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 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 52 static inline bool fprobe_disabled(struct fprobe *fp) 53 { 54 return (fp) ? fp->flags & FPROBE_FL_DISABLED : false; 55 } 56 57 static 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 63 int register_fprobe(struct fprobe *fp, const char *filter, const char *notfilter); 64 int register_fprobe_ips(struct fprobe *fp, unsigned long *addrs, int num); 65 int register_fprobe_syms(struct fprobe *fp, const char **syms, int num); 66 int unregister_fprobe(struct fprobe *fp); 67 #else 68 static inline int register_fprobe(struct fprobe *fp, const char *filter, const char *notfilter) 69 { 70 return -EOPNOTSUPP; 71 } 72 static inline int register_fprobe_ips(struct fprobe *fp, unsigned long *addrs, int num) 73 { 74 return -EOPNOTSUPP; 75 } 76 static inline int register_fprobe_syms(struct fprobe *fp, const char **syms, int num) 77 { 78 return -EOPNOTSUPP; 79 } 80 static 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 */ 93 static 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 */ 105 static inline void enable_fprobe(struct fprobe *fp) 106 { 107 if (fp) 108 fp->flags &= ~FPROBE_FL_DISABLED; 109 } 110 111 #endif 112