[PATCH 07/17] Enforce minimum alignment of 1 page on allocations. The efi_high_alloc() and efi_low_alloc() functions use the EFI_ALLOCATE_ADDRESS option to the EFI function allocate_pages(), which requires a minimum of page alignment, and rejects all other requests.
From: Roy Franz <hidden>
Date: 2013-08-07 03:45:35
Also in:
linux-efi, lkml
Subsystem:
extensible firmware interface (efi), the rest · Maintainers:
Ard Biesheuvel, Linus Torvalds
The existing code could fail to allocate depending on allocation size, as although repeated allocation attempts were made, none were guaranteed to be page aligned. Signed-off-by: Roy Franz <redacted> --- drivers/firmware/efi/efi-stub-helper.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
diff --git a/drivers/firmware/efi/efi-stub-helper.c b/drivers/firmware/efi/efi-stub-helper.c
index cd7701f..8582650 100644
--- a/drivers/firmware/efi/efi-stub-helper.c
+++ b/drivers/firmware/efi/efi-stub-helper.c@@ -105,6 +105,13 @@ static efi_status_t efi_high_alloc(efi_system_table_t *sys_table_arg, if (status != EFI_SUCCESS) goto fail; + /* Enforce minimum alignment that EFI requires when requesting + * a specific address. We are doing page-based allocations, + * so we must be aligned to a page. + */ + if (align < EFI_PAGE_SIZE) + align = EFI_PAGE_SIZE; + nr_pages = round_up(size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE; again: for (i = 0; i < map_size / desc_size; i++) {
@@ -184,6 +191,13 @@ static efi_status_t efi_low_alloc(efi_system_table_t *sys_table_arg, if (status != EFI_SUCCESS) goto fail; + /* Enforce minimum alignment that EFI requires when requesting + * a specific address. We are doing page-based allocations, + * so we must be aligned to a page. + */ + if (align < EFI_PAGE_SIZE) + align = EFI_PAGE_SIZE; + nr_pages = round_up(size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE; for (i = 0; i < map_size / desc_size; i++) { efi_memory_desc_t *desc;
--
1.7.10.4