path: root/drivers/firmware/efi/memmap.c
diff options
authorMatt Fleming <matt@codeblueprint.co.uk>2016-09-16 15:12:47 +0100
committerMatt Fleming <matt@codeblueprint.co.uk>2016-09-20 15:43:31 +0100
commit92dc33501bfba74655dbf3ec63ea82d040fd6d58 (patch)
tree38187bc2a39d00331d2898ae7c2a204054ad68e7 /drivers/firmware/efi/memmap.c
parent5465fe0fc3316f7cdda66732a7986f4ebe76d949 (diff)
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 <umgwanakikbuti@gmail.com> Reported-by: Mike Krinkin <krinkin.m.u@gmail.com> Tested-by: Mike Krinkin <krinkin.m.u@gmail.com> Cc: Peter Jones <pjones@redhat.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Taku Izumi <izumi.taku@jp.fujitsu.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Diffstat (limited to 'drivers/firmware/efi/memmap.c')
1 files changed, 11 insertions, 0 deletions
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) {