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> | |
29930025 | 18 | #include <linux/sched/task.h> |
3d083395 | 19 | #include <linux/kallsyms.h> |
5072c59f | 20 | #include <linux/seq_file.h> |
4a2b8dda | 21 | #include <linux/suspend.h> |
8434dc93 | 22 | #include <linux/tracefs.h> |
3d083395 | 23 | #include <linux/hardirq.h> |
2d8b820b | 24 | #include <linux/kthread.h> |
5072c59f | 25 | #include <linux/uaccess.h> |
5855fead | 26 | #include <linux/bsearch.h> |
56d82e00 | 27 | #include <linux/module.h> |
2d8b820b | 28 | #include <linux/ftrace.h> |
b0fc494f | 29 | #include <linux/sysctl.h> |
5a0e3ad6 | 30 | #include <linux/slab.h> |
5072c59f | 31 | #include <linux/ctype.h> |
68950619 | 32 | #include <linux/sort.h> |
3d083395 | 33 | #include <linux/list.h> |
59df055f | 34 | #include <linux/hash.h> |
3f379b03 | 35 | #include <linux/rcupdate.h> |
3d083395 | 36 | |
ad8d75ff | 37 | #include <trace/events/sched.h> |
8aef2d28 | 38 | |
b80f0f6c | 39 | #include <asm/sections.h> |
2af15d6a | 40 | #include <asm/setup.h> |
395a59d0 | 41 | |
0706f1c4 | 42 | #include "trace_output.h" |
bac429f0 | 43 | #include "trace_stat.h" |
16444a8a | 44 | |
6912896e | 45 | #define FTRACE_WARN_ON(cond) \ |
0778d9ad SR |
46 | ({ \ |
47 | int ___r = cond; \ | |
48 | if (WARN_ON(___r)) \ | |
6912896e | 49 | ftrace_kill(); \ |
0778d9ad SR |
50 | ___r; \ |
51 | }) | |
6912896e SR |
52 | |
53 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
0778d9ad SR |
54 | ({ \ |
55 | int ___r = cond; \ | |
56 | if (WARN_ON_ONCE(___r)) \ | |
6912896e | 57 | ftrace_kill(); \ |
0778d9ad SR |
58 | ___r; \ |
59 | }) | |
6912896e | 60 | |
8fc0c701 SR |
61 | /* hash bits for specific function selection */ |
62 | #define FTRACE_HASH_BITS 7 | |
63 | #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS) | |
33dc9b12 SR |
64 | #define FTRACE_HASH_DEFAULT_BITS 10 |
65 | #define FTRACE_HASH_MAX_BITS 12 | |
8fc0c701 | 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 | |
345ddcc8 | 94 | static bool ftrace_pids_enabled(struct ftrace_ops *ops) |
e3eea140 | 95 | { |
345ddcc8 SRRH |
96 | struct trace_array *tr; |
97 | ||
98 | if (!(ops->flags & FTRACE_OPS_FL_PID) || !ops->private) | |
99 | return false; | |
100 | ||
101 | tr = ops->private; | |
102 | ||
103 | return tr->function_pids != NULL; | |
e3eea140 SRRH |
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 | |
b848914c | 116 | static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end; |
16444a8a | 117 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
2b499381 | 118 | static struct ftrace_ops global_ops; |
16444a8a | 119 | |
2f5f6ad9 SR |
120 | #if ARCH_SUPPORTS_FTRACE_OPS |
121 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 122 | struct ftrace_ops *op, struct pt_regs *regs); |
2f5f6ad9 SR |
123 | #else |
124 | /* See comment below, where ftrace_ops_list_func is defined */ | |
125 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip); | |
126 | #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops) | |
127 | #endif | |
b848914c | 128 | |
0a016409 SR |
129 | /* |
130 | * Traverse the ftrace_global_list, invoking all entries. The reason that we | |
1bb539ca | 131 | * can use rcu_dereference_raw_notrace() is that elements removed from this list |
0a016409 | 132 | * are simply leaked, so there is no need to interact with a grace-period |
1bb539ca | 133 | * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle |
0a016409 SR |
134 | * concurrent insertions into the ftrace_global_list. |
135 | * | |
136 | * Silly Alpha and silly pointer-speculation compiler optimizations! | |
137 | */ | |
138 | #define do_for_each_ftrace_op(op, list) \ | |
1bb539ca | 139 | op = rcu_dereference_raw_notrace(list); \ |
0a016409 SR |
140 | do |
141 | ||
142 | /* | |
143 | * Optimized for just a single item in the list (as that is the normal case). | |
144 | */ | |
145 | #define while_for_each_ftrace_op(op) \ | |
1bb539ca | 146 | while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \ |
0a016409 SR |
147 | unlikely((op) != &ftrace_list_end)) |
148 | ||
f04f24fb MH |
149 | static inline void ftrace_ops_init(struct ftrace_ops *ops) |
150 | { | |
151 | #ifdef CONFIG_DYNAMIC_FTRACE | |
152 | if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) { | |
33b7f99c SRRH |
153 | mutex_init(&ops->local_hash.regex_lock); |
154 | ops->func_hash = &ops->local_hash; | |
f04f24fb MH |
155 | ops->flags |= FTRACE_OPS_FL_INITIALIZED; |
156 | } | |
157 | #endif | |
158 | } | |
159 | ||
ea701f11 SR |
160 | /** |
161 | * ftrace_nr_registered_ops - return number of ops registered | |
162 | * | |
163 | * Returns the number of ftrace_ops registered and tracing functions | |
164 | */ | |
165 | int ftrace_nr_registered_ops(void) | |
166 | { | |
167 | struct ftrace_ops *ops; | |
168 | int cnt = 0; | |
169 | ||
170 | mutex_lock(&ftrace_lock); | |
171 | ||
172 | for (ops = ftrace_ops_list; | |
173 | ops != &ftrace_list_end; ops = ops->next) | |
174 | cnt++; | |
175 | ||
176 | mutex_unlock(&ftrace_lock); | |
177 | ||
178 | return cnt; | |
179 | } | |
180 | ||
2f5f6ad9 | 181 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 182 | struct ftrace_ops *op, struct pt_regs *regs) |
df4fc315 | 183 | { |
345ddcc8 SRRH |
184 | struct trace_array *tr = op->private; |
185 | ||
186 | if (tr && this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid)) | |
df4fc315 SR |
187 | return; |
188 | ||
e3eea140 | 189 | op->saved_func(ip, parent_ip, op, regs); |
df4fc315 SR |
190 | } |
191 | ||
16444a8a | 192 | /** |
3d083395 | 193 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 194 | * |
3d083395 SR |
195 | * This NULLs the ftrace function and in essence stops |
196 | * tracing. There may be lag | |
16444a8a | 197 | */ |
3d083395 | 198 | void clear_ftrace_function(void) |
16444a8a | 199 | { |
3d083395 SR |
200 | ftrace_trace_function = ftrace_stub; |
201 | } | |
202 | ||
ba27f2bc | 203 | static void per_cpu_ops_disable_all(struct ftrace_ops *ops) |
e248491a JO |
204 | { |
205 | int cpu; | |
206 | ||
207 | for_each_possible_cpu(cpu) | |
208 | *per_cpu_ptr(ops->disabled, cpu) = 1; | |
209 | } | |
210 | ||
ba27f2bc | 211 | static int per_cpu_ops_alloc(struct ftrace_ops *ops) |
e248491a JO |
212 | { |
213 | int __percpu *disabled; | |
214 | ||
ba27f2bc SRRH |
215 | if (WARN_ON_ONCE(!(ops->flags & FTRACE_OPS_FL_PER_CPU))) |
216 | return -EINVAL; | |
217 | ||
e248491a JO |
218 | disabled = alloc_percpu(int); |
219 | if (!disabled) | |
220 | return -ENOMEM; | |
221 | ||
222 | ops->disabled = disabled; | |
ba27f2bc | 223 | per_cpu_ops_disable_all(ops); |
e248491a JO |
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 | /* | |
ba27f2bc | 259 | * If this is a dynamic, RCU, or per CPU ops, or we force list func, |
00ccbf2f SRRH |
260 | * then it needs to call the list anyway. |
261 | */ | |
ba27f2bc SRRH |
262 | if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_PER_CPU | |
263 | FTRACE_OPS_FL_RCU) || FTRACE_FORCE_LIST_FUNC) | |
00ccbf2f SRRH |
264 | return ftrace_ops_list_func; |
265 | ||
266 | return ftrace_ops_get_func(ops); | |
267 | } | |
268 | ||
2b499381 SR |
269 | static void update_ftrace_function(void) |
270 | { | |
271 | ftrace_func_t func; | |
272 | ||
f7aad4e1 SRRH |
273 | /* |
274 | * Prepare the ftrace_ops that the arch callback will use. | |
275 | * If there's only one ftrace_ops registered, the ftrace_ops_list | |
276 | * will point to the ops we want. | |
277 | */ | |
278 | set_function_trace_op = ftrace_ops_list; | |
279 | ||
280 | /* If there's no ftrace_ops registered, just call the stub function */ | |
281 | if (ftrace_ops_list == &ftrace_list_end) { | |
282 | func = ftrace_stub; | |
283 | ||
cdbe61bf SR |
284 | /* |
285 | * If we are at the end of the list and this ops is | |
4740974a SR |
286 | * recursion safe and not dynamic and the arch supports passing ops, |
287 | * then have the mcount trampoline call the function directly. | |
cdbe61bf | 288 | */ |
f7aad4e1 | 289 | } else if (ftrace_ops_list->next == &ftrace_list_end) { |
00ccbf2f | 290 | func = ftrace_ops_get_list_func(ftrace_ops_list); |
f7aad4e1 | 291 | |
2f5f6ad9 SR |
292 | } else { |
293 | /* Just use the default ftrace_ops */ | |
405e1d83 | 294 | set_function_trace_op = &ftrace_list_end; |
b848914c | 295 | func = ftrace_ops_list_func; |
2f5f6ad9 | 296 | } |
2b499381 | 297 | |
5f8bf2d2 SRRH |
298 | update_function_graph_func(); |
299 | ||
405e1d83 SRRH |
300 | /* If there's no change, then do nothing more here */ |
301 | if (ftrace_trace_function == func) | |
302 | return; | |
303 | ||
304 | /* | |
305 | * If we are using the list function, it doesn't care | |
306 | * about the function_trace_ops. | |
307 | */ | |
308 | if (func == ftrace_ops_list_func) { | |
309 | ftrace_trace_function = func; | |
310 | /* | |
311 | * Don't even bother setting function_trace_ops, | |
312 | * it would be racy to do so anyway. | |
313 | */ | |
314 | return; | |
315 | } | |
316 | ||
317 | #ifndef CONFIG_DYNAMIC_FTRACE | |
318 | /* | |
319 | * For static tracing, we need to be a bit more careful. | |
320 | * The function change takes affect immediately. Thus, | |
321 | * we need to coorditate the setting of the function_trace_ops | |
322 | * with the setting of the ftrace_trace_function. | |
323 | * | |
324 | * Set the function to the list ops, which will call the | |
325 | * function we want, albeit indirectly, but it handles the | |
326 | * ftrace_ops and doesn't depend on function_trace_op. | |
327 | */ | |
328 | ftrace_trace_function = ftrace_ops_list_func; | |
329 | /* | |
330 | * Make sure all CPUs see this. Yes this is slow, but static | |
331 | * tracing is slow and nasty to have enabled. | |
332 | */ | |
333 | schedule_on_each_cpu(ftrace_sync); | |
334 | /* Now all cpus are using the list ops. */ | |
335 | function_trace_op = set_function_trace_op; | |
336 | /* Make sure the function_trace_op is visible on all CPUs */ | |
337 | smp_wmb(); | |
338 | /* Nasty way to force a rmb on all cpus */ | |
339 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
340 | /* OK, we are all set to update the ftrace_trace_function now! */ | |
341 | #endif /* !CONFIG_DYNAMIC_FTRACE */ | |
342 | ||
491d0dcf | 343 | ftrace_trace_function = func; |
491d0dcf SR |
344 | } |
345 | ||
7eea4fce JW |
346 | int using_ftrace_ops_list_func(void) |
347 | { | |
348 | return ftrace_trace_function == ftrace_ops_list_func; | |
349 | } | |
350 | ||
2b499381 | 351 | static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
3d083395 | 352 | { |
2b499381 | 353 | ops->next = *list; |
16444a8a | 354 | /* |
b848914c | 355 | * We are entering ops into the list but another |
16444a8a ACM |
356 | * CPU might be walking that list. We need to make sure |
357 | * the ops->next pointer is valid before another CPU sees | |
b848914c | 358 | * the ops pointer included into the list. |
16444a8a | 359 | */ |
2b499381 | 360 | rcu_assign_pointer(*list, ops); |
16444a8a ACM |
361 | } |
362 | ||
2b499381 | 363 | static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
16444a8a | 364 | { |
16444a8a | 365 | struct ftrace_ops **p; |
16444a8a ACM |
366 | |
367 | /* | |
3d083395 SR |
368 | * If we are removing the last function, then simply point |
369 | * to the ftrace_stub. | |
16444a8a | 370 | */ |
2b499381 SR |
371 | if (*list == ops && ops->next == &ftrace_list_end) { |
372 | *list = &ftrace_list_end; | |
e6ea44e9 | 373 | return 0; |
16444a8a ACM |
374 | } |
375 | ||
2b499381 | 376 | for (p = list; *p != &ftrace_list_end; p = &(*p)->next) |
16444a8a ACM |
377 | if (*p == ops) |
378 | break; | |
379 | ||
e6ea44e9 SR |
380 | if (*p != ops) |
381 | return -1; | |
16444a8a ACM |
382 | |
383 | *p = (*p)->next; | |
2b499381 SR |
384 | return 0; |
385 | } | |
16444a8a | 386 | |
f3bea491 SRRH |
387 | static void ftrace_update_trampoline(struct ftrace_ops *ops); |
388 | ||
2b499381 SR |
389 | static int __register_ftrace_function(struct ftrace_ops *ops) |
390 | { | |
591dffda SRRH |
391 | if (ops->flags & FTRACE_OPS_FL_DELETED) |
392 | return -EINVAL; | |
393 | ||
b848914c SR |
394 | if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) |
395 | return -EBUSY; | |
396 | ||
06aeaaea | 397 | #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
08f6fba5 SR |
398 | /* |
399 | * If the ftrace_ops specifies SAVE_REGS, then it only can be used | |
400 | * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set. | |
401 | * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant. | |
402 | */ | |
403 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS && | |
404 | !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)) | |
405 | return -EINVAL; | |
406 | ||
407 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED) | |
408 | ops->flags |= FTRACE_OPS_FL_SAVE_REGS; | |
409 | #endif | |
410 | ||
cdbe61bf SR |
411 | if (!core_kernel_data((unsigned long)ops)) |
412 | ops->flags |= FTRACE_OPS_FL_DYNAMIC; | |
413 | ||
ba27f2bc SRRH |
414 | if (ops->flags & FTRACE_OPS_FL_PER_CPU) { |
415 | if (per_cpu_ops_alloc(ops)) | |
e248491a | 416 | return -ENOMEM; |
ba27f2bc SRRH |
417 | } |
418 | ||
419 | add_ftrace_ops(&ftrace_ops_list, ops); | |
b848914c | 420 | |
e3eea140 SRRH |
421 | /* Always save the function, and reset at unregistering */ |
422 | ops->saved_func = ops->func; | |
423 | ||
345ddcc8 | 424 | if (ftrace_pids_enabled(ops)) |
e3eea140 SRRH |
425 | ops->func = ftrace_pid_func; |
426 | ||
f3bea491 SRRH |
427 | ftrace_update_trampoline(ops); |
428 | ||
2b499381 SR |
429 | if (ftrace_enabled) |
430 | update_ftrace_function(); | |
431 | ||
432 | return 0; | |
433 | } | |
434 | ||
435 | static int __unregister_ftrace_function(struct ftrace_ops *ops) | |
436 | { | |
437 | int ret; | |
438 | ||
b848914c SR |
439 | if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) |
440 | return -EBUSY; | |
441 | ||
ba27f2bc | 442 | ret = remove_ftrace_ops(&ftrace_ops_list, ops); |
b848914c | 443 | |
2b499381 SR |
444 | if (ret < 0) |
445 | return ret; | |
b848914c | 446 | |
491d0dcf SR |
447 | if (ftrace_enabled) |
448 | update_ftrace_function(); | |
16444a8a | 449 | |
e3eea140 SRRH |
450 | ops->func = ops->saved_func; |
451 | ||
e6ea44e9 | 452 | return 0; |
3d083395 SR |
453 | } |
454 | ||
df4fc315 SR |
455 | static void ftrace_update_pid_func(void) |
456 | { | |
e3eea140 SRRH |
457 | struct ftrace_ops *op; |
458 | ||
491d0dcf | 459 | /* Only do something if we are tracing something */ |
df4fc315 | 460 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 461 | return; |
df4fc315 | 462 | |
e3eea140 SRRH |
463 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
464 | if (op->flags & FTRACE_OPS_FL_PID) { | |
345ddcc8 SRRH |
465 | op->func = ftrace_pids_enabled(op) ? |
466 | ftrace_pid_func : op->saved_func; | |
e3eea140 SRRH |
467 | ftrace_update_trampoline(op); |
468 | } | |
469 | } while_for_each_ftrace_op(op); | |
470 | ||
491d0dcf | 471 | update_ftrace_function(); |
df4fc315 SR |
472 | } |
473 | ||
493762fc SR |
474 | #ifdef CONFIG_FUNCTION_PROFILER |
475 | struct ftrace_profile { | |
476 | struct hlist_node node; | |
477 | unsigned long ip; | |
478 | unsigned long counter; | |
0706f1c4 SR |
479 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
480 | unsigned long long time; | |
e330b3bc | 481 | unsigned long long time_squared; |
0706f1c4 | 482 | #endif |
8fc0c701 SR |
483 | }; |
484 | ||
493762fc SR |
485 | struct ftrace_profile_page { |
486 | struct ftrace_profile_page *next; | |
487 | unsigned long index; | |
488 | struct ftrace_profile records[]; | |
d61f82d0 SR |
489 | }; |
490 | ||
cafb168a SR |
491 | struct ftrace_profile_stat { |
492 | atomic_t disabled; | |
493 | struct hlist_head *hash; | |
494 | struct ftrace_profile_page *pages; | |
495 | struct ftrace_profile_page *start; | |
496 | struct tracer_stat stat; | |
497 | }; | |
498 | ||
493762fc SR |
499 | #define PROFILE_RECORDS_SIZE \ |
500 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 501 | |
493762fc SR |
502 | #define PROFILES_PER_PAGE \ |
503 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 504 | |
fb9fb015 SR |
505 | static int ftrace_profile_enabled __read_mostly; |
506 | ||
507 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
508 | static DEFINE_MUTEX(ftrace_profile_lock); |
509 | ||
cafb168a | 510 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc | 511 | |
20079ebe NK |
512 | #define FTRACE_PROFILE_HASH_BITS 10 |
513 | #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS) | |
493762fc | 514 | |
bac429f0 SR |
515 | static void * |
516 | function_stat_next(void *v, int idx) | |
517 | { | |
493762fc SR |
518 | struct ftrace_profile *rec = v; |
519 | struct ftrace_profile_page *pg; | |
bac429f0 | 520 | |
493762fc | 521 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
522 | |
523 | again: | |
0296e425 LZ |
524 | if (idx != 0) |
525 | rec++; | |
526 | ||
bac429f0 SR |
527 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
528 | pg = pg->next; | |
529 | if (!pg) | |
530 | return NULL; | |
531 | rec = &pg->records[0]; | |
493762fc SR |
532 | if (!rec->counter) |
533 | goto again; | |
bac429f0 SR |
534 | } |
535 | ||
bac429f0 SR |
536 | return rec; |
537 | } | |
538 | ||
539 | static void *function_stat_start(struct tracer_stat *trace) | |
540 | { | |
cafb168a SR |
541 | struct ftrace_profile_stat *stat = |
542 | container_of(trace, struct ftrace_profile_stat, stat); | |
543 | ||
544 | if (!stat || !stat->start) | |
545 | return NULL; | |
546 | ||
547 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
548 | } |
549 | ||
0706f1c4 SR |
550 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
551 | /* function graph compares on total time */ | |
552 | static int function_stat_cmp(void *p1, void *p2) | |
553 | { | |
554 | struct ftrace_profile *a = p1; | |
555 | struct ftrace_profile *b = p2; | |
556 | ||
557 | if (a->time < b->time) | |
558 | return -1; | |
559 | if (a->time > b->time) | |
560 | return 1; | |
561 | else | |
562 | return 0; | |
563 | } | |
564 | #else | |
565 | /* not function graph compares against hits */ | |
bac429f0 SR |
566 | static int function_stat_cmp(void *p1, void *p2) |
567 | { | |
493762fc SR |
568 | struct ftrace_profile *a = p1; |
569 | struct ftrace_profile *b = p2; | |
bac429f0 SR |
570 | |
571 | if (a->counter < b->counter) | |
572 | return -1; | |
573 | if (a->counter > b->counter) | |
574 | return 1; | |
575 | else | |
576 | return 0; | |
577 | } | |
0706f1c4 | 578 | #endif |
bac429f0 SR |
579 | |
580 | static int function_stat_headers(struct seq_file *m) | |
581 | { | |
0706f1c4 | 582 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
fa6f0cc7 RV |
583 | seq_puts(m, " Function " |
584 | "Hit Time Avg s^2\n" | |
585 | " -------- " | |
586 | "--- ---- --- ---\n"); | |
0706f1c4 | 587 | #else |
fa6f0cc7 RV |
588 | seq_puts(m, " Function Hit\n" |
589 | " -------- ---\n"); | |
0706f1c4 | 590 | #endif |
bac429f0 SR |
591 | return 0; |
592 | } | |
593 | ||
594 | static int function_stat_show(struct seq_file *m, void *v) | |
595 | { | |
493762fc | 596 | struct ftrace_profile *rec = v; |
bac429f0 | 597 | char str[KSYM_SYMBOL_LEN]; |
3aaba20f | 598 | int ret = 0; |
0706f1c4 | 599 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
600 | static struct trace_seq s; |
601 | unsigned long long avg; | |
e330b3bc | 602 | unsigned long long stddev; |
0706f1c4 | 603 | #endif |
3aaba20f LZ |
604 | mutex_lock(&ftrace_profile_lock); |
605 | ||
606 | /* we raced with function_profile_reset() */ | |
607 | if (unlikely(rec->counter == 0)) { | |
608 | ret = -EBUSY; | |
609 | goto out; | |
610 | } | |
bac429f0 | 611 | |
8e436ca0 UT |
612 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
613 | avg = rec->time; | |
614 | do_div(avg, rec->counter); | |
615 | if (tracing_thresh && (avg < tracing_thresh)) | |
616 | goto out; | |
617 | #endif | |
618 | ||
bac429f0 | 619 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
0706f1c4 SR |
620 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
621 | ||
622 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
fa6f0cc7 | 623 | seq_puts(m, " "); |
34886c8b | 624 | |
e330b3bc CD |
625 | /* Sample standard deviation (s^2) */ |
626 | if (rec->counter <= 1) | |
627 | stddev = 0; | |
628 | else { | |
52d85d76 JL |
629 | /* |
630 | * Apply Welford's method: | |
631 | * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2) | |
632 | */ | |
633 | stddev = rec->counter * rec->time_squared - | |
634 | rec->time * rec->time; | |
635 | ||
e330b3bc CD |
636 | /* |
637 | * Divide only 1000 for ns^2 -> us^2 conversion. | |
638 | * trace_print_graph_duration will divide 1000 again. | |
639 | */ | |
52d85d76 | 640 | do_div(stddev, rec->counter * (rec->counter - 1) * 1000); |
e330b3bc CD |
641 | } |
642 | ||
34886c8b SR |
643 | trace_seq_init(&s); |
644 | trace_print_graph_duration(rec->time, &s); | |
645 | trace_seq_puts(&s, " "); | |
646 | trace_print_graph_duration(avg, &s); | |
e330b3bc CD |
647 | trace_seq_puts(&s, " "); |
648 | trace_print_graph_duration(stddev, &s); | |
0706f1c4 | 649 | trace_print_seq(m, &s); |
0706f1c4 SR |
650 | #endif |
651 | seq_putc(m, '\n'); | |
3aaba20f LZ |
652 | out: |
653 | mutex_unlock(&ftrace_profile_lock); | |
bac429f0 | 654 | |
3aaba20f | 655 | return ret; |
bac429f0 SR |
656 | } |
657 | ||
cafb168a | 658 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 659 | { |
493762fc | 660 | struct ftrace_profile_page *pg; |
bac429f0 | 661 | |
cafb168a | 662 | pg = stat->pages = stat->start; |
bac429f0 | 663 | |
493762fc SR |
664 | while (pg) { |
665 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
666 | pg->index = 0; | |
667 | pg = pg->next; | |
bac429f0 SR |
668 | } |
669 | ||
cafb168a | 670 | memset(stat->hash, 0, |
493762fc SR |
671 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
672 | } | |
bac429f0 | 673 | |
cafb168a | 674 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
675 | { |
676 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
677 | int functions; |
678 | int pages; | |
493762fc | 679 | int i; |
bac429f0 | 680 | |
493762fc | 681 | /* If we already allocated, do nothing */ |
cafb168a | 682 | if (stat->pages) |
493762fc | 683 | return 0; |
bac429f0 | 684 | |
cafb168a SR |
685 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
686 | if (!stat->pages) | |
493762fc | 687 | return -ENOMEM; |
bac429f0 | 688 | |
318e0a73 SR |
689 | #ifdef CONFIG_DYNAMIC_FTRACE |
690 | functions = ftrace_update_tot_cnt; | |
691 | #else | |
692 | /* | |
693 | * We do not know the number of functions that exist because | |
694 | * dynamic tracing is what counts them. With past experience | |
695 | * we have around 20K functions. That should be more than enough. | |
696 | * It is highly unlikely we will execute every function in | |
697 | * the kernel. | |
698 | */ | |
699 | functions = 20000; | |
700 | #endif | |
701 | ||
cafb168a | 702 | pg = stat->start = stat->pages; |
bac429f0 | 703 | |
318e0a73 SR |
704 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
705 | ||
39e30cd1 | 706 | for (i = 1; i < pages; i++) { |
493762fc | 707 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 708 | if (!pg->next) |
318e0a73 | 709 | goto out_free; |
493762fc SR |
710 | pg = pg->next; |
711 | } | |
712 | ||
713 | return 0; | |
318e0a73 SR |
714 | |
715 | out_free: | |
716 | pg = stat->start; | |
717 | while (pg) { | |
718 | unsigned long tmp = (unsigned long)pg; | |
719 | ||
720 | pg = pg->next; | |
721 | free_page(tmp); | |
722 | } | |
723 | ||
318e0a73 SR |
724 | stat->pages = NULL; |
725 | stat->start = NULL; | |
726 | ||
727 | return -ENOMEM; | |
bac429f0 SR |
728 | } |
729 | ||
cafb168a | 730 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 731 | { |
cafb168a | 732 | struct ftrace_profile_stat *stat; |
493762fc | 733 | int size; |
bac429f0 | 734 | |
cafb168a SR |
735 | stat = &per_cpu(ftrace_profile_stats, cpu); |
736 | ||
737 | if (stat->hash) { | |
493762fc | 738 | /* If the profile is already created, simply reset it */ |
cafb168a | 739 | ftrace_profile_reset(stat); |
493762fc SR |
740 | return 0; |
741 | } | |
bac429f0 | 742 | |
493762fc SR |
743 | /* |
744 | * We are profiling all functions, but usually only a few thousand | |
745 | * functions are hit. We'll make a hash of 1024 items. | |
746 | */ | |
747 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 748 | |
cafb168a | 749 | stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
493762fc | 750 | |
cafb168a | 751 | if (!stat->hash) |
493762fc SR |
752 | return -ENOMEM; |
753 | ||
318e0a73 | 754 | /* Preallocate the function profiling pages */ |
cafb168a SR |
755 | if (ftrace_profile_pages_init(stat) < 0) { |
756 | kfree(stat->hash); | |
757 | stat->hash = NULL; | |
493762fc SR |
758 | return -ENOMEM; |
759 | } | |
760 | ||
761 | return 0; | |
bac429f0 SR |
762 | } |
763 | ||
cafb168a SR |
764 | static int ftrace_profile_init(void) |
765 | { | |
766 | int cpu; | |
767 | int ret = 0; | |
768 | ||
c4602c1c | 769 | for_each_possible_cpu(cpu) { |
cafb168a SR |
770 | ret = ftrace_profile_init_cpu(cpu); |
771 | if (ret) | |
772 | break; | |
773 | } | |
774 | ||
775 | return ret; | |
776 | } | |
777 | ||
493762fc | 778 | /* interrupts must be disabled */ |
cafb168a SR |
779 | static struct ftrace_profile * |
780 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 781 | { |
493762fc | 782 | struct ftrace_profile *rec; |
bac429f0 | 783 | struct hlist_head *hhd; |
bac429f0 SR |
784 | unsigned long key; |
785 | ||
20079ebe | 786 | key = hash_long(ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 787 | hhd = &stat->hash[key]; |
bac429f0 SR |
788 | |
789 | if (hlist_empty(hhd)) | |
790 | return NULL; | |
791 | ||
1bb539ca | 792 | hlist_for_each_entry_rcu_notrace(rec, hhd, node) { |
bac429f0 | 793 | if (rec->ip == ip) |
493762fc SR |
794 | return rec; |
795 | } | |
796 | ||
797 | return NULL; | |
798 | } | |
799 | ||
cafb168a SR |
800 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
801 | struct ftrace_profile *rec) | |
493762fc SR |
802 | { |
803 | unsigned long key; | |
804 | ||
20079ebe | 805 | key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS); |
cafb168a | 806 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
807 | } |
808 | ||
318e0a73 SR |
809 | /* |
810 | * The memory is already allocated, this simply finds a new record to use. | |
811 | */ | |
493762fc | 812 | static struct ftrace_profile * |
318e0a73 | 813 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
814 | { |
815 | struct ftrace_profile *rec = NULL; | |
816 | ||
318e0a73 | 817 | /* prevent recursion (from NMIs) */ |
cafb168a | 818 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
819 | goto out; |
820 | ||
493762fc | 821 | /* |
318e0a73 SR |
822 | * Try to find the function again since an NMI |
823 | * could have added it | |
493762fc | 824 | */ |
cafb168a | 825 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 826 | if (rec) |
cafb168a | 827 | goto out; |
493762fc | 828 | |
cafb168a SR |
829 | if (stat->pages->index == PROFILES_PER_PAGE) { |
830 | if (!stat->pages->next) | |
831 | goto out; | |
832 | stat->pages = stat->pages->next; | |
bac429f0 | 833 | } |
493762fc | 834 | |
cafb168a | 835 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 836 | rec->ip = ip; |
cafb168a | 837 | ftrace_add_profile(stat, rec); |
493762fc | 838 | |
bac429f0 | 839 | out: |
cafb168a | 840 | atomic_dec(&stat->disabled); |
bac429f0 SR |
841 | |
842 | return rec; | |
843 | } | |
844 | ||
845 | static void | |
2f5f6ad9 | 846 | function_profile_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 847 | struct ftrace_ops *ops, struct pt_regs *regs) |
bac429f0 | 848 | { |
cafb168a | 849 | struct ftrace_profile_stat *stat; |
493762fc | 850 | struct ftrace_profile *rec; |
bac429f0 SR |
851 | unsigned long flags; |
852 | ||
853 | if (!ftrace_profile_enabled) | |
854 | return; | |
855 | ||
856 | local_irq_save(flags); | |
cafb168a | 857 | |
bdffd893 | 858 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 859 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
860 | goto out; |
861 | ||
862 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 863 | if (!rec) { |
318e0a73 | 864 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
865 | if (!rec) |
866 | goto out; | |
867 | } | |
bac429f0 SR |
868 | |
869 | rec->counter++; | |
870 | out: | |
871 | local_irq_restore(flags); | |
872 | } | |
873 | ||
0706f1c4 SR |
874 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
875 | static int profile_graph_entry(struct ftrace_graph_ent *trace) | |
876 | { | |
8861dd30 NK |
877 | int index = trace->depth; |
878 | ||
a1e2e31d | 879 | function_profile_call(trace->func, 0, NULL, NULL); |
8861dd30 NK |
880 | |
881 | if (index >= 0 && index < FTRACE_RETFUNC_DEPTH) | |
882 | current->ret_stack[index].subtime = 0; | |
883 | ||
0706f1c4 SR |
884 | return 1; |
885 | } | |
886 | ||
887 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
888 | { | |
cafb168a | 889 | struct ftrace_profile_stat *stat; |
a2a16d6a | 890 | unsigned long long calltime; |
0706f1c4 | 891 | struct ftrace_profile *rec; |
cafb168a | 892 | unsigned long flags; |
0706f1c4 SR |
893 | |
894 | local_irq_save(flags); | |
bdffd893 | 895 | stat = this_cpu_ptr(&ftrace_profile_stats); |
0f6ce3de | 896 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
897 | goto out; |
898 | ||
37e44bc5 SR |
899 | /* If the calltime was zero'd ignore it */ |
900 | if (!trace->calltime) | |
901 | goto out; | |
902 | ||
a2a16d6a SR |
903 | calltime = trace->rettime - trace->calltime; |
904 | ||
55577204 | 905 | if (!fgraph_graph_time) { |
a2a16d6a SR |
906 | int index; |
907 | ||
908 | index = trace->depth; | |
909 | ||
910 | /* Append this call time to the parent time to subtract */ | |
911 | if (index) | |
912 | current->ret_stack[index - 1].subtime += calltime; | |
913 | ||
914 | if (current->ret_stack[index].subtime < calltime) | |
915 | calltime -= current->ret_stack[index].subtime; | |
916 | else | |
917 | calltime = 0; | |
918 | } | |
919 | ||
cafb168a | 920 | rec = ftrace_find_profiled_func(stat, trace->func); |
e330b3bc | 921 | if (rec) { |
a2a16d6a | 922 | rec->time += calltime; |
e330b3bc CD |
923 | rec->time_squared += calltime * calltime; |
924 | } | |
a2a16d6a | 925 | |
cafb168a | 926 | out: |
0706f1c4 SR |
927 | local_irq_restore(flags); |
928 | } | |
929 | ||
930 | static int register_ftrace_profiler(void) | |
931 | { | |
932 | return register_ftrace_graph(&profile_graph_return, | |
933 | &profile_graph_entry); | |
934 | } | |
935 | ||
936 | static void unregister_ftrace_profiler(void) | |
937 | { | |
938 | unregister_ftrace_graph(); | |
939 | } | |
940 | #else | |
bd38c0e6 | 941 | static struct ftrace_ops ftrace_profile_ops __read_mostly = { |
fb9fb015 | 942 | .func = function_profile_call, |
f04f24fb | 943 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED, |
33b7f99c | 944 | INIT_OPS_HASH(ftrace_profile_ops) |
bac429f0 SR |
945 | }; |
946 | ||
0706f1c4 SR |
947 | static int register_ftrace_profiler(void) |
948 | { | |
949 | return register_ftrace_function(&ftrace_profile_ops); | |
950 | } | |
951 | ||
952 | static void unregister_ftrace_profiler(void) | |
953 | { | |
954 | unregister_ftrace_function(&ftrace_profile_ops); | |
955 | } | |
956 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
957 | ||
bac429f0 SR |
958 | static ssize_t |
959 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
960 | size_t cnt, loff_t *ppos) | |
961 | { | |
962 | unsigned long val; | |
bac429f0 SR |
963 | int ret; |
964 | ||
22fe9b54 PH |
965 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
966 | if (ret) | |
bac429f0 SR |
967 | return ret; |
968 | ||
969 | val = !!val; | |
970 | ||
971 | mutex_lock(&ftrace_profile_lock); | |
972 | if (ftrace_profile_enabled ^ val) { | |
973 | if (val) { | |
493762fc SR |
974 | ret = ftrace_profile_init(); |
975 | if (ret < 0) { | |
976 | cnt = ret; | |
977 | goto out; | |
978 | } | |
979 | ||
0706f1c4 SR |
980 | ret = register_ftrace_profiler(); |
981 | if (ret < 0) { | |
982 | cnt = ret; | |
983 | goto out; | |
984 | } | |
bac429f0 SR |
985 | ftrace_profile_enabled = 1; |
986 | } else { | |
987 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
988 | /* |
989 | * unregister_ftrace_profiler calls stop_machine | |
990 | * so this acts like an synchronize_sched. | |
991 | */ | |
0706f1c4 | 992 | unregister_ftrace_profiler(); |
bac429f0 SR |
993 | } |
994 | } | |
493762fc | 995 | out: |
bac429f0 SR |
996 | mutex_unlock(&ftrace_profile_lock); |
997 | ||
cf8517cf | 998 | *ppos += cnt; |
bac429f0 SR |
999 | |
1000 | return cnt; | |
1001 | } | |
1002 | ||
493762fc SR |
1003 | static ssize_t |
1004 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
1005 | size_t cnt, loff_t *ppos) | |
1006 | { | |
fb9fb015 | 1007 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
1008 | int r; |
1009 | ||
1010 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
1011 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
1012 | } | |
1013 | ||
bac429f0 SR |
1014 | static const struct file_operations ftrace_profile_fops = { |
1015 | .open = tracing_open_generic, | |
1016 | .read = ftrace_profile_read, | |
1017 | .write = ftrace_profile_write, | |
6038f373 | 1018 | .llseek = default_llseek, |
bac429f0 SR |
1019 | }; |
1020 | ||
cafb168a SR |
1021 | /* used to initialize the real stat files */ |
1022 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
1023 | .name = "functions", |
1024 | .stat_start = function_stat_start, | |
1025 | .stat_next = function_stat_next, | |
1026 | .stat_cmp = function_stat_cmp, | |
1027 | .stat_headers = function_stat_headers, | |
1028 | .stat_show = function_stat_show | |
cafb168a SR |
1029 | }; |
1030 | ||
8434dc93 | 1031 | static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
bac429f0 | 1032 | { |
cafb168a | 1033 | struct ftrace_profile_stat *stat; |
bac429f0 | 1034 | struct dentry *entry; |
cafb168a | 1035 | char *name; |
bac429f0 | 1036 | int ret; |
cafb168a SR |
1037 | int cpu; |
1038 | ||
1039 | for_each_possible_cpu(cpu) { | |
1040 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
1041 | ||
6363c6b5 | 1042 | name = kasprintf(GFP_KERNEL, "function%d", cpu); |
cafb168a SR |
1043 | if (!name) { |
1044 | /* | |
1045 | * The files created are permanent, if something happens | |
1046 | * we still do not free memory. | |
1047 | */ | |
cafb168a SR |
1048 | WARN(1, |
1049 | "Could not allocate stat file for cpu %d\n", | |
1050 | cpu); | |
1051 | return; | |
1052 | } | |
1053 | stat->stat = function_stats; | |
cafb168a SR |
1054 | stat->stat.name = name; |
1055 | ret = register_stat_tracer(&stat->stat); | |
1056 | if (ret) { | |
1057 | WARN(1, | |
1058 | "Could not register function stat for cpu %d\n", | |
1059 | cpu); | |
1060 | kfree(name); | |
1061 | return; | |
1062 | } | |
bac429f0 SR |
1063 | } |
1064 | ||
8434dc93 | 1065 | entry = tracefs_create_file("function_profile_enabled", 0644, |
bac429f0 SR |
1066 | d_tracer, NULL, &ftrace_profile_fops); |
1067 | if (!entry) | |
a395d6a7 | 1068 | pr_warn("Could not create tracefs 'function_profile_enabled' entry\n"); |
bac429f0 SR |
1069 | } |
1070 | ||
bac429f0 | 1071 | #else /* CONFIG_FUNCTION_PROFILER */ |
8434dc93 | 1072 | static __init void ftrace_profile_tracefs(struct dentry *d_tracer) |
bac429f0 SR |
1073 | { |
1074 | } | |
bac429f0 SR |
1075 | #endif /* CONFIG_FUNCTION_PROFILER */ |
1076 | ||
493762fc SR |
1077 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; |
1078 | ||
1619dc3f PA |
1079 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
1080 | static int ftrace_graph_active; | |
1081 | #else | |
1082 | # define ftrace_graph_active 0 | |
1083 | #endif | |
1084 | ||
493762fc SR |
1085 | #ifdef CONFIG_DYNAMIC_FTRACE |
1086 | ||
79922b80 SRRH |
1087 | static struct ftrace_ops *removed_ops; |
1088 | ||
e1effa01 SRRH |
1089 | /* |
1090 | * Set when doing a global update, like enabling all recs or disabling them. | |
1091 | * It is not set when just updating a single ftrace_ops. | |
1092 | */ | |
1093 | static bool update_all_ops; | |
1094 | ||
493762fc SR |
1095 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
1096 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
1097 | #endif | |
1098 | ||
1099 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; | |
1100 | ||
1101 | struct ftrace_func_probe { | |
1102 | struct hlist_node node; | |
1103 | struct ftrace_probe_ops *ops; | |
493762fc | 1104 | unsigned long ip; |
7818b388 | 1105 | struct list_head free_list; |
493762fc SR |
1106 | }; |
1107 | ||
b448c4e3 SR |
1108 | struct ftrace_func_entry { |
1109 | struct hlist_node hlist; | |
1110 | unsigned long ip; | |
1111 | }; | |
1112 | ||
33dc9b12 SR |
1113 | /* |
1114 | * We make these constant because no one should touch them, | |
1115 | * but they are used as the default "empty hash", to avoid allocating | |
1116 | * it all the time. These are in a read only section such that if | |
1117 | * anyone does try to modify it, it will cause an exception. | |
1118 | */ | |
1119 | static const struct hlist_head empty_buckets[1]; | |
1120 | static const struct ftrace_hash empty_hash = { | |
1121 | .buckets = (struct hlist_head *)empty_buckets, | |
1cf41dd7 | 1122 | }; |
33dc9b12 | 1123 | #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash) |
493762fc | 1124 | |
2b499381 | 1125 | static struct ftrace_ops global_ops = { |
33b7f99c SRRH |
1126 | .func = ftrace_stub, |
1127 | .local_hash.notrace_hash = EMPTY_HASH, | |
1128 | .local_hash.filter_hash = EMPTY_HASH, | |
1129 | INIT_OPS_HASH(global_ops) | |
1130 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | | |
e3eea140 SRRH |
1131 | FTRACE_OPS_FL_INITIALIZED | |
1132 | FTRACE_OPS_FL_PID, | |
f45948e8 SR |
1133 | }; |
1134 | ||
aec0be2d SRRH |
1135 | /* |
1136 | * This is used by __kernel_text_address() to return true if the | |
0af26492 | 1137 | * address is on a dynamically allocated trampoline that would |
aec0be2d SRRH |
1138 | * not return true for either core_kernel_text() or |
1139 | * is_module_text_address(). | |
1140 | */ | |
1141 | bool is_ftrace_trampoline(unsigned long addr) | |
1142 | { | |
1143 | struct ftrace_ops *op; | |
1144 | bool ret = false; | |
1145 | ||
1146 | /* | |
1147 | * Some of the ops may be dynamically allocated, | |
1148 | * they are freed after a synchronize_sched(). | |
1149 | */ | |
1150 | preempt_disable_notrace(); | |
1151 | ||
1152 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1153 | /* | |
1154 | * This is to check for dynamically allocated trampolines. | |
1155 | * Trampolines that are in kernel text will have | |
1156 | * core_kernel_text() return true. | |
1157 | */ | |
1158 | if (op->trampoline && op->trampoline_size) | |
1159 | if (addr >= op->trampoline && | |
1160 | addr < op->trampoline + op->trampoline_size) { | |
1161 | ret = true; | |
1162 | goto out; | |
1163 | } | |
1164 | } while_for_each_ftrace_op(op); | |
1165 | ||
1166 | out: | |
1167 | preempt_enable_notrace(); | |
1168 | ||
1169 | return ret; | |
1170 | } | |
1171 | ||
493762fc SR |
1172 | struct ftrace_page { |
1173 | struct ftrace_page *next; | |
a7900875 | 1174 | struct dyn_ftrace *records; |
493762fc | 1175 | int index; |
a7900875 | 1176 | int size; |
493762fc SR |
1177 | }; |
1178 | ||
a7900875 SR |
1179 | #define ENTRY_SIZE sizeof(struct dyn_ftrace) |
1180 | #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE) | |
493762fc SR |
1181 | |
1182 | /* estimate from running different kernels */ | |
1183 | #define NR_TO_INIT 10000 | |
1184 | ||
1185 | static struct ftrace_page *ftrace_pages_start; | |
1186 | static struct ftrace_page *ftrace_pages; | |
1187 | ||
2b0cce0e SRV |
1188 | static __always_inline unsigned long |
1189 | ftrace_hash_key(struct ftrace_hash *hash, unsigned long ip) | |
1190 | { | |
1191 | if (hash->size_bits > 0) | |
1192 | return hash_long(ip, hash->size_bits); | |
1193 | ||
1194 | return 0; | |
1195 | } | |
1196 | ||
2b2c279c SRV |
1197 | /* Only use this function if ftrace_hash_empty() has already been tested */ |
1198 | static __always_inline struct ftrace_func_entry * | |
1199 | __ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
b448c4e3 SR |
1200 | { |
1201 | unsigned long key; | |
1202 | struct ftrace_func_entry *entry; | |
1203 | struct hlist_head *hhd; | |
b448c4e3 | 1204 | |
2b0cce0e | 1205 | key = ftrace_hash_key(hash, ip); |
b448c4e3 SR |
1206 | hhd = &hash->buckets[key]; |
1207 | ||
1bb539ca | 1208 | hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) { |
b448c4e3 SR |
1209 | if (entry->ip == ip) |
1210 | return entry; | |
1211 | } | |
1212 | return NULL; | |
1213 | } | |
1214 | ||
2b2c279c SRV |
1215 | /** |
1216 | * ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash | |
1217 | * @hash: The hash to look at | |
1218 | * @ip: The instruction pointer to test | |
1219 | * | |
1220 | * Search a given @hash to see if a given instruction pointer (@ip) | |
1221 | * exists in it. | |
1222 | * | |
1223 | * Returns the entry that holds the @ip if found. NULL otherwise. | |
1224 | */ | |
1225 | struct ftrace_func_entry * | |
1226 | ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
1227 | { | |
1228 | if (ftrace_hash_empty(hash)) | |
1229 | return NULL; | |
1230 | ||
1231 | return __ftrace_lookup_ip(hash, ip); | |
1232 | } | |
1233 | ||
33dc9b12 SR |
1234 | static void __add_hash_entry(struct ftrace_hash *hash, |
1235 | struct ftrace_func_entry *entry) | |
b448c4e3 | 1236 | { |
b448c4e3 SR |
1237 | struct hlist_head *hhd; |
1238 | unsigned long key; | |
1239 | ||
2b0cce0e | 1240 | key = ftrace_hash_key(hash, entry->ip); |
b448c4e3 SR |
1241 | hhd = &hash->buckets[key]; |
1242 | hlist_add_head(&entry->hlist, hhd); | |
1243 | hash->count++; | |
33dc9b12 SR |
1244 | } |
1245 | ||
1246 | static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip) | |
1247 | { | |
1248 | struct ftrace_func_entry *entry; | |
1249 | ||
1250 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1251 | if (!entry) | |
1252 | return -ENOMEM; | |
1253 | ||
1254 | entry->ip = ip; | |
1255 | __add_hash_entry(hash, entry); | |
b448c4e3 SR |
1256 | |
1257 | return 0; | |
1258 | } | |
1259 | ||
1260 | static void | |
33dc9b12 | 1261 | free_hash_entry(struct ftrace_hash *hash, |
b448c4e3 SR |
1262 | struct ftrace_func_entry *entry) |
1263 | { | |
1264 | hlist_del(&entry->hlist); | |
1265 | kfree(entry); | |
1266 | hash->count--; | |
1267 | } | |
1268 | ||
33dc9b12 SR |
1269 | static void |
1270 | remove_hash_entry(struct ftrace_hash *hash, | |
1271 | struct ftrace_func_entry *entry) | |
1272 | { | |
1273 | hlist_del(&entry->hlist); | |
1274 | hash->count--; | |
1275 | } | |
1276 | ||
b448c4e3 SR |
1277 | static void ftrace_hash_clear(struct ftrace_hash *hash) |
1278 | { | |
1279 | struct hlist_head *hhd; | |
b67bfe0d | 1280 | struct hlist_node *tn; |
b448c4e3 SR |
1281 | struct ftrace_func_entry *entry; |
1282 | int size = 1 << hash->size_bits; | |
1283 | int i; | |
1284 | ||
33dc9b12 SR |
1285 | if (!hash->count) |
1286 | return; | |
1287 | ||
b448c4e3 SR |
1288 | for (i = 0; i < size; i++) { |
1289 | hhd = &hash->buckets[i]; | |
b67bfe0d | 1290 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) |
33dc9b12 | 1291 | free_hash_entry(hash, entry); |
b448c4e3 SR |
1292 | } |
1293 | FTRACE_WARN_ON(hash->count); | |
1294 | } | |
1295 | ||
33dc9b12 SR |
1296 | static void free_ftrace_hash(struct ftrace_hash *hash) |
1297 | { | |
1298 | if (!hash || hash == EMPTY_HASH) | |
1299 | return; | |
1300 | ftrace_hash_clear(hash); | |
1301 | kfree(hash->buckets); | |
1302 | kfree(hash); | |
1303 | } | |
1304 | ||
07fd5515 SR |
1305 | static void __free_ftrace_hash_rcu(struct rcu_head *rcu) |
1306 | { | |
1307 | struct ftrace_hash *hash; | |
1308 | ||
1309 | hash = container_of(rcu, struct ftrace_hash, rcu); | |
1310 | free_ftrace_hash(hash); | |
1311 | } | |
1312 | ||
1313 | static void free_ftrace_hash_rcu(struct ftrace_hash *hash) | |
1314 | { | |
1315 | if (!hash || hash == EMPTY_HASH) | |
1316 | return; | |
1317 | call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu); | |
1318 | } | |
1319 | ||
5500fa51 JO |
1320 | void ftrace_free_filter(struct ftrace_ops *ops) |
1321 | { | |
f04f24fb | 1322 | ftrace_ops_init(ops); |
33b7f99c SRRH |
1323 | free_ftrace_hash(ops->func_hash->filter_hash); |
1324 | free_ftrace_hash(ops->func_hash->notrace_hash); | |
5500fa51 JO |
1325 | } |
1326 | ||
33dc9b12 SR |
1327 | static struct ftrace_hash *alloc_ftrace_hash(int size_bits) |
1328 | { | |
1329 | struct ftrace_hash *hash; | |
1330 | int size; | |
1331 | ||
1332 | hash = kzalloc(sizeof(*hash), GFP_KERNEL); | |
1333 | if (!hash) | |
1334 | return NULL; | |
1335 | ||
1336 | size = 1 << size_bits; | |
47b0edcb | 1337 | hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL); |
33dc9b12 SR |
1338 | |
1339 | if (!hash->buckets) { | |
1340 | kfree(hash); | |
1341 | return NULL; | |
1342 | } | |
1343 | ||
1344 | hash->size_bits = size_bits; | |
1345 | ||
1346 | return hash; | |
1347 | } | |
1348 | ||
1349 | static struct ftrace_hash * | |
1350 | alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) | |
1351 | { | |
1352 | struct ftrace_func_entry *entry; | |
1353 | struct ftrace_hash *new_hash; | |
33dc9b12 SR |
1354 | int size; |
1355 | int ret; | |
1356 | int i; | |
1357 | ||
1358 | new_hash = alloc_ftrace_hash(size_bits); | |
1359 | if (!new_hash) | |
1360 | return NULL; | |
1361 | ||
1362 | /* Empty hash? */ | |
06a51d93 | 1363 | if (ftrace_hash_empty(hash)) |
33dc9b12 SR |
1364 | return new_hash; |
1365 | ||
1366 | size = 1 << hash->size_bits; | |
1367 | for (i = 0; i < size; i++) { | |
b67bfe0d | 1368 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { |
33dc9b12 SR |
1369 | ret = add_hash_entry(new_hash, entry->ip); |
1370 | if (ret < 0) | |
1371 | goto free_hash; | |
1372 | } | |
1373 | } | |
1374 | ||
1375 | FTRACE_WARN_ON(new_hash->count != hash->count); | |
1376 | ||
1377 | return new_hash; | |
1378 | ||
1379 | free_hash: | |
1380 | free_ftrace_hash(new_hash); | |
1381 | return NULL; | |
1382 | } | |
1383 | ||
41fb61c2 | 1384 | static void |
84261912 | 1385 | ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash); |
41fb61c2 | 1386 | static void |
84261912 | 1387 | ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash); |
41fb61c2 | 1388 | |
f8b8be8a MH |
1389 | static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, |
1390 | struct ftrace_hash *new_hash); | |
1391 | ||
3e278c0d NK |
1392 | static struct ftrace_hash * |
1393 | __ftrace_hash_move(struct ftrace_hash *src) | |
33dc9b12 SR |
1394 | { |
1395 | struct ftrace_func_entry *entry; | |
b67bfe0d | 1396 | struct hlist_node *tn; |
33dc9b12 | 1397 | struct hlist_head *hhd; |
07fd5515 | 1398 | struct ftrace_hash *new_hash; |
33dc9b12 SR |
1399 | int size = src->count; |
1400 | int bits = 0; | |
1401 | int i; | |
1402 | ||
1403 | /* | |
3e278c0d | 1404 | * If the new source is empty, just return the empty_hash. |
33dc9b12 | 1405 | */ |
3e278c0d NK |
1406 | if (!src->count) |
1407 | return EMPTY_HASH; | |
33dc9b12 | 1408 | |
33dc9b12 SR |
1409 | /* |
1410 | * Make the hash size about 1/2 the # found | |
1411 | */ | |
1412 | for (size /= 2; size; size >>= 1) | |
1413 | bits++; | |
1414 | ||
1415 | /* Don't allocate too much */ | |
1416 | if (bits > FTRACE_HASH_MAX_BITS) | |
1417 | bits = FTRACE_HASH_MAX_BITS; | |
1418 | ||
07fd5515 SR |
1419 | new_hash = alloc_ftrace_hash(bits); |
1420 | if (!new_hash) | |
3e278c0d | 1421 | return NULL; |
33dc9b12 SR |
1422 | |
1423 | size = 1 << src->size_bits; | |
1424 | for (i = 0; i < size; i++) { | |
1425 | hhd = &src->buckets[i]; | |
b67bfe0d | 1426 | hlist_for_each_entry_safe(entry, tn, hhd, hlist) { |
33dc9b12 | 1427 | remove_hash_entry(src, entry); |
07fd5515 | 1428 | __add_hash_entry(new_hash, entry); |
33dc9b12 SR |
1429 | } |
1430 | } | |
1431 | ||
3e278c0d NK |
1432 | return new_hash; |
1433 | } | |
1434 | ||
1435 | static int | |
1436 | ftrace_hash_move(struct ftrace_ops *ops, int enable, | |
1437 | struct ftrace_hash **dst, struct ftrace_hash *src) | |
1438 | { | |
1439 | struct ftrace_hash *new_hash; | |
1440 | int ret; | |
1441 | ||
1442 | /* Reject setting notrace hash on IPMODIFY ftrace_ops */ | |
1443 | if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable) | |
1444 | return -EINVAL; | |
1445 | ||
1446 | new_hash = __ftrace_hash_move(src); | |
1447 | if (!new_hash) | |
1448 | return -ENOMEM; | |
1449 | ||
f8b8be8a MH |
1450 | /* Make sure this can be applied if it is IPMODIFY ftrace_ops */ |
1451 | if (enable) { | |
1452 | /* IPMODIFY should be updated only when filter_hash updating */ | |
1453 | ret = ftrace_hash_ipmodify_update(ops, new_hash); | |
1454 | if (ret < 0) { | |
1455 | free_ftrace_hash(new_hash); | |
1456 | return ret; | |
1457 | } | |
1458 | } | |
1459 | ||
5c27c775 MH |
1460 | /* |
1461 | * Remove the current set, update the hash and add | |
1462 | * them back. | |
1463 | */ | |
84261912 | 1464 | ftrace_hash_rec_disable_modify(ops, enable); |
5c27c775 | 1465 | |
07fd5515 | 1466 | rcu_assign_pointer(*dst, new_hash); |
07fd5515 | 1467 | |
84261912 | 1468 | ftrace_hash_rec_enable_modify(ops, enable); |
41fb61c2 | 1469 | |
5c27c775 | 1470 | return 0; |
33dc9b12 SR |
1471 | } |
1472 | ||
fef5aeee SRRH |
1473 | static bool hash_contains_ip(unsigned long ip, |
1474 | struct ftrace_ops_hash *hash) | |
1475 | { | |
1476 | /* | |
1477 | * The function record is a match if it exists in the filter | |
1478 | * hash and not in the notrace hash. Note, an emty hash is | |
1479 | * considered a match for the filter hash, but an empty | |
1480 | * notrace hash is considered not in the notrace hash. | |
1481 | */ | |
1482 | return (ftrace_hash_empty(hash->filter_hash) || | |
2b2c279c | 1483 | __ftrace_lookup_ip(hash->filter_hash, ip)) && |
fef5aeee | 1484 | (ftrace_hash_empty(hash->notrace_hash) || |
2b2c279c | 1485 | !__ftrace_lookup_ip(hash->notrace_hash, ip)); |
fef5aeee SRRH |
1486 | } |
1487 | ||
b848914c SR |
1488 | /* |
1489 | * Test the hashes for this ops to see if we want to call | |
1490 | * the ops->func or not. | |
1491 | * | |
1492 | * It's a match if the ip is in the ops->filter_hash or | |
1493 | * the filter_hash does not exist or is empty, | |
1494 | * AND | |
1495 | * the ip is not in the ops->notrace_hash. | |
cdbe61bf SR |
1496 | * |
1497 | * This needs to be called with preemption disabled as | |
1498 | * the hashes are freed with call_rcu_sched(). | |
b848914c SR |
1499 | */ |
1500 | static int | |
195a8afc | 1501 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
b848914c | 1502 | { |
fef5aeee | 1503 | struct ftrace_ops_hash hash; |
b848914c SR |
1504 | int ret; |
1505 | ||
195a8afc SRRH |
1506 | #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
1507 | /* | |
1508 | * There's a small race when adding ops that the ftrace handler | |
1509 | * that wants regs, may be called without them. We can not | |
1510 | * allow that handler to be called if regs is NULL. | |
1511 | */ | |
1512 | if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS)) | |
1513 | return 0; | |
1514 | #endif | |
1515 | ||
fef5aeee SRRH |
1516 | hash.filter_hash = rcu_dereference_raw_notrace(ops->func_hash->filter_hash); |
1517 | hash.notrace_hash = rcu_dereference_raw_notrace(ops->func_hash->notrace_hash); | |
b848914c | 1518 | |
fef5aeee | 1519 | if (hash_contains_ip(ip, &hash)) |
b848914c SR |
1520 | ret = 1; |
1521 | else | |
1522 | ret = 0; | |
b848914c SR |
1523 | |
1524 | return ret; | |
1525 | } | |
1526 | ||
493762fc SR |
1527 | /* |
1528 | * This is a double for. Do not use 'break' to break out of the loop, | |
1529 | * you must use a goto. | |
1530 | */ | |
1531 | #define do_for_each_ftrace_rec(pg, rec) \ | |
1532 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
1533 | int _____i; \ | |
1534 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
1535 | rec = &pg->records[_____i]; | |
1536 | ||
1537 | #define while_for_each_ftrace_rec() \ | |
1538 | } \ | |
1539 | } | |
1540 | ||
5855fead SR |
1541 | |
1542 | static int ftrace_cmp_recs(const void *a, const void *b) | |
1543 | { | |
a650e02a SR |
1544 | const struct dyn_ftrace *key = a; |
1545 | const struct dyn_ftrace *rec = b; | |
5855fead | 1546 | |
a650e02a | 1547 | if (key->flags < rec->ip) |
5855fead | 1548 | return -1; |
a650e02a SR |
1549 | if (key->ip >= rec->ip + MCOUNT_INSN_SIZE) |
1550 | return 1; | |
5855fead SR |
1551 | return 0; |
1552 | } | |
1553 | ||
04cf31a7 ME |
1554 | /** |
1555 | * ftrace_location_range - return the first address of a traced location | |
1556 | * if it touches the given ip range | |
1557 | * @start: start of range to search. | |
1558 | * @end: end of range to search (inclusive). @end points to the last byte | |
1559 | * to check. | |
1560 | * | |
1561 | * Returns rec->ip if the related ftrace location is a least partly within | |
1562 | * the given address range. That is, the first address of the instruction | |
1563 | * that is either a NOP or call to the function tracer. It checks the ftrace | |
1564 | * internal tables to determine if the address belongs or not. | |
1565 | */ | |
1566 | unsigned long ftrace_location_range(unsigned long start, unsigned long end) | |
c88fd863 SR |
1567 | { |
1568 | struct ftrace_page *pg; | |
1569 | struct dyn_ftrace *rec; | |
5855fead | 1570 | struct dyn_ftrace key; |
c88fd863 | 1571 | |
a650e02a SR |
1572 | key.ip = start; |
1573 | key.flags = end; /* overload flags, as it is unsigned long */ | |
5855fead SR |
1574 | |
1575 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
a650e02a SR |
1576 | if (end < pg->records[0].ip || |
1577 | start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) | |
9644302e | 1578 | continue; |
5855fead SR |
1579 | rec = bsearch(&key, pg->records, pg->index, |
1580 | sizeof(struct dyn_ftrace), | |
1581 | ftrace_cmp_recs); | |
1582 | if (rec) | |
f0cf973a | 1583 | return rec->ip; |
5855fead | 1584 | } |
c88fd863 SR |
1585 | |
1586 | return 0; | |
1587 | } | |
1588 | ||
a650e02a SR |
1589 | /** |
1590 | * ftrace_location - return true if the ip giving is a traced location | |
1591 | * @ip: the instruction pointer to check | |
1592 | * | |
f0cf973a | 1593 | * Returns rec->ip if @ip given is a pointer to a ftrace location. |
a650e02a SR |
1594 | * That is, the instruction that is either a NOP or call to |
1595 | * the function tracer. It checks the ftrace internal tables to | |
1596 | * determine if the address belongs or not. | |
1597 | */ | |
f0cf973a | 1598 | unsigned long ftrace_location(unsigned long ip) |
a650e02a SR |
1599 | { |
1600 | return ftrace_location_range(ip, ip); | |
1601 | } | |
1602 | ||
1603 | /** | |
1604 | * ftrace_text_reserved - return true if range contains an ftrace location | |
1605 | * @start: start of range to search | |
1606 | * @end: end of range to search (inclusive). @end points to the last byte to check. | |
1607 | * | |
1608 | * Returns 1 if @start and @end contains a ftrace location. | |
1609 | * That is, the instruction that is either a NOP or call to | |
1610 | * the function tracer. It checks the ftrace internal tables to | |
1611 | * determine if the address belongs or not. | |
1612 | */ | |
d88471cb | 1613 | int ftrace_text_reserved(const void *start, const void *end) |
a650e02a | 1614 | { |
f0cf973a SR |
1615 | unsigned long ret; |
1616 | ||
1617 | ret = ftrace_location_range((unsigned long)start, | |
1618 | (unsigned long)end); | |
1619 | ||
1620 | return (int)!!ret; | |
a650e02a SR |
1621 | } |
1622 | ||
4fbb48cb SRRH |
1623 | /* Test if ops registered to this rec needs regs */ |
1624 | static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec) | |
1625 | { | |
1626 | struct ftrace_ops *ops; | |
1627 | bool keep_regs = false; | |
1628 | ||
1629 | for (ops = ftrace_ops_list; | |
1630 | ops != &ftrace_list_end; ops = ops->next) { | |
1631 | /* pass rec in as regs to have non-NULL val */ | |
1632 | if (ftrace_ops_test(ops, rec->ip, rec)) { | |
1633 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1634 | keep_regs = true; | |
1635 | break; | |
1636 | } | |
1637 | } | |
1638 | } | |
1639 | ||
1640 | return keep_regs; | |
1641 | } | |
1642 | ||
84b6d3e6 | 1643 | static bool __ftrace_hash_rec_update(struct ftrace_ops *ops, |
ed926f9b SR |
1644 | int filter_hash, |
1645 | bool inc) | |
1646 | { | |
1647 | struct ftrace_hash *hash; | |
1648 | struct ftrace_hash *other_hash; | |
1649 | struct ftrace_page *pg; | |
1650 | struct dyn_ftrace *rec; | |
84b6d3e6 | 1651 | bool update = false; |
ed926f9b SR |
1652 | int count = 0; |
1653 | int all = 0; | |
1654 | ||
1655 | /* Only update if the ops has been registered */ | |
1656 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
84b6d3e6 | 1657 | return false; |
ed926f9b SR |
1658 | |
1659 | /* | |
1660 | * In the filter_hash case: | |
1661 | * If the count is zero, we update all records. | |
1662 | * Otherwise we just update the items in the hash. | |
1663 | * | |
1664 | * In the notrace_hash case: | |
1665 | * We enable the update in the hash. | |
1666 | * As disabling notrace means enabling the tracing, | |
1667 | * and enabling notrace means disabling, the inc variable | |
1668 | * gets inversed. | |
1669 | */ | |
1670 | if (filter_hash) { | |
33b7f99c SRRH |
1671 | hash = ops->func_hash->filter_hash; |
1672 | other_hash = ops->func_hash->notrace_hash; | |
06a51d93 | 1673 | if (ftrace_hash_empty(hash)) |
ed926f9b SR |
1674 | all = 1; |
1675 | } else { | |
1676 | inc = !inc; | |
33b7f99c SRRH |
1677 | hash = ops->func_hash->notrace_hash; |
1678 | other_hash = ops->func_hash->filter_hash; | |
ed926f9b SR |
1679 | /* |
1680 | * If the notrace hash has no items, | |
1681 | * then there's nothing to do. | |
1682 | */ | |
06a51d93 | 1683 | if (ftrace_hash_empty(hash)) |
84b6d3e6 | 1684 | return false; |
ed926f9b SR |
1685 | } |
1686 | ||
1687 | do_for_each_ftrace_rec(pg, rec) { | |
1688 | int in_other_hash = 0; | |
1689 | int in_hash = 0; | |
1690 | int match = 0; | |
1691 | ||
b7ffffbb SRRH |
1692 | if (rec->flags & FTRACE_FL_DISABLED) |
1693 | continue; | |
1694 | ||
ed926f9b SR |
1695 | if (all) { |
1696 | /* | |
1697 | * Only the filter_hash affects all records. | |
1698 | * Update if the record is not in the notrace hash. | |
1699 | */ | |
b848914c | 1700 | if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) |
ed926f9b SR |
1701 | match = 1; |
1702 | } else { | |
06a51d93 SR |
1703 | in_hash = !!ftrace_lookup_ip(hash, rec->ip); |
1704 | in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip); | |
ed926f9b SR |
1705 | |
1706 | /* | |
19eab4a4 SRRH |
1707 | * If filter_hash is set, we want to match all functions |
1708 | * that are in the hash but not in the other hash. | |
ed926f9b | 1709 | * |
19eab4a4 SRRH |
1710 | * If filter_hash is not set, then we are decrementing. |
1711 | * That means we match anything that is in the hash | |
1712 | * and also in the other_hash. That is, we need to turn | |
1713 | * off functions in the other hash because they are disabled | |
1714 | * by this hash. | |
ed926f9b SR |
1715 | */ |
1716 | if (filter_hash && in_hash && !in_other_hash) | |
1717 | match = 1; | |
1718 | else if (!filter_hash && in_hash && | |
06a51d93 | 1719 | (in_other_hash || ftrace_hash_empty(other_hash))) |
ed926f9b SR |
1720 | match = 1; |
1721 | } | |
1722 | if (!match) | |
1723 | continue; | |
1724 | ||
1725 | if (inc) { | |
1726 | rec->flags++; | |
0376bde1 | 1727 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX)) |
84b6d3e6 | 1728 | return false; |
79922b80 SRRH |
1729 | |
1730 | /* | |
1731 | * If there's only a single callback registered to a | |
1732 | * function, and the ops has a trampoline registered | |
1733 | * for it, then we can call it directly. | |
1734 | */ | |
fef5aeee | 1735 | if (ftrace_rec_count(rec) == 1 && ops->trampoline) |
79922b80 | 1736 | rec->flags |= FTRACE_FL_TRAMP; |
fef5aeee | 1737 | else |
79922b80 SRRH |
1738 | /* |
1739 | * If we are adding another function callback | |
1740 | * to this function, and the previous had a | |
bce0b6c5 SRRH |
1741 | * custom trampoline in use, then we need to go |
1742 | * back to the default trampoline. | |
79922b80 | 1743 | */ |
fef5aeee | 1744 | rec->flags &= ~FTRACE_FL_TRAMP; |
79922b80 | 1745 | |
08f6fba5 SR |
1746 | /* |
1747 | * If any ops wants regs saved for this function | |
1748 | * then all ops will get saved regs. | |
1749 | */ | |
1750 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) | |
1751 | rec->flags |= FTRACE_FL_REGS; | |
ed926f9b | 1752 | } else { |
0376bde1 | 1753 | if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0)) |
84b6d3e6 | 1754 | return false; |
ed926f9b | 1755 | rec->flags--; |
79922b80 | 1756 | |
4fbb48cb SRRH |
1757 | /* |
1758 | * If the rec had REGS enabled and the ops that is | |
1759 | * being removed had REGS set, then see if there is | |
1760 | * still any ops for this record that wants regs. | |
1761 | * If not, we can stop recording them. | |
1762 | */ | |
0376bde1 | 1763 | if (ftrace_rec_count(rec) > 0 && |
4fbb48cb SRRH |
1764 | rec->flags & FTRACE_FL_REGS && |
1765 | ops->flags & FTRACE_OPS_FL_SAVE_REGS) { | |
1766 | if (!test_rec_ops_needs_regs(rec)) | |
1767 | rec->flags &= ~FTRACE_FL_REGS; | |
1768 | } | |
79922b80 | 1769 | |
fef5aeee SRRH |
1770 | /* |
1771 | * If the rec had TRAMP enabled, then it needs to | |
1772 | * be cleared. As TRAMP can only be enabled iff | |
1773 | * there is only a single ops attached to it. | |
1774 | * In otherwords, always disable it on decrementing. | |
1775 | * In the future, we may set it if rec count is | |
1776 | * decremented to one, and the ops that is left | |
1777 | * has a trampoline. | |
1778 | */ | |
1779 | rec->flags &= ~FTRACE_FL_TRAMP; | |
1780 | ||
79922b80 SRRH |
1781 | /* |
1782 | * flags will be cleared in ftrace_check_record() | |
1783 | * if rec count is zero. | |
1784 | */ | |
ed926f9b SR |
1785 | } |
1786 | count++; | |
84b6d3e6 JO |
1787 | |
1788 | /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */ | |
1789 | update |= ftrace_test_record(rec, 1) != FTRACE_UPDATE_IGNORE; | |
1790 | ||
ed926f9b SR |
1791 | /* Shortcut, if we handled all records, we are done. */ |
1792 | if (!all && count == hash->count) | |
84b6d3e6 | 1793 | return update; |
ed926f9b | 1794 | } while_for_each_ftrace_rec(); |
84b6d3e6 JO |
1795 | |
1796 | return update; | |
ed926f9b SR |
1797 | } |
1798 | ||
84b6d3e6 | 1799 | static bool ftrace_hash_rec_disable(struct ftrace_ops *ops, |
ed926f9b SR |
1800 | int filter_hash) |
1801 | { | |
84b6d3e6 | 1802 | return __ftrace_hash_rec_update(ops, filter_hash, 0); |
ed926f9b SR |
1803 | } |
1804 | ||
84b6d3e6 | 1805 | static bool ftrace_hash_rec_enable(struct ftrace_ops *ops, |
ed926f9b SR |
1806 | int filter_hash) |
1807 | { | |
84b6d3e6 | 1808 | return __ftrace_hash_rec_update(ops, filter_hash, 1); |
ed926f9b SR |
1809 | } |
1810 | ||
84261912 SRRH |
1811 | static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops, |
1812 | int filter_hash, int inc) | |
1813 | { | |
1814 | struct ftrace_ops *op; | |
1815 | ||
1816 | __ftrace_hash_rec_update(ops, filter_hash, inc); | |
1817 | ||
1818 | if (ops->func_hash != &global_ops.local_hash) | |
1819 | return; | |
1820 | ||
1821 | /* | |
1822 | * If the ops shares the global_ops hash, then we need to update | |
1823 | * all ops that are enabled and use this hash. | |
1824 | */ | |
1825 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
1826 | /* Already done */ | |
1827 | if (op == ops) | |
1828 | continue; | |
1829 | if (op->func_hash == &global_ops.local_hash) | |
1830 | __ftrace_hash_rec_update(op, filter_hash, inc); | |
1831 | } while_for_each_ftrace_op(op); | |
1832 | } | |
1833 | ||
1834 | static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, | |
1835 | int filter_hash) | |
1836 | { | |
1837 | ftrace_hash_rec_update_modify(ops, filter_hash, 0); | |
1838 | } | |
1839 | ||
1840 | static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, | |
1841 | int filter_hash) | |
1842 | { | |
1843 | ftrace_hash_rec_update_modify(ops, filter_hash, 1); | |
1844 | } | |
1845 | ||
f8b8be8a MH |
1846 | /* |
1847 | * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK | |
1848 | * or no-needed to update, -EBUSY if it detects a conflict of the flag | |
1849 | * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs. | |
1850 | * Note that old_hash and new_hash has below meanings | |
1851 | * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected) | |
1852 | * - If the hash is EMPTY_HASH, it hits nothing | |
1853 | * - Anything else hits the recs which match the hash entries. | |
1854 | */ | |
1855 | static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops, | |
1856 | struct ftrace_hash *old_hash, | |
1857 | struct ftrace_hash *new_hash) | |
1858 | { | |
1859 | struct ftrace_page *pg; | |
1860 | struct dyn_ftrace *rec, *end = NULL; | |
1861 | int in_old, in_new; | |
1862 | ||
1863 | /* Only update if the ops has been registered */ | |
1864 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
1865 | return 0; | |
1866 | ||
1867 | if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY)) | |
1868 | return 0; | |
1869 | ||
1870 | /* | |
1871 | * Since the IPMODIFY is a very address sensitive action, we do not | |
1872 | * allow ftrace_ops to set all functions to new hash. | |
1873 | */ | |
1874 | if (!new_hash || !old_hash) | |
1875 | return -EINVAL; | |
1876 | ||
1877 | /* Update rec->flags */ | |
1878 | do_for_each_ftrace_rec(pg, rec) { | |
546fece4 SRRH |
1879 | |
1880 | if (rec->flags & FTRACE_FL_DISABLED) | |
1881 | continue; | |
1882 | ||
f8b8be8a MH |
1883 | /* We need to update only differences of filter_hash */ |
1884 | in_old = !!ftrace_lookup_ip(old_hash, rec->ip); | |
1885 | in_new = !!ftrace_lookup_ip(new_hash, rec->ip); | |
1886 | if (in_old == in_new) | |
1887 | continue; | |
1888 | ||
1889 | if (in_new) { | |
1890 | /* New entries must ensure no others are using it */ | |
1891 | if (rec->flags & FTRACE_FL_IPMODIFY) | |
1892 | goto rollback; | |
1893 | rec->flags |= FTRACE_FL_IPMODIFY; | |
1894 | } else /* Removed entry */ | |
1895 | rec->flags &= ~FTRACE_FL_IPMODIFY; | |
1896 | } while_for_each_ftrace_rec(); | |
1897 | ||
1898 | return 0; | |
1899 | ||
1900 | rollback: | |
1901 | end = rec; | |
1902 | ||
1903 | /* Roll back what we did above */ | |
1904 | do_for_each_ftrace_rec(pg, rec) { | |
546fece4 SRRH |
1905 | |
1906 | if (rec->flags & FTRACE_FL_DISABLED) | |
1907 | continue; | |
1908 | ||
f8b8be8a MH |
1909 | if (rec == end) |
1910 | goto err_out; | |
1911 | ||
1912 | in_old = !!ftrace_lookup_ip(old_hash, rec->ip); | |
1913 | in_new = !!ftrace_lookup_ip(new_hash, rec->ip); | |
1914 | if (in_old == in_new) | |
1915 | continue; | |
1916 | ||
1917 | if (in_new) | |
1918 | rec->flags &= ~FTRACE_FL_IPMODIFY; | |
1919 | else | |
1920 | rec->flags |= FTRACE_FL_IPMODIFY; | |
1921 | } while_for_each_ftrace_rec(); | |
1922 | ||
1923 | err_out: | |
1924 | return -EBUSY; | |
1925 | } | |
1926 | ||
1927 | static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops) | |
1928 | { | |
1929 | struct ftrace_hash *hash = ops->func_hash->filter_hash; | |
1930 | ||
1931 | if (ftrace_hash_empty(hash)) | |
1932 | hash = NULL; | |
1933 | ||
1934 | return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash); | |
1935 | } | |
1936 | ||
1937 | /* Disabling always succeeds */ | |
1938 | static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops) | |
1939 | { | |
1940 | struct ftrace_hash *hash = ops->func_hash->filter_hash; | |
1941 | ||
1942 | if (ftrace_hash_empty(hash)) | |
1943 | hash = NULL; | |
1944 | ||
1945 | __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH); | |
1946 | } | |
1947 | ||
1948 | static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops, | |
1949 | struct ftrace_hash *new_hash) | |
1950 | { | |
1951 | struct ftrace_hash *old_hash = ops->func_hash->filter_hash; | |
1952 | ||
1953 | if (ftrace_hash_empty(old_hash)) | |
1954 | old_hash = NULL; | |
1955 | ||
1956 | if (ftrace_hash_empty(new_hash)) | |
1957 | new_hash = NULL; | |
1958 | ||
1959 | return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash); | |
1960 | } | |
1961 | ||
b05086c7 | 1962 | static void print_ip_ins(const char *fmt, const unsigned char *p) |
b17e8a37 SR |
1963 | { |
1964 | int i; | |
1965 | ||
1966 | printk(KERN_CONT "%s", fmt); | |
1967 | ||
1968 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
1969 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
1970 | } | |
1971 | ||
4fd3279b SRRH |
1972 | static struct ftrace_ops * |
1973 | ftrace_find_tramp_ops_any(struct dyn_ftrace *rec); | |
39daa7b9 SRRH |
1974 | static struct ftrace_ops * |
1975 | ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops); | |
4fd3279b | 1976 | |
02a392a0 | 1977 | enum ftrace_bug_type ftrace_bug_type; |
b05086c7 | 1978 | const void *ftrace_expected; |
02a392a0 SRRH |
1979 | |
1980 | static void print_bug_type(void) | |
1981 | { | |
1982 | switch (ftrace_bug_type) { | |
1983 | case FTRACE_BUG_UNKNOWN: | |
1984 | break; | |
1985 | case FTRACE_BUG_INIT: | |
1986 | pr_info("Initializing ftrace call sites\n"); | |
1987 | break; | |
1988 | case FTRACE_BUG_NOP: | |
1989 | pr_info("Setting ftrace call site to NOP\n"); | |
1990 | break; | |
1991 | case FTRACE_BUG_CALL: | |
1992 | pr_info("Setting ftrace call site to call ftrace function\n"); | |
1993 | break; | |
1994 | case FTRACE_BUG_UPDATE: | |
1995 | pr_info("Updating ftrace call site to call a different ftrace function\n"); | |
1996 | break; | |
1997 | } | |
1998 | } | |
1999 | ||
c88fd863 SR |
2000 | /** |
2001 | * ftrace_bug - report and shutdown function tracer | |
2002 | * @failed: The failed type (EFAULT, EINVAL, EPERM) | |
4fd3279b | 2003 | * @rec: The record that failed |
c88fd863 SR |
2004 | * |
2005 | * The arch code that enables or disables the function tracing | |
2006 | * can call ftrace_bug() when it has detected a problem in | |
2007 | * modifying the code. @failed should be one of either: | |
2008 | * EFAULT - if the problem happens on reading the @ip address | |
2009 | * EINVAL - if what is read at @ip is not what was expected | |
2010 | * EPERM - if the problem happens on writting to the @ip address | |
2011 | */ | |
4fd3279b | 2012 | void ftrace_bug(int failed, struct dyn_ftrace *rec) |
b17e8a37 | 2013 | { |
4fd3279b SRRH |
2014 | unsigned long ip = rec ? rec->ip : 0; |
2015 | ||
b17e8a37 SR |
2016 | switch (failed) { |
2017 | case -EFAULT: | |
2018 | FTRACE_WARN_ON_ONCE(1); | |
2019 | pr_info("ftrace faulted on modifying "); | |
2020 | print_ip_sym(ip); | |
2021 | break; | |
2022 | case -EINVAL: | |
2023 | FTRACE_WARN_ON_ONCE(1); | |
2024 | pr_info("ftrace failed to modify "); | |
2025 | print_ip_sym(ip); | |
b05086c7 | 2026 | print_ip_ins(" actual: ", (unsigned char *)ip); |
4fd3279b | 2027 | pr_cont("\n"); |
b05086c7 SRRH |
2028 | if (ftrace_expected) { |
2029 | print_ip_ins(" expected: ", ftrace_expected); | |
2030 | pr_cont("\n"); | |
2031 | } | |
b17e8a37 SR |
2032 | break; |
2033 | case -EPERM: | |
2034 | FTRACE_WARN_ON_ONCE(1); | |
2035 | pr_info("ftrace faulted on writing "); | |
2036 | print_ip_sym(ip); | |
2037 | break; | |
2038 | default: | |
2039 | FTRACE_WARN_ON_ONCE(1); | |
2040 | pr_info("ftrace faulted on unknown error "); | |
2041 | print_ip_sym(ip); | |
2042 | } | |
02a392a0 | 2043 | print_bug_type(); |
4fd3279b SRRH |
2044 | if (rec) { |
2045 | struct ftrace_ops *ops = NULL; | |
2046 | ||
2047 | pr_info("ftrace record flags: %lx\n", rec->flags); | |
2048 | pr_cont(" (%ld)%s", ftrace_rec_count(rec), | |
2049 | rec->flags & FTRACE_FL_REGS ? " R" : " "); | |
2050 | if (rec->flags & FTRACE_FL_TRAMP_EN) { | |
2051 | ops = ftrace_find_tramp_ops_any(rec); | |
39daa7b9 SRRH |
2052 | if (ops) { |
2053 | do { | |
2054 | pr_cont("\ttramp: %pS (%pS)", | |
2055 | (void *)ops->trampoline, | |
2056 | (void *)ops->func); | |
2057 | ops = ftrace_find_tramp_ops_next(rec, ops); | |
2058 | } while (ops); | |
2059 | } else | |
4fd3279b SRRH |
2060 | pr_cont("\ttramp: ERROR!"); |
2061 | ||
2062 | } | |
2063 | ip = ftrace_get_addr_curr(rec); | |
39daa7b9 | 2064 | pr_cont("\n expected tramp: %lx\n", ip); |
4fd3279b | 2065 | } |
b17e8a37 SR |
2066 | } |
2067 | ||
c88fd863 | 2068 | static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update) |
5072c59f | 2069 | { |
64fbcd16 | 2070 | unsigned long flag = 0UL; |
e7d3737e | 2071 | |
02a392a0 SRRH |
2072 | ftrace_bug_type = FTRACE_BUG_UNKNOWN; |
2073 | ||
b7ffffbb SRRH |
2074 | if (rec->flags & FTRACE_FL_DISABLED) |
2075 | return FTRACE_UPDATE_IGNORE; | |
2076 | ||
982c350b | 2077 | /* |
30fb6aa7 | 2078 | * If we are updating calls: |
982c350b | 2079 | * |
ed926f9b SR |
2080 | * If the record has a ref count, then we need to enable it |
2081 | * because someone is using it. | |
982c350b | 2082 | * |
ed926f9b SR |
2083 | * Otherwise we make sure its disabled. |
2084 | * | |
30fb6aa7 | 2085 | * If we are disabling calls, then disable all records that |
ed926f9b | 2086 | * are enabled. |
982c350b | 2087 | */ |
0376bde1 | 2088 | if (enable && ftrace_rec_count(rec)) |
ed926f9b | 2089 | flag = FTRACE_FL_ENABLED; |
982c350b | 2090 | |
08f6fba5 | 2091 | /* |
79922b80 SRRH |
2092 | * If enabling and the REGS flag does not match the REGS_EN, or |
2093 | * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore | |
2094 | * this record. Set flags to fail the compare against ENABLED. | |
08f6fba5 | 2095 | */ |
79922b80 SRRH |
2096 | if (flag) { |
2097 | if (!(rec->flags & FTRACE_FL_REGS) != | |
2098 | !(rec->flags & FTRACE_FL_REGS_EN)) | |
2099 | flag |= FTRACE_FL_REGS; | |
2100 | ||
2101 | if (!(rec->flags & FTRACE_FL_TRAMP) != | |
2102 | !(rec->flags & FTRACE_FL_TRAMP_EN)) | |
2103 | flag |= FTRACE_FL_TRAMP; | |
2104 | } | |
08f6fba5 | 2105 | |
64fbcd16 XG |
2106 | /* If the state of this record hasn't changed, then do nothing */ |
2107 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
c88fd863 | 2108 | return FTRACE_UPDATE_IGNORE; |
982c350b | 2109 | |
64fbcd16 | 2110 | if (flag) { |
08f6fba5 SR |
2111 | /* Save off if rec is being enabled (for return value) */ |
2112 | flag ^= rec->flags & FTRACE_FL_ENABLED; | |
2113 | ||
2114 | if (update) { | |
c88fd863 | 2115 | rec->flags |= FTRACE_FL_ENABLED; |
08f6fba5 SR |
2116 | if (flag & FTRACE_FL_REGS) { |
2117 | if (rec->flags & FTRACE_FL_REGS) | |
2118 | rec->flags |= FTRACE_FL_REGS_EN; | |
2119 | else | |
2120 | rec->flags &= ~FTRACE_FL_REGS_EN; | |
2121 | } | |
79922b80 SRRH |
2122 | if (flag & FTRACE_FL_TRAMP) { |
2123 | if (rec->flags & FTRACE_FL_TRAMP) | |
2124 | rec->flags |= FTRACE_FL_TRAMP_EN; | |
2125 | else | |
2126 | rec->flags &= ~FTRACE_FL_TRAMP_EN; | |
2127 | } | |
08f6fba5 SR |
2128 | } |
2129 | ||
2130 | /* | |
2131 | * If this record is being updated from a nop, then | |
2132 | * return UPDATE_MAKE_CALL. | |
08f6fba5 SR |
2133 | * Otherwise, |
2134 | * return UPDATE_MODIFY_CALL to tell the caller to convert | |
f1b2f2bd | 2135 | * from the save regs, to a non-save regs function or |
79922b80 | 2136 | * vice versa, or from a trampoline call. |
08f6fba5 | 2137 | */ |
02a392a0 SRRH |
2138 | if (flag & FTRACE_FL_ENABLED) { |
2139 | ftrace_bug_type = FTRACE_BUG_CALL; | |
08f6fba5 | 2140 | return FTRACE_UPDATE_MAKE_CALL; |
02a392a0 | 2141 | } |
f1b2f2bd | 2142 | |
02a392a0 | 2143 | ftrace_bug_type = FTRACE_BUG_UPDATE; |
f1b2f2bd | 2144 | return FTRACE_UPDATE_MODIFY_CALL; |
c88fd863 SR |
2145 | } |
2146 | ||
08f6fba5 SR |
2147 | if (update) { |
2148 | /* If there's no more users, clear all flags */ | |
0376bde1 | 2149 | if (!ftrace_rec_count(rec)) |
08f6fba5 SR |
2150 | rec->flags = 0; |
2151 | else | |
b24d443b SRRH |
2152 | /* |
2153 | * Just disable the record, but keep the ops TRAMP | |
2154 | * and REGS states. The _EN flags must be disabled though. | |
2155 | */ | |
2156 | rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN | | |
2157 | FTRACE_FL_REGS_EN); | |
08f6fba5 | 2158 | } |
c88fd863 | 2159 | |
02a392a0 | 2160 | ftrace_bug_type = FTRACE_BUG_NOP; |
c88fd863 SR |
2161 | return FTRACE_UPDATE_MAKE_NOP; |
2162 | } | |
2163 | ||
2164 | /** | |
2165 | * ftrace_update_record, set a record that now is tracing or not | |
2166 | * @rec: the record to update | |
2167 | * @enable: set to 1 if the record is tracing, zero to force disable | |
2168 | * | |
2169 | * The records that represent all functions that can be traced need | |
2170 | * to be updated when tracing has been enabled. | |
2171 | */ | |
2172 | int ftrace_update_record(struct dyn_ftrace *rec, int enable) | |
2173 | { | |
2174 | return ftrace_check_record(rec, enable, 1); | |
2175 | } | |
2176 | ||
2177 | /** | |
2178 | * ftrace_test_record, check if the record has been enabled or not | |
2179 | * @rec: the record to test | |
2180 | * @enable: set to 1 to check if enabled, 0 if it is disabled | |
2181 | * | |
2182 | * The arch code may need to test if a record is already set to | |
2183 | * tracing to determine how to modify the function code that it | |
2184 | * represents. | |
2185 | */ | |
2186 | int ftrace_test_record(struct dyn_ftrace *rec, int enable) | |
2187 | { | |
2188 | return ftrace_check_record(rec, enable, 0); | |
2189 | } | |
2190 | ||
5fecaa04 SRRH |
2191 | static struct ftrace_ops * |
2192 | ftrace_find_tramp_ops_any(struct dyn_ftrace *rec) | |
2193 | { | |
2194 | struct ftrace_ops *op; | |
fef5aeee | 2195 | unsigned long ip = rec->ip; |
5fecaa04 SRRH |
2196 | |
2197 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2198 | ||
2199 | if (!op->trampoline) | |
2200 | continue; | |
2201 | ||
fef5aeee | 2202 | if (hash_contains_ip(ip, op->func_hash)) |
5fecaa04 SRRH |
2203 | return op; |
2204 | } while_for_each_ftrace_op(op); | |
2205 | ||
2206 | return NULL; | |
2207 | } | |
2208 | ||
39daa7b9 SRRH |
2209 | static struct ftrace_ops * |
2210 | ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, | |
2211 | struct ftrace_ops *op) | |
2212 | { | |
2213 | unsigned long ip = rec->ip; | |
2214 | ||
2215 | while_for_each_ftrace_op(op) { | |
2216 | ||
2217 | if (!op->trampoline) | |
2218 | continue; | |
2219 | ||
2220 | if (hash_contains_ip(ip, op->func_hash)) | |
2221 | return op; | |
2222 | } | |
2223 | ||
2224 | return NULL; | |
2225 | } | |
2226 | ||
79922b80 SRRH |
2227 | static struct ftrace_ops * |
2228 | ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec) | |
2229 | { | |
2230 | struct ftrace_ops *op; | |
fef5aeee | 2231 | unsigned long ip = rec->ip; |
79922b80 | 2232 | |
fef5aeee SRRH |
2233 | /* |
2234 | * Need to check removed ops first. | |
2235 | * If they are being removed, and this rec has a tramp, | |
2236 | * and this rec is in the ops list, then it would be the | |
2237 | * one with the tramp. | |
2238 | */ | |
2239 | if (removed_ops) { | |
2240 | if (hash_contains_ip(ip, &removed_ops->old_hash)) | |
79922b80 SRRH |
2241 | return removed_ops; |
2242 | } | |
2243 | ||
fef5aeee SRRH |
2244 | /* |
2245 | * Need to find the current trampoline for a rec. | |
2246 | * Now, a trampoline is only attached to a rec if there | |
2247 | * was a single 'ops' attached to it. But this can be called | |
2248 | * when we are adding another op to the rec or removing the | |
2249 | * current one. Thus, if the op is being added, we can | |
2250 | * ignore it because it hasn't attached itself to the rec | |
4fc40904 SRRH |
2251 | * yet. |
2252 | * | |
2253 | * If an ops is being modified (hooking to different functions) | |
2254 | * then we don't care about the new functions that are being | |
2255 | * added, just the old ones (that are probably being removed). | |
2256 | * | |
2257 | * If we are adding an ops to a function that already is using | |
2258 | * a trampoline, it needs to be removed (trampolines are only | |
2259 | * for single ops connected), then an ops that is not being | |
2260 | * modified also needs to be checked. | |
fef5aeee | 2261 | */ |
79922b80 | 2262 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
fef5aeee SRRH |
2263 | |
2264 | if (!op->trampoline) | |
2265 | continue; | |
2266 | ||
2267 | /* | |
2268 | * If the ops is being added, it hasn't gotten to | |
2269 | * the point to be removed from this tree yet. | |
2270 | */ | |
2271 | if (op->flags & FTRACE_OPS_FL_ADDING) | |
79922b80 SRRH |
2272 | continue; |
2273 | ||
4fc40904 | 2274 | |
fef5aeee | 2275 | /* |
4fc40904 SRRH |
2276 | * If the ops is being modified and is in the old |
2277 | * hash, then it is probably being removed from this | |
2278 | * function. | |
fef5aeee | 2279 | */ |
fef5aeee SRRH |
2280 | if ((op->flags & FTRACE_OPS_FL_MODIFYING) && |
2281 | hash_contains_ip(ip, &op->old_hash)) | |
79922b80 | 2282 | return op; |
4fc40904 SRRH |
2283 | /* |
2284 | * If the ops is not being added or modified, and it's | |
2285 | * in its normal filter hash, then this must be the one | |
2286 | * we want! | |
2287 | */ | |
2288 | if (!(op->flags & FTRACE_OPS_FL_MODIFYING) && | |
2289 | hash_contains_ip(ip, op->func_hash)) | |
2290 | return op; | |
79922b80 SRRH |
2291 | |
2292 | } while_for_each_ftrace_op(op); | |
2293 | ||
2294 | return NULL; | |
2295 | } | |
2296 | ||
2297 | static struct ftrace_ops * | |
2298 | ftrace_find_tramp_ops_new(struct dyn_ftrace *rec) | |
2299 | { | |
2300 | struct ftrace_ops *op; | |
fef5aeee | 2301 | unsigned long ip = rec->ip; |
79922b80 SRRH |
2302 | |
2303 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
2304 | /* pass rec in as regs to have non-NULL val */ | |
fef5aeee | 2305 | if (hash_contains_ip(ip, op->func_hash)) |
79922b80 SRRH |
2306 | return op; |
2307 | } while_for_each_ftrace_op(op); | |
2308 | ||
2309 | return NULL; | |
2310 | } | |
2311 | ||
7413af1f SRRH |
2312 | /** |
2313 | * ftrace_get_addr_new - Get the call address to set to | |
2314 | * @rec: The ftrace record descriptor | |
2315 | * | |
2316 | * If the record has the FTRACE_FL_REGS set, that means that it | |
2317 | * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS | |
2318 | * is not not set, then it wants to convert to the normal callback. | |
2319 | * | |
2320 | * Returns the address of the trampoline to set to | |
2321 | */ | |
2322 | unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec) | |
2323 | { | |
79922b80 SRRH |
2324 | struct ftrace_ops *ops; |
2325 | ||
2326 | /* Trampolines take precedence over regs */ | |
2327 | if (rec->flags & FTRACE_FL_TRAMP) { | |
2328 | ops = ftrace_find_tramp_ops_new(rec); | |
2329 | if (FTRACE_WARN_ON(!ops || !ops->trampoline)) { | |
bce0b6c5 SRRH |
2330 | pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n", |
2331 | (void *)rec->ip, (void *)rec->ip, rec->flags); | |
79922b80 SRRH |
2332 | /* Ftrace is shutting down, return anything */ |
2333 | return (unsigned long)FTRACE_ADDR; | |
2334 | } | |
2335 | return ops->trampoline; | |
2336 | } | |
2337 | ||
7413af1f SRRH |
2338 | if (rec->flags & FTRACE_FL_REGS) |
2339 | return (unsigned long)FTRACE_REGS_ADDR; | |
2340 | else | |
2341 | return (unsigned long)FTRACE_ADDR; | |
2342 | } | |
2343 | ||
2344 | /** | |
2345 | * ftrace_get_addr_curr - Get the call address that is already there | |
2346 | * @rec: The ftrace record descriptor | |
2347 | * | |
2348 | * The FTRACE_FL_REGS_EN is set when the record already points to | |
2349 | * a function that saves all the regs. Basically the '_EN' version | |
2350 | * represents the current state of the function. | |
2351 | * | |
2352 | * Returns the address of the trampoline that is currently being called | |
2353 | */ | |
2354 | unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec) | |
2355 | { | |
79922b80 SRRH |
2356 | struct ftrace_ops *ops; |
2357 | ||
2358 | /* Trampolines take precedence over regs */ | |
2359 | if (rec->flags & FTRACE_FL_TRAMP_EN) { | |
2360 | ops = ftrace_find_tramp_ops_curr(rec); | |
2361 | if (FTRACE_WARN_ON(!ops)) { | |
a395d6a7 JP |
2362 | pr_warn("Bad trampoline accounting at: %p (%pS)\n", |
2363 | (void *)rec->ip, (void *)rec->ip); | |
79922b80 SRRH |
2364 | /* Ftrace is shutting down, return anything */ |
2365 | return (unsigned long)FTRACE_ADDR; | |
2366 | } | |
2367 | return ops->trampoline; | |
2368 | } | |
2369 | ||
7413af1f SRRH |
2370 | if (rec->flags & FTRACE_FL_REGS_EN) |
2371 | return (unsigned long)FTRACE_REGS_ADDR; | |
2372 | else | |
2373 | return (unsigned long)FTRACE_ADDR; | |
2374 | } | |
2375 | ||
c88fd863 SR |
2376 | static int |
2377 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) | |
2378 | { | |
08f6fba5 | 2379 | unsigned long ftrace_old_addr; |
c88fd863 SR |
2380 | unsigned long ftrace_addr; |
2381 | int ret; | |
2382 | ||
7c0868e0 | 2383 | ftrace_addr = ftrace_get_addr_new(rec); |
c88fd863 | 2384 | |
7c0868e0 SRRH |
2385 | /* This needs to be done before we call ftrace_update_record */ |
2386 | ftrace_old_addr = ftrace_get_addr_curr(rec); | |
2387 | ||
2388 | ret = ftrace_update_record(rec, enable); | |
08f6fba5 | 2389 | |
02a392a0 SRRH |
2390 | ftrace_bug_type = FTRACE_BUG_UNKNOWN; |
2391 | ||
c88fd863 SR |
2392 | switch (ret) { |
2393 | case FTRACE_UPDATE_IGNORE: | |
2394 | return 0; | |
2395 | ||
2396 | case FTRACE_UPDATE_MAKE_CALL: | |
02a392a0 | 2397 | ftrace_bug_type = FTRACE_BUG_CALL; |
64fbcd16 | 2398 | return ftrace_make_call(rec, ftrace_addr); |
c88fd863 SR |
2399 | |
2400 | case FTRACE_UPDATE_MAKE_NOP: | |
02a392a0 | 2401 | ftrace_bug_type = FTRACE_BUG_NOP; |
39b5552c | 2402 | return ftrace_make_nop(NULL, rec, ftrace_old_addr); |
08f6fba5 | 2403 | |
08f6fba5 | 2404 | case FTRACE_UPDATE_MODIFY_CALL: |
02a392a0 | 2405 | ftrace_bug_type = FTRACE_BUG_UPDATE; |
08f6fba5 | 2406 | return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr); |
5072c59f SR |
2407 | } |
2408 | ||
c88fd863 | 2409 | return -1; /* unknow ftrace bug */ |
5072c59f SR |
2410 | } |
2411 | ||
e4f5d544 | 2412 | void __weak ftrace_replace_code(int enable) |
3c1720f0 | 2413 | { |
3c1720f0 SR |
2414 | struct dyn_ftrace *rec; |
2415 | struct ftrace_page *pg; | |
6a24a244 | 2416 | int failed; |
3c1720f0 | 2417 | |
45a4a237 SR |
2418 | if (unlikely(ftrace_disabled)) |
2419 | return; | |
2420 | ||
265c831c | 2421 | do_for_each_ftrace_rec(pg, rec) { |
546fece4 SRRH |
2422 | |
2423 | if (rec->flags & FTRACE_FL_DISABLED) | |
2424 | continue; | |
2425 | ||
e4f5d544 | 2426 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 2427 | if (failed) { |
4fd3279b | 2428 | ftrace_bug(failed, rec); |
3279ba37 SR |
2429 | /* Stop processing */ |
2430 | return; | |
3c1720f0 | 2431 | } |
265c831c | 2432 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
2433 | } |
2434 | ||
c88fd863 SR |
2435 | struct ftrace_rec_iter { |
2436 | struct ftrace_page *pg; | |
2437 | int index; | |
2438 | }; | |
2439 | ||
2440 | /** | |
2441 | * ftrace_rec_iter_start, start up iterating over traced functions | |
2442 | * | |
2443 | * Returns an iterator handle that is used to iterate over all | |
2444 | * the records that represent address locations where functions | |
2445 | * are traced. | |
2446 | * | |
2447 | * May return NULL if no records are available. | |
2448 | */ | |
2449 | struct ftrace_rec_iter *ftrace_rec_iter_start(void) | |
2450 | { | |
2451 | /* | |
2452 | * We only use a single iterator. | |
2453 | * Protected by the ftrace_lock mutex. | |
2454 | */ | |
2455 | static struct ftrace_rec_iter ftrace_rec_iter; | |
2456 | struct ftrace_rec_iter *iter = &ftrace_rec_iter; | |
2457 | ||
2458 | iter->pg = ftrace_pages_start; | |
2459 | iter->index = 0; | |
2460 | ||
2461 | /* Could have empty pages */ | |
2462 | while (iter->pg && !iter->pg->index) | |
2463 | iter->pg = iter->pg->next; | |
2464 | ||
2465 | if (!iter->pg) | |
2466 | return NULL; | |
2467 | ||
2468 | return iter; | |
2469 | } | |
2470 | ||
2471 | /** | |
2472 | * ftrace_rec_iter_next, get the next record to process. | |
2473 | * @iter: The handle to the iterator. | |
2474 | * | |
2475 | * Returns the next iterator after the given iterator @iter. | |
2476 | */ | |
2477 | struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) | |
2478 | { | |
2479 | iter->index++; | |
2480 | ||
2481 | if (iter->index >= iter->pg->index) { | |
2482 | iter->pg = iter->pg->next; | |
2483 | iter->index = 0; | |
2484 | ||
2485 | /* Could have empty pages */ | |
2486 | while (iter->pg && !iter->pg->index) | |
2487 | iter->pg = iter->pg->next; | |
2488 | } | |
2489 | ||
2490 | if (!iter->pg) | |
2491 | return NULL; | |
2492 | ||
2493 | return iter; | |
2494 | } | |
2495 | ||
2496 | /** | |
2497 | * ftrace_rec_iter_record, get the record at the iterator location | |
2498 | * @iter: The current iterator location | |
2499 | * | |
2500 | * Returns the record that the current @iter is at. | |
2501 | */ | |
2502 | struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) | |
2503 | { | |
2504 | return &iter->pg->records[iter->index]; | |
2505 | } | |
2506 | ||
492a7ea5 | 2507 | static int |
31e88909 | 2508 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 | 2509 | { |
593eb8a2 | 2510 | int ret; |
3c1720f0 | 2511 | |
45a4a237 SR |
2512 | if (unlikely(ftrace_disabled)) |
2513 | return 0; | |
2514 | ||
25aac9dc | 2515 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 2516 | if (ret) { |
02a392a0 | 2517 | ftrace_bug_type = FTRACE_BUG_INIT; |
4fd3279b | 2518 | ftrace_bug(ret, rec); |
492a7ea5 | 2519 | return 0; |
37ad5084 | 2520 | } |
492a7ea5 | 2521 | return 1; |
3c1720f0 SR |
2522 | } |
2523 | ||
000ab691 SR |
2524 | /* |
2525 | * archs can override this function if they must do something | |
2526 | * before the modifying code is performed. | |
2527 | */ | |
2528 | int __weak ftrace_arch_code_modify_prepare(void) | |
2529 | { | |
2530 | return 0; | |
2531 | } | |
2532 | ||
2533 | /* | |
2534 | * archs can override this function if they must do something | |
2535 | * after the modifying code is performed. | |
2536 | */ | |
2537 | int __weak ftrace_arch_code_modify_post_process(void) | |
2538 | { | |
2539 | return 0; | |
2540 | } | |
2541 | ||
8ed3e2cf | 2542 | void ftrace_modify_all_code(int command) |
3d083395 | 2543 | { |
59338f75 | 2544 | int update = command & FTRACE_UPDATE_TRACE_FUNC; |
cd21067f | 2545 | int err = 0; |
59338f75 SRRH |
2546 | |
2547 | /* | |
2548 | * If the ftrace_caller calls a ftrace_ops func directly, | |
2549 | * we need to make sure that it only traces functions it | |
2550 | * expects to trace. When doing the switch of functions, | |
2551 | * we need to update to the ftrace_ops_list_func first | |
2552 | * before the transition between old and new calls are set, | |
2553 | * as the ftrace_ops_list_func will check the ops hashes | |
2554 | * to make sure the ops are having the right functions | |
2555 | * traced. | |
2556 | */ | |
cd21067f PM |
2557 | if (update) { |
2558 | err = ftrace_update_ftrace_func(ftrace_ops_list_func); | |
2559 | if (FTRACE_WARN_ON(err)) | |
2560 | return; | |
2561 | } | |
59338f75 | 2562 | |
8ed3e2cf | 2563 | if (command & FTRACE_UPDATE_CALLS) |
d61f82d0 | 2564 | ftrace_replace_code(1); |
8ed3e2cf | 2565 | else if (command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
2566 | ftrace_replace_code(0); |
2567 | ||
405e1d83 SRRH |
2568 | if (update && ftrace_trace_function != ftrace_ops_list_func) { |
2569 | function_trace_op = set_function_trace_op; | |
2570 | smp_wmb(); | |
2571 | /* If irqs are disabled, we are in stop machine */ | |
2572 | if (!irqs_disabled()) | |
2573 | smp_call_function(ftrace_sync_ipi, NULL, 1); | |
cd21067f PM |
2574 | err = ftrace_update_ftrace_func(ftrace_trace_function); |
2575 | if (FTRACE_WARN_ON(err)) | |
2576 | return; | |
405e1d83 | 2577 | } |
d61f82d0 | 2578 | |
8ed3e2cf | 2579 | if (command & FTRACE_START_FUNC_RET) |
cd21067f | 2580 | err = ftrace_enable_ftrace_graph_caller(); |
8ed3e2cf | 2581 | else if (command & FTRACE_STOP_FUNC_RET) |
cd21067f PM |
2582 | err = ftrace_disable_ftrace_graph_caller(); |
2583 | FTRACE_WARN_ON(err); | |
8ed3e2cf SR |
2584 | } |
2585 | ||
2586 | static int __ftrace_modify_code(void *data) | |
2587 | { | |
2588 | int *command = data; | |
2589 | ||
2590 | ftrace_modify_all_code(*command); | |
5a45cfe1 | 2591 | |
d61f82d0 | 2592 | return 0; |
3d083395 SR |
2593 | } |
2594 | ||
c88fd863 SR |
2595 | /** |
2596 | * ftrace_run_stop_machine, go back to the stop machine method | |
2597 | * @command: The command to tell ftrace what to do | |
2598 | * | |
2599 | * If an arch needs to fall back to the stop machine method, the | |
2600 | * it can call this function. | |
2601 | */ | |
2602 | void ftrace_run_stop_machine(int command) | |
2603 | { | |
2604 | stop_machine(__ftrace_modify_code, &command, NULL); | |
2605 | } | |
2606 | ||
2607 | /** | |
2608 | * arch_ftrace_update_code, modify the code to trace or not trace | |
2609 | * @command: The command that needs to be done | |
2610 | * | |
2611 | * Archs can override this function if it does not need to | |
2612 | * run stop_machine() to modify code. | |
2613 | */ | |
2614 | void __weak arch_ftrace_update_code(int command) | |
2615 | { | |
2616 | ftrace_run_stop_machine(command); | |
2617 | } | |
2618 | ||
e309b41d | 2619 | static void ftrace_run_update_code(int command) |
3d083395 | 2620 | { |
000ab691 SR |
2621 | int ret; |
2622 | ||
2623 | ret = ftrace_arch_code_modify_prepare(); | |
2624 | FTRACE_WARN_ON(ret); | |
2625 | if (ret) | |
2626 | return; | |
2627 | ||
c88fd863 SR |
2628 | /* |
2629 | * By default we use stop_machine() to modify the code. | |
2630 | * But archs can do what ever they want as long as it | |
2631 | * is safe. The stop_machine() is the safest, but also | |
2632 | * produces the most overhead. | |
2633 | */ | |
2634 | arch_ftrace_update_code(command); | |
2635 | ||
000ab691 SR |
2636 | ret = ftrace_arch_code_modify_post_process(); |
2637 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
2638 | } |
2639 | ||
8252ecf3 | 2640 | static void ftrace_run_modify_code(struct ftrace_ops *ops, int command, |
7485058e | 2641 | struct ftrace_ops_hash *old_hash) |
e1effa01 SRRH |
2642 | { |
2643 | ops->flags |= FTRACE_OPS_FL_MODIFYING; | |
7485058e SRRH |
2644 | ops->old_hash.filter_hash = old_hash->filter_hash; |
2645 | ops->old_hash.notrace_hash = old_hash->notrace_hash; | |
e1effa01 | 2646 | ftrace_run_update_code(command); |
8252ecf3 | 2647 | ops->old_hash.filter_hash = NULL; |
7485058e | 2648 | ops->old_hash.notrace_hash = NULL; |
e1effa01 SRRH |
2649 | ops->flags &= ~FTRACE_OPS_FL_MODIFYING; |
2650 | } | |
2651 | ||
d61f82d0 | 2652 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 2653 | static int ftrace_start_up; |
df4fc315 | 2654 | |
12cce594 SRRH |
2655 | void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops) |
2656 | { | |
2657 | } | |
2658 | ||
ba27f2bc | 2659 | static void per_cpu_ops_free(struct ftrace_ops *ops) |
db0fbadc JS |
2660 | { |
2661 | free_percpu(ops->disabled); | |
2662 | } | |
2663 | ||
df4fc315 SR |
2664 | static void ftrace_startup_enable(int command) |
2665 | { | |
2666 | if (saved_ftrace_func != ftrace_trace_function) { | |
2667 | saved_ftrace_func = ftrace_trace_function; | |
2668 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2669 | } | |
2670 | ||
2671 | if (!command || !ftrace_enabled) | |
2672 | return; | |
2673 | ||
2674 | ftrace_run_update_code(command); | |
2675 | } | |
d61f82d0 | 2676 | |
e1effa01 SRRH |
2677 | static void ftrace_startup_all(int command) |
2678 | { | |
2679 | update_all_ops = true; | |
2680 | ftrace_startup_enable(command); | |
2681 | update_all_ops = false; | |
2682 | } | |
2683 | ||
a1cd6173 | 2684 | static int ftrace_startup(struct ftrace_ops *ops, int command) |
3d083395 | 2685 | { |
8a56d776 | 2686 | int ret; |
b848914c | 2687 | |
4eebcc81 | 2688 | if (unlikely(ftrace_disabled)) |
a1cd6173 | 2689 | return -ENODEV; |
4eebcc81 | 2690 | |
8a56d776 SRRH |
2691 | ret = __register_ftrace_function(ops); |
2692 | if (ret) | |
2693 | return ret; | |
2694 | ||
60a7ecf4 | 2695 | ftrace_start_up++; |
d61f82d0 | 2696 | |
e1effa01 SRRH |
2697 | /* |
2698 | * Note that ftrace probes uses this to start up | |
2699 | * and modify functions it will probe. But we still | |
2700 | * set the ADDING flag for modification, as probes | |
2701 | * do not have trampolines. If they add them in the | |
2702 | * future, then the probes will need to distinguish | |
2703 | * between adding and updating probes. | |
2704 | */ | |
2705 | ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING; | |
66209a5b | 2706 | |
f8b8be8a MH |
2707 | ret = ftrace_hash_ipmodify_enable(ops); |
2708 | if (ret < 0) { | |
2709 | /* Rollback registration process */ | |
2710 | __unregister_ftrace_function(ops); | |
2711 | ftrace_start_up--; | |
2712 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; | |
2713 | return ret; | |
2714 | } | |
2715 | ||
7f50d06b JO |
2716 | if (ftrace_hash_rec_enable(ops, 1)) |
2717 | command |= FTRACE_UPDATE_CALLS; | |
ed926f9b | 2718 | |
df4fc315 | 2719 | ftrace_startup_enable(command); |
a1cd6173 | 2720 | |
e1effa01 SRRH |
2721 | ops->flags &= ~FTRACE_OPS_FL_ADDING; |
2722 | ||
a1cd6173 | 2723 | return 0; |
3d083395 SR |
2724 | } |
2725 | ||
8a56d776 | 2726 | static int ftrace_shutdown(struct ftrace_ops *ops, int command) |
3d083395 | 2727 | { |
8a56d776 | 2728 | int ret; |
b848914c | 2729 | |
4eebcc81 | 2730 | if (unlikely(ftrace_disabled)) |
8a56d776 SRRH |
2731 | return -ENODEV; |
2732 | ||
2733 | ret = __unregister_ftrace_function(ops); | |
2734 | if (ret) | |
2735 | return ret; | |
4eebcc81 | 2736 | |
60a7ecf4 | 2737 | ftrace_start_up--; |
9ea1a153 FW |
2738 | /* |
2739 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
2740 | * critical but the ftrace_call callers may be never nopped again after | |
2741 | * further ftrace uses. | |
2742 | */ | |
2743 | WARN_ON_ONCE(ftrace_start_up < 0); | |
2744 | ||
f8b8be8a MH |
2745 | /* Disabling ipmodify never fails */ |
2746 | ftrace_hash_ipmodify_disable(ops); | |
ed926f9b | 2747 | |
7f50d06b JO |
2748 | if (ftrace_hash_rec_disable(ops, 1)) |
2749 | command |= FTRACE_UPDATE_CALLS; | |
b848914c | 2750 | |
7f50d06b | 2751 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
3d083395 | 2752 | |
d61f82d0 SR |
2753 | if (saved_ftrace_func != ftrace_trace_function) { |
2754 | saved_ftrace_func = ftrace_trace_function; | |
2755 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2756 | } | |
3d083395 | 2757 | |
a4c35ed2 SRRH |
2758 | if (!command || !ftrace_enabled) { |
2759 | /* | |
ba27f2bc | 2760 | * If these are per_cpu ops, they still need their |
a4c35ed2 SRRH |
2761 | * per_cpu field freed. Since, function tracing is |
2762 | * not currently active, we can just free them | |
2763 | * without synchronizing all CPUs. | |
2764 | */ | |
ba27f2bc SRRH |
2765 | if (ops->flags & FTRACE_OPS_FL_PER_CPU) |
2766 | per_cpu_ops_free(ops); | |
8a56d776 | 2767 | return 0; |
a4c35ed2 | 2768 | } |
d61f82d0 | 2769 | |
79922b80 SRRH |
2770 | /* |
2771 | * If the ops uses a trampoline, then it needs to be | |
2772 | * tested first on update. | |
2773 | */ | |
e1effa01 | 2774 | ops->flags |= FTRACE_OPS_FL_REMOVING; |
79922b80 SRRH |
2775 | removed_ops = ops; |
2776 | ||
fef5aeee SRRH |
2777 | /* The trampoline logic checks the old hashes */ |
2778 | ops->old_hash.filter_hash = ops->func_hash->filter_hash; | |
2779 | ops->old_hash.notrace_hash = ops->func_hash->notrace_hash; | |
2780 | ||
d61f82d0 | 2781 | ftrace_run_update_code(command); |
a4c35ed2 | 2782 | |
84bde62c SRRH |
2783 | /* |
2784 | * If there's no more ops registered with ftrace, run a | |
2785 | * sanity check to make sure all rec flags are cleared. | |
2786 | */ | |
2787 | if (ftrace_ops_list == &ftrace_list_end) { | |
2788 | struct ftrace_page *pg; | |
2789 | struct dyn_ftrace *rec; | |
2790 | ||
2791 | do_for_each_ftrace_rec(pg, rec) { | |
977c1f9c | 2792 | if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_FL_DISABLED)) |
84bde62c SRRH |
2793 | pr_warn(" %pS flags:%lx\n", |
2794 | (void *)rec->ip, rec->flags); | |
2795 | } while_for_each_ftrace_rec(); | |
2796 | } | |
2797 | ||
fef5aeee SRRH |
2798 | ops->old_hash.filter_hash = NULL; |
2799 | ops->old_hash.notrace_hash = NULL; | |
2800 | ||
2801 | removed_ops = NULL; | |
e1effa01 | 2802 | ops->flags &= ~FTRACE_OPS_FL_REMOVING; |
79922b80 | 2803 | |
a4c35ed2 SRRH |
2804 | /* |
2805 | * Dynamic ops may be freed, we must make sure that all | |
2806 | * callers are done before leaving this function. | |
ba27f2bc | 2807 | * The same goes for freeing the per_cpu data of the per_cpu |
a4c35ed2 | 2808 | * ops. |
a4c35ed2 | 2809 | */ |
ba27f2bc | 2810 | if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_PER_CPU)) { |
0598e4f0 SRV |
2811 | /* |
2812 | * We need to do a hard force of sched synchronization. | |
2813 | * This is because we use preempt_disable() to do RCU, but | |
2814 | * the function tracers can be called where RCU is not watching | |
2815 | * (like before user_exit()). We can not rely on the RCU | |
2816 | * infrastructure to do the synchronization, thus we must do it | |
2817 | * ourselves. | |
2818 | */ | |
a4c35ed2 SRRH |
2819 | schedule_on_each_cpu(ftrace_sync); |
2820 | ||
0598e4f0 SRV |
2821 | /* |
2822 | * When the kernel is preeptive, tasks can be preempted | |
2823 | * while on a ftrace trampoline. Just scheduling a task on | |
2824 | * a CPU is not good enough to flush them. Calling | |
2825 | * synchornize_rcu_tasks() will wait for those tasks to | |
2826 | * execute and either schedule voluntarily or enter user space. | |
2827 | */ | |
2828 | if (IS_ENABLED(CONFIG_PREEMPT)) | |
2829 | synchronize_rcu_tasks(); | |
2830 | ||
12cce594 SRRH |
2831 | arch_ftrace_trampoline_free(ops); |
2832 | ||
ba27f2bc SRRH |
2833 | if (ops->flags & FTRACE_OPS_FL_PER_CPU) |
2834 | per_cpu_ops_free(ops); | |
a4c35ed2 SRRH |
2835 | } |
2836 | ||
8a56d776 | 2837 | return 0; |
3d083395 SR |
2838 | } |
2839 | ||
e309b41d | 2840 | static void ftrace_startup_sysctl(void) |
b0fc494f | 2841 | { |
1619dc3f PA |
2842 | int command; |
2843 | ||
4eebcc81 SR |
2844 | if (unlikely(ftrace_disabled)) |
2845 | return; | |
2846 | ||
d61f82d0 SR |
2847 | /* Force update next time */ |
2848 | saved_ftrace_func = NULL; | |
60a7ecf4 | 2849 | /* ftrace_start_up is true if we want ftrace running */ |
1619dc3f PA |
2850 | if (ftrace_start_up) { |
2851 | command = FTRACE_UPDATE_CALLS; | |
2852 | if (ftrace_graph_active) | |
2853 | command |= FTRACE_START_FUNC_RET; | |
524a3868 | 2854 | ftrace_startup_enable(command); |
1619dc3f | 2855 | } |
b0fc494f SR |
2856 | } |
2857 | ||
e309b41d | 2858 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 2859 | { |
1619dc3f PA |
2860 | int command; |
2861 | ||
4eebcc81 SR |
2862 | if (unlikely(ftrace_disabled)) |
2863 | return; | |
2864 | ||
60a7ecf4 | 2865 | /* ftrace_start_up is true if ftrace is running */ |
1619dc3f PA |
2866 | if (ftrace_start_up) { |
2867 | command = FTRACE_DISABLE_CALLS; | |
2868 | if (ftrace_graph_active) | |
2869 | command |= FTRACE_STOP_FUNC_RET; | |
2870 | ftrace_run_update_code(command); | |
2871 | } | |
b0fc494f SR |
2872 | } |
2873 | ||
a5a1d1c2 | 2874 | static u64 ftrace_update_time; |
3d083395 SR |
2875 | unsigned long ftrace_update_tot_cnt; |
2876 | ||
8c4f3c3f | 2877 | static inline int ops_traces_mod(struct ftrace_ops *ops) |
f7bc8b61 | 2878 | { |
8c4f3c3f SRRH |
2879 | /* |
2880 | * Filter_hash being empty will default to trace module. | |
2881 | * But notrace hash requires a test of individual module functions. | |
2882 | */ | |
33b7f99c SRRH |
2883 | return ftrace_hash_empty(ops->func_hash->filter_hash) && |
2884 | ftrace_hash_empty(ops->func_hash->notrace_hash); | |
8c4f3c3f SRRH |
2885 | } |
2886 | ||
2887 | /* | |
2888 | * Check if the current ops references the record. | |
2889 | * | |
2890 | * If the ops traces all functions, then it was already accounted for. | |
2891 | * If the ops does not trace the current record function, skip it. | |
2892 | * If the ops ignores the function via notrace filter, skip it. | |
2893 | */ | |
2894 | static inline bool | |
2895 | ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec) | |
2896 | { | |
2897 | /* If ops isn't enabled, ignore it */ | |
2898 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
2899 | return 0; | |
2900 | ||
b7ffffbb | 2901 | /* If ops traces all then it includes this function */ |
8c4f3c3f | 2902 | if (ops_traces_mod(ops)) |
b7ffffbb | 2903 | return 1; |
8c4f3c3f SRRH |
2904 | |
2905 | /* The function must be in the filter */ | |
33b7f99c | 2906 | if (!ftrace_hash_empty(ops->func_hash->filter_hash) && |
2b2c279c | 2907 | !__ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip)) |
8c4f3c3f | 2908 | return 0; |
f7bc8b61 | 2909 | |
8c4f3c3f | 2910 | /* If in notrace hash, we ignore it too */ |
33b7f99c | 2911 | if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip)) |
8c4f3c3f SRRH |
2912 | return 0; |
2913 | ||
2914 | return 1; | |
2915 | } | |
2916 | ||
1dc43cf0 | 2917 | static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs) |
3d083395 | 2918 | { |
85ae32ae | 2919 | struct ftrace_page *pg; |
e94142a6 | 2920 | struct dyn_ftrace *p; |
a5a1d1c2 | 2921 | u64 start, stop; |
1dc43cf0 | 2922 | unsigned long update_cnt = 0; |
b7ffffbb | 2923 | unsigned long rec_flags = 0; |
85ae32ae | 2924 | int i; |
f7bc8b61 | 2925 | |
b7ffffbb SRRH |
2926 | start = ftrace_now(raw_smp_processor_id()); |
2927 | ||
f7bc8b61 | 2928 | /* |
b7ffffbb SRRH |
2929 | * When a module is loaded, this function is called to convert |
2930 | * the calls to mcount in its text to nops, and also to create | |
2931 | * an entry in the ftrace data. Now, if ftrace is activated | |
2932 | * after this call, but before the module sets its text to | |
2933 | * read-only, the modification of enabling ftrace can fail if | |
2934 | * the read-only is done while ftrace is converting the calls. | |
2935 | * To prevent this, the module's records are set as disabled | |
2936 | * and will be enabled after the call to set the module's text | |
2937 | * to read-only. | |
f7bc8b61 | 2938 | */ |
b7ffffbb SRRH |
2939 | if (mod) |
2940 | rec_flags |= FTRACE_FL_DISABLED; | |
3d083395 | 2941 | |
1dc43cf0 | 2942 | for (pg = new_pgs; pg; pg = pg->next) { |
3d083395 | 2943 | |
85ae32ae | 2944 | for (i = 0; i < pg->index; i++) { |
8c4f3c3f | 2945 | |
85ae32ae SR |
2946 | /* If something went wrong, bail without enabling anything */ |
2947 | if (unlikely(ftrace_disabled)) | |
2948 | return -1; | |
f22f9a89 | 2949 | |
85ae32ae | 2950 | p = &pg->records[i]; |
b7ffffbb | 2951 | p->flags = rec_flags; |
f22f9a89 | 2952 | |
85ae32ae SR |
2953 | /* |
2954 | * Do the initial record conversion from mcount jump | |
2955 | * to the NOP instructions. | |
2956 | */ | |
2957 | if (!ftrace_code_disable(mod, p)) | |
2958 | break; | |
5cb084bb | 2959 | |
1dc43cf0 | 2960 | update_cnt++; |
5cb084bb | 2961 | } |
3d083395 SR |
2962 | } |
2963 | ||
750ed1a4 | 2964 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 | 2965 | ftrace_update_time = stop - start; |
1dc43cf0 | 2966 | ftrace_update_tot_cnt += update_cnt; |
3d083395 | 2967 | |
16444a8a ACM |
2968 | return 0; |
2969 | } | |
2970 | ||
a7900875 | 2971 | static int ftrace_allocate_records(struct ftrace_page *pg, int count) |
3c1720f0 | 2972 | { |
a7900875 | 2973 | int order; |
3c1720f0 | 2974 | int cnt; |
3c1720f0 | 2975 | |
a7900875 SR |
2976 | if (WARN_ON(!count)) |
2977 | return -EINVAL; | |
2978 | ||
2979 | order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE)); | |
3c1720f0 SR |
2980 | |
2981 | /* | |
a7900875 SR |
2982 | * We want to fill as much as possible. No more than a page |
2983 | * may be empty. | |
3c1720f0 | 2984 | */ |
a7900875 SR |
2985 | while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE) |
2986 | order--; | |
3c1720f0 | 2987 | |
a7900875 SR |
2988 | again: |
2989 | pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order); | |
3c1720f0 | 2990 | |
a7900875 SR |
2991 | if (!pg->records) { |
2992 | /* if we can't allocate this size, try something smaller */ | |
2993 | if (!order) | |
2994 | return -ENOMEM; | |
2995 | order >>= 1; | |
2996 | goto again; | |
2997 | } | |
3c1720f0 | 2998 | |
a7900875 SR |
2999 | cnt = (PAGE_SIZE << order) / ENTRY_SIZE; |
3000 | pg->size = cnt; | |
3c1720f0 | 3001 | |
a7900875 SR |
3002 | if (cnt > count) |
3003 | cnt = count; | |
3004 | ||
3005 | return cnt; | |
3006 | } | |
3007 | ||
3008 | static struct ftrace_page * | |
3009 | ftrace_allocate_pages(unsigned long num_to_init) | |
3010 | { | |
3011 | struct ftrace_page *start_pg; | |
3012 | struct ftrace_page *pg; | |
3013 | int order; | |
3014 | int cnt; | |
3015 | ||
3016 | if (!num_to_init) | |
3017 | return 0; | |
3018 | ||
3019 | start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL); | |
3020 | if (!pg) | |
3021 | return NULL; | |
3022 | ||
3023 | /* | |
3024 | * Try to allocate as much as possible in one continues | |
3025 | * location that fills in all of the space. We want to | |
3026 | * waste as little space as possible. | |
3027 | */ | |
3028 | for (;;) { | |
3029 | cnt = ftrace_allocate_records(pg, num_to_init); | |
3030 | if (cnt < 0) | |
3031 | goto free_pages; | |
3032 | ||
3033 | num_to_init -= cnt; | |
3034 | if (!num_to_init) | |
3c1720f0 SR |
3035 | break; |
3036 | ||
a7900875 SR |
3037 | pg->next = kzalloc(sizeof(*pg), GFP_KERNEL); |
3038 | if (!pg->next) | |
3039 | goto free_pages; | |
3040 | ||
3c1720f0 SR |
3041 | pg = pg->next; |
3042 | } | |
3043 | ||
a7900875 SR |
3044 | return start_pg; |
3045 | ||
3046 | free_pages: | |
1f61be00 NK |
3047 | pg = start_pg; |
3048 | while (pg) { | |
a7900875 SR |
3049 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
3050 | free_pages((unsigned long)pg->records, order); | |
3051 | start_pg = pg->next; | |
3052 | kfree(pg); | |
3053 | pg = start_pg; | |
3054 | } | |
3055 | pr_info("ftrace: FAILED to allocate memory for functions\n"); | |
3056 | return NULL; | |
3057 | } | |
3058 | ||
5072c59f SR |
3059 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ |
3060 | ||
3061 | struct ftrace_iterator { | |
98c4fd04 | 3062 | loff_t pos; |
4aeb6967 SR |
3063 | loff_t func_pos; |
3064 | struct ftrace_page *pg; | |
3065 | struct dyn_ftrace *func; | |
3066 | struct ftrace_func_probe *probe; | |
3067 | struct trace_parser parser; | |
1cf41dd7 | 3068 | struct ftrace_hash *hash; |
33dc9b12 | 3069 | struct ftrace_ops *ops; |
4aeb6967 SR |
3070 | int hidx; |
3071 | int idx; | |
3072 | unsigned flags; | |
5072c59f SR |
3073 | }; |
3074 | ||
8fc0c701 | 3075 | static void * |
4aeb6967 | 3076 | t_hash_next(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
3077 | { |
3078 | struct ftrace_iterator *iter = m->private; | |
4aeb6967 | 3079 | struct hlist_node *hnd = NULL; |
8fc0c701 SR |
3080 | struct hlist_head *hhd; |
3081 | ||
8fc0c701 | 3082 | (*pos)++; |
98c4fd04 | 3083 | iter->pos = *pos; |
8fc0c701 | 3084 | |
4aeb6967 SR |
3085 | if (iter->probe) |
3086 | hnd = &iter->probe->node; | |
8fc0c701 SR |
3087 | retry: |
3088 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
3089 | return NULL; | |
3090 | ||
3091 | hhd = &ftrace_func_hash[iter->hidx]; | |
3092 | ||
3093 | if (hlist_empty(hhd)) { | |
3094 | iter->hidx++; | |
3095 | hnd = NULL; | |
3096 | goto retry; | |
3097 | } | |
3098 | ||
3099 | if (!hnd) | |
3100 | hnd = hhd->first; | |
3101 | else { | |
3102 | hnd = hnd->next; | |
3103 | if (!hnd) { | |
3104 | iter->hidx++; | |
3105 | goto retry; | |
3106 | } | |
3107 | } | |
3108 | ||
4aeb6967 SR |
3109 | if (WARN_ON_ONCE(!hnd)) |
3110 | return NULL; | |
3111 | ||
3112 | iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node); | |
3113 | ||
3114 | return iter; | |
8fc0c701 SR |
3115 | } |
3116 | ||
3117 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
3118 | { | |
3119 | struct ftrace_iterator *iter = m->private; | |
3120 | void *p = NULL; | |
d82d6244 LZ |
3121 | loff_t l; |
3122 | ||
69a3083c SR |
3123 | if (!(iter->flags & FTRACE_ITER_DO_HASH)) |
3124 | return NULL; | |
3125 | ||
2bccfffd SR |
3126 | if (iter->func_pos > *pos) |
3127 | return NULL; | |
8fc0c701 | 3128 | |
d82d6244 | 3129 | iter->hidx = 0; |
2bccfffd | 3130 | for (l = 0; l <= (*pos - iter->func_pos); ) { |
4aeb6967 | 3131 | p = t_hash_next(m, &l); |
d82d6244 LZ |
3132 | if (!p) |
3133 | break; | |
3134 | } | |
4aeb6967 SR |
3135 | if (!p) |
3136 | return NULL; | |
3137 | ||
98c4fd04 SR |
3138 | /* Only set this if we have an item */ |
3139 | iter->flags |= FTRACE_ITER_HASH; | |
3140 | ||
4aeb6967 | 3141 | return iter; |
8fc0c701 SR |
3142 | } |
3143 | ||
4aeb6967 SR |
3144 | static int |
3145 | t_hash_show(struct seq_file *m, struct ftrace_iterator *iter) | |
8fc0c701 | 3146 | { |
b6887d79 | 3147 | struct ftrace_func_probe *rec; |
8fc0c701 | 3148 | |
4aeb6967 SR |
3149 | rec = iter->probe; |
3150 | if (WARN_ON_ONCE(!rec)) | |
3151 | return -EIO; | |
8fc0c701 | 3152 | |
809dcf29 | 3153 | if (rec->ops->print) |
1a48df00 | 3154 | return rec->ops->print(m, rec->ip, rec->ops, NULL); |
809dcf29 | 3155 | |
02b77e2a | 3156 | seq_printf(m, "%ps:%ps\n", (void *)rec->ip, (void *)rec->ops->func); |
8fc0c701 SR |
3157 | |
3158 | return 0; | |
3159 | } | |
3160 | ||
e309b41d | 3161 | static void * |
5bd84629 | 3162 | t_func_next(struct seq_file *m, loff_t *pos) |
5072c59f SR |
3163 | { |
3164 | struct ftrace_iterator *iter = m->private; | |
3165 | struct dyn_ftrace *rec = NULL; | |
3166 | ||
3167 | (*pos)++; | |
0c75a3ed | 3168 | |
5072c59f SR |
3169 | retry: |
3170 | if (iter->idx >= iter->pg->index) { | |
3171 | if (iter->pg->next) { | |
3172 | iter->pg = iter->pg->next; | |
3173 | iter->idx = 0; | |
3174 | goto retry; | |
3175 | } | |
3176 | } else { | |
3177 | rec = &iter->pg->records[iter->idx++]; | |
c20489da SRV |
3178 | if (((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) && |
3179 | !ftrace_lookup_ip(iter->hash, rec->ip)) || | |
647bcd03 SR |
3180 | |
3181 | ((iter->flags & FTRACE_ITER_ENABLED) && | |
23ea9c4d | 3182 | !(rec->flags & FTRACE_FL_ENABLED))) { |
647bcd03 | 3183 | |
5072c59f SR |
3184 | rec = NULL; |
3185 | goto retry; | |
3186 | } | |
3187 | } | |
3188 | ||
4aeb6967 | 3189 | if (!rec) |
5bd84629 | 3190 | return NULL; |
4aeb6967 | 3191 | |
5bd84629 | 3192 | iter->pos = iter->func_pos = *pos; |
4aeb6967 SR |
3193 | iter->func = rec; |
3194 | ||
3195 | return iter; | |
5072c59f SR |
3196 | } |
3197 | ||
5bd84629 SRV |
3198 | static void * |
3199 | t_next(struct seq_file *m, void *v, loff_t *pos) | |
3200 | { | |
3201 | struct ftrace_iterator *iter = m->private; | |
fcdc7125 | 3202 | loff_t l = *pos; /* t_hash_start() must use original pos */ |
5bd84629 SRV |
3203 | void *ret; |
3204 | ||
3205 | if (unlikely(ftrace_disabled)) | |
3206 | return NULL; | |
3207 | ||
3208 | if (iter->flags & FTRACE_ITER_HASH) | |
3209 | return t_hash_next(m, pos); | |
3210 | ||
3211 | if (iter->flags & FTRACE_ITER_PRINTALL) { | |
3212 | /* next must increment pos, and t_hash_start does not */ | |
3213 | (*pos)++; | |
fcdc7125 | 3214 | return t_hash_start(m, &l); |
5bd84629 SRV |
3215 | } |
3216 | ||
3217 | ret = t_func_next(m, pos); | |
3218 | ||
3219 | if (!ret) | |
fcdc7125 | 3220 | return t_hash_start(m, &l); |
5bd84629 SRV |
3221 | |
3222 | return ret; | |
3223 | } | |
3224 | ||
98c4fd04 SR |
3225 | static void reset_iter_read(struct ftrace_iterator *iter) |
3226 | { | |
3227 | iter->pos = 0; | |
3228 | iter->func_pos = 0; | |
70f77b3f | 3229 | iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_HASH); |
5072c59f SR |
3230 | } |
3231 | ||
3232 | static void *t_start(struct seq_file *m, loff_t *pos) | |
3233 | { | |
3234 | struct ftrace_iterator *iter = m->private; | |
3235 | void *p = NULL; | |
694ce0a5 | 3236 | loff_t l; |
5072c59f | 3237 | |
8fc0c701 | 3238 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
3239 | |
3240 | if (unlikely(ftrace_disabled)) | |
3241 | return NULL; | |
3242 | ||
98c4fd04 SR |
3243 | /* |
3244 | * If an lseek was done, then reset and start from beginning. | |
3245 | */ | |
3246 | if (*pos < iter->pos) | |
3247 | reset_iter_read(iter); | |
3248 | ||
0c75a3ed SR |
3249 | /* |
3250 | * For set_ftrace_filter reading, if we have the filter | |
3251 | * off, we can short cut and just print out that all | |
3252 | * functions are enabled. | |
3253 | */ | |
c20489da SRV |
3254 | if ((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) && |
3255 | ftrace_hash_empty(iter->hash)) { | |
43ff926a | 3256 | iter->func_pos = 1; /* Account for the message */ |
0c75a3ed | 3257 | if (*pos > 0) |
8fc0c701 | 3258 | return t_hash_start(m, pos); |
0c75a3ed | 3259 | iter->flags |= FTRACE_ITER_PRINTALL; |
df091625 CW |
3260 | /* reset in case of seek/pread */ |
3261 | iter->flags &= ~FTRACE_ITER_HASH; | |
0c75a3ed SR |
3262 | return iter; |
3263 | } | |
3264 | ||
8fc0c701 SR |
3265 | if (iter->flags & FTRACE_ITER_HASH) |
3266 | return t_hash_start(m, pos); | |
3267 | ||
98c4fd04 SR |
3268 | /* |
3269 | * Unfortunately, we need to restart at ftrace_pages_start | |
3270 | * every time we let go of the ftrace_mutex. This is because | |
3271 | * those pointers can change without the lock. | |
3272 | */ | |
694ce0a5 LZ |
3273 | iter->pg = ftrace_pages_start; |
3274 | iter->idx = 0; | |
3275 | for (l = 0; l <= *pos; ) { | |
5bd84629 | 3276 | p = t_func_next(m, &l); |
694ce0a5 LZ |
3277 | if (!p) |
3278 | break; | |
50cdaf08 | 3279 | } |
5821e1b7 | 3280 | |
69a3083c | 3281 | if (!p) |
5bd84629 | 3282 | return t_hash_start(m, pos); |
4aeb6967 SR |
3283 | |
3284 | return iter; | |
5072c59f SR |
3285 | } |
3286 | ||
3287 | static void t_stop(struct seq_file *m, void *p) | |
3288 | { | |
8fc0c701 | 3289 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
3290 | } |
3291 | ||
15d5b02c SRRH |
3292 | void * __weak |
3293 | arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec) | |
3294 | { | |
3295 | return NULL; | |
3296 | } | |
3297 | ||
3298 | static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops, | |
3299 | struct dyn_ftrace *rec) | |
3300 | { | |
3301 | void *ptr; | |
3302 | ||
3303 | ptr = arch_ftrace_trampoline_func(ops, rec); | |
3304 | if (ptr) | |
3305 | seq_printf(m, " ->%pS", ptr); | |
3306 | } | |
3307 | ||
5072c59f SR |
3308 | static int t_show(struct seq_file *m, void *v) |
3309 | { | |
0c75a3ed | 3310 | struct ftrace_iterator *iter = m->private; |
4aeb6967 | 3311 | struct dyn_ftrace *rec; |
5072c59f | 3312 | |
8fc0c701 | 3313 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 3314 | return t_hash_show(m, iter); |
8fc0c701 | 3315 | |
0c75a3ed | 3316 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
8c006cf7 | 3317 | if (iter->flags & FTRACE_ITER_NOTRACE) |
fa6f0cc7 | 3318 | seq_puts(m, "#### no functions disabled ####\n"); |
8c006cf7 | 3319 | else |
fa6f0cc7 | 3320 | seq_puts(m, "#### all functions enabled ####\n"); |
0c75a3ed SR |
3321 | return 0; |
3322 | } | |
3323 | ||
4aeb6967 SR |
3324 | rec = iter->func; |
3325 | ||
5072c59f SR |
3326 | if (!rec) |
3327 | return 0; | |
3328 | ||
647bcd03 | 3329 | seq_printf(m, "%ps", (void *)rec->ip); |
9674b2fa | 3330 | if (iter->flags & FTRACE_ITER_ENABLED) { |
030f4e1c | 3331 | struct ftrace_ops *ops; |
15d5b02c | 3332 | |
f8b8be8a | 3333 | seq_printf(m, " (%ld)%s%s", |
0376bde1 | 3334 | ftrace_rec_count(rec), |
f8b8be8a MH |
3335 | rec->flags & FTRACE_FL_REGS ? " R" : " ", |
3336 | rec->flags & FTRACE_FL_IPMODIFY ? " I" : " "); | |
9674b2fa | 3337 | if (rec->flags & FTRACE_FL_TRAMP_EN) { |
5fecaa04 | 3338 | ops = ftrace_find_tramp_ops_any(rec); |
39daa7b9 SRRH |
3339 | if (ops) { |
3340 | do { | |
3341 | seq_printf(m, "\ttramp: %pS (%pS)", | |
3342 | (void *)ops->trampoline, | |
3343 | (void *)ops->func); | |
030f4e1c | 3344 | add_trampoline_func(m, ops, rec); |
39daa7b9 SRRH |
3345 | ops = ftrace_find_tramp_ops_next(rec, ops); |
3346 | } while (ops); | |
3347 | } else | |
fa6f0cc7 | 3348 | seq_puts(m, "\ttramp: ERROR!"); |
030f4e1c SRRH |
3349 | } else { |
3350 | add_trampoline_func(m, NULL, rec); | |
9674b2fa SRRH |
3351 | } |
3352 | } | |
3353 | ||
fa6f0cc7 | 3354 | seq_putc(m, '\n'); |
5072c59f SR |
3355 | |
3356 | return 0; | |
3357 | } | |
3358 | ||
88e9d34c | 3359 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
3360 | .start = t_start, |
3361 | .next = t_next, | |
3362 | .stop = t_stop, | |
3363 | .show = t_show, | |
3364 | }; | |
3365 | ||
e309b41d | 3366 | static int |
5072c59f SR |
3367 | ftrace_avail_open(struct inode *inode, struct file *file) |
3368 | { | |
3369 | struct ftrace_iterator *iter; | |
5072c59f | 3370 | |
4eebcc81 SR |
3371 | if (unlikely(ftrace_disabled)) |
3372 | return -ENODEV; | |
3373 | ||
50e18b94 | 3374 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
c1bc5919 SRV |
3375 | if (!iter) |
3376 | return -ENOMEM; | |
5072c59f | 3377 | |
c1bc5919 SRV |
3378 | iter->pg = ftrace_pages_start; |
3379 | iter->ops = &global_ops; | |
3380 | ||
3381 | return 0; | |
5072c59f SR |
3382 | } |
3383 | ||
647bcd03 SR |
3384 | static int |
3385 | ftrace_enabled_open(struct inode *inode, struct file *file) | |
3386 | { | |
3387 | struct ftrace_iterator *iter; | |
647bcd03 | 3388 | |
50e18b94 | 3389 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
c1bc5919 SRV |
3390 | if (!iter) |
3391 | return -ENOMEM; | |
647bcd03 | 3392 | |
c1bc5919 SRV |
3393 | iter->pg = ftrace_pages_start; |
3394 | iter->flags = FTRACE_ITER_ENABLED; | |
3395 | iter->ops = &global_ops; | |
3396 | ||
3397 | return 0; | |
647bcd03 SR |
3398 | } |
3399 | ||
fc13cb0c SR |
3400 | /** |
3401 | * ftrace_regex_open - initialize function tracer filter files | |
3402 | * @ops: The ftrace_ops that hold the hash filters | |
3403 | * @flag: The type of filter to process | |
3404 | * @inode: The inode, usually passed in to your open routine | |
3405 | * @file: The file, usually passed in to your open routine | |
3406 | * | |
3407 | * ftrace_regex_open() initializes the filter files for the | |
3408 | * @ops. Depending on @flag it may process the filter hash or | |
3409 | * the notrace hash of @ops. With this called from the open | |
3410 | * routine, you can use ftrace_filter_write() for the write | |
3411 | * routine if @flag has FTRACE_ITER_FILTER set, or | |
3412 | * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set. | |
098c879e | 3413 | * tracing_lseek() should be used as the lseek routine, and |
fc13cb0c SR |
3414 | * release must call ftrace_regex_release(). |
3415 | */ | |
3416 | int | |
f45948e8 | 3417 | ftrace_regex_open(struct ftrace_ops *ops, int flag, |
1cf41dd7 | 3418 | struct inode *inode, struct file *file) |
5072c59f SR |
3419 | { |
3420 | struct ftrace_iterator *iter; | |
f45948e8 | 3421 | struct ftrace_hash *hash; |
5072c59f SR |
3422 | int ret = 0; |
3423 | ||
f04f24fb MH |
3424 | ftrace_ops_init(ops); |
3425 | ||
4eebcc81 SR |
3426 | if (unlikely(ftrace_disabled)) |
3427 | return -ENODEV; | |
3428 | ||
5072c59f SR |
3429 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
3430 | if (!iter) | |
3431 | return -ENOMEM; | |
3432 | ||
689fd8b6 | 3433 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) { |
3434 | kfree(iter); | |
3435 | return -ENOMEM; | |
3436 | } | |
3437 | ||
3f2367ba MH |
3438 | iter->ops = ops; |
3439 | iter->flags = flag; | |
3440 | ||
33b7f99c | 3441 | mutex_lock(&ops->func_hash->regex_lock); |
3f2367ba | 3442 | |
f45948e8 | 3443 | if (flag & FTRACE_ITER_NOTRACE) |
33b7f99c | 3444 | hash = ops->func_hash->notrace_hash; |
f45948e8 | 3445 | else |
33b7f99c | 3446 | hash = ops->func_hash->filter_hash; |
f45948e8 | 3447 | |
33dc9b12 | 3448 | if (file->f_mode & FMODE_WRITE) { |
ef2fbe16 NK |
3449 | const int size_bits = FTRACE_HASH_DEFAULT_BITS; |
3450 | ||
3451 | if (file->f_flags & O_TRUNC) | |
3452 | iter->hash = alloc_ftrace_hash(size_bits); | |
3453 | else | |
3454 | iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash); | |
3455 | ||
33dc9b12 SR |
3456 | if (!iter->hash) { |
3457 | trace_parser_put(&iter->parser); | |
3458 | kfree(iter); | |
3f2367ba MH |
3459 | ret = -ENOMEM; |
3460 | goto out_unlock; | |
33dc9b12 | 3461 | } |
c20489da SRV |
3462 | } else |
3463 | iter->hash = hash; | |
1cf41dd7 | 3464 | |
5072c59f SR |
3465 | if (file->f_mode & FMODE_READ) { |
3466 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
3467 | |
3468 | ret = seq_open(file, &show_ftrace_seq_ops); | |
3469 | if (!ret) { | |
3470 | struct seq_file *m = file->private_data; | |
3471 | m->private = iter; | |
79fe249c | 3472 | } else { |
33dc9b12 SR |
3473 | /* Failed */ |
3474 | free_ftrace_hash(iter->hash); | |
79fe249c | 3475 | trace_parser_put(&iter->parser); |
5072c59f | 3476 | kfree(iter); |
79fe249c | 3477 | } |
5072c59f SR |
3478 | } else |
3479 | file->private_data = iter; | |
3f2367ba MH |
3480 | |
3481 | out_unlock: | |
33b7f99c | 3482 | mutex_unlock(&ops->func_hash->regex_lock); |
5072c59f SR |
3483 | |
3484 | return ret; | |
3485 | } | |
3486 | ||
41c52c0d SR |
3487 | static int |
3488 | ftrace_filter_open(struct inode *inode, struct file *file) | |
3489 | { | |
e3b3e2e8 SRRH |
3490 | struct ftrace_ops *ops = inode->i_private; |
3491 | ||
3492 | return ftrace_regex_open(ops, | |
69a3083c SR |
3493 | FTRACE_ITER_FILTER | FTRACE_ITER_DO_HASH, |
3494 | inode, file); | |
41c52c0d SR |
3495 | } |
3496 | ||
3497 | static int | |
3498 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
3499 | { | |
e3b3e2e8 SRRH |
3500 | struct ftrace_ops *ops = inode->i_private; |
3501 | ||
3502 | return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE, | |
1cf41dd7 | 3503 | inode, file); |
41c52c0d SR |
3504 | } |
3505 | ||
3ba00929 DS |
3506 | /* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */ |
3507 | struct ftrace_glob { | |
3508 | char *search; | |
3509 | unsigned len; | |
3510 | int type; | |
3511 | }; | |
3512 | ||
7132e2d6 TJB |
3513 | /* |
3514 | * If symbols in an architecture don't correspond exactly to the user-visible | |
3515 | * name of what they represent, it is possible to define this function to | |
3516 | * perform the necessary adjustments. | |
3517 | */ | |
3518 | char * __weak arch_ftrace_match_adjust(char *str, const char *search) | |
3519 | { | |
3520 | return str; | |
3521 | } | |
3522 | ||
3ba00929 | 3523 | static int ftrace_match(char *str, struct ftrace_glob *g) |
9f4801e3 | 3524 | { |
9f4801e3 | 3525 | int matched = 0; |
751e9983 | 3526 | int slen; |
9f4801e3 | 3527 | |
7132e2d6 TJB |
3528 | str = arch_ftrace_match_adjust(str, g->search); |
3529 | ||
3ba00929 | 3530 | switch (g->type) { |
9f4801e3 | 3531 | case MATCH_FULL: |
3ba00929 | 3532 | if (strcmp(str, g->search) == 0) |
9f4801e3 SR |
3533 | matched = 1; |
3534 | break; | |
3535 | case MATCH_FRONT_ONLY: | |
3ba00929 | 3536 | if (strncmp(str, g->search, g->len) == 0) |
9f4801e3 SR |
3537 | matched = 1; |
3538 | break; | |
3539 | case MATCH_MIDDLE_ONLY: | |
3ba00929 | 3540 | if (strstr(str, g->search)) |
9f4801e3 SR |
3541 | matched = 1; |
3542 | break; | |
3543 | case MATCH_END_ONLY: | |
751e9983 | 3544 | slen = strlen(str); |
3ba00929 DS |
3545 | if (slen >= g->len && |
3546 | memcmp(str + slen - g->len, g->search, g->len) == 0) | |
9f4801e3 SR |
3547 | matched = 1; |
3548 | break; | |
60f1d5e3 MH |
3549 | case MATCH_GLOB: |
3550 | if (glob_match(g->search, str)) | |
3551 | matched = 1; | |
3552 | break; | |
9f4801e3 SR |
3553 | } |
3554 | ||
3555 | return matched; | |
3556 | } | |
3557 | ||
b448c4e3 | 3558 | static int |
f0a3b154 | 3559 | enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter) |
996e87be | 3560 | { |
b448c4e3 | 3561 | struct ftrace_func_entry *entry; |
b448c4e3 SR |
3562 | int ret = 0; |
3563 | ||
1cf41dd7 | 3564 | entry = ftrace_lookup_ip(hash, rec->ip); |
f0a3b154 | 3565 | if (clear_filter) { |
1cf41dd7 SR |
3566 | /* Do nothing if it doesn't exist */ |
3567 | if (!entry) | |
3568 | return 0; | |
b448c4e3 | 3569 | |
33dc9b12 | 3570 | free_hash_entry(hash, entry); |
1cf41dd7 SR |
3571 | } else { |
3572 | /* Do nothing if it exists */ | |
3573 | if (entry) | |
3574 | return 0; | |
b448c4e3 | 3575 | |
1cf41dd7 | 3576 | ret = add_hash_entry(hash, rec->ip); |
b448c4e3 SR |
3577 | } |
3578 | return ret; | |
996e87be SR |
3579 | } |
3580 | ||
64e7c440 | 3581 | static int |
0b507e1e DS |
3582 | ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g, |
3583 | struct ftrace_glob *mod_g, int exclude_mod) | |
64e7c440 SR |
3584 | { |
3585 | char str[KSYM_SYMBOL_LEN]; | |
b9df92d2 SR |
3586 | char *modname; |
3587 | ||
3588 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
3589 | ||
0b507e1e DS |
3590 | if (mod_g) { |
3591 | int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0; | |
3592 | ||
3593 | /* blank module name to match all modules */ | |
3594 | if (!mod_g->len) { | |
3595 | /* blank module globbing: modname xor exclude_mod */ | |
3596 | if ((!exclude_mod) != (!modname)) | |
3597 | goto func_match; | |
3598 | return 0; | |
3599 | } | |
3600 | ||
3601 | /* not matching the module */ | |
3602 | if (!modname || !mod_matches) { | |
3603 | if (exclude_mod) | |
3604 | goto func_match; | |
3605 | else | |
3606 | return 0; | |
3607 | } | |
3608 | ||
3609 | if (mod_matches && exclude_mod) | |
b9df92d2 SR |
3610 | return 0; |
3611 | ||
0b507e1e | 3612 | func_match: |
b9df92d2 | 3613 | /* blank search means to match all funcs in the mod */ |
3ba00929 | 3614 | if (!func_g->len) |
b9df92d2 SR |
3615 | return 1; |
3616 | } | |
64e7c440 | 3617 | |
3ba00929 | 3618 | return ftrace_match(str, func_g); |
64e7c440 SR |
3619 | } |
3620 | ||
1cf41dd7 | 3621 | static int |
3ba00929 | 3622 | match_records(struct ftrace_hash *hash, char *func, int len, char *mod) |
9f4801e3 | 3623 | { |
9f4801e3 SR |
3624 | struct ftrace_page *pg; |
3625 | struct dyn_ftrace *rec; | |
3ba00929 | 3626 | struct ftrace_glob func_g = { .type = MATCH_FULL }; |
0b507e1e DS |
3627 | struct ftrace_glob mod_g = { .type = MATCH_FULL }; |
3628 | struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL; | |
3629 | int exclude_mod = 0; | |
311d16da | 3630 | int found = 0; |
b448c4e3 | 3631 | int ret; |
f0a3b154 | 3632 | int clear_filter; |
9f4801e3 | 3633 | |
0b507e1e | 3634 | if (func) { |
3ba00929 DS |
3635 | func_g.type = filter_parse_regex(func, len, &func_g.search, |
3636 | &clear_filter); | |
3637 | func_g.len = strlen(func_g.search); | |
b9df92d2 | 3638 | } |
9f4801e3 | 3639 | |
0b507e1e DS |
3640 | if (mod) { |
3641 | mod_g.type = filter_parse_regex(mod, strlen(mod), | |
3642 | &mod_g.search, &exclude_mod); | |
3643 | mod_g.len = strlen(mod_g.search); | |
b9df92d2 | 3644 | } |
9f4801e3 | 3645 | |
52baf119 | 3646 | mutex_lock(&ftrace_lock); |
265c831c | 3647 | |
b9df92d2 SR |
3648 | if (unlikely(ftrace_disabled)) |
3649 | goto out_unlock; | |
9f4801e3 | 3650 | |
265c831c | 3651 | do_for_each_ftrace_rec(pg, rec) { |
546fece4 SRRH |
3652 | |
3653 | if (rec->flags & FTRACE_FL_DISABLED) | |
3654 | continue; | |
3655 | ||
0b507e1e | 3656 | if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) { |
f0a3b154 | 3657 | ret = enter_record(hash, rec, clear_filter); |
b448c4e3 SR |
3658 | if (ret < 0) { |
3659 | found = ret; | |
3660 | goto out_unlock; | |
3661 | } | |
311d16da | 3662 | found = 1; |
265c831c SR |
3663 | } |
3664 | } while_for_each_ftrace_rec(); | |
b9df92d2 | 3665 | out_unlock: |
52baf119 | 3666 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
3667 | |
3668 | return found; | |
5072c59f SR |
3669 | } |
3670 | ||
64e7c440 | 3671 | static int |
1cf41dd7 | 3672 | ftrace_match_records(struct ftrace_hash *hash, char *buff, int len) |
64e7c440 | 3673 | { |
f0a3b154 | 3674 | return match_records(hash, buff, len, NULL); |
64e7c440 SR |
3675 | } |
3676 | ||
e16b35dd SRV |
3677 | static void ftrace_ops_update_code(struct ftrace_ops *ops, |
3678 | struct ftrace_ops_hash *old_hash) | |
3679 | { | |
3680 | struct ftrace_ops *op; | |
3681 | ||
3682 | if (!ftrace_enabled) | |
3683 | return; | |
3684 | ||
3685 | if (ops->flags & FTRACE_OPS_FL_ENABLED) { | |
3686 | ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash); | |
3687 | return; | |
3688 | } | |
3689 | ||
3690 | /* | |
3691 | * If this is the shared global_ops filter, then we need to | |
3692 | * check if there is another ops that shares it, is enabled. | |
3693 | * If so, we still need to run the modify code. | |
3694 | */ | |
3695 | if (ops->func_hash != &global_ops.local_hash) | |
3696 | return; | |
3697 | ||
3698 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
3699 | if (op->func_hash == &global_ops.local_hash && | |
3700 | op->flags & FTRACE_OPS_FL_ENABLED) { | |
3701 | ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash); | |
3702 | /* Only need to do this once */ | |
3703 | return; | |
3704 | } | |
3705 | } while_for_each_ftrace_op(op); | |
3706 | } | |
3707 | ||
3708 | static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops, | |
3709 | struct ftrace_hash **orig_hash, | |
3710 | struct ftrace_hash *hash, | |
3711 | int enable) | |
3712 | { | |
3713 | struct ftrace_ops_hash old_hash_ops; | |
3714 | struct ftrace_hash *old_hash; | |
3715 | int ret; | |
3716 | ||
3717 | old_hash = *orig_hash; | |
3718 | old_hash_ops.filter_hash = ops->func_hash->filter_hash; | |
3719 | old_hash_ops.notrace_hash = ops->func_hash->notrace_hash; | |
3720 | ret = ftrace_hash_move(ops, enable, orig_hash, hash); | |
3721 | if (!ret) { | |
3722 | ftrace_ops_update_code(ops, &old_hash_ops); | |
3723 | free_ftrace_hash_rcu(old_hash); | |
3724 | } | |
3725 | return ret; | |
3726 | } | |
64e7c440 | 3727 | |
f6180773 SR |
3728 | /* |
3729 | * We register the module command as a template to show others how | |
3730 | * to register the a command as well. | |
3731 | */ | |
3732 | ||
3733 | static int | |
43dd61c9 | 3734 | ftrace_mod_callback(struct ftrace_hash *hash, |
f0a3b154 | 3735 | char *func, char *cmd, char *module, int enable) |
f6180773 | 3736 | { |
5e3949f0 | 3737 | int ret; |
f6180773 SR |
3738 | |
3739 | /* | |
3740 | * cmd == 'mod' because we only registered this func | |
3741 | * for the 'mod' ftrace_func_command. | |
3742 | * But if you register one func with multiple commands, | |
3743 | * you can tell which command was used by the cmd | |
3744 | * parameter. | |
3745 | */ | |
f0a3b154 | 3746 | ret = match_records(hash, func, strlen(func), module); |
b448c4e3 | 3747 | if (!ret) |
5e3949f0 | 3748 | return -EINVAL; |
b448c4e3 SR |
3749 | if (ret < 0) |
3750 | return ret; | |
b448c4e3 | 3751 | return 0; |
f6180773 SR |
3752 | } |
3753 | ||
3754 | static struct ftrace_func_command ftrace_mod_cmd = { | |
3755 | .name = "mod", | |
3756 | .func = ftrace_mod_callback, | |
3757 | }; | |
3758 | ||
3759 | static int __init ftrace_mod_cmd_init(void) | |
3760 | { | |
3761 | return register_ftrace_command(&ftrace_mod_cmd); | |
3762 | } | |
6f415672 | 3763 | core_initcall(ftrace_mod_cmd_init); |
f6180773 | 3764 | |
2f5f6ad9 | 3765 | static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 3766 | struct ftrace_ops *op, struct pt_regs *pt_regs) |
59df055f | 3767 | { |
b6887d79 | 3768 | struct ftrace_func_probe *entry; |
59df055f | 3769 | struct hlist_head *hhd; |
59df055f | 3770 | unsigned long key; |
59df055f SR |
3771 | |
3772 | key = hash_long(ip, FTRACE_HASH_BITS); | |
3773 | ||
3774 | hhd = &ftrace_func_hash[key]; | |
3775 | ||
3776 | if (hlist_empty(hhd)) | |
3777 | return; | |
3778 | ||
3779 | /* | |
3780 | * Disable preemption for these calls to prevent a RCU grace | |
3781 | * period. This syncs the hash iteration and freeing of items | |
3782 | * on the hash. rcu_read_lock is too dangerous here. | |
3783 | */ | |
5168ae50 | 3784 | preempt_disable_notrace(); |
1bb539ca | 3785 | hlist_for_each_entry_rcu_notrace(entry, hhd, node) { |
59df055f | 3786 | if (entry->ip == ip) |
1a48df00 | 3787 | entry->ops->func(ip, parent_ip, entry->ops, NULL); |
59df055f | 3788 | } |
5168ae50 | 3789 | preempt_enable_notrace(); |
59df055f SR |
3790 | } |
3791 | ||
7818b388 | 3792 | static void ftrace_free_entry(struct ftrace_func_probe *entry) |
59df055f | 3793 | { |
59df055f | 3794 | if (entry->ops->free) |
1a48df00 | 3795 | entry->ops->free(entry->ops, entry->ip, NULL); |
59df055f SR |
3796 | kfree(entry); |
3797 | } | |
3798 | ||
41794f19 SRV |
3799 | struct ftrace_func_map { |
3800 | struct ftrace_func_entry entry; | |
3801 | void *data; | |
3802 | }; | |
3803 | ||
3804 | struct ftrace_func_mapper { | |
3805 | struct ftrace_hash hash; | |
3806 | }; | |
3807 | ||
3808 | /** | |
3809 | * allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper | |
3810 | * | |
3811 | * Returns a ftrace_func_mapper descriptor that can be used to map ips to data. | |
3812 | */ | |
3813 | struct ftrace_func_mapper *allocate_ftrace_func_mapper(void) | |
3814 | { | |
3815 | struct ftrace_hash *hash; | |
3816 | ||
3817 | /* | |
3818 | * The mapper is simply a ftrace_hash, but since the entries | |
3819 | * in the hash are not ftrace_func_entry type, we define it | |
3820 | * as a separate structure. | |
3821 | */ | |
3822 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); | |
3823 | return (struct ftrace_func_mapper *)hash; | |
3824 | } | |
3825 | ||
3826 | /** | |
3827 | * ftrace_func_mapper_find_ip - Find some data mapped to an ip | |
3828 | * @mapper: The mapper that has the ip maps | |
3829 | * @ip: the instruction pointer to find the data for | |
3830 | * | |
3831 | * Returns the data mapped to @ip if found otherwise NULL. The return | |
3832 | * is actually the address of the mapper data pointer. The address is | |
3833 | * returned for use cases where the data is no bigger than a long, and | |
3834 | * the user can use the data pointer as its data instead of having to | |
3835 | * allocate more memory for the reference. | |
3836 | */ | |
3837 | void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper, | |
3838 | unsigned long ip) | |
3839 | { | |
3840 | struct ftrace_func_entry *entry; | |
3841 | struct ftrace_func_map *map; | |
3842 | ||
3843 | entry = ftrace_lookup_ip(&mapper->hash, ip); | |
3844 | if (!entry) | |
3845 | return NULL; | |
3846 | ||
3847 | map = (struct ftrace_func_map *)entry; | |
3848 | return &map->data; | |
3849 | } | |
3850 | ||
3851 | /** | |
3852 | * ftrace_func_mapper_add_ip - Map some data to an ip | |
3853 | * @mapper: The mapper that has the ip maps | |
3854 | * @ip: The instruction pointer address to map @data to | |
3855 | * @data: The data to map to @ip | |
3856 | * | |
3857 | * Returns 0 on succes otherwise an error. | |
3858 | */ | |
3859 | int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper, | |
3860 | unsigned long ip, void *data) | |
3861 | { | |
3862 | struct ftrace_func_entry *entry; | |
3863 | struct ftrace_func_map *map; | |
3864 | ||
3865 | entry = ftrace_lookup_ip(&mapper->hash, ip); | |
3866 | if (entry) | |
3867 | return -EBUSY; | |
3868 | ||
3869 | map = kmalloc(sizeof(*map), GFP_KERNEL); | |
3870 | if (!map) | |
3871 | return -ENOMEM; | |
3872 | ||
3873 | map->entry.ip = ip; | |
3874 | map->data = data; | |
3875 | ||
3876 | __add_hash_entry(&mapper->hash, &map->entry); | |
3877 | ||
3878 | return 0; | |
3879 | } | |
3880 | ||
3881 | /** | |
3882 | * ftrace_func_mapper_remove_ip - Remove an ip from the mapping | |
3883 | * @mapper: The mapper that has the ip maps | |
3884 | * @ip: The instruction pointer address to remove the data from | |
3885 | * | |
3886 | * Returns the data if it is found, otherwise NULL. | |
3887 | * Note, if the data pointer is used as the data itself, (see | |
3888 | * ftrace_func_mapper_find_ip(), then the return value may be meaningless, | |
3889 | * if the data pointer was set to zero. | |
3890 | */ | |
3891 | void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper, | |
3892 | unsigned long ip) | |
3893 | { | |
3894 | struct ftrace_func_entry *entry; | |
3895 | struct ftrace_func_map *map; | |
3896 | void *data; | |
3897 | ||
3898 | entry = ftrace_lookup_ip(&mapper->hash, ip); | |
3899 | if (!entry) | |
3900 | return NULL; | |
3901 | ||
3902 | map = (struct ftrace_func_map *)entry; | |
3903 | data = map->data; | |
3904 | ||
3905 | remove_hash_entry(&mapper->hash, entry); | |
3906 | kfree(entry); | |
3907 | ||
3908 | return data; | |
3909 | } | |
3910 | ||
3911 | /** | |
3912 | * free_ftrace_func_mapper - free a mapping of ips and data | |
3913 | * @mapper: The mapper that has the ip maps | |
3914 | * @free_func: A function to be called on each data item. | |
3915 | * | |
3916 | * This is used to free the function mapper. The @free_func is optional | |
3917 | * and can be used if the data needs to be freed as well. | |
3918 | */ | |
3919 | void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper, | |
3920 | ftrace_mapper_func free_func) | |
3921 | { | |
3922 | struct ftrace_func_entry *entry; | |
3923 | struct ftrace_func_map *map; | |
3924 | struct hlist_head *hhd; | |
3925 | int size = 1 << mapper->hash.size_bits; | |
3926 | int i; | |
3927 | ||
3928 | if (free_func && mapper->hash.count) { | |
3929 | for (i = 0; i < size; i++) { | |
3930 | hhd = &mapper->hash.buckets[i]; | |
3931 | hlist_for_each_entry(entry, hhd, hlist) { | |
3932 | map = (struct ftrace_func_map *)entry; | |
3933 | free_func(map); | |
3934 | } | |
3935 | } | |
3936 | } | |
3937 | free_ftrace_hash(&mapper->hash); | |
3938 | } | |
3939 | ||
59df055f | 3940 | int |
b6887d79 | 3941 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
1ec3a81a | 3942 | void *data) |
59df055f | 3943 | { |
1ec3a81a SRV |
3944 | struct ftrace_func_entry *entry; |
3945 | struct ftrace_func_probe *probe; | |
3946 | struct ftrace_hash **orig_hash; | |
3947 | struct ftrace_hash *old_hash; | |
e1df4cb6 | 3948 | struct ftrace_hash *hash; |
1ec3a81a SRV |
3949 | struct hlist_head hl; |
3950 | struct hlist_node *n; | |
6a24a244 | 3951 | unsigned long key; |
59df055f | 3952 | int count = 0; |
1ec3a81a | 3953 | int size; |
e1df4cb6 | 3954 | int ret; |
1ec3a81a | 3955 | int i; |
59df055f | 3956 | |
1ec3a81a SRV |
3957 | /* We do not support '!' for function probes */ |
3958 | if (WARN_ON(glob[0] == '!')) | |
59df055f SR |
3959 | return -EINVAL; |
3960 | ||
1ec3a81a SRV |
3961 | if (!(ops->ops.flags & FTRACE_OPS_FL_INITIALIZED)) { |
3962 | ops->ops.func = function_trace_probe_call; | |
3963 | ftrace_ops_init(&ops->ops); | |
e1df4cb6 | 3964 | } |
59df055f | 3965 | |
1ec3a81a | 3966 | mutex_lock(&ops->ops.func_hash->regex_lock); |
5ae0bf59 | 3967 | |
1ec3a81a SRV |
3968 | orig_hash = &ops->ops.func_hash->filter_hash; |
3969 | old_hash = *orig_hash; | |
3970 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); | |
59df055f | 3971 | |
1ec3a81a | 3972 | ret = ftrace_match_records(hash, glob, strlen(glob)); |
546fece4 | 3973 | |
1ec3a81a SRV |
3974 | /* Nothing found? */ |
3975 | if (!ret) | |
3976 | ret = -EINVAL; | |
59df055f | 3977 | |
1ec3a81a SRV |
3978 | if (ret < 0) |
3979 | goto out; | |
59df055f | 3980 | |
1ec3a81a | 3981 | INIT_HLIST_HEAD(&hl); |
59df055f | 3982 | |
1ec3a81a SRV |
3983 | size = 1 << hash->size_bits; |
3984 | for (i = 0; i < size; i++) { | |
3985 | hlist_for_each_entry(entry, &hash->buckets[i], hlist) { | |
3986 | if (ftrace_lookup_ip(old_hash, entry->ip)) | |
59df055f | 3987 | continue; |
1ec3a81a SRV |
3988 | probe = kmalloc(sizeof(*probe), GFP_KERNEL); |
3989 | if (!probe) { | |
3990 | count = -ENOMEM; | |
3991 | goto err_free; | |
59df055f | 3992 | } |
1ec3a81a SRV |
3993 | probe->ops = ops; |
3994 | probe->ip = entry->ip; | |
3995 | /* | |
3996 | * The caller might want to do something special | |
3997 | * for each function we find. We call the callback | |
3998 | * to give the caller an opportunity to do so. | |
3999 | */ | |
4000 | if (ops->init && ops->init(ops, entry->ip, data) < 0) { | |
4001 | kfree(probe); | |
4002 | goto err_free; | |
4003 | } | |
4004 | hlist_add_head(&probe->node, &hl); | |
59df055f | 4005 | |
1ec3a81a | 4006 | count++; |
e1df4cb6 | 4007 | } |
1ec3a81a | 4008 | } |
e1df4cb6 | 4009 | |
1ec3a81a | 4010 | mutex_lock(&ftrace_lock); |
59df055f | 4011 | |
1ec3a81a SRV |
4012 | ret = ftrace_hash_move_and_update_ops(&ops->ops, orig_hash, |
4013 | hash, 1); | |
4014 | if (ret < 0) | |
4015 | goto err_free_unlock; | |
59df055f | 4016 | |
1ec3a81a SRV |
4017 | hlist_for_each_entry_safe(probe, n, &hl, node) { |
4018 | hlist_del(&probe->node); | |
4019 | key = hash_long(probe->ip, FTRACE_HASH_BITS); | |
4020 | hlist_add_head_rcu(&probe->node, &ftrace_func_hash[key]); | |
4021 | } | |
e1df4cb6 | 4022 | |
1ec3a81a SRV |
4023 | if (!(ops->ops.flags & FTRACE_OPS_FL_ENABLED)) |
4024 | ret = ftrace_startup(&ops->ops, 0); | |
8252ecf3 | 4025 | |
1ec3a81a | 4026 | mutex_unlock(&ftrace_lock); |
8252ecf3 | 4027 | |
3296fc4e | 4028 | if (!ret) |
1ec3a81a | 4029 | ret = count; |
5ae0bf59 | 4030 | out: |
1ec3a81a | 4031 | mutex_unlock(&ops->ops.func_hash->regex_lock); |
e1df4cb6 | 4032 | free_ftrace_hash(hash); |
59df055f | 4033 | |
1ec3a81a SRV |
4034 | return ret; |
4035 | ||
4036 | err_free_unlock: | |
4037 | mutex_unlock(&ftrace_lock); | |
4038 | err_free: | |
4039 | hlist_for_each_entry_safe(probe, n, &hl, node) { | |
4040 | hlist_del(&probe->node); | |
4041 | if (ops->free) | |
4042 | ops->free(ops, probe->ip, NULL); | |
4043 | kfree(probe); | |
4044 | } | |
4045 | goto out; | |
59df055f SR |
4046 | } |
4047 | ||
d3d532d7 | 4048 | int |
78f78e07 | 4049 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 4050 | { |
acceb72e | 4051 | struct ftrace_ops_hash old_hash_ops; |
e1df4cb6 | 4052 | struct ftrace_func_entry *rec_entry; |
b6887d79 | 4053 | struct ftrace_func_probe *entry; |
7818b388 | 4054 | struct ftrace_func_probe *p; |
3ba00929 | 4055 | struct ftrace_glob func_g; |
1ec3a81a SRV |
4056 | struct ftrace_hash **orig_hash; |
4057 | struct ftrace_hash *old_hash; | |
7818b388 | 4058 | struct list_head free_list; |
1ec3a81a | 4059 | struct ftrace_hash *hash = NULL; |
b67bfe0d | 4060 | struct hlist_node *tmp; |
59df055f | 4061 | char str[KSYM_SYMBOL_LEN]; |
3ba00929 | 4062 | int i, ret; |
1ec3a81a SRV |
4063 | |
4064 | if (!(ops->ops.flags & FTRACE_OPS_FL_INITIALIZED)) | |
4065 | return -EINVAL; | |
59df055f | 4066 | |
b36461da | 4067 | if (glob && (strcmp(glob, "*") == 0 || !strlen(glob))) |
3ba00929 | 4068 | func_g.search = NULL; |
b36461da | 4069 | else if (glob) { |
59df055f SR |
4070 | int not; |
4071 | ||
3ba00929 DS |
4072 | func_g.type = filter_parse_regex(glob, strlen(glob), |
4073 | &func_g.search, ¬); | |
4074 | func_g.len = strlen(func_g.search); | |
4075 | func_g.search = glob; | |
59df055f | 4076 | |
b6887d79 | 4077 | /* we do not support '!' for function probes */ |
59df055f | 4078 | if (WARN_ON(not)) |
d3d532d7 | 4079 | return -EINVAL; |
59df055f SR |
4080 | } |
4081 | ||
1ec3a81a SRV |
4082 | mutex_lock(&ops->ops.func_hash->regex_lock); |
4083 | ||
4084 | orig_hash = &ops->ops.func_hash->filter_hash; | |
4085 | old_hash = *orig_hash; | |
4086 | ||
4087 | ret = -EINVAL; | |
4088 | if (ftrace_hash_empty(old_hash)) | |
4089 | goto out_unlock; | |
e1df4cb6 | 4090 | |
acceb72e SRV |
4091 | old_hash_ops.filter_hash = old_hash; |
4092 | /* Probes only have filters */ | |
4093 | old_hash_ops.notrace_hash = NULL; | |
4094 | ||
d3d532d7 | 4095 | ret = -ENOMEM; |
1ec3a81a | 4096 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash); |
e1df4cb6 | 4097 | if (!hash) |
e1df4cb6 SRRH |
4098 | goto out_unlock; |
4099 | ||
7818b388 SRRH |
4100 | INIT_LIST_HEAD(&free_list); |
4101 | ||
59df055f SR |
4102 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { |
4103 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
4104 | ||
b67bfe0d | 4105 | hlist_for_each_entry_safe(entry, tmp, hhd, node) { |
59df055f SR |
4106 | |
4107 | /* break up if statements for readability */ | |
78f78e07 | 4108 | if (entry->ops != ops) |
59df055f SR |
4109 | continue; |
4110 | ||
59df055f | 4111 | /* do this last, since it is the most expensive */ |
3ba00929 | 4112 | if (func_g.search) { |
59df055f SR |
4113 | kallsyms_lookup(entry->ip, NULL, NULL, |
4114 | NULL, str); | |
3ba00929 | 4115 | if (!ftrace_match(str, &func_g)) |
59df055f SR |
4116 | continue; |
4117 | } | |
4118 | ||
e1df4cb6 SRRH |
4119 | rec_entry = ftrace_lookup_ip(hash, entry->ip); |
4120 | /* It is possible more than one entry had this ip */ | |
4121 | if (rec_entry) | |
4122 | free_hash_entry(hash, rec_entry); | |
4123 | ||
740466bc | 4124 | hlist_del_rcu(&entry->node); |
7818b388 | 4125 | list_add(&entry->free_list, &free_list); |
59df055f SR |
4126 | } |
4127 | } | |
d3d532d7 SRV |
4128 | |
4129 | /* Nothing found? */ | |
4130 | if (list_empty(&free_list)) { | |
4131 | ret = -EINVAL; | |
4132 | goto out_unlock; | |
4133 | } | |
4134 | ||
3f2367ba | 4135 | mutex_lock(&ftrace_lock); |
1ec3a81a SRV |
4136 | |
4137 | if (ftrace_hash_empty(hash)) | |
4138 | ftrace_shutdown(&ops->ops, 0); | |
4139 | ||
4140 | ret = ftrace_hash_move_and_update_ops(&ops->ops, orig_hash, | |
4141 | hash, 1); | |
acceb72e SRV |
4142 | |
4143 | /* still need to update the function call sites */ | |
1ec3a81a SRV |
4144 | if (ftrace_enabled && !ftrace_hash_empty(hash)) |
4145 | ftrace_run_modify_code(&ops->ops, FTRACE_UPDATE_CALLS, | |
acceb72e | 4146 | &old_hash_ops); |
7818b388 | 4147 | synchronize_sched(); |
3296fc4e | 4148 | |
7818b388 SRRH |
4149 | list_for_each_entry_safe(entry, p, &free_list, free_list) { |
4150 | list_del(&entry->free_list); | |
4151 | ftrace_free_entry(entry); | |
4152 | } | |
3f2367ba | 4153 | mutex_unlock(&ftrace_lock); |
3ba00929 | 4154 | |
e1df4cb6 | 4155 | out_unlock: |
1ec3a81a | 4156 | mutex_unlock(&ops->ops.func_hash->regex_lock); |
e1df4cb6 | 4157 | free_ftrace_hash(hash); |
d3d532d7 | 4158 | return ret; |
59df055f SR |
4159 | } |
4160 | ||
f6180773 SR |
4161 | static LIST_HEAD(ftrace_commands); |
4162 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
4163 | ||
38de93ab TZ |
4164 | /* |
4165 | * Currently we only register ftrace commands from __init, so mark this | |
4166 | * __init too. | |
4167 | */ | |
4168 | __init int register_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
4169 | { |
4170 | struct ftrace_func_command *p; | |
4171 | int ret = 0; | |
4172 | ||
4173 | mutex_lock(&ftrace_cmd_mutex); | |
4174 | list_for_each_entry(p, &ftrace_commands, list) { | |
4175 | if (strcmp(cmd->name, p->name) == 0) { | |
4176 | ret = -EBUSY; | |
4177 | goto out_unlock; | |
4178 | } | |
4179 | } | |
4180 | list_add(&cmd->list, &ftrace_commands); | |
4181 | out_unlock: | |
4182 | mutex_unlock(&ftrace_cmd_mutex); | |
4183 | ||
4184 | return ret; | |
4185 | } | |
4186 | ||
38de93ab TZ |
4187 | /* |
4188 | * Currently we only unregister ftrace commands from __init, so mark | |
4189 | * this __init too. | |
4190 | */ | |
4191 | __init int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
f6180773 SR |
4192 | { |
4193 | struct ftrace_func_command *p, *n; | |
4194 | int ret = -ENODEV; | |
4195 | ||
4196 | mutex_lock(&ftrace_cmd_mutex); | |
4197 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
4198 | if (strcmp(cmd->name, p->name) == 0) { | |
4199 | ret = 0; | |
4200 | list_del_init(&p->list); | |
4201 | goto out_unlock; | |
4202 | } | |
4203 | } | |
4204 | out_unlock: | |
4205 | mutex_unlock(&ftrace_cmd_mutex); | |
4206 | ||
4207 | return ret; | |
4208 | } | |
4209 | ||
33dc9b12 SR |
4210 | static int ftrace_process_regex(struct ftrace_hash *hash, |
4211 | char *buff, int len, int enable) | |
64e7c440 | 4212 | { |
f6180773 | 4213 | char *func, *command, *next = buff; |
6a24a244 | 4214 | struct ftrace_func_command *p; |
0aff1c0c | 4215 | int ret = -EINVAL; |
64e7c440 SR |
4216 | |
4217 | func = strsep(&next, ":"); | |
4218 | ||
4219 | if (!next) { | |
1cf41dd7 | 4220 | ret = ftrace_match_records(hash, func, len); |
b448c4e3 SR |
4221 | if (!ret) |
4222 | ret = -EINVAL; | |
4223 | if (ret < 0) | |
4224 | return ret; | |
4225 | return 0; | |
64e7c440 SR |
4226 | } |
4227 | ||
f6180773 | 4228 | /* command found */ |
64e7c440 SR |
4229 | |
4230 | command = strsep(&next, ":"); | |
4231 | ||
f6180773 SR |
4232 | mutex_lock(&ftrace_cmd_mutex); |
4233 | list_for_each_entry(p, &ftrace_commands, list) { | |
4234 | if (strcmp(p->name, command) == 0) { | |
43dd61c9 | 4235 | ret = p->func(hash, func, command, next, enable); |
f6180773 SR |
4236 | goto out_unlock; |
4237 | } | |
64e7c440 | 4238 | } |
f6180773 SR |
4239 | out_unlock: |
4240 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 4241 | |
f6180773 | 4242 | return ret; |
64e7c440 SR |
4243 | } |
4244 | ||
e309b41d | 4245 | static ssize_t |
41c52c0d SR |
4246 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
4247 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
4248 | { |
4249 | struct ftrace_iterator *iter; | |
689fd8b6 | 4250 | struct trace_parser *parser; |
4251 | ssize_t ret, read; | |
5072c59f | 4252 | |
4ba7978e | 4253 | if (!cnt) |
5072c59f SR |
4254 | return 0; |
4255 | ||
5072c59f SR |
4256 | if (file->f_mode & FMODE_READ) { |
4257 | struct seq_file *m = file->private_data; | |
4258 | iter = m->private; | |
4259 | } else | |
4260 | iter = file->private_data; | |
4261 | ||
f04f24fb | 4262 | if (unlikely(ftrace_disabled)) |
3f2367ba MH |
4263 | return -ENODEV; |
4264 | ||
4265 | /* iter->hash is a local copy, so we don't need regex_lock */ | |
f04f24fb | 4266 | |
689fd8b6 | 4267 | parser = &iter->parser; |
4268 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 4269 | |
4ba7978e | 4270 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 4271 | !trace_parser_cont(parser)) { |
33dc9b12 | 4272 | ret = ftrace_process_regex(iter->hash, parser->buffer, |
689fd8b6 | 4273 | parser->idx, enable); |
313254a9 | 4274 | trace_parser_clear(parser); |
7c088b51 | 4275 | if (ret < 0) |
3f2367ba | 4276 | goto out; |
eda1e328 | 4277 | } |
5072c59f | 4278 | |
5072c59f | 4279 | ret = read; |
3f2367ba | 4280 | out: |
5072c59f SR |
4281 | return ret; |
4282 | } | |
4283 | ||
fc13cb0c | 4284 | ssize_t |
41c52c0d SR |
4285 | ftrace_filter_write(struct file *file, const char __user *ubuf, |
4286 | size_t cnt, loff_t *ppos) | |
4287 | { | |
4288 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
4289 | } | |
4290 | ||
fc13cb0c | 4291 | ssize_t |
41c52c0d SR |
4292 | ftrace_notrace_write(struct file *file, const char __user *ubuf, |
4293 | size_t cnt, loff_t *ppos) | |
4294 | { | |
4295 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
4296 | } | |
4297 | ||
33dc9b12 | 4298 | static int |
647664ea MH |
4299 | ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) |
4300 | { | |
4301 | struct ftrace_func_entry *entry; | |
4302 | ||
4303 | if (!ftrace_location(ip)) | |
4304 | return -EINVAL; | |
4305 | ||
4306 | if (remove) { | |
4307 | entry = ftrace_lookup_ip(hash, ip); | |
4308 | if (!entry) | |
4309 | return -ENOENT; | |
4310 | free_hash_entry(hash, entry); | |
4311 | return 0; | |
4312 | } | |
4313 | ||
4314 | return add_hash_entry(hash, ip); | |
4315 | } | |
4316 | ||
4317 | static int | |
4318 | ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, | |
4319 | unsigned long ip, int remove, int reset, int enable) | |
41c52c0d | 4320 | { |
33dc9b12 | 4321 | struct ftrace_hash **orig_hash; |
f45948e8 | 4322 | struct ftrace_hash *hash; |
33dc9b12 | 4323 | int ret; |
f45948e8 | 4324 | |
41c52c0d | 4325 | if (unlikely(ftrace_disabled)) |
33dc9b12 | 4326 | return -ENODEV; |
41c52c0d | 4327 | |
33b7f99c | 4328 | mutex_lock(&ops->func_hash->regex_lock); |
3f2367ba | 4329 | |
f45948e8 | 4330 | if (enable) |
33b7f99c | 4331 | orig_hash = &ops->func_hash->filter_hash; |
f45948e8 | 4332 | else |
33b7f99c | 4333 | orig_hash = &ops->func_hash->notrace_hash; |
33dc9b12 | 4334 | |
b972cc58 WN |
4335 | if (reset) |
4336 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); | |
4337 | else | |
4338 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
4339 | ||
3f2367ba MH |
4340 | if (!hash) { |
4341 | ret = -ENOMEM; | |
4342 | goto out_regex_unlock; | |
4343 | } | |
f45948e8 | 4344 | |
ac483c44 JO |
4345 | if (buf && !ftrace_match_records(hash, buf, len)) { |
4346 | ret = -EINVAL; | |
4347 | goto out_regex_unlock; | |
4348 | } | |
647664ea MH |
4349 | if (ip) { |
4350 | ret = ftrace_match_addr(hash, ip, remove); | |
4351 | if (ret < 0) | |
4352 | goto out_regex_unlock; | |
4353 | } | |
33dc9b12 SR |
4354 | |
4355 | mutex_lock(&ftrace_lock); | |
e16b35dd | 4356 | ret = ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable); |
33dc9b12 SR |
4357 | mutex_unlock(&ftrace_lock); |
4358 | ||
ac483c44 | 4359 | out_regex_unlock: |
33b7f99c | 4360 | mutex_unlock(&ops->func_hash->regex_lock); |
33dc9b12 SR |
4361 | |
4362 | free_ftrace_hash(hash); | |
4363 | return ret; | |
41c52c0d SR |
4364 | } |
4365 | ||
647664ea MH |
4366 | static int |
4367 | ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove, | |
4368 | int reset, int enable) | |
4369 | { | |
4370 | return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable); | |
4371 | } | |
4372 | ||
4373 | /** | |
4374 | * ftrace_set_filter_ip - set a function to filter on in ftrace by address | |
4375 | * @ops - the ops to set the filter with | |
4376 | * @ip - the address to add to or remove from the filter. | |
4377 | * @remove - non zero to remove the ip from the filter | |
4378 | * @reset - non zero to reset all filters before applying this filter. | |
4379 | * | |
4380 | * Filters denote which functions should be enabled when tracing is enabled | |
4381 | * If @ip is NULL, it failes to update filter. | |
4382 | */ | |
4383 | int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, | |
4384 | int remove, int reset) | |
4385 | { | |
f04f24fb | 4386 | ftrace_ops_init(ops); |
647664ea MH |
4387 | return ftrace_set_addr(ops, ip, remove, reset, 1); |
4388 | } | |
4389 | EXPORT_SYMBOL_GPL(ftrace_set_filter_ip); | |
4390 | ||
d032ae89 JF |
4391 | /** |
4392 | * ftrace_ops_set_global_filter - setup ops to use global filters | |
4393 | * @ops - the ops which will use the global filters | |
4394 | * | |
4395 | * ftrace users who need global function trace filtering should call this. | |
4396 | * It can set the global filter only if ops were not initialized before. | |
4397 | */ | |
4398 | void ftrace_ops_set_global_filter(struct ftrace_ops *ops) | |
4399 | { | |
4400 | if (ops->flags & FTRACE_OPS_FL_INITIALIZED) | |
4401 | return; | |
4402 | ||
4403 | ftrace_ops_init(ops); | |
4404 | ops->func_hash = &global_ops.local_hash; | |
4405 | } | |
4406 | EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter); | |
4407 | ||
647664ea MH |
4408 | static int |
4409 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, | |
4410 | int reset, int enable) | |
4411 | { | |
4412 | return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable); | |
4413 | } | |
4414 | ||
77a2b37d SR |
4415 | /** |
4416 | * ftrace_set_filter - set a function to filter on in ftrace | |
936e074b SR |
4417 | * @ops - the ops to set the filter with |
4418 | * @buf - the string that holds the function filter text. | |
4419 | * @len - the length of the string. | |
4420 | * @reset - non zero to reset all filters before applying this filter. | |
4421 | * | |
4422 | * Filters denote which functions should be enabled when tracing is enabled. | |
4423 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
4424 | */ | |
ac483c44 | 4425 | int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
4426 | int len, int reset) |
4427 | { | |
f04f24fb | 4428 | ftrace_ops_init(ops); |
ac483c44 | 4429 | return ftrace_set_regex(ops, buf, len, reset, 1); |
936e074b SR |
4430 | } |
4431 | EXPORT_SYMBOL_GPL(ftrace_set_filter); | |
4432 | ||
4433 | /** | |
4434 | * ftrace_set_notrace - set a function to not trace in ftrace | |
4435 | * @ops - the ops to set the notrace filter with | |
4436 | * @buf - the string that holds the function notrace text. | |
4437 | * @len - the length of the string. | |
4438 | * @reset - non zero to reset all filters before applying this filter. | |
4439 | * | |
4440 | * Notrace Filters denote which functions should not be enabled when tracing | |
4441 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
4442 | * for tracing. | |
4443 | */ | |
ac483c44 | 4444 | int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
4445 | int len, int reset) |
4446 | { | |
f04f24fb | 4447 | ftrace_ops_init(ops); |
ac483c44 | 4448 | return ftrace_set_regex(ops, buf, len, reset, 0); |
936e074b SR |
4449 | } |
4450 | EXPORT_SYMBOL_GPL(ftrace_set_notrace); | |
4451 | /** | |
8d1b065d | 4452 | * ftrace_set_global_filter - set a function to filter on with global tracers |
77a2b37d SR |
4453 | * @buf - the string that holds the function filter text. |
4454 | * @len - the length of the string. | |
4455 | * @reset - non zero to reset all filters before applying this filter. | |
4456 | * | |
4457 | * Filters denote which functions should be enabled when tracing is enabled. | |
4458 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
4459 | */ | |
936e074b | 4460 | void ftrace_set_global_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 4461 | { |
f45948e8 | 4462 | ftrace_set_regex(&global_ops, buf, len, reset, 1); |
41c52c0d | 4463 | } |
936e074b | 4464 | EXPORT_SYMBOL_GPL(ftrace_set_global_filter); |
4eebcc81 | 4465 | |
41c52c0d | 4466 | /** |
8d1b065d | 4467 | * ftrace_set_global_notrace - set a function to not trace with global tracers |
41c52c0d SR |
4468 | * @buf - the string that holds the function notrace text. |
4469 | * @len - the length of the string. | |
4470 | * @reset - non zero to reset all filters before applying this filter. | |
4471 | * | |
4472 | * Notrace Filters denote which functions should not be enabled when tracing | |
4473 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
4474 | * for tracing. | |
4475 | */ | |
936e074b | 4476 | void ftrace_set_global_notrace(unsigned char *buf, int len, int reset) |
41c52c0d | 4477 | { |
f45948e8 | 4478 | ftrace_set_regex(&global_ops, buf, len, reset, 0); |
77a2b37d | 4479 | } |
936e074b | 4480 | EXPORT_SYMBOL_GPL(ftrace_set_global_notrace); |
77a2b37d | 4481 | |
2af15d6a SR |
4482 | /* |
4483 | * command line interface to allow users to set filters on boot up. | |
4484 | */ | |
4485 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
4486 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
4487 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
4488 | ||
f1ed7c74 SRRH |
4489 | /* Used by function selftest to not test if filter is set */ |
4490 | bool ftrace_filter_param __initdata; | |
4491 | ||
2af15d6a SR |
4492 | static int __init set_ftrace_notrace(char *str) |
4493 | { | |
f1ed7c74 | 4494 | ftrace_filter_param = true; |
75761cc1 | 4495 | strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
4496 | return 1; |
4497 | } | |
4498 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
4499 | ||
4500 | static int __init set_ftrace_filter(char *str) | |
4501 | { | |
f1ed7c74 | 4502 | ftrace_filter_param = true; |
75761cc1 | 4503 | strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); |
2af15d6a SR |
4504 | return 1; |
4505 | } | |
4506 | __setup("ftrace_filter=", set_ftrace_filter); | |
4507 | ||
369bc18f | 4508 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 4509 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
0d7d9a16 | 4510 | static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata; |
b9b0c831 | 4511 | static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer); |
801c29fd | 4512 | |
f3bea491 SRRH |
4513 | static unsigned long save_global_trampoline; |
4514 | static unsigned long save_global_flags; | |
4515 | ||
369bc18f SA |
4516 | static int __init set_graph_function(char *str) |
4517 | { | |
06f43d66 | 4518 | strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
4519 | return 1; |
4520 | } | |
4521 | __setup("ftrace_graph_filter=", set_graph_function); | |
4522 | ||
0d7d9a16 NK |
4523 | static int __init set_graph_notrace_function(char *str) |
4524 | { | |
4525 | strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE); | |
4526 | return 1; | |
4527 | } | |
4528 | __setup("ftrace_graph_notrace=", set_graph_notrace_function); | |
4529 | ||
65a50c65 TB |
4530 | static int __init set_graph_max_depth_function(char *str) |
4531 | { | |
4532 | if (!str) | |
4533 | return 0; | |
4534 | fgraph_max_depth = simple_strtoul(str, NULL, 0); | |
4535 | return 1; | |
4536 | } | |
4537 | __setup("ftrace_graph_max_depth=", set_graph_max_depth_function); | |
0d7d9a16 NK |
4538 | |
4539 | static void __init set_ftrace_early_graph(char *buf, int enable) | |
369bc18f SA |
4540 | { |
4541 | int ret; | |
4542 | char *func; | |
b9b0c831 | 4543 | struct ftrace_hash *hash; |
0d7d9a16 | 4544 | |
92ad18ec SRV |
4545 | hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS); |
4546 | if (WARN_ON(!hash)) | |
4547 | return; | |
369bc18f SA |
4548 | |
4549 | while (buf) { | |
4550 | func = strsep(&buf, ","); | |
4551 | /* we allow only one expression at a time */ | |
b9b0c831 | 4552 | ret = ftrace_graph_set_hash(hash, func); |
369bc18f SA |
4553 | if (ret) |
4554 | printk(KERN_DEBUG "ftrace: function %s not " | |
4555 | "traceable\n", func); | |
4556 | } | |
92ad18ec SRV |
4557 | |
4558 | if (enable) | |
4559 | ftrace_graph_hash = hash; | |
4560 | else | |
4561 | ftrace_graph_notrace_hash = hash; | |
369bc18f SA |
4562 | } |
4563 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
4564 | ||
2a85a37f SR |
4565 | void __init |
4566 | ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable) | |
2af15d6a SR |
4567 | { |
4568 | char *func; | |
4569 | ||
f04f24fb MH |
4570 | ftrace_ops_init(ops); |
4571 | ||
2af15d6a SR |
4572 | while (buf) { |
4573 | func = strsep(&buf, ","); | |
f45948e8 | 4574 | ftrace_set_regex(ops, func, strlen(func), 0, enable); |
2af15d6a SR |
4575 | } |
4576 | } | |
4577 | ||
4578 | static void __init set_ftrace_early_filters(void) | |
4579 | { | |
4580 | if (ftrace_filter_buf[0]) | |
2a85a37f | 4581 | ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1); |
2af15d6a | 4582 | if (ftrace_notrace_buf[0]) |
2a85a37f | 4583 | ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0); |
369bc18f SA |
4584 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
4585 | if (ftrace_graph_buf[0]) | |
0d7d9a16 NK |
4586 | set_ftrace_early_graph(ftrace_graph_buf, 1); |
4587 | if (ftrace_graph_notrace_buf[0]) | |
4588 | set_ftrace_early_graph(ftrace_graph_notrace_buf, 0); | |
369bc18f | 4589 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
2af15d6a SR |
4590 | } |
4591 | ||
fc13cb0c | 4592 | int ftrace_regex_release(struct inode *inode, struct file *file) |
5072c59f SR |
4593 | { |
4594 | struct seq_file *m = (struct seq_file *)file->private_data; | |
4595 | struct ftrace_iterator *iter; | |
33dc9b12 | 4596 | struct ftrace_hash **orig_hash; |
689fd8b6 | 4597 | struct trace_parser *parser; |
ed926f9b | 4598 | int filter_hash; |
33dc9b12 | 4599 | int ret; |
5072c59f | 4600 | |
5072c59f SR |
4601 | if (file->f_mode & FMODE_READ) { |
4602 | iter = m->private; | |
5072c59f SR |
4603 | seq_release(inode, file); |
4604 | } else | |
4605 | iter = file->private_data; | |
4606 | ||
689fd8b6 | 4607 | parser = &iter->parser; |
4608 | if (trace_parser_loaded(parser)) { | |
4609 | parser->buffer[parser->idx] = 0; | |
1cf41dd7 | 4610 | ftrace_match_records(iter->hash, parser->buffer, parser->idx); |
5072c59f SR |
4611 | } |
4612 | ||
689fd8b6 | 4613 | trace_parser_put(parser); |
689fd8b6 | 4614 | |
33b7f99c | 4615 | mutex_lock(&iter->ops->func_hash->regex_lock); |
3f2367ba | 4616 | |
058e297d | 4617 | if (file->f_mode & FMODE_WRITE) { |
ed926f9b SR |
4618 | filter_hash = !!(iter->flags & FTRACE_ITER_FILTER); |
4619 | ||
4620 | if (filter_hash) | |
33b7f99c | 4621 | orig_hash = &iter->ops->func_hash->filter_hash; |
ed926f9b | 4622 | else |
33b7f99c | 4623 | orig_hash = &iter->ops->func_hash->notrace_hash; |
33dc9b12 | 4624 | |
058e297d | 4625 | mutex_lock(&ftrace_lock); |
e16b35dd SRV |
4626 | ret = ftrace_hash_move_and_update_ops(iter->ops, orig_hash, |
4627 | iter->hash, filter_hash); | |
058e297d | 4628 | mutex_unlock(&ftrace_lock); |
c20489da SRV |
4629 | } else { |
4630 | /* For read only, the hash is the ops hash */ | |
4631 | iter->hash = NULL; | |
058e297d | 4632 | } |
3f2367ba | 4633 | |
33b7f99c | 4634 | mutex_unlock(&iter->ops->func_hash->regex_lock); |
33dc9b12 SR |
4635 | free_ftrace_hash(iter->hash); |
4636 | kfree(iter); | |
058e297d | 4637 | |
5072c59f SR |
4638 | return 0; |
4639 | } | |
4640 | ||
5e2336a0 | 4641 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
4642 | .open = ftrace_avail_open, |
4643 | .read = seq_read, | |
4644 | .llseek = seq_lseek, | |
3be04b47 | 4645 | .release = seq_release_private, |
5072c59f SR |
4646 | }; |
4647 | ||
647bcd03 SR |
4648 | static const struct file_operations ftrace_enabled_fops = { |
4649 | .open = ftrace_enabled_open, | |
4650 | .read = seq_read, | |
4651 | .llseek = seq_lseek, | |
4652 | .release = seq_release_private, | |
4653 | }; | |
4654 | ||
5e2336a0 | 4655 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 4656 | .open = ftrace_filter_open, |
850a80cf | 4657 | .read = seq_read, |
5072c59f | 4658 | .write = ftrace_filter_write, |
098c879e | 4659 | .llseek = tracing_lseek, |
1cf41dd7 | 4660 | .release = ftrace_regex_release, |
5072c59f SR |
4661 | }; |
4662 | ||
5e2336a0 | 4663 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 4664 | .open = ftrace_notrace_open, |
850a80cf | 4665 | .read = seq_read, |
41c52c0d | 4666 | .write = ftrace_notrace_write, |
098c879e | 4667 | .llseek = tracing_lseek, |
1cf41dd7 | 4668 | .release = ftrace_regex_release, |
41c52c0d SR |
4669 | }; |
4670 | ||
ea4e2bc4 SR |
4671 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
4672 | ||
4673 | static DEFINE_MUTEX(graph_lock); | |
4674 | ||
b9b0c831 NK |
4675 | struct ftrace_hash *ftrace_graph_hash = EMPTY_HASH; |
4676 | struct ftrace_hash *ftrace_graph_notrace_hash = EMPTY_HASH; | |
4677 | ||
4678 | enum graph_filter_type { | |
4679 | GRAPH_FILTER_NOTRACE = 0, | |
4680 | GRAPH_FILTER_FUNCTION, | |
4681 | }; | |
ea4e2bc4 | 4682 | |
555fc781 SRV |
4683 | #define FTRACE_GRAPH_EMPTY ((void *)1) |
4684 | ||
faf982a6 | 4685 | struct ftrace_graph_data { |
e704eff3 SRV |
4686 | struct ftrace_hash *hash; |
4687 | struct ftrace_func_entry *entry; | |
4688 | int idx; /* for hash table iteration */ | |
4689 | enum graph_filter_type type; | |
4690 | struct ftrace_hash *new_hash; | |
4691 | const struct seq_operations *seq_ops; | |
4692 | struct trace_parser parser; | |
faf982a6 NK |
4693 | }; |
4694 | ||
ea4e2bc4 | 4695 | static void * |
85951842 | 4696 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 4697 | { |
faf982a6 | 4698 | struct ftrace_graph_data *fgd = m->private; |
b9b0c831 NK |
4699 | struct ftrace_func_entry *entry = fgd->entry; |
4700 | struct hlist_head *head; | |
4701 | int i, idx = fgd->idx; | |
faf982a6 | 4702 | |
b9b0c831 | 4703 | if (*pos >= fgd->hash->count) |
ea4e2bc4 | 4704 | return NULL; |
b9b0c831 NK |
4705 | |
4706 | if (entry) { | |
4707 | hlist_for_each_entry_continue(entry, hlist) { | |
4708 | fgd->entry = entry; | |
4709 | return entry; | |
4710 | } | |
4711 | ||
4712 | idx++; | |
4713 | } | |
4714 | ||
4715 | for (i = idx; i < 1 << fgd->hash->size_bits; i++) { | |
4716 | head = &fgd->hash->buckets[i]; | |
4717 | hlist_for_each_entry(entry, head, hlist) { | |
4718 | fgd->entry = entry; | |
4719 | fgd->idx = i; | |
4720 | return entry; | |
4721 | } | |
4722 | } | |
4723 | return NULL; | |
85951842 | 4724 | } |
ea4e2bc4 | 4725 | |
85951842 LZ |
4726 | static void * |
4727 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
4728 | { | |
4729 | (*pos)++; | |
4730 | return __g_next(m, pos); | |
ea4e2bc4 SR |
4731 | } |
4732 | ||
4733 | static void *g_start(struct seq_file *m, loff_t *pos) | |
4734 | { | |
faf982a6 NK |
4735 | struct ftrace_graph_data *fgd = m->private; |
4736 | ||
ea4e2bc4 SR |
4737 | mutex_lock(&graph_lock); |
4738 | ||
649b988b SRV |
4739 | if (fgd->type == GRAPH_FILTER_FUNCTION) |
4740 | fgd->hash = rcu_dereference_protected(ftrace_graph_hash, | |
4741 | lockdep_is_held(&graph_lock)); | |
4742 | else | |
4743 | fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash, | |
4744 | lockdep_is_held(&graph_lock)); | |
4745 | ||
f9349a8f | 4746 | /* Nothing, tell g_show to print all functions are enabled */ |
b9b0c831 | 4747 | if (ftrace_hash_empty(fgd->hash) && !*pos) |
555fc781 | 4748 | return FTRACE_GRAPH_EMPTY; |
f9349a8f | 4749 | |
b9b0c831 NK |
4750 | fgd->idx = 0; |
4751 | fgd->entry = NULL; | |
85951842 | 4752 | return __g_next(m, pos); |
ea4e2bc4 SR |
4753 | } |
4754 | ||
4755 | static void g_stop(struct seq_file *m, void *p) | |
4756 | { | |
4757 | mutex_unlock(&graph_lock); | |
4758 | } | |
4759 | ||
4760 | static int g_show(struct seq_file *m, void *v) | |
4761 | { | |
b9b0c831 | 4762 | struct ftrace_func_entry *entry = v; |
ea4e2bc4 | 4763 | |
b9b0c831 | 4764 | if (!entry) |
ea4e2bc4 SR |
4765 | return 0; |
4766 | ||
555fc781 | 4767 | if (entry == FTRACE_GRAPH_EMPTY) { |
280d1429 NK |
4768 | struct ftrace_graph_data *fgd = m->private; |
4769 | ||
b9b0c831 | 4770 | if (fgd->type == GRAPH_FILTER_FUNCTION) |
fa6f0cc7 | 4771 | seq_puts(m, "#### all functions enabled ####\n"); |
280d1429 | 4772 | else |
fa6f0cc7 | 4773 | seq_puts(m, "#### no functions disabled ####\n"); |
f9349a8f FW |
4774 | return 0; |
4775 | } | |
4776 | ||
b9b0c831 | 4777 | seq_printf(m, "%ps\n", (void *)entry->ip); |
ea4e2bc4 SR |
4778 | |
4779 | return 0; | |
4780 | } | |
4781 | ||
88e9d34c | 4782 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
4783 | .start = g_start, |
4784 | .next = g_next, | |
4785 | .stop = g_stop, | |
4786 | .show = g_show, | |
4787 | }; | |
4788 | ||
4789 | static int | |
faf982a6 NK |
4790 | __ftrace_graph_open(struct inode *inode, struct file *file, |
4791 | struct ftrace_graph_data *fgd) | |
ea4e2bc4 SR |
4792 | { |
4793 | int ret = 0; | |
b9b0c831 | 4794 | struct ftrace_hash *new_hash = NULL; |
ea4e2bc4 | 4795 | |
b9b0c831 NK |
4796 | if (file->f_mode & FMODE_WRITE) { |
4797 | const int size_bits = FTRACE_HASH_DEFAULT_BITS; | |
4798 | ||
e704eff3 SRV |
4799 | if (trace_parser_get_init(&fgd->parser, FTRACE_BUFF_MAX)) |
4800 | return -ENOMEM; | |
4801 | ||
b9b0c831 NK |
4802 | if (file->f_flags & O_TRUNC) |
4803 | new_hash = alloc_ftrace_hash(size_bits); | |
4804 | else | |
4805 | new_hash = alloc_and_copy_ftrace_hash(size_bits, | |
4806 | fgd->hash); | |
4807 | if (!new_hash) { | |
4808 | ret = -ENOMEM; | |
4809 | goto out; | |
4810 | } | |
ea4e2bc4 SR |
4811 | } |
4812 | ||
faf982a6 | 4813 | if (file->f_mode & FMODE_READ) { |
b9b0c831 | 4814 | ret = seq_open(file, &ftrace_graph_seq_ops); |
faf982a6 NK |
4815 | if (!ret) { |
4816 | struct seq_file *m = file->private_data; | |
4817 | m->private = fgd; | |
b9b0c831 NK |
4818 | } else { |
4819 | /* Failed */ | |
4820 | free_ftrace_hash(new_hash); | |
4821 | new_hash = NULL; | |
faf982a6 NK |
4822 | } |
4823 | } else | |
4824 | file->private_data = fgd; | |
ea4e2bc4 | 4825 | |
b9b0c831 | 4826 | out: |
e704eff3 SRV |
4827 | if (ret < 0 && file->f_mode & FMODE_WRITE) |
4828 | trace_parser_put(&fgd->parser); | |
4829 | ||
b9b0c831 | 4830 | fgd->new_hash = new_hash; |
649b988b SRV |
4831 | |
4832 | /* | |
4833 | * All uses of fgd->hash must be taken with the graph_lock | |
4834 | * held. The graph_lock is going to be released, so force | |
4835 | * fgd->hash to be reinitialized when it is taken again. | |
4836 | */ | |
4837 | fgd->hash = NULL; | |
4838 | ||
ea4e2bc4 SR |
4839 | return ret; |
4840 | } | |
4841 | ||
faf982a6 NK |
4842 | static int |
4843 | ftrace_graph_open(struct inode *inode, struct file *file) | |
4844 | { | |
4845 | struct ftrace_graph_data *fgd; | |
b9b0c831 | 4846 | int ret; |
faf982a6 NK |
4847 | |
4848 | if (unlikely(ftrace_disabled)) | |
4849 | return -ENODEV; | |
4850 | ||
4851 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
4852 | if (fgd == NULL) | |
4853 | return -ENOMEM; | |
4854 | ||
b9b0c831 NK |
4855 | mutex_lock(&graph_lock); |
4856 | ||
649b988b SRV |
4857 | fgd->hash = rcu_dereference_protected(ftrace_graph_hash, |
4858 | lockdep_is_held(&graph_lock)); | |
b9b0c831 | 4859 | fgd->type = GRAPH_FILTER_FUNCTION; |
faf982a6 NK |
4860 | fgd->seq_ops = &ftrace_graph_seq_ops; |
4861 | ||
b9b0c831 NK |
4862 | ret = __ftrace_graph_open(inode, file, fgd); |
4863 | if (ret < 0) | |
4864 | kfree(fgd); | |
4865 | ||
4866 | mutex_unlock(&graph_lock); | |
4867 | return ret; | |
faf982a6 NK |
4868 | } |
4869 | ||
29ad23b0 NK |
4870 | static int |
4871 | ftrace_graph_notrace_open(struct inode *inode, struct file *file) | |
4872 | { | |
4873 | struct ftrace_graph_data *fgd; | |
b9b0c831 | 4874 | int ret; |
29ad23b0 NK |
4875 | |
4876 | if (unlikely(ftrace_disabled)) | |
4877 | return -ENODEV; | |
4878 | ||
4879 | fgd = kmalloc(sizeof(*fgd), GFP_KERNEL); | |
4880 | if (fgd == NULL) | |
4881 | return -ENOMEM; | |
4882 | ||
b9b0c831 NK |
4883 | mutex_lock(&graph_lock); |
4884 | ||
649b988b SRV |
4885 | fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash, |
4886 | lockdep_is_held(&graph_lock)); | |
b9b0c831 | 4887 | fgd->type = GRAPH_FILTER_NOTRACE; |
29ad23b0 NK |
4888 | fgd->seq_ops = &ftrace_graph_seq_ops; |
4889 | ||
b9b0c831 NK |
4890 | ret = __ftrace_graph_open(inode, file, fgd); |
4891 | if (ret < 0) | |
4892 | kfree(fgd); | |
4893 | ||
4894 | mutex_unlock(&graph_lock); | |
4895 | return ret; | |
29ad23b0 NK |
4896 | } |
4897 | ||
87827111 LZ |
4898 | static int |
4899 | ftrace_graph_release(struct inode *inode, struct file *file) | |
4900 | { | |
b9b0c831 | 4901 | struct ftrace_graph_data *fgd; |
e704eff3 SRV |
4902 | struct ftrace_hash *old_hash, *new_hash; |
4903 | struct trace_parser *parser; | |
4904 | int ret = 0; | |
b9b0c831 | 4905 | |
faf982a6 NK |
4906 | if (file->f_mode & FMODE_READ) { |
4907 | struct seq_file *m = file->private_data; | |
4908 | ||
b9b0c831 | 4909 | fgd = m->private; |
87827111 | 4910 | seq_release(inode, file); |
faf982a6 | 4911 | } else { |
b9b0c831 | 4912 | fgd = file->private_data; |
faf982a6 NK |
4913 | } |
4914 | ||
e704eff3 SRV |
4915 | |
4916 | if (file->f_mode & FMODE_WRITE) { | |
4917 | ||
4918 | parser = &fgd->parser; | |
4919 | ||
4920 | if (trace_parser_loaded((parser))) { | |
4921 | parser->buffer[parser->idx] = 0; | |
4922 | ret = ftrace_graph_set_hash(fgd->new_hash, | |
4923 | parser->buffer); | |
4924 | } | |
4925 | ||
4926 | trace_parser_put(parser); | |
4927 | ||
4928 | new_hash = __ftrace_hash_move(fgd->new_hash); | |
4929 | if (!new_hash) { | |
4930 | ret = -ENOMEM; | |
4931 | goto out; | |
4932 | } | |
4933 | ||
4934 | mutex_lock(&graph_lock); | |
4935 | ||
4936 | if (fgd->type == GRAPH_FILTER_FUNCTION) { | |
4937 | old_hash = rcu_dereference_protected(ftrace_graph_hash, | |
4938 | lockdep_is_held(&graph_lock)); | |
4939 | rcu_assign_pointer(ftrace_graph_hash, new_hash); | |
4940 | } else { | |
4941 | old_hash = rcu_dereference_protected(ftrace_graph_notrace_hash, | |
4942 | lockdep_is_held(&graph_lock)); | |
4943 | rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash); | |
4944 | } | |
4945 | ||
4946 | mutex_unlock(&graph_lock); | |
4947 | ||
4948 | /* Wait till all users are no longer using the old hash */ | |
4949 | synchronize_sched(); | |
4950 | ||
4951 | free_ftrace_hash(old_hash); | |
4952 | } | |
4953 | ||
4954 | out: | |
b9b0c831 NK |
4955 | kfree(fgd->new_hash); |
4956 | kfree(fgd); | |
4957 | ||
e704eff3 | 4958 | return ret; |
87827111 LZ |
4959 | } |
4960 | ||
ea4e2bc4 | 4961 | static int |
b9b0c831 | 4962 | ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer) |
ea4e2bc4 | 4963 | { |
3ba00929 | 4964 | struct ftrace_glob func_g; |
ea4e2bc4 SR |
4965 | struct dyn_ftrace *rec; |
4966 | struct ftrace_page *pg; | |
b9b0c831 | 4967 | struct ftrace_func_entry *entry; |
c7c6b1fe | 4968 | int fail = 1; |
3ba00929 | 4969 | int not; |
ea4e2bc4 | 4970 | |
f9349a8f | 4971 | /* decode regex */ |
3ba00929 DS |
4972 | func_g.type = filter_parse_regex(buffer, strlen(buffer), |
4973 | &func_g.search, ¬); | |
f9349a8f | 4974 | |
3ba00929 | 4975 | func_g.len = strlen(func_g.search); |
f9349a8f | 4976 | |
52baf119 | 4977 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
4978 | |
4979 | if (unlikely(ftrace_disabled)) { | |
4980 | mutex_unlock(&ftrace_lock); | |
4981 | return -ENODEV; | |
4982 | } | |
4983 | ||
265c831c SR |
4984 | do_for_each_ftrace_rec(pg, rec) { |
4985 | ||
546fece4 SRRH |
4986 | if (rec->flags & FTRACE_FL_DISABLED) |
4987 | continue; | |
4988 | ||
0b507e1e | 4989 | if (ftrace_match_record(rec, &func_g, NULL, 0)) { |
b9b0c831 | 4990 | entry = ftrace_lookup_ip(hash, rec->ip); |
c7c6b1fe LZ |
4991 | |
4992 | if (!not) { | |
4993 | fail = 0; | |
b9b0c831 NK |
4994 | |
4995 | if (entry) | |
4996 | continue; | |
4997 | if (add_hash_entry(hash, rec->ip) < 0) | |
4998 | goto out; | |
c7c6b1fe | 4999 | } else { |
b9b0c831 NK |
5000 | if (entry) { |
5001 | free_hash_entry(hash, entry); | |
c7c6b1fe LZ |
5002 | fail = 0; |
5003 | } | |
5004 | } | |
ea4e2bc4 | 5005 | } |
265c831c | 5006 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 5007 | out: |
52baf119 | 5008 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 5009 | |
c7c6b1fe LZ |
5010 | if (fail) |
5011 | return -EINVAL; | |
5012 | ||
c7c6b1fe | 5013 | return 0; |
ea4e2bc4 SR |
5014 | } |
5015 | ||
5016 | static ssize_t | |
5017 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
5018 | size_t cnt, loff_t *ppos) | |
5019 | { | |
6a10108b | 5020 | ssize_t read, ret = 0; |
faf982a6 | 5021 | struct ftrace_graph_data *fgd = file->private_data; |
e704eff3 | 5022 | struct trace_parser *parser; |
ea4e2bc4 | 5023 | |
c7c6b1fe | 5024 | if (!cnt) |
ea4e2bc4 SR |
5025 | return 0; |
5026 | ||
ae98d27a SRV |
5027 | /* Read mode uses seq functions */ |
5028 | if (file->f_mode & FMODE_READ) { | |
5029 | struct seq_file *m = file->private_data; | |
5030 | fgd = m->private; | |
5031 | } | |
5032 | ||
e704eff3 | 5033 | parser = &fgd->parser; |
ea4e2bc4 | 5034 | |
e704eff3 | 5035 | read = trace_get_user(parser, ubuf, cnt, ppos); |
689fd8b6 | 5036 | |
e704eff3 SRV |
5037 | if (read >= 0 && trace_parser_loaded(parser) && |
5038 | !trace_parser_cont(parser)) { | |
6a10108b | 5039 | |
b9b0c831 | 5040 | ret = ftrace_graph_set_hash(fgd->new_hash, |
e704eff3 SRV |
5041 | parser->buffer); |
5042 | trace_parser_clear(parser); | |
ea4e2bc4 | 5043 | } |
ea4e2bc4 | 5044 | |
6a10108b NK |
5045 | if (!ret) |
5046 | ret = read; | |
1eb90f13 | 5047 | |
ea4e2bc4 SR |
5048 | return ret; |
5049 | } | |
5050 | ||
5051 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
5052 | .open = ftrace_graph_open, |
5053 | .read = seq_read, | |
5054 | .write = ftrace_graph_write, | |
098c879e | 5055 | .llseek = tracing_lseek, |
87827111 | 5056 | .release = ftrace_graph_release, |
ea4e2bc4 | 5057 | }; |
29ad23b0 NK |
5058 | |
5059 | static const struct file_operations ftrace_graph_notrace_fops = { | |
5060 | .open = ftrace_graph_notrace_open, | |
5061 | .read = seq_read, | |
5062 | .write = ftrace_graph_write, | |
098c879e | 5063 | .llseek = tracing_lseek, |
29ad23b0 NK |
5064 | .release = ftrace_graph_release, |
5065 | }; | |
ea4e2bc4 SR |
5066 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
5067 | ||
591dffda SRRH |
5068 | void ftrace_create_filter_files(struct ftrace_ops *ops, |
5069 | struct dentry *parent) | |
5070 | { | |
5071 | ||
5072 | trace_create_file("set_ftrace_filter", 0644, parent, | |
5073 | ops, &ftrace_filter_fops); | |
5074 | ||
5075 | trace_create_file("set_ftrace_notrace", 0644, parent, | |
5076 | ops, &ftrace_notrace_fops); | |
5077 | } | |
5078 | ||
5079 | /* | |
5080 | * The name "destroy_filter_files" is really a misnomer. Although | |
5081 | * in the future, it may actualy delete the files, but this is | |
5082 | * really intended to make sure the ops passed in are disabled | |
5083 | * and that when this function returns, the caller is free to | |
5084 | * free the ops. | |
5085 | * | |
5086 | * The "destroy" name is only to match the "create" name that this | |
5087 | * should be paired with. | |
5088 | */ | |
5089 | void ftrace_destroy_filter_files(struct ftrace_ops *ops) | |
5090 | { | |
5091 | mutex_lock(&ftrace_lock); | |
5092 | if (ops->flags & FTRACE_OPS_FL_ENABLED) | |
5093 | ftrace_shutdown(ops, 0); | |
5094 | ops->flags |= FTRACE_OPS_FL_DELETED; | |
5095 | mutex_unlock(&ftrace_lock); | |
5096 | } | |
5097 | ||
8434dc93 | 5098 | static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer) |
5072c59f | 5099 | { |
5072c59f | 5100 | |
5452af66 FW |
5101 | trace_create_file("available_filter_functions", 0444, |
5102 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 5103 | |
647bcd03 SR |
5104 | trace_create_file("enabled_functions", 0444, |
5105 | d_tracer, NULL, &ftrace_enabled_fops); | |
5106 | ||
591dffda | 5107 | ftrace_create_filter_files(&global_ops, d_tracer); |
ad90c0e3 | 5108 | |
ea4e2bc4 | 5109 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5452af66 | 5110 | trace_create_file("set_graph_function", 0444, d_tracer, |
ea4e2bc4 SR |
5111 | NULL, |
5112 | &ftrace_graph_fops); | |
29ad23b0 NK |
5113 | trace_create_file("set_graph_notrace", 0444, d_tracer, |
5114 | NULL, | |
5115 | &ftrace_graph_notrace_fops); | |
ea4e2bc4 SR |
5116 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
5117 | ||
5072c59f SR |
5118 | return 0; |
5119 | } | |
5120 | ||
9fd49328 | 5121 | static int ftrace_cmp_ips(const void *a, const void *b) |
68950619 | 5122 | { |
9fd49328 SR |
5123 | const unsigned long *ipa = a; |
5124 | const unsigned long *ipb = b; | |
68950619 | 5125 | |
9fd49328 SR |
5126 | if (*ipa > *ipb) |
5127 | return 1; | |
5128 | if (*ipa < *ipb) | |
5129 | return -1; | |
5130 | return 0; | |
5131 | } | |
5132 | ||
5cb084bb | 5133 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 5134 | unsigned long *start, |
68bf21aa SR |
5135 | unsigned long *end) |
5136 | { | |
706c81f8 | 5137 | struct ftrace_page *start_pg; |
a7900875 | 5138 | struct ftrace_page *pg; |
706c81f8 | 5139 | struct dyn_ftrace *rec; |
a7900875 | 5140 | unsigned long count; |
68bf21aa SR |
5141 | unsigned long *p; |
5142 | unsigned long addr; | |
4376cac6 | 5143 | unsigned long flags = 0; /* Shut up gcc */ |
a7900875 SR |
5144 | int ret = -ENOMEM; |
5145 | ||
5146 | count = end - start; | |
5147 | ||
5148 | if (!count) | |
5149 | return 0; | |
5150 | ||
9fd49328 | 5151 | sort(start, count, sizeof(*start), |
6db02903 | 5152 | ftrace_cmp_ips, NULL); |
9fd49328 | 5153 | |
706c81f8 SR |
5154 | start_pg = ftrace_allocate_pages(count); |
5155 | if (!start_pg) | |
a7900875 | 5156 | return -ENOMEM; |
68bf21aa | 5157 | |
e6ea44e9 | 5158 | mutex_lock(&ftrace_lock); |
a7900875 | 5159 | |
32082309 SR |
5160 | /* |
5161 | * Core and each module needs their own pages, as | |
5162 | * modules will free them when they are removed. | |
5163 | * Force a new page to be allocated for modules. | |
5164 | */ | |
a7900875 SR |
5165 | if (!mod) { |
5166 | WARN_ON(ftrace_pages || ftrace_pages_start); | |
5167 | /* First initialization */ | |
706c81f8 | 5168 | ftrace_pages = ftrace_pages_start = start_pg; |
a7900875 | 5169 | } else { |
32082309 | 5170 | if (!ftrace_pages) |
a7900875 | 5171 | goto out; |
32082309 | 5172 | |
a7900875 SR |
5173 | if (WARN_ON(ftrace_pages->next)) { |
5174 | /* Hmm, we have free pages? */ | |
5175 | while (ftrace_pages->next) | |
5176 | ftrace_pages = ftrace_pages->next; | |
32082309 | 5177 | } |
a7900875 | 5178 | |
706c81f8 | 5179 | ftrace_pages->next = start_pg; |
32082309 SR |
5180 | } |
5181 | ||
68bf21aa | 5182 | p = start; |
706c81f8 | 5183 | pg = start_pg; |
68bf21aa SR |
5184 | while (p < end) { |
5185 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
5186 | /* |
5187 | * Some architecture linkers will pad between | |
5188 | * the different mcount_loc sections of different | |
5189 | * object files to satisfy alignments. | |
5190 | * Skip any NULL pointers. | |
5191 | */ | |
5192 | if (!addr) | |
5193 | continue; | |
706c81f8 SR |
5194 | |
5195 | if (pg->index == pg->size) { | |
5196 | /* We should have allocated enough */ | |
5197 | if (WARN_ON(!pg->next)) | |
5198 | break; | |
5199 | pg = pg->next; | |
5200 | } | |
5201 | ||
5202 | rec = &pg->records[pg->index++]; | |
5203 | rec->ip = addr; | |
68bf21aa SR |
5204 | } |
5205 | ||
706c81f8 SR |
5206 | /* We should have used all pages */ |
5207 | WARN_ON(pg->next); | |
5208 | ||
5209 | /* Assign the last page to ftrace_pages */ | |
5210 | ftrace_pages = pg; | |
5211 | ||
a4f18ed1 | 5212 | /* |
4376cac6 SR |
5213 | * We only need to disable interrupts on start up |
5214 | * because we are modifying code that an interrupt | |
5215 | * may execute, and the modification is not atomic. | |
5216 | * But for modules, nothing runs the code we modify | |
5217 | * until we are finished with it, and there's no | |
5218 | * reason to cause large interrupt latencies while we do it. | |
a4f18ed1 | 5219 | */ |
4376cac6 SR |
5220 | if (!mod) |
5221 | local_irq_save(flags); | |
1dc43cf0 | 5222 | ftrace_update_code(mod, start_pg); |
4376cac6 SR |
5223 | if (!mod) |
5224 | local_irq_restore(flags); | |
a7900875 SR |
5225 | ret = 0; |
5226 | out: | |
e6ea44e9 | 5227 | mutex_unlock(&ftrace_lock); |
68bf21aa | 5228 | |
a7900875 | 5229 | return ret; |
68bf21aa SR |
5230 | } |
5231 | ||
93eb677d | 5232 | #ifdef CONFIG_MODULES |
32082309 SR |
5233 | |
5234 | #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next) | |
5235 | ||
b7ffffbb SRRH |
5236 | static int referenced_filters(struct dyn_ftrace *rec) |
5237 | { | |
5238 | struct ftrace_ops *ops; | |
5239 | int cnt = 0; | |
5240 | ||
5241 | for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) { | |
5242 | if (ops_references_rec(ops, rec)) | |
5243 | cnt++; | |
5244 | } | |
5245 | ||
5246 | return cnt; | |
5247 | } | |
5248 | ||
e7247a15 | 5249 | void ftrace_release_mod(struct module *mod) |
93eb677d SR |
5250 | { |
5251 | struct dyn_ftrace *rec; | |
32082309 | 5252 | struct ftrace_page **last_pg; |
93eb677d | 5253 | struct ftrace_page *pg; |
a7900875 | 5254 | int order; |
93eb677d | 5255 | |
45a4a237 SR |
5256 | mutex_lock(&ftrace_lock); |
5257 | ||
e7247a15 | 5258 | if (ftrace_disabled) |
45a4a237 | 5259 | goto out_unlock; |
93eb677d | 5260 | |
32082309 SR |
5261 | /* |
5262 | * Each module has its own ftrace_pages, remove | |
5263 | * them from the list. | |
5264 | */ | |
5265 | last_pg = &ftrace_pages_start; | |
5266 | for (pg = ftrace_pages_start; pg; pg = *last_pg) { | |
5267 | rec = &pg->records[0]; | |
e7247a15 | 5268 | if (within_module_core(rec->ip, mod)) { |
93eb677d | 5269 | /* |
32082309 SR |
5270 | * As core pages are first, the first |
5271 | * page should never be a module page. | |
93eb677d | 5272 | */ |
32082309 SR |
5273 | if (WARN_ON(pg == ftrace_pages_start)) |
5274 | goto out_unlock; | |
5275 | ||
5276 | /* Check if we are deleting the last page */ | |
5277 | if (pg == ftrace_pages) | |
5278 | ftrace_pages = next_to_ftrace_page(last_pg); | |
5279 | ||
5280 | *last_pg = pg->next; | |
a7900875 SR |
5281 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
5282 | free_pages((unsigned long)pg->records, order); | |
5283 | kfree(pg); | |
32082309 SR |
5284 | } else |
5285 | last_pg = &pg->next; | |
5286 | } | |
45a4a237 | 5287 | out_unlock: |
93eb677d SR |
5288 | mutex_unlock(&ftrace_lock); |
5289 | } | |
5290 | ||
7dcd182b | 5291 | void ftrace_module_enable(struct module *mod) |
b7ffffbb SRRH |
5292 | { |
5293 | struct dyn_ftrace *rec; | |
5294 | struct ftrace_page *pg; | |
5295 | ||
5296 | mutex_lock(&ftrace_lock); | |
5297 | ||
5298 | if (ftrace_disabled) | |
5299 | goto out_unlock; | |
5300 | ||
5301 | /* | |
5302 | * If the tracing is enabled, go ahead and enable the record. | |
5303 | * | |
5304 | * The reason not to enable the record immediatelly is the | |
5305 | * inherent check of ftrace_make_nop/ftrace_make_call for | |
5306 | * correct previous instructions. Making first the NOP | |
5307 | * conversion puts the module to the correct state, thus | |
5308 | * passing the ftrace_make_call check. | |
5309 | * | |
5310 | * We also delay this to after the module code already set the | |
5311 | * text to read-only, as we now need to set it back to read-write | |
5312 | * so that we can modify the text. | |
5313 | */ | |
5314 | if (ftrace_start_up) | |
5315 | ftrace_arch_code_modify_prepare(); | |
5316 | ||
5317 | do_for_each_ftrace_rec(pg, rec) { | |
5318 | int cnt; | |
5319 | /* | |
5320 | * do_for_each_ftrace_rec() is a double loop. | |
5321 | * module text shares the pg. If a record is | |
5322 | * not part of this module, then skip this pg, | |
5323 | * which the "break" will do. | |
5324 | */ | |
5325 | if (!within_module_core(rec->ip, mod)) | |
5326 | break; | |
5327 | ||
5328 | cnt = 0; | |
5329 | ||
5330 | /* | |
5331 | * When adding a module, we need to check if tracers are | |
5332 | * currently enabled and if they are, and can trace this record, | |
5333 | * we need to enable the module functions as well as update the | |
5334 | * reference counts for those function records. | |
5335 | */ | |
5336 | if (ftrace_start_up) | |
5337 | cnt += referenced_filters(rec); | |
5338 | ||
5339 | /* This clears FTRACE_FL_DISABLED */ | |
5340 | rec->flags = cnt; | |
5341 | ||
5342 | if (ftrace_start_up && cnt) { | |
5343 | int failed = __ftrace_replace_code(rec, 1); | |
5344 | if (failed) { | |
5345 | ftrace_bug(failed, rec); | |
5346 | goto out_loop; | |
5347 | } | |
5348 | } | |
5349 | ||
5350 | } while_for_each_ftrace_rec(); | |
5351 | ||
5352 | out_loop: | |
5353 | if (ftrace_start_up) | |
5354 | ftrace_arch_code_modify_post_process(); | |
5355 | ||
5356 | out_unlock: | |
5357 | mutex_unlock(&ftrace_lock); | |
5358 | } | |
5359 | ||
b6b71f66 | 5360 | void ftrace_module_init(struct module *mod) |
90d595fe | 5361 | { |
97e9b4fc | 5362 | if (ftrace_disabled || !mod->num_ftrace_callsites) |
fed1939c | 5363 | return; |
90d595fe | 5364 | |
97e9b4fc SRRH |
5365 | ftrace_process_locs(mod, mod->ftrace_callsites, |
5366 | mod->ftrace_callsites + mod->num_ftrace_callsites); | |
8c189ea6 | 5367 | } |
93eb677d SR |
5368 | #endif /* CONFIG_MODULES */ |
5369 | ||
b80f0f6c | 5370 | void __init ftrace_free_init_mem(void) |
42c269c8 | 5371 | { |
b80f0f6c SRV |
5372 | unsigned long start = (unsigned long)(&__init_begin); |
5373 | unsigned long end = (unsigned long)(&__init_end); | |
42c269c8 SRV |
5374 | struct ftrace_page **last_pg = &ftrace_pages_start; |
5375 | struct ftrace_page *pg; | |
5376 | struct dyn_ftrace *rec; | |
5377 | struct dyn_ftrace key; | |
5378 | int order; | |
5379 | ||
5380 | key.ip = start; | |
5381 | key.flags = end; /* overload flags, as it is unsigned long */ | |
5382 | ||
5383 | mutex_lock(&ftrace_lock); | |
5384 | ||
5385 | for (pg = ftrace_pages_start; pg; last_pg = &pg->next, pg = *last_pg) { | |
5386 | if (end < pg->records[0].ip || | |
5387 | start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) | |
5388 | continue; | |
5389 | again: | |
5390 | rec = bsearch(&key, pg->records, pg->index, | |
5391 | sizeof(struct dyn_ftrace), | |
5392 | ftrace_cmp_recs); | |
5393 | if (!rec) | |
5394 | continue; | |
5395 | pg->index--; | |
5396 | if (!pg->index) { | |
5397 | *last_pg = pg->next; | |
5398 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); | |
5399 | free_pages((unsigned long)pg->records, order); | |
5400 | kfree(pg); | |
5401 | pg = container_of(last_pg, struct ftrace_page, next); | |
5402 | if (!(*last_pg)) | |
5403 | ftrace_pages = pg; | |
5404 | continue; | |
5405 | } | |
5406 | memmove(rec, rec + 1, | |
5407 | (pg->index - (rec - pg->records)) * sizeof(*rec)); | |
5408 | /* More than one function may be in this block */ | |
5409 | goto again; | |
5410 | } | |
5411 | mutex_unlock(&ftrace_lock); | |
5412 | } | |
5413 | ||
68bf21aa SR |
5414 | void __init ftrace_init(void) |
5415 | { | |
1dc43cf0 JS |
5416 | extern unsigned long __start_mcount_loc[]; |
5417 | extern unsigned long __stop_mcount_loc[]; | |
3a36cb11 | 5418 | unsigned long count, flags; |
68bf21aa SR |
5419 | int ret; |
5420 | ||
68bf21aa | 5421 | local_irq_save(flags); |
3a36cb11 | 5422 | ret = ftrace_dyn_arch_init(); |
68bf21aa | 5423 | local_irq_restore(flags); |
af64a7cb | 5424 | if (ret) |
68bf21aa SR |
5425 | goto failed; |
5426 | ||
5427 | count = __stop_mcount_loc - __start_mcount_loc; | |
c867ccd8 JS |
5428 | if (!count) { |
5429 | pr_info("ftrace: No functions to be traced?\n"); | |
68bf21aa | 5430 | goto failed; |
c867ccd8 JS |
5431 | } |
5432 | ||
5433 | pr_info("ftrace: allocating %ld entries in %ld pages\n", | |
5434 | count, count / ENTRIES_PER_PAGE + 1); | |
68bf21aa SR |
5435 | |
5436 | last_ftrace_enabled = ftrace_enabled = 1; | |
5437 | ||
5cb084bb | 5438 | ret = ftrace_process_locs(NULL, |
31e88909 | 5439 | __start_mcount_loc, |
68bf21aa SR |
5440 | __stop_mcount_loc); |
5441 | ||
2af15d6a SR |
5442 | set_ftrace_early_filters(); |
5443 | ||
68bf21aa SR |
5444 | return; |
5445 | failed: | |
5446 | ftrace_disabled = 1; | |
5447 | } | |
68bf21aa | 5448 | |
f3bea491 SRRH |
5449 | /* Do nothing if arch does not support this */ |
5450 | void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops) | |
5451 | { | |
5452 | } | |
5453 | ||
5454 | static void ftrace_update_trampoline(struct ftrace_ops *ops) | |
5455 | { | |
f3bea491 SRRH |
5456 | arch_ftrace_update_trampoline(ops); |
5457 | } | |
5458 | ||
3d083395 | 5459 | #else |
0b6e4d56 | 5460 | |
2b499381 | 5461 | static struct ftrace_ops global_ops = { |
bd69c30b | 5462 | .func = ftrace_stub, |
e3eea140 SRRH |
5463 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | |
5464 | FTRACE_OPS_FL_INITIALIZED | | |
5465 | FTRACE_OPS_FL_PID, | |
bd69c30b SR |
5466 | }; |
5467 | ||
0b6e4d56 FW |
5468 | static int __init ftrace_nodyn_init(void) |
5469 | { | |
5470 | ftrace_enabled = 1; | |
5471 | return 0; | |
5472 | } | |
6f415672 | 5473 | core_initcall(ftrace_nodyn_init); |
0b6e4d56 | 5474 | |
8434dc93 | 5475 | static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; } |
df4fc315 | 5476 | static inline void ftrace_startup_enable(int command) { } |
e1effa01 | 5477 | static inline void ftrace_startup_all(int command) { } |
5a45cfe1 | 5478 | /* Keep as macros so we do not need to define the commands */ |
8a56d776 SRRH |
5479 | # define ftrace_startup(ops, command) \ |
5480 | ({ \ | |
5481 | int ___ret = __register_ftrace_function(ops); \ | |
5482 | if (!___ret) \ | |
5483 | (ops)->flags |= FTRACE_OPS_FL_ENABLED; \ | |
5484 | ___ret; \ | |
3b6cfdb1 | 5485 | }) |
1fcc1553 SRRH |
5486 | # define ftrace_shutdown(ops, command) \ |
5487 | ({ \ | |
5488 | int ___ret = __unregister_ftrace_function(ops); \ | |
5489 | if (!___ret) \ | |
5490 | (ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \ | |
5491 | ___ret; \ | |
5492 | }) | |
8a56d776 | 5493 | |
c7aafc54 IM |
5494 | # define ftrace_startup_sysctl() do { } while (0) |
5495 | # define ftrace_shutdown_sysctl() do { } while (0) | |
b848914c SR |
5496 | |
5497 | static inline int | |
195a8afc | 5498 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs) |
b848914c SR |
5499 | { |
5500 | return 1; | |
5501 | } | |
5502 | ||
f3bea491 SRRH |
5503 | static void ftrace_update_trampoline(struct ftrace_ops *ops) |
5504 | { | |
5505 | } | |
5506 | ||
3d083395 SR |
5507 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
5508 | ||
4104d326 SRRH |
5509 | __init void ftrace_init_global_array_ops(struct trace_array *tr) |
5510 | { | |
5511 | tr->ops = &global_ops; | |
5512 | tr->ops->private = tr; | |
5513 | } | |
5514 | ||
5515 | void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func) | |
5516 | { | |
5517 | /* If we filter on pids, update to use the pid function */ | |
5518 | if (tr->flags & TRACE_ARRAY_FL_GLOBAL) { | |
5519 | if (WARN_ON(tr->ops->func != ftrace_stub)) | |
5520 | printk("ftrace ops had %pS for function\n", | |
5521 | tr->ops->func); | |
4104d326 SRRH |
5522 | } |
5523 | tr->ops->func = func; | |
5524 | tr->ops->private = tr; | |
5525 | } | |
5526 | ||
5527 | void ftrace_reset_array_ops(struct trace_array *tr) | |
5528 | { | |
5529 | tr->ops->func = ftrace_stub; | |
5530 | } | |
5531 | ||
2f5f6ad9 SR |
5532 | static inline void |
5533 | __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 5534 | struct ftrace_ops *ignored, struct pt_regs *regs) |
b848914c | 5535 | { |
cdbe61bf | 5536 | struct ftrace_ops *op; |
edc15caf | 5537 | int bit; |
b848914c | 5538 | |
edc15caf SR |
5539 | bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX); |
5540 | if (bit < 0) | |
5541 | return; | |
b1cff0ad | 5542 | |
cdbe61bf SR |
5543 | /* |
5544 | * Some of the ops may be dynamically allocated, | |
5545 | * they must be freed after a synchronize_sched(). | |
5546 | */ | |
5547 | preempt_disable_notrace(); | |
ba27f2bc | 5548 | |
0a016409 | 5549 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
ba27f2bc SRRH |
5550 | /* |
5551 | * Check the following for each ops before calling their func: | |
5552 | * if RCU flag is set, then rcu_is_watching() must be true | |
5553 | * if PER_CPU is set, then ftrace_function_local_disable() | |
5554 | * must be false | |
5555 | * Otherwise test if the ip matches the ops filter | |
5556 | * | |
5557 | * If any of the above fails then the op->func() is not executed. | |
5558 | */ | |
5559 | if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) && | |
5560 | (!(op->flags & FTRACE_OPS_FL_PER_CPU) || | |
5561 | !ftrace_function_local_disabled(op)) && | |
5562 | ftrace_ops_test(op, ip, regs)) { | |
5563 | ||
1d48d596 SRRH |
5564 | if (FTRACE_WARN_ON(!op->func)) { |
5565 | pr_warn("op=%p %pS\n", op, op); | |
4104d326 SRRH |
5566 | goto out; |
5567 | } | |
a1e2e31d | 5568 | op->func(ip, parent_ip, op, regs); |
4104d326 | 5569 | } |
0a016409 | 5570 | } while_for_each_ftrace_op(op); |
4104d326 | 5571 | out: |
cdbe61bf | 5572 | preempt_enable_notrace(); |
edc15caf | 5573 | trace_clear_recursion(bit); |
b848914c SR |
5574 | } |
5575 | ||
2f5f6ad9 SR |
5576 | /* |
5577 | * Some archs only support passing ip and parent_ip. Even though | |
5578 | * the list function ignores the op parameter, we do not want any | |
5579 | * C side effects, where a function is called without the caller | |
5580 | * sending a third parameter. | |
a1e2e31d SR |
5581 | * Archs are to support both the regs and ftrace_ops at the same time. |
5582 | * If they support ftrace_ops, it is assumed they support regs. | |
5583 | * If call backs want to use regs, they must either check for regs | |
06aeaaea MH |
5584 | * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS. |
5585 | * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved. | |
a1e2e31d | 5586 | * An architecture can pass partial regs with ftrace_ops and still |
b8ec330a | 5587 | * set the ARCH_SUPPORTS_FTRACE_OPS. |
2f5f6ad9 SR |
5588 | */ |
5589 | #if ARCH_SUPPORTS_FTRACE_OPS | |
5590 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 5591 | struct ftrace_ops *op, struct pt_regs *regs) |
2f5f6ad9 | 5592 | { |
a1e2e31d | 5593 | __ftrace_ops_list_func(ip, parent_ip, NULL, regs); |
2f5f6ad9 SR |
5594 | } |
5595 | #else | |
5596 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip) | |
5597 | { | |
a1e2e31d | 5598 | __ftrace_ops_list_func(ip, parent_ip, NULL, NULL); |
2f5f6ad9 SR |
5599 | } |
5600 | #endif | |
5601 | ||
f1ff6348 SRRH |
5602 | /* |
5603 | * If there's only one function registered but it does not support | |
c68c0fa2 SRRH |
5604 | * recursion, needs RCU protection and/or requires per cpu handling, then |
5605 | * this function will be called by the mcount trampoline. | |
f1ff6348 | 5606 | */ |
c68c0fa2 | 5607 | static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip, |
f1ff6348 SRRH |
5608 | struct ftrace_ops *op, struct pt_regs *regs) |
5609 | { | |
5610 | int bit; | |
5611 | ||
c68c0fa2 SRRH |
5612 | if ((op->flags & FTRACE_OPS_FL_RCU) && !rcu_is_watching()) |
5613 | return; | |
5614 | ||
f1ff6348 SRRH |
5615 | bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX); |
5616 | if (bit < 0) | |
5617 | return; | |
5618 | ||
c68c0fa2 | 5619 | preempt_disable_notrace(); |
f1ff6348 | 5620 | |
c68c0fa2 SRRH |
5621 | if (!(op->flags & FTRACE_OPS_FL_PER_CPU) || |
5622 | !ftrace_function_local_disabled(op)) { | |
5623 | op->func(ip, parent_ip, op, regs); | |
5624 | } | |
5625 | ||
5626 | preempt_enable_notrace(); | |
f1ff6348 SRRH |
5627 | trace_clear_recursion(bit); |
5628 | } | |
5629 | ||
87354059 SRRH |
5630 | /** |
5631 | * ftrace_ops_get_func - get the function a trampoline should call | |
5632 | * @ops: the ops to get the function for | |
5633 | * | |
5634 | * Normally the mcount trampoline will call the ops->func, but there | |
5635 | * are times that it should not. For example, if the ops does not | |
5636 | * have its own recursion protection, then it should call the | |
3a150df9 | 5637 | * ftrace_ops_assist_func() instead. |
87354059 SRRH |
5638 | * |
5639 | * Returns the function that the trampoline should call for @ops. | |
5640 | */ | |
5641 | ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops) | |
5642 | { | |
87354059 | 5643 | /* |
c68c0fa2 SRRH |
5644 | * If the function does not handle recursion, needs to be RCU safe, |
5645 | * or does per cpu logic, then we need to call the assist handler. | |
87354059 | 5646 | */ |
c68c0fa2 SRRH |
5647 | if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE) || |
5648 | ops->flags & (FTRACE_OPS_FL_RCU | FTRACE_OPS_FL_PER_CPU)) | |
5649 | return ftrace_ops_assist_func; | |
87354059 SRRH |
5650 | |
5651 | return ops->func; | |
5652 | } | |
5653 | ||
345ddcc8 SRRH |
5654 | static void |
5655 | ftrace_filter_pid_sched_switch_probe(void *data, bool preempt, | |
5656 | struct task_struct *prev, struct task_struct *next) | |
978f3a45 | 5657 | { |
345ddcc8 SRRH |
5658 | struct trace_array *tr = data; |
5659 | struct trace_pid_list *pid_list; | |
978f3a45 | 5660 | |
345ddcc8 | 5661 | pid_list = rcu_dereference_sched(tr->function_pids); |
e32d8956 | 5662 | |
345ddcc8 SRRH |
5663 | this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid, |
5664 | trace_ignore_this_task(pid_list, next)); | |
978f3a45 SR |
5665 | } |
5666 | ||
1e10486f NK |
5667 | static void |
5668 | ftrace_pid_follow_sched_process_fork(void *data, | |
5669 | struct task_struct *self, | |
5670 | struct task_struct *task) | |
5671 | { | |
5672 | struct trace_pid_list *pid_list; | |
5673 | struct trace_array *tr = data; | |
5674 | ||
5675 | pid_list = rcu_dereference_sched(tr->function_pids); | |
5676 | trace_filter_add_remove_task(pid_list, self, task); | |
5677 | } | |
5678 | ||
5679 | static void | |
5680 | ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task) | |
5681 | { | |
5682 | struct trace_pid_list *pid_list; | |
5683 | struct trace_array *tr = data; | |
5684 | ||
5685 | pid_list = rcu_dereference_sched(tr->function_pids); | |
5686 | trace_filter_add_remove_task(pid_list, NULL, task); | |
5687 | } | |
5688 | ||
5689 | void ftrace_pid_follow_fork(struct trace_array *tr, bool enable) | |
5690 | { | |
5691 | if (enable) { | |
5692 | register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, | |
5693 | tr); | |
5694 | register_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit, | |
5695 | tr); | |
5696 | } else { | |
5697 | unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork, | |
5698 | tr); | |
5699 | unregister_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit, | |
5700 | tr); | |
5701 | } | |
5702 | } | |
5703 | ||
345ddcc8 | 5704 | static void clear_ftrace_pids(struct trace_array *tr) |
e32d8956 | 5705 | { |
345ddcc8 SRRH |
5706 | struct trace_pid_list *pid_list; |
5707 | int cpu; | |
e32d8956 | 5708 | |
345ddcc8 SRRH |
5709 | pid_list = rcu_dereference_protected(tr->function_pids, |
5710 | lockdep_is_held(&ftrace_lock)); | |
5711 | if (!pid_list) | |
5712 | return; | |
229c4ef8 | 5713 | |
345ddcc8 | 5714 | unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr); |
e32d8956 | 5715 | |
345ddcc8 SRRH |
5716 | for_each_possible_cpu(cpu) |
5717 | per_cpu_ptr(tr->trace_buffer.data, cpu)->ftrace_ignore_pid = false; | |
978f3a45 | 5718 | |
345ddcc8 | 5719 | rcu_assign_pointer(tr->function_pids, NULL); |
978f3a45 | 5720 | |
345ddcc8 SRRH |
5721 | /* Wait till all users are no longer using pid filtering */ |
5722 | synchronize_sched(); | |
e32d8956 | 5723 | |
345ddcc8 | 5724 | trace_free_pid_list(pid_list); |
e32d8956 SR |
5725 | } |
5726 | ||
345ddcc8 | 5727 | static void ftrace_pid_reset(struct trace_array *tr) |
df4fc315 | 5728 | { |
756d17ee | 5729 | mutex_lock(&ftrace_lock); |
345ddcc8 | 5730 | clear_ftrace_pids(tr); |
978f3a45 | 5731 | |
756d17ee | 5732 | ftrace_update_pid_func(); |
e1effa01 | 5733 | ftrace_startup_all(0); |
756d17ee | 5734 | |
5735 | mutex_unlock(&ftrace_lock); | |
756d17ee | 5736 | } |
5737 | ||
345ddcc8 SRRH |
5738 | /* Greater than any max PID */ |
5739 | #define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1) | |
df4fc315 | 5740 | |
756d17ee | 5741 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
345ddcc8 | 5742 | __acquires(RCU) |
756d17ee | 5743 | { |
345ddcc8 SRRH |
5744 | struct trace_pid_list *pid_list; |
5745 | struct trace_array *tr = m->private; | |
5746 | ||
756d17ee | 5747 | mutex_lock(&ftrace_lock); |
345ddcc8 SRRH |
5748 | rcu_read_lock_sched(); |
5749 | ||
5750 | pid_list = rcu_dereference_sched(tr->function_pids); | |
756d17ee | 5751 | |
345ddcc8 SRRH |
5752 | if (!pid_list) |
5753 | return !(*pos) ? FTRACE_NO_PIDS : NULL; | |
756d17ee | 5754 | |
345ddcc8 | 5755 | return trace_pid_start(pid_list, pos); |
756d17ee | 5756 | } |
5757 | ||
5758 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
5759 | { | |
345ddcc8 SRRH |
5760 | struct trace_array *tr = m->private; |
5761 | struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids); | |
5762 | ||
5763 | if (v == FTRACE_NO_PIDS) | |
756d17ee | 5764 | return NULL; |
5765 | ||
345ddcc8 | 5766 | return trace_pid_next(pid_list, v, pos); |
756d17ee | 5767 | } |
5768 | ||
5769 | static void fpid_stop(struct seq_file *m, void *p) | |
345ddcc8 | 5770 | __releases(RCU) |
756d17ee | 5771 | { |
345ddcc8 | 5772 | rcu_read_unlock_sched(); |
756d17ee | 5773 | mutex_unlock(&ftrace_lock); |
5774 | } | |
5775 | ||
5776 | static int fpid_show(struct seq_file *m, void *v) | |
5777 | { | |
345ddcc8 | 5778 | if (v == FTRACE_NO_PIDS) { |
fa6f0cc7 | 5779 | seq_puts(m, "no pid\n"); |
756d17ee | 5780 | return 0; |
5781 | } | |
5782 | ||
345ddcc8 | 5783 | return trace_pid_show(m, v); |
756d17ee | 5784 | } |
5785 | ||
5786 | static const struct seq_operations ftrace_pid_sops = { | |
5787 | .start = fpid_start, | |
5788 | .next = fpid_next, | |
5789 | .stop = fpid_stop, | |
5790 | .show = fpid_show, | |
5791 | }; | |
5792 | ||
5793 | static int | |
5794 | ftrace_pid_open(struct inode *inode, struct file *file) | |
5795 | { | |
345ddcc8 SRRH |
5796 | struct trace_array *tr = inode->i_private; |
5797 | struct seq_file *m; | |
756d17ee | 5798 | int ret = 0; |
5799 | ||
345ddcc8 SRRH |
5800 | if (trace_array_get(tr) < 0) |
5801 | return -ENODEV; | |
5802 | ||
756d17ee | 5803 | if ((file->f_mode & FMODE_WRITE) && |
5804 | (file->f_flags & O_TRUNC)) | |
345ddcc8 | 5805 | ftrace_pid_reset(tr); |
756d17ee | 5806 | |
345ddcc8 SRRH |
5807 | ret = seq_open(file, &ftrace_pid_sops); |
5808 | if (ret < 0) { | |
5809 | trace_array_put(tr); | |
5810 | } else { | |
5811 | m = file->private_data; | |
5812 | /* copy tr over to seq ops */ | |
5813 | m->private = tr; | |
5814 | } | |
756d17ee | 5815 | |
5816 | return ret; | |
5817 | } | |
5818 | ||
345ddcc8 SRRH |
5819 | static void ignore_task_cpu(void *data) |
5820 | { | |
5821 | struct trace_array *tr = data; | |
5822 | struct trace_pid_list *pid_list; | |
5823 | ||
5824 | /* | |
5825 | * This function is called by on_each_cpu() while the | |
5826 | * event_mutex is held. | |
5827 | */ | |
5828 | pid_list = rcu_dereference_protected(tr->function_pids, | |
5829 | mutex_is_locked(&ftrace_lock)); | |
5830 | ||
5831 | this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid, | |
5832 | trace_ignore_this_task(pid_list, current)); | |
5833 | } | |
5834 | ||
df4fc315 SR |
5835 | static ssize_t |
5836 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
5837 | size_t cnt, loff_t *ppos) | |
5838 | { | |
345ddcc8 SRRH |
5839 | struct seq_file *m = filp->private_data; |
5840 | struct trace_array *tr = m->private; | |
5841 | struct trace_pid_list *filtered_pids = NULL; | |
5842 | struct trace_pid_list *pid_list; | |
5843 | ssize_t ret; | |
df4fc315 | 5844 | |
345ddcc8 SRRH |
5845 | if (!cnt) |
5846 | return 0; | |
5847 | ||
5848 | mutex_lock(&ftrace_lock); | |
5849 | ||
5850 | filtered_pids = rcu_dereference_protected(tr->function_pids, | |
5851 | lockdep_is_held(&ftrace_lock)); | |
5852 | ||
5853 | ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt); | |
5854 | if (ret < 0) | |
5855 | goto out; | |
df4fc315 | 5856 | |
345ddcc8 | 5857 | rcu_assign_pointer(tr->function_pids, pid_list); |
df4fc315 | 5858 | |
345ddcc8 SRRH |
5859 | if (filtered_pids) { |
5860 | synchronize_sched(); | |
5861 | trace_free_pid_list(filtered_pids); | |
5862 | } else if (pid_list) { | |
5863 | /* Register a probe to set whether to ignore the tracing of a task */ | |
5864 | register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr); | |
5865 | } | |
df4fc315 | 5866 | |
756d17ee | 5867 | /* |
345ddcc8 SRRH |
5868 | * Ignoring of pids is done at task switch. But we have to |
5869 | * check for those tasks that are currently running. | |
5870 | * Always do this in case a pid was appended or removed. | |
756d17ee | 5871 | */ |
345ddcc8 | 5872 | on_each_cpu(ignore_task_cpu, tr, 1); |
756d17ee | 5873 | |
345ddcc8 SRRH |
5874 | ftrace_update_pid_func(); |
5875 | ftrace_startup_all(0); | |
5876 | out: | |
5877 | mutex_unlock(&ftrace_lock); | |
df4fc315 | 5878 | |
345ddcc8 SRRH |
5879 | if (ret > 0) |
5880 | *ppos += ret; | |
df4fc315 | 5881 | |
345ddcc8 | 5882 | return ret; |
756d17ee | 5883 | } |
df4fc315 | 5884 | |
756d17ee | 5885 | static int |
5886 | ftrace_pid_release(struct inode *inode, struct file *file) | |
5887 | { | |
345ddcc8 | 5888 | struct trace_array *tr = inode->i_private; |
df4fc315 | 5889 | |
345ddcc8 SRRH |
5890 | trace_array_put(tr); |
5891 | ||
5892 | return seq_release(inode, file); | |
df4fc315 SR |
5893 | } |
5894 | ||
5e2336a0 | 5895 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 5896 | .open = ftrace_pid_open, |
5897 | .write = ftrace_pid_write, | |
5898 | .read = seq_read, | |
098c879e | 5899 | .llseek = tracing_lseek, |
756d17ee | 5900 | .release = ftrace_pid_release, |
df4fc315 SR |
5901 | }; |
5902 | ||
345ddcc8 | 5903 | void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer) |
df4fc315 | 5904 | { |
5452af66 | 5905 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
345ddcc8 | 5906 | tr, &ftrace_pid_fops); |
df4fc315 | 5907 | } |
df4fc315 | 5908 | |
501c2375 SRRH |
5909 | void __init ftrace_init_tracefs_toplevel(struct trace_array *tr, |
5910 | struct dentry *d_tracer) | |
5911 | { | |
5912 | /* Only the top level directory has the dyn_tracefs and profile */ | |
5913 | WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL)); | |
5914 | ||
5915 | ftrace_init_dyn_tracefs(d_tracer); | |
5916 | ftrace_profile_tracefs(d_tracer); | |
5917 | } | |
5918 | ||
a2bb6a3d | 5919 | /** |
81adbdc0 | 5920 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
5921 | * |
5922 | * This function should be used by panic code. It stops ftrace | |
5923 | * but in a not so nice way. If you need to simply kill ftrace | |
5924 | * from a non-atomic section, use ftrace_kill. | |
5925 | */ | |
81adbdc0 | 5926 | void ftrace_kill(void) |
a2bb6a3d SR |
5927 | { |
5928 | ftrace_disabled = 1; | |
5929 | ftrace_enabled = 0; | |
a2bb6a3d SR |
5930 | clear_ftrace_function(); |
5931 | } | |
5932 | ||
e0a413f6 SR |
5933 | /** |
5934 | * Test if ftrace is dead or not. | |
5935 | */ | |
5936 | int ftrace_is_dead(void) | |
5937 | { | |
5938 | return ftrace_disabled; | |
5939 | } | |
5940 | ||
16444a8a | 5941 | /** |
3d083395 SR |
5942 | * register_ftrace_function - register a function for profiling |
5943 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 5944 | * |
3d083395 SR |
5945 | * Register a function to be called by all functions in the |
5946 | * kernel. | |
5947 | * | |
5948 | * Note: @ops->func and all the functions it calls must be labeled | |
5949 | * with "notrace", otherwise it will go into a | |
5950 | * recursive loop. | |
16444a8a | 5951 | */ |
3d083395 | 5952 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 5953 | { |
45a4a237 | 5954 | int ret = -1; |
4eebcc81 | 5955 | |
f04f24fb MH |
5956 | ftrace_ops_init(ops); |
5957 | ||
e6ea44e9 | 5958 | mutex_lock(&ftrace_lock); |
e7d3737e | 5959 | |
8a56d776 | 5960 | ret = ftrace_startup(ops, 0); |
b848914c | 5961 | |
e6ea44e9 | 5962 | mutex_unlock(&ftrace_lock); |
8d240dd8 | 5963 | |
b0fc494f | 5964 | return ret; |
3d083395 | 5965 | } |
cdbe61bf | 5966 | EXPORT_SYMBOL_GPL(register_ftrace_function); |
3d083395 SR |
5967 | |
5968 | /** | |
32632920 | 5969 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
5970 | * @ops - ops structure that holds the function to unregister |
5971 | * | |
5972 | * Unregister a function that was added to be called by ftrace profiling. | |
5973 | */ | |
5974 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
5975 | { | |
5976 | int ret; | |
5977 | ||
e6ea44e9 | 5978 | mutex_lock(&ftrace_lock); |
8a56d776 | 5979 | ret = ftrace_shutdown(ops, 0); |
e6ea44e9 | 5980 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
5981 | |
5982 | return ret; | |
5983 | } | |
cdbe61bf | 5984 | EXPORT_SYMBOL_GPL(unregister_ftrace_function); |
b0fc494f | 5985 | |
e309b41d | 5986 | int |
b0fc494f | 5987 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
8d65af78 | 5988 | void __user *buffer, size_t *lenp, |
b0fc494f SR |
5989 | loff_t *ppos) |
5990 | { | |
45a4a237 | 5991 | int ret = -ENODEV; |
4eebcc81 | 5992 | |
e6ea44e9 | 5993 | mutex_lock(&ftrace_lock); |
b0fc494f | 5994 | |
45a4a237 SR |
5995 | if (unlikely(ftrace_disabled)) |
5996 | goto out; | |
5997 | ||
5998 | ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
b0fc494f | 5999 | |
a32c7765 | 6000 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
6001 | goto out; |
6002 | ||
a32c7765 | 6003 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f SR |
6004 | |
6005 | if (ftrace_enabled) { | |
6006 | ||
b0fc494f | 6007 | /* we are starting ftrace again */ |
5000c418 JK |
6008 | if (ftrace_ops_list != &ftrace_list_end) |
6009 | update_ftrace_function(); | |
b0fc494f | 6010 | |
524a3868 SRRH |
6011 | ftrace_startup_sysctl(); |
6012 | ||
b0fc494f SR |
6013 | } else { |
6014 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
6015 | ftrace_trace_function = ftrace_stub; | |
6016 | ||
6017 | ftrace_shutdown_sysctl(); | |
6018 | } | |
6019 | ||
6020 | out: | |
e6ea44e9 | 6021 | mutex_unlock(&ftrace_lock); |
3d083395 | 6022 | return ret; |
16444a8a | 6023 | } |
f17845e5 | 6024 | |
fb52607a | 6025 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 6026 | |
5f151b24 SRRH |
6027 | static struct ftrace_ops graph_ops = { |
6028 | .func = ftrace_stub, | |
6029 | .flags = FTRACE_OPS_FL_RECURSION_SAFE | | |
6030 | FTRACE_OPS_FL_INITIALIZED | | |
e3eea140 | 6031 | FTRACE_OPS_FL_PID | |
5f151b24 SRRH |
6032 | FTRACE_OPS_FL_STUB, |
6033 | #ifdef FTRACE_GRAPH_TRAMP_ADDR | |
6034 | .trampoline = FTRACE_GRAPH_TRAMP_ADDR, | |
aec0be2d | 6035 | /* trampoline_size is only needed for dynamically allocated tramps */ |
5f151b24 SRRH |
6036 | #endif |
6037 | ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash) | |
6038 | }; | |
6039 | ||
55577204 SRRH |
6040 | void ftrace_graph_sleep_time_control(bool enable) |
6041 | { | |
6042 | fgraph_sleep_time = enable; | |
6043 | } | |
6044 | ||
6045 | void ftrace_graph_graph_time_control(bool enable) | |
6046 | { | |
6047 | fgraph_graph_time = enable; | |
6048 | } | |
6049 | ||
e49dc19c SR |
6050 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
6051 | { | |
6052 | return 0; | |
6053 | } | |
6054 | ||
287b6e68 FW |
6055 | /* The callbacks that hook a function */ |
6056 | trace_func_graph_ret_t ftrace_graph_return = | |
6057 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 6058 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
23a8e844 | 6059 | static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
6060 | |
6061 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
6062 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
6063 | { | |
6064 | int i; | |
6065 | int ret = 0; | |
f201ae23 FW |
6066 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; |
6067 | struct task_struct *g, *t; | |
6068 | ||
6069 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
6070 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
6071 | * sizeof(struct ftrace_ret_stack), | |
6072 | GFP_KERNEL); | |
6073 | if (!ret_stack_list[i]) { | |
6074 | start = 0; | |
6075 | end = i; | |
6076 | ret = -ENOMEM; | |
6077 | goto free; | |
6078 | } | |
6079 | } | |
6080 | ||
6112a300 | 6081 | read_lock(&tasklist_lock); |
f201ae23 FW |
6082 | do_each_thread(g, t) { |
6083 | if (start == end) { | |
6084 | ret = -EAGAIN; | |
6085 | goto unlock; | |
6086 | } | |
6087 | ||
6088 | if (t->ret_stack == NULL) { | |
380c4b14 | 6089 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 6090 | atomic_set(&t->trace_overrun, 0); |
26c01624 SR |
6091 | t->curr_ret_stack = -1; |
6092 | /* Make sure the tasks see the -1 first: */ | |
6093 | smp_wmb(); | |
6094 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
6095 | } |
6096 | } while_each_thread(g, t); | |
6097 | ||
6098 | unlock: | |
6112a300 | 6099 | read_unlock(&tasklist_lock); |
f201ae23 FW |
6100 | free: |
6101 | for (i = start; i < end; i++) | |
6102 | kfree(ret_stack_list[i]); | |
6103 | return ret; | |
6104 | } | |
6105 | ||
8aef2d28 | 6106 | static void |
c73464b1 | 6107 | ftrace_graph_probe_sched_switch(void *ignore, bool preempt, |
38516ab5 | 6108 | struct task_struct *prev, struct task_struct *next) |
8aef2d28 SR |
6109 | { |
6110 | unsigned long long timestamp; | |
6111 | int index; | |
6112 | ||
be6f164a SR |
6113 | /* |
6114 | * Does the user want to count the time a function was asleep. | |
6115 | * If so, do not update the time stamps. | |
6116 | */ | |
55577204 | 6117 | if (fgraph_sleep_time) |
be6f164a SR |
6118 | return; |
6119 | ||
8aef2d28 SR |
6120 | timestamp = trace_clock_local(); |
6121 | ||
6122 | prev->ftrace_timestamp = timestamp; | |
6123 | ||
6124 | /* only process tasks that we timestamped */ | |
6125 | if (!next->ftrace_timestamp) | |
6126 | return; | |
6127 | ||
6128 | /* | |
6129 | * Update all the counters in next to make up for the | |
6130 | * time next was sleeping. | |
6131 | */ | |
6132 | timestamp -= next->ftrace_timestamp; | |
6133 | ||
6134 | for (index = next->curr_ret_stack; index >= 0; index--) | |
6135 | next->ret_stack[index].calltime += timestamp; | |
6136 | } | |
6137 | ||
f201ae23 | 6138 | /* Allocate a return stack for each task */ |
fb52607a | 6139 | static int start_graph_tracing(void) |
f201ae23 FW |
6140 | { |
6141 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 6142 | int ret, cpu; |
f201ae23 FW |
6143 | |
6144 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
6145 | sizeof(struct ftrace_ret_stack *), | |
6146 | GFP_KERNEL); | |
6147 | ||
6148 | if (!ret_stack_list) | |
6149 | return -ENOMEM; | |
6150 | ||
5b058bcd | 6151 | /* The cpu_boot init_task->ret_stack will never be freed */ |
179c498a SR |
6152 | for_each_online_cpu(cpu) { |
6153 | if (!idle_task(cpu)->ret_stack) | |
868baf07 | 6154 | ftrace_graph_init_idle_task(idle_task(cpu), cpu); |
179c498a | 6155 | } |
5b058bcd | 6156 | |
f201ae23 FW |
6157 | do { |
6158 | ret = alloc_retstack_tasklist(ret_stack_list); | |
6159 | } while (ret == -EAGAIN); | |
6160 | ||
8aef2d28 | 6161 | if (!ret) { |
38516ab5 | 6162 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
8aef2d28 SR |
6163 | if (ret) |
6164 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
6165 | " probe to kernel_sched_switch\n"); | |
6166 | } | |
6167 | ||
f201ae23 FW |
6168 | kfree(ret_stack_list); |
6169 | return ret; | |
6170 | } | |
6171 | ||
4a2b8dda FW |
6172 | /* |
6173 | * Hibernation protection. | |
6174 | * The state of the current task is too much unstable during | |
6175 | * suspend/restore to disk. We want to protect against that. | |
6176 | */ | |
6177 | static int | |
6178 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
6179 | void *unused) | |
6180 | { | |
6181 | switch (state) { | |
6182 | case PM_HIBERNATION_PREPARE: | |
6183 | pause_graph_tracing(); | |
6184 | break; | |
6185 | ||
6186 | case PM_POST_HIBERNATION: | |
6187 | unpause_graph_tracing(); | |
6188 | break; | |
6189 | } | |
6190 | return NOTIFY_DONE; | |
6191 | } | |
6192 | ||
23a8e844 SRRH |
6193 | static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace) |
6194 | { | |
6195 | if (!ftrace_ops_test(&global_ops, trace->func, NULL)) | |
6196 | return 0; | |
6197 | return __ftrace_graph_entry(trace); | |
6198 | } | |
6199 | ||
6200 | /* | |
6201 | * The function graph tracer should only trace the functions defined | |
6202 | * by set_ftrace_filter and set_ftrace_notrace. If another function | |
6203 | * tracer ops is registered, the graph tracer requires testing the | |
6204 | * function against the global ops, and not just trace any function | |
6205 | * that any ftrace_ops registered. | |
6206 | */ | |
6207 | static void update_function_graph_func(void) | |
6208 | { | |
5f151b24 SRRH |
6209 | struct ftrace_ops *op; |
6210 | bool do_test = false; | |
6211 | ||
6212 | /* | |
6213 | * The graph and global ops share the same set of functions | |
6214 | * to test. If any other ops is on the list, then | |
6215 | * the graph tracing needs to test if its the function | |
6216 | * it should call. | |
6217 | */ | |
6218 | do_for_each_ftrace_op(op, ftrace_ops_list) { | |
6219 | if (op != &global_ops && op != &graph_ops && | |
6220 | op != &ftrace_list_end) { | |
6221 | do_test = true; | |
6222 | /* in double loop, break out with goto */ | |
6223 | goto out; | |
6224 | } | |
6225 | } while_for_each_ftrace_op(op); | |
6226 | out: | |
6227 | if (do_test) | |
23a8e844 | 6228 | ftrace_graph_entry = ftrace_graph_entry_test; |
5f151b24 SRRH |
6229 | else |
6230 | ftrace_graph_entry = __ftrace_graph_entry; | |
23a8e844 SRRH |
6231 | } |
6232 | ||
8275f69f MK |
6233 | static struct notifier_block ftrace_suspend_notifier = { |
6234 | .notifier_call = ftrace_suspend_notifier_call, | |
6235 | }; | |
6236 | ||
287b6e68 FW |
6237 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
6238 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 6239 | { |
e7d3737e FW |
6240 | int ret = 0; |
6241 | ||
e6ea44e9 | 6242 | mutex_lock(&ftrace_lock); |
e7d3737e | 6243 | |
05ce5818 | 6244 | /* we currently allow only one tracer registered at a time */ |
597af815 | 6245 | if (ftrace_graph_active) { |
05ce5818 SR |
6246 | ret = -EBUSY; |
6247 | goto out; | |
6248 | } | |
6249 | ||
4a2b8dda FW |
6250 | register_pm_notifier(&ftrace_suspend_notifier); |
6251 | ||
597af815 | 6252 | ftrace_graph_active++; |
fb52607a | 6253 | ret = start_graph_tracing(); |
f201ae23 | 6254 | if (ret) { |
597af815 | 6255 | ftrace_graph_active--; |
f201ae23 FW |
6256 | goto out; |
6257 | } | |
e53a6319 | 6258 | |
287b6e68 | 6259 | ftrace_graph_return = retfunc; |
23a8e844 SRRH |
6260 | |
6261 | /* | |
6262 | * Update the indirect function to the entryfunc, and the | |
6263 | * function that gets called to the entry_test first. Then | |
6264 | * call the update fgraph entry function to determine if | |
6265 | * the entryfunc should be called directly or not. | |
6266 | */ | |
6267 | __ftrace_graph_entry = entryfunc; | |
6268 | ftrace_graph_entry = ftrace_graph_entry_test; | |
6269 | update_function_graph_func(); | |
e53a6319 | 6270 | |
5f151b24 | 6271 | ret = ftrace_startup(&graph_ops, FTRACE_START_FUNC_RET); |
e7d3737e | 6272 | out: |
e6ea44e9 | 6273 | mutex_unlock(&ftrace_lock); |
e7d3737e | 6274 | return ret; |
15e6cb36 FW |
6275 | } |
6276 | ||
fb52607a | 6277 | void unregister_ftrace_graph(void) |
15e6cb36 | 6278 | { |
e6ea44e9 | 6279 | mutex_lock(&ftrace_lock); |
e7d3737e | 6280 | |
597af815 | 6281 | if (unlikely(!ftrace_graph_active)) |
2aad1b76 SR |
6282 | goto out; |
6283 | ||
597af815 | 6284 | ftrace_graph_active--; |
287b6e68 | 6285 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 6286 | ftrace_graph_entry = ftrace_graph_entry_stub; |
23a8e844 | 6287 | __ftrace_graph_entry = ftrace_graph_entry_stub; |
5f151b24 | 6288 | ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET); |
4a2b8dda | 6289 | unregister_pm_notifier(&ftrace_suspend_notifier); |
38516ab5 | 6290 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
e7d3737e | 6291 | |
f3bea491 SRRH |
6292 | #ifdef CONFIG_DYNAMIC_FTRACE |
6293 | /* | |
6294 | * Function graph does not allocate the trampoline, but | |
6295 | * other global_ops do. We need to reset the ALLOC_TRAMP flag | |
6296 | * if one was used. | |
6297 | */ | |
6298 | global_ops.trampoline = save_global_trampoline; | |
6299 | if (save_global_flags & FTRACE_OPS_FL_ALLOC_TRAMP) | |
6300 | global_ops.flags |= FTRACE_OPS_FL_ALLOC_TRAMP; | |
6301 | #endif | |
6302 | ||
2aad1b76 | 6303 | out: |
e6ea44e9 | 6304 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 6305 | } |
f201ae23 | 6306 | |
868baf07 SR |
6307 | static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack); |
6308 | ||
6309 | static void | |
6310 | graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack) | |
6311 | { | |
6312 | atomic_set(&t->tracing_graph_pause, 0); | |
6313 | atomic_set(&t->trace_overrun, 0); | |
6314 | t->ftrace_timestamp = 0; | |
25985edc | 6315 | /* make curr_ret_stack visible before we add the ret_stack */ |
868baf07 SR |
6316 | smp_wmb(); |
6317 | t->ret_stack = ret_stack; | |
6318 | } | |
6319 | ||
6320 | /* | |
6321 | * Allocate a return stack for the idle task. May be the first | |
6322 | * time through, or it may be done by CPU hotplug online. | |
6323 | */ | |
6324 | void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) | |
6325 | { | |
6326 | t->curr_ret_stack = -1; | |
6327 | /* | |
6328 | * The idle task has no parent, it either has its own | |
6329 | * stack or no stack at all. | |
6330 | */ | |
6331 | if (t->ret_stack) | |
6332 | WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu)); | |
6333 | ||
6334 | if (ftrace_graph_active) { | |
6335 | struct ftrace_ret_stack *ret_stack; | |
6336 | ||
6337 | ret_stack = per_cpu(idle_ret_stack, cpu); | |
6338 | if (!ret_stack) { | |
6339 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
6340 | * sizeof(struct ftrace_ret_stack), | |
6341 | GFP_KERNEL); | |
6342 | if (!ret_stack) | |
6343 | return; | |
6344 | per_cpu(idle_ret_stack, cpu) = ret_stack; | |
6345 | } | |
6346 | graph_init_task(t, ret_stack); | |
6347 | } | |
6348 | } | |
6349 | ||
f201ae23 | 6350 | /* Allocate a return stack for newly created task */ |
fb52607a | 6351 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 6352 | { |
84047e36 SR |
6353 | /* Make sure we do not use the parent ret_stack */ |
6354 | t->ret_stack = NULL; | |
ea14eb71 | 6355 | t->curr_ret_stack = -1; |
84047e36 | 6356 | |
597af815 | 6357 | if (ftrace_graph_active) { |
82310a32 SR |
6358 | struct ftrace_ret_stack *ret_stack; |
6359 | ||
6360 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
f201ae23 FW |
6361 | * sizeof(struct ftrace_ret_stack), |
6362 | GFP_KERNEL); | |
82310a32 | 6363 | if (!ret_stack) |
f201ae23 | 6364 | return; |
868baf07 | 6365 | graph_init_task(t, ret_stack); |
84047e36 | 6366 | } |
f201ae23 FW |
6367 | } |
6368 | ||
fb52607a | 6369 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 6370 | { |
eae849ca FW |
6371 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
6372 | ||
f201ae23 | 6373 | t->ret_stack = NULL; |
eae849ca FW |
6374 | /* NULL must become visible to IRQs before we free it: */ |
6375 | barrier(); | |
6376 | ||
6377 | kfree(ret_stack); | |
f201ae23 | 6378 | } |
15e6cb36 | 6379 | #endif |