[PATCH v2 08/20] x86/entry/64: Use POP instead of MOV to restore regs on NMI return

From: Andy Lutomirski
Date: Thu Nov 02 2017 - 04:00:04 EST


This gets rid of the last user of the old RESTORE_..._REGS infrastructure.

Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
---
arch/x86/entry/entry_64.S | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 2e7f4952af94..f0f842124aa9 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1559,11 +1559,14 @@ end_repeat_nmi:
nmi_swapgs:
SWAPGS_UNSAFE_STACK
nmi_restore:
- RESTORE_EXTRA_REGS
- RESTORE_C_REGS
+ POP_EXTRA_REGS
+ POP_C_REGS

- /* Point RSP at the "iret" frame. */
- REMOVE_PT_GPREGS_FROM_STACK 6*8
+ /*
+ * Skip orig_ax and the "outermost" frame to point RSP at the "iret"
+ * at the "iret" frame.
+ */
+ addq $6*8, %rsp

/*
* Clear "NMI executing". Set DF first so that we can easily
--
2.13.6