[PATCH v3 03/15] tests: Don't assume the root node is available at offset 0
From: Herve Codina
Date: Wed Aug 26 2026 - 04:36:31 EST
Several tests uses offset 0 as the offset of the root node. Either to
check the offset returned by tested functions or to directly manipulate
the root node retrieved using fdt_offset_ptr(fdt, 0, ...).
The root node is not always at offset 0. Indeed, a FDT_NOP tag can be
present at offset 0. fdt_root_offset() returns the offset of the root
node taking care of possible FDT_NOP tag.
Use fdt_root_offset() to get the offset of the root node and use this
value whenever the offset of the root node is expected.
Signed-off-by: Herve Codina <herve.codina@xxxxxxxxxxx>
---
tests/node_offset_by_compatible.c | 4 +++-
tests/node_offset_by_prop_value.c | 11 +++++++----
tests/path_offset.c | 13 +++++++++----
tests/root_node.c | 6 +++++-
4 files changed, 24 insertions(+), 10 deletions(-)
diff --git a/tests/node_offset_by_compatible.c b/tests/node_offset_by_compatible.c
index a9e67835..1278a562 100644
--- a/tests/node_offset_by_compatible.c
+++ b/tests/node_offset_by_compatible.c
@@ -39,12 +39,14 @@ static void check_search(void *fdt, const char *compat, ...)
int main(int argc, char *argv[])
{
void *fdt;
+ int root_offset;
int subnode1_offset, subnode2_offset;
int subsubnode1_offset, subsubnode2_offset;
test_init(argc, argv);
fdt = load_blob_arg(argc, argv);
+ root_offset = fdt_root_offset(fdt);
subnode1_offset = fdt_path_offset(fdt, "/subnode@1");
subnode2_offset = fdt_path_offset(fdt, "/subnode@2");
subsubnode1_offset = fdt_path_offset(fdt, "/subnode@1/subsubnode");
@@ -54,7 +56,7 @@ int main(int argc, char *argv[])
|| (subsubnode1_offset < 0) || (subsubnode2_offset < 0))
FAIL("Can't find required nodes");
- check_search(fdt, "test_tree1", 0, -FDT_ERR_NOTFOUND);
+ check_search(fdt, "test_tree1", root_offset, -FDT_ERR_NOTFOUND);
check_search(fdt, "subnode1", subnode1_offset, -FDT_ERR_NOTFOUND);
check_search(fdt, "subsubnode1", subsubnode1_offset, -FDT_ERR_NOTFOUND);
check_search(fdt, "subsubnode2", subsubnode2_offset, -FDT_ERR_NOTFOUND);
diff --git a/tests/node_offset_by_prop_value.c b/tests/node_offset_by_prop_value.c
index 48ab1d93..329409b9 100644
--- a/tests/node_offset_by_prop_value.c
+++ b/tests/node_offset_by_prop_value.c
@@ -64,12 +64,14 @@ static void check_search_str(void *fdt, const char *propname,
int main(int argc, char *argv[])
{
void *fdt;
+ int root_offset;
int subnode1_offset, subnode2_offset;
int subsubnode1_offset, subsubnode2_offset;
test_init(argc, argv);
fdt = load_blob_arg(argc, argv);
+ root_offset = fdt_root_offset(fdt);
subnode1_offset = fdt_path_offset(fdt, "/subnode@1");
subnode2_offset = fdt_path_offset(fdt, "/subnode@2");
subsubnode1_offset = fdt_path_offset(fdt, "/subnode@1/subsubnode");
@@ -79,19 +81,20 @@ int main(int argc, char *argv[])
|| (subsubnode1_offset < 0) || (subsubnode2_offset < 0))
FAIL("Can't find required nodes");
- check_search_cell(fdt, "prop-int", TEST_VALUE_1, 0, subnode1_offset,
- subsubnode1_offset, -FDT_ERR_NOTFOUND);
+ check_search_cell(fdt, "prop-int", TEST_VALUE_1, root_offset,
+ subnode1_offset, subsubnode1_offset, -FDT_ERR_NOTFOUND);
check_search_cell(fdt, "prop-int", TEST_VALUE_2, subnode2_offset,
subsubnode2_offset, -FDT_ERR_NOTFOUND);
- check_search_str(fdt, "prop-str", TEST_STRING_1, 0, -FDT_ERR_NOTFOUND);
+ check_search_str(fdt, "prop-str", TEST_STRING_1, root_offset,
+ -FDT_ERR_NOTFOUND);
check_search_str(fdt, "prop-str", "no such string", -FDT_ERR_NOTFOUND);
check_search_cell(fdt, "prop-int", TEST_VALUE_1+1, -FDT_ERR_NOTFOUND);
- check_search(fdt, "no-such-prop", NULL, 0, -FDT_ERR_NOTFOUND);
+ check_search(fdt, "no-such-prop", NULL, root_offset, -FDT_ERR_NOTFOUND);
PASS();
}
diff --git a/tests/path_offset.c b/tests/path_offset.c
index ad8db833..d4f6553b 100644
--- a/tests/path_offset.c
+++ b/tests/path_offset.c
@@ -84,11 +84,16 @@ int main(int argc, char *argv[])
void *fdt;
int subnode1_offset, subnode2_offset;
int subsubnode1_offset, subsubnode2_offset, subsubnode2_offset2;
+ int root_offset;
test_init(argc, argv);
fdt = load_blob_arg(argc, argv);
- check_path_offset(fdt, "/", 0);
+ root_offset = fdt_root_offset(fdt);
+ if (root_offset < 0)
+ FAIL("fdt_root_offset()) failed: %s", fdt_strerror(root_offset));
+
+ check_path_offset(fdt, "/", root_offset);
subnode1_offset = check_subnode(fdt, 0, "subnode@1");
subnode2_offset = check_subnode(fdt, 0, "subnode@2");
@@ -106,8 +111,8 @@ int main(int argc, char *argv[])
/* Test paths with extraneous separators */
check_path_offset(fdt, "", -FDT_ERR_BADPATH);
- check_path_offset(fdt, "//", 0);
- check_path_offset(fdt, "///", 0);
+ check_path_offset(fdt, "//", root_offset);
+ check_path_offset(fdt, "///", root_offset);
check_path_offset(fdt, "//subnode@1", subnode1_offset);
check_path_offset(fdt, "/subnode@1/", subnode1_offset);
check_path_offset(fdt, "//subnode@1///", subnode1_offset);
@@ -116,7 +121,7 @@ int main(int argc, char *argv[])
/* Test fdt_path_offset_namelen() */
check_path_offset_namelen(fdt, "/subnode@1", -1, -FDT_ERR_BADPATH);
check_path_offset_namelen(fdt, "/subnode@1", 0, -FDT_ERR_BADPATH);
- check_path_offset_namelen(fdt, "/subnode@1", 1, 0);
+ check_path_offset_namelen(fdt, "/subnode@1", 1, root_offset);
check_path_offset_namelen(fdt, "/subnode@1/subsubnode", 10, subnode1_offset);
check_path_offset_namelen(fdt, "/subnode@1/subsubnode", 11, subnode1_offset);
check_path_offset_namelen(fdt, "/subnode@2TRAILINGGARBAGE", 10, subnode2_offset);
diff --git a/tests/root_node.c b/tests/root_node.c
index 37e6f059..30903f2b 100644
--- a/tests/root_node.c
+++ b/tests/root_node.c
@@ -19,12 +19,16 @@ int main(int argc, char *argv[])
{
void *fdt;
const struct fdt_node_header *nh;
+ int root_offset;
test_init(argc, argv);
fdt = load_blob_arg(argc, argv);
- nh = fdt_offset_ptr(fdt, 0, sizeof(*nh));
+ root_offset = fdt_root_offset(fdt);
+ if (root_offset < 0)
+ FAIL("fdt_root_offset() returns %d", root_offset);
+ nh = fdt_offset_ptr(fdt, root_offset, sizeof(*nh));
if (! nh)
FAIL("NULL retrieving root node");
--
2.55.0