Re: [PATCH] objtool: fix iret's opcode

From: Josh Poimboeuf
Date: Wed Jan 18 2017 - 11:25:22 EST


On Wed, Jan 18, 2017 at 02:29:21PM +0100, Jiri Slaby wrote:
> iret 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@xxxxxxx>
> Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>

Thanks!

Acked-by: 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 5e0dea2cdc01..039636ffb6c8 100644
> --- a/tools/objtool/arch/x86/decode.c
> +++ b/tools/objtool/arch/x86/decode.c
> @@ -150,9 +150,9 @@ int arch_decode_instruction(struct elf *elf, struct section *sec,
> *type = INSN_RETURN;
> break;
>
> - case 0xc5: /* iret */
> case 0xca: /* retf */
> case 0xcb: /* retf */
> + case 0xcf: /* iret */
> *type = INSN_CONTEXT_SWITCH;
> break;
>
> --
> 2.11.0
>

--
Josh