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Date: Wed, 15 May 2024 12:36:06 -0700
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Message-ID: <20240515193610.2350456-1-yabinc@google.com>
Subject: [PATCH v5 0/3] perf/core: Check sample_type in sample data saving
 helper functions
From: Yabin Cui <yabinc@google.com>
To: 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>, 
	Ian Rogers <irogers@google.com>, Adrian Hunter <adrian.hunter@intel.com>
Cc: linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, 
	bpf@vger.kernel.org, Yabin Cui <yabinc@google.com>
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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 without
checking event->attr.sample_type, which may result in unused space
allocated in sample records. To prevent this from happening, this patchset
enforces checking 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=implicit-function-declaration by moving has_branch_stack().

Changes since v4:
 - Give a warning if data->sample_flags is already set when calling the
   helper functions.

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

 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         | 26 +++++++++++++++++-----
 kernel/events/core.c               | 35 +++++++++++++++---------------
 kernel/trace/bpf_trace.c           | 11 +++++-----
 10 files changed, 55 insertions(+), 43 deletions(-)

-- 
2.45.0.rc1.225.g2a3ae87e7f-goog