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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 PMF |
18 | //ust// #include <linux/module.h> |
19 | //ust// #include <linux/mutex.h> | |
20 | //ust// #include <linux/types.h> | |
b4512257 PMF |
21 | //#include "jhash.h" |
22 | //#include "list.h" | |
23 | //#include "rcupdate.h" | |
59b161cd PMF |
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 | ||
769d0157 | 33 | #define _LGPL_SOURCE |
b7ea1a1c | 34 | #include <urcu-bp.h> |
769d0157 | 35 | |
fbca6b62 | 36 | #include <ust/kernelcompat.h> |
769d0157 | 37 | |
93d0f2ea | 38 | #include <ust/marker.h> |
59b161cd PMF |
39 | #include "usterr.h" |
40 | #include "channels.h" | |
41 | #include "tracercore.h" | |
c93858f1 | 42 | #include "tracer.h" |
68c1021b | 43 | |
636ca5d6 PMF |
44 | __thread long ust_reg_stack[500]; |
45 | volatile __thread long *ust_reg_stack_ptr = (long *) 0; | |
46 | ||
c463904d PMF |
47 | extern struct marker __start___markers[] __attribute__((visibility("hidden"))); |
48 | extern struct marker __stop___markers[] __attribute__((visibility("hidden"))); | |
defa46a7 | 49 | |
68c1021b PMF |
50 | /* Set to 1 to enable marker debug output */ |
51 | static const int marker_debug; | |
52 | ||
53 | /* | |
54 | * markers_mutex nests inside module_mutex. Markers mutex protects the builtin | |
55 | * and module markers and the hash table. | |
56 | */ | |
57 | static DEFINE_MUTEX(markers_mutex); | |
58 | ||
772030fe PMF |
59 | static LIST_HEAD(libs); |
60 | ||
61 | ||
68c1021b PMF |
62 | void lock_markers(void) |
63 | { | |
64 | mutex_lock(&markers_mutex); | |
65 | } | |
66 | ||
67 | void unlock_markers(void) | |
68 | { | |
69 | mutex_unlock(&markers_mutex); | |
70 | } | |
71 | ||
72 | /* | |
73 | * Marker hash table, containing the active markers. | |
74 | * Protected by module_mutex. | |
75 | */ | |
76 | #define MARKER_HASH_BITS 6 | |
77 | #define MARKER_TABLE_SIZE (1 << MARKER_HASH_BITS) | |
78 | static struct hlist_head marker_table[MARKER_TABLE_SIZE]; | |
79 | ||
80 | /* | |
81 | * Note about RCU : | |
82 | * It is used to make sure every handler has finished using its private data | |
83 | * between two consecutive operation (add or remove) on a given marker. It is | |
84 | * also used to delay the free of multiple probes array until a quiescent state | |
85 | * is reached. | |
86 | * marker entries modifications are protected by the markers_mutex. | |
87 | */ | |
88 | struct marker_entry { | |
89 | struct hlist_node hlist; | |
90 | char *format; | |
91 | char *name; | |
92 | /* Probe wrapper */ | |
75667d04 | 93 | void (*call)(const struct marker *mdata, void *call_private, struct registers *regs, ...); |
68c1021b PMF |
94 | struct marker_probe_closure single; |
95 | struct marker_probe_closure *multi; | |
96 | int refcount; /* Number of times armed. 0 if disarmed. */ | |
97 | struct rcu_head rcu; | |
98 | void *oldptr; | |
99 | int rcu_pending; | |
100 | u16 channel_id; | |
101 | u16 event_id; | |
102 | unsigned char ptype:1; | |
103 | unsigned char format_allocated:1; | |
104 | char channel[0]; /* Contains channel'\0'name'\0'format'\0' */ | |
105 | }; | |
106 | ||
107 | #ifdef CONFIG_MARKERS_USERSPACE | |
108 | static void marker_update_processes(void); | |
109 | #else | |
110 | static void marker_update_processes(void) | |
111 | { | |
112 | } | |
113 | #endif | |
114 | ||
115 | /** | |
116 | * __mark_empty_function - Empty probe callback | |
117 | * @mdata: marker data | |
118 | * @probe_private: probe private data | |
119 | * @call_private: call site private data | |
120 | * @fmt: format string | |
121 | * @...: variable argument list | |
122 | * | |
123 | * Empty callback provided as a probe to the markers. By providing this to a | |
124 | * disabled marker, we make sure the execution flow is always valid even | |
125 | * though the function pointer change and the marker enabling are two distinct | |
126 | * operations that modifies the execution flow of preemptible code. | |
127 | */ | |
128 | notrace void __mark_empty_function(const struct marker *mdata, | |
75667d04 | 129 | void *probe_private, struct registers *regs, void *call_private, const char *fmt, va_list *args) |
68c1021b PMF |
130 | { |
131 | } | |
59b161cd | 132 | //ust// EXPORT_SYMBOL_GPL(__mark_empty_function); |
68c1021b PMF |
133 | |
134 | /* | |
135 | * marker_probe_cb Callback that prepares the variable argument list for probes. | |
136 | * @mdata: pointer of type struct marker | |
137 | * @call_private: caller site private data | |
138 | * @...: Variable argument list. | |
139 | * | |
140 | * Since we do not use "typical" pointer based RCU in the 1 argument case, we | |
141 | * need to put a full smp_rmb() in this branch. This is why we do not use | |
142 | * rcu_dereference() for the pointer read. | |
143 | */ | |
144 | notrace void marker_probe_cb(const struct marker *mdata, | |
75667d04 | 145 | void *call_private, struct registers *regs, ...) |
68c1021b PMF |
146 | { |
147 | va_list args; | |
148 | char ptype; | |
149 | ||
150 | /* | |
151 | * rcu_read_lock_sched does two things : disabling preemption to make | |
152 | * sure the teardown of the callbacks can be done correctly when they | |
153 | * are in modules and they insure RCU read coherency. | |
154 | */ | |
59b161cd | 155 | //ust// rcu_read_lock_sched_notrace(); |
68c1021b PMF |
156 | ptype = mdata->ptype; |
157 | if (likely(!ptype)) { | |
158 | marker_probe_func *func; | |
159 | /* Must read the ptype before ptr. They are not data dependant, | |
160 | * so we put an explicit smp_rmb() here. */ | |
161 | smp_rmb(); | |
162 | func = mdata->single.func; | |
163 | /* Must read the ptr before private data. They are not data | |
164 | * dependant, so we put an explicit smp_rmb() here. */ | |
165 | smp_rmb(); | |
75667d04 PMF |
166 | va_start(args, regs); |
167 | func(mdata, mdata->single.probe_private, regs, call_private, | |
68c1021b PMF |
168 | mdata->format, &args); |
169 | va_end(args); | |
170 | } else { | |
171 | struct marker_probe_closure *multi; | |
172 | int i; | |
173 | /* | |
174 | * Read mdata->ptype before mdata->multi. | |
175 | */ | |
176 | smp_rmb(); | |
177 | multi = mdata->multi; | |
178 | /* | |
179 | * multi points to an array, therefore accessing the array | |
180 | * depends on reading multi. However, even in this case, | |
181 | * we must insure that the pointer is read _before_ the array | |
182 | * data. Same as rcu_dereference, but we need a full smp_rmb() | |
183 | * in the fast path, so put the explicit barrier here. | |
184 | */ | |
185 | smp_read_barrier_depends(); | |
186 | for (i = 0; multi[i].func; i++) { | |
75667d04 | 187 | va_start(args, regs); |
68c1021b | 188 | multi[i].func(mdata, multi[i].probe_private, |
75667d04 | 189 | regs, call_private, mdata->format, &args); |
68c1021b PMF |
190 | va_end(args); |
191 | } | |
192 | } | |
59b161cd | 193 | //ust// rcu_read_unlock_sched_notrace(); |
68c1021b | 194 | } |
59b161cd | 195 | //ust// EXPORT_SYMBOL_GPL(marker_probe_cb); |
68c1021b PMF |
196 | |
197 | /* | |
198 | * marker_probe_cb Callback that does not prepare the variable argument list. | |
199 | * @mdata: pointer of type struct marker | |
200 | * @call_private: caller site private data | |
201 | * @...: Variable argument list. | |
202 | * | |
203 | * Should be connected to markers "MARK_NOARGS". | |
204 | */ | |
205 | static notrace void marker_probe_cb_noarg(const struct marker *mdata, | |
75667d04 | 206 | void *call_private, struct registers *regs, ...) |
68c1021b PMF |
207 | { |
208 | va_list args; /* not initialized */ | |
209 | char ptype; | |
210 | ||
59b161cd | 211 | //ust// rcu_read_lock_sched_notrace(); |
68c1021b PMF |
212 | ptype = mdata->ptype; |
213 | if (likely(!ptype)) { | |
214 | marker_probe_func *func; | |
215 | /* Must read the ptype before ptr. They are not data dependant, | |
216 | * so we put an explicit smp_rmb() here. */ | |
217 | smp_rmb(); | |
218 | func = mdata->single.func; | |
219 | /* Must read the ptr before private data. They are not data | |
220 | * dependant, so we put an explicit smp_rmb() here. */ | |
221 | smp_rmb(); | |
75667d04 | 222 | func(mdata, mdata->single.probe_private, regs, call_private, |
68c1021b PMF |
223 | mdata->format, &args); |
224 | } else { | |
225 | struct marker_probe_closure *multi; | |
226 | int i; | |
227 | /* | |
228 | * Read mdata->ptype before mdata->multi. | |
229 | */ | |
230 | smp_rmb(); | |
231 | multi = mdata->multi; | |
232 | /* | |
233 | * multi points to an array, therefore accessing the array | |
234 | * depends on reading multi. However, even in this case, | |
235 | * we must insure that the pointer is read _before_ the array | |
236 | * data. Same as rcu_dereference, but we need a full smp_rmb() | |
237 | * in the fast path, so put the explicit barrier here. | |
238 | */ | |
239 | smp_read_barrier_depends(); | |
240 | for (i = 0; multi[i].func; i++) | |
75667d04 | 241 | multi[i].func(mdata, multi[i].probe_private, regs, |
68c1021b PMF |
242 | call_private, mdata->format, &args); |
243 | } | |
59b161cd | 244 | //ust// rcu_read_unlock_sched_notrace(); |
68c1021b PMF |
245 | } |
246 | ||
247 | static void free_old_closure(struct rcu_head *head) | |
248 | { | |
249 | struct marker_entry *entry = container_of(head, | |
250 | struct marker_entry, rcu); | |
251 | kfree(entry->oldptr); | |
252 | /* Make sure we free the data before setting the pending flag to 0 */ | |
253 | smp_wmb(); | |
254 | entry->rcu_pending = 0; | |
255 | } | |
256 | ||
257 | static void debug_print_probes(struct marker_entry *entry) | |
258 | { | |
259 | int i; | |
260 | ||
261 | if (!marker_debug) | |
262 | return; | |
263 | ||
264 | if (!entry->ptype) { | |
c1f20530 | 265 | DBG("Single probe : %p %p", |
68c1021b PMF |
266 | entry->single.func, |
267 | entry->single.probe_private); | |
268 | } else { | |
269 | for (i = 0; entry->multi[i].func; i++) | |
c1f20530 | 270 | DBG("Multi probe %d : %p %p", i, |
68c1021b PMF |
271 | entry->multi[i].func, |
272 | entry->multi[i].probe_private); | |
273 | } | |
274 | } | |
275 | ||
276 | static struct marker_probe_closure * | |
277 | marker_entry_add_probe(struct marker_entry *entry, | |
278 | marker_probe_func *probe, void *probe_private) | |
279 | { | |
280 | int nr_probes = 0; | |
281 | struct marker_probe_closure *old, *new; | |
282 | ||
283 | WARN_ON(!probe); | |
284 | ||
285 | debug_print_probes(entry); | |
286 | old = entry->multi; | |
287 | if (!entry->ptype) { | |
288 | if (entry->single.func == probe && | |
289 | entry->single.probe_private == probe_private) | |
290 | return ERR_PTR(-EBUSY); | |
291 | if (entry->single.func == __mark_empty_function) { | |
292 | /* 0 -> 1 probes */ | |
293 | entry->single.func = probe; | |
294 | entry->single.probe_private = probe_private; | |
295 | entry->refcount = 1; | |
296 | entry->ptype = 0; | |
297 | debug_print_probes(entry); | |
298 | return NULL; | |
299 | } else { | |
300 | /* 1 -> 2 probes */ | |
301 | nr_probes = 1; | |
302 | old = NULL; | |
303 | } | |
304 | } else { | |
305 | /* (N -> N+1), (N != 0, 1) probes */ | |
306 | for (nr_probes = 0; old[nr_probes].func; nr_probes++) | |
307 | if (old[nr_probes].func == probe | |
308 | && old[nr_probes].probe_private | |
309 | == probe_private) | |
310 | return ERR_PTR(-EBUSY); | |
311 | } | |
312 | /* + 2 : one for new probe, one for NULL func */ | |
313 | new = kzalloc((nr_probes + 2) * sizeof(struct marker_probe_closure), | |
314 | GFP_KERNEL); | |
315 | if (new == NULL) | |
316 | return ERR_PTR(-ENOMEM); | |
317 | if (!old) | |
318 | new[0] = entry->single; | |
319 | else | |
320 | memcpy(new, old, | |
321 | nr_probes * sizeof(struct marker_probe_closure)); | |
322 | new[nr_probes].func = probe; | |
323 | new[nr_probes].probe_private = probe_private; | |
324 | entry->refcount = nr_probes + 1; | |
325 | entry->multi = new; | |
326 | entry->ptype = 1; | |
327 | debug_print_probes(entry); | |
328 | return old; | |
329 | } | |
330 | ||
331 | static struct marker_probe_closure * | |
332 | marker_entry_remove_probe(struct marker_entry *entry, | |
333 | marker_probe_func *probe, void *probe_private) | |
334 | { | |
335 | int nr_probes = 0, nr_del = 0, i; | |
336 | struct marker_probe_closure *old, *new; | |
337 | ||
338 | old = entry->multi; | |
339 | ||
340 | debug_print_probes(entry); | |
341 | if (!entry->ptype) { | |
342 | /* 0 -> N is an error */ | |
343 | WARN_ON(entry->single.func == __mark_empty_function); | |
344 | /* 1 -> 0 probes */ | |
345 | WARN_ON(probe && entry->single.func != probe); | |
346 | WARN_ON(entry->single.probe_private != probe_private); | |
347 | entry->single.func = __mark_empty_function; | |
348 | entry->refcount = 0; | |
349 | entry->ptype = 0; | |
350 | debug_print_probes(entry); | |
351 | return NULL; | |
352 | } else { | |
353 | /* (N -> M), (N > 1, M >= 0) probes */ | |
354 | for (nr_probes = 0; old[nr_probes].func; nr_probes++) { | |
355 | if ((!probe || old[nr_probes].func == probe) | |
356 | && old[nr_probes].probe_private | |
357 | == probe_private) | |
358 | nr_del++; | |
359 | } | |
360 | } | |
361 | ||
362 | if (nr_probes - nr_del == 0) { | |
363 | /* N -> 0, (N > 1) */ | |
364 | entry->single.func = __mark_empty_function; | |
365 | entry->refcount = 0; | |
366 | entry->ptype = 0; | |
367 | } else if (nr_probes - nr_del == 1) { | |
368 | /* N -> 1, (N > 1) */ | |
369 | for (i = 0; old[i].func; i++) | |
370 | if ((probe && old[i].func != probe) || | |
371 | old[i].probe_private != probe_private) | |
372 | entry->single = old[i]; | |
373 | entry->refcount = 1; | |
374 | entry->ptype = 0; | |
375 | } else { | |
376 | int j = 0; | |
377 | /* N -> M, (N > 1, M > 1) */ | |
378 | /* + 1 for NULL */ | |
379 | new = kzalloc((nr_probes - nr_del + 1) | |
380 | * sizeof(struct marker_probe_closure), GFP_KERNEL); | |
381 | if (new == NULL) | |
382 | return ERR_PTR(-ENOMEM); | |
383 | for (i = 0; old[i].func; i++) | |
384 | if ((probe && old[i].func != probe) || | |
385 | old[i].probe_private != probe_private) | |
386 | new[j++] = old[i]; | |
387 | entry->refcount = nr_probes - nr_del; | |
388 | entry->ptype = 1; | |
389 | entry->multi = new; | |
390 | } | |
391 | debug_print_probes(entry); | |
392 | return old; | |
393 | } | |
394 | ||
395 | /* | |
396 | * Get marker if the marker is present in the marker hash table. | |
397 | * Must be called with markers_mutex held. | |
398 | * Returns NULL if not present. | |
399 | */ | |
400 | static struct marker_entry *get_marker(const char *channel, const char *name) | |
401 | { | |
402 | struct hlist_head *head; | |
403 | struct hlist_node *node; | |
404 | struct marker_entry *e; | |
405 | size_t channel_len = strlen(channel) + 1; | |
406 | size_t name_len = strlen(name) + 1; | |
407 | u32 hash; | |
408 | ||
409 | hash = jhash(channel, channel_len-1, 0) ^ jhash(name, name_len-1, 0); | |
410 | head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; | |
411 | hlist_for_each_entry(e, node, head, hlist) { | |
412 | if (!strcmp(channel, e->channel) && !strcmp(name, e->name)) | |
413 | return e; | |
414 | } | |
415 | return NULL; | |
416 | } | |
417 | ||
418 | /* | |
419 | * Add the marker to the marker hash table. Must be called with markers_mutex | |
420 | * held. | |
421 | */ | |
422 | static struct marker_entry *add_marker(const char *channel, const char *name, | |
423 | const char *format) | |
424 | { | |
425 | struct hlist_head *head; | |
426 | struct hlist_node *node; | |
427 | struct marker_entry *e; | |
428 | size_t channel_len = strlen(channel) + 1; | |
429 | size_t name_len = strlen(name) + 1; | |
430 | size_t format_len = 0; | |
431 | u32 hash; | |
432 | ||
433 | hash = jhash(channel, channel_len-1, 0) ^ jhash(name, name_len-1, 0); | |
434 | if (format) | |
435 | format_len = strlen(format) + 1; | |
436 | head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; | |
437 | hlist_for_each_entry(e, node, head, hlist) { | |
438 | if (!strcmp(channel, e->channel) && !strcmp(name, e->name)) { | |
c1f20530 | 439 | DBG("Marker %s.%s busy", channel, name); |
68c1021b PMF |
440 | return ERR_PTR(-EBUSY); /* Already there */ |
441 | } | |
442 | } | |
443 | /* | |
444 | * Using kmalloc here to allocate a variable length element. Could | |
445 | * cause some memory fragmentation if overused. | |
446 | */ | |
447 | e = kmalloc(sizeof(struct marker_entry) | |
448 | + channel_len + name_len + format_len, | |
449 | GFP_KERNEL); | |
450 | if (!e) | |
451 | return ERR_PTR(-ENOMEM); | |
452 | memcpy(e->channel, channel, channel_len); | |
453 | e->name = &e->channel[channel_len]; | |
454 | memcpy(e->name, name, name_len); | |
455 | if (format) { | |
456 | e->format = &e->name[channel_len + name_len]; | |
457 | memcpy(e->format, format, format_len); | |
458 | if (strcmp(e->format, MARK_NOARGS) == 0) | |
459 | e->call = marker_probe_cb_noarg; | |
460 | else | |
461 | e->call = marker_probe_cb; | |
462 | trace_mark(metadata, core_marker_format, | |
463 | "channel %s name %s format %s", | |
464 | e->channel, e->name, e->format); | |
465 | } else { | |
466 | e->format = NULL; | |
467 | e->call = marker_probe_cb; | |
468 | } | |
469 | e->single.func = __mark_empty_function; | |
470 | e->single.probe_private = NULL; | |
471 | e->multi = NULL; | |
472 | e->ptype = 0; | |
473 | e->format_allocated = 0; | |
474 | e->refcount = 0; | |
475 | e->rcu_pending = 0; | |
476 | hlist_add_head(&e->hlist, head); | |
477 | return e; | |
478 | } | |
479 | ||
480 | /* | |
481 | * Remove the marker from the marker hash table. Must be called with mutex_lock | |
482 | * held. | |
483 | */ | |
484 | static int remove_marker(const char *channel, const char *name) | |
485 | { | |
486 | struct hlist_head *head; | |
487 | struct hlist_node *node; | |
488 | struct marker_entry *e; | |
489 | int found = 0; | |
490 | size_t channel_len = strlen(channel) + 1; | |
491 | size_t name_len = strlen(name) + 1; | |
492 | u32 hash; | |
493 | int ret; | |
494 | ||
495 | hash = jhash(channel, channel_len-1, 0) ^ jhash(name, name_len-1, 0); | |
496 | head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; | |
497 | hlist_for_each_entry(e, node, head, hlist) { | |
498 | if (!strcmp(channel, e->channel) && !strcmp(name, e->name)) { | |
499 | found = 1; | |
500 | break; | |
501 | } | |
502 | } | |
503 | if (!found) | |
504 | return -ENOENT; | |
505 | if (e->single.func != __mark_empty_function) | |
506 | return -EBUSY; | |
507 | hlist_del(&e->hlist); | |
508 | if (e->format_allocated) | |
509 | kfree(e->format); | |
510 | ret = ltt_channels_unregister(e->channel); | |
511 | WARN_ON(ret); | |
512 | /* Make sure the call_rcu has been executed */ | |
6cb88bc0 PMF |
513 | //ust// if (e->rcu_pending) |
514 | //ust// rcu_barrier_sched(); | |
68c1021b PMF |
515 | kfree(e); |
516 | return 0; | |
517 | } | |
518 | ||
519 | /* | |
520 | * Set the mark_entry format to the format found in the element. | |
521 | */ | |
522 | static int marker_set_format(struct marker_entry *entry, const char *format) | |
523 | { | |
524 | entry->format = kstrdup(format, GFP_KERNEL); | |
525 | if (!entry->format) | |
526 | return -ENOMEM; | |
527 | entry->format_allocated = 1; | |
528 | ||
529 | trace_mark(metadata, core_marker_format, | |
530 | "channel %s name %s format %s", | |
531 | entry->channel, entry->name, entry->format); | |
532 | return 0; | |
533 | } | |
534 | ||
535 | /* | |
536 | * Sets the probe callback corresponding to one marker. | |
537 | */ | |
538 | static int set_marker(struct marker_entry *entry, struct marker *elem, | |
539 | int active) | |
540 | { | |
541 | int ret = 0; | |
542 | WARN_ON(strcmp(entry->name, elem->name) != 0); | |
543 | ||
544 | if (entry->format) { | |
545 | if (strcmp(entry->format, elem->format) != 0) { | |
c1f20530 | 546 | DBG("Format mismatch for probe %s (%s), marker (%s)", |
68c1021b PMF |
547 | entry->name, |
548 | entry->format, | |
549 | elem->format); | |
550 | return -EPERM; | |
551 | } | |
552 | } else { | |
553 | ret = marker_set_format(entry, elem->format); | |
554 | if (ret) | |
555 | return ret; | |
556 | } | |
557 | ||
558 | /* | |
559 | * probe_cb setup (statically known) is done here. It is | |
560 | * asynchronous with the rest of execution, therefore we only | |
561 | * pass from a "safe" callback (with argument) to an "unsafe" | |
562 | * callback (does not set arguments). | |
563 | */ | |
564 | elem->call = entry->call; | |
565 | elem->channel_id = entry->channel_id; | |
566 | elem->event_id = entry->event_id; | |
567 | /* | |
568 | * Sanity check : | |
569 | * We only update the single probe private data when the ptr is | |
570 | * set to a _non_ single probe! (0 -> 1 and N -> 1, N != 1) | |
571 | */ | |
572 | WARN_ON(elem->single.func != __mark_empty_function | |
573 | && elem->single.probe_private != entry->single.probe_private | |
574 | && !elem->ptype); | |
575 | elem->single.probe_private = entry->single.probe_private; | |
576 | /* | |
577 | * Make sure the private data is valid when we update the | |
578 | * single probe ptr. | |
579 | */ | |
580 | smp_wmb(); | |
581 | elem->single.func = entry->single.func; | |
582 | /* | |
583 | * We also make sure that the new probe callbacks array is consistent | |
584 | * before setting a pointer to it. | |
585 | */ | |
586 | rcu_assign_pointer(elem->multi, entry->multi); | |
587 | /* | |
588 | * Update the function or multi probe array pointer before setting the | |
589 | * ptype. | |
590 | */ | |
591 | smp_wmb(); | |
592 | elem->ptype = entry->ptype; | |
593 | ||
59b161cd PMF |
594 | //ust// if (elem->tp_name && (active ^ _imv_read(elem->state))) { |
595 | //ust// WARN_ON(!elem->tp_cb); | |
596 | //ust// /* | |
597 | //ust// * It is ok to directly call the probe registration because type | |
598 | //ust// * checking has been done in the __trace_mark_tp() macro. | |
599 | //ust// */ | |
600 | //ust// | |
601 | //ust// if (active) { | |
602 | //ust// /* | |
603 | //ust// * try_module_get should always succeed because we hold | |
604 | //ust// * markers_mutex to get the tp_cb address. | |
605 | //ust// */ | |
606 | //ust// ret = try_module_get(__module_text_address( | |
607 | //ust// (unsigned long)elem->tp_cb)); | |
608 | //ust// BUG_ON(!ret); | |
609 | //ust// ret = tracepoint_probe_register_noupdate( | |
610 | //ust// elem->tp_name, | |
611 | //ust// elem->tp_cb); | |
612 | //ust// } else { | |
613 | //ust// ret = tracepoint_probe_unregister_noupdate( | |
614 | //ust// elem->tp_name, | |
615 | //ust// elem->tp_cb); | |
616 | //ust// /* | |
617 | //ust// * tracepoint_probe_update_all() must be called | |
618 | //ust// * before the module containing tp_cb is unloaded. | |
619 | //ust// */ | |
620 | //ust// module_put(__module_text_address( | |
621 | //ust// (unsigned long)elem->tp_cb)); | |
622 | //ust// } | |
623 | //ust// } | |
68c1021b PMF |
624 | elem->state__imv = active; |
625 | ||
626 | return ret; | |
627 | } | |
628 | ||
629 | /* | |
630 | * Disable a marker and its probe callback. | |
631 | * Note: only waiting an RCU period after setting elem->call to the empty | |
632 | * function insures that the original callback is not used anymore. This insured | |
633 | * by rcu_read_lock_sched around the call site. | |
634 | */ | |
635 | static void disable_marker(struct marker *elem) | |
636 | { | |
772030fe PMF |
637 | //ust// int ret; |
638 | //ust// | |
639 | //ust// /* leave "call" as is. It is known statically. */ | |
59b161cd PMF |
640 | //ust// if (elem->tp_name && _imv_read(elem->state)) { |
641 | //ust// WARN_ON(!elem->tp_cb); | |
642 | //ust// /* | |
643 | //ust// * It is ok to directly call the probe registration because type | |
644 | //ust// * checking has been done in the __trace_mark_tp() macro. | |
645 | //ust// */ | |
646 | //ust// ret = tracepoint_probe_unregister_noupdate(elem->tp_name, | |
647 | //ust// elem->tp_cb); | |
648 | //ust// WARN_ON(ret); | |
649 | //ust// /* | |
650 | //ust// * tracepoint_probe_update_all() must be called | |
651 | //ust// * before the module containing tp_cb is unloaded. | |
652 | //ust// */ | |
653 | //ust// module_put(__module_text_address((unsigned long)elem->tp_cb)); | |
654 | //ust// } | |
68c1021b PMF |
655 | elem->state__imv = 0; |
656 | elem->single.func = __mark_empty_function; | |
657 | /* Update the function before setting the ptype */ | |
658 | smp_wmb(); | |
659 | elem->ptype = 0; /* single probe */ | |
660 | /* | |
661 | * Leave the private data and channel_id/event_id there, because removal | |
662 | * is racy and should be done only after an RCU period. These are never | |
663 | * used until the next initialization anyway. | |
664 | */ | |
665 | } | |
666 | ||
a5311005 PMF |
667 | /* |
668 | * is_marker_enabled - Check if a marker is enabled | |
669 | * @channel: channel name | |
670 | * @name: marker name | |
671 | * | |
672 | * Returns 1 if the marker is enabled, 0 if disabled. | |
673 | */ | |
674 | int is_marker_enabled(const char *channel, const char *name) | |
675 | { | |
676 | struct marker_entry *entry; | |
677 | ||
678 | mutex_lock(&markers_mutex); | |
679 | entry = get_marker(channel, name); | |
680 | mutex_unlock(&markers_mutex); | |
681 | ||
682 | return entry && !!entry->refcount; | |
683 | } | |
684 | ||
68c1021b PMF |
685 | /** |
686 | * marker_update_probe_range - Update a probe range | |
687 | * @begin: beginning of the range | |
688 | * @end: end of the range | |
689 | * | |
690 | * Updates the probe callback corresponding to a range of markers. | |
691 | */ | |
692 | void marker_update_probe_range(struct marker *begin, | |
693 | struct marker *end) | |
694 | { | |
695 | struct marker *iter; | |
696 | struct marker_entry *mark_entry; | |
697 | ||
698 | mutex_lock(&markers_mutex); | |
699 | for (iter = begin; iter < end; iter++) { | |
700 | mark_entry = get_marker(iter->channel, iter->name); | |
701 | if (mark_entry) { | |
702 | set_marker(mark_entry, iter, !!mark_entry->refcount); | |
703 | /* | |
704 | * ignore error, continue | |
705 | */ | |
4db647c5 PMF |
706 | |
707 | /* This is added for UST. We emit a core_marker_id event | |
708 | * for markers that are already registered to a probe | |
709 | * upon library load. Otherwise, no core_marker_id will | |
710 | * be generated for these markers. Is this the right thing | |
711 | * to do? | |
712 | */ | |
713 | trace_mark(metadata, core_marker_id, | |
714 | "channel %s name %s event_id %hu " | |
715 | "int #1u%zu long #1u%zu pointer #1u%zu " | |
716 | "size_t #1u%zu alignment #1u%u", | |
717 | iter->channel, iter->name, mark_entry->event_id, | |
718 | sizeof(int), sizeof(long), sizeof(void *), | |
719 | sizeof(size_t), ltt_get_alignment()); | |
68c1021b PMF |
720 | } else { |
721 | disable_marker(iter); | |
722 | } | |
723 | } | |
724 | mutex_unlock(&markers_mutex); | |
725 | } | |
726 | ||
772030fe PMF |
727 | static void lib_update_markers(void) |
728 | { | |
729 | struct lib *lib; | |
730 | ||
731 | /* FIXME: we should probably take a mutex here on libs */ | |
732 | //ust// mutex_lock(&module_mutex); | |
733 | list_for_each_entry(lib, &libs, list) | |
734 | marker_update_probe_range(lib->markers_start, | |
735 | lib->markers_start + lib->markers_count); | |
736 | //ust// mutex_unlock(&module_mutex); | |
737 | } | |
738 | ||
68c1021b PMF |
739 | /* |
740 | * Update probes, removing the faulty probes. | |
741 | * | |
742 | * Internal callback only changed before the first probe is connected to it. | |
743 | * Single probe private data can only be changed on 0 -> 1 and 2 -> 1 | |
744 | * transitions. All other transitions will leave the old private data valid. | |
745 | * This makes the non-atomicity of the callback/private data updates valid. | |
746 | * | |
747 | * "special case" updates : | |
748 | * 0 -> 1 callback | |
749 | * 1 -> 0 callback | |
750 | * 1 -> 2 callbacks | |
751 | * 2 -> 1 callbacks | |
752 | * Other updates all behave the same, just like the 2 -> 3 or 3 -> 2 updates. | |
753 | * Site effect : marker_set_format may delete the marker entry (creating a | |
754 | * replacement). | |
755 | */ | |
756 | static void marker_update_probes(void) | |
757 | { | |
758 | /* Core kernel markers */ | |
c463904d | 759 | //ust// marker_update_probe_range(__start___markers, __stop___markers); |
68c1021b | 760 | /* Markers in modules. */ |
59b161cd | 761 | //ust// module_update_markers(); |
c463904d | 762 | lib_update_markers(); |
b6bf28ec | 763 | //ust// tracepoint_probe_update_all(); |
68c1021b PMF |
764 | /* Update immediate values */ |
765 | core_imv_update(); | |
474d745f | 766 | //ust// module_imv_update(); /* FIXME: need to port for libs? */ |
68c1021b PMF |
767 | marker_update_processes(); |
768 | } | |
769 | ||
770 | /** | |
771 | * marker_probe_register - Connect a probe to a marker | |
772 | * @channel: marker channel | |
773 | * @name: marker name | |
774 | * @format: format string | |
775 | * @probe: probe handler | |
776 | * @probe_private: probe private data | |
777 | * | |
778 | * private data must be a valid allocated memory address, or NULL. | |
779 | * Returns 0 if ok, error value on error. | |
780 | * The probe address must at least be aligned on the architecture pointer size. | |
781 | */ | |
782 | int marker_probe_register(const char *channel, const char *name, | |
783 | const char *format, marker_probe_func *probe, | |
784 | void *probe_private) | |
785 | { | |
786 | struct marker_entry *entry; | |
787 | int ret = 0, ret_err; | |
788 | struct marker_probe_closure *old; | |
789 | int first_probe = 0; | |
790 | ||
791 | mutex_lock(&markers_mutex); | |
792 | entry = get_marker(channel, name); | |
793 | if (!entry) { | |
794 | first_probe = 1; | |
795 | entry = add_marker(channel, name, format); | |
796 | if (IS_ERR(entry)) | |
797 | ret = PTR_ERR(entry); | |
798 | if (ret) | |
799 | goto end; | |
800 | ret = ltt_channels_register(channel); | |
801 | if (ret) | |
802 | goto error_remove_marker; | |
803 | ret = ltt_channels_get_index_from_name(channel); | |
804 | if (ret < 0) | |
805 | goto error_unregister_channel; | |
806 | entry->channel_id = ret; | |
807 | ret = ltt_channels_get_event_id(channel, name); | |
808 | if (ret < 0) | |
809 | goto error_unregister_channel; | |
810 | entry->event_id = ret; | |
811 | ret = 0; | |
812 | trace_mark(metadata, core_marker_id, | |
813 | "channel %s name %s event_id %hu " | |
814 | "int #1u%zu long #1u%zu pointer #1u%zu " | |
815 | "size_t #1u%zu alignment #1u%u", | |
816 | channel, name, entry->event_id, | |
817 | sizeof(int), sizeof(long), sizeof(void *), | |
818 | sizeof(size_t), ltt_get_alignment()); | |
819 | } else if (format) { | |
820 | if (!entry->format) | |
821 | ret = marker_set_format(entry, format); | |
822 | else if (strcmp(entry->format, format)) | |
823 | ret = -EPERM; | |
824 | if (ret) | |
825 | goto end; | |
826 | } | |
827 | ||
828 | /* | |
829 | * If we detect that a call_rcu is pending for this marker, | |
830 | * make sure it's executed now. | |
831 | */ | |
6cb88bc0 PMF |
832 | //ust// if (entry->rcu_pending) |
833 | //ust// rcu_barrier_sched(); | |
68c1021b PMF |
834 | old = marker_entry_add_probe(entry, probe, probe_private); |
835 | if (IS_ERR(old)) { | |
836 | ret = PTR_ERR(old); | |
837 | if (first_probe) | |
838 | goto error_unregister_channel; | |
839 | else | |
840 | goto end; | |
841 | } | |
842 | mutex_unlock(&markers_mutex); | |
843 | ||
79e36890 | 844 | /* Activate marker if necessary */ |
68c1021b PMF |
845 | marker_update_probes(); |
846 | ||
847 | mutex_lock(&markers_mutex); | |
848 | entry = get_marker(channel, name); | |
849 | if (!entry) | |
850 | goto end; | |
6cb88bc0 PMF |
851 | //ust// if (entry->rcu_pending) |
852 | //ust// rcu_barrier_sched(); | |
68c1021b PMF |
853 | entry->oldptr = old; |
854 | entry->rcu_pending = 1; | |
855 | /* write rcu_pending before calling the RCU callback */ | |
856 | smp_wmb(); | |
6cb88bc0 PMF |
857 | //ust// call_rcu_sched(&entry->rcu, free_old_closure); |
858 | synchronize_rcu(); free_old_closure(&entry->rcu); | |
68c1021b PMF |
859 | goto end; |
860 | ||
861 | error_unregister_channel: | |
862 | ret_err = ltt_channels_unregister(channel); | |
863 | WARN_ON(ret_err); | |
864 | error_remove_marker: | |
865 | ret_err = remove_marker(channel, name); | |
866 | WARN_ON(ret_err); | |
867 | end: | |
868 | mutex_unlock(&markers_mutex); | |
869 | return ret; | |
870 | } | |
59b161cd | 871 | //ust// EXPORT_SYMBOL_GPL(marker_probe_register); |
68c1021b PMF |
872 | |
873 | /** | |
874 | * marker_probe_unregister - Disconnect a probe from a marker | |
875 | * @channel: marker channel | |
876 | * @name: marker name | |
877 | * @probe: probe function pointer | |
878 | * @probe_private: probe private data | |
879 | * | |
880 | * Returns the private data given to marker_probe_register, or an ERR_PTR(). | |
881 | * We do not need to call a synchronize_sched to make sure the probes have | |
882 | * finished running before doing a module unload, because the module unload | |
883 | * itself uses stop_machine(), which insures that every preempt disabled section | |
884 | * have finished. | |
885 | */ | |
886 | int marker_probe_unregister(const char *channel, const char *name, | |
887 | marker_probe_func *probe, void *probe_private) | |
888 | { | |
889 | struct marker_entry *entry; | |
890 | struct marker_probe_closure *old; | |
891 | int ret = -ENOENT; | |
892 | ||
893 | mutex_lock(&markers_mutex); | |
894 | entry = get_marker(channel, name); | |
895 | if (!entry) | |
896 | goto end; | |
6cb88bc0 PMF |
897 | //ust// if (entry->rcu_pending) |
898 | //ust// rcu_barrier_sched(); | |
68c1021b PMF |
899 | old = marker_entry_remove_probe(entry, probe, probe_private); |
900 | mutex_unlock(&markers_mutex); | |
901 | ||
902 | marker_update_probes(); | |
903 | ||
904 | mutex_lock(&markers_mutex); | |
905 | entry = get_marker(channel, name); | |
906 | if (!entry) | |
907 | goto end; | |
6cb88bc0 PMF |
908 | //ust// if (entry->rcu_pending) |
909 | //ust// rcu_barrier_sched(); | |
68c1021b PMF |
910 | entry->oldptr = old; |
911 | entry->rcu_pending = 1; | |
912 | /* write rcu_pending before calling the RCU callback */ | |
913 | smp_wmb(); | |
6cb88bc0 PMF |
914 | //ust// call_rcu_sched(&entry->rcu, free_old_closure); |
915 | synchronize_rcu(); free_old_closure(&entry->rcu); | |
68c1021b PMF |
916 | remove_marker(channel, name); /* Ignore busy error message */ |
917 | ret = 0; | |
918 | end: | |
919 | mutex_unlock(&markers_mutex); | |
920 | return ret; | |
921 | } | |
59b161cd | 922 | //ust// EXPORT_SYMBOL_GPL(marker_probe_unregister); |
68c1021b PMF |
923 | |
924 | static struct marker_entry * | |
925 | get_marker_from_private_data(marker_probe_func *probe, void *probe_private) | |
926 | { | |
927 | struct marker_entry *entry; | |
928 | unsigned int i; | |
929 | struct hlist_head *head; | |
930 | struct hlist_node *node; | |
931 | ||
932 | for (i = 0; i < MARKER_TABLE_SIZE; i++) { | |
933 | head = &marker_table[i]; | |
934 | hlist_for_each_entry(entry, node, head, hlist) { | |
935 | if (!entry->ptype) { | |
936 | if (entry->single.func == probe | |
937 | && entry->single.probe_private | |
938 | == probe_private) | |
939 | return entry; | |
940 | } else { | |
941 | struct marker_probe_closure *closure; | |
942 | closure = entry->multi; | |
943 | for (i = 0; closure[i].func; i++) { | |
944 | if (closure[i].func == probe && | |
945 | closure[i].probe_private | |
946 | == probe_private) | |
947 | return entry; | |
948 | } | |
949 | } | |
950 | } | |
951 | } | |
952 | return NULL; | |
953 | } | |
954 | ||
955 | /** | |
956 | * marker_probe_unregister_private_data - Disconnect a probe from a marker | |
957 | * @probe: probe function | |
958 | * @probe_private: probe private data | |
959 | * | |
960 | * Unregister a probe by providing the registered private data. | |
961 | * Only removes the first marker found in hash table. | |
962 | * Return 0 on success or error value. | |
963 | * We do not need to call a synchronize_sched to make sure the probes have | |
964 | * finished running before doing a module unload, because the module unload | |
965 | * itself uses stop_machine(), which insures that every preempt disabled section | |
966 | * have finished. | |
967 | */ | |
968 | int marker_probe_unregister_private_data(marker_probe_func *probe, | |
969 | void *probe_private) | |
970 | { | |
971 | struct marker_entry *entry; | |
972 | int ret = 0; | |
973 | struct marker_probe_closure *old; | |
974 | const char *channel = NULL, *name = NULL; | |
975 | ||
976 | mutex_lock(&markers_mutex); | |
977 | entry = get_marker_from_private_data(probe, probe_private); | |
978 | if (!entry) { | |
979 | ret = -ENOENT; | |
980 | goto end; | |
981 | } | |
6cb88bc0 PMF |
982 | //ust// if (entry->rcu_pending) |
983 | //ust// rcu_barrier_sched(); | |
68c1021b PMF |
984 | old = marker_entry_remove_probe(entry, NULL, probe_private); |
985 | channel = kstrdup(entry->channel, GFP_KERNEL); | |
986 | name = kstrdup(entry->name, GFP_KERNEL); | |
987 | mutex_unlock(&markers_mutex); | |
988 | ||
989 | marker_update_probes(); | |
990 | ||
991 | mutex_lock(&markers_mutex); | |
992 | entry = get_marker(channel, name); | |
993 | if (!entry) | |
994 | goto end; | |
6cb88bc0 PMF |
995 | //ust// if (entry->rcu_pending) |
996 | //ust// rcu_barrier_sched(); | |
68c1021b PMF |
997 | entry->oldptr = old; |
998 | entry->rcu_pending = 1; | |
999 | /* write rcu_pending before calling the RCU callback */ | |
1000 | smp_wmb(); | |
6cb88bc0 PMF |
1001 | //ust// call_rcu_sched(&entry->rcu, free_old_closure); |
1002 | synchronize_rcu(); free_old_closure(&entry->rcu); | |
68c1021b PMF |
1003 | /* Ignore busy error message */ |
1004 | remove_marker(channel, name); | |
1005 | end: | |
1006 | mutex_unlock(&markers_mutex); | |
1007 | kfree(channel); | |
1008 | kfree(name); | |
1009 | return ret; | |
1010 | } | |
59b161cd | 1011 | //ust// EXPORT_SYMBOL_GPL(marker_probe_unregister_private_data); |
68c1021b PMF |
1012 | |
1013 | /** | |
1014 | * marker_get_private_data - Get a marker's probe private data | |
1015 | * @channel: marker channel | |
1016 | * @name: marker name | |
1017 | * @probe: probe to match | |
1018 | * @num: get the nth matching probe's private data | |
1019 | * | |
1020 | * Returns the nth private data pointer (starting from 0) matching, or an | |
1021 | * ERR_PTR. | |
1022 | * Returns the private data pointer, or an ERR_PTR. | |
1023 | * The private data pointer should _only_ be dereferenced if the caller is the | |
1024 | * owner of the data, or its content could vanish. This is mostly used to | |
1025 | * confirm that a caller is the owner of a registered probe. | |
1026 | */ | |
1027 | void *marker_get_private_data(const char *channel, const char *name, | |
1028 | marker_probe_func *probe, int num) | |
1029 | { | |
1030 | struct hlist_head *head; | |
1031 | struct hlist_node *node; | |
1032 | struct marker_entry *e; | |
1033 | size_t channel_len = strlen(channel) + 1; | |
1034 | size_t name_len = strlen(name) + 1; | |
1035 | int i; | |
1036 | u32 hash; | |
1037 | ||
1038 | hash = jhash(channel, channel_len-1, 0) ^ jhash(name, name_len-1, 0); | |
1039 | head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; | |
1040 | hlist_for_each_entry(e, node, head, hlist) { | |
1041 | if (!strcmp(channel, e->channel) && !strcmp(name, e->name)) { | |
1042 | if (!e->ptype) { | |
1043 | if (num == 0 && e->single.func == probe) | |
1044 | return e->single.probe_private; | |
1045 | } else { | |
1046 | struct marker_probe_closure *closure; | |
1047 | int match = 0; | |
1048 | closure = e->multi; | |
1049 | for (i = 0; closure[i].func; i++) { | |
1050 | if (closure[i].func != probe) | |
1051 | continue; | |
1052 | if (match++ == num) | |
1053 | return closure[i].probe_private; | |
1054 | } | |
1055 | } | |
1056 | break; | |
1057 | } | |
1058 | } | |
1059 | return ERR_PTR(-ENOENT); | |
1060 | } | |
59b161cd | 1061 | //ust// EXPORT_SYMBOL_GPL(marker_get_private_data); |
68c1021b PMF |
1062 | |
1063 | /** | |
1064 | * markers_compact_event_ids - Compact markers event IDs and reassign channels | |
1065 | * | |
1066 | * Called when no channel users are active by the channel infrastructure. | |
1067 | * Called with lock_markers() and channel mutex held. | |
1068 | */ | |
59b161cd PMF |
1069 | //ust// void markers_compact_event_ids(void) |
1070 | //ust// { | |
1071 | //ust// struct marker_entry *entry; | |
1072 | //ust// unsigned int i; | |
1073 | //ust// struct hlist_head *head; | |
1074 | //ust// struct hlist_node *node; | |
1075 | //ust// int ret; | |
1076 | //ust// | |
1077 | //ust// for (i = 0; i < MARKER_TABLE_SIZE; i++) { | |
1078 | //ust// head = &marker_table[i]; | |
1079 | //ust// hlist_for_each_entry(entry, node, head, hlist) { | |
1080 | //ust// ret = ltt_channels_get_index_from_name(entry->channel); | |
1081 | //ust// WARN_ON(ret < 0); | |
1082 | //ust// entry->channel_id = ret; | |
1083 | //ust// ret = _ltt_channels_get_event_id(entry->channel, | |
1084 | //ust// entry->name); | |
1085 | //ust// WARN_ON(ret < 0); | |
1086 | //ust// entry->event_id = ret; | |
1087 | //ust// } | |
1088 | //ust// } | |
1089 | //ust// } | |
68c1021b | 1090 | |
9c67dc50 | 1091 | //ust//#ifdef CONFIG_MODULES |
68c1021b | 1092 | |
772030fe PMF |
1093 | /* |
1094 | * Returns 0 if current not found. | |
1095 | * Returns 1 if current found. | |
1096 | */ | |
1097 | int lib_get_iter_markers(struct marker_iter *iter) | |
1098 | { | |
1099 | struct lib *iter_lib; | |
1100 | int found = 0; | |
1101 | ||
1102 | //ust// mutex_lock(&module_mutex); | |
1103 | list_for_each_entry(iter_lib, &libs, list) { | |
1104 | if (iter_lib < iter->lib) | |
1105 | continue; | |
1106 | else if (iter_lib > iter->lib) | |
1107 | iter->marker = NULL; | |
1108 | found = marker_get_iter_range(&iter->marker, | |
1109 | iter_lib->markers_start, | |
1110 | iter_lib->markers_start + iter_lib->markers_count); | |
1111 | if (found) { | |
1112 | iter->lib = iter_lib; | |
1113 | break; | |
1114 | } | |
1115 | } | |
1116 | //ust// mutex_unlock(&module_mutex); | |
1117 | return found; | |
1118 | } | |
1119 | ||
68c1021b PMF |
1120 | /** |
1121 | * marker_get_iter_range - Get a next marker iterator given a range. | |
1122 | * @marker: current markers (in), next marker (out) | |
1123 | * @begin: beginning of the range | |
1124 | * @end: end of the range | |
1125 | * | |
1126 | * Returns whether a next marker has been found (1) or not (0). | |
1127 | * Will return the first marker in the range if the input marker is NULL. | |
1128 | */ | |
1129 | int marker_get_iter_range(struct marker **marker, struct marker *begin, | |
1130 | struct marker *end) | |
1131 | { | |
1132 | if (!*marker && begin != end) { | |
1133 | *marker = begin; | |
1134 | return 1; | |
1135 | } | |
1136 | if (*marker >= begin && *marker < end) | |
1137 | return 1; | |
1138 | return 0; | |
1139 | } | |
59b161cd | 1140 | //ust// EXPORT_SYMBOL_GPL(marker_get_iter_range); |
68c1021b PMF |
1141 | |
1142 | static void marker_get_iter(struct marker_iter *iter) | |
1143 | { | |
1144 | int found = 0; | |
1145 | ||
1146 | /* Core kernel markers */ | |
98963de4 | 1147 | if (!iter->lib) { |
c463904d | 1148 | /* ust FIXME: how come we cannot disable the following line? we shouldn't need core stuff */ |
68c1021b PMF |
1149 | found = marker_get_iter_range(&iter->marker, |
1150 | __start___markers, __stop___markers); | |
1151 | if (found) | |
1152 | goto end; | |
1153 | } | |
1154 | /* Markers in modules. */ | |
98963de4 | 1155 | found = lib_get_iter_markers(iter); |
68c1021b PMF |
1156 | end: |
1157 | if (!found) | |
1158 | marker_iter_reset(iter); | |
1159 | } | |
1160 | ||
1161 | void marker_iter_start(struct marker_iter *iter) | |
1162 | { | |
1163 | marker_get_iter(iter); | |
1164 | } | |
59b161cd | 1165 | //ust// EXPORT_SYMBOL_GPL(marker_iter_start); |
68c1021b PMF |
1166 | |
1167 | void marker_iter_next(struct marker_iter *iter) | |
1168 | { | |
1169 | iter->marker++; | |
1170 | /* | |
1171 | * iter->marker may be invalid because we blindly incremented it. | |
1172 | * Make sure it is valid by marshalling on the markers, getting the | |
1173 | * markers from following modules if necessary. | |
1174 | */ | |
1175 | marker_get_iter(iter); | |
1176 | } | |
59b161cd | 1177 | //ust// EXPORT_SYMBOL_GPL(marker_iter_next); |
68c1021b PMF |
1178 | |
1179 | void marker_iter_stop(struct marker_iter *iter) | |
1180 | { | |
1181 | } | |
59b161cd | 1182 | //ust// EXPORT_SYMBOL_GPL(marker_iter_stop); |
68c1021b PMF |
1183 | |
1184 | void marker_iter_reset(struct marker_iter *iter) | |
1185 | { | |
98963de4 | 1186 | iter->lib = NULL; |
68c1021b PMF |
1187 | iter->marker = NULL; |
1188 | } | |
59b161cd | 1189 | //ust// EXPORT_SYMBOL_GPL(marker_iter_reset); |
68c1021b PMF |
1190 | |
1191 | #ifdef CONFIG_MARKERS_USERSPACE | |
1192 | /* | |
1193 | * must be called with current->user_markers_mutex held | |
1194 | */ | |
1195 | static void free_user_marker(char __user *state, struct hlist_head *head) | |
1196 | { | |
1197 | struct user_marker *umark; | |
1198 | struct hlist_node *pos, *n; | |
1199 | ||
1200 | hlist_for_each_entry_safe(umark, pos, n, head, hlist) { | |
1201 | if (umark->state == state) { | |
1202 | hlist_del(&umark->hlist); | |
1203 | kfree(umark); | |
1204 | } | |
1205 | } | |
1206 | } | |
1207 | ||
c1f20530 PMF |
1208 | /* |
1209 | * Update current process. | |
1210 | * Note that we have to wait a whole scheduler period before we are sure that | |
1211 | * every running userspace threads have their markers updated. | |
1212 | * (synchronize_sched() can be used to insure this). | |
1213 | */ | |
1214 | //ust// void marker_update_process(void) | |
59b161cd PMF |
1215 | //ust// { |
1216 | //ust// struct user_marker *umark; | |
c1f20530 | 1217 | //ust// struct hlist_node *pos; |
59b161cd | 1218 | //ust// struct marker_entry *entry; |
59b161cd | 1219 | //ust// |
c1f20530 PMF |
1220 | //ust// mutex_lock(&markers_mutex); |
1221 | //ust// mutex_lock(¤t->group_leader->user_markers_mutex); | |
1222 | //ust// if (strcmp(current->comm, "testprog") == 0) | |
1223 | //ust// DBG("do update pending for testprog"); | |
1224 | //ust// hlist_for_each_entry(umark, pos, | |
1225 | //ust// ¤t->group_leader->user_markers, hlist) { | |
1226 | //ust// DBG("Updating marker %s in %s", umark->name, current->comm); | |
59b161cd PMF |
1227 | //ust// entry = get_marker("userspace", umark->name); |
1228 | //ust// if (entry) { | |
1229 | //ust// if (entry->format && | |
1230 | //ust// strcmp(entry->format, umark->format) != 0) { | |
c1f20530 | 1231 | //ust// WARN("error, wrong format in process %s", |
59b161cd | 1232 | //ust// current->comm); |
c1f20530 | 1233 | //ust// break; |
59b161cd | 1234 | //ust// } |
c1f20530 PMF |
1235 | //ust// if (put_user(!!entry->refcount, umark->state)) { |
1236 | //ust// WARN("Marker in %s caused a fault", | |
1237 | //ust// current->comm); | |
1238 | //ust// break; | |
59b161cd | 1239 | //ust// } |
59b161cd | 1240 | //ust// } else { |
59b161cd | 1241 | //ust// if (put_user(0, umark->state)) { |
c1f20530 PMF |
1242 | //ust// WARN("Marker in %s caused a fault", current->comm); |
1243 | //ust// break; | |
59b161cd PMF |
1244 | //ust// } |
1245 | //ust// } | |
59b161cd | 1246 | //ust// } |
c1f20530 PMF |
1247 | //ust// clear_thread_flag(TIF_MARKER_PENDING); |
1248 | //ust// mutex_unlock(¤t->group_leader->user_markers_mutex); | |
59b161cd PMF |
1249 | //ust// mutex_unlock(&markers_mutex); |
1250 | //ust// } | |
68c1021b | 1251 | |
68c1021b PMF |
1252 | /* |
1253 | * Called at process exit and upon do_execve(). | |
1254 | * We assume that when the leader exits, no more references can be done to the | |
1255 | * leader structure by the other threads. | |
1256 | */ | |
1257 | void exit_user_markers(struct task_struct *p) | |
1258 | { | |
1259 | struct user_marker *umark; | |
1260 | struct hlist_node *pos, *n; | |
1261 | ||
1262 | if (thread_group_leader(p)) { | |
1263 | mutex_lock(&markers_mutex); | |
1264 | mutex_lock(&p->user_markers_mutex); | |
1265 | hlist_for_each_entry_safe(umark, pos, n, &p->user_markers, | |
1266 | hlist) | |
1267 | kfree(umark); | |
1268 | INIT_HLIST_HEAD(&p->user_markers); | |
1269 | p->user_markers_sequence++; | |
1270 | mutex_unlock(&p->user_markers_mutex); | |
1271 | mutex_unlock(&markers_mutex); | |
1272 | } | |
1273 | } | |
1274 | ||
1275 | int is_marker_enabled(const char *channel, const char *name) | |
1276 | { | |
1277 | struct marker_entry *entry; | |
1278 | ||
1279 | mutex_lock(&markers_mutex); | |
1280 | entry = get_marker(channel, name); | |
1281 | mutex_unlock(&markers_mutex); | |
1282 | ||
1283 | return entry && !!entry->refcount; | |
1284 | } | |
9c67dc50 | 1285 | //ust// #endif |
68c1021b PMF |
1286 | |
1287 | int marker_module_notify(struct notifier_block *self, | |
1288 | unsigned long val, void *data) | |
1289 | { | |
1290 | struct module *mod = data; | |
1291 | ||
1292 | switch (val) { | |
1293 | case MODULE_STATE_COMING: | |
1294 | marker_update_probe_range(mod->markers, | |
1295 | mod->markers + mod->num_markers); | |
1296 | break; | |
1297 | case MODULE_STATE_GOING: | |
1298 | marker_update_probe_range(mod->markers, | |
1299 | mod->markers + mod->num_markers); | |
1300 | break; | |
1301 | } | |
1302 | return 0; | |
1303 | } | |
1304 | ||
1305 | struct notifier_block marker_module_nb = { | |
1306 | .notifier_call = marker_module_notify, | |
1307 | .priority = 0, | |
1308 | }; | |
1309 | ||
59b161cd PMF |
1310 | //ust// static int init_markers(void) |
1311 | //ust// { | |
1312 | //ust// return register_module_notifier(&marker_module_nb); | |
1313 | //ust// } | |
1314 | //ust// __initcall(init_markers); | |
1315 | /* TODO: call marker_module_nb() when a library is linked at runtime (dlopen)? */ | |
68c1021b PMF |
1316 | |
1317 | #endif /* CONFIG_MODULES */ | |
1318 | ||
b73a4c47 | 1319 | void ltt_dump_marker_state(struct ust_trace *trace) |
9c67dc50 | 1320 | { |
48454c95 | 1321 | struct marker_entry *entry; |
9c67dc50 | 1322 | struct ltt_probe_private_data call_data; |
48454c95 PMF |
1323 | struct hlist_head *head; |
1324 | struct hlist_node *node; | |
1325 | unsigned int i; | |
9c67dc50 | 1326 | |
48454c95 | 1327 | mutex_lock(&markers_mutex); |
9c67dc50 PMF |
1328 | call_data.trace = trace; |
1329 | call_data.serializer = NULL; | |
1330 | ||
48454c95 PMF |
1331 | for (i = 0; i < MARKER_TABLE_SIZE; i++) { |
1332 | head = &marker_table[i]; | |
1333 | hlist_for_each_entry(entry, node, head, hlist) { | |
1334 | __trace_mark(0, metadata, core_marker_id, | |
9c67dc50 | 1335 | &call_data, |
48454c95 PMF |
1336 | "channel %s name %s event_id %hu " |
1337 | "int #1u%zu long #1u%zu pointer #1u%zu " | |
1338 | "size_t #1u%zu alignment #1u%u", | |
1339 | entry->channel, | |
1340 | entry->name, | |
1341 | entry->event_id, | |
1342 | sizeof(int), sizeof(long), | |
1343 | sizeof(void *), sizeof(size_t), | |
1344 | ltt_get_alignment()); | |
1345 | if (entry->format) | |
1346 | __trace_mark(0, metadata, | |
1347 | core_marker_format, | |
1348 | &call_data, | |
1349 | "channel %s name %s format %s", | |
1350 | entry->channel, | |
1351 | entry->name, | |
1352 | entry->format); | |
1353 | } | |
9c67dc50 | 1354 | } |
48454c95 | 1355 | mutex_unlock(&markers_mutex); |
9c67dc50 | 1356 | } |
59b161cd | 1357 | //ust// EXPORT_SYMBOL_GPL(ltt_dump_marker_state); |
98963de4 | 1358 | |
20b37a31 PMF |
1359 | static void (*new_marker_cb)(struct marker *) = NULL; |
1360 | ||
1361 | void marker_set_new_marker_cb(void (*cb)(struct marker *)) | |
1362 | { | |
1363 | new_marker_cb = cb; | |
1364 | } | |
1365 | ||
1366 | static void new_markers(struct marker *start, struct marker *end) | |
1367 | { | |
1368 | if(new_marker_cb) { | |
1369 | struct marker *m; | |
1370 | for(m=start; m < end; m++) { | |
1371 | new_marker_cb(m); | |
1372 | } | |
1373 | } | |
1374 | } | |
1375 | ||
bf961c7e | 1376 | int marker_register_lib(struct marker *markers_start, int markers_count) |
98963de4 PMF |
1377 | { |
1378 | struct lib *pl; | |
3ea1e2fc | 1379 | struct marker_addr *addr; |
98963de4 PMF |
1380 | |
1381 | pl = (struct lib *) malloc(sizeof(struct lib)); | |
1382 | ||
1383 | pl->markers_start = markers_start; | |
1384 | pl->markers_count = markers_count; | |
1385 | ||
0b5207fa PMF |
1386 | /* FIXME: maybe protect this with its own mutex? */ |
1387 | lock_markers(); | |
98963de4 | 1388 | list_add(&pl->list, &libs); |
0b5207fa | 1389 | unlock_markers(); |
98963de4 | 1390 | |
20b37a31 PMF |
1391 | new_markers(markers_start, markers_start + markers_count); |
1392 | ||
4db647c5 PMF |
1393 | /* FIXME: update just the loaded lib */ |
1394 | lib_update_markers(); | |
1395 | ||
1c184644 | 1396 | DBG("just registered a markers section from %p and having %d markers", markers_start, markers_count); |
98963de4 PMF |
1397 | |
1398 | return 0; | |
1399 | } | |
c463904d | 1400 | |
0b5207fa PMF |
1401 | int marker_unregister_lib(struct marker *markers_start, int markers_count) |
1402 | { | |
1403 | /*FIXME: implement; but before implementing, marker_register_lib must | |
1404 | have appropriate locking. */ | |
1405 | ||
1406 | return 0; | |
1407 | } | |
1408 | ||
4db647c5 PMF |
1409 | static int initialized = 0; |
1410 | ||
1411 | void __attribute__((constructor)) init_markers(void) | |
c463904d | 1412 | { |
4db647c5 | 1413 | if(!initialized) { |
bf961c7e | 1414 | marker_register_lib(__start___markers, (((long)__stop___markers)-((long)__start___markers))/sizeof(struct marker)); |
3ea1e2fc | 1415 | //DBG("markers_start: %p, markers_stop: %p\n", __start___markers, __stop___markers); |
4db647c5 PMF |
1416 | initialized = 1; |
1417 | } | |
c463904d | 1418 | } |