[coreboot-gerrit] Change in coreboot[master]: device: Add checks for NULL in device_const.c functions

[Furquan Shaikh (Code Review)]

Furquan Shaikh has submitted this change. ( https://review.coreboot.org/c/coreboot/+/40475 )

Change subject: device: Add checks for NULL in device_const.c functions
......................................................................

device: Add checks for NULL in device_const.c functions

This change checks to ensure that device/path passed into any of the
functions in device_const.c is not NULL. Since NULL is not expected to
be passed into these functions, this change adds a die() call in case
the assumption is broken.

Change-Id: I1ad8d2bcb9d0546104c5e065af1eeff331cdf96d
Signed-off-by: Furquan Shaikh 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/40475
Tested-by: build bot (Jenkins) 
Reviewed-by: Aaron Durbin 
Reviewed-by: Angel Pons 
---
M src/device/device_const.c
1 file changed, 15 insertions(+), 0 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Aaron Durbin: Looks good to me, approved
  Angel Pons: Looks good to me, approved

diff --git a/src/device/device_const.c b/src/device/device_const.c
index c59c5e9..2e0ccc4 100644
--- a/src/device/device_const.c
+++ b/src/device/device_const.c
@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 /* This file is part of the coreboot project. */

+#include <assert.h>
 #include <console/console.h>
 #include <device/device.h>
 #include <device/path.h>
@@ -86,6 +87,13 @@
 {
    int equal = 0;

+	if (!path1 || !path2) {
+		assert(path1);
+		assert(path2);
+		/* Return 0 in case assert is considered non-fatal. */
+		return 0;
+	}
+
    if (path1->type != path2->type)
    	return 0;

@@ -156,6 +164,13 @@
    const struct bus *parent, const struct device_path *path)
 {
    DEVTREE_CONST struct device *child;
+
+	if (!parent) {
+		assert(0);
+		/* Return NULL in case asserts are considered non-fatal. */
+		return NULL;
+	}
+
    for (child = parent->children; child; child = child->sibling) {
    	if (path_eq(path, &child->path))
    		break;