Commit | Line | Data |
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68c1021b | 1 | /* |
fe566790 | 2 | * Copyright (C) 2007-2011 Mathieu Desnoyers |
68c1021b | 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 | |
f37142a4 MD |
6 | * License as published by the Free Software Foundation; |
7 | * version 2.1 of the License. | |
68c1021b | 8 | * |
34e4b7db | 9 | * This library is distributed in the hope that it will be useful, |
68c1021b | 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
34e4b7db PMF |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
12 | * Lesser General Public License for more details. | |
68c1021b | 13 | * |
34e4b7db PMF |
14 | * You should have received a copy of the GNU Lesser General Public |
15 | * License along with this library; if not, write to the Free Software | |
16 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
68c1021b | 17 | */ |
59b161cd | 18 | |
b0c4126f | 19 | #define _LGPL_SOURCE |
909bc43f PMF |
20 | #include <stdlib.h> |
21 | #include <errno.h> | |
b27f8e75 | 22 | #include <pthread.h> |
730c53dc | 23 | #include <urcu-call-rcu.h> |
b7ea1a1c | 24 | #include <urcu-bp.h> |
17bb07b4 | 25 | #include <urcu/rculist.h> |
10c56168 | 26 | #include <urcu/hlist.h> |
769d0157 | 27 | |
518d7abb | 28 | #include <ust/core.h> |
93d0f2ea | 29 | #include <ust/marker.h> |
535b0d0a | 30 | #include <ust/marker-internal.h> |
fbae86d6 | 31 | #include <ust/tracepoint.h> |
81614639 | 32 | #include <ust/tracepoint-internal.h> |
909bc43f | 33 | |
30ffe279 | 34 | #include "usterr_signal_safe.h" |
59b161cd PMF |
35 | #include "channels.h" |
36 | #include "tracercore.h" | |
c93858f1 | 37 | #include "tracer.h" |
68c1021b | 38 | |
b521931e MD |
39 | extern struct ust_marker * const __start___ust_marker_ptrs[] __attribute__((visibility("hidden"))); |
40 | extern struct ust_marker * const __stop___ust_marker_ptrs[] __attribute__((visibility("hidden"))); | |
defa46a7 | 41 | |
b521931e MD |
42 | /* Set to 1 to enable ust_marker debug output */ |
43 | static const int ust_marker_debug; | |
b27f8e75 MD |
44 | static int initialized; |
45 | static void (*new_ust_marker_cb)(struct ust_marker *); | |
68c1021b PMF |
46 | |
47 | /* | |
fd0a1aea MD |
48 | * ust_marker mutex protects the builtin and module ust_marker and the |
49 | * hash table, as well as the ust_marker_libs list. | |
68c1021b | 50 | */ |
b521931e | 51 | static DEFINE_MUTEX(ust_marker_mutex); |
b521931e | 52 | static CDS_LIST_HEAD(ust_marker_libs); |
772030fe | 53 | |
b27f8e75 MD |
54 | /* |
55 | * Allow nested mutex for mutex listing and nested enable. | |
56 | */ | |
57 | static __thread int nested_mutex; | |
58 | ||
b521931e | 59 | void lock_ust_marker(void) |
68c1021b | 60 | { |
b27f8e75 MD |
61 | if (!(nested_mutex++)) |
62 | pthread_mutex_lock(&ust_marker_mutex); | |
68c1021b PMF |
63 | } |
64 | ||
b521931e | 65 | void unlock_ust_marker(void) |
68c1021b | 66 | { |
b27f8e75 MD |
67 | if (!(--nested_mutex)) |
68 | pthread_mutex_unlock(&ust_marker_mutex); | |
68c1021b PMF |
69 | } |
70 | ||
71 | /* | |
b521931e | 72 | * ust_marker hash table, containing the active ust_marker. |
fd0a1aea | 73 | * Protected by ust_marker mutex. |
68c1021b | 74 | */ |
5cfbb58f MD |
75 | #define UST_MARKER_HASH_BITS 6 |
76 | #define UST_MARKER_TABLE_SIZE (1 << UST_MARKER_HASH_BITS) | |
77 | static struct cds_hlist_head ust_marker_table[UST_MARKER_TABLE_SIZE]; | |
68c1021b | 78 | |
fd0a1aea MD |
79 | struct ust_marker_probe_array { |
80 | struct rcu_head rcu; | |
81 | struct ust_marker_probe_closure c[0]; | |
82 | }; | |
83 | ||
68c1021b PMF |
84 | /* |
85 | * Note about RCU : | |
b521931e MD |
86 | * It is used to make sure every handler has finished using its private |
87 | * data between two consecutive operation (add or remove) on a given | |
88 | * ust_marker. It is also used to delay the free of multiple probes | |
89 | * array until a quiescent state is reached. ust_marker entries | |
90 | * modifications are protected by the ust_marker_mutex. | |
68c1021b | 91 | */ |
b521931e | 92 | struct ust_marker_entry { |
10c56168 | 93 | struct cds_hlist_node hlist; |
68c1021b PMF |
94 | char *format; |
95 | char *name; | |
96 | /* Probe wrapper */ | |
fe566790 | 97 | void (*call)(const struct ust_marker *mdata, void *call_private, ...); |
b521931e | 98 | struct ust_marker_probe_closure single; |
fd0a1aea | 99 | struct ust_marker_probe_array *multi; |
68c1021b | 100 | int refcount; /* Number of times armed. 0 if disarmed. */ |
68c1021b PMF |
101 | u16 channel_id; |
102 | u16 event_id; | |
103 | unsigned char ptype:1; | |
104 | unsigned char format_allocated:1; | |
105 | char channel[0]; /* Contains channel'\0'name'\0'format'\0' */ | |
106 | }; | |
107 | ||
68c1021b | 108 | /** |
b521931e MD |
109 | * __ust_marker_empty_function - Empty probe callback |
110 | * @mdata: ust_marker data | |
68c1021b PMF |
111 | * @probe_private: probe private data |
112 | * @call_private: call site private data | |
113 | * @fmt: format string | |
114 | * @...: variable argument list | |
115 | * | |
b521931e MD |
116 | * Empty callback provided as a probe to the ust_marker. By providing |
117 | * this to a disabled ust_marker, we make sure the execution flow is | |
118 | * always valid even though the function pointer change and the | |
119 | * ust_marker enabling are two distinct operations that modifies the | |
120 | * execution flow of preemptible code. | |
68c1021b | 121 | */ |
b521931e | 122 | notrace void __ust_marker_empty_function(const struct ust_marker *mdata, |
fe566790 | 123 | void *probe_private, void *call_private, const char *fmt, va_list *args) |
68c1021b PMF |
124 | { |
125 | } | |
68c1021b PMF |
126 | |
127 | /* | |
b521931e MD |
128 | * ust_marker_probe_cb Callback that prepares the variable argument list for probes. |
129 | * @mdata: pointer of type struct ust_marker | |
68c1021b PMF |
130 | * @call_private: caller site private data |
131 | * @...: Variable argument list. | |
132 | * | |
133 | * Since we do not use "typical" pointer based RCU in the 1 argument case, we | |
0222e121 | 134 | * need to put a full cmm_smp_rmb() in this branch. This is why we do not use |
68c1021b PMF |
135 | * rcu_dereference() for the pointer read. |
136 | */ | |
b521931e | 137 | notrace void ust_marker_probe_cb(const struct ust_marker *mdata, |
fe566790 | 138 | void *call_private, ...) |
68c1021b PMF |
139 | { |
140 | va_list args; | |
141 | char ptype; | |
142 | ||
143 | /* | |
144 | * rcu_read_lock_sched does two things : disabling preemption to make | |
145 | * sure the teardown of the callbacks can be done correctly when they | |
146 | * are in modules and they insure RCU read coherency. | |
147 | */ | |
fd0a1aea | 148 | rcu_read_lock(); |
68c1021b PMF |
149 | ptype = mdata->ptype; |
150 | if (likely(!ptype)) { | |
b521931e | 151 | ust_marker_probe_func *func; |
68c1021b | 152 | /* Must read the ptype before ptr. They are not data dependant, |
0222e121 MD |
153 | * so we put an explicit cmm_smp_rmb() here. */ |
154 | cmm_smp_rmb(); | |
68c1021b PMF |
155 | func = mdata->single.func; |
156 | /* Must read the ptr before private data. They are not data | |
0222e121 MD |
157 | * dependant, so we put an explicit cmm_smp_rmb() here. */ |
158 | cmm_smp_rmb(); | |
fe566790 MD |
159 | va_start(args, call_private); |
160 | func(mdata, mdata->single.probe_private, call_private, | |
68c1021b PMF |
161 | mdata->format, &args); |
162 | va_end(args); | |
163 | } else { | |
fd0a1aea | 164 | struct ust_marker_probe_array *multi; |
68c1021b PMF |
165 | int i; |
166 | /* | |
167 | * Read mdata->ptype before mdata->multi. | |
168 | */ | |
0222e121 | 169 | cmm_smp_rmb(); |
68c1021b PMF |
170 | multi = mdata->multi; |
171 | /* | |
172 | * multi points to an array, therefore accessing the array | |
173 | * depends on reading multi. However, even in this case, | |
174 | * we must insure that the pointer is read _before_ the array | |
0222e121 MD |
175 | * data. Same as rcu_dereference, but we need a full cmm_smp_rmb() |
176 | * in the fast path, so put the explicit cmm_barrier here. | |
68c1021b | 177 | */ |
0222e121 | 178 | cmm_smp_read_barrier_depends(); |
fd0a1aea | 179 | for (i = 0; multi->c[i].func; i++) { |
fe566790 | 180 | va_start(args, call_private); |
fd0a1aea | 181 | multi->c[i].func(mdata, multi->c[i].probe_private, |
fe566790 | 182 | call_private, mdata->format, &args); |
68c1021b PMF |
183 | va_end(args); |
184 | } | |
185 | } | |
fd0a1aea | 186 | rcu_read_unlock(); |
68c1021b | 187 | } |
68c1021b PMF |
188 | |
189 | /* | |
b521931e MD |
190 | * ust_marker_probe_cb Callback that does not prepare the variable argument list. |
191 | * @mdata: pointer of type struct ust_marker | |
68c1021b PMF |
192 | * @call_private: caller site private data |
193 | * @...: Variable argument list. | |
194 | * | |
b521931e | 195 | * Should be connected to ust_marker "UST_MARKER_NOARGS". |
68c1021b | 196 | */ |
b521931e | 197 | static notrace void ust_marker_probe_cb_noarg(const struct ust_marker *mdata, |
fe566790 | 198 | void *call_private, ...) |
68c1021b PMF |
199 | { |
200 | va_list args; /* not initialized */ | |
201 | char ptype; | |
202 | ||
fd0a1aea | 203 | rcu_read_lock(); |
68c1021b PMF |
204 | ptype = mdata->ptype; |
205 | if (likely(!ptype)) { | |
b521931e | 206 | ust_marker_probe_func *func; |
68c1021b | 207 | /* Must read the ptype before ptr. They are not data dependant, |
0222e121 MD |
208 | * so we put an explicit cmm_smp_rmb() here. */ |
209 | cmm_smp_rmb(); | |
68c1021b PMF |
210 | func = mdata->single.func; |
211 | /* Must read the ptr before private data. They are not data | |
0222e121 MD |
212 | * dependant, so we put an explicit cmm_smp_rmb() here. */ |
213 | cmm_smp_rmb(); | |
fe566790 | 214 | func(mdata, mdata->single.probe_private, call_private, |
68c1021b PMF |
215 | mdata->format, &args); |
216 | } else { | |
fd0a1aea | 217 | struct ust_marker_probe_array *multi; |
68c1021b PMF |
218 | int i; |
219 | /* | |
220 | * Read mdata->ptype before mdata->multi. | |
221 | */ | |
0222e121 | 222 | cmm_smp_rmb(); |
68c1021b PMF |
223 | multi = mdata->multi; |
224 | /* | |
225 | * multi points to an array, therefore accessing the array | |
226 | * depends on reading multi. However, even in this case, | |
227 | * we must insure that the pointer is read _before_ the array | |
0222e121 MD |
228 | * data. Same as rcu_dereference, but we need a full cmm_smp_rmb() |
229 | * in the fast path, so put the explicit cmm_barrier here. | |
68c1021b | 230 | */ |
0222e121 | 231 | cmm_smp_read_barrier_depends(); |
fd0a1aea MD |
232 | for (i = 0; multi->c[i].func; i++) |
233 | multi->c[i].func(mdata, multi->c[i].probe_private, | |
68c1021b PMF |
234 | call_private, mdata->format, &args); |
235 | } | |
fd0a1aea | 236 | rcu_read_unlock(); |
68c1021b PMF |
237 | } |
238 | ||
239 | static void free_old_closure(struct rcu_head *head) | |
240 | { | |
fd0a1aea MD |
241 | struct ust_marker_probe_array *multi = |
242 | _ust_container_of(head, struct ust_marker_probe_array, rcu); | |
243 | free(multi); | |
68c1021b PMF |
244 | } |
245 | ||
b521931e | 246 | static void debug_print_probes(struct ust_marker_entry *entry) |
68c1021b PMF |
247 | { |
248 | int i; | |
249 | ||
b521931e | 250 | if (!ust_marker_debug) |
68c1021b PMF |
251 | return; |
252 | ||
253 | if (!entry->ptype) { | |
c1f20530 | 254 | DBG("Single probe : %p %p", |
68c1021b PMF |
255 | entry->single.func, |
256 | entry->single.probe_private); | |
257 | } else { | |
fd0a1aea | 258 | for (i = 0; entry->multi->c[i].func; i++) |
c1f20530 | 259 | DBG("Multi probe %d : %p %p", i, |
fd0a1aea MD |
260 | entry->multi->c[i].func, |
261 | entry->multi->c[i].probe_private); | |
68c1021b PMF |
262 | } |
263 | } | |
264 | ||
fd0a1aea | 265 | static struct ust_marker_probe_array * |
b521931e MD |
266 | ust_marker_entry_add_probe(struct ust_marker_entry *entry, |
267 | ust_marker_probe_func *probe, void *probe_private) | |
68c1021b PMF |
268 | { |
269 | int nr_probes = 0; | |
fd0a1aea | 270 | struct ust_marker_probe_array *old, *new; |
68c1021b PMF |
271 | |
272 | WARN_ON(!probe); | |
273 | ||
274 | debug_print_probes(entry); | |
275 | old = entry->multi; | |
276 | if (!entry->ptype) { | |
277 | if (entry->single.func == probe && | |
278 | entry->single.probe_private == probe_private) | |
279 | return ERR_PTR(-EBUSY); | |
b521931e | 280 | if (entry->single.func == __ust_marker_empty_function) { |
68c1021b PMF |
281 | /* 0 -> 1 probes */ |
282 | entry->single.func = probe; | |
283 | entry->single.probe_private = probe_private; | |
284 | entry->refcount = 1; | |
285 | entry->ptype = 0; | |
286 | debug_print_probes(entry); | |
287 | return NULL; | |
288 | } else { | |
289 | /* 1 -> 2 probes */ | |
290 | nr_probes = 1; | |
291 | old = NULL; | |
292 | } | |
293 | } else { | |
294 | /* (N -> N+1), (N != 0, 1) probes */ | |
fd0a1aea MD |
295 | for (nr_probes = 0; old->c[nr_probes].func; nr_probes++) |
296 | if (old->c[nr_probes].func == probe | |
297 | && old->c[nr_probes].probe_private | |
68c1021b PMF |
298 | == probe_private) |
299 | return ERR_PTR(-EBUSY); | |
300 | } | |
301 | /* + 2 : one for new probe, one for NULL func */ | |
fd0a1aea MD |
302 | new = zmalloc(sizeof(struct ust_marker_probe_array) |
303 | + ((nr_probes + 2) * sizeof(struct ust_marker_probe_closure))); | |
68c1021b PMF |
304 | if (new == NULL) |
305 | return ERR_PTR(-ENOMEM); | |
306 | if (!old) | |
fd0a1aea | 307 | new->c[0] = entry->single; |
68c1021b | 308 | else |
fd0a1aea | 309 | memcpy(&new->c[0], &old->c[0], |
b521931e | 310 | nr_probes * sizeof(struct ust_marker_probe_closure)); |
fd0a1aea MD |
311 | new->c[nr_probes].func = probe; |
312 | new->c[nr_probes].probe_private = probe_private; | |
68c1021b PMF |
313 | entry->refcount = nr_probes + 1; |
314 | entry->multi = new; | |
315 | entry->ptype = 1; | |
316 | debug_print_probes(entry); | |
317 | return old; | |
318 | } | |
319 | ||
fd0a1aea | 320 | static struct ust_marker_probe_array * |
b521931e MD |
321 | ust_marker_entry_remove_probe(struct ust_marker_entry *entry, |
322 | ust_marker_probe_func *probe, void *probe_private) | |
68c1021b PMF |
323 | { |
324 | int nr_probes = 0, nr_del = 0, i; | |
fd0a1aea | 325 | struct ust_marker_probe_array *old, *new; |
68c1021b PMF |
326 | |
327 | old = entry->multi; | |
328 | ||
329 | debug_print_probes(entry); | |
330 | if (!entry->ptype) { | |
331 | /* 0 -> N is an error */ | |
b521931e | 332 | WARN_ON(entry->single.func == __ust_marker_empty_function); |
68c1021b PMF |
333 | /* 1 -> 0 probes */ |
334 | WARN_ON(probe && entry->single.func != probe); | |
335 | WARN_ON(entry->single.probe_private != probe_private); | |
b521931e | 336 | entry->single.func = __ust_marker_empty_function; |
68c1021b PMF |
337 | entry->refcount = 0; |
338 | entry->ptype = 0; | |
339 | debug_print_probes(entry); | |
340 | return NULL; | |
341 | } else { | |
342 | /* (N -> M), (N > 1, M >= 0) probes */ | |
fd0a1aea MD |
343 | for (nr_probes = 0; old->c[nr_probes].func; nr_probes++) { |
344 | if ((!probe || old->c[nr_probes].func == probe) | |
345 | && old->c[nr_probes].probe_private | |
68c1021b PMF |
346 | == probe_private) |
347 | nr_del++; | |
348 | } | |
349 | } | |
350 | ||
351 | if (nr_probes - nr_del == 0) { | |
352 | /* N -> 0, (N > 1) */ | |
b521931e | 353 | entry->single.func = __ust_marker_empty_function; |
68c1021b PMF |
354 | entry->refcount = 0; |
355 | entry->ptype = 0; | |
356 | } else if (nr_probes - nr_del == 1) { | |
357 | /* N -> 1, (N > 1) */ | |
fd0a1aea MD |
358 | for (i = 0; old->c[i].func; i++) |
359 | if ((probe && old->c[i].func != probe) || | |
360 | old->c[i].probe_private != probe_private) | |
361 | entry->single = old->c[i]; | |
68c1021b PMF |
362 | entry->refcount = 1; |
363 | entry->ptype = 0; | |
364 | } else { | |
365 | int j = 0; | |
366 | /* N -> M, (N > 1, M > 1) */ | |
367 | /* + 1 for NULL */ | |
fd0a1aea MD |
368 | new = zmalloc(sizeof(struct ust_marker_probe_array) |
369 | + ((nr_probes - nr_del + 1) * sizeof(struct ust_marker_probe_closure))); | |
68c1021b PMF |
370 | if (new == NULL) |
371 | return ERR_PTR(-ENOMEM); | |
fd0a1aea MD |
372 | for (i = 0; old->c[i].func; i++) |
373 | if ((probe && old->c[i].func != probe) || | |
374 | old->c[i].probe_private != probe_private) | |
375 | new->c[j++] = old->c[i]; | |
68c1021b PMF |
376 | entry->refcount = nr_probes - nr_del; |
377 | entry->ptype = 1; | |
378 | entry->multi = new; | |
379 | } | |
380 | debug_print_probes(entry); | |
381 | return old; | |
382 | } | |
383 | ||
384 | /* | |
b521931e MD |
385 | * Get ust_marker if the ust_marker is present in the ust_marker hash table. |
386 | * Must be called with ust_marker_mutex held. | |
68c1021b PMF |
387 | * Returns NULL if not present. |
388 | */ | |
b521931e | 389 | static struct ust_marker_entry *get_ust_marker(const char *channel, const char *name) |
68c1021b | 390 | { |
10c56168 DG |
391 | struct cds_hlist_head *head; |
392 | struct cds_hlist_node *node; | |
b521931e | 393 | struct ust_marker_entry *e; |
68c1021b PMF |
394 | size_t channel_len = strlen(channel) + 1; |
395 | size_t name_len = strlen(name) + 1; | |
396 | u32 hash; | |
397 | ||
398 | hash = jhash(channel, channel_len-1, 0) ^ jhash(name, name_len-1, 0); | |
5cfbb58f | 399 | head = &ust_marker_table[hash & ((1 << UST_MARKER_HASH_BITS)-1)]; |
10c56168 | 400 | cds_hlist_for_each_entry(e, node, head, hlist) { |
68c1021b PMF |
401 | if (!strcmp(channel, e->channel) && !strcmp(name, e->name)) |
402 | return e; | |
403 | } | |
404 | return NULL; | |
405 | } | |
406 | ||
407 | /* | |
b521931e MD |
408 | * Add the ust_marker to the ust_marker hash table. Must be called with |
409 | * ust_marker_mutex held. | |
68c1021b | 410 | */ |
b521931e | 411 | static struct ust_marker_entry *add_ust_marker(const char *channel, const char *name, |
68c1021b PMF |
412 | const char *format) |
413 | { | |
10c56168 DG |
414 | struct cds_hlist_head *head; |
415 | struct cds_hlist_node *node; | |
b521931e | 416 | struct ust_marker_entry *e; |
68c1021b PMF |
417 | size_t channel_len = strlen(channel) + 1; |
418 | size_t name_len = strlen(name) + 1; | |
419 | size_t format_len = 0; | |
420 | u32 hash; | |
421 | ||
422 | hash = jhash(channel, channel_len-1, 0) ^ jhash(name, name_len-1, 0); | |
423 | if (format) | |
424 | format_len = strlen(format) + 1; | |
5cfbb58f | 425 | head = &ust_marker_table[hash & ((1 << UST_MARKER_HASH_BITS)-1)]; |
10c56168 | 426 | cds_hlist_for_each_entry(e, node, head, hlist) { |
68c1021b | 427 | if (!strcmp(channel, e->channel) && !strcmp(name, e->name)) { |
b521931e | 428 | DBG("ust_marker %s.%s busy", channel, name); |
68c1021b PMF |
429 | return ERR_PTR(-EBUSY); /* Already there */ |
430 | } | |
431 | } | |
432 | /* | |
1dba3e6c | 433 | * Using zmalloc here to allocate a variable length element. Could |
68c1021b PMF |
434 | * cause some memory fragmentation if overused. |
435 | */ | |
b521931e | 436 | e = zmalloc(sizeof(struct ust_marker_entry) |
909bc43f | 437 | + channel_len + name_len + format_len); |
68c1021b PMF |
438 | if (!e) |
439 | return ERR_PTR(-ENOMEM); | |
440 | memcpy(e->channel, channel, channel_len); | |
441 | e->name = &e->channel[channel_len]; | |
442 | memcpy(e->name, name, name_len); | |
443 | if (format) { | |
eddb0f66 | 444 | e->format = &e->name[name_len]; |
68c1021b | 445 | memcpy(e->format, format, format_len); |
b521931e MD |
446 | if (strcmp(e->format, UST_MARKER_NOARGS) == 0) |
447 | e->call = ust_marker_probe_cb_noarg; | |
68c1021b | 448 | else |
b521931e | 449 | e->call = ust_marker_probe_cb; |
f36c12ab | 450 | __ust_marker(metadata, core_marker_format, NULL, |
68c1021b PMF |
451 | "channel %s name %s format %s", |
452 | e->channel, e->name, e->format); | |
453 | } else { | |
454 | e->format = NULL; | |
b521931e | 455 | e->call = ust_marker_probe_cb; |
68c1021b | 456 | } |
b521931e | 457 | e->single.func = __ust_marker_empty_function; |
68c1021b PMF |
458 | e->single.probe_private = NULL; |
459 | e->multi = NULL; | |
460 | e->ptype = 0; | |
461 | e->format_allocated = 0; | |
462 | e->refcount = 0; | |
10c56168 | 463 | cds_hlist_add_head(&e->hlist, head); |
68c1021b PMF |
464 | return e; |
465 | } | |
466 | ||
467 | /* | |
b521931e | 468 | * Remove the ust_marker from the ust_marker hash table. Must be called with mutex_lock |
68c1021b PMF |
469 | * held. |
470 | */ | |
b521931e | 471 | static int remove_ust_marker(const char *channel, const char *name) |
68c1021b | 472 | { |
10c56168 DG |
473 | struct cds_hlist_head *head; |
474 | struct cds_hlist_node *node; | |
b521931e | 475 | struct ust_marker_entry *e; |
68c1021b PMF |
476 | int found = 0; |
477 | size_t channel_len = strlen(channel) + 1; | |
478 | size_t name_len = strlen(name) + 1; | |
479 | u32 hash; | |
480 | int ret; | |
481 | ||
482 | hash = jhash(channel, channel_len-1, 0) ^ jhash(name, name_len-1, 0); | |
5cfbb58f | 483 | head = &ust_marker_table[hash & ((1 << UST_MARKER_HASH_BITS)-1)]; |
10c56168 | 484 | cds_hlist_for_each_entry(e, node, head, hlist) { |
68c1021b PMF |
485 | if (!strcmp(channel, e->channel) && !strcmp(name, e->name)) { |
486 | found = 1; | |
487 | break; | |
488 | } | |
489 | } | |
490 | if (!found) | |
491 | return -ENOENT; | |
b521931e | 492 | if (e->single.func != __ust_marker_empty_function) |
68c1021b | 493 | return -EBUSY; |
10c56168 | 494 | cds_hlist_del(&e->hlist); |
68c1021b | 495 | if (e->format_allocated) |
909bc43f | 496 | free(e->format); |
68c1021b PMF |
497 | ret = ltt_channels_unregister(e->channel); |
498 | WARN_ON(ret); | |
909bc43f | 499 | free(e); |
68c1021b PMF |
500 | return 0; |
501 | } | |
502 | ||
503 | /* | |
504 | * Set the mark_entry format to the format found in the element. | |
505 | */ | |
b521931e | 506 | static int ust_marker_set_format(struct ust_marker_entry *entry, const char *format) |
68c1021b | 507 | { |
909bc43f | 508 | entry->format = strdup(format); |
68c1021b PMF |
509 | if (!entry->format) |
510 | return -ENOMEM; | |
511 | entry->format_allocated = 1; | |
512 | ||
f36c12ab | 513 | __ust_marker(metadata, core_marker_format, NULL, |
68c1021b PMF |
514 | "channel %s name %s format %s", |
515 | entry->channel, entry->name, entry->format); | |
516 | return 0; | |
517 | } | |
518 | ||
519 | /* | |
b521931e | 520 | * Sets the probe callback corresponding to one ust_marker. |
68c1021b | 521 | */ |
b521931e | 522 | static int set_ust_marker(struct ust_marker_entry *entry, struct ust_marker *elem, |
68c1021b PMF |
523 | int active) |
524 | { | |
525 | int ret = 0; | |
526 | WARN_ON(strcmp(entry->name, elem->name) != 0); | |
527 | ||
528 | if (entry->format) { | |
529 | if (strcmp(entry->format, elem->format) != 0) { | |
b521931e | 530 | ERR("Format mismatch for probe %s (%s), ust_marker (%s)", |
68c1021b PMF |
531 | entry->name, |
532 | entry->format, | |
533 | elem->format); | |
534 | return -EPERM; | |
535 | } | |
536 | } else { | |
b521931e | 537 | ret = ust_marker_set_format(entry, elem->format); |
68c1021b PMF |
538 | if (ret) |
539 | return ret; | |
540 | } | |
541 | ||
542 | /* | |
543 | * probe_cb setup (statically known) is done here. It is | |
544 | * asynchronous with the rest of execution, therefore we only | |
545 | * pass from a "safe" callback (with argument) to an "unsafe" | |
546 | * callback (does not set arguments). | |
547 | */ | |
548 | elem->call = entry->call; | |
549 | elem->channel_id = entry->channel_id; | |
550 | elem->event_id = entry->event_id; | |
551 | /* | |
552 | * Sanity check : | |
553 | * We only update the single probe private data when the ptr is | |
554 | * set to a _non_ single probe! (0 -> 1 and N -> 1, N != 1) | |
555 | */ | |
b521931e | 556 | WARN_ON(elem->single.func != __ust_marker_empty_function |
68c1021b PMF |
557 | && elem->single.probe_private != entry->single.probe_private |
558 | && !elem->ptype); | |
559 | elem->single.probe_private = entry->single.probe_private; | |
560 | /* | |
561 | * Make sure the private data is valid when we update the | |
562 | * single probe ptr. | |
563 | */ | |
0222e121 | 564 | cmm_smp_wmb(); |
68c1021b PMF |
565 | elem->single.func = entry->single.func; |
566 | /* | |
567 | * We also make sure that the new probe callbacks array is consistent | |
568 | * before setting a pointer to it. | |
569 | */ | |
570 | rcu_assign_pointer(elem->multi, entry->multi); | |
571 | /* | |
572 | * Update the function or multi probe array pointer before setting the | |
573 | * ptype. | |
574 | */ | |
0222e121 | 575 | cmm_smp_wmb(); |
68c1021b PMF |
576 | elem->ptype = entry->ptype; |
577 | ||
f36c12ab | 578 | if (elem->tp_name && (active ^ elem->state)) { |
12e81b07 PMF |
579 | WARN_ON(!elem->tp_cb); |
580 | /* | |
581 | * It is ok to directly call the probe registration because type | |
686debc3 | 582 | * checking has been done in the __ust_marker_tp() macro. |
12e81b07 PMF |
583 | */ |
584 | ||
585 | if (active) { | |
12e81b07 PMF |
586 | ret = tracepoint_probe_register_noupdate( |
587 | elem->tp_name, | |
9b9e13aa | 588 | elem->tp_cb, NULL); |
12e81b07 | 589 | } else { |
12e81b07 PMF |
590 | /* |
591 | * tracepoint_probe_update_all() must be called | |
fd0a1aea | 592 | * before the library containing tp_cb is unloaded. |
12e81b07 | 593 | */ |
fd0a1aea MD |
594 | ret = tracepoint_probe_unregister_noupdate( |
595 | elem->tp_name, | |
596 | elem->tp_cb, NULL); | |
12e81b07 PMF |
597 | } |
598 | } | |
f36c12ab | 599 | elem->state = active; |
68c1021b PMF |
600 | |
601 | return ret; | |
602 | } | |
603 | ||
604 | /* | |
b521931e | 605 | * Disable a ust_marker and its probe callback. |
68c1021b PMF |
606 | * Note: only waiting an RCU period after setting elem->call to the empty |
607 | * function insures that the original callback is not used anymore. This insured | |
fd0a1aea | 608 | * by rcu_read_lock around the call site. |
68c1021b | 609 | */ |
b521931e | 610 | static void disable_ust_marker(struct ust_marker *elem) |
68c1021b | 611 | { |
12e81b07 PMF |
612 | int ret; |
613 | ||
614 | /* leave "call" as is. It is known statically. */ | |
f36c12ab | 615 | if (elem->tp_name && elem->state) { |
12e81b07 PMF |
616 | WARN_ON(!elem->tp_cb); |
617 | /* | |
618 | * It is ok to directly call the probe registration because type | |
686debc3 | 619 | * checking has been done in the __ust_marker_tp() macro. |
12e81b07 | 620 | */ |
12e81b07 PMF |
621 | /* |
622 | * tracepoint_probe_update_all() must be called | |
623 | * before the module containing tp_cb is unloaded. | |
624 | */ | |
fd0a1aea MD |
625 | ret = tracepoint_probe_unregister_noupdate(elem->tp_name, |
626 | elem->tp_cb, NULL); | |
627 | WARN_ON(ret); | |
12e81b07 | 628 | } |
f36c12ab | 629 | elem->state = 0; |
b521931e | 630 | elem->single.func = __ust_marker_empty_function; |
68c1021b | 631 | /* Update the function before setting the ptype */ |
0222e121 | 632 | cmm_smp_wmb(); |
68c1021b PMF |
633 | elem->ptype = 0; /* single probe */ |
634 | /* | |
635 | * Leave the private data and channel_id/event_id there, because removal | |
636 | * is racy and should be done only after an RCU period. These are never | |
637 | * used until the next initialization anyway. | |
638 | */ | |
639 | } | |
640 | ||
a5311005 | 641 | /* |
b521931e | 642 | * is_ust_marker_enabled - Check if a ust_marker is enabled |
a5311005 | 643 | * @channel: channel name |
b521931e | 644 | * @name: ust_marker name |
a5311005 | 645 | * |
b521931e | 646 | * Returns 1 if the ust_marker is enabled, 0 if disabled. |
a5311005 | 647 | */ |
b521931e | 648 | int is_ust_marker_enabled(const char *channel, const char *name) |
a5311005 | 649 | { |
b521931e | 650 | struct ust_marker_entry *entry; |
a5311005 | 651 | |
b27f8e75 | 652 | lock_ust_marker(); |
b521931e | 653 | entry = get_ust_marker(channel, name); |
b27f8e75 | 654 | unlock_ust_marker(); |
a5311005 PMF |
655 | |
656 | return entry && !!entry->refcount; | |
657 | } | |
658 | ||
68c1021b | 659 | /** |
b521931e | 660 | * ust_marker_update_probe_range - Update a probe range |
68c1021b PMF |
661 | * @begin: beginning of the range |
662 | * @end: end of the range | |
663 | * | |
b521931e | 664 | * Updates the probe callback corresponding to a range of ust_marker. |
68c1021b | 665 | */ |
fd0a1aea | 666 | static |
b521931e MD |
667 | void ust_marker_update_probe_range(struct ust_marker * const *begin, |
668 | struct ust_marker * const *end) | |
68c1021b | 669 | { |
b521931e MD |
670 | struct ust_marker * const *iter; |
671 | struct ust_marker_entry *mark_entry; | |
68c1021b | 672 | |
68c1021b | 673 | for (iter = begin; iter < end; iter++) { |
f08ebbe2 MD |
674 | if (!*iter) |
675 | continue; /* skip dummy */ | |
b521931e | 676 | mark_entry = get_ust_marker((*iter)->channel, (*iter)->name); |
68c1021b | 677 | if (mark_entry) { |
b521931e | 678 | set_ust_marker(mark_entry, *iter, !!mark_entry->refcount); |
68c1021b PMF |
679 | /* |
680 | * ignore error, continue | |
681 | */ | |
682 | } else { | |
b521931e | 683 | disable_ust_marker(*iter); |
68c1021b PMF |
684 | } |
685 | } | |
68c1021b PMF |
686 | } |
687 | ||
b521931e | 688 | static void lib_update_ust_marker(void) |
772030fe | 689 | { |
b521931e | 690 | struct ust_marker_lib *lib; |
772030fe | 691 | |
b27f8e75 | 692 | lock_ust_marker(); |
b521931e MD |
693 | cds_list_for_each_entry(lib, &ust_marker_libs, list) |
694 | ust_marker_update_probe_range(lib->ust_marker_start, | |
695 | lib->ust_marker_start + lib->ust_marker_count); | |
b27f8e75 | 696 | unlock_ust_marker(); |
772030fe PMF |
697 | } |
698 | ||
68c1021b PMF |
699 | /* |
700 | * Update probes, removing the faulty probes. | |
701 | * | |
702 | * Internal callback only changed before the first probe is connected to it. | |
703 | * Single probe private data can only be changed on 0 -> 1 and 2 -> 1 | |
704 | * transitions. All other transitions will leave the old private data valid. | |
705 | * This makes the non-atomicity of the callback/private data updates valid. | |
706 | * | |
707 | * "special case" updates : | |
708 | * 0 -> 1 callback | |
709 | * 1 -> 0 callback | |
710 | * 1 -> 2 callbacks | |
711 | * 2 -> 1 callbacks | |
712 | * Other updates all behave the same, just like the 2 -> 3 or 3 -> 2 updates. | |
b521931e | 713 | * Site effect : ust_marker_set_format may delete the ust_marker entry (creating a |
68c1021b PMF |
714 | * replacement). |
715 | */ | |
b521931e | 716 | static void ust_marker_update_probes(void) |
68c1021b | 717 | { |
b521931e | 718 | lib_update_ust_marker(); |
12e81b07 | 719 | tracepoint_probe_update_all(); |
68c1021b PMF |
720 | } |
721 | ||
722 | /** | |
b521931e MD |
723 | * ust_marker_probe_register - Connect a probe to a ust_marker |
724 | * @channel: ust_marker channel | |
725 | * @name: ust_marker name | |
68c1021b PMF |
726 | * @format: format string |
727 | * @probe: probe handler | |
728 | * @probe_private: probe private data | |
729 | * | |
730 | * private data must be a valid allocated memory address, or NULL. | |
731 | * Returns 0 if ok, error value on error. | |
732 | * The probe address must at least be aligned on the architecture pointer size. | |
733 | */ | |
b521931e MD |
734 | int ust_marker_probe_register(const char *channel, const char *name, |
735 | const char *format, ust_marker_probe_func *probe, | |
68c1021b PMF |
736 | void *probe_private) |
737 | { | |
b521931e | 738 | struct ust_marker_entry *entry; |
68c1021b | 739 | int ret = 0, ret_err; |
fd0a1aea | 740 | struct ust_marker_probe_array *old; |
68c1021b PMF |
741 | int first_probe = 0; |
742 | ||
b27f8e75 | 743 | lock_ust_marker(); |
b521931e | 744 | entry = get_ust_marker(channel, name); |
68c1021b PMF |
745 | if (!entry) { |
746 | first_probe = 1; | |
b521931e | 747 | entry = add_ust_marker(channel, name, format); |
68c1021b PMF |
748 | if (IS_ERR(entry)) |
749 | ret = PTR_ERR(entry); | |
750 | if (ret) | |
751 | goto end; | |
752 | ret = ltt_channels_register(channel); | |
753 | if (ret) | |
b521931e | 754 | goto error_remove_ust_marker; |
68c1021b PMF |
755 | ret = ltt_channels_get_index_from_name(channel); |
756 | if (ret < 0) | |
757 | goto error_unregister_channel; | |
758 | entry->channel_id = ret; | |
759 | ret = ltt_channels_get_event_id(channel, name); | |
760 | if (ret < 0) | |
761 | goto error_unregister_channel; | |
762 | entry->event_id = ret; | |
763 | ret = 0; | |
f36c12ab | 764 | __ust_marker(metadata, core_marker_id, NULL, |
68c1021b PMF |
765 | "channel %s name %s event_id %hu " |
766 | "int #1u%zu long #1u%zu pointer #1u%zu " | |
767 | "size_t #1u%zu alignment #1u%u", | |
768 | channel, name, entry->event_id, | |
769 | sizeof(int), sizeof(long), sizeof(void *), | |
770 | sizeof(size_t), ltt_get_alignment()); | |
771 | } else if (format) { | |
772 | if (!entry->format) | |
b521931e | 773 | ret = ust_marker_set_format(entry, format); |
68c1021b PMF |
774 | else if (strcmp(entry->format, format)) |
775 | ret = -EPERM; | |
776 | if (ret) | |
777 | goto end; | |
778 | } | |
779 | ||
b521931e | 780 | old = ust_marker_entry_add_probe(entry, probe, probe_private); |
68c1021b PMF |
781 | if (IS_ERR(old)) { |
782 | ret = PTR_ERR(old); | |
783 | if (first_probe) | |
784 | goto error_unregister_channel; | |
785 | else | |
786 | goto end; | |
787 | } | |
b27f8e75 | 788 | unlock_ust_marker(); |
68c1021b | 789 | |
b521931e MD |
790 | /* Activate ust_marker if necessary */ |
791 | ust_marker_update_probes(); | |
68c1021b | 792 | |
fd0a1aea MD |
793 | if (old) { |
794 | synchronize_rcu(); | |
795 | free_old_closure(&old->rcu); | |
796 | } | |
797 | return ret; | |
68c1021b PMF |
798 | |
799 | error_unregister_channel: | |
800 | ret_err = ltt_channels_unregister(channel); | |
801 | WARN_ON(ret_err); | |
b521931e MD |
802 | error_remove_ust_marker: |
803 | ret_err = remove_ust_marker(channel, name); | |
68c1021b PMF |
804 | WARN_ON(ret_err); |
805 | end: | |
b27f8e75 | 806 | unlock_ust_marker(); |
68c1021b PMF |
807 | return ret; |
808 | } | |
68c1021b PMF |
809 | |
810 | /** | |
b521931e MD |
811 | * ust_marker_probe_unregister - Disconnect a probe from a ust_marker |
812 | * @channel: ust_marker channel | |
813 | * @name: ust_marker name | |
68c1021b PMF |
814 | * @probe: probe function pointer |
815 | * @probe_private: probe private data | |
816 | * | |
b521931e | 817 | * Returns the private data given to ust_marker_probe_register, or an ERR_PTR(). |
68c1021b PMF |
818 | * We do not need to call a synchronize_sched to make sure the probes have |
819 | * finished running before doing a module unload, because the module unload | |
820 | * itself uses stop_machine(), which insures that every preempt disabled section | |
821 | * have finished. | |
822 | */ | |
b521931e MD |
823 | int ust_marker_probe_unregister(const char *channel, const char *name, |
824 | ust_marker_probe_func *probe, void *probe_private) | |
68c1021b | 825 | { |
b521931e | 826 | struct ust_marker_entry *entry; |
fd0a1aea MD |
827 | struct ust_marker_probe_array *old; |
828 | int ret = 0; | |
68c1021b | 829 | |
b27f8e75 | 830 | lock_ust_marker(); |
b521931e | 831 | entry = get_ust_marker(channel, name); |
fd0a1aea MD |
832 | if (!entry) { |
833 | ret = -ENOENT; | |
68c1021b | 834 | goto end; |
fd0a1aea | 835 | } |
b521931e | 836 | old = ust_marker_entry_remove_probe(entry, probe, probe_private); |
b27f8e75 | 837 | unlock_ust_marker(); |
68c1021b | 838 | |
b521931e | 839 | ust_marker_update_probes(); |
68c1021b | 840 | |
fd0a1aea MD |
841 | if (old) { |
842 | synchronize_rcu(); | |
843 | free_old_closure(&old->rcu); | |
844 | } | |
845 | return ret; | |
846 | ||
68c1021b | 847 | end: |
b27f8e75 | 848 | unlock_ust_marker(); |
68c1021b PMF |
849 | return ret; |
850 | } | |
68c1021b | 851 | |
b521931e | 852 | static struct ust_marker_entry * |
fd0a1aea MD |
853 | get_ust_marker_from_private_data(ust_marker_probe_func *probe, |
854 | void *probe_private) | |
68c1021b | 855 | { |
b521931e | 856 | struct ust_marker_entry *entry; |
68c1021b | 857 | unsigned int i; |
10c56168 DG |
858 | struct cds_hlist_head *head; |
859 | struct cds_hlist_node *node; | |
68c1021b | 860 | |
5cfbb58f | 861 | for (i = 0; i < UST_MARKER_TABLE_SIZE; i++) { |
b521931e | 862 | head = &ust_marker_table[i]; |
10c56168 | 863 | cds_hlist_for_each_entry(entry, node, head, hlist) { |
68c1021b PMF |
864 | if (!entry->ptype) { |
865 | if (entry->single.func == probe | |
866 | && entry->single.probe_private | |
867 | == probe_private) | |
868 | return entry; | |
869 | } else { | |
fd0a1aea | 870 | struct ust_marker_probe_array *closure; |
68c1021b | 871 | closure = entry->multi; |
fd0a1aea MD |
872 | for (i = 0; closure->c[i].func; i++) { |
873 | if (closure->c[i].func == probe && | |
874 | closure->c[i].probe_private | |
68c1021b PMF |
875 | == probe_private) |
876 | return entry; | |
877 | } | |
878 | } | |
879 | } | |
880 | } | |
881 | return NULL; | |
882 | } | |
883 | ||
884 | /** | |
b521931e | 885 | * ust_marker_probe_unregister_private_data - Disconnect a probe from a ust_marker |
68c1021b PMF |
886 | * @probe: probe function |
887 | * @probe_private: probe private data | |
888 | * | |
889 | * Unregister a probe by providing the registered private data. | |
b521931e | 890 | * Only removes the first ust_marker found in hash table. |
68c1021b PMF |
891 | * Return 0 on success or error value. |
892 | * We do not need to call a synchronize_sched to make sure the probes have | |
893 | * finished running before doing a module unload, because the module unload | |
894 | * itself uses stop_machine(), which insures that every preempt disabled section | |
895 | * have finished. | |
896 | */ | |
b521931e | 897 | int ust_marker_probe_unregister_private_data(ust_marker_probe_func *probe, |
68c1021b PMF |
898 | void *probe_private) |
899 | { | |
b521931e | 900 | struct ust_marker_entry *entry; |
68c1021b | 901 | int ret = 0; |
fd0a1aea | 902 | struct ust_marker_probe_array *old; |
909bc43f | 903 | char *channel = NULL, *name = NULL; |
68c1021b | 904 | |
b27f8e75 | 905 | lock_ust_marker(); |
b521931e | 906 | entry = get_ust_marker_from_private_data(probe, probe_private); |
68c1021b PMF |
907 | if (!entry) { |
908 | ret = -ENOENT; | |
fd0a1aea | 909 | goto unlock; |
68c1021b | 910 | } |
b521931e | 911 | old = ust_marker_entry_remove_probe(entry, NULL, probe_private); |
909bc43f PMF |
912 | channel = strdup(entry->channel); |
913 | name = strdup(entry->name); | |
fd0a1aea MD |
914 | /* Ignore busy error message */ |
915 | remove_ust_marker(channel, name); | |
b27f8e75 | 916 | unlock_ust_marker(); |
68c1021b | 917 | |
b521931e | 918 | ust_marker_update_probes(); |
68c1021b | 919 | |
fd0a1aea MD |
920 | if (old) { |
921 | synchronize_rcu(); | |
922 | free_old_closure(&old->rcu); | |
923 | } | |
924 | goto end; | |
925 | ||
926 | unlock: | |
b27f8e75 | 927 | unlock_ust_marker(); |
fd0a1aea | 928 | end: |
909bc43f PMF |
929 | free(channel); |
930 | free(name); | |
68c1021b PMF |
931 | return ret; |
932 | } | |
68c1021b PMF |
933 | |
934 | /** | |
b521931e MD |
935 | * ust_marker_get_private_data - Get a ust_marker's probe private data |
936 | * @channel: ust_marker channel | |
937 | * @name: ust_marker name | |
68c1021b PMF |
938 | * @probe: probe to match |
939 | * @num: get the nth matching probe's private data | |
940 | * | |
941 | * Returns the nth private data pointer (starting from 0) matching, or an | |
942 | * ERR_PTR. | |
943 | * Returns the private data pointer, or an ERR_PTR. | |
944 | * The private data pointer should _only_ be dereferenced if the caller is the | |
945 | * owner of the data, or its content could vanish. This is mostly used to | |
946 | * confirm that a caller is the owner of a registered probe. | |
947 | */ | |
b521931e MD |
948 | void *ust_marker_get_private_data(const char *channel, const char *name, |
949 | ust_marker_probe_func *probe, int num) | |
68c1021b | 950 | { |
10c56168 DG |
951 | struct cds_hlist_head *head; |
952 | struct cds_hlist_node *node; | |
b521931e | 953 | struct ust_marker_entry *e; |
68c1021b PMF |
954 | size_t channel_len = strlen(channel) + 1; |
955 | size_t name_len = strlen(name) + 1; | |
956 | int i; | |
957 | u32 hash; | |
958 | ||
959 | hash = jhash(channel, channel_len-1, 0) ^ jhash(name, name_len-1, 0); | |
5cfbb58f | 960 | head = &ust_marker_table[hash & ((1 << UST_MARKER_HASH_BITS)-1)]; |
10c56168 | 961 | cds_hlist_for_each_entry(e, node, head, hlist) { |
68c1021b PMF |
962 | if (!strcmp(channel, e->channel) && !strcmp(name, e->name)) { |
963 | if (!e->ptype) { | |
964 | if (num == 0 && e->single.func == probe) | |
965 | return e->single.probe_private; | |
966 | } else { | |
fd0a1aea | 967 | struct ust_marker_probe_array *closure; |
68c1021b PMF |
968 | int match = 0; |
969 | closure = e->multi; | |
fd0a1aea MD |
970 | for (i = 0; closure->c[i].func; i++) { |
971 | if (closure->c[i].func != probe) | |
68c1021b PMF |
972 | continue; |
973 | if (match++ == num) | |
fd0a1aea | 974 | return closure->c[i].probe_private; |
68c1021b PMF |
975 | } |
976 | } | |
977 | break; | |
978 | } | |
979 | } | |
980 | return ERR_PTR(-ENOENT); | |
981 | } | |
68c1021b PMF |
982 | |
983 | /** | |
fd0a1aea MD |
984 | * ust_marker_get_iter_range - Get a next ust_marker iterator given a range. |
985 | * @ust_marker: current ust_marker (in), next ust_marker (out) | |
986 | * @begin: beginning of the range | |
987 | * @end: end of the range | |
68c1021b | 988 | * |
fd0a1aea MD |
989 | * Returns whether a next ust_marker has been found (1) or not (0). |
990 | * Will return the first ust_marker in the range if the input ust_marker is NULL. | |
991 | * Called with markers mutex held. | |
68c1021b | 992 | */ |
fd0a1aea MD |
993 | static |
994 | int ust_marker_get_iter_range(struct ust_marker * const **ust_marker, | |
995 | struct ust_marker * const *begin, | |
996 | struct ust_marker * const *end) | |
997 | { | |
998 | if (!*ust_marker && begin != end) | |
999 | *ust_marker = begin; | |
1000 | while (*ust_marker >= begin && *ust_marker < end) { | |
1001 | if (!**ust_marker) | |
1002 | (*ust_marker)++; /* skip dummy */ | |
1003 | else | |
1004 | return 1; | |
1005 | } | |
1006 | return 0; | |
1007 | } | |
68c1021b | 1008 | |
772030fe PMF |
1009 | /* |
1010 | * Returns 0 if current not found. | |
1011 | * Returns 1 if current found. | |
fd0a1aea | 1012 | * Called with markers mutex held. |
772030fe | 1013 | */ |
fd0a1aea | 1014 | static |
b521931e | 1015 | int lib_get_iter_ust_marker(struct ust_marker_iter *iter) |
772030fe | 1016 | { |
b521931e | 1017 | struct ust_marker_lib *iter_lib; |
772030fe PMF |
1018 | int found = 0; |
1019 | ||
b521931e | 1020 | cds_list_for_each_entry(iter_lib, &ust_marker_libs, list) { |
772030fe PMF |
1021 | if (iter_lib < iter->lib) |
1022 | continue; | |
1023 | else if (iter_lib > iter->lib) | |
b521931e MD |
1024 | iter->ust_marker = NULL; |
1025 | found = ust_marker_get_iter_range(&iter->ust_marker, | |
1026 | iter_lib->ust_marker_start, | |
1027 | iter_lib->ust_marker_start + iter_lib->ust_marker_count); | |
772030fe PMF |
1028 | if (found) { |
1029 | iter->lib = iter_lib; | |
1030 | break; | |
1031 | } | |
1032 | } | |
772030fe PMF |
1033 | return found; |
1034 | } | |
1035 | ||
fd0a1aea | 1036 | /* Called with markers mutex held. */ |
b521931e | 1037 | static void ust_marker_get_iter(struct ust_marker_iter *iter) |
68c1021b PMF |
1038 | { |
1039 | int found = 0; | |
1040 | ||
b521931e | 1041 | found = lib_get_iter_ust_marker(iter); |
68c1021b | 1042 | if (!found) |
b521931e | 1043 | ust_marker_iter_reset(iter); |
68c1021b PMF |
1044 | } |
1045 | ||
b521931e | 1046 | void ust_marker_iter_start(struct ust_marker_iter *iter) |
68c1021b | 1047 | { |
b27f8e75 | 1048 | lock_ust_marker(); |
b521931e | 1049 | ust_marker_get_iter(iter); |
68c1021b | 1050 | } |
68c1021b | 1051 | |
fd0a1aea | 1052 | /* Called with markers mutex held. */ |
b521931e | 1053 | void ust_marker_iter_next(struct ust_marker_iter *iter) |
68c1021b | 1054 | { |
b521931e | 1055 | iter->ust_marker++; |
68c1021b | 1056 | /* |
b521931e MD |
1057 | * iter->ust_marker may be invalid because we blindly incremented it. |
1058 | * Make sure it is valid by marshalling on the ust_marker, getting the | |
1059 | * ust_marker from following modules if necessary. | |
68c1021b | 1060 | */ |
b521931e | 1061 | ust_marker_get_iter(iter); |
68c1021b | 1062 | } |
68c1021b | 1063 | |
b521931e | 1064 | void ust_marker_iter_stop(struct ust_marker_iter *iter) |
68c1021b | 1065 | { |
b27f8e75 | 1066 | unlock_ust_marker(); |
68c1021b | 1067 | } |
68c1021b | 1068 | |
b521931e | 1069 | void ust_marker_iter_reset(struct ust_marker_iter *iter) |
68c1021b | 1070 | { |
98963de4 | 1071 | iter->lib = NULL; |
b521931e | 1072 | iter->ust_marker = NULL; |
68c1021b | 1073 | } |
68c1021b | 1074 | |
b521931e | 1075 | void ltt_dump_ust_marker_state(struct ust_trace *trace) |
9c67dc50 | 1076 | { |
b521931e | 1077 | struct ust_marker_entry *entry; |
9c67dc50 | 1078 | struct ltt_probe_private_data call_data; |
10c56168 DG |
1079 | struct cds_hlist_head *head; |
1080 | struct cds_hlist_node *node; | |
48454c95 | 1081 | unsigned int i; |
9c67dc50 | 1082 | |
b27f8e75 | 1083 | lock_ust_marker(); |
9c67dc50 PMF |
1084 | call_data.trace = trace; |
1085 | call_data.serializer = NULL; | |
1086 | ||
5cfbb58f | 1087 | for (i = 0; i < UST_MARKER_TABLE_SIZE; i++) { |
b521931e | 1088 | head = &ust_marker_table[i]; |
10c56168 | 1089 | cds_hlist_for_each_entry(entry, node, head, hlist) { |
f36c12ab | 1090 | __ust_marker(metadata, core_marker_id, |
9c67dc50 | 1091 | &call_data, |
48454c95 PMF |
1092 | "channel %s name %s event_id %hu " |
1093 | "int #1u%zu long #1u%zu pointer #1u%zu " | |
1094 | "size_t #1u%zu alignment #1u%u", | |
1095 | entry->channel, | |
1096 | entry->name, | |
1097 | entry->event_id, | |
1098 | sizeof(int), sizeof(long), | |
1099 | sizeof(void *), sizeof(size_t), | |
1100 | ltt_get_alignment()); | |
1101 | if (entry->format) | |
f36c12ab | 1102 | __ust_marker(metadata, |
48454c95 PMF |
1103 | core_marker_format, |
1104 | &call_data, | |
1105 | "channel %s name %s format %s", | |
1106 | entry->channel, | |
1107 | entry->name, | |
1108 | entry->format); | |
1109 | } | |
9c67dc50 | 1110 | } |
b27f8e75 | 1111 | unlock_ust_marker(); |
9c67dc50 | 1112 | } |
98963de4 | 1113 | |
b521931e | 1114 | void ust_marker_set_new_ust_marker_cb(void (*cb)(struct ust_marker *)) |
20b37a31 | 1115 | { |
b521931e | 1116 | new_ust_marker_cb = cb; |
20b37a31 PMF |
1117 | } |
1118 | ||
fd0a1aea MD |
1119 | static void new_ust_marker(struct ust_marker * const *start, |
1120 | struct ust_marker * const *end) | |
20b37a31 | 1121 | { |
b521931e MD |
1122 | if (new_ust_marker_cb) { |
1123 | struct ust_marker * const *m; | |
f08ebbe2 | 1124 | |
b27f8e75 | 1125 | for (m = start; m < end; m++) { |
f08ebbe2 | 1126 | if (*m) |
b521931e | 1127 | new_ust_marker_cb(*m); |
20b37a31 PMF |
1128 | } |
1129 | } | |
1130 | } | |
1131 | ||
fd0a1aea MD |
1132 | int ust_marker_register_lib(struct ust_marker * const *ust_marker_start, |
1133 | int ust_marker_count) | |
98963de4 | 1134 | { |
b521931e | 1135 | struct ust_marker_lib *pl, *iter; |
98963de4 | 1136 | |
b521931e | 1137 | pl = (struct ust_marker_lib *) zmalloc(sizeof(struct ust_marker_lib)); |
98963de4 | 1138 | |
b521931e MD |
1139 | pl->ust_marker_start = ust_marker_start; |
1140 | pl->ust_marker_count = ust_marker_count; | |
98963de4 | 1141 | |
b521931e | 1142 | lock_ust_marker(); |
b467f7a7 MD |
1143 | |
1144 | /* | |
1145 | * We sort the libs by struct lib pointer address. | |
1146 | */ | |
b521931e | 1147 | cds_list_for_each_entry_reverse(iter, &ust_marker_libs, list) { |
b467f7a7 MD |
1148 | BUG_ON(iter == pl); /* Should never be in the list twice */ |
1149 | if (iter < pl) { | |
1150 | /* We belong to the location right after iter. */ | |
1151 | cds_list_add(&pl->list, &iter->list); | |
1152 | goto lib_added; | |
1153 | } | |
1154 | } | |
1155 | /* We should be added at the head of the list */ | |
b521931e | 1156 | cds_list_add(&pl->list, &ust_marker_libs); |
b467f7a7 | 1157 | lib_added: |
b521931e | 1158 | unlock_ust_marker(); |
98963de4 | 1159 | |
b521931e | 1160 | new_ust_marker(ust_marker_start, ust_marker_start + ust_marker_count); |
20b37a31 | 1161 | |
fd0a1aea | 1162 | /* TODO: update just the loaded lib */ |
b521931e | 1163 | lib_update_ust_marker(); |
4db647c5 | 1164 | |
b521931e | 1165 | DBG("just registered a ust_marker section from %p and having %d ust_marker (minus dummy ust_marker)", ust_marker_start, ust_marker_count); |
98963de4 PMF |
1166 | |
1167 | return 0; | |
1168 | } | |
c463904d | 1169 | |
b521931e | 1170 | int ust_marker_unregister_lib(struct ust_marker * const *ust_marker_start) |
0b5207fa | 1171 | { |
b521931e | 1172 | struct ust_marker_lib *lib; |
24b6668c | 1173 | |
b521931e | 1174 | lock_ust_marker(); |
b521931e MD |
1175 | cds_list_for_each_entry(lib, &ust_marker_libs, list) { |
1176 | if(lib->ust_marker_start == ust_marker_start) { | |
1177 | struct ust_marker_lib *lib2free = lib; | |
0222e121 | 1178 | cds_list_del(&lib->list); |
24b6668c PMF |
1179 | free(lib2free); |
1180 | break; | |
1181 | } | |
1182 | } | |
b521931e | 1183 | unlock_ust_marker(); |
24b6668c | 1184 | |
0b5207fa PMF |
1185 | return 0; |
1186 | } | |
1187 | ||
b521931e | 1188 | void __attribute__((constructor)) init_ust_marker(void) |
c463904d | 1189 | { |
900e307e | 1190 | if (!initialized) { |
b27f8e75 | 1191 | init_tracepoint(); |
b521931e MD |
1192 | ust_marker_register_lib(__start___ust_marker_ptrs, |
1193 | __stop___ust_marker_ptrs | |
1194 | - __start___ust_marker_ptrs); | |
4db647c5 PMF |
1195 | initialized = 1; |
1196 | } | |
c463904d | 1197 | } |
24b6668c | 1198 | |
b521931e | 1199 | void __attribute__((destructor)) destroy_ust_marker(void) |
24b6668c | 1200 | { |
b521931e | 1201 | ust_marker_unregister_lib(__start___ust_marker_ptrs); |
24b6668c | 1202 | } |