Commit | Line | Data |
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8020ceb5 | 1 | /* |
c0c0989a | 2 | * SPDX-License-Identifier: LGPL-2.1-only |
8020ceb5 | 3 | * |
e92f3e28 MD |
4 | * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
5 | * | |
c0c0989a | 6 | * LTTng UST trace/channel/event context management. |
8020ceb5 MD |
7 | */ |
8 | ||
3fbec7dc | 9 | #define _LGPL_SOURCE |
4318ae1b MD |
10 | #include <lttng/ust-events.h> |
11 | #include <lttng/ust-tracer.h> | |
ae4b659d | 12 | #include <ust-context-provider.h> |
10544ee8 | 13 | #include <lttng/urcu/pointer.h> |
b653ddc1 | 14 | #include <lttng/urcu/urcu-ust.h> |
a0a3bef9 | 15 | #include <usterr-signal-safe.h> |
864a1eda | 16 | #include <ust-helper.h> |
b4051ad8 | 17 | #include <stddef.h> |
8d8a24c8 | 18 | #include <string.h> |
8173ec7c | 19 | #include <assert.h> |
10544ee8 | 20 | #include "tracepoint-internal.h" |
8173ec7c | 21 | |
51f804ec FD |
22 | #include "context-internal.h" |
23 | ||
77aa5901 MD |
24 | /* |
25 | * The filter implementation requires that two consecutive "get" for the | |
26 | * same context performed by the same thread return the same result. | |
27 | */ | |
28 | ||
8173ec7c MD |
29 | int lttng_find_context(struct lttng_ctx *ctx, const char *name) |
30 | { | |
31 | unsigned int i; | |
53569322 | 32 | const char *subname; |
8173ec7c | 33 | |
53569322 MD |
34 | if (strncmp(name, "$ctx.", strlen("$ctx.")) == 0) { |
35 | subname = name + strlen("$ctx."); | |
36 | } else { | |
37 | subname = name; | |
38 | } | |
8173ec7c MD |
39 | for (i = 0; i < ctx->nr_fields; i++) { |
40 | /* Skip allocated (but non-initialized) contexts */ | |
41 | if (!ctx->fields[i].event_field.name) | |
42 | continue; | |
53569322 | 43 | if (!strcmp(ctx->fields[i].event_field.name, subname)) |
8173ec7c MD |
44 | return 1; |
45 | } | |
46 | return 0; | |
47 | } | |
8020ceb5 | 48 | |
77aa5901 MD |
49 | int lttng_get_context_index(struct lttng_ctx *ctx, const char *name) |
50 | { | |
51 | unsigned int i; | |
53569322 | 52 | const char *subname; |
77aa5901 MD |
53 | |
54 | if (!ctx) | |
55 | return -1; | |
53569322 MD |
56 | if (strncmp(name, "$ctx.", strlen("$ctx.")) == 0) { |
57 | subname = name + strlen("$ctx."); | |
58 | } else { | |
59 | subname = name; | |
60 | } | |
77aa5901 MD |
61 | for (i = 0; i < ctx->nr_fields; i++) { |
62 | /* Skip allocated (but non-initialized) contexts */ | |
63 | if (!ctx->fields[i].event_field.name) | |
64 | continue; | |
53569322 | 65 | if (!strcmp(ctx->fields[i].event_field.name, subname)) |
77aa5901 MD |
66 | return i; |
67 | } | |
68 | return -1; | |
69 | } | |
70 | ||
53569322 MD |
71 | static int lttng_find_context_provider(struct lttng_ctx *ctx, const char *name) |
72 | { | |
73 | unsigned int i; | |
74 | ||
75 | for (i = 0; i < ctx->nr_fields; i++) { | |
76 | /* Skip allocated (but non-initialized) contexts */ | |
77 | if (!ctx->fields[i].event_field.name) | |
78 | continue; | |
79 | if (!strncmp(ctx->fields[i].event_field.name, name, | |
80 | strlen(name))) | |
81 | return 1; | |
82 | } | |
83 | return 0; | |
84 | } | |
85 | ||
a0a748b8 MD |
86 | /* |
87 | * Note: as we append context information, the pointer location may change. | |
88 | */ | |
8020ceb5 MD |
89 | struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx_p) |
90 | { | |
91 | struct lttng_ctx_field *field; | |
92 | struct lttng_ctx *ctx; | |
93 | ||
94 | if (!*ctx_p) { | |
8d8a24c8 | 95 | *ctx_p = zmalloc(sizeof(struct lttng_ctx)); |
8020ceb5 MD |
96 | if (!*ctx_p) |
97 | return NULL; | |
b2cc986a | 98 | (*ctx_p)->largest_align = 1; |
8020ceb5 MD |
99 | } |
100 | ctx = *ctx_p; | |
101 | if (ctx->nr_fields + 1 > ctx->allocated_fields) { | |
102 | struct lttng_ctx_field *new_fields; | |
103 | ||
104 | ctx->allocated_fields = max_t(size_t, 1, 2 * ctx->allocated_fields); | |
8d8a24c8 | 105 | new_fields = zmalloc(ctx->allocated_fields * sizeof(struct lttng_ctx_field)); |
8020ceb5 MD |
106 | if (!new_fields) |
107 | return NULL; | |
108 | if (ctx->fields) | |
109 | memcpy(new_fields, ctx->fields, sizeof(*ctx->fields) * ctx->nr_fields); | |
8d8a24c8 | 110 | free(ctx->fields); |
8020ceb5 MD |
111 | ctx->fields = new_fields; |
112 | } | |
113 | field = &ctx->fields[ctx->nr_fields]; | |
114 | ctx->nr_fields++; | |
115 | return field; | |
116 | } | |
8020ceb5 | 117 | |
53569322 MD |
118 | int lttng_context_add_rcu(struct lttng_ctx **ctx_p, |
119 | const struct lttng_ctx_field *f) | |
120 | { | |
121 | struct lttng_ctx *old_ctx = *ctx_p, *new_ctx = NULL; | |
122 | struct lttng_ctx_field *new_fields = NULL; | |
123 | struct lttng_ctx_field *nf; | |
124 | ||
125 | if (old_ctx) { | |
126 | new_ctx = zmalloc(sizeof(struct lttng_ctx)); | |
127 | if (!new_ctx) | |
128 | return -ENOMEM; | |
129 | *new_ctx = *old_ctx; | |
130 | new_fields = zmalloc(new_ctx->allocated_fields | |
131 | * sizeof(struct lttng_ctx_field)); | |
132 | if (!new_fields) { | |
133 | free(new_ctx); | |
134 | return -ENOMEM; | |
135 | } | |
136 | memcpy(new_fields, old_ctx->fields, | |
137 | sizeof(*old_ctx->fields) * old_ctx->nr_fields); | |
138 | new_ctx->fields = new_fields; | |
139 | } | |
140 | nf = lttng_append_context(&new_ctx); | |
141 | if (!nf) { | |
142 | free(new_fields); | |
143 | free(new_ctx); | |
144 | return -ENOMEM; | |
145 | } | |
146 | *nf = *f; | |
147 | lttng_context_update(new_ctx); | |
10544ee8 | 148 | lttng_ust_rcu_assign_pointer(*ctx_p, new_ctx); |
b653ddc1 | 149 | lttng_ust_urcu_synchronize_rcu(); |
53569322 MD |
150 | if (old_ctx) { |
151 | free(old_ctx->fields); | |
152 | free(old_ctx); | |
153 | } | |
154 | return 0; | |
155 | } | |
156 | ||
b2cc986a MD |
157 | /* |
158 | * lttng_context_update() should be called at least once between context | |
159 | * modification and trace start. | |
160 | */ | |
161 | void lttng_context_update(struct lttng_ctx *ctx) | |
162 | { | |
163 | int i; | |
164 | size_t largest_align = 8; /* in bits */ | |
165 | ||
166 | for (i = 0; i < ctx->nr_fields; i++) { | |
167 | struct lttng_type *type; | |
168 | size_t field_align = 8; | |
169 | ||
170 | type = &ctx->fields[i].event_field.type; | |
171 | switch (type->atype) { | |
172 | case atype_integer: | |
218deb69 | 173 | field_align = type->u.integer.alignment; |
b2cc986a | 174 | break; |
218deb69 MD |
175 | case atype_array_nestable: |
176 | { | |
177 | const struct lttng_type *nested_type; | |
178 | ||
179 | nested_type = type->u.array_nestable.elem_type; | |
180 | switch (nested_type->atype) { | |
181 | case atype_integer: | |
182 | field_align = nested_type->u.integer.alignment; | |
183 | break; | |
184 | case atype_string: | |
185 | break; | |
186 | ||
218deb69 | 187 | case atype_array_nestable: |
218deb69 MD |
188 | case atype_sequence_nestable: |
189 | default: | |
190 | WARN_ON_ONCE(1); | |
191 | break; | |
192 | } | |
193 | field_align = max_t(size_t, field_align, | |
194 | type->u.array_nestable.alignment); | |
195 | break; | |
196 | } | |
218deb69 MD |
197 | case atype_sequence_nestable: |
198 | { | |
199 | const struct lttng_type *nested_type; | |
200 | ||
201 | nested_type = type->u.sequence_nestable.elem_type; | |
202 | switch (nested_type->atype) { | |
203 | case atype_integer: | |
204 | field_align = nested_type->u.integer.alignment; | |
205 | break; | |
206 | ||
207 | case atype_string: | |
208 | break; | |
209 | ||
218deb69 | 210 | case atype_array_nestable: |
218deb69 | 211 | case atype_sequence_nestable: |
b2cc986a MD |
212 | default: |
213 | WARN_ON_ONCE(1); | |
214 | break; | |
215 | } | |
218deb69 MD |
216 | field_align = max_t(size_t, field_align, |
217 | type->u.sequence_nestable.alignment); | |
b2cc986a MD |
218 | break; |
219 | } | |
220 | case atype_string: | |
221 | break; | |
53569322 MD |
222 | case atype_dynamic: |
223 | break; | |
218deb69 | 224 | case atype_enum_nestable: |
b2cc986a MD |
225 | default: |
226 | WARN_ON_ONCE(1); | |
227 | break; | |
228 | } | |
229 | largest_align = max_t(size_t, largest_align, field_align); | |
230 | } | |
231 | ctx->largest_align = largest_align >> 3; /* bits to bytes */ | |
232 | } | |
233 | ||
b13d13b1 MD |
234 | /* |
235 | * Remove last context field. | |
236 | */ | |
8020ceb5 MD |
237 | void lttng_remove_context_field(struct lttng_ctx **ctx_p, |
238 | struct lttng_ctx_field *field) | |
239 | { | |
240 | struct lttng_ctx *ctx; | |
241 | ||
242 | ctx = *ctx_p; | |
243 | ctx->nr_fields--; | |
8173ec7c | 244 | assert(&ctx->fields[ctx->nr_fields] == field); |
53569322 | 245 | assert(field->field_name == NULL); |
8020ceb5 MD |
246 | memset(&ctx->fields[ctx->nr_fields], 0, sizeof(struct lttng_ctx_field)); |
247 | } | |
8020ceb5 MD |
248 | |
249 | void lttng_destroy_context(struct lttng_ctx *ctx) | |
250 | { | |
251 | int i; | |
252 | ||
253 | if (!ctx) | |
254 | return; | |
255 | for (i = 0; i < ctx->nr_fields; i++) { | |
256 | if (ctx->fields[i].destroy) | |
257 | ctx->fields[i].destroy(&ctx->fields[i]); | |
53569322 | 258 | free(ctx->fields[i].field_name); |
8020ceb5 | 259 | } |
8d8a24c8 MD |
260 | free(ctx->fields); |
261 | free(ctx); | |
8020ceb5 | 262 | } |
a0a3bef9 | 263 | |
53569322 MD |
264 | /* |
265 | * Can be safely performed concurrently with tracing using the struct | |
266 | * lttng_ctx. Using RCU update. Needs to match RCU read-side handling of | |
267 | * contexts. | |
268 | * | |
269 | * This does not allow adding, removing, or changing typing of the | |
270 | * contexts, since this needs to stay invariant for metadata. However, | |
271 | * it allows updating the handlers associated with all contexts matching | |
272 | * a provider (by name) while tracing is using it, in a way that ensures | |
273 | * a single RCU read-side critical section see either all old, or all | |
274 | * new handlers. | |
275 | */ | |
276 | int lttng_ust_context_set_provider_rcu(struct lttng_ctx **_ctx, | |
277 | const char *name, | |
278 | size_t (*get_size)(struct lttng_ctx_field *field, size_t offset), | |
279 | void (*record)(struct lttng_ctx_field *field, | |
280 | struct lttng_ust_lib_ring_buffer_ctx *ctx, | |
281 | struct lttng_channel *chan), | |
282 | void (*get_value)(struct lttng_ctx_field *field, | |
283 | struct lttng_ctx_value *value)) | |
284 | { | |
285 | int i, ret; | |
286 | struct lttng_ctx *ctx = *_ctx, *new_ctx; | |
287 | struct lttng_ctx_field *new_fields; | |
288 | ||
289 | if (!ctx || !lttng_find_context_provider(ctx, name)) | |
290 | return 0; | |
291 | /* | |
292 | * We have at least one instance of context for the provider. | |
293 | */ | |
294 | new_ctx = zmalloc(sizeof(*new_ctx)); | |
295 | if (!new_ctx) | |
296 | return -ENOMEM; | |
297 | *new_ctx = *ctx; | |
298 | new_fields = zmalloc(sizeof(*new_fields) * ctx->allocated_fields); | |
299 | if (!new_fields) { | |
300 | ret = -ENOMEM; | |
301 | goto field_error; | |
302 | } | |
303 | memcpy(new_fields, ctx->fields, | |
304 | sizeof(*new_fields) * ctx->allocated_fields); | |
305 | for (i = 0; i < ctx->nr_fields; i++) { | |
306 | if (strncmp(new_fields[i].event_field.name, | |
307 | name, strlen(name)) != 0) | |
308 | continue; | |
309 | new_fields[i].get_size = get_size; | |
310 | new_fields[i].record = record; | |
311 | new_fields[i].get_value = get_value; | |
312 | } | |
313 | new_ctx->fields = new_fields; | |
10544ee8 | 314 | lttng_ust_rcu_assign_pointer(*_ctx, new_ctx); |
b653ddc1 | 315 | lttng_ust_urcu_synchronize_rcu(); |
53569322 MD |
316 | free(ctx->fields); |
317 | free(ctx); | |
318 | return 0; | |
319 | ||
320 | field_error: | |
321 | free(new_ctx); | |
322 | return ret; | |
323 | } | |
324 | ||
51f804ec | 325 | int lttng_context_init_all(struct lttng_ctx **ctx) |
a0a3bef9 MD |
326 | { |
327 | int ret; | |
328 | ||
53569322 | 329 | ret = lttng_add_pthread_id_to_ctx(ctx); |
a0a3bef9 MD |
330 | if (ret) { |
331 | WARN("Cannot add context lttng_add_pthread_id_to_ctx"); | |
53569322 | 332 | goto error; |
a0a3bef9 | 333 | } |
53569322 | 334 | ret = lttng_add_vtid_to_ctx(ctx); |
a0a3bef9 MD |
335 | if (ret) { |
336 | WARN("Cannot add context lttng_add_vtid_to_ctx"); | |
53569322 | 337 | goto error; |
a0a3bef9 | 338 | } |
53569322 | 339 | ret = lttng_add_vpid_to_ctx(ctx); |
a0a3bef9 MD |
340 | if (ret) { |
341 | WARN("Cannot add context lttng_add_vpid_to_ctx"); | |
53569322 | 342 | goto error; |
a0a3bef9 | 343 | } |
53569322 | 344 | ret = lttng_add_procname_to_ctx(ctx); |
a0a3bef9 MD |
345 | if (ret) { |
346 | WARN("Cannot add context lttng_add_procname_to_ctx"); | |
53569322 | 347 | goto error; |
a0a3bef9 | 348 | } |
53569322 | 349 | ret = lttng_add_cpu_id_to_ctx(ctx); |
c7ea8487 MD |
350 | if (ret) { |
351 | WARN("Cannot add context lttng_add_cpu_id_to_ctx"); | |
53569322 | 352 | goto error; |
c7ea8487 | 353 | } |
735bef47 MJ |
354 | ret = lttng_add_cgroup_ns_to_ctx(ctx); |
355 | if (ret) { | |
356 | WARN("Cannot add context lttng_add_cgroup_ns_to_ctx"); | |
357 | goto error; | |
358 | } | |
359 | ret = lttng_add_ipc_ns_to_ctx(ctx); | |
360 | if (ret) { | |
361 | WARN("Cannot add context lttng_add_ipc_ns_to_ctx"); | |
362 | goto error; | |
363 | } | |
364 | ret = lttng_add_mnt_ns_to_ctx(ctx); | |
365 | if (ret) { | |
366 | WARN("Cannot add context lttng_add_mnt_ns_to_ctx"); | |
367 | goto error; | |
368 | } | |
369 | ret = lttng_add_net_ns_to_ctx(ctx); | |
370 | if (ret) { | |
371 | WARN("Cannot add context lttng_add_net_ns_to_ctx"); | |
372 | goto error; | |
373 | } | |
374 | ret = lttng_add_pid_ns_to_ctx(ctx); | |
375 | if (ret) { | |
376 | WARN("Cannot add context lttng_add_pid_ns_to_ctx"); | |
377 | goto error; | |
378 | } | |
cefef7a7 MJ |
379 | ret = lttng_add_time_ns_to_ctx(ctx); |
380 | if (ret) { | |
381 | WARN("Cannot add context lttng_add_time_ns_to_ctx"); | |
382 | goto error; | |
383 | } | |
735bef47 MJ |
384 | ret = lttng_add_user_ns_to_ctx(ctx); |
385 | if (ret) { | |
386 | WARN("Cannot add context lttng_add_user_ns_to_ctx"); | |
387 | goto error; | |
388 | } | |
389 | ret = lttng_add_uts_ns_to_ctx(ctx); | |
390 | if (ret) { | |
391 | WARN("Cannot add context lttng_add_uts_ns_to_ctx"); | |
392 | goto error; | |
393 | } | |
fca2f191 MJ |
394 | ret = lttng_add_vuid_to_ctx(ctx); |
395 | if (ret) { | |
396 | WARN("Cannot add context lttng_add_vuid_to_ctx"); | |
397 | goto error; | |
398 | } | |
399 | ret = lttng_add_veuid_to_ctx(ctx); | |
400 | if (ret) { | |
401 | WARN("Cannot add context lttng_add_veuid_to_ctx"); | |
402 | goto error; | |
403 | } | |
404 | ret = lttng_add_vsuid_to_ctx(ctx); | |
405 | if (ret) { | |
406 | WARN("Cannot add context lttng_add_vsuid_to_ctx"); | |
407 | goto error; | |
408 | } | |
409 | ret = lttng_add_vgid_to_ctx(ctx); | |
410 | if (ret) { | |
411 | WARN("Cannot add context lttng_add_vgid_to_ctx"); | |
412 | goto error; | |
413 | } | |
414 | ret = lttng_add_vegid_to_ctx(ctx); | |
415 | if (ret) { | |
416 | WARN("Cannot add context lttng_add_vegid_to_ctx"); | |
417 | goto error; | |
418 | } | |
419 | ret = lttng_add_vsgid_to_ctx(ctx); | |
420 | if (ret) { | |
421 | WARN("Cannot add context lttng_add_vsgid_to_ctx"); | |
422 | goto error; | |
423 | } | |
53569322 MD |
424 | lttng_context_update(*ctx); |
425 | return 0; | |
a0a3bef9 | 426 | |
53569322 MD |
427 | error: |
428 | lttng_destroy_context(*ctx); | |
429 | return ret; | |
a0a3bef9 | 430 | } |