1 files changed, 111 insertions, 0 deletions
diff --git a/include/linux/codetag.h b/include/linux/codetag.h
new file mode 100644
index 000000000000..5f2b9a1f722c
--- /dev/null
+++ b/include/linux/codetag.h
@@ -0,0 +1,111 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * code tagging framework
+ */
+#ifndef _LINUX_CODETAG_H
+#define _LINUX_CODETAG_H
+
+#include <linux/types.h>
+
+struct codetag_iterator;
+struct codetag_type;
+struct codetag_module;
+struct seq_buf;
+struct module;
+
+#define CODETAG_SECTION_START_PREFIX	"__start_"
+#define CODETAG_SECTION_STOP_PREFIX	"__stop_"
+
+/*
+ * An instance of this structure is created in a special ELF section at every
+ * code location being tagged.  At runtime, the special section is treated as
+ * an array of these.
+ */
+struct codetag {
+	unsigned int flags; /* used in later patches */
+	unsigned int lineno;
+	const char *modname;
+	const char *function;
+	const char *filename;
+} __aligned(8);
+
+union codetag_ref {
+	struct codetag *ct;
+};
+
+struct codetag_type_desc {
+	const char *section;
+	size_t tag_size;
+	int (*module_load)(struct module *mod,
+			   struct codetag *start, struct codetag *end);
+	void (*module_unload)(struct module *mod,
+			      struct codetag *start, struct codetag *end);
+#ifdef CONFIG_MODULES
+	void (*module_replaced)(struct module *mod, struct module *new_mod);
+	bool (*needs_section_mem)(struct module *mod, unsigned long size);
+	void *(*alloc_section_mem)(struct module *mod, unsigned long size,
+				   unsigned int prepend, unsigned long align);
+	void (*free_section_mem)(struct module *mod, bool used);
+#endif
+};
+
+struct codetag_iterator {
+	struct codetag_type *cttype;
+	struct codetag_module *cmod;
+	unsigned long mod_id;
+	struct codetag *ct;
+};
+
+#ifdef MODULE
+#define CT_MODULE_NAME KBUILD_MODNAME
+#else
+#define CT_MODULE_NAME NULL
+#endif
+
+#define CODE_TAG_INIT {					\
+	.modname	= CT_MODULE_NAME,		\
+	.function	= __func__,			\
+	.filename	= __FILE__,			\
+	.lineno		= __LINE__,			\
+	.flags		= 0,				\
+}
+
+void codetag_lock_module_list(struct codetag_type *cttype, bool lock);
+bool codetag_trylock_module_list(struct codetag_type *cttype);
+struct codetag_iterator codetag_get_ct_iter(struct codetag_type *cttype);
+struct codetag *codetag_next_ct(struct codetag_iterator *iter);
+
+void codetag_to_text(struct seq_buf *out, struct codetag *ct);
+
+struct codetag_type *
+codetag_register_type(const struct codetag_type_desc *desc);
+
+#if defined(CONFIG_CODE_TAGGING) && defined(CONFIG_MODULES)
+
+bool codetag_needs_module_section(struct module *mod, const char *name,
+				  unsigned long size);
+void *codetag_alloc_module_section(struct module *mod, const char *name,
+				   unsigned long size, unsigned int prepend,
+				   unsigned long align);
+void codetag_free_module_sections(struct module *mod);
+void codetag_module_replaced(struct module *mod, struct module *new_mod);
+int codetag_load_module(struct module *mod);
+void codetag_unload_module(struct module *mod);
+
+#else /* defined(CONFIG_CODE_TAGGING) && defined(CONFIG_MODULES) */
+
+static inline bool
+codetag_needs_module_section(struct module *mod, const char *name,
+			     unsigned long size) { return false; }
+static inline void *
+codetag_alloc_module_section(struct module *mod, const char *name,
+			     unsigned long size, unsigned int prepend,
+			     unsigned long align) { return NULL; }
+static inline void codetag_free_module_sections(struct module *mod) {}
+static inline void codetag_module_replaced(struct module *mod, struct module *new_mod) {}
+static inline int codetag_load_module(struct module *mod) { return 0; }
+static inline void codetag_unload_module(struct module *mod) {}
+
+#endif /* defined(CONFIG_CODE_TAGGING) && defined(CONFIG_MODULES) */
+
+#endif /* _LINUX_CODETAG_H */