Commit 74c102c9 authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Catalin Marinas

arm64: efi: avoid block mappings for unaligned UEFI memory regions

When running the OS with a page size > 4 KB, we need to round up mappings
for regions that are not aligned to the OS's page size. We already avoid
block mappings for EfiRuntimeServicesCode/Data regions for other reasons,
but in the unlikely event that other unaliged regions exists that have the
EFI_MEMORY_RUNTIME attribute set, ensure that unaligned regions are always
mapped down to pages. This way, the overlapping page is guaranteed not to
be covered by a block mapping that needs to be split.
Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent bd264d04
...@@ -65,6 +65,20 @@ int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md) ...@@ -65,6 +65,20 @@ int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md)
bool allow_block_mappings = (md->type != EFI_RUNTIME_SERVICES_CODE && bool allow_block_mappings = (md->type != EFI_RUNTIME_SERVICES_CODE &&
md->type != EFI_RUNTIME_SERVICES_DATA); md->type != EFI_RUNTIME_SERVICES_DATA);
if (!PAGE_ALIGNED(md->phys_addr) ||
!PAGE_ALIGNED(md->num_pages << EFI_PAGE_SHIFT)) {
/*
* If the end address of this region is not aligned to page
* size, the mapping is rounded up, and may end up sharing a
* page frame with the next UEFI memory region. If we create
* a block entry now, we may need to split it again when mapping
* the next region, and support for that is going to be removed
* from the MMU routines. So avoid block mappings altogether in
* that case.
*/
allow_block_mappings = false;
}
create_pgd_mapping(mm, md->phys_addr, md->virt_addr, create_pgd_mapping(mm, md->phys_addr, md->virt_addr,
md->num_pages << EFI_PAGE_SHIFT, md->num_pages << EFI_PAGE_SHIFT,
__pgprot(prot_val | PTE_NG), allow_block_mappings); __pgprot(prot_val | PTE_NG), allow_block_mappings);
......
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