Messages in this thread | | | Subject | Re: [PATCH] ARM: memblock limit must be pmd-aligned | From | Laura Abbott <> | Date | Mon, 26 Jun 2017 16:43:58 -0700 |
| |
On 06/26/2017 10:23 AM, Doug Berger wrote: > There is a path through the adjust_lowmem_bounds() routine where if all > memory regions start and end on pmd-aligned addresses the memblock_limit > will be set to arm_lowmem_limit. > > However, since arm_lowmem_limit can be affected by the vmalloc early > parameter, the value of arm_lowmem_limit may not be pmd-aligned. This > commit corrects this oversight such that memblock_limit is always rounded > down to pmd-alignment. > > The pmd containing arm_lowmem_limit is cleared by prepare_page_table() > and without this commit it is possible for early_alloc() to allocate > unmapped memory in that range when mapping the lowmem. >
Do you have an example system or configuration where you see this crash?
Thanks, Laura
> Signed-off-by: Doug Berger <opendmb@gmail.com> > --- > arch/arm/mm/mmu.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c > index 31af3cb59a60..2ae4f9c9d757 100644 > --- a/arch/arm/mm/mmu.c > +++ b/arch/arm/mm/mmu.c > @@ -1226,7 +1226,7 @@ void __init adjust_lowmem_bounds(void) > if (memblock_limit) > memblock_limit = round_down(memblock_limit, PMD_SIZE); > if (!memblock_limit) > - memblock_limit = arm_lowmem_limit; > + memblock_limit = round_down(arm_lowmem_limit, PMD_SIZE); > > if (!IS_ENABLED(CONFIG_HIGHMEM) || cache_is_vipt_aliasing()) { > if (memblock_end_of_DRAM() > arm_lowmem_limit) { >
| |