| Message ID | 20181106113732.16351-2-ard.biesheuvel@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | arm/efi: fix memblock reallocation crash due to persistent reservations | expand |
On Tue, Nov 06, 2018 at 12:37:29PM +0100, Ard Biesheuvel wrote: > Bhupesh reports that having numerous memblock reservations at early > boot may result in the following crash: > > Unable to handle kernel paging request at virtual address ffff80003ffe0000 > ... > Call trace: > __memcpy+0x110/0x180 > memblock_add_range+0x134/0x2e8 > memblock_reserve+0x70/0xb8 > memblock_alloc_base_nid+0x6c/0x88 > __memblock_alloc_base+0x3c/0x4c > memblock_alloc_base+0x28/0x4c > memblock_alloc+0x2c/0x38 > early_pgtable_alloc+0x20/0xb0 > paging_init+0x28/0x7f8 > > This is caused by the fact that we permit memblock resizing before the > linear mapping is up, and so the memblock_reserved() array is moved > into memory that is not mapped yet. > > So let's ensure that this crash can no longer occur, by deferring to > call to memblock_allow_resize() to after the linear mapping has been > created. > > Reported-by: Bhupesh Sharma <bhsharma@redhat.com> > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > --- > arch/arm64/mm/init.c | 2 -- > arch/arm64/mm/mmu.c | 2 ++ > 2 files changed, 2 insertions(+), 2 deletions(-) Thanks for posting this so quickly. Acked-by: Will Deacon <will.deacon@arm.com> Bhupesh -- please can you give this series a spin and confirm that it fixes the problem you were seeing? Thanks, Will
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 9d9582cac6c4..9b432d9fcada 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -483,8 +483,6 @@ void __init arm64_memblock_init(void) high_memory = __va(memblock_end_of_DRAM() - 1) + 1; dma_contiguous_reserve(arm64_dma_phys_limit); - - memblock_allow_resize(); } void __init bootmem_init(void) diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 394b8d554def..d1d6601b385d 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -659,6 +659,8 @@ void __init paging_init(void) memblock_free(__pa_symbol(init_pg_dir), __pa_symbol(init_pg_end) - __pa_symbol(init_pg_dir)); + + memblock_allow_resize(); } /*
Bhupesh reports that having numerous memblock reservations at early boot may result in the following crash: Unable to handle kernel paging request at virtual address ffff80003ffe0000 ... Call trace: __memcpy+0x110/0x180 memblock_add_range+0x134/0x2e8 memblock_reserve+0x70/0xb8 memblock_alloc_base_nid+0x6c/0x88 __memblock_alloc_base+0x3c/0x4c memblock_alloc_base+0x28/0x4c memblock_alloc+0x2c/0x38 early_pgtable_alloc+0x20/0xb0 paging_init+0x28/0x7f8 This is caused by the fact that we permit memblock resizing before the linear mapping is up, and so the memblock_reserved() array is moved into memory that is not mapped yet. So let's ensure that this crash can no longer occur, by deferring to call to memblock_allow_resize() to after the linear mapping has been created. Reported-by: Bhupesh Sharma <bhsharma@redhat.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- arch/arm64/mm/init.c | 2 -- arch/arm64/mm/mmu.c | 2 ++ 2 files changed, 2 insertions(+), 2 deletions(-) -- 2.19.1