From 92dc33501bfba74655dbf3ec63ea82d040fd6d58 Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Fri, 16 Sep 2016 15:12:47 +0100 Subject: 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 --- drivers/firmware/efi/memmap.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'drivers') 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) { -- cgit v1.2.3-70-g09d2