Commit | Line | Data |
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16444a8a ACM |
1 | /* |
2 | * Infrastructure for profiling code inserted by 'gcc -pg'. | |
3 | * | |
4 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> | |
5 | * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com> | |
6 | * | |
7 | * Originally ported from the -rt patch by: | |
8 | * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com> | |
9 | * | |
10 | * Based on code in the latency_tracer, that is: | |
11 | * | |
12 | * Copyright (C) 2004-2006 Ingo Molnar | |
6d49e352 | 13 | * Copyright (C) 2004 Nadia Yvette Chambers |
16444a8a ACM |
14 | */ |
15 | ||
3d083395 SR |
16 | #include <linux/stop_machine.h> |
17 | #include <linux/clocksource.h> | |
18 | #include <linux/kallsyms.h> | |
5072c59f | 19 | #include <linux/seq_file.h> |
4a2b8dda | 20 | #include <linux/suspend.h> |
5072c59f | 21 | #include <linux/debugfs.h> |
3d083395 | 22 | #include <linux/hardirq.h> |
2d8b820b | 23 | #include <linux/kthread.h> |
5072c59f | 24 | #include <linux/uaccess.h> |
5855fead | 25 | #include <linux/bsearch.h> |
56d82e00 | 26 | #include <linux/module.h> |
2d8b820b | 27 | #include <linux/ftrace.h> |
b0fc494f | 28 | #include <linux/sysctl.h> |
5a0e3ad6 | 29 | #include <linux/slab.h> |
5072c59f | 30 | #include <linux/ctype.h> |
68950619 | 31 | #include <linux/sort.h> |
3d083395 | 32 | #include <linux/list.h> |
59df055f | 33 | #include <linux/hash.h> |
3f379b03 | 34 | #include <linux/rcupdate.h> |
3d083395 | 35 | |
ad8d75ff | 36 | #include <trace/events/sched.h> |
8aef2d28 | 37 | |
2af15d6a | 38 | #include <asm/setup.h> |
395a59d0 | 39 | |
0706f1c4 | 40 | #include "trace_output.h" |
bac429f0 | 41 | #include "trace_stat.h" |
16444a8a | 42 | |
6912896e | 43 | #define FTRACE_WARN_ON(cond) \ |
0778d9ad SR |
44 | ({ \ |
45 | int ___r = cond; \ | |
46 | if (WARN_ON(___r)) \ | |
6912896e | 47 | ftrace_kill(); \ |
0778d9ad SR |
48 | ___r; \ |
49 | }) | |
6912896e SR |
50 | |
51 | #define FTRACE_WARN_ON_ONCE(cond) \ | |
0778d9ad SR |
52 | ({ \ |
53 | int ___r = cond; \ | |
54 | if (WARN_ON_ONCE(___r)) \ | |
6912896e | 55 | ftrace_kill(); \ |
0778d9ad SR |
56 | ___r; \ |
57 | }) | |
6912896e | 58 | |
8fc0c701 SR |
59 | /* hash bits for specific function selection */ |
60 | #define FTRACE_HASH_BITS 7 | |
61 | #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS) | |
33dc9b12 SR |
62 | #define FTRACE_HASH_DEFAULT_BITS 10 |
63 | #define FTRACE_HASH_MAX_BITS 12 | |
8fc0c701 | 64 | |
e248491a JO |
65 | #define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_CONTROL) |
66 | ||
2f5f6ad9 SR |
67 | static struct ftrace_ops ftrace_list_end __read_mostly = { |
68 | .func = ftrace_stub, | |
4740974a | 69 | .flags = FTRACE_OPS_FL_RECURSION_SAFE, |
2f5f6ad9 SR |
70 | }; |
71 | ||
4eebcc81 SR |
72 | /* ftrace_enabled is a method to turn ftrace on or off */ |
73 | int ftrace_enabled __read_mostly; | |
d61f82d0 | 74 | static int last_ftrace_enabled; |
b0fc494f | 75 | |
60a7ecf4 | 76 | /* Quick disabling of function tracer. */ |
2f5f6ad9 SR |
77 | int function_trace_stop __read_mostly; |
78 | ||
79 | /* Current function tracing op */ | |
80 | struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end; | |
60a7ecf4 | 81 | |
756d17ee | 82 | /* List for set_ftrace_pid's pids. */ |
83 | LIST_HEAD(ftrace_pids); | |
84 | struct ftrace_pid { | |
85 | struct list_head list; | |
86 | struct pid *pid; | |
87 | }; | |
88 | ||
4eebcc81 SR |
89 | /* |
90 | * ftrace_disabled is set when an anomaly is discovered. | |
91 | * ftrace_disabled is much stronger than ftrace_enabled. | |
92 | */ | |
93 | static int ftrace_disabled __read_mostly; | |
94 | ||
52baf119 | 95 | static DEFINE_MUTEX(ftrace_lock); |
b0fc494f | 96 | |
b848914c | 97 | static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end; |
e248491a | 98 | static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end; |
b848914c | 99 | static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end; |
16444a8a | 100 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
df4fc315 | 101 | ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; |
2b499381 | 102 | static struct ftrace_ops global_ops; |
e248491a | 103 | static struct ftrace_ops control_ops; |
16444a8a | 104 | |
2f5f6ad9 SR |
105 | #if ARCH_SUPPORTS_FTRACE_OPS |
106 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 107 | struct ftrace_ops *op, struct pt_regs *regs); |
2f5f6ad9 SR |
108 | #else |
109 | /* See comment below, where ftrace_ops_list_func is defined */ | |
110 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip); | |
111 | #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops) | |
112 | #endif | |
b848914c | 113 | |
0a016409 SR |
114 | /* |
115 | * Traverse the ftrace_global_list, invoking all entries. The reason that we | |
116 | * can use rcu_dereference_raw() is that elements removed from this list | |
117 | * are simply leaked, so there is no need to interact with a grace-period | |
118 | * mechanism. The rcu_dereference_raw() calls are needed to handle | |
119 | * concurrent insertions into the ftrace_global_list. | |
120 | * | |
121 | * Silly Alpha and silly pointer-speculation compiler optimizations! | |
122 | */ | |
123 | #define do_for_each_ftrace_op(op, list) \ | |
124 | op = rcu_dereference_raw(list); \ | |
125 | do | |
126 | ||
127 | /* | |
128 | * Optimized for just a single item in the list (as that is the normal case). | |
129 | */ | |
130 | #define while_for_each_ftrace_op(op) \ | |
131 | while (likely(op = rcu_dereference_raw((op)->next)) && \ | |
132 | unlikely((op) != &ftrace_list_end)) | |
133 | ||
ea701f11 SR |
134 | /** |
135 | * ftrace_nr_registered_ops - return number of ops registered | |
136 | * | |
137 | * Returns the number of ftrace_ops registered and tracing functions | |
138 | */ | |
139 | int ftrace_nr_registered_ops(void) | |
140 | { | |
141 | struct ftrace_ops *ops; | |
142 | int cnt = 0; | |
143 | ||
144 | mutex_lock(&ftrace_lock); | |
145 | ||
146 | for (ops = ftrace_ops_list; | |
147 | ops != &ftrace_list_end; ops = ops->next) | |
148 | cnt++; | |
149 | ||
150 | mutex_unlock(&ftrace_lock); | |
151 | ||
152 | return cnt; | |
153 | } | |
154 | ||
2f5f6ad9 SR |
155 | static void |
156 | ftrace_global_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 157 | struct ftrace_ops *op, struct pt_regs *regs) |
16444a8a | 158 | { |
c29f122c SR |
159 | int bit; |
160 | ||
161 | if (in_interrupt()) { | |
162 | if (in_nmi()) | |
163 | bit = TRACE_GLOBAL_NMI_BIT; | |
164 | ||
165 | else if (in_irq()) | |
166 | bit = TRACE_GLOBAL_IRQ_BIT; | |
167 | else | |
168 | bit = TRACE_GLOBAL_SIRQ_BIT; | |
169 | } else | |
170 | bit = TRACE_GLOBAL_BIT; | |
171 | ||
172 | if (unlikely(trace_recursion_test(bit))) | |
b1cff0ad | 173 | return; |
16444a8a | 174 | |
c29f122c | 175 | trace_recursion_set(bit); |
0a016409 | 176 | do_for_each_ftrace_op(op, ftrace_global_list) { |
a1e2e31d | 177 | op->func(ip, parent_ip, op, regs); |
0a016409 | 178 | } while_for_each_ftrace_op(op); |
c29f122c | 179 | trace_recursion_clear(bit); |
16444a8a ACM |
180 | } |
181 | ||
2f5f6ad9 | 182 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 183 | struct ftrace_ops *op, struct pt_regs *regs) |
df4fc315 | 184 | { |
0ef8cde5 | 185 | if (!test_tsk_trace_trace(current)) |
df4fc315 SR |
186 | return; |
187 | ||
a1e2e31d | 188 | ftrace_pid_function(ip, parent_ip, op, regs); |
df4fc315 SR |
189 | } |
190 | ||
191 | static void set_ftrace_pid_function(ftrace_func_t func) | |
192 | { | |
193 | /* do not set ftrace_pid_function to itself! */ | |
194 | if (func != ftrace_pid_func) | |
195 | ftrace_pid_function = func; | |
196 | } | |
197 | ||
16444a8a | 198 | /** |
3d083395 | 199 | * clear_ftrace_function - reset the ftrace function |
16444a8a | 200 | * |
3d083395 SR |
201 | * This NULLs the ftrace function and in essence stops |
202 | * tracing. There may be lag | |
16444a8a | 203 | */ |
3d083395 | 204 | void clear_ftrace_function(void) |
16444a8a | 205 | { |
3d083395 | 206 | ftrace_trace_function = ftrace_stub; |
df4fc315 | 207 | ftrace_pid_function = ftrace_stub; |
3d083395 SR |
208 | } |
209 | ||
e248491a JO |
210 | static void control_ops_disable_all(struct ftrace_ops *ops) |
211 | { | |
212 | int cpu; | |
213 | ||
214 | for_each_possible_cpu(cpu) | |
215 | *per_cpu_ptr(ops->disabled, cpu) = 1; | |
216 | } | |
217 | ||
218 | static int control_ops_alloc(struct ftrace_ops *ops) | |
219 | { | |
220 | int __percpu *disabled; | |
221 | ||
222 | disabled = alloc_percpu(int); | |
223 | if (!disabled) | |
224 | return -ENOMEM; | |
225 | ||
226 | ops->disabled = disabled; | |
227 | control_ops_disable_all(ops); | |
228 | return 0; | |
229 | } | |
230 | ||
231 | static void control_ops_free(struct ftrace_ops *ops) | |
232 | { | |
233 | free_percpu(ops->disabled); | |
234 | } | |
235 | ||
2b499381 | 236 | static void update_global_ops(void) |
491d0dcf SR |
237 | { |
238 | ftrace_func_t func; | |
239 | ||
240 | /* | |
241 | * If there's only one function registered, then call that | |
242 | * function directly. Otherwise, we need to iterate over the | |
243 | * registered callers. | |
244 | */ | |
b848914c | 245 | if (ftrace_global_list == &ftrace_list_end || |
63503794 | 246 | ftrace_global_list->next == &ftrace_list_end) { |
b848914c | 247 | func = ftrace_global_list->func; |
63503794 SR |
248 | /* |
249 | * As we are calling the function directly. | |
250 | * If it does not have recursion protection, | |
251 | * the function_trace_op needs to be updated | |
252 | * accordingly. | |
253 | */ | |
254 | if (ftrace_global_list->flags & FTRACE_OPS_FL_RECURSION_SAFE) | |
255 | global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE; | |
256 | else | |
257 | global_ops.flags &= ~FTRACE_OPS_FL_RECURSION_SAFE; | |
258 | } else { | |
b848914c | 259 | func = ftrace_global_list_func; |
63503794 SR |
260 | /* The list has its own recursion protection. */ |
261 | global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE; | |
262 | } | |
263 | ||
491d0dcf SR |
264 | |
265 | /* If we filter on pids, update to use the pid function */ | |
266 | if (!list_empty(&ftrace_pids)) { | |
267 | set_ftrace_pid_function(func); | |
268 | func = ftrace_pid_func; | |
269 | } | |
2b499381 SR |
270 | |
271 | global_ops.func = func; | |
272 | } | |
273 | ||
274 | static void update_ftrace_function(void) | |
275 | { | |
276 | ftrace_func_t func; | |
277 | ||
278 | update_global_ops(); | |
279 | ||
cdbe61bf SR |
280 | /* |
281 | * If we are at the end of the list and this ops is | |
4740974a SR |
282 | * recursion safe and not dynamic and the arch supports passing ops, |
283 | * then have the mcount trampoline call the function directly. | |
cdbe61bf | 284 | */ |
b848914c | 285 | if (ftrace_ops_list == &ftrace_list_end || |
cdbe61bf | 286 | (ftrace_ops_list->next == &ftrace_list_end && |
2f5f6ad9 | 287 | !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC) && |
4740974a | 288 | (ftrace_ops_list->flags & FTRACE_OPS_FL_RECURSION_SAFE) && |
ccf3672d | 289 | !FTRACE_FORCE_LIST_FUNC)) { |
2f5f6ad9 SR |
290 | /* Set the ftrace_ops that the arch callback uses */ |
291 | if (ftrace_ops_list == &global_ops) | |
292 | function_trace_op = ftrace_global_list; | |
293 | else | |
294 | function_trace_op = ftrace_ops_list; | |
b848914c | 295 | func = ftrace_ops_list->func; |
2f5f6ad9 SR |
296 | } else { |
297 | /* Just use the default ftrace_ops */ | |
298 | function_trace_op = &ftrace_list_end; | |
b848914c | 299 | func = ftrace_ops_list_func; |
2f5f6ad9 | 300 | } |
2b499381 | 301 | |
491d0dcf | 302 | ftrace_trace_function = func; |
491d0dcf SR |
303 | } |
304 | ||
2b499381 | 305 | static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
3d083395 | 306 | { |
2b499381 | 307 | ops->next = *list; |
16444a8a | 308 | /* |
b848914c | 309 | * We are entering ops into the list but another |
16444a8a ACM |
310 | * CPU might be walking that list. We need to make sure |
311 | * the ops->next pointer is valid before another CPU sees | |
b848914c | 312 | * the ops pointer included into the list. |
16444a8a | 313 | */ |
2b499381 | 314 | rcu_assign_pointer(*list, ops); |
16444a8a ACM |
315 | } |
316 | ||
2b499381 | 317 | static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) |
16444a8a | 318 | { |
16444a8a | 319 | struct ftrace_ops **p; |
16444a8a ACM |
320 | |
321 | /* | |
3d083395 SR |
322 | * If we are removing the last function, then simply point |
323 | * to the ftrace_stub. | |
16444a8a | 324 | */ |
2b499381 SR |
325 | if (*list == ops && ops->next == &ftrace_list_end) { |
326 | *list = &ftrace_list_end; | |
e6ea44e9 | 327 | return 0; |
16444a8a ACM |
328 | } |
329 | ||
2b499381 | 330 | for (p = list; *p != &ftrace_list_end; p = &(*p)->next) |
16444a8a ACM |
331 | if (*p == ops) |
332 | break; | |
333 | ||
e6ea44e9 SR |
334 | if (*p != ops) |
335 | return -1; | |
16444a8a ACM |
336 | |
337 | *p = (*p)->next; | |
2b499381 SR |
338 | return 0; |
339 | } | |
16444a8a | 340 | |
e248491a JO |
341 | static void add_ftrace_list_ops(struct ftrace_ops **list, |
342 | struct ftrace_ops *main_ops, | |
343 | struct ftrace_ops *ops) | |
344 | { | |
345 | int first = *list == &ftrace_list_end; | |
346 | add_ftrace_ops(list, ops); | |
347 | if (first) | |
348 | add_ftrace_ops(&ftrace_ops_list, main_ops); | |
349 | } | |
350 | ||
351 | static int remove_ftrace_list_ops(struct ftrace_ops **list, | |
352 | struct ftrace_ops *main_ops, | |
353 | struct ftrace_ops *ops) | |
354 | { | |
355 | int ret = remove_ftrace_ops(list, ops); | |
356 | if (!ret && *list == &ftrace_list_end) | |
357 | ret = remove_ftrace_ops(&ftrace_ops_list, main_ops); | |
358 | return ret; | |
359 | } | |
360 | ||
2b499381 SR |
361 | static int __register_ftrace_function(struct ftrace_ops *ops) |
362 | { | |
8d240dd8 | 363 | if (unlikely(ftrace_disabled)) |
2b499381 SR |
364 | return -ENODEV; |
365 | ||
366 | if (FTRACE_WARN_ON(ops == &global_ops)) | |
367 | return -EINVAL; | |
368 | ||
b848914c SR |
369 | if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) |
370 | return -EBUSY; | |
371 | ||
e248491a JO |
372 | /* We don't support both control and global flags set. */ |
373 | if ((ops->flags & FL_GLOBAL_CONTROL_MASK) == FL_GLOBAL_CONTROL_MASK) | |
374 | return -EINVAL; | |
375 | ||
06aeaaea | 376 | #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS |
08f6fba5 SR |
377 | /* |
378 | * If the ftrace_ops specifies SAVE_REGS, then it only can be used | |
379 | * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set. | |
380 | * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant. | |
381 | */ | |
382 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS && | |
383 | !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)) | |
384 | return -EINVAL; | |
385 | ||
386 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED) | |
387 | ops->flags |= FTRACE_OPS_FL_SAVE_REGS; | |
388 | #endif | |
389 | ||
cdbe61bf SR |
390 | if (!core_kernel_data((unsigned long)ops)) |
391 | ops->flags |= FTRACE_OPS_FL_DYNAMIC; | |
392 | ||
b848914c | 393 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { |
e248491a | 394 | add_ftrace_list_ops(&ftrace_global_list, &global_ops, ops); |
b848914c | 395 | ops->flags |= FTRACE_OPS_FL_ENABLED; |
e248491a JO |
396 | } else if (ops->flags & FTRACE_OPS_FL_CONTROL) { |
397 | if (control_ops_alloc(ops)) | |
398 | return -ENOMEM; | |
399 | add_ftrace_list_ops(&ftrace_control_list, &control_ops, ops); | |
b848914c SR |
400 | } else |
401 | add_ftrace_ops(&ftrace_ops_list, ops); | |
402 | ||
2b499381 SR |
403 | if (ftrace_enabled) |
404 | update_ftrace_function(); | |
405 | ||
406 | return 0; | |
407 | } | |
408 | ||
409 | static int __unregister_ftrace_function(struct ftrace_ops *ops) | |
410 | { | |
411 | int ret; | |
412 | ||
413 | if (ftrace_disabled) | |
414 | return -ENODEV; | |
415 | ||
b848914c SR |
416 | if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) |
417 | return -EBUSY; | |
418 | ||
2b499381 SR |
419 | if (FTRACE_WARN_ON(ops == &global_ops)) |
420 | return -EINVAL; | |
421 | ||
b848914c | 422 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { |
e248491a JO |
423 | ret = remove_ftrace_list_ops(&ftrace_global_list, |
424 | &global_ops, ops); | |
b848914c SR |
425 | if (!ret) |
426 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; | |
e248491a JO |
427 | } else if (ops->flags & FTRACE_OPS_FL_CONTROL) { |
428 | ret = remove_ftrace_list_ops(&ftrace_control_list, | |
429 | &control_ops, ops); | |
430 | if (!ret) { | |
431 | /* | |
432 | * The ftrace_ops is now removed from the list, | |
433 | * so there'll be no new users. We must ensure | |
434 | * all current users are done before we free | |
435 | * the control data. | |
436 | */ | |
437 | synchronize_sched(); | |
438 | control_ops_free(ops); | |
439 | } | |
b848914c SR |
440 | } else |
441 | ret = remove_ftrace_ops(&ftrace_ops_list, ops); | |
442 | ||
2b499381 SR |
443 | if (ret < 0) |
444 | return ret; | |
b848914c | 445 | |
491d0dcf SR |
446 | if (ftrace_enabled) |
447 | update_ftrace_function(); | |
16444a8a | 448 | |
cdbe61bf SR |
449 | /* |
450 | * Dynamic ops may be freed, we must make sure that all | |
451 | * callers are done before leaving this function. | |
452 | */ | |
453 | if (ops->flags & FTRACE_OPS_FL_DYNAMIC) | |
454 | synchronize_sched(); | |
455 | ||
e6ea44e9 | 456 | return 0; |
3d083395 SR |
457 | } |
458 | ||
df4fc315 SR |
459 | static void ftrace_update_pid_func(void) |
460 | { | |
491d0dcf | 461 | /* Only do something if we are tracing something */ |
df4fc315 | 462 | if (ftrace_trace_function == ftrace_stub) |
10dd3ebe | 463 | return; |
df4fc315 | 464 | |
491d0dcf | 465 | update_ftrace_function(); |
df4fc315 SR |
466 | } |
467 | ||
493762fc SR |
468 | #ifdef CONFIG_FUNCTION_PROFILER |
469 | struct ftrace_profile { | |
470 | struct hlist_node node; | |
471 | unsigned long ip; | |
472 | unsigned long counter; | |
0706f1c4 SR |
473 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
474 | unsigned long long time; | |
e330b3bc | 475 | unsigned long long time_squared; |
0706f1c4 | 476 | #endif |
8fc0c701 SR |
477 | }; |
478 | ||
493762fc SR |
479 | struct ftrace_profile_page { |
480 | struct ftrace_profile_page *next; | |
481 | unsigned long index; | |
482 | struct ftrace_profile records[]; | |
d61f82d0 SR |
483 | }; |
484 | ||
cafb168a SR |
485 | struct ftrace_profile_stat { |
486 | atomic_t disabled; | |
487 | struct hlist_head *hash; | |
488 | struct ftrace_profile_page *pages; | |
489 | struct ftrace_profile_page *start; | |
490 | struct tracer_stat stat; | |
491 | }; | |
492 | ||
493762fc SR |
493 | #define PROFILE_RECORDS_SIZE \ |
494 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) | |
5072c59f | 495 | |
493762fc SR |
496 | #define PROFILES_PER_PAGE \ |
497 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) | |
3d083395 | 498 | |
fb9fb015 SR |
499 | static int ftrace_profile_bits __read_mostly; |
500 | static int ftrace_profile_enabled __read_mostly; | |
501 | ||
502 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ | |
bac429f0 SR |
503 | static DEFINE_MUTEX(ftrace_profile_lock); |
504 | ||
cafb168a | 505 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
493762fc SR |
506 | |
507 | #define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */ | |
508 | ||
bac429f0 SR |
509 | static void * |
510 | function_stat_next(void *v, int idx) | |
511 | { | |
493762fc SR |
512 | struct ftrace_profile *rec = v; |
513 | struct ftrace_profile_page *pg; | |
bac429f0 | 514 | |
493762fc | 515 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
bac429f0 SR |
516 | |
517 | again: | |
0296e425 LZ |
518 | if (idx != 0) |
519 | rec++; | |
520 | ||
bac429f0 SR |
521 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
522 | pg = pg->next; | |
523 | if (!pg) | |
524 | return NULL; | |
525 | rec = &pg->records[0]; | |
493762fc SR |
526 | if (!rec->counter) |
527 | goto again; | |
bac429f0 SR |
528 | } |
529 | ||
bac429f0 SR |
530 | return rec; |
531 | } | |
532 | ||
533 | static void *function_stat_start(struct tracer_stat *trace) | |
534 | { | |
cafb168a SR |
535 | struct ftrace_profile_stat *stat = |
536 | container_of(trace, struct ftrace_profile_stat, stat); | |
537 | ||
538 | if (!stat || !stat->start) | |
539 | return NULL; | |
540 | ||
541 | return function_stat_next(&stat->start->records[0], 0); | |
bac429f0 SR |
542 | } |
543 | ||
0706f1c4 SR |
544 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
545 | /* function graph compares on total time */ | |
546 | static int function_stat_cmp(void *p1, void *p2) | |
547 | { | |
548 | struct ftrace_profile *a = p1; | |
549 | struct ftrace_profile *b = p2; | |
550 | ||
551 | if (a->time < b->time) | |
552 | return -1; | |
553 | if (a->time > b->time) | |
554 | return 1; | |
555 | else | |
556 | return 0; | |
557 | } | |
558 | #else | |
559 | /* not function graph compares against hits */ | |
bac429f0 SR |
560 | static int function_stat_cmp(void *p1, void *p2) |
561 | { | |
493762fc SR |
562 | struct ftrace_profile *a = p1; |
563 | struct ftrace_profile *b = p2; | |
bac429f0 SR |
564 | |
565 | if (a->counter < b->counter) | |
566 | return -1; | |
567 | if (a->counter > b->counter) | |
568 | return 1; | |
569 | else | |
570 | return 0; | |
571 | } | |
0706f1c4 | 572 | #endif |
bac429f0 SR |
573 | |
574 | static int function_stat_headers(struct seq_file *m) | |
575 | { | |
0706f1c4 | 576 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b | 577 | seq_printf(m, " Function " |
e330b3bc | 578 | "Hit Time Avg s^2\n" |
34886c8b | 579 | " -------- " |
e330b3bc | 580 | "--- ---- --- ---\n"); |
0706f1c4 | 581 | #else |
bac429f0 SR |
582 | seq_printf(m, " Function Hit\n" |
583 | " -------- ---\n"); | |
0706f1c4 | 584 | #endif |
bac429f0 SR |
585 | return 0; |
586 | } | |
587 | ||
588 | static int function_stat_show(struct seq_file *m, void *v) | |
589 | { | |
493762fc | 590 | struct ftrace_profile *rec = v; |
bac429f0 | 591 | char str[KSYM_SYMBOL_LEN]; |
3aaba20f | 592 | int ret = 0; |
0706f1c4 | 593 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
34886c8b SR |
594 | static struct trace_seq s; |
595 | unsigned long long avg; | |
e330b3bc | 596 | unsigned long long stddev; |
0706f1c4 | 597 | #endif |
3aaba20f LZ |
598 | mutex_lock(&ftrace_profile_lock); |
599 | ||
600 | /* we raced with function_profile_reset() */ | |
601 | if (unlikely(rec->counter == 0)) { | |
602 | ret = -EBUSY; | |
603 | goto out; | |
604 | } | |
bac429f0 SR |
605 | |
606 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); | |
0706f1c4 SR |
607 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
608 | ||
609 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
610 | seq_printf(m, " "); | |
34886c8b SR |
611 | avg = rec->time; |
612 | do_div(avg, rec->counter); | |
613 | ||
e330b3bc CD |
614 | /* Sample standard deviation (s^2) */ |
615 | if (rec->counter <= 1) | |
616 | stddev = 0; | |
617 | else { | |
618 | stddev = rec->time_squared - rec->counter * avg * avg; | |
619 | /* | |
620 | * Divide only 1000 for ns^2 -> us^2 conversion. | |
621 | * trace_print_graph_duration will divide 1000 again. | |
622 | */ | |
623 | do_div(stddev, (rec->counter - 1) * 1000); | |
624 | } | |
625 | ||
34886c8b SR |
626 | trace_seq_init(&s); |
627 | trace_print_graph_duration(rec->time, &s); | |
628 | trace_seq_puts(&s, " "); | |
629 | trace_print_graph_duration(avg, &s); | |
e330b3bc CD |
630 | trace_seq_puts(&s, " "); |
631 | trace_print_graph_duration(stddev, &s); | |
0706f1c4 | 632 | trace_print_seq(m, &s); |
0706f1c4 SR |
633 | #endif |
634 | seq_putc(m, '\n'); | |
3aaba20f LZ |
635 | out: |
636 | mutex_unlock(&ftrace_profile_lock); | |
bac429f0 | 637 | |
3aaba20f | 638 | return ret; |
bac429f0 SR |
639 | } |
640 | ||
cafb168a | 641 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
bac429f0 | 642 | { |
493762fc | 643 | struct ftrace_profile_page *pg; |
bac429f0 | 644 | |
cafb168a | 645 | pg = stat->pages = stat->start; |
bac429f0 | 646 | |
493762fc SR |
647 | while (pg) { |
648 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); | |
649 | pg->index = 0; | |
650 | pg = pg->next; | |
bac429f0 SR |
651 | } |
652 | ||
cafb168a | 653 | memset(stat->hash, 0, |
493762fc SR |
654 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
655 | } | |
bac429f0 | 656 | |
cafb168a | 657 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
493762fc SR |
658 | { |
659 | struct ftrace_profile_page *pg; | |
318e0a73 SR |
660 | int functions; |
661 | int pages; | |
493762fc | 662 | int i; |
bac429f0 | 663 | |
493762fc | 664 | /* If we already allocated, do nothing */ |
cafb168a | 665 | if (stat->pages) |
493762fc | 666 | return 0; |
bac429f0 | 667 | |
cafb168a SR |
668 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
669 | if (!stat->pages) | |
493762fc | 670 | return -ENOMEM; |
bac429f0 | 671 | |
318e0a73 SR |
672 | #ifdef CONFIG_DYNAMIC_FTRACE |
673 | functions = ftrace_update_tot_cnt; | |
674 | #else | |
675 | /* | |
676 | * We do not know the number of functions that exist because | |
677 | * dynamic tracing is what counts them. With past experience | |
678 | * we have around 20K functions. That should be more than enough. | |
679 | * It is highly unlikely we will execute every function in | |
680 | * the kernel. | |
681 | */ | |
682 | functions = 20000; | |
683 | #endif | |
684 | ||
cafb168a | 685 | pg = stat->start = stat->pages; |
bac429f0 | 686 | |
318e0a73 SR |
687 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
688 | ||
689 | for (i = 0; i < pages; i++) { | |
493762fc | 690 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
493762fc | 691 | if (!pg->next) |
318e0a73 | 692 | goto out_free; |
493762fc SR |
693 | pg = pg->next; |
694 | } | |
695 | ||
696 | return 0; | |
318e0a73 SR |
697 | |
698 | out_free: | |
699 | pg = stat->start; | |
700 | while (pg) { | |
701 | unsigned long tmp = (unsigned long)pg; | |
702 | ||
703 | pg = pg->next; | |
704 | free_page(tmp); | |
705 | } | |
706 | ||
707 | free_page((unsigned long)stat->pages); | |
708 | stat->pages = NULL; | |
709 | stat->start = NULL; | |
710 | ||
711 | return -ENOMEM; | |
bac429f0 SR |
712 | } |
713 | ||
cafb168a | 714 | static int ftrace_profile_init_cpu(int cpu) |
bac429f0 | 715 | { |
cafb168a | 716 | struct ftrace_profile_stat *stat; |
493762fc | 717 | int size; |
bac429f0 | 718 | |
cafb168a SR |
719 | stat = &per_cpu(ftrace_profile_stats, cpu); |
720 | ||
721 | if (stat->hash) { | |
493762fc | 722 | /* If the profile is already created, simply reset it */ |
cafb168a | 723 | ftrace_profile_reset(stat); |
493762fc SR |
724 | return 0; |
725 | } | |
bac429f0 | 726 | |
493762fc SR |
727 | /* |
728 | * We are profiling all functions, but usually only a few thousand | |
729 | * functions are hit. We'll make a hash of 1024 items. | |
730 | */ | |
731 | size = FTRACE_PROFILE_HASH_SIZE; | |
bac429f0 | 732 | |
cafb168a | 733 | stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
493762fc | 734 | |
cafb168a | 735 | if (!stat->hash) |
493762fc SR |
736 | return -ENOMEM; |
737 | ||
cafb168a SR |
738 | if (!ftrace_profile_bits) { |
739 | size--; | |
493762fc | 740 | |
cafb168a SR |
741 | for (; size; size >>= 1) |
742 | ftrace_profile_bits++; | |
743 | } | |
493762fc | 744 | |
318e0a73 | 745 | /* Preallocate the function profiling pages */ |
cafb168a SR |
746 | if (ftrace_profile_pages_init(stat) < 0) { |
747 | kfree(stat->hash); | |
748 | stat->hash = NULL; | |
493762fc SR |
749 | return -ENOMEM; |
750 | } | |
751 | ||
752 | return 0; | |
bac429f0 SR |
753 | } |
754 | ||
cafb168a SR |
755 | static int ftrace_profile_init(void) |
756 | { | |
757 | int cpu; | |
758 | int ret = 0; | |
759 | ||
760 | for_each_online_cpu(cpu) { | |
761 | ret = ftrace_profile_init_cpu(cpu); | |
762 | if (ret) | |
763 | break; | |
764 | } | |
765 | ||
766 | return ret; | |
767 | } | |
768 | ||
493762fc | 769 | /* interrupts must be disabled */ |
cafb168a SR |
770 | static struct ftrace_profile * |
771 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) | |
bac429f0 | 772 | { |
493762fc | 773 | struct ftrace_profile *rec; |
bac429f0 SR |
774 | struct hlist_head *hhd; |
775 | struct hlist_node *n; | |
bac429f0 SR |
776 | unsigned long key; |
777 | ||
bac429f0 | 778 | key = hash_long(ip, ftrace_profile_bits); |
cafb168a | 779 | hhd = &stat->hash[key]; |
bac429f0 SR |
780 | |
781 | if (hlist_empty(hhd)) | |
782 | return NULL; | |
783 | ||
bac429f0 SR |
784 | hlist_for_each_entry_rcu(rec, n, hhd, node) { |
785 | if (rec->ip == ip) | |
493762fc SR |
786 | return rec; |
787 | } | |
788 | ||
789 | return NULL; | |
790 | } | |
791 | ||
cafb168a SR |
792 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
793 | struct ftrace_profile *rec) | |
493762fc SR |
794 | { |
795 | unsigned long key; | |
796 | ||
797 | key = hash_long(rec->ip, ftrace_profile_bits); | |
cafb168a | 798 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
493762fc SR |
799 | } |
800 | ||
318e0a73 SR |
801 | /* |
802 | * The memory is already allocated, this simply finds a new record to use. | |
803 | */ | |
493762fc | 804 | static struct ftrace_profile * |
318e0a73 | 805 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
493762fc SR |
806 | { |
807 | struct ftrace_profile *rec = NULL; | |
808 | ||
318e0a73 | 809 | /* prevent recursion (from NMIs) */ |
cafb168a | 810 | if (atomic_inc_return(&stat->disabled) != 1) |
493762fc SR |
811 | goto out; |
812 | ||
493762fc | 813 | /* |
318e0a73 SR |
814 | * Try to find the function again since an NMI |
815 | * could have added it | |
493762fc | 816 | */ |
cafb168a | 817 | rec = ftrace_find_profiled_func(stat, ip); |
493762fc | 818 | if (rec) |
cafb168a | 819 | goto out; |
493762fc | 820 | |
cafb168a SR |
821 | if (stat->pages->index == PROFILES_PER_PAGE) { |
822 | if (!stat->pages->next) | |
823 | goto out; | |
824 | stat->pages = stat->pages->next; | |
bac429f0 | 825 | } |
493762fc | 826 | |
cafb168a | 827 | rec = &stat->pages->records[stat->pages->index++]; |
493762fc | 828 | rec->ip = ip; |
cafb168a | 829 | ftrace_add_profile(stat, rec); |
493762fc | 830 | |
bac429f0 | 831 | out: |
cafb168a | 832 | atomic_dec(&stat->disabled); |
bac429f0 SR |
833 | |
834 | return rec; | |
835 | } | |
836 | ||
837 | static void | |
2f5f6ad9 | 838 | function_profile_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 839 | struct ftrace_ops *ops, struct pt_regs *regs) |
bac429f0 | 840 | { |
cafb168a | 841 | struct ftrace_profile_stat *stat; |
493762fc | 842 | struct ftrace_profile *rec; |
bac429f0 SR |
843 | unsigned long flags; |
844 | ||
845 | if (!ftrace_profile_enabled) | |
846 | return; | |
847 | ||
848 | local_irq_save(flags); | |
cafb168a SR |
849 | |
850 | stat = &__get_cpu_var(ftrace_profile_stats); | |
0f6ce3de | 851 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
852 | goto out; |
853 | ||
854 | rec = ftrace_find_profiled_func(stat, ip); | |
493762fc | 855 | if (!rec) { |
318e0a73 | 856 | rec = ftrace_profile_alloc(stat, ip); |
493762fc SR |
857 | if (!rec) |
858 | goto out; | |
859 | } | |
bac429f0 SR |
860 | |
861 | rec->counter++; | |
862 | out: | |
863 | local_irq_restore(flags); | |
864 | } | |
865 | ||
0706f1c4 SR |
866 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
867 | static int profile_graph_entry(struct ftrace_graph_ent *trace) | |
868 | { | |
a1e2e31d | 869 | function_profile_call(trace->func, 0, NULL, NULL); |
0706f1c4 SR |
870 | return 1; |
871 | } | |
872 | ||
873 | static void profile_graph_return(struct ftrace_graph_ret *trace) | |
874 | { | |
cafb168a | 875 | struct ftrace_profile_stat *stat; |
a2a16d6a | 876 | unsigned long long calltime; |
0706f1c4 | 877 | struct ftrace_profile *rec; |
cafb168a | 878 | unsigned long flags; |
0706f1c4 SR |
879 | |
880 | local_irq_save(flags); | |
cafb168a | 881 | stat = &__get_cpu_var(ftrace_profile_stats); |
0f6ce3de | 882 | if (!stat->hash || !ftrace_profile_enabled) |
cafb168a SR |
883 | goto out; |
884 | ||
37e44bc5 SR |
885 | /* If the calltime was zero'd ignore it */ |
886 | if (!trace->calltime) | |
887 | goto out; | |
888 | ||
a2a16d6a SR |
889 | calltime = trace->rettime - trace->calltime; |
890 | ||
891 | if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) { | |
892 | int index; | |
893 | ||
894 | index = trace->depth; | |
895 | ||
896 | /* Append this call time to the parent time to subtract */ | |
897 | if (index) | |
898 | current->ret_stack[index - 1].subtime += calltime; | |
899 | ||
900 | if (current->ret_stack[index].subtime < calltime) | |
901 | calltime -= current->ret_stack[index].subtime; | |
902 | else | |
903 | calltime = 0; | |
904 | } | |
905 | ||
cafb168a | 906 | rec = ftrace_find_profiled_func(stat, trace->func); |
e330b3bc | 907 | if (rec) { |
a2a16d6a | 908 | rec->time += calltime; |
e330b3bc CD |
909 | rec->time_squared += calltime * calltime; |
910 | } | |
a2a16d6a | 911 | |
cafb168a | 912 | out: |
0706f1c4 SR |
913 | local_irq_restore(flags); |
914 | } | |
915 | ||
916 | static int register_ftrace_profiler(void) | |
917 | { | |
918 | return register_ftrace_graph(&profile_graph_return, | |
919 | &profile_graph_entry); | |
920 | } | |
921 | ||
922 | static void unregister_ftrace_profiler(void) | |
923 | { | |
924 | unregister_ftrace_graph(); | |
925 | } | |
926 | #else | |
bd38c0e6 | 927 | static struct ftrace_ops ftrace_profile_ops __read_mostly = { |
fb9fb015 | 928 | .func = function_profile_call, |
4740974a | 929 | .flags = FTRACE_OPS_FL_RECURSION_SAFE, |
bac429f0 SR |
930 | }; |
931 | ||
0706f1c4 SR |
932 | static int register_ftrace_profiler(void) |
933 | { | |
934 | return register_ftrace_function(&ftrace_profile_ops); | |
935 | } | |
936 | ||
937 | static void unregister_ftrace_profiler(void) | |
938 | { | |
939 | unregister_ftrace_function(&ftrace_profile_ops); | |
940 | } | |
941 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
942 | ||
bac429f0 SR |
943 | static ssize_t |
944 | ftrace_profile_write(struct file *filp, const char __user *ubuf, | |
945 | size_t cnt, loff_t *ppos) | |
946 | { | |
947 | unsigned long val; | |
bac429f0 SR |
948 | int ret; |
949 | ||
22fe9b54 PH |
950 | ret = kstrtoul_from_user(ubuf, cnt, 10, &val); |
951 | if (ret) | |
bac429f0 SR |
952 | return ret; |
953 | ||
954 | val = !!val; | |
955 | ||
956 | mutex_lock(&ftrace_profile_lock); | |
957 | if (ftrace_profile_enabled ^ val) { | |
958 | if (val) { | |
493762fc SR |
959 | ret = ftrace_profile_init(); |
960 | if (ret < 0) { | |
961 | cnt = ret; | |
962 | goto out; | |
963 | } | |
964 | ||
0706f1c4 SR |
965 | ret = register_ftrace_profiler(); |
966 | if (ret < 0) { | |
967 | cnt = ret; | |
968 | goto out; | |
969 | } | |
bac429f0 SR |
970 | ftrace_profile_enabled = 1; |
971 | } else { | |
972 | ftrace_profile_enabled = 0; | |
0f6ce3de SR |
973 | /* |
974 | * unregister_ftrace_profiler calls stop_machine | |
975 | * so this acts like an synchronize_sched. | |
976 | */ | |
0706f1c4 | 977 | unregister_ftrace_profiler(); |
bac429f0 SR |
978 | } |
979 | } | |
493762fc | 980 | out: |
bac429f0 SR |
981 | mutex_unlock(&ftrace_profile_lock); |
982 | ||
cf8517cf | 983 | *ppos += cnt; |
bac429f0 SR |
984 | |
985 | return cnt; | |
986 | } | |
987 | ||
493762fc SR |
988 | static ssize_t |
989 | ftrace_profile_read(struct file *filp, char __user *ubuf, | |
990 | size_t cnt, loff_t *ppos) | |
991 | { | |
fb9fb015 | 992 | char buf[64]; /* big enough to hold a number */ |
493762fc SR |
993 | int r; |
994 | ||
995 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); | |
996 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); | |
997 | } | |
998 | ||
bac429f0 SR |
999 | static const struct file_operations ftrace_profile_fops = { |
1000 | .open = tracing_open_generic, | |
1001 | .read = ftrace_profile_read, | |
1002 | .write = ftrace_profile_write, | |
6038f373 | 1003 | .llseek = default_llseek, |
bac429f0 SR |
1004 | }; |
1005 | ||
cafb168a SR |
1006 | /* used to initialize the real stat files */ |
1007 | static struct tracer_stat function_stats __initdata = { | |
fb9fb015 SR |
1008 | .name = "functions", |
1009 | .stat_start = function_stat_start, | |
1010 | .stat_next = function_stat_next, | |
1011 | .stat_cmp = function_stat_cmp, | |
1012 | .stat_headers = function_stat_headers, | |
1013 | .stat_show = function_stat_show | |
cafb168a SR |
1014 | }; |
1015 | ||
6ab5d668 | 1016 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 | 1017 | { |
cafb168a | 1018 | struct ftrace_profile_stat *stat; |
bac429f0 | 1019 | struct dentry *entry; |
cafb168a | 1020 | char *name; |
bac429f0 | 1021 | int ret; |
cafb168a SR |
1022 | int cpu; |
1023 | ||
1024 | for_each_possible_cpu(cpu) { | |
1025 | stat = &per_cpu(ftrace_profile_stats, cpu); | |
1026 | ||
1027 | /* allocate enough for function name + cpu number */ | |
1028 | name = kmalloc(32, GFP_KERNEL); | |
1029 | if (!name) { | |
1030 | /* | |
1031 | * The files created are permanent, if something happens | |
1032 | * we still do not free memory. | |
1033 | */ | |
cafb168a SR |
1034 | WARN(1, |
1035 | "Could not allocate stat file for cpu %d\n", | |
1036 | cpu); | |
1037 | return; | |
1038 | } | |
1039 | stat->stat = function_stats; | |
1040 | snprintf(name, 32, "function%d", cpu); | |
1041 | stat->stat.name = name; | |
1042 | ret = register_stat_tracer(&stat->stat); | |
1043 | if (ret) { | |
1044 | WARN(1, | |
1045 | "Could not register function stat for cpu %d\n", | |
1046 | cpu); | |
1047 | kfree(name); | |
1048 | return; | |
1049 | } | |
bac429f0 SR |
1050 | } |
1051 | ||
1052 | entry = debugfs_create_file("function_profile_enabled", 0644, | |
1053 | d_tracer, NULL, &ftrace_profile_fops); | |
1054 | if (!entry) | |
1055 | pr_warning("Could not create debugfs " | |
1056 | "'function_profile_enabled' entry\n"); | |
1057 | } | |
1058 | ||
bac429f0 | 1059 | #else /* CONFIG_FUNCTION_PROFILER */ |
6ab5d668 | 1060 | static __init void ftrace_profile_debugfs(struct dentry *d_tracer) |
bac429f0 SR |
1061 | { |
1062 | } | |
bac429f0 SR |
1063 | #endif /* CONFIG_FUNCTION_PROFILER */ |
1064 | ||
493762fc SR |
1065 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; |
1066 | ||
1067 | #ifdef CONFIG_DYNAMIC_FTRACE | |
1068 | ||
1069 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD | |
1070 | # error Dynamic ftrace depends on MCOUNT_RECORD | |
1071 | #endif | |
1072 | ||
1073 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; | |
1074 | ||
1075 | struct ftrace_func_probe { | |
1076 | struct hlist_node node; | |
1077 | struct ftrace_probe_ops *ops; | |
1078 | unsigned long flags; | |
1079 | unsigned long ip; | |
1080 | void *data; | |
1081 | struct rcu_head rcu; | |
1082 | }; | |
1083 | ||
b448c4e3 SR |
1084 | struct ftrace_func_entry { |
1085 | struct hlist_node hlist; | |
1086 | unsigned long ip; | |
1087 | }; | |
1088 | ||
1089 | struct ftrace_hash { | |
1090 | unsigned long size_bits; | |
1091 | struct hlist_head *buckets; | |
1092 | unsigned long count; | |
07fd5515 | 1093 | struct rcu_head rcu; |
b448c4e3 SR |
1094 | }; |
1095 | ||
33dc9b12 SR |
1096 | /* |
1097 | * We make these constant because no one should touch them, | |
1098 | * but they are used as the default "empty hash", to avoid allocating | |
1099 | * it all the time. These are in a read only section such that if | |
1100 | * anyone does try to modify it, it will cause an exception. | |
1101 | */ | |
1102 | static const struct hlist_head empty_buckets[1]; | |
1103 | static const struct ftrace_hash empty_hash = { | |
1104 | .buckets = (struct hlist_head *)empty_buckets, | |
1cf41dd7 | 1105 | }; |
33dc9b12 | 1106 | #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash) |
493762fc | 1107 | |
2b499381 | 1108 | static struct ftrace_ops global_ops = { |
f45948e8 | 1109 | .func = ftrace_stub, |
33dc9b12 SR |
1110 | .notrace_hash = EMPTY_HASH, |
1111 | .filter_hash = EMPTY_HASH, | |
4740974a | 1112 | .flags = FTRACE_OPS_FL_RECURSION_SAFE, |
f45948e8 SR |
1113 | }; |
1114 | ||
493762fc SR |
1115 | static DEFINE_MUTEX(ftrace_regex_lock); |
1116 | ||
1117 | struct ftrace_page { | |
1118 | struct ftrace_page *next; | |
a7900875 | 1119 | struct dyn_ftrace *records; |
493762fc | 1120 | int index; |
a7900875 | 1121 | int size; |
493762fc SR |
1122 | }; |
1123 | ||
85ae32ae SR |
1124 | static struct ftrace_page *ftrace_new_pgs; |
1125 | ||
a7900875 SR |
1126 | #define ENTRY_SIZE sizeof(struct dyn_ftrace) |
1127 | #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE) | |
493762fc SR |
1128 | |
1129 | /* estimate from running different kernels */ | |
1130 | #define NR_TO_INIT 10000 | |
1131 | ||
1132 | static struct ftrace_page *ftrace_pages_start; | |
1133 | static struct ftrace_page *ftrace_pages; | |
1134 | ||
06a51d93 SR |
1135 | static bool ftrace_hash_empty(struct ftrace_hash *hash) |
1136 | { | |
1137 | return !hash || !hash->count; | |
1138 | } | |
1139 | ||
b448c4e3 SR |
1140 | static struct ftrace_func_entry * |
1141 | ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip) | |
1142 | { | |
1143 | unsigned long key; | |
1144 | struct ftrace_func_entry *entry; | |
1145 | struct hlist_head *hhd; | |
1146 | struct hlist_node *n; | |
1147 | ||
06a51d93 | 1148 | if (ftrace_hash_empty(hash)) |
b448c4e3 SR |
1149 | return NULL; |
1150 | ||
1151 | if (hash->size_bits > 0) | |
1152 | key = hash_long(ip, hash->size_bits); | |
1153 | else | |
1154 | key = 0; | |
1155 | ||
1156 | hhd = &hash->buckets[key]; | |
1157 | ||
1158 | hlist_for_each_entry_rcu(entry, n, hhd, hlist) { | |
1159 | if (entry->ip == ip) | |
1160 | return entry; | |
1161 | } | |
1162 | return NULL; | |
1163 | } | |
1164 | ||
33dc9b12 SR |
1165 | static void __add_hash_entry(struct ftrace_hash *hash, |
1166 | struct ftrace_func_entry *entry) | |
b448c4e3 | 1167 | { |
b448c4e3 SR |
1168 | struct hlist_head *hhd; |
1169 | unsigned long key; | |
1170 | ||
b448c4e3 | 1171 | if (hash->size_bits) |
33dc9b12 | 1172 | key = hash_long(entry->ip, hash->size_bits); |
b448c4e3 SR |
1173 | else |
1174 | key = 0; | |
1175 | ||
b448c4e3 SR |
1176 | hhd = &hash->buckets[key]; |
1177 | hlist_add_head(&entry->hlist, hhd); | |
1178 | hash->count++; | |
33dc9b12 SR |
1179 | } |
1180 | ||
1181 | static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip) | |
1182 | { | |
1183 | struct ftrace_func_entry *entry; | |
1184 | ||
1185 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
1186 | if (!entry) | |
1187 | return -ENOMEM; | |
1188 | ||
1189 | entry->ip = ip; | |
1190 | __add_hash_entry(hash, entry); | |
b448c4e3 SR |
1191 | |
1192 | return 0; | |
1193 | } | |
1194 | ||
1195 | static void | |
33dc9b12 | 1196 | free_hash_entry(struct ftrace_hash *hash, |
b448c4e3 SR |
1197 | struct ftrace_func_entry *entry) |
1198 | { | |
1199 | hlist_del(&entry->hlist); | |
1200 | kfree(entry); | |
1201 | hash->count--; | |
1202 | } | |
1203 | ||
33dc9b12 SR |
1204 | static void |
1205 | remove_hash_entry(struct ftrace_hash *hash, | |
1206 | struct ftrace_func_entry *entry) | |
1207 | { | |
1208 | hlist_del(&entry->hlist); | |
1209 | hash->count--; | |
1210 | } | |
1211 | ||
b448c4e3 SR |
1212 | static void ftrace_hash_clear(struct ftrace_hash *hash) |
1213 | { | |
1214 | struct hlist_head *hhd; | |
1215 | struct hlist_node *tp, *tn; | |
1216 | struct ftrace_func_entry *entry; | |
1217 | int size = 1 << hash->size_bits; | |
1218 | int i; | |
1219 | ||
33dc9b12 SR |
1220 | if (!hash->count) |
1221 | return; | |
1222 | ||
b448c4e3 SR |
1223 | for (i = 0; i < size; i++) { |
1224 | hhd = &hash->buckets[i]; | |
1225 | hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist) | |
33dc9b12 | 1226 | free_hash_entry(hash, entry); |
b448c4e3 SR |
1227 | } |
1228 | FTRACE_WARN_ON(hash->count); | |
1229 | } | |
1230 | ||
33dc9b12 SR |
1231 | static void free_ftrace_hash(struct ftrace_hash *hash) |
1232 | { | |
1233 | if (!hash || hash == EMPTY_HASH) | |
1234 | return; | |
1235 | ftrace_hash_clear(hash); | |
1236 | kfree(hash->buckets); | |
1237 | kfree(hash); | |
1238 | } | |
1239 | ||
07fd5515 SR |
1240 | static void __free_ftrace_hash_rcu(struct rcu_head *rcu) |
1241 | { | |
1242 | struct ftrace_hash *hash; | |
1243 | ||
1244 | hash = container_of(rcu, struct ftrace_hash, rcu); | |
1245 | free_ftrace_hash(hash); | |
1246 | } | |
1247 | ||
1248 | static void free_ftrace_hash_rcu(struct ftrace_hash *hash) | |
1249 | { | |
1250 | if (!hash || hash == EMPTY_HASH) | |
1251 | return; | |
1252 | call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu); | |
1253 | } | |
1254 | ||
5500fa51 JO |
1255 | void ftrace_free_filter(struct ftrace_ops *ops) |
1256 | { | |
1257 | free_ftrace_hash(ops->filter_hash); | |
1258 | free_ftrace_hash(ops->notrace_hash); | |
1259 | } | |
1260 | ||
33dc9b12 SR |
1261 | static struct ftrace_hash *alloc_ftrace_hash(int size_bits) |
1262 | { | |
1263 | struct ftrace_hash *hash; | |
1264 | int size; | |
1265 | ||
1266 | hash = kzalloc(sizeof(*hash), GFP_KERNEL); | |
1267 | if (!hash) | |
1268 | return NULL; | |
1269 | ||
1270 | size = 1 << size_bits; | |
47b0edcb | 1271 | hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL); |
33dc9b12 SR |
1272 | |
1273 | if (!hash->buckets) { | |
1274 | kfree(hash); | |
1275 | return NULL; | |
1276 | } | |
1277 | ||
1278 | hash->size_bits = size_bits; | |
1279 | ||
1280 | return hash; | |
1281 | } | |
1282 | ||
1283 | static struct ftrace_hash * | |
1284 | alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash) | |
1285 | { | |
1286 | struct ftrace_func_entry *entry; | |
1287 | struct ftrace_hash *new_hash; | |
1288 | struct hlist_node *tp; | |
1289 | int size; | |
1290 | int ret; | |
1291 | int i; | |
1292 | ||
1293 | new_hash = alloc_ftrace_hash(size_bits); | |
1294 | if (!new_hash) | |
1295 | return NULL; | |
1296 | ||
1297 | /* Empty hash? */ | |
06a51d93 | 1298 | if (ftrace_hash_empty(hash)) |
33dc9b12 SR |
1299 | return new_hash; |
1300 | ||
1301 | size = 1 << hash->size_bits; | |
1302 | for (i = 0; i < size; i++) { | |
1303 | hlist_for_each_entry(entry, tp, &hash->buckets[i], hlist) { | |
1304 | ret = add_hash_entry(new_hash, entry->ip); | |
1305 | if (ret < 0) | |
1306 | goto free_hash; | |
1307 | } | |
1308 | } | |
1309 | ||
1310 | FTRACE_WARN_ON(new_hash->count != hash->count); | |
1311 | ||
1312 | return new_hash; | |
1313 | ||
1314 | free_hash: | |
1315 | free_ftrace_hash(new_hash); | |
1316 | return NULL; | |
1317 | } | |
1318 | ||
41fb61c2 SR |
1319 | static void |
1320 | ftrace_hash_rec_disable(struct ftrace_ops *ops, int filter_hash); | |
1321 | static void | |
1322 | ftrace_hash_rec_enable(struct ftrace_ops *ops, int filter_hash); | |
1323 | ||
33dc9b12 | 1324 | static int |
41fb61c2 SR |
1325 | ftrace_hash_move(struct ftrace_ops *ops, int enable, |
1326 | struct ftrace_hash **dst, struct ftrace_hash *src) | |
33dc9b12 SR |
1327 | { |
1328 | struct ftrace_func_entry *entry; | |
1329 | struct hlist_node *tp, *tn; | |
1330 | struct hlist_head *hhd; | |
07fd5515 SR |
1331 | struct ftrace_hash *old_hash; |
1332 | struct ftrace_hash *new_hash; | |
33dc9b12 SR |
1333 | unsigned long key; |
1334 | int size = src->count; | |
1335 | int bits = 0; | |
41fb61c2 | 1336 | int ret; |
33dc9b12 SR |
1337 | int i; |
1338 | ||
41fb61c2 SR |
1339 | /* |
1340 | * Remove the current set, update the hash and add | |
1341 | * them back. | |
1342 | */ | |
1343 | ftrace_hash_rec_disable(ops, enable); | |
1344 | ||
33dc9b12 SR |
1345 | /* |
1346 | * If the new source is empty, just free dst and assign it | |
1347 | * the empty_hash. | |
1348 | */ | |
1349 | if (!src->count) { | |
07fd5515 SR |
1350 | free_ftrace_hash_rcu(*dst); |
1351 | rcu_assign_pointer(*dst, EMPTY_HASH); | |
d4d34b98 SR |
1352 | /* still need to update the function records */ |
1353 | ret = 0; | |
1354 | goto out; | |
33dc9b12 SR |
1355 | } |
1356 | ||
33dc9b12 SR |
1357 | /* |
1358 | * Make the hash size about 1/2 the # found | |
1359 | */ | |
1360 | for (size /= 2; size; size >>= 1) | |
1361 | bits++; | |
1362 | ||
1363 | /* Don't allocate too much */ | |
1364 | if (bits > FTRACE_HASH_MAX_BITS) | |
1365 | bits = FTRACE_HASH_MAX_BITS; | |
1366 | ||
41fb61c2 | 1367 | ret = -ENOMEM; |
07fd5515 SR |
1368 | new_hash = alloc_ftrace_hash(bits); |
1369 | if (!new_hash) | |
41fb61c2 | 1370 | goto out; |
33dc9b12 SR |
1371 | |
1372 | size = 1 << src->size_bits; | |
1373 | for (i = 0; i < size; i++) { | |
1374 | hhd = &src->buckets[i]; | |
1375 | hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist) { | |
1376 | if (bits > 0) | |
1377 | key = hash_long(entry->ip, bits); | |
1378 | else | |
1379 | key = 0; | |
1380 | remove_hash_entry(src, entry); | |
07fd5515 | 1381 | __add_hash_entry(new_hash, entry); |
33dc9b12 SR |
1382 | } |
1383 | } | |
1384 | ||
07fd5515 SR |
1385 | old_hash = *dst; |
1386 | rcu_assign_pointer(*dst, new_hash); | |
1387 | free_ftrace_hash_rcu(old_hash); | |
1388 | ||
41fb61c2 SR |
1389 | ret = 0; |
1390 | out: | |
1391 | /* | |
1392 | * Enable regardless of ret: | |
1393 | * On success, we enable the new hash. | |
1394 | * On failure, we re-enable the original hash. | |
1395 | */ | |
1396 | ftrace_hash_rec_enable(ops, enable); | |
1397 | ||
1398 | return ret; | |
33dc9b12 SR |
1399 | } |
1400 | ||
b848914c SR |
1401 | /* |
1402 | * Test the hashes for this ops to see if we want to call | |
1403 | * the ops->func or not. | |
1404 | * | |
1405 | * It's a match if the ip is in the ops->filter_hash or | |
1406 | * the filter_hash does not exist or is empty, | |
1407 | * AND | |
1408 | * the ip is not in the ops->notrace_hash. | |
cdbe61bf SR |
1409 | * |
1410 | * This needs to be called with preemption disabled as | |
1411 | * the hashes are freed with call_rcu_sched(). | |
b848914c SR |
1412 | */ |
1413 | static int | |
1414 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip) | |
1415 | { | |
1416 | struct ftrace_hash *filter_hash; | |
1417 | struct ftrace_hash *notrace_hash; | |
1418 | int ret; | |
1419 | ||
b848914c SR |
1420 | filter_hash = rcu_dereference_raw(ops->filter_hash); |
1421 | notrace_hash = rcu_dereference_raw(ops->notrace_hash); | |
1422 | ||
06a51d93 | 1423 | if ((ftrace_hash_empty(filter_hash) || |
b848914c | 1424 | ftrace_lookup_ip(filter_hash, ip)) && |
06a51d93 | 1425 | (ftrace_hash_empty(notrace_hash) || |
b848914c SR |
1426 | !ftrace_lookup_ip(notrace_hash, ip))) |
1427 | ret = 1; | |
1428 | else | |
1429 | ret = 0; | |
b848914c SR |
1430 | |
1431 | return ret; | |
1432 | } | |
1433 | ||
493762fc SR |
1434 | /* |
1435 | * This is a double for. Do not use 'break' to break out of the loop, | |
1436 | * you must use a goto. | |
1437 | */ | |
1438 | #define do_for_each_ftrace_rec(pg, rec) \ | |
1439 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ | |
1440 | int _____i; \ | |
1441 | for (_____i = 0; _____i < pg->index; _____i++) { \ | |
1442 | rec = &pg->records[_____i]; | |
1443 | ||
1444 | #define while_for_each_ftrace_rec() \ | |
1445 | } \ | |
1446 | } | |
1447 | ||
5855fead SR |
1448 | |
1449 | static int ftrace_cmp_recs(const void *a, const void *b) | |
1450 | { | |
a650e02a SR |
1451 | const struct dyn_ftrace *key = a; |
1452 | const struct dyn_ftrace *rec = b; | |
5855fead | 1453 | |
a650e02a | 1454 | if (key->flags < rec->ip) |
5855fead | 1455 | return -1; |
a650e02a SR |
1456 | if (key->ip >= rec->ip + MCOUNT_INSN_SIZE) |
1457 | return 1; | |
5855fead SR |
1458 | return 0; |
1459 | } | |
1460 | ||
f0cf973a | 1461 | static unsigned long ftrace_location_range(unsigned long start, unsigned long end) |
c88fd863 SR |
1462 | { |
1463 | struct ftrace_page *pg; | |
1464 | struct dyn_ftrace *rec; | |
5855fead | 1465 | struct dyn_ftrace key; |
c88fd863 | 1466 | |
a650e02a SR |
1467 | key.ip = start; |
1468 | key.flags = end; /* overload flags, as it is unsigned long */ | |
5855fead SR |
1469 | |
1470 | for (pg = ftrace_pages_start; pg; pg = pg->next) { | |
a650e02a SR |
1471 | if (end < pg->records[0].ip || |
1472 | start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE)) | |
9644302e | 1473 | continue; |
5855fead SR |
1474 | rec = bsearch(&key, pg->records, pg->index, |
1475 | sizeof(struct dyn_ftrace), | |
1476 | ftrace_cmp_recs); | |
1477 | if (rec) | |
f0cf973a | 1478 | return rec->ip; |
5855fead | 1479 | } |
c88fd863 SR |
1480 | |
1481 | return 0; | |
1482 | } | |
1483 | ||
a650e02a SR |
1484 | /** |
1485 | * ftrace_location - return true if the ip giving is a traced location | |
1486 | * @ip: the instruction pointer to check | |
1487 | * | |
f0cf973a | 1488 | * Returns rec->ip if @ip given is a pointer to a ftrace location. |
a650e02a SR |
1489 | * That is, the instruction that is either a NOP or call to |
1490 | * the function tracer. It checks the ftrace internal tables to | |
1491 | * determine if the address belongs or not. | |
1492 | */ | |
f0cf973a | 1493 | unsigned long ftrace_location(unsigned long ip) |
a650e02a SR |
1494 | { |
1495 | return ftrace_location_range(ip, ip); | |
1496 | } | |
1497 | ||
1498 | /** | |
1499 | * ftrace_text_reserved - return true if range contains an ftrace location | |
1500 | * @start: start of range to search | |
1501 | * @end: end of range to search (inclusive). @end points to the last byte to check. | |
1502 | * | |
1503 | * Returns 1 if @start and @end contains a ftrace location. | |
1504 | * That is, the instruction that is either a NOP or call to | |
1505 | * the function tracer. It checks the ftrace internal tables to | |
1506 | * determine if the address belongs or not. | |
1507 | */ | |
1508 | int ftrace_text_reserved(void *start, void *end) | |
1509 | { | |
f0cf973a SR |
1510 | unsigned long ret; |
1511 | ||
1512 | ret = ftrace_location_range((unsigned long)start, | |
1513 | (unsigned long)end); | |
1514 | ||
1515 | return (int)!!ret; | |
a650e02a SR |
1516 | } |
1517 | ||
ed926f9b SR |
1518 | static void __ftrace_hash_rec_update(struct ftrace_ops *ops, |
1519 | int filter_hash, | |
1520 | bool inc) | |
1521 | { | |
1522 | struct ftrace_hash *hash; | |
1523 | struct ftrace_hash *other_hash; | |
1524 | struct ftrace_page *pg; | |
1525 | struct dyn_ftrace *rec; | |
1526 | int count = 0; | |
1527 | int all = 0; | |
1528 | ||
1529 | /* Only update if the ops has been registered */ | |
1530 | if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) | |
1531 | return; | |
1532 | ||
1533 | /* | |
1534 | * In the filter_hash case: | |
1535 | * If the count is zero, we update all records. | |
1536 | * Otherwise we just update the items in the hash. | |
1537 | * | |
1538 | * In the notrace_hash case: | |
1539 | * We enable the update in the hash. | |
1540 | * As disabling notrace means enabling the tracing, | |
1541 | * and enabling notrace means disabling, the inc variable | |
1542 | * gets inversed. | |
1543 | */ | |
1544 | if (filter_hash) { | |
1545 | hash = ops->filter_hash; | |
1546 | other_hash = ops->notrace_hash; | |
06a51d93 | 1547 | if (ftrace_hash_empty(hash)) |
ed926f9b SR |
1548 | all = 1; |
1549 | } else { | |
1550 | inc = !inc; | |
1551 | hash = ops->notrace_hash; | |
1552 | other_hash = ops->filter_hash; | |
1553 | /* | |
1554 | * If the notrace hash has no items, | |
1555 | * then there's nothing to do. | |
1556 | */ | |
06a51d93 | 1557 | if (ftrace_hash_empty(hash)) |
ed926f9b SR |
1558 | return; |
1559 | } | |
1560 | ||
1561 | do_for_each_ftrace_rec(pg, rec) { | |
1562 | int in_other_hash = 0; | |
1563 | int in_hash = 0; | |
1564 | int match = 0; | |
1565 | ||
1566 | if (all) { | |
1567 | /* | |
1568 | * Only the filter_hash affects all records. | |
1569 | * Update if the record is not in the notrace hash. | |
1570 | */ | |
b848914c | 1571 | if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) |
ed926f9b SR |
1572 | match = 1; |
1573 | } else { | |
06a51d93 SR |
1574 | in_hash = !!ftrace_lookup_ip(hash, rec->ip); |
1575 | in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip); | |
ed926f9b SR |
1576 | |
1577 | /* | |
1578 | * | |
1579 | */ | |
1580 | if (filter_hash && in_hash && !in_other_hash) | |
1581 | match = 1; | |
1582 | else if (!filter_hash && in_hash && | |
06a51d93 | 1583 | (in_other_hash || ftrace_hash_empty(other_hash))) |
ed926f9b SR |
1584 | match = 1; |
1585 | } | |
1586 | if (!match) | |
1587 | continue; | |
1588 | ||
1589 | if (inc) { | |
1590 | rec->flags++; | |
1591 | if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == FTRACE_REF_MAX)) | |
1592 | return; | |
08f6fba5 SR |
1593 | /* |
1594 | * If any ops wants regs saved for this function | |
1595 | * then all ops will get saved regs. | |
1596 | */ | |
1597 | if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) | |
1598 | rec->flags |= FTRACE_FL_REGS; | |
ed926f9b SR |
1599 | } else { |
1600 | if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == 0)) | |
1601 | return; | |
1602 | rec->flags--; | |
1603 | } | |
1604 | count++; | |
1605 | /* Shortcut, if we handled all records, we are done. */ | |
1606 | if (!all && count == hash->count) | |
1607 | return; | |
1608 | } while_for_each_ftrace_rec(); | |
1609 | } | |
1610 | ||
1611 | static void ftrace_hash_rec_disable(struct ftrace_ops *ops, | |
1612 | int filter_hash) | |
1613 | { | |
1614 | __ftrace_hash_rec_update(ops, filter_hash, 0); | |
1615 | } | |
1616 | ||
1617 | static void ftrace_hash_rec_enable(struct ftrace_ops *ops, | |
1618 | int filter_hash) | |
1619 | { | |
1620 | __ftrace_hash_rec_update(ops, filter_hash, 1); | |
1621 | } | |
1622 | ||
b17e8a37 SR |
1623 | static void print_ip_ins(const char *fmt, unsigned char *p) |
1624 | { | |
1625 | int i; | |
1626 | ||
1627 | printk(KERN_CONT "%s", fmt); | |
1628 | ||
1629 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) | |
1630 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); | |
1631 | } | |
1632 | ||
c88fd863 SR |
1633 | /** |
1634 | * ftrace_bug - report and shutdown function tracer | |
1635 | * @failed: The failed type (EFAULT, EINVAL, EPERM) | |
1636 | * @ip: The address that failed | |
1637 | * | |
1638 | * The arch code that enables or disables the function tracing | |
1639 | * can call ftrace_bug() when it has detected a problem in | |
1640 | * modifying the code. @failed should be one of either: | |
1641 | * EFAULT - if the problem happens on reading the @ip address | |
1642 | * EINVAL - if what is read at @ip is not what was expected | |
1643 | * EPERM - if the problem happens on writting to the @ip address | |
1644 | */ | |
1645 | void ftrace_bug(int failed, unsigned long ip) | |
b17e8a37 SR |
1646 | { |
1647 | switch (failed) { | |
1648 | case -EFAULT: | |
1649 | FTRACE_WARN_ON_ONCE(1); | |
1650 | pr_info("ftrace faulted on modifying "); | |
1651 | print_ip_sym(ip); | |
1652 | break; | |
1653 | case -EINVAL: | |
1654 | FTRACE_WARN_ON_ONCE(1); | |
1655 | pr_info("ftrace failed to modify "); | |
1656 | print_ip_sym(ip); | |
b17e8a37 | 1657 | print_ip_ins(" actual: ", (unsigned char *)ip); |
b17e8a37 SR |
1658 | printk(KERN_CONT "\n"); |
1659 | break; | |
1660 | case -EPERM: | |
1661 | FTRACE_WARN_ON_ONCE(1); | |
1662 | pr_info("ftrace faulted on writing "); | |
1663 | print_ip_sym(ip); | |
1664 | break; | |
1665 | default: | |
1666 | FTRACE_WARN_ON_ONCE(1); | |
1667 | pr_info("ftrace faulted on unknown error "); | |
1668 | print_ip_sym(ip); | |
1669 | } | |
1670 | } | |
1671 | ||
c88fd863 | 1672 | static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update) |
5072c59f | 1673 | { |
64fbcd16 | 1674 | unsigned long flag = 0UL; |
e7d3737e | 1675 | |
982c350b | 1676 | /* |
30fb6aa7 | 1677 | * If we are updating calls: |
982c350b | 1678 | * |
ed926f9b SR |
1679 | * If the record has a ref count, then we need to enable it |
1680 | * because someone is using it. | |
982c350b | 1681 | * |
ed926f9b SR |
1682 | * Otherwise we make sure its disabled. |
1683 | * | |
30fb6aa7 | 1684 | * If we are disabling calls, then disable all records that |
ed926f9b | 1685 | * are enabled. |
982c350b | 1686 | */ |
c88fd863 | 1687 | if (enable && (rec->flags & ~FTRACE_FL_MASK)) |
ed926f9b | 1688 | flag = FTRACE_FL_ENABLED; |
982c350b | 1689 | |
08f6fba5 SR |
1690 | /* |
1691 | * If enabling and the REGS flag does not match the REGS_EN, then | |
1692 | * do not ignore this record. Set flags to fail the compare against | |
1693 | * ENABLED. | |
1694 | */ | |
1695 | if (flag && | |
1696 | (!(rec->flags & FTRACE_FL_REGS) != !(rec->flags & FTRACE_FL_REGS_EN))) | |
1697 | flag |= FTRACE_FL_REGS; | |
1698 | ||
64fbcd16 XG |
1699 | /* If the state of this record hasn't changed, then do nothing */ |
1700 | if ((rec->flags & FTRACE_FL_ENABLED) == flag) | |
c88fd863 | 1701 | return FTRACE_UPDATE_IGNORE; |
982c350b | 1702 | |
64fbcd16 | 1703 | if (flag) { |
08f6fba5 SR |
1704 | /* Save off if rec is being enabled (for return value) */ |
1705 | flag ^= rec->flags & FTRACE_FL_ENABLED; | |
1706 | ||
1707 | if (update) { | |
c88fd863 | 1708 | rec->flags |= FTRACE_FL_ENABLED; |
08f6fba5 SR |
1709 | if (flag & FTRACE_FL_REGS) { |
1710 | if (rec->flags & FTRACE_FL_REGS) | |
1711 | rec->flags |= FTRACE_FL_REGS_EN; | |
1712 | else | |
1713 | rec->flags &= ~FTRACE_FL_REGS_EN; | |
1714 | } | |
1715 | } | |
1716 | ||
1717 | /* | |
1718 | * If this record is being updated from a nop, then | |
1719 | * return UPDATE_MAKE_CALL. | |
1720 | * Otherwise, if the EN flag is set, then return | |
1721 | * UPDATE_MODIFY_CALL_REGS to tell the caller to convert | |
1722 | * from the non-save regs, to a save regs function. | |
1723 | * Otherwise, | |
1724 | * return UPDATE_MODIFY_CALL to tell the caller to convert | |
1725 | * from the save regs, to a non-save regs function. | |
1726 | */ | |
1727 | if (flag & FTRACE_FL_ENABLED) | |
1728 | return FTRACE_UPDATE_MAKE_CALL; | |
1729 | else if (rec->flags & FTRACE_FL_REGS_EN) | |
1730 | return FTRACE_UPDATE_MODIFY_CALL_REGS; | |
1731 | else | |
1732 | return FTRACE_UPDATE_MODIFY_CALL; | |
c88fd863 SR |
1733 | } |
1734 | ||
08f6fba5 SR |
1735 | if (update) { |
1736 | /* If there's no more users, clear all flags */ | |
1737 | if (!(rec->flags & ~FTRACE_FL_MASK)) | |
1738 | rec->flags = 0; | |
1739 | else | |
1740 | /* Just disable the record (keep REGS state) */ | |
1741 | rec->flags &= ~FTRACE_FL_ENABLED; | |
1742 | } | |
c88fd863 SR |
1743 | |
1744 | return FTRACE_UPDATE_MAKE_NOP; | |
1745 | } | |
1746 | ||
1747 | /** | |
1748 | * ftrace_update_record, set a record that now is tracing or not | |
1749 | * @rec: the record to update | |
1750 | * @enable: set to 1 if the record is tracing, zero to force disable | |
1751 | * | |
1752 | * The records that represent all functions that can be traced need | |
1753 | * to be updated when tracing has been enabled. | |
1754 | */ | |
1755 | int ftrace_update_record(struct dyn_ftrace *rec, int enable) | |
1756 | { | |
1757 | return ftrace_check_record(rec, enable, 1); | |
1758 | } | |
1759 | ||
1760 | /** | |
1761 | * ftrace_test_record, check if the record has been enabled or not | |
1762 | * @rec: the record to test | |
1763 | * @enable: set to 1 to check if enabled, 0 if it is disabled | |
1764 | * | |
1765 | * The arch code may need to test if a record is already set to | |
1766 | * tracing to determine how to modify the function code that it | |
1767 | * represents. | |
1768 | */ | |
1769 | int ftrace_test_record(struct dyn_ftrace *rec, int enable) | |
1770 | { | |
1771 | return ftrace_check_record(rec, enable, 0); | |
1772 | } | |
1773 | ||
1774 | static int | |
1775 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) | |
1776 | { | |
08f6fba5 | 1777 | unsigned long ftrace_old_addr; |
c88fd863 SR |
1778 | unsigned long ftrace_addr; |
1779 | int ret; | |
1780 | ||
c88fd863 SR |
1781 | ret = ftrace_update_record(rec, enable); |
1782 | ||
08f6fba5 SR |
1783 | if (rec->flags & FTRACE_FL_REGS) |
1784 | ftrace_addr = (unsigned long)FTRACE_REGS_ADDR; | |
1785 | else | |
1786 | ftrace_addr = (unsigned long)FTRACE_ADDR; | |
1787 | ||
c88fd863 SR |
1788 | switch (ret) { |
1789 | case FTRACE_UPDATE_IGNORE: | |
1790 | return 0; | |
1791 | ||
1792 | case FTRACE_UPDATE_MAKE_CALL: | |
64fbcd16 | 1793 | return ftrace_make_call(rec, ftrace_addr); |
c88fd863 SR |
1794 | |
1795 | case FTRACE_UPDATE_MAKE_NOP: | |
1796 | return ftrace_make_nop(NULL, rec, ftrace_addr); | |
08f6fba5 SR |
1797 | |
1798 | case FTRACE_UPDATE_MODIFY_CALL_REGS: | |
1799 | case FTRACE_UPDATE_MODIFY_CALL: | |
1800 | if (rec->flags & FTRACE_FL_REGS) | |
1801 | ftrace_old_addr = (unsigned long)FTRACE_ADDR; | |
1802 | else | |
1803 | ftrace_old_addr = (unsigned long)FTRACE_REGS_ADDR; | |
1804 | ||
1805 | return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr); | |
5072c59f SR |
1806 | } |
1807 | ||
c88fd863 | 1808 | return -1; /* unknow ftrace bug */ |
5072c59f SR |
1809 | } |
1810 | ||
e4f5d544 | 1811 | void __weak ftrace_replace_code(int enable) |
3c1720f0 | 1812 | { |
3c1720f0 SR |
1813 | struct dyn_ftrace *rec; |
1814 | struct ftrace_page *pg; | |
6a24a244 | 1815 | int failed; |
3c1720f0 | 1816 | |
45a4a237 SR |
1817 | if (unlikely(ftrace_disabled)) |
1818 | return; | |
1819 | ||
265c831c | 1820 | do_for_each_ftrace_rec(pg, rec) { |
e4f5d544 | 1821 | failed = __ftrace_replace_code(rec, enable); |
fa9d13cf | 1822 | if (failed) { |
3279ba37 SR |
1823 | ftrace_bug(failed, rec->ip); |
1824 | /* Stop processing */ | |
1825 | return; | |
3c1720f0 | 1826 | } |
265c831c | 1827 | } while_for_each_ftrace_rec(); |
3c1720f0 SR |
1828 | } |
1829 | ||
c88fd863 SR |
1830 | struct ftrace_rec_iter { |
1831 | struct ftrace_page *pg; | |
1832 | int index; | |
1833 | }; | |
1834 | ||
1835 | /** | |
1836 | * ftrace_rec_iter_start, start up iterating over traced functions | |
1837 | * | |
1838 | * Returns an iterator handle that is used to iterate over all | |
1839 | * the records that represent address locations where functions | |
1840 | * are traced. | |
1841 | * | |
1842 | * May return NULL if no records are available. | |
1843 | */ | |
1844 | struct ftrace_rec_iter *ftrace_rec_iter_start(void) | |
1845 | { | |
1846 | /* | |
1847 | * We only use a single iterator. | |
1848 | * Protected by the ftrace_lock mutex. | |
1849 | */ | |
1850 | static struct ftrace_rec_iter ftrace_rec_iter; | |
1851 | struct ftrace_rec_iter *iter = &ftrace_rec_iter; | |
1852 | ||
1853 | iter->pg = ftrace_pages_start; | |
1854 | iter->index = 0; | |
1855 | ||
1856 | /* Could have empty pages */ | |
1857 | while (iter->pg && !iter->pg->index) | |
1858 | iter->pg = iter->pg->next; | |
1859 | ||
1860 | if (!iter->pg) | |
1861 | return NULL; | |
1862 | ||
1863 | return iter; | |
1864 | } | |
1865 | ||
1866 | /** | |
1867 | * ftrace_rec_iter_next, get the next record to process. | |
1868 | * @iter: The handle to the iterator. | |
1869 | * | |
1870 | * Returns the next iterator after the given iterator @iter. | |
1871 | */ | |
1872 | struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter) | |
1873 | { | |
1874 | iter->index++; | |
1875 | ||
1876 | if (iter->index >= iter->pg->index) { | |
1877 | iter->pg = iter->pg->next; | |
1878 | iter->index = 0; | |
1879 | ||
1880 | /* Could have empty pages */ | |
1881 | while (iter->pg && !iter->pg->index) | |
1882 | iter->pg = iter->pg->next; | |
1883 | } | |
1884 | ||
1885 | if (!iter->pg) | |
1886 | return NULL; | |
1887 | ||
1888 | return iter; | |
1889 | } | |
1890 | ||
1891 | /** | |
1892 | * ftrace_rec_iter_record, get the record at the iterator location | |
1893 | * @iter: The current iterator location | |
1894 | * | |
1895 | * Returns the record that the current @iter is at. | |
1896 | */ | |
1897 | struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter) | |
1898 | { | |
1899 | return &iter->pg->records[iter->index]; | |
1900 | } | |
1901 | ||
492a7ea5 | 1902 | static int |
31e88909 | 1903 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
3c1720f0 SR |
1904 | { |
1905 | unsigned long ip; | |
593eb8a2 | 1906 | int ret; |
3c1720f0 SR |
1907 | |
1908 | ip = rec->ip; | |
1909 | ||
45a4a237 SR |
1910 | if (unlikely(ftrace_disabled)) |
1911 | return 0; | |
1912 | ||
25aac9dc | 1913 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
593eb8a2 | 1914 | if (ret) { |
31e88909 | 1915 | ftrace_bug(ret, ip); |
492a7ea5 | 1916 | return 0; |
37ad5084 | 1917 | } |
492a7ea5 | 1918 | return 1; |
3c1720f0 SR |
1919 | } |
1920 | ||
000ab691 SR |
1921 | /* |
1922 | * archs can override this function if they must do something | |
1923 | * before the modifying code is performed. | |
1924 | */ | |
1925 | int __weak ftrace_arch_code_modify_prepare(void) | |
1926 | { | |
1927 | return 0; | |
1928 | } | |
1929 | ||
1930 | /* | |
1931 | * archs can override this function if they must do something | |
1932 | * after the modifying code is performed. | |
1933 | */ | |
1934 | int __weak ftrace_arch_code_modify_post_process(void) | |
1935 | { | |
1936 | return 0; | |
1937 | } | |
1938 | ||
8ed3e2cf | 1939 | void ftrace_modify_all_code(int command) |
3d083395 | 1940 | { |
8ed3e2cf | 1941 | if (command & FTRACE_UPDATE_CALLS) |
d61f82d0 | 1942 | ftrace_replace_code(1); |
8ed3e2cf | 1943 | else if (command & FTRACE_DISABLE_CALLS) |
d61f82d0 SR |
1944 | ftrace_replace_code(0); |
1945 | ||
8ed3e2cf | 1946 | if (command & FTRACE_UPDATE_TRACE_FUNC) |
d61f82d0 SR |
1947 | ftrace_update_ftrace_func(ftrace_trace_function); |
1948 | ||
8ed3e2cf | 1949 | if (command & FTRACE_START_FUNC_RET) |
5a45cfe1 | 1950 | ftrace_enable_ftrace_graph_caller(); |
8ed3e2cf | 1951 | else if (command & FTRACE_STOP_FUNC_RET) |
5a45cfe1 | 1952 | ftrace_disable_ftrace_graph_caller(); |
8ed3e2cf SR |
1953 | } |
1954 | ||
1955 | static int __ftrace_modify_code(void *data) | |
1956 | { | |
1957 | int *command = data; | |
1958 | ||
1959 | ftrace_modify_all_code(*command); | |
5a45cfe1 | 1960 | |
d61f82d0 | 1961 | return 0; |
3d083395 SR |
1962 | } |
1963 | ||
c88fd863 SR |
1964 | /** |
1965 | * ftrace_run_stop_machine, go back to the stop machine method | |
1966 | * @command: The command to tell ftrace what to do | |
1967 | * | |
1968 | * If an arch needs to fall back to the stop machine method, the | |
1969 | * it can call this function. | |
1970 | */ | |
1971 | void ftrace_run_stop_machine(int command) | |
1972 | { | |
1973 | stop_machine(__ftrace_modify_code, &command, NULL); | |
1974 | } | |
1975 | ||
1976 | /** | |
1977 | * arch_ftrace_update_code, modify the code to trace or not trace | |
1978 | * @command: The command that needs to be done | |
1979 | * | |
1980 | * Archs can override this function if it does not need to | |
1981 | * run stop_machine() to modify code. | |
1982 | */ | |
1983 | void __weak arch_ftrace_update_code(int command) | |
1984 | { | |
1985 | ftrace_run_stop_machine(command); | |
1986 | } | |
1987 | ||
e309b41d | 1988 | static void ftrace_run_update_code(int command) |
3d083395 | 1989 | { |
000ab691 SR |
1990 | int ret; |
1991 | ||
1992 | ret = ftrace_arch_code_modify_prepare(); | |
1993 | FTRACE_WARN_ON(ret); | |
1994 | if (ret) | |
1995 | return; | |
c88fd863 SR |
1996 | /* |
1997 | * Do not call function tracer while we update the code. | |
1998 | * We are in stop machine. | |
1999 | */ | |
2000 | function_trace_stop++; | |
000ab691 | 2001 | |
c88fd863 SR |
2002 | /* |
2003 | * By default we use stop_machine() to modify the code. | |
2004 | * But archs can do what ever they want as long as it | |
2005 | * is safe. The stop_machine() is the safest, but also | |
2006 | * produces the most overhead. | |
2007 | */ | |
2008 | arch_ftrace_update_code(command); | |
2009 | ||
c88fd863 | 2010 | function_trace_stop--; |
000ab691 SR |
2011 | |
2012 | ret = ftrace_arch_code_modify_post_process(); | |
2013 | FTRACE_WARN_ON(ret); | |
3d083395 SR |
2014 | } |
2015 | ||
d61f82d0 | 2016 | static ftrace_func_t saved_ftrace_func; |
60a7ecf4 | 2017 | static int ftrace_start_up; |
b848914c | 2018 | static int global_start_up; |
df4fc315 SR |
2019 | |
2020 | static void ftrace_startup_enable(int command) | |
2021 | { | |
2022 | if (saved_ftrace_func != ftrace_trace_function) { | |
2023 | saved_ftrace_func = ftrace_trace_function; | |
2024 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2025 | } | |
2026 | ||
2027 | if (!command || !ftrace_enabled) | |
2028 | return; | |
2029 | ||
2030 | ftrace_run_update_code(command); | |
2031 | } | |
d61f82d0 | 2032 | |
a1cd6173 | 2033 | static int ftrace_startup(struct ftrace_ops *ops, int command) |
3d083395 | 2034 | { |
b848914c SR |
2035 | bool hash_enable = true; |
2036 | ||
4eebcc81 | 2037 | if (unlikely(ftrace_disabled)) |
a1cd6173 | 2038 | return -ENODEV; |
4eebcc81 | 2039 | |
60a7ecf4 | 2040 | ftrace_start_up++; |
30fb6aa7 | 2041 | command |= FTRACE_UPDATE_CALLS; |
d61f82d0 | 2042 | |
b848914c SR |
2043 | /* ops marked global share the filter hashes */ |
2044 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { | |
2045 | ops = &global_ops; | |
2046 | /* Don't update hash if global is already set */ | |
2047 | if (global_start_up) | |
2048 | hash_enable = false; | |
2049 | global_start_up++; | |
2050 | } | |
2051 | ||
ed926f9b | 2052 | ops->flags |= FTRACE_OPS_FL_ENABLED; |
b848914c | 2053 | if (hash_enable) |
ed926f9b SR |
2054 | ftrace_hash_rec_enable(ops, 1); |
2055 | ||
df4fc315 | 2056 | ftrace_startup_enable(command); |
a1cd6173 SR |
2057 | |
2058 | return 0; | |
3d083395 SR |
2059 | } |
2060 | ||
bd69c30b | 2061 | static void ftrace_shutdown(struct ftrace_ops *ops, int command) |
3d083395 | 2062 | { |
b848914c SR |
2063 | bool hash_disable = true; |
2064 | ||
4eebcc81 SR |
2065 | if (unlikely(ftrace_disabled)) |
2066 | return; | |
2067 | ||
60a7ecf4 | 2068 | ftrace_start_up--; |
9ea1a153 FW |
2069 | /* |
2070 | * Just warn in case of unbalance, no need to kill ftrace, it's not | |
2071 | * critical but the ftrace_call callers may be never nopped again after | |
2072 | * further ftrace uses. | |
2073 | */ | |
2074 | WARN_ON_ONCE(ftrace_start_up < 0); | |
2075 | ||
b848914c SR |
2076 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) { |
2077 | ops = &global_ops; | |
2078 | global_start_up--; | |
2079 | WARN_ON_ONCE(global_start_up < 0); | |
2080 | /* Don't update hash if global still has users */ | |
2081 | if (global_start_up) { | |
2082 | WARN_ON_ONCE(!ftrace_start_up); | |
2083 | hash_disable = false; | |
2084 | } | |
2085 | } | |
2086 | ||
2087 | if (hash_disable) | |
ed926f9b SR |
2088 | ftrace_hash_rec_disable(ops, 1); |
2089 | ||
b848914c | 2090 | if (ops != &global_ops || !global_start_up) |
ed926f9b | 2091 | ops->flags &= ~FTRACE_OPS_FL_ENABLED; |
b848914c | 2092 | |
30fb6aa7 | 2093 | command |= FTRACE_UPDATE_CALLS; |
3d083395 | 2094 | |
d61f82d0 SR |
2095 | if (saved_ftrace_func != ftrace_trace_function) { |
2096 | saved_ftrace_func = ftrace_trace_function; | |
2097 | command |= FTRACE_UPDATE_TRACE_FUNC; | |
2098 | } | |
3d083395 | 2099 | |
d61f82d0 | 2100 | if (!command || !ftrace_enabled) |
e6ea44e9 | 2101 | return; |
d61f82d0 SR |
2102 | |
2103 | ftrace_run_update_code(command); | |
3d083395 SR |
2104 | } |
2105 | ||
e309b41d | 2106 | static void ftrace_startup_sysctl(void) |
b0fc494f | 2107 | { |
4eebcc81 SR |
2108 | if (unlikely(ftrace_disabled)) |
2109 | return; | |
2110 | ||
d61f82d0 SR |
2111 | /* Force update next time */ |
2112 | saved_ftrace_func = NULL; | |
60a7ecf4 SR |
2113 | /* ftrace_start_up is true if we want ftrace running */ |
2114 | if (ftrace_start_up) | |
30fb6aa7 | 2115 | ftrace_run_update_code(FTRACE_UPDATE_CALLS); |
b0fc494f SR |
2116 | } |
2117 | ||
e309b41d | 2118 | static void ftrace_shutdown_sysctl(void) |
b0fc494f | 2119 | { |
4eebcc81 SR |
2120 | if (unlikely(ftrace_disabled)) |
2121 | return; | |
2122 | ||
60a7ecf4 SR |
2123 | /* ftrace_start_up is true if ftrace is running */ |
2124 | if (ftrace_start_up) | |
79e406d7 | 2125 | ftrace_run_update_code(FTRACE_DISABLE_CALLS); |
b0fc494f SR |
2126 | } |
2127 | ||
3d083395 SR |
2128 | static cycle_t ftrace_update_time; |
2129 | static unsigned long ftrace_update_cnt; | |
2130 | unsigned long ftrace_update_tot_cnt; | |
2131 | ||
f7bc8b61 SR |
2132 | static int ops_traces_mod(struct ftrace_ops *ops) |
2133 | { | |
2134 | struct ftrace_hash *hash; | |
2135 | ||
2136 | hash = ops->filter_hash; | |
06a51d93 | 2137 | return ftrace_hash_empty(hash); |
f7bc8b61 SR |
2138 | } |
2139 | ||
31e88909 | 2140 | static int ftrace_update_code(struct module *mod) |
3d083395 | 2141 | { |
85ae32ae | 2142 | struct ftrace_page *pg; |
e94142a6 | 2143 | struct dyn_ftrace *p; |
f22f9a89 | 2144 | cycle_t start, stop; |
f7bc8b61 | 2145 | unsigned long ref = 0; |
85ae32ae | 2146 | int i; |
f7bc8b61 SR |
2147 | |
2148 | /* | |
2149 | * When adding a module, we need to check if tracers are | |
2150 | * currently enabled and if they are set to trace all functions. | |
2151 | * If they are, we need to enable the module functions as well | |
2152 | * as update the reference counts for those function records. | |
2153 | */ | |
2154 | if (mod) { | |
2155 | struct ftrace_ops *ops; | |
2156 | ||
2157 | for (ops = ftrace_ops_list; | |
2158 | ops != &ftrace_list_end; ops = ops->next) { | |
2159 | if (ops->flags & FTRACE_OPS_FL_ENABLED && | |
2160 | ops_traces_mod(ops)) | |
2161 | ref++; | |
2162 | } | |
2163 | } | |
3d083395 | 2164 | |
750ed1a4 | 2165 | start = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
2166 | ftrace_update_cnt = 0; |
2167 | ||
85ae32ae | 2168 | for (pg = ftrace_new_pgs; pg; pg = pg->next) { |
3d083395 | 2169 | |
85ae32ae SR |
2170 | for (i = 0; i < pg->index; i++) { |
2171 | /* If something went wrong, bail without enabling anything */ | |
2172 | if (unlikely(ftrace_disabled)) | |
2173 | return -1; | |
f22f9a89 | 2174 | |
85ae32ae SR |
2175 | p = &pg->records[i]; |
2176 | p->flags = ref; | |
f22f9a89 | 2177 | |
85ae32ae SR |
2178 | /* |
2179 | * Do the initial record conversion from mcount jump | |
2180 | * to the NOP instructions. | |
2181 | */ | |
2182 | if (!ftrace_code_disable(mod, p)) | |
2183 | break; | |
5cb084bb | 2184 | |
85ae32ae | 2185 | ftrace_update_cnt++; |
5cb084bb | 2186 | |
85ae32ae SR |
2187 | /* |
2188 | * If the tracing is enabled, go ahead and enable the record. | |
2189 | * | |
2190 | * The reason not to enable the record immediatelly is the | |
2191 | * inherent check of ftrace_make_nop/ftrace_make_call for | |
2192 | * correct previous instructions. Making first the NOP | |
2193 | * conversion puts the module to the correct state, thus | |
2194 | * passing the ftrace_make_call check. | |
2195 | */ | |
2196 | if (ftrace_start_up && ref) { | |
2197 | int failed = __ftrace_replace_code(p, 1); | |
2198 | if (failed) | |
2199 | ftrace_bug(failed, p->ip); | |
2200 | } | |
5cb084bb | 2201 | } |
3d083395 SR |
2202 | } |
2203 | ||
85ae32ae SR |
2204 | ftrace_new_pgs = NULL; |
2205 | ||
750ed1a4 | 2206 | stop = ftrace_now(raw_smp_processor_id()); |
3d083395 SR |
2207 | ftrace_update_time = stop - start; |
2208 | ftrace_update_tot_cnt += ftrace_update_cnt; | |
2209 | ||
16444a8a ACM |
2210 | return 0; |
2211 | } | |
2212 | ||
a7900875 | 2213 | static int ftrace_allocate_records(struct ftrace_page *pg, int count) |
3c1720f0 | 2214 | { |
a7900875 | 2215 | int order; |
3c1720f0 | 2216 | int cnt; |
3c1720f0 | 2217 | |
a7900875 SR |
2218 | if (WARN_ON(!count)) |
2219 | return -EINVAL; | |
2220 | ||
2221 | order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE)); | |
3c1720f0 SR |
2222 | |
2223 | /* | |
a7900875 SR |
2224 | * We want to fill as much as possible. No more than a page |
2225 | * may be empty. | |
3c1720f0 | 2226 | */ |
a7900875 SR |
2227 | while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE) |
2228 | order--; | |
3c1720f0 | 2229 | |
a7900875 SR |
2230 | again: |
2231 | pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order); | |
3c1720f0 | 2232 | |
a7900875 SR |
2233 | if (!pg->records) { |
2234 | /* if we can't allocate this size, try something smaller */ | |
2235 | if (!order) | |
2236 | return -ENOMEM; | |
2237 | order >>= 1; | |
2238 | goto again; | |
2239 | } | |
3c1720f0 | 2240 | |
a7900875 SR |
2241 | cnt = (PAGE_SIZE << order) / ENTRY_SIZE; |
2242 | pg->size = cnt; | |
3c1720f0 | 2243 | |
a7900875 SR |
2244 | if (cnt > count) |
2245 | cnt = count; | |
2246 | ||
2247 | return cnt; | |
2248 | } | |
2249 | ||
2250 | static struct ftrace_page * | |
2251 | ftrace_allocate_pages(unsigned long num_to_init) | |
2252 | { | |
2253 | struct ftrace_page *start_pg; | |
2254 | struct ftrace_page *pg; | |
2255 | int order; | |
2256 | int cnt; | |
2257 | ||
2258 | if (!num_to_init) | |
2259 | return 0; | |
2260 | ||
2261 | start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL); | |
2262 | if (!pg) | |
2263 | return NULL; | |
2264 | ||
2265 | /* | |
2266 | * Try to allocate as much as possible in one continues | |
2267 | * location that fills in all of the space. We want to | |
2268 | * waste as little space as possible. | |
2269 | */ | |
2270 | for (;;) { | |
2271 | cnt = ftrace_allocate_records(pg, num_to_init); | |
2272 | if (cnt < 0) | |
2273 | goto free_pages; | |
2274 | ||
2275 | num_to_init -= cnt; | |
2276 | if (!num_to_init) | |
3c1720f0 SR |
2277 | break; |
2278 | ||
a7900875 SR |
2279 | pg->next = kzalloc(sizeof(*pg), GFP_KERNEL); |
2280 | if (!pg->next) | |
2281 | goto free_pages; | |
2282 | ||
3c1720f0 SR |
2283 | pg = pg->next; |
2284 | } | |
2285 | ||
a7900875 SR |
2286 | return start_pg; |
2287 | ||
2288 | free_pages: | |
2289 | while (start_pg) { | |
2290 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); | |
2291 | free_pages((unsigned long)pg->records, order); | |
2292 | start_pg = pg->next; | |
2293 | kfree(pg); | |
2294 | pg = start_pg; | |
2295 | } | |
2296 | pr_info("ftrace: FAILED to allocate memory for functions\n"); | |
2297 | return NULL; | |
2298 | } | |
2299 | ||
2300 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) | |
2301 | { | |
2302 | int cnt; | |
2303 | ||
2304 | if (!num_to_init) { | |
2305 | pr_info("ftrace: No functions to be traced?\n"); | |
2306 | return -1; | |
2307 | } | |
2308 | ||
2309 | cnt = num_to_init / ENTRIES_PER_PAGE; | |
2310 | pr_info("ftrace: allocating %ld entries in %d pages\n", | |
2311 | num_to_init, cnt + 1); | |
2312 | ||
3c1720f0 SR |
2313 | return 0; |
2314 | } | |
2315 | ||
5072c59f SR |
2316 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ |
2317 | ||
2318 | struct ftrace_iterator { | |
98c4fd04 | 2319 | loff_t pos; |
4aeb6967 SR |
2320 | loff_t func_pos; |
2321 | struct ftrace_page *pg; | |
2322 | struct dyn_ftrace *func; | |
2323 | struct ftrace_func_probe *probe; | |
2324 | struct trace_parser parser; | |
1cf41dd7 | 2325 | struct ftrace_hash *hash; |
33dc9b12 | 2326 | struct ftrace_ops *ops; |
4aeb6967 SR |
2327 | int hidx; |
2328 | int idx; | |
2329 | unsigned flags; | |
5072c59f SR |
2330 | }; |
2331 | ||
8fc0c701 | 2332 | static void * |
4aeb6967 | 2333 | t_hash_next(struct seq_file *m, loff_t *pos) |
8fc0c701 SR |
2334 | { |
2335 | struct ftrace_iterator *iter = m->private; | |
4aeb6967 | 2336 | struct hlist_node *hnd = NULL; |
8fc0c701 SR |
2337 | struct hlist_head *hhd; |
2338 | ||
8fc0c701 | 2339 | (*pos)++; |
98c4fd04 | 2340 | iter->pos = *pos; |
8fc0c701 | 2341 | |
4aeb6967 SR |
2342 | if (iter->probe) |
2343 | hnd = &iter->probe->node; | |
8fc0c701 SR |
2344 | retry: |
2345 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) | |
2346 | return NULL; | |
2347 | ||
2348 | hhd = &ftrace_func_hash[iter->hidx]; | |
2349 | ||
2350 | if (hlist_empty(hhd)) { | |
2351 | iter->hidx++; | |
2352 | hnd = NULL; | |
2353 | goto retry; | |
2354 | } | |
2355 | ||
2356 | if (!hnd) | |
2357 | hnd = hhd->first; | |
2358 | else { | |
2359 | hnd = hnd->next; | |
2360 | if (!hnd) { | |
2361 | iter->hidx++; | |
2362 | goto retry; | |
2363 | } | |
2364 | } | |
2365 | ||
4aeb6967 SR |
2366 | if (WARN_ON_ONCE(!hnd)) |
2367 | return NULL; | |
2368 | ||
2369 | iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node); | |
2370 | ||
2371 | return iter; | |
8fc0c701 SR |
2372 | } |
2373 | ||
2374 | static void *t_hash_start(struct seq_file *m, loff_t *pos) | |
2375 | { | |
2376 | struct ftrace_iterator *iter = m->private; | |
2377 | void *p = NULL; | |
d82d6244 LZ |
2378 | loff_t l; |
2379 | ||
69a3083c SR |
2380 | if (!(iter->flags & FTRACE_ITER_DO_HASH)) |
2381 | return NULL; | |
2382 | ||
2bccfffd SR |
2383 | if (iter->func_pos > *pos) |
2384 | return NULL; | |
8fc0c701 | 2385 | |
d82d6244 | 2386 | iter->hidx = 0; |
2bccfffd | 2387 | for (l = 0; l <= (*pos - iter->func_pos); ) { |
4aeb6967 | 2388 | p = t_hash_next(m, &l); |
d82d6244 LZ |
2389 | if (!p) |
2390 | break; | |
2391 | } | |
4aeb6967 SR |
2392 | if (!p) |
2393 | return NULL; | |
2394 | ||
98c4fd04 SR |
2395 | /* Only set this if we have an item */ |
2396 | iter->flags |= FTRACE_ITER_HASH; | |
2397 | ||
4aeb6967 | 2398 | return iter; |
8fc0c701 SR |
2399 | } |
2400 | ||
4aeb6967 SR |
2401 | static int |
2402 | t_hash_show(struct seq_file *m, struct ftrace_iterator *iter) | |
8fc0c701 | 2403 | { |
b6887d79 | 2404 | struct ftrace_func_probe *rec; |
8fc0c701 | 2405 | |
4aeb6967 SR |
2406 | rec = iter->probe; |
2407 | if (WARN_ON_ONCE(!rec)) | |
2408 | return -EIO; | |
8fc0c701 | 2409 | |
809dcf29 SR |
2410 | if (rec->ops->print) |
2411 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); | |
2412 | ||
b375a11a | 2413 | seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func); |
8fc0c701 SR |
2414 | |
2415 | if (rec->data) | |
2416 | seq_printf(m, ":%p", rec->data); | |
2417 | seq_putc(m, '\n'); | |
2418 | ||
2419 | return 0; | |
2420 | } | |
2421 | ||
e309b41d | 2422 | static void * |
5072c59f SR |
2423 | t_next(struct seq_file *m, void *v, loff_t *pos) |
2424 | { | |
2425 | struct ftrace_iterator *iter = m->private; | |
fc13cb0c | 2426 | struct ftrace_ops *ops = iter->ops; |
5072c59f SR |
2427 | struct dyn_ftrace *rec = NULL; |
2428 | ||
45a4a237 SR |
2429 | if (unlikely(ftrace_disabled)) |
2430 | return NULL; | |
2431 | ||
8fc0c701 | 2432 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 2433 | return t_hash_next(m, pos); |
8fc0c701 | 2434 | |
5072c59f | 2435 | (*pos)++; |
1106b699 | 2436 | iter->pos = iter->func_pos = *pos; |
5072c59f | 2437 | |
0c75a3ed | 2438 | if (iter->flags & FTRACE_ITER_PRINTALL) |
57c072c7 | 2439 | return t_hash_start(m, pos); |
0c75a3ed | 2440 | |
5072c59f SR |
2441 | retry: |
2442 | if (iter->idx >= iter->pg->index) { | |
2443 | if (iter->pg->next) { | |
2444 | iter->pg = iter->pg->next; | |
2445 | iter->idx = 0; | |
2446 | goto retry; | |
2447 | } | |
2448 | } else { | |
2449 | rec = &iter->pg->records[iter->idx++]; | |
32082309 | 2450 | if (((iter->flags & FTRACE_ITER_FILTER) && |
f45948e8 | 2451 | !(ftrace_lookup_ip(ops->filter_hash, rec->ip))) || |
0183fb1c | 2452 | |
41c52c0d | 2453 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
647bcd03 SR |
2454 | !ftrace_lookup_ip(ops->notrace_hash, rec->ip)) || |
2455 | ||
2456 | ((iter->flags & FTRACE_ITER_ENABLED) && | |
2457 | !(rec->flags & ~FTRACE_FL_MASK))) { | |
2458 | ||
5072c59f SR |
2459 | rec = NULL; |
2460 | goto retry; | |
2461 | } | |
2462 | } | |
2463 | ||
4aeb6967 | 2464 | if (!rec) |
57c072c7 | 2465 | return t_hash_start(m, pos); |
4aeb6967 SR |
2466 | |
2467 | iter->func = rec; | |
2468 | ||
2469 | return iter; | |
5072c59f SR |
2470 | } |
2471 | ||
98c4fd04 SR |
2472 | static void reset_iter_read(struct ftrace_iterator *iter) |
2473 | { | |
2474 | iter->pos = 0; | |
2475 | iter->func_pos = 0; | |
70f77b3f | 2476 | iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_HASH); |
5072c59f SR |
2477 | } |
2478 | ||
2479 | static void *t_start(struct seq_file *m, loff_t *pos) | |
2480 | { | |
2481 | struct ftrace_iterator *iter = m->private; | |
fc13cb0c | 2482 | struct ftrace_ops *ops = iter->ops; |
5072c59f | 2483 | void *p = NULL; |
694ce0a5 | 2484 | loff_t l; |
5072c59f | 2485 | |
8fc0c701 | 2486 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
2487 | |
2488 | if (unlikely(ftrace_disabled)) | |
2489 | return NULL; | |
2490 | ||
98c4fd04 SR |
2491 | /* |
2492 | * If an lseek was done, then reset and start from beginning. | |
2493 | */ | |
2494 | if (*pos < iter->pos) | |
2495 | reset_iter_read(iter); | |
2496 | ||
0c75a3ed SR |
2497 | /* |
2498 | * For set_ftrace_filter reading, if we have the filter | |
2499 | * off, we can short cut and just print out that all | |
2500 | * functions are enabled. | |
2501 | */ | |
06a51d93 SR |
2502 | if (iter->flags & FTRACE_ITER_FILTER && |
2503 | ftrace_hash_empty(ops->filter_hash)) { | |
0c75a3ed | 2504 | if (*pos > 0) |
8fc0c701 | 2505 | return t_hash_start(m, pos); |
0c75a3ed | 2506 | iter->flags |= FTRACE_ITER_PRINTALL; |
df091625 CW |
2507 | /* reset in case of seek/pread */ |
2508 | iter->flags &= ~FTRACE_ITER_HASH; | |
0c75a3ed SR |
2509 | return iter; |
2510 | } | |
2511 | ||
8fc0c701 SR |
2512 | if (iter->flags & FTRACE_ITER_HASH) |
2513 | return t_hash_start(m, pos); | |
2514 | ||
98c4fd04 SR |
2515 | /* |
2516 | * Unfortunately, we need to restart at ftrace_pages_start | |
2517 | * every time we let go of the ftrace_mutex. This is because | |
2518 | * those pointers can change without the lock. | |
2519 | */ | |
694ce0a5 LZ |
2520 | iter->pg = ftrace_pages_start; |
2521 | iter->idx = 0; | |
2522 | for (l = 0; l <= *pos; ) { | |
2523 | p = t_next(m, p, &l); | |
2524 | if (!p) | |
2525 | break; | |
50cdaf08 | 2526 | } |
5821e1b7 | 2527 | |
69a3083c SR |
2528 | if (!p) |
2529 | return t_hash_start(m, pos); | |
4aeb6967 SR |
2530 | |
2531 | return iter; | |
5072c59f SR |
2532 | } |
2533 | ||
2534 | static void t_stop(struct seq_file *m, void *p) | |
2535 | { | |
8fc0c701 | 2536 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
2537 | } |
2538 | ||
2539 | static int t_show(struct seq_file *m, void *v) | |
2540 | { | |
0c75a3ed | 2541 | struct ftrace_iterator *iter = m->private; |
4aeb6967 | 2542 | struct dyn_ftrace *rec; |
5072c59f | 2543 | |
8fc0c701 | 2544 | if (iter->flags & FTRACE_ITER_HASH) |
4aeb6967 | 2545 | return t_hash_show(m, iter); |
8fc0c701 | 2546 | |
0c75a3ed SR |
2547 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
2548 | seq_printf(m, "#### all functions enabled ####\n"); | |
2549 | return 0; | |
2550 | } | |
2551 | ||
4aeb6967 SR |
2552 | rec = iter->func; |
2553 | ||
5072c59f SR |
2554 | if (!rec) |
2555 | return 0; | |
2556 | ||
647bcd03 SR |
2557 | seq_printf(m, "%ps", (void *)rec->ip); |
2558 | if (iter->flags & FTRACE_ITER_ENABLED) | |
08f6fba5 SR |
2559 | seq_printf(m, " (%ld)%s", |
2560 | rec->flags & ~FTRACE_FL_MASK, | |
2561 | rec->flags & FTRACE_FL_REGS ? " R" : ""); | |
647bcd03 | 2562 | seq_printf(m, "\n"); |
5072c59f SR |
2563 | |
2564 | return 0; | |
2565 | } | |
2566 | ||
88e9d34c | 2567 | static const struct seq_operations show_ftrace_seq_ops = { |
5072c59f SR |
2568 | .start = t_start, |
2569 | .next = t_next, | |
2570 | .stop = t_stop, | |
2571 | .show = t_show, | |
2572 | }; | |
2573 | ||
e309b41d | 2574 | static int |
5072c59f SR |
2575 | ftrace_avail_open(struct inode *inode, struct file *file) |
2576 | { | |
2577 | struct ftrace_iterator *iter; | |
5072c59f | 2578 | |
4eebcc81 SR |
2579 | if (unlikely(ftrace_disabled)) |
2580 | return -ENODEV; | |
2581 | ||
50e18b94 JO |
2582 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
2583 | if (iter) { | |
2584 | iter->pg = ftrace_pages_start; | |
2585 | iter->ops = &global_ops; | |
4bf39a94 | 2586 | } |
5072c59f | 2587 | |
50e18b94 | 2588 | return iter ? 0 : -ENOMEM; |
5072c59f SR |
2589 | } |
2590 | ||
647bcd03 SR |
2591 | static int |
2592 | ftrace_enabled_open(struct inode *inode, struct file *file) | |
2593 | { | |
2594 | struct ftrace_iterator *iter; | |
647bcd03 SR |
2595 | |
2596 | if (unlikely(ftrace_disabled)) | |
2597 | return -ENODEV; | |
2598 | ||
50e18b94 JO |
2599 | iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter)); |
2600 | if (iter) { | |
2601 | iter->pg = ftrace_pages_start; | |
2602 | iter->flags = FTRACE_ITER_ENABLED; | |
2603 | iter->ops = &global_ops; | |
647bcd03 SR |
2604 | } |
2605 | ||
50e18b94 | 2606 | return iter ? 0 : -ENOMEM; |
647bcd03 SR |
2607 | } |
2608 | ||
1cf41dd7 | 2609 | static void ftrace_filter_reset(struct ftrace_hash *hash) |
5072c59f | 2610 | { |
52baf119 | 2611 | mutex_lock(&ftrace_lock); |
1cf41dd7 | 2612 | ftrace_hash_clear(hash); |
52baf119 | 2613 | mutex_unlock(&ftrace_lock); |
5072c59f SR |
2614 | } |
2615 | ||
fc13cb0c SR |
2616 | /** |
2617 | * ftrace_regex_open - initialize function tracer filter files | |
2618 | * @ops: The ftrace_ops that hold the hash filters | |
2619 | * @flag: The type of filter to process | |
2620 | * @inode: The inode, usually passed in to your open routine | |
2621 | * @file: The file, usually passed in to your open routine | |
2622 | * | |
2623 | * ftrace_regex_open() initializes the filter files for the | |
2624 | * @ops. Depending on @flag it may process the filter hash or | |
2625 | * the notrace hash of @ops. With this called from the open | |
2626 | * routine, you can use ftrace_filter_write() for the write | |
2627 | * routine if @flag has FTRACE_ITER_FILTER set, or | |
2628 | * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set. | |
2629 | * ftrace_regex_lseek() should be used as the lseek routine, and | |
2630 | * release must call ftrace_regex_release(). | |
2631 | */ | |
2632 | int | |
f45948e8 | 2633 | ftrace_regex_open(struct ftrace_ops *ops, int flag, |
1cf41dd7 | 2634 | struct inode *inode, struct file *file) |
5072c59f SR |
2635 | { |
2636 | struct ftrace_iterator *iter; | |
f45948e8 | 2637 | struct ftrace_hash *hash; |
5072c59f SR |
2638 | int ret = 0; |
2639 | ||
4eebcc81 SR |
2640 | if (unlikely(ftrace_disabled)) |
2641 | return -ENODEV; | |
2642 | ||
5072c59f SR |
2643 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
2644 | if (!iter) | |
2645 | return -ENOMEM; | |
2646 | ||
689fd8b6 | 2647 | if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) { |
2648 | kfree(iter); | |
2649 | return -ENOMEM; | |
2650 | } | |
2651 | ||
f45948e8 SR |
2652 | if (flag & FTRACE_ITER_NOTRACE) |
2653 | hash = ops->notrace_hash; | |
2654 | else | |
2655 | hash = ops->filter_hash; | |
2656 | ||
33dc9b12 SR |
2657 | iter->ops = ops; |
2658 | iter->flags = flag; | |
2659 | ||
2660 | if (file->f_mode & FMODE_WRITE) { | |
2661 | mutex_lock(&ftrace_lock); | |
2662 | iter->hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash); | |
2663 | mutex_unlock(&ftrace_lock); | |
2664 | ||
2665 | if (!iter->hash) { | |
2666 | trace_parser_put(&iter->parser); | |
2667 | kfree(iter); | |
2668 | return -ENOMEM; | |
2669 | } | |
2670 | } | |
1cf41dd7 | 2671 | |
41c52c0d | 2672 | mutex_lock(&ftrace_regex_lock); |
33dc9b12 | 2673 | |
5072c59f | 2674 | if ((file->f_mode & FMODE_WRITE) && |
8650ae32 | 2675 | (file->f_flags & O_TRUNC)) |
33dc9b12 | 2676 | ftrace_filter_reset(iter->hash); |
5072c59f SR |
2677 | |
2678 | if (file->f_mode & FMODE_READ) { | |
2679 | iter->pg = ftrace_pages_start; | |
5072c59f SR |
2680 | |
2681 | ret = seq_open(file, &show_ftrace_seq_ops); | |
2682 | if (!ret) { | |
2683 | struct seq_file *m = file->private_data; | |
2684 | m->private = iter; | |
79fe249c | 2685 | } else { |
33dc9b12 SR |
2686 | /* Failed */ |
2687 | free_ftrace_hash(iter->hash); | |
79fe249c | 2688 | trace_parser_put(&iter->parser); |
5072c59f | 2689 | kfree(iter); |
79fe249c | 2690 | } |
5072c59f SR |
2691 | } else |
2692 | file->private_data = iter; | |
41c52c0d | 2693 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
2694 | |
2695 | return ret; | |
2696 | } | |
2697 | ||
41c52c0d SR |
2698 | static int |
2699 | ftrace_filter_open(struct inode *inode, struct file *file) | |
2700 | { | |
69a3083c SR |
2701 | return ftrace_regex_open(&global_ops, |
2702 | FTRACE_ITER_FILTER | FTRACE_ITER_DO_HASH, | |
2703 | inode, file); | |
41c52c0d SR |
2704 | } |
2705 | ||
2706 | static int | |
2707 | ftrace_notrace_open(struct inode *inode, struct file *file) | |
2708 | { | |
f45948e8 | 2709 | return ftrace_regex_open(&global_ops, FTRACE_ITER_NOTRACE, |
1cf41dd7 | 2710 | inode, file); |
41c52c0d SR |
2711 | } |
2712 | ||
fc13cb0c | 2713 | loff_t |
965c8e59 | 2714 | ftrace_regex_lseek(struct file *file, loff_t offset, int whence) |
5072c59f SR |
2715 | { |
2716 | loff_t ret; | |
2717 | ||
2718 | if (file->f_mode & FMODE_READ) | |
965c8e59 | 2719 | ret = seq_lseek(file, offset, whence); |
5072c59f SR |
2720 | else |
2721 | file->f_pos = ret = 1; | |
2722 | ||
2723 | return ret; | |
2724 | } | |
2725 | ||
64e7c440 | 2726 | static int ftrace_match(char *str, char *regex, int len, int type) |
9f4801e3 | 2727 | { |
9f4801e3 | 2728 | int matched = 0; |
751e9983 | 2729 | int slen; |
9f4801e3 | 2730 | |
9f4801e3 SR |
2731 | switch (type) { |
2732 | case MATCH_FULL: | |
2733 | if (strcmp(str, regex) == 0) | |
2734 | matched = 1; | |
2735 | break; | |
2736 | case MATCH_FRONT_ONLY: | |
2737 | if (strncmp(str, regex, len) == 0) | |
2738 | matched = 1; | |
2739 | break; | |
2740 | case MATCH_MIDDLE_ONLY: | |
2741 | if (strstr(str, regex)) | |
2742 | matched = 1; | |
2743 | break; | |
2744 | case MATCH_END_ONLY: | |
751e9983 LZ |
2745 | slen = strlen(str); |
2746 | if (slen >= len && memcmp(str + slen - len, regex, len) == 0) | |
9f4801e3 SR |
2747 | matched = 1; |
2748 | break; | |
2749 | } | |
2750 | ||
2751 | return matched; | |
2752 | } | |
2753 | ||
b448c4e3 | 2754 | static int |
1cf41dd7 | 2755 | enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not) |
996e87be | 2756 | { |
b448c4e3 | 2757 | struct ftrace_func_entry *entry; |
b448c4e3 SR |
2758 | int ret = 0; |
2759 | ||
1cf41dd7 SR |
2760 | entry = ftrace_lookup_ip(hash, rec->ip); |
2761 | if (not) { | |
2762 | /* Do nothing if it doesn't exist */ | |
2763 | if (!entry) | |
2764 | return 0; | |
b448c4e3 | 2765 | |
33dc9b12 | 2766 | free_hash_entry(hash, entry); |
1cf41dd7 SR |
2767 | } else { |
2768 | /* Do nothing if it exists */ | |
2769 | if (entry) | |
2770 | return 0; | |
b448c4e3 | 2771 | |
1cf41dd7 | 2772 | ret = add_hash_entry(hash, rec->ip); |
b448c4e3 SR |
2773 | } |
2774 | return ret; | |
996e87be SR |
2775 | } |
2776 | ||
64e7c440 | 2777 | static int |
b9df92d2 SR |
2778 | ftrace_match_record(struct dyn_ftrace *rec, char *mod, |
2779 | char *regex, int len, int type) | |
64e7c440 SR |
2780 | { |
2781 | char str[KSYM_SYMBOL_LEN]; | |
b9df92d2 SR |
2782 | char *modname; |
2783 | ||
2784 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); | |
2785 | ||
2786 | if (mod) { | |
2787 | /* module lookup requires matching the module */ | |
2788 | if (!modname || strcmp(modname, mod)) | |
2789 | return 0; | |
2790 | ||
2791 | /* blank search means to match all funcs in the mod */ | |
2792 | if (!len) | |
2793 | return 1; | |
2794 | } | |
64e7c440 | 2795 | |
64e7c440 SR |
2796 | return ftrace_match(str, regex, len, type); |
2797 | } | |
2798 | ||
1cf41dd7 SR |
2799 | static int |
2800 | match_records(struct ftrace_hash *hash, char *buff, | |
2801 | int len, char *mod, int not) | |
9f4801e3 | 2802 | { |
b9df92d2 | 2803 | unsigned search_len = 0; |
9f4801e3 SR |
2804 | struct ftrace_page *pg; |
2805 | struct dyn_ftrace *rec; | |
b9df92d2 SR |
2806 | int type = MATCH_FULL; |
2807 | char *search = buff; | |
311d16da | 2808 | int found = 0; |
b448c4e3 | 2809 | int ret; |
9f4801e3 | 2810 | |
b9df92d2 SR |
2811 | if (len) { |
2812 | type = filter_parse_regex(buff, len, &search, ¬); | |
2813 | search_len = strlen(search); | |
2814 | } | |
9f4801e3 | 2815 | |
52baf119 | 2816 | mutex_lock(&ftrace_lock); |
265c831c | 2817 | |
b9df92d2 SR |
2818 | if (unlikely(ftrace_disabled)) |
2819 | goto out_unlock; | |
9f4801e3 | 2820 | |
265c831c | 2821 | do_for_each_ftrace_rec(pg, rec) { |
b9df92d2 | 2822 | if (ftrace_match_record(rec, mod, search, search_len, type)) { |
1cf41dd7 | 2823 | ret = enter_record(hash, rec, not); |
b448c4e3 SR |
2824 | if (ret < 0) { |
2825 | found = ret; | |
2826 | goto out_unlock; | |
2827 | } | |
311d16da | 2828 | found = 1; |
265c831c SR |
2829 | } |
2830 | } while_for_each_ftrace_rec(); | |
b9df92d2 | 2831 | out_unlock: |
52baf119 | 2832 | mutex_unlock(&ftrace_lock); |
311d16da LZ |
2833 | |
2834 | return found; | |
5072c59f SR |
2835 | } |
2836 | ||
64e7c440 | 2837 | static int |
1cf41dd7 | 2838 | ftrace_match_records(struct ftrace_hash *hash, char *buff, int len) |
64e7c440 | 2839 | { |
1cf41dd7 | 2840 | return match_records(hash, buff, len, NULL, 0); |
64e7c440 SR |
2841 | } |
2842 | ||
1cf41dd7 SR |
2843 | static int |
2844 | ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod) | |
64e7c440 | 2845 | { |
64e7c440 | 2846 | int not = 0; |
6a24a244 | 2847 | |
64e7c440 SR |
2848 | /* blank or '*' mean the same */ |
2849 | if (strcmp(buff, "*") == 0) | |
2850 | buff[0] = 0; | |
2851 | ||
2852 | /* handle the case of 'dont filter this module' */ | |
2853 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { | |
2854 | buff[0] = 0; | |
2855 | not = 1; | |
2856 | } | |
2857 | ||
1cf41dd7 | 2858 | return match_records(hash, buff, strlen(buff), mod, not); |
64e7c440 SR |
2859 | } |
2860 | ||
f6180773 SR |
2861 | /* |
2862 | * We register the module command as a template to show others how | |
2863 | * to register the a command as well. | |
2864 | */ | |
2865 | ||
2866 | static int | |
43dd61c9 SR |
2867 | ftrace_mod_callback(struct ftrace_hash *hash, |
2868 | char *func, char *cmd, char *param, int enable) | |
f6180773 SR |
2869 | { |
2870 | char *mod; | |
b448c4e3 | 2871 | int ret = -EINVAL; |
f6180773 SR |
2872 | |
2873 | /* | |
2874 | * cmd == 'mod' because we only registered this func | |
2875 | * for the 'mod' ftrace_func_command. | |
2876 | * But if you register one func with multiple commands, | |
2877 | * you can tell which command was used by the cmd | |
2878 | * parameter. | |
2879 | */ | |
2880 | ||
2881 | /* we must have a module name */ | |
2882 | if (!param) | |
b448c4e3 | 2883 | return ret; |
f6180773 SR |
2884 | |
2885 | mod = strsep(¶m, ":"); | |
2886 | if (!strlen(mod)) | |
b448c4e3 | 2887 | return ret; |
f6180773 | 2888 | |
1cf41dd7 | 2889 | ret = ftrace_match_module_records(hash, func, mod); |
b448c4e3 SR |
2890 | if (!ret) |
2891 | ret = -EINVAL; | |
2892 | if (ret < 0) | |
2893 | return ret; | |
2894 | ||
2895 | return 0; | |
f6180773 SR |
2896 | } |
2897 | ||
2898 | static struct ftrace_func_command ftrace_mod_cmd = { | |
2899 | .name = "mod", | |
2900 | .func = ftrace_mod_callback, | |
2901 | }; | |
2902 | ||
2903 | static int __init ftrace_mod_cmd_init(void) | |
2904 | { | |
2905 | return register_ftrace_command(&ftrace_mod_cmd); | |
2906 | } | |
6f415672 | 2907 | core_initcall(ftrace_mod_cmd_init); |
f6180773 | 2908 | |
2f5f6ad9 | 2909 | static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 2910 | struct ftrace_ops *op, struct pt_regs *pt_regs) |
59df055f | 2911 | { |
b6887d79 | 2912 | struct ftrace_func_probe *entry; |
59df055f SR |
2913 | struct hlist_head *hhd; |
2914 | struct hlist_node *n; | |
2915 | unsigned long key; | |
59df055f SR |
2916 | |
2917 | key = hash_long(ip, FTRACE_HASH_BITS); | |
2918 | ||
2919 | hhd = &ftrace_func_hash[key]; | |
2920 | ||
2921 | if (hlist_empty(hhd)) | |
2922 | return; | |
2923 | ||
2924 | /* | |
2925 | * Disable preemption for these calls to prevent a RCU grace | |
2926 | * period. This syncs the hash iteration and freeing of items | |
2927 | * on the hash. rcu_read_lock is too dangerous here. | |
2928 | */ | |
5168ae50 | 2929 | preempt_disable_notrace(); |
59df055f SR |
2930 | hlist_for_each_entry_rcu(entry, n, hhd, node) { |
2931 | if (entry->ip == ip) | |
2932 | entry->ops->func(ip, parent_ip, &entry->data); | |
2933 | } | |
5168ae50 | 2934 | preempt_enable_notrace(); |
59df055f SR |
2935 | } |
2936 | ||
b6887d79 | 2937 | static struct ftrace_ops trace_probe_ops __read_mostly = |
59df055f | 2938 | { |
fb9fb015 | 2939 | .func = function_trace_probe_call, |
59df055f SR |
2940 | }; |
2941 | ||
b6887d79 | 2942 | static int ftrace_probe_registered; |
59df055f | 2943 | |
b6887d79 | 2944 | static void __enable_ftrace_function_probe(void) |
59df055f | 2945 | { |
b848914c | 2946 | int ret; |
59df055f SR |
2947 | int i; |
2948 | ||
b6887d79 | 2949 | if (ftrace_probe_registered) |
59df055f SR |
2950 | return; |
2951 | ||
2952 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2953 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2954 | if (hhd->first) | |
2955 | break; | |
2956 | } | |
2957 | /* Nothing registered? */ | |
2958 | if (i == FTRACE_FUNC_HASHSIZE) | |
2959 | return; | |
2960 | ||
b848914c SR |
2961 | ret = __register_ftrace_function(&trace_probe_ops); |
2962 | if (!ret) | |
a1cd6173 | 2963 | ret = ftrace_startup(&trace_probe_ops, 0); |
b848914c | 2964 | |
b6887d79 | 2965 | ftrace_probe_registered = 1; |
59df055f SR |
2966 | } |
2967 | ||
b6887d79 | 2968 | static void __disable_ftrace_function_probe(void) |
59df055f | 2969 | { |
b848914c | 2970 | int ret; |
59df055f SR |
2971 | int i; |
2972 | ||
b6887d79 | 2973 | if (!ftrace_probe_registered) |
59df055f SR |
2974 | return; |
2975 | ||
2976 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
2977 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
2978 | if (hhd->first) | |
2979 | return; | |
2980 | } | |
2981 | ||
2982 | /* no more funcs left */ | |
b848914c SR |
2983 | ret = __unregister_ftrace_function(&trace_probe_ops); |
2984 | if (!ret) | |
2985 | ftrace_shutdown(&trace_probe_ops, 0); | |
2986 | ||
b6887d79 | 2987 | ftrace_probe_registered = 0; |
59df055f SR |
2988 | } |
2989 | ||
2990 | ||
2991 | static void ftrace_free_entry_rcu(struct rcu_head *rhp) | |
2992 | { | |
b6887d79 SR |
2993 | struct ftrace_func_probe *entry = |
2994 | container_of(rhp, struct ftrace_func_probe, rcu); | |
59df055f SR |
2995 | |
2996 | if (entry->ops->free) | |
2997 | entry->ops->free(&entry->data); | |
2998 | kfree(entry); | |
2999 | } | |
3000 | ||
3001 | ||
3002 | int | |
b6887d79 | 3003 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3004 | void *data) |
3005 | { | |
b6887d79 | 3006 | struct ftrace_func_probe *entry; |
59df055f SR |
3007 | struct ftrace_page *pg; |
3008 | struct dyn_ftrace *rec; | |
59df055f | 3009 | int type, len, not; |
6a24a244 | 3010 | unsigned long key; |
59df055f SR |
3011 | int count = 0; |
3012 | char *search; | |
3013 | ||
3f6fe06d | 3014 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
3015 | len = strlen(search); |
3016 | ||
b6887d79 | 3017 | /* we do not support '!' for function probes */ |
59df055f SR |
3018 | if (WARN_ON(not)) |
3019 | return -EINVAL; | |
3020 | ||
3021 | mutex_lock(&ftrace_lock); | |
59df055f | 3022 | |
45a4a237 SR |
3023 | if (unlikely(ftrace_disabled)) |
3024 | goto out_unlock; | |
59df055f | 3025 | |
45a4a237 | 3026 | do_for_each_ftrace_rec(pg, rec) { |
59df055f | 3027 | |
b9df92d2 | 3028 | if (!ftrace_match_record(rec, NULL, search, len, type)) |
59df055f SR |
3029 | continue; |
3030 | ||
3031 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); | |
3032 | if (!entry) { | |
b6887d79 | 3033 | /* If we did not process any, then return error */ |
59df055f SR |
3034 | if (!count) |
3035 | count = -ENOMEM; | |
3036 | goto out_unlock; | |
3037 | } | |
3038 | ||
3039 | count++; | |
3040 | ||
3041 | entry->data = data; | |
3042 | ||
3043 | /* | |
3044 | * The caller might want to do something special | |
3045 | * for each function we find. We call the callback | |
3046 | * to give the caller an opportunity to do so. | |
3047 | */ | |
3048 | if (ops->callback) { | |
3049 | if (ops->callback(rec->ip, &entry->data) < 0) { | |
3050 | /* caller does not like this func */ | |
3051 | kfree(entry); | |
3052 | continue; | |
3053 | } | |
3054 | } | |
3055 | ||
3056 | entry->ops = ops; | |
3057 | entry->ip = rec->ip; | |
3058 | ||
3059 | key = hash_long(entry->ip, FTRACE_HASH_BITS); | |
3060 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); | |
3061 | ||
3062 | } while_for_each_ftrace_rec(); | |
b6887d79 | 3063 | __enable_ftrace_function_probe(); |
59df055f SR |
3064 | |
3065 | out_unlock: | |
3066 | mutex_unlock(&ftrace_lock); | |
3067 | ||
3068 | return count; | |
3069 | } | |
3070 | ||
3071 | enum { | |
b6887d79 SR |
3072 | PROBE_TEST_FUNC = 1, |
3073 | PROBE_TEST_DATA = 2 | |
59df055f SR |
3074 | }; |
3075 | ||
3076 | static void | |
b6887d79 | 3077 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3078 | void *data, int flags) |
3079 | { | |
b6887d79 | 3080 | struct ftrace_func_probe *entry; |
59df055f SR |
3081 | struct hlist_node *n, *tmp; |
3082 | char str[KSYM_SYMBOL_LEN]; | |
3083 | int type = MATCH_FULL; | |
3084 | int i, len = 0; | |
3085 | char *search; | |
3086 | ||
b36461da | 3087 | if (glob && (strcmp(glob, "*") == 0 || !strlen(glob))) |
59df055f | 3088 | glob = NULL; |
b36461da | 3089 | else if (glob) { |
59df055f SR |
3090 | int not; |
3091 | ||
3f6fe06d | 3092 | type = filter_parse_regex(glob, strlen(glob), &search, ¬); |
59df055f SR |
3093 | len = strlen(search); |
3094 | ||
b6887d79 | 3095 | /* we do not support '!' for function probes */ |
59df055f SR |
3096 | if (WARN_ON(not)) |
3097 | return; | |
3098 | } | |
3099 | ||
3100 | mutex_lock(&ftrace_lock); | |
3101 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { | |
3102 | struct hlist_head *hhd = &ftrace_func_hash[i]; | |
3103 | ||
3104 | hlist_for_each_entry_safe(entry, n, tmp, hhd, node) { | |
3105 | ||
3106 | /* break up if statements for readability */ | |
b6887d79 | 3107 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
59df055f SR |
3108 | continue; |
3109 | ||
b6887d79 | 3110 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
59df055f SR |
3111 | continue; |
3112 | ||
3113 | /* do this last, since it is the most expensive */ | |
3114 | if (glob) { | |
3115 | kallsyms_lookup(entry->ip, NULL, NULL, | |
3116 | NULL, str); | |
3117 | if (!ftrace_match(str, glob, len, type)) | |
3118 | continue; | |
3119 | } | |
3120 | ||
3121 | hlist_del(&entry->node); | |
3122 | call_rcu(&entry->rcu, ftrace_free_entry_rcu); | |
3123 | } | |
3124 | } | |
b6887d79 | 3125 | __disable_ftrace_function_probe(); |
59df055f SR |
3126 | mutex_unlock(&ftrace_lock); |
3127 | } | |
3128 | ||
3129 | void | |
b6887d79 | 3130 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
59df055f SR |
3131 | void *data) |
3132 | { | |
b6887d79 SR |
3133 | __unregister_ftrace_function_probe(glob, ops, data, |
3134 | PROBE_TEST_FUNC | PROBE_TEST_DATA); | |
59df055f SR |
3135 | } |
3136 | ||
3137 | void | |
b6887d79 | 3138 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
59df055f | 3139 | { |
b6887d79 | 3140 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
59df055f SR |
3141 | } |
3142 | ||
b6887d79 | 3143 | void unregister_ftrace_function_probe_all(char *glob) |
59df055f | 3144 | { |
b6887d79 | 3145 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
59df055f SR |
3146 | } |
3147 | ||
f6180773 SR |
3148 | static LIST_HEAD(ftrace_commands); |
3149 | static DEFINE_MUTEX(ftrace_cmd_mutex); | |
3150 | ||
3151 | int register_ftrace_command(struct ftrace_func_command *cmd) | |
3152 | { | |
3153 | struct ftrace_func_command *p; | |
3154 | int ret = 0; | |
3155 | ||
3156 | mutex_lock(&ftrace_cmd_mutex); | |
3157 | list_for_each_entry(p, &ftrace_commands, list) { | |
3158 | if (strcmp(cmd->name, p->name) == 0) { | |
3159 | ret = -EBUSY; | |
3160 | goto out_unlock; | |
3161 | } | |
3162 | } | |
3163 | list_add(&cmd->list, &ftrace_commands); | |
3164 | out_unlock: | |
3165 | mutex_unlock(&ftrace_cmd_mutex); | |
3166 | ||
3167 | return ret; | |
3168 | } | |
3169 | ||
3170 | int unregister_ftrace_command(struct ftrace_func_command *cmd) | |
3171 | { | |
3172 | struct ftrace_func_command *p, *n; | |
3173 | int ret = -ENODEV; | |
3174 | ||
3175 | mutex_lock(&ftrace_cmd_mutex); | |
3176 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { | |
3177 | if (strcmp(cmd->name, p->name) == 0) { | |
3178 | ret = 0; | |
3179 | list_del_init(&p->list); | |
3180 | goto out_unlock; | |
3181 | } | |
3182 | } | |
3183 | out_unlock: | |
3184 | mutex_unlock(&ftrace_cmd_mutex); | |
3185 | ||
3186 | return ret; | |
3187 | } | |
3188 | ||
33dc9b12 SR |
3189 | static int ftrace_process_regex(struct ftrace_hash *hash, |
3190 | char *buff, int len, int enable) | |
64e7c440 | 3191 | { |
f6180773 | 3192 | char *func, *command, *next = buff; |
6a24a244 | 3193 | struct ftrace_func_command *p; |
0aff1c0c | 3194 | int ret = -EINVAL; |
64e7c440 SR |
3195 | |
3196 | func = strsep(&next, ":"); | |
3197 | ||
3198 | if (!next) { | |
1cf41dd7 | 3199 | ret = ftrace_match_records(hash, func, len); |
b448c4e3 SR |
3200 | if (!ret) |
3201 | ret = -EINVAL; | |
3202 | if (ret < 0) | |
3203 | return ret; | |
3204 | return 0; | |
64e7c440 SR |
3205 | } |
3206 | ||
f6180773 | 3207 | /* command found */ |
64e7c440 SR |
3208 | |
3209 | command = strsep(&next, ":"); | |
3210 | ||
f6180773 SR |
3211 | mutex_lock(&ftrace_cmd_mutex); |
3212 | list_for_each_entry(p, &ftrace_commands, list) { | |
3213 | if (strcmp(p->name, command) == 0) { | |
43dd61c9 | 3214 | ret = p->func(hash, func, command, next, enable); |
f6180773 SR |
3215 | goto out_unlock; |
3216 | } | |
64e7c440 | 3217 | } |
f6180773 SR |
3218 | out_unlock: |
3219 | mutex_unlock(&ftrace_cmd_mutex); | |
64e7c440 | 3220 | |
f6180773 | 3221 | return ret; |
64e7c440 SR |
3222 | } |
3223 | ||
e309b41d | 3224 | static ssize_t |
41c52c0d SR |
3225 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
3226 | size_t cnt, loff_t *ppos, int enable) | |
5072c59f SR |
3227 | { |
3228 | struct ftrace_iterator *iter; | |
689fd8b6 | 3229 | struct trace_parser *parser; |
3230 | ssize_t ret, read; | |
5072c59f | 3231 | |
4ba7978e | 3232 | if (!cnt) |
5072c59f SR |
3233 | return 0; |
3234 | ||
41c52c0d | 3235 | mutex_lock(&ftrace_regex_lock); |
5072c59f | 3236 | |
45a4a237 SR |
3237 | ret = -ENODEV; |
3238 | if (unlikely(ftrace_disabled)) | |
3239 | goto out_unlock; | |
3240 | ||
5072c59f SR |
3241 | if (file->f_mode & FMODE_READ) { |
3242 | struct seq_file *m = file->private_data; | |
3243 | iter = m->private; | |
3244 | } else | |
3245 | iter = file->private_data; | |
3246 | ||
689fd8b6 | 3247 | parser = &iter->parser; |
3248 | read = trace_get_user(parser, ubuf, cnt, ppos); | |
5072c59f | 3249 | |
4ba7978e | 3250 | if (read >= 0 && trace_parser_loaded(parser) && |
689fd8b6 | 3251 | !trace_parser_cont(parser)) { |
33dc9b12 | 3252 | ret = ftrace_process_regex(iter->hash, parser->buffer, |
689fd8b6 | 3253 | parser->idx, enable); |
313254a9 | 3254 | trace_parser_clear(parser); |
5072c59f | 3255 | if (ret) |
ed146b25 | 3256 | goto out_unlock; |
eda1e328 | 3257 | } |
5072c59f | 3258 | |
5072c59f | 3259 | ret = read; |
ed146b25 | 3260 | out_unlock: |
689fd8b6 | 3261 | mutex_unlock(&ftrace_regex_lock); |
ed146b25 | 3262 | |
5072c59f SR |
3263 | return ret; |
3264 | } | |
3265 | ||
fc13cb0c | 3266 | ssize_t |
41c52c0d SR |
3267 | ftrace_filter_write(struct file *file, const char __user *ubuf, |
3268 | size_t cnt, loff_t *ppos) | |
3269 | { | |
3270 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); | |
3271 | } | |
3272 | ||
fc13cb0c | 3273 | ssize_t |
41c52c0d SR |
3274 | ftrace_notrace_write(struct file *file, const char __user *ubuf, |
3275 | size_t cnt, loff_t *ppos) | |
3276 | { | |
3277 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); | |
3278 | } | |
3279 | ||
33dc9b12 | 3280 | static int |
647664ea MH |
3281 | ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) |
3282 | { | |
3283 | struct ftrace_func_entry *entry; | |
3284 | ||
3285 | if (!ftrace_location(ip)) | |
3286 | return -EINVAL; | |
3287 | ||
3288 | if (remove) { | |
3289 | entry = ftrace_lookup_ip(hash, ip); | |
3290 | if (!entry) | |
3291 | return -ENOENT; | |
3292 | free_hash_entry(hash, entry); | |
3293 | return 0; | |
3294 | } | |
3295 | ||
3296 | return add_hash_entry(hash, ip); | |
3297 | } | |
3298 | ||
3299 | static int | |
3300 | ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, | |
3301 | unsigned long ip, int remove, int reset, int enable) | |
41c52c0d | 3302 | { |
33dc9b12 | 3303 | struct ftrace_hash **orig_hash; |
f45948e8 | 3304 | struct ftrace_hash *hash; |
33dc9b12 | 3305 | int ret; |
f45948e8 | 3306 | |
936e074b SR |
3307 | /* All global ops uses the global ops filters */ |
3308 | if (ops->flags & FTRACE_OPS_FL_GLOBAL) | |
3309 | ops = &global_ops; | |
3310 | ||
41c52c0d | 3311 | if (unlikely(ftrace_disabled)) |
33dc9b12 | 3312 | return -ENODEV; |
41c52c0d | 3313 | |
f45948e8 | 3314 | if (enable) |
33dc9b12 | 3315 | orig_hash = &ops->filter_hash; |
f45948e8 | 3316 | else |
33dc9b12 SR |
3317 | orig_hash = &ops->notrace_hash; |
3318 | ||
3319 | hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); | |
3320 | if (!hash) | |
3321 | return -ENOMEM; | |
f45948e8 | 3322 | |
41c52c0d SR |
3323 | mutex_lock(&ftrace_regex_lock); |
3324 | if (reset) | |
1cf41dd7 | 3325 | ftrace_filter_reset(hash); |
ac483c44 JO |
3326 | if (buf && !ftrace_match_records(hash, buf, len)) { |
3327 | ret = -EINVAL; | |
3328 | goto out_regex_unlock; | |
3329 | } | |
647664ea MH |
3330 | if (ip) { |
3331 | ret = ftrace_match_addr(hash, ip, remove); | |
3332 | if (ret < 0) | |
3333 | goto out_regex_unlock; | |
3334 | } | |
33dc9b12 SR |
3335 | |
3336 | mutex_lock(&ftrace_lock); | |
41fb61c2 | 3337 | ret = ftrace_hash_move(ops, enable, orig_hash, hash); |
072126f4 SR |
3338 | if (!ret && ops->flags & FTRACE_OPS_FL_ENABLED |
3339 | && ftrace_enabled) | |
30fb6aa7 | 3340 | ftrace_run_update_code(FTRACE_UPDATE_CALLS); |
072126f4 | 3341 | |
33dc9b12 SR |
3342 | mutex_unlock(&ftrace_lock); |
3343 | ||
ac483c44 | 3344 | out_regex_unlock: |
41c52c0d | 3345 | mutex_unlock(&ftrace_regex_lock); |
33dc9b12 SR |
3346 | |
3347 | free_ftrace_hash(hash); | |
3348 | return ret; | |
41c52c0d SR |
3349 | } |
3350 | ||
647664ea MH |
3351 | static int |
3352 | ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove, | |
3353 | int reset, int enable) | |
3354 | { | |
3355 | return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable); | |
3356 | } | |
3357 | ||
3358 | /** | |
3359 | * ftrace_set_filter_ip - set a function to filter on in ftrace by address | |
3360 | * @ops - the ops to set the filter with | |
3361 | * @ip - the address to add to or remove from the filter. | |
3362 | * @remove - non zero to remove the ip from the filter | |
3363 | * @reset - non zero to reset all filters before applying this filter. | |
3364 | * | |
3365 | * Filters denote which functions should be enabled when tracing is enabled | |
3366 | * If @ip is NULL, it failes to update filter. | |
3367 | */ | |
3368 | int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, | |
3369 | int remove, int reset) | |
3370 | { | |
3371 | return ftrace_set_addr(ops, ip, remove, reset, 1); | |
3372 | } | |
3373 | EXPORT_SYMBOL_GPL(ftrace_set_filter_ip); | |
3374 | ||
3375 | static int | |
3376 | ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, | |
3377 | int reset, int enable) | |
3378 | { | |
3379 | return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable); | |
3380 | } | |
3381 | ||
77a2b37d SR |
3382 | /** |
3383 | * ftrace_set_filter - set a function to filter on in ftrace | |
936e074b SR |
3384 | * @ops - the ops to set the filter with |
3385 | * @buf - the string that holds the function filter text. | |
3386 | * @len - the length of the string. | |
3387 | * @reset - non zero to reset all filters before applying this filter. | |
3388 | * | |
3389 | * Filters denote which functions should be enabled when tracing is enabled. | |
3390 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
3391 | */ | |
ac483c44 | 3392 | int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
3393 | int len, int reset) |
3394 | { | |
ac483c44 | 3395 | return ftrace_set_regex(ops, buf, len, reset, 1); |
936e074b SR |
3396 | } |
3397 | EXPORT_SYMBOL_GPL(ftrace_set_filter); | |
3398 | ||
3399 | /** | |
3400 | * ftrace_set_notrace - set a function to not trace in ftrace | |
3401 | * @ops - the ops to set the notrace filter with | |
3402 | * @buf - the string that holds the function notrace text. | |
3403 | * @len - the length of the string. | |
3404 | * @reset - non zero to reset all filters before applying this filter. | |
3405 | * | |
3406 | * Notrace Filters denote which functions should not be enabled when tracing | |
3407 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
3408 | * for tracing. | |
3409 | */ | |
ac483c44 | 3410 | int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, |
936e074b SR |
3411 | int len, int reset) |
3412 | { | |
ac483c44 | 3413 | return ftrace_set_regex(ops, buf, len, reset, 0); |
936e074b SR |
3414 | } |
3415 | EXPORT_SYMBOL_GPL(ftrace_set_notrace); | |
3416 | /** | |
3417 | * ftrace_set_filter - set a function to filter on in ftrace | |
3418 | * @ops - the ops to set the filter with | |
77a2b37d SR |
3419 | * @buf - the string that holds the function filter text. |
3420 | * @len - the length of the string. | |
3421 | * @reset - non zero to reset all filters before applying this filter. | |
3422 | * | |
3423 | * Filters denote which functions should be enabled when tracing is enabled. | |
3424 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. | |
3425 | */ | |
936e074b | 3426 | void ftrace_set_global_filter(unsigned char *buf, int len, int reset) |
77a2b37d | 3427 | { |
f45948e8 | 3428 | ftrace_set_regex(&global_ops, buf, len, reset, 1); |
41c52c0d | 3429 | } |
936e074b | 3430 | EXPORT_SYMBOL_GPL(ftrace_set_global_filter); |
4eebcc81 | 3431 | |
41c52c0d SR |
3432 | /** |
3433 | * ftrace_set_notrace - set a function to not trace in ftrace | |
936e074b | 3434 | * @ops - the ops to set the notrace filter with |
41c52c0d SR |
3435 | * @buf - the string that holds the function notrace text. |
3436 | * @len - the length of the string. | |
3437 | * @reset - non zero to reset all filters before applying this filter. | |
3438 | * | |
3439 | * Notrace Filters denote which functions should not be enabled when tracing | |
3440 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled | |
3441 | * for tracing. | |
3442 | */ | |
936e074b | 3443 | void ftrace_set_global_notrace(unsigned char *buf, int len, int reset) |
41c52c0d | 3444 | { |
f45948e8 | 3445 | ftrace_set_regex(&global_ops, buf, len, reset, 0); |
77a2b37d | 3446 | } |
936e074b | 3447 | EXPORT_SYMBOL_GPL(ftrace_set_global_notrace); |
77a2b37d | 3448 | |
2af15d6a SR |
3449 | /* |
3450 | * command line interface to allow users to set filters on boot up. | |
3451 | */ | |
3452 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE | |
3453 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; | |
3454 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; | |
3455 | ||
3456 | static int __init set_ftrace_notrace(char *str) | |
3457 | { | |
3458 | strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); | |
3459 | return 1; | |
3460 | } | |
3461 | __setup("ftrace_notrace=", set_ftrace_notrace); | |
3462 | ||
3463 | static int __init set_ftrace_filter(char *str) | |
3464 | { | |
3465 | strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); | |
3466 | return 1; | |
3467 | } | |
3468 | __setup("ftrace_filter=", set_ftrace_filter); | |
3469 | ||
369bc18f | 3470 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
f6060f46 | 3471 | static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata; |
801c29fd SR |
3472 | static int ftrace_set_func(unsigned long *array, int *idx, char *buffer); |
3473 | ||
369bc18f SA |
3474 | static int __init set_graph_function(char *str) |
3475 | { | |
06f43d66 | 3476 | strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE); |
369bc18f SA |
3477 | return 1; |
3478 | } | |
3479 | __setup("ftrace_graph_filter=", set_graph_function); | |
3480 | ||
3481 | static void __init set_ftrace_early_graph(char *buf) | |
3482 | { | |
3483 | int ret; | |
3484 | char *func; | |
3485 | ||
3486 | while (buf) { | |
3487 | func = strsep(&buf, ","); | |
3488 | /* we allow only one expression at a time */ | |
3489 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, | |
3490 | func); | |
3491 | if (ret) | |
3492 | printk(KERN_DEBUG "ftrace: function %s not " | |
3493 | "traceable\n", func); | |
3494 | } | |
3495 | } | |
3496 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
3497 | ||
2a85a37f SR |
3498 | void __init |
3499 | ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable) | |
2af15d6a SR |
3500 | { |
3501 | char *func; | |
3502 | ||
3503 | while (buf) { | |
3504 | func = strsep(&buf, ","); | |
f45948e8 | 3505 | ftrace_set_regex(ops, func, strlen(func), 0, enable); |
2af15d6a SR |
3506 | } |
3507 | } | |
3508 | ||
3509 | static void __init set_ftrace_early_filters(void) | |
3510 | { | |
3511 | if (ftrace_filter_buf[0]) | |
2a85a37f | 3512 | ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1); |
2af15d6a | 3513 | if (ftrace_notrace_buf[0]) |
2a85a37f | 3514 | ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0); |
369bc18f SA |
3515 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
3516 | if (ftrace_graph_buf[0]) | |
3517 | set_ftrace_early_graph(ftrace_graph_buf); | |
3518 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
2af15d6a SR |
3519 | } |
3520 | ||
fc13cb0c | 3521 | int ftrace_regex_release(struct inode *inode, struct file *file) |
5072c59f SR |
3522 | { |
3523 | struct seq_file *m = (struct seq_file *)file->private_data; | |
3524 | struct ftrace_iterator *iter; | |
33dc9b12 | 3525 | struct ftrace_hash **orig_hash; |
689fd8b6 | 3526 | struct trace_parser *parser; |
ed926f9b | 3527 | int filter_hash; |
33dc9b12 | 3528 | int ret; |
5072c59f | 3529 | |
41c52c0d | 3530 | mutex_lock(&ftrace_regex_lock); |
5072c59f SR |
3531 | if (file->f_mode & FMODE_READ) { |
3532 | iter = m->private; | |
3533 | ||
3534 | seq_release(inode, file); | |
3535 | } else | |
3536 | iter = file->private_data; | |
3537 | ||
689fd8b6 | 3538 | parser = &iter->parser; |
3539 | if (trace_parser_loaded(parser)) { | |
3540 | parser->buffer[parser->idx] = 0; | |
1cf41dd7 | 3541 | ftrace_match_records(iter->hash, parser->buffer, parser->idx); |
5072c59f SR |
3542 | } |
3543 | ||
689fd8b6 | 3544 | trace_parser_put(parser); |
689fd8b6 | 3545 | |
058e297d | 3546 | if (file->f_mode & FMODE_WRITE) { |
ed926f9b SR |
3547 | filter_hash = !!(iter->flags & FTRACE_ITER_FILTER); |
3548 | ||
3549 | if (filter_hash) | |
33dc9b12 | 3550 | orig_hash = &iter->ops->filter_hash; |
ed926f9b SR |
3551 | else |
3552 | orig_hash = &iter->ops->notrace_hash; | |
33dc9b12 | 3553 | |
058e297d | 3554 | mutex_lock(&ftrace_lock); |
41fb61c2 SR |
3555 | ret = ftrace_hash_move(iter->ops, filter_hash, |
3556 | orig_hash, iter->hash); | |
3557 | if (!ret && (iter->ops->flags & FTRACE_OPS_FL_ENABLED) | |
3558 | && ftrace_enabled) | |
30fb6aa7 | 3559 | ftrace_run_update_code(FTRACE_UPDATE_CALLS); |
41fb61c2 | 3560 | |
058e297d SR |
3561 | mutex_unlock(&ftrace_lock); |
3562 | } | |
33dc9b12 SR |
3563 | free_ftrace_hash(iter->hash); |
3564 | kfree(iter); | |
058e297d | 3565 | |
41c52c0d | 3566 | mutex_unlock(&ftrace_regex_lock); |
5072c59f SR |
3567 | return 0; |
3568 | } | |
3569 | ||
5e2336a0 | 3570 | static const struct file_operations ftrace_avail_fops = { |
5072c59f SR |
3571 | .open = ftrace_avail_open, |
3572 | .read = seq_read, | |
3573 | .llseek = seq_lseek, | |
3be04b47 | 3574 | .release = seq_release_private, |
5072c59f SR |
3575 | }; |
3576 | ||
647bcd03 SR |
3577 | static const struct file_operations ftrace_enabled_fops = { |
3578 | .open = ftrace_enabled_open, | |
3579 | .read = seq_read, | |
3580 | .llseek = seq_lseek, | |
3581 | .release = seq_release_private, | |
3582 | }; | |
3583 | ||
5e2336a0 | 3584 | static const struct file_operations ftrace_filter_fops = { |
5072c59f | 3585 | .open = ftrace_filter_open, |
850a80cf | 3586 | .read = seq_read, |
5072c59f | 3587 | .write = ftrace_filter_write, |
98c4fd04 | 3588 | .llseek = ftrace_regex_lseek, |
1cf41dd7 | 3589 | .release = ftrace_regex_release, |
5072c59f SR |
3590 | }; |
3591 | ||
5e2336a0 | 3592 | static const struct file_operations ftrace_notrace_fops = { |
41c52c0d | 3593 | .open = ftrace_notrace_open, |
850a80cf | 3594 | .read = seq_read, |
41c52c0d SR |
3595 | .write = ftrace_notrace_write, |
3596 | .llseek = ftrace_regex_lseek, | |
1cf41dd7 | 3597 | .release = ftrace_regex_release, |
41c52c0d SR |
3598 | }; |
3599 | ||
ea4e2bc4 SR |
3600 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
3601 | ||
3602 | static DEFINE_MUTEX(graph_lock); | |
3603 | ||
3604 | int ftrace_graph_count; | |
c7c6b1fe | 3605 | int ftrace_graph_filter_enabled; |
ea4e2bc4 SR |
3606 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
3607 | ||
3608 | static void * | |
85951842 | 3609 | __g_next(struct seq_file *m, loff_t *pos) |
ea4e2bc4 | 3610 | { |
85951842 | 3611 | if (*pos >= ftrace_graph_count) |
ea4e2bc4 | 3612 | return NULL; |
a4ec5e0c | 3613 | return &ftrace_graph_funcs[*pos]; |
85951842 | 3614 | } |
ea4e2bc4 | 3615 | |
85951842 LZ |
3616 | static void * |
3617 | g_next(struct seq_file *m, void *v, loff_t *pos) | |
3618 | { | |
3619 | (*pos)++; | |
3620 | return __g_next(m, pos); | |
ea4e2bc4 SR |
3621 | } |
3622 | ||
3623 | static void *g_start(struct seq_file *m, loff_t *pos) | |
3624 | { | |
ea4e2bc4 SR |
3625 | mutex_lock(&graph_lock); |
3626 | ||
f9349a8f | 3627 | /* Nothing, tell g_show to print all functions are enabled */ |
c7c6b1fe | 3628 | if (!ftrace_graph_filter_enabled && !*pos) |
f9349a8f FW |
3629 | return (void *)1; |
3630 | ||
85951842 | 3631 | return __g_next(m, pos); |
ea4e2bc4 SR |
3632 | } |
3633 | ||
3634 | static void g_stop(struct seq_file *m, void *p) | |
3635 | { | |
3636 | mutex_unlock(&graph_lock); | |
3637 | } | |
3638 | ||
3639 | static int g_show(struct seq_file *m, void *v) | |
3640 | { | |
3641 | unsigned long *ptr = v; | |
ea4e2bc4 SR |
3642 | |
3643 | if (!ptr) | |
3644 | return 0; | |
3645 | ||
f9349a8f FW |
3646 | if (ptr == (unsigned long *)1) { |
3647 | seq_printf(m, "#### all functions enabled ####\n"); | |
3648 | return 0; | |
3649 | } | |
3650 | ||
b375a11a | 3651 | seq_printf(m, "%ps\n", (void *)*ptr); |
ea4e2bc4 SR |
3652 | |
3653 | return 0; | |
3654 | } | |
3655 | ||
88e9d34c | 3656 | static const struct seq_operations ftrace_graph_seq_ops = { |
ea4e2bc4 SR |
3657 | .start = g_start, |
3658 | .next = g_next, | |
3659 | .stop = g_stop, | |
3660 | .show = g_show, | |
3661 | }; | |
3662 | ||
3663 | static int | |
3664 | ftrace_graph_open(struct inode *inode, struct file *file) | |
3665 | { | |
3666 | int ret = 0; | |
3667 | ||
3668 | if (unlikely(ftrace_disabled)) | |
3669 | return -ENODEV; | |
3670 | ||
3671 | mutex_lock(&graph_lock); | |
3672 | if ((file->f_mode & FMODE_WRITE) && | |
8650ae32 | 3673 | (file->f_flags & O_TRUNC)) { |
c7c6b1fe | 3674 | ftrace_graph_filter_enabled = 0; |
ea4e2bc4 SR |
3675 | ftrace_graph_count = 0; |
3676 | memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); | |
3677 | } | |
a4ec5e0c | 3678 | mutex_unlock(&graph_lock); |
ea4e2bc4 | 3679 | |
a4ec5e0c | 3680 | if (file->f_mode & FMODE_READ) |
ea4e2bc4 | 3681 | ret = seq_open(file, &ftrace_graph_seq_ops); |
ea4e2bc4 SR |
3682 | |
3683 | return ret; | |
3684 | } | |
3685 | ||
87827111 LZ |
3686 | static int |
3687 | ftrace_graph_release(struct inode *inode, struct file *file) | |
3688 | { | |
3689 | if (file->f_mode & FMODE_READ) | |
3690 | seq_release(inode, file); | |
3691 | return 0; | |
3692 | } | |
3693 | ||
ea4e2bc4 | 3694 | static int |
f9349a8f | 3695 | ftrace_set_func(unsigned long *array, int *idx, char *buffer) |
ea4e2bc4 | 3696 | { |
ea4e2bc4 SR |
3697 | struct dyn_ftrace *rec; |
3698 | struct ftrace_page *pg; | |
f9349a8f | 3699 | int search_len; |
c7c6b1fe | 3700 | int fail = 1; |
f9349a8f FW |
3701 | int type, not; |
3702 | char *search; | |
3703 | bool exists; | |
3704 | int i; | |
ea4e2bc4 | 3705 | |
f9349a8f | 3706 | /* decode regex */ |
3f6fe06d | 3707 | type = filter_parse_regex(buffer, strlen(buffer), &search, ¬); |
c7c6b1fe LZ |
3708 | if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS) |
3709 | return -EBUSY; | |
f9349a8f FW |
3710 | |
3711 | search_len = strlen(search); | |
3712 | ||
52baf119 | 3713 | mutex_lock(&ftrace_lock); |
45a4a237 SR |
3714 | |
3715 | if (unlikely(ftrace_disabled)) { | |
3716 | mutex_unlock(&ftrace_lock); | |
3717 | return -ENODEV; | |
3718 | } | |
3719 | ||
265c831c SR |
3720 | do_for_each_ftrace_rec(pg, rec) { |
3721 | ||
b9df92d2 | 3722 | if (ftrace_match_record(rec, NULL, search, search_len, type)) { |
c7c6b1fe | 3723 | /* if it is in the array */ |
f9349a8f | 3724 | exists = false; |
c7c6b1fe | 3725 | for (i = 0; i < *idx; i++) { |
f9349a8f FW |
3726 | if (array[i] == rec->ip) { |
3727 | exists = true; | |
265c831c SR |
3728 | break; |
3729 | } | |
c7c6b1fe LZ |
3730 | } |
3731 | ||
3732 | if (!not) { | |
3733 | fail = 0; | |
3734 | if (!exists) { | |
3735 | array[(*idx)++] = rec->ip; | |
3736 | if (*idx >= FTRACE_GRAPH_MAX_FUNCS) | |
3737 | goto out; | |
3738 | } | |
3739 | } else { | |
3740 | if (exists) { | |
3741 | array[i] = array[--(*idx)]; | |
3742 | array[*idx] = 0; | |
3743 | fail = 0; | |
3744 | } | |
3745 | } | |
ea4e2bc4 | 3746 | } |
265c831c | 3747 | } while_for_each_ftrace_rec(); |
c7c6b1fe | 3748 | out: |
52baf119 | 3749 | mutex_unlock(&ftrace_lock); |
ea4e2bc4 | 3750 | |
c7c6b1fe LZ |
3751 | if (fail) |
3752 | return -EINVAL; | |
3753 | ||
3754 | ftrace_graph_filter_enabled = 1; | |
3755 | return 0; | |
ea4e2bc4 SR |
3756 | } |
3757 | ||
3758 | static ssize_t | |
3759 | ftrace_graph_write(struct file *file, const char __user *ubuf, | |
3760 | size_t cnt, loff_t *ppos) | |
3761 | { | |
689fd8b6 | 3762 | struct trace_parser parser; |
4ba7978e | 3763 | ssize_t read, ret; |
ea4e2bc4 | 3764 | |
c7c6b1fe | 3765 | if (!cnt) |
ea4e2bc4 SR |
3766 | return 0; |
3767 | ||
3768 | mutex_lock(&graph_lock); | |
3769 | ||
689fd8b6 | 3770 | if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) { |
3771 | ret = -ENOMEM; | |
1eb90f13 | 3772 | goto out_unlock; |
ea4e2bc4 SR |
3773 | } |
3774 | ||
689fd8b6 | 3775 | read = trace_get_user(&parser, ubuf, cnt, ppos); |
ea4e2bc4 | 3776 | |
4ba7978e | 3777 | if (read >= 0 && trace_parser_loaded((&parser))) { |
689fd8b6 | 3778 | parser.buffer[parser.idx] = 0; |
3779 | ||
3780 | /* we allow only one expression at a time */ | |
a4ec5e0c | 3781 | ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count, |
689fd8b6 | 3782 | parser.buffer); |
ea4e2bc4 | 3783 | if (ret) |
1eb90f13 | 3784 | goto out_free; |
ea4e2bc4 | 3785 | } |
ea4e2bc4 SR |
3786 | |
3787 | ret = read; | |
1eb90f13 LZ |
3788 | |
3789 | out_free: | |
689fd8b6 | 3790 | trace_parser_put(&parser); |
1eb90f13 | 3791 | out_unlock: |
ea4e2bc4 SR |
3792 | mutex_unlock(&graph_lock); |
3793 | ||
3794 | return ret; | |
3795 | } | |
3796 | ||
3797 | static const struct file_operations ftrace_graph_fops = { | |
87827111 LZ |
3798 | .open = ftrace_graph_open, |
3799 | .read = seq_read, | |
3800 | .write = ftrace_graph_write, | |
3801 | .release = ftrace_graph_release, | |
6038f373 | 3802 | .llseek = seq_lseek, |
ea4e2bc4 SR |
3803 | }; |
3804 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | |
3805 | ||
df4fc315 | 3806 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
5072c59f | 3807 | { |
5072c59f | 3808 | |
5452af66 FW |
3809 | trace_create_file("available_filter_functions", 0444, |
3810 | d_tracer, NULL, &ftrace_avail_fops); | |
5072c59f | 3811 | |
647bcd03 SR |
3812 | trace_create_file("enabled_functions", 0444, |
3813 | d_tracer, NULL, &ftrace_enabled_fops); | |
3814 | ||
5452af66 FW |
3815 | trace_create_file("set_ftrace_filter", 0644, d_tracer, |
3816 | NULL, &ftrace_filter_fops); | |
41c52c0d | 3817 | |
5452af66 | 3818 | trace_create_file("set_ftrace_notrace", 0644, d_tracer, |
41c52c0d | 3819 | NULL, &ftrace_notrace_fops); |
ad90c0e3 | 3820 | |
ea4e2bc4 | 3821 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
5452af66 | 3822 | trace_create_file("set_graph_function", 0444, d_tracer, |
ea4e2bc4 SR |
3823 | NULL, |
3824 | &ftrace_graph_fops); | |
ea4e2bc4 SR |
3825 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
3826 | ||
5072c59f SR |
3827 | return 0; |
3828 | } | |
3829 | ||
9fd49328 | 3830 | static int ftrace_cmp_ips(const void *a, const void *b) |
68950619 | 3831 | { |
9fd49328 SR |
3832 | const unsigned long *ipa = a; |
3833 | const unsigned long *ipb = b; | |
68950619 | 3834 | |
9fd49328 SR |
3835 | if (*ipa > *ipb) |
3836 | return 1; | |
3837 | if (*ipa < *ipb) | |
3838 | return -1; | |
3839 | return 0; | |
3840 | } | |
3841 | ||
3842 | static void ftrace_swap_ips(void *a, void *b, int size) | |
3843 | { | |
3844 | unsigned long *ipa = a; | |
3845 | unsigned long *ipb = b; | |
3846 | unsigned long t; | |
3847 | ||
3848 | t = *ipa; | |
3849 | *ipa = *ipb; | |
3850 | *ipb = t; | |
68950619 SR |
3851 | } |
3852 | ||
5cb084bb | 3853 | static int ftrace_process_locs(struct module *mod, |
31e88909 | 3854 | unsigned long *start, |
68bf21aa SR |
3855 | unsigned long *end) |
3856 | { | |
706c81f8 | 3857 | struct ftrace_page *start_pg; |
a7900875 | 3858 | struct ftrace_page *pg; |
706c81f8 | 3859 | struct dyn_ftrace *rec; |
a7900875 | 3860 | unsigned long count; |
68bf21aa SR |
3861 | unsigned long *p; |
3862 | unsigned long addr; | |
4376cac6 | 3863 | unsigned long flags = 0; /* Shut up gcc */ |
a7900875 SR |
3864 | int ret = -ENOMEM; |
3865 | ||
3866 | count = end - start; | |
3867 | ||
3868 | if (!count) | |
3869 | return 0; | |
3870 | ||
9fd49328 SR |
3871 | sort(start, count, sizeof(*start), |
3872 | ftrace_cmp_ips, ftrace_swap_ips); | |
3873 | ||
706c81f8 SR |
3874 | start_pg = ftrace_allocate_pages(count); |
3875 | if (!start_pg) | |
a7900875 | 3876 | return -ENOMEM; |
68bf21aa | 3877 | |
e6ea44e9 | 3878 | mutex_lock(&ftrace_lock); |
a7900875 | 3879 | |
32082309 SR |
3880 | /* |
3881 | * Core and each module needs their own pages, as | |
3882 | * modules will free them when they are removed. | |
3883 | * Force a new page to be allocated for modules. | |
3884 | */ | |
a7900875 SR |
3885 | if (!mod) { |
3886 | WARN_ON(ftrace_pages || ftrace_pages_start); | |
3887 | /* First initialization */ | |
706c81f8 | 3888 | ftrace_pages = ftrace_pages_start = start_pg; |
a7900875 | 3889 | } else { |
32082309 | 3890 | if (!ftrace_pages) |
a7900875 | 3891 | goto out; |
32082309 | 3892 | |
a7900875 SR |
3893 | if (WARN_ON(ftrace_pages->next)) { |
3894 | /* Hmm, we have free pages? */ | |
3895 | while (ftrace_pages->next) | |
3896 | ftrace_pages = ftrace_pages->next; | |
32082309 | 3897 | } |
a7900875 | 3898 | |
706c81f8 | 3899 | ftrace_pages->next = start_pg; |
32082309 SR |
3900 | } |
3901 | ||
68bf21aa | 3902 | p = start; |
706c81f8 | 3903 | pg = start_pg; |
68bf21aa SR |
3904 | while (p < end) { |
3905 | addr = ftrace_call_adjust(*p++); | |
20e5227e SR |
3906 | /* |
3907 | * Some architecture linkers will pad between | |
3908 | * the different mcount_loc sections of different | |
3909 | * object files to satisfy alignments. | |
3910 | * Skip any NULL pointers. | |
3911 | */ | |
3912 | if (!addr) | |
3913 | continue; | |
706c81f8 SR |
3914 | |
3915 | if (pg->index == pg->size) { | |
3916 | /* We should have allocated enough */ | |
3917 | if (WARN_ON(!pg->next)) | |
3918 | break; | |
3919 | pg = pg->next; | |
3920 | } | |
3921 | ||
3922 | rec = &pg->records[pg->index++]; | |
3923 | rec->ip = addr; | |
68bf21aa SR |
3924 | } |
3925 | ||
706c81f8 SR |
3926 | /* We should have used all pages */ |
3927 | WARN_ON(pg->next); | |
3928 | ||
3929 | /* Assign the last page to ftrace_pages */ | |
3930 | ftrace_pages = pg; | |
3931 | ||
85ae32ae | 3932 | /* These new locations need to be initialized */ |
706c81f8 | 3933 | ftrace_new_pgs = start_pg; |
85ae32ae | 3934 | |
a4f18ed1 | 3935 | /* |
4376cac6 SR |
3936 | * We only need to disable interrupts on start up |
3937 | * because we are modifying code that an interrupt | |
3938 | * may execute, and the modification is not atomic. | |
3939 | * But for modules, nothing runs the code we modify | |
3940 | * until we are finished with it, and there's no | |
3941 | * reason to cause large interrupt latencies while we do it. | |
a4f18ed1 | 3942 | */ |
4376cac6 SR |
3943 | if (!mod) |
3944 | local_irq_save(flags); | |
31e88909 | 3945 | ftrace_update_code(mod); |
4376cac6 SR |
3946 | if (!mod) |
3947 | local_irq_restore(flags); | |
a7900875 SR |
3948 | ret = 0; |
3949 | out: | |
e6ea44e9 | 3950 | mutex_unlock(&ftrace_lock); |
68bf21aa | 3951 | |
a7900875 | 3952 | return ret; |
68bf21aa SR |
3953 | } |
3954 | ||
93eb677d | 3955 | #ifdef CONFIG_MODULES |
32082309 SR |
3956 | |
3957 | #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next) | |
3958 | ||
e7247a15 | 3959 | void ftrace_release_mod(struct module *mod) |
93eb677d SR |
3960 | { |
3961 | struct dyn_ftrace *rec; | |
32082309 | 3962 | struct ftrace_page **last_pg; |
93eb677d | 3963 | struct ftrace_page *pg; |
a7900875 | 3964 | int order; |
93eb677d | 3965 | |
45a4a237 SR |
3966 | mutex_lock(&ftrace_lock); |
3967 | ||
e7247a15 | 3968 | if (ftrace_disabled) |
45a4a237 | 3969 | goto out_unlock; |
93eb677d | 3970 | |
32082309 SR |
3971 | /* |
3972 | * Each module has its own ftrace_pages, remove | |
3973 | * them from the list. | |
3974 | */ | |
3975 | last_pg = &ftrace_pages_start; | |
3976 | for (pg = ftrace_pages_start; pg; pg = *last_pg) { | |
3977 | rec = &pg->records[0]; | |
e7247a15 | 3978 | if (within_module_core(rec->ip, mod)) { |
93eb677d | 3979 | /* |
32082309 SR |
3980 | * As core pages are first, the first |
3981 | * page should never be a module page. | |
93eb677d | 3982 | */ |
32082309 SR |
3983 | if (WARN_ON(pg == ftrace_pages_start)) |
3984 | goto out_unlock; | |
3985 | ||
3986 | /* Check if we are deleting the last page */ | |
3987 | if (pg == ftrace_pages) | |
3988 | ftrace_pages = next_to_ftrace_page(last_pg); | |
3989 | ||
3990 | *last_pg = pg->next; | |
a7900875 SR |
3991 | order = get_count_order(pg->size / ENTRIES_PER_PAGE); |
3992 | free_pages((unsigned long)pg->records, order); | |
3993 | kfree(pg); | |
32082309 SR |
3994 | } else |
3995 | last_pg = &pg->next; | |
3996 | } | |
45a4a237 | 3997 | out_unlock: |
93eb677d SR |
3998 | mutex_unlock(&ftrace_lock); |
3999 | } | |
4000 | ||
4001 | static void ftrace_init_module(struct module *mod, | |
4002 | unsigned long *start, unsigned long *end) | |
90d595fe | 4003 | { |
00fd61ae | 4004 | if (ftrace_disabled || start == end) |
fed1939c | 4005 | return; |
5cb084bb | 4006 | ftrace_process_locs(mod, start, end); |
90d595fe SR |
4007 | } |
4008 | ||
93eb677d SR |
4009 | static int ftrace_module_notify(struct notifier_block *self, |
4010 | unsigned long val, void *data) | |
4011 | { | |
4012 | struct module *mod = data; | |
4013 | ||
4014 | switch (val) { | |
4015 | case MODULE_STATE_COMING: | |
4016 | ftrace_init_module(mod, mod->ftrace_callsites, | |
4017 | mod->ftrace_callsites + | |
4018 | mod->num_ftrace_callsites); | |
4019 | break; | |
4020 | case MODULE_STATE_GOING: | |
e7247a15 | 4021 | ftrace_release_mod(mod); |
93eb677d SR |
4022 | break; |
4023 | } | |
4024 | ||
4025 | return 0; | |
4026 | } | |
4027 | #else | |
4028 | static int ftrace_module_notify(struct notifier_block *self, | |
4029 | unsigned long val, void *data) | |
4030 | { | |
4031 | return 0; | |
4032 | } | |
4033 | #endif /* CONFIG_MODULES */ | |
4034 | ||
4035 | struct notifier_block ftrace_module_nb = { | |
4036 | .notifier_call = ftrace_module_notify, | |
c1bf08ac | 4037 | .priority = INT_MAX, /* Run before anything that can use kprobes */ |
93eb677d SR |
4038 | }; |
4039 | ||
68bf21aa SR |
4040 | extern unsigned long __start_mcount_loc[]; |
4041 | extern unsigned long __stop_mcount_loc[]; | |
4042 | ||
4043 | void __init ftrace_init(void) | |
4044 | { | |
4045 | unsigned long count, addr, flags; | |
4046 | int ret; | |
4047 | ||
4048 | /* Keep the ftrace pointer to the stub */ | |
4049 | addr = (unsigned long)ftrace_stub; | |
4050 | ||
4051 | local_irq_save(flags); | |
4052 | ftrace_dyn_arch_init(&addr); | |
4053 | local_irq_restore(flags); | |
4054 | ||
4055 | /* ftrace_dyn_arch_init places the return code in addr */ | |
4056 | if (addr) | |
4057 | goto failed; | |
4058 | ||
4059 | count = __stop_mcount_loc - __start_mcount_loc; | |
4060 | ||
4061 | ret = ftrace_dyn_table_alloc(count); | |
4062 | if (ret) | |
4063 | goto failed; | |
4064 | ||
4065 | last_ftrace_enabled = ftrace_enabled = 1; | |
4066 | ||
5cb084bb | 4067 | ret = ftrace_process_locs(NULL, |
31e88909 | 4068 | __start_mcount_loc, |
68bf21aa SR |
4069 | __stop_mcount_loc); |
4070 | ||
93eb677d | 4071 | ret = register_module_notifier(&ftrace_module_nb); |
24ed0c4b | 4072 | if (ret) |
93eb677d SR |
4073 | pr_warning("Failed to register trace ftrace module notifier\n"); |
4074 | ||
2af15d6a SR |
4075 | set_ftrace_early_filters(); |
4076 | ||
68bf21aa SR |
4077 | return; |
4078 | failed: | |
4079 | ftrace_disabled = 1; | |
4080 | } | |
68bf21aa | 4081 | |
3d083395 | 4082 | #else |
0b6e4d56 | 4083 | |
2b499381 | 4084 | static struct ftrace_ops global_ops = { |
bd69c30b | 4085 | .func = ftrace_stub, |
4740974a | 4086 | .flags = FTRACE_OPS_FL_RECURSION_SAFE, |
bd69c30b SR |
4087 | }; |
4088 | ||
0b6e4d56 FW |
4089 | static int __init ftrace_nodyn_init(void) |
4090 | { | |
4091 | ftrace_enabled = 1; | |
4092 | return 0; | |
4093 | } | |
6f415672 | 4094 | core_initcall(ftrace_nodyn_init); |
0b6e4d56 | 4095 | |
df4fc315 SR |
4096 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
4097 | static inline void ftrace_startup_enable(int command) { } | |
5a45cfe1 | 4098 | /* Keep as macros so we do not need to define the commands */ |
3b6cfdb1 SR |
4099 | # define ftrace_startup(ops, command) \ |
4100 | ({ \ | |
4101 | (ops)->flags |= FTRACE_OPS_FL_ENABLED; \ | |
4102 | 0; \ | |
4103 | }) | |
bd69c30b | 4104 | # define ftrace_shutdown(ops, command) do { } while (0) |
c7aafc54 IM |
4105 | # define ftrace_startup_sysctl() do { } while (0) |
4106 | # define ftrace_shutdown_sysctl() do { } while (0) | |
b848914c SR |
4107 | |
4108 | static inline int | |
4109 | ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip) | |
4110 | { | |
4111 | return 1; | |
4112 | } | |
4113 | ||
3d083395 SR |
4114 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
4115 | ||
e248491a | 4116 | static void |
2f5f6ad9 | 4117 | ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip, |
a1e2e31d | 4118 | struct ftrace_ops *op, struct pt_regs *regs) |
e248491a | 4119 | { |
e248491a JO |
4120 | if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT))) |
4121 | return; | |
4122 | ||
4123 | /* | |
4124 | * Some of the ops may be dynamically allocated, | |
4125 | * they must be freed after a synchronize_sched(). | |
4126 | */ | |
4127 | preempt_disable_notrace(); | |
4128 | trace_recursion_set(TRACE_CONTROL_BIT); | |
0a016409 | 4129 | do_for_each_ftrace_op(op, ftrace_control_list) { |
e248491a JO |
4130 | if (!ftrace_function_local_disabled(op) && |
4131 | ftrace_ops_test(op, ip)) | |
a1e2e31d | 4132 | op->func(ip, parent_ip, op, regs); |
0a016409 | 4133 | } while_for_each_ftrace_op(op); |
e248491a JO |
4134 | trace_recursion_clear(TRACE_CONTROL_BIT); |
4135 | preempt_enable_notrace(); | |
4136 | } | |
4137 | ||
4138 | static struct ftrace_ops control_ops = { | |
4139 | .func = ftrace_ops_control_func, | |
4740974a | 4140 | .flags = FTRACE_OPS_FL_RECURSION_SAFE, |
e248491a JO |
4141 | }; |
4142 | ||
2f5f6ad9 SR |
4143 | static inline void |
4144 | __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 4145 | struct ftrace_ops *ignored, struct pt_regs *regs) |
b848914c | 4146 | { |
cdbe61bf | 4147 | struct ftrace_ops *op; |
c29f122c | 4148 | unsigned int bit; |
b848914c | 4149 | |
ccf3672d SR |
4150 | if (function_trace_stop) |
4151 | return; | |
4152 | ||
c29f122c SR |
4153 | if (in_interrupt()) { |
4154 | if (in_nmi()) | |
4155 | bit = TRACE_INTERNAL_NMI_BIT; | |
4156 | ||
4157 | else if (in_irq()) | |
4158 | bit = TRACE_INTERNAL_IRQ_BIT; | |
4159 | else | |
4160 | bit = TRACE_INTERNAL_SIRQ_BIT; | |
4161 | } else | |
4162 | bit = TRACE_INTERNAL_BIT; | |
4163 | ||
4164 | if (unlikely(trace_recursion_test(bit))) | |
4165 | return; | |
4166 | ||
4167 | trace_recursion_set(bit); | |
b1cff0ad | 4168 | |
cdbe61bf SR |
4169 | /* |
4170 | * Some of the ops may be dynamically allocated, | |
4171 | * they must be freed after a synchronize_sched(). | |
4172 | */ | |
4173 | preempt_disable_notrace(); | |
0a016409 | 4174 | do_for_each_ftrace_op(op, ftrace_ops_list) { |
b848914c | 4175 | if (ftrace_ops_test(op, ip)) |
a1e2e31d | 4176 | op->func(ip, parent_ip, op, regs); |
0a016409 | 4177 | } while_for_each_ftrace_op(op); |
cdbe61bf | 4178 | preempt_enable_notrace(); |
c29f122c | 4179 | trace_recursion_clear(bit); |
b848914c SR |
4180 | } |
4181 | ||
2f5f6ad9 SR |
4182 | /* |
4183 | * Some archs only support passing ip and parent_ip. Even though | |
4184 | * the list function ignores the op parameter, we do not want any | |
4185 | * C side effects, where a function is called without the caller | |
4186 | * sending a third parameter. | |
a1e2e31d SR |
4187 | * Archs are to support both the regs and ftrace_ops at the same time. |
4188 | * If they support ftrace_ops, it is assumed they support regs. | |
4189 | * If call backs want to use regs, they must either check for regs | |
06aeaaea MH |
4190 | * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS. |
4191 | * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved. | |
a1e2e31d SR |
4192 | * An architecture can pass partial regs with ftrace_ops and still |
4193 | * set the ARCH_SUPPORT_FTARCE_OPS. | |
2f5f6ad9 SR |
4194 | */ |
4195 | #if ARCH_SUPPORTS_FTRACE_OPS | |
4196 | static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, | |
a1e2e31d | 4197 | struct ftrace_ops *op, struct pt_regs *regs) |
2f5f6ad9 | 4198 | { |
a1e2e31d | 4199 | __ftrace_ops_list_func(ip, parent_ip, NULL, regs); |
2f5f6ad9 SR |
4200 | } |
4201 | #else | |
4202 | static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip) | |
4203 | { | |
a1e2e31d | 4204 | __ftrace_ops_list_func(ip, parent_ip, NULL, NULL); |
2f5f6ad9 SR |
4205 | } |
4206 | #endif | |
4207 | ||
e32d8956 | 4208 | static void clear_ftrace_swapper(void) |
978f3a45 SR |
4209 | { |
4210 | struct task_struct *p; | |
e32d8956 | 4211 | int cpu; |
978f3a45 | 4212 | |
e32d8956 SR |
4213 | get_online_cpus(); |
4214 | for_each_online_cpu(cpu) { | |
4215 | p = idle_task(cpu); | |
978f3a45 | 4216 | clear_tsk_trace_trace(p); |
e32d8956 SR |
4217 | } |
4218 | put_online_cpus(); | |
4219 | } | |
978f3a45 | 4220 | |
e32d8956 SR |
4221 | static void set_ftrace_swapper(void) |
4222 | { | |
4223 | struct task_struct *p; | |
4224 | int cpu; | |
4225 | ||
4226 | get_online_cpus(); | |
4227 | for_each_online_cpu(cpu) { | |
4228 | p = idle_task(cpu); | |
4229 | set_tsk_trace_trace(p); | |
4230 | } | |
4231 | put_online_cpus(); | |
978f3a45 SR |
4232 | } |
4233 | ||
e32d8956 SR |
4234 | static void clear_ftrace_pid(struct pid *pid) |
4235 | { | |
4236 | struct task_struct *p; | |
4237 | ||
229c4ef8 | 4238 | rcu_read_lock(); |
e32d8956 SR |
4239 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
4240 | clear_tsk_trace_trace(p); | |
4241 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 ON |
4242 | rcu_read_unlock(); |
4243 | ||
e32d8956 SR |
4244 | put_pid(pid); |
4245 | } | |
4246 | ||
4247 | static void set_ftrace_pid(struct pid *pid) | |
978f3a45 SR |
4248 | { |
4249 | struct task_struct *p; | |
4250 | ||
229c4ef8 | 4251 | rcu_read_lock(); |
978f3a45 SR |
4252 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
4253 | set_tsk_trace_trace(p); | |
4254 | } while_each_pid_task(pid, PIDTYPE_PID, p); | |
229c4ef8 | 4255 | rcu_read_unlock(); |
978f3a45 SR |
4256 | } |
4257 | ||
756d17ee | 4258 | static void clear_ftrace_pid_task(struct pid *pid) |
e32d8956 | 4259 | { |
756d17ee | 4260 | if (pid == ftrace_swapper_pid) |
e32d8956 SR |
4261 | clear_ftrace_swapper(); |
4262 | else | |
756d17ee | 4263 | clear_ftrace_pid(pid); |
e32d8956 SR |
4264 | } |
4265 | ||
4266 | static void set_ftrace_pid_task(struct pid *pid) | |
4267 | { | |
4268 | if (pid == ftrace_swapper_pid) | |
4269 | set_ftrace_swapper(); | |
4270 | else | |
4271 | set_ftrace_pid(pid); | |
4272 | } | |
4273 | ||
756d17ee | 4274 | static int ftrace_pid_add(int p) |
df4fc315 | 4275 | { |
978f3a45 | 4276 | struct pid *pid; |
756d17ee | 4277 | struct ftrace_pid *fpid; |
4278 | int ret = -EINVAL; | |
df4fc315 | 4279 | |
756d17ee | 4280 | mutex_lock(&ftrace_lock); |
df4fc315 | 4281 | |
756d17ee | 4282 | if (!p) |
4283 | pid = ftrace_swapper_pid; | |
4284 | else | |
4285 | pid = find_get_pid(p); | |
df4fc315 | 4286 | |
756d17ee | 4287 | if (!pid) |
4288 | goto out; | |
df4fc315 | 4289 | |
756d17ee | 4290 | ret = 0; |
df4fc315 | 4291 | |
756d17ee | 4292 | list_for_each_entry(fpid, &ftrace_pids, list) |
4293 | if (fpid->pid == pid) | |
4294 | goto out_put; | |
978f3a45 | 4295 | |
756d17ee | 4296 | ret = -ENOMEM; |
df4fc315 | 4297 | |
756d17ee | 4298 | fpid = kmalloc(sizeof(*fpid), GFP_KERNEL); |
4299 | if (!fpid) | |
4300 | goto out_put; | |
df4fc315 | 4301 | |
756d17ee | 4302 | list_add(&fpid->list, &ftrace_pids); |
4303 | fpid->pid = pid; | |
0ef8cde5 | 4304 | |
756d17ee | 4305 | set_ftrace_pid_task(pid); |
978f3a45 | 4306 | |
756d17ee | 4307 | ftrace_update_pid_func(); |
4308 | ftrace_startup_enable(0); | |
4309 | ||
4310 | mutex_unlock(&ftrace_lock); | |
4311 | return 0; | |
4312 | ||
4313 | out_put: | |
4314 | if (pid != ftrace_swapper_pid) | |
4315 | put_pid(pid); | |
978f3a45 | 4316 | |
756d17ee | 4317 | out: |
4318 | mutex_unlock(&ftrace_lock); | |
4319 | return ret; | |
4320 | } | |
4321 | ||
4322 | static void ftrace_pid_reset(void) | |
4323 | { | |
4324 | struct ftrace_pid *fpid, *safe; | |
978f3a45 | 4325 | |
756d17ee | 4326 | mutex_lock(&ftrace_lock); |
4327 | list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) { | |
4328 | struct pid *pid = fpid->pid; | |
4329 | ||
4330 | clear_ftrace_pid_task(pid); | |
4331 | ||
4332 | list_del(&fpid->list); | |
4333 | kfree(fpid); | |
df4fc315 SR |
4334 | } |
4335 | ||
df4fc315 SR |
4336 | ftrace_update_pid_func(); |
4337 | ftrace_startup_enable(0); | |
4338 | ||
e6ea44e9 | 4339 | mutex_unlock(&ftrace_lock); |
756d17ee | 4340 | } |
df4fc315 | 4341 | |
756d17ee | 4342 | static void *fpid_start(struct seq_file *m, loff_t *pos) |
4343 | { | |
4344 | mutex_lock(&ftrace_lock); | |
4345 | ||
4346 | if (list_empty(&ftrace_pids) && (!*pos)) | |
4347 | return (void *) 1; | |
4348 | ||
4349 | return seq_list_start(&ftrace_pids, *pos); | |
4350 | } | |
4351 | ||
4352 | static void *fpid_next(struct seq_file *m, void *v, loff_t *pos) | |
4353 | { | |
4354 | if (v == (void *)1) | |
4355 | return NULL; | |
4356 | ||
4357 | return seq_list_next(v, &ftrace_pids, pos); | |
4358 | } | |
4359 | ||
4360 | static void fpid_stop(struct seq_file *m, void *p) | |
4361 | { | |
4362 | mutex_unlock(&ftrace_lock); | |
4363 | } | |
4364 | ||
4365 | static int fpid_show(struct seq_file *m, void *v) | |
4366 | { | |
4367 | const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list); | |
4368 | ||
4369 | if (v == (void *)1) { | |
4370 | seq_printf(m, "no pid\n"); | |
4371 | return 0; | |
4372 | } | |
4373 | ||
4374 | if (fpid->pid == ftrace_swapper_pid) | |
4375 | seq_printf(m, "swapper tasks\n"); | |
4376 | else | |
4377 | seq_printf(m, "%u\n", pid_vnr(fpid->pid)); | |
4378 | ||
4379 | return 0; | |
4380 | } | |
4381 | ||
4382 | static const struct seq_operations ftrace_pid_sops = { | |
4383 | .start = fpid_start, | |
4384 | .next = fpid_next, | |
4385 | .stop = fpid_stop, | |
4386 | .show = fpid_show, | |
4387 | }; | |
4388 | ||
4389 | static int | |
4390 | ftrace_pid_open(struct inode *inode, struct file *file) | |
4391 | { | |
4392 | int ret = 0; | |
4393 | ||
4394 | if ((file->f_mode & FMODE_WRITE) && | |
4395 | (file->f_flags & O_TRUNC)) | |
4396 | ftrace_pid_reset(); | |
4397 | ||
4398 | if (file->f_mode & FMODE_READ) | |
4399 | ret = seq_open(file, &ftrace_pid_sops); | |
4400 | ||
4401 | return ret; | |
4402 | } | |
4403 | ||
df4fc315 SR |
4404 | static ssize_t |
4405 | ftrace_pid_write(struct file *filp, const char __user *ubuf, | |
4406 | size_t cnt, loff_t *ppos) | |
4407 | { | |
457dc928 | 4408 | char buf[64], *tmp; |
df4fc315 SR |
4409 | long val; |
4410 | int ret; | |
4411 | ||
4412 | if (cnt >= sizeof(buf)) | |
4413 | return -EINVAL; | |
4414 | ||
4415 | if (copy_from_user(&buf, ubuf, cnt)) | |
4416 | return -EFAULT; | |
4417 | ||
4418 | buf[cnt] = 0; | |
4419 | ||
756d17ee | 4420 | /* |
4421 | * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid" | |
4422 | * to clean the filter quietly. | |
4423 | */ | |
457dc928 IM |
4424 | tmp = strstrip(buf); |
4425 | if (strlen(tmp) == 0) | |
756d17ee | 4426 | return 1; |
4427 | ||
bcd83ea6 | 4428 | ret = kstrtol(tmp, 10, &val); |
df4fc315 SR |
4429 | if (ret < 0) |
4430 | return ret; | |
4431 | ||
756d17ee | 4432 | ret = ftrace_pid_add(val); |
df4fc315 | 4433 | |
756d17ee | 4434 | return ret ? ret : cnt; |
4435 | } | |
df4fc315 | 4436 | |
756d17ee | 4437 | static int |
4438 | ftrace_pid_release(struct inode *inode, struct file *file) | |
4439 | { | |
4440 | if (file->f_mode & FMODE_READ) | |
4441 | seq_release(inode, file); | |
df4fc315 | 4442 | |
756d17ee | 4443 | return 0; |
df4fc315 SR |
4444 | } |
4445 | ||
5e2336a0 | 4446 | static const struct file_operations ftrace_pid_fops = { |
756d17ee | 4447 | .open = ftrace_pid_open, |
4448 | .write = ftrace_pid_write, | |
4449 | .read = seq_read, | |
4450 | .llseek = seq_lseek, | |
4451 | .release = ftrace_pid_release, | |
df4fc315 SR |
4452 | }; |
4453 | ||
4454 | static __init int ftrace_init_debugfs(void) | |
4455 | { | |
4456 | struct dentry *d_tracer; | |
df4fc315 SR |
4457 | |
4458 | d_tracer = tracing_init_dentry(); | |
4459 | if (!d_tracer) | |
4460 | return 0; | |
4461 | ||
4462 | ftrace_init_dyn_debugfs(d_tracer); | |
4463 | ||
5452af66 FW |
4464 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
4465 | NULL, &ftrace_pid_fops); | |
493762fc SR |
4466 | |
4467 | ftrace_profile_debugfs(d_tracer); | |
4468 | ||
df4fc315 SR |
4469 | return 0; |
4470 | } | |
df4fc315 SR |
4471 | fs_initcall(ftrace_init_debugfs); |
4472 | ||
a2bb6a3d | 4473 | /** |
81adbdc0 | 4474 | * ftrace_kill - kill ftrace |
a2bb6a3d SR |
4475 | * |
4476 | * This function should be used by panic code. It stops ftrace | |
4477 | * but in a not so nice way. If you need to simply kill ftrace | |
4478 | * from a non-atomic section, use ftrace_kill. | |
4479 | */ | |
81adbdc0 | 4480 | void ftrace_kill(void) |
a2bb6a3d SR |
4481 | { |
4482 | ftrace_disabled = 1; | |
4483 | ftrace_enabled = 0; | |
a2bb6a3d SR |
4484 | clear_ftrace_function(); |
4485 | } | |
4486 | ||
e0a413f6 SR |
4487 | /** |
4488 | * Test if ftrace is dead or not. | |
4489 | */ | |
4490 | int ftrace_is_dead(void) | |
4491 | { | |
4492 | return ftrace_disabled; | |
4493 | } | |
4494 | ||
16444a8a | 4495 | /** |
3d083395 SR |
4496 | * register_ftrace_function - register a function for profiling |
4497 | * @ops - ops structure that holds the function for profiling. | |
16444a8a | 4498 | * |
3d083395 SR |
4499 | * Register a function to be called by all functions in the |
4500 | * kernel. | |
4501 | * | |
4502 | * Note: @ops->func and all the functions it calls must be labeled | |
4503 | * with "notrace", otherwise it will go into a | |
4504 | * recursive loop. | |
16444a8a | 4505 | */ |
3d083395 | 4506 | int register_ftrace_function(struct ftrace_ops *ops) |
16444a8a | 4507 | { |
45a4a237 | 4508 | int ret = -1; |
4eebcc81 | 4509 | |
e6ea44e9 | 4510 | mutex_lock(&ftrace_lock); |
e7d3737e | 4511 | |
b0fc494f | 4512 | ret = __register_ftrace_function(ops); |
b848914c | 4513 | if (!ret) |
a1cd6173 | 4514 | ret = ftrace_startup(ops, 0); |
b848914c | 4515 | |
e6ea44e9 | 4516 | mutex_unlock(&ftrace_lock); |
8d240dd8 | 4517 | |
b0fc494f | 4518 | return ret; |
3d083395 | 4519 | } |
cdbe61bf | 4520 | EXPORT_SYMBOL_GPL(register_ftrace_function); |
3d083395 SR |
4521 | |
4522 | /** | |
32632920 | 4523 | * unregister_ftrace_function - unregister a function for profiling. |
3d083395 SR |
4524 | * @ops - ops structure that holds the function to unregister |
4525 | * | |
4526 | * Unregister a function that was added to be called by ftrace profiling. | |
4527 | */ | |
4528 | int unregister_ftrace_function(struct ftrace_ops *ops) | |
4529 | { | |
4530 | int ret; | |
4531 | ||
e6ea44e9 | 4532 | mutex_lock(&ftrace_lock); |
3d083395 | 4533 | ret = __unregister_ftrace_function(ops); |
b848914c SR |
4534 | if (!ret) |
4535 | ftrace_shutdown(ops, 0); | |
e6ea44e9 | 4536 | mutex_unlock(&ftrace_lock); |
b0fc494f SR |
4537 | |
4538 | return ret; | |
4539 | } | |
cdbe61bf | 4540 | EXPORT_SYMBOL_GPL(unregister_ftrace_function); |
b0fc494f | 4541 | |
e309b41d | 4542 | int |
b0fc494f | 4543 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
8d65af78 | 4544 | void __user *buffer, size_t *lenp, |
b0fc494f SR |
4545 | loff_t *ppos) |
4546 | { | |
45a4a237 | 4547 | int ret = -ENODEV; |
4eebcc81 | 4548 | |
e6ea44e9 | 4549 | mutex_lock(&ftrace_lock); |
b0fc494f | 4550 | |
45a4a237 SR |
4551 | if (unlikely(ftrace_disabled)) |
4552 | goto out; | |
4553 | ||
4554 | ret = proc_dointvec(table, write, buffer, lenp, ppos); | |
b0fc494f | 4555 | |
a32c7765 | 4556 | if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) |
b0fc494f SR |
4557 | goto out; |
4558 | ||
a32c7765 | 4559 | last_ftrace_enabled = !!ftrace_enabled; |
b0fc494f SR |
4560 | |
4561 | if (ftrace_enabled) { | |
4562 | ||
4563 | ftrace_startup_sysctl(); | |
4564 | ||
4565 | /* we are starting ftrace again */ | |
b848914c SR |
4566 | if (ftrace_ops_list != &ftrace_list_end) { |
4567 | if (ftrace_ops_list->next == &ftrace_list_end) | |
4568 | ftrace_trace_function = ftrace_ops_list->func; | |
b0fc494f | 4569 | else |
b848914c | 4570 | ftrace_trace_function = ftrace_ops_list_func; |
b0fc494f SR |
4571 | } |
4572 | ||
4573 | } else { | |
4574 | /* stopping ftrace calls (just send to ftrace_stub) */ | |
4575 | ftrace_trace_function = ftrace_stub; | |
4576 | ||
4577 | ftrace_shutdown_sysctl(); | |
4578 | } | |
4579 | ||
4580 | out: | |
e6ea44e9 | 4581 | mutex_unlock(&ftrace_lock); |
3d083395 | 4582 | return ret; |
16444a8a | 4583 | } |
f17845e5 | 4584 | |
fb52607a | 4585 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
e7d3737e | 4586 | |
597af815 | 4587 | static int ftrace_graph_active; |
4a2b8dda | 4588 | static struct notifier_block ftrace_suspend_notifier; |
e7d3737e | 4589 | |
e49dc19c SR |
4590 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
4591 | { | |
4592 | return 0; | |
4593 | } | |
4594 | ||
287b6e68 FW |
4595 | /* The callbacks that hook a function */ |
4596 | trace_func_graph_ret_t ftrace_graph_return = | |
4597 | (trace_func_graph_ret_t)ftrace_stub; | |
e49dc19c | 4598 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
f201ae23 FW |
4599 | |
4600 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ | |
4601 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) | |
4602 | { | |
4603 | int i; | |
4604 | int ret = 0; | |
4605 | unsigned long flags; | |
4606 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; | |
4607 | struct task_struct *g, *t; | |
4608 | ||
4609 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { | |
4610 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH | |
4611 | * sizeof(struct ftrace_ret_stack), | |
4612 | GFP_KERNEL); | |
4613 | if (!ret_stack_list[i]) { | |
4614 | start = 0; | |
4615 | end = i; | |
4616 | ret = -ENOMEM; | |
4617 | goto free; | |
4618 | } | |
4619 | } | |
4620 | ||
4621 | read_lock_irqsave(&tasklist_lock, flags); | |
4622 | do_each_thread(g, t) { | |
4623 | if (start == end) { | |
4624 | ret = -EAGAIN; | |
4625 | goto unlock; | |
4626 | } | |
4627 | ||
4628 | if (t->ret_stack == NULL) { | |
380c4b14 | 4629 | atomic_set(&t->tracing_graph_pause, 0); |
f201ae23 | 4630 | atomic_set(&t->trace_overrun, 0); |
26c01624 SR |
4631 | t->curr_ret_stack = -1; |
4632 | /* Make sure the tasks see the -1 first: */ | |
4633 | smp_wmb(); | |
4634 | t->ret_stack = ret_stack_list[start++]; | |
f201ae23 FW |
4635 | } |
4636 | } while_each_thread(g, t); | |
4637 | ||
4638 | unlock: | |
4639 | read_unlock_irqrestore(&tasklist_lock, flags); | |
4640 | free: | |
4641 | for (i = start; i < end; i++) | |
4642 | kfree(ret_stack_list[i]); | |
4643 | return ret; | |
4644 | } | |
4645 | ||
8aef2d28 | 4646 | static void |
38516ab5 SR |
4647 | ftrace_graph_probe_sched_switch(void *ignore, |
4648 | struct task_struct *prev, struct task_struct *next) | |
8aef2d28 SR |
4649 | { |
4650 | unsigned long long timestamp; | |
4651 | int index; | |
4652 | ||
be6f164a SR |
4653 | /* |
4654 | * Does the user want to count the time a function was asleep. | |
4655 | * If so, do not update the time stamps. | |
4656 | */ | |
4657 | if (trace_flags & TRACE_ITER_SLEEP_TIME) | |
4658 | return; | |
4659 | ||
8aef2d28 SR |
4660 | timestamp = trace_clock_local(); |
4661 | ||
4662 | prev->ftrace_timestamp = timestamp; | |
4663 | ||
4664 | /* only process tasks that we timestamped */ | |
4665 | if (!next->ftrace_timestamp) | |
4666 | return; | |
4667 | ||
4668 | /* | |
4669 | * Update all the counters in next to make up for the | |
4670 | * time next was sleeping. | |
4671 | */ | |
4672 | timestamp -= next->ftrace_timestamp; | |
4673 | ||
4674 | for (index = next->curr_ret_stack; index >= 0; index--) | |
4675 | next->ret_stack[index].calltime += timestamp; | |
4676 | } | |
4677 | ||
f201ae23 | 4678 | /* Allocate a return stack for each task */ |
fb52607a | 4679 | static int start_graph_tracing(void) |
f201ae23 FW |
4680 | { |
4681 | struct ftrace_ret_stack **ret_stack_list; | |
5b058bcd | 4682 | int ret, cpu; |
f201ae23 FW |
4683 | |
4684 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * | |
4685 | sizeof(struct ftrace_ret_stack *), | |
4686 | GFP_KERNEL); | |
4687 | ||
4688 | if (!ret_stack_list) | |
4689 | return -ENOMEM; | |
4690 | ||
5b058bcd | 4691 | /* The cpu_boot init_task->ret_stack will never be freed */ |
179c498a SR |
4692 | for_each_online_cpu(cpu) { |
4693 | if (!idle_task(cpu)->ret_stack) | |
868baf07 | 4694 | ftrace_graph_init_idle_task(idle_task(cpu), cpu); |
179c498a | 4695 | } |
5b058bcd | 4696 | |
f201ae23 FW |
4697 | do { |
4698 | ret = alloc_retstack_tasklist(ret_stack_list); | |
4699 | } while (ret == -EAGAIN); | |
4700 | ||
8aef2d28 | 4701 | if (!ret) { |
38516ab5 | 4702 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
8aef2d28 SR |
4703 | if (ret) |
4704 | pr_info("ftrace_graph: Couldn't activate tracepoint" | |
4705 | " probe to kernel_sched_switch\n"); | |
4706 | } | |
4707 | ||
f201ae23 FW |
4708 | kfree(ret_stack_list); |
4709 | return ret; | |
4710 | } | |
4711 | ||
4a2b8dda FW |
4712 | /* |
4713 | * Hibernation protection. | |
4714 | * The state of the current task is too much unstable during | |
4715 | * suspend/restore to disk. We want to protect against that. | |
4716 | */ | |
4717 | static int | |
4718 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, | |
4719 | void *unused) | |
4720 | { | |
4721 | switch (state) { | |
4722 | case PM_HIBERNATION_PREPARE: | |
4723 | pause_graph_tracing(); | |
4724 | break; | |
4725 | ||
4726 | case PM_POST_HIBERNATION: | |
4727 | unpause_graph_tracing(); | |
4728 | break; | |
4729 | } | |
4730 | return NOTIFY_DONE; | |
4731 | } | |
4732 | ||
287b6e68 FW |
4733 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
4734 | trace_func_graph_ent_t entryfunc) | |
15e6cb36 | 4735 | { |
e7d3737e FW |
4736 | int ret = 0; |
4737 | ||
e6ea44e9 | 4738 | mutex_lock(&ftrace_lock); |
e7d3737e | 4739 | |
05ce5818 | 4740 | /* we currently allow only one tracer registered at a time */ |
597af815 | 4741 | if (ftrace_graph_active) { |
05ce5818 SR |
4742 | ret = -EBUSY; |
4743 | goto out; | |
4744 | } | |
4745 | ||
4a2b8dda FW |
4746 | ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; |
4747 | register_pm_notifier(&ftrace_suspend_notifier); | |
4748 | ||
597af815 | 4749 | ftrace_graph_active++; |
fb52607a | 4750 | ret = start_graph_tracing(); |
f201ae23 | 4751 | if (ret) { |
597af815 | 4752 | ftrace_graph_active--; |
f201ae23 FW |
4753 | goto out; |
4754 | } | |
e53a6319 | 4755 | |
287b6e68 FW |
4756 | ftrace_graph_return = retfunc; |
4757 | ftrace_graph_entry = entryfunc; | |
e53a6319 | 4758 | |
a1cd6173 | 4759 | ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET); |
e7d3737e FW |
4760 | |
4761 | out: | |
e6ea44e9 | 4762 | mutex_unlock(&ftrace_lock); |
e7d3737e | 4763 | return ret; |
15e6cb36 FW |
4764 | } |
4765 | ||
fb52607a | 4766 | void unregister_ftrace_graph(void) |
15e6cb36 | 4767 | { |
e6ea44e9 | 4768 | mutex_lock(&ftrace_lock); |
e7d3737e | 4769 | |
597af815 | 4770 | if (unlikely(!ftrace_graph_active)) |
2aad1b76 SR |
4771 | goto out; |
4772 | ||
597af815 | 4773 | ftrace_graph_active--; |
287b6e68 | 4774 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
e49dc19c | 4775 | ftrace_graph_entry = ftrace_graph_entry_stub; |
bd69c30b | 4776 | ftrace_shutdown(&global_ops, FTRACE_STOP_FUNC_RET); |
4a2b8dda | 4777 | unregister_pm_notifier(&ftrace_suspend_notifier); |
38516ab5 | 4778 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); |
e7d3737e | 4779 | |
2aad1b76 | 4780 | out: |
e6ea44e9 | 4781 | mutex_unlock(&ftrace_lock); |
15e6cb36 | 4782 | } |
f201ae23 | 4783 | |
868baf07 SR |
4784 | static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack); |
4785 | ||
4786 | static void | |
4787 | graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack) | |
4788 | { | |
4789 | atomic_set(&t->tracing_graph_pause, 0); | |
4790 | atomic_set(&t->trace_overrun, 0); | |
4791 | t->ftrace_timestamp = 0; | |
25985edc | 4792 | /* make curr_ret_stack visible before we add the ret_stack */ |
868baf07 SR |
4793 | smp_wmb(); |
4794 | t->ret_stack = ret_stack; | |
4795 | } | |
4796 | ||
4797 | /* | |
4798 | * Allocate a return stack for the idle task. May be the first | |
4799 | * time through, or it may be done by CPU hotplug online. | |
4800 | */ | |
4801 | void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) | |
4802 | { | |
4803 | t->curr_ret_stack = -1; | |
4804 | /* | |
4805 | * The idle task has no parent, it either has its own | |
4806 | * stack or no stack at all. | |
4807 | */ | |
4808 | if (t->ret_stack) | |
4809 | WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu)); | |
4810 | ||
4811 | if (ftrace_graph_active) { | |
4812 | struct ftrace_ret_stack *ret_stack; | |
4813 | ||
4814 | ret_stack = per_cpu(idle_ret_stack, cpu); | |
4815 | if (!ret_stack) { | |
4816 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
4817 | * sizeof(struct ftrace_ret_stack), | |
4818 | GFP_KERNEL); | |
4819 | if (!ret_stack) | |
4820 | return; | |
4821 | per_cpu(idle_ret_stack, cpu) = ret_stack; | |
4822 | } | |
4823 | graph_init_task(t, ret_stack); | |
4824 | } | |
4825 | } | |
4826 | ||
f201ae23 | 4827 | /* Allocate a return stack for newly created task */ |
fb52607a | 4828 | void ftrace_graph_init_task(struct task_struct *t) |
f201ae23 | 4829 | { |
84047e36 SR |
4830 | /* Make sure we do not use the parent ret_stack */ |
4831 | t->ret_stack = NULL; | |
ea14eb71 | 4832 | t->curr_ret_stack = -1; |
84047e36 | 4833 | |
597af815 | 4834 | if (ftrace_graph_active) { |
82310a32 SR |
4835 | struct ftrace_ret_stack *ret_stack; |
4836 | ||
4837 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH | |
f201ae23 FW |
4838 | * sizeof(struct ftrace_ret_stack), |
4839 | GFP_KERNEL); | |
82310a32 | 4840 | if (!ret_stack) |
f201ae23 | 4841 | return; |
868baf07 | 4842 | graph_init_task(t, ret_stack); |
84047e36 | 4843 | } |
f201ae23 FW |
4844 | } |
4845 | ||
fb52607a | 4846 | void ftrace_graph_exit_task(struct task_struct *t) |
f201ae23 | 4847 | { |
eae849ca FW |
4848 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
4849 | ||
f201ae23 | 4850 | t->ret_stack = NULL; |
eae849ca FW |
4851 | /* NULL must become visible to IRQs before we free it: */ |
4852 | barrier(); | |
4853 | ||
4854 | kfree(ret_stack); | |
f201ae23 | 4855 | } |
14a866c5 SR |
4856 | |
4857 | void ftrace_graph_stop(void) | |
4858 | { | |
4859 | ftrace_stop(); | |
4860 | } | |
15e6cb36 | 4861 | #endif |