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| author | Masahiro Yamada <yamada.m@jp.panasonic.com> | 2015-01-20 06:38:25 +0300 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2015-01-21 18:52:40 +0300 |
| commit | 909ba297beb50981a9d12364688d3c5f3084c6eb (patch) | |
| tree | 14080141f5359248a3f08b420dd8f56a666d61f0 | |
| parent | 2d9ed7406fd24987b75f78fea8290202d8108f34 (diff) | |
| download | linux-909ba297beb50981a9d12364688d3c5f3084c6eb.tar.xz | |
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>
| -rw-r--r-- | arch/arm/kernel/setup.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index f9c863911038..d13f185e7bd5 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) { |