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perf probe: Allow wildcard for cached events

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Allo glob wildcard for reusing cached/SDT events. E.g.

  # perf probe -x /usr/lib64/libc-2.20.so -a %sdt_libc:\*

This example adds probes for all SDT in libc.
Note that the SDTs must have been scanned by perf buildid-cache.

Committer note:

Using it to check what of those SDT probes would take place when doing
a cargo run (rust):

  # trace --no-sys --event sdt_libc:* cargo run
     0.000 sdt_libc:setjmp:(7f326b69c4d1))
    28.423 sdt_libc:setjmp:(7f4b0a5364d1))
    29.000 sdt_libc:setjmp:(7f4b0a5364d1))
    88.597 sdt_libc:setjmp:(7fc01fd414d1))
    89.220 sdt_libc:setjmp:(7fc01fd414d1))
    95.501 sdt_libc:setjmp:(7f326b69c4d1))
     Running `target/debug/hello_world`
    97.110 sdt_libc:setjmp:(7f95e09234d1))
  Hello, world!
  #

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/146831791813.17065.17846564230840594888.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Masami Hiramatsu 2016-07-12 19:05:18 +09:00 committed by Arnaldo Carvalho de Melo
parent 05bf2c8a2a
commit 42bba263eb
3 changed files with 138 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

107
tools/perf/util/probe-event.c
View File

@ -1204,7 +1204,7 @@ static int parse_perf_probe_event_name(char **arg, struct perf_probe_event *pev)
ptr = strchr(*arg, ':');
if (ptr) {
*ptr = '\0';
if (!is_c_func_name(*arg))
if (!pev->sdt && !is_c_func_name(*arg))
goto ng_name;
pev->group = strdup(*arg);
if (!pev->group)
@ -1212,7 +1212,7 @@ static int parse_perf_probe_event_name(char **arg, struct perf_probe_event *pev)
*arg = ptr + 1;
} else
pev->group = NULL;
if (!is_c_func_name(*arg)) {
if (!pev->sdt && !is_c_func_name(*arg)) {
ng_name:
semantic_error("%s is bad for event name -it must "
"follow C symbol-naming rule.\n", *arg);
@ -1644,6 +1644,7 @@ int parse_probe_trace_command(const char *cmd, struct probe_trace_event *tev)
ret = -ENOMEM;
goto out;
}
tev->uprobes = (tp->module[0] == '/');
p++;
} else
p = argv[1];
@ -2518,7 +2519,7 @@ static int probe_trace_event__set_name(struct probe_trace_event *tev,
int ret;
/* If probe_event or trace_event already have the name, reuse it */
if (pev->event)
if (pev->event && !pev->sdt)
event = pev->event;
else if (tev->event)
event = tev->event;
@ -2531,7 +2532,7 @@ static int probe_trace_event__set_name(struct probe_trace_event *tev,
else
event = tev->point.realname;
}
if (pev->group)
if (pev->group && !pev->sdt)
group = pev->group;
else if (tev->group)
group = tev->group;
@ -2894,6 +2895,100 @@ errout:
bool __weak arch__prefers_symtab(void) { return false; }
/* Concatinate two arrays */
static void *memcat(void *a, size_t sz_a, void *b, size_t sz_b)
{
void *ret;
ret = malloc(sz_a + sz_b);
if (ret) {
memcpy(ret, a, sz_a);
memcpy(ret + sz_a, b, sz_b);
}
return ret;
}
static int
concat_probe_trace_events(struct probe_trace_event **tevs, int *ntevs,
struct probe_trace_event **tevs2, int ntevs2)
{
struct probe_trace_event *new_tevs;
int ret = 0;
if (ntevs == 0) {
*tevs = *tevs2;
*ntevs = ntevs2;
*tevs2 = NULL;
return 0;
}
if (*ntevs + ntevs2 > probe_conf.max_probes)
ret = -E2BIG;
else {
/* Concatinate the array of probe_trace_event */
new_tevs = memcat(*tevs, (*ntevs) * sizeof(**tevs),
*tevs2, ntevs2 * sizeof(**tevs2));
if (!new_tevs)
ret = -ENOMEM;
else {
free(*tevs);
*tevs = new_tevs;
*ntevs += ntevs2;
}
}
if (ret < 0)
clear_probe_trace_events(*tevs2, ntevs2);
zfree(tevs2);
return ret;
}
/*
* Try to find probe_trace_event from given probe caches. Return the number
* of cached events found, if an error occurs return the error.
*/
static int find_cached_events(struct perf_probe_event *pev,
struct probe_trace_event **tevs,
const char *target)
{
struct probe_cache *cache;
struct probe_cache_entry *entry;
struct probe_trace_event *tmp_tevs = NULL;
int ntevs = 0;
int ret = 0;
cache = probe_cache__new(target);
/* Return 0 ("not found") if the target has no probe cache. */
if (!cache)
return 0;
for_each_probe_cache_entry(entry, cache) {
/* Skip the cache entry which has no name */
if (!entry->pev.event || !entry->pev.group)
continue;
if ((!pev->group || strglobmatch(entry->pev.group, pev->group)) &&
strglobmatch(entry->pev.event, pev->event)) {
ret = probe_cache_entry__get_event(entry, &tmp_tevs);
if (ret > 0)
ret = concat_probe_trace_events(tevs, &ntevs,
&tmp_tevs, ret);
if (ret < 0)
break;
}
}
probe_cache__delete(cache);
if (ret < 0) {
clear_probe_trace_events(*tevs, ntevs);
zfree(tevs);
} else {
ret = ntevs;
if (ntevs > 0 && target && target[0] == '/')
pev->uprobes = true;
}
return ret;
}
static int find_probe_trace_events_from_cache(struct perf_probe_event *pev,
struct probe_trace_event **tevs)
{
@ -2903,6 +2998,10 @@ static int find_probe_trace_events_from_cache(struct perf_probe_event *pev,
struct str_node *node;
int ret, i;
if (pev->sdt)
/* For SDT/cached events, we use special search functions */
return find_cached_events(pev, tevs, pev->target);
cache = probe_cache__new(pev->target);
if (!cache)
return 0;

38
tools/perf/util/probe-file.c
View File

@ -362,13 +362,38 @@ probe_cache_entry__new(struct perf_probe_event *pev)
return entry;
}
/* For the kernel probe caches, pass target = NULL */
int probe_cache_entry__get_event(struct probe_cache_entry *entry,
struct probe_trace_event **tevs)
{
struct probe_trace_event *tev;
struct str_node *node;
int ret, i;
ret = strlist__nr_entries(entry->tevlist);
if (ret > probe_conf.max_probes)
return -E2BIG;
*tevs = zalloc(ret * sizeof(*tev));
if (!*tevs)
return -ENOMEM;
i = 0;
strlist__for_each_entry(node, entry->tevlist) {
tev = &(*tevs)[i++];
ret = parse_probe_trace_command(node->s, tev);
if (ret < 0)
break;
}
return i;
}
/* For the kernel probe caches, pass target = NULL or DSO__NAME_KALLSYMS */
static int probe_cache__open(struct probe_cache *pcache, const char *target)
{
char cpath[PATH_MAX];
char sbuildid[SBUILD_ID_SIZE];
char *dir_name = NULL;
bool is_kallsyms = !target;
bool is_kallsyms = false;
int ret, fd;
if (target && build_id_cache__cached(target)) {
@ -378,12 +403,13 @@ static int probe_cache__open(struct probe_cache *pcache, const char *target)
goto found;
}
if (target)
ret = filename__sprintf_build_id(target, sbuildid);
else {
if (!target || !strcmp(target, DSO__NAME_KALLSYMS)) {
target = DSO__NAME_KALLSYMS;
is_kallsyms = true;
ret = sysfs__sprintf_build_id("/", sbuildid);
}
} else
ret = filename__sprintf_build_id(target, sbuildid);
if (ret < 0) {
pr_debug("Failed to get build-id from %s.\n", target);
return ret;

3
tools/perf/util/probe-file.h
View File

@ -34,6 +34,9 @@ int probe_file__get_events(int fd, struct strfilter *filter,
struct strlist *plist);
int probe_file__del_strlist(int fd, struct strlist *namelist);
int probe_cache_entry__get_event(struct probe_cache_entry *entry,
struct probe_trace_event **tevs);
struct probe_cache *probe_cache__new(const char *target);
int probe_cache__add_entry(struct probe_cache *pcache,
struct perf_probe_event *pev,