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 #define FPROBE_FL_DISABLED 1 38 39 static inline bool fprobe_disabled(struct fprobe *fp) 40 { 41 return (fp) ? fp->flags & FPROBE_FL_DISABLED : false; 42 } 43 44 #ifdef CONFIG_FPROBE 45 int register_fprobe(struct fprobe *fp, const char *filter, const char *notfilter); 46 int register_fprobe_ips(struct fprobe *fp, unsigned long *addrs, int num); 47 int register_fprobe_syms(struct fprobe *fp, const char **syms, int num); 48 int unregister_fprobe(struct fprobe *fp); 49 #else 50 static inline int register_fprobe(struct fprobe *fp, const char *filter, const char *notfilter) 51 { 52 return -EOPNOTSUPP; 53 } 54 static inline int register_fprobe_ips(struct fprobe *fp, unsigned long *addrs, int num) 55 { 56 return -EOPNOTSUPP; 57 } 58 static inline int register_fprobe_syms(struct fprobe *fp, const char **syms, int num) 59 { 60 return -EOPNOTSUPP; 61 } 62 static inline int unregister_fprobe(struct fprobe *fp) 63 { 64 return -EOPNOTSUPP; 65 } 66 #endif 67 68 /** 69 * disable_fprobe() - Disable fprobe 70 * @fp: The fprobe to be disabled. 71 * 72 * This will soft-disable @fp. Note that this doesn't remove the ftrace 73 * hooks from the function entry. 74 */ 75 static inline void disable_fprobe(struct fprobe *fp) 76 { 77 if (fp) 78 fp->flags |= FPROBE_FL_DISABLED; 79 } 80 81 /** 82 * enable_fprobe() - Enable fprobe 83 * @fp: The fprobe to be enabled. 84 * 85 * This will soft-enable @fp. 86 */ 87 static inline void enable_fprobe(struct fprobe *fp) 88 { 89 if (fp) 90 fp->flags &= ~FPROBE_FL_DISABLED; 91 } 92 93 #endif 94