| 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 | * Create LTTng tracepoint probes. |
| 77 | */ |
| 78 | #define LTTNG_PACKAGE_BUILD |
| 79 | #define CREATE_TRACE_POINTS |
| 80 | #define TP_MODULE_NOINIT |
| 81 | #define TRACE_INCLUDE_PATH ../instrumentation/syscalls/headers |
| 82 | |
| 83 | #define PARAMS(args...) args |
| 84 | |
| 85 | /* Handle unknown syscalls */ |
| 86 | #define TRACE_SYSTEM syscalls_unknown |
| 87 | #include "instrumentation/syscalls/headers/syscalls_unknown.h" |
| 88 | #undef TRACE_SYSTEM |
| 89 | |
| 90 | #define SC_ENTER |
| 91 | |
| 92 | #undef sc_exit |
| 93 | #define sc_exit(...) |
| 94 | #undef sc_in |
| 95 | #define sc_in(...) __VA_ARGS__ |
| 96 | #undef sc_out |
| 97 | #define sc_out(...) |
| 98 | #undef sc_inout |
| 99 | #define sc_inout(...) __VA_ARGS__ |
| 100 | |
| 101 | /* Hijack probe callback for system call enter */ |
| 102 | #undef TP_PROBE_CB |
| 103 | #define TP_PROBE_CB(_template) &syscall_entry_probe |
| 104 | #define SC_LTTNG_TRACEPOINT_EVENT(_name, _proto, _args, _struct, _assign, _printk) \ |
| 105 | LTTNG_TRACEPOINT_EVENT(syscall_enter_##_name, PARAMS(_proto), PARAMS(_args), \ |
| 106 | PARAMS(_struct), PARAMS(_assign), PARAMS(_printk)) |
| 107 | #define SC_LTTNG_TRACEPOINT_EVENT_CODE(_name, _proto, _args, _locvar, _code, _struct, _assign, _printk) \ |
| 108 | LTTNG_TRACEPOINT_EVENT_CODE(syscall_enter_##_name, PARAMS(_proto), PARAMS(_args), \ |
| 109 | PARAMS(_locvar), PARAMS(_code), \ |
| 110 | PARAMS(_struct), PARAMS(_assign), PARAMS(_printk)) |
| 111 | #define SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(_name, _struct, _assign, _printk) \ |
| 112 | LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(syscall_enter_##_name, PARAMS(_struct), PARAMS(_assign), \ |
| 113 | PARAMS(_printk)) |
| 114 | #define SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(_template, _name) \ |
| 115 | LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(syscall_enter_##_template, syscall_enter_##_name) |
| 116 | #undef TRACE_SYSTEM |
| 117 | #define TRACE_SYSTEM syscall_enter_integers |
| 118 | #define TRACE_INCLUDE_FILE syscalls_integers |
| 119 | #include "instrumentation/syscalls/headers/syscalls_integers.h" |
| 120 | #undef TRACE_INCLUDE_FILE |
| 121 | #undef TRACE_SYSTEM |
| 122 | #define TRACE_SYSTEM syscall_enter_pointers |
| 123 | #define TRACE_INCLUDE_FILE syscalls_pointers |
| 124 | #include "instrumentation/syscalls/headers/syscalls_pointers.h" |
| 125 | #undef TRACE_INCLUDE_FILE |
| 126 | #undef TRACE_SYSTEM |
| 127 | #undef SC_LTTNG_TRACEPOINT_EVENT_CODE |
| 128 | #undef SC_LTTNG_TRACEPOINT_EVENT |
| 129 | #undef SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS |
| 130 | #undef SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS |
| 131 | #undef TP_PROBE_CB |
| 132 | #undef _TRACE_SYSCALLS_INTEGERS_H |
| 133 | #undef _TRACE_SYSCALLS_POINTERS_H |
| 134 | |
| 135 | /* Hijack probe callback for compat system call enter */ |
| 136 | #define TP_PROBE_CB(_template) &syscall_entry_probe |
| 137 | #define SC_LTTNG_TRACEPOINT_EVENT(_name, _proto, _args, _struct, _assign, _printk) \ |
| 138 | LTTNG_TRACEPOINT_EVENT(compat_syscall_enter_##_name, PARAMS(_proto), PARAMS(_args), \ |
| 139 | PARAMS(_struct), PARAMS(_assign), \ |
| 140 | PARAMS(_printk)) |
| 141 | #define SC_LTTNG_TRACEPOINT_EVENT_CODE(_name, _proto, _args, _locvar, _code, _struct, _assign, _printk) \ |
| 142 | LTTNG_TRACEPOINT_EVENT_CODE(compat_syscall_enter_##_name, PARAMS(_proto), PARAMS(_args), \ |
| 143 | PARAMS(_locvar), PARAMS(_code), \ |
| 144 | PARAMS(_struct), PARAMS(_assign), PARAMS(_printk)) |
| 145 | #define SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(_name, _struct, _assign, _printk) \ |
| 146 | LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(compat_syscall_enter_##_name, PARAMS(_struct), \ |
| 147 | PARAMS(_assign), PARAMS(_printk)) |
| 148 | #define SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(_template, _name) \ |
| 149 | LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(compat_syscall_enter_##_template, \ |
| 150 | compat_syscall_enter_##_name) |
| 151 | #define TRACE_SYSTEM compat_syscall_enter_integers |
| 152 | #define TRACE_INCLUDE_FILE compat_syscalls_integers |
| 153 | #include "instrumentation/syscalls/headers/compat_syscalls_integers.h" |
| 154 | #undef TRACE_INCLUDE_FILE |
| 155 | #undef TRACE_SYSTEM |
| 156 | #define TRACE_SYSTEM compat_syscall_enter_pointers |
| 157 | #define TRACE_INCLUDE_FILE compat_syscalls_pointers |
| 158 | #include "instrumentation/syscalls/headers/compat_syscalls_pointers.h" |
| 159 | #undef TRACE_INCLUDE_FILE |
| 160 | #undef TRACE_SYSTEM |
| 161 | #undef SC_LTTNG_TRACEPOINT_EVENT_CODE |
| 162 | #undef SC_LTTNG_TRACEPOINT_EVENT |
| 163 | #undef SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS |
| 164 | #undef SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS |
| 165 | #undef TP_PROBE_CB |
| 166 | #undef _TRACE_SYSCALLS_INTEGERS_H |
| 167 | #undef _TRACE_SYSCALLS_POINTERS_H |
| 168 | |
| 169 | #undef SC_ENTER |
| 170 | |
| 171 | #define SC_EXIT |
| 172 | |
| 173 | #undef sc_exit |
| 174 | #define sc_exit(...) __VA_ARGS__ |
| 175 | #undef sc_in |
| 176 | #define sc_in(...) |
| 177 | #undef sc_out |
| 178 | #define sc_out(...) __VA_ARGS__ |
| 179 | #undef sc_inout |
| 180 | #define sc_inout(...) __VA_ARGS__ |
| 181 | |
| 182 | /* Hijack probe callback for system call exit */ |
| 183 | #define TP_PROBE_CB(_template) &syscall_exit_probe |
| 184 | #define SC_LTTNG_TRACEPOINT_EVENT(_name, _proto, _args, _struct, _assign, _printk) \ |
| 185 | LTTNG_TRACEPOINT_EVENT(syscall_exit_##_name, PARAMS(_proto), PARAMS(_args), \ |
| 186 | PARAMS(_struct), PARAMS(_assign), PARAMS(_printk)) |
| 187 | #define SC_LTTNG_TRACEPOINT_EVENT_CODE(_name, _proto, _args, _locvar, _code, _struct, _assign, _printk) \ |
| 188 | LTTNG_TRACEPOINT_EVENT_CODE(syscall_exit_##_name, PARAMS(_proto), PARAMS(_args), \ |
| 189 | PARAMS(_locvar), PARAMS(_code), \ |
| 190 | PARAMS(_struct), PARAMS(_assign), PARAMS(_printk)) |
| 191 | #define SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(_name, _struct, _assign, _printk) \ |
| 192 | LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(syscall_exit_##_name, PARAMS(_struct), \ |
| 193 | PARAMS(_assign), PARAMS(_printk)) |
| 194 | #define SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(_template, _name) \ |
| 195 | LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(syscall_exit_##_template, \ |
| 196 | syscall_exit_##_name) |
| 197 | #define TRACE_SYSTEM syscall_exit_integers |
| 198 | #define TRACE_INCLUDE_FILE syscalls_integers |
| 199 | #include "instrumentation/syscalls/headers/syscalls_integers.h" |
| 200 | #undef TRACE_INCLUDE_FILE |
| 201 | #undef TRACE_SYSTEM |
| 202 | #define TRACE_SYSTEM syscall_exit_pointers |
| 203 | #define TRACE_INCLUDE_FILE syscalls_pointers |
| 204 | #include "instrumentation/syscalls/headers/syscalls_pointers.h" |
| 205 | #undef TRACE_INCLUDE_FILE |
| 206 | #undef TRACE_SYSTEM |
| 207 | #undef SC_LTTNG_TRACEPOINT_EVENT_CODE |
| 208 | #undef SC_LTTNG_TRACEPOINT_EVENT |
| 209 | #undef SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS |
| 210 | #undef SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS |
| 211 | #undef TP_PROBE_CB |
| 212 | #undef _TRACE_SYSCALLS_INTEGERS_H |
| 213 | #undef _TRACE_SYSCALLS_POINTERS_H |
| 214 | |
| 215 | |
| 216 | /* Hijack probe callback for compat system call exit */ |
| 217 | #define TP_PROBE_CB(_template) &syscall_exit_probe |
| 218 | #define SC_LTTNG_TRACEPOINT_EVENT(_name, _proto, _args, _struct, _assign, _printk) \ |
| 219 | LTTNG_TRACEPOINT_EVENT(compat_syscall_exit_##_name, PARAMS(_proto), PARAMS(_args), \ |
| 220 | PARAMS(_struct), PARAMS(_assign), PARAMS(_printk)) |
| 221 | #define SC_LTTNG_TRACEPOINT_EVENT_CODE(_name, _proto, _args, _locvar, _code, _struct, _assign, _printk) \ |
| 222 | LTTNG_TRACEPOINT_EVENT_CODE(compat_syscall_exit_##_name, PARAMS(_proto), PARAMS(_args), \ |
| 223 | PARAMS(_locvar), PARAMS(_code), \ |
| 224 | PARAMS(_struct), PARAMS(_assign), PARAMS(_printk)) |
| 225 | #define SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(_name, _struct, _assign, _printk) \ |
| 226 | LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS(compat_syscall_exit_##_name, PARAMS(_struct), \ |
| 227 | PARAMS(_assign), PARAMS(_printk)) |
| 228 | #define SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(_template, _name) \ |
| 229 | LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS(compat_syscall_exit_##_template, \ |
| 230 | compat_syscall_exit_##_name) |
| 231 | #define TRACE_SYSTEM compat_syscall_exit_integers |
| 232 | #define TRACE_INCLUDE_FILE compat_syscalls_integers |
| 233 | #include "instrumentation/syscalls/headers/compat_syscalls_integers.h" |
| 234 | #undef TRACE_INCLUDE_FILE |
| 235 | #undef TRACE_SYSTEM |
| 236 | #define TRACE_SYSTEM compat_syscall_exit_pointers |
| 237 | #define TRACE_INCLUDE_FILE compat_syscalls_pointers |
| 238 | #include "instrumentation/syscalls/headers/compat_syscalls_pointers.h" |
| 239 | #undef TRACE_INCLUDE_FILE |
| 240 | #undef TRACE_SYSTEM |
| 241 | #undef SC_LTTNG_TRACEPOINT_EVENT_CODE |
| 242 | #undef SC_LTTNG_TRACEPOINT_EVENT |
| 243 | #undef SC_LTTNG_TRACEPOINT_EVENT_CLASS_NOARGS |
| 244 | #undef SC_LTTNG_TRACEPOINT_EVENT_INSTANCE_NOARGS |
| 245 | #undef TP_PROBE_CB |
| 246 | #undef _TRACE_SYSCALLS_INTEGERS_H |
| 247 | #undef _TRACE_SYSCALLS_POINTERS_H |
| 248 | |
| 249 | #undef SC_EXIT |
| 250 | |
| 251 | #undef TP_MODULE_NOINIT |
| 252 | #undef LTTNG_PACKAGE_BUILD |
| 253 | #undef CREATE_TRACE_POINTS |
| 254 | |
| 255 | struct trace_syscall_entry { |
| 256 | void *func; |
| 257 | const struct lttng_event_desc *desc; |
| 258 | const struct lttng_event_field *fields; |
| 259 | unsigned int nrargs; |
| 260 | }; |
| 261 | |
| 262 | #define CREATE_SYSCALL_TABLE |
| 263 | |
| 264 | #define SC_ENTER |
| 265 | |
| 266 | #undef sc_exit |
| 267 | #define sc_exit(...) |
| 268 | |
| 269 | #undef TRACE_SYSCALL_TABLE |
| 270 | #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \ |
| 271 | [ _nr ] = { \ |
| 272 | .func = __event_probe__syscall_enter_##_template, \ |
| 273 | .nrargs = (_nrargs), \ |
| 274 | .fields = __event_fields___syscall_enter_##_template, \ |
| 275 | .desc = &__event_desc___syscall_enter_##_name, \ |
| 276 | }, |
| 277 | |
| 278 | /* Syscall enter tracing table */ |
| 279 | static const struct trace_syscall_entry sc_table[] = { |
| 280 | #include "instrumentation/syscalls/headers/syscalls_integers.h" |
| 281 | #include "instrumentation/syscalls/headers/syscalls_pointers.h" |
| 282 | }; |
| 283 | |
| 284 | #undef TRACE_SYSCALL_TABLE |
| 285 | #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \ |
| 286 | [ _nr ] = { \ |
| 287 | .func = __event_probe__compat_syscall_enter_##_template, \ |
| 288 | .nrargs = (_nrargs), \ |
| 289 | .fields = __event_fields___compat_syscall_enter_##_template, \ |
| 290 | .desc = &__event_desc___compat_syscall_enter_##_name, \ |
| 291 | }, |
| 292 | |
| 293 | /* Compat syscall enter table */ |
| 294 | const struct trace_syscall_entry compat_sc_table[] = { |
| 295 | #include "instrumentation/syscalls/headers/compat_syscalls_integers.h" |
| 296 | #include "instrumentation/syscalls/headers/compat_syscalls_pointers.h" |
| 297 | }; |
| 298 | |
| 299 | #undef SC_ENTER |
| 300 | |
| 301 | #define SC_EXIT |
| 302 | |
| 303 | #undef sc_exit |
| 304 | #define sc_exit(...) __VA_ARGS__ |
| 305 | |
| 306 | #undef TRACE_SYSCALL_TABLE |
| 307 | #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \ |
| 308 | [ _nr ] = { \ |
| 309 | .func = __event_probe__syscall_exit_##_template, \ |
| 310 | .nrargs = (_nrargs), \ |
| 311 | .fields = __event_fields___syscall_exit_##_template, \ |
| 312 | .desc = &__event_desc___syscall_exit_##_name, \ |
| 313 | }, |
| 314 | |
| 315 | /* Syscall exit table */ |
| 316 | static const struct trace_syscall_entry sc_exit_table[] = { |
| 317 | #include "instrumentation/syscalls/headers/syscalls_integers.h" |
| 318 | #include "instrumentation/syscalls/headers/syscalls_pointers.h" |
| 319 | }; |
| 320 | |
| 321 | #undef TRACE_SYSCALL_TABLE |
| 322 | #define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \ |
| 323 | [ _nr ] = { \ |
| 324 | .func = __event_probe__compat_syscall_exit_##_template, \ |
| 325 | .nrargs = (_nrargs), \ |
| 326 | .fields = __event_fields___compat_syscall_exit_##_template, \ |
| 327 | .desc = &__event_desc___compat_syscall_exit_##_name, \ |
| 328 | }, |
| 329 | |
| 330 | /* Compat syscall exit table */ |
| 331 | const struct trace_syscall_entry compat_sc_exit_table[] = { |
| 332 | #include "instrumentation/syscalls/headers/compat_syscalls_integers.h" |
| 333 | #include "instrumentation/syscalls/headers/compat_syscalls_pointers.h" |
| 334 | }; |
| 335 | |
| 336 | #undef SC_EXIT |
| 337 | |
| 338 | #undef CREATE_SYSCALL_TABLE |
| 339 | |
| 340 | struct lttng_syscall_filter { |
| 341 | DECLARE_BITMAP(sc, NR_syscalls); |
| 342 | DECLARE_BITMAP(sc_compat, NR_compat_syscalls); |
| 343 | }; |
| 344 | |
| 345 | static void syscall_entry_unknown(struct lttng_event *event, |
| 346 | struct pt_regs *regs, unsigned int id) |
| 347 | { |
| 348 | unsigned long args[UNKNOWN_SYSCALL_NRARGS]; |
| 349 | |
| 350 | syscall_get_arguments(current, regs, 0, UNKNOWN_SYSCALL_NRARGS, args); |
| 351 | if (unlikely(is_compat_task())) |
| 352 | __event_probe__compat_syscall_enter_unknown(event, id, args); |
| 353 | else |
| 354 | __event_probe__syscall_enter_unknown(event, id, args); |
| 355 | } |
| 356 | |
| 357 | void syscall_entry_probe(void *__data, struct pt_regs *regs, long id) |
| 358 | { |
| 359 | struct lttng_channel *chan = __data; |
| 360 | struct lttng_event *event, *unknown_event; |
| 361 | const struct trace_syscall_entry *table, *entry; |
| 362 | size_t table_len; |
| 363 | |
| 364 | if (unlikely(is_compat_task())) { |
| 365 | struct lttng_syscall_filter *filter; |
| 366 | |
| 367 | filter = rcu_dereference(chan->sc_filter); |
| 368 | if (filter) { |
| 369 | if (id >= NR_compat_syscalls |
| 370 | || !test_bit(id, filter->sc_compat)) { |
| 371 | /* System call filtered out. */ |
| 372 | return; |
| 373 | } |
| 374 | } |
| 375 | table = compat_sc_table; |
| 376 | table_len = ARRAY_SIZE(compat_sc_table); |
| 377 | unknown_event = chan->sc_compat_unknown; |
| 378 | } else { |
| 379 | struct lttng_syscall_filter *filter; |
| 380 | |
| 381 | filter = rcu_dereference(chan->sc_filter); |
| 382 | if (filter) { |
| 383 | if (id >= NR_syscalls |
| 384 | || !test_bit(id, filter->sc)) { |
| 385 | /* System call filtered out. */ |
| 386 | return; |
| 387 | } |
| 388 | } |
| 389 | table = sc_table; |
| 390 | table_len = ARRAY_SIZE(sc_table); |
| 391 | unknown_event = chan->sc_unknown; |
| 392 | } |
| 393 | if (unlikely(id >= table_len)) { |
| 394 | syscall_entry_unknown(unknown_event, regs, id); |
| 395 | return; |
| 396 | } |
| 397 | if (unlikely(is_compat_task())) |
| 398 | event = chan->compat_sc_table[id]; |
| 399 | else |
| 400 | event = chan->sc_table[id]; |
| 401 | if (unlikely(!event)) { |
| 402 | syscall_entry_unknown(unknown_event, regs, id); |
| 403 | return; |
| 404 | } |
| 405 | entry = &table[id]; |
| 406 | WARN_ON_ONCE(!entry); |
| 407 | |
| 408 | switch (entry->nrargs) { |
| 409 | case 0: |
| 410 | { |
| 411 | void (*fptr)(void *__data) = entry->func; |
| 412 | |
| 413 | fptr(event); |
| 414 | break; |
| 415 | } |
| 416 | case 1: |
| 417 | { |
| 418 | void (*fptr)(void *__data, unsigned long arg0) = entry->func; |
| 419 | unsigned long args[1]; |
| 420 | |
| 421 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 422 | fptr(event, args[0]); |
| 423 | break; |
| 424 | } |
| 425 | case 2: |
| 426 | { |
| 427 | void (*fptr)(void *__data, |
| 428 | unsigned long arg0, |
| 429 | unsigned long arg1) = entry->func; |
| 430 | unsigned long args[2]; |
| 431 | |
| 432 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 433 | fptr(event, args[0], args[1]); |
| 434 | break; |
| 435 | } |
| 436 | case 3: |
| 437 | { |
| 438 | void (*fptr)(void *__data, |
| 439 | unsigned long arg0, |
| 440 | unsigned long arg1, |
| 441 | unsigned long arg2) = entry->func; |
| 442 | unsigned long args[3]; |
| 443 | |
| 444 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 445 | fptr(event, args[0], args[1], args[2]); |
| 446 | break; |
| 447 | } |
| 448 | case 4: |
| 449 | { |
| 450 | void (*fptr)(void *__data, |
| 451 | unsigned long arg0, |
| 452 | unsigned long arg1, |
| 453 | unsigned long arg2, |
| 454 | unsigned long arg3) = entry->func; |
| 455 | unsigned long args[4]; |
| 456 | |
| 457 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 458 | fptr(event, args[0], args[1], args[2], args[3]); |
| 459 | break; |
| 460 | } |
| 461 | case 5: |
| 462 | { |
| 463 | void (*fptr)(void *__data, |
| 464 | unsigned long arg0, |
| 465 | unsigned long arg1, |
| 466 | unsigned long arg2, |
| 467 | unsigned long arg3, |
| 468 | unsigned long arg4) = entry->func; |
| 469 | unsigned long args[5]; |
| 470 | |
| 471 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 472 | fptr(event, args[0], args[1], args[2], args[3], args[4]); |
| 473 | break; |
| 474 | } |
| 475 | case 6: |
| 476 | { |
| 477 | void (*fptr)(void *__data, |
| 478 | unsigned long arg0, |
| 479 | unsigned long arg1, |
| 480 | unsigned long arg2, |
| 481 | unsigned long arg3, |
| 482 | unsigned long arg4, |
| 483 | unsigned long arg5) = entry->func; |
| 484 | unsigned long args[6]; |
| 485 | |
| 486 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 487 | fptr(event, args[0], args[1], args[2], |
| 488 | args[3], args[4], args[5]); |
| 489 | break; |
| 490 | } |
| 491 | default: |
| 492 | break; |
| 493 | } |
| 494 | } |
| 495 | |
| 496 | static void syscall_exit_unknown(struct lttng_event *event, |
| 497 | struct pt_regs *regs, unsigned int id, long ret) |
| 498 | { |
| 499 | unsigned long args[UNKNOWN_SYSCALL_NRARGS]; |
| 500 | |
| 501 | syscall_get_arguments(current, regs, 0, UNKNOWN_SYSCALL_NRARGS, args); |
| 502 | if (unlikely(is_compat_task())) |
| 503 | __event_probe__compat_syscall_exit_unknown(event, id, ret, |
| 504 | args); |
| 505 | else |
| 506 | __event_probe__syscall_exit_unknown(event, id, ret, args); |
| 507 | } |
| 508 | |
| 509 | void syscall_exit_probe(void *__data, struct pt_regs *regs, long ret) |
| 510 | { |
| 511 | struct lttng_channel *chan = __data; |
| 512 | struct lttng_event *event, *unknown_event; |
| 513 | const struct trace_syscall_entry *table, *entry; |
| 514 | size_t table_len; |
| 515 | long id; |
| 516 | |
| 517 | id = syscall_get_nr(current, regs); |
| 518 | if (unlikely(is_compat_task())) { |
| 519 | struct lttng_syscall_filter *filter; |
| 520 | |
| 521 | filter = rcu_dereference(chan->sc_filter); |
| 522 | if (filter) { |
| 523 | if (id >= NR_compat_syscalls |
| 524 | || !test_bit(id, filter->sc_compat)) { |
| 525 | /* System call filtered out. */ |
| 526 | return; |
| 527 | } |
| 528 | } |
| 529 | table = compat_sc_exit_table; |
| 530 | table_len = ARRAY_SIZE(compat_sc_exit_table); |
| 531 | unknown_event = chan->compat_sc_exit_unknown; |
| 532 | } else { |
| 533 | struct lttng_syscall_filter *filter; |
| 534 | |
| 535 | filter = rcu_dereference(chan->sc_filter); |
| 536 | if (filter) { |
| 537 | if (id >= NR_syscalls |
| 538 | || !test_bit(id, filter->sc)) { |
| 539 | /* System call filtered out. */ |
| 540 | return; |
| 541 | } |
| 542 | } |
| 543 | table = sc_exit_table; |
| 544 | table_len = ARRAY_SIZE(sc_exit_table); |
| 545 | unknown_event = chan->sc_exit_unknown; |
| 546 | } |
| 547 | if (unlikely(id >= table_len)) { |
| 548 | syscall_exit_unknown(unknown_event, regs, id, ret); |
| 549 | return; |
| 550 | } |
| 551 | if (unlikely(is_compat_task())) |
| 552 | event = chan->compat_sc_exit_table[id]; |
| 553 | else |
| 554 | event = chan->sc_exit_table[id]; |
| 555 | if (unlikely(!event)) { |
| 556 | syscall_exit_unknown(unknown_event, regs, id, ret); |
| 557 | return; |
| 558 | } |
| 559 | entry = &table[id]; |
| 560 | WARN_ON_ONCE(!entry); |
| 561 | |
| 562 | switch (entry->nrargs) { |
| 563 | case 0: |
| 564 | { |
| 565 | void (*fptr)(void *__data, long ret) = entry->func; |
| 566 | |
| 567 | fptr(event, ret); |
| 568 | break; |
| 569 | } |
| 570 | case 1: |
| 571 | { |
| 572 | void (*fptr)(void *__data, |
| 573 | long ret, |
| 574 | unsigned long arg0) = entry->func; |
| 575 | unsigned long args[1]; |
| 576 | |
| 577 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 578 | fptr(event, ret, args[0]); |
| 579 | break; |
| 580 | } |
| 581 | case 2: |
| 582 | { |
| 583 | void (*fptr)(void *__data, |
| 584 | long ret, |
| 585 | unsigned long arg0, |
| 586 | unsigned long arg1) = entry->func; |
| 587 | unsigned long args[2]; |
| 588 | |
| 589 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 590 | fptr(event, ret, args[0], args[1]); |
| 591 | break; |
| 592 | } |
| 593 | case 3: |
| 594 | { |
| 595 | void (*fptr)(void *__data, |
| 596 | long ret, |
| 597 | unsigned long arg0, |
| 598 | unsigned long arg1, |
| 599 | unsigned long arg2) = entry->func; |
| 600 | unsigned long args[3]; |
| 601 | |
| 602 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 603 | fptr(event, ret, args[0], args[1], args[2]); |
| 604 | break; |
| 605 | } |
| 606 | case 4: |
| 607 | { |
| 608 | void (*fptr)(void *__data, |
| 609 | long ret, |
| 610 | unsigned long arg0, |
| 611 | unsigned long arg1, |
| 612 | unsigned long arg2, |
| 613 | unsigned long arg3) = entry->func; |
| 614 | unsigned long args[4]; |
| 615 | |
| 616 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 617 | fptr(event, ret, args[0], args[1], args[2], args[3]); |
| 618 | break; |
| 619 | } |
| 620 | case 5: |
| 621 | { |
| 622 | void (*fptr)(void *__data, |
| 623 | long ret, |
| 624 | unsigned long arg0, |
| 625 | unsigned long arg1, |
| 626 | unsigned long arg2, |
| 627 | unsigned long arg3, |
| 628 | unsigned long arg4) = entry->func; |
| 629 | unsigned long args[5]; |
| 630 | |
| 631 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 632 | fptr(event, ret, args[0], args[1], args[2], args[3], args[4]); |
| 633 | break; |
| 634 | } |
| 635 | case 6: |
| 636 | { |
| 637 | void (*fptr)(void *__data, |
| 638 | long ret, |
| 639 | unsigned long arg0, |
| 640 | unsigned long arg1, |
| 641 | unsigned long arg2, |
| 642 | unsigned long arg3, |
| 643 | unsigned long arg4, |
| 644 | unsigned long arg5) = entry->func; |
| 645 | unsigned long args[6]; |
| 646 | |
| 647 | syscall_get_arguments(current, regs, 0, entry->nrargs, args); |
| 648 | fptr(event, ret, args[0], args[1], args[2], |
| 649 | args[3], args[4], args[5]); |
| 650 | break; |
| 651 | } |
| 652 | default: |
| 653 | break; |
| 654 | } |
| 655 | } |
| 656 | |
| 657 | /* noinline to diminish caller stack size */ |
| 658 | static |
| 659 | int fill_table(const struct trace_syscall_entry *table, size_t table_len, |
| 660 | struct lttng_event **chan_table, struct lttng_channel *chan, |
| 661 | void *filter, enum sc_type type) |
| 662 | { |
| 663 | const struct lttng_event_desc *desc; |
| 664 | unsigned int i; |
| 665 | |
| 666 | /* Allocate events for each syscall, insert into table */ |
| 667 | for (i = 0; i < table_len; i++) { |
| 668 | struct lttng_kernel_event ev; |
| 669 | desc = table[i].desc; |
| 670 | |
| 671 | if (!desc) { |
| 672 | /* Unknown syscall */ |
| 673 | continue; |
| 674 | } |
| 675 | /* |
| 676 | * Skip those already populated by previous failed |
| 677 | * register for this channel. |
| 678 | */ |
| 679 | if (chan_table[i]) |
| 680 | continue; |
| 681 | memset(&ev, 0, sizeof(ev)); |
| 682 | switch (type) { |
| 683 | case SC_TYPE_ENTRY: |
| 684 | strncpy(ev.name, SYSCALL_ENTRY_STR, |
| 685 | LTTNG_KERNEL_SYM_NAME_LEN); |
| 686 | break; |
| 687 | case SC_TYPE_EXIT: |
| 688 | strncpy(ev.name, SYSCALL_EXIT_STR, |
| 689 | LTTNG_KERNEL_SYM_NAME_LEN); |
| 690 | break; |
| 691 | case SC_TYPE_COMPAT_ENTRY: |
| 692 | strncpy(ev.name, COMPAT_SYSCALL_ENTRY_STR, |
| 693 | LTTNG_KERNEL_SYM_NAME_LEN); |
| 694 | break; |
| 695 | case SC_TYPE_COMPAT_EXIT: |
| 696 | strncpy(ev.name, COMPAT_SYSCALL_EXIT_STR, |
| 697 | LTTNG_KERNEL_SYM_NAME_LEN); |
| 698 | break; |
| 699 | default: |
| 700 | BUG_ON(1); |
| 701 | break; |
| 702 | } |
| 703 | strncat(ev.name, desc->name, |
| 704 | LTTNG_KERNEL_SYM_NAME_LEN - strlen(ev.name) - 1); |
| 705 | ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0'; |
| 706 | ev.instrumentation = LTTNG_KERNEL_NOOP; |
| 707 | chan_table[i] = lttng_event_create(chan, &ev, filter, |
| 708 | desc); |
| 709 | WARN_ON_ONCE(!chan_table[i]); |
| 710 | if (IS_ERR(chan_table[i])) { |
| 711 | /* |
| 712 | * If something goes wrong in event registration |
| 713 | * after the first one, we have no choice but to |
| 714 | * leave the previous events in there, until |
| 715 | * deleted by session teardown. |
| 716 | */ |
| 717 | return PTR_ERR(chan_table[i]); |
| 718 | } |
| 719 | } |
| 720 | return 0; |
| 721 | } |
| 722 | |
| 723 | int lttng_syscalls_register(struct lttng_channel *chan, void *filter) |
| 724 | { |
| 725 | struct lttng_kernel_event ev; |
| 726 | int ret; |
| 727 | |
| 728 | wrapper_vmalloc_sync_all(); |
| 729 | |
| 730 | if (!chan->sc_table) { |
| 731 | /* create syscall table mapping syscall to events */ |
| 732 | chan->sc_table = kzalloc(sizeof(struct lttng_event *) |
| 733 | * ARRAY_SIZE(sc_table), GFP_KERNEL); |
| 734 | if (!chan->sc_table) |
| 735 | return -ENOMEM; |
| 736 | } |
| 737 | if (!chan->sc_exit_table) { |
| 738 | /* create syscall table mapping syscall to events */ |
| 739 | chan->sc_exit_table = kzalloc(sizeof(struct lttng_event *) |
| 740 | * ARRAY_SIZE(sc_exit_table), GFP_KERNEL); |
| 741 | if (!chan->sc_exit_table) |
| 742 | return -ENOMEM; |
| 743 | } |
| 744 | |
| 745 | |
| 746 | #ifdef CONFIG_COMPAT |
| 747 | if (!chan->compat_sc_table) { |
| 748 | /* create syscall table mapping compat syscall to events */ |
| 749 | chan->compat_sc_table = kzalloc(sizeof(struct lttng_event *) |
| 750 | * ARRAY_SIZE(compat_sc_table), GFP_KERNEL); |
| 751 | if (!chan->compat_sc_table) |
| 752 | return -ENOMEM; |
| 753 | } |
| 754 | |
| 755 | if (!chan->compat_sc_exit_table) { |
| 756 | /* create syscall table mapping compat syscall to events */ |
| 757 | chan->compat_sc_exit_table = kzalloc(sizeof(struct lttng_event *) |
| 758 | * ARRAY_SIZE(compat_sc_exit_table), GFP_KERNEL); |
| 759 | if (!chan->compat_sc_exit_table) |
| 760 | return -ENOMEM; |
| 761 | } |
| 762 | #endif |
| 763 | if (!chan->sc_unknown) { |
| 764 | const struct lttng_event_desc *desc = |
| 765 | &__event_desc___syscall_enter_unknown; |
| 766 | |
| 767 | memset(&ev, 0, sizeof(ev)); |
| 768 | strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN); |
| 769 | ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0'; |
| 770 | ev.instrumentation = LTTNG_KERNEL_NOOP; |
| 771 | chan->sc_unknown = lttng_event_create(chan, &ev, filter, |
| 772 | desc); |
| 773 | WARN_ON_ONCE(!chan->sc_unknown); |
| 774 | if (IS_ERR(chan->sc_unknown)) { |
| 775 | return PTR_ERR(chan->sc_unknown); |
| 776 | } |
| 777 | } |
| 778 | |
| 779 | if (!chan->sc_compat_unknown) { |
| 780 | const struct lttng_event_desc *desc = |
| 781 | &__event_desc___compat_syscall_enter_unknown; |
| 782 | |
| 783 | memset(&ev, 0, sizeof(ev)); |
| 784 | strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN); |
| 785 | ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0'; |
| 786 | ev.instrumentation = LTTNG_KERNEL_NOOP; |
| 787 | chan->sc_compat_unknown = lttng_event_create(chan, &ev, filter, |
| 788 | desc); |
| 789 | WARN_ON_ONCE(!chan->sc_unknown); |
| 790 | if (IS_ERR(chan->sc_compat_unknown)) { |
| 791 | return PTR_ERR(chan->sc_compat_unknown); |
| 792 | } |
| 793 | } |
| 794 | |
| 795 | if (!chan->compat_sc_exit_unknown) { |
| 796 | const struct lttng_event_desc *desc = |
| 797 | &__event_desc___compat_syscall_exit_unknown; |
| 798 | |
| 799 | memset(&ev, 0, sizeof(ev)); |
| 800 | strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN); |
| 801 | ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0'; |
| 802 | ev.instrumentation = LTTNG_KERNEL_NOOP; |
| 803 | chan->compat_sc_exit_unknown = lttng_event_create(chan, &ev, |
| 804 | filter, desc); |
| 805 | WARN_ON_ONCE(!chan->compat_sc_exit_unknown); |
| 806 | if (IS_ERR(chan->compat_sc_exit_unknown)) { |
| 807 | return PTR_ERR(chan->compat_sc_exit_unknown); |
| 808 | } |
| 809 | } |
| 810 | |
| 811 | if (!chan->sc_exit_unknown) { |
| 812 | const struct lttng_event_desc *desc = |
| 813 | &__event_desc___syscall_exit_unknown; |
| 814 | |
| 815 | memset(&ev, 0, sizeof(ev)); |
| 816 | strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN); |
| 817 | ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0'; |
| 818 | ev.instrumentation = LTTNG_KERNEL_NOOP; |
| 819 | chan->sc_exit_unknown = lttng_event_create(chan, &ev, filter, |
| 820 | desc); |
| 821 | WARN_ON_ONCE(!chan->sc_exit_unknown); |
| 822 | if (IS_ERR(chan->sc_exit_unknown)) { |
| 823 | return PTR_ERR(chan->sc_exit_unknown); |
| 824 | } |
| 825 | } |
| 826 | |
| 827 | ret = fill_table(sc_table, ARRAY_SIZE(sc_table), |
| 828 | chan->sc_table, chan, filter, SC_TYPE_ENTRY); |
| 829 | if (ret) |
| 830 | return ret; |
| 831 | ret = fill_table(sc_exit_table, ARRAY_SIZE(sc_exit_table), |
| 832 | chan->sc_exit_table, chan, filter, SC_TYPE_EXIT); |
| 833 | if (ret) |
| 834 | return ret; |
| 835 | |
| 836 | #ifdef CONFIG_COMPAT |
| 837 | ret = fill_table(compat_sc_table, ARRAY_SIZE(compat_sc_table), |
| 838 | chan->compat_sc_table, chan, filter, |
| 839 | SC_TYPE_COMPAT_ENTRY); |
| 840 | if (ret) |
| 841 | return ret; |
| 842 | ret = fill_table(compat_sc_exit_table, ARRAY_SIZE(compat_sc_exit_table), |
| 843 | chan->compat_sc_exit_table, chan, filter, |
| 844 | SC_TYPE_COMPAT_EXIT); |
| 845 | if (ret) |
| 846 | return ret; |
| 847 | #endif |
| 848 | if (!chan->sys_enter_registered) { |
| 849 | ret = lttng_wrapper_tracepoint_probe_register("sys_enter", |
| 850 | (void *) syscall_entry_probe, chan); |
| 851 | if (ret) |
| 852 | return ret; |
| 853 | chan->sys_enter_registered = 1; |
| 854 | } |
| 855 | /* |
| 856 | * We change the name of sys_exit tracepoint due to namespace |
| 857 | * conflict with sys_exit syscall entry. |
| 858 | */ |
| 859 | if (!chan->sys_exit_registered) { |
| 860 | ret = lttng_wrapper_tracepoint_probe_register("sys_exit", |
| 861 | (void *) syscall_exit_probe, chan); |
| 862 | if (ret) { |
| 863 | WARN_ON_ONCE(lttng_wrapper_tracepoint_probe_unregister("sys_enter", |
| 864 | (void *) syscall_entry_probe, chan)); |
| 865 | return ret; |
| 866 | } |
| 867 | chan->sys_exit_registered = 1; |
| 868 | } |
| 869 | return ret; |
| 870 | } |
| 871 | |
| 872 | /* |
| 873 | * Only called at session destruction. |
| 874 | */ |
| 875 | int lttng_syscalls_unregister(struct lttng_channel *chan) |
| 876 | { |
| 877 | int ret; |
| 878 | |
| 879 | if (!chan->sc_table) |
| 880 | return 0; |
| 881 | if (chan->sys_enter_registered) { |
| 882 | ret = lttng_wrapper_tracepoint_probe_unregister("sys_exit", |
| 883 | (void *) syscall_exit_probe, chan); |
| 884 | if (ret) |
| 885 | return ret; |
| 886 | chan->sys_enter_registered = 0; |
| 887 | } |
| 888 | if (chan->sys_exit_registered) { |
| 889 | ret = lttng_wrapper_tracepoint_probe_unregister("sys_enter", |
| 890 | (void *) syscall_entry_probe, chan); |
| 891 | if (ret) |
| 892 | return ret; |
| 893 | chan->sys_exit_registered = 0; |
| 894 | } |
| 895 | /* lttng_event destroy will be performed by lttng_session_destroy() */ |
| 896 | kfree(chan->sc_table); |
| 897 | kfree(chan->sc_exit_table); |
| 898 | #ifdef CONFIG_COMPAT |
| 899 | kfree(chan->compat_sc_table); |
| 900 | kfree(chan->compat_sc_exit_table); |
| 901 | #endif |
| 902 | kfree(chan->sc_filter); |
| 903 | return 0; |
| 904 | } |
| 905 | |
| 906 | static |
| 907 | int get_syscall_nr(const char *syscall_name) |
| 908 | { |
| 909 | int syscall_nr = -1; |
| 910 | int i; |
| 911 | |
| 912 | for (i = 0; i < ARRAY_SIZE(sc_table); i++) { |
| 913 | const struct trace_syscall_entry *entry; |
| 914 | const char *it_name; |
| 915 | |
| 916 | entry = &sc_table[i]; |
| 917 | if (!entry->desc) |
| 918 | continue; |
| 919 | it_name = entry->desc->name; |
| 920 | it_name += strlen(SYSCALL_ENTRY_STR); |
| 921 | if (!strcmp(syscall_name, it_name)) { |
| 922 | syscall_nr = i; |
| 923 | break; |
| 924 | } |
| 925 | } |
| 926 | return syscall_nr; |
| 927 | } |
| 928 | |
| 929 | static |
| 930 | int get_compat_syscall_nr(const char *syscall_name) |
| 931 | { |
| 932 | int syscall_nr = -1; |
| 933 | int i; |
| 934 | |
| 935 | for (i = 0; i < ARRAY_SIZE(compat_sc_table); i++) { |
| 936 | const struct trace_syscall_entry *entry; |
| 937 | const char *it_name; |
| 938 | |
| 939 | entry = &compat_sc_table[i]; |
| 940 | if (!entry->desc) |
| 941 | continue; |
| 942 | it_name = entry->desc->name; |
| 943 | it_name += strlen(COMPAT_SYSCALL_ENTRY_STR); |
| 944 | if (!strcmp(syscall_name, it_name)) { |
| 945 | syscall_nr = i; |
| 946 | break; |
| 947 | } |
| 948 | } |
| 949 | return syscall_nr; |
| 950 | } |
| 951 | |
| 952 | int lttng_syscall_filter_enable(struct lttng_channel *chan, |
| 953 | const char *name) |
| 954 | { |
| 955 | int syscall_nr, compat_syscall_nr, ret; |
| 956 | struct lttng_syscall_filter *filter; |
| 957 | |
| 958 | WARN_ON_ONCE(!chan->sc_table); |
| 959 | |
| 960 | if (!name) { |
| 961 | /* Enable all system calls by removing filter */ |
| 962 | if (chan->sc_filter) { |
| 963 | filter = chan->sc_filter; |
| 964 | rcu_assign_pointer(chan->sc_filter, NULL); |
| 965 | synchronize_trace(); |
| 966 | kfree(filter); |
| 967 | } |
| 968 | chan->syscall_all = 1; |
| 969 | return 0; |
| 970 | } |
| 971 | |
| 972 | if (!chan->sc_filter) { |
| 973 | if (chan->syscall_all) { |
| 974 | /* |
| 975 | * All syscalls are already enabled. |
| 976 | */ |
| 977 | return -EEXIST; |
| 978 | } |
| 979 | filter = kzalloc(sizeof(struct lttng_syscall_filter), |
| 980 | GFP_KERNEL); |
| 981 | if (!filter) |
| 982 | return -ENOMEM; |
| 983 | } else { |
| 984 | filter = chan->sc_filter; |
| 985 | } |
| 986 | syscall_nr = get_syscall_nr(name); |
| 987 | compat_syscall_nr = get_compat_syscall_nr(name); |
| 988 | if (syscall_nr < 0 && compat_syscall_nr < 0) { |
| 989 | ret = -ENOENT; |
| 990 | goto error; |
| 991 | } |
| 992 | if (syscall_nr >= 0) { |
| 993 | if (test_bit(syscall_nr, filter->sc)) { |
| 994 | ret = -EEXIST; |
| 995 | goto error; |
| 996 | } |
| 997 | bitmap_set(filter->sc, syscall_nr, 1); |
| 998 | } |
| 999 | if (compat_syscall_nr >= 0) { |
| 1000 | if (test_bit(compat_syscall_nr, filter->sc_compat)) { |
| 1001 | ret = -EEXIST; |
| 1002 | goto error; |
| 1003 | } |
| 1004 | bitmap_set(filter->sc_compat, compat_syscall_nr, 1); |
| 1005 | } |
| 1006 | if (!chan->sc_filter) |
| 1007 | rcu_assign_pointer(chan->sc_filter, filter); |
| 1008 | return 0; |
| 1009 | |
| 1010 | error: |
| 1011 | if (!chan->sc_filter) |
| 1012 | kfree(filter); |
| 1013 | return ret; |
| 1014 | } |
| 1015 | |
| 1016 | int lttng_syscall_filter_disable(struct lttng_channel *chan, |
| 1017 | const char *name) |
| 1018 | { |
| 1019 | int syscall_nr, compat_syscall_nr, ret; |
| 1020 | struct lttng_syscall_filter *filter; |
| 1021 | |
| 1022 | WARN_ON_ONCE(!chan->sc_table); |
| 1023 | |
| 1024 | if (!chan->sc_filter) { |
| 1025 | filter = kzalloc(sizeof(struct lttng_syscall_filter), |
| 1026 | GFP_KERNEL); |
| 1027 | if (!filter) |
| 1028 | return -ENOMEM; |
| 1029 | /* Trace all system calls, then apply disable. */ |
| 1030 | bitmap_set(filter->sc, 0, NR_syscalls); |
| 1031 | bitmap_set(filter->sc_compat, 0, NR_compat_syscalls); |
| 1032 | } else { |
| 1033 | filter = chan->sc_filter; |
| 1034 | } |
| 1035 | |
| 1036 | if (!name) { |
| 1037 | /* Disable all system calls */ |
| 1038 | bitmap_clear(filter->sc, 0, NR_syscalls); |
| 1039 | bitmap_clear(filter->sc_compat, 0, NR_compat_syscalls); |
| 1040 | goto apply_filter; |
| 1041 | } |
| 1042 | syscall_nr = get_syscall_nr(name); |
| 1043 | compat_syscall_nr = get_compat_syscall_nr(name); |
| 1044 | if (syscall_nr < 0 && compat_syscall_nr < 0) { |
| 1045 | ret = -ENOENT; |
| 1046 | goto error; |
| 1047 | } |
| 1048 | if (syscall_nr >= 0) { |
| 1049 | if (!test_bit(syscall_nr, chan->sc_filter->sc)) { |
| 1050 | ret = -EEXIST; |
| 1051 | goto error; |
| 1052 | } |
| 1053 | bitmap_clear(chan->sc_filter->sc, syscall_nr, 1); |
| 1054 | } |
| 1055 | if (compat_syscall_nr >= 0) { |
| 1056 | if (!test_bit(compat_syscall_nr, chan->sc_filter->sc_compat)) { |
| 1057 | ret = -EEXIST; |
| 1058 | goto error; |
| 1059 | } |
| 1060 | bitmap_clear(chan->sc_filter->sc_compat, compat_syscall_nr, 1); |
| 1061 | } |
| 1062 | apply_filter: |
| 1063 | if (!chan->sc_filter) |
| 1064 | rcu_assign_pointer(chan->sc_filter, filter); |
| 1065 | chan->syscall_all = 0; |
| 1066 | return 0; |
| 1067 | |
| 1068 | error: |
| 1069 | if (!chan->sc_filter) |
| 1070 | kfree(filter); |
| 1071 | return ret; |
| 1072 | } |