1 2 /*--------------------------------------------------------------------*/ 3 /*--- Process-related libc stuff. m_libcproc.c ---*/ 4 /*--------------------------------------------------------------------*/ 5 6 /* 7 This file is part of Valgrind, a dynamic binary instrumentation 8 framework. 9 10 Copyright (C) 2000-2015 Julian Seward 11 jseward (at) acm.org 12 13 This program is free software; you can redistribute it and/or 14 modify it under the terms of the GNU General Public License as 15 published by the Free Software Foundation; either version 2 of the 16 License, or (at your option) any later version. 17 18 This program is distributed in the hope that it will be useful, but 19 WITHOUT ANY WARRANTY; without even the implied warranty of 20 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 21 General Public License for more details. 22 23 You should have received a copy of the GNU General Public License 24 along with this program; if not, write to the Free Software 25 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 26 02111-1307, USA. 27 28 The GNU General Public License is contained in the file COPYING. 29 */ 30 31 #include "pub_core_basics.h" 32 #include "pub_core_machine.h" // For VG_(machine_get_VexArchInfo) 33 #include "pub_core_vki.h" 34 #include "pub_core_vkiscnums.h" 35 #include "pub_core_libcbase.h" 36 #include "pub_core_libcassert.h" 37 #include "pub_core_libcfile.h" 38 #include "pub_core_libcprint.h" 39 #include "pub_core_libcproc.h" 40 #include "pub_core_libcsignal.h" 41 #include "pub_core_seqmatch.h" 42 #include "pub_core_mallocfree.h" 43 #include "pub_core_syscall.h" 44 #include "pub_core_xarray.h" 45 #include "pub_core_clientstate.h" 46 47 #if defined(VGO_darwin) 48 /* --- !!! --- EXTERNAL HEADERS start --- !!! --- */ 49 #include <mach/mach.h> /* mach_thread_self */ 50 /* --- !!! --- EXTERNAL HEADERS end --- !!! --- */ 51 #endif 52 53 /* IMPORTANT: on Darwin it is essential to use the _nocancel versions 54 of syscalls rather than the vanilla version, if a _nocancel version 55 is available. See docs/internals/Darwin-notes.txt for the reason 56 why. */ 57 58 /* --------------------------------------------------------------------- 59 Command line and environment stuff 60 ------------------------------------------------------------------ */ 61 62 /* As deduced from sp_at_startup, the client's argc, argv[] and 63 envp[] as extracted from the client's stack at startup-time. */ 64 HChar** VG_(client_envp) = NULL; 65 66 /* Path to library directory */ 67 const HChar *VG_(libdir) = VG_LIBDIR; 68 69 const HChar *VG_(LD_PRELOAD_var_name) = 70 #if defined(VGO_linux) || defined(VGO_solaris) 71 "LD_PRELOAD"; 72 #elif defined(VGO_darwin) 73 "DYLD_INSERT_LIBRARIES"; 74 #else 75 # error Unknown OS 76 #endif 77 78 /* We do getenv without libc's help by snooping around in 79 VG_(client_envp) as determined at startup time. */ 80 HChar *VG_(getenv)(const HChar *varname) 81 { 82 Int i, n; 83 vg_assert( VG_(client_envp) ); 84 n = VG_(strlen)(varname); 85 for (i = 0; VG_(client_envp)[i] != NULL; i++) { 86 HChar* s = VG_(client_envp)[i]; 87 if (VG_(strncmp)(varname, s, n) == 0 && s[n] == '=') { 88 return & s[n+1]; 89 } 90 } 91 return NULL; 92 } 93 94 /* If free_fn is not NULL, it is called on "unset" environment variable. */ 95 void VG_(env_unsetenv) ( HChar **env, const HChar *varname, 96 void (*free_fn) (void *) ) 97 { 98 HChar **from, **to; 99 vg_assert(env); 100 vg_assert(varname); 101 to = NULL; 102 Int len = VG_(strlen)(varname); 103 104 for (from = to = env; from && *from; from++) { 105 if (!(VG_(strncmp)(varname, *from, len) == 0 && (*from)[len] == '=')) { 106 *to = *from; 107 to++; 108 } else if (free_fn != NULL) { 109 free_fn(*from); 110 } 111 } 112 *to = *from; 113 } 114 115 /* set the environment; returns the old env if a new one was allocated */ 116 HChar **VG_(env_setenv) ( HChar ***envp, const HChar* varname, 117 const HChar *val ) 118 { 119 HChar **env = (*envp); 120 HChar **cpp; 121 Int len = VG_(strlen)(varname); 122 HChar *valstr = VG_(malloc)("libcproc.es.1", len + VG_(strlen)(val) + 2); 123 HChar **oldenv = NULL; 124 125 VG_(sprintf)(valstr, "%s=%s", varname, val); 126 127 for (cpp = env; cpp && *cpp; cpp++) { 128 if (VG_(strncmp)(varname, *cpp, len) == 0 && (*cpp)[len] == '=') { 129 *cpp = valstr; 130 return oldenv; 131 } 132 } 133 134 if (env == NULL) { 135 env = VG_(malloc)("libcproc.es.2", sizeof(HChar *) * 2); 136 env[0] = valstr; 137 env[1] = NULL; 138 139 *envp = env; 140 141 } else { 142 Int envlen = (cpp-env) + 2; 143 HChar **newenv = VG_(malloc)("libcproc.es.3", envlen * sizeof(HChar *)); 144 145 for (cpp = newenv; *env; ) 146 *cpp++ = *env++; 147 *cpp++ = valstr; 148 *cpp++ = NULL; 149 150 oldenv = *envp; 151 152 *envp = newenv; 153 } 154 155 return oldenv; 156 } 157 158 159 /* Walk through a colon-separated environment variable, and remove the 160 entries which match remove_pattern. It slides everything down over 161 the removed entries, and pads the remaining space with '\0'. It 162 modifies the entries in place (in the client address space), but it 163 shouldn't matter too much, since we only do this just before an 164 execve(). 165 166 This is also careful to mop up any excess ':'s, since empty strings 167 delimited by ':' are considered to be '.' in a path. 168 */ 169 static void mash_colon_env(HChar *varp, const HChar *remove_pattern) 170 { 171 HChar *const start = varp; 172 HChar *entry_start = varp; 173 HChar *output = varp; 174 175 if (varp == NULL) 176 return; 177 178 while(*varp) { 179 if (*varp == ':') { 180 HChar prev; 181 Bool match; 182 183 /* This is a bit subtle: we want to match against the entry 184 we just copied, because it may have overlapped with 185 itself, junking the original. */ 186 187 prev = *output; 188 *output = '\0'; 189 190 match = VG_(string_match)(remove_pattern, entry_start); 191 192 *output = prev; 193 194 if (match) { 195 output = entry_start; 196 varp++; /* skip ':' after removed entry */ 197 } else 198 entry_start = output+1; /* entry starts after ':' */ 199 } 200 201 if (*varp) 202 *output++ = *varp++; 203 } 204 205 /* make sure last entry is nul terminated */ 206 *output = '\0'; 207 208 /* match against the last entry */ 209 if (VG_(string_match)(remove_pattern, entry_start)) { 210 output = entry_start; 211 if (output > start) { 212 /* remove trailing ':' */ 213 output--; 214 vg_assert(*output == ':'); 215 } 216 } 217 218 /* pad out the left-overs with '\0' */ 219 while(output < varp) 220 *output++ = '\0'; 221 } 222 223 224 /* Removes all the Valgrind-added stuff from the passed environment. Used 225 when starting child processes, so they don't see that added stuff. 226 If the ro_strings option is set to True then all strings referenced by envp 227 are considered read-only, which means they will be duplicated before they 228 are modified. 229 If free_fn is not NULL, it is called on "unset" environment variables. */ 230 void VG_(env_remove_valgrind_env_stuff)(HChar** envp, Bool ro_strings, 231 void (*free_fn) (void *) ) 232 { 233 Int i; 234 HChar* ld_preload_str = NULL; 235 HChar* ld_library_path_str = NULL; 236 HChar* dyld_insert_libraries_str = NULL; 237 HChar* buf; 238 239 // Find LD_* variables 240 // DDD: should probably conditionally compiled some of this: 241 // - LD_LIBRARY_PATH is universal? 242 // - LD_PRELOAD is on Linux, not on Darwin, not sure about AIX 243 // - DYLD_INSERT_LIBRARIES and DYLD_SHARED_REGION are Darwin-only 244 for (i = 0; envp[i] != NULL; i++) { 245 if (VG_(strncmp)(envp[i], "LD_PRELOAD=", 11) == 0) { 246 if (ro_strings) 247 envp[i] = VG_(strdup)("libcproc.erves.1", envp[i]); 248 ld_preload_str = &envp[i][11]; 249 } 250 if (VG_(strncmp)(envp[i], "LD_LIBRARY_PATH=", 16) == 0) { 251 if (ro_strings) 252 envp[i] = VG_(strdup)("libcproc.erves.2", envp[i]); 253 ld_library_path_str = &envp[i][16]; 254 } 255 if (VG_(strncmp)(envp[i], "DYLD_INSERT_LIBRARIES=", 22) == 0) { 256 if (ro_strings) 257 envp[i] = VG_(strdup)("libcproc.erves.3", envp[i]); 258 dyld_insert_libraries_str = &envp[i][22]; 259 } 260 } 261 262 buf = VG_(malloc)("libcproc.erves.4", VG_(strlen)(VG_(libdir)) + 20); 263 264 // Remove Valgrind-specific entries from LD_*. 265 VG_(sprintf)(buf, "%s*/vgpreload_*.so", VG_(libdir)); 266 mash_colon_env(ld_preload_str, buf); 267 mash_colon_env(dyld_insert_libraries_str, buf); 268 VG_(sprintf)(buf, "%s*", VG_(libdir)); 269 mash_colon_env(ld_library_path_str, buf); 270 271 // Remove VALGRIND_LAUNCHER variable. 272 VG_(env_unsetenv)(envp, VALGRIND_LAUNCHER, free_fn); 273 274 // Remove DYLD_SHARED_REGION variable. 275 VG_(env_unsetenv)(envp, "DYLD_SHARED_REGION", free_fn); 276 277 // XXX if variable becomes empty, remove it completely? 278 279 VG_(free)(buf); 280 } 281 282 /* Resolves filename of VG_(cl_exec_fd) and copies it to the buffer. 283 Buffer must not be NULL and buf_size must be at least 1. 284 If buffer is not large enough it is terminated with '\0' only 285 when 'terminate_with_NUL == True'. */ 286 void VG_(client_fname)(HChar *buffer, SizeT buf_size, Bool terminate_with_NUL) 287 { 288 vg_assert(buffer != NULL); 289 vg_assert(buf_size >= 1); 290 291 const HChar *name; 292 if (VG_(resolve_filename)(VG_(cl_exec_fd), &name)) { 293 const HChar *n = name + VG_(strlen)(name) - 1; 294 295 while (n > name && *n != '/') 296 n--; 297 if (n != name) 298 n++; 299 300 VG_(strncpy)(buffer, n, buf_size); 301 if (terminate_with_NUL) 302 buffer[buf_size - 1] = '\0'; 303 } else { 304 buffer[0] = '\0'; 305 } 306 } 307 308 static Bool add_string(HChar *buffer, SizeT *buf_size, const HChar *string) 309 { 310 SizeT len = VG_(strlen)(string); 311 VG_(strncat)(buffer, string, *buf_size); 312 if (len >= *buf_size - 1) { 313 *buf_size = 0; 314 return False; 315 } else { 316 *buf_size -= len; 317 return True; 318 } 319 } 320 321 /* Concatenates client exename and command line arguments into 322 the buffer. Buffer must not be NULL and buf_size must be 323 at least 1. Buffer is always terminated with '\0'. */ 324 void VG_(client_cmd_and_args)(HChar *buffer, SizeT buf_size) 325 { 326 vg_assert(buffer != NULL); 327 vg_assert(buf_size >= 1); 328 329 buffer[0] = '\0'; 330 331 if (add_string(buffer, &buf_size, VG_(args_the_exename)) == False) 332 return; 333 334 Int i; 335 for (i = 0; i < VG_(sizeXA)(VG_(args_for_client)); i++) { 336 if (add_string(buffer, &buf_size, " ") == False) 337 return; 338 339 HChar *arg = *(HChar **) VG_(indexXA)(VG_(args_for_client), i); 340 if (add_string(buffer, &buf_size, arg) == False) 341 return; 342 } 343 } 344 345 /* --------------------------------------------------------------------- 346 Various important syscall wrappers 347 ------------------------------------------------------------------ */ 348 349 Int VG_(waitpid)(Int pid, Int *status, Int options) 350 { 351 # if defined(VGO_linux) 352 SysRes res = VG_(do_syscall4)(__NR_wait4, 353 pid, (UWord)status, options, 0); 354 return sr_isError(res) ? -1 : sr_Res(res); 355 # elif defined(VGO_darwin) 356 SysRes res = VG_(do_syscall4)(__NR_wait4_nocancel, 357 pid, (UWord)status, options, 0); 358 return sr_isError(res) ? -1 : sr_Res(res); 359 # elif defined(VGO_solaris) 360 SysRes res; 361 vki_idtype_t idtype; 362 vki_id_t id; 363 vki_siginfo_t info; 364 365 /* We need to do a lot of work here. */ 366 367 if (pid > 0) { 368 idtype = VKI_P_PID; 369 id = pid; 370 } 371 else if (pid < -1) { 372 idtype = VKI_P_PGID; 373 id = -pid; 374 } 375 else if (pid == -1) { 376 idtype = VKI_P_ALL; 377 id = 0; 378 } 379 else { 380 idtype = VKI_P_PGID; 381 res = VG_(do_syscall0)(__NR_getpid); 382 id = sr_ResHI(res); 383 } 384 385 options |= VKI_WEXITED | VKI_WTRAPPED; 386 387 res = VG_(do_syscall4)(__NR_waitsys, idtype, id, (UWord)&info, options); 388 if (sr_isError(res)) 389 return -1; 390 391 if (status) { 392 Int s = info.si_status & 0xff; 393 394 switch (info.si_code) { 395 case VKI_CLD_EXITED: 396 s <<= 8; 397 break; 398 case VKI_CLD_DUMPED: 399 s |= VKI_WCOREFLG; 400 break; 401 case VKI_CLD_KILLED: 402 break; 403 case VKI_CLD_TRAPPED: 404 case VKI_CLD_STOPPED: 405 s <<= 8; 406 s |= VKI_WSTOPFLG; 407 break; 408 case VKI_CLD_CONTINUED: 409 s = VKI_WCONTFLG; 410 break; 411 } 412 *status = s; 413 } 414 415 return info.si_pid; 416 # else 417 # error Unknown OS 418 # endif 419 } 420 421 /* clone the environment */ 422 HChar **VG_(env_clone) ( HChar **oldenv ) 423 { 424 HChar **oldenvp; 425 HChar **newenvp; 426 HChar **newenv; 427 Int envlen; 428 429 vg_assert(oldenv); 430 for (oldenvp = oldenv; oldenvp && *oldenvp; oldenvp++); 431 432 envlen = oldenvp - oldenv + 1; 433 434 newenv = VG_(malloc)("libcproc.ec.1", envlen * sizeof(HChar *)); 435 436 oldenvp = oldenv; 437 newenvp = newenv; 438 439 while (oldenvp && *oldenvp) { 440 *newenvp++ = *oldenvp++; 441 } 442 443 *newenvp = *oldenvp; 444 445 return newenv; 446 } 447 448 void VG_(execv) ( const HChar* filename, const HChar** argv ) 449 { 450 HChar** envp; 451 SysRes res; 452 453 /* restore the DATA rlimit for the child */ 454 VG_(setrlimit)(VKI_RLIMIT_DATA, &VG_(client_rlimit_data)); 455 456 envp = VG_(env_clone)(VG_(client_envp)); 457 VG_(env_remove_valgrind_env_stuff)( envp, True /*ro_strings*/, NULL ); 458 459 res = VG_(do_syscall3)(__NR_execve, 460 (UWord)filename, (UWord)argv, (UWord)envp); 461 462 VG_(printf)("EXEC failed, errno = %lld\n", (Long)sr_Err(res)); 463 } 464 465 /* Spawns a new child. Uses either spawn syscall or fork+execv combo. */ 466 Int VG_(spawn) ( const HChar *filename, const HChar **argv ) 467 { 468 vg_assert(filename != NULL); 469 vg_assert(argv != NULL); 470 471 # if defined(VGO_solaris) && defined(SOLARIS_SPAWN_SYSCALL) 472 HChar **envp = VG_(env_clone)(VG_(client_envp)); 473 for (HChar **p = envp; *p != NULL; p++) { 474 *p = VG_(strdup)("libcproc.s.1", *p); 475 } 476 VG_(env_remove_valgrind_env_stuff)(envp, /* ro_strings */ False, VG_(free)); 477 478 /* Now combine argv and argp into argenv. */ 479 SizeT argenv_size = 1 + 1; 480 for (const HChar **p = argv; *p != NULL; p++) { 481 argenv_size += VG_(strlen)(*p) + 2; 482 } 483 for (HChar **p = envp; *p != NULL; p++) { 484 argenv_size += VG_(strlen)(*p) + 2; 485 } 486 487 HChar *argenv = VG_(malloc)("libcproc.s.2", argenv_size); 488 HChar *current = argenv; 489 # define COPY_CHAR_TO_ARGENV(dst, character) \ 490 do { \ 491 *(dst) = character; \ 492 (dst) += 1; \ 493 } while (0) 494 # define COPY_STRING_TO_ARGENV(dst, src) \ 495 do { \ 496 COPY_CHAR_TO_ARGENV(dst, '\1'); \ 497 SizeT src_len = VG_(strlen)((src)) + 1; \ 498 VG_(memcpy)((dst), (src), src_len); \ 499 (dst) += src_len; \ 500 } while (0) 501 502 for (const HChar **p = argv; *p != NULL; p++) { 503 COPY_STRING_TO_ARGENV(current, *p); 504 } 505 COPY_CHAR_TO_ARGENV(current, '\0'); 506 for (HChar **p = envp; *p != NULL; p++) { 507 COPY_STRING_TO_ARGENV(current, *p); 508 } 509 COPY_CHAR_TO_ARGENV(current, '\0'); 510 vg_assert(current == argenv + argenv_size); 511 # undef COPY_CHAR_TO_ARGENV 512 # undef COPY_STRING_TOARGENV 513 514 /* HACK: Temporarily restore the DATA rlimit for spawned child. */ 515 VG_(setrlimit)(VKI_RLIMIT_DATA, &VG_(client_rlimit_data)); 516 517 SysRes res = VG_(do_syscall5)(__NR_spawn, (UWord) filename, (UWord) NULL, 0, 518 (UWord) argenv, argenv_size); 519 520 /* Restore DATA rlimit back to its previous value set in m_main.c. */ 521 struct vki_rlimit zero = { 0, 0 }; 522 zero.rlim_max = VG_(client_rlimit_data).rlim_max; 523 VG_(setrlimit)(VKI_RLIMIT_DATA, &zero); 524 525 VG_(free)(argenv); 526 for (HChar **p = envp; *p != NULL; p++) { 527 VG_(free)(*p); 528 } 529 VG_(free)(envp); 530 531 if (sr_isError(res)) 532 return -1; 533 return sr_Res(res); 534 535 # else 536 537 Int pid = VG_(fork)(); 538 if (pid < 0) 539 return -1; 540 if (pid == 0) { 541 /* child */ 542 VG_(execv)(argv[0], argv); 543 544 /* If we're still alive here, execv failed. */ 545 VG_(exit)(1); 546 } else { 547 return pid; 548 } 549 # endif /* VGO_solaris && SOLARIS_SPAWN_SYSCALL */ 550 } 551 552 /* Return -1 if error, else 0. NOTE does not indicate return code of 553 child! */ 554 Int VG_(system) ( const HChar* cmd ) 555 { 556 Int pid; 557 if (cmd == NULL) 558 return 1; 559 560 const HChar *argv[4] = { "/bin/sh", "-c", cmd, 0 }; 561 pid = VG_(spawn)(argv[0], argv); 562 if (pid < 0) 563 return -1; 564 565 vg_assert(pid > 0); 566 /* parent */ 567 /* We have to set SIGCHLD to its default behaviour in order that 568 VG_(waitpid) works (at least on AIX). According to the Linux 569 man page for waitpid: 570 571 POSIX.1-2001 specifies that if the disposition of SIGCHLD is 572 set to SIG_IGN or the SA_NOCLDWAIT flag is set for SIGCHLD 573 (see sigaction(2)), then children that terminate do not 574 become zombies and a call to wait() or waitpid() will block 575 until all children have terminated, and then fail with errno 576 set to ECHILD. (The original POSIX standard left the 577 behaviour of setting SIGCHLD to SIG_IGN unspecified.) 578 */ 579 Int ir, zzz; 580 vki_sigaction_toK_t sa, sa2; 581 vki_sigaction_fromK_t saved_sa; 582 VG_(memset)( &sa, 0, sizeof(sa) ); 583 VG_(sigemptyset)(&sa.sa_mask); 584 sa.ksa_handler = VKI_SIG_DFL; 585 sa.sa_flags = 0; 586 ir = VG_(sigaction)(VKI_SIGCHLD, &sa, &saved_sa); 587 vg_assert(ir == 0); 588 589 zzz = VG_(waitpid)(pid, NULL, 0); 590 591 VG_(convert_sigaction_fromK_to_toK)( &saved_sa, &sa2 ); 592 ir = VG_(sigaction)(VKI_SIGCHLD, &sa2, NULL); 593 vg_assert(ir == 0); 594 return zzz == -1 ? -1 : 0; 595 } 596 597 Int VG_(sysctl)(Int *name, UInt namelen, void *oldp, SizeT *oldlenp, void *newp, SizeT newlen) 598 { 599 SysRes res; 600 # if defined(VGO_darwin) 601 res = VG_(do_syscall6)(__NR___sysctl, 602 (UWord)name, namelen, (UWord)oldp, (UWord)oldlenp, (UWord)newp, newlen); 603 # else 604 res = VG_(mk_SysRes_Error)(VKI_ENOSYS); 605 # endif 606 return sr_isError(res) ? -1 : sr_Res(res); 607 } 608 609 /* --------------------------------------------------------------------- 610 Resource limits 611 ------------------------------------------------------------------ */ 612 613 /* Support for getrlimit. */ 614 Int VG_(getrlimit) (Int resource, struct vki_rlimit *rlim) 615 { 616 SysRes res = VG_(mk_SysRes_Error)(VKI_ENOSYS); 617 /* res = getrlimit( resource, rlim ); */ 618 # ifdef __NR_ugetrlimit 619 res = VG_(do_syscall2)(__NR_ugetrlimit, resource, (UWord)rlim); 620 # endif 621 if (sr_isError(res) && sr_Err(res) == VKI_ENOSYS) 622 res = VG_(do_syscall2)(__NR_getrlimit, resource, (UWord)rlim); 623 return sr_isError(res) ? -1 : sr_Res(res); 624 } 625 626 627 /* Support for setrlimit. */ 628 Int VG_(setrlimit) (Int resource, const struct vki_rlimit *rlim) 629 { 630 SysRes res; 631 /* res = setrlimit( resource, rlim ); */ 632 res = VG_(do_syscall2)(__NR_setrlimit, resource, (UWord)rlim); 633 return sr_isError(res) ? -1 : sr_Res(res); 634 } 635 636 /* Support for prctl. */ 637 Int VG_(prctl) (Int option, 638 ULong arg2, ULong arg3, ULong arg4, ULong arg5) 639 { 640 SysRes res = VG_(mk_SysRes_Error)(VKI_ENOSYS); 641 # if defined(VGO_linux) 642 /* res = prctl( option, arg2, arg3, arg4, arg5 ); */ 643 res = VG_(do_syscall5)(__NR_prctl, (UWord) option, 644 (UWord) arg2, (UWord) arg3, (UWord) arg4, 645 (UWord) arg5); 646 # endif 647 648 return sr_isError(res) ? -1 : sr_Res(res); 649 } 650 651 /* --------------------------------------------------------------------- 652 pids, etc 653 ------------------------------------------------------------------ */ 654 655 Int VG_(gettid)(void) 656 { 657 # if defined(VGO_linux) 658 SysRes res = VG_(do_syscall0)(__NR_gettid); 659 660 if (sr_isError(res) && sr_Res(res) == VKI_ENOSYS) { 661 HChar pid[16]; 662 /* 663 * The gettid system call does not exist. The obvious assumption 664 * to make at this point would be that we are running on an older 665 * system where the getpid system call actually returns the ID of 666 * the current thread. 667 * 668 * Unfortunately it seems that there are some systems with a kernel 669 * where getpid has been changed to return the ID of the thread group 670 * leader but where the gettid system call has not yet been added. 671 * 672 * So instead of calling getpid here we use readlink to see where 673 * the /proc/self link is pointing... 674 */ 675 676 # if defined(VGP_arm64_linux) || defined(VGP_tilegx_linux) 677 res = VG_(do_syscall4)(__NR_readlinkat, VKI_AT_FDCWD, 678 (UWord)"/proc/self", 679 (UWord)pid, sizeof(pid)); 680 # else 681 res = VG_(do_syscall3)(__NR_readlink, (UWord)"/proc/self", 682 (UWord)pid, sizeof(pid)); 683 # endif 684 if (!sr_isError(res) && sr_Res(res) > 0) { 685 HChar* s; 686 pid[sr_Res(res)] = '\0'; 687 res = VG_(mk_SysRes_Success)( VG_(strtoll10)(pid, &s) ); 688 if (*s != '\0') { 689 VG_(message)(Vg_DebugMsg, 690 "Warning: invalid file name linked to by /proc/self: %s\n", 691 pid); 692 } 693 } 694 } 695 696 return sr_Res(res); 697 698 # elif defined(VGO_darwin) 699 // Darwin's gettid syscall is something else. 700 // Use Mach thread ports for lwpid instead. 701 return mach_thread_self(); 702 703 # elif defined(VGO_solaris) 704 SysRes res = VG_(do_syscall0)(__NR_lwp_self); 705 return sr_Res(res); 706 707 # else 708 # error "Unknown OS" 709 # endif 710 } 711 712 /* You'd be amazed how many places need to know the current pid. */ 713 Int VG_(getpid) ( void ) 714 { 715 /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ 716 return sr_Res( VG_(do_syscall0)(__NR_getpid) ); 717 } 718 719 Int VG_(getpgrp) ( void ) 720 { 721 /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ 722 # if defined(VGO_linux) || defined(VGO_darwin) 723 return sr_Res( VG_(do_syscall0)(__NR_getpgrp) ); 724 # elif defined(VGO_solaris) 725 /* Uses the shared pgrpsys syscall, 0 for the getpgrp variant. */ 726 return sr_Res( VG_(do_syscall1)(__NR_pgrpsys, 0) ); 727 # else 728 # error Unknown OS 729 # endif 730 } 731 732 Int VG_(getppid) ( void ) 733 { 734 /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ 735 # if defined(VGO_linux) || defined(VGO_darwin) 736 return sr_Res( VG_(do_syscall0)(__NR_getppid) ); 737 # elif defined(VGO_solaris) 738 /* Uses the shared getpid/getppid syscall, val2 contains a parent pid. */ 739 return sr_ResHI( VG_(do_syscall0)(__NR_getpid) ); 740 # else 741 # error Unknown OS 742 # endif 743 } 744 745 Int VG_(geteuid) ( void ) 746 { 747 /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ 748 # if defined(VGO_linux) || defined(VGO_darwin) 749 { 750 # if defined(__NR_geteuid32) 751 // We use the 32-bit version if it's supported. Otherwise, IDs greater 752 // than 65536 cause problems, as bug #151209 showed. 753 return sr_Res( VG_(do_syscall0)(__NR_geteuid32) ); 754 # else 755 return sr_Res( VG_(do_syscall0)(__NR_geteuid) ); 756 # endif 757 } 758 # elif defined(VGO_solaris) 759 /* Uses the shared getuid/geteuid syscall, val2 contains the effective 760 uid. */ 761 return sr_ResHI( VG_(do_syscall0)(__NR_getuid) ); 762 # else 763 # error Unknown OS 764 # endif 765 } 766 767 Int VG_(getegid) ( void ) 768 { 769 # if defined(VGO_linux) || defined(VGO_darwin) 770 /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ 771 # if defined(__NR_getegid32) 772 // We use the 32-bit version if it's supported. Otherwise, IDs greater 773 // than 65536 cause problems, as bug #151209 showed. 774 return sr_Res( VG_(do_syscall0)(__NR_getegid32) ); 775 # else 776 return sr_Res( VG_(do_syscall0)(__NR_getegid) ); 777 # endif 778 779 # elif defined(VGO_solaris) 780 /* Uses the shared getgid/getegid syscall, val2 contains the effective 781 gid. */ 782 return sr_ResHI( VG_(do_syscall0)(__NR_getgid) ); 783 # else 784 # error Unknown OS 785 # endif 786 } 787 788 /* Get supplementary groups into list[0 .. size-1]. Returns the 789 number of groups written, or -1 if error. Note that in order to be 790 portable, the groups are 32-bit unsigned ints regardless of the 791 platform. 792 As a special case, if size == 0 the function returns the number of 793 groups leaving list untouched. */ 794 Int VG_(getgroups)( Int size, UInt* list ) 795 { 796 if (size < 0) return -1; 797 798 # if defined(VGP_x86_linux) || defined(VGP_ppc32_linux) \ 799 || defined(VGP_mips64_linux) || defined(VGP_tilegx_linux) 800 Int i; 801 SysRes sres; 802 UShort list16[size]; 803 sres = VG_(do_syscall2)(__NR_getgroups, size, (Addr)list16); 804 if (sr_isError(sres)) 805 return -1; 806 if (size != 0) { 807 for (i = 0; i < sr_Res(sres); i++) 808 list[i] = (UInt)list16[i]; 809 } 810 return sr_Res(sres); 811 812 # elif defined(VGP_amd64_linux) || defined(VGP_arm_linux) \ 813 || defined(VGP_ppc64be_linux) || defined(VGP_ppc64le_linux) \ 814 || defined(VGO_darwin) || defined(VGP_s390x_linux) \ 815 || defined(VGP_mips32_linux) || defined(VGP_arm64_linux) \ 816 || defined(VGO_solaris) 817 SysRes sres; 818 sres = VG_(do_syscall2)(__NR_getgroups, size, (Addr)list); 819 if (sr_isError(sres)) 820 return -1; 821 return sr_Res(sres); 822 823 # else 824 # error "VG_(getgroups): needs implementation on this platform" 825 # endif 826 } 827 828 /* --------------------------------------------------------------------- 829 Process tracing 830 ------------------------------------------------------------------ */ 831 832 Int VG_(ptrace) ( Int request, Int pid, void *addr, void *data ) 833 { 834 SysRes res; 835 # if defined(VGO_linux) || defined(VGO_darwin) 836 res = VG_(do_syscall4)(__NR_ptrace, request, pid, (UWord)addr, (UWord)data); 837 # elif defined(VGO_solaris) 838 /* There is no ptrace syscall on Solaris. Such requests has to be 839 implemented using the /proc interface. Callers of VG_(ptrace) should 840 ensure that this function is not reached on Solaris, i.e. they must 841 provide a special code for Solaris for whatever feature they provide. */ 842 I_die_here; 843 # else 844 # error Unknown OS 845 # endif 846 if (sr_isError(res)) 847 return -1; 848 return sr_Res(res); 849 } 850 851 /* --------------------------------------------------------------------- 852 Fork 853 ------------------------------------------------------------------ */ 854 855 Int VG_(fork) ( void ) 856 { 857 # if defined(VGP_arm64_linux) || defined(VGP_tilegx_linux) 858 SysRes res; 859 res = VG_(do_syscall5)(__NR_clone, VKI_SIGCHLD, 860 (UWord)NULL, (UWord)NULL, (UWord)NULL, (UWord)NULL); 861 if (sr_isError(res)) 862 return -1; 863 return sr_Res(res); 864 865 # elif defined(VGO_linux) 866 SysRes res; 867 res = VG_(do_syscall0)(__NR_fork); 868 if (sr_isError(res)) 869 return -1; 870 return sr_Res(res); 871 872 # elif defined(VGO_darwin) 873 SysRes res; 874 res = VG_(do_syscall0)(__NR_fork); /* __NR_fork is UX64 */ 875 if (sr_isError(res)) 876 return -1; 877 /* on success: wLO = child pid; wHI = 1 for child, 0 for parent */ 878 if (sr_ResHI(res) != 0) { 879 return 0; /* this is child: return 0 instead of child pid */ 880 } 881 return sr_Res(res); 882 883 # elif defined(VGO_solaris) 884 /* Using fork() on Solaris is not really the best thing to do. Solaris 885 does not do memory overcommitment so fork() can fail if there is not 886 enough memory to copy the current process into a new one. 887 Prefer to use VG_(spawn)() over VG_(fork)() + VG_(execv)(). */ 888 SysRes res; 889 res = VG_(do_syscall2)(__NR_forksys, 0 /*subcode (fork)*/, 0 /*flags*/); 890 if (sr_isError(res)) 891 return -1; 892 /* On success: 893 val = a pid of the child in the parent, a pid of the parent in the 894 child, 895 val2 = 0 in the parent process, 1 in the child process. */ 896 if (sr_ResHI(res) != 0) { 897 return 0; 898 } 899 return sr_Res(res); 900 901 # else 902 # error "Unknown OS" 903 # endif 904 } 905 906 /* --------------------------------------------------------------------- 907 Timing stuff 908 ------------------------------------------------------------------ */ 909 910 UInt VG_(read_millisecond_timer) ( void ) 911 { 912 /* 'now' and 'base' are in microseconds */ 913 static ULong base = 0; 914 ULong now; 915 916 # if defined(VGO_linux) || defined(VGO_solaris) 917 { SysRes res; 918 struct vki_timespec ts_now; 919 res = VG_(do_syscall2)(__NR_clock_gettime, VKI_CLOCK_MONOTONIC, 920 (UWord)&ts_now); 921 if (sr_isError(res) == 0) { 922 now = ts_now.tv_sec * 1000000ULL + ts_now.tv_nsec / 1000; 923 } else { 924 struct vki_timeval tv_now; 925 /* Note: On Solaris, this syscall takes only one parameter but the 926 extra dummy one does not cause any harm. */ 927 res = VG_(do_syscall2)(__NR_gettimeofday, (UWord)&tv_now, (UWord)NULL); 928 vg_assert(! sr_isError(res)); 929 now = tv_now.tv_sec * 1000000ULL + tv_now.tv_usec; 930 } 931 } 932 933 # elif defined(VGO_darwin) 934 // Weird: it seems that gettimeofday() doesn't fill in the timeval, but 935 // rather returns the tv_sec as the low 32 bits of the result and the 936 // tv_usec as the high 32 bits of the result. (But the timeval cannot be 937 // NULL!) See bug 200990. 938 { SysRes res; 939 struct vki_timeval tv_now = { 0, 0 }; 940 res = VG_(do_syscall2)(__NR_gettimeofday, (UWord)&tv_now, (UWord)NULL); 941 vg_assert(! sr_isError(res)); 942 now = sr_Res(res) * 1000000ULL + sr_ResHI(res); 943 } 944 945 # else 946 # error "Unknown OS" 947 # endif 948 949 /* COMMON CODE */ 950 if (base == 0) 951 base = now; 952 953 return (now - base) / 1000; 954 } 955 956 Int VG_(gettimeofday)(struct vki_timeval *tv, struct vki_timezone *tz) 957 { 958 SysRes res; 959 res = VG_(do_syscall2)(__NR_gettimeofday, (UWord)tv, (UWord)tz); 960 961 if (! sr_isError(res)) return 0; 962 963 /* Make sure, argument values are determinstic upon failure */ 964 if (tv) *tv = (struct vki_timeval){ .tv_sec = 0, .tv_usec = 0 }; 965 if (tz) *tz = (struct vki_timezone){ .tz_minuteswest = 0, .tz_dsttime = 0 }; 966 967 return -1; 968 } 969 970 971 /* --------------------------------------------------------------------- 972 atfork() 973 ------------------------------------------------------------------ */ 974 975 struct atfork { 976 vg_atfork_t pre; 977 vg_atfork_t parent; 978 vg_atfork_t child; 979 }; 980 981 #define VG_MAX_ATFORK 10 982 983 static struct atfork atforks[VG_MAX_ATFORK]; 984 static Int n_atfork = 0; 985 986 void VG_(atfork)(vg_atfork_t pre, vg_atfork_t parent, vg_atfork_t child) 987 { 988 Int i; 989 990 for (i = 0; i < n_atfork; i++) { 991 if (atforks[i].pre == pre && 992 atforks[i].parent == parent && 993 atforks[i].child == child) 994 return; 995 } 996 997 if (n_atfork >= VG_MAX_ATFORK) 998 VG_(core_panic)( 999 "Too many VG_(atfork) handlers requested: raise VG_MAX_ATFORK"); 1000 1001 atforks[n_atfork].pre = pre; 1002 atforks[n_atfork].parent = parent; 1003 atforks[n_atfork].child = child; 1004 1005 n_atfork++; 1006 } 1007 1008 void VG_(do_atfork_pre)(ThreadId tid) 1009 { 1010 Int i; 1011 1012 for (i = 0; i < n_atfork; i++) 1013 if (atforks[i].pre != NULL) 1014 (*atforks[i].pre)(tid); 1015 } 1016 1017 void VG_(do_atfork_parent)(ThreadId tid) 1018 { 1019 Int i; 1020 1021 for (i = 0; i < n_atfork; i++) 1022 if (atforks[i].parent != NULL) 1023 (*atforks[i].parent)(tid); 1024 } 1025 1026 void VG_(do_atfork_child)(ThreadId tid) 1027 { 1028 Int i; 1029 1030 for (i = 0; i < n_atfork; i++) 1031 if (atforks[i].child != NULL) 1032 (*atforks[i].child)(tid); 1033 } 1034 1035 1036 /* --------------------------------------------------------------------- 1037 icache invalidation 1038 ------------------------------------------------------------------ */ 1039 1040 void VG_(invalidate_icache) ( void *ptr, SizeT nbytes ) 1041 { 1042 if (nbytes == 0) return; // nothing to do 1043 1044 // Get cache info 1045 VexArchInfo vai; 1046 VG_(machine_get_VexArchInfo)(NULL, &vai); 1047 1048 // If I-caches are coherent, nothing needs to be done here 1049 if (vai.hwcache_info.icaches_maintain_coherence) return; 1050 1051 # if defined(VGA_ppc32) || defined(VGA_ppc64be) || defined(VGA_ppc64le) 1052 Addr startaddr = (Addr) ptr; 1053 Addr endaddr = startaddr + nbytes; 1054 Addr cls; 1055 Addr addr; 1056 1057 cls = vai.ppc_icache_line_szB; 1058 1059 /* Stay sane .. */ 1060 vg_assert(cls == 16 || cls == 32 || cls == 64 || cls == 128); 1061 1062 startaddr &= ~(cls - 1); 1063 for (addr = startaddr; addr < endaddr; addr += cls) { 1064 __asm__ __volatile__("dcbst 0,%0" : : "r" (addr)); 1065 } 1066 __asm__ __volatile__("sync"); 1067 for (addr = startaddr; addr < endaddr; addr += cls) { 1068 __asm__ __volatile__("icbi 0,%0" : : "r" (addr)); 1069 } 1070 __asm__ __volatile__("sync; isync"); 1071 1072 # elif defined(VGP_arm_linux) 1073 /* ARM cache flushes are privileged, so we must defer to the kernel. */ 1074 Addr startaddr = (Addr) ptr; 1075 Addr endaddr = startaddr + nbytes; 1076 VG_(do_syscall2)(__NR_ARM_cacheflush, startaddr, endaddr); 1077 1078 # elif defined(VGP_arm64_linux) 1079 // This arm64_linux section of this function VG_(invalidate_icache) 1080 // is copied from 1081 // https://github.com/armvixl/vixl/blob/master/src/a64/cpu-a64.cc 1082 // which has the following copyright notice: 1083 /* 1084 Copyright 2013, ARM Limited 1085 All rights reserved. 1086 1087 Redistribution and use in source and binary forms, with or without 1088 modification, are permitted provided that the following conditions are met: 1089 1090 * Redistributions of source code must retain the above copyright notice, 1091 this list of conditions and the following disclaimer. 1092 * Redistributions in binary form must reproduce the above copyright notice, 1093 this list of conditions and the following disclaimer in the documentation 1094 and/or other materials provided with the distribution. 1095 * Neither the name of ARM Limited nor the names of its contributors may be 1096 used to endorse or promote products derived from this software without 1097 specific prior written permission. 1098 1099 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND 1100 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 1101 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 1102 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE 1103 FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 1104 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 1105 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 1106 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 1107 OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 1108 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 1109 */ 1110 1111 // Ask what the I and D line sizes are 1112 UInt cache_type_register; 1113 // Copy the content of the cache type register to a core register. 1114 __asm__ __volatile__ ("mrs %[ctr], ctr_el0" // NOLINT 1115 : [ctr] "=r" (cache_type_register)); 1116 1117 const Int kDCacheLineSizeShift = 16; 1118 const Int kICacheLineSizeShift = 0; 1119 const UInt kDCacheLineSizeMask = 0xf << kDCacheLineSizeShift; 1120 const UInt kICacheLineSizeMask = 0xf << kICacheLineSizeShift; 1121 1122 // The cache type register holds the size of the I and D caches as a power of 1123 // two. 1124 const UInt dcache_line_size_power_of_two = 1125 (cache_type_register & kDCacheLineSizeMask) >> kDCacheLineSizeShift; 1126 const UInt icache_line_size_power_of_two = 1127 (cache_type_register & kICacheLineSizeMask) >> kICacheLineSizeShift; 1128 1129 const UInt dcache_line_size_ = 4 * (1 << dcache_line_size_power_of_two); 1130 const UInt icache_line_size_ = 4 * (1 << icache_line_size_power_of_two); 1131 1132 Addr start = (Addr)ptr; 1133 // Sizes will be used to generate a mask big enough to cover a pointer. 1134 Addr dsize = (Addr)dcache_line_size_; 1135 Addr isize = (Addr)icache_line_size_; 1136 1137 // Cache line sizes are always a power of 2. 1138 Addr dstart = start & ~(dsize - 1); 1139 Addr istart = start & ~(isize - 1); 1140 Addr end = start + nbytes; 1141 1142 __asm__ __volatile__ ( 1143 // Clean every line of the D cache containing the target data. 1144 "0: \n\t" 1145 // dc : Data Cache maintenance 1146 // c : Clean 1147 // va : by (Virtual) Address 1148 // u : to the point of Unification 1149 // The point of unification for a processor is the point by which the 1150 // instruction and data caches are guaranteed to see the same copy of a 1151 // memory location. See ARM DDI 0406B page B2-12 for more information. 1152 "dc cvau, %[dline] \n\t" 1153 "add %[dline], %[dline], %[dsize] \n\t" 1154 "cmp %[dline], %[end] \n\t" 1155 "b.lt 0b \n\t" 1156 // Barrier to make sure the effect of the code above is visible to the rest 1157 // of the world. 1158 // dsb : Data Synchronisation Barrier 1159 // ish : Inner SHareable domain 1160 // The point of unification for an Inner Shareable shareability domain is 1161 // the point by which the instruction and data caches of all the processors 1162 // in that Inner Shareable shareability domain are guaranteed to see the 1163 // same copy of a memory location. See ARM DDI 0406B page B2-12 for more 1164 // information. 1165 "dsb ish \n\t" 1166 // Invalidate every line of the I cache containing the target data. 1167 "1: \n\t" 1168 // ic : instruction cache maintenance 1169 // i : invalidate 1170 // va : by address 1171 // u : to the point of unification 1172 "ic ivau, %[iline] \n\t" 1173 "add %[iline], %[iline], %[isize] \n\t" 1174 "cmp %[iline], %[end] \n\t" 1175 "b.lt 1b \n\t" 1176 // Barrier to make sure the effect of the code above is visible to the rest 1177 // of the world. 1178 "dsb ish \n\t" 1179 // Barrier to ensure any prefetching which happened before this code is 1180 // discarded. 1181 // isb : Instruction Synchronisation Barrier 1182 "isb \n\t" 1183 : [dline] "+r" (dstart), 1184 [iline] "+r" (istart) 1185 : [dsize] "r" (dsize), 1186 [isize] "r" (isize), 1187 [end] "r" (end) 1188 // This code does not write to memory but without the dependency gcc might 1189 // move this code before the code is generated. 1190 : "cc", "memory" 1191 ); 1192 1193 # elif defined(VGA_mips32) || defined(VGA_mips64) 1194 SysRes sres = VG_(do_syscall3)(__NR_cacheflush, (UWord) ptr, 1195 (UWord) nbytes, (UWord) 3); 1196 vg_assert( !sr_isError(sres) ); 1197 1198 # elif defined(VGA_tilegx) 1199 const HChar *start, *end; 1200 1201 /* L1 ICache is 32KB. cacheline size is 64 bytes. */ 1202 if (nbytes > 0x8000) nbytes = 0x8000; 1203 1204 start = (const HChar *)((unsigned long)ptr & -64ULL); 1205 end = (const HChar*)ptr + nbytes - 1; 1206 1207 __insn_mf(); 1208 1209 do { 1210 const HChar* p; 1211 for (p = start; p <= end; p += 64) 1212 __insn_icoh(p); 1213 } while (0); 1214 1215 __insn_drain(); 1216 1217 # endif 1218 } 1219 1220 1221 /* --------------------------------------------------------------------- 1222 dcache flushing 1223 ------------------------------------------------------------------ */ 1224 1225 void VG_(flush_dcache) ( void *ptr, SizeT nbytes ) 1226 { 1227 /* Currently this is only required on ARM64. */ 1228 # if defined(VGA_arm64) 1229 Addr startaddr = (Addr) ptr; 1230 Addr endaddr = startaddr + nbytes; 1231 Addr cls; 1232 Addr addr; 1233 1234 ULong ctr_el0; 1235 __asm__ __volatile__ ("mrs %0, ctr_el0" : "=r"(ctr_el0)); 1236 cls = 4 * (1ULL << (0xF & (ctr_el0 >> 16))); 1237 1238 /* Stay sane .. */ 1239 vg_assert(cls == 64); 1240 1241 startaddr &= ~(cls - 1); 1242 for (addr = startaddr; addr < endaddr; addr += cls) { 1243 __asm__ __volatile__("dc cvau, %0" : : "r" (addr)); 1244 } 1245 __asm__ __volatile__("dsb ish"); 1246 # endif 1247 } 1248 1249 /*--------------------------------------------------------------------*/ 1250 /*--- end ---*/ 1251 /*--------------------------------------------------------------------*/ 1252
