2 files changed, 81 insertions, 12 deletions

diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index e85916ed5311..1fde9cbe6899 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -179,6 +179,21 @@ union efi_device_path_to_text_protocol {
 
 typedef union efi_device_path_to_text_protocol efi_device_path_to_text_protocol_t;
 
+union efi_device_path_from_text_protocol {
+	struct {
+		efi_device_path_protocol_t *
+			(__efiapi *convert_text_to_device_node)(const efi_char16_t *);
+		efi_device_path_protocol_t *
+			(__efiapi *convert_text_to_device_path)(const efi_char16_t *);
+	};
+	struct {
+		u32 convert_text_to_device_node;
+		u32 convert_text_to_device_path;
+	} mixed_mode;
+};
+
+typedef union efi_device_path_from_text_protocol efi_device_path_from_text_protocol_t;
+
 typedef void *efi_event_t;
 /* Note that notifications won't work in mixed mode */
 typedef void (__efiapi *efi_event_notify_t)(efi_event_t, void *);
diff --git a/drivers/firmware/efi/libstub/file.c b/drivers/firmware/efi/libstub/file.c
index 246ccc5b015d..20d3530ca9c5 100644
--- a/drivers/firmware/efi/libstub/file.c
+++ b/drivers/firmware/efi/libstub/file.c
@@ -43,6 +43,13 @@ static efi_status_t efi_open_file(efi_file_protocol_t *volume,
 	efi_file_protocol_t *fh;
 	unsigned long info_sz;
 	efi_status_t status;
+	efi_char16_t *c;
+
+	/* Replace UNIX dir separators with EFI standard ones */
+	for (c = fi->filename; *c != L'\0'; c++) {
+		if (*c == L'/')
+			*c = L'\\';
+	}
 
 	status = volume->open(volume, &fh, fi->filename, EFI_FILE_MODE_READ, 0);
 	if (status != EFI_SUCCESS) {
@@ -111,16 +118,61 @@ static int find_file_option(const efi_char16_t *cmdline, int cmdline_len,
 
 		if (c == L'\0' || c == L'\n' || c == L' ')
 			break;
-		else if (c == L'/')
-			/* Replace UNIX dir separators with EFI standard ones */
-			*result++ = L'\\';
-		else
-			*result++ = c;
+		*result++ = c;
 	}
 	*result = L'\0';
 	return i;
 }
 
+static efi_status_t efi_open_device_path(efi_file_protocol_t **volume,
+					 struct finfo *fi)
+{
+	efi_guid_t text_to_dp_guid = EFI_DEVICE_PATH_FROM_TEXT_PROTOCOL_GUID;
+	static efi_device_path_from_text_protocol_t *text_to_dp = NULL;
+	efi_guid_t fs_proto = EFI_FILE_SYSTEM_GUID;
+	efi_device_path_protocol_t *initrd_dp;
+	efi_simple_file_system_protocol_t *io;
+	struct efi_file_path_dev_path *fpath;
+	efi_handle_t handle;
+	efi_status_t status;
+
+	/* See if the text to device path protocol exists */
+	if (!text_to_dp &&
+	    efi_bs_call(locate_protocol, &text_to_dp_guid, NULL,
+			(void **)&text_to_dp) != EFI_SUCCESS)
+		return EFI_UNSUPPORTED;
+
+
+	/* Convert the filename wide string into a device path */
+	initrd_dp = text_to_dp->convert_text_to_device_path(fi->filename);
+
+	/* Check whether the device path in question implements simple FS */
+	if ((efi_bs_call(locate_device_path, &fs_proto, &initrd_dp, &handle) ?:
+	     efi_bs_call(handle_protocol, handle, &fs_proto, (void **)&io))
+	    != EFI_SUCCESS)
+		return EFI_NOT_FOUND;
+
+	/* Check whether the remaining device path is a file device path */
+	if (initrd_dp->type != EFI_DEV_MEDIA ||
+	    initrd_dp->sub_type != EFI_DEV_MEDIA_FILE) {
+		efi_warn("Unexpected device path node type: (%x, %x)\n",
+			 initrd_dp->type, initrd_dp->sub_type);
+		return EFI_LOAD_ERROR;
+	}
+
+	/* Copy the remaining file path into the fi structure */
+	fpath = (struct efi_file_path_dev_path *)initrd_dp;
+	memcpy(fi->filename, fpath->filename,
+	       min(sizeof(fi->filename),
+		   fpath->header.length - sizeof(fpath->header)));
+
+	status = io->open_volume(io, volume);
+	if (status != EFI_SUCCESS)
+		efi_err("Failed to open volume\n");
+
+	return status;
+}
+
 /*
  * Check the cmdline for a LILO-style file= arguments.
  *
@@ -170,11 +222,13 @@ efi_status_t handle_cmdline_files(efi_loaded_image_t *image,
 		cmdline += offset;
 		cmdline_len -= offset;
 
-		if (!volume) {
+		status = efi_open_device_path(&volume, &fi);
+		if (status == EFI_UNSUPPORTED || status == EFI_NOT_FOUND)
+			/* try the volume that holds the kernel itself */
 			status = efi_open_volume(image, &volume);
-			if (status != EFI_SUCCESS)
-				return status;
-		}
+
+		if (status != EFI_SUCCESS)
+			goto err_free_alloc;
 
 		status = efi_open_file(volume, &fi, &file, &size);
 		if (status != EFI_SUCCESS)
@@ -231,14 +285,12 @@ efi_status_t handle_cmdline_files(efi_loaded_image_t *image,
 			size -= chunksize;
 		}
 		file->close(file);
+		volume->close(volume);
 	} while (offset > 0);
 
 	*load_addr = alloc_addr;
 	*load_size = alloc_size;
 
-	if (volume)
-		volume->close(volume);
-
 	if (*load_size == 0)
 		return EFI_NOT_READY;
 	return EFI_SUCCESS;
@@ -248,6 +300,8 @@ err_close_file:
 
 err_close_volume:
 	volume->close(volume);
+
+err_free_alloc:
 	efi_free(alloc_size, alloc_addr);
 	return status;
 }