[PATCH] objtool: fix iret's opcode

[PATCH] objtool: fix iret's opcode

[Jiri Slaby]

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@suse.cz>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
---
 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

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

[Josh Poimboeuf]

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@suse.cz>
> Cc: Josh Poimboeuf <jpoimboe@redhat.com>
> Cc: Ingo Molnar <mingo@kernel.org>

Thanks!

Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>

> ---
>  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

[tip:core/urgent] objtool: Fix IRET's opcode

[tip-bot for Jiri Slaby]

Commit-ID:  b5b46c4740aed1538544f0fa849c5b76c7823469
Gitweb:     http://git.kernel.org/tip/b5b46c4740aed1538544f0fa849c5b76c7823469
Author:     Jiri Slaby <jslaby@suse.cz>
AuthorDate: Wed, 18 Jan 2017 14:29:21 +0100
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 19 Jan 2017 08:39:44 +0100

objtool: Fix IRET's opcode

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>
---
 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 5e0dea2..039636f 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;