linux-kernel - Re: [PATCH 5/5] x86, head_32: Remove an old gcc2 fix

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Date:	Sat, 9 Feb 2013 22:23:42 +0100
From:	Borislav Petkov <bp@...en8.de>
To:	"H. Peter Anvin" <hpa@...or.com>
Cc:	X86 ML <x86@...nel.org>, LKML <linux-kernel@...r.kernel.org>,
	Borislav Petkov <bp@...e.de>
Subject: Re: [PATCH 5/5] x86, head_32: Remove an old gcc2 fix

On Sat, Feb 09, 2013 at 12:52:01PM -0800, H. Peter Anvin wrote:
> However... DF should have been cleared long before this...

How about we do this at the beginning of default_entry where we clear
EFLAGS too:

diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index fc56613224c3..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.
  *
--

-- 
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
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