| 1 | /* |
| 2 | * Copyright (C) 2007 Mathieu Desnoyers |
| 3 | * |
| 4 | * This library is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU Lesser General Public |
| 6 | * License as published by the Free Software Foundation; either |
| 7 | * version 2.1 of the License, or (at your option) any later version. |
| 8 | * |
| 9 | * This library 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 GNU |
| 12 | * Lesser General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU Lesser General Public |
| 15 | * License along with this library; if not, write to the Free Software |
| 16 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 17 | */ |
| 18 | |
| 19 | #include <stdlib.h> |
| 20 | #include <errno.h> |
| 21 | #define _LGPL_SOURCE |
| 22 | #include <urcu-bp.h> |
| 23 | #include <urcu/rculist.h> |
| 24 | #include <urcu/hlist.h> |
| 25 | |
| 26 | #include <ust/core.h> |
| 27 | #include <ust/marker.h> |
| 28 | #include <ust/tracepoint.h> |
| 29 | |
| 30 | #include "usterr.h" |
| 31 | #include "channels.h" |
| 32 | #include "tracercore.h" |
| 33 | #include "tracer.h" |
| 34 | |
| 35 | __thread long ust_reg_stack[500]; |
| 36 | volatile __thread long *ust_reg_stack_ptr = (long *) 0; |
| 37 | |
| 38 | extern struct marker * const __start___markers_ptrs[] __attribute__((visibility("hidden"))); |
| 39 | extern struct marker * const __stop___markers_ptrs[] __attribute__((visibility("hidden"))); |
| 40 | |
| 41 | /* Set to 1 to enable marker debug output */ |
| 42 | static const int marker_debug; |
| 43 | |
| 44 | /* |
| 45 | * markers_mutex nests inside module_mutex. Markers mutex protects the builtin |
| 46 | * and module markers and the hash table. |
| 47 | */ |
| 48 | static DEFINE_MUTEX(markers_mutex); |
| 49 | |
| 50 | static CDS_LIST_HEAD(libs); |
| 51 | |
| 52 | |
| 53 | void lock_markers(void) |
| 54 | { |
| 55 | pthread_mutex_lock(&markers_mutex); |
| 56 | } |
| 57 | |
| 58 | void unlock_markers(void) |
| 59 | { |
| 60 | pthread_mutex_unlock(&markers_mutex); |
| 61 | } |
| 62 | |
| 63 | /* |
| 64 | * Marker hash table, containing the active markers. |
| 65 | * Protected by module_mutex. |
| 66 | */ |
| 67 | #define MARKER_HASH_BITS 6 |
| 68 | #define MARKER_TABLE_SIZE (1 << MARKER_HASH_BITS) |
| 69 | static struct cds_hlist_head marker_table[MARKER_TABLE_SIZE]; |
| 70 | |
| 71 | /* |
| 72 | * Note about RCU : |
| 73 | * It is used to make sure every handler has finished using its private data |
| 74 | * between two consecutive operation (add or remove) on a given marker. It is |
| 75 | * also used to delay the free of multiple probes array until a quiescent state |
| 76 | * is reached. |
| 77 | * marker entries modifications are protected by the markers_mutex. |
| 78 | */ |
| 79 | struct marker_entry { |
| 80 | struct cds_hlist_node hlist; |
| 81 | char *format; |
| 82 | char *name; |
| 83 | /* Probe wrapper */ |
| 84 | void (*call)(const struct marker *mdata, void *call_private, struct registers *regs, ...); |
| 85 | struct marker_probe_closure single; |
| 86 | struct marker_probe_closure *multi; |
| 87 | int refcount; /* Number of times armed. 0 if disarmed. */ |
| 88 | struct rcu_head rcu; |
| 89 | void *oldptr; |
| 90 | int rcu_pending; |
| 91 | u16 channel_id; |
| 92 | u16 event_id; |
| 93 | unsigned char ptype:1; |
| 94 | unsigned char format_allocated:1; |
| 95 | char channel[0]; /* Contains channel'\0'name'\0'format'\0' */ |
| 96 | }; |
| 97 | |
| 98 | #ifdef CONFIG_MARKERS_USERSPACE |
| 99 | static void marker_update_processes(void); |
| 100 | #else |
| 101 | static void marker_update_processes(void) |
| 102 | { |
| 103 | } |
| 104 | #endif |
| 105 | |
| 106 | /** |
| 107 | * __mark_empty_function - Empty probe callback |
| 108 | * @mdata: marker data |
| 109 | * @probe_private: probe private data |
| 110 | * @call_private: call site private data |
| 111 | * @fmt: format string |
| 112 | * @...: variable argument list |
| 113 | * |
| 114 | * Empty callback provided as a probe to the markers. By providing this to a |
| 115 | * disabled marker, we make sure the execution flow is always valid even |
| 116 | * though the function pointer change and the marker enabling are two distinct |
| 117 | * operations that modifies the execution flow of preemptible code. |
| 118 | */ |
| 119 | notrace void __mark_empty_function(const struct marker *mdata, |
| 120 | void *probe_private, struct registers *regs, void *call_private, const char *fmt, va_list *args) |
| 121 | { |
| 122 | } |
| 123 | //ust// EXPORT_SYMBOL_GPL(__mark_empty_function); |
| 124 | |
| 125 | /* |
| 126 | * marker_probe_cb Callback that prepares the variable argument list for probes. |
| 127 | * @mdata: pointer of type struct marker |
| 128 | * @call_private: caller site private data |
| 129 | * @...: Variable argument list. |
| 130 | * |
| 131 | * Since we do not use "typical" pointer based RCU in the 1 argument case, we |
| 132 | * need to put a full cmm_smp_rmb() in this branch. This is why we do not use |
| 133 | * rcu_dereference() for the pointer read. |
| 134 | */ |
| 135 | notrace void marker_probe_cb(const struct marker *mdata, |
| 136 | void *call_private, struct registers *regs, ...) |
| 137 | { |
| 138 | va_list args; |
| 139 | char ptype; |
| 140 | |
| 141 | /* |
| 142 | * rcu_read_lock_sched does two things : disabling preemption to make |
| 143 | * sure the teardown of the callbacks can be done correctly when they |
| 144 | * are in modules and they insure RCU read coherency. |
| 145 | */ |
| 146 | //ust// rcu_read_lock_sched_notrace(); |
| 147 | ptype = mdata->ptype; |
| 148 | if (likely(!ptype)) { |
| 149 | marker_probe_func *func; |
| 150 | /* Must read the ptype before ptr. They are not data dependant, |
| 151 | * so we put an explicit cmm_smp_rmb() here. */ |
| 152 | cmm_smp_rmb(); |
| 153 | func = mdata->single.func; |
| 154 | /* Must read the ptr before private data. They are not data |
| 155 | * dependant, so we put an explicit cmm_smp_rmb() here. */ |
| 156 | cmm_smp_rmb(); |
| 157 | va_start(args, regs); |
| 158 | func(mdata, mdata->single.probe_private, regs, call_private, |
| 159 | mdata->format, &args); |
| 160 | va_end(args); |
| 161 | } else { |
| 162 | struct marker_probe_closure *multi; |
| 163 | int i; |
| 164 | /* |
| 165 | * Read mdata->ptype before mdata->multi. |
| 166 | */ |
| 167 | cmm_smp_rmb(); |
| 168 | multi = mdata->multi; |
| 169 | /* |
| 170 | * multi points to an array, therefore accessing the array |
| 171 | * depends on reading multi. However, even in this case, |
| 172 | * we must insure that the pointer is read _before_ the array |
| 173 | * data. Same as rcu_dereference, but we need a full cmm_smp_rmb() |
| 174 | * in the fast path, so put the explicit cmm_barrier here. |
| 175 | */ |
| 176 | cmm_smp_read_barrier_depends(); |
| 177 | for (i = 0; multi[i].func; i++) { |
| 178 | va_start(args, regs); |
| 179 | multi[i].func(mdata, multi[i].probe_private, |
| 180 | regs, call_private, mdata->format, &args); |
| 181 | va_end(args); |
| 182 | } |
| 183 | } |
| 184 | //ust// rcu_read_unlock_sched_notrace(); |
| 185 | } |
| 186 | //ust// EXPORT_SYMBOL_GPL(marker_probe_cb); |
| 187 | |
| 188 | /* |
| 189 | * marker_probe_cb Callback that does not prepare the variable argument list. |
| 190 | * @mdata: pointer of type struct marker |
| 191 | * @call_private: caller site private data |
| 192 | * @...: Variable argument list. |
| 193 | * |
| 194 | * Should be connected to markers "MARK_NOARGS". |
| 195 | */ |
| 196 | static notrace void marker_probe_cb_noarg(const struct marker *mdata, |
| 197 | void *call_private, struct registers *regs, ...) |
| 198 | { |
| 199 | va_list args; /* not initialized */ |
| 200 | char ptype; |
| 201 | |
| 202 | //ust// rcu_read_lock_sched_notrace(); |
| 203 | ptype = mdata->ptype; |
| 204 | if (likely(!ptype)) { |
| 205 | marker_probe_func *func; |
| 206 | /* Must read the ptype before ptr. They are not data dependant, |
| 207 | * so we put an explicit cmm_smp_rmb() here. */ |
| 208 | cmm_smp_rmb(); |
| 209 | func = mdata->single.func; |
| 210 | /* Must read the ptr before private data. They are not data |
| 211 | * dependant, so we put an explicit cmm_smp_rmb() here. */ |
| 212 | cmm_smp_rmb(); |
| 213 | func(mdata, mdata->single.probe_private, regs, call_private, |
| 214 | mdata->format, &args); |
| 215 | } else { |
| 216 | struct marker_probe_closure *multi; |
| 217 | int i; |
| 218 | /* |
| 219 | * Read mdata->ptype before mdata->multi. |
| 220 | */ |
| 221 | cmm_smp_rmb(); |
| 222 | multi = mdata->multi; |
| 223 | /* |
| 224 | * multi points to an array, therefore accessing the array |
| 225 | * depends on reading multi. However, even in this case, |
| 226 | * we must insure that the pointer is read _before_ the array |
| 227 | * data. Same as rcu_dereference, but we need a full cmm_smp_rmb() |
| 228 | * in the fast path, so put the explicit cmm_barrier here. |
| 229 | */ |
| 230 | cmm_smp_read_barrier_depends(); |
| 231 | for (i = 0; multi[i].func; i++) |
| 232 | multi[i].func(mdata, multi[i].probe_private, regs, |
| 233 | call_private, mdata->format, &args); |
| 234 | } |
| 235 | //ust// rcu_read_unlock_sched_notrace(); |
| 236 | } |
| 237 | |
| 238 | static void free_old_closure(struct rcu_head *head) |
| 239 | { |
| 240 | struct marker_entry *entry = _ust_container_of(head, |
| 241 | struct marker_entry, rcu); |
| 242 | free(entry->oldptr); |
| 243 | /* Make sure we free the data before setting the pending flag to 0 */ |
| 244 | cmm_smp_wmb(); |
| 245 | entry->rcu_pending = 0; |
| 246 | } |
| 247 | |
| 248 | static void debug_print_probes(struct marker_entry *entry) |
| 249 | { |
| 250 | int i; |
| 251 | |
| 252 | if (!marker_debug) |
| 253 | return; |
| 254 | |
| 255 | if (!entry->ptype) { |
| 256 | DBG("Single probe : %p %p", |
| 257 | entry->single.func, |
| 258 | entry->single.probe_private); |
| 259 | } else { |
| 260 | for (i = 0; entry->multi[i].func; i++) |
| 261 | DBG("Multi probe %d : %p %p", i, |
| 262 | entry->multi[i].func, |
| 263 | entry->multi[i].probe_private); |
| 264 | } |
| 265 | } |
| 266 | |
| 267 | static struct marker_probe_closure * |
| 268 | marker_entry_add_probe(struct marker_entry *entry, |
| 269 | marker_probe_func *probe, void *probe_private) |
| 270 | { |
| 271 | int nr_probes = 0; |
| 272 | struct marker_probe_closure *old, *new; |
| 273 | |
| 274 | WARN_ON(!probe); |
| 275 | |
| 276 | debug_print_probes(entry); |
| 277 | old = entry->multi; |
| 278 | if (!entry->ptype) { |
| 279 | if (entry->single.func == probe && |
| 280 | entry->single.probe_private == probe_private) |
| 281 | return ERR_PTR(-EBUSY); |
| 282 | if (entry->single.func == __mark_empty_function) { |
| 283 | /* 0 -> 1 probes */ |
| 284 | entry->single.func = probe; |
| 285 | entry->single.probe_private = probe_private; |
| 286 | entry->refcount = 1; |
| 287 | entry->ptype = 0; |
| 288 | debug_print_probes(entry); |
| 289 | return NULL; |
| 290 | } else { |
| 291 | /* 1 -> 2 probes */ |
| 292 | nr_probes = 1; |
| 293 | old = NULL; |
| 294 | } |
| 295 | } else { |
| 296 | /* (N -> N+1), (N != 0, 1) probes */ |
| 297 | for (nr_probes = 0; old[nr_probes].func; nr_probes++) |
| 298 | if (old[nr_probes].func == probe |
| 299 | && old[nr_probes].probe_private |
| 300 | == probe_private) |
| 301 | return ERR_PTR(-EBUSY); |
| 302 | } |
| 303 | /* + 2 : one for new probe, one for NULL func */ |
| 304 | new = zmalloc((nr_probes + 2) * sizeof(struct marker_probe_closure)); |
| 305 | if (new == NULL) |
| 306 | return ERR_PTR(-ENOMEM); |
| 307 | if (!old) |
| 308 | new[0] = entry->single; |
| 309 | else |
| 310 | memcpy(new, old, |
| 311 | nr_probes * sizeof(struct marker_probe_closure)); |
| 312 | new[nr_probes].func = probe; |
| 313 | new[nr_probes].probe_private = probe_private; |
| 314 | entry->refcount = nr_probes + 1; |
| 315 | entry->multi = new; |
| 316 | entry->ptype = 1; |
| 317 | debug_print_probes(entry); |
| 318 | return old; |
| 319 | } |
| 320 | |
| 321 | static struct marker_probe_closure * |
| 322 | marker_entry_remove_probe(struct marker_entry *entry, |
| 323 | marker_probe_func *probe, void *probe_private) |
| 324 | { |
| 325 | int nr_probes = 0, nr_del = 0, i; |
| 326 | struct marker_probe_closure *old, *new; |
| 327 | |
| 328 | old = entry->multi; |
| 329 | |
| 330 | debug_print_probes(entry); |
| 331 | if (!entry->ptype) { |
| 332 | /* 0 -> N is an error */ |
| 333 | WARN_ON(entry->single.func == __mark_empty_function); |
| 334 | /* 1 -> 0 probes */ |
| 335 | WARN_ON(probe && entry->single.func != probe); |
| 336 | WARN_ON(entry->single.probe_private != probe_private); |
| 337 | entry->single.func = __mark_empty_function; |
| 338 | entry->refcount = 0; |
| 339 | entry->ptype = 0; |
| 340 | debug_print_probes(entry); |
| 341 | return NULL; |
| 342 | } else { |
| 343 | /* (N -> M), (N > 1, M >= 0) probes */ |
| 344 | for (nr_probes = 0; old[nr_probes].func; nr_probes++) { |
| 345 | if ((!probe || old[nr_probes].func == probe) |
| 346 | && old[nr_probes].probe_private |
| 347 | == probe_private) |
| 348 | nr_del++; |
| 349 | } |
| 350 | } |
| 351 | |
| 352 | if (nr_probes - nr_del == 0) { |
| 353 | /* N -> 0, (N > 1) */ |
| 354 | entry->single.func = __mark_empty_function; |
| 355 | entry->refcount = 0; |
| 356 | entry->ptype = 0; |
| 357 | } else if (nr_probes - nr_del == 1) { |
| 358 | /* N -> 1, (N > 1) */ |
| 359 | for (i = 0; old[i].func; i++) |
| 360 | if ((probe && old[i].func != probe) || |
| 361 | old[i].probe_private != probe_private) |
| 362 | entry->single = old[i]; |
| 363 | entry->refcount = 1; |
| 364 | entry->ptype = 0; |
| 365 | } else { |
| 366 | int j = 0; |
| 367 | /* N -> M, (N > 1, M > 1) */ |
| 368 | /* + 1 for NULL */ |
| 369 | new = zmalloc((nr_probes - nr_del + 1) * sizeof(struct marker_probe_closure)); |
| 370 | if (new == NULL) |
| 371 | return ERR_PTR(-ENOMEM); |
| 372 | for (i = 0; old[i].func; i++) |
| 373 | if ((probe && old[i].func != probe) || |
| 374 | old[i].probe_private != probe_private) |
| 375 | new[j++] = old[i]; |
| 376 | entry->refcount = nr_probes - nr_del; |
| 377 | entry->ptype = 1; |
| 378 | entry->multi = new; |
| 379 | } |
| 380 | debug_print_probes(entry); |
| 381 | return old; |
| 382 | } |
| 383 | |
| 384 | /* |
| 385 | * Get marker if the marker is present in the marker hash table. |
| 386 | * Must be called with markers_mutex held. |
| 387 | * Returns NULL if not present. |
| 388 | */ |
| 389 | static struct marker_entry *get_marker(const char *channel, const char *name) |
| 390 | { |
| 391 | struct cds_hlist_head *head; |
| 392 | struct cds_hlist_node *node; |
| 393 | struct marker_entry *e; |
| 394 | size_t channel_len = strlen(channel) + 1; |
| 395 | size_t name_len = strlen(name) + 1; |
| 396 | u32 hash; |
| 397 | |
| 398 | hash = jhash(channel, channel_len-1, 0) ^ jhash(name, name_len-1, 0); |
| 399 | head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; |
| 400 | cds_hlist_for_each_entry(e, node, head, hlist) { |
| 401 | if (!strcmp(channel, e->channel) && !strcmp(name, e->name)) |
| 402 | return e; |
| 403 | } |
| 404 | return NULL; |
| 405 | } |
| 406 | |
| 407 | /* |
| 408 | * Add the marker to the marker hash table. Must be called with markers_mutex |
| 409 | * held. |
| 410 | */ |
| 411 | static struct marker_entry *add_marker(const char *channel, const char *name, |
| 412 | const char *format) |
| 413 | { |
| 414 | struct cds_hlist_head *head; |
| 415 | struct cds_hlist_node *node; |
| 416 | struct marker_entry *e; |
| 417 | size_t channel_len = strlen(channel) + 1; |
| 418 | size_t name_len = strlen(name) + 1; |
| 419 | size_t format_len = 0; |
| 420 | u32 hash; |
| 421 | |
| 422 | hash = jhash(channel, channel_len-1, 0) ^ jhash(name, name_len-1, 0); |
| 423 | if (format) |
| 424 | format_len = strlen(format) + 1; |
| 425 | head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; |
| 426 | cds_hlist_for_each_entry(e, node, head, hlist) { |
| 427 | if (!strcmp(channel, e->channel) && !strcmp(name, e->name)) { |
| 428 | DBG("Marker %s.%s busy", channel, name); |
| 429 | return ERR_PTR(-EBUSY); /* Already there */ |
| 430 | } |
| 431 | } |
| 432 | /* |
| 433 | * Using zmalloc here to allocate a variable length element. Could |
| 434 | * cause some memory fragmentation if overused. |
| 435 | */ |
| 436 | e = zmalloc(sizeof(struct marker_entry) |
| 437 | + channel_len + name_len + format_len); |
| 438 | if (!e) |
| 439 | return ERR_PTR(-ENOMEM); |
| 440 | memcpy(e->channel, channel, channel_len); |
| 441 | e->name = &e->channel[channel_len]; |
| 442 | memcpy(e->name, name, name_len); |
| 443 | if (format) { |
| 444 | e->format = &e->name[name_len]; |
| 445 | memcpy(e->format, format, format_len); |
| 446 | if (strcmp(e->format, MARK_NOARGS) == 0) |
| 447 | e->call = marker_probe_cb_noarg; |
| 448 | else |
| 449 | e->call = marker_probe_cb; |
| 450 | trace_mark(metadata, core_marker_format, |
| 451 | "channel %s name %s format %s", |
| 452 | e->channel, e->name, e->format); |
| 453 | } else { |
| 454 | e->format = NULL; |
| 455 | e->call = marker_probe_cb; |
| 456 | } |
| 457 | e->single.func = __mark_empty_function; |
| 458 | e->single.probe_private = NULL; |
| 459 | e->multi = NULL; |
| 460 | e->ptype = 0; |
| 461 | e->format_allocated = 0; |
| 462 | e->refcount = 0; |
| 463 | e->rcu_pending = 0; |
| 464 | cds_hlist_add_head(&e->hlist, head); |
| 465 | return e; |
| 466 | } |
| 467 | |
| 468 | /* |
| 469 | * Remove the marker from the marker hash table. Must be called with mutex_lock |
| 470 | * held. |
| 471 | */ |
| 472 | static int remove_marker(const char *channel, const char *name) |
| 473 | { |
| 474 | struct cds_hlist_head *head; |
| 475 | struct cds_hlist_node *node; |
| 476 | struct marker_entry *e; |
| 477 | int found = 0; |
| 478 | size_t channel_len = strlen(channel) + 1; |
| 479 | size_t name_len = strlen(name) + 1; |
| 480 | u32 hash; |
| 481 | int ret; |
| 482 | |
| 483 | hash = jhash(channel, channel_len-1, 0) ^ jhash(name, name_len-1, 0); |
| 484 | head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; |
| 485 | cds_hlist_for_each_entry(e, node, head, hlist) { |
| 486 | if (!strcmp(channel, e->channel) && !strcmp(name, e->name)) { |
| 487 | found = 1; |
| 488 | break; |
| 489 | } |
| 490 | } |
| 491 | if (!found) |
| 492 | return -ENOENT; |
| 493 | if (e->single.func != __mark_empty_function) |
| 494 | return -EBUSY; |
| 495 | cds_hlist_del(&e->hlist); |
| 496 | if (e->format_allocated) |
| 497 | free(e->format); |
| 498 | ret = ltt_channels_unregister(e->channel); |
| 499 | WARN_ON(ret); |
| 500 | /* Make sure the call_rcu has been executed */ |
| 501 | //ust// if (e->rcu_pending) |
| 502 | //ust// rcu_cmm_barrier_sched(); |
| 503 | free(e); |
| 504 | return 0; |
| 505 | } |
| 506 | |
| 507 | /* |
| 508 | * Set the mark_entry format to the format found in the element. |
| 509 | */ |
| 510 | static int marker_set_format(struct marker_entry *entry, const char *format) |
| 511 | { |
| 512 | entry->format = strdup(format); |
| 513 | if (!entry->format) |
| 514 | return -ENOMEM; |
| 515 | entry->format_allocated = 1; |
| 516 | |
| 517 | trace_mark(metadata, core_marker_format, |
| 518 | "channel %s name %s format %s", |
| 519 | entry->channel, entry->name, entry->format); |
| 520 | return 0; |
| 521 | } |
| 522 | |
| 523 | /* |
| 524 | * Sets the probe callback corresponding to one marker. |
| 525 | */ |
| 526 | static int set_marker(struct marker_entry *entry, struct marker *elem, |
| 527 | int active) |
| 528 | { |
| 529 | int ret = 0; |
| 530 | WARN_ON(strcmp(entry->name, elem->name) != 0); |
| 531 | |
| 532 | if (entry->format) { |
| 533 | if (strcmp(entry->format, elem->format) != 0) { |
| 534 | ERR("Format mismatch for probe %s (%s), marker (%s)", |
| 535 | entry->name, |
| 536 | entry->format, |
| 537 | elem->format); |
| 538 | return -EPERM; |
| 539 | } |
| 540 | } else { |
| 541 | ret = marker_set_format(entry, elem->format); |
| 542 | if (ret) |
| 543 | return ret; |
| 544 | } |
| 545 | |
| 546 | /* |
| 547 | * probe_cb setup (statically known) is done here. It is |
| 548 | * asynchronous with the rest of execution, therefore we only |
| 549 | * pass from a "safe" callback (with argument) to an "unsafe" |
| 550 | * callback (does not set arguments). |
| 551 | */ |
| 552 | elem->call = entry->call; |
| 553 | elem->channel_id = entry->channel_id; |
| 554 | elem->event_id = entry->event_id; |
| 555 | /* |
| 556 | * Sanity check : |
| 557 | * We only update the single probe private data when the ptr is |
| 558 | * set to a _non_ single probe! (0 -> 1 and N -> 1, N != 1) |
| 559 | */ |
| 560 | WARN_ON(elem->single.func != __mark_empty_function |
| 561 | && elem->single.probe_private != entry->single.probe_private |
| 562 | && !elem->ptype); |
| 563 | elem->single.probe_private = entry->single.probe_private; |
| 564 | /* |
| 565 | * Make sure the private data is valid when we update the |
| 566 | * single probe ptr. |
| 567 | */ |
| 568 | cmm_smp_wmb(); |
| 569 | elem->single.func = entry->single.func; |
| 570 | /* |
| 571 | * We also make sure that the new probe callbacks array is consistent |
| 572 | * before setting a pointer to it. |
| 573 | */ |
| 574 | rcu_assign_pointer(elem->multi, entry->multi); |
| 575 | /* |
| 576 | * Update the function or multi probe array pointer before setting the |
| 577 | * ptype. |
| 578 | */ |
| 579 | cmm_smp_wmb(); |
| 580 | elem->ptype = entry->ptype; |
| 581 | |
| 582 | if (elem->tp_name && (active ^ _imv_read(elem->state))) { |
| 583 | WARN_ON(!elem->tp_cb); |
| 584 | /* |
| 585 | * It is ok to directly call the probe registration because type |
| 586 | * checking has been done in the __trace_mark_tp() macro. |
| 587 | */ |
| 588 | |
| 589 | if (active) { |
| 590 | /* |
| 591 | * try_module_get should always succeed because we hold |
| 592 | * markers_mutex to get the tp_cb address. |
| 593 | */ |
| 594 | //ust// ret = try_module_get(__module_text_address( |
| 595 | //ust// (unsigned long)elem->tp_cb)); |
| 596 | //ust// BUG_ON(!ret); |
| 597 | ret = tracepoint_probe_register_noupdate( |
| 598 | elem->tp_name, |
| 599 | elem->tp_cb, NULL); |
| 600 | } else { |
| 601 | ret = tracepoint_probe_unregister_noupdate( |
| 602 | elem->tp_name, |
| 603 | elem->tp_cb, NULL); |
| 604 | /* |
| 605 | * tracepoint_probe_update_all() must be called |
| 606 | * before the module containing tp_cb is unloaded. |
| 607 | */ |
| 608 | //ust// module_put(__module_text_address( |
| 609 | //ust// (unsigned long)elem->tp_cb)); |
| 610 | } |
| 611 | } |
| 612 | elem->state__imv = active; |
| 613 | |
| 614 | return ret; |
| 615 | } |
| 616 | |
| 617 | /* |
| 618 | * Disable a marker and its probe callback. |
| 619 | * Note: only waiting an RCU period after setting elem->call to the empty |
| 620 | * function insures that the original callback is not used anymore. This insured |
| 621 | * by rcu_read_lock_sched around the call site. |
| 622 | */ |
| 623 | static void disable_marker(struct marker *elem) |
| 624 | { |
| 625 | int ret; |
| 626 | |
| 627 | /* leave "call" as is. It is known statically. */ |
| 628 | if (elem->tp_name && _imv_read(elem->state)) { |
| 629 | WARN_ON(!elem->tp_cb); |
| 630 | /* |
| 631 | * It is ok to directly call the probe registration because type |
| 632 | * checking has been done in the __trace_mark_tp() macro. |
| 633 | */ |
| 634 | ret = tracepoint_probe_unregister_noupdate(elem->tp_name, |
| 635 | elem->tp_cb, NULL); |
| 636 | WARN_ON(ret); |
| 637 | /* |
| 638 | * tracepoint_probe_update_all() must be called |
| 639 | * before the module containing tp_cb is unloaded. |
| 640 | */ |
| 641 | //ust// module_put(__module_text_address((unsigned long)elem->tp_cb)); |
| 642 | } |
| 643 | elem->state__imv = 0; |
| 644 | elem->single.func = __mark_empty_function; |
| 645 | /* Update the function before setting the ptype */ |
| 646 | cmm_smp_wmb(); |
| 647 | elem->ptype = 0; /* single probe */ |
| 648 | /* |
| 649 | * Leave the private data and channel_id/event_id there, because removal |
| 650 | * is racy and should be done only after an RCU period. These are never |
| 651 | * used until the next initialization anyway. |
| 652 | */ |
| 653 | } |
| 654 | |
| 655 | /* |
| 656 | * is_marker_enabled - Check if a marker is enabled |
| 657 | * @channel: channel name |
| 658 | * @name: marker name |
| 659 | * |
| 660 | * Returns 1 if the marker is enabled, 0 if disabled. |
| 661 | */ |
| 662 | int is_marker_enabled(const char *channel, const char *name) |
| 663 | { |
| 664 | struct marker_entry *entry; |
| 665 | |
| 666 | pthread_mutex_lock(&markers_mutex); |
| 667 | entry = get_marker(channel, name); |
| 668 | pthread_mutex_unlock(&markers_mutex); |
| 669 | |
| 670 | return entry && !!entry->refcount; |
| 671 | } |
| 672 | |
| 673 | /** |
| 674 | * marker_update_probe_range - Update a probe range |
| 675 | * @begin: beginning of the range |
| 676 | * @end: end of the range |
| 677 | * |
| 678 | * Updates the probe callback corresponding to a range of markers. |
| 679 | */ |
| 680 | void marker_update_probe_range(struct marker * const *begin, |
| 681 | struct marker * const *end) |
| 682 | { |
| 683 | struct marker * const *iter; |
| 684 | struct marker_entry *mark_entry; |
| 685 | |
| 686 | pthread_mutex_lock(&markers_mutex); |
| 687 | for (iter = begin; iter < end; iter++) { |
| 688 | if (!*iter) |
| 689 | continue; /* skip dummy */ |
| 690 | mark_entry = get_marker((*iter)->channel, (*iter)->name); |
| 691 | if (mark_entry) { |
| 692 | set_marker(mark_entry, *iter, !!mark_entry->refcount); |
| 693 | /* |
| 694 | * ignore error, continue |
| 695 | */ |
| 696 | } else { |
| 697 | disable_marker(*iter); |
| 698 | } |
| 699 | } |
| 700 | pthread_mutex_unlock(&markers_mutex); |
| 701 | } |
| 702 | |
| 703 | static void lib_update_markers(void) |
| 704 | { |
| 705 | struct lib *lib; |
| 706 | |
| 707 | /* FIXME: we should probably take a mutex here on libs */ |
| 708 | //ust// pthread_mutex_lock(&module_mutex); |
| 709 | cds_list_for_each_entry(lib, &libs, list) |
| 710 | marker_update_probe_range(lib->markers_start, |
| 711 | lib->markers_start + lib->markers_count); |
| 712 | //ust// pthread_mutex_unlock(&module_mutex); |
| 713 | } |
| 714 | |
| 715 | /* |
| 716 | * Update probes, removing the faulty probes. |
| 717 | * |
| 718 | * Internal callback only changed before the first probe is connected to it. |
| 719 | * Single probe private data can only be changed on 0 -> 1 and 2 -> 1 |
| 720 | * transitions. All other transitions will leave the old private data valid. |
| 721 | * This makes the non-atomicity of the callback/private data updates valid. |
| 722 | * |
| 723 | * "special case" updates : |
| 724 | * 0 -> 1 callback |
| 725 | * 1 -> 0 callback |
| 726 | * 1 -> 2 callbacks |
| 727 | * 2 -> 1 callbacks |
| 728 | * Other updates all behave the same, just like the 2 -> 3 or 3 -> 2 updates. |
| 729 | * Site effect : marker_set_format may delete the marker entry (creating a |
| 730 | * replacement). |
| 731 | */ |
| 732 | static void marker_update_probes(void) |
| 733 | { |
| 734 | lib_update_markers(); |
| 735 | tracepoint_probe_update_all(); |
| 736 | /* Update immediate values */ |
| 737 | core_imv_update(); |
| 738 | //ust// module_imv_update(); /* FIXME: need to port for libs? */ |
| 739 | marker_update_processes(); |
| 740 | } |
| 741 | |
| 742 | /** |
| 743 | * marker_probe_register - Connect a probe to a marker |
| 744 | * @channel: marker channel |
| 745 | * @name: marker name |
| 746 | * @format: format string |
| 747 | * @probe: probe handler |
| 748 | * @probe_private: probe private data |
| 749 | * |
| 750 | * private data must be a valid allocated memory address, or NULL. |
| 751 | * Returns 0 if ok, error value on error. |
| 752 | * The probe address must at least be aligned on the architecture pointer size. |
| 753 | */ |
| 754 | int marker_probe_register(const char *channel, const char *name, |
| 755 | const char *format, marker_probe_func *probe, |
| 756 | void *probe_private) |
| 757 | { |
| 758 | struct marker_entry *entry; |
| 759 | int ret = 0, ret_err; |
| 760 | struct marker_probe_closure *old; |
| 761 | int first_probe = 0; |
| 762 | |
| 763 | pthread_mutex_lock(&markers_mutex); |
| 764 | entry = get_marker(channel, name); |
| 765 | if (!entry) { |
| 766 | first_probe = 1; |
| 767 | entry = add_marker(channel, name, format); |
| 768 | if (IS_ERR(entry)) |
| 769 | ret = PTR_ERR(entry); |
| 770 | if (ret) |
| 771 | goto end; |
| 772 | ret = ltt_channels_register(channel); |
| 773 | if (ret) |
| 774 | goto error_remove_marker; |
| 775 | ret = ltt_channels_get_index_from_name(channel); |
| 776 | if (ret < 0) |
| 777 | goto error_unregister_channel; |
| 778 | entry->channel_id = ret; |
| 779 | ret = ltt_channels_get_event_id(channel, name); |
| 780 | if (ret < 0) |
| 781 | goto error_unregister_channel; |
| 782 | entry->event_id = ret; |
| 783 | ret = 0; |
| 784 | trace_mark(metadata, core_marker_id, |
| 785 | "channel %s name %s event_id %hu " |
| 786 | "int #1u%zu long #1u%zu pointer #1u%zu " |
| 787 | "size_t #1u%zu alignment #1u%u", |
| 788 | channel, name, entry->event_id, |
| 789 | sizeof(int), sizeof(long), sizeof(void *), |
| 790 | sizeof(size_t), ltt_get_alignment()); |
| 791 | } else if (format) { |
| 792 | if (!entry->format) |
| 793 | ret = marker_set_format(entry, format); |
| 794 | else if (strcmp(entry->format, format)) |
| 795 | ret = -EPERM; |
| 796 | if (ret) |
| 797 | goto end; |
| 798 | } |
| 799 | |
| 800 | /* |
| 801 | * If we detect that a call_rcu is pending for this marker, |
| 802 | * make sure it's executed now. |
| 803 | */ |
| 804 | //ust// if (entry->rcu_pending) |
| 805 | //ust// rcu_cmm_barrier_sched(); |
| 806 | old = marker_entry_add_probe(entry, probe, probe_private); |
| 807 | if (IS_ERR(old)) { |
| 808 | ret = PTR_ERR(old); |
| 809 | if (first_probe) |
| 810 | goto error_unregister_channel; |
| 811 | else |
| 812 | goto end; |
| 813 | } |
| 814 | pthread_mutex_unlock(&markers_mutex); |
| 815 | |
| 816 | /* Activate marker if necessary */ |
| 817 | marker_update_probes(); |
| 818 | |
| 819 | pthread_mutex_lock(&markers_mutex); |
| 820 | entry = get_marker(channel, name); |
| 821 | if (!entry) |
| 822 | goto end; |
| 823 | //ust// if (entry->rcu_pending) |
| 824 | //ust// rcu_cmm_barrier_sched(); |
| 825 | entry->oldptr = old; |
| 826 | entry->rcu_pending = 1; |
| 827 | /* write rcu_pending before calling the RCU callback */ |
| 828 | cmm_smp_wmb(); |
| 829 | //ust// call_rcu_sched(&entry->rcu, free_old_closure); |
| 830 | synchronize_rcu(); free_old_closure(&entry->rcu); |
| 831 | goto end; |
| 832 | |
| 833 | error_unregister_channel: |
| 834 | ret_err = ltt_channels_unregister(channel); |
| 835 | WARN_ON(ret_err); |
| 836 | error_remove_marker: |
| 837 | ret_err = remove_marker(channel, name); |
| 838 | WARN_ON(ret_err); |
| 839 | end: |
| 840 | pthread_mutex_unlock(&markers_mutex); |
| 841 | return ret; |
| 842 | } |
| 843 | //ust// EXPORT_SYMBOL_GPL(marker_probe_register); |
| 844 | |
| 845 | /** |
| 846 | * marker_probe_unregister - Disconnect a probe from a marker |
| 847 | * @channel: marker channel |
| 848 | * @name: marker name |
| 849 | * @probe: probe function pointer |
| 850 | * @probe_private: probe private data |
| 851 | * |
| 852 | * Returns the private data given to marker_probe_register, or an ERR_PTR(). |
| 853 | * We do not need to call a synchronize_sched to make sure the probes have |
| 854 | * finished running before doing a module unload, because the module unload |
| 855 | * itself uses stop_machine(), which insures that every preempt disabled section |
| 856 | * have finished. |
| 857 | */ |
| 858 | int marker_probe_unregister(const char *channel, const char *name, |
| 859 | marker_probe_func *probe, void *probe_private) |
| 860 | { |
| 861 | struct marker_entry *entry; |
| 862 | struct marker_probe_closure *old; |
| 863 | int ret = -ENOENT; |
| 864 | |
| 865 | pthread_mutex_lock(&markers_mutex); |
| 866 | entry = get_marker(channel, name); |
| 867 | if (!entry) |
| 868 | goto end; |
| 869 | //ust// if (entry->rcu_pending) |
| 870 | //ust// rcu_cmm_barrier_sched(); |
| 871 | old = marker_entry_remove_probe(entry, probe, probe_private); |
| 872 | pthread_mutex_unlock(&markers_mutex); |
| 873 | |
| 874 | marker_update_probes(); |
| 875 | |
| 876 | pthread_mutex_lock(&markers_mutex); |
| 877 | entry = get_marker(channel, name); |
| 878 | if (!entry) |
| 879 | goto end; |
| 880 | //ust// if (entry->rcu_pending) |
| 881 | //ust// rcu_cmm_barrier_sched(); |
| 882 | entry->oldptr = old; |
| 883 | entry->rcu_pending = 1; |
| 884 | /* write rcu_pending before calling the RCU callback */ |
| 885 | cmm_smp_wmb(); |
| 886 | //ust// call_rcu_sched(&entry->rcu, free_old_closure); |
| 887 | synchronize_rcu(); free_old_closure(&entry->rcu); |
| 888 | remove_marker(channel, name); /* Ignore busy error message */ |
| 889 | ret = 0; |
| 890 | end: |
| 891 | pthread_mutex_unlock(&markers_mutex); |
| 892 | return ret; |
| 893 | } |
| 894 | //ust// EXPORT_SYMBOL_GPL(marker_probe_unregister); |
| 895 | |
| 896 | static struct marker_entry * |
| 897 | get_marker_from_private_data(marker_probe_func *probe, void *probe_private) |
| 898 | { |
| 899 | struct marker_entry *entry; |
| 900 | unsigned int i; |
| 901 | struct cds_hlist_head *head; |
| 902 | struct cds_hlist_node *node; |
| 903 | |
| 904 | for (i = 0; i < MARKER_TABLE_SIZE; i++) { |
| 905 | head = &marker_table[i]; |
| 906 | cds_hlist_for_each_entry(entry, node, head, hlist) { |
| 907 | if (!entry->ptype) { |
| 908 | if (entry->single.func == probe |
| 909 | && entry->single.probe_private |
| 910 | == probe_private) |
| 911 | return entry; |
| 912 | } else { |
| 913 | struct marker_probe_closure *closure; |
| 914 | closure = entry->multi; |
| 915 | for (i = 0; closure[i].func; i++) { |
| 916 | if (closure[i].func == probe && |
| 917 | closure[i].probe_private |
| 918 | == probe_private) |
| 919 | return entry; |
| 920 | } |
| 921 | } |
| 922 | } |
| 923 | } |
| 924 | return NULL; |
| 925 | } |
| 926 | |
| 927 | /** |
| 928 | * marker_probe_unregister_private_data - Disconnect a probe from a marker |
| 929 | * @probe: probe function |
| 930 | * @probe_private: probe private data |
| 931 | * |
| 932 | * Unregister a probe by providing the registered private data. |
| 933 | * Only removes the first marker found in hash table. |
| 934 | * Return 0 on success or error value. |
| 935 | * We do not need to call a synchronize_sched to make sure the probes have |
| 936 | * finished running before doing a module unload, because the module unload |
| 937 | * itself uses stop_machine(), which insures that every preempt disabled section |
| 938 | * have finished. |
| 939 | */ |
| 940 | int marker_probe_unregister_private_data(marker_probe_func *probe, |
| 941 | void *probe_private) |
| 942 | { |
| 943 | struct marker_entry *entry; |
| 944 | int ret = 0; |
| 945 | struct marker_probe_closure *old; |
| 946 | char *channel = NULL, *name = NULL; |
| 947 | |
| 948 | pthread_mutex_lock(&markers_mutex); |
| 949 | entry = get_marker_from_private_data(probe, probe_private); |
| 950 | if (!entry) { |
| 951 | ret = -ENOENT; |
| 952 | goto end; |
| 953 | } |
| 954 | //ust// if (entry->rcu_pending) |
| 955 | //ust// rcu_cmm_barrier_sched(); |
| 956 | old = marker_entry_remove_probe(entry, NULL, probe_private); |
| 957 | channel = strdup(entry->channel); |
| 958 | name = strdup(entry->name); |
| 959 | pthread_mutex_unlock(&markers_mutex); |
| 960 | |
| 961 | marker_update_probes(); |
| 962 | |
| 963 | pthread_mutex_lock(&markers_mutex); |
| 964 | entry = get_marker(channel, name); |
| 965 | if (!entry) |
| 966 | goto end; |
| 967 | //ust// if (entry->rcu_pending) |
| 968 | //ust// rcu_cmm_barrier_sched(); |
| 969 | entry->oldptr = old; |
| 970 | entry->rcu_pending = 1; |
| 971 | /* write rcu_pending before calling the RCU callback */ |
| 972 | cmm_smp_wmb(); |
| 973 | //ust// call_rcu_sched(&entry->rcu, free_old_closure); |
| 974 | synchronize_rcu(); free_old_closure(&entry->rcu); |
| 975 | /* Ignore busy error message */ |
| 976 | remove_marker(channel, name); |
| 977 | end: |
| 978 | pthread_mutex_unlock(&markers_mutex); |
| 979 | free(channel); |
| 980 | free(name); |
| 981 | return ret; |
| 982 | } |
| 983 | //ust// EXPORT_SYMBOL_GPL(marker_probe_unregister_private_data); |
| 984 | |
| 985 | /** |
| 986 | * marker_get_private_data - Get a marker's probe private data |
| 987 | * @channel: marker channel |
| 988 | * @name: marker name |
| 989 | * @probe: probe to match |
| 990 | * @num: get the nth matching probe's private data |
| 991 | * |
| 992 | * Returns the nth private data pointer (starting from 0) matching, or an |
| 993 | * ERR_PTR. |
| 994 | * Returns the private data pointer, or an ERR_PTR. |
| 995 | * The private data pointer should _only_ be dereferenced if the caller is the |
| 996 | * owner of the data, or its content could vanish. This is mostly used to |
| 997 | * confirm that a caller is the owner of a registered probe. |
| 998 | */ |
| 999 | void *marker_get_private_data(const char *channel, const char *name, |
| 1000 | marker_probe_func *probe, int num) |
| 1001 | { |
| 1002 | struct cds_hlist_head *head; |
| 1003 | struct cds_hlist_node *node; |
| 1004 | struct marker_entry *e; |
| 1005 | size_t channel_len = strlen(channel) + 1; |
| 1006 | size_t name_len = strlen(name) + 1; |
| 1007 | int i; |
| 1008 | u32 hash; |
| 1009 | |
| 1010 | hash = jhash(channel, channel_len-1, 0) ^ jhash(name, name_len-1, 0); |
| 1011 | head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; |
| 1012 | cds_hlist_for_each_entry(e, node, head, hlist) { |
| 1013 | if (!strcmp(channel, e->channel) && !strcmp(name, e->name)) { |
| 1014 | if (!e->ptype) { |
| 1015 | if (num == 0 && e->single.func == probe) |
| 1016 | return e->single.probe_private; |
| 1017 | } else { |
| 1018 | struct marker_probe_closure *closure; |
| 1019 | int match = 0; |
| 1020 | closure = e->multi; |
| 1021 | for (i = 0; closure[i].func; i++) { |
| 1022 | if (closure[i].func != probe) |
| 1023 | continue; |
| 1024 | if (match++ == num) |
| 1025 | return closure[i].probe_private; |
| 1026 | } |
| 1027 | } |
| 1028 | break; |
| 1029 | } |
| 1030 | } |
| 1031 | return ERR_PTR(-ENOENT); |
| 1032 | } |
| 1033 | //ust// EXPORT_SYMBOL_GPL(marker_get_private_data); |
| 1034 | |
| 1035 | /** |
| 1036 | * markers_compact_event_ids - Compact markers event IDs and reassign channels |
| 1037 | * |
| 1038 | * Called when no channel users are active by the channel infrastructure. |
| 1039 | * Called with lock_markers() and channel mutex held. |
| 1040 | */ |
| 1041 | //ust// void markers_compact_event_ids(void) |
| 1042 | //ust// { |
| 1043 | //ust// struct marker_entry *entry; |
| 1044 | //ust// unsigned int i; |
| 1045 | //ust// struct hlist_head *head; |
| 1046 | //ust// struct hlist_node *node; |
| 1047 | //ust// int ret; |
| 1048 | //ust// |
| 1049 | //ust// for (i = 0; i < MARKER_TABLE_SIZE; i++) { |
| 1050 | //ust// head = &marker_table[i]; |
| 1051 | //ust// hlist_for_each_entry(entry, node, head, hlist) { |
| 1052 | //ust// ret = ltt_channels_get_index_from_name(entry->channel); |
| 1053 | //ust// WARN_ON(ret < 0); |
| 1054 | //ust// entry->channel_id = ret; |
| 1055 | //ust// ret = _ltt_channels_get_event_id(entry->channel, |
| 1056 | //ust// entry->name); |
| 1057 | //ust// WARN_ON(ret < 0); |
| 1058 | //ust// entry->event_id = ret; |
| 1059 | //ust// } |
| 1060 | //ust// } |
| 1061 | //ust// } |
| 1062 | |
| 1063 | //ust//#ifdef CONFIG_MODULES |
| 1064 | |
| 1065 | /* |
| 1066 | * Returns 0 if current not found. |
| 1067 | * Returns 1 if current found. |
| 1068 | */ |
| 1069 | int lib_get_iter_markers(struct marker_iter *iter) |
| 1070 | { |
| 1071 | struct lib *iter_lib; |
| 1072 | int found = 0; |
| 1073 | |
| 1074 | //ust// pthread_mutex_lock(&module_mutex); |
| 1075 | cds_list_for_each_entry(iter_lib, &libs, list) { |
| 1076 | if (iter_lib < iter->lib) |
| 1077 | continue; |
| 1078 | else if (iter_lib > iter->lib) |
| 1079 | iter->marker = NULL; |
| 1080 | found = marker_get_iter_range(&iter->marker, |
| 1081 | iter_lib->markers_start, |
| 1082 | iter_lib->markers_start + iter_lib->markers_count); |
| 1083 | if (found) { |
| 1084 | iter->lib = iter_lib; |
| 1085 | break; |
| 1086 | } |
| 1087 | } |
| 1088 | //ust// pthread_mutex_unlock(&module_mutex); |
| 1089 | return found; |
| 1090 | } |
| 1091 | |
| 1092 | /** |
| 1093 | * marker_get_iter_range - Get a next marker iterator given a range. |
| 1094 | * @marker: current markers (in), next marker (out) |
| 1095 | * @begin: beginning of the range |
| 1096 | * @end: end of the range |
| 1097 | * |
| 1098 | * Returns whether a next marker has been found (1) or not (0). |
| 1099 | * Will return the first marker in the range if the input marker is NULL. |
| 1100 | */ |
| 1101 | int marker_get_iter_range(struct marker * const **marker, |
| 1102 | struct marker * const *begin, |
| 1103 | struct marker * const *end) |
| 1104 | { |
| 1105 | if (!*marker && begin != end) |
| 1106 | *marker = begin; |
| 1107 | while (*marker >= begin && *marker < end) { |
| 1108 | if (!**marker) |
| 1109 | (*marker)++; /* skip dummy */ |
| 1110 | else |
| 1111 | return 1; |
| 1112 | } |
| 1113 | return 0; |
| 1114 | } |
| 1115 | //ust// EXPORT_SYMBOL_GPL(marker_get_iter_range); |
| 1116 | |
| 1117 | static void marker_get_iter(struct marker_iter *iter) |
| 1118 | { |
| 1119 | int found = 0; |
| 1120 | |
| 1121 | found = lib_get_iter_markers(iter); |
| 1122 | if (!found) |
| 1123 | marker_iter_reset(iter); |
| 1124 | } |
| 1125 | |
| 1126 | void marker_iter_start(struct marker_iter *iter) |
| 1127 | { |
| 1128 | marker_get_iter(iter); |
| 1129 | } |
| 1130 | //ust// EXPORT_SYMBOL_GPL(marker_iter_start); |
| 1131 | |
| 1132 | void marker_iter_next(struct marker_iter *iter) |
| 1133 | { |
| 1134 | iter->marker++; |
| 1135 | /* |
| 1136 | * iter->marker may be invalid because we blindly incremented it. |
| 1137 | * Make sure it is valid by marshalling on the markers, getting the |
| 1138 | * markers from following modules if necessary. |
| 1139 | */ |
| 1140 | marker_get_iter(iter); |
| 1141 | } |
| 1142 | //ust// EXPORT_SYMBOL_GPL(marker_iter_next); |
| 1143 | |
| 1144 | void marker_iter_stop(struct marker_iter *iter) |
| 1145 | { |
| 1146 | } |
| 1147 | //ust// EXPORT_SYMBOL_GPL(marker_iter_stop); |
| 1148 | |
| 1149 | void marker_iter_reset(struct marker_iter *iter) |
| 1150 | { |
| 1151 | iter->lib = NULL; |
| 1152 | iter->marker = NULL; |
| 1153 | } |
| 1154 | //ust// EXPORT_SYMBOL_GPL(marker_iter_reset); |
| 1155 | |
| 1156 | #ifdef CONFIG_MARKERS_USERSPACE |
| 1157 | /* |
| 1158 | * must be called with current->user_markers_mutex held |
| 1159 | */ |
| 1160 | static void free_user_marker(char __user *state, struct cds_hlist_head *head) |
| 1161 | { |
| 1162 | struct user_marker *umark; |
| 1163 | struct cds_hlist_node *pos, *n; |
| 1164 | |
| 1165 | cds_hlist_for_each_entry_safe(umark, pos, n, head, hlist) { |
| 1166 | if (umark->state == state) { |
| 1167 | cds_hlist_del(&umark->hlist); |
| 1168 | free(umark); |
| 1169 | } |
| 1170 | } |
| 1171 | } |
| 1172 | |
| 1173 | /* |
| 1174 | * Update current process. |
| 1175 | * Note that we have to wait a whole scheduler period before we are sure that |
| 1176 | * every running userspace threads have their markers updated. |
| 1177 | * (synchronize_sched() can be used to insure this). |
| 1178 | */ |
| 1179 | //ust// void marker_update_process(void) |
| 1180 | //ust// { |
| 1181 | //ust// struct user_marker *umark; |
| 1182 | //ust// struct hlist_node *pos; |
| 1183 | //ust// struct marker_entry *entry; |
| 1184 | //ust// |
| 1185 | //ust// pthread_mutex_lock(&markers_mutex); |
| 1186 | //ust// pthread_mutex_lock(¤t->group_leader->user_markers_mutex); |
| 1187 | //ust// if (strcmp(current->comm, "testprog") == 0) |
| 1188 | //ust// DBG("do update pending for testprog"); |
| 1189 | //ust// hlist_for_each_entry(umark, pos, |
| 1190 | //ust// ¤t->group_leader->user_markers, hlist) { |
| 1191 | //ust// DBG("Updating marker %s in %s", umark->name, current->comm); |
| 1192 | //ust// entry = get_marker("userspace", umark->name); |
| 1193 | //ust// if (entry) { |
| 1194 | //ust// if (entry->format && |
| 1195 | //ust// strcmp(entry->format, umark->format) != 0) { |
| 1196 | //ust// WARN("error, wrong format in process %s", |
| 1197 | //ust// current->comm); |
| 1198 | //ust// break; |
| 1199 | //ust// } |
| 1200 | //ust// if (put_user(!!entry->refcount, umark->state)) { |
| 1201 | //ust// WARN("Marker in %s caused a fault", |
| 1202 | //ust// current->comm); |
| 1203 | //ust// break; |
| 1204 | //ust// } |
| 1205 | //ust// } else { |
| 1206 | //ust// if (put_user(0, umark->state)) { |
| 1207 | //ust// WARN("Marker in %s caused a fault", current->comm); |
| 1208 | //ust// break; |
| 1209 | //ust// } |
| 1210 | //ust// } |
| 1211 | //ust// } |
| 1212 | //ust// clear_thread_flag(TIF_MARKER_PENDING); |
| 1213 | //ust// pthread_mutex_unlock(¤t->group_leader->user_markers_mutex); |
| 1214 | //ust// pthread_mutex_unlock(&markers_mutex); |
| 1215 | //ust// } |
| 1216 | |
| 1217 | /* |
| 1218 | * Called at process exit and upon do_execve(). |
| 1219 | * We assume that when the leader exits, no more references can be done to the |
| 1220 | * leader structure by the other threads. |
| 1221 | */ |
| 1222 | void exit_user_markers(struct task_struct *p) |
| 1223 | { |
| 1224 | struct user_marker *umark; |
| 1225 | struct cds_hlist_node *pos, *n; |
| 1226 | |
| 1227 | if (thread_group_leader(p)) { |
| 1228 | pthread_mutex_lock(&markers_mutex); |
| 1229 | pthread_mutex_lock(&p->user_markers_mutex); |
| 1230 | cds_hlist_for_each_entry_safe(umark, pos, n, &p->user_markers, |
| 1231 | hlist) |
| 1232 | free(umark); |
| 1233 | INIT_HLIST_HEAD(&p->user_markers); |
| 1234 | p->user_markers_sequence++; |
| 1235 | pthread_mutex_unlock(&p->user_markers_mutex); |
| 1236 | pthread_mutex_unlock(&markers_mutex); |
| 1237 | } |
| 1238 | } |
| 1239 | |
| 1240 | int is_marker_enabled(const char *channel, const char *name) |
| 1241 | { |
| 1242 | struct marker_entry *entry; |
| 1243 | |
| 1244 | pthread_mutex_lock(&markers_mutex); |
| 1245 | entry = get_marker(channel, name); |
| 1246 | pthread_mutex_unlock(&markers_mutex); |
| 1247 | |
| 1248 | return entry && !!entry->refcount; |
| 1249 | } |
| 1250 | //ust// #endif |
| 1251 | |
| 1252 | int marker_module_notify(struct notifier_block *self, |
| 1253 | unsigned long val, void *data) |
| 1254 | { |
| 1255 | struct module *mod = data; |
| 1256 | |
| 1257 | switch (val) { |
| 1258 | case MODULE_STATE_COMING: |
| 1259 | marker_update_probe_range(mod->markers, |
| 1260 | mod->markers + mod->num_markers); |
| 1261 | break; |
| 1262 | case MODULE_STATE_GOING: |
| 1263 | marker_update_probe_range(mod->markers, |
| 1264 | mod->markers + mod->num_markers); |
| 1265 | break; |
| 1266 | } |
| 1267 | return 0; |
| 1268 | } |
| 1269 | |
| 1270 | struct notifier_block marker_module_nb = { |
| 1271 | .notifier_call = marker_module_notify, |
| 1272 | .priority = 0, |
| 1273 | }; |
| 1274 | |
| 1275 | //ust// static int init_markers(void) |
| 1276 | //ust// { |
| 1277 | //ust// return register_module_notifier(&marker_module_nb); |
| 1278 | //ust// } |
| 1279 | //ust// __initcall(init_markers); |
| 1280 | /* TODO: call marker_module_nb() when a library is linked at runtime (dlopen)? */ |
| 1281 | |
| 1282 | #endif /* CONFIG_MODULES */ |
| 1283 | |
| 1284 | void ltt_dump_marker_state(struct ust_trace *trace) |
| 1285 | { |
| 1286 | struct marker_entry *entry; |
| 1287 | struct ltt_probe_private_data call_data; |
| 1288 | struct cds_hlist_head *head; |
| 1289 | struct cds_hlist_node *node; |
| 1290 | unsigned int i; |
| 1291 | |
| 1292 | pthread_mutex_lock(&markers_mutex); |
| 1293 | call_data.trace = trace; |
| 1294 | call_data.serializer = NULL; |
| 1295 | |
| 1296 | for (i = 0; i < MARKER_TABLE_SIZE; i++) { |
| 1297 | head = &marker_table[i]; |
| 1298 | cds_hlist_for_each_entry(entry, node, head, hlist) { |
| 1299 | __trace_mark(0, metadata, core_marker_id, |
| 1300 | &call_data, |
| 1301 | "channel %s name %s event_id %hu " |
| 1302 | "int #1u%zu long #1u%zu pointer #1u%zu " |
| 1303 | "size_t #1u%zu alignment #1u%u", |
| 1304 | entry->channel, |
| 1305 | entry->name, |
| 1306 | entry->event_id, |
| 1307 | sizeof(int), sizeof(long), |
| 1308 | sizeof(void *), sizeof(size_t), |
| 1309 | ltt_get_alignment()); |
| 1310 | if (entry->format) |
| 1311 | __trace_mark(0, metadata, |
| 1312 | core_marker_format, |
| 1313 | &call_data, |
| 1314 | "channel %s name %s format %s", |
| 1315 | entry->channel, |
| 1316 | entry->name, |
| 1317 | entry->format); |
| 1318 | } |
| 1319 | } |
| 1320 | pthread_mutex_unlock(&markers_mutex); |
| 1321 | } |
| 1322 | //ust// EXPORT_SYMBOL_GPL(ltt_dump_marker_state); |
| 1323 | |
| 1324 | static void (*new_marker_cb)(struct marker *) = NULL; |
| 1325 | |
| 1326 | void marker_set_new_marker_cb(void (*cb)(struct marker *)) |
| 1327 | { |
| 1328 | new_marker_cb = cb; |
| 1329 | } |
| 1330 | |
| 1331 | static void new_markers(struct marker * const *start, struct marker * const *end) |
| 1332 | { |
| 1333 | if (new_marker_cb) { |
| 1334 | struct marker * const *m; |
| 1335 | |
| 1336 | for(m = start; m < end; m++) { |
| 1337 | if (*m) |
| 1338 | new_marker_cb(*m); |
| 1339 | } |
| 1340 | } |
| 1341 | } |
| 1342 | |
| 1343 | int marker_register_lib(struct marker * const *markers_start, int markers_count) |
| 1344 | { |
| 1345 | struct lib *pl, *iter; |
| 1346 | |
| 1347 | pl = (struct lib *) zmalloc(sizeof(struct lib)); |
| 1348 | |
| 1349 | pl->markers_start = markers_start; |
| 1350 | pl->markers_count = markers_count; |
| 1351 | |
| 1352 | /* FIXME: maybe protect this with its own mutex? */ |
| 1353 | lock_markers(); |
| 1354 | |
| 1355 | /* |
| 1356 | * We sort the libs by struct lib pointer address. |
| 1357 | */ |
| 1358 | cds_list_for_each_entry_reverse(iter, &libs, list) { |
| 1359 | BUG_ON(iter == pl); /* Should never be in the list twice */ |
| 1360 | if (iter < pl) { |
| 1361 | /* We belong to the location right after iter. */ |
| 1362 | cds_list_add(&pl->list, &iter->list); |
| 1363 | goto lib_added; |
| 1364 | } |
| 1365 | } |
| 1366 | /* We should be added at the head of the list */ |
| 1367 | cds_list_add(&pl->list, &libs); |
| 1368 | lib_added: |
| 1369 | unlock_markers(); |
| 1370 | |
| 1371 | new_markers(markers_start, markers_start + markers_count); |
| 1372 | |
| 1373 | /* FIXME: update just the loaded lib */ |
| 1374 | lib_update_markers(); |
| 1375 | |
| 1376 | DBG("just registered a markers section from %p and having %d markers (minus dummy markers)", markers_start, markers_count); |
| 1377 | |
| 1378 | return 0; |
| 1379 | } |
| 1380 | |
| 1381 | int marker_unregister_lib(struct marker * const *markers_start) |
| 1382 | { |
| 1383 | struct lib *lib; |
| 1384 | |
| 1385 | /*FIXME: implement; but before implementing, marker_register_lib must |
| 1386 | have appropriate locking. */ |
| 1387 | |
| 1388 | lock_markers(); |
| 1389 | |
| 1390 | /* FIXME: we should probably take a mutex here on libs */ |
| 1391 | //ust// pthread_mutex_lock(&module_mutex); |
| 1392 | cds_list_for_each_entry(lib, &libs, list) { |
| 1393 | if(lib->markers_start == markers_start) { |
| 1394 | struct lib *lib2free = lib; |
| 1395 | cds_list_del(&lib->list); |
| 1396 | free(lib2free); |
| 1397 | break; |
| 1398 | } |
| 1399 | } |
| 1400 | |
| 1401 | unlock_markers(); |
| 1402 | |
| 1403 | return 0; |
| 1404 | } |
| 1405 | |
| 1406 | static int initialized = 0; |
| 1407 | |
| 1408 | void __attribute__((constructor)) init_markers(void) |
| 1409 | { |
| 1410 | if (!initialized) { |
| 1411 | marker_register_lib(__start___markers_ptrs, |
| 1412 | __stop___markers_ptrs |
| 1413 | - __start___markers_ptrs); |
| 1414 | initialized = 1; |
| 1415 | } |
| 1416 | } |
| 1417 | |
| 1418 | void __attribute__((destructor)) destroy_markers(void) |
| 1419 | { |
| 1420 | marker_unregister_lib(__start___markers_ptrs); |
| 1421 | } |