[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[PATCH 05/11] x86/entry: Move cld to the start of idtentry



From: Lai Jiangshan <laijs@xxxxxxxxxxxxxxxxx>

Make it next to CLAC

Suggested-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Lai Jiangshan <laijs@xxxxxxxxxxxxxxxxx>
---
 arch/x86/entry/entry_64.S | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 72ceb4b70822..ee1d4adcdab0 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -356,6 +356,7 @@ SYM_CODE_END(ret_from_fork)
 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 */
@@ -423,6 +424,7 @@ SYM_CODE_END(\asmsym)
 SYM_CODE_START(\asmsym)
        UNWIND_HINT_IRET_REGS
        ASM_CLAC
+       cld
 
        pushq   $-1                     /* ORIG_RAX: no syscall to restart */
 
@@ -478,6 +480,7 @@ 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
@@ -539,6 +542,7 @@ 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
@@ -853,7 +857,6 @@ 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
 
@@ -971,7 +974,6 @@ SYM_CODE_END(paranoid_exit)
  */
 SYM_CODE_START_LOCAL(error_entry)
        UNWIND_HINT_FUNC
-       cld
        testb   $3, CS+8(%rsp)
        jz      .Lerror_kernelspace
 
@@ -1104,6 +1106,7 @@ SYM_CODE_START(asm_exc_nmi)
         */
 
        ASM_CLAC
+       cld
 
        /* Use %rdx as our temp variable throughout */
        pushq   %rdx
@@ -1123,7 +1126,6 @@ SYM_CODE_START(asm_exc_nmi)
         */
 
        swapgs
-       cld
        FENCE_SWAPGS_USER_ENTRY
        SWITCH_TO_KERNEL_CR3 scratch_reg=%rdx
        movq    %rsp, %rdx
-- 
2.19.1.6.gb485710b




 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.