diff options
Diffstat (limited to 'drivers/firmware/efi/efi.c')
| -rw-r--r-- | drivers/firmware/efi/efi.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 521a541d02ad..4b7cf7bc0ded 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * efi.c - EFI subsystem * @@ -9,8 +10,6 @@ * allowing the efivarfs to be mounted or the efivars module to be loaded. * The existance of /sys/firmware/efi may also be used by userspace to * determine that the system supports EFI. - * - * This file is released under the GPLv2. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt @@ -1010,14 +1009,16 @@ int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size) /* first try to find a slot in an existing linked list entry */ for (prsv = efi_memreserve_root->next; prsv; prsv = rsv->next) { - rsv = __va(prsv); + rsv = memremap(prsv, sizeof(*rsv), MEMREMAP_WB); index = atomic_fetch_add_unless(&rsv->count, 1, rsv->size); if (index < rsv->size) { rsv->entry[index].base = addr; rsv->entry[index].size = size; + memunmap(rsv); return 0; } + memunmap(rsv); } /* no slot found - allocate a new linked list entry */ @@ -1025,7 +1026,13 @@ int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size) if (!rsv) return -ENOMEM; - rsv->size = EFI_MEMRESERVE_COUNT(PAGE_SIZE); + /* + * The memremap() call above assumes that a linux_efi_memreserve entry + * never crosses a page boundary, so let's ensure that this remains true + * even when kexec'ing a 4k pages kernel from a >4k pages kernel, by + * using SZ_4K explicitly in the size calculation below. + */ + rsv->size = EFI_MEMRESERVE_COUNT(SZ_4K); atomic_set(&rsv->count, 1); rsv->entry[0].base = addr; rsv->entry[0].size = size; |