[tip:perf/urgent] perf callchain: Compare dsos (as well) for CCKEY_FUNCTION

[tip-bot for Ravi Bangoria]

Commit-ID:  c1fbc0cf81f1c464f5fda322c1104d4bb1da6711
Gitweb:     https://git.kernel.org/tip/c1fbc0cf81f1c464f5fda322c1104d4bb1da6711
Author:     Ravi Bangoria <ravi.bangoria@xxxxxxxxxxxxxxxxxx>
AuthorDate: Thu, 5 Oct 2017 14:42:34 +0530
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Thu, 5 Oct 2017 10:52:54 -0300

perf callchain: Compare dsos (as well) for CCKEY_FUNCTION

Two functions from different binaries can have same start address. Thus,
comparing only start address in match_chain() leads to inconsistent
callchains. Fix this by adding a check for dsos as well.

Ex, https://www.spinics.net/lists/linux-perf-users/msg04067.html

Reported-by: Alexander Pozdneev <pozdneyev@xxxxxxxxx>
Signed-off-by: Ravi Bangoria <ravi.bangoria@xxxxxxxxxxxxxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Krister Johansen <kjlx@xxxxxxxxxxxxxxxxxx>
Cc: Milian Wolff <milian.wolff@xxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Yao Jin <yao.jin@xxxxxxxxxxxxxxx>
Cc: zhangmengting@xxxxxxxxxx
Link: http://lkml.kernel.org/r/20171005091234.5874-1-ravi.bangoria@xxxxxxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/util/callchain.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
index be09d77..a971caf 100644
--- a/tools/perf/util/callchain.c
+++ b/tools/perf/util/callchain.c
@@ -685,6 +685,8 @@ static enum match_result match_chain(struct callchain_cursor_node *node,
 {
 	struct symbol *sym = node->sym;
 	u64 left, right;
+	struct dso *left_dso = NULL;
+	struct dso *right_dso = NULL;
 
 	if (callchain_param.key == CCKEY_SRCLINE) {
 		enum match_result match = match_chain_srcline(node, cnode);
@@ -696,12 +698,14 @@ static enum match_result match_chain(struct callchain_cursor_node *node,
 	if (cnode->ms.sym && sym && callchain_param.key == CCKEY_FUNCTION) {
 		left = cnode->ms.sym->start;
 		right = sym->start;
+		left_dso = cnode->ms.map->dso;
+		right_dso = node->map->dso;
 	} else {
 		left = cnode->ip;
 		right = node->ip;
 	}
 
-	if (left == right) {
+	if (left == right && left_dso == right_dso) {
 		if (node->branch) {
 			cnode->branch_count++;