Re: [PATCH v1] perf intel-pt: pkt-decoder: Fix alignment issues

[Namhyung Kim]

On Thu, Oct 12, 2023 at 5:27 AM Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:
>
> On 11/10/23 09:50, Ian Rogers wrote:
> > On Tue, Oct 10, 2023 at 10:56 PM Namhyung Kim <namhyung@xxxxxxxxxx> wrote:
> >>
> >> On Mon, Oct 9, 2023 at 8:31 AM Ian Rogers <irogers@xxxxxxxxxx> wrote:
> >>>
> >>> On Sun, Oct 8, 2023 at 10:29 PM Namhyung Kim <namhyung@xxxxxxxxxx> wrote:
> >>>>
> >>>> On Thu, Oct 5, 2023 at 2:24 PM Ian Rogers <irogers@xxxxxxxxxx> wrote:
> >>>>>
> >>>>> On Thu, Oct 5, 2023 at 12:06 PM Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:
> >>>>>>
> >>>>>> On 5/10/23 18:48, Ian Rogers wrote:
> >>>>>>> On Mon, Oct 2, 2023 at 3:19 PM Ian Rogers <irogers@xxxxxxxxxx> wrote:
> >>>>>>>>
> >>>>>>>> The byte aligned buffer is cast to large types and dereferenced
> >>>>>>>> causing misaligned pointer warnings from undefined behavior sanitizer.
> >>>>>>>> Fix the alignment issues with memcpy which may require the
> >>>>>>>> introduction of temporaries.
> >>>>>>>>
> >>>>>>>> Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> >>>>>>>> ---
> >>>>>>>
> >>>>>>> This is a relatively small change that fixes building with
> >>>>>>> -fsanitize=alignment -fsanitize-undefined-trap-on-error. Adrian, as
> >>>>>>> this is Intel-PT could you take a look?
> >>>>>>
> >>>>>> Thanks! This has been down my list of things to do for ages,
> >>>>>> but using get_unaligned_le16() etc seems nicer.  I sent a patch
> >>>>>> set for that.
> >>>>>
> >>>>> Thanks Adrian! Your patch set looks good and I think after Arnaldo's
> >>>>> comment is addressed we should go with it.
> >>>>
> >>>> I think it can be done as a later step as long as the interface is the
> >>>> same.  Can I add your Ack's to the Adrian's patchset?
> >>>
> >>> I think addressing Arnaldo's comment:
> >>> https://lore.kernel.org/lkml/ZR8QnasisGEsaaDR@xxxxxxxxxx/
> >>> will need some changes to the patch series, and so I was waiting to
> >>> see the outcome of that.
> >>
> >> It seems it's done without further changes.  Can I get your Ack's now?
> >
> > With the unaligned.h patch on its own, I think patch 1 of 5 needs
> > dropping. For the rest I'm happy to acked-by.
>
> The new patch is on top of the others, so patch 1 is still needed.

I think I can squash it to the patch 1 if needed.

Thanks,
Namhyung