From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752069AbdK2Snu (ORCPT ); Wed, 29 Nov 2017 13:43:50 -0500 Received: from mx1.redhat.com ([209.132.183.28]:53666 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751791AbdK2Snt (ORCPT ); Wed, 29 Nov 2017 13:43:49 -0500 From: Jiri Olsa To: Arnaldo Carvalho de Melo Cc: David Ahern , Steven Rostedt , lkml , Ingo Molnar , Namhyung Kim , Peter Zijlstra Subject: [PATCH] perf tools: Fix swap for samples with raw data Date: Wed, 29 Nov 2017 19:43:46 +0100 Message-Id: <20171129184346.3656-1-jolsa@kernel.org> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Wed, 29 Nov 2017 18:43:49 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. 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 Cc: Steven Rostedt (VMware) Link: http://lkml.kernel.org/n/tip-0zcnwqf2k4pq854huwxc1v4l@git.kernel.org Signed-off-by: Jiri Olsa --- 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