[PATCH 4.9 078/172] objtool: Fix IRETs opcode

Greg Kroah-Hartman
2017-07-03T13:34:18Z

From: Jiri Slaby <jslaby@suse.cz>

[ Upstream commit b5b46c4740aed1538544f0fa849c5b76c7823469 ]

The IRET opcode is 0xcf according to the Intel manual and also to objdump of my
vmlinux:

1ea8: 48 cf iretq

Fix the opcode in arch_decode_instruction().

The previous value (0xc5) seems to correspond to LDS.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170118132921.19319-1-jslaby@suse.cz
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
tools/objtool/arch/x86/decode.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -150,9 +150,9 @@ int arch_decode_instruction(struct elf *
*type = INSN_RETURN;
break;

- case 0xc5: /* iret */
case 0xca: /* retf */
case 0xcb: /* retf */
+ case 0xcf: /* iret */
*type = INSN_CONTEXT_SWITCH;
break;