efi: libstub: use EFI_LOADER_CODE region when moving the kernel in memory

The EFI spec is not very clear about which permissions are being given
when allocating pages of a certain type. However, it is quite obvious
that EFI_LOADER_CODE is more likely to permit execution than
EFI_LOADER_DATA, which becomes relevant once we permit booting the
kernel proper with the firmware's 1:1 mapping still active.

Ostensibly, recent systems such as the Surface Pro X grant executable
permissions to EFI_LOADER_CODE regions but not EFI_LOADER_DATA regions.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index 21b01d6c77ba..e85916ed5311 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -880,7 +880,8 @@ void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size,
 efi_status_t efi_get_random_bytes(unsigned long size, u8 *out);
 
 efi_status_t efi_random_alloc(unsigned long size, unsigned long align,
-			      unsigned long *addr, unsigned long random_seed);
+			      unsigned long *addr, unsigned long random_seed,
+			      int memory_type);
 
 efi_status_t check_platform_features(void);
 
@@ -905,7 +906,8 @@ efi_status_t efi_allocate_pages(unsigned long size, unsigned long *addr,
 				unsigned long max);
 
 efi_status_t efi_allocate_pages_aligned(unsigned long size, unsigned long *addr,
-					unsigned long max, unsigned long align);
+					unsigned long max, unsigned long align,
+					int memory_type);
 
 efi_status_t efi_low_alloc_above(unsigned long size, unsigned long align,
 				 unsigned long *addr, unsigned long min);