[PATCH] perf daemon: Fix compile error with Asan

From: Namhyung Kim
Date: Wed Feb 24 2021 - 02:15:58 EST


I'm seeing a build failure when build with address sanitizer.
It seems we could write to the name[100] if the var is longer.

$ make EXTRA_CFLAGS=-fsanitize=address
...
CC builtin-daemon.o
In function ‘get_session_name’,
inlined from ‘session_config’ at builtin-daemon.c:164:6,
inlined from ‘server_config’ at builtin-daemon.c:223:10:
builtin-daemon.c:155:11: error: writing 1 byte into a region of size 0 [-Werror=stringop-overflow=]
155 | *session = 0;
| ~~~~~~~~~^~~
builtin-daemon.c: In function ‘server_config’:
builtin-daemon.c:162:7: note: at offset 100 to object ‘name’ with size 100 declared here
162 | char name[100];
| ^~~~

Fixes: c0666261ff38 ("perf daemon: Add config file support")
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/builtin-daemon.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/builtin-daemon.c b/tools/perf/builtin-daemon.c
index 617feaf020f6..8f9fc61691da 100644
--- a/tools/perf/builtin-daemon.c
+++ b/tools/perf/builtin-daemon.c
@@ -161,7 +161,7 @@ static int session_config(struct daemon *daemon, const char *var, const char *va
struct daemon_session *session;
char name[100];

- if (get_session_name(var, name, sizeof(name)))
+ if (get_session_name(var, name, sizeof(name) - 1))
return -EINVAL;

var = strchr(var, '.');
--
2.30.0.617.g56c4b15f3c-goog