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 */ 21 struct 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 54 static inline bool fprobe_disabled(struct fprobe *fp) 55 { 56 return (fp) ? fp->flags & FPROBE_FL_DISABLED : false; 57 } 58 59 static 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 65 int register_fprobe(struct fprobe *fp, const char *filter, const char *notfilter); 66 int register_fprobe_ips(struct fprobe *fp, unsigned long *addrs, int num); 67 int register_fprobe_syms(struct fprobe *fp, const char **syms, int num); 68 int unregister_fprobe(struct fprobe *fp); 69 #else 70 static inline int register_fprobe(struct fprobe *fp, const char *filter, const char *notfilter) 71 { 72 return -EOPNOTSUPP; 73 } 74 static inline int register_fprobe_ips(struct fprobe *fp, unsigned long *addrs, int num) 75 { 76 return -EOPNOTSUPP; 77 } 78 static inline int register_fprobe_syms(struct fprobe *fp, const char **syms, int num) 79 { 80 return -EOPNOTSUPP; 81 } 82 static inline int unregister_fprobe(struct fprobe *fp) 83 { 84 return -EOPNOTSUPP; 85 } 86 #endif 87 88 /** 89 * disable_fprobe() - Disable fprobe 90 * @fp: The fprobe to be disabled. 91 * 92 * This will soft-disable @fp. Note that this doesn't remove the ftrace 93 * hooks from the function entry. 94 */ 95 static inline void disable_fprobe(struct fprobe *fp) 96 { 97 if (fp) 98 fp->flags |= FPROBE_FL_DISABLED; 99 } 100 101 /** 102 * enable_fprobe() - Enable fprobe 103 * @fp: The fprobe to be enabled. 104 * 105 * This will soft-enable @fp. 106 */ 107 static inline void enable_fprobe(struct fprobe *fp) 108 { 109 if (fp) 110 fp->flags &= ~FPROBE_FL_DISABLED; 111 } 112 113 #endif 114