On platforms where the firmware uses DXE, but which do not implement the EFI Memory Attribute Protocol, we implement W^X support using DXE's set_memory_attributes() call. This call will fail without making any changes if an attribute is set that isn't supported on the platform. This patch changes efi_adjust_memory_range_protection() to avoid trying to set any attribute bits that aren't set in the memory region's capability flags. Signed-off-by: Peter Jones <pjones@xxxxxxxxxx> --- drivers/firmware/efi/libstub/mem.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/firmware/efi/libstub/mem.c b/drivers/firmware/efi/libstub/mem.c index d10996e4eb0..d52841adcc2 100644 --- a/drivers/firmware/efi/libstub/mem.c +++ b/drivers/firmware/efi/libstub/mem.c @@ -192,6 +192,7 @@ static efi_status_t adjust_mem_attrib_dxe(efi_physical_addr_t rounded_start, desc.attributes &= ~(EFI_MEMORY_RO | EFI_MEMORY_XP); desc.attributes |= attributes; + desc.attributes &= desc.capabilities; unprotect_start = max(rounded_start, desc.base_address); unprotect_size = min(rounded_end, next) - unprotect_start; -- 2.38.1
