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 struct fprobe; 11 12 typedef int (*fprobe_entry_cb)(struct fprobe *fp, unsigned long entry_ip, 13 unsigned long ret_ip, struct pt_regs *regs, 14 void *entry_data); 15 16 typedef void (*fprobe_exit_cb)(struct fprobe *fp, unsigned long entry_ip, 17 unsigned long ret_ip, struct pt_regs *regs, 18 void *entry_data); 19 20 /** 21 * struct fprobe - ftrace based probe. 22 * @ops: The ftrace_ops. 23 * @nmissed: The counter for missing events. 24 * @flags: The status flag. 25 * @rethook: The rethook data structure. (internal data) 26 * @entry_data_size: The private data storage size. 27 * @nr_maxactive: The max number of active functions. 28 * @entry_handler: The callback function for function entry. 29 * @exit_handler: The callback function for function exit. 30 */ 31 struct fprobe { 32 #ifdef CONFIG_FUNCTION_TRACER 33 /* 34 * If CONFIG_FUNCTION_TRACER is not set, CONFIG_FPROBE is disabled too. 35 * But user of fprobe may keep embedding the struct fprobe on their own 36 * code. To avoid build error, this will keep the fprobe data structure 37 * defined here, but remove ftrace_ops data structure. 38 */ 39 struct ftrace_ops ops; 40 #endif 41 unsigned long nmissed; 42 unsigned int flags; 43 struct rethook *rethook; 44 size_t entry_data_size; 45 int nr_maxactive; 46 47 fprobe_entry_cb entry_handler; 48 fprobe_exit_cb exit_handler; 49 }; 50 51 /* This fprobe is soft-disabled. */ 52 #define FPROBE_FL_DISABLED 1 53 54 /* 55 * This fprobe handler will be shared with kprobes. 56 * This flag must be set before registering. 57 */ 58 #define FPROBE_FL_KPROBE_SHARED 2 59 60 static inline bool fprobe_disabled(struct fprobe *fp) 61 { 62 return (fp) ? fp->flags & FPROBE_FL_DISABLED : false; 63 } 64 65 static inline bool fprobe_shared_with_kprobes(struct fprobe *fp) 66 { 67 return (fp) ? fp->flags & FPROBE_FL_KPROBE_SHARED : false; 68 } 69 70 #ifdef CONFIG_FPROBE 71 int register_fprobe(struct fprobe *fp, const char *filter, const char *notfilter); 72 int register_fprobe_ips(struct fprobe *fp, unsigned long *addrs, int num); 73 int register_fprobe_syms(struct fprobe *fp, const char **syms, int num); 74 int unregister_fprobe(struct fprobe *fp); 75 bool fprobe_is_registered(struct fprobe *fp); 76 #else 77 static inline int register_fprobe(struct fprobe *fp, const char *filter, const char *notfilter) 78 { 79 return -EOPNOTSUPP; 80 } 81 static inline int register_fprobe_ips(struct fprobe *fp, unsigned long *addrs, int num) 82 { 83 return -EOPNOTSUPP; 84 } 85 static inline int register_fprobe_syms(struct fprobe *fp, const char **syms, int num) 86 { 87 return -EOPNOTSUPP; 88 } 89 static inline int unregister_fprobe(struct fprobe *fp) 90 { 91 return -EOPNOTSUPP; 92 } 93 static inline bool fprobe_is_registered(struct fprobe *fp) 94 { 95 return false; 96 } 97 #endif 98 99 /** 100 * disable_fprobe() - Disable fprobe 101 * @fp: The fprobe to be disabled. 102 * 103 * This will soft-disable @fp. Note that this doesn't remove the ftrace 104 * hooks from the function entry. 105 */ 106 static inline void disable_fprobe(struct fprobe *fp) 107 { 108 if (fp) 109 fp->flags |= FPROBE_FL_DISABLED; 110 } 111 112 /** 113 * enable_fprobe() - Enable fprobe 114 * @fp: The fprobe to be enabled. 115 * 116 * This will soft-enable @fp. 117 */ 118 static inline void enable_fprobe(struct fprobe *fp) 119 { 120 if (fp) 121 fp->flags &= ~FPROBE_FL_DISABLED; 122 } 123 124 #endif 125