 4028 | parser = &iter->parser; |
4029 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 4030 | |
4ba7978e | 4031 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 4032 | !trace_parser_cont(parser)) { |
33dc9b12 | 4033 | ret = ftrace_process_regex(iter->hash, parser->buffer, |
689fd8b6 | 4034 | parser->idx, enable); |
313254a9 | 4035 | trace_parser_clear(parser); |
7c088b51 | 4036 | if (ret < 0) |
3f2367ba | 4037 | goto out; |
eda1e328 | 4038 | } |
5072c59f | 4039 | |
5072c59f | 4040 | ret = read; |
3f2367ba | 4041 | out: |
5072c59f SR |
4042 | return ret; |
4043 | } | |
4044 | ||
fc13cb0c | 4045 | ssize_t |
41c52c0d SR |
4046 | ftrace_filter_write(struct file *file, const char __user *ubuf, |
4047 | size_t cnt, loff_t *ppos) | |
4048 | { | |
4049 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
4050 | } | |
4051 | ||
fc13cb0c | 4052 | ssize_t |
41c52c0d SR |
4053 | ftrace_notrace_write(struct file *file, const char __user *ubuf, |
4054 | size_t cnt, loff_t *ppos) | |
4055 | { | |
4056 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
4057 | } | |
4058 | ||
33dc9b12 | 4059 | static int |
647664ea MH |
4060 | ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) |
4061 | { | |
4062 | struct ftrace_func_entry *entry; | |
4063 | ||
4064 | if (!ftrace_location(ip)) | |
4065 | return -EINVAL; | |
4066 | ||
4067 | if (remove) { | |
4068 | entry = ftrace_lookup_ip(hash, ip); | |
4069 | if (!entry) | |
4070 | return -ENOENT; | |
4071 | free_hash_entry(hash, entry); | |
4072 | return 0; | |
4073 | } | |
4074 | ||
4075 | return add_hash_entry(hash, ip); | |
4076 | } | |
4077 | ||
8252ecf3 | 4078 | static void ftrace_ops_update_code(struct ftrace_ops *ops, |
7485058e | 4079 | struct ftrace_ops_hash *old_hash) |
1c80c432 | 4080 | { |
8f86f837 SRRH |
4081 | struct ftrace_ops *op; |
4082 | ||
4083 | if (!ftrace_enabled) | |
4084 | return; | |
4085 | ||
4086 | if (ops->flags & FTRACE_OPS_FL_ENABLED) { | |
8252ecf3 | 4087 | ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash); |
8f86f837 SRRH |
4088 | return; |
4089 | } | |
4090 | ||
4091 | /* | |
4092 | * If this is the shared global_ops filter, then we need to | |
4093 | * check if there is another ops that shares it, is enabled. | |
4094 | * If so, we still need to run the modify code. | |
4095 | */ | |
4096 | if (ops->func_hash != &global_ops.local_hash) | |
4097 | return; | |
4098 | ||
4099 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
4100 | if (op->func_hash == &global_ops.local_hash && | |
4101 | op->flags & FTRACE_OPS_FL_ENABLED) { | |
4102 | ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash); | |
4103 | /* Only need to do this once */ | |
4104 | return; | |
4105 | } | |
4106 | } while_for_each_ftrace_op(op); | |
1c80c432 SRRH |
4107 | } |
4108 | ||
647664ea MH |
4109 | static int |
4110 | ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, | |
4111 | unsigned long ip, int remove, int reset, int enable) | |
41c52c0d | 4112 | { |
33dc9b12 | 4113 | struct ftrace_hash **orig_hash; |
7485058e | 4114 | struct ftrace_ops_hash old_hash_ops; |
3296fc4e | 4115 | struct ftrace_hash *old_hash; |
f45948e8 | 4116 | struct ftrace_hash *hash; |
33dc9b12 | 4117 | int ret; |
f45948e8 | 4118 | |
41c52c0d | 4119 | if (unlikely(ftrace_disabled)) |
33dc9b12 | 4120 | return -ENODEV; |
41c52c0d | 4121 | |
33b7f99c | 4122 | mutex_lock(&ops->func_hash->regex_lock); |
3f2367ba | 4123 | |
f45948e8 | 4124 | if (enable) |
33b7f99c | 4125 | orig_hash = &ops->func_hash->filter_hash; |
f45948e8 | 4126 | else |
33b7f99c | 4127 | orig_hash = &ops->func_hash->notrace_hash; |
33dc9b12 | 4128 | |
b972cc58 WN |
4129 | if (reset) |
4130 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); | |
4131 | else | |
4132 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
4133 | ||
3f2367ba MH |
4134 | if (!hash) { |
4135 | ret = -ENOMEM; | |
4136 | goto out_regex_unlock; | |
4137 | } | |
f45948e8 | 4138 | |
ac483c44 JO |
4139 | if (buf && !ftrace_match_records(hash, buf, len)) { |
4140 | ret = -EINVAL; | |
4141 | goto out_regex_unlock; | |
4142 | } | |
647664ea MH |
4143 | if (ip) { |
4144 | ret = ftrace_match_addr(hash, ip, remove); | |
4145 | if (ret < 0) | |
4146 | goto out_regex_unlock; | |
4147 | } | |
33dc9b12 SR |
4148 | |
4149 | mutex_lock(&ftrace_lock); | |
3296fc4e | 4150 | old_hash = *orig_hash; |
7485058e SRRH |
4151 | old_hash_ops.filter_hash = ops->func_hash->filter_hash; |
4152 | old_hash_ops.notrace_hash = ops->func_hash->notrace_hash; | |
41fb61c2 | 4153 | ret = ftrace_hash_move(ops, enable, orig_hash, hash); |
3296fc4e | 4154 | if (!ret) { |
7485058e | 4155 | ftrace_ops_update_code(ops, &old_hash_ops); |
3296fc4e SRRH |
4156 | free_ftrace_hash_rcu(old_hash); |
4157 | } | |
33dc9b12 SR |
4158 | mutex_unlock(&ftrace_lock); |
4159 | ||
ac483c44 | 4160 | out_regex_unlock: |
33b7f99c | 4161 | mutex_unlock(&ops->func_hash->regex_lock); |
33dc9b12 SR |
4162 | |
4163 | free_ftrace_hash(hash); | |
4164 | return ret; | |
41c52c0d SR |
4165 | } |
4166 | ||
647664ea MH |
4167 | static int |
4168 | ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove, | |
4169 | int reset, int enable) | |
4170 | { | |
4171 | return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable); | |
4172 | } | |
4173 | ||
4174 | /** | |
4175 | * ftrace_set_filter_ip - set a function to filter on in ftrace by address | |
4176 | * @ops - the ops to set the filter with | |
4177 | * @ip - the address to add to or remove from the filter. | |
4178 | * @remove - non zero to remove the ip from the filter | |
4179 | * @reset - non zero to reset all filters before applying this filter. | |
4180 | * | |
4181 | * Filters denote which functions should be enabled when tracing is enabled | |
4182 | * If @ip is NULL, it failes to update filter. | |
4183 | */ | |
4184 | int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, | |
4185 | int remove, int reset) | |
4186 | { | |
f04f24fb | 4187 | ftrace_ops_init(ops); |
647664ea MH |
4188 | return ftrace_set_addr(ops, ip, remove, reset, 1); |
4189 | } | |
4190 | EXPORT_SYMBOL_GPL(ftrace_set_filter_ip); | |
4191 | ||
4192 | static int | |
4193 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, | |
4194 | int reset, int enable) | |
4195 | { | |
4196 | return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable); | |
4197 | } | |
4198 | ||
77a2b37d SR |
4199 | /** |
4200 | * ftrace_set_filter - set a function to filter on in ftrace | |
936e074b SR |
4201 | * @ops - the ops to set the filter with |
4202 | * @buf - the string that holds the function filter text. | |
4203 | * @len - the length of the string. | |
4204 | * @reset - non zero to reset all filters before applying this filter. | |
4205 | * | |
4206 | * Filters denote which functions should be enabled when tracing is enabled. | |
4207 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
4208 | */ | |
ac483c44 | 4209 | int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
4210 | int len, int reset) |
4211 | { | |
f04f24fb | 4212 | ftrace_ops_init(ops); |
ac483c44 | 4213 | return ftrace_set_regex(ops, buf, len, reset, 1); |
936e074b SR |
4214 | } |
4215 | EXPORT_SYMBOL_GPL(ftrace_set_filter); | |
4216 | ||
4217 | /** | |
4218 | * ftrace_set_notrace - set a function to not trace in ftrace | |
4219 | * @ops - the ops to set the notrace filter with | |
4220 | * @buf - the string that holds the function notrace text. | |
4221 | * @len - the length of the string. | |
4222 | * @reset - non zero to reset all filters before applying this filter. | |
4223 | * | |
4224 | * Notrace Filters denote which functions should not be enabled when tracing | |
4225 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
4226 | * for tracing. | |
4227 | */ | |
ac483c44 | 4228 | int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
4229 | int len, int reset) |
4230 | { | |
f04f24fb | 4231 | ftrace_ops_init(ops); |
ac483c44 | 4232 | return ftrace_set_regex(ops, buf, len, reset, 0); |
936e074b SR |
4233 | } |
4234 | EXPORT_SYMBOL_GPL(ftrace_set_notrace); | |
4235 | /** | |
8d1b065d | 4236 | * ftrace_set_global_filter - set a function to filter on with global tracers |
77a2b37d SR |
4237 | * @buf - the string that holds the function filter text. |
4238 | * @len - the length of the string. | |
4239 | * @reset - non zero to reset all filters before applying this filter. | |
4240 | * | |
4241 | * Filters denote which functions should be enabled when tracing is enabled. | |
4242 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
4243 | */ | |
936e074b | 4244 | void ftrace_set_global_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 4245 | { |
f45948e8 | 4246 | ftrace_set_regex(&global_ops, buf, len, reset, 1); |
41c52c0d | 4247 | } |
936e074b | 4248 | EXPORT_SYMBOL_GPL(ftrace_set_global_filter); |
4eebcc81 | 4249 | |
41c52c0d | 4250 | /** |
8d1b065d | 4251 | * ftrace_set_global_notrace - set a function to not trace with global tracers |
41c52c0d SR |
4252 | * @buf - the string that holds the function notrace text. |
4253 | * @len - the length of the string. | |
4254 | * @reset - non zero to reset all filters before applying this filter. | |
4255 | * | |
4256 | * Notrace Filters denote which functions should not be enabled when tracing | |
4257 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
4258 | * for tracing. | |
4259 | */ | |
936e074b | 4260 | void ftrace_set_global_notrace(unsigned char *buf, int len, int reset) |
41c52c0d | 4261 | { |
f45948e8 | 4262 | ftrace_set_regex(&global_ops, buf, len, reset, 0); |
77a2b37d | 4263 | } |
936e074b | 4264 | EXPORT_SYMBOL_GPL(ftrace_set_global_notrace); |
77a2b37d | 4265 | |
2af15d6a SR |
4266 | /* |
4267 | * command line interface to allow users to set filters on boot up. | |
4268 | */ | |
4269 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
4270 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
4271 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
4272 | ||
f1ed7c74 SRRH |
4273 | /* Used by function selftest to not test if filter is set */ |
4274 | bool ftrace_filter_param __initdata; | |
4275 | ||
2af15d6a SR |
4276 | static int __init set_ftrace_notrace(char *str) |
4277 | { | |
f1ed7c74 | 4278 | ftrace_filter_param = true; |
75761cc1 | 4279 | strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
4280 | return 1; |
4281 | } | |
4282 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
4283 | ||
4284 | static int __init set_ftrace_filter(char *str) | |
4285 | { | |
f1ed7c74 | 4286 | ftrace_filter_param = true; |
75761cc1 | 4287 | strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
4288 | return 1; |
4289 | } | |
4290 | __setup("ftrace_filter=", set_ftrace_filter); | |
4291 | ||
369bc18f | 4292 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 4293 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
0d7d9a16 | 4294 | static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata; |
faf982a6 | 4295 | static int ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer); |
801c29fd | 4296 | |
f3bea491 SRRH |
4297 | static unsigned long save_global_trampoline; |
4298 | static unsigned long save_global_flags; | |
4299 | ||
369bc18f SA |
4300 | static int __init set_graph_function(char *str) |
4301 | { | |
06f43d66 | 4302 | strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
4303 | return 1; |
4304 | } | |
4305 | __setup("ftrace_graph_filter=", set_graph_function); | |
4306 | ||
0d7d9a16 NK |
4307 | static int __init set_graph_notrace_function(char *str) |
4308 | { | |
4309 | strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE); | |
4310 | return 1; | |
4311 | } | |
4312 | __setup("ftrace_graph_notrace=", set_graph_notrace_function); | |
4313 | ||
4314 | static void __init set_ftrace_early_graph(char *buf, int enable) | |
369bc18f SA |
4315 | { |
4316 | int ret; | |
4317 | char *func; | |
0d7d9a16 NK |
4318 | unsigned long *table = ftrace_graph_funcs; |
4319 | int *count = &ftrace_graph_count; | |
4320 | ||
4321 | if (!enable) { | |
4322 | table = ftrace_graph_notrace_funcs; | |
4323 | count = &ftrace_graph_notrace_count; | |
4324 | } | |
369bc18f SA |
4325 | |
4326 | while (buf) { | |
4327 | func = strsep(&buf, ","); | |
4328 | /* we allow only one expression at a time */ | |
0d7d9a16 | 4329 | ret = ftrace_set_func(table, count, FTRACE_GRAPH_MAX_FUNCS, func); |
369bc18f SA |
4330 | if (ret) |
4331 | printk(KERN_DEBUG "ftrace: function %s not " | |
4332 | "traceable\n", func); | |
4333 | } | |
4334 | } | |
4335 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
4336 | ||
2a85a37f SR |
4337 | void __init |
4338 | ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable) | |
2af15d6a SR |
4339 | { |
4340 | char *func; | |
4341 | ||
f04f24fb MH |
4342 | ftrace_ops_init(ops); |
4343 | ||
2af15d6a SR |
4344 | while (buf) { |
4345 | func = strsep(&buf, ","); | |
f45948e8 | 4346 | ftrace_set_regex(ops, func, strlen(func), 0, enable); |
2af15d6a SR |
4347 | } |
4348 | } | |
4349 | ||
4350 | static void __init set_ftrace_early_filters(void) | |
4351 | { | |
4352 | if (ftrace_filter_buf[0]) | |
2a85a37f | 4353 | ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1); |
2af15d6a | 4354 | if (ftrace_notrace_buf[0]) |
2a85a37f | 4355 | ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0); |
369bc18f SA |
4356 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
4357 | if (ftrace_graph_buf[0]) | |
0d7d9a16 NK |
4358 | set_ftrace_early_graph(ftrace_graph_buf, 1); |
4359 | if (ftrace_graph_notrace_buf[0]) | |
4360 | set_ftrace_early_graph(ftrace_graph_notrace_buf, 0); | |
369bc18f | 4361 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
2af15d6a SR |
4362 | } |
4363 | ||
fc13cb0c | 4364 | int ftrace_regex_release(struct inode *inode, struct file *file) |
5072c59f SR |
4365 | { |
4366 | struct seq_file *m = (struct seq_file *)file->private_data; | |
7485058e | 4367 | struct ftrace_ops_hash old_hash_ops; |
5072c59f | 4368 | struct ftrace_iterator *iter; |
33dc9b12 | 4369 | struct ftrace_hash **orig_hash; |
3296fc4e | 4370 | struct ftrace_hash *old_hash; |
689fd8b6 | 4371 | struct trace_parser *parser; |
ed926f9b | 4372 | int filter_hash; |
33dc9b12 | 4373 | int ret; |
5072c59f | 4374 | |
5072c59f SR |
4375 | if (file->f_mode & FMODE_READ) { |
4376 | iter = m->private; | |
5072c59f SR |
4377 | seq_release(inode, file); |
4378 | } else | |
4379 | iter = file->private_data; | |
4380 | ||
689fd8b6 | 4381 | parser = &iter->parser; |
4382 | if (trace_parser_loaded(parser)) { | |
4383 | parser->buffer[parser->idx] = 0; | |
1cf41dd7 | 4384 | ftrace_match_records(iter->hash, parser->buffer, parser->idx); |
5072c59f SR |
4385 | } |
4386 | ||
689fd8b6 | 4387 | trace_parser_put(parser); |
689fd8b6 | 4388 | |
33b7f99c | 4389 | mutex_lock(&iter->ops->func_hash->regex_lock); |
3f2367ba | 4390 | |
058e297d | 4391 | if (file->f_mode & FMODE_WRITE) { |
ed926f9b SR |
4392 | filter_hash = !!(iter->flags & FTRACE_ITER_FILTER); |
4393 | ||
4394 | if (filter_hash) | |
33b7f99c | 4395 | orig_hash = &iter->ops->func_hash->filter_hash; |
ed926f9b | 4396 | else |
33b7f99c | 4397 | orig_hash = &iter->ops->func_hash->notrace_hash; |
33dc9b12 | 4398 | |
058e297d | 4399 | mutex_lock(&ftrace_lock); |
3296fc4e | 4400 | old_hash = *orig_hash; |
7485058e SRRH |
4401 | old_hash_ops.filter_hash = iter->ops->func_hash->filter_hash; |
4402 | old_hash_ops.notrace_hash = iter->ops->func_hash->notrace_hash; | |
41fb61c2 SR |
4403 | ret = ftrace_hash_move(iter->ops, filter_hash, |
4404 | orig_hash, iter->hash); | |
3296fc4e | 4405 | if (!ret) { |
7485058e | 4406 | ftrace_ops_update_code(iter->ops, &old_hash_ops); |
3296fc4e SRRH |
4407 | free_ftrace_hash_rcu(old_hash); |
4408 | } | |
058e297d SR |
4409 | mutex_unlock(&ftrace_lock); |
4410 | } | |
3f2367ba | 4411 | |
33b7f99c | 4412 | mutex_unlock(&iter->ops->func_hash->regex_lock); |
33dc9b12 SR |
4413 | free_ftrace_hash(iter->hash); |
4414 | kfree(iter); | |
058e297d | 4415 | |
5072c59f SR |
4416 | return 0; |
4417 | } | |
4418 | ||
5e2336a0 | 4419 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
4420 | .open = ftrace_avail_open, |
4421 | .read = seq_read, | |
4422 | .llseek = seq_lseek, | |
3be04b47 | 4423 | .release = seq_release_private, |
5072c59f SR |
4424 | }; |
4425 | ||
647bcd03 SR |
4426 | static const struct file_operations ftrace_enabled_fops = { |
4427 | .open = ftrace_enabled_open, | |
4428 | .read = seq_read, | |
4429 | .llseek = seq_lseek, | |
4430 | .release = seq_release_private, | |
4431 | }; | |
4432 | ||
5e2336a0 | 4433 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 4434 | .open = ftrace_filter_open, |
850a80cf | 4435 | .read = seq_read, |
5072c59f | 4436 | .write = ftrace_filter_write, |
098c879e | 4437 | .llseek = tracing_lseek, |
1cf41dd7 | 4438 | .release = ftrace_regex_release, |
5072c59f SR |
4439 | }; |
4440 | ||
5e2336a0 | 4441 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 4442 | .open = ftrace_notrace_open, |
850a80cf | 4443 | .read = seq_read, |
41c52c0d | 4444 | .write = ftrace_notrace_write, |
098c879e | 4445 | .llseek = tracing_lseek, |
1cf41dd7 | 4446 | .release = ftrace_regex_release, |
41c52c0d SR |
4447 | }; |
4448 | ||
ea4e2bc4 SR |
4449 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
4450 | ||
4451 | static DEFINE_MUTEX(graph_lock); | |
4452 | ||
4453 | int ftrace_graph_count; | |
29ad23b0 | 4454 | int ftrace_graph_notrace_count; |
ea4e2bc4 | 4455 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
29ad23b0 | 4456 | unsigned long ftrace_graph_notrace_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
ea4e2bc4 | 4457 | |
faf982a6 NK |
4458 | struct ftrace_graph_data { |
4459 | unsigned long *table; | |
4460 | size_t size; | |
4461 | int *count; | |
4462 | const struct seq_operations *seq_ops; | |
4463 | }; | |
4464 | ||
ea4e2bc4 | 4465 | static void * |
85951842 | 4466 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 4467 | { |
faf982a6 NK |
4468 | struct ftrace_graph_data *fgd = m->private; |
4469 | ||
4470 | if (*pos >= *fgd->count) | |
ea4e2bc4 | 4471 | return NULL; |
faf982a6 | 4472 | return &fgd->table[*pos]; |
85951842 | 4473 | } |
ea4e2bc4 | 4474 | |
85951842 LZ |
4475 | static void * |
4476 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
4477 | { | |
4478 | (*pos)++; | |
4479 | return __g_next(m, pos); | |
ea4e2bc4 SR |
4480 | } |
4481 | ||
4482 | static void *g_start(struct seq_file *m, loff_t *pos) | |
4483 | { | |
faf982a6 NK |
4484 | struct ftrace_graph_data *fgd = m->private; |
4485 | ||
ea4e2bc4 SR |
4486 | mutex_lock(&graph_lock); |
4487 | ||
f9349a8f | 4488 | /* Nothing, tell g_show to print all functions are enabled */ |
faf982a6 | 4489 | if (!*fgd->count && !*pos) |
f9349a8f FW |
4490 | return (void *)1; |
4491 | ||
85951842 | 4492 | return __g_next(m, pos); |
ea4e2bc4 SR |
4493 | } |
4494 | ||
4495 | static void g_stop(struct seq_file *m, void *p) | |
4496 | { | |
4497 | mutex_unlock(&graph_lock); | |
4498 | } | |
4499 | ||
4500 | static int g_show(struct seq_file *m, void *v) | |
4501 | { | |
4502 | unsigned long *ptr = v; | |
ea4e2bc4 SR |
4503 | |
4504 | if (!ptr) | |
4505 | return 0; | |
4506 | ||
f9349a8f | 4507 | if (ptr == (unsigned long *)1) { |
280d1429 NK |
4508 | struct ftrace_graph_data *fgd = m->private; |
4509 | ||
4510 | if (fgd->table == ftrace_graph_funcs) | |
fa6f0cc7 | 4511 | seq_puts(m, "#### all functions enabled ####\n"); |
280d1429 | 4512 | else |
fa6f0cc7 | 4513 | seq_puts(m, "#### no functions disabled ####\n"); |
f9349a8f FW |
4514 | return 0; |
4515 | } | |
4516 | ||
b375a11a | 4517 | seq_printf(m, "%ps\n", (void *)*ptr); |
ea4e2bc4 SR |
4518 | |
4519 | return 0; | |
4520 | } | |
4521 | ||
88e9d34c | 4522 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
4523 | .start = g_start, |
4524 | .next = g_next, | |
4525 | .stop = g_stop, | |
4526 | .show = g_show, | |
4527 | }; | |
4528 | ||
4529 | static int | |
faf982a6 NK |
4530 | __ftrace_graph_open(struct inode *inode, struct file *file, |
4531 | struct ftrace_graph_data *fgd) | |
ea4e2bc4 SR |
4532 | { |
4533 | int ret = 0; | |
4534 | ||
ea4e2bc4 SR |
4535 | mutex_lock(&graph_lock); |
4536 | if ((file->f_mode & FMODE_WRITE) && | |
8650ae32 | 4537 | (file->f_flags & O_TRUNC)) { |
faf982a6 NK |
4538 | *fgd->count = 0; |
4539 | memset(fgd->table, 0, fgd->size * sizeof(*fgd->table)); | |
ea4e2bc4 | 4540 | } |
a4ec5e0c | 4541 | mutex_unlock(&graph_lock); |
ea4e2bc4 | 4542 | |
faf982a6 NK |
4543 | if (file->f_mode & FMODE_READ) { |
4544 | ret = seq_open(file, fgd->seq_ops); | |
4545 | if (!ret) { | |
4546 | struct seq_file *m = file->private_data; | |
4547 | m->private = fgd; | |
4548 | } | |
4549 | } else | |
4550 | file->private_data = fgd; | |
ea4e2bc4 SR |
4551 | |
4552 | return ret; | |
4553 | } | |
4554 | ||
faf982a6 NK |
4555 | static int |
4556 | ftrace_graph_open(struct inode *inode, struct file *file) | |
4557 | { | |
4558 | struct ftrace_graph_data *fgd; | |
4559 | ||
4560 | if (unlikely(ftrace_disabled)) | |
4561 | return -ENODEV; | |
4562 | ||
4563 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
4564 | if (fgd == NULL) | |
4565 | return -ENOMEM; | |
4566 | ||
4567 | fgd->table = ftrace_graph_funcs; | |
4568 | fgd->size = FTRACE_GRAPH_MAX_FUNCS; | |
4569 | fgd->count = &ftrace_graph_count; | |
4570 | fgd->seq_ops = &ftrace_graph_seq_ops; | |
4571 | ||
4572 | return __ftrace_graph_open(inode, file, fgd); | |
4573 | } | |
4574 | ||
29ad23b0 NK |
4575 | static int |
4576 | ftrace_graph_notrace_open(struct inode *inode, struct file *file) | |
4577 | { | |
4578 | struct ftrace_graph_data *fgd; | |
4579 | ||
4580 | if (unlikely(ftrace_disabled)) | |
4581 | return -ENODEV; | |
4582 | ||
4583 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
4584 | if (fgd == NULL) | |
4585 | return -ENOMEM; | |
4586 | ||
4587 | fgd->table = ftrace_graph_notrace_funcs; | |
4588 | fgd->size = FTRACE_GRAPH_MAX_FUNCS; | |
4589 | fgd->count = &ftrace_graph_notrace_count; | |
4590 | fgd->seq_ops = &ftrace_graph_seq_ops; | |
4591 | ||
4592 | return __ftrace_graph_open(inode, file, fgd); | |
4593 | } | |
4594 | ||
87827111 LZ |
4595 | static int |
4596 | ftrace_graph_release(struct inode *inode, struct file *file) | |
4597 | { | |
faf982a6 NK |
4598 | if (file->f_mode & FMODE_READ) { |
4599 | struct seq_file *m = file->private_data; | |
4600 | ||
4601 | kfree(m->private); | |
87827111 | 4602 | seq_release(inode, file); |
faf982a6 NK |
4603 | } else { |
4604 | kfree(file->private_data); | |
4605 | } | |
4606 | ||
87827111 LZ |
4607 | return 0; |
4608 | } | |
4609 | ||
ea4e2bc4 | 4610 | static int |
faf982a6 | 4611 | ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer) |
ea4e2bc4 | 4612 | { |
ea4e2bc4 SR |
4613 | struct dyn_ftrace *rec; |
4614 | struct ftrace_page *pg; | |
f9349a8f | 4615 | int search_len; |
c7c6b1fe | 4616 | int fail = 1; |
f9349a8f FW |
4617 | int type, not; |
4618 | char *search; | |
4619 | bool exists; | |
4620 | int i; | |
ea4e2bc4 | 4621 | |
f9349a8f | 4622 | /* decode regex */ |
3f6fe06d | 4623 | type = filter_parse_regex(buffer, strlen(buffer), &search, ¬); |
faf982a6 | 4624 | if (!not && *idx >= size) |
c7c6b1fe | 4625 | return -EBUSY; |
f9349a8f FW |
4626 | |
4627 | search_len = strlen(search); | |
4628 | ||
52baf119 | 4629 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
4630 | |
4631 | if (unlikely(ftrace_disabled)) { | |
4632 | mutex_unlock(&ftrace_lock); | |
4633 | return -ENODEV; | |
4634 | } | |
4635 | ||
265c831c SR |
4636 | do_for_each_ftrace_rec(pg, rec) { |
4637 | ||
b9df92d2 | 4638 | if (ftrace_match_record(rec, NULL, search, search_len, type)) { |
c7c6b1fe | 4639 | /* if it is in the array */ |
f9349a8f | 4640 | exists = false; |
c7c6b1fe | 4641 | for (i = 0; i < *idx; i++) { |
f9349a8f FW |
4642 | if (array[i] == rec->ip) { |
4643 | exists = true; | |
265c831c SR |
4644 | break; |
4645 | } | |
c7c6b1fe LZ |
4646 | } |
4647 | ||
4648 | if (!not) { | |
4649 | fail = 0; | |
4650 | if (!exists) { | |
4651 | array[(*idx)++] = rec->ip; | |
faf982a6 | 4652 | if (*idx >= size) |
c7c6b1fe LZ |
4653 | goto out; |
4654 | } | |
4655 | } else { | |
4656 | if (exists) { | |
4657 | array[i] = array[--(*idx)]; | |
4658 | array[*idx] = 0; | |
4659 | fail = 0; | |
4660 | } | |
4661 | } | |
ea4e2bc4 | 4662 | } |
265c831c | 4663 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 4664 | out: |
52baf119 | 4665 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 4666 | |
c7c6b1fe LZ |
4667 | if (fail) |
4668 | return -EINVAL; | |
4669 | ||
c7c6b1fe | 4670 | return 0; |
ea4e2bc4 SR |
4671 | } |
4672 | ||
4673 | static ssize_t | |
4674 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
4675 | size_t cnt, loff_t *ppos) | |
4676 | { | |
689fd8b6 | 4677 | struct trace_parser parser; |
6a10108b | 4678 | ssize_t read, ret = 0; |
faf982a6 | 4679 | struct ftrace_graph_data *fgd = file->private_data; |
ea4e2bc4 | 4680 | |
c7c6b1fe | 4681 | if (!cnt) |
ea4e2bc4 SR |
4682 | return 0; |
4683 | ||
6a10108b NK |
4684 | if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) |
4685 | return -ENOMEM; | |
ea4e2bc4 | 4686 | |
689fd8b6 | 4687 | read = trace_get_user(&parser, ubuf, cnt, ppos); |
ea4e2bc4 | 4688 | |
4ba7978e | 4689 | if (read >= 0 && trace_parser_loaded((&parser))) { |
689fd8b6 | 4690 | parser.buffer[parser.idx] = 0; |
4691 | ||
6a10108b NK |
4692 | mutex_lock(&graph_lock); |
4693 | ||
689fd8b6 | 4694 | /* we allow only one expression at a time */ |
faf982a6 NK |
4695 | ret = ftrace_set_func(fgd->table, fgd->count, fgd->size, |
4696 | parser.buffer); | |
6a10108b NK |
4697 | |
4698 | mutex_unlock(&graph_lock); | |
ea4e2bc4 | 4699 | } |
ea4e2bc4 | 4700 | |
6a10108b NK |
4701 | if (!ret) |
4702 | ret = read; | |
1eb90f13 | 4703 | |
689fd8b6 | 4704 | trace_parser_put(&parser); |
ea4e2bc4 SR |
4705 | |
4706 | return ret; | |
4707 | } | |
4708 | ||
4709 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
4710 | .open = ftrace_graph_open, |
4711 | .read = seq_read, | |
4712 | .write = ftrace_graph_write, | |
098c879e | 4713 | .llseek = tracing_lseek, |
87827111 | 4714 | .release = ftrace_graph_release, |
ea4e2bc4 | 4715 | }; |
29ad23b0 NK |
4716 | |
4717 | static const struct file_operations ftrace_graph_notrace_fops = { | |
4718 | .open = ftrace_graph_notrace_open, | |
4719 | .read = seq_read, | |
4720 | .write = ftrace_graph_write, | |
098c879e | 4721 | .llseek = tracing_lseek, |
29ad23b0 NK |
4722 | .release = ftrace_graph_release, |
4723 | }; | |
ea4e2bc4 SR |
4724 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
4725 | ||
591dffda SRRH |
4726 | void ftrace_create_filter_files(struct ftrace_ops *ops, |
4727 | struct dentry *parent) | |
4728 | { | |
4729 | ||
4730 | trace_create_file("set_ftrace_filter", 0644, parent, | |
4731 | ops, &ftrace_filter_fops); | |
4732 | ||
4733 | trace_create_file("set_ftrace_notrace", 0644, parent, | |
4734 | ops, &ftrace_notrace_fops); | |
4735 | } | |
4736 | ||
4737 | /* | |
4738 | * The name "destroy_filter_files" is really a misnomer. Although | |
4739 | * in the future, it may actualy delete the files, but this is | |
4740 | * really intended to make sure the ops passed in are disabled | |
4741 | * and that when this function returns, the caller is free to | |
4742 | * free the ops. | |
4743 | * | |
4744 | * The "destroy" name is only to match the "create" name that this | |
4745 | * should be paired with. | |
4746 | */ | |
4747 | void ftrace_destroy_filter_files(struct ftrace_ops *ops) | |
4748 | { | |
4749 | mutex_lock(&ftrace_lock); | |
4750 | if (ops->flags & FTRACE_OPS_FL_ENABLED) | |
4751 | ftrace_shutdown(ops, 0); | |
4752 | ops->flags |= FTRACE_OPS_FL_DELETED; | |
4753 | mutex_unlock(&ftrace_lock); | |
4754 | } | |
4755 | ||
8434dc93 | 4756 | static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer) |
5072c59f | 4757 | { |
5072c59f | 4758 | |
5452af66 FW |
4759 | trace_create_file("available_filter_functions", 0444, |
4760 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 4761 | |
647bcd03 SR |
4762 | trace_create_file("enabled_functions", 0444, |
4763 | d_tracer, NULL, &ftrace_enabled_fops); | |
4764 | ||
591dffda | 4765 | ftrace_create_filter_files(&global_ops, d_tracer); |
ad90c0e3 | 4766 | |
ea4e2bc4 | 4767 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5452af66 | 4768 | trace_create_file("set_graph_function", 0444, d_tracer, |
ea4e2bc4 SR |
4769 | NULL, |
4770 | &ftrace_graph_fops); | |
29ad23b0 NK |
4771 | trace_create_file("set_graph_notrace", 0444, d_tracer, |
4772 | NULL, | |
4773 | &ftrace_graph_notrace_fops); | |
ea4e2bc4 SR |
4774 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
4775 | ||
5072c59f SR |
4776 | return 0; |
4777 | } | |
4778 | ||
9fd49328 | 4779 | static int ftrace_cmp_ips(const void *a, const void *b) |
68950619 | 4780 | { |
9fd49328 SR |
4781 | const unsigned long *ipa = a; |
4782 | const unsigned long *ipb = b; | |
68950619 | 4783 | |
9fd49328 SR |
4784 | if (*ipa > *ipb) |
4785 | return 1; | |
4786 | if (*ipa < *ipb) | |
4787 | return -1; | |
4788 | return 0; | |
4789 | } | |
4790 | ||
4791 | static void ftrace_swap_ips(void *a, void *b, int size) | |
4792 | { | |
4793 | unsigned long *ipa = a; | |
4794 | unsigned long *ipb = b; | |
4795 | unsigned long t; | |
4796 | ||
4797 | t = *ipa; | |
4798 | *ipa = *ipb; | |
4799 | *ipb = t; | |
68950619 SR |
4800 | } |
4801 | ||
5cb084bb | 4802 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 4803 | unsigned long *start, |
68bf21aa SR |
4804 | unsigned long *end) |
4805 | { | |
706c81f8 | 4806 | struct ftrace_page *start_pg; |
a7900875 | 4807 | struct ftrace_page *pg; |
706c81f8 | 4808 | struct dyn_ftrace *rec; |
a7900875 | 4809 | unsigned long count; |
68bf21aa SR |
4810 | unsigned long *p; |
4811 | unsigned long addr; | |
4376cac6 | 4812 | unsigned long flags = 0; /* Shut up gcc */ |
a7900875 SR |
4813 | int ret = -ENOMEM; |
4814 | ||
4815 | count = end - start; | |
4816 | ||
4817 | if (!count) | |
4818 | return 0; | |
4819 | ||
9fd49328 SR |
4820 | sort(start, count, sizeof(*start), |
4821 | ftrace_cmp_ips, ftrace_swap_ips); | |
4822 | ||
706c81f8 SR |
4823 | start_pg = ftrace_allocate_pages(count); |
4824 | if (!start_pg) | |
a7900875 | 4825 | return -ENOMEM; |
68bf21aa | 4826 | |
e6ea44e9 | 4827 | mutex_lock(&ftrace_lock); |
a7900875 | 4828 | |
32082309 SR |
4829 | /* |
4830 | * Core and each module needs their own pages, as | |
4831 | * modules will free them when they are removed. | |
4832 | * Force a new page to be allocated for modules. | |
4833 | */ | |
a7900875 SR |
4834 | if (!mod) { |
4835 | WARN_ON(ftrace_pages || ftrace_pages_start); | |
4836 | /* First initialization */ | |
706c81f8 | 4837 | ftrace_pages = ftrace_pages_start = start_pg; |
a7900875 | 4838 | } else { |
32082309 | 4839 | if (!ftrace_pages) |
a7900875 | 4840 | goto out; |
32082309 | 4841 | |
a7900875 SR |
4842 | if (WARN_ON(ftrace_pages->next)) { |
4843 | /* Hmm, we have free pages? */ | |
4844 | while (ftrace_pages->next) | |
4845 | ftrace_pages = ftrace_pages->next; | |
32082309 | 4846 | } |
a7900875 | 4847 | |
706c81f8 | 4848 | ftrace_pages->next = start_pg; |
32082309 SR |
4849 | } |
4850 | ||
68bf21aa | 4851 | p = start; |
706c81f8 | 4852 | pg = start_pg; |
68bf21aa SR |
4853 | while (p < end) { |
4854 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
4855 | /* |
4856 | * Some architecture linkers will pad between | |
4857 | * the different mcount_loc sections of different | |
4858 | * object files to satisfy alignments. | |
4859 | * Skip any NULL pointers. | |
4860 | */ | |
4861 | if (!addr) | |
4862 | continue; | |
706c81f8 SR |
4863 | |
4864 | if (pg->index == pg->size) { | |
4865 | /* We should have allocated enough */ | |
4866 | if (WARN_ON(!pg->next)) | |
4867 | break; | |
4868 | pg = pg->next; | |
4869 | } | |
4870 | ||
4871 | rec = &pg->records[pg->index++]; | |
4872 | rec->ip = addr; | |
68bf21aa SR |
4873 | } |
4874 | ||
706c81f8 SR |
4875 | /* We should have used all pages */ |
4876 | WARN_ON(pg->next); | |
4877 | ||
4878 | /* Assign the last page to ftrace_pages */ | |
4879 | ftrace_pages = pg; | |
4880 | ||
a4f18ed1 | 4881 | /* |
4376cac6 SR |
4882 | * We only need to disable interrupts on start up |
4883 | * because we are modifying code that an interrupt | |
4884 | * may execute, and the modification is not atomic. | |
4885 | * But for modules, nothing runs the code we modify | |
4886 | * until we are finished with it, and there's no | |
4887 | * reason to cause large interrupt latencies while we do it. | |
a4f18ed1 | 4888 | */ |
4376cac6 SR |
4889 | if (!mod) |
4890 | local_irq_save(flags); | |
1dc43cf0 | 4891 | ftrace_update_code(mod, start_pg); |
4376cac6 SR |
4892 | if (!mod) |
4893 | local_irq_restore(flags); | |
a7900875 SR |
4894 | ret = 0; |
4895 | out: | |
e6ea44e9 | 4896 | mutex_unlock(&ftrace_lock); |
68bf21aa | 4897 | |
a7900875 | 4898 | return ret; |
68bf21aa SR |
4899 | } |
4900 | ||
93eb677d | 4901 | #ifdef CONFIG_MODULES |
32082309 SR |
4902 | |
4903 | #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next) | |
4904 | ||
e7247a15 | 4905 | void ftrace_release_mod(struct module *mod) |
93eb677d SR |
4906 | { |
4907 | struct dyn_ftrace *rec; | |
32082309 | 4908 | struct ftrace_page **last_pg; |
93eb677d | 4909 | struct ftrace_page *pg; |
a7900875 | 4910 | int order; |
93eb677d | 4911 | |
45a4a237 SR |
4912 | mutex_lock(&ftrace_lock); |
4913 | ||
e7247a15 | 4914 | if (ftrace_disabled) |
45a4a237 | 4915 | goto out_unlock; |
93eb677d | 4916 | |
32082309 SR |
4917 | /* |
4918 | * Each module has its own ftrace_pages, remove | |
4919 | * them from the list. | |
4920 | */ | |
4921 | last_pg = &ftrace_pages_start; | |
4922 | for (pg = ftrace_pages_start; pg; pg = *last_pg) { | |
4923 | rec = &pg->records[0]; | |
e7247a15 | 4924 | if (within_module_core(rec->ip, mod)) { |
93eb677d | 4925 | /* |
32082309 SR |
4926 | * As core pages are first, the first |
4927 | * page should never be a module page. | |
93eb677d | 4928 | */ |
32082309 SR |
4929 | if (WARN_ON(pg == ftrace_pages_start)) |
4930 | goto out_unlock; | |
4931 | ||
4932 | /* Check if we are deleting the last page */ | |
4933 | if (pg == ftrace_pages) | |
4934 | ftrace_pages = next_to_ftrace_page(last_pg); | |
4935 | ||
4936 | *last_pg = pg->next; | |
a7900875 SR |
4937 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
4938 | free_pages((unsigned long)pg->records, order); | |
4939 | kfree(pg); | |
32082309 SR |
4940 | } else |
4941 | last_pg = &pg->next; | |
4942 | } | |
45a4a237 | 4943 | out_unlock: |
93eb677d SR |
4944 | mutex_unlock(&ftrace_lock); |
4945 | } | |
4946 | ||
4947 | static void ftrace_init_module(struct module *mod, | |
4948 | unsigned long *start, unsigned long *end) | |
90d595fe | 4949 | { |
00fd61ae | 4950 | if (ftrace_disabled || start == end) |
fed1939c | 4951 | return; |
5cb084bb | 4952 | ftrace_process_locs(mod, start, end); |
90d595fe SR |
4953 | } |
4954 | ||
a949ae56 | 4955 | void ftrace_module_init(struct module *mod) |
93eb677d | 4956 | { |
a949ae56 SRRH |
4957 | ftrace_init_module(mod, mod->ftrace_callsites, |
4958 | mod->ftrace_callsites + | |
4959 | mod->num_ftrace_callsites); | |
8c189ea6 SRRH |
4960 | } |
4961 | ||
4962 | static int ftrace_module_notify_exit(struct notifier_block *self, | |
4963 | unsigned long val, void *data) | |
4964 | { | |
4965 | struct module *mod = data; | |
4966 | ||
4967 | if (val == MODULE_STATE_GOING) | |
e7247a15 | 4968 | ftrace_release_mod(mod); |
93eb677d SR |
4969 | |
4970 | return 0; | |
4971 | } | |
4972 | #else | |
8c189ea6 SRRH |
4973 | static int ftrace_module_notify_exit(struct notifier_block *self, |
4974 | unsigned long val, void *data) | |
93eb677d SR |
4975 | { |
4976 | return 0; | |
4977 | } | |
4978 | #endif /* CONFIG_MODULES */ | |
4979 | ||
8c189ea6 SRRH |
4980 | struct notifier_block ftrace_module_exit_nb = { |
4981 | .notifier_call = ftrace_module_notify_exit, | |
4982 | .priority = INT_MIN, /* Run after anything that can remove kprobes */ | |
4983 | }; | |
4984 | ||
68bf21aa SR |
4985 | void __init ftrace_init(void) |
4986 | { | |
1dc43cf0 JS |
4987 | extern unsigned long __start_mcount_loc[]; |
4988 | extern unsigned long __stop_mcount_loc[]; | |
3a36cb11 | 4989 | unsigned long count, flags; |
68bf21aa SR |
4990 | int ret; |
4991 | ||
68bf21aa | 4992 | local_irq_save(flags); |
3a36cb11 | 4993 | ret = ftrace_dyn_arch_init(); |
68bf21aa | 4994 | local_irq_restore(flags); |
af64a7cb | 4995 | if (ret) |
68bf21aa SR |
4996 | goto failed; |
4997 | ||
4998 | count = __stop_mcount_loc - __start_mcount_loc; | |
c867ccd8 JS |
4999 | if (!count) { |
5000 | pr_info("ftrace: No functions to be traced?\n"); | |
68bf21aa | 5001 | goto failed; |
c867ccd8 JS |
5002 | } |
5003 | ||
5004 | pr_info("ftrace: allocating %ld entries in %ld pages\n", | |
5005 | count, count / ENTRIES_PER_PAGE + 1); | |
68bf21aa SR |
5006 | |
5007 | last_ftrace_enabled = ftrace_enabled = 1; | |
5008 | ||
5cb084bb | 5009 | ret = ftrace_process_locs(NULL, |
31e88909 | 5010 | __start_mcount_loc, |
68bf21aa SR |
5011 | __stop_mcount_loc); |
5012 | ||
8c189ea6 | 5013 | ret = register_module_notifier(&ftrace_module_exit_nb); |
24ed0c4b | 5014 | if (ret) |
8c189ea6 | 5015 | pr_warning("Failed to register trace ftrace module exit notifier\n"); |
93eb677d | 5016 | |
2af15d6a SR |
5017 | set_ftrace_early_filters(); |
5018 | ||
68bf21aa SR |
5019 | return; |
5020 | failed: | |
5021 | ftrace_disabled = 1; | |
5022 | } | |
68bf21aa | 5023 | |
f3bea491 SRRH |
5024 | /* Do nothing if arch does not support this */ |
5025 | void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops) | |
5026 | { | |
5027 | } | |
5028 | ||
5029 | static void ftrace_update_trampoline(struct ftrace_ops *ops) | |
5030 | { | |
12cce594 SRRH |
5031 | |
5032 | /* | |
5033 | * Currently there's no safe way to free a trampoline when the kernel | |
5034 | * is configured with PREEMPT. That is because a task could be preempted | |
5035 | * when it jumped to the trampoline, it may be preempted for a long time | |
5036 | * depending on the system load, and currently there's no way to know | |
5037 | * when it will be off the trampoline. If the trampoline is freed | |
5038 | * too early, when the task runs again, it will be executing on freed | |
5039 | * memory and crash. | |
5040 | */ | |
5041 | #ifdef CONFIG_PREEMPT | |
f3bea491 SRRH |
5042 | /* Currently, only non dynamic ops can have a trampoline */ |
5043 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC) | |
5044 | return; | |
12cce594 | 5045 | #endif |
f3bea491 SRRH |
5046 | |
5047 | arch_ftrace_update_trampoline(ops); | |
5048 | } | |
5049 | ||
3d083395 | 5050 | #else |
0b6e4d56 | 5051 | |
2b499381 | 5052 | static struct ftrace_ops global_ops = { |
bd69c30b | 5053 | .func = ftrace_stub, |
e3eea140 SRRH |
5054 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | |
5055 | FTRACE_OPS_FL_INITIALIZED | | |
5056 | FTRACE_OPS_FL_PID, | |
bd69c30b SR |
5057 | }; |
5058 | ||
0b6e4d56 FW |
5059 | static int __init ftrace_nodyn_init(void) |
5060 | { | |
5061 | ftrace_enabled = 1; | |
5062 | return 0; | |
5063 | } | |
6f415672 | 5064 | core_initcall(ftrace_nodyn_init); |
0b6e4d56 | 5065 | |
8434dc93 | 5066 | static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; } |
df4fc315 | 5067 | static inline void ftrace_startup_enable(int command) { } |
e1effa01 | 5068 | static inline void ftrace_startup_all(int command) { } |
5a45cfe1 | 5069 | /* Keep as macros so we do not need to define the commands */ |
8a56d776 SRRH |
5070 | # define ftrace_startup(ops, command) \ |
5071 | ({ \ | |
5072 | int ___ret = __register_ftrace_function(ops); \ | |
5073 | if (!___ret) \ | |
5074 | (ops)->flags |= FTRACE_OPS_FL_ENABLED; \ | |
5075 | ___ret; \ | |
3b6cfdb1 | 5076 | }) |
1fcc1553 SRRH |
5077 | # define ftrace_shutdown(ops, command) \ |
5078 | ({ \ | |
5079 | int ___ret = __unregister_ftrace_function(ops); \ | |
5080 | if (!___ret) \ | |
5081 | (ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \ | |
5082 | ___ret; \ | |
5083 | }) | |
8a56d776 | 5084 | |
c7aafc54 IM |
5085 | # define ftrace_startup_sysctl() do { } while (0) |
5086 | # define ftrace_shutdown_sysctl() do { } while (0) | |
b848914c SR |
5087 | |
5088 | static inline int | |
195a8afc | 5089 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
b848914c SR |
5090 | { |
5091 | return 1; | |
5092 | } | |
5093 | ||
f3bea491 SRRH |
5094 | static void ftrace_update_trampoline(struct ftrace_ops *ops) |
5095 | { | |
5096 | } | |
5097 | ||
3d083395 SR |
5098 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
5099 | ||
4104d326 SRRH |
5100 | __init void ftrace_init_global_array_ops(struct trace_array *tr) |
5101 | { | |
5102 | tr->ops = &global_ops; | |
5103 | tr->ops->private = tr; | |
5104 | } | |
5105 | ||
5106 | void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func) | |
5107 | { | |
5108 | /* If we filter on pids, update to use the pid function */ | |
5109 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL) { | |
5110 | if (WARN_ON(tr->ops->func != ftrace_stub)) | |
5111 | printk("ftrace ops had %pS for function\n", | |
5112 | tr->ops->func); | |
4104d326 SRRH |
5113 | } |
5114 | tr->ops->func = func; | |
5115 | tr->ops->private = tr; | |
5116 | } | |
5117 | ||
5118 | void ftrace_reset_array_ops(struct trace_array *tr) | |
5119 | { | |
5120 | tr->ops->func = ftrace_stub; | |
5121 | } | |
5122 | ||
e248491a | 5123 | static void |
2f5f6ad9 | 5124 | ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 5125 | struct ftrace_ops *op, struct pt_regs *regs) |
e248491a | 5126 | { |
e248491a JO |
5127 | if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT))) |
5128 | return; | |
5129 | ||
5130 | /* | |
5131 | * Some of the ops may be dynamically allocated, | |
5132 | * they must be freed after a synchronize_sched(). | |
5133 | */ | |
5134 | preempt_disable_notrace(); | |
5135 | trace_recursion_set(TRACE_CONTROL_BIT); | |
b5aa3a47 SRRH |
5136 | |
5137 | /* | |
5138 | * Control funcs (perf) uses RCU. Only trace if | |
5139 | * RCU is currently active. | |
5140 | */ | |
5141 | if (!rcu_is_watching()) | |
5142 | goto out; | |
5143 | ||
0a016409 | 5144 | do_for_each_ftrace_op(op, ftrace_control_list) { |
395b97a3 SRRH |
5145 | if (!(op->flags & FTRACE_OPS_FL_STUB) && |
5146 | !ftrace_function_local_disabled(op) && | |
195a8afc | 5147 | ftrace_ops_test(op, ip, regs)) |
a1e2e31d | 5148 | op->func(ip, parent_ip, op, regs); |
0a016409 | 5149 | } while_for_each_ftrace_op(op); |
b5aa3a47 | 5150 | out: |
e248491a JO |
5151 | trace_recursion_clear(TRACE_CONTROL_BIT); |
5152 | preempt_enable_notrace(); | |
5153 | } | |
5154 | ||
5155 | static struct ftrace_ops control_ops = { | |
f04f24fb MH |
5156 | .func = ftrace_ops_control_func, |
5157 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, | |
33b7f99c | 5158 | INIT_OPS_HASH(control_ops) |
e248491a JO |
5159 | }; |
5160 | ||
2f5f6ad9 SR |
5161 | static inline void |
5162 | __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 5163 | struct ftrace_ops *ignored, struct pt_regs *regs) |
b848914c | 5164 | { |
cdbe61bf | 5165 | struct ftrace_ops *op; |
edc15caf | 5166 | int bit; |
b848914c | 5167 | |
edc15caf SR |
5168 | bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX); |
5169 | if (bit < 0) | |
5170 | return; | |
b1cff0ad | 5171 | |
cdbe61bf SR |
5172 | /* |
5173 | * Some of the ops may be dynamically allocated, | |
5174 | * they must be freed after a synchronize_sched(). | |
5175 | */ | |
5176 | preempt_disable_notrace(); | |
0a016409 | 5177 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
4104d326 | 5178 | if (ftrace_ops_test(op, ip, regs)) { |
1d48d596 SRRH |
5179 | if (FTRACE_WARN_ON(!op->func)) { |
5180 | pr_warn("op=%p %pS\n", op, op); | |
4104d326 SRRH |
5181 | goto out; |
5182 | } | |
a1e2e31d | 5183 | op->func(ip, parent_ip, op, regs); |
4104d326 | 5184 | } |
0a016409 | 5185 | } while_for_each_ftrace_op(op); |
4104d326 | 5186 | out: |
cdbe61bf | 5187 | preempt_enable_notrace(); |
edc15caf | 5188 | trace_clear_recursion(bit); |
b848914c SR |
5189 | } |
5190 | ||
2f5f6ad9 SR |
5191 | /* |
5192 | * Some archs only support passing ip and parent_ip. Even though | |
5193 | * the list function ignores the op parameter, we do not want any | |
5194 | * C side effects, where a function is called without the caller | |
5195 | * sending a third parameter. | |
a1e2e31d SR |
5196 | * Archs are to support both the regs and ftrace_ops at the same time. |
5197 | * If they support ftrace_ops, it is assumed they support regs. | |
5198 | * If call backs want to use regs, they must either check for regs | |
06aeaaea MH |
5199 | * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS. |
5200 | * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved. | |
a1e2e31d SR |
5201 | * An architecture can pass partial regs with ftrace_ops and still |
5202 | * set the ARCH_SUPPORT_FTARCE_OPS. | |
2f5f6ad9 SR |
5203 | */ |
5204 | #if ARCH_SUPPORTS_FTRACE_OPS | |
5205 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 5206 | struct ftrace_ops *op, struct pt_regs *regs) |
2f5f6ad9 | 5207 | { |
a1e2e31d | 5208 | __ftrace_ops_list_func(ip, parent_ip, NULL, regs); |
2f5f6ad9 SR |
5209 | } |
5210 | #else | |
5211 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip) | |
5212 | { | |
a1e2e31d | 5213 | __ftrace_ops_list_func(ip, parent_ip, NULL, NULL); |
2f5f6ad9 SR |
5214 | } |
5215 | #endif | |
5216 | ||
f1ff6348 SRRH |
5217 | /* |
5218 | * If there's only one function registered but it does not support | |
5219 | * recursion, this function will be called by the mcount trampoline. | |
5220 | * This function will handle recursion protection. | |
5221 | */ | |
5222 | static void ftrace_ops_recurs_func(unsigned long ip, unsigned long parent_ip, | |
5223 | struct ftrace_ops *op, struct pt_regs *regs) | |
5224 | { | |
5225 | int bit; | |
5226 | ||
5227 | bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX); | |
5228 | if (bit < 0) | |
5229 | return; | |
5230 | ||
5231 | op->func(ip, parent_ip, op, regs); | |
5232 | ||
5233 | trace_clear_recursion(bit); | |
5234 | } | |
5235 | ||
87354059 SRRH |
5236 | /** |
5237 | * ftrace_ops_get_func - get the function a trampoline should call | |
5238 | * @ops: the ops to get the function for | |
5239 | * | |
5240 | * Normally the mcount trampoline will call the ops->func, but there | |
5241 | * are times that it should not. For example, if the ops does not | |
5242 | * have its own recursion protection, then it should call the | |
5243 | * ftrace_ops_recurs_func() instead. | |
5244 | * | |
5245 | * Returns the function that the trampoline should call for @ops. | |
5246 | */ | |
5247 | ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops) | |
5248 | { | |
87354059 SRRH |
5249 | /* |
5250 | * If the func handles its own recursion, call it directly. | |
5251 | * Otherwise call the recursion protected function that | |
5252 | * will call the ftrace ops function. | |
5253 | */ | |
5254 | if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE)) | |
5255 | return ftrace_ops_recurs_func; | |
5256 | ||
5257 | return ops->func; | |
5258 | } | |
5259 | ||
e32d8956 | 5260 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
5261 | { |
5262 | struct task_struct *p; | |
e32d8956 | 5263 | int cpu; |
978f3a45 | 5264 | |
e32d8956 SR |
5265 | get_online_cpus(); |
5266 | for_each_online_cpu(cpu) { | |
5267 | p = idle_task(cpu); | |
978f3a45 | 5268 | clear_tsk_trace_trace(p); |
e32d8956 SR |
5269 | } |
5270 | put_online_cpus(); | |
5271 | } | |
978f3a45 | 5272 | |
e32d8956 SR |
5273 | static void set_ftrace_swapper(void) |
5274 | { | |
5275 | struct task_struct *p; | |
5276 | int cpu; | |
5277 | ||
5278 | get_online_cpus(); | |
5279 | for_each_online_cpu(cpu) { | |
5280 | p = idle_task(cpu); | |
5281 | set_tsk_trace_trace(p); | |
5282 | } | |
5283 | put_online_cpus(); | |
978f3a45 SR |
5284 | } |
5285 | ||
e32d8956 SR |
5286 | static void clear_ftrace_pid(struct pid *pid) |
5287 | { | |
5288 | struct task_struct *p; | |
5289 | ||
229c4ef8 | 5290 | rcu_read_lock(); |
e32d8956 SR |
5291 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
5292 | clear_tsk_trace_trace(p); | |
5293 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
5294 | rcu_read_unlock(); |
5295 | ||
e32d8956 SR |
5296 | put_pid(pid); |
5297 | } | |
5298 | ||
5299 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
5300 | { |
5301 | struct task_struct *p; | |
5302 | ||
229c4ef8 | 5303 | rcu_read_lock(); |
978f3a45 SR |
5304 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
5305 | set_tsk_trace_trace(p); | |
5306 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 5307 | rcu_read_unlock(); |
978f3a45 SR |
5308 | } |
5309 | ||
756d17ee | 5310 | static void clear_ftrace_pid_task(struct pid *pid) |
e32d8956 | 5311 | { |
756d17ee | 5312 | if (pid == ftrace_swapper_pid) |
e32d8956 SR |
5313 | clear_ftrace_swapper(); |
5314 | else | |
756d17ee | 5315 | clear_ftrace_pid(pid); |
e32d8956 SR |
5316 | } |
5317 | ||
5318 | static void set_ftrace_pid_task(struct pid *pid) | |
5319 | { | |
5320 | if (pid == ftrace_swapper_pid) | |
5321 | set_ftrace_swapper(); | |
5322 | else | |
5323 | set_ftrace_pid(pid); | |
5324 | } | |
5325 | ||
756d17ee | 5326 | static int ftrace_pid_add(int p) |
df4fc315 | 5327 | { |
978f3a45 | 5328 | struct pid *pid; |
756d17ee | 5329 | struct ftrace_pid *fpid; |
5330 | int ret = -EINVAL; | |
df4fc315 | 5331 | |
756d17ee | 5332 | mutex_lock(&ftrace_lock); |
df4fc315 | 5333 | |
756d17ee | 5334 | if (!p) |
5335 | pid = ftrace_swapper_pid; | |
5336 | else | |
5337 | pid = find_get_pid(p); | |
df4fc315 | 5338 | |
756d17ee | 5339 | if (!pid) |
5340 | goto out; | |
df4fc315 | 5341 | |
756d17ee | 5342 | ret = 0; |
df4fc315 | 5343 | |
756d17ee | 5344 | list_for_each_entry(fpid, &ftrace_pids, list) |
5345 | if (fpid->pid == pid) | |
5346 | goto out_put; | |
978f3a45 | 5347 | |
756d17ee | 5348 | ret = -ENOMEM; |
df4fc315 | 5349 | |
756d17ee | 5350 | fpid = kmalloc(sizeof(*fpid), GFP_KERNEL); |
5351 | if (!fpid) | |
5352 | goto out_put; | |
df4fc315 | 5353 | |
756d17ee | 5354 | list_add(&fpid->list, &ftrace_pids); |
5355 | fpid->pid = pid; | |
0ef8cde5 | 5356 | |
756d17ee | 5357 | set_ftrace_pid_task(pid); |
978f3a45 | 5358 | |
756d17ee | 5359 | ftrace_update_pid_func(); |
e1effa01 SRRH |
5360 | |
5361 | ftrace_startup_all(0); | |
756d17ee | 5362 | |
5363 | mutex_unlock(&ftrace_lock); | |
5364 | return 0; | |
5365 | ||
5366 | out_put: | |
5367 | if (pid != ftrace_swapper_pid) | |
5368 | put_pid(pid); | |
978f3a45 | 5369 | |
756d17ee | 5370 | out: |
5371 | mutex_unlock(&ftrace_lock); | |
5372 | return ret; | |
5373 | } | |
5374 | ||
5375 | static void ftrace_pid_reset(void) | |
5376 | { | |
5377 | struct ftrace_pid *fpid, *safe; | |
978f3a45 | 5378 | |
756d17ee | 5379 | mutex_lock(&ftrace_lock); |
5380 | list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) { | |
5381 | struct pid *pid = fpid->pid; | |
5382 | ||
5383 | clear_ftrace_pid_task(pid); | |
5384 | ||
5385 | list_del(&fpid->list); | |
5386 | kfree(fpid); | |
df4fc315 SR |
5387 | } |
5388 | ||
df4fc315 | 5389 | ftrace_update_pid_func(); |
e1effa01 | 5390 | ftrace_startup_all(0); |
df4fc315 | 5391 | |
e6ea44e9 | 5392 | mutex_unlock(&ftrace_lock); |
756d17ee | 5393 | } |
df4fc315 | 5394 | |
756d17ee | 5395 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
5396 | { | |
5397 | mutex_lock(&ftrace_lock); | |
5398 | ||
e3eea140 | 5399 | if (!ftrace_pids_enabled() && (!*pos)) |
756d17ee | 5400 | return (void *) 1; |
5401 | ||
5402 | return seq_list_start(&ftrace_pids, *pos); | |
5403 | } | |
5404 | ||
5405 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
5406 | { | |
5407 | if (v == (void *)1) | |
5408 | return NULL; | |
5409 | ||
5410 | return seq_list_next(v, &ftrace_pids, pos); | |
5411 | } | |
5412 | ||
5413 | static void fpid_stop(struct seq_file *m, void *p) | |
5414 | { | |
5415 | mutex_unlock(&ftrace_lock); | |
5416 | } | |
5417 | ||
5418 | static int fpid_show(struct seq_file *m, void *v) | |
5419 | { | |
5420 | const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list); | |
5421 | ||
5422 | if (v == (void *)1) { | |
fa6f0cc7 | 5423 | seq_puts(m, "no pid\n"); |
756d17ee | 5424 | return 0; |
5425 | } | |
5426 | ||
5427 | if (fpid->pid == ftrace_swapper_pid) | |
fa6f0cc7 | 5428 | seq_puts(m, "swapper tasks\n"); |
756d17ee | 5429 | else |
5430 | seq_printf(m, "%u\n", pid_vnr(fpid->pid)); | |
5431 | ||
5432 | return 0; | |
5433 | } | |
5434 | ||
5435 | static const struct seq_operations ftrace_pid_sops = { | |
5436 | .start = fpid_start, | |
5437 | .next = fpid_next, | |
5438 | .stop = fpid_stop, | |
5439 | .show = fpid_show, | |
5440 | }; | |
5441 | ||
5442 | static int | |
5443 | ftrace_pid_open(struct inode *inode, struct file *file) | |
5444 | { | |
5445 | int ret = 0; | |
5446 | ||
5447 | if ((file->f_mode & FMODE_WRITE) && | |
5448 | (file->f_flags & O_TRUNC)) | |
5449 | ftrace_pid_reset(); | |
5450 | ||
5451 | if (file->f_mode & FMODE_READ) | |
5452 | ret = seq_open(file, &ftrace_pid_sops); | |
5453 | ||
5454 | return ret; | |
5455 | } | |
5456 | ||
df4fc315 SR |
5457 | static ssize_t |
5458 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
5459 | size_t cnt, loff_t *ppos) | |
5460 | { | |
457dc928 | 5461 | char buf[64], *tmp; |
df4fc315 SR |
5462 | long val; |
5463 | int ret; | |
5464 | ||
5465 | if (cnt >= sizeof(buf)) | |
5466 | return -EINVAL; | |
5467 | ||
5468 | if (copy_from_user(&buf, ubuf, cnt)) | |
5469 | return -EFAULT; | |
5470 | ||
5471 | buf[cnt] = 0; | |
5472 | ||
756d17ee | 5473 | /* |
5474 | * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid" | |
5475 | * to clean the filter quietly. | |
5476 | */ | |
457dc928 IM |
5477 | tmp = strstrip(buf); |
5478 | if (strlen(tmp) == 0) | |
756d17ee | 5479 | return 1; |
5480 | ||
bcd83ea6 | 5481 | ret = kstrtol(tmp, 10, &val); |
df4fc315 SR |
5482 | if (ret < 0) |
5483 | return ret; | |
5484 | ||
756d17ee | 5485 | ret = ftrace_pid_add(val); |
df4fc315 | 5486 | |
756d17ee | 5487 | return ret ? ret : cnt; |
5488 | } | |
df4fc315 | 5489 | |
756d17ee | 5490 | static int |
5491 | ftrace_pid_release(struct inode *inode, struct file *file) | |
5492 | { | |
5493 | if (file->f_mode & FMODE_READ) | |
5494 | seq_release(inode, file); | |
df4fc315 | 5495 | |
756d17ee | 5496 | return 0; |
df4fc315 SR |
5497 | } |
5498 | ||
5e2336a0 | 5499 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 5500 | .open = ftrace_pid_open, |
5501 | .write = ftrace_pid_write, | |
5502 | .read = seq_read, | |
098c879e | 5503 | .llseek = tracing_lseek, |
756d17ee | 5504 | .release = ftrace_pid_release, |
df4fc315 SR |
5505 | }; |
5506 | ||
8434dc93 | 5507 | static __init int ftrace_init_tracefs(void) |
df4fc315 SR |
5508 | { |
5509 | struct dentry *d_tracer; | |
df4fc315 SR |
5510 | |
5511 | d_tracer = tracing_init_dentry(); | |
14a5ae40 | 5512 | if (IS_ERR(d_tracer)) |
df4fc315 SR |
5513 | return 0; |
5514 | ||
8434dc93 | 5515 | ftrace_init_dyn_tracefs(d_tracer); |
df4fc315 | 5516 | |
5452af66 FW |
5517 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
5518 | NULL, &ftrace_pid_fops); | |
493762fc | 5519 | |
8434dc93 | 5520 | ftrace_profile_tracefs(d_tracer); |
493762fc | 5521 | |
df4fc315 SR |
5522 | return 0; |
5523 | } | |
8434dc93 | 5524 | fs_initcall(ftrace_init_tracefs); |
df4fc315 | 5525 | |
a2bb6a3d | 5526 | /** |
81adbdc0 | 5527 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
5528 | * |
5529 | * This function should be used by panic code. It stops ftrace | |
5530 | * but in a not so nice way. If you need to simply kill ftrace | |
5531 | * from a non-atomic section, use ftrace_kill. | |
5532 | */ | |
81adbdc0 | 5533 | void ftrace_kill(void) |
a2bb6a3d SR |
5534 | { |
5535 | ftrace_disabled = 1; | |
5536 | ftrace_enabled = 0; | |
a2bb6a3d SR |
5537 | clear_ftrace_function(); |
5538 | } | |
5539 | ||
e0a413f6 SR |
5540 | /** |
5541 | * Test if ftrace is dead or not. | |
5542 | */ | |
5543 | int ftrace_is_dead(void) | |
5544 | { | |
5545 | return ftrace_disabled; | |
5546 | } | |
5547 | ||
16444a8a | 5548 | /** |
3d083395 SR |
5549 | * register_ftrace_function - register a function for profiling |
5550 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 5551 | * |
3d083395 SR |
5552 | * Register a function to be called by all functions in the |
5553 | * kernel. | |
5554 | * | |
5555 | * Note: @ops->func and all the functions it calls must be labeled | |
5556 | * with "notrace", otherwise it will go into a | |
5557 | * recursive loop. | |
16444a8a | 5558 | */ |
3d083395 | 5559 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 5560 | { |
45a4a237 | 5561 | int ret = -1; |
4eebcc81 | 5562 | |
f04f24fb MH |
5563 | ftrace_ops_init(ops); |
5564 | ||
e6ea44e9 | 5565 | mutex_lock(&ftrace_lock); |
e7d3737e | 5566 | |
8a56d776 | 5567 | ret = ftrace_startup(ops, 0); |
b848914c | 5568 | |
e6ea44e9 | 5569 | mutex_unlock(&ftrace_lock); |
8d240dd8 | 5570 | |
b0fc494f | 5571 | return ret; |
3d083395 | 5572 | } |
cdbe61bf | 5573 | EXPORT_SYMBOL_GPL(register_ftrace_function); |
3d083395 SR |
5574 | |
5575 | /** | |
32632920 | 5576 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
5577 | * @ops - ops structure that holds the function to unregister |
5578 | * | |
5579 | * Unregister a function that was added to be called by ftrace profiling. | |
5580 | */ | |
5581 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
5582 | { | |
5583 | int ret; | |
5584 | ||
e6ea44e9 | 5585 | mutex_lock(&ftrace_lock); |
8a56d776 | 5586 | ret = ftrace_shutdown(ops, 0); |
e6ea44e9 | 5587 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
5588 | |
5589 | return ret; | |
5590 | } | |
cdbe61bf | 5591 | EXPORT_SYMBOL_GPL(unregister_ftrace_function); |
b0fc494f | 5592 | |
e309b41d | 5593 | int |
b0fc494f | 5594 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
8d65af78 | 5595 | void __user *buffer, size_t *lenp, |
b0fc494f SR |
5596 | loff_t *ppos) |
5597 | { | |
45a4a237 | 5598 | int ret = -ENODEV; |
4eebcc81 | 5599 | |
e6ea44e9 | 5600 | mutex_lock(&ftrace_lock); |
b0fc494f | 5601 | |
45a4a237 SR |
5602 | if (unlikely(ftrace_disabled)) |
5603 | goto out; | |
5604 | ||
5605 | ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
b0fc494f | 5606 | |
a32c7765 | 5607 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
5608 | goto out; |
5609 | ||
a32c7765 | 5610 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f SR |
5611 | |
5612 | if (ftrace_enabled) { | |
5613 | ||
b0fc494f | 5614 | /* we are starting ftrace again */ |
5000c418 JK |
5615 | if (ftrace_ops_list != &ftrace_list_end) |
5616 | update_ftrace_function(); | |
b0fc494f | 5617 | |
524a3868 SRRH |
5618 | ftrace_startup_sysctl(); |
5619 | ||
b0fc494f SR |
5620 | } else { |
5621 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
5622 | ftrace_trace_function = ftrace_stub; | |
5623 | ||
5624 | ftrace_shutdown_sysctl(); | |
5625 | } | |
5626 | ||
5627 | out: | |
e6ea44e9 | 5628 | mutex_unlock(&ftrace_lock); |
3d083395 | 5629 | return ret; |
16444a8a | 5630 | } |
f17845e5 | 5631 | |
fb52607a | 5632 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 5633 | |
5f151b24 SRRH |
5634 | static struct ftrace_ops graph_ops = { |
5635 | .func = ftrace_stub, | |
5636 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | | |
5637 | FTRACE_OPS_FL_INITIALIZED | | |
e3eea140 | 5638 | FTRACE_OPS_FL_PID | |
5f151b24 SRRH |
5639 | FTRACE_OPS_FL_STUB, |
5640 | #ifdef FTRACE_GRAPH_TRAMP_ADDR | |
5641 | .trampoline = FTRACE_GRAPH_TRAMP_ADDR, | |
aec0be2d | 5642 | /* trampoline_size is only needed for dynamically allocated tramps */ |
5f151b24 SRRH |
5643 | #endif |
5644 | ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash) | |
5645 | }; | |
5646 | ||
55577204 SRRH |
5647 | void ftrace_graph_sleep_time_control(bool enable) |
5648 | { | |
5649 | fgraph_sleep_time = enable; | |
5650 | } | |
5651 | ||
5652 | void ftrace_graph_graph_time_control(bool enable) | |
5653 | { | |
5654 | fgraph_graph_time = enable; | |
5655 | } | |
5656 | ||
e49dc19c SR |
5657 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
5658 | { | |
5659 | return 0; | |
5660 | } | |
5661 | ||
287b6e68 FW |
5662 | /* The callbacks that hook a function */ |
5663 | trace_func_graph_ret_t ftrace_graph_return = | |
5664 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 5665 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
23a8e844 | 5666 | static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
5667 | |
5668 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
5669 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
5670 | { | |
5671 | int i; | |
5672 | int ret = 0; | |
5673 | unsigned long flags; | |
5674 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
5675 | struct task_struct *g, *t; | |
5676 | ||
5677 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
5678 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
5679 | * sizeof(struct ftrace_ret_stack), | |
5680 | GFP_KERNEL); | |
5681 | if (!ret_stack_list[i]) { | |
5682 | start = 0; | |
5683 | end = i; | |
5684 | ret = -ENOMEM; | |
5685 | goto free; | |
5686 | } | |
5687 | } | |
5688 | ||
5689 | read_lock_irqsave(&tasklist_lock, flags); | |
5690 | do_each_thread(g, t) { | |
5691 | if (start == end) { | |
5692 | ret = -EAGAIN; | |
5693 | goto unlock; | |
5694 | } | |
5695 | ||
5696 | if (t->ret_stack == NULL) { | |
380c4b14 | 5697 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 5698 | atomic_set(&t->trace_overrun, 0); |
26c01624 SR |
5699 | t->curr_ret_stack = -1; |
5700 | /* Make sure the tasks see the -1 first: */ | |
5701 | smp_wmb(); | |
5702 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
5703 | } |
5704 | } while_each_thread(g, t); | |
5705 | ||
5706 | unlock: | |
5707 | read_unlock_irqrestore(&tasklist_lock, flags); | |
5708 | free: | |
5709 | for (i = start; i < end; i++) | |
5710 | kfree(ret_stack_list[i]); | |
5711 | return ret; | |
5712 | } | |
5713 | ||
8aef2d28 | 5714 | static void |
38516ab5 SR |
5715 | ftrace_graph_probe_sched_switch(void *ignore, |
5716 | struct task_struct *prev, struct task_struct *next) | |
8aef2d28 SR |
5717 | { |
5718 | unsigned long long timestamp; | |
5719 | int index; | |
5720 | ||
be6f164a SR |
5721 | /* |
5722 | * Does the user want to count the time a function was asleep. | |
5723 | * If so, do not update the time stamps. | |
5724 | */ | |
55577204 | 5725 | if (fgraph_sleep_time) |
be6f164a SR |
5726 | return; |
5727 | ||
8aef2d28 SR |
5728 | timestamp = trace_clock_local(); |
5729 | ||
5730 | prev->ftrace_timestamp = timestamp; | |
5731 | ||
5732 | /* only process tasks that we timestamped */ | |
5733 | if (!next->ftrace_timestamp) | |
5734 | return; | |
5735 | ||
5736 | /* | |
5737 | * Update all the counters in next to make up for the | |
5738 | * time next was sleeping. | |
5739 | */ | |
5740 | timestamp -= next->ftrace_timestamp; | |
5741 | ||
5742 | for (index = next->curr_ret_stack; index >= 0; index--) | |
5743 | next->ret_stack[index].calltime += timestamp; | |
5744 | } | |
5745 | ||
f201ae23 | 5746 | /* Allocate a return stack for each task */ |
fb52607a | 5747 | static int start_graph_tracing(void) |
f201ae23 FW |
5748 | { |
5749 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 5750 | int ret, cpu; |
f201ae23 FW |
5751 | |
5752 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
5753 | sizeof(struct ftrace_ret_stack *), | |
5754 | GFP_KERNEL); | |
5755 | ||
5756 | if (!ret_stack_list) | |
5757 | return -ENOMEM; | |
5758 | ||
5b058bcd | 5759 | /* The cpu_boot init_task->ret_stack will never be freed */ |
179c498a SR |
5760 | for_each_online_cpu(cpu) { |
5761 | if (!idle_task(cpu)->ret_stack) | |
868baf07 | 5762 | ftrace_graph_init_idle_task(idle_task(cpu), cpu); |
179c498a | 5763 | } |
5b058bcd | 5764 | |
f201ae23 FW |
5765 | do { |
5766 | ret = alloc_retstack_tasklist(ret_stack_list); | |
5767 | } while (ret == -EAGAIN); | |
5768 | ||
8aef2d28 | 5769 | if (!ret) { |
38516ab5 | 5770 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
8aef2d28 SR |
5771 | if (ret) |
5772 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
5773 | " probe to kernel_sched_switch\n"); | |
5774 | } | |
5775 | ||
f201ae23 FW |
5776 | kfree(ret_stack_list); |
5777 | return ret; | |
5778 | } | |
5779 | ||
4a2b8dda FW |
5780 | /* |
5781 | * Hibernation protection. | |
5782 | * The state of the current task is too much unstable during | |
5783 | * suspend/restore to disk. We want to protect against that. | |
5784 | */ | |
5785 | static int | |
5786 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
5787 | void *unused) | |
5788 | { | |
5789 | switch (state) { | |
5790 | case PM_HIBERNATION_PREPARE: | |
5791 | pause_graph_tracing(); | |
5792 | break; | |
5793 | ||
5794 | case PM_POST_HIBERNATION: | |
5795 | unpause_graph_tracing(); | |
5796 | break; | |
5797 | } | |
5798 | return NOTIFY_DONE; | |
5799 | } | |
5800 | ||
23a8e844 SRRH |
5801 | static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace) |
5802 | { | |
5803 | if (!ftrace_ops_test(&global_ops, trace->func, NULL)) | |
5804 | return 0; | |
5805 | return __ftrace_graph_entry(trace); | |
5806 | } | |
5807 | ||
5808 | /* | |
5809 | * The function graph tracer should only trace the functions defined | |
5810 | * by set_ftrace_filter and set_ftrace_notrace. If another function | |
5811 | * tracer ops is registered, the graph tracer requires testing the | |
5812 | * function against the global ops, and not just trace any function | |
5813 | * that any ftrace_ops registered. | |
5814 | */ | |
5815 | static void update_function_graph_func(void) | |
5816 | { | |
5f151b24 SRRH |
5817 | struct ftrace_ops *op; |
5818 | bool do_test = false; | |
5819 | ||
5820 | /* | |
5821 | * The graph and global ops share the same set of functions | |
5822 | * to test. If any other ops is on the list, then | |
5823 | * the graph tracing needs to test if its the function | |
5824 | * it should call. | |
5825 | */ | |
5826 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
5827 | if (op != &global_ops && op != &graph_ops && | |
5828 | op != &ftrace_list_end) { | |
5829 | do_test = true; | |
5830 | /* in double loop, break out with goto */ | |
5831 | goto out; | |
5832 | } | |
5833 | } while_for_each_ftrace_op(op); | |
5834 | out: | |
5835 | if (do_test) | |
23a8e844 | 5836 | ftrace_graph_entry = ftrace_graph_entry_test; |
5f151b24 SRRH |
5837 | else |
5838 | ftrace_graph_entry = __ftrace_graph_entry; | |
23a8e844 SRRH |
5839 | } |
5840 | ||
8275f69f MK |
5841 | static struct notifier_block ftrace_suspend_notifier = { |
5842 | .notifier_call = ftrace_suspend_notifier_call, | |
5843 | }; | |
5844 | ||
287b6e68 FW |
5845 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
5846 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 5847 | { |
e7d3737e FW |
5848 | int ret = 0; |
5849 | ||
e6ea44e9 | 5850 | mutex_lock(&ftrace_lock); |
e7d3737e | 5851 | |
05ce5818 | 5852 | /* we currently allow only one tracer registered at a time */ |
597af815 | 5853 | if (ftrace_graph_active) { |
05ce5818 SR |
5854 | ret = -EBUSY; |
5855 | goto out; | |
5856 | } | |
5857 | ||
4a2b8dda FW |
5858 | register_pm_notifier(&ftrace_suspend_notifier); |
5859 | ||
597af815 | 5860 | ftrace_graph_active++; |
fb52607a | 5861 | ret = start_graph_tracing(); |
f201ae23 | 5862 | if (ret) { |
597af815 | 5863 | ftrace_graph_active--; |
f201ae23 FW |
5864 | goto out; |
5865 | } | |
e53a6319 | 5866 | |
287b6e68 | 5867 | ftrace_graph_return = retfunc; |
23a8e844 SRRH |
5868 | |
5869 | /* | |
5870 | * Update the indirect function to the entryfunc, and the | |
5871 | * function that gets called to the entry_test first. Then | |
5872 | * call the update fgraph entry function to determine if | |
5873 | * the entryfunc should be called directly or not. | |
5874 | */ | |
5875 | __ftrace_graph_entry = entryfunc; | |
5876 | ftrace_graph_entry = ftrace_graph_entry_test; | |
5877 | update_function_graph_func(); | |
e53a6319 | 5878 | |
5f151b24 | 5879 | ret = ftrace_startup(&graph_ops, FTRACE_START_FUNC_RET); |
e7d3737e | 5880 | out: |
e6ea44e9 | 5881 | mutex_unlock(&ftrace_lock); |
e7d3737e | 5882 | return ret; |
15e6cb36 FW |
5883 | } |
5884 | ||
fb52607a | 5885 | void unregister_ftrace_graph(void) |
15e6cb36 | 5886 | { |
e6ea44e9 | 5887 | mutex_lock(&ftrace_lock); |
e7d3737e | 5888 | |
597af815 | 5889 | if (unlikely(!ftrace_graph_active)) |
2aad1b76 SR |
5890 | goto out; |
5891 | ||
597af815 | 5892 | ftrace_graph_active--; |
287b6e68 | 5893 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 5894 | ftrace_graph_entry = ftrace_graph_entry_stub; |
23a8e844 | 5895 | __ftrace_graph_entry = ftrace_graph_entry_stub; |
5f151b24 | 5896 | ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET); |
4a2b8dda | 5897 | unregister_pm_notifier(&ftrace_suspend_notifier); |
38516ab5 | 5898 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
e7d3737e | 5899 | |
f3bea491 SRRH |
5900 | #ifdef CONFIG_DYNAMIC_FTRACE |
5901 | /* | |
5902 | * Function graph does not allocate the trampoline, but | |
5903 | * other global_ops do. We need to reset the ALLOC_TRAMP flag | |
5904 | * if one was used. | |
5905 | */ | |
5906 | global_ops.trampoline = save_global_trampoline; | |
5907 | if (save_global_flags & FTRACE_OPS_FL_ALLOC_TRAMP) | |
5908 | global_ops.flags |= FTRACE_OPS_FL_ALLOC_TRAMP; | |
5909 | #endif | |
5910 | ||
2aad1b76 | 5911 | out: |
e6ea44e9 | 5912 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 5913 | } |
f201ae23 | 5914 | |
868baf07 SR |
5915 | static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack); |
5916 | ||
5917 | static void | |
5918 | graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack) | |
5919 | { | |
5920 | atomic_set(&t->tracing_graph_pause, 0); | |
5921 | atomic_set(&t->trace_overrun, 0); | |
5922 | t->ftrace_timestamp = 0; | |
25985edc | 5923 | /* make curr_ret_stack visible before we add the ret_stack */ |
868baf07 SR |
5924 | smp_wmb(); |
5925 | t->ret_stack = ret_stack; | |
5926 | } | |
5927 | ||
5928 | /* | |
5929 | * Allocate a return stack for the idle task. May be the first | |
5930 | * time through, or it may be done by CPU hotplug online. | |
5931 | */ | |
5932 | void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) | |
5933 | { | |
5934 | t->curr_ret_stack = -1; | |
5935 | /* | |
5936 | * The idle task has no parent, it either has its own | |
5937 | * stack or no stack at all. | |
5938 | */ | |
5939 | if (t->ret_stack) | |
5940 | WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu)); | |
5941 | ||
5942 | if (ftrace_graph_active) { | |
5943 | struct ftrace_ret_stack *ret_stack; | |
5944 | ||
5945 | ret_stack = per_cpu(idle_ret_stack, cpu); | |
5946 | if (!ret_stack) { | |
5947 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
5948 | * sizeof(struct ftrace_ret_stack), | |
5949 | GFP_KERNEL); | |
5950 | if (!ret_stack) | |
5951 | return; | |
5952 | per_cpu(idle_ret_stack, cpu) = ret_stack; | |
5953 | } | |
5954 | graph_init_task(t, ret_stack); | |
5955 | } | |
5956 | } | |
5957 | ||
f201ae23 | 5958 | /* Allocate a return stack for newly created task */ |
fb52607a | 5959 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 5960 | { |
84047e36 SR |
5961 | /* Make sure we do not use the parent ret_stack */ |
5962 | t->ret_stack = NULL; | |
ea14eb71 | 5963 | t->curr_ret_stack = -1; |
84047e36 | 5964 | |
597af815 | 5965 | if (ftrace_graph_active) { |
82310a32 SR |
5966 | struct ftrace_ret_stack *ret_stack; |
5967 | ||
5968 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
f201ae23 FW |
5969 | * sizeof(struct ftrace_ret_stack), |
5970 | GFP_KERNEL); | |
82310a32 | 5971 | if (!ret_stack) |
f201ae23 | 5972 | return; |
868baf07 | 5973 | graph_init_task(t, ret_stack); |
84047e36 | 5974 | } |
f201ae23 FW |
5975 | } |
5976 | ||
fb52607a | 5977 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 5978 | { |
eae849ca FW |
5979 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
5980 | ||
f201ae23 | 5981 | t->ret_stack = NULL; |
eae849ca FW |
5982 | /* NULL must become visible to IRQs before we free it: */ |
5983 | barrier(); | |
5984 | ||
5985 | kfree(ret_stack); | |
f201ae23 | 5986 | } |
15e6cb36 | 5987 | #endif |