Commit | Line | Data |
---|---|---|
68c1021b PMF |
1 | /* |
2 | * Copyright (C) 2007 Mathieu Desnoyers | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, write to the Free Software | |
16 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
17 | */ | |
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 | ||
33 | #include "marker.h" | |
34 | #include "kernelcompat.h" | |
35 | #include "usterr.h" | |
36 | #include "channels.h" | |
37 | #include "tracercore.h" | |
9c67dc50 | 38 | #include "tracer.h" |
6cb88bc0 | 39 | #include "urcu.h" |
68c1021b | 40 | |
c463904d PMF |
41 | extern struct marker __start___markers[] __attribute__((visibility("hidden"))); |
42 | extern struct marker __stop___markers[] __attribute__((visibility("hidden"))); | |
68c1021b PMF |
43 | |
44 | /* Set to 1 to enable marker debug output */ | |
45 | static const int marker_debug; | |
46 | ||
47 | /* | |
48 | * markers_mutex nests inside module_mutex. Markers mutex protects the builtin | |
49 | * and module markers and the hash table. | |
50 | */ | |
51 | static DEFINE_MUTEX(markers_mutex); | |
52 | ||
53 | void lock_markers(void) | |
54 | { | |
55 | mutex_lock(&markers_mutex); | |
56 | } | |
57 | ||
58 | void unlock_markers(void) | |
59 | { | |
60 | mutex_unlock(&markers_mutex); | |
61 | } | |
62 | ||
63 | /* | |
64 | * Marker hash table, containing the active markers. | |
65 | * Protected by module_mutex. | |
66 | */ | |
67 | #define MARKER_HASH_BITS 6 | |
68 | #define MARKER_TABLE_SIZE (1 << MARKER_HASH_BITS) | |
69 | static struct hlist_head marker_table[MARKER_TABLE_SIZE]; | |
70 | ||
71 | /* | |
72 | * Note about RCU : | |
73 | * It is used to make sure every handler has finished using its private data | |
74 | * between two consecutive operation (add or remove) on a given marker. It is | |
75 | * also used to delay the free of multiple probes array until a quiescent state | |
76 | * is reached. | |
77 | * marker entries modifications are protected by the markers_mutex. | |
78 | */ | |
79 | struct marker_entry { | |
80 | struct hlist_node hlist; | |
81 | char *format; | |
82 | char *name; | |
83 | /* Probe wrapper */ | |
84 | void (*call)(const struct marker *mdata, void *call_private, ...); | |
85 | struct marker_probe_closure single; | |
86 | struct marker_probe_closure *multi; | |
87 | int refcount; /* Number of times armed. 0 if disarmed. */ | |
88 | struct rcu_head rcu; | |
89 | void *oldptr; | |
90 | int rcu_pending; | |
91 | u16 channel_id; | |
92 | u16 event_id; | |
93 | unsigned char ptype:1; | |
94 | unsigned char format_allocated:1; | |
95 | char channel[0]; /* Contains channel'\0'name'\0'format'\0' */ | |
96 | }; | |
97 | ||
98 | #ifdef CONFIG_MARKERS_USERSPACE | |
99 | static void marker_update_processes(void); | |
100 | #else | |
101 | static void marker_update_processes(void) | |
102 | { | |
103 | } | |
104 | #endif | |
105 | ||
106 | /** | |
107 | * __mark_empty_function - Empty probe callback | |
108 | * @mdata: marker data | |
109 | * @probe_private: probe private data | |
110 | * @call_private: call site private data | |
111 | * @fmt: format string | |
112 | * @...: variable argument list | |
113 | * | |
114 | * Empty callback provided as a probe to the markers. By providing this to a | |
115 | * disabled marker, we make sure the execution flow is always valid even | |
116 | * though the function pointer change and the marker enabling are two distinct | |
117 | * operations that modifies the execution flow of preemptible code. | |
118 | */ | |
119 | notrace void __mark_empty_function(const struct marker *mdata, | |
120 | void *probe_private, void *call_private, const char *fmt, va_list *args) | |
121 | { | |
122 | } | |
59b161cd | 123 | //ust// EXPORT_SYMBOL_GPL(__mark_empty_function); |
68c1021b PMF |
124 | |
125 | /* | |
126 | * marker_probe_cb Callback that prepares the variable argument list for probes. | |
127 | * @mdata: pointer of type struct marker | |
128 | * @call_private: caller site private data | |
129 | * @...: Variable argument list. | |
130 | * | |
131 | * Since we do not use "typical" pointer based RCU in the 1 argument case, we | |
132 | * need to put a full smp_rmb() in this branch. This is why we do not use | |
133 | * rcu_dereference() for the pointer read. | |
134 | */ | |
135 | notrace void marker_probe_cb(const struct marker *mdata, | |
136 | void *call_private, ...) | |
137 | { | |
138 | va_list args; | |
139 | char ptype; | |
140 | ||
141 | /* | |
142 | * rcu_read_lock_sched does two things : disabling preemption to make | |
143 | * sure the teardown of the callbacks can be done correctly when they | |
144 | * are in modules and they insure RCU read coherency. | |
145 | */ | |
59b161cd | 146 | //ust// rcu_read_lock_sched_notrace(); |
68c1021b PMF |
147 | ptype = mdata->ptype; |
148 | if (likely(!ptype)) { | |
149 | marker_probe_func *func; | |
150 | /* Must read the ptype before ptr. They are not data dependant, | |
151 | * so we put an explicit smp_rmb() here. */ | |
152 | smp_rmb(); | |
153 | func = mdata->single.func; | |
154 | /* Must read the ptr before private data. They are not data | |
155 | * dependant, so we put an explicit smp_rmb() here. */ | |
156 | smp_rmb(); | |
157 | va_start(args, call_private); | |
158 | func(mdata, mdata->single.probe_private, call_private, | |
159 | mdata->format, &args); | |
160 | va_end(args); | |
161 | } else { | |
162 | struct marker_probe_closure *multi; | |
163 | int i; | |
164 | /* | |
165 | * Read mdata->ptype before mdata->multi. | |
166 | */ | |
167 | smp_rmb(); | |
168 | multi = mdata->multi; | |
169 | /* | |
170 | * multi points to an array, therefore accessing the array | |
171 | * depends on reading multi. However, even in this case, | |
172 | * we must insure that the pointer is read _before_ the array | |
173 | * data. Same as rcu_dereference, but we need a full smp_rmb() | |
174 | * in the fast path, so put the explicit barrier here. | |
175 | */ | |
176 | smp_read_barrier_depends(); | |
177 | for (i = 0; multi[i].func; i++) { | |
178 | va_start(args, call_private); | |
179 | multi[i].func(mdata, multi[i].probe_private, | |
180 | call_private, mdata->format, &args); | |
181 | va_end(args); | |
182 | } | |
183 | } | |
59b161cd | 184 | //ust// rcu_read_unlock_sched_notrace(); |
68c1021b | 185 | } |
59b161cd | 186 | //ust// EXPORT_SYMBOL_GPL(marker_probe_cb); |
68c1021b PMF |
187 | |
188 | /* | |
189 | * marker_probe_cb Callback that does not prepare the variable argument list. | |
190 | * @mdata: pointer of type struct marker | |
191 | * @call_private: caller site private data | |
192 | * @...: Variable argument list. | |
193 | * | |
194 | * Should be connected to markers "MARK_NOARGS". | |
195 | */ | |
196 | static notrace void marker_probe_cb_noarg(const struct marker *mdata, | |
197 | void *call_private, ...) | |
198 | { | |
199 | va_list args; /* not initialized */ | |
200 | char ptype; | |
201 | ||
59b161cd | 202 | //ust// rcu_read_lock_sched_notrace(); |
68c1021b PMF |
203 | ptype = mdata->ptype; |
204 | if (likely(!ptype)) { | |
205 | marker_probe_func *func; | |
206 | /* Must read the ptype before ptr. They are not data dependant, | |
207 | * so we put an explicit smp_rmb() here. */ | |
208 | smp_rmb(); | |
209 | func = mdata->single.func; | |
210 | /* Must read the ptr before private data. They are not data | |
211 | * dependant, so we put an explicit smp_rmb() here. */ | |
212 | smp_rmb(); | |
213 | func(mdata, mdata->single.probe_private, call_private, | |
214 | mdata->format, &args); | |
215 | } else { | |
216 | struct marker_probe_closure *multi; | |
217 | int i; | |
218 | /* | |
219 | * Read mdata->ptype before mdata->multi. | |
220 | */ | |
221 | smp_rmb(); | |
222 | multi = mdata->multi; | |
223 | /* | |
224 | * multi points to an array, therefore accessing the array | |
225 | * depends on reading multi. However, even in this case, | |
226 | * we must insure that the pointer is read _before_ the array | |
227 | * data. Same as rcu_dereference, but we need a full smp_rmb() | |
228 | * in the fast path, so put the explicit barrier here. | |
229 | */ | |
230 | smp_read_barrier_depends(); | |
231 | for (i = 0; multi[i].func; i++) | |
232 | multi[i].func(mdata, multi[i].probe_private, | |
233 | call_private, mdata->format, &args); | |
234 | } | |
59b161cd | 235 | //ust// rcu_read_unlock_sched_notrace(); |
68c1021b PMF |
236 | } |
237 | ||
238 | static void free_old_closure(struct rcu_head *head) | |
239 | { | |
240 | struct marker_entry *entry = container_of(head, | |
241 | struct marker_entry, rcu); | |
242 | kfree(entry->oldptr); | |
243 | /* Make sure we free the data before setting the pending flag to 0 */ | |
244 | smp_wmb(); | |
245 | entry->rcu_pending = 0; | |
246 | } | |
247 | ||
248 | static void debug_print_probes(struct marker_entry *entry) | |
249 | { | |
250 | int i; | |
251 | ||
252 | if (!marker_debug) | |
253 | return; | |
254 | ||
255 | if (!entry->ptype) { | |
256 | printk(KERN_DEBUG "Single probe : %p %p\n", | |
257 | entry->single.func, | |
258 | entry->single.probe_private); | |
259 | } else { | |
260 | for (i = 0; entry->multi[i].func; i++) | |
261 | printk(KERN_DEBUG "Multi probe %d : %p %p\n", i, | |
262 | entry->multi[i].func, | |
263 | entry->multi[i].probe_private); | |
264 | } | |
265 | } | |
266 | ||
267 | static struct marker_probe_closure * | |
268 | marker_entry_add_probe(struct marker_entry *entry, | |
269 | marker_probe_func *probe, void *probe_private) | |
270 | { | |
271 | int nr_probes = 0; | |
272 | struct marker_probe_closure *old, *new; | |
273 | ||
274 | WARN_ON(!probe); | |
275 | ||
276 | debug_print_probes(entry); | |
277 | old = entry->multi; | |
278 | if (!entry->ptype) { | |
279 | if (entry->single.func == probe && | |
280 | entry->single.probe_private == probe_private) | |
281 | return ERR_PTR(-EBUSY); | |
282 | if (entry->single.func == __mark_empty_function) { | |
283 | /* 0 -> 1 probes */ | |
284 | entry->single.func = probe; | |
285 | entry->single.probe_private = probe_private; | |
286 | entry->refcount = 1; | |
287 | entry->ptype = 0; | |
288 | debug_print_probes(entry); | |
289 | return NULL; | |
290 | } else { | |
291 | /* 1 -> 2 probes */ | |
292 | nr_probes = 1; | |
293 | old = NULL; | |
294 | } | |
295 | } else { | |
296 | /* (N -> N+1), (N != 0, 1) probes */ | |
297 | for (nr_probes = 0; old[nr_probes].func; nr_probes++) | |
298 | if (old[nr_probes].func == probe | |
299 | && old[nr_probes].probe_private | |
300 | == probe_private) | |
301 | return ERR_PTR(-EBUSY); | |
302 | } | |
303 | /* + 2 : one for new probe, one for NULL func */ | |
304 | new = kzalloc((nr_probes + 2) * sizeof(struct marker_probe_closure), | |
305 | GFP_KERNEL); | |
306 | if (new == NULL) | |
307 | return ERR_PTR(-ENOMEM); | |
308 | if (!old) | |
309 | new[0] = entry->single; | |
310 | else | |
311 | memcpy(new, old, | |
312 | nr_probes * sizeof(struct marker_probe_closure)); | |
313 | new[nr_probes].func = probe; | |
314 | new[nr_probes].probe_private = probe_private; | |
315 | entry->refcount = nr_probes + 1; | |
316 | entry->multi = new; | |
317 | entry->ptype = 1; | |
318 | debug_print_probes(entry); | |
319 | return old; | |
320 | } | |
321 | ||
322 | static struct marker_probe_closure * | |
323 | marker_entry_remove_probe(struct marker_entry *entry, | |
324 | marker_probe_func *probe, void *probe_private) | |
325 | { | |
326 | int nr_probes = 0, nr_del = 0, i; | |
327 | struct marker_probe_closure *old, *new; | |
328 | ||
329 | old = entry->multi; | |
330 | ||
331 | debug_print_probes(entry); | |
332 | if (!entry->ptype) { | |
333 | /* 0 -> N is an error */ | |
334 | WARN_ON(entry->single.func == __mark_empty_function); | |
335 | /* 1 -> 0 probes */ | |
336 | WARN_ON(probe && entry->single.func != probe); | |
337 | WARN_ON(entry->single.probe_private != probe_private); | |
338 | entry->single.func = __mark_empty_function; | |
339 | entry->refcount = 0; | |
340 | entry->ptype = 0; | |
341 | debug_print_probes(entry); | |
342 | return NULL; | |
343 | } else { | |
344 | /* (N -> M), (N > 1, M >= 0) probes */ | |
345 | for (nr_probes = 0; old[nr_probes].func; nr_probes++) { | |
346 | if ((!probe || old[nr_probes].func == probe) | |
347 | && old[nr_probes].probe_private | |
348 | == probe_private) | |
349 | nr_del++; | |
350 | } | |
351 | } | |
352 | ||
353 | if (nr_probes - nr_del == 0) { | |
354 | /* N -> 0, (N > 1) */ | |
355 | entry->single.func = __mark_empty_function; | |
356 | entry->refcount = 0; | |
357 | entry->ptype = 0; | |
358 | } else if (nr_probes - nr_del == 1) { | |
359 | /* N -> 1, (N > 1) */ | |
360 | for (i = 0; old[i].func; i++) | |
361 | if ((probe && old[i].func != probe) || | |
362 | old[i].probe_private != probe_private) | |
363 | entry->single = old[i]; | |
364 | entry->refcount = 1; | |
365 | entry->ptype = 0; | |
366 | } else { | |
367 | int j = 0; | |
368 | /* N -> M, (N > 1, M > 1) */ | |
369 | /* + 1 for NULL */ | |
370 | new = kzalloc((nr_probes - nr_del + 1) | |
371 | * sizeof(struct marker_probe_closure), GFP_KERNEL); | |
372 | if (new == NULL) | |
373 | return ERR_PTR(-ENOMEM); | |
374 | for (i = 0; old[i].func; i++) | |
375 | if ((probe && old[i].func != probe) || | |
376 | old[i].probe_private != probe_private) | |
377 | new[j++] = old[i]; | |
378 | entry->refcount = nr_probes - nr_del; | |
379 | entry->ptype = 1; | |
380 | entry->multi = new; | |
381 | } | |
382 | debug_print_probes(entry); | |
383 | return old; | |
384 | } | |
385 | ||
386 | /* | |
387 | * Get marker if the marker is present in the marker hash table. | |
388 | * Must be called with markers_mutex held. | |
389 | * Returns NULL if not present. | |
390 | */ | |
391 | static struct marker_entry *get_marker(const char *channel, const char *name) | |
392 | { | |
393 | struct hlist_head *head; | |
394 | struct hlist_node *node; | |
395 | struct marker_entry *e; | |
396 | size_t channel_len = strlen(channel) + 1; | |
397 | size_t name_len = strlen(name) + 1; | |
398 | u32 hash; | |
399 | ||
400 | hash = jhash(channel, channel_len-1, 0) ^ jhash(name, name_len-1, 0); | |
401 | head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; | |
402 | hlist_for_each_entry(e, node, head, hlist) { | |
403 | if (!strcmp(channel, e->channel) && !strcmp(name, e->name)) | |
404 | return e; | |
405 | } | |
406 | return NULL; | |
407 | } | |
408 | ||
409 | /* | |
410 | * Add the marker to the marker hash table. Must be called with markers_mutex | |
411 | * held. | |
412 | */ | |
413 | static struct marker_entry *add_marker(const char *channel, const char *name, | |
414 | const char *format) | |
415 | { | |
416 | struct hlist_head *head; | |
417 | struct hlist_node *node; | |
418 | struct marker_entry *e; | |
419 | size_t channel_len = strlen(channel) + 1; | |
420 | size_t name_len = strlen(name) + 1; | |
421 | size_t format_len = 0; | |
422 | u32 hash; | |
423 | ||
424 | hash = jhash(channel, channel_len-1, 0) ^ jhash(name, name_len-1, 0); | |
425 | if (format) | |
426 | format_len = strlen(format) + 1; | |
427 | head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; | |
428 | hlist_for_each_entry(e, node, head, hlist) { | |
429 | if (!strcmp(channel, e->channel) && !strcmp(name, e->name)) { | |
430 | printk(KERN_NOTICE | |
431 | "Marker %s.%s busy\n", channel, name); | |
432 | return ERR_PTR(-EBUSY); /* Already there */ | |
433 | } | |
434 | } | |
435 | /* | |
436 | * Using kmalloc here to allocate a variable length element. Could | |
437 | * cause some memory fragmentation if overused. | |
438 | */ | |
439 | e = kmalloc(sizeof(struct marker_entry) | |
440 | + channel_len + name_len + format_len, | |
441 | GFP_KERNEL); | |
442 | if (!e) | |
443 | return ERR_PTR(-ENOMEM); | |
444 | memcpy(e->channel, channel, channel_len); | |
445 | e->name = &e->channel[channel_len]; | |
446 | memcpy(e->name, name, name_len); | |
447 | if (format) { | |
448 | e->format = &e->name[channel_len + name_len]; | |
449 | memcpy(e->format, format, format_len); | |
450 | if (strcmp(e->format, MARK_NOARGS) == 0) | |
451 | e->call = marker_probe_cb_noarg; | |
452 | else | |
453 | e->call = marker_probe_cb; | |
454 | trace_mark(metadata, core_marker_format, | |
455 | "channel %s name %s format %s", | |
456 | e->channel, e->name, e->format); | |
457 | } else { | |
458 | e->format = NULL; | |
459 | e->call = marker_probe_cb; | |
460 | } | |
461 | e->single.func = __mark_empty_function; | |
462 | e->single.probe_private = NULL; | |
463 | e->multi = NULL; | |
464 | e->ptype = 0; | |
465 | e->format_allocated = 0; | |
466 | e->refcount = 0; | |
467 | e->rcu_pending = 0; | |
468 | hlist_add_head(&e->hlist, head); | |
469 | return e; | |
470 | } | |
471 | ||
472 | /* | |
473 | * Remove the marker from the marker hash table. Must be called with mutex_lock | |
474 | * held. | |
475 | */ | |
476 | static int remove_marker(const char *channel, const char *name) | |
477 | { | |
478 | struct hlist_head *head; | |
479 | struct hlist_node *node; | |
480 | struct marker_entry *e; | |
481 | int found = 0; | |
482 | size_t channel_len = strlen(channel) + 1; | |
483 | size_t name_len = strlen(name) + 1; | |
484 | u32 hash; | |
485 | int ret; | |
486 | ||
487 | hash = jhash(channel, channel_len-1, 0) ^ jhash(name, name_len-1, 0); | |
488 | head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; | |
489 | hlist_for_each_entry(e, node, head, hlist) { | |
490 | if (!strcmp(channel, e->channel) && !strcmp(name, e->name)) { | |
491 | found = 1; | |
492 | break; | |
493 | } | |
494 | } | |
495 | if (!found) | |
496 | return -ENOENT; | |
497 | if (e->single.func != __mark_empty_function) | |
498 | return -EBUSY; | |
499 | hlist_del(&e->hlist); | |
500 | if (e->format_allocated) | |
501 | kfree(e->format); | |
502 | ret = ltt_channels_unregister(e->channel); | |
503 | WARN_ON(ret); | |
504 | /* Make sure the call_rcu has been executed */ | |
6cb88bc0 PMF |
505 | //ust// if (e->rcu_pending) |
506 | //ust// rcu_barrier_sched(); | |
68c1021b PMF |
507 | kfree(e); |
508 | return 0; | |
509 | } | |
510 | ||
511 | /* | |
512 | * Set the mark_entry format to the format found in the element. | |
513 | */ | |
514 | static int marker_set_format(struct marker_entry *entry, const char *format) | |
515 | { | |
516 | entry->format = kstrdup(format, GFP_KERNEL); | |
517 | if (!entry->format) | |
518 | return -ENOMEM; | |
519 | entry->format_allocated = 1; | |
520 | ||
521 | trace_mark(metadata, core_marker_format, | |
522 | "channel %s name %s format %s", | |
523 | entry->channel, entry->name, entry->format); | |
524 | return 0; | |
525 | } | |
526 | ||
527 | /* | |
528 | * Sets the probe callback corresponding to one marker. | |
529 | */ | |
530 | static int set_marker(struct marker_entry *entry, struct marker *elem, | |
531 | int active) | |
532 | { | |
533 | int ret = 0; | |
534 | WARN_ON(strcmp(entry->name, elem->name) != 0); | |
535 | ||
536 | if (entry->format) { | |
537 | if (strcmp(entry->format, elem->format) != 0) { | |
538 | printk(KERN_NOTICE | |
539 | "Format mismatch for probe %s " | |
540 | "(%s), marker (%s)\n", | |
541 | entry->name, | |
542 | entry->format, | |
543 | elem->format); | |
544 | return -EPERM; | |
545 | } | |
546 | } else { | |
547 | ret = marker_set_format(entry, elem->format); | |
548 | if (ret) | |
549 | return ret; | |
550 | } | |
551 | ||
552 | /* | |
553 | * probe_cb setup (statically known) is done here. It is | |
554 | * asynchronous with the rest of execution, therefore we only | |
555 | * pass from a "safe" callback (with argument) to an "unsafe" | |
556 | * callback (does not set arguments). | |
557 | */ | |
558 | elem->call = entry->call; | |
559 | elem->channel_id = entry->channel_id; | |
560 | elem->event_id = entry->event_id; | |
561 | /* | |
562 | * Sanity check : | |
563 | * We only update the single probe private data when the ptr is | |
564 | * set to a _non_ single probe! (0 -> 1 and N -> 1, N != 1) | |
565 | */ | |
566 | WARN_ON(elem->single.func != __mark_empty_function | |
567 | && elem->single.probe_private != entry->single.probe_private | |
568 | && !elem->ptype); | |
569 | elem->single.probe_private = entry->single.probe_private; | |
570 | /* | |
571 | * Make sure the private data is valid when we update the | |
572 | * single probe ptr. | |
573 | */ | |
574 | smp_wmb(); | |
575 | elem->single.func = entry->single.func; | |
576 | /* | |
577 | * We also make sure that the new probe callbacks array is consistent | |
578 | * before setting a pointer to it. | |
579 | */ | |
580 | rcu_assign_pointer(elem->multi, entry->multi); | |
581 | /* | |
582 | * Update the function or multi probe array pointer before setting the | |
583 | * ptype. | |
584 | */ | |
585 | smp_wmb(); | |
586 | elem->ptype = entry->ptype; | |
587 | ||
59b161cd PMF |
588 | //ust// if (elem->tp_name && (active ^ _imv_read(elem->state))) { |
589 | //ust// WARN_ON(!elem->tp_cb); | |
590 | //ust// /* | |
591 | //ust// * It is ok to directly call the probe registration because type | |
592 | //ust// * checking has been done in the __trace_mark_tp() macro. | |
593 | //ust// */ | |
594 | //ust// | |
595 | //ust// if (active) { | |
596 | //ust// /* | |
597 | //ust// * try_module_get should always succeed because we hold | |
598 | //ust// * markers_mutex to get the tp_cb address. | |
599 | //ust// */ | |
600 | //ust// ret = try_module_get(__module_text_address( | |
601 | //ust// (unsigned long)elem->tp_cb)); | |
602 | //ust// BUG_ON(!ret); | |
603 | //ust// ret = tracepoint_probe_register_noupdate( | |
604 | //ust// elem->tp_name, | |
605 | //ust// elem->tp_cb); | |
606 | //ust// } else { | |
607 | //ust// ret = tracepoint_probe_unregister_noupdate( | |
608 | //ust// elem->tp_name, | |
609 | //ust// elem->tp_cb); | |
610 | //ust// /* | |
611 | //ust// * tracepoint_probe_update_all() must be called | |
612 | //ust// * before the module containing tp_cb is unloaded. | |
613 | //ust// */ | |
614 | //ust// module_put(__module_text_address( | |
615 | //ust// (unsigned long)elem->tp_cb)); | |
616 | //ust// } | |
617 | //ust// } | |
68c1021b PMF |
618 | elem->state__imv = active; |
619 | ||
620 | return ret; | |
621 | } | |
622 | ||
623 | /* | |
624 | * Disable a marker and its probe callback. | |
625 | * Note: only waiting an RCU period after setting elem->call to the empty | |
626 | * function insures that the original callback is not used anymore. This insured | |
627 | * by rcu_read_lock_sched around the call site. | |
628 | */ | |
629 | static void disable_marker(struct marker *elem) | |
630 | { | |
631 | int ret; | |
632 | ||
633 | /* leave "call" as is. It is known statically. */ | |
59b161cd PMF |
634 | //ust// if (elem->tp_name && _imv_read(elem->state)) { |
635 | //ust// WARN_ON(!elem->tp_cb); | |
636 | //ust// /* | |
637 | //ust// * It is ok to directly call the probe registration because type | |
638 | //ust// * checking has been done in the __trace_mark_tp() macro. | |
639 | //ust// */ | |
640 | //ust// ret = tracepoint_probe_unregister_noupdate(elem->tp_name, | |
641 | //ust// elem->tp_cb); | |
642 | //ust// WARN_ON(ret); | |
643 | //ust// /* | |
644 | //ust// * tracepoint_probe_update_all() must be called | |
645 | //ust// * before the module containing tp_cb is unloaded. | |
646 | //ust// */ | |
647 | //ust// module_put(__module_text_address((unsigned long)elem->tp_cb)); | |
648 | //ust// } | |
68c1021b PMF |
649 | elem->state__imv = 0; |
650 | elem->single.func = __mark_empty_function; | |
651 | /* Update the function before setting the ptype */ | |
652 | smp_wmb(); | |
653 | elem->ptype = 0; /* single probe */ | |
654 | /* | |
655 | * Leave the private data and channel_id/event_id there, because removal | |
656 | * is racy and should be done only after an RCU period. These are never | |
657 | * used until the next initialization anyway. | |
658 | */ | |
659 | } | |
660 | ||
661 | /** | |
662 | * marker_update_probe_range - Update a probe range | |
663 | * @begin: beginning of the range | |
664 | * @end: end of the range | |
665 | * | |
666 | * Updates the probe callback corresponding to a range of markers. | |
667 | */ | |
668 | void marker_update_probe_range(struct marker *begin, | |
669 | struct marker *end) | |
670 | { | |
671 | struct marker *iter; | |
672 | struct marker_entry *mark_entry; | |
673 | ||
674 | mutex_lock(&markers_mutex); | |
675 | for (iter = begin; iter < end; iter++) { | |
676 | mark_entry = get_marker(iter->channel, iter->name); | |
677 | if (mark_entry) { | |
678 | set_marker(mark_entry, iter, !!mark_entry->refcount); | |
679 | /* | |
680 | * ignore error, continue | |
681 | */ | |
4db647c5 PMF |
682 | |
683 | /* This is added for UST. We emit a core_marker_id event | |
684 | * for markers that are already registered to a probe | |
685 | * upon library load. Otherwise, no core_marker_id will | |
686 | * be generated for these markers. Is this the right thing | |
687 | * to do? | |
688 | */ | |
689 | trace_mark(metadata, core_marker_id, | |
690 | "channel %s name %s event_id %hu " | |
691 | "int #1u%zu long #1u%zu pointer #1u%zu " | |
692 | "size_t #1u%zu alignment #1u%u", | |
693 | iter->channel, iter->name, mark_entry->event_id, | |
694 | sizeof(int), sizeof(long), sizeof(void *), | |
695 | sizeof(size_t), ltt_get_alignment()); | |
68c1021b PMF |
696 | } else { |
697 | disable_marker(iter); | |
698 | } | |
699 | } | |
700 | mutex_unlock(&markers_mutex); | |
701 | } | |
702 | ||
703 | /* | |
704 | * Update probes, removing the faulty probes. | |
705 | * | |
706 | * Internal callback only changed before the first probe is connected to it. | |
707 | * Single probe private data can only be changed on 0 -> 1 and 2 -> 1 | |
708 | * transitions. All other transitions will leave the old private data valid. | |
709 | * This makes the non-atomicity of the callback/private data updates valid. | |
710 | * | |
711 | * "special case" updates : | |
712 | * 0 -> 1 callback | |
713 | * 1 -> 0 callback | |
714 | * 1 -> 2 callbacks | |
715 | * 2 -> 1 callbacks | |
716 | * Other updates all behave the same, just like the 2 -> 3 or 3 -> 2 updates. | |
717 | * Site effect : marker_set_format may delete the marker entry (creating a | |
718 | * replacement). | |
719 | */ | |
720 | static void marker_update_probes(void) | |
721 | { | |
722 | /* Core kernel markers */ | |
c463904d | 723 | //ust// marker_update_probe_range(__start___markers, __stop___markers); |
68c1021b | 724 | /* Markers in modules. */ |
59b161cd | 725 | //ust// module_update_markers(); |
c463904d | 726 | lib_update_markers(); |
b6bf28ec | 727 | //ust// tracepoint_probe_update_all(); |
68c1021b PMF |
728 | /* Update immediate values */ |
729 | core_imv_update(); | |
474d745f | 730 | //ust// module_imv_update(); /* FIXME: need to port for libs? */ |
68c1021b PMF |
731 | marker_update_processes(); |
732 | } | |
733 | ||
734 | /** | |
735 | * marker_probe_register - Connect a probe to a marker | |
736 | * @channel: marker channel | |
737 | * @name: marker name | |
738 | * @format: format string | |
739 | * @probe: probe handler | |
740 | * @probe_private: probe private data | |
741 | * | |
742 | * private data must be a valid allocated memory address, or NULL. | |
743 | * Returns 0 if ok, error value on error. | |
744 | * The probe address must at least be aligned on the architecture pointer size. | |
745 | */ | |
746 | int marker_probe_register(const char *channel, const char *name, | |
747 | const char *format, marker_probe_func *probe, | |
748 | void *probe_private) | |
749 | { | |
750 | struct marker_entry *entry; | |
751 | int ret = 0, ret_err; | |
752 | struct marker_probe_closure *old; | |
753 | int first_probe = 0; | |
754 | ||
755 | mutex_lock(&markers_mutex); | |
756 | entry = get_marker(channel, name); | |
757 | if (!entry) { | |
758 | first_probe = 1; | |
759 | entry = add_marker(channel, name, format); | |
760 | if (IS_ERR(entry)) | |
761 | ret = PTR_ERR(entry); | |
762 | if (ret) | |
763 | goto end; | |
764 | ret = ltt_channels_register(channel); | |
765 | if (ret) | |
766 | goto error_remove_marker; | |
767 | ret = ltt_channels_get_index_from_name(channel); | |
768 | if (ret < 0) | |
769 | goto error_unregister_channel; | |
770 | entry->channel_id = ret; | |
771 | ret = ltt_channels_get_event_id(channel, name); | |
772 | if (ret < 0) | |
773 | goto error_unregister_channel; | |
774 | entry->event_id = ret; | |
775 | ret = 0; | |
776 | trace_mark(metadata, core_marker_id, | |
777 | "channel %s name %s event_id %hu " | |
778 | "int #1u%zu long #1u%zu pointer #1u%zu " | |
779 | "size_t #1u%zu alignment #1u%u", | |
780 | channel, name, entry->event_id, | |
781 | sizeof(int), sizeof(long), sizeof(void *), | |
782 | sizeof(size_t), ltt_get_alignment()); | |
783 | } else if (format) { | |
784 | if (!entry->format) | |
785 | ret = marker_set_format(entry, format); | |
786 | else if (strcmp(entry->format, format)) | |
787 | ret = -EPERM; | |
788 | if (ret) | |
789 | goto end; | |
790 | } | |
791 | ||
792 | /* | |
793 | * If we detect that a call_rcu is pending for this marker, | |
794 | * make sure it's executed now. | |
795 | */ | |
6cb88bc0 PMF |
796 | //ust// if (entry->rcu_pending) |
797 | //ust// rcu_barrier_sched(); | |
68c1021b PMF |
798 | old = marker_entry_add_probe(entry, probe, probe_private); |
799 | if (IS_ERR(old)) { | |
800 | ret = PTR_ERR(old); | |
801 | if (first_probe) | |
802 | goto error_unregister_channel; | |
803 | else | |
804 | goto end; | |
805 | } | |
806 | mutex_unlock(&markers_mutex); | |
807 | ||
808 | marker_update_probes(); | |
809 | ||
810 | mutex_lock(&markers_mutex); | |
811 | entry = get_marker(channel, name); | |
812 | if (!entry) | |
813 | goto end; | |
6cb88bc0 PMF |
814 | //ust// if (entry->rcu_pending) |
815 | //ust// rcu_barrier_sched(); | |
68c1021b PMF |
816 | entry->oldptr = old; |
817 | entry->rcu_pending = 1; | |
818 | /* write rcu_pending before calling the RCU callback */ | |
819 | smp_wmb(); | |
6cb88bc0 PMF |
820 | //ust// call_rcu_sched(&entry->rcu, free_old_closure); |
821 | synchronize_rcu(); free_old_closure(&entry->rcu); | |
68c1021b PMF |
822 | goto end; |
823 | ||
824 | error_unregister_channel: | |
825 | ret_err = ltt_channels_unregister(channel); | |
826 | WARN_ON(ret_err); | |
827 | error_remove_marker: | |
828 | ret_err = remove_marker(channel, name); | |
829 | WARN_ON(ret_err); | |
830 | end: | |
831 | mutex_unlock(&markers_mutex); | |
832 | return ret; | |
833 | } | |
59b161cd | 834 | //ust// EXPORT_SYMBOL_GPL(marker_probe_register); |
68c1021b PMF |
835 | |
836 | /** | |
837 | * marker_probe_unregister - Disconnect a probe from a marker | |
838 | * @channel: marker channel | |
839 | * @name: marker name | |
840 | * @probe: probe function pointer | |
841 | * @probe_private: probe private data | |
842 | * | |
843 | * Returns the private data given to marker_probe_register, or an ERR_PTR(). | |
844 | * We do not need to call a synchronize_sched to make sure the probes have | |
845 | * finished running before doing a module unload, because the module unload | |
846 | * itself uses stop_machine(), which insures that every preempt disabled section | |
847 | * have finished. | |
848 | */ | |
849 | int marker_probe_unregister(const char *channel, const char *name, | |
850 | marker_probe_func *probe, void *probe_private) | |
851 | { | |
852 | struct marker_entry *entry; | |
853 | struct marker_probe_closure *old; | |
854 | int ret = -ENOENT; | |
855 | ||
856 | mutex_lock(&markers_mutex); | |
857 | entry = get_marker(channel, name); | |
858 | if (!entry) | |
859 | goto end; | |
6cb88bc0 PMF |
860 | //ust// if (entry->rcu_pending) |
861 | //ust// rcu_barrier_sched(); | |
68c1021b PMF |
862 | old = marker_entry_remove_probe(entry, probe, probe_private); |
863 | mutex_unlock(&markers_mutex); | |
864 | ||
865 | marker_update_probes(); | |
866 | ||
867 | mutex_lock(&markers_mutex); | |
868 | entry = get_marker(channel, name); | |
869 | if (!entry) | |
870 | goto end; | |
6cb88bc0 PMF |
871 | //ust// if (entry->rcu_pending) |
872 | //ust// rcu_barrier_sched(); | |
68c1021b PMF |
873 | entry->oldptr = old; |
874 | entry->rcu_pending = 1; | |
875 | /* write rcu_pending before calling the RCU callback */ | |
876 | smp_wmb(); | |
6cb88bc0 PMF |
877 | //ust// call_rcu_sched(&entry->rcu, free_old_closure); |
878 | synchronize_rcu(); free_old_closure(&entry->rcu); | |
68c1021b PMF |
879 | remove_marker(channel, name); /* Ignore busy error message */ |
880 | ret = 0; | |
881 | end: | |
882 | mutex_unlock(&markers_mutex); | |
883 | return ret; | |
884 | } | |
59b161cd | 885 | //ust// EXPORT_SYMBOL_GPL(marker_probe_unregister); |
68c1021b PMF |
886 | |
887 | static struct marker_entry * | |
888 | get_marker_from_private_data(marker_probe_func *probe, void *probe_private) | |
889 | { | |
890 | struct marker_entry *entry; | |
891 | unsigned int i; | |
892 | struct hlist_head *head; | |
893 | struct hlist_node *node; | |
894 | ||
895 | for (i = 0; i < MARKER_TABLE_SIZE; i++) { | |
896 | head = &marker_table[i]; | |
897 | hlist_for_each_entry(entry, node, head, hlist) { | |
898 | if (!entry->ptype) { | |
899 | if (entry->single.func == probe | |
900 | && entry->single.probe_private | |
901 | == probe_private) | |
902 | return entry; | |
903 | } else { | |
904 | struct marker_probe_closure *closure; | |
905 | closure = entry->multi; | |
906 | for (i = 0; closure[i].func; i++) { | |
907 | if (closure[i].func == probe && | |
908 | closure[i].probe_private | |
909 | == probe_private) | |
910 | return entry; | |
911 | } | |
912 | } | |
913 | } | |
914 | } | |
915 | return NULL; | |
916 | } | |
917 | ||
918 | /** | |
919 | * marker_probe_unregister_private_data - Disconnect a probe from a marker | |
920 | * @probe: probe function | |
921 | * @probe_private: probe private data | |
922 | * | |
923 | * Unregister a probe by providing the registered private data. | |
924 | * Only removes the first marker found in hash table. | |
925 | * Return 0 on success or error value. | |
926 | * We do not need to call a synchronize_sched to make sure the probes have | |
927 | * finished running before doing a module unload, because the module unload | |
928 | * itself uses stop_machine(), which insures that every preempt disabled section | |
929 | * have finished. | |
930 | */ | |
931 | int marker_probe_unregister_private_data(marker_probe_func *probe, | |
932 | void *probe_private) | |
933 | { | |
934 | struct marker_entry *entry; | |
935 | int ret = 0; | |
936 | struct marker_probe_closure *old; | |
937 | const char *channel = NULL, *name = NULL; | |
938 | ||
939 | mutex_lock(&markers_mutex); | |
940 | entry = get_marker_from_private_data(probe, probe_private); | |
941 | if (!entry) { | |
942 | ret = -ENOENT; | |
943 | goto end; | |
944 | } | |
6cb88bc0 PMF |
945 | //ust// if (entry->rcu_pending) |
946 | //ust// rcu_barrier_sched(); | |
68c1021b PMF |
947 | old = marker_entry_remove_probe(entry, NULL, probe_private); |
948 | channel = kstrdup(entry->channel, GFP_KERNEL); | |
949 | name = kstrdup(entry->name, GFP_KERNEL); | |
950 | mutex_unlock(&markers_mutex); | |
951 | ||
952 | marker_update_probes(); | |
953 | ||
954 | mutex_lock(&markers_mutex); | |
955 | entry = get_marker(channel, name); | |
956 | if (!entry) | |
957 | goto end; | |
6cb88bc0 PMF |
958 | //ust// if (entry->rcu_pending) |
959 | //ust// rcu_barrier_sched(); | |
68c1021b PMF |
960 | entry->oldptr = old; |
961 | entry->rcu_pending = 1; | |
962 | /* write rcu_pending before calling the RCU callback */ | |
963 | smp_wmb(); | |
6cb88bc0 PMF |
964 | //ust// call_rcu_sched(&entry->rcu, free_old_closure); |
965 | synchronize_rcu(); free_old_closure(&entry->rcu); | |
68c1021b PMF |
966 | /* Ignore busy error message */ |
967 | remove_marker(channel, name); | |
968 | end: | |
969 | mutex_unlock(&markers_mutex); | |
970 | kfree(channel); | |
971 | kfree(name); | |
972 | return ret; | |
973 | } | |
59b161cd | 974 | //ust// EXPORT_SYMBOL_GPL(marker_probe_unregister_private_data); |
68c1021b PMF |
975 | |
976 | /** | |
977 | * marker_get_private_data - Get a marker's probe private data | |
978 | * @channel: marker channel | |
979 | * @name: marker name | |
980 | * @probe: probe to match | |
981 | * @num: get the nth matching probe's private data | |
982 | * | |
983 | * Returns the nth private data pointer (starting from 0) matching, or an | |
984 | * ERR_PTR. | |
985 | * Returns the private data pointer, or an ERR_PTR. | |
986 | * The private data pointer should _only_ be dereferenced if the caller is the | |
987 | * owner of the data, or its content could vanish. This is mostly used to | |
988 | * confirm that a caller is the owner of a registered probe. | |
989 | */ | |
990 | void *marker_get_private_data(const char *channel, const char *name, | |
991 | marker_probe_func *probe, int num) | |
992 | { | |
993 | struct hlist_head *head; | |
994 | struct hlist_node *node; | |
995 | struct marker_entry *e; | |
996 | size_t channel_len = strlen(channel) + 1; | |
997 | size_t name_len = strlen(name) + 1; | |
998 | int i; | |
999 | u32 hash; | |
1000 | ||
1001 | hash = jhash(channel, channel_len-1, 0) ^ jhash(name, name_len-1, 0); | |
1002 | head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; | |
1003 | hlist_for_each_entry(e, node, head, hlist) { | |
1004 | if (!strcmp(channel, e->channel) && !strcmp(name, e->name)) { | |
1005 | if (!e->ptype) { | |
1006 | if (num == 0 && e->single.func == probe) | |
1007 | return e->single.probe_private; | |
1008 | } else { | |
1009 | struct marker_probe_closure *closure; | |
1010 | int match = 0; | |
1011 | closure = e->multi; | |
1012 | for (i = 0; closure[i].func; i++) { | |
1013 | if (closure[i].func != probe) | |
1014 | continue; | |
1015 | if (match++ == num) | |
1016 | return closure[i].probe_private; | |
1017 | } | |
1018 | } | |
1019 | break; | |
1020 | } | |
1021 | } | |
1022 | return ERR_PTR(-ENOENT); | |
1023 | } | |
59b161cd | 1024 | //ust// EXPORT_SYMBOL_GPL(marker_get_private_data); |
68c1021b PMF |
1025 | |
1026 | /** | |
1027 | * markers_compact_event_ids - Compact markers event IDs and reassign channels | |
1028 | * | |
1029 | * Called when no channel users are active by the channel infrastructure. | |
1030 | * Called with lock_markers() and channel mutex held. | |
1031 | */ | |
59b161cd PMF |
1032 | //ust// void markers_compact_event_ids(void) |
1033 | //ust// { | |
1034 | //ust// struct marker_entry *entry; | |
1035 | //ust// unsigned int i; | |
1036 | //ust// struct hlist_head *head; | |
1037 | //ust// struct hlist_node *node; | |
1038 | //ust// int ret; | |
1039 | //ust// | |
1040 | //ust// for (i = 0; i < MARKER_TABLE_SIZE; i++) { | |
1041 | //ust// head = &marker_table[i]; | |
1042 | //ust// hlist_for_each_entry(entry, node, head, hlist) { | |
1043 | //ust// ret = ltt_channels_get_index_from_name(entry->channel); | |
1044 | //ust// WARN_ON(ret < 0); | |
1045 | //ust// entry->channel_id = ret; | |
1046 | //ust// ret = _ltt_channels_get_event_id(entry->channel, | |
1047 | //ust// entry->name); | |
1048 | //ust// WARN_ON(ret < 0); | |
1049 | //ust// entry->event_id = ret; | |
1050 | //ust// } | |
1051 | //ust// } | |
1052 | //ust// } | |
68c1021b | 1053 | |
9c67dc50 | 1054 | //ust//#ifdef CONFIG_MODULES |
68c1021b PMF |
1055 | |
1056 | /** | |
1057 | * marker_get_iter_range - Get a next marker iterator given a range. | |
1058 | * @marker: current markers (in), next marker (out) | |
1059 | * @begin: beginning of the range | |
1060 | * @end: end of the range | |
1061 | * | |
1062 | * Returns whether a next marker has been found (1) or not (0). | |
1063 | * Will return the first marker in the range if the input marker is NULL. | |
1064 | */ | |
1065 | int marker_get_iter_range(struct marker **marker, struct marker *begin, | |
1066 | struct marker *end) | |
1067 | { | |
1068 | if (!*marker && begin != end) { | |
1069 | *marker = begin; | |
1070 | return 1; | |
1071 | } | |
1072 | if (*marker >= begin && *marker < end) | |
1073 | return 1; | |
1074 | return 0; | |
1075 | } | |
59b161cd | 1076 | //ust// EXPORT_SYMBOL_GPL(marker_get_iter_range); |
68c1021b PMF |
1077 | |
1078 | static void marker_get_iter(struct marker_iter *iter) | |
1079 | { | |
1080 | int found = 0; | |
1081 | ||
1082 | /* Core kernel markers */ | |
98963de4 | 1083 | if (!iter->lib) { |
c463904d | 1084 | /* ust FIXME: how come we cannot disable the following line? we shouldn't need core stuff */ |
68c1021b PMF |
1085 | found = marker_get_iter_range(&iter->marker, |
1086 | __start___markers, __stop___markers); | |
1087 | if (found) | |
1088 | goto end; | |
1089 | } | |
1090 | /* Markers in modules. */ | |
98963de4 | 1091 | found = lib_get_iter_markers(iter); |
68c1021b PMF |
1092 | end: |
1093 | if (!found) | |
1094 | marker_iter_reset(iter); | |
1095 | } | |
1096 | ||
1097 | void marker_iter_start(struct marker_iter *iter) | |
1098 | { | |
1099 | marker_get_iter(iter); | |
1100 | } | |
59b161cd | 1101 | //ust// EXPORT_SYMBOL_GPL(marker_iter_start); |
68c1021b PMF |
1102 | |
1103 | void marker_iter_next(struct marker_iter *iter) | |
1104 | { | |
1105 | iter->marker++; | |
1106 | /* | |
1107 | * iter->marker may be invalid because we blindly incremented it. | |
1108 | * Make sure it is valid by marshalling on the markers, getting the | |
1109 | * markers from following modules if necessary. | |
1110 | */ | |
1111 | marker_get_iter(iter); | |
1112 | } | |
59b161cd | 1113 | //ust// EXPORT_SYMBOL_GPL(marker_iter_next); |
68c1021b PMF |
1114 | |
1115 | void marker_iter_stop(struct marker_iter *iter) | |
1116 | { | |
1117 | } | |
59b161cd | 1118 | //ust// EXPORT_SYMBOL_GPL(marker_iter_stop); |
68c1021b PMF |
1119 | |
1120 | void marker_iter_reset(struct marker_iter *iter) | |
1121 | { | |
98963de4 | 1122 | iter->lib = NULL; |
68c1021b PMF |
1123 | iter->marker = NULL; |
1124 | } | |
59b161cd | 1125 | //ust// EXPORT_SYMBOL_GPL(marker_iter_reset); |
68c1021b PMF |
1126 | |
1127 | #ifdef CONFIG_MARKERS_USERSPACE | |
1128 | /* | |
1129 | * must be called with current->user_markers_mutex held | |
1130 | */ | |
1131 | static void free_user_marker(char __user *state, struct hlist_head *head) | |
1132 | { | |
1133 | struct user_marker *umark; | |
1134 | struct hlist_node *pos, *n; | |
1135 | ||
1136 | hlist_for_each_entry_safe(umark, pos, n, head, hlist) { | |
1137 | if (umark->state == state) { | |
1138 | hlist_del(&umark->hlist); | |
1139 | kfree(umark); | |
1140 | } | |
1141 | } | |
1142 | } | |
1143 | ||
59b161cd PMF |
1144 | //ust// asmlinkage long sys_marker(char __user *name, char __user *format, |
1145 | //ust// char __user *state, int reg) | |
1146 | //ust// { | |
1147 | //ust// struct user_marker *umark; | |
1148 | //ust// long len; | |
1149 | //ust// struct marker_entry *entry; | |
1150 | //ust// int ret = 0; | |
1151 | //ust// | |
1152 | //ust// printk(KERN_DEBUG "Program %s %s marker [%p, %p]\n", | |
1153 | //ust// current->comm, reg ? "registers" : "unregisters", | |
1154 | //ust// name, state); | |
1155 | //ust// if (reg) { | |
1156 | //ust// umark = kmalloc(sizeof(struct user_marker), GFP_KERNEL); | |
1157 | //ust// umark->name[MAX_USER_MARKER_NAME_LEN - 1] = '\0'; | |
1158 | //ust// umark->format[MAX_USER_MARKER_FORMAT_LEN - 1] = '\0'; | |
1159 | //ust// umark->state = state; | |
1160 | //ust// len = strncpy_from_user(umark->name, name, | |
1161 | //ust// MAX_USER_MARKER_NAME_LEN - 1); | |
1162 | //ust// if (len < 0) { | |
1163 | //ust// ret = -EFAULT; | |
1164 | //ust// goto error; | |
1165 | //ust// } | |
1166 | //ust// len = strncpy_from_user(umark->format, format, | |
1167 | //ust// MAX_USER_MARKER_FORMAT_LEN - 1); | |
1168 | //ust// if (len < 0) { | |
1169 | //ust// ret = -EFAULT; | |
1170 | //ust// goto error; | |
1171 | //ust// } | |
1172 | //ust// printk(KERN_DEBUG "Marker name : %s, format : %s", umark->name, | |
1173 | //ust// umark->format); | |
1174 | //ust// mutex_lock(&markers_mutex); | |
1175 | //ust// entry = get_marker("userspace", umark->name); | |
1176 | //ust// if (entry) { | |
1177 | //ust// if (entry->format && | |
1178 | //ust// strcmp(entry->format, umark->format) != 0) { | |
1179 | //ust// printk(" error, wrong format in process %s", | |
1180 | //ust// current->comm); | |
1181 | //ust// ret = -EPERM; | |
1182 | //ust// goto error_unlock; | |
1183 | //ust// } | |
1184 | //ust// printk(" %s", !!entry->refcount | |
1185 | //ust// ? "enabled" : "disabled"); | |
1186 | //ust// if (put_user(!!entry->refcount, state)) { | |
1187 | //ust// ret = -EFAULT; | |
1188 | //ust// goto error_unlock; | |
1189 | //ust// } | |
1190 | //ust// printk("\n"); | |
1191 | //ust// } else { | |
1192 | //ust// printk(" disabled\n"); | |
1193 | //ust// if (put_user(0, umark->state)) { | |
1194 | //ust// printk(KERN_WARNING | |
1195 | //ust// "Marker in %s caused a fault\n", | |
1196 | //ust// current->comm); | |
1197 | //ust// goto error_unlock; | |
1198 | //ust// } | |
1199 | //ust// } | |
1200 | //ust// mutex_lock(¤t->group_leader->user_markers_mutex); | |
1201 | //ust// hlist_add_head(&umark->hlist, | |
1202 | //ust// ¤t->group_leader->user_markers); | |
1203 | //ust// current->group_leader->user_markers_sequence++; | |
1204 | //ust// mutex_unlock(¤t->group_leader->user_markers_mutex); | |
1205 | //ust// mutex_unlock(&markers_mutex); | |
1206 | //ust// } else { | |
1207 | //ust// mutex_lock(¤t->group_leader->user_markers_mutex); | |
1208 | //ust// free_user_marker(state, | |
1209 | //ust// ¤t->group_leader->user_markers); | |
1210 | //ust// current->group_leader->user_markers_sequence++; | |
1211 | //ust// mutex_unlock(¤t->group_leader->user_markers_mutex); | |
1212 | //ust// } | |
1213 | //ust// goto end; | |
1214 | //ust// error_unlock: | |
1215 | //ust// mutex_unlock(&markers_mutex); | |
1216 | //ust// error: | |
1217 | //ust// kfree(umark); | |
1218 | //ust// end: | |
1219 | //ust// return ret; | |
1220 | //ust// } | |
1221 | //ust// | |
1222 | //ust// /* | |
1223 | //ust// * Types : | |
1224 | //ust// * string : 0 | |
1225 | //ust// */ | |
1226 | //ust// asmlinkage long sys_trace(int type, uint16_t id, | |
1227 | //ust// char __user *ubuf) | |
1228 | //ust// { | |
1229 | //ust// long ret = -EPERM; | |
1230 | //ust// char *page; | |
1231 | //ust// int len; | |
1232 | //ust// | |
1233 | //ust// switch (type) { | |
1234 | //ust// case 0: /* String */ | |
1235 | //ust// ret = -ENOMEM; | |
1236 | //ust// page = (char *)__get_free_page(GFP_TEMPORARY); | |
1237 | //ust// if (!page) | |
1238 | //ust// goto string_out; | |
1239 | //ust// len = strncpy_from_user(page, ubuf, PAGE_SIZE); | |
1240 | //ust// if (len < 0) { | |
1241 | //ust// ret = -EFAULT; | |
1242 | //ust// goto string_err; | |
1243 | //ust// } | |
1244 | //ust// trace_mark(userspace, string, "string %s", page); | |
1245 | //ust// string_err: | |
1246 | //ust// free_page((unsigned long) page); | |
1247 | //ust// string_out: | |
1248 | //ust// break; | |
1249 | //ust// default: | |
1250 | //ust// break; | |
1251 | //ust// } | |
1252 | //ust// return ret; | |
1253 | //ust// } | |
1254 | ||
1255 | //ust// static void marker_update_processes(void) | |
1256 | //ust// { | |
1257 | //ust// struct task_struct *g, *t; | |
1258 | //ust// | |
1259 | //ust// /* | |
1260 | //ust// * markers_mutex is taken to protect the p->user_markers read. | |
1261 | //ust// */ | |
1262 | //ust// mutex_lock(&markers_mutex); | |
1263 | //ust// read_lock(&tasklist_lock); | |
1264 | //ust// for_each_process(g) { | |
1265 | //ust// WARN_ON(!thread_group_leader(g)); | |
1266 | //ust// if (hlist_empty(&g->user_markers)) | |
1267 | //ust// continue; | |
1268 | //ust// if (strcmp(g->comm, "testprog") == 0) | |
1269 | //ust// printk(KERN_DEBUG "set update pending for testprog\n"); | |
1270 | //ust// t = g; | |
1271 | //ust// do { | |
1272 | //ust// /* TODO : implement this thread flag in each arch. */ | |
1273 | //ust// set_tsk_thread_flag(t, TIF_MARKER_PENDING); | |
1274 | //ust// } while ((t = next_thread(t)) != g); | |
1275 | //ust// } | |
1276 | //ust// read_unlock(&tasklist_lock); | |
1277 | //ust// mutex_unlock(&markers_mutex); | |
1278 | //ust// } | |
68c1021b PMF |
1279 | |
1280 | /* | |
1281 | * Update current process. | |
1282 | * Note that we have to wait a whole scheduler period before we are sure that | |
1283 | * every running userspace threads have their markers updated. | |
1284 | * (synchronize_sched() can be used to insure this). | |
1285 | */ | |
1286 | void marker_update_process(void) | |
1287 | { | |
1288 | struct user_marker *umark; | |
1289 | struct hlist_node *pos; | |
1290 | struct marker_entry *entry; | |
1291 | ||
1292 | mutex_lock(&markers_mutex); | |
1293 | mutex_lock(¤t->group_leader->user_markers_mutex); | |
1294 | if (strcmp(current->comm, "testprog") == 0) | |
1295 | printk(KERN_DEBUG "do update pending for testprog\n"); | |
1296 | hlist_for_each_entry(umark, pos, | |
1297 | ¤t->group_leader->user_markers, hlist) { | |
1298 | printk(KERN_DEBUG "Updating marker %s in %s\n", | |
1299 | umark->name, current->comm); | |
1300 | entry = get_marker("userspace", umark->name); | |
1301 | if (entry) { | |
1302 | if (entry->format && | |
1303 | strcmp(entry->format, umark->format) != 0) { | |
1304 | printk(KERN_WARNING | |
1305 | " error, wrong format in process %s\n", | |
1306 | current->comm); | |
1307 | break; | |
1308 | } | |
1309 | if (put_user(!!entry->refcount, umark->state)) { | |
1310 | printk(KERN_WARNING | |
1311 | "Marker in %s caused a fault\n", | |
1312 | current->comm); | |
1313 | break; | |
1314 | } | |
1315 | } else { | |
1316 | if (put_user(0, umark->state)) { | |
1317 | printk(KERN_WARNING | |
1318 | "Marker in %s caused a fault\n", | |
1319 | current->comm); | |
1320 | break; | |
1321 | } | |
1322 | } | |
1323 | } | |
1324 | clear_thread_flag(TIF_MARKER_PENDING); | |
1325 | mutex_unlock(¤t->group_leader->user_markers_mutex); | |
1326 | mutex_unlock(&markers_mutex); | |
1327 | } | |
1328 | ||
1329 | /* | |
1330 | * Called at process exit and upon do_execve(). | |
1331 | * We assume that when the leader exits, no more references can be done to the | |
1332 | * leader structure by the other threads. | |
1333 | */ | |
1334 | void exit_user_markers(struct task_struct *p) | |
1335 | { | |
1336 | struct user_marker *umark; | |
1337 | struct hlist_node *pos, *n; | |
1338 | ||
1339 | if (thread_group_leader(p)) { | |
1340 | mutex_lock(&markers_mutex); | |
1341 | mutex_lock(&p->user_markers_mutex); | |
1342 | hlist_for_each_entry_safe(umark, pos, n, &p->user_markers, | |
1343 | hlist) | |
1344 | kfree(umark); | |
1345 | INIT_HLIST_HEAD(&p->user_markers); | |
1346 | p->user_markers_sequence++; | |
1347 | mutex_unlock(&p->user_markers_mutex); | |
1348 | mutex_unlock(&markers_mutex); | |
1349 | } | |
1350 | } | |
1351 | ||
1352 | int is_marker_enabled(const char *channel, const char *name) | |
1353 | { | |
1354 | struct marker_entry *entry; | |
1355 | ||
1356 | mutex_lock(&markers_mutex); | |
1357 | entry = get_marker(channel, name); | |
1358 | mutex_unlock(&markers_mutex); | |
1359 | ||
1360 | return entry && !!entry->refcount; | |
1361 | } | |
9c67dc50 | 1362 | //ust// #endif |
68c1021b PMF |
1363 | |
1364 | int marker_module_notify(struct notifier_block *self, | |
1365 | unsigned long val, void *data) | |
1366 | { | |
1367 | struct module *mod = data; | |
1368 | ||
1369 | switch (val) { | |
1370 | case MODULE_STATE_COMING: | |
1371 | marker_update_probe_range(mod->markers, | |
1372 | mod->markers + mod->num_markers); | |
1373 | break; | |
1374 | case MODULE_STATE_GOING: | |
1375 | marker_update_probe_range(mod->markers, | |
1376 | mod->markers + mod->num_markers); | |
1377 | break; | |
1378 | } | |
1379 | return 0; | |
1380 | } | |
1381 | ||
1382 | struct notifier_block marker_module_nb = { | |
1383 | .notifier_call = marker_module_notify, | |
1384 | .priority = 0, | |
1385 | }; | |
1386 | ||
59b161cd PMF |
1387 | //ust// static int init_markers(void) |
1388 | //ust// { | |
1389 | //ust// return register_module_notifier(&marker_module_nb); | |
1390 | //ust// } | |
1391 | //ust// __initcall(init_markers); | |
1392 | /* TODO: call marker_module_nb() when a library is linked at runtime (dlopen)? */ | |
68c1021b PMF |
1393 | |
1394 | #endif /* CONFIG_MODULES */ | |
1395 | ||
9c67dc50 PMF |
1396 | void ltt_dump_marker_state(struct ltt_trace_struct *trace) |
1397 | { | |
1398 | struct marker_iter iter; | |
1399 | struct ltt_probe_private_data call_data; | |
1400 | const char *channel; | |
1401 | ||
1402 | call_data.trace = trace; | |
1403 | call_data.serializer = NULL; | |
1404 | ||
1405 | marker_iter_reset(&iter); | |
1406 | marker_iter_start(&iter); | |
1407 | for (; iter.marker != NULL; marker_iter_next(&iter)) { | |
1408 | if (!_imv_read(iter.marker->state)) | |
1409 | continue; | |
1410 | channel = ltt_channels_get_name_from_index( | |
1411 | iter.marker->channel_id); | |
1412 | __trace_mark(0, metadata, core_marker_id, | |
1413 | &call_data, | |
1414 | "channel %s name %s event_id %hu " | |
1415 | "int #1u%zu long #1u%zu pointer #1u%zu " | |
1416 | "size_t #1u%zu alignment #1u%u", | |
1417 | channel, | |
1418 | iter.marker->name, | |
1419 | iter.marker->event_id, | |
1420 | sizeof(int), sizeof(long), | |
1421 | sizeof(void *), sizeof(size_t), | |
1422 | ltt_get_alignment()); | |
1423 | if (iter.marker->format) | |
1424 | __trace_mark(0, metadata, | |
1425 | core_marker_format, | |
1426 | &call_data, | |
1427 | "channel %s name %s format %s", | |
1428 | channel, | |
1429 | iter.marker->name, | |
1430 | iter.marker->format); | |
1431 | } | |
1432 | marker_iter_stop(&iter); | |
1433 | } | |
59b161cd | 1434 | //ust// EXPORT_SYMBOL_GPL(ltt_dump_marker_state); |
98963de4 PMF |
1435 | |
1436 | ||
1437 | static LIST_HEAD(libs); | |
1438 | ||
1439 | /* | |
1440 | * Returns 0 if current not found. | |
1441 | * Returns 1 if current found. | |
1442 | */ | |
1443 | int lib_get_iter_markers(struct marker_iter *iter) | |
1444 | { | |
1445 | struct lib *iter_lib; | |
1446 | int found = 0; | |
1447 | ||
1448 | //ust// mutex_lock(&module_mutex); | |
1449 | list_for_each_entry(iter_lib, &libs, list) { | |
1450 | if (iter_lib < iter->lib) | |
1451 | continue; | |
1452 | else if (iter_lib > iter->lib) | |
1453 | iter->marker = NULL; | |
1454 | found = marker_get_iter_range(&iter->marker, | |
1455 | iter_lib->markers_start, | |
1456 | iter_lib->markers_start + iter_lib->markers_count); | |
1457 | if (found) { | |
1458 | iter->lib = iter_lib; | |
1459 | break; | |
1460 | } | |
1461 | } | |
1462 | //ust// mutex_unlock(&module_mutex); | |
1463 | return found; | |
1464 | } | |
1465 | ||
c463904d PMF |
1466 | void lib_update_markers(void) |
1467 | { | |
1468 | struct lib *lib; | |
1469 | ||
1470 | //ust// mutex_lock(&module_mutex); | |
1471 | list_for_each_entry(lib, &libs, list) | |
1472 | marker_update_probe_range(lib->markers_start, | |
1473 | lib->markers_start + lib->markers_count); | |
1474 | //ust// mutex_unlock(&module_mutex); | |
1475 | } | |
1476 | ||
20b37a31 PMF |
1477 | static void (*new_marker_cb)(struct marker *) = NULL; |
1478 | ||
1479 | void marker_set_new_marker_cb(void (*cb)(struct marker *)) | |
1480 | { | |
1481 | new_marker_cb = cb; | |
1482 | } | |
1483 | ||
1484 | static void new_markers(struct marker *start, struct marker *end) | |
1485 | { | |
1486 | if(new_marker_cb) { | |
1487 | struct marker *m; | |
1488 | for(m=start; m < end; m++) { | |
1489 | new_marker_cb(m); | |
1490 | } | |
1491 | } | |
1492 | } | |
1493 | ||
98963de4 PMF |
1494 | int marker_register_lib(struct marker *markers_start, int markers_count) |
1495 | { | |
1496 | struct lib *pl; | |
1497 | ||
1498 | pl = (struct lib *) malloc(sizeof(struct lib)); | |
1499 | ||
1500 | pl->markers_start = markers_start; | |
1501 | pl->markers_count = markers_count; | |
1502 | ||
0b5207fa PMF |
1503 | /* FIXME: maybe protect this with its own mutex? */ |
1504 | lock_markers(); | |
98963de4 | 1505 | list_add(&pl->list, &libs); |
0b5207fa | 1506 | unlock_markers(); |
98963de4 | 1507 | |
20b37a31 PMF |
1508 | new_markers(markers_start, markers_start + markers_count); |
1509 | ||
4db647c5 PMF |
1510 | /* FIXME: update just the loaded lib */ |
1511 | lib_update_markers(); | |
1512 | ||
1c184644 | 1513 | DBG("just registered a markers section from %p and having %d markers", markers_start, markers_count); |
98963de4 PMF |
1514 | |
1515 | return 0; | |
1516 | } | |
c463904d | 1517 | |
0b5207fa PMF |
1518 | int marker_unregister_lib(struct marker *markers_start, int markers_count) |
1519 | { | |
1520 | /*FIXME: implement; but before implementing, marker_register_lib must | |
1521 | have appropriate locking. */ | |
1522 | ||
1523 | return 0; | |
1524 | } | |
1525 | ||
4db647c5 PMF |
1526 | static int initialized = 0; |
1527 | ||
1528 | void __attribute__((constructor)) init_markers(void) | |
c463904d | 1529 | { |
4db647c5 PMF |
1530 | if(!initialized) { |
1531 | marker_register_lib(__start___markers, (((long)__stop___markers)-((long)__start___markers))/sizeof(struct marker)); | |
1532 | printf("markers_start: %p, markers_stop: %p\n", __start___markers, __stop___markers); | |
1533 | initialized = 1; | |
1534 | } | |
c463904d | 1535 | } |