| 1 | /* |
| 2 | * Copyright (C) 2019 Jonathan Rajotte <jonathan.rajotte-julien@efficios.com> |
| 3 | * |
| 4 | * SPDX-License-Identifier: LGPL-2.1-only |
| 5 | * |
| 6 | */ |
| 7 | |
| 8 | #include <common/credentials.hpp> |
| 9 | #include <common/error.hpp> |
| 10 | #include <common/hashtable/hashtable.hpp> |
| 11 | #include <common/hashtable/utils.hpp> |
| 12 | #include <common/macros.hpp> |
| 13 | #include <common/mi-lttng.hpp> |
| 14 | #include <common/payload-view.hpp> |
| 15 | #include <common/payload.hpp> |
| 16 | #include <common/runas.hpp> |
| 17 | #include <lttng/event-rule/event-rule-internal.hpp> |
| 18 | #include <lttng/event-rule/kernel-uprobe-internal.hpp> |
| 19 | #include <lttng/userspace-probe-internal.hpp> |
| 20 | |
| 21 | #define IS_UPROBE_EVENT_RULE(rule) \ |
| 22 | (lttng_event_rule_get_type(rule) == LTTNG_EVENT_RULE_TYPE_KERNEL_UPROBE) |
| 23 | |
| 24 | static void lttng_event_rule_kernel_uprobe_destroy(struct lttng_event_rule *rule) |
| 25 | { |
| 26 | struct lttng_event_rule_kernel_uprobe *uprobe; |
| 27 | |
| 28 | uprobe = container_of(rule, struct lttng_event_rule_kernel_uprobe, parent); |
| 29 | |
| 30 | lttng_userspace_probe_location_destroy(uprobe->location); |
| 31 | free(uprobe->name); |
| 32 | free(uprobe); |
| 33 | } |
| 34 | |
| 35 | static bool lttng_event_rule_kernel_uprobe_validate( |
| 36 | const struct lttng_event_rule *rule) |
| 37 | { |
| 38 | bool valid = false; |
| 39 | struct lttng_event_rule_kernel_uprobe *uprobe; |
| 40 | |
| 41 | if (!rule) { |
| 42 | goto end; |
| 43 | } |
| 44 | |
| 45 | uprobe = container_of(rule, struct lttng_event_rule_kernel_uprobe, parent); |
| 46 | |
| 47 | /* Required field. */ |
| 48 | if (!uprobe->name) { |
| 49 | ERR("Invalid uprobe event rule: a pattern must be set."); |
| 50 | goto end; |
| 51 | } |
| 52 | |
| 53 | if (!uprobe->location) { |
| 54 | ERR("Invalid uprobe event rule: a location must be set."); |
| 55 | goto end; |
| 56 | } |
| 57 | |
| 58 | valid = true; |
| 59 | end: |
| 60 | return valid; |
| 61 | } |
| 62 | |
| 63 | static int lttng_event_rule_kernel_uprobe_serialize( |
| 64 | const struct lttng_event_rule *rule, |
| 65 | struct lttng_payload *payload) |
| 66 | { |
| 67 | int ret; |
| 68 | size_t name_len, header_offset, size_before_probe; |
| 69 | struct lttng_event_rule_kernel_uprobe *uprobe; |
| 70 | struct lttng_event_rule_kernel_uprobe_comm uprobe_comm = {}; |
| 71 | struct lttng_event_rule_kernel_uprobe_comm *header; |
| 72 | |
| 73 | if (!rule || !IS_UPROBE_EVENT_RULE(rule)) { |
| 74 | ret = -1; |
| 75 | goto end; |
| 76 | } |
| 77 | |
| 78 | header_offset = payload->buffer.size; |
| 79 | |
| 80 | DBG("Serializing uprobe event rule."); |
| 81 | uprobe = container_of(rule, struct lttng_event_rule_kernel_uprobe, parent); |
| 82 | |
| 83 | name_len = strlen(uprobe->name) + 1; |
| 84 | |
| 85 | uprobe_comm.name_len = name_len; |
| 86 | |
| 87 | ret = lttng_dynamic_buffer_append( |
| 88 | &payload->buffer, &uprobe_comm, sizeof(uprobe_comm)); |
| 89 | if (ret) { |
| 90 | goto end; |
| 91 | } |
| 92 | ret = lttng_dynamic_buffer_append( |
| 93 | &payload->buffer, uprobe->name, name_len); |
| 94 | if (ret) { |
| 95 | goto end; |
| 96 | } |
| 97 | |
| 98 | size_before_probe = payload->buffer.size; |
| 99 | |
| 100 | /* This serialize return the size taken in the buffer. */ |
| 101 | ret = lttng_userspace_probe_location_serialize( |
| 102 | uprobe->location, payload); |
| 103 | if (ret < 0) { |
| 104 | goto end; |
| 105 | } |
| 106 | |
| 107 | /* Update the header regarding the probe size. */ |
| 108 | header = (struct lttng_event_rule_kernel_uprobe_comm |
| 109 | *) ((char *) payload->buffer.data + |
| 110 | header_offset); |
| 111 | header->location_len = payload->buffer.size - size_before_probe; |
| 112 | |
| 113 | ret = 0; |
| 114 | |
| 115 | end: |
| 116 | return ret; |
| 117 | } |
| 118 | |
| 119 | static bool lttng_event_rule_kernel_uprobe_is_equal(const struct lttng_event_rule *_a, |
| 120 | const struct lttng_event_rule *_b) |
| 121 | { |
| 122 | bool is_equal = false; |
| 123 | struct lttng_event_rule_kernel_uprobe *a, *b; |
| 124 | |
| 125 | a = container_of(_a, struct lttng_event_rule_kernel_uprobe, parent); |
| 126 | b = container_of(_b, struct lttng_event_rule_kernel_uprobe, parent); |
| 127 | |
| 128 | /* uprobe is invalid if this is not true. */ |
| 129 | LTTNG_ASSERT(a->name); |
| 130 | LTTNG_ASSERT(b->name); |
| 131 | if (strcmp(a->name, b->name)) { |
| 132 | goto end; |
| 133 | } |
| 134 | |
| 135 | LTTNG_ASSERT(a->location); |
| 136 | LTTNG_ASSERT(b->location); |
| 137 | is_equal = lttng_userspace_probe_location_is_equal( |
| 138 | a->location, b->location); |
| 139 | end: |
| 140 | return is_equal; |
| 141 | } |
| 142 | |
| 143 | static enum lttng_error_code lttng_event_rule_kernel_uprobe_generate_filter_bytecode( |
| 144 | struct lttng_event_rule *rule __attribute__((unused)), |
| 145 | const struct lttng_credentials *creds __attribute__((unused))) |
| 146 | { |
| 147 | /* Nothing to do. */ |
| 148 | return LTTNG_OK; |
| 149 | } |
| 150 | |
| 151 | static const char *lttng_event_rule_kernel_uprobe_get_filter( |
| 152 | const struct lttng_event_rule *rule __attribute__((unused))) |
| 153 | { |
| 154 | /* Unsupported. */ |
| 155 | return NULL; |
| 156 | } |
| 157 | |
| 158 | static const struct lttng_bytecode * |
| 159 | lttng_event_rule_kernel_uprobe_get_filter_bytecode( |
| 160 | const struct lttng_event_rule *rule __attribute__((unused))) |
| 161 | { |
| 162 | /* Unsupported. */ |
| 163 | return NULL; |
| 164 | } |
| 165 | |
| 166 | static enum lttng_event_rule_generate_exclusions_status |
| 167 | lttng_event_rule_kernel_uprobe_generate_exclusions( |
| 168 | const struct lttng_event_rule *rule __attribute__((unused)), |
| 169 | struct lttng_event_exclusion **exclusions) |
| 170 | { |
| 171 | /* Unsupported. */ |
| 172 | *exclusions = NULL; |
| 173 | return LTTNG_EVENT_RULE_GENERATE_EXCLUSIONS_STATUS_NONE; |
| 174 | } |
| 175 | |
| 176 | static unsigned long |
| 177 | lttng_event_rule_kernel_uprobe_hash( |
| 178 | const struct lttng_event_rule *rule) |
| 179 | { |
| 180 | unsigned long hash; |
| 181 | struct lttng_event_rule_kernel_uprobe *urule = |
| 182 | container_of(rule, typeof(*urule), parent); |
| 183 | |
| 184 | hash = hash_key_ulong((void *) LTTNG_EVENT_RULE_TYPE_KERNEL_UPROBE, |
| 185 | lttng_ht_seed); |
| 186 | hash ^= hash_key_str(urule->name, lttng_ht_seed); |
| 187 | hash ^= lttng_userspace_probe_location_hash(urule->location); |
| 188 | |
| 189 | return hash; |
| 190 | } |
| 191 | |
| 192 | static |
| 193 | int userspace_probe_set_location( |
| 194 | struct lttng_event_rule_kernel_uprobe *uprobe, |
| 195 | const struct lttng_userspace_probe_location *location) |
| 196 | { |
| 197 | int ret; |
| 198 | struct lttng_userspace_probe_location *location_copy = NULL; |
| 199 | |
| 200 | if (!uprobe || !location || uprobe->location) { |
| 201 | ret = -1; |
| 202 | goto end; |
| 203 | } |
| 204 | |
| 205 | location_copy = lttng_userspace_probe_location_copy(location); |
| 206 | if (!location_copy) { |
| 207 | ret = -1; |
| 208 | goto end; |
| 209 | } |
| 210 | |
| 211 | uprobe->location = location_copy; |
| 212 | location_copy = NULL; |
| 213 | ret = 0; |
| 214 | end: |
| 215 | lttng_userspace_probe_location_destroy(location_copy); |
| 216 | return ret; |
| 217 | } |
| 218 | |
| 219 | static enum lttng_error_code lttng_event_rule_kernel_uprobe_mi_serialize( |
| 220 | const struct lttng_event_rule *rule, struct mi_writer *writer) |
| 221 | { |
| 222 | int ret; |
| 223 | enum lttng_error_code ret_code; |
| 224 | enum lttng_event_rule_status status; |
| 225 | const char *event_name = NULL; |
| 226 | const struct lttng_userspace_probe_location *location = NULL; |
| 227 | |
| 228 | LTTNG_ASSERT(rule); |
| 229 | LTTNG_ASSERT(writer); |
| 230 | LTTNG_ASSERT(IS_UPROBE_EVENT_RULE(rule)); |
| 231 | |
| 232 | status = lttng_event_rule_kernel_uprobe_get_event_name( |
| 233 | rule, &event_name); |
| 234 | LTTNG_ASSERT(status == LTTNG_EVENT_RULE_STATUS_OK); |
| 235 | LTTNG_ASSERT(event_name); |
| 236 | |
| 237 | status = lttng_event_rule_kernel_uprobe_get_location(rule, &location); |
| 238 | LTTNG_ASSERT(status == LTTNG_EVENT_RULE_STATUS_OK); |
| 239 | LTTNG_ASSERT(location); |
| 240 | |
| 241 | /* Open event rule kernel uprobe element. */ |
| 242 | ret = mi_lttng_writer_open_element( |
| 243 | writer, mi_lttng_element_event_rule_kernel_uprobe); |
| 244 | if (ret) { |
| 245 | goto mi_error; |
| 246 | } |
| 247 | |
| 248 | /* Event name. */ |
| 249 | ret = mi_lttng_writer_write_element_string(writer, |
| 250 | mi_lttng_element_event_rule_event_name, event_name); |
| 251 | if (ret) { |
| 252 | goto mi_error; |
| 253 | } |
| 254 | |
| 255 | /* Probe location. */ |
| 256 | ret_code = lttng_userspace_probe_location_mi_serialize(location, writer); |
| 257 | if (ret_code != LTTNG_OK) { |
| 258 | goto end; |
| 259 | } |
| 260 | |
| 261 | /* Close event rule kernel uprobe element. */ |
| 262 | ret = mi_lttng_writer_close_element(writer); |
| 263 | if (ret) { |
| 264 | goto mi_error; |
| 265 | } |
| 266 | |
| 267 | ret_code = LTTNG_OK; |
| 268 | goto end; |
| 269 | |
| 270 | mi_error: |
| 271 | ret_code = LTTNG_ERR_MI_IO_FAIL; |
| 272 | end: |
| 273 | return ret_code; |
| 274 | } |
| 275 | |
| 276 | struct lttng_event_rule *lttng_event_rule_kernel_uprobe_create( |
| 277 | const struct lttng_userspace_probe_location *location) |
| 278 | { |
| 279 | struct lttng_event_rule *rule = NULL; |
| 280 | struct lttng_event_rule_kernel_uprobe *urule; |
| 281 | |
| 282 | urule = zmalloc<lttng_event_rule_kernel_uprobe>(); |
| 283 | if (!urule) { |
| 284 | goto end; |
| 285 | } |
| 286 | |
| 287 | rule = &urule->parent; |
| 288 | lttng_event_rule_init(&urule->parent, LTTNG_EVENT_RULE_TYPE_KERNEL_UPROBE); |
| 289 | urule->parent.validate = lttng_event_rule_kernel_uprobe_validate; |
| 290 | urule->parent.serialize = lttng_event_rule_kernel_uprobe_serialize; |
| 291 | urule->parent.equal = lttng_event_rule_kernel_uprobe_is_equal; |
| 292 | urule->parent.destroy = lttng_event_rule_kernel_uprobe_destroy; |
| 293 | urule->parent.generate_filter_bytecode = |
| 294 | lttng_event_rule_kernel_uprobe_generate_filter_bytecode; |
| 295 | urule->parent.get_filter = lttng_event_rule_kernel_uprobe_get_filter; |
| 296 | urule->parent.get_filter_bytecode = |
| 297 | lttng_event_rule_kernel_uprobe_get_filter_bytecode; |
| 298 | urule->parent.generate_exclusions = |
| 299 | lttng_event_rule_kernel_uprobe_generate_exclusions; |
| 300 | urule->parent.hash = lttng_event_rule_kernel_uprobe_hash; |
| 301 | urule->parent.mi_serialize = lttng_event_rule_kernel_uprobe_mi_serialize; |
| 302 | |
| 303 | if (userspace_probe_set_location(urule, location)) { |
| 304 | lttng_event_rule_destroy(rule); |
| 305 | rule = NULL; |
| 306 | } |
| 307 | |
| 308 | end: |
| 309 | return rule; |
| 310 | } |
| 311 | |
| 312 | ssize_t lttng_event_rule_kernel_uprobe_create_from_payload( |
| 313 | struct lttng_payload_view *view, |
| 314 | struct lttng_event_rule **_event_rule) |
| 315 | { |
| 316 | ssize_t ret, offset = 0; |
| 317 | const struct lttng_event_rule_kernel_uprobe_comm *uprobe_comm; |
| 318 | const char *name; |
| 319 | struct lttng_buffer_view current_buffer_view; |
| 320 | struct lttng_event_rule *rule = NULL; |
| 321 | struct lttng_userspace_probe_location *location = NULL; |
| 322 | enum lttng_event_rule_status status; |
| 323 | |
| 324 | if (!_event_rule) { |
| 325 | ret = -1; |
| 326 | goto end; |
| 327 | } |
| 328 | |
| 329 | current_buffer_view = lttng_buffer_view_from_view( |
| 330 | &view->buffer, offset, sizeof(*uprobe_comm)); |
| 331 | if (!lttng_buffer_view_is_valid(¤t_buffer_view)) { |
| 332 | ERR("Failed to initialize from malformed event rule uprobe: buffer too short to contain header"); |
| 333 | ret = -1; |
| 334 | goto end; |
| 335 | } |
| 336 | |
| 337 | uprobe_comm = (typeof(uprobe_comm)) current_buffer_view.data; |
| 338 | |
| 339 | /* Skip to payload. */ |
| 340 | offset += current_buffer_view.size; |
| 341 | |
| 342 | /* Map the name. */ |
| 343 | current_buffer_view = lttng_buffer_view_from_view( |
| 344 | &view->buffer, offset, uprobe_comm->name_len); |
| 345 | if (!lttng_buffer_view_is_valid(¤t_buffer_view)) { |
| 346 | ret = -1; |
| 347 | goto end; |
| 348 | } |
| 349 | |
| 350 | name = current_buffer_view.data; |
| 351 | if (!lttng_buffer_view_contains_string(¤t_buffer_view, name, |
| 352 | uprobe_comm->name_len)) { |
| 353 | ret = -1; |
| 354 | goto end; |
| 355 | } |
| 356 | |
| 357 | /* Skip after the name. */ |
| 358 | offset += uprobe_comm->name_len; |
| 359 | |
| 360 | /* Map the location. */ |
| 361 | { |
| 362 | struct lttng_payload_view current_payload_view = |
| 363 | lttng_payload_view_from_view(view, offset, |
| 364 | uprobe_comm->location_len); |
| 365 | |
| 366 | if (!lttng_payload_view_is_valid(¤t_payload_view)) { |
| 367 | ERR("Failed to initialize from malformed event rule uprobe: buffer too short to contain location"); |
| 368 | ret = -1; |
| 369 | goto end; |
| 370 | } |
| 371 | |
| 372 | ret = lttng_userspace_probe_location_create_from_payload( |
| 373 | ¤t_payload_view, &location); |
| 374 | if (ret < 0) { |
| 375 | ret = -1; |
| 376 | goto end; |
| 377 | } |
| 378 | } |
| 379 | |
| 380 | LTTNG_ASSERT(ret == uprobe_comm->location_len); |
| 381 | |
| 382 | /* Skip after the location. */ |
| 383 | offset += uprobe_comm->location_len; |
| 384 | |
| 385 | rule = lttng_event_rule_kernel_uprobe_create(location); |
| 386 | if (!rule) { |
| 387 | ERR("Failed to create event rule uprobe."); |
| 388 | ret = -1; |
| 389 | goto end; |
| 390 | } |
| 391 | |
| 392 | status = lttng_event_rule_kernel_uprobe_set_event_name(rule, name); |
| 393 | if (status != LTTNG_EVENT_RULE_STATUS_OK) { |
| 394 | ret = -1; |
| 395 | goto end; |
| 396 | } |
| 397 | |
| 398 | if (!lttng_event_rule_kernel_uprobe_validate(rule)) { |
| 399 | ret = -1; |
| 400 | goto end; |
| 401 | } |
| 402 | |
| 403 | *_event_rule = rule; |
| 404 | rule = NULL; |
| 405 | ret = offset; |
| 406 | end: |
| 407 | lttng_userspace_probe_location_destroy(location); |
| 408 | lttng_event_rule_destroy(rule); |
| 409 | return ret; |
| 410 | } |
| 411 | |
| 412 | |
| 413 | enum lttng_event_rule_status lttng_event_rule_kernel_uprobe_get_location( |
| 414 | const struct lttng_event_rule *rule, |
| 415 | const struct lttng_userspace_probe_location **location) |
| 416 | { |
| 417 | enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK; |
| 418 | |
| 419 | if (!rule || !IS_UPROBE_EVENT_RULE(rule) || !location) { |
| 420 | status = LTTNG_EVENT_RULE_STATUS_INVALID; |
| 421 | goto end; |
| 422 | } |
| 423 | |
| 424 | *location = lttng_event_rule_kernel_uprobe_get_location_mutable(rule); |
| 425 | if (!*location) { |
| 426 | status = LTTNG_EVENT_RULE_STATUS_UNSET; |
| 427 | goto end; |
| 428 | } |
| 429 | |
| 430 | end: |
| 431 | return status; |
| 432 | } |
| 433 | |
| 434 | struct lttng_userspace_probe_location * |
| 435 | lttng_event_rule_kernel_uprobe_get_location_mutable( |
| 436 | const struct lttng_event_rule *rule) |
| 437 | { |
| 438 | struct lttng_event_rule_kernel_uprobe *uprobe; |
| 439 | |
| 440 | LTTNG_ASSERT(rule); |
| 441 | uprobe = container_of(rule, struct lttng_event_rule_kernel_uprobe, parent); |
| 442 | |
| 443 | return uprobe->location; |
| 444 | } |
| 445 | |
| 446 | enum lttng_event_rule_status lttng_event_rule_kernel_uprobe_set_event_name( |
| 447 | struct lttng_event_rule *rule, const char *name) |
| 448 | { |
| 449 | char *name_copy = NULL; |
| 450 | struct lttng_event_rule_kernel_uprobe *uprobe; |
| 451 | enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK; |
| 452 | |
| 453 | if (!rule || !IS_UPROBE_EVENT_RULE(rule) || !name || |
| 454 | strlen(name) == 0) { |
| 455 | status = LTTNG_EVENT_RULE_STATUS_INVALID; |
| 456 | goto end; |
| 457 | } |
| 458 | |
| 459 | uprobe = container_of(rule, struct lttng_event_rule_kernel_uprobe, parent); |
| 460 | name_copy = strdup(name); |
| 461 | if (!name_copy) { |
| 462 | status = LTTNG_EVENT_RULE_STATUS_ERROR; |
| 463 | goto end; |
| 464 | } |
| 465 | |
| 466 | if (uprobe->name) { |
| 467 | free(uprobe->name); |
| 468 | } |
| 469 | |
| 470 | uprobe->name = name_copy; |
| 471 | name_copy = NULL; |
| 472 | end: |
| 473 | return status; |
| 474 | } |
| 475 | |
| 476 | enum lttng_event_rule_status lttng_event_rule_kernel_uprobe_get_event_name( |
| 477 | const struct lttng_event_rule *rule, const char **name) |
| 478 | { |
| 479 | struct lttng_event_rule_kernel_uprobe *uprobe; |
| 480 | enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK; |
| 481 | |
| 482 | if (!rule || !IS_UPROBE_EVENT_RULE(rule) || !name) { |
| 483 | status = LTTNG_EVENT_RULE_STATUS_INVALID; |
| 484 | goto end; |
| 485 | } |
| 486 | |
| 487 | uprobe = container_of(rule, struct lttng_event_rule_kernel_uprobe, parent); |
| 488 | if (!uprobe->name) { |
| 489 | status = LTTNG_EVENT_RULE_STATUS_UNSET; |
| 490 | goto end; |
| 491 | } |
| 492 | |
| 493 | *name = uprobe->name; |
| 494 | end: |
| 495 | return status; |
| 496 | } |