Re: [RFC PATCH 01/22] perf: probe: avoid segfault if passed with ''.

[Masami Hiramatsu]

On 2015/04/30 19:52, Wang Nan wrote:
> Since parse_perf_probe_point() deals with a user passed argument, we
> should not assume it to be a valid string.
> 
> Without this patch, if pass '' to perf probe, a segfault raises:
> 
>  $ perf probe -a ''
>  Segmentation fault
> 
> This patch checks argument of parse_perf_probe_point() before
> string processing.
> 
> After this patch:
> 
>  $ perf probe -a ''
> 
>   usage: perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]
>      or: perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]
>      ...

This looks OK to me.

Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>

Could you split this as an independent bugfix with my ack?

Thank you,

> 
> Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
> ---
>  tools/perf/util/probe-event.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
> index d8bb616..d05b77c 100644
> --- a/tools/perf/util/probe-event.c
> +++ b/tools/perf/util/probe-event.c
> @@ -1084,6 +1084,8 @@ static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
>  	 *
>  	 * TODO:Group name support
>  	 */
> +	if (!arg)
> +		return -EINVAL;
>  
>  	ptr = strpbrk(arg, ";=@+%");
>  	if (ptr && *ptr == '=') {	/* Event name */
> 


-- 
Masami HIRAMATSU
Linux Technology Research Center, System Productivity Research Dept.
Center for Technology Innovation - Systems Engineering
Hitachi, Ltd., Research & Development Group
E-mail: masami.hiramatsu.pt@xxxxxxxxxxx
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