[tip:perf/core] perf tools: Don' t try to lookup objdump for live mode

[tip-bot for Namhyung Kim <namhyung.kim@lge.com>]

Commit-ID:  ff6f7778a66edc033044a6baa2459ce79519e571
Gitweb:     http://git.kernel.org/tip/ff6f7778a66edc033044a6baa2459ce79519e571
Author:     Namhyung Kim <namhyung.kim@lge.com>
AuthorDate: Wed, 7 Nov 2012 10:30:15 +0900
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Thu, 8 Nov 2012 17:26:52 -0300

perf tools: Don't try to lookup objdump for live mode

Arnaldo reported that annotation during perf top resulted in a segfault.
It was because the env->arch was NULL and we don't set it for a live
session.  In fact, no need to look up objdump in this case since we can
use system's default (native) objdump.

Reported-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Irina Tirdea <irina.tirdea@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1352251815-12615-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/arch/common.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/tools/perf/arch/common.c b/tools/perf/arch/common.c
index 5683529..3e975cb 100644
--- a/tools/perf/arch/common.c
+++ b/tools/perf/arch/common.c
@@ -199,6 +199,13 @@ out_error:
 
 int perf_session_env__lookup_objdump(struct perf_session_env *env)
 {
+	/*
+	 * For live mode, env->arch will be NULL and we can use
+	 * the native objdump tool.
+	 */
+	if (env->arch == NULL)
+		return 0;
+
 	return perf_session_env__lookup_binutils_path(env, "objdump",
 						      &objdump_path);
 }