1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * code tagging framework
4 */
5 #ifndef _LINUX_CODETAG_H
6 #define _LINUX_CODETAG_H
7
8 #include <linux/types.h>
9
10 struct codetag_iterator;
11 struct codetag_type;
12 struct codetag_module;
13 struct seq_buf;
14 struct module;
15
16 /*
17 * An instance of this structure is created in a special ELF section at every
18 * code location being tagged. At runtime, the special section is treated as
19 * an array of these.
20 */
21 struct codetag {
22 unsigned int flags; /* used in later patches */
23 unsigned int lineno;
24 const char *modname;
25 const char *function;
26 const char *filename;
27 } __aligned(8);
28
29 union codetag_ref {
30 struct codetag *ct;
31 };
32
33 struct codetag_type_desc {
34 const char *section;
35 size_t tag_size;
36 void (*module_load)(struct codetag_type *cttype,
37 struct codetag_module *cmod);
38 bool (*module_unload)(struct codetag_type *cttype,
39 struct codetag_module *cmod);
40 };
41
42 struct codetag_iterator {
43 struct codetag_type *cttype;
44 struct codetag_module *cmod;
45 unsigned long mod_id;
46 struct codetag *ct;
47 };
48
49 #ifdef MODULE
50 #define CT_MODULE_NAME KBUILD_MODNAME
51 #else
52 #define CT_MODULE_NAME NULL
53 #endif
54
55 #define CODE_TAG_INIT { \
56 .modname = CT_MODULE_NAME, \
57 .function = __func__, \
58 .filename = __FILE__, \
59 .lineno = __LINE__, \
60 .flags = 0, \
61 }
62
63 void codetag_lock_module_list(struct codetag_type *cttype, bool lock);
64 bool codetag_trylock_module_list(struct codetag_type *cttype);
65 struct codetag_iterator codetag_get_ct_iter(struct codetag_type *cttype);
66 struct codetag *codetag_next_ct(struct codetag_iterator *iter);
67
68 void codetag_to_text(struct seq_buf *out, struct codetag *ct);
69
70 struct codetag_type *
71 codetag_register_type(const struct codetag_type_desc *desc);
72
73 #if defined(CONFIG_CODE_TAGGING) && defined(CONFIG_MODULES)
74 void codetag_load_module(struct module *mod);
75 bool codetag_unload_module(struct module *mod);
76 #else
codetag_load_module(struct module * mod)77 static inline void codetag_load_module(struct module *mod) {}
codetag_unload_module(struct module * mod)78 static inline bool codetag_unload_module(struct module *mod) { return true; }
79 #endif
80
81 #endif /* _LINUX_CODETAG_H */
82