Re: [PATCH] perf record: handle death by SIGTERM

[Namhyung Kim <namhyung@kernel.org>]

Hi David,

On Tue, 07 May 2013 14:56:17 -0600, David Ahern wrote:
> On 5/7/13 12:29 AM, Ingo Molnar wrote:
>>
>> * Stephane Eranian <eranian@google.com> wrote:
>>
>>> This is a good fix. I have run into this infinite loop in perf report
>>> many times.
>>
>> Hm, perf record should really not assume much about the perf.data and
>> should avoid infinite loops ...
>>
>> So while making perf.data more consistent on SIGTERM is a nice fix, perf
>> report should be fixed as well to detect loops and such.
>>
>> Thanks,
>>
>> 	Ingo
>>
>
> This seems to do the trick:

Acked-by: Namhyung Kim <namhyung@kernel.org>

Thanks,
Namhyung

>
> diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
> index 326068a..e82646f 100644
> --- a/tools/perf/util/header.c
> +++ b/tools/perf/util/header.c
> @@ -2802,6 +2802,17 @@ int perf_session__read_header(struct
> perf_session *session, int fd)
>     if (perf_file_header__read(&f_header, header, fd) < 0)
>         return -EINVAL;
>
> +   /*
> +    * sanity check that perf.data was written cleanly: data size
> +    * is initialized to 0 and updated only if the on_exit function
> +    * is run. If data size is still 0 then the file cannot be
> +    * processed.
> +    */
> +   if (f_header.data.size == 0) {
> +       pr_err("data size is 0. Was record properly terminated?\n");
> +       return -1;
> +   }
> +
>     nr_attrs = f_header.attrs.size / f_header.attr_size;
>     lseek(fd, f_header.attrs.offset, SEEK_SET);