efi_loader: allow concatenation with contained end node

Allow appending a device-path to a device-path that contains an end node
as separator. We need this feature for creating boot options specifying
kernel, initrd, and dtb.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

5 files changed, 17 insertions, 11 deletions

diff --git a/lib/efi_loader/efi_bootbin.c b/lib/efi_loader/efi_bootbin.c
index b7910f78fb6..a87006b3c0e 100644
--- a/lib/efi_loader/efi_bootbin.c
+++ b/lib/efi_loader/efi_bootbin.c
@@ -150,7 +150,7 @@ efi_status_t efi_run_image(void *source_buffer, efi_uintn_t source_size)
 		msg_path = file_path;
 	} else {
 		file_path = efi_dp_concat(bootefi_device_path,
-					  bootefi_image_path, false);
+					  bootefi_image_path, 0);
 		msg_path = bootefi_image_path;
 		log_debug("Loaded from disk\n");
 	}
diff --git a/lib/efi_loader/efi_bootmgr.c b/lib/efi_loader/efi_bootmgr.c
index 7da3139f917..b0bf21cf841 100644
--- a/lib/efi_loader/efi_bootmgr.c
+++ b/lib/efi_loader/efi_bootmgr.c
@@ -130,7 +130,7 @@ static efi_status_t try_load_from_file_path(efi_handle_t *fs_handles,
 		if (!dp)
 			continue;
 
-		dp = efi_dp_concat(dp, fp, false);
+		dp = efi_dp_concat(dp, fp, 0);
 		if (!dp)
 			continue;
 
diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
index 1951291747c..630c5f52c4f 100644
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -1816,7 +1816,7 @@ efi_status_t efi_setup_loaded_image(struct efi_device_path *device_path,
 	if (device_path) {
 		info->device_handle = efi_dp_find_obj(device_path, NULL, NULL);
 
-		dp = efi_dp_concat(device_path, file_path, false);
+		dp = efi_dp_concat(device_path, file_path, 0);
 		if (!dp) {
 			ret = EFI_OUT_OF_RESOURCES;
 			goto failure;
diff --git a/lib/efi_loader/efi_device_path.c b/lib/efi_loader/efi_device_path.c
index aec224d8466..18be8a1b4f1 100644
--- a/lib/efi_loader/efi_device_path.c
+++ b/lib/efi_loader/efi_device_path.c
@@ -276,10 +276,11 @@ struct efi_device_path *efi_dp_dup(const struct efi_device_path *dp)
  *
  * @dp1:	    First device path
  * @dp2:	    Second device path
- * @split_end_node: If true the two device paths will be concatenated and
- *                  separated by an end node (DEVICE_PATH_SUB_TYPE_END).
- *		    If false the second device path will be concatenated to the
- *		    first one as-is.
+ * @split_end_node:
+ * * 0 to concatenate
+ * * 1 to concatenate with end node added as separator
+ * * size of dp1 excluding last end node to concatenate with end node as
+ *   separator in case dp1 contains an end node
  *
  * Return:
  * concatenated device path or NULL. Caller must free the returned value
@@ -287,7 +288,7 @@ struct efi_device_path *efi_dp_dup(const struct efi_device_path *dp)
 struct
 efi_device_path *efi_dp_concat(const struct efi_device_path *dp1,
 			       const struct efi_device_path *dp2,
-			       bool split_end_node)
+			       size_t split_end_node)
 {
 	struct efi_device_path *ret;
 	size_t end_size;
@@ -301,10 +302,15 @@ efi_device_path *efi_dp_concat(const struct efi_device_path *dp1,
 		ret = efi_dp_dup(dp1);
 	} else {
 		/* both dp1 and dp2 are non-null */
-		unsigned sz1 = efi_dp_size(dp1);
-		unsigned sz2 = efi_dp_size(dp2);
+		size_t sz1;
+		size_t sz2 = efi_dp_size(dp2);
 		void *p;
 
+		if (split_end_node < sizeof(struct efi_device_path))
+			sz1 = efi_dp_size(dp1);
+		else
+			sz1 = split_end_node;
+
 		if (split_end_node)
 			end_size = 2 * sizeof(END);
 		else
diff --git a/lib/efi_loader/efi_device_path_utilities.c b/lib/efi_loader/efi_device_path_utilities.c
index c95dbfa9b5f..ac250bbfcc9 100644
--- a/lib/efi_loader/efi_device_path_utilities.c
+++ b/lib/efi_loader/efi_device_path_utilities.c
@@ -76,7 +76,7 @@ static struct efi_device_path * EFIAPI append_device_path(
 	const struct efi_device_path *src2)
 {
 	EFI_ENTRY("%pD, %pD", src1, src2);
-	return EFI_EXIT(efi_dp_concat(src1, src2, false));
+	return EFI_EXIT(efi_dp_concat(src1, src2, 0));
 }
 
 /*