[PATCH perf/core v11 09/20] perf probe: Show all cached probes

Masami Hiramatsu
2016-06-15T03:29:13Z

From: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>

perf probe --list shows all cached probes when --cache
is given. Each caches are shown with on which binary that
probed. e.g.
-----
# perf probe --cache vfs_read \$params
# perf probe --cache -x /lib64/libc-2.17.so getaddrinfo \$params
# perf probe --cache --list
[kernel.kallsyms] (1466a0a250b5d0070c6d0f03c5fed30b237970a1):
vfs_read $params
/usr/lib64/libc-2.17.so (c31ffe7942bfd77b2fca8f9bd5709d387a86d3bc):
getaddrinfo $params
-----
Note that $params requires debuginfo.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
Changes in v11:
- Make build_id_cache__list_all() returns strlist directly. (no error code)
- Harden build_id_cache__list_all() to check directory entries.
Changes in v7:
- Remove the top '/' from binary name if it is not a regular file.
---
tools/perf/Documentation/perf-probe.txt | 8 ++
tools/perf/builtin-probe.c | 2 -
tools/perf/util/build-id.c | 108 ++++++++++++++++++++++++++++++-
tools/perf/util/build-id.h | 3 +
tools/perf/util/probe-event.c | 3 +
tools/perf/util/probe-file.c | 66 ++++++++++++++++++-
tools/perf/util/probe-file.h | 1
7 files changed, 184 insertions(+), 7 deletions(-)

diff --git a/tools/perf/Documentation/perf-probe.txt b/tools/perf/Documentation/perf-probe.txt
index 947db6f..5a70d45 100644
--- a/tools/perf/Documentation/perf-probe.txt
+++ b/tools/perf/Documentation/perf-probe.txt
@@ -67,7 +67,10 @@ OPTIONS

-l::
--list[=[GROUP:]EVENT]::
- List up current probe events. This can also accept filtering patterns of event names.
+ List up current probe events. This can also accept filtering patterns of
+ event names.
+ When this is used with --cache, perf shows all cached probes instead of
+ the live probes.

-L::
--line=::
@@ -110,8 +113,9 @@ OPTIONS
adding and removal operations.

--cache::
- Cache the probes (with --add option). Any events which successfully added
+ (With --add) Cache the probes. Any events which successfully added
are also stored in the cache file.
+ (With --list) Show cached probes.

--max-probes=NUM::
Set the maximum number of probe points for an event. Default is 128.
diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
index 6d7ab431..53e380c0e 100644
--- a/tools/perf/builtin-probe.c
+++ b/tools/perf/builtin-probe.c
@@ -44,7 +44,7 @@

#define DEFAULT_VAR_FILTER "!__k???tab_* & !__crc_*"
#define DEFAULT_FUNC_FILTER "!_*"
-#define DEFAULT_LIST_FILTER "*:*"
+#define DEFAULT_LIST_FILTER "*"

/* Session management structure */
static struct {
diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index 62b1473..0d6093c 100644
--- a/tools/perf/util/build-id.c
+++ b/tools/perf/util/build-id.c
@@ -165,8 +165,7 @@ retry:
return NULL;
}

-static char *build_id_cache__linkname(const char *sbuild_id, char *bf,
- size_t size)
+char *build_id_cache__linkname(const char *sbuild_id, char *bf, size_t size)
{
char *tmp = bf;
int ret = asnprintf(&bf, size, "%s/.build-id/%.2s/%s", buildid_dir,
@@ -176,6 +175,36 @@ static char *build_id_cache__linkname(const char *sbuild_id, char *bf,
return bf;
}

+char *build_id_cache__origname(const char *sbuild_id)
+{
+ char *linkname;
+ char buf[PATH_MAX];
+ char *ret = NULL, *p;
+ size_t offs = 5; /* == strlen("../..") */
+
+ linkname = build_id_cache__linkname(sbuild_id, NULL, 0);
+ if (!linkname)
+ return NULL;
+
+ if (readlink(linkname, buf, PATH_MAX) < 0)
+ goto out;
+ /* The link should be "../..<origpath>/<sbuild_id>" */
+ p = strrchr(buf, '/'); /* Cut off the "/<sbuild_id>" */
+ if (p && (p > buf + offs)) {
+ *p = '\0';
+ if (buf[offs + 1] == '[')
+ offs++; /*
+ * This is a DSO name, like [kernel.kallsyms].
+ * Skip the first '/', since this is not the
+ * cache of a regular file.
+ */
+ ret = strdup(buf + offs); /* Skip "../..[/]" */
+ }
+out:
+ free(linkname);
+ return ret;
+}
+
static const char *build_id_cache__basename(bool is_kallsyms, bool is_vdso)
{
return is_kallsyms ? "kallsyms" : (is_vdso ? "vdso" : "elf");
@@ -387,6 +416,81 @@ void disable_buildid_cache(void)
no_buildid_cache = true;
}

+static bool lsdir_bid_head_filter(const char *name __maybe_unused,
+ struct dirent *d __maybe_unused)
+{
+ return (strlen(d->d_name) == 2) &&
+ isxdigit(d->d_name[0]) && isxdigit(d->d_name[1]);
+}
+
+static bool lsdir_bid_tail_filter(const char *name __maybe_unused,
+ struct dirent *d __maybe_unused)
+{
+ int i = 0;
+ while (isxdigit(d->d_name[i]) && i < SBUILD_ID_SIZE - 3)
+ i++;
+ return (i == SBUILD_ID_SIZE - 3) && (d->d_name[i] == '\0');
+}
+
+struct strlist *build_id_cache__list_all(void)
+{
+ struct strlist *toplist, *linklist = NULL, *bidlist;
+ struct str_node *nd, *nd2;
+ char *topdir, *linkdir = NULL;
+ char sbuild_id[SBUILD_ID_SIZE];
+
+ /* Open the top-level directory */
+ if (asprintf(&topdir, "%s/.build-id/", buildid_dir) < 0)
+ return NULL;
+
+ bidlist = strlist__new(NULL, NULL);
+ if (!bidlist)
+ goto out;
+
+ toplist = lsdir(topdir, lsdir_bid_head_filter);
+ if (!toplist) {
+ pr_debug("Error in lsdir(%s): %d\n", topdir, errno);
+ /* If there is no buildid cache, return an empty list */
+ if (errno == ENOENT)
+ goto out;
+ goto err_out;
+ }
+
+ strlist__for_each(nd, toplist) {
+ if (asprintf(&linkdir, "%s/%s", topdir, nd->s) < 0)
+ goto err_out;
+ /* Open the lower-level directory */
+ linklist = lsdir(linkdir, lsdir_bid_tail_filter);
+ if (!linklist) {
+ pr_debug("Error in lsdir(%s): %d\n", linkdir, errno);
+ goto err_out;
+ }
+ strlist__for_each(nd2, linklist) {
+ if (snprintf(sbuild_id, SBUILD_ID_SIZE, "%s%s",
+ nd->s, nd2->s) != SBUILD_ID_SIZE - 1)
+ goto err_out;
+ if (strlist__add(bidlist, sbuild_id) < 0)
+ goto err_out;
+ }
+ strlist__delete(linklist);
+ zfree(&linkdir);
+ }
+
+out_free:
+ strlist__delete(toplist);
+out:
+ free(topdir);
+
+ return bidlist;
+
+err_out:
+ strlist__delete(linklist);
+ zfree(&linkdir);
+ strlist__delete(bidlist);
+ bidlist = NULL;
+ goto out_free;
+}
+
char *build_id_cache__cachedir(const char *sbuild_id, const char *name,
bool is_kallsyms, bool is_vdso)
{
diff --git a/tools/perf/util/build-id.h b/tools/perf/util/build-id.h
index d8c7f2f..b742e27 100644
--- a/tools/perf/util/build-id.h
+++ b/tools/perf/util/build-id.h
@@ -30,8 +30,11 @@ bool perf_session__read_build_ids(struct perf_session *session, bool with_hits);
int perf_session__write_buildid_table(struct perf_session *session, int fd);
int perf_session__cache_build_ids(struct perf_session *session);

+char *build_id_cache__origname(const char *sbuild_id);
+char *build_id_cache__linkname(const char *sbuild_id, char *bf, size_t size);
char *build_id_cache__cachedir(const char *sbuild_id, const char *name,
bool is_kallsyms, bool is_vdso);
+struct strlist *build_id_cache__list_all(void);
int build_id_cache__list_build_ids(const char *pathname,
struct strlist **result);
bool build_id_cache__cached(const char *sbuild_id);
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 020c110..fbb101d 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -2368,6 +2368,9 @@ int show_perf_probe_events(struct strfilter *filter)

setup_pager();

+ if (probe_conf.cache)
+ return probe_cache__show_all_caches(filter);
+
ret = init_probe_symbol_maps(false);
if (ret < 0)
return ret;
diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c
index 58a60b3..47e0e95 100644
--- a/tools/perf/util/probe-file.c
+++ b/tools/perf/util/probe-file.c
@@ -367,10 +367,17 @@ static int probe_cache__open(struct probe_cache *pcache, const char *target)
{
char cpath[PATH_MAX];
char sbuildid[SBUILD_ID_SIZE];
- char *dir_name;
+ char *dir_name = NULL;
bool is_kallsyms = !target;
int ret, fd;

+ if (target && build_id_cache__cached(target)) {
+ /* This is a cached buildid */
+ strncpy(sbuildid, target, SBUILD_ID_SIZE);
+ dir_name = build_id_cache__linkname(sbuildid, NULL, 0);
+ goto found;
+ }
+
if (target)
ret = filename__sprintf_build_id(target, sbuildid);
else {
@@ -394,8 +401,11 @@ static int probe_cache__open(struct probe_cache *pcache, const char *target)

dir_name = build_id_cache__cachedir(sbuildid, target, is_kallsyms,
false);
- if (!dir_name)
+found:
+ if (!dir_name) {
+ pr_debug("Failed to get cache from %s\n", target);
return -ENOMEM;
+ }

snprintf(cpath, PATH_MAX, "%s/probes", dir_name);
fd = open(cpath, O_CREAT | O_RDWR, 0644);
@@ -673,3 +683,55 @@ int probe_cache__commit(struct probe_cache *pcache)
out:
return ret;
}
+
+static int probe_cache__show_entries(struct probe_cache *pcache,
+ struct strfilter *filter)
+{
+ struct probe_cache_entry *entry;
+ char buf[128], *ptr;
+
+ list_for_each_entry(entry, &pcache->entries, node) {
+ if (entry->pev.event) {
+ ptr = buf;
+ snprintf(buf, 128, "%s:%s",
+ entry->pev.group, entry->pev.event);
+ } else
+ ptr = entry->spev;
+ if (strfilter__compare(filter, ptr))
+ printf("%s\n", entry->spev);
+ }
+ return 0;
+}
+
+/* Show all cached probes */
+int probe_cache__show_all_caches(struct strfilter *filter)
+{
+ struct probe_cache *pcache;
+ struct strlist *bidlist;
+ struct str_node *nd;
+ char *buf = strfilter__string(filter);
+
+ pr_debug("list cache with filter: %s\n", buf);
+ free(buf);
+
+ bidlist = build_id_cache__list_all();
+ if (!bidlist) {
+ pr_debug("Failed to get buildids: %d\n", errno);
+ return -EINVAL;
+ }
+ strlist__for_each(nd, bidlist) {
+ pcache = probe_cache__new(nd->s);
+ if (!pcache)
+ continue;
+ if (!list_empty(&pcache->entries)) {
+ buf = build_id_cache__origname(nd->s);
+ printf("%s (%s):\n", buf, nd->s);
+ free(buf);
+ probe_cache__show_entries(pcache, filter);
+ }
+ probe_cache__delete(pcache);
+ }
+ strlist__delete(bidlist);
+
+ return 0;
+}
diff --git a/tools/perf/util/probe-file.h b/tools/perf/util/probe-file.h
index 910aa74..0009b8a 100644
--- a/tools/perf/util/probe-file.h
+++ b/tools/perf/util/probe-file.h
@@ -42,4 +42,5 @@ struct probe_cache_entry *probe_cache__find(struct probe_cache *pcache,
struct perf_probe_event *pev);
struct probe_cache_entry *probe_cache__find_by_name(struct probe_cache *pcache,
const char *group, const char *event);
+int probe_cache__show_all_caches(struct strfilter *filter);
#endif