Re: [PATCH RESEND v2 1/2] perf cs-etm: Support unknown_thread in cs_etm_auxtrace

From: Arnaldo Carvalho de Melo
Date: Fri May 11 2018 - 09:48:07 EST


Em Thu, May 10, 2018 at 12:01:59PM +0800, Leo Yan escreveu:
> CoreSight doesn't allocate thread structure for unknown_thread in etm
> auxtrace, so unknown_thread is NULL pointer. If the perf data doesn't
> contain valid tid and then cs_etm__mem_access() uses unknown_thread
> instead as thread handler, this results in segmentation fault when
> thread__find_addr_map() accesses thread handler.
>
> This commit creates new thread data which is used by unknown_thread, so
> CoreSight tracing can roll back to use unknown_thread if perf data
> doesn't include valid thread info. This commit also releases thread
> data for initialization failure case and for normal auxtrace free flow.
>
> Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>
> Acked-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>

Thanks, applied to perf/urgent.

And please use a more descriptive, eye catching summary, something like:

perf cs-etm: Fix segfault when accessing NULL unknown_thread variable

:-)

- Arnaldo