Re: [PATCH] perf: increase size of buf in perf_evsel__hists_browse()

[Jiri Olsa <jolsa@redhat.com>]

On Fri, Oct 30, 2020 at 04:54:31PM -0700, Song Liu wrote:
> Making perf with gcc-9.1.1 generates the following warning:
> 
>   CC       ui/browsers/hists.o
> ui/browsers/hists.c: In function 'perf_evsel__hists_browse':
> ui/browsers/hists.c:3078:61: error: '%d' directive output may be \
> truncated writing between 1 and 11 bytes into a region of size \
> between 2 and 12 [-Werror=format-truncation=]
> 
>  3078 |       "Max event group index to sort is %d (index from 0 to %d)",
>       |                                                             ^~
> ui/browsers/hists.c:3078:7: note: directive argument in the range [-2147483648, 8]
>  3078 |       "Max event group index to sort is %d (index from 0 to %d)",
>       |       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> In file included from /usr/include/stdio.h:937,
>                  from ui/browsers/hists.c:5:
> 
> IOW, the string in line 3078 might be too long for buf[] of 64 bytes.
> 
> Fix this by increasing the size of buf[] to 128.
> 
> Fixes: dbddf1747441  ("perf report/top TUI: Support hotkeys to let user select any event for sorting")
> Cc: stable <stable@vger.kernel.org> # v5.7+
> Cc: Jin Yao <yao.jin@linux.intel.com>
> Cc: Jiri Olsa <jolsa@kernel.org>
> Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
> Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
> Signed-off-by: Song Liu <songliubraving@fb.com>

Acked-by: Jiri Olsa <jolsa@kernel.org>

jirka

> ---
>  tools/perf/ui/browsers/hists.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
> index a07626f072087..b0e1880cf992b 100644
> --- a/tools/perf/ui/browsers/hists.c
> +++ b/tools/perf/ui/browsers/hists.c
> @@ -2963,7 +2963,7 @@ static int perf_evsel__hists_browse(struct evsel *evsel, int nr_events,
>  	struct popup_action actions[MAX_OPTIONS];
>  	int nr_options = 0;
>  	int key = -1;
> -	char buf[64];
> +	char buf[128];
>  	int delay_secs = hbt ? hbt->refresh : 0;
>  
>  #define HIST_BROWSER_HELP_COMMON					\
> -- 
> 2.24.1
>