| 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 <wrapper/limits.h> |
| 32 | #include <lttng/events.h> |
| 33 | #include <lttng/events-internal.h> |
| 34 | #include <lttng/utils.h> |
| 35 | |
| 36 | #include "lttng-syscalls.h" |
| 37 | |
| 38 | #ifndef CONFIG_COMPAT |
| 39 | # ifndef is_compat_task |
| 40 | # define is_compat_task() (0) |
| 41 | # endif |
| 42 | #endif |
| 43 | |
| 44 | /* in_compat_syscall appears in kernel 4.6. */ |
| 45 | #ifndef in_compat_syscall |
| 46 | #define in_compat_syscall() is_compat_task() |
| 47 | #endif |
| 48 | |
| 49 | enum sc_type { |
| 50 | SC_TYPE_ENTRY, |
| 51 | SC_TYPE_EXIT, |
| 52 | SC_TYPE_COMPAT_ENTRY, |
| 53 | SC_TYPE_COMPAT_EXIT, |
| 54 | }; |
| 55 | |
| 56 | #define SYSCALL_ENTRY_TOK syscall_entry_ |
| 57 | #define COMPAT_SYSCALL_ENTRY_TOK compat_syscall_entry_ |
| 58 | #define SYSCALL_EXIT_TOK syscall_exit_ |
| 59 | #define COMPAT_SYSCALL_EXIT_TOK compat_syscall_exit_ |
| 60 | |
| 61 | #define SYSCALL_ENTRY_STR __stringify(SYSCALL_ENTRY_TOK) |
| 62 | #define COMPAT_SYSCALL_ENTRY_STR __stringify(COMPAT_SYSCALL_ENTRY_TOK) |
| 63 | #define SYSCALL_EXIT_STR __stringify(SYSCALL_EXIT_TOK) |
| 64 | #define COMPAT_SYSCALL_EXIT_STR __stringify(COMPAT_SYSCALL_EXIT_TOK) |
| 65 | |
| 66 | void syscall_entry_event_probe(void *__data, struct pt_regs *regs, long id); |
| 67 | void syscall_exit_event_probe(void *__data, struct pt_regs *regs, long ret); |
| 68 | |
| 69 | void syscall_entry_event_notifier_probe(void *__data, struct pt_regs *regs, |
| 70 | long id); |
| 71 | void syscall_exit_event_notifier_probe(void *__data, struct pt_regs *regs, |
| 72 | long ret); |
| 73 | |
| 74 | /* |
| 75 | * Forward declarations for old kernels. |
| 76 | */ |
| 77 | struct mmsghdr; |
| 78 | struct rlimit64; |
| 79 | struct oldold_utsname; |
| 80 | struct old_utsname; |
| 81 | struct sel_arg_struct; |
| 82 | struct mmap_arg_struct; |
| 83 | struct file_handle; |
| 84 | struct user_msghdr; |
| 85 | |
| 86 | /* |
| 87 | * Forward declaration for kernels >= 5.6 |
| 88 | */ |
| 89 | struct timex; |
| 90 | struct timeval; |
| 91 | struct itimerval; |
| 92 | struct itimerspec; |
| 93 | |
| 94 | #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,6,0)) |
| 95 | typedef __kernel_old_time_t time_t; |
| 96 | #endif |
| 97 | |
| 98 | #ifdef IA32_NR_syscalls |
| 99 | #define NR_compat_syscalls IA32_NR_syscalls |
| 100 | #else |
| 101 | #define NR_compat_syscalls NR_syscalls |
| 102 | #endif |
| 103 | |
| 104 | /* |
| 105 | * Create LTTng tracepoint probes. |
| 106 | */ |
| 107 | #define LTTNG_PACKAGE_BUILD |
| 108 | #define CREATE_TRACE_POINTS |
| 109 | #define TP_MODULE_NOINIT |
| 110 | #define TRACE_INCLUDE_PATH instrumentation/syscalls/headers |
| 111 | |
| 112 | #define PARAMS(args...) args |
| 113 | |
| 114 | /* Handle unknown syscalls */ |
| 115 | #undef TRACE_SYSTEM |
| 116 | #define TRACE_SYSTEM syscalls_unknown |
| 117 | #include <instrumentation/syscalls/headers/syscalls_unknown.h> |
| 118 | #undef TRACE_SYSTEM |
| 119 | |
| 120 | #undef TP_PROBE_CB |
| 121 | |
| 122 | extern const struct trace_syscall_table sc_table; |
| 123 | extern const struct trace_syscall_table compat_sc_table; |
| 124 | |
| 125 | /* Event syscall exit table */ |
| 126 | extern const struct trace_syscall_table sc_exit_table; |
| 127 | extern const struct trace_syscall_table compat_sc_exit_table; |
| 128 | |
| 129 | |
| 130 | #undef SC_EXIT |
| 131 | |
| 132 | #undef CREATE_SYSCALL_TABLE |
| 133 | |
| 134 | struct lttng_syscall_filter { |
| 135 | DECLARE_BITMAP(sc_entry, NR_syscalls); |
| 136 | DECLARE_BITMAP(sc_exit, NR_syscalls); |
| 137 | DECLARE_BITMAP(sc_compat_entry, NR_compat_syscalls); |
| 138 | DECLARE_BITMAP(sc_compat_exit, NR_compat_syscalls); |
| 139 | |
| 140 | /* |
| 141 | * Reference counters keeping track of number of events enabled |
| 142 | * for each bit. |
| 143 | */ |
| 144 | u32 sc_entry_refcount_map[NR_syscalls]; |
| 145 | u32 sc_exit_refcount_map[NR_syscalls]; |
| 146 | u32 sc_compat_entry_refcount_map[NR_compat_syscalls]; |
| 147 | u32 sc_compat_exit_refcount_map[NR_compat_syscalls]; |
| 148 | }; |
| 149 | |
| 150 | static void syscall_entry_event_unknown(struct hlist_head *unknown_action_list_head, |
| 151 | struct pt_regs *regs, long id) |
| 152 | { |
| 153 | unsigned long args[LTTNG_SYSCALL_NR_ARGS]; |
| 154 | struct lttng_kernel_event_common_private *event_priv; |
| 155 | |
| 156 | lttng_syscall_get_arguments(current, regs, args); |
| 157 | lttng_hlist_for_each_entry_rcu(event_priv, unknown_action_list_head, u.syscall.node) { |
| 158 | if (unlikely(in_compat_syscall())) |
| 159 | __event_probe__compat_syscall_entry_unknown(event_priv->pub, id, args); |
| 160 | else |
| 161 | __event_probe__syscall_entry_unknown(event_priv->pub, id, args); |
| 162 | } |
| 163 | } |
| 164 | |
| 165 | static __always_inline |
| 166 | void syscall_entry_event_call_func(struct hlist_head *action_list, |
| 167 | void *func, unsigned int nrargs, |
| 168 | struct pt_regs *regs) |
| 169 | { |
| 170 | struct lttng_kernel_event_common_private *event_priv; |
| 171 | |
| 172 | switch (nrargs) { |
| 173 | case 0: |
| 174 | { |
| 175 | void (*fptr)(void *__data) = func; |
| 176 | |
| 177 | lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node) |
| 178 | fptr(event_priv->pub); |
| 179 | break; |
| 180 | } |
| 181 | case 1: |
| 182 | { |
| 183 | void (*fptr)(void *__data, unsigned long arg0) = func; |
| 184 | unsigned long args[LTTNG_SYSCALL_NR_ARGS]; |
| 185 | |
| 186 | lttng_syscall_get_arguments(current, regs, args); |
| 187 | lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node) |
| 188 | fptr(event_priv->pub, args[0]); |
| 189 | break; |
| 190 | } |
| 191 | case 2: |
| 192 | { |
| 193 | void (*fptr)(void *__data, |
| 194 | unsigned long arg0, |
| 195 | unsigned long arg1) = func; |
| 196 | unsigned long args[LTTNG_SYSCALL_NR_ARGS]; |
| 197 | |
| 198 | lttng_syscall_get_arguments(current, regs, args); |
| 199 | lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node) |
| 200 | fptr(event_priv->pub, args[0], args[1]); |
| 201 | break; |
| 202 | } |
| 203 | case 3: |
| 204 | { |
| 205 | void (*fptr)(void *__data, |
| 206 | unsigned long arg0, |
| 207 | unsigned long arg1, |
| 208 | unsigned long arg2) = func; |
| 209 | unsigned long args[LTTNG_SYSCALL_NR_ARGS]; |
| 210 | |
| 211 | lttng_syscall_get_arguments(current, regs, args); |
| 212 | lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node) |
| 213 | fptr(event_priv->pub, args[0], args[1], args[2]); |
| 214 | break; |
| 215 | } |
| 216 | case 4: |
| 217 | { |
| 218 | void (*fptr)(void *__data, |
| 219 | unsigned long arg0, |
| 220 | unsigned long arg1, |
| 221 | unsigned long arg2, |
| 222 | unsigned long arg3) = 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]); |
| 228 | break; |
| 229 | } |
| 230 | case 5: |
| 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) = func; |
| 238 | unsigned long args[LTTNG_SYSCALL_NR_ARGS]; |
| 239 | |
| 240 | lttng_syscall_get_arguments(current, regs, args); |
| 241 | lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node) |
| 242 | fptr(event_priv->pub, args[0], args[1], args[2], args[3], args[4]); |
| 243 | break; |
| 244 | } |
| 245 | case 6: |
| 246 | { |
| 247 | void (*fptr)(void *__data, |
| 248 | unsigned long arg0, |
| 249 | unsigned long arg1, |
| 250 | unsigned long arg2, |
| 251 | unsigned long arg3, |
| 252 | unsigned long arg4, |
| 253 | unsigned long arg5) = func; |
| 254 | unsigned long args[LTTNG_SYSCALL_NR_ARGS]; |
| 255 | |
| 256 | lttng_syscall_get_arguments(current, regs, args); |
| 257 | lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node) |
| 258 | fptr(event_priv->pub, args[0], args[1], args[2], |
| 259 | args[3], args[4], args[5]); |
| 260 | break; |
| 261 | } |
| 262 | default: |
| 263 | break; |
| 264 | } |
| 265 | } |
| 266 | |
| 267 | void syscall_entry_event_probe(void *__data, struct pt_regs *regs, long id) |
| 268 | { |
| 269 | struct lttng_kernel_channel_buffer *chan = __data; |
| 270 | struct hlist_head *action_list, *unknown_action_list; |
| 271 | const struct trace_syscall_entry *table, *entry; |
| 272 | size_t table_len; |
| 273 | |
| 274 | if (unlikely(in_compat_syscall())) { |
| 275 | struct lttng_syscall_filter *filter = chan->priv->parent.sc_filter; |
| 276 | |
| 277 | if (id < 0 || id >= NR_compat_syscalls |
| 278 | || (!READ_ONCE(chan->priv->parent.syscall_all_entry) && !test_bit(id, filter->sc_compat_entry))) { |
| 279 | /* System call filtered out. */ |
| 280 | return; |
| 281 | } |
| 282 | table = compat_sc_table.table; |
| 283 | table_len = compat_sc_table.len; |
| 284 | unknown_action_list = &chan->priv->parent.sc_compat_unknown; |
| 285 | } else { |
| 286 | struct lttng_syscall_filter *filter = chan->priv->parent.sc_filter; |
| 287 | |
| 288 | if (id < 0 || id >= NR_syscalls |
| 289 | || (!READ_ONCE(chan->priv->parent.syscall_all_entry) && !test_bit(id, filter->sc_entry))) { |
| 290 | /* System call filtered out. */ |
| 291 | return; |
| 292 | } |
| 293 | table = sc_table.table; |
| 294 | table_len = sc_table.len; |
| 295 | unknown_action_list = &chan->priv->parent.sc_unknown; |
| 296 | } |
| 297 | if (unlikely(id < 0 || id >= table_len)) { |
| 298 | syscall_entry_event_unknown(unknown_action_list, regs, id); |
| 299 | return; |
| 300 | } |
| 301 | |
| 302 | entry = &table[id]; |
| 303 | if (!entry->event_func) { |
| 304 | syscall_entry_event_unknown(unknown_action_list, regs, id); |
| 305 | return; |
| 306 | } |
| 307 | |
| 308 | if (unlikely(in_compat_syscall())) { |
| 309 | action_list = &chan->priv->parent.compat_sc_table[id]; |
| 310 | } else { |
| 311 | action_list = &chan->priv->parent.sc_table[id]; |
| 312 | } |
| 313 | if (unlikely(hlist_empty(action_list))) |
| 314 | return; |
| 315 | |
| 316 | syscall_entry_event_call_func(action_list, entry->event_func, entry->nrargs, regs); |
| 317 | } |
| 318 | |
| 319 | void syscall_entry_event_notifier_probe(void *__data, struct pt_regs *regs, |
| 320 | long id) |
| 321 | { |
| 322 | struct lttng_event_notifier_group *group = __data; |
| 323 | const struct trace_syscall_entry *table, *entry; |
| 324 | struct hlist_head *dispatch_list, *unknown_dispatch_list; |
| 325 | size_t table_len; |
| 326 | |
| 327 | if (unlikely(in_compat_syscall())) { |
| 328 | struct lttng_syscall_filter *filter = group->sc_filter; |
| 329 | |
| 330 | if (id < 0 || id >= NR_compat_syscalls |
| 331 | || (!READ_ONCE(group->syscall_all_entry) && |
| 332 | !test_bit(id, filter->sc_compat_entry))) { |
| 333 | /* System call filtered out. */ |
| 334 | return; |
| 335 | } |
| 336 | table = compat_sc_table.table; |
| 337 | table_len = compat_sc_table.len; |
| 338 | unknown_dispatch_list = &group->event_notifier_compat_unknown_syscall_dispatch; |
| 339 | } else { |
| 340 | struct lttng_syscall_filter *filter = group->sc_filter; |
| 341 | |
| 342 | if (id < 0 || id >= NR_syscalls |
| 343 | || (!READ_ONCE(group->syscall_all_entry) && |
| 344 | !test_bit(id, filter->sc_entry))) { |
| 345 | /* System call filtered out. */ |
| 346 | return; |
| 347 | } |
| 348 | table = sc_table.table; |
| 349 | table_len = sc_table.len; |
| 350 | unknown_dispatch_list = &group->event_notifier_unknown_syscall_dispatch; |
| 351 | } |
| 352 | /* Check if the syscall id is out of bound. */ |
| 353 | if (unlikely(id < 0 || id >= table_len)) { |
| 354 | syscall_entry_event_unknown(unknown_dispatch_list, |
| 355 | regs, id); |
| 356 | return; |
| 357 | } |
| 358 | |
| 359 | entry = &table[id]; |
| 360 | if (!entry->event_func) { |
| 361 | syscall_entry_event_unknown(unknown_dispatch_list, |
| 362 | regs, id); |
| 363 | return; |
| 364 | } |
| 365 | |
| 366 | if (unlikely(in_compat_syscall())) { |
| 367 | dispatch_list = &group->event_notifier_compat_syscall_dispatch[id]; |
| 368 | } else { |
| 369 | dispatch_list = &group->event_notifier_syscall_dispatch[id]; |
| 370 | } |
| 371 | if (unlikely(hlist_empty(dispatch_list))) |
| 372 | return; |
| 373 | |
| 374 | syscall_entry_event_call_func(dispatch_list, |
| 375 | entry->event_func, entry->nrargs, regs); |
| 376 | } |
| 377 | |
| 378 | static void syscall_exit_event_unknown(struct hlist_head *unknown_action_list_head, |
| 379 | struct pt_regs *regs, long id, long ret) |
| 380 | { |
| 381 | unsigned long args[LTTNG_SYSCALL_NR_ARGS]; |
| 382 | struct lttng_kernel_event_common_private *event_priv; |
| 383 | |
| 384 | lttng_syscall_get_arguments(current, regs, args); |
| 385 | lttng_hlist_for_each_entry_rcu(event_priv, unknown_action_list_head, u.syscall.node) { |
| 386 | if (unlikely(in_compat_syscall())) |
| 387 | __event_probe__compat_syscall_exit_unknown(event_priv->pub, id, ret, |
| 388 | args); |
| 389 | else |
| 390 | __event_probe__syscall_exit_unknown(event_priv->pub, id, ret, args); |
| 391 | } |
| 392 | } |
| 393 | |
| 394 | static __always_inline |
| 395 | void syscall_exit_event_call_func(struct hlist_head *action_list, |
| 396 | void *func, unsigned int nrargs, |
| 397 | struct pt_regs *regs, long ret) |
| 398 | { |
| 399 | struct lttng_kernel_event_common_private *event_priv; |
| 400 | |
| 401 | switch (nrargs) { |
| 402 | case 0: |
| 403 | { |
| 404 | void (*fptr)(void *__data, long ret) = func; |
| 405 | |
| 406 | lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node) |
| 407 | fptr(event_priv->pub, ret); |
| 408 | break; |
| 409 | } |
| 410 | case 1: |
| 411 | { |
| 412 | void (*fptr)(void *__data, |
| 413 | long ret, |
| 414 | unsigned long arg0) = func; |
| 415 | unsigned long args[LTTNG_SYSCALL_NR_ARGS]; |
| 416 | |
| 417 | lttng_syscall_get_arguments(current, regs, args); |
| 418 | lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node) |
| 419 | fptr(event_priv->pub, ret, args[0]); |
| 420 | break; |
| 421 | } |
| 422 | case 2: |
| 423 | { |
| 424 | void (*fptr)(void *__data, |
| 425 | long ret, |
| 426 | unsigned long arg0, |
| 427 | unsigned long arg1) = func; |
| 428 | unsigned long args[LTTNG_SYSCALL_NR_ARGS]; |
| 429 | |
| 430 | lttng_syscall_get_arguments(current, regs, args); |
| 431 | lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node) |
| 432 | fptr(event_priv->pub, ret, args[0], args[1]); |
| 433 | break; |
| 434 | } |
| 435 | case 3: |
| 436 | { |
| 437 | void (*fptr)(void *__data, |
| 438 | long ret, |
| 439 | unsigned long arg0, |
| 440 | unsigned long arg1, |
| 441 | unsigned long arg2) = func; |
| 442 | unsigned long args[LTTNG_SYSCALL_NR_ARGS]; |
| 443 | |
| 444 | lttng_syscall_get_arguments(current, regs, args); |
| 445 | lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node) |
| 446 | fptr(event_priv->pub, ret, args[0], args[1], args[2]); |
| 447 | break; |
| 448 | } |
| 449 | case 4: |
| 450 | { |
| 451 | void (*fptr)(void *__data, |
| 452 | long ret, |
| 453 | unsigned long arg0, |
| 454 | unsigned long arg1, |
| 455 | unsigned long arg2, |
| 456 | unsigned long arg3) = func; |
| 457 | unsigned long args[LTTNG_SYSCALL_NR_ARGS]; |
| 458 | |
| 459 | lttng_syscall_get_arguments(current, regs, args); |
| 460 | lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node) |
| 461 | fptr(event_priv->pub, ret, args[0], args[1], args[2], args[3]); |
| 462 | break; |
| 463 | } |
| 464 | case 5: |
| 465 | { |
| 466 | void (*fptr)(void *__data, |
| 467 | long ret, |
| 468 | unsigned long arg0, |
| 469 | unsigned long arg1, |
| 470 | unsigned long arg2, |
| 471 | unsigned long arg3, |
| 472 | unsigned long arg4) = func; |
| 473 | unsigned long args[LTTNG_SYSCALL_NR_ARGS]; |
| 474 | |
| 475 | lttng_syscall_get_arguments(current, regs, args); |
| 476 | lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node) |
| 477 | fptr(event_priv->pub, ret, args[0], args[1], args[2], args[3], args[4]); |
| 478 | break; |
| 479 | } |
| 480 | case 6: |
| 481 | { |
| 482 | void (*fptr)(void *__data, |
| 483 | long ret, |
| 484 | unsigned long arg0, |
| 485 | unsigned long arg1, |
| 486 | unsigned long arg2, |
| 487 | unsigned long arg3, |
| 488 | unsigned long arg4, |
| 489 | unsigned long arg5) = func; |
| 490 | unsigned long args[LTTNG_SYSCALL_NR_ARGS]; |
| 491 | |
| 492 | lttng_syscall_get_arguments(current, regs, args); |
| 493 | lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node) |
| 494 | fptr(event_priv->pub, ret, args[0], args[1], args[2], |
| 495 | args[3], args[4], args[5]); |
| 496 | break; |
| 497 | } |
| 498 | default: |
| 499 | break; |
| 500 | } |
| 501 | } |
| 502 | |
| 503 | void syscall_exit_event_probe(void *__data, struct pt_regs *regs, long ret) |
| 504 | { |
| 505 | struct lttng_kernel_channel_buffer *chan = __data; |
| 506 | struct hlist_head *action_list, *unknown_action_list; |
| 507 | const struct trace_syscall_entry *table, *entry; |
| 508 | size_t table_len; |
| 509 | long id; |
| 510 | |
| 511 | id = syscall_get_nr(current, regs); |
| 512 | |
| 513 | if (unlikely(in_compat_syscall())) { |
| 514 | struct lttng_syscall_filter *filter = chan->priv->parent.sc_filter; |
| 515 | |
| 516 | if (id < 0 || id >= NR_compat_syscalls |
| 517 | || (!READ_ONCE(chan->priv->parent.syscall_all_exit) && !test_bit(id, filter->sc_compat_exit))) { |
| 518 | /* System call filtered out. */ |
| 519 | return; |
| 520 | } |
| 521 | table = compat_sc_exit_table.table; |
| 522 | table_len = compat_sc_exit_table.len; |
| 523 | unknown_action_list = &chan->priv->parent.compat_sc_exit_unknown; |
| 524 | } else { |
| 525 | struct lttng_syscall_filter *filter = chan->priv->parent.sc_filter; |
| 526 | |
| 527 | if (id < 0 || id >= NR_syscalls |
| 528 | || (!READ_ONCE(chan->priv->parent.syscall_all_exit) && !test_bit(id, filter->sc_exit))) { |
| 529 | /* System call filtered out. */ |
| 530 | return; |
| 531 | } |
| 532 | table = sc_exit_table.table; |
| 533 | table_len = sc_exit_table.len; |
| 534 | unknown_action_list = &chan->priv->parent.sc_exit_unknown; |
| 535 | } |
| 536 | if (unlikely(id < 0 || id >= table_len)) { |
| 537 | syscall_exit_event_unknown(unknown_action_list, regs, id, ret); |
| 538 | return; |
| 539 | } |
| 540 | |
| 541 | entry = &table[id]; |
| 542 | if (!entry->event_func) { |
| 543 | syscall_exit_event_unknown(unknown_action_list, regs, id, ret); |
| 544 | return; |
| 545 | } |
| 546 | |
| 547 | if (unlikely(in_compat_syscall())) { |
| 548 | action_list = &chan->priv->parent.compat_sc_exit_table[id]; |
| 549 | } else { |
| 550 | action_list = &chan->priv->parent.sc_exit_table[id]; |
| 551 | } |
| 552 | if (unlikely(hlist_empty(action_list))) |
| 553 | return; |
| 554 | |
| 555 | syscall_exit_event_call_func(action_list, entry->event_func, entry->nrargs, |
| 556 | regs, ret); |
| 557 | } |
| 558 | |
| 559 | void syscall_exit_event_notifier_probe(void *__data, struct pt_regs *regs, |
| 560 | long ret) |
| 561 | { |
| 562 | struct lttng_event_notifier_group *group = __data; |
| 563 | const struct trace_syscall_entry *table, *entry; |
| 564 | struct hlist_head *dispatch_list, *unknown_dispatch_list; |
| 565 | size_t table_len; |
| 566 | long id; |
| 567 | |
| 568 | id = syscall_get_nr(current, regs); |
| 569 | |
| 570 | if (unlikely(in_compat_syscall())) { |
| 571 | struct lttng_syscall_filter *filter = group->sc_filter; |
| 572 | |
| 573 | if (id < 0 || id >= NR_compat_syscalls |
| 574 | || (!READ_ONCE(group->syscall_all_exit) && |
| 575 | !test_bit(id, filter->sc_compat_exit))) { |
| 576 | /* System call filtered out. */ |
| 577 | return; |
| 578 | } |
| 579 | table = compat_sc_exit_table.table; |
| 580 | table_len = compat_sc_exit_table.len; |
| 581 | unknown_dispatch_list = &group->event_notifier_exit_compat_unknown_syscall_dispatch; |
| 582 | } else { |
| 583 | struct lttng_syscall_filter *filter = group->sc_filter; |
| 584 | |
| 585 | if (id < 0 || id >= NR_syscalls |
| 586 | || (!READ_ONCE(group->syscall_all_exit) && |
| 587 | !test_bit(id, filter->sc_exit))) { |
| 588 | /* System call filtered out. */ |
| 589 | return; |
| 590 | } |
| 591 | table = sc_exit_table.table; |
| 592 | table_len = sc_exit_table.len; |
| 593 | unknown_dispatch_list = &group->event_notifier_exit_unknown_syscall_dispatch; |
| 594 | } |
| 595 | /* Check if the syscall id is out of bound. */ |
| 596 | if (unlikely(id < 0 || id >= table_len)) { |
| 597 | syscall_exit_event_unknown(unknown_dispatch_list, |
| 598 | regs, id, ret); |
| 599 | return; |
| 600 | } |
| 601 | |
| 602 | entry = &table[id]; |
| 603 | if (!entry->event_func) { |
| 604 | syscall_entry_event_unknown(unknown_dispatch_list, |
| 605 | regs, id); |
| 606 | return; |
| 607 | } |
| 608 | |
| 609 | if (unlikely(in_compat_syscall())) { |
| 610 | dispatch_list = &group->event_notifier_exit_compat_syscall_dispatch[id]; |
| 611 | } else { |
| 612 | dispatch_list = &group->event_notifier_exit_syscall_dispatch[id]; |
| 613 | } |
| 614 | if (unlikely(hlist_empty(dispatch_list))) |
| 615 | return; |
| 616 | |
| 617 | syscall_exit_event_call_func(dispatch_list, |
| 618 | entry->event_func, entry->nrargs, regs, ret); |
| 619 | } |
| 620 | /* |
| 621 | * noinline to diminish caller stack size. |
| 622 | * Should be called with sessions lock held. |
| 623 | */ |
| 624 | static |
| 625 | int lttng_create_syscall_event_if_missing(const struct trace_syscall_entry *table, size_t table_len, |
| 626 | struct hlist_head *chan_table, struct lttng_event_enabler *event_enabler, |
| 627 | enum sc_type type) |
| 628 | { |
| 629 | struct lttng_kernel_channel_buffer *chan = event_enabler->chan; |
| 630 | struct lttng_kernel_session *session = chan->parent.session; |
| 631 | unsigned int i; |
| 632 | |
| 633 | /* Allocate events for each syscall matching enabler, insert into table */ |
| 634 | for (i = 0; i < table_len; i++) { |
| 635 | const struct lttng_kernel_event_desc *desc = table[i].desc; |
| 636 | struct lttng_kernel_abi_event ev; |
| 637 | struct lttng_kernel_event_recorder_private *event_recorder_priv; |
| 638 | struct lttng_kernel_event_recorder *event_recorder; |
| 639 | struct hlist_head *head; |
| 640 | bool found = false; |
| 641 | |
| 642 | if (!desc) { |
| 643 | /* Unknown syscall */ |
| 644 | continue; |
| 645 | } |
| 646 | if (lttng_desc_match_enabler(desc, |
| 647 | lttng_event_enabler_as_enabler(event_enabler)) <= 0) |
| 648 | continue; |
| 649 | /* |
| 650 | * Check if already created. |
| 651 | */ |
| 652 | head = utils_borrow_hash_table_bucket( |
| 653 | session->priv->events_ht.table, LTTNG_EVENT_HT_SIZE, |
| 654 | desc->event_name); |
| 655 | lttng_hlist_for_each_entry(event_recorder_priv, head, hlist) { |
| 656 | if (event_recorder_priv->parent.desc == desc |
| 657 | && event_recorder_priv->pub->chan == event_enabler->chan) |
| 658 | found = true; |
| 659 | } |
| 660 | if (found) |
| 661 | continue; |
| 662 | |
| 663 | /* We need to create an event for this syscall/enabler. */ |
| 664 | memset(&ev, 0, sizeof(ev)); |
| 665 | switch (type) { |
| 666 | case SC_TYPE_ENTRY: |
| 667 | ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY; |
| 668 | ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE; |
| 669 | break; |
| 670 | case SC_TYPE_EXIT: |
| 671 | ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT; |
| 672 | ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE; |
| 673 | break; |
| 674 | case SC_TYPE_COMPAT_ENTRY: |
| 675 | ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY; |
| 676 | ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT; |
| 677 | break; |
| 678 | case SC_TYPE_COMPAT_EXIT: |
| 679 | ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT; |
| 680 | ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT; |
| 681 | break; |
| 682 | } |
| 683 | strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1); |
| 684 | ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0'; |
| 685 | ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL; |
| 686 | event_recorder = _lttng_kernel_event_recorder_create(chan, &ev, desc, ev.instrumentation); |
| 687 | WARN_ON_ONCE(!event_recorder); |
| 688 | if (IS_ERR(event_recorder)) { |
| 689 | /* |
| 690 | * If something goes wrong in event registration |
| 691 | * after the first one, we have no choice but to |
| 692 | * leave the previous events in there, until |
| 693 | * deleted by session teardown. |
| 694 | */ |
| 695 | return PTR_ERR(event_recorder); |
| 696 | } |
| 697 | hlist_add_head(&event_recorder->priv->parent.u.syscall.node, &chan_table[i]); |
| 698 | } |
| 699 | return 0; |
| 700 | } |
| 701 | |
| 702 | /* |
| 703 | * Should be called with sessions lock held. |
| 704 | */ |
| 705 | int lttng_syscalls_register_event(struct lttng_event_enabler *event_enabler) |
| 706 | { |
| 707 | struct lttng_kernel_channel_buffer *chan = event_enabler->chan; |
| 708 | struct lttng_kernel_abi_event ev; |
| 709 | int ret; |
| 710 | |
| 711 | wrapper_vmalloc_sync_mappings(); |
| 712 | |
| 713 | if (!chan->priv->parent.sc_table) { |
| 714 | /* create syscall table mapping syscall to events */ |
| 715 | chan->priv->parent.sc_table = kzalloc(sizeof(struct lttng_kernel_event_recorder *) |
| 716 | * sc_table.len, GFP_KERNEL); |
| 717 | if (!chan->priv->parent.sc_table) |
| 718 | return -ENOMEM; |
| 719 | } |
| 720 | if (!chan->priv->parent.sc_exit_table) { |
| 721 | /* create syscall table mapping syscall to events */ |
| 722 | chan->priv->parent.sc_exit_table = kzalloc(sizeof(struct lttng_kernel_event_recorder *) |
| 723 | * sc_exit_table.len, GFP_KERNEL); |
| 724 | if (!chan->priv->parent.sc_exit_table) |
| 725 | return -ENOMEM; |
| 726 | } |
| 727 | |
| 728 | |
| 729 | #ifdef CONFIG_COMPAT |
| 730 | if (!chan->priv->parent.compat_sc_table) { |
| 731 | /* create syscall table mapping compat syscall to events */ |
| 732 | chan->priv->parent.compat_sc_table = kzalloc(sizeof(struct lttng_kernel_event_recorder *) |
| 733 | * compat_sc_table.len, GFP_KERNEL); |
| 734 | if (!chan->priv->parent.compat_sc_table) |
| 735 | return -ENOMEM; |
| 736 | } |
| 737 | |
| 738 | if (!chan->priv->parent.compat_sc_exit_table) { |
| 739 | /* create syscall table mapping compat syscall to events */ |
| 740 | chan->priv->parent.compat_sc_exit_table = kzalloc(sizeof(struct lttng_kernel_event_recorder *) |
| 741 | * compat_sc_exit_table.len, GFP_KERNEL); |
| 742 | if (!chan->priv->parent.compat_sc_exit_table) |
| 743 | return -ENOMEM; |
| 744 | } |
| 745 | #endif |
| 746 | if (hlist_empty(&chan->priv->parent.sc_unknown)) { |
| 747 | const struct lttng_kernel_event_desc *desc = |
| 748 | &__event_desc___syscall_entry_unknown; |
| 749 | struct lttng_kernel_event_recorder *event_recorder; |
| 750 | |
| 751 | memset(&ev, 0, sizeof(ev)); |
| 752 | strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN); |
| 753 | ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0'; |
| 754 | ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL; |
| 755 | ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY; |
| 756 | ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE; |
| 757 | event_recorder = _lttng_kernel_event_recorder_create(chan, &ev, desc, |
| 758 | ev.instrumentation); |
| 759 | WARN_ON_ONCE(!event_recorder); |
| 760 | if (IS_ERR(event_recorder)) { |
| 761 | return PTR_ERR(event_recorder); |
| 762 | } |
| 763 | hlist_add_head(&event_recorder->priv->parent.u.syscall.node, &chan->priv->parent.sc_unknown); |
| 764 | } |
| 765 | |
| 766 | if (hlist_empty(&chan->priv->parent.sc_compat_unknown)) { |
| 767 | const struct lttng_kernel_event_desc *desc = |
| 768 | &__event_desc___compat_syscall_entry_unknown; |
| 769 | struct lttng_kernel_event_recorder *event_recorder; |
| 770 | |
| 771 | memset(&ev, 0, sizeof(ev)); |
| 772 | strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN); |
| 773 | ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0'; |
| 774 | ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL; |
| 775 | ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY; |
| 776 | ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT; |
| 777 | event_recorder = _lttng_kernel_event_recorder_create(chan, &ev, desc, |
| 778 | ev.instrumentation); |
| 779 | WARN_ON_ONCE(!event_recorder); |
| 780 | if (IS_ERR(event_recorder)) { |
| 781 | return PTR_ERR(event_recorder); |
| 782 | } |
| 783 | hlist_add_head(&event_recorder->priv->parent.u.syscall.node, &chan->priv->parent.sc_compat_unknown); |
| 784 | } |
| 785 | |
| 786 | if (hlist_empty(&chan->priv->parent.compat_sc_exit_unknown)) { |
| 787 | const struct lttng_kernel_event_desc *desc = |
| 788 | &__event_desc___compat_syscall_exit_unknown; |
| 789 | struct lttng_kernel_event_recorder *event_recorder; |
| 790 | |
| 791 | memset(&ev, 0, sizeof(ev)); |
| 792 | strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN); |
| 793 | ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0'; |
| 794 | ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL; |
| 795 | ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT; |
| 796 | ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT; |
| 797 | event_recorder = _lttng_kernel_event_recorder_create(chan, &ev, desc, |
| 798 | ev.instrumentation); |
| 799 | WARN_ON_ONCE(!event_recorder); |
| 800 | if (IS_ERR(event_recorder)) { |
| 801 | return PTR_ERR(event_recorder); |
| 802 | } |
| 803 | hlist_add_head(&event_recorder->priv->parent.u.syscall.node, &chan->priv->parent.compat_sc_exit_unknown); |
| 804 | } |
| 805 | |
| 806 | if (hlist_empty(&chan->priv->parent.sc_exit_unknown)) { |
| 807 | const struct lttng_kernel_event_desc *desc = |
| 808 | &__event_desc___syscall_exit_unknown; |
| 809 | struct lttng_kernel_event_recorder *event_recorder; |
| 810 | |
| 811 | memset(&ev, 0, sizeof(ev)); |
| 812 | strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN); |
| 813 | ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0'; |
| 814 | ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL; |
| 815 | ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT; |
| 816 | ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE; |
| 817 | event_recorder = _lttng_kernel_event_recorder_create(chan, &ev, desc, |
| 818 | ev.instrumentation); |
| 819 | WARN_ON_ONCE(!event_recorder); |
| 820 | if (IS_ERR(event_recorder)) { |
| 821 | return PTR_ERR(event_recorder); |
| 822 | } |
| 823 | hlist_add_head(&event_recorder->priv->parent.u.syscall.node, &chan->priv->parent.sc_exit_unknown); |
| 824 | } |
| 825 | |
| 826 | ret = lttng_create_syscall_event_if_missing(sc_table.table, sc_table.len, |
| 827 | chan->priv->parent.sc_table, event_enabler, SC_TYPE_ENTRY); |
| 828 | if (ret) |
| 829 | return ret; |
| 830 | ret = lttng_create_syscall_event_if_missing(sc_exit_table.table, sc_exit_table.len, |
| 831 | chan->priv->parent.sc_exit_table, event_enabler, SC_TYPE_EXIT); |
| 832 | if (ret) |
| 833 | return ret; |
| 834 | |
| 835 | #ifdef CONFIG_COMPAT |
| 836 | ret = lttng_create_syscall_event_if_missing(compat_sc_table.table, compat_sc_table.len, |
| 837 | chan->priv->parent.compat_sc_table, event_enabler, SC_TYPE_COMPAT_ENTRY); |
| 838 | if (ret) |
| 839 | return ret; |
| 840 | ret = lttng_create_syscall_event_if_missing(compat_sc_exit_table.table, compat_sc_exit_table.len, |
| 841 | chan->priv->parent.compat_sc_exit_table, event_enabler, SC_TYPE_COMPAT_EXIT); |
| 842 | if (ret) |
| 843 | return ret; |
| 844 | #endif |
| 845 | |
| 846 | if (!chan->priv->parent.sc_filter) { |
| 847 | chan->priv->parent.sc_filter = kzalloc(sizeof(struct lttng_syscall_filter), |
| 848 | GFP_KERNEL); |
| 849 | if (!chan->priv->parent.sc_filter) |
| 850 | return -ENOMEM; |
| 851 | } |
| 852 | |
| 853 | if (!chan->priv->parent.sys_enter_registered) { |
| 854 | ret = lttng_wrapper_tracepoint_probe_register("sys_enter", |
| 855 | (void *) syscall_entry_event_probe, chan); |
| 856 | if (ret) |
| 857 | return ret; |
| 858 | chan->priv->parent.sys_enter_registered = 1; |
| 859 | } |
| 860 | /* |
| 861 | * We change the name of sys_exit tracepoint due to namespace |
| 862 | * conflict with sys_exit syscall entry. |
| 863 | */ |
| 864 | if (!chan->priv->parent.sys_exit_registered) { |
| 865 | ret = lttng_wrapper_tracepoint_probe_register("sys_exit", |
| 866 | (void *) syscall_exit_event_probe, chan); |
| 867 | if (ret) { |
| 868 | WARN_ON_ONCE(lttng_wrapper_tracepoint_probe_unregister("sys_enter", |
| 869 | (void *) syscall_entry_event_probe, chan)); |
| 870 | return ret; |
| 871 | } |
| 872 | chan->priv->parent.sys_exit_registered = 1; |
| 873 | } |
| 874 | return ret; |
| 875 | } |
| 876 | |
| 877 | /* |
| 878 | * Should be called with sessions lock held. |
| 879 | */ |
| 880 | int lttng_syscalls_register_event_notifier( |
| 881 | struct lttng_event_notifier_enabler *event_notifier_enabler) |
| 882 | { |
| 883 | struct lttng_event_notifier_group *group = event_notifier_enabler->group; |
| 884 | unsigned int i; |
| 885 | int ret = 0; |
| 886 | |
| 887 | wrapper_vmalloc_sync_mappings(); |
| 888 | |
| 889 | if (!group->event_notifier_syscall_dispatch) { |
| 890 | group->event_notifier_syscall_dispatch = |
| 891 | kzalloc(sizeof(struct hlist_head) * sc_table.len, |
| 892 | GFP_KERNEL); |
| 893 | if (!group->event_notifier_syscall_dispatch) |
| 894 | return -ENOMEM; |
| 895 | |
| 896 | /* Initialize all list_head */ |
| 897 | for (i = 0; i < sc_table.len; i++) |
| 898 | INIT_HLIST_HEAD(&group->event_notifier_syscall_dispatch[i]); |
| 899 | |
| 900 | /* Init the unknown syscall notifier list. */ |
| 901 | INIT_HLIST_HEAD(&group->event_notifier_unknown_syscall_dispatch); |
| 902 | } |
| 903 | |
| 904 | if (!group->event_notifier_exit_syscall_dispatch) { |
| 905 | group->event_notifier_exit_syscall_dispatch = |
| 906 | kzalloc(sizeof(struct hlist_head) * sc_table.len, |
| 907 | GFP_KERNEL); |
| 908 | if (!group->event_notifier_exit_syscall_dispatch) |
| 909 | return -ENOMEM; |
| 910 | |
| 911 | /* Initialize all list_head */ |
| 912 | for (i = 0; i < sc_table.len; i++) |
| 913 | INIT_HLIST_HEAD(&group->event_notifier_exit_syscall_dispatch[i]); |
| 914 | |
| 915 | /* Init the unknown exit syscall notifier list. */ |
| 916 | INIT_HLIST_HEAD(&group->event_notifier_exit_unknown_syscall_dispatch); |
| 917 | } |
| 918 | |
| 919 | #ifdef CONFIG_COMPAT |
| 920 | if (!group->event_notifier_compat_syscall_dispatch) { |
| 921 | group->event_notifier_compat_syscall_dispatch = |
| 922 | kzalloc(sizeof(struct hlist_head) * compat_sc_table.len, |
| 923 | GFP_KERNEL); |
| 924 | if (!group->event_notifier_syscall_dispatch) |
| 925 | return -ENOMEM; |
| 926 | |
| 927 | /* Initialize all list_head */ |
| 928 | for (i = 0; i < compat_sc_table.len; i++) |
| 929 | INIT_HLIST_HEAD(&group->event_notifier_compat_syscall_dispatch[i]); |
| 930 | |
| 931 | /* Init the unknown syscall notifier list. */ |
| 932 | INIT_HLIST_HEAD(&group->event_notifier_compat_unknown_syscall_dispatch); |
| 933 | } |
| 934 | |
| 935 | if (!group->event_notifier_exit_compat_syscall_dispatch) { |
| 936 | group->event_notifier_exit_compat_syscall_dispatch = |
| 937 | kzalloc(sizeof(struct hlist_head) * compat_sc_exit_table.len, |
| 938 | GFP_KERNEL); |
| 939 | if (!group->event_notifier_exit_syscall_dispatch) |
| 940 | return -ENOMEM; |
| 941 | |
| 942 | /* Initialize all list_head */ |
| 943 | for (i = 0; i < compat_sc_exit_table.len; i++) |
| 944 | INIT_HLIST_HEAD(&group->event_notifier_exit_compat_syscall_dispatch[i]); |
| 945 | |
| 946 | /* Init the unknown exit syscall notifier list. */ |
| 947 | INIT_HLIST_HEAD(&group->event_notifier_exit_compat_unknown_syscall_dispatch); |
| 948 | } |
| 949 | #endif |
| 950 | |
| 951 | if (!group->sc_filter) { |
| 952 | group->sc_filter = kzalloc(sizeof(struct lttng_syscall_filter), |
| 953 | GFP_KERNEL); |
| 954 | if (!group->sc_filter) |
| 955 | return -ENOMEM; |
| 956 | } |
| 957 | |
| 958 | if (!group->sys_enter_registered) { |
| 959 | ret = lttng_wrapper_tracepoint_probe_register("sys_enter", |
| 960 | (void *) syscall_entry_event_notifier_probe, group); |
| 961 | if (ret) |
| 962 | return ret; |
| 963 | group->sys_enter_registered = 1; |
| 964 | } |
| 965 | |
| 966 | if (!group->sys_exit_registered) { |
| 967 | ret = lttng_wrapper_tracepoint_probe_register("sys_exit", |
| 968 | (void *) syscall_exit_event_notifier_probe, group); |
| 969 | if (ret) { |
| 970 | WARN_ON_ONCE(lttng_wrapper_tracepoint_probe_unregister("sys_enter", |
| 971 | (void *) syscall_entry_event_notifier_probe, group)); |
| 972 | return ret; |
| 973 | } |
| 974 | group->sys_exit_registered = 1; |
| 975 | } |
| 976 | |
| 977 | return ret; |
| 978 | } |
| 979 | |
| 980 | static |
| 981 | int create_unknown_event_notifier( |
| 982 | struct lttng_event_notifier_enabler *event_notifier_enabler, |
| 983 | enum sc_type type) |
| 984 | { |
| 985 | struct lttng_kernel_event_notifier_private *event_notifier_priv; |
| 986 | struct lttng_kernel_event_notifier *event_notifier; |
| 987 | const struct lttng_kernel_event_desc *desc; |
| 988 | struct lttng_event_notifier_group *group = event_notifier_enabler->group; |
| 989 | struct lttng_kernel_abi_event_notifier event_notifier_param; |
| 990 | uint64_t user_token = event_notifier_enabler->base.user_token; |
| 991 | uint64_t error_counter_index = event_notifier_enabler->error_counter_index; |
| 992 | struct lttng_enabler *base_enabler = lttng_event_notifier_enabler_as_enabler( |
| 993 | event_notifier_enabler); |
| 994 | struct hlist_head *unknown_dispatch_list; |
| 995 | int ret = 0; |
| 996 | bool found = false; |
| 997 | enum lttng_kernel_abi_syscall_abi abi; |
| 998 | enum lttng_kernel_abi_syscall_entryexit entryexit; |
| 999 | struct hlist_head *head; |
| 1000 | |
| 1001 | switch (type) { |
| 1002 | case SC_TYPE_ENTRY: |
| 1003 | desc = &__event_desc___syscall_entry_unknown; |
| 1004 | unknown_dispatch_list = &group->event_notifier_unknown_syscall_dispatch; |
| 1005 | entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY; |
| 1006 | abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE; |
| 1007 | break; |
| 1008 | case SC_TYPE_EXIT: |
| 1009 | desc = &__event_desc___syscall_exit_unknown; |
| 1010 | unknown_dispatch_list = &group->event_notifier_exit_unknown_syscall_dispatch; |
| 1011 | entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT; |
| 1012 | abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE; |
| 1013 | break; |
| 1014 | case SC_TYPE_COMPAT_ENTRY: |
| 1015 | desc = &__event_desc___compat_syscall_entry_unknown; |
| 1016 | unknown_dispatch_list = &group->event_notifier_compat_unknown_syscall_dispatch; |
| 1017 | entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY; |
| 1018 | abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT; |
| 1019 | break; |
| 1020 | case SC_TYPE_COMPAT_EXIT: |
| 1021 | desc = &__event_desc___compat_syscall_exit_unknown; |
| 1022 | unknown_dispatch_list = &group->event_notifier_exit_compat_unknown_syscall_dispatch; |
| 1023 | entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT; |
| 1024 | abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT; |
| 1025 | break; |
| 1026 | default: |
| 1027 | BUG_ON(1); |
| 1028 | } |
| 1029 | |
| 1030 | /* |
| 1031 | * Check if already created. |
| 1032 | */ |
| 1033 | head = utils_borrow_hash_table_bucket(group->event_notifiers_ht.table, |
| 1034 | LTTNG_EVENT_NOTIFIER_HT_SIZE, desc->event_name); |
| 1035 | lttng_hlist_for_each_entry(event_notifier_priv, head, hlist) { |
| 1036 | if (event_notifier_priv->parent.desc == desc && |
| 1037 | event_notifier_priv->parent.user_token == base_enabler->user_token) |
| 1038 | found = true; |
| 1039 | } |
| 1040 | if (found) |
| 1041 | goto end; |
| 1042 | |
| 1043 | memset(&event_notifier_param, 0, sizeof(event_notifier_param)); |
| 1044 | strncat(event_notifier_param.event.name, desc->event_name, |
| 1045 | LTTNG_KERNEL_ABI_SYM_NAME_LEN - strlen(event_notifier_param.event.name) - 1); |
| 1046 | |
| 1047 | event_notifier_param.event.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0'; |
| 1048 | |
| 1049 | event_notifier_param.event.instrumentation = LTTNG_KERNEL_ABI_SYSCALL; |
| 1050 | event_notifier_param.event.u.syscall.abi = abi; |
| 1051 | event_notifier_param.event.u.syscall.entryexit = entryexit; |
| 1052 | |
| 1053 | event_notifier = _lttng_event_notifier_create(desc, user_token, |
| 1054 | error_counter_index, group, &event_notifier_param, |
| 1055 | event_notifier_param.event.instrumentation); |
| 1056 | if (IS_ERR(event_notifier)) { |
| 1057 | printk(KERN_INFO "Unable to create unknown notifier %s\n", |
| 1058 | desc->event_name); |
| 1059 | ret = -ENOMEM; |
| 1060 | goto end; |
| 1061 | } |
| 1062 | |
| 1063 | hlist_add_head_rcu(&event_notifier->priv->parent.u.syscall.node, unknown_dispatch_list); |
| 1064 | |
| 1065 | end: |
| 1066 | return ret; |
| 1067 | } |
| 1068 | |
| 1069 | static int create_matching_event_notifiers( |
| 1070 | struct lttng_event_notifier_enabler *event_notifier_enabler, |
| 1071 | const struct trace_syscall_entry *table, |
| 1072 | size_t table_len, enum sc_type type) |
| 1073 | { |
| 1074 | struct lttng_event_notifier_group *group = event_notifier_enabler->group; |
| 1075 | const struct lttng_kernel_event_desc *desc; |
| 1076 | uint64_t user_token = event_notifier_enabler->base.user_token; |
| 1077 | uint64_t error_counter_index = event_notifier_enabler->error_counter_index; |
| 1078 | unsigned int i; |
| 1079 | int ret = 0; |
| 1080 | |
| 1081 | /* iterate over all syscall and create event_notifier that match */ |
| 1082 | for (i = 0; i < table_len; i++) { |
| 1083 | struct lttng_kernel_event_notifier_private *event_notifier_priv; |
| 1084 | struct lttng_kernel_event_notifier *event_notifier; |
| 1085 | struct lttng_kernel_abi_event_notifier event_notifier_param; |
| 1086 | struct hlist_head *head; |
| 1087 | int found = 0; |
| 1088 | |
| 1089 | desc = table[i].desc; |
| 1090 | if (!desc) { |
| 1091 | /* Unknown syscall */ |
| 1092 | continue; |
| 1093 | } |
| 1094 | |
| 1095 | if (!lttng_desc_match_enabler(desc, |
| 1096 | lttng_event_notifier_enabler_as_enabler(event_notifier_enabler))) |
| 1097 | continue; |
| 1098 | |
| 1099 | /* |
| 1100 | * Check if already created. |
| 1101 | */ |
| 1102 | head = utils_borrow_hash_table_bucket(group->event_notifiers_ht.table, |
| 1103 | LTTNG_EVENT_NOTIFIER_HT_SIZE, desc->event_name); |
| 1104 | lttng_hlist_for_each_entry(event_notifier_priv, head, hlist) { |
| 1105 | if (event_notifier_priv->parent.desc == desc |
| 1106 | && event_notifier_priv->parent.user_token == event_notifier_enabler->base.user_token) |
| 1107 | found = 1; |
| 1108 | } |
| 1109 | if (found) |
| 1110 | continue; |
| 1111 | |
| 1112 | memset(&event_notifier_param, 0, sizeof(event_notifier_param)); |
| 1113 | switch (type) { |
| 1114 | case SC_TYPE_ENTRY: |
| 1115 | event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY; |
| 1116 | event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE; |
| 1117 | break; |
| 1118 | case SC_TYPE_EXIT: |
| 1119 | event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT; |
| 1120 | event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE; |
| 1121 | break; |
| 1122 | case SC_TYPE_COMPAT_ENTRY: |
| 1123 | event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY; |
| 1124 | event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT; |
| 1125 | break; |
| 1126 | case SC_TYPE_COMPAT_EXIT: |
| 1127 | event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT; |
| 1128 | event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT; |
| 1129 | break; |
| 1130 | } |
| 1131 | strncat(event_notifier_param.event.name, desc->event_name, |
| 1132 | LTTNG_KERNEL_ABI_SYM_NAME_LEN - strlen(event_notifier_param.event.name) - 1); |
| 1133 | event_notifier_param.event.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0'; |
| 1134 | event_notifier_param.event.instrumentation = LTTNG_KERNEL_ABI_SYSCALL; |
| 1135 | |
| 1136 | event_notifier = _lttng_event_notifier_create(desc, user_token, |
| 1137 | error_counter_index, group, &event_notifier_param, |
| 1138 | event_notifier_param.event.instrumentation); |
| 1139 | if (IS_ERR(event_notifier)) { |
| 1140 | printk(KERN_INFO "Unable to create event_notifier %s\n", |
| 1141 | desc->event_name); |
| 1142 | ret = -ENOMEM; |
| 1143 | goto end; |
| 1144 | } |
| 1145 | |
| 1146 | event_notifier->priv->parent.u.syscall.syscall_id = i; |
| 1147 | } |
| 1148 | |
| 1149 | end: |
| 1150 | return ret; |
| 1151 | |
| 1152 | } |
| 1153 | |
| 1154 | int lttng_syscalls_create_matching_event_notifiers( |
| 1155 | struct lttng_event_notifier_enabler *event_notifier_enabler) |
| 1156 | { |
| 1157 | int ret; |
| 1158 | struct lttng_enabler *base_enabler = |
| 1159 | lttng_event_notifier_enabler_as_enabler(event_notifier_enabler); |
| 1160 | enum lttng_kernel_abi_syscall_entryexit entryexit = |
| 1161 | base_enabler->event_param.u.syscall.entryexit; |
| 1162 | |
| 1163 | if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT) { |
| 1164 | ret = create_matching_event_notifiers(event_notifier_enabler, |
| 1165 | sc_table.table, sc_table.len, SC_TYPE_ENTRY); |
| 1166 | if (ret) |
| 1167 | goto end; |
| 1168 | |
| 1169 | ret = create_matching_event_notifiers(event_notifier_enabler, |
| 1170 | compat_sc_table.table, compat_sc_table.len, |
| 1171 | SC_TYPE_COMPAT_ENTRY); |
| 1172 | if (ret) |
| 1173 | goto end; |
| 1174 | |
| 1175 | ret = create_unknown_event_notifier(event_notifier_enabler, |
| 1176 | SC_TYPE_ENTRY); |
| 1177 | if (ret) |
| 1178 | goto end; |
| 1179 | |
| 1180 | ret = create_unknown_event_notifier(event_notifier_enabler, |
| 1181 | SC_TYPE_COMPAT_ENTRY); |
| 1182 | if (ret) |
| 1183 | goto end; |
| 1184 | } |
| 1185 | |
| 1186 | if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT) { |
| 1187 | ret = create_matching_event_notifiers(event_notifier_enabler, |
| 1188 | sc_exit_table.table, sc_exit_table.len, |
| 1189 | SC_TYPE_EXIT); |
| 1190 | if (ret) |
| 1191 | goto end; |
| 1192 | |
| 1193 | ret = create_unknown_event_notifier(event_notifier_enabler, |
| 1194 | SC_TYPE_EXIT); |
| 1195 | if (ret) |
| 1196 | goto end; |
| 1197 | |
| 1198 | ret = create_matching_event_notifiers(event_notifier_enabler, |
| 1199 | compat_sc_exit_table.table, compat_sc_exit_table.len, |
| 1200 | SC_TYPE_COMPAT_EXIT); |
| 1201 | if (ret) |
| 1202 | goto end; |
| 1203 | |
| 1204 | ret = create_unknown_event_notifier(event_notifier_enabler, |
| 1205 | SC_TYPE_COMPAT_EXIT); |
| 1206 | if (ret) |
| 1207 | goto end; |
| 1208 | } |
| 1209 | |
| 1210 | end: |
| 1211 | return ret; |
| 1212 | } |
| 1213 | |
| 1214 | /* |
| 1215 | * Unregister the syscall event_notifier probes from the callsites. |
| 1216 | */ |
| 1217 | int lttng_syscalls_unregister_event_notifier_group( |
| 1218 | struct lttng_event_notifier_group *event_notifier_group) |
| 1219 | { |
| 1220 | int ret; |
| 1221 | |
| 1222 | /* |
| 1223 | * Only register the event_notifier probe on the `sys_enter` callsite for now. |
| 1224 | * At the moment, we don't think it's desirable to have one fired |
| 1225 | * event_notifier for the entry and one for the exit of a syscall. |
| 1226 | */ |
| 1227 | if (event_notifier_group->sys_enter_registered) { |
| 1228 | ret = lttng_wrapper_tracepoint_probe_unregister("sys_enter", |
| 1229 | (void *) syscall_entry_event_notifier_probe, event_notifier_group); |
| 1230 | if (ret) |
| 1231 | return ret; |
| 1232 | event_notifier_group->sys_enter_registered = 0; |
| 1233 | } |
| 1234 | if (event_notifier_group->sys_exit_registered) { |
| 1235 | ret = lttng_wrapper_tracepoint_probe_unregister("sys_exit", |
| 1236 | (void *) syscall_exit_event_notifier_probe, event_notifier_group); |
| 1237 | if (ret) |
| 1238 | return ret; |
| 1239 | event_notifier_group->sys_enter_registered = 0; |
| 1240 | } |
| 1241 | |
| 1242 | kfree(event_notifier_group->event_notifier_syscall_dispatch); |
| 1243 | kfree(event_notifier_group->event_notifier_exit_syscall_dispatch); |
| 1244 | #ifdef CONFIG_COMPAT |
| 1245 | kfree(event_notifier_group->event_notifier_compat_syscall_dispatch); |
| 1246 | kfree(event_notifier_group->event_notifier_exit_compat_syscall_dispatch); |
| 1247 | #endif |
| 1248 | return 0; |
| 1249 | } |
| 1250 | |
| 1251 | int lttng_syscalls_unregister_channel(struct lttng_kernel_channel_buffer *chan) |
| 1252 | { |
| 1253 | int ret; |
| 1254 | |
| 1255 | if (!chan->priv->parent.sc_table) |
| 1256 | return 0; |
| 1257 | if (chan->priv->parent.sys_enter_registered) { |
| 1258 | ret = lttng_wrapper_tracepoint_probe_unregister("sys_enter", |
| 1259 | (void *) syscall_entry_event_probe, chan); |
| 1260 | if (ret) |
| 1261 | return ret; |
| 1262 | chan->priv->parent.sys_enter_registered = 0; |
| 1263 | } |
| 1264 | if (chan->priv->parent.sys_exit_registered) { |
| 1265 | ret = lttng_wrapper_tracepoint_probe_unregister("sys_exit", |
| 1266 | (void *) syscall_exit_event_probe, chan); |
| 1267 | if (ret) |
| 1268 | return ret; |
| 1269 | chan->priv->parent.sys_exit_registered = 0; |
| 1270 | } |
| 1271 | return 0; |
| 1272 | } |
| 1273 | |
| 1274 | int lttng_syscalls_destroy_event(struct lttng_kernel_channel_buffer *chan) |
| 1275 | { |
| 1276 | kfree(chan->priv->parent.sc_table); |
| 1277 | kfree(chan->priv->parent.sc_exit_table); |
| 1278 | #ifdef CONFIG_COMPAT |
| 1279 | kfree(chan->priv->parent.compat_sc_table); |
| 1280 | kfree(chan->priv->parent.compat_sc_exit_table); |
| 1281 | #endif |
| 1282 | kfree(chan->priv->parent.sc_filter); |
| 1283 | return 0; |
| 1284 | } |
| 1285 | |
| 1286 | static |
| 1287 | int get_syscall_nr(const char *syscall_name) |
| 1288 | { |
| 1289 | int syscall_nr = -1; |
| 1290 | int i; |
| 1291 | |
| 1292 | for (i = 0; i < sc_table.len; i++) { |
| 1293 | const struct trace_syscall_entry *entry; |
| 1294 | const char *it_name; |
| 1295 | |
| 1296 | entry = &sc_table.table[i]; |
| 1297 | if (!entry->desc) |
| 1298 | continue; |
| 1299 | it_name = entry->desc->event_name; |
| 1300 | it_name += strlen(SYSCALL_ENTRY_STR); |
| 1301 | if (!strcmp(syscall_name, it_name)) { |
| 1302 | syscall_nr = i; |
| 1303 | break; |
| 1304 | } |
| 1305 | } |
| 1306 | return syscall_nr; |
| 1307 | } |
| 1308 | |
| 1309 | static |
| 1310 | int get_compat_syscall_nr(const char *syscall_name) |
| 1311 | { |
| 1312 | int syscall_nr = -1; |
| 1313 | int i; |
| 1314 | |
| 1315 | for (i = 0; i < compat_sc_table.len; i++) { |
| 1316 | const struct trace_syscall_entry *entry; |
| 1317 | const char *it_name; |
| 1318 | |
| 1319 | entry = &compat_sc_table.table[i]; |
| 1320 | if (!entry->desc) |
| 1321 | continue; |
| 1322 | it_name = entry->desc->event_name; |
| 1323 | it_name += strlen(COMPAT_SYSCALL_ENTRY_STR); |
| 1324 | if (!strcmp(syscall_name, it_name)) { |
| 1325 | syscall_nr = i; |
| 1326 | break; |
| 1327 | } |
| 1328 | } |
| 1329 | return syscall_nr; |
| 1330 | } |
| 1331 | |
| 1332 | static |
| 1333 | uint32_t get_sc_tables_len(void) |
| 1334 | { |
| 1335 | return sc_table.len + compat_sc_table.len; |
| 1336 | } |
| 1337 | |
| 1338 | static |
| 1339 | const char *get_syscall_name(const char *desc_name, |
| 1340 | enum lttng_syscall_abi abi, |
| 1341 | enum lttng_syscall_entryexit entryexit) |
| 1342 | { |
| 1343 | size_t prefix_len = 0; |
| 1344 | |
| 1345 | |
| 1346 | switch (entryexit) { |
| 1347 | case LTTNG_SYSCALL_ENTRY: |
| 1348 | switch (abi) { |
| 1349 | case LTTNG_SYSCALL_ABI_NATIVE: |
| 1350 | prefix_len = strlen(SYSCALL_ENTRY_STR); |
| 1351 | break; |
| 1352 | case LTTNG_SYSCALL_ABI_COMPAT: |
| 1353 | prefix_len = strlen(COMPAT_SYSCALL_ENTRY_STR); |
| 1354 | break; |
| 1355 | } |
| 1356 | break; |
| 1357 | case LTTNG_SYSCALL_EXIT: |
| 1358 | switch (abi) { |
| 1359 | case LTTNG_SYSCALL_ABI_NATIVE: |
| 1360 | prefix_len = strlen(SYSCALL_EXIT_STR); |
| 1361 | break; |
| 1362 | case LTTNG_SYSCALL_ABI_COMPAT: |
| 1363 | prefix_len = strlen(COMPAT_SYSCALL_EXIT_STR); |
| 1364 | break; |
| 1365 | } |
| 1366 | break; |
| 1367 | } |
| 1368 | WARN_ON_ONCE(prefix_len == 0); |
| 1369 | return desc_name + prefix_len; |
| 1370 | } |
| 1371 | |
| 1372 | static |
| 1373 | int lttng_syscall_filter_enable( |
| 1374 | struct lttng_syscall_filter *filter, |
| 1375 | const char *desc_name, enum lttng_syscall_abi abi, |
| 1376 | enum lttng_syscall_entryexit entryexit) |
| 1377 | { |
| 1378 | const char *syscall_name; |
| 1379 | unsigned long *bitmap; |
| 1380 | u32 *refcount_map; |
| 1381 | int syscall_nr; |
| 1382 | |
| 1383 | syscall_name = get_syscall_name(desc_name, abi, entryexit); |
| 1384 | |
| 1385 | switch (abi) { |
| 1386 | case LTTNG_SYSCALL_ABI_NATIVE: |
| 1387 | syscall_nr = get_syscall_nr(syscall_name); |
| 1388 | break; |
| 1389 | case LTTNG_SYSCALL_ABI_COMPAT: |
| 1390 | syscall_nr = get_compat_syscall_nr(syscall_name); |
| 1391 | break; |
| 1392 | default: |
| 1393 | return -EINVAL; |
| 1394 | } |
| 1395 | if (syscall_nr < 0) |
| 1396 | return -ENOENT; |
| 1397 | |
| 1398 | switch (entryexit) { |
| 1399 | case LTTNG_SYSCALL_ENTRY: |
| 1400 | switch (abi) { |
| 1401 | case LTTNG_SYSCALL_ABI_NATIVE: |
| 1402 | bitmap = filter->sc_entry; |
| 1403 | refcount_map = filter->sc_entry_refcount_map; |
| 1404 | break; |
| 1405 | case LTTNG_SYSCALL_ABI_COMPAT: |
| 1406 | bitmap = filter->sc_compat_entry; |
| 1407 | refcount_map = filter->sc_compat_entry_refcount_map; |
| 1408 | break; |
| 1409 | default: |
| 1410 | return -EINVAL; |
| 1411 | } |
| 1412 | break; |
| 1413 | case LTTNG_SYSCALL_EXIT: |
| 1414 | switch (abi) { |
| 1415 | case LTTNG_SYSCALL_ABI_NATIVE: |
| 1416 | bitmap = filter->sc_exit; |
| 1417 | refcount_map = filter->sc_exit_refcount_map; |
| 1418 | break; |
| 1419 | case LTTNG_SYSCALL_ABI_COMPAT: |
| 1420 | bitmap = filter->sc_compat_exit; |
| 1421 | refcount_map = filter->sc_compat_exit_refcount_map; |
| 1422 | break; |
| 1423 | default: |
| 1424 | return -EINVAL; |
| 1425 | } |
| 1426 | break; |
| 1427 | default: |
| 1428 | return -EINVAL; |
| 1429 | } |
| 1430 | if (refcount_map[syscall_nr] == U32_MAX) |
| 1431 | return -EOVERFLOW; |
| 1432 | if (refcount_map[syscall_nr]++ == 0) |
| 1433 | bitmap_set(bitmap, syscall_nr, 1); |
| 1434 | return 0; |
| 1435 | } |
| 1436 | |
| 1437 | int lttng_syscall_filter_enable_event_notifier( |
| 1438 | struct lttng_kernel_event_notifier *event_notifier) |
| 1439 | { |
| 1440 | struct lttng_event_notifier_group *group = event_notifier->priv->group; |
| 1441 | unsigned int syscall_id = event_notifier->priv->parent.u.syscall.syscall_id; |
| 1442 | struct hlist_head *dispatch_list; |
| 1443 | int ret = 0; |
| 1444 | |
| 1445 | WARN_ON_ONCE(event_notifier->priv->parent.instrumentation != LTTNG_KERNEL_ABI_SYSCALL); |
| 1446 | |
| 1447 | /* Skip unknown syscall */ |
| 1448 | if (syscall_id == -1U) |
| 1449 | return 0; |
| 1450 | |
| 1451 | ret = lttng_syscall_filter_enable(group->sc_filter, |
| 1452 | event_notifier->priv->parent.desc->event_name, |
| 1453 | event_notifier->priv->parent.u.syscall.abi, |
| 1454 | event_notifier->priv->parent.u.syscall.entryexit); |
| 1455 | if (ret) |
| 1456 | return ret; |
| 1457 | |
| 1458 | switch (event_notifier->priv->parent.u.syscall.entryexit) { |
| 1459 | case LTTNG_SYSCALL_ENTRY: |
| 1460 | switch (event_notifier->priv->parent.u.syscall.abi) { |
| 1461 | case LTTNG_SYSCALL_ABI_NATIVE: |
| 1462 | dispatch_list = &group->event_notifier_syscall_dispatch[syscall_id]; |
| 1463 | break; |
| 1464 | case LTTNG_SYSCALL_ABI_COMPAT: |
| 1465 | dispatch_list = &group->event_notifier_compat_syscall_dispatch[syscall_id]; |
| 1466 | break; |
| 1467 | default: |
| 1468 | ret = -EINVAL; |
| 1469 | goto end; |
| 1470 | } |
| 1471 | break; |
| 1472 | case LTTNG_SYSCALL_EXIT: |
| 1473 | switch (event_notifier->priv->parent.u.syscall.abi) { |
| 1474 | case LTTNG_SYSCALL_ABI_NATIVE: |
| 1475 | dispatch_list = &group->event_notifier_exit_syscall_dispatch[syscall_id]; |
| 1476 | break; |
| 1477 | case LTTNG_SYSCALL_ABI_COMPAT: |
| 1478 | dispatch_list = &group->event_notifier_exit_compat_syscall_dispatch[syscall_id]; |
| 1479 | break; |
| 1480 | default: |
| 1481 | ret = -EINVAL; |
| 1482 | goto end; |
| 1483 | } |
| 1484 | break; |
| 1485 | default: |
| 1486 | ret = -EINVAL; |
| 1487 | goto end; |
| 1488 | } |
| 1489 | |
| 1490 | hlist_add_head_rcu(&event_notifier->priv->parent.u.syscall.node, dispatch_list); |
| 1491 | |
| 1492 | end: |
| 1493 | return ret; |
| 1494 | } |
| 1495 | |
| 1496 | int lttng_syscall_filter_enable_event( |
| 1497 | struct lttng_kernel_channel_buffer *channel, |
| 1498 | struct lttng_kernel_event_recorder *event_recorder) |
| 1499 | { |
| 1500 | unsigned int syscall_id = event_recorder->priv->parent.u.syscall.syscall_id; |
| 1501 | |
| 1502 | WARN_ON_ONCE(event_recorder->priv->parent.instrumentation != LTTNG_KERNEL_ABI_SYSCALL); |
| 1503 | |
| 1504 | /* Skip unknown syscall */ |
| 1505 | if (syscall_id == -1U) |
| 1506 | return 0; |
| 1507 | |
| 1508 | return lttng_syscall_filter_enable(channel->priv->parent.sc_filter, |
| 1509 | event_recorder->priv->parent.desc->event_name, |
| 1510 | event_recorder->priv->parent.u.syscall.abi, |
| 1511 | event_recorder->priv->parent.u.syscall.entryexit); |
| 1512 | } |
| 1513 | |
| 1514 | static |
| 1515 | int lttng_syscall_filter_disable( |
| 1516 | struct lttng_syscall_filter *filter, |
| 1517 | const char *desc_name, enum lttng_syscall_abi abi, |
| 1518 | enum lttng_syscall_entryexit entryexit) |
| 1519 | { |
| 1520 | const char *syscall_name; |
| 1521 | unsigned long *bitmap; |
| 1522 | u32 *refcount_map; |
| 1523 | int syscall_nr; |
| 1524 | |
| 1525 | syscall_name = get_syscall_name(desc_name, abi, entryexit); |
| 1526 | |
| 1527 | switch (abi) { |
| 1528 | case LTTNG_SYSCALL_ABI_NATIVE: |
| 1529 | syscall_nr = get_syscall_nr(syscall_name); |
| 1530 | break; |
| 1531 | case LTTNG_SYSCALL_ABI_COMPAT: |
| 1532 | syscall_nr = get_compat_syscall_nr(syscall_name); |
| 1533 | break; |
| 1534 | default: |
| 1535 | return -EINVAL; |
| 1536 | } |
| 1537 | if (syscall_nr < 0) |
| 1538 | return -ENOENT; |
| 1539 | |
| 1540 | switch (entryexit) { |
| 1541 | case LTTNG_SYSCALL_ENTRY: |
| 1542 | switch (abi) { |
| 1543 | case LTTNG_SYSCALL_ABI_NATIVE: |
| 1544 | bitmap = filter->sc_entry; |
| 1545 | refcount_map = filter->sc_entry_refcount_map; |
| 1546 | break; |
| 1547 | case LTTNG_SYSCALL_ABI_COMPAT: |
| 1548 | bitmap = filter->sc_compat_entry; |
| 1549 | refcount_map = filter->sc_compat_entry_refcount_map; |
| 1550 | break; |
| 1551 | default: |
| 1552 | return -EINVAL; |
| 1553 | } |
| 1554 | break; |
| 1555 | case LTTNG_SYSCALL_EXIT: |
| 1556 | switch (abi) { |
| 1557 | case LTTNG_SYSCALL_ABI_NATIVE: |
| 1558 | bitmap = filter->sc_exit; |
| 1559 | refcount_map = filter->sc_exit_refcount_map; |
| 1560 | break; |
| 1561 | case LTTNG_SYSCALL_ABI_COMPAT: |
| 1562 | bitmap = filter->sc_compat_exit; |
| 1563 | refcount_map = filter->sc_compat_exit_refcount_map; |
| 1564 | break; |
| 1565 | default: |
| 1566 | return -EINVAL; |
| 1567 | } |
| 1568 | break; |
| 1569 | default: |
| 1570 | return -EINVAL; |
| 1571 | } |
| 1572 | if (refcount_map[syscall_nr] == 0) |
| 1573 | return -ENOENT; |
| 1574 | if (--refcount_map[syscall_nr] == 0) |
| 1575 | bitmap_clear(bitmap, syscall_nr, 1); |
| 1576 | return 0; |
| 1577 | } |
| 1578 | |
| 1579 | int lttng_syscall_filter_disable_event_notifier( |
| 1580 | struct lttng_kernel_event_notifier *event_notifier) |
| 1581 | { |
| 1582 | struct lttng_event_notifier_group *group = event_notifier->priv->group; |
| 1583 | unsigned int syscall_id = event_notifier->priv->parent.u.syscall.syscall_id; |
| 1584 | int ret; |
| 1585 | |
| 1586 | WARN_ON_ONCE(event_notifier->priv->parent.instrumentation != LTTNG_KERNEL_ABI_SYSCALL); |
| 1587 | |
| 1588 | /* Skip unknown syscall */ |
| 1589 | if (syscall_id == -1U) |
| 1590 | return 0; |
| 1591 | |
| 1592 | ret = lttng_syscall_filter_disable(group->sc_filter, |
| 1593 | event_notifier->priv->parent.desc->event_name, |
| 1594 | event_notifier->priv->parent.u.syscall.abi, |
| 1595 | event_notifier->priv->parent.u.syscall.entryexit); |
| 1596 | if (ret) |
| 1597 | return ret; |
| 1598 | |
| 1599 | hlist_del_rcu(&event_notifier->priv->parent.u.syscall.node); |
| 1600 | return 0; |
| 1601 | } |
| 1602 | |
| 1603 | int lttng_syscall_filter_disable_event( |
| 1604 | struct lttng_kernel_channel_buffer *channel, |
| 1605 | struct lttng_kernel_event_recorder *event_recorder) |
| 1606 | { |
| 1607 | unsigned int syscall_id = event_recorder->priv->parent.u.syscall.syscall_id; |
| 1608 | |
| 1609 | /* Skip unknown syscall */ |
| 1610 | if (syscall_id == -1U) |
| 1611 | return 0; |
| 1612 | |
| 1613 | return lttng_syscall_filter_disable(channel->priv->parent.sc_filter, |
| 1614 | event_recorder->priv->parent.desc->event_name, |
| 1615 | event_recorder->priv->parent.u.syscall.abi, |
| 1616 | event_recorder->priv->parent.u.syscall.entryexit); |
| 1617 | } |
| 1618 | |
| 1619 | static |
| 1620 | const struct trace_syscall_entry *syscall_list_get_entry(loff_t *pos) |
| 1621 | { |
| 1622 | const struct trace_syscall_entry *entry; |
| 1623 | int iter = 0; |
| 1624 | |
| 1625 | for (entry = sc_table.table; |
| 1626 | entry < sc_table.table + sc_table.len; |
| 1627 | entry++) { |
| 1628 | if (iter++ >= *pos) |
| 1629 | return entry; |
| 1630 | } |
| 1631 | for (entry = compat_sc_table.table; |
| 1632 | entry < compat_sc_table.table + compat_sc_table.len; |
| 1633 | entry++) { |
| 1634 | if (iter++ >= *pos) |
| 1635 | return entry; |
| 1636 | } |
| 1637 | /* End of list */ |
| 1638 | return NULL; |
| 1639 | } |
| 1640 | |
| 1641 | static |
| 1642 | void *syscall_list_start(struct seq_file *m, loff_t *pos) |
| 1643 | { |
| 1644 | return (void *) syscall_list_get_entry(pos); |
| 1645 | } |
| 1646 | |
| 1647 | static |
| 1648 | void *syscall_list_next(struct seq_file *m, void *p, loff_t *ppos) |
| 1649 | { |
| 1650 | (*ppos)++; |
| 1651 | return (void *) syscall_list_get_entry(ppos); |
| 1652 | } |
| 1653 | |
| 1654 | static |
| 1655 | void syscall_list_stop(struct seq_file *m, void *p) |
| 1656 | { |
| 1657 | } |
| 1658 | |
| 1659 | static |
| 1660 | int get_sc_table(const struct trace_syscall_entry *entry, |
| 1661 | const struct trace_syscall_entry **table, |
| 1662 | unsigned int *bitness) |
| 1663 | { |
| 1664 | if (entry >= sc_table.table && entry < sc_table.table + sc_table.len) { |
| 1665 | if (bitness) |
| 1666 | *bitness = BITS_PER_LONG; |
| 1667 | if (table) |
| 1668 | *table = sc_table.table; |
| 1669 | return 0; |
| 1670 | } |
| 1671 | if (!(entry >= compat_sc_table.table |
| 1672 | && entry < compat_sc_table.table + compat_sc_table.len)) { |
| 1673 | return -EINVAL; |
| 1674 | } |
| 1675 | if (bitness) |
| 1676 | *bitness = 32; |
| 1677 | if (table) |
| 1678 | *table = compat_sc_table.table; |
| 1679 | return 0; |
| 1680 | } |
| 1681 | |
| 1682 | static |
| 1683 | int syscall_list_show(struct seq_file *m, void *p) |
| 1684 | { |
| 1685 | const struct trace_syscall_entry *table, *entry = p; |
| 1686 | unsigned int bitness; |
| 1687 | unsigned long index; |
| 1688 | int ret; |
| 1689 | const char *name; |
| 1690 | |
| 1691 | ret = get_sc_table(entry, &table, &bitness); |
| 1692 | if (ret) |
| 1693 | return ret; |
| 1694 | if (!entry->desc) |
| 1695 | return 0; |
| 1696 | if (table == sc_table.table) { |
| 1697 | index = entry - table; |
| 1698 | name = &entry->desc->event_name[strlen(SYSCALL_ENTRY_STR)]; |
| 1699 | } else { |
| 1700 | index = (entry - table) + sc_table.len; |
| 1701 | name = &entry->desc->event_name[strlen(COMPAT_SYSCALL_ENTRY_STR)]; |
| 1702 | } |
| 1703 | seq_printf(m, "syscall { index = %lu; name = %s; bitness = %u; };\n", |
| 1704 | index, name, bitness); |
| 1705 | return 0; |
| 1706 | } |
| 1707 | |
| 1708 | static |
| 1709 | const struct seq_operations lttng_syscall_list_seq_ops = { |
| 1710 | .start = syscall_list_start, |
| 1711 | .next = syscall_list_next, |
| 1712 | .stop = syscall_list_stop, |
| 1713 | .show = syscall_list_show, |
| 1714 | }; |
| 1715 | |
| 1716 | static |
| 1717 | int lttng_syscall_list_open(struct inode *inode, struct file *file) |
| 1718 | { |
| 1719 | return seq_open(file, <tng_syscall_list_seq_ops); |
| 1720 | } |
| 1721 | |
| 1722 | const struct file_operations lttng_syscall_list_fops = { |
| 1723 | .owner = THIS_MODULE, |
| 1724 | .open = lttng_syscall_list_open, |
| 1725 | .read = seq_read, |
| 1726 | .llseek = seq_lseek, |
| 1727 | .release = seq_release, |
| 1728 | }; |
| 1729 | |
| 1730 | /* |
| 1731 | * A syscall is enabled if it is traced for either entry or exit. |
| 1732 | */ |
| 1733 | long lttng_channel_syscall_mask(struct lttng_kernel_channel_buffer *channel, |
| 1734 | struct lttng_kernel_abi_syscall_mask __user *usyscall_mask) |
| 1735 | { |
| 1736 | uint32_t len, sc_tables_len, bitmask_len; |
| 1737 | int ret = 0, bit; |
| 1738 | char *tmp_mask; |
| 1739 | struct lttng_syscall_filter *filter; |
| 1740 | |
| 1741 | ret = get_user(len, &usyscall_mask->len); |
| 1742 | if (ret) |
| 1743 | return ret; |
| 1744 | sc_tables_len = get_sc_tables_len(); |
| 1745 | bitmask_len = ALIGN(sc_tables_len, 8) >> 3; |
| 1746 | if (len < sc_tables_len) { |
| 1747 | return put_user(sc_tables_len, &usyscall_mask->len); |
| 1748 | } |
| 1749 | /* Array is large enough, we can copy array to user-space. */ |
| 1750 | tmp_mask = kzalloc(bitmask_len, GFP_KERNEL); |
| 1751 | if (!tmp_mask) |
| 1752 | return -ENOMEM; |
| 1753 | filter = channel->priv->parent.sc_filter; |
| 1754 | |
| 1755 | for (bit = 0; bit < sc_table.len; bit++) { |
| 1756 | char state; |
| 1757 | |
| 1758 | if (channel->priv->parent.sc_table) { |
| 1759 | if (!(READ_ONCE(channel->priv->parent.syscall_all_entry) |
| 1760 | || READ_ONCE(channel->priv->parent.syscall_all_exit)) && filter) |
| 1761 | state = test_bit(bit, filter->sc_entry) |
| 1762 | || test_bit(bit, filter->sc_exit); |
| 1763 | else |
| 1764 | state = 1; |
| 1765 | } else { |
| 1766 | state = 0; |
| 1767 | } |
| 1768 | bt_bitfield_write_be(tmp_mask, char, bit, 1, state); |
| 1769 | } |
| 1770 | for (; bit < sc_tables_len; bit++) { |
| 1771 | char state; |
| 1772 | |
| 1773 | if (channel->priv->parent.compat_sc_table) { |
| 1774 | if (!(READ_ONCE(channel->priv->parent.syscall_all_entry) |
| 1775 | || READ_ONCE(channel->priv->parent.syscall_all_exit)) && filter) |
| 1776 | state = test_bit(bit - sc_table.len, |
| 1777 | filter->sc_compat_entry) |
| 1778 | || test_bit(bit - sc_table.len, |
| 1779 | filter->sc_compat_exit); |
| 1780 | else |
| 1781 | state = 1; |
| 1782 | } else { |
| 1783 | state = 0; |
| 1784 | } |
| 1785 | bt_bitfield_write_be(tmp_mask, char, bit, 1, state); |
| 1786 | } |
| 1787 | if (copy_to_user(usyscall_mask->mask, tmp_mask, bitmask_len)) |
| 1788 | ret = -EFAULT; |
| 1789 | kfree(tmp_mask); |
| 1790 | return ret; |
| 1791 | } |
| 1792 | |
| 1793 | int lttng_abi_syscall_list(void) |
| 1794 | { |
| 1795 | struct file *syscall_list_file; |
| 1796 | int file_fd, ret; |
| 1797 | |
| 1798 | file_fd = lttng_get_unused_fd(); |
| 1799 | if (file_fd < 0) { |
| 1800 | ret = file_fd; |
| 1801 | goto fd_error; |
| 1802 | } |
| 1803 | |
| 1804 | syscall_list_file = anon_inode_getfile("[lttng_syscall_list]", |
| 1805 | <tng_syscall_list_fops, |
| 1806 | NULL, O_RDWR); |
| 1807 | if (IS_ERR(syscall_list_file)) { |
| 1808 | ret = PTR_ERR(syscall_list_file); |
| 1809 | goto file_error; |
| 1810 | } |
| 1811 | ret = lttng_syscall_list_fops.open(NULL, syscall_list_file); |
| 1812 | if (ret < 0) |
| 1813 | goto open_error; |
| 1814 | fd_install(file_fd, syscall_list_file); |
| 1815 | return file_fd; |
| 1816 | |
| 1817 | open_error: |
| 1818 | fput(syscall_list_file); |
| 1819 | file_error: |
| 1820 | put_unused_fd(file_fd); |
| 1821 | fd_error: |
| 1822 | return ret; |
| 1823 | } |