linux-kernel - [PATCH 15/17] x86: code shrink in paranoid

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Date:	Fri,  8 Aug 2014 19:44:38 +0200
From:	Denys Vlasenko <dvlasenk@...hat.com>
To:	linux-kernel@...r.kernel.org
Cc:	Denys Vlasenko <dvlasenk@...hat.com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Oleg Nesterov <oleg@...hat.com>,
	"H. Peter Anvin" <hpa@...or.com>,
	Andy Lutomirski <luto@...capital.net>,
	Frederic Weisbecker <fweisbec@...il.com>,
	X86 ML <x86@...nel.org>, Alexei Starovoitov <ast@...mgrid.com>,
	Will Drewry <wad@...omium.org>,
	Kees Cook <keescook@...omium.org>
Subject: [PATCH 15/17] x86: code shrink in paranoid_exit

RESTORE_EXTRA_REGS + RESTORE_C_REGS looks small, but it's
a lot of instructions (fourteen). Let's reuse them.

Signed-off-by: Denys Vlasenko <dvlasenk@...hat.com>
CC: Linus Torvalds <torvalds@...ux-foundation.org>
CC: Oleg Nesterov <oleg@...hat.com>
CC: "H. Peter Anvin" <hpa@...or.com>
CC: Andy Lutomirski <luto@...capital.net>
CC: Frederic Weisbecker <fweisbec@...il.com>
CC: X86 ML <x86@...nel.org>
CC: Alexei Starovoitov <ast@...mgrid.com>
CC: Will Drewry <wad@...omium.org>
CC: Kees Cook <keescook@...omium.org>
CC: linux-kernel@...r.kernel.org
---
 arch/x86/kernel/entry_64.S | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index f652ac6..7bc8c24 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -1288,12 +1288,10 @@ ENTRY(paranoid_exit)
 paranoid_swapgs:
 	TRACE_IRQS_IRETQ 0
 	SWAPGS_UNSAFE_STACK
-	RESTORE_EXTRA_REGS
-	RESTORE_C_REGS
-	REMOVE_PTREGS_FROM_STACK 8
-	jmp irq_return
+	jmp paranoid_restore1
 paranoid_restore:
 	TRACE_IRQS_IRETQ_DEBUG 0
+paranoid_restore1:
 	RESTORE_EXTRA_REGS
 	RESTORE_C_REGS
 	REMOVE_PTREGS_FROM_STACK 8
-- 
1.8.1.4

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