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f99be407 PMF |
1 | /* |
2 | * Copyright (C) 2008 Mathieu Desnoyers | |
1f8b0dff | 3 | * Copyright (C) 2009 Pierre-Marc Fournier |
f99be407 | 4 | * |
34e4b7db PMF |
5 | * This library is free software; you can redistribute it and/or |
6 | * modify it under the terms of the GNU Lesser General Public | |
7 | * License as published by the Free Software Foundation; either | |
8 | * version 2.1 of the License, or (at your option) any later version. | |
f99be407 | 9 | * |
34e4b7db | 10 | * This library is distributed in the hope that it will be useful, |
f99be407 | 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
34e4b7db PMF |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | * Lesser General Public License for more details. | |
f99be407 | 14 | * |
34e4b7db PMF |
15 | * You should have received a copy of the GNU Lesser General Public |
16 | * License along with this library; if not, write to the Free Software | |
17 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
1f8b0dff PMF |
18 | * |
19 | * Ported to userspace by Pierre-Marc Fournier. | |
f99be407 | 20 | */ |
1f8b0dff | 21 | |
474d745f | 22 | #include <errno.h> |
93d0f2ea | 23 | #include <ust/tracepoint.h> |
518d7abb PMF |
24 | #include <ust/core.h> |
25 | #include <ust/kcompat/kcompat.h> | |
474d745f | 26 | #include "usterr.h" |
769d0157 JB |
27 | |
28 | #define _LGPL_SOURCE | |
b7ea1a1c | 29 | #include <urcu-bp.h> |
474d745f PMF |
30 | |
31 | //extern struct tracepoint __start___tracepoints[] __attribute__((visibility("hidden"))); | |
32 | //extern struct tracepoint __stop___tracepoints[] __attribute__((visibility("hidden"))); | |
f99be407 PMF |
33 | |
34 | /* Set to 1 to enable tracepoint debug output */ | |
35 | static const int tracepoint_debug; | |
36 | ||
474d745f PMF |
37 | /* libraries that contain tracepoints (struct tracepoint_lib) */ |
38 | static LIST_HEAD(libs); | |
39 | ||
f99be407 PMF |
40 | /* |
41 | * tracepoints_mutex nests inside module_mutex. Tracepoints mutex protects the | |
42 | * builtin and module tracepoints and the hash table. | |
43 | */ | |
44 | static DEFINE_MUTEX(tracepoints_mutex); | |
45 | ||
46 | /* | |
47 | * Tracepoint hash table, containing the active tracepoints. | |
48 | * Protected by tracepoints_mutex. | |
49 | */ | |
50 | #define TRACEPOINT_HASH_BITS 6 | |
51 | #define TRACEPOINT_TABLE_SIZE (1 << TRACEPOINT_HASH_BITS) | |
52 | static struct hlist_head tracepoint_table[TRACEPOINT_TABLE_SIZE]; | |
53 | ||
54 | /* | |
55 | * Note about RCU : | |
56 | * It is used to to delay the free of multiple probes array until a quiescent | |
57 | * state is reached. | |
58 | * Tracepoint entries modifications are protected by the tracepoints_mutex. | |
59 | */ | |
60 | struct tracepoint_entry { | |
61 | struct hlist_node hlist; | |
9dec086e | 62 | struct probe *probes; |
f99be407 PMF |
63 | int refcount; /* Number of times armed. 0 if disarmed. */ |
64 | char name[0]; | |
65 | }; | |
66 | ||
67 | struct tp_probes { | |
68 | union { | |
474d745f | 69 | //ust// struct rcu_head rcu; |
f99be407 PMF |
70 | struct list_head list; |
71 | } u; | |
9dec086e | 72 | struct probe probes[0]; |
f99be407 PMF |
73 | }; |
74 | ||
75 | static inline void *allocate_probes(int count) | |
76 | { | |
86699c20 | 77 | struct tp_probes *p = zmalloc(count * sizeof(struct probe) |
909bc43f | 78 | + sizeof(struct tp_probes)); |
f99be407 PMF |
79 | return p == NULL ? NULL : p->probes; |
80 | } | |
81 | ||
474d745f PMF |
82 | //ust// static void rcu_free_old_probes(struct rcu_head *head) |
83 | //ust// { | |
84 | //ust// kfree(container_of(head, struct tp_probes, u.rcu)); | |
85 | //ust// } | |
f99be407 PMF |
86 | |
87 | static inline void release_probes(void *old) | |
88 | { | |
89 | if (old) { | |
1e4b909b | 90 | struct tp_probes *tp_probes = _ust_container_of(old, |
f99be407 | 91 | struct tp_probes, probes[0]); |
474d745f PMF |
92 | //ust// call_rcu_sched(&tp_probes->u.rcu, rcu_free_old_probes); |
93 | synchronize_rcu(); | |
909bc43f | 94 | free(tp_probes); |
f99be407 PMF |
95 | } |
96 | } | |
97 | ||
98 | static void debug_print_probes(struct tracepoint_entry *entry) | |
99 | { | |
100 | int i; | |
101 | ||
9dec086e | 102 | if (!tracepoint_debug || !entry->probes) |
f99be407 PMF |
103 | return; |
104 | ||
9dec086e NC |
105 | for (i = 0; entry->probes[i].func; i++) |
106 | DBG("Probe %d : %p", i, entry->probes[i].func); | |
f99be407 PMF |
107 | } |
108 | ||
109 | static void * | |
9dec086e NC |
110 | tracepoint_entry_add_probe(struct tracepoint_entry *entry, |
111 | void *probe, void *data) | |
f99be407 PMF |
112 | { |
113 | int nr_probes = 0; | |
9dec086e | 114 | struct probe *old, *new; |
f99be407 PMF |
115 | |
116 | WARN_ON(!probe); | |
117 | ||
118 | debug_print_probes(entry); | |
9dec086e | 119 | old = entry->probes; |
f99be407 PMF |
120 | if (old) { |
121 | /* (N -> N+1), (N != 0, 1) probes */ | |
9dec086e NC |
122 | for (nr_probes = 0; old[nr_probes].func; nr_probes++) |
123 | if (old[nr_probes].func == probe && | |
124 | old[nr_probes].data == data) | |
f99be407 PMF |
125 | return ERR_PTR(-EEXIST); |
126 | } | |
127 | /* + 2 : one for new probe, one for NULL func */ | |
128 | new = allocate_probes(nr_probes + 2); | |
129 | if (new == NULL) | |
130 | return ERR_PTR(-ENOMEM); | |
131 | if (old) | |
9dec086e NC |
132 | memcpy(new, old, nr_probes * sizeof(struct probe)); |
133 | new[nr_probes].func = probe; | |
134 | new[nr_probes].data = data; | |
135 | new[nr_probes + 1].func = NULL; | |
f99be407 | 136 | entry->refcount = nr_probes + 1; |
9dec086e | 137 | entry->probes = new; |
f99be407 PMF |
138 | debug_print_probes(entry); |
139 | return old; | |
140 | } | |
141 | ||
142 | static void * | |
9dec086e NC |
143 | tracepoint_entry_remove_probe(struct tracepoint_entry *entry, void *probe, |
144 | void *data) | |
f99be407 PMF |
145 | { |
146 | int nr_probes = 0, nr_del = 0, i; | |
9dec086e | 147 | struct probe *old, *new; |
f99be407 | 148 | |
9dec086e | 149 | old = entry->probes; |
f99be407 PMF |
150 | |
151 | if (!old) | |
152 | return ERR_PTR(-ENOENT); | |
153 | ||
154 | debug_print_probes(entry); | |
155 | /* (N -> M), (N > 1, M >= 0) probes */ | |
9dec086e | 156 | for (nr_probes = 0; old[nr_probes].func; nr_probes++) { |
c66428ac DG |
157 | if (!probe || |
158 | (old[nr_probes].func == probe && | |
9dec086e | 159 | old[nr_probes].data == data)) |
f99be407 PMF |
160 | nr_del++; |
161 | } | |
162 | ||
163 | if (nr_probes - nr_del == 0) { | |
164 | /* N -> 0, (N > 1) */ | |
9dec086e | 165 | entry->probes = NULL; |
f99be407 PMF |
166 | entry->refcount = 0; |
167 | debug_print_probes(entry); | |
168 | return old; | |
169 | } else { | |
170 | int j = 0; | |
171 | /* N -> M, (N > 1, M > 0) */ | |
172 | /* + 1 for NULL */ | |
173 | new = allocate_probes(nr_probes - nr_del + 1); | |
174 | if (new == NULL) | |
175 | return ERR_PTR(-ENOMEM); | |
9dec086e NC |
176 | for (i = 0; old[i].func; i++) |
177 | if (probe && | |
178 | (old[i].func != probe || old[i].data != data)) | |
f99be407 | 179 | new[j++] = old[i]; |
9dec086e | 180 | new[nr_probes - nr_del].func = NULL; |
f99be407 | 181 | entry->refcount = nr_probes - nr_del; |
9dec086e | 182 | entry->probes = new; |
f99be407 PMF |
183 | } |
184 | debug_print_probes(entry); | |
185 | return old; | |
186 | } | |
187 | ||
188 | /* | |
189 | * Get tracepoint if the tracepoint is present in the tracepoint hash table. | |
190 | * Must be called with tracepoints_mutex held. | |
191 | * Returns NULL if not present. | |
192 | */ | |
193 | static struct tracepoint_entry *get_tracepoint(const char *name) | |
194 | { | |
195 | struct hlist_head *head; | |
196 | struct hlist_node *node; | |
197 | struct tracepoint_entry *e; | |
198 | u32 hash = jhash(name, strlen(name), 0); | |
199 | ||
200 | head = &tracepoint_table[hash & (TRACEPOINT_TABLE_SIZE - 1)]; | |
201 | hlist_for_each_entry(e, node, head, hlist) { | |
202 | if (!strcmp(name, e->name)) | |
203 | return e; | |
204 | } | |
205 | return NULL; | |
206 | } | |
207 | ||
208 | /* | |
209 | * Add the tracepoint to the tracepoint hash table. Must be called with | |
210 | * tracepoints_mutex held. | |
211 | */ | |
212 | static struct tracepoint_entry *add_tracepoint(const char *name) | |
213 | { | |
214 | struct hlist_head *head; | |
215 | struct hlist_node *node; | |
216 | struct tracepoint_entry *e; | |
217 | size_t name_len = strlen(name) + 1; | |
218 | u32 hash = jhash(name, name_len-1, 0); | |
219 | ||
220 | head = &tracepoint_table[hash & (TRACEPOINT_TABLE_SIZE - 1)]; | |
221 | hlist_for_each_entry(e, node, head, hlist) { | |
222 | if (!strcmp(name, e->name)) { | |
c1f20530 | 223 | DBG("tracepoint %s busy", name); |
f99be407 PMF |
224 | return ERR_PTR(-EEXIST); /* Already there */ |
225 | } | |
226 | } | |
227 | /* | |
1dba3e6c | 228 | * Using zmalloc here to allocate a variable length element. Could |
f99be407 PMF |
229 | * cause some memory fragmentation if overused. |
230 | */ | |
1dba3e6c | 231 | e = zmalloc(sizeof(struct tracepoint_entry) + name_len); |
f99be407 PMF |
232 | if (!e) |
233 | return ERR_PTR(-ENOMEM); | |
234 | memcpy(&e->name[0], name, name_len); | |
9dec086e | 235 | e->probes = NULL; |
f99be407 PMF |
236 | e->refcount = 0; |
237 | hlist_add_head(&e->hlist, head); | |
238 | return e; | |
239 | } | |
240 | ||
241 | /* | |
242 | * Remove the tracepoint from the tracepoint hash table. Must be called with | |
243 | * mutex_lock held. | |
244 | */ | |
245 | static inline void remove_tracepoint(struct tracepoint_entry *e) | |
246 | { | |
247 | hlist_del(&e->hlist); | |
909bc43f | 248 | free(e); |
f99be407 PMF |
249 | } |
250 | ||
251 | /* | |
252 | * Sets the probe callback corresponding to one tracepoint. | |
253 | */ | |
254 | static void set_tracepoint(struct tracepoint_entry **entry, | |
255 | struct tracepoint *elem, int active) | |
256 | { | |
257 | WARN_ON(strcmp((*entry)->name, elem->name) != 0); | |
258 | ||
259 | /* | |
260 | * rcu_assign_pointer has a smp_wmb() which makes sure that the new | |
261 | * probe callbacks array is consistent before setting a pointer to it. | |
262 | * This array is referenced by __DO_TRACE from | |
263 | * include/linux/tracepoints.h. A matching smp_read_barrier_depends() | |
264 | * is used. | |
265 | */ | |
9dec086e | 266 | rcu_assign_pointer(elem->probes, (*entry)->probes); |
f99be407 PMF |
267 | elem->state__imv = active; |
268 | } | |
269 | ||
270 | /* | |
271 | * Disable a tracepoint and its probe callback. | |
272 | * Note: only waiting an RCU period after setting elem->call to the empty | |
273 | * function insures that the original callback is not used anymore. This insured | |
274 | * by preempt_disable around the call site. | |
275 | */ | |
276 | static void disable_tracepoint(struct tracepoint *elem) | |
277 | { | |
278 | elem->state__imv = 0; | |
9dec086e | 279 | rcu_assign_pointer(elem->probes, NULL); |
f99be407 PMF |
280 | } |
281 | ||
282 | /** | |
283 | * tracepoint_update_probe_range - Update a probe range | |
284 | * @begin: beginning of the range | |
285 | * @end: end of the range | |
286 | * | |
287 | * Updates the probe callback corresponding to a range of tracepoints. | |
288 | */ | |
289 | void tracepoint_update_probe_range(struct tracepoint *begin, | |
9dec086e | 290 | struct tracepoint *end) |
f99be407 PMF |
291 | { |
292 | struct tracepoint *iter; | |
293 | struct tracepoint_entry *mark_entry; | |
294 | ||
f7b16408 | 295 | pthread_mutex_lock(&tracepoints_mutex); |
f99be407 | 296 | for (iter = begin; iter < end; iter++) { |
9dec086e NC |
297 | if (!iter->name) { |
298 | disable_tracepoint(iter); | |
299 | continue; | |
300 | } | |
f99be407 PMF |
301 | mark_entry = get_tracepoint(iter->name); |
302 | if (mark_entry) { | |
303 | set_tracepoint(&mark_entry, iter, | |
304 | !!mark_entry->refcount); | |
305 | } else { | |
306 | disable_tracepoint(iter); | |
307 | } | |
308 | } | |
f7b16408 | 309 | pthread_mutex_unlock(&tracepoints_mutex); |
f99be407 PMF |
310 | } |
311 | ||
772030fe PMF |
312 | static void lib_update_tracepoints(void) |
313 | { | |
314 | struct tracepoint_lib *lib; | |
315 | ||
f7b16408 | 316 | //ust// pthread_mutex_lock(&module_mutex); |
772030fe PMF |
317 | list_for_each_entry(lib, &libs, list) |
318 | tracepoint_update_probe_range(lib->tracepoints_start, | |
319 | lib->tracepoints_start + lib->tracepoints_count); | |
f7b16408 | 320 | //ust// pthread_mutex_unlock(&module_mutex); |
772030fe PMF |
321 | } |
322 | ||
f99be407 PMF |
323 | /* |
324 | * Update probes, removing the faulty probes. | |
325 | */ | |
326 | static void tracepoint_update_probes(void) | |
327 | { | |
328 | /* Core kernel tracepoints */ | |
474d745f PMF |
329 | //ust// tracepoint_update_probe_range(__start___tracepoints, |
330 | //ust// __stop___tracepoints); | |
f99be407 | 331 | /* tracepoints in modules. */ |
474d745f | 332 | lib_update_tracepoints(); |
f99be407 PMF |
333 | /* Update immediate values */ |
334 | core_imv_update(); | |
474d745f | 335 | //ust// module_imv_update(); |
f99be407 PMF |
336 | } |
337 | ||
9dec086e NC |
338 | static struct probe * |
339 | tracepoint_add_probe(const char *name, void *probe, void *data) | |
f99be407 PMF |
340 | { |
341 | struct tracepoint_entry *entry; | |
9dec086e | 342 | struct probe *old; |
f99be407 PMF |
343 | |
344 | entry = get_tracepoint(name); | |
345 | if (!entry) { | |
346 | entry = add_tracepoint(name); | |
347 | if (IS_ERR(entry)) | |
9dec086e | 348 | return (struct probe *)entry; |
f99be407 | 349 | } |
9dec086e | 350 | old = tracepoint_entry_add_probe(entry, probe, data); |
f99be407 PMF |
351 | if (IS_ERR(old) && !entry->refcount) |
352 | remove_tracepoint(entry); | |
353 | return old; | |
354 | } | |
355 | ||
356 | /** | |
357 | * tracepoint_probe_register - Connect a probe to a tracepoint | |
358 | * @name: tracepoint name | |
359 | * @probe: probe handler | |
360 | * | |
361 | * Returns 0 if ok, error value on error. | |
362 | * The probe address must at least be aligned on the architecture pointer size. | |
363 | */ | |
9dec086e | 364 | int tracepoint_probe_register(const char *name, void *probe, void *data) |
f99be407 PMF |
365 | { |
366 | void *old; | |
367 | ||
f7b16408 | 368 | pthread_mutex_lock(&tracepoints_mutex); |
9dec086e | 369 | old = tracepoint_add_probe(name, probe, data); |
f7b16408 | 370 | pthread_mutex_unlock(&tracepoints_mutex); |
f99be407 PMF |
371 | if (IS_ERR(old)) |
372 | return PTR_ERR(old); | |
373 | ||
374 | tracepoint_update_probes(); /* may update entry */ | |
375 | release_probes(old); | |
376 | return 0; | |
377 | } | |
474d745f | 378 | //ust// EXPORT_SYMBOL_GPL(tracepoint_probe_register); |
f99be407 | 379 | |
9dec086e | 380 | static void *tracepoint_remove_probe(const char *name, void *probe, void *data) |
f99be407 PMF |
381 | { |
382 | struct tracepoint_entry *entry; | |
383 | void *old; | |
384 | ||
385 | entry = get_tracepoint(name); | |
386 | if (!entry) | |
387 | return ERR_PTR(-ENOENT); | |
9dec086e | 388 | old = tracepoint_entry_remove_probe(entry, probe, data); |
f99be407 PMF |
389 | if (IS_ERR(old)) |
390 | return old; | |
391 | if (!entry->refcount) | |
392 | remove_tracepoint(entry); | |
393 | return old; | |
394 | } | |
395 | ||
396 | /** | |
397 | * tracepoint_probe_unregister - Disconnect a probe from a tracepoint | |
398 | * @name: tracepoint name | |
399 | * @probe: probe function pointer | |
9dec086e | 400 | * @probe: probe data pointer |
f99be407 PMF |
401 | * |
402 | * We do not need to call a synchronize_sched to make sure the probes have | |
403 | * finished running before doing a module unload, because the module unload | |
404 | * itself uses stop_machine(), which insures that every preempt disabled section | |
405 | * have finished. | |
406 | */ | |
9dec086e | 407 | int tracepoint_probe_unregister(const char *name, void *probe, void *data) |
f99be407 PMF |
408 | { |
409 | void *old; | |
410 | ||
f7b16408 | 411 | pthread_mutex_lock(&tracepoints_mutex); |
9dec086e | 412 | old = tracepoint_remove_probe(name, probe, data); |
f7b16408 | 413 | pthread_mutex_unlock(&tracepoints_mutex); |
f99be407 PMF |
414 | if (IS_ERR(old)) |
415 | return PTR_ERR(old); | |
416 | ||
417 | tracepoint_update_probes(); /* may update entry */ | |
418 | release_probes(old); | |
419 | return 0; | |
420 | } | |
474d745f | 421 | //ust// EXPORT_SYMBOL_GPL(tracepoint_probe_unregister); |
f99be407 PMF |
422 | |
423 | static LIST_HEAD(old_probes); | |
424 | static int need_update; | |
425 | ||
426 | static void tracepoint_add_old_probes(void *old) | |
427 | { | |
428 | need_update = 1; | |
429 | if (old) { | |
1e4b909b | 430 | struct tp_probes *tp_probes = _ust_container_of(old, |
f99be407 PMF |
431 | struct tp_probes, probes[0]); |
432 | list_add(&tp_probes->u.list, &old_probes); | |
433 | } | |
434 | } | |
435 | ||
436 | /** | |
437 | * tracepoint_probe_register_noupdate - register a probe but not connect | |
438 | * @name: tracepoint name | |
439 | * @probe: probe handler | |
440 | * | |
441 | * caller must call tracepoint_probe_update_all() | |
442 | */ | |
9dec086e NC |
443 | int tracepoint_probe_register_noupdate(const char *name, void *probe, |
444 | void *data) | |
f99be407 PMF |
445 | { |
446 | void *old; | |
447 | ||
f7b16408 | 448 | pthread_mutex_lock(&tracepoints_mutex); |
9dec086e | 449 | old = tracepoint_add_probe(name, probe, data); |
f99be407 | 450 | if (IS_ERR(old)) { |
f7b16408 | 451 | pthread_mutex_unlock(&tracepoints_mutex); |
f99be407 PMF |
452 | return PTR_ERR(old); |
453 | } | |
454 | tracepoint_add_old_probes(old); | |
f7b16408 | 455 | pthread_mutex_unlock(&tracepoints_mutex); |
f99be407 PMF |
456 | return 0; |
457 | } | |
474d745f | 458 | //ust// EXPORT_SYMBOL_GPL(tracepoint_probe_register_noupdate); |
f99be407 PMF |
459 | |
460 | /** | |
461 | * tracepoint_probe_unregister_noupdate - remove a probe but not disconnect | |
462 | * @name: tracepoint name | |
463 | * @probe: probe function pointer | |
464 | * | |
465 | * caller must call tracepoint_probe_update_all() | |
466 | */ | |
9dec086e NC |
467 | int tracepoint_probe_unregister_noupdate(const char *name, void *probe, |
468 | void *data) | |
f99be407 PMF |
469 | { |
470 | void *old; | |
471 | ||
f7b16408 | 472 | pthread_mutex_lock(&tracepoints_mutex); |
9dec086e | 473 | old = tracepoint_remove_probe(name, probe, data); |
f99be407 | 474 | if (IS_ERR(old)) { |
f7b16408 | 475 | pthread_mutex_unlock(&tracepoints_mutex); |
f99be407 PMF |
476 | return PTR_ERR(old); |
477 | } | |
478 | tracepoint_add_old_probes(old); | |
f7b16408 | 479 | pthread_mutex_unlock(&tracepoints_mutex); |
f99be407 PMF |
480 | return 0; |
481 | } | |
474d745f | 482 | //ust// EXPORT_SYMBOL_GPL(tracepoint_probe_unregister_noupdate); |
f99be407 PMF |
483 | |
484 | /** | |
485 | * tracepoint_probe_update_all - update tracepoints | |
486 | */ | |
487 | void tracepoint_probe_update_all(void) | |
488 | { | |
489 | LIST_HEAD(release_probes); | |
490 | struct tp_probes *pos, *next; | |
491 | ||
f7b16408 | 492 | pthread_mutex_lock(&tracepoints_mutex); |
f99be407 | 493 | if (!need_update) { |
f7b16408 | 494 | pthread_mutex_unlock(&tracepoints_mutex); |
f99be407 PMF |
495 | return; |
496 | } | |
497 | if (!list_empty(&old_probes)) | |
498 | list_replace_init(&old_probes, &release_probes); | |
499 | need_update = 0; | |
f7b16408 | 500 | pthread_mutex_unlock(&tracepoints_mutex); |
f99be407 PMF |
501 | |
502 | tracepoint_update_probes(); | |
503 | list_for_each_entry_safe(pos, next, &release_probes, u.list) { | |
504 | list_del(&pos->u.list); | |
474d745f PMF |
505 | //ust// call_rcu_sched(&pos->u.rcu, rcu_free_old_probes); |
506 | synchronize_rcu(); | |
909bc43f | 507 | free(pos); |
f99be407 PMF |
508 | } |
509 | } | |
474d745f | 510 | //ust// EXPORT_SYMBOL_GPL(tracepoint_probe_update_all); |
f99be407 | 511 | |
772030fe PMF |
512 | /* |
513 | * Returns 0 if current not found. | |
514 | * Returns 1 if current found. | |
515 | */ | |
516 | int lib_get_iter_tracepoints(struct tracepoint_iter *iter) | |
517 | { | |
518 | struct tracepoint_lib *iter_lib; | |
519 | int found = 0; | |
520 | ||
f7b16408 | 521 | //ust// pthread_mutex_lock(&module_mutex); |
772030fe PMF |
522 | list_for_each_entry(iter_lib, &libs, list) { |
523 | if (iter_lib < iter->lib) | |
524 | continue; | |
525 | else if (iter_lib > iter->lib) | |
526 | iter->tracepoint = NULL; | |
527 | found = tracepoint_get_iter_range(&iter->tracepoint, | |
528 | iter_lib->tracepoints_start, | |
529 | iter_lib->tracepoints_start + iter_lib->tracepoints_count); | |
530 | if (found) { | |
531 | iter->lib = iter_lib; | |
532 | break; | |
533 | } | |
534 | } | |
f7b16408 | 535 | //ust// pthread_mutex_unlock(&module_mutex); |
772030fe PMF |
536 | return found; |
537 | } | |
538 | ||
f99be407 PMF |
539 | /** |
540 | * tracepoint_get_iter_range - Get a next tracepoint iterator given a range. | |
541 | * @tracepoint: current tracepoints (in), next tracepoint (out) | |
542 | * @begin: beginning of the range | |
543 | * @end: end of the range | |
544 | * | |
545 | * Returns whether a next tracepoint has been found (1) or not (0). | |
546 | * Will return the first tracepoint in the range if the input tracepoint is | |
547 | * NULL. | |
548 | */ | |
549 | int tracepoint_get_iter_range(struct tracepoint **tracepoint, | |
550 | struct tracepoint *begin, struct tracepoint *end) | |
551 | { | |
552 | if (!*tracepoint && begin != end) { | |
553 | *tracepoint = begin; | |
554 | return 1; | |
555 | } | |
556 | if (*tracepoint >= begin && *tracepoint < end) | |
557 | return 1; | |
558 | return 0; | |
559 | } | |
474d745f | 560 | //ust// EXPORT_SYMBOL_GPL(tracepoint_get_iter_range); |
f99be407 PMF |
561 | |
562 | static void tracepoint_get_iter(struct tracepoint_iter *iter) | |
563 | { | |
564 | int found = 0; | |
565 | ||
474d745f PMF |
566 | //ust// /* Core kernel tracepoints */ |
567 | //ust// if (!iter->module) { | |
568 | //ust// found = tracepoint_get_iter_range(&iter->tracepoint, | |
569 | //ust// __start___tracepoints, __stop___tracepoints); | |
570 | //ust// if (found) | |
571 | //ust// goto end; | |
572 | //ust// } | |
573 | /* tracepoints in libs. */ | |
574 | found = lib_get_iter_tracepoints(iter); | |
772030fe | 575 | //ust// end: |
f99be407 PMF |
576 | if (!found) |
577 | tracepoint_iter_reset(iter); | |
578 | } | |
579 | ||
580 | void tracepoint_iter_start(struct tracepoint_iter *iter) | |
581 | { | |
582 | tracepoint_get_iter(iter); | |
583 | } | |
474d745f | 584 | //ust// EXPORT_SYMBOL_GPL(tracepoint_iter_start); |
f99be407 PMF |
585 | |
586 | void tracepoint_iter_next(struct tracepoint_iter *iter) | |
587 | { | |
588 | iter->tracepoint++; | |
589 | /* | |
590 | * iter->tracepoint may be invalid because we blindly incremented it. | |
591 | * Make sure it is valid by marshalling on the tracepoints, getting the | |
592 | * tracepoints from following modules if necessary. | |
593 | */ | |
594 | tracepoint_get_iter(iter); | |
595 | } | |
474d745f | 596 | //ust// EXPORT_SYMBOL_GPL(tracepoint_iter_next); |
f99be407 PMF |
597 | |
598 | void tracepoint_iter_stop(struct tracepoint_iter *iter) | |
599 | { | |
600 | } | |
474d745f | 601 | //ust// EXPORT_SYMBOL_GPL(tracepoint_iter_stop); |
f99be407 PMF |
602 | |
603 | void tracepoint_iter_reset(struct tracepoint_iter *iter) | |
604 | { | |
474d745f | 605 | //ust// iter->module = NULL; |
f99be407 PMF |
606 | iter->tracepoint = NULL; |
607 | } | |
474d745f PMF |
608 | //ust// EXPORT_SYMBOL_GPL(tracepoint_iter_reset); |
609 | ||
610 | //ust// #ifdef CONFIG_MODULES | |
611 | ||
612 | //ust// int tracepoint_module_notify(struct notifier_block *self, | |
613 | //ust// unsigned long val, void *data) | |
614 | //ust// { | |
615 | //ust// struct module *mod = data; | |
616 | //ust// | |
617 | //ust// switch (val) { | |
618 | //ust// case MODULE_STATE_COMING: | |
619 | //ust// tracepoint_update_probe_range(mod->tracepoints, | |
620 | //ust// mod->tracepoints + mod->num_tracepoints); | |
621 | //ust// break; | |
622 | //ust// case MODULE_STATE_GOING: | |
623 | //ust// tracepoint_update_probe_range(mod->tracepoints, | |
624 | //ust// mod->tracepoints + mod->num_tracepoints); | |
625 | //ust// break; | |
626 | //ust// } | |
627 | //ust// return 0; | |
628 | //ust// } | |
629 | ||
630 | //ust// struct notifier_block tracepoint_module_nb = { | |
631 | //ust// .notifier_call = tracepoint_module_notify, | |
632 | //ust// .priority = 0, | |
633 | //ust// }; | |
634 | ||
635 | //ust// static int init_tracepoints(void) | |
636 | //ust// { | |
637 | //ust// return register_module_notifier(&tracepoint_module_nb); | |
638 | //ust// } | |
639 | //ust// __initcall(init_tracepoints); | |
640 | ||
641 | //ust// #endif /* CONFIG_MODULES */ | |
f99be407 | 642 | |
474d745f PMF |
643 | static void (*new_tracepoint_cb)(struct tracepoint *) = NULL; |
644 | ||
645 | void tracepoint_set_new_tracepoint_cb(void (*cb)(struct tracepoint *)) | |
646 | { | |
647 | new_tracepoint_cb = cb; | |
648 | } | |
f99be407 | 649 | |
474d745f | 650 | static void new_tracepoints(struct tracepoint *start, struct tracepoint *end) |
f99be407 | 651 | { |
474d745f PMF |
652 | if(new_tracepoint_cb) { |
653 | struct tracepoint *t; | |
654 | for(t=start; t < end; t++) { | |
655 | new_tracepoint_cb(t); | |
656 | } | |
657 | } | |
f99be407 | 658 | } |
f99be407 | 659 | |
474d745f PMF |
660 | int tracepoint_register_lib(struct tracepoint *tracepoints_start, int tracepoints_count) |
661 | { | |
662 | struct tracepoint_lib *pl; | |
663 | ||
1dba3e6c | 664 | pl = (struct tracepoint_lib *) zmalloc(sizeof(struct tracepoint_lib)); |
474d745f PMF |
665 | |
666 | pl->tracepoints_start = tracepoints_start; | |
667 | pl->tracepoints_count = tracepoints_count; | |
668 | ||
669 | /* FIXME: maybe protect this with its own mutex? */ | |
f7b16408 | 670 | pthread_mutex_lock(&tracepoints_mutex); |
474d745f | 671 | list_add(&pl->list, &libs); |
f7b16408 | 672 | pthread_mutex_unlock(&tracepoints_mutex); |
474d745f PMF |
673 | |
674 | new_tracepoints(tracepoints_start, tracepoints_start + tracepoints_count); | |
675 | ||
676 | /* FIXME: update just the loaded lib */ | |
677 | lib_update_tracepoints(); | |
678 | ||
679 | DBG("just registered a tracepoints section from %p and having %d tracepoints", tracepoints_start, tracepoints_count); | |
9dec086e | 680 | |
474d745f PMF |
681 | return 0; |
682 | } | |
683 | ||
24b6668c | 684 | int tracepoint_unregister_lib(struct tracepoint *tracepoints_start) |
474d745f | 685 | { |
24b6668c PMF |
686 | struct tracepoint_lib *lib; |
687 | ||
f7b16408 | 688 | pthread_mutex_lock(&tracepoints_mutex); |
24b6668c PMF |
689 | |
690 | list_for_each_entry(lib, &libs, list) { | |
691 | if(lib->tracepoints_start == tracepoints_start) { | |
692 | struct tracepoint_lib *lib2free = lib; | |
693 | list_del(&lib->list); | |
694 | free(lib2free); | |
695 | break; | |
696 | } | |
697 | } | |
698 | ||
f7b16408 | 699 | pthread_mutex_unlock(&tracepoints_mutex); |
474d745f PMF |
700 | |
701 | return 0; | |
702 | } |