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

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
......@@ -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");
......
......@@ -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",
pp->args[i]);
if (ret <= 0 || ret >= MAX_CMDLEN - len)
ret = e_snprintf(&buf[len], MAX_CMDLEN - len, " %s",
pp->args[i]);
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;
......
......@@ -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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