Re: [PATCH] perf: fix a segfault problem.

[Namhyung Kim <namhyung@kernel.org>]

On Fri, Mar 13, 2015 at 08:41:32AM +0000, Wang Nan wrote:
> Without this patch, perf report cause segfault if pass "" as '-t':
> 
>   $ perf report -t ""
> 
>     # To display the perf.data header info, please use --header/--header-only options.
>     #
>     # Samples: 37  of event 'syscalls:sys_enter_write'
>     # Event count (approx.): 37
>     #
>     # Children    SelfCommand   Shared Object         Symbol
>     Segmentation fault
> 
> This patch avoid the segfault by checking empty string for
> 'symbol_conf.field_sep'.

What about resetting it to NULL if empty string was given?

Thanks,
Namhyung


> 
> Signed-off-by: Wang Nan <wangnan0@huawei.com>
> ---
>  tools/perf/util/sort.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c
> index 4593f36..7f563a0 100644
> --- a/tools/perf/util/sort.c
> +++ b/tools/perf/util/sort.c
> @@ -31,7 +31,8 @@ static int repsep_snprintf(char *bf, size_t size, const char *fmt, ...)
>  
>  	va_start(ap, fmt);
>  	n = vsnprintf(bf, size, fmt, ap);
> -	if (symbol_conf.field_sep && n > 0) {
> +	if (symbol_conf.field_sep && n > 0 &&
> +			(symbol_conf.field_sep[0] != '\0')) {
>  		char *sep = bf;
>  
>  		while (1) {
> -- 
> 1.8.3.4
>