Re: [PATCH v5 0/3] perf/core: Check sample_type in sample data saving helper functions

[Yabin Cui]

On Wed, May 22, 2024 at 9:27 AM Namhyung Kim <namhyung@xxxxxxxxxx> wrote:
>
> Hello,
>
> On Wed, May 15, 2024 at 12:36 PM Yabin Cui <yabinc@xxxxxxxxxx> wrote:
> >
> > 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
>
> Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>
>
> Thanks,
> Namhyung
>

Hi performance events subsystem maintainers,

The v5 patches were modified based on Peter's comments on the v4
patches. I'd be grateful if you could take a look when you have a
moment.
Thank you for your time and consideration.

Thanks,
Yabin

> >
> >  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
> >