1/* SPDX-License-Identifier: GPL-2.0 */
2/* Simple ftrace probe wrapper */
3#ifndef _LINUX_FPROBE_H
4#define _LINUX_FPROBE_H
5
6#include <linux/compiler.h>
7#include <linux/ftrace.h>
8#include <linux/rethook.h>
9
10/**
11 * struct fprobe - ftrace based probe.
12 * @ops: The ftrace_ops.
13 * @nmissed: The counter for missing events.
14 * @flags: The status flag.
15 * @rethook: The rethook data structure. (internal data)
16 * @entry_data_size: The private data storage size.
17 * @nr_maxactive: The max number of active functions.
18 * @entry_handler: The callback function for function entry.
19 * @exit_handler: The callback function for function exit.
20 */
21struct fprobe {
22#ifdef CONFIG_FUNCTION_TRACER
23	/*
24	 * If CONFIG_FUNCTION_TRACER is not set, CONFIG_FPROBE is disabled too.
25	 * But user of fprobe may keep embedding the struct fprobe on their own
26	 * code. To avoid build error, this will keep the fprobe data structure
27	 * defined here, but remove ftrace_ops data structure.
28	 */
29	struct ftrace_ops	ops;
30#endif
31	unsigned long		nmissed;
32	unsigned int		flags;
33	struct rethook		*rethook;
34	size_t			entry_data_size;
35	int			nr_maxactive;
36
37	int (*entry_handler)(struct fprobe *fp, unsigned long entry_ip,
38			     unsigned long ret_ip, struct pt_regs *regs,
39			     void *entry_data);
40	void (*exit_handler)(struct fprobe *fp, unsigned long entry_ip,
41			     unsigned long ret_ip, struct pt_regs *regs,
42			     void *entry_data);
43};
44
45/* This fprobe is soft-disabled. */
46#define FPROBE_FL_DISABLED	1
47
48/*
49 * This fprobe handler will be shared with kprobes.
50 * This flag must be set before registering.
51 */
52#define FPROBE_FL_KPROBE_SHARED	2
53
54static inline bool fprobe_disabled(struct fprobe *fp)
55{
56	return (fp) ? fp->flags & FPROBE_FL_DISABLED : false;
57}
58
59static inline bool fprobe_shared_with_kprobes(struct fprobe *fp)
60{
61	return (fp) ? fp->flags & FPROBE_FL_KPROBE_SHARED : false;
62}
63
64#ifdef CONFIG_FPROBE
65int register_fprobe(struct fprobe *fp, const char *filter, const char *notfilter);
66int register_fprobe_ips(struct fprobe *fp, unsigned long *addrs, int num);
67int register_fprobe_syms(struct fprobe *fp, const char **syms, int num);
68int unregister_fprobe(struct fprobe *fp);
69bool fprobe_is_registered(struct fprobe *fp);
70#else
71static inline int register_fprobe(struct fprobe *fp, const char *filter, const char *notfilter)
72{
73	return -EOPNOTSUPP;
74}
75static inline int register_fprobe_ips(struct fprobe *fp, unsigned long *addrs, int num)
76{
77	return -EOPNOTSUPP;
78}
79static inline int register_fprobe_syms(struct fprobe *fp, const char **syms, int num)
80{
81	return -EOPNOTSUPP;
82}
83static inline int unregister_fprobe(struct fprobe *fp)
84{
85	return -EOPNOTSUPP;
86}
87static inline bool fprobe_is_registered(struct fprobe *fp)
88{
89	return false;
90}
91#endif
92
93/**
94 * disable_fprobe() - Disable fprobe
95 * @fp: The fprobe to be disabled.
96 *
97 * This will soft-disable @fp. Note that this doesn't remove the ftrace
98 * hooks from the function entry.
99 */
100static inline void disable_fprobe(struct fprobe *fp)
101{
102	if (fp)
103		fp->flags |= FPROBE_FL_DISABLED;
104}
105
106/**
107 * enable_fprobe() - Enable fprobe
108 * @fp: The fprobe to be enabled.
109 *
110 * This will soft-enable @fp.
111 */
112static inline void enable_fprobe(struct fprobe *fp)
113{
114	if (fp)
115		fp->flags &= ~FPROBE_FL_DISABLED;
116}
117
118#endif
119