x86/mm/init.c: devmem_is_allowed() off by one

Fix an off-by-one error in devmem_is_allowed(), which allows accesses to
physical addresses 0x100000-0x100fff, an extra page past 1MB.

Signed-off-by: T Makphaibulchoke <tmac@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index e0e6990723e982e12f425f2fdd26113725f2d52a..ab1f6a93b527c9bd50acc12a52e9ce157f2cc48b 100644 (file)
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -319,7 +319,7 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
  */
 int devmem_is_allowed(unsigned long pagenr)
 {
-       if (pagenr <= 256)
+       if (pagenr < 256)
                return 1;
        if (iomem_is_exclusive(pagenr << PAGE_SHIFT))
                return 0;