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) 2000-2013 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_libcprint.h" 38 #include "pub_core_libcproc.h" 39 #include "pub_core_libcsignal.h" 40 #include "pub_core_seqmatch.h" 41 #include "pub_core_mallocfree.h" 42 #include "pub_core_syscall.h" 43 #include "pub_core_xarray.h" 44 #include "pub_core_clientstate.h" 45 46 #if defined(VGO_darwin) 47 /* --- !!! --- EXTERNAL HEADERS start --- !!! --- */ 48 #include <mach/mach.h> /* mach_thread_self */ 49 /* --- !!! --- EXTERNAL HEADERS end --- !!! --- */ 50 #endif 51 52 /* IMPORTANT: on Darwin it is essential to use the _nocancel versions 53 of syscalls rather than the vanilla version, if a _nocancel version 54 is available. See docs/internals/Darwin-notes.txt for the reason 55 why. */ 56 57 /* --------------------------------------------------------------------- 58 Command line and environment stuff 59 ------------------------------------------------------------------ */ 60 61 /* As deduced from sp_at_startup, the client's argc, argv[] and 62 envp[] as extracted from the client's stack at startup-time. */ 63 HChar** VG_(client_envp) = NULL; 64 65 /* Path to library directory */ 66 const HChar *VG_(libdir) = VG_LIBDIR; 67 68 const HChar *VG_(LD_PRELOAD_var_name) = 69 #if defined(VGO_linux) 70 "LD_PRELOAD"; 71 #elif defined(VGO_darwin) 72 "DYLD_INSERT_LIBRARIES"; 73 #else 74 # error Unknown OS 75 #endif 76 77 /* We do getenv without libc's help by snooping around in 78 VG_(client_envp) as determined at startup time. */ 79 HChar *VG_(getenv)(const HChar *varname) 80 { 81 Int i, n; 82 vg_assert( VG_(client_envp) ); 83 n = VG_(strlen)(varname); 84 for (i = 0; VG_(client_envp)[i] != NULL; i++) { 85 HChar* s = VG_(client_envp)[i]; 86 if (VG_(strncmp)(varname, s, n) == 0 && s[n] == '=') { 87 return & s[n+1]; 88 } 89 } 90 return NULL; 91 } 92 93 void VG_(env_unsetenv) ( HChar **env, const HChar *varname ) 94 { 95 HChar **from, **to; 96 vg_assert(env); 97 vg_assert(varname); 98 to = NULL; 99 Int len = VG_(strlen)(varname); 100 101 for (from = to = env; from && *from; from++) { 102 if (!(VG_(strncmp)(varname, *from, len) == 0 && (*from)[len] == '=')) { 103 *to = *from; 104 to++; 105 } 106 } 107 *to = *from; 108 } 109 110 /* set the environment; returns the old env if a new one was allocated */ 111 HChar **VG_(env_setenv) ( HChar ***envp, const HChar* varname, 112 const HChar *val ) 113 { 114 HChar **env = (*envp); 115 HChar **cpp; 116 Int len = VG_(strlen)(varname); 117 HChar *valstr = VG_(arena_malloc)(VG_AR_CORE, "libcproc.es.1", 118 len + VG_(strlen)(val) + 2); 119 HChar **oldenv = NULL; 120 121 VG_(sprintf)(valstr, "%s=%s", varname, val); 122 123 for (cpp = env; cpp && *cpp; cpp++) { 124 if (VG_(strncmp)(varname, *cpp, len) == 0 && (*cpp)[len] == '=') { 125 *cpp = valstr; 126 return oldenv; 127 } 128 } 129 130 if (env == NULL) { 131 env = VG_(arena_malloc)(VG_AR_CORE, "libcproc.es.2", sizeof(HChar *) * 2); 132 env[0] = valstr; 133 env[1] = NULL; 134 135 *envp = env; 136 137 } else { 138 Int envlen = (cpp-env) + 2; 139 HChar **newenv = VG_(arena_malloc)(VG_AR_CORE, "libcproc.es.3", 140 envlen * sizeof(HChar *)); 141 142 for (cpp = newenv; *env; ) 143 *cpp++ = *env++; 144 *cpp++ = valstr; 145 *cpp++ = NULL; 146 147 oldenv = *envp; 148 149 *envp = newenv; 150 } 151 152 return oldenv; 153 } 154 155 156 /* Walk through a colon-separated environment variable, and remove the 157 entries which match remove_pattern. It slides everything down over 158 the removed entries, and pads the remaining space with '\0'. It 159 modifies the entries in place (in the client address space), but it 160 shouldn't matter too much, since we only do this just before an 161 execve(). 162 163 This is also careful to mop up any excess ':'s, since empty strings 164 delimited by ':' are considered to be '.' in a path. 165 */ 166 static void mash_colon_env(HChar *varp, const HChar *remove_pattern) 167 { 168 HChar *const start = varp; 169 HChar *entry_start = varp; 170 HChar *output = varp; 171 172 if (varp == NULL) 173 return; 174 175 while(*varp) { 176 if (*varp == ':') { 177 HChar prev; 178 Bool match; 179 180 /* This is a bit subtle: we want to match against the entry 181 we just copied, because it may have overlapped with 182 itself, junking the original. */ 183 184 prev = *output; 185 *output = '\0'; 186 187 match = VG_(string_match)(remove_pattern, entry_start); 188 189 *output = prev; 190 191 if (match) { 192 output = entry_start; 193 varp++; /* skip ':' after removed entry */ 194 } else 195 entry_start = output+1; /* entry starts after ':' */ 196 } 197 198 if (*varp) 199 *output++ = *varp++; 200 } 201 202 /* make sure last entry is nul terminated */ 203 *output = '\0'; 204 205 /* match against the last entry */ 206 if (VG_(string_match)(remove_pattern, entry_start)) { 207 output = entry_start; 208 if (output > start) { 209 /* remove trailing ':' */ 210 output--; 211 vg_assert(*output == ':'); 212 } 213 } 214 215 /* pad out the left-overs with '\0' */ 216 while(output < varp) 217 *output++ = '\0'; 218 } 219 220 221 // Removes all the Valgrind-added stuff from the passed environment. Used 222 // when starting child processes, so they don't see that added stuff. 223 void VG_(env_remove_valgrind_env_stuff)(HChar** envp) 224 { 225 226 #if defined(VGO_darwin) 227 228 // Environment cleanup is also handled during parent launch 229 // in vg_preloaded.c:vg_cleanup_env(). 230 231 #endif 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 envp[i] = VG_(arena_strdup)(VG_AR_CORE, "libcproc.erves.1", envp[i]); 247 ld_preload_str = &envp[i][11]; 248 } 249 if (VG_(strncmp)(envp[i], "LD_LIBRARY_PATH=", 16) == 0) { 250 envp[i] = VG_(arena_strdup)(VG_AR_CORE, "libcproc.erves.2", envp[i]); 251 ld_library_path_str = &envp[i][16]; 252 } 253 if (VG_(strncmp)(envp[i], "DYLD_INSERT_LIBRARIES=", 22) == 0) { 254 envp[i] = VG_(arena_strdup)(VG_AR_CORE, "libcproc.erves.3", envp[i]); 255 dyld_insert_libraries_str = &envp[i][22]; 256 } 257 } 258 259 buf = VG_(arena_malloc)(VG_AR_CORE, "libcproc.erves.4", 260 VG_(strlen)(VG_(libdir)) + 20); 261 262 // Remove Valgrind-specific entries from LD_*. 263 VG_(sprintf)(buf, "%s*/vgpreload_*.so", VG_(libdir)); 264 mash_colon_env(ld_preload_str, buf); 265 mash_colon_env(dyld_insert_libraries_str, buf); 266 VG_(sprintf)(buf, "%s*", VG_(libdir)); 267 mash_colon_env(ld_library_path_str, buf); 268 269 // Remove VALGRIND_LAUNCHER variable. 270 VG_(env_unsetenv)(envp, VALGRIND_LAUNCHER); 271 272 // Remove DYLD_SHARED_REGION variable. 273 VG_(env_unsetenv)(envp, "DYLD_SHARED_REGION"); 274 275 // XXX if variable becomes empty, remove it completely? 276 277 VG_(arena_free)(VG_AR_CORE, buf); 278 } 279 280 /* --------------------------------------------------------------------- 281 Various important syscall wrappers 282 ------------------------------------------------------------------ */ 283 284 Int VG_(waitpid)(Int pid, Int *status, Int options) 285 { 286 # if defined(VGO_linux) 287 SysRes res = VG_(do_syscall4)(__NR_wait4, 288 pid, (UWord)status, options, 0); 289 return sr_isError(res) ? -1 : sr_Res(res); 290 # elif defined(VGO_darwin) 291 SysRes res = VG_(do_syscall4)(__NR_wait4_nocancel, 292 pid, (UWord)status, options, 0); 293 return sr_isError(res) ? -1 : sr_Res(res); 294 # else 295 # error Unknown OS 296 # endif 297 } 298 299 /* clone the environment */ 300 HChar **VG_(env_clone) ( HChar **oldenv ) 301 { 302 HChar **oldenvp; 303 HChar **newenvp; 304 HChar **newenv; 305 Int envlen; 306 307 vg_assert(oldenv); 308 for (oldenvp = oldenv; oldenvp && *oldenvp; oldenvp++); 309 310 envlen = oldenvp - oldenv + 1; 311 312 newenv = VG_(arena_malloc)(VG_AR_CORE, "libcproc.ec.1", 313 envlen * sizeof(HChar *)); 314 315 oldenvp = oldenv; 316 newenvp = newenv; 317 318 while (oldenvp && *oldenvp) { 319 *newenvp++ = *oldenvp++; 320 } 321 322 *newenvp = *oldenvp; 323 324 return newenv; 325 } 326 327 void VG_(execv) ( const HChar* filename, HChar** argv ) 328 { 329 HChar** envp; 330 SysRes res; 331 332 /* restore the DATA rlimit for the child */ 333 VG_(setrlimit)(VKI_RLIMIT_DATA, &VG_(client_rlimit_data)); 334 335 envp = VG_(env_clone)(VG_(client_envp)); 336 VG_(env_remove_valgrind_env_stuff)( envp ); 337 338 res = VG_(do_syscall3)(__NR_execve, 339 (UWord)filename, (UWord)argv, (UWord)envp); 340 341 VG_(printf)("EXEC failed, errno = %lld\n", (Long)sr_Err(res)); 342 } 343 344 /* Return -1 if error, else 0. NOTE does not indicate return code of 345 child! */ 346 Int VG_(system) ( const HChar* cmd ) 347 { 348 Int pid; 349 if (cmd == NULL) 350 return 1; 351 pid = VG_(fork)(); 352 if (pid < 0) 353 return -1; 354 if (pid == 0) { 355 /* child */ 356 const HChar* argv[4] = { "/bin/sh", "-c", cmd, 0 }; 357 VG_(execv)(argv[0], (HChar **)argv); 358 359 /* If we're still alive here, execv failed. */ 360 VG_(exit)(1); 361 } else { 362 /* parent */ 363 /* We have to set SIGCHLD to its default behaviour in order that 364 VG_(waitpid) works (at least on AIX). According to the Linux 365 man page for waitpid: 366 367 POSIX.1-2001 specifies that if the disposition of SIGCHLD is 368 set to SIG_IGN or the SA_NOCLDWAIT flag is set for SIGCHLD 369 (see sigaction(2)), then children that terminate do not 370 become zombies and a call to wait() or waitpid() will block 371 until all children have terminated, and then fail with errno 372 set to ECHILD. (The original POSIX standard left the 373 behaviour of setting SIGCHLD to SIG_IGN unspecified.) 374 */ 375 Int ir, zzz; 376 vki_sigaction_toK_t sa, sa2; 377 vki_sigaction_fromK_t saved_sa; 378 VG_(memset)( &sa, 0, sizeof(sa) ); 379 VG_(sigemptyset)(&sa.sa_mask); 380 sa.ksa_handler = VKI_SIG_DFL; 381 sa.sa_flags = 0; 382 ir = VG_(sigaction)(VKI_SIGCHLD, &sa, &saved_sa); 383 vg_assert(ir == 0); 384 385 zzz = VG_(waitpid)(pid, NULL, 0); 386 387 VG_(convert_sigaction_fromK_to_toK)( &saved_sa, &sa2 ); 388 ir = VG_(sigaction)(VKI_SIGCHLD, &sa2, NULL); 389 vg_assert(ir == 0); 390 return zzz == -1 ? -1 : 0; 391 } 392 } 393 394 /* --------------------------------------------------------------------- 395 Resource limits 396 ------------------------------------------------------------------ */ 397 398 /* Support for getrlimit. */ 399 Int VG_(getrlimit) (Int resource, struct vki_rlimit *rlim) 400 { 401 SysRes res = VG_(mk_SysRes_Error)(VKI_ENOSYS); 402 /* res = getrlimit( resource, rlim ); */ 403 # ifdef __NR_ugetrlimit 404 res = VG_(do_syscall2)(__NR_ugetrlimit, resource, (UWord)rlim); 405 # endif 406 if (sr_isError(res) && sr_Err(res) == VKI_ENOSYS) 407 res = VG_(do_syscall2)(__NR_getrlimit, resource, (UWord)rlim); 408 return sr_isError(res) ? -1 : sr_Res(res); 409 } 410 411 412 /* Support for setrlimit. */ 413 Int VG_(setrlimit) (Int resource, const struct vki_rlimit *rlim) 414 { 415 SysRes res; 416 /* res = setrlimit( resource, rlim ); */ 417 res = VG_(do_syscall2)(__NR_setrlimit, resource, (UWord)rlim); 418 return sr_isError(res) ? -1 : sr_Res(res); 419 } 420 421 /* Support for prctl. */ 422 Int VG_(prctl) (Int option, 423 ULong arg2, ULong arg3, ULong arg4, ULong arg5) 424 { 425 SysRes res = VG_(mk_SysRes_Error)(VKI_ENOSYS); 426 # if defined(VGO_linux) 427 /* res = prctl( option, arg2, arg3, arg4, arg5 ); */ 428 res = VG_(do_syscall5)(__NR_prctl, (UWord) option, 429 (UWord) arg2, (UWord) arg3, (UWord) arg4, 430 (UWord) arg5); 431 # endif 432 433 return sr_isError(res) ? -1 : sr_Res(res); 434 } 435 436 /* --------------------------------------------------------------------- 437 pids, etc 438 ------------------------------------------------------------------ */ 439 440 Int VG_(gettid)(void) 441 { 442 # if defined(VGO_linux) 443 SysRes res = VG_(do_syscall0)(__NR_gettid); 444 445 if (sr_isError(res) && sr_Res(res) == VKI_ENOSYS) { 446 HChar pid[16]; 447 /* 448 * The gettid system call does not exist. The obvious assumption 449 * to make at this point would be that we are running on an older 450 * system where the getpid system call actually returns the ID of 451 * the current thread. 452 * 453 * Unfortunately it seems that there are some systems with a kernel 454 * where getpid has been changed to return the ID of the thread group 455 * leader but where the gettid system call has not yet been added. 456 * 457 * So instead of calling getpid here we use readlink to see where 458 * the /proc/self link is pointing... 459 */ 460 461 # if defined(VGP_arm64_linux) 462 res = VG_(do_syscall4)(__NR_readlinkat, VKI_AT_FDCWD, 463 (UWord)"/proc/self", 464 (UWord)pid, sizeof(pid)); 465 # else 466 res = VG_(do_syscall3)(__NR_readlink, (UWord)"/proc/self", 467 (UWord)pid, sizeof(pid)); 468 # endif 469 if (!sr_isError(res) && sr_Res(res) > 0) { 470 HChar* s; 471 pid[sr_Res(res)] = '\0'; 472 res = VG_(mk_SysRes_Success)( VG_(strtoll10)(pid, &s) ); 473 if (*s != '\0') { 474 VG_(message)(Vg_DebugMsg, 475 "Warning: invalid file name linked to by /proc/self: %s\n", 476 pid); 477 } 478 } 479 } 480 481 return sr_Res(res); 482 483 # elif defined(VGO_darwin) 484 // Darwin's gettid syscall is something else. 485 // Use Mach thread ports for lwpid instead. 486 return mach_thread_self(); 487 488 # else 489 # error "Unknown OS" 490 # endif 491 } 492 493 /* You'd be amazed how many places need to know the current pid. */ 494 Int VG_(getpid) ( void ) 495 { 496 /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ 497 return sr_Res( VG_(do_syscall0)(__NR_getpid) ); 498 } 499 500 Int VG_(getpgrp) ( void ) 501 { 502 /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ 503 return sr_Res( VG_(do_syscall0)(__NR_getpgrp) ); 504 } 505 506 Int VG_(getppid) ( void ) 507 { 508 /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ 509 return sr_Res( VG_(do_syscall0)(__NR_getppid) ); 510 } 511 512 Int VG_(geteuid) ( void ) 513 { 514 /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ 515 # if defined(__NR_geteuid32) 516 // We use the 32-bit version if it's supported. Otherwise, IDs greater 517 // than 65536 cause problems, as bug #151209 showed. 518 return sr_Res( VG_(do_syscall0)(__NR_geteuid32) ); 519 # else 520 return sr_Res( VG_(do_syscall0)(__NR_geteuid) ); 521 # endif 522 } 523 524 Int VG_(getegid) ( void ) 525 { 526 /* ASSUMES SYSCALL ALWAYS SUCCEEDS */ 527 # if defined(__NR_getegid32) 528 // We use the 32-bit version if it's supported. Otherwise, IDs greater 529 // than 65536 cause problems, as bug #151209 showed. 530 return sr_Res( VG_(do_syscall0)(__NR_getegid32) ); 531 # else 532 return sr_Res( VG_(do_syscall0)(__NR_getegid) ); 533 # endif 534 } 535 536 /* Get supplementary groups into list[0 .. size-1]. Returns the 537 number of groups written, or -1 if error. Note that in order to be 538 portable, the groups are 32-bit unsigned ints regardless of the 539 platform. */ 540 Int VG_(getgroups)( Int size, UInt* list ) 541 { 542 # if defined(VGP_x86_linux) || defined(VGP_ppc32_linux) \ 543 || defined(VGP_mips64_linux) 544 Int i; 545 SysRes sres; 546 UShort list16[64]; 547 if (size < 0) return -1; 548 if (size > 64) size = 64; 549 sres = VG_(do_syscall2)(__NR_getgroups, size, (Addr)list16); 550 if (sr_isError(sres)) 551 return -1; 552 if (sr_Res(sres) > size) 553 return -1; 554 for (i = 0; i < sr_Res(sres); i++) 555 list[i] = (UInt)list16[i]; 556 return sr_Res(sres); 557 558 # elif defined(VGP_amd64_linux) || defined(VGP_ppc64_linux) \ 559 || defined(VGP_arm_linux) \ 560 || defined(VGO_darwin) || defined(VGP_s390x_linux) \ 561 || defined(VGP_mips32_linux) || defined(VGP_arm64_linux) 562 SysRes sres; 563 sres = VG_(do_syscall2)(__NR_getgroups, size, (Addr)list); 564 if (sr_isError(sres)) 565 return -1; 566 return sr_Res(sres); 567 568 # else 569 # error "VG_(getgroups): needs implementation on this platform" 570 # endif 571 } 572 573 /* --------------------------------------------------------------------- 574 Process tracing 575 ------------------------------------------------------------------ */ 576 577 Int VG_(ptrace) ( Int request, Int pid, void *addr, void *data ) 578 { 579 SysRes res; 580 res = VG_(do_syscall4)(__NR_ptrace, request, pid, (UWord)addr, (UWord)data); 581 if (sr_isError(res)) 582 return -1; 583 return sr_Res(res); 584 } 585 586 /* --------------------------------------------------------------------- 587 Fork 588 ------------------------------------------------------------------ */ 589 590 Int VG_(fork) ( void ) 591 { 592 # if defined(VGO_linux) 593 SysRes res; 594 res = VG_(do_syscall0)(__NR_fork); 595 if (sr_isError(res)) 596 return -1; 597 return sr_Res(res); 598 599 # elif defined(VGO_darwin) 600 SysRes res; 601 res = VG_(do_syscall0)(__NR_fork); /* __NR_fork is UX64 */ 602 if (sr_isError(res)) 603 return -1; 604 /* on success: wLO = child pid; wHI = 1 for child, 0 for parent */ 605 if (sr_ResHI(res) != 0) { 606 return 0; /* this is child: return 0 instead of child pid */ 607 } 608 return sr_Res(res); 609 610 # else 611 # error "Unknown OS" 612 # endif 613 } 614 615 /* --------------------------------------------------------------------- 616 Timing stuff 617 ------------------------------------------------------------------ */ 618 619 UInt VG_(read_millisecond_timer) ( void ) 620 { 621 /* 'now' and 'base' are in microseconds */ 622 static ULong base = 0; 623 ULong now; 624 625 # if defined(VGO_linux) 626 { SysRes res; 627 struct vki_timespec ts_now; 628 res = VG_(do_syscall2)(__NR_clock_gettime, VKI_CLOCK_MONOTONIC, 629 (UWord)&ts_now); 630 if (sr_isError(res) == 0) { 631 now = ts_now.tv_sec * 1000000ULL + ts_now.tv_nsec / 1000; 632 } else { 633 struct vki_timeval tv_now; 634 res = VG_(do_syscall2)(__NR_gettimeofday, (UWord)&tv_now, (UWord)NULL); 635 vg_assert(! sr_isError(res)); 636 now = tv_now.tv_sec * 1000000ULL + tv_now.tv_usec; 637 } 638 } 639 640 # elif defined(VGO_darwin) 641 // Weird: it seems that gettimeofday() doesn't fill in the timeval, but 642 // rather returns the tv_sec as the low 32 bits of the result and the 643 // tv_usec as the high 32 bits of the result. (But the timeval cannot be 644 // NULL!) See bug 200990. 645 { SysRes res; 646 struct vki_timeval tv_now = { 0, 0 }; 647 res = VG_(do_syscall2)(__NR_gettimeofday, (UWord)&tv_now, (UWord)NULL); 648 vg_assert(! sr_isError(res)); 649 now = sr_Res(res) * 1000000ULL + sr_ResHI(res); 650 } 651 652 # else 653 # error "Unknown OS" 654 # endif 655 656 /* COMMON CODE */ 657 if (base == 0) 658 base = now; 659 660 return (now - base) / 1000; 661 } 662 663 664 /* --------------------------------------------------------------------- 665 atfork() 666 ------------------------------------------------------------------ */ 667 668 struct atfork { 669 vg_atfork_t pre; 670 vg_atfork_t parent; 671 vg_atfork_t child; 672 }; 673 674 #define VG_MAX_ATFORK 10 675 676 static struct atfork atforks[VG_MAX_ATFORK]; 677 static Int n_atfork = 0; 678 679 void VG_(atfork)(vg_atfork_t pre, vg_atfork_t parent, vg_atfork_t child) 680 { 681 Int i; 682 683 for (i = 0; i < n_atfork; i++) { 684 if (atforks[i].pre == pre && 685 atforks[i].parent == parent && 686 atforks[i].child == child) 687 return; 688 } 689 690 if (n_atfork >= VG_MAX_ATFORK) 691 VG_(core_panic)( 692 "Too many VG_(atfork) handlers requested: raise VG_MAX_ATFORK"); 693 694 atforks[n_atfork].pre = pre; 695 atforks[n_atfork].parent = parent; 696 atforks[n_atfork].child = child; 697 698 n_atfork++; 699 } 700 701 void VG_(do_atfork_pre)(ThreadId tid) 702 { 703 Int i; 704 705 for (i = 0; i < n_atfork; i++) 706 if (atforks[i].pre != NULL) 707 (*atforks[i].pre)(tid); 708 } 709 710 void VG_(do_atfork_parent)(ThreadId tid) 711 { 712 Int i; 713 714 for (i = 0; i < n_atfork; i++) 715 if (atforks[i].parent != NULL) 716 (*atforks[i].parent)(tid); 717 } 718 719 void VG_(do_atfork_child)(ThreadId tid) 720 { 721 Int i; 722 723 for (i = 0; i < n_atfork; i++) 724 if (atforks[i].child != NULL) 725 (*atforks[i].child)(tid); 726 } 727 728 729 /* --------------------------------------------------------------------- 730 icache invalidation 731 ------------------------------------------------------------------ */ 732 733 void VG_(invalidate_icache) ( void *ptr, SizeT nbytes ) 734 { 735 if (nbytes == 0) return; // nothing to do 736 737 // Get cache info 738 VexArchInfo vai; 739 VG_(machine_get_VexArchInfo)(NULL, &vai); 740 741 // If I-caches are coherent, nothing needs to be done here 742 if (vai.hwcache_info.icaches_maintain_coherence) return; 743 744 # if defined(VGA_ppc32) || defined(VGA_ppc64) 745 Addr startaddr = (Addr) ptr; 746 Addr endaddr = startaddr + nbytes; 747 Addr cls; 748 Addr addr; 749 750 VG_(machine_get_VexArchInfo)( NULL, &vai ); 751 cls = vai.ppc_icache_line_szB; 752 753 /* Stay sane .. */ 754 vg_assert(cls == 16 || cls == 32 || cls == 64 || cls == 128); 755 756 startaddr &= ~(cls - 1); 757 for (addr = startaddr; addr < endaddr; addr += cls) { 758 __asm__ __volatile__("dcbst 0,%0" : : "r" (addr)); 759 } 760 __asm__ __volatile__("sync"); 761 for (addr = startaddr; addr < endaddr; addr += cls) { 762 __asm__ __volatile__("icbi 0,%0" : : "r" (addr)); 763 } 764 __asm__ __volatile__("sync; isync"); 765 766 # elif defined(VGP_arm_linux) 767 /* ARM cache flushes are privileged, so we must defer to the kernel. */ 768 Addr startaddr = (Addr) ptr; 769 Addr endaddr = startaddr + nbytes; 770 VG_(do_syscall2)(__NR_ARM_cacheflush, startaddr, endaddr); 771 772 # elif defined(VGP_arm64_linux) 773 // This arm64_linux section of this function VG_(invalidate_icache) 774 // is copied from 775 // https://github.com/armvixl/vixl/blob/master/src/a64/cpu-a64.cc 776 // which has the following copyright notice: 777 /* 778 Copyright 2013, ARM Limited 779 All rights reserved. 780 781 Redistribution and use in source and binary forms, with or without 782 modification, are permitted provided that the following conditions are met: 783 784 * Redistributions of source code must retain the above copyright notice, 785 this list of conditions and the following disclaimer. 786 * Redistributions in binary form must reproduce the above copyright notice, 787 this list of conditions and the following disclaimer in the documentation 788 and/or other materials provided with the distribution. 789 * Neither the name of ARM Limited nor the names of its contributors may be 790 used to endorse or promote products derived from this software without 791 specific prior written permission. 792 793 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND 794 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 795 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 796 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE 797 FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 798 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 799 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 800 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 801 OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 802 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 803 */ 804 805 // Ask what the I and D line sizes are 806 UInt cache_type_register; 807 // Copy the content of the cache type register to a core register. 808 __asm__ __volatile__ ("mrs %[ctr], ctr_el0" // NOLINT 809 : [ctr] "=r" (cache_type_register)); 810 811 const Int kDCacheLineSizeShift = 16; 812 const Int kICacheLineSizeShift = 0; 813 const UInt kDCacheLineSizeMask = 0xf << kDCacheLineSizeShift; 814 const UInt kICacheLineSizeMask = 0xf << kICacheLineSizeShift; 815 816 // The cache type register holds the size of the I and D caches as a power of 817 // two. 818 const UInt dcache_line_size_power_of_two = 819 (cache_type_register & kDCacheLineSizeMask) >> kDCacheLineSizeShift; 820 const UInt icache_line_size_power_of_two = 821 (cache_type_register & kICacheLineSizeMask) >> kICacheLineSizeShift; 822 823 const UInt dcache_line_size_ = 4 * (1 << dcache_line_size_power_of_two); 824 const UInt icache_line_size_ = 4 * (1 << icache_line_size_power_of_two); 825 826 Addr start = (Addr)ptr; 827 // Sizes will be used to generate a mask big enough to cover a pointer. 828 Addr dsize = (Addr)dcache_line_size_; 829 Addr isize = (Addr)icache_line_size_; 830 831 // Cache line sizes are always a power of 2. 832 Addr dstart = start & ~(dsize - 1); 833 Addr istart = start & ~(isize - 1); 834 Addr end = start + nbytes; 835 836 __asm__ __volatile__ ( 837 // Clean every line of the D cache containing the target data. 838 "0: \n\t" 839 // dc : Data Cache maintenance 840 // c : Clean 841 // va : by (Virtual) Address 842 // u : to the point of Unification 843 // The point of unification for a processor is the point by which the 844 // instruction and data caches are guaranteed to see the same copy of a 845 // memory location. See ARM DDI 0406B page B2-12 for more information. 846 "dc cvau, %[dline] \n\t" 847 "add %[dline], %[dline], %[dsize] \n\t" 848 "cmp %[dline], %[end] \n\t" 849 "b.lt 0b \n\t" 850 // Barrier to make sure the effect of the code above is visible to the rest 851 // of the world. 852 // dsb : Data Synchronisation Barrier 853 // ish : Inner SHareable domain 854 // The point of unification for an Inner Shareable shareability domain is 855 // the point by which the instruction and data caches of all the processors 856 // in that Inner Shareable shareability domain are guaranteed to see the 857 // same copy of a memory location. See ARM DDI 0406B page B2-12 for more 858 // information. 859 "dsb ish \n\t" 860 // Invalidate every line of the I cache containing the target data. 861 "1: \n\t" 862 // ic : instruction cache maintenance 863 // i : invalidate 864 // va : by address 865 // u : to the point of unification 866 "ic ivau, %[iline] \n\t" 867 "add %[iline], %[iline], %[isize] \n\t" 868 "cmp %[iline], %[end] \n\t" 869 "b.lt 1b \n\t" 870 // Barrier to make sure the effect of the code above is visible to the rest 871 // of the world. 872 "dsb ish \n\t" 873 // Barrier to ensure any prefetching which happened before this code is 874 // discarded. 875 // isb : Instruction Synchronisation Barrier 876 "isb \n\t" 877 : [dline] "+r" (dstart), 878 [iline] "+r" (istart) 879 : [dsize] "r" (dsize), 880 [isize] "r" (isize), 881 [end] "r" (end) 882 // This code does not write to memory but without the dependency gcc might 883 // move this code before the code is generated. 884 : "cc", "memory" 885 ); 886 887 # elif defined(VGA_mips32) || defined(VGA_mips64) 888 SysRes sres = VG_(do_syscall3)(__NR_cacheflush, (UWord) ptr, 889 (UWord) nbytes, (UWord) 3); 890 vg_assert( sres._isError == 0 ); 891 892 # endif 893 } 894 895 896 /* --------------------------------------------------------------------- 897 dcache flushing 898 ------------------------------------------------------------------ */ 899 900 void VG_(flush_dcache) ( void *ptr, SizeT nbytes ) 901 { 902 /* Currently this is only required on ARM64. */ 903 # if defined(VGA_arm64) 904 Addr startaddr = (Addr) ptr; 905 Addr endaddr = startaddr + nbytes; 906 Addr cls; 907 Addr addr; 908 909 ULong ctr_el0; 910 __asm__ __volatile__ ("mrs %0, ctr_el0" : "=r"(ctr_el0)); 911 cls = 4 * (1ULL << (0xF & (ctr_el0 >> 16))); 912 913 /* Stay sane .. */ 914 vg_assert(cls == 64); 915 916 startaddr &= ~(cls - 1); 917 for (addr = startaddr; addr < endaddr; addr += cls) { 918 __asm__ __volatile__("dc cvau, %0" : : "r" (addr)); 919 } 920 __asm__ __volatile__("dsb ish"); 921 # endif 922 } 923 924 /*--------------------------------------------------------------------*/ 925 /*--- end ---*/ 926 /*--------------------------------------------------------------------*/ 927
