| 1 | /* |
| 2 | * lttng-syscalls.c |
| 3 | * |
| 4 | * LTTng syscall probes. |
| 5 | * |
| 6 | * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 7 | * |
| 8 | * This library is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU Lesser General Public |
| 10 | * License as published by the Free Software Foundation; only |
| 11 | * version 2.1 of the License. |
| 12 | * |
| 13 | * This library is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 16 | * Lesser General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU Lesser General Public |
| 19 | * License along with this library; if not, write to the Free Software |
| 20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 21 | */ |
| 22 | |
| 23 | #include <linux/module.h> |
| 24 | #include <linux/slab.h> |
| 25 | #include <linux/compat.h> |
| 26 | #include <linux/err.h> |
| 27 | #include <linux/bitmap.h> |
| 28 | #include <linux/in.h> |
| 29 | #include <linux/in6.h> |
| 30 | #include <asm/ptrace.h> |
| 31 | #include <asm/syscall.h> |
| 32 | |
| 33 | #include "wrapper/tracepoint.h" |
| 34 | #include "lttng-events.h" |
| 35 | |
| 36 | #ifndef CONFIG_COMPAT |
| 37 | # ifndef is_compat_task |
| 38 | # define is_compat_task() (0) |
| 39 | # endif |
| 40 | #endif |
| 41 | |
| 42 | enum sc_type { |
| 43 | SC_TYPE_ENTRY, |
| 44 | SC_TYPE_EXIT, |
| 45 | SC_TYPE_COMPAT_ENTRY, |
| 46 | SC_TYPE_COMPAT_EXIT, |
| 47 | }; |
| 48 | |
| 49 | #define SYSCALL_ENTRY_STR "syscall_entry_" |
| 50 | #define COMPAT_SYSCALL_ENTRY_STR "compat_syscall_entry_" |
| 51 | #define SYSCALL_EXIT_STR "syscall_exit_" |
| 52 | #define COMPAT_SYSCALL_EXIT_STR "compat_syscall_exit_" |
| 53 | |
| 54 | static |
| 55 | void syscall_entry_probe(void *__data, struct pt_regs *regs, long id); |
| 56 | static |
| 57 | void syscall_exit_probe(void *__data, struct pt_regs *regs, long ret); |
| 58 | |
| 59 | /* |
| 60 | * Forward declarations for old kernels. |
| 61 | */ |
| 62 | struct mmsghdr; |
| 63 | struct rlimit64; |
| 64 | struct oldold_utsname; |
| 65 | struct old_utsname; |
| 66 | struct sel_arg_struct; |
| 67 | struct mmap_arg_struct; |
| 68 | |
| 69 | #ifdef IA32_NR_syscalls |
| 70 | #define NR_compat_syscalls IA32_NR_syscalls |
| 71 | #else |
| 72 | #define NR_compat_syscalls NR_syscalls |
| 73 | #endif |
| 74 | |
| 75 | /* |
| 76 | * Take care of NOARGS not supported by mainline. |
| 77 | */ |
| 78 | #define DECLARE_EVENT_CLASS_NOARGS(name, tstruct, assign, print) |
| 79 | #define DEFINE_EVENT_NOARGS(template, name) |
| 80 | #define TRACE_EVENT_NOARGS(name, struct, assign, print) |
| 81 | |
| 82 | /* |
| 83 | * Create LTTng tracepoint probes. |
| 84 | */ |
| 85 | #define LTTNG_PACKAGE_BUILD |
| 86 | #define CREATE_TRACE_POINTS |
| 87 | #define TP_MODULE_NOINIT |
| 88 | #define TRACE_INCLUDE_PATH ../instrumentation/syscalls/headers |
| 89 | |
| 90 | #define PARAMS(args...) args |
| 91 | |
| 92 | /* Handle unknown syscalls */ |
| 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_TRACE_EVENT(_name, _proto, _args, _struct, _assign, _printk) \ |
| 112 | TRACE_EVENT(syscall_enter_##_name, PARAMS(_proto), PARAMS(_args),\ |
| 113 | PARAMS(_struct), PARAMS(_assign), PARAMS(_printk)) |
| 114 | #define SC_LTTNG_TRACE_EVENT(_name, _proto, _args, _locvar, _code, _struct, _assign, _printk) \ |
| 115 | LTTNG_TRACE_EVENT(syscall_enter_##_name, PARAMS(_proto), PARAMS(_args),\ |
| 116 | PARAMS(_locvar), PARAMS(_code),\ |
| 117 | PARAMS(_struct), PARAMS(_assign), PARAMS(_printk)) |
| 118 | #define SC_DECLARE_EVENT_CLASS_NOARGS(_name, _struct, _assign, _printk) \ |
| 119 | DECLARE_EVENT_CLASS_NOARGS(syscall_enter_##_name, PARAMS(_struct), PARAMS(_assign),\ |
| 120 | PARAMS(_printk)) |
| 121 | #define SC_DEFINE_EVENT_NOARGS(_template, _name) \ |
| 122 | DEFINE_EVENT_NOARGS(syscall_enter_##_template, syscall_enter_##_name) |
| 123 | #undef TRACE_SYSTEM |
| 124 | #define TRACE_SYSTEM syscall_enter_integers |
| 125 | #define TRACE_INCLUDE_FILE syscalls_integers |
| 126 | #include "instrumentation/syscalls/headers/syscalls_integers.h" |
| 127 | #undef TRACE_INCLUDE_FILE |
| 128 | #undef TRACE_SYSTEM |
| 129 | #define TRACE_SYSTEM syscall_enter_pointers |
| 130 | #define TRACE_INCLUDE_FILE syscalls_pointers |
| 131 | #include "instrumentation/syscalls/headers/syscalls_pointers.h" |
| 132 | #undef TRACE_INCLUDE_FILE |
| 133 | #undef TRACE_SYSTEM |
| 134 | #undef SC_LTTNG_TRACE_EVENT |
| 135 | #undef SC_TRACE_EVENT |
| 136 | #undef SC_DECLARE_EVENT_CLASS_NOARGS |
| 137 | #undef SC_DEFINE_EVENT_NOARGS |
| 138 | #undef TP_PROBE_CB |
| 139 | #undef _TRACE_SYSCALLS_integers_H |
| 140 | #undef _TRACE_SYSCALLS_pointers_H |
| 141 | |
| 142 | |
| 143 | /* Hijack probe callback for compat system call enter */ |
| 144 | #define TP_PROBE_CB(_template) &syscall_entry_probe |
| 145 | #define SC_TRACE_EVENT(_name, _proto, _args, _struct, _assign, _printk) \ |
| 146 | TRACE_EVENT(compat_syscall_enter_##_name, PARAMS(_proto), PARAMS(_args), \ |
| 147 | PARAMS(_struct), PARAMS(_assign), \ |
| 148 | PARAMS(_printk)) |
| 149 | #define SC_LTTNG_TRACE_EVENT(_name, _proto, _args, _locvar, _code, _struct, _assign, _printk) \ |
| 150 | LTTNG_TRACE_EVENT(compat_syscall_enter_##_name, PARAMS(_proto), PARAMS(_args),\ |
| 151 | PARAMS(_locvar), PARAMS(_code),\ |
| 152 | PARAMS(_struct), PARAMS(_assign), PARAMS(_printk)) |
| 153 | #define SC_DECLARE_EVENT_CLASS_NOARGS(_name, _struct, _assign, _printk) \ |
| 154 | DECLARE_EVENT_CLASS_NOARGS(compat_syscall_enter_##_name, PARAMS(_struct), \ |
| 155 | PARAMS(_assign), PARAMS(_printk)) |
| 156 | #define SC_DEFINE_EVENT_NOARGS(_template, _name) \ |
| 157 | DEFINE_EVENT_NOARGS(compat_syscall_enter_##_template, \ |
| 158 | compat_syscall_enter_##_name) |
| 159 | #define TRACE_SYSTEM compat_syscall_enter_integers |
| 160 | #define TRACE_INCLUDE_FILE compat_syscalls_integers |
| 161 | #include "instrumentation/syscalls/headers/compat_syscalls_integers.h" |
| 162 | #undef TRACE_INCLUDE_FILE |
| 163 | #undef TRACE_SYSTEM |
| 164 | #define TRACE_SYSTEM compat_syscall_enter_pointers |
| 165 | #define TRACE_INCLUDE_FILE compat_syscalls_pointers |
| 166 | #include "instrumentation/syscalls/headers/compat_syscalls_pointers.h" |
| 167 | #undef TRACE_INCLUDE_FILE |
| 168 | #undef TRACE_SYSTEM |
| 169 | #undef SC_LTTNG_TRACE_EVENT |
| 170 | #undef SC_TRACE_EVENT |
| 171 | #undef SC_DECLARE_EVENT_CLASS_NOARGS |
| 172 | #undef SC_DEFINE_EVENT_NOARGS |
| 173 | #undef TP_PROBE_CB |
| 174 | #undef _TRACE_SYSCALLS_integers_H |
| 175 | #undef _TRACE_SYSCALLS_pointers_H |
| 176 | |
| 177 | #undef SC_ENTER |
| 178 | |
| 179 | #define SC_EXIT |
| 180 | |
| 181 | #undef sc_exit |
| 182 | #define sc_exit(...) __VA_ARGS__ |
| 183 | #undef sc_in |
| 184 | #define sc_in(...) |
| 185 | #undef sc_out |
| 186 | #define sc_out(...) __VA_ARGS__ |
| 187 | #undef sc_inout |
| 188 | #define sc_inout(...) __VA_ARGS__ |
| 189 | |
| 190 | /* Hijack probe callback for system call exit */ |
| 191 | #define TP_PROBE_CB(_template) &syscall_exit_probe |
| 192 | #define SC_TRACE_EVENT(_name, _proto, _args, _struct, _assign, _printk) \ |
| 193 | TRACE_EVENT(syscall_exit_##_name, PARAMS(_proto), PARAMS(_args),\ |
| 194 | PARAMS(_struct), PARAMS(_assign), PARAMS(_printk)) |
| 195 | #define SC_LTTNG_TRACE_EVENT(_name, _proto, _args, _locvar, _code, _struct, _assign, _printk) \ |
| 196 | LTTNG_TRACE_EVENT(syscall_exit_##_name, PARAMS(_proto), PARAMS(_args),\ |
| 197 | PARAMS(_locvar), PARAMS(_code),\ |
| 198 | PARAMS(_struct), PARAMS(_assign), PARAMS(_printk)) |
| 199 | #define SC_DECLARE_EVENT_CLASS_NOARGS(_name, _struct, _assign, _printk) \ |
| 200 | DECLARE_EVENT_CLASS_NOARGS(syscall_exit_##_name, PARAMS(_struct), \ |
| 201 | PARAMS(_assign), PARAMS(_printk)) |
| 202 | #define SC_DEFINE_EVENT_NOARGS(_template, _name) \ |
| 203 | DEFINE_EVENT_NOARGS(syscall_exit_##_template, \ |
| 204 | syscall_exit_##_name) |
| 205 | #define TRACE_SYSTEM syscall_exit_integers |
| 206 | #define TRACE_INCLUDE_FILE syscalls_integers |
| 207 | #include "instrumentation/syscalls/headers/syscalls_integers.h" |
| 208 | #undef TRACE_INCLUDE_FILE |
| 209 | #undef TRACE_SYSTEM |
| 210 | #define TRACE_SYSTEM syscall_exit_pointers |
| 211 | #define TRACE_INCLUDE_FILE syscalls_pointers |
| 212 | #include "instrumentation/syscalls/headers/syscalls_pointers.h" |
| 213 | #undef TRACE_INCLUDE_FILE |
| 214 | #undef TRACE_SYSTEM |
| 215 | #undef SC_LTTNG_TRACE_EVENT |
| 216 | #undef SC_TRACE_EVENT |
| 217 | #undef SC_DECLARE_EVENT_CLASS_NOARGS |
| 218 | #undef SC_DEFINE_EVENT_NOARGS |
| 219 | #undef TP_PROBE_CB |
| 220 | #undef _TRACE_SYSCALLS_integers_H |
| 221 | #undef _TRACE_SYSCALLS_pointers_H |
| 222 | |
| 223 | |
| 224 | /* Hijack probe callback for compat system call exit */ |
| 225 | #define TP_PROBE_CB(_template) &syscall_exit_probe |
| 226 | #define SC_TRACE_EVENT(_name, _proto, _args, _struct, _assign, _printk) \ |
| 227 | TRACE_EVENT(compat_syscall_exit_##_name, PARAMS(_proto), PARAMS(_args), \ |
| 228 | PARAMS(_struct), PARAMS(_assign), PARAMS(_printk)) |
| 229 | #define SC_LTTNG_TRACE_EVENT(_name, _proto, _args, _locvar, _code, _struct, _assign, _printk) \ |
| 230 | LTTNG_TRACE_EVENT(compat_syscall_exit_##_name, PARAMS(_proto), PARAMS(_args),\ |
| 231 | PARAMS(_locvar), PARAMS(_code),\ |
| 232 | PARAMS(_struct), PARAMS(_assign), PARAMS(_printk)) |
| 233 | #define SC_DECLARE_EVENT_CLASS_NOARGS(_name, _struct, _assign, _printk) \ |
| 234 | DECLARE_EVENT_CLASS_NOARGS(compat_syscall_exit_##_name, PARAMS(_struct), \ |
| 235 | PARAMS(_assign), PARAMS(_printk)) |
| 236 | #define SC_DEFINE_EVENT_NOARGS(_template, _name) \ |
| 237 | DEFINE_EVENT_NOARGS(compat_syscall_exit_##_template, \ |
| 238 | compat_syscall_exit_##_name) |
| 239 | #define TRACE_SYSTEM compat_syscall_exit_integers |
| 240 | #define TRACE_INCLUDE_FILE compat_syscalls_integers |
| 241 | #include "instrumentation/syscalls/headers/compat_syscalls_integers.h" |
| 242 | #undef TRACE_INCLUDE_FILE |
| 243 | #undef TRACE_SYSTEM |
| 244 | #define TRACE_SYSTEM compat_syscall_exit_pointers |
| 245 | #define TRACE_INCLUDE_FILE compat_syscalls_pointers |
| 246 | #include "instrumentation/syscalls/headers/compat_syscalls_pointers.h" |
| 247 | #undef TRACE_INCLUDE_FILE |
| 248 | #undef TRACE_SYSTEM |
| 249 | #undef SC_LTTNG_TRACE_EVENT |
| 250 | #undef SC_TRACE_EVENT |
| 251 | #undef SC_DECLARE_EVENT_CLASS_NOARGS |
| 252 | #undef SC_DEFINE_EVENT_NOARGS |
| 253 | #undef TP_PROBE_CB |
| 254 | #undef _TRACE_SYSCALLS_integers_H |
| 255 | #undef _TRACE_SYSCALLS_pointers_H |
| 256 | |
| 257 | #undef SC_EXIT |
| 258 | |
| 259 | #undef TP_MODULE_NOINIT |
| 260 | #undef LTTNG_PACKAGE_BUILD |
| 261 | #undef CREATE_TRACE_POINTS |
| 262 | |
| 263 | struct trace_syscall_entry { |
| 264 | void *func; |
| 265 | const struct lttng_event_desc *desc; |
| 266 | const struct lttng_event_field *fields; |
| 267 | unsigned int nrargs; |
| 268 | }; |
| 269 | |
| 270 | #define CREATE_SYSCALL_TABLE |
| 271 | |
| 272 | #define SC_ENTER |
| 273 | |
| 274 | #undef sc_exit |
| 275 | #define sc_exit(...) |
| 276 | |
| 277 | #undef TRACE_SYSCALL_TABLE |
| 278 | #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \ |
| 279 | [ _nr ] = { \ |
| 280 | .func = __event_probe__syscall_enter_##_template, \ |
| 281 | .nrargs = (_nrargs), \ |
| 282 | .fields = __event_fields___syscall_enter_##_template, \ |
| 283 | .desc = &__event_desc___syscall_enter_##_name, \ |
| 284 | }, |
| 285 | |
| 286 | /* Syscall enter tracing table */ |
| 287 | static const struct trace_syscall_entry sc_table[] = { |
| 288 | #include "instrumentation/syscalls/headers/syscalls_integers.h" |
| 289 | #include "instrumentation/syscalls/headers/syscalls_pointers.h" |
| 290 | }; |
| 291 | |
| 292 | #undef TRACE_SYSCALL_TABLE |
| 293 | #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \ |
| 294 | [ _nr ] = { \ |
| 295 | .func = __event_probe__compat_syscall_enter_##_template, \ |
| 296 | .nrargs = (_nrargs), \ |
| 297 | .fields = __event_fields___compat_syscall_enter_##_template, \ |
| 298 | .desc = &__event_desc___compat_syscall_enter_##_name, \ |
| 299 | }, |
| 300 | |
| 301 | /* Compat syscall enter table */ |
| 302 | const struct trace_syscall_entry compat_sc_table[] = { |
| 303 | #include "instrumentation/syscalls/headers/compat_syscalls_integers.h" |
| 304 | #include "instrumentation/syscalls/headers/compat_syscalls_pointers.h" |
| 305 | }; |
| 306 | |
| 307 | #undef SC_ENTER |
| 308 | |
| 309 | #define SC_EXIT |
| 310 | |
| 311 | #undef sc_exit |
| 312 | #define sc_exit(...) __VA_ARGS__ |
| 313 | |
| 314 | #undef TRACE_SYSCALL_TABLE |
| 315 | #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \ |
| 316 | [ _nr ] = { \ |
| 317 | .func = __event_probe__syscall_exit_##_template, \ |
| 318 | .nrargs = (_nrargs), \ |
| 319 | .fields = __event_fields___syscall_exit_##_template, \ |
| 320 | .desc = &__event_desc___syscall_exit_##_name, \ |
| 321 | }, |
| 322 | |
| 323 | /* Syscall exit table */ |
| 324 | static const struct trace_syscall_entry sc_exit_table[] = { |
| 325 | #include "instrumentation/syscalls/headers/syscalls_integers.h" |
| 326 | #include "instrumentation/syscalls/headers/syscalls_pointers.h" |
| 327 | }; |
| 328 | |
| 329 | #undef TRACE_SYSCALL_TABLE |
| 330 | #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \ |
| 331 | [ _nr ] = { \ |
| 332 | .func = __event_probe__compat_syscall_exit_##_template, \ |
| 333 | .nrargs = (_nrargs), \ |
| 334 | .fields = __event_fields___compat_syscall_exit_##_template, \ |
| 335 | .desc = &__event_desc___compat_syscall_exit_##_name, \ |
| 336 | }, |
| 337 | |
| 338 | /* Compat syscall exit table */ |
| 339 | const struct trace_syscall_entry compat_sc_exit_table[] = { |
| 340 | #include "instrumentation/syscalls/headers/compat_syscalls_integers.h" |
| 341 | #include "instrumentation/syscalls/headers/compat_syscalls_pointers.h" |
| 342 | }; |
| 343 | |
| 344 | #undef SC_EXIT |
| 345 | |
| 346 | #undef CREATE_SYSCALL_TABLE |
| 347 | |
| 348 | struct lttng_syscall_filter { |
| 349 | DECLARE_BITMAP(sc, NR_syscalls); |
| 350 | DECLARE_BITMAP(sc_compat, NR_compat_syscalls); |
| 351 | }; |
| 352 | |
| 353 | static void syscall_entry_unknown(struct lttng_event *event, |
| 354 | struct pt_regs *regs, unsigned int id) |
| 355 | { |
| 356 | unsigned long args[UNKNOWN_SYSCALL_NRARGS]; |
| 357 | |
| 358 | syscall_get_arguments(current, regs, 0, UNKNOWN_SYSCALL_NRARGS, args); |
| 359 | if (unlikely(is_compat_task())) |
| 360 | __event_probe__compat_syscall_enter_unknown(event, id, args); |
| 361 | else |
| 362 | __event_probe__syscall_enter_unknown(event, id, args); |
| 363 | } |
| 364 | |
| 365 | void syscall_entry_probe(void *__data, struct pt_regs *regs, long id) |
| 366 | { |
| 367 | struct lttng_channel *chan = __data; |
| 368 | struct lttng_event *event, *unknown_event; |
| 369 | const struct trace_syscall_entry *table, *entry; |
| 370 | size_t table_len; |
| 371 | |
| 372 | if (unlikely(is_compat_task())) { |
| 373 | struct lttng_syscall_filter *filter; |
| 374 | |
| 375 | filter = rcu_dereference(chan->sc_filter); |
| 376 | if (filter) { |
| 377 | if (id >= NR_compat_syscalls |
| 378 | || !test_bit(id, filter->sc_compat)) { |
| 379 | /* System call filtered out. */ |
| 380 | return; |
| 381 | } |
| 382 | } |
| 383 | table = compat_sc_table; |
| 384 | table_len = ARRAY_SIZE(compat_sc_table); |
| 385 | unknown_event = chan->sc_compat_unknown; |
| 386 | } else { |
| 387 | struct lttng_syscall_filter *filter; |
| 388 | |
| 389 | filter = rcu_dereference(chan->sc_filter); |
| 390 | if (filter) { |
| 391 | if (id >= NR_syscalls |
| 392 | || !test_bit(id, filter->sc)) { |
| 393 | /* System call filtered out. */ |
| 394 | return; |
| 395 | } |
| 396 | } |
| 397 | table = sc_table; |
| 398 | table_len = ARRAY_SIZE(sc_table); |
| 399 | unknown_event = chan->sc_unknown; |
| 400 | } |
| 401 | if (unlikely(id >= table_len)) { |
| 402 | syscall_entry_unknown(unknown_event, regs, id); |
| 403 | return; |
| 404 | } |
| 405 | if (unlikely(is_compat_task())) |
| 406 | event = chan->compat_sc_table[id]; |
| 407 | else |
| 408 | event = chan->sc_table[id]; |
| 409 | if (unlikely(!event)) { |
| 410 | syscall_entry_unknown(unknown_event, regs, id); |
| 411 | return; |
| 412 | } |
| 413 | entry = &table[id]; |
| 414 | WARN_ON_ONCE(!entry); |
| 415 | |
| 416 | switch (entry->nrargs) { |
| 417 | case 0: |
| 418 | { |
| 419 | void (*fptr)(void *__data) = entry->func; |
| 420 | |
| 421 | fptr(event); |
| 422 | break; |
| 423 | } |
| 424 | case 1: |
| 425 | { |
| 426 | void (*fptr)(void *__data, unsigned long arg0) = entry->func; |
| 427 | unsigned long args[1]; |
| 428 | |
| 429 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 430 | fptr(event, args[0]); |
| 431 | break; |
| 432 | } |
| 433 | case 2: |
| 434 | { |
| 435 | void (*fptr)(void *__data, |
| 436 | unsigned long arg0, |
| 437 | unsigned long arg1) = entry->func; |
| 438 | unsigned long args[2]; |
| 439 | |
| 440 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 441 | fptr(event, args[0], args[1]); |
| 442 | break; |
| 443 | } |
| 444 | case 3: |
| 445 | { |
| 446 | void (*fptr)(void *__data, |
| 447 | unsigned long arg0, |
| 448 | unsigned long arg1, |
| 449 | unsigned long arg2) = entry->func; |
| 450 | unsigned long args[3]; |
| 451 | |
| 452 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 453 | fptr(event, args[0], args[1], args[2]); |
| 454 | break; |
| 455 | } |
| 456 | case 4: |
| 457 | { |
| 458 | void (*fptr)(void *__data, |
| 459 | unsigned long arg0, |
| 460 | unsigned long arg1, |
| 461 | unsigned long arg2, |
| 462 | unsigned long arg3) = entry->func; |
| 463 | unsigned long args[4]; |
| 464 | |
| 465 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 466 | fptr(event, args[0], args[1], args[2], args[3]); |
| 467 | break; |
| 468 | } |
| 469 | case 5: |
| 470 | { |
| 471 | void (*fptr)(void *__data, |
| 472 | unsigned long arg0, |
| 473 | unsigned long arg1, |
| 474 | unsigned long arg2, |
| 475 | unsigned long arg3, |
| 476 | unsigned long arg4) = entry->func; |
| 477 | unsigned long args[5]; |
| 478 | |
| 479 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 480 | fptr(event, args[0], args[1], args[2], args[3], args[4]); |
| 481 | break; |
| 482 | } |
| 483 | case 6: |
| 484 | { |
| 485 | void (*fptr)(void *__data, |
| 486 | unsigned long arg0, |
| 487 | unsigned long arg1, |
| 488 | unsigned long arg2, |
| 489 | unsigned long arg3, |
| 490 | unsigned long arg4, |
| 491 | unsigned long arg5) = entry->func; |
| 492 | unsigned long args[6]; |
| 493 | |
| 494 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 495 | fptr(event, args[0], args[1], args[2], |
| 496 | args[3], args[4], args[5]); |
| 497 | break; |
| 498 | } |
| 499 | default: |
| 500 | break; |
| 501 | } |
| 502 | } |
| 503 | |
| 504 | static void syscall_exit_unknown(struct lttng_event *event, |
| 505 | struct pt_regs *regs, unsigned int id, long ret) |
| 506 | { |
| 507 | unsigned long args[UNKNOWN_SYSCALL_NRARGS]; |
| 508 | |
| 509 | syscall_get_arguments(current, regs, 0, UNKNOWN_SYSCALL_NRARGS, args); |
| 510 | if (unlikely(is_compat_task())) |
| 511 | __event_probe__compat_syscall_exit_unknown(event, id, ret, |
| 512 | args); |
| 513 | else |
| 514 | __event_probe__syscall_exit_unknown(event, id, ret, args); |
| 515 | } |
| 516 | |
| 517 | void syscall_exit_probe(void *__data, struct pt_regs *regs, long ret) |
| 518 | { |
| 519 | struct lttng_channel *chan = __data; |
| 520 | struct lttng_event *event, *unknown_event; |
| 521 | const struct trace_syscall_entry *table, *entry; |
| 522 | size_t table_len; |
| 523 | long id; |
| 524 | |
| 525 | id = syscall_get_nr(current, regs); |
| 526 | if (unlikely(is_compat_task())) { |
| 527 | struct lttng_syscall_filter *filter; |
| 528 | |
| 529 | filter = rcu_dereference(chan->sc_filter); |
| 530 | if (filter) { |
| 531 | if (id >= NR_compat_syscalls |
| 532 | || !test_bit(id, filter->sc_compat)) { |
| 533 | /* System call filtered out. */ |
| 534 | return; |
| 535 | } |
| 536 | } |
| 537 | table = compat_sc_exit_table; |
| 538 | table_len = ARRAY_SIZE(compat_sc_exit_table); |
| 539 | unknown_event = chan->compat_sc_exit_unknown; |
| 540 | } else { |
| 541 | struct lttng_syscall_filter *filter; |
| 542 | |
| 543 | filter = rcu_dereference(chan->sc_filter); |
| 544 | if (filter) { |
| 545 | if (id >= NR_syscalls |
| 546 | || !test_bit(id, filter->sc)) { |
| 547 | /* System call filtered out. */ |
| 548 | return; |
| 549 | } |
| 550 | } |
| 551 | table = sc_exit_table; |
| 552 | table_len = ARRAY_SIZE(sc_exit_table); |
| 553 | unknown_event = chan->sc_exit_unknown; |
| 554 | } |
| 555 | if (unlikely(id >= table_len)) { |
| 556 | syscall_exit_unknown(unknown_event, regs, id, ret); |
| 557 | return; |
| 558 | } |
| 559 | if (unlikely(is_compat_task())) |
| 560 | event = chan->compat_sc_exit_table[id]; |
| 561 | else |
| 562 | event = chan->sc_exit_table[id]; |
| 563 | if (unlikely(!event)) { |
| 564 | syscall_exit_unknown(unknown_event, regs, id, ret); |
| 565 | return; |
| 566 | } |
| 567 | entry = &table[id]; |
| 568 | WARN_ON_ONCE(!entry); |
| 569 | |
| 570 | switch (entry->nrargs) { |
| 571 | case 0: |
| 572 | { |
| 573 | void (*fptr)(void *__data, long ret) = entry->func; |
| 574 | |
| 575 | fptr(event, ret); |
| 576 | break; |
| 577 | } |
| 578 | case 1: |
| 579 | { |
| 580 | void (*fptr)(void *__data, |
| 581 | long ret, |
| 582 | unsigned long arg0) = entry->func; |
| 583 | unsigned long args[1]; |
| 584 | |
| 585 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 586 | fptr(event, ret, args[0]); |
| 587 | break; |
| 588 | } |
| 589 | case 2: |
| 590 | { |
| 591 | void (*fptr)(void *__data, |
| 592 | long ret, |
| 593 | unsigned long arg0, |
| 594 | unsigned long arg1) = entry->func; |
| 595 | unsigned long args[2]; |
| 596 | |
| 597 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 598 | fptr(event, ret, args[0], args[1]); |
| 599 | break; |
| 600 | } |
| 601 | case 3: |
| 602 | { |
| 603 | void (*fptr)(void *__data, |
| 604 | long ret, |
| 605 | unsigned long arg0, |
| 606 | unsigned long arg1, |
| 607 | unsigned long arg2) = entry->func; |
| 608 | unsigned long args[3]; |
| 609 | |
| 610 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 611 | fptr(event, ret, args[0], args[1], args[2]); |
| 612 | break; |
| 613 | } |
| 614 | case 4: |
| 615 | { |
| 616 | void (*fptr)(void *__data, |
| 617 | long ret, |
| 618 | unsigned long arg0, |
| 619 | unsigned long arg1, |
| 620 | unsigned long arg2, |
| 621 | unsigned long arg3) = entry->func; |
| 622 | unsigned long args[4]; |
| 623 | |
| 624 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 625 | fptr(event, ret, args[0], args[1], args[2], args[3]); |
| 626 | break; |
| 627 | } |
| 628 | case 5: |
| 629 | { |
| 630 | void (*fptr)(void *__data, |
| 631 | long ret, |
| 632 | unsigned long arg0, |
| 633 | unsigned long arg1, |
| 634 | unsigned long arg2, |
| 635 | unsigned long arg3, |
| 636 | unsigned long arg4) = entry->func; |
| 637 | unsigned long args[5]; |
| 638 | |
| 639 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 640 | fptr(event, ret, args[0], args[1], args[2], args[3], args[4]); |
| 641 | break; |
| 642 | } |
| 643 | case 6: |
| 644 | { |
| 645 | void (*fptr)(void *__data, |
| 646 | long ret, |
| 647 | unsigned long arg0, |
| 648 | unsigned long arg1, |
| 649 | unsigned long arg2, |
| 650 | unsigned long arg3, |
| 651 | unsigned long arg4, |
| 652 | unsigned long arg5) = entry->func; |
| 653 | unsigned long args[6]; |
| 654 | |
| 655 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 656 | fptr(event, ret, args[0], args[1], args[2], |
| 657 | args[3], args[4], args[5]); |
| 658 | break; |
| 659 | } |
| 660 | default: |
| 661 | break; |
| 662 | } |
| 663 | } |
| 664 | |
| 665 | /* noinline to diminish caller stack size */ |
| 666 | static |
| 667 | int fill_table(const struct trace_syscall_entry *table, size_t table_len, |
| 668 | struct lttng_event **chan_table, struct lttng_channel *chan, |
| 669 | void *filter, enum sc_type type) |
| 670 | { |
| 671 | const struct lttng_event_desc *desc; |
| 672 | unsigned int i; |
| 673 | |
| 674 | /* Allocate events for each syscall, insert into table */ |
| 675 | for (i = 0; i < table_len; i++) { |
| 676 | struct lttng_kernel_event ev; |
| 677 | desc = table[i].desc; |
| 678 | |
| 679 | if (!desc) { |
| 680 | /* Unknown syscall */ |
| 681 | continue; |
| 682 | } |
| 683 | /* |
| 684 | * Skip those already populated by previous failed |
| 685 | * register for this channel. |
| 686 | */ |
| 687 | if (chan_table[i]) |
| 688 | continue; |
| 689 | memset(&ev, 0, sizeof(ev)); |
| 690 | switch (type) { |
| 691 | case SC_TYPE_ENTRY: |
| 692 | strncpy(ev.name, SYSCALL_ENTRY_STR, |
| 693 | LTTNG_KERNEL_SYM_NAME_LEN); |
| 694 | break; |
| 695 | case SC_TYPE_EXIT: |
| 696 | strncpy(ev.name, SYSCALL_EXIT_STR, |
| 697 | LTTNG_KERNEL_SYM_NAME_LEN); |
| 698 | break; |
| 699 | case SC_TYPE_COMPAT_ENTRY: |
| 700 | strncpy(ev.name, COMPAT_SYSCALL_ENTRY_STR, |
| 701 | LTTNG_KERNEL_SYM_NAME_LEN); |
| 702 | break; |
| 703 | case SC_TYPE_COMPAT_EXIT: |
| 704 | strncpy(ev.name, COMPAT_SYSCALL_EXIT_STR, |
| 705 | LTTNG_KERNEL_SYM_NAME_LEN); |
| 706 | break; |
| 707 | default: |
| 708 | BUG_ON(1); |
| 709 | break; |
| 710 | } |
| 711 | strncat(ev.name, desc->name, |
| 712 | LTTNG_KERNEL_SYM_NAME_LEN - strlen(ev.name) - 1); |
| 713 | ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0'; |
| 714 | ev.instrumentation = LTTNG_KERNEL_NOOP; |
| 715 | chan_table[i] = lttng_event_create(chan, &ev, filter, |
| 716 | desc); |
| 717 | WARN_ON_ONCE(!chan_table[i]); |
| 718 | if (IS_ERR(chan_table[i])) { |
| 719 | /* |
| 720 | * If something goes wrong in event registration |
| 721 | * after the first one, we have no choice but to |
| 722 | * leave the previous events in there, until |
| 723 | * deleted by session teardown. |
| 724 | */ |
| 725 | return PTR_ERR(chan_table[i]); |
| 726 | } |
| 727 | } |
| 728 | return 0; |
| 729 | } |
| 730 | |
| 731 | int lttng_syscalls_register(struct lttng_channel *chan, void *filter) |
| 732 | { |
| 733 | struct lttng_kernel_event ev; |
| 734 | int ret; |
| 735 | |
| 736 | wrapper_vmalloc_sync_all(); |
| 737 | |
| 738 | if (!chan->sc_table) { |
| 739 | /* create syscall table mapping syscall to events */ |
| 740 | chan->sc_table = kzalloc(sizeof(struct lttng_event *) |
| 741 | * ARRAY_SIZE(sc_table), GFP_KERNEL); |
| 742 | if (!chan->sc_table) |
| 743 | return -ENOMEM; |
| 744 | } |
| 745 | if (!chan->sc_exit_table) { |
| 746 | /* create syscall table mapping syscall to events */ |
| 747 | chan->sc_exit_table = kzalloc(sizeof(struct lttng_event *) |
| 748 | * ARRAY_SIZE(sc_exit_table), GFP_KERNEL); |
| 749 | if (!chan->sc_exit_table) |
| 750 | return -ENOMEM; |
| 751 | } |
| 752 | |
| 753 | |
| 754 | #ifdef CONFIG_COMPAT |
| 755 | if (!chan->compat_sc_table) { |
| 756 | /* create syscall table mapping compat syscall to events */ |
| 757 | chan->compat_sc_table = kzalloc(sizeof(struct lttng_event *) |
| 758 | * ARRAY_SIZE(compat_sc_table), GFP_KERNEL); |
| 759 | if (!chan->compat_sc_table) |
| 760 | return -ENOMEM; |
| 761 | } |
| 762 | |
| 763 | if (!chan->compat_sc_exit_table) { |
| 764 | /* create syscall table mapping compat syscall to events */ |
| 765 | chan->compat_sc_exit_table = kzalloc(sizeof(struct lttng_event *) |
| 766 | * ARRAY_SIZE(compat_sc_exit_table), GFP_KERNEL); |
| 767 | if (!chan->compat_sc_exit_table) |
| 768 | return -ENOMEM; |
| 769 | } |
| 770 | #endif |
| 771 | if (!chan->sc_unknown) { |
| 772 | const struct lttng_event_desc *desc = |
| 773 | &__event_desc___syscall_enter_unknown; |
| 774 | |
| 775 | memset(&ev, 0, sizeof(ev)); |
| 776 | strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN); |
| 777 | ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0'; |
| 778 | ev.instrumentation = LTTNG_KERNEL_NOOP; |
| 779 | chan->sc_unknown = lttng_event_create(chan, &ev, filter, |
| 780 | desc); |
| 781 | WARN_ON_ONCE(!chan->sc_unknown); |
| 782 | if (IS_ERR(chan->sc_unknown)) { |
| 783 | return PTR_ERR(chan->sc_unknown); |
| 784 | } |
| 785 | } |
| 786 | |
| 787 | if (!chan->sc_compat_unknown) { |
| 788 | const struct lttng_event_desc *desc = |
| 789 | &__event_desc___compat_syscall_enter_unknown; |
| 790 | |
| 791 | memset(&ev, 0, sizeof(ev)); |
| 792 | strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN); |
| 793 | ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0'; |
| 794 | ev.instrumentation = LTTNG_KERNEL_NOOP; |
| 795 | chan->sc_compat_unknown = lttng_event_create(chan, &ev, filter, |
| 796 | desc); |
| 797 | WARN_ON_ONCE(!chan->sc_unknown); |
| 798 | if (IS_ERR(chan->sc_compat_unknown)) { |
| 799 | return PTR_ERR(chan->sc_compat_unknown); |
| 800 | } |
| 801 | } |
| 802 | |
| 803 | if (!chan->compat_sc_exit_unknown) { |
| 804 | const struct lttng_event_desc *desc = |
| 805 | &__event_desc___compat_syscall_exit_unknown; |
| 806 | |
| 807 | memset(&ev, 0, sizeof(ev)); |
| 808 | strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN); |
| 809 | ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0'; |
| 810 | ev.instrumentation = LTTNG_KERNEL_NOOP; |
| 811 | chan->compat_sc_exit_unknown = lttng_event_create(chan, &ev, |
| 812 | filter, desc); |
| 813 | WARN_ON_ONCE(!chan->compat_sc_exit_unknown); |
| 814 | if (IS_ERR(chan->compat_sc_exit_unknown)) { |
| 815 | return PTR_ERR(chan->compat_sc_exit_unknown); |
| 816 | } |
| 817 | } |
| 818 | |
| 819 | if (!chan->sc_exit_unknown) { |
| 820 | const struct lttng_event_desc *desc = |
| 821 | &__event_desc___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_NOOP; |
| 827 | chan->sc_exit_unknown = lttng_event_create(chan, &ev, filter, |
| 828 | desc); |
| 829 | WARN_ON_ONCE(!chan->sc_exit_unknown); |
| 830 | if (IS_ERR(chan->sc_exit_unknown)) { |
| 831 | return PTR_ERR(chan->sc_exit_unknown); |
| 832 | } |
| 833 | } |
| 834 | |
| 835 | ret = fill_table(sc_table, ARRAY_SIZE(sc_table), |
| 836 | chan->sc_table, chan, filter, SC_TYPE_ENTRY); |
| 837 | if (ret) |
| 838 | return ret; |
| 839 | ret = fill_table(sc_exit_table, ARRAY_SIZE(sc_exit_table), |
| 840 | chan->sc_exit_table, chan, filter, SC_TYPE_EXIT); |
| 841 | if (ret) |
| 842 | return ret; |
| 843 | |
| 844 | #ifdef CONFIG_COMPAT |
| 845 | ret = fill_table(compat_sc_table, ARRAY_SIZE(compat_sc_table), |
| 846 | chan->compat_sc_table, chan, filter, |
| 847 | SC_TYPE_COMPAT_ENTRY); |
| 848 | if (ret) |
| 849 | return ret; |
| 850 | ret = fill_table(compat_sc_exit_table, ARRAY_SIZE(compat_sc_exit_table), |
| 851 | chan->compat_sc_exit_table, chan, filter, |
| 852 | SC_TYPE_COMPAT_EXIT); |
| 853 | if (ret) |
| 854 | return ret; |
| 855 | #endif |
| 856 | if (!chan->sys_enter_registered) { |
| 857 | ret = lttng_wrapper_tracepoint_probe_register("sys_enter", |
| 858 | (void *) syscall_entry_probe, chan); |
| 859 | if (ret) |
| 860 | return ret; |
| 861 | chan->sys_enter_registered = 1; |
| 862 | } |
| 863 | /* |
| 864 | * We change the name of sys_exit tracepoint due to namespace |
| 865 | * conflict with sys_exit syscall entry. |
| 866 | */ |
| 867 | if (!chan->sys_exit_registered) { |
| 868 | ret = lttng_wrapper_tracepoint_probe_register("sys_exit", |
| 869 | (void *) syscall_exit_probe, chan); |
| 870 | if (ret) { |
| 871 | WARN_ON_ONCE(lttng_wrapper_tracepoint_probe_unregister("sys_enter", |
| 872 | (void *) syscall_entry_probe, chan)); |
| 873 | return ret; |
| 874 | } |
| 875 | chan->sys_exit_registered = 1; |
| 876 | } |
| 877 | return ret; |
| 878 | } |
| 879 | |
| 880 | /* |
| 881 | * Only called at session destruction. |
| 882 | */ |
| 883 | int lttng_syscalls_unregister(struct lttng_channel *chan) |
| 884 | { |
| 885 | int ret; |
| 886 | |
| 887 | if (!chan->sc_table) |
| 888 | return 0; |
| 889 | if (chan->sys_enter_registered) { |
| 890 | ret = lttng_wrapper_tracepoint_probe_unregister("sys_exit", |
| 891 | (void *) syscall_exit_probe, chan); |
| 892 | if (ret) |
| 893 | return ret; |
| 894 | chan->sys_enter_registered = 0; |
| 895 | } |
| 896 | if (chan->sys_exit_registered) { |
| 897 | ret = lttng_wrapper_tracepoint_probe_unregister("sys_enter", |
| 898 | (void *) syscall_entry_probe, chan); |
| 899 | if (ret) |
| 900 | return ret; |
| 901 | chan->sys_exit_registered = 0; |
| 902 | } |
| 903 | /* lttng_event destroy will be performed by lttng_session_destroy() */ |
| 904 | kfree(chan->sc_table); |
| 905 | kfree(chan->sc_exit_table); |
| 906 | #ifdef CONFIG_COMPAT |
| 907 | kfree(chan->compat_sc_table); |
| 908 | kfree(chan->compat_sc_exit_table); |
| 909 | #endif |
| 910 | kfree(chan->sc_filter); |
| 911 | return 0; |
| 912 | } |
| 913 | |
| 914 | static |
| 915 | int get_syscall_nr(const char *syscall_name) |
| 916 | { |
| 917 | int syscall_nr = -1; |
| 918 | int i; |
| 919 | |
| 920 | for (i = 0; i < ARRAY_SIZE(sc_table); i++) { |
| 921 | const struct trace_syscall_entry *entry; |
| 922 | const char *it_name; |
| 923 | |
| 924 | entry = &sc_table[i]; |
| 925 | if (!entry->desc) |
| 926 | continue; |
| 927 | it_name = entry->desc->name; |
| 928 | it_name += strlen(SYSCALL_ENTRY_STR); |
| 929 | if (!strcmp(syscall_name, it_name)) { |
| 930 | syscall_nr = i; |
| 931 | break; |
| 932 | } |
| 933 | } |
| 934 | return syscall_nr; |
| 935 | } |
| 936 | |
| 937 | static |
| 938 | int get_compat_syscall_nr(const char *syscall_name) |
| 939 | { |
| 940 | int syscall_nr = -1; |
| 941 | int i; |
| 942 | |
| 943 | for (i = 0; i < ARRAY_SIZE(compat_sc_table); i++) { |
| 944 | const struct trace_syscall_entry *entry; |
| 945 | const char *it_name; |
| 946 | |
| 947 | entry = &compat_sc_table[i]; |
| 948 | if (!entry->desc) |
| 949 | continue; |
| 950 | it_name = entry->desc->name; |
| 951 | it_name += strlen(COMPAT_SYSCALL_ENTRY_STR); |
| 952 | if (!strcmp(syscall_name, it_name)) { |
| 953 | syscall_nr = i; |
| 954 | break; |
| 955 | } |
| 956 | } |
| 957 | return syscall_nr; |
| 958 | } |
| 959 | |
| 960 | int lttng_syscall_filter_enable(struct lttng_channel *chan, |
| 961 | const char *name) |
| 962 | { |
| 963 | int syscall_nr, compat_syscall_nr, ret; |
| 964 | struct lttng_syscall_filter *filter; |
| 965 | |
| 966 | WARN_ON_ONCE(!chan->sc_table); |
| 967 | |
| 968 | if (!name) { |
| 969 | /* Enable all system calls by removing filter */ |
| 970 | if (chan->sc_filter) { |
| 971 | filter = chan->sc_filter; |
| 972 | rcu_assign_pointer(chan->sc_filter, NULL); |
| 973 | synchronize_trace(); |
| 974 | kfree(filter); |
| 975 | } |
| 976 | chan->syscall_all = 1; |
| 977 | return 0; |
| 978 | } |
| 979 | |
| 980 | if (!chan->sc_filter) { |
| 981 | if (chan->syscall_all) { |
| 982 | /* |
| 983 | * All syscalls are already enabled. |
| 984 | */ |
| 985 | return -EEXIST; |
| 986 | } |
| 987 | filter = kzalloc(sizeof(struct lttng_syscall_filter), |
| 988 | GFP_KERNEL); |
| 989 | if (!filter) |
| 990 | return -ENOMEM; |
| 991 | } else { |
| 992 | filter = chan->sc_filter; |
| 993 | } |
| 994 | syscall_nr = get_syscall_nr(name); |
| 995 | compat_syscall_nr = get_compat_syscall_nr(name); |
| 996 | if (syscall_nr < 0 && compat_syscall_nr < 0) { |
| 997 | ret = -ENOENT; |
| 998 | goto error; |
| 999 | } |
| 1000 | if (syscall_nr >= 0) { |
| 1001 | if (test_bit(syscall_nr, filter->sc)) { |
| 1002 | ret = -EEXIST; |
| 1003 | goto error; |
| 1004 | } |
| 1005 | bitmap_set(filter->sc, syscall_nr, 1); |
| 1006 | } |
| 1007 | if (compat_syscall_nr >= 0) { |
| 1008 | if (test_bit(compat_syscall_nr, filter->sc_compat)) { |
| 1009 | ret = -EEXIST; |
| 1010 | goto error; |
| 1011 | } |
| 1012 | bitmap_set(filter->sc_compat, compat_syscall_nr, 1); |
| 1013 | } |
| 1014 | if (!chan->sc_filter) |
| 1015 | rcu_assign_pointer(chan->sc_filter, filter); |
| 1016 | return 0; |
| 1017 | |
| 1018 | error: |
| 1019 | if (!chan->sc_filter) |
| 1020 | kfree(filter); |
| 1021 | return ret; |
| 1022 | } |
| 1023 | |
| 1024 | int lttng_syscall_filter_disable(struct lttng_channel *chan, |
| 1025 | const char *name) |
| 1026 | { |
| 1027 | int syscall_nr, compat_syscall_nr, ret; |
| 1028 | struct lttng_syscall_filter *filter; |
| 1029 | |
| 1030 | WARN_ON_ONCE(!chan->sc_table); |
| 1031 | |
| 1032 | if (!chan->sc_filter) { |
| 1033 | filter = kzalloc(sizeof(struct lttng_syscall_filter), |
| 1034 | GFP_KERNEL); |
| 1035 | if (!filter) |
| 1036 | return -ENOMEM; |
| 1037 | /* Trace all system calls, then apply disable. */ |
| 1038 | bitmap_set(filter->sc, 0, NR_syscalls); |
| 1039 | bitmap_set(filter->sc_compat, 0, NR_compat_syscalls); |
| 1040 | } else { |
| 1041 | filter = chan->sc_filter; |
| 1042 | } |
| 1043 | |
| 1044 | syscall_nr = get_syscall_nr(name); |
| 1045 | compat_syscall_nr = get_compat_syscall_nr(name); |
| 1046 | if (syscall_nr < 0 && compat_syscall_nr < 0) { |
| 1047 | ret = -ENOENT; |
| 1048 | goto error; |
| 1049 | } |
| 1050 | if (syscall_nr >= 0) { |
| 1051 | if (!test_bit(syscall_nr, chan->sc_filter->sc)) { |
| 1052 | ret = -EEXIST; |
| 1053 | goto error; |
| 1054 | } |
| 1055 | bitmap_clear(chan->sc_filter->sc, syscall_nr, 1); |
| 1056 | } |
| 1057 | if (compat_syscall_nr >= 0) { |
| 1058 | if (!test_bit(compat_syscall_nr, chan->sc_filter->sc_compat)) { |
| 1059 | ret = -EEXIST; |
| 1060 | goto error; |
| 1061 | } |
| 1062 | bitmap_clear(chan->sc_filter->sc_compat, compat_syscall_nr, 1); |
| 1063 | } |
| 1064 | if (!chan->sc_filter) |
| 1065 | rcu_assign_pointer(chan->sc_filter, filter); |
| 1066 | chan->syscall_all = 0; |
| 1067 | return 0; |
| 1068 | |
| 1069 | error: |
| 1070 | if (!chan->sc_filter) |
| 1071 | kfree(filter); |
| 1072 | return ret; |
| 1073 | } |