Tom Zanussi | 85f2b08 | 2013-10-24 08:59:24 -0500 | [diff] [blame] | 1 | /* |
| 2 | * trace_events_trigger - trace event triggers |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License as published by |
| 6 | * the Free Software Foundation; either version 2 of the License, or |
| 7 | * (at your option) any later version. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public License |
| 15 | * along with this program; if not, write to the Free Software |
| 16 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 17 | * |
| 18 | * Copyright (C) 2013 Tom Zanussi <tom.zanussi@linux.intel.com> |
| 19 | */ |
| 20 | |
| 21 | #include <linux/module.h> |
| 22 | #include <linux/ctype.h> |
| 23 | #include <linux/mutex.h> |
| 24 | #include <linux/slab.h> |
| 25 | |
| 26 | #include "trace.h" |
| 27 | |
| 28 | static LIST_HEAD(trigger_commands); |
| 29 | static DEFINE_MUTEX(trigger_cmd_mutex); |
| 30 | |
Tom Zanussi | 2a2df32 | 2013-10-24 08:59:25 -0500 | [diff] [blame] | 31 | static void |
| 32 | trigger_data_free(struct event_trigger_data *data) |
| 33 | { |
Tom Zanussi | bac5fb9 | 2013-10-24 08:59:29 -0500 | [diff] [blame] | 34 | if (data->cmd_ops->set_filter) |
| 35 | data->cmd_ops->set_filter(NULL, data, NULL); |
| 36 | |
Tom Zanussi | 2a2df32 | 2013-10-24 08:59:25 -0500 | [diff] [blame] | 37 | synchronize_sched(); /* make sure current triggers exit before free */ |
| 38 | kfree(data); |
| 39 | } |
| 40 | |
Tom Zanussi | 85f2b08 | 2013-10-24 08:59:24 -0500 | [diff] [blame] | 41 | /** |
| 42 | * event_triggers_call - Call triggers associated with a trace event |
| 43 | * @file: The ftrace_event_file associated with the event |
Tom Zanussi | bac5fb9 | 2013-10-24 08:59:29 -0500 | [diff] [blame] | 44 | * @rec: The trace entry for the event, NULL for unconditional invocation |
Tom Zanussi | 85f2b08 | 2013-10-24 08:59:24 -0500 | [diff] [blame] | 45 | * |
| 46 | * For each trigger associated with an event, invoke the trigger |
Tom Zanussi | bac5fb9 | 2013-10-24 08:59:29 -0500 | [diff] [blame] | 47 | * function registered with the associated trigger command. If rec is |
| 48 | * non-NULL, it means that the trigger requires further processing and |
| 49 | * shouldn't be unconditionally invoked. If rec is non-NULL and the |
| 50 | * trigger has a filter associated with it, rec will checked against |
| 51 | * the filter and if the record matches the trigger will be invoked. |
| 52 | * If the trigger is a 'post_trigger', meaning it shouldn't be invoked |
| 53 | * in any case until the current event is written, the trigger |
| 54 | * function isn't invoked but the bit associated with the deferred |
| 55 | * trigger is set in the return value. |
| 56 | * |
| 57 | * Returns an enum event_trigger_type value containing a set bit for |
| 58 | * any trigger that should be deferred, ETT_NONE if nothing to defer. |
Tom Zanussi | 85f2b08 | 2013-10-24 08:59:24 -0500 | [diff] [blame] | 59 | * |
| 60 | * Called from tracepoint handlers (with rcu_read_lock_sched() held). |
| 61 | * |
| 62 | * Return: an enum event_trigger_type value containing a set bit for |
| 63 | * any trigger that should be deferred, ETT_NONE if nothing to defer. |
| 64 | */ |
Tom Zanussi | bac5fb9 | 2013-10-24 08:59:29 -0500 | [diff] [blame] | 65 | enum event_trigger_type |
| 66 | event_triggers_call(struct ftrace_event_file *file, void *rec) |
| 67 | { |
| 68 | struct event_trigger_data *data; |
| 69 | enum event_trigger_type tt = ETT_NONE; |
| 70 | |
| 71 | if (list_empty(&file->triggers)) |
| 72 | return tt; |
| 73 | |
| 74 | list_for_each_entry_rcu(data, &file->triggers, list) { |
| 75 | if (!rec) { |
| 76 | data->ops->func(data); |
| 77 | continue; |
| 78 | } |
| 79 | if (data->filter && !filter_match_preds(data->filter, rec)) |
| 80 | continue; |
| 81 | if (data->cmd_ops->post_trigger) { |
| 82 | tt |= data->cmd_ops->trigger_type; |
| 83 | continue; |
| 84 | } |
| 85 | data->ops->func(data); |
| 86 | } |
| 87 | return tt; |
| 88 | } |
| 89 | EXPORT_SYMBOL_GPL(event_triggers_call); |
| 90 | |
| 91 | /** |
| 92 | * event_triggers_post_call - Call 'post_triggers' for a trace event |
| 93 | * @file: The ftrace_event_file associated with the event |
| 94 | * @tt: enum event_trigger_type containing a set bit for each trigger to invoke |
| 95 | * |
| 96 | * For each trigger associated with an event, invoke the trigger |
| 97 | * function registered with the associated trigger command, if the |
| 98 | * corresponding bit is set in the tt enum passed into this function. |
| 99 | * See @event_triggers_call for details on how those bits are set. |
| 100 | * |
| 101 | * Called from tracepoint handlers (with rcu_read_lock_sched() held). |
| 102 | */ |
| 103 | void |
| 104 | event_triggers_post_call(struct ftrace_event_file *file, |
| 105 | enum event_trigger_type tt) |
Tom Zanussi | 85f2b08 | 2013-10-24 08:59:24 -0500 | [diff] [blame] | 106 | { |
| 107 | struct event_trigger_data *data; |
| 108 | |
Tom Zanussi | bac5fb9 | 2013-10-24 08:59:29 -0500 | [diff] [blame] | 109 | list_for_each_entry_rcu(data, &file->triggers, list) { |
| 110 | if (data->cmd_ops->trigger_type & tt) |
| 111 | data->ops->func(data); |
| 112 | } |
Tom Zanussi | 85f2b08 | 2013-10-24 08:59:24 -0500 | [diff] [blame] | 113 | } |
Tom Zanussi | bac5fb9 | 2013-10-24 08:59:29 -0500 | [diff] [blame] | 114 | EXPORT_SYMBOL_GPL(event_triggers_post_call); |
Tom Zanussi | 85f2b08 | 2013-10-24 08:59:24 -0500 | [diff] [blame] | 115 | |
| 116 | static void *trigger_next(struct seq_file *m, void *t, loff_t *pos) |
| 117 | { |
| 118 | struct ftrace_event_file *event_file = event_file_data(m->private); |
| 119 | |
| 120 | return seq_list_next(t, &event_file->triggers, pos); |
| 121 | } |
| 122 | |
| 123 | static void *trigger_start(struct seq_file *m, loff_t *pos) |
| 124 | { |
| 125 | struct ftrace_event_file *event_file; |
| 126 | |
| 127 | /* ->stop() is called even if ->start() fails */ |
| 128 | mutex_lock(&event_mutex); |
| 129 | event_file = event_file_data(m->private); |
| 130 | if (unlikely(!event_file)) |
| 131 | return ERR_PTR(-ENODEV); |
| 132 | |
| 133 | return seq_list_start(&event_file->triggers, *pos); |
| 134 | } |
| 135 | |
| 136 | static void trigger_stop(struct seq_file *m, void *t) |
| 137 | { |
| 138 | mutex_unlock(&event_mutex); |
| 139 | } |
| 140 | |
| 141 | static int trigger_show(struct seq_file *m, void *v) |
| 142 | { |
| 143 | struct event_trigger_data *data; |
| 144 | |
| 145 | data = list_entry(v, struct event_trigger_data, list); |
| 146 | data->ops->print(m, data->ops, data); |
| 147 | |
| 148 | return 0; |
| 149 | } |
| 150 | |
| 151 | static const struct seq_operations event_triggers_seq_ops = { |
| 152 | .start = trigger_start, |
| 153 | .next = trigger_next, |
| 154 | .stop = trigger_stop, |
| 155 | .show = trigger_show, |
| 156 | }; |
| 157 | |
| 158 | static int event_trigger_regex_open(struct inode *inode, struct file *file) |
| 159 | { |
| 160 | int ret = 0; |
| 161 | |
| 162 | mutex_lock(&event_mutex); |
| 163 | |
| 164 | if (unlikely(!event_file_data(file))) { |
| 165 | mutex_unlock(&event_mutex); |
| 166 | return -ENODEV; |
| 167 | } |
| 168 | |
| 169 | if (file->f_mode & FMODE_READ) { |
| 170 | ret = seq_open(file, &event_triggers_seq_ops); |
| 171 | if (!ret) { |
| 172 | struct seq_file *m = file->private_data; |
| 173 | m->private = file; |
| 174 | } |
| 175 | } |
| 176 | |
| 177 | mutex_unlock(&event_mutex); |
| 178 | |
| 179 | return ret; |
| 180 | } |
| 181 | |
| 182 | static int trigger_process_regex(struct ftrace_event_file *file, char *buff) |
| 183 | { |
| 184 | char *command, *next = buff; |
| 185 | struct event_command *p; |
| 186 | int ret = -EINVAL; |
| 187 | |
| 188 | command = strsep(&next, ": \t"); |
| 189 | command = (command[0] != '!') ? command : command + 1; |
| 190 | |
| 191 | mutex_lock(&trigger_cmd_mutex); |
| 192 | list_for_each_entry(p, &trigger_commands, list) { |
| 193 | if (strcmp(p->name, command) == 0) { |
| 194 | ret = p->func(p, file, buff, command, next); |
| 195 | goto out_unlock; |
| 196 | } |
| 197 | } |
| 198 | out_unlock: |
| 199 | mutex_unlock(&trigger_cmd_mutex); |
| 200 | |
| 201 | return ret; |
| 202 | } |
| 203 | |
| 204 | static ssize_t event_trigger_regex_write(struct file *file, |
| 205 | const char __user *ubuf, |
| 206 | size_t cnt, loff_t *ppos) |
| 207 | { |
| 208 | struct ftrace_event_file *event_file; |
| 209 | ssize_t ret; |
| 210 | char *buf; |
| 211 | |
| 212 | if (!cnt) |
| 213 | return 0; |
| 214 | |
| 215 | if (cnt >= PAGE_SIZE) |
| 216 | return -EINVAL; |
| 217 | |
| 218 | buf = (char *)__get_free_page(GFP_TEMPORARY); |
| 219 | if (!buf) |
| 220 | return -ENOMEM; |
| 221 | |
| 222 | if (copy_from_user(buf, ubuf, cnt)) { |
| 223 | free_page((unsigned long)buf); |
| 224 | return -EFAULT; |
| 225 | } |
| 226 | buf[cnt] = '\0'; |
| 227 | strim(buf); |
| 228 | |
| 229 | mutex_lock(&event_mutex); |
| 230 | event_file = event_file_data(file); |
| 231 | if (unlikely(!event_file)) { |
| 232 | mutex_unlock(&event_mutex); |
| 233 | free_page((unsigned long)buf); |
| 234 | return -ENODEV; |
| 235 | } |
| 236 | ret = trigger_process_regex(event_file, buf); |
| 237 | mutex_unlock(&event_mutex); |
| 238 | |
| 239 | free_page((unsigned long)buf); |
| 240 | if (ret < 0) |
| 241 | goto out; |
| 242 | |
| 243 | *ppos += cnt; |
| 244 | ret = cnt; |
| 245 | out: |
| 246 | return ret; |
| 247 | } |
| 248 | |
| 249 | static int event_trigger_regex_release(struct inode *inode, struct file *file) |
| 250 | { |
| 251 | mutex_lock(&event_mutex); |
| 252 | |
| 253 | if (file->f_mode & FMODE_READ) |
| 254 | seq_release(inode, file); |
| 255 | |
| 256 | mutex_unlock(&event_mutex); |
| 257 | |
| 258 | return 0; |
| 259 | } |
| 260 | |
| 261 | static ssize_t |
| 262 | event_trigger_write(struct file *filp, const char __user *ubuf, |
| 263 | size_t cnt, loff_t *ppos) |
| 264 | { |
| 265 | return event_trigger_regex_write(filp, ubuf, cnt, ppos); |
| 266 | } |
| 267 | |
| 268 | static int |
| 269 | event_trigger_open(struct inode *inode, struct file *filp) |
| 270 | { |
| 271 | return event_trigger_regex_open(inode, filp); |
| 272 | } |
| 273 | |
| 274 | static int |
| 275 | event_trigger_release(struct inode *inode, struct file *file) |
| 276 | { |
| 277 | return event_trigger_regex_release(inode, file); |
| 278 | } |
| 279 | |
| 280 | const struct file_operations event_trigger_fops = { |
| 281 | .open = event_trigger_open, |
| 282 | .read = seq_read, |
| 283 | .write = event_trigger_write, |
Steven Rostedt (Red Hat) | 098c879 | 2013-12-21 17:39:40 -0500 | [diff] [blame^] | 284 | .llseek = tracing_lseek, |
Tom Zanussi | 85f2b08 | 2013-10-24 08:59:24 -0500 | [diff] [blame] | 285 | .release = event_trigger_release, |
| 286 | }; |
| 287 | |
Tom Zanussi | 2a2df32 | 2013-10-24 08:59:25 -0500 | [diff] [blame] | 288 | /* |
| 289 | * Currently we only register event commands from __init, so mark this |
| 290 | * __init too. |
| 291 | */ |
| 292 | static __init int register_event_command(struct event_command *cmd) |
| 293 | { |
| 294 | struct event_command *p; |
| 295 | int ret = 0; |
| 296 | |
| 297 | mutex_lock(&trigger_cmd_mutex); |
| 298 | list_for_each_entry(p, &trigger_commands, list) { |
| 299 | if (strcmp(cmd->name, p->name) == 0) { |
| 300 | ret = -EBUSY; |
| 301 | goto out_unlock; |
| 302 | } |
| 303 | } |
| 304 | list_add(&cmd->list, &trigger_commands); |
| 305 | out_unlock: |
| 306 | mutex_unlock(&trigger_cmd_mutex); |
| 307 | |
| 308 | return ret; |
| 309 | } |
| 310 | |
| 311 | /* |
| 312 | * Currently we only unregister event commands from __init, so mark |
| 313 | * this __init too. |
| 314 | */ |
| 315 | static __init int unregister_event_command(struct event_command *cmd) |
| 316 | { |
| 317 | struct event_command *p, *n; |
| 318 | int ret = -ENODEV; |
| 319 | |
| 320 | mutex_lock(&trigger_cmd_mutex); |
| 321 | list_for_each_entry_safe(p, n, &trigger_commands, list) { |
| 322 | if (strcmp(cmd->name, p->name) == 0) { |
| 323 | ret = 0; |
| 324 | list_del_init(&p->list); |
| 325 | goto out_unlock; |
| 326 | } |
| 327 | } |
| 328 | out_unlock: |
| 329 | mutex_unlock(&trigger_cmd_mutex); |
| 330 | |
| 331 | return ret; |
| 332 | } |
| 333 | |
| 334 | /** |
| 335 | * event_trigger_print - Generic event_trigger_ops @print implementation |
| 336 | * @name: The name of the event trigger |
| 337 | * @m: The seq_file being printed to |
| 338 | * @data: Trigger-specific data |
| 339 | * @filter_str: filter_str to print, if present |
| 340 | * |
| 341 | * Common implementation for event triggers to print themselves. |
| 342 | * |
| 343 | * Usually wrapped by a function that simply sets the @name of the |
| 344 | * trigger command and then invokes this. |
| 345 | * |
| 346 | * Return: 0 on success, errno otherwise |
| 347 | */ |
| 348 | static int |
| 349 | event_trigger_print(const char *name, struct seq_file *m, |
| 350 | void *data, char *filter_str) |
| 351 | { |
| 352 | long count = (long)data; |
| 353 | |
| 354 | seq_printf(m, "%s", name); |
| 355 | |
| 356 | if (count == -1) |
| 357 | seq_puts(m, ":unlimited"); |
| 358 | else |
| 359 | seq_printf(m, ":count=%ld", count); |
| 360 | |
| 361 | if (filter_str) |
| 362 | seq_printf(m, " if %s\n", filter_str); |
| 363 | else |
| 364 | seq_puts(m, "\n"); |
| 365 | |
| 366 | return 0; |
| 367 | } |
| 368 | |
| 369 | /** |
| 370 | * event_trigger_init - Generic event_trigger_ops @init implementation |
| 371 | * @ops: The trigger ops associated with the trigger |
| 372 | * @data: Trigger-specific data |
| 373 | * |
| 374 | * Common implementation of event trigger initialization. |
| 375 | * |
| 376 | * Usually used directly as the @init method in event trigger |
| 377 | * implementations. |
| 378 | * |
| 379 | * Return: 0 on success, errno otherwise |
| 380 | */ |
| 381 | static int |
| 382 | event_trigger_init(struct event_trigger_ops *ops, |
| 383 | struct event_trigger_data *data) |
| 384 | { |
| 385 | data->ref++; |
| 386 | return 0; |
| 387 | } |
| 388 | |
| 389 | /** |
| 390 | * event_trigger_free - Generic event_trigger_ops @free implementation |
| 391 | * @ops: The trigger ops associated with the trigger |
| 392 | * @data: Trigger-specific data |
| 393 | * |
| 394 | * Common implementation of event trigger de-initialization. |
| 395 | * |
| 396 | * Usually used directly as the @free method in event trigger |
| 397 | * implementations. |
| 398 | */ |
| 399 | static void |
| 400 | event_trigger_free(struct event_trigger_ops *ops, |
| 401 | struct event_trigger_data *data) |
| 402 | { |
| 403 | if (WARN_ON_ONCE(data->ref <= 0)) |
| 404 | return; |
| 405 | |
| 406 | data->ref--; |
| 407 | if (!data->ref) |
| 408 | trigger_data_free(data); |
| 409 | } |
| 410 | |
Tom Zanussi | 85f2b08 | 2013-10-24 08:59:24 -0500 | [diff] [blame] | 411 | static int trace_event_trigger_enable_disable(struct ftrace_event_file *file, |
| 412 | int trigger_enable) |
| 413 | { |
| 414 | int ret = 0; |
| 415 | |
| 416 | if (trigger_enable) { |
| 417 | if (atomic_inc_return(&file->tm_ref) > 1) |
| 418 | return ret; |
| 419 | set_bit(FTRACE_EVENT_FL_TRIGGER_MODE_BIT, &file->flags); |
| 420 | ret = trace_event_enable_disable(file, 1, 1); |
| 421 | } else { |
| 422 | if (atomic_dec_return(&file->tm_ref) > 0) |
| 423 | return ret; |
| 424 | clear_bit(FTRACE_EVENT_FL_TRIGGER_MODE_BIT, &file->flags); |
| 425 | ret = trace_event_enable_disable(file, 0, 1); |
| 426 | } |
| 427 | |
| 428 | return ret; |
| 429 | } |
| 430 | |
| 431 | /** |
| 432 | * clear_event_triggers - Clear all triggers associated with a trace array |
| 433 | * @tr: The trace array to clear |
| 434 | * |
| 435 | * For each trigger, the triggering event has its tm_ref decremented |
| 436 | * via trace_event_trigger_enable_disable(), and any associated event |
| 437 | * (in the case of enable/disable_event triggers) will have its sm_ref |
| 438 | * decremented via free()->trace_event_enable_disable(). That |
| 439 | * combination effectively reverses the soft-mode/trigger state added |
| 440 | * by trigger registration. |
| 441 | * |
| 442 | * Must be called with event_mutex held. |
| 443 | */ |
| 444 | void |
| 445 | clear_event_triggers(struct trace_array *tr) |
| 446 | { |
| 447 | struct ftrace_event_file *file; |
| 448 | |
| 449 | list_for_each_entry(file, &tr->events, list) { |
| 450 | struct event_trigger_data *data; |
| 451 | list_for_each_entry_rcu(data, &file->triggers, list) { |
| 452 | trace_event_trigger_enable_disable(file, 0); |
| 453 | if (data->ops->free) |
| 454 | data->ops->free(data->ops, data); |
| 455 | } |
| 456 | } |
| 457 | } |
| 458 | |
Tom Zanussi | 2a2df32 | 2013-10-24 08:59:25 -0500 | [diff] [blame] | 459 | /** |
Tom Zanussi | bac5fb9 | 2013-10-24 08:59:29 -0500 | [diff] [blame] | 460 | * update_cond_flag - Set or reset the TRIGGER_COND bit |
| 461 | * @file: The ftrace_event_file associated with the event |
| 462 | * |
| 463 | * If an event has triggers and any of those triggers has a filter or |
| 464 | * a post_trigger, trigger invocation needs to be deferred until after |
| 465 | * the current event has logged its data, and the event should have |
| 466 | * its TRIGGER_COND bit set, otherwise the TRIGGER_COND bit should be |
| 467 | * cleared. |
| 468 | */ |
| 469 | static void update_cond_flag(struct ftrace_event_file *file) |
| 470 | { |
| 471 | struct event_trigger_data *data; |
| 472 | bool set_cond = false; |
| 473 | |
| 474 | list_for_each_entry_rcu(data, &file->triggers, list) { |
| 475 | if (data->filter || data->cmd_ops->post_trigger) { |
| 476 | set_cond = true; |
| 477 | break; |
| 478 | } |
| 479 | } |
| 480 | |
| 481 | if (set_cond) |
| 482 | set_bit(FTRACE_EVENT_FL_TRIGGER_COND_BIT, &file->flags); |
| 483 | else |
| 484 | clear_bit(FTRACE_EVENT_FL_TRIGGER_COND_BIT, &file->flags); |
| 485 | } |
| 486 | |
| 487 | /** |
Tom Zanussi | 2a2df32 | 2013-10-24 08:59:25 -0500 | [diff] [blame] | 488 | * register_trigger - Generic event_command @reg implementation |
| 489 | * @glob: The raw string used to register the trigger |
| 490 | * @ops: The trigger ops associated with the trigger |
| 491 | * @data: Trigger-specific data to associate with the trigger |
| 492 | * @file: The ftrace_event_file associated with the event |
| 493 | * |
| 494 | * Common implementation for event trigger registration. |
| 495 | * |
| 496 | * Usually used directly as the @reg method in event command |
| 497 | * implementations. |
| 498 | * |
| 499 | * Return: 0 on success, errno otherwise |
| 500 | */ |
| 501 | static int register_trigger(char *glob, struct event_trigger_ops *ops, |
| 502 | struct event_trigger_data *data, |
| 503 | struct ftrace_event_file *file) |
| 504 | { |
| 505 | struct event_trigger_data *test; |
| 506 | int ret = 0; |
| 507 | |
| 508 | list_for_each_entry_rcu(test, &file->triggers, list) { |
| 509 | if (test->cmd_ops->trigger_type == data->cmd_ops->trigger_type) { |
| 510 | ret = -EEXIST; |
| 511 | goto out; |
| 512 | } |
| 513 | } |
| 514 | |
| 515 | if (data->ops->init) { |
| 516 | ret = data->ops->init(data->ops, data); |
| 517 | if (ret < 0) |
| 518 | goto out; |
| 519 | } |
| 520 | |
| 521 | list_add_rcu(&data->list, &file->triggers); |
| 522 | ret++; |
| 523 | |
| 524 | if (trace_event_trigger_enable_disable(file, 1) < 0) { |
| 525 | list_del_rcu(&data->list); |
| 526 | ret--; |
| 527 | } |
Tom Zanussi | bac5fb9 | 2013-10-24 08:59:29 -0500 | [diff] [blame] | 528 | update_cond_flag(file); |
Tom Zanussi | 2a2df32 | 2013-10-24 08:59:25 -0500 | [diff] [blame] | 529 | out: |
| 530 | return ret; |
| 531 | } |
| 532 | |
| 533 | /** |
| 534 | * unregister_trigger - Generic event_command @unreg implementation |
| 535 | * @glob: The raw string used to register the trigger |
| 536 | * @ops: The trigger ops associated with the trigger |
| 537 | * @test: Trigger-specific data used to find the trigger to remove |
| 538 | * @file: The ftrace_event_file associated with the event |
| 539 | * |
| 540 | * Common implementation for event trigger unregistration. |
| 541 | * |
| 542 | * Usually used directly as the @unreg method in event command |
| 543 | * implementations. |
| 544 | */ |
| 545 | static void unregister_trigger(char *glob, struct event_trigger_ops *ops, |
| 546 | struct event_trigger_data *test, |
| 547 | struct ftrace_event_file *file) |
| 548 | { |
| 549 | struct event_trigger_data *data; |
| 550 | bool unregistered = false; |
| 551 | |
| 552 | list_for_each_entry_rcu(data, &file->triggers, list) { |
| 553 | if (data->cmd_ops->trigger_type == test->cmd_ops->trigger_type) { |
| 554 | unregistered = true; |
| 555 | list_del_rcu(&data->list); |
Tom Zanussi | bac5fb9 | 2013-10-24 08:59:29 -0500 | [diff] [blame] | 556 | update_cond_flag(file); |
Tom Zanussi | 2a2df32 | 2013-10-24 08:59:25 -0500 | [diff] [blame] | 557 | trace_event_trigger_enable_disable(file, 0); |
| 558 | break; |
| 559 | } |
| 560 | } |
| 561 | |
| 562 | if (unregistered && data->ops->free) |
| 563 | data->ops->free(data->ops, data); |
| 564 | } |
| 565 | |
| 566 | /** |
| 567 | * event_trigger_callback - Generic event_command @func implementation |
| 568 | * @cmd_ops: The command ops, used for trigger registration |
| 569 | * @file: The ftrace_event_file associated with the event |
| 570 | * @glob: The raw string used to register the trigger |
| 571 | * @cmd: The cmd portion of the string used to register the trigger |
| 572 | * @param: The params portion of the string used to register the trigger |
| 573 | * |
| 574 | * Common implementation for event command parsing and trigger |
| 575 | * instantiation. |
| 576 | * |
| 577 | * Usually used directly as the @func method in event command |
| 578 | * implementations. |
| 579 | * |
| 580 | * Return: 0 on success, errno otherwise |
| 581 | */ |
| 582 | static int |
| 583 | event_trigger_callback(struct event_command *cmd_ops, |
| 584 | struct ftrace_event_file *file, |
| 585 | char *glob, char *cmd, char *param) |
| 586 | { |
| 587 | struct event_trigger_data *trigger_data; |
| 588 | struct event_trigger_ops *trigger_ops; |
| 589 | char *trigger = NULL; |
| 590 | char *number; |
| 591 | int ret; |
| 592 | |
| 593 | /* separate the trigger from the filter (t:n [if filter]) */ |
| 594 | if (param && isdigit(param[0])) |
| 595 | trigger = strsep(¶m, " \t"); |
| 596 | |
| 597 | trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger); |
| 598 | |
| 599 | ret = -ENOMEM; |
| 600 | trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL); |
| 601 | if (!trigger_data) |
| 602 | goto out; |
| 603 | |
| 604 | trigger_data->count = -1; |
| 605 | trigger_data->ops = trigger_ops; |
| 606 | trigger_data->cmd_ops = cmd_ops; |
| 607 | INIT_LIST_HEAD(&trigger_data->list); |
| 608 | |
| 609 | if (glob[0] == '!') { |
| 610 | cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file); |
| 611 | kfree(trigger_data); |
| 612 | ret = 0; |
| 613 | goto out; |
| 614 | } |
| 615 | |
| 616 | if (trigger) { |
| 617 | number = strsep(&trigger, ":"); |
| 618 | |
| 619 | ret = -EINVAL; |
| 620 | if (!strlen(number)) |
| 621 | goto out_free; |
| 622 | |
| 623 | /* |
| 624 | * We use the callback data field (which is a pointer) |
| 625 | * as our counter. |
| 626 | */ |
| 627 | ret = kstrtoul(number, 0, &trigger_data->count); |
| 628 | if (ret) |
| 629 | goto out_free; |
| 630 | } |
| 631 | |
| 632 | if (!param) /* if param is non-empty, it's supposed to be a filter */ |
| 633 | goto out_reg; |
| 634 | |
| 635 | if (!cmd_ops->set_filter) |
| 636 | goto out_reg; |
| 637 | |
| 638 | ret = cmd_ops->set_filter(param, trigger_data, file); |
| 639 | if (ret < 0) |
| 640 | goto out_free; |
| 641 | |
| 642 | out_reg: |
| 643 | ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file); |
| 644 | /* |
| 645 | * The above returns on success the # of functions enabled, |
| 646 | * but if it didn't find any functions it returns zero. |
| 647 | * Consider no functions a failure too. |
| 648 | */ |
| 649 | if (!ret) { |
| 650 | ret = -ENOENT; |
| 651 | goto out_free; |
| 652 | } else if (ret < 0) |
| 653 | goto out_free; |
| 654 | ret = 0; |
| 655 | out: |
| 656 | return ret; |
| 657 | |
| 658 | out_free: |
Tom Zanussi | bac5fb9 | 2013-10-24 08:59:29 -0500 | [diff] [blame] | 659 | if (cmd_ops->set_filter) |
| 660 | cmd_ops->set_filter(NULL, trigger_data, NULL); |
Tom Zanussi | 2a2df32 | 2013-10-24 08:59:25 -0500 | [diff] [blame] | 661 | kfree(trigger_data); |
| 662 | goto out; |
| 663 | } |
| 664 | |
Tom Zanussi | bac5fb9 | 2013-10-24 08:59:29 -0500 | [diff] [blame] | 665 | /** |
| 666 | * set_trigger_filter - Generic event_command @set_filter implementation |
| 667 | * @filter_str: The filter string for the trigger, NULL to remove filter |
| 668 | * @trigger_data: Trigger-specific data |
| 669 | * @file: The ftrace_event_file associated with the event |
| 670 | * |
| 671 | * Common implementation for event command filter parsing and filter |
| 672 | * instantiation. |
| 673 | * |
| 674 | * Usually used directly as the @set_filter method in event command |
| 675 | * implementations. |
| 676 | * |
| 677 | * Also used to remove a filter (if filter_str = NULL). |
| 678 | * |
| 679 | * Return: 0 on success, errno otherwise |
| 680 | */ |
| 681 | static int set_trigger_filter(char *filter_str, |
| 682 | struct event_trigger_data *trigger_data, |
| 683 | struct ftrace_event_file *file) |
| 684 | { |
| 685 | struct event_trigger_data *data = trigger_data; |
| 686 | struct event_filter *filter = NULL, *tmp; |
| 687 | int ret = -EINVAL; |
| 688 | char *s; |
| 689 | |
| 690 | if (!filter_str) /* clear the current filter */ |
| 691 | goto assign; |
| 692 | |
| 693 | s = strsep(&filter_str, " \t"); |
| 694 | |
| 695 | if (!strlen(s) || strcmp(s, "if") != 0) |
| 696 | goto out; |
| 697 | |
| 698 | if (!filter_str) |
| 699 | goto out; |
| 700 | |
| 701 | /* The filter is for the 'trigger' event, not the triggered event */ |
| 702 | ret = create_event_filter(file->event_call, filter_str, false, &filter); |
| 703 | if (ret) |
| 704 | goto out; |
| 705 | assign: |
| 706 | tmp = data->filter; |
| 707 | |
| 708 | rcu_assign_pointer(data->filter, filter); |
| 709 | |
| 710 | if (tmp) { |
| 711 | /* Make sure the call is done with the filter */ |
| 712 | synchronize_sched(); |
| 713 | free_event_filter(tmp); |
| 714 | } |
| 715 | |
| 716 | kfree(data->filter_str); |
| 717 | data->filter_str = NULL; |
| 718 | |
| 719 | if (filter_str) { |
| 720 | data->filter_str = kstrdup(filter_str, GFP_KERNEL); |
| 721 | if (!data->filter_str) { |
| 722 | free_event_filter(data->filter); |
| 723 | data->filter = NULL; |
| 724 | ret = -ENOMEM; |
| 725 | } |
| 726 | } |
| 727 | out: |
| 728 | return ret; |
| 729 | } |
| 730 | |
Tom Zanussi | 2a2df32 | 2013-10-24 08:59:25 -0500 | [diff] [blame] | 731 | static void |
| 732 | traceon_trigger(struct event_trigger_data *data) |
| 733 | { |
| 734 | if (tracing_is_on()) |
| 735 | return; |
| 736 | |
| 737 | tracing_on(); |
| 738 | } |
| 739 | |
| 740 | static void |
| 741 | traceon_count_trigger(struct event_trigger_data *data) |
| 742 | { |
| 743 | if (!data->count) |
| 744 | return; |
| 745 | |
| 746 | if (data->count != -1) |
| 747 | (data->count)--; |
| 748 | |
| 749 | traceon_trigger(data); |
| 750 | } |
| 751 | |
| 752 | static void |
| 753 | traceoff_trigger(struct event_trigger_data *data) |
| 754 | { |
| 755 | if (!tracing_is_on()) |
| 756 | return; |
| 757 | |
| 758 | tracing_off(); |
| 759 | } |
| 760 | |
| 761 | static void |
| 762 | traceoff_count_trigger(struct event_trigger_data *data) |
| 763 | { |
| 764 | if (!data->count) |
| 765 | return; |
| 766 | |
| 767 | if (data->count != -1) |
| 768 | (data->count)--; |
| 769 | |
| 770 | traceoff_trigger(data); |
| 771 | } |
| 772 | |
| 773 | static int |
| 774 | traceon_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, |
| 775 | struct event_trigger_data *data) |
| 776 | { |
| 777 | return event_trigger_print("traceon", m, (void *)data->count, |
| 778 | data->filter_str); |
| 779 | } |
| 780 | |
| 781 | static int |
| 782 | traceoff_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, |
| 783 | struct event_trigger_data *data) |
| 784 | { |
| 785 | return event_trigger_print("traceoff", m, (void *)data->count, |
| 786 | data->filter_str); |
| 787 | } |
| 788 | |
| 789 | static struct event_trigger_ops traceon_trigger_ops = { |
| 790 | .func = traceon_trigger, |
| 791 | .print = traceon_trigger_print, |
| 792 | .init = event_trigger_init, |
| 793 | .free = event_trigger_free, |
| 794 | }; |
| 795 | |
| 796 | static struct event_trigger_ops traceon_count_trigger_ops = { |
| 797 | .func = traceon_count_trigger, |
| 798 | .print = traceon_trigger_print, |
| 799 | .init = event_trigger_init, |
| 800 | .free = event_trigger_free, |
| 801 | }; |
| 802 | |
| 803 | static struct event_trigger_ops traceoff_trigger_ops = { |
| 804 | .func = traceoff_trigger, |
| 805 | .print = traceoff_trigger_print, |
| 806 | .init = event_trigger_init, |
| 807 | .free = event_trigger_free, |
| 808 | }; |
| 809 | |
| 810 | static struct event_trigger_ops traceoff_count_trigger_ops = { |
| 811 | .func = traceoff_count_trigger, |
| 812 | .print = traceoff_trigger_print, |
| 813 | .init = event_trigger_init, |
| 814 | .free = event_trigger_free, |
| 815 | }; |
| 816 | |
| 817 | static struct event_trigger_ops * |
| 818 | onoff_get_trigger_ops(char *cmd, char *param) |
| 819 | { |
| 820 | struct event_trigger_ops *ops; |
| 821 | |
| 822 | /* we register both traceon and traceoff to this callback */ |
| 823 | if (strcmp(cmd, "traceon") == 0) |
| 824 | ops = param ? &traceon_count_trigger_ops : |
| 825 | &traceon_trigger_ops; |
| 826 | else |
| 827 | ops = param ? &traceoff_count_trigger_ops : |
| 828 | &traceoff_trigger_ops; |
| 829 | |
| 830 | return ops; |
| 831 | } |
| 832 | |
| 833 | static struct event_command trigger_traceon_cmd = { |
| 834 | .name = "traceon", |
| 835 | .trigger_type = ETT_TRACE_ONOFF, |
| 836 | .func = event_trigger_callback, |
| 837 | .reg = register_trigger, |
| 838 | .unreg = unregister_trigger, |
| 839 | .get_trigger_ops = onoff_get_trigger_ops, |
Tom Zanussi | bac5fb9 | 2013-10-24 08:59:29 -0500 | [diff] [blame] | 840 | .set_filter = set_trigger_filter, |
Tom Zanussi | 2a2df32 | 2013-10-24 08:59:25 -0500 | [diff] [blame] | 841 | }; |
| 842 | |
| 843 | static struct event_command trigger_traceoff_cmd = { |
| 844 | .name = "traceoff", |
| 845 | .trigger_type = ETT_TRACE_ONOFF, |
| 846 | .func = event_trigger_callback, |
| 847 | .reg = register_trigger, |
| 848 | .unreg = unregister_trigger, |
| 849 | .get_trigger_ops = onoff_get_trigger_ops, |
Tom Zanussi | bac5fb9 | 2013-10-24 08:59:29 -0500 | [diff] [blame] | 850 | .set_filter = set_trigger_filter, |
Tom Zanussi | 2a2df32 | 2013-10-24 08:59:25 -0500 | [diff] [blame] | 851 | }; |
| 852 | |
Tom Zanussi | 93e31ff | 2013-10-24 08:59:26 -0500 | [diff] [blame] | 853 | #ifdef CONFIG_TRACER_SNAPSHOT |
| 854 | static void |
| 855 | snapshot_trigger(struct event_trigger_data *data) |
| 856 | { |
| 857 | tracing_snapshot(); |
| 858 | } |
| 859 | |
| 860 | static void |
| 861 | snapshot_count_trigger(struct event_trigger_data *data) |
| 862 | { |
| 863 | if (!data->count) |
| 864 | return; |
| 865 | |
| 866 | if (data->count != -1) |
| 867 | (data->count)--; |
| 868 | |
| 869 | snapshot_trigger(data); |
| 870 | } |
| 871 | |
| 872 | static int |
| 873 | register_snapshot_trigger(char *glob, struct event_trigger_ops *ops, |
| 874 | struct event_trigger_data *data, |
| 875 | struct ftrace_event_file *file) |
| 876 | { |
| 877 | int ret = register_trigger(glob, ops, data, file); |
| 878 | |
| 879 | if (ret > 0 && tracing_alloc_snapshot() != 0) { |
| 880 | unregister_trigger(glob, ops, data, file); |
| 881 | ret = 0; |
| 882 | } |
| 883 | |
| 884 | return ret; |
| 885 | } |
| 886 | |
| 887 | static int |
| 888 | snapshot_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, |
| 889 | struct event_trigger_data *data) |
| 890 | { |
| 891 | return event_trigger_print("snapshot", m, (void *)data->count, |
| 892 | data->filter_str); |
| 893 | } |
| 894 | |
| 895 | static struct event_trigger_ops snapshot_trigger_ops = { |
| 896 | .func = snapshot_trigger, |
| 897 | .print = snapshot_trigger_print, |
| 898 | .init = event_trigger_init, |
| 899 | .free = event_trigger_free, |
| 900 | }; |
| 901 | |
| 902 | static struct event_trigger_ops snapshot_count_trigger_ops = { |
| 903 | .func = snapshot_count_trigger, |
| 904 | .print = snapshot_trigger_print, |
| 905 | .init = event_trigger_init, |
| 906 | .free = event_trigger_free, |
| 907 | }; |
| 908 | |
| 909 | static struct event_trigger_ops * |
| 910 | snapshot_get_trigger_ops(char *cmd, char *param) |
| 911 | { |
| 912 | return param ? &snapshot_count_trigger_ops : &snapshot_trigger_ops; |
| 913 | } |
| 914 | |
| 915 | static struct event_command trigger_snapshot_cmd = { |
| 916 | .name = "snapshot", |
| 917 | .trigger_type = ETT_SNAPSHOT, |
| 918 | .func = event_trigger_callback, |
| 919 | .reg = register_snapshot_trigger, |
| 920 | .unreg = unregister_trigger, |
| 921 | .get_trigger_ops = snapshot_get_trigger_ops, |
Tom Zanussi | bac5fb9 | 2013-10-24 08:59:29 -0500 | [diff] [blame] | 922 | .set_filter = set_trigger_filter, |
Tom Zanussi | 93e31ff | 2013-10-24 08:59:26 -0500 | [diff] [blame] | 923 | }; |
| 924 | |
| 925 | static __init int register_trigger_snapshot_cmd(void) |
| 926 | { |
| 927 | int ret; |
| 928 | |
| 929 | ret = register_event_command(&trigger_snapshot_cmd); |
| 930 | WARN_ON(ret < 0); |
| 931 | |
| 932 | return ret; |
| 933 | } |
| 934 | #else |
| 935 | static __init int register_trigger_snapshot_cmd(void) { return 0; } |
| 936 | #endif /* CONFIG_TRACER_SNAPSHOT */ |
| 937 | |
Tom Zanussi | f21ecbb | 2013-10-24 08:59:27 -0500 | [diff] [blame] | 938 | #ifdef CONFIG_STACKTRACE |
| 939 | /* |
| 940 | * Skip 3: |
| 941 | * stacktrace_trigger() |
| 942 | * event_triggers_post_call() |
| 943 | * ftrace_raw_event_xxx() |
| 944 | */ |
| 945 | #define STACK_SKIP 3 |
| 946 | |
| 947 | static void |
| 948 | stacktrace_trigger(struct event_trigger_data *data) |
| 949 | { |
| 950 | trace_dump_stack(STACK_SKIP); |
| 951 | } |
| 952 | |
| 953 | static void |
| 954 | stacktrace_count_trigger(struct event_trigger_data *data) |
| 955 | { |
| 956 | if (!data->count) |
| 957 | return; |
| 958 | |
| 959 | if (data->count != -1) |
| 960 | (data->count)--; |
| 961 | |
| 962 | stacktrace_trigger(data); |
| 963 | } |
| 964 | |
| 965 | static int |
| 966 | stacktrace_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, |
| 967 | struct event_trigger_data *data) |
| 968 | { |
| 969 | return event_trigger_print("stacktrace", m, (void *)data->count, |
| 970 | data->filter_str); |
| 971 | } |
| 972 | |
| 973 | static struct event_trigger_ops stacktrace_trigger_ops = { |
| 974 | .func = stacktrace_trigger, |
| 975 | .print = stacktrace_trigger_print, |
| 976 | .init = event_trigger_init, |
| 977 | .free = event_trigger_free, |
| 978 | }; |
| 979 | |
| 980 | static struct event_trigger_ops stacktrace_count_trigger_ops = { |
| 981 | .func = stacktrace_count_trigger, |
| 982 | .print = stacktrace_trigger_print, |
| 983 | .init = event_trigger_init, |
| 984 | .free = event_trigger_free, |
| 985 | }; |
| 986 | |
| 987 | static struct event_trigger_ops * |
| 988 | stacktrace_get_trigger_ops(char *cmd, char *param) |
| 989 | { |
| 990 | return param ? &stacktrace_count_trigger_ops : &stacktrace_trigger_ops; |
| 991 | } |
| 992 | |
| 993 | static struct event_command trigger_stacktrace_cmd = { |
| 994 | .name = "stacktrace", |
| 995 | .trigger_type = ETT_STACKTRACE, |
| 996 | .post_trigger = true, |
| 997 | .func = event_trigger_callback, |
| 998 | .reg = register_trigger, |
| 999 | .unreg = unregister_trigger, |
| 1000 | .get_trigger_ops = stacktrace_get_trigger_ops, |
Tom Zanussi | bac5fb9 | 2013-10-24 08:59:29 -0500 | [diff] [blame] | 1001 | .set_filter = set_trigger_filter, |
Tom Zanussi | f21ecbb | 2013-10-24 08:59:27 -0500 | [diff] [blame] | 1002 | }; |
| 1003 | |
| 1004 | static __init int register_trigger_stacktrace_cmd(void) |
| 1005 | { |
| 1006 | int ret; |
| 1007 | |
| 1008 | ret = register_event_command(&trigger_stacktrace_cmd); |
| 1009 | WARN_ON(ret < 0); |
| 1010 | |
| 1011 | return ret; |
| 1012 | } |
| 1013 | #else |
| 1014 | static __init int register_trigger_stacktrace_cmd(void) { return 0; } |
| 1015 | #endif /* CONFIG_STACKTRACE */ |
| 1016 | |
Tom Zanussi | 2a2df32 | 2013-10-24 08:59:25 -0500 | [diff] [blame] | 1017 | static __init void unregister_trigger_traceon_traceoff_cmds(void) |
| 1018 | { |
| 1019 | unregister_event_command(&trigger_traceon_cmd); |
| 1020 | unregister_event_command(&trigger_traceoff_cmd); |
| 1021 | } |
| 1022 | |
Tom Zanussi | 7862ad1 | 2013-10-24 08:59:28 -0500 | [diff] [blame] | 1023 | /* Avoid typos */ |
| 1024 | #define ENABLE_EVENT_STR "enable_event" |
| 1025 | #define DISABLE_EVENT_STR "disable_event" |
| 1026 | |
| 1027 | struct enable_trigger_data { |
| 1028 | struct ftrace_event_file *file; |
| 1029 | bool enable; |
| 1030 | }; |
| 1031 | |
| 1032 | static void |
| 1033 | event_enable_trigger(struct event_trigger_data *data) |
| 1034 | { |
| 1035 | struct enable_trigger_data *enable_data = data->private_data; |
| 1036 | |
| 1037 | if (enable_data->enable) |
| 1038 | clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &enable_data->file->flags); |
| 1039 | else |
| 1040 | set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &enable_data->file->flags); |
| 1041 | } |
| 1042 | |
| 1043 | static void |
| 1044 | event_enable_count_trigger(struct event_trigger_data *data) |
| 1045 | { |
| 1046 | struct enable_trigger_data *enable_data = data->private_data; |
| 1047 | |
| 1048 | if (!data->count) |
| 1049 | return; |
| 1050 | |
| 1051 | /* Skip if the event is in a state we want to switch to */ |
| 1052 | if (enable_data->enable == !(enable_data->file->flags & FTRACE_EVENT_FL_SOFT_DISABLED)) |
| 1053 | return; |
| 1054 | |
| 1055 | if (data->count != -1) |
| 1056 | (data->count)--; |
| 1057 | |
| 1058 | event_enable_trigger(data); |
| 1059 | } |
| 1060 | |
| 1061 | static int |
| 1062 | event_enable_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, |
| 1063 | struct event_trigger_data *data) |
| 1064 | { |
| 1065 | struct enable_trigger_data *enable_data = data->private_data; |
| 1066 | |
| 1067 | seq_printf(m, "%s:%s:%s", |
| 1068 | enable_data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR, |
| 1069 | enable_data->file->event_call->class->system, |
| 1070 | enable_data->file->event_call->name); |
| 1071 | |
| 1072 | if (data->count == -1) |
| 1073 | seq_puts(m, ":unlimited"); |
| 1074 | else |
| 1075 | seq_printf(m, ":count=%ld", data->count); |
| 1076 | |
| 1077 | if (data->filter_str) |
| 1078 | seq_printf(m, " if %s\n", data->filter_str); |
| 1079 | else |
| 1080 | seq_puts(m, "\n"); |
| 1081 | |
| 1082 | return 0; |
| 1083 | } |
| 1084 | |
| 1085 | static void |
| 1086 | event_enable_trigger_free(struct event_trigger_ops *ops, |
| 1087 | struct event_trigger_data *data) |
| 1088 | { |
| 1089 | struct enable_trigger_data *enable_data = data->private_data; |
| 1090 | |
| 1091 | if (WARN_ON_ONCE(data->ref <= 0)) |
| 1092 | return; |
| 1093 | |
| 1094 | data->ref--; |
| 1095 | if (!data->ref) { |
| 1096 | /* Remove the SOFT_MODE flag */ |
| 1097 | trace_event_enable_disable(enable_data->file, 0, 1); |
| 1098 | module_put(enable_data->file->event_call->mod); |
| 1099 | trigger_data_free(data); |
| 1100 | kfree(enable_data); |
| 1101 | } |
| 1102 | } |
| 1103 | |
| 1104 | static struct event_trigger_ops event_enable_trigger_ops = { |
| 1105 | .func = event_enable_trigger, |
| 1106 | .print = event_enable_trigger_print, |
| 1107 | .init = event_trigger_init, |
| 1108 | .free = event_enable_trigger_free, |
| 1109 | }; |
| 1110 | |
| 1111 | static struct event_trigger_ops event_enable_count_trigger_ops = { |
| 1112 | .func = event_enable_count_trigger, |
| 1113 | .print = event_enable_trigger_print, |
| 1114 | .init = event_trigger_init, |
| 1115 | .free = event_enable_trigger_free, |
| 1116 | }; |
| 1117 | |
| 1118 | static struct event_trigger_ops event_disable_trigger_ops = { |
| 1119 | .func = event_enable_trigger, |
| 1120 | .print = event_enable_trigger_print, |
| 1121 | .init = event_trigger_init, |
| 1122 | .free = event_enable_trigger_free, |
| 1123 | }; |
| 1124 | |
| 1125 | static struct event_trigger_ops event_disable_count_trigger_ops = { |
| 1126 | .func = event_enable_count_trigger, |
| 1127 | .print = event_enable_trigger_print, |
| 1128 | .init = event_trigger_init, |
| 1129 | .free = event_enable_trigger_free, |
| 1130 | }; |
| 1131 | |
| 1132 | static int |
| 1133 | event_enable_trigger_func(struct event_command *cmd_ops, |
| 1134 | struct ftrace_event_file *file, |
| 1135 | char *glob, char *cmd, char *param) |
| 1136 | { |
| 1137 | struct ftrace_event_file *event_enable_file; |
| 1138 | struct enable_trigger_data *enable_data; |
| 1139 | struct event_trigger_data *trigger_data; |
| 1140 | struct event_trigger_ops *trigger_ops; |
| 1141 | struct trace_array *tr = file->tr; |
| 1142 | const char *system; |
| 1143 | const char *event; |
| 1144 | char *trigger; |
| 1145 | char *number; |
| 1146 | bool enable; |
| 1147 | int ret; |
| 1148 | |
| 1149 | if (!param) |
| 1150 | return -EINVAL; |
| 1151 | |
| 1152 | /* separate the trigger from the filter (s:e:n [if filter]) */ |
| 1153 | trigger = strsep(¶m, " \t"); |
| 1154 | if (!trigger) |
| 1155 | return -EINVAL; |
| 1156 | |
| 1157 | system = strsep(&trigger, ":"); |
| 1158 | if (!trigger) |
| 1159 | return -EINVAL; |
| 1160 | |
| 1161 | event = strsep(&trigger, ":"); |
| 1162 | |
| 1163 | ret = -EINVAL; |
| 1164 | event_enable_file = find_event_file(tr, system, event); |
| 1165 | if (!event_enable_file) |
| 1166 | goto out; |
| 1167 | |
| 1168 | enable = strcmp(cmd, ENABLE_EVENT_STR) == 0; |
| 1169 | |
| 1170 | trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger); |
| 1171 | |
| 1172 | ret = -ENOMEM; |
| 1173 | trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL); |
| 1174 | if (!trigger_data) |
| 1175 | goto out; |
| 1176 | |
| 1177 | enable_data = kzalloc(sizeof(*enable_data), GFP_KERNEL); |
| 1178 | if (!enable_data) { |
| 1179 | kfree(trigger_data); |
| 1180 | goto out; |
| 1181 | } |
| 1182 | |
| 1183 | trigger_data->count = -1; |
| 1184 | trigger_data->ops = trigger_ops; |
| 1185 | trigger_data->cmd_ops = cmd_ops; |
| 1186 | INIT_LIST_HEAD(&trigger_data->list); |
| 1187 | RCU_INIT_POINTER(trigger_data->filter, NULL); |
| 1188 | |
| 1189 | enable_data->enable = enable; |
| 1190 | enable_data->file = event_enable_file; |
| 1191 | trigger_data->private_data = enable_data; |
| 1192 | |
| 1193 | if (glob[0] == '!') { |
| 1194 | cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file); |
| 1195 | kfree(trigger_data); |
| 1196 | kfree(enable_data); |
| 1197 | ret = 0; |
| 1198 | goto out; |
| 1199 | } |
| 1200 | |
| 1201 | if (trigger) { |
| 1202 | number = strsep(&trigger, ":"); |
| 1203 | |
| 1204 | ret = -EINVAL; |
| 1205 | if (!strlen(number)) |
| 1206 | goto out_free; |
| 1207 | |
| 1208 | /* |
| 1209 | * We use the callback data field (which is a pointer) |
| 1210 | * as our counter. |
| 1211 | */ |
| 1212 | ret = kstrtoul(number, 0, &trigger_data->count); |
| 1213 | if (ret) |
| 1214 | goto out_free; |
| 1215 | } |
| 1216 | |
| 1217 | if (!param) /* if param is non-empty, it's supposed to be a filter */ |
| 1218 | goto out_reg; |
| 1219 | |
| 1220 | if (!cmd_ops->set_filter) |
| 1221 | goto out_reg; |
| 1222 | |
| 1223 | ret = cmd_ops->set_filter(param, trigger_data, file); |
| 1224 | if (ret < 0) |
| 1225 | goto out_free; |
| 1226 | |
| 1227 | out_reg: |
| 1228 | /* Don't let event modules unload while probe registered */ |
| 1229 | ret = try_module_get(event_enable_file->event_call->mod); |
| 1230 | if (!ret) { |
| 1231 | ret = -EBUSY; |
| 1232 | goto out_free; |
| 1233 | } |
| 1234 | |
| 1235 | ret = trace_event_enable_disable(event_enable_file, 1, 1); |
| 1236 | if (ret < 0) |
| 1237 | goto out_put; |
| 1238 | ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file); |
| 1239 | /* |
| 1240 | * The above returns on success the # of functions enabled, |
| 1241 | * but if it didn't find any functions it returns zero. |
| 1242 | * Consider no functions a failure too. |
| 1243 | */ |
| 1244 | if (!ret) { |
| 1245 | ret = -ENOENT; |
| 1246 | goto out_disable; |
| 1247 | } else if (ret < 0) |
| 1248 | goto out_disable; |
| 1249 | /* Just return zero, not the number of enabled functions */ |
| 1250 | ret = 0; |
| 1251 | out: |
| 1252 | return ret; |
| 1253 | |
| 1254 | out_disable: |
| 1255 | trace_event_enable_disable(event_enable_file, 0, 1); |
| 1256 | out_put: |
| 1257 | module_put(event_enable_file->event_call->mod); |
| 1258 | out_free: |
Tom Zanussi | bac5fb9 | 2013-10-24 08:59:29 -0500 | [diff] [blame] | 1259 | if (cmd_ops->set_filter) |
| 1260 | cmd_ops->set_filter(NULL, trigger_data, NULL); |
Tom Zanussi | 7862ad1 | 2013-10-24 08:59:28 -0500 | [diff] [blame] | 1261 | kfree(trigger_data); |
| 1262 | kfree(enable_data); |
| 1263 | goto out; |
| 1264 | } |
| 1265 | |
| 1266 | static int event_enable_register_trigger(char *glob, |
| 1267 | struct event_trigger_ops *ops, |
| 1268 | struct event_trigger_data *data, |
| 1269 | struct ftrace_event_file *file) |
| 1270 | { |
| 1271 | struct enable_trigger_data *enable_data = data->private_data; |
| 1272 | struct enable_trigger_data *test_enable_data; |
| 1273 | struct event_trigger_data *test; |
| 1274 | int ret = 0; |
| 1275 | |
| 1276 | list_for_each_entry_rcu(test, &file->triggers, list) { |
| 1277 | test_enable_data = test->private_data; |
| 1278 | if (test_enable_data && |
| 1279 | (test_enable_data->file == enable_data->file)) { |
| 1280 | ret = -EEXIST; |
| 1281 | goto out; |
| 1282 | } |
| 1283 | } |
| 1284 | |
| 1285 | if (data->ops->init) { |
| 1286 | ret = data->ops->init(data->ops, data); |
| 1287 | if (ret < 0) |
| 1288 | goto out; |
| 1289 | } |
| 1290 | |
| 1291 | list_add_rcu(&data->list, &file->triggers); |
| 1292 | ret++; |
| 1293 | |
| 1294 | if (trace_event_trigger_enable_disable(file, 1) < 0) { |
| 1295 | list_del_rcu(&data->list); |
| 1296 | ret--; |
| 1297 | } |
Tom Zanussi | bac5fb9 | 2013-10-24 08:59:29 -0500 | [diff] [blame] | 1298 | update_cond_flag(file); |
Tom Zanussi | 7862ad1 | 2013-10-24 08:59:28 -0500 | [diff] [blame] | 1299 | out: |
| 1300 | return ret; |
| 1301 | } |
| 1302 | |
| 1303 | static void event_enable_unregister_trigger(char *glob, |
| 1304 | struct event_trigger_ops *ops, |
| 1305 | struct event_trigger_data *test, |
| 1306 | struct ftrace_event_file *file) |
| 1307 | { |
| 1308 | struct enable_trigger_data *test_enable_data = test->private_data; |
| 1309 | struct enable_trigger_data *enable_data; |
| 1310 | struct event_trigger_data *data; |
| 1311 | bool unregistered = false; |
| 1312 | |
| 1313 | list_for_each_entry_rcu(data, &file->triggers, list) { |
| 1314 | enable_data = data->private_data; |
| 1315 | if (enable_data && |
| 1316 | (enable_data->file == test_enable_data->file)) { |
| 1317 | unregistered = true; |
| 1318 | list_del_rcu(&data->list); |
Tom Zanussi | bac5fb9 | 2013-10-24 08:59:29 -0500 | [diff] [blame] | 1319 | update_cond_flag(file); |
Tom Zanussi | 7862ad1 | 2013-10-24 08:59:28 -0500 | [diff] [blame] | 1320 | trace_event_trigger_enable_disable(file, 0); |
| 1321 | break; |
| 1322 | } |
| 1323 | } |
| 1324 | |
| 1325 | if (unregistered && data->ops->free) |
| 1326 | data->ops->free(data->ops, data); |
| 1327 | } |
| 1328 | |
| 1329 | static struct event_trigger_ops * |
| 1330 | event_enable_get_trigger_ops(char *cmd, char *param) |
| 1331 | { |
| 1332 | struct event_trigger_ops *ops; |
| 1333 | bool enable; |
| 1334 | |
| 1335 | enable = strcmp(cmd, ENABLE_EVENT_STR) == 0; |
| 1336 | |
| 1337 | if (enable) |
| 1338 | ops = param ? &event_enable_count_trigger_ops : |
| 1339 | &event_enable_trigger_ops; |
| 1340 | else |
| 1341 | ops = param ? &event_disable_count_trigger_ops : |
| 1342 | &event_disable_trigger_ops; |
| 1343 | |
| 1344 | return ops; |
| 1345 | } |
| 1346 | |
| 1347 | static struct event_command trigger_enable_cmd = { |
| 1348 | .name = ENABLE_EVENT_STR, |
| 1349 | .trigger_type = ETT_EVENT_ENABLE, |
| 1350 | .func = event_enable_trigger_func, |
| 1351 | .reg = event_enable_register_trigger, |
| 1352 | .unreg = event_enable_unregister_trigger, |
| 1353 | .get_trigger_ops = event_enable_get_trigger_ops, |
Tom Zanussi | bac5fb9 | 2013-10-24 08:59:29 -0500 | [diff] [blame] | 1354 | .set_filter = set_trigger_filter, |
Tom Zanussi | 7862ad1 | 2013-10-24 08:59:28 -0500 | [diff] [blame] | 1355 | }; |
| 1356 | |
| 1357 | static struct event_command trigger_disable_cmd = { |
| 1358 | .name = DISABLE_EVENT_STR, |
| 1359 | .trigger_type = ETT_EVENT_ENABLE, |
| 1360 | .func = event_enable_trigger_func, |
| 1361 | .reg = event_enable_register_trigger, |
| 1362 | .unreg = event_enable_unregister_trigger, |
| 1363 | .get_trigger_ops = event_enable_get_trigger_ops, |
Tom Zanussi | bac5fb9 | 2013-10-24 08:59:29 -0500 | [diff] [blame] | 1364 | .set_filter = set_trigger_filter, |
Tom Zanussi | 7862ad1 | 2013-10-24 08:59:28 -0500 | [diff] [blame] | 1365 | }; |
| 1366 | |
| 1367 | static __init void unregister_trigger_enable_disable_cmds(void) |
| 1368 | { |
| 1369 | unregister_event_command(&trigger_enable_cmd); |
| 1370 | unregister_event_command(&trigger_disable_cmd); |
| 1371 | } |
| 1372 | |
| 1373 | static __init int register_trigger_enable_disable_cmds(void) |
| 1374 | { |
| 1375 | int ret; |
| 1376 | |
| 1377 | ret = register_event_command(&trigger_enable_cmd); |
| 1378 | if (WARN_ON(ret < 0)) |
| 1379 | return ret; |
| 1380 | ret = register_event_command(&trigger_disable_cmd); |
| 1381 | if (WARN_ON(ret < 0)) |
| 1382 | unregister_trigger_enable_disable_cmds(); |
| 1383 | |
| 1384 | return ret; |
| 1385 | } |
| 1386 | |
Tom Zanussi | 2a2df32 | 2013-10-24 08:59:25 -0500 | [diff] [blame] | 1387 | static __init int register_trigger_traceon_traceoff_cmds(void) |
| 1388 | { |
| 1389 | int ret; |
| 1390 | |
| 1391 | ret = register_event_command(&trigger_traceon_cmd); |
| 1392 | if (WARN_ON(ret < 0)) |
| 1393 | return ret; |
| 1394 | ret = register_event_command(&trigger_traceoff_cmd); |
| 1395 | if (WARN_ON(ret < 0)) |
| 1396 | unregister_trigger_traceon_traceoff_cmds(); |
| 1397 | |
| 1398 | return ret; |
| 1399 | } |
| 1400 | |
Tom Zanussi | 85f2b08 | 2013-10-24 08:59:24 -0500 | [diff] [blame] | 1401 | __init int register_trigger_cmds(void) |
| 1402 | { |
Tom Zanussi | 2a2df32 | 2013-10-24 08:59:25 -0500 | [diff] [blame] | 1403 | register_trigger_traceon_traceoff_cmds(); |
Tom Zanussi | 93e31ff | 2013-10-24 08:59:26 -0500 | [diff] [blame] | 1404 | register_trigger_snapshot_cmd(); |
Tom Zanussi | f21ecbb | 2013-10-24 08:59:27 -0500 | [diff] [blame] | 1405 | register_trigger_stacktrace_cmd(); |
Tom Zanussi | 7862ad1 | 2013-10-24 08:59:28 -0500 | [diff] [blame] | 1406 | register_trigger_enable_disable_cmds(); |
Tom Zanussi | 2a2df32 | 2013-10-24 08:59:25 -0500 | [diff] [blame] | 1407 | |
Tom Zanussi | 85f2b08 | 2013-10-24 08:59:24 -0500 | [diff] [blame] | 1408 | return 0; |
| 1409 | } |