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From: Ian Rogers <irogers@google.com>
Date: Fri, 10 May 2024 12:30:19 -0700
Message-ID: <CAP-5=fX1URY_v+66ifMHqQBWTywitCB5ekVh7pB9xbuxPjWrWA@mail.gmail.com>
Subject: Re: [PATCH v4 0/3] perf/core: Check sample_type in sample data saving
 helper functions
To: Yabin Cui <yabinc@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@redhat.com>, 
	Arnaldo Carvalho de Melo <acme@kernel.org>, Namhyung Kim <namhyung@kernel.org>, 
	Mark Rutland <mark.rutland@arm.com>, 
	Alexander Shishkin <alexander.shishkin@linux.intel.com>, Jiri Olsa <jolsa@kernel.org>, 
	Adrian Hunter <adrian.hunter@intel.com>, linux-perf-users@vger.kernel.org, 
	linux-kernel@vger.kernel.org, bpf@vger.kernel.org
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On Fri, May 10, 2024 at 12:14=E2=80=AFPM Yabin Cui <yabinc@google.com> wrot=
e:
>
> Hello,
>
> We use helper functions to save raw data, callchain and branch stack in
> perf_sample_data. These functions update perf_sample_data->dyn_size witho=
ut
> checking event->attr.sample_type, which may result in unused space alloca=
ted in
> sample records. To prevent this from happening, this patchset enforces ch=
ecking
> sample_type of an event in these helper functions.
>
> Thanks,
> Yabin
>
>
> Changes since v1:
>  - Check event->attr.sample_type & PERF_SAMPLE_RAW before
>    calling perf_sample_save_raw_data().
>  - Subject has been changed to reflect the change of solution.
>
> Changes since v2:
>  - Move sample_type check into perf_sample_save_raw_data().
>  - (New patch) Move sample_type check into perf_sample_save_callchain().
>  - (New patch) Move sample_type check into perf_sample_save_brstack().
>
> Changes since v3:
>  - Fix -Werror=3Dimplicit-function-declaration by moving has_branch_stack=
().
>
> Original commit message from v1:
>   perf/core: Trim dyn_size if raw data is absent
>
> Original commit message from v2/v3:
>   perf/core: Save raw sample data conditionally based on sample type
>
> Yabin Cui (3):
>   perf/core: Save raw sample data conditionally based on sample type
>   perf/core: Check sample_type in perf_sample_save_callchain
>   perf/core: Check sample_type in perf_sample_save_brstack

Reviewed-by: Ian Rogers <irogers@google.com>

Thanks,
Ian

>  arch/s390/kernel/perf_cpum_cf.c    |  2 +-
>  arch/s390/kernel/perf_pai_crypto.c |  2 +-
>  arch/s390/kernel/perf_pai_ext.c    |  2 +-
>  arch/x86/events/amd/core.c         |  3 +--
>  arch/x86/events/amd/ibs.c          |  5 ++---
>  arch/x86/events/core.c             |  3 +--
>  arch/x86/events/intel/ds.c         |  9 +++-----
>  include/linux/perf_event.h         | 20 ++++++++++++-----
>  kernel/events/core.c               | 35 +++++++++++++++---------------
>  kernel/trace/bpf_trace.c           | 11 +++++-----
>  10 files changed, 49 insertions(+), 43 deletions(-)
>
> --
> 2.45.0.118.g7fe29c98d7-goog
>