Re: [PATCH 06/25] perf tools: Do not swap mmap2 fields in case it contains build id

Jiri Olsa
2020-11-28T22:23:00Z

On Thu, Nov 26, 2020 at 02:30:42PM -0300, Arnaldo Carvalho de Melo wrote:
> Em Thu, Nov 26, 2020 at 06:00:07PM +0100, Jiri Olsa escreveu:
> > If PERF_RECORD_MISC_MMAP_BUILD_ID misc bit is set,
> > mmap2 event carries build id, placed in following union:
> >
> > union {
> > struct {
> > u32 maj;
> > u32 min;
> > u64 ino;
> > u64 ino_generation;
> > };
> > struct {
> > u8 build_id[20];
> > u8 build_id_size;
> > u8 __reserved_1;
> > u16 __reserved_2;
> > };
> > };
>
> Did you forgot to update just this cset comment?

ah yes, will fix

thanks,
jirka

>
> - Arnaldo
>
> > In this case we can't swap above fields.
> >
> > Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> > ---
> > tools/perf/util/session.c | 11 +++++++----
> > 1 file changed, 7 insertions(+), 4 deletions(-)
> >
> > diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
> > index 5cc722b6fe7c..cc1c11ca94fd 100644
> > --- a/tools/perf/util/session.c
> > +++ b/tools/perf/util/session.c
> > @@ -592,10 +592,13 @@ static void perf_event__mmap2_swap(union perf_event *event,
> > event->mmap2.start = bswap_64(event->mmap2.start);
> > event->mmap2.len = bswap_64(event->mmap2.len);
> > event->mmap2.pgoff = bswap_64(event->mmap2.pgoff);
> > - event->mmap2.maj = bswap_32(event->mmap2.maj);
> > - event->mmap2.min = bswap_32(event->mmap2.min);
> > - event->mmap2.ino = bswap_64(event->mmap2.ino);
> > - event->mmap2.ino_generation = bswap_64(event->mmap2.ino_generation);
> > +
> > + if (!(event->header.misc & PERF_RECORD_MISC_MMAP_BUILD_ID)) {
> > + event->mmap2.maj = bswap_32(event->mmap2.maj);
> > + event->mmap2.min = bswap_32(event->mmap2.min);
> > + event->mmap2.ino = bswap_64(event->mmap2.ino);
> > + event->mmap2.ino_generation = bswap_64(event->mmap2.ino_generation);
> > + }
> >
> > if (sample_id_all) {
> > void *data = &event->mmap2.filename;
> > --
> > 2.26.2
> >
>
> --
>
> - Arnaldo
>