| 1 | /* |
| 2 | * ltt/ltt-tracer.c |
| 3 | * |
| 4 | * (C) Copyright 2005-2008 - |
| 5 | * Mathieu Desnoyers (mathieu.desnoyers@polymtl.ca) |
| 6 | * |
| 7 | * Tracing management internal kernel API. Trace buffer allocation/free, tracing |
| 8 | * start/stop. |
| 9 | * |
| 10 | * Author: |
| 11 | * Mathieu Desnoyers (mathieu.desnoyers@polymtl.ca) |
| 12 | * |
| 13 | * Inspired from LTT : |
| 14 | * Karim Yaghmour (karim@opersys.com) |
| 15 | * Tom Zanussi (zanussi@us.ibm.com) |
| 16 | * Bob Wisniewski (bob@watson.ibm.com) |
| 17 | * And from K42 : |
| 18 | * Bob Wisniewski (bob@watson.ibm.com) |
| 19 | * |
| 20 | * Changelog: |
| 21 | * 22/09/06, Move to the marker/probes mechanism. |
| 22 | * 19/10/05, Complete lockless mechanism. |
| 23 | * 27/05/05, Modular redesign and rewrite. |
| 24 | */ |
| 25 | |
| 26 | //ust// #include <linux/time.h> |
| 27 | //ust// #include <linux/ltt-tracer.h> |
| 28 | //ust// #include <linux/module.h> |
| 29 | //ust// #include <linux/string.h> |
| 30 | //ust// #include <linux/slab.h> |
| 31 | //ust// #include <linux/init.h> |
| 32 | //ust// #include <linux/rcupdate.h> |
| 33 | //ust// #include <linux/sched.h> |
| 34 | //ust// #include <linux/bitops.h> |
| 35 | //ust// #include <linux/fs.h> |
| 36 | //ust// #include <linux/cpu.h> |
| 37 | //ust// #include <linux/kref.h> |
| 38 | //ust// #include <linux/delay.h> |
| 39 | //ust// #include <linux/vmalloc.h> |
| 40 | //ust// #include <asm/atomic.h> |
| 41 | #include "kernelcompat.h" |
| 42 | #include "tracercore.h" |
| 43 | #include "tracer.h" |
| 44 | #include "usterr.h" |
| 45 | |
| 46 | //ust// static void async_wakeup(unsigned long data); |
| 47 | //ust// |
| 48 | //ust// static DEFINE_TIMER(ltt_async_wakeup_timer, async_wakeup, 0, 0); |
| 49 | |
| 50 | /* Default callbacks for modules */ |
| 51 | notrace int ltt_filter_control_default(enum ltt_filter_control_msg msg, |
| 52 | struct ltt_trace_struct *trace) |
| 53 | { |
| 54 | return 0; |
| 55 | } |
| 56 | |
| 57 | int ltt_statedump_default(struct ltt_trace_struct *trace) |
| 58 | { |
| 59 | return 0; |
| 60 | } |
| 61 | |
| 62 | /* Callbacks for registered modules */ |
| 63 | |
| 64 | int (*ltt_filter_control_functor) |
| 65 | (enum ltt_filter_control_msg msg, struct ltt_trace_struct *trace) = |
| 66 | ltt_filter_control_default; |
| 67 | struct module *ltt_filter_control_owner; |
| 68 | |
| 69 | /* These function pointers are protected by a trace activation check */ |
| 70 | struct module *ltt_run_filter_owner; |
| 71 | int (*ltt_statedump_functor)(struct ltt_trace_struct *trace) = |
| 72 | ltt_statedump_default; |
| 73 | struct module *ltt_statedump_owner; |
| 74 | |
| 75 | struct chan_info_struct { |
| 76 | const char *name; |
| 77 | unsigned int def_subbufsize; |
| 78 | unsigned int def_subbufcount; |
| 79 | } chan_infos[] = { |
| 80 | [LTT_CHANNEL_METADATA] = { |
| 81 | LTT_METADATA_CHANNEL, |
| 82 | LTT_DEFAULT_SUBBUF_SIZE_LOW, |
| 83 | LTT_DEFAULT_N_SUBBUFS_LOW, |
| 84 | }, |
| 85 | [LTT_CHANNEL_UST] = { |
| 86 | LTT_UST_CHANNEL, |
| 87 | LTT_DEFAULT_SUBBUF_SIZE_HIGH, |
| 88 | LTT_DEFAULT_N_SUBBUFS_HIGH, |
| 89 | }, |
| 90 | }; |
| 91 | |
| 92 | static enum ltt_channels get_channel_type_from_name(const char *name) |
| 93 | { |
| 94 | int i; |
| 95 | |
| 96 | if (!name) |
| 97 | return LTT_CHANNEL_UST; |
| 98 | |
| 99 | for (i = 0; i < ARRAY_SIZE(chan_infos); i++) |
| 100 | if (chan_infos[i].name && !strcmp(name, chan_infos[i].name)) |
| 101 | return (enum ltt_channels)i; |
| 102 | |
| 103 | return LTT_CHANNEL_UST; |
| 104 | } |
| 105 | |
| 106 | /** |
| 107 | * ltt_module_register - LTT module registration |
| 108 | * @name: module type |
| 109 | * @function: callback to register |
| 110 | * @owner: module which owns the callback |
| 111 | * |
| 112 | * The module calling this registration function must ensure that no |
| 113 | * trap-inducing code will be executed by "function". E.g. vmalloc_sync_all() |
| 114 | * must be called between a vmalloc and the moment the memory is made visible to |
| 115 | * "function". This registration acts as a vmalloc_sync_all. Therefore, only if |
| 116 | * the module allocates virtual memory after its registration must it |
| 117 | * synchronize the TLBs. |
| 118 | */ |
| 119 | //ust// int ltt_module_register(enum ltt_module_function name, void *function, |
| 120 | //ust// struct module *owner) |
| 121 | //ust// { |
| 122 | //ust// int ret = 0; |
| 123 | //ust// |
| 124 | //ust// /* |
| 125 | //ust// * Make sure no page fault can be triggered by the module about to be |
| 126 | //ust// * registered. We deal with this here so we don't have to call |
| 127 | //ust// * vmalloc_sync_all() in each module's init. |
| 128 | //ust// */ |
| 129 | //ust// vmalloc_sync_all(); |
| 130 | //ust// |
| 131 | //ust// switch (name) { |
| 132 | //ust// case LTT_FUNCTION_RUN_FILTER: |
| 133 | //ust// if (ltt_run_filter_owner != NULL) { |
| 134 | //ust// ret = -EEXIST; |
| 135 | //ust// goto end; |
| 136 | //ust// } |
| 137 | //ust// ltt_filter_register((ltt_run_filter_functor)function); |
| 138 | //ust// ltt_run_filter_owner = owner; |
| 139 | //ust// break; |
| 140 | //ust// case LTT_FUNCTION_FILTER_CONTROL: |
| 141 | //ust// if (ltt_filter_control_owner != NULL) { |
| 142 | //ust// ret = -EEXIST; |
| 143 | //ust// goto end; |
| 144 | //ust// } |
| 145 | //ust// ltt_filter_control_functor = |
| 146 | //ust// (int (*)(enum ltt_filter_control_msg, |
| 147 | //ust// struct ltt_trace_struct *))function; |
| 148 | //ust// ltt_filter_control_owner = owner; |
| 149 | //ust// break; |
| 150 | //ust// case LTT_FUNCTION_STATEDUMP: |
| 151 | //ust// if (ltt_statedump_owner != NULL) { |
| 152 | //ust// ret = -EEXIST; |
| 153 | //ust// goto end; |
| 154 | //ust// } |
| 155 | //ust// ltt_statedump_functor = |
| 156 | //ust// (int (*)(struct ltt_trace_struct *))function; |
| 157 | //ust// ltt_statedump_owner = owner; |
| 158 | //ust// break; |
| 159 | //ust// } |
| 160 | //ust// |
| 161 | //ust// end: |
| 162 | //ust// |
| 163 | //ust// return ret; |
| 164 | //ust// } |
| 165 | //ust// EXPORT_SYMBOL_GPL(ltt_module_register); |
| 166 | |
| 167 | /** |
| 168 | * ltt_module_unregister - LTT module unregistration |
| 169 | * @name: module type |
| 170 | */ |
| 171 | //ust// void ltt_module_unregister(enum ltt_module_function name) |
| 172 | //ust// { |
| 173 | //ust// switch (name) { |
| 174 | //ust// case LTT_FUNCTION_RUN_FILTER: |
| 175 | //ust// ltt_filter_unregister(); |
| 176 | //ust// ltt_run_filter_owner = NULL; |
| 177 | //ust// /* Wait for preempt sections to finish */ |
| 178 | //ust// synchronize_sched(); |
| 179 | //ust// break; |
| 180 | //ust// case LTT_FUNCTION_FILTER_CONTROL: |
| 181 | //ust// ltt_filter_control_functor = ltt_filter_control_default; |
| 182 | //ust// ltt_filter_control_owner = NULL; |
| 183 | //ust// break; |
| 184 | //ust// case LTT_FUNCTION_STATEDUMP: |
| 185 | //ust// ltt_statedump_functor = ltt_statedump_default; |
| 186 | //ust// ltt_statedump_owner = NULL; |
| 187 | //ust// break; |
| 188 | //ust// } |
| 189 | //ust// |
| 190 | //ust// } |
| 191 | //ust// EXPORT_SYMBOL_GPL(ltt_module_unregister); |
| 192 | |
| 193 | static LIST_HEAD(ltt_transport_list); |
| 194 | |
| 195 | /** |
| 196 | * ltt_transport_register - LTT transport registration |
| 197 | * @transport: transport structure |
| 198 | * |
| 199 | * Registers a transport which can be used as output to extract the data out of |
| 200 | * LTTng. The module calling this registration function must ensure that no |
| 201 | * trap-inducing code will be executed by the transport functions. E.g. |
| 202 | * vmalloc_sync_all() must be called between a vmalloc and the moment the memory |
| 203 | * is made visible to the transport function. This registration acts as a |
| 204 | * vmalloc_sync_all. Therefore, only if the module allocates virtual memory |
| 205 | * after its registration must it synchronize the TLBs. |
| 206 | */ |
| 207 | void ltt_transport_register(struct ltt_transport *transport) |
| 208 | { |
| 209 | /* |
| 210 | * Make sure no page fault can be triggered by the module about to be |
| 211 | * registered. We deal with this here so we don't have to call |
| 212 | * vmalloc_sync_all() in each module's init. |
| 213 | */ |
| 214 | //ust// vmalloc_sync_all(); |
| 215 | |
| 216 | ltt_lock_traces(); |
| 217 | list_add_tail(&transport->node, <t_transport_list); |
| 218 | ltt_unlock_traces(); |
| 219 | } |
| 220 | //ust// EXPORT_SYMBOL_GPL(ltt_transport_register); |
| 221 | |
| 222 | /** |
| 223 | * ltt_transport_unregister - LTT transport unregistration |
| 224 | * @transport: transport structure |
| 225 | */ |
| 226 | void ltt_transport_unregister(struct ltt_transport *transport) |
| 227 | { |
| 228 | ltt_lock_traces(); |
| 229 | list_del(&transport->node); |
| 230 | ltt_unlock_traces(); |
| 231 | } |
| 232 | //ust// EXPORT_SYMBOL_GPL(ltt_transport_unregister); |
| 233 | |
| 234 | static inline int is_channel_overwrite(enum ltt_channels chan, |
| 235 | enum trace_mode mode) |
| 236 | { |
| 237 | switch (mode) { |
| 238 | case LTT_TRACE_NORMAL: |
| 239 | return 0; |
| 240 | case LTT_TRACE_FLIGHT: |
| 241 | switch (chan) { |
| 242 | case LTT_CHANNEL_METADATA: |
| 243 | return 0; |
| 244 | default: |
| 245 | return 1; |
| 246 | } |
| 247 | case LTT_TRACE_HYBRID: |
| 248 | switch (chan) { |
| 249 | case LTT_CHANNEL_METADATA: |
| 250 | return 0; |
| 251 | default: |
| 252 | return 1; |
| 253 | } |
| 254 | default: |
| 255 | return 0; |
| 256 | } |
| 257 | } |
| 258 | |
| 259 | /** |
| 260 | * ltt_write_trace_header - Write trace header |
| 261 | * @trace: Trace information |
| 262 | * @header: Memory address where the information must be written to |
| 263 | */ |
| 264 | void notrace ltt_write_trace_header(struct ltt_trace_struct *trace, |
| 265 | struct ltt_subbuffer_header *header) |
| 266 | { |
| 267 | header->magic_number = LTT_TRACER_MAGIC_NUMBER; |
| 268 | header->major_version = LTT_TRACER_VERSION_MAJOR; |
| 269 | header->minor_version = LTT_TRACER_VERSION_MINOR; |
| 270 | header->arch_size = sizeof(void *); |
| 271 | header->alignment = ltt_get_alignment(); |
| 272 | header->start_time_sec = trace->start_time.tv_sec; |
| 273 | header->start_time_usec = trace->start_time.tv_usec; |
| 274 | header->start_freq = trace->start_freq; |
| 275 | header->freq_scale = trace->freq_scale; |
| 276 | } |
| 277 | //ust// EXPORT_SYMBOL_GPL(ltt_write_trace_header); |
| 278 | |
| 279 | static void trace_async_wakeup(struct ltt_trace_struct *trace) |
| 280 | { |
| 281 | int i; |
| 282 | struct ltt_channel_struct *chan; |
| 283 | |
| 284 | /* Must check each channel for pending read wakeup */ |
| 285 | for (i = 0; i < trace->nr_channels; i++) { |
| 286 | chan = &trace->channels[i]; |
| 287 | if (chan->active) |
| 288 | trace->ops->wakeup_channel(chan); |
| 289 | } |
| 290 | } |
| 291 | |
| 292 | //ust// /* Timer to send async wakeups to the readers */ |
| 293 | //ust// static void async_wakeup(unsigned long data) |
| 294 | //ust// { |
| 295 | //ust// struct ltt_trace_struct *trace; |
| 296 | //ust// |
| 297 | //ust// /* |
| 298 | //ust// * PREEMPT_RT does not allow spinlocks to be taken within preempt |
| 299 | //ust// * disable sections (spinlock taken in wake_up). However, mainline won't |
| 300 | //ust// * allow mutex to be taken in interrupt context. Ugly. |
| 301 | //ust// * A proper way to do this would be to turn the timer into a |
| 302 | //ust// * periodically woken up thread, but it adds to the footprint. |
| 303 | //ust// */ |
| 304 | //ust// #ifndef CONFIG_PREEMPT_RT |
| 305 | //ust// rcu_read_lock_sched(); |
| 306 | //ust// #else |
| 307 | //ust// ltt_lock_traces(); |
| 308 | //ust// #endif |
| 309 | //ust// list_for_each_entry_rcu(trace, <t_traces.head, list) { |
| 310 | //ust// trace_async_wakeup(trace); |
| 311 | //ust// } |
| 312 | //ust// #ifndef CONFIG_PREEMPT_RT |
| 313 | //ust// rcu_read_unlock_sched(); |
| 314 | //ust// #else |
| 315 | //ust// ltt_unlock_traces(); |
| 316 | //ust// #endif |
| 317 | //ust// |
| 318 | //ust// mod_timer(<t_async_wakeup_timer, jiffies + LTT_PERCPU_TIMER_INTERVAL); |
| 319 | //ust// } |
| 320 | |
| 321 | /** |
| 322 | * _ltt_trace_find - find a trace by given name. |
| 323 | * trace_name: trace name |
| 324 | * |
| 325 | * Returns a pointer to the trace structure, NULL if not found. |
| 326 | */ |
| 327 | struct ltt_trace_struct *_ltt_trace_find(const char *trace_name) |
| 328 | { |
| 329 | struct ltt_trace_struct *trace; |
| 330 | |
| 331 | list_for_each_entry(trace, <t_traces.head, list) |
| 332 | if (!strncmp(trace->trace_name, trace_name, NAME_MAX)) |
| 333 | return trace; |
| 334 | |
| 335 | return NULL; |
| 336 | } |
| 337 | |
| 338 | /* _ltt_trace_find_setup : |
| 339 | * find a trace in setup list by given name. |
| 340 | * |
| 341 | * Returns a pointer to the trace structure, NULL if not found. |
| 342 | */ |
| 343 | struct ltt_trace_struct *_ltt_trace_find_setup(const char *trace_name) |
| 344 | { |
| 345 | struct ltt_trace_struct *trace; |
| 346 | |
| 347 | list_for_each_entry(trace, <t_traces.setup_head, list) |
| 348 | if (!strncmp(trace->trace_name, trace_name, NAME_MAX)) |
| 349 | return trace; |
| 350 | |
| 351 | return NULL; |
| 352 | } |
| 353 | //ust// EXPORT_SYMBOL_GPL(_ltt_trace_find_setup); |
| 354 | |
| 355 | /** |
| 356 | * ltt_release_transport - Release an LTT transport |
| 357 | * @kref : reference count on the transport |
| 358 | */ |
| 359 | void ltt_release_transport(struct kref *kref) |
| 360 | { |
| 361 | struct ltt_trace_struct *trace = container_of(kref, |
| 362 | struct ltt_trace_struct, ltt_transport_kref); |
| 363 | //ust// trace->ops->remove_dirs(trace); |
| 364 | } |
| 365 | //ust// EXPORT_SYMBOL_GPL(ltt_release_transport); |
| 366 | |
| 367 | /** |
| 368 | * ltt_release_trace - Release a LTT trace |
| 369 | * @kref : reference count on the trace |
| 370 | */ |
| 371 | void ltt_release_trace(struct kref *kref) |
| 372 | { |
| 373 | struct ltt_trace_struct *trace = container_of(kref, |
| 374 | struct ltt_trace_struct, kref); |
| 375 | ltt_channels_trace_free(trace->channels); |
| 376 | kfree(trace); |
| 377 | } |
| 378 | //ust// EXPORT_SYMBOL_GPL(ltt_release_trace); |
| 379 | |
| 380 | static inline void prepare_chan_size_num(unsigned int *subbuf_size, |
| 381 | unsigned int *n_subbufs) |
| 382 | { |
| 383 | *subbuf_size = 1 << get_count_order(*subbuf_size); |
| 384 | *n_subbufs = 1 << get_count_order(*n_subbufs); |
| 385 | |
| 386 | /* Subbuf size and number must both be power of two */ |
| 387 | WARN_ON(hweight32(*subbuf_size) != 1); |
| 388 | WARN_ON(hweight32(*n_subbufs) != 1); |
| 389 | } |
| 390 | |
| 391 | int _ltt_trace_setup(const char *trace_name) |
| 392 | { |
| 393 | int err = 0; |
| 394 | struct ltt_trace_struct *new_trace = NULL; |
| 395 | int metadata_index; |
| 396 | unsigned int chan; |
| 397 | enum ltt_channels chantype; |
| 398 | |
| 399 | if (_ltt_trace_find_setup(trace_name)) { |
| 400 | printk(KERN_ERR "LTT : Trace name %s already used.\n", |
| 401 | trace_name); |
| 402 | err = -EEXIST; |
| 403 | goto traces_error; |
| 404 | } |
| 405 | |
| 406 | if (_ltt_trace_find(trace_name)) { |
| 407 | printk(KERN_ERR "LTT : Trace name %s already used.\n", |
| 408 | trace_name); |
| 409 | err = -EEXIST; |
| 410 | goto traces_error; |
| 411 | } |
| 412 | |
| 413 | new_trace = kzalloc(sizeof(struct ltt_trace_struct), GFP_KERNEL); |
| 414 | if (!new_trace) { |
| 415 | printk(KERN_ERR |
| 416 | "LTT : Unable to allocate memory for trace %s\n", |
| 417 | trace_name); |
| 418 | err = -ENOMEM; |
| 419 | goto traces_error; |
| 420 | } |
| 421 | strncpy(new_trace->trace_name, trace_name, NAME_MAX); |
| 422 | new_trace->channels = ltt_channels_trace_alloc(&new_trace->nr_channels, |
| 423 | 0, 1); |
| 424 | if (!new_trace->channels) { |
| 425 | printk(KERN_ERR |
| 426 | "LTT : Unable to allocate memory for chaninfo %s\n", |
| 427 | trace_name); |
| 428 | err = -ENOMEM; |
| 429 | goto trace_free; |
| 430 | } |
| 431 | |
| 432 | /* |
| 433 | * Force metadata channel to active, no overwrite. |
| 434 | */ |
| 435 | metadata_index = ltt_channels_get_index_from_name("metadata"); |
| 436 | WARN_ON(metadata_index < 0); |
| 437 | new_trace->channels[metadata_index].overwrite = 0; |
| 438 | new_trace->channels[metadata_index].active = 1; |
| 439 | |
| 440 | /* |
| 441 | * Set hardcoded tracer defaults for some channels |
| 442 | */ |
| 443 | for (chan = 0; chan < new_trace->nr_channels; chan++) { |
| 444 | if (!(new_trace->channels[chan].active)) |
| 445 | continue; |
| 446 | |
| 447 | chantype = get_channel_type_from_name( |
| 448 | ltt_channels_get_name_from_index(chan)); |
| 449 | new_trace->channels[chan].subbuf_size = |
| 450 | chan_infos[chantype].def_subbufsize; |
| 451 | new_trace->channels[chan].subbuf_cnt = |
| 452 | chan_infos[chantype].def_subbufcount; |
| 453 | } |
| 454 | |
| 455 | list_add(&new_trace->list, <t_traces.setup_head); |
| 456 | return 0; |
| 457 | |
| 458 | trace_free: |
| 459 | kfree(new_trace); |
| 460 | traces_error: |
| 461 | return err; |
| 462 | } |
| 463 | //ust// EXPORT_SYMBOL_GPL(_ltt_trace_setup); |
| 464 | |
| 465 | |
| 466 | int ltt_trace_setup(const char *trace_name) |
| 467 | { |
| 468 | int ret; |
| 469 | ltt_lock_traces(); |
| 470 | ret = _ltt_trace_setup(trace_name); |
| 471 | ltt_unlock_traces(); |
| 472 | return ret; |
| 473 | } |
| 474 | //ust// EXPORT_SYMBOL_GPL(ltt_trace_setup); |
| 475 | |
| 476 | /* must be called from within a traces lock. */ |
| 477 | static void _ltt_trace_free(struct ltt_trace_struct *trace) |
| 478 | { |
| 479 | list_del(&trace->list); |
| 480 | kfree(trace); |
| 481 | } |
| 482 | |
| 483 | int ltt_trace_set_type(const char *trace_name, const char *trace_type) |
| 484 | { |
| 485 | int err = 0; |
| 486 | struct ltt_trace_struct *trace; |
| 487 | struct ltt_transport *tran_iter, *transport = NULL; |
| 488 | |
| 489 | ltt_lock_traces(); |
| 490 | |
| 491 | trace = _ltt_trace_find_setup(trace_name); |
| 492 | if (!trace) { |
| 493 | printk(KERN_ERR "LTT : Trace not found %s\n", trace_name); |
| 494 | err = -ENOENT; |
| 495 | goto traces_error; |
| 496 | } |
| 497 | |
| 498 | list_for_each_entry(tran_iter, <t_transport_list, node) { |
| 499 | if (!strcmp(tran_iter->name, trace_type)) { |
| 500 | transport = tran_iter; |
| 501 | break; |
| 502 | } |
| 503 | } |
| 504 | if (!transport) { |
| 505 | printk(KERN_ERR "LTT : Transport %s is not present.\n", |
| 506 | trace_type); |
| 507 | err = -EINVAL; |
| 508 | goto traces_error; |
| 509 | } |
| 510 | |
| 511 | trace->transport = transport; |
| 512 | |
| 513 | traces_error: |
| 514 | ltt_unlock_traces(); |
| 515 | return err; |
| 516 | } |
| 517 | //ust// EXPORT_SYMBOL_GPL(ltt_trace_set_type); |
| 518 | |
| 519 | int ltt_trace_set_channel_subbufsize(const char *trace_name, |
| 520 | const char *channel_name, unsigned int size) |
| 521 | { |
| 522 | int err = 0; |
| 523 | struct ltt_trace_struct *trace; |
| 524 | int index; |
| 525 | |
| 526 | ltt_lock_traces(); |
| 527 | |
| 528 | trace = _ltt_trace_find_setup(trace_name); |
| 529 | if (!trace) { |
| 530 | printk(KERN_ERR "LTT : Trace not found %s\n", trace_name); |
| 531 | err = -ENOENT; |
| 532 | goto traces_error; |
| 533 | } |
| 534 | |
| 535 | index = ltt_channels_get_index_from_name(channel_name); |
| 536 | if (index < 0) { |
| 537 | printk(KERN_ERR "LTT : Channel %s not found\n", channel_name); |
| 538 | err = -ENOENT; |
| 539 | goto traces_error; |
| 540 | } |
| 541 | trace->channels[index].subbuf_size = size; |
| 542 | |
| 543 | traces_error: |
| 544 | ltt_unlock_traces(); |
| 545 | return err; |
| 546 | } |
| 547 | //ust// EXPORT_SYMBOL_GPL(ltt_trace_set_channel_subbufsize); |
| 548 | |
| 549 | int ltt_trace_set_channel_subbufcount(const char *trace_name, |
| 550 | const char *channel_name, unsigned int cnt) |
| 551 | { |
| 552 | int err = 0; |
| 553 | struct ltt_trace_struct *trace; |
| 554 | int index; |
| 555 | |
| 556 | ltt_lock_traces(); |
| 557 | |
| 558 | trace = _ltt_trace_find_setup(trace_name); |
| 559 | if (!trace) { |
| 560 | printk(KERN_ERR "LTT : Trace not found %s\n", trace_name); |
| 561 | err = -ENOENT; |
| 562 | goto traces_error; |
| 563 | } |
| 564 | |
| 565 | index = ltt_channels_get_index_from_name(channel_name); |
| 566 | if (index < 0) { |
| 567 | printk(KERN_ERR "LTT : Channel %s not found\n", channel_name); |
| 568 | err = -ENOENT; |
| 569 | goto traces_error; |
| 570 | } |
| 571 | trace->channels[index].subbuf_cnt = cnt; |
| 572 | |
| 573 | traces_error: |
| 574 | ltt_unlock_traces(); |
| 575 | return err; |
| 576 | } |
| 577 | //ust// EXPORT_SYMBOL_GPL(ltt_trace_set_channel_subbufcount); |
| 578 | |
| 579 | int ltt_trace_set_channel_enable(const char *trace_name, |
| 580 | const char *channel_name, unsigned int enable) |
| 581 | { |
| 582 | int err = 0; |
| 583 | struct ltt_trace_struct *trace; |
| 584 | int index; |
| 585 | |
| 586 | ltt_lock_traces(); |
| 587 | |
| 588 | trace = _ltt_trace_find_setup(trace_name); |
| 589 | if (!trace) { |
| 590 | printk(KERN_ERR "LTT : Trace not found %s\n", trace_name); |
| 591 | err = -ENOENT; |
| 592 | goto traces_error; |
| 593 | } |
| 594 | |
| 595 | /* |
| 596 | * Datas in metadata channel(marker info) is necessary to be able to |
| 597 | * read the trace, we always enable this channel. |
| 598 | */ |
| 599 | if (!enable && !strcmp(channel_name, "metadata")) { |
| 600 | printk(KERN_ERR "LTT : Trying to disable metadata channel\n"); |
| 601 | err = -EINVAL; |
| 602 | goto traces_error; |
| 603 | } |
| 604 | |
| 605 | index = ltt_channels_get_index_from_name(channel_name); |
| 606 | if (index < 0) { |
| 607 | printk(KERN_ERR "LTT : Channel %s not found\n", channel_name); |
| 608 | err = -ENOENT; |
| 609 | goto traces_error; |
| 610 | } |
| 611 | |
| 612 | trace->channels[index].active = enable; |
| 613 | |
| 614 | traces_error: |
| 615 | ltt_unlock_traces(); |
| 616 | return err; |
| 617 | } |
| 618 | //ust// EXPORT_SYMBOL_GPL(ltt_trace_set_channel_enable); |
| 619 | |
| 620 | int ltt_trace_set_channel_overwrite(const char *trace_name, |
| 621 | const char *channel_name, unsigned int overwrite) |
| 622 | { |
| 623 | int err = 0; |
| 624 | struct ltt_trace_struct *trace; |
| 625 | int index; |
| 626 | |
| 627 | ltt_lock_traces(); |
| 628 | |
| 629 | trace = _ltt_trace_find_setup(trace_name); |
| 630 | if (!trace) { |
| 631 | printk(KERN_ERR "LTT : Trace not found %s\n", trace_name); |
| 632 | err = -ENOENT; |
| 633 | goto traces_error; |
| 634 | } |
| 635 | |
| 636 | /* |
| 637 | * Always put the metadata channel in non-overwrite mode : |
| 638 | * This is a very low traffic channel and it can't afford to have its |
| 639 | * data overwritten : this data (marker info) is necessary to be |
| 640 | * able to read the trace. |
| 641 | */ |
| 642 | if (overwrite && !strcmp(channel_name, "metadata")) { |
| 643 | printk(KERN_ERR "LTT : Trying to set metadata channel to " |
| 644 | "overwrite mode\n"); |
| 645 | err = -EINVAL; |
| 646 | goto traces_error; |
| 647 | } |
| 648 | |
| 649 | index = ltt_channels_get_index_from_name(channel_name); |
| 650 | if (index < 0) { |
| 651 | printk(KERN_ERR "LTT : Channel %s not found\n", channel_name); |
| 652 | err = -ENOENT; |
| 653 | goto traces_error; |
| 654 | } |
| 655 | |
| 656 | trace->channels[index].overwrite = overwrite; |
| 657 | |
| 658 | traces_error: |
| 659 | ltt_unlock_traces(); |
| 660 | return err; |
| 661 | } |
| 662 | //ust// EXPORT_SYMBOL_GPL(ltt_trace_set_channel_overwrite); |
| 663 | |
| 664 | int ltt_trace_alloc(const char *trace_name) |
| 665 | { |
| 666 | int err = 0; |
| 667 | struct ltt_trace_struct *trace; |
| 668 | int subbuf_size, subbuf_cnt; |
| 669 | unsigned long flags; |
| 670 | int chan; |
| 671 | const char *channel_name; |
| 672 | |
| 673 | ltt_lock_traces(); |
| 674 | |
| 675 | trace = _ltt_trace_find_setup(trace_name); |
| 676 | if (!trace) { |
| 677 | printk(KERN_ERR "LTT : Trace not found %s\n", trace_name); |
| 678 | err = -ENOENT; |
| 679 | goto traces_error; |
| 680 | } |
| 681 | |
| 682 | kref_init(&trace->kref); |
| 683 | kref_init(&trace->ltt_transport_kref); |
| 684 | //ust// init_waitqueue_head(&trace->kref_wq); |
| 685 | trace->active = 0; |
| 686 | //ust// get_trace_clock(); |
| 687 | trace->freq_scale = trace_clock_freq_scale(); |
| 688 | |
| 689 | if (!trace->transport) { |
| 690 | printk(KERN_ERR "LTT : Transport is not set.\n"); |
| 691 | err = -EINVAL; |
| 692 | goto transport_error; |
| 693 | } |
| 694 | //ust// if (!try_module_get(trace->transport->owner)) { |
| 695 | //ust// printk(KERN_ERR "LTT : Can't lock transport module.\n"); |
| 696 | //ust// err = -ENODEV; |
| 697 | //ust// goto transport_error; |
| 698 | //ust// } |
| 699 | trace->ops = &trace->transport->ops; |
| 700 | |
| 701 | //ust// err = trace->ops->create_dirs(trace); |
| 702 | //ust// if (err) { |
| 703 | //ust// printk(KERN_ERR "LTT : Can't create dir for trace %s.\n", |
| 704 | //ust// trace_name); |
| 705 | //ust// goto dirs_error; |
| 706 | //ust// } |
| 707 | |
| 708 | //ust// local_irq_save(flags); |
| 709 | trace->start_freq = trace_clock_frequency(); |
| 710 | trace->start_tsc = trace_clock_read64(); |
| 711 | gettimeofday(&trace->start_time, NULL); //ust// changed |
| 712 | //ust// local_irq_restore(flags); |
| 713 | |
| 714 | for (chan = 0; chan < trace->nr_channels; chan++) { |
| 715 | if (!(trace->channels[chan].active)) |
| 716 | continue; |
| 717 | |
| 718 | channel_name = ltt_channels_get_name_from_index(chan); |
| 719 | WARN_ON(!channel_name); |
| 720 | subbuf_size = trace->channels[chan].subbuf_size; |
| 721 | subbuf_cnt = trace->channels[chan].subbuf_cnt; |
| 722 | prepare_chan_size_num(&subbuf_size, &subbuf_cnt); |
| 723 | err = trace->ops->create_channel(trace_name, trace, |
| 724 | trace->dentry.trace_root, |
| 725 | channel_name, |
| 726 | &trace->channels[chan], |
| 727 | subbuf_size, |
| 728 | subbuf_cnt, |
| 729 | trace->channels[chan].overwrite); |
| 730 | if (err != 0) { |
| 731 | printk(KERN_ERR "LTT : Can't create channel %s.\n", |
| 732 | channel_name); |
| 733 | goto create_channel_error; |
| 734 | } |
| 735 | } |
| 736 | |
| 737 | list_del(&trace->list); |
| 738 | //ust// if (list_empty(<t_traces.head)) { |
| 739 | //ust// mod_timer(<t_async_wakeup_timer, |
| 740 | //ust// jiffies + LTT_PERCPU_TIMER_INTERVAL); |
| 741 | //ust// set_kernel_trace_flag_all_tasks(); |
| 742 | //ust// } |
| 743 | list_add_rcu(&trace->list, <t_traces.head); |
| 744 | //ust// synchronize_sched(); |
| 745 | |
| 746 | ltt_unlock_traces(); |
| 747 | |
| 748 | return 0; |
| 749 | |
| 750 | create_channel_error: |
| 751 | for (chan--; chan >= 0; chan--) |
| 752 | if (trace->channels[chan].active) |
| 753 | trace->ops->remove_channel(&trace->channels[chan]); |
| 754 | |
| 755 | dirs_error: |
| 756 | //ust// module_put(trace->transport->owner); |
| 757 | transport_error: |
| 758 | //ust// put_trace_clock(); |
| 759 | traces_error: |
| 760 | ltt_unlock_traces(); |
| 761 | return err; |
| 762 | } |
| 763 | //ust// EXPORT_SYMBOL_GPL(ltt_trace_alloc); |
| 764 | |
| 765 | /* |
| 766 | * It is worked as a wrapper for current version of ltt_control.ko. |
| 767 | * We will make a new ltt_control based on debugfs, and control each channel's |
| 768 | * buffer. |
| 769 | */ |
| 770 | static int ltt_trace_create(const char *trace_name, const char *trace_type, |
| 771 | enum trace_mode mode, |
| 772 | unsigned int subbuf_size_low, unsigned int n_subbufs_low, |
| 773 | unsigned int subbuf_size_med, unsigned int n_subbufs_med, |
| 774 | unsigned int subbuf_size_high, unsigned int n_subbufs_high) |
| 775 | { |
| 776 | int err = 0; |
| 777 | |
| 778 | err = ltt_trace_setup(trace_name); |
| 779 | if (IS_ERR_VALUE(err)) |
| 780 | return err; |
| 781 | |
| 782 | err = ltt_trace_set_type(trace_name, trace_type); |
| 783 | if (IS_ERR_VALUE(err)) |
| 784 | return err; |
| 785 | |
| 786 | err = ltt_trace_alloc(trace_name); |
| 787 | if (IS_ERR_VALUE(err)) |
| 788 | return err; |
| 789 | |
| 790 | return err; |
| 791 | } |
| 792 | |
| 793 | /* Must be called while sure that trace is in the list. */ |
| 794 | static int _ltt_trace_destroy(struct ltt_trace_struct *trace) |
| 795 | { |
| 796 | int err = -EPERM; |
| 797 | |
| 798 | if (trace == NULL) { |
| 799 | err = -ENOENT; |
| 800 | goto traces_error; |
| 801 | } |
| 802 | if (trace->active) { |
| 803 | printk(KERN_ERR |
| 804 | "LTT : Can't destroy trace %s : tracer is active\n", |
| 805 | trace->trace_name); |
| 806 | err = -EBUSY; |
| 807 | goto active_error; |
| 808 | } |
| 809 | /* Everything went fine */ |
| 810 | //ust// list_del_rcu(&trace->list); |
| 811 | //ust// synchronize_sched(); |
| 812 | if (list_empty(<t_traces.head)) { |
| 813 | //ust// clear_kernel_trace_flag_all_tasks(); |
| 814 | /* |
| 815 | * We stop the asynchronous delivery of reader wakeup, but |
| 816 | * we must make one last check for reader wakeups pending |
| 817 | * later in __ltt_trace_destroy. |
| 818 | */ |
| 819 | //ust// del_timer_sync(<t_async_wakeup_timer); |
| 820 | } |
| 821 | return 0; |
| 822 | |
| 823 | /* error handling */ |
| 824 | active_error: |
| 825 | traces_error: |
| 826 | return err; |
| 827 | } |
| 828 | |
| 829 | /* Sleepable part of the destroy */ |
| 830 | static void __ltt_trace_destroy(struct ltt_trace_struct *trace) |
| 831 | { |
| 832 | int i; |
| 833 | struct ltt_channel_struct *chan; |
| 834 | |
| 835 | for (i = 0; i < trace->nr_channels; i++) { |
| 836 | chan = &trace->channels[i]; |
| 837 | if (chan->active) |
| 838 | trace->ops->finish_channel(chan); |
| 839 | } |
| 840 | |
| 841 | return; /* FIXME: temporary for ust */ |
| 842 | //ust// flush_scheduled_work(); |
| 843 | |
| 844 | /* |
| 845 | * The currently destroyed trace is not in the trace list anymore, |
| 846 | * so it's safe to call the async wakeup ourself. It will deliver |
| 847 | * the last subbuffers. |
| 848 | */ |
| 849 | trace_async_wakeup(trace); |
| 850 | |
| 851 | for (i = 0; i < trace->nr_channels; i++) { |
| 852 | chan = &trace->channels[i]; |
| 853 | if (chan->active) |
| 854 | trace->ops->remove_channel(chan); |
| 855 | } |
| 856 | |
| 857 | kref_put(&trace->ltt_transport_kref, ltt_release_transport); |
| 858 | |
| 859 | //ust// module_put(trace->transport->owner); |
| 860 | |
| 861 | /* |
| 862 | * Wait for lttd readers to release the files, therefore making sure |
| 863 | * the last subbuffers have been read. |
| 864 | */ |
| 865 | //ust// if (atomic_read(&trace->kref.refcount) > 1) { |
| 866 | //ust// int ret = 0; |
| 867 | //ust// __wait_event_interruptible(trace->kref_wq, |
| 868 | //ust// (atomic_read(&trace->kref.refcount) == 1), ret); |
| 869 | //ust// } |
| 870 | kref_put(&trace->kref, ltt_release_trace); |
| 871 | } |
| 872 | |
| 873 | int ltt_trace_destroy(const char *trace_name) |
| 874 | { |
| 875 | int err = 0; |
| 876 | struct ltt_trace_struct *trace; |
| 877 | |
| 878 | ltt_lock_traces(); |
| 879 | |
| 880 | trace = _ltt_trace_find(trace_name); |
| 881 | if (trace) { |
| 882 | err = _ltt_trace_destroy(trace); |
| 883 | if (err) |
| 884 | goto error; |
| 885 | |
| 886 | ltt_unlock_traces(); |
| 887 | |
| 888 | __ltt_trace_destroy(trace); |
| 889 | //ust// put_trace_clock(); |
| 890 | |
| 891 | return 0; |
| 892 | } |
| 893 | |
| 894 | trace = _ltt_trace_find_setup(trace_name); |
| 895 | if (trace) { |
| 896 | _ltt_trace_free(trace); |
| 897 | ltt_unlock_traces(); |
| 898 | return 0; |
| 899 | } |
| 900 | |
| 901 | err = -ENOENT; |
| 902 | |
| 903 | /* Error handling */ |
| 904 | error: |
| 905 | ltt_unlock_traces(); |
| 906 | return err; |
| 907 | } |
| 908 | //ust// EXPORT_SYMBOL_GPL(ltt_trace_destroy); |
| 909 | |
| 910 | /* must be called from within a traces lock. */ |
| 911 | static int _ltt_trace_start(struct ltt_trace_struct *trace) |
| 912 | { |
| 913 | int err = 0; |
| 914 | |
| 915 | if (trace == NULL) { |
| 916 | err = -ENOENT; |
| 917 | goto traces_error; |
| 918 | } |
| 919 | if (trace->active) |
| 920 | printk(KERN_INFO "LTT : Tracing already active for trace %s\n", |
| 921 | trace->trace_name); |
| 922 | //ust// if (!try_module_get(ltt_run_filter_owner)) { |
| 923 | //ust// err = -ENODEV; |
| 924 | //ust// printk(KERN_ERR "LTT : Can't lock filter module.\n"); |
| 925 | //ust// goto get_ltt_run_filter_error; |
| 926 | //ust// } |
| 927 | trace->active = 1; |
| 928 | /* Read by trace points without protection : be careful */ |
| 929 | ltt_traces.num_active_traces++; |
| 930 | return err; |
| 931 | |
| 932 | /* error handling */ |
| 933 | get_ltt_run_filter_error: |
| 934 | traces_error: |
| 935 | return err; |
| 936 | } |
| 937 | |
| 938 | int ltt_trace_start(const char *trace_name) |
| 939 | { |
| 940 | int err = 0; |
| 941 | struct ltt_trace_struct *trace; |
| 942 | |
| 943 | ltt_lock_traces(); |
| 944 | |
| 945 | trace = _ltt_trace_find(trace_name); |
| 946 | err = _ltt_trace_start(trace); |
| 947 | if (err) |
| 948 | goto no_trace; |
| 949 | |
| 950 | ltt_unlock_traces(); |
| 951 | |
| 952 | /* |
| 953 | * Call the kernel state dump. |
| 954 | * Events will be mixed with real kernel events, it's ok. |
| 955 | * Notice that there is no protection on the trace : that's exactly |
| 956 | * why we iterate on the list and check for trace equality instead of |
| 957 | * directly using this trace handle inside the logging function. |
| 958 | */ |
| 959 | |
| 960 | ltt_dump_marker_state(trace); |
| 961 | |
| 962 | //ust// if (!try_module_get(ltt_statedump_owner)) { |
| 963 | //ust// err = -ENODEV; |
| 964 | //ust// printk(KERN_ERR |
| 965 | //ust// "LTT : Can't lock state dump module.\n"); |
| 966 | //ust// } else { |
| 967 | ltt_statedump_functor(trace); |
| 968 | //ust// module_put(ltt_statedump_owner); |
| 969 | //ust// } |
| 970 | |
| 971 | return err; |
| 972 | |
| 973 | /* Error handling */ |
| 974 | no_trace: |
| 975 | ltt_unlock_traces(); |
| 976 | return err; |
| 977 | } |
| 978 | //ust// EXPORT_SYMBOL_GPL(ltt_trace_start); |
| 979 | |
| 980 | /* must be called from within traces lock */ |
| 981 | static int _ltt_trace_stop(struct ltt_trace_struct *trace) |
| 982 | { |
| 983 | int err = -EPERM; |
| 984 | |
| 985 | if (trace == NULL) { |
| 986 | err = -ENOENT; |
| 987 | goto traces_error; |
| 988 | } |
| 989 | if (!trace->active) |
| 990 | printk(KERN_INFO "LTT : Tracing not active for trace %s\n", |
| 991 | trace->trace_name); |
| 992 | if (trace->active) { |
| 993 | trace->active = 0; |
| 994 | ltt_traces.num_active_traces--; |
| 995 | //ust// synchronize_sched(); /* Wait for each tracing to be finished */ |
| 996 | } |
| 997 | //ust// module_put(ltt_run_filter_owner); |
| 998 | /* Everything went fine */ |
| 999 | return 0; |
| 1000 | |
| 1001 | /* Error handling */ |
| 1002 | traces_error: |
| 1003 | return err; |
| 1004 | } |
| 1005 | |
| 1006 | int ltt_trace_stop(const char *trace_name) |
| 1007 | { |
| 1008 | int err = 0; |
| 1009 | struct ltt_trace_struct *trace; |
| 1010 | |
| 1011 | ltt_lock_traces(); |
| 1012 | trace = _ltt_trace_find(trace_name); |
| 1013 | err = _ltt_trace_stop(trace); |
| 1014 | ltt_unlock_traces(); |
| 1015 | return err; |
| 1016 | } |
| 1017 | //ust// EXPORT_SYMBOL_GPL(ltt_trace_stop); |
| 1018 | |
| 1019 | /** |
| 1020 | * ltt_control - Trace control in-kernel API |
| 1021 | * @msg: Action to perform |
| 1022 | * @trace_name: Trace on which the action must be done |
| 1023 | * @trace_type: Type of trace (normal, flight, hybrid) |
| 1024 | * @args: Arguments specific to the action |
| 1025 | */ |
| 1026 | //ust// int ltt_control(enum ltt_control_msg msg, const char *trace_name, |
| 1027 | //ust// const char *trace_type, union ltt_control_args args) |
| 1028 | //ust// { |
| 1029 | //ust// int err = -EPERM; |
| 1030 | //ust// |
| 1031 | //ust// printk(KERN_ALERT "ltt_control : trace %s\n", trace_name); |
| 1032 | //ust// switch (msg) { |
| 1033 | //ust// case LTT_CONTROL_START: |
| 1034 | //ust// printk(KERN_DEBUG "Start tracing %s\n", trace_name); |
| 1035 | //ust// err = ltt_trace_start(trace_name); |
| 1036 | //ust// break; |
| 1037 | //ust// case LTT_CONTROL_STOP: |
| 1038 | //ust// printk(KERN_DEBUG "Stop tracing %s\n", trace_name); |
| 1039 | //ust// err = ltt_trace_stop(trace_name); |
| 1040 | //ust// break; |
| 1041 | //ust// case LTT_CONTROL_CREATE_TRACE: |
| 1042 | //ust// printk(KERN_DEBUG "Creating trace %s\n", trace_name); |
| 1043 | //ust// err = ltt_trace_create(trace_name, trace_type, |
| 1044 | //ust// args.new_trace.mode, |
| 1045 | //ust// args.new_trace.subbuf_size_low, |
| 1046 | //ust// args.new_trace.n_subbufs_low, |
| 1047 | //ust// args.new_trace.subbuf_size_med, |
| 1048 | //ust// args.new_trace.n_subbufs_med, |
| 1049 | //ust// args.new_trace.subbuf_size_high, |
| 1050 | //ust// args.new_trace.n_subbufs_high); |
| 1051 | //ust// break; |
| 1052 | //ust// case LTT_CONTROL_DESTROY_TRACE: |
| 1053 | //ust// printk(KERN_DEBUG "Destroying trace %s\n", trace_name); |
| 1054 | //ust// err = ltt_trace_destroy(trace_name); |
| 1055 | //ust// break; |
| 1056 | //ust// } |
| 1057 | //ust// return err; |
| 1058 | //ust// } |
| 1059 | //ust// EXPORT_SYMBOL_GPL(ltt_control); |
| 1060 | |
| 1061 | /** |
| 1062 | * ltt_filter_control - Trace filter control in-kernel API |
| 1063 | * @msg: Action to perform on the filter |
| 1064 | * @trace_name: Trace on which the action must be done |
| 1065 | */ |
| 1066 | int ltt_filter_control(enum ltt_filter_control_msg msg, const char *trace_name) |
| 1067 | { |
| 1068 | int err; |
| 1069 | struct ltt_trace_struct *trace; |
| 1070 | |
| 1071 | printk(KERN_DEBUG "ltt_filter_control : trace %s\n", trace_name); |
| 1072 | ltt_lock_traces(); |
| 1073 | trace = _ltt_trace_find(trace_name); |
| 1074 | if (trace == NULL) { |
| 1075 | printk(KERN_ALERT |
| 1076 | "Trace does not exist. Cannot proxy control request\n"); |
| 1077 | err = -ENOENT; |
| 1078 | goto trace_error; |
| 1079 | } |
| 1080 | //ust// if (!try_module_get(ltt_filter_control_owner)) { |
| 1081 | //ust// err = -ENODEV; |
| 1082 | //ust// goto get_module_error; |
| 1083 | //ust// } |
| 1084 | switch (msg) { |
| 1085 | case LTT_FILTER_DEFAULT_ACCEPT: |
| 1086 | printk(KERN_DEBUG |
| 1087 | "Proxy filter default accept %s\n", trace_name); |
| 1088 | err = (*ltt_filter_control_functor)(msg, trace); |
| 1089 | break; |
| 1090 | case LTT_FILTER_DEFAULT_REJECT: |
| 1091 | printk(KERN_DEBUG |
| 1092 | "Proxy filter default reject %s\n", trace_name); |
| 1093 | err = (*ltt_filter_control_functor)(msg, trace); |
| 1094 | break; |
| 1095 | default: |
| 1096 | err = -EPERM; |
| 1097 | } |
| 1098 | //ust// module_put(ltt_filter_control_owner); |
| 1099 | |
| 1100 | get_module_error: |
| 1101 | trace_error: |
| 1102 | ltt_unlock_traces(); |
| 1103 | return err; |
| 1104 | } |
| 1105 | //ust// EXPORT_SYMBOL_GPL(ltt_filter_control); |
| 1106 | |
| 1107 | //ust// int __init ltt_init(void) |
| 1108 | //ust// { |
| 1109 | //ust// /* Make sure no page fault can be triggered by this module */ |
| 1110 | //ust// vmalloc_sync_all(); |
| 1111 | //ust// return 0; |
| 1112 | //ust// } |
| 1113 | |
| 1114 | //ust// module_init(ltt_init) |
| 1115 | |
| 1116 | //ust// static void __exit ltt_exit(void) |
| 1117 | //ust// { |
| 1118 | //ust// struct ltt_trace_struct *trace; |
| 1119 | //ust// struct list_head *pos, *n; |
| 1120 | //ust// |
| 1121 | //ust// ltt_lock_traces(); |
| 1122 | //ust// /* Stop each trace, currently being read by RCU read-side */ |
| 1123 | //ust// list_for_each_entry_rcu(trace, <t_traces.head, list) |
| 1124 | //ust// _ltt_trace_stop(trace); |
| 1125 | //ust// /* Wait for quiescent state. Readers have preemption disabled. */ |
| 1126 | //ust// synchronize_sched(); |
| 1127 | //ust// /* Safe iteration is now permitted. It does not have to be RCU-safe |
| 1128 | //ust// * because no readers are left. */ |
| 1129 | //ust// list_for_each_safe(pos, n, <t_traces.head) { |
| 1130 | //ust// trace = container_of(pos, struct ltt_trace_struct, list); |
| 1131 | //ust// /* _ltt_trace_destroy does a synchronize_sched() */ |
| 1132 | //ust// _ltt_trace_destroy(trace); |
| 1133 | //ust// __ltt_trace_destroy(trace); |
| 1134 | //ust// } |
| 1135 | //ust// /* free traces in pre-alloc status */ |
| 1136 | //ust// list_for_each_safe(pos, n, <t_traces.setup_head) { |
| 1137 | //ust// trace = container_of(pos, struct ltt_trace_struct, list); |
| 1138 | //ust// _ltt_trace_free(trace); |
| 1139 | //ust// } |
| 1140 | //ust// |
| 1141 | //ust// ltt_unlock_traces(); |
| 1142 | //ust// } |
| 1143 | |
| 1144 | //ust// module_exit(ltt_exit) |
| 1145 | |
| 1146 | //ust// MODULE_LICENSE("GPL"); |
| 1147 | //ust// MODULE_AUTHOR("Mathieu Desnoyers"); |
| 1148 | //ust// MODULE_DESCRIPTION("Linux Trace Toolkit Next Generation Tracer Kernel API"); |