coregrind/m_libcproc.c

   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) 2000-2017 Julian Seward
  11       jseward@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, see <http://www.gnu.org/licenses/>.
  25
  26    The GNU General Public License is contained in the file COPYING.
  27 */
  28
  29 #include "pub_core_basics.h"
  30 #include "pub_core_machine.h"    // For VG_(machine_get_VexArchInfo)
  31 #include "pub_core_vki.h"
  32 #include "pub_core_vkiscnums.h"
  33 #include "pub_core_libcbase.h"
  34 #include "pub_core_libcassert.h"
  35 #include "pub_core_libcfile.h"
  36 #include "pub_core_libcprint.h"
  37 #include "pub_core_libcproc.h"
  38 #include "pub_core_libcsignal.h"
  39 #include "pub_core_seqmatch.h"
  40 #include "pub_core_mallocfree.h"
  41 #include "pub_core_signals.h"
  42 #include "pub_core_syscall.h"
  43 #include "pub_core_xarray.h"
  44 #include "pub_core_clientstate.h"
  45 #include "pub_core_debuglog.h"   // VG_(debugLog)
  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) || defined(VGO_freebsd)
  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) || defined(VGO_freebsd)
 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    envp = VG_(env_clone)(VG_(client_envp));
 454    VG_(env_remove_valgrind_env_stuff)( envp, True /*ro_strings*/, NULL );
 455
 456    res = VG_(do_syscall3)(__NR_execve,
 457                           (UWord)filename, (UWord)argv, (UWord)envp);
 458
 459    VG_(printf)("EXEC failed, errno = %lld\n", (Long)sr_Err(res));
 460 }
 461
 462 /* Spawns a new child. Uses either spawn syscall or fork+execv combo. */
 463 Int VG_(spawn) ( const HChar *filename, const HChar **argv )
 464 {
 465    vg_assert(filename != NULL);
 466    vg_assert(argv != NULL);
 467
 468 #  if defined(VGO_solaris) && defined(SOLARIS_SPAWN_SYSCALL)
 469    HChar **envp = VG_(env_clone)(VG_(client_envp));
 470    for (HChar **p = envp; *p != NULL; p++) {
 471       *p = VG_(strdup)("libcproc.s.1", *p);
 472    }
 473    VG_(env_remove_valgrind_env_stuff)(envp, /* ro_strings */ False, VG_(free));
 474
 475    /* Now combine argv and argp into argenv. */
 476    SizeT argenv_size = 1 + 1;
 477    for (const HChar **p = argv; *p != NULL; p++) {
 478       argenv_size += VG_(strlen)(*p) + 2;
 479    }
 480    for (HChar **p = envp; *p != NULL; p++) {
 481       argenv_size += VG_(strlen)(*p) + 2;
 482    }
 483
 484    HChar *argenv = VG_(malloc)("libcproc.s.2", argenv_size);
 485    HChar *current = argenv;
 486 #  define COPY_CHAR_TO_ARGENV(dst, character)  \
 487       do {                                     \
 488          *(dst) = character;                   \
 489          (dst) += 1;                           \
 490       } while (0)
 491 #  define COPY_STRING_TO_ARGENV(dst, src)        \
 492       do {                                       \
 493          COPY_CHAR_TO_ARGENV(dst, '\1');         \
 494          SizeT src_len = VG_(strlen)((src)) + 1; \
 495          VG_(memcpy)((dst), (src), src_len);     \
 496          (dst) += src_len;                       \
 497       } while (0)
 498
 499    for (const HChar **p = argv; *p != NULL; p++) {
 500       COPY_STRING_TO_ARGENV(current, *p);
 501    }
 502    COPY_CHAR_TO_ARGENV(current, '\0');
 503    for (HChar **p = envp; *p != NULL; p++) {
 504       COPY_STRING_TO_ARGENV(current, *p);
 505    }
 506    COPY_CHAR_TO_ARGENV(current, '\0');
 507    vg_assert(current == argenv + argenv_size);
 508 #  undef COPY_CHAR_TO_ARGENV
 509 #  undef COPY_STRING_TOARGENV
 510
 511    SysRes res = VG_(do_syscall5)(__NR_spawn, (UWord) filename, (UWord) NULL, 0,
 512                                  (UWord) argenv, argenv_size);
 513
 514    VG_(free)(argenv);
 515    for (HChar **p = envp; *p != NULL; p++) {
 516       VG_(free)(*p);
 517    }
 518    VG_(free)(envp);
 519
 520    if (sr_isError(res))
 521       return -1;
 522    return sr_Res(res);
 523
 524 #  else
 525
 526    Int pid = VG_(fork)();
 527    if (pid < 0)
 528       return -1;
 529    if (pid == 0) {
 530       /* child */
 531       VG_(execv)(argv[0], argv);
 532
 533       /* If we're still alive here, execv failed. */
 534       VG_(exit)(1);
 535    } else {
 536       return pid;
 537    }
 538 #  endif /* VGO_solaris && SOLARIS_SPAWN_SYSCALL */
 539 }
 540
 541 /* Return -1 if error, else 0.  NOTE does not indicate return code of
 542    child! */
 543 Int VG_(system) ( const HChar* cmd )
 544 {
 545    Int pid;
 546    if (cmd == NULL)
 547       return 1;
 548
 549    const HChar *argv[4] = { "/bin/sh", "-c", cmd, 0 };
 550    pid = VG_(spawn)(argv[0], argv);
 551    if (pid < 0)
 552       return -1;
 553
 554    vg_assert(pid > 0);
 555    /* parent */
 556    /* We have to set SIGCHLD to its default behaviour in order that
 557       VG_(waitpid) works (at least on AIX).  According to the Linux
 558       man page for waitpid:
 559
 560       POSIX.1-2001 specifies that if the disposition of SIGCHLD is
 561       set to SIG_IGN or the SA_NOCLDWAIT flag is set for SIGCHLD
 562       (see sigaction(2)), then children that terminate do not
 563       become zombies and a call to wait() or waitpid() will block
 564       until all children have terminated, and then fail with errno
 565       set to ECHILD.  (The original POSIX standard left the
 566       behaviour of setting SIGCHLD to SIG_IGN unspecified.)
 567    */
 568    Int ir, zzz;
 569    vki_sigaction_toK_t sa, sa2;
 570    vki_sigaction_fromK_t saved_sa;
 571    VG_(memset)( &sa, 0, sizeof(sa) );
 572    VG_(sigemptyset)(&sa.sa_mask);
 573    sa.ksa_handler = VKI_SIG_DFL;
 574    sa.sa_flags    = 0;
 575    ir = VG_(sigaction)(VKI_SIGCHLD, &sa, &saved_sa);
 576    vg_assert(ir == 0);
 577
 578    zzz = VG_(waitpid)(pid, NULL, 0);
 579
 580    VG_(convert_sigaction_fromK_to_toK)( &saved_sa, &sa2 );
 581    ir = VG_(sigaction)(VKI_SIGCHLD, &sa2, NULL);
 582    vg_assert(ir == 0);
 583    return zzz == -1 ? -1 : 0;
 584 }
 585
 586 Int VG_(sysctl)(Int *name, UInt namelen, void *oldp, SizeT *oldlenp, const void *newp, SizeT newlen)
 587 {
 588    SysRes res;
 589 #  if defined(VGO_darwin) || defined(VGO_freebsd)
 590    res = VG_(do_syscall6)(__NR___sysctl,
 591                            (UWord)name, namelen, (UWord)oldp, (UWord)oldlenp, (UWord)newp, newlen);
 592 #  else
 593    res = VG_(mk_SysRes_Error)(VKI_ENOSYS);
 594 #  endif
 595    return sr_isError(res) ? -1 : sr_Res(res);
 596 }
 597
 598 /* ---------------------------------------------------------------------
 599    Resource limits
 600    ------------------------------------------------------------------ */
 601
 602 /* Support for getrlimit. */
 603 Int VG_(getrlimit) (Int resource, struct vki_rlimit *rlim)
 604 {
 605    SysRes res;
 606    /* res = getrlimit( resource, rlim ); */
 607
 608 #  if defined(__NR_prlimit64) && defined(VKI_RLIM_INFINITY) && defined(VKI_RLIM64_INFINITY)
 609    struct vki_rlimit64 new_rlimit;
 610    res = VG_(do_syscall4)(__NR_prlimit64, 0, resource, 0, (UWord)&new_rlimit);
 611    if (!sr_isError(res)) {
 612       if (new_rlimit.rlim_cur == VKI_RLIM_INFINITY)
 613          new_rlimit.rlim_cur = VKI_RLIM64_INFINITY;
 614       if (new_rlimit.rlim_max == VKI_RLIM_INFINITY)
 615          new_rlimit.rlim_max = VKI_RLIM64_INFINITY;
 616       rlim->rlim_cur = new_rlimit.rlim_cur;
 617       rlim->rlim_max = new_rlimit.rlim_max;
 618       return sr_Res(res);
 619    }
 620    if (sr_Err(res) != VKI_ENOSYS) return -1;
 621 #  endif
 622
 623 #  ifdef __NR_ugetrlimit
 624    res = VG_(do_syscall2)(__NR_ugetrlimit, resource, (UWord)rlim);
 625    if (!sr_isError(res)) return sr_Res(res);
 626    if (sr_Err(res) != VKI_ENOSYS) return -1;
 627 #  endif
 628
 629 #  ifdef __NR_getrlimit
 630    res = VG_(do_syscall2)(__NR_getrlimit, resource, (UWord)rlim);
 631    if (!sr_isError(res)) return sr_Res(res);
 632 #  endif
 633
 634    return -1;
 635 }
 636
 637 /* Support for setrlimit. */
 638 Int VG_(setrlimit) (Int resource, const struct vki_rlimit *rlim)
 639 {
 640    SysRes res;
 641    /* res = setrlimit( resource, rlim ); */
 642
 643 #  ifdef __NR_prlimit64
 644    struct vki_rlimit64 new_rlimit;
 645    new_rlimit.rlim_cur = rlim->rlim_cur;
 646    new_rlimit.rlim_max = rlim->rlim_max;
 647    res = VG_(do_syscall4)(__NR_prlimit64, 0, resource, (UWord)&new_rlimit, 0);
 648    if (!sr_isError(res)) return sr_Res(res);
 649    if (sr_Err(res) != VKI_ENOSYS) return -1;
 650 #  endif
 651
 652 #  ifdef __NR_setrlimit
 653    res = VG_(do_syscall2)(__NR_setrlimit, resource, (UWord)rlim);
 654    if (!sr_isError(res)) return sr_Res(res);
 655    if (sr_Err(res) != VKI_ENOSYS) return -1;
 656 #  endif
 657
 658    return -1;
 659 }
 660
 661 /* Support for prctl. */
 662 Int VG_(prctl) (Int option,
 663                 ULong arg2, ULong arg3, ULong arg4, ULong arg5)
 664 {
 665    SysRes res = VG_(mk_SysRes_Error)(VKI_ENOSYS);
 666 #  if defined(VGO_linux)
 667    /* res = prctl( option, arg2, arg3, arg4, arg5 ); */
 668    res = VG_(do_syscall5)(__NR_prctl, (UWord) option,
 669                           (UWord) arg2, (UWord) arg3, (UWord) arg4,
 670                           (UWord) arg5);
 671 #  endif
 672
 673    return sr_isError(res) ? -1 : sr_Res(res);
 674 }
 675
 676 /* ---------------------------------------------------------------------
 677    pids, etc
 678    ------------------------------------------------------------------ */
 679
 680 Int VG_(gettid)(void)
 681 {
 682 #  if defined(VGO_linux)
 683    SysRes res = VG_(do_syscall0)(__NR_gettid);
 684
 685    if (sr_isError(res) && sr_Res(res) == VKI_ENOSYS) {
 686       HChar pid[16];
 687       /*
 688        * The gettid system call does not exist. The obvious assumption
 689        * to make at this point would be that we are running on an older
 690        * system where the getpid system call actually returns the ID of
 691        * the current thread.
 692        *
 693        * Unfortunately it seems that there are some systems with a kernel
 694        * where getpid has been changed to return the ID of the thread group
 695        * leader but where the gettid system call has not yet been added.
 696        *
 697        * So instead of calling getpid here we use readlink to see where
 698        * the /proc/self link is pointing...
 699        */
 700
 701 #     if defined(VGP_arm64_linux) || defined(VGP_nanomips_linux)
 702       res = VG_(do_syscall4)(__NR_readlinkat, VKI_AT_FDCWD,
 703                              (UWord)"/proc/self",
 704                              (UWord)pid, sizeof(pid));
 705 #     else
 706       res = VG_(do_syscall3)(__NR_readlink, (UWord)"/proc/self",
 707                              (UWord)pid, sizeof(pid));
 708 #     endif
 709       if (!sr_isError(res) && sr_Res(res) > 0) {
 710          HChar* s;
 711          pid[sr_Res(res)] = '\0';
 712          res = VG_(mk_SysRes_Success)(  VG_(strtoll10)(pid, &s) );
 713          if (*s != '\0') {
 714             VG_(message)(Vg_DebugMsg,
 715                "Warning: invalid file name linked to by /proc/self: %s\n",
 716                pid);
 717          }
 718       }
 719    }
 720
 721    return sr_Res(res);
 722
 723 #  elif defined(VGO_freebsd)
 724    SysRes res;
 725    long tid;
 726
 727    res = VG_(do_syscall1)(__NR_thr_self, (UWord)&tid);
 728    if (sr_isError(res))
 729       tid = sr_Res(VG_(do_syscall0)(__NR_getpid));
 730    return tid;
 731
 732 #  elif defined(VGO_darwin)
 733    // Darwin's gettid syscall is something else.
 734    // Use Mach thread ports for lwpid instead.
 735    return mach_thread_self();
 736
 737 #  elif defined(VGO_solaris)
 738    SysRes res = VG_(do_syscall0)(__NR_lwp_self);
 739    return sr_Res(res);
 740
 741 #  else
 742 #    error "Unknown OS"
 743 #  endif
 744 }
 745
 746 /* You'd be amazed how many places need to know the current pid. */
 747 Int VG_(getpid) ( void )
 748 {
 749    /* ASSUMES SYSCALL ALWAYS SUCCEEDS */
 750    return sr_Res( VG_(do_syscall0)(__NR_getpid) );
 751 }
 752
 753 Int VG_(getpgrp) ( void )
 754 {
 755    /* ASSUMES SYSCALL ALWAYS SUCCEEDS */
 756 #  if defined(VGP_arm64_linux) || defined(VGP_nanomips_linux)
 757    return sr_Res( VG_(do_syscall1)(__NR_getpgid, 0) );
 758 #  elif defined(VGO_linux) || defined(VGO_darwin) || defined(VGO_freebsd)
 759    return sr_Res( VG_(do_syscall0)(__NR_getpgrp) );
 760 #  elif defined(VGO_solaris)
 761    /* Uses the shared pgrpsys syscall, 0 for the getpgrp variant. */
 762    return sr_Res( VG_(do_syscall1)(__NR_pgrpsys, 0) );
 763 #  else
 764 #    error Unknown OS
 765 #  endif
 766 }
 767
 768 Int VG_(getppid) ( void )
 769 {
 770    /* ASSUMES SYSCALL ALWAYS SUCCEEDS */
 771 #  if defined(VGO_linux) || defined(VGO_darwin) || defined(VGO_freebsd)
 772    return sr_Res( VG_(do_syscall0)(__NR_getppid) );
 773 #  elif defined(VGO_solaris)
 774    /* Uses the shared getpid/getppid syscall, val2 contains a parent pid. */
 775    return sr_ResHI( VG_(do_syscall0)(__NR_getpid) );
 776 #  else
 777 #    error Unknown OS
 778 #  endif
 779 }
 780
 781 Int VG_(geteuid) ( void )
 782 {
 783    /* ASSUMES SYSCALL ALWAYS SUCCEEDS */
 784 #  if defined(VGO_linux) || defined(VGO_darwin) || defined(VGO_freebsd)
 785    {
 786 #     if defined(__NR_geteuid32)
 787       // We use the 32-bit version if it's supported.  Otherwise, IDs greater
 788       // than 65536 cause problems, as bug #151209 showed.
 789       return sr_Res( VG_(do_syscall0)(__NR_geteuid32) );
 790 #     else
 791       return sr_Res( VG_(do_syscall0)(__NR_geteuid) );
 792 #     endif
 793    }
 794 #  elif defined(VGO_solaris)
 795    /* Uses the shared getuid/geteuid syscall, val2 contains the effective
 796       uid. */
 797    return sr_ResHI( VG_(do_syscall0)(__NR_getuid) );
 798 #  else
 799 #    error Unknown OS
 800 #  endif
 801 }
 802
 803 Int VG_(getegid) ( void )
 804 {
 805 #  if defined(VGO_linux) || defined(VGO_darwin) || defined(VGO_freebsd)
 806    /* ASSUMES SYSCALL ALWAYS SUCCEEDS */
 807 #    if defined(__NR_getegid32)
 808    // We use the 32-bit version if it's supported.  Otherwise, IDs greater
 809    // than 65536 cause problems, as bug #151209 showed.
 810    return sr_Res( VG_(do_syscall0)(__NR_getegid32) );
 811 #    else
 812    return sr_Res( VG_(do_syscall0)(__NR_getegid) );
 813 #    endif
 814
 815 #  elif defined(VGO_solaris)
 816    /* Uses the shared getgid/getegid syscall, val2 contains the effective
 817       gid. */
 818    return sr_ResHI( VG_(do_syscall0)(__NR_getgid) );
 819 #  else
 820 #    error Unknown OS
 821 #  endif
 822 }
 823
 824 /* Get supplementary groups into list[0 .. size-1].  Returns the
 825    number of groups written, or -1 if error.  Note that in order to be
 826    portable, the groups are 32-bit unsigned ints regardless of the
 827    platform.
 828    As a special case, if size == 0 the function returns the number of
 829    groups leaving list untouched. */
 830 Int VG_(getgroups)( Int size, UInt* list )
 831 {
 832    if (size < 0) return -1;
 833
 834 #  if defined(VGP_x86_linux) || defined(VGP_ppc32_linux) \
 835       || defined(VGP_mips64_linux)
 836    Int    i;
 837    SysRes sres;
 838    UShort list16[size];
 839    sres = VG_(do_syscall2)(__NR_getgroups, size, (Addr)list16);
 840    if (sr_isError(sres))
 841       return -1;
 842    if (size != 0) {
 843       for (i = 0; i < sr_Res(sres); i++)
 844          list[i] = (UInt)list16[i];
 845    }
 846    return sr_Res(sres);
 847
 848 #  elif defined(VGP_amd64_linux) || defined(VGP_arm_linux) \
 849         || defined(VGP_ppc64be_linux) || defined(VGP_ppc64le_linux)  \
 850         || defined(VGO_darwin) || defined(VGP_s390x_linux)    \
 851         || defined(VGP_mips32_linux) || defined(VGP_arm64_linux) \
 852         || defined(VGO_solaris) || defined(VGP_nanomips_linux) \
 853         || defined(VGO_freebsd)
 854    SysRes sres;
 855    sres = VG_(do_syscall2)(__NR_getgroups, size, (Addr)list);
 856    if (sr_isError(sres))
 857       return -1;
 858    return sr_Res(sres);
 859
 860 #  else
 861 #     error "VG_(getgroups): needs implementation on this platform"
 862 #  endif
 863 }
 864
 865 /* ---------------------------------------------------------------------
 866    Process tracing
 867    ------------------------------------------------------------------ */
 868
 869 Int VG_(ptrace) ( Int request, Int pid, void *addr, void *data )
 870 {
 871    SysRes res;
 872 #  if defined(VGO_linux) || defined(VGO_darwin) || defined(VGO_freebsd)
 873    res = VG_(do_syscall4)(__NR_ptrace, request, pid, (UWord)addr, (UWord)data);
 874 #  elif defined(VGO_solaris)
 875    /* There is no ptrace syscall on Solaris.  Such requests has to be
 876       implemented using the /proc interface.  Callers of VG_(ptrace) should
 877       ensure that this function is not reached on Solaris, i.e. they must
 878       provide a special code for Solaris for whatever feature they provide. */
 879    I_die_here;
 880 #  else
 881 #    error Unknown OS
 882 #  endif
 883    if (sr_isError(res))
 884       return -1;
 885    return sr_Res(res);
 886 }
 887
 888 /* ---------------------------------------------------------------------
 889    Fork
 890    ------------------------------------------------------------------ */
 891
 892 /* Record PID of a child process in order to avoid sending any SIGCHLD from
 893    it to the client.  If PID is 0 then this is the child process and it
 894    should synch with the parent to ensure it can't send any SIGCHLD before
 895    the parent has registered its PID.
 896
 897    FDS should be initialized with VG_(pipe). This function closes both
 898    file descriptors.  */
 899 static void register_sigchld_ignore ( Int pid, Int fds[2])
 900 {
 901    Int child_wait = 1;
 902    ht_ignore_node *n;
 903
 904    if (fds[0] < 0 || fds[1] < 0)
 905       return;
 906
 907    if (pid == 0) {
 908       /* Before proceeding, ensure parent has recorded child PID in map
 909          of SIGCHLD to ignore */
 910       while (child_wait == 1)
 911       {
 912          if (VG_(read)(fds[0], &child_wait, sizeof(Int)) <= 0) {
 913             VG_(message)(Vg_DebugMsg,
 914                "warning: Unable to record PID of internal process (read)\n");
 915             child_wait = 0;
 916          }
 917       }
 918
 919       VG_(close)(fds[0]);
 920       return;
 921    }
 922
 923    n = VG_(malloc)("ht.ignore.node", sizeof(ht_ignore_node));
 924    n->key = pid;
 925    if (ht_sigchld_ignore == NULL)
 926       ht_sigchld_ignore = VG_(HT_construct)("ht.sigchld.ignore");
 927    VG_(HT_add_node)(ht_sigchld_ignore, n);
 928
 929    child_wait = 0;
 930    if (VG_(write)(fds[1], &child_wait, sizeof(Int)) <= 0)
 931       VG_(message)(Vg_DebugMsg,
 932          "warning: Unable to record PID of internal process (write)\n");
 933
 934    VG_(close)(fds[1]);
 935 }
 936
 937 Int VG_(fork) ( void )
 938 {
 939    Int fds[2];
 940
 941    if (VG_(pipe)(fds) != 0) {
 942       VG_(message)(Vg_DebugMsg,
 943          "warning: Unable to record PID of internal process (pipe)\n");
 944       fds[0] = fds[1] = -1;
 945    }
 946
 947 #  if defined(VGP_arm64_linux) || defined(VGP_nanomips_linux)
 948    SysRes res;
 949    res = VG_(do_syscall5)(__NR_clone, VKI_SIGCHLD,
 950                           (UWord)NULL, (UWord)NULL, (UWord)NULL, (UWord)NULL);
 951    if (sr_isError(res))
 952       return -1;
 953    register_sigchld_ignore(sr_Res(res), fds);
 954    return sr_Res(res);
 955
 956 #  elif defined(VGO_linux) || defined(VGO_freebsd)
 957    SysRes res;
 958    res = VG_(do_syscall0)(__NR_fork);
 959    if (sr_isError(res))
 960       return -1;
 961    register_sigchld_ignore(sr_Res(res), fds);
 962    return sr_Res(res);
 963
 964 #  elif defined(VGO_darwin)
 965    SysRes res;
 966    res = VG_(do_syscall0)(__NR_fork); /* __NR_fork is UX64 */
 967    if (sr_isError(res))
 968       return -1;
 969    /* on success: wLO = child pid; wHI = 1 for child, 0 for parent */
 970    if (sr_ResHI(res) != 0) {
 971       register_sigchld_ignore(0, fds);
 972       return 0;  /* this is child: return 0 instead of child pid */
 973    }
 974    register_sigchld_ignore(sr_Res(res), fds);
 975    return sr_Res(res);
 976
 977 #  elif defined(VGO_solaris)
 978    /* Using fork() on Solaris is not really the best thing to do. Solaris
 979       does not do memory overcommitment so fork() can fail if there is not
 980       enough memory to copy the current process into a new one.
 981       Prefer to use VG_(spawn)() over VG_(fork)() + VG_(execv)(). */
 982    SysRes res;
 983    res = VG_(do_syscall2)(__NR_forksys, 0 /*subcode (fork)*/, 0 /*flags*/);
 984    if (sr_isError(res))
 985       return -1;
 986    /* On success:
 987         val = a pid of the child in the parent, a pid of the parent in the
 988               child,
 989         val2 = 0 in the parent process, 1 in the child process. */
 990    if (sr_ResHI(res) != 0) {
 991       register_sigchld_ignore(0, fds);
 992       return 0;
 993    }
 994    register_sigchld_ignore(sr_Res(res), fds);
 995    return sr_Res(res);
 996
 997 #  else
 998 #    error "Unknown OS"
 999 #  endif
1000 }
1001
1002 /* ---------------------------------------------------------------------
1003    Timing stuff
1004    ------------------------------------------------------------------ */
1005
1006 UInt VG_(read_millisecond_timer) ( void )
1007 {
1008    /* 'now' and 'base' are in microseconds */
1009    static ULong base = 0;
1010    ULong  now;
1011
1012 #  if defined(VGO_linux) || defined(VGO_solaris)
1013    { SysRes res;
1014      struct vki_timespec ts_now;
1015      res = VG_(do_syscall2)(__NR_clock_gettime, VKI_CLOCK_MONOTONIC,
1016                             (UWord)&ts_now);
1017      if (sr_isError(res) == 0) {
1018         now = ts_now.tv_sec * 1000000ULL + ts_now.tv_nsec / 1000;
1019      } else {
1020        struct vki_timeval tv_now;
1021        /* Note: On Solaris, this syscall takes only one parameter but the
1022           extra dummy one does not cause any harm. */
1023        res = VG_(do_syscall2)(__NR_gettimeofday, (UWord)&tv_now, (UWord)NULL);
1024        vg_assert(! sr_isError(res));
1025        now = tv_now.tv_sec * 1000000ULL + tv_now.tv_usec;
1026      }
1027    }
1028
1029 #  elif defined(VGO_freebsd)
1030    { SysRes res;
1031      struct vki_timeval tv_now;
1032      res = VG_(do_syscall2)(__NR_gettimeofday, (UWord)&tv_now, (UWord)NULL);
1033      vg_assert(! sr_isError(res));
1034      now = tv_now.tv_sec * 1000000ULL + tv_now.tv_usec;
1035    }
1036 #  elif defined(VGO_darwin)
1037    // Weird: it seems that gettimeofday() doesn't fill in the timeval, but
1038    // rather returns the tv_sec as the low 32 bits of the result and the
1039    // tv_usec as the high 32 bits of the result.  (But the timeval cannot be
1040    // NULL!)  See bug 200990.
1041    { SysRes res;
1042      struct vki_timeval tv_now = { 0, 0 };
1043      res = VG_(do_syscall2)(__NR_gettimeofday, (UWord)&tv_now, (UWord)NULL);
1044      vg_assert(! sr_isError(res));
1045      now = sr_Res(res) * 1000000ULL + sr_ResHI(res);
1046    }
1047
1048 #  else
1049 #    error "Unknown OS"
1050 #  endif
1051
1052    /* COMMON CODE */
1053    if (base == 0)
1054       base = now;
1055
1056    return (now - base) / 1000;
1057 }
1058
1059 #  if defined(VGO_linux) || defined(VGO_solaris) || defined(VGO_freebsd)
1060 void VG_(clock_gettime) ( struct vki_timespec *ts, vki_clockid_t clk_id )
1061 {
1062     SysRes res;
1063     res = VG_(do_syscall2)(__NR_clock_gettime, clk_id,
1064                            (UWord)ts);
1065     vg_assert (sr_isError(res) == 0);
1066 }
1067 #  elif defined(VGO_darwin)
1068   /* See pub_tool_libcproc.h */
1069 #  else
1070 #    error "Unknown OS"
1071 #  endif
1072
1073 Int VG_(gettimeofday)(struct vki_timeval *tv, struct vki_timezone *tz)
1074 {
1075    SysRes res;
1076    res = VG_(do_syscall2)(__NR_gettimeofday, (UWord)tv, (UWord)tz);
1077
1078    if (! sr_isError(res)) return 0;
1079
1080    /* Make sure, argument values are deterministic upon failure */
1081    if (tv) *tv = (struct vki_timeval){ .tv_sec = 0, .tv_usec = 0 };
1082    if (tz) *tz = (struct vki_timezone){ .tz_minuteswest = 0, .tz_dsttime = 0 };
1083
1084    return -1;
1085 }
1086
1087 UInt VG_(get_user_milliseconds)(void)
1088 {
1089    UInt res = 0;
1090 #  if defined(VGO_linux)
1091    {
1092       struct vki_rusage ru;
1093       VG_(memset)(&ru, 0, sizeof(ru));
1094       SysRes sr = VG_(do_syscall2)(__NR_getrusage, VKI_RUSAGE_SELF, (UWord)&ru);
1095       if (!sr_isError(sr)) {
1096          res = ru.ru_utime.tv_sec * 1000 + ru.ru_utime.tv_usec / 1000;
1097       }
1098    }
1099
1100 #  elif defined(VGO_solaris)
1101    {
1102       struct vki_rusage ru;
1103       VG_(memset)(&ru, 0, sizeof(ru));
1104       SysRes sr = VG_(do_syscall2)(__NR_rusagesys, VKI__RUSAGESYS_GETRUSAGE,
1105                                    (UWord) &ru);
1106       if (!sr_isError(sr)) {
1107          res = ru.ru_utime.tv_sec * 1000 + ru.ru_utime.tv_usec / 1000;
1108       }
1109    }
1110
1111 #  elif defined(VGO_freebsd)
1112    {
1113       struct vki_rusage ru;
1114       VG_(memset)(&ru, 0, sizeof(ru));
1115       SysRes sr = VG_(do_syscall2)(__NR_getrusage, VKI_RUSAGE_SELF, (UWord)&ru);
1116       if (!sr_isError(sr)) {
1117          res = ru.ru_utime.tv_sec * 1000 + ru.ru_utime.tv_usec / 1000;
1118       }
1119    }
1120
1121 #  elif defined(VGO_darwin)
1122    res = 0;
1123
1124 #  else
1125 #    error "Unknown OS"
1126 #  endif
1127
1128    return res;
1129 }
1130
1131
1132 /* ---------------------------------------------------------------------
1133    atfork()
1134    ------------------------------------------------------------------ */
1135
1136 struct atfork {
1137    vg_atfork_t  pre;
1138    vg_atfork_t  parent;
1139    vg_atfork_t  child;
1140 };
1141
1142 #define VG_MAX_ATFORK 10
1143
1144 static struct atfork atforks[VG_MAX_ATFORK];
1145 static Int n_atfork = 0;
1146
1147 void VG_(atfork)(vg_atfork_t pre, vg_atfork_t parent, vg_atfork_t child)
1148 {
1149    Int i;
1150
1151    for (i = 0; i < n_atfork; i++) {
1152       if (atforks[i].pre == pre &&
1153           atforks[i].parent == parent &&
1154           atforks[i].child == child)
1155          return;
1156    }
1157
1158    if (n_atfork >= VG_MAX_ATFORK)
1159       VG_(core_panic)(
1160          "Too many VG_(atfork) handlers requested: raise VG_MAX_ATFORK");
1161
1162    atforks[n_atfork].pre    = pre;
1163    atforks[n_atfork].parent = parent;
1164    atforks[n_atfork].child  = child;
1165
1166    n_atfork++;
1167 }
1168
1169 void VG_(do_atfork_pre)(ThreadId tid)
1170 {
1171    Int i;
1172
1173    for (i = 0; i < n_atfork; i++)
1174       if (atforks[i].pre != NULL)
1175          (*atforks[i].pre)(tid);
1176 }
1177
1178 void VG_(do_atfork_parent)(ThreadId tid)
1179 {
1180    Int i;
1181
1182    for (i = 0; i < n_atfork; i++)
1183       if (atforks[i].parent != NULL)
1184          (*atforks[i].parent)(tid);
1185 }
1186
1187 void VG_(do_atfork_child)(ThreadId tid)
1188 {
1189    Int i;
1190
1191    for (i = 0; i < n_atfork; i++)
1192       if (atforks[i].child != NULL)
1193          (*atforks[i].child)(tid);
1194 }
1195
1196 /* ---------------------------------------------------------------------
1197    FreeBSD sysctlbyname, getosreldate, is32on64
1198    ------------------------------------------------------------------ */
1199
1200 #if defined(VGO_freebsd)
1201 Int VG_(sysctlbyname)(const HChar *name, void *oldp, SizeT *oldlenp, const void *newp, SizeT newlen)
1202 {
1203    vg_assert(name);
1204 #if (FREEBSD_VERS >= FREEBSD_12_2)
1205    SysRes res = VG_(do_syscall6)(__NR___sysctlbyname, (RegWord)name, VG_(strlen)(name), (RegWord)oldp, (RegWord)oldlenp, (RegWord)newp, (RegWord)newlen);
1206    return sr_isError(res) ? -1 : sr_Res(res);
1207 #else
1208    Int oid[2];
1209    Int real_oid[10];
1210    SizeT oidlen;
1211    int error;
1212
1213    oid[0] = 0;          /* magic */
1214    oid[1] = 3;          /* undocumented */
1215    oidlen = sizeof(real_oid);
1216    error = VG_(sysctl)(oid, 2, real_oid, &oidlen, name, VG_(strlen)(name));
1217    if (error < 0)
1218       return error;
1219    oidlen /= sizeof(int);
1220    error = VG_(sysctl)(real_oid, oidlen, oldp, oldlenp, newp, newlen);
1221    return error;
1222  #endif
1223 }
1224
1225 Int VG_(getosreldate)(void)
1226 {
1227    static Int osreldate = 0;
1228    SizeT osreldatel;
1229
1230    if (osreldate == 0) {
1231       osreldatel = sizeof(osreldate);
1232       VG_(sysctlbyname)("kern.osreldate", &osreldate, &osreldatel, 0, 0);
1233    }
1234    return (osreldate);
1235 }
1236
1237 Bool VG_(is32on64)(void)
1238 {
1239 #if defined(VGP_amd64_freebsd)
1240    return False;
1241 #elif defined(VGP_x86_freebsd)
1242    SysRes res;
1243    struct vg_stat stat_buf;
1244    res = VG_(stat)("/libexec/ld-elf32.so.1", &stat_buf);
1245    if (!sr_isError(res)) {
1246       // file exists, we're running on amd64
1247       VG_(debugLog)(1, "check-os-bitness", "i386 executable on amd64 kernel\n");
1248       return True;
1249    } else {
1250       VG_(debugLog)(1, "check-os-bitness", "i386 executable on i386 kernel\n");
1251       return False;
1252    }
1253 #else
1254 #  error Unknown platform
1255 #endif
1256 }
1257 #endif
1258
1259 /* ---------------------------------------------------------------------
1260    icache invalidation
1261    ------------------------------------------------------------------ */
1262
1263 void VG_(invalidate_icache) ( void *ptr, SizeT nbytes )
1264 {
1265    if (nbytes == 0) return;    // nothing to do
1266
1267    // Get cache info
1268    VexArchInfo vai;
1269    VG_(machine_get_VexArchInfo)(NULL, &vai);
1270
1271    // If I-caches are coherent, nothing needs to be done here
1272    if (vai.hwcache_info.icaches_maintain_coherence) return;
1273
1274 #  if defined(VGA_ppc32) || defined(VGA_ppc64be) || defined(VGA_ppc64le)
1275    Addr startaddr = (Addr) ptr;
1276    Addr endaddr   = startaddr + nbytes;
1277    Addr cls;
1278    Addr addr;
1279
1280    cls = vai.ppc_icache_line_szB;
1281
1282    /* Stay sane .. */
1283    vg_assert(cls == 16 || cls == 32 || cls == 64 || cls == 128);
1284
1285    startaddr &= ~(cls - 1);
1286    for (addr = startaddr; addr < endaddr; addr += cls) {
1287       __asm__ __volatile__("dcbst 0,%0" : : "r" (addr));
1288    }
1289    __asm__ __volatile__("sync");
1290    for (addr = startaddr; addr < endaddr; addr += cls) {
1291       __asm__ __volatile__("icbi 0,%0" : : "r" (addr));
1292    }
1293    __asm__ __volatile__("sync; isync");
1294
1295 #  elif defined(VGP_arm_linux)
1296    /* ARM cache flushes are privileged, so we must defer to the kernel. */
1297    Addr startaddr = (Addr) ptr;
1298    Addr endaddr   = startaddr + nbytes;
1299    VG_(do_syscall2)(__NR_ARM_cacheflush, startaddr, endaddr);
1300
1301 #  elif defined(VGP_arm64_linux)
1302    // This arm64_linux section of this function VG_(invalidate_icache)
1303    // is copied from
1304    // https://github.com/armvixl/vixl/blob/master/src/a64/cpu-a64.cc
1305    // which has the following copyright notice:
1306    /*
1307    Copyright 2013, ARM Limited
1308    All rights reserved.
1309
1310    Redistribution and use in source and binary forms, with or without
1311    modification, are permitted provided that the following conditions are met:
1312
1313    * Redistributions of source code must retain the above copyright notice,
1314      this list of conditions and the following disclaimer.
1315    * Redistributions in binary form must reproduce the above copyright notice,
1316      this list of conditions and the following disclaimer in the documentation
1317      and/or other materials provided with the distribution.
1318    * Neither the name of ARM Limited nor the names of its contributors may be
1319      used to endorse or promote products derived from this software without
1320      specific prior written permission.
1321
1322    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND
1323    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
1324    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
1325    DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
1326    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
1327    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
1328    SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
1329    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
1330    OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
1331    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1332    */
1333
1334    // Ask what the I and D line sizes are
1335    UInt cache_type_register;
1336    // Copy the content of the cache type register to a core register.
1337    __asm__ __volatile__ ("mrs %[ctr], ctr_el0" // NOLINT
1338                          : [ctr] "=r" (cache_type_register));
1339
1340    const Int kDCacheLineSizeShift = 16;
1341    const Int kICacheLineSizeShift = 0;
1342    const UInt kDCacheLineSizeMask = 0xf << kDCacheLineSizeShift;
1343    const UInt kICacheLineSizeMask = 0xf << kICacheLineSizeShift;
1344
1345    // The cache type register holds the size of the I and D caches as a power of
1346    // two.
1347    const UInt dcache_line_size_power_of_two =
1348        (cache_type_register & kDCacheLineSizeMask) >> kDCacheLineSizeShift;
1349    const UInt icache_line_size_power_of_two =
1350        (cache_type_register & kICacheLineSizeMask) >> kICacheLineSizeShift;
1351
1352    const UInt dcache_line_size_ = 4 * (1 << dcache_line_size_power_of_two);
1353    const UInt icache_line_size_ = 4 * (1 << icache_line_size_power_of_two);
1354
1355    Addr start = (Addr)ptr;
1356    // Sizes will be used to generate a mask big enough to cover a pointer.
1357    Addr dsize = (Addr)dcache_line_size_;
1358    Addr isize = (Addr)icache_line_size_;
1359
1360    // Cache line sizes are always a power of 2.
1361    Addr dstart = start & ~(dsize - 1);
1362    Addr istart = start & ~(isize - 1);
1363    Addr end    = start + nbytes;
1364
1365    __asm__ __volatile__ (
1366      // Clean every line of the D cache containing the target data.
1367      "0: \n\t"
1368      // dc : Data Cache maintenance
1369      // c : Clean
1370      // va : by (Virtual) Address
1371      // u : to the point of Unification
1372      // The point of unification for a processor is the point by which the
1373      // instruction and data caches are guaranteed to see the same copy of a
1374      // memory location. See ARM DDI 0406B page B2-12 for more information.
1375      "dc cvau, %[dline] \n\t"
1376      "add %[dline], %[dline], %[dsize] \n\t"
1377      "cmp %[dline], %[end] \n\t"
1378      "b.lt 0b \n\t"
1379      // Barrier to make sure the effect of the code above is visible to the rest
1380      // of the world.
1381      // dsb : Data Synchronisation Barrier
1382      // ish : Inner SHareable domain
1383      // The point of unification for an Inner Shareable shareability domain is
1384      // the point by which the instruction and data caches of all the processors
1385      // in that Inner Shareable shareability domain are guaranteed to see the
1386      // same copy of a memory location. See ARM DDI 0406B page B2-12 for more
1387      // information.
1388      "dsb ish \n\t"
1389      // Invalidate every line of the I cache containing the target data.
1390      "1: \n\t"
1391      // ic : instruction cache maintenance
1392      // i : invalidate
1393      // va : by address
1394      // u : to the point of unification
1395      "ic ivau, %[iline] \n\t"
1396      "add %[iline], %[iline], %[isize] \n\t"
1397      "cmp %[iline], %[end] \n\t"
1398      "b.lt 1b \n\t"
1399      // Barrier to make sure the effect of the code above is visible to the rest
1400      // of the world.
1401      "dsb ish \n\t"
1402      // Barrier to ensure any prefetching which happened before this code is
1403      // discarded.
1404      // isb : Instruction Synchronisation Barrier
1405      "isb \n\t"
1406      : [dline] "+r" (dstart),
1407        [iline] "+r" (istart)
1408      : [dsize] "r" (dsize),
1409        [isize] "r" (isize),
1410        [end] "r" (end)
1411      // This code does not write to memory but without the dependency gcc might
1412      // move this code before the code is generated.
1413      : "cc", "memory"
1414    );
1415
1416 #  elif defined(VGA_mips32) || defined(VGA_mips64)
1417    SysRes sres = VG_(do_syscall3)(__NR_cacheflush, (UWord) ptr,
1418                                  (UWord) nbytes, (UWord) 3);
1419    vg_assert( !sr_isError(sres) );
1420
1421 # elif defined(VGA_nanomips)
1422
1423    __builtin___clear_cache(ptr, (char*)ptr + nbytes);
1424
1425 #  endif
1426 }
1427
1428
1429 /* ---------------------------------------------------------------------
1430    dcache flushing
1431    ------------------------------------------------------------------ */
1432
1433 void VG_(flush_dcache) ( void *ptr, SizeT nbytes )
1434 {
1435    /* Currently this is only required on ARM64. */
1436 #  if defined(VGA_arm64)
1437    Addr startaddr = (Addr) ptr;
1438    Addr endaddr   = startaddr + nbytes;
1439    Addr cls;
1440    Addr addr;
1441
1442    ULong ctr_el0;
1443    __asm__ __volatile__ ("mrs %0, ctr_el0" : "=r"(ctr_el0));
1444    cls = 4 * (1ULL << (0xF & (ctr_el0 >> 16)));
1445
1446    /* Stay sane .. */
1447    vg_assert(cls == 64 || cls == 128);
1448
1449    startaddr &= ~(cls - 1);
1450    for (addr = startaddr; addr < endaddr; addr += cls) {
1451       __asm__ __volatile__("dc cvau, %0" : : "r" (addr));
1452    }
1453    __asm__ __volatile__("dsb ish");
1454 #  endif
1455 }
1456
1457 /*--------------------------------------------------------------------*/
1458 /*--- end                                                          ---*/
1459 /*--------------------------------------------------------------------*/