[3.16-stable,71/87] x86/xen: fix upper bound of pmd loop in xen_cleanhighmap()

Message ID 20170505194745.3627137-72-arnd@arndb.de
State New
Headers show
Series
  • build warnings and errors
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Commit Message

Arnd Bergmann May 5, 2017, 7:47 p.m.
From: Juergen Gross <jgross@suse.com>


commit 1cf38741308c64d08553602b3374fb39224eeb5a upstream.

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>

Signed-off-by: David Vrabel <david.vrabel@citrix.com>

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

---
 arch/x86/xen/mmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

-- 
2.9.0

Patch

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 16fb0099b7f2..f05f2d897a67 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1187,7 +1187,7 @@  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;