| 1 | /* |
| 2 | * ltt-probes.c |
| 3 | * |
| 4 | * Copyright 2010 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 5 | * |
| 6 | * Holds LTTng probes registry. |
| 7 | * |
| 8 | * Dual LGPL v2.1/GPL v2 license. |
| 9 | */ |
| 10 | |
| 11 | #include <string.h> |
| 12 | #include <errno.h> |
| 13 | #include <urcu/list.h> |
| 14 | #include <urcu/hlist.h> |
| 15 | #include <lttng/ust-events.h> |
| 16 | #include <lttng/tracepoint.h> |
| 17 | #include "tracepoint-internal.h" |
| 18 | #include <assert.h> |
| 19 | #include <helper.h> |
| 20 | #include <ctype.h> |
| 21 | |
| 22 | #include "ltt-tracer-core.h" |
| 23 | #include "jhash.h" |
| 24 | #include "error.h" |
| 25 | |
| 26 | /* |
| 27 | * probe list is protected by ust_lock()/ust_unlock(). |
| 28 | */ |
| 29 | static CDS_LIST_HEAD(probe_list); |
| 30 | |
| 31 | static |
| 32 | const struct lttng_probe_desc *find_provider(const char *provider) |
| 33 | { |
| 34 | struct lttng_probe_desc *iter; |
| 35 | |
| 36 | cds_list_for_each_entry(iter, &probe_list, head) { |
| 37 | if (!strcmp(iter->provider, provider)) |
| 38 | return iter; |
| 39 | } |
| 40 | return NULL; |
| 41 | } |
| 42 | |
| 43 | static |
| 44 | const struct lttng_event_desc *find_event(const char *name) |
| 45 | { |
| 46 | struct lttng_probe_desc *probe_desc; |
| 47 | int i; |
| 48 | |
| 49 | cds_list_for_each_entry(probe_desc, &probe_list, head) { |
| 50 | for (i = 0; i < probe_desc->nr_events; i++) { |
| 51 | if (!strncmp(probe_desc->event_desc[i]->name, name, |
| 52 | LTTNG_UST_SYM_NAME_LEN - 1)) |
| 53 | return probe_desc->event_desc[i]; |
| 54 | } |
| 55 | } |
| 56 | return NULL; |
| 57 | } |
| 58 | |
| 59 | int ltt_probe_register(struct lttng_probe_desc *desc) |
| 60 | { |
| 61 | struct lttng_probe_desc *iter; |
| 62 | int ret = 0; |
| 63 | int i; |
| 64 | |
| 65 | ust_lock(); |
| 66 | if (find_provider(desc->provider)) { |
| 67 | ret = -EEXIST; |
| 68 | goto end; |
| 69 | } |
| 70 | /* |
| 71 | * TODO: This is O(N^2). Turn into a hash table when probe registration |
| 72 | * overhead becomes an issue. |
| 73 | */ |
| 74 | for (i = 0; i < desc->nr_events; i++) { |
| 75 | if (find_event(desc->event_desc[i]->name)) { |
| 76 | ret = -EEXIST; |
| 77 | goto end; |
| 78 | } |
| 79 | } |
| 80 | |
| 81 | /* |
| 82 | * We sort the providers by struct lttng_probe_desc pointer |
| 83 | * address. |
| 84 | */ |
| 85 | cds_list_for_each_entry_reverse(iter, &probe_list, head) { |
| 86 | BUG_ON(iter == desc); /* Should never be in the list twice */ |
| 87 | if (iter < desc) { |
| 88 | /* We belong to the location right after iter. */ |
| 89 | cds_list_add(&desc->head, &iter->head); |
| 90 | goto desc_added; |
| 91 | } |
| 92 | } |
| 93 | /* We should be added at the head of the list */ |
| 94 | cds_list_add(&desc->head, &probe_list); |
| 95 | desc_added: |
| 96 | DBG("just registered probe %s containing %u events", |
| 97 | desc->provider, desc->nr_events); |
| 98 | /* |
| 99 | * fix the events awaiting probe load. |
| 100 | */ |
| 101 | for (i = 0; i < desc->nr_events; i++) { |
| 102 | ret = pending_probe_fix_events(desc->event_desc[i]); |
| 103 | assert(!ret); |
| 104 | } |
| 105 | end: |
| 106 | ust_unlock(); |
| 107 | return ret; |
| 108 | } |
| 109 | |
| 110 | void ltt_probe_unregister(struct lttng_probe_desc *desc) |
| 111 | { |
| 112 | ust_lock(); |
| 113 | cds_list_del(&desc->head); |
| 114 | DBG("just unregistered probe %s", desc->provider); |
| 115 | ust_unlock(); |
| 116 | } |
| 117 | |
| 118 | /* |
| 119 | * called with UST lock held. |
| 120 | */ |
| 121 | const struct lttng_event_desc *ltt_event_get(const char *name) |
| 122 | { |
| 123 | const struct lttng_event_desc *event; |
| 124 | |
| 125 | event = find_event(name); |
| 126 | if (!event) |
| 127 | return NULL; |
| 128 | return event; |
| 129 | } |
| 130 | |
| 131 | void ltt_event_put(const struct lttng_event_desc *event) |
| 132 | { |
| 133 | } |
| 134 | |
| 135 | void ltt_probes_prune_event_list(struct lttng_ust_tracepoint_list *list) |
| 136 | { |
| 137 | struct tp_list_entry *list_entry, *tmp; |
| 138 | |
| 139 | cds_list_for_each_entry_safe(list_entry, tmp, &list->head, head) { |
| 140 | cds_list_del(&list_entry->head); |
| 141 | free(list_entry); |
| 142 | } |
| 143 | } |
| 144 | |
| 145 | /* |
| 146 | * called with UST lock held. |
| 147 | */ |
| 148 | int ltt_probes_get_event_list(struct lttng_ust_tracepoint_list *list) |
| 149 | { |
| 150 | struct lttng_probe_desc *probe_desc; |
| 151 | int i; |
| 152 | |
| 153 | CDS_INIT_LIST_HEAD(&list->head); |
| 154 | cds_list_for_each_entry(probe_desc, &probe_list, head) { |
| 155 | for (i = 0; i < probe_desc->nr_events; i++) { |
| 156 | struct tp_list_entry *list_entry; |
| 157 | |
| 158 | list_entry = zmalloc(sizeof(*list_entry)); |
| 159 | if (!list_entry) |
| 160 | goto err_nomem; |
| 161 | cds_list_add(&list_entry->head, &list->head); |
| 162 | strncpy(list_entry->tp.name, |
| 163 | probe_desc->event_desc[i]->name, |
| 164 | LTTNG_UST_SYM_NAME_LEN); |
| 165 | list_entry->tp.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0'; |
| 166 | if (!probe_desc->event_desc[i]->loglevel) { |
| 167 | list_entry->tp.loglevel = TRACE_DEFAULT; |
| 168 | } else { |
| 169 | list_entry->tp.loglevel = *(*probe_desc->event_desc[i]->loglevel); |
| 170 | } |
| 171 | } |
| 172 | } |
| 173 | if (cds_list_empty(&list->head)) |
| 174 | list->iter = NULL; |
| 175 | else |
| 176 | list->iter = |
| 177 | cds_list_first_entry(&list->head, struct tp_list_entry, head); |
| 178 | return 0; |
| 179 | |
| 180 | err_nomem: |
| 181 | ltt_probes_prune_event_list(list); |
| 182 | return -ENOMEM; |
| 183 | } |
| 184 | |
| 185 | /* |
| 186 | * Return current iteration position, advance internal iterator to next. |
| 187 | * Return NULL if end of list. |
| 188 | */ |
| 189 | struct lttng_ust_tracepoint_iter * |
| 190 | lttng_ust_tracepoint_list_get_iter_next(struct lttng_ust_tracepoint_list *list) |
| 191 | { |
| 192 | struct tp_list_entry *entry; |
| 193 | |
| 194 | if (!list->iter) |
| 195 | return NULL; |
| 196 | entry = list->iter; |
| 197 | if (entry->head.next == &list->head) |
| 198 | list->iter = NULL; |
| 199 | else |
| 200 | list->iter = cds_list_entry(entry->head.next, |
| 201 | struct tp_list_entry, head); |
| 202 | return &entry->tp; |
| 203 | } |
| 204 | |
| 205 | /* |
| 206 | * marshall all probes/all events and create those that fit the |
| 207 | * wildcard. Add them to the events list as created. |
| 208 | */ |
| 209 | void ltt_probes_create_wildcard_events(struct wildcard_entry *entry, |
| 210 | struct session_wildcard *wildcard) |
| 211 | { |
| 212 | struct lttng_probe_desc *probe_desc; |
| 213 | struct lttng_ust_event event_param; |
| 214 | int i; |
| 215 | |
| 216 | cds_list_for_each_entry(probe_desc, &probe_list, head) { |
| 217 | for (i = 0; i < probe_desc->nr_events; i++) { |
| 218 | const struct lttng_event_desc *event_desc; |
| 219 | int match = 0; |
| 220 | |
| 221 | event_desc = probe_desc->event_desc[i]; |
| 222 | /* compare excluding final '*' */ |
| 223 | assert(strlen(entry->name) > 0); |
| 224 | if (strcmp(event_desc->name, "lttng_ust:metadata") |
| 225 | && (strlen(entry->name) == 1 |
| 226 | || !strncmp(event_desc->name, entry->name, |
| 227 | strlen(entry->name) - 1))) { |
| 228 | if (ltt_loglevel_match(event_desc, |
| 229 | entry->loglevel_type, |
| 230 | entry->loglevel)) { |
| 231 | match = 1; |
| 232 | } |
| 233 | } |
| 234 | if (match) { |
| 235 | struct ltt_event *ev; |
| 236 | int ret; |
| 237 | |
| 238 | memcpy(&event_param, &wildcard->event_param, |
| 239 | sizeof(event_param)); |
| 240 | memcpy(event_param.name, |
| 241 | event_desc->name, |
| 242 | sizeof(event_param.name)); |
| 243 | /* create event */ |
| 244 | ret = ltt_event_create(wildcard->chan, |
| 245 | &event_param, NULL, |
| 246 | &ev); |
| 247 | if (ret) { |
| 248 | DBG("Error creating event"); |
| 249 | continue; |
| 250 | } |
| 251 | cds_list_add(&ev->wildcard_list, |
| 252 | &wildcard->events); |
| 253 | } |
| 254 | } |
| 255 | } |
| 256 | } |
| 257 | |