Skip to contentSkip to conversation

perf-probe --cache and SDT support

PATCH Superseded Masami Hiramatsu 4 participants 24 messages May 15, 2016 – May 20, 2016 perf events

v8 of 13 Superseded Latest is v13 →

lore
Share & tools
lore
#0 lore raw

v8 cover perf-probe --cache and SDT support

Hi,

Here is the 8th version of the patchset for probe-cache and initial SDT support.

The previous version is here; https://lkml.org/lkml/2016/5/11/446

This version I droped the second patch in v7 because it may involves unintended behavior change and we'd better discuss it out of this series. I also added comments why we can't use access(R_OK) for /proc/kcore.

Hemant, could you review and test this series so that we can proceed to your patch depending on this?

Thank you,

---

Hemant Kumar (1):
perf/sdt: ELF support for SDT

Masami Hiramatsu (15):
perf buildid: Introduce DSO__NAME_KALLSYMS and DSO__NAME_KCORE perf symbol: Cleanup the code flow of dso__find_kallsyms
perf-buildid-cache: Use path/to/bin/buildid/elf instead of path/to/bin/buildid perf probe: Add --cache option to cache the probe definitions perf probe: Use cache entry if possible
perf probe: Show all cached probes
perf probe: Remove caches when --cache is given
perf probe: Add group name support
perf buildid-cache: Scan and import user SDT events to probe cache perf probe: Accept %sdt and %cached event name
perf-list: Show SDT and pre-cached events
perf-list: Skip SDTs placed in invalid binaries
perf probe: Allow wildcard for cached events
perf probe: Support @BUILDID or @FILE suffix for SDT events
perf probe: Support a special SDT probe format

 tools/perf/Documentation/perf-probe.txt |   26 +-
 tools/perf/builtin-buildid-cache.c      |    8 
 tools/perf/builtin-list.c               |    4 
 tools/perf/builtin-probe.c              |   30 ++
 tools/perf/util/annotate.c              |    2 
 tools/perf/util/build-id.c              |  295 ++++++++++++++++--
 tools/perf/util/build-id.h              |    8 
 tools/perf/util/dso.h                   |    5 
 tools/perf/util/machine.c               |    2 
 tools/perf/util/parse-events.c          |   83 +++++
 tools/perf/util/parse-events.h          |    2 
 tools/perf/util/probe-event.c           |  492 +++++++++++++++++++++++++++---
 tools/perf/util/probe-event.h           |    7 
 tools/perf/util/probe-file.c            |  502 +++++++++++++++++++++++++++++++
 tools/perf/util/probe-file.h            |   41 +++
 tools/perf/util/symbol-elf.c            |  252 ++++++++++++++++
 tools/perf/util/symbol.c                |   73 ++---
 tools/perf/util/symbol.h                |   25 ++
 18 files changed, 1719 insertions(+), 138 deletions(-)

--
Masami Hiramatsu

#1 lore raw

PATCH v8 1/16 perf buildid: Introduce DSO__NAME_KALLSYMS and DSO__NAME_KCORE

Instead of using raw string, use DSO__NAME_KALLSYMS and DSO__NAME_KCORE macros for kallsyms and kcore.

---
 tools/perf/builtin-buildid-cache.c |    8 ++++----
 tools/perf/util/annotate.c         |    2 +-
 tools/perf/util/machine.c          |    2 +-
 tools/perf/util/symbol.c           |   10 +++++-----
 tools/perf/util/symbol.h           |    3 +++
 5 files changed, 14 insertions(+), 11 deletions(-)
tools/perf/builtin-buildid-cache.c +4 -4
index 632efc6..d75bded 100644
@@ -119,8 +119,8 @@ static int build_id_cache__add_kcore(const char *filename, bool force)
 	if (build_id_cache__kcore_buildid(from_dir, sbuildid) < 0)
 		return -1;
 
-	scnprintf(to_dir, sizeof(to_dir), "%s/[kernel.kcore]/%s",
-		  buildid_dir, sbuildid);
+	scnprintf(to_dir, sizeof(to_dir), "%s/%s/%s",
+		  buildid_dir, DSO__NAME_KCORE, sbuildid);
 
 	if (!force &&
 	    !build_id_cache__kcore_existing(from_dir, to_dir, sizeof(to_dir))) {
@@ -131,8 +131,8 @@ static int build_id_cache__add_kcore(const char *filename, bool force)
 	if (build_id_cache__kcore_dir(dir, sizeof(dir)))
 		return -1;
 
-	scnprintf(to_dir, sizeof(to_dir), "%s/[kernel.kcore]/%s/%s",
-		  buildid_dir, sbuildid, dir);
+	scnprintf(to_dir, sizeof(to_dir), "%s/%s/%s/%s",
+		  buildid_dir, DSO__NAME_KCORE, sbuildid, dir);
 
 	if (mkdir_p(to_dir, 0755))
 		return -1;
tools/perf/util/annotate.c +1 -1
index 4db73d5..b811924 100644
@@ -1122,7 +1122,7 @@ int symbol__annotate(struct symbol *sym, struct map *map, size_t privsize)
 	} else if (dso__is_kcore(dso)) {
 		goto fallback;
 	} else if (readlink(symfs_filename, command, sizeof(command)) < 0 ||
-		   strstr(command, "[kernel.kallsyms]") ||
+		   strstr(command, DSO__NAME_KALLSYMS) ||
 		   access(symfs_filename, R_OK)) {
 		free(filename);
 fallback:
tools/perf/util/machine.c +1 -1
index 639a290..18dd96b 100644
@@ -709,7 +709,7 @@ static struct dso *machine__get_kernel(struct machine *machine)
 	if (machine__is_host(machine)) {
 		vmlinux_name = symbol_conf.vmlinux_name;
 		if (!vmlinux_name)
-			vmlinux_name = "[kernel.kallsyms]";
+			vmlinux_name = DSO__NAME_KALLSYMS;
 
 		kernel = machine__findnew_kernel(machine, vmlinux_name,
 						 "[kernel]", DSO_TYPE_KERNEL);
tools/perf/util/symbol.c +5 -5
index 7fb3330..2252b54 100644
@@ -1662,8 +1662,8 @@ static char *dso__find_kallsyms(struct dso *dso, struct map *map)
 
 	build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
 
-	scnprintf(path, sizeof(path), "%s/[kernel.kcore]/%s", buildid_dir,
-		  sbuild_id);
+	scnprintf(path, sizeof(path), "%s/%s/%s", buildid_dir,
+		  DSO__NAME_KCORE, sbuild_id);
 
 	/* Use /proc/kallsyms if possible */
 	if (is_host) {
@@ -1699,8 +1699,8 @@ static char *dso__find_kallsyms(struct dso *dso, struct map *map)
 	if (!find_matching_kcore(map, path, sizeof(path)))
 		return strdup(path);
 
-	scnprintf(path, sizeof(path), "%s/[kernel.kallsyms]/%s",
-		  buildid_dir, sbuild_id);
+	scnprintf(path, sizeof(path), "%s/%s/%s",
+		  buildid_dir, DSO__NAME_KALLSYMS, sbuild_id);
 
 	if (access(path, F_OK)) {
 		pr_err("No kallsyms or vmlinux with build-id %s was found\n",
@@ -1769,7 +1769,7 @@ do_kallsyms:
 
 	if (err > 0 && !dso__is_kcore(dso)) {
 		dso->binary_type = DSO_BINARY_TYPE__KALLSYMS;
-		dso__set_long_name(dso, "[kernel.kallsyms]", false);
+		dso__set_long_name(dso, DSO__NAME_KALLSYMS, false);
 		map__fixup_start(map);
 		map__fixup_end(map);
 	}
tools/perf/util/symbol.h +3 -0
index 2b5e4ed..25f2fd67 100644
@@ -44,6 +44,9 @@ Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
 #define DMGL_ANSI        (1 << 1)       /* Include const, volatile, etc */
 #endif
 
+#define DSO__NAME_KALLSYMS	"[kernel.kallsyms]"
+#define DSO__NAME_KCORE		"[kernel.kcore]"
+
 /** struct symbol - symtab entry
  *
  * @ignore - resolvable but tools ignore it (e.g. idle routines)
#2 lore raw

[tip:perf/urgent] perf symbols: Introduce DSO__NAME_KALLSYMS and DSO__NAME_KCORE

perf symbols: Introduce DSO__NAME_KALLSYMS and DSO__NAME_KCORE
Commit-ID:  0a77582f0407e7f9b5d775bebc31297a1b890be0
Gitweb:     http://git.kernel.org/tip/0a77582f0407e7f9b5d775bebc31297a1b890be0
Author:     Masami Hiramatsu <[email protected]>
AuthorDate: Sun, 15 May 2016 12:19:40 +0900
Committer:  Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Mon, 16 May 2016 23:11:48 -0300

perf symbols: Introduce DSO__NAME_KALLSYMS and DSO__NAME_KCORE

Instead of using a raw string, use DSO__NAME_KALLSYMS and DSO__NAME_KCORE macros for kallsyms and kcore.

---
 tools/perf/builtin-buildid-cache.c |  8 ++++----
 tools/perf/util/annotate.c         |  2 +-
 tools/perf/util/machine.c          |  2 +-
 tools/perf/util/symbol.c           | 10 +++++-----
 tools/perf/util/symbol.h           |  3 +++
 5 files changed, 14 insertions(+), 11 deletions(-)
tools/perf/builtin-buildid-cache.c +4 -4
index 632efc6..d75bded 100644
@@ -119,8 +119,8 @@ static int build_id_cache__add_kcore(const char *filename, bool force)
 	if (build_id_cache__kcore_buildid(from_dir, sbuildid) < 0)
 		return -1;
 
-	scnprintf(to_dir, sizeof(to_dir), "%s/[kernel.kcore]/%s",
-		  buildid_dir, sbuildid);
+	scnprintf(to_dir, sizeof(to_dir), "%s/%s/%s",
+		  buildid_dir, DSO__NAME_KCORE, sbuildid);
 
 	if (!force &&
 	    !build_id_cache__kcore_existing(from_dir, to_dir, sizeof(to_dir))) {
@@ -131,8 +131,8 @@ static int build_id_cache__add_kcore(const char *filename, bool force)
 	if (build_id_cache__kcore_dir(dir, sizeof(dir)))
 		return -1;
 
-	scnprintf(to_dir, sizeof(to_dir), "%s/[kernel.kcore]/%s/%s",
-		  buildid_dir, sbuildid, dir);
+	scnprintf(to_dir, sizeof(to_dir), "%s/%s/%s/%s",
+		  buildid_dir, DSO__NAME_KCORE, sbuildid, dir);
 
 	if (mkdir_p(to_dir, 0755))
 		return -1;
tools/perf/util/annotate.c +1 -1
index 4db73d5..b811924 100644
@@ -1122,7 +1122,7 @@ int symbol__annotate(struct symbol *sym, struct map *map, size_t privsize)
 	} else if (dso__is_kcore(dso)) {
 		goto fallback;
 	} else if (readlink(symfs_filename, command, sizeof(command)) < 0 ||
-		   strstr(command, "[kernel.kallsyms]") ||
+		   strstr(command, DSO__NAME_KALLSYMS) ||
 		   access(symfs_filename, R_OK)) {
 		free(filename);
 fallback:
tools/perf/util/machine.c +1 -1
index 639a290..18dd96b 100644
@@ -709,7 +709,7 @@ static struct dso *machine__get_kernel(struct machine *machine)
 	if (machine__is_host(machine)) {
 		vmlinux_name = symbol_conf.vmlinux_name;
 		if (!vmlinux_name)
-			vmlinux_name = "[kernel.kallsyms]";
+			vmlinux_name = DSO__NAME_KALLSYMS;
 
 		kernel = machine__findnew_kernel(machine, vmlinux_name,
 						 "[kernel]", DSO_TYPE_KERNEL);
tools/perf/util/symbol.c +5 -5
index 7fb3330..2252b54 100644
@@ -1662,8 +1662,8 @@ static char *dso__find_kallsyms(struct dso *dso, struct map *map)
 
 	build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
 
-	scnprintf(path, sizeof(path), "%s/[kernel.kcore]/%s", buildid_dir,
-		  sbuild_id);
+	scnprintf(path, sizeof(path), "%s/%s/%s", buildid_dir,
+		  DSO__NAME_KCORE, sbuild_id);
 
 	/* Use /proc/kallsyms if possible */
 	if (is_host) {
@@ -1699,8 +1699,8 @@ static char *dso__find_kallsyms(struct dso *dso, struct map *map)
 	if (!find_matching_kcore(map, path, sizeof(path)))
 		return strdup(path);
 
-	scnprintf(path, sizeof(path), "%s/[kernel.kallsyms]/%s",
-		  buildid_dir, sbuild_id);
+	scnprintf(path, sizeof(path), "%s/%s/%s",
+		  buildid_dir, DSO__NAME_KALLSYMS, sbuild_id);
 
 	if (access(path, F_OK)) {
 		pr_err("No kallsyms or vmlinux with build-id %s was found\n",
@@ -1769,7 +1769,7 @@ do_kallsyms:
 
 	if (err > 0 && !dso__is_kcore(dso)) {
 		dso->binary_type = DSO_BINARY_TYPE__KALLSYMS;
-		dso__set_long_name(dso, "[kernel.kallsyms]", false);
+		dso__set_long_name(dso, DSO__NAME_KALLSYMS, false);
 		map__fixup_start(map);
 		map__fixup_end(map);
 	}
tools/perf/util/symbol.h +3 -0
index 2b5e4ed..25f2fd67 100644
@@ -44,6 +44,9 @@ Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
 #define DMGL_ANSI        (1 << 1)       /* Include const, volatile, etc */
 #endif
 
+#define DSO__NAME_KALLSYMS	"[kernel.kallsyms]"
+#define DSO__NAME_KCORE		"[kernel.kcore]"
+
 /** struct symbol - symtab entry
  *
  * @ignore - resolvable but tools ignore it (e.g. idle routines)
#3 lore raw

PATCH v8 2/16 perf symbol: Cleanup the code flow of dso__find_kallsyms

In reply to Masami Hiramatsu

Cleanup the code flow of dso__find_kallsyms() to remove redundant checking code and add some comment for readability.

---
Changes in v8:
- Add comments why we can't use access(R_OK) for /proc/kcore access.

---
 tools/perf/util/symbol.c |   68 ++++++++++++++++++++++++----------------------
 1 file changed, 35 insertions(+), 33 deletions(-)
tools/perf/util/symbol.c +35 -33
index 2252b54..abda8ba 100644
@@ -1641,6 +1641,20 @@ static int find_matching_kcore(struct map *map, char *dir, size_t dir_sz)
 	return ret;
 }
 
+/*
+ * Use open(O_RDONLY) to check readability directly instead of access(R_OK)
+ * since access(R_OK) only checks with real UID/GID but open() use effective
+ * UID/GID and actual capabilities (e.g. /proc/kcore requires CAP_SYS_RAWIO).
+ */
+static bool filename__readable(const char *file)
+{
+	int fd = open(file, O_RDONLY);
+	if (fd < 0)
+		return false;
+	close(fd);
+	return true;
+}
+
 static char *dso__find_kallsyms(struct dso *dso, struct map *map)
 {
 	u8 host_build_id[BUILD_ID_SIZE];
@@ -1660,45 +1674,36 @@ static char *dso__find_kallsyms(struct dso *dso, struct map *map)
 				 sizeof(host_build_id)) == 0)
 		is_host = dso__build_id_equal(dso, host_build_id);
 
-	build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
-
-	scnprintf(path, sizeof(path), "%s/%s/%s", buildid_dir,
-		  DSO__NAME_KCORE, sbuild_id);
-
-	/* Use /proc/kallsyms if possible */
+	/* Try a fast path for /proc/kallsyms if possible */
 	if (is_host) {
-		DIR *d;
-		int fd;
-
-		/* If no cached kcore go with /proc/kallsyms */
-		d = opendir(path);
-		if (!d)
-			goto proc_kallsyms;
-		closedir(d);
-
 		/*
-		 * Do not check the build-id cache, until we know we cannot use
-		 * /proc/kcore.
+		 * Do not check the build-id cache, unless we know we cannot use
+		 * /proc/kcore or module maps don't match to /proc/kallsyms.
+		 * To check readability of /proc/kcore, do not use access(R_OK)
+		 * since /proc/kcore requires CAP_SYS_RAWIO to read and access
+		 * can't check it.
 		 */
-		fd = open("/proc/kcore", O_RDONLY);
-		if (fd != -1) {
-			close(fd);
-			/* If module maps match go with /proc/kallsyms */
-			if (!validate_kcore_addresses("/proc/kallsyms", map))
-				goto proc_kallsyms;
-		}
-
-		/* Find kallsyms in build-id cache with kcore */
-		if (!find_matching_kcore(map, path, sizeof(path)))
-			return strdup(path);
-
-		goto proc_kallsyms;
+		if (filename__readable("/proc/kcore") &&
+		    !validate_kcore_addresses("/proc/kallsyms", map))
+			goto proc_kallsyms;
 	}
 
+	build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
+
 	/* Find kallsyms in build-id cache with kcore */
+	scnprintf(path, sizeof(path), "%s/%s/%s",
+		  buildid_dir, DSO__NAME_KCORE, sbuild_id);
+
 	if (!find_matching_kcore(map, path, sizeof(path)))
 		return strdup(path);
 
+	/* Use current /proc/kallsyms if possible */
+	if (is_host) {
+proc_kallsyms:
+		return strdup("/proc/kallsyms");
+	}
+
+	/* Finally, find a cache of kallsyms */
 	scnprintf(path, sizeof(path), "%s/%s/%s",
 		  buildid_dir, DSO__NAME_KALLSYMS, sbuild_id);
 
@@ -1709,9 +1714,6 @@ static char *dso__find_kallsyms(struct dso *dso, struct map *map)
 	}
 
 	return strdup(path);
-
-proc_kallsyms:
-	return strdup("/proc/kallsyms");
 }
 
 static int dso__load_kernel_sym(struct dso *dso, struct map *map,
#4 lore raw

Re: [PATCH perf/core v8 02/16] perf symbol: Cleanup the code flow of dso__find_kallsyms

Em Sun, May 15, 2016 at 12:19:50PM +0900, Masami Hiramatsu escreveu:

Quoted 2 lines

Cleanup the code flow of dso__find_kallsyms() to remove redundant checking code and add some comment for readability.

Thanks for adding the comment, I'll wait for Hemant to review this, if you respin it, please break this patch into multiple ones, for instance, the first should do just the filename__readable() part, then try to check if you could split it further, to ease reviewing.

I applied the first patch already.

- Arnaldo

Quoted 110 lines

---
Changes in v8:
- Add comments why we can't use access(R_OK) for /proc/kcore access.

---
 tools/perf/util/symbol.c |   68 ++++++++++++++++++++++++----------------------
 1 file changed, 35 insertions(+), 33 deletions(-)
tools/perf/util/symbol.c +35 -33
index 2252b54..abda8ba 100644
@@ -1641,6 +1641,20 @@ static int find_matching_kcore(struct map *map, char *dir, size_t dir_sz)
 	return ret;
 }
 
+/*
+ * Use open(O_RDONLY) to check readability directly instead of access(R_OK)
+ * since access(R_OK) only checks with real UID/GID but open() use effective
+ * UID/GID and actual capabilities (e.g. /proc/kcore requires CAP_SYS_RAWIO).
+ */
+static bool filename__readable(const char *file)
+{
+	int fd = open(file, O_RDONLY);
+	if (fd < 0)
+		return false;
+	close(fd);
+	return true;
+}
+
 static char *dso__find_kallsyms(struct dso *dso, struct map *map)
 {
 	u8 host_build_id[BUILD_ID_SIZE];
@@ -1660,45 +1674,36 @@ static char *dso__find_kallsyms(struct dso *dso, struct map *map)
 				 sizeof(host_build_id)) == 0)
 		is_host = dso__build_id_equal(dso, host_build_id);
 
-	build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
-
-	scnprintf(path, sizeof(path), "%s/%s/%s", buildid_dir,
-		  DSO__NAME_KCORE, sbuild_id);
-
-	/* Use /proc/kallsyms if possible */
+	/* Try a fast path for /proc/kallsyms if possible */
 	if (is_host) {
-		DIR *d;
-		int fd;
-
-		/* If no cached kcore go with /proc/kallsyms */
-		d = opendir(path);
-		if (!d)
-			goto proc_kallsyms;
-		closedir(d);
-
 		/*
-		 * Do not check the build-id cache, until we know we cannot use
-		 * /proc/kcore.
+		 * Do not check the build-id cache, unless we know we cannot use
+		 * /proc/kcore or module maps don't match to /proc/kallsyms.
+		 * To check readability of /proc/kcore, do not use access(R_OK)
+		 * since /proc/kcore requires CAP_SYS_RAWIO to read and access
+		 * can't check it.
 		 */
-		fd = open("/proc/kcore", O_RDONLY);
-		if (fd != -1) {
-			close(fd);
-			/* If module maps match go with /proc/kallsyms */
-			if (!validate_kcore_addresses("/proc/kallsyms", map))
-				goto proc_kallsyms;
-		}
-
-		/* Find kallsyms in build-id cache with kcore */
-		if (!find_matching_kcore(map, path, sizeof(path)))
-			return strdup(path);
-
-		goto proc_kallsyms;
+		if (filename__readable("/proc/kcore") &&
+		    !validate_kcore_addresses("/proc/kallsyms", map))
+			goto proc_kallsyms;
 	}
 
+	build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
+
 	/* Find kallsyms in build-id cache with kcore */
+	scnprintf(path, sizeof(path), "%s/%s/%s",
+		  buildid_dir, DSO__NAME_KCORE, sbuild_id);
+
 	if (!find_matching_kcore(map, path, sizeof(path)))
 		return strdup(path);
 
+	/* Use current /proc/kallsyms if possible */
+	if (is_host) {
+proc_kallsyms:
+		return strdup("/proc/kallsyms");
+	}
+
+	/* Finally, find a cache of kallsyms */
 	scnprintf(path, sizeof(path), "%s/%s/%s",
 		  buildid_dir, DSO__NAME_KALLSYMS, sbuild_id);
 
@@ -1709,9 +1714,6 @@ static char *dso__find_kallsyms(struct dso *dso, struct map *map)
 	}
 
 	return strdup(path);
-
-proc_kallsyms:
-	return strdup("/proc/kallsyms");
 }
 
 static int dso__load_kernel_sym(struct dso *dso, struct map *map,
#5 lore raw

PATCH v8 3/16 perf-buildid-cache: Use path/to/bin/buildid/elf instead of path/to/bin/buildid

In reply to Masami Hiramatsu

From: Masami Hiramatsu <[email protected]>

Use path/to/bin/buildid/elf instead of path/to/bin/buildid to store corresponding elf binary.
This also stores vdso in buildid/vdso, kallsyms in buildid/kallsyms.

Note that the existing caches are not updated until user adds or updates the cache. Anyway, if there is the old style build-id cache it falls back to use it. (IOW, it is backward compatible)

---
Changes in v7:
- Move kallsyms buildid related code into build-id.c
(as build_id_cache__kallsyms_path).
Changes in v6:
- Replace local __is_regular_file with is_regular_file in util.c. (Thank you Namhyung!)
- Fix dso__build_id_is_kmod() to check symlink in buildid cache correctly.
Changes in v5:
- Support old style buildid caches.

---
 tools/perf/util/build-id.c |  115 ++++++++++++++++++++++++++++++++++----------
 tools/perf/util/build-id.h |    2 +
 tools/perf/util/dso.h      |    5 ++
 tools/perf/util/symbol.c   |    5 --
 4 files changed, 96 insertions(+), 31 deletions(-)
tools/perf/util/build-id.c +88 -27
index 67e5966..67f986c 100644
@@ -144,7 +144,32 @@ static int asnprintf(char **strp, size_t size, const char *fmt, ...)
 	return ret;
 }
 
-static char *build_id__filename(const char *sbuild_id, char *bf, size_t size)
+char *build_id_cache__kallsyms_path(const char *sbuild_id, char *bf,
+				    size_t size)
+{
+	bool is_alloc = !!bf;
+	bool retry_old = true;
+
+	asnprintf(&bf, size, "%s/%s/%s/kallsyms",
+		  buildid_dir, DSO__NAME_KALLSYMS, sbuild_id);
+retry:
+	if (!access(bf, F_OK))
+		return bf;
+	if (is_alloc)
+		free(bf);
+	if (retry_old) {
+		/* Try old style kallsyms cache */
+		asnprintf(&bf, size, "%s/%s/%s",
+			  buildid_dir, DSO__NAME_KALLSYMS, sbuild_id);
+		retry_old = false;
+		goto retry;
+	}
+
+	return NULL;
+}
+
+static 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,
@@ -154,23 +179,52 @@ static char *build_id__filename(const char *sbuild_id, char *bf, size_t size)
 	return bf;
 }
 
+static const char *build_id_cache__basename(bool is_kallsyms, bool is_vdso)
+{
+	return is_kallsyms ? "kallsyms" : (is_vdso ? "vdso" : "elf");
+}
+
 char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size)
 {
-	char build_id_hex[SBUILD_ID_SIZE];
+	bool is_kallsyms = dso__is_kallsyms((struct dso *)dso);
+	bool is_vdso = dso__is_vdso((struct dso *)dso);
+	char sbuild_id[SBUILD_ID_SIZE];
+	char *linkname;
+	bool alloc = (bf == NULL);
+	int ret;
 
 	if (!dso->has_build_id)
 		return NULL;
 
-	build_id__sprintf(dso->build_id, sizeof(dso->build_id), build_id_hex);
-	return build_id__filename(build_id_hex, bf, size);
+	build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
+	linkname = build_id_cache__linkname(sbuild_id, NULL, 0);
+	if (!linkname)
+		return NULL;
+
+	/* Check if old style build_id cache */
+	if (is_regular_file(linkname))
+		ret = asnprintf(&bf, size, "%s", linkname);
+	else
+		ret = asnprintf(&bf, size, "%s/%s", linkname,
+			 build_id_cache__basename(is_kallsyms, is_vdso));
+	if (ret < 0 || (!alloc && size < (unsigned int)ret))
+		bf = NULL;
+	free(linkname);
+
+	return bf;
 }
 
 bool dso__build_id_is_kmod(const struct dso *dso, char *bf, size_t size)
 {
-	char *id_name, *ch;
+	char *id_name = NULL, *ch;
 	struct stat sb;
+	char sbuild_id[SBUILD_ID_SIZE];
+
+	if (!dso->has_build_id)
+		goto err;
 
-	id_name = dso__build_id_filename(dso, bf, size);
+	build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
+	id_name = build_id_cache__linkname(sbuild_id, NULL, 0);
 	if (!id_name)
 		goto err;
 	if (access(id_name, F_OK))
@@ -194,18 +248,14 @@ bool dso__build_id_is_kmod(const struct dso *dso, char *bf, size_t size)
 	if (ch - 3 < bf)
 		goto err;
 
+	free(id_name);
 	return strncmp(".ko", ch - 3, 3) == 0;
 err:
-	/*
-	 * If dso__build_id_filename work, get id_name again,
-	 * because id_name points to bf and is broken.
-	 */
-	if (id_name)
-		id_name = dso__build_id_filename(dso, bf, size);
 	pr_err("Invalid build id: %s\n", id_name ? :
 					 dso->long_name ? :
 					 dso->short_name ? :
 					 "[unknown]");
+	free(id_name);
 	return false;
 }
 
@@ -341,7 +391,8 @@ void disable_buildid_cache(void)
 }
 
 static char *build_id_cache__dirname_from_path(const char *name,
-					       bool is_kallsyms, bool is_vdso)
+					       bool is_kallsyms, bool is_vdso,
+					       const char *sbuild_id)
 {
 	char *realname = (char *)name, *filename;
 	bool slash = is_kallsyms || is_vdso;
@@ -352,8 +403,9 @@ static char *build_id_cache__dirname_from_path(const char *name,
 			return NULL;
 	}
 
-	if (asprintf(&filename, "%s%s%s", buildid_dir, slash ? "/" : "",
-		     is_vdso ? DSO__NAME_VDSO : realname) < 0)
+	if (asprintf(&filename, "%s%s%s%s%s", buildid_dir, slash ? "/" : "",
+		     is_vdso ? DSO__NAME_VDSO : realname,
+		     sbuild_id ? "/" : "", sbuild_id ?: "") < 0)
 		filename = NULL;
 
 	if (!slash)
@@ -368,7 +420,8 @@ int build_id_cache__list_build_ids(const char *pathname,
 	char *dir_name;
 	int ret = 0;
 
-	dir_name = build_id_cache__dirname_from_path(pathname, false, false);
+	dir_name = build_id_cache__dirname_from_path(pathname, false, false,
+						     NULL);
 	if (!dir_name)
 		return -ENOMEM;
 
@@ -385,7 +438,7 @@ int build_id_cache__add_s(const char *sbuild_id, const char *name,
 {
 	const size_t size = PATH_MAX;
 	char *realname = NULL, *filename = NULL, *dir_name = NULL,
-	     *linkname = zalloc(size), *targetname, *tmp;
+	     *linkname = zalloc(size), *tmp;
 	int err = -1;
 
 	if (!is_kallsyms) {
@@ -394,14 +447,22 @@ int build_id_cache__add_s(const char *sbuild_id, const char *name,
 			goto out_free;
 	}
 
-	dir_name = build_id_cache__dirname_from_path(name, is_kallsyms, is_vdso);
+	dir_name = build_id_cache__dirname_from_path(name, is_kallsyms,
+						     is_vdso, sbuild_id);
 	if (!dir_name)
 		goto out_free;
 
+	/* Remove old style build-id cache */
+	if (is_regular_file(dir_name))
+		if (unlink(dir_name))
+			goto out_free;
+
 	if (mkdir_p(dir_name, 0755))
 		goto out_free;
 
-	if (asprintf(&filename, "%s/%s", dir_name, sbuild_id) < 0) {
+	/* Save the allocated buildid dirname */
+	if (asprintf(&filename, "%s/%s", dir_name,
+		     build_id_cache__basename(is_kallsyms, is_vdso)) < 0) {
 		filename = NULL;
 		goto out_free;
 	}
@@ -415,7 +476,7 @@ int build_id_cache__add_s(const char *sbuild_id, const char *name,
 			goto out_free;
 	}
 
-	if (!build_id__filename(sbuild_id, linkname, size))
+	if (!build_id_cache__linkname(sbuild_id, linkname, size))
 		goto out_free;
 	tmp = strrchr(linkname, '/');
 	*tmp = '\0';
@@ -424,10 +485,10 @@ int build_id_cache__add_s(const char *sbuild_id, const char *name,
 		goto out_free;
 
 	*tmp = '/';
-	targetname = filename + strlen(buildid_dir) - 5;
-	memcpy(targetname, "../..", 5);
+	tmp = dir_name + strlen(buildid_dir) - 5;
+	memcpy(tmp, "../..", 5);
 
-	if (symlink(targetname, linkname) == 0)
+	if (symlink(tmp, linkname) == 0)
 		err = 0;
 out_free:
 	if (!is_kallsyms)
@@ -452,7 +513,7 @@ static int build_id_cache__add_b(const u8 *build_id, size_t build_id_size,
 bool build_id_cache__cached(const char *sbuild_id)
 {
 	bool ret = false;
-	char *filename = build_id__filename(sbuild_id, NULL, 0);
+	char *filename = build_id_cache__linkname(sbuild_id, NULL, 0);
 
 	if (filename && !access(filename, F_OK))
 		ret = true;
@@ -471,7 +532,7 @@ int build_id_cache__remove_s(const char *sbuild_id)
 	if (filename == NULL || linkname == NULL)
 		goto out_free;
 
-	if (!build_id__filename(sbuild_id, linkname, size))
+	if (!build_id_cache__linkname(sbuild_id, linkname, size))
 		goto out_free;
 
 	if (access(linkname, F_OK))
@@ -489,7 +550,7 @@ int build_id_cache__remove_s(const char *sbuild_id)
 	tmp = strrchr(linkname, '/') + 1;
 	snprintf(tmp, size - (tmp - linkname), "%s", filename);
 
-	if (unlink(linkname))
+	if (rm_rf(linkname))
 		goto out_free;
 
 	err = 0;
@@ -501,7 +562,7 @@ out_free:
 
 static int dso__cache_build_id(struct dso *dso, struct machine *machine)
 {
-	bool is_kallsyms = dso->kernel && dso->long_name[0] != '/';
+	bool is_kallsyms = dso__is_kallsyms(dso);
 	bool is_vdso = dso__is_vdso(dso);
 	const char *name = dso->long_name;
 	char nm[PATH_MAX];
tools/perf/util/build-id.h +2 -0
index 64af3e2..e5435f4 100644
@@ -14,6 +14,8 @@ struct dso;
 int build_id__sprintf(const u8 *build_id, int len, char *bf);
 int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id);
 int filename__sprintf_build_id(const char *pathname, char *sbuild_id);
+char *build_id_cache__kallsyms_path(const char *sbuild_id, char *bf,
+				    size_t size);
 
 char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size);
 bool dso__build_id_is_kmod(const struct dso *dso, char *bf, size_t size);
tools/perf/util/dso.h +5 -0
index 0953280..76d79d0 100644
@@ -349,6 +349,11 @@ static inline bool dso__is_kcore(struct dso *dso)
 	       dso->binary_type == DSO_BINARY_TYPE__GUEST_KCORE;
 }
 
+static inline bool dso__is_kallsyms(struct dso *dso)
+{
+	return dso->kernel && dso->long_name[0] != '/';
+}
+
 void dso__free_a2l(struct dso *dso);
 
 enum dso_type dso__type(struct dso *dso, struct machine *machine);
tools/perf/util/symbol.c +1 -4
index abda8ba..9aa73de 100644
@@ -1704,10 +1704,7 @@ proc_kallsyms:
 	}
 
 	/* Finally, find a cache of kallsyms */
-	scnprintf(path, sizeof(path), "%s/%s/%s",
-		  buildid_dir, DSO__NAME_KALLSYMS, sbuild_id);
-
-	if (access(path, F_OK)) {
+	if (!build_id_cache__kallsyms_path(sbuild_id, path, sizeof(path))) {
 		pr_err("No kallsyms or vmlinux with build-id %s was found\n",
 		       sbuild_id);
 		return NULL;
#6 lore raw

PATCH v8 4/16 perf probe: Add --cache option to cache the probe definitions

In reply to Masami Hiramatsu

From: Masami Hiramatsu <[email protected]>

Add --cache option to cache the probe definitions. This just saves the result of the dwarf analysis to probe cache.

---
Changes in v6:
- Remove unneeded O_APPEND from open(). (Thanks Namhyung!)
- Fix to check the return value of probe_cache_entry__new and strdup.(ditto)
Changes in v5:
- Move probe_cache* definitions. (code cleanup)

Changes in v4:
- Remove cache saving failure message.

---
 tools/perf/Documentation/perf-probe.txt |    4 
 tools/perf/builtin-probe.c              |    1 
 tools/perf/util/build-id.c              |   12 +
 tools/perf/util/build-id.h              |    2 
 tools/perf/util/probe-event.c           |  124 +++++++++++--
 tools/perf/util/probe-event.h           |    5 +
 tools/perf/util/probe-file.c            |  307 +++++++++++++++++++++++++++++++
 tools/perf/util/probe-file.h            |   19 ++
 8 files changed, 447 insertions(+), 27 deletions(-)
tools/perf/Documentation/perf-probe.txt +4 -0
index 3a8a9ba..947db6f 100644
@@ -109,6 +109,10 @@ OPTIONS
 	Dry run. With this option, --add and --del doesn't execute actual
 	adding and removal operations.
 
+--cache::
+	Cache the probes (with --add option). Any events which successfully added
+	are also stored in the cache file.
+
 --max-probes=NUM::
 	Set the maximum number of probe points for an event. Default is 128.
 
tools/perf/builtin-probe.c +1 -0
index 9af859b..6d7ab431 100644
@@ -512,6 +512,7 @@ __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
 		    "Enable symbol demangling"),
 	OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,
 		    "Enable kernel symbol demangling"),
+	OPT_BOOLEAN(0, "cache", &probe_conf.cache, "Manipulate probe cache"),
 	OPT_END()
 	};
 	int ret;
tools/perf/util/build-id.c +5 -7
index 67f986c..ccf0d0d 100644
@@ -390,9 +390,8 @@ void disable_buildid_cache(void)
 	no_buildid_cache = true;
 }
 
-static char *build_id_cache__dirname_from_path(const char *name,
-					       bool is_kallsyms, bool is_vdso,
-					       const char *sbuild_id)
+char *build_id_cache__cachedir(const char *sbuild_id, const char *name,
+			       bool is_kallsyms, bool is_vdso)
 {
 	char *realname = (char *)name, *filename;
 	bool slash = is_kallsyms || is_vdso;
@@ -420,8 +419,7 @@ int build_id_cache__list_build_ids(const char *pathname,
 	char *dir_name;
 	int ret = 0;
 
-	dir_name = build_id_cache__dirname_from_path(pathname, false, false,
-						     NULL);
+	dir_name = build_id_cache__cachedir(NULL, pathname, false, false);
 	if (!dir_name)
 		return -ENOMEM;
 
@@ -447,8 +445,8 @@ int build_id_cache__add_s(const char *sbuild_id, const char *name,
 			goto out_free;
 	}
 
-	dir_name = build_id_cache__dirname_from_path(name, is_kallsyms,
-						     is_vdso, sbuild_id);
+	dir_name = build_id_cache__cachedir(sbuild_id, name,
+					    is_kallsyms, is_vdso);
 	if (!dir_name)
 		goto out_free;
 
tools/perf/util/build-id.h +2 -0
index e5435f4..d8c7f2f 100644
@@ -30,6 +30,8 @@ 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__cachedir(const char *sbuild_id, const char *name,
+			       bool is_kallsyms, bool is_vdso);
 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 +104 -20

175 lines not on this page · raw message

tools/perf/util/probe-event.h +5 -0
index 5a27eb4..432b690 100644
@@ -12,6 +12,7 @@ struct probe_conf {
 	bool	show_location_range;
 	bool	force_add;
 	bool	no_inlines;
+	bool	cache;
 	int	max_probes;
 };
 extern struct probe_conf probe_conf;
@@ -121,6 +122,10 @@ int parse_probe_trace_command(const char *cmd, struct probe_trace_event *tev);
 char *synthesize_perf_probe_command(struct perf_probe_event *pev);
 char *synthesize_probe_trace_command(struct probe_trace_event *tev);
 char *synthesize_perf_probe_arg(struct perf_probe_arg *pa);
+char *synthesize_perf_probe_point(struct perf_probe_point *pp);
+
+int perf_probe_event__copy(struct perf_probe_event *dst,
+			   struct perf_probe_event *src);
 
 /* Check the perf_probe_event needs debuginfo */
 bool perf_probe_event_need_dwarf(struct perf_probe_event *pev);
tools/perf/util/probe-file.c +307 -0

316 lines not on this page · raw message

tools/perf/util/probe-file.h +19 -0
index 18ac9cf..d2b8791d 100644
@@ -5,6 +5,19 @@
 #include "strfilter.h"
 #include "probe-event.h"
 
+/* Cache of probe definitions */
+struct probe_cache_entry {
+	struct list_head	list;
+	struct perf_probe_event pev;
+	char			*spev;
+	struct strlist		*tevlist;
+};
+
+struct probe_cache {
+	int	fd;
+	struct list_head list;
+};
+
 #define PF_FL_UPROBE	1
 #define PF_FL_RW	2
 
@@ -18,5 +31,11 @@ int probe_file__get_events(int fd, struct strfilter *filter,
 				  struct strlist *plist);
 int probe_file__del_strlist(int fd, struct strlist *namelist);
 
+struct probe_cache *probe_cache__new(const char *target);
+int probe_cache__add_entry(struct probe_cache *pcache,
+			   struct perf_probe_event *pev,
+			   struct probe_trace_event *tevs, int ntevs);
+int probe_cache__commit(struct probe_cache *pcache);
+void probe_cache__delete(struct probe_cache *pcache);
 
 #endif
#7 lore raw

PATCH v8 5/16 perf probe: Use cache entry if possible

In reply to Masami Hiramatsu

From: Masami Hiramatsu <[email protected]>

Before analyzing debuginfo, try to find a corresponding entry from probe cache always. This does not depend on --cache, the --cache enables to store/update cache, but looking up the cache is always enabled.

---
Changes in v6:
- Remove fallback lookup routine by using function name as cached event name, because it should be done by following patch which supports %cached-event.

---
 tools/perf/util/probe-event.c |   65 ++++++++++++++++++++++++++++++++++++++++-
 tools/perf/util/probe-file.c  |   20 ++++++++++++-
 tools/perf/util/probe-file.h  |    5 +++
 3 files changed, 86 insertions(+), 4 deletions(-)
tools/perf/util/probe-event.c +63 -2
index 854885b..acc8341 100644
@@ -2472,17 +2472,24 @@ static int probe_trace_event__set_name(struct probe_trace_event *tev,
 	char buf[64];
 	int ret;
 
+	/* If probe_event or trace_event already have the name, reuse it */
 	if (pev->event)
 		event = pev->event;
-	else
+	else if (tev->event)
+		event = tev->event;
+	else {
+		/* Or generate new one from probe point */
 		if (pev->point.function &&
 			(strncmp(pev->point.function, "0x", 2) != 0) &&
 			!strisglob(pev->point.function))
 			event = pev->point.function;
 		else
 			event = tev->point.realname;
+	}
 	if (pev->group)
 		group = pev->group;
+	else if (tev->group)
+		group = tev->group;
 	else
 		group = PERFPROBE_GROUP;
 
@@ -2529,7 +2536,7 @@ static int __add_probe_trace_events(struct perf_probe_event *pev,
 	for (i = 0; i < ntevs; i++) {
 		tev = &tevs[i];
 		/* Skip if the symbol is out of .text or blacklisted */
-		if (!tev->point.symbol)
+		if (!tev->point.symbol && !pev->uprobes)
 			continue;
 
 		/* Set new name for tev (and update namelist) */
@@ -2842,6 +2849,55 @@ errout:
 
 bool __weak arch__prefers_symtab(void) { return false; }
 
+static int find_probe_trace_events_from_cache(struct perf_probe_event *pev,
+					      struct probe_trace_event **tevs)
+{
+	struct probe_cache *cache;
+	struct probe_cache_entry *entry;
+	struct probe_trace_event *tev;
+	struct str_node *node;
+	int ret, i;
+
+	cache = probe_cache__new(pev->target);
+	if (!cache)
+		return 0;
+
+	entry = probe_cache__find(cache, pev);
+	if (!entry) {
+		ret = 0;
+		goto out;
+	}
+
+	ret = strlist__nr_entries(entry->tevlist);
+	if (ret > probe_conf.max_probes) {
+		pr_debug("Too many entries matched in the cache of %s\n",
+			 pev->target ? : "kernel");
+		ret = -E2BIG;
+		goto out;
+	}
+
+	*tevs = zalloc(ret * sizeof(*tev));
+	if (!*tevs) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	i = 0;
+	strlist__for_each(node, entry->tevlist) {
+		tev = &(*tevs)[i++];
+		ret = parse_probe_trace_command(node->s, tev);
+		if (ret < 0)
+			goto out;
+		/* Set the uprobes attribute as same as original */
+		tev->uprobes = pev->uprobes;
+	}
+	ret = i;
+
+out:
+	probe_cache__delete(cache);
+	return ret;
+}
+
 static int convert_to_probe_trace_events(struct perf_probe_event *pev,
 					 struct probe_trace_event **tevs)
 {
@@ -2864,6 +2920,11 @@ static int convert_to_probe_trace_events(struct perf_probe_event *pev,
 	if (ret > 0)
 		return ret;
 
+	/* At first, we need to lookup cache entry */
+	ret = find_probe_trace_events_from_cache(pev, tevs);
+	if (ret > 0)
+		return ret;	/* Found in probe cache */
+
 	if (arch__prefers_symtab() && !perf_probe_event_need_dwarf(pev)) {
 		ret = find_probe_trace_events_from_map(pev, tevs);
 		if (ret > 0)
tools/perf/util/probe-file.c +19 -1
index 689d874..f30f609 100644
@@ -514,7 +514,7 @@ static bool streql(const char *a, const char *b)
 	return !strcmp(a, b);
 }
 
-static struct probe_cache_entry *
+struct probe_cache_entry *
 probe_cache__find(struct probe_cache *pcache, struct perf_probe_event *pev)
 {
 	struct probe_cache_entry *entry = NULL;
@@ -539,6 +539,24 @@ found:
 	return entry;
 }
 
+struct probe_cache_entry *
+probe_cache__find_by_name(struct probe_cache *pcache,
+			  const char *group, const char *event)
+{
+	struct probe_cache_entry *entry = NULL;
+
+	list_for_each_entry(entry, &pcache->list, list) {
+		/* Hit if same event name or same command-string */
+		if (streql(entry->pev.group, group) &&
+		    streql(entry->pev.event, event))
+			goto found;
+	}
+	entry = NULL;
+
+found:
+	return entry;
+}
+
 int probe_cache__add_entry(struct probe_cache *pcache,
 			   struct perf_probe_event *pev,
 			   struct probe_trace_event *tevs, int ntevs)
tools/perf/util/probe-file.h +4 -1
index d2b8791d..1385c8b 100644
@@ -37,5 +37,8 @@ int probe_cache__add_entry(struct probe_cache *pcache,
 			   struct probe_trace_event *tevs, int ntevs);
 int probe_cache__commit(struct probe_cache *pcache);
 void probe_cache__delete(struct probe_cache *pcache);
-
+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);
 #endif
#8 lore raw

PATCH v8 6/16 perf probe: Show all cached probes

In reply to Masami Hiramatsu

From: Masami Hiramatsu <[email protected]>

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.

---
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              |   86 ++++++++++++++++++++++++++++++-
 tools/perf/util/build-id.h              |    3 +
 tools/perf/util/probe-event.c           |    3 +
 tools/perf/util/probe-file.c            |   67 +++++++++++++++++++++++-
 tools/perf/util/probe-file.h            |    1 
 7 files changed, 163 insertions(+), 7 deletions(-)
tools/perf/Documentation/perf-probe.txt +6 -2
index 947db6f..5a70d45 100644
@@ -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.
tools/perf/builtin-probe.c +1 -1
index 6d7ab431..53e380c0e 100644
@@ -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 {
tools/perf/util/build-id.c +84 -2

104 lines not on this page · raw message

tools/perf/util/build-id.h +3 -0
index d8c7f2f..c05503e 100644
@@ -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);
+int build_id_cache__list_all(struct strlist **result);
 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 +3 -0
index acc8341..57fd657 100644
@@ -2364,6 +2364,9 @@ 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;
tools/perf/util/probe-file.c +65 -2

86 lines not on this page · raw message

tools/perf/util/probe-file.h +1 -0
index 1385c8b..ac70446 100644
@@ -41,4 +41,5 @@ 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
#9 lore raw

PATCH v8 7/16 perf probe: Remove caches when --cache is given

In reply to Masami Hiramatsu

From: Masami Hiramatsu <[email protected]>

perf-probe --del removes caches when --cache is given. Note that the delete pattern is not same as normal events.

If you cached probes with event name, --del "eventname" works as expected. However, if you skipped it, the cached probes doesn't have actual event name. In that case
--del "probe-desc" is required (wildcard is acceptable).
For example a cache entry has the probe-desc "vfs_read $params", you can remove it with --del 'vfs_read*'.

-----

  # perf probe --cache --list
  /[kernel.kallsyms] (1466a0a250b5d0070c6d0f03c5fed30b237970a1):
  vfs_read $params
  /usr/lib64/libc-2.17.so (c31ffe7942bfd77b2fca8f9bd5709d387a86d3bc):
  getaddrinfo $params
  # perf probe --cache --del vfs_read\*
  Removed event: probe:vfs_read
  # perf probe --cache --list
  /[kernel.kallsyms] (1466a0a250b5d0070c6d0f03c5fed30b237970a1):
  /usr/lib64/libc-2.17.so (c31ffe7942bfd77b2fca8f9bd5709d387a86d3bc):
  getaddrinfo $params
  -----

---
Changes in v4:
- move del_perf_probe_caches() into builtin-probe.c since command-line related delete procedure is there now.

---
 tools/perf/Documentation/perf-probe.txt |    1 +
 tools/perf/builtin-probe.c              |   27 ++++++++++++++++++++++++++
 tools/perf/util/probe-file.c            |   32 ++++++++++++++++++++++++-------
 tools/perf/util/probe-file.h            |    2 ++
 4 files changed, 55 insertions(+), 7 deletions(-)
tools/perf/Documentation/perf-probe.txt +1 -0
index 5a70d45..8d09173 100644
@@ -116,6 +116,7 @@ OPTIONS
 	(With --add) Cache the probes. Any events which successfully added
 	are also stored in the cache file.
 	(With --list) Show cached probes.
+	(With --del) Remove cached probes.
 
 --max-probes=NUM::
 	Set the maximum number of probe points for an event. Default is 128.
tools/perf/builtin-probe.c +27 -0
index 53e380c0e..8f61525 100644
@@ -363,6 +363,30 @@ out_cleanup:
 	return ret;
 }
 
+static int del_perf_probe_caches(struct strfilter *filter)
+{
+	struct probe_cache *cache;
+	struct strlist *bidlist;
+	struct str_node *nd;
+	int ret;
+
+	ret = build_id_cache__list_all(&bidlist);
+	if (ret < 0) {
+		pr_debug("Failed to get buildids: %d\n", ret);
+		return ret;
+	}
+
+	strlist__for_each(nd, bidlist) {
+		cache = probe_cache__new(nd->s);
+		if (!cache)
+			continue;
+		probe_cache__remove_entries(cache, filter);
+		probe_cache__commit(cache);
+		probe_cache__delete(cache);
+	}
+	return 0;
+}
+
 static int perf_del_probe_events(struct strfilter *filter)
 {
 	int ret, ret2, ufd = -1, kfd = -1;
@@ -375,6 +399,9 @@ static int perf_del_probe_events(struct strfilter *filter)
 
 	pr_debug("Delete filter: \'%s\'\n", str);
 
+	if (probe_conf.cache)
+		return del_perf_probe_caches(filter);
+
 	/* Get current event names */
 	ret = probe_file__open_both(&kfd, &ufd, PF_FL_RW);
 	if (ret < 0)
tools/perf/util/probe-file.c +25 -7
index a6d4a67..cc0f183 100644
@@ -660,19 +660,37 @@ out:
 	return ret;
 }
 
+static bool probe_cache_entry__compare(struct probe_cache_entry *entry,
+				       struct strfilter *filter)
+{
+	char buf[128], *ptr = entry->spev;
+
+	if (entry->pev.event) {
+		snprintf(buf, 128, "%s:%s", entry->pev.group, entry->pev.event);
+		ptr = buf;
+	}
+	return strfilter__compare(filter, ptr);
+}
+
+int probe_cache__remove_entries(struct probe_cache *pcache,
+				struct strfilter *filter)
+{
+	struct probe_cache_entry *entry, *tmp;
+
+	list_for_each_entry_safe(entry, tmp, &pcache->list, list) {
+		if (probe_cache_entry__compare(entry, filter))
+			probe_cache_entry__delete(entry);
+	}
+	return 0;
+}
+
 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->list, list) {
-		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))
+		if (probe_cache_entry__compare(entry, filter))
 			printf("%s\n", entry->spev);
 	}
 	return 0;
tools/perf/util/probe-file.h +2 -0
index ac70446..e6fd9b9 100644
@@ -37,6 +37,8 @@ int probe_cache__add_entry(struct probe_cache *pcache,
 			   struct probe_trace_event *tevs, int ntevs);
 int probe_cache__commit(struct probe_cache *pcache);
 void probe_cache__delete(struct probe_cache *pcache);
+int probe_cache__remove_entries(struct probe_cache *pcache,
+				struct strfilter *filter);
 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,
#10 lore raw

Re: [PATCH perf/core v8 07/16] perf probe: Remove caches when --cache is given

Hi Masami,

Quoted 12 lines · Masami Hiramatsu

From: Masami Hiramatsu <[email protected]>

perf-probe --del removes caches when --cache is given. Note that the delete pattern is not same as normal events.

If you cached probes with event name, --del "eventname" works as expected. However, if you skipped it, the cached probes doesn't have actual event name. In that case
--del "probe-desc" is required (wildcard is acceptable).
For example a cache entry has the probe-desc "vfs_read $params", you can remove it with --del 'vfs_read*'.

Quoted 9 lines
   -----
   # perf probe --cache --list
   /[kernel.kallsyms] (1466a0a250b5d0070c6d0f03c5fed30b237970a1):
   vfs_read $params
   /usr/lib64/libc-2.17.so (c31ffe7942bfd77b2fca8f9bd5709d387a86d3bc):
   getaddrinfo $params

   # perf probe --cache --del vfs_read\*
   Removed event: probe:vfs_read

Not sure where the o/p message for perf probe --cache --del is coming from here. So, if we are removing an event from the cache, is it intended to remove that from the {u,k}probe_events file as well?

The patch removes only from the cache (which I think is the intended behavior). With this patch, when I delete an event from the cache, it silently deletes it. So, do we add some kind of a message there?

# ./perf probe --cache --list
[kernel.kallsyms] (818a8e96766649cb2b62fc0bc3e66c27be0cd870):
vfs_read
/usr/lib64/libc-2.18.so (e8587f5d2edba244cc43368b5ebfce1782195b6f):
getaddrinfo $params
# ./perf probe --cache --del vfs_read\*
#

If we are silently removing the events from the cache, the commit message needs to be ammended.

Quoted 139 lines
   # perf probe --cache --list
   /[kernel.kallsyms] (1466a0a250b5d0070c6d0f03c5fed30b237970a1):
   /usr/lib64/libc-2.17.so (c31ffe7942bfd77b2fca8f9bd5709d387a86d3bc):
   getaddrinfo $params
   -----

---
Changes in v4:
- move del_perf_probe_caches() into builtin-probe.c since command-line related delete procedure is there now.

---
  tools/perf/Documentation/perf-probe.txt |    1 +
  tools/perf/builtin-probe.c              |   27 ++++++++++++++++++++++++++
  tools/perf/util/probe-file.c            |   32 ++++++++++++++++++++++++-------
  tools/perf/util/probe-file.h            |    2 ++
  4 files changed, 55 insertions(+), 7 deletions(-)
tools/perf/Documentation/perf-probe.txt +1 -0
index 5a70d45..8d09173 100644
@@ -116,6 +116,7 @@ OPTIONS
  	(With --add) Cache the probes. Any events which successfully added
  	are also stored in the cache file.
  	(With --list) Show cached probes.
+	(With --del) Remove cached probes.
 
  --max-probes=NUM::
  	Set the maximum number of probe points for an event. Default is 128.
tools/perf/builtin-probe.c +27 -0
index 53e380c0e..8f61525 100644
@@ -363,6 +363,30 @@ out_cleanup:
  	return ret;
  }
 
+static int del_perf_probe_caches(struct strfilter *filter)
+{
+	struct probe_cache *cache;
+	struct strlist *bidlist;
+	struct str_node *nd;
+	int ret;
+
+	ret = build_id_cache__list_all(&bidlist);
+	if (ret < 0) {
+		pr_debug("Failed to get buildids: %d\n", ret);
+		return ret;
+	}
+
+	strlist__for_each(nd, bidlist) {
+		cache = probe_cache__new(nd->s);
+		if (!cache)
+			continue;
+		probe_cache__remove_entries(cache, filter);
+		probe_cache__commit(cache);
+		probe_cache__delete(cache);
+	}
+	return 0;
+}
+
  static int perf_del_probe_events(struct strfilter *filter)
  {
  	int ret, ret2, ufd = -1, kfd = -1;
@@ -375,6 +399,9 @@ static int perf_del_probe_events(struct strfilter *filter)
 
  	pr_debug("Delete filter: \'%s\'\n", str);
 
+	if (probe_conf.cache)
+		return del_perf_probe_caches(filter);
+
  	/* Get current event names */
  	ret = probe_file__open_both(&kfd, &ufd, PF_FL_RW);
  	if (ret < 0)
tools/perf/util/probe-file.c +25 -7
index a6d4a67..cc0f183 100644
@@ -660,19 +660,37 @@ out:
  	return ret;
  }
 
+static bool probe_cache_entry__compare(struct probe_cache_entry *entry,
+				       struct strfilter *filter)
+{
+	char buf[128], *ptr = entry->spev;
+
+	if (entry->pev.event) {
+		snprintf(buf, 128, "%s:%s", entry->pev.group, entry->pev.event);
+		ptr = buf;
+	}
+	return strfilter__compare(filter, ptr);
+}
+
+int probe_cache__remove_entries(struct probe_cache *pcache,
+				struct strfilter *filter)
+{
+	struct probe_cache_entry *entry, *tmp;
+
+	list_for_each_entry_safe(entry, tmp, &pcache->list, list) {
+		if (probe_cache_entry__compare(entry, filter))
+			probe_cache_entry__delete(entry);
+	}
+	return 0;
+}
+
  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->list, list) {
-		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))
+		if (probe_cache_entry__compare(entry, filter))
  			printf("%s\n", entry->spev);
  	}
  	return 0;
tools/perf/util/probe-file.h +2 -0
index ac70446..e6fd9b9 100644
@@ -37,6 +37,8 @@ int probe_cache__add_entry(struct probe_cache *pcache,
  			   struct probe_trace_event *tevs, int ntevs);
  int probe_cache__commit(struct probe_cache *pcache);
  void probe_cache__delete(struct probe_cache *pcache);
+int probe_cache__remove_entries(struct probe_cache *pcache,
+				struct strfilter *filter);
  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,
Signature · 2 lines
Thanks,
Hemant Kumar
#11 lore raw

Re: [PATCH perf/core v8 07/16] perf probe: Remove caches when --cache is given

Quoted 22 lines · On Thu, 19 May 2016 06:15:38 +0530 Hemant Kumar <[email protected]>…

Hi Masami,

Quoted 19 lines · Masami Hiramatsu

From: Masami Hiramatsu <[email protected]>

perf-probe --del removes caches when --cache is given. Note that the delete pattern is not same as normal events.

If you cached probes with event name, --del "eventname" works as expected. However, if you skipped it, the cached probes doesn't have actual event name. In that case
--del "probe-desc" is required (wildcard is acceptable).
For example a cache entry has the probe-desc "vfs_read $params", you can remove it with --del 'vfs_read*'.

   -----
   # perf probe --cache --list
   /[kernel.kallsyms] (1466a0a250b5d0070c6d0f03c5fed30b237970a1):
   vfs_read $params
   /usr/lib64/libc-2.17.so (c31ffe7942bfd77b2fca8f9bd5709d387a86d3bc):
   getaddrinfo $params
Quoted 6 lines
Quoted 2 lines
   # perf probe --cache --del vfs_read\*
   Removed event: probe:vfs_read

Not sure where the o/p message for perf probe --cache --del is coming from here. So, if we are removing an event from the cache, is it intended to remove that from the {u,k}probe_events file as well?

No, it only deletes entries from the cache. No actual probes are removed.

Quoted 3 lines

The patch removes only from the cache (which I think is the intended behavior). With this patch, when I delete an event from the cache, it silently deletes it. So, do we add some kind of a message there?

Ah, good point!

Quoted 11 lines
# ./perf probe --cache --list
[kernel.kallsyms] (818a8e96766649cb2b62fc0bc3e66c27be0cd870):
vfs_read
/usr/lib64/libc-2.18.so (e8587f5d2edba244cc43368b5ebfce1782195b6f):
getaddrinfo $params
# ./perf probe --cache --del vfs_read\*
#

If we are silently removing the events from the cache, the commit message needs to be ammended.

Hmm, it must be dropped while updating series...

OK, I'll fix it!

Thanks!

Quoted 145 lines
Quoted 140 lines
   # perf probe --cache --list
   /[kernel.kallsyms] (1466a0a250b5d0070c6d0f03c5fed30b237970a1):
   /usr/lib64/libc-2.17.so (c31ffe7942bfd77b2fca8f9bd5709d387a86d3bc):
   getaddrinfo $params
   -----

---
Changes in v4:
- move del_perf_probe_caches() into builtin-probe.c since command-line related delete procedure is there now.

---
  tools/perf/Documentation/perf-probe.txt |    1 +
  tools/perf/builtin-probe.c              |   27 ++++++++++++++++++++++++++
  tools/perf/util/probe-file.c            |   32 ++++++++++++++++++++++++-------
  tools/perf/util/probe-file.h            |    2 ++
  4 files changed, 55 insertions(+), 7 deletions(-)
tools/perf/Documentation/perf-probe.txt +1 -0
index 5a70d45..8d09173 100644
@@ -116,6 +116,7 @@ OPTIONS
  	(With --add) Cache the probes. Any events which successfully added
  	are also stored in the cache file.
  	(With --list) Show cached probes.
+	(With --del) Remove cached probes.
 
  --max-probes=NUM::
  	Set the maximum number of probe points for an event. Default is 128.
tools/perf/builtin-probe.c +27 -0
index 53e380c0e..8f61525 100644
@@ -363,6 +363,30 @@ out_cleanup:
  	return ret;
  }
 
+static int del_perf_probe_caches(struct strfilter *filter)
+{
+	struct probe_cache *cache;
+	struct strlist *bidlist;
+	struct str_node *nd;
+	int ret;
+
+	ret = build_id_cache__list_all(&bidlist);
+	if (ret < 0) {
+		pr_debug("Failed to get buildids: %d\n", ret);
+		return ret;
+	}
+
+	strlist__for_each(nd, bidlist) {
+		cache = probe_cache__new(nd->s);
+		if (!cache)
+			continue;
+		probe_cache__remove_entries(cache, filter);
+		probe_cache__commit(cache);
+		probe_cache__delete(cache);
+	}
+	return 0;
+}
+
  static int perf_del_probe_events(struct strfilter *filter)
  {
  	int ret, ret2, ufd = -1, kfd = -1;
@@ -375,6 +399,9 @@ static int perf_del_probe_events(struct strfilter *filter)
 
  	pr_debug("Delete filter: \'%s\'\n", str);
 
+	if (probe_conf.cache)
+		return del_perf_probe_caches(filter);
+
  	/* Get current event names */
  	ret = probe_file__open_both(&kfd, &ufd, PF_FL_RW);
  	if (ret < 0)
tools/perf/util/probe-file.c +25 -7
index a6d4a67..cc0f183 100644
@@ -660,19 +660,37 @@ out:
  	return ret;
  }
 
+static bool probe_cache_entry__compare(struct probe_cache_entry *entry,
+				       struct strfilter *filter)
+{
+	char buf[128], *ptr = entry->spev;
+
+	if (entry->pev.event) {
+		snprintf(buf, 128, "%s:%s", entry->pev.group, entry->pev.event);
+		ptr = buf;
+	}
+	return strfilter__compare(filter, ptr);
+}
+
+int probe_cache__remove_entries(struct probe_cache *pcache,
+				struct strfilter *filter)
+{
+	struct probe_cache_entry *entry, *tmp;
+
+	list_for_each_entry_safe(entry, tmp, &pcache->list, list) {
+		if (probe_cache_entry__compare(entry, filter))
+			probe_cache_entry__delete(entry);
+	}
+	return 0;
+}
+
  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->list, list) {
-		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))
+		if (probe_cache_entry__compare(entry, filter))
  			printf("%s\n", entry->spev);
  	}
  	return 0;
tools/perf/util/probe-file.h +2 -0
index ac70446..e6fd9b9 100644
@@ -37,6 +37,8 @@ int probe_cache__add_entry(struct probe_cache *pcache,
  			   struct probe_trace_event *tevs, int ntevs);
  int probe_cache__commit(struct probe_cache *pcache);
  void probe_cache__delete(struct probe_cache *pcache);
+int probe_cache__remove_entries(struct probe_cache *pcache,
+				struct strfilter *filter);
  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,
Signature · 2 lines
Thanks,
Hemant Kumar
Signature · 1 line
Masami Hiramatsu <[email protected]>
#12 lore raw

PATCH v8 8/16 perf/sdt: ELF support for SDT

In reply to Masami Hiramatsu

From: Hemant Kumar <[email protected]>

This patch serves the initial support to identify and list SDT events in binaries. When programs containing SDT markers are compiled, gcc with the help of assembler directives identifies them and places them in the section ".note.stapsdt". To find these markers from the binaries, one needs to traverse through this section and parse the relevant details like the name, type and location of the marker. Also, the original location could be skewed due to the effect of prelinking. If that is the case, the locations need to be adjusted.

The functions in this patch open a given ELF, find out the SDT section, parse the relevant details, adjust the location (if necessary) and populate them in a list.

A typical note entry in ".note.stapsdt" section is as follows :

|--nhdr.n_namesz--|
------------------------------------
| nhdr | "stapsdt" |
----- |----------------------------------|
| | <location> <base_address> |
| | <semaphore> |

nhdr.n_descsize |  "provider_name"   "note_name"   |
         |      |   <args>                         |
        -----   |----------------------------------|
                |      nhdr      |     "stapsdt"   |
                |...

The above shows an excerpt from the section ".note.stapsdt". 'nhdr' is a structure which has the note name size (n_namesz), note description size (n_desc_sz) and note type (n_type). So, in order to parse the note note info, we need nhdr to tell us where to start from. As can be seen from <sys/sdt.h>, the name of the SDT notes given is "stapsdt". But this is not the identifier of the note.
After that, we go to description of the note to find out its location, the address of the ".stapsdt.base" section and the semaphore address. Then, we find the provider name and the SDT marker name and then follow the arguments.

---
 tools/perf/util/symbol-elf.c |  252 ++++++++++++++++++++++++++++++++++++++++++
 tools/perf/util/symbol.h     |   22 ++++
 2 files changed, 274 insertions(+)
tools/perf/util/symbol-elf.c +252 -0
index 87a297d..e74ce17 100644
@@ -1781,6 +1781,258 @@ void kcore_extract__delete(struct kcore_extract *kce)
 	unlink(kce->extract_filename);
 }
 
+/**
+ * populate_sdt_note : Parse raw data and identify SDT note
+ * @elf: elf of the opened file
+ * @data: raw data of a section with description offset applied
+ * @len: note description size
+ * @type: type of the note
+ * @sdt_notes: List to add the SDT note
+ *
+ * Responsible for parsing the @data in section .note.stapsdt in @elf and
+ * if its an SDT note, it appends to @sdt_notes list.
+ */
+static int populate_sdt_note(Elf **elf, const char *data, size_t len,
+			     struct list_head *sdt_notes)
+{
+	const char *provider, *name;
+	struct sdt_note *tmp = NULL;
+	GElf_Ehdr ehdr;
+	GElf_Addr base_off = 0;
+	GElf_Shdr shdr;
+	int ret = -EINVAL;
+
+	union {
+		Elf64_Addr a64[NR_ADDR];
+		Elf32_Addr a32[NR_ADDR];
+	} buf;
+
+	Elf_Data dst = {
+		.d_buf = &buf, .d_type = ELF_T_ADDR, .d_version = EV_CURRENT,
+		.d_size = gelf_fsize((*elf), ELF_T_ADDR, NR_ADDR, EV_CURRENT),
+		.d_off = 0, .d_align = 0
+	};
+	Elf_Data src = {
+		.d_buf = (void *) data, .d_type = ELF_T_ADDR,
+		.d_version = EV_CURRENT, .d_size = dst.d_size, .d_off = 0,
+		.d_align = 0
+	};
+
+	tmp = (struct sdt_note *)calloc(1, sizeof(struct sdt_note));
+	if (!tmp) {
+		ret = -ENOMEM;
+		goto out_err;
+	}
+
+	INIT_LIST_HEAD(&tmp->note_list);
+
+	if (len < dst.d_size + 3)
+		goto out_free_note;
+
+	/* Translation from file representation to memory representation */
+	if (gelf_xlatetom(*elf, &dst, &src,
+			  elf_getident(*elf, NULL)[EI_DATA]) == NULL) {
+		pr_err("gelf_xlatetom : %s\n", elf_errmsg(-1));
+		goto out_free_note;
+	}
+
+	/* Populate the fields of sdt_note */
+	provider = data + dst.d_size;
+
+	name = (const char *)memchr(provider, '\0', data + len - provider);
+	if (name++ == NULL)
+		goto out_free_note;
+
+	tmp->provider = strdup(provider);
+	if (!tmp->provider) {
+		ret = -ENOMEM;
+		goto out_free_note;
+	}
+	tmp->name = strdup(name);
+	if (!tmp->name) {
+		ret = -ENOMEM;
+		goto out_free_prov;
+	}
+
+	if (gelf_getclass(*elf) == ELFCLASS32) {
+		memcpy(&tmp->addr, &buf, 3 * sizeof(Elf32_Addr));
+		tmp->bit32 = true;
+	} else {
+		memcpy(&tmp->addr, &buf, 3 * sizeof(Elf64_Addr));
+		tmp->bit32 = false;
+	}
+
+	if (!gelf_getehdr(*elf, &ehdr)) {
+		pr_debug("%s : cannot get elf header.\n", __func__);
+		ret = -EBADF;
+		goto out_free_name;
+	}
+
+	/* Adjust the prelink effect :
+	 * Find out the .stapsdt.base section.
+	 * This scn will help us to handle prelinking (if present).
+	 * Compare the retrieved file offset of the base section with the
+	 * base address in the description of the SDT note. If its different,
+	 * then accordingly, adjust the note location.
+	 */
+	if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_BASE_SCN, NULL)) {
+		base_off = shdr.sh_offset;
+		if (base_off) {
+			if (tmp->bit32)
+				tmp->addr.a32[0] = tmp->addr.a32[0] + base_off -
+					tmp->addr.a32[1];
+			else
+				tmp->addr.a64[0] = tmp->addr.a64[0] + base_off -
+					tmp->addr.a64[1];
+		}
+	}
+
+	list_add_tail(&tmp->note_list, sdt_notes);
+	return 0;
+
+out_free_name:
+	free(tmp->name);
+out_free_prov:
+	free(tmp->provider);
+out_free_note:
+	free(tmp);
+out_err:
+	return ret;
+}
+
+/**
+ * construct_sdt_notes_list : constructs a list of SDT notes
+ * @elf : elf to look into
+ * @sdt_notes : empty list_head
+ *
+ * Scans the sections in 'elf' for the section
+ * .note.stapsdt. It, then calls populate_sdt_note to find
+ * out the SDT events and populates the 'sdt_notes'.
+ */
+static int construct_sdt_notes_list(Elf *elf, struct list_head *sdt_notes)
+{
+	GElf_Ehdr ehdr;
+	Elf_Scn *scn = NULL;
+	Elf_Data *data;
+	GElf_Shdr shdr;
+	size_t shstrndx, next;
+	GElf_Nhdr nhdr;
+	size_t name_off, desc_off, offset;
+	int ret = 0;
+
+	if (gelf_getehdr(elf, &ehdr) == NULL) {
+		ret = -EBADF;
+		goto out_ret;
+	}
+	if (elf_getshdrstrndx(elf, &shstrndx) != 0) {
+		ret = -EBADF;
+		goto out_ret;
+	}
+
+	/* Look for the required section */
+	scn = elf_section_by_name(elf, &ehdr, &shdr, SDT_NOTE_SCN, NULL);
+	if (!scn) {
+		ret = -ENOENT;
+		goto out_ret;
+	}
+
+	if ((shdr.sh_type != SHT_NOTE) || (shdr.sh_flags & SHF_ALLOC)) {
+		ret = -ENOENT;
+		goto out_ret;
+	}
+
+	data = elf_getdata(scn, NULL);
+
+	/* Get the SDT notes */
+	for (offset = 0; (next = gelf_getnote(data, offset, &nhdr, &name_off,
+					      &desc_off)) > 0; offset = next) {
+		if (nhdr.n_namesz == sizeof(SDT_NOTE_NAME) &&
+		    !memcmp(data->d_buf + name_off, SDT_NOTE_NAME,
+			    sizeof(SDT_NOTE_NAME))) {
+			/* Check the type of the note */
+			if (nhdr.n_type != SDT_NOTE_TYPE)
+				goto out_ret;
+
+			ret = populate_sdt_note(&elf, ((data->d_buf) + desc_off),
+						nhdr.n_descsz, sdt_notes);
+			if (ret < 0)
+				goto out_ret;
+		}
+	}
+	if (list_empty(sdt_notes))
+		ret = -ENOENT;
+
+out_ret:
+	return ret;
+}
+
+/**
+ * get_sdt_note_list : Wrapper to construct a list of sdt notes
+ * @head : empty list_head
+ * @target : file to find SDT notes from
+ *
+ * This opens the file, initializes
+ * the ELF and then calls construct_sdt_notes_list.
+ */
+int get_sdt_note_list(struct list_head *head, const char *target)
+{
+	Elf *elf;
+	int fd, ret;
+
+	fd = open(target, O_RDONLY);
+	if (fd < 0)
+		return -EBADF;
+
+	elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
+	if (!elf) {
+		ret = -EBADF;
+		goto out_close;
+	}
+	ret = construct_sdt_notes_list(elf, head);
+	elf_end(elf);
+out_close:
+	close(fd);
+	return ret;
+}
+
+/**
+ * cleanup_sdt_note_list : free the sdt notes' list
+ * @sdt_notes: sdt notes' list
+ *
+ * Free up the SDT notes in @sdt_notes.
+ * Returns the number of SDT notes free'd.
+ */
+int cleanup_sdt_note_list(struct list_head *sdt_notes)
+{
+	struct sdt_note *tmp, *pos;
+	int nr_free = 0;
+
+	list_for_each_entry_safe(pos, tmp, sdt_notes, note_list) {
+		list_del(&pos->note_list);
+		free(pos->name);
+		free(pos->provider);
+		free(pos);
+		nr_free++;
+	}
+	return nr_free;
+}
+
+/**
+ * sdt_notes__get_count: Counts the number of sdt events
+ * @start: list_head to sdt_notes list
+ *
+ * Returns the number of SDT notes in a list
+ */
+int sdt_notes__get_count(struct list_head *start)
+{
+	struct sdt_note *sdt_ptr;
+	int count = 0;
+
+	list_for_each_entry(sdt_ptr, start, note_list)
+		count++;
+	return count;
+}
+
 void symbol__elf_init(void)
 {
 	elf_version(EV_CURRENT);
tools/perf/util/symbol.h +22 -0
index 25f2fd67..9f9003e 100644
@@ -338,4 +338,26 @@ void arch__sym_update(struct symbol *s, GElf_Sym *sym);
 
 int arch__choose_best_symbol(struct symbol *syma, struct symbol *symb);
 
+/* structure containing an SDT note's info */
+struct sdt_note {
+	char *name;			/* name of the note*/
+	char *provider;			/* provider name */
+	bool bit32;			/* whether the location is 32 bits? */
+	union {				/* location, base and semaphore addrs */
+		Elf64_Addr a64[3];
+		Elf32_Addr a32[3];
+	} addr;
+	struct list_head note_list;	/* SDT notes' list */
+};
+
+int get_sdt_note_list(struct list_head *head, const char *target);
+int cleanup_sdt_note_list(struct list_head *sdt_notes);
+int sdt_notes__get_count(struct list_head *start);
+
+#define SDT_BASE_SCN ".stapsdt.base"
+#define SDT_NOTE_SCN  ".note.stapsdt"
+#define SDT_NOTE_TYPE 3
+#define SDT_NOTE_NAME "stapsdt"
+#define NR_ADDR 3
+
 #endif /* __PERF_SYMBOL */
#13 lore raw

PATCH v8 9/16 perf probe: Add group name support

In reply to Masami Hiramatsu

From: Masami Hiramatsu <[email protected]>

Allow user to set group name for adding new event. Note that user must ensure that the group name doesn't conflict with existing group name carefully. E.g. Existing group name can conflict with other events. Especially, using the group name reserved for kernel modules can hide kernel embedded events when loading modules.

---
Changes in v4:
- Update Documentation/perf-probe.txt too.

---
 tools/perf/Documentation/perf-probe.txt |   10 ++++++----
 tools/perf/util/probe-event.c           |   23 ++++++++++++++---------
 2 files changed, 20 insertions(+), 13 deletions(-)
tools/perf/Documentation/perf-probe.txt +6 -4
index 8d09173..7a258e9 100644
@@ -143,16 +143,18 @@ PROBE SYNTAX
 Probe points are defined by following syntax.
 
     1) Define event based on function name
-     [EVENT=]FUNC[@SRC][:RLN|+OFFS|%return|;PTN] [ARG ...]
+     [[GROUP:]EVENT=]FUNC[@SRC][:RLN|+OFFS|%return|;PTN] [ARG ...]
 
     2) Define event based on source file with line number
-     [EVENT=]SRC:ALN [ARG ...]
+     [[GROUP:]EVENT=]SRC:ALN [ARG ...]
 
     3) Define event based on source file with lazy pattern
-     [EVENT=]SRC;PTN [ARG ...]
+     [[GROUP:]EVENT=]SRC;PTN [ARG ...]
 
 
-'EVENT' specifies the name of new event, if omitted, it will be set the name of the probed function. Currently, event group name is set as 'probe'.
+'EVENT' specifies the name of new event, if omitted, it will be set the name of the probed function. You can also specify a group name by 'GROUP', if omitted, set 'probe' is used for kprobe and 'probe_<bin>' is used for uprobe.
+Note that using existing group name can conflict with other events. Especially, using the group name reserved for kernel modules can hide embedded events in the
+modules.
 'FUNC' specifies a probed function name, and it may have one of the following options; '+OFFS' is the offset from function entry address in bytes, ':RLN' is the relative-line number from function entry line, and '%return' means that it probes function return. And ';PTN' means lazy matching pattern (see LAZY MATCHING). Note that ';PTN' must be the end of the probe point definition.  In addition, '@SRC' specifies a source file which has that function.
 It is also possible to specify a probe point by the source line number or lazy matching by using 'SRC:ALN' or 'SRC;PTN' syntax, where 'SRC' is the source file path, ':ALN' is the line number and ';PTN' is the lazy matching pattern.
 'ARG' specifies the arguments of this probe point, (see PROBE ARGUMENT).
tools/perf/util/probe-event.c +14 -9
index 57fd657..79da841 100644
@@ -1208,10 +1208,8 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
 	bool file_spec = false;
 	/*
 	 * <Syntax>
-	 * perf probe [EVENT=]SRC[:LN|;PTN]
-	 * perf probe [EVENT=]FUNC[@SRC][+OFFS|%return|:LN|;PAT]
-	 *
-	 * TODO:Group name support
+	 * perf probe [GRP:][EVENT=]SRC[:LN|;PTN]
+	 * perf probe [GRP:][EVENT=]FUNC[@SRC][+OFFS|%return|:LN|;PAT]
 	 */
 	if (!arg)
 		return -EINVAL;
@@ -1220,11 +1218,19 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
 	if (ptr && *ptr == '=') {	/* Event name */
 		*ptr = '\0';
 		tmp = ptr + 1;
-		if (strchr(arg, ':')) {
-			semantic_error("Group name is not supported yet.\n");
-			return -ENOTSUP;
-		}
+		ptr = strchr(arg, ':');
+		if (ptr) {
+			*ptr = '\0';
+			if (!is_c_func_name(arg))
+				goto not_fname;
+			pev->group = strdup(arg);
+			if (!pev->group)
+				return -ENOMEM;
+			arg = ptr + 1;
+		} else
+			pev->group = NULL;
 		if (!is_c_func_name(arg)) {
+not_fname:
 			semantic_error("%s is bad for event name -it must "
 				       "follow C symbol-naming rule.\n", arg);
 			return -EINVAL;
@@ -1232,7 +1238,6 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
 		pev->event = strdup(arg);
 		if (pev->event == NULL)
 			return -ENOMEM;
-		pev->group = NULL;
 		arg = tmp;
 	}
 
#14 lore raw

PATCH v8 10/16 perf buildid-cache: Scan and import user SDT events to probe cache

In reply to Masami Hiramatsu

From: Masami Hiramatsu <[email protected]>

perf buildid-cache --add <binary> scans given binary and add the SDT events to probe cache. "sdt_" prefix is appended for all SDT providers to avoid event-name clash with other pre-defined events. It is possible to use the cached SDT events as other cached events, via perf probe --add "sdt_<provider>:<event>=<event>".

e.g.
----

  # perf buildid-cache --add /lib/libc-2.17.so
  # perf probe --cache --list | head -n 5
  /usr/lib/libc-2.17.so (a6fb821bdf53660eb2c29f778757aef294d3d392):
  sdt_libc:setjmp=setjmp
  sdt_libc:longjmp=longjmp
  sdt_libc:longjmp_target=longjmp_target
  sdt_libc:memory_heap_new=memory_heap_new
  # perf probe -x /usr/lib/libc-2.17.so \
    -a sdt_libc:memory_heap_new=memory_heap_new
  Added new event:
    sdt_libc:memory_heap_new (on memory_heap_new
   in /usr/lib/libc-2.17.so)

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

perf record -e sdt_libc:memory_heap_new -aR sleep 1

  # perf probe -l
    sdt_libc:memory_heap_new (on new_heap+183 in /usr/lib/libc-2.17.so)
  ----

Note that SDT event entries in probe-cache file is somewhat different from normal cached events. Normal one starts with "#", but SDTs are starting with "%".

---
Changes in v4:
- Fix a bug to copy correct group name to entries.
- Fix to consolidate same-name entries.

---
 tools/perf/util/build-id.c   |   27 +++++++++++++++--
 tools/perf/util/probe-file.c |   67 ++++++++++++++++++++++++++++++++++++++++--
 tools/perf/util/probe-file.h |    2 +
 3 files changed, 90 insertions(+), 6 deletions(-)
tools/perf/util/build-id.c +24 -3
index 14fbd37..68a67eb 100644
@@ -17,6 +17,7 @@
 #include "tool.h"
 #include "header.h"
 #include "vdso.h"
+#include "probe-file.h"
 
 
 static bool no_buildid_cache;
@@ -513,6 +514,23 @@ int build_id_cache__list_build_ids(const char *pathname,
 	return ret;
 }
 
+#ifdef HAVE_LIBELF_SUPPORT
+static void build_id_cache__add_sdt_cache(const char *sbuild_id,
+					  const char *realname)
+{
+	struct probe_cache *cache;
+
+	cache = probe_cache__new(sbuild_id);
+	if (!cache)
+		return;
+	if (probe_cache__scan_sdt(cache, realname) >= 0)
+		probe_cache__commit(cache);
+	probe_cache__delete(cache);
+}
+#else
+#define build_id_cache__add_sdt_cache(sbuild_id, realname) do { } while (0)
+#endif
+
 int build_id_cache__add_s(const char *sbuild_id, const char *name,
 			  bool is_kallsyms, bool is_vdso)
 {
@@ -556,20 +574,23 @@ int build_id_cache__add_s(const char *sbuild_id, const char *name,
 			goto out_free;
 	}
 
+	/* Make a symbolic link */
 	if (!build_id_cache__linkname(sbuild_id, linkname, size))
 		goto out_free;
+
 	tmp = strrchr(linkname, '/');
 	*tmp = '\0';
-
 	if (access(linkname, X_OK) && mkdir_p(linkname, 0755))
 		goto out_free;
-
 	*tmp = '/';
 	tmp = dir_name + strlen(buildid_dir) - 5;
 	memcpy(tmp, "../..", 5);
-
 	if (symlink(tmp, linkname) == 0)
 		err = 0;
+
+	/* Update SDT cache */
+	build_id_cache__add_sdt_cache(sbuild_id, realname);
+
 out_free:
 	if (!is_kallsyms)
 		free(realname);
tools/perf/util/probe-file.c +64 -3

90 lines not on this page · raw message

tools/perf/util/probe-file.h +2 -0
index e6fd9b9..93aa193 100644
@@ -8,6 +8,7 @@
 /* Cache of probe definitions */
 struct probe_cache_entry {
 	struct list_head	list;
+	bool			sdt;
 	struct perf_probe_event pev;
 	char			*spev;
 	struct strlist		*tevlist;
@@ -35,6 +36,7 @@ struct probe_cache *probe_cache__new(const char *target);
 int probe_cache__add_entry(struct probe_cache *pcache,
 			   struct perf_probe_event *pev,
 			   struct probe_trace_event *tevs, int ntevs);
+int probe_cache__scan_sdt(struct probe_cache *pcache, const char *pathname);
 int probe_cache__commit(struct probe_cache *pcache);
 void probe_cache__delete(struct probe_cache *pcache);
 int probe_cache__remove_entries(struct probe_cache *pcache,
#15 lore raw

PATCH v8 11/16 perf probe: Accept %sdt and %cached event name

In reply to Masami Hiramatsu

From: Masami Hiramatsu <[email protected]>

To improbe usability, support %[PROVIDER:]SDTEVENT format to add new probes on SDT and cached events.

e.g.
----

  # perf probe -x /lib/libc-2.17.so  %lll_lock_wait_private
  Added new event:
    sdt_libc:lll_lock_wait_private (on %lll_lock_wait_private in
  /usr/lib/libc-2.17.so)

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

perf record -e sdt_libc:lll_lock_wait_private -aR sleep 1

  # perf probe -l | more
    sdt_libc:lll_lock_wait_private (on __lll_lock_wait_private+21
   in /usr/lib/libc-2.17.so)
  ----

Note that this is not only for SDT events, but also normal events with event-name.

e.g. define "myevent" on cache (-n doesn't add the real probe)
----

  # perf probe -x ./perf --cache -n --add 'myevent=dso__load $params'
  ----
  Reuse the "myevent" from cache as below.
  ----
  # perf probe -x ./perf %myevent
  ----

---
Changes in v7:
- Fix a bug to return an error if no SDT/cached events found in cache.

---
 tools/perf/Documentation/perf-probe.txt |    3 +
 tools/perf/util/probe-event.c           |   82 ++++++++++++++++++++++---------
 tools/perf/util/probe-event.h           |    1 
 tools/perf/util/probe-file.c            |    9 +++
 4 files changed, 71 insertions(+), 24 deletions(-)
tools/perf/Documentation/perf-probe.txt +3 -0
index 7a258e9..43523be 100644
@@ -151,6 +151,8 @@ Probe points are defined by following syntax.
     3) Define event based on source file with lazy pattern
      [[GROUP:]EVENT=]SRC;PTN [ARG ...]
 
+    4) Pre-defined SDT events
+     %[PROVIDER:]SDTEVENT
 
 'EVENT' specifies the name of new event, if omitted, it will be set the name of the probed function. You can also specify a group name by 'GROUP', if omitted, set 'probe' is used for kprobe and 'probe_<bin>' is used for uprobe.
 Note that using existing group name can conflict with other events. Especially, using the group name reserved for kernel modules can hide embedded events in the
@@ -158,6 +160,7 @@ modules.
 'FUNC' specifies a probed function name, and it may have one of the following options; '+OFFS' is the offset from function entry address in bytes, ':RLN' is the relative-line number from function entry line, and '%return' means that it probes function return. And ';PTN' means lazy matching pattern (see LAZY MATCHING). Note that ';PTN' must be the end of the probe point definition.  In addition, '@SRC' specifies a source file which has that function.
 It is also possible to specify a probe point by the source line number or lazy matching by using 'SRC:ALN' or 'SRC;PTN' syntax, where 'SRC' is the source file path, ':ALN' is the line number and ';PTN' is the lazy matching pattern.
 'ARG' specifies the arguments of this probe point, (see PROBE ARGUMENT).
+'SDTEVENT' and 'PROVIDER' is the pre-defined event name which is defined by user SDT (Statically Defined Tracing) or the pre-cached probes with event name.
 
 PROBE ARGUMENT
 --------------
tools/perf/util/probe-event.c +58 -24

124 lines not on this page · raw message

tools/perf/util/probe-event.h +1 -0
index 432b690..e18ea9f 100644
@@ -85,6 +85,7 @@ struct perf_probe_event {
 	char			*group;	/* Group name */
 	struct perf_probe_point	point;	/* Probe point */
 	int			nargs;	/* Number of arguments */
+	bool			sdt;	/* SDT/cached event flag */
 	bool			uprobes;	/* Uprobe event flag */
 	char			*target;	/* Target binary */
 	struct perf_probe_arg	*args;	/* Arguments */
tools/perf/util/probe-file.c +9 -0
index da241ed..bc82a55 100644
@@ -538,6 +538,15 @@ probe_cache__find(struct probe_cache *pcache, struct perf_probe_event *pev)
 		return NULL;
 
 	list_for_each_entry(entry, &pcache->list, list) {
+		if (pev->sdt) {
+			if (entry->pev.event &&
+			    streql(entry->pev.event, pev->event) &&
+			    (!pev->group ||
+			     streql(entry->pev.group, pev->group)))
+				goto found;
+
+			continue;
+		}
 		/* Hit if same event name or same command-string */
 		if ((pev->event &&
 		     (streql(entry->pev.group, pev->group) &&
#16 lore raw

PATCH v8 12/16 perf-list: Show SDT and pre-cached events

In reply to Masami Hiramatsu

From: Masami Hiramatsu <[email protected]>

Show SDT and pre-cached events by perf-list with "sdt". This also shows the binary and build-id where the events are placed only when there are same name events on different binaries. e.g.
----

  # perf list sdt

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

    sdt_libc:lll_futex_wake                            [SDT event]
    sdt_libc:lll_lock_wait_private                     [SDT event]
    sdt_libc:longjmp                                   [SDT event]
    sdt_libc:longjmp_target                            [SDT event]
  ...
    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)

----

The binary path and build-id are shown in below format;

<GROUP>:<EVENT>@<PATH>(<BUILD-ID>)

---
Changes in v5:
- Fix a build error for minimal option.

Changes in v4:
- Update patch description.
- Change event list format.

---
 tools/perf/builtin-list.c      |    4 ++
 tools/perf/util/parse-events.c |   83 ++++++++++++++++++++++++++++++++++++++++
 tools/perf/util/parse-events.h |    2 +
 tools/perf/util/probe-file.h   |    9 ++++
 4 files changed, 98 insertions(+)
tools/perf/builtin-list.c +4 -0
index 5e22db4..3cba865 100644
@@ -62,6 +62,8 @@ int cmd_list(int argc, const char **argv, const char *prefix __maybe_unused)
 			print_hwcache_events(NULL, raw_dump);
 		else if (strcmp(argv[i], "pmu") == 0)
 			print_pmu_events(NULL, raw_dump);
+		else if (strcmp(argv[i], "sdt") == 0)
+			print_sdt_events(NULL, NULL, raw_dump);
 		else if ((sep = strchr(argv[i], ':')) != NULL) {
 			int sep_idx;
 
@@ -76,6 +78,7 @@ int cmd_list(int argc, const char **argv, const char *prefix __maybe_unused)
 
 			s[sep_idx] = '\0';
 			print_tracepoint_events(s, s + sep_idx + 1, raw_dump);
+			print_sdt_events(s, s + sep_idx + 1, raw_dump);
 			free(s);
 		} else {
 			if (asprintf(&s, "*%s*", argv[i]) < 0) {
@@ -89,6 +92,7 @@ int cmd_list(int argc, const char **argv, const char *prefix __maybe_unused)
 			print_hwcache_events(s, raw_dump);
 			print_pmu_events(s, raw_dump);
 			print_tracepoint_events(NULL, s, raw_dump);
+			print_sdt_events(NULL, s, raw_dump);
 			free(s);
 		}
 	}
tools/perf/util/parse-events.c +83 -0

101 lines not on this page · raw message

tools/perf/util/parse-events.h +2 -0
index d740c3c..c08daa9 100644
@@ -182,6 +182,8 @@ void print_symbol_events(const char *event_glob, unsigned type,
 void print_tracepoint_events(const char *subsys_glob, const char *event_glob,
 			     bool name_only);
 int print_hwcache_events(const char *event_glob, bool name_only);
+void print_sdt_events(const char *subsys_glob, const char *event_glob,
+		      bool name_only);
 int is_valid_tracepoint(const char *event_string);
 
 int valid_event_mount(const char *eventfs);
tools/perf/util/probe-file.h +9 -0
index 93aa193..ce98162 100644
@@ -22,6 +22,8 @@ struct probe_cache {
 #define PF_FL_UPROBE	1
 #define PF_FL_RW	2
 
+/* probe-file.c depends on libelf */
+#ifdef HAVE_LIBELF_SUPPORT
 int probe_file__open(int flag);
 int probe_file__open_both(int *kfd, int *ufd, int flag);
 struct strlist *probe_file__get_namelist(int fd);
@@ -46,4 +48,11 @@ struct probe_cache_entry *probe_cache__find(struct probe_cache *pcache,
 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);
+#else	/* ! HAVE_LIBELF_SUPPORT */
+static inline struct probe_cache *probe_cache__new(const char *tgt __maybe_unused)
+{
+	return NULL;
+}
+#define probe_cache__delete(pcache) do {} while(0)
+#endif
 #endif
#17 lore raw

Re: [PATCH perf/core v8 12/16] perf-list: Show SDT and pre-cached events

Quoted 47 lines · Masami Hiramatsu

From: Masami Hiramatsu <[email protected]>

Show SDT and pre-cached events by perf-list with "sdt". This also shows the binary and build-id where the events are placed only when there are same name events on different binaries. e.g.
----

   # perf list sdt
   List of pre-defined events (to be used in -e):

     sdt_libc:lll_futex_wake                            [SDT event]
     sdt_libc:lll_lock_wait_private                     [SDT event]
     sdt_libc:longjmp                                   [SDT event]
     sdt_libc:longjmp_target                            [SDT event]
   ...
     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)
   ----

The binary path and build-id are shown in below format;

   <GROUP>:<EVENT>@<PATH>(<BUILD-ID>)

---
Changes in v5:
- Fix a build error for minimal option.

Changes in v4:
- Update patch description.
- Change event list format.

---
  tools/perf/builtin-list.c      |    4 ++
  tools/perf/util/parse-events.c |   83 ++++++++++++++++++++++++++++++++++++++++
  tools/perf/util/parse-events.h |    2 +
  tools/perf/util/probe-file.h   |    9 ++++
  4 files changed, 98 insertions(+)
tools/perf/builtin-list.c +0 -0
index 5e22db4..3cba865 100644

tools/perf/builtin-list.c int cmd_list(int argc, const char **argv, const char *prefix __maybe_unused) · line 66

Quoted 5 lines
tools/perf/builtin-list.c +2 -0
@@ -62,6 +62,8 @@ int cmd_list(int argc, const char **argv, const char *prefix __maybe_unused)
  			print_hwcache_events(NULL, raw_dump);
  		else if (strcmp(argv[i], "pmu") == 0)
  			print_pmu_events(NULL, raw_dump);
+		else if (strcmp(argv[i], "sdt") == 0)
+			print_sdt_events(NULL, NULL, raw_dump);

We will also need to add "sdt" to list_usage[] variable in this function :
const char * const list_usage[] = {
"perf list [hw|sw|cache|tracepoint|pmu|sdt|event_glob]",
NULL

        };
Quoted 166 lines
tools/perf/builtin-list.c +2 -0
  		else if ((sep = strchr(argv[i], ':')) != NULL) {
  			int sep_idx;
 
@@ -76,6 +78,7 @@ int cmd_list(int argc, const char **argv, const char *prefix __maybe_unused)
 
  			s[sep_idx] = '\0';
  			print_tracepoint_events(s, s + sep_idx + 1, raw_dump);
+			print_sdt_events(s, s + sep_idx + 1, raw_dump);
  			free(s);
  		} else {
  			if (asprintf(&s, "*%s*", argv[i]) < 0) {
@@ -89,6 +92,7 @@ int cmd_list(int argc, const char **argv, const char *prefix __maybe_unused)
  			print_hwcache_events(s, raw_dump);
  			print_pmu_events(s, raw_dump);
  			print_tracepoint_events(NULL, s, raw_dump);
+			print_sdt_events(NULL, s, raw_dump);
  			free(s);
  		}
  	}
tools/perf/util/parse-events.c +83 -0
index bcbc983..f9c8b7b 100644
@@ -20,6 +20,7 @@
  #include "pmu.h"
  #include "thread_map.h"
  #include "cpumap.h"
+#include "probe-file.h"
  #include "asm/bug.h"
 
  #define MAX_NAME_LEN 100
@@ -1976,6 +1977,86 @@ static bool is_event_supported(u8 type, unsigned config)
  	return ret;
  }
 
+void print_sdt_events(const char *subsys_glob, const char *event_glob,
+		      bool name_only)
+{
+	struct probe_cache *pcache;
+	struct probe_cache_entry *ent;
+	struct strlist *bidlist, *sdtlist;
+	struct strlist_config cfg = {.dont_dupstr = true};
+	struct str_node *nd, *nd2;
+	char *buf, *path, *ptr = NULL;
+	bool show_detail = false;
+	int ret;
+
+	sdtlist = strlist__new(NULL, &cfg);
+	if (!sdtlist) {
+		pr_debug("Failed to allocate new strlist for SDT\n");
+		return;
+	}
+	ret = build_id_cache__list_all(&bidlist);
+	if (ret < 0) {
+		pr_debug("Failed to get buildids: %d\n", ret);
+		return;
+	}
+	strlist__for_each(nd, bidlist) {
+		pcache = probe_cache__new(nd->s);
+		if (!pcache)
+			continue;
+		if (!list_empty(&pcache->list))
+			list_for_each_entry(ent, &pcache->list, list) {
+				if (!ent->sdt)
+					continue;
+				if (subsys_glob &&
+				    !strglobmatch(ent->pev.group, subsys_glob))
+					continue;
+				if (event_glob &&
+				    !strglobmatch(ent->pev.event, event_glob))
+					continue;
+				ret = asprintf(&buf, "%s:%s@%s", ent->pev.group,
+						ent->pev.event, nd->s);
+				if (ret > 0)
+					strlist__add(sdtlist, buf);
+			}
+		probe_cache__delete(pcache);
+	}
+	strlist__delete(bidlist);
+
+	strlist__for_each(nd, sdtlist) {
+		buf = strchr(nd->s, '@');
+		if (buf)
+			*(buf++) = '\0';
+		if (name_only) {
+			printf("%s ", nd->s);
+			continue;
+		}
+		nd2 = strlist__next(nd);
+		if (nd2) {
+			ptr = strchr(nd2->s, '@');
+			if (ptr)
+				*ptr = '\0';
+			if (strcmp(nd->s, nd2->s) == 0)
+				show_detail = true;
+		}
+		if (show_detail) {
+			path = build_id_cache__origname(buf);
+			ret = asprintf(&buf, "%s@%s(%.12s)", nd->s, path, buf);
+			if (ret > 0) {
+				printf("  %-50s [%s]\n", buf, "SDT event");
+				free(buf);
+			}
+		} else
+			printf("  %-50s [%s]\n", nd->s, "SDT event");
+		if (nd2) {
+			if (strcmp(nd->s, nd2->s) != 0)
+				show_detail = false;
+			if (ptr)
+				*ptr = '@';
+		}
+	}
+	strlist__delete(sdtlist);
+}
+
  int print_hwcache_events(const char *event_glob, bool name_only)
  {
  	unsigned int type, op, i, evt_i = 0, evt_num = 0;
@@ -2158,6 +2239,8 @@ void print_events(const char *event_glob, bool name_only)
  	}
 
  	print_tracepoint_events(NULL, NULL, name_only);
+
+	print_sdt_events(NULL, NULL, name_only);
  }
 
  int parse_events__is_hardcoded_term(struct parse_events_term *term)
tools/perf/util/parse-events.h +2 -0
index d740c3c..c08daa9 100644
@@ -182,6 +182,8 @@ void print_symbol_events(const char *event_glob, unsigned type,
  void print_tracepoint_events(const char *subsys_glob, const char *event_glob,
  			     bool name_only);
  int print_hwcache_events(const char *event_glob, bool name_only);
+void print_sdt_events(const char *subsys_glob, const char *event_glob,
+		      bool name_only);
  int is_valid_tracepoint(const char *event_string);
 
  int valid_event_mount(const char *eventfs);
tools/perf/util/probe-file.h +9 -0
index 93aa193..ce98162 100644
@@ -22,6 +22,8 @@ struct probe_cache {
  #define PF_FL_UPROBE	1
  #define PF_FL_RW	2
 
+/* probe-file.c depends on libelf */
+#ifdef HAVE_LIBELF_SUPPORT
  int probe_file__open(int flag);
  int probe_file__open_both(int *kfd, int *ufd, int flag);
  struct strlist *probe_file__get_namelist(int fd);
@@ -46,4 +48,11 @@ struct probe_cache_entry *probe_cache__find(struct probe_cache *pcache,
  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);
+#else	/* ! HAVE_LIBELF_SUPPORT */
+static inline struct probe_cache *probe_cache__new(const char *tgt __maybe_unused)
+{
+	return NULL;
+}
+#define probe_cache__delete(pcache) do {} while(0)
+#endif
  #endif
Signature · 2 lines
Thanks,
Hemant Kumar
#18 lore raw

PATCH v8 13/16 perf-list: Skip SDTs placed in invalid binaries

In reply to Masami Hiramatsu

From: Masami Hiramatsu <[email protected]>

Skip SDTs placed in invalid (non-exist, or older version) binaries. Note that perf-probe --cache --list and perf-probe --cache --del still handle all the caches including invalid binaries.

---
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/parse-events.c |    2 +-
 tools/perf/util/probe-file.c   |    2 +-
 5 files changed, 36 insertions(+), 5 deletions(-)
tools/perf/builtin-probe.c +1 -1
index 8f61525..4a86aea 100644
@@ -370,7 +370,7 @@ static int del_perf_probe_caches(struct strfilter *filter)
 	struct str_node *nd;
 	int ret;
 
-	ret = build_id_cache__list_all(&bidlist);
+	ret = build_id_cache__list_all(&bidlist, false);
 	if (ret < 0) {
 		pr_debug("Failed to get buildids: %d\n", ret);
 		return ret;
tools/perf/util/build-id.c +32 -1
index 68a67eb..424f4e2 100644
@@ -209,6 +209,31 @@ 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");
@@ -420,7 +445,7 @@ void disable_buildid_cache(void)
 	no_buildid_cache = true;
 }
 
-int build_id_cache__list_all(struct strlist **result)
+int build_id_cache__list_all(struct strlist **result, bool validonly)
 {
 	struct strlist *toplist, *list, *bidlist;
 	struct str_node *nd, *nd2;
@@ -428,6 +453,10 @@ int build_id_cache__list_all(struct strlist **result)
 	char sbuild_id[SBUILD_ID_SIZE];
 	int ret = 0;
 
+	/* for filename__ functions */
+	if (validonly)
+		symbol__init(NULL);
+
 	/* Open the top-level directory */
 	if (asprintf(&topdir, "%s/.build-id/", buildid_dir) < 0)
 		return -errno;
@@ -457,6 +486,8 @@ int build_id_cache__list_all(struct strlist **result)
 					nd->s, nd2->s);
 				continue;
 			}
+			if (validonly && !build_id_cache__valid_id(sbuild_id))
+				continue;
 			strlist__add(bidlist, sbuild_id);
 		}
 		strlist__delete(list);
tools/perf/util/build-id.h +1 -1
index c05503e..480600b 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);
-int build_id_cache__list_all(struct strlist **result);
+int build_id_cache__list_all(struct strlist **result, 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/parse-events.c +1 -1
index f9c8b7b..53d52a3 100644
@@ -1994,7 +1994,7 @@ void print_sdt_events(const char *subsys_glob, const char *event_glob,
 		pr_debug("Failed to allocate new strlist for SDT\n");
 		return;
 	}
-	ret = build_id_cache__list_all(&bidlist);
+	ret = build_id_cache__list_all(&bidlist, true);
 	if (ret < 0) {
 		pr_debug("Failed to get buildids: %d\n", ret);
 		return;
tools/perf/util/probe-file.c +1 -1
index bc82a55..c4104c4 100644
@@ -779,7 +779,7 @@ int probe_cache__show_all_caches(struct strfilter *filter)
 	pr_debug("list cache with filter: %s\n", buf);
 	free(buf);
 
-	ret = build_id_cache__list_all(&bidlist);
+	ret = build_id_cache__list_all(&bidlist, false);
 	if (ret < 0) {
 		pr_debug("Failed to get buildids: %d\n", ret);
 		return ret == -ENOENT ? 0 : ret;
#19 lore raw

PATCH v8 14/16 perf probe: Allow wildcard for cached events

In reply to Masami Hiramatsu

Allo glob wildcard for reusing cached/SDT events. This also automatically find the target binaries, e.g.

  # perf probe -a %sdt_libc:\*

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

---
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 |  211 +++++++++++++++++++++++++++++++++++++----
 tools/perf/util/probe-event.h |    1 
 tools/perf/util/probe-file.c  |   46 +++++++--
 tools/perf/util/probe-file.h  |    5 +
 4 files changed, 232 insertions(+), 31 deletions(-)
tools/perf/util/probe-event.c +190 -21
index 5ec98b2..0019a22 100644
@@ -236,7 +236,7 @@ static void clear_perf_probe_point(struct perf_probe_point *pp)
 	free(pp->lazy_line);
 }
 
-static void clear_probe_trace_events(struct probe_trace_event *tevs, int ntevs)
+void clear_probe_trace_events(struct probe_trace_event *tevs, int ntevs)
 {
 	int i;
 
@@ -1206,7 +1206,7 @@ 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)
@@ -1214,7 +1214,7 @@ 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);
@@ -1640,6 +1640,11 @@ int parse_probe_trace_command(const char *cmd, struct probe_trace_event *tev)
 	p = strchr(argv[1], ':');
 	if (p) {
 		tp->module = strndup(argv[1], p - argv[1]);
+		if (!tp->module) {
+			ret = -ENOMEM;
+			goto out;
+		}
+		tev->uprobes = (tp->module[0] == '/');
 		p++;
 	} else
 		p = argv[1];
@@ -2514,7 +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;
@@ -2527,7 +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;
@@ -2552,41 +2557,60 @@ static int probe_trace_event__set_name(struct probe_trace_event *tev,
 	return 0;
 }
 
-static int __add_probe_trace_events(struct perf_probe_event *pev,
-				     struct probe_trace_event *tevs,
-				     int ntevs, bool allow_suffix)
+static int __open_probe_file_and_namelist(bool uprobe,
+					  struct strlist **namelist)
 {
-	int i, fd, ret;
-	struct probe_trace_event *tev = NULL;
-	struct probe_cache *cache = NULL;
-	struct strlist *namelist;
+	int fd;
 
-	fd = probe_file__open(PF_FL_RW | (pev->uprobes ? PF_FL_UPROBE : 0));
+	fd = probe_file__open(PF_FL_RW | (uprobe ? PF_FL_UPROBE : 0));
 	if (fd < 0)
 		return fd;
 
 	/* Get current event names */
-	namelist = probe_file__get_namelist(fd);
-	if (!namelist) {
+	*namelist = probe_file__get_namelist(fd);
+	if (!(*namelist)) {
 		pr_debug("Failed to get current event list.\n");
-		ret = -ENOMEM;
-		goto close_out;
+		close(fd);
+		return -ENOMEM;
 	}
+	return fd;
+}
+
+static int __add_probe_trace_events(struct perf_probe_event *pev,
+				     struct probe_trace_event *tevs,
+				     int ntevs, bool allow_suffix)
+{
+	int i, fd[2] = {-1, -1}, up, ret;
+	struct probe_trace_event *tev = NULL;
+	struct probe_cache *cache = NULL;
+	struct strlist *namelist[2] = {NULL, NULL};
+
+	up = pev->uprobes ? 1 : 0;
+	fd[up] = __open_probe_file_and_namelist(up, &namelist[up]);
+	if (fd[up] < 0)
+		return fd[up];
 
 	ret = 0;
 	for (i = 0; i < ntevs; i++) {
 		tev = &tevs[i];
+		up = tev->uprobes ? 1 : 0;
+		if (fd[up] == -1) {	/* Open the kprobe/uprobe_events */
+			fd[up] = __open_probe_file_and_namelist(up,
+								&namelist[up]);
+			if (fd[up] < 0)
+				goto close_out;
+		}
 		/* Skip if the symbol is out of .text or blacklisted */
 		if (!tev->point.symbol && !pev->uprobes)
 			continue;
 
 		/* Set new name for tev (and update namelist) */
-		ret = probe_trace_event__set_name(tev, pev, namelist,
+		ret = probe_trace_event__set_name(tev, pev, namelist[up],
 						  allow_suffix);
 		if (ret < 0)
 			break;
 
-		ret = probe_file__add_event(fd, tev);
+		ret = probe_file__add_event(fd[up], tev);
 		if (ret < 0)
 			break;
 
@@ -2609,9 +2633,12 @@ static int __add_probe_trace_events(struct perf_probe_event *pev,
 		}
 	}
 
-	strlist__delete(namelist);
 close_out:
-	close(fd);
+	for (up = 0; up < 2; up++) {
+		strlist__delete(namelist[up]);
+		if (fd[up] >= 0)
+			close(fd[up]);
+	}
 	return ret;
 }
 
@@ -2890,6 +2917,141 @@ 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[0] == '/')
+			pev->uprobes = true;
+	}
+
+	return ret;
+}
+
+/* Try to find probe_trace_event from all probe caches */
+static int find_cached_events_all(struct perf_probe_event *pev,
+				   struct probe_trace_event **tevs)
+{
+	struct probe_trace_event *tmp_tevs = NULL;
+	struct strlist *bidlist;
+	struct str_node *nd;
+	char *pathname;
+	int ntevs = 0;
+	int ret;
+
+	/* Get the buildid list of all valid caches */
+	ret = build_id_cache__list_all(&bidlist, true);
+	if (ret < 0) {
+		pr_debug("Failed to get buildids: %d\n", ret);
+		return ret;
+	}
+
+	ret = 0;
+	strlist__for_each(nd, bidlist) {
+		pathname = build_id_cache__origname(nd->s);
+		ret = find_cached_events(pev, &tmp_tevs, pathname);
+		/* In the case of cnt == 0, we just skip it */
+		if (ret > 0)
+			ret = concat_probe_trace_events(tevs, &ntevs,
+							&tmp_tevs, ret);
+		free(pathname);
+		if (ret < 0)
+			break;
+	}
+	strlist__delete(bidlist);
+
+	if (ret < 0) {
+		clear_probe_trace_events(*tevs, ntevs);
+		zfree(tevs);
+	} else
+		ret = ntevs;
+
+	return ret;
+}
+
 static int find_probe_trace_events_from_cache(struct perf_probe_event *pev,
 					      struct probe_trace_event **tevs)
 {
@@ -2899,6 +3061,13 @@ 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 */
+		if (!pev->target)
+			return find_cached_events_all(pev, tevs);
+		else
+			return find_cached_events(pev, tevs, pev->target);
+	}
 	cache = probe_cache__new(pev->target);
 	if (!cache)
 		return 0;
tools/perf/util/probe-event.h +1 -0
index e18ea9f..a027bfe 100644
@@ -134,6 +134,7 @@ bool perf_probe_event_need_dwarf(struct perf_probe_event *pev);
 /* Release event contents */
 void clear_perf_probe_event(struct perf_probe_event *pev);
 void clear_probe_trace_event(struct probe_trace_event *tev);
+void clear_probe_trace_events(struct probe_trace_event *tevs, int ntevs);
 
 /* Command string to line-range */
 int parse_line_range_desc(const char *cmd, struct line_range *lr);
tools/perf/util/probe-file.c +36 -10

89 lines not on this page · raw message

tools/perf/util/probe-file.h +5 -0
index ce98162..0faf083 100644
@@ -21,6 +21,8 @@ struct probe_cache {
 
 #define PF_FL_UPROBE	1
 #define PF_FL_RW	2
+#define for_each_probe_cache_entry(entry, pcache) \
+	list_for_each_entry(entry, &pcache->list, list)
 
 /* probe-file.c depends on libelf */
 #ifdef HAVE_LIBELF_SUPPORT
@@ -34,6 +36,9 @@ 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,
#20 lore raw

PATCH v8 15/16 perf probe: Support @BUILDID or @FILE suffix for SDT events

In reply to Masami Hiramatsu

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
----

---
 tools/perf/util/build-id.c    |   40 ++++++++++++++++++++++++++++++++++++++++
 tools/perf/util/build-id.h    |    1 +
 tools/perf/util/probe-event.c |   16 ++++++++++++++--
 3 files changed, 55 insertions(+), 2 deletions(-)
tools/perf/util/build-id.c +40 -0
index 424f4e2..c32931c 100644
@@ -504,6 +504,46 @@ out:
 	return ret;
 }
 
+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 *list;
+	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) ||
+	    build_id_cache__list_all(&list, true) < 0)
+		return NULL;
+
+	strlist__for_each(nd, list) {
+		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(list);
+
+	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 480600b..9bd6d0b 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);
 int build_id_cache__list_all(struct strlist **result, 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 +14 -2
index 0019a22..bd31cac 100644
@@ -1253,8 +1253,20 @@ 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 contain only an SDT event 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) {
#21 lore raw

PATCH v8 16/16 perf probe: Support a special SDT probe format

In reply to Masami Hiramatsu

Support a special SDT probe format which can omit the '%' prefix only if the SDT group name starts with "sdt_". So, for example both of "%sdt_libc:setjump" and "sdt_libc:setjump" are acceptable for perf probe --add.

---
 tools/perf/Documentation/perf-probe.txt |    4 +++-
 tools/perf/util/probe-event.c           |   12 ++++++++++--
 2 files changed, 13 insertions(+), 3 deletions(-)
tools/perf/Documentation/perf-probe.txt +3 -1
index 43523be..2ebde8b 100644
@@ -152,7 +152,9 @@ Probe points are defined by following syntax.
      [[GROUP:]EVENT=]SRC;PTN [ARG ...]
 
     4) Pre-defined SDT events
-     %[PROVIDER:]SDTEVENT
+     %[sdt_PROVIDER:]SDTEVENT
+     or,
+     sdt_PROVIDER:SDTEVENT
 
 'EVENT' specifies the name of new event, if omitted, it will be set the name of the probed function. You can also specify a group name by 'GROUP', if omitted, set 'probe' is used for kprobe and 'probe_<bin>' is used for uprobe.
 Note that using existing group name can conflict with other events. Especially, using the group name reserved for kernel modules can hide embedded events in the
tools/perf/util/probe-event.c +10 -2
index bd31cac..a4819f9 100644
@@ -1245,9 +1245,17 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
 	if (!arg)
 		return -EINVAL;
 
-	if (arg[0] == '%') {
+	/*
+	 * If the probe point starts with '%',
+	 * or starts with "sdt_" and has a ':' but no '=',
+	 * then it should be a SDT/cached probe point.
+	 */
+	if (arg[0] == '%' ||
+	    (!strncmp(arg, "sdt_", 4) &&
+	     !!strchr(arg, ':') && !strchr(arg, '='))) {
 		pev->sdt = true;
-		arg++;
+		if (arg[0] == '%')
+			arg++;
 	}
 
 	ptr = strpbrk(arg, ";=@+%");
#22 lore raw
In reply to Masami Hiramatsu
Quoted 7 lines · Masami Hiramatsu

Hi,

Here is the 8th version of the patchset for probe-cache and initial SDT support.

The previous version is here; https://lkml.org/lkml/2016/5/11/446

Quoted 7 lines

This version I droped the second patch in v7 because it may involves unintended behavior change and we'd better discuss it out of this series. I also added comments why we can't use access(R_OK) for /proc/kcore.

Hemant, could you review and test this series so that we can proceed to your patch depending on this?

So, apart from the two issues which I mentioned in the individual patches, it seems fine.

However, I think we will need a bit detailed documentation for the probe cache feature as well as for the SDT support, given that we have different commands to add {probe,sdt} events for a binary and use them. I will write that that doc up based on your next version.

Quoted 49 lines

Thank you,

---

Hemant Kumar (1):
perf/sdt: ELF support for SDT

Masami Hiramatsu (15):
perf buildid: Introduce DSO__NAME_KALLSYMS and DSO__NAME_KCORE perf symbol: Cleanup the code flow of dso__find_kallsyms
perf-buildid-cache: Use path/to/bin/buildid/elf instead of path/to/bin/buildid perf probe: Add --cache option to cache the probe definitions perf probe: Use cache entry if possible
perf probe: Show all cached probes
perf probe: Remove caches when --cache is given
perf probe: Add group name support
perf buildid-cache: Scan and import user SDT events to probe cache perf probe: Accept %sdt and %cached event name
perf-list: Show SDT and pre-cached events
perf-list: Skip SDTs placed in invalid binaries
perf probe: Allow wildcard for cached events
perf probe: Support @BUILDID or @FILE suffix for SDT events
perf probe: Support a special SDT probe format

  tools/perf/Documentation/perf-probe.txt |   26 +-
  tools/perf/builtin-buildid-cache.c      |    8
  tools/perf/builtin-list.c               |    4
  tools/perf/builtin-probe.c              |   30 ++
  tools/perf/util/annotate.c              |    2
  tools/perf/util/build-id.c              |  295 ++++++++++++++++--
  tools/perf/util/build-id.h              |    8
  tools/perf/util/dso.h                   |    5
  tools/perf/util/machine.c               |    2
  tools/perf/util/parse-events.c          |   83 +++++
  tools/perf/util/parse-events.h          |    2
  tools/perf/util/probe-event.c           |  492 +++++++++++++++++++++++++++---
  tools/perf/util/probe-event.h           |    7
  tools/perf/util/probe-file.c            |  502 +++++++++++++++++++++++++++++++
  tools/perf/util/probe-file.h            |   41 +++
  tools/perf/util/symbol-elf.c            |  252 ++++++++++++++++
  tools/perf/util/symbol.c                |   73 ++---
  tools/perf/util/symbol.h                |   25 ++
  18 files changed, 1719 insertions(+), 138 deletions(-)

--
Masami Hiramatsu

Signature · 2 lines
Thanks,
Hemant Kumar
#23 lore raw
Quoted 15 lines · On Fri, 20 May 2016 10:21:09 +0530 Hemant Kumar <[email protected]>…
Quoted 12 lines · Masami Hiramatsu

Hi,

Here is the 8th version of the patchset for probe-cache and initial SDT support.

The previous version is here; https://lkml.org/lkml/2016/5/11/446

This version I droped the second patch in v7 because it may involves unintended behavior change and we'd better discuss it out of this series. I also added comments why we can't use access(R_OK) for /proc/kcore.

Quoted 5 lines
Quoted 2 lines

Hemant, could you review and test this series so that we can proceed to your patch depending on this?

So, apart from the two issues which I mentioned in the individual patches, it seems fine.

Thanks! I'll fix those issues and send v9.

Quoted 5 lines

However, I think we will need a bit detailed documentation for the probe cache feature as well as for the SDT support, given that we have different commands to add {probe,sdt} events for a binary and use them. I will write that that doc up based on your next version.

Would you mean updating Documentation/perf-probe.txt? Anyway it is welcome your contribution!

Thank you,

Quoted 55 lines
Quoted 50 lines

Thank you,

---

Hemant Kumar (1):
perf/sdt: ELF support for SDT

Masami Hiramatsu (15):
perf buildid: Introduce DSO__NAME_KALLSYMS and DSO__NAME_KCORE perf symbol: Cleanup the code flow of dso__find_kallsyms
perf-buildid-cache: Use path/to/bin/buildid/elf instead of path/to/bin/buildid perf probe: Add --cache option to cache the probe definitions perf probe: Use cache entry if possible
perf probe: Show all cached probes
perf probe: Remove caches when --cache is given
perf probe: Add group name support
perf buildid-cache: Scan and import user SDT events to probe cache perf probe: Accept %sdt and %cached event name
perf-list: Show SDT and pre-cached events
perf-list: Skip SDTs placed in invalid binaries
perf probe: Allow wildcard for cached events
perf probe: Support @BUILDID or @FILE suffix for SDT events
perf probe: Support a special SDT probe format

  tools/perf/Documentation/perf-probe.txt |   26 +-
  tools/perf/builtin-buildid-cache.c      |    8
  tools/perf/builtin-list.c               |    4
  tools/perf/builtin-probe.c              |   30 ++
  tools/perf/util/annotate.c              |    2
  tools/perf/util/build-id.c              |  295 ++++++++++++++++--
  tools/perf/util/build-id.h              |    8
  tools/perf/util/dso.h                   |    5
  tools/perf/util/machine.c               |    2
  tools/perf/util/parse-events.c          |   83 +++++
  tools/perf/util/parse-events.h          |    2
  tools/perf/util/probe-event.c           |  492 +++++++++++++++++++++++++++---
  tools/perf/util/probe-event.h           |    7
  tools/perf/util/probe-file.c            |  502 +++++++++++++++++++++++++++++++
  tools/perf/util/probe-file.h            |   41 +++
  tools/perf/util/symbol-elf.c            |  252 ++++++++++++++++
  tools/perf/util/symbol.c                |   73 ++---
  tools/perf/util/symbol.h                |   25 ++
  18 files changed, 1719 insertions(+), 138 deletions(-)

--
Masami Hiramatsu

Signature · 2 lines
Thanks,
Hemant Kumar
Signature · 1 line
Masami Hiramatsu <[email protected]>