Re: [PATCH] perf tools: Avoid unaligned pointer operations
From: Namhyung Kim
Date: Thu Dec 12 2024 - 16:01:39 EST
On Thu, Dec 12, 2024 at 03:41:02PM -0300, Arnaldo Carvalho de Melo wrote:
> On Wed, Nov 27, 2024 at 04:51:15PM -0800, Ian Rogers wrote:
> > On Wed, Nov 27, 2024 at 1:26 PM Namhyung Kim <namhyung@xxxxxxxxxx> wrote:
> > > The sample data is 64-bit aligned basically but raw data starts with
> > > 32-bit length field and data follows. In perf_event__synthesize_sample
> > > it treats the sample data as a 64-bit array. And it needs some trick
> > > to update the raw data properly.
>
> > > But it seems some compilers are not happy with this and the program dies
> > > siliently. I found the sample parsing test failed without any messages
> > > on affected systems.
>
> > > Let's update the code to use a 32-bit pointer directly and make sure the
> > > result is 64-bit aligned again. No functional changes intended.
>
> > > Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
>
> > Reviewed-by: Ian Rogers <irogers@xxxxxxxxxx>
>
> Looks good, applied to perf-tools-next since this is something that is
> not new nor looks urgent.
>
> I think that since we have multiple maintainers, one for not urgent
> stuff/development and the other for the current window/urgent stuff,
> that we should express the expectation about where a patch should be
> processed, by having on the subject the tree the submitter thinks should
> take the patch, i.e. for this one:
>
> [PATCH next] perf tools: Avoid unaligned pointer operations
>
> While for urgent stuff we could do:
>
> [PATCH urgent] perf tools: Avoid unaligned pointer operations
>
> wdyt?
Looks good. It'd be really great if contributors can do this.
But I also think 'next' should be the default so only 'urgent' would be
specified if needed.
Thanks,
Namhyung