[PATCH 2/3] dtc: backport fix for build with glibc-2.43

martin.jansa
2026-03-05T18:03:44Z

glibc-2.43 isn't used in OE builds yet, but this fixes dtc-native:
https://errors.yoctoproject.org/Errors/Details/903983/

../sources/dtc-1.7.2/libfdt/fdt_overlay.c: In function ‘overlay_fixup_phandle’:
../sources/dtc-1.7.2/libfdt/fdt_overlay.c:424:21: error: assignment discards ‘const’ qualifier from pointer target type [-Werror=discarded-qualifiers]
424 | sep = memchr(fixup_str, ':', fixup_len);
| ^
../sources/dtc-1.7.2/libfdt/fdt_overlay.c:434:21: error: assignment discards ‘const’ qualifier from pointer target type [-Werror=discarded-qualifiers]
434 | sep = memchr(name, ':', fixup_len);
| ^
cc1: all warnings being treated as errors

Signed-off-by: Martin Jansa <martin.jansa@gmail.com>
---
.../0001-Fix-discarded-const-qualifiers.patch | 83 +++++++++++++++++++
meta/recipes-kernel/dtc/dtc_1.7.2.bb | 1 +
2 files changed, 84 insertions(+)
create mode 100644 meta/recipes-kernel/dtc/dtc/0001-Fix-discarded-const-qualifiers.patch

diff --git a/meta/recipes-kernel/dtc/dtc/0001-Fix-discarded-const-qualifiers.patch b/meta/recipes-kernel/dtc/dtc/0001-Fix-discarded-const-qualifiers.patch
new file mode 100644
index 0000000000..053a94f0bf
--- /dev/null
+++ b/meta/recipes-kernel/dtc/dtc/0001-Fix-discarded-const-qualifiers.patch
@@ -0,0 +1,83 @@
+From c58beee7bec0774f12202511c97beb741ff2b534 Mon Sep 17 00:00:00 2001
+From: Stephen Gallagher <sgallagh@redhat.com>
+Date: Tue, 6 Jan 2026 14:19:30 -0500
+Subject: [PATCH] Fix discarded const qualifiers
+
+It's unsafe to implicitly discard the const qualifier on a pointer. In
+overlay_fixup_phandle(), this was probably just an oversight, and making
+the "sep" variable a const char * is sufficient to fix it.
+
+In create_node(), however, the "p" variable is directly modifying the
+buffer pointed to by "const char* node_name". To fix this, we need to
+actually make a duplicate of the buffer and operate on that instead.
+
+This introduces a malloc()/free() and an unbounded strdup() into the
+operation, but fdtput isn't a long-running service and the node_name
+argument comes directly from argv, so this shouldn't introduce a
+significant performance impact.
+
+Signed-off-by: Stephen Gallagher <sgallagh@redhat.com>
+Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
+Signed-off-by: Martin Jansa <martin.jansa@gmail.com>
+Upstream-Status: Backport [https://git.kernel.org/pub/scm/utils/dtc/dtc.git/commit/libfdt/fdt_overlay.c?h=main&id=9a1c801a1a3c102bf95c5339c9e985b26b823a21]
+---
+ fdtput.c | 8 +++++---
+ libfdt/fdt_overlay.c | 3 ++-
+ meson.build | 1 +
+ 3 files changed, 8 insertions(+), 4 deletions(-)
+
+diff --git a/fdtput.c b/fdtput.c
+index c2fecf4..8deec7e 100644
+--- a/fdtput.c
++++ b/fdtput.c
+@@ -230,19 +230,21 @@ static int create_paths(char **blob, const char *in_path)
+ static int create_node(char **blob, const char *node_name)
+ {
+ int node = 0;
+- char *p;
++ const char *p;
++ char *path = NULL;
+
+ p = strrchr(node_name, '/');
+ if (!p) {
+ report_error(node_name, -1, -FDT_ERR_BADPATH);
+ return -1;
+ }
+- *p = '\0';
+
+ *blob = realloc_node(*blob, p + 1);
+
+ if (p > node_name) {
+- node = fdt_path_offset(*blob, node_name);
++ path = xstrndup(node_name, (size_t)(p - node_name));
++ node = fdt_path_offset(*blob, path);
++ free(path);
+ if (node < 0) {
+ report_error(node_name, -1, node);
+ return -1;
+diff --git a/libfdt/fdt_overlay.c b/libfdt/fdt_overlay.c
+index 28b667f..5f8aa62 100644
+--- a/libfdt/fdt_overlay.c
++++ b/libfdt/fdt_overlay.c
+@@ -409,7 +409,8 @@ static int overlay_fixup_phandle(void *fdt, void *fdto, int symbols_off,
+ const char *fixup_str = value;
+ uint32_t path_len, name_len;
+ uint32_t fixup_len;
+- char *sep, *endptr;
++ const char *sep;
++ char *endptr;
+ int poffset, ret;
+
+ fixup_end = memchr(value, '\0', len);
+diff --git a/meson.build b/meson.build
+index 310699f..2966b06 100644
+--- a/meson.build
++++ b/meson.build
+@@ -18,6 +18,7 @@ add_project_arguments(
+ '-Wshadow',
+ '-Wsuggest-attribute=format',
+ '-Wwrite-strings',
++ '-Wdiscarded-qualifiers',
+ ]),
+ language: 'c'
+ )
diff --git a/meta/recipes-kernel/dtc/dtc_1.7.2.bb b/meta/recipes-kernel/dtc/dtc_1.7.2.bb
index 92e83a9404..b8b79542c5 100644
--- a/meta/recipes-kernel/dtc/dtc_1.7.2.bb
+++ b/meta/recipes-kernel/dtc/dtc_1.7.2.bb
@@ -10,6 +10,7 @@ LIC_FILES_CHKSUM = "file://GPL;md5=b234ee4d69f5fce4486a80fdaf4a4263 \

SRC_URI = " \
git://git.kernel.org/pub/scm/utils/dtc/dtc.git;branch=main;protocol=https \
+ file://0001-Fix-discarded-const-qualifiers.patch \
"
SRCREV = "2d10aa2afe35527728db30b35ec491ecb6959e5c"