| 1 | /* |
| 2 | * Copyright (C) 2007 Mathieu Desnoyers |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License as published by |
| 6 | * the Free Software Foundation; either version 2 of the License, or |
| 7 | * (at your option) any later version. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public License |
| 15 | * along with this program; if not, write to the Free Software |
| 16 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 17 | */ |
| 18 | //ust// #include <linux/module.h> |
| 19 | //ust// #include <linux/mutex.h> |
| 20 | //ust// #include <linux/types.h> |
| 21 | //#include "jhash.h" |
| 22 | //#include "list.h" |
| 23 | //#include "rcupdate.h" |
| 24 | //ust// #include <linux/marker.h> |
| 25 | #include <errno.h> |
| 26 | //ust// #include <linux/slab.h> |
| 27 | //ust// #include <linux/immediate.h> |
| 28 | //ust// #include <linux/sched.h> |
| 29 | //ust// #include <linux/uaccess.h> |
| 30 | //ust// #include <linux/user_marker.h> |
| 31 | //ust// #include <linux/ltt-tracer.h> |
| 32 | |
| 33 | #define _LGPL_SOURCE |
| 34 | #include <urcu.h> |
| 35 | |
| 36 | #include "kernelcompat.h" |
| 37 | |
| 38 | #include "marker.h" |
| 39 | #include "usterr.h" |
| 40 | #include "channels.h" |
| 41 | #include "tracercore.h" |
| 42 | #include "tracer.h" |
| 43 | |
| 44 | extern struct marker __start___markers[] __attribute__((visibility("hidden"))); |
| 45 | extern struct marker __stop___markers[] __attribute__((visibility("hidden"))); |
| 46 | |
| 47 | /* Set to 1 to enable marker debug output */ |
| 48 | static const int marker_debug; |
| 49 | |
| 50 | /* |
| 51 | * markers_mutex nests inside module_mutex. Markers mutex protects the builtin |
| 52 | * and module markers and the hash table. |
| 53 | */ |
| 54 | static DEFINE_MUTEX(markers_mutex); |
| 55 | |
| 56 | void lock_markers(void) |
| 57 | { |
| 58 | mutex_lock(&markers_mutex); |
| 59 | } |
| 60 | |
| 61 | void unlock_markers(void) |
| 62 | { |
| 63 | mutex_unlock(&markers_mutex); |
| 64 | } |
| 65 | |
| 66 | /* |
| 67 | * Marker hash table, containing the active markers. |
| 68 | * Protected by module_mutex. |
| 69 | */ |
| 70 | #define MARKER_HASH_BITS 6 |
| 71 | #define MARKER_TABLE_SIZE (1 << MARKER_HASH_BITS) |
| 72 | static struct hlist_head marker_table[MARKER_TABLE_SIZE]; |
| 73 | |
| 74 | /* |
| 75 | * Note about RCU : |
| 76 | * It is used to make sure every handler has finished using its private data |
| 77 | * between two consecutive operation (add or remove) on a given marker. It is |
| 78 | * also used to delay the free of multiple probes array until a quiescent state |
| 79 | * is reached. |
| 80 | * marker entries modifications are protected by the markers_mutex. |
| 81 | */ |
| 82 | struct marker_entry { |
| 83 | struct hlist_node hlist; |
| 84 | char *format; |
| 85 | char *name; |
| 86 | /* Probe wrapper */ |
| 87 | void (*call)(const struct marker *mdata, void *call_private, ...); |
| 88 | struct marker_probe_closure single; |
| 89 | struct marker_probe_closure *multi; |
| 90 | int refcount; /* Number of times armed. 0 if disarmed. */ |
| 91 | struct rcu_head rcu; |
| 92 | void *oldptr; |
| 93 | int rcu_pending; |
| 94 | u16 channel_id; |
| 95 | u16 event_id; |
| 96 | unsigned char ptype:1; |
| 97 | unsigned char format_allocated:1; |
| 98 | char channel[0]; /* Contains channel'\0'name'\0'format'\0' */ |
| 99 | }; |
| 100 | |
| 101 | #ifdef CONFIG_MARKERS_USERSPACE |
| 102 | static void marker_update_processes(void); |
| 103 | #else |
| 104 | static void marker_update_processes(void) |
| 105 | { |
| 106 | } |
| 107 | #endif |
| 108 | |
| 109 | /** |
| 110 | * __mark_empty_function - Empty probe callback |
| 111 | * @mdata: marker data |
| 112 | * @probe_private: probe private data |
| 113 | * @call_private: call site private data |
| 114 | * @fmt: format string |
| 115 | * @...: variable argument list |
| 116 | * |
| 117 | * Empty callback provided as a probe to the markers. By providing this to a |
| 118 | * disabled marker, we make sure the execution flow is always valid even |
| 119 | * though the function pointer change and the marker enabling are two distinct |
| 120 | * operations that modifies the execution flow of preemptible code. |
| 121 | */ |
| 122 | notrace void __mark_empty_function(const struct marker *mdata, |
| 123 | void *probe_private, void *call_private, const char *fmt, va_list *args) |
| 124 | { |
| 125 | } |
| 126 | //ust// EXPORT_SYMBOL_GPL(__mark_empty_function); |
| 127 | |
| 128 | /* |
| 129 | * marker_probe_cb Callback that prepares the variable argument list for probes. |
| 130 | * @mdata: pointer of type struct marker |
| 131 | * @call_private: caller site private data |
| 132 | * @...: Variable argument list. |
| 133 | * |
| 134 | * Since we do not use "typical" pointer based RCU in the 1 argument case, we |
| 135 | * need to put a full smp_rmb() in this branch. This is why we do not use |
| 136 | * rcu_dereference() for the pointer read. |
| 137 | */ |
| 138 | notrace void marker_probe_cb(const struct marker *mdata, |
| 139 | void *call_private, ...) |
| 140 | { |
| 141 | va_list args; |
| 142 | char ptype; |
| 143 | |
| 144 | /* |
| 145 | * rcu_read_lock_sched does two things : disabling preemption to make |
| 146 | * sure the teardown of the callbacks can be done correctly when they |
| 147 | * are in modules and they insure RCU read coherency. |
| 148 | */ |
| 149 | //ust// rcu_read_lock_sched_notrace(); |
| 150 | ptype = mdata->ptype; |
| 151 | if (likely(!ptype)) { |
| 152 | marker_probe_func *func; |
| 153 | /* Must read the ptype before ptr. They are not data dependant, |
| 154 | * so we put an explicit smp_rmb() here. */ |
| 155 | smp_rmb(); |
| 156 | func = mdata->single.func; |
| 157 | /* Must read the ptr before private data. They are not data |
| 158 | * dependant, so we put an explicit smp_rmb() here. */ |
| 159 | smp_rmb(); |
| 160 | va_start(args, call_private); |
| 161 | func(mdata, mdata->single.probe_private, call_private, |
| 162 | mdata->format, &args); |
| 163 | va_end(args); |
| 164 | } else { |
| 165 | struct marker_probe_closure *multi; |
| 166 | int i; |
| 167 | /* |
| 168 | * Read mdata->ptype before mdata->multi. |
| 169 | */ |
| 170 | smp_rmb(); |
| 171 | multi = mdata->multi; |
| 172 | /* |
| 173 | * multi points to an array, therefore accessing the array |
| 174 | * depends on reading multi. However, even in this case, |
| 175 | * we must insure that the pointer is read _before_ the array |
| 176 | * data. Same as rcu_dereference, but we need a full smp_rmb() |
| 177 | * in the fast path, so put the explicit barrier here. |
| 178 | */ |
| 179 | smp_read_barrier_depends(); |
| 180 | for (i = 0; multi[i].func; i++) { |
| 181 | va_start(args, call_private); |
| 182 | multi[i].func(mdata, multi[i].probe_private, |
| 183 | call_private, mdata->format, &args); |
| 184 | va_end(args); |
| 185 | } |
| 186 | } |
| 187 | //ust// rcu_read_unlock_sched_notrace(); |
| 188 | } |
| 189 | //ust// EXPORT_SYMBOL_GPL(marker_probe_cb); |
| 190 | |
| 191 | /* |
| 192 | * marker_probe_cb Callback that does not prepare the variable argument list. |
| 193 | * @mdata: pointer of type struct marker |
| 194 | * @call_private: caller site private data |
| 195 | * @...: Variable argument list. |
| 196 | * |
| 197 | * Should be connected to markers "MARK_NOARGS". |
| 198 | */ |
| 199 | static notrace void marker_probe_cb_noarg(const struct marker *mdata, |
| 200 | void *call_private, ...) |
| 201 | { |
| 202 | va_list args; /* not initialized */ |
| 203 | char ptype; |
| 204 | |
| 205 | //ust// rcu_read_lock_sched_notrace(); |
| 206 | ptype = mdata->ptype; |
| 207 | if (likely(!ptype)) { |
| 208 | marker_probe_func *func; |
| 209 | /* Must read the ptype before ptr. They are not data dependant, |
| 210 | * so we put an explicit smp_rmb() here. */ |
| 211 | smp_rmb(); |
| 212 | func = mdata->single.func; |
| 213 | /* Must read the ptr before private data. They are not data |
| 214 | * dependant, so we put an explicit smp_rmb() here. */ |
| 215 | smp_rmb(); |
| 216 | func(mdata, mdata->single.probe_private, call_private, |
| 217 | mdata->format, &args); |
| 218 | } else { |
| 219 | struct marker_probe_closure *multi; |
| 220 | int i; |
| 221 | /* |
| 222 | * Read mdata->ptype before mdata->multi. |
| 223 | */ |
| 224 | smp_rmb(); |
| 225 | multi = mdata->multi; |
| 226 | /* |
| 227 | * multi points to an array, therefore accessing the array |
| 228 | * depends on reading multi. However, even in this case, |
| 229 | * we must insure that the pointer is read _before_ the array |
| 230 | * data. Same as rcu_dereference, but we need a full smp_rmb() |
| 231 | * in the fast path, so put the explicit barrier here. |
| 232 | */ |
| 233 | smp_read_barrier_depends(); |
| 234 | for (i = 0; multi[i].func; i++) |
| 235 | multi[i].func(mdata, multi[i].probe_private, |
| 236 | call_private, mdata->format, &args); |
| 237 | } |
| 238 | //ust// rcu_read_unlock_sched_notrace(); |
| 239 | } |
| 240 | |
| 241 | static void free_old_closure(struct rcu_head *head) |
| 242 | { |
| 243 | struct marker_entry *entry = container_of(head, |
| 244 | struct marker_entry, rcu); |
| 245 | kfree(entry->oldptr); |
| 246 | /* Make sure we free the data before setting the pending flag to 0 */ |
| 247 | smp_wmb(); |
| 248 | entry->rcu_pending = 0; |
| 249 | } |
| 250 | |
| 251 | static void debug_print_probes(struct marker_entry *entry) |
| 252 | { |
| 253 | int i; |
| 254 | |
| 255 | if (!marker_debug) |
| 256 | return; |
| 257 | |
| 258 | if (!entry->ptype) { |
| 259 | printk(KERN_DEBUG "Single probe : %p %p\n", |
| 260 | entry->single.func, |
| 261 | entry->single.probe_private); |
| 262 | } else { |
| 263 | for (i = 0; entry->multi[i].func; i++) |
| 264 | printk(KERN_DEBUG "Multi probe %d : %p %p\n", i, |
| 265 | entry->multi[i].func, |
| 266 | entry->multi[i].probe_private); |
| 267 | } |
| 268 | } |
| 269 | |
| 270 | static struct marker_probe_closure * |
| 271 | marker_entry_add_probe(struct marker_entry *entry, |
| 272 | marker_probe_func *probe, void *probe_private) |
| 273 | { |
| 274 | int nr_probes = 0; |
| 275 | struct marker_probe_closure *old, *new; |
| 276 | |
| 277 | WARN_ON(!probe); |
| 278 | |
| 279 | debug_print_probes(entry); |
| 280 | old = entry->multi; |
| 281 | if (!entry->ptype) { |
| 282 | if (entry->single.func == probe && |
| 283 | entry->single.probe_private == probe_private) |
| 284 | return ERR_PTR(-EBUSY); |
| 285 | if (entry->single.func == __mark_empty_function) { |
| 286 | /* 0 -> 1 probes */ |
| 287 | entry->single.func = probe; |
| 288 | entry->single.probe_private = probe_private; |
| 289 | entry->refcount = 1; |
| 290 | entry->ptype = 0; |
| 291 | debug_print_probes(entry); |
| 292 | return NULL; |
| 293 | } else { |
| 294 | /* 1 -> 2 probes */ |
| 295 | nr_probes = 1; |
| 296 | old = NULL; |
| 297 | } |
| 298 | } else { |
| 299 | /* (N -> N+1), (N != 0, 1) probes */ |
| 300 | for (nr_probes = 0; old[nr_probes].func; nr_probes++) |
| 301 | if (old[nr_probes].func == probe |
| 302 | && old[nr_probes].probe_private |
| 303 | == probe_private) |
| 304 | return ERR_PTR(-EBUSY); |
| 305 | } |
| 306 | /* + 2 : one for new probe, one for NULL func */ |
| 307 | new = kzalloc((nr_probes + 2) * sizeof(struct marker_probe_closure), |
| 308 | GFP_KERNEL); |
| 309 | if (new == NULL) |
| 310 | return ERR_PTR(-ENOMEM); |
| 311 | if (!old) |
| 312 | new[0] = entry->single; |
| 313 | else |
| 314 | memcpy(new, old, |
| 315 | nr_probes * sizeof(struct marker_probe_closure)); |
| 316 | new[nr_probes].func = probe; |
| 317 | new[nr_probes].probe_private = probe_private; |
| 318 | entry->refcount = nr_probes + 1; |
| 319 | entry->multi = new; |
| 320 | entry->ptype = 1; |
| 321 | debug_print_probes(entry); |
| 322 | return old; |
| 323 | } |
| 324 | |
| 325 | static struct marker_probe_closure * |
| 326 | marker_entry_remove_probe(struct marker_entry *entry, |
| 327 | marker_probe_func *probe, void *probe_private) |
| 328 | { |
| 329 | int nr_probes = 0, nr_del = 0, i; |
| 330 | struct marker_probe_closure *old, *new; |
| 331 | |
| 332 | old = entry->multi; |
| 333 | |
| 334 | debug_print_probes(entry); |
| 335 | if (!entry->ptype) { |
| 336 | /* 0 -> N is an error */ |
| 337 | WARN_ON(entry->single.func == __mark_empty_function); |
| 338 | /* 1 -> 0 probes */ |
| 339 | WARN_ON(probe && entry->single.func != probe); |
| 340 | WARN_ON(entry->single.probe_private != probe_private); |
| 341 | entry->single.func = __mark_empty_function; |
| 342 | entry->refcount = 0; |
| 343 | entry->ptype = 0; |
| 344 | debug_print_probes(entry); |
| 345 | return NULL; |
| 346 | } else { |
| 347 | /* (N -> M), (N > 1, M >= 0) probes */ |
| 348 | for (nr_probes = 0; old[nr_probes].func; nr_probes++) { |
| 349 | if ((!probe || old[nr_probes].func == probe) |
| 350 | && old[nr_probes].probe_private |
| 351 | == probe_private) |
| 352 | nr_del++; |
| 353 | } |
| 354 | } |
| 355 | |
| 356 | if (nr_probes - nr_del == 0) { |
| 357 | /* N -> 0, (N > 1) */ |
| 358 | entry->single.func = __mark_empty_function; |
| 359 | entry->refcount = 0; |
| 360 | entry->ptype = 0; |
| 361 | } else if (nr_probes - nr_del == 1) { |
| 362 | /* N -> 1, (N > 1) */ |
| 363 | for (i = 0; old[i].func; i++) |
| 364 | if ((probe && old[i].func != probe) || |
| 365 | old[i].probe_private != probe_private) |
| 366 | entry->single = old[i]; |
| 367 | entry->refcount = 1; |
| 368 | entry->ptype = 0; |
| 369 | } else { |
| 370 | int j = 0; |
| 371 | /* N -> M, (N > 1, M > 1) */ |
| 372 | /* + 1 for NULL */ |
| 373 | new = kzalloc((nr_probes - nr_del + 1) |
| 374 | * sizeof(struct marker_probe_closure), GFP_KERNEL); |
| 375 | if (new == NULL) |
| 376 | return ERR_PTR(-ENOMEM); |
| 377 | for (i = 0; old[i].func; i++) |
| 378 | if ((probe && old[i].func != probe) || |
| 379 | old[i].probe_private != probe_private) |
| 380 | new[j++] = old[i]; |
| 381 | entry->refcount = nr_probes - nr_del; |
| 382 | entry->ptype = 1; |
| 383 | entry->multi = new; |
| 384 | } |
| 385 | debug_print_probes(entry); |
| 386 | return old; |
| 387 | } |
| 388 | |
| 389 | /* |
| 390 | * Get marker if the marker is present in the marker hash table. |
| 391 | * Must be called with markers_mutex held. |
| 392 | * Returns NULL if not present. |
| 393 | */ |
| 394 | static struct marker_entry *get_marker(const char *channel, const char *name) |
| 395 | { |
| 396 | struct hlist_head *head; |
| 397 | struct hlist_node *node; |
| 398 | struct marker_entry *e; |
| 399 | size_t channel_len = strlen(channel) + 1; |
| 400 | size_t name_len = strlen(name) + 1; |
| 401 | u32 hash; |
| 402 | |
| 403 | hash = jhash(channel, channel_len-1, 0) ^ jhash(name, name_len-1, 0); |
| 404 | head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; |
| 405 | hlist_for_each_entry(e, node, head, hlist) { |
| 406 | if (!strcmp(channel, e->channel) && !strcmp(name, e->name)) |
| 407 | return e; |
| 408 | } |
| 409 | return NULL; |
| 410 | } |
| 411 | |
| 412 | /* |
| 413 | * Add the marker to the marker hash table. Must be called with markers_mutex |
| 414 | * held. |
| 415 | */ |
| 416 | static struct marker_entry *add_marker(const char *channel, const char *name, |
| 417 | const char *format) |
| 418 | { |
| 419 | struct hlist_head *head; |
| 420 | struct hlist_node *node; |
| 421 | struct marker_entry *e; |
| 422 | size_t channel_len = strlen(channel) + 1; |
| 423 | size_t name_len = strlen(name) + 1; |
| 424 | size_t format_len = 0; |
| 425 | u32 hash; |
| 426 | |
| 427 | hash = jhash(channel, channel_len-1, 0) ^ jhash(name, name_len-1, 0); |
| 428 | if (format) |
| 429 | format_len = strlen(format) + 1; |
| 430 | head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; |
| 431 | hlist_for_each_entry(e, node, head, hlist) { |
| 432 | if (!strcmp(channel, e->channel) && !strcmp(name, e->name)) { |
| 433 | printk(KERN_NOTICE |
| 434 | "Marker %s.%s busy\n", channel, name); |
| 435 | return ERR_PTR(-EBUSY); /* Already there */ |
| 436 | } |
| 437 | } |
| 438 | /* |
| 439 | * Using kmalloc here to allocate a variable length element. Could |
| 440 | * cause some memory fragmentation if overused. |
| 441 | */ |
| 442 | e = kmalloc(sizeof(struct marker_entry) |
| 443 | + channel_len + name_len + format_len, |
| 444 | GFP_KERNEL); |
| 445 | if (!e) |
| 446 | return ERR_PTR(-ENOMEM); |
| 447 | memcpy(e->channel, channel, channel_len); |
| 448 | e->name = &e->channel[channel_len]; |
| 449 | memcpy(e->name, name, name_len); |
| 450 | if (format) { |
| 451 | e->format = &e->name[channel_len + name_len]; |
| 452 | memcpy(e->format, format, format_len); |
| 453 | if (strcmp(e->format, MARK_NOARGS) == 0) |
| 454 | e->call = marker_probe_cb_noarg; |
| 455 | else |
| 456 | e->call = marker_probe_cb; |
| 457 | trace_mark(metadata, core_marker_format, |
| 458 | "channel %s name %s format %s", |
| 459 | e->channel, e->name, e->format); |
| 460 | } else { |
| 461 | e->format = NULL; |
| 462 | e->call = marker_probe_cb; |
| 463 | } |
| 464 | e->single.func = __mark_empty_function; |
| 465 | e->single.probe_private = NULL; |
| 466 | e->multi = NULL; |
| 467 | e->ptype = 0; |
| 468 | e->format_allocated = 0; |
| 469 | e->refcount = 0; |
| 470 | e->rcu_pending = 0; |
| 471 | hlist_add_head(&e->hlist, head); |
| 472 | return e; |
| 473 | } |
| 474 | |
| 475 | /* |
| 476 | * Remove the marker from the marker hash table. Must be called with mutex_lock |
| 477 | * held. |
| 478 | */ |
| 479 | static int remove_marker(const char *channel, const char *name) |
| 480 | { |
| 481 | struct hlist_head *head; |
| 482 | struct hlist_node *node; |
| 483 | struct marker_entry *e; |
| 484 | int found = 0; |
| 485 | size_t channel_len = strlen(channel) + 1; |
| 486 | size_t name_len = strlen(name) + 1; |
| 487 | u32 hash; |
| 488 | int ret; |
| 489 | |
| 490 | hash = jhash(channel, channel_len-1, 0) ^ jhash(name, name_len-1, 0); |
| 491 | head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; |
| 492 | hlist_for_each_entry(e, node, head, hlist) { |
| 493 | if (!strcmp(channel, e->channel) && !strcmp(name, e->name)) { |
| 494 | found = 1; |
| 495 | break; |
| 496 | } |
| 497 | } |
| 498 | if (!found) |
| 499 | return -ENOENT; |
| 500 | if (e->single.func != __mark_empty_function) |
| 501 | return -EBUSY; |
| 502 | hlist_del(&e->hlist); |
| 503 | if (e->format_allocated) |
| 504 | kfree(e->format); |
| 505 | ret = ltt_channels_unregister(e->channel); |
| 506 | WARN_ON(ret); |
| 507 | /* Make sure the call_rcu has been executed */ |
| 508 | //ust// if (e->rcu_pending) |
| 509 | //ust// rcu_barrier_sched(); |
| 510 | kfree(e); |
| 511 | return 0; |
| 512 | } |
| 513 | |
| 514 | /* |
| 515 | * Set the mark_entry format to the format found in the element. |
| 516 | */ |
| 517 | static int marker_set_format(struct marker_entry *entry, const char *format) |
| 518 | { |
| 519 | entry->format = kstrdup(format, GFP_KERNEL); |
| 520 | if (!entry->format) |
| 521 | return -ENOMEM; |
| 522 | entry->format_allocated = 1; |
| 523 | |
| 524 | trace_mark(metadata, core_marker_format, |
| 525 | "channel %s name %s format %s", |
| 526 | entry->channel, entry->name, entry->format); |
| 527 | return 0; |
| 528 | } |
| 529 | |
| 530 | /* |
| 531 | * Sets the probe callback corresponding to one marker. |
| 532 | */ |
| 533 | static int set_marker(struct marker_entry *entry, struct marker *elem, |
| 534 | int active) |
| 535 | { |
| 536 | int ret = 0; |
| 537 | WARN_ON(strcmp(entry->name, elem->name) != 0); |
| 538 | |
| 539 | if (entry->format) { |
| 540 | if (strcmp(entry->format, elem->format) != 0) { |
| 541 | printk(KERN_NOTICE |
| 542 | "Format mismatch for probe %s " |
| 543 | "(%s), marker (%s)\n", |
| 544 | entry->name, |
| 545 | entry->format, |
| 546 | elem->format); |
| 547 | return -EPERM; |
| 548 | } |
| 549 | } else { |
| 550 | ret = marker_set_format(entry, elem->format); |
| 551 | if (ret) |
| 552 | return ret; |
| 553 | } |
| 554 | |
| 555 | /* |
| 556 | * probe_cb setup (statically known) is done here. It is |
| 557 | * asynchronous with the rest of execution, therefore we only |
| 558 | * pass from a "safe" callback (with argument) to an "unsafe" |
| 559 | * callback (does not set arguments). |
| 560 | */ |
| 561 | elem->call = entry->call; |
| 562 | elem->channel_id = entry->channel_id; |
| 563 | elem->event_id = entry->event_id; |
| 564 | /* |
| 565 | * Sanity check : |
| 566 | * We only update the single probe private data when the ptr is |
| 567 | * set to a _non_ single probe! (0 -> 1 and N -> 1, N != 1) |
| 568 | */ |
| 569 | WARN_ON(elem->single.func != __mark_empty_function |
| 570 | && elem->single.probe_private != entry->single.probe_private |
| 571 | && !elem->ptype); |
| 572 | elem->single.probe_private = entry->single.probe_private; |
| 573 | /* |
| 574 | * Make sure the private data is valid when we update the |
| 575 | * single probe ptr. |
| 576 | */ |
| 577 | smp_wmb(); |
| 578 | elem->single.func = entry->single.func; |
| 579 | /* |
| 580 | * We also make sure that the new probe callbacks array is consistent |
| 581 | * before setting a pointer to it. |
| 582 | */ |
| 583 | rcu_assign_pointer(elem->multi, entry->multi); |
| 584 | /* |
| 585 | * Update the function or multi probe array pointer before setting the |
| 586 | * ptype. |
| 587 | */ |
| 588 | smp_wmb(); |
| 589 | elem->ptype = entry->ptype; |
| 590 | |
| 591 | //ust// if (elem->tp_name && (active ^ _imv_read(elem->state))) { |
| 592 | //ust// WARN_ON(!elem->tp_cb); |
| 593 | //ust// /* |
| 594 | //ust// * It is ok to directly call the probe registration because type |
| 595 | //ust// * checking has been done in the __trace_mark_tp() macro. |
| 596 | //ust// */ |
| 597 | //ust// |
| 598 | //ust// if (active) { |
| 599 | //ust// /* |
| 600 | //ust// * try_module_get should always succeed because we hold |
| 601 | //ust// * markers_mutex to get the tp_cb address. |
| 602 | //ust// */ |
| 603 | //ust// ret = try_module_get(__module_text_address( |
| 604 | //ust// (unsigned long)elem->tp_cb)); |
| 605 | //ust// BUG_ON(!ret); |
| 606 | //ust// ret = tracepoint_probe_register_noupdate( |
| 607 | //ust// elem->tp_name, |
| 608 | //ust// elem->tp_cb); |
| 609 | //ust// } else { |
| 610 | //ust// ret = tracepoint_probe_unregister_noupdate( |
| 611 | //ust// elem->tp_name, |
| 612 | //ust// elem->tp_cb); |
| 613 | //ust// /* |
| 614 | //ust// * tracepoint_probe_update_all() must be called |
| 615 | //ust// * before the module containing tp_cb is unloaded. |
| 616 | //ust// */ |
| 617 | //ust// module_put(__module_text_address( |
| 618 | //ust// (unsigned long)elem->tp_cb)); |
| 619 | //ust// } |
| 620 | //ust// } |
| 621 | elem->state__imv = active; |
| 622 | |
| 623 | return ret; |
| 624 | } |
| 625 | |
| 626 | /* |
| 627 | * Disable a marker and its probe callback. |
| 628 | * Note: only waiting an RCU period after setting elem->call to the empty |
| 629 | * function insures that the original callback is not used anymore. This insured |
| 630 | * by rcu_read_lock_sched around the call site. |
| 631 | */ |
| 632 | static void disable_marker(struct marker *elem) |
| 633 | { |
| 634 | int ret; |
| 635 | |
| 636 | /* leave "call" as is. It is known statically. */ |
| 637 | //ust// if (elem->tp_name && _imv_read(elem->state)) { |
| 638 | //ust// WARN_ON(!elem->tp_cb); |
| 639 | //ust// /* |
| 640 | //ust// * It is ok to directly call the probe registration because type |
| 641 | //ust// * checking has been done in the __trace_mark_tp() macro. |
| 642 | //ust// */ |
| 643 | //ust// ret = tracepoint_probe_unregister_noupdate(elem->tp_name, |
| 644 | //ust// elem->tp_cb); |
| 645 | //ust// WARN_ON(ret); |
| 646 | //ust// /* |
| 647 | //ust// * tracepoint_probe_update_all() must be called |
| 648 | //ust// * before the module containing tp_cb is unloaded. |
| 649 | //ust// */ |
| 650 | //ust// module_put(__module_text_address((unsigned long)elem->tp_cb)); |
| 651 | //ust// } |
| 652 | elem->state__imv = 0; |
| 653 | elem->single.func = __mark_empty_function; |
| 654 | /* Update the function before setting the ptype */ |
| 655 | smp_wmb(); |
| 656 | elem->ptype = 0; /* single probe */ |
| 657 | /* |
| 658 | * Leave the private data and channel_id/event_id there, because removal |
| 659 | * is racy and should be done only after an RCU period. These are never |
| 660 | * used until the next initialization anyway. |
| 661 | */ |
| 662 | } |
| 663 | |
| 664 | /** |
| 665 | * marker_update_probe_range - Update a probe range |
| 666 | * @begin: beginning of the range |
| 667 | * @end: end of the range |
| 668 | * |
| 669 | * Updates the probe callback corresponding to a range of markers. |
| 670 | */ |
| 671 | void marker_update_probe_range(struct marker *begin, |
| 672 | struct marker *end) |
| 673 | { |
| 674 | struct marker *iter; |
| 675 | struct marker_entry *mark_entry; |
| 676 | |
| 677 | mutex_lock(&markers_mutex); |
| 678 | for (iter = begin; iter < end; iter++) { |
| 679 | mark_entry = get_marker(iter->channel, iter->name); |
| 680 | if (mark_entry) { |
| 681 | set_marker(mark_entry, iter, !!mark_entry->refcount); |
| 682 | /* |
| 683 | * ignore error, continue |
| 684 | */ |
| 685 | |
| 686 | /* This is added for UST. We emit a core_marker_id event |
| 687 | * for markers that are already registered to a probe |
| 688 | * upon library load. Otherwise, no core_marker_id will |
| 689 | * be generated for these markers. Is this the right thing |
| 690 | * to do? |
| 691 | */ |
| 692 | trace_mark(metadata, core_marker_id, |
| 693 | "channel %s name %s event_id %hu " |
| 694 | "int #1u%zu long #1u%zu pointer #1u%zu " |
| 695 | "size_t #1u%zu alignment #1u%u", |
| 696 | iter->channel, iter->name, mark_entry->event_id, |
| 697 | sizeof(int), sizeof(long), sizeof(void *), |
| 698 | sizeof(size_t), ltt_get_alignment()); |
| 699 | } else { |
| 700 | disable_marker(iter); |
| 701 | } |
| 702 | } |
| 703 | mutex_unlock(&markers_mutex); |
| 704 | } |
| 705 | |
| 706 | /* |
| 707 | * Update probes, removing the faulty probes. |
| 708 | * |
| 709 | * Internal callback only changed before the first probe is connected to it. |
| 710 | * Single probe private data can only be changed on 0 -> 1 and 2 -> 1 |
| 711 | * transitions. All other transitions will leave the old private data valid. |
| 712 | * This makes the non-atomicity of the callback/private data updates valid. |
| 713 | * |
| 714 | * "special case" updates : |
| 715 | * 0 -> 1 callback |
| 716 | * 1 -> 0 callback |
| 717 | * 1 -> 2 callbacks |
| 718 | * 2 -> 1 callbacks |
| 719 | * Other updates all behave the same, just like the 2 -> 3 or 3 -> 2 updates. |
| 720 | * Site effect : marker_set_format may delete the marker entry (creating a |
| 721 | * replacement). |
| 722 | */ |
| 723 | static void marker_update_probes(void) |
| 724 | { |
| 725 | /* Core kernel markers */ |
| 726 | //ust// marker_update_probe_range(__start___markers, __stop___markers); |
| 727 | /* Markers in modules. */ |
| 728 | //ust// module_update_markers(); |
| 729 | lib_update_markers(); |
| 730 | //ust// tracepoint_probe_update_all(); |
| 731 | /* Update immediate values */ |
| 732 | core_imv_update(); |
| 733 | //ust// module_imv_update(); /* FIXME: need to port for libs? */ |
| 734 | marker_update_processes(); |
| 735 | } |
| 736 | |
| 737 | /** |
| 738 | * marker_probe_register - Connect a probe to a marker |
| 739 | * @channel: marker channel |
| 740 | * @name: marker name |
| 741 | * @format: format string |
| 742 | * @probe: probe handler |
| 743 | * @probe_private: probe private data |
| 744 | * |
| 745 | * private data must be a valid allocated memory address, or NULL. |
| 746 | * Returns 0 if ok, error value on error. |
| 747 | * The probe address must at least be aligned on the architecture pointer size. |
| 748 | */ |
| 749 | int marker_probe_register(const char *channel, const char *name, |
| 750 | const char *format, marker_probe_func *probe, |
| 751 | void *probe_private) |
| 752 | { |
| 753 | struct marker_entry *entry; |
| 754 | int ret = 0, ret_err; |
| 755 | struct marker_probe_closure *old; |
| 756 | int first_probe = 0; |
| 757 | |
| 758 | mutex_lock(&markers_mutex); |
| 759 | entry = get_marker(channel, name); |
| 760 | if (!entry) { |
| 761 | first_probe = 1; |
| 762 | entry = add_marker(channel, name, format); |
| 763 | if (IS_ERR(entry)) |
| 764 | ret = PTR_ERR(entry); |
| 765 | if (ret) |
| 766 | goto end; |
| 767 | ret = ltt_channels_register(channel); |
| 768 | if (ret) |
| 769 | goto error_remove_marker; |
| 770 | ret = ltt_channels_get_index_from_name(channel); |
| 771 | if (ret < 0) |
| 772 | goto error_unregister_channel; |
| 773 | entry->channel_id = ret; |
| 774 | ret = ltt_channels_get_event_id(channel, name); |
| 775 | if (ret < 0) |
| 776 | goto error_unregister_channel; |
| 777 | entry->event_id = ret; |
| 778 | ret = 0; |
| 779 | trace_mark(metadata, core_marker_id, |
| 780 | "channel %s name %s event_id %hu " |
| 781 | "int #1u%zu long #1u%zu pointer #1u%zu " |
| 782 | "size_t #1u%zu alignment #1u%u", |
| 783 | channel, name, entry->event_id, |
| 784 | sizeof(int), sizeof(long), sizeof(void *), |
| 785 | sizeof(size_t), ltt_get_alignment()); |
| 786 | } else if (format) { |
| 787 | if (!entry->format) |
| 788 | ret = marker_set_format(entry, format); |
| 789 | else if (strcmp(entry->format, format)) |
| 790 | ret = -EPERM; |
| 791 | if (ret) |
| 792 | goto end; |
| 793 | } |
| 794 | |
| 795 | /* |
| 796 | * If we detect that a call_rcu is pending for this marker, |
| 797 | * make sure it's executed now. |
| 798 | */ |
| 799 | //ust// if (entry->rcu_pending) |
| 800 | //ust// rcu_barrier_sched(); |
| 801 | old = marker_entry_add_probe(entry, probe, probe_private); |
| 802 | if (IS_ERR(old)) { |
| 803 | ret = PTR_ERR(old); |
| 804 | if (first_probe) |
| 805 | goto error_unregister_channel; |
| 806 | else |
| 807 | goto end; |
| 808 | } |
| 809 | mutex_unlock(&markers_mutex); |
| 810 | |
| 811 | marker_update_probes(); |
| 812 | |
| 813 | mutex_lock(&markers_mutex); |
| 814 | entry = get_marker(channel, name); |
| 815 | if (!entry) |
| 816 | goto end; |
| 817 | //ust// if (entry->rcu_pending) |
| 818 | //ust// rcu_barrier_sched(); |
| 819 | entry->oldptr = old; |
| 820 | entry->rcu_pending = 1; |
| 821 | /* write rcu_pending before calling the RCU callback */ |
| 822 | smp_wmb(); |
| 823 | //ust// call_rcu_sched(&entry->rcu, free_old_closure); |
| 824 | synchronize_rcu(); free_old_closure(&entry->rcu); |
| 825 | goto end; |
| 826 | |
| 827 | error_unregister_channel: |
| 828 | ret_err = ltt_channels_unregister(channel); |
| 829 | WARN_ON(ret_err); |
| 830 | error_remove_marker: |
| 831 | ret_err = remove_marker(channel, name); |
| 832 | WARN_ON(ret_err); |
| 833 | end: |
| 834 | mutex_unlock(&markers_mutex); |
| 835 | return ret; |
| 836 | } |
| 837 | //ust// EXPORT_SYMBOL_GPL(marker_probe_register); |
| 838 | |
| 839 | /** |
| 840 | * marker_probe_unregister - Disconnect a probe from a marker |
| 841 | * @channel: marker channel |
| 842 | * @name: marker name |
| 843 | * @probe: probe function pointer |
| 844 | * @probe_private: probe private data |
| 845 | * |
| 846 | * Returns the private data given to marker_probe_register, or an ERR_PTR(). |
| 847 | * We do not need to call a synchronize_sched to make sure the probes have |
| 848 | * finished running before doing a module unload, because the module unload |
| 849 | * itself uses stop_machine(), which insures that every preempt disabled section |
| 850 | * have finished. |
| 851 | */ |
| 852 | int marker_probe_unregister(const char *channel, const char *name, |
| 853 | marker_probe_func *probe, void *probe_private) |
| 854 | { |
| 855 | struct marker_entry *entry; |
| 856 | struct marker_probe_closure *old; |
| 857 | int ret = -ENOENT; |
| 858 | |
| 859 | mutex_lock(&markers_mutex); |
| 860 | entry = get_marker(channel, name); |
| 861 | if (!entry) |
| 862 | goto end; |
| 863 | //ust// if (entry->rcu_pending) |
| 864 | //ust// rcu_barrier_sched(); |
| 865 | old = marker_entry_remove_probe(entry, probe, probe_private); |
| 866 | mutex_unlock(&markers_mutex); |
| 867 | |
| 868 | marker_update_probes(); |
| 869 | |
| 870 | mutex_lock(&markers_mutex); |
| 871 | entry = get_marker(channel, name); |
| 872 | if (!entry) |
| 873 | goto end; |
| 874 | //ust// if (entry->rcu_pending) |
| 875 | //ust// rcu_barrier_sched(); |
| 876 | entry->oldptr = old; |
| 877 | entry->rcu_pending = 1; |
| 878 | /* write rcu_pending before calling the RCU callback */ |
| 879 | smp_wmb(); |
| 880 | //ust// call_rcu_sched(&entry->rcu, free_old_closure); |
| 881 | synchronize_rcu(); free_old_closure(&entry->rcu); |
| 882 | remove_marker(channel, name); /* Ignore busy error message */ |
| 883 | ret = 0; |
| 884 | end: |
| 885 | mutex_unlock(&markers_mutex); |
| 886 | return ret; |
| 887 | } |
| 888 | //ust// EXPORT_SYMBOL_GPL(marker_probe_unregister); |
| 889 | |
| 890 | static struct marker_entry * |
| 891 | get_marker_from_private_data(marker_probe_func *probe, void *probe_private) |
| 892 | { |
| 893 | struct marker_entry *entry; |
| 894 | unsigned int i; |
| 895 | struct hlist_head *head; |
| 896 | struct hlist_node *node; |
| 897 | |
| 898 | for (i = 0; i < MARKER_TABLE_SIZE; i++) { |
| 899 | head = &marker_table[i]; |
| 900 | hlist_for_each_entry(entry, node, head, hlist) { |
| 901 | if (!entry->ptype) { |
| 902 | if (entry->single.func == probe |
| 903 | && entry->single.probe_private |
| 904 | == probe_private) |
| 905 | return entry; |
| 906 | } else { |
| 907 | struct marker_probe_closure *closure; |
| 908 | closure = entry->multi; |
| 909 | for (i = 0; closure[i].func; i++) { |
| 910 | if (closure[i].func == probe && |
| 911 | closure[i].probe_private |
| 912 | == probe_private) |
| 913 | return entry; |
| 914 | } |
| 915 | } |
| 916 | } |
| 917 | } |
| 918 | return NULL; |
| 919 | } |
| 920 | |
| 921 | /** |
| 922 | * marker_probe_unregister_private_data - Disconnect a probe from a marker |
| 923 | * @probe: probe function |
| 924 | * @probe_private: probe private data |
| 925 | * |
| 926 | * Unregister a probe by providing the registered private data. |
| 927 | * Only removes the first marker found in hash table. |
| 928 | * Return 0 on success or error value. |
| 929 | * We do not need to call a synchronize_sched to make sure the probes have |
| 930 | * finished running before doing a module unload, because the module unload |
| 931 | * itself uses stop_machine(), which insures that every preempt disabled section |
| 932 | * have finished. |
| 933 | */ |
| 934 | int marker_probe_unregister_private_data(marker_probe_func *probe, |
| 935 | void *probe_private) |
| 936 | { |
| 937 | struct marker_entry *entry; |
| 938 | int ret = 0; |
| 939 | struct marker_probe_closure *old; |
| 940 | const char *channel = NULL, *name = NULL; |
| 941 | |
| 942 | mutex_lock(&markers_mutex); |
| 943 | entry = get_marker_from_private_data(probe, probe_private); |
| 944 | if (!entry) { |
| 945 | ret = -ENOENT; |
| 946 | goto end; |
| 947 | } |
| 948 | //ust// if (entry->rcu_pending) |
| 949 | //ust// rcu_barrier_sched(); |
| 950 | old = marker_entry_remove_probe(entry, NULL, probe_private); |
| 951 | channel = kstrdup(entry->channel, GFP_KERNEL); |
| 952 | name = kstrdup(entry->name, GFP_KERNEL); |
| 953 | mutex_unlock(&markers_mutex); |
| 954 | |
| 955 | marker_update_probes(); |
| 956 | |
| 957 | mutex_lock(&markers_mutex); |
| 958 | entry = get_marker(channel, name); |
| 959 | if (!entry) |
| 960 | goto end; |
| 961 | //ust// if (entry->rcu_pending) |
| 962 | //ust// rcu_barrier_sched(); |
| 963 | entry->oldptr = old; |
| 964 | entry->rcu_pending = 1; |
| 965 | /* write rcu_pending before calling the RCU callback */ |
| 966 | smp_wmb(); |
| 967 | //ust// call_rcu_sched(&entry->rcu, free_old_closure); |
| 968 | synchronize_rcu(); free_old_closure(&entry->rcu); |
| 969 | /* Ignore busy error message */ |
| 970 | remove_marker(channel, name); |
| 971 | end: |
| 972 | mutex_unlock(&markers_mutex); |
| 973 | kfree(channel); |
| 974 | kfree(name); |
| 975 | return ret; |
| 976 | } |
| 977 | //ust// EXPORT_SYMBOL_GPL(marker_probe_unregister_private_data); |
| 978 | |
| 979 | /** |
| 980 | * marker_get_private_data - Get a marker's probe private data |
| 981 | * @channel: marker channel |
| 982 | * @name: marker name |
| 983 | * @probe: probe to match |
| 984 | * @num: get the nth matching probe's private data |
| 985 | * |
| 986 | * Returns the nth private data pointer (starting from 0) matching, or an |
| 987 | * ERR_PTR. |
| 988 | * Returns the private data pointer, or an ERR_PTR. |
| 989 | * The private data pointer should _only_ be dereferenced if the caller is the |
| 990 | * owner of the data, or its content could vanish. This is mostly used to |
| 991 | * confirm that a caller is the owner of a registered probe. |
| 992 | */ |
| 993 | void *marker_get_private_data(const char *channel, const char *name, |
| 994 | marker_probe_func *probe, int num) |
| 995 | { |
| 996 | struct hlist_head *head; |
| 997 | struct hlist_node *node; |
| 998 | struct marker_entry *e; |
| 999 | size_t channel_len = strlen(channel) + 1; |
| 1000 | size_t name_len = strlen(name) + 1; |
| 1001 | int i; |
| 1002 | u32 hash; |
| 1003 | |
| 1004 | hash = jhash(channel, channel_len-1, 0) ^ jhash(name, name_len-1, 0); |
| 1005 | head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; |
| 1006 | hlist_for_each_entry(e, node, head, hlist) { |
| 1007 | if (!strcmp(channel, e->channel) && !strcmp(name, e->name)) { |
| 1008 | if (!e->ptype) { |
| 1009 | if (num == 0 && e->single.func == probe) |
| 1010 | return e->single.probe_private; |
| 1011 | } else { |
| 1012 | struct marker_probe_closure *closure; |
| 1013 | int match = 0; |
| 1014 | closure = e->multi; |
| 1015 | for (i = 0; closure[i].func; i++) { |
| 1016 | if (closure[i].func != probe) |
| 1017 | continue; |
| 1018 | if (match++ == num) |
| 1019 | return closure[i].probe_private; |
| 1020 | } |
| 1021 | } |
| 1022 | break; |
| 1023 | } |
| 1024 | } |
| 1025 | return ERR_PTR(-ENOENT); |
| 1026 | } |
| 1027 | //ust// EXPORT_SYMBOL_GPL(marker_get_private_data); |
| 1028 | |
| 1029 | /** |
| 1030 | * markers_compact_event_ids - Compact markers event IDs and reassign channels |
| 1031 | * |
| 1032 | * Called when no channel users are active by the channel infrastructure. |
| 1033 | * Called with lock_markers() and channel mutex held. |
| 1034 | */ |
| 1035 | //ust// void markers_compact_event_ids(void) |
| 1036 | //ust// { |
| 1037 | //ust// struct marker_entry *entry; |
| 1038 | //ust// unsigned int i; |
| 1039 | //ust// struct hlist_head *head; |
| 1040 | //ust// struct hlist_node *node; |
| 1041 | //ust// int ret; |
| 1042 | //ust// |
| 1043 | //ust// for (i = 0; i < MARKER_TABLE_SIZE; i++) { |
| 1044 | //ust// head = &marker_table[i]; |
| 1045 | //ust// hlist_for_each_entry(entry, node, head, hlist) { |
| 1046 | //ust// ret = ltt_channels_get_index_from_name(entry->channel); |
| 1047 | //ust// WARN_ON(ret < 0); |
| 1048 | //ust// entry->channel_id = ret; |
| 1049 | //ust// ret = _ltt_channels_get_event_id(entry->channel, |
| 1050 | //ust// entry->name); |
| 1051 | //ust// WARN_ON(ret < 0); |
| 1052 | //ust// entry->event_id = ret; |
| 1053 | //ust// } |
| 1054 | //ust// } |
| 1055 | //ust// } |
| 1056 | |
| 1057 | //ust//#ifdef CONFIG_MODULES |
| 1058 | |
| 1059 | /** |
| 1060 | * marker_get_iter_range - Get a next marker iterator given a range. |
| 1061 | * @marker: current markers (in), next marker (out) |
| 1062 | * @begin: beginning of the range |
| 1063 | * @end: end of the range |
| 1064 | * |
| 1065 | * Returns whether a next marker has been found (1) or not (0). |
| 1066 | * Will return the first marker in the range if the input marker is NULL. |
| 1067 | */ |
| 1068 | int marker_get_iter_range(struct marker **marker, struct marker *begin, |
| 1069 | struct marker *end) |
| 1070 | { |
| 1071 | if (!*marker && begin != end) { |
| 1072 | *marker = begin; |
| 1073 | return 1; |
| 1074 | } |
| 1075 | if (*marker >= begin && *marker < end) |
| 1076 | return 1; |
| 1077 | return 0; |
| 1078 | } |
| 1079 | //ust// EXPORT_SYMBOL_GPL(marker_get_iter_range); |
| 1080 | |
| 1081 | static void marker_get_iter(struct marker_iter *iter) |
| 1082 | { |
| 1083 | int found = 0; |
| 1084 | |
| 1085 | /* Core kernel markers */ |
| 1086 | if (!iter->lib) { |
| 1087 | /* ust FIXME: how come we cannot disable the following line? we shouldn't need core stuff */ |
| 1088 | found = marker_get_iter_range(&iter->marker, |
| 1089 | __start___markers, __stop___markers); |
| 1090 | if (found) |
| 1091 | goto end; |
| 1092 | } |
| 1093 | /* Markers in modules. */ |
| 1094 | found = lib_get_iter_markers(iter); |
| 1095 | end: |
| 1096 | if (!found) |
| 1097 | marker_iter_reset(iter); |
| 1098 | } |
| 1099 | |
| 1100 | void marker_iter_start(struct marker_iter *iter) |
| 1101 | { |
| 1102 | marker_get_iter(iter); |
| 1103 | } |
| 1104 | //ust// EXPORT_SYMBOL_GPL(marker_iter_start); |
| 1105 | |
| 1106 | void marker_iter_next(struct marker_iter *iter) |
| 1107 | { |
| 1108 | iter->marker++; |
| 1109 | /* |
| 1110 | * iter->marker may be invalid because we blindly incremented it. |
| 1111 | * Make sure it is valid by marshalling on the markers, getting the |
| 1112 | * markers from following modules if necessary. |
| 1113 | */ |
| 1114 | marker_get_iter(iter); |
| 1115 | } |
| 1116 | //ust// EXPORT_SYMBOL_GPL(marker_iter_next); |
| 1117 | |
| 1118 | void marker_iter_stop(struct marker_iter *iter) |
| 1119 | { |
| 1120 | } |
| 1121 | //ust// EXPORT_SYMBOL_GPL(marker_iter_stop); |
| 1122 | |
| 1123 | void marker_iter_reset(struct marker_iter *iter) |
| 1124 | { |
| 1125 | iter->lib = NULL; |
| 1126 | iter->marker = NULL; |
| 1127 | } |
| 1128 | //ust// EXPORT_SYMBOL_GPL(marker_iter_reset); |
| 1129 | |
| 1130 | #ifdef CONFIG_MARKERS_USERSPACE |
| 1131 | /* |
| 1132 | * must be called with current->user_markers_mutex held |
| 1133 | */ |
| 1134 | static void free_user_marker(char __user *state, struct hlist_head *head) |
| 1135 | { |
| 1136 | struct user_marker *umark; |
| 1137 | struct hlist_node *pos, *n; |
| 1138 | |
| 1139 | hlist_for_each_entry_safe(umark, pos, n, head, hlist) { |
| 1140 | if (umark->state == state) { |
| 1141 | hlist_del(&umark->hlist); |
| 1142 | kfree(umark); |
| 1143 | } |
| 1144 | } |
| 1145 | } |
| 1146 | |
| 1147 | //ust// asmlinkage long sys_marker(char __user *name, char __user *format, |
| 1148 | //ust// char __user *state, int reg) |
| 1149 | //ust// { |
| 1150 | //ust// struct user_marker *umark; |
| 1151 | //ust// long len; |
| 1152 | //ust// struct marker_entry *entry; |
| 1153 | //ust// int ret = 0; |
| 1154 | //ust// |
| 1155 | //ust// printk(KERN_DEBUG "Program %s %s marker [%p, %p]\n", |
| 1156 | //ust// current->comm, reg ? "registers" : "unregisters", |
| 1157 | //ust// name, state); |
| 1158 | //ust// if (reg) { |
| 1159 | //ust// umark = kmalloc(sizeof(struct user_marker), GFP_KERNEL); |
| 1160 | //ust// umark->name[MAX_USER_MARKER_NAME_LEN - 1] = '\0'; |
| 1161 | //ust// umark->format[MAX_USER_MARKER_FORMAT_LEN - 1] = '\0'; |
| 1162 | //ust// umark->state = state; |
| 1163 | //ust// len = strncpy_from_user(umark->name, name, |
| 1164 | //ust// MAX_USER_MARKER_NAME_LEN - 1); |
| 1165 | //ust// if (len < 0) { |
| 1166 | //ust// ret = -EFAULT; |
| 1167 | //ust// goto error; |
| 1168 | //ust// } |
| 1169 | //ust// len = strncpy_from_user(umark->format, format, |
| 1170 | //ust// MAX_USER_MARKER_FORMAT_LEN - 1); |
| 1171 | //ust// if (len < 0) { |
| 1172 | //ust// ret = -EFAULT; |
| 1173 | //ust// goto error; |
| 1174 | //ust// } |
| 1175 | //ust// printk(KERN_DEBUG "Marker name : %s, format : %s", umark->name, |
| 1176 | //ust// umark->format); |
| 1177 | //ust// mutex_lock(&markers_mutex); |
| 1178 | //ust// entry = get_marker("userspace", umark->name); |
| 1179 | //ust// if (entry) { |
| 1180 | //ust// if (entry->format && |
| 1181 | //ust// strcmp(entry->format, umark->format) != 0) { |
| 1182 | //ust// printk(" error, wrong format in process %s", |
| 1183 | //ust// current->comm); |
| 1184 | //ust// ret = -EPERM; |
| 1185 | //ust// goto error_unlock; |
| 1186 | //ust// } |
| 1187 | //ust// printk(" %s", !!entry->refcount |
| 1188 | //ust// ? "enabled" : "disabled"); |
| 1189 | //ust// if (put_user(!!entry->refcount, state)) { |
| 1190 | //ust// ret = -EFAULT; |
| 1191 | //ust// goto error_unlock; |
| 1192 | //ust// } |
| 1193 | //ust// printk("\n"); |
| 1194 | //ust// } else { |
| 1195 | //ust// printk(" disabled\n"); |
| 1196 | //ust// if (put_user(0, umark->state)) { |
| 1197 | //ust// printk(KERN_WARNING |
| 1198 | //ust// "Marker in %s caused a fault\n", |
| 1199 | //ust// current->comm); |
| 1200 | //ust// goto error_unlock; |
| 1201 | //ust// } |
| 1202 | //ust// } |
| 1203 | //ust// mutex_lock(¤t->group_leader->user_markers_mutex); |
| 1204 | //ust// hlist_add_head(&umark->hlist, |
| 1205 | //ust// ¤t->group_leader->user_markers); |
| 1206 | //ust// current->group_leader->user_markers_sequence++; |
| 1207 | //ust// mutex_unlock(¤t->group_leader->user_markers_mutex); |
| 1208 | //ust// mutex_unlock(&markers_mutex); |
| 1209 | //ust// } else { |
| 1210 | //ust// mutex_lock(¤t->group_leader->user_markers_mutex); |
| 1211 | //ust// free_user_marker(state, |
| 1212 | //ust// ¤t->group_leader->user_markers); |
| 1213 | //ust// current->group_leader->user_markers_sequence++; |
| 1214 | //ust// mutex_unlock(¤t->group_leader->user_markers_mutex); |
| 1215 | //ust// } |
| 1216 | //ust// goto end; |
| 1217 | //ust// error_unlock: |
| 1218 | //ust// mutex_unlock(&markers_mutex); |
| 1219 | //ust// error: |
| 1220 | //ust// kfree(umark); |
| 1221 | //ust// end: |
| 1222 | //ust// return ret; |
| 1223 | //ust// } |
| 1224 | //ust// |
| 1225 | //ust// /* |
| 1226 | //ust// * Types : |
| 1227 | //ust// * string : 0 |
| 1228 | //ust// */ |
| 1229 | //ust// asmlinkage long sys_trace(int type, uint16_t id, |
| 1230 | //ust// char __user *ubuf) |
| 1231 | //ust// { |
| 1232 | //ust// long ret = -EPERM; |
| 1233 | //ust// char *page; |
| 1234 | //ust// int len; |
| 1235 | //ust// |
| 1236 | //ust// switch (type) { |
| 1237 | //ust// case 0: /* String */ |
| 1238 | //ust// ret = -ENOMEM; |
| 1239 | //ust// page = (char *)__get_free_page(GFP_TEMPORARY); |
| 1240 | //ust// if (!page) |
| 1241 | //ust// goto string_out; |
| 1242 | //ust// len = strncpy_from_user(page, ubuf, PAGE_SIZE); |
| 1243 | //ust// if (len < 0) { |
| 1244 | //ust// ret = -EFAULT; |
| 1245 | //ust// goto string_err; |
| 1246 | //ust// } |
| 1247 | //ust// trace_mark(userspace, string, "string %s", page); |
| 1248 | //ust// string_err: |
| 1249 | //ust// free_page((unsigned long) page); |
| 1250 | //ust// string_out: |
| 1251 | //ust// break; |
| 1252 | //ust// default: |
| 1253 | //ust// break; |
| 1254 | //ust// } |
| 1255 | //ust// return ret; |
| 1256 | //ust// } |
| 1257 | |
| 1258 | //ust// static void marker_update_processes(void) |
| 1259 | //ust// { |
| 1260 | //ust// struct task_struct *g, *t; |
| 1261 | //ust// |
| 1262 | //ust// /* |
| 1263 | //ust// * markers_mutex is taken to protect the p->user_markers read. |
| 1264 | //ust// */ |
| 1265 | //ust// mutex_lock(&markers_mutex); |
| 1266 | //ust// read_lock(&tasklist_lock); |
| 1267 | //ust// for_each_process(g) { |
| 1268 | //ust// WARN_ON(!thread_group_leader(g)); |
| 1269 | //ust// if (hlist_empty(&g->user_markers)) |
| 1270 | //ust// continue; |
| 1271 | //ust// if (strcmp(g->comm, "testprog") == 0) |
| 1272 | //ust// printk(KERN_DEBUG "set update pending for testprog\n"); |
| 1273 | //ust// t = g; |
| 1274 | //ust// do { |
| 1275 | //ust// /* TODO : implement this thread flag in each arch. */ |
| 1276 | //ust// set_tsk_thread_flag(t, TIF_MARKER_PENDING); |
| 1277 | //ust// } while ((t = next_thread(t)) != g); |
| 1278 | //ust// } |
| 1279 | //ust// read_unlock(&tasklist_lock); |
| 1280 | //ust// mutex_unlock(&markers_mutex); |
| 1281 | //ust// } |
| 1282 | |
| 1283 | /* |
| 1284 | * Update current process. |
| 1285 | * Note that we have to wait a whole scheduler period before we are sure that |
| 1286 | * every running userspace threads have their markers updated. |
| 1287 | * (synchronize_sched() can be used to insure this). |
| 1288 | */ |
| 1289 | void marker_update_process(void) |
| 1290 | { |
| 1291 | struct user_marker *umark; |
| 1292 | struct hlist_node *pos; |
| 1293 | struct marker_entry *entry; |
| 1294 | |
| 1295 | mutex_lock(&markers_mutex); |
| 1296 | mutex_lock(¤t->group_leader->user_markers_mutex); |
| 1297 | if (strcmp(current->comm, "testprog") == 0) |
| 1298 | printk(KERN_DEBUG "do update pending for testprog\n"); |
| 1299 | hlist_for_each_entry(umark, pos, |
| 1300 | ¤t->group_leader->user_markers, hlist) { |
| 1301 | printk(KERN_DEBUG "Updating marker %s in %s\n", |
| 1302 | umark->name, current->comm); |
| 1303 | entry = get_marker("userspace", umark->name); |
| 1304 | if (entry) { |
| 1305 | if (entry->format && |
| 1306 | strcmp(entry->format, umark->format) != 0) { |
| 1307 | printk(KERN_WARNING |
| 1308 | " error, wrong format in process %s\n", |
| 1309 | current->comm); |
| 1310 | break; |
| 1311 | } |
| 1312 | if (put_user(!!entry->refcount, umark->state)) { |
| 1313 | printk(KERN_WARNING |
| 1314 | "Marker in %s caused a fault\n", |
| 1315 | current->comm); |
| 1316 | break; |
| 1317 | } |
| 1318 | } else { |
| 1319 | if (put_user(0, umark->state)) { |
| 1320 | printk(KERN_WARNING |
| 1321 | "Marker in %s caused a fault\n", |
| 1322 | current->comm); |
| 1323 | break; |
| 1324 | } |
| 1325 | } |
| 1326 | } |
| 1327 | clear_thread_flag(TIF_MARKER_PENDING); |
| 1328 | mutex_unlock(¤t->group_leader->user_markers_mutex); |
| 1329 | mutex_unlock(&markers_mutex); |
| 1330 | } |
| 1331 | |
| 1332 | /* |
| 1333 | * Called at process exit and upon do_execve(). |
| 1334 | * We assume that when the leader exits, no more references can be done to the |
| 1335 | * leader structure by the other threads. |
| 1336 | */ |
| 1337 | void exit_user_markers(struct task_struct *p) |
| 1338 | { |
| 1339 | struct user_marker *umark; |
| 1340 | struct hlist_node *pos, *n; |
| 1341 | |
| 1342 | if (thread_group_leader(p)) { |
| 1343 | mutex_lock(&markers_mutex); |
| 1344 | mutex_lock(&p->user_markers_mutex); |
| 1345 | hlist_for_each_entry_safe(umark, pos, n, &p->user_markers, |
| 1346 | hlist) |
| 1347 | kfree(umark); |
| 1348 | INIT_HLIST_HEAD(&p->user_markers); |
| 1349 | p->user_markers_sequence++; |
| 1350 | mutex_unlock(&p->user_markers_mutex); |
| 1351 | mutex_unlock(&markers_mutex); |
| 1352 | } |
| 1353 | } |
| 1354 | |
| 1355 | int is_marker_enabled(const char *channel, const char *name) |
| 1356 | { |
| 1357 | struct marker_entry *entry; |
| 1358 | |
| 1359 | mutex_lock(&markers_mutex); |
| 1360 | entry = get_marker(channel, name); |
| 1361 | mutex_unlock(&markers_mutex); |
| 1362 | |
| 1363 | return entry && !!entry->refcount; |
| 1364 | } |
| 1365 | //ust// #endif |
| 1366 | |
| 1367 | int marker_module_notify(struct notifier_block *self, |
| 1368 | unsigned long val, void *data) |
| 1369 | { |
| 1370 | struct module *mod = data; |
| 1371 | |
| 1372 | switch (val) { |
| 1373 | case MODULE_STATE_COMING: |
| 1374 | marker_update_probe_range(mod->markers, |
| 1375 | mod->markers + mod->num_markers); |
| 1376 | break; |
| 1377 | case MODULE_STATE_GOING: |
| 1378 | marker_update_probe_range(mod->markers, |
| 1379 | mod->markers + mod->num_markers); |
| 1380 | break; |
| 1381 | } |
| 1382 | return 0; |
| 1383 | } |
| 1384 | |
| 1385 | struct notifier_block marker_module_nb = { |
| 1386 | .notifier_call = marker_module_notify, |
| 1387 | .priority = 0, |
| 1388 | }; |
| 1389 | |
| 1390 | //ust// static int init_markers(void) |
| 1391 | //ust// { |
| 1392 | //ust// return register_module_notifier(&marker_module_nb); |
| 1393 | //ust// } |
| 1394 | //ust// __initcall(init_markers); |
| 1395 | /* TODO: call marker_module_nb() when a library is linked at runtime (dlopen)? */ |
| 1396 | |
| 1397 | #endif /* CONFIG_MODULES */ |
| 1398 | |
| 1399 | void ltt_dump_marker_state(struct ltt_trace_struct *trace) |
| 1400 | { |
| 1401 | struct marker_iter iter; |
| 1402 | struct ltt_probe_private_data call_data; |
| 1403 | const char *channel; |
| 1404 | |
| 1405 | call_data.trace = trace; |
| 1406 | call_data.serializer = NULL; |
| 1407 | |
| 1408 | marker_iter_reset(&iter); |
| 1409 | marker_iter_start(&iter); |
| 1410 | for (; iter.marker != NULL; marker_iter_next(&iter)) { |
| 1411 | if (!_imv_read(iter.marker->state)) |
| 1412 | continue; |
| 1413 | channel = ltt_channels_get_name_from_index( |
| 1414 | iter.marker->channel_id); |
| 1415 | __trace_mark(0, metadata, core_marker_id, |
| 1416 | &call_data, |
| 1417 | "channel %s name %s event_id %hu " |
| 1418 | "int #1u%zu long #1u%zu pointer #1u%zu " |
| 1419 | "size_t #1u%zu alignment #1u%u", |
| 1420 | channel, |
| 1421 | iter.marker->name, |
| 1422 | iter.marker->event_id, |
| 1423 | sizeof(int), sizeof(long), |
| 1424 | sizeof(void *), sizeof(size_t), |
| 1425 | ltt_get_alignment()); |
| 1426 | if (iter.marker->format) |
| 1427 | __trace_mark(0, metadata, |
| 1428 | core_marker_format, |
| 1429 | &call_data, |
| 1430 | "channel %s name %s format %s", |
| 1431 | channel, |
| 1432 | iter.marker->name, |
| 1433 | iter.marker->format); |
| 1434 | } |
| 1435 | marker_iter_stop(&iter); |
| 1436 | } |
| 1437 | //ust// EXPORT_SYMBOL_GPL(ltt_dump_marker_state); |
| 1438 | |
| 1439 | |
| 1440 | static LIST_HEAD(libs); |
| 1441 | |
| 1442 | /* |
| 1443 | * Returns 0 if current not found. |
| 1444 | * Returns 1 if current found. |
| 1445 | */ |
| 1446 | int lib_get_iter_markers(struct marker_iter *iter) |
| 1447 | { |
| 1448 | struct lib *iter_lib; |
| 1449 | int found = 0; |
| 1450 | |
| 1451 | //ust// mutex_lock(&module_mutex); |
| 1452 | list_for_each_entry(iter_lib, &libs, list) { |
| 1453 | if (iter_lib < iter->lib) |
| 1454 | continue; |
| 1455 | else if (iter_lib > iter->lib) |
| 1456 | iter->marker = NULL; |
| 1457 | found = marker_get_iter_range(&iter->marker, |
| 1458 | iter_lib->markers_start, |
| 1459 | iter_lib->markers_start + iter_lib->markers_count); |
| 1460 | if (found) { |
| 1461 | iter->lib = iter_lib; |
| 1462 | break; |
| 1463 | } |
| 1464 | } |
| 1465 | //ust// mutex_unlock(&module_mutex); |
| 1466 | return found; |
| 1467 | } |
| 1468 | |
| 1469 | void lib_update_markers(void) |
| 1470 | { |
| 1471 | struct lib *lib; |
| 1472 | |
| 1473 | //ust// mutex_lock(&module_mutex); |
| 1474 | list_for_each_entry(lib, &libs, list) |
| 1475 | marker_update_probe_range(lib->markers_start, |
| 1476 | lib->markers_start + lib->markers_count); |
| 1477 | //ust// mutex_unlock(&module_mutex); |
| 1478 | } |
| 1479 | |
| 1480 | static void (*new_marker_cb)(struct marker *) = NULL; |
| 1481 | |
| 1482 | void marker_set_new_marker_cb(void (*cb)(struct marker *)) |
| 1483 | { |
| 1484 | new_marker_cb = cb; |
| 1485 | } |
| 1486 | |
| 1487 | static void new_markers(struct marker *start, struct marker *end) |
| 1488 | { |
| 1489 | if(new_marker_cb) { |
| 1490 | struct marker *m; |
| 1491 | for(m=start; m < end; m++) { |
| 1492 | new_marker_cb(m); |
| 1493 | } |
| 1494 | } |
| 1495 | } |
| 1496 | |
| 1497 | int marker_register_lib(struct marker *markers_start, int markers_count) |
| 1498 | { |
| 1499 | struct lib *pl; |
| 1500 | |
| 1501 | pl = (struct lib *) malloc(sizeof(struct lib)); |
| 1502 | |
| 1503 | pl->markers_start = markers_start; |
| 1504 | pl->markers_count = markers_count; |
| 1505 | |
| 1506 | /* FIXME: maybe protect this with its own mutex? */ |
| 1507 | lock_markers(); |
| 1508 | list_add(&pl->list, &libs); |
| 1509 | unlock_markers(); |
| 1510 | |
| 1511 | new_markers(markers_start, markers_start + markers_count); |
| 1512 | |
| 1513 | /* FIXME: update just the loaded lib */ |
| 1514 | lib_update_markers(); |
| 1515 | |
| 1516 | DBG("just registered a markers section from %p and having %d markers", markers_start, markers_count); |
| 1517 | |
| 1518 | return 0; |
| 1519 | } |
| 1520 | |
| 1521 | int marker_unregister_lib(struct marker *markers_start, int markers_count) |
| 1522 | { |
| 1523 | /*FIXME: implement; but before implementing, marker_register_lib must |
| 1524 | have appropriate locking. */ |
| 1525 | |
| 1526 | return 0; |
| 1527 | } |
| 1528 | |
| 1529 | static int initialized = 0; |
| 1530 | |
| 1531 | void __attribute__((constructor)) init_markers(void) |
| 1532 | { |
| 1533 | if(!initialized) { |
| 1534 | marker_register_lib(__start___markers, (((long)__stop___markers)-((long)__start___markers))/sizeof(struct marker)); |
| 1535 | printf("markers_start: %p, markers_stop: %p\n", __start___markers, __stop___markers); |
| 1536 | initialized = 1; |
| 1537 | } |
| 1538 | } |