From: Jan Beulich <jbeulich@novell.com>
Date: Wed, 17 Oct 2007 16:04:33 +0000 (+0200)
Subject: i386: avoid temporarily inconsistent pte-s
X-Git-Tag: v2.6.23.9~12
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=df84bfba736f56550a32e7a85ad518f3f8431b9c;p=thirdparty%2Fkernel%2Fstable.git

i386: avoid temporarily inconsistent pte-s

patch aa506dc7b12d03fbf8fd11aab752aed1aadd9c07 in mainline.

i386: avoid temporarily inconsistent pte-s

One more of these issues (which were considered fixed a few releases
back): other than on x86-64, i386 allows set_fixmap() to replace
already present mappings. Consequently, on PAE, care must be taken to
not update the high half of a pte while the low half is still holding
the old value.

 [tglx: arch/x86 adaptation]

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/arch/i386/mm/pgtable.c b/arch/i386/mm/pgtable.c
index 01437c46baae9..91faa59e2a5f8 100644
--- a/arch/i386/mm/pgtable.c
+++ b/arch/i386/mm/pgtable.c
@@ -97,8 +97,7 @@ static void set_pte_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
 	}
 	pte = pte_offset_kernel(pmd, vaddr);
 	if (pgprot_val(flags))
-		/* <pfn,flags> stored as-is, to permit clearing entries */
-		set_pte(pte, pfn_pte(pfn, flags));
+		set_pte_present(&init_mm, vaddr, pte, pfn_pte(pfn, flags));
 	else
 		pte_clear(&init_mm, vaddr, pte);