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SubjectRe: [PATCH v2] ARM: mm: fix size rounding-down of arm_add_memory() function
Hello Russell King,

Could you apply this patch for arm_add_memory() fix, please ?


Thanks,
Masahiro Yamada


On Mon, 22 Dec 2014 10:09:32 +0100
Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote:

> On 22 December 2014 at 04:17, Masahiro Yamada <yamada.m@jp.panasonic.com> wrote:
> > 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>
>
>
> > ---
> >
> > 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
> >
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel




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