| 1 | /* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1) |
| 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 <asm/ptrace.h> |
| 22 | #include <asm/syscall.h> |
| 23 | |
| 24 | #include <lib/bitfield.h> |
| 25 | #include <wrapper/tracepoint.h> |
| 26 | #include <wrapper/file.h> |
| 27 | #include <wrapper/rcu.h> |
| 28 | #include <lttng-events.h> |
| 29 | |
| 30 | #ifndef CONFIG_COMPAT |
| 31 | # ifndef is_compat_task |
| 32 | # define is_compat_task() (0) |
| 33 | # endif |
| 34 | #endif |
| 35 | |
| 36 | /* in_compat_syscall appears in kernel 4.6. */ |
| 37 | #ifndef in_compat_syscall |
| 38 | #define in_compat_syscall() is_compat_task() |
| 39 | #endif |
| 40 | |
| 41 | enum sc_type { |
| 42 | SC_TYPE_ENTRY, |
| 43 | SC_TYPE_EXIT, |
| 44 | SC_TYPE_COMPAT_ENTRY, |
| 45 | SC_TYPE_COMPAT_EXIT, |
| 46 | }; |
| 47 | |
| 48 | #define SYSCALL_ENTRY_TOK syscall_entry_ |
| 49 | #define COMPAT_SYSCALL_ENTRY_TOK compat_syscall_entry_ |
| 50 | #define SYSCALL_EXIT_TOK syscall_exit_ |
| 51 | #define COMPAT_SYSCALL_EXIT_TOK compat_syscall_exit_ |
| 52 | |
| 53 | #define SYSCALL_ENTRY_STR __stringify(SYSCALL_ENTRY_TOK) |
| 54 | #define COMPAT_SYSCALL_ENTRY_STR __stringify(COMPAT_SYSCALL_ENTRY_TOK) |
| 55 | #define SYSCALL_EXIT_STR __stringify(SYSCALL_EXIT_TOK) |
| 56 | #define COMPAT_SYSCALL_EXIT_STR __stringify(COMPAT_SYSCALL_EXIT_TOK) |
| 57 | |
| 58 | static |
| 59 | void syscall_entry_probe(void *__data, struct pt_regs *regs, long id); |
| 60 | static |
| 61 | void syscall_exit_probe(void *__data, struct pt_regs *regs, long ret); |
| 62 | |
| 63 | /* |
| 64 | * Forward declarations for old kernels. |
| 65 | */ |
| 66 | struct mmsghdr; |
| 67 | struct rlimit64; |
| 68 | struct oldold_utsname; |
| 69 | struct old_utsname; |
| 70 | struct sel_arg_struct; |
| 71 | struct mmap_arg_struct; |
| 72 | struct file_handle; |
| 73 | struct user_msghdr; |
| 74 | |
| 75 | #ifdef IA32_NR_syscalls |
| 76 | #define NR_compat_syscalls IA32_NR_syscalls |
| 77 | #else |
| 78 | #define NR_compat_syscalls NR_syscalls |
| 79 | #endif |
| 80 | |
| 81 | /* |
| 82 | * Create LTTng tracepoint probes. |
| 83 | */ |
| 84 | #define LTTNG_PACKAGE_BUILD |
| 85 | #define CREATE_TRACE_POINTS |
| 86 | #define TP_MODULE_NOINIT |
| 87 | #define TRACE_INCLUDE_PATH instrumentation/syscalls/headers |
| 88 | |
| 89 | #define PARAMS(args...) args |
| 90 | |
| 91 | /* Handle unknown syscalls */ |
| 92 | #undef TRACE_SYSTEM |
| 93 | #define TRACE_SYSTEM syscalls_unknown |
| 94 | #include <instrumentation/syscalls/headers/syscalls_unknown.h> |
| 95 | #undef TRACE_SYSTEM |
| 96 | |
| 97 | #define SC_ENTER |
| 98 | |
| 99 | #undef sc_exit |
| 100 | #define sc_exit(...) |
| 101 | #undef sc_in |
| 102 | #define sc_in(...) __VA_ARGS__ |
| 103 | #undef sc_out |
| 104 | #define sc_out(...) |
| 105 | #undef sc_inout |
| 106 | #define sc_inout(...) __VA_ARGS__ |
| 107 | |
| 108 | /* Hijack probe callback for system call enter */ |
| 109 | #undef TP_PROBE_CB |
| 110 | #define TP_PROBE_CB(_template) &syscall_entry_probe |
| 111 | #define SC_LTTNG_TRACEPOINT_EVENT(_name, _proto, _args, _fields) \ |
| 112 | LTTNG_TRACEPOINT_EVENT(syscall_entry_##_name, PARAMS(_proto), PARAMS(_args), \ |
| 113 | PARAMS(_fields)) |
| 114 | #define SC_LTTNG_TRACEPOINT_EVENT_CODE(_name, _proto, _args, _locvar, _code_pre, _fields, _code_post) \ |
| 115 | LTTNG_TRACEPOINT_EVENT_CODE(syscall_entry_##_name, PARAMS(_proto), PARAMS(_args), \ |
| 116 | PARAMS(_locvar), PARAMS(_code_pre), \ |
| 117 | PARAMS(_fields), PARAMS(_code_post)) |
| 118 | #define SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(_name, _fields) \ |
| 119 | LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(syscall_entry_##_name, PARAMS(_fields)) |
| 120 | #define SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(_template, _name) \ |
| 121 | LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(syscall_entry_##_template, syscall_entry_##_name) |
| 122 | /* Enumerations only defined at first inclusion. */ |
| 123 | #define SC_LTTNG_TRACEPOINT_ENUM(_name, _values) \ |
| 124 | LTTNG_TRACEPOINT_ENUM(_name, PARAMS(_values)) |
| 125 | #undef TRACE_SYSTEM |
| 126 | #define TRACE_SYSTEM syscall_entry_integers |
| 127 | #define TRACE_INCLUDE_FILE syscalls_integers |
| 128 | #include <instrumentation/syscalls/headers/syscalls_integers.h> |
| 129 | #undef TRACE_INCLUDE_FILE |
| 130 | #undef TRACE_SYSTEM |
| 131 | #define TRACE_SYSTEM syscall_entry_pointers |
| 132 | #define TRACE_INCLUDE_FILE syscalls_pointers |
| 133 | #include <instrumentation/syscalls/headers/syscalls_pointers.h> |
| 134 | #undef TRACE_INCLUDE_FILE |
| 135 | #undef TRACE_SYSTEM |
| 136 | #undef SC_LTTNG_TRACEPOINT_ENUM |
| 137 | #undef SC_LTTNG_TRACEPOINT_EVENT_CODE |
| 138 | #undef SC_LTTNG_TRACEPOINT_EVENT |
| 139 | #undef SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS |
| 140 | #undef SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS |
| 141 | #undef TP_PROBE_CB |
| 142 | #undef _TRACE_SYSCALLS_INTEGERS_H |
| 143 | #undef _TRACE_SYSCALLS_POINTERS_H |
| 144 | |
| 145 | /* Hijack probe callback for compat system call enter */ |
| 146 | #define TP_PROBE_CB(_template) &syscall_entry_probe |
| 147 | #define LTTNG_SC_COMPAT |
| 148 | #define SC_LTTNG_TRACEPOINT_EVENT(_name, _proto, _args, _fields) \ |
| 149 | LTTNG_TRACEPOINT_EVENT(compat_syscall_entry_##_name, PARAMS(_proto), PARAMS(_args), \ |
| 150 | PARAMS(_fields)) |
| 151 | #define SC_LTTNG_TRACEPOINT_EVENT_CODE(_name, _proto, _args, _locvar, _code_pre, _fields, _code_post) \ |
| 152 | LTTNG_TRACEPOINT_EVENT_CODE(compat_syscall_entry_##_name, PARAMS(_proto), PARAMS(_args), \ |
| 153 | PARAMS(_locvar), PARAMS(_code_pre), PARAMS(_fields), PARAMS(_code_post)) |
| 154 | #define SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(_name, _fields) \ |
| 155 | LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(compat_syscall_entry_##_name, PARAMS(_fields)) |
| 156 | #define SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(_template, _name) \ |
| 157 | LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(compat_syscall_entry_##_template, \ |
| 158 | compat_syscall_entry_##_name) |
| 159 | /* Enumerations only defined at inital inclusion (not here). */ |
| 160 | #define SC_LTTNG_TRACEPOINT_ENUM(_name, _values) |
| 161 | #define TRACE_SYSTEM compat_syscall_entry_integers |
| 162 | #define TRACE_INCLUDE_FILE compat_syscalls_integers |
| 163 | #include <instrumentation/syscalls/headers/compat_syscalls_integers.h> |
| 164 | #undef TRACE_INCLUDE_FILE |
| 165 | #undef TRACE_SYSTEM |
| 166 | #define TRACE_SYSTEM compat_syscall_entry_pointers |
| 167 | #define TRACE_INCLUDE_FILE compat_syscalls_pointers |
| 168 | #include <instrumentation/syscalls/headers/compat_syscalls_pointers.h> |
| 169 | #undef TRACE_INCLUDE_FILE |
| 170 | #undef TRACE_SYSTEM |
| 171 | #undef SC_LTTNG_TRACEPOINT_ENUM |
| 172 | #undef SC_LTTNG_TRACEPOINT_EVENT_CODE |
| 173 | #undef SC_LTTNG_TRACEPOINT_EVENT |
| 174 | #undef SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS |
| 175 | #undef SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS |
| 176 | #undef TP_PROBE_CB |
| 177 | #undef _TRACE_SYSCALLS_INTEGERS_H |
| 178 | #undef _TRACE_SYSCALLS_POINTERS_H |
| 179 | #undef LTTNG_SC_COMPAT |
| 180 | |
| 181 | #undef SC_ENTER |
| 182 | |
| 183 | #define SC_EXIT |
| 184 | |
| 185 | #undef sc_exit |
| 186 | #define sc_exit(...) __VA_ARGS__ |
| 187 | #undef sc_in |
| 188 | #define sc_in(...) |
| 189 | #undef sc_out |
| 190 | #define sc_out(...) __VA_ARGS__ |
| 191 | #undef sc_inout |
| 192 | #define sc_inout(...) __VA_ARGS__ |
| 193 | |
| 194 | /* Hijack probe callback for system call exit */ |
| 195 | #define TP_PROBE_CB(_template) &syscall_exit_probe |
| 196 | #define SC_LTTNG_TRACEPOINT_EVENT(_name, _proto, _args, _fields) \ |
| 197 | LTTNG_TRACEPOINT_EVENT(syscall_exit_##_name, PARAMS(_proto), PARAMS(_args), \ |
| 198 | PARAMS(_fields)) |
| 199 | #define SC_LTTNG_TRACEPOINT_EVENT_CODE(_name, _proto, _args, _locvar, _code_pre, _fields, _code_post) \ |
| 200 | LTTNG_TRACEPOINT_EVENT_CODE(syscall_exit_##_name, PARAMS(_proto), PARAMS(_args), \ |
| 201 | PARAMS(_locvar), PARAMS(_code_pre), PARAMS(_fields), PARAMS(_code_post)) |
| 202 | #define SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(_name, _fields) \ |
| 203 | LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(syscall_exit_##_name, PARAMS(_fields)) |
| 204 | #define SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(_template, _name) \ |
| 205 | LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(syscall_exit_##_template, \ |
| 206 | syscall_exit_##_name) |
| 207 | /* Enumerations only defined at inital inclusion (not here). */ |
| 208 | #define SC_LTTNG_TRACEPOINT_ENUM(_name, _values) |
| 209 | #define TRACE_SYSTEM syscall_exit_integers |
| 210 | #define TRACE_INCLUDE_FILE syscalls_integers |
| 211 | #include <instrumentation/syscalls/headers/syscalls_integers.h> |
| 212 | #undef TRACE_INCLUDE_FILE |
| 213 | #undef TRACE_SYSTEM |
| 214 | #define TRACE_SYSTEM syscall_exit_pointers |
| 215 | #define TRACE_INCLUDE_FILE syscalls_pointers |
| 216 | #include <instrumentation/syscalls/headers/syscalls_pointers.h> |
| 217 | #undef TRACE_INCLUDE_FILE |
| 218 | #undef TRACE_SYSTEM |
| 219 | #undef SC_LTTNG_TRACEPOINT_ENUM |
| 220 | #undef SC_LTTNG_TRACEPOINT_EVENT_CODE |
| 221 | #undef SC_LTTNG_TRACEPOINT_EVENT |
| 222 | #undef SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS |
| 223 | #undef SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS |
| 224 | #undef TP_PROBE_CB |
| 225 | #undef _TRACE_SYSCALLS_INTEGERS_H |
| 226 | #undef _TRACE_SYSCALLS_POINTERS_H |
| 227 | |
| 228 | |
| 229 | /* Hijack probe callback for compat system call exit */ |
| 230 | #define TP_PROBE_CB(_template) &syscall_exit_probe |
| 231 | #define LTTNG_SC_COMPAT |
| 232 | #define SC_LTTNG_TRACEPOINT_EVENT(_name, _proto, _args, _fields) \ |
| 233 | LTTNG_TRACEPOINT_EVENT(compat_syscall_exit_##_name, PARAMS(_proto), PARAMS(_args), \ |
| 234 | PARAMS(_fields)) |
| 235 | #define SC_LTTNG_TRACEPOINT_EVENT_CODE(_name, _proto, _args, _locvar, _code_pre, _fields, _code_post) \ |
| 236 | LTTNG_TRACEPOINT_EVENT_CODE(compat_syscall_exit_##_name, PARAMS(_proto), PARAMS(_args), \ |
| 237 | PARAMS(_locvar), PARAMS(_code_pre), PARAMS(_fields), PARAMS(_code_post)) |
| 238 | #define SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(_name, _fields) \ |
| 239 | LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(compat_syscall_exit_##_name, PARAMS(_fields)) |
| 240 | #define SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(_template, _name) \ |
| 241 | LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(compat_syscall_exit_##_template, \ |
| 242 | compat_syscall_exit_##_name) |
| 243 | /* Enumerations only defined at inital inclusion (not here). */ |
| 244 | #define SC_LTTNG_TRACEPOINT_ENUM(_name, _values) |
| 245 | #define TRACE_SYSTEM compat_syscall_exit_integers |
| 246 | #define TRACE_INCLUDE_FILE compat_syscalls_integers |
| 247 | #include <instrumentation/syscalls/headers/compat_syscalls_integers.h> |
| 248 | #undef TRACE_INCLUDE_FILE |
| 249 | #undef TRACE_SYSTEM |
| 250 | #define TRACE_SYSTEM compat_syscall_exit_pointers |
| 251 | #define TRACE_INCLUDE_FILE compat_syscalls_pointers |
| 252 | #include <instrumentation/syscalls/headers/compat_syscalls_pointers.h> |
| 253 | #undef TRACE_INCLUDE_FILE |
| 254 | #undef TRACE_SYSTEM |
| 255 | #undef SC_LTTNG_TRACEPOINT_ENUM |
| 256 | #undef SC_LTTNG_TRACEPOINT_EVENT_CODE |
| 257 | #undef SC_LTTNG_TRACEPOINT_EVENT |
| 258 | #undef SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS |
| 259 | #undef SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS |
| 260 | #undef TP_PROBE_CB |
| 261 | #undef _TRACE_SYSCALLS_INTEGERS_H |
| 262 | #undef _TRACE_SYSCALLS_POINTERS_H |
| 263 | #undef LTTNG_SC_COMPAT |
| 264 | |
| 265 | #undef SC_EXIT |
| 266 | |
| 267 | #undef TP_MODULE_NOINIT |
| 268 | #undef LTTNG_PACKAGE_BUILD |
| 269 | #undef CREATE_TRACE_POINTS |
| 270 | |
| 271 | struct trace_syscall_entry { |
| 272 | void *func; |
| 273 | const struct lttng_event_desc *desc; |
| 274 | const struct lttng_event_field *fields; |
| 275 | unsigned int nrargs; |
| 276 | }; |
| 277 | |
| 278 | #define CREATE_SYSCALL_TABLE |
| 279 | |
| 280 | #define SC_ENTER |
| 281 | |
| 282 | #undef sc_exit |
| 283 | #define sc_exit(...) |
| 284 | |
| 285 | #undef TRACE_SYSCALL_TABLE |
| 286 | #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \ |
| 287 | [ _nr ] = { \ |
| 288 | .func = __event_probe__syscall_entry_##_template, \ |
| 289 | .nrargs = (_nrargs), \ |
| 290 | .fields = __event_fields___syscall_entry_##_template, \ |
| 291 | .desc = &__event_desc___syscall_entry_##_name, \ |
| 292 | }, |
| 293 | |
| 294 | /* Syscall enter tracing table */ |
| 295 | static const struct trace_syscall_entry sc_table[] = { |
| 296 | #include <instrumentation/syscalls/headers/syscalls_integers.h> |
| 297 | #include <instrumentation/syscalls/headers/syscalls_pointers.h> |
| 298 | }; |
| 299 | |
| 300 | #undef TRACE_SYSCALL_TABLE |
| 301 | #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \ |
| 302 | [ _nr ] = { \ |
| 303 | .func = __event_probe__compat_syscall_entry_##_template, \ |
| 304 | .nrargs = (_nrargs), \ |
| 305 | .fields = __event_fields___compat_syscall_entry_##_template, \ |
| 306 | .desc = &__event_desc___compat_syscall_entry_##_name, \ |
| 307 | }, |
| 308 | |
| 309 | /* Compat syscall enter table */ |
| 310 | const struct trace_syscall_entry compat_sc_table[] = { |
| 311 | #include <instrumentation/syscalls/headers/compat_syscalls_integers.h> |
| 312 | #include <instrumentation/syscalls/headers/compat_syscalls_pointers.h> |
| 313 | }; |
| 314 | |
| 315 | #undef SC_ENTER |
| 316 | |
| 317 | #define SC_EXIT |
| 318 | |
| 319 | #undef sc_exit |
| 320 | #define sc_exit(...) __VA_ARGS__ |
| 321 | |
| 322 | #undef TRACE_SYSCALL_TABLE |
| 323 | #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \ |
| 324 | [ _nr ] = { \ |
| 325 | .func = __event_probe__syscall_exit_##_template, \ |
| 326 | .nrargs = (_nrargs), \ |
| 327 | .fields = __event_fields___syscall_exit_##_template, \ |
| 328 | .desc = &__event_desc___syscall_exit_##_name, \ |
| 329 | }, |
| 330 | |
| 331 | /* Syscall exit table */ |
| 332 | static const struct trace_syscall_entry sc_exit_table[] = { |
| 333 | #include <instrumentation/syscalls/headers/syscalls_integers.h> |
| 334 | #include <instrumentation/syscalls/headers/syscalls_pointers.h> |
| 335 | }; |
| 336 | |
| 337 | #undef TRACE_SYSCALL_TABLE |
| 338 | #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \ |
| 339 | [ _nr ] = { \ |
| 340 | .func = __event_probe__compat_syscall_exit_##_template, \ |
| 341 | .nrargs = (_nrargs), \ |
| 342 | .fields = __event_fields___compat_syscall_exit_##_template, \ |
| 343 | .desc = &__event_desc___compat_syscall_exit_##_name, \ |
| 344 | }, |
| 345 | |
| 346 | /* Compat syscall exit table */ |
| 347 | const struct trace_syscall_entry compat_sc_exit_table[] = { |
| 348 | #include <instrumentation/syscalls/headers/compat_syscalls_integers.h> |
| 349 | #include <instrumentation/syscalls/headers/compat_syscalls_pointers.h> |
| 350 | }; |
| 351 | |
| 352 | #undef SC_EXIT |
| 353 | |
| 354 | #undef CREATE_SYSCALL_TABLE |
| 355 | |
| 356 | struct lttng_syscall_filter { |
| 357 | DECLARE_BITMAP(sc, NR_syscalls); |
| 358 | DECLARE_BITMAP(sc_compat, NR_compat_syscalls); |
| 359 | }; |
| 360 | |
| 361 | static void syscall_entry_unknown(struct lttng_event *event, |
| 362 | struct pt_regs *regs, unsigned int id) |
| 363 | { |
| 364 | unsigned long args[UNKNOWN_SYSCALL_NRARGS]; |
| 365 | |
| 366 | syscall_get_arguments(current, regs, 0, UNKNOWN_SYSCALL_NRARGS, args); |
| 367 | if (unlikely(in_compat_syscall())) |
| 368 | __event_probe__compat_syscall_entry_unknown(event, id, args); |
| 369 | else |
| 370 | __event_probe__syscall_entry_unknown(event, id, args); |
| 371 | } |
| 372 | |
| 373 | void syscall_entry_probe(void *__data, struct pt_regs *regs, long id) |
| 374 | { |
| 375 | struct lttng_channel *chan = __data; |
| 376 | struct lttng_event *event, *unknown_event; |
| 377 | const struct trace_syscall_entry *table, *entry; |
| 378 | size_t table_len; |
| 379 | |
| 380 | if (unlikely(in_compat_syscall())) { |
| 381 | struct lttng_syscall_filter *filter; |
| 382 | |
| 383 | filter = lttng_rcu_dereference(chan->sc_filter); |
| 384 | if (filter) { |
| 385 | if (id < 0 || id >= NR_compat_syscalls |
| 386 | || !test_bit(id, filter->sc_compat)) { |
| 387 | /* System call filtered out. */ |
| 388 | return; |
| 389 | } |
| 390 | } |
| 391 | table = compat_sc_table; |
| 392 | table_len = ARRAY_SIZE(compat_sc_table); |
| 393 | unknown_event = chan->sc_compat_unknown; |
| 394 | } else { |
| 395 | struct lttng_syscall_filter *filter; |
| 396 | |
| 397 | filter = lttng_rcu_dereference(chan->sc_filter); |
| 398 | if (filter) { |
| 399 | if (id < 0 || id >= NR_syscalls |
| 400 | || !test_bit(id, filter->sc)) { |
| 401 | /* System call filtered out. */ |
| 402 | return; |
| 403 | } |
| 404 | } |
| 405 | table = sc_table; |
| 406 | table_len = ARRAY_SIZE(sc_table); |
| 407 | unknown_event = chan->sc_unknown; |
| 408 | } |
| 409 | if (unlikely(id < 0 || id >= table_len)) { |
| 410 | syscall_entry_unknown(unknown_event, regs, id); |
| 411 | return; |
| 412 | } |
| 413 | if (unlikely(in_compat_syscall())) |
| 414 | event = chan->compat_sc_table[id]; |
| 415 | else |
| 416 | event = chan->sc_table[id]; |
| 417 | if (unlikely(!event)) { |
| 418 | syscall_entry_unknown(unknown_event, regs, id); |
| 419 | return; |
| 420 | } |
| 421 | entry = &table[id]; |
| 422 | WARN_ON_ONCE(!entry); |
| 423 | |
| 424 | switch (entry->nrargs) { |
| 425 | case 0: |
| 426 | { |
| 427 | void (*fptr)(void *__data) = entry->func; |
| 428 | |
| 429 | fptr(event); |
| 430 | break; |
| 431 | } |
| 432 | case 1: |
| 433 | { |
| 434 | void (*fptr)(void *__data, unsigned long arg0) = entry->func; |
| 435 | unsigned long args[1]; |
| 436 | |
| 437 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 438 | fptr(event, args[0]); |
| 439 | break; |
| 440 | } |
| 441 | case 2: |
| 442 | { |
| 443 | void (*fptr)(void *__data, |
| 444 | unsigned long arg0, |
| 445 | unsigned long arg1) = entry->func; |
| 446 | unsigned long args[2]; |
| 447 | |
| 448 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 449 | fptr(event, args[0], args[1]); |
| 450 | break; |
| 451 | } |
| 452 | case 3: |
| 453 | { |
| 454 | void (*fptr)(void *__data, |
| 455 | unsigned long arg0, |
| 456 | unsigned long arg1, |
| 457 | unsigned long arg2) = entry->func; |
| 458 | unsigned long args[3]; |
| 459 | |
| 460 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 461 | fptr(event, args[0], args[1], args[2]); |
| 462 | break; |
| 463 | } |
| 464 | case 4: |
| 465 | { |
| 466 | void (*fptr)(void *__data, |
| 467 | unsigned long arg0, |
| 468 | unsigned long arg1, |
| 469 | unsigned long arg2, |
| 470 | unsigned long arg3) = entry->func; |
| 471 | unsigned long args[4]; |
| 472 | |
| 473 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 474 | fptr(event, args[0], args[1], args[2], args[3]); |
| 475 | break; |
| 476 | } |
| 477 | case 5: |
| 478 | { |
| 479 | void (*fptr)(void *__data, |
| 480 | unsigned long arg0, |
| 481 | unsigned long arg1, |
| 482 | unsigned long arg2, |
| 483 | unsigned long arg3, |
| 484 | unsigned long arg4) = entry->func; |
| 485 | unsigned long args[5]; |
| 486 | |
| 487 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 488 | fptr(event, args[0], args[1], args[2], args[3], args[4]); |
| 489 | break; |
| 490 | } |
| 491 | case 6: |
| 492 | { |
| 493 | void (*fptr)(void *__data, |
| 494 | unsigned long arg0, |
| 495 | unsigned long arg1, |
| 496 | unsigned long arg2, |
| 497 | unsigned long arg3, |
| 498 | unsigned long arg4, |
| 499 | unsigned long arg5) = entry->func; |
| 500 | unsigned long args[6]; |
| 501 | |
| 502 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 503 | fptr(event, args[0], args[1], args[2], |
| 504 | args[3], args[4], args[5]); |
| 505 | break; |
| 506 | } |
| 507 | default: |
| 508 | break; |
| 509 | } |
| 510 | } |
| 511 | |
| 512 | static void syscall_exit_unknown(struct lttng_event *event, |
| 513 | struct pt_regs *regs, int id, long ret) |
| 514 | { |
| 515 | unsigned long args[UNKNOWN_SYSCALL_NRARGS]; |
| 516 | |
| 517 | syscall_get_arguments(current, regs, 0, UNKNOWN_SYSCALL_NRARGS, args); |
| 518 | if (unlikely(in_compat_syscall())) |
| 519 | __event_probe__compat_syscall_exit_unknown(event, id, ret, |
| 520 | args); |
| 521 | else |
| 522 | __event_probe__syscall_exit_unknown(event, id, ret, args); |
| 523 | } |
| 524 | |
| 525 | void syscall_exit_probe(void *__data, struct pt_regs *regs, long ret) |
| 526 | { |
| 527 | struct lttng_channel *chan = __data; |
| 528 | struct lttng_event *event, *unknown_event; |
| 529 | const struct trace_syscall_entry *table, *entry; |
| 530 | size_t table_len; |
| 531 | long id; |
| 532 | |
| 533 | id = syscall_get_nr(current, regs); |
| 534 | if (unlikely(in_compat_syscall())) { |
| 535 | struct lttng_syscall_filter *filter; |
| 536 | |
| 537 | filter = lttng_rcu_dereference(chan->sc_filter); |
| 538 | if (filter) { |
| 539 | if (id < 0 || id >= NR_compat_syscalls |
| 540 | || !test_bit(id, filter->sc_compat)) { |
| 541 | /* System call filtered out. */ |
| 542 | return; |
| 543 | } |
| 544 | } |
| 545 | table = compat_sc_exit_table; |
| 546 | table_len = ARRAY_SIZE(compat_sc_exit_table); |
| 547 | unknown_event = chan->compat_sc_exit_unknown; |
| 548 | } else { |
| 549 | struct lttng_syscall_filter *filter; |
| 550 | |
| 551 | filter = lttng_rcu_dereference(chan->sc_filter); |
| 552 | if (filter) { |
| 553 | if (id < 0 || id >= NR_syscalls |
| 554 | || !test_bit(id, filter->sc)) { |
| 555 | /* System call filtered out. */ |
| 556 | return; |
| 557 | } |
| 558 | } |
| 559 | table = sc_exit_table; |
| 560 | table_len = ARRAY_SIZE(sc_exit_table); |
| 561 | unknown_event = chan->sc_exit_unknown; |
| 562 | } |
| 563 | if (unlikely(id < 0 || id >= table_len)) { |
| 564 | syscall_exit_unknown(unknown_event, regs, id, ret); |
| 565 | return; |
| 566 | } |
| 567 | if (unlikely(in_compat_syscall())) |
| 568 | event = chan->compat_sc_exit_table[id]; |
| 569 | else |
| 570 | event = chan->sc_exit_table[id]; |
| 571 | if (unlikely(!event)) { |
| 572 | syscall_exit_unknown(unknown_event, regs, id, ret); |
| 573 | return; |
| 574 | } |
| 575 | entry = &table[id]; |
| 576 | WARN_ON_ONCE(!entry); |
| 577 | |
| 578 | switch (entry->nrargs) { |
| 579 | case 0: |
| 580 | { |
| 581 | void (*fptr)(void *__data, long ret) = entry->func; |
| 582 | |
| 583 | fptr(event, ret); |
| 584 | break; |
| 585 | } |
| 586 | case 1: |
| 587 | { |
| 588 | void (*fptr)(void *__data, |
| 589 | long ret, |
| 590 | unsigned long arg0) = entry->func; |
| 591 | unsigned long args[1]; |
| 592 | |
| 593 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 594 | fptr(event, ret, args[0]); |
| 595 | break; |
| 596 | } |
| 597 | case 2: |
| 598 | { |
| 599 | void (*fptr)(void *__data, |
| 600 | long ret, |
| 601 | unsigned long arg0, |
| 602 | unsigned long arg1) = entry->func; |
| 603 | unsigned long args[2]; |
| 604 | |
| 605 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 606 | fptr(event, ret, args[0], args[1]); |
| 607 | break; |
| 608 | } |
| 609 | case 3: |
| 610 | { |
| 611 | void (*fptr)(void *__data, |
| 612 | long ret, |
| 613 | unsigned long arg0, |
| 614 | unsigned long arg1, |
| 615 | unsigned long arg2) = entry->func; |
| 616 | unsigned long args[3]; |
| 617 | |
| 618 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 619 | fptr(event, ret, args[0], args[1], args[2]); |
| 620 | break; |
| 621 | } |
| 622 | case 4: |
| 623 | { |
| 624 | void (*fptr)(void *__data, |
| 625 | long ret, |
| 626 | unsigned long arg0, |
| 627 | unsigned long arg1, |
| 628 | unsigned long arg2, |
| 629 | unsigned long arg3) = entry->func; |
| 630 | unsigned long args[4]; |
| 631 | |
| 632 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 633 | fptr(event, ret, args[0], args[1], args[2], args[3]); |
| 634 | break; |
| 635 | } |
| 636 | case 5: |
| 637 | { |
| 638 | void (*fptr)(void *__data, |
| 639 | long ret, |
| 640 | unsigned long arg0, |
| 641 | unsigned long arg1, |
| 642 | unsigned long arg2, |
| 643 | unsigned long arg3, |
| 644 | unsigned long arg4) = entry->func; |
| 645 | unsigned long args[5]; |
| 646 | |
| 647 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 648 | fptr(event, ret, args[0], args[1], args[2], args[3], args[4]); |
| 649 | break; |
| 650 | } |
| 651 | case 6: |
| 652 | { |
| 653 | void (*fptr)(void *__data, |
| 654 | long ret, |
| 655 | unsigned long arg0, |
| 656 | unsigned long arg1, |
| 657 | unsigned long arg2, |
| 658 | unsigned long arg3, |
| 659 | unsigned long arg4, |
| 660 | unsigned long arg5) = entry->func; |
| 661 | unsigned long args[6]; |
| 662 | |
| 663 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 664 | fptr(event, ret, args[0], args[1], args[2], |
| 665 | args[3], args[4], args[5]); |
| 666 | break; |
| 667 | } |
| 668 | default: |
| 669 | break; |
| 670 | } |
| 671 | } |
| 672 | |
| 673 | /* |
| 674 | * noinline to diminish caller stack size. |
| 675 | * Should be called with sessions lock held. |
| 676 | */ |
| 677 | static |
| 678 | int fill_table(const struct trace_syscall_entry *table, size_t table_len, |
| 679 | struct lttng_event **chan_table, struct lttng_channel *chan, |
| 680 | void *filter, enum sc_type type) |
| 681 | { |
| 682 | const struct lttng_event_desc *desc; |
| 683 | unsigned int i; |
| 684 | |
| 685 | /* Allocate events for each syscall, insert into table */ |
| 686 | for (i = 0; i < table_len; i++) { |
| 687 | struct lttng_kernel_event ev; |
| 688 | desc = table[i].desc; |
| 689 | |
| 690 | if (!desc) { |
| 691 | /* Unknown syscall */ |
| 692 | continue; |
| 693 | } |
| 694 | /* |
| 695 | * Skip those already populated by previous failed |
| 696 | * register for this channel. |
| 697 | */ |
| 698 | if (chan_table[i]) |
| 699 | continue; |
| 700 | memset(&ev, 0, sizeof(ev)); |
| 701 | switch (type) { |
| 702 | case SC_TYPE_ENTRY: |
| 703 | strncpy(ev.name, SYSCALL_ENTRY_STR, |
| 704 | LTTNG_KERNEL_SYM_NAME_LEN); |
| 705 | break; |
| 706 | case SC_TYPE_EXIT: |
| 707 | strncpy(ev.name, SYSCALL_EXIT_STR, |
| 708 | LTTNG_KERNEL_SYM_NAME_LEN); |
| 709 | break; |
| 710 | case SC_TYPE_COMPAT_ENTRY: |
| 711 | strncpy(ev.name, COMPAT_SYSCALL_ENTRY_STR, |
| 712 | LTTNG_KERNEL_SYM_NAME_LEN); |
| 713 | break; |
| 714 | case SC_TYPE_COMPAT_EXIT: |
| 715 | strncpy(ev.name, COMPAT_SYSCALL_EXIT_STR, |
| 716 | LTTNG_KERNEL_SYM_NAME_LEN); |
| 717 | break; |
| 718 | default: |
| 719 | BUG_ON(1); |
| 720 | break; |
| 721 | } |
| 722 | strncat(ev.name, desc->name, |
| 723 | LTTNG_KERNEL_SYM_NAME_LEN - strlen(ev.name) - 1); |
| 724 | ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0'; |
| 725 | ev.instrumentation = LTTNG_KERNEL_SYSCALL; |
| 726 | chan_table[i] = _lttng_event_create(chan, &ev, filter, |
| 727 | desc, ev.instrumentation); |
| 728 | WARN_ON_ONCE(!chan_table[i]); |
| 729 | if (IS_ERR(chan_table[i])) { |
| 730 | /* |
| 731 | * If something goes wrong in event registration |
| 732 | * after the first one, we have no choice but to |
| 733 | * leave the previous events in there, until |
| 734 | * deleted by session teardown. |
| 735 | */ |
| 736 | return PTR_ERR(chan_table[i]); |
| 737 | } |
| 738 | } |
| 739 | return 0; |
| 740 | } |
| 741 | |
| 742 | /* |
| 743 | * Should be called with sessions lock held. |
| 744 | */ |
| 745 | int lttng_syscalls_register(struct lttng_channel *chan, void *filter) |
| 746 | { |
| 747 | struct lttng_kernel_event ev; |
| 748 | int ret; |
| 749 | |
| 750 | wrapper_vmalloc_sync_all(); |
| 751 | |
| 752 | if (!chan->sc_table) { |
| 753 | /* create syscall table mapping syscall to events */ |
| 754 | chan->sc_table = kzalloc(sizeof(struct lttng_event *) |
| 755 | * ARRAY_SIZE(sc_table), GFP_KERNEL); |
| 756 | if (!chan->sc_table) |
| 757 | return -ENOMEM; |
| 758 | } |
| 759 | if (!chan->sc_exit_table) { |
| 760 | /* create syscall table mapping syscall to events */ |
| 761 | chan->sc_exit_table = kzalloc(sizeof(struct lttng_event *) |
| 762 | * ARRAY_SIZE(sc_exit_table), GFP_KERNEL); |
| 763 | if (!chan->sc_exit_table) |
| 764 | return -ENOMEM; |
| 765 | } |
| 766 | |
| 767 | |
| 768 | #ifdef CONFIG_COMPAT |
| 769 | if (!chan->compat_sc_table) { |
| 770 | /* create syscall table mapping compat syscall to events */ |
| 771 | chan->compat_sc_table = kzalloc(sizeof(struct lttng_event *) |
| 772 | * ARRAY_SIZE(compat_sc_table), GFP_KERNEL); |
| 773 | if (!chan->compat_sc_table) |
| 774 | return -ENOMEM; |
| 775 | } |
| 776 | |
| 777 | if (!chan->compat_sc_exit_table) { |
| 778 | /* create syscall table mapping compat syscall to events */ |
| 779 | chan->compat_sc_exit_table = kzalloc(sizeof(struct lttng_event *) |
| 780 | * ARRAY_SIZE(compat_sc_exit_table), GFP_KERNEL); |
| 781 | if (!chan->compat_sc_exit_table) |
| 782 | return -ENOMEM; |
| 783 | } |
| 784 | #endif |
| 785 | if (!chan->sc_unknown) { |
| 786 | const struct lttng_event_desc *desc = |
| 787 | &__event_desc___syscall_entry_unknown; |
| 788 | |
| 789 | memset(&ev, 0, sizeof(ev)); |
| 790 | strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN); |
| 791 | ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0'; |
| 792 | ev.instrumentation = LTTNG_KERNEL_SYSCALL; |
| 793 | chan->sc_unknown = _lttng_event_create(chan, &ev, filter, |
| 794 | desc, |
| 795 | ev.instrumentation); |
| 796 | WARN_ON_ONCE(!chan->sc_unknown); |
| 797 | if (IS_ERR(chan->sc_unknown)) { |
| 798 | return PTR_ERR(chan->sc_unknown); |
| 799 | } |
| 800 | } |
| 801 | |
| 802 | if (!chan->sc_compat_unknown) { |
| 803 | const struct lttng_event_desc *desc = |
| 804 | &__event_desc___compat_syscall_entry_unknown; |
| 805 | |
| 806 | memset(&ev, 0, sizeof(ev)); |
| 807 | strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN); |
| 808 | ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0'; |
| 809 | ev.instrumentation = LTTNG_KERNEL_SYSCALL; |
| 810 | chan->sc_compat_unknown = _lttng_event_create(chan, &ev, filter, |
| 811 | desc, |
| 812 | ev.instrumentation); |
| 813 | WARN_ON_ONCE(!chan->sc_unknown); |
| 814 | if (IS_ERR(chan->sc_compat_unknown)) { |
| 815 | return PTR_ERR(chan->sc_compat_unknown); |
| 816 | } |
| 817 | } |
| 818 | |
| 819 | if (!chan->compat_sc_exit_unknown) { |
| 820 | const struct lttng_event_desc *desc = |
| 821 | &__event_desc___compat_syscall_exit_unknown; |
| 822 | |
| 823 | memset(&ev, 0, sizeof(ev)); |
| 824 | strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN); |
| 825 | ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0'; |
| 826 | ev.instrumentation = LTTNG_KERNEL_SYSCALL; |
| 827 | chan->compat_sc_exit_unknown = _lttng_event_create(chan, &ev, |
| 828 | filter, desc, |
| 829 | ev.instrumentation); |
| 830 | WARN_ON_ONCE(!chan->compat_sc_exit_unknown); |
| 831 | if (IS_ERR(chan->compat_sc_exit_unknown)) { |
| 832 | return PTR_ERR(chan->compat_sc_exit_unknown); |
| 833 | } |
| 834 | } |
| 835 | |
| 836 | if (!chan->sc_exit_unknown) { |
| 837 | const struct lttng_event_desc *desc = |
| 838 | &__event_desc___syscall_exit_unknown; |
| 839 | |
| 840 | memset(&ev, 0, sizeof(ev)); |
| 841 | strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN); |
| 842 | ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0'; |
| 843 | ev.instrumentation = LTTNG_KERNEL_SYSCALL; |
| 844 | chan->sc_exit_unknown = _lttng_event_create(chan, &ev, filter, |
| 845 | desc, ev.instrumentation); |
| 846 | WARN_ON_ONCE(!chan->sc_exit_unknown); |
| 847 | if (IS_ERR(chan->sc_exit_unknown)) { |
| 848 | return PTR_ERR(chan->sc_exit_unknown); |
| 849 | } |
| 850 | } |
| 851 | |
| 852 | ret = fill_table(sc_table, ARRAY_SIZE(sc_table), |
| 853 | chan->sc_table, chan, filter, SC_TYPE_ENTRY); |
| 854 | if (ret) |
| 855 | return ret; |
| 856 | ret = fill_table(sc_exit_table, ARRAY_SIZE(sc_exit_table), |
| 857 | chan->sc_exit_table, chan, filter, SC_TYPE_EXIT); |
| 858 | if (ret) |
| 859 | return ret; |
| 860 | |
| 861 | #ifdef CONFIG_COMPAT |
| 862 | ret = fill_table(compat_sc_table, ARRAY_SIZE(compat_sc_table), |
| 863 | chan->compat_sc_table, chan, filter, |
| 864 | SC_TYPE_COMPAT_ENTRY); |
| 865 | if (ret) |
| 866 | return ret; |
| 867 | ret = fill_table(compat_sc_exit_table, ARRAY_SIZE(compat_sc_exit_table), |
| 868 | chan->compat_sc_exit_table, chan, filter, |
| 869 | SC_TYPE_COMPAT_EXIT); |
| 870 | if (ret) |
| 871 | return ret; |
| 872 | #endif |
| 873 | if (!chan->sys_enter_registered) { |
| 874 | ret = lttng_wrapper_tracepoint_probe_register("sys_enter", |
| 875 | (void *) syscall_entry_probe, chan); |
| 876 | if (ret) |
| 877 | return ret; |
| 878 | chan->sys_enter_registered = 1; |
| 879 | } |
| 880 | /* |
| 881 | * We change the name of sys_exit tracepoint due to namespace |
| 882 | * conflict with sys_exit syscall entry. |
| 883 | */ |
| 884 | if (!chan->sys_exit_registered) { |
| 885 | ret = lttng_wrapper_tracepoint_probe_register("sys_exit", |
| 886 | (void *) syscall_exit_probe, chan); |
| 887 | if (ret) { |
| 888 | WARN_ON_ONCE(lttng_wrapper_tracepoint_probe_unregister("sys_enter", |
| 889 | (void *) syscall_entry_probe, chan)); |
| 890 | return ret; |
| 891 | } |
| 892 | chan->sys_exit_registered = 1; |
| 893 | } |
| 894 | return ret; |
| 895 | } |
| 896 | |
| 897 | /* |
| 898 | * Only called at session destruction. |
| 899 | */ |
| 900 | int lttng_syscalls_unregister(struct lttng_channel *chan) |
| 901 | { |
| 902 | int ret; |
| 903 | |
| 904 | if (!chan->sc_table) |
| 905 | return 0; |
| 906 | if (chan->sys_enter_registered) { |
| 907 | ret = lttng_wrapper_tracepoint_probe_unregister("sys_exit", |
| 908 | (void *) syscall_exit_probe, chan); |
| 909 | if (ret) |
| 910 | return ret; |
| 911 | chan->sys_enter_registered = 0; |
| 912 | } |
| 913 | if (chan->sys_exit_registered) { |
| 914 | ret = lttng_wrapper_tracepoint_probe_unregister("sys_enter", |
| 915 | (void *) syscall_entry_probe, chan); |
| 916 | if (ret) |
| 917 | return ret; |
| 918 | chan->sys_exit_registered = 0; |
| 919 | } |
| 920 | /* lttng_event destroy will be performed by lttng_session_destroy() */ |
| 921 | kfree(chan->sc_table); |
| 922 | kfree(chan->sc_exit_table); |
| 923 | #ifdef CONFIG_COMPAT |
| 924 | kfree(chan->compat_sc_table); |
| 925 | kfree(chan->compat_sc_exit_table); |
| 926 | #endif |
| 927 | kfree(chan->sc_filter); |
| 928 | return 0; |
| 929 | } |
| 930 | |
| 931 | static |
| 932 | int get_syscall_nr(const char *syscall_name) |
| 933 | { |
| 934 | int syscall_nr = -1; |
| 935 | int i; |
| 936 | |
| 937 | for (i = 0; i < ARRAY_SIZE(sc_table); i++) { |
| 938 | const struct trace_syscall_entry *entry; |
| 939 | const char *it_name; |
| 940 | |
| 941 | entry = &sc_table[i]; |
| 942 | if (!entry->desc) |
| 943 | continue; |
| 944 | it_name = entry->desc->name; |
| 945 | it_name += strlen(SYSCALL_ENTRY_STR); |
| 946 | if (!strcmp(syscall_name, it_name)) { |
| 947 | syscall_nr = i; |
| 948 | break; |
| 949 | } |
| 950 | } |
| 951 | return syscall_nr; |
| 952 | } |
| 953 | |
| 954 | static |
| 955 | int get_compat_syscall_nr(const char *syscall_name) |
| 956 | { |
| 957 | int syscall_nr = -1; |
| 958 | int i; |
| 959 | |
| 960 | for (i = 0; i < ARRAY_SIZE(compat_sc_table); i++) { |
| 961 | const struct trace_syscall_entry *entry; |
| 962 | const char *it_name; |
| 963 | |
| 964 | entry = &compat_sc_table[i]; |
| 965 | if (!entry->desc) |
| 966 | continue; |
| 967 | it_name = entry->desc->name; |
| 968 | it_name += strlen(COMPAT_SYSCALL_ENTRY_STR); |
| 969 | if (!strcmp(syscall_name, it_name)) { |
| 970 | syscall_nr = i; |
| 971 | break; |
| 972 | } |
| 973 | } |
| 974 | return syscall_nr; |
| 975 | } |
| 976 | |
| 977 | static |
| 978 | uint32_t get_sc_tables_len(void) |
| 979 | { |
| 980 | return ARRAY_SIZE(sc_table) + ARRAY_SIZE(compat_sc_table); |
| 981 | } |
| 982 | |
| 983 | int lttng_syscall_filter_enable(struct lttng_channel *chan, |
| 984 | const char *name) |
| 985 | { |
| 986 | int syscall_nr, compat_syscall_nr, ret; |
| 987 | struct lttng_syscall_filter *filter; |
| 988 | |
| 989 | WARN_ON_ONCE(!chan->sc_table); |
| 990 | |
| 991 | if (!name) { |
| 992 | /* Enable all system calls by removing filter */ |
| 993 | if (chan->sc_filter) { |
| 994 | filter = chan->sc_filter; |
| 995 | rcu_assign_pointer(chan->sc_filter, NULL); |
| 996 | synchronize_trace(); |
| 997 | kfree(filter); |
| 998 | } |
| 999 | chan->syscall_all = 1; |
| 1000 | return 0; |
| 1001 | } |
| 1002 | |
| 1003 | if (!chan->sc_filter) { |
| 1004 | if (chan->syscall_all) { |
| 1005 | /* |
| 1006 | * All syscalls are already enabled. |
| 1007 | */ |
| 1008 | return -EEXIST; |
| 1009 | } |
| 1010 | filter = kzalloc(sizeof(struct lttng_syscall_filter), |
| 1011 | GFP_KERNEL); |
| 1012 | if (!filter) |
| 1013 | return -ENOMEM; |
| 1014 | } else { |
| 1015 | filter = chan->sc_filter; |
| 1016 | } |
| 1017 | syscall_nr = get_syscall_nr(name); |
| 1018 | compat_syscall_nr = get_compat_syscall_nr(name); |
| 1019 | if (syscall_nr < 0 && compat_syscall_nr < 0) { |
| 1020 | ret = -ENOENT; |
| 1021 | goto error; |
| 1022 | } |
| 1023 | if (syscall_nr >= 0) { |
| 1024 | if (test_bit(syscall_nr, filter->sc)) { |
| 1025 | ret = -EEXIST; |
| 1026 | goto error; |
| 1027 | } |
| 1028 | bitmap_set(filter->sc, syscall_nr, 1); |
| 1029 | } |
| 1030 | if (compat_syscall_nr >= 0) { |
| 1031 | if (test_bit(compat_syscall_nr, filter->sc_compat)) { |
| 1032 | ret = -EEXIST; |
| 1033 | goto error; |
| 1034 | } |
| 1035 | bitmap_set(filter->sc_compat, compat_syscall_nr, 1); |
| 1036 | } |
| 1037 | if (!chan->sc_filter) |
| 1038 | rcu_assign_pointer(chan->sc_filter, filter); |
| 1039 | return 0; |
| 1040 | |
| 1041 | error: |
| 1042 | if (!chan->sc_filter) |
| 1043 | kfree(filter); |
| 1044 | return ret; |
| 1045 | } |
| 1046 | |
| 1047 | int lttng_syscall_filter_disable(struct lttng_channel *chan, |
| 1048 | const char *name) |
| 1049 | { |
| 1050 | int syscall_nr, compat_syscall_nr, ret; |
| 1051 | struct lttng_syscall_filter *filter; |
| 1052 | |
| 1053 | WARN_ON_ONCE(!chan->sc_table); |
| 1054 | |
| 1055 | if (!chan->sc_filter) { |
| 1056 | if (!chan->syscall_all) |
| 1057 | return -EEXIST; |
| 1058 | filter = kzalloc(sizeof(struct lttng_syscall_filter), |
| 1059 | GFP_KERNEL); |
| 1060 | if (!filter) |
| 1061 | return -ENOMEM; |
| 1062 | /* Trace all system calls, then apply disable. */ |
| 1063 | bitmap_set(filter->sc, 0, NR_syscalls); |
| 1064 | bitmap_set(filter->sc_compat, 0, NR_compat_syscalls); |
| 1065 | } else { |
| 1066 | filter = chan->sc_filter; |
| 1067 | } |
| 1068 | |
| 1069 | if (!name) { |
| 1070 | /* Fail if all syscalls are already disabled. */ |
| 1071 | if (bitmap_empty(filter->sc, NR_syscalls) |
| 1072 | && bitmap_empty(filter->sc_compat, |
| 1073 | NR_compat_syscalls)) { |
| 1074 | ret = -EEXIST; |
| 1075 | goto error; |
| 1076 | } |
| 1077 | |
| 1078 | /* Disable all system calls */ |
| 1079 | bitmap_clear(filter->sc, 0, NR_syscalls); |
| 1080 | bitmap_clear(filter->sc_compat, 0, NR_compat_syscalls); |
| 1081 | goto apply_filter; |
| 1082 | } |
| 1083 | syscall_nr = get_syscall_nr(name); |
| 1084 | compat_syscall_nr = get_compat_syscall_nr(name); |
| 1085 | if (syscall_nr < 0 && compat_syscall_nr < 0) { |
| 1086 | ret = -ENOENT; |
| 1087 | goto error; |
| 1088 | } |
| 1089 | if (syscall_nr >= 0) { |
| 1090 | if (!test_bit(syscall_nr, filter->sc)) { |
| 1091 | ret = -EEXIST; |
| 1092 | goto error; |
| 1093 | } |
| 1094 | bitmap_clear(filter->sc, syscall_nr, 1); |
| 1095 | } |
| 1096 | if (compat_syscall_nr >= 0) { |
| 1097 | if (!test_bit(compat_syscall_nr, filter->sc_compat)) { |
| 1098 | ret = -EEXIST; |
| 1099 | goto error; |
| 1100 | } |
| 1101 | bitmap_clear(filter->sc_compat, compat_syscall_nr, 1); |
| 1102 | } |
| 1103 | apply_filter: |
| 1104 | if (!chan->sc_filter) |
| 1105 | rcu_assign_pointer(chan->sc_filter, filter); |
| 1106 | chan->syscall_all = 0; |
| 1107 | return 0; |
| 1108 | |
| 1109 | error: |
| 1110 | if (!chan->sc_filter) |
| 1111 | kfree(filter); |
| 1112 | return ret; |
| 1113 | } |
| 1114 | |
| 1115 | static |
| 1116 | const struct trace_syscall_entry *syscall_list_get_entry(loff_t *pos) |
| 1117 | { |
| 1118 | const struct trace_syscall_entry *entry; |
| 1119 | int iter = 0; |
| 1120 | |
| 1121 | for (entry = sc_table; |
| 1122 | entry < sc_table + ARRAY_SIZE(sc_table); |
| 1123 | entry++) { |
| 1124 | if (iter++ >= *pos) |
| 1125 | return entry; |
| 1126 | } |
| 1127 | for (entry = compat_sc_table; |
| 1128 | entry < compat_sc_table + ARRAY_SIZE(compat_sc_table); |
| 1129 | entry++) { |
| 1130 | if (iter++ >= *pos) |
| 1131 | return entry; |
| 1132 | } |
| 1133 | /* End of list */ |
| 1134 | return NULL; |
| 1135 | } |
| 1136 | |
| 1137 | static |
| 1138 | void *syscall_list_start(struct seq_file *m, loff_t *pos) |
| 1139 | { |
| 1140 | return (void *) syscall_list_get_entry(pos); |
| 1141 | } |
| 1142 | |
| 1143 | static |
| 1144 | void *syscall_list_next(struct seq_file *m, void *p, loff_t *ppos) |
| 1145 | { |
| 1146 | (*ppos)++; |
| 1147 | return (void *) syscall_list_get_entry(ppos); |
| 1148 | } |
| 1149 | |
| 1150 | static |
| 1151 | void syscall_list_stop(struct seq_file *m, void *p) |
| 1152 | { |
| 1153 | } |
| 1154 | |
| 1155 | static |
| 1156 | int get_sc_table(const struct trace_syscall_entry *entry, |
| 1157 | const struct trace_syscall_entry **table, |
| 1158 | unsigned int *bitness) |
| 1159 | { |
| 1160 | if (entry >= sc_table && entry < sc_table + ARRAY_SIZE(sc_table)) { |
| 1161 | if (bitness) |
| 1162 | *bitness = BITS_PER_LONG; |
| 1163 | if (table) |
| 1164 | *table = sc_table; |
| 1165 | return 0; |
| 1166 | } |
| 1167 | if (!(entry >= compat_sc_table |
| 1168 | && entry < compat_sc_table + ARRAY_SIZE(compat_sc_table))) { |
| 1169 | return -EINVAL; |
| 1170 | } |
| 1171 | if (bitness) |
| 1172 | *bitness = 32; |
| 1173 | if (table) |
| 1174 | *table = compat_sc_table; |
| 1175 | return 0; |
| 1176 | } |
| 1177 | |
| 1178 | static |
| 1179 | int syscall_list_show(struct seq_file *m, void *p) |
| 1180 | { |
| 1181 | const struct trace_syscall_entry *table, *entry = p; |
| 1182 | unsigned int bitness; |
| 1183 | unsigned long index; |
| 1184 | int ret; |
| 1185 | const char *name; |
| 1186 | |
| 1187 | ret = get_sc_table(entry, &table, &bitness); |
| 1188 | if (ret) |
| 1189 | return ret; |
| 1190 | if (!entry->desc) |
| 1191 | return 0; |
| 1192 | if (table == sc_table) { |
| 1193 | index = entry - table; |
| 1194 | name = &entry->desc->name[strlen(SYSCALL_ENTRY_STR)]; |
| 1195 | } else { |
| 1196 | index = (entry - table) + ARRAY_SIZE(sc_table); |
| 1197 | name = &entry->desc->name[strlen(COMPAT_SYSCALL_ENTRY_STR)]; |
| 1198 | } |
| 1199 | seq_printf(m, "syscall { index = %lu; name = %s; bitness = %u; };\n", |
| 1200 | index, name, bitness); |
| 1201 | return 0; |
| 1202 | } |
| 1203 | |
| 1204 | static |
| 1205 | const struct seq_operations lttng_syscall_list_seq_ops = { |
| 1206 | .start = syscall_list_start, |
| 1207 | .next = syscall_list_next, |
| 1208 | .stop = syscall_list_stop, |
| 1209 | .show = syscall_list_show, |
| 1210 | }; |
| 1211 | |
| 1212 | static |
| 1213 | int lttng_syscall_list_open(struct inode *inode, struct file *file) |
| 1214 | { |
| 1215 | return seq_open(file, <tng_syscall_list_seq_ops); |
| 1216 | } |
| 1217 | |
| 1218 | const struct file_operations lttng_syscall_list_fops = { |
| 1219 | .owner = THIS_MODULE, |
| 1220 | .open = lttng_syscall_list_open, |
| 1221 | .read = seq_read, |
| 1222 | .llseek = seq_lseek, |
| 1223 | .release = seq_release, |
| 1224 | }; |
| 1225 | |
| 1226 | long lttng_channel_syscall_mask(struct lttng_channel *channel, |
| 1227 | struct lttng_kernel_syscall_mask __user *usyscall_mask) |
| 1228 | { |
| 1229 | uint32_t len, sc_tables_len, bitmask_len; |
| 1230 | int ret = 0, bit; |
| 1231 | char *tmp_mask; |
| 1232 | struct lttng_syscall_filter *filter; |
| 1233 | |
| 1234 | ret = get_user(len, &usyscall_mask->len); |
| 1235 | if (ret) |
| 1236 | return ret; |
| 1237 | sc_tables_len = get_sc_tables_len(); |
| 1238 | bitmask_len = ALIGN(sc_tables_len, 8) >> 3; |
| 1239 | if (len < sc_tables_len) { |
| 1240 | return put_user(sc_tables_len, &usyscall_mask->len); |
| 1241 | } |
| 1242 | /* Array is large enough, we can copy array to user-space. */ |
| 1243 | tmp_mask = kzalloc(bitmask_len, GFP_KERNEL); |
| 1244 | if (!tmp_mask) |
| 1245 | return -ENOMEM; |
| 1246 | filter = channel->sc_filter; |
| 1247 | |
| 1248 | for (bit = 0; bit < ARRAY_SIZE(sc_table); bit++) { |
| 1249 | char state; |
| 1250 | |
| 1251 | if (channel->sc_table) { |
| 1252 | if (filter) |
| 1253 | state = test_bit(bit, filter->sc); |
| 1254 | else |
| 1255 | state = 1; |
| 1256 | } else { |
| 1257 | state = 0; |
| 1258 | } |
| 1259 | bt_bitfield_write_be(tmp_mask, char, bit, 1, state); |
| 1260 | } |
| 1261 | for (; bit < sc_tables_len; bit++) { |
| 1262 | char state; |
| 1263 | |
| 1264 | if (channel->compat_sc_table) { |
| 1265 | if (filter) |
| 1266 | state = test_bit(bit - ARRAY_SIZE(sc_table), |
| 1267 | filter->sc_compat); |
| 1268 | else |
| 1269 | state = 1; |
| 1270 | } else { |
| 1271 | state = 0; |
| 1272 | } |
| 1273 | bt_bitfield_write_be(tmp_mask, char, bit, 1, state); |
| 1274 | } |
| 1275 | if (copy_to_user(usyscall_mask->mask, tmp_mask, bitmask_len)) |
| 1276 | ret = -EFAULT; |
| 1277 | kfree(tmp_mask); |
| 1278 | return ret; |
| 1279 | } |
| 1280 | |
| 1281 | int lttng_abi_syscall_list(void) |
| 1282 | { |
| 1283 | struct file *syscall_list_file; |
| 1284 | int file_fd, ret; |
| 1285 | |
| 1286 | file_fd = lttng_get_unused_fd(); |
| 1287 | if (file_fd < 0) { |
| 1288 | ret = file_fd; |
| 1289 | goto fd_error; |
| 1290 | } |
| 1291 | |
| 1292 | syscall_list_file = anon_inode_getfile("[lttng_syscall_list]", |
| 1293 | <tng_syscall_list_fops, |
| 1294 | NULL, O_RDWR); |
| 1295 | if (IS_ERR(syscall_list_file)) { |
| 1296 | ret = PTR_ERR(syscall_list_file); |
| 1297 | goto file_error; |
| 1298 | } |
| 1299 | ret = lttng_syscall_list_fops.open(NULL, syscall_list_file); |
| 1300 | if (ret < 0) |
| 1301 | goto open_error; |
| 1302 | fd_install(file_fd, syscall_list_file); |
| 1303 | return file_fd; |
| 1304 | |
| 1305 | open_error: |
| 1306 | fput(syscall_list_file); |
| 1307 | file_error: |
| 1308 | put_unused_fd(file_fd); |
| 1309 | fd_error: |
| 1310 | return ret; |
| 1311 | } |