linux-kernel - [tip:x86/asm] x86/asm/entry/64: Shrink code in 'paranoid

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Message-ID: <tip-0d55083698ed2f498e5682c5c252e6b7224890be@git.kernel.org>
Date:	Wed, 4 Mar 2015 14:53:59 -0800
From:	tip-bot for Denys Vlasenko <tipbot@...or.com>
To:	linux-tip-commits@...r.kernel.org
Cc:	tglx@...utronix.de, torvalds@...ux-foundation.org,
	mingo@...nel.org, luto@...capital.net, fweisbec@...il.com,
	ast@...mgrid.com, dvlasenk@...hat.com, bp@...en8.de,
	keescook@...omium.org, linux-kernel@...r.kernel.org, hpa@...or.com,
	wad@...omium.org, oleg@...hat.com
Subject: [tip:x86/asm] x86/asm/entry/64: Shrink code in 'paranoid_exit'

Commit-ID:  0d55083698ed2f498e5682c5c252e6b7224890be
Gitweb:     http://git.kernel.org/tip/0d55083698ed2f498e5682c5c252e6b7224890be
Author:     Denys Vlasenko <dvlasenk@...hat.com>
AuthorDate: Thu, 26 Feb 2015 14:40:29 -0800
Committer:  Ingo Molnar <mingo@...nel.org>
CommitDate: Wed, 4 Mar 2015 22:50:50 +0100

x86/asm/entry/64: Shrink code 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>
[ Cleaned up the labels. ]
Signed-off-by: Andy Lutomirski <luto@...capital.net>
Cc: Alexei Starovoitov <ast@...mgrid.com>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Frederic Weisbecker <fweisbec@...il.com>
Cc: H. Peter Anvin <hpa@...or.com>
Cc: Kees Cook <keescook@...omium.org>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Oleg Nesterov <oleg@...hat.com>
Cc: Will Drewry <wad@...omium.org>
Link: http://lkml.kernel.org/r/1421272101-16847-2-git-send-email-dvlasenk@redhat.com
Link: http://lkml.kernel.org/r/59d71848cee3ec9eb48c0252e602efd6bd560e3c.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
 arch/x86/kernel/entry_64.S | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 695f4d4..8fafed9 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -1285,15 +1285,13 @@ ENTRY(paranoid_exit)
 	DISABLE_INTERRUPTS(CLBR_NONE)
 	TRACE_IRQS_OFF_DEBUG
 	testl %ebx,%ebx				/* swapgs needed? */
-	jnz paranoid_restore
+	jnz paranoid_exit_no_swapgs
 	TRACE_IRQS_IRETQ 0
 	SWAPGS_UNSAFE_STACK
-	RESTORE_EXTRA_REGS
-	RESTORE_C_REGS
-	REMOVE_PT_GPREGS_FROM_STACK 8
-	INTERRUPT_RETURN
-paranoid_restore:
+	jmp paranoid_exit_restore
+paranoid_exit_no_swapgs:
 	TRACE_IRQS_IRETQ_DEBUG 0
+paranoid_exit_restore:
 	RESTORE_EXTRA_REGS
 	RESTORE_C_REGS
 	REMOVE_PT_GPREGS_FROM_STACK 8
--
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