From: Roy Franz Date: Sun, 22 Sep 2013 22:45:30 +0000 (-0700) Subject: efi: Enforce minimum alignment of 1 page on allocations. X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=38dd9c02c3f2ed461165db22b93fae7f3ddde9ac;p=linux-beck.git efi: 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. 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 Acked-by: Mark Salter Reviewed-by: Grant Likely Signed-off-by: Matt Fleming --- diff --git a/drivers/firmware/efi/efi-stub-helper.c b/drivers/firmware/efi/efi-stub-helper.c index 2f528fb541f9..a25675833598 100644 --- a/drivers/firmware/efi/efi-stub-helper.c +++ b/drivers/firmware/efi/efi-stub-helper.c @@ -101,6 +101,14 @@ 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++) { @@ -179,6 +187,14 @@ 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;