Re: [PATCH] perf tools: Fix segfault due to invalid kernel dso access

[Namhyung Kim <namhyung@kernel.org>]

Arnaldo,

Could you please consider applying this?

Thanks,
Namhyung


On Tue, 18 Nov 2014 13:30:28 +0900, Namhyung Kim wrote:
> Jiri reported that the commit 96d78059d6d9 ("perf tools: Make vmlinux
> short name more like kallsyms short name") segfaults on perf script.
>
> When processing kernel mmap event, it should access the 'kernel'
> variable as sometimes it cannot find a matching dso from build-id
> table so 'dso' might be invalid.
>
> Reported-by: Jiri Olsa <jolsa@redhat.com>
> Tested-by: Jiri Olsa <jolsa@redhat.com>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
>  tools/perf/util/machine.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
> index 52e94902afb1..85033d80fd6a 100644
> --- a/tools/perf/util/machine.c
> +++ b/tools/perf/util/machine.c
> @@ -1106,8 +1106,8 @@ static int machine__process_kernel_mmap_event(struct machine *machine,
>  		if (__machine__create_kernel_maps(machine, kernel) < 0)
>  			goto out_problem;
>  
> -		if (strstr(dso->long_name, "vmlinux"))
> -			dso__set_short_name(dso, "[kernel.vmlinux]", false);
> +		if (strstr(kernel->long_name, "vmlinux"))
> +			dso__set_short_name(kernel, "[kernel.vmlinux]", false);
>  
>  		machine__set_kernel_mmap_len(machine, event);