lkml.org 
[lkml]   [2017]   [Nov]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip:x86/asm] x86/entry/64: Use POP instead of MOV to restore regs on NMI return
Commit-ID:  471ee4832209e986029b9fabdaad57b1eecb856b
Gitweb: https://git.kernel.org/tip/471ee4832209e986029b9fabdaad57b1eecb856b
Author: Andy Lutomirski <luto@kernel.org>
AuthorDate: Thu, 2 Nov 2017 00:59:05 -0700
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 2 Nov 2017 11:04:40 +0100

x86/entry/64: Use POP instead of MOV to restore regs on NMI return

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

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.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/652a260f17a160789bc6a41d997f98249b73e2ab.1509609304.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
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 b5a0ea6..5b2f0bc 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
\
 
 \ /
  Last update: 2017-11-02 11:58    [W:0.456 / U:0.052 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site