blob: fb186b9ddf519159d866fcaa8fc187328820f2bf [file] [log] [blame]
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
Nadia Yvette Chambers6d49e352012-12-06 10:39:54 +010013 * Copyright (C) 2004 Nadia Yvette Chambers
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +020014 */
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 Rostedt6912896e2008-10-23 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 Rostedt6912896e2008-10-23 09:33:03 -040047 ftrace_kill(); \
Steven Rostedt0778d9a2011-04-29 10:36:31 -040048 ___r; \
49 })
Steven Rostedt6912896e2008-10-23 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 Rostedt6912896e2008-10-23 09:33:03 -040055 ftrace_kill(); \
Steven Rostedt0778d9a2011-04-29 10:36:31 -040056 ___r; \
57 })
Steven Rostedt6912896e2008-10-23 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
Steven Rostedt (Red Hat)4104d322014-01-10 17:01:58 -050065#define FL_GLOBAL_CONTROL_MASK (FTRACE_OPS_FL_CONTROL)
Jiri Olsae2484912012-02-15 15:51:48 +010066
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +090067#ifdef CONFIG_DYNAMIC_FTRACE
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -040068#define INIT_OPS_HASH(opsname) \
69 .func_hash = &opsname.local_hash, \
70 .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
Steven Rostedt (Red Hat)5f151b22014-08-15 17:18:46 -040071#define ASSIGN_OPS_HASH(opsname, val) \
72 .func_hash = val, \
73 .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +090074#else
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -040075#define INIT_OPS_HASH(opsname)
Steven Rostedt (Red Hat)5f151b22014-08-15 17:18:46 -040076#define ASSIGN_OPS_HASH(opsname, val)
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +090077#endif
78
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -040079static struct ftrace_ops ftrace_list_end __read_mostly = {
80 .func = ftrace_stub,
Steven Rostedt (Red Hat)395b97a2013-03-27 09:31:28 -040081 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB,
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -040082 INIT_OPS_HASH(ftrace_list_end)
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -040083};
84
Steven Rostedt4eebcc82008-05-12 21:20:48 +020085/* ftrace_enabled is a method to turn ftrace on or off */
86int ftrace_enabled __read_mostly;
Steven Rostedtd61f82d2008-05-12 21:20:43 +020087static int last_ftrace_enabled;
Steven Rostedtb0fc4942008-05-12 21:20:43 +020088
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -040089/* Current function tracing op */
90struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end;
Steven Rostedt (Red Hat)405e1d82013-11-08 14:17:30 -050091/* What to set function_trace_op to */
92static struct ftrace_ops *set_function_trace_op;
Steven Rostedt60a7ecf2008-11-05 16:05:44 -050093
jolsa@redhat.com756d17e2009-10-13 16:33:52 -040094/* List for set_ftrace_pid's pids. */
95LIST_HEAD(ftrace_pids);
96struct ftrace_pid {
97 struct list_head list;
98 struct pid *pid;
99};
100
Steven Rostedt4eebcc82008-05-12 21:20:48 +0200101/*
102 * ftrace_disabled is set when an anomaly is discovered.
103 * ftrace_disabled is much stronger than ftrace_enabled.
104 */
105static int ftrace_disabled __read_mostly;
106
Steven Rostedt52baf112009-02-14 01:15:39 -0500107static DEFINE_MUTEX(ftrace_lock);
Steven Rostedtb0fc4942008-05-12 21:20:43 +0200108
Jiri Olsae2484912012-02-15 15:51:48 +0100109static struct ftrace_ops *ftrace_control_list __read_mostly = &ftrace_list_end;
Steven Rostedtb8489142011-05-04 09:27:52 -0400110static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end;
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200111ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
Steven Rostedtdf4fc312008-11-26 00:16:23 -0500112ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
Steven Rostedt2b499382011-05-03 22:49:52 -0400113static struct ftrace_ops global_ops;
Jiri Olsae2484912012-02-15 15:51:48 +0100114static struct ftrace_ops control_ops;
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200115
Steven Rostedt (Red Hat)f1ff6342014-07-22 20:16:57 -0400116static void ftrace_ops_recurs_func(unsigned long ip, unsigned long parent_ip,
117 struct ftrace_ops *op, struct pt_regs *regs);
118
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -0400119#if ARCH_SUPPORTS_FTRACE_OPS
120static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
Steven Rostedta1e2e312011-08-09 12:50:46 -0400121 struct ftrace_ops *op, struct pt_regs *regs);
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -0400122#else
123/* See comment below, where ftrace_ops_list_func is defined */
124static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip);
125#define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
126#endif
Steven Rostedtb8489142011-05-04 09:27:52 -0400127
Steven Rostedt0a016402012-11-02 17:03:03 -0400128/*
129 * Traverse the ftrace_global_list, invoking all entries. The reason that we
Steven Rostedt1bb539c2013-05-28 14:38:43 -0400130 * can use rcu_dereference_raw_notrace() is that elements removed from this list
Steven Rostedt0a016402012-11-02 17:03:03 -0400131 * are simply leaked, so there is no need to interact with a grace-period
Steven Rostedt1bb539c2013-05-28 14:38:43 -0400132 * mechanism. The rcu_dereference_raw_notrace() calls are needed to handle
Steven Rostedt0a016402012-11-02 17:03:03 -0400133 * concurrent insertions into the ftrace_global_list.
134 *
135 * Silly Alpha and silly pointer-speculation compiler optimizations!
136 */
137#define do_for_each_ftrace_op(op, list) \
Steven Rostedt1bb539c2013-05-28 14:38:43 -0400138 op = rcu_dereference_raw_notrace(list); \
Steven Rostedt0a016402012-11-02 17:03:03 -0400139 do
140
141/*
142 * Optimized for just a single item in the list (as that is the normal case).
143 */
144#define while_for_each_ftrace_op(op) \
Steven Rostedt1bb539c2013-05-28 14:38:43 -0400145 while (likely(op = rcu_dereference_raw_notrace((op)->next)) && \
Steven Rostedt0a016402012-11-02 17:03:03 -0400146 unlikely((op) != &ftrace_list_end))
147
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +0900148static inline void ftrace_ops_init(struct ftrace_ops *ops)
149{
150#ifdef CONFIG_DYNAMIC_FTRACE
151 if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) {
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -0400152 mutex_init(&ops->local_hash.regex_lock);
153 ops->func_hash = &ops->local_hash;
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +0900154 ops->flags |= FTRACE_OPS_FL_INITIALIZED;
155 }
156#endif
157}
158
Steven Rostedtea701f12012-07-20 13:08:05 -0400159/**
160 * ftrace_nr_registered_ops - return number of ops registered
161 *
162 * Returns the number of ftrace_ops registered and tracing functions
163 */
164int ftrace_nr_registered_ops(void)
165{
166 struct ftrace_ops *ops;
167 int cnt = 0;
168
169 mutex_lock(&ftrace_lock);
170
171 for (ops = ftrace_ops_list;
172 ops != &ftrace_list_end; ops = ops->next)
173 cnt++;
174
175 mutex_unlock(&ftrace_lock);
176
177 return cnt;
178}
179
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -0400180static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
Steven Rostedta1e2e312011-08-09 12:50:46 -0400181 struct ftrace_ops *op, struct pt_regs *regs)
Steven Rostedtdf4fc312008-11-26 00:16:23 -0500182{
Steven Rostedt0ef8cde2008-12-03 15:36:58 -0500183 if (!test_tsk_trace_trace(current))
Steven Rostedtdf4fc312008-11-26 00:16:23 -0500184 return;
185
Steven Rostedta1e2e312011-08-09 12:50:46 -0400186 ftrace_pid_function(ip, parent_ip, op, regs);
Steven Rostedtdf4fc312008-11-26 00:16:23 -0500187}
188
189static void set_ftrace_pid_function(ftrace_func_t func)
190{
191 /* do not set ftrace_pid_function to itself! */
192 if (func != ftrace_pid_func)
193 ftrace_pid_function = func;
194}
195
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200196/**
Steven Rostedt3d083392008-05-12 21:20:42 +0200197 * clear_ftrace_function - reset the ftrace function
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200198 *
Steven Rostedt3d083392008-05-12 21:20:42 +0200199 * This NULLs the ftrace function and in essence stops
200 * tracing. There may be lag
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200201 */
Steven Rostedt3d083392008-05-12 21:20:42 +0200202void clear_ftrace_function(void)
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200203{
Steven Rostedt3d083392008-05-12 21:20:42 +0200204 ftrace_trace_function = ftrace_stub;
Steven Rostedtdf4fc312008-11-26 00:16:23 -0500205 ftrace_pid_function = ftrace_stub;
Steven Rostedt3d083392008-05-12 21:20:42 +0200206}
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200207
Jiri Olsae2484912012-02-15 15:51:48 +0100208static void control_ops_disable_all(struct ftrace_ops *ops)
209{
210 int cpu;
211
212 for_each_possible_cpu(cpu)
213 *per_cpu_ptr(ops->disabled, cpu) = 1;
214}
215
216static int control_ops_alloc(struct ftrace_ops *ops)
217{
218 int __percpu *disabled;
219
220 disabled = alloc_percpu(int);
221 if (!disabled)
222 return -ENOMEM;
223
224 ops->disabled = disabled;
225 control_ops_disable_all(ops);
226 return 0;
227}
228
Steven Rostedt (Red Hat)405e1d82013-11-08 14:17:30 -0500229static void ftrace_sync(struct work_struct *work)
230{
231 /*
232 * This function is just a stub to implement a hard force
233 * of synchronize_sched(). This requires synchronizing
234 * tasks even in userspace and idle.
235 *
236 * Yes, function tracing is rude.
237 */
238}
239
240static void ftrace_sync_ipi(void *data)
241{
242 /* Probably not needed, but do it anyway */
243 smp_rmb();
244}
245
Steven Rostedt (Red Hat)23a8e842014-01-13 10:30:23 -0500246#ifdef CONFIG_FUNCTION_GRAPH_TRACER
247static void update_function_graph_func(void);
248#else
249static inline void update_function_graph_func(void) { }
250#endif
251
Steven Rostedt2b499382011-05-03 22:49:52 -0400252static void update_ftrace_function(void)
253{
254 ftrace_func_t func;
255
Steven Rostedtcdbe61b2011-05-05 21:14:55 -0400256 /*
Steven Rostedt (Red Hat)f7aad4e2014-09-10 10:42:46 -0400257 * Prepare the ftrace_ops that the arch callback will use.
258 * If there's only one ftrace_ops registered, the ftrace_ops_list
259 * will point to the ops we want.
260 */
261 set_function_trace_op = ftrace_ops_list;
262
263 /* If there's no ftrace_ops registered, just call the stub function */
264 if (ftrace_ops_list == &ftrace_list_end) {
265 func = ftrace_stub;
266
267 /*
Steven Rostedtcdbe61b2011-05-05 21:14:55 -0400268 * If we are at the end of the list and this ops is
Steven Rostedt47409742012-07-20 11:04:44 -0400269 * recursion safe and not dynamic and the arch supports passing ops,
270 * then have the mcount trampoline call the function directly.
Steven Rostedtcdbe61b2011-05-05 21:14:55 -0400271 */
Steven Rostedt (Red Hat)f7aad4e2014-09-10 10:42:46 -0400272 } else if (ftrace_ops_list->next == &ftrace_list_end) {
Steven Rostedt (Red Hat)87354052014-07-22 20:41:42 -0400273 func = ftrace_ops_get_func(ftrace_ops_list);
Steven Rostedt (Red Hat)f7aad4e2014-09-10 10:42:46 -0400274
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -0400275 } else {
276 /* Just use the default ftrace_ops */
Steven Rostedt (Red Hat)405e1d82013-11-08 14:17:30 -0500277 set_function_trace_op = &ftrace_list_end;
Steven Rostedtb8489142011-05-04 09:27:52 -0400278 func = ftrace_ops_list_func;
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -0400279 }
Steven Rostedt2b499382011-05-03 22:49:52 -0400280
Steven Rostedt (Red Hat)5f8bf2d22014-07-15 11:05:12 -0400281 update_function_graph_func();
282
Steven Rostedt (Red Hat)405e1d82013-11-08 14:17:30 -0500283 /* If there's no change, then do nothing more here */
284 if (ftrace_trace_function == func)
285 return;
286
287 /*
288 * If we are using the list function, it doesn't care
289 * about the function_trace_ops.
290 */
291 if (func == ftrace_ops_list_func) {
292 ftrace_trace_function = func;
293 /*
294 * Don't even bother setting function_trace_ops,
295 * it would be racy to do so anyway.
296 */
297 return;
298 }
299
300#ifndef CONFIG_DYNAMIC_FTRACE
301 /*
302 * For static tracing, we need to be a bit more careful.
303 * The function change takes affect immediately. Thus,
304 * we need to coorditate the setting of the function_trace_ops
305 * with the setting of the ftrace_trace_function.
306 *
307 * Set the function to the list ops, which will call the
308 * function we want, albeit indirectly, but it handles the
309 * ftrace_ops and doesn't depend on function_trace_op.
310 */
311 ftrace_trace_function = ftrace_ops_list_func;
312 /*
313 * Make sure all CPUs see this. Yes this is slow, but static
314 * tracing is slow and nasty to have enabled.
315 */
316 schedule_on_each_cpu(ftrace_sync);
317 /* Now all cpus are using the list ops. */
318 function_trace_op = set_function_trace_op;
319 /* Make sure the function_trace_op is visible on all CPUs */
320 smp_wmb();
321 /* Nasty way to force a rmb on all cpus */
322 smp_call_function(ftrace_sync_ipi, NULL, 1);
323 /* OK, we are all set to update the ftrace_trace_function now! */
324#endif /* !CONFIG_DYNAMIC_FTRACE */
325
Steven Rostedt491d0dc2011-04-27 21:43:36 -0400326 ftrace_trace_function = func;
Steven Rostedt491d0dc2011-04-27 21:43:36 -0400327}
328
Jiaxing Wang7eea4fc2014-04-20 23:10:43 +0800329int using_ftrace_ops_list_func(void)
330{
331 return ftrace_trace_function == ftrace_ops_list_func;
332}
333
Steven Rostedt2b499382011-05-03 22:49:52 -0400334static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
Steven Rostedt3d083392008-05-12 21:20:42 +0200335{
Steven Rostedt2b499382011-05-03 22:49:52 -0400336 ops->next = *list;
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200337 /*
Steven Rostedtb8489142011-05-04 09:27:52 -0400338 * We are entering ops into the list but another
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200339 * CPU might be walking that list. We need to make sure
340 * the ops->next pointer is valid before another CPU sees
Steven Rostedtb8489142011-05-04 09:27:52 -0400341 * the ops pointer included into the list.
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200342 */
Steven Rostedt2b499382011-05-03 22:49:52 -0400343 rcu_assign_pointer(*list, ops);
344}
Steven Rostedt3d083392008-05-12 21:20:42 +0200345
Steven Rostedt2b499382011-05-03 22:49:52 -0400346static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops)
347{
348 struct ftrace_ops **p;
349
350 /*
351 * If we are removing the last function, then simply point
352 * to the ftrace_stub.
353 */
354 if (*list == ops && ops->next == &ftrace_list_end) {
355 *list = &ftrace_list_end;
356 return 0;
357 }
358
359 for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
360 if (*p == ops)
361 break;
362
363 if (*p != ops)
364 return -1;
365
366 *p = (*p)->next;
367 return 0;
368}
369
Jiri Olsae2484912012-02-15 15:51:48 +0100370static void add_ftrace_list_ops(struct ftrace_ops **list,
371 struct ftrace_ops *main_ops,
372 struct ftrace_ops *ops)
373{
374 int first = *list == &ftrace_list_end;
375 add_ftrace_ops(list, ops);
376 if (first)
377 add_ftrace_ops(&ftrace_ops_list, main_ops);
378}
379
380static int remove_ftrace_list_ops(struct ftrace_ops **list,
381 struct ftrace_ops *main_ops,
382 struct ftrace_ops *ops)
383{
384 int ret = remove_ftrace_ops(list, ops);
385 if (!ret && *list == &ftrace_list_end)
386 ret = remove_ftrace_ops(&ftrace_ops_list, main_ops);
387 return ret;
388}
389
Steven Rostedt2b499382011-05-03 22:49:52 -0400390static int __register_ftrace_function(struct ftrace_ops *ops)
391{
Steven Rostedt (Red Hat)591dffd2014-01-10 16:17:45 -0500392 if (ops->flags & FTRACE_OPS_FL_DELETED)
393 return -EINVAL;
394
Steven Rostedtb8489142011-05-04 09:27:52 -0400395 if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
396 return -EBUSY;
397
Masami Hiramatsu06aeaae2012-09-28 17:15:17 +0900398#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
Steven Rostedt08f6fba2012-04-30 16:20:23 -0400399 /*
400 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
401 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
402 * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
403 */
404 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS &&
405 !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED))
406 return -EINVAL;
407
408 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)
409 ops->flags |= FTRACE_OPS_FL_SAVE_REGS;
410#endif
411
Steven Rostedtcdbe61b2011-05-05 21:14:55 -0400412 if (!core_kernel_data((unsigned long)ops))
413 ops->flags |= FTRACE_OPS_FL_DYNAMIC;
414
Steven Rostedt (Red Hat)4104d322014-01-10 17:01:58 -0500415 if (ops->flags & FTRACE_OPS_FL_CONTROL) {
Jiri Olsae2484912012-02-15 15:51:48 +0100416 if (control_ops_alloc(ops))
417 return -ENOMEM;
418 add_ftrace_list_ops(&ftrace_control_list, &control_ops, ops);
Steven Rostedtb8489142011-05-04 09:27:52 -0400419 } else
420 add_ftrace_ops(&ftrace_ops_list, ops);
421
Steven Rostedt491d0dc2011-04-27 21:43:36 -0400422 if (ftrace_enabled)
423 update_ftrace_function();
Steven Rostedt3d083392008-05-12 21:20:42 +0200424
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200425 return 0;
426}
427
Ingo Molnare309b412008-05-12 21:20:51 +0200428static int __unregister_ftrace_function(struct ftrace_ops *ops)
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200429{
Steven Rostedt2b499382011-05-03 22:49:52 -0400430 int ret;
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200431
Steven Rostedtb8489142011-05-04 09:27:52 -0400432 if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
433 return -EBUSY;
434
Steven Rostedt (Red Hat)4104d322014-01-10 17:01:58 -0500435 if (ops->flags & FTRACE_OPS_FL_CONTROL) {
Jiri Olsae2484912012-02-15 15:51:48 +0100436 ret = remove_ftrace_list_ops(&ftrace_control_list,
437 &control_ops, ops);
Steven Rostedtb8489142011-05-04 09:27:52 -0400438 } else
439 ret = remove_ftrace_ops(&ftrace_ops_list, ops);
440
Steven Rostedt2b499382011-05-03 22:49:52 -0400441 if (ret < 0)
442 return ret;
Steven Rostedtb8489142011-05-04 09:27:52 -0400443
Steven Rostedt491d0dc2011-04-27 21:43:36 -0400444 if (ftrace_enabled)
445 update_ftrace_function();
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +0200446
Steven Rostedte6ea44e2009-02-14 01:42:44 -0500447 return 0;
Steven Rostedt3d083392008-05-12 21:20:42 +0200448}
449
Steven Rostedtdf4fc312008-11-26 00:16:23 -0500450static void ftrace_update_pid_func(void)
451{
Steven Rostedt491d0dc2011-04-27 21:43:36 -0400452 /* Only do something if we are tracing something */
Steven Rostedtdf4fc312008-11-26 00:16:23 -0500453 if (ftrace_trace_function == ftrace_stub)
KOSAKI Motohiro10dd3eb2009-03-06 15:29:04 +0900454 return;
Steven Rostedtdf4fc312008-11-26 00:16:23 -0500455
Steven Rostedt491d0dc2011-04-27 21:43:36 -0400456 update_ftrace_function();
Steven Rostedtdf4fc312008-11-26 00:16:23 -0500457}
458
Steven Rostedt493762f2009-03-23 17:12:36 -0400459#ifdef CONFIG_FUNCTION_PROFILER
460struct ftrace_profile {
461 struct hlist_node node;
462 unsigned long ip;
463 unsigned long counter;
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400464#ifdef CONFIG_FUNCTION_GRAPH_TRACER
465 unsigned long long time;
Chase Douglase330b3b2010-04-26 14:02:05 -0400466 unsigned long long time_squared;
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400467#endif
Steven Rostedt493762f2009-03-23 17:12:36 -0400468};
469
470struct ftrace_profile_page {
471 struct ftrace_profile_page *next;
472 unsigned long index;
473 struct ftrace_profile records[];
474};
475
Steven Rostedtcafb1682009-03-24 20:50:39 -0400476struct ftrace_profile_stat {
477 atomic_t disabled;
478 struct hlist_head *hash;
479 struct ftrace_profile_page *pages;
480 struct ftrace_profile_page *start;
481 struct tracer_stat stat;
482};
483
Steven Rostedt493762f2009-03-23 17:12:36 -0400484#define PROFILE_RECORDS_SIZE \
485 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
486
487#define PROFILES_PER_PAGE \
488 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
489
Steven Rostedtfb9fb012009-03-25 13:26:41 -0400490static int ftrace_profile_enabled __read_mostly;
491
492/* ftrace_profile_lock - synchronize the enable and disable of the profiler */
Steven Rostedt493762f2009-03-23 17:12:36 -0400493static DEFINE_MUTEX(ftrace_profile_lock);
494
Steven Rostedtcafb1682009-03-24 20:50:39 -0400495static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
Steven Rostedt493762f2009-03-23 17:12:36 -0400496
Namhyung Kim20079eb2013-04-10 08:55:50 +0900497#define FTRACE_PROFILE_HASH_BITS 10
498#define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
Steven Rostedt493762f2009-03-23 17:12:36 -0400499
Steven Rostedt493762f2009-03-23 17:12:36 -0400500static void *
501function_stat_next(void *v, int idx)
502{
503 struct ftrace_profile *rec = v;
504 struct ftrace_profile_page *pg;
505
506 pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
507
508 again:
Li Zefan0296e422009-06-26 11:15:37 +0800509 if (idx != 0)
510 rec++;
511
Steven Rostedt493762f2009-03-23 17:12:36 -0400512 if ((void *)rec >= (void *)&pg->records[pg->index]) {
513 pg = pg->next;
514 if (!pg)
515 return NULL;
516 rec = &pg->records[0];
517 if (!rec->counter)
518 goto again;
519 }
520
521 return rec;
522}
523
524static void *function_stat_start(struct tracer_stat *trace)
525{
Steven Rostedtcafb1682009-03-24 20:50:39 -0400526 struct ftrace_profile_stat *stat =
527 container_of(trace, struct ftrace_profile_stat, stat);
528
529 if (!stat || !stat->start)
530 return NULL;
531
532 return function_stat_next(&stat->start->records[0], 0);
Steven Rostedt493762f2009-03-23 17:12:36 -0400533}
534
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400535#ifdef CONFIG_FUNCTION_GRAPH_TRACER
536/* function graph compares on total time */
537static int function_stat_cmp(void *p1, void *p2)
538{
539 struct ftrace_profile *a = p1;
540 struct ftrace_profile *b = p2;
541
542 if (a->time < b->time)
543 return -1;
544 if (a->time > b->time)
545 return 1;
546 else
547 return 0;
548}
549#else
550/* not function graph compares against hits */
Steven Rostedt493762f2009-03-23 17:12:36 -0400551static int function_stat_cmp(void *p1, void *p2)
552{
553 struct ftrace_profile *a = p1;
554 struct ftrace_profile *b = p2;
555
556 if (a->counter < b->counter)
557 return -1;
558 if (a->counter > b->counter)
559 return 1;
560 else
561 return 0;
562}
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400563#endif
Steven Rostedt493762f2009-03-23 17:12:36 -0400564
565static int function_stat_headers(struct seq_file *m)
566{
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400567#ifdef CONFIG_FUNCTION_GRAPH_TRACER
Steven Rostedt34886c82009-03-25 21:00:47 -0400568 seq_printf(m, " Function "
Chase Douglase330b3b2010-04-26 14:02:05 -0400569 "Hit Time Avg s^2\n"
Steven Rostedt34886c82009-03-25 21:00:47 -0400570 " -------- "
Chase Douglase330b3b2010-04-26 14:02:05 -0400571 "--- ---- --- ---\n");
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400572#else
Steven Rostedt493762f2009-03-23 17:12:36 -0400573 seq_printf(m, " Function Hit\n"
574 " -------- ---\n");
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400575#endif
Steven Rostedt493762f2009-03-23 17:12:36 -0400576 return 0;
577}
578
579static int function_stat_show(struct seq_file *m, void *v)
580{
581 struct ftrace_profile *rec = v;
582 char str[KSYM_SYMBOL_LEN];
Li Zefan3aaba202010-08-23 16:50:12 +0800583 int ret = 0;
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400584#ifdef CONFIG_FUNCTION_GRAPH_TRACER
Steven Rostedt34886c82009-03-25 21:00:47 -0400585 static struct trace_seq s;
586 unsigned long long avg;
Chase Douglase330b3b2010-04-26 14:02:05 -0400587 unsigned long long stddev;
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400588#endif
Li Zefan3aaba202010-08-23 16:50:12 +0800589 mutex_lock(&ftrace_profile_lock);
590
591 /* we raced with function_profile_reset() */
592 if (unlikely(rec->counter == 0)) {
593 ret = -EBUSY;
594 goto out;
595 }
Steven Rostedt493762f2009-03-23 17:12:36 -0400596
597 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400598 seq_printf(m, " %-30.30s %10lu", str, rec->counter);
Steven Rostedt493762f2009-03-23 17:12:36 -0400599
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400600#ifdef CONFIG_FUNCTION_GRAPH_TRACER
601 seq_printf(m, " ");
Steven Rostedt34886c82009-03-25 21:00:47 -0400602 avg = rec->time;
603 do_div(avg, rec->counter);
604
Chase Douglase330b3b2010-04-26 14:02:05 -0400605 /* Sample standard deviation (s^2) */
606 if (rec->counter <= 1)
607 stddev = 0;
608 else {
Juri Lelli52d85d72013-06-12 12:03:18 +0200609 /*
610 * Apply Welford's method:
611 * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
612 */
613 stddev = rec->counter * rec->time_squared -
614 rec->time * rec->time;
615
Chase Douglase330b3b2010-04-26 14:02:05 -0400616 /*
617 * Divide only 1000 for ns^2 -> us^2 conversion.
618 * trace_print_graph_duration will divide 1000 again.
619 */
Juri Lelli52d85d72013-06-12 12:03:18 +0200620 do_div(stddev, rec->counter * (rec->counter - 1) * 1000);
Chase Douglase330b3b2010-04-26 14:02:05 -0400621 }
622
Steven Rostedt34886c82009-03-25 21:00:47 -0400623 trace_seq_init(&s);
624 trace_print_graph_duration(rec->time, &s);
625 trace_seq_puts(&s, " ");
626 trace_print_graph_duration(avg, &s);
Chase Douglase330b3b2010-04-26 14:02:05 -0400627 trace_seq_puts(&s, " ");
628 trace_print_graph_duration(stddev, &s);
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400629 trace_print_seq(m, &s);
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400630#endif
631 seq_putc(m, '\n');
Li Zefan3aaba202010-08-23 16:50:12 +0800632out:
633 mutex_unlock(&ftrace_profile_lock);
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400634
Li Zefan3aaba202010-08-23 16:50:12 +0800635 return ret;
Steven Rostedt493762f2009-03-23 17:12:36 -0400636}
637
Steven Rostedtcafb1682009-03-24 20:50:39 -0400638static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
Steven Rostedt493762f2009-03-23 17:12:36 -0400639{
640 struct ftrace_profile_page *pg;
641
Steven Rostedtcafb1682009-03-24 20:50:39 -0400642 pg = stat->pages = stat->start;
Steven Rostedt493762f2009-03-23 17:12:36 -0400643
644 while (pg) {
645 memset(pg->records, 0, PROFILE_RECORDS_SIZE);
646 pg->index = 0;
647 pg = pg->next;
648 }
649
Steven Rostedtcafb1682009-03-24 20:50:39 -0400650 memset(stat->hash, 0,
Steven Rostedt493762f2009-03-23 17:12:36 -0400651 FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
652}
653
Steven Rostedtcafb1682009-03-24 20:50:39 -0400654int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
Steven Rostedt493762f2009-03-23 17:12:36 -0400655{
656 struct ftrace_profile_page *pg;
Steven Rostedt318e0a72009-03-25 20:06:34 -0400657 int functions;
658 int pages;
Steven Rostedt493762f2009-03-23 17:12:36 -0400659 int i;
660
661 /* If we already allocated, do nothing */
Steven Rostedtcafb1682009-03-24 20:50:39 -0400662 if (stat->pages)
Steven Rostedt493762f2009-03-23 17:12:36 -0400663 return 0;
664
Steven Rostedtcafb1682009-03-24 20:50:39 -0400665 stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
666 if (!stat->pages)
Steven Rostedt493762f2009-03-23 17:12:36 -0400667 return -ENOMEM;
668
Steven Rostedt318e0a72009-03-25 20:06:34 -0400669#ifdef CONFIG_DYNAMIC_FTRACE
670 functions = ftrace_update_tot_cnt;
671#else
672 /*
673 * We do not know the number of functions that exist because
674 * dynamic tracing is what counts them. With past experience
675 * we have around 20K functions. That should be more than enough.
676 * It is highly unlikely we will execute every function in
677 * the kernel.
678 */
679 functions = 20000;
680#endif
681
Steven Rostedtcafb1682009-03-24 20:50:39 -0400682 pg = stat->start = stat->pages;
Steven Rostedt493762f2009-03-23 17:12:36 -0400683
Steven Rostedt318e0a72009-03-25 20:06:34 -0400684 pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
685
Namhyung Kim39e30cd2013-04-01 21:46:24 +0900686 for (i = 1; i < pages; i++) {
Steven Rostedt493762f2009-03-23 17:12:36 -0400687 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
Steven Rostedt493762f2009-03-23 17:12:36 -0400688 if (!pg->next)
Steven Rostedt318e0a72009-03-25 20:06:34 -0400689 goto out_free;
Steven Rostedt493762f2009-03-23 17:12:36 -0400690 pg = pg->next;
691 }
692
693 return 0;
Steven Rostedt318e0a72009-03-25 20:06:34 -0400694
695 out_free:
696 pg = stat->start;
697 while (pg) {
698 unsigned long tmp = (unsigned long)pg;
699
700 pg = pg->next;
701 free_page(tmp);
702 }
703
Steven Rostedt318e0a72009-03-25 20:06:34 -0400704 stat->pages = NULL;
705 stat->start = NULL;
706
707 return -ENOMEM;
Steven Rostedt493762f2009-03-23 17:12:36 -0400708}
709
Steven Rostedtcafb1682009-03-24 20:50:39 -0400710static int ftrace_profile_init_cpu(int cpu)
Steven Rostedt493762f2009-03-23 17:12:36 -0400711{
Steven Rostedtcafb1682009-03-24 20:50:39 -0400712 struct ftrace_profile_stat *stat;
Steven Rostedt493762f2009-03-23 17:12:36 -0400713 int size;
714
Steven Rostedtcafb1682009-03-24 20:50:39 -0400715 stat = &per_cpu(ftrace_profile_stats, cpu);
716
717 if (stat->hash) {
Steven Rostedt493762f2009-03-23 17:12:36 -0400718 /* If the profile is already created, simply reset it */
Steven Rostedtcafb1682009-03-24 20:50:39 -0400719 ftrace_profile_reset(stat);
Steven Rostedt493762f2009-03-23 17:12:36 -0400720 return 0;
721 }
722
723 /*
724 * We are profiling all functions, but usually only a few thousand
725 * functions are hit. We'll make a hash of 1024 items.
726 */
727 size = FTRACE_PROFILE_HASH_SIZE;
728
Steven Rostedtcafb1682009-03-24 20:50:39 -0400729 stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL);
Steven Rostedt493762f2009-03-23 17:12:36 -0400730
Steven Rostedtcafb1682009-03-24 20:50:39 -0400731 if (!stat->hash)
Steven Rostedt493762f2009-03-23 17:12:36 -0400732 return -ENOMEM;
733
Steven Rostedt318e0a72009-03-25 20:06:34 -0400734 /* Preallocate the function profiling pages */
Steven Rostedtcafb1682009-03-24 20:50:39 -0400735 if (ftrace_profile_pages_init(stat) < 0) {
736 kfree(stat->hash);
737 stat->hash = NULL;
Steven Rostedt493762f2009-03-23 17:12:36 -0400738 return -ENOMEM;
739 }
740
741 return 0;
742}
743
Steven Rostedtcafb1682009-03-24 20:50:39 -0400744static int ftrace_profile_init(void)
745{
746 int cpu;
747 int ret = 0;
748
Miao Xiec4602c12013-12-16 15:20:01 +0800749 for_each_possible_cpu(cpu) {
Steven Rostedtcafb1682009-03-24 20:50:39 -0400750 ret = ftrace_profile_init_cpu(cpu);
751 if (ret)
752 break;
753 }
754
755 return ret;
756}
757
Steven Rostedt493762f2009-03-23 17:12:36 -0400758/* interrupts must be disabled */
Steven Rostedtcafb1682009-03-24 20:50:39 -0400759static struct ftrace_profile *
760ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
Steven Rostedt493762f2009-03-23 17:12:36 -0400761{
762 struct ftrace_profile *rec;
763 struct hlist_head *hhd;
Steven Rostedt493762f2009-03-23 17:12:36 -0400764 unsigned long key;
765
Namhyung Kim20079eb2013-04-10 08:55:50 +0900766 key = hash_long(ip, FTRACE_PROFILE_HASH_BITS);
Steven Rostedtcafb1682009-03-24 20:50:39 -0400767 hhd = &stat->hash[key];
Steven Rostedt493762f2009-03-23 17:12:36 -0400768
769 if (hlist_empty(hhd))
770 return NULL;
771
Steven Rostedt1bb539c2013-05-28 14:38:43 -0400772 hlist_for_each_entry_rcu_notrace(rec, hhd, node) {
Steven Rostedt493762f2009-03-23 17:12:36 -0400773 if (rec->ip == ip)
774 return rec;
775 }
776
777 return NULL;
778}
779
Steven Rostedtcafb1682009-03-24 20:50:39 -0400780static void ftrace_add_profile(struct ftrace_profile_stat *stat,
781 struct ftrace_profile *rec)
Steven Rostedt493762f2009-03-23 17:12:36 -0400782{
783 unsigned long key;
784
Namhyung Kim20079eb2013-04-10 08:55:50 +0900785 key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS);
Steven Rostedtcafb1682009-03-24 20:50:39 -0400786 hlist_add_head_rcu(&rec->node, &stat->hash[key]);
Steven Rostedt493762f2009-03-23 17:12:36 -0400787}
788
Steven Rostedt318e0a72009-03-25 20:06:34 -0400789/*
790 * The memory is already allocated, this simply finds a new record to use.
791 */
Steven Rostedt493762f2009-03-23 17:12:36 -0400792static struct ftrace_profile *
Steven Rostedt318e0a72009-03-25 20:06:34 -0400793ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
Steven Rostedt493762f2009-03-23 17:12:36 -0400794{
795 struct ftrace_profile *rec = NULL;
796
Steven Rostedt318e0a72009-03-25 20:06:34 -0400797 /* prevent recursion (from NMIs) */
Steven Rostedtcafb1682009-03-24 20:50:39 -0400798 if (atomic_inc_return(&stat->disabled) != 1)
Steven Rostedt493762f2009-03-23 17:12:36 -0400799 goto out;
800
Steven Rostedt493762f2009-03-23 17:12:36 -0400801 /*
Steven Rostedt318e0a72009-03-25 20:06:34 -0400802 * Try to find the function again since an NMI
803 * could have added it
Steven Rostedt493762f2009-03-23 17:12:36 -0400804 */
Steven Rostedtcafb1682009-03-24 20:50:39 -0400805 rec = ftrace_find_profiled_func(stat, ip);
Steven Rostedt493762f2009-03-23 17:12:36 -0400806 if (rec)
Steven Rostedtcafb1682009-03-24 20:50:39 -0400807 goto out;
Steven Rostedt493762f2009-03-23 17:12:36 -0400808
Steven Rostedtcafb1682009-03-24 20:50:39 -0400809 if (stat->pages->index == PROFILES_PER_PAGE) {
810 if (!stat->pages->next)
811 goto out;
812 stat->pages = stat->pages->next;
Steven Rostedt493762f2009-03-23 17:12:36 -0400813 }
814
Steven Rostedtcafb1682009-03-24 20:50:39 -0400815 rec = &stat->pages->records[stat->pages->index++];
Steven Rostedt493762f2009-03-23 17:12:36 -0400816 rec->ip = ip;
Steven Rostedtcafb1682009-03-24 20:50:39 -0400817 ftrace_add_profile(stat, rec);
Steven Rostedt493762f2009-03-23 17:12:36 -0400818
Steven Rostedt493762f2009-03-23 17:12:36 -0400819 out:
Steven Rostedtcafb1682009-03-24 20:50:39 -0400820 atomic_dec(&stat->disabled);
Steven Rostedt493762f2009-03-23 17:12:36 -0400821
822 return rec;
823}
824
Steven Rostedt493762f2009-03-23 17:12:36 -0400825static void
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -0400826function_profile_call(unsigned long ip, unsigned long parent_ip,
Steven Rostedta1e2e312011-08-09 12:50:46 -0400827 struct ftrace_ops *ops, struct pt_regs *regs)
Steven Rostedt493762f2009-03-23 17:12:36 -0400828{
Steven Rostedtcafb1682009-03-24 20:50:39 -0400829 struct ftrace_profile_stat *stat;
Steven Rostedt493762f2009-03-23 17:12:36 -0400830 struct ftrace_profile *rec;
831 unsigned long flags;
Steven Rostedt493762f2009-03-23 17:12:36 -0400832
833 if (!ftrace_profile_enabled)
834 return;
835
Steven Rostedt493762f2009-03-23 17:12:36 -0400836 local_irq_save(flags);
Steven Rostedtcafb1682009-03-24 20:50:39 -0400837
Christoph Lameterbdffd892014-04-29 14:17:40 -0500838 stat = this_cpu_ptr(&ftrace_profile_stats);
Steven Rostedt0f6ce3d2009-06-01 21:51:28 -0400839 if (!stat->hash || !ftrace_profile_enabled)
Steven Rostedtcafb1682009-03-24 20:50:39 -0400840 goto out;
841
842 rec = ftrace_find_profiled_func(stat, ip);
Steven Rostedt493762f2009-03-23 17:12:36 -0400843 if (!rec) {
Steven Rostedt318e0a72009-03-25 20:06:34 -0400844 rec = ftrace_profile_alloc(stat, ip);
Steven Rostedt493762f2009-03-23 17:12:36 -0400845 if (!rec)
846 goto out;
847 }
848
849 rec->counter++;
850 out:
851 local_irq_restore(flags);
852}
853
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400854#ifdef CONFIG_FUNCTION_GRAPH_TRACER
855static int profile_graph_entry(struct ftrace_graph_ent *trace)
856{
Steven Rostedta1e2e312011-08-09 12:50:46 -0400857 function_profile_call(trace->func, 0, NULL, NULL);
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400858 return 1;
859}
860
861static void profile_graph_return(struct ftrace_graph_ret *trace)
862{
Steven Rostedtcafb1682009-03-24 20:50:39 -0400863 struct ftrace_profile_stat *stat;
Steven Rostedta2a16d62009-03-24 23:17:58 -0400864 unsigned long long calltime;
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400865 struct ftrace_profile *rec;
Steven Rostedtcafb1682009-03-24 20:50:39 -0400866 unsigned long flags;
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400867
868 local_irq_save(flags);
Christoph Lameterbdffd892014-04-29 14:17:40 -0500869 stat = this_cpu_ptr(&ftrace_profile_stats);
Steven Rostedt0f6ce3d2009-06-01 21:51:28 -0400870 if (!stat->hash || !ftrace_profile_enabled)
Steven Rostedtcafb1682009-03-24 20:50:39 -0400871 goto out;
872
Steven Rostedt37e44bc2010-04-27 21:04:24 -0400873 /* If the calltime was zero'd ignore it */
874 if (!trace->calltime)
875 goto out;
876
Steven Rostedta2a16d62009-03-24 23:17:58 -0400877 calltime = trace->rettime - trace->calltime;
878
879 if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) {
880 int index;
881
882 index = trace->depth;
883
884 /* Append this call time to the parent time to subtract */
885 if (index)
886 current->ret_stack[index - 1].subtime += calltime;
887
888 if (current->ret_stack[index].subtime < calltime)
889 calltime -= current->ret_stack[index].subtime;
890 else
891 calltime = 0;
892 }
893
Steven Rostedtcafb1682009-03-24 20:50:39 -0400894 rec = ftrace_find_profiled_func(stat, trace->func);
Chase Douglase330b3b2010-04-26 14:02:05 -0400895 if (rec) {
Steven Rostedta2a16d62009-03-24 23:17:58 -0400896 rec->time += calltime;
Chase Douglase330b3b2010-04-26 14:02:05 -0400897 rec->time_squared += calltime * calltime;
898 }
Steven Rostedta2a16d62009-03-24 23:17:58 -0400899
Steven Rostedtcafb1682009-03-24 20:50:39 -0400900 out:
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400901 local_irq_restore(flags);
902}
903
904static int register_ftrace_profiler(void)
905{
906 return register_ftrace_graph(&profile_graph_return,
907 &profile_graph_entry);
908}
909
910static void unregister_ftrace_profiler(void)
911{
912 unregister_ftrace_graph();
913}
914#else
Paul McQuadebd38c0e2011-05-31 20:51:55 +0100915static struct ftrace_ops ftrace_profile_ops __read_mostly = {
Steven Rostedtfb9fb012009-03-25 13:26:41 -0400916 .func = function_profile_call,
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +0900917 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -0400918 INIT_OPS_HASH(ftrace_profile_ops)
Steven Rostedt493762f2009-03-23 17:12:36 -0400919};
920
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400921static int register_ftrace_profiler(void)
922{
923 return register_ftrace_function(&ftrace_profile_ops);
924}
925
926static void unregister_ftrace_profiler(void)
927{
928 unregister_ftrace_function(&ftrace_profile_ops);
929}
930#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
931
Steven Rostedt493762f2009-03-23 17:12:36 -0400932static ssize_t
933ftrace_profile_write(struct file *filp, const char __user *ubuf,
934 size_t cnt, loff_t *ppos)
935{
936 unsigned long val;
Steven Rostedt493762f2009-03-23 17:12:36 -0400937 int ret;
938
Peter Huewe22fe9b52011-06-07 21:58:27 +0200939 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
940 if (ret)
Steven Rostedt493762f2009-03-23 17:12:36 -0400941 return ret;
942
943 val = !!val;
944
945 mutex_lock(&ftrace_profile_lock);
946 if (ftrace_profile_enabled ^ val) {
947 if (val) {
948 ret = ftrace_profile_init();
949 if (ret < 0) {
950 cnt = ret;
951 goto out;
952 }
953
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400954 ret = register_ftrace_profiler();
955 if (ret < 0) {
956 cnt = ret;
957 goto out;
958 }
Steven Rostedt493762f2009-03-23 17:12:36 -0400959 ftrace_profile_enabled = 1;
960 } else {
961 ftrace_profile_enabled = 0;
Steven Rostedt0f6ce3d2009-06-01 21:51:28 -0400962 /*
963 * unregister_ftrace_profiler calls stop_machine
964 * so this acts like an synchronize_sched.
965 */
Steven Rostedt0706f1c2009-03-23 23:12:58 -0400966 unregister_ftrace_profiler();
Steven Rostedt493762f2009-03-23 17:12:36 -0400967 }
968 }
969 out:
970 mutex_unlock(&ftrace_profile_lock);
971
Jiri Olsacf8517c2009-10-23 19:36:16 -0400972 *ppos += cnt;
Steven Rostedt493762f2009-03-23 17:12:36 -0400973
974 return cnt;
975}
976
977static ssize_t
978ftrace_profile_read(struct file *filp, char __user *ubuf,
979 size_t cnt, loff_t *ppos)
980{
Steven Rostedtfb9fb012009-03-25 13:26:41 -0400981 char buf[64]; /* big enough to hold a number */
Steven Rostedt493762f2009-03-23 17:12:36 -0400982 int r;
983
984 r = sprintf(buf, "%u\n", ftrace_profile_enabled);
985 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
986}
987
988static const struct file_operations ftrace_profile_fops = {
989 .open = tracing_open_generic,
990 .read = ftrace_profile_read,
991 .write = ftrace_profile_write,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200992 .llseek = default_llseek,
Steven Rostedt493762f2009-03-23 17:12:36 -0400993};
994
Steven Rostedtcafb1682009-03-24 20:50:39 -0400995/* used to initialize the real stat files */
996static struct tracer_stat function_stats __initdata = {
Steven Rostedtfb9fb012009-03-25 13:26:41 -0400997 .name = "functions",
998 .stat_start = function_stat_start,
999 .stat_next = function_stat_next,
1000 .stat_cmp = function_stat_cmp,
1001 .stat_headers = function_stat_headers,
1002 .stat_show = function_stat_show
Steven Rostedtcafb1682009-03-24 20:50:39 -04001003};
1004
Steven Rostedt6ab5d662009-06-04 00:55:45 -04001005static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
Steven Rostedt493762f2009-03-23 17:12:36 -04001006{
Steven Rostedtcafb1682009-03-24 20:50:39 -04001007 struct ftrace_profile_stat *stat;
Steven Rostedt493762f2009-03-23 17:12:36 -04001008 struct dentry *entry;
Steven Rostedtcafb1682009-03-24 20:50:39 -04001009 char *name;
Steven Rostedt493762f2009-03-23 17:12:36 -04001010 int ret;
Steven Rostedtcafb1682009-03-24 20:50:39 -04001011 int cpu;
Steven Rostedt493762f2009-03-23 17:12:36 -04001012
Steven Rostedtcafb1682009-03-24 20:50:39 -04001013 for_each_possible_cpu(cpu) {
1014 stat = &per_cpu(ftrace_profile_stats, cpu);
1015
1016 /* allocate enough for function name + cpu number */
1017 name = kmalloc(32, GFP_KERNEL);
1018 if (!name) {
1019 /*
1020 * The files created are permanent, if something happens
1021 * we still do not free memory.
1022 */
Steven Rostedtcafb1682009-03-24 20:50:39 -04001023 WARN(1,
1024 "Could not allocate stat file for cpu %d\n",
1025 cpu);
1026 return;
1027 }
1028 stat->stat = function_stats;
1029 snprintf(name, 32, "function%d", cpu);
1030 stat->stat.name = name;
1031 ret = register_stat_tracer(&stat->stat);
1032 if (ret) {
1033 WARN(1,
1034 "Could not register function stat for cpu %d\n",
1035 cpu);
1036 kfree(name);
1037 return;
1038 }
Steven Rostedt493762f2009-03-23 17:12:36 -04001039 }
1040
1041 entry = debugfs_create_file("function_profile_enabled", 0644,
1042 d_tracer, NULL, &ftrace_profile_fops);
1043 if (!entry)
1044 pr_warning("Could not create debugfs "
1045 "'function_profile_enabled' entry\n");
1046}
1047
1048#else /* CONFIG_FUNCTION_PROFILER */
Steven Rostedt6ab5d662009-06-04 00:55:45 -04001049static __init void ftrace_profile_debugfs(struct dentry *d_tracer)
Steven Rostedt493762f2009-03-23 17:12:36 -04001050{
1051}
1052#endif /* CONFIG_FUNCTION_PROFILER */
1053
Ingo Molnar73d3fd92009-02-17 11:48:18 +01001054static struct pid * const ftrace_swapper_pid = &init_struct_pid;
1055
Steven Rostedt3d083392008-05-12 21:20:42 +02001056#ifdef CONFIG_DYNAMIC_FTRACE
Ingo Molnar73d3fd92009-02-17 11:48:18 +01001057
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001058static struct ftrace_ops *removed_ops;
1059
Steven Rostedt (Red Hat)e1effa02014-08-05 17:19:38 -04001060/*
1061 * Set when doing a global update, like enabling all recs or disabling them.
1062 * It is not set when just updating a single ftrace_ops.
1063 */
1064static bool update_all_ops;
1065
Steven Rostedt99ecdc42008-08-15 21:40:05 -04001066#ifndef CONFIG_FTRACE_MCOUNT_RECORD
Steven Rostedtcb7be3b2008-10-23 09:33:05 -04001067# error Dynamic ftrace depends on MCOUNT_RECORD
Steven Rostedt99ecdc42008-08-15 21:40:05 -04001068#endif
1069
Steven Rostedt8fc0c702009-02-16 15:28:00 -05001070static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly;
1071
Steven Rostedtb6887d72009-02-17 12:32:04 -05001072struct ftrace_func_probe {
Steven Rostedt8fc0c702009-02-16 15:28:00 -05001073 struct hlist_node node;
Steven Rostedtb6887d72009-02-17 12:32:04 -05001074 struct ftrace_probe_ops *ops;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05001075 unsigned long flags;
1076 unsigned long ip;
1077 void *data;
Steven Rostedt (Red Hat)7818b382013-03-13 12:42:58 -04001078 struct list_head free_list;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05001079};
1080
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001081struct ftrace_func_entry {
1082 struct hlist_node hlist;
1083 unsigned long ip;
1084};
1085
1086struct ftrace_hash {
1087 unsigned long size_bits;
1088 struct hlist_head *buckets;
1089 unsigned long count;
Steven Rostedt07fd5512011-05-05 18:03:47 -04001090 struct rcu_head rcu;
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001091};
1092
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001093/*
1094 * We make these constant because no one should touch them,
1095 * but they are used as the default "empty hash", to avoid allocating
1096 * it all the time. These are in a read only section such that if
1097 * anyone does try to modify it, it will cause an exception.
1098 */
1099static const struct hlist_head empty_buckets[1];
1100static const struct ftrace_hash empty_hash = {
1101 .buckets = (struct hlist_head *)empty_buckets,
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001102};
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001103#define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
Steven Rostedt5072c592008-05-12 21:20:43 +02001104
Steven Rostedt2b499382011-05-03 22:49:52 -04001105static struct ftrace_ops global_ops = {
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04001106 .func = ftrace_stub,
1107 .local_hash.notrace_hash = EMPTY_HASH,
1108 .local_hash.filter_hash = EMPTY_HASH,
1109 INIT_OPS_HASH(global_ops)
1110 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
1111 FTRACE_OPS_FL_INITIALIZED,
Steven Rostedtf45948e2011-05-02 12:29:25 -04001112};
1113
Steven Rostedt3c1720f2008-05-12 21:20:43 +02001114struct ftrace_page {
1115 struct ftrace_page *next;
Steven Rostedta7900872011-12-16 16:23:44 -05001116 struct dyn_ftrace *records;
Steven Rostedt431aa3f2009-01-06 12:43:01 -05001117 int index;
Steven Rostedta7900872011-12-16 16:23:44 -05001118 int size;
David Milleraa5e5ce2008-05-13 22:06:56 -07001119};
Steven Rostedt3c1720f2008-05-12 21:20:43 +02001120
Steven Rostedta7900872011-12-16 16:23:44 -05001121#define ENTRY_SIZE sizeof(struct dyn_ftrace)
1122#define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
Steven Rostedt3c1720f2008-05-12 21:20:43 +02001123
1124/* estimate from running different kernels */
1125#define NR_TO_INIT 10000
1126
1127static struct ftrace_page *ftrace_pages_start;
1128static struct ftrace_page *ftrace_pages;
1129
Steven Rostedt (Red Hat)68f40962014-05-01 12:44:50 -04001130static bool __always_inline ftrace_hash_empty(struct ftrace_hash *hash)
Steven Rostedt06a51d92011-12-19 19:07:36 -05001131{
1132 return !hash || !hash->count;
1133}
1134
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001135static struct ftrace_func_entry *
1136ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1137{
1138 unsigned long key;
1139 struct ftrace_func_entry *entry;
1140 struct hlist_head *hhd;
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001141
Steven Rostedt06a51d92011-12-19 19:07:36 -05001142 if (ftrace_hash_empty(hash))
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001143 return NULL;
1144
1145 if (hash->size_bits > 0)
1146 key = hash_long(ip, hash->size_bits);
1147 else
1148 key = 0;
1149
1150 hhd = &hash->buckets[key];
1151
Steven Rostedt1bb539c2013-05-28 14:38:43 -04001152 hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) {
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001153 if (entry->ip == ip)
1154 return entry;
1155 }
1156 return NULL;
1157}
1158
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001159static void __add_hash_entry(struct ftrace_hash *hash,
1160 struct ftrace_func_entry *entry)
1161{
1162 struct hlist_head *hhd;
1163 unsigned long key;
1164
1165 if (hash->size_bits)
1166 key = hash_long(entry->ip, hash->size_bits);
1167 else
1168 key = 0;
1169
1170 hhd = &hash->buckets[key];
1171 hlist_add_head(&entry->hlist, hhd);
1172 hash->count++;
1173}
1174
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001175static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
1176{
1177 struct ftrace_func_entry *entry;
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001178
1179 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1180 if (!entry)
1181 return -ENOMEM;
1182
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001183 entry->ip = ip;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001184 __add_hash_entry(hash, entry);
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001185
1186 return 0;
1187}
1188
1189static void
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001190free_hash_entry(struct ftrace_hash *hash,
1191 struct ftrace_func_entry *entry)
1192{
1193 hlist_del(&entry->hlist);
1194 kfree(entry);
1195 hash->count--;
1196}
1197
1198static void
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001199remove_hash_entry(struct ftrace_hash *hash,
1200 struct ftrace_func_entry *entry)
1201{
1202 hlist_del(&entry->hlist);
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001203 hash->count--;
1204}
1205
1206static void ftrace_hash_clear(struct ftrace_hash *hash)
1207{
1208 struct hlist_head *hhd;
Sasha Levinb67bfe02013-02-27 17:06:00 -08001209 struct hlist_node *tn;
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001210 struct ftrace_func_entry *entry;
1211 int size = 1 << hash->size_bits;
1212 int i;
1213
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001214 if (!hash->count)
1215 return;
1216
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001217 for (i = 0; i < size; i++) {
1218 hhd = &hash->buckets[i];
Sasha Levinb67bfe02013-02-27 17:06:00 -08001219 hlist_for_each_entry_safe(entry, tn, hhd, hlist)
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001220 free_hash_entry(hash, entry);
Steven Rostedtb448c4e2011-04-29 15:12:32 -04001221 }
1222 FTRACE_WARN_ON(hash->count);
1223}
1224
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001225static void free_ftrace_hash(struct ftrace_hash *hash)
1226{
1227 if (!hash || hash == EMPTY_HASH)
1228 return;
1229 ftrace_hash_clear(hash);
1230 kfree(hash->buckets);
1231 kfree(hash);
1232}
1233
Steven Rostedt07fd5512011-05-05 18:03:47 -04001234static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
1235{
1236 struct ftrace_hash *hash;
1237
1238 hash = container_of(rcu, struct ftrace_hash, rcu);
1239 free_ftrace_hash(hash);
1240}
1241
1242static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
1243{
1244 if (!hash || hash == EMPTY_HASH)
1245 return;
1246 call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu);
1247}
1248
Jiri Olsa5500fa52012-02-15 15:51:54 +01001249void ftrace_free_filter(struct ftrace_ops *ops)
1250{
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +09001251 ftrace_ops_init(ops);
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04001252 free_ftrace_hash(ops->func_hash->filter_hash);
1253 free_ftrace_hash(ops->func_hash->notrace_hash);
Jiri Olsa5500fa52012-02-15 15:51:54 +01001254}
1255
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001256static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
1257{
1258 struct ftrace_hash *hash;
1259 int size;
1260
1261 hash = kzalloc(sizeof(*hash), GFP_KERNEL);
1262 if (!hash)
1263 return NULL;
1264
1265 size = 1 << size_bits;
Thomas Meyer47b0edc2011-11-29 22:08:00 +01001266 hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL);
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001267
1268 if (!hash->buckets) {
1269 kfree(hash);
1270 return NULL;
1271 }
1272
1273 hash->size_bits = size_bits;
1274
1275 return hash;
1276}
1277
1278static struct ftrace_hash *
1279alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
1280{
1281 struct ftrace_func_entry *entry;
1282 struct ftrace_hash *new_hash;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001283 int size;
1284 int ret;
1285 int i;
1286
1287 new_hash = alloc_ftrace_hash(size_bits);
1288 if (!new_hash)
1289 return NULL;
1290
1291 /* Empty hash? */
Steven Rostedt06a51d92011-12-19 19:07:36 -05001292 if (ftrace_hash_empty(hash))
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001293 return new_hash;
1294
1295 size = 1 << hash->size_bits;
1296 for (i = 0; i < size; i++) {
Sasha Levinb67bfe02013-02-27 17:06:00 -08001297 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001298 ret = add_hash_entry(new_hash, entry->ip);
1299 if (ret < 0)
1300 goto free_hash;
1301 }
1302 }
1303
1304 FTRACE_WARN_ON(new_hash->count != hash->count);
1305
1306 return new_hash;
1307
1308 free_hash:
1309 free_ftrace_hash(new_hash);
1310 return NULL;
1311}
1312
Steven Rostedt41fb61c2011-07-13 15:03:44 -04001313static void
Steven Rostedt (Red Hat)84261912014-08-18 13:21:08 -04001314ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash);
Steven Rostedt41fb61c2011-07-13 15:03:44 -04001315static void
Steven Rostedt (Red Hat)84261912014-08-18 13:21:08 -04001316ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash);
Steven Rostedt41fb61c2011-07-13 15:03:44 -04001317
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001318static int
Steven Rostedt41fb61c2011-07-13 15:03:44 -04001319ftrace_hash_move(struct ftrace_ops *ops, int enable,
1320 struct ftrace_hash **dst, struct ftrace_hash *src)
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001321{
1322 struct ftrace_func_entry *entry;
Sasha Levinb67bfe02013-02-27 17:06:00 -08001323 struct hlist_node *tn;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001324 struct hlist_head *hhd;
Steven Rostedt07fd5512011-05-05 18:03:47 -04001325 struct ftrace_hash *new_hash;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001326 int size = src->count;
1327 int bits = 0;
1328 int i;
1329
1330 /*
1331 * If the new source is empty, just free dst and assign it
1332 * the empty_hash.
1333 */
1334 if (!src->count) {
Masami Hiramatsu5c27c772014-06-17 11:04:42 +00001335 new_hash = EMPTY_HASH;
1336 goto update;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001337 }
1338
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001339 /*
1340 * Make the hash size about 1/2 the # found
1341 */
1342 for (size /= 2; size; size >>= 1)
1343 bits++;
1344
1345 /* Don't allocate too much */
1346 if (bits > FTRACE_HASH_MAX_BITS)
1347 bits = FTRACE_HASH_MAX_BITS;
1348
Steven Rostedt07fd5512011-05-05 18:03:47 -04001349 new_hash = alloc_ftrace_hash(bits);
1350 if (!new_hash)
Masami Hiramatsu5c27c772014-06-17 11:04:42 +00001351 return -ENOMEM;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001352
1353 size = 1 << src->size_bits;
1354 for (i = 0; i < size; i++) {
1355 hhd = &src->buckets[i];
Sasha Levinb67bfe02013-02-27 17:06:00 -08001356 hlist_for_each_entry_safe(entry, tn, hhd, hlist) {
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001357 remove_hash_entry(src, entry);
Steven Rostedt07fd5512011-05-05 18:03:47 -04001358 __add_hash_entry(new_hash, entry);
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001359 }
1360 }
1361
Masami Hiramatsu5c27c772014-06-17 11:04:42 +00001362update:
1363 /*
1364 * Remove the current set, update the hash and add
1365 * them back.
1366 */
Steven Rostedt (Red Hat)84261912014-08-18 13:21:08 -04001367 ftrace_hash_rec_disable_modify(ops, enable);
Masami Hiramatsu5c27c772014-06-17 11:04:42 +00001368
Steven Rostedt07fd5512011-05-05 18:03:47 -04001369 rcu_assign_pointer(*dst, new_hash);
Steven Rostedt07fd5512011-05-05 18:03:47 -04001370
Steven Rostedt (Red Hat)84261912014-08-18 13:21:08 -04001371 ftrace_hash_rec_enable_modify(ops, enable);
Steven Rostedt41fb61c2011-07-13 15:03:44 -04001372
Masami Hiramatsu5c27c772014-06-17 11:04:42 +00001373 return 0;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04001374}
1375
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04001376static bool hash_contains_ip(unsigned long ip,
1377 struct ftrace_ops_hash *hash)
1378{
1379 /*
1380 * The function record is a match if it exists in the filter
1381 * hash and not in the notrace hash. Note, an emty hash is
1382 * considered a match for the filter hash, but an empty
1383 * notrace hash is considered not in the notrace hash.
1384 */
1385 return (ftrace_hash_empty(hash->filter_hash) ||
1386 ftrace_lookup_ip(hash->filter_hash, ip)) &&
1387 (ftrace_hash_empty(hash->notrace_hash) ||
1388 !ftrace_lookup_ip(hash->notrace_hash, ip));
1389}
1390
Steven Rostedt265c8312009-02-13 12:43:56 -05001391/*
Steven Rostedtb8489142011-05-04 09:27:52 -04001392 * Test the hashes for this ops to see if we want to call
1393 * the ops->func or not.
1394 *
1395 * It's a match if the ip is in the ops->filter_hash or
1396 * the filter_hash does not exist or is empty,
1397 * AND
1398 * the ip is not in the ops->notrace_hash.
Steven Rostedtcdbe61b2011-05-05 21:14:55 -04001399 *
1400 * This needs to be called with preemption disabled as
1401 * the hashes are freed with call_rcu_sched().
Steven Rostedtb8489142011-05-04 09:27:52 -04001402 */
1403static int
Steven Rostedt (Red Hat)195a8af2013-07-23 22:06:15 -04001404ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
Steven Rostedtb8489142011-05-04 09:27:52 -04001405{
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04001406 struct ftrace_ops_hash hash;
Steven Rostedtb8489142011-05-04 09:27:52 -04001407 int ret;
1408
Steven Rostedt (Red Hat)195a8af2013-07-23 22:06:15 -04001409#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
1410 /*
1411 * There's a small race when adding ops that the ftrace handler
1412 * that wants regs, may be called without them. We can not
1413 * allow that handler to be called if regs is NULL.
1414 */
1415 if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS))
1416 return 0;
1417#endif
1418
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04001419 hash.filter_hash = rcu_dereference_raw_notrace(ops->func_hash->filter_hash);
1420 hash.notrace_hash = rcu_dereference_raw_notrace(ops->func_hash->notrace_hash);
Steven Rostedtb8489142011-05-04 09:27:52 -04001421
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04001422 if (hash_contains_ip(ip, &hash))
Steven Rostedtb8489142011-05-04 09:27:52 -04001423 ret = 1;
1424 else
1425 ret = 0;
Steven Rostedtb8489142011-05-04 09:27:52 -04001426
1427 return ret;
1428}
1429
1430/*
Steven Rostedt265c8312009-02-13 12:43:56 -05001431 * This is a double for. Do not use 'break' to break out of the loop,
1432 * you must use a goto.
1433 */
1434#define do_for_each_ftrace_rec(pg, rec) \
1435 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1436 int _____i; \
1437 for (_____i = 0; _____i < pg->index; _____i++) { \
1438 rec = &pg->records[_____i];
1439
1440#define while_for_each_ftrace_rec() \
1441 } \
1442 }
Abhishek Sagarecea6562008-06-21 23:47:53 +05301443
Steven Rostedt5855fea2011-12-16 19:27:42 -05001444
1445static int ftrace_cmp_recs(const void *a, const void *b)
1446{
Steven Rostedta650e022012-04-25 13:48:13 -04001447 const struct dyn_ftrace *key = a;
1448 const struct dyn_ftrace *rec = b;
Steven Rostedt5855fea2011-12-16 19:27:42 -05001449
Steven Rostedta650e022012-04-25 13:48:13 -04001450 if (key->flags < rec->ip)
Steven Rostedt5855fea2011-12-16 19:27:42 -05001451 return -1;
Steven Rostedta650e022012-04-25 13:48:13 -04001452 if (key->ip >= rec->ip + MCOUNT_INSN_SIZE)
1453 return 1;
1454 return 0;
1455}
1456
Steven Rostedtf0cf9732012-04-25 14:39:54 -04001457static unsigned long ftrace_location_range(unsigned long start, unsigned long end)
Steven Rostedta650e022012-04-25 13:48:13 -04001458{
1459 struct ftrace_page *pg;
1460 struct dyn_ftrace *rec;
1461 struct dyn_ftrace key;
1462
1463 key.ip = start;
1464 key.flags = end; /* overload flags, as it is unsigned long */
1465
1466 for (pg = ftrace_pages_start; pg; pg = pg->next) {
1467 if (end < pg->records[0].ip ||
1468 start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
1469 continue;
1470 rec = bsearch(&key, pg->records, pg->index,
1471 sizeof(struct dyn_ftrace),
1472 ftrace_cmp_recs);
1473 if (rec)
Steven Rostedtf0cf9732012-04-25 14:39:54 -04001474 return rec->ip;
Steven Rostedta650e022012-04-25 13:48:13 -04001475 }
1476
Steven Rostedt5855fea2011-12-16 19:27:42 -05001477 return 0;
1478}
1479
Steven Rostedtc88fd862011-08-16 09:53:39 -04001480/**
1481 * ftrace_location - return true if the ip giving is a traced location
1482 * @ip: the instruction pointer to check
1483 *
Steven Rostedtf0cf9732012-04-25 14:39:54 -04001484 * Returns rec->ip if @ip given is a pointer to a ftrace location.
Steven Rostedtc88fd862011-08-16 09:53:39 -04001485 * That is, the instruction that is either a NOP or call to
1486 * the function tracer. It checks the ftrace internal tables to
1487 * determine if the address belongs or not.
1488 */
Steven Rostedtf0cf9732012-04-25 14:39:54 -04001489unsigned long ftrace_location(unsigned long ip)
Steven Rostedtc88fd862011-08-16 09:53:39 -04001490{
Steven Rostedta650e022012-04-25 13:48:13 -04001491 return ftrace_location_range(ip, ip);
1492}
Steven Rostedtc88fd862011-08-16 09:53:39 -04001493
Steven Rostedta650e022012-04-25 13:48:13 -04001494/**
1495 * ftrace_text_reserved - return true if range contains an ftrace location
1496 * @start: start of range to search
1497 * @end: end of range to search (inclusive). @end points to the last byte to check.
1498 *
1499 * Returns 1 if @start and @end contains a ftrace location.
1500 * That is, the instruction that is either a NOP or call to
1501 * the function tracer. It checks the ftrace internal tables to
1502 * determine if the address belongs or not.
1503 */
Sasha Levind88471c2013-01-09 18:09:20 -05001504int ftrace_text_reserved(const void *start, const void *end)
Steven Rostedta650e022012-04-25 13:48:13 -04001505{
Steven Rostedtf0cf9732012-04-25 14:39:54 -04001506 unsigned long ret;
1507
1508 ret = ftrace_location_range((unsigned long)start,
1509 (unsigned long)end);
1510
1511 return (int)!!ret;
Steven Rostedtc88fd862011-08-16 09:53:39 -04001512}
1513
Steven Rostedt (Red Hat)4fbb48c2014-04-30 22:35:48 -04001514/* Test if ops registered to this rec needs regs */
1515static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec)
1516{
1517 struct ftrace_ops *ops;
1518 bool keep_regs = false;
1519
1520 for (ops = ftrace_ops_list;
1521 ops != &ftrace_list_end; ops = ops->next) {
1522 /* pass rec in as regs to have non-NULL val */
1523 if (ftrace_ops_test(ops, rec->ip, rec)) {
1524 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1525 keep_regs = true;
1526 break;
1527 }
1528 }
1529 }
1530
1531 return keep_regs;
1532}
1533
Steven Rostedted926f92011-05-03 13:25:24 -04001534static void __ftrace_hash_rec_update(struct ftrace_ops *ops,
1535 int filter_hash,
1536 bool inc)
1537{
1538 struct ftrace_hash *hash;
1539 struct ftrace_hash *other_hash;
1540 struct ftrace_page *pg;
1541 struct dyn_ftrace *rec;
1542 int count = 0;
1543 int all = 0;
1544
1545 /* Only update if the ops has been registered */
1546 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1547 return;
1548
1549 /*
1550 * In the filter_hash case:
1551 * If the count is zero, we update all records.
1552 * Otherwise we just update the items in the hash.
1553 *
1554 * In the notrace_hash case:
1555 * We enable the update in the hash.
1556 * As disabling notrace means enabling the tracing,
1557 * and enabling notrace means disabling, the inc variable
1558 * gets inversed.
1559 */
1560 if (filter_hash) {
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04001561 hash = ops->func_hash->filter_hash;
1562 other_hash = ops->func_hash->notrace_hash;
Steven Rostedt06a51d92011-12-19 19:07:36 -05001563 if (ftrace_hash_empty(hash))
Steven Rostedted926f92011-05-03 13:25:24 -04001564 all = 1;
1565 } else {
1566 inc = !inc;
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04001567 hash = ops->func_hash->notrace_hash;
1568 other_hash = ops->func_hash->filter_hash;
Steven Rostedted926f92011-05-03 13:25:24 -04001569 /*
1570 * If the notrace hash has no items,
1571 * then there's nothing to do.
1572 */
Steven Rostedt06a51d92011-12-19 19:07:36 -05001573 if (ftrace_hash_empty(hash))
Steven Rostedted926f92011-05-03 13:25:24 -04001574 return;
1575 }
1576
1577 do_for_each_ftrace_rec(pg, rec) {
1578 int in_other_hash = 0;
1579 int in_hash = 0;
1580 int match = 0;
1581
1582 if (all) {
1583 /*
1584 * Only the filter_hash affects all records.
1585 * Update if the record is not in the notrace hash.
1586 */
Steven Rostedtb8489142011-05-04 09:27:52 -04001587 if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
Steven Rostedted926f92011-05-03 13:25:24 -04001588 match = 1;
1589 } else {
Steven Rostedt06a51d92011-12-19 19:07:36 -05001590 in_hash = !!ftrace_lookup_ip(hash, rec->ip);
1591 in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip);
Steven Rostedted926f92011-05-03 13:25:24 -04001592
1593 /*
Steven Rostedt (Red Hat)19eab4a2014-05-07 15:06:14 -04001594 * If filter_hash is set, we want to match all functions
1595 * that are in the hash but not in the other hash.
Steven Rostedted926f92011-05-03 13:25:24 -04001596 *
Steven Rostedt (Red Hat)19eab4a2014-05-07 15:06:14 -04001597 * If filter_hash is not set, then we are decrementing.
1598 * That means we match anything that is in the hash
1599 * and also in the other_hash. That is, we need to turn
1600 * off functions in the other hash because they are disabled
1601 * by this hash.
Steven Rostedted926f92011-05-03 13:25:24 -04001602 */
1603 if (filter_hash && in_hash && !in_other_hash)
1604 match = 1;
1605 else if (!filter_hash && in_hash &&
Steven Rostedt06a51d92011-12-19 19:07:36 -05001606 (in_other_hash || ftrace_hash_empty(other_hash)))
Steven Rostedted926f92011-05-03 13:25:24 -04001607 match = 1;
1608 }
1609 if (!match)
1610 continue;
1611
1612 if (inc) {
1613 rec->flags++;
Steven Rostedt (Red Hat)0376bde2014-05-07 13:46:45 -04001614 if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX))
Steven Rostedted926f92011-05-03 13:25:24 -04001615 return;
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001616
1617 /*
1618 * If there's only a single callback registered to a
1619 * function, and the ops has a trampoline registered
1620 * for it, then we can call it directly.
1621 */
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04001622 if (ftrace_rec_count(rec) == 1 && ops->trampoline)
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001623 rec->flags |= FTRACE_FL_TRAMP;
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04001624 else
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001625 /*
1626 * If we are adding another function callback
1627 * to this function, and the previous had a
Steven Rostedt (Red Hat)bce0b6c2014-08-20 23:57:04 -04001628 * custom trampoline in use, then we need to go
1629 * back to the default trampoline.
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001630 */
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04001631 rec->flags &= ~FTRACE_FL_TRAMP;
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001632
Steven Rostedt08f6fba2012-04-30 16:20:23 -04001633 /*
1634 * If any ops wants regs saved for this function
1635 * then all ops will get saved regs.
1636 */
1637 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
1638 rec->flags |= FTRACE_FL_REGS;
Steven Rostedted926f92011-05-03 13:25:24 -04001639 } else {
Steven Rostedt (Red Hat)0376bde2014-05-07 13:46:45 -04001640 if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0))
Steven Rostedted926f92011-05-03 13:25:24 -04001641 return;
1642 rec->flags--;
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001643
Steven Rostedt (Red Hat)4fbb48c2014-04-30 22:35:48 -04001644 /*
1645 * If the rec had REGS enabled and the ops that is
1646 * being removed had REGS set, then see if there is
1647 * still any ops for this record that wants regs.
1648 * If not, we can stop recording them.
1649 */
Steven Rostedt (Red Hat)0376bde2014-05-07 13:46:45 -04001650 if (ftrace_rec_count(rec) > 0 &&
Steven Rostedt (Red Hat)4fbb48c2014-04-30 22:35:48 -04001651 rec->flags & FTRACE_FL_REGS &&
1652 ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1653 if (!test_rec_ops_needs_regs(rec))
1654 rec->flags &= ~FTRACE_FL_REGS;
1655 }
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001656
1657 /*
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04001658 * If the rec had TRAMP enabled, then it needs to
1659 * be cleared. As TRAMP can only be enabled iff
1660 * there is only a single ops attached to it.
1661 * In otherwords, always disable it on decrementing.
1662 * In the future, we may set it if rec count is
1663 * decremented to one, and the ops that is left
1664 * has a trampoline.
1665 */
1666 rec->flags &= ~FTRACE_FL_TRAMP;
1667
1668 /*
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001669 * flags will be cleared in ftrace_check_record()
1670 * if rec count is zero.
1671 */
Steven Rostedted926f92011-05-03 13:25:24 -04001672 }
1673 count++;
1674 /* Shortcut, if we handled all records, we are done. */
1675 if (!all && count == hash->count)
1676 return;
1677 } while_for_each_ftrace_rec();
1678}
1679
1680static void ftrace_hash_rec_disable(struct ftrace_ops *ops,
1681 int filter_hash)
1682{
1683 __ftrace_hash_rec_update(ops, filter_hash, 0);
1684}
1685
1686static void ftrace_hash_rec_enable(struct ftrace_ops *ops,
1687 int filter_hash)
1688{
1689 __ftrace_hash_rec_update(ops, filter_hash, 1);
1690}
1691
Steven Rostedt (Red Hat)84261912014-08-18 13:21:08 -04001692static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops,
1693 int filter_hash, int inc)
1694{
1695 struct ftrace_ops *op;
1696
1697 __ftrace_hash_rec_update(ops, filter_hash, inc);
1698
1699 if (ops->func_hash != &global_ops.local_hash)
1700 return;
1701
1702 /*
1703 * If the ops shares the global_ops hash, then we need to update
1704 * all ops that are enabled and use this hash.
1705 */
1706 do_for_each_ftrace_op(op, ftrace_ops_list) {
1707 /* Already done */
1708 if (op == ops)
1709 continue;
1710 if (op->func_hash == &global_ops.local_hash)
1711 __ftrace_hash_rec_update(op, filter_hash, inc);
1712 } while_for_each_ftrace_op(op);
1713}
1714
1715static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops,
1716 int filter_hash)
1717{
1718 ftrace_hash_rec_update_modify(ops, filter_hash, 0);
1719}
1720
1721static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops,
1722 int filter_hash)
1723{
1724 ftrace_hash_rec_update_modify(ops, filter_hash, 1);
1725}
1726
Steven Rostedt05736a42008-09-22 14:55:47 -07001727static void print_ip_ins(const char *fmt, unsigned char *p)
1728{
1729 int i;
1730
1731 printk(KERN_CONT "%s", fmt);
1732
1733 for (i = 0; i < MCOUNT_INSN_SIZE; i++)
1734 printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
1735}
1736
Steven Rostedtc88fd862011-08-16 09:53:39 -04001737/**
1738 * ftrace_bug - report and shutdown function tracer
1739 * @failed: The failed type (EFAULT, EINVAL, EPERM)
1740 * @ip: The address that failed
1741 *
1742 * The arch code that enables or disables the function tracing
1743 * can call ftrace_bug() when it has detected a problem in
1744 * modifying the code. @failed should be one of either:
1745 * EFAULT - if the problem happens on reading the @ip address
1746 * EINVAL - if what is read at @ip is not what was expected
1747 * EPERM - if the problem happens on writting to the @ip address
1748 */
1749void ftrace_bug(int failed, unsigned long ip)
Steven Rostedtb17e8a32008-11-14 16:21:19 -08001750{
1751 switch (failed) {
1752 case -EFAULT:
1753 FTRACE_WARN_ON_ONCE(1);
1754 pr_info("ftrace faulted on modifying ");
1755 print_ip_sym(ip);
1756 break;
1757 case -EINVAL:
1758 FTRACE_WARN_ON_ONCE(1);
1759 pr_info("ftrace failed to modify ");
1760 print_ip_sym(ip);
Steven Rostedtb17e8a32008-11-14 16:21:19 -08001761 print_ip_ins(" actual: ", (unsigned char *)ip);
Steven Rostedtb17e8a32008-11-14 16:21:19 -08001762 printk(KERN_CONT "\n");
1763 break;
1764 case -EPERM:
1765 FTRACE_WARN_ON_ONCE(1);
1766 pr_info("ftrace faulted on writing ");
1767 print_ip_sym(ip);
1768 break;
1769 default:
1770 FTRACE_WARN_ON_ONCE(1);
1771 pr_info("ftrace faulted on unknown error ");
1772 print_ip_sym(ip);
1773 }
1774}
1775
Steven Rostedtc88fd862011-08-16 09:53:39 -04001776static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
Steven Rostedt5072c592008-05-12 21:20:43 +02001777{
Xiao Guangrong64fbcd12009-07-15 12:32:15 +08001778 unsigned long flag = 0UL;
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01001779
Steven Rostedt982c3502008-11-15 16:31:41 -05001780 /*
Jiri Olsa30fb6aa2011-12-05 18:22:48 +01001781 * If we are updating calls:
Steven Rostedt982c3502008-11-15 16:31:41 -05001782 *
Steven Rostedted926f92011-05-03 13:25:24 -04001783 * If the record has a ref count, then we need to enable it
1784 * because someone is using it.
Steven Rostedt982c3502008-11-15 16:31:41 -05001785 *
Steven Rostedted926f92011-05-03 13:25:24 -04001786 * Otherwise we make sure its disabled.
1787 *
Jiri Olsa30fb6aa2011-12-05 18:22:48 +01001788 * If we are disabling calls, then disable all records that
Steven Rostedted926f92011-05-03 13:25:24 -04001789 * are enabled.
Steven Rostedt982c3502008-11-15 16:31:41 -05001790 */
Steven Rostedt (Red Hat)0376bde2014-05-07 13:46:45 -04001791 if (enable && ftrace_rec_count(rec))
Steven Rostedted926f92011-05-03 13:25:24 -04001792 flag = FTRACE_FL_ENABLED;
Steven Rostedt5072c592008-05-12 21:20:43 +02001793
Steven Rostedt08f6fba2012-04-30 16:20:23 -04001794 /*
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001795 * If enabling and the REGS flag does not match the REGS_EN, or
1796 * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
1797 * this record. Set flags to fail the compare against ENABLED.
Steven Rostedt08f6fba2012-04-30 16:20:23 -04001798 */
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001799 if (flag) {
1800 if (!(rec->flags & FTRACE_FL_REGS) !=
1801 !(rec->flags & FTRACE_FL_REGS_EN))
1802 flag |= FTRACE_FL_REGS;
1803
1804 if (!(rec->flags & FTRACE_FL_TRAMP) !=
1805 !(rec->flags & FTRACE_FL_TRAMP_EN))
1806 flag |= FTRACE_FL_TRAMP;
1807 }
Steven Rostedt08f6fba2012-04-30 16:20:23 -04001808
Xiao Guangrong64fbcd12009-07-15 12:32:15 +08001809 /* If the state of this record hasn't changed, then do nothing */
1810 if ((rec->flags & FTRACE_FL_ENABLED) == flag)
Steven Rostedtc88fd862011-08-16 09:53:39 -04001811 return FTRACE_UPDATE_IGNORE;
Xiao Guangrong64fbcd12009-07-15 12:32:15 +08001812
1813 if (flag) {
Steven Rostedt08f6fba2012-04-30 16:20:23 -04001814 /* Save off if rec is being enabled (for return value) */
1815 flag ^= rec->flags & FTRACE_FL_ENABLED;
1816
1817 if (update) {
Steven Rostedtc88fd862011-08-16 09:53:39 -04001818 rec->flags |= FTRACE_FL_ENABLED;
Steven Rostedt08f6fba2012-04-30 16:20:23 -04001819 if (flag & FTRACE_FL_REGS) {
1820 if (rec->flags & FTRACE_FL_REGS)
1821 rec->flags |= FTRACE_FL_REGS_EN;
1822 else
1823 rec->flags &= ~FTRACE_FL_REGS_EN;
1824 }
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001825 if (flag & FTRACE_FL_TRAMP) {
1826 if (rec->flags & FTRACE_FL_TRAMP)
1827 rec->flags |= FTRACE_FL_TRAMP_EN;
1828 else
1829 rec->flags &= ~FTRACE_FL_TRAMP_EN;
1830 }
Steven Rostedt08f6fba2012-04-30 16:20:23 -04001831 }
1832
1833 /*
1834 * If this record is being updated from a nop, then
1835 * return UPDATE_MAKE_CALL.
Steven Rostedt08f6fba2012-04-30 16:20:23 -04001836 * Otherwise,
1837 * return UPDATE_MODIFY_CALL to tell the caller to convert
Steven Rostedt (Red Hat)f1b2f2b2014-05-07 16:09:49 -04001838 * from the save regs, to a non-save regs function or
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001839 * vice versa, or from a trampoline call.
Steven Rostedt08f6fba2012-04-30 16:20:23 -04001840 */
1841 if (flag & FTRACE_FL_ENABLED)
1842 return FTRACE_UPDATE_MAKE_CALL;
Steven Rostedt (Red Hat)f1b2f2b2014-05-07 16:09:49 -04001843
1844 return FTRACE_UPDATE_MODIFY_CALL;
Xiao Guangrong64fbcd12009-07-15 12:32:15 +08001845 }
1846
Steven Rostedt08f6fba2012-04-30 16:20:23 -04001847 if (update) {
1848 /* If there's no more users, clear all flags */
Steven Rostedt (Red Hat)0376bde2014-05-07 13:46:45 -04001849 if (!ftrace_rec_count(rec))
Steven Rostedt08f6fba2012-04-30 16:20:23 -04001850 rec->flags = 0;
1851 else
1852 /* Just disable the record (keep REGS state) */
1853 rec->flags &= ~FTRACE_FL_ENABLED;
1854 }
Steven Rostedtc88fd862011-08-16 09:53:39 -04001855
1856 return FTRACE_UPDATE_MAKE_NOP;
1857}
1858
1859/**
1860 * ftrace_update_record, set a record that now is tracing or not
1861 * @rec: the record to update
1862 * @enable: set to 1 if the record is tracing, zero to force disable
1863 *
1864 * The records that represent all functions that can be traced need
1865 * to be updated when tracing has been enabled.
1866 */
1867int ftrace_update_record(struct dyn_ftrace *rec, int enable)
1868{
1869 return ftrace_check_record(rec, enable, 1);
1870}
1871
1872/**
1873 * ftrace_test_record, check if the record has been enabled or not
1874 * @rec: the record to test
1875 * @enable: set to 1 to check if enabled, 0 if it is disabled
1876 *
1877 * The arch code may need to test if a record is already set to
1878 * tracing to determine how to modify the function code that it
1879 * represents.
1880 */
1881int ftrace_test_record(struct dyn_ftrace *rec, int enable)
1882{
1883 return ftrace_check_record(rec, enable, 0);
1884}
1885
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001886static struct ftrace_ops *
Steven Rostedt (Red Hat)5fecaa02014-07-24 16:00:31 -04001887ftrace_find_tramp_ops_any(struct dyn_ftrace *rec)
1888{
1889 struct ftrace_ops *op;
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04001890 unsigned long ip = rec->ip;
Steven Rostedt (Red Hat)5fecaa02014-07-24 16:00:31 -04001891
1892 do_for_each_ftrace_op(op, ftrace_ops_list) {
1893
1894 if (!op->trampoline)
1895 continue;
1896
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04001897 if (hash_contains_ip(ip, op->func_hash))
Steven Rostedt (Red Hat)5fecaa02014-07-24 16:00:31 -04001898 return op;
1899 } while_for_each_ftrace_op(op);
1900
1901 return NULL;
1902}
1903
1904static struct ftrace_ops *
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001905ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec)
1906{
1907 struct ftrace_ops *op;
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04001908 unsigned long ip = rec->ip;
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001909
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04001910 /*
1911 * Need to check removed ops first.
1912 * If they are being removed, and this rec has a tramp,
1913 * and this rec is in the ops list, then it would be the
1914 * one with the tramp.
1915 */
1916 if (removed_ops) {
1917 if (hash_contains_ip(ip, &removed_ops->old_hash))
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001918 return removed_ops;
1919 }
1920
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04001921 /*
1922 * Need to find the current trampoline for a rec.
1923 * Now, a trampoline is only attached to a rec if there
1924 * was a single 'ops' attached to it. But this can be called
1925 * when we are adding another op to the rec or removing the
1926 * current one. Thus, if the op is being added, we can
1927 * ignore it because it hasn't attached itself to the rec
1928 * yet. That means we just need to find the op that has a
1929 * trampoline and is not beeing added.
1930 */
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001931 do_for_each_ftrace_op(op, ftrace_ops_list) {
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04001932
1933 if (!op->trampoline)
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001934 continue;
1935
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04001936 /*
1937 * If the ops is being added, it hasn't gotten to
1938 * the point to be removed from this tree yet.
1939 */
1940 if (op->flags & FTRACE_OPS_FL_ADDING)
1941 continue;
1942
1943 /*
1944 * If the ops is not being added and has a trampoline,
1945 * then it must be the one that we want!
1946 */
1947 if (hash_contains_ip(ip, op->func_hash))
1948 return op;
1949
1950 /* If the ops is being modified, it may be in the old hash. */
1951 if ((op->flags & FTRACE_OPS_FL_MODIFYING) &&
1952 hash_contains_ip(ip, &op->old_hash))
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001953 return op;
1954
1955 } while_for_each_ftrace_op(op);
1956
1957 return NULL;
1958}
1959
1960static struct ftrace_ops *
1961ftrace_find_tramp_ops_new(struct dyn_ftrace *rec)
1962{
1963 struct ftrace_ops *op;
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04001964 unsigned long ip = rec->ip;
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001965
1966 do_for_each_ftrace_op(op, ftrace_ops_list) {
1967 /* pass rec in as regs to have non-NULL val */
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04001968 if (hash_contains_ip(ip, op->func_hash))
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001969 return op;
1970 } while_for_each_ftrace_op(op);
1971
1972 return NULL;
1973}
1974
Steven Rostedt (Red Hat)7413af12014-05-06 21:34:14 -04001975/**
1976 * ftrace_get_addr_new - Get the call address to set to
1977 * @rec: The ftrace record descriptor
1978 *
1979 * If the record has the FTRACE_FL_REGS set, that means that it
1980 * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
1981 * is not not set, then it wants to convert to the normal callback.
1982 *
1983 * Returns the address of the trampoline to set to
1984 */
1985unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec)
1986{
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001987 struct ftrace_ops *ops;
1988
1989 /* Trampolines take precedence over regs */
1990 if (rec->flags & FTRACE_FL_TRAMP) {
1991 ops = ftrace_find_tramp_ops_new(rec);
1992 if (FTRACE_WARN_ON(!ops || !ops->trampoline)) {
Steven Rostedt (Red Hat)bce0b6c2014-08-20 23:57:04 -04001993 pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
1994 (void *)rec->ip, (void *)rec->ip, rec->flags);
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04001995 /* Ftrace is shutting down, return anything */
1996 return (unsigned long)FTRACE_ADDR;
1997 }
1998 return ops->trampoline;
1999 }
2000
Steven Rostedt (Red Hat)7413af12014-05-06 21:34:14 -04002001 if (rec->flags & FTRACE_FL_REGS)
2002 return (unsigned long)FTRACE_REGS_ADDR;
2003 else
2004 return (unsigned long)FTRACE_ADDR;
2005}
2006
2007/**
2008 * ftrace_get_addr_curr - Get the call address that is already there
2009 * @rec: The ftrace record descriptor
2010 *
2011 * The FTRACE_FL_REGS_EN is set when the record already points to
2012 * a function that saves all the regs. Basically the '_EN' version
2013 * represents the current state of the function.
2014 *
2015 * Returns the address of the trampoline that is currently being called
2016 */
2017unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec)
2018{
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04002019 struct ftrace_ops *ops;
2020
2021 /* Trampolines take precedence over regs */
2022 if (rec->flags & FTRACE_FL_TRAMP_EN) {
2023 ops = ftrace_find_tramp_ops_curr(rec);
2024 if (FTRACE_WARN_ON(!ops)) {
2025 pr_warning("Bad trampoline accounting at: %p (%pS)\n",
2026 (void *)rec->ip, (void *)rec->ip);
2027 /* Ftrace is shutting down, return anything */
2028 return (unsigned long)FTRACE_ADDR;
2029 }
2030 return ops->trampoline;
2031 }
2032
Steven Rostedt (Red Hat)7413af12014-05-06 21:34:14 -04002033 if (rec->flags & FTRACE_FL_REGS_EN)
2034 return (unsigned long)FTRACE_REGS_ADDR;
2035 else
2036 return (unsigned long)FTRACE_ADDR;
2037}
2038
Steven Rostedtc88fd862011-08-16 09:53:39 -04002039static int
2040__ftrace_replace_code(struct dyn_ftrace *rec, int enable)
2041{
Steven Rostedt08f6fba2012-04-30 16:20:23 -04002042 unsigned long ftrace_old_addr;
Steven Rostedtc88fd862011-08-16 09:53:39 -04002043 unsigned long ftrace_addr;
2044 int ret;
2045
Steven Rostedt (Red Hat)7c0868e2014-05-08 07:01:21 -04002046 ftrace_addr = ftrace_get_addr_new(rec);
Steven Rostedtc88fd862011-08-16 09:53:39 -04002047
Steven Rostedt (Red Hat)7c0868e2014-05-08 07:01:21 -04002048 /* This needs to be done before we call ftrace_update_record */
2049 ftrace_old_addr = ftrace_get_addr_curr(rec);
2050
2051 ret = ftrace_update_record(rec, enable);
Steven Rostedt08f6fba2012-04-30 16:20:23 -04002052
Steven Rostedtc88fd862011-08-16 09:53:39 -04002053 switch (ret) {
2054 case FTRACE_UPDATE_IGNORE:
2055 return 0;
2056
2057 case FTRACE_UPDATE_MAKE_CALL:
2058 return ftrace_make_call(rec, ftrace_addr);
2059
2060 case FTRACE_UPDATE_MAKE_NOP:
Steven Rostedt (Red Hat)39b55522014-08-17 20:59:10 -04002061 return ftrace_make_nop(NULL, rec, ftrace_old_addr);
Steven Rostedt08f6fba2012-04-30 16:20:23 -04002062
Steven Rostedt08f6fba2012-04-30 16:20:23 -04002063 case FTRACE_UPDATE_MODIFY_CALL:
Steven Rostedt08f6fba2012-04-30 16:20:23 -04002064 return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr);
Steven Rostedtc88fd862011-08-16 09:53:39 -04002065 }
2066
2067 return -1; /* unknow ftrace bug */
Steven Rostedt5072c592008-05-12 21:20:43 +02002068}
2069
Steven Rostedte4f5d542012-04-27 09:13:18 -04002070void __weak ftrace_replace_code(int enable)
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002071{
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002072 struct dyn_ftrace *rec;
2073 struct ftrace_page *pg;
Steven Rostedt6a24a242009-02-17 11:20:26 -05002074 int failed;
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002075
Steven Rostedt45a4a232011-04-21 23:16:46 -04002076 if (unlikely(ftrace_disabled))
2077 return;
2078
Steven Rostedt265c8312009-02-13 12:43:56 -05002079 do_for_each_ftrace_rec(pg, rec) {
Steven Rostedte4f5d542012-04-27 09:13:18 -04002080 failed = __ftrace_replace_code(rec, enable);
Zhaoleifa9d13c2009-03-13 17:16:34 +08002081 if (failed) {
Steven Rostedt3279ba32009-10-07 16:57:56 -04002082 ftrace_bug(failed, rec->ip);
2083 /* Stop processing */
2084 return;
Steven Rostedt265c8312009-02-13 12:43:56 -05002085 }
2086 } while_for_each_ftrace_rec();
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002087}
2088
Steven Rostedtc88fd862011-08-16 09:53:39 -04002089struct ftrace_rec_iter {
2090 struct ftrace_page *pg;
2091 int index;
2092};
2093
2094/**
2095 * ftrace_rec_iter_start, start up iterating over traced functions
2096 *
2097 * Returns an iterator handle that is used to iterate over all
2098 * the records that represent address locations where functions
2099 * are traced.
2100 *
2101 * May return NULL if no records are available.
2102 */
2103struct ftrace_rec_iter *ftrace_rec_iter_start(void)
2104{
2105 /*
2106 * We only use a single iterator.
2107 * Protected by the ftrace_lock mutex.
2108 */
2109 static struct ftrace_rec_iter ftrace_rec_iter;
2110 struct ftrace_rec_iter *iter = &ftrace_rec_iter;
2111
2112 iter->pg = ftrace_pages_start;
2113 iter->index = 0;
2114
2115 /* Could have empty pages */
2116 while (iter->pg && !iter->pg->index)
2117 iter->pg = iter->pg->next;
2118
2119 if (!iter->pg)
2120 return NULL;
2121
2122 return iter;
2123}
2124
2125/**
2126 * ftrace_rec_iter_next, get the next record to process.
2127 * @iter: The handle to the iterator.
2128 *
2129 * Returns the next iterator after the given iterator @iter.
2130 */
2131struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter)
2132{
2133 iter->index++;
2134
2135 if (iter->index >= iter->pg->index) {
2136 iter->pg = iter->pg->next;
2137 iter->index = 0;
2138
2139 /* Could have empty pages */
2140 while (iter->pg && !iter->pg->index)
2141 iter->pg = iter->pg->next;
2142 }
2143
2144 if (!iter->pg)
2145 return NULL;
2146
2147 return iter;
2148}
2149
2150/**
2151 * ftrace_rec_iter_record, get the record at the iterator location
2152 * @iter: The current iterator location
2153 *
2154 * Returns the record that the current @iter is at.
2155 */
2156struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
2157{
2158 return &iter->pg->records[iter->index];
2159}
2160
Abhishek Sagar492a7ea52008-05-25 00:10:04 +05302161static int
Steven Rostedt31e88902008-11-14 16:21:19 -08002162ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002163{
2164 unsigned long ip;
Steven Rostedt593eb8a2008-10-23 09:32:59 -04002165 int ret;
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002166
2167 ip = rec->ip;
2168
Steven Rostedt45a4a232011-04-21 23:16:46 -04002169 if (unlikely(ftrace_disabled))
2170 return 0;
2171
Shaohua Li25aac9d2009-01-09 11:29:40 +08002172 ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
Steven Rostedt593eb8a2008-10-23 09:32:59 -04002173 if (ret) {
Steven Rostedt31e88902008-11-14 16:21:19 -08002174 ftrace_bug(ret, ip);
Abhishek Sagar492a7ea52008-05-25 00:10:04 +05302175 return 0;
Steven Rostedt37ad50842008-05-12 21:20:48 +02002176 }
Abhishek Sagar492a7ea52008-05-25 00:10:04 +05302177 return 1;
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002178}
2179
Steven Rostedt000ab692009-02-17 13:35:06 -05002180/*
2181 * archs can override this function if they must do something
2182 * before the modifying code is performed.
2183 */
2184int __weak ftrace_arch_code_modify_prepare(void)
2185{
2186 return 0;
2187}
2188
2189/*
2190 * archs can override this function if they must do something
2191 * after the modifying code is performed.
2192 */
2193int __weak ftrace_arch_code_modify_post_process(void)
2194{
2195 return 0;
2196}
2197
Steven Rostedt8ed3e2c2012-04-26 14:59:43 -04002198void ftrace_modify_all_code(int command)
2199{
Steven Rostedt (Red Hat)59338f72013-08-31 01:04:07 -04002200 int update = command & FTRACE_UPDATE_TRACE_FUNC;
Petr Mladekcd21067f2014-02-24 17:12:21 +01002201 int err = 0;
Steven Rostedt (Red Hat)59338f72013-08-31 01:04:07 -04002202
2203 /*
2204 * If the ftrace_caller calls a ftrace_ops func directly,
2205 * we need to make sure that it only traces functions it
2206 * expects to trace. When doing the switch of functions,
2207 * we need to update to the ftrace_ops_list_func first
2208 * before the transition between old and new calls are set,
2209 * as the ftrace_ops_list_func will check the ops hashes
2210 * to make sure the ops are having the right functions
2211 * traced.
2212 */
Petr Mladekcd21067f2014-02-24 17:12:21 +01002213 if (update) {
2214 err = ftrace_update_ftrace_func(ftrace_ops_list_func);
2215 if (FTRACE_WARN_ON(err))
2216 return;
2217 }
Steven Rostedt (Red Hat)59338f72013-08-31 01:04:07 -04002218
Steven Rostedt8ed3e2c2012-04-26 14:59:43 -04002219 if (command & FTRACE_UPDATE_CALLS)
2220 ftrace_replace_code(1);
2221 else if (command & FTRACE_DISABLE_CALLS)
2222 ftrace_replace_code(0);
2223
Steven Rostedt (Red Hat)405e1d82013-11-08 14:17:30 -05002224 if (update && ftrace_trace_function != ftrace_ops_list_func) {
2225 function_trace_op = set_function_trace_op;
2226 smp_wmb();
2227 /* If irqs are disabled, we are in stop machine */
2228 if (!irqs_disabled())
2229 smp_call_function(ftrace_sync_ipi, NULL, 1);
Petr Mladekcd21067f2014-02-24 17:12:21 +01002230 err = ftrace_update_ftrace_func(ftrace_trace_function);
2231 if (FTRACE_WARN_ON(err))
2232 return;
Steven Rostedt (Red Hat)405e1d82013-11-08 14:17:30 -05002233 }
Steven Rostedt8ed3e2c2012-04-26 14:59:43 -04002234
2235 if (command & FTRACE_START_FUNC_RET)
Petr Mladekcd21067f2014-02-24 17:12:21 +01002236 err = ftrace_enable_ftrace_graph_caller();
Steven Rostedt8ed3e2c2012-04-26 14:59:43 -04002237 else if (command & FTRACE_STOP_FUNC_RET)
Petr Mladekcd21067f2014-02-24 17:12:21 +01002238 err = ftrace_disable_ftrace_graph_caller();
2239 FTRACE_WARN_ON(err);
Steven Rostedt8ed3e2c2012-04-26 14:59:43 -04002240}
2241
Ingo Molnare309b412008-05-12 21:20:51 +02002242static int __ftrace_modify_code(void *data)
Steven Rostedt3d083392008-05-12 21:20:42 +02002243{
Steven Rostedtd61f82d2008-05-12 21:20:43 +02002244 int *command = data;
2245
Steven Rostedt8ed3e2c2012-04-26 14:59:43 -04002246 ftrace_modify_all_code(*command);
Steven Rostedt5a45cfe2008-11-26 00:16:24 -05002247
Steven Rostedtc88fd862011-08-16 09:53:39 -04002248 return 0;
2249}
2250
2251/**
2252 * ftrace_run_stop_machine, go back to the stop machine method
2253 * @command: The command to tell ftrace what to do
2254 *
2255 * If an arch needs to fall back to the stop machine method, the
2256 * it can call this function.
2257 */
2258void ftrace_run_stop_machine(int command)
2259{
2260 stop_machine(__ftrace_modify_code, &command, NULL);
2261}
2262
2263/**
2264 * arch_ftrace_update_code, modify the code to trace or not trace
2265 * @command: The command that needs to be done
2266 *
2267 * Archs can override this function if it does not need to
2268 * run stop_machine() to modify code.
2269 */
2270void __weak arch_ftrace_update_code(int command)
2271{
2272 ftrace_run_stop_machine(command);
2273}
2274
2275static void ftrace_run_update_code(int command)
2276{
2277 int ret;
2278
2279 ret = ftrace_arch_code_modify_prepare();
2280 FTRACE_WARN_ON(ret);
2281 if (ret)
2282 return;
Steven Rostedtc88fd862011-08-16 09:53:39 -04002283
2284 /*
2285 * By default we use stop_machine() to modify the code.
2286 * But archs can do what ever they want as long as it
2287 * is safe. The stop_machine() is the safest, but also
2288 * produces the most overhead.
2289 */
2290 arch_ftrace_update_code(command);
2291
Steven Rostedt000ab692009-02-17 13:35:06 -05002292 ret = ftrace_arch_code_modify_post_process();
2293 FTRACE_WARN_ON(ret);
Steven Rostedt3d083392008-05-12 21:20:42 +02002294}
2295
Steven Rostedt (Red Hat)e1effa02014-08-05 17:19:38 -04002296static void ftrace_run_modify_code(struct ftrace_ops *ops, int command)
2297{
2298 ops->flags |= FTRACE_OPS_FL_MODIFYING;
2299 ftrace_run_update_code(command);
2300 ops->flags &= ~FTRACE_OPS_FL_MODIFYING;
2301}
2302
Steven Rostedtd61f82d2008-05-12 21:20:43 +02002303static ftrace_func_t saved_ftrace_func;
Steven Rostedt60a7ecf2008-11-05 16:05:44 -05002304static int ftrace_start_up;
Steven Rostedtdf4fc312008-11-26 00:16:23 -05002305
Jiri Slabydb0fbad2014-03-10 21:42:11 +01002306static void control_ops_free(struct ftrace_ops *ops)
2307{
2308 free_percpu(ops->disabled);
2309}
2310
Steven Rostedtdf4fc312008-11-26 00:16:23 -05002311static void ftrace_startup_enable(int command)
2312{
2313 if (saved_ftrace_func != ftrace_trace_function) {
2314 saved_ftrace_func = ftrace_trace_function;
2315 command |= FTRACE_UPDATE_TRACE_FUNC;
2316 }
2317
2318 if (!command || !ftrace_enabled)
2319 return;
2320
2321 ftrace_run_update_code(command);
2322}
Steven Rostedtd61f82d2008-05-12 21:20:43 +02002323
Steven Rostedt (Red Hat)e1effa02014-08-05 17:19:38 -04002324static void ftrace_startup_all(int command)
2325{
2326 update_all_ops = true;
2327 ftrace_startup_enable(command);
2328 update_all_ops = false;
2329}
2330
Steven Rostedta1cd6172011-05-23 15:24:25 -04002331static int ftrace_startup(struct ftrace_ops *ops, int command)
Steven Rostedt3d083392008-05-12 21:20:42 +02002332{
Steven Rostedt (Red Hat)8a56d772013-11-25 20:59:46 -05002333 int ret;
Steven Rostedtb8489142011-05-04 09:27:52 -04002334
Steven Rostedt4eebcc82008-05-12 21:20:48 +02002335 if (unlikely(ftrace_disabled))
Steven Rostedta1cd6172011-05-23 15:24:25 -04002336 return -ENODEV;
Steven Rostedt4eebcc82008-05-12 21:20:48 +02002337
Steven Rostedt (Red Hat)8a56d772013-11-25 20:59:46 -05002338 ret = __register_ftrace_function(ops);
2339 if (ret)
2340 return ret;
2341
Steven Rostedt60a7ecf2008-11-05 16:05:44 -05002342 ftrace_start_up++;
Jiri Olsa30fb6aa2011-12-05 18:22:48 +01002343 command |= FTRACE_UPDATE_CALLS;
Steven Rostedt3d083392008-05-12 21:20:42 +02002344
Steven Rostedt (Red Hat)e1effa02014-08-05 17:19:38 -04002345 /*
2346 * Note that ftrace probes uses this to start up
2347 * and modify functions it will probe. But we still
2348 * set the ADDING flag for modification, as probes
2349 * do not have trampolines. If they add them in the
2350 * future, then the probes will need to distinguish
2351 * between adding and updating probes.
2352 */
2353 ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING;
Steven Rostedt (Red Hat)66209a52014-05-06 21:57:49 -04002354
2355 ftrace_hash_rec_enable(ops, 1);
Steven Rostedted926f92011-05-03 13:25:24 -04002356
Steven Rostedtdf4fc312008-11-26 00:16:23 -05002357 ftrace_startup_enable(command);
Steven Rostedta1cd6172011-05-23 15:24:25 -04002358
Steven Rostedt (Red Hat)e1effa02014-08-05 17:19:38 -04002359 ops->flags &= ~FTRACE_OPS_FL_ADDING;
2360
Steven Rostedta1cd6172011-05-23 15:24:25 -04002361 return 0;
Steven Rostedt3d083392008-05-12 21:20:42 +02002362}
2363
Steven Rostedt (Red Hat)8a56d772013-11-25 20:59:46 -05002364static int ftrace_shutdown(struct ftrace_ops *ops, int command)
Steven Rostedt3d083392008-05-12 21:20:42 +02002365{
Steven Rostedt (Red Hat)8a56d772013-11-25 20:59:46 -05002366 int ret;
Steven Rostedtb8489142011-05-04 09:27:52 -04002367
Steven Rostedt4eebcc82008-05-12 21:20:48 +02002368 if (unlikely(ftrace_disabled))
Steven Rostedt (Red Hat)8a56d772013-11-25 20:59:46 -05002369 return -ENODEV;
2370
2371 ret = __unregister_ftrace_function(ops);
2372 if (ret)
2373 return ret;
Steven Rostedt4eebcc82008-05-12 21:20:48 +02002374
Steven Rostedt60a7ecf2008-11-05 16:05:44 -05002375 ftrace_start_up--;
Frederic Weisbecker9ea1a152009-06-20 06:52:21 +02002376 /*
2377 * Just warn in case of unbalance, no need to kill ftrace, it's not
2378 * critical but the ftrace_call callers may be never nopped again after
2379 * further ftrace uses.
2380 */
2381 WARN_ON_ONCE(ftrace_start_up < 0);
2382
Steven Rostedt (Red Hat)66209a52014-05-06 21:57:49 -04002383 ftrace_hash_rec_disable(ops, 1);
Steven Rostedtb8489142011-05-04 09:27:52 -04002384
Namhyung Kima737e6d2014-06-12 23:56:12 +09002385 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
Steven Rostedtb8489142011-05-04 09:27:52 -04002386
Jiri Olsa30fb6aa2011-12-05 18:22:48 +01002387 command |= FTRACE_UPDATE_CALLS;
Steven Rostedtd61f82d2008-05-12 21:20:43 +02002388
2389 if (saved_ftrace_func != ftrace_trace_function) {
2390 saved_ftrace_func = ftrace_trace_function;
2391 command |= FTRACE_UPDATE_TRACE_FUNC;
2392 }
2393
Steven Rostedt (Red Hat)a4c35ed22014-01-13 12:56:21 -05002394 if (!command || !ftrace_enabled) {
2395 /*
2396 * If these are control ops, they still need their
2397 * per_cpu field freed. Since, function tracing is
2398 * not currently active, we can just free them
2399 * without synchronizing all CPUs.
2400 */
2401 if (ops->flags & FTRACE_OPS_FL_CONTROL)
2402 control_ops_free(ops);
Steven Rostedt (Red Hat)8a56d772013-11-25 20:59:46 -05002403 return 0;
Steven Rostedt (Red Hat)a4c35ed22014-01-13 12:56:21 -05002404 }
Steven Rostedt3d083392008-05-12 21:20:42 +02002405
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04002406 /*
2407 * If the ops uses a trampoline, then it needs to be
2408 * tested first on update.
2409 */
Steven Rostedt (Red Hat)e1effa02014-08-05 17:19:38 -04002410 ops->flags |= FTRACE_OPS_FL_REMOVING;
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04002411 removed_ops = ops;
2412
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04002413 /* The trampoline logic checks the old hashes */
2414 ops->old_hash.filter_hash = ops->func_hash->filter_hash;
2415 ops->old_hash.notrace_hash = ops->func_hash->notrace_hash;
2416
Steven Rostedtd61f82d2008-05-12 21:20:43 +02002417 ftrace_run_update_code(command);
Steven Rostedt (Red Hat)a4c35ed22014-01-13 12:56:21 -05002418
Steven Rostedt (Red Hat)84bde622014-09-12 14:21:13 -04002419 /*
2420 * If there's no more ops registered with ftrace, run a
2421 * sanity check to make sure all rec flags are cleared.
2422 */
2423 if (ftrace_ops_list == &ftrace_list_end) {
2424 struct ftrace_page *pg;
2425 struct dyn_ftrace *rec;
2426
2427 do_for_each_ftrace_rec(pg, rec) {
2428 if (FTRACE_WARN_ON_ONCE(rec->flags))
2429 pr_warn(" %pS flags:%lx\n",
2430 (void *)rec->ip, rec->flags);
2431 } while_for_each_ftrace_rec();
2432 }
2433
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04002434 ops->old_hash.filter_hash = NULL;
2435 ops->old_hash.notrace_hash = NULL;
2436
2437 removed_ops = NULL;
Steven Rostedt (Red Hat)e1effa02014-08-05 17:19:38 -04002438 ops->flags &= ~FTRACE_OPS_FL_REMOVING;
Steven Rostedt (Red Hat)79922b82014-05-06 21:56:17 -04002439
Steven Rostedt (Red Hat)a4c35ed22014-01-13 12:56:21 -05002440 /*
2441 * Dynamic ops may be freed, we must make sure that all
2442 * callers are done before leaving this function.
2443 * The same goes for freeing the per_cpu data of the control
2444 * ops.
2445 *
2446 * Again, normal synchronize_sched() is not good enough.
2447 * We need to do a hard force of sched synchronization.
2448 * This is because we use preempt_disable() to do RCU, but
2449 * the function tracers can be called where RCU is not watching
2450 * (like before user_exit()). We can not rely on the RCU
2451 * infrastructure to do the synchronization, thus we must do it
2452 * ourselves.
2453 */
2454 if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_CONTROL)) {
2455 schedule_on_each_cpu(ftrace_sync);
2456
2457 if (ops->flags & FTRACE_OPS_FL_CONTROL)
2458 control_ops_free(ops);
2459 }
2460
Steven Rostedt (Red Hat)8a56d772013-11-25 20:59:46 -05002461 return 0;
Steven Rostedt3d083392008-05-12 21:20:42 +02002462}
2463
Ingo Molnare309b412008-05-12 21:20:51 +02002464static void ftrace_startup_sysctl(void)
Steven Rostedtb0fc4942008-05-12 21:20:43 +02002465{
Steven Rostedt4eebcc82008-05-12 21:20:48 +02002466 if (unlikely(ftrace_disabled))
2467 return;
2468
Steven Rostedtd61f82d2008-05-12 21:20:43 +02002469 /* Force update next time */
2470 saved_ftrace_func = NULL;
Steven Rostedt60a7ecf2008-11-05 16:05:44 -05002471 /* ftrace_start_up is true if we want ftrace running */
2472 if (ftrace_start_up)
Jiri Olsa30fb6aa2011-12-05 18:22:48 +01002473 ftrace_run_update_code(FTRACE_UPDATE_CALLS);
Steven Rostedtb0fc4942008-05-12 21:20:43 +02002474}
2475
Ingo Molnare309b412008-05-12 21:20:51 +02002476static void ftrace_shutdown_sysctl(void)
Steven Rostedtb0fc4942008-05-12 21:20:43 +02002477{
Steven Rostedt4eebcc82008-05-12 21:20:48 +02002478 if (unlikely(ftrace_disabled))
2479 return;
2480
Steven Rostedt60a7ecf2008-11-05 16:05:44 -05002481 /* ftrace_start_up is true if ftrace is running */
2482 if (ftrace_start_up)
Steven Rostedt79e406d2010-09-14 22:19:46 -04002483 ftrace_run_update_code(FTRACE_DISABLE_CALLS);
Steven Rostedtb0fc4942008-05-12 21:20:43 +02002484}
2485
Steven Rostedt3d083392008-05-12 21:20:42 +02002486static cycle_t ftrace_update_time;
Steven Rostedt3d083392008-05-12 21:20:42 +02002487unsigned long ftrace_update_tot_cnt;
2488
Steven Rostedt (Red Hat)8c4f3c32013-07-30 00:04:32 -04002489static inline int ops_traces_mod(struct ftrace_ops *ops)
Steven Rostedtf7bc8b62011-07-14 23:02:27 -04002490{
Steven Rostedt (Red Hat)8c4f3c32013-07-30 00:04:32 -04002491 /*
2492 * Filter_hash being empty will default to trace module.
2493 * But notrace hash requires a test of individual module functions.
2494 */
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04002495 return ftrace_hash_empty(ops->func_hash->filter_hash) &&
2496 ftrace_hash_empty(ops->func_hash->notrace_hash);
Steven Rostedt (Red Hat)8c4f3c32013-07-30 00:04:32 -04002497}
Steven Rostedtf7bc8b62011-07-14 23:02:27 -04002498
Steven Rostedt (Red Hat)8c4f3c32013-07-30 00:04:32 -04002499/*
2500 * Check if the current ops references the record.
2501 *
2502 * If the ops traces all functions, then it was already accounted for.
2503 * If the ops does not trace the current record function, skip it.
2504 * If the ops ignores the function via notrace filter, skip it.
2505 */
2506static inline bool
2507ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec)
2508{
2509 /* If ops isn't enabled, ignore it */
2510 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
2511 return 0;
2512
2513 /* If ops traces all mods, we already accounted for it */
2514 if (ops_traces_mod(ops))
2515 return 0;
2516
2517 /* The function must be in the filter */
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04002518 if (!ftrace_hash_empty(ops->func_hash->filter_hash) &&
2519 !ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))
Steven Rostedt (Red Hat)8c4f3c32013-07-30 00:04:32 -04002520 return 0;
2521
2522 /* If in notrace hash, we ignore it too */
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04002523 if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip))
Steven Rostedt (Red Hat)8c4f3c32013-07-30 00:04:32 -04002524 return 0;
2525
2526 return 1;
2527}
2528
2529static int referenced_filters(struct dyn_ftrace *rec)
2530{
2531 struct ftrace_ops *ops;
2532 int cnt = 0;
2533
2534 for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
2535 if (ops_references_rec(ops, rec))
2536 cnt++;
2537 }
2538
2539 return cnt;
Steven Rostedtf7bc8b62011-07-14 23:02:27 -04002540}
2541
Jiri Slaby1dc43cf2014-02-24 19:59:56 +01002542static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
Steven Rostedt3d083392008-05-12 21:20:42 +02002543{
Steven Rostedt85ae32a2011-12-16 16:30:31 -05002544 struct ftrace_page *pg;
Lai Jiangshane94142a2009-03-13 17:51:27 +08002545 struct dyn_ftrace *p;
Abhishek Sagarf22f9a82008-06-21 23:50:29 +05302546 cycle_t start, stop;
Jiri Slaby1dc43cf2014-02-24 19:59:56 +01002547 unsigned long update_cnt = 0;
Steven Rostedtf7bc8b62011-07-14 23:02:27 -04002548 unsigned long ref = 0;
Steven Rostedt (Red Hat)8c4f3c32013-07-30 00:04:32 -04002549 bool test = false;
Steven Rostedt85ae32a2011-12-16 16:30:31 -05002550 int i;
Steven Rostedtf7bc8b62011-07-14 23:02:27 -04002551
2552 /*
2553 * When adding a module, we need to check if tracers are
2554 * currently enabled and if they are set to trace all functions.
2555 * If they are, we need to enable the module functions as well
2556 * as update the reference counts for those function records.
2557 */
2558 if (mod) {
2559 struct ftrace_ops *ops;
2560
2561 for (ops = ftrace_ops_list;
2562 ops != &ftrace_list_end; ops = ops->next) {
Steven Rostedt (Red Hat)8c4f3c32013-07-30 00:04:32 -04002563 if (ops->flags & FTRACE_OPS_FL_ENABLED) {
2564 if (ops_traces_mod(ops))
2565 ref++;
2566 else
2567 test = true;
2568 }
Steven Rostedtf7bc8b62011-07-14 23:02:27 -04002569 }
2570 }
Steven Rostedt3d083392008-05-12 21:20:42 +02002571
Ingo Molnar750ed1a2008-05-12 21:20:46 +02002572 start = ftrace_now(raw_smp_processor_id());
Steven Rostedt3d083392008-05-12 21:20:42 +02002573
Jiri Slaby1dc43cf2014-02-24 19:59:56 +01002574 for (pg = new_pgs; pg; pg = pg->next) {
Abhishek Sagarf22f9a82008-06-21 23:50:29 +05302575
Steven Rostedt85ae32a2011-12-16 16:30:31 -05002576 for (i = 0; i < pg->index; i++) {
Steven Rostedt (Red Hat)8c4f3c32013-07-30 00:04:32 -04002577 int cnt = ref;
2578
Steven Rostedt85ae32a2011-12-16 16:30:31 -05002579 /* If something went wrong, bail without enabling anything */
2580 if (unlikely(ftrace_disabled))
2581 return -1;
Steven Rostedt3d083392008-05-12 21:20:42 +02002582
Steven Rostedt85ae32a2011-12-16 16:30:31 -05002583 p = &pg->records[i];
Steven Rostedt (Red Hat)8c4f3c32013-07-30 00:04:32 -04002584 if (test)
2585 cnt += referenced_filters(p);
2586 p->flags = cnt;
Abhishek Sagar0eb96702008-06-01 21:47:30 +05302587
Steven Rostedt85ae32a2011-12-16 16:30:31 -05002588 /*
2589 * Do the initial record conversion from mcount jump
2590 * to the NOP instructions.
2591 */
2592 if (!ftrace_code_disable(mod, p))
2593 break;
Jiri Olsa5cb084b2009-10-13 16:33:53 -04002594
Jiri Slaby1dc43cf2014-02-24 19:59:56 +01002595 update_cnt++;
Jiri Olsa5cb084b2009-10-13 16:33:53 -04002596
Steven Rostedt85ae32a2011-12-16 16:30:31 -05002597 /*
2598 * If the tracing is enabled, go ahead and enable the record.
2599 *
2600 * The reason not to enable the record immediatelly is the
2601 * inherent check of ftrace_make_nop/ftrace_make_call for
2602 * correct previous instructions. Making first the NOP
2603 * conversion puts the module to the correct state, thus
2604 * passing the ftrace_make_call check.
2605 */
Steven Rostedt (Red Hat)8c4f3c32013-07-30 00:04:32 -04002606 if (ftrace_start_up && cnt) {
Steven Rostedt85ae32a2011-12-16 16:30:31 -05002607 int failed = __ftrace_replace_code(p, 1);
2608 if (failed)
2609 ftrace_bug(failed, p->ip);
2610 }
Jiri Olsa5cb084b2009-10-13 16:33:53 -04002611 }
Steven Rostedt3d083392008-05-12 21:20:42 +02002612 }
2613
Ingo Molnar750ed1a2008-05-12 21:20:46 +02002614 stop = ftrace_now(raw_smp_processor_id());
Steven Rostedt3d083392008-05-12 21:20:42 +02002615 ftrace_update_time = stop - start;
Jiri Slaby1dc43cf2014-02-24 19:59:56 +01002616 ftrace_update_tot_cnt += update_cnt;
Steven Rostedt3d083392008-05-12 21:20:42 +02002617
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +02002618 return 0;
2619}
2620
Steven Rostedta7900872011-12-16 16:23:44 -05002621static int ftrace_allocate_records(struct ftrace_page *pg, int count)
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002622{
Steven Rostedta7900872011-12-16 16:23:44 -05002623 int order;
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002624 int cnt;
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002625
Steven Rostedta7900872011-12-16 16:23:44 -05002626 if (WARN_ON(!count))
2627 return -EINVAL;
2628
2629 order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE));
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002630
2631 /*
Steven Rostedta7900872011-12-16 16:23:44 -05002632 * We want to fill as much as possible. No more than a page
2633 * may be empty.
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002634 */
Steven Rostedta7900872011-12-16 16:23:44 -05002635 while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE)
2636 order--;
Steven Rostedt3c1720f2008-05-12 21:20:43 +02002637
Steven Rostedta7900872011-12-16 16:23:44 -05002638 again:
2639 pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
2640
2641 if (!pg->records) {
2642 /* if we can't allocate this size, try something smaller */
2643 if (!order)
2644 return -ENOMEM;
2645 order >>= 1;
2646 goto again;
2647 }
2648
2649 cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
2650 pg->size = cnt;
2651
2652 if (cnt > count)
2653 cnt = count;
2654
2655 return cnt;
2656}
2657
2658static struct ftrace_page *
2659ftrace_allocate_pages(unsigned long num_to_init)
2660{
2661 struct ftrace_page *start_pg;
2662 struct ftrace_page *pg;
2663 int order;
2664 int cnt;
2665
2666 if (!num_to_init)
2667 return 0;
2668
2669 start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL);
2670 if (!pg)
2671 return NULL;
2672
2673 /*
2674 * Try to allocate as much as possible in one continues
2675 * location that fills in all of the space. We want to
2676 * waste as little space as possible.
2677 */
2678 for (;;) {
2679 cnt = ftrace_allocate_records(pg, num_to_init);
2680 if (cnt < 0)
2681 goto free_pages;
2682
2683 num_to_init -= cnt;
2684 if (!num_to_init)
2685 break;
2686
2687 pg->next = kzalloc(sizeof(*pg), GFP_KERNEL);
2688 if (!pg->next)
2689 goto free_pages;
2690
2691 pg = pg->next;
2692 }
2693
2694 return start_pg;
2695
2696 free_pages:
Namhyung Kim1f61be002014-06-11 17:06:53 +09002697 pg = start_pg;
2698 while (pg) {
Steven Rostedta7900872011-12-16 16:23:44 -05002699 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
2700 free_pages((unsigned long)pg->records, order);
2701 start_pg = pg->next;
2702 kfree(pg);
2703 pg = start_pg;
2704 }
2705 pr_info("ftrace: FAILED to allocate memory for functions\n");
2706 return NULL;
2707}
2708
Steven Rostedt5072c592008-05-12 21:20:43 +02002709#define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
2710
2711struct ftrace_iterator {
Steven Rostedt98c4fd02010-09-10 11:47:43 -04002712 loff_t pos;
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002713 loff_t func_pos;
2714 struct ftrace_page *pg;
2715 struct dyn_ftrace *func;
2716 struct ftrace_func_probe *probe;
2717 struct trace_parser parser;
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04002718 struct ftrace_hash *hash;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04002719 struct ftrace_ops *ops;
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002720 int hidx;
2721 int idx;
2722 unsigned flags;
Steven Rostedt5072c592008-05-12 21:20:43 +02002723};
2724
Ingo Molnare309b412008-05-12 21:20:51 +02002725static void *
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002726t_hash_next(struct seq_file *m, loff_t *pos)
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002727{
2728 struct ftrace_iterator *iter = m->private;
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002729 struct hlist_node *hnd = NULL;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002730 struct hlist_head *hhd;
2731
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002732 (*pos)++;
Steven Rostedt98c4fd02010-09-10 11:47:43 -04002733 iter->pos = *pos;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002734
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002735 if (iter->probe)
2736 hnd = &iter->probe->node;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002737 retry:
2738 if (iter->hidx >= FTRACE_FUNC_HASHSIZE)
2739 return NULL;
2740
2741 hhd = &ftrace_func_hash[iter->hidx];
2742
2743 if (hlist_empty(hhd)) {
2744 iter->hidx++;
2745 hnd = NULL;
2746 goto retry;
2747 }
2748
2749 if (!hnd)
2750 hnd = hhd->first;
2751 else {
2752 hnd = hnd->next;
2753 if (!hnd) {
2754 iter->hidx++;
2755 goto retry;
2756 }
2757 }
2758
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002759 if (WARN_ON_ONCE(!hnd))
2760 return NULL;
2761
2762 iter->probe = hlist_entry(hnd, struct ftrace_func_probe, node);
2763
2764 return iter;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002765}
2766
2767static void *t_hash_start(struct seq_file *m, loff_t *pos)
2768{
2769 struct ftrace_iterator *iter = m->private;
2770 void *p = NULL;
Li Zefand82d6242009-06-24 09:54:54 +08002771 loff_t l;
2772
Steven Rostedt69a30832011-12-19 15:21:16 -05002773 if (!(iter->flags & FTRACE_ITER_DO_HASH))
2774 return NULL;
2775
Steven Rostedt2bccfff2010-09-09 08:43:22 -04002776 if (iter->func_pos > *pos)
2777 return NULL;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002778
Li Zefand82d6242009-06-24 09:54:54 +08002779 iter->hidx = 0;
Steven Rostedt2bccfff2010-09-09 08:43:22 -04002780 for (l = 0; l <= (*pos - iter->func_pos); ) {
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002781 p = t_hash_next(m, &l);
Li Zefand82d6242009-06-24 09:54:54 +08002782 if (!p)
2783 break;
2784 }
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002785 if (!p)
2786 return NULL;
2787
Steven Rostedt98c4fd02010-09-10 11:47:43 -04002788 /* Only set this if we have an item */
2789 iter->flags |= FTRACE_ITER_HASH;
2790
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002791 return iter;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002792}
2793
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002794static int
2795t_hash_show(struct seq_file *m, struct ftrace_iterator *iter)
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002796{
Steven Rostedtb6887d72009-02-17 12:32:04 -05002797 struct ftrace_func_probe *rec;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002798
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002799 rec = iter->probe;
2800 if (WARN_ON_ONCE(!rec))
2801 return -EIO;
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002802
Steven Rostedt809dcf22009-02-16 23:06:01 -05002803 if (rec->ops->print)
2804 return rec->ops->print(m, rec->ip, rec->ops, rec->data);
2805
Steven Rostedtb375a112009-09-17 00:05:58 -04002806 seq_printf(m, "%ps:%ps", (void *)rec->ip, (void *)rec->ops->func);
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002807
2808 if (rec->data)
2809 seq_printf(m, ":%p", rec->data);
2810 seq_putc(m, '\n');
2811
2812 return 0;
2813}
2814
2815static void *
Steven Rostedt5072c592008-05-12 21:20:43 +02002816t_next(struct seq_file *m, void *v, loff_t *pos)
2817{
2818 struct ftrace_iterator *iter = m->private;
Steven Rostedtfc13cb02011-12-19 14:41:25 -05002819 struct ftrace_ops *ops = iter->ops;
Steven Rostedt5072c592008-05-12 21:20:43 +02002820 struct dyn_ftrace *rec = NULL;
2821
Steven Rostedt45a4a232011-04-21 23:16:46 -04002822 if (unlikely(ftrace_disabled))
2823 return NULL;
2824
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002825 if (iter->flags & FTRACE_ITER_HASH)
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002826 return t_hash_next(m, pos);
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002827
Steven Rostedt5072c592008-05-12 21:20:43 +02002828 (*pos)++;
Jiri Olsa1106b692011-02-16 17:35:34 +01002829 iter->pos = iter->func_pos = *pos;
Steven Rostedt5072c592008-05-12 21:20:43 +02002830
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05002831 if (iter->flags & FTRACE_ITER_PRINTALL)
Steven Rostedt57c072c2010-09-14 11:21:11 -04002832 return t_hash_start(m, pos);
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05002833
Steven Rostedt5072c592008-05-12 21:20:43 +02002834 retry:
2835 if (iter->idx >= iter->pg->index) {
2836 if (iter->pg->next) {
2837 iter->pg = iter->pg->next;
2838 iter->idx = 0;
2839 goto retry;
2840 }
2841 } else {
2842 rec = &iter->pg->records[iter->idx++];
Steven Rostedt320823092011-12-16 14:42:37 -05002843 if (((iter->flags & FTRACE_ITER_FILTER) &&
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04002844 !(ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))) ||
Steven Rostedt0183fb1c2008-11-07 22:36:02 -05002845
Steven Rostedt41c52c02008-05-22 11:46:33 -04002846 ((iter->flags & FTRACE_ITER_NOTRACE) &&
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04002847 !ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip)) ||
Steven Rostedt647bcd02011-05-03 14:39:21 -04002848
2849 ((iter->flags & FTRACE_ITER_ENABLED) &&
Steven Rostedt (Red Hat)23ea9c42013-05-09 19:31:48 -04002850 !(rec->flags & FTRACE_FL_ENABLED))) {
Steven Rostedt647bcd02011-05-03 14:39:21 -04002851
Steven Rostedt5072c592008-05-12 21:20:43 +02002852 rec = NULL;
2853 goto retry;
2854 }
2855 }
2856
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002857 if (!rec)
Steven Rostedt57c072c2010-09-14 11:21:11 -04002858 return t_hash_start(m, pos);
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002859
2860 iter->func = rec;
2861
2862 return iter;
Steven Rostedt5072c592008-05-12 21:20:43 +02002863}
2864
Steven Rostedt98c4fd02010-09-10 11:47:43 -04002865static void reset_iter_read(struct ftrace_iterator *iter)
2866{
2867 iter->pos = 0;
2868 iter->func_pos = 0;
Dan Carpenter70f77b3f2012-06-09 19:10:27 +03002869 iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_HASH);
Steven Rostedt5072c592008-05-12 21:20:43 +02002870}
2871
2872static void *t_start(struct seq_file *m, loff_t *pos)
2873{
2874 struct ftrace_iterator *iter = m->private;
Steven Rostedtfc13cb02011-12-19 14:41:25 -05002875 struct ftrace_ops *ops = iter->ops;
Steven Rostedt5072c592008-05-12 21:20:43 +02002876 void *p = NULL;
Li Zefan694ce0a2009-06-24 09:54:19 +08002877 loff_t l;
Steven Rostedt5072c592008-05-12 21:20:43 +02002878
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002879 mutex_lock(&ftrace_lock);
Steven Rostedt45a4a232011-04-21 23:16:46 -04002880
2881 if (unlikely(ftrace_disabled))
2882 return NULL;
2883
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05002884 /*
Steven Rostedt98c4fd02010-09-10 11:47:43 -04002885 * If an lseek was done, then reset and start from beginning.
2886 */
2887 if (*pos < iter->pos)
2888 reset_iter_read(iter);
2889
2890 /*
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05002891 * For set_ftrace_filter reading, if we have the filter
2892 * off, we can short cut and just print out that all
2893 * functions are enabled.
2894 */
Namhyung Kim8c006cf2014-06-13 16:24:06 +09002895 if ((iter->flags & FTRACE_ITER_FILTER &&
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04002896 ftrace_hash_empty(ops->func_hash->filter_hash)) ||
Namhyung Kim8c006cf2014-06-13 16:24:06 +09002897 (iter->flags & FTRACE_ITER_NOTRACE &&
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04002898 ftrace_hash_empty(ops->func_hash->notrace_hash))) {
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05002899 if (*pos > 0)
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002900 return t_hash_start(m, pos);
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05002901 iter->flags |= FTRACE_ITER_PRINTALL;
Chris Wrightdf091622010-09-09 16:34:59 -07002902 /* reset in case of seek/pread */
2903 iter->flags &= ~FTRACE_ITER_HASH;
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05002904 return iter;
2905 }
2906
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002907 if (iter->flags & FTRACE_ITER_HASH)
2908 return t_hash_start(m, pos);
2909
Steven Rostedt98c4fd02010-09-10 11:47:43 -04002910 /*
2911 * Unfortunately, we need to restart at ftrace_pages_start
2912 * every time we let go of the ftrace_mutex. This is because
2913 * those pointers can change without the lock.
2914 */
Li Zefan694ce0a2009-06-24 09:54:19 +08002915 iter->pg = ftrace_pages_start;
2916 iter->idx = 0;
2917 for (l = 0; l <= *pos; ) {
2918 p = t_next(m, p, &l);
2919 if (!p)
2920 break;
Liming Wang50cdaf02008-11-28 12:13:21 +08002921 }
walimis5821e1b2008-11-15 15:19:06 +08002922
Steven Rostedt69a30832011-12-19 15:21:16 -05002923 if (!p)
2924 return t_hash_start(m, pos);
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002925
2926 return iter;
Steven Rostedt5072c592008-05-12 21:20:43 +02002927}
2928
2929static void t_stop(struct seq_file *m, void *p)
2930{
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002931 mutex_unlock(&ftrace_lock);
Steven Rostedt5072c592008-05-12 21:20:43 +02002932}
2933
2934static int t_show(struct seq_file *m, void *v)
2935{
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05002936 struct ftrace_iterator *iter = m->private;
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002937 struct dyn_ftrace *rec;
Steven Rostedt5072c592008-05-12 21:20:43 +02002938
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002939 if (iter->flags & FTRACE_ITER_HASH)
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002940 return t_hash_show(m, iter);
Steven Rostedt8fc0c702009-02-16 15:28:00 -05002941
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05002942 if (iter->flags & FTRACE_ITER_PRINTALL) {
Namhyung Kim8c006cf2014-06-13 16:24:06 +09002943 if (iter->flags & FTRACE_ITER_NOTRACE)
2944 seq_printf(m, "#### no functions disabled ####\n");
2945 else
2946 seq_printf(m, "#### all functions enabled ####\n");
Steven Rostedt0c75a3e2009-02-16 11:21:52 -05002947 return 0;
2948 }
2949
Steven Rostedt4aeb6962010-09-09 10:00:28 -04002950 rec = iter->func;
2951
Steven Rostedt5072c592008-05-12 21:20:43 +02002952 if (!rec)
2953 return 0;
2954
Steven Rostedt647bcd02011-05-03 14:39:21 -04002955 seq_printf(m, "%ps", (void *)rec->ip);
Steven Rostedt (Red Hat)9674b2f2014-05-09 16:54:59 -04002956 if (iter->flags & FTRACE_ITER_ENABLED) {
Steven Rostedt08f6fba2012-04-30 16:20:23 -04002957 seq_printf(m, " (%ld)%s",
Steven Rostedt (Red Hat)0376bde2014-05-07 13:46:45 -04002958 ftrace_rec_count(rec),
Steven Rostedt (Red Hat)9674b2f2014-05-09 16:54:59 -04002959 rec->flags & FTRACE_FL_REGS ? " R" : " ");
2960 if (rec->flags & FTRACE_FL_TRAMP_EN) {
2961 struct ftrace_ops *ops;
2962
Steven Rostedt (Red Hat)5fecaa02014-07-24 16:00:31 -04002963 ops = ftrace_find_tramp_ops_any(rec);
Steven Rostedt (Red Hat)fef5aee2014-07-24 12:25:47 -04002964 if (ops)
Steven Rostedt (Red Hat)9674b2f2014-05-09 16:54:59 -04002965 seq_printf(m, "\ttramp: %pS",
2966 (void *)ops->trampoline);
2967 else
2968 seq_printf(m, "\ttramp: ERROR!");
2969 }
2970 }
2971
Steven Rostedt647bcd02011-05-03 14:39:21 -04002972 seq_printf(m, "\n");
Steven Rostedt5072c592008-05-12 21:20:43 +02002973
2974 return 0;
2975}
2976
James Morris88e9d342009-09-22 16:43:43 -07002977static const struct seq_operations show_ftrace_seq_ops = {
Steven Rostedt5072c592008-05-12 21:20:43 +02002978 .start = t_start,
2979 .next = t_next,
2980 .stop = t_stop,
2981 .show = t_show,
2982};
2983
Ingo Molnare309b412008-05-12 21:20:51 +02002984static int
Steven Rostedt5072c592008-05-12 21:20:43 +02002985ftrace_avail_open(struct inode *inode, struct file *file)
2986{
2987 struct ftrace_iterator *iter;
Steven Rostedt5072c592008-05-12 21:20:43 +02002988
Steven Rostedt4eebcc82008-05-12 21:20:48 +02002989 if (unlikely(ftrace_disabled))
2990 return -ENODEV;
2991
Jiri Olsa50e18b92012-04-25 10:23:39 +02002992 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
2993 if (iter) {
2994 iter->pg = ftrace_pages_start;
2995 iter->ops = &global_ops;
Ingo Molnar4bf39a92008-05-12 21:20:46 +02002996 }
Steven Rostedt5072c592008-05-12 21:20:43 +02002997
Jiri Olsa50e18b92012-04-25 10:23:39 +02002998 return iter ? 0 : -ENOMEM;
Steven Rostedt5072c592008-05-12 21:20:43 +02002999}
3000
Steven Rostedt647bcd02011-05-03 14:39:21 -04003001static int
3002ftrace_enabled_open(struct inode *inode, struct file *file)
3003{
3004 struct ftrace_iterator *iter;
Steven Rostedt647bcd02011-05-03 14:39:21 -04003005
3006 if (unlikely(ftrace_disabled))
3007 return -ENODEV;
3008
Jiri Olsa50e18b92012-04-25 10:23:39 +02003009 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3010 if (iter) {
3011 iter->pg = ftrace_pages_start;
3012 iter->flags = FTRACE_ITER_ENABLED;
3013 iter->ops = &global_ops;
Steven Rostedt647bcd02011-05-03 14:39:21 -04003014 }
3015
Jiri Olsa50e18b92012-04-25 10:23:39 +02003016 return iter ? 0 : -ENOMEM;
Steven Rostedt647bcd02011-05-03 14:39:21 -04003017}
3018
Steven Rostedtfc13cb02011-12-19 14:41:25 -05003019/**
3020 * ftrace_regex_open - initialize function tracer filter files
3021 * @ops: The ftrace_ops that hold the hash filters
3022 * @flag: The type of filter to process
3023 * @inode: The inode, usually passed in to your open routine
3024 * @file: The file, usually passed in to your open routine
3025 *
3026 * ftrace_regex_open() initializes the filter files for the
3027 * @ops. Depending on @flag it may process the filter hash or
3028 * the notrace hash of @ops. With this called from the open
3029 * routine, you can use ftrace_filter_write() for the write
3030 * routine if @flag has FTRACE_ITER_FILTER set, or
3031 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
Steven Rostedt (Red Hat)098c879e2013-12-21 17:39:40 -05003032 * tracing_lseek() should be used as the lseek routine, and
Steven Rostedtfc13cb02011-12-19 14:41:25 -05003033 * release must call ftrace_regex_release().
3034 */
3035int
Steven Rostedtf45948e2011-05-02 12:29:25 -04003036ftrace_regex_open(struct ftrace_ops *ops, int flag,
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003037 struct inode *inode, struct file *file)
Steven Rostedt5072c592008-05-12 21:20:43 +02003038{
3039 struct ftrace_iterator *iter;
Steven Rostedtf45948e2011-05-02 12:29:25 -04003040 struct ftrace_hash *hash;
Steven Rostedt5072c592008-05-12 21:20:43 +02003041 int ret = 0;
3042
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +09003043 ftrace_ops_init(ops);
3044
Steven Rostedt4eebcc82008-05-12 21:20:48 +02003045 if (unlikely(ftrace_disabled))
3046 return -ENODEV;
3047
Steven Rostedt5072c592008-05-12 21:20:43 +02003048 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
3049 if (!iter)
3050 return -ENOMEM;
3051
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02003052 if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) {
3053 kfree(iter);
3054 return -ENOMEM;
3055 }
3056
Masami Hiramatsu3f2367b2013-05-09 14:44:21 +09003057 iter->ops = ops;
3058 iter->flags = flag;
3059
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003060 mutex_lock(&ops->func_hash->regex_lock);
Masami Hiramatsu3f2367b2013-05-09 14:44:21 +09003061
Steven Rostedtf45948e2011-05-02 12:29:25 -04003062 if (flag & FTRACE_ITER_NOTRACE)
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003063 hash = ops->func_hash->notrace_hash;
Steven Rostedtf45948e2011-05-02 12:29:25 -04003064 else
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003065 hash = ops->func_hash->filter_hash;
Steven Rostedtf45948e2011-05-02 12:29:25 -04003066
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003067 if (file->f_mode & FMODE_WRITE) {
Namhyung Kimef2fbe12014-06-11 17:06:54 +09003068 const int size_bits = FTRACE_HASH_DEFAULT_BITS;
3069
3070 if (file->f_flags & O_TRUNC)
3071 iter->hash = alloc_ftrace_hash(size_bits);
3072 else
3073 iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash);
3074
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003075 if (!iter->hash) {
3076 trace_parser_put(&iter->parser);
3077 kfree(iter);
Masami Hiramatsu3f2367b2013-05-09 14:44:21 +09003078 ret = -ENOMEM;
3079 goto out_unlock;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003080 }
3081 }
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003082
Steven Rostedt5072c592008-05-12 21:20:43 +02003083 if (file->f_mode & FMODE_READ) {
3084 iter->pg = ftrace_pages_start;
Steven Rostedt5072c592008-05-12 21:20:43 +02003085
3086 ret = seq_open(file, &show_ftrace_seq_ops);
3087 if (!ret) {
3088 struct seq_file *m = file->private_data;
3089 m->private = iter;
Li Zefan79fe2492009-09-22 13:54:28 +08003090 } else {
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003091 /* Failed */
3092 free_ftrace_hash(iter->hash);
Li Zefan79fe2492009-09-22 13:54:28 +08003093 trace_parser_put(&iter->parser);
Steven Rostedt5072c592008-05-12 21:20:43 +02003094 kfree(iter);
Li Zefan79fe2492009-09-22 13:54:28 +08003095 }
Steven Rostedt5072c592008-05-12 21:20:43 +02003096 } else
3097 file->private_data = iter;
Masami Hiramatsu3f2367b2013-05-09 14:44:21 +09003098
3099 out_unlock:
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003100 mutex_unlock(&ops->func_hash->regex_lock);
Steven Rostedt5072c592008-05-12 21:20:43 +02003101
3102 return ret;
3103}
3104
Steven Rostedt41c52c02008-05-22 11:46:33 -04003105static int
3106ftrace_filter_open(struct inode *inode, struct file *file)
3107{
Steven Rostedt (Red Hat)e3b3e2e2013-11-11 23:07:14 -05003108 struct ftrace_ops *ops = inode->i_private;
3109
3110 return ftrace_regex_open(ops,
Steven Rostedt69a30832011-12-19 15:21:16 -05003111 FTRACE_ITER_FILTER | FTRACE_ITER_DO_HASH,
3112 inode, file);
Steven Rostedt41c52c02008-05-22 11:46:33 -04003113}
3114
3115static int
3116ftrace_notrace_open(struct inode *inode, struct file *file)
3117{
Steven Rostedt (Red Hat)e3b3e2e2013-11-11 23:07:14 -05003118 struct ftrace_ops *ops = inode->i_private;
3119
3120 return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE,
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003121 inode, file);
Steven Rostedt41c52c02008-05-22 11:46:33 -04003122}
3123
Steven Rostedt64e7c442009-02-13 17:08:48 -05003124static int ftrace_match(char *str, char *regex, int len, int type)
Steven Rostedt9f4801e2009-02-13 15:56:43 -05003125{
Steven Rostedt9f4801e2009-02-13 15:56:43 -05003126 int matched = 0;
Li Zefan751e9982010-01-14 10:53:02 +08003127 int slen;
Steven Rostedt9f4801e2009-02-13 15:56:43 -05003128
Steven Rostedt9f4801e2009-02-13 15:56:43 -05003129 switch (type) {
3130 case MATCH_FULL:
3131 if (strcmp(str, regex) == 0)
3132 matched = 1;
3133 break;
3134 case MATCH_FRONT_ONLY:
3135 if (strncmp(str, regex, len) == 0)
3136 matched = 1;
3137 break;
3138 case MATCH_MIDDLE_ONLY:
3139 if (strstr(str, regex))
3140 matched = 1;
3141 break;
3142 case MATCH_END_ONLY:
Li Zefan751e9982010-01-14 10:53:02 +08003143 slen = strlen(str);
3144 if (slen >= len && memcmp(str + slen - len, regex, len) == 0)
Steven Rostedt9f4801e2009-02-13 15:56:43 -05003145 matched = 1;
3146 break;
3147 }
3148
3149 return matched;
3150}
3151
Steven Rostedtb448c4e2011-04-29 15:12:32 -04003152static int
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003153enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not)
Steven Rostedt996e87b2011-04-26 16:11:03 -04003154{
Steven Rostedtb448c4e2011-04-29 15:12:32 -04003155 struct ftrace_func_entry *entry;
Steven Rostedtb448c4e2011-04-29 15:12:32 -04003156 int ret = 0;
3157
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003158 entry = ftrace_lookup_ip(hash, rec->ip);
3159 if (not) {
3160 /* Do nothing if it doesn't exist */
3161 if (!entry)
3162 return 0;
3163
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003164 free_hash_entry(hash, entry);
Steven Rostedtb448c4e2011-04-29 15:12:32 -04003165 } else {
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003166 /* Do nothing if it exists */
3167 if (entry)
3168 return 0;
Steven Rostedtb448c4e2011-04-29 15:12:32 -04003169
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003170 ret = add_hash_entry(hash, rec->ip);
Steven Rostedtb448c4e2011-04-29 15:12:32 -04003171 }
3172 return ret;
Steven Rostedt996e87b2011-04-26 16:11:03 -04003173}
3174
Steven Rostedt64e7c442009-02-13 17:08:48 -05003175static int
Steven Rostedtb9df92d2011-04-28 20:32:08 -04003176ftrace_match_record(struct dyn_ftrace *rec, char *mod,
3177 char *regex, int len, int type)
Steven Rostedt64e7c442009-02-13 17:08:48 -05003178{
3179 char str[KSYM_SYMBOL_LEN];
Steven Rostedtb9df92d2011-04-28 20:32:08 -04003180 char *modname;
Steven Rostedt64e7c442009-02-13 17:08:48 -05003181
Steven Rostedtb9df92d2011-04-28 20:32:08 -04003182 kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
3183
3184 if (mod) {
3185 /* module lookup requires matching the module */
3186 if (!modname || strcmp(modname, mod))
3187 return 0;
3188
3189 /* blank search means to match all funcs in the mod */
3190 if (!len)
3191 return 1;
3192 }
3193
Steven Rostedt64e7c442009-02-13 17:08:48 -05003194 return ftrace_match(str, regex, len, type);
3195}
3196
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003197static int
3198match_records(struct ftrace_hash *hash, char *buff,
3199 int len, char *mod, int not)
Steven Rostedt9f4801e2009-02-13 15:56:43 -05003200{
Steven Rostedtb9df92d2011-04-28 20:32:08 -04003201 unsigned search_len = 0;
Steven Rostedt9f4801e2009-02-13 15:56:43 -05003202 struct ftrace_page *pg;
3203 struct dyn_ftrace *rec;
Steven Rostedtb9df92d2011-04-28 20:32:08 -04003204 int type = MATCH_FULL;
3205 char *search = buff;
Li Zefan311d16d2009-12-08 11:15:11 +08003206 int found = 0;
Steven Rostedtb448c4e2011-04-29 15:12:32 -04003207 int ret;
Steven Rostedt9f4801e2009-02-13 15:56:43 -05003208
Steven Rostedtb9df92d2011-04-28 20:32:08 -04003209 if (len) {
3210 type = filter_parse_regex(buff, len, &search, &not);
3211 search_len = strlen(search);
3212 }
Steven Rostedt9f4801e2009-02-13 15:56:43 -05003213
Steven Rostedt52baf112009-02-14 01:15:39 -05003214 mutex_lock(&ftrace_lock);
Steven Rostedtb9df92d2011-04-28 20:32:08 -04003215
3216 if (unlikely(ftrace_disabled))
3217 goto out_unlock;
3218
Steven Rostedt265c8312009-02-13 12:43:56 -05003219 do_for_each_ftrace_rec(pg, rec) {
Steven Rostedtb9df92d2011-04-28 20:32:08 -04003220 if (ftrace_match_record(rec, mod, search, search_len, type)) {
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003221 ret = enter_record(hash, rec, not);
Steven Rostedtb448c4e2011-04-29 15:12:32 -04003222 if (ret < 0) {
3223 found = ret;
3224 goto out_unlock;
3225 }
Li Zefan311d16d2009-12-08 11:15:11 +08003226 found = 1;
Steven Rostedt265c8312009-02-13 12:43:56 -05003227 }
3228 } while_for_each_ftrace_rec();
Steven Rostedtb9df92d2011-04-28 20:32:08 -04003229 out_unlock:
Steven Rostedt52baf112009-02-14 01:15:39 -05003230 mutex_unlock(&ftrace_lock);
Li Zefan311d16d2009-12-08 11:15:11 +08003231
3232 return found;
Steven Rostedt5072c592008-05-12 21:20:43 +02003233}
3234
Steven Rostedt64e7c442009-02-13 17:08:48 -05003235static int
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003236ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
Steven Rostedt64e7c442009-02-13 17:08:48 -05003237{
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003238 return match_records(hash, buff, len, NULL, 0);
Steven Rostedt64e7c442009-02-13 17:08:48 -05003239}
3240
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003241static int
3242ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod)
Steven Rostedt64e7c442009-02-13 17:08:48 -05003243{
Steven Rostedt64e7c442009-02-13 17:08:48 -05003244 int not = 0;
Steven Rostedt6a24a242009-02-17 11:20:26 -05003245
Steven Rostedt64e7c442009-02-13 17:08:48 -05003246 /* blank or '*' mean the same */
3247 if (strcmp(buff, "*") == 0)
3248 buff[0] = 0;
3249
3250 /* handle the case of 'dont filter this module' */
3251 if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) {
3252 buff[0] = 0;
3253 not = 1;
3254 }
3255
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003256 return match_records(hash, buff, strlen(buff), mod, not);
Steven Rostedt64e7c442009-02-13 17:08:48 -05003257}
3258
Steven Rostedtf6180772009-02-14 00:40:25 -05003259/*
3260 * We register the module command as a template to show others how
3261 * to register the a command as well.
3262 */
3263
3264static int
Steven Rostedt43dd61c2011-07-07 11:09:22 -04003265ftrace_mod_callback(struct ftrace_hash *hash,
3266 char *func, char *cmd, char *param, int enable)
Steven Rostedtf6180772009-02-14 00:40:25 -05003267{
3268 char *mod;
Steven Rostedtb448c4e2011-04-29 15:12:32 -04003269 int ret = -EINVAL;
Steven Rostedtf6180772009-02-14 00:40:25 -05003270
3271 /*
3272 * cmd == 'mod' because we only registered this func
3273 * for the 'mod' ftrace_func_command.
3274 * But if you register one func with multiple commands,
3275 * you can tell which command was used by the cmd
3276 * parameter.
3277 */
3278
3279 /* we must have a module name */
3280 if (!param)
Steven Rostedtb448c4e2011-04-29 15:12:32 -04003281 return ret;
Steven Rostedtf6180772009-02-14 00:40:25 -05003282
3283 mod = strsep(&param, ":");
3284 if (!strlen(mod))
Steven Rostedtb448c4e2011-04-29 15:12:32 -04003285 return ret;
Steven Rostedtf6180772009-02-14 00:40:25 -05003286
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003287 ret = ftrace_match_module_records(hash, func, mod);
Steven Rostedtb448c4e2011-04-29 15:12:32 -04003288 if (!ret)
3289 ret = -EINVAL;
3290 if (ret < 0)
3291 return ret;
3292
3293 return 0;
Steven Rostedtf6180772009-02-14 00:40:25 -05003294}
3295
3296static struct ftrace_func_command ftrace_mod_cmd = {
3297 .name = "mod",
3298 .func = ftrace_mod_callback,
3299};
3300
3301static int __init ftrace_mod_cmd_init(void)
3302{
3303 return register_ftrace_command(&ftrace_mod_cmd);
3304}
Steven Rostedt6f415672012-10-05 12:13:07 -04003305core_initcall(ftrace_mod_cmd_init);
Steven Rostedtf6180772009-02-14 00:40:25 -05003306
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -04003307static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
Steven Rostedta1e2e312011-08-09 12:50:46 -04003308 struct ftrace_ops *op, struct pt_regs *pt_regs)
Steven Rostedt59df055f2009-02-14 15:29:06 -05003309{
Steven Rostedtb6887d72009-02-17 12:32:04 -05003310 struct ftrace_func_probe *entry;
Steven Rostedt59df055f2009-02-14 15:29:06 -05003311 struct hlist_head *hhd;
Steven Rostedt59df055f2009-02-14 15:29:06 -05003312 unsigned long key;
Steven Rostedt59df055f2009-02-14 15:29:06 -05003313
3314 key = hash_long(ip, FTRACE_HASH_BITS);
3315
3316 hhd = &ftrace_func_hash[key];
3317
3318 if (hlist_empty(hhd))
3319 return;
3320
3321 /*
3322 * Disable preemption for these calls to prevent a RCU grace
3323 * period. This syncs the hash iteration and freeing of items
3324 * on the hash. rcu_read_lock is too dangerous here.
3325 */
Steven Rostedt5168ae52010-06-03 09:36:50 -04003326 preempt_disable_notrace();
Steven Rostedt1bb539c2013-05-28 14:38:43 -04003327 hlist_for_each_entry_rcu_notrace(entry, hhd, node) {
Steven Rostedt59df055f2009-02-14 15:29:06 -05003328 if (entry->ip == ip)
3329 entry->ops->func(ip, parent_ip, &entry->data);
3330 }
Steven Rostedt5168ae52010-06-03 09:36:50 -04003331 preempt_enable_notrace();
Steven Rostedt59df055f2009-02-14 15:29:06 -05003332}
3333
Steven Rostedtb6887d72009-02-17 12:32:04 -05003334static struct ftrace_ops trace_probe_ops __read_mostly =
Steven Rostedt59df055f2009-02-14 15:29:06 -05003335{
Steven Rostedtfb9fb012009-03-25 13:26:41 -04003336 .func = function_trace_probe_call,
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +09003337 .flags = FTRACE_OPS_FL_INITIALIZED,
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003338 INIT_OPS_HASH(trace_probe_ops)
Steven Rostedt59df055f2009-02-14 15:29:06 -05003339};
3340
Steven Rostedtb6887d72009-02-17 12:32:04 -05003341static int ftrace_probe_registered;
Steven Rostedt59df055f2009-02-14 15:29:06 -05003342
Steven Rostedtb6887d72009-02-17 12:32:04 -05003343static void __enable_ftrace_function_probe(void)
Steven Rostedt59df055f2009-02-14 15:29:06 -05003344{
Steven Rostedtb8489142011-05-04 09:27:52 -04003345 int ret;
Steven Rostedt59df055f2009-02-14 15:29:06 -05003346 int i;
3347
Steven Rostedt (Red Hat)19dd6032013-05-09 19:37:36 -04003348 if (ftrace_probe_registered) {
3349 /* still need to update the function call sites */
3350 if (ftrace_enabled)
Steven Rostedt (Red Hat)e1effa02014-08-05 17:19:38 -04003351 ftrace_run_modify_code(&trace_probe_ops, FTRACE_UPDATE_CALLS);
Steven Rostedt59df055f2009-02-14 15:29:06 -05003352 return;
Steven Rostedt (Red Hat)19dd6032013-05-09 19:37:36 -04003353 }
Steven Rostedt59df055f2009-02-14 15:29:06 -05003354
3355 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
3356 struct hlist_head *hhd = &ftrace_func_hash[i];
3357 if (hhd->first)
3358 break;
3359 }
3360 /* Nothing registered? */
3361 if (i == FTRACE_FUNC_HASHSIZE)
3362 return;
3363
Steven Rostedt (Red Hat)8a56d772013-11-25 20:59:46 -05003364 ret = ftrace_startup(&trace_probe_ops, 0);
Steven Rostedtb8489142011-05-04 09:27:52 -04003365
Steven Rostedtb6887d72009-02-17 12:32:04 -05003366 ftrace_probe_registered = 1;
Steven Rostedt59df055f2009-02-14 15:29:06 -05003367}
3368
Steven Rostedtb6887d72009-02-17 12:32:04 -05003369static void __disable_ftrace_function_probe(void)
Steven Rostedt59df055f2009-02-14 15:29:06 -05003370{
3371 int i;
3372
Steven Rostedtb6887d72009-02-17 12:32:04 -05003373 if (!ftrace_probe_registered)
Steven Rostedt59df055f2009-02-14 15:29:06 -05003374 return;
3375
3376 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
3377 struct hlist_head *hhd = &ftrace_func_hash[i];
3378 if (hhd->first)
3379 return;
3380 }
3381
3382 /* no more funcs left */
Steven Rostedt (Red Hat)8a56d772013-11-25 20:59:46 -05003383 ftrace_shutdown(&trace_probe_ops, 0);
Steven Rostedtb8489142011-05-04 09:27:52 -04003384
Steven Rostedtb6887d72009-02-17 12:32:04 -05003385 ftrace_probe_registered = 0;
Steven Rostedt59df055f2009-02-14 15:29:06 -05003386}
3387
3388
Steven Rostedt (Red Hat)7818b382013-03-13 12:42:58 -04003389static void ftrace_free_entry(struct ftrace_func_probe *entry)
Steven Rostedt59df055f2009-02-14 15:29:06 -05003390{
Steven Rostedt59df055f2009-02-14 15:29:06 -05003391 if (entry->ops->free)
Steven Rostedt (Red Hat)e67efb92013-03-12 15:07:59 -04003392 entry->ops->free(entry->ops, entry->ip, &entry->data);
Steven Rostedt59df055f2009-02-14 15:29:06 -05003393 kfree(entry);
3394}
3395
Steven Rostedt59df055f2009-02-14 15:29:06 -05003396int
Steven Rostedtb6887d72009-02-17 12:32:04 -05003397register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
Steven Rostedt59df055f2009-02-14 15:29:06 -05003398 void *data)
3399{
Steven Rostedtb6887d72009-02-17 12:32:04 -05003400 struct ftrace_func_probe *entry;
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003401 struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash;
Steven Rostedt (Red Hat)3296fc4e2014-07-24 15:33:41 -04003402 struct ftrace_hash *old_hash = *orig_hash;
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003403 struct ftrace_hash *hash;
Steven Rostedt59df055f2009-02-14 15:29:06 -05003404 struct ftrace_page *pg;
3405 struct dyn_ftrace *rec;
Steven Rostedt59df055f2009-02-14 15:29:06 -05003406 int type, len, not;
Steven Rostedt6a24a242009-02-17 11:20:26 -05003407 unsigned long key;
Steven Rostedt59df055f2009-02-14 15:29:06 -05003408 int count = 0;
3409 char *search;
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003410 int ret;
Steven Rostedt59df055f2009-02-14 15:29:06 -05003411
Frederic Weisbecker3f6fe062009-09-24 21:31:51 +02003412 type = filter_parse_regex(glob, strlen(glob), &search, &not);
Steven Rostedt59df055f2009-02-14 15:29:06 -05003413 len = strlen(search);
3414
Steven Rostedtb6887d72009-02-17 12:32:04 -05003415 /* we do not support '!' for function probes */
Steven Rostedt59df055f2009-02-14 15:29:06 -05003416 if (WARN_ON(not))
3417 return -EINVAL;
3418
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003419 mutex_lock(&trace_probe_ops.func_hash->regex_lock);
Steven Rostedt59df055f2009-02-14 15:29:06 -05003420
Steven Rostedt (Red Hat)3296fc4e2014-07-24 15:33:41 -04003421 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003422 if (!hash) {
3423 count = -ENOMEM;
Steven Rostedt (Red Hat)5ae0bf52013-05-09 18:20:37 -04003424 goto out;
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003425 }
3426
3427 if (unlikely(ftrace_disabled)) {
3428 count = -ENODEV;
Steven Rostedt (Red Hat)5ae0bf52013-05-09 18:20:37 -04003429 goto out;
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003430 }
Steven Rostedt45a4a232011-04-21 23:16:46 -04003431
Steven Rostedt (Red Hat)5ae0bf52013-05-09 18:20:37 -04003432 mutex_lock(&ftrace_lock);
3433
Steven Rostedt59df055f2009-02-14 15:29:06 -05003434 do_for_each_ftrace_rec(pg, rec) {
3435
Steven Rostedtb9df92d2011-04-28 20:32:08 -04003436 if (!ftrace_match_record(rec, NULL, search, len, type))
Steven Rostedt59df055f2009-02-14 15:29:06 -05003437 continue;
3438
3439 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
3440 if (!entry) {
Steven Rostedtb6887d72009-02-17 12:32:04 -05003441 /* If we did not process any, then return error */
Steven Rostedt59df055f2009-02-14 15:29:06 -05003442 if (!count)
3443 count = -ENOMEM;
3444 goto out_unlock;
3445 }
3446
3447 count++;
3448
3449 entry->data = data;
3450
3451 /*
3452 * The caller might want to do something special
3453 * for each function we find. We call the callback
3454 * to give the caller an opportunity to do so.
3455 */
Steven Rostedt (Red Hat)e67efb92013-03-12 15:07:59 -04003456 if (ops->init) {
3457 if (ops->init(ops, rec->ip, &entry->data) < 0) {
Steven Rostedt59df055f2009-02-14 15:29:06 -05003458 /* caller does not like this func */
3459 kfree(entry);
3460 continue;
3461 }
3462 }
3463
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003464 ret = enter_record(hash, rec, 0);
3465 if (ret < 0) {
3466 kfree(entry);
3467 count = ret;
3468 goto out_unlock;
3469 }
3470
Steven Rostedt59df055f2009-02-14 15:29:06 -05003471 entry->ops = ops;
3472 entry->ip = rec->ip;
3473
3474 key = hash_long(entry->ip, FTRACE_HASH_BITS);
3475 hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]);
3476
3477 } while_for_each_ftrace_rec();
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003478
3479 ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash);
Steven Rostedt (Red Hat)3296fc4e2014-07-24 15:33:41 -04003480 if (!ret)
3481 free_ftrace_hash_rcu(old_hash);
3482 else
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003483 count = ret;
3484
Steven Rostedtb6887d72009-02-17 12:32:04 -05003485 __enable_ftrace_function_probe();
Steven Rostedt59df055f2009-02-14 15:29:06 -05003486
3487 out_unlock:
Steven Rostedt (Red Hat)5ae0bf52013-05-09 18:20:37 -04003488 mutex_unlock(&ftrace_lock);
3489 out:
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003490 mutex_unlock(&trace_probe_ops.func_hash->regex_lock);
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003491 free_ftrace_hash(hash);
Steven Rostedt59df055f2009-02-14 15:29:06 -05003492
3493 return count;
3494}
3495
3496enum {
Steven Rostedtb6887d72009-02-17 12:32:04 -05003497 PROBE_TEST_FUNC = 1,
3498 PROBE_TEST_DATA = 2
Steven Rostedt59df055f2009-02-14 15:29:06 -05003499};
3500
3501static void
Steven Rostedtb6887d72009-02-17 12:32:04 -05003502__unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
Steven Rostedt59df055f2009-02-14 15:29:06 -05003503 void *data, int flags)
3504{
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003505 struct ftrace_func_entry *rec_entry;
Steven Rostedtb6887d72009-02-17 12:32:04 -05003506 struct ftrace_func_probe *entry;
Steven Rostedt (Red Hat)7818b382013-03-13 12:42:58 -04003507 struct ftrace_func_probe *p;
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003508 struct ftrace_hash **orig_hash = &trace_probe_ops.func_hash->filter_hash;
Steven Rostedt (Red Hat)3296fc4e2014-07-24 15:33:41 -04003509 struct ftrace_hash *old_hash = *orig_hash;
Steven Rostedt (Red Hat)7818b382013-03-13 12:42:58 -04003510 struct list_head free_list;
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003511 struct ftrace_hash *hash;
Sasha Levinb67bfe02013-02-27 17:06:00 -08003512 struct hlist_node *tmp;
Steven Rostedt59df055f2009-02-14 15:29:06 -05003513 char str[KSYM_SYMBOL_LEN];
3514 int type = MATCH_FULL;
3515 int i, len = 0;
3516 char *search;
Steven Rostedt (Red Hat)3296fc4e2014-07-24 15:33:41 -04003517 int ret;
Steven Rostedt59df055f2009-02-14 15:29:06 -05003518
Atsushi Tsujib36461d2009-09-15 19:06:30 +09003519 if (glob && (strcmp(glob, "*") == 0 || !strlen(glob)))
Steven Rostedt59df055f2009-02-14 15:29:06 -05003520 glob = NULL;
Atsushi Tsujib36461d2009-09-15 19:06:30 +09003521 else if (glob) {
Steven Rostedt59df055f2009-02-14 15:29:06 -05003522 int not;
3523
Frederic Weisbecker3f6fe062009-09-24 21:31:51 +02003524 type = filter_parse_regex(glob, strlen(glob), &search, &not);
Steven Rostedt59df055f2009-02-14 15:29:06 -05003525 len = strlen(search);
3526
Steven Rostedtb6887d72009-02-17 12:32:04 -05003527 /* we do not support '!' for function probes */
Steven Rostedt59df055f2009-02-14 15:29:06 -05003528 if (WARN_ON(not))
3529 return;
3530 }
3531
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003532 mutex_lock(&trace_probe_ops.func_hash->regex_lock);
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003533
3534 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
3535 if (!hash)
3536 /* Hmm, should report this somehow */
3537 goto out_unlock;
3538
Steven Rostedt (Red Hat)7818b382013-03-13 12:42:58 -04003539 INIT_LIST_HEAD(&free_list);
3540
Steven Rostedt59df055f2009-02-14 15:29:06 -05003541 for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
3542 struct hlist_head *hhd = &ftrace_func_hash[i];
3543
Sasha Levinb67bfe02013-02-27 17:06:00 -08003544 hlist_for_each_entry_safe(entry, tmp, hhd, node) {
Steven Rostedt59df055f2009-02-14 15:29:06 -05003545
3546 /* break up if statements for readability */
Steven Rostedtb6887d72009-02-17 12:32:04 -05003547 if ((flags & PROBE_TEST_FUNC) && entry->ops != ops)
Steven Rostedt59df055f2009-02-14 15:29:06 -05003548 continue;
3549
Steven Rostedtb6887d72009-02-17 12:32:04 -05003550 if ((flags & PROBE_TEST_DATA) && entry->data != data)
Steven Rostedt59df055f2009-02-14 15:29:06 -05003551 continue;
3552
3553 /* do this last, since it is the most expensive */
3554 if (glob) {
3555 kallsyms_lookup(entry->ip, NULL, NULL,
3556 NULL, str);
3557 if (!ftrace_match(str, glob, len, type))
3558 continue;
3559 }
3560
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003561 rec_entry = ftrace_lookup_ip(hash, entry->ip);
3562 /* It is possible more than one entry had this ip */
3563 if (rec_entry)
3564 free_hash_entry(hash, rec_entry);
3565
Steven Rostedt (Red Hat)740466b2013-03-13 11:15:19 -04003566 hlist_del_rcu(&entry->node);
Steven Rostedt (Red Hat)7818b382013-03-13 12:42:58 -04003567 list_add(&entry->free_list, &free_list);
Steven Rostedt59df055f2009-02-14 15:29:06 -05003568 }
3569 }
Masami Hiramatsu3f2367b2013-05-09 14:44:21 +09003570 mutex_lock(&ftrace_lock);
Steven Rostedtb6887d72009-02-17 12:32:04 -05003571 __disable_ftrace_function_probe();
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003572 /*
3573 * Remove after the disable is called. Otherwise, if the last
3574 * probe is removed, a null hash means *all enabled*.
3575 */
Steven Rostedt (Red Hat)3296fc4e2014-07-24 15:33:41 -04003576 ret = ftrace_hash_move(&trace_probe_ops, 1, orig_hash, hash);
Steven Rostedt (Red Hat)7818b382013-03-13 12:42:58 -04003577 synchronize_sched();
Steven Rostedt (Red Hat)3296fc4e2014-07-24 15:33:41 -04003578 if (!ret)
3579 free_ftrace_hash_rcu(old_hash);
3580
Steven Rostedt (Red Hat)7818b382013-03-13 12:42:58 -04003581 list_for_each_entry_safe(entry, p, &free_list, free_list) {
3582 list_del(&entry->free_list);
3583 ftrace_free_entry(entry);
3584 }
Masami Hiramatsu3f2367b2013-05-09 14:44:21 +09003585 mutex_unlock(&ftrace_lock);
Steven Rostedt (Red Hat)7818b382013-03-13 12:42:58 -04003586
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003587 out_unlock:
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003588 mutex_unlock(&trace_probe_ops.func_hash->regex_lock);
Steven Rostedt (Red Hat)e1df4cb2013-03-12 10:09:42 -04003589 free_ftrace_hash(hash);
Steven Rostedt59df055f2009-02-14 15:29:06 -05003590}
3591
3592void
Steven Rostedtb6887d72009-02-17 12:32:04 -05003593unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
Steven Rostedt59df055f2009-02-14 15:29:06 -05003594 void *data)
3595{
Steven Rostedtb6887d72009-02-17 12:32:04 -05003596 __unregister_ftrace_function_probe(glob, ops, data,
3597 PROBE_TEST_FUNC | PROBE_TEST_DATA);
Steven Rostedt59df055f2009-02-14 15:29:06 -05003598}
3599
3600void
Steven Rostedtb6887d72009-02-17 12:32:04 -05003601unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops)
Steven Rostedt59df055f2009-02-14 15:29:06 -05003602{
Steven Rostedtb6887d72009-02-17 12:32:04 -05003603 __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC);
Steven Rostedt59df055f2009-02-14 15:29:06 -05003604}
3605
Steven Rostedtb6887d72009-02-17 12:32:04 -05003606void unregister_ftrace_function_probe_all(char *glob)
Steven Rostedt59df055f2009-02-14 15:29:06 -05003607{
Steven Rostedtb6887d72009-02-17 12:32:04 -05003608 __unregister_ftrace_function_probe(glob, NULL, NULL, 0);
Steven Rostedt59df055f2009-02-14 15:29:06 -05003609}
3610
Steven Rostedtf6180772009-02-14 00:40:25 -05003611static LIST_HEAD(ftrace_commands);
3612static DEFINE_MUTEX(ftrace_cmd_mutex);
3613
Tom Zanussi38de93a2013-10-24 08:34:18 -05003614/*
3615 * Currently we only register ftrace commands from __init, so mark this
3616 * __init too.
3617 */
3618__init int register_ftrace_command(struct ftrace_func_command *cmd)
Steven Rostedtf6180772009-02-14 00:40:25 -05003619{
3620 struct ftrace_func_command *p;
3621 int ret = 0;
3622
3623 mutex_lock(&ftrace_cmd_mutex);
3624 list_for_each_entry(p, &ftrace_commands, list) {
3625 if (strcmp(cmd->name, p->name) == 0) {
3626 ret = -EBUSY;
3627 goto out_unlock;
3628 }
3629 }
3630 list_add(&cmd->list, &ftrace_commands);
3631 out_unlock:
3632 mutex_unlock(&ftrace_cmd_mutex);
3633
3634 return ret;
3635}
3636
Tom Zanussi38de93a2013-10-24 08:34:18 -05003637/*
3638 * Currently we only unregister ftrace commands from __init, so mark
3639 * this __init too.
3640 */
3641__init int unregister_ftrace_command(struct ftrace_func_command *cmd)
Steven Rostedtf6180772009-02-14 00:40:25 -05003642{
3643 struct ftrace_func_command *p, *n;
3644 int ret = -ENODEV;
3645
3646 mutex_lock(&ftrace_cmd_mutex);
3647 list_for_each_entry_safe(p, n, &ftrace_commands, list) {
3648 if (strcmp(cmd->name, p->name) == 0) {
3649 ret = 0;
3650 list_del_init(&p->list);
3651 goto out_unlock;
3652 }
3653 }
3654 out_unlock:
3655 mutex_unlock(&ftrace_cmd_mutex);
3656
3657 return ret;
3658}
3659
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003660static int ftrace_process_regex(struct ftrace_hash *hash,
3661 char *buff, int len, int enable)
Steven Rostedt64e7c442009-02-13 17:08:48 -05003662{
Steven Rostedtf6180772009-02-14 00:40:25 -05003663 char *func, *command, *next = buff;
Steven Rostedt6a24a242009-02-17 11:20:26 -05003664 struct ftrace_func_command *p;
GuoWen Li0aff1c02011-06-01 19:18:47 +08003665 int ret = -EINVAL;
Steven Rostedt64e7c442009-02-13 17:08:48 -05003666
3667 func = strsep(&next, ":");
3668
3669 if (!next) {
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04003670 ret = ftrace_match_records(hash, func, len);
Steven Rostedtb448c4e2011-04-29 15:12:32 -04003671 if (!ret)
3672 ret = -EINVAL;
3673 if (ret < 0)
3674 return ret;
3675 return 0;
Steven Rostedt64e7c442009-02-13 17:08:48 -05003676 }
3677
Steven Rostedtf6180772009-02-14 00:40:25 -05003678 /* command found */
Steven Rostedt64e7c442009-02-13 17:08:48 -05003679
3680 command = strsep(&next, ":");
3681
Steven Rostedtf6180772009-02-14 00:40:25 -05003682 mutex_lock(&ftrace_cmd_mutex);
3683 list_for_each_entry(p, &ftrace_commands, list) {
3684 if (strcmp(p->name, command) == 0) {
Steven Rostedt43dd61c2011-07-07 11:09:22 -04003685 ret = p->func(hash, func, command, next, enable);
Steven Rostedtf6180772009-02-14 00:40:25 -05003686 goto out_unlock;
3687 }
Steven Rostedt64e7c442009-02-13 17:08:48 -05003688 }
Steven Rostedtf6180772009-02-14 00:40:25 -05003689 out_unlock:
3690 mutex_unlock(&ftrace_cmd_mutex);
Steven Rostedt64e7c442009-02-13 17:08:48 -05003691
Steven Rostedtf6180772009-02-14 00:40:25 -05003692 return ret;
Steven Rostedt64e7c442009-02-13 17:08:48 -05003693}
3694
Ingo Molnare309b412008-05-12 21:20:51 +02003695static ssize_t
Steven Rostedt41c52c02008-05-22 11:46:33 -04003696ftrace_regex_write(struct file *file, const char __user *ubuf,
3697 size_t cnt, loff_t *ppos, int enable)
Steven Rostedt5072c592008-05-12 21:20:43 +02003698{
3699 struct ftrace_iterator *iter;
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02003700 struct trace_parser *parser;
3701 ssize_t ret, read;
Steven Rostedt5072c592008-05-12 21:20:43 +02003702
Li Zefan4ba79782009-09-22 13:52:20 +08003703 if (!cnt)
Steven Rostedt5072c592008-05-12 21:20:43 +02003704 return 0;
3705
Steven Rostedt5072c592008-05-12 21:20:43 +02003706 if (file->f_mode & FMODE_READ) {
3707 struct seq_file *m = file->private_data;
3708 iter = m->private;
3709 } else
3710 iter = file->private_data;
3711
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +09003712 if (unlikely(ftrace_disabled))
Masami Hiramatsu3f2367b2013-05-09 14:44:21 +09003713 return -ENODEV;
3714
3715 /* iter->hash is a local copy, so we don't need regex_lock */
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +09003716
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02003717 parser = &iter->parser;
3718 read = trace_get_user(parser, ubuf, cnt, ppos);
Steven Rostedt5072c592008-05-12 21:20:43 +02003719
Li Zefan4ba79782009-09-22 13:52:20 +08003720 if (read >= 0 && trace_parser_loaded(parser) &&
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02003721 !trace_parser_cont(parser)) {
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003722 ret = ftrace_process_regex(iter->hash, parser->buffer,
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02003723 parser->idx, enable);
Li Zefan313254a2009-12-08 11:15:30 +08003724 trace_parser_clear(parser);
Steven Rostedt (Red Hat)7c088b52013-05-09 11:35:12 -04003725 if (ret < 0)
Masami Hiramatsu3f2367b2013-05-09 14:44:21 +09003726 goto out;
Steven Rostedt5072c592008-05-12 21:20:43 +02003727 }
3728
Steven Rostedt5072c592008-05-12 21:20:43 +02003729 ret = read;
Masami Hiramatsu3f2367b2013-05-09 14:44:21 +09003730 out:
Steven Rostedt5072c592008-05-12 21:20:43 +02003731 return ret;
3732}
3733
Steven Rostedtfc13cb02011-12-19 14:41:25 -05003734ssize_t
Steven Rostedt41c52c02008-05-22 11:46:33 -04003735ftrace_filter_write(struct file *file, const char __user *ubuf,
3736 size_t cnt, loff_t *ppos)
3737{
3738 return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
3739}
3740
Steven Rostedtfc13cb02011-12-19 14:41:25 -05003741ssize_t
Steven Rostedt41c52c02008-05-22 11:46:33 -04003742ftrace_notrace_write(struct file *file, const char __user *ubuf,
3743 size_t cnt, loff_t *ppos)
3744{
3745 return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
3746}
3747
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003748static int
Masami Hiramatsu647664e2012-06-05 19:28:08 +09003749ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
3750{
3751 struct ftrace_func_entry *entry;
3752
3753 if (!ftrace_location(ip))
3754 return -EINVAL;
3755
3756 if (remove) {
3757 entry = ftrace_lookup_ip(hash, ip);
3758 if (!entry)
3759 return -ENOENT;
3760 free_hash_entry(hash, entry);
3761 return 0;
3762 }
3763
3764 return add_hash_entry(hash, ip);
3765}
3766
Steven Rostedt (Red Hat)1c80c432013-07-25 20:22:00 -04003767static void ftrace_ops_update_code(struct ftrace_ops *ops)
3768{
3769 if (ops->flags & FTRACE_OPS_FL_ENABLED && ftrace_enabled)
Steven Rostedt (Red Hat)e1effa02014-08-05 17:19:38 -04003770 ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS);
Steven Rostedt (Red Hat)1c80c432013-07-25 20:22:00 -04003771}
3772
Masami Hiramatsu647664e2012-06-05 19:28:08 +09003773static int
3774ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
3775 unsigned long ip, int remove, int reset, int enable)
Steven Rostedt41c52c02008-05-22 11:46:33 -04003776{
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003777 struct ftrace_hash **orig_hash;
Steven Rostedt (Red Hat)3296fc4e2014-07-24 15:33:41 -04003778 struct ftrace_hash *old_hash;
Steven Rostedtf45948e2011-05-02 12:29:25 -04003779 struct ftrace_hash *hash;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003780 int ret;
Steven Rostedtf45948e2011-05-02 12:29:25 -04003781
Steven Rostedt41c52c02008-05-22 11:46:33 -04003782 if (unlikely(ftrace_disabled))
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003783 return -ENODEV;
Steven Rostedt41c52c02008-05-22 11:46:33 -04003784
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003785 mutex_lock(&ops->func_hash->regex_lock);
Masami Hiramatsu3f2367b2013-05-09 14:44:21 +09003786
Steven Rostedtf45948e2011-05-02 12:29:25 -04003787 if (enable)
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003788 orig_hash = &ops->func_hash->filter_hash;
Steven Rostedtf45948e2011-05-02 12:29:25 -04003789 else
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003790 orig_hash = &ops->func_hash->notrace_hash;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003791
Wang Nanb972cc52014-07-15 08:40:20 +08003792 if (reset)
3793 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
3794 else
3795 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
3796
Masami Hiramatsu3f2367b2013-05-09 14:44:21 +09003797 if (!hash) {
3798 ret = -ENOMEM;
3799 goto out_regex_unlock;
3800 }
Steven Rostedtf45948e2011-05-02 12:29:25 -04003801
Jiri Olsaac483c42012-01-02 10:04:14 +01003802 if (buf && !ftrace_match_records(hash, buf, len)) {
3803 ret = -EINVAL;
3804 goto out_regex_unlock;
3805 }
Masami Hiramatsu647664e2012-06-05 19:28:08 +09003806 if (ip) {
3807 ret = ftrace_match_addr(hash, ip, remove);
3808 if (ret < 0)
3809 goto out_regex_unlock;
3810 }
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003811
3812 mutex_lock(&ftrace_lock);
Steven Rostedt (Red Hat)3296fc4e2014-07-24 15:33:41 -04003813 old_hash = *orig_hash;
Steven Rostedt41fb61c2011-07-13 15:03:44 -04003814 ret = ftrace_hash_move(ops, enable, orig_hash, hash);
Steven Rostedt (Red Hat)3296fc4e2014-07-24 15:33:41 -04003815 if (!ret) {
Steven Rostedt (Red Hat)1c80c432013-07-25 20:22:00 -04003816 ftrace_ops_update_code(ops);
Steven Rostedt (Red Hat)3296fc4e2014-07-24 15:33:41 -04003817 free_ftrace_hash_rcu(old_hash);
3818 }
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003819 mutex_unlock(&ftrace_lock);
3820
Jiri Olsaac483c42012-01-02 10:04:14 +01003821 out_regex_unlock:
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04003822 mutex_unlock(&ops->func_hash->regex_lock);
Steven Rostedt33dc9b12011-05-02 17:34:47 -04003823
3824 free_ftrace_hash(hash);
3825 return ret;
Steven Rostedt41c52c02008-05-22 11:46:33 -04003826}
3827
Masami Hiramatsu647664e2012-06-05 19:28:08 +09003828static int
3829ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove,
3830 int reset, int enable)
3831{
3832 return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable);
3833}
3834
3835/**
3836 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
3837 * @ops - the ops to set the filter with
3838 * @ip - the address to add to or remove from the filter.
3839 * @remove - non zero to remove the ip from the filter
3840 * @reset - non zero to reset all filters before applying this filter.
3841 *
3842 * Filters denote which functions should be enabled when tracing is enabled
3843 * If @ip is NULL, it failes to update filter.
3844 */
3845int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
3846 int remove, int reset)
3847{
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +09003848 ftrace_ops_init(ops);
Masami Hiramatsu647664e2012-06-05 19:28:08 +09003849 return ftrace_set_addr(ops, ip, remove, reset, 1);
3850}
3851EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
3852
3853static int
3854ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
3855 int reset, int enable)
3856{
3857 return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable);
3858}
3859
Steven Rostedt77a2b372008-05-12 21:20:45 +02003860/**
3861 * ftrace_set_filter - set a function to filter on in ftrace
Steven Rostedt936e0742011-05-05 22:54:01 -04003862 * @ops - the ops to set the filter with
Steven Rostedt77a2b372008-05-12 21:20:45 +02003863 * @buf - the string that holds the function filter text.
3864 * @len - the length of the string.
3865 * @reset - non zero to reset all filters before applying this filter.
3866 *
3867 * Filters denote which functions should be enabled when tracing is enabled.
3868 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
3869 */
Jiri Olsaac483c42012-01-02 10:04:14 +01003870int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
Steven Rostedt936e0742011-05-05 22:54:01 -04003871 int len, int reset)
Steven Rostedt77a2b372008-05-12 21:20:45 +02003872{
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +09003873 ftrace_ops_init(ops);
Jiri Olsaac483c42012-01-02 10:04:14 +01003874 return ftrace_set_regex(ops, buf, len, reset, 1);
Steven Rostedt41c52c02008-05-22 11:46:33 -04003875}
Steven Rostedt936e0742011-05-05 22:54:01 -04003876EXPORT_SYMBOL_GPL(ftrace_set_filter);
Steven Rostedt4eebcc82008-05-12 21:20:48 +02003877
Steven Rostedt41c52c02008-05-22 11:46:33 -04003878/**
3879 * ftrace_set_notrace - set a function to not trace in ftrace
Steven Rostedt936e0742011-05-05 22:54:01 -04003880 * @ops - the ops to set the notrace filter with
Steven Rostedt41c52c02008-05-22 11:46:33 -04003881 * @buf - the string that holds the function notrace text.
3882 * @len - the length of the string.
3883 * @reset - non zero to reset all filters before applying this filter.
3884 *
3885 * Notrace Filters denote which functions should not be enabled when tracing
3886 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
3887 * for tracing.
3888 */
Jiri Olsaac483c42012-01-02 10:04:14 +01003889int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
Steven Rostedt936e0742011-05-05 22:54:01 -04003890 int len, int reset)
3891{
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +09003892 ftrace_ops_init(ops);
Jiri Olsaac483c42012-01-02 10:04:14 +01003893 return ftrace_set_regex(ops, buf, len, reset, 0);
Steven Rostedt936e0742011-05-05 22:54:01 -04003894}
3895EXPORT_SYMBOL_GPL(ftrace_set_notrace);
3896/**
Jiaxing Wang8d1b0652014-04-20 23:10:44 +08003897 * ftrace_set_global_filter - set a function to filter on with global tracers
Steven Rostedt936e0742011-05-05 22:54:01 -04003898 * @buf - the string that holds the function filter text.
3899 * @len - the length of the string.
3900 * @reset - non zero to reset all filters before applying this filter.
3901 *
3902 * Filters denote which functions should be enabled when tracing is enabled.
3903 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
3904 */
3905void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
3906{
3907 ftrace_set_regex(&global_ops, buf, len, reset, 1);
3908}
3909EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
3910
3911/**
Jiaxing Wang8d1b0652014-04-20 23:10:44 +08003912 * ftrace_set_global_notrace - set a function to not trace with global tracers
Steven Rostedt936e0742011-05-05 22:54:01 -04003913 * @buf - the string that holds the function notrace text.
3914 * @len - the length of the string.
3915 * @reset - non zero to reset all filters before applying this filter.
3916 *
3917 * Notrace Filters denote which functions should not be enabled when tracing
3918 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
3919 * for tracing.
3920 */
3921void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
Steven Rostedt41c52c02008-05-22 11:46:33 -04003922{
Steven Rostedtf45948e2011-05-02 12:29:25 -04003923 ftrace_set_regex(&global_ops, buf, len, reset, 0);
Steven Rostedt77a2b372008-05-12 21:20:45 +02003924}
Steven Rostedt936e0742011-05-05 22:54:01 -04003925EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
Steven Rostedt77a2b372008-05-12 21:20:45 +02003926
Steven Rostedt2af15d62009-05-28 13:37:24 -04003927/*
3928 * command line interface to allow users to set filters on boot up.
3929 */
3930#define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
3931static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
3932static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
3933
Steven Rostedt (Red Hat)f1ed7c72013-06-27 22:18:06 -04003934/* Used by function selftest to not test if filter is set */
3935bool ftrace_filter_param __initdata;
3936
Steven Rostedt2af15d62009-05-28 13:37:24 -04003937static int __init set_ftrace_notrace(char *str)
3938{
Steven Rostedt (Red Hat)f1ed7c72013-06-27 22:18:06 -04003939 ftrace_filter_param = true;
Chen Gang75761cc2013-04-08 12:12:39 +08003940 strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
Steven Rostedt2af15d62009-05-28 13:37:24 -04003941 return 1;
3942}
3943__setup("ftrace_notrace=", set_ftrace_notrace);
3944
3945static int __init set_ftrace_filter(char *str)
3946{
Steven Rostedt (Red Hat)f1ed7c72013-06-27 22:18:06 -04003947 ftrace_filter_param = true;
Chen Gang75761cc2013-04-08 12:12:39 +08003948 strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
Steven Rostedt2af15d62009-05-28 13:37:24 -04003949 return 1;
3950}
3951__setup("ftrace_filter=", set_ftrace_filter);
3952
Stefan Assmann369bc182009-10-12 22:17:21 +02003953#ifdef CONFIG_FUNCTION_GRAPH_TRACER
Lai Jiangshanf6060f42009-11-05 11:16:17 +08003954static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
Namhyung Kim0d7d9a12014-06-13 01:23:50 +09003955static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
Namhyung Kimfaf982a2013-10-14 17:24:24 +09003956static int ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer);
Steven Rostedt801c29f2010-03-05 20:02:19 -05003957
Stefan Assmann369bc182009-10-12 22:17:21 +02003958static int __init set_graph_function(char *str)
3959{
Frederic Weisbecker06f43d62009-10-14 20:43:39 +02003960 strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
Stefan Assmann369bc182009-10-12 22:17:21 +02003961 return 1;
3962}
3963__setup("ftrace_graph_filter=", set_graph_function);
3964
Namhyung Kim0d7d9a12014-06-13 01:23:50 +09003965static int __init set_graph_notrace_function(char *str)
3966{
3967 strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE);
3968 return 1;
3969}
3970__setup("ftrace_graph_notrace=", set_graph_notrace_function);
3971
3972static void __init set_ftrace_early_graph(char *buf, int enable)
Stefan Assmann369bc182009-10-12 22:17:21 +02003973{
3974 int ret;
3975 char *func;
Namhyung Kim0d7d9a12014-06-13 01:23:50 +09003976 unsigned long *table = ftrace_graph_funcs;
3977 int *count = &ftrace_graph_count;
3978
3979 if (!enable) {
3980 table = ftrace_graph_notrace_funcs;
3981 count = &ftrace_graph_notrace_count;
3982 }
Stefan Assmann369bc182009-10-12 22:17:21 +02003983
3984 while (buf) {
3985 func = strsep(&buf, ",");
3986 /* we allow only one expression at a time */
Namhyung Kim0d7d9a12014-06-13 01:23:50 +09003987 ret = ftrace_set_func(table, count, FTRACE_GRAPH_MAX_FUNCS, func);
Stefan Assmann369bc182009-10-12 22:17:21 +02003988 if (ret)
3989 printk(KERN_DEBUG "ftrace: function %s not "
3990 "traceable\n", func);
3991 }
3992}
3993#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
3994
Steven Rostedt2a85a372011-12-19 21:57:44 -05003995void __init
3996ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable)
Steven Rostedt2af15d62009-05-28 13:37:24 -04003997{
3998 char *func;
3999
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +09004000 ftrace_ops_init(ops);
4001
Steven Rostedt2af15d62009-05-28 13:37:24 -04004002 while (buf) {
4003 func = strsep(&buf, ",");
Steven Rostedtf45948e2011-05-02 12:29:25 -04004004 ftrace_set_regex(ops, func, strlen(func), 0, enable);
Steven Rostedt2af15d62009-05-28 13:37:24 -04004005 }
4006}
4007
4008static void __init set_ftrace_early_filters(void)
4009{
4010 if (ftrace_filter_buf[0])
Steven Rostedt2a85a372011-12-19 21:57:44 -05004011 ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1);
Steven Rostedt2af15d62009-05-28 13:37:24 -04004012 if (ftrace_notrace_buf[0])
Steven Rostedt2a85a372011-12-19 21:57:44 -05004013 ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0);
Stefan Assmann369bc182009-10-12 22:17:21 +02004014#ifdef CONFIG_FUNCTION_GRAPH_TRACER
4015 if (ftrace_graph_buf[0])
Namhyung Kim0d7d9a12014-06-13 01:23:50 +09004016 set_ftrace_early_graph(ftrace_graph_buf, 1);
4017 if (ftrace_graph_notrace_buf[0])
4018 set_ftrace_early_graph(ftrace_graph_notrace_buf, 0);
Stefan Assmann369bc182009-10-12 22:17:21 +02004019#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
Steven Rostedt2af15d62009-05-28 13:37:24 -04004020}
4021
Steven Rostedtfc13cb02011-12-19 14:41:25 -05004022int ftrace_regex_release(struct inode *inode, struct file *file)
Steven Rostedt5072c592008-05-12 21:20:43 +02004023{
4024 struct seq_file *m = (struct seq_file *)file->private_data;
4025 struct ftrace_iterator *iter;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04004026 struct ftrace_hash **orig_hash;
Steven Rostedt (Red Hat)3296fc4e2014-07-24 15:33:41 -04004027 struct ftrace_hash *old_hash;
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02004028 struct trace_parser *parser;
Steven Rostedted926f92011-05-03 13:25:24 -04004029 int filter_hash;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04004030 int ret;
Steven Rostedt5072c592008-05-12 21:20:43 +02004031
Steven Rostedt5072c592008-05-12 21:20:43 +02004032 if (file->f_mode & FMODE_READ) {
4033 iter = m->private;
Steven Rostedt5072c592008-05-12 21:20:43 +02004034 seq_release(inode, file);
4035 } else
4036 iter = file->private_data;
4037
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02004038 parser = &iter->parser;
4039 if (trace_parser_loaded(parser)) {
4040 parser->buffer[parser->idx] = 0;
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04004041 ftrace_match_records(iter->hash, parser->buffer, parser->idx);
Steven Rostedt5072c592008-05-12 21:20:43 +02004042 }
4043
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02004044 trace_parser_put(parser);
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02004045
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04004046 mutex_lock(&iter->ops->func_hash->regex_lock);
Masami Hiramatsu3f2367b2013-05-09 14:44:21 +09004047
Steven Rostedt058e2972011-04-29 22:35:33 -04004048 if (file->f_mode & FMODE_WRITE) {
Steven Rostedted926f92011-05-03 13:25:24 -04004049 filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
4050
4051 if (filter_hash)
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04004052 orig_hash = &iter->ops->func_hash->filter_hash;
Steven Rostedted926f92011-05-03 13:25:24 -04004053 else
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04004054 orig_hash = &iter->ops->func_hash->notrace_hash;
Steven Rostedt33dc9b12011-05-02 17:34:47 -04004055
Steven Rostedt058e2972011-04-29 22:35:33 -04004056 mutex_lock(&ftrace_lock);
Steven Rostedt (Red Hat)3296fc4e2014-07-24 15:33:41 -04004057 old_hash = *orig_hash;
Steven Rostedt41fb61c2011-07-13 15:03:44 -04004058 ret = ftrace_hash_move(iter->ops, filter_hash,
4059 orig_hash, iter->hash);
Steven Rostedt (Red Hat)3296fc4e2014-07-24 15:33:41 -04004060 if (!ret) {
Steven Rostedt (Red Hat)1c80c432013-07-25 20:22:00 -04004061 ftrace_ops_update_code(iter->ops);
Steven Rostedt (Red Hat)3296fc4e2014-07-24 15:33:41 -04004062 free_ftrace_hash_rcu(old_hash);
4063 }
Steven Rostedt058e2972011-04-29 22:35:33 -04004064 mutex_unlock(&ftrace_lock);
4065 }
Masami Hiramatsu3f2367b2013-05-09 14:44:21 +09004066
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04004067 mutex_unlock(&iter->ops->func_hash->regex_lock);
Steven Rostedt33dc9b12011-05-02 17:34:47 -04004068 free_ftrace_hash(iter->hash);
4069 kfree(iter);
Steven Rostedt058e2972011-04-29 22:35:33 -04004070
Steven Rostedt5072c592008-05-12 21:20:43 +02004071 return 0;
4072}
4073
Steven Rostedt5e2336a2009-03-05 21:44:55 -05004074static const struct file_operations ftrace_avail_fops = {
Steven Rostedt5072c592008-05-12 21:20:43 +02004075 .open = ftrace_avail_open,
4076 .read = seq_read,
4077 .llseek = seq_lseek,
Li Zefan3be04b42009-08-17 16:54:03 +08004078 .release = seq_release_private,
Steven Rostedt5072c592008-05-12 21:20:43 +02004079};
4080
Steven Rostedt647bcd02011-05-03 14:39:21 -04004081static const struct file_operations ftrace_enabled_fops = {
4082 .open = ftrace_enabled_open,
4083 .read = seq_read,
4084 .llseek = seq_lseek,
4085 .release = seq_release_private,
4086};
4087
Steven Rostedt5e2336a2009-03-05 21:44:55 -05004088static const struct file_operations ftrace_filter_fops = {
Steven Rostedt5072c592008-05-12 21:20:43 +02004089 .open = ftrace_filter_open,
Lai Jiangshan850a80c2009-03-13 17:47:23 +08004090 .read = seq_read,
Steven Rostedt5072c592008-05-12 21:20:43 +02004091 .write = ftrace_filter_write,
Steven Rostedt (Red Hat)098c879e2013-12-21 17:39:40 -05004092 .llseek = tracing_lseek,
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04004093 .release = ftrace_regex_release,
Steven Rostedt5072c592008-05-12 21:20:43 +02004094};
4095
Steven Rostedt5e2336a2009-03-05 21:44:55 -05004096static const struct file_operations ftrace_notrace_fops = {
Steven Rostedt41c52c02008-05-22 11:46:33 -04004097 .open = ftrace_notrace_open,
Lai Jiangshan850a80c2009-03-13 17:47:23 +08004098 .read = seq_read,
Steven Rostedt41c52c02008-05-22 11:46:33 -04004099 .write = ftrace_notrace_write,
Steven Rostedt (Red Hat)098c879e2013-12-21 17:39:40 -05004100 .llseek = tracing_lseek,
Steven Rostedt1cf41dd72011-04-29 20:59:51 -04004101 .release = ftrace_regex_release,
Steven Rostedt41c52c02008-05-22 11:46:33 -04004102};
4103
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004104#ifdef CONFIG_FUNCTION_GRAPH_TRACER
4105
4106static DEFINE_MUTEX(graph_lock);
4107
4108int ftrace_graph_count;
Namhyung Kim29ad23b2013-10-14 17:24:26 +09004109int ftrace_graph_notrace_count;
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004110unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
Namhyung Kim29ad23b2013-10-14 17:24:26 +09004111unsigned long ftrace_graph_notrace_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004112
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004113struct ftrace_graph_data {
4114 unsigned long *table;
4115 size_t size;
4116 int *count;
4117 const struct seq_operations *seq_ops;
4118};
4119
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004120static void *
Li Zefan85951842009-06-24 09:54:00 +08004121__g_next(struct seq_file *m, loff_t *pos)
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004122{
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004123 struct ftrace_graph_data *fgd = m->private;
4124
4125 if (*pos >= *fgd->count)
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004126 return NULL;
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004127 return &fgd->table[*pos];
Li Zefan85951842009-06-24 09:54:00 +08004128}
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004129
Li Zefan85951842009-06-24 09:54:00 +08004130static void *
4131g_next(struct seq_file *m, void *v, loff_t *pos)
4132{
4133 (*pos)++;
4134 return __g_next(m, pos);
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004135}
4136
4137static void *g_start(struct seq_file *m, loff_t *pos)
4138{
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004139 struct ftrace_graph_data *fgd = m->private;
4140
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004141 mutex_lock(&graph_lock);
4142
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01004143 /* Nothing, tell g_show to print all functions are enabled */
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004144 if (!*fgd->count && !*pos)
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01004145 return (void *)1;
4146
Li Zefan85951842009-06-24 09:54:00 +08004147 return __g_next(m, pos);
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004148}
4149
4150static void g_stop(struct seq_file *m, void *p)
4151{
4152 mutex_unlock(&graph_lock);
4153}
4154
4155static int g_show(struct seq_file *m, void *v)
4156{
4157 unsigned long *ptr = v;
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004158
4159 if (!ptr)
4160 return 0;
4161
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01004162 if (ptr == (unsigned long *)1) {
Namhyung Kim280d1422014-06-13 01:23:51 +09004163 struct ftrace_graph_data *fgd = m->private;
4164
4165 if (fgd->table == ftrace_graph_funcs)
4166 seq_printf(m, "#### all functions enabled ####\n");
4167 else
4168 seq_printf(m, "#### no functions disabled ####\n");
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01004169 return 0;
4170 }
4171
Steven Rostedtb375a112009-09-17 00:05:58 -04004172 seq_printf(m, "%ps\n", (void *)*ptr);
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004173
4174 return 0;
4175}
4176
James Morris88e9d342009-09-22 16:43:43 -07004177static const struct seq_operations ftrace_graph_seq_ops = {
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004178 .start = g_start,
4179 .next = g_next,
4180 .stop = g_stop,
4181 .show = g_show,
4182};
4183
4184static int
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004185__ftrace_graph_open(struct inode *inode, struct file *file,
4186 struct ftrace_graph_data *fgd)
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004187{
4188 int ret = 0;
4189
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004190 mutex_lock(&graph_lock);
4191 if ((file->f_mode & FMODE_WRITE) &&
Steven Rostedt8650ae32009-07-22 23:29:30 -04004192 (file->f_flags & O_TRUNC)) {
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004193 *fgd->count = 0;
4194 memset(fgd->table, 0, fgd->size * sizeof(*fgd->table));
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004195 }
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004196 mutex_unlock(&graph_lock);
4197
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004198 if (file->f_mode & FMODE_READ) {
4199 ret = seq_open(file, fgd->seq_ops);
4200 if (!ret) {
4201 struct seq_file *m = file->private_data;
4202 m->private = fgd;
4203 }
4204 } else
4205 file->private_data = fgd;
Li Zefana4ec5e02009-09-18 14:06:28 +08004206
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004207 return ret;
4208}
4209
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004210static int
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004211ftrace_graph_open(struct inode *inode, struct file *file)
4212{
4213 struct ftrace_graph_data *fgd;
4214
4215 if (unlikely(ftrace_disabled))
4216 return -ENODEV;
4217
4218 fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
4219 if (fgd == NULL)
4220 return -ENOMEM;
4221
4222 fgd->table = ftrace_graph_funcs;
4223 fgd->size = FTRACE_GRAPH_MAX_FUNCS;
4224 fgd->count = &ftrace_graph_count;
4225 fgd->seq_ops = &ftrace_graph_seq_ops;
4226
4227 return __ftrace_graph_open(inode, file, fgd);
4228}
4229
4230static int
Namhyung Kim29ad23b2013-10-14 17:24:26 +09004231ftrace_graph_notrace_open(struct inode *inode, struct file *file)
4232{
4233 struct ftrace_graph_data *fgd;
4234
4235 if (unlikely(ftrace_disabled))
4236 return -ENODEV;
4237
4238 fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
4239 if (fgd == NULL)
4240 return -ENOMEM;
4241
4242 fgd->table = ftrace_graph_notrace_funcs;
4243 fgd->size = FTRACE_GRAPH_MAX_FUNCS;
4244 fgd->count = &ftrace_graph_notrace_count;
4245 fgd->seq_ops = &ftrace_graph_seq_ops;
4246
4247 return __ftrace_graph_open(inode, file, fgd);
4248}
4249
4250static int
Li Zefan87827112009-07-23 11:29:11 +08004251ftrace_graph_release(struct inode *inode, struct file *file)
4252{
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004253 if (file->f_mode & FMODE_READ) {
4254 struct seq_file *m = file->private_data;
4255
4256 kfree(m->private);
Li Zefan87827112009-07-23 11:29:11 +08004257 seq_release(inode, file);
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004258 } else {
4259 kfree(file->private_data);
4260 }
4261
Li Zefan87827112009-07-23 11:29:11 +08004262 return 0;
4263}
4264
4265static int
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004266ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer)
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004267{
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004268 struct dyn_ftrace *rec;
4269 struct ftrace_page *pg;
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01004270 int search_len;
Li Zefanc7c6b1f2010-02-10 15:43:04 +08004271 int fail = 1;
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01004272 int type, not;
4273 char *search;
4274 bool exists;
4275 int i;
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004276
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01004277 /* decode regex */
Frederic Weisbecker3f6fe062009-09-24 21:31:51 +02004278 type = filter_parse_regex(buffer, strlen(buffer), &search, &not);
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004279 if (!not && *idx >= size)
Li Zefanc7c6b1f2010-02-10 15:43:04 +08004280 return -EBUSY;
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01004281
4282 search_len = strlen(search);
4283
Steven Rostedt52baf112009-02-14 01:15:39 -05004284 mutex_lock(&ftrace_lock);
Steven Rostedt45a4a232011-04-21 23:16:46 -04004285
4286 if (unlikely(ftrace_disabled)) {
4287 mutex_unlock(&ftrace_lock);
4288 return -ENODEV;
4289 }
4290
Steven Rostedt265c8312009-02-13 12:43:56 -05004291 do_for_each_ftrace_rec(pg, rec) {
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004292
Steven Rostedtb9df92d2011-04-28 20:32:08 -04004293 if (ftrace_match_record(rec, NULL, search, search_len, type)) {
Li Zefanc7c6b1f2010-02-10 15:43:04 +08004294 /* if it is in the array */
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01004295 exists = false;
Li Zefanc7c6b1f2010-02-10 15:43:04 +08004296 for (i = 0; i < *idx; i++) {
Frederic Weisbeckerf9349a82009-02-19 21:13:12 +01004297 if (array[i] == rec->ip) {
4298 exists = true;
Steven Rostedt265c8312009-02-13 12:43:56 -05004299 break;
4300 }
Li Zefanc7c6b1f2010-02-10 15:43:04 +08004301 }
4302
4303 if (!not) {
4304 fail = 0;
4305 if (!exists) {
4306 array[(*idx)++] = rec->ip;
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004307 if (*idx >= size)
Li Zefanc7c6b1f2010-02-10 15:43:04 +08004308 goto out;
4309 }
4310 } else {
4311 if (exists) {
4312 array[i] = array[--(*idx)];
4313 array[*idx] = 0;
4314 fail = 0;
4315 }
4316 }
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004317 }
Steven Rostedt265c8312009-02-13 12:43:56 -05004318 } while_for_each_ftrace_rec();
Li Zefanc7c6b1f2010-02-10 15:43:04 +08004319out:
Steven Rostedt52baf112009-02-14 01:15:39 -05004320 mutex_unlock(&ftrace_lock);
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004321
Li Zefanc7c6b1f2010-02-10 15:43:04 +08004322 if (fail)
4323 return -EINVAL;
4324
Li Zefanc7c6b1f2010-02-10 15:43:04 +08004325 return 0;
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004326}
4327
4328static ssize_t
4329ftrace_graph_write(struct file *file, const char __user *ubuf,
4330 size_t cnt, loff_t *ppos)
4331{
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02004332 struct trace_parser parser;
Namhyung Kim6a101082013-10-14 17:24:25 +09004333 ssize_t read, ret = 0;
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004334 struct ftrace_graph_data *fgd = file->private_data;
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004335
Li Zefanc7c6b1f2010-02-10 15:43:04 +08004336 if (!cnt)
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004337 return 0;
4338
Namhyung Kim6a101082013-10-14 17:24:25 +09004339 if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX))
4340 return -ENOMEM;
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004341
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02004342 read = trace_get_user(&parser, ubuf, cnt, ppos);
4343
Li Zefan4ba79782009-09-22 13:52:20 +08004344 if (read >= 0 && trace_parser_loaded((&parser))) {
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02004345 parser.buffer[parser.idx] = 0;
4346
Namhyung Kim6a101082013-10-14 17:24:25 +09004347 mutex_lock(&graph_lock);
4348
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02004349 /* we allow only one expression at a time */
Namhyung Kimfaf982a2013-10-14 17:24:24 +09004350 ret = ftrace_set_func(fgd->table, fgd->count, fgd->size,
4351 parser.buffer);
Namhyung Kim6a101082013-10-14 17:24:25 +09004352
4353 mutex_unlock(&graph_lock);
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004354 }
4355
Namhyung Kim6a101082013-10-14 17:24:25 +09004356 if (!ret)
4357 ret = read;
Li Zefan1eb90f12009-09-22 13:52:57 +08004358
jolsa@redhat.com689fd8b2009-09-11 17:29:29 +02004359 trace_parser_put(&parser);
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004360
4361 return ret;
4362}
4363
4364static const struct file_operations ftrace_graph_fops = {
Li Zefan87827112009-07-23 11:29:11 +08004365 .open = ftrace_graph_open,
4366 .read = seq_read,
4367 .write = ftrace_graph_write,
Steven Rostedt (Red Hat)098c879e2013-12-21 17:39:40 -05004368 .llseek = tracing_lseek,
Li Zefan87827112009-07-23 11:29:11 +08004369 .release = ftrace_graph_release,
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004370};
Namhyung Kim29ad23b2013-10-14 17:24:26 +09004371
4372static const struct file_operations ftrace_graph_notrace_fops = {
4373 .open = ftrace_graph_notrace_open,
4374 .read = seq_read,
4375 .write = ftrace_graph_write,
Steven Rostedt (Red Hat)098c879e2013-12-21 17:39:40 -05004376 .llseek = tracing_lseek,
Namhyung Kim29ad23b2013-10-14 17:24:26 +09004377 .release = ftrace_graph_release,
4378};
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004379#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4380
Steven Rostedt (Red Hat)591dffd2014-01-10 16:17:45 -05004381void ftrace_create_filter_files(struct ftrace_ops *ops,
4382 struct dentry *parent)
4383{
4384
4385 trace_create_file("set_ftrace_filter", 0644, parent,
4386 ops, &ftrace_filter_fops);
4387
4388 trace_create_file("set_ftrace_notrace", 0644, parent,
4389 ops, &ftrace_notrace_fops);
4390}
4391
4392/*
4393 * The name "destroy_filter_files" is really a misnomer. Although
4394 * in the future, it may actualy delete the files, but this is
4395 * really intended to make sure the ops passed in are disabled
4396 * and that when this function returns, the caller is free to
4397 * free the ops.
4398 *
4399 * The "destroy" name is only to match the "create" name that this
4400 * should be paired with.
4401 */
4402void ftrace_destroy_filter_files(struct ftrace_ops *ops)
4403{
4404 mutex_lock(&ftrace_lock);
4405 if (ops->flags & FTRACE_OPS_FL_ENABLED)
4406 ftrace_shutdown(ops, 0);
4407 ops->flags |= FTRACE_OPS_FL_DELETED;
4408 mutex_unlock(&ftrace_lock);
4409}
4410
Steven Rostedtdf4fc312008-11-26 00:16:23 -05004411static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
Steven Rostedt5072c592008-05-12 21:20:43 +02004412{
Steven Rostedt5072c592008-05-12 21:20:43 +02004413
Frederic Weisbecker5452af62009-03-27 00:25:38 +01004414 trace_create_file("available_filter_functions", 0444,
4415 d_tracer, NULL, &ftrace_avail_fops);
Steven Rostedt5072c592008-05-12 21:20:43 +02004416
Steven Rostedt647bcd02011-05-03 14:39:21 -04004417 trace_create_file("enabled_functions", 0444,
4418 d_tracer, NULL, &ftrace_enabled_fops);
4419
Steven Rostedt (Red Hat)591dffd2014-01-10 16:17:45 -05004420 ftrace_create_filter_files(&global_ops, d_tracer);
Steven Rostedtad90c0e2008-05-27 20:48:37 -04004421
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004422#ifdef CONFIG_FUNCTION_GRAPH_TRACER
Frederic Weisbecker5452af62009-03-27 00:25:38 +01004423 trace_create_file("set_graph_function", 0444, d_tracer,
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004424 NULL,
4425 &ftrace_graph_fops);
Namhyung Kim29ad23b2013-10-14 17:24:26 +09004426 trace_create_file("set_graph_notrace", 0444, d_tracer,
4427 NULL,
4428 &ftrace_graph_notrace_fops);
Steven Rostedtea4e2bc2008-12-03 15:36:57 -05004429#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4430
Steven Rostedt5072c592008-05-12 21:20:43 +02004431 return 0;
4432}
4433
Steven Rostedt9fd49322012-04-24 22:32:06 -04004434static int ftrace_cmp_ips(const void *a, const void *b)
Steven Rostedt68950612011-12-16 17:06:45 -05004435{
Steven Rostedt9fd49322012-04-24 22:32:06 -04004436 const unsigned long *ipa = a;
4437 const unsigned long *ipb = b;
Steven Rostedt68950612011-12-16 17:06:45 -05004438
Steven Rostedt9fd49322012-04-24 22:32:06 -04004439 if (*ipa > *ipb)
4440 return 1;
4441 if (*ipa < *ipb)
4442 return -1;
4443 return 0;
4444}
4445
4446static void ftrace_swap_ips(void *a, void *b, int size)
4447{
4448 unsigned long *ipa = a;
4449 unsigned long *ipb = b;
4450 unsigned long t;
4451
4452 t = *ipa;
4453 *ipa = *ipb;
4454 *ipb = t;
Steven Rostedt68950612011-12-16 17:06:45 -05004455}
4456
Jiri Olsa5cb084b2009-10-13 16:33:53 -04004457static int ftrace_process_locs(struct module *mod,
Steven Rostedt31e88902008-11-14 16:21:19 -08004458 unsigned long *start,
Steven Rostedt68bf21a2008-08-14 15:45:08 -04004459 unsigned long *end)
4460{
Steven Rostedt706c81f2012-04-24 23:45:26 -04004461 struct ftrace_page *start_pg;
Steven Rostedta7900872011-12-16 16:23:44 -05004462 struct ftrace_page *pg;
Steven Rostedt706c81f2012-04-24 23:45:26 -04004463 struct dyn_ftrace *rec;
Steven Rostedta7900872011-12-16 16:23:44 -05004464 unsigned long count;
Steven Rostedt68bf21a2008-08-14 15:45:08 -04004465 unsigned long *p;
4466 unsigned long addr;
Steven Rostedt4376cac2011-06-24 23:28:13 -04004467 unsigned long flags = 0; /* Shut up gcc */
Steven Rostedta7900872011-12-16 16:23:44 -05004468 int ret = -ENOMEM;
4469
4470 count = end - start;
4471
4472 if (!count)
4473 return 0;
4474
Steven Rostedt9fd49322012-04-24 22:32:06 -04004475 sort(start, count, sizeof(*start),
4476 ftrace_cmp_ips, ftrace_swap_ips);
4477
Steven Rostedt706c81f2012-04-24 23:45:26 -04004478 start_pg = ftrace_allocate_pages(count);
4479 if (!start_pg)
Steven Rostedta7900872011-12-16 16:23:44 -05004480 return -ENOMEM;
Steven Rostedt68bf21a2008-08-14 15:45:08 -04004481
Steven Rostedte6ea44e2009-02-14 01:42:44 -05004482 mutex_lock(&ftrace_lock);
Steven Rostedta7900872011-12-16 16:23:44 -05004483
Steven Rostedt320823092011-12-16 14:42:37 -05004484 /*
4485 * Core and each module needs their own pages, as
4486 * modules will free them when they are removed.
4487 * Force a new page to be allocated for modules.
4488 */
Steven Rostedta7900872011-12-16 16:23:44 -05004489 if (!mod) {
4490 WARN_ON(ftrace_pages || ftrace_pages_start);
4491 /* First initialization */
Steven Rostedt706c81f2012-04-24 23:45:26 -04004492 ftrace_pages = ftrace_pages_start = start_pg;
Steven Rostedta7900872011-12-16 16:23:44 -05004493 } else {
Steven Rostedt320823092011-12-16 14:42:37 -05004494 if (!ftrace_pages)
Steven Rostedta7900872011-12-16 16:23:44 -05004495 goto out;
Steven Rostedt320823092011-12-16 14:42:37 -05004496
Steven Rostedta7900872011-12-16 16:23:44 -05004497 if (WARN_ON(ftrace_pages->next)) {
4498 /* Hmm, we have free pages? */
4499 while (ftrace_pages->next)
4500 ftrace_pages = ftrace_pages->next;
Steven Rostedt320823092011-12-16 14:42:37 -05004501 }
Steven Rostedta7900872011-12-16 16:23:44 -05004502
Steven Rostedt706c81f2012-04-24 23:45:26 -04004503 ftrace_pages->next = start_pg;
Steven Rostedt320823092011-12-16 14:42:37 -05004504 }
4505
Steven Rostedt68bf21a2008-08-14 15:45:08 -04004506 p = start;
Steven Rostedt706c81f2012-04-24 23:45:26 -04004507 pg = start_pg;
Steven Rostedt68bf21a2008-08-14 15:45:08 -04004508 while (p < end) {
4509 addr = ftrace_call_adjust(*p++);
Steven Rostedt20e52272008-11-14 16:21:19 -08004510 /*
4511 * Some architecture linkers will pad between
4512 * the different mcount_loc sections of different
4513 * object files to satisfy alignments.
4514 * Skip any NULL pointers.
4515 */
4516 if (!addr)
4517 continue;
Steven Rostedt706c81f2012-04-24 23:45:26 -04004518
4519 if (pg->index == pg->size) {
4520 /* We should have allocated enough */
4521 if (WARN_ON(!pg->next))
4522 break;
4523 pg = pg->next;
4524 }
4525
4526 rec = &pg->records[pg->index++];
4527 rec->ip = addr;
Steven Rostedt68bf21a2008-08-14 15:45:08 -04004528 }
4529
Steven Rostedt706c81f2012-04-24 23:45:26 -04004530 /* We should have used all pages */
4531 WARN_ON(pg->next);
4532
4533 /* Assign the last page to ftrace_pages */
4534 ftrace_pages = pg;
4535
Steven Rostedta4f18ed2011-06-07 09:26:46 -04004536 /*
Steven Rostedt4376cac2011-06-24 23:28:13 -04004537 * We only need to disable interrupts on start up
4538 * because we are modifying code that an interrupt
4539 * may execute, and the modification is not atomic.
4540 * But for modules, nothing runs the code we modify
4541 * until we are finished with it, and there's no
4542 * reason to cause large interrupt latencies while we do it.
Steven Rostedta4f18ed2011-06-07 09:26:46 -04004543 */
Steven Rostedt4376cac2011-06-24 23:28:13 -04004544 if (!mod)
4545 local_irq_save(flags);
Jiri Slaby1dc43cf2014-02-24 19:59:56 +01004546 ftrace_update_code(mod, start_pg);
Steven Rostedt4376cac2011-06-24 23:28:13 -04004547 if (!mod)
4548 local_irq_restore(flags);
Steven Rostedta7900872011-12-16 16:23:44 -05004549 ret = 0;
4550 out:
Steven Rostedte6ea44e2009-02-14 01:42:44 -05004551 mutex_unlock(&ftrace_lock);
Steven Rostedt68bf21a2008-08-14 15:45:08 -04004552
Steven Rostedta7900872011-12-16 16:23:44 -05004553 return ret;
Steven Rostedt68bf21a2008-08-14 15:45:08 -04004554}
4555
Steven Rostedt93eb6772009-04-15 13:24:06 -04004556#ifdef CONFIG_MODULES
Steven Rostedt320823092011-12-16 14:42:37 -05004557
4558#define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
4559
jolsa@redhat.come7247a12009-10-07 19:00:35 +02004560void ftrace_release_mod(struct module *mod)
Steven Rostedt93eb6772009-04-15 13:24:06 -04004561{
4562 struct dyn_ftrace *rec;
Steven Rostedt320823092011-12-16 14:42:37 -05004563 struct ftrace_page **last_pg;
Steven Rostedt93eb6772009-04-15 13:24:06 -04004564 struct ftrace_page *pg;
Steven Rostedta7900872011-12-16 16:23:44 -05004565 int order;
Steven Rostedt93eb6772009-04-15 13:24:06 -04004566
Steven Rostedt93eb6772009-04-15 13:24:06 -04004567 mutex_lock(&ftrace_lock);
Steven Rostedt45a4a232011-04-21 23:16:46 -04004568
4569 if (ftrace_disabled)
4570 goto out_unlock;
4571
Steven Rostedt320823092011-12-16 14:42:37 -05004572 /*
4573 * Each module has its own ftrace_pages, remove
4574 * them from the list.
4575 */
4576 last_pg = &ftrace_pages_start;
4577 for (pg = ftrace_pages_start; pg; pg = *last_pg) {
4578 rec = &pg->records[0];
jolsa@redhat.come7247a12009-10-07 19:00:35 +02004579 if (within_module_core(rec->ip, mod)) {
Steven Rostedt93eb6772009-04-15 13:24:06 -04004580 /*
Steven Rostedt320823092011-12-16 14:42:37 -05004581 * As core pages are first, the first
4582 * page should never be a module page.
Steven Rostedt93eb6772009-04-15 13:24:06 -04004583 */
Steven Rostedt320823092011-12-16 14:42:37 -05004584 if (WARN_ON(pg == ftrace_pages_start))
4585 goto out_unlock;
4586
4587 /* Check if we are deleting the last page */
4588 if (pg == ftrace_pages)
4589 ftrace_pages = next_to_ftrace_page(last_pg);
4590
4591 *last_pg = pg->next;
Steven Rostedta7900872011-12-16 16:23:44 -05004592 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
4593 free_pages((unsigned long)pg->records, order);
4594 kfree(pg);
Steven Rostedt320823092011-12-16 14:42:37 -05004595 } else
4596 last_pg = &pg->next;
4597 }
Steven Rostedt45a4a232011-04-21 23:16:46 -04004598 out_unlock:
Steven Rostedt93eb6772009-04-15 13:24:06 -04004599 mutex_unlock(&ftrace_lock);
4600}
4601
4602static void ftrace_init_module(struct module *mod,
4603 unsigned long *start, unsigned long *end)
Steven Rostedt90d595f2008-08-14 15:45:09 -04004604{
Steven Rostedt00fd61a2008-08-15 21:40:04 -04004605 if (ftrace_disabled || start == end)
Steven Rostedtfed19392008-08-14 22:47:19 -04004606 return;
Jiri Olsa5cb084b2009-10-13 16:33:53 -04004607 ftrace_process_locs(mod, start, end);
Steven Rostedt90d595f2008-08-14 15:45:09 -04004608}
4609
Steven Rostedt (Red Hat)a949ae52014-04-24 10:40:12 -04004610void ftrace_module_init(struct module *mod)
Steven Rostedt93eb6772009-04-15 13:24:06 -04004611{
Steven Rostedt (Red Hat)a949ae52014-04-24 10:40:12 -04004612 ftrace_init_module(mod, mod->ftrace_callsites,
4613 mod->ftrace_callsites +
4614 mod->num_ftrace_callsites);
Steven Rostedt (Red Hat)8c189ea2013-02-13 15:18:38 -05004615}
4616
4617static int ftrace_module_notify_exit(struct notifier_block *self,
4618 unsigned long val, void *data)
4619{
4620 struct module *mod = data;
4621
4622 if (val == MODULE_STATE_GOING)
jolsa@redhat.come7247a12009-10-07 19:00:35 +02004623 ftrace_release_mod(mod);
Steven Rostedt93eb6772009-04-15 13:24:06 -04004624
4625 return 0;
4626}
4627#else
Steven Rostedt (Red Hat)8c189ea2013-02-13 15:18:38 -05004628static int ftrace_module_notify_exit(struct notifier_block *self,
4629 unsigned long val, void *data)
Steven Rostedt93eb6772009-04-15 13:24:06 -04004630{
4631 return 0;
4632}
4633#endif /* CONFIG_MODULES */
4634
Steven Rostedt (Red Hat)8c189ea2013-02-13 15:18:38 -05004635struct notifier_block ftrace_module_exit_nb = {
4636 .notifier_call = ftrace_module_notify_exit,
4637 .priority = INT_MIN, /* Run after anything that can remove kprobes */
4638};
4639
Steven Rostedt68bf21a2008-08-14 15:45:08 -04004640void __init ftrace_init(void)
4641{
Jiri Slaby1dc43cf2014-02-24 19:59:56 +01004642 extern unsigned long __start_mcount_loc[];
4643 extern unsigned long __stop_mcount_loc[];
Jiri Slaby3a36cb12014-02-24 19:59:59 +01004644 unsigned long count, flags;
Steven Rostedt68bf21a2008-08-14 15:45:08 -04004645 int ret;
4646
Steven Rostedt68bf21a2008-08-14 15:45:08 -04004647 local_irq_save(flags);
Jiri Slaby3a36cb12014-02-24 19:59:59 +01004648 ret = ftrace_dyn_arch_init();
Steven Rostedt68bf21a2008-08-14 15:45:08 -04004649 local_irq_restore(flags);
Jiri Slabyaf64a7c2014-02-24 19:59:58 +01004650 if (ret)
Steven Rostedt68bf21a2008-08-14 15:45:08 -04004651 goto failed;
4652
4653 count = __stop_mcount_loc - __start_mcount_loc;
Jiri Slabyc867ccd2014-02-24 19:59:57 +01004654 if (!count) {
4655 pr_info("ftrace: No functions to be traced?\n");
Steven Rostedt68bf21a2008-08-14 15:45:08 -04004656 goto failed;
Jiri Slabyc867ccd2014-02-24 19:59:57 +01004657 }
4658
4659 pr_info("ftrace: allocating %ld entries in %ld pages\n",
4660 count, count / ENTRIES_PER_PAGE + 1);
Steven Rostedt68bf21a2008-08-14 15:45:08 -04004661
4662 last_ftrace_enabled = ftrace_enabled = 1;
4663
Jiri Olsa5cb084b2009-10-13 16:33:53 -04004664 ret = ftrace_process_locs(NULL,
Steven Rostedt31e88902008-11-14 16:21:19 -08004665 __start_mcount_loc,
Steven Rostedt68bf21a2008-08-14 15:45:08 -04004666 __stop_mcount_loc);
4667
Steven Rostedt (Red Hat)8c189ea2013-02-13 15:18:38 -05004668 ret = register_module_notifier(&ftrace_module_exit_nb);
4669 if (ret)
4670 pr_warning("Failed to register trace ftrace module exit notifier\n");
Steven Rostedt93eb6772009-04-15 13:24:06 -04004671
Steven Rostedt2af15d62009-05-28 13:37:24 -04004672 set_ftrace_early_filters();
4673
Steven Rostedt68bf21a2008-08-14 15:45:08 -04004674 return;
4675 failed:
4676 ftrace_disabled = 1;
4677}
Steven Rostedt68bf21a2008-08-14 15:45:08 -04004678
Steven Rostedt3d083392008-05-12 21:20:42 +02004679#else
Frederic Weisbecker0b6e4d562008-10-28 20:17:38 +01004680
Steven Rostedt2b499382011-05-03 22:49:52 -04004681static struct ftrace_ops global_ops = {
Steven Rostedtbd69c302011-05-03 21:55:54 -04004682 .func = ftrace_stub,
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +09004683 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
Steven Rostedtbd69c302011-05-03 21:55:54 -04004684};
4685
Frederic Weisbecker0b6e4d562008-10-28 20:17:38 +01004686static int __init ftrace_nodyn_init(void)
4687{
4688 ftrace_enabled = 1;
4689 return 0;
4690}
Steven Rostedt6f415672012-10-05 12:13:07 -04004691core_initcall(ftrace_nodyn_init);
Frederic Weisbecker0b6e4d562008-10-28 20:17:38 +01004692
Steven Rostedtdf4fc312008-11-26 00:16:23 -05004693static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }
4694static inline void ftrace_startup_enable(int command) { }
Steven Rostedt (Red Hat)e1effa02014-08-05 17:19:38 -04004695static inline void ftrace_startup_all(int command) { }
Steven Rostedt5a45cfe2008-11-26 00:16:24 -05004696/* Keep as macros so we do not need to define the commands */
Steven Rostedt (Red Hat)8a56d772013-11-25 20:59:46 -05004697# define ftrace_startup(ops, command) \
4698 ({ \
4699 int ___ret = __register_ftrace_function(ops); \
4700 if (!___ret) \
4701 (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
4702 ___ret; \
Steven Rostedt3b6cfdb2011-05-23 15:33:49 -04004703 })
Steven Rostedt (Red Hat)1fcc1552014-02-19 15:12:18 -05004704# define ftrace_shutdown(ops, command) \
4705 ({ \
4706 int ___ret = __unregister_ftrace_function(ops); \
4707 if (!___ret) \
4708 (ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \
4709 ___ret; \
4710 })
Steven Rostedt (Red Hat)8a56d772013-11-25 20:59:46 -05004711
Ingo Molnarc7aafc52008-05-12 21:20:45 +02004712# define ftrace_startup_sysctl() do { } while (0)
4713# define ftrace_shutdown_sysctl() do { } while (0)
Steven Rostedtb8489142011-05-04 09:27:52 -04004714
4715static inline int
Steven Rostedt (Red Hat)195a8af2013-07-23 22:06:15 -04004716ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
Steven Rostedtb8489142011-05-04 09:27:52 -04004717{
4718 return 1;
4719}
4720
Steven Rostedt3d083392008-05-12 21:20:42 +02004721#endif /* CONFIG_DYNAMIC_FTRACE */
4722
Steven Rostedt (Red Hat)4104d322014-01-10 17:01:58 -05004723__init void ftrace_init_global_array_ops(struct trace_array *tr)
4724{
4725 tr->ops = &global_ops;
4726 tr->ops->private = tr;
4727}
4728
4729void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func)
4730{
4731 /* If we filter on pids, update to use the pid function */
4732 if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
4733 if (WARN_ON(tr->ops->func != ftrace_stub))
4734 printk("ftrace ops had %pS for function\n",
4735 tr->ops->func);
4736 /* Only the top level instance does pid tracing */
4737 if (!list_empty(&ftrace_pids)) {
4738 set_ftrace_pid_function(func);
4739 func = ftrace_pid_func;
4740 }
4741 }
4742 tr->ops->func = func;
4743 tr->ops->private = tr;
4744}
4745
4746void ftrace_reset_array_ops(struct trace_array *tr)
4747{
4748 tr->ops->func = ftrace_stub;
4749}
4750
Steven Rostedtb8489142011-05-04 09:27:52 -04004751static void
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -04004752ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip,
Steven Rostedta1e2e312011-08-09 12:50:46 -04004753 struct ftrace_ops *op, struct pt_regs *regs)
Jiri Olsae2484912012-02-15 15:51:48 +01004754{
Jiri Olsae2484912012-02-15 15:51:48 +01004755 if (unlikely(trace_recursion_test(TRACE_CONTROL_BIT)))
4756 return;
4757
4758 /*
4759 * Some of the ops may be dynamically allocated,
4760 * they must be freed after a synchronize_sched().
4761 */
4762 preempt_disable_notrace();
4763 trace_recursion_set(TRACE_CONTROL_BIT);
Steven Rostedt (Red Hat)b5aa3a42013-11-04 18:34:44 -05004764
4765 /*
4766 * Control funcs (perf) uses RCU. Only trace if
4767 * RCU is currently active.
4768 */
4769 if (!rcu_is_watching())
4770 goto out;
4771
Steven Rostedt0a016402012-11-02 17:03:03 -04004772 do_for_each_ftrace_op(op, ftrace_control_list) {
Steven Rostedt (Red Hat)395b97a2013-03-27 09:31:28 -04004773 if (!(op->flags & FTRACE_OPS_FL_STUB) &&
4774 !ftrace_function_local_disabled(op) &&
Steven Rostedt (Red Hat)195a8af2013-07-23 22:06:15 -04004775 ftrace_ops_test(op, ip, regs))
Steven Rostedta1e2e312011-08-09 12:50:46 -04004776 op->func(ip, parent_ip, op, regs);
Steven Rostedt0a016402012-11-02 17:03:03 -04004777 } while_for_each_ftrace_op(op);
Steven Rostedt (Red Hat)b5aa3a42013-11-04 18:34:44 -05004778 out:
Jiri Olsae2484912012-02-15 15:51:48 +01004779 trace_recursion_clear(TRACE_CONTROL_BIT);
4780 preempt_enable_notrace();
4781}
4782
4783static struct ftrace_ops control_ops = {
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +09004784 .func = ftrace_ops_control_func,
4785 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
Steven Rostedt (Red Hat)33b7f992014-08-15 17:23:02 -04004786 INIT_OPS_HASH(control_ops)
Jiri Olsae2484912012-02-15 15:51:48 +01004787};
4788
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -04004789static inline void
4790__ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
Steven Rostedta1e2e312011-08-09 12:50:46 -04004791 struct ftrace_ops *ignored, struct pt_regs *regs)
Steven Rostedtb8489142011-05-04 09:27:52 -04004792{
Steven Rostedtcdbe61b2011-05-05 21:14:55 -04004793 struct ftrace_ops *op;
Steven Rostedtedc15ca2012-11-02 17:47:21 -04004794 int bit;
Steven Rostedtb8489142011-05-04 09:27:52 -04004795
Steven Rostedtedc15ca2012-11-02 17:47:21 -04004796 bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
4797 if (bit < 0)
4798 return;
Steven Rostedtc29f1222012-11-02 17:17:59 -04004799
Steven Rostedtcdbe61b2011-05-05 21:14:55 -04004800 /*
4801 * Some of the ops may be dynamically allocated,
4802 * they must be freed after a synchronize_sched().
4803 */
4804 preempt_disable_notrace();
Steven Rostedt0a016402012-11-02 17:03:03 -04004805 do_for_each_ftrace_op(op, ftrace_ops_list) {
Steven Rostedt (Red Hat)4104d322014-01-10 17:01:58 -05004806 if (ftrace_ops_test(op, ip, regs)) {
Steven Rostedt (Red Hat)1d48d592014-06-25 11:54:03 -04004807 if (FTRACE_WARN_ON(!op->func)) {
4808 pr_warn("op=%p %pS\n", op, op);
Steven Rostedt (Red Hat)4104d322014-01-10 17:01:58 -05004809 goto out;
4810 }
Steven Rostedta1e2e312011-08-09 12:50:46 -04004811 op->func(ip, parent_ip, op, regs);
Steven Rostedt (Red Hat)4104d322014-01-10 17:01:58 -05004812 }
Steven Rostedt0a016402012-11-02 17:03:03 -04004813 } while_for_each_ftrace_op(op);
Steven Rostedt (Red Hat)4104d322014-01-10 17:01:58 -05004814out:
Steven Rostedtcdbe61b2011-05-05 21:14:55 -04004815 preempt_enable_notrace();
Steven Rostedtedc15ca2012-11-02 17:47:21 -04004816 trace_clear_recursion(bit);
Steven Rostedtb8489142011-05-04 09:27:52 -04004817}
4818
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -04004819/*
4820 * Some archs only support passing ip and parent_ip. Even though
4821 * the list function ignores the op parameter, we do not want any
4822 * C side effects, where a function is called without the caller
4823 * sending a third parameter.
Steven Rostedta1e2e312011-08-09 12:50:46 -04004824 * Archs are to support both the regs and ftrace_ops at the same time.
4825 * If they support ftrace_ops, it is assumed they support regs.
4826 * If call backs want to use regs, they must either check for regs
Masami Hiramatsu06aeaae2012-09-28 17:15:17 +09004827 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
4828 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
Steven Rostedta1e2e312011-08-09 12:50:46 -04004829 * An architecture can pass partial regs with ftrace_ops and still
4830 * set the ARCH_SUPPORT_FTARCE_OPS.
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -04004831 */
4832#if ARCH_SUPPORTS_FTRACE_OPS
4833static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
Steven Rostedta1e2e312011-08-09 12:50:46 -04004834 struct ftrace_ops *op, struct pt_regs *regs)
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -04004835{
Steven Rostedta1e2e312011-08-09 12:50:46 -04004836 __ftrace_ops_list_func(ip, parent_ip, NULL, regs);
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -04004837}
4838#else
4839static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
4840{
Steven Rostedta1e2e312011-08-09 12:50:46 -04004841 __ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
Steven Rostedt2f5f6ad2011-08-08 16:57:47 -04004842}
4843#endif
4844
Steven Rostedt (Red Hat)f1ff6342014-07-22 20:16:57 -04004845/*
4846 * If there's only one function registered but it does not support
4847 * recursion, this function will be called by the mcount trampoline.
4848 * This function will handle recursion protection.
4849 */
4850static void ftrace_ops_recurs_func(unsigned long ip, unsigned long parent_ip,
4851 struct ftrace_ops *op, struct pt_regs *regs)
4852{
4853 int bit;
4854
4855 bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
4856 if (bit < 0)
4857 return;
4858
4859 op->func(ip, parent_ip, op, regs);
4860
4861 trace_clear_recursion(bit);
4862}
4863
Steven Rostedt (Red Hat)87354052014-07-22 20:41:42 -04004864/**
4865 * ftrace_ops_get_func - get the function a trampoline should call
4866 * @ops: the ops to get the function for
4867 *
4868 * Normally the mcount trampoline will call the ops->func, but there
4869 * are times that it should not. For example, if the ops does not
4870 * have its own recursion protection, then it should call the
4871 * ftrace_ops_recurs_func() instead.
4872 *
4873 * Returns the function that the trampoline should call for @ops.
4874 */
4875ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops)
4876{
4877 /*
4878 * If this is a dynamic ops or we force list func,
4879 * then it needs to call the list anyway.
4880 */
4881 if (ops->flags & FTRACE_OPS_FL_DYNAMIC || FTRACE_FORCE_LIST_FUNC)
4882 return ftrace_ops_list_func;
4883
4884 /*
4885 * If the func handles its own recursion, call it directly.
4886 * Otherwise call the recursion protected function that
4887 * will call the ftrace ops function.
4888 */
4889 if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE))
4890 return ftrace_ops_recurs_func;
4891
4892 return ops->func;
4893}
4894
Steven Rostedte32d8952008-12-04 00:26:41 -05004895static void clear_ftrace_swapper(void)
4896{
4897 struct task_struct *p;
4898 int cpu;
4899
4900 get_online_cpus();
4901 for_each_online_cpu(cpu) {
4902 p = idle_task(cpu);
4903 clear_tsk_trace_trace(p);
4904 }
4905 put_online_cpus();
4906}
4907
4908static void set_ftrace_swapper(void)
4909{
4910 struct task_struct *p;
4911 int cpu;
4912
4913 get_online_cpus();
4914 for_each_online_cpu(cpu) {
4915 p = idle_task(cpu);
4916 set_tsk_trace_trace(p);
4917 }
4918 put_online_cpus();
4919}
4920
4921static void clear_ftrace_pid(struct pid *pid)
Steven Rostedt978f3a42008-12-04 00:26:40 -05004922{
4923 struct task_struct *p;
4924
Oleg Nesterov229c4ef2009-02-03 20:39:04 +01004925 rcu_read_lock();
Steven Rostedte32d8952008-12-04 00:26:41 -05004926 do_each_pid_task(pid, PIDTYPE_PID, p) {
Steven Rostedt978f3a42008-12-04 00:26:40 -05004927 clear_tsk_trace_trace(p);
Steven Rostedte32d8952008-12-04 00:26:41 -05004928 } while_each_pid_task(pid, PIDTYPE_PID, p);
Oleg Nesterov229c4ef2009-02-03 20:39:04 +01004929 rcu_read_unlock();
4930
Steven Rostedte32d8952008-12-04 00:26:41 -05004931 put_pid(pid);
Steven Rostedt978f3a42008-12-04 00:26:40 -05004932}
4933
Steven Rostedte32d8952008-12-04 00:26:41 -05004934static void set_ftrace_pid(struct pid *pid)
Steven Rostedt978f3a42008-12-04 00:26:40 -05004935{
4936 struct task_struct *p;
4937
Oleg Nesterov229c4ef2009-02-03 20:39:04 +01004938 rcu_read_lock();
Steven Rostedt978f3a42008-12-04 00:26:40 -05004939 do_each_pid_task(pid, PIDTYPE_PID, p) {
4940 set_tsk_trace_trace(p);
4941 } while_each_pid_task(pid, PIDTYPE_PID, p);
Oleg Nesterov229c4ef2009-02-03 20:39:04 +01004942 rcu_read_unlock();
Steven Rostedt978f3a42008-12-04 00:26:40 -05004943}
4944
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04004945static void clear_ftrace_pid_task(struct pid *pid)
Steven Rostedte32d8952008-12-04 00:26:41 -05004946{
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04004947 if (pid == ftrace_swapper_pid)
Steven Rostedte32d8952008-12-04 00:26:41 -05004948 clear_ftrace_swapper();
4949 else
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04004950 clear_ftrace_pid(pid);
Steven Rostedte32d8952008-12-04 00:26:41 -05004951}
4952
4953static void set_ftrace_pid_task(struct pid *pid)
4954{
4955 if (pid == ftrace_swapper_pid)
4956 set_ftrace_swapper();
4957 else
4958 set_ftrace_pid(pid);
4959}
4960
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04004961static int ftrace_pid_add(int p)
4962{
4963 struct pid *pid;
4964 struct ftrace_pid *fpid;
4965 int ret = -EINVAL;
4966
4967 mutex_lock(&ftrace_lock);
4968
4969 if (!p)
4970 pid = ftrace_swapper_pid;
4971 else
4972 pid = find_get_pid(p);
4973
4974 if (!pid)
4975 goto out;
4976
4977 ret = 0;
4978
4979 list_for_each_entry(fpid, &ftrace_pids, list)
4980 if (fpid->pid == pid)
4981 goto out_put;
4982
4983 ret = -ENOMEM;
4984
4985 fpid = kmalloc(sizeof(*fpid), GFP_KERNEL);
4986 if (!fpid)
4987 goto out_put;
4988
4989 list_add(&fpid->list, &ftrace_pids);
4990 fpid->pid = pid;
4991
4992 set_ftrace_pid_task(pid);
4993
4994 ftrace_update_pid_func();
Steven Rostedt (Red Hat)e1effa02014-08-05 17:19:38 -04004995
4996 ftrace_startup_all(0);
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04004997
4998 mutex_unlock(&ftrace_lock);
4999 return 0;
5000
5001out_put:
5002 if (pid != ftrace_swapper_pid)
5003 put_pid(pid);
5004
5005out:
5006 mutex_unlock(&ftrace_lock);
5007 return ret;
5008}
5009
5010static void ftrace_pid_reset(void)
5011{
5012 struct ftrace_pid *fpid, *safe;
5013
5014 mutex_lock(&ftrace_lock);
5015 list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) {
5016 struct pid *pid = fpid->pid;
5017
5018 clear_ftrace_pid_task(pid);
5019
5020 list_del(&fpid->list);
5021 kfree(fpid);
5022 }
5023
5024 ftrace_update_pid_func();
Steven Rostedt (Red Hat)e1effa02014-08-05 17:19:38 -04005025 ftrace_startup_all(0);
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005026
5027 mutex_unlock(&ftrace_lock);
5028}
5029
5030static void *fpid_start(struct seq_file *m, loff_t *pos)
5031{
5032 mutex_lock(&ftrace_lock);
5033
5034 if (list_empty(&ftrace_pids) && (!*pos))
5035 return (void *) 1;
5036
5037 return seq_list_start(&ftrace_pids, *pos);
5038}
5039
5040static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
5041{
5042 if (v == (void *)1)
5043 return NULL;
5044
5045 return seq_list_next(v, &ftrace_pids, pos);
5046}
5047
5048static void fpid_stop(struct seq_file *m, void *p)
5049{
5050 mutex_unlock(&ftrace_lock);
5051}
5052
5053static int fpid_show(struct seq_file *m, void *v)
5054{
5055 const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list);
5056
5057 if (v == (void *)1) {
5058 seq_printf(m, "no pid\n");
5059 return 0;
5060 }
5061
5062 if (fpid->pid == ftrace_swapper_pid)
5063 seq_printf(m, "swapper tasks\n");
5064 else
5065 seq_printf(m, "%u\n", pid_vnr(fpid->pid));
5066
5067 return 0;
5068}
5069
5070static const struct seq_operations ftrace_pid_sops = {
5071 .start = fpid_start,
5072 .next = fpid_next,
5073 .stop = fpid_stop,
5074 .show = fpid_show,
5075};
5076
5077static int
5078ftrace_pid_open(struct inode *inode, struct file *file)
5079{
5080 int ret = 0;
5081
5082 if ((file->f_mode & FMODE_WRITE) &&
5083 (file->f_flags & O_TRUNC))
5084 ftrace_pid_reset();
5085
5086 if (file->f_mode & FMODE_READ)
5087 ret = seq_open(file, &ftrace_pid_sops);
5088
5089 return ret;
5090}
5091
Steven Rostedtdf4fc312008-11-26 00:16:23 -05005092static ssize_t
5093ftrace_pid_write(struct file *filp, const char __user *ubuf,
5094 size_t cnt, loff_t *ppos)
5095{
Ingo Molnar457dc922009-11-23 11:03:28 +01005096 char buf[64], *tmp;
Steven Rostedtdf4fc312008-11-26 00:16:23 -05005097 long val;
5098 int ret;
5099
5100 if (cnt >= sizeof(buf))
5101 return -EINVAL;
5102
5103 if (copy_from_user(&buf, ubuf, cnt))
5104 return -EFAULT;
5105
5106 buf[cnt] = 0;
5107
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005108 /*
5109 * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid"
5110 * to clean the filter quietly.
5111 */
Ingo Molnar457dc922009-11-23 11:03:28 +01005112 tmp = strstrip(buf);
5113 if (strlen(tmp) == 0)
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005114 return 1;
5115
Daniel Walterbcd83ea2012-09-26 22:08:38 +02005116 ret = kstrtol(tmp, 10, &val);
Steven Rostedtdf4fc312008-11-26 00:16:23 -05005117 if (ret < 0)
5118 return ret;
5119
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005120 ret = ftrace_pid_add(val);
Steven Rostedt978f3a42008-12-04 00:26:40 -05005121
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005122 return ret ? ret : cnt;
5123}
Steven Rostedtdf4fc312008-11-26 00:16:23 -05005124
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005125static int
5126ftrace_pid_release(struct inode *inode, struct file *file)
5127{
5128 if (file->f_mode & FMODE_READ)
5129 seq_release(inode, file);
Steven Rostedtdf4fc312008-11-26 00:16:23 -05005130
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005131 return 0;
Steven Rostedtdf4fc312008-11-26 00:16:23 -05005132}
5133
Steven Rostedt5e2336a2009-03-05 21:44:55 -05005134static const struct file_operations ftrace_pid_fops = {
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005135 .open = ftrace_pid_open,
5136 .write = ftrace_pid_write,
5137 .read = seq_read,
Steven Rostedt (Red Hat)098c879e2013-12-21 17:39:40 -05005138 .llseek = tracing_lseek,
jolsa@redhat.com756d17e2009-10-13 16:33:52 -04005139 .release = ftrace_pid_release,
Steven Rostedtdf4fc312008-11-26 00:16:23 -05005140};
5141
5142static __init int ftrace_init_debugfs(void)
5143{
5144 struct dentry *d_tracer;
Steven Rostedtdf4fc312008-11-26 00:16:23 -05005145
5146 d_tracer = tracing_init_dentry();
5147 if (!d_tracer)
5148 return 0;
5149
5150 ftrace_init_dyn_debugfs(d_tracer);
5151
Frederic Weisbecker5452af62009-03-27 00:25:38 +01005152 trace_create_file("set_ftrace_pid", 0644, d_tracer,
5153 NULL, &ftrace_pid_fops);
Steven Rostedt493762f2009-03-23 17:12:36 -04005154
5155 ftrace_profile_debugfs(d_tracer);
5156
Steven Rostedtdf4fc312008-11-26 00:16:23 -05005157 return 0;
5158}
Steven Rostedtdf4fc312008-11-26 00:16:23 -05005159fs_initcall(ftrace_init_debugfs);
5160
Steven Rostedt3d083392008-05-12 21:20:42 +02005161/**
Steven Rostedt81adbdc2008-10-23 09:33:02 -04005162 * ftrace_kill - kill ftrace
Steven Rostedta2bb6a32008-07-10 20:58:15 -04005163 *
5164 * This function should be used by panic code. It stops ftrace
5165 * but in a not so nice way. If you need to simply kill ftrace
5166 * from a non-atomic section, use ftrace_kill.
5167 */
Steven Rostedt81adbdc2008-10-23 09:33:02 -04005168void ftrace_kill(void)
Steven Rostedta2bb6a32008-07-10 20:58:15 -04005169{
5170 ftrace_disabled = 1;
5171 ftrace_enabled = 0;
Steven Rostedta2bb6a32008-07-10 20:58:15 -04005172 clear_ftrace_function();
5173}
5174
5175/**
Steven Rostedte0a413f2011-09-29 21:26:16 -04005176 * Test if ftrace is dead or not.
5177 */
5178int ftrace_is_dead(void)
5179{
5180 return ftrace_disabled;
5181}
5182
5183/**
Steven Rostedt3d083392008-05-12 21:20:42 +02005184 * register_ftrace_function - register a function for profiling
5185 * @ops - ops structure that holds the function for profiling.
5186 *
5187 * Register a function to be called by all functions in the
5188 * kernel.
5189 *
5190 * Note: @ops->func and all the functions it calls must be labeled
5191 * with "notrace", otherwise it will go into a
5192 * recursive loop.
5193 */
5194int register_ftrace_function(struct ftrace_ops *ops)
5195{
Steven Rostedt45a4a232011-04-21 23:16:46 -04005196 int ret = -1;
Steven Rostedt4eebcc82008-05-12 21:20:48 +02005197
Masami Hiramatsuf04f24fb2013-05-09 14:44:17 +09005198 ftrace_ops_init(ops);
5199
Steven Rostedte6ea44e2009-02-14 01:42:44 -05005200 mutex_lock(&ftrace_lock);
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01005201
Steven Rostedt (Red Hat)8a56d772013-11-25 20:59:46 -05005202 ret = ftrace_startup(ops, 0);
Steven Rostedtb8489142011-05-04 09:27:52 -04005203
Steven Rostedte6ea44e2009-02-14 01:42:44 -05005204 mutex_unlock(&ftrace_lock);
Borislav Petkov8d240dd2012-03-29 19:11:40 +02005205
Steven Rostedtb0fc4942008-05-12 21:20:43 +02005206 return ret;
Steven Rostedt3d083392008-05-12 21:20:42 +02005207}
Steven Rostedtcdbe61b2011-05-05 21:14:55 -04005208EXPORT_SYMBOL_GPL(register_ftrace_function);
Steven Rostedt3d083392008-05-12 21:20:42 +02005209
5210/**
Uwe Kleine-Koenig32632922009-01-12 23:35:50 +01005211 * unregister_ftrace_function - unregister a function for profiling.
Steven Rostedt3d083392008-05-12 21:20:42 +02005212 * @ops - ops structure that holds the function to unregister
5213 *
5214 * Unregister a function that was added to be called by ftrace profiling.
5215 */
5216int unregister_ftrace_function(struct ftrace_ops *ops)
5217{
5218 int ret;
5219
Steven Rostedte6ea44e2009-02-14 01:42:44 -05005220 mutex_lock(&ftrace_lock);
Steven Rostedt (Red Hat)8a56d772013-11-25 20:59:46 -05005221 ret = ftrace_shutdown(ops, 0);
Steven Rostedte6ea44e2009-02-14 01:42:44 -05005222 mutex_unlock(&ftrace_lock);
Steven Rostedtb0fc4942008-05-12 21:20:43 +02005223
5224 return ret;
5225}
Steven Rostedtcdbe61b2011-05-05 21:14:55 -04005226EXPORT_SYMBOL_GPL(unregister_ftrace_function);
Steven Rostedtb0fc4942008-05-12 21:20:43 +02005227
Ingo Molnare309b412008-05-12 21:20:51 +02005228int
Steven Rostedtb0fc4942008-05-12 21:20:43 +02005229ftrace_enable_sysctl(struct ctl_table *table, int write,
Alexey Dobriyan8d65af72009-09-23 15:57:19 -07005230 void __user *buffer, size_t *lenp,
Steven Rostedtb0fc4942008-05-12 21:20:43 +02005231 loff_t *ppos)
5232{
Steven Rostedt45a4a232011-04-21 23:16:46 -04005233 int ret = -ENODEV;
Steven Rostedt4eebcc82008-05-12 21:20:48 +02005234
Steven Rostedte6ea44e2009-02-14 01:42:44 -05005235 mutex_lock(&ftrace_lock);
Steven Rostedtb0fc4942008-05-12 21:20:43 +02005236
Steven Rostedt45a4a232011-04-21 23:16:46 -04005237 if (unlikely(ftrace_disabled))
5238 goto out;
5239
5240 ret = proc_dointvec(table, write, buffer, lenp, ppos);
Steven Rostedtb0fc4942008-05-12 21:20:43 +02005241
Li Zefana32c7762009-06-26 16:55:51 +08005242 if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
Steven Rostedtb0fc4942008-05-12 21:20:43 +02005243 goto out;
5244
Li Zefana32c7762009-06-26 16:55:51 +08005245 last_ftrace_enabled = !!ftrace_enabled;
Steven Rostedtb0fc4942008-05-12 21:20:43 +02005246
5247 if (ftrace_enabled) {
5248
5249 ftrace_startup_sysctl();
5250
5251 /* we are starting ftrace again */
Jan Kiszka5000c412013-03-26 17:53:03 +01005252 if (ftrace_ops_list != &ftrace_list_end)
5253 update_ftrace_function();
Steven Rostedtb0fc4942008-05-12 21:20:43 +02005254
5255 } else {
5256 /* stopping ftrace calls (just send to ftrace_stub) */
5257 ftrace_trace_function = ftrace_stub;
5258
5259 ftrace_shutdown_sysctl();
5260 }
5261
5262 out:
Steven Rostedte6ea44e2009-02-14 01:42:44 -05005263 mutex_unlock(&ftrace_lock);
Steven Rostedt3d083392008-05-12 21:20:42 +02005264 return ret;
Arnaldo Carvalho de Melo16444a82008-05-12 21:20:42 +02005265}
Ingo Molnarf17845e2008-10-24 12:47:10 +02005266
Frederic Weisbeckerfb526072008-11-25 21:07:04 +01005267#ifdef CONFIG_FUNCTION_GRAPH_TRACER
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01005268
Steven Rostedt (Red Hat)5f151b22014-08-15 17:18:46 -04005269static struct ftrace_ops graph_ops = {
5270 .func = ftrace_stub,
5271 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
5272 FTRACE_OPS_FL_INITIALIZED |
5273 FTRACE_OPS_FL_STUB,
5274#ifdef FTRACE_GRAPH_TRAMP_ADDR
5275 .trampoline = FTRACE_GRAPH_TRAMP_ADDR,
5276#endif
5277 ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash)
5278};
5279
Steven Rostedt597af812009-04-03 15:24:12 -04005280static int ftrace_graph_active;
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005281
Steven Rostedte49dc192008-12-02 23:50:05 -05005282int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
5283{
5284 return 0;
5285}
5286
Frederic Weisbecker287b6e62008-11-26 00:57:25 +01005287/* The callbacks that hook a function */
5288trace_func_graph_ret_t ftrace_graph_return =
5289 (trace_func_graph_ret_t)ftrace_stub;
Steven Rostedte49dc192008-12-02 23:50:05 -05005290trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
Steven Rostedt (Red Hat)23a8e842014-01-13 10:30:23 -05005291static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub;
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005292
5293/* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
5294static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
5295{
5296 int i;
5297 int ret = 0;
5298 unsigned long flags;
5299 int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
5300 struct task_struct *g, *t;
5301
5302 for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
5303 ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH
5304 * sizeof(struct ftrace_ret_stack),
5305 GFP_KERNEL);
5306 if (!ret_stack_list[i]) {
5307 start = 0;
5308 end = i;
5309 ret = -ENOMEM;
5310 goto free;
5311 }
5312 }
5313
5314 read_lock_irqsave(&tasklist_lock, flags);
5315 do_each_thread(g, t) {
5316 if (start == end) {
5317 ret = -EAGAIN;
5318 goto unlock;
5319 }
5320
5321 if (t->ret_stack == NULL) {
Frederic Weisbecker380c4b12008-12-06 03:43:41 +01005322 atomic_set(&t->tracing_graph_pause, 0);
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005323 atomic_set(&t->trace_overrun, 0);
Steven Rostedt26c01622009-06-02 14:01:19 -04005324 t->curr_ret_stack = -1;
5325 /* Make sure the tasks see the -1 first: */
5326 smp_wmb();
5327 t->ret_stack = ret_stack_list[start++];
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005328 }
5329 } while_each_thread(g, t);
5330
5331unlock:
5332 read_unlock_irqrestore(&tasklist_lock, flags);
5333free:
5334 for (i = start; i < end; i++)
5335 kfree(ret_stack_list[i]);
5336 return ret;
5337}
5338
Steven Rostedt8aef2d22009-03-24 01:10:15 -04005339static void
Steven Rostedt38516ab2010-04-20 17:04:50 -04005340ftrace_graph_probe_sched_switch(void *ignore,
5341 struct task_struct *prev, struct task_struct *next)
Steven Rostedt8aef2d22009-03-24 01:10:15 -04005342{
5343 unsigned long long timestamp;
5344 int index;
5345
Steven Rostedtbe6f1642009-03-24 11:06:24 -04005346 /*
5347 * Does the user want to count the time a function was asleep.
5348 * If so, do not update the time stamps.
5349 */
5350 if (trace_flags & TRACE_ITER_SLEEP_TIME)
5351 return;
5352
Steven Rostedt8aef2d22009-03-24 01:10:15 -04005353 timestamp = trace_clock_local();
5354
5355 prev->ftrace_timestamp = timestamp;
5356
5357 /* only process tasks that we timestamped */
5358 if (!next->ftrace_timestamp)
5359 return;
5360
5361 /*
5362 * Update all the counters in next to make up for the
5363 * time next was sleeping.
5364 */
5365 timestamp -= next->ftrace_timestamp;
5366
5367 for (index = next->curr_ret_stack; index >= 0; index--)
5368 next->ret_stack[index].calltime += timestamp;
5369}
5370
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005371/* Allocate a return stack for each task */
Frederic Weisbeckerfb526072008-11-25 21:07:04 +01005372static int start_graph_tracing(void)
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005373{
5374 struct ftrace_ret_stack **ret_stack_list;
Frederic Weisbecker5b058bc2009-02-17 18:35:34 +01005375 int ret, cpu;
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005376
5377 ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
5378 sizeof(struct ftrace_ret_stack *),
5379 GFP_KERNEL);
5380
5381 if (!ret_stack_list)
5382 return -ENOMEM;
5383
Frederic Weisbecker5b058bc2009-02-17 18:35:34 +01005384 /* The cpu_boot init_task->ret_stack will never be freed */
Steven Rostedt179c4982009-06-02 12:03:19 -04005385 for_each_online_cpu(cpu) {
5386 if (!idle_task(cpu)->ret_stack)
Steven Rostedt868baf02011-02-10 21:26:13 -05005387 ftrace_graph_init_idle_task(idle_task(cpu), cpu);
Steven Rostedt179c4982009-06-02 12:03:19 -04005388 }
Frederic Weisbecker5b058bc2009-02-17 18:35:34 +01005389
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005390 do {
5391 ret = alloc_retstack_tasklist(ret_stack_list);
5392 } while (ret == -EAGAIN);
5393
Steven Rostedt8aef2d22009-03-24 01:10:15 -04005394 if (!ret) {
Steven Rostedt38516ab2010-04-20 17:04:50 -04005395 ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
Steven Rostedt8aef2d22009-03-24 01:10:15 -04005396 if (ret)
5397 pr_info("ftrace_graph: Couldn't activate tracepoint"
5398 " probe to kernel_sched_switch\n");
5399 }
5400
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005401 kfree(ret_stack_list);
5402 return ret;
5403}
5404
Frederic Weisbecker4a2b8dd2009-01-14 13:33:27 -08005405/*
5406 * Hibernation protection.
5407 * The state of the current task is too much unstable during
5408 * suspend/restore to disk. We want to protect against that.
5409 */
5410static int
5411ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
5412 void *unused)
5413{
5414 switch (state) {
5415 case PM_HIBERNATION_PREPARE:
5416 pause_graph_tracing();
5417 break;
5418
5419 case PM_POST_HIBERNATION:
5420 unpause_graph_tracing();
5421 break;
5422 }
5423 return NOTIFY_DONE;
5424}
5425
Steven Rostedt (Red Hat)23a8e842014-01-13 10:30:23 -05005426static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace)
5427{
5428 if (!ftrace_ops_test(&global_ops, trace->func, NULL))
5429 return 0;
5430 return __ftrace_graph_entry(trace);
5431}
5432
5433/*
5434 * The function graph tracer should only trace the functions defined
5435 * by set_ftrace_filter and set_ftrace_notrace. If another function
5436 * tracer ops is registered, the graph tracer requires testing the
5437 * function against the global ops, and not just trace any function
5438 * that any ftrace_ops registered.
5439 */
5440static void update_function_graph_func(void)
5441{
Steven Rostedt (Red Hat)5f151b22014-08-15 17:18:46 -04005442 struct ftrace_ops *op;
5443 bool do_test = false;
5444
5445 /*
5446 * The graph and global ops share the same set of functions
5447 * to test. If any other ops is on the list, then
5448 * the graph tracing needs to test if its the function
5449 * it should call.
5450 */
5451 do_for_each_ftrace_op(op, ftrace_ops_list) {
5452 if (op != &global_ops && op != &graph_ops &&
5453 op != &ftrace_list_end) {
5454 do_test = true;
5455 /* in double loop, break out with goto */
5456 goto out;
5457 }
5458 } while_for_each_ftrace_op(op);
5459 out:
5460 if (do_test)
Steven Rostedt (Red Hat)23a8e842014-01-13 10:30:23 -05005461 ftrace_graph_entry = ftrace_graph_entry_test;
Steven Rostedt (Red Hat)5f151b22014-08-15 17:18:46 -04005462 else
5463 ftrace_graph_entry = __ftrace_graph_entry;
Steven Rostedt (Red Hat)23a8e842014-01-13 10:30:23 -05005464}
5465
Mathias Krause8275f692014-03-30 15:31:50 +02005466static struct notifier_block ftrace_suspend_notifier = {
5467 .notifier_call = ftrace_suspend_notifier_call,
5468};
5469
Frederic Weisbecker287b6e62008-11-26 00:57:25 +01005470int register_ftrace_graph(trace_func_graph_ret_t retfunc,
5471 trace_func_graph_ent_t entryfunc)
Frederic Weisbecker15e6cb32008-11-11 07:14:25 +01005472{
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01005473 int ret = 0;
5474
Steven Rostedte6ea44e2009-02-14 01:42:44 -05005475 mutex_lock(&ftrace_lock);
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01005476
Steven Rostedt05ce5812009-03-24 00:18:31 -04005477 /* we currently allow only one tracer registered at a time */
Steven Rostedt597af812009-04-03 15:24:12 -04005478 if (ftrace_graph_active) {
Steven Rostedt05ce5812009-03-24 00:18:31 -04005479 ret = -EBUSY;
5480 goto out;
5481 }
5482
Frederic Weisbecker4a2b8dd2009-01-14 13:33:27 -08005483 register_pm_notifier(&ftrace_suspend_notifier);
5484
Steven Rostedt597af812009-04-03 15:24:12 -04005485 ftrace_graph_active++;
Frederic Weisbeckerfb526072008-11-25 21:07:04 +01005486 ret = start_graph_tracing();
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005487 if (ret) {
Steven Rostedt597af812009-04-03 15:24:12 -04005488 ftrace_graph_active--;
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005489 goto out;
5490 }
Steven Rostedte53a6312008-11-26 00:16:25 -05005491
Frederic Weisbecker287b6e62008-11-26 00:57:25 +01005492 ftrace_graph_return = retfunc;
Steven Rostedt (Red Hat)23a8e842014-01-13 10:30:23 -05005493
5494 /*
5495 * Update the indirect function to the entryfunc, and the
5496 * function that gets called to the entry_test first. Then
5497 * call the update fgraph entry function to determine if
5498 * the entryfunc should be called directly or not.
5499 */
5500 __ftrace_graph_entry = entryfunc;
5501 ftrace_graph_entry = ftrace_graph_entry_test;
5502 update_function_graph_func();
Steven Rostedte53a6312008-11-26 00:16:25 -05005503
Steven Rostedt (Red Hat)5f151b22014-08-15 17:18:46 -04005504 ret = ftrace_startup(&graph_ops, FTRACE_START_FUNC_RET);
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01005505
5506out:
Steven Rostedte6ea44e2009-02-14 01:42:44 -05005507 mutex_unlock(&ftrace_lock);
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01005508 return ret;
Frederic Weisbecker15e6cb32008-11-11 07:14:25 +01005509}
5510
Frederic Weisbeckerfb526072008-11-25 21:07:04 +01005511void unregister_ftrace_graph(void)
Frederic Weisbecker15e6cb32008-11-11 07:14:25 +01005512{
Steven Rostedte6ea44e2009-02-14 01:42:44 -05005513 mutex_lock(&ftrace_lock);
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01005514
Steven Rostedt597af812009-04-03 15:24:12 -04005515 if (unlikely(!ftrace_graph_active))
Steven Rostedt2aad1b72009-03-30 11:11:28 -04005516 goto out;
5517
Steven Rostedt597af812009-04-03 15:24:12 -04005518 ftrace_graph_active--;
Frederic Weisbecker287b6e62008-11-26 00:57:25 +01005519 ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
Steven Rostedte49dc192008-12-02 23:50:05 -05005520 ftrace_graph_entry = ftrace_graph_entry_stub;
Steven Rostedt (Red Hat)23a8e842014-01-13 10:30:23 -05005521 __ftrace_graph_entry = ftrace_graph_entry_stub;
Steven Rostedt (Red Hat)5f151b22014-08-15 17:18:46 -04005522 ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET);
Frederic Weisbecker4a2b8dd2009-01-14 13:33:27 -08005523 unregister_pm_notifier(&ftrace_suspend_notifier);
Steven Rostedt38516ab2010-04-20 17:04:50 -04005524 unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
Frederic Weisbeckere7d37372008-11-16 06:02:06 +01005525
Steven Rostedt2aad1b72009-03-30 11:11:28 -04005526 out:
Steven Rostedte6ea44e2009-02-14 01:42:44 -05005527 mutex_unlock(&ftrace_lock);
Frederic Weisbecker15e6cb32008-11-11 07:14:25 +01005528}
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005529
Steven Rostedt868baf02011-02-10 21:26:13 -05005530static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack);
5531
5532static void
5533graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack)
5534{
5535 atomic_set(&t->tracing_graph_pause, 0);
5536 atomic_set(&t->trace_overrun, 0);
5537 t->ftrace_timestamp = 0;
Lucas De Marchi25985ed2011-03-30 22:57:33 -03005538 /* make curr_ret_stack visible before we add the ret_stack */
Steven Rostedt868baf02011-02-10 21:26:13 -05005539 smp_wmb();
5540 t->ret_stack = ret_stack;
5541}
5542
5543/*
5544 * Allocate a return stack for the idle task. May be the first
5545 * time through, or it may be done by CPU hotplug online.
5546 */
5547void ftrace_graph_init_idle_task(struct task_struct *t, int cpu)
5548{
5549 t->curr_ret_stack = -1;
5550 /*
5551 * The idle task has no parent, it either has its own
5552 * stack or no stack at all.
5553 */
5554 if (t->ret_stack)
5555 WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu));
5556
5557 if (ftrace_graph_active) {
5558 struct ftrace_ret_stack *ret_stack;
5559
5560 ret_stack = per_cpu(idle_ret_stack, cpu);
5561 if (!ret_stack) {
5562 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
5563 * sizeof(struct ftrace_ret_stack),
5564 GFP_KERNEL);
5565 if (!ret_stack)
5566 return;
5567 per_cpu(idle_ret_stack, cpu) = ret_stack;
5568 }
5569 graph_init_task(t, ret_stack);
5570 }
5571}
5572
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005573/* Allocate a return stack for newly created task */
Frederic Weisbeckerfb526072008-11-25 21:07:04 +01005574void ftrace_graph_init_task(struct task_struct *t)
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005575{
Steven Rostedt84047e32009-06-02 16:51:55 -04005576 /* Make sure we do not use the parent ret_stack */
5577 t->ret_stack = NULL;
Steven Rostedtea14eb72010-03-12 19:41:23 -05005578 t->curr_ret_stack = -1;
Steven Rostedt84047e32009-06-02 16:51:55 -04005579
Steven Rostedt597af812009-04-03 15:24:12 -04005580 if (ftrace_graph_active) {
Steven Rostedt82310a32009-06-02 12:26:07 -04005581 struct ftrace_ret_stack *ret_stack;
5582
5583 ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005584 * sizeof(struct ftrace_ret_stack),
5585 GFP_KERNEL);
Steven Rostedt82310a32009-06-02 12:26:07 -04005586 if (!ret_stack)
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005587 return;
Steven Rostedt868baf02011-02-10 21:26:13 -05005588 graph_init_task(t, ret_stack);
Steven Rostedt84047e32009-06-02 16:51:55 -04005589 }
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005590}
5591
Frederic Weisbeckerfb526072008-11-25 21:07:04 +01005592void ftrace_graph_exit_task(struct task_struct *t)
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005593{
Frederic Weisbeckereae849c2008-11-23 17:33:12 +01005594 struct ftrace_ret_stack *ret_stack = t->ret_stack;
5595
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005596 t->ret_stack = NULL;
Frederic Weisbeckereae849c2008-11-23 17:33:12 +01005597 /* NULL must become visible to IRQs before we free it: */
5598 barrier();
5599
5600 kfree(ret_stack);
Frederic Weisbeckerf201ae22008-11-23 06:22:56 +01005601}
Frederic Weisbecker15e6cb32008-11-11 07:14:25 +01005602#endif