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

[Ian Rogers]

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.

Thanks,
Ian

> Thanks,
> Namhyung