Em Wed, Nov 29, 2017 at 07:43:46PM +0100, Jiri Olsa escreveu: > When we detect different endianity we swap event before > processing. It's tricky for samples because we have no > idea what's inside. We treat it as an array of u64s, > swap them and later on we swap back parts which are > different.
Thanks, applied to perf/core, now at: https://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git/commit/?h=perf/core&id=26ea2ece7802f8fdaaacf321dbfb22de3271ab82 - Arnaldo > We mangle this way also the tracepoint raw data, which > ends up in report showing wrong data: > > 1.95% comm=Q^B pid=29285 prio=16777216 target_cpu=000 > 1.67% comm=l^B pid=0 prio=16777216 target_cpu=000 > > Luckily the traceevent library handles the endianity by > itself (thank you Steven!), so we can pass the RAW data > directly in the other endianity. > > 2.51% comm=beah-rhts-task pid=1175 prio=120 target_cpu=002 > 2.23% comm=kworker/0:0 pid=11566 prio=120 target_cpu=000 > > The fix is basically to swap back the raw data if different > endianity is detected. > > Cc: David Ahern <[email protected]> > Cc: Steven Rostedt (VMware) <[email protected]> > Link: http://lkml.kernel.org/n/[email protected] > Signed-off-by: Jiri Olsa <[email protected]> > --- > tools/perf/util/evsel.c | 20 +++++++++++++++++--- > 1 file changed, 17 insertions(+), 3 deletions(-) > > diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c > index 95853c51c0ca..09c68cf2d9d2 100644 > --- a/tools/perf/util/evsel.c > +++ b/tools/perf/util/evsel.c > @@ -36,6 +36,7 @@ > #include "debug.h" > #include "trace-event.h" > #include "stat.h" > +#include "memswap.h" > #include "util/parse-branch-options.h" > > #include "sane_ctype.h" > @@ -2131,14 +2132,27 @@ int perf_evsel__parse_sample(struct perf_evsel > *evsel, union perf_event *event, > if (type & PERF_SAMPLE_RAW) { > OVERFLOW_CHECK_u64(array); > u.val64 = *array; > - if (WARN_ONCE(swapped, > - "Endianness of raw data not corrected!\n")) { > - /* undo swap of u64, then swap on individual u32s */ > + > + /* > + * Undo swap of u64, then swap on individual u32s, > + * get the size of the raw area and undo all of the > + * swap. The pevent interface handles endianity by > + * itself. > + */ > + if (swapped) { > u.val64 = bswap_64(u.val64); > u.val32[0] = bswap_32(u.val32[0]); > u.val32[1] = bswap_32(u.val32[1]); > } > data->raw_size = u.val32[0]; > + > + /* > + * The raw data is aligned on 64bits including the > + * u32 size, so it's safe to use mem_bswap_64. > + */ > + if (swapped) > + mem_bswap_64((void *) array, data->raw_size); > + > array = (void *)array + sizeof(u32); > > OVERFLOW_CHECK(array, data->raw_size, max_size); > -- > 2.13.6
