From 1d6cd6ce0ed58595dabdfb310e53353d9fad0947 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Mon, 20 Oct 2014 15:31:57 +0200 Subject: UPSTREAM: arm64/efi: invert UEFI memory region reservation logic Instead of reserving the memory regions based on which types we know need to be reserved, consider only regions of the following types as free for general use by the OS: EFI_LOADER_CODE EFI_LOADER_DATA EFI_BOOT_SERVICES_CODE EFI_BOOT_SERVICES_DATA EFI_CONVENTIONAL_MEMORY Note that this also fixes a problem with the original code, which would misidentify a EFI_RUNTIME_SERVICES_DATA region as not reserved if it does not have the EFI_MEMORY_RUNTIME attribute set. However, it is perfectly legal for the firmware not to request a virtual mapping for EFI_RUNTIME_SERVICES_DATA regions that contain configuration tables, in which case the EFI_MEMORY_RUNTIME attribute would not be set. Acked-by: Roy Franz Signed-off-by: Ard Biesheuvel (cherry picked from commit 61139eb04056bba69aeef6c481802c4ea028bf4d) Signed-off-by: Tomasz Figa Bug: 24475017 Change-Id: I427af832faaf82100c1f3ffb3e1649dd05e6d280 Signed-off-by: Kees Cook --- arch/arm64/kernel/efi.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c index 95c49ebc660d..2e829148fb36 100644 --- a/arch/arm64/kernel/efi.c +++ b/arch/arm64/kernel/efi.c @@ -125,17 +125,17 @@ out: */ static __init int is_reserve_region(efi_memory_desc_t *md) { - if (!is_normal_ram(md)) + switch (md->type) { + case EFI_LOADER_CODE: + case EFI_LOADER_DATA: + case EFI_BOOT_SERVICES_CODE: + case EFI_BOOT_SERVICES_DATA: + case EFI_CONVENTIONAL_MEMORY: return 0; - - if (md->attribute & EFI_MEMORY_RUNTIME) - return 1; - - if (md->type == EFI_ACPI_RECLAIM_MEMORY || - md->type == EFI_RESERVED_TYPE) - return 1; - - return 0; + default: + break; + } + return is_normal_ram(md); } static __init void reserve_regions(void) -- cgit v1.2.3