x86, 64-bit: Move K8 B step iret fixup to fault entry asm
Move the handling of truncated %rip from an iret fault to the fault
entry path.
This allows x86-64 to use the standard search_extable() function.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <1255357103-5418-1-git-send-email-brgerst@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index b5c061f..af0f4b22 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -1491,12 +1491,17 @@
leaq irq_return(%rip),%rcx
cmpq %rcx,RIP+8(%rsp)
je error_swapgs
- movl %ecx,%ecx /* zero extend */
- cmpq %rcx,RIP+8(%rsp)
- je error_swapgs
+ movl %ecx,%eax /* zero extend */
+ cmpq %rax,RIP+8(%rsp)
+ je bstep_iret
cmpq $gs_change,RIP+8(%rsp)
je error_swapgs
jmp error_sti
+
+bstep_iret:
+ /* Fix truncated RIP */
+ movq %rcx,RIP+8(%rsp)
+ je error_swapgs
END(error_entry)