libfdt: fdt_rw: Introduce fdt_downgrade_version()

Current code perform a version downgrade at one place only, the end of fdt_rw_probe_(). In order to offer a finer grain and choose to downgrade or not depending on the exact writes done, introduce fdt_downgrade_version() to perform the downgrade operation. The modification doesn't introduce any functional changes. Signed-off-by: Herve Codina <herve.codina@bootlin.com> Message-ID: <20260210173349.636766-5-herve.codina@bootlin.com> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
fdtdump: Return an error code on wrong tag value
2026-05-12 11:43:04 -04:00 · 2026-02-24 17:00:38 +11:00 · 2026-02-24 16:52:47 +11:00
2 changed files with 8 additions and 4 deletions
--- a/fdtdump.c
+++ b/fdtdump.c
@ -146,8 +146,7 @@ static void dump_blob(void *blob, bool debug)
 			continue;
 		}

-		fprintf(stderr, "%*s ** Unknown tag 0x%08"PRIx32"\n", depth * shift, "", tag);
-		break;
+		die("** Unknown tag 0x%08"PRIx32"\n", tag);
 	}
 }

--- a/libfdt/fdt_rw.c
+++ b/libfdt/fdt_rw.c
@ -22,6 +22,12 @@ static int fdt_blocks_misordered_(const void *fdt,
 		    (fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt)));
 }

+static void fdt_downgrade_version(void *fdt)
+{
+	if (!can_assume(LATEST) && fdt_version(fdt) > FDT_LAST_SUPPORTED_VERSION)
+		fdt_set_version(fdt, FDT_LAST_SUPPORTED_VERSION);
+}
+
 static int fdt_rw_probe_(void *fdt)
 {
 	if (can_assume(VALID_DTB))
@ -33,9 +39,8 @@ static int fdt_rw_probe_(void *fdt)
 	if (fdt_blocks_misordered_(fdt, sizeof(struct fdt_reserve_entry),
 				   fdt_size_dt_struct(fdt)))
 		return -FDT_ERR_BADLAYOUT;
-	if (!can_assume(LATEST) && fdt_version(fdt) > 17)
-		fdt_set_version(fdt, 17);

+	fdt_downgrade_version(fdt);
 	return 0;
 }
Author	SHA1	Message	Date
Herve Codina	5976c4a660	libfdt: fdt_rw: Introduce fdt_downgrade_version() Some checks failed Build test / build-make (alpine) (push) Has been cancelled Details Build test / build-make (archlinux) (push) Has been cancelled Details Build test / build-make (fedora) (push) Has been cancelled Details Build test / build-make (ubuntu) (push) Has been cancelled Details Build test / build-meson (alpine) (push) Has been cancelled Details Build test / build-meson (archlinux) (push) Has been cancelled Details Build test / build-meson (fedora) (push) Has been cancelled Details Build test / build-meson (ubuntu) (push) Has been cancelled Details Build test / clang64 (push) Has been cancelled Details Build test / mingw32 (push) Has been cancelled Details Build test / mingw64 (push) Has been cancelled Details Build test / ucrt64 (push) Has been cancelled Details Current code perform a version downgrade at one place only, the end of fdt_rw_probe_(). In order to offer a finer grain and choose to downgrade or not depending on the exact writes done, introduce fdt_downgrade_version() to perform the downgrade operation. The modification doesn't introduce any functional changes. Signed-off-by: Herve Codina <herve.codina@bootlin.com> Message-ID: <20260210173349.636766-5-herve.codina@bootlin.com> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>	2026-02-24 17:00:38 +11:00
Herve Codina	5bb5bedd34	fdtdump: Return an error code on wrong tag value fdtdump prints a message on stderr when it encounters a wrong tag and stop its processing without returning an error code. Having a wrong tag is really a failure. Indeed, the processing cannot continue. Be more strict. Stop the processing, print a message and return an error code. In other words, call die(). Signed-off-by: Herve Codina <herve.codina@bootlin.com> Message-ID: <20260210173349.636766-4-herve.codina@bootlin.com> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>	2026-02-24 16:52:47 +11:00