From 43c227f9dd7945bb4a895f841ecdb957bd8a12da Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 3 Mar 2017 15:50:33 +0000 Subject: disas/arm: Avoid unintended sign extension When assembling 'given' from the instruction bytes, C's integer promotion rules mean we may promote an unsigned char to a signed integer before shifting it, and then sign extend to a 64-bit long, which can set the high bits of the long. The code doesn't in fact care about the high bits if the long is 64 bits, but this is surprising, so don't do it. (Spotted by Coverity, CID 1005404.) Signed-off-by: Peter Maydell Message-id: 1488556233-31246-7-git-send-email-peter.maydell@linaro.org --- disas/arm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'disas') diff --git a/disas/arm.c b/disas/arm.c index 93c650344c..27396dd3e1 100644 --- a/disas/arm.c +++ b/disas/arm.c @@ -3901,9 +3901,9 @@ print_insn_arm (bfd_vma pc, struct disassemble_info *info) status = info->read_memory_func (pc, (bfd_byte *)b, 4, info); if (little) - given = (b[0]) | (b[1] << 8) | (b[2] << 16) | (b[3] << 24); + given = (b[0]) | (b[1] << 8) | (b[2] << 16) | ((unsigned)b[3] << 24); else - given = (b[3]) | (b[2] << 8) | (b[1] << 16) | (b[0] << 24); + given = (b[3]) | (b[2] << 8) | (b[1] << 16) | ((unsigned)b[0] << 24); } else { -- cgit v1.2.3