[PATCH 5.15 008/136] x86/entry: Move CLD to the start of the idtentry macro

Greg Kroah-Hartman
2022-08-29T11:04:38Z

From: Lai Jiangshan <jiangshan.ljs@antgroup.com>

commit c64cc2802a784ecfd25d39945e57e7a147854a5b upstream.

Move it after CLAC.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220503032107.680190-5-jiangshanlai@gmail.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/entry/entry_64.S | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -373,6 +373,7 @@ SYM_CODE_END(xen_error_entry)
SYM_CODE_START(\asmsym)
UNWIND_HINT_IRET_REGS offset=\has_error_code*8
ASM_CLAC
+ cld

.if \has_error_code == 0
pushq $-1 /* ORIG_RAX: no syscall to restart */
@@ -440,6 +441,7 @@ SYM_CODE_END(\asmsym)
SYM_CODE_START(\asmsym)
UNWIND_HINT_IRET_REGS
ASM_CLAC
+ cld

pushq $-1 /* ORIG_RAX: no syscall to restart */

@@ -495,6 +497,7 @@ SYM_CODE_END(\asmsym)
SYM_CODE_START(\asmsym)
UNWIND_HINT_IRET_REGS
ASM_CLAC
+ cld

/*
* If the entry is from userspace, switch stacks and treat it as
@@ -557,6 +560,7 @@ SYM_CODE_END(\asmsym)
SYM_CODE_START(\asmsym)
UNWIND_HINT_IRET_REGS offset=8
ASM_CLAC
+ cld

/* paranoid_entry returns GS information for paranoid_exit in EBX. */
call paranoid_entry
@@ -876,7 +880,6 @@ SYM_CODE_END(xen_failsafe_callback)
*/
SYM_CODE_START_LOCAL(paranoid_entry)
UNWIND_HINT_FUNC
- cld
PUSH_AND_CLEAR_REGS save_ret=1
ENCODE_FRAME_POINTER 8

@@ -1012,7 +1015,6 @@ SYM_CODE_END(paranoid_exit)
*/
SYM_CODE_START_LOCAL(error_entry)
UNWIND_HINT_FUNC
- cld

PUSH_AND_CLEAR_REGS save_ret=1
ENCODE_FRAME_POINTER 8
@@ -1155,6 +1157,7 @@ SYM_CODE_START(asm_exc_nmi)
*/

ASM_CLAC
+ cld

/* Use %rdx as our temp variable throughout */
pushq %rdx
@@ -1174,7 +1177,6 @@ SYM_CODE_START(asm_exc_nmi)
*/

swapgs
- cld
FENCE_SWAPGS_USER_ENTRY
SWITCH_TO_KERNEL_CR3 scratch_reg=%rdx
movq %rsp, %rdx