efi/libstub: Avoid protocol wrapper for file I/O routines

The EFI file I/O routines built on top of the file I/O firmware
services are incompatible with mixed mode, so there is no need
to obfuscate them by using protocol wrappers whose only purpose
is to hide the mixed mode handling. So let's switch to plain
indirect calls instead.

This also means we can drop the mixed_mode aliases from the various
types involved.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Borislav Petkov <bp@alien8.de>
Cc: James Morse <james.morse@arm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20191224151025.32482-15-ardb@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 7 insertions, 10 deletions

diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c
index f91f4fdbe553..9bb74ad4b7fe 100644
--- a/drivers/firmware/efi/libstub/efi-stub-helper.c
+++ b/drivers/firmware/efi/libstub/efi-stub-helper.c
@@ -370,8 +370,7 @@ static efi_status_t efi_file_size(efi_system_table_t *sys_table_arg, void *__fh,
 	efi_guid_t info_guid = EFI_FILE_INFO_ID;
 	unsigned long info_sz;
 
-	status = efi_call_proto(efi_file_handle, open, fh, &h, filename_16,
-				EFI_FILE_MODE_READ, (u64)0);
+	status = fh->open(fh, &h, filename_16, EFI_FILE_MODE_READ, 0);
 	if (status != EFI_SUCCESS) {
 		efi_printk(sys_table_arg, "Failed to open file: ");
 		efi_char16_printk(sys_table_arg, filename_16);
@@ -382,8 +381,7 @@ static efi_status_t efi_file_size(efi_system_table_t *sys_table_arg, void *__fh,
 	*handle = h;
 
 	info_sz = 0;
-	status = efi_call_proto(efi_file_handle, get_info, h, &info_guid,
-				&info_sz, NULL);
+	status = h->get_info(h, &info_guid, &info_sz, NULL);
 	if (status != EFI_BUFFER_TOO_SMALL) {
 		efi_printk(sys_table_arg, "Failed to get file info size\n");
 		return status;
@@ -397,8 +395,7 @@ grow:
 		return status;
 	}
 
-	status = efi_call_proto(efi_file_handle, get_info, h, &info_guid,
-				&info_sz, info);
+	status = h->get_info(h, &info_guid, &info_sz, info);
 	if (status == EFI_BUFFER_TOO_SMALL) {
 		efi_call_early(free_pool, info);
 		goto grow;
@@ -416,12 +413,12 @@ grow:
 static efi_status_t efi_file_read(efi_file_handle_t *handle,
 				  unsigned long *size, void *addr)
 {
-	return efi_call_proto(efi_file_handle, read, handle, size, addr);
+	return handle->read(handle, size, addr);
 }
 
 static efi_status_t efi_file_close(efi_file_handle_t *handle)
 {
-	return efi_call_proto(efi_file_handle, close, handle);
+	return handle->close(handle);
 }
 
 static efi_status_t efi_open_volume(efi_system_table_t *sys_table_arg,
@@ -432,7 +429,7 @@ static efi_status_t efi_open_volume(efi_system_table_t *sys_table_arg,
 	efi_file_handle_t *fh;
 	efi_guid_t fs_proto = EFI_FILE_SYSTEM_GUID;
 	efi_status_t status;
-	void *handle = efi_table_attr(efi_loaded_image, device_handle, image);
+	efi_handle_t handle = image->device_handle;
 
 	status = efi_call_early(handle_protocol, handle,
 				&fs_proto, (void **)&io);
@@ -441,7 +438,7 @@ static efi_status_t efi_open_volume(efi_system_table_t *sys_table_arg,
 		return status;
 	}
 
-	status = efi_call_proto(efi_file_io_interface, open_volume, io, &fh);
+	status = io->open_volume(io, &fh);
 	if (status != EFI_SUCCESS)
 		efi_printk(sys_table_arg, "Failed to open volume\n");
 	else