2 * Infrastructure for profiling code inserted by 'gcc -pg'.
4 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
5 * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
7 * Originally ported from the -rt patch by:
8 * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
10 * Based on code in the latency_tracer, that is:
12 * Copyright (C) 2004-2006 Ingo Molnar
13 * Copyright (C) 2004 William Lee Irwin III
16 #include <linux/stop_machine.h>
17 #include <linux/clocksource.h>
18 #include <linux/kallsyms.h>
19 #include <linux/seq_file.h>
20 #include <linux/debugfs.h>
21 #include <linux/hardirq.h>
22 #include <linux/kthread.h>
23 #include <linux/uaccess.h>
24 #include <linux/kprobes.h>
25 #include <linux/ftrace.h>
26 #include <linux/sysctl.h>
27 #include <linux/ctype.h>
28 #include <linux/list.h>
30 #include <asm/ftrace.h>
34 #define FTRACE_WARN_ON(cond) \
40 #define FTRACE_WARN_ON_ONCE(cond) \
42 if (WARN_ON_ONCE(cond)) \
46 /* ftrace_enabled is a method to turn ftrace on or off */
47 int ftrace_enabled __read_mostly;
48 static int last_ftrace_enabled;
51 * ftrace_disabled is set when an anomaly is discovered.
52 * ftrace_disabled is much stronger than ftrace_enabled.
54 static int ftrace_disabled __read_mostly;
56 static DEFINE_SPINLOCK(ftrace_lock);
57 static DEFINE_MUTEX(ftrace_sysctl_lock);
59 static struct ftrace_ops ftrace_list_end __read_mostly =
64 static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end;
65 ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
67 static void ftrace_list_func(unsigned long ip, unsigned long parent_ip)
69 struct ftrace_ops *op = ftrace_list;
71 /* in case someone actually ports this to alpha! */
72 read_barrier_depends();
74 while (op != &ftrace_list_end) {
76 read_barrier_depends();
77 op->func(ip, parent_ip);
83 * clear_ftrace_function - reset the ftrace function
85 * This NULLs the ftrace function and in essence stops
86 * tracing. There may be lag
88 void clear_ftrace_function(void)
90 ftrace_trace_function = ftrace_stub;
93 static int __register_ftrace_function(struct ftrace_ops *ops)
95 /* should not be called from interrupt context */
96 spin_lock(&ftrace_lock);
98 ops->next = ftrace_list;
100 * We are entering ops into the ftrace_list but another
101 * CPU might be walking that list. We need to make sure
102 * the ops->next pointer is valid before another CPU sees
103 * the ops pointer included into the ftrace_list.
108 if (ftrace_enabled) {
110 * For one func, simply call it directly.
111 * For more than one func, call the chain.
113 if (ops->next == &ftrace_list_end)
114 ftrace_trace_function = ops->func;
116 ftrace_trace_function = ftrace_list_func;
119 spin_unlock(&ftrace_lock);
124 static int __unregister_ftrace_function(struct ftrace_ops *ops)
126 struct ftrace_ops **p;
129 /* should not be called from interrupt context */
130 spin_lock(&ftrace_lock);
133 * If we are removing the last function, then simply point
134 * to the ftrace_stub.
136 if (ftrace_list == ops && ops->next == &ftrace_list_end) {
137 ftrace_trace_function = ftrace_stub;
138 ftrace_list = &ftrace_list_end;
142 for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next)
153 if (ftrace_enabled) {
154 /* If we only have one func left, then call that directly */
155 if (ftrace_list == &ftrace_list_end ||
156 ftrace_list->next == &ftrace_list_end)
157 ftrace_trace_function = ftrace_list->func;
161 spin_unlock(&ftrace_lock);
166 #ifdef CONFIG_DYNAMIC_FTRACE
167 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
168 # error Dynamic ftrace depends on MCOUNT_RECORD
172 * Since MCOUNT_ADDR may point to mcount itself, we do not want
173 * to get it confused by reading a reference in the code as we
174 * are parsing on objcopy output of text. Use a variable for
177 static unsigned long mcount_addr = MCOUNT_ADDR;
180 FTRACE_ENABLE_CALLS = (1 << 0),
181 FTRACE_DISABLE_CALLS = (1 << 1),
182 FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
183 FTRACE_ENABLE_MCOUNT = (1 << 3),
184 FTRACE_DISABLE_MCOUNT = (1 << 4),
187 static int ftrace_filtered;
188 static int tracing_on;
190 static LIST_HEAD(ftrace_new_addrs);
192 static DEFINE_MUTEX(ftrace_regex_lock);
195 struct ftrace_page *next;
197 struct dyn_ftrace records[];
200 #define ENTRIES_PER_PAGE \
201 ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace))
203 /* estimate from running different kernels */
204 #define NR_TO_INIT 10000
206 static struct ftrace_page *ftrace_pages_start;
207 static struct ftrace_page *ftrace_pages;
209 static struct dyn_ftrace *ftrace_free_records;
212 #ifdef CONFIG_KPROBES
214 static int frozen_record_count;
216 static inline void freeze_record(struct dyn_ftrace *rec)
218 if (!(rec->flags & FTRACE_FL_FROZEN)) {
219 rec->flags |= FTRACE_FL_FROZEN;
220 frozen_record_count++;
224 static inline void unfreeze_record(struct dyn_ftrace *rec)
226 if (rec->flags & FTRACE_FL_FROZEN) {
227 rec->flags &= ~FTRACE_FL_FROZEN;
228 frozen_record_count--;
232 static inline int record_frozen(struct dyn_ftrace *rec)
234 return rec->flags & FTRACE_FL_FROZEN;
237 # define freeze_record(rec) ({ 0; })
238 # define unfreeze_record(rec) ({ 0; })
239 # define record_frozen(rec) ({ 0; })
240 #endif /* CONFIG_KPROBES */
242 static void ftrace_free_rec(struct dyn_ftrace *rec)
244 rec->ip = (unsigned long)ftrace_free_records;
245 ftrace_free_records = rec;
246 rec->flags |= FTRACE_FL_FREE;
249 void ftrace_release(void *start, unsigned long size)
251 struct dyn_ftrace *rec;
252 struct ftrace_page *pg;
253 unsigned long s = (unsigned long)start;
254 unsigned long e = s + size;
257 if (ftrace_disabled || !start)
260 /* should not be called from interrupt context */
261 spin_lock(&ftrace_lock);
263 for (pg = ftrace_pages_start; pg; pg = pg->next) {
264 for (i = 0; i < pg->index; i++) {
265 rec = &pg->records[i];
267 if ((rec->ip >= s) && (rec->ip < e))
268 ftrace_free_rec(rec);
271 spin_unlock(&ftrace_lock);
274 static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
276 struct dyn_ftrace *rec;
278 /* First check for freed records */
279 if (ftrace_free_records) {
280 rec = ftrace_free_records;
282 if (unlikely(!(rec->flags & FTRACE_FL_FREE))) {
283 FTRACE_WARN_ON_ONCE(1);
284 ftrace_free_records = NULL;
288 ftrace_free_records = (void *)rec->ip;
289 memset(rec, 0, sizeof(*rec));
293 if (ftrace_pages->index == ENTRIES_PER_PAGE) {
294 if (!ftrace_pages->next) {
295 /* allocate another page */
297 (void *)get_zeroed_page(GFP_KERNEL);
298 if (!ftrace_pages->next)
301 ftrace_pages = ftrace_pages->next;
304 return &ftrace_pages->records[ftrace_pages->index++];
307 static struct dyn_ftrace *
308 ftrace_record_ip(unsigned long ip)
310 struct dyn_ftrace *rec;
312 if (!ftrace_enabled || ftrace_disabled)
315 rec = ftrace_alloc_dyn_node(ip);
321 list_add(&rec->list, &ftrace_new_addrs);
326 #define FTRACE_ADDR ((long)(ftrace_caller))
329 __ftrace_replace_code(struct dyn_ftrace *rec,
330 unsigned char *old, unsigned char *new, int enable)
332 unsigned long ip, fl;
336 if (ftrace_filtered && enable) {
338 * If filtering is on:
340 * If this record is set to be filtered and
341 * is enabled then do nothing.
343 * If this record is set to be filtered and
344 * it is not enabled, enable it.
346 * If this record is not set to be filtered
347 * and it is not enabled do nothing.
349 * If this record is set not to trace then
352 * If this record is set not to trace and
353 * it is enabled then disable it.
355 * If this record is not set to be filtered and
356 * it is enabled, disable it.
359 fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE |
362 if ((fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) ||
363 (fl == (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE)) ||
364 !fl || (fl == FTRACE_FL_NOTRACE))
368 * If it is enabled disable it,
369 * otherwise enable it!
371 if (fl & FTRACE_FL_ENABLED) {
372 /* swap new and old */
374 old = ftrace_call_replace(ip, FTRACE_ADDR);
375 rec->flags &= ~FTRACE_FL_ENABLED;
377 new = ftrace_call_replace(ip, FTRACE_ADDR);
378 rec->flags |= FTRACE_FL_ENABLED;
384 * If this record is set not to trace and is
385 * not enabled, do nothing.
387 fl = rec->flags & (FTRACE_FL_NOTRACE | FTRACE_FL_ENABLED);
388 if (fl == FTRACE_FL_NOTRACE)
391 new = ftrace_call_replace(ip, FTRACE_ADDR);
393 old = ftrace_call_replace(ip, FTRACE_ADDR);
396 if (rec->flags & FTRACE_FL_ENABLED)
398 rec->flags |= FTRACE_FL_ENABLED;
400 if (!(rec->flags & FTRACE_FL_ENABLED))
402 rec->flags &= ~FTRACE_FL_ENABLED;
406 return ftrace_modify_code(ip, old, new);
409 static void ftrace_replace_code(int enable)
412 unsigned char *new = NULL, *old = NULL;
413 struct dyn_ftrace *rec;
414 struct ftrace_page *pg;
417 old = ftrace_nop_replace();
419 new = ftrace_nop_replace();
421 for (pg = ftrace_pages_start; pg; pg = pg->next) {
422 for (i = 0; i < pg->index; i++) {
423 rec = &pg->records[i];
425 /* don't modify code that has already faulted */
426 if (rec->flags & FTRACE_FL_FAILED)
429 /* ignore updates to this record's mcount site */
430 if (get_kprobe((void *)rec->ip)) {
434 unfreeze_record(rec);
437 failed = __ftrace_replace_code(rec, old, new, enable);
438 if (failed && (rec->flags & FTRACE_FL_CONVERTED)) {
439 rec->flags |= FTRACE_FL_FAILED;
440 if ((system_state == SYSTEM_BOOTING) ||
441 !core_kernel_text(rec->ip)) {
442 ftrace_free_rec(rec);
449 static void print_ip_ins(const char *fmt, unsigned char *p)
453 printk(KERN_CONT "%s", fmt);
455 for (i = 0; i < MCOUNT_INSN_SIZE; i++)
456 printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
460 ftrace_code_disable(struct dyn_ftrace *rec)
463 unsigned char *nop, *call;
468 nop = ftrace_nop_replace();
469 call = ftrace_call_replace(ip, mcount_addr);
471 ret = ftrace_modify_code(ip, call, nop);
475 FTRACE_WARN_ON_ONCE(1);
476 pr_info("ftrace faulted on modifying ");
480 FTRACE_WARN_ON_ONCE(1);
481 pr_info("ftrace failed to modify ");
483 print_ip_ins(" expected: ", call);
484 print_ip_ins(" actual: ", (unsigned char *)ip);
485 print_ip_ins(" replace: ", nop);
486 printk(KERN_CONT "\n");
489 FTRACE_WARN_ON_ONCE(1);
490 pr_info("ftrace faulted on writing ");
494 FTRACE_WARN_ON_ONCE(1);
495 pr_info("ftrace faulted on unknown error ");
499 rec->flags |= FTRACE_FL_FAILED;
505 static int __ftrace_modify_code(void *data)
509 if (*command & FTRACE_ENABLE_CALLS) {
510 ftrace_replace_code(1);
512 } else if (*command & FTRACE_DISABLE_CALLS) {
513 ftrace_replace_code(0);
517 if (*command & FTRACE_UPDATE_TRACE_FUNC)
518 ftrace_update_ftrace_func(ftrace_trace_function);
523 static void ftrace_run_update_code(int command)
525 stop_machine(__ftrace_modify_code, &command, NULL);
528 static ftrace_func_t saved_ftrace_func;
529 static int ftrace_start;
530 static DEFINE_MUTEX(ftrace_start_lock);
532 static void ftrace_startup(void)
536 if (unlikely(ftrace_disabled))
539 mutex_lock(&ftrace_start_lock);
541 if (ftrace_start == 1)
542 command |= FTRACE_ENABLE_CALLS;
544 if (saved_ftrace_func != ftrace_trace_function) {
545 saved_ftrace_func = ftrace_trace_function;
546 command |= FTRACE_UPDATE_TRACE_FUNC;
549 if (!command || !ftrace_enabled)
552 ftrace_run_update_code(command);
554 mutex_unlock(&ftrace_start_lock);
557 static void ftrace_shutdown(void)
561 if (unlikely(ftrace_disabled))
564 mutex_lock(&ftrace_start_lock);
567 command |= FTRACE_DISABLE_CALLS;
569 if (saved_ftrace_func != ftrace_trace_function) {
570 saved_ftrace_func = ftrace_trace_function;
571 command |= FTRACE_UPDATE_TRACE_FUNC;
574 if (!command || !ftrace_enabled)
577 ftrace_run_update_code(command);
579 mutex_unlock(&ftrace_start_lock);
582 static void ftrace_startup_sysctl(void)
584 int command = FTRACE_ENABLE_MCOUNT;
586 if (unlikely(ftrace_disabled))
589 mutex_lock(&ftrace_start_lock);
590 /* Force update next time */
591 saved_ftrace_func = NULL;
592 /* ftrace_start is true if we want ftrace running */
594 command |= FTRACE_ENABLE_CALLS;
596 ftrace_run_update_code(command);
597 mutex_unlock(&ftrace_start_lock);
600 static void ftrace_shutdown_sysctl(void)
602 int command = FTRACE_DISABLE_MCOUNT;
604 if (unlikely(ftrace_disabled))
607 mutex_lock(&ftrace_start_lock);
608 /* ftrace_start is true if ftrace is running */
610 command |= FTRACE_DISABLE_CALLS;
612 ftrace_run_update_code(command);
613 mutex_unlock(&ftrace_start_lock);
616 static cycle_t ftrace_update_time;
617 static unsigned long ftrace_update_cnt;
618 unsigned long ftrace_update_tot_cnt;
620 static int ftrace_update_code(void)
622 struct dyn_ftrace *p, *t;
625 start = ftrace_now(raw_smp_processor_id());
626 ftrace_update_cnt = 0;
628 list_for_each_entry_safe(p, t, &ftrace_new_addrs, list) {
630 /* If something went wrong, bail without enabling anything */
631 if (unlikely(ftrace_disabled))
634 list_del_init(&p->list);
636 /* convert record (i.e, patch mcount-call with NOP) */
637 if (ftrace_code_disable(p)) {
638 p->flags |= FTRACE_FL_CONVERTED;
644 stop = ftrace_now(raw_smp_processor_id());
645 ftrace_update_time = stop - start;
646 ftrace_update_tot_cnt += ftrace_update_cnt;
651 static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
653 struct ftrace_page *pg;
657 /* allocate a few pages */
658 ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL);
659 if (!ftrace_pages_start)
663 * Allocate a few more pages.
665 * TODO: have some parser search vmlinux before
666 * final linking to find all calls to ftrace.
668 * a) know how many pages to allocate.
670 * b) set up the table then.
672 * The dynamic code is still necessary for
676 pg = ftrace_pages = ftrace_pages_start;
678 cnt = num_to_init / ENTRIES_PER_PAGE;
679 pr_info("ftrace: allocating %ld entries in %d pages\n",
682 for (i = 0; i < cnt; i++) {
683 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
685 /* If we fail, we'll try later anyway */
696 FTRACE_ITER_FILTER = (1 << 0),
697 FTRACE_ITER_CONT = (1 << 1),
698 FTRACE_ITER_NOTRACE = (1 << 2),
699 FTRACE_ITER_FAILURES = (1 << 3),
702 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
704 struct ftrace_iterator {
706 struct ftrace_page *pg;
709 unsigned char buffer[FTRACE_BUFF_MAX+1];
715 t_next(struct seq_file *m, void *v, loff_t *pos)
717 struct ftrace_iterator *iter = m->private;
718 struct dyn_ftrace *rec = NULL;
722 /* should not be called from interrupt context */
723 spin_lock(&ftrace_lock);
725 if (iter->idx >= iter->pg->index) {
726 if (iter->pg->next) {
727 iter->pg = iter->pg->next;
732 rec = &iter->pg->records[iter->idx++];
733 if ((rec->flags & FTRACE_FL_FREE) ||
735 (!(iter->flags & FTRACE_ITER_FAILURES) &&
736 (rec->flags & FTRACE_FL_FAILED)) ||
738 ((iter->flags & FTRACE_ITER_FAILURES) &&
739 !(rec->flags & FTRACE_FL_FAILED)) ||
741 ((iter->flags & FTRACE_ITER_FILTER) &&
742 !(rec->flags & FTRACE_FL_FILTER)) ||
744 ((iter->flags & FTRACE_ITER_NOTRACE) &&
745 !(rec->flags & FTRACE_FL_NOTRACE))) {
750 spin_unlock(&ftrace_lock);
757 static void *t_start(struct seq_file *m, loff_t *pos)
759 struct ftrace_iterator *iter = m->private;
763 if (*pos != iter->pos) {
764 for (p = t_next(m, p, &l); p && l < *pos; p = t_next(m, p, &l))
768 p = t_next(m, p, &l);
774 static void t_stop(struct seq_file *m, void *p)
778 static int t_show(struct seq_file *m, void *v)
780 struct dyn_ftrace *rec = v;
781 char str[KSYM_SYMBOL_LEN];
786 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
788 seq_printf(m, "%s\n", str);
793 static struct seq_operations show_ftrace_seq_ops = {
801 ftrace_avail_open(struct inode *inode, struct file *file)
803 struct ftrace_iterator *iter;
806 if (unlikely(ftrace_disabled))
809 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
813 iter->pg = ftrace_pages_start;
816 ret = seq_open(file, &show_ftrace_seq_ops);
818 struct seq_file *m = file->private_data;
828 int ftrace_avail_release(struct inode *inode, struct file *file)
830 struct seq_file *m = (struct seq_file *)file->private_data;
831 struct ftrace_iterator *iter = m->private;
833 seq_release(inode, file);
840 ftrace_failures_open(struct inode *inode, struct file *file)
844 struct ftrace_iterator *iter;
846 ret = ftrace_avail_open(inode, file);
848 m = (struct seq_file *)file->private_data;
849 iter = (struct ftrace_iterator *)m->private;
850 iter->flags = FTRACE_ITER_FAILURES;
857 static void ftrace_filter_reset(int enable)
859 struct ftrace_page *pg;
860 struct dyn_ftrace *rec;
861 unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
864 /* should not be called from interrupt context */
865 spin_lock(&ftrace_lock);
868 pg = ftrace_pages_start;
870 for (i = 0; i < pg->index; i++) {
871 rec = &pg->records[i];
872 if (rec->flags & FTRACE_FL_FAILED)
878 spin_unlock(&ftrace_lock);
882 ftrace_regex_open(struct inode *inode, struct file *file, int enable)
884 struct ftrace_iterator *iter;
887 if (unlikely(ftrace_disabled))
890 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
894 mutex_lock(&ftrace_regex_lock);
895 if ((file->f_mode & FMODE_WRITE) &&
896 !(file->f_flags & O_APPEND))
897 ftrace_filter_reset(enable);
899 if (file->f_mode & FMODE_READ) {
900 iter->pg = ftrace_pages_start;
902 iter->flags = enable ? FTRACE_ITER_FILTER :
905 ret = seq_open(file, &show_ftrace_seq_ops);
907 struct seq_file *m = file->private_data;
912 file->private_data = iter;
913 mutex_unlock(&ftrace_regex_lock);
919 ftrace_filter_open(struct inode *inode, struct file *file)
921 return ftrace_regex_open(inode, file, 1);
925 ftrace_notrace_open(struct inode *inode, struct file *file)
927 return ftrace_regex_open(inode, file, 0);
931 ftrace_regex_read(struct file *file, char __user *ubuf,
932 size_t cnt, loff_t *ppos)
934 if (file->f_mode & FMODE_READ)
935 return seq_read(file, ubuf, cnt, ppos);
941 ftrace_regex_lseek(struct file *file, loff_t offset, int origin)
945 if (file->f_mode & FMODE_READ)
946 ret = seq_lseek(file, offset, origin);
948 file->f_pos = ret = 1;
961 ftrace_match(unsigned char *buff, int len, int enable)
963 char str[KSYM_SYMBOL_LEN];
965 struct ftrace_page *pg;
966 struct dyn_ftrace *rec;
967 int type = MATCH_FULL;
968 unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
969 unsigned i, match = 0, search_len = 0;
971 for (i = 0; i < len; i++) {
972 if (buff[i] == '*') {
974 search = buff + i + 1;
975 type = MATCH_END_ONLY;
976 search_len = len - (i + 1);
978 if (type == MATCH_END_ONLY) {
979 type = MATCH_MIDDLE_ONLY;
982 type = MATCH_FRONT_ONLY;
990 /* should not be called from interrupt context */
991 spin_lock(&ftrace_lock);
994 pg = ftrace_pages_start;
996 for (i = 0; i < pg->index; i++) {
1000 rec = &pg->records[i];
1001 if (rec->flags & FTRACE_FL_FAILED)
1003 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
1006 if (strcmp(str, buff) == 0)
1009 case MATCH_FRONT_ONLY:
1010 if (memcmp(str, buff, match) == 0)
1013 case MATCH_MIDDLE_ONLY:
1014 if (strstr(str, search))
1017 case MATCH_END_ONLY:
1018 ptr = strstr(str, search);
1019 if (ptr && (ptr[search_len] == 0))
1028 spin_unlock(&ftrace_lock);
1032 ftrace_regex_write(struct file *file, const char __user *ubuf,
1033 size_t cnt, loff_t *ppos, int enable)
1035 struct ftrace_iterator *iter;
1040 if (!cnt || cnt < 0)
1043 mutex_lock(&ftrace_regex_lock);
1045 if (file->f_mode & FMODE_READ) {
1046 struct seq_file *m = file->private_data;
1049 iter = file->private_data;
1052 iter->flags &= ~FTRACE_ITER_CONT;
1053 iter->buffer_idx = 0;
1056 ret = get_user(ch, ubuf++);
1062 if (!(iter->flags & ~FTRACE_ITER_CONT)) {
1063 /* skip white space */
1064 while (cnt && isspace(ch)) {
1065 ret = get_user(ch, ubuf++);
1073 file->f_pos += read;
1078 iter->buffer_idx = 0;
1081 while (cnt && !isspace(ch)) {
1082 if (iter->buffer_idx < FTRACE_BUFF_MAX)
1083 iter->buffer[iter->buffer_idx++] = ch;
1088 ret = get_user(ch, ubuf++);
1097 iter->buffer[iter->buffer_idx] = 0;
1098 ftrace_match(iter->buffer, iter->buffer_idx, enable);
1099 iter->buffer_idx = 0;
1101 iter->flags |= FTRACE_ITER_CONT;
1104 file->f_pos += read;
1108 mutex_unlock(&ftrace_regex_lock);
1114 ftrace_filter_write(struct file *file, const char __user *ubuf,
1115 size_t cnt, loff_t *ppos)
1117 return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
1121 ftrace_notrace_write(struct file *file, const char __user *ubuf,
1122 size_t cnt, loff_t *ppos)
1124 return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
1128 ftrace_set_regex(unsigned char *buf, int len, int reset, int enable)
1130 if (unlikely(ftrace_disabled))
1133 mutex_lock(&ftrace_regex_lock);
1135 ftrace_filter_reset(enable);
1137 ftrace_match(buf, len, enable);
1138 mutex_unlock(&ftrace_regex_lock);
1142 * ftrace_set_filter - set a function to filter on in ftrace
1143 * @buf - the string that holds the function filter text.
1144 * @len - the length of the string.
1145 * @reset - non zero to reset all filters before applying this filter.
1147 * Filters denote which functions should be enabled when tracing is enabled.
1148 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
1150 void ftrace_set_filter(unsigned char *buf, int len, int reset)
1152 ftrace_set_regex(buf, len, reset, 1);
1156 * ftrace_set_notrace - set a function to not trace in ftrace
1157 * @buf - the string that holds the function notrace text.
1158 * @len - the length of the string.
1159 * @reset - non zero to reset all filters before applying this filter.
1161 * Notrace Filters denote which functions should not be enabled when tracing
1162 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
1165 void ftrace_set_notrace(unsigned char *buf, int len, int reset)
1167 ftrace_set_regex(buf, len, reset, 0);
1171 ftrace_regex_release(struct inode *inode, struct file *file, int enable)
1173 struct seq_file *m = (struct seq_file *)file->private_data;
1174 struct ftrace_iterator *iter;
1176 mutex_lock(&ftrace_regex_lock);
1177 if (file->f_mode & FMODE_READ) {
1180 seq_release(inode, file);
1182 iter = file->private_data;
1184 if (iter->buffer_idx) {
1186 iter->buffer[iter->buffer_idx] = 0;
1187 ftrace_match(iter->buffer, iter->buffer_idx, enable);
1190 mutex_lock(&ftrace_sysctl_lock);
1191 mutex_lock(&ftrace_start_lock);
1192 if (iter->filtered && ftrace_start && ftrace_enabled)
1193 ftrace_run_update_code(FTRACE_ENABLE_CALLS);
1194 mutex_unlock(&ftrace_start_lock);
1195 mutex_unlock(&ftrace_sysctl_lock);
1198 mutex_unlock(&ftrace_regex_lock);
1203 ftrace_filter_release(struct inode *inode, struct file *file)
1205 return ftrace_regex_release(inode, file, 1);
1209 ftrace_notrace_release(struct inode *inode, struct file *file)
1211 return ftrace_regex_release(inode, file, 0);
1214 static struct file_operations ftrace_avail_fops = {
1215 .open = ftrace_avail_open,
1217 .llseek = seq_lseek,
1218 .release = ftrace_avail_release,
1221 static struct file_operations ftrace_failures_fops = {
1222 .open = ftrace_failures_open,
1224 .llseek = seq_lseek,
1225 .release = ftrace_avail_release,
1228 static struct file_operations ftrace_filter_fops = {
1229 .open = ftrace_filter_open,
1230 .read = ftrace_regex_read,
1231 .write = ftrace_filter_write,
1232 .llseek = ftrace_regex_lseek,
1233 .release = ftrace_filter_release,
1236 static struct file_operations ftrace_notrace_fops = {
1237 .open = ftrace_notrace_open,
1238 .read = ftrace_regex_read,
1239 .write = ftrace_notrace_write,
1240 .llseek = ftrace_regex_lseek,
1241 .release = ftrace_notrace_release,
1244 static __init int ftrace_init_debugfs(void)
1246 struct dentry *d_tracer;
1247 struct dentry *entry;
1249 d_tracer = tracing_init_dentry();
1251 entry = debugfs_create_file("available_filter_functions", 0444,
1252 d_tracer, NULL, &ftrace_avail_fops);
1254 pr_warning("Could not create debugfs "
1255 "'available_filter_functions' entry\n");
1257 entry = debugfs_create_file("failures", 0444,
1258 d_tracer, NULL, &ftrace_failures_fops);
1260 pr_warning("Could not create debugfs 'failures' entry\n");
1262 entry = debugfs_create_file("set_ftrace_filter", 0644, d_tracer,
1263 NULL, &ftrace_filter_fops);
1265 pr_warning("Could not create debugfs "
1266 "'set_ftrace_filter' entry\n");
1268 entry = debugfs_create_file("set_ftrace_notrace", 0644, d_tracer,
1269 NULL, &ftrace_notrace_fops);
1271 pr_warning("Could not create debugfs "
1272 "'set_ftrace_notrace' entry\n");
1277 fs_initcall(ftrace_init_debugfs);
1279 static int ftrace_convert_nops(unsigned long *start,
1284 unsigned long flags;
1286 mutex_lock(&ftrace_start_lock);
1289 addr = ftrace_call_adjust(*p++);
1290 ftrace_record_ip(addr);
1293 /* disable interrupts to prevent kstop machine */
1294 local_irq_save(flags);
1295 ftrace_update_code();
1296 local_irq_restore(flags);
1297 mutex_unlock(&ftrace_start_lock);
1302 void ftrace_init_module(unsigned long *start, unsigned long *end)
1304 if (ftrace_disabled || start == end)
1306 ftrace_convert_nops(start, end);
1309 extern unsigned long __start_mcount_loc[];
1310 extern unsigned long __stop_mcount_loc[];
1312 void __init ftrace_init(void)
1314 unsigned long count, addr, flags;
1317 /* Keep the ftrace pointer to the stub */
1318 addr = (unsigned long)ftrace_stub;
1320 local_irq_save(flags);
1321 ftrace_dyn_arch_init(&addr);
1322 local_irq_restore(flags);
1324 /* ftrace_dyn_arch_init places the return code in addr */
1328 count = __stop_mcount_loc - __start_mcount_loc;
1330 ret = ftrace_dyn_table_alloc(count);
1334 last_ftrace_enabled = ftrace_enabled = 1;
1336 ret = ftrace_convert_nops(__start_mcount_loc,
1341 ftrace_disabled = 1;
1346 static int __init ftrace_nodyn_init(void)
1351 device_initcall(ftrace_nodyn_init);
1353 # define ftrace_startup() do { } while (0)
1354 # define ftrace_shutdown() do { } while (0)
1355 # define ftrace_startup_sysctl() do { } while (0)
1356 # define ftrace_shutdown_sysctl() do { } while (0)
1357 #endif /* CONFIG_DYNAMIC_FTRACE */
1360 * ftrace_kill - kill ftrace
1362 * This function should be used by panic code. It stops ftrace
1363 * but in a not so nice way. If you need to simply kill ftrace
1364 * from a non-atomic section, use ftrace_kill.
1366 void ftrace_kill(void)
1368 ftrace_disabled = 1;
1370 clear_ftrace_function();
1374 * register_ftrace_function - register a function for profiling
1375 * @ops - ops structure that holds the function for profiling.
1377 * Register a function to be called by all functions in the
1380 * Note: @ops->func and all the functions it calls must be labeled
1381 * with "notrace", otherwise it will go into a
1384 int register_ftrace_function(struct ftrace_ops *ops)
1388 if (unlikely(ftrace_disabled))
1391 mutex_lock(&ftrace_sysctl_lock);
1392 ret = __register_ftrace_function(ops);
1394 mutex_unlock(&ftrace_sysctl_lock);
1400 * unregister_ftrace_function - unresgister a function for profiling.
1401 * @ops - ops structure that holds the function to unregister
1403 * Unregister a function that was added to be called by ftrace profiling.
1405 int unregister_ftrace_function(struct ftrace_ops *ops)
1409 mutex_lock(&ftrace_sysctl_lock);
1410 ret = __unregister_ftrace_function(ops);
1412 mutex_unlock(&ftrace_sysctl_lock);
1418 ftrace_enable_sysctl(struct ctl_table *table, int write,
1419 struct file *file, void __user *buffer, size_t *lenp,
1424 if (unlikely(ftrace_disabled))
1427 mutex_lock(&ftrace_sysctl_lock);
1429 ret = proc_dointvec(table, write, file, buffer, lenp, ppos);
1431 if (ret || !write || (last_ftrace_enabled == ftrace_enabled))
1434 last_ftrace_enabled = ftrace_enabled;
1436 if (ftrace_enabled) {
1438 ftrace_startup_sysctl();
1440 /* we are starting ftrace again */
1441 if (ftrace_list != &ftrace_list_end) {
1442 if (ftrace_list->next == &ftrace_list_end)
1443 ftrace_trace_function = ftrace_list->func;
1445 ftrace_trace_function = ftrace_list_func;
1449 /* stopping ftrace calls (just send to ftrace_stub) */
1450 ftrace_trace_function = ftrace_stub;
1452 ftrace_shutdown_sysctl();
1456 mutex_unlock(&ftrace_sysctl_lock);