On 22 December 2014 at 04:17, Masahiro Yamada <[email protected]> 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 <[email protected]> > Acked-by: Geert Uytterhoeven <[email protected]>
Acked-by: Ard Biesheuvel <[email protected]> > --- > > 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 [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
