2 * probe-event.c : perf-probe definition to kprobe_events format converter
4 * Written by Masami Hiramatsu <mhiramat@redhat.com>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
23 #include <sys/utsname.h>
24 #include <sys/types.h>
40 #include "parse-events.h" /* For debugfs_path */
41 #include "probe-event.h"
43 #define MAX_CMDLEN 256
44 #define MAX_PROBE_ARGS 128
45 #define PERFPROBE_GROUP "probe"
47 #define semantic_error(msg ...) die("Semantic error :" msg)
49 /* If there is no space to write, returns -E2BIG. */
50 static int e_snprintf(char *str
, size_t size
, const char *format
, ...)
51 __attribute__((format(printf
, 3, 4)));
53 static int e_snprintf(char *str
, size_t size
, const char *format
, ...)
58 ret
= vsnprintf(str
, size
, format
, ap
);
65 /* Parse probepoint definition. */
66 static void parse_perf_probe_probepoint(char *arg
, struct probe_point
*pp
)
73 * perf probe FUNC[+OFFS|%return][@SRC]
76 ptr
= strpbrk(arg
, ":+@%");
82 /* Check arg is function or file and copy it */
83 if (strchr(arg
, '.')) /* File */
84 pp
->file
= strdup(arg
);
86 pp
->function
= strdup(arg
);
87 DIE_IF(pp
->file
== NULL
&& pp
->function
== NULL
);
89 /* Parse other options */
93 ptr
= strpbrk(arg
, ":+@%");
99 case ':': /* Line number */
100 pp
->line
= strtoul(arg
, &tmp
, 0);
102 semantic_error("There is non-digit charactor"
105 case '+': /* Byte offset from a symbol */
106 pp
->offset
= strtoul(arg
, &tmp
, 0);
108 semantic_error("There is non-digit charactor"
111 case '@': /* File name */
113 semantic_error("SRC@SRC is not allowed.");
114 pp
->file
= strdup(arg
);
115 DIE_IF(pp
->file
== NULL
);
117 semantic_error("@SRC must be the last "
120 case '%': /* Probe places */
121 if (strcmp(arg
, "return") == 0) {
123 } else /* Others not supported yet */
124 semantic_error("%%%s is not supported.", arg
);
127 DIE_IF("Program has a bug.");
132 /* Exclusion check */
133 if (pp
->line
&& pp
->offset
)
134 semantic_error("Offset can't be used with line number.");
136 if (!pp
->line
&& pp
->file
&& !pp
->function
)
137 semantic_error("File always requires line number.");
139 if (pp
->offset
&& !pp
->function
)
140 semantic_error("Offset requires an entry function.");
142 if (pp
->retprobe
&& !pp
->function
)
143 semantic_error("Return probe requires an entry function.");
145 if ((pp
->offset
|| pp
->line
) && pp
->retprobe
)
146 semantic_error("Offset/Line can't be used with return probe.");
148 pr_debug("symbol:%s file:%s line:%d offset:%d, return:%d\n",
149 pp
->function
, pp
->file
, pp
->line
, pp
->offset
, pp
->retprobe
);
152 /* Parse perf-probe event definition */
153 int parse_perf_probe_event(const char *str
, struct probe_point
*pp
)
156 int argc
, i
, need_dwarf
= 0;
158 argv
= argv_split(str
, &argc
);
160 die("argv_split failed.");
161 if (argc
> MAX_PROBE_ARGS
+ 1)
162 semantic_error("Too many arguments");
164 /* Parse probe point */
165 parse_perf_probe_probepoint(argv
[0], pp
);
166 if (pp
->file
|| pp
->line
)
169 /* Copy arguments and ensure return probe has no C argument */
170 pp
->nr_args
= argc
- 1;
171 pp
->args
= zalloc(sizeof(char *) * pp
->nr_args
);
172 for (i
= 0; i
< pp
->nr_args
; i
++) {
173 pp
->args
[i
] = strdup(argv
[i
+ 1]);
175 die("Failed to copy argument.");
176 if (is_c_varname(pp
->args
[i
])) {
178 semantic_error("You can't specify local"
179 " variable for kretprobe");
188 /* Parse kprobe_events event into struct probe_point */
189 void parse_trace_kprobe_event(const char *str
, char **group
, char **event
,
190 struct probe_point
*pp
)
197 pr_debug("Parsing kprobe_events: %s\n", str
);
198 argv
= argv_split(str
, &argc
);
200 die("argv_split failed.");
202 semantic_error("Too less arguments.");
204 /* Scan event and group name. */
205 ret
= sscanf(argv
[0], "%c:%a[^/ \t]/%a[^ \t]",
206 &pr
, (float *)(void *)group
, (float *)(void *)event
);
208 semantic_error("Failed to parse event name: %s", argv
[0]);
209 pr_debug("Group:%s Event:%s probe:%c\n", *group
, *event
, pr
);
214 pp
->retprobe
= (pr
== 'r');
216 /* Scan function name and offset */
217 ret
= sscanf(argv
[1], "%a[^+]+%d", (float *)(void *)&pp
->function
, &pp
->offset
);
221 /* kprobe_events doesn't have this information */
225 pp
->nr_args
= argc
- 2;
226 pp
->args
= zalloc(sizeof(char *) * pp
->nr_args
);
227 for (i
= 0; i
< pp
->nr_args
; i
++) {
228 p
= strchr(argv
[i
+ 2], '=');
229 if (p
) /* We don't need which register is assigned. */
231 pp
->args
[i
] = strdup(argv
[i
+ 2]);
233 die("Failed to copy argument.");
240 int synthesize_perf_probe_event(struct probe_point
*pp
)
243 char offs
[64] = "", line
[64] = "";
246 pp
->probes
[0] = buf
= zalloc(MAX_CMDLEN
);
248 die("Failed to allocate memory by zalloc.");
250 ret
= e_snprintf(offs
, 64, "+%d", pp
->offset
);
255 ret
= e_snprintf(line
, 64, ":%d", pp
->line
);
261 ret
= e_snprintf(buf
, MAX_CMDLEN
, "%s%s%s%s", pp
->function
,
262 offs
, pp
->retprobe
? "%return" : "", line
);
264 ret
= e_snprintf(buf
, MAX_CMDLEN
, "%s%s", pp
->file
, line
);
269 for (i
= 0; i
< pp
->nr_args
; i
++) {
270 ret
= e_snprintf(&buf
[len
], MAX_CMDLEN
- len
, " %s",
285 int synthesize_trace_kprobe_event(struct probe_point
*pp
)
290 pp
->probes
[0] = buf
= zalloc(MAX_CMDLEN
);
292 die("Failed to allocate memory by zalloc.");
293 ret
= e_snprintf(buf
, MAX_CMDLEN
, "%s+%d", pp
->function
, pp
->offset
);
298 for (i
= 0; i
< pp
->nr_args
; i
++) {
299 ret
= e_snprintf(&buf
[len
], MAX_CMDLEN
- len
, " %s",
314 static int open_kprobe_events(int flags
, int mode
)
319 ret
= e_snprintf(buf
, PATH_MAX
, "%s/../kprobe_events", debugfs_path
);
321 die("Failed to make kprobe_events path.");
323 ret
= open(buf
, flags
, mode
);
326 die("kprobe_events file does not exist -"
327 " please rebuild with CONFIG_KPROBE_TRACER.");
329 die("Could not open kprobe_events file: %s",
335 /* Get raw string list of current kprobe_events */
336 static struct strlist
*get_trace_kprobe_event_rawlist(int fd
)
340 char buf
[MAX_CMDLEN
];
344 sl
= strlist__new(true, NULL
);
346 fp
= fdopen(dup(fd
), "r");
348 p
= fgets(buf
, MAX_CMDLEN
, fp
);
355 ret
= strlist__add(sl
, buf
);
357 die("strlist__add failed: %s", strerror(-ret
));
364 /* Free and zero clear probe_point */
365 static void clear_probe_point(struct probe_point
*pp
)
373 for (i
= 0; i
< pp
->nr_args
; i
++)
377 for (i
= 0; i
< pp
->found
; i
++)
379 memset(pp
, 0, sizeof(pp
));
383 static void show_perf_probe_event(const char *group
, const char *event
,
384 const char *place
, struct probe_point
*pp
)
389 e_snprintf(buf
, 128, "%s:%s", group
, event
);
390 printf(" %-40s (on %s", buf
, place
);
392 if (pp
->nr_args
> 0) {
394 for (i
= 0; i
< pp
->nr_args
; i
++)
395 printf(" %s", pp
->args
[i
]);
400 /* List up current perf-probe events */
401 void show_perf_probe_events(void)
406 struct probe_point pp
;
407 struct strlist
*rawlist
;
408 struct str_node
*ent
;
410 fd
= open_kprobe_events(O_RDONLY
, 0);
411 rawlist
= get_trace_kprobe_event_rawlist(fd
);
414 for (i
= 0; i
< strlist__nr_entries(rawlist
); i
++) {
415 ent
= strlist__entry(rawlist
, i
);
416 parse_trace_kprobe_event(ent
->s
, &group
, &event
, &pp
);
417 /* Synthesize only event probe point */
420 synthesize_perf_probe_event(&pp
);
423 show_perf_probe_event(group
, event
, pp
.probes
[0], &pp
);
426 clear_probe_point(&pp
);
429 strlist__delete(rawlist
);
432 /* Get current perf-probe event names */
433 static struct strlist
*get_perf_event_names(int fd
)
437 struct strlist
*sl
, *rawlist
;
438 struct str_node
*ent
;
440 rawlist
= get_trace_kprobe_event_rawlist(fd
);
442 sl
= strlist__new(true, NULL
);
443 for (i
= 0; i
< strlist__nr_entries(rawlist
); i
++) {
444 ent
= strlist__entry(rawlist
, i
);
445 parse_trace_kprobe_event(ent
->s
, &group
, &event
, NULL
);
446 strlist__add(sl
, event
);
451 strlist__delete(rawlist
);
456 static void write_trace_kprobe_event(int fd
, const char *buf
)
460 ret
= write(fd
, buf
, strlen(buf
));
462 die("Failed to create event.");
465 static void get_new_event_name(char *buf
, size_t len
, const char *base
,
466 struct strlist
*namelist
)
471 ret
= e_snprintf(buf
, len
, "%s", base
);
473 die("snprintf() failed: %s", strerror(-ret
));
474 if (!strlist__has_entry(namelist
, buf
))
477 /* Try to add suffix */
478 for (i
= 1; i
< MAX_EVENT_INDEX
; i
++) {
479 ret
= e_snprintf(buf
, len
, "%s_%d", base
, i
);
481 die("snprintf() failed: %s", strerror(-ret
));
482 if (!strlist__has_entry(namelist
, buf
))
485 if (i
== MAX_EVENT_INDEX
)
486 die("Too many events are on the same function.");
489 void add_trace_kprobe_events(struct probe_point
*probes
, int nr_probes
)
492 struct probe_point
*pp
;
493 char buf
[MAX_CMDLEN
];
495 struct strlist
*namelist
;
497 fd
= open_kprobe_events(O_RDWR
, O_APPEND
);
498 /* Get current event names */
499 namelist
= get_perf_event_names(fd
);
501 for (j
= 0; j
< nr_probes
; j
++) {
503 for (i
= 0; i
< pp
->found
; i
++) {
504 /* Get an unused new event name */
505 get_new_event_name(event
, 64, pp
->function
, namelist
);
506 snprintf(buf
, MAX_CMDLEN
, "%c:%s/%s %s\n",
507 pp
->retprobe
? 'r' : 'p',
508 PERFPROBE_GROUP
, event
,
510 write_trace_kprobe_event(fd
, buf
);
511 printf("Added new event:\n");
512 /* Get the first parameter (probe-point) */
513 sscanf(pp
->probes
[i
], "%s", buf
);
514 show_perf_probe_event(PERFPROBE_GROUP
, event
,
516 /* Add added event name to namelist */
517 strlist__add(namelist
, event
);
520 /* Show how to use the event. */
521 printf("\nYou can now use it on all perf tools, such as:\n\n");
522 printf("\tperf record -e %s:%s -a sleep 1\n\n", PERFPROBE_GROUP
, event
);
524 strlist__delete(namelist
);
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