| 1 | /* |
| 2 | * ltt-probes.c |
| 3 | * |
| 4 | * Holds LTTng probes registry. |
| 5 | * |
| 6 | * Copyright 2010-2012 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 7 | * |
| 8 | * This library is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU Lesser General Public |
| 10 | * License as published by the Free Software Foundation; only |
| 11 | * version 2.1 of the License. |
| 12 | * |
| 13 | * This library is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 16 | * Lesser General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU Lesser General Public |
| 19 | * License along with this library; if not, write to the Free Software |
| 20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 21 | */ |
| 22 | |
| 23 | #include <string.h> |
| 24 | #include <errno.h> |
| 25 | #include <urcu/list.h> |
| 26 | #include <urcu/hlist.h> |
| 27 | #include <lttng/ust-events.h> |
| 28 | #include <lttng/tracepoint.h> |
| 29 | #include "tracepoint-internal.h" |
| 30 | #include <assert.h> |
| 31 | #include <helper.h> |
| 32 | #include <ctype.h> |
| 33 | |
| 34 | #include "ltt-tracer-core.h" |
| 35 | #include "jhash.h" |
| 36 | #include "error.h" |
| 37 | |
| 38 | /* |
| 39 | * probe list is protected by ust_lock()/ust_unlock(). |
| 40 | */ |
| 41 | static CDS_LIST_HEAD(probe_list); |
| 42 | |
| 43 | static |
| 44 | const struct lttng_probe_desc *find_provider(const char *provider) |
| 45 | { |
| 46 | struct lttng_probe_desc *iter; |
| 47 | |
| 48 | cds_list_for_each_entry(iter, &probe_list, head) { |
| 49 | if (!strcmp(iter->provider, provider)) |
| 50 | return iter; |
| 51 | } |
| 52 | return NULL; |
| 53 | } |
| 54 | |
| 55 | static |
| 56 | const struct lttng_event_desc *find_event(const char *name) |
| 57 | { |
| 58 | struct lttng_probe_desc *probe_desc; |
| 59 | int i; |
| 60 | |
| 61 | cds_list_for_each_entry(probe_desc, &probe_list, head) { |
| 62 | for (i = 0; i < probe_desc->nr_events; i++) { |
| 63 | if (!strncmp(probe_desc->event_desc[i]->name, name, |
| 64 | LTTNG_UST_SYM_NAME_LEN - 1)) |
| 65 | return probe_desc->event_desc[i]; |
| 66 | } |
| 67 | } |
| 68 | return NULL; |
| 69 | } |
| 70 | |
| 71 | int ltt_probe_register(struct lttng_probe_desc *desc) |
| 72 | { |
| 73 | struct lttng_probe_desc *iter; |
| 74 | int ret = 0; |
| 75 | int i; |
| 76 | |
| 77 | ust_lock(); |
| 78 | if (find_provider(desc->provider)) { |
| 79 | ret = -EEXIST; |
| 80 | goto end; |
| 81 | } |
| 82 | /* |
| 83 | * TODO: This is O(N^2). Turn into a hash table when probe registration |
| 84 | * overhead becomes an issue. |
| 85 | */ |
| 86 | for (i = 0; i < desc->nr_events; i++) { |
| 87 | if (find_event(desc->event_desc[i]->name)) { |
| 88 | ret = -EEXIST; |
| 89 | goto end; |
| 90 | } |
| 91 | } |
| 92 | |
| 93 | /* |
| 94 | * We sort the providers by struct lttng_probe_desc pointer |
| 95 | * address. |
| 96 | */ |
| 97 | cds_list_for_each_entry_reverse(iter, &probe_list, head) { |
| 98 | BUG_ON(iter == desc); /* Should never be in the list twice */ |
| 99 | if (iter < desc) { |
| 100 | /* We belong to the location right after iter. */ |
| 101 | cds_list_add(&desc->head, &iter->head); |
| 102 | goto desc_added; |
| 103 | } |
| 104 | } |
| 105 | /* We should be added at the head of the list */ |
| 106 | cds_list_add(&desc->head, &probe_list); |
| 107 | desc_added: |
| 108 | DBG("just registered probe %s containing %u events", |
| 109 | desc->provider, desc->nr_events); |
| 110 | /* |
| 111 | * fix the events awaiting probe load. |
| 112 | */ |
| 113 | for (i = 0; i < desc->nr_events; i++) { |
| 114 | const struct lttng_event_desc *ed; |
| 115 | |
| 116 | ed = desc->event_desc[i]; |
| 117 | DBG("Registered event probe \"%s\" with signature \"%s\"", |
| 118 | ed->name, ed->signature); |
| 119 | ret = pending_probe_fix_events(ed); |
| 120 | assert(!ret); |
| 121 | } |
| 122 | end: |
| 123 | ust_unlock(); |
| 124 | return ret; |
| 125 | } |
| 126 | |
| 127 | void ltt_probe_unregister(struct lttng_probe_desc *desc) |
| 128 | { |
| 129 | ust_lock(); |
| 130 | cds_list_del(&desc->head); |
| 131 | DBG("just unregistered probe %s", desc->provider); |
| 132 | ust_unlock(); |
| 133 | } |
| 134 | |
| 135 | /* |
| 136 | * called with UST lock held. |
| 137 | */ |
| 138 | const struct lttng_event_desc *ltt_event_get(const char *name) |
| 139 | { |
| 140 | const struct lttng_event_desc *event; |
| 141 | |
| 142 | event = find_event(name); |
| 143 | if (!event) |
| 144 | return NULL; |
| 145 | return event; |
| 146 | } |
| 147 | |
| 148 | void ltt_event_put(const struct lttng_event_desc *event) |
| 149 | { |
| 150 | } |
| 151 | |
| 152 | void ltt_probes_prune_event_list(struct lttng_ust_tracepoint_list *list) |
| 153 | { |
| 154 | struct tp_list_entry *list_entry, *tmp; |
| 155 | |
| 156 | cds_list_for_each_entry_safe(list_entry, tmp, &list->head, head) { |
| 157 | cds_list_del(&list_entry->head); |
| 158 | free(list_entry); |
| 159 | } |
| 160 | } |
| 161 | |
| 162 | /* |
| 163 | * called with UST lock held. |
| 164 | */ |
| 165 | int ltt_probes_get_event_list(struct lttng_ust_tracepoint_list *list) |
| 166 | { |
| 167 | struct lttng_probe_desc *probe_desc; |
| 168 | int i; |
| 169 | |
| 170 | CDS_INIT_LIST_HEAD(&list->head); |
| 171 | cds_list_for_each_entry(probe_desc, &probe_list, head) { |
| 172 | for (i = 0; i < probe_desc->nr_events; i++) { |
| 173 | struct tp_list_entry *list_entry; |
| 174 | |
| 175 | list_entry = zmalloc(sizeof(*list_entry)); |
| 176 | if (!list_entry) |
| 177 | goto err_nomem; |
| 178 | cds_list_add(&list_entry->head, &list->head); |
| 179 | strncpy(list_entry->tp.name, |
| 180 | probe_desc->event_desc[i]->name, |
| 181 | LTTNG_UST_SYM_NAME_LEN); |
| 182 | list_entry->tp.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0'; |
| 183 | if (!probe_desc->event_desc[i]->loglevel) { |
| 184 | list_entry->tp.loglevel = TRACE_DEFAULT; |
| 185 | } else { |
| 186 | list_entry->tp.loglevel = *(*probe_desc->event_desc[i]->loglevel); |
| 187 | } |
| 188 | } |
| 189 | } |
| 190 | if (cds_list_empty(&list->head)) |
| 191 | list->iter = NULL; |
| 192 | else |
| 193 | list->iter = |
| 194 | cds_list_first_entry(&list->head, struct tp_list_entry, head); |
| 195 | return 0; |
| 196 | |
| 197 | err_nomem: |
| 198 | ltt_probes_prune_event_list(list); |
| 199 | return -ENOMEM; |
| 200 | } |
| 201 | |
| 202 | /* |
| 203 | * Return current iteration position, advance internal iterator to next. |
| 204 | * Return NULL if end of list. |
| 205 | */ |
| 206 | struct lttng_ust_tracepoint_iter * |
| 207 | lttng_ust_tracepoint_list_get_iter_next(struct lttng_ust_tracepoint_list *list) |
| 208 | { |
| 209 | struct tp_list_entry *entry; |
| 210 | |
| 211 | if (!list->iter) |
| 212 | return NULL; |
| 213 | entry = list->iter; |
| 214 | if (entry->head.next == &list->head) |
| 215 | list->iter = NULL; |
| 216 | else |
| 217 | list->iter = cds_list_entry(entry->head.next, |
| 218 | struct tp_list_entry, head); |
| 219 | return &entry->tp; |
| 220 | } |
| 221 | |
| 222 | /* |
| 223 | * marshall all probes/all events and create those that fit the |
| 224 | * wildcard. Add them to the events list as created. |
| 225 | */ |
| 226 | void ltt_probes_create_wildcard_events(struct wildcard_entry *entry, |
| 227 | struct session_wildcard *wildcard) |
| 228 | { |
| 229 | struct lttng_probe_desc *probe_desc; |
| 230 | struct lttng_ust_event event_param; |
| 231 | int i; |
| 232 | |
| 233 | cds_list_for_each_entry(probe_desc, &probe_list, head) { |
| 234 | for (i = 0; i < probe_desc->nr_events; i++) { |
| 235 | const struct lttng_event_desc *event_desc; |
| 236 | int match = 0; |
| 237 | |
| 238 | event_desc = probe_desc->event_desc[i]; |
| 239 | /* compare excluding final '*' */ |
| 240 | assert(strlen(entry->name) > 0); |
| 241 | if (strcmp(event_desc->name, "lttng_ust:metadata") |
| 242 | && (strlen(entry->name) == 1 |
| 243 | || !strncmp(event_desc->name, entry->name, |
| 244 | strlen(entry->name) - 1))) { |
| 245 | if (ltt_loglevel_match(event_desc, |
| 246 | entry->loglevel_type, |
| 247 | entry->loglevel)) { |
| 248 | match = 1; |
| 249 | } |
| 250 | } |
| 251 | if (match) { |
| 252 | struct ltt_event *ev; |
| 253 | int ret; |
| 254 | |
| 255 | memcpy(&event_param, &wildcard->event_param, |
| 256 | sizeof(event_param)); |
| 257 | memcpy(event_param.name, |
| 258 | event_desc->name, |
| 259 | sizeof(event_param.name)); |
| 260 | /* create event */ |
| 261 | ret = ltt_event_create(wildcard->chan, |
| 262 | &event_param, NULL, |
| 263 | &ev); |
| 264 | if (ret) { |
| 265 | DBG("Error creating event"); |
| 266 | continue; |
| 267 | } |
| 268 | cds_list_add(&ev->wildcard_list, |
| 269 | &wildcard->events); |
| 270 | } |
| 271 | } |
| 272 | } |
| 273 | } |
| 274 | |