Re: [PATCH 2/2] perf tools: Fix record sample overlap check for callchains

[David Ahern <dsahern@gmail.com>]

On 3/30/12 11:38 AM, Andi Kleen wrote:
> From: Andi Kleen<ak@linux.intel.com>
>
> perf record checks for buffer overflow, but checked for the wrong
> size for callchains.  callchains are 8 bytes each, not 1.
>
> Signed-off-by: Andi Kleen<ak@linux.intel.com>
> ---
>   tools/perf/util/evsel.c |    2 +-
>   1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index f421f7c..90c0756 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -550,7 +550,7 @@ int perf_event__parse_sample(const union perf_event *event, u64 type,
>
>   		data->callchain = (struct ip_callchain *)array;
>
> -		if (sample_overlap(event, array, data->callchain->nr))
> +		if (sample_overlap(event, array, (1 + data->callchain->nr) * 8))

sizeof(u64) rather than the magic 8?

David

>   			return -EFAULT;
>
>   		array += 1 + data->callchain->nr;