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 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 54static inline bool fprobe_disabled(struct fprobe *fp) 55{ 56 return (fp) ? fp->flags & FPROBE_FL_DISABLED : false; 57} 58 59static 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 65int register_fprobe(struct fprobe *fp, const char *filter, const char *notfilter); 66int register_fprobe_ips(struct fprobe *fp, unsigned long *addrs, int num); 67int register_fprobe_syms(struct fprobe *fp, const char **syms, int num); 68int unregister_fprobe(struct fprobe *fp); 69bool fprobe_is_registered(struct fprobe *fp); 70#else 71static inline int register_fprobe(struct fprobe *fp, const char *filter, const char *notfilter) 72{ 73 return -EOPNOTSUPP; 74} 75static inline int register_fprobe_ips(struct fprobe *fp, unsigned long *addrs, int num) 76{ 77 return -EOPNOTSUPP; 78} 79static inline int register_fprobe_syms(struct fprobe *fp, const char **syms, int num) 80{ 81 return -EOPNOTSUPP; 82} 83static inline int unregister_fprobe(struct fprobe *fp) 84{ 85 return -EOPNOTSUPP; 86} 87static inline bool fprobe_is_registered(struct fprobe *fp) 88{ 89 return false; 90} 91#endif 92 93/** 94 * disable_fprobe() - Disable fprobe 95 * @fp: The fprobe to be disabled. 96 * 97 * This will soft-disable @fp. Note that this doesn't remove the ftrace 98 * hooks from the function entry. 99 */ 100static inline void disable_fprobe(struct fprobe *fp) 101{ 102 if (fp) 103 fp->flags |= FPROBE_FL_DISABLED; 104} 105 106/** 107 * enable_fprobe() - Enable fprobe 108 * @fp: The fprobe to be enabled. 109 * 110 * This will soft-enable @fp. 111 */ 112static inline void enable_fprobe(struct fprobe *fp) 113{ 114 if (fp) 115 fp->flags &= ~FPROBE_FL_DISABLED; 116} 117 118#endif 119