Re: [PATCH] perf daemon: Fix compile error with Asan

[Jiri Olsa]

On Wed, Feb 24, 2021 at 04:14:38PM +0900, Namhyung Kim wrote:
> 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>

Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>

thanks,
jirka

> ---
>  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
>