This is a note to let you know that I've just added the patch titled
perf symbols: Fix unaligned access in get_x86_64_plt_disp()
to the 6.3-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
perf-symbols-fix-unaligned-access-in-get_x86_64_plt_.patch
and it can be found in the queue-6.3 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d842c5f1b6af4584ec2cdb813c7628d16e67703a
Author: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Date: Thu Mar 16 21:41:55 2023 +0200
perf symbols: Fix unaligned access in get_x86_64_plt_disp()
[ Upstream commit a2410b579c72242ac0f77b3768093d8c1b48012e ]
Use memcpy() to avoid unaligned access.
Discovered using EXTRA_CFLAGS="-fsanitize=undefined -fsanitize=address".
Fixes: ce4c8e7966f317ef ("perf symbols: Get symbols for .plt.got for x86-64")
Reported-by: kernel test robot <yujie.liu@xxxxxxxxx>
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Acked-by: Ian Rogers <irogers@xxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Link: https://lore.kernel.org/oe-lkp/202303061424.6ad43294-yujie.liu@xxxxxxxxx
Link: https://lore.kernel.org/r/20230316194156.8320-2-adrian.hunter@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 98a18fb854180..42b83bef67aaf 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -565,9 +565,12 @@ static u32 get_x86_64_plt_disp(const u8 *p)
n += 1;
/* jmp with 4-byte displacement */
if (p[n] == 0xff && p[n + 1] == 0x25) {
+ u32 disp;
+
n += 2;
/* Also add offset from start of entry to end of instruction */
- return n + 4 + le32toh(*(const u32 *)(p + n));
+ memcpy(&disp, p + n, sizeof(disp));
+ return n + 4 + le32toh(disp);
}
return 0;
}
