From: Matt Fleming Date: Fri, 16 Sep 2016 14:12:47 +0000 (+0100) Subject: x86/efi: Round EFI memmap reservations to EFI_PAGE_SIZE X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=92dc33501bfba74655dbf3ec63ea82d040fd6d58;p=linux-beck.git x86/efi: Round EFI memmap reservations to EFI_PAGE_SIZE Mike Galbraith reported that his machine started rebooting during boot after, commit 8e80632fb23f ("efi/esrt: Use efi_mem_reserve() and avoid a kmalloc()") The ESRT table on his machine is 56 bytes and at no point in the efi_arch_mem_reserve() call path is that size rounded up to EFI_PAGE_SIZE, nor is the start address on an EFI_PAGE_SIZE boundary. Since the EFI memory map only deals with whole pages, inserting an EFI memory region with 56 bytes results in a new entry covering zero pages, and completely screws up the calculations for the old regions that were trimmed. Round all sizes upwards, and start addresses downwards, to the nearest EFI_PAGE_SIZE boundary. Additionally, efi_memmap_insert() expects the mem::range::end value to be one less than the end address for the region. Reported-by: Mike Galbraith Reported-by: Mike Krinkin Tested-by: Mike Krinkin Cc: Peter Jones Cc: Ard Biesheuvel Cc: Mark Rutland Cc: Taku Izumi Signed-off-by: Matt Fleming --- diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c index f14b7a9da24b..10aca63a50d7 100644 --- a/arch/x86/platform/efi/quirks.c +++ b/arch/x86/platform/efi/quirks.c @@ -201,8 +201,12 @@ void __init efi_arch_mem_reserve(phys_addr_t addr, u64 size) return; } + size += addr % EFI_PAGE_SIZE; + size = round_up(size, EFI_PAGE_SIZE); + addr = round_down(addr, EFI_PAGE_SIZE); + mr.range.start = addr; - mr.range.end = addr + size; + mr.range.end = addr + size - 1; mr.attribute = md.attribute | EFI_MEMORY_RUNTIME; num_entries = efi_memmap_split_count(&md, &mr.range); diff --git a/drivers/firmware/efi/memmap.c b/drivers/firmware/efi/memmap.c index cd96086fd851..f03ddecd232b 100644 --- a/drivers/firmware/efi/memmap.c +++ b/drivers/firmware/efi/memmap.c @@ -225,6 +225,17 @@ void __init efi_memmap_insert(struct efi_memory_map *old_memmap, void *buf, m_end = mem->range.end; m_attr = mem->attribute; + /* + * The EFI memory map deals with regions in EFI_PAGE_SIZE + * units. Ensure that the region described by 'mem' is aligned + * correctly. + */ + if (!IS_ALIGNED(m_start, EFI_PAGE_SIZE) || + !IS_ALIGNED(m_end + 1, EFI_PAGE_SIZE)) { + WARN_ON(1); + return; + } + for (old = old_memmap->map, new = buf; old < old_memmap->map_end; old += old_memmap->desc_size, new += old_memmap->desc_size) {