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_handler: The callback function for function entry.
17 * @exit_handler: The callback function for function exit.
18 */
19 struct fprobe {
20 #ifdef CONFIG_FUNCTION_TRACER
21 /*
22 * If CONFIG_FUNCTION_TRACER is not set, CONFIG_FPROBE is disabled too.
23 * But user of fprobe may keep embedding the struct fprobe on their own
24 * code. To avoid build error, this will keep the fprobe data structure
25 * defined here, but remove ftrace_ops data structure.
26 */
27 struct ftrace_ops ops;
28 #endif
29 unsigned long nmissed;
30 unsigned int flags;
31 struct rethook *rethook;
32
33 void (*entry_handler)(struct fprobe *fp, unsigned long entry_ip, struct pt_regs *regs);
34 void (*exit_handler)(struct fprobe *fp, unsigned long entry_ip, struct pt_regs *regs);
35 };
36
37 /* This fprobe is soft-disabled. */
38 #define FPROBE_FL_DISABLED 1
39
40 /*
41 * This fprobe handler will be shared with kprobes.
42 * This flag must be set before registering.
43 */
44 #define FPROBE_FL_KPROBE_SHARED 2
45
fprobe_disabled(struct fprobe * fp)46 static inline bool fprobe_disabled(struct fprobe *fp)
47 {
48 return (fp) ? fp->flags & FPROBE_FL_DISABLED : false;
49 }
50
fprobe_shared_with_kprobes(struct fprobe * fp)51 static inline bool fprobe_shared_with_kprobes(struct fprobe *fp)
52 {
53 return (fp) ? fp->flags & FPROBE_FL_KPROBE_SHARED : false;
54 }
55
56 #ifdef CONFIG_FPROBE
57 int register_fprobe(struct fprobe *fp, const char *filter, const char *notfilter);
58 int register_fprobe_ips(struct fprobe *fp, unsigned long *addrs, int num);
59 int register_fprobe_syms(struct fprobe *fp, const char **syms, int num);
60 int unregister_fprobe(struct fprobe *fp);
61 #else
register_fprobe(struct fprobe * fp,const char * filter,const char * notfilter)62 static inline int register_fprobe(struct fprobe *fp, const char *filter, const char *notfilter)
63 {
64 return -EOPNOTSUPP;
65 }
register_fprobe_ips(struct fprobe * fp,unsigned long * addrs,int num)66 static inline int register_fprobe_ips(struct fprobe *fp, unsigned long *addrs, int num)
67 {
68 return -EOPNOTSUPP;
69 }
register_fprobe_syms(struct fprobe * fp,const char ** syms,int num)70 static inline int register_fprobe_syms(struct fprobe *fp, const char **syms, int num)
71 {
72 return -EOPNOTSUPP;
73 }
unregister_fprobe(struct fprobe * fp)74 static inline int unregister_fprobe(struct fprobe *fp)
75 {
76 return -EOPNOTSUPP;
77 }
78 #endif
79
80 /**
81 * disable_fprobe() - Disable fprobe
82 * @fp: The fprobe to be disabled.
83 *
84 * This will soft-disable @fp. Note that this doesn't remove the ftrace
85 * hooks from the function entry.
86 */
disable_fprobe(struct fprobe * fp)87 static inline void disable_fprobe(struct fprobe *fp)
88 {
89 if (fp)
90 fp->flags |= FPROBE_FL_DISABLED;
91 }
92
93 /**
94 * enable_fprobe() - Enable fprobe
95 * @fp: The fprobe to be enabled.
96 *
97 * This will soft-enable @fp.
98 */
enable_fprobe(struct fprobe * fp)99 static inline void enable_fprobe(struct fprobe *fp)
100 {
101 if (fp)
102 fp->flags &= ~FPROBE_FL_DISABLED;
103 }
104
105 #endif
106