Mathieu Desnoyers | 97e1c18 | 2008-07-18 12:16:16 -0400 | [diff] [blame] | 1 | #ifndef _LINUX_TRACEPOINT_H |
| 2 | #define _LINUX_TRACEPOINT_H |
| 3 | |
| 4 | /* |
| 5 | * Kernel Tracepoint API. |
| 6 | * |
| 7 | * See Documentation/tracepoint.txt. |
| 8 | * |
| 9 | * (C) Copyright 2008 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> |
| 10 | * |
| 11 | * Heavily inspired from the Linux Kernel Markers. |
| 12 | * |
| 13 | * This file is released under the GPLv2. |
| 14 | * See the file COPYING for more details. |
| 15 | */ |
| 16 | |
| 17 | #include <linux/types.h> |
| 18 | #include <linux/rcupdate.h> |
| 19 | |
| 20 | struct module; |
| 21 | struct tracepoint; |
| 22 | |
| 23 | struct tracepoint { |
| 24 | const char *name; /* Tracepoint name */ |
| 25 | int state; /* State. */ |
| 26 | void **funcs; |
Mathieu Desnoyers | 7e066fb | 2008-11-14 17:47:47 -0500 | [diff] [blame] | 27 | } __attribute__((aligned(32))); /* |
| 28 | * Aligned on 32 bytes because it is |
| 29 | * globally visible and gcc happily |
| 30 | * align these on the structure size. |
| 31 | * Keep in sync with vmlinux.lds.h. |
| 32 | */ |
Mathieu Desnoyers | 97e1c18 | 2008-07-18 12:16:16 -0400 | [diff] [blame] | 33 | |
Steven Rostedt | ea20d92 | 2009-04-10 08:54:16 -0400 | [diff] [blame] | 34 | #ifndef DECLARE_TRACE |
| 35 | |
Steven Rostedt | 2939b04 | 2009-03-09 15:47:18 -0400 | [diff] [blame] | 36 | #define TP_PROTO(args...) args |
| 37 | #define TP_ARGS(args...) args |
Mathieu Desnoyers | 97e1c18 | 2008-07-18 12:16:16 -0400 | [diff] [blame] | 38 | |
| 39 | #ifdef CONFIG_TRACEPOINTS |
| 40 | |
| 41 | /* |
| 42 | * it_func[0] is never NULL because there is at least one element in the array |
| 43 | * when the array itself is non NULL. |
| 44 | */ |
| 45 | #define __DO_TRACE(tp, proto, args) \ |
| 46 | do { \ |
| 47 | void **it_func; \ |
| 48 | \ |
Mathieu Desnoyers | da7b3ea | 2008-11-14 17:47:43 -0500 | [diff] [blame] | 49 | rcu_read_lock_sched_notrace(); \ |
Mathieu Desnoyers | 97e1c18 | 2008-07-18 12:16:16 -0400 | [diff] [blame] | 50 | it_func = rcu_dereference((tp)->funcs); \ |
| 51 | if (it_func) { \ |
| 52 | do { \ |
| 53 | ((void(*)(proto))(*it_func))(args); \ |
| 54 | } while (*(++it_func)); \ |
| 55 | } \ |
Mathieu Desnoyers | da7b3ea | 2008-11-14 17:47:43 -0500 | [diff] [blame] | 56 | rcu_read_unlock_sched_notrace(); \ |
Mathieu Desnoyers | 97e1c18 | 2008-07-18 12:16:16 -0400 | [diff] [blame] | 57 | } while (0) |
| 58 | |
| 59 | /* |
| 60 | * Make sure the alignment of the structure in the __tracepoints section will |
| 61 | * not add unwanted padding between the beginning of the section and the |
| 62 | * structure. Force alignment to the same alignment as the section start. |
Jason Baron | 63fbdab | 2009-08-10 16:52:27 -0400 | [diff] [blame] | 63 | * An optional set of (un)registration functions can be passed to perform any |
| 64 | * additional (un)registration work. |
Mathieu Desnoyers | 97e1c18 | 2008-07-18 12:16:16 -0400 | [diff] [blame] | 65 | */ |
Jason Baron | 63fbdab | 2009-08-10 16:52:27 -0400 | [diff] [blame] | 66 | #define DECLARE_TRACE_WITH_CALLBACK(name, proto, args, reg, unreg) \ |
Mathieu Desnoyers | 7e066fb | 2008-11-14 17:47:47 -0500 | [diff] [blame] | 67 | extern struct tracepoint __tracepoint_##name; \ |
Mathieu Desnoyers | 97e1c18 | 2008-07-18 12:16:16 -0400 | [diff] [blame] | 68 | static inline void trace_##name(proto) \ |
| 69 | { \ |
Mathieu Desnoyers | 97e1c18 | 2008-07-18 12:16:16 -0400 | [diff] [blame] | 70 | if (unlikely(__tracepoint_##name.state)) \ |
| 71 | __DO_TRACE(&__tracepoint_##name, \ |
Steven Rostedt | 2939b04 | 2009-03-09 15:47:18 -0400 | [diff] [blame] | 72 | TP_PROTO(proto), TP_ARGS(args)); \ |
Mathieu Desnoyers | 97e1c18 | 2008-07-18 12:16:16 -0400 | [diff] [blame] | 73 | } \ |
| 74 | static inline int register_trace_##name(void (*probe)(proto)) \ |
| 75 | { \ |
Jason Baron | 63fbdab | 2009-08-10 16:52:27 -0400 | [diff] [blame] | 76 | int ret; \ |
| 77 | void (*func)(void) = reg; \ |
| 78 | \ |
| 79 | ret = tracepoint_probe_register(#name, (void *)probe); \ |
| 80 | if (func && !ret) \ |
| 81 | func(); \ |
| 82 | return ret; \ |
Mathieu Desnoyers | 97e1c18 | 2008-07-18 12:16:16 -0400 | [diff] [blame] | 83 | } \ |
Mathieu Desnoyers | c420970 | 2008-11-14 17:47:44 -0500 | [diff] [blame] | 84 | static inline int unregister_trace_##name(void (*probe)(proto)) \ |
Mathieu Desnoyers | 97e1c18 | 2008-07-18 12:16:16 -0400 | [diff] [blame] | 85 | { \ |
Jason Baron | 63fbdab | 2009-08-10 16:52:27 -0400 | [diff] [blame] | 86 | int ret; \ |
| 87 | void (*func)(void) = unreg; \ |
| 88 | \ |
| 89 | ret = tracepoint_probe_unregister(#name, (void *)probe);\ |
| 90 | if (func && !ret) \ |
| 91 | func(); \ |
| 92 | return ret; \ |
Mathieu Desnoyers | 97e1c18 | 2008-07-18 12:16:16 -0400 | [diff] [blame] | 93 | } |
| 94 | |
Jason Baron | 63fbdab | 2009-08-10 16:52:27 -0400 | [diff] [blame] | 95 | |
| 96 | #define DECLARE_TRACE(name, proto, args) \ |
| 97 | DECLARE_TRACE_WITH_CALLBACK(name, TP_PROTO(proto), TP_ARGS(args),\ |
| 98 | NULL, NULL); |
| 99 | |
Mathieu Desnoyers | 7e066fb | 2008-11-14 17:47:47 -0500 | [diff] [blame] | 100 | #define DEFINE_TRACE(name) \ |
| 101 | static const char __tpstrtab_##name[] \ |
| 102 | __attribute__((section("__tracepoints_strings"))) = #name; \ |
| 103 | struct tracepoint __tracepoint_##name \ |
| 104 | __attribute__((section("__tracepoints"), aligned(32))) = \ |
| 105 | { __tpstrtab_##name, 0, NULL } |
| 106 | |
| 107 | #define EXPORT_TRACEPOINT_SYMBOL_GPL(name) \ |
| 108 | EXPORT_SYMBOL_GPL(__tracepoint_##name) |
| 109 | #define EXPORT_TRACEPOINT_SYMBOL(name) \ |
| 110 | EXPORT_SYMBOL(__tracepoint_##name) |
| 111 | |
Mathieu Desnoyers | 97e1c18 | 2008-07-18 12:16:16 -0400 | [diff] [blame] | 112 | extern void tracepoint_update_probe_range(struct tracepoint *begin, |
| 113 | struct tracepoint *end); |
| 114 | |
| 115 | #else /* !CONFIG_TRACEPOINTS */ |
Jason Baron | 63fbdab | 2009-08-10 16:52:27 -0400 | [diff] [blame] | 116 | #define DECLARE_TRACE_WITH_CALLBACK(name, proto, args, reg, unreg) \ |
Mathieu Desnoyers | 97e1c18 | 2008-07-18 12:16:16 -0400 | [diff] [blame] | 117 | static inline void _do_trace_##name(struct tracepoint *tp, proto) \ |
| 118 | { } \ |
| 119 | static inline void trace_##name(proto) \ |
| 120 | { } \ |
| 121 | static inline int register_trace_##name(void (*probe)(proto)) \ |
| 122 | { \ |
| 123 | return -ENOSYS; \ |
| 124 | } \ |
Mathieu Desnoyers | c420970 | 2008-11-14 17:47:44 -0500 | [diff] [blame] | 125 | static inline int unregister_trace_##name(void (*probe)(proto)) \ |
| 126 | { \ |
| 127 | return -ENOSYS; \ |
| 128 | } |
Mathieu Desnoyers | 97e1c18 | 2008-07-18 12:16:16 -0400 | [diff] [blame] | 129 | |
Jason Baron | 63fbdab | 2009-08-10 16:52:27 -0400 | [diff] [blame] | 130 | #define DECLARE_TRACE(name, proto, args) \ |
| 131 | DECLARE_TRACE_WITH_CALLBACK(name, TP_PROTO(proto), TP_ARGS(args),\ |
| 132 | NULL, NULL); |
| 133 | |
Mathieu Desnoyers | 7e066fb | 2008-11-14 17:47:47 -0500 | [diff] [blame] | 134 | #define DEFINE_TRACE(name) |
| 135 | #define EXPORT_TRACEPOINT_SYMBOL_GPL(name) |
| 136 | #define EXPORT_TRACEPOINT_SYMBOL(name) |
| 137 | |
Mathieu Desnoyers | 97e1c18 | 2008-07-18 12:16:16 -0400 | [diff] [blame] | 138 | static inline void tracepoint_update_probe_range(struct tracepoint *begin, |
| 139 | struct tracepoint *end) |
| 140 | { } |
| 141 | #endif /* CONFIG_TRACEPOINTS */ |
Steven Rostedt | ea20d92 | 2009-04-10 08:54:16 -0400 | [diff] [blame] | 142 | #endif /* DECLARE_TRACE */ |
Mathieu Desnoyers | 97e1c18 | 2008-07-18 12:16:16 -0400 | [diff] [blame] | 143 | |
| 144 | /* |
| 145 | * Connect a probe to a tracepoint. |
| 146 | * Internal API, should not be used directly. |
| 147 | */ |
| 148 | extern int tracepoint_probe_register(const char *name, void *probe); |
| 149 | |
| 150 | /* |
| 151 | * Disconnect a probe from a tracepoint. |
| 152 | * Internal API, should not be used directly. |
| 153 | */ |
| 154 | extern int tracepoint_probe_unregister(const char *name, void *probe); |
| 155 | |
Lai Jiangshan | 127cafb | 2008-10-28 10:51:53 +0800 | [diff] [blame] | 156 | extern int tracepoint_probe_register_noupdate(const char *name, void *probe); |
| 157 | extern int tracepoint_probe_unregister_noupdate(const char *name, void *probe); |
| 158 | extern void tracepoint_probe_update_all(void); |
| 159 | |
Mathieu Desnoyers | 97e1c18 | 2008-07-18 12:16:16 -0400 | [diff] [blame] | 160 | struct tracepoint_iter { |
| 161 | struct module *module; |
| 162 | struct tracepoint *tracepoint; |
| 163 | }; |
| 164 | |
| 165 | extern void tracepoint_iter_start(struct tracepoint_iter *iter); |
| 166 | extern void tracepoint_iter_next(struct tracepoint_iter *iter); |
| 167 | extern void tracepoint_iter_stop(struct tracepoint_iter *iter); |
| 168 | extern void tracepoint_iter_reset(struct tracepoint_iter *iter); |
| 169 | extern int tracepoint_get_iter_range(struct tracepoint **tracepoint, |
| 170 | struct tracepoint *begin, struct tracepoint *end); |
| 171 | |
Mathieu Desnoyers | f2461fc | 2008-10-06 10:33:00 -0400 | [diff] [blame] | 172 | /* |
| 173 | * tracepoint_synchronize_unregister must be called between the last tracepoint |
| 174 | * probe unregistration and the end of module exit to make sure there is no |
| 175 | * caller executing a probe when it is freed. |
| 176 | */ |
Mathieu Desnoyers | 231375c | 2008-10-03 15:01:33 -0400 | [diff] [blame] | 177 | static inline void tracepoint_synchronize_unregister(void) |
| 178 | { |
| 179 | synchronize_sched(); |
| 180 | } |
Mathieu Desnoyers | f2461fc | 2008-10-06 10:33:00 -0400 | [diff] [blame] | 181 | |
Steven Rostedt | 3cdfdf9 | 2009-02-25 15:54:30 -0500 | [diff] [blame] | 182 | #define PARAMS(args...) args |
Steven Rostedt | ea20d92 | 2009-04-10 08:54:16 -0400 | [diff] [blame] | 183 | |
Steven Rostedt | ea20d92 | 2009-04-10 08:54:16 -0400 | [diff] [blame] | 184 | #ifndef TRACE_EVENT |
Steven Rostedt | 823f912 | 2009-03-10 12:58:51 -0400 | [diff] [blame] | 185 | /* |
| 186 | * For use with the TRACE_EVENT macro: |
| 187 | * |
| 188 | * We define a tracepoint, its arguments, its printk format |
| 189 | * and its 'fast binay record' layout. |
| 190 | * |
| 191 | * Firstly, name your tracepoint via TRACE_EVENT(name : the |
| 192 | * 'subsystem_event' notation is fine. |
| 193 | * |
| 194 | * Think about this whole construct as the |
| 195 | * 'trace_sched_switch() function' from now on. |
| 196 | * |
| 197 | * |
| 198 | * TRACE_EVENT(sched_switch, |
| 199 | * |
| 200 | * * |
| 201 | * * A function has a regular function arguments |
| 202 | * * prototype, declare it via TP_PROTO(): |
| 203 | * * |
| 204 | * |
Steven Rostedt | ef18012 | 2009-03-10 14:10:56 -0400 | [diff] [blame] | 205 | * TP_PROTO(struct rq *rq, struct task_struct *prev, |
| 206 | * struct task_struct *next), |
Steven Rostedt | 823f912 | 2009-03-10 12:58:51 -0400 | [diff] [blame] | 207 | * |
| 208 | * * |
| 209 | * * Define the call signature of the 'function'. |
| 210 | * * (Design sidenote: we use this instead of a |
| 211 | * * TP_PROTO1/TP_PROTO2/TP_PROTO3 ugliness.) |
| 212 | * * |
| 213 | * |
Steven Rostedt | ef18012 | 2009-03-10 14:10:56 -0400 | [diff] [blame] | 214 | * TP_ARGS(rq, prev, next), |
Steven Rostedt | 823f912 | 2009-03-10 12:58:51 -0400 | [diff] [blame] | 215 | * |
| 216 | * * |
| 217 | * * Fast binary tracing: define the trace record via |
| 218 | * * TP_STRUCT__entry(). You can think about it like a |
| 219 | * * regular C structure local variable definition. |
| 220 | * * |
| 221 | * * This is how the trace record is structured and will |
| 222 | * * be saved into the ring buffer. These are the fields |
| 223 | * * that will be exposed to user-space in |
GeunSik Lim | 156f5a7 | 2009-06-02 15:01:37 +0900 | [diff] [blame] | 224 | * * /sys/kernel/debug/tracing/events/<*>/format. |
Steven Rostedt | 823f912 | 2009-03-10 12:58:51 -0400 | [diff] [blame] | 225 | * * |
| 226 | * * The declared 'local variable' is called '__entry' |
| 227 | * * |
| 228 | * * __field(pid_t, prev_prid) is equivalent to a standard declariton: |
| 229 | * * |
| 230 | * * pid_t prev_pid; |
| 231 | * * |
| 232 | * * __array(char, prev_comm, TASK_COMM_LEN) is equivalent to: |
| 233 | * * |
| 234 | * * char prev_comm[TASK_COMM_LEN]; |
| 235 | * * |
| 236 | * |
| 237 | * TP_STRUCT__entry( |
| 238 | * __array( char, prev_comm, TASK_COMM_LEN ) |
| 239 | * __field( pid_t, prev_pid ) |
| 240 | * __field( int, prev_prio ) |
| 241 | * __array( char, next_comm, TASK_COMM_LEN ) |
| 242 | * __field( pid_t, next_pid ) |
| 243 | * __field( int, next_prio ) |
| 244 | * ), |
| 245 | * |
| 246 | * * |
| 247 | * * Assign the entry into the trace record, by embedding |
| 248 | * * a full C statement block into TP_fast_assign(). You |
| 249 | * * can refer to the trace record as '__entry' - |
| 250 | * * otherwise you can put arbitrary C code in here. |
| 251 | * * |
| 252 | * * Note: this C code will execute every time a trace event |
| 253 | * * happens, on an active tracepoint. |
| 254 | * * |
| 255 | * |
Steven Rostedt | ef18012 | 2009-03-10 14:10:56 -0400 | [diff] [blame] | 256 | * TP_fast_assign( |
| 257 | * memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN); |
| 258 | * __entry->prev_pid = prev->pid; |
| 259 | * __entry->prev_prio = prev->prio; |
Steven Rostedt | 823f912 | 2009-03-10 12:58:51 -0400 | [diff] [blame] | 260 | * memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN); |
| 261 | * __entry->next_pid = next->pid; |
Steven Rostedt | ef18012 | 2009-03-10 14:10:56 -0400 | [diff] [blame] | 262 | * __entry->next_prio = next->prio; |
Steven Rostedt | 823f912 | 2009-03-10 12:58:51 -0400 | [diff] [blame] | 263 | * ) |
| 264 | * |
| 265 | * * |
| 266 | * * Formatted output of a trace record via TP_printk(). |
| 267 | * * This is how the tracepoint will appear under ftrace |
| 268 | * * plugins that make use of this tracepoint. |
| 269 | * * |
| 270 | * * (raw-binary tracing wont actually perform this step.) |
| 271 | * * |
| 272 | * |
| 273 | * TP_printk("task %s:%d [%d] ==> %s:%d [%d]", |
| 274 | * __entry->prev_comm, __entry->prev_pid, __entry->prev_prio, |
| 275 | * __entry->next_comm, __entry->next_pid, __entry->next_prio), |
| 276 | * |
| 277 | * ); |
| 278 | * |
| 279 | * This macro construct is thus used for the regular printk format |
| 280 | * tracing setup, it is used to construct a function pointer based |
| 281 | * tracepoint callback (this is used by programmatic plugins and |
| 282 | * can also by used by generic instrumentation like SystemTap), and |
| 283 | * it is also used to expose a structured trace record in |
GeunSik Lim | 156f5a7 | 2009-06-02 15:01:37 +0900 | [diff] [blame] | 284 | * /sys/kernel/debug/tracing/events/. |
Steven Rostedt | 823f912 | 2009-03-10 12:58:51 -0400 | [diff] [blame] | 285 | */ |
| 286 | |
Steven Rostedt | 30a8fec | 2009-03-10 12:41:38 -0400 | [diff] [blame] | 287 | #define TRACE_EVENT(name, proto, args, struct, assign, print) \ |
Steven Rostedt | da4d030 | 2009-03-09 17:14:30 -0400 | [diff] [blame] | 288 | DECLARE_TRACE(name, PARAMS(proto), PARAMS(args)) |
Steven Rostedt | ea20d92 | 2009-04-10 08:54:16 -0400 | [diff] [blame] | 289 | #endif |
Steven Rostedt | da4d030 | 2009-03-09 17:14:30 -0400 | [diff] [blame] | 290 | |
Mathieu Desnoyers | 97e1c18 | 2008-07-18 12:16:16 -0400 | [diff] [blame] | 291 | #endif |