trace_dynevent.h (4781B)
1/* SPDX-License-Identifier: GPL-2.0 */ 2/* 3 * Common header file for generic dynamic events. 4 */ 5 6#ifndef _TRACE_DYNEVENT_H 7#define _TRACE_DYNEVENT_H 8 9#include <linux/kernel.h> 10#include <linux/list.h> 11#include <linux/mutex.h> 12#include <linux/seq_file.h> 13 14#include "trace.h" 15 16struct dyn_event; 17 18/** 19 * struct dyn_event_operations - Methods for each type of dynamic events 20 * 21 * These methods must be set for each type, since there is no default method. 22 * Before using this for dyn_event_init(), it must be registered by 23 * dyn_event_register(). 24 * 25 * @create: Parse and create event method. This is invoked when user passes 26 * a event definition to dynamic_events interface. This must not destruct 27 * the arguments and return -ECANCELED if given arguments doesn't match its 28 * command prefix. 29 * @show: Showing method. This is invoked when user reads the event definitions 30 * via dynamic_events interface. 31 * @is_busy: Check whether given event is busy so that it can not be deleted. 32 * Return true if it is busy, otherwise false. 33 * @free: Delete the given event. Return 0 if success, otherwise error. 34 * @match: Check whether given event and system name match this event. The argc 35 * and argv is used for exact match. Return true if it matches, otherwise 36 * false. 37 * 38 * Except for @create, these methods are called under holding event_mutex. 39 */ 40struct dyn_event_operations { 41 struct list_head list; 42 int (*create)(const char *raw_command); 43 int (*show)(struct seq_file *m, struct dyn_event *ev); 44 bool (*is_busy)(struct dyn_event *ev); 45 int (*free)(struct dyn_event *ev); 46 bool (*match)(const char *system, const char *event, 47 int argc, const char **argv, struct dyn_event *ev); 48}; 49 50/* Register new dyn_event type -- must be called at first */ 51int dyn_event_register(struct dyn_event_operations *ops); 52 53/** 54 * struct dyn_event - Dynamic event list header 55 * 56 * The dyn_event structure encapsulates a list and a pointer to the operators 57 * for making a global list of dynamic events. 58 * User must includes this in each event structure, so that those events can 59 * be added/removed via dynamic_events interface. 60 */ 61struct dyn_event { 62 struct list_head list; 63 struct dyn_event_operations *ops; 64}; 65 66extern struct list_head dyn_event_list; 67 68static inline 69int dyn_event_init(struct dyn_event *ev, struct dyn_event_operations *ops) 70{ 71 if (!ev || !ops) 72 return -EINVAL; 73 74 INIT_LIST_HEAD(&ev->list); 75 ev->ops = ops; 76 return 0; 77} 78 79static inline int dyn_event_add(struct dyn_event *ev, 80 struct trace_event_call *call) 81{ 82 lockdep_assert_held(&event_mutex); 83 84 if (!ev || !ev->ops) 85 return -EINVAL; 86 87 call->flags |= TRACE_EVENT_FL_DYNAMIC; 88 list_add_tail(&ev->list, &dyn_event_list); 89 return 0; 90} 91 92static inline void dyn_event_remove(struct dyn_event *ev) 93{ 94 lockdep_assert_held(&event_mutex); 95 list_del_init(&ev->list); 96} 97 98void *dyn_event_seq_start(struct seq_file *m, loff_t *pos); 99void *dyn_event_seq_next(struct seq_file *m, void *v, loff_t *pos); 100void dyn_event_seq_stop(struct seq_file *m, void *v); 101int dyn_events_release_all(struct dyn_event_operations *type); 102int dyn_event_release(const char *raw_command, struct dyn_event_operations *type); 103 104/* 105 * for_each_dyn_event - iterate over the dyn_event list 106 * @pos: the struct dyn_event * to use as a loop cursor 107 * 108 * This is just a basement of for_each macro. Wrap this for 109 * each actual event structure with ops filtering. 110 */ 111#define for_each_dyn_event(pos) \ 112 list_for_each_entry(pos, &dyn_event_list, list) 113 114/* 115 * for_each_dyn_event - iterate over the dyn_event list safely 116 * @pos: the struct dyn_event * to use as a loop cursor 117 * @n: the struct dyn_event * to use as temporary storage 118 */ 119#define for_each_dyn_event_safe(pos, n) \ 120 list_for_each_entry_safe(pos, n, &dyn_event_list, list) 121 122extern void dynevent_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen, 123 enum dynevent_type type, 124 dynevent_create_fn_t run_command); 125 126typedef int (*dynevent_check_arg_fn_t)(void *data); 127 128struct dynevent_arg { 129 const char *str; 130 char separator; /* e.g. ';', ',', or nothing */ 131}; 132 133extern void dynevent_arg_init(struct dynevent_arg *arg, 134 char separator); 135extern int dynevent_arg_add(struct dynevent_cmd *cmd, 136 struct dynevent_arg *arg, 137 dynevent_check_arg_fn_t check_arg); 138 139struct dynevent_arg_pair { 140 const char *lhs; 141 const char *rhs; 142 char operator; /* e.g. '=' or nothing */ 143 char separator; /* e.g. ';', ',', or nothing */ 144}; 145 146extern void dynevent_arg_pair_init(struct dynevent_arg_pair *arg_pair, 147 char operator, char separator); 148 149extern int dynevent_arg_pair_add(struct dynevent_cmd *cmd, 150 struct dynevent_arg_pair *arg_pair, 151 dynevent_check_arg_fn_t check_arg); 152extern int dynevent_str_add(struct dynevent_cmd *cmd, const char *str); 153 154#endif