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Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +02001/*
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
13 * Copyright (C) 2004 William Lee Irwin III
14 */
15
Steven Rostedt3d083392008-05-12 21:20:42 +020016#include <linux/stop_machine.h>
17#include <linux/clocksource.h>
18#include <linux/kallsyms.h>
Steven Rostedt5072c592008-05-12 21:20:43 +020019#include <linux/seq_file.h>
Frederic Weisbecker4a2b8dd2009-01-14 13:33:27 -080020#include <linux/suspend.h>
Steven Rostedt5072c592008-05-12 21:20:43 +020021#include <linux/debugfs.h>
Steven Rostedt3d083392008-05-12 21:20:42 +020022#include <linux/hardirq.h>
Ingo Molnar2d8b8202008-02-23 16:55:50 +010023#include <linux/kthread.h>
Steven Rostedt5072c592008-05-12 21:20:43 +020024#include <linux/uaccess.h>
Steven Rostedt5855fea2011-12-16 19:27:42 -050025#include <linux/bsearch.h>
Paul Gortmaker56d82e02011-05-26 17:53:52 -040026#include <linux/module.h>
Ingo Molnar2d8b8202008-02-23 16:55:50 +010027#include <linux/ftrace.h>
Steven Rostedtb0fc4942008-05-12 21:20:43 +020028#include <linux/sysctl.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090029#include <linux/slab.h>
Steven Rostedt5072c592008-05-12 21:20:43 +020030#include <linux/ctype.h>
Steven Rostedt68950612011-12-16 17:06:45 -050031#include <linux/sort.h>
Steven Rostedt3d083392008-05-12 21:20:42 +020032#include <linux/list.h>
Steven Rostedt59df055f2009-02-14 15:29:06 -050033#include <linux/hash.h>
Paul E. McKenney3f379b02010-03-05 15:03:25 -080034#include <linux/rcupdate.h>
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +020035
Steven Rostedtad8d75f2009-04-14 19:39:12 -040036#include <trace/events/sched.h>
Steven Rostedt8aef2d22009-03-24 01:10:15 -040037
Steven Rostedt2af15d62009-05-28 13:37:24 -040038#include <asm/setup.h>
Abhishek Sagar395a59d2008-06-21 23:47:27 +053039
Steven Rostedt0706f1c2009-03-23 23:12:58 -040040#include "trace_output.h"
Steven Rostedtbac429f2009-03-20 12:50:56 -040041#include "trace_stat.h"
Steven Rostedt3d083392008-05-12 21:20:42 +020042
Steven Rostedt69128962008-10-23 09:33:03 -040043#define FTRACE_WARN_ON(cond) \
Steven Rostedt0778d9a2011-04-29 10:36:31 -040044 ({ \
45 int ___r = cond; \
46 if (WARN_ON(___r)) \
Steven Rostedt69128962008-10-23 09:33:03 -040047 ftrace_kill(); \
Steven Rostedt0778d9a2011-04-29 10:36:31 -040048 ___r; \
49 })
Steven Rostedt69128962008-10-23 09:33:03 -040050
51#define FTRACE_WARN_ON_ONCE(cond) \
Steven Rostedt0778d9a2011-04-29 10:36:31 -040052 ({ \
53 int ___r = cond; \
54 if (WARN_ON_ONCE(___r)) \
Steven Rostedt69128962008-10-23 09:33:03 -040055 ftrace_kill(); \
Steven Rostedt0778d9a2011-04-29 10:36:31 -040056 ___r; \
57 })
Steven Rostedt69128962008-10-23 09:33:03 -040058
Steven Rostedt8fc0c702009-02-16 15:28:00 -050059/* hash bits for specific function selection */
60#define FTRACE_HASH_BITS 7
61#define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
Steven Rostedt33dc9b12011-05-02 17:34:47 -040062#define FTRACE_HASH_DEFAULT_BITS 10
63#define FTRACE_HASH_MAX_BITS 12
Steven Rostedt8fc0c702009-02-16 15:28:00 -050064
Jiri Olsae2484912012-02-15 15:51:48 +010065#define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_GLOBAL | FTRACE_OPS_FL_CONTROL)
66
Steven Rostedt4eebcc82008-05-12 21:20:48 +020067/* ftrace_enabled is a method to turn ftrace on or off */
68int ftrace_enabled __read_mostly;
Steven Rostedtd61f82d2008-05-12 21:20:43 +020069static int last_ftrace_enabled;
Steven Rostedtb0fc4942008-05-12 21:20:43 +020070
Steven Rostedt60a7ecf2008-11-05 16:05:44 -050071/* Quick disabling of function tracer. */
72int function_trace_stop;
73
jolsa@redhat.com756d17e2009-10-13 16:33:52 -040074/* List for set_ftrace_pid's pids. */
75LIST_HEAD(ftrace_pids);
76struct ftrace_pid {
77 struct list_head list;
78 struct pid *pid;
79};
80
Steven Rostedt4eebcc82008-05-12 21:20:48 +020081/*
82 * ftrace_disabled is set when an anomaly is discovered.
83 * ftrace_disabled is much stronger than ftrace_enabled.
84 */
85static int ftrace_disabled __read_mostly;
86
Steven Rostedt52baf112009-02-14 01:15:39 -050087static DEFINE_MUTEX(ftrace_lock);
Steven Rostedtb0fc4942008-05-12 21:20:43 +020088
Paul McQuadebd38c0e2011-05-31 20:51:55 +010089static struct ftrace_ops ftrace_list_end __read_mostly = {
Steven Rostedtfb9fb012009-03-25 13:26:41 -040090 .func = ftrace_stub,
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +020091};
92
Steven Rostedtb8489142011-05-04 09:27:52 -040093static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end;
Jiri Olsae2484912012-02-15 15:51:48 +010094static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end;
Steven Rostedtb8489142011-05-04 09:27:52 -040095static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end;
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +020096ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
Steven Rostedt6331c282011-07-13 15:11:02 -040097static ftrace_func_t __ftrace_trace_function_delay __read_mostly = ftrace_stub;
Steven Rostedt60a7ecf2008-11-05 16:05:44 -050098ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub;
Steven Rostedtdf4fc312008-11-26 00:16:23 -050099ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
Steven Rostedt2b499382011-05-03 22:49:52 -0400100static struct ftrace_ops global_ops;
Jiri Olsae2484912012-02-15 15:51:48 +0100101static struct ftrace_ops control_ops;
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200102
Steven Rostedtb8489142011-05-04 09:27:52 -0400103static void
104ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip);
105
Paul E. McKenney3f379b02010-03-05 15:03:25 -0800106/*
Steven Rostedtb8489142011-05-04 09:27:52 -0400107 * Traverse the ftrace_global_list, invoking all entries. The reason that we
Paul E. McKenney3f379b02010-03-05 15:03:25 -0800108 * can use rcu_dereference_raw() is that elements removed from this list
109 * are simply leaked, so there is no need to interact with a grace-period
110 * mechanism. The rcu_dereference_raw() calls are needed to handle
Steven Rostedtb8489142011-05-04 09:27:52 -0400111 * concurrent insertions into the ftrace_global_list.
Paul E. McKenney3f379b02010-03-05 15:03:25 -0800112 *
113 * Silly Alpha and silly pointer-speculation compiler optimizations!
114 */
Steven Rostedtb8489142011-05-04 09:27:52 -0400115static void ftrace_global_list_func(unsigned long ip,
116 unsigned long parent_ip)
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200117{
Steven Rostedtb1cff0a2011-05-25 14:27:43 -0400118 struct ftrace_ops *op;
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200119
Steven Rostedtb1cff0a2011-05-25 14:27:43 -0400120 if (unlikely(trace_recursion_test(TRACE_GLOBAL_BIT)))
121 return;
122
123 trace_recursion_set(TRACE_GLOBAL_BIT);
124 op = rcu_dereference_raw(ftrace_global_list); /*see above*/
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200125 while (op != &ftrace_list_end) {
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200126 op->func(ip, parent_ip);
Paul E. McKenney3f379b02010-03-05 15:03:25 -0800127 op = rcu_dereference_raw(op->next); /*see above*/
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200128 };
Steven Rostedtb1cff0a2011-05-25 14:27:43 -0400129 trace_recursion_clear(TRACE_GLOBAL_BIT);
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200130}
131
Steven Rostedtdf4fc312008-11-26 00:16:23 -0500132static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip)
133{
Steven Rostedt0ef8cde2008-12-03 15:36:58 -0500134 if (!test_tsk_trace_trace(current))
Steven Rostedtdf4fc312008-11-26 00:16:23 -0500135 return;
136
137 ftrace_pid_function(ip, parent_ip);
138}
139
140static void set_ftrace_pid_function(ftrace_func_t func)
141{
142 /* do not set ftrace_pid_function to itself! */
143 if (func != ftrace_pid_func)
144 ftrace_pid_function = func;
145}
146
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200147/**
Steven Rostedt3d083392008-05-12 21:20:42 +0200148 * clear_ftrace_function - reset the ftrace function
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200149 *
Steven Rostedt3d083392008-05-12 21:20:42 +0200150 * This NULLs the ftrace function and in essence stops
151 * tracing. There may be lag
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200152 */
Steven Rostedt3d083392008-05-12 21:20:42 +0200153void clear_ftrace_function(void)
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200154{
Steven Rostedt3d083392008-05-12 21:20:42 +0200155 ftrace_trace_function = ftrace_stub;
Steven Rostedt60a7ecf2008-11-05 16:05:44 -0500156 __ftrace_trace_function = ftrace_stub;
Steven Rostedt6331c282011-07-13 15:11:02 -0400157 __ftrace_trace_function_delay = ftrace_stub;
Steven Rostedtdf4fc312008-11-26 00:16:23 -0500158 ftrace_pid_function = ftrace_stub;
Steven Rostedt3d083392008-05-12 21:20:42 +0200159}
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200160
Steven Rostedt60a7ecf2008-11-05 16:05:44 -0500161#ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
162/*
163 * For those archs that do not test ftrace_trace_stop in their
164 * mcount call site, we need to do it from C.
165 */
166static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip)
167{
168 if (function_trace_stop)
169 return;
170
171 __ftrace_trace_function(ip, parent_ip);
172}
173#endif
174
Jiri Olsae2484912012-02-15 15:51:48 +0100175static void control_ops_disable_all(struct ftrace_ops *ops)
176{
177 int cpu;
178
179 for_each_possible_cpu(cpu)
180 *per_cpu_ptr(ops->disabled, cpu) = 1;
181}
182
183static int control_ops_alloc(struct ftrace_ops *ops)
184{
185 int __percpu *disabled;
186
187 disabled = alloc_percpu(int);
188 if (!disabled)
189 return -ENOMEM;
190
191 ops->disabled = disabled;
192 control_ops_disable_all(ops);
193 return 0;
194}
195
196static void control_ops_free(struct ftrace_ops *ops)
197{
198 free_percpu(ops->disabled);
199}
200
Steven Rostedt2b499382011-05-03 22:49:52 -0400201static void update_global_ops(void)
Steven Rostedt491d0dc2011-04-27 21:43:36 -0400202{
203 ftrace_func_t func;
204
205 /*
206 * If there's only one function registered, then call that
207 * function directly. Otherwise, we need to iterate over the
208 * registered callers.
209 */
Steven Rostedtb8489142011-05-04 09:27:52 -0400210 if (ftrace_global_list == &ftrace_list_end ||
211 ftrace_global_list->next == &ftrace_list_end)
212 func = ftrace_global_list->func;
Steven Rostedt491d0dc2011-04-27 21:43:36 -0400213 else
Steven Rostedtb8489142011-05-04 09:27:52 -0400214 func = ftrace_global_list_func;
Steven Rostedt491d0dc2011-04-27 21:43:36 -0400215
216 /* If we filter on pids, update to use the pid function */
217 if (!list_empty(&ftrace_pids)) {
218 set_ftrace_pid_function(func);
219 func = ftrace_pid_func;
220 }
Steven Rostedt2b499382011-05-03 22:49:52 -0400221
222 global_ops.func = func;
223}
224
225static void update_ftrace_function(void)
226{
227 ftrace_func_t func;
228
229 update_global_ops();
230
Steven Rostedtcdbe61b2011-05-05 21:14:55 -0400231 /*
232 * If we are at the end of the list and this ops is
233 * not dynamic, then have the mcount trampoline call
234 * the function directly
235 */
Steven Rostedtb8489142011-05-04 09:27:52 -0400236 if (ftrace_ops_list == &ftrace_list_end ||
Steven Rostedtcdbe61b2011-05-05 21:14:55 -0400237 (ftrace_ops_list->next == &ftrace_list_end &&
238 !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC)))
Steven Rostedtb8489142011-05-04 09:27:52 -0400239 func = ftrace_ops_list->func;
240 else
241 func = ftrace_ops_list_func;
Steven Rostedt2b499382011-05-03 22:49:52 -0400242
Steven Rostedt491d0dc2011-04-27 21:43:36 -0400243#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
244 ftrace_trace_function = func;
245#else
Steven Rostedt6331c282011-07-13 15:11:02 -0400246#ifdef CONFIG_DYNAMIC_FTRACE
247 /* do not update till all functions have been modified */
248 __ftrace_trace_function_delay = func;
249#else
Steven Rostedt491d0dc2011-04-27 21:43:36 -0400250 __ftrace_trace_function = func;
Steven Rostedt6331c282011-07-13 15:11:02 -0400251#endif
Rajesh Bhagatdb6544e2012-02-17 13:59:15 +0530252 ftrace_trace_function =
253 (func == ftrace_stub) ? func : ftrace_test_stop_func;
Steven Rostedt491d0dc2011-04-27 21:43:36 -0400254#endif
255}
256
Steven Rostedt2b499382011-05-03 22:49:52 -0400257static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
Steven Rostedt3d083392008-05-12 21:20:42 +0200258{
Steven Rostedt2b499382011-05-03 22:49:52 -0400259 ops->next = *list;
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200260 /*
Steven Rostedtb8489142011-05-04 09:27:52 -0400261 * We are entering ops into the list but another
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200262 * CPU might be walking that list. We need to make sure
263 * the ops->next pointer is valid before another CPU sees
Steven Rostedtb8489142011-05-04 09:27:52 -0400264 * the ops pointer included into the list.
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200265 */
Steven Rostedt2b499382011-05-03 22:49:52 -0400266 rcu_assign_pointer(*list, ops);
267}
Steven Rostedt3d083392008-05-12 21:20:42 +0200268
Steven Rostedt2b499382011-05-03 22:49:52 -0400269static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
270{
271 struct ftrace_ops **p;
272
273 /*
274 * If we are removing the last function, then simply point
275 * to the ftrace_stub.
276 */
277 if (*list == ops && ops->next == &ftrace_list_end) {
278 *list = &ftrace_list_end;
279 return 0;
280 }
281
282 for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
283 if (*p == ops)
284 break;
285
286 if (*p != ops)
287 return -1;
288
289 *p = (*p)->next;
290 return 0;
291}
292
Jiri Olsae2484912012-02-15 15:51:48 +0100293static void add_ftrace_list_ops(struct ftrace_ops **list,
294 struct ftrace_ops *main_ops,
295 struct ftrace_ops *ops)
296{
297 int first = *list == &ftrace_list_end;
298 add_ftrace_ops(list, ops);
299 if (first)
300 add_ftrace_ops(&ftrace_ops_list, main_ops);
301}
302
303static int remove_ftrace_list_ops(struct ftrace_ops **list,
304 struct ftrace_ops *main_ops,
305 struct ftrace_ops *ops)
306{
307 int ret = remove_ftrace_ops(list, ops);
308 if (!ret && *list == &ftrace_list_end)
309 ret = remove_ftrace_ops(&ftrace_ops_list, main_ops);
310 return ret;
311}
312
Steven Rostedt2b499382011-05-03 22:49:52 -0400313static int __register_ftrace_function(struct ftrace_ops *ops)
314{
315 if (ftrace_disabled)
316 return -ENODEV;
317
318 if (FTRACE_WARN_ON(ops == &global_ops))
319 return -EINVAL;
320
Steven Rostedtb8489142011-05-04 09:27:52 -0400321 if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
322 return -EBUSY;
323
Jiri Olsae2484912012-02-15 15:51:48 +0100324 /* We don't support both control and global flags set. */
325 if ((ops->flags & FL_GLOBAL_CONTROL_MASK) == FL_GLOBAL_CONTROL_MASK)
326 return -EINVAL;
327
Steven Rostedtcdbe61b2011-05-05 21:14:55 -0400328 if (!core_kernel_data((unsigned long)ops))
329 ops->flags |= FTRACE_OPS_FL_DYNAMIC;
330
Steven Rostedtb8489142011-05-04 09:27:52 -0400331 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
Jiri Olsae2484912012-02-15 15:51:48 +0100332 add_ftrace_list_ops(&ftrace_global_list, &global_ops, ops);
Steven Rostedtb8489142011-05-04 09:27:52 -0400333 ops->flags |= FTRACE_OPS_FL_ENABLED;
Jiri Olsae2484912012-02-15 15:51:48 +0100334 } else if (ops->flags & FTRACE_OPS_FL_CONTROL) {
335 if (control_ops_alloc(ops))
336 return -ENOMEM;
337 add_ftrace_list_ops(&ftrace_control_list, &control_ops, ops);
Steven Rostedtb8489142011-05-04 09:27:52 -0400338 } else
339 add_ftrace_ops(&ftrace_ops_list, ops);
340
Steven Rostedt491d0dc2011-04-27 21:43:36 -0400341 if (ftrace_enabled)
342 update_ftrace_function();
Steven Rostedt3d083392008-05-12 21:20:42 +0200343
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200344 return 0;
345}
346
Ingo Molnare309b412008-05-12 21:20:51 +0200347static int __unregister_ftrace_function(struct ftrace_ops *ops)
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200348{
Steven Rostedt2b499382011-05-03 22:49:52 -0400349 int ret;
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200350
Steven Rostedt2b499382011-05-03 22:49:52 -0400351 if (ftrace_disabled)
352 return -ENODEV;
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200353
Steven Rostedtb8489142011-05-04 09:27:52 -0400354 if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
355 return -EBUSY;
356
Steven Rostedt2b499382011-05-03 22:49:52 -0400357 if (FTRACE_WARN_ON(ops == &global_ops))
358 return -EINVAL;
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200359
Steven Rostedtb8489142011-05-04 09:27:52 -0400360 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
Jiri Olsae2484912012-02-15 15:51:48 +0100361 ret = remove_ftrace_list_ops(&ftrace_global_list,
362 &global_ops, ops);
Steven Rostedtb8489142011-05-04 09:27:52 -0400363 if (!ret)
364 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
Jiri Olsae2484912012-02-15 15:51:48 +0100365 } else if (ops->flags & FTRACE_OPS_FL_CONTROL) {
366 ret = remove_ftrace_list_ops(&ftrace_control_list,
367 &control_ops, ops);
368 if (!ret) {
369 /*
370 * The ftrace_ops is now removed from the list,
371 * so there'll be no new users. We must ensure
372 * all current users are done before we free
373 * the control data.
374 */
375 synchronize_sched();
376 control_ops_free(ops);
377 }
Steven Rostedtb8489142011-05-04 09:27:52 -0400378 } else
379 ret = remove_ftrace_ops(&ftrace_ops_list, ops);
380
Steven Rostedt2b499382011-05-03 22:49:52 -0400381 if (ret < 0)
382 return ret;
Steven Rostedtb8489142011-05-04 09:27:52 -0400383
Steven Rostedt491d0dc2011-04-27 21:43:36 -0400384 if (ftrace_enabled)
385 update_ftrace_function();
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200386
Steven Rostedtcdbe61b2011-05-05 21:14:55 -0400387 /*
388 * Dynamic ops may be freed, we must make sure that all
389 * callers are done before leaving this function.
390 */
391 if (ops->flags & FTRACE_OPS_FL_DYNAMIC)
392 synchronize_sched();
393
Steven Rostedte6ea44e2009-02-14 01:42:44 -0500394 return 0;
Steven Rostedt3d083392008-05-12 21:20:42 +0200395}
396
Steven Rostedtdf4fc312008-11-26 00:16:23 -0500397static void ftrace_update_pid_func(void)
398{
Steven Rostedt491d0dc2011-04-27 21:43:36 -0400399 /* Only do something if we are tracing something */
Steven Rostedtdf4fc312008-11-26 00:16:23 -0500400 if (ftrace_trace_function == ftrace_stub)
KOSAKI Motohiro10dd3eb2009-03-06 15:29:04 +0900401 return;
Steven Rostedtdf4fc312008-11-26 00:16:23 -0500402
Steven Rostedt491d0dc2011-04-27 21:43:36 -0400403 update_ftrace_function();
Steven Rostedtdf4fc312008-11-26 00:16:23 -0500404}
405
Steven Rostedt493762f2009-03-23 17:12:36 -0400406#ifdef CONFIG_FUNCTION_PROFILER
407struct ftrace_profile {
408 struct hlist_node node;
409 unsigned long ip;
410 unsigned long counter;
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400411#ifdef CONFIG_FUNCTION_GRAPH_TRACER
412 unsigned long long time;
Chase Douglase330b3b2010-04-26 14:02:05 -0400413 unsigned long long time_squared;
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400414#endif
Steven Rostedt493762f2009-03-23 17:12:36 -0400415};
416
417struct ftrace_profile_page {
418 struct ftrace_profile_page *next;
419 unsigned long index;
420 struct ftrace_profile records[];
421};
422
Steven Rostedtcafb1682009-03-24 20:50:39 -0400423struct ftrace_profile_stat {
424 atomic_t disabled;
425 struct hlist_head *hash;
426 struct ftrace_profile_page *pages;
427 struct ftrace_profile_page *start;
428 struct tracer_stat stat;
429};
430
Steven Rostedt493762f2009-03-23 17:12:36 -0400431#define PROFILE_RECORDS_SIZE \
432 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
433
434#define PROFILES_PER_PAGE \
435 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
436
Steven Rostedtfb9fb012009-03-25 13:26:41 -0400437static int ftrace_profile_bits __read_mostly;
438static int ftrace_profile_enabled __read_mostly;
439
440/* ftrace_profile_lock - synchronize the enable and disable of the profiler */
Steven Rostedt493762f2009-03-23 17:12:36 -0400441static DEFINE_MUTEX(ftrace_profile_lock);
442
Steven Rostedtcafb1682009-03-24 20:50:39 -0400443static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
Steven Rostedt493762f2009-03-23 17:12:36 -0400444
445#define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */
446
Steven Rostedt493762f2009-03-23 17:12:36 -0400447static void *
448function_stat_next(void *v, int idx)
449{
450 struct ftrace_profile *rec = v;
451 struct ftrace_profile_page *pg;
452
453 pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
454
455 again:
Li Zefan0296e422009-06-26 11:15:37 +0800456 if (idx != 0)
457 rec++;
458
Steven Rostedt493762f2009-03-23 17:12:36 -0400459 if ((void *)rec >= (void *)&pg->records[pg->index]) {
460 pg = pg->next;
461 if (!pg)
462 return NULL;
463 rec = &pg->records[0];
464 if (!rec->counter)
465 goto again;
466 }
467
468 return rec;
469}
470
471static void *function_stat_start(struct tracer_stat *trace)
472{
Steven Rostedtcafb1682009-03-24 20:50:39 -0400473 struct ftrace_profile_stat *stat =
474 container_of(trace, struct ftrace_profile_stat, stat);
475
476 if (!stat || !stat->start)
477 return NULL;
478
479 return function_stat_next(&stat->start->records[0], 0);
Steven Rostedt493762f2009-03-23 17:12:36 -0400480}
481
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400482#ifdef CONFIG_FUNCTION_GRAPH_TRACER
483/* function graph compares on total time */
484static int function_stat_cmp(void *p1, void *p2)
485{
486 struct ftrace_profile *a = p1;
487 struct ftrace_profile *b = p2;
488
489 if (a->time < b->time)
490 return -1;
491 if (a->time > b->time)
492 return 1;
493 else
494 return 0;
495}
496#else
497/* not function graph compares against hits */
Steven Rostedt493762f2009-03-23 17:12:36 -0400498static int function_stat_cmp(void *p1, void *p2)
499{
500 struct ftrace_profile *a = p1;
501 struct ftrace_profile *b = p2;
502
503 if (a->counter < b->counter)
504 return -1;
505 if (a->counter > b->counter)
506 return 1;
507 else
508 return 0;
509}
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400510#endif
Steven Rostedt493762f2009-03-23 17:12:36 -0400511
512static int function_stat_headers(struct seq_file *m)
513{
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400514#ifdef CONFIG_FUNCTION_GRAPH_TRACER
Steven Rostedt34886c82009-03-25 21:00:47 -0400515 seq_printf(m, " Function "
Chase Douglase330b3b2010-04-26 14:02:05 -0400516 "Hit Time Avg s^2\n"
Steven Rostedt34886c82009-03-25 21:00:47 -0400517 " -------- "
Chase Douglase330b3b2010-04-26 14:02:05 -0400518 "--- ---- --- ---\n");
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400519#else
Steven Rostedt493762f2009-03-23 17:12:36 -0400520 seq_printf(m, " Function Hit\n"
521 " -------- ---\n");
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400522#endif
Steven Rostedt493762f2009-03-23 17:12:36 -0400523 return 0;
524}
525
526static int function_stat_show(struct seq_file *m, void *v)
527{
528 struct ftrace_profile *rec = v;
529 char str[KSYM_SYMBOL_LEN];
Li Zefan3aaba202010-08-23 16:50:12 +0800530 int ret = 0;
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400531#ifdef CONFIG_FUNCTION_GRAPH_TRACER
Steven Rostedt34886c82009-03-25 21:00:47 -0400532 static struct trace_seq s;
533 unsigned long long avg;
Chase Douglase330b3b2010-04-26 14:02:05 -0400534 unsigned long long stddev;
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400535#endif
Li Zefan3aaba202010-08-23 16:50:12 +0800536 mutex_lock(&ftrace_profile_lock);
537
538 /* we raced with function_profile_reset() */
539 if (unlikely(rec->counter == 0)) {
540 ret = -EBUSY;
541 goto out;
542 }
Steven Rostedt493762f2009-03-23 17:12:36 -0400543
544 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400545 seq_printf(m, " %-30.30s %10lu", str, rec->counter);
Steven Rostedt493762f2009-03-23 17:12:36 -0400546
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400547#ifdef CONFIG_FUNCTION_GRAPH_TRACER
548 seq_printf(m, " ");
Steven Rostedt34886c82009-03-25 21:00:47 -0400549 avg = rec->time;
550 do_div(avg, rec->counter);
551
Chase Douglase330b3b2010-04-26 14:02:05 -0400552 /* Sample standard deviation (s^2) */
553 if (rec->counter <= 1)
554 stddev = 0;
555 else {
556 stddev = rec->time_squared - rec->counter * avg * avg;
557 /*
558 * Divide only 1000 for ns^2 -> us^2 conversion.
559 * trace_print_graph_duration will divide 1000 again.
560 */
561 do_div(stddev, (rec->counter - 1) * 1000);
562 }
563
Steven Rostedt34886c82009-03-25 21:00:47 -0400564 trace_seq_init(&s);
565 trace_print_graph_duration(rec->time, &s);
566 trace_seq_puts(&s, " ");
567 trace_print_graph_duration(avg, &s);
Chase Douglase330b3b2010-04-26 14:02:05 -0400568 trace_seq_puts(&s, " ");
569 trace_print_graph_duration(stddev, &s);
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400570 trace_print_seq(m, &s);
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400571#endif
572 seq_putc(m, '\n');
Li Zefan3aaba202010-08-23 16:50:12 +0800573out:
574 mutex_unlock(&ftrace_profile_lock);
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400575
Li Zefan3aaba202010-08-23 16:50:12 +0800576 return ret;
Steven Rostedt493762f2009-03-23 17:12:36 -0400577}
578
Steven Rostedtcafb1682009-03-24 20:50:39 -0400579static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
Steven Rostedt493762f2009-03-23 17:12:36 -0400580{
581 struct ftrace_profile_page *pg;
582
Steven Rostedtcafb1682009-03-24 20:50:39 -0400583 pg = stat->pages = stat->start;
Steven Rostedt493762f2009-03-23 17:12:36 -0400584
585 while (pg) {
586 memset(pg->records, 0, PROFILE_RECORDS_SIZE);
587 pg->index = 0;
588 pg = pg->next;
589 }
590
Steven Rostedtcafb1682009-03-24 20:50:39 -0400591 memset(stat->hash, 0,
Steven Rostedt493762f2009-03-23 17:12:36 -0400592 FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
593}
594
Steven Rostedtcafb1682009-03-24 20:50:39 -0400595int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
Steven Rostedt493762f2009-03-23 17:12:36 -0400596{
597 struct ftrace_profile_page *pg;
Steven Rostedt318e0a72009-03-25 20:06:34 -0400598 int functions;
599 int pages;
Steven Rostedt493762f2009-03-23 17:12:36 -0400600 int i;
601
602 /* If we already allocated, do nothing */
Steven Rostedtcafb1682009-03-24 20:50:39 -0400603 if (stat->pages)
Steven Rostedt493762f2009-03-23 17:12:36 -0400604 return 0;
605
Steven Rostedtcafb1682009-03-24 20:50:39 -0400606 stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
607 if (!stat->pages)
Steven Rostedt493762f2009-03-23 17:12:36 -0400608 return -ENOMEM;
609
Steven Rostedt318e0a72009-03-25 20:06:34 -0400610#ifdef CONFIG_DYNAMIC_FTRACE
611 functions = ftrace_update_tot_cnt;
612#else
613 /*
614 * We do not know the number of functions that exist because
615 * dynamic tracing is what counts them. With past experience
616 * we have around 20K functions. That should be more than enough.
617 * It is highly unlikely we will execute every function in
618 * the kernel.
619 */
620 functions = 20000;
621#endif
622
Steven Rostedtcafb1682009-03-24 20:50:39 -0400623 pg = stat->start = stat->pages;
Steven Rostedt493762f2009-03-23 17:12:36 -0400624
Steven Rostedt318e0a72009-03-25 20:06:34 -0400625 pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
626
627 for (i = 0; i < pages; i++) {
Steven Rostedt493762f2009-03-23 17:12:36 -0400628 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
Steven Rostedt493762f2009-03-23 17:12:36 -0400629 if (!pg->next)
Steven Rostedt318e0a72009-03-25 20:06:34 -0400630 goto out_free;
Steven Rostedt493762f2009-03-23 17:12:36 -0400631 pg = pg->next;
632 }
633
634 return 0;
Steven Rostedt318e0a72009-03-25 20:06:34 -0400635
636 out_free:
637 pg = stat->start;
638 while (pg) {
639 unsigned long tmp = (unsigned long)pg;
640
641 pg = pg->next;
642 free_page(tmp);
643 }
644
645 free_page((unsigned long)stat->pages);
646 stat->pages = NULL;
647 stat->start = NULL;
648
649 return -ENOMEM;
Steven Rostedt493762f2009-03-23 17:12:36 -0400650}
651
Steven Rostedtcafb1682009-03-24 20:50:39 -0400652static int ftrace_profile_init_cpu(int cpu)
Steven Rostedt493762f2009-03-23 17:12:36 -0400653{
Steven Rostedtcafb1682009-03-24 20:50:39 -0400654 struct ftrace_profile_stat *stat;
Steven Rostedt493762f2009-03-23 17:12:36 -0400655 int size;
656
Steven Rostedtcafb1682009-03-24 20:50:39 -0400657 stat = &per_cpu(ftrace_profile_stats, cpu);
658
659 if (stat->hash) {
Steven Rostedt493762f2009-03-23 17:12:36 -0400660 /* If the profile is already created, simply reset it */
Steven Rostedtcafb1682009-03-24 20:50:39 -0400661 ftrace_profile_reset(stat);
Steven Rostedt493762f2009-03-23 17:12:36 -0400662 return 0;
663 }
664
665 /*
666 * We are profiling all functions, but usually only a few thousand
667 * functions are hit. We'll make a hash of 1024 items.
668 */
669 size = FTRACE_PROFILE_HASH_SIZE;
670
Steven Rostedtcafb1682009-03-24 20:50:39 -0400671 stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL);
Steven Rostedt493762f2009-03-23 17:12:36 -0400672
Steven Rostedtcafb1682009-03-24 20:50:39 -0400673 if (!stat->hash)
Steven Rostedt493762f2009-03-23 17:12:36 -0400674 return -ENOMEM;
675
Steven Rostedtcafb1682009-03-24 20:50:39 -0400676 if (!ftrace_profile_bits) {
677 size--;
Steven Rostedt493762f2009-03-23 17:12:36 -0400678
Steven Rostedtcafb1682009-03-24 20:50:39 -0400679 for (; size; size >>= 1)
680 ftrace_profile_bits++;
681 }
Steven Rostedt493762f2009-03-23 17:12:36 -0400682
Steven Rostedt318e0a72009-03-25 20:06:34 -0400683 /* Preallocate the function profiling pages */
Steven Rostedtcafb1682009-03-24 20:50:39 -0400684 if (ftrace_profile_pages_init(stat) < 0) {
685 kfree(stat->hash);
686 stat->hash = NULL;
Steven Rostedt493762f2009-03-23 17:12:36 -0400687 return -ENOMEM;
688 }
689
690 return 0;
691}
692
Steven Rostedtcafb1682009-03-24 20:50:39 -0400693static int ftrace_profile_init(void)
694{
695 int cpu;
696 int ret = 0;
697
698 for_each_online_cpu(cpu) {
699 ret = ftrace_profile_init_cpu(cpu);
700 if (ret)
701 break;
702 }
703
704 return ret;
705}
706
Steven Rostedt493762f2009-03-23 17:12:36 -0400707/* interrupts must be disabled */
Steven Rostedtcafb1682009-03-24 20:50:39 -0400708static struct ftrace_profile *
709ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
Steven Rostedt493762f2009-03-23 17:12:36 -0400710{
711 struct ftrace_profile *rec;
712 struct hlist_head *hhd;
713 struct hlist_node *n;
714 unsigned long key;
715
716 key = hash_long(ip, ftrace_profile_bits);
Steven Rostedtcafb1682009-03-24 20:50:39 -0400717 hhd = &stat->hash[key];
Steven Rostedt493762f2009-03-23 17:12:36 -0400718
719 if (hlist_empty(hhd))
720 return NULL;
721
722 hlist_for_each_entry_rcu(rec, n, hhd, node) {
723 if (rec->ip == ip)
724 return rec;
725 }
726
727 return NULL;
728}
729
Steven Rostedtcafb1682009-03-24 20:50:39 -0400730static void ftrace_add_profile(struct ftrace_profile_stat *stat,
731 struct ftrace_profile *rec)
Steven Rostedt493762f2009-03-23 17:12:36 -0400732{
733 unsigned long key;
734
735 key = hash_long(rec->ip, ftrace_profile_bits);
Steven Rostedtcafb1682009-03-24 20:50:39 -0400736 hlist_add_head_rcu(&rec->node, &stat->hash[key]);
Steven Rostedt493762f2009-03-23 17:12:36 -0400737}
738
Steven Rostedt318e0a72009-03-25 20:06:34 -0400739/*
740 * The memory is already allocated, this simply finds a new record to use.
741 */
Steven Rostedt493762f2009-03-23 17:12:36 -0400742static struct ftrace_profile *
Steven Rostedt318e0a72009-03-25 20:06:34 -0400743ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
Steven Rostedt493762f2009-03-23 17:12:36 -0400744{
745 struct ftrace_profile *rec = NULL;
746
Steven Rostedt318e0a72009-03-25 20:06:34 -0400747 /* prevent recursion (from NMIs) */
Steven Rostedtcafb1682009-03-24 20:50:39 -0400748 if (atomic_inc_return(&stat->disabled) != 1)
Steven Rostedt493762f2009-03-23 17:12:36 -0400749 goto out;
750
Steven Rostedt493762f2009-03-23 17:12:36 -0400751 /*
Steven Rostedt318e0a72009-03-25 20:06:34 -0400752 * Try to find the function again since an NMI
753 * could have added it
Steven Rostedt493762f2009-03-23 17:12:36 -0400754 */
Steven Rostedtcafb1682009-03-24 20:50:39 -0400755 rec = ftrace_find_profiled_func(stat, ip);
Steven Rostedt493762f2009-03-23 17:12:36 -0400756 if (rec)
Steven Rostedtcafb1682009-03-24 20:50:39 -0400757 goto out;
Steven Rostedt493762f2009-03-23 17:12:36 -0400758
Steven Rostedtcafb1682009-03-24 20:50:39 -0400759 if (stat->pages->index == PROFILES_PER_PAGE) {
760 if (!stat->pages->next)
761 goto out;
762 stat->pages = stat->pages->next;
Steven Rostedt493762f2009-03-23 17:12:36 -0400763 }
764
Steven Rostedtcafb1682009-03-24 20:50:39 -0400765 rec = &stat->pages->records[stat->pages->index++];
Steven Rostedt493762f2009-03-23 17:12:36 -0400766 rec->ip = ip;
Steven Rostedtcafb1682009-03-24 20:50:39 -0400767 ftrace_add_profile(stat, rec);
Steven Rostedt493762f2009-03-23 17:12:36 -0400768
Steven Rostedt493762f2009-03-23 17:12:36 -0400769 out:
Steven Rostedtcafb1682009-03-24 20:50:39 -0400770 atomic_dec(&stat->disabled);
Steven Rostedt493762f2009-03-23 17:12:36 -0400771
772 return rec;
773}
774
Steven Rostedt493762f2009-03-23 17:12:36 -0400775static void
776function_profile_call(unsigned long ip, unsigned long parent_ip)
777{
Steven Rostedtcafb1682009-03-24 20:50:39 -0400778 struct ftrace_profile_stat *stat;
Steven Rostedt493762f2009-03-23 17:12:36 -0400779 struct ftrace_profile *rec;
780 unsigned long flags;
Steven Rostedt493762f2009-03-23 17:12:36 -0400781
782 if (!ftrace_profile_enabled)
783 return;
784
Steven Rostedt493762f2009-03-23 17:12:36 -0400785 local_irq_save(flags);
Steven Rostedtcafb1682009-03-24 20:50:39 -0400786
787 stat = &__get_cpu_var(ftrace_profile_stats);
Steven Rostedt0f6ce3d2009-06-01 21:51:28 -0400788 if (!stat->hash || !ftrace_profile_enabled)
Steven Rostedtcafb1682009-03-24 20:50:39 -0400789 goto out;
790
791 rec = ftrace_find_profiled_func(stat, ip);
Steven Rostedt493762f2009-03-23 17:12:36 -0400792 if (!rec) {
Steven Rostedt318e0a72009-03-25 20:06:34 -0400793 rec = ftrace_profile_alloc(stat, ip);
Steven Rostedt493762f2009-03-23 17:12:36 -0400794 if (!rec)
795 goto out;
796 }
797
798 rec->counter++;
799 out:
800 local_irq_restore(flags);
801}
802
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400803#ifdef CONFIG_FUNCTION_GRAPH_TRACER
804static int profile_graph_entry(struct ftrace_graph_ent *trace)
805{
806 function_profile_call(trace->func, 0);
807 return 1;
808}
809
810static void profile_graph_return(struct ftrace_graph_ret *trace)
811{
Steven Rostedtcafb1682009-03-24 20:50:39 -0400812 struct ftrace_profile_stat *stat;
Steven Rostedta2a16d62009-03-24 23:17:58 -0400813 unsigned long long calltime;
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400814 struct ftrace_profile *rec;
Steven Rostedtcafb1682009-03-24 20:50:39 -0400815 unsigned long flags;
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400816
817 local_irq_save(flags);
Steven Rostedtcafb1682009-03-24 20:50:39 -0400818 stat = &__get_cpu_var(ftrace_profile_stats);
Steven Rostedt0f6ce3d2009-06-01 21:51:28 -0400819 if (!stat->hash || !ftrace_profile_enabled)
Steven Rostedtcafb1682009-03-24 20:50:39 -0400820 goto out;
821
Steven Rostedt37e44bc2010-04-27 21:04:24 -0400822 /* If the calltime was zero'd ignore it */
823 if (!trace->calltime)
824 goto out;
825
Steven Rostedta2a16d62009-03-24 23:17:58 -0400826 calltime = trace->rettime - trace->calltime;
827
828 if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) {
829 int index;
830
831 index = trace->depth;
832
833 /* Append this call time to the parent time to subtract */
834 if (index)
835 current->ret_stack[index - 1].subtime += calltime;
836
837 if (current->ret_stack[index].subtime < calltime)
838 calltime -= current->ret_stack[index].subtime;
839 else
840 calltime = 0;
841 }
842
Steven Rostedtcafb1682009-03-24 20:50:39 -0400843 rec = ftrace_find_profiled_func(stat, trace->func);
Chase Douglase330b3b2010-04-26 14:02:05 -0400844 if (rec) {
Steven Rostedta2a16d62009-03-24 23:17:58 -0400845 rec->time += calltime;
Chase Douglase330b3b2010-04-26 14:02:05 -0400846 rec->time_squared += calltime * calltime;
847 }
Steven Rostedta2a16d62009-03-24 23:17:58 -0400848
Steven Rostedtcafb1682009-03-24 20:50:39 -0400849 out:
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400850 local_irq_restore(flags);
851}
852
853static int register_ftrace_profiler(void)
854{
855 return register_ftrace_graph(&profile_graph_return,
856 &profile_graph_entry);
857}
858
859static void unregister_ftrace_profiler(void)
860{
861 unregister_ftrace_graph();
862}
863#else
Paul McQuadebd38c0e2011-05-31 20:51:55 +0100864static struct ftrace_ops ftrace_profile_ops __read_mostly = {
Steven Rostedtfb9fb012009-03-25 13:26:41 -0400865 .func = function_profile_call,
Steven Rostedt493762f2009-03-23 17:12:36 -0400866};
867
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400868static int register_ftrace_profiler(void)
869{
870 return register_ftrace_function(&ftrace_profile_ops);
871}
872
873static void unregister_ftrace_profiler(void)
874{
875 unregister_ftrace_function(&ftrace_profile_ops);
876}
877#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
878
Steven Rostedt493762f2009-03-23 17:12:36 -0400879static ssize_t
880ftrace_profile_write(struct file *filp, const char __user *ubuf,
881 size_t cnt, loff_t *ppos)
882{
883 unsigned long val;
Steven Rostedt493762f2009-03-23 17:12:36 -0400884 int ret;
885
Peter Huewe22fe9b52011-06-07 21:58:27 +0200886 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
887 if (ret)
Steven Rostedt493762f2009-03-23 17:12:36 -0400888 return ret;
889
890 val = !!val;
891
892 mutex_lock(&ftrace_profile_lock);
893 if (ftrace_profile_enabled ^ val) {
894 if (val) {
895 ret = ftrace_profile_init();
896 if (ret < 0) {
897 cnt = ret;
898 goto out;
899 }
900
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400901 ret = register_ftrace_profiler();
902 if (ret < 0) {
903 cnt = ret;
904 goto out;
905 }
Steven Rostedt493762f2009-03-23 17:12:36 -0400906 ftrace_profile_enabled = 1;
907 } else {
908 ftrace_profile_enabled = 0;
Steven Rostedt0f6ce3d2009-06-01 21:51:28 -0400909 /*
910 * unregister_ftrace_profiler calls stop_machine
911 * so this acts like an synchronize_sched.
912 */
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400913 unregister_ftrace_profiler();
Steven Rostedt493762f2009-03-23 17:12:36 -0400914 }
915 }
916 out:
917 mutex_unlock(&ftrace_profile_lock);
918
Jiri Olsacf8517c2009-10-23 19:36:16 -0400919 *ppos += cnt;
Steven Rostedt493762f2009-03-23 17:12:36 -0400920
921 return cnt;
922}
923
924static ssize_t
925ftrace_profile_read(struct file *filp, char __user *ubuf,
926 size_t cnt, loff_t *ppos)
927{
Steven Rostedtfb9fb012009-03-25 13:26:41 -0400928 char buf[64]; /* big enough to hold a number */
Steven Rostedt493762f2009-03-23 17:12:36 -0400929 int r;
930
931 r = sprintf(buf, "%u\n", ftrace_profile_enabled);
932 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
933}
934
935static const struct file_operations ftrace_profile_fops = {
936 .open = tracing_open_generic,
937 .read = ftrace_profile_read,
938 .write = ftrace_profile_write,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200939 .llseek = default_llseek,
Steven Rostedt493762f2009-03-23 17:12:36 -0400940};
941
Steven Rostedtcafb1682009-03-24 20:50:39 -0400942/* used to initialize the real stat files */
943static struct tracer_stat function_stats __initdata = {
Steven Rostedtfb9fb012009-03-25 13:26:41 -0400944 .name = "functions",
945 .stat_start = function_stat_start,
946 .stat_next = function_stat_next,
947 .stat_cmp = function_stat_cmp,
948 .stat_headers = function_stat_headers,
949 .stat_show = function_stat_show
Steven Rostedtcafb1682009-03-24 20:50:39 -0400950};
951
Steven Rostedt6ab5d662009-06-04 00:55:45 -0400952static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
Steven Rostedt493762f2009-03-23 17:12:36 -0400953{
Steven Rostedtcafb1682009-03-24 20:50:39 -0400954 struct ftrace_profile_stat *stat;
Steven Rostedt493762f2009-03-23 17:12:36 -0400955 struct dentry *entry;
Steven Rostedtcafb1682009-03-24 20:50:39 -0400956 char *name;
Steven Rostedt493762f2009-03-23 17:12:36 -0400957 int ret;
Steven Rostedtcafb1682009-03-24 20:50:39 -0400958 int cpu;
Steven Rostedt493762f2009-03-23 17:12:36 -0400959
Steven Rostedtcafb1682009-03-24 20:50:39 -0400960 for_each_possible_cpu(cpu) {
961 stat = &per_cpu(ftrace_profile_stats, cpu);
962
963 /* allocate enough for function name + cpu number */
964 name = kmalloc(32, GFP_KERNEL);
965 if (!name) {
966 /*
967 * The files created are permanent, if something happens
968 * we still do not free memory.
969 */
Steven Rostedtcafb1682009-03-24 20:50:39 -0400970 WARN(1,
971 "Could not allocate stat file for cpu %d\n",
972 cpu);
973 return;
974 }
975 stat->stat = function_stats;
976 snprintf(name, 32, "function%d", cpu);
977 stat->stat.name = name;
978 ret = register_stat_tracer(&stat->stat);
979 if (ret) {
980 WARN(1,
981 "Could not register function stat for cpu %d\n",
982 cpu);
983 kfree(name);
984 return;
985 }
Steven Rostedt493762f2009-03-23 17:12:36 -0400986 }
987
988 entry = debugfs_create_file("function_profile_enabled", 0644,
989 d_tracer, NULL, &ftrace_profile_fops);
990 if (!entry)
991 pr_warning("Could not create debugfs "
992 "'function_profile_enabled' entry\n");
993}
994
995#else /* CONFIG_FUNCTION_PROFILER */
Steven Rostedt6ab5d662009-06-04 00:55:45 -0400996static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
Steven Rostedt493762f2009-03-23 17:12:36 -0400997{
998}
999#endif /* CONFIG_FUNCTION_PROFILER */
1000
Ingo Molnar73d3fd92009-02-17 11:48:18 +01001001static struct pid * const ftrace_swapper_pid = &init_struct_pid;
1002
Steven Rostedt3d083392008-05-12 21:20:42 +02001003#ifdef CONFIG_DYNAMIC_FTRACE
Ingo Molnar73d3fd92009-02-17 11:48:18 +01001004
Steven Rostedt99ecdc42008-08-15 21:40:05 -04001005#ifndef CONFIG_FTRACE_MCOUNT_RECORD
Steven Rostedtcb7be3b2008-10-23 09:33:05 -04001006# error Dynamic ftrace depends on MCOUNT_RECORD
Steven Rostedt99ecdc42008-08-15 21:40:05 -04001007#endif
1008
Steven Rostedt8fc0c702009-02-16 15:28:00 -05001009static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly;
1010
Steven Rostedtb6887d72009-02-17 12:32:04 -05001011struct ftrace_func_probe {
Steven Rostedt8fc0c702009-02-16 15:28:00 -05001012 struct hlist_node node;
Steven Rostedtb6887d72009-02-17 12:32:04 -05001013 struct ftrace_probe_ops *ops;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05001014 unsigned long flags;
1015 unsigned long ip;
1016 void *data;
1017 struct rcu_head rcu;
1018};
1019
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001020struct ftrace_func_entry {
1021 struct hlist_node hlist;
1022 unsigned long ip;
1023};
1024
1025struct ftrace_hash {
1026 unsigned long size_bits;
1027 struct hlist_head *buckets;
1028 unsigned long count;
Steven Rostedt07fd5512011-05-05 18:03:47 -04001029 struct rcu_head rcu;
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001030};
1031
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001032/*
1033 * We make these constant because no one should touch them,
1034 * but they are used as the default "empty hash", to avoid allocating
1035 * it all the time. These are in a read only section such that if
1036 * anyone does try to modify it, it will cause an exception.
1037 */
1038static const struct hlist_head empty_buckets[1];
1039static const struct ftrace_hash empty_hash = {
1040 .buckets = (struct hlist_head *)empty_buckets,
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001041};
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001042#define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
Steven Rostedt5072c592008-05-12 21:20:43 +02001043
Steven Rostedt2b499382011-05-03 22:49:52 -04001044static struct ftrace_ops global_ops = {
Steven Rostedtf45948e2011-05-02 12:29:25 -04001045 .func = ftrace_stub,
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001046 .notrace_hash = EMPTY_HASH,
1047 .filter_hash = EMPTY_HASH,
Steven Rostedtf45948e2011-05-02 12:29:25 -04001048};
1049
Steven Rostedt41c52c02008-05-22 11:46:33 -04001050static DEFINE_MUTEX(ftrace_regex_lock);
Steven Rostedt3d083392008-05-12 21:20:42 +02001051
Steven Rostedt3c1720f2008-05-12 21:20:43 +02001052struct ftrace_page {
1053 struct ftrace_page *next;
Steven Rostedta7900872011-12-16 16:23:44 -05001054 struct dyn_ftrace *records;
Steven Rostedt431aa3f2009-01-06 12:43:01 -05001055 int index;
Steven Rostedta7900872011-12-16 16:23:44 -05001056 int size;
David Milleraa5e5ce2008-05-13 22:06:56 -07001057};
Steven Rostedt3c1720f2008-05-12 21:20:43 +02001058
Steven Rostedt85ae32a2011-12-16 16:30:31 -05001059static struct ftrace_page *ftrace_new_pgs;
1060
Steven Rostedta7900872011-12-16 16:23:44 -05001061#define ENTRY_SIZE sizeof(struct dyn_ftrace)
1062#define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
Steven Rostedt3c1720f2008-05-12 21:20:43 +02001063
1064/* estimate from running different kernels */
1065#define NR_TO_INIT 10000
1066
1067static struct ftrace_page *ftrace_pages_start;
1068static struct ftrace_page *ftrace_pages;
1069
Steven Rostedt06a51d92011-12-19 19:07:36 -05001070static bool ftrace_hash_empty(struct ftrace_hash *hash)
1071{
1072 return !hash || !hash->count;
1073}
1074
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001075static struct ftrace_func_entry *
1076ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1077{
1078 unsigned long key;
1079 struct ftrace_func_entry *entry;
1080 struct hlist_head *hhd;
1081 struct hlist_node *n;
1082
Steven Rostedt06a51d92011-12-19 19:07:36 -05001083 if (ftrace_hash_empty(hash))
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001084 return NULL;
1085
1086 if (hash->size_bits > 0)
1087 key = hash_long(ip, hash->size_bits);
1088 else
1089 key = 0;
1090
1091 hhd = &hash->buckets[key];
1092
1093 hlist_for_each_entry_rcu(entry, n, hhd, hlist) {
1094 if (entry->ip == ip)
1095 return entry;
1096 }
1097 return NULL;
1098}
1099
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001100static void __add_hash_entry(struct ftrace_hash *hash,
1101 struct ftrace_func_entry *entry)
1102{
1103 struct hlist_head *hhd;
1104 unsigned long key;
1105
1106 if (hash->size_bits)
1107 key = hash_long(entry->ip, hash->size_bits);
1108 else
1109 key = 0;
1110
1111 hhd = &hash->buckets[key];
1112 hlist_add_head(&entry->hlist, hhd);
1113 hash->count++;
1114}
1115
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001116static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
1117{
1118 struct ftrace_func_entry *entry;
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001119
1120 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1121 if (!entry)
1122 return -ENOMEM;
1123
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001124 entry->ip = ip;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001125 __add_hash_entry(hash, entry);
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001126
1127 return 0;
1128}
1129
1130static void
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001131free_hash_entry(struct ftrace_hash *hash,
1132 struct ftrace_func_entry *entry)
1133{
1134 hlist_del(&entry->hlist);
1135 kfree(entry);
1136 hash->count--;
1137}
1138
1139static void
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001140remove_hash_entry(struct ftrace_hash *hash,
1141 struct ftrace_func_entry *entry)
1142{
1143 hlist_del(&entry->hlist);
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001144 hash->count--;
1145}
1146
1147static void ftrace_hash_clear(struct ftrace_hash *hash)
1148{
1149 struct hlist_head *hhd;
1150 struct hlist_node *tp, *tn;
1151 struct ftrace_func_entry *entry;
1152 int size = 1 << hash->size_bits;
1153 int i;
1154
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001155 if (!hash->count)
1156 return;
1157
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001158 for (i = 0; i < size; i++) {
1159 hhd = &hash->buckets[i];
1160 hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist)
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001161 free_hash_entry(hash, entry);
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001162 }
1163 FTRACE_WARN_ON(hash->count);
1164}
1165
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001166static void free_ftrace_hash(struct ftrace_hash *hash)
1167{
1168 if (!hash || hash == EMPTY_HASH)
1169 return;
1170 ftrace_hash_clear(hash);
1171 kfree(hash->buckets);
1172 kfree(hash);
1173}
1174
Steven Rostedt07fd5512011-05-05 18:03:47 -04001175static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
1176{
1177 struct ftrace_hash *hash;
1178
1179 hash = container_of(rcu, struct ftrace_hash, rcu);
1180 free_ftrace_hash(hash);
1181}
1182
1183static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
1184{
1185 if (!hash || hash == EMPTY_HASH)
1186 return;
1187 call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu);
1188}
1189
Jiri Olsa5500fa52012-02-15 15:51:54 +01001190void ftrace_free_filter(struct ftrace_ops *ops)
1191{
1192 free_ftrace_hash(ops->filter_hash);
1193 free_ftrace_hash(ops->notrace_hash);
1194}
1195
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001196static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
1197{
1198 struct ftrace_hash *hash;
1199 int size;
1200
1201 hash = kzalloc(sizeof(*hash), GFP_KERNEL);
1202 if (!hash)
1203 return NULL;
1204
1205 size = 1 << size_bits;
Thomas Meyer47b0edc2011-11-29 22:08:00 +01001206 hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL);
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001207
1208 if (!hash->buckets) {
1209 kfree(hash);
1210 return NULL;
1211 }
1212
1213 hash->size_bits = size_bits;
1214
1215 return hash;
1216}
1217
1218static struct ftrace_hash *
1219alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
1220{
1221 struct ftrace_func_entry *entry;
1222 struct ftrace_hash *new_hash;
1223 struct hlist_node *tp;
1224 int size;
1225 int ret;
1226 int i;
1227
1228 new_hash = alloc_ftrace_hash(size_bits);
1229 if (!new_hash)
1230 return NULL;
1231
1232 /* Empty hash? */
Steven Rostedt06a51d92011-12-19 19:07:36 -05001233 if (ftrace_hash_empty(hash))
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001234 return new_hash;
1235
1236 size = 1 << hash->size_bits;
1237 for (i = 0; i < size; i++) {
1238 hlist_for_each_entry(entry, tp, &hash->buckets[i], hlist) {
1239 ret = add_hash_entry(new_hash, entry->ip);
1240 if (ret < 0)
1241 goto free_hash;
1242 }
1243 }
1244
1245 FTRACE_WARN_ON(new_hash->count != hash->count);
1246
1247 return new_hash;
1248
1249 free_hash:
1250 free_ftrace_hash(new_hash);
1251 return NULL;
1252}
1253
Steven Rostedt41fb61c2011-07-13 15:03:44 -04001254static void
1255ftrace_hash_rec_disable(struct ftrace_ops *ops, int filter_hash);
1256static void
1257ftrace_hash_rec_enable(struct ftrace_ops *ops, int filter_hash);
1258
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001259static int
Steven Rostedt41fb61c2011-07-13 15:03:44 -04001260ftrace_hash_move(struct ftrace_ops *ops, int enable,
1261 struct ftrace_hash **dst, struct ftrace_hash *src)
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001262{
1263 struct ftrace_func_entry *entry;
1264 struct hlist_node *tp, *tn;
1265 struct hlist_head *hhd;
Steven Rostedt07fd5512011-05-05 18:03:47 -04001266 struct ftrace_hash *old_hash;
1267 struct ftrace_hash *new_hash;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001268 unsigned long key;
1269 int size = src->count;
1270 int bits = 0;
Steven Rostedt41fb61c2011-07-13 15:03:44 -04001271 int ret;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001272 int i;
1273
1274 /*
Steven Rostedt41fb61c2011-07-13 15:03:44 -04001275 * Remove the current set, update the hash and add
1276 * them back.
1277 */
1278 ftrace_hash_rec_disable(ops, enable);
1279
1280 /*
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001281 * If the new source is empty, just free dst and assign it
1282 * the empty_hash.
1283 */
1284 if (!src->count) {
Steven Rostedt07fd5512011-05-05 18:03:47 -04001285 free_ftrace_hash_rcu(*dst);
1286 rcu_assign_pointer(*dst, EMPTY_HASH);
Steven Rostedtd4d34b92011-11-04 20:32:39 -04001287 /* still need to update the function records */
1288 ret = 0;
1289 goto out;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001290 }
1291
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001292 /*
1293 * Make the hash size about 1/2 the # found
1294 */
1295 for (size /= 2; size; size >>= 1)
1296 bits++;
1297
1298 /* Don't allocate too much */
1299 if (bits > FTRACE_HASH_MAX_BITS)
1300 bits = FTRACE_HASH_MAX_BITS;
1301
Steven Rostedt41fb61c2011-07-13 15:03:44 -04001302 ret = -ENOMEM;
Steven Rostedt07fd5512011-05-05 18:03:47 -04001303 new_hash = alloc_ftrace_hash(bits);
1304 if (!new_hash)
Steven Rostedt41fb61c2011-07-13 15:03:44 -04001305 goto out;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001306
1307 size = 1 << src->size_bits;
1308 for (i = 0; i < size; i++) {
1309 hhd = &src->buckets[i];
1310 hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist) {
1311 if (bits > 0)
1312 key = hash_long(entry->ip, bits);
1313 else
1314 key = 0;
1315 remove_hash_entry(src, entry);
Steven Rostedt07fd5512011-05-05 18:03:47 -04001316 __add_hash_entry(new_hash, entry);
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001317 }
1318 }
1319
Steven Rostedt07fd5512011-05-05 18:03:47 -04001320 old_hash = *dst;
1321 rcu_assign_pointer(*dst, new_hash);
1322 free_ftrace_hash_rcu(old_hash);
1323
Steven Rostedt41fb61c2011-07-13 15:03:44 -04001324 ret = 0;
1325 out:
1326 /*
1327 * Enable regardless of ret:
1328 * On success, we enable the new hash.
1329 * On failure, we re-enable the original hash.
1330 */
1331 ftrace_hash_rec_enable(ops, enable);
1332
1333 return ret;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001334}
1335
Steven Rostedt265c8312009-02-13 12:43:56 -05001336/*
Steven Rostedtb8489142011-05-04 09:27:52 -04001337 * Test the hashes for this ops to see if we want to call
1338 * the ops->func or not.
1339 *
1340 * It's a match if the ip is in the ops->filter_hash or
1341 * the filter_hash does not exist or is empty,
1342 * AND
1343 * the ip is not in the ops->notrace_hash.
Steven Rostedtcdbe61b2011-05-05 21:14:55 -04001344 *
1345 * This needs to be called with preemption disabled as
1346 * the hashes are freed with call_rcu_sched().
Steven Rostedtb8489142011-05-04 09:27:52 -04001347 */
1348static int
1349ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip)
1350{
1351 struct ftrace_hash *filter_hash;
1352 struct ftrace_hash *notrace_hash;
1353 int ret;
1354
Steven Rostedtb8489142011-05-04 09:27:52 -04001355 filter_hash = rcu_dereference_raw(ops->filter_hash);
1356 notrace_hash = rcu_dereference_raw(ops->notrace_hash);
1357
Steven Rostedt06a51d92011-12-19 19:07:36 -05001358 if ((ftrace_hash_empty(filter_hash) ||
Steven Rostedtb8489142011-05-04 09:27:52 -04001359 ftrace_lookup_ip(filter_hash, ip)) &&
Steven Rostedt06a51d92011-12-19 19:07:36 -05001360 (ftrace_hash_empty(notrace_hash) ||
Steven Rostedtb8489142011-05-04 09:27:52 -04001361 !ftrace_lookup_ip(notrace_hash, ip)))
1362 ret = 1;
1363 else
1364 ret = 0;
Steven Rostedtb8489142011-05-04 09:27:52 -04001365
1366 return ret;
1367}
1368
1369/*
Steven Rostedt265c8312009-02-13 12:43:56 -05001370 * This is a double for. Do not use 'break' to break out of the loop,
1371 * you must use a goto.
1372 */
1373#define do_for_each_ftrace_rec(pg, rec) \
1374 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1375 int _____i; \
1376 for (_____i = 0; _____i < pg->index; _____i++) { \
1377 rec = &pg->records[_____i];
1378
1379#define while_for_each_ftrace_rec() \
1380 } \
1381 }
Abhishek Sagarecea6562008-06-21 23:47:53 +05301382
Steven Rostedt5855fea2011-12-16 19:27:42 -05001383
1384static int ftrace_cmp_recs(const void *a, const void *b)
1385{
1386 const struct dyn_ftrace *reca = a;
1387 const struct dyn_ftrace *recb = b;
1388
1389 if (reca->ip > recb->ip)
1390 return 1;
1391 if (reca->ip < recb->ip)
1392 return -1;
1393 return 0;
1394}
1395
Steven Rostedtc88fd862011-08-16 09:53:39 -04001396/**
1397 * ftrace_location - return true if the ip giving is a traced location
1398 * @ip: the instruction pointer to check
1399 *
1400 * Returns 1 if @ip given is a pointer to a ftrace location.
1401 * That is, the instruction that is either a NOP or call to
1402 * the function tracer. It checks the ftrace internal tables to
1403 * determine if the address belongs or not.
1404 */
1405int ftrace_location(unsigned long ip)
1406{
1407 struct ftrace_page *pg;
1408 struct dyn_ftrace *rec;
Steven Rostedt5855fea2011-12-16 19:27:42 -05001409 struct dyn_ftrace key;
Steven Rostedtc88fd862011-08-16 09:53:39 -04001410
Steven Rostedt5855fea2011-12-16 19:27:42 -05001411 key.ip = ip;
1412
1413 for (pg = ftrace_pages_start; pg; pg = pg->next) {
1414 rec = bsearch(&key, pg->records, pg->index,
1415 sizeof(struct dyn_ftrace),
1416 ftrace_cmp_recs);
1417 if (rec)
Steven Rostedtc88fd862011-08-16 09:53:39 -04001418 return 1;
Steven Rostedt5855fea2011-12-16 19:27:42 -05001419 }
Steven Rostedtc88fd862011-08-16 09:53:39 -04001420
1421 return 0;
1422}
1423
Steven Rostedted926f92011-05-03 13:25:24 -04001424static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
1425 int filter_hash,
1426 bool inc)
1427{
1428 struct ftrace_hash *hash;
1429 struct ftrace_hash *other_hash;
1430 struct ftrace_page *pg;
1431 struct dyn_ftrace *rec;
1432 int count = 0;
1433 int all = 0;
1434
1435 /* Only update if the ops has been registered */
1436 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1437 return;
1438
1439 /*
1440 * In the filter_hash case:
1441 * If the count is zero, we update all records.
1442 * Otherwise we just update the items in the hash.
1443 *
1444 * In the notrace_hash case:
1445 * We enable the update in the hash.
1446 * As disabling notrace means enabling the tracing,
1447 * and enabling notrace means disabling, the inc variable
1448 * gets inversed.
1449 */
1450 if (filter_hash) {
1451 hash = ops->filter_hash;
1452 other_hash = ops->notrace_hash;
Steven Rostedt06a51d92011-12-19 19:07:36 -05001453 if (ftrace_hash_empty(hash))
Steven Rostedted926f92011-05-03 13:25:24 -04001454 all = 1;
1455 } else {
1456 inc = !inc;
1457 hash = ops->notrace_hash;
1458 other_hash = ops->filter_hash;
1459 /*
1460 * If the notrace hash has no items,
1461 * then there's nothing to do.
1462 */
Steven Rostedt06a51d92011-12-19 19:07:36 -05001463 if (ftrace_hash_empty(hash))
Steven Rostedted926f92011-05-03 13:25:24 -04001464 return;
1465 }
1466
1467 do_for_each_ftrace_rec(pg, rec) {
1468 int in_other_hash = 0;
1469 int in_hash = 0;
1470 int match = 0;
1471
1472 if (all) {
1473 /*
1474 * Only the filter_hash affects all records.
1475 * Update if the record is not in the notrace hash.
1476 */
Steven Rostedtb8489142011-05-04 09:27:52 -04001477 if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
Steven Rostedted926f92011-05-03 13:25:24 -04001478 match = 1;
1479 } else {
Steven Rostedt06a51d92011-12-19 19:07:36 -05001480 in_hash = !!ftrace_lookup_ip(hash, rec->ip);
1481 in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip);
Steven Rostedted926f92011-05-03 13:25:24 -04001482
1483 /*
1484 *
1485 */
1486 if (filter_hash && in_hash && !in_other_hash)
1487 match = 1;
1488 else if (!filter_hash && in_hash &&
Steven Rostedt06a51d92011-12-19 19:07:36 -05001489 (in_other_hash || ftrace_hash_empty(other_hash)))
Steven Rostedted926f92011-05-03 13:25:24 -04001490 match = 1;
1491 }
1492 if (!match)
1493 continue;
1494
1495 if (inc) {
1496 rec->flags++;
1497 if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == FTRACE_REF_MAX))
1498 return;
1499 } else {
1500 if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == 0))
1501 return;
1502 rec->flags--;
1503 }
1504 count++;
1505 /* Shortcut, if we handled all records, we are done. */
1506 if (!all && count == hash->count)
1507 return;
1508 } while_for_each_ftrace_rec();
1509}
1510
1511static void ftrace_hash_rec_disable(struct ftrace_ops *ops,
1512 int filter_hash)
1513{
1514 __ftrace_hash_rec_update(ops, filter_hash, 0);
1515}
1516
1517static void ftrace_hash_rec_enable(struct ftrace_ops *ops,
1518 int filter_hash)
1519{
1520 __ftrace_hash_rec_update(ops, filter_hash, 1);
1521}
1522
Steven Rostedt05736a42008-09-22 14:55:47 -07001523static void print_ip_ins(const char *fmt, unsigned char *p)
1524{
1525 int i;
1526
1527 printk(KERN_CONT "%s", fmt);
1528
1529 for (i = 0; i < MCOUNT_INSN_SIZE; i++)
1530 printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
1531}
1532
Steven Rostedtc88fd862011-08-16 09:53:39 -04001533/**
1534 * ftrace_bug - report and shutdown function tracer
1535 * @failed: The failed type (EFAULT, EINVAL, EPERM)
1536 * @ip: The address that failed
1537 *
1538 * The arch code that enables or disables the function tracing
1539 * can call ftrace_bug() when it has detected a problem in
1540 * modifying the code. @failed should be one of either:
1541 * EFAULT - if the problem happens on reading the @ip address
1542 * EINVAL - if what is read at @ip is not what was expected
1543 * EPERM - if the problem happens on writting to the @ip address
1544 */
1545void ftrace_bug(int failed, unsigned long ip)
Steven Rostedtb17e8a32008-11-14 16:21:19 -08001546{
1547 switch (failed) {
1548 case -EFAULT:
1549 FTRACE_WARN_ON_ONCE(1);
1550 pr_info("ftrace faulted on modifying ");
1551 print_ip_sym(ip);
1552 break;
1553 case -EINVAL:
1554 FTRACE_WARN_ON_ONCE(1);
1555 pr_info("ftrace failed to modify ");
1556 print_ip_sym(ip);
Steven Rostedtb17e8a32008-11-14 16:21:19 -08001557 print_ip_ins(" actual: ", (unsigned char *)ip);
Steven Rostedtb17e8a32008-11-14 16:21:19 -08001558 printk(KERN_CONT "\n");
1559 break;
1560 case -EPERM:
1561 FTRACE_WARN_ON_ONCE(1);
1562 pr_info("ftrace faulted on writing ");
1563 print_ip_sym(ip);
1564 break;
1565 default:
1566 FTRACE_WARN_ON_ONCE(1);
1567 pr_info("ftrace faulted on unknown error ");
1568 print_ip_sym(ip);
1569 }
1570}
1571
Steven Rostedt3c1720f2008-05-12 21:20:43 +02001572
Masami Hiramatsu2cfa1972010-02-02 16:49:11 -05001573/* Return 1 if the address range is reserved for ftrace */
1574int ftrace_text_reserved(void *start, void *end)
1575{
1576 struct dyn_ftrace *rec;
1577 struct ftrace_page *pg;
1578
1579 do_for_each_ftrace_rec(pg, rec) {
1580 if (rec->ip <= (unsigned long)end &&
1581 rec->ip + MCOUNT_INSN_SIZE > (unsigned long)start)
1582 return 1;
1583 } while_for_each_ftrace_rec();
1584 return 0;
1585}
1586
Steven Rostedtc88fd862011-08-16 09:53:39 -04001587static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
Steven Rostedt5072c592008-05-12 21:20:43 +02001588{
Xiao Guangrong64fbcd12009-07-15 12:32:15 +08001589 unsigned long flag = 0UL;
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01001590
Steven Rostedt982c3502008-11-15 16:31:41 -05001591 /*
Jiri Olsa30fb6aa2011-12-05 18:22:48 +01001592 * If we are updating calls:
Steven Rostedt982c3502008-11-15 16:31:41 -05001593 *
Steven Rostedted926f92011-05-03 13:25:24 -04001594 * If the record has a ref count, then we need to enable it
1595 * because someone is using it.
Steven Rostedt982c3502008-11-15 16:31:41 -05001596 *
Steven Rostedted926f92011-05-03 13:25:24 -04001597 * Otherwise we make sure its disabled.
1598 *
Jiri Olsa30fb6aa2011-12-05 18:22:48 +01001599 * If we are disabling calls, then disable all records that
Steven Rostedted926f92011-05-03 13:25:24 -04001600 * are enabled.
Steven Rostedt982c3502008-11-15 16:31:41 -05001601 */
Steven Rostedtc88fd862011-08-16 09:53:39 -04001602 if (enable && (rec->flags & ~FTRACE_FL_MASK))
Steven Rostedted926f92011-05-03 13:25:24 -04001603 flag = FTRACE_FL_ENABLED;
Steven Rostedt5072c592008-05-12 21:20:43 +02001604
Xiao Guangrong64fbcd12009-07-15 12:32:15 +08001605 /* If the state of this record hasn't changed, then do nothing */
1606 if ((rec->flags & FTRACE_FL_ENABLED) == flag)
Steven Rostedtc88fd862011-08-16 09:53:39 -04001607 return FTRACE_UPDATE_IGNORE;
Xiao Guangrong64fbcd12009-07-15 12:32:15 +08001608
1609 if (flag) {
Steven Rostedtc88fd862011-08-16 09:53:39 -04001610 if (update)
1611 rec->flags |= FTRACE_FL_ENABLED;
1612 return FTRACE_UPDATE_MAKE_CALL;
Xiao Guangrong64fbcd12009-07-15 12:32:15 +08001613 }
1614
Steven Rostedtc88fd862011-08-16 09:53:39 -04001615 if (update)
1616 rec->flags &= ~FTRACE_FL_ENABLED;
1617
1618 return FTRACE_UPDATE_MAKE_NOP;
1619}
1620
1621/**
1622 * ftrace_update_record, set a record that now is tracing or not
1623 * @rec: the record to update
1624 * @enable: set to 1 if the record is tracing, zero to force disable
1625 *
1626 * The records that represent all functions that can be traced need
1627 * to be updated when tracing has been enabled.
1628 */
1629int ftrace_update_record(struct dyn_ftrace *rec, int enable)
1630{
1631 return ftrace_check_record(rec, enable, 1);
1632}
1633
1634/**
1635 * ftrace_test_record, check if the record has been enabled or not
1636 * @rec: the record to test
1637 * @enable: set to 1 to check if enabled, 0 if it is disabled
1638 *
1639 * The arch code may need to test if a record is already set to
1640 * tracing to determine how to modify the function code that it
1641 * represents.
1642 */
1643int ftrace_test_record(struct dyn_ftrace *rec, int enable)
1644{
1645 return ftrace_check_record(rec, enable, 0);
1646}
1647
1648static int
1649__ftrace_replace_code(struct dyn_ftrace *rec, int enable)
1650{
1651 unsigned long ftrace_addr;
1652 int ret;
1653
1654 ftrace_addr = (unsigned long)FTRACE_ADDR;
1655
1656 ret = ftrace_update_record(rec, enable);
1657
1658 switch (ret) {
1659 case FTRACE_UPDATE_IGNORE:
1660 return 0;
1661
1662 case FTRACE_UPDATE_MAKE_CALL:
1663 return ftrace_make_call(rec, ftrace_addr);
1664
1665 case FTRACE_UPDATE_MAKE_NOP:
1666 return ftrace_make_nop(NULL, rec, ftrace_addr);
1667 }
1668
1669 return -1; /* unknow ftrace bug */
Steven Rostedt5072c592008-05-12 21:20:43 +02001670}
1671
Jiri Olsa30fb6aa2011-12-05 18:22:48 +01001672static void ftrace_replace_code(int update)
Steven Rostedt3c1720f2008-05-12 21:20:43 +02001673{
Steven Rostedt3c1720f2008-05-12 21:20:43 +02001674 struct dyn_ftrace *rec;
1675 struct ftrace_page *pg;
Steven Rostedt6a24a242009-02-17 11:20:26 -05001676 int failed;
Steven Rostedt3c1720f2008-05-12 21:20:43 +02001677
Steven Rostedt45a4a232011-04-21 23:16:46 -04001678 if (unlikely(ftrace_disabled))
1679 return;
1680
Steven Rostedt265c8312009-02-13 12:43:56 -05001681 do_for_each_ftrace_rec(pg, rec) {
Jiri Olsa30fb6aa2011-12-05 18:22:48 +01001682 failed = __ftrace_replace_code(rec, update);
Zhaoleifa9d13c2009-03-13 17:16:34 +08001683 if (failed) {
Steven Rostedt3279ba32009-10-07 16:57:56 -04001684 ftrace_bug(failed, rec->ip);
1685 /* Stop processing */
1686 return;
Steven Rostedt265c8312009-02-13 12:43:56 -05001687 }
1688 } while_for_each_ftrace_rec();
Steven Rostedt3c1720f2008-05-12 21:20:43 +02001689}
1690
Steven Rostedtc88fd862011-08-16 09:53:39 -04001691struct ftrace_rec_iter {
1692 struct ftrace_page *pg;
1693 int index;
1694};
1695
1696/**
1697 * ftrace_rec_iter_start, start up iterating over traced functions
1698 *
1699 * Returns an iterator handle that is used to iterate over all
1700 * the records that represent address locations where functions
1701 * are traced.
1702 *
1703 * May return NULL if no records are available.
1704 */
1705struct ftrace_rec_iter *ftrace_rec_iter_start(void)
1706{
1707 /*
1708 * We only use a single iterator.
1709 * Protected by the ftrace_lock mutex.
1710 */
1711 static struct ftrace_rec_iter ftrace_rec_iter;
1712 struct ftrace_rec_iter *iter = &ftrace_rec_iter;
1713
1714 iter->pg = ftrace_pages_start;
1715 iter->index = 0;
1716
1717 /* Could have empty pages */
1718 while (iter->pg && !iter->pg->index)
1719 iter->pg = iter->pg->next;
1720
1721 if (!iter->pg)
1722 return NULL;
1723
1724 return iter;
1725}
1726
1727/**
1728 * ftrace_rec_iter_next, get the next record to process.
1729 * @iter: The handle to the iterator.
1730 *
1731 * Returns the next iterator after the given iterator @iter.
1732 */
1733struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter)
1734{
1735 iter->index++;
1736
1737 if (iter->index >= iter->pg->index) {
1738 iter->pg = iter->pg->next;
1739 iter->index = 0;
1740
1741 /* Could have empty pages */
1742 while (iter->pg && !iter->pg->index)
1743 iter->pg = iter->pg->next;
1744 }
1745
1746 if (!iter->pg)
1747 return NULL;
1748
1749 return iter;
1750}
1751
1752/**
1753 * ftrace_rec_iter_record, get the record at the iterator location
1754 * @iter: The current iterator location
1755 *
1756 * Returns the record that the current @iter is at.
1757 */
1758struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
1759{
1760 return &iter->pg->records[iter->index];
1761}
1762
Abhishek Sagar492a7ea52008-05-25 00:10:04 +05301763static int
Steven Rostedt31e88902008-11-14 16:21:19 -08001764ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
Steven Rostedt3c1720f2008-05-12 21:20:43 +02001765{
1766 unsigned long ip;
Steven Rostedt593eb8a2008-10-23 09:32:59 -04001767 int ret;
Steven Rostedt3c1720f2008-05-12 21:20:43 +02001768
1769 ip = rec->ip;
1770
Steven Rostedt45a4a232011-04-21 23:16:46 -04001771 if (unlikely(ftrace_disabled))
1772 return 0;
1773
Shaohua Li25aac9d2009-01-09 11:29:40 +08001774 ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
Steven Rostedt593eb8a2008-10-23 09:32:59 -04001775 if (ret) {
Steven Rostedt31e88902008-11-14 16:21:19 -08001776 ftrace_bug(ret, ip);
Abhishek Sagar492a7ea52008-05-25 00:10:04 +05301777 return 0;
Steven Rostedt37ad5082008-05-12 21:20:48 +02001778 }
Abhishek Sagar492a7ea52008-05-25 00:10:04 +05301779 return 1;
Steven Rostedt3c1720f2008-05-12 21:20:43 +02001780}
1781
Steven Rostedt000ab692009-02-17 13:35:06 -05001782/*
1783 * archs can override this function if they must do something
1784 * before the modifying code is performed.
1785 */
1786int __weak ftrace_arch_code_modify_prepare(void)
1787{
1788 return 0;
1789}
1790
1791/*
1792 * archs can override this function if they must do something
1793 * after the modifying code is performed.
1794 */
1795int __weak ftrace_arch_code_modify_post_process(void)
1796{
1797 return 0;
1798}
1799
Ingo Molnare309b412008-05-12 21:20:51 +02001800static int __ftrace_modify_code(void *data)
Steven Rostedt3d083392008-05-12 21:20:42 +02001801{
Steven Rostedtd61f82d2008-05-12 21:20:43 +02001802 int *command = data;
1803
Jiri Olsa30fb6aa2011-12-05 18:22:48 +01001804 if (*command & FTRACE_UPDATE_CALLS)
Steven Rostedtd61f82d2008-05-12 21:20:43 +02001805 ftrace_replace_code(1);
Steven Rostedta3583242008-11-11 15:01:42 -05001806 else if (*command & FTRACE_DISABLE_CALLS)
Steven Rostedtd61f82d2008-05-12 21:20:43 +02001807 ftrace_replace_code(0);
1808
1809 if (*command & FTRACE_UPDATE_TRACE_FUNC)
1810 ftrace_update_ftrace_func(ftrace_trace_function);
1811
Steven Rostedt5a45cfe2008-11-26 00:16:24 -05001812 if (*command & FTRACE_START_FUNC_RET)
1813 ftrace_enable_ftrace_graph_caller();
1814 else if (*command & FTRACE_STOP_FUNC_RET)
1815 ftrace_disable_ftrace_graph_caller();
1816
Steven Rostedtc88fd862011-08-16 09:53:39 -04001817 return 0;
1818}
1819
1820/**
1821 * ftrace_run_stop_machine, go back to the stop machine method
1822 * @command: The command to tell ftrace what to do
1823 *
1824 * If an arch needs to fall back to the stop machine method, the
1825 * it can call this function.
1826 */
1827void ftrace_run_stop_machine(int command)
1828{
1829 stop_machine(__ftrace_modify_code, &command, NULL);
1830}
1831
1832/**
1833 * arch_ftrace_update_code, modify the code to trace or not trace
1834 * @command: The command that needs to be done
1835 *
1836 * Archs can override this function if it does not need to
1837 * run stop_machine() to modify code.
1838 */
1839void __weak arch_ftrace_update_code(int command)
1840{
1841 ftrace_run_stop_machine(command);
1842}
1843
1844static void ftrace_run_update_code(int command)
1845{
1846 int ret;
1847
1848 ret = ftrace_arch_code_modify_prepare();
1849 FTRACE_WARN_ON(ret);
1850 if (ret)
1851 return;
1852 /*
1853 * Do not call function tracer while we update the code.
1854 * We are in stop machine.
1855 */
1856 function_trace_stop++;
1857
1858 /*
1859 * By default we use stop_machine() to modify the code.
1860 * But archs can do what ever they want as long as it
1861 * is safe. The stop_machine() is the safest, but also
1862 * produces the most overhead.
1863 */
1864 arch_ftrace_update_code(command);
1865
Steven Rostedt6331c282011-07-13 15:11:02 -04001866#ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
1867 /*
1868 * For archs that call ftrace_test_stop_func(), we must
1869 * wait till after we update all the function callers
1870 * before we update the callback. This keeps different
1871 * ops that record different functions from corrupting
1872 * each other.
1873 */
1874 __ftrace_trace_function = __ftrace_trace_function_delay;
1875#endif
1876 function_trace_stop--;
1877
Steven Rostedt000ab692009-02-17 13:35:06 -05001878 ret = ftrace_arch_code_modify_post_process();
1879 FTRACE_WARN_ON(ret);
Steven Rostedt3d083392008-05-12 21:20:42 +02001880}
1881
Steven Rostedtd61f82d2008-05-12 21:20:43 +02001882static ftrace_func_t saved_ftrace_func;
Steven Rostedt60a7ecf2008-11-05 16:05:44 -05001883static int ftrace_start_up;
Steven Rostedtb8489142011-05-04 09:27:52 -04001884static int global_start_up;
Steven Rostedtdf4fc312008-11-26 00:16:23 -05001885
1886static void ftrace_startup_enable(int command)
1887{
1888 if (saved_ftrace_func != ftrace_trace_function) {
1889 saved_ftrace_func = ftrace_trace_function;
1890 command |= FTRACE_UPDATE_TRACE_FUNC;
1891 }
1892
1893 if (!command || !ftrace_enabled)
1894 return;
1895
1896 ftrace_run_update_code(command);
1897}
Steven Rostedtd61f82d2008-05-12 21:20:43 +02001898
Steven Rostedta1cd6172011-05-23 15:24:25 -04001899static int ftrace_startup(struct ftrace_ops *ops, int command)
Steven Rostedt3d083392008-05-12 21:20:42 +02001900{
Steven Rostedtb8489142011-05-04 09:27:52 -04001901 bool hash_enable = true;
1902
Steven Rostedt4eebcc82008-05-12 21:20:48 +02001903 if (unlikely(ftrace_disabled))
Steven Rostedta1cd6172011-05-23 15:24:25 -04001904 return -ENODEV;
Steven Rostedt4eebcc82008-05-12 21:20:48 +02001905
Steven Rostedt60a7ecf2008-11-05 16:05:44 -05001906 ftrace_start_up++;
Jiri Olsa30fb6aa2011-12-05 18:22:48 +01001907 command |= FTRACE_UPDATE_CALLS;
Steven Rostedt3d083392008-05-12 21:20:42 +02001908
Steven Rostedtb8489142011-05-04 09:27:52 -04001909 /* ops marked global share the filter hashes */
1910 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
1911 ops = &global_ops;
1912 /* Don't update hash if global is already set */
1913 if (global_start_up)
1914 hash_enable = false;
1915 global_start_up++;
1916 }
1917
Steven Rostedted926f92011-05-03 13:25:24 -04001918 ops->flags |= FTRACE_OPS_FL_ENABLED;
Steven Rostedtb8489142011-05-04 09:27:52 -04001919 if (hash_enable)
Steven Rostedted926f92011-05-03 13:25:24 -04001920 ftrace_hash_rec_enable(ops, 1);
1921
Steven Rostedtdf4fc312008-11-26 00:16:23 -05001922 ftrace_startup_enable(command);
Steven Rostedta1cd6172011-05-23 15:24:25 -04001923
1924 return 0;
Steven Rostedt3d083392008-05-12 21:20:42 +02001925}
1926
Steven Rostedtbd69c302011-05-03 21:55:54 -04001927static void ftrace_shutdown(struct ftrace_ops *ops, int command)
Steven Rostedt3d083392008-05-12 21:20:42 +02001928{
Steven Rostedtb8489142011-05-04 09:27:52 -04001929 bool hash_disable = true;
1930
Steven Rostedt4eebcc82008-05-12 21:20:48 +02001931 if (unlikely(ftrace_disabled))
1932 return;
1933
Steven Rostedt60a7ecf2008-11-05 16:05:44 -05001934 ftrace_start_up--;
Frederic Weisbecker9ea1a152009-06-20 06:52:21 +02001935 /*
1936 * Just warn in case of unbalance, no need to kill ftrace, it's not
1937 * critical but the ftrace_call callers may be never nopped again after
1938 * further ftrace uses.
1939 */
1940 WARN_ON_ONCE(ftrace_start_up < 0);
1941
Steven Rostedtb8489142011-05-04 09:27:52 -04001942 if (ops->flags & FTRACE_OPS_FL_GLOBAL) {
1943 ops = &global_ops;
1944 global_start_up--;
1945 WARN_ON_ONCE(global_start_up < 0);
1946 /* Don't update hash if global still has users */
1947 if (global_start_up) {
1948 WARN_ON_ONCE(!ftrace_start_up);
1949 hash_disable = false;
1950 }
1951 }
1952
1953 if (hash_disable)
Steven Rostedted926f92011-05-03 13:25:24 -04001954 ftrace_hash_rec_disable(ops, 1);
1955
Steven Rostedtb8489142011-05-04 09:27:52 -04001956 if (ops != &global_ops || !global_start_up)
Steven Rostedted926f92011-05-03 13:25:24 -04001957 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
Steven Rostedtb8489142011-05-04 09:27:52 -04001958
Jiri Olsa30fb6aa2011-12-05 18:22:48 +01001959 command |= FTRACE_UPDATE_CALLS;
Steven Rostedtd61f82d2008-05-12 21:20:43 +02001960
1961 if (saved_ftrace_func != ftrace_trace_function) {
1962 saved_ftrace_func = ftrace_trace_function;
1963 command |= FTRACE_UPDATE_TRACE_FUNC;
1964 }
1965
1966 if (!command || !ftrace_enabled)
Steven Rostedte6ea44e2009-02-14 01:42:44 -05001967 return;
Steven Rostedt3d083392008-05-12 21:20:42 +02001968
Steven Rostedtd61f82d2008-05-12 21:20:43 +02001969 ftrace_run_update_code(command);
Steven Rostedt3d083392008-05-12 21:20:42 +02001970}
1971
Ingo Molnare309b412008-05-12 21:20:51 +02001972static void ftrace_startup_sysctl(void)
Steven Rostedtb0fc4942008-05-12 21:20:43 +02001973{
Steven Rostedt4eebcc82008-05-12 21:20:48 +02001974 if (unlikely(ftrace_disabled))
1975 return;
1976
Steven Rostedtd61f82d2008-05-12 21:20:43 +02001977 /* Force update next time */
1978 saved_ftrace_func = NULL;
Steven Rostedt60a7ecf2008-11-05 16:05:44 -05001979 /* ftrace_start_up is true if we want ftrace running */
1980 if (ftrace_start_up)
Jiri Olsa30fb6aa2011-12-05 18:22:48 +01001981 ftrace_run_update_code(FTRACE_UPDATE_CALLS);
Steven Rostedtb0fc4942008-05-12 21:20:43 +02001982}
1983
Ingo Molnare309b412008-05-12 21:20:51 +02001984static void ftrace_shutdown_sysctl(void)
Steven Rostedtb0fc4942008-05-12 21:20:43 +02001985{
Steven Rostedt4eebcc82008-05-12 21:20:48 +02001986 if (unlikely(ftrace_disabled))
1987 return;
1988
Steven Rostedt60a7ecf2008-11-05 16:05:44 -05001989 /* ftrace_start_up is true if ftrace is running */
1990 if (ftrace_start_up)
Steven Rostedt79e406d2010-09-14 22:19:46 -04001991 ftrace_run_update_code(FTRACE_DISABLE_CALLS);
Steven Rostedtb0fc4942008-05-12 21:20:43 +02001992}
1993
Steven Rostedt3d083392008-05-12 21:20:42 +02001994static cycle_t ftrace_update_time;
1995static unsigned long ftrace_update_cnt;
1996unsigned long ftrace_update_tot_cnt;
1997
Steven Rostedtf7bc8b62011-07-14 23:02:27 -04001998static int ops_traces_mod(struct ftrace_ops *ops)
1999{
2000 struct ftrace_hash *hash;
2001
2002 hash = ops->filter_hash;
Steven Rostedt06a51d92011-12-19 19:07:36 -05002003 return ftrace_hash_empty(hash);
Steven Rostedtf7bc8b62011-07-14 23:02:27 -04002004}
2005
Steven Rostedt31e88902008-11-14 16:21:19 -08002006static int ftrace_update_code(struct module *mod)
Steven Rostedt3d083392008-05-12 21:20:42 +02002007{
Steven Rostedt85ae32a2011-12-16 16:30:31 -05002008 struct ftrace_page *pg;
Lai Jiangshane94142a2009-03-13 17:51:27 +08002009 struct dyn_ftrace *p;
Abhishek Sagarf22f9a82008-06-21 23:50:29 +05302010 cycle_t start, stop;
Steven Rostedtf7bc8b62011-07-14 23:02:27 -04002011 unsigned long ref = 0;
Steven Rostedt85ae32a2011-12-16 16:30:31 -05002012 int i;
Steven Rostedtf7bc8b62011-07-14 23:02:27 -04002013
2014 /*
2015 * When adding a module, we need to check if tracers are
2016 * currently enabled and if they are set to trace all functions.
2017 * If they are, we need to enable the module functions as well
2018 * as update the reference counts for those function records.
2019 */
2020 if (mod) {
2021 struct ftrace_ops *ops;
2022
2023 for (ops = ftrace_ops_list;
2024 ops != &ftrace_list_end; ops = ops->next) {
2025 if (ops->flags & FTRACE_OPS_FL_ENABLED &&
2026 ops_traces_mod(ops))
2027 ref++;
2028 }
2029 }
Steven Rostedt3d083392008-05-12 21:20:42 +02002030
Ingo Molnar750ed1a2008-05-12 21:20:46 +02002031 start = ftrace_now(raw_smp_processor_id());
Steven Rostedt3d083392008-05-12 21:20:42 +02002032 ftrace_update_cnt = 0;
2033
Steven Rostedt85ae32a2011-12-16 16:30:31 -05002034 for (pg = ftrace_new_pgs; pg; pg = pg->next) {
Abhishek Sagarf22f9a82008-06-21 23:50:29 +05302035
Steven Rostedt85ae32a2011-12-16 16:30:31 -05002036 for (i = 0; i < pg->index; i++) {
2037 /* If something went wrong, bail without enabling anything */
2038 if (unlikely(ftrace_disabled))
2039 return -1;
Steven Rostedt3d083392008-05-12 21:20:42 +02002040
Steven Rostedt85ae32a2011-12-16 16:30:31 -05002041 p = &pg->records[i];
2042 p->flags = ref;
Abhishek Sagar0eb96702008-06-01 21:47:30 +05302043
Steven Rostedt85ae32a2011-12-16 16:30:31 -05002044 /*
2045 * Do the initial record conversion from mcount jump
2046 * to the NOP instructions.
2047 */
2048 if (!ftrace_code_disable(mod, p))
2049 break;
Jiri Olsa5cb084b2009-10-13 16:33:53 -04002050
Steven Rostedt85ae32a2011-12-16 16:30:31 -05002051 ftrace_update_cnt++;
Jiri Olsa5cb084b2009-10-13 16:33:53 -04002052
Steven Rostedt85ae32a2011-12-16 16:30:31 -05002053 /*
2054 * If the tracing is enabled, go ahead and enable the record.
2055 *
2056 * The reason not to enable the record immediatelly is the
2057 * inherent check of ftrace_make_nop/ftrace_make_call for
2058 * correct previous instructions. Making first the NOP
2059 * conversion puts the module to the correct state, thus
2060 * passing the ftrace_make_call check.
2061 */
2062 if (ftrace_start_up && ref) {
2063 int failed = __ftrace_replace_code(p, 1);
2064 if (failed)
2065 ftrace_bug(failed, p->ip);
2066 }
Jiri Olsa5cb084b2009-10-13 16:33:53 -04002067 }
Steven Rostedt3d083392008-05-12 21:20:42 +02002068 }
2069
Steven Rostedt85ae32a2011-12-16 16:30:31 -05002070 ftrace_new_pgs = NULL;
2071
Ingo Molnar750ed1a2008-05-12 21:20:46 +02002072 stop = ftrace_now(raw_smp_processor_id());
Steven Rostedt3d083392008-05-12 21:20:42 +02002073 ftrace_update_time = stop - start;
2074 ftrace_update_tot_cnt += ftrace_update_cnt;
2075
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +02002076 return 0;
2077}
2078
Steven Rostedta7900872011-12-16 16:23:44 -05002079static int ftrace_allocate_records(struct ftrace_page *pg, int count)
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002080{
Steven Rostedta7900872011-12-16 16:23:44 -05002081 int order;
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002082 int cnt;
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002083
Steven Rostedta7900872011-12-16 16:23:44 -05002084 if (WARN_ON(!count))
2085 return -EINVAL;
2086
2087 order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE));
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002088
2089 /*
Steven Rostedta7900872011-12-16 16:23:44 -05002090 * We want to fill as much as possible. No more than a page
2091 * may be empty.
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002092 */
Steven Rostedta7900872011-12-16 16:23:44 -05002093 while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE)
2094 order--;
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002095
Steven Rostedta7900872011-12-16 16:23:44 -05002096 again:
2097 pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
2098
2099 if (!pg->records) {
2100 /* if we can't allocate this size, try something smaller */
2101 if (!order)
2102 return -ENOMEM;
2103 order >>= 1;
2104 goto again;
2105 }
2106
2107 cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
2108 pg->size = cnt;
2109
2110 if (cnt > count)
2111 cnt = count;
2112
2113 return cnt;
2114}
2115
2116static struct ftrace_page *
2117ftrace_allocate_pages(unsigned long num_to_init)
2118{
2119 struct ftrace_page *start_pg;
2120 struct ftrace_page *pg;
2121 int order;
2122 int cnt;
2123
2124 if (!num_to_init)
2125 return 0;
2126
2127 start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL);
2128 if (!pg)
2129 return NULL;
2130
2131 /*
2132 * Try to allocate as much as possible in one continues
2133 * location that fills in all of the space. We want to
2134 * waste as little space as possible.
2135 */
2136 for (;;) {
2137 cnt = ftrace_allocate_records(pg, num_to_init);
2138 if (cnt < 0)
2139 goto free_pages;
2140
2141 num_to_init -= cnt;
2142 if (!num_to_init)
2143 break;
2144
2145 pg->next = kzalloc(sizeof(*pg), GFP_KERNEL);
2146 if (!pg->next)
2147 goto free_pages;
2148
2149 pg = pg->next;
2150 }
2151
2152 return start_pg;
2153
2154 free_pages:
2155 while (start_pg) {
2156 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
2157 free_pages((unsigned long)pg->records, order);
2158 start_pg = pg->next;
2159 kfree(pg);
2160 pg = start_pg;
2161 }
2162 pr_info("ftrace: FAILED to allocate memory for functions\n");
2163 return NULL;
2164}
2165
2166static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
2167{
2168 int cnt;
2169
2170 if (!num_to_init) {
2171 pr_info("ftrace: No functions to be traced?\n");
2172 return -1;
2173 }
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002174
Steven Rostedt68bf21a2008-08-14 15:45:08 -04002175 cnt = num_to_init / ENTRIES_PER_PAGE;
Steven Rostedt08f5ac902008-10-23 09:33:07 -04002176 pr_info("ftrace: allocating %ld entries in %d pages\n",
walimis5821e1b2008-11-15 15:19:06 +08002177 num_to_init, cnt + 1);
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002178
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002179 return 0;
2180}
2181
Steven Rostedt5072c592008-05-12 21:20:43 +02002182#define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
2183
2184struct ftrace_iterator {
Steven Rostedt98c4fd02010-09-10 11:47:43 -04002185 loff_t pos;
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002186 loff_t func_pos;
2187 struct ftrace_page *pg;
2188 struct dyn_ftrace *func;
2189 struct ftrace_func_probe *probe;
2190 struct trace_parser parser;
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04002191 struct ftrace_hash *hash;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04002192 struct ftrace_ops *ops;
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002193 int hidx;
2194 int idx;
2195 unsigned flags;
Steven Rostedt5072c592008-05-12 21:20:43 +02002196};
2197
Ingo Molnare309b412008-05-12 21:20:51 +02002198static void *
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002199t_hash_next(struct seq_file *m, loff_t *pos)
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002200{
2201 struct ftrace_iterator *iter = m->private;
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002202 struct hlist_node *hnd = NULL;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002203 struct hlist_head *hhd;
2204
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002205 (*pos)++;
Steven Rostedt98c4fd02010-09-10 11:47:43 -04002206 iter->pos = *pos;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002207
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002208 if (iter->probe)
2209 hnd = &iter->probe->node;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002210 retry:
2211 if (iter->hidx >= FTRACE_FUNC_HASHSIZE)
2212 return NULL;
2213
2214 hhd = &ftrace_func_hash[iter->hidx];
2215
2216 if (hlist_empty(hhd)) {
2217 iter->hidx++;
2218 hnd = NULL;
2219 goto retry;
2220 }
2221
2222 if (!hnd)
2223 hnd = hhd->first;
2224 else {
2225 hnd = hnd->next;
2226 if (!hnd) {
2227 iter->hidx++;
2228 goto retry;
2229 }
2230 }
2231
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002232 if (WARN_ON_ONCE(!hnd))
2233 return NULL;
2234
2235 iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node);
2236
2237 return iter;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002238}
2239
2240static void *t_hash_start(struct seq_file *m, loff_t *pos)
2241{
2242 struct ftrace_iterator *iter = m->private;
2243 void *p = NULL;
Li Zefand82d6242009-06-24 09:54:54 +08002244 loff_t l;
2245
Steven Rostedt69a30832011-12-19 15:21:16 -05002246 if (!(iter->flags & FTRACE_ITER_DO_HASH))
2247 return NULL;
2248
Steven Rostedt2bccfff2010-09-09 08:43:22 -04002249 if (iter->func_pos > *pos)
2250 return NULL;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002251
Li Zefand82d6242009-06-24 09:54:54 +08002252 iter->hidx = 0;
Steven Rostedt2bccfff2010-09-09 08:43:22 -04002253 for (l = 0; l <= (*pos - iter->func_pos); ) {
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002254 p = t_hash_next(m, &l);
Li Zefand82d6242009-06-24 09:54:54 +08002255 if (!p)
2256 break;
2257 }
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002258 if (!p)
2259 return NULL;
2260
Steven Rostedt98c4fd02010-09-10 11:47:43 -04002261 /* Only set this if we have an item */
2262 iter->flags |= FTRACE_ITER_HASH;
2263
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002264 return iter;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002265}
2266
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002267static int
2268t_hash_show(struct seq_file *m, struct ftrace_iterator *iter)
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002269{
Steven Rostedtb6887d72009-02-17 12:32:04 -05002270 struct ftrace_func_probe *rec;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002271
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002272 rec = iter->probe;
2273 if (WARN_ON_ONCE(!rec))
2274 return -EIO;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002275
Steven Rostedt809dcf22009-02-16 23:06:01 -05002276 if (rec->ops->print)
2277 return rec->ops->print(m, rec->ip, rec->ops, rec->data);
2278
Steven Rostedtb375a112009-09-17 00:05:58 -04002279 seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func);
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002280
2281 if (rec->data)
2282 seq_printf(m, ":%p", rec->data);
2283 seq_putc(m, '\n');
2284
2285 return 0;
2286}
2287
2288static void *
Steven Rostedt5072c592008-05-12 21:20:43 +02002289t_next(struct seq_file *m, void *v, loff_t *pos)
2290{
2291 struct ftrace_iterator *iter = m->private;
Steven Rostedtfc13cb02011-12-19 14:41:25 -05002292 struct ftrace_ops *ops = iter->ops;
Steven Rostedt5072c592008-05-12 21:20:43 +02002293 struct dyn_ftrace *rec = NULL;
2294
Steven Rostedt45a4a232011-04-21 23:16:46 -04002295 if (unlikely(ftrace_disabled))
2296 return NULL;
2297
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002298 if (iter->flags & FTRACE_ITER_HASH)
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002299 return t_hash_next(m, pos);
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002300
Steven Rostedt5072c592008-05-12 21:20:43 +02002301 (*pos)++;
Jiri Olsa1106b692011-02-16 17:35:34 +01002302 iter->pos = iter->func_pos = *pos;
Steven Rostedt5072c592008-05-12 21:20:43 +02002303
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05002304 if (iter->flags & FTRACE_ITER_PRINTALL)
Steven Rostedt57c072c2010-09-14 11:21:11 -04002305 return t_hash_start(m, pos);
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05002306
Steven Rostedt5072c592008-05-12 21:20:43 +02002307 retry:
2308 if (iter->idx >= iter->pg->index) {
2309 if (iter->pg->next) {
2310 iter->pg = iter->pg->next;
2311 iter->idx = 0;
2312 goto retry;
2313 }
2314 } else {
2315 rec = &iter->pg->records[iter->idx++];
Steven Rostedt32082302011-12-16 14:42:37 -05002316 if (((iter->flags & FTRACE_ITER_FILTER) &&
Steven Rostedtf45948e2011-05-02 12:29:25 -04002317 !(ftrace_lookup_ip(ops->filter_hash, rec->ip))) ||
Steven Rostedt0183fb12008-11-07 22:36:02 -05002318
Steven Rostedt41c52c02008-05-22 11:46:33 -04002319 ((iter->flags & FTRACE_ITER_NOTRACE) &&
Steven Rostedt647bcd02011-05-03 14:39:21 -04002320 !ftrace_lookup_ip(ops->notrace_hash, rec->ip)) ||
2321
2322 ((iter->flags & FTRACE_ITER_ENABLED) &&
2323 !(rec->flags & ~FTRACE_FL_MASK))) {
2324
Steven Rostedt5072c592008-05-12 21:20:43 +02002325 rec = NULL;
2326 goto retry;
2327 }
2328 }
2329
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002330 if (!rec)
Steven Rostedt57c072c2010-09-14 11:21:11 -04002331 return t_hash_start(m, pos);
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002332
2333 iter->func = rec;
2334
2335 return iter;
Steven Rostedt5072c592008-05-12 21:20:43 +02002336}
2337
Steven Rostedt98c4fd02010-09-10 11:47:43 -04002338static void reset_iter_read(struct ftrace_iterator *iter)
2339{
2340 iter->pos = 0;
2341 iter->func_pos = 0;
2342 iter->flags &= ~(FTRACE_ITER_PRINTALL & FTRACE_ITER_HASH);
Steven Rostedt5072c592008-05-12 21:20:43 +02002343}
2344
2345static void *t_start(struct seq_file *m, loff_t *pos)
2346{
2347 struct ftrace_iterator *iter = m->private;
Steven Rostedtfc13cb02011-12-19 14:41:25 -05002348 struct ftrace_ops *ops = iter->ops;
Steven Rostedt5072c592008-05-12 21:20:43 +02002349 void *p = NULL;
Li Zefan694ce0a2009-06-24 09:54:19 +08002350 loff_t l;
Steven Rostedt5072c592008-05-12 21:20:43 +02002351
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002352 mutex_lock(&ftrace_lock);
Steven Rostedt45a4a232011-04-21 23:16:46 -04002353
2354 if (unlikely(ftrace_disabled))
2355 return NULL;
2356
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05002357 /*
Steven Rostedt98c4fd02010-09-10 11:47:43 -04002358 * If an lseek was done, then reset and start from beginning.
2359 */
2360 if (*pos < iter->pos)
2361 reset_iter_read(iter);
2362
2363 /*
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05002364 * For set_ftrace_filter reading, if we have the filter
2365 * off, we can short cut and just print out that all
2366 * functions are enabled.
2367 */
Steven Rostedt06a51d92011-12-19 19:07:36 -05002368 if (iter->flags & FTRACE_ITER_FILTER &&
2369 ftrace_hash_empty(ops->filter_hash)) {
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05002370 if (*pos > 0)
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002371 return t_hash_start(m, pos);
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05002372 iter->flags |= FTRACE_ITER_PRINTALL;
Chris Wrightdf091622010-09-09 16:34:59 -07002373 /* reset in case of seek/pread */
2374 iter->flags &= ~FTRACE_ITER_HASH;
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05002375 return iter;
2376 }
2377
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002378 if (iter->flags & FTRACE_ITER_HASH)
2379 return t_hash_start(m, pos);
2380
Steven Rostedt98c4fd02010-09-10 11:47:43 -04002381 /*
2382 * Unfortunately, we need to restart at ftrace_pages_start
2383 * every time we let go of the ftrace_mutex. This is because
2384 * those pointers can change without the lock.
2385 */
Li Zefan694ce0a2009-06-24 09:54:19 +08002386 iter->pg = ftrace_pages_start;
2387 iter->idx = 0;
2388 for (l = 0; l <= *pos; ) {
2389 p = t_next(m, p, &l);
2390 if (!p)
2391 break;
Liming Wang50cdaf02008-11-28 12:13:21 +08002392 }
walimis5821e1b2008-11-15 15:19:06 +08002393
Steven Rostedt69a30832011-12-19 15:21:16 -05002394 if (!p)
2395 return t_hash_start(m, pos);
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002396
2397 return iter;
Steven Rostedt5072c592008-05-12 21:20:43 +02002398}
2399
2400static void t_stop(struct seq_file *m, void *p)
2401{
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002402 mutex_unlock(&ftrace_lock);
Steven Rostedt5072c592008-05-12 21:20:43 +02002403}
2404
2405static int t_show(struct seq_file *m, void *v)
2406{
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05002407 struct ftrace_iterator *iter = m->private;
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002408 struct dyn_ftrace *rec;
Steven Rostedt5072c592008-05-12 21:20:43 +02002409
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002410 if (iter->flags & FTRACE_ITER_HASH)
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002411 return t_hash_show(m, iter);
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002412
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05002413 if (iter->flags & FTRACE_ITER_PRINTALL) {
2414 seq_printf(m, "#### all functions enabled ####\n");
2415 return 0;
2416 }
2417
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002418 rec = iter->func;
2419
Steven Rostedt5072c592008-05-12 21:20:43 +02002420 if (!rec)
2421 return 0;
2422
Steven Rostedt647bcd02011-05-03 14:39:21 -04002423 seq_printf(m, "%ps", (void *)rec->ip);
2424 if (iter->flags & FTRACE_ITER_ENABLED)
2425 seq_printf(m, " (%ld)",
2426 rec->flags & ~FTRACE_FL_MASK);
2427 seq_printf(m, "\n");
Steven Rostedt5072c592008-05-12 21:20:43 +02002428
2429 return 0;
2430}
2431
James Morris88e9d342009-09-22 16:43:43 -07002432static const struct seq_operations show_ftrace_seq_ops = {
Steven Rostedt5072c592008-05-12 21:20:43 +02002433 .start = t_start,
2434 .next = t_next,
2435 .stop = t_stop,
2436 .show = t_show,
2437};
2438
Ingo Molnare309b412008-05-12 21:20:51 +02002439static int
Steven Rostedt5072c592008-05-12 21:20:43 +02002440ftrace_avail_open(struct inode *inode, struct file *file)
2441{
2442 struct ftrace_iterator *iter;
Steven Rostedt5072c592008-05-12 21:20:43 +02002443
Steven Rostedt4eebcc82008-05-12 21:20:48 +02002444 if (unlikely(ftrace_disabled))
2445 return -ENODEV;
2446
Jiri Olsa50e18b92012-04-25 10:23:39 +02002447 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
2448 if (iter) {
2449 iter->pg = ftrace_pages_start;
2450 iter->ops = &global_ops;
Ingo Molnar4bf39a92008-05-12 21:20:46 +02002451 }
Steven Rostedt5072c592008-05-12 21:20:43 +02002452
Jiri Olsa50e18b92012-04-25 10:23:39 +02002453 return iter ? 0 : -ENOMEM;
Steven Rostedt5072c592008-05-12 21:20:43 +02002454}
2455
Steven Rostedt647bcd02011-05-03 14:39:21 -04002456static int
2457ftrace_enabled_open(struct inode *inode, struct file *file)
2458{
2459 struct ftrace_iterator *iter;
Steven Rostedt647bcd02011-05-03 14:39:21 -04002460
2461 if (unlikely(ftrace_disabled))
2462 return -ENODEV;
2463
Jiri Olsa50e18b92012-04-25 10:23:39 +02002464 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
2465 if (iter) {
2466 iter->pg = ftrace_pages_start;
2467 iter->flags = FTRACE_ITER_ENABLED;
2468 iter->ops = &global_ops;
Steven Rostedt647bcd02011-05-03 14:39:21 -04002469 }
2470
Jiri Olsa50e18b92012-04-25 10:23:39 +02002471 return iter ? 0 : -ENOMEM;
Steven Rostedt647bcd02011-05-03 14:39:21 -04002472}
2473
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04002474static void ftrace_filter_reset(struct ftrace_hash *hash)
Steven Rostedt5072c592008-05-12 21:20:43 +02002475{
Steven Rostedt52baf112009-02-14 01:15:39 -05002476 mutex_lock(&ftrace_lock);
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04002477 ftrace_hash_clear(hash);
Steven Rostedt52baf112009-02-14 01:15:39 -05002478 mutex_unlock(&ftrace_lock);
Steven Rostedt5072c592008-05-12 21:20:43 +02002479}
2480
Steven Rostedtfc13cb02011-12-19 14:41:25 -05002481/**
2482 * ftrace_regex_open - initialize function tracer filter files
2483 * @ops: The ftrace_ops that hold the hash filters
2484 * @flag: The type of filter to process
2485 * @inode: The inode, usually passed in to your open routine
2486 * @file: The file, usually passed in to your open routine
2487 *
2488 * ftrace_regex_open() initializes the filter files for the
2489 * @ops. Depending on @flag it may process the filter hash or
2490 * the notrace hash of @ops. With this called from the open
2491 * routine, you can use ftrace_filter_write() for the write
2492 * routine if @flag has FTRACE_ITER_FILTER set, or
2493 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
2494 * ftrace_regex_lseek() should be used as the lseek routine, and
2495 * release must call ftrace_regex_release().
2496 */
2497int
Steven Rostedtf45948e2011-05-02 12:29:25 -04002498ftrace_regex_open(struct ftrace_ops *ops, int flag,
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04002499 struct inode *inode, struct file *file)
Steven Rostedt5072c592008-05-12 21:20:43 +02002500{
2501 struct ftrace_iterator *iter;
Steven Rostedtf45948e2011-05-02 12:29:25 -04002502 struct ftrace_hash *hash;
Steven Rostedt5072c592008-05-12 21:20:43 +02002503 int ret = 0;
2504
Steven Rostedt4eebcc82008-05-12 21:20:48 +02002505 if (unlikely(ftrace_disabled))
2506 return -ENODEV;
2507
Steven Rostedt5072c592008-05-12 21:20:43 +02002508 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
2509 if (!iter)
2510 return -ENOMEM;
2511
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02002512 if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) {
2513 kfree(iter);
2514 return -ENOMEM;
2515 }
2516
Steven Rostedtf45948e2011-05-02 12:29:25 -04002517 if (flag & FTRACE_ITER_NOTRACE)
2518 hash = ops->notrace_hash;
2519 else
2520 hash = ops->filter_hash;
2521
Steven Rostedt33dc9b12011-05-02 17:34:47 -04002522 iter->ops = ops;
2523 iter->flags = flag;
2524
2525 if (file->f_mode & FMODE_WRITE) {
2526 mutex_lock(&ftrace_lock);
2527 iter->hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash);
2528 mutex_unlock(&ftrace_lock);
2529
2530 if (!iter->hash) {
2531 trace_parser_put(&iter->parser);
2532 kfree(iter);
2533 return -ENOMEM;
2534 }
2535 }
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04002536
Steven Rostedt41c52c02008-05-22 11:46:33 -04002537 mutex_lock(&ftrace_regex_lock);
Steven Rostedt33dc9b12011-05-02 17:34:47 -04002538
Steven Rostedt5072c592008-05-12 21:20:43 +02002539 if ((file->f_mode & FMODE_WRITE) &&
Steven Rostedt8650ae32009-07-22 23:29:30 -04002540 (file->f_flags & O_TRUNC))
Steven Rostedt33dc9b12011-05-02 17:34:47 -04002541 ftrace_filter_reset(iter->hash);
Steven Rostedt5072c592008-05-12 21:20:43 +02002542
2543 if (file->f_mode & FMODE_READ) {
2544 iter->pg = ftrace_pages_start;
Steven Rostedt5072c592008-05-12 21:20:43 +02002545
2546 ret = seq_open(file, &show_ftrace_seq_ops);
2547 if (!ret) {
2548 struct seq_file *m = file->private_data;
2549 m->private = iter;
Li Zefan79fe2492009-09-22 13:54:28 +08002550 } else {
Steven Rostedt33dc9b12011-05-02 17:34:47 -04002551 /* Failed */
2552 free_ftrace_hash(iter->hash);
Li Zefan79fe2492009-09-22 13:54:28 +08002553 trace_parser_put(&iter->parser);
Steven Rostedt5072c592008-05-12 21:20:43 +02002554 kfree(iter);
Li Zefan79fe2492009-09-22 13:54:28 +08002555 }
Steven Rostedt5072c592008-05-12 21:20:43 +02002556 } else
2557 file->private_data = iter;
Steven Rostedt41c52c02008-05-22 11:46:33 -04002558 mutex_unlock(&ftrace_regex_lock);
Steven Rostedt5072c592008-05-12 21:20:43 +02002559
2560 return ret;
2561}
2562
Steven Rostedt41c52c02008-05-22 11:46:33 -04002563static int
2564ftrace_filter_open(struct inode *inode, struct file *file)
2565{
Steven Rostedt69a30832011-12-19 15:21:16 -05002566 return ftrace_regex_open(&global_ops,
2567 FTRACE_ITER_FILTER | FTRACE_ITER_DO_HASH,
2568 inode, file);
Steven Rostedt41c52c02008-05-22 11:46:33 -04002569}
2570
2571static int
2572ftrace_notrace_open(struct inode *inode, struct file *file)
2573{
Steven Rostedtf45948e2011-05-02 12:29:25 -04002574 return ftrace_regex_open(&global_ops, FTRACE_ITER_NOTRACE,
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04002575 inode, file);
Steven Rostedt41c52c02008-05-22 11:46:33 -04002576}
2577
Steven Rostedtfc13cb02011-12-19 14:41:25 -05002578loff_t
Steven Rostedt41c52c02008-05-22 11:46:33 -04002579ftrace_regex_lseek(struct file *file, loff_t offset, int origin)
Steven Rostedt5072c592008-05-12 21:20:43 +02002580{
2581 loff_t ret;
2582
2583 if (file->f_mode & FMODE_READ)
2584 ret = seq_lseek(file, offset, origin);
2585 else
2586 file->f_pos = ret = 1;
2587
2588 return ret;
2589}
2590
Steven Rostedt64e7c442009-02-13 17:08:48 -05002591static int ftrace_match(char *str, char *regex, int len, int type)
Steven Rostedt9f4801e2009-02-13 15:56:43 -05002592{
Steven Rostedt9f4801e2009-02-13 15:56:43 -05002593 int matched = 0;
Li Zefan751e9982010-01-14 10:53:02 +08002594 int slen;
Steven Rostedt9f4801e2009-02-13 15:56:43 -05002595
Steven Rostedt9f4801e2009-02-13 15:56:43 -05002596 switch (type) {
2597 case MATCH_FULL:
2598 if (strcmp(str, regex) == 0)
2599 matched = 1;
2600 break;
2601 case MATCH_FRONT_ONLY:
2602 if (strncmp(str, regex, len) == 0)
2603 matched = 1;
2604 break;
2605 case MATCH_MIDDLE_ONLY:
2606 if (strstr(str, regex))
2607 matched = 1;
2608 break;
2609 case MATCH_END_ONLY:
Li Zefan751e9982010-01-14 10:53:02 +08002610 slen = strlen(str);
2611 if (slen >= len && memcmp(str + slen - len, regex, len) == 0)
Steven Rostedt9f4801e2009-02-13 15:56:43 -05002612 matched = 1;
2613 break;
2614 }
2615
2616 return matched;
2617}
2618
Steven Rostedtb448c4e2011-04-29 15:12:32 -04002619static int
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04002620enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not)
Steven Rostedt996e87b2011-04-26 16:11:03 -04002621{
Steven Rostedtb448c4e2011-04-29 15:12:32 -04002622 struct ftrace_func_entry *entry;
Steven Rostedtb448c4e2011-04-29 15:12:32 -04002623 int ret = 0;
2624
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04002625 entry = ftrace_lookup_ip(hash, rec->ip);
2626 if (not) {
2627 /* Do nothing if it doesn't exist */
2628 if (!entry)
2629 return 0;
2630
Steven Rostedt33dc9b12011-05-02 17:34:47 -04002631 free_hash_entry(hash, entry);
Steven Rostedtb448c4e2011-04-29 15:12:32 -04002632 } else {
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04002633 /* Do nothing if it exists */
2634 if (entry)
2635 return 0;
Steven Rostedtb448c4e2011-04-29 15:12:32 -04002636
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04002637 ret = add_hash_entry(hash, rec->ip);
Steven Rostedtb448c4e2011-04-29 15:12:32 -04002638 }
2639 return ret;
Steven Rostedt996e87b2011-04-26 16:11:03 -04002640}
2641
Steven Rostedt64e7c442009-02-13 17:08:48 -05002642static int
Steven Rostedtb9df92d2011-04-28 20:32:08 -04002643ftrace_match_record(struct dyn_ftrace *rec, char *mod,
2644 char *regex, int len, int type)
Steven Rostedt64e7c442009-02-13 17:08:48 -05002645{
2646 char str[KSYM_SYMBOL_LEN];
Steven Rostedtb9df92d2011-04-28 20:32:08 -04002647 char *modname;
Steven Rostedt64e7c442009-02-13 17:08:48 -05002648
Steven Rostedtb9df92d2011-04-28 20:32:08 -04002649 kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
2650
2651 if (mod) {
2652 /* module lookup requires matching the module */
2653 if (!modname || strcmp(modname, mod))
2654 return 0;
2655
2656 /* blank search means to match all funcs in the mod */
2657 if (!len)
2658 return 1;
2659 }
2660
Steven Rostedt64e7c442009-02-13 17:08:48 -05002661 return ftrace_match(str, regex, len, type);
2662}
2663
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04002664static int
2665match_records(struct ftrace_hash *hash, char *buff,
2666 int len, char *mod, int not)
Steven Rostedt9f4801e2009-02-13 15:56:43 -05002667{
Steven Rostedtb9df92d2011-04-28 20:32:08 -04002668 unsigned search_len = 0;
Steven Rostedt9f4801e2009-02-13 15:56:43 -05002669 struct ftrace_page *pg;
2670 struct dyn_ftrace *rec;
Steven Rostedtb9df92d2011-04-28 20:32:08 -04002671 int type = MATCH_FULL;
2672 char *search = buff;
Li Zefan311d16d2009-12-08 11:15:11 +08002673 int found = 0;
Steven Rostedtb448c4e2011-04-29 15:12:32 -04002674 int ret;
Steven Rostedt9f4801e2009-02-13 15:56:43 -05002675
Steven Rostedtb9df92d2011-04-28 20:32:08 -04002676 if (len) {
2677 type = filter_parse_regex(buff, len, &search, &not);
2678 search_len = strlen(search);
2679 }
Steven Rostedt9f4801e2009-02-13 15:56:43 -05002680
Steven Rostedt52baf112009-02-14 01:15:39 -05002681 mutex_lock(&ftrace_lock);
Steven Rostedtb9df92d2011-04-28 20:32:08 -04002682
2683 if (unlikely(ftrace_disabled))
2684 goto out_unlock;
2685
Steven Rostedt265c8312009-02-13 12:43:56 -05002686 do_for_each_ftrace_rec(pg, rec) {
Steven Rostedtb9df92d2011-04-28 20:32:08 -04002687 if (ftrace_match_record(rec, mod, search, search_len, type)) {
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04002688 ret = enter_record(hash, rec, not);
Steven Rostedtb448c4e2011-04-29 15:12:32 -04002689 if (ret < 0) {
2690 found = ret;
2691 goto out_unlock;
2692 }
Li Zefan311d16d2009-12-08 11:15:11 +08002693 found = 1;
Steven Rostedt265c8312009-02-13 12:43:56 -05002694 }
2695 } while_for_each_ftrace_rec();
Steven Rostedtb9df92d2011-04-28 20:32:08 -04002696 out_unlock:
Steven Rostedt52baf112009-02-14 01:15:39 -05002697 mutex_unlock(&ftrace_lock);
Li Zefan311d16d2009-12-08 11:15:11 +08002698
2699 return found;
Steven Rostedt5072c592008-05-12 21:20:43 +02002700}
2701
Steven Rostedt64e7c442009-02-13 17:08:48 -05002702static int
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04002703ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
Steven Rostedt64e7c442009-02-13 17:08:48 -05002704{
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04002705 return match_records(hash, buff, len, NULL, 0);
Steven Rostedt64e7c442009-02-13 17:08:48 -05002706}
2707
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04002708static int
2709ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod)
Steven Rostedt64e7c442009-02-13 17:08:48 -05002710{
Steven Rostedt64e7c442009-02-13 17:08:48 -05002711 int not = 0;
Steven Rostedt6a24a242009-02-17 11:20:26 -05002712
Steven Rostedt64e7c442009-02-13 17:08:48 -05002713 /* blank or '*' mean the same */
2714 if (strcmp(buff, "*") == 0)
2715 buff[0] = 0;
2716
2717 /* handle the case of 'dont filter this module' */
2718 if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) {
2719 buff[0] = 0;
2720 not = 1;
2721 }
2722
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04002723 return match_records(hash, buff, strlen(buff), mod, not);
Steven Rostedt64e7c442009-02-13 17:08:48 -05002724}
2725
Steven Rostedtf6180772009-02-14 00:40:25 -05002726/*
2727 * We register the module command as a template to show others how
2728 * to register the a command as well.
2729 */
2730
2731static int
Steven Rostedt43dd61c2011-07-07 11:09:22 -04002732ftrace_mod_callback(struct ftrace_hash *hash,
2733 char *func, char *cmd, char *param, int enable)
Steven Rostedtf6180772009-02-14 00:40:25 -05002734{
2735 char *mod;
Steven Rostedtb448c4e2011-04-29 15:12:32 -04002736 int ret = -EINVAL;
Steven Rostedtf6180772009-02-14 00:40:25 -05002737
2738 /*
2739 * cmd == 'mod' because we only registered this func
2740 * for the 'mod' ftrace_func_command.
2741 * But if you register one func with multiple commands,
2742 * you can tell which command was used by the cmd
2743 * parameter.
2744 */
2745
2746 /* we must have a module name */
2747 if (!param)
Steven Rostedtb448c4e2011-04-29 15:12:32 -04002748 return ret;
Steven Rostedtf6180772009-02-14 00:40:25 -05002749
2750 mod = strsep(&param, ":");
2751 if (!strlen(mod))
Steven Rostedtb448c4e2011-04-29 15:12:32 -04002752 return ret;
Steven Rostedtf6180772009-02-14 00:40:25 -05002753
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04002754 ret = ftrace_match_module_records(hash, func, mod);
Steven Rostedtb448c4e2011-04-29 15:12:32 -04002755 if (!ret)
2756 ret = -EINVAL;
2757 if (ret < 0)
2758 return ret;
2759
2760 return 0;
Steven Rostedtf6180772009-02-14 00:40:25 -05002761}
2762
2763static struct ftrace_func_command ftrace_mod_cmd = {
2764 .name = "mod",
2765 .func = ftrace_mod_callback,
2766};
2767
2768static int __init ftrace_mod_cmd_init(void)
2769{
2770 return register_ftrace_command(&ftrace_mod_cmd);
2771}
2772device_initcall(ftrace_mod_cmd_init);
2773
Steven Rostedt59df055f2009-02-14 15:29:06 -05002774static void
Steven Rostedtb6887d72009-02-17 12:32:04 -05002775function_trace_probe_call(unsigned long ip, unsigned long parent_ip)
Steven Rostedt59df055f2009-02-14 15:29:06 -05002776{
Steven Rostedtb6887d72009-02-17 12:32:04 -05002777 struct ftrace_func_probe *entry;
Steven Rostedt59df055f2009-02-14 15:29:06 -05002778 struct hlist_head *hhd;
2779 struct hlist_node *n;
2780 unsigned long key;
Steven Rostedt59df055f2009-02-14 15:29:06 -05002781
2782 key = hash_long(ip, FTRACE_HASH_BITS);
2783
2784 hhd = &ftrace_func_hash[key];
2785
2786 if (hlist_empty(hhd))
2787 return;
2788
2789 /*
2790 * Disable preemption for these calls to prevent a RCU grace
2791 * period. This syncs the hash iteration and freeing of items
2792 * on the hash. rcu_read_lock is too dangerous here.
2793 */
Steven Rostedt5168ae52010-06-03 09:36:50 -04002794 preempt_disable_notrace();
Steven Rostedt59df055f2009-02-14 15:29:06 -05002795 hlist_for_each_entry_rcu(entry, n, hhd, node) {
2796 if (entry->ip == ip)
2797 entry->ops->func(ip, parent_ip, &entry->data);
2798 }
Steven Rostedt5168ae52010-06-03 09:36:50 -04002799 preempt_enable_notrace();
Steven Rostedt59df055f2009-02-14 15:29:06 -05002800}
2801
Steven Rostedtb6887d72009-02-17 12:32:04 -05002802static struct ftrace_ops trace_probe_ops __read_mostly =
Steven Rostedt59df055f2009-02-14 15:29:06 -05002803{
Steven Rostedtfb9fb012009-03-25 13:26:41 -04002804 .func = function_trace_probe_call,
Steven Rostedt59df055f2009-02-14 15:29:06 -05002805};
2806
Steven Rostedtb6887d72009-02-17 12:32:04 -05002807static int ftrace_probe_registered;
Steven Rostedt59df055f2009-02-14 15:29:06 -05002808
Steven Rostedtb6887d72009-02-17 12:32:04 -05002809static void __enable_ftrace_function_probe(void)
Steven Rostedt59df055f2009-02-14 15:29:06 -05002810{
Steven Rostedtb8489142011-05-04 09:27:52 -04002811 int ret;
Steven Rostedt59df055f2009-02-14 15:29:06 -05002812 int i;
2813
Steven Rostedtb6887d72009-02-17 12:32:04 -05002814 if (ftrace_probe_registered)
Steven Rostedt59df055f2009-02-14 15:29:06 -05002815 return;
2816
2817 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
2818 struct hlist_head *hhd = &ftrace_func_hash[i];
2819 if (hhd->first)
2820 break;
2821 }
2822 /* Nothing registered? */
2823 if (i == FTRACE_FUNC_HASHSIZE)
2824 return;
2825
Steven Rostedtb8489142011-05-04 09:27:52 -04002826 ret = __register_ftrace_function(&trace_probe_ops);
2827 if (!ret)
Steven Rostedta1cd6172011-05-23 15:24:25 -04002828 ret = ftrace_startup(&trace_probe_ops, 0);
Steven Rostedtb8489142011-05-04 09:27:52 -04002829
Steven Rostedtb6887d72009-02-17 12:32:04 -05002830 ftrace_probe_registered = 1;
Steven Rostedt59df055f2009-02-14 15:29:06 -05002831}
2832
Steven Rostedtb6887d72009-02-17 12:32:04 -05002833static void __disable_ftrace_function_probe(void)
Steven Rostedt59df055f2009-02-14 15:29:06 -05002834{
Steven Rostedtb8489142011-05-04 09:27:52 -04002835 int ret;
Steven Rostedt59df055f2009-02-14 15:29:06 -05002836 int i;
2837
Steven Rostedtb6887d72009-02-17 12:32:04 -05002838 if (!ftrace_probe_registered)
Steven Rostedt59df055f2009-02-14 15:29:06 -05002839 return;
2840
2841 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
2842 struct hlist_head *hhd = &ftrace_func_hash[i];
2843 if (hhd->first)
2844 return;
2845 }
2846
2847 /* no more funcs left */
Steven Rostedtb8489142011-05-04 09:27:52 -04002848 ret = __unregister_ftrace_function(&trace_probe_ops);
2849 if (!ret)
2850 ftrace_shutdown(&trace_probe_ops, 0);
2851
Steven Rostedtb6887d72009-02-17 12:32:04 -05002852 ftrace_probe_registered = 0;
Steven Rostedt59df055f2009-02-14 15:29:06 -05002853}
2854
2855
2856static void ftrace_free_entry_rcu(struct rcu_head *rhp)
2857{
Steven Rostedtb6887d72009-02-17 12:32:04 -05002858 struct ftrace_func_probe *entry =
2859 container_of(rhp, struct ftrace_func_probe, rcu);
Steven Rostedt59df055f2009-02-14 15:29:06 -05002860
2861 if (entry->ops->free)
2862 entry->ops->free(&entry->data);
2863 kfree(entry);
2864}
2865
2866
2867int
Steven Rostedtb6887d72009-02-17 12:32:04 -05002868register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
Steven Rostedt59df055f2009-02-14 15:29:06 -05002869 void *data)
2870{
Steven Rostedtb6887d72009-02-17 12:32:04 -05002871 struct ftrace_func_probe *entry;
Steven Rostedt59df055f2009-02-14 15:29:06 -05002872 struct ftrace_page *pg;
2873 struct dyn_ftrace *rec;
Steven Rostedt59df055f2009-02-14 15:29:06 -05002874 int type, len, not;
Steven Rostedt6a24a242009-02-17 11:20:26 -05002875 unsigned long key;
Steven Rostedt59df055f2009-02-14 15:29:06 -05002876 int count = 0;
2877 char *search;
2878
Frederic Weisbecker3f6fe062009-09-24 21:31:51 +02002879 type = filter_parse_regex(glob, strlen(glob), &search, &not);
Steven Rostedt59df055f2009-02-14 15:29:06 -05002880 len = strlen(search);
2881
Steven Rostedtb6887d72009-02-17 12:32:04 -05002882 /* we do not support '!' for function probes */
Steven Rostedt59df055f2009-02-14 15:29:06 -05002883 if (WARN_ON(not))
2884 return -EINVAL;
2885
2886 mutex_lock(&ftrace_lock);
Steven Rostedt59df055f2009-02-14 15:29:06 -05002887
Steven Rostedt45a4a232011-04-21 23:16:46 -04002888 if (unlikely(ftrace_disabled))
2889 goto out_unlock;
2890
Steven Rostedt59df055f2009-02-14 15:29:06 -05002891 do_for_each_ftrace_rec(pg, rec) {
2892
Steven Rostedtb9df92d2011-04-28 20:32:08 -04002893 if (!ftrace_match_record(rec, NULL, search, len, type))
Steven Rostedt59df055f2009-02-14 15:29:06 -05002894 continue;
2895
2896 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
2897 if (!entry) {
Steven Rostedtb6887d72009-02-17 12:32:04 -05002898 /* If we did not process any, then return error */
Steven Rostedt59df055f2009-02-14 15:29:06 -05002899 if (!count)
2900 count = -ENOMEM;
2901 goto out_unlock;
2902 }
2903
2904 count++;
2905
2906 entry->data = data;
2907
2908 /*
2909 * The caller might want to do something special
2910 * for each function we find. We call the callback
2911 * to give the caller an opportunity to do so.
2912 */
2913 if (ops->callback) {
2914 if (ops->callback(rec->ip, &entry->data) < 0) {
2915 /* caller does not like this func */
2916 kfree(entry);
2917 continue;
2918 }
2919 }
2920
2921 entry->ops = ops;
2922 entry->ip = rec->ip;
2923
2924 key = hash_long(entry->ip, FTRACE_HASH_BITS);
2925 hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]);
2926
2927 } while_for_each_ftrace_rec();
Steven Rostedtb6887d72009-02-17 12:32:04 -05002928 __enable_ftrace_function_probe();
Steven Rostedt59df055f2009-02-14 15:29:06 -05002929
2930 out_unlock:
2931 mutex_unlock(&ftrace_lock);
2932
2933 return count;
2934}
2935
2936enum {
Steven Rostedtb6887d72009-02-17 12:32:04 -05002937 PROBE_TEST_FUNC = 1,
2938 PROBE_TEST_DATA = 2
Steven Rostedt59df055f2009-02-14 15:29:06 -05002939};
2940
2941static void
Steven Rostedtb6887d72009-02-17 12:32:04 -05002942__unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
Steven Rostedt59df055f2009-02-14 15:29:06 -05002943 void *data, int flags)
2944{
Steven Rostedtb6887d72009-02-17 12:32:04 -05002945 struct ftrace_func_probe *entry;
Steven Rostedt59df055f2009-02-14 15:29:06 -05002946 struct hlist_node *n, *tmp;
2947 char str[KSYM_SYMBOL_LEN];
2948 int type = MATCH_FULL;
2949 int i, len = 0;
2950 char *search;
2951
Atsushi Tsujib36461d2009-09-15 19:06:30 +09002952 if (glob && (strcmp(glob, "*") == 0 || !strlen(glob)))
Steven Rostedt59df055f2009-02-14 15:29:06 -05002953 glob = NULL;
Atsushi Tsujib36461d2009-09-15 19:06:30 +09002954 else if (glob) {
Steven Rostedt59df055f2009-02-14 15:29:06 -05002955 int not;
2956
Frederic Weisbecker3f6fe062009-09-24 21:31:51 +02002957 type = filter_parse_regex(glob, strlen(glob), &search, &not);
Steven Rostedt59df055f2009-02-14 15:29:06 -05002958 len = strlen(search);
2959
Steven Rostedtb6887d72009-02-17 12:32:04 -05002960 /* we do not support '!' for function probes */
Steven Rostedt59df055f2009-02-14 15:29:06 -05002961 if (WARN_ON(not))
2962 return;
2963 }
2964
2965 mutex_lock(&ftrace_lock);
2966 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
2967 struct hlist_head *hhd = &ftrace_func_hash[i];
2968
2969 hlist_for_each_entry_safe(entry, n, tmp, hhd, node) {
2970
2971 /* break up if statements for readability */
Steven Rostedtb6887d72009-02-17 12:32:04 -05002972 if ((flags & PROBE_TEST_FUNC) && entry->ops != ops)
Steven Rostedt59df055f2009-02-14 15:29:06 -05002973 continue;
2974
Steven Rostedtb6887d72009-02-17 12:32:04 -05002975 if ((flags & PROBE_TEST_DATA) && entry->data != data)
Steven Rostedt59df055f2009-02-14 15:29:06 -05002976 continue;
2977
2978 /* do this last, since it is the most expensive */
2979 if (glob) {
2980 kallsyms_lookup(entry->ip, NULL, NULL,
2981 NULL, str);
2982 if (!ftrace_match(str, glob, len, type))
2983 continue;
2984 }
2985
2986 hlist_del(&entry->node);
2987 call_rcu(&entry->rcu, ftrace_free_entry_rcu);
2988 }
2989 }
Steven Rostedtb6887d72009-02-17 12:32:04 -05002990 __disable_ftrace_function_probe();
Steven Rostedt59df055f2009-02-14 15:29:06 -05002991 mutex_unlock(&ftrace_lock);
2992}
2993
2994void
Steven Rostedtb6887d72009-02-17 12:32:04 -05002995unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
Steven Rostedt59df055f2009-02-14 15:29:06 -05002996 void *data)
2997{
Steven Rostedtb6887d72009-02-17 12:32:04 -05002998 __unregister_ftrace_function_probe(glob, ops, data,
2999 PROBE_TEST_FUNC | PROBE_TEST_DATA);
Steven Rostedt59df055f2009-02-14 15:29:06 -05003000}
3001
3002void
Steven Rostedtb6887d72009-02-17 12:32:04 -05003003unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
Steven Rostedt59df055f2009-02-14 15:29:06 -05003004{
Steven Rostedtb6887d72009-02-17 12:32:04 -05003005 __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC);
Steven Rostedt59df055f2009-02-14 15:29:06 -05003006}
3007
Steven Rostedtb6887d72009-02-17 12:32:04 -05003008void unregister_ftrace_function_probe_all(char *glob)
Steven Rostedt59df055f2009-02-14 15:29:06 -05003009{
Steven Rostedtb6887d72009-02-17 12:32:04 -05003010 __unregister_ftrace_function_probe(glob, NULL, NULL, 0);
Steven Rostedt59df055f2009-02-14 15:29:06 -05003011}
3012
Steven Rostedtf6180772009-02-14 00:40:25 -05003013static LIST_HEAD(ftrace_commands);
3014static DEFINE_MUTEX(ftrace_cmd_mutex);
3015
3016int register_ftrace_command(struct ftrace_func_command *cmd)
3017{
3018 struct ftrace_func_command *p;
3019 int ret = 0;
3020
3021 mutex_lock(&ftrace_cmd_mutex);
3022 list_for_each_entry(p, &ftrace_commands, list) {
3023 if (strcmp(cmd->name, p->name) == 0) {
3024 ret = -EBUSY;
3025 goto out_unlock;
3026 }
3027 }
3028 list_add(&cmd->list, &ftrace_commands);
3029 out_unlock:
3030 mutex_unlock(&ftrace_cmd_mutex);
3031
3032 return ret;
3033}
3034
3035int unregister_ftrace_command(struct ftrace_func_command *cmd)
3036{
3037 struct ftrace_func_command *p, *n;
3038 int ret = -ENODEV;
3039
3040 mutex_lock(&ftrace_cmd_mutex);
3041 list_for_each_entry_safe(p, n, &ftrace_commands, list) {
3042 if (strcmp(cmd->name, p->name) == 0) {
3043 ret = 0;
3044 list_del_init(&p->list);
3045 goto out_unlock;
3046 }
3047 }
3048 out_unlock:
3049 mutex_unlock(&ftrace_cmd_mutex);
3050
3051 return ret;
3052}
3053
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003054static int ftrace_process_regex(struct ftrace_hash *hash,
3055 char *buff, int len, int enable)
Steven Rostedt64e7c442009-02-13 17:08:48 -05003056{
Steven Rostedtf6180772009-02-14 00:40:25 -05003057 char *func, *command, *next = buff;
Steven Rostedt6a24a242009-02-17 11:20:26 -05003058 struct ftrace_func_command *p;
GuoWen Li0aff1c02011-06-01 19:18:47 +08003059 int ret = -EINVAL;
Steven Rostedt64e7c442009-02-13 17:08:48 -05003060
3061 func = strsep(&next, ":");
3062
3063 if (!next) {
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003064 ret = ftrace_match_records(hash, func, len);
Steven Rostedtb448c4e2011-04-29 15:12:32 -04003065 if (!ret)
3066 ret = -EINVAL;
3067 if (ret < 0)
3068 return ret;
3069 return 0;
Steven Rostedt64e7c442009-02-13 17:08:48 -05003070 }
3071
Steven Rostedtf6180772009-02-14 00:40:25 -05003072 /* command found */
Steven Rostedt64e7c442009-02-13 17:08:48 -05003073
3074 command = strsep(&next, ":");
3075
Steven Rostedtf6180772009-02-14 00:40:25 -05003076 mutex_lock(&ftrace_cmd_mutex);
3077 list_for_each_entry(p, &ftrace_commands, list) {
3078 if (strcmp(p->name, command) == 0) {
Steven Rostedt43dd61c2011-07-07 11:09:22 -04003079 ret = p->func(hash, func, command, next, enable);
Steven Rostedtf6180772009-02-14 00:40:25 -05003080 goto out_unlock;
3081 }
Steven Rostedt64e7c442009-02-13 17:08:48 -05003082 }
Steven Rostedtf6180772009-02-14 00:40:25 -05003083 out_unlock:
3084 mutex_unlock(&ftrace_cmd_mutex);
Steven Rostedt64e7c442009-02-13 17:08:48 -05003085
Steven Rostedtf6180772009-02-14 00:40:25 -05003086 return ret;
Steven Rostedt64e7c442009-02-13 17:08:48 -05003087}
3088
Ingo Molnare309b412008-05-12 21:20:51 +02003089static ssize_t
Steven Rostedt41c52c02008-05-22 11:46:33 -04003090ftrace_regex_write(struct file *file, const char __user *ubuf,
3091 size_t cnt, loff_t *ppos, int enable)
Steven Rostedt5072c592008-05-12 21:20:43 +02003092{
3093 struct ftrace_iterator *iter;
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02003094 struct trace_parser *parser;
3095 ssize_t ret, read;
Steven Rostedt5072c592008-05-12 21:20:43 +02003096
Li Zefan4ba79782009-09-22 13:52:20 +08003097 if (!cnt)
Steven Rostedt5072c592008-05-12 21:20:43 +02003098 return 0;
3099
Steven Rostedt41c52c02008-05-22 11:46:33 -04003100 mutex_lock(&ftrace_regex_lock);
Steven Rostedt5072c592008-05-12 21:20:43 +02003101
Steven Rostedt45a4a232011-04-21 23:16:46 -04003102 ret = -ENODEV;
3103 if (unlikely(ftrace_disabled))
3104 goto out_unlock;
3105
Steven Rostedt5072c592008-05-12 21:20:43 +02003106 if (file->f_mode & FMODE_READ) {
3107 struct seq_file *m = file->private_data;
3108 iter = m->private;
3109 } else
3110 iter = file->private_data;
3111
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02003112 parser = &iter->parser;
3113 read = trace_get_user(parser, ubuf, cnt, ppos);
Steven Rostedt5072c592008-05-12 21:20:43 +02003114
Li Zefan4ba79782009-09-22 13:52:20 +08003115 if (read >= 0 && trace_parser_loaded(parser) &&
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02003116 !trace_parser_cont(parser)) {
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003117 ret = ftrace_process_regex(iter->hash, parser->buffer,
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02003118 parser->idx, enable);
Li Zefan313254a2009-12-08 11:15:30 +08003119 trace_parser_clear(parser);
Steven Rostedt5072c592008-05-12 21:20:43 +02003120 if (ret)
Li Zefaned146b252009-11-03 08:55:38 +08003121 goto out_unlock;
Steven Rostedt5072c592008-05-12 21:20:43 +02003122 }
3123
Steven Rostedt5072c592008-05-12 21:20:43 +02003124 ret = read;
Li Zefaned146b252009-11-03 08:55:38 +08003125out_unlock:
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02003126 mutex_unlock(&ftrace_regex_lock);
Li Zefaned146b252009-11-03 08:55:38 +08003127
Steven Rostedt5072c592008-05-12 21:20:43 +02003128 return ret;
3129}
3130
Steven Rostedtfc13cb02011-12-19 14:41:25 -05003131ssize_t
Steven Rostedt41c52c02008-05-22 11:46:33 -04003132ftrace_filter_write(struct file *file, const char __user *ubuf,
3133 size_t cnt, loff_t *ppos)
3134{
3135 return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
3136}
3137
Steven Rostedtfc13cb02011-12-19 14:41:25 -05003138ssize_t
Steven Rostedt41c52c02008-05-22 11:46:33 -04003139ftrace_notrace_write(struct file *file, const char __user *ubuf,
3140 size_t cnt, loff_t *ppos)
3141{
3142 return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
3143}
3144
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003145static int
Steven Rostedtf45948e2011-05-02 12:29:25 -04003146ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
3147 int reset, int enable)
Steven Rostedt41c52c02008-05-22 11:46:33 -04003148{
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003149 struct ftrace_hash **orig_hash;
Steven Rostedtf45948e2011-05-02 12:29:25 -04003150 struct ftrace_hash *hash;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003151 int ret;
Steven Rostedtf45948e2011-05-02 12:29:25 -04003152
Steven Rostedt936e0742011-05-05 22:54:01 -04003153 /* All global ops uses the global ops filters */
3154 if (ops->flags & FTRACE_OPS_FL_GLOBAL)
3155 ops = &global_ops;
3156
Steven Rostedt41c52c02008-05-22 11:46:33 -04003157 if (unlikely(ftrace_disabled))
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003158 return -ENODEV;
Steven Rostedt41c52c02008-05-22 11:46:33 -04003159
Steven Rostedtf45948e2011-05-02 12:29:25 -04003160 if (enable)
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003161 orig_hash = &ops->filter_hash;
Steven Rostedtf45948e2011-05-02 12:29:25 -04003162 else
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003163 orig_hash = &ops->notrace_hash;
3164
3165 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
3166 if (!hash)
3167 return -ENOMEM;
Steven Rostedtf45948e2011-05-02 12:29:25 -04003168
Steven Rostedt41c52c02008-05-22 11:46:33 -04003169 mutex_lock(&ftrace_regex_lock);
3170 if (reset)
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003171 ftrace_filter_reset(hash);
Jiri Olsaac483c42012-01-02 10:04:14 +01003172 if (buf && !ftrace_match_records(hash, buf, len)) {
3173 ret = -EINVAL;
3174 goto out_regex_unlock;
3175 }
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003176
3177 mutex_lock(&ftrace_lock);
Steven Rostedt41fb61c2011-07-13 15:03:44 -04003178 ret = ftrace_hash_move(ops, enable, orig_hash, hash);
Steven Rostedt072126f2011-07-13 15:08:31 -04003179 if (!ret && ops->flags & FTRACE_OPS_FL_ENABLED
3180 && ftrace_enabled)
Jiri Olsa30fb6aa2011-12-05 18:22:48 +01003181 ftrace_run_update_code(FTRACE_UPDATE_CALLS);
Steven Rostedt072126f2011-07-13 15:08:31 -04003182
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003183 mutex_unlock(&ftrace_lock);
3184
Jiri Olsaac483c42012-01-02 10:04:14 +01003185 out_regex_unlock:
Steven Rostedt41c52c02008-05-22 11:46:33 -04003186 mutex_unlock(&ftrace_regex_lock);
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003187
3188 free_ftrace_hash(hash);
3189 return ret;
Steven Rostedt41c52c02008-05-22 11:46:33 -04003190}
3191
Steven Rostedt77a2b372008-05-12 21:20:45 +02003192/**
3193 * ftrace_set_filter - set a function to filter on in ftrace
Steven Rostedt936e0742011-05-05 22:54:01 -04003194 * @ops - the ops to set the filter with
Steven Rostedt77a2b372008-05-12 21:20:45 +02003195 * @buf - the string that holds the function filter text.
3196 * @len - the length of the string.
3197 * @reset - non zero to reset all filters before applying this filter.
3198 *
3199 * Filters denote which functions should be enabled when tracing is enabled.
3200 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
3201 */
Jiri Olsaac483c42012-01-02 10:04:14 +01003202int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
Steven Rostedt936e0742011-05-05 22:54:01 -04003203 int len, int reset)
Steven Rostedt77a2b372008-05-12 21:20:45 +02003204{
Jiri Olsaac483c42012-01-02 10:04:14 +01003205 return ftrace_set_regex(ops, buf, len, reset, 1);
Steven Rostedt41c52c02008-05-22 11:46:33 -04003206}
Steven Rostedt936e0742011-05-05 22:54:01 -04003207EXPORT_SYMBOL_GPL(ftrace_set_filter);
Steven Rostedt4eebcc82008-05-12 21:20:48 +02003208
Steven Rostedt41c52c02008-05-22 11:46:33 -04003209/**
3210 * ftrace_set_notrace - set a function to not trace in ftrace
Steven Rostedt936e0742011-05-05 22:54:01 -04003211 * @ops - the ops to set the notrace filter with
Steven Rostedt41c52c02008-05-22 11:46:33 -04003212 * @buf - the string that holds the function notrace text.
3213 * @len - the length of the string.
3214 * @reset - non zero to reset all filters before applying this filter.
3215 *
3216 * Notrace Filters denote which functions should not be enabled when tracing
3217 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
3218 * for tracing.
3219 */
Jiri Olsaac483c42012-01-02 10:04:14 +01003220int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
Steven Rostedt936e0742011-05-05 22:54:01 -04003221 int len, int reset)
3222{
Jiri Olsaac483c42012-01-02 10:04:14 +01003223 return ftrace_set_regex(ops, buf, len, reset, 0);
Steven Rostedt936e0742011-05-05 22:54:01 -04003224}
3225EXPORT_SYMBOL_GPL(ftrace_set_notrace);
3226/**
3227 * ftrace_set_filter - set a function to filter on in ftrace
3228 * @ops - the ops to set the filter with
3229 * @buf - the string that holds the function filter text.
3230 * @len - the length of the string.
3231 * @reset - non zero to reset all filters before applying this filter.
3232 *
3233 * Filters denote which functions should be enabled when tracing is enabled.
3234 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
3235 */
3236void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
3237{
3238 ftrace_set_regex(&global_ops, buf, len, reset, 1);
3239}
3240EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
3241
3242/**
3243 * ftrace_set_notrace - set a function to not trace in ftrace
3244 * @ops - the ops to set the notrace filter with
3245 * @buf - the string that holds the function notrace text.
3246 * @len - the length of the string.
3247 * @reset - non zero to reset all filters before applying this filter.
3248 *
3249 * Notrace Filters denote which functions should not be enabled when tracing
3250 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
3251 * for tracing.
3252 */
3253void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
Steven Rostedt41c52c02008-05-22 11:46:33 -04003254{
Steven Rostedtf45948e2011-05-02 12:29:25 -04003255 ftrace_set_regex(&global_ops, buf, len, reset, 0);
Steven Rostedt77a2b372008-05-12 21:20:45 +02003256}
Steven Rostedt936e0742011-05-05 22:54:01 -04003257EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
Steven Rostedt77a2b372008-05-12 21:20:45 +02003258
Steven Rostedt2af15d62009-05-28 13:37:24 -04003259/*
3260 * command line interface to allow users to set filters on boot up.
3261 */
3262#define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
3263static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
3264static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
3265
3266static int __init set_ftrace_notrace(char *str)
3267{
3268 strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
3269 return 1;
3270}
3271__setup("ftrace_notrace=", set_ftrace_notrace);
3272
3273static int __init set_ftrace_filter(char *str)
3274{
3275 strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
3276 return 1;
3277}
3278__setup("ftrace_filter=", set_ftrace_filter);
3279
Stefan Assmann369bc182009-10-12 22:17:21 +02003280#ifdef CONFIG_FUNCTION_GRAPH_TRACER
Lai Jiangshanf6060f42009-11-05 11:16:17 +08003281static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
Steven Rostedt801c29f2010-03-05 20:02:19 -05003282static int ftrace_set_func(unsigned long *array, int *idx, char *buffer);
3283
Stefan Assmann369bc182009-10-12 22:17:21 +02003284static int __init set_graph_function(char *str)
3285{
Frederic Weisbecker06f43d62009-10-14 20:43:39 +02003286 strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
Stefan Assmann369bc182009-10-12 22:17:21 +02003287 return 1;
3288}
3289__setup("ftrace_graph_filter=", set_graph_function);
3290
3291static void __init set_ftrace_early_graph(char *buf)
3292{
3293 int ret;
3294 char *func;
3295
3296 while (buf) {
3297 func = strsep(&buf, ",");
3298 /* we allow only one expression at a time */
3299 ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,
3300 func);
3301 if (ret)
3302 printk(KERN_DEBUG "ftrace: function %s not "
3303 "traceable\n", func);
3304 }
3305}
3306#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3307
Steven Rostedt2a85a372011-12-19 21:57:44 -05003308void __init
3309ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable)
Steven Rostedt2af15d62009-05-28 13:37:24 -04003310{
3311 char *func;
3312
3313 while (buf) {
3314 func = strsep(&buf, ",");
Steven Rostedtf45948e2011-05-02 12:29:25 -04003315 ftrace_set_regex(ops, func, strlen(func), 0, enable);
Steven Rostedt2af15d62009-05-28 13:37:24 -04003316 }
3317}
3318
3319static void __init set_ftrace_early_filters(void)
3320{
3321 if (ftrace_filter_buf[0])
Steven Rostedt2a85a372011-12-19 21:57:44 -05003322 ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1);
Steven Rostedt2af15d62009-05-28 13:37:24 -04003323 if (ftrace_notrace_buf[0])
Steven Rostedt2a85a372011-12-19 21:57:44 -05003324 ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0);
Stefan Assmann369bc182009-10-12 22:17:21 +02003325#ifdef CONFIG_FUNCTION_GRAPH_TRACER
3326 if (ftrace_graph_buf[0])
3327 set_ftrace_early_graph(ftrace_graph_buf);
3328#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
Steven Rostedt2af15d62009-05-28 13:37:24 -04003329}
3330
Steven Rostedtfc13cb02011-12-19 14:41:25 -05003331int ftrace_regex_release(struct inode *inode, struct file *file)
Steven Rostedt5072c592008-05-12 21:20:43 +02003332{
3333 struct seq_file *m = (struct seq_file *)file->private_data;
3334 struct ftrace_iterator *iter;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003335 struct ftrace_hash **orig_hash;
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02003336 struct trace_parser *parser;
Steven Rostedted926f92011-05-03 13:25:24 -04003337 int filter_hash;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003338 int ret;
Steven Rostedt5072c592008-05-12 21:20:43 +02003339
Steven Rostedt41c52c02008-05-22 11:46:33 -04003340 mutex_lock(&ftrace_regex_lock);
Steven Rostedt5072c592008-05-12 21:20:43 +02003341 if (file->f_mode & FMODE_READ) {
3342 iter = m->private;
3343
3344 seq_release(inode, file);
3345 } else
3346 iter = file->private_data;
3347
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02003348 parser = &iter->parser;
3349 if (trace_parser_loaded(parser)) {
3350 parser->buffer[parser->idx] = 0;
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003351 ftrace_match_records(iter->hash, parser->buffer, parser->idx);
Steven Rostedt5072c592008-05-12 21:20:43 +02003352 }
3353
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02003354 trace_parser_put(parser);
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02003355
Steven Rostedt058e2972011-04-29 22:35:33 -04003356 if (file->f_mode & FMODE_WRITE) {
Steven Rostedted926f92011-05-03 13:25:24 -04003357 filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
3358
3359 if (filter_hash)
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003360 orig_hash = &iter->ops->filter_hash;
Steven Rostedted926f92011-05-03 13:25:24 -04003361 else
3362 orig_hash = &iter->ops->notrace_hash;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003363
Steven Rostedt058e2972011-04-29 22:35:33 -04003364 mutex_lock(&ftrace_lock);
Steven Rostedt41fb61c2011-07-13 15:03:44 -04003365 ret = ftrace_hash_move(iter->ops, filter_hash,
3366 orig_hash, iter->hash);
3367 if (!ret && (iter->ops->flags & FTRACE_OPS_FL_ENABLED)
3368 && ftrace_enabled)
Jiri Olsa30fb6aa2011-12-05 18:22:48 +01003369 ftrace_run_update_code(FTRACE_UPDATE_CALLS);
Steven Rostedt41fb61c2011-07-13 15:03:44 -04003370
Steven Rostedt058e2972011-04-29 22:35:33 -04003371 mutex_unlock(&ftrace_lock);
3372 }
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003373 free_ftrace_hash(iter->hash);
3374 kfree(iter);
Steven Rostedt058e2972011-04-29 22:35:33 -04003375
Steven Rostedt41c52c02008-05-22 11:46:33 -04003376 mutex_unlock(&ftrace_regex_lock);
Steven Rostedt5072c592008-05-12 21:20:43 +02003377 return 0;
3378}
3379
Steven Rostedt5e2336a2009-03-05 21:44:55 -05003380static const struct file_operations ftrace_avail_fops = {
Steven Rostedt5072c592008-05-12 21:20:43 +02003381 .open = ftrace_avail_open,
3382 .read = seq_read,
3383 .llseek = seq_lseek,
Li Zefan3be04b42009-08-17 16:54:03 +08003384 .release = seq_release_private,
Steven Rostedt5072c592008-05-12 21:20:43 +02003385};
3386
Steven Rostedt647bcd02011-05-03 14:39:21 -04003387static const struct file_operations ftrace_enabled_fops = {
3388 .open = ftrace_enabled_open,
3389 .read = seq_read,
3390 .llseek = seq_lseek,
3391 .release = seq_release_private,
3392};
3393
Steven Rostedt5e2336a2009-03-05 21:44:55 -05003394static const struct file_operations ftrace_filter_fops = {
Steven Rostedt5072c592008-05-12 21:20:43 +02003395 .open = ftrace_filter_open,
Lai Jiangshan850a80c2009-03-13 17:47:23 +08003396 .read = seq_read,
Steven Rostedt5072c592008-05-12 21:20:43 +02003397 .write = ftrace_filter_write,
Steven Rostedt98c4fd02010-09-10 11:47:43 -04003398 .llseek = ftrace_regex_lseek,
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003399 .release = ftrace_regex_release,
Steven Rostedt5072c592008-05-12 21:20:43 +02003400};
3401
Steven Rostedt5e2336a2009-03-05 21:44:55 -05003402static const struct file_operations ftrace_notrace_fops = {
Steven Rostedt41c52c02008-05-22 11:46:33 -04003403 .open = ftrace_notrace_open,
Lai Jiangshan850a80c2009-03-13 17:47:23 +08003404 .read = seq_read,
Steven Rostedt41c52c02008-05-22 11:46:33 -04003405 .write = ftrace_notrace_write,
3406 .llseek = ftrace_regex_lseek,
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003407 .release = ftrace_regex_release,
Steven Rostedt41c52c02008-05-22 11:46:33 -04003408};
3409
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003410#ifdef CONFIG_FUNCTION_GRAPH_TRACER
3411
3412static DEFINE_MUTEX(graph_lock);
3413
3414int ftrace_graph_count;
Li Zefanc7c6b1f2010-02-10 15:43:04 +08003415int ftrace_graph_filter_enabled;
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003416unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
3417
3418static void *
Li Zefan85951842009-06-24 09:54:00 +08003419__g_next(struct seq_file *m, loff_t *pos)
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003420{
Li Zefan85951842009-06-24 09:54:00 +08003421 if (*pos >= ftrace_graph_count)
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003422 return NULL;
Li Zefana4ec5e02009-09-18 14:06:28 +08003423 return &ftrace_graph_funcs[*pos];
Li Zefan85951842009-06-24 09:54:00 +08003424}
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003425
Li Zefan85951842009-06-24 09:54:00 +08003426static void *
3427g_next(struct seq_file *m, void *v, loff_t *pos)
3428{
3429 (*pos)++;
3430 return __g_next(m, pos);
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003431}
3432
3433static void *g_start(struct seq_file *m, loff_t *pos)
3434{
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003435 mutex_lock(&graph_lock);
3436
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01003437 /* Nothing, tell g_show to print all functions are enabled */
Li Zefanc7c6b1f2010-02-10 15:43:04 +08003438 if (!ftrace_graph_filter_enabled && !*pos)
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01003439 return (void *)1;
3440
Li Zefan85951842009-06-24 09:54:00 +08003441 return __g_next(m, pos);
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003442}
3443
3444static void g_stop(struct seq_file *m, void *p)
3445{
3446 mutex_unlock(&graph_lock);
3447}
3448
3449static int g_show(struct seq_file *m, void *v)
3450{
3451 unsigned long *ptr = v;
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003452
3453 if (!ptr)
3454 return 0;
3455
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01003456 if (ptr == (unsigned long *)1) {
3457 seq_printf(m, "#### all functions enabled ####\n");
3458 return 0;
3459 }
3460
Steven Rostedtb375a112009-09-17 00:05:58 -04003461 seq_printf(m, "%ps\n", (void *)*ptr);
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003462
3463 return 0;
3464}
3465
James Morris88e9d342009-09-22 16:43:43 -07003466static const struct seq_operations ftrace_graph_seq_ops = {
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003467 .start = g_start,
3468 .next = g_next,
3469 .stop = g_stop,
3470 .show = g_show,
3471};
3472
3473static int
3474ftrace_graph_open(struct inode *inode, struct file *file)
3475{
3476 int ret = 0;
3477
3478 if (unlikely(ftrace_disabled))
3479 return -ENODEV;
3480
3481 mutex_lock(&graph_lock);
3482 if ((file->f_mode & FMODE_WRITE) &&
Steven Rostedt8650ae32009-07-22 23:29:30 -04003483 (file->f_flags & O_TRUNC)) {
Li Zefanc7c6b1f2010-02-10 15:43:04 +08003484 ftrace_graph_filter_enabled = 0;
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003485 ftrace_graph_count = 0;
3486 memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs));
3487 }
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003488 mutex_unlock(&graph_lock);
3489
Li Zefana4ec5e02009-09-18 14:06:28 +08003490 if (file->f_mode & FMODE_READ)
3491 ret = seq_open(file, &ftrace_graph_seq_ops);
3492
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003493 return ret;
3494}
3495
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003496static int
Li Zefan87827112009-07-23 11:29:11 +08003497ftrace_graph_release(struct inode *inode, struct file *file)
3498{
3499 if (file->f_mode & FMODE_READ)
3500 seq_release(inode, file);
3501 return 0;
3502}
3503
3504static int
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01003505ftrace_set_func(unsigned long *array, int *idx, char *buffer)
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003506{
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003507 struct dyn_ftrace *rec;
3508 struct ftrace_page *pg;
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01003509 int search_len;
Li Zefanc7c6b1f2010-02-10 15:43:04 +08003510 int fail = 1;
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01003511 int type, not;
3512 char *search;
3513 bool exists;
3514 int i;
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003515
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01003516 /* decode regex */
Frederic Weisbecker3f6fe062009-09-24 21:31:51 +02003517 type = filter_parse_regex(buffer, strlen(buffer), &search, &not);
Li Zefanc7c6b1f2010-02-10 15:43:04 +08003518 if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS)
3519 return -EBUSY;
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01003520
3521 search_len = strlen(search);
3522
Steven Rostedt52baf112009-02-14 01:15:39 -05003523 mutex_lock(&ftrace_lock);
Steven Rostedt45a4a232011-04-21 23:16:46 -04003524
3525 if (unlikely(ftrace_disabled)) {
3526 mutex_unlock(&ftrace_lock);
3527 return -ENODEV;
3528 }
3529
Steven Rostedt265c8312009-02-13 12:43:56 -05003530 do_for_each_ftrace_rec(pg, rec) {
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003531
Steven Rostedtb9df92d2011-04-28 20:32:08 -04003532 if (ftrace_match_record(rec, NULL, search, search_len, type)) {
Li Zefanc7c6b1f2010-02-10 15:43:04 +08003533 /* if it is in the array */
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01003534 exists = false;
Li Zefanc7c6b1f2010-02-10 15:43:04 +08003535 for (i = 0; i < *idx; i++) {
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01003536 if (array[i] == rec->ip) {
3537 exists = true;
Steven Rostedt265c8312009-02-13 12:43:56 -05003538 break;
3539 }
Li Zefanc7c6b1f2010-02-10 15:43:04 +08003540 }
3541
3542 if (!not) {
3543 fail = 0;
3544 if (!exists) {
3545 array[(*idx)++] = rec->ip;
3546 if (*idx >= FTRACE_GRAPH_MAX_FUNCS)
3547 goto out;
3548 }
3549 } else {
3550 if (exists) {
3551 array[i] = array[--(*idx)];
3552 array[*idx] = 0;
3553 fail = 0;
3554 }
3555 }
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003556 }
Steven Rostedt265c8312009-02-13 12:43:56 -05003557 } while_for_each_ftrace_rec();
Li Zefanc7c6b1f2010-02-10 15:43:04 +08003558out:
Steven Rostedt52baf112009-02-14 01:15:39 -05003559 mutex_unlock(&ftrace_lock);
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003560
Li Zefanc7c6b1f2010-02-10 15:43:04 +08003561 if (fail)
3562 return -EINVAL;
3563
3564 ftrace_graph_filter_enabled = 1;
3565 return 0;
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003566}
3567
3568static ssize_t
3569ftrace_graph_write(struct file *file, const char __user *ubuf,
3570 size_t cnt, loff_t *ppos)
3571{
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02003572 struct trace_parser parser;
Li Zefan4ba79782009-09-22 13:52:20 +08003573 ssize_t read, ret;
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003574
Li Zefanc7c6b1f2010-02-10 15:43:04 +08003575 if (!cnt)
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003576 return 0;
3577
3578 mutex_lock(&graph_lock);
3579
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02003580 if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) {
3581 ret = -ENOMEM;
Li Zefan1eb90f12009-09-22 13:52:57 +08003582 goto out_unlock;
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02003583 }
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003584
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02003585 read = trace_get_user(&parser, ubuf, cnt, ppos);
3586
Li Zefan4ba79782009-09-22 13:52:20 +08003587 if (read >= 0 && trace_parser_loaded((&parser))) {
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02003588 parser.buffer[parser.idx] = 0;
3589
3590 /* we allow only one expression at a time */
Li Zefana4ec5e02009-09-18 14:06:28 +08003591 ret = ftrace_set_func(ftrace_graph_funcs, &ftrace_graph_count,
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02003592 parser.buffer);
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003593 if (ret)
Li Zefan1eb90f12009-09-22 13:52:57 +08003594 goto out_free;
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003595 }
3596
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003597 ret = read;
Li Zefan1eb90f12009-09-22 13:52:57 +08003598
3599out_free:
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02003600 trace_parser_put(&parser);
Li Zefan1eb90f12009-09-22 13:52:57 +08003601out_unlock:
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003602 mutex_unlock(&graph_lock);
3603
3604 return ret;
3605}
3606
3607static const struct file_operations ftrace_graph_fops = {
Li Zefan87827112009-07-23 11:29:11 +08003608 .open = ftrace_graph_open,
3609 .read = seq_read,
3610 .write = ftrace_graph_write,
3611 .release = ftrace_graph_release,
Arnd Bergmann6038f372010-08-15 18:52:59 +02003612 .llseek = seq_lseek,
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003613};
3614#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3615
Steven Rostedtdf4fc312008-11-26 00:16:23 -05003616static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
Steven Rostedt5072c592008-05-12 21:20:43 +02003617{
Steven Rostedt5072c592008-05-12 21:20:43 +02003618
Frederic Weisbecker5452af62009-03-27 00:25:38 +01003619 trace_create_file("available_filter_functions", 0444,
3620 d_tracer, NULL, &ftrace_avail_fops);
Steven Rostedt5072c592008-05-12 21:20:43 +02003621
Steven Rostedt647bcd02011-05-03 14:39:21 -04003622 trace_create_file("enabled_functions", 0444,
3623 d_tracer, NULL, &ftrace_enabled_fops);
3624
Frederic Weisbecker5452af62009-03-27 00:25:38 +01003625 trace_create_file("set_ftrace_filter", 0644, d_tracer,
3626 NULL, &ftrace_filter_fops);
Steven Rostedt41c52c02008-05-22 11:46:33 -04003627
Frederic Weisbecker5452af62009-03-27 00:25:38 +01003628 trace_create_file("set_ftrace_notrace", 0644, d_tracer,
Steven Rostedt41c52c02008-05-22 11:46:33 -04003629 NULL, &ftrace_notrace_fops);
Steven Rostedtad90c0e2008-05-27 20:48:37 -04003630
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003631#ifdef CONFIG_FUNCTION_GRAPH_TRACER
Frederic Weisbecker5452af62009-03-27 00:25:38 +01003632 trace_create_file("set_graph_function", 0444, d_tracer,
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003633 NULL,
3634 &ftrace_graph_fops);
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05003635#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3636
Steven Rostedt5072c592008-05-12 21:20:43 +02003637 return 0;
3638}
3639
Steven Rostedt9fd49322012-04-24 22:32:06 -04003640static int ftrace_cmp_ips(const void *a, const void *b)
Steven Rostedt68950612011-12-16 17:06:45 -05003641{
Steven Rostedt9fd49322012-04-24 22:32:06 -04003642 const unsigned long *ipa = a;
3643 const unsigned long *ipb = b;
Steven Rostedt68950612011-12-16 17:06:45 -05003644
Steven Rostedt9fd49322012-04-24 22:32:06 -04003645 if (*ipa > *ipb)
3646 return 1;
3647 if (*ipa < *ipb)
3648 return -1;
3649 return 0;
3650}
3651
3652static void ftrace_swap_ips(void *a, void *b, int size)
3653{
3654 unsigned long *ipa = a;
3655 unsigned long *ipb = b;
3656 unsigned long t;
3657
3658 t = *ipa;
3659 *ipa = *ipb;
3660 *ipb = t;
Steven Rostedt68950612011-12-16 17:06:45 -05003661}
3662
Jiri Olsa5cb084b2009-10-13 16:33:53 -04003663static int ftrace_process_locs(struct module *mod,
Steven Rostedt31e88902008-11-14 16:21:19 -08003664 unsigned long *start,
Steven Rostedt68bf21a2008-08-14 15:45:08 -04003665 unsigned long *end)
3666{
Steven Rostedt706c81f2012-04-24 23:45:26 -04003667 struct ftrace_page *start_pg;
Steven Rostedta7900872011-12-16 16:23:44 -05003668 struct ftrace_page *pg;
Steven Rostedt706c81f2012-04-24 23:45:26 -04003669 struct dyn_ftrace *rec;
Steven Rostedta7900872011-12-16 16:23:44 -05003670 unsigned long count;
Steven Rostedt68bf21a2008-08-14 15:45:08 -04003671 unsigned long *p;
3672 unsigned long addr;
Steven Rostedt4376cac2011-06-24 23:28:13 -04003673 unsigned long flags = 0; /* Shut up gcc */
Steven Rostedta7900872011-12-16 16:23:44 -05003674 int ret = -ENOMEM;
3675
3676 count = end - start;
3677
3678 if (!count)
3679 return 0;
3680
Steven Rostedt9fd49322012-04-24 22:32:06 -04003681 sort(start, count, sizeof(*start),
3682 ftrace_cmp_ips, ftrace_swap_ips);
3683
Steven Rostedt706c81f2012-04-24 23:45:26 -04003684 start_pg = ftrace_allocate_pages(count);
3685 if (!start_pg)
Steven Rostedta7900872011-12-16 16:23:44 -05003686 return -ENOMEM;
Steven Rostedt68bf21a2008-08-14 15:45:08 -04003687
Steven Rostedte6ea44e2009-02-14 01:42:44 -05003688 mutex_lock(&ftrace_lock);
Steven Rostedta7900872011-12-16 16:23:44 -05003689
Steven Rostedt32082302011-12-16 14:42:37 -05003690 /*
3691 * Core and each module needs their own pages, as
3692 * modules will free them when they are removed.
3693 * Force a new page to be allocated for modules.
3694 */
Steven Rostedta7900872011-12-16 16:23:44 -05003695 if (!mod) {
3696 WARN_ON(ftrace_pages || ftrace_pages_start);
3697 /* First initialization */
Steven Rostedt706c81f2012-04-24 23:45:26 -04003698 ftrace_pages = ftrace_pages_start = start_pg;
Steven Rostedta7900872011-12-16 16:23:44 -05003699 } else {
Steven Rostedt32082302011-12-16 14:42:37 -05003700 if (!ftrace_pages)
Steven Rostedta7900872011-12-16 16:23:44 -05003701 goto out;
Steven Rostedt32082302011-12-16 14:42:37 -05003702
Steven Rostedta7900872011-12-16 16:23:44 -05003703 if (WARN_ON(ftrace_pages->next)) {
3704 /* Hmm, we have free pages? */
3705 while (ftrace_pages->next)
3706 ftrace_pages = ftrace_pages->next;
Steven Rostedt32082302011-12-16 14:42:37 -05003707 }
Steven Rostedta7900872011-12-16 16:23:44 -05003708
Steven Rostedt706c81f2012-04-24 23:45:26 -04003709 ftrace_pages->next = start_pg;
Steven Rostedt32082302011-12-16 14:42:37 -05003710 }
3711
Steven Rostedt68bf21a2008-08-14 15:45:08 -04003712 p = start;
Steven Rostedt706c81f2012-04-24 23:45:26 -04003713 pg = start_pg;
Steven Rostedt68bf21a2008-08-14 15:45:08 -04003714 while (p < end) {
3715 addr = ftrace_call_adjust(*p++);
Steven Rostedt20e52272008-11-14 16:21:19 -08003716 /*
3717 * Some architecture linkers will pad between
3718 * the different mcount_loc sections of different
3719 * object files to satisfy alignments.
3720 * Skip any NULL pointers.
3721 */
3722 if (!addr)
3723 continue;
Steven Rostedt706c81f2012-04-24 23:45:26 -04003724
3725 if (pg->index == pg->size) {
3726 /* We should have allocated enough */
3727 if (WARN_ON(!pg->next))
3728 break;
3729 pg = pg->next;
3730 }
3731
3732 rec = &pg->records[pg->index++];
3733 rec->ip = addr;
Steven Rostedt68bf21a2008-08-14 15:45:08 -04003734 }
3735
Steven Rostedt706c81f2012-04-24 23:45:26 -04003736 /* We should have used all pages */
3737 WARN_ON(pg->next);
3738
3739 /* Assign the last page to ftrace_pages */
3740 ftrace_pages = pg;
3741
Steven Rostedt85ae32a2011-12-16 16:30:31 -05003742 /* These new locations need to be initialized */
Steven Rostedt706c81f2012-04-24 23:45:26 -04003743 ftrace_new_pgs = start_pg;
Steven Rostedt85ae32a2011-12-16 16:30:31 -05003744
Steven Rostedta4f18ed2011-06-07 09:26:46 -04003745 /*
Steven Rostedt4376cac2011-06-24 23:28:13 -04003746 * We only need to disable interrupts on start up
3747 * because we are modifying code that an interrupt
3748 * may execute, and the modification is not atomic.
3749 * But for modules, nothing runs the code we modify
3750 * until we are finished with it, and there's no
3751 * reason to cause large interrupt latencies while we do it.
Steven Rostedta4f18ed2011-06-07 09:26:46 -04003752 */
Steven Rostedt4376cac2011-06-24 23:28:13 -04003753 if (!mod)
3754 local_irq_save(flags);
Steven Rostedt31e88902008-11-14 16:21:19 -08003755 ftrace_update_code(mod);
Steven Rostedt4376cac2011-06-24 23:28:13 -04003756 if (!mod)
3757 local_irq_restore(flags);
Steven Rostedta7900872011-12-16 16:23:44 -05003758 ret = 0;
3759 out:
Steven Rostedte6ea44e2009-02-14 01:42:44 -05003760 mutex_unlock(&ftrace_lock);
Steven Rostedt68bf21a2008-08-14 15:45:08 -04003761
Steven Rostedta7900872011-12-16 16:23:44 -05003762 return ret;
Steven Rostedt68bf21a2008-08-14 15:45:08 -04003763}
3764
Steven Rostedt93eb6772009-04-15 13:24:06 -04003765#ifdef CONFIG_MODULES
Steven Rostedt32082302011-12-16 14:42:37 -05003766
3767#define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
3768
jolsa@redhat.come7247a12009-10-07 19:00:35 +02003769void ftrace_release_mod(struct module *mod)
Steven Rostedt93eb6772009-04-15 13:24:06 -04003770{
3771 struct dyn_ftrace *rec;
Steven Rostedt32082302011-12-16 14:42:37 -05003772 struct ftrace_page **last_pg;
Steven Rostedt93eb6772009-04-15 13:24:06 -04003773 struct ftrace_page *pg;
Steven Rostedta7900872011-12-16 16:23:44 -05003774 int order;
Steven Rostedt93eb6772009-04-15 13:24:06 -04003775
Steven Rostedt93eb6772009-04-15 13:24:06 -04003776 mutex_lock(&ftrace_lock);
Steven Rostedt45a4a232011-04-21 23:16:46 -04003777
3778 if (ftrace_disabled)
3779 goto out_unlock;
3780
Steven Rostedt32082302011-12-16 14:42:37 -05003781 /*
3782 * Each module has its own ftrace_pages, remove
3783 * them from the list.
3784 */
3785 last_pg = &ftrace_pages_start;
3786 for (pg = ftrace_pages_start; pg; pg = *last_pg) {
3787 rec = &pg->records[0];
jolsa@redhat.come7247a12009-10-07 19:00:35 +02003788 if (within_module_core(rec->ip, mod)) {
Steven Rostedt93eb6772009-04-15 13:24:06 -04003789 /*
Steven Rostedt32082302011-12-16 14:42:37 -05003790 * As core pages are first, the first
3791 * page should never be a module page.
Steven Rostedt93eb6772009-04-15 13:24:06 -04003792 */
Steven Rostedt32082302011-12-16 14:42:37 -05003793 if (WARN_ON(pg == ftrace_pages_start))
3794 goto out_unlock;
3795
3796 /* Check if we are deleting the last page */
3797 if (pg == ftrace_pages)
3798 ftrace_pages = next_to_ftrace_page(last_pg);
3799
3800 *last_pg = pg->next;
Steven Rostedta7900872011-12-16 16:23:44 -05003801 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
3802 free_pages((unsigned long)pg->records, order);
3803 kfree(pg);
Steven Rostedt32082302011-12-16 14:42:37 -05003804 } else
3805 last_pg = &pg->next;
3806 }
Steven Rostedt45a4a232011-04-21 23:16:46 -04003807 out_unlock:
Steven Rostedt93eb6772009-04-15 13:24:06 -04003808 mutex_unlock(&ftrace_lock);
3809}
3810
3811static void ftrace_init_module(struct module *mod,
3812 unsigned long *start, unsigned long *end)
Steven Rostedt90d595f2008-08-14 15:45:09 -04003813{
Steven Rostedt00fd61a2008-08-15 21:40:04 -04003814 if (ftrace_disabled || start == end)
Steven Rostedtfed19392008-08-14 22:47:19 -04003815 return;
Jiri Olsa5cb084b2009-10-13 16:33:53 -04003816 ftrace_process_locs(mod, start, end);
Steven Rostedt90d595f2008-08-14 15:45:09 -04003817}
3818
Steven Rostedt93eb6772009-04-15 13:24:06 -04003819static int ftrace_module_notify(struct notifier_block *self,
3820 unsigned long val, void *data)
3821{
3822 struct module *mod = data;
3823
3824 switch (val) {
3825 case MODULE_STATE_COMING:
3826 ftrace_init_module(mod, mod->ftrace_callsites,
3827 mod->ftrace_callsites +
3828 mod->num_ftrace_callsites);
3829 break;
3830 case MODULE_STATE_GOING:
jolsa@redhat.come7247a12009-10-07 19:00:35 +02003831 ftrace_release_mod(mod);
Steven Rostedt93eb6772009-04-15 13:24:06 -04003832 break;
3833 }
3834
3835 return 0;
3836}
3837#else
3838static int ftrace_module_notify(struct notifier_block *self,
3839 unsigned long val, void *data)
3840{
3841 return 0;
3842}
3843#endif /* CONFIG_MODULES */
3844
3845struct notifier_block ftrace_module_nb = {
3846 .notifier_call = ftrace_module_notify,
3847 .priority = 0,
3848};
3849
Steven Rostedt68bf21a2008-08-14 15:45:08 -04003850extern unsigned long __start_mcount_loc[];
3851extern unsigned long __stop_mcount_loc[];
3852
3853void __init ftrace_init(void)
3854{
3855 unsigned long count, addr, flags;
3856 int ret;
3857
3858 /* Keep the ftrace pointer to the stub */
3859 addr = (unsigned long)ftrace_stub;
3860
3861 local_irq_save(flags);
3862 ftrace_dyn_arch_init(&addr);
3863 local_irq_restore(flags);
3864
3865 /* ftrace_dyn_arch_init places the return code in addr */
3866 if (addr)
3867 goto failed;
3868
3869 count = __stop_mcount_loc - __start_mcount_loc;
3870
3871 ret = ftrace_dyn_table_alloc(count);
3872 if (ret)
3873 goto failed;
3874
3875 last_ftrace_enabled = ftrace_enabled = 1;
3876
Jiri Olsa5cb084b2009-10-13 16:33:53 -04003877 ret = ftrace_process_locs(NULL,
Steven Rostedt31e88902008-11-14 16:21:19 -08003878 __start_mcount_loc,
Steven Rostedt68bf21a2008-08-14 15:45:08 -04003879 __stop_mcount_loc);
3880
Steven Rostedt93eb6772009-04-15 13:24:06 -04003881 ret = register_module_notifier(&ftrace_module_nb);
Ming Lei24ed0c42009-05-17 15:31:38 +08003882 if (ret)
Steven Rostedt93eb6772009-04-15 13:24:06 -04003883 pr_warning("Failed to register trace ftrace module notifier\n");
3884
Steven Rostedt2af15d62009-05-28 13:37:24 -04003885 set_ftrace_early_filters();
3886
Steven Rostedt68bf21a2008-08-14 15:45:08 -04003887 return;
3888 failed:
3889 ftrace_disabled = 1;
3890}
Steven Rostedt68bf21a2008-08-14 15:45:08 -04003891
Steven Rostedt3d083392008-05-12 21:20:42 +02003892#else
Frederic Weisbecker0b6e4d52008-10-28 20:17:38 +01003893
Steven Rostedt2b499382011-05-03 22:49:52 -04003894static struct ftrace_ops global_ops = {
Steven Rostedtbd69c302011-05-03 21:55:54 -04003895 .func = ftrace_stub,
3896};
3897
Frederic Weisbecker0b6e4d52008-10-28 20:17:38 +01003898static int __init ftrace_nodyn_init(void)
3899{
3900 ftrace_enabled = 1;
3901 return 0;
3902}
3903device_initcall(ftrace_nodyn_init);
3904
Steven Rostedtdf4fc312008-11-26 00:16:23 -05003905static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }
3906static inline void ftrace_startup_enable(int command) { }
Steven Rostedt5a45cfe2008-11-26 00:16:24 -05003907/* Keep as macros so we do not need to define the commands */
Steven Rostedt3b6cfdb2011-05-23 15:33:49 -04003908# define ftrace_startup(ops, command) \
3909 ({ \
3910 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
3911 0; \
3912 })
Steven Rostedtbd69c302011-05-03 21:55:54 -04003913# define ftrace_shutdown(ops, command) do { } while (0)
Ingo Molnarc7aafc52008-05-12 21:20:45 +02003914# define ftrace_startup_sysctl() do { } while (0)
3915# define ftrace_shutdown_sysctl() do { } while (0)
Steven Rostedtb8489142011-05-04 09:27:52 -04003916
3917static inline int
3918ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip)
3919{
3920 return 1;
3921}
3922
Steven Rostedt3d083392008-05-12 21:20:42 +02003923#endif /* CONFIG_DYNAMIC_FTRACE */
3924
Steven Rostedtb8489142011-05-04 09:27:52 -04003925static void
Jiri Olsae2484912012-02-15 15:51:48 +01003926ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip)
3927{
3928 struct ftrace_ops *op;
3929
3930 if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT)))
3931 return;
3932
3933 /*
3934 * Some of the ops may be dynamically allocated,
3935 * they must be freed after a synchronize_sched().
3936 */
3937 preempt_disable_notrace();
3938 trace_recursion_set(TRACE_CONTROL_BIT);
3939 op = rcu_dereference_raw(ftrace_control_list);
3940 while (op != &ftrace_list_end) {
3941 if (!ftrace_function_local_disabled(op) &&
3942 ftrace_ops_test(op, ip))
3943 op->func(ip, parent_ip);
3944
3945 op = rcu_dereference_raw(op->next);
3946 };
3947 trace_recursion_clear(TRACE_CONTROL_BIT);
3948 preempt_enable_notrace();
3949}
3950
3951static struct ftrace_ops control_ops = {
3952 .func = ftrace_ops_control_func,
3953};
3954
3955static void
Steven Rostedtb8489142011-05-04 09:27:52 -04003956ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip)
3957{
Steven Rostedtcdbe61b2011-05-05 21:14:55 -04003958 struct ftrace_ops *op;
Steven Rostedtb8489142011-05-04 09:27:52 -04003959
Steven Rostedtb1cff0a2011-05-25 14:27:43 -04003960 if (unlikely(trace_recursion_test(TRACE_INTERNAL_BIT)))
3961 return;
3962
3963 trace_recursion_set(TRACE_INTERNAL_BIT);
Steven Rostedtcdbe61b2011-05-05 21:14:55 -04003964 /*
3965 * Some of the ops may be dynamically allocated,
3966 * they must be freed after a synchronize_sched().
3967 */
3968 preempt_disable_notrace();
3969 op = rcu_dereference_raw(ftrace_ops_list);
Steven Rostedtb8489142011-05-04 09:27:52 -04003970 while (op != &ftrace_list_end) {
3971 if (ftrace_ops_test(op, ip))
3972 op->func(ip, parent_ip);
3973 op = rcu_dereference_raw(op->next);
3974 };
Steven Rostedtcdbe61b2011-05-05 21:14:55 -04003975 preempt_enable_notrace();
Steven Rostedtb1cff0a2011-05-25 14:27:43 -04003976 trace_recursion_clear(TRACE_INTERNAL_BIT);
Steven Rostedtb8489142011-05-04 09:27:52 -04003977}
3978
Steven Rostedte32d8952008-12-04 00:26:41 -05003979static void clear_ftrace_swapper(void)
3980{
3981 struct task_struct *p;
3982 int cpu;
3983
3984 get_online_cpus();
3985 for_each_online_cpu(cpu) {
3986 p = idle_task(cpu);
3987 clear_tsk_trace_trace(p);
3988 }
3989 put_online_cpus();
3990}
3991
3992static void set_ftrace_swapper(void)
3993{
3994 struct task_struct *p;
3995 int cpu;
3996
3997 get_online_cpus();
3998 for_each_online_cpu(cpu) {
3999 p = idle_task(cpu);
4000 set_tsk_trace_trace(p);
4001 }
4002 put_online_cpus();
4003}
4004
4005static void clear_ftrace_pid(struct pid *pid)
Steven Rostedt978f3a42008-12-04 00:26:40 -05004006{
4007 struct task_struct *p;
4008
Oleg Nesterov229c4ef2009-02-03 20:39:04 +01004009 rcu_read_lock();
Steven Rostedte32d8952008-12-04 00:26:41 -05004010 do_each_pid_task(pid, PIDTYPE_PID, p) {
Steven Rostedt978f3a42008-12-04 00:26:40 -05004011 clear_tsk_trace_trace(p);
Steven Rostedte32d8952008-12-04 00:26:41 -05004012 } while_each_pid_task(pid, PIDTYPE_PID, p);
Oleg Nesterov229c4ef2009-02-03 20:39:04 +01004013 rcu_read_unlock();
4014
Steven Rostedte32d8952008-12-04 00:26:41 -05004015 put_pid(pid);
Steven Rostedt978f3a42008-12-04 00:26:40 -05004016}
4017
Steven Rostedte32d8952008-12-04 00:26:41 -05004018static void set_ftrace_pid(struct pid *pid)
Steven Rostedt978f3a42008-12-04 00:26:40 -05004019{
4020 struct task_struct *p;
4021
Oleg Nesterov229c4ef2009-02-03 20:39:04 +01004022 rcu_read_lock();
Steven Rostedt978f3a42008-12-04 00:26:40 -05004023 do_each_pid_task(pid, PIDTYPE_PID, p) {
4024 set_tsk_trace_trace(p);
4025 } while_each_pid_task(pid, PIDTYPE_PID, p);
Oleg Nesterov229c4ef2009-02-03 20:39:04 +01004026 rcu_read_unlock();
Steven Rostedt978f3a42008-12-04 00:26:40 -05004027}
4028
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04004029static void clear_ftrace_pid_task(struct pid *pid)
Steven Rostedte32d8952008-12-04 00:26:41 -05004030{
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04004031 if (pid == ftrace_swapper_pid)
Steven Rostedte32d8952008-12-04 00:26:41 -05004032 clear_ftrace_swapper();
4033 else
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04004034 clear_ftrace_pid(pid);
Steven Rostedte32d8952008-12-04 00:26:41 -05004035}
4036
4037static void set_ftrace_pid_task(struct pid *pid)
4038{
4039 if (pid == ftrace_swapper_pid)
4040 set_ftrace_swapper();
4041 else
4042 set_ftrace_pid(pid);
4043}
4044
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04004045static int ftrace_pid_add(int p)
4046{
4047 struct pid *pid;
4048 struct ftrace_pid *fpid;
4049 int ret = -EINVAL;
4050
4051 mutex_lock(&ftrace_lock);
4052
4053 if (!p)
4054 pid = ftrace_swapper_pid;
4055 else
4056 pid = find_get_pid(p);
4057
4058 if (!pid)
4059 goto out;
4060
4061 ret = 0;
4062
4063 list_for_each_entry(fpid, &ftrace_pids, list)
4064 if (fpid->pid == pid)
4065 goto out_put;
4066
4067 ret = -ENOMEM;
4068
4069 fpid = kmalloc(sizeof(*fpid), GFP_KERNEL);
4070 if (!fpid)
4071 goto out_put;
4072
4073 list_add(&fpid->list, &ftrace_pids);
4074 fpid->pid = pid;
4075
4076 set_ftrace_pid_task(pid);
4077
4078 ftrace_update_pid_func();
4079 ftrace_startup_enable(0);
4080
4081 mutex_unlock(&ftrace_lock);
4082 return 0;
4083
4084out_put:
4085 if (pid != ftrace_swapper_pid)
4086 put_pid(pid);
4087
4088out:
4089 mutex_unlock(&ftrace_lock);
4090 return ret;
4091}
4092
4093static void ftrace_pid_reset(void)
4094{
4095 struct ftrace_pid *fpid, *safe;
4096
4097 mutex_lock(&ftrace_lock);
4098 list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) {
4099 struct pid *pid = fpid->pid;
4100
4101 clear_ftrace_pid_task(pid);
4102
4103 list_del(&fpid->list);
4104 kfree(fpid);
4105 }
4106
4107 ftrace_update_pid_func();
4108 ftrace_startup_enable(0);
4109
4110 mutex_unlock(&ftrace_lock);
4111}
4112
4113static void *fpid_start(struct seq_file *m, loff_t *pos)
4114{
4115 mutex_lock(&ftrace_lock);
4116
4117 if (list_empty(&ftrace_pids) && (!*pos))
4118 return (void *) 1;
4119
4120 return seq_list_start(&ftrace_pids, *pos);
4121}
4122
4123static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
4124{
4125 if (v == (void *)1)
4126 return NULL;
4127
4128 return seq_list_next(v, &ftrace_pids, pos);
4129}
4130
4131static void fpid_stop(struct seq_file *m, void *p)
4132{
4133 mutex_unlock(&ftrace_lock);
4134}
4135
4136static int fpid_show(struct seq_file *m, void *v)
4137{
4138 const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list);
4139
4140 if (v == (void *)1) {
4141 seq_printf(m, "no pid\n");
4142 return 0;
4143 }
4144
4145 if (fpid->pid == ftrace_swapper_pid)
4146 seq_printf(m, "swapper tasks\n");
4147 else
4148 seq_printf(m, "%u\n", pid_vnr(fpid->pid));
4149
4150 return 0;
4151}
4152
4153static const struct seq_operations ftrace_pid_sops = {
4154 .start = fpid_start,
4155 .next = fpid_next,
4156 .stop = fpid_stop,
4157 .show = fpid_show,
4158};
4159
4160static int
4161ftrace_pid_open(struct inode *inode, struct file *file)
4162{
4163 int ret = 0;
4164
4165 if ((file->f_mode & FMODE_WRITE) &&
4166 (file->f_flags & O_TRUNC))
4167 ftrace_pid_reset();
4168
4169 if (file->f_mode & FMODE_READ)
4170 ret = seq_open(file, &ftrace_pid_sops);
4171
4172 return ret;
4173}
4174
Steven Rostedtdf4fc312008-11-26 00:16:23 -05004175static ssize_t
4176ftrace_pid_write(struct file *filp, const char __user *ubuf,
4177 size_t cnt, loff_t *ppos)
4178{
Ingo Molnar457dc922009-11-23 11:03:28 +01004179 char buf[64], *tmp;
Steven Rostedtdf4fc312008-11-26 00:16:23 -05004180 long val;
4181 int ret;
4182
4183 if (cnt >= sizeof(buf))
4184 return -EINVAL;
4185
4186 if (copy_from_user(&buf, ubuf, cnt))
4187 return -EFAULT;
4188
4189 buf[cnt] = 0;
4190
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04004191 /*
4192 * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid"
4193 * to clean the filter quietly.
4194 */
Ingo Molnar457dc922009-11-23 11:03:28 +01004195 tmp = strstrip(buf);
4196 if (strlen(tmp) == 0)
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04004197 return 1;
4198
Ingo Molnar457dc922009-11-23 11:03:28 +01004199 ret = strict_strtol(tmp, 10, &val);
Steven Rostedtdf4fc312008-11-26 00:16:23 -05004200 if (ret < 0)
4201 return ret;
4202
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04004203 ret = ftrace_pid_add(val);
Steven Rostedt978f3a42008-12-04 00:26:40 -05004204
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04004205 return ret ? ret : cnt;
4206}
Steven Rostedtdf4fc312008-11-26 00:16:23 -05004207
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04004208static int
4209ftrace_pid_release(struct inode *inode, struct file *file)
4210{
4211 if (file->f_mode & FMODE_READ)
4212 seq_release(inode, file);
Steven Rostedtdf4fc312008-11-26 00:16:23 -05004213
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04004214 return 0;
Steven Rostedtdf4fc312008-11-26 00:16:23 -05004215}
4216
Steven Rostedt5e2336a2009-03-05 21:44:55 -05004217static const struct file_operations ftrace_pid_fops = {
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04004218 .open = ftrace_pid_open,
4219 .write = ftrace_pid_write,
4220 .read = seq_read,
4221 .llseek = seq_lseek,
4222 .release = ftrace_pid_release,
Steven Rostedtdf4fc312008-11-26 00:16:23 -05004223};
4224
4225static __init int ftrace_init_debugfs(void)
4226{
4227 struct dentry *d_tracer;
Steven Rostedtdf4fc312008-11-26 00:16:23 -05004228
4229 d_tracer = tracing_init_dentry();
4230 if (!d_tracer)
4231 return 0;
4232
4233 ftrace_init_dyn_debugfs(d_tracer);
4234
Frederic Weisbecker5452af62009-03-27 00:25:38 +01004235 trace_create_file("set_ftrace_pid", 0644, d_tracer,
4236 NULL, &ftrace_pid_fops);
Steven Rostedt493762f2009-03-23 17:12:36 -04004237
4238 ftrace_profile_debugfs(d_tracer);
4239
Steven Rostedtdf4fc312008-11-26 00:16:23 -05004240 return 0;
4241}
Steven Rostedtdf4fc312008-11-26 00:16:23 -05004242fs_initcall(ftrace_init_debugfs);
4243
Steven Rostedt3d083392008-05-12 21:20:42 +02004244/**
Steven Rostedt81adbdc2008-10-23 09:33:02 -04004245 * ftrace_kill - kill ftrace
Steven Rostedta2bb6a32008-07-10 20:58:15 -04004246 *
4247 * This function should be used by panic code. It stops ftrace
4248 * but in a not so nice way. If you need to simply kill ftrace
4249 * from a non-atomic section, use ftrace_kill.
4250 */
Steven Rostedt81adbdc2008-10-23 09:33:02 -04004251void ftrace_kill(void)
Steven Rostedta2bb6a32008-07-10 20:58:15 -04004252{
4253 ftrace_disabled = 1;
4254 ftrace_enabled = 0;
Steven Rostedta2bb6a32008-07-10 20:58:15 -04004255 clear_ftrace_function();
4256}
4257
4258/**
Steven Rostedte0a413f2011-09-29 21:26:16 -04004259 * Test if ftrace is dead or not.
4260 */
4261int ftrace_is_dead(void)
4262{
4263 return ftrace_disabled;
4264}
4265
4266/**
Steven Rostedt3d083392008-05-12 21:20:42 +02004267 * register_ftrace_function - register a function for profiling
4268 * @ops - ops structure that holds the function for profiling.
4269 *
4270 * Register a function to be called by all functions in the
4271 * kernel.
4272 *
4273 * Note: @ops->func and all the functions it calls must be labeled
4274 * with "notrace", otherwise it will go into a
4275 * recursive loop.
4276 */
4277int register_ftrace_function(struct ftrace_ops *ops)
4278{
Steven Rostedt45a4a232011-04-21 23:16:46 -04004279 int ret = -1;
Steven Rostedt4eebcc82008-05-12 21:20:48 +02004280
Steven Rostedte6ea44e2009-02-14 01:42:44 -05004281 mutex_lock(&ftrace_lock);
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01004282
Steven Rostedt45a4a232011-04-21 23:16:46 -04004283 if (unlikely(ftrace_disabled))
4284 goto out_unlock;
4285
Steven Rostedtb0fc4942008-05-12 21:20:43 +02004286 ret = __register_ftrace_function(ops);
Steven Rostedtb8489142011-05-04 09:27:52 -04004287 if (!ret)
Steven Rostedta1cd6172011-05-23 15:24:25 -04004288 ret = ftrace_startup(ops, 0);
Steven Rostedtb8489142011-05-04 09:27:52 -04004289
Steven Rostedtb0fc4942008-05-12 21:20:43 +02004290
Steven Rostedt45a4a232011-04-21 23:16:46 -04004291 out_unlock:
Steven Rostedte6ea44e2009-02-14 01:42:44 -05004292 mutex_unlock(&ftrace_lock);
Steven Rostedtb0fc4942008-05-12 21:20:43 +02004293 return ret;
Steven Rostedt3d083392008-05-12 21:20:42 +02004294}
Steven Rostedtcdbe61b2011-05-05 21:14:55 -04004295EXPORT_SYMBOL_GPL(register_ftrace_function);
Steven Rostedt3d083392008-05-12 21:20:42 +02004296
4297/**
Uwe Kleine-Koenig32632922009-01-12 23:35:50 +01004298 * unregister_ftrace_function - unregister a function for profiling.
Steven Rostedt3d083392008-05-12 21:20:42 +02004299 * @ops - ops structure that holds the function to unregister
4300 *
4301 * Unregister a function that was added to be called by ftrace profiling.
4302 */
4303int unregister_ftrace_function(struct ftrace_ops *ops)
4304{
4305 int ret;
4306
Steven Rostedte6ea44e2009-02-14 01:42:44 -05004307 mutex_lock(&ftrace_lock);
Steven Rostedt3d083392008-05-12 21:20:42 +02004308 ret = __unregister_ftrace_function(ops);
Steven Rostedtb8489142011-05-04 09:27:52 -04004309 if (!ret)
4310 ftrace_shutdown(ops, 0);
Steven Rostedte6ea44e2009-02-14 01:42:44 -05004311 mutex_unlock(&ftrace_lock);
Steven Rostedtb0fc4942008-05-12 21:20:43 +02004312
4313 return ret;
4314}
Steven Rostedtcdbe61b2011-05-05 21:14:55 -04004315EXPORT_SYMBOL_GPL(unregister_ftrace_function);
Steven Rostedtb0fc4942008-05-12 21:20:43 +02004316
Ingo Molnare309b412008-05-12 21:20:51 +02004317int
Steven Rostedtb0fc4942008-05-12 21:20:43 +02004318ftrace_enable_sysctl(struct ctl_table *table, int write,
Alexey Dobriyan8d65af72009-09-23 15:57:19 -07004319 void __user *buffer, size_t *lenp,
Steven Rostedtb0fc4942008-05-12 21:20:43 +02004320 loff_t *ppos)
4321{
Steven Rostedt45a4a232011-04-21 23:16:46 -04004322 int ret = -ENODEV;
Steven Rostedt4eebcc82008-05-12 21:20:48 +02004323
Steven Rostedte6ea44e2009-02-14 01:42:44 -05004324 mutex_lock(&ftrace_lock);
Steven Rostedtb0fc4942008-05-12 21:20:43 +02004325
Steven Rostedt45a4a232011-04-21 23:16:46 -04004326 if (unlikely(ftrace_disabled))
4327 goto out;
4328
4329 ret = proc_dointvec(table, write, buffer, lenp, ppos);
Steven Rostedtb0fc4942008-05-12 21:20:43 +02004330
Li Zefana32c7762009-06-26 16:55:51 +08004331 if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
Steven Rostedtb0fc4942008-05-12 21:20:43 +02004332 goto out;
4333
Li Zefana32c7762009-06-26 16:55:51 +08004334 last_ftrace_enabled = !!ftrace_enabled;
Steven Rostedtb0fc4942008-05-12 21:20:43 +02004335
4336 if (ftrace_enabled) {
4337
4338 ftrace_startup_sysctl();
4339
4340 /* we are starting ftrace again */
Steven Rostedtb8489142011-05-04 09:27:52 -04004341 if (ftrace_ops_list != &ftrace_list_end) {
4342 if (ftrace_ops_list->next == &ftrace_list_end)
4343 ftrace_trace_function = ftrace_ops_list->func;
Steven Rostedtb0fc4942008-05-12 21:20:43 +02004344 else
Steven Rostedtb8489142011-05-04 09:27:52 -04004345 ftrace_trace_function = ftrace_ops_list_func;
Steven Rostedtb0fc4942008-05-12 21:20:43 +02004346 }
4347
4348 } else {
4349 /* stopping ftrace calls (just send to ftrace_stub) */
4350 ftrace_trace_function = ftrace_stub;
4351
4352 ftrace_shutdown_sysctl();
4353 }
4354
4355 out:
Steven Rostedte6ea44e2009-02-14 01:42:44 -05004356 mutex_unlock(&ftrace_lock);
Steven Rostedt3d083392008-05-12 21:20:42 +02004357 return ret;
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +02004358}
Ingo Molnarf17845e2008-10-24 12:47:10 +02004359
Frederic Weisbeckerfb526072008-11-25 21:07:04 +01004360#ifdef CONFIG_FUNCTION_GRAPH_TRACER
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01004361
Steven Rostedt597af812009-04-03 15:24:12 -04004362static int ftrace_graph_active;
Frederic Weisbecker4a2b8dd2009-01-14 13:33:27 -08004363static struct notifier_block ftrace_suspend_notifier;
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01004364
Steven Rostedte49dc192008-12-02 23:50:05 -05004365int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
4366{
4367 return 0;
4368}
4369
Frederic Weisbecker287b6e62008-11-26 00:57:25 +01004370/* The callbacks that hook a function */
4371trace_func_graph_ret_t ftrace_graph_return =
4372 (trace_func_graph_ret_t)ftrace_stub;
Steven Rostedte49dc192008-12-02 23:50:05 -05004373trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01004374
4375/* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
4376static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
4377{
4378 int i;
4379 int ret = 0;
4380 unsigned long flags;
4381 int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
4382 struct task_struct *g, *t;
4383
4384 for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
4385 ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH
4386 * sizeof(struct ftrace_ret_stack),
4387 GFP_KERNEL);
4388 if (!ret_stack_list[i]) {
4389 start = 0;
4390 end = i;
4391 ret = -ENOMEM;
4392 goto free;
4393 }
4394 }
4395
4396 read_lock_irqsave(&tasklist_lock, flags);
4397 do_each_thread(g, t) {
4398 if (start == end) {
4399 ret = -EAGAIN;
4400 goto unlock;
4401 }
4402
4403 if (t->ret_stack == NULL) {
Frederic Weisbecker380c4b12008-12-06 03:43:41 +01004404 atomic_set(&t->tracing_graph_pause, 0);
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01004405 atomic_set(&t->trace_overrun, 0);
Steven Rostedt26c01622009-06-02 14:01:19 -04004406 t->curr_ret_stack = -1;
4407 /* Make sure the tasks see the -1 first: */
4408 smp_wmb();
4409 t->ret_stack = ret_stack_list[start++];
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01004410 }
4411 } while_each_thread(g, t);
4412
4413unlock:
4414 read_unlock_irqrestore(&tasklist_lock, flags);
4415free:
4416 for (i = start; i < end; i++)
4417 kfree(ret_stack_list[i]);
4418 return ret;
4419}
4420
Steven Rostedt8aef2d22009-03-24 01:10:15 -04004421static void
Steven Rostedt38516ab2010-04-20 17:04:50 -04004422ftrace_graph_probe_sched_switch(void *ignore,
4423 struct task_struct *prev, struct task_struct *next)
Steven Rostedt8aef2d22009-03-24 01:10:15 -04004424{
4425 unsigned long long timestamp;
4426 int index;
4427
Steven Rostedtbe6f1642009-03-24 11:06:24 -04004428 /*
4429 * Does the user want to count the time a function was asleep.
4430 * If so, do not update the time stamps.
4431 */
4432 if (trace_flags & TRACE_ITER_SLEEP_TIME)
4433 return;
4434
Steven Rostedt8aef2d22009-03-24 01:10:15 -04004435 timestamp = trace_clock_local();
4436
4437 prev->ftrace_timestamp = timestamp;
4438
4439 /* only process tasks that we timestamped */
4440 if (!next->ftrace_timestamp)
4441 return;
4442
4443 /*
4444 * Update all the counters in next to make up for the
4445 * time next was sleeping.
4446 */
4447 timestamp -= next->ftrace_timestamp;
4448
4449 for (index = next->curr_ret_stack; index >= 0; index--)
4450 next->ret_stack[index].calltime += timestamp;
4451}
4452
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01004453/* Allocate a return stack for each task */
Frederic Weisbeckerfb526072008-11-25 21:07:04 +01004454static int start_graph_tracing(void)
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01004455{
4456 struct ftrace_ret_stack **ret_stack_list;
Frederic Weisbecker5b058bc2009-02-17 18:35:34 +01004457 int ret, cpu;
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01004458
4459 ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
4460 sizeof(struct ftrace_ret_stack *),
4461 GFP_KERNEL);
4462
4463 if (!ret_stack_list)
4464 return -ENOMEM;
4465
Frederic Weisbecker5b058bc2009-02-17 18:35:34 +01004466 /* The cpu_boot init_task->ret_stack will never be freed */
Steven Rostedt179c4982009-06-02 12:03:19 -04004467 for_each_online_cpu(cpu) {
4468 if (!idle_task(cpu)->ret_stack)
Steven Rostedt868baf02011-02-10 21:26:13 -05004469 ftrace_graph_init_idle_task(idle_task(cpu), cpu);
Steven Rostedt179c4982009-06-02 12:03:19 -04004470 }
Frederic Weisbecker5b058bc2009-02-17 18:35:34 +01004471
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01004472 do {
4473 ret = alloc_retstack_tasklist(ret_stack_list);
4474 } while (ret == -EAGAIN);
4475
Steven Rostedt8aef2d22009-03-24 01:10:15 -04004476 if (!ret) {
Steven Rostedt38516ab2010-04-20 17:04:50 -04004477 ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
Steven Rostedt8aef2d22009-03-24 01:10:15 -04004478 if (ret)
4479 pr_info("ftrace_graph: Couldn't activate tracepoint"
4480 " probe to kernel_sched_switch\n");
4481 }
4482
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01004483 kfree(ret_stack_list);
4484 return ret;
4485}
4486
Frederic Weisbecker4a2b8dd2009-01-14 13:33:27 -08004487/*
4488 * Hibernation protection.
4489 * The state of the current task is too much unstable during
4490 * suspend/restore to disk. We want to protect against that.
4491 */
4492static int
4493ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
4494 void *unused)
4495{
4496 switch (state) {
4497 case PM_HIBERNATION_PREPARE:
4498 pause_graph_tracing();
4499 break;
4500
4501 case PM_POST_HIBERNATION:
4502 unpause_graph_tracing();
4503 break;
4504 }
4505 return NOTIFY_DONE;
4506}
4507
Frederic Weisbecker287b6e62008-11-26 00:57:25 +01004508int register_ftrace_graph(trace_func_graph_ret_t retfunc,
4509 trace_func_graph_ent_t entryfunc)
Frederic Weisbecker15e6cb32008-11-11 07:14:25 +01004510{
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01004511 int ret = 0;
4512
Steven Rostedte6ea44e2009-02-14 01:42:44 -05004513 mutex_lock(&ftrace_lock);
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01004514
Steven Rostedt05ce5812009-03-24 00:18:31 -04004515 /* we currently allow only one tracer registered at a time */
Steven Rostedt597af812009-04-03 15:24:12 -04004516 if (ftrace_graph_active) {
Steven Rostedt05ce5812009-03-24 00:18:31 -04004517 ret = -EBUSY;
4518 goto out;
4519 }
4520
Frederic Weisbecker4a2b8dd2009-01-14 13:33:27 -08004521 ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call;
4522 register_pm_notifier(&ftrace_suspend_notifier);
4523
Steven Rostedt597af812009-04-03 15:24:12 -04004524 ftrace_graph_active++;
Frederic Weisbeckerfb526072008-11-25 21:07:04 +01004525 ret = start_graph_tracing();
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01004526 if (ret) {
Steven Rostedt597af812009-04-03 15:24:12 -04004527 ftrace_graph_active--;
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01004528 goto out;
4529 }
Steven Rostedte53a6312008-11-26 00:16:25 -05004530
Frederic Weisbecker287b6e62008-11-26 00:57:25 +01004531 ftrace_graph_return = retfunc;
4532 ftrace_graph_entry = entryfunc;
Steven Rostedte53a6312008-11-26 00:16:25 -05004533
Steven Rostedta1cd6172011-05-23 15:24:25 -04004534 ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET);
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01004535
4536out:
Steven Rostedte6ea44e2009-02-14 01:42:44 -05004537 mutex_unlock(&ftrace_lock);
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01004538 return ret;
Frederic Weisbecker15e6cb32008-11-11 07:14:25 +01004539}
4540
Frederic Weisbeckerfb526072008-11-25 21:07:04 +01004541void unregister_ftrace_graph(void)
Frederic Weisbecker15e6cb32008-11-11 07:14:25 +01004542{
Steven Rostedte6ea44e2009-02-14 01:42:44 -05004543 mutex_lock(&ftrace_lock);
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01004544
Steven Rostedt597af812009-04-03 15:24:12 -04004545 if (unlikely(!ftrace_graph_active))
Steven Rostedt2aad1b72009-03-30 11:11:28 -04004546 goto out;
4547
Steven Rostedt597af812009-04-03 15:24:12 -04004548 ftrace_graph_active--;
Frederic Weisbecker287b6e62008-11-26 00:57:25 +01004549 ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
Steven Rostedte49dc192008-12-02 23:50:05 -05004550 ftrace_graph_entry = ftrace_graph_entry_stub;
Steven Rostedtbd69c302011-05-03 21:55:54 -04004551 ftrace_shutdown(&global_ops, FTRACE_STOP_FUNC_RET);
Frederic Weisbecker4a2b8dd2009-01-14 13:33:27 -08004552 unregister_pm_notifier(&ftrace_suspend_notifier);
Steven Rostedt38516ab2010-04-20 17:04:50 -04004553 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01004554
Steven Rostedt2aad1b72009-03-30 11:11:28 -04004555 out:
Steven Rostedte6ea44e2009-02-14 01:42:44 -05004556 mutex_unlock(&ftrace_lock);
Frederic Weisbecker15e6cb32008-11-11 07:14:25 +01004557}
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01004558
Steven Rostedt868baf02011-02-10 21:26:13 -05004559static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack);
4560
4561static void
4562graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack)
4563{
4564 atomic_set(&t->tracing_graph_pause, 0);
4565 atomic_set(&t->trace_overrun, 0);
4566 t->ftrace_timestamp = 0;
Lucas De Marchi25985ed2011-03-30 22:57:33 -03004567 /* make curr_ret_stack visible before we add the ret_stack */
Steven Rostedt868baf02011-02-10 21:26:13 -05004568 smp_wmb();
4569 t->ret_stack = ret_stack;
4570}
4571
4572/*
4573 * Allocate a return stack for the idle task. May be the first
4574 * time through, or it may be done by CPU hotplug online.
4575 */
4576void ftrace_graph_init_idle_task(struct task_struct *t, int cpu)
4577{
4578 t->curr_ret_stack = -1;
4579 /*
4580 * The idle task has no parent, it either has its own
4581 * stack or no stack at all.
4582 */
4583 if (t->ret_stack)
4584 WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu));
4585
4586 if (ftrace_graph_active) {
4587 struct ftrace_ret_stack *ret_stack;
4588
4589 ret_stack = per_cpu(idle_ret_stack, cpu);
4590 if (!ret_stack) {
4591 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
4592 * sizeof(struct ftrace_ret_stack),
4593 GFP_KERNEL);
4594 if (!ret_stack)
4595 return;
4596 per_cpu(idle_ret_stack, cpu) = ret_stack;
4597 }
4598 graph_init_task(t, ret_stack);
4599 }
4600}
4601
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01004602/* Allocate a return stack for newly created task */
Frederic Weisbeckerfb526072008-11-25 21:07:04 +01004603void ftrace_graph_init_task(struct task_struct *t)
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01004604{
Steven Rostedt84047e32009-06-02 16:51:55 -04004605 /* Make sure we do not use the parent ret_stack */
4606 t->ret_stack = NULL;
Steven Rostedtea14eb72010-03-12 19:41:23 -05004607 t->curr_ret_stack = -1;
Steven Rostedt84047e32009-06-02 16:51:55 -04004608
Steven Rostedt597af812009-04-03 15:24:12 -04004609 if (ftrace_graph_active) {
Steven Rostedt82310a32009-06-02 12:26:07 -04004610 struct ftrace_ret_stack *ret_stack;
4611
4612 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01004613 * sizeof(struct ftrace_ret_stack),
4614 GFP_KERNEL);
Steven Rostedt82310a32009-06-02 12:26:07 -04004615 if (!ret_stack)
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01004616 return;
Steven Rostedt868baf02011-02-10 21:26:13 -05004617 graph_init_task(t, ret_stack);
Steven Rostedt84047e32009-06-02 16:51:55 -04004618 }
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01004619}
4620
Frederic Weisbeckerfb526072008-11-25 21:07:04 +01004621void ftrace_graph_exit_task(struct task_struct *t)
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01004622{
Frederic Weisbeckereae849c2008-11-23 17:33:12 +01004623 struct ftrace_ret_stack *ret_stack = t->ret_stack;
4624
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01004625 t->ret_stack = NULL;
Frederic Weisbeckereae849c2008-11-23 17:33:12 +01004626 /* NULL must become visible to IRQs before we free it: */
4627 barrier();
4628
4629 kfree(ret_stack);
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01004630}
Steven Rostedt14a866c2008-12-02 23:50:02 -05004631
4632void ftrace_graph_stop(void)
4633{
4634 ftrace_stop();
4635}
Frederic Weisbecker15e6cb32008-11-11 07:14:25 +01004636#endif