[PATCH] xen: fix upper bound of pmd loop in xen_cleanhighmap()

[PATCH] xen: fix upper bound of pmd loop in xen_cleanhighmap()

[Juergen Gross]

xen_cleanhighmap() is operating on level2_kernel_pgt only. The upper
bound of the loop setting non-kernel-image entries to zero should not
exceed the size of level2_kernel_pgt.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Juergen Gross <jgross@suse.com>
---
 arch/x86/xen/mmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 478a2de..2693b7e 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1113,7 +1113,7 @@ static void __init xen_cleanhighmap(unsigned long vaddr,
 
 	/* NOTE: The loop is more greedy than the cleanup_highmap variant.
 	 * We include the PMD passed in on _both_ boundaries. */
-	for (; vaddr <= vaddr_end && (pmd < (level2_kernel_pgt + PAGE_SIZE));
+	for (; vaddr <= vaddr_end && (pmd < (level2_kernel_pgt + PTRS_PER_PMD));
 			pmd++, vaddr += PMD_SIZE) {
 		if (pmd_none(*pmd))
 			continue;
-- 
2.6.6

Re: [Xen-devel] [PATCH] xen: fix upper bound of pmd loop in xen_cleanhighmap()

[David Vrabel]

On 23/06/16 06:12, Juergen Gross wrote:
> xen_cleanhighmap() is operating on level2_kernel_pgt only. The upper
> bound of the loop setting non-kernel-image entries to zero should not
> exceed the size of level2_kernel_pgt.

Applied to for-linus-4.7b, thanks.

David