The current rounding of "size" is wrong:
- If "start" is sufficiently near the next page boundary, "size"
is decremented by more than enough and the last page is lost.
- If "size" is sufficiently small, it is wrapped around and gets
a bogus value.
Signed-off-by: Masahiro Yamada <yamad...@jp.panasonic.com>
Acked-by: Geert Uytterhoeven <ge...@linux-m68k.org>
---
Changes in v2:
- Avoid wrap around of "size"
arch/arm/kernel/setup.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index f9c8639..d13f185 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -657,10 +657,13 @@ int __init arm_add_memory(u64 start, u64 size)
/*
* Ensure that start/size are aligned to a page boundary.
- * Size is appropriately rounded down, start is rounded up.
+ * Size is rounded down, start is rounded up.
*/
- size -= start & ~PAGE_MASK;
aligned_start = PAGE_ALIGN(start);
+ if (aligned_start > start + size)
+ size = 0;
+ else
+ size -= aligned_start - start;
#ifndef CONFIG_ARCH_PHYS_ADDR_T_64BIT
if (aligned_start > ULONG_MAX) {
--
1.9.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
