From: Zachary Amsden <zach@vmware.com>
Date: Wed, 22 Aug 2007 01:30:36 +0000 (-0700)
Subject: Fix lazy mode vmalloc synchronization for paravirt
X-Git-Tag: v2.6.23-rc4~94
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8b14cb9953c6b569327e9372718cff09a98f9589;p=linux-2.6

Fix lazy mode vmalloc synchronization for paravirt

Touching vmalloc memory in the middle of a lazy mode update can generate
a kernel PDE update, which must be flushed immediately.  The fix is to
leave lazy mode when doing a vmalloc sync.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/arch/i386/mm/fault.c b/arch/i386/mm/fault.c
index 01ffdd4964..fcb38e7f35 100644
--- a/arch/i386/mm/fault.c
+++ b/arch/i386/mm/fault.c
@@ -249,9 +249,10 @@ static inline pmd_t *vmalloc_sync_one(pgd_t *pgd, unsigned long address)
 	pmd_k = pmd_offset(pud_k, address);
 	if (!pmd_present(*pmd_k))
 		return NULL;
-	if (!pmd_present(*pmd))
+	if (!pmd_present(*pmd)) {
 		set_pmd(pmd, *pmd_k);
-	else
+		arch_flush_lazy_mmu_mode();
+	} else
 		BUG_ON(pmd_page(*pmd) != pmd_page(*pmd_k));
 	return pmd_k;
 }