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68c1021b PMF |
1 | /* |
2 | * Copyright (C) 2007 Mathieu Desnoyers | |
3 | * | |
34e4b7db PMF |
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. | |
68c1021b | 8 | * |
34e4b7db | 9 | * This library is distributed in the hope that it will be useful, |
68c1021b | 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
34e4b7db PMF |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
12 | * Lesser General Public License for more details. | |
68c1021b | 13 | * |
34e4b7db PMF |
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 | |
68c1021b | 17 | */ |
59b161cd | 18 | |
909bc43f PMF |
19 | #include <stdlib.h> |
20 | #include <errno.h> | |
769d0157 | 21 | #define _LGPL_SOURCE |
b7ea1a1c | 22 | #include <urcu-bp.h> |
769d0157 | 23 | |
fbca6b62 | 24 | #include <ust/kernelcompat.h> |
93d0f2ea | 25 | #include <ust/marker.h> |
909bc43f | 26 | |
59b161cd PMF |
27 | #include "usterr.h" |
28 | #include "channels.h" | |
29 | #include "tracercore.h" | |
c93858f1 | 30 | #include "tracer.h" |
68c1021b | 31 | |
636ca5d6 PMF |
32 | __thread long ust_reg_stack[500]; |
33 | volatile __thread long *ust_reg_stack_ptr = (long *) 0; | |
34 | ||
c463904d PMF |
35 | extern struct marker __start___markers[] __attribute__((visibility("hidden"))); |
36 | extern struct marker __stop___markers[] __attribute__((visibility("hidden"))); | |
defa46a7 | 37 | |
68c1021b PMF |
38 | /* Set to 1 to enable marker debug output */ |
39 | static const int marker_debug; | |
40 | ||
41 | /* | |
42 | * markers_mutex nests inside module_mutex. Markers mutex protects the builtin | |
43 | * and module markers and the hash table. | |
44 | */ | |
45 | static DEFINE_MUTEX(markers_mutex); | |
46 | ||
772030fe PMF |
47 | static LIST_HEAD(libs); |
48 | ||
49 | ||
68c1021b PMF |
50 | void lock_markers(void) |
51 | { | |
52 | mutex_lock(&markers_mutex); | |
53 | } | |
54 | ||
55 | void unlock_markers(void) | |
56 | { | |
57 | mutex_unlock(&markers_mutex); | |
58 | } | |
59 | ||
60 | /* | |
61 | * Marker hash table, containing the active markers. | |
62 | * Protected by module_mutex. | |
63 | */ | |
64 | #define MARKER_HASH_BITS 6 | |
65 | #define MARKER_TABLE_SIZE (1 << MARKER_HASH_BITS) | |
66 | static struct hlist_head marker_table[MARKER_TABLE_SIZE]; | |
67 | ||
68 | /* | |
69 | * Note about RCU : | |
70 | * It is used to make sure every handler has finished using its private data | |
71 | * between two consecutive operation (add or remove) on a given marker. It is | |
72 | * also used to delay the free of multiple probes array until a quiescent state | |
73 | * is reached. | |
74 | * marker entries modifications are protected by the markers_mutex. | |
75 | */ | |
76 | struct marker_entry { | |
77 | struct hlist_node hlist; | |
78 | char *format; | |
79 | char *name; | |
80 | /* Probe wrapper */ | |
75667d04 | 81 | void (*call)(const struct marker *mdata, void *call_private, struct registers *regs, ...); |
68c1021b PMF |
82 | struct marker_probe_closure single; |
83 | struct marker_probe_closure *multi; | |
84 | int refcount; /* Number of times armed. 0 if disarmed. */ | |
85 | struct rcu_head rcu; | |
86 | void *oldptr; | |
87 | int rcu_pending; | |
88 | u16 channel_id; | |
89 | u16 event_id; | |
90 | unsigned char ptype:1; | |
91 | unsigned char format_allocated:1; | |
92 | char channel[0]; /* Contains channel'\0'name'\0'format'\0' */ | |
93 | }; | |
94 | ||
95 | #ifdef CONFIG_MARKERS_USERSPACE | |
96 | static void marker_update_processes(void); | |
97 | #else | |
98 | static void marker_update_processes(void) | |
99 | { | |
100 | } | |
101 | #endif | |
102 | ||
103 | /** | |
104 | * __mark_empty_function - Empty probe callback | |
105 | * @mdata: marker data | |
106 | * @probe_private: probe private data | |
107 | * @call_private: call site private data | |
108 | * @fmt: format string | |
109 | * @...: variable argument list | |
110 | * | |
111 | * Empty callback provided as a probe to the markers. By providing this to a | |
112 | * disabled marker, we make sure the execution flow is always valid even | |
113 | * though the function pointer change and the marker enabling are two distinct | |
114 | * operations that modifies the execution flow of preemptible code. | |
115 | */ | |
116 | notrace void __mark_empty_function(const struct marker *mdata, | |
75667d04 | 117 | void *probe_private, struct registers *regs, void *call_private, const char *fmt, va_list *args) |
68c1021b PMF |
118 | { |
119 | } | |
59b161cd | 120 | //ust// EXPORT_SYMBOL_GPL(__mark_empty_function); |
68c1021b PMF |
121 | |
122 | /* | |
123 | * marker_probe_cb Callback that prepares the variable argument list for probes. | |
124 | * @mdata: pointer of type struct marker | |
125 | * @call_private: caller site private data | |
126 | * @...: Variable argument list. | |
127 | * | |
128 | * Since we do not use "typical" pointer based RCU in the 1 argument case, we | |
129 | * need to put a full smp_rmb() in this branch. This is why we do not use | |
130 | * rcu_dereference() for the pointer read. | |
131 | */ | |
132 | notrace void marker_probe_cb(const struct marker *mdata, | |
75667d04 | 133 | void *call_private, struct registers *regs, ...) |
68c1021b PMF |
134 | { |
135 | va_list args; | |
136 | char ptype; | |
137 | ||
138 | /* | |
139 | * rcu_read_lock_sched does two things : disabling preemption to make | |
140 | * sure the teardown of the callbacks can be done correctly when they | |
141 | * are in modules and they insure RCU read coherency. | |
142 | */ | |
59b161cd | 143 | //ust// rcu_read_lock_sched_notrace(); |
68c1021b PMF |
144 | ptype = mdata->ptype; |
145 | if (likely(!ptype)) { | |
146 | marker_probe_func *func; | |
147 | /* Must read the ptype before ptr. They are not data dependant, | |
148 | * so we put an explicit smp_rmb() here. */ | |
149 | smp_rmb(); | |
150 | func = mdata->single.func; | |
151 | /* Must read the ptr before private data. They are not data | |
152 | * dependant, so we put an explicit smp_rmb() here. */ | |
153 | smp_rmb(); | |
75667d04 PMF |
154 | va_start(args, regs); |
155 | func(mdata, mdata->single.probe_private, regs, call_private, | |
68c1021b PMF |
156 | mdata->format, &args); |
157 | va_end(args); | |
158 | } else { | |
159 | struct marker_probe_closure *multi; | |
160 | int i; | |
161 | /* | |
162 | * Read mdata->ptype before mdata->multi. | |
163 | */ | |
164 | smp_rmb(); | |
165 | multi = mdata->multi; | |
166 | /* | |
167 | * multi points to an array, therefore accessing the array | |
168 | * depends on reading multi. However, even in this case, | |
169 | * we must insure that the pointer is read _before_ the array | |
170 | * data. Same as rcu_dereference, but we need a full smp_rmb() | |
171 | * in the fast path, so put the explicit barrier here. | |
172 | */ | |
173 | smp_read_barrier_depends(); | |
174 | for (i = 0; multi[i].func; i++) { | |
75667d04 | 175 | va_start(args, regs); |
68c1021b | 176 | multi[i].func(mdata, multi[i].probe_private, |
75667d04 | 177 | regs, call_private, mdata->format, &args); |
68c1021b PMF |
178 | va_end(args); |
179 | } | |
180 | } | |
59b161cd | 181 | //ust// rcu_read_unlock_sched_notrace(); |
68c1021b | 182 | } |
59b161cd | 183 | //ust// EXPORT_SYMBOL_GPL(marker_probe_cb); |
68c1021b PMF |
184 | |
185 | /* | |
186 | * marker_probe_cb Callback that does not prepare the variable argument list. | |
187 | * @mdata: pointer of type struct marker | |
188 | * @call_private: caller site private data | |
189 | * @...: Variable argument list. | |
190 | * | |
191 | * Should be connected to markers "MARK_NOARGS". | |
192 | */ | |
193 | static notrace void marker_probe_cb_noarg(const struct marker *mdata, | |
75667d04 | 194 | void *call_private, struct registers *regs, ...) |
68c1021b PMF |
195 | { |
196 | va_list args; /* not initialized */ | |
197 | char ptype; | |
198 | ||
59b161cd | 199 | //ust// rcu_read_lock_sched_notrace(); |
68c1021b PMF |
200 | ptype = mdata->ptype; |
201 | if (likely(!ptype)) { | |
202 | marker_probe_func *func; | |
203 | /* Must read the ptype before ptr. They are not data dependant, | |
204 | * so we put an explicit smp_rmb() here. */ | |
205 | smp_rmb(); | |
206 | func = mdata->single.func; | |
207 | /* Must read the ptr before private data. They are not data | |
208 | * dependant, so we put an explicit smp_rmb() here. */ | |
209 | smp_rmb(); | |
75667d04 | 210 | func(mdata, mdata->single.probe_private, regs, call_private, |
68c1021b PMF |
211 | mdata->format, &args); |
212 | } else { | |
213 | struct marker_probe_closure *multi; | |
214 | int i; | |
215 | /* | |
216 | * Read mdata->ptype before mdata->multi. | |
217 | */ | |
218 | smp_rmb(); | |
219 | multi = mdata->multi; | |
220 | /* | |
221 | * multi points to an array, therefore accessing the array | |
222 | * depends on reading multi. However, even in this case, | |
223 | * we must insure that the pointer is read _before_ the array | |
224 | * data. Same as rcu_dereference, but we need a full smp_rmb() | |
225 | * in the fast path, so put the explicit barrier here. | |
226 | */ | |
227 | smp_read_barrier_depends(); | |
228 | for (i = 0; multi[i].func; i++) | |
75667d04 | 229 | multi[i].func(mdata, multi[i].probe_private, regs, |
68c1021b PMF |
230 | call_private, mdata->format, &args); |
231 | } | |
59b161cd | 232 | //ust// rcu_read_unlock_sched_notrace(); |
68c1021b PMF |
233 | } |
234 | ||
235 | static void free_old_closure(struct rcu_head *head) | |
236 | { | |
237 | struct marker_entry *entry = container_of(head, | |
238 | struct marker_entry, rcu); | |
909bc43f | 239 | free(entry->oldptr); |
68c1021b PMF |
240 | /* Make sure we free the data before setting the pending flag to 0 */ |
241 | smp_wmb(); | |
242 | entry->rcu_pending = 0; | |
243 | } | |
244 | ||
245 | static void debug_print_probes(struct marker_entry *entry) | |
246 | { | |
247 | int i; | |
248 | ||
249 | if (!marker_debug) | |
250 | return; | |
251 | ||
252 | if (!entry->ptype) { | |
c1f20530 | 253 | DBG("Single probe : %p %p", |
68c1021b PMF |
254 | entry->single.func, |
255 | entry->single.probe_private); | |
256 | } else { | |
257 | for (i = 0; entry->multi[i].func; i++) | |
c1f20530 | 258 | DBG("Multi probe %d : %p %p", i, |
68c1021b PMF |
259 | entry->multi[i].func, |
260 | entry->multi[i].probe_private); | |
261 | } | |
262 | } | |
263 | ||
264 | static struct marker_probe_closure * | |
265 | marker_entry_add_probe(struct marker_entry *entry, | |
266 | marker_probe_func *probe, void *probe_private) | |
267 | { | |
268 | int nr_probes = 0; | |
269 | struct marker_probe_closure *old, *new; | |
270 | ||
271 | WARN_ON(!probe); | |
272 | ||
273 | debug_print_probes(entry); | |
274 | old = entry->multi; | |
275 | if (!entry->ptype) { | |
276 | if (entry->single.func == probe && | |
277 | entry->single.probe_private == probe_private) | |
278 | return ERR_PTR(-EBUSY); | |
279 | if (entry->single.func == __mark_empty_function) { | |
280 | /* 0 -> 1 probes */ | |
281 | entry->single.func = probe; | |
282 | entry->single.probe_private = probe_private; | |
283 | entry->refcount = 1; | |
284 | entry->ptype = 0; | |
285 | debug_print_probes(entry); | |
286 | return NULL; | |
287 | } else { | |
288 | /* 1 -> 2 probes */ | |
289 | nr_probes = 1; | |
290 | old = NULL; | |
291 | } | |
292 | } else { | |
293 | /* (N -> N+1), (N != 0, 1) probes */ | |
294 | for (nr_probes = 0; old[nr_probes].func; nr_probes++) | |
295 | if (old[nr_probes].func == probe | |
296 | && old[nr_probes].probe_private | |
297 | == probe_private) | |
298 | return ERR_PTR(-EBUSY); | |
299 | } | |
300 | /* + 2 : one for new probe, one for NULL func */ | |
909bc43f | 301 | new = zmalloc((nr_probes + 2) * sizeof(struct marker_probe_closure)); |
68c1021b PMF |
302 | if (new == NULL) |
303 | return ERR_PTR(-ENOMEM); | |
304 | if (!old) | |
305 | new[0] = entry->single; | |
306 | else | |
307 | memcpy(new, old, | |
308 | nr_probes * sizeof(struct marker_probe_closure)); | |
309 | new[nr_probes].func = probe; | |
310 | new[nr_probes].probe_private = probe_private; | |
311 | entry->refcount = nr_probes + 1; | |
312 | entry->multi = new; | |
313 | entry->ptype = 1; | |
314 | debug_print_probes(entry); | |
315 | return old; | |
316 | } | |
317 | ||
318 | static struct marker_probe_closure * | |
319 | marker_entry_remove_probe(struct marker_entry *entry, | |
320 | marker_probe_func *probe, void *probe_private) | |
321 | { | |
322 | int nr_probes = 0, nr_del = 0, i; | |
323 | struct marker_probe_closure *old, *new; | |
324 | ||
325 | old = entry->multi; | |
326 | ||
327 | debug_print_probes(entry); | |
328 | if (!entry->ptype) { | |
329 | /* 0 -> N is an error */ | |
330 | WARN_ON(entry->single.func == __mark_empty_function); | |
331 | /* 1 -> 0 probes */ | |
332 | WARN_ON(probe && entry->single.func != probe); | |
333 | WARN_ON(entry->single.probe_private != probe_private); | |
334 | entry->single.func = __mark_empty_function; | |
335 | entry->refcount = 0; | |
336 | entry->ptype = 0; | |
337 | debug_print_probes(entry); | |
338 | return NULL; | |
339 | } else { | |
340 | /* (N -> M), (N > 1, M >= 0) probes */ | |
341 | for (nr_probes = 0; old[nr_probes].func; nr_probes++) { | |
342 | if ((!probe || old[nr_probes].func == probe) | |
343 | && old[nr_probes].probe_private | |
344 | == probe_private) | |
345 | nr_del++; | |
346 | } | |
347 | } | |
348 | ||
349 | if (nr_probes - nr_del == 0) { | |
350 | /* N -> 0, (N > 1) */ | |
351 | entry->single.func = __mark_empty_function; | |
352 | entry->refcount = 0; | |
353 | entry->ptype = 0; | |
354 | } else if (nr_probes - nr_del == 1) { | |
355 | /* N -> 1, (N > 1) */ | |
356 | for (i = 0; old[i].func; i++) | |
357 | if ((probe && old[i].func != probe) || | |
358 | old[i].probe_private != probe_private) | |
359 | entry->single = old[i]; | |
360 | entry->refcount = 1; | |
361 | entry->ptype = 0; | |
362 | } else { | |
363 | int j = 0; | |
364 | /* N -> M, (N > 1, M > 1) */ | |
365 | /* + 1 for NULL */ | |
909bc43f | 366 | new = zmalloc((nr_probes - nr_del + 1) * sizeof(struct marker_probe_closure)); |
68c1021b PMF |
367 | if (new == NULL) |
368 | return ERR_PTR(-ENOMEM); | |
369 | for (i = 0; old[i].func; i++) | |
370 | if ((probe && old[i].func != probe) || | |
371 | old[i].probe_private != probe_private) | |
372 | new[j++] = old[i]; | |
373 | entry->refcount = nr_probes - nr_del; | |
374 | entry->ptype = 1; | |
375 | entry->multi = new; | |
376 | } | |
377 | debug_print_probes(entry); | |
378 | return old; | |
379 | } | |
380 | ||
381 | /* | |
382 | * Get marker if the marker is present in the marker hash table. | |
383 | * Must be called with markers_mutex held. | |
384 | * Returns NULL if not present. | |
385 | */ | |
386 | static struct marker_entry *get_marker(const char *channel, const char *name) | |
387 | { | |
388 | struct hlist_head *head; | |
389 | struct hlist_node *node; | |
390 | struct marker_entry *e; | |
391 | size_t channel_len = strlen(channel) + 1; | |
392 | size_t name_len = strlen(name) + 1; | |
393 | u32 hash; | |
394 | ||
395 | hash = jhash(channel, channel_len-1, 0) ^ jhash(name, name_len-1, 0); | |
396 | head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; | |
397 | hlist_for_each_entry(e, node, head, hlist) { | |
398 | if (!strcmp(channel, e->channel) && !strcmp(name, e->name)) | |
399 | return e; | |
400 | } | |
401 | return NULL; | |
402 | } | |
403 | ||
404 | /* | |
405 | * Add the marker to the marker hash table. Must be called with markers_mutex | |
406 | * held. | |
407 | */ | |
408 | static struct marker_entry *add_marker(const char *channel, const char *name, | |
409 | const char *format) | |
410 | { | |
411 | struct hlist_head *head; | |
412 | struct hlist_node *node; | |
413 | struct marker_entry *e; | |
414 | size_t channel_len = strlen(channel) + 1; | |
415 | size_t name_len = strlen(name) + 1; | |
416 | size_t format_len = 0; | |
417 | u32 hash; | |
418 | ||
419 | hash = jhash(channel, channel_len-1, 0) ^ jhash(name, name_len-1, 0); | |
420 | if (format) | |
421 | format_len = strlen(format) + 1; | |
422 | head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; | |
423 | hlist_for_each_entry(e, node, head, hlist) { | |
424 | if (!strcmp(channel, e->channel) && !strcmp(name, e->name)) { | |
c1f20530 | 425 | DBG("Marker %s.%s busy", channel, name); |
68c1021b PMF |
426 | return ERR_PTR(-EBUSY); /* Already there */ |
427 | } | |
428 | } | |
429 | /* | |
909bc43f | 430 | * Using malloc here to allocate a variable length element. Could |
68c1021b PMF |
431 | * cause some memory fragmentation if overused. |
432 | */ | |
909bc43f PMF |
433 | e = malloc(sizeof(struct marker_entry) |
434 | + channel_len + name_len + format_len); | |
68c1021b PMF |
435 | if (!e) |
436 | return ERR_PTR(-ENOMEM); | |
437 | memcpy(e->channel, channel, channel_len); | |
438 | e->name = &e->channel[channel_len]; | |
439 | memcpy(e->name, name, name_len); | |
440 | if (format) { | |
441 | e->format = &e->name[channel_len + name_len]; | |
442 | memcpy(e->format, format, format_len); | |
443 | if (strcmp(e->format, MARK_NOARGS) == 0) | |
444 | e->call = marker_probe_cb_noarg; | |
445 | else | |
446 | e->call = marker_probe_cb; | |
447 | trace_mark(metadata, core_marker_format, | |
448 | "channel %s name %s format %s", | |
449 | e->channel, e->name, e->format); | |
450 | } else { | |
451 | e->format = NULL; | |
452 | e->call = marker_probe_cb; | |
453 | } | |
454 | e->single.func = __mark_empty_function; | |
455 | e->single.probe_private = NULL; | |
456 | e->multi = NULL; | |
457 | e->ptype = 0; | |
458 | e->format_allocated = 0; | |
459 | e->refcount = 0; | |
460 | e->rcu_pending = 0; | |
461 | hlist_add_head(&e->hlist, head); | |
462 | return e; | |
463 | } | |
464 | ||
465 | /* | |
466 | * Remove the marker from the marker hash table. Must be called with mutex_lock | |
467 | * held. | |
468 | */ | |
469 | static int remove_marker(const char *channel, const char *name) | |
470 | { | |
471 | struct hlist_head *head; | |
472 | struct hlist_node *node; | |
473 | struct marker_entry *e; | |
474 | int found = 0; | |
475 | size_t channel_len = strlen(channel) + 1; | |
476 | size_t name_len = strlen(name) + 1; | |
477 | u32 hash; | |
478 | int ret; | |
479 | ||
480 | hash = jhash(channel, channel_len-1, 0) ^ jhash(name, name_len-1, 0); | |
481 | head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; | |
482 | hlist_for_each_entry(e, node, head, hlist) { | |
483 | if (!strcmp(channel, e->channel) && !strcmp(name, e->name)) { | |
484 | found = 1; | |
485 | break; | |
486 | } | |
487 | } | |
488 | if (!found) | |
489 | return -ENOENT; | |
490 | if (e->single.func != __mark_empty_function) | |
491 | return -EBUSY; | |
492 | hlist_del(&e->hlist); | |
493 | if (e->format_allocated) | |
909bc43f | 494 | free(e->format); |
68c1021b PMF |
495 | ret = ltt_channels_unregister(e->channel); |
496 | WARN_ON(ret); | |
497 | /* Make sure the call_rcu has been executed */ | |
6cb88bc0 PMF |
498 | //ust// if (e->rcu_pending) |
499 | //ust// rcu_barrier_sched(); | |
909bc43f | 500 | free(e); |
68c1021b PMF |
501 | return 0; |
502 | } | |
503 | ||
504 | /* | |
505 | * Set the mark_entry format to the format found in the element. | |
506 | */ | |
507 | static int marker_set_format(struct marker_entry *entry, const char *format) | |
508 | { | |
909bc43f | 509 | entry->format = strdup(format); |
68c1021b PMF |
510 | if (!entry->format) |
511 | return -ENOMEM; | |
512 | entry->format_allocated = 1; | |
513 | ||
514 | trace_mark(metadata, core_marker_format, | |
515 | "channel %s name %s format %s", | |
516 | entry->channel, entry->name, entry->format); | |
517 | return 0; | |
518 | } | |
519 | ||
520 | /* | |
521 | * Sets the probe callback corresponding to one marker. | |
522 | */ | |
523 | static int set_marker(struct marker_entry *entry, struct marker *elem, | |
524 | int active) | |
525 | { | |
526 | int ret = 0; | |
527 | WARN_ON(strcmp(entry->name, elem->name) != 0); | |
528 | ||
529 | if (entry->format) { | |
530 | if (strcmp(entry->format, elem->format) != 0) { | |
c1f20530 | 531 | DBG("Format mismatch for probe %s (%s), marker (%s)", |
68c1021b PMF |
532 | entry->name, |
533 | entry->format, | |
534 | elem->format); | |
535 | return -EPERM; | |
536 | } | |
537 | } else { | |
538 | ret = marker_set_format(entry, elem->format); | |
539 | if (ret) | |
540 | return ret; | |
541 | } | |
542 | ||
543 | /* | |
544 | * probe_cb setup (statically known) is done here. It is | |
545 | * asynchronous with the rest of execution, therefore we only | |
546 | * pass from a "safe" callback (with argument) to an "unsafe" | |
547 | * callback (does not set arguments). | |
548 | */ | |
549 | elem->call = entry->call; | |
550 | elem->channel_id = entry->channel_id; | |
551 | elem->event_id = entry->event_id; | |
552 | /* | |
553 | * Sanity check : | |
554 | * We only update the single probe private data when the ptr is | |
555 | * set to a _non_ single probe! (0 -> 1 and N -> 1, N != 1) | |
556 | */ | |
557 | WARN_ON(elem->single.func != __mark_empty_function | |
558 | && elem->single.probe_private != entry->single.probe_private | |
559 | && !elem->ptype); | |
560 | elem->single.probe_private = entry->single.probe_private; | |
561 | /* | |
562 | * Make sure the private data is valid when we update the | |
563 | * single probe ptr. | |
564 | */ | |
565 | smp_wmb(); | |
566 | elem->single.func = entry->single.func; | |
567 | /* | |
568 | * We also make sure that the new probe callbacks array is consistent | |
569 | * before setting a pointer to it. | |
570 | */ | |
571 | rcu_assign_pointer(elem->multi, entry->multi); | |
572 | /* | |
573 | * Update the function or multi probe array pointer before setting the | |
574 | * ptype. | |
575 | */ | |
576 | smp_wmb(); | |
577 | elem->ptype = entry->ptype; | |
578 | ||
59b161cd PMF |
579 | //ust// if (elem->tp_name && (active ^ _imv_read(elem->state))) { |
580 | //ust// WARN_ON(!elem->tp_cb); | |
581 | //ust// /* | |
582 | //ust// * It is ok to directly call the probe registration because type | |
583 | //ust// * checking has been done in the __trace_mark_tp() macro. | |
584 | //ust// */ | |
585 | //ust// | |
586 | //ust// if (active) { | |
587 | //ust// /* | |
588 | //ust// * try_module_get should always succeed because we hold | |
589 | //ust// * markers_mutex to get the tp_cb address. | |
590 | //ust// */ | |
591 | //ust// ret = try_module_get(__module_text_address( | |
592 | //ust// (unsigned long)elem->tp_cb)); | |
593 | //ust// BUG_ON(!ret); | |
594 | //ust// ret = tracepoint_probe_register_noupdate( | |
595 | //ust// elem->tp_name, | |
596 | //ust// elem->tp_cb); | |
597 | //ust// } else { | |
598 | //ust// ret = tracepoint_probe_unregister_noupdate( | |
599 | //ust// elem->tp_name, | |
600 | //ust// elem->tp_cb); | |
601 | //ust// /* | |
602 | //ust// * tracepoint_probe_update_all() must be called | |
603 | //ust// * before the module containing tp_cb is unloaded. | |
604 | //ust// */ | |
605 | //ust// module_put(__module_text_address( | |
606 | //ust// (unsigned long)elem->tp_cb)); | |
607 | //ust// } | |
608 | //ust// } | |
68c1021b PMF |
609 | elem->state__imv = active; |
610 | ||
611 | return ret; | |
612 | } | |
613 | ||
614 | /* | |
615 | * Disable a marker and its probe callback. | |
616 | * Note: only waiting an RCU period after setting elem->call to the empty | |
617 | * function insures that the original callback is not used anymore. This insured | |
618 | * by rcu_read_lock_sched around the call site. | |
619 | */ | |
620 | static void disable_marker(struct marker *elem) | |
621 | { | |
772030fe PMF |
622 | //ust// int ret; |
623 | //ust// | |
624 | //ust// /* leave "call" as is. It is known statically. */ | |
59b161cd PMF |
625 | //ust// if (elem->tp_name && _imv_read(elem->state)) { |
626 | //ust// WARN_ON(!elem->tp_cb); | |
627 | //ust// /* | |
628 | //ust// * It is ok to directly call the probe registration because type | |
629 | //ust// * checking has been done in the __trace_mark_tp() macro. | |
630 | //ust// */ | |
631 | //ust// ret = tracepoint_probe_unregister_noupdate(elem->tp_name, | |
632 | //ust// elem->tp_cb); | |
633 | //ust// WARN_ON(ret); | |
634 | //ust// /* | |
635 | //ust// * tracepoint_probe_update_all() must be called | |
636 | //ust// * before the module containing tp_cb is unloaded. | |
637 | //ust// */ | |
638 | //ust// module_put(__module_text_address((unsigned long)elem->tp_cb)); | |
639 | //ust// } | |
68c1021b PMF |
640 | elem->state__imv = 0; |
641 | elem->single.func = __mark_empty_function; | |
642 | /* Update the function before setting the ptype */ | |
643 | smp_wmb(); | |
644 | elem->ptype = 0; /* single probe */ | |
645 | /* | |
646 | * Leave the private data and channel_id/event_id there, because removal | |
647 | * is racy and should be done only after an RCU period. These are never | |
648 | * used until the next initialization anyway. | |
649 | */ | |
650 | } | |
651 | ||
a5311005 PMF |
652 | /* |
653 | * is_marker_enabled - Check if a marker is enabled | |
654 | * @channel: channel name | |
655 | * @name: marker name | |
656 | * | |
657 | * Returns 1 if the marker is enabled, 0 if disabled. | |
658 | */ | |
659 | int is_marker_enabled(const char *channel, const char *name) | |
660 | { | |
661 | struct marker_entry *entry; | |
662 | ||
663 | mutex_lock(&markers_mutex); | |
664 | entry = get_marker(channel, name); | |
665 | mutex_unlock(&markers_mutex); | |
666 | ||
667 | return entry && !!entry->refcount; | |
668 | } | |
669 | ||
68c1021b PMF |
670 | /** |
671 | * marker_update_probe_range - Update a probe range | |
672 | * @begin: beginning of the range | |
673 | * @end: end of the range | |
674 | * | |
675 | * Updates the probe callback corresponding to a range of markers. | |
676 | */ | |
677 | void marker_update_probe_range(struct marker *begin, | |
678 | struct marker *end) | |
679 | { | |
680 | struct marker *iter; | |
681 | struct marker_entry *mark_entry; | |
682 | ||
683 | mutex_lock(&markers_mutex); | |
684 | for (iter = begin; iter < end; iter++) { | |
685 | mark_entry = get_marker(iter->channel, iter->name); | |
686 | if (mark_entry) { | |
687 | set_marker(mark_entry, iter, !!mark_entry->refcount); | |
688 | /* | |
689 | * ignore error, continue | |
690 | */ | |
4db647c5 PMF |
691 | |
692 | /* This is added for UST. We emit a core_marker_id event | |
693 | * for markers that are already registered to a probe | |
694 | * upon library load. Otherwise, no core_marker_id will | |
695 | * be generated for these markers. Is this the right thing | |
696 | * to do? | |
697 | */ | |
698 | trace_mark(metadata, core_marker_id, | |
699 | "channel %s name %s event_id %hu " | |
700 | "int #1u%zu long #1u%zu pointer #1u%zu " | |
701 | "size_t #1u%zu alignment #1u%u", | |
702 | iter->channel, iter->name, mark_entry->event_id, | |
703 | sizeof(int), sizeof(long), sizeof(void *), | |
704 | sizeof(size_t), ltt_get_alignment()); | |
68c1021b PMF |
705 | } else { |
706 | disable_marker(iter); | |
707 | } | |
708 | } | |
709 | mutex_unlock(&markers_mutex); | |
710 | } | |
711 | ||
772030fe PMF |
712 | static void lib_update_markers(void) |
713 | { | |
714 | struct lib *lib; | |
715 | ||
716 | /* FIXME: we should probably take a mutex here on libs */ | |
717 | //ust// mutex_lock(&module_mutex); | |
718 | list_for_each_entry(lib, &libs, list) | |
719 | marker_update_probe_range(lib->markers_start, | |
720 | lib->markers_start + lib->markers_count); | |
721 | //ust// mutex_unlock(&module_mutex); | |
722 | } | |
723 | ||
68c1021b PMF |
724 | /* |
725 | * Update probes, removing the faulty probes. | |
726 | * | |
727 | * Internal callback only changed before the first probe is connected to it. | |
728 | * Single probe private data can only be changed on 0 -> 1 and 2 -> 1 | |
729 | * transitions. All other transitions will leave the old private data valid. | |
730 | * This makes the non-atomicity of the callback/private data updates valid. | |
731 | * | |
732 | * "special case" updates : | |
733 | * 0 -> 1 callback | |
734 | * 1 -> 0 callback | |
735 | * 1 -> 2 callbacks | |
736 | * 2 -> 1 callbacks | |
737 | * Other updates all behave the same, just like the 2 -> 3 or 3 -> 2 updates. | |
738 | * Site effect : marker_set_format may delete the marker entry (creating a | |
739 | * replacement). | |
740 | */ | |
741 | static void marker_update_probes(void) | |
742 | { | |
743 | /* Core kernel markers */ | |
c463904d | 744 | //ust// marker_update_probe_range(__start___markers, __stop___markers); |
68c1021b | 745 | /* Markers in modules. */ |
59b161cd | 746 | //ust// module_update_markers(); |
c463904d | 747 | lib_update_markers(); |
b6bf28ec | 748 | //ust// tracepoint_probe_update_all(); |
68c1021b PMF |
749 | /* Update immediate values */ |
750 | core_imv_update(); | |
474d745f | 751 | //ust// module_imv_update(); /* FIXME: need to port for libs? */ |
68c1021b PMF |
752 | marker_update_processes(); |
753 | } | |
754 | ||
755 | /** | |
756 | * marker_probe_register - Connect a probe to a marker | |
757 | * @channel: marker channel | |
758 | * @name: marker name | |
759 | * @format: format string | |
760 | * @probe: probe handler | |
761 | * @probe_private: probe private data | |
762 | * | |
763 | * private data must be a valid allocated memory address, or NULL. | |
764 | * Returns 0 if ok, error value on error. | |
765 | * The probe address must at least be aligned on the architecture pointer size. | |
766 | */ | |
767 | int marker_probe_register(const char *channel, const char *name, | |
768 | const char *format, marker_probe_func *probe, | |
769 | void *probe_private) | |
770 | { | |
771 | struct marker_entry *entry; | |
772 | int ret = 0, ret_err; | |
773 | struct marker_probe_closure *old; | |
774 | int first_probe = 0; | |
775 | ||
776 | mutex_lock(&markers_mutex); | |
777 | entry = get_marker(channel, name); | |
778 | if (!entry) { | |
779 | first_probe = 1; | |
780 | entry = add_marker(channel, name, format); | |
781 | if (IS_ERR(entry)) | |
782 | ret = PTR_ERR(entry); | |
783 | if (ret) | |
784 | goto end; | |
785 | ret = ltt_channels_register(channel); | |
786 | if (ret) | |
787 | goto error_remove_marker; | |
788 | ret = ltt_channels_get_index_from_name(channel); | |
789 | if (ret < 0) | |
790 | goto error_unregister_channel; | |
791 | entry->channel_id = ret; | |
792 | ret = ltt_channels_get_event_id(channel, name); | |
793 | if (ret < 0) | |
794 | goto error_unregister_channel; | |
795 | entry->event_id = ret; | |
796 | ret = 0; | |
797 | trace_mark(metadata, core_marker_id, | |
798 | "channel %s name %s event_id %hu " | |
799 | "int #1u%zu long #1u%zu pointer #1u%zu " | |
800 | "size_t #1u%zu alignment #1u%u", | |
801 | channel, name, entry->event_id, | |
802 | sizeof(int), sizeof(long), sizeof(void *), | |
803 | sizeof(size_t), ltt_get_alignment()); | |
804 | } else if (format) { | |
805 | if (!entry->format) | |
806 | ret = marker_set_format(entry, format); | |
807 | else if (strcmp(entry->format, format)) | |
808 | ret = -EPERM; | |
809 | if (ret) | |
810 | goto end; | |
811 | } | |
812 | ||
813 | /* | |
814 | * If we detect that a call_rcu is pending for this marker, | |
815 | * make sure it's executed now. | |
816 | */ | |
6cb88bc0 PMF |
817 | //ust// if (entry->rcu_pending) |
818 | //ust// rcu_barrier_sched(); | |
68c1021b PMF |
819 | old = marker_entry_add_probe(entry, probe, probe_private); |
820 | if (IS_ERR(old)) { | |
821 | ret = PTR_ERR(old); | |
822 | if (first_probe) | |
823 | goto error_unregister_channel; | |
824 | else | |
825 | goto end; | |
826 | } | |
827 | mutex_unlock(&markers_mutex); | |
828 | ||
79e36890 | 829 | /* Activate marker if necessary */ |
68c1021b PMF |
830 | marker_update_probes(); |
831 | ||
832 | mutex_lock(&markers_mutex); | |
833 | entry = get_marker(channel, name); | |
834 | if (!entry) | |
835 | goto end; | |
6cb88bc0 PMF |
836 | //ust// if (entry->rcu_pending) |
837 | //ust// rcu_barrier_sched(); | |
68c1021b PMF |
838 | entry->oldptr = old; |
839 | entry->rcu_pending = 1; | |
840 | /* write rcu_pending before calling the RCU callback */ | |
841 | smp_wmb(); | |
6cb88bc0 PMF |
842 | //ust// call_rcu_sched(&entry->rcu, free_old_closure); |
843 | synchronize_rcu(); free_old_closure(&entry->rcu); | |
68c1021b PMF |
844 | goto end; |
845 | ||
846 | error_unregister_channel: | |
847 | ret_err = ltt_channels_unregister(channel); | |
848 | WARN_ON(ret_err); | |
849 | error_remove_marker: | |
850 | ret_err = remove_marker(channel, name); | |
851 | WARN_ON(ret_err); | |
852 | end: | |
853 | mutex_unlock(&markers_mutex); | |
854 | return ret; | |
855 | } | |
59b161cd | 856 | //ust// EXPORT_SYMBOL_GPL(marker_probe_register); |
68c1021b PMF |
857 | |
858 | /** | |
859 | * marker_probe_unregister - Disconnect a probe from a marker | |
860 | * @channel: marker channel | |
861 | * @name: marker name | |
862 | * @probe: probe function pointer | |
863 | * @probe_private: probe private data | |
864 | * | |
865 | * Returns the private data given to marker_probe_register, or an ERR_PTR(). | |
866 | * We do not need to call a synchronize_sched to make sure the probes have | |
867 | * finished running before doing a module unload, because the module unload | |
868 | * itself uses stop_machine(), which insures that every preempt disabled section | |
869 | * have finished. | |
870 | */ | |
871 | int marker_probe_unregister(const char *channel, const char *name, | |
872 | marker_probe_func *probe, void *probe_private) | |
873 | { | |
874 | struct marker_entry *entry; | |
875 | struct marker_probe_closure *old; | |
876 | int ret = -ENOENT; | |
877 | ||
878 | mutex_lock(&markers_mutex); | |
879 | entry = get_marker(channel, name); | |
880 | if (!entry) | |
881 | goto end; | |
6cb88bc0 PMF |
882 | //ust// if (entry->rcu_pending) |
883 | //ust// rcu_barrier_sched(); | |
68c1021b PMF |
884 | old = marker_entry_remove_probe(entry, probe, probe_private); |
885 | mutex_unlock(&markers_mutex); | |
886 | ||
887 | marker_update_probes(); | |
888 | ||
889 | mutex_lock(&markers_mutex); | |
890 | entry = get_marker(channel, name); | |
891 | if (!entry) | |
892 | goto end; | |
6cb88bc0 PMF |
893 | //ust// if (entry->rcu_pending) |
894 | //ust// rcu_barrier_sched(); | |
68c1021b PMF |
895 | entry->oldptr = old; |
896 | entry->rcu_pending = 1; | |
897 | /* write rcu_pending before calling the RCU callback */ | |
898 | smp_wmb(); | |
6cb88bc0 PMF |
899 | //ust// call_rcu_sched(&entry->rcu, free_old_closure); |
900 | synchronize_rcu(); free_old_closure(&entry->rcu); | |
68c1021b PMF |
901 | remove_marker(channel, name); /* Ignore busy error message */ |
902 | ret = 0; | |
903 | end: | |
904 | mutex_unlock(&markers_mutex); | |
905 | return ret; | |
906 | } | |
59b161cd | 907 | //ust// EXPORT_SYMBOL_GPL(marker_probe_unregister); |
68c1021b PMF |
908 | |
909 | static struct marker_entry * | |
910 | get_marker_from_private_data(marker_probe_func *probe, void *probe_private) | |
911 | { | |
912 | struct marker_entry *entry; | |
913 | unsigned int i; | |
914 | struct hlist_head *head; | |
915 | struct hlist_node *node; | |
916 | ||
917 | for (i = 0; i < MARKER_TABLE_SIZE; i++) { | |
918 | head = &marker_table[i]; | |
919 | hlist_for_each_entry(entry, node, head, hlist) { | |
920 | if (!entry->ptype) { | |
921 | if (entry->single.func == probe | |
922 | && entry->single.probe_private | |
923 | == probe_private) | |
924 | return entry; | |
925 | } else { | |
926 | struct marker_probe_closure *closure; | |
927 | closure = entry->multi; | |
928 | for (i = 0; closure[i].func; i++) { | |
929 | if (closure[i].func == probe && | |
930 | closure[i].probe_private | |
931 | == probe_private) | |
932 | return entry; | |
933 | } | |
934 | } | |
935 | } | |
936 | } | |
937 | return NULL; | |
938 | } | |
939 | ||
940 | /** | |
941 | * marker_probe_unregister_private_data - Disconnect a probe from a marker | |
942 | * @probe: probe function | |
943 | * @probe_private: probe private data | |
944 | * | |
945 | * Unregister a probe by providing the registered private data. | |
946 | * Only removes the first marker found in hash table. | |
947 | * Return 0 on success or error value. | |
948 | * We do not need to call a synchronize_sched to make sure the probes have | |
949 | * finished running before doing a module unload, because the module unload | |
950 | * itself uses stop_machine(), which insures that every preempt disabled section | |
951 | * have finished. | |
952 | */ | |
953 | int marker_probe_unregister_private_data(marker_probe_func *probe, | |
954 | void *probe_private) | |
955 | { | |
956 | struct marker_entry *entry; | |
957 | int ret = 0; | |
958 | struct marker_probe_closure *old; | |
909bc43f | 959 | char *channel = NULL, *name = NULL; |
68c1021b PMF |
960 | |
961 | mutex_lock(&markers_mutex); | |
962 | entry = get_marker_from_private_data(probe, probe_private); | |
963 | if (!entry) { | |
964 | ret = -ENOENT; | |
965 | goto end; | |
966 | } | |
6cb88bc0 PMF |
967 | //ust// if (entry->rcu_pending) |
968 | //ust// rcu_barrier_sched(); | |
68c1021b | 969 | old = marker_entry_remove_probe(entry, NULL, probe_private); |
909bc43f PMF |
970 | channel = strdup(entry->channel); |
971 | name = strdup(entry->name); | |
68c1021b PMF |
972 | mutex_unlock(&markers_mutex); |
973 | ||
974 | marker_update_probes(); | |
975 | ||
976 | mutex_lock(&markers_mutex); | |
977 | entry = get_marker(channel, name); | |
978 | if (!entry) | |
979 | goto end; | |
6cb88bc0 PMF |
980 | //ust// if (entry->rcu_pending) |
981 | //ust// rcu_barrier_sched(); | |
68c1021b PMF |
982 | entry->oldptr = old; |
983 | entry->rcu_pending = 1; | |
984 | /* write rcu_pending before calling the RCU callback */ | |
985 | smp_wmb(); | |
6cb88bc0 PMF |
986 | //ust// call_rcu_sched(&entry->rcu, free_old_closure); |
987 | synchronize_rcu(); free_old_closure(&entry->rcu); | |
68c1021b PMF |
988 | /* Ignore busy error message */ |
989 | remove_marker(channel, name); | |
990 | end: | |
991 | mutex_unlock(&markers_mutex); | |
909bc43f PMF |
992 | free(channel); |
993 | free(name); | |
68c1021b PMF |
994 | return ret; |
995 | } | |
59b161cd | 996 | //ust// EXPORT_SYMBOL_GPL(marker_probe_unregister_private_data); |
68c1021b PMF |
997 | |
998 | /** | |
999 | * marker_get_private_data - Get a marker's probe private data | |
1000 | * @channel: marker channel | |
1001 | * @name: marker name | |
1002 | * @probe: probe to match | |
1003 | * @num: get the nth matching probe's private data | |
1004 | * | |
1005 | * Returns the nth private data pointer (starting from 0) matching, or an | |
1006 | * ERR_PTR. | |
1007 | * Returns the private data pointer, or an ERR_PTR. | |
1008 | * The private data pointer should _only_ be dereferenced if the caller is the | |
1009 | * owner of the data, or its content could vanish. This is mostly used to | |
1010 | * confirm that a caller is the owner of a registered probe. | |
1011 | */ | |
1012 | void *marker_get_private_data(const char *channel, const char *name, | |
1013 | marker_probe_func *probe, int num) | |
1014 | { | |
1015 | struct hlist_head *head; | |
1016 | struct hlist_node *node; | |
1017 | struct marker_entry *e; | |
1018 | size_t channel_len = strlen(channel) + 1; | |
1019 | size_t name_len = strlen(name) + 1; | |
1020 | int i; | |
1021 | u32 hash; | |
1022 | ||
1023 | hash = jhash(channel, channel_len-1, 0) ^ jhash(name, name_len-1, 0); | |
1024 | head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; | |
1025 | hlist_for_each_entry(e, node, head, hlist) { | |
1026 | if (!strcmp(channel, e->channel) && !strcmp(name, e->name)) { | |
1027 | if (!e->ptype) { | |
1028 | if (num == 0 && e->single.func == probe) | |
1029 | return e->single.probe_private; | |
1030 | } else { | |
1031 | struct marker_probe_closure *closure; | |
1032 | int match = 0; | |
1033 | closure = e->multi; | |
1034 | for (i = 0; closure[i].func; i++) { | |
1035 | if (closure[i].func != probe) | |
1036 | continue; | |
1037 | if (match++ == num) | |
1038 | return closure[i].probe_private; | |
1039 | } | |
1040 | } | |
1041 | break; | |
1042 | } | |
1043 | } | |
1044 | return ERR_PTR(-ENOENT); | |
1045 | } | |
59b161cd | 1046 | //ust// EXPORT_SYMBOL_GPL(marker_get_private_data); |
68c1021b PMF |
1047 | |
1048 | /** | |
1049 | * markers_compact_event_ids - Compact markers event IDs and reassign channels | |
1050 | * | |
1051 | * Called when no channel users are active by the channel infrastructure. | |
1052 | * Called with lock_markers() and channel mutex held. | |
1053 | */ | |
59b161cd PMF |
1054 | //ust// void markers_compact_event_ids(void) |
1055 | //ust// { | |
1056 | //ust// struct marker_entry *entry; | |
1057 | //ust// unsigned int i; | |
1058 | //ust// struct hlist_head *head; | |
1059 | //ust// struct hlist_node *node; | |
1060 | //ust// int ret; | |
1061 | //ust// | |
1062 | //ust// for (i = 0; i < MARKER_TABLE_SIZE; i++) { | |
1063 | //ust// head = &marker_table[i]; | |
1064 | //ust// hlist_for_each_entry(entry, node, head, hlist) { | |
1065 | //ust// ret = ltt_channels_get_index_from_name(entry->channel); | |
1066 | //ust// WARN_ON(ret < 0); | |
1067 | //ust// entry->channel_id = ret; | |
1068 | //ust// ret = _ltt_channels_get_event_id(entry->channel, | |
1069 | //ust// entry->name); | |
1070 | //ust// WARN_ON(ret < 0); | |
1071 | //ust// entry->event_id = ret; | |
1072 | //ust// } | |
1073 | //ust// } | |
1074 | //ust// } | |
68c1021b | 1075 | |
9c67dc50 | 1076 | //ust//#ifdef CONFIG_MODULES |
68c1021b | 1077 | |
772030fe PMF |
1078 | /* |
1079 | * Returns 0 if current not found. | |
1080 | * Returns 1 if current found. | |
1081 | */ | |
1082 | int lib_get_iter_markers(struct marker_iter *iter) | |
1083 | { | |
1084 | struct lib *iter_lib; | |
1085 | int found = 0; | |
1086 | ||
1087 | //ust// mutex_lock(&module_mutex); | |
1088 | list_for_each_entry(iter_lib, &libs, list) { | |
1089 | if (iter_lib < iter->lib) | |
1090 | continue; | |
1091 | else if (iter_lib > iter->lib) | |
1092 | iter->marker = NULL; | |
1093 | found = marker_get_iter_range(&iter->marker, | |
1094 | iter_lib->markers_start, | |
1095 | iter_lib->markers_start + iter_lib->markers_count); | |
1096 | if (found) { | |
1097 | iter->lib = iter_lib; | |
1098 | break; | |
1099 | } | |
1100 | } | |
1101 | //ust// mutex_unlock(&module_mutex); | |
1102 | return found; | |
1103 | } | |
1104 | ||
68c1021b PMF |
1105 | /** |
1106 | * marker_get_iter_range - Get a next marker iterator given a range. | |
1107 | * @marker: current markers (in), next marker (out) | |
1108 | * @begin: beginning of the range | |
1109 | * @end: end of the range | |
1110 | * | |
1111 | * Returns whether a next marker has been found (1) or not (0). | |
1112 | * Will return the first marker in the range if the input marker is NULL. | |
1113 | */ | |
1114 | int marker_get_iter_range(struct marker **marker, struct marker *begin, | |
1115 | struct marker *end) | |
1116 | { | |
1117 | if (!*marker && begin != end) { | |
1118 | *marker = begin; | |
1119 | return 1; | |
1120 | } | |
1121 | if (*marker >= begin && *marker < end) | |
1122 | return 1; | |
1123 | return 0; | |
1124 | } | |
59b161cd | 1125 | //ust// EXPORT_SYMBOL_GPL(marker_get_iter_range); |
68c1021b PMF |
1126 | |
1127 | static void marker_get_iter(struct marker_iter *iter) | |
1128 | { | |
1129 | int found = 0; | |
1130 | ||
1131 | /* Core kernel markers */ | |
98963de4 | 1132 | if (!iter->lib) { |
c463904d | 1133 | /* ust FIXME: how come we cannot disable the following line? we shouldn't need core stuff */ |
68c1021b PMF |
1134 | found = marker_get_iter_range(&iter->marker, |
1135 | __start___markers, __stop___markers); | |
1136 | if (found) | |
1137 | goto end; | |
1138 | } | |
1139 | /* Markers in modules. */ | |
98963de4 | 1140 | found = lib_get_iter_markers(iter); |
68c1021b PMF |
1141 | end: |
1142 | if (!found) | |
1143 | marker_iter_reset(iter); | |
1144 | } | |
1145 | ||
1146 | void marker_iter_start(struct marker_iter *iter) | |
1147 | { | |
1148 | marker_get_iter(iter); | |
1149 | } | |
59b161cd | 1150 | //ust// EXPORT_SYMBOL_GPL(marker_iter_start); |
68c1021b PMF |
1151 | |
1152 | void marker_iter_next(struct marker_iter *iter) | |
1153 | { | |
1154 | iter->marker++; | |
1155 | /* | |
1156 | * iter->marker may be invalid because we blindly incremented it. | |
1157 | * Make sure it is valid by marshalling on the markers, getting the | |
1158 | * markers from following modules if necessary. | |
1159 | */ | |
1160 | marker_get_iter(iter); | |
1161 | } | |
59b161cd | 1162 | //ust// EXPORT_SYMBOL_GPL(marker_iter_next); |
68c1021b PMF |
1163 | |
1164 | void marker_iter_stop(struct marker_iter *iter) | |
1165 | { | |
1166 | } | |
59b161cd | 1167 | //ust// EXPORT_SYMBOL_GPL(marker_iter_stop); |
68c1021b PMF |
1168 | |
1169 | void marker_iter_reset(struct marker_iter *iter) | |
1170 | { | |
98963de4 | 1171 | iter->lib = NULL; |
68c1021b PMF |
1172 | iter->marker = NULL; |
1173 | } | |
59b161cd | 1174 | //ust// EXPORT_SYMBOL_GPL(marker_iter_reset); |
68c1021b PMF |
1175 | |
1176 | #ifdef CONFIG_MARKERS_USERSPACE | |
1177 | /* | |
1178 | * must be called with current->user_markers_mutex held | |
1179 | */ | |
1180 | static void free_user_marker(char __user *state, struct hlist_head *head) | |
1181 | { | |
1182 | struct user_marker *umark; | |
1183 | struct hlist_node *pos, *n; | |
1184 | ||
1185 | hlist_for_each_entry_safe(umark, pos, n, head, hlist) { | |
1186 | if (umark->state == state) { | |
1187 | hlist_del(&umark->hlist); | |
909bc43f | 1188 | free(umark); |
68c1021b PMF |
1189 | } |
1190 | } | |
1191 | } | |
1192 | ||
c1f20530 PMF |
1193 | /* |
1194 | * Update current process. | |
1195 | * Note that we have to wait a whole scheduler period before we are sure that | |
1196 | * every running userspace threads have their markers updated. | |
1197 | * (synchronize_sched() can be used to insure this). | |
1198 | */ | |
1199 | //ust// void marker_update_process(void) | |
59b161cd PMF |
1200 | //ust// { |
1201 | //ust// struct user_marker *umark; | |
c1f20530 | 1202 | //ust// struct hlist_node *pos; |
59b161cd | 1203 | //ust// struct marker_entry *entry; |
59b161cd | 1204 | //ust// |
c1f20530 PMF |
1205 | //ust// mutex_lock(&markers_mutex); |
1206 | //ust// mutex_lock(¤t->group_leader->user_markers_mutex); | |
1207 | //ust// if (strcmp(current->comm, "testprog") == 0) | |
1208 | //ust// DBG("do update pending for testprog"); | |
1209 | //ust// hlist_for_each_entry(umark, pos, | |
1210 | //ust// ¤t->group_leader->user_markers, hlist) { | |
1211 | //ust// DBG("Updating marker %s in %s", umark->name, current->comm); | |
59b161cd PMF |
1212 | //ust// entry = get_marker("userspace", umark->name); |
1213 | //ust// if (entry) { | |
1214 | //ust// if (entry->format && | |
1215 | //ust// strcmp(entry->format, umark->format) != 0) { | |
c1f20530 | 1216 | //ust// WARN("error, wrong format in process %s", |
59b161cd | 1217 | //ust// current->comm); |
c1f20530 | 1218 | //ust// break; |
59b161cd | 1219 | //ust// } |
c1f20530 PMF |
1220 | //ust// if (put_user(!!entry->refcount, umark->state)) { |
1221 | //ust// WARN("Marker in %s caused a fault", | |
1222 | //ust// current->comm); | |
1223 | //ust// break; | |
59b161cd | 1224 | //ust// } |
59b161cd | 1225 | //ust// } else { |
59b161cd | 1226 | //ust// if (put_user(0, umark->state)) { |
c1f20530 PMF |
1227 | //ust// WARN("Marker in %s caused a fault", current->comm); |
1228 | //ust// break; | |
59b161cd PMF |
1229 | //ust// } |
1230 | //ust// } | |
59b161cd | 1231 | //ust// } |
c1f20530 PMF |
1232 | //ust// clear_thread_flag(TIF_MARKER_PENDING); |
1233 | //ust// mutex_unlock(¤t->group_leader->user_markers_mutex); | |
59b161cd PMF |
1234 | //ust// mutex_unlock(&markers_mutex); |
1235 | //ust// } | |
68c1021b | 1236 | |
68c1021b PMF |
1237 | /* |
1238 | * Called at process exit and upon do_execve(). | |
1239 | * We assume that when the leader exits, no more references can be done to the | |
1240 | * leader structure by the other threads. | |
1241 | */ | |
1242 | void exit_user_markers(struct task_struct *p) | |
1243 | { | |
1244 | struct user_marker *umark; | |
1245 | struct hlist_node *pos, *n; | |
1246 | ||
1247 | if (thread_group_leader(p)) { | |
1248 | mutex_lock(&markers_mutex); | |
1249 | mutex_lock(&p->user_markers_mutex); | |
1250 | hlist_for_each_entry_safe(umark, pos, n, &p->user_markers, | |
1251 | hlist) | |
909bc43f | 1252 | free(umark); |
68c1021b PMF |
1253 | INIT_HLIST_HEAD(&p->user_markers); |
1254 | p->user_markers_sequence++; | |
1255 | mutex_unlock(&p->user_markers_mutex); | |
1256 | mutex_unlock(&markers_mutex); | |
1257 | } | |
1258 | } | |
1259 | ||
1260 | int is_marker_enabled(const char *channel, const char *name) | |
1261 | { | |
1262 | struct marker_entry *entry; | |
1263 | ||
1264 | mutex_lock(&markers_mutex); | |
1265 | entry = get_marker(channel, name); | |
1266 | mutex_unlock(&markers_mutex); | |
1267 | ||
1268 | return entry && !!entry->refcount; | |
1269 | } | |
9c67dc50 | 1270 | //ust// #endif |
68c1021b PMF |
1271 | |
1272 | int marker_module_notify(struct notifier_block *self, | |
1273 | unsigned long val, void *data) | |
1274 | { | |
1275 | struct module *mod = data; | |
1276 | ||
1277 | switch (val) { | |
1278 | case MODULE_STATE_COMING: | |
1279 | marker_update_probe_range(mod->markers, | |
1280 | mod->markers + mod->num_markers); | |
1281 | break; | |
1282 | case MODULE_STATE_GOING: | |
1283 | marker_update_probe_range(mod->markers, | |
1284 | mod->markers + mod->num_markers); | |
1285 | break; | |
1286 | } | |
1287 | return 0; | |
1288 | } | |
1289 | ||
1290 | struct notifier_block marker_module_nb = { | |
1291 | .notifier_call = marker_module_notify, | |
1292 | .priority = 0, | |
1293 | }; | |
1294 | ||
59b161cd PMF |
1295 | //ust// static int init_markers(void) |
1296 | //ust// { | |
1297 | //ust// return register_module_notifier(&marker_module_nb); | |
1298 | //ust// } | |
1299 | //ust// __initcall(init_markers); | |
1300 | /* TODO: call marker_module_nb() when a library is linked at runtime (dlopen)? */ | |
68c1021b PMF |
1301 | |
1302 | #endif /* CONFIG_MODULES */ | |
1303 | ||
b73a4c47 | 1304 | void ltt_dump_marker_state(struct ust_trace *trace) |
9c67dc50 | 1305 | { |
48454c95 | 1306 | struct marker_entry *entry; |
9c67dc50 | 1307 | struct ltt_probe_private_data call_data; |
48454c95 PMF |
1308 | struct hlist_head *head; |
1309 | struct hlist_node *node; | |
1310 | unsigned int i; | |
9c67dc50 | 1311 | |
48454c95 | 1312 | mutex_lock(&markers_mutex); |
9c67dc50 PMF |
1313 | call_data.trace = trace; |
1314 | call_data.serializer = NULL; | |
1315 | ||
48454c95 PMF |
1316 | for (i = 0; i < MARKER_TABLE_SIZE; i++) { |
1317 | head = &marker_table[i]; | |
1318 | hlist_for_each_entry(entry, node, head, hlist) { | |
1319 | __trace_mark(0, metadata, core_marker_id, | |
9c67dc50 | 1320 | &call_data, |
48454c95 PMF |
1321 | "channel %s name %s event_id %hu " |
1322 | "int #1u%zu long #1u%zu pointer #1u%zu " | |
1323 | "size_t #1u%zu alignment #1u%u", | |
1324 | entry->channel, | |
1325 | entry->name, | |
1326 | entry->event_id, | |
1327 | sizeof(int), sizeof(long), | |
1328 | sizeof(void *), sizeof(size_t), | |
1329 | ltt_get_alignment()); | |
1330 | if (entry->format) | |
1331 | __trace_mark(0, metadata, | |
1332 | core_marker_format, | |
1333 | &call_data, | |
1334 | "channel %s name %s format %s", | |
1335 | entry->channel, | |
1336 | entry->name, | |
1337 | entry->format); | |
1338 | } | |
9c67dc50 | 1339 | } |
48454c95 | 1340 | mutex_unlock(&markers_mutex); |
9c67dc50 | 1341 | } |
59b161cd | 1342 | //ust// EXPORT_SYMBOL_GPL(ltt_dump_marker_state); |
98963de4 | 1343 | |
20b37a31 PMF |
1344 | static void (*new_marker_cb)(struct marker *) = NULL; |
1345 | ||
1346 | void marker_set_new_marker_cb(void (*cb)(struct marker *)) | |
1347 | { | |
1348 | new_marker_cb = cb; | |
1349 | } | |
1350 | ||
1351 | static void new_markers(struct marker *start, struct marker *end) | |
1352 | { | |
1353 | if(new_marker_cb) { | |
1354 | struct marker *m; | |
1355 | for(m=start; m < end; m++) { | |
1356 | new_marker_cb(m); | |
1357 | } | |
1358 | } | |
1359 | } | |
1360 | ||
bf961c7e | 1361 | int marker_register_lib(struct marker *markers_start, int markers_count) |
98963de4 PMF |
1362 | { |
1363 | struct lib *pl; | |
1364 | ||
1365 | pl = (struct lib *) malloc(sizeof(struct lib)); | |
1366 | ||
1367 | pl->markers_start = markers_start; | |
1368 | pl->markers_count = markers_count; | |
1369 | ||
0b5207fa PMF |
1370 | /* FIXME: maybe protect this with its own mutex? */ |
1371 | lock_markers(); | |
98963de4 | 1372 | list_add(&pl->list, &libs); |
0b5207fa | 1373 | unlock_markers(); |
98963de4 | 1374 | |
20b37a31 PMF |
1375 | new_markers(markers_start, markers_start + markers_count); |
1376 | ||
4db647c5 PMF |
1377 | /* FIXME: update just the loaded lib */ |
1378 | lib_update_markers(); | |
1379 | ||
1c184644 | 1380 | DBG("just registered a markers section from %p and having %d markers", markers_start, markers_count); |
98963de4 PMF |
1381 | |
1382 | return 0; | |
1383 | } | |
c463904d | 1384 | |
0b5207fa PMF |
1385 | int marker_unregister_lib(struct marker *markers_start, int markers_count) |
1386 | { | |
1387 | /*FIXME: implement; but before implementing, marker_register_lib must | |
1388 | have appropriate locking. */ | |
1389 | ||
1390 | return 0; | |
1391 | } | |
1392 | ||
4db647c5 PMF |
1393 | static int initialized = 0; |
1394 | ||
1395 | void __attribute__((constructor)) init_markers(void) | |
c463904d | 1396 | { |
4db647c5 | 1397 | if(!initialized) { |
bf961c7e | 1398 | marker_register_lib(__start___markers, (((long)__stop___markers)-((long)__start___markers))/sizeof(struct marker)); |
3ea1e2fc | 1399 | //DBG("markers_start: %p, markers_stop: %p\n", __start___markers, __stop___markers); |
4db647c5 PMF |
1400 | initialized = 1; |
1401 | } | |
c463904d | 1402 | } |