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authorMasahiro Yamada <yamada.m@jp.panasonic.com>2015-01-20 04:38:25 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2015-01-21 15:52:40 +0000
commit909ba297beb50981a9d12364688d3c5f3084c6eb (patch)
tree14080141f5359248a3f08b420dd8f56a666d61f0 /arch/arm
parent2d9ed7406fd24987b75f78fea8290202d8108f34 (diff)
downloadlinux-909ba297beb50981a9d12364688d3c5f3084c6eb.tar.gz
ARM: 8292/1: mm: fix size rounding-down of arm_add_memory() function
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 <yamada.m@jp.panasonic.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/kernel/setup.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index f9c86391103..d13f185e7bd 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) {