| 1 | /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only) |
| 2 | * |
| 3 | * lttng-syscalls.c |
| 4 | * |
| 5 | * LTTng syscall probes. |
| 6 | * |
| 7 | * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 8 | */ |
| 9 | |
| 10 | #include <linux/module.h> |
| 11 | #include <linux/slab.h> |
| 12 | #include <linux/compat.h> |
| 13 | #include <linux/err.h> |
| 14 | #include <linux/bitmap.h> |
| 15 | #include <linux/in.h> |
| 16 | #include <linux/in6.h> |
| 17 | #include <linux/seq_file.h> |
| 18 | #include <linux/stringify.h> |
| 19 | #include <linux/file.h> |
| 20 | #include <linux/anon_inodes.h> |
| 21 | #include <linux/fcntl.h> |
| 22 | #include <linux/mman.h> |
| 23 | #include <asm/ptrace.h> |
| 24 | #include <asm/syscall.h> |
| 25 | |
| 26 | #include <lttng/bitfield.h> |
| 27 | #include <wrapper/tracepoint.h> |
| 28 | #include <wrapper/file.h> |
| 29 | #include <wrapper/rcu.h> |
| 30 | #include <wrapper/syscall.h> |
| 31 | #include <lttng/events.h> |
| 32 | #include <lttng/events-internal.h> |
| 33 | #include <lttng/utils.h> |
| 34 | |
| 35 | #include "lttng-syscalls.h" |
| 36 | |
| 37 | #ifndef CONFIG_COMPAT |
| 38 | # ifndef is_compat_task |
| 39 | # define is_compat_task() (0) |
| 40 | # endif |
| 41 | #endif |
| 42 | |
| 43 | /* in_compat_syscall appears in kernel 4.6. */ |
| 44 | #ifndef in_compat_syscall |
| 45 | #define in_compat_syscall() is_compat_task() |
| 46 | #endif |
| 47 | |
| 48 | enum sc_type { |
| 49 | SC_TYPE_ENTRY, |
| 50 | SC_TYPE_EXIT, |
| 51 | SC_TYPE_COMPAT_ENTRY, |
| 52 | SC_TYPE_COMPAT_EXIT, |
| 53 | }; |
| 54 | |
| 55 | #define SYSCALL_ENTRY_TOK syscall_entry_ |
| 56 | #define COMPAT_SYSCALL_ENTRY_TOK compat_syscall_entry_ |
| 57 | #define SYSCALL_EXIT_TOK syscall_exit_ |
| 58 | #define COMPAT_SYSCALL_EXIT_TOK compat_syscall_exit_ |
| 59 | |
| 60 | #define SYSCALL_ENTRY_STR __stringify(SYSCALL_ENTRY_TOK) |
| 61 | #define COMPAT_SYSCALL_ENTRY_STR __stringify(COMPAT_SYSCALL_ENTRY_TOK) |
| 62 | #define SYSCALL_EXIT_STR __stringify(SYSCALL_EXIT_TOK) |
| 63 | #define COMPAT_SYSCALL_EXIT_STR __stringify(COMPAT_SYSCALL_EXIT_TOK) |
| 64 | |
| 65 | void syscall_entry_event_probe(void *__data, struct pt_regs *regs, long id); |
| 66 | void syscall_exit_event_probe(void *__data, struct pt_regs *regs, long ret); |
| 67 | |
| 68 | /* |
| 69 | * Forward declarations for old kernels. |
| 70 | */ |
| 71 | struct mmsghdr; |
| 72 | struct rlimit64; |
| 73 | struct oldold_utsname; |
| 74 | struct old_utsname; |
| 75 | struct sel_arg_struct; |
| 76 | struct mmap_arg_struct; |
| 77 | struct file_handle; |
| 78 | struct user_msghdr; |
| 79 | |
| 80 | /* |
| 81 | * Forward declaration for kernels >= 5.6 |
| 82 | */ |
| 83 | struct timex; |
| 84 | struct timeval; |
| 85 | struct itimerval; |
| 86 | struct itimerspec; |
| 87 | |
| 88 | #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,6,0)) |
| 89 | typedef __kernel_old_time_t time_t; |
| 90 | #endif |
| 91 | |
| 92 | #ifdef IA32_NR_syscalls |
| 93 | #define NR_compat_syscalls IA32_NR_syscalls |
| 94 | #else |
| 95 | #define NR_compat_syscalls NR_syscalls |
| 96 | #endif |
| 97 | |
| 98 | /* |
| 99 | * Create LTTng tracepoint probes. |
| 100 | */ |
| 101 | #define LTTNG_PACKAGE_BUILD |
| 102 | #define CREATE_TRACE_POINTS |
| 103 | #define TP_MODULE_NOINIT |
| 104 | #define TRACE_INCLUDE_PATH instrumentation/syscalls/headers |
| 105 | |
| 106 | #define PARAMS(args...) args |
| 107 | |
| 108 | /* Handle unknown syscalls */ |
| 109 | #undef TRACE_SYSTEM |
| 110 | #define TRACE_SYSTEM syscalls_unknown |
| 111 | #include <instrumentation/syscalls/headers/syscalls_unknown.h> |
| 112 | #undef TRACE_SYSTEM |
| 113 | |
| 114 | #undef TP_PROBE_CB |
| 115 | |
| 116 | extern const struct trace_syscall_table sc_table; |
| 117 | extern const struct trace_syscall_table compat_sc_table; |
| 118 | |
| 119 | /* Event syscall exit table */ |
| 120 | extern const struct trace_syscall_table sc_exit_table; |
| 121 | extern const struct trace_syscall_table compat_sc_exit_table; |
| 122 | |
| 123 | |
| 124 | #undef SC_EXIT |
| 125 | |
| 126 | #undef CREATE_SYSCALL_TABLE |
| 127 | |
| 128 | struct lttng_syscall_filter { |
| 129 | DECLARE_BITMAP(sc_entry, NR_syscalls); |
| 130 | DECLARE_BITMAP(sc_exit, NR_syscalls); |
| 131 | DECLARE_BITMAP(sc_compat_entry, NR_compat_syscalls); |
| 132 | DECLARE_BITMAP(sc_compat_exit, NR_compat_syscalls); |
| 133 | }; |
| 134 | |
| 135 | static void syscall_entry_event_unknown(struct hlist_head *unknown_action_list_head, |
| 136 | struct pt_regs *regs, long id) |
| 137 | { |
| 138 | unsigned long args[LTTNG_SYSCALL_NR_ARGS]; |
| 139 | struct lttng_kernel_event_common_private *event_priv; |
| 140 | |
| 141 | lttng_syscall_get_arguments(current, regs, args); |
| 142 | lttng_hlist_for_each_entry_rcu(event_priv, unknown_action_list_head, u.syscall.node) { |
| 143 | if (unlikely(in_compat_syscall())) |
| 144 | __event_probe__compat_syscall_entry_unknown(event_priv->pub, id, args); |
| 145 | else |
| 146 | __event_probe__syscall_entry_unknown(event_priv->pub, id, args); |
| 147 | } |
| 148 | } |
| 149 | |
| 150 | static __always_inline |
| 151 | void syscall_entry_event_call_func(struct hlist_head *action_list, |
| 152 | void *func, unsigned int nrargs, |
| 153 | struct pt_regs *regs) |
| 154 | { |
| 155 | struct lttng_kernel_event_common_private *event_priv; |
| 156 | |
| 157 | switch (nrargs) { |
| 158 | case 0: |
| 159 | { |
| 160 | void (*fptr)(void *__data) = func; |
| 161 | |
| 162 | lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node) |
| 163 | fptr(event_priv->pub); |
| 164 | break; |
| 165 | } |
| 166 | case 1: |
| 167 | { |
| 168 | void (*fptr)(void *__data, unsigned long arg0) = func; |
| 169 | unsigned long args[LTTNG_SYSCALL_NR_ARGS]; |
| 170 | |
| 171 | lttng_syscall_get_arguments(current, regs, args); |
| 172 | lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node) |
| 173 | fptr(event_priv->pub, args[0]); |
| 174 | break; |
| 175 | } |
| 176 | case 2: |
| 177 | { |
| 178 | void (*fptr)(void *__data, |
| 179 | unsigned long arg0, |
| 180 | unsigned long arg1) = func; |
| 181 | unsigned long args[LTTNG_SYSCALL_NR_ARGS]; |
| 182 | |
| 183 | lttng_syscall_get_arguments(current, regs, args); |
| 184 | lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node) |
| 185 | fptr(event_priv->pub, args[0], args[1]); |
| 186 | break; |
| 187 | } |
| 188 | case 3: |
| 189 | { |
| 190 | void (*fptr)(void *__data, |
| 191 | unsigned long arg0, |
| 192 | unsigned long arg1, |
| 193 | unsigned long arg2) = func; |
| 194 | unsigned long args[LTTNG_SYSCALL_NR_ARGS]; |
| 195 | |
| 196 | lttng_syscall_get_arguments(current, regs, args); |
| 197 | lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node) |
| 198 | fptr(event_priv->pub, args[0], args[1], args[2]); |
| 199 | break; |
| 200 | } |
| 201 | case 4: |
| 202 | { |
| 203 | void (*fptr)(void *__data, |
| 204 | unsigned long arg0, |
| 205 | unsigned long arg1, |
| 206 | unsigned long arg2, |
| 207 | unsigned long arg3) = func; |
| 208 | unsigned long args[LTTNG_SYSCALL_NR_ARGS]; |
| 209 | |
| 210 | lttng_syscall_get_arguments(current, regs, args); |
| 211 | lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node) |
| 212 | fptr(event_priv->pub, args[0], args[1], args[2], args[3]); |
| 213 | break; |
| 214 | } |
| 215 | case 5: |
| 216 | { |
| 217 | void (*fptr)(void *__data, |
| 218 | unsigned long arg0, |
| 219 | unsigned long arg1, |
| 220 | unsigned long arg2, |
| 221 | unsigned long arg3, |
| 222 | unsigned long arg4) = func; |
| 223 | unsigned long args[LTTNG_SYSCALL_NR_ARGS]; |
| 224 | |
| 225 | lttng_syscall_get_arguments(current, regs, args); |
| 226 | lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node) |
| 227 | fptr(event_priv->pub, args[0], args[1], args[2], args[3], args[4]); |
| 228 | break; |
| 229 | } |
| 230 | case 6: |
| 231 | { |
| 232 | void (*fptr)(void *__data, |
| 233 | unsigned long arg0, |
| 234 | unsigned long arg1, |
| 235 | unsigned long arg2, |
| 236 | unsigned long arg3, |
| 237 | unsigned long arg4, |
| 238 | unsigned long arg5) = func; |
| 239 | unsigned long args[LTTNG_SYSCALL_NR_ARGS]; |
| 240 | |
| 241 | lttng_syscall_get_arguments(current, regs, args); |
| 242 | lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node) |
| 243 | fptr(event_priv->pub, args[0], args[1], args[2], |
| 244 | args[3], args[4], args[5]); |
| 245 | break; |
| 246 | } |
| 247 | default: |
| 248 | break; |
| 249 | } |
| 250 | } |
| 251 | |
| 252 | void syscall_entry_event_probe(void *__data, struct pt_regs *regs, long id) |
| 253 | { |
| 254 | struct lttng_kernel_syscall_table *syscall_table = __data; |
| 255 | struct hlist_head *action_list, *unknown_action_list; |
| 256 | const struct trace_syscall_entry *table, *entry; |
| 257 | size_t table_len; |
| 258 | |
| 259 | if (unlikely(in_compat_syscall())) { |
| 260 | struct lttng_syscall_filter *filter = syscall_table->sc_filter; |
| 261 | |
| 262 | if (id < 0 || id >= NR_compat_syscalls |
| 263 | || (!READ_ONCE(syscall_table->syscall_all_entry) && !test_bit(id, filter->sc_compat_entry))) { |
| 264 | /* System call filtered out. */ |
| 265 | return; |
| 266 | } |
| 267 | table = compat_sc_table.table; |
| 268 | table_len = compat_sc_table.len; |
| 269 | unknown_action_list = &syscall_table->compat_unknown_syscall_dispatch; |
| 270 | } else { |
| 271 | struct lttng_syscall_filter *filter = syscall_table->sc_filter; |
| 272 | |
| 273 | if (id < 0 || id >= NR_syscalls |
| 274 | || (!READ_ONCE(syscall_table->syscall_all_entry) && !test_bit(id, filter->sc_entry))) { |
| 275 | /* System call filtered out. */ |
| 276 | return; |
| 277 | } |
| 278 | table = sc_table.table; |
| 279 | table_len = sc_table.len; |
| 280 | unknown_action_list = &syscall_table->unknown_syscall_dispatch; |
| 281 | } |
| 282 | if (unlikely(id < 0 || id >= table_len)) { |
| 283 | syscall_entry_event_unknown(unknown_action_list, regs, id); |
| 284 | return; |
| 285 | } |
| 286 | |
| 287 | entry = &table[id]; |
| 288 | if (!entry->event_func) { |
| 289 | syscall_entry_event_unknown(unknown_action_list, regs, id); |
| 290 | return; |
| 291 | } |
| 292 | |
| 293 | if (unlikely(in_compat_syscall())) { |
| 294 | action_list = &syscall_table->compat_syscall_dispatch[id]; |
| 295 | } else { |
| 296 | action_list = &syscall_table->syscall_dispatch[id]; |
| 297 | } |
| 298 | if (unlikely(hlist_empty(action_list))) |
| 299 | return; |
| 300 | |
| 301 | syscall_entry_event_call_func(action_list, entry->event_func, entry->nrargs, regs); |
| 302 | } |
| 303 | |
| 304 | static void syscall_exit_event_unknown(struct hlist_head *unknown_action_list_head, |
| 305 | struct pt_regs *regs, long id, long ret) |
| 306 | { |
| 307 | unsigned long args[LTTNG_SYSCALL_NR_ARGS]; |
| 308 | struct lttng_kernel_event_common_private *event_priv; |
| 309 | |
| 310 | lttng_syscall_get_arguments(current, regs, args); |
| 311 | lttng_hlist_for_each_entry_rcu(event_priv, unknown_action_list_head, u.syscall.node) { |
| 312 | if (unlikely(in_compat_syscall())) |
| 313 | __event_probe__compat_syscall_exit_unknown(event_priv->pub, id, ret, |
| 314 | args); |
| 315 | else |
| 316 | __event_probe__syscall_exit_unknown(event_priv->pub, id, ret, args); |
| 317 | } |
| 318 | } |
| 319 | |
| 320 | static __always_inline |
| 321 | void syscall_exit_event_call_func(struct hlist_head *action_list, |
| 322 | void *func, unsigned int nrargs, |
| 323 | struct pt_regs *regs, long ret) |
| 324 | { |
| 325 | struct lttng_kernel_event_common_private *event_priv; |
| 326 | |
| 327 | switch (nrargs) { |
| 328 | case 0: |
| 329 | { |
| 330 | void (*fptr)(void *__data, long ret) = func; |
| 331 | |
| 332 | lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node) |
| 333 | fptr(event_priv->pub, ret); |
| 334 | break; |
| 335 | } |
| 336 | case 1: |
| 337 | { |
| 338 | void (*fptr)(void *__data, |
| 339 | long ret, |
| 340 | unsigned long arg0) = func; |
| 341 | unsigned long args[LTTNG_SYSCALL_NR_ARGS]; |
| 342 | |
| 343 | lttng_syscall_get_arguments(current, regs, args); |
| 344 | lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node) |
| 345 | fptr(event_priv->pub, ret, args[0]); |
| 346 | break; |
| 347 | } |
| 348 | case 2: |
| 349 | { |
| 350 | void (*fptr)(void *__data, |
| 351 | long ret, |
| 352 | unsigned long arg0, |
| 353 | unsigned long arg1) = func; |
| 354 | unsigned long args[LTTNG_SYSCALL_NR_ARGS]; |
| 355 | |
| 356 | lttng_syscall_get_arguments(current, regs, args); |
| 357 | lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node) |
| 358 | fptr(event_priv->pub, ret, args[0], args[1]); |
| 359 | break; |
| 360 | } |
| 361 | case 3: |
| 362 | { |
| 363 | void (*fptr)(void *__data, |
| 364 | long ret, |
| 365 | unsigned long arg0, |
| 366 | unsigned long arg1, |
| 367 | unsigned long arg2) = func; |
| 368 | unsigned long args[LTTNG_SYSCALL_NR_ARGS]; |
| 369 | |
| 370 | lttng_syscall_get_arguments(current, regs, args); |
| 371 | lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node) |
| 372 | fptr(event_priv->pub, ret, args[0], args[1], args[2]); |
| 373 | break; |
| 374 | } |
| 375 | case 4: |
| 376 | { |
| 377 | void (*fptr)(void *__data, |
| 378 | long ret, |
| 379 | unsigned long arg0, |
| 380 | unsigned long arg1, |
| 381 | unsigned long arg2, |
| 382 | unsigned long arg3) = func; |
| 383 | unsigned long args[LTTNG_SYSCALL_NR_ARGS]; |
| 384 | |
| 385 | lttng_syscall_get_arguments(current, regs, args); |
| 386 | lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node) |
| 387 | fptr(event_priv->pub, ret, args[0], args[1], args[2], args[3]); |
| 388 | break; |
| 389 | } |
| 390 | case 5: |
| 391 | { |
| 392 | void (*fptr)(void *__data, |
| 393 | long ret, |
| 394 | unsigned long arg0, |
| 395 | unsigned long arg1, |
| 396 | unsigned long arg2, |
| 397 | unsigned long arg3, |
| 398 | unsigned long arg4) = func; |
| 399 | unsigned long args[LTTNG_SYSCALL_NR_ARGS]; |
| 400 | |
| 401 | lttng_syscall_get_arguments(current, regs, args); |
| 402 | lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node) |
| 403 | fptr(event_priv->pub, ret, args[0], args[1], args[2], args[3], args[4]); |
| 404 | break; |
| 405 | } |
| 406 | case 6: |
| 407 | { |
| 408 | void (*fptr)(void *__data, |
| 409 | long ret, |
| 410 | unsigned long arg0, |
| 411 | unsigned long arg1, |
| 412 | unsigned long arg2, |
| 413 | unsigned long arg3, |
| 414 | unsigned long arg4, |
| 415 | unsigned long arg5) = func; |
| 416 | unsigned long args[LTTNG_SYSCALL_NR_ARGS]; |
| 417 | |
| 418 | lttng_syscall_get_arguments(current, regs, args); |
| 419 | lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node) |
| 420 | fptr(event_priv->pub, ret, args[0], args[1], args[2], |
| 421 | args[3], args[4], args[5]); |
| 422 | break; |
| 423 | } |
| 424 | default: |
| 425 | break; |
| 426 | } |
| 427 | } |
| 428 | |
| 429 | void syscall_exit_event_probe(void *__data, struct pt_regs *regs, long ret) |
| 430 | { |
| 431 | struct lttng_kernel_syscall_table *syscall_table = __data; |
| 432 | struct hlist_head *action_list, *unknown_action_list; |
| 433 | const struct trace_syscall_entry *table, *entry; |
| 434 | size_t table_len; |
| 435 | long id; |
| 436 | |
| 437 | id = syscall_get_nr(current, regs); |
| 438 | |
| 439 | if (unlikely(in_compat_syscall())) { |
| 440 | struct lttng_syscall_filter *filter = syscall_table->sc_filter; |
| 441 | |
| 442 | if (id < 0 || id >= NR_compat_syscalls |
| 443 | || (!READ_ONCE(syscall_table->syscall_all_exit) && !test_bit(id, filter->sc_compat_exit))) { |
| 444 | /* System call filtered out. */ |
| 445 | return; |
| 446 | } |
| 447 | table = compat_sc_exit_table.table; |
| 448 | table_len = compat_sc_exit_table.len; |
| 449 | unknown_action_list = &syscall_table->compat_unknown_syscall_exit_dispatch; |
| 450 | } else { |
| 451 | struct lttng_syscall_filter *filter = syscall_table->sc_filter; |
| 452 | |
| 453 | if (id < 0 || id >= NR_syscalls |
| 454 | || (!READ_ONCE(syscall_table->syscall_all_exit) && !test_bit(id, filter->sc_exit))) { |
| 455 | /* System call filtered out. */ |
| 456 | return; |
| 457 | } |
| 458 | table = sc_exit_table.table; |
| 459 | table_len = sc_exit_table.len; |
| 460 | unknown_action_list = &syscall_table->unknown_syscall_exit_dispatch; |
| 461 | } |
| 462 | if (unlikely(id < 0 || id >= table_len)) { |
| 463 | syscall_exit_event_unknown(unknown_action_list, regs, id, ret); |
| 464 | return; |
| 465 | } |
| 466 | |
| 467 | entry = &table[id]; |
| 468 | if (!entry->event_func) { |
| 469 | syscall_exit_event_unknown(unknown_action_list, regs, id, ret); |
| 470 | return; |
| 471 | } |
| 472 | |
| 473 | if (unlikely(in_compat_syscall())) { |
| 474 | action_list = &syscall_table->compat_syscall_exit_dispatch[id]; |
| 475 | } else { |
| 476 | action_list = &syscall_table->syscall_exit_dispatch[id]; |
| 477 | } |
| 478 | if (unlikely(hlist_empty(action_list))) |
| 479 | return; |
| 480 | |
| 481 | syscall_exit_event_call_func(action_list, entry->event_func, entry->nrargs, |
| 482 | regs, ret); |
| 483 | } |
| 484 | |
| 485 | static |
| 486 | struct lttng_kernel_syscall_table *get_syscall_table_from_enabler(struct lttng_event_enabler_common *event_enabler) |
| 487 | { |
| 488 | switch (event_enabler->enabler_type) { |
| 489 | case LTTNG_EVENT_ENABLER_TYPE_RECORDER: |
| 490 | { |
| 491 | struct lttng_event_recorder_enabler *event_recorder_enabler = |
| 492 | container_of(event_enabler, struct lttng_event_recorder_enabler, parent); |
| 493 | return &event_recorder_enabler->chan->priv->parent.syscall_table; |
| 494 | } |
| 495 | case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER: |
| 496 | { |
| 497 | struct lttng_event_notifier_enabler *event_notifier_enabler = |
| 498 | container_of(event_enabler, struct lttng_event_notifier_enabler, parent); |
| 499 | return &event_notifier_enabler->group->syscall_table; |
| 500 | } |
| 501 | default: |
| 502 | return NULL; |
| 503 | } |
| 504 | } |
| 505 | |
| 506 | static |
| 507 | struct lttng_kernel_syscall_table *get_syscall_table_from_event(struct lttng_kernel_event_common *event) |
| 508 | { |
| 509 | switch (event->type) { |
| 510 | case LTTNG_KERNEL_EVENT_TYPE_RECORDER: |
| 511 | { |
| 512 | struct lttng_kernel_event_recorder *event_recorder = |
| 513 | container_of(event, struct lttng_kernel_event_recorder, parent); |
| 514 | return &event_recorder->chan->priv->parent.syscall_table; |
| 515 | } |
| 516 | case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER: |
| 517 | { |
| 518 | struct lttng_kernel_event_notifier *event_notifier = |
| 519 | container_of(event, struct lttng_kernel_event_notifier, parent); |
| 520 | return &event_notifier->priv->group->syscall_table; |
| 521 | } |
| 522 | default: |
| 523 | return NULL; |
| 524 | } |
| 525 | } |
| 526 | |
| 527 | static |
| 528 | void lttng_syscall_event_enabler_create_event(struct lttng_event_enabler_common *syscall_event_enabler, |
| 529 | const struct lttng_kernel_event_desc *desc, struct hlist_head *dispatch_table, |
| 530 | enum sc_type type, unsigned int syscall_nr) |
| 531 | { |
| 532 | struct lttng_kernel_event_common *event; |
| 533 | |
| 534 | switch (syscall_event_enabler->enabler_type) { |
| 535 | case LTTNG_EVENT_ENABLER_TYPE_RECORDER: |
| 536 | { |
| 537 | struct lttng_event_recorder_enabler *syscall_event_recorder_enabler = |
| 538 | container_of(syscall_event_enabler, struct lttng_event_recorder_enabler, parent); |
| 539 | struct lttng_event_recorder_enabler *event_recorder_enabler; |
| 540 | struct lttng_kernel_abi_event ev; |
| 541 | |
| 542 | /* We need to create an event for this syscall/enabler. */ |
| 543 | memset(&ev, 0, sizeof(ev)); |
| 544 | switch (type) { |
| 545 | case SC_TYPE_ENTRY: |
| 546 | ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY; |
| 547 | ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE; |
| 548 | break; |
| 549 | case SC_TYPE_EXIT: |
| 550 | ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT; |
| 551 | ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE; |
| 552 | break; |
| 553 | case SC_TYPE_COMPAT_ENTRY: |
| 554 | ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY; |
| 555 | ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT; |
| 556 | break; |
| 557 | case SC_TYPE_COMPAT_EXIT: |
| 558 | ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT; |
| 559 | ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT; |
| 560 | break; |
| 561 | } |
| 562 | strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1); |
| 563 | ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0'; |
| 564 | ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL; |
| 565 | event_recorder_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, |
| 566 | syscall_event_recorder_enabler->chan); |
| 567 | WARN_ON_ONCE(!event_recorder_enabler); |
| 568 | if (!event_recorder_enabler) |
| 569 | return; |
| 570 | event = _lttng_kernel_event_create(&event_recorder_enabler->parent, desc); |
| 571 | WARN_ON_ONCE(IS_ERR(event)); |
| 572 | lttng_event_enabler_destroy(&event_recorder_enabler->parent); |
| 573 | if (IS_ERR(event)) { |
| 574 | printk(KERN_INFO "Unable to create event recorder %s\n", desc->event_name); |
| 575 | return; |
| 576 | } |
| 577 | event->priv->u.syscall.syscall_id = syscall_nr; |
| 578 | if (dispatch_table) |
| 579 | hlist_add_head_rcu(&event->priv->u.syscall.node, dispatch_table); |
| 580 | break; |
| 581 | } |
| 582 | case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER: |
| 583 | { |
| 584 | struct lttng_event_notifier_enabler *syscall_event_notifier_enabler = |
| 585 | container_of(syscall_event_enabler, struct lttng_event_notifier_enabler, parent); |
| 586 | struct lttng_event_notifier_enabler *event_notifier_enabler; |
| 587 | struct lttng_kernel_abi_event_notifier event_notifier_param; |
| 588 | uint64_t user_token = syscall_event_enabler->user_token; |
| 589 | uint64_t error_counter_index = syscall_event_notifier_enabler->error_counter_index; |
| 590 | |
| 591 | memset(&event_notifier_param, 0, sizeof(event_notifier_param)); |
| 592 | switch (type) { |
| 593 | case SC_TYPE_ENTRY: |
| 594 | event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY; |
| 595 | event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE; |
| 596 | break; |
| 597 | case SC_TYPE_EXIT: |
| 598 | event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT; |
| 599 | event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE; |
| 600 | break; |
| 601 | case SC_TYPE_COMPAT_ENTRY: |
| 602 | event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY; |
| 603 | event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT; |
| 604 | break; |
| 605 | case SC_TYPE_COMPAT_EXIT: |
| 606 | event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT; |
| 607 | event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT; |
| 608 | break; |
| 609 | } |
| 610 | strncat(event_notifier_param.event.name, desc->event_name, |
| 611 | LTTNG_KERNEL_ABI_SYM_NAME_LEN - strlen(event_notifier_param.event.name) - 1); |
| 612 | event_notifier_param.event.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0'; |
| 613 | event_notifier_param.event.instrumentation = LTTNG_KERNEL_ABI_SYSCALL; |
| 614 | event_notifier_param.event.token = user_token; |
| 615 | event_notifier_param.error_counter_index = error_counter_index; |
| 616 | |
| 617 | event_notifier_enabler = lttng_event_notifier_enabler_create(LTTNG_ENABLER_FORMAT_NAME, |
| 618 | &event_notifier_param, syscall_event_notifier_enabler->group); |
| 619 | WARN_ON_ONCE(!event_notifier_enabler); |
| 620 | event = _lttng_kernel_event_create(&event_notifier_enabler->parent, desc); |
| 621 | WARN_ON_ONCE(IS_ERR(event)); |
| 622 | lttng_event_enabler_destroy(&event_notifier_enabler->parent); |
| 623 | if (IS_ERR(event)) { |
| 624 | printk(KERN_INFO "Unable to create event notifier %s\n", desc->event_name); |
| 625 | return; |
| 626 | } |
| 627 | event->priv->u.syscall.syscall_id = syscall_nr; |
| 628 | if (dispatch_table) |
| 629 | hlist_add_head_rcu(&event->priv->u.syscall.node, dispatch_table); |
| 630 | break; |
| 631 | } |
| 632 | default: |
| 633 | break; |
| 634 | } |
| 635 | } |
| 636 | |
| 637 | static |
| 638 | void lttng_syscall_event_enabler_create_matching_syscall_table_events(struct lttng_event_enabler_common *syscall_event_enabler_common, |
| 639 | const struct trace_syscall_entry *table, size_t table_len, enum sc_type type) |
| 640 | { |
| 641 | struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(syscall_event_enabler_common); |
| 642 | const struct lttng_kernel_event_desc *desc; |
| 643 | unsigned int i; |
| 644 | |
| 645 | if (!IS_ENABLED(CONFIG_COMPAT) && (type == SC_TYPE_COMPAT_ENTRY || type == SC_TYPE_COMPAT_EXIT)) |
| 646 | return; |
| 647 | |
| 648 | /* iterate over all syscall and create event that match */ |
| 649 | for (i = 0; i < table_len; i++) { |
| 650 | struct lttng_kernel_event_common_private *event_priv; |
| 651 | struct hlist_head *head; |
| 652 | bool found = false; |
| 653 | |
| 654 | desc = table[i].desc; |
| 655 | if (!desc) { |
| 656 | /* Unknown syscall */ |
| 657 | continue; |
| 658 | } |
| 659 | |
| 660 | if (!lttng_desc_match_enabler(desc, syscall_event_enabler_common)) |
| 661 | continue; |
| 662 | |
| 663 | /* |
| 664 | * Check if already created. |
| 665 | */ |
| 666 | head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, desc->event_name); |
| 667 | lttng_hlist_for_each_entry(event_priv, head, hlist_node) { |
| 668 | if (lttng_event_enabler_desc_match_event(syscall_event_enabler_common, desc, event_priv->pub)) { |
| 669 | found = true; |
| 670 | break; |
| 671 | } |
| 672 | } |
| 673 | if (found) |
| 674 | continue; |
| 675 | |
| 676 | lttng_syscall_event_enabler_create_event(syscall_event_enabler_common, desc, NULL, type, i); |
| 677 | } |
| 678 | } |
| 679 | |
| 680 | static |
| 681 | bool lttng_syscall_event_enabler_is_wildcard_all(struct lttng_event_enabler_common *event_enabler) |
| 682 | { |
| 683 | if (event_enabler->event_param.instrumentation != LTTNG_KERNEL_ABI_SYSCALL) |
| 684 | return false; |
| 685 | if (event_enabler->event_param.u.syscall.abi != LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL) |
| 686 | return false; |
| 687 | if (event_enabler->event_param.u.syscall.match != LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME) |
| 688 | return false; |
| 689 | if (strcmp(event_enabler->event_param.name, "*")) |
| 690 | return false; |
| 691 | return true; |
| 692 | } |
| 693 | |
| 694 | static |
| 695 | void create_unknown_syscall_event(struct lttng_event_enabler_common *event_enabler, enum sc_type type) |
| 696 | { |
| 697 | struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(event_enabler); |
| 698 | struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(event_enabler); |
| 699 | struct lttng_kernel_event_common_private *event_priv; |
| 700 | const struct lttng_kernel_event_desc *desc; |
| 701 | struct hlist_head *unknown_dispatch_list; |
| 702 | bool found = false; |
| 703 | struct hlist_head *head; |
| 704 | |
| 705 | if (!IS_ENABLED(CONFIG_COMPAT) && (type == SC_TYPE_COMPAT_ENTRY || type == SC_TYPE_COMPAT_EXIT)) |
| 706 | return; |
| 707 | |
| 708 | /* |
| 709 | * Considering that currently system calls can only be enabled on a per |
| 710 | * name basis (or wildcard based on a name), unknown syscall events are |
| 711 | * only used when matching *all* system calls, because this is the only |
| 712 | * case which can be associated with an unknown system call. |
| 713 | * |
| 714 | * When enabling system call on a per system call number basis will be |
| 715 | * supported, this will need to be revisited. |
| 716 | */ |
| 717 | if (!lttng_syscall_event_enabler_is_wildcard_all(event_enabler)) |
| 718 | return; |
| 719 | |
| 720 | switch (type) { |
| 721 | case SC_TYPE_ENTRY: |
| 722 | desc = &__event_desc___syscall_entry_unknown; |
| 723 | unknown_dispatch_list = &syscall_table->unknown_syscall_dispatch; |
| 724 | break; |
| 725 | case SC_TYPE_EXIT: |
| 726 | desc = &__event_desc___syscall_exit_unknown; |
| 727 | unknown_dispatch_list = &syscall_table->unknown_syscall_exit_dispatch; |
| 728 | break; |
| 729 | case SC_TYPE_COMPAT_ENTRY: |
| 730 | desc = &__event_desc___compat_syscall_entry_unknown; |
| 731 | unknown_dispatch_list = &syscall_table->compat_unknown_syscall_dispatch; |
| 732 | break; |
| 733 | case SC_TYPE_COMPAT_EXIT: |
| 734 | desc = &__event_desc___compat_syscall_exit_unknown; |
| 735 | unknown_dispatch_list = &syscall_table->compat_unknown_syscall_exit_dispatch; |
| 736 | break; |
| 737 | default: |
| 738 | WARN_ON_ONCE(1); |
| 739 | } |
| 740 | |
| 741 | /* |
| 742 | * Check if already created. |
| 743 | */ |
| 744 | head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, desc->event_name); |
| 745 | lttng_hlist_for_each_entry(event_priv, head, hlist_node) { |
| 746 | if (lttng_event_enabler_desc_match_event(event_enabler, desc, event_priv->pub)) { |
| 747 | found = true; |
| 748 | break; |
| 749 | } |
| 750 | } |
| 751 | if (!found) |
| 752 | lttng_syscall_event_enabler_create_event(event_enabler, desc, unknown_dispatch_list, type, -1U); |
| 753 | } |
| 754 | |
| 755 | static |
| 756 | void lttng_syscall_event_enabler_create_matching_events(struct lttng_event_enabler_common *event_enabler) |
| 757 | { |
| 758 | enum lttng_kernel_abi_syscall_entryexit entryexit = event_enabler->event_param.u.syscall.entryexit; |
| 759 | |
| 760 | if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT) { |
| 761 | lttng_syscall_event_enabler_create_matching_syscall_table_events(event_enabler, |
| 762 | sc_table.table, sc_table.len, SC_TYPE_ENTRY); |
| 763 | lttng_syscall_event_enabler_create_matching_syscall_table_events(event_enabler, |
| 764 | compat_sc_table.table, compat_sc_table.len, SC_TYPE_COMPAT_ENTRY); |
| 765 | create_unknown_syscall_event(event_enabler, SC_TYPE_ENTRY); |
| 766 | create_unknown_syscall_event(event_enabler, SC_TYPE_COMPAT_ENTRY); |
| 767 | } |
| 768 | |
| 769 | if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT) { |
| 770 | lttng_syscall_event_enabler_create_matching_syscall_table_events(event_enabler, |
| 771 | sc_exit_table.table, sc_exit_table.len, SC_TYPE_EXIT); |
| 772 | lttng_syscall_event_enabler_create_matching_syscall_table_events(event_enabler, |
| 773 | compat_sc_exit_table.table, compat_sc_exit_table.len, SC_TYPE_COMPAT_EXIT); |
| 774 | create_unknown_syscall_event(event_enabler, SC_TYPE_EXIT); |
| 775 | create_unknown_syscall_event(event_enabler, SC_TYPE_COMPAT_EXIT); |
| 776 | } |
| 777 | } |
| 778 | |
| 779 | /* |
| 780 | * Should be called with sessions lock held. |
| 781 | */ |
| 782 | int lttng_event_enabler_create_syscall_events_if_missing(struct lttng_event_enabler_common *syscall_event_enabler) |
| 783 | { |
| 784 | struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(syscall_event_enabler); |
| 785 | int ret; |
| 786 | |
| 787 | if (!syscall_table->syscall_dispatch) { |
| 788 | /* create syscall table mapping syscall to events */ |
| 789 | syscall_table->syscall_dispatch = kzalloc(sizeof(struct hlist_head) * sc_table.len, GFP_KERNEL); |
| 790 | if (!syscall_table->syscall_dispatch) |
| 791 | return -ENOMEM; |
| 792 | } |
| 793 | if (!syscall_table->syscall_exit_dispatch) { |
| 794 | /* create syscall table mapping syscall to events */ |
| 795 | syscall_table->syscall_exit_dispatch = kzalloc(sizeof(struct hlist_head) * sc_exit_table.len, GFP_KERNEL); |
| 796 | if (!syscall_table->syscall_exit_dispatch) |
| 797 | return -ENOMEM; |
| 798 | } |
| 799 | |
| 800 | #ifdef CONFIG_COMPAT |
| 801 | if (!syscall_table->compat_syscall_dispatch) { |
| 802 | /* create syscall table mapping compat syscall to events */ |
| 803 | syscall_table->compat_syscall_dispatch = kzalloc(sizeof(struct hlist_head) * compat_sc_table.len, GFP_KERNEL); |
| 804 | if (!syscall_table->compat_syscall_dispatch) |
| 805 | return -ENOMEM; |
| 806 | } |
| 807 | |
| 808 | if (!syscall_table->compat_syscall_exit_dispatch) { |
| 809 | /* create syscall table mapping compat syscall to events */ |
| 810 | syscall_table->compat_syscall_exit_dispatch = kzalloc(sizeof(struct hlist_head) * compat_sc_exit_table.len, GFP_KERNEL); |
| 811 | if (!syscall_table->compat_syscall_exit_dispatch) |
| 812 | return -ENOMEM; |
| 813 | } |
| 814 | #endif |
| 815 | if (!syscall_table->sc_filter) { |
| 816 | syscall_table->sc_filter = kzalloc(sizeof(struct lttng_syscall_filter), |
| 817 | GFP_KERNEL); |
| 818 | if (!syscall_table->sc_filter) |
| 819 | return -ENOMEM; |
| 820 | } |
| 821 | |
| 822 | if (!syscall_table->sys_enter_registered) { |
| 823 | ret = lttng_wrapper_tracepoint_probe_register("sys_enter", |
| 824 | (void *) syscall_entry_event_probe, syscall_table); |
| 825 | if (ret) |
| 826 | return ret; |
| 827 | syscall_table->sys_enter_registered = 1; |
| 828 | } |
| 829 | if (!syscall_table->sys_exit_registered) { |
| 830 | ret = lttng_wrapper_tracepoint_probe_register("sys_exit", |
| 831 | (void *) syscall_exit_event_probe, syscall_table); |
| 832 | if (ret) { |
| 833 | WARN_ON_ONCE(lttng_wrapper_tracepoint_probe_unregister("sys_enter", |
| 834 | (void *) syscall_entry_event_probe, syscall_table)); |
| 835 | return ret; |
| 836 | } |
| 837 | syscall_table->sys_exit_registered = 1; |
| 838 | } |
| 839 | |
| 840 | lttng_syscall_event_enabler_create_matching_events(syscall_event_enabler); |
| 841 | |
| 842 | return ret; |
| 843 | } |
| 844 | |
| 845 | int lttng_syscalls_unregister_syscall_table(struct lttng_kernel_syscall_table *syscall_table) |
| 846 | { |
| 847 | int ret; |
| 848 | |
| 849 | if (!syscall_table->syscall_dispatch) |
| 850 | return 0; |
| 851 | if (syscall_table->sys_enter_registered) { |
| 852 | ret = lttng_wrapper_tracepoint_probe_unregister("sys_enter", |
| 853 | (void *) syscall_entry_event_probe, syscall_table); |
| 854 | if (ret) |
| 855 | return ret; |
| 856 | syscall_table->sys_enter_registered = 0; |
| 857 | } |
| 858 | if (syscall_table->sys_exit_registered) { |
| 859 | ret = lttng_wrapper_tracepoint_probe_unregister("sys_exit", |
| 860 | (void *) syscall_exit_event_probe, syscall_table); |
| 861 | if (ret) |
| 862 | return ret; |
| 863 | syscall_table->sys_exit_registered = 0; |
| 864 | } |
| 865 | return 0; |
| 866 | } |
| 867 | |
| 868 | int lttng_syscalls_destroy_syscall_table(struct lttng_kernel_syscall_table *syscall_table) |
| 869 | { |
| 870 | kfree(syscall_table->syscall_dispatch); |
| 871 | kfree(syscall_table->syscall_exit_dispatch); |
| 872 | #ifdef CONFIG_COMPAT |
| 873 | kfree(syscall_table->compat_syscall_dispatch); |
| 874 | kfree(syscall_table->compat_syscall_exit_dispatch); |
| 875 | #endif |
| 876 | kfree(syscall_table->sc_filter); |
| 877 | return 0; |
| 878 | } |
| 879 | |
| 880 | static |
| 881 | int get_syscall_nr(const char *syscall_name) |
| 882 | { |
| 883 | int syscall_nr = -1; |
| 884 | int i; |
| 885 | |
| 886 | for (i = 0; i < sc_table.len; i++) { |
| 887 | const struct trace_syscall_entry *entry; |
| 888 | const char *it_name; |
| 889 | |
| 890 | entry = &sc_table.table[i]; |
| 891 | if (!entry->desc) |
| 892 | continue; |
| 893 | it_name = entry->desc->event_name; |
| 894 | it_name += strlen(SYSCALL_ENTRY_STR); |
| 895 | if (!strcmp(syscall_name, it_name)) { |
| 896 | syscall_nr = i; |
| 897 | break; |
| 898 | } |
| 899 | } |
| 900 | return syscall_nr; |
| 901 | } |
| 902 | |
| 903 | static |
| 904 | int get_compat_syscall_nr(const char *syscall_name) |
| 905 | { |
| 906 | int syscall_nr = -1; |
| 907 | int i; |
| 908 | |
| 909 | for (i = 0; i < compat_sc_table.len; i++) { |
| 910 | const struct trace_syscall_entry *entry; |
| 911 | const char *it_name; |
| 912 | |
| 913 | entry = &compat_sc_table.table[i]; |
| 914 | if (!entry->desc) |
| 915 | continue; |
| 916 | it_name = entry->desc->event_name; |
| 917 | it_name += strlen(COMPAT_SYSCALL_ENTRY_STR); |
| 918 | if (!strcmp(syscall_name, it_name)) { |
| 919 | syscall_nr = i; |
| 920 | break; |
| 921 | } |
| 922 | } |
| 923 | return syscall_nr; |
| 924 | } |
| 925 | |
| 926 | static |
| 927 | uint32_t get_sc_tables_len(void) |
| 928 | { |
| 929 | return sc_table.len + compat_sc_table.len; |
| 930 | } |
| 931 | |
| 932 | static |
| 933 | const char *get_syscall_name(const char *desc_name, |
| 934 | enum lttng_syscall_abi abi, |
| 935 | enum lttng_syscall_entryexit entryexit) |
| 936 | { |
| 937 | size_t prefix_len = 0; |
| 938 | |
| 939 | |
| 940 | switch (entryexit) { |
| 941 | case LTTNG_SYSCALL_ENTRY: |
| 942 | switch (abi) { |
| 943 | case LTTNG_SYSCALL_ABI_NATIVE: |
| 944 | prefix_len = strlen(SYSCALL_ENTRY_STR); |
| 945 | break; |
| 946 | case LTTNG_SYSCALL_ABI_COMPAT: |
| 947 | prefix_len = strlen(COMPAT_SYSCALL_ENTRY_STR); |
| 948 | break; |
| 949 | } |
| 950 | break; |
| 951 | case LTTNG_SYSCALL_EXIT: |
| 952 | switch (abi) { |
| 953 | case LTTNG_SYSCALL_ABI_NATIVE: |
| 954 | prefix_len = strlen(SYSCALL_EXIT_STR); |
| 955 | break; |
| 956 | case LTTNG_SYSCALL_ABI_COMPAT: |
| 957 | prefix_len = strlen(COMPAT_SYSCALL_EXIT_STR); |
| 958 | break; |
| 959 | } |
| 960 | break; |
| 961 | } |
| 962 | WARN_ON_ONCE(prefix_len == 0); |
| 963 | return desc_name + prefix_len; |
| 964 | } |
| 965 | |
| 966 | static |
| 967 | int lttng_syscall_filter_enable( |
| 968 | struct lttng_syscall_filter *filter, |
| 969 | const char *desc_name, enum lttng_syscall_abi abi, |
| 970 | enum lttng_syscall_entryexit entryexit) |
| 971 | { |
| 972 | const char *syscall_name; |
| 973 | unsigned long *bitmap; |
| 974 | int syscall_nr; |
| 975 | |
| 976 | syscall_name = get_syscall_name(desc_name, abi, entryexit); |
| 977 | |
| 978 | switch (abi) { |
| 979 | case LTTNG_SYSCALL_ABI_NATIVE: |
| 980 | syscall_nr = get_syscall_nr(syscall_name); |
| 981 | break; |
| 982 | case LTTNG_SYSCALL_ABI_COMPAT: |
| 983 | syscall_nr = get_compat_syscall_nr(syscall_name); |
| 984 | break; |
| 985 | default: |
| 986 | return -EINVAL; |
| 987 | } |
| 988 | if (syscall_nr < 0) |
| 989 | return -ENOENT; |
| 990 | |
| 991 | switch (entryexit) { |
| 992 | case LTTNG_SYSCALL_ENTRY: |
| 993 | switch (abi) { |
| 994 | case LTTNG_SYSCALL_ABI_NATIVE: |
| 995 | bitmap = filter->sc_entry; |
| 996 | break; |
| 997 | case LTTNG_SYSCALL_ABI_COMPAT: |
| 998 | bitmap = filter->sc_compat_entry; |
| 999 | break; |
| 1000 | default: |
| 1001 | return -EINVAL; |
| 1002 | } |
| 1003 | break; |
| 1004 | case LTTNG_SYSCALL_EXIT: |
| 1005 | switch (abi) { |
| 1006 | case LTTNG_SYSCALL_ABI_NATIVE: |
| 1007 | bitmap = filter->sc_exit; |
| 1008 | break; |
| 1009 | case LTTNG_SYSCALL_ABI_COMPAT: |
| 1010 | bitmap = filter->sc_compat_exit; |
| 1011 | break; |
| 1012 | default: |
| 1013 | return -EINVAL; |
| 1014 | } |
| 1015 | break; |
| 1016 | default: |
| 1017 | return -EINVAL; |
| 1018 | } |
| 1019 | if (test_bit(syscall_nr, bitmap)) |
| 1020 | return -EEXIST; |
| 1021 | bitmap_set(bitmap, syscall_nr, 1); |
| 1022 | return 0; |
| 1023 | } |
| 1024 | |
| 1025 | int lttng_syscall_filter_enable_event(struct lttng_kernel_event_common *event) |
| 1026 | { |
| 1027 | struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_event(event); |
| 1028 | unsigned int syscall_id = event->priv->u.syscall.syscall_id; |
| 1029 | struct hlist_head *dispatch_list; |
| 1030 | int ret; |
| 1031 | |
| 1032 | WARN_ON_ONCE(event->priv->instrumentation != LTTNG_KERNEL_ABI_SYSCALL); |
| 1033 | |
| 1034 | ret = lttng_syscall_filter_enable(syscall_table->sc_filter, |
| 1035 | event->priv->desc->event_name, event->priv->u.syscall.abi, |
| 1036 | event->priv->u.syscall.entryexit); |
| 1037 | if (ret) |
| 1038 | return ret; |
| 1039 | |
| 1040 | switch (event->priv->u.syscall.entryexit) { |
| 1041 | case LTTNG_SYSCALL_ENTRY: |
| 1042 | switch (event->priv->u.syscall.abi) { |
| 1043 | case LTTNG_SYSCALL_ABI_NATIVE: |
| 1044 | dispatch_list = &syscall_table->syscall_dispatch[syscall_id]; |
| 1045 | break; |
| 1046 | case LTTNG_SYSCALL_ABI_COMPAT: |
| 1047 | dispatch_list = &syscall_table->compat_syscall_dispatch[syscall_id]; |
| 1048 | break; |
| 1049 | default: |
| 1050 | ret = -EINVAL; |
| 1051 | goto end; |
| 1052 | } |
| 1053 | break; |
| 1054 | case LTTNG_SYSCALL_EXIT: |
| 1055 | switch (event->priv->u.syscall.abi) { |
| 1056 | case LTTNG_SYSCALL_ABI_NATIVE: |
| 1057 | dispatch_list = &syscall_table->syscall_exit_dispatch[syscall_id]; |
| 1058 | break; |
| 1059 | case LTTNG_SYSCALL_ABI_COMPAT: |
| 1060 | dispatch_list = &syscall_table->compat_syscall_exit_dispatch[syscall_id]; |
| 1061 | break; |
| 1062 | default: |
| 1063 | ret = -EINVAL; |
| 1064 | goto end; |
| 1065 | } |
| 1066 | break; |
| 1067 | default: |
| 1068 | ret = -EINVAL; |
| 1069 | goto end; |
| 1070 | } |
| 1071 | |
| 1072 | hlist_add_head_rcu(&event->priv->u.syscall.node, dispatch_list); |
| 1073 | end: |
| 1074 | return ret; |
| 1075 | } |
| 1076 | |
| 1077 | static |
| 1078 | int lttng_syscall_filter_disable(struct lttng_syscall_filter *filter, |
| 1079 | const char *desc_name, enum lttng_syscall_abi abi, |
| 1080 | enum lttng_syscall_entryexit entryexit) |
| 1081 | { |
| 1082 | const char *syscall_name; |
| 1083 | unsigned long *bitmap; |
| 1084 | int syscall_nr; |
| 1085 | |
| 1086 | syscall_name = get_syscall_name(desc_name, abi, entryexit); |
| 1087 | |
| 1088 | switch (abi) { |
| 1089 | case LTTNG_SYSCALL_ABI_NATIVE: |
| 1090 | syscall_nr = get_syscall_nr(syscall_name); |
| 1091 | break; |
| 1092 | case LTTNG_SYSCALL_ABI_COMPAT: |
| 1093 | syscall_nr = get_compat_syscall_nr(syscall_name); |
| 1094 | break; |
| 1095 | default: |
| 1096 | return -EINVAL; |
| 1097 | } |
| 1098 | if (syscall_nr < 0) |
| 1099 | return -ENOENT; |
| 1100 | |
| 1101 | switch (entryexit) { |
| 1102 | case LTTNG_SYSCALL_ENTRY: |
| 1103 | switch (abi) { |
| 1104 | case LTTNG_SYSCALL_ABI_NATIVE: |
| 1105 | bitmap = filter->sc_entry; |
| 1106 | break; |
| 1107 | case LTTNG_SYSCALL_ABI_COMPAT: |
| 1108 | bitmap = filter->sc_compat_entry; |
| 1109 | break; |
| 1110 | default: |
| 1111 | return -EINVAL; |
| 1112 | } |
| 1113 | break; |
| 1114 | case LTTNG_SYSCALL_EXIT: |
| 1115 | switch (abi) { |
| 1116 | case LTTNG_SYSCALL_ABI_NATIVE: |
| 1117 | bitmap = filter->sc_exit; |
| 1118 | break; |
| 1119 | case LTTNG_SYSCALL_ABI_COMPAT: |
| 1120 | bitmap = filter->sc_compat_exit; |
| 1121 | break; |
| 1122 | default: |
| 1123 | return -EINVAL; |
| 1124 | } |
| 1125 | break; |
| 1126 | default: |
| 1127 | return -EINVAL; |
| 1128 | } |
| 1129 | if (!test_bit(syscall_nr, bitmap)) |
| 1130 | return -EEXIST; |
| 1131 | bitmap_clear(bitmap, syscall_nr, 1); |
| 1132 | |
| 1133 | return 0; |
| 1134 | } |
| 1135 | |
| 1136 | int lttng_syscall_filter_disable_event(struct lttng_kernel_event_common *event) |
| 1137 | { |
| 1138 | struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_event(event); |
| 1139 | int ret; |
| 1140 | |
| 1141 | ret = lttng_syscall_filter_disable(syscall_table->sc_filter, |
| 1142 | event->priv->desc->event_name, event->priv->u.syscall.abi, |
| 1143 | event->priv->u.syscall.entryexit); |
| 1144 | if (ret) |
| 1145 | return ret; |
| 1146 | hlist_del_rcu(&event->priv->u.syscall.node); |
| 1147 | return 0; |
| 1148 | } |
| 1149 | |
| 1150 | void lttng_syscall_table_set_wildcard_all(struct lttng_event_enabler_common *event_enabler) |
| 1151 | { |
| 1152 | struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(event_enabler); |
| 1153 | enum lttng_kernel_abi_syscall_entryexit entryexit; |
| 1154 | int enabled = event_enabler->enabled; |
| 1155 | |
| 1156 | if (!lttng_syscall_event_enabler_is_wildcard_all(event_enabler)) |
| 1157 | return; |
| 1158 | entryexit = event_enabler->event_param.u.syscall.entryexit; |
| 1159 | if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT) |
| 1160 | WRITE_ONCE(syscall_table->syscall_all_entry, enabled); |
| 1161 | |
| 1162 | if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT) |
| 1163 | WRITE_ONCE(syscall_table->syscall_all_exit, enabled); |
| 1164 | } |
| 1165 | |
| 1166 | static |
| 1167 | const struct trace_syscall_entry *syscall_list_get_entry(loff_t *pos) |
| 1168 | { |
| 1169 | const struct trace_syscall_entry *entry; |
| 1170 | int iter = 0; |
| 1171 | |
| 1172 | for (entry = sc_table.table; |
| 1173 | entry < sc_table.table + sc_table.len; |
| 1174 | entry++) { |
| 1175 | if (iter++ >= *pos) |
| 1176 | return entry; |
| 1177 | } |
| 1178 | for (entry = compat_sc_table.table; |
| 1179 | entry < compat_sc_table.table + compat_sc_table.len; |
| 1180 | entry++) { |
| 1181 | if (iter++ >= *pos) |
| 1182 | return entry; |
| 1183 | } |
| 1184 | /* End of list */ |
| 1185 | return NULL; |
| 1186 | } |
| 1187 | |
| 1188 | static |
| 1189 | void *syscall_list_start(struct seq_file *m, loff_t *pos) |
| 1190 | { |
| 1191 | return (void *) syscall_list_get_entry(pos); |
| 1192 | } |
| 1193 | |
| 1194 | static |
| 1195 | void *syscall_list_next(struct seq_file *m, void *p, loff_t *ppos) |
| 1196 | { |
| 1197 | (*ppos)++; |
| 1198 | return (void *) syscall_list_get_entry(ppos); |
| 1199 | } |
| 1200 | |
| 1201 | static |
| 1202 | void syscall_list_stop(struct seq_file *m, void *p) |
| 1203 | { |
| 1204 | } |
| 1205 | |
| 1206 | static |
| 1207 | int get_sc_table(const struct trace_syscall_entry *entry, |
| 1208 | const struct trace_syscall_entry **table, |
| 1209 | unsigned int *bitness) |
| 1210 | { |
| 1211 | if (entry >= sc_table.table && entry < sc_table.table + sc_table.len) { |
| 1212 | if (bitness) |
| 1213 | *bitness = BITS_PER_LONG; |
| 1214 | if (table) |
| 1215 | *table = sc_table.table; |
| 1216 | return 0; |
| 1217 | } |
| 1218 | if (!(entry >= compat_sc_table.table |
| 1219 | && entry < compat_sc_table.table + compat_sc_table.len)) { |
| 1220 | return -EINVAL; |
| 1221 | } |
| 1222 | if (bitness) |
| 1223 | *bitness = 32; |
| 1224 | if (table) |
| 1225 | *table = compat_sc_table.table; |
| 1226 | return 0; |
| 1227 | } |
| 1228 | |
| 1229 | static |
| 1230 | int syscall_list_show(struct seq_file *m, void *p) |
| 1231 | { |
| 1232 | const struct trace_syscall_entry *table, *entry = p; |
| 1233 | unsigned int bitness; |
| 1234 | unsigned long index; |
| 1235 | int ret; |
| 1236 | const char *name; |
| 1237 | |
| 1238 | ret = get_sc_table(entry, &table, &bitness); |
| 1239 | if (ret) |
| 1240 | return ret; |
| 1241 | if (!entry->desc) |
| 1242 | return 0; |
| 1243 | if (table == sc_table.table) { |
| 1244 | index = entry - table; |
| 1245 | name = &entry->desc->event_name[strlen(SYSCALL_ENTRY_STR)]; |
| 1246 | } else { |
| 1247 | index = (entry - table) + sc_table.len; |
| 1248 | name = &entry->desc->event_name[strlen(COMPAT_SYSCALL_ENTRY_STR)]; |
| 1249 | } |
| 1250 | seq_printf(m, "syscall { index = %lu; name = %s; bitness = %u; };\n", |
| 1251 | index, name, bitness); |
| 1252 | return 0; |
| 1253 | } |
| 1254 | |
| 1255 | static |
| 1256 | const struct seq_operations lttng_syscall_list_seq_ops = { |
| 1257 | .start = syscall_list_start, |
| 1258 | .next = syscall_list_next, |
| 1259 | .stop = syscall_list_stop, |
| 1260 | .show = syscall_list_show, |
| 1261 | }; |
| 1262 | |
| 1263 | static |
| 1264 | int lttng_syscall_list_open(struct inode *inode, struct file *file) |
| 1265 | { |
| 1266 | return seq_open(file, <tng_syscall_list_seq_ops); |
| 1267 | } |
| 1268 | |
| 1269 | const struct file_operations lttng_syscall_list_fops = { |
| 1270 | .owner = THIS_MODULE, |
| 1271 | .open = lttng_syscall_list_open, |
| 1272 | .read = seq_read, |
| 1273 | .llseek = seq_lseek, |
| 1274 | .release = seq_release, |
| 1275 | }; |
| 1276 | |
| 1277 | /* |
| 1278 | * A syscall is enabled if it is traced for either entry or exit. |
| 1279 | */ |
| 1280 | long lttng_syscall_table_get_active_mask(struct lttng_kernel_syscall_table *syscall_table, |
| 1281 | struct lttng_kernel_abi_syscall_mask __user *usyscall_mask) |
| 1282 | { |
| 1283 | uint32_t len, sc_tables_len, bitmask_len; |
| 1284 | int ret = 0, bit; |
| 1285 | char *tmp_mask; |
| 1286 | struct lttng_syscall_filter *filter; |
| 1287 | |
| 1288 | ret = get_user(len, &usyscall_mask->len); |
| 1289 | if (ret) |
| 1290 | return ret; |
| 1291 | sc_tables_len = get_sc_tables_len(); |
| 1292 | bitmask_len = ALIGN(sc_tables_len, 8) >> 3; |
| 1293 | if (len < sc_tables_len) { |
| 1294 | return put_user(sc_tables_len, &usyscall_mask->len); |
| 1295 | } |
| 1296 | /* Array is large enough, we can copy array to user-space. */ |
| 1297 | tmp_mask = kzalloc(bitmask_len, GFP_KERNEL); |
| 1298 | if (!tmp_mask) |
| 1299 | return -ENOMEM; |
| 1300 | filter = syscall_table->sc_filter; |
| 1301 | |
| 1302 | for (bit = 0; bit < sc_table.len; bit++) { |
| 1303 | char state; |
| 1304 | |
| 1305 | if (syscall_table->syscall_dispatch) { |
| 1306 | if (!(READ_ONCE(syscall_table->syscall_all_entry) |
| 1307 | || READ_ONCE(syscall_table->syscall_all_exit)) && filter) |
| 1308 | state = test_bit(bit, filter->sc_entry) |
| 1309 | || test_bit(bit, filter->sc_exit); |
| 1310 | else |
| 1311 | state = 1; |
| 1312 | } else { |
| 1313 | state = 0; |
| 1314 | } |
| 1315 | bt_bitfield_write_be(tmp_mask, char, bit, 1, state); |
| 1316 | } |
| 1317 | for (; bit < sc_tables_len; bit++) { |
| 1318 | char state; |
| 1319 | |
| 1320 | if (syscall_table->compat_syscall_dispatch) { |
| 1321 | if (!(READ_ONCE(syscall_table->syscall_all_entry) |
| 1322 | || READ_ONCE(syscall_table->syscall_all_exit)) && filter) |
| 1323 | state = test_bit(bit - sc_table.len, |
| 1324 | filter->sc_compat_entry) |
| 1325 | || test_bit(bit - sc_table.len, |
| 1326 | filter->sc_compat_exit); |
| 1327 | else |
| 1328 | state = 1; |
| 1329 | } else { |
| 1330 | state = 0; |
| 1331 | } |
| 1332 | bt_bitfield_write_be(tmp_mask, char, bit, 1, state); |
| 1333 | } |
| 1334 | if (copy_to_user(usyscall_mask->mask, tmp_mask, bitmask_len)) |
| 1335 | ret = -EFAULT; |
| 1336 | kfree(tmp_mask); |
| 1337 | return ret; |
| 1338 | } |
| 1339 | |
| 1340 | int lttng_abi_syscall_list(void) |
| 1341 | { |
| 1342 | struct file *syscall_list_file; |
| 1343 | int file_fd, ret; |
| 1344 | |
| 1345 | file_fd = lttng_get_unused_fd(); |
| 1346 | if (file_fd < 0) { |
| 1347 | ret = file_fd; |
| 1348 | goto fd_error; |
| 1349 | } |
| 1350 | |
| 1351 | syscall_list_file = anon_inode_getfile("[lttng_syscall_list]", |
| 1352 | <tng_syscall_list_fops, |
| 1353 | NULL, O_RDWR); |
| 1354 | if (IS_ERR(syscall_list_file)) { |
| 1355 | ret = PTR_ERR(syscall_list_file); |
| 1356 | goto file_error; |
| 1357 | } |
| 1358 | ret = lttng_syscall_list_fops.open(NULL, syscall_list_file); |
| 1359 | if (ret < 0) |
| 1360 | goto open_error; |
| 1361 | fd_install(file_fd, syscall_list_file); |
| 1362 | return file_fd; |
| 1363 | |
| 1364 | open_error: |
| 1365 | fput(syscall_list_file); |
| 1366 | file_error: |
| 1367 | put_unused_fd(file_fd); |
| 1368 | fd_error: |
| 1369 | return ret; |
| 1370 | } |