Linux kernel mirror (for testing)
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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 struct pt_regs *regs, void *entry_data);
39 void (*exit_handler)(struct fprobe *fp, unsigned long entry_ip,
40 struct pt_regs *regs, void *entry_data);
41};
42
43/* This fprobe is soft-disabled. */
44#define FPROBE_FL_DISABLED 1
45
46/*
47 * This fprobe handler will be shared with kprobes.
48 * This flag must be set before registering.
49 */
50#define FPROBE_FL_KPROBE_SHARED 2
51
52static inline bool fprobe_disabled(struct fprobe *fp)
53{
54 return (fp) ? fp->flags & FPROBE_FL_DISABLED : false;
55}
56
57static inline bool fprobe_shared_with_kprobes(struct fprobe *fp)
58{
59 return (fp) ? fp->flags & FPROBE_FL_KPROBE_SHARED : false;
60}
61
62#ifdef CONFIG_FPROBE
63int register_fprobe(struct fprobe *fp, const char *filter, const char *notfilter);
64int register_fprobe_ips(struct fprobe *fp, unsigned long *addrs, int num);
65int register_fprobe_syms(struct fprobe *fp, const char **syms, int num);
66int unregister_fprobe(struct fprobe *fp);
67#else
68static inline int register_fprobe(struct fprobe *fp, const char *filter, const char *notfilter)
69{
70 return -EOPNOTSUPP;
71}
72static inline int register_fprobe_ips(struct fprobe *fp, unsigned long *addrs, int num)
73{
74 return -EOPNOTSUPP;
75}
76static inline int register_fprobe_syms(struct fprobe *fp, const char **syms, int num)
77{
78 return -EOPNOTSUPP;
79}
80static inline int unregister_fprobe(struct fprobe *fp)
81{
82 return -EOPNOTSUPP;
83}
84#endif
85
86/**
87 * disable_fprobe() - Disable fprobe
88 * @fp: The fprobe to be disabled.
89 *
90 * This will soft-disable @fp. Note that this doesn't remove the ftrace
91 * hooks from the function entry.
92 */
93static inline void disable_fprobe(struct fprobe *fp)
94{
95 if (fp)
96 fp->flags |= FPROBE_FL_DISABLED;
97}
98
99/**
100 * enable_fprobe() - Enable fprobe
101 * @fp: The fprobe to be enabled.
102 *
103 * This will soft-enable @fp.
104 */
105static inline void enable_fprobe(struct fprobe *fp)
106{
107 if (fp)
108 fp->flags &= ~FPROBE_FL_DISABLED;
109}
110
111#endif