Commit 4de189fe authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Ingo Molnar
Browse files

perf probe: Add --list option for listing current probe events 



Add --list option for listing currently defined probe events
in the kernel. This shows events in below format;

 [group:event]	<perf-probe probe-definition>

for example:

 [probe:schedule_0]	schedule+30 cpu

Note that source file/line information is not supported yet.
So even if you added a probe by line, it will be shown in
<symbol+offset>.

Signed-off-by: default avatarMasami Hiramatsu <mhiramat@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091201002017.10235.76575.stgit@harusame>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent e1c01d61

tools/perf/builtin-probe.c

+11 −1
Original line number Diff line number Diff line
@@ -62,6 +62,8 @@ static struct { 
	struct probe_point probes[MAX_PROBES];

} session;



static bool listing;



/* Parse an event definition. Note that any error must die. */

static void parse_probe_event(const char *str)

{
@@ -119,6 +121,7 @@ static int open_default_vmlinux(void) 
static const char * const probe_usage[] = {

	"perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",

	"perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",

	"perf probe --list",

	NULL

};
@@ -129,6 +132,7 @@ static const struct option options[] = { 
	OPT_STRING('k', "vmlinux", &session.vmlinux, "file",

		"vmlinux/module pathname"),

#endif

	OPT_BOOLEAN('l', "list", &listing, "list up current probes"),

	OPT_CALLBACK('a', "add", NULL,

#ifdef NO_LIBDWARF

		"FUNC[+OFFS|%return] [ARG ...]",
@@ -164,9 +168,15 @@ int cmd_probe(int argc, const char **argv, const char *prefix __used) 
	for (i = 0; i < argc; i++)

		parse_probe_event(argv[i]);



	if (session.nr_probe == 0)

	if ((session.nr_probe == 0 && !listing) ||

	    (session.nr_probe != 0 && listing))

		usage_with_options(probe_usage, options);



	if (listing) {

		show_perf_probe_events();

		return 0;

	}



	if (session.need_dwarf)

#ifdef NO_LIBDWARF

		die("Debuginfo-analysis is not supported");

tools/perf/util/probe-event.c

+214 −17
Original line number Diff line number Diff line
@@ -29,10 +29,13 @@ 
#include <unistd.h>

#include <stdlib.h>

#include <string.h>

#include <stdarg.h>

#include <limits.h>



#undef _GNU_SOURCE

#include "event.h"

#include "string.h"

#include "strlist.h"

#include "debug.h"

#include "parse-events.h"  /* For debugfs_path */

#include "probe-event.h"
@@ -43,6 +46,19 @@ 


#define semantic_error(msg ...) die("Semantic error :" msg)



/* If there is no space to write, returns -E2BIG. */

static int e_snprintf(char *str, size_t size, const char *format, ...)

{

	int ret;

	va_list ap;

	va_start(ap, format);

	ret = vsnprintf(str, size, format, ap);

	va_end(ap);

	if (ret >= (int)size)

		ret = -E2BIG;

	return ret;

}



/* Parse probepoint definition. */

static void parse_perf_probe_probepoint(char *arg, struct probe_point *pp)

{
@@ -166,6 +182,103 @@ int parse_perf_probe_event(const char *str, struct probe_point *pp) 
	return need_dwarf;

}



/* Parse kprobe_events event into struct probe_point */

void parse_trace_kprobe_event(const char *str, char **group, char **event,

			      struct probe_point *pp)

{

	char pr;

	char *p;

	int ret, i, argc;

	char **argv;



	pr_debug("Parsing kprobe_events: %s\n", str);

	argv = argv_split(str, &argc);

	if (!argv)

		die("argv_split failed.");

	if (argc < 2)

		semantic_error("Too less arguments.");



	/* Scan event and group name. */

	ret = sscanf(argv[0], "%c:%m[^/ \t]/%m[^ \t]",

		     &pr, group, event);

	if (ret != 3)

		semantic_error("Failed to parse event name: %s", argv[0]);

	pr_debug("Group:%s Event:%s probe:%c\n", *group, *event, pr);



	if (!pp)

		goto end;



	pp->retprobe = (pr == 'r');



	/* Scan function name and offset */

	ret = sscanf(argv[1], "%m[^+]+%d", &pp->function, &pp->offset);

	if (ret == 1)

		pp->offset = 0;



	/* kprobe_events doesn't have this information */

	pp->line = 0;

	pp->file = NULL;



	pp->nr_args = argc - 2;

	pp->args = zalloc(sizeof(char *) * pp->nr_args);

	for (i = 0; i < pp->nr_args; i++) {

		p = strchr(argv[i + 2], '=');

		if (p)	/* We don't need which register is assigned. */

			*p = '\0';

		pp->args[i] = strdup(argv[i + 2]);

		if (!pp->args[i])

			die("Failed to copy argument.");

	}



end:

	argv_free(argv);

}



int synthesize_perf_probe_event(struct probe_point *pp)

{

	char *buf;

	char offs[64] = "", line[64] = "";

	int i, len, ret;



	pp->probes[0] = buf = zalloc(MAX_CMDLEN);

	if (!buf)

		die("Failed to allocate memory by zalloc.");

	if (pp->offset) {

		ret = e_snprintf(offs, 64, "+%d", pp->offset);

		if (ret <= 0)

			goto error;

	}

	if (pp->line) {

		ret = e_snprintf(line, 64, ":%d", pp->line);

		if (ret <= 0)

			goto error;

	}



	if (pp->function)

		ret = e_snprintf(buf, MAX_CMDLEN, "%s%s%s%s", pp->function,

				 offs, pp->retprobe ? "%return" : "", line);

	else

		ret = e_snprintf(buf, MAX_CMDLEN, "%s%s%s%s", pp->file, line);

	if (ret <= 0)

		goto error;

	len = ret;



	for (i = 0; i < pp->nr_args; i++) {

		ret = e_snprintf(&buf[len], MAX_CMDLEN - len, " %s",

				 pp->args[i]);

		if (ret <= 0)

			goto error;

		len += ret;

	}

	pp->found = 1;



	return pp->found;

error:

	free(pp->probes[0]);



	return ret;

}



int synthesize_trace_kprobe_event(struct probe_point *pp)

{

	char *buf;
@@ -174,15 +287,15 @@ int synthesize_trace_kprobe_event(struct probe_point *pp) 
	pp->probes[0] = buf = zalloc(MAX_CMDLEN);

	if (!buf)

		die("Failed to allocate memory by zalloc.");

	ret = snprintf(buf, MAX_CMDLEN, "%s+%d", pp->function, pp->offset);

	if (ret <= 0 || ret >= MAX_CMDLEN)

	ret = e_snprintf(buf, MAX_CMDLEN, "%s+%d", pp->function, pp->offset);

	if (ret <= 0)

		goto error;

	len = ret;



	for (i = 0; i < pp->nr_args; i++) {

		ret = snprintf(&buf[len], MAX_CMDLEN - len, " %s",

		ret = e_snprintf(&buf[len], MAX_CMDLEN - len, " %s",

				 pp->args[i]);

		if (ret <= 0 || ret >= MAX_CMDLEN - len)

		if (ret <= 0)

			goto error;

		len += ret;

	}
@@ -191,12 +304,105 @@ int synthesize_trace_kprobe_event(struct probe_point *pp) 
	return pp->found;

error:

	free(pp->probes[0]);

	if (ret > 0)

		ret = -E2BIG;



	return ret;

}



static int open_kprobe_events(int flags, int mode)

{

	char buf[PATH_MAX];

	int ret;



	ret = e_snprintf(buf, PATH_MAX, "%s/../kprobe_events", debugfs_path);

	if (ret < 0)

		die("Failed to make kprobe_events path.");



	ret = open(buf, flags, mode);

	if (ret < 0) {

		if (errno == ENOENT)

			die("kprobe_events file does not exist -"

			    " please rebuild with CONFIG_KPROBE_TRACER.");

		else

			die("Could not open kprobe_events file: %s",

			    strerror(errno));

	}

	return ret;

}



/* Get raw string list of current kprobe_events */

static struct strlist *get_trace_kprobe_event_rawlist(int fd)

{

	int ret, idx;

	FILE *fp;

	char buf[MAX_CMDLEN];

	char *p;

	struct strlist *sl;



	sl = strlist__new(true, NULL);



	fp = fdopen(dup(fd), "r");

	while (!feof(fp)) {

		p = fgets(buf, MAX_CMDLEN, fp);

		if (!p)

			break;



		idx = strlen(p) - 1;

		if (p[idx] == '\n')

			p[idx] = '\0';

		ret = strlist__add(sl, buf);

		if (ret < 0)

			die("strlist__add failed: %s", strerror(-ret));

	}

	fclose(fp);



	return sl;

}



/* Free and zero clear probe_point */

static void clear_probe_point(struct probe_point *pp)

{

	int i;



	if (pp->function)

		free(pp->function);

	if (pp->file)

		free(pp->file);

	for (i = 0; i < pp->nr_args; i++)

		free(pp->args[i]);

	if (pp->args)

		free(pp->args);

	for (i = 0; i < pp->found; i++)

		free(pp->probes[i]);

	memset(pp, 0, sizeof(pp));

}



/* List up current perf-probe events */

void show_perf_probe_events(void)

{

	unsigned int i;

	int fd;

	char *group, *event;

	struct probe_point pp;

	struct strlist *rawlist;

	struct str_node *ent;



	fd = open_kprobe_events(O_RDONLY, 0);

	rawlist = get_trace_kprobe_event_rawlist(fd);

	close(fd);



	for (i = 0; i < strlist__nr_entries(rawlist); i++) {

		ent = strlist__entry(rawlist, i);

		parse_trace_kprobe_event(ent->s, &group, &event, &pp);

		synthesize_perf_probe_event(&pp);

		printf("[%s:%s]\t%s\n", group, event, pp.probes[0]);

		free(group);

		free(event);

		clear_probe_point(&pp);

	}



	strlist__delete(rawlist);

}



static int write_trace_kprobe_event(int fd, const char *buf)

{

	int ret;
@@ -216,16 +422,7 @@ void add_trace_kprobe_events(struct probe_point *probes, int nr_probes) 
	struct probe_point *pp;

	char buf[MAX_CMDLEN];



	snprintf(buf, MAX_CMDLEN, "%s/../kprobe_events", debugfs_path);

	fd = open(buf, O_WRONLY, O_APPEND);

	if (fd < 0) {

		if (errno == ENOENT)

			die("kprobe_events file does not exist -"

			    " please rebuild with CONFIG_KPROBE_TRACER.");

		else

			die("Could not open kprobe_events file: %s",

			    strerror(errno));

	}

	fd = open_kprobe_events(O_WRONLY, O_APPEND);



	for (j = 0; j < nr_probes; j++) {

		pp = probes + j;

tools/perf/util/probe-event.h

+5 −0
Original line number Diff line number Diff line
@@ -2,9 +2,14 @@ 
#define _PROBE_EVENT_H



#include "probe-finder.h"

#include "strlist.h"



extern int parse_perf_probe_event(const char *str, struct probe_point *pp);

extern int synthesize_perf_probe_event(struct probe_point *pp);

extern void parse_trace_kprobe_event(const char *str, char **group,

				     char **event, struct probe_point *pp);

extern int synthesize_trace_kprobe_event(struct probe_point *pp);

extern void add_trace_kprobe_events(struct probe_point *probes, int nr_probes);

extern void show_perf_probe_events(void);



#endif /*_PROBE_EVENT_H */

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