[PATCH v2 5/8] module: Move 'struct module_signature' to UAPI

Thomas Weißschuh
2026-03-05T07:11:58Z

This structure definition is used outside the kernel proper.
For example in kmod and the kernel build environment.

To allow reuse, move it to a new UAPI header.

While it is not a true UAPI, it is a common practice to have
non-UAPI interface definitions in the kernel's UAPI headers.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
---
include/linux/module_signature.h | 28 +-----------------------
include/uapi/linux/module_signature.h | 41 +++++++++++++++++++++++++++++++++++
2 files changed, 42 insertions(+), 27 deletions(-)

diff --git a/include/linux/module_signature.h b/include/linux/module_signature.h
index 915549c779dc..db335d46787f 100644
--- a/include/linux/module_signature.h
+++ b/include/linux/module_signature.h
@@ -10,33 +10,7 @@
#define _LINUX_MODULE_SIGNATURE_H

#include <linux/types.h>
-
-/* In stripped ARM and x86-64 modules, ~ is surprisingly rare. */
-#define MODULE_SIGNATURE_MARKER "~Module signature appended~\n"
-
-enum module_signature_type {
- MODULE_SIGNATURE_TYPE_PKCS7 = 2, /* Signature in PKCS#7 message */
-};
-
-/*
- * Module signature information block.
- *
- * The constituents of the signature section are, in order:
- *
- * - Signer's name
- * - Key identifier
- * - Signature data
- * - Information block
- */
-struct module_signature {
- u8 algo; /* Public-key crypto algorithm [0] */
- u8 hash; /* Digest algorithm [0] */
- u8 id_type; /* Key identifier type [enum module_signature_type] */
- u8 signer_len; /* Length of signer's name [0] */
- u8 key_id_len; /* Length of key identifier [0] */
- u8 __pad[3];
- __be32 sig_len; /* Length of signature data */
-};
+#include <uapi/linux/module_signature.h>

int mod_check_sig(const struct module_signature *ms, size_t file_len,
const char *name);
diff --git a/include/uapi/linux/module_signature.h b/include/uapi/linux/module_signature.h
new file mode 100644
index 000000000000..634c9f1c8fc2
--- /dev/null
+++ b/include/uapi/linux/module_signature.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+/*
+ * Module signature handling.
+ *
+ * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#ifndef _UAPI_LINUX_MODULE_SIGNATURE_H
+#define _UAPI_LINUX_MODULE_SIGNATURE_H
+
+#include <linux/types.h>
+
+/* In stripped ARM and x86-64 modules, ~ is surprisingly rare. */
+#define MODULE_SIGNATURE_MARKER "~Module signature appended~\n"
+
+enum module_signature_type {
+ MODULE_SIGNATURE_TYPE_PKCS7 = 2, /* Signature in PKCS#7 message */
+};
+
+/*
+ * Module signature information block.
+ *
+ * The constituents of the signature section are, in order:
+ *
+ * - Signer's name
+ * - Key identifier
+ * - Signature data
+ * - Information block
+ */
+struct module_signature {
+ __u8 algo; /* Public-key crypto algorithm [0] */
+ __u8 hash; /* Digest algorithm [0] */
+ __u8 id_type; /* Key identifier type [enum module_signature_type] */
+ __u8 signer_len; /* Length of signer's name [0] */
+ __u8 key_id_len; /* Length of key identifier [0] */
+ __u8 __pad[3];
+ __be32 sig_len; /* Length of signature data */
+};
+
+#endif /* _UAPI_LINUX_MODULE_SIGNATURE_H */

--
2.53.0