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Subject[tip:perf/urgent] perf symbols: Load map before using map->map_ip ()
Commit-ID:  4afc81cd1caa93daa50c1c29a3ab747c978abc13
Gitweb: http://git.kernel.org/tip/4afc81cd1caa93daa50c1c29a3ab747c978abc13
Author: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
AuthorDate: Thu, 23 Jan 2014 02:29:50 +0000
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Thu, 23 Jan 2014 15:48:12 -0300

perf symbols: Load map before using map->map_ip()

In map_groups__find_symbol() map->map_ip is used without ensuring the
map is loaded. Then the address passed to map->map_ip isn't mapped at
the first time.

E.g. below code always fails to get a symbol at the first call;

addr = /* Somewhere in the kernel text */
symbol_conf.try_vmlinux_path = true;
symbol__init();
host_machine = machine__new_host();
sym = machine__find_kernel_function(host_machine,
addr, NULL, NULL);
/* Note that machine__find_kernel_function calls
map_groups__find_symbol */

This ensures it by calling map__load before using it in
map_groups__find_symbol().

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: "David A. Long" <dave.long@linaro.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20140123022950.7206.17357.stgit@kbuild-fedora.yrl.intra.hitachi.co.jp
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/map.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index ee1dd68..3b97513 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -386,7 +386,8 @@ struct symbol *map_groups__find_symbol(struct map_groups *mg,
{
struct map *map = map_groups__find(mg, type, addr);

- if (map != NULL) {
+ /* Ensure map is loaded before using map->map_ip */
+ if (map != NULL && map__load(map, filter) >= 0) {
if (mapp != NULL)
*mapp = map;
return map__find_symbol(map, map->map_ip(map, addr), filter);

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