[PATCH 2/2] perf annotate: Use build-ids to find the right DSO

From: Arnaldo Carvalho de Melo
Date: Thu May 20 2010 - 12:11:15 EST


From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>

We were still using the pathname found on the MMAP event, that could not
be the one we used when recording, so use the build-id cache for that,
only falling back to use the pathname in the MMAP event if no build-ids
are available.

With this we now also are able to do secure, seamless offline annotation.

Example:

[root@doppio linux-2.6-tip]# perf report -g none -v 2> /dev/null | head -10
8.12% Xorg /usr/lib64/libpixman-1.so.0.14.0 0x0000000000026d02 B [.] pixman_rasterize_edges
4.68% firefox /usr/lib64/xulrunner-1.9.1/libxul.so 0x00000000005dbdba B [.] 0x000000005dbdba
3.70% swapper /lib/modules/2.6.34-rc6/build/vmlinux 0xffffffff81022cea ! [k] read_hpet
2.96% init /lib/modules/2.6.34-rc6/build/vmlinux 0xffffffff81022cea ! [k] read_hpet
2.73% swapper /lib/modules/2.6.34-rc6/build/vmlinux 0xffffffff8100a738 ! [k] mwait_idle_with_hints
[root@doppio linux-2.6-tip]# perf annotate -v pixman_rasterize_edges 2>&1 | grep Executing
Executing: objdump --start-address=0x000000371ce26670 --stop-address=0x000000371ce2709f -dS /root/.debug/.build-id/bd/6ac5199137aaeb279f864717d8d061477466c1|grep -v /root/.debug/.build-id/bd/6ac5199137aaeb279f864717d8d061477466c1|expand
[root@doppio linux-2.6-tip]# perf buildid-list | grep libpixman-1.so.0.14.0
bd6ac5199137aaeb279f864717d8d061477466c1 /usr/lib64/libpixman-1.so.0.14.0
[root@doppio linux-2.6-tip]#

Reported-by: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: FrÃdÃric Weisbecker <fweisbec@xxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: Tom Zanussi <tzanussi@xxxxxxxxx>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/util/build-id.c | 22 ++++++++++++++++++++++
tools/perf/util/build-id.h | 2 ++
tools/perf/util/callchain.c | 1 +
tools/perf/util/callchain.h | 1 -
tools/perf/util/hist.c | 34 ++++++++++++++++++++++++++--------
tools/perf/util/symbol.c | 12 +++---------
6 files changed, 54 insertions(+), 18 deletions(-)

diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index 0f60a39..70c5cf8 100644
--- a/tools/perf/util/build-id.c
+++ b/tools/perf/util/build-id.c
@@ -6,6 +6,8 @@
* Copyright (C) 2009, 2010 Red Hat Inc.
* Copyright (C) 2009, 2010 Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
*/
+#include "util.h"
+#include <stdio.h>
#include "build-id.h"
#include "event.h"
#include "symbol.h"
@@ -37,3 +39,23 @@ struct perf_event_ops build_id__mark_dso_hit_ops = {
.mmap = event__process_mmap,
.fork = event__process_task,
};
+
+char *dso__build_id_filename(struct dso *self, char *bf, size_t size)
+{
+ char build_id_hex[BUILD_ID_SIZE * 2 + 1];
+ const char *home;
+
+ if (!self->has_build_id)
+ return NULL;
+
+ build_id__sprintf(self->build_id, sizeof(self->build_id), build_id_hex);
+ home = getenv("HOME");
+ if (bf == NULL) {
+ if (asprintf(&bf, "%s/%s/.build-id/%.2s/%s", home,
+ DEBUG_CACHE_DIR, build_id_hex, build_id_hex + 2) < 0)
+ return NULL;
+ } else
+ snprintf(bf, size, "%s/%s/.build-id/%.2s/%s", home,
+ DEBUG_CACHE_DIR, build_id_hex, build_id_hex + 2);
+ return bf;
+}
diff --git a/tools/perf/util/build-id.h b/tools/perf/util/build-id.h
index 1d981d6..5dafb00 100644
--- a/tools/perf/util/build-id.h
+++ b/tools/perf/util/build-id.h
@@ -5,4 +5,6 @@

extern struct perf_event_ops build_id__mark_dso_hit_ops;

+char *dso__build_id_filename(struct dso *self, char *bf, size_t size);
+
#endif
diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
index 21a52e0..62b69ad 100644
--- a/tools/perf/util/callchain.c
+++ b/tools/perf/util/callchain.c
@@ -15,6 +15,7 @@
#include <errno.h>
#include <math.h>

+#include "util.h"
#include "callchain.h"

bool ip_callchain__valid(struct ip_callchain *chain, event_t *event)
diff --git a/tools/perf/util/callchain.h b/tools/perf/util/callchain.h
index 1cba1f5..1ca73e4 100644
--- a/tools/perf/util/callchain.h
+++ b/tools/perf/util/callchain.h
@@ -5,7 +5,6 @@
#include <linux/list.h>
#include <linux/rbtree.h>
#include "event.h"
-#include "util.h"
#include "symbol.h"

enum chain_mode {
diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index 9a71c94..739c39f 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -1,3 +1,4 @@
+#include "build-id.h"
#include "util.h"
#include "hist.h"
#include "session.h"
@@ -988,22 +989,35 @@ int hist_entry__annotate(struct hist_entry *self, struct list_head *head)
struct symbol *sym = self->ms.sym;
struct map *map = self->ms.map;
struct dso *dso = map->dso;
- const char *filename = dso->long_name;
+ char *filename = dso__build_id_filename(dso, NULL, 0);
char command[PATH_MAX * 2];
FILE *file;
+ int err = -1;
u64 len;

- if (!filename)
- return -1;
+ if (filename == NULL) {
+ if (dso->has_build_id) {
+ pr_err("Can't annotate %s: not enough memory\n",
+ sym->name);
+ return -1;
+ }
+ /*
+ * If we don't have build-ids, well, lets hope that this
+ * DSO is the same as when 'perf record' ran.
+ */
+ filename = dso->long_name;
+ }

if (dso->origin == DSO__ORIG_KERNEL) {
- if (dso->annotate_warned)
- return 0;
+ if (dso->annotate_warned) {
+ err = 0;
+ goto out_free_filename;
+ }
dso->annotate_warned = 1;
pr_err("Can't annotate %s: No vmlinux file was found in the "
"path:\n", sym->name);
vmlinux_path__fprintf(stderr);
- return -1;
+ goto out_free_filename;
}

pr_debug("%s: filename=%s, sym=%s, start=%#Lx, end=%#Lx\n", __func__,
@@ -1025,14 +1039,18 @@ int hist_entry__annotate(struct hist_entry *self, struct list_head *head)

file = popen(command, "r");
if (!file)
- return -1;
+ goto out_free_filename;

while (!feof(file))
if (hist_entry__parse_objdump_line(self, file, head) < 0)
break;

pclose(file);
- return 0;
+ err = 0;
+out_free_filename:
+ if (dso->has_build_id)
+ free(filename);
+ return err;
}

void hists__inc_nr_events(struct hists *self, u32 type)
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 96bff0e..aaa51ba 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -11,6 +11,7 @@
#include <sys/param.h>
#include <fcntl.h>
#include <unistd.h>
+#include "build-id.h"
#include "symbol.h"
#include "strlist.h"

@@ -1293,7 +1294,6 @@ int dso__load(struct dso *self, struct map *map, symbol_filter_t filter)
int size = PATH_MAX;
char *name;
u8 build_id[BUILD_ID_SIZE];
- char build_id_hex[BUILD_ID_SIZE * 2 + 1];
int ret = -1;
int fd;
struct machine *machine;
@@ -1325,15 +1325,8 @@ int dso__load(struct dso *self, struct map *map, symbol_filter_t filter)
}

self->origin = DSO__ORIG_BUILD_ID_CACHE;
-
- if (self->has_build_id) {
- build_id__sprintf(self->build_id, sizeof(self->build_id),
- build_id_hex);
- snprintf(name, size, "%s/%s/.build-id/%.2s/%s",
- getenv("HOME"), DEBUG_CACHE_DIR,
- build_id_hex, build_id_hex + 2);
+ if (dso__build_id_filename(self, name, size) != NULL)
goto open_file;
- }
more:
do {
self->origin++;
@@ -1349,6 +1342,7 @@ more:
case DSO__ORIG_BUILDID:
if (filename__read_build_id(self->long_name, build_id,
sizeof(build_id))) {
+ char build_id_hex[BUILD_ID_SIZE * 2 + 1];
build_id__sprintf(build_id, sizeof(build_id),
build_id_hex);
snprintf(name, size,
--
1.6.2.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/