From: Herve Codina <herve.codina@bootlin.com>
To: David Gibson <david@gibson.dropbear.id.au>,
Rob Herring <robh@kernel.org>,
Krzysztof Kozlowski <krzk@kernel.org>,
Conor Dooley <conor+dt@kernel.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
David Lechner <dlechner@baylibre.com>,
Ayush Singh <ayush@beagleboard.org>,
Geert Uytterhoeven <geert@linux-m68k.org>,
devicetree-compiler@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, devicetree-spec@vger.kernel.org,
Hui Pu <hui.pu@gehealthcare.com>,
Ian Ray <ian.ray@gehealthcare.com>,
Luca Ceresoli <luca.ceresoli@bootlin.com>,
Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
Herve Codina <herve.codina@bootlin.com>
Subject: [PATCH v3 03/15] tests: Don't assume the root node is available at offset 0
Date: Wed, 26 Aug 2026 10:31:34 +0200 [thread overview]
Message-ID: <20260826083146.304291-4-herve.codina@bootlin.com> (raw)
In-Reply-To: <20260826083146.304291-1-herve.codina@bootlin.com>
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@bootlin.com>
---
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
next prev parent reply other threads:[~2026-08-26 8:32 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-26 8:31 [PATCH v3 00/15] Add support for structured tags and v18 dtb version Herve Codina
2026-08-26 8:31 ` [PATCH v3 01/15] fdtget: Use libfdt iterators instead of open coded loops Herve Codina
2026-08-26 8:31 ` [PATCH v3 02/15] libfdt: Don't assume the root node is available at offset 0 Herve Codina
2026-08-26 8:31 ` Herve Codina [this message]
2026-08-26 8:31 ` [PATCH v3 04/15] tests/nopulate: Add a FDT_NOP before the root node Herve Codina
2026-08-26 8:31 ` [PATCH v3 05/15] tests: treegen: Introduce emit_fdt_header_vers() Herve Codina
2026-08-26 8:31 ` [PATCH v3 06/15] Introduce structured tag value definition Herve Codina
2026-08-26 8:31 ` [PATCH v3 07/15] fdtdump: Handle unknown tags Herve Codina
2026-08-26 8:31 ` [PATCH v3 08/15] flattree: " Herve Codina
2026-08-26 8:31 ` [PATCH v3 09/15] libfdt: Handle unknown tags in fdt_next_tag() Herve Codina
2026-08-26 8:31 ` [PATCH v3 10/15] libfdt: Introduce fdt_ptr_offset_() Herve Codina
2026-08-26 8:31 ` [PATCH v3 11/15] libfdt: Introduce fdt_getprop_by_offset_w() Herve Codina
2026-08-26 8:31 ` [PATCH v3 12/15] libfdt: Introduce fdt_getprop_offset_namelen() Herve Codina
2026-08-26 8:31 ` [PATCH v3 13/15] tests: Add wip_func utility Herve Codina
2026-08-26 8:31 ` [PATCH v3 14/15] libfdt: Handle unknown tags on dtb modifications Herve Codina
2026-08-26 8:31 ` [PATCH v3 15/15] Introduce v18 dtb version Herve Codina
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