perf-probe --cache and SDT support

From: Masami Hiramatsu <[email protected]>

Make "perf probe --cache --list" shows only available cached events by checking build-id validity.

E.g. without this patch:
----

  $ ./perf probe --cache --add oldevent=cmd_probe
  $ make #(to update ./perf)
  $ ./perf probe --cache --add newevent=cmd_probe
  $ ./perf probe --cache --list
  /home/mhiramat/ksrc/linux/tools/perf/perf (061e90539bac69
  probe_perf:newevent=cmd_probe
  /home/mhiramat/ksrc/linux/tools/perf/perf (c2e44d614e33e1
  probe_perf:oldevent=cmd_probe
  ----
It shows both of old and new events but user can not use old one.
With this;
  ----
  $ ./perf probe --cache -l
  /home/mhiramat/ksrc/linux/tools/perf/perf (061e90539bac69
  probe_perf:newevent=cmd_probe
  ----
This show only new event which is on the existing binary.

Signed-off-by Masami Hiramatsu <[email protected]>

Signed-off-by Masami Hiramatsu <[email protected]>

---
Changes in v13:
- Instead of the perf-list, apply this change for perf-probe --list because of avoiding to confuse user.
Changes in v7:
- Validate build-id via sysfs if it is for kallsyms,
Changes in v4:
- Rename a parameter 'valid' to 'validonly' :)

---
 tools/perf/builtin-probe.c   |    2 +-
 tools/perf/util/build-id.c   |   33 ++++++++++++++++++++++++++++++++-
 tools/perf/util/build-id.h   |    2 +-
 tools/perf/util/probe-file.c |    2 +-
 4 files changed, 35 insertions(+), 4 deletions(-)

tools/perf/builtin-probe.c +1 -1

index a1a5cd1..de75af5 100644
@@ -370,7 +370,7 @@ static int del_perf_probe_caches(struct strfilter *filter)
 	struct str_node *nd;
 	int ret;
 
-	bidlist = build_id_cache__list_all();
+	bidlist = build_id_cache__list_all(false);
 	if (!bidlist) {
 		ret = -errno;
 		pr_debug("Failed to get buildids: %d\n", ret);

tools/perf/util/build-id.c +32 -1

index e1a1640..8e86a83 100644
@@ -206,6 +206,31 @@ out:
 	return ret;
 }
 
+/* Check if the given build_id cache is valid on current running system */
+static bool build_id_cache__valid_id(char *sbuild_id)
+{
+	char real_sbuild_id[SBUILD_ID_SIZE] = "";
+	char *pathname;
+	int ret = 0;
+	bool result = false;
+
+	pathname = build_id_cache__origname(sbuild_id);
+	if (!pathname)
+		return false;
+
+	if (!strcmp(pathname, DSO__NAME_KALLSYMS))
+		ret = sysfs__sprintf_build_id("/", real_sbuild_id);
+	else if (pathname[0] == '/')
+		ret = filename__sprintf_build_id(pathname, real_sbuild_id);
+	else
+		ret = -EINVAL;	/* Should we support other special DSO cache? */
+	if (ret >= 0)
+		result = (strcmp(sbuild_id, real_sbuild_id) == 0);
+	free(pathname);
+
+	return result;
+}
+
 static const char *build_id_cache__basename(bool is_kallsyms, bool is_vdso)
 {
 	return is_kallsyms ? "kallsyms" : (is_vdso ? "vdso" : "elf");

@@ -433,13 +458,17 @@ static bool lsdir_bid_tail_filter(const char *name __maybe_unused,
 	return (i == SBUILD_ID_SIZE - 3) && (d->d_name[i] == '\0');
 }
 
-struct strlist *build_id_cache__list_all(void)
+struct strlist *build_id_cache__list_all(bool validonly)
 {
 	struct strlist *toplist, *linklist = NULL, *bidlist;
 	struct str_node *nd, *nd2;
 	char *topdir, *linkdir = NULL;
 	char sbuild_id[SBUILD_ID_SIZE];
 
+	/* for filename__ functions */
+	if (validonly)
+		symbol__init(NULL);
+
 	/* Open the top-level directory */
 	if (asprintf(&topdir, "%s/.build-id/", buildid_dir) < 0)
 		return NULL;

@@ -470,6 +499,8 @@ struct strlist *build_id_cache__list_all(void)
 			if (snprintf(sbuild_id, SBUILD_ID_SIZE, "%s%s",
 				     nd->s, nd2->s) != SBUILD_ID_SIZE - 1)
 				goto err_out;
+			if (validonly && !build_id_cache__valid_id(sbuild_id))
+				continue;
 			if (strlist__add(bidlist, sbuild_id) < 0)
 				goto err_out;
 		}

tools/perf/util/build-id.h +1 -1

index b742e27..64e740f 100644
@@ -34,7 +34,7 @@ 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);
+struct strlist *build_id_cache__list_all(bool validonly);
 int build_id_cache__list_build_ids(const char *pathname,
 				   struct strlist **result);
 bool build_id_cache__cached(const char *sbuild_id);

tools/perf/util/probe-file.c +1 -1

index b642d06..b062545 100644
@@ -806,7 +806,7 @@ int probe_cache__show_all_caches(struct strfilter *filter)
 	pr_debug("list cache with filter: %s\n", buf);
 	free(buf);
 
-	bidlist = build_id_cache__list_all();
+	bidlist = build_id_cache__list_all(true);
 	if (!bidlist) {
 		pr_debug("Failed to get buildids: %d\n", errno);
 		return -EINVAL;

Em Tue, Jul 12, 2016 at 07:04:54PM +0900, Masami Hiramatsu escreveu:

Quoted 4 lines

From: Masami Hiramatsu <[email protected]>

Make "perf probe --cache --list" shows only available cached events by checking build-id validity.

Something is missing here, I tried following these steps and couldn't get to the same results, can you retry them at this point in time, i.e. after applying just the three first patches in this series?

I'm continuing anyway, as I want to check the rest...

- Arnaldo

Quoted 3 lines

E.g. without this patch:
----

  $ ./perf probe --cache --add oldevent=cmd_probe

Quoted 1 line

  $ make #(to update ./perf)

Quoted 136 lines

  $ ./perf probe --cache --add newevent=cmd_probe
  $ ./perf probe --cache --list
  /home/mhiramat/ksrc/linux/tools/perf/perf (061e90539bac69
  probe_perf:newevent=cmd_probe
  /home/mhiramat/ksrc/linux/tools/perf/perf (c2e44d614e33e1
  probe_perf:oldevent=cmd_probe
  ----
It shows both of old and new events but user can not use old one.
With this;
  ----
  $ ./perf probe --cache -l
  /home/mhiramat/ksrc/linux/tools/perf/perf (061e90539bac69
  probe_perf:newevent=cmd_probe
  ----
This show only new event which is on the existing binary.

Signed-off-by Masami Hiramatsu <[email protected]>

Signed-off-by Masami Hiramatsu <[email protected]>

---
Changes in v13:
- Instead of the perf-list, apply this change for perf-probe --list because of avoiding to confuse user.
Changes in v7:
- Validate build-id via sysfs if it is for kallsyms,
Changes in v4:
- Rename a parameter 'valid' to 'validonly' :)

---
 tools/perf/builtin-probe.c   |    2 +-
 tools/perf/util/build-id.c   |   33 ++++++++++++++++++++++++++++++++-
 tools/perf/util/build-id.h   |    2 +-
 tools/perf/util/probe-file.c |    2 +-
 4 files changed, 35 insertions(+), 4 deletions(-)

tools/perf/builtin-probe.c +1 -1

index a1a5cd1..de75af5 100644
@@ -370,7 +370,7 @@ static int del_perf_probe_caches(struct strfilter *filter)
 	struct str_node *nd;
 	int ret;
 
-	bidlist = build_id_cache__list_all();
+	bidlist = build_id_cache__list_all(false);
 	if (!bidlist) {
 		ret = -errno;
 		pr_debug("Failed to get buildids: %d\n", ret);

tools/perf/util/build-id.c +32 -1

index e1a1640..8e86a83 100644
@@ -206,6 +206,31 @@ out:
 	return ret;
 }
 
+/* Check if the given build_id cache is valid on current running system */
+static bool build_id_cache__valid_id(char *sbuild_id)
+{
+	char real_sbuild_id[SBUILD_ID_SIZE] = "";
+	char *pathname;
+	int ret = 0;
+	bool result = false;
+
+	pathname = build_id_cache__origname(sbuild_id);
+	if (!pathname)
+		return false;
+
+	if (!strcmp(pathname, DSO__NAME_KALLSYMS))
+		ret = sysfs__sprintf_build_id("/", real_sbuild_id);
+	else if (pathname[0] == '/')
+		ret = filename__sprintf_build_id(pathname, real_sbuild_id);
+	else
+		ret = -EINVAL;	/* Should we support other special DSO cache? */
+	if (ret >= 0)
+		result = (strcmp(sbuild_id, real_sbuild_id) == 0);
+	free(pathname);
+
+	return result;
+}
+
 static const char *build_id_cache__basename(bool is_kallsyms, bool is_vdso)
 {
 	return is_kallsyms ? "kallsyms" : (is_vdso ? "vdso" : "elf");

@@ -433,13 +458,17 @@ static bool lsdir_bid_tail_filter(const char *name __maybe_unused,
 	return (i == SBUILD_ID_SIZE - 3) && (d->d_name[i] == '\0');
 }
 
-struct strlist *build_id_cache__list_all(void)
+struct strlist *build_id_cache__list_all(bool validonly)
 {
 	struct strlist *toplist, *linklist = NULL, *bidlist;
 	struct str_node *nd, *nd2;
 	char *topdir, *linkdir = NULL;
 	char sbuild_id[SBUILD_ID_SIZE];
 
+	/* for filename__ functions */
+	if (validonly)
+		symbol__init(NULL);
+
 	/* Open the top-level directory */
 	if (asprintf(&topdir, "%s/.build-id/", buildid_dir) < 0)
 		return NULL;

@@ -470,6 +499,8 @@ struct strlist *build_id_cache__list_all(void)
 			if (snprintf(sbuild_id, SBUILD_ID_SIZE, "%s%s",
 				     nd->s, nd2->s) != SBUILD_ID_SIZE - 1)
 				goto err_out;
+			if (validonly && !build_id_cache__valid_id(sbuild_id))
+				continue;
 			if (strlist__add(bidlist, sbuild_id) < 0)
 				goto err_out;
 		}

tools/perf/util/build-id.h +1 -1

index b742e27..64e740f 100644
@@ -34,7 +34,7 @@ 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);
+struct strlist *build_id_cache__list_all(bool validonly);
 int build_id_cache__list_build_ids(const char *pathname,
 				   struct strlist **result);
 bool build_id_cache__cached(const char *sbuild_id);

tools/perf/util/probe-file.c +1 -1

index b642d06..b062545 100644
@@ -806,7 +806,7 @@ int probe_cache__show_all_caches(struct strfilter *filter)
 	pr_debug("list cache with filter: %s\n", buf);
 	free(buf);
 
-	bidlist = build_id_cache__list_all();
+	bidlist = build_id_cache__list_all(true);
 	if (!bidlist) {
 		pr_debug("Failed to get buildids: %d\n", errno);
 		return -EINVAL;

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.

Signed-off-by Masami Hiramatsu <[email protected]>

---
Changes in v12:
- Rename strlist__for_each to strlist__for_each_entry.
Changes in v10:
- Split off bugfix, adding interface, and target search patches.
- Do not export clear_probe_trace_events().
Changes in v7:
- Continue to search caches if a build-id cache has no probe cache.
- Make probe_cache__open() to accept DSO__NAME_KALLSYMS for kernel.
- Fix to add probes correctly when a wildcard matchs both of uprobes and kprobes.
Changes in v5.1:
- Fix a SEGV bug when a group name is omitted. (Thanks Hemant!)

---
 tools/perf/util/probe-event.c |  107 +++++++++++++++++++++++++++++++++++++++--
 tools/perf/util/probe-file.c  |   38 ++++++++++++---
 tools/perf/util/probe-file.h  |    3 +
 3 files changed, 138 insertions(+), 10 deletions(-)

tools/perf/util/probe-event.c +103 -4

index 3642cca..1aeac09 100644
@@ -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;

tools/perf/util/probe-file.c +32 -6

index 9152ad2..78a84f5 100644
@@ -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;

tools/perf/util/probe-file.h +3 -0

index d513b34..cafbe1d 100644
@@ -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,

Support @BUILDID or @FILE suffix for SDT events. This allows perf to add probes on SDTs/pre-cached events on given FILE or the file which has given BUILDID (also, this complements BUILDID.)
For example, both gcc and libstdc++ has same SDTs as below. If you would like to add a probe on sdt_libstdcxx:catch on gcc, you can do as below.

----

  # perf list sdt | tail -n 6
    sdt_libstdcxx:catch@/usr/bin/gcc(0cc207fc4b27)     [SDT event]
    sdt_libstdcxx:catch@/usr/lib64/libstdc++.so.6.0.20(91c7a88fdf49)
    sdt_libstdcxx:rethrow@/usr/bin/gcc(0cc207fc4b27)   [SDT event]
    sdt_libstdcxx:rethrow@/usr/lib64/libstdc++.so.6.0.20(91c7a88fdf49)
    sdt_libstdcxx:throw@/usr/bin/gcc(0cc207fc4b27)     [SDT event]
    sdt_libstdcxx:throw@/usr/lib64/libstdc++.so.6.0.20(91c7a88fdf49)
  # perf probe -a %sdt_libstdcxx:catch@0cc
  Added new event:
    sdt_libstdcxx:catch  (on %catch in /usr/bin/gcc)

You can now use it in all perf tools, such as:

perf record -e sdt_libstdcxx:catch -aR sleep 1
----

Signed-off-by Masami Hiramatsu <[email protected]>

---
Changes in v12:
- Rename strlist__for_each to strlist__for_each_entry.

---
 tools/perf/util/build-id.c    |   43 +++++++++++++++++++++++++++++++++++++++++
 tools/perf/util/build-id.h    |    1 +
 tools/perf/util/probe-event.c |   17 ++++++++++++++--
 3 files changed, 59 insertions(+), 2 deletions(-)

tools/perf/util/build-id.c +43 -0

index 8e86a83..e59003e 100644
@@ -523,6 +523,49 @@ err_out:
 	goto out_free;
 }
 
+static bool str_is_build_id(const char *maybe_sbuild_id, size_t len)
+{
+	size_t i;
+
+	for (i = 0; i < len; i++) {
+		if (!isxdigit(maybe_sbuild_id[i]))
+			return false;
+	}
+	return true;
+}
+
+/* Return the valid complete build-id */
+char *build_id_cache__complement(const char *incomplete_sbuild_id)
+{
+	struct strlist *bidlist;
+	struct str_node *nd, *cand = NULL;
+	char *sbuild_id = NULL;
+	size_t len = strlen(incomplete_sbuild_id);
+
+	if (len >= SBUILD_ID_SIZE ||
+	    !str_is_build_id(incomplete_sbuild_id, len))
+		return NULL;
+
+	bidlist = build_id_cache__list_all(true);
+	if (!bidlist)
+		return NULL;
+
+	strlist__for_each_entry(nd, bidlist) {
+		if (strncmp(nd->s, incomplete_sbuild_id, len) != 0)
+			continue;
+		if (cand) {	/* Error: There are more than 2 candidates. */
+			cand = NULL;
+			break;
+		}
+		cand = nd;
+	}
+	if (cand)
+		sbuild_id = strdup(cand->s);
+	strlist__delete(bidlist);
+
+	return sbuild_id;
+}
+
 char *build_id_cache__cachedir(const char *sbuild_id, const char *name,
 			       bool is_kallsyms, bool is_vdso)
 {

tools/perf/util/build-id.h +1 -0

index 64e740f..d279906 100644
@@ -35,6 +35,7 @@ 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(bool validonly);
+char *build_id_cache__complement(const char *incomplete_sbuild_id);
 int build_id_cache__list_build_ids(const char *pathname,
 				   struct strlist **result);
 bool build_id_cache__cached(const char *sbuild_id);

tools/perf/util/probe-event.c +15 -2

index 679aa6b..0dadaa3 100644
@@ -1251,8 +1251,21 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
 	ptr = strpbrk(arg, ";=@+%");
 	if (pev->sdt) {
 		if (ptr) {
-			semantic_error("%s must contain only an SDT event name.\n", arg);
-			return -EINVAL;
+			if (*ptr != '@') {
+				semantic_error("%s must be an SDT name.\n",
+					       arg);
+				return -EINVAL;
+			}
+			/* This must be a target file name or build id */
+			tmp = build_id_cache__complement(ptr + 1);
+			if (tmp) {
+				pev->target = build_id_cache__origname(tmp);
+				free(tmp);
+			} else
+				pev->target = strdup(ptr + 1);
+			if (!pev->target)
+				return -ENOMEM;
+			*ptr = '\0';
 		}
 		ret = parse_perf_probe_event_name(&arg, pev);
 		if (ret == 0) {

Em Tue, Jul 12, 2016 at 07:05:37PM +0900, Masami Hiramatsu escreveu:

Quoted 7 lines

Support @BUILDID or @FILE suffix for SDT events. This allows perf to add probes on SDTs/pre-cached events on given FILE or the file which has given BUILDID (also, this complements BUILDID.)
For example, both gcc and libstdc++ has same SDTs as below. If you would like to add a probe on sdt_libstdcxx:catch on gcc, you can do as below.

Ok, how to add those entries?

[root@jouet hello_world]# perf probe -x /usr/bin/gcc -a %sdt_gcc:\*
Error: Failed to add events.
[root@jouet hello_world]# perf probe --verbose -x /usr/bin/gcc -a %sdt_gcc:\* probe-definition(0): %sdt_gcc:*
0 arguments
symbol:throw file:(null) line:0 offset:0 return:0 lazy:(null) symbol:rethrow file:(null) line:0 offset:0 return:0 lazy:(null) symbol:catch file:(null) line:0 offset:0 return:0 lazy:(null) symbol:unwind file:(null) line:0 offset:0 return:0 lazy:(null)
Error: Failed to add events. Reason: No such file or directory (Code: -2)
[root@jouet hello_world]#

Can those messages be improved? What am I missing?

Quoted 121 lines

----

  # perf list sdt | tail -n 6
    sdt_libstdcxx:catch@/usr/bin/gcc(0cc207fc4b27)     [SDT event]
    sdt_libstdcxx:catch@/usr/lib64/libstdc++.so.6.0.20(91c7a88fdf49)
    sdt_libstdcxx:rethrow@/usr/bin/gcc(0cc207fc4b27)   [SDT event]
    sdt_libstdcxx:rethrow@/usr/lib64/libstdc++.so.6.0.20(91c7a88fdf49)
    sdt_libstdcxx:throw@/usr/bin/gcc(0cc207fc4b27)     [SDT event]
    sdt_libstdcxx:throw@/usr/lib64/libstdc++.so.6.0.20(91c7a88fdf49)
  # perf probe -a %sdt_libstdcxx:catch@0cc
  Added new event:
    sdt_libstdcxx:catch  (on %catch in /usr/bin/gcc)

You can now use it in all perf tools, such as:

perf record -e sdt_libstdcxx:catch -aR sleep 1
----

Signed-off-by Masami Hiramatsu <[email protected]>

---
Changes in v12:
- Rename strlist__for_each to strlist__for_each_entry.

---
 tools/perf/util/build-id.c    |   43 +++++++++++++++++++++++++++++++++++++++++
 tools/perf/util/build-id.h    |    1 +
 tools/perf/util/probe-event.c |   17 ++++++++++++++--
 3 files changed, 59 insertions(+), 2 deletions(-)

tools/perf/util/build-id.c +43 -0

index 8e86a83..e59003e 100644
@@ -523,6 +523,49 @@ err_out:
 	goto out_free;
 }
 
+static bool str_is_build_id(const char *maybe_sbuild_id, size_t len)
+{
+	size_t i;
+
+	for (i = 0; i < len; i++) {
+		if (!isxdigit(maybe_sbuild_id[i]))
+			return false;
+	}
+	return true;
+}
+
+/* Return the valid complete build-id */
+char *build_id_cache__complement(const char *incomplete_sbuild_id)
+{
+	struct strlist *bidlist;
+	struct str_node *nd, *cand = NULL;
+	char *sbuild_id = NULL;
+	size_t len = strlen(incomplete_sbuild_id);
+
+	if (len >= SBUILD_ID_SIZE ||
+	    !str_is_build_id(incomplete_sbuild_id, len))
+		return NULL;
+
+	bidlist = build_id_cache__list_all(true);
+	if (!bidlist)
+		return NULL;
+
+	strlist__for_each_entry(nd, bidlist) {
+		if (strncmp(nd->s, incomplete_sbuild_id, len) != 0)
+			continue;
+		if (cand) {	/* Error: There are more than 2 candidates. */
+			cand = NULL;
+			break;
+		}
+		cand = nd;
+	}
+	if (cand)
+		sbuild_id = strdup(cand->s);
+	strlist__delete(bidlist);
+
+	return sbuild_id;
+}
+
 char *build_id_cache__cachedir(const char *sbuild_id, const char *name,
 			       bool is_kallsyms, bool is_vdso)
 {

tools/perf/util/build-id.h +1 -0

index 64e740f..d279906 100644
@@ -35,6 +35,7 @@ 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(bool validonly);
+char *build_id_cache__complement(const char *incomplete_sbuild_id);
 int build_id_cache__list_build_ids(const char *pathname,
 				   struct strlist **result);
 bool build_id_cache__cached(const char *sbuild_id);

tools/perf/util/probe-event.c +15 -2

index 679aa6b..0dadaa3 100644
@@ -1251,8 +1251,21 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
 	ptr = strpbrk(arg, ";=@+%");
 	if (pev->sdt) {
 		if (ptr) {
-			semantic_error("%s must contain only an SDT event name.\n", arg);
-			return -EINVAL;
+			if (*ptr != '@') {
+				semantic_error("%s must be an SDT name.\n",
+					       arg);
+				return -EINVAL;
+			}
+			/* This must be a target file name or build id */
+			tmp = build_id_cache__complement(ptr + 1);
+			if (tmp) {
+				pev->target = build_id_cache__origname(tmp);
+				free(tmp);
+			} else
+				pev->target = strdup(ptr + 1);
+			if (!pev->target)
+				return -ENOMEM;
+			*ptr = '\0';
 		}
 		ret = parse_perf_probe_event_name(&arg, pev);
 		if (ret == 0) {

I'm going to look my inbox for patches I overlook that added 'perf list sdt'...

Em Wed, Jul 13, 2016 at 09:07:19PM -0300, Arnaldo Carvalho de Melo escreveu:

Quoted 1 line

I'm going to look my inbox for patches I overlook that added 'perf list sdt'...

So it is here:

-> 976 T 06/24 Masami Hiramats (7.2K) [PATCH perf/core v12 08/16] perf-list: Show SDT and pre-cached events

June, 24, you forgot to rebase it for this new cset series, I'm doing that now.

Em Wed, Jul 13, 2016 at 09:16:32PM -0300, Arnaldo Carvalho de Melo escreveu:

Quoted 9 lines

Em Wed, Jul 13, 2016 at 09:07:19PM -0300, Arnaldo Carvalho de Melo escreveu:

Quoted 1 line

I'm going to look my inbox for patches I overlook that added 'perf list sdt'...

So it is here:

-> 976 T 06/24 Masami Hiramats (7.2K) [PATCH perf/core v12 08/16] perf-list: Show SDT and pre-cached events

June, 24, you forgot to rebase it for this new cset series, I'm doing that now.

Ok, now it works:

[root@jouet ~]# perf list sdt

List of pre-defined events (to be used in -e):

  sdt_libc:lll_lock_wait_private                     [SDT event]
  sdt_libc:longjmp                                   [SDT event]
  sdt_libc:longjmp_target                            [SDT event]
  sdt_libc:memory_arena_new                          [SDT event]
  sdt_libc:memory_arena_retry                        [SDT event]
  sdt_libc:memory_arena_reuse                        [SDT event]
  sdt_libc:memory_arena_reuse_free_list              [SDT event]
  sdt_libc:memory_arena_reuse_wait                   [SDT event]
  sdt_libc:memory_calloc_retry                       [SDT event]
  sdt_libc:memory_heap_free                          [SDT event]
  sdt_libc:memory_heap_less                          [SDT event]
  sdt_libc:memory_heap_more                          [SDT event]
  sdt_libc:memory_heap_new                           [SDT event]
  sdt_libc:memory_malloc_retry                       [SDT event]
  sdt_libc:memory_mallopt                            [SDT event]
  sdt_libc:memory_mallopt_arena_max                  [SDT event]
  sdt_libc:memory_mallopt_arena_test                 [SDT event]
  sdt_libc:memory_mallopt_check_action               [SDT event]
  sdt_libc:memory_mallopt_free_dyn_thresholds        [SDT event]
  sdt_libc:memory_mallopt_mmap_max                   [SDT event]
  sdt_libc:memory_mallopt_mmap_threshold             [SDT event]
  sdt_libc:memory_mallopt_mxfast                     [SDT event]
  sdt_libc:memory_mallopt_perturb                    [SDT event]
  sdt_libc:memory_mallopt_top_pad                    [SDT event]
  sdt_libc:memory_mallopt_trim_threshold             [SDT event]
  sdt_libc:memory_memalign_retry                     [SDT event]
  sdt_libc:memory_realloc_retry                      [SDT event]
  sdt_libc:memory_sbrk_less                          [SDT event]
  sdt_libc:memory_sbrk_more                          [SDT event]
  sdt_libc:setjmp                                    [SDT event]
  sdt_libgcc:unwind                                  [SDT event]
  sdt_libstdcxx:catch@/usr/bin/gcc(9a0730e2bcc6)     [SDT event]

sdt_libstdcxx:catch@/usr/lib64/libstdc++.so.6.0.22(ef2b7066559a) [SDT event]
sdt_libstdcxx:rethrow@/usr/bin/gcc(9a0730e2bcc6) [SDT event]
sdt_libstdcxx:rethrow@/usr/lib64/libstdc++.so.6.0.22(ef2b7066559a) [SDT event]
sdt_libstdcxx:throw@/usr/bin/gcc(9a0730e2bcc6) [SDT event]
sdt_libstdcxx:throw@/usr/lib64/libstdc++.so.6.0.22(ef2b7066559a) [SDT event]
[root@jouet ~]#

Hi,

Here is the 14th version of the patchset for probe-cache and initial SDT support.

Here is the previous v13: https://lkml.org/lkml/2016/7/1/133

This version includes patches which not merged yet. This also adds a bugfix;
- [1/10] Resend the bugfix patch which was sent 4th July.

          (https://lkml.org/lkml/2016/7/3/217)

Thank you,

---

Masami Hiramatsu (10):
[BUGFIX] perf-probe: Fix to show correct error message for $vars and $params perf probe: Accept %sdt and %cached event name
perf-probe: Make --list shows only available cached events
perf: probe-cache: Add for_each_probe_cache_entry() wrapper perf probe: Allow wildcard for cached events
perf probe: Search SDT/cached event from all probe caches
perf probe: Support @BUILDID or @FILE suffix for SDT events perf probe: Support a special SDT probe format
perf build: Add sdt feature detection
perf-test: Add a test case for SDT event

 tools/perf/Documentation/perf-probe.txt |   11 +
 tools/perf/Makefile.perf                |    3 
 tools/perf/builtin-probe.c              |    2 
 tools/perf/config/Makefile              |   10 +
 tools/perf/tests/Build                  |    1 
 tools/perf/tests/builtin-test.c         |    4 
 tools/perf/tests/make                   |    3 
 tools/perf/tests/sdt.c                  |  115 ++++++++++++
 tools/perf/tests/tests.h                |    1 
 tools/perf/util/build-id.c              |   76 ++++++++
 tools/perf/util/build-id.h              |    3 
 tools/perf/util/probe-event.c           |  309 +++++++++++++++++++++++++++----
 tools/perf/util/probe-event.h           |    1 
 tools/perf/util/probe-file.c            |   57 +++++-
 tools/perf/util/probe-file.h            |    5 +
 15 files changed, 542 insertions(+), 59 deletions(-)
 create mode 100644 tools/perf/tests/sdt.c

--
Masami Hiramatsu