[tip:x86/pti] x86/entry/32: Introduce SAVE_ALL_NMI and RESTORE_ALL_NMI

From: tip-bot for Joerg Roedel
Date: Thu Jul 19 2018 - 19:24:05 EST


Commit-ID: 8b376fae0514dc7ee04786e2327169e39d12e51b
Gitweb: https://git.kernel.org/tip/8b376fae0514dc7ee04786e2327169e39d12e51b
Author: Joerg Roedel <jroedel@xxxxxxx>
AuthorDate: Wed, 18 Jul 2018 11:40:46 +0200
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Fri, 20 Jul 2018 01:11:38 +0200

x86/entry/32: Introduce SAVE_ALL_NMI and RESTORE_ALL_NMI

These macros will be used in the NMI handler code and replace plain
SAVE_ALL and RESTORE_REGS there.

The NMI-specific CR3-switch will be added to these macros later.

Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Tested-by: Pavel Machek <pavel@xxxxxx>
Cc: "H . Peter Anvin" <hpa@xxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Juergen Gross <jgross@xxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Jiri Kosina <jkosina@xxxxxxx>
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: David Laight <David.Laight@xxxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: Eduardo Valentin <eduval@xxxxxxxxxx>
Cc: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: aliguori@xxxxxxxxxx
Cc: daniel.gruss@xxxxxxxxxxxxxx
Cc: hughd@xxxxxxxxxx
Cc: keescook@xxxxxxxxxx
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Waiman Long <llong@xxxxxxxxxx>
Cc: "David H . Gutteridge" <dhgutteridge@xxxxxxxxxxxx>
Cc: joro@xxxxxxxxxx
Link: https://lkml.kernel.org/r/1531906876-13451-10-git-send-email-joro@xxxxxxxxxx

---
arch/x86/entry/entry_32.S | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index a905e6215ea9..763592596727 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -181,6 +181,9 @@

.endm

+.macro SAVE_ALL_NMI
+ SAVE_ALL
+.endm
/*
* This is a sneaky trick to help the unwinder find pt_regs on the stack. The
* frame pointer is replaced with an encoded pointer to pt_regs. The encoding
@@ -227,6 +230,10 @@
POP_GS_EX
.endm

+.macro RESTORE_ALL_NMI pop=0
+ RESTORE_REGS pop=\pop
+.endm
+
.macro CHECK_AND_APPLY_ESPFIX
#ifdef CONFIG_X86_ESPFIX32
#define GDT_ESPFIX_SS PER_CPU_VAR(gdt_page) + (GDT_ENTRY_ESPFIX_SS * 8)
@@ -1161,7 +1168,7 @@ ENTRY(nmi)
#endif

pushl %eax # pt_regs->orig_ax
- SAVE_ALL
+ SAVE_ALL_NMI
ENCODE_FRAME_POINTER
xorl %edx, %edx # zero error code
movl %esp, %eax # pt_regs pointer
@@ -1189,7 +1196,7 @@ ENTRY(nmi)

.Lnmi_return:
CHECK_AND_APPLY_ESPFIX
- RESTORE_REGS 4
+ RESTORE_ALL_NMI pop=4
jmp .Lirq_return

#ifdef CONFIG_X86_ESPFIX32
@@ -1205,12 +1212,12 @@ ENTRY(nmi)
pushl 16(%esp)
.endr
pushl %eax
- SAVE_ALL
+ SAVE_ALL_NMI
ENCODE_FRAME_POINTER
FIXUP_ESPFIX_STACK # %eax == %esp
xorl %edx, %edx # zero error code
call do_nmi
- RESTORE_REGS
+ RESTORE_ALL_NMI
lss 12+4(%esp), %esp # back to espfix stack
jmp .Lirq_return
#endif