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53569322 | 1 | /* |
c0c0989a | 2 | * SPDX-License-Identifier: LGPL-2.1-only |
53569322 MD |
3 | * |
4 | * Copyright (C) 2016 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
5 | * | |
c0c0989a | 6 | * LTTng UST application context provider. |
53569322 MD |
7 | */ |
8 | ||
3fbec7dc | 9 | #define _LGPL_SOURCE |
b4051ad8 | 10 | #include <stddef.h> |
fb31eb73 | 11 | #include <stdint.h> |
53569322 MD |
12 | #include <sys/types.h> |
13 | #include <unistd.h> | |
fb31eb73 | 14 | |
ae4b659d | 15 | #include <ust-context-provider.h> |
d8d2416d | 16 | |
fc80554e | 17 | #include "context-internal.h" |
53569322 MD |
18 | #include "lttng-tracer-core.h" |
19 | #include "jhash.h" | |
d8d2416d | 20 | #include "context-provider-internal.h" |
864a1eda | 21 | #include <ust-helper.h> |
53569322 | 22 | |
4e48b5d2 MD |
23 | struct lttng_ust_registered_context_provider { |
24 | const struct lttng_ust_context_provider *provider; | |
25 | ||
26 | struct cds_hlist_node node; | |
27 | }; | |
28 | ||
53569322 MD |
29 | #define CONTEXT_PROVIDER_HT_BITS 12 |
30 | #define CONTEXT_PROVIDER_HT_SIZE (1U << CONTEXT_PROVIDER_HT_BITS) | |
31 | struct context_provider_ht { | |
32 | struct cds_hlist_head table[CONTEXT_PROVIDER_HT_SIZE]; | |
33 | }; | |
34 | ||
35 | static struct context_provider_ht context_provider_ht; | |
36 | ||
4e48b5d2 | 37 | static const struct lttng_ust_context_provider * |
53569322 MD |
38 | lookup_provider_by_name(const char *name) |
39 | { | |
40 | struct cds_hlist_head *head; | |
41 | struct cds_hlist_node *node; | |
4e48b5d2 | 42 | struct lttng_ust_registered_context_provider *reg_provider; |
53569322 MD |
43 | uint32_t hash; |
44 | const char *end; | |
45 | size_t len; | |
46 | ||
47 | /* Lookup using everything before first ':' as key. */ | |
48 | end = strchr(name, ':'); | |
49 | if (end) | |
50 | len = end - name; | |
51 | else | |
52 | len = strlen(name); | |
53 | hash = jhash(name, len, 0); | |
54 | head = &context_provider_ht.table[hash & (CONTEXT_PROVIDER_HT_SIZE - 1)]; | |
4e48b5d2 MD |
55 | cds_hlist_for_each_entry(reg_provider, node, head, node) { |
56 | if (!strncmp(reg_provider->provider->name, name, len)) | |
57 | return reg_provider->provider; | |
53569322 MD |
58 | } |
59 | return NULL; | |
60 | } | |
61 | ||
4e48b5d2 | 62 | struct lttng_ust_registered_context_provider *lttng_ust_context_provider_register(struct lttng_ust_context_provider *provider) |
53569322 | 63 | { |
4e48b5d2 | 64 | struct lttng_ust_registered_context_provider *reg_provider = NULL; |
53569322 MD |
65 | struct cds_hlist_head *head; |
66 | size_t name_len = strlen(provider->name); | |
67 | uint32_t hash; | |
53569322 | 68 | |
c362addf MD |
69 | lttng_ust_fixup_tls(); |
70 | ||
53569322 | 71 | /* Provider name starts with "$app.". */ |
fe94775b | 72 | if (strncmp("$app.", provider->name, strlen("$app.")) != 0) |
4e48b5d2 | 73 | return NULL; |
8b05d0d4 | 74 | /* Provider name cannot contain a colon character. */ |
53569322 | 75 | if (strchr(provider->name, ':')) |
4e48b5d2 MD |
76 | return NULL; |
77 | if (ust_lock()) | |
53569322 | 78 | goto end; |
4e48b5d2 | 79 | if (lookup_provider_by_name(provider->name)) |
53569322 | 80 | goto end; |
4e48b5d2 MD |
81 | reg_provider = zmalloc(sizeof(struct lttng_ust_registered_context_provider)); |
82 | if (!reg_provider) | |
83 | goto end; | |
84 | reg_provider->provider = provider; | |
53569322 MD |
85 | hash = jhash(provider->name, name_len, 0); |
86 | head = &context_provider_ht.table[hash & (CONTEXT_PROVIDER_HT_SIZE - 1)]; | |
4e48b5d2 | 87 | cds_hlist_add_head(®_provider->node, head); |
d8d2416d | 88 | |
53569322 MD |
89 | lttng_ust_context_set_session_provider(provider->name, |
90 | provider->get_size, provider->record, | |
4e48b5d2 | 91 | provider->get_value, provider->priv); |
d8d2416d FD |
92 | |
93 | lttng_ust_context_set_event_notifier_group_provider(provider->name, | |
94 | provider->get_size, provider->record, | |
4e48b5d2 | 95 | provider->get_value, provider->priv); |
53569322 MD |
96 | end: |
97 | ust_unlock(); | |
4e48b5d2 | 98 | return reg_provider; |
53569322 MD |
99 | } |
100 | ||
4e48b5d2 | 101 | void lttng_ust_context_provider_unregister(struct lttng_ust_registered_context_provider *reg_provider) |
53569322 | 102 | { |
c362addf MD |
103 | lttng_ust_fixup_tls(); |
104 | ||
53569322 MD |
105 | if (ust_lock()) |
106 | goto end; | |
4e48b5d2 | 107 | lttng_ust_context_set_session_provider(reg_provider->provider->name, |
ce7352a2 | 108 | lttng_ust_dummy_get_size, lttng_ust_dummy_record, |
4e48b5d2 | 109 | lttng_ust_dummy_get_value, NULL); |
d8d2416d | 110 | |
4e48b5d2 | 111 | lttng_ust_context_set_event_notifier_group_provider(reg_provider->provider->name, |
d8d2416d | 112 | lttng_ust_dummy_get_size, lttng_ust_dummy_record, |
4e48b5d2 | 113 | lttng_ust_dummy_get_value, NULL); |
d8d2416d | 114 | |
4e48b5d2 | 115 | cds_hlist_del(®_provider->node); |
53569322 MD |
116 | end: |
117 | ust_unlock(); | |
4e48b5d2 | 118 | free(reg_provider); |
53569322 MD |
119 | } |
120 | ||
121 | /* | |
122 | * Called with ust mutex held. | |
123 | * Add application context to array of context, even if the application | |
124 | * context is not currently loaded by application. It will then use the | |
125 | * dummy callbacks in that case. | |
126 | * Always performed before tracing is started, since it modifies | |
127 | * metadata describing the context. | |
128 | */ | |
129 | int lttng_ust_add_app_context_to_ctx_rcu(const char *name, | |
daacdbfc | 130 | struct lttng_ust_ctx **ctx) |
53569322 | 131 | { |
4e48b5d2 | 132 | const struct lttng_ust_context_provider *provider; |
daacdbfc | 133 | struct lttng_ust_ctx_field *new_field = NULL; |
4e48b5d2 MD |
134 | struct lttng_ust_event_field *event_field = NULL; |
135 | struct lttng_ust_type_common *type = NULL; | |
53569322 MD |
136 | int ret; |
137 | ||
138 | if (*ctx && lttng_find_context(*ctx, name)) | |
139 | return -EEXIST; | |
daacdbfc MD |
140 | new_field = zmalloc(sizeof(struct lttng_ust_ctx_field)); |
141 | if (!new_field) { | |
142 | ret = -ENOMEM; | |
143 | goto error_field_alloc; | |
144 | } | |
4e48b5d2 MD |
145 | event_field = zmalloc(sizeof(struct lttng_ust_event_field)); |
146 | if (!event_field) { | |
daacdbfc MD |
147 | ret = -ENOMEM; |
148 | goto error_event_field_alloc; | |
149 | } | |
4e48b5d2 MD |
150 | event_field->name = strdup(name); |
151 | if (!event_field->name) { | |
daacdbfc MD |
152 | ret = -ENOMEM; |
153 | goto error_field_name_alloc; | |
154 | } | |
4e48b5d2 MD |
155 | type = zmalloc(sizeof(struct lttng_ust_type_common)); |
156 | if (!type) { | |
a084756d MD |
157 | ret = -ENOMEM; |
158 | goto error_field_type_alloc; | |
159 | } | |
4e48b5d2 MD |
160 | type->type = lttng_ust_type_dynamic; |
161 | event_field->type = type; | |
162 | new_field->event_field = event_field; | |
53569322 MD |
163 | /* |
164 | * If provider is not found, we add the context anyway, but | |
165 | * it will provide a dummy context. | |
166 | */ | |
167 | provider = lookup_provider_by_name(name); | |
168 | if (provider) { | |
daacdbfc MD |
169 | new_field->get_size = provider->get_size; |
170 | new_field->record = provider->record; | |
171 | new_field->get_value = provider->get_value; | |
53569322 | 172 | } else { |
daacdbfc MD |
173 | new_field->get_size = lttng_ust_dummy_get_size; |
174 | new_field->record = lttng_ust_dummy_record; | |
175 | new_field->get_value = lttng_ust_dummy_get_value; | |
53569322 | 176 | } |
daacdbfc MD |
177 | /* |
178 | * For application context, add it by expanding | |
179 | * ctx array. Ownership of new_field is passed to the callee on | |
180 | * success. | |
181 | */ | |
4e48b5d2 | 182 | ret = lttng_ust_context_append_rcu(ctx, new_field); |
53569322 | 183 | if (ret) { |
4e48b5d2 | 184 | free(type); |
a084756d | 185 | free((char *) new_field->event_field->name); |
4e48b5d2 | 186 | free(event_field); |
daacdbfc | 187 | free(new_field); |
53569322 MD |
188 | return ret; |
189 | } | |
190 | return 0; | |
daacdbfc | 191 | |
a084756d MD |
192 | error_field_type_alloc: |
193 | free((char *) new_field->event_field->name); | |
daacdbfc | 194 | error_field_name_alloc: |
4e48b5d2 | 195 | free(event_field); |
daacdbfc MD |
196 | error_event_field_alloc: |
197 | free(new_field); | |
198 | error_field_alloc: | |
199 | return ret; | |
53569322 | 200 | } |