From: Numfor Mbiziwo-Tiapo <nums@google.com>
To: peterz@infradead.org, mingo@redhat.com, acme@kernel.org,
alexander.shishkin@linux.intel.com, jolsa@redhat.com,
namhyung@kernel.org, songliubraving@fb.com, mbd@fb.com
Cc: linux-kernel@vger.kernel.org, irogers@google.com,
eranian@google.com, Numfor Mbiziwo-Tiapo <nums@google.com>
Subject: [PATCH 3/3] Fix insn.c misaligned address error
Date: Wed, 24 Jul 2019 11:45:12 -0700 [thread overview]
Message-ID: <20190724184512.162887-4-nums@google.com> (raw)
In-Reply-To: <20190724184512.162887-1-nums@google.com>
The ubsan (undefined behavior sanitizer) version of perf throws an
error on the 'x86 instruction decoder - new instructions' function
of perf test.
To reproduce this run:
make -C tools/perf USE_CLANG=1 EXTRA_CFLAGS="-fsanitize=undefined"
then run: tools/perf/perf test 62 -v
The error occurs in the __get_next macro (line 34) where an int is
read from a potentially unaligned address. Using memcpy instead of
assignment from an unaligned pointer.
Signed-off-by: Numfor Mbiziwo-Tiapo <nums@google.com>
---
tools/perf/util/intel-pt-decoder/insn.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/intel-pt-decoder/insn.c b/tools/perf/util/intel-pt-decoder/insn.c
index ca983e2bea8b..de1944c60aa9 100644
--- a/tools/perf/util/intel-pt-decoder/insn.c
+++ b/tools/perf/util/intel-pt-decoder/insn.c
@@ -31,7 +31,8 @@
((insn)->next_byte + sizeof(t) + n <= (insn)->end_kaddr)
#define __get_next(t, insn) \
- ({ t r = *(t*)insn->next_byte; insn->next_byte += sizeof(t); r; })
+ ({ t r; memcpy(&r, insn->next_byte, sizeof(t)); \
+ insn->next_byte += sizeof(t); r; })
#define __peek_nbyte_next(t, insn, n) \
({ t r = *(t*)((insn)->next_byte + n); r; })
--
2.22.0.657.g960e92d24f-goog
next prev parent reply other threads:[~2019-07-24 18:45 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-24 18:45 [PATCH 0/3] Perf UBsan Patches Numfor Mbiziwo-Tiapo
2019-07-24 18:45 ` [PATCH 1/3] Fix backward-ring-buffer.c format-truncation error Numfor Mbiziwo-Tiapo
2019-07-25 13:08 ` David Laight
2019-07-26 19:40 ` Arnaldo Carvalho de Melo
2019-07-29 20:57 ` [PATCH v2] Fix annotate.c use of uninitialized value error Numfor Mbiziwo-Tiapo
2019-08-07 11:32 ` Jiri Olsa
2019-10-25 22:11 ` Ian Rogers
2020-07-09 0:54 ` Ian Rogers
2020-07-09 15:38 ` Arnaldo Carvalho de Melo
2019-07-24 18:45 ` [PATCH 2/3] Fix ordered-events.c array-bounds error Numfor Mbiziwo-Tiapo
2019-07-26 19:33 ` Arnaldo Carvalho de Melo
2019-07-26 19:35 ` Arnaldo Carvalho de Melo
2019-07-24 18:45 ` Numfor Mbiziwo-Tiapo [this message]
2019-07-25 13:06 ` [PATCH 3/3] Fix insn.c misaligned address error David Laight
2019-07-25 21:18 ` Ian Rogers
2019-07-26 19:38 ` Arnaldo Carvalho de Melo
2019-07-27 9:46 ` Masami Hiramatsu
2019-07-29 8:22 ` Adrian Hunter
2019-07-29 19:32 ` Ian Rogers
2019-07-30 7:50 ` Adrian Hunter
2019-07-30 0:47 ` Masami Hiramatsu
2019-07-30 7:53 ` Adrian Hunter
2019-07-30 9:17 ` David Laight
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