kexec/dt-ops.c: Fix adding '/chosen' node for cases where it is not available in dtb passed via --dtb option

While calling 'kexec -l', in case we are passed a .dtb using --dtb
option which doesn't contain a '/chosen' node, we try to create the
'/chosen' node and add bootargs to this node.

Currently the 'dt-ops.c' code is buggy as it passes '-FDT_ERR_NOTFOUND'
to 'fdt_add_subnode()', which leads to the following error:

  # kexec -d --load Image --append 'debug' --dtb rk3399-sapphire.dtb

  <..snip..>
  dtb_set_property: fdt_add_subnode failed: FDT_ERR_NOTFOUND
  kexec: Set device tree bootargs failed.
  get_cells_size: #address-cells:2 #size-cells:2
  cells_size_fitted: 0-0
  cells_size_fitted: 0-0
  setup_2nd_dtb: no kaslr-seed found

This patch passes the correct nodeoffset value to 'fdt_add_subnode()',
which fixes this issue:

  # kexec -d -l Image --append 'debug' --dtb rk3399-sapphire.dtb

  <..snip..>
  get_cells_size: #address-cells:2 #size-cells:2
  cells_size_fitted: 0-0
  cells_size_fitted: 0-0
  setup_2nd_dtb: no kaslr-seed found

Reported-by: Vicente Bergas <vicencb@gmail.com>
Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com>
Signed-off-by: Simon Horman <horms@verge.net.au>

1 files changed, 3 insertions, 2 deletions

diff --git a/kexec/dt-ops.c b/kexec/dt-ops.c
index f15174c3..bdc16dc8 100644
--- a/kexec/dt-ops.c
+++ b/kexec/dt-ops.c
@@ -80,15 +80,16 @@ int dtb_set_property(char **dtb, off_t *dtb_size, const char *node,
 	}
 
 	nodeoffset = fdt_path_offset(new_dtb, node);
-	
+
 	if (nodeoffset == -FDT_ERR_NOTFOUND) {
-		result = fdt_add_subnode(new_dtb, nodeoffset, node);
+		result = fdt_add_subnode(new_dtb, 0, node);
 
 		if (result < 0) {
 			dbgprintf("%s: fdt_add_subnode failed: %s\n", __func__,
 				fdt_strerror(result));
 			goto on_error;
 		}
+		nodeoffset = result;
 	} else if (nodeoffset < 0) {
 		dbgprintf("%s: fdt_path_offset failed: %s\n", __func__,
 			fdt_strerror(nodeoffset));