Messages in this thread Patch in this message | | | From | Adrian Hunter <> | Subject | [PATCH 2/3] perf symbols: Fix unaligned access in get_x86_64_plt_disp() | Date | Thu, 16 Mar 2023 21:41:55 +0200 |
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Use memcpy() to avoid unaligned access.
Discovered using EXTRA_CFLAGS="-fsanitize=undefined -fsanitize=address".
Reported-by: kernel test robot <yujie.liu@intel.com> Link: https://lore.kernel.org/oe-lkp/202303061424.6ad43294-yujie.liu@intel.com Fixes: ce4c8e7966f3 ("perf symbols: Get symbols for .plt.got for x86-64") Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> --- tools/perf/util/symbol-elf.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c index 7ef5f6d7d415..ae810d4cf3cd 100644 --- a/tools/perf/util/symbol-elf.c +++ b/tools/perf/util/symbol-elf.c @@ -542,9 +542,12 @@ 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; } -- 2.34.1
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