[PATCH] objtool: fix bytes check of lea's rex_prefix

From: Jiri Slaby
Date: Mon Dec 05 2016 - 05:56:07 EST


For the "lea %(rsp), %rbp" case, we check if there is a rex_prefix. But
we check "bytes" which is insn_byte_t[4] in rex_prefix (insn_field
structure). Therefore, the check is always true.

Instead, check nbytes which is the right one.

Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
tools/objtool/arch/x86/decode.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index b63a31be1218..5e0dea2cdc01 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -99,7 +99,7 @@ int arch_decode_instruction(struct elf *elf, struct section *sec,
break;

case 0x8d:
- if (insn.rex_prefix.bytes &&
+ if (insn.rex_prefix.nbytes &&
insn.rex_prefix.bytes[0] == 0x48 &&
insn.modrm.nbytes && insn.modrm.bytes[0] == 0x2c &&
insn.sib.nbytes && insn.sib.bytes[0] == 0x24)
--
2.11.0