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

Arnaldo Carvalho de Melo
2020-11-26T17:30:55Z

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?

- 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