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From: Borislav Petkov <bp@alien8.de>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: X86 ML <x86@kernel.org>, LKML <linux-kernel@vger.kernel.org>,
	Borislav Petkov <bp@suse.de>
Subject: [PATCH 5/5 -v2] x86, head_32: Clear DF much earlier
Date: Sat,  9 Feb 2013 23:08:49 +0100	[thread overview]
Message-ID: <1360447729-4256-1-git-send-email-bp@alien8.de> (raw)
In-Reply-To: <20130209212342.GA5556@pd.tnic>

From: Borislav Petkov <bp@suse.de>

All GCC versions expect the direction flag to be cleared (DF=0) so move
this to the default entry point for each core.

Signed-off-by: Borislav Petkov <bp@suse.de>
---
 arch/x86/kernel/head_32.S | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index 75e96d7e4e5f..8b2a8a824fc6 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -322,10 +322,11 @@ default_entry:
  * debugger if this code is traced. Best to initialize before switching to
  * protected mode.
  */
-
 	pushl $0
 	popfl
 
+	cld				# GCC wants DF=0 at all times
+
 /*
  * New page tables may be in 4Mbyte page mode and may be using the global pages.
  *
@@ -463,7 +464,6 @@ is486:
 	xorl %eax,%eax			# Clear LDT
 	lldt %ax
 
-	cld			# gcc2 wants the direction flag cleared at all times
 	pushl $0		# fake return address for unwinder
 	jmp *(initial_code)
 
-- 
1.8.1.3.535.ga923c31


  reply	other threads:[~2013-02-09 22:08 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-02-09 19:52 [PATCH 0/5] x86, head_32: Some cleanups, -v2 Borislav Petkov
2013-02-09 19:52 ` [PATCH 1/5] x86, head_32: Remove i386 pieces Borislav Petkov
2013-02-09 19:52 ` [PATCH 2/5] x86: Detect CPUID support early at boot Borislav Petkov
2013-02-09 19:52 ` [PATCH 3/5] x86, head_32: Remove second CPUID detection from default_entry Borislav Petkov
2013-02-09 19:52 ` [PATCH 4/5] x86, head_32: Give the 6 label a real name Borislav Petkov
2013-02-09 19:52 ` [PATCH 5/5] x86, head_32: Remove an old gcc2 fix Borislav Petkov
2013-02-09 20:51   ` H. Peter Anvin
2013-02-09 20:52   ` H. Peter Anvin
2013-02-09 21:23     ` Borislav Petkov
2013-02-09 22:08       ` Borislav Petkov [this message]
2013-02-09 22:23       ` H. Peter Anvin
2013-02-09 23:13         ` Borislav Petkov
2013-02-09 23:16           ` [PATCH 2/5 -v2.1] x86: Detect CPUID support early at boot Borislav Petkov
2013-02-10  4:34             ` H. Peter Anvin
2013-02-10  8:36               ` Borislav Petkov
2013-02-10 15:10                 ` H. Peter Anvin

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