gdb/netbsd-nat.c

   1 /* Native-dependent code for NetBSD.
   2
   3    Copyright (C) 2006-2023 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21
  22 #include "netbsd-nat.h"
  23 #include "nat/netbsd-nat.h"
  24 #include "gdbthread.h"
  25 #include "netbsd-tdep.h"
  26 #include "inferior.h"
  27 #include "gdbarch.h"
  28 #include "gdbsupport/buildargv.h"
  29
  30 #include <sys/types.h>
  31 #include <sys/ptrace.h>
  32 #include <sys/sysctl.h>
  33 #include <sys/wait.h>
  34
  35 /* Return the name of a file that can be opened to get the symbols for
  36    the child process identified by PID.  */
  37
  38 const char *
  39 nbsd_nat_target::pid_to_exec_file (int pid)
  40 {
  41   return netbsd_nat::pid_to_exec_file (pid);
  42 }
  43
  44 /* Return the current directory for the process identified by PID.  */
  45
  46 static std::string
  47 nbsd_pid_to_cwd (int pid)
  48 {
  49   char buf[PATH_MAX];
  50   size_t buflen;
  51   int mib[4] = {CTL_KERN, KERN_PROC_ARGS, pid, KERN_PROC_CWD};
  52   buflen = sizeof (buf);
  53   if (sysctl (mib, ARRAY_SIZE (mib), buf, &buflen, NULL, 0))
  54     return "";
  55   return buf;
  56 }
  57
  58 /* Return the kinfo_proc2 structure for the process identified by PID.  */
  59
  60 static bool
  61 nbsd_pid_to_kinfo_proc2 (pid_t pid, struct kinfo_proc2 *kp)
  62 {
  63   gdb_assert (kp != nullptr);
  64
  65   size_t size = sizeof (*kp);
  66   int mib[6] = {CTL_KERN, KERN_PROC2, KERN_PROC_PID, pid,
  67                 static_cast<int> (size), 1};
  68   return !sysctl (mib, ARRAY_SIZE (mib), kp, &size, NULL, 0);
  69 }
  70
  71 /* Return the command line for the process identified by PID.  */
  72
  73 static gdb::unique_xmalloc_ptr<char[]>
  74 nbsd_pid_to_cmdline (int pid)
  75 {
  76   int mib[4] = {CTL_KERN, KERN_PROC_ARGS, pid, KERN_PROC_ARGV};
  77
  78   size_t size = 0;
  79   if (::sysctl (mib, ARRAY_SIZE (mib), NULL, &size, NULL, 0) == -1 || size == 0)
  80     return nullptr;
  81
  82   gdb::unique_xmalloc_ptr<char[]> args (XNEWVAR (char, size));
  83
  84   if (::sysctl (mib, ARRAY_SIZE (mib), args.get (), &size, NULL, 0) == -1
  85       || size == 0)
  86     return nullptr;
  87
  88   /* Arguments are returned as a flattened string with NUL separators.
  89      Join the arguments with spaces to form a single string.  */
  90   for (size_t i = 0; i < size - 1; i++)
  91     if (args[i] == '\0')
  92       args[i] = ' ';
  93   args[size - 1] = '\0';
  94
  95   return args;
  96 }
  97
  98 /* Return true if PTID is still active in the inferior.  */
  99
 100 bool
 101 nbsd_nat_target::thread_alive (ptid_t ptid)
 102 {
 103   return netbsd_nat::thread_alive (ptid);
 104 }
 105
 106 /* Return the name assigned to a thread by an application.  Returns
 107    the string in a static buffer.  */
 108
 109 const char *
 110 nbsd_nat_target::thread_name (struct thread_info *thr)
 111 {
 112   ptid_t ptid = thr->ptid;
 113   return netbsd_nat::thread_name (ptid);
 114 }
 115
 116 /* Implement the "post_attach" target_ops method.  */
 117
 118 static void
 119 nbsd_add_threads (nbsd_nat_target *target, pid_t pid)
 120 {
 121   auto fn
 122     = [&target] (ptid_t ptid)
 123       {
 124         if (!in_thread_list (target, ptid))
 125           {
 126             if (inferior_ptid.lwp () == 0)
 127               thread_change_ptid (target, inferior_ptid, ptid);
 128             else
 129               add_thread (target, ptid);
 130           }
 131       };
 132
 133   netbsd_nat::for_each_thread (pid, fn);
 134 }
 135
 136 /* Implement the virtual inf_ptrace_target::post_startup_inferior method.  */
 137
 138 void
 139 nbsd_nat_target::post_startup_inferior (ptid_t ptid)
 140 {
 141   netbsd_nat::enable_proc_events (ptid.pid ());
 142 }
 143
 144 /* Implement the "post_attach" target_ops method.  */
 145
 146 void
 147 nbsd_nat_target::post_attach (int pid)
 148 {
 149   netbsd_nat::enable_proc_events (pid);
 150   nbsd_add_threads (this, pid);
 151 }
 152
 153 /* Implement the "update_thread_list" target_ops method.  */
 154
 155 void
 156 nbsd_nat_target::update_thread_list ()
 157 {
 158   delete_exited_threads ();
 159 }
 160
 161 /* Convert PTID to a string.  */
 162
 163 std::string
 164 nbsd_nat_target::pid_to_str (ptid_t ptid)
 165 {
 166   int lwp = ptid.lwp ();
 167
 168   if (lwp != 0)
 169     {
 170       pid_t pid = ptid.pid ();
 171
 172       return string_printf ("LWP %d of process %d", lwp, pid);
 173     }
 174
 175   return normal_pid_to_str (ptid);
 176 }
 177
 178 /* Retrieve all the memory regions in the specified process.  */
 179
 180 static gdb::unique_xmalloc_ptr<struct kinfo_vmentry[]>
 181 nbsd_kinfo_get_vmmap (pid_t pid, size_t *size)
 182 {
 183   int mib[5] = {CTL_VM, VM_PROC, VM_PROC_MAP, pid,
 184                 sizeof (struct kinfo_vmentry)};
 185
 186   size_t length = 0;
 187   if (sysctl (mib, ARRAY_SIZE (mib), NULL, &length, NULL, 0))
 188     {
 189       *size = 0;
 190       return NULL;
 191     }
 192
 193   /* Prereserve more space.  The length argument is volatile and can change
 194      between the sysctl(3) calls as this function can be called against a
 195      running process.  */
 196   length = length * 5 / 3;
 197
 198   gdb::unique_xmalloc_ptr<struct kinfo_vmentry[]> kiv
 199     (XNEWVAR (kinfo_vmentry, length));
 200
 201   if (sysctl (mib, ARRAY_SIZE (mib), kiv.get (), &length, NULL, 0))
 202     {
 203       *size = 0;
 204       return NULL;
 205     }
 206
 207   *size = length / sizeof (struct kinfo_vmentry);
 208   return kiv;
 209 }
 210
 211 /* Iterate over all the memory regions in the current inferior,
 212    calling FUNC for each memory region.  OBFD is passed as the last
 213    argument to FUNC.  */
 214
 215 int
 216 nbsd_nat_target::find_memory_regions (find_memory_region_ftype func,
 217                                       void *data)
 218 {
 219   pid_t pid = inferior_ptid.pid ();
 220
 221   size_t nitems;
 222   gdb::unique_xmalloc_ptr<struct kinfo_vmentry[]> vmentl
 223     = nbsd_kinfo_get_vmmap (pid, &nitems);
 224   if (vmentl == NULL)
 225     perror_with_name (_("Couldn't fetch VM map entries"));
 226
 227   for (size_t i = 0; i < nitems; i++)
 228     {
 229       struct kinfo_vmentry *kve = &vmentl[i];
 230
 231       /* Skip unreadable segments and those where MAP_NOCORE has been set.  */
 232       if (!(kve->kve_protection & KVME_PROT_READ)
 233           || kve->kve_flags & KVME_FLAG_NOCOREDUMP)
 234         continue;
 235
 236       /* Skip segments with an invalid type.  */
 237       switch (kve->kve_type)
 238         {
 239         case KVME_TYPE_VNODE:
 240         case KVME_TYPE_ANON:
 241         case KVME_TYPE_SUBMAP:
 242         case KVME_TYPE_OBJECT:
 243           break;
 244         default:
 245           continue;
 246         }
 247
 248       size_t size = kve->kve_end - kve->kve_start;
 249       if (info_verbose)
 250         {
 251           gdb_printf ("Save segment, %ld bytes at %s (%c%c%c)\n",
 252                       (long) size,
 253                       paddress (current_inferior ()->arch  (), kve->kve_start),
 254                       kve->kve_protection & KVME_PROT_READ ? 'r' : '-',
 255                       kve->kve_protection & KVME_PROT_WRITE ? 'w' : '-',
 256                       kve->kve_protection & KVME_PROT_EXEC ? 'x' : '-');
 257         }
 258
 259       /* Invoke the callback function to create the corefile segment.
 260          Pass MODIFIED as true, we do not know the real modification state.  */
 261       func (kve->kve_start, size, kve->kve_protection & KVME_PROT_READ,
 262             kve->kve_protection & KVME_PROT_WRITE,
 263             kve->kve_protection & KVME_PROT_EXEC, 1, false, data);
 264     }
 265   return 0;
 266 }
 267
 268 /* Implement the "info_proc" target_ops method.  */
 269
 270 bool
 271 nbsd_nat_target::info_proc (const char *args, enum info_proc_what what)
 272 {
 273   pid_t pid;
 274   bool do_cmdline = false;
 275   bool do_cwd = false;
 276   bool do_exe = false;
 277   bool do_mappings = false;
 278   bool do_status = false;
 279
 280   switch (what)
 281     {
 282     case IP_MINIMAL:
 283       do_cmdline = true;
 284       do_cwd = true;
 285       do_exe = true;
 286       break;
 287     case IP_STAT:
 288     case IP_STATUS:
 289       do_status = true;
 290       break;
 291     case IP_MAPPINGS:
 292       do_mappings = true;
 293       break;
 294     case IP_CMDLINE:
 295       do_cmdline = true;
 296       break;
 297     case IP_EXE:
 298       do_exe = true;
 299       break;
 300     case IP_CWD:
 301       do_cwd = true;
 302       break;
 303     case IP_ALL:
 304       do_cmdline = true;
 305       do_cwd = true;
 306       do_exe = true;
 307       do_mappings = true;
 308       do_status = true;
 309       break;
 310     default:
 311       error (_("Not supported on this target."));
 312     }
 313
 314   gdb_argv built_argv (args);
 315   if (built_argv.count () == 0)
 316     {
 317       pid = inferior_ptid.pid ();
 318       if (pid == 0)
 319         error (_("No current process: you must name one."));
 320     }
 321   else if (built_argv.count () == 1 && isdigit (built_argv[0][0]))
 322     pid = strtol (built_argv[0], NULL, 10);
 323   else
 324     error (_("Invalid arguments."));
 325
 326   gdb_printf (_("process %d\n"), pid);
 327
 328   if (do_cmdline)
 329     {
 330       gdb::unique_xmalloc_ptr<char[]> cmdline = nbsd_pid_to_cmdline (pid);
 331       if (cmdline != nullptr)
 332         gdb_printf ("cmdline = '%s'\n", cmdline.get ());
 333       else
 334         warning (_("unable to fetch command line"));
 335     }
 336   if (do_cwd)
 337     {
 338       std::string cwd = nbsd_pid_to_cwd (pid);
 339       if (cwd != "")
 340         gdb_printf ("cwd = '%s'\n", cwd.c_str ());
 341       else
 342         warning (_("unable to fetch current working directory"));
 343     }
 344   if (do_exe)
 345     {
 346       const char *exe = pid_to_exec_file (pid);
 347       if (exe != nullptr)
 348         gdb_printf ("exe = '%s'\n", exe);
 349       else
 350         warning (_("unable to fetch executable path name"));
 351     }
 352   if (do_mappings)
 353     {
 354       size_t nvment;
 355       gdb::unique_xmalloc_ptr<struct kinfo_vmentry[]> vmentl
 356         = nbsd_kinfo_get_vmmap (pid, &nvment);
 357
 358       if (vmentl != nullptr)
 359         {
 360           int addr_bit = TARGET_CHAR_BIT * sizeof (void *);
 361           nbsd_info_proc_mappings_header (addr_bit);
 362
 363           struct kinfo_vmentry *kve = vmentl.get ();
 364           for (int i = 0; i < nvment; i++, kve++)
 365             nbsd_info_proc_mappings_entry (addr_bit, kve->kve_start,
 366                                            kve->kve_end, kve->kve_offset,
 367                                            kve->kve_flags, kve->kve_protection,
 368                                            kve->kve_path);
 369         }
 370       else
 371         warning (_("unable to fetch virtual memory map"));
 372     }
 373   if (do_status)
 374     {
 375       struct kinfo_proc2 kp;
 376       if (!nbsd_pid_to_kinfo_proc2 (pid, &kp))
 377         warning (_("Failed to fetch process information"));
 378       else
 379         {
 380           auto process_status
 381             = [] (int8_t stat)
 382               {
 383                 switch (stat)
 384                   {
 385                   case SIDL:
 386                     return "IDL";
 387                   case SACTIVE:
 388                     return "ACTIVE";
 389                   case SDYING:
 390                     return "DYING";
 391                   case SSTOP:
 392                     return "STOP";
 393                   case SZOMB:
 394                     return "ZOMB";
 395                   case SDEAD:
 396                     return "DEAD";
 397                   default:
 398                     return "? (unknown)";
 399                   }
 400               };
 401
 402           gdb_printf ("Name: %s\n", kp.p_comm);
 403           gdb_printf ("State: %s\n", process_status(kp.p_realstat));
 404           gdb_printf ("Parent process: %" PRId32 "\n", kp.p_ppid);
 405           gdb_printf ("Process group: %" PRId32 "\n", kp.p__pgid);
 406           gdb_printf ("Session id: %" PRId32 "\n", kp.p_sid);
 407           gdb_printf ("TTY: %" PRId32 "\n", kp.p_tdev);
 408           gdb_printf ("TTY owner process group: %" PRId32 "\n", kp.p_tpgid);
 409           gdb_printf ("User IDs (real, effective, saved): "
 410                       "%" PRIu32 " %" PRIu32 " %" PRIu32 "\n",
 411                       kp.p_ruid, kp.p_uid, kp.p_svuid);
 412           gdb_printf ("Group IDs (real, effective, saved): "
 413                       "%" PRIu32 " %" PRIu32 " %" PRIu32 "\n",
 414                       kp.p_rgid, kp.p_gid, kp.p_svgid);
 415
 416           gdb_printf ("Groups:");
 417           for (int i = 0; i < kp.p_ngroups; i++)
 418             gdb_printf (" %" PRIu32, kp.p_groups[i]);
 419           gdb_printf ("\n");
 420           gdb_printf ("Minor faults (no memory page): %" PRIu64 "\n",
 421                       kp.p_uru_minflt);
 422           gdb_printf ("Major faults (memory page faults): %" PRIu64 "\n",
 423                       kp.p_uru_majflt);
 424           gdb_printf ("utime: %" PRIu32 ".%06" PRIu32 "\n",
 425                       kp.p_uutime_sec, kp.p_uutime_usec);
 426           gdb_printf ("stime: %" PRIu32 ".%06" PRIu32 "\n",
 427                       kp.p_ustime_sec, kp.p_ustime_usec);
 428           gdb_printf ("utime+stime, children: %" PRIu32 ".%06" PRIu32 "\n",
 429                       kp.p_uctime_sec, kp.p_uctime_usec);
 430           gdb_printf ("'nice' value: %" PRIu8 "\n", kp.p_nice);
 431           gdb_printf ("Start time: %" PRIu32 ".%06" PRIu32 "\n",
 432                       kp.p_ustart_sec, kp.p_ustart_usec);
 433           int pgtok = getpagesize () / 1024;
 434           gdb_printf ("Data size: %" PRIuMAX " kB\n",
 435                       (uintmax_t) kp.p_vm_dsize * pgtok);
 436           gdb_printf ("Stack size: %" PRIuMAX " kB\n",
 437                       (uintmax_t) kp.p_vm_ssize * pgtok);
 438           gdb_printf ("Text size: %" PRIuMAX " kB\n",
 439                       (uintmax_t) kp.p_vm_tsize * pgtok);
 440           gdb_printf ("Resident set size: %" PRIuMAX " kB\n",
 441                       (uintmax_t) kp.p_vm_rssize * pgtok);
 442           gdb_printf ("Maximum RSS: %" PRIu64 " kB\n", kp.p_uru_maxrss);
 443           gdb_printf ("Pending Signals:");
 444           for (size_t i = 0; i < ARRAY_SIZE (kp.p_siglist.__bits); i++)
 445             gdb_printf (" %08" PRIx32, kp.p_siglist.__bits[i]);
 446           gdb_printf ("\n");
 447           gdb_printf ("Ignored Signals:");
 448           for (size_t i = 0; i < ARRAY_SIZE (kp.p_sigignore.__bits); i++)
 449             gdb_printf (" %08" PRIx32, kp.p_sigignore.__bits[i]);
 450           gdb_printf ("\n");
 451           gdb_printf ("Caught Signals:");
 452           for (size_t i = 0; i < ARRAY_SIZE (kp.p_sigcatch.__bits); i++)
 453             gdb_printf (" %08" PRIx32, kp.p_sigcatch.__bits[i]);
 454           gdb_printf ("\n");
 455         }
 456     }
 457
 458   return true;
 459 }
 460
 461 /* Resume execution of a specified PTID, that points to a process or a thread
 462    within a process.  If one thread is specified, all other threads are
 463    suspended.  If STEP is nonzero, single-step it.  If SIGNAL is nonzero,
 464    give it that signal.  */
 465
 466 static void
 467 nbsd_resume(nbsd_nat_target *target, ptid_t ptid, int step,
 468             enum gdb_signal signal)
 469 {
 470   int request;
 471
 472   gdb_assert (minus_one_ptid != ptid);
 473
 474   if (ptid.lwp_p ())
 475     {
 476       /* If ptid is a specific LWP, suspend all other LWPs in the process.  */
 477       inferior *inf = find_inferior_ptid (target, ptid);
 478
 479       for (thread_info *tp : inf->non_exited_threads ())
 480         {
 481           if (tp->ptid.lwp () == ptid.lwp ())
 482             request = PT_RESUME;
 483           else
 484             request = PT_SUSPEND;
 485
 486           if (ptrace (request, tp->ptid.pid (), NULL, tp->ptid.lwp ()) == -1)
 487             perror_with_name (("ptrace"));
 488         }
 489     }
 490   else
 491     {
 492       /* If ptid is a wildcard, resume all matching threads (they won't run
 493          until the process is continued however).  */
 494       for (thread_info *tp : all_non_exited_threads (target, ptid))
 495         if (ptrace (PT_RESUME, tp->ptid.pid (), NULL, tp->ptid.lwp ()) == -1)
 496           perror_with_name (("ptrace"));
 497     }
 498
 499   if (step)
 500     {
 501       for (thread_info *tp : all_non_exited_threads (target, ptid))
 502         if (ptrace (PT_SETSTEP, tp->ptid.pid (), NULL, tp->ptid.lwp ()) == -1)
 503           perror_with_name (("ptrace"));
 504     }
 505   else
 506     {
 507       for (thread_info *tp : all_non_exited_threads (target, ptid))
 508         if (ptrace (PT_CLEARSTEP, tp->ptid.pid (), NULL, tp->ptid.lwp ()) == -1)
 509           perror_with_name (("ptrace"));
 510     }
 511
 512   if (catch_syscall_enabled ())
 513     request = PT_SYSCALL;
 514   else
 515     request = PT_CONTINUE;
 516
 517   /* An address of (void *)1 tells ptrace to continue from
 518      where it was.  If GDB wanted it to start some other way, we have
 519      already written a new program counter value to the child.  */
 520   if (ptrace (request, ptid.pid (), (void *)1, gdb_signal_to_host (signal)) == -1)
 521     perror_with_name (("ptrace"));
 522 }
 523
 524 /* Resume execution of thread PTID, or all threads of all inferiors
 525    if PTID is -1.  If STEP is nonzero, single-step it.  If SIGNAL is nonzero,
 526    give it that signal.  */
 527
 528 void
 529 nbsd_nat_target::resume (ptid_t ptid, int step, enum gdb_signal signal)
 530 {
 531   if (minus_one_ptid != ptid)
 532     nbsd_resume (this, ptid, step, signal);
 533   else
 534     {
 535       for (inferior *inf : all_non_exited_inferiors (this))
 536         nbsd_resume (this, ptid_t (inf->pid, 0, 0), step, signal);
 537     }
 538 }
 539
 540 /* Implement a safe wrapper around waitpid().  */
 541
 542 static pid_t
 543 nbsd_wait (ptid_t ptid, struct target_waitstatus *ourstatus,
 544            target_wait_flags options)
 545 {
 546   pid_t pid;
 547   int status;
 548
 549   set_sigint_trap ();
 550
 551   do
 552     {
 553       /* The common code passes WNOHANG that leads to crashes, overwrite it.  */
 554       pid = waitpid (ptid.pid (), &status, 0);
 555     }
 556   while (pid == -1 && errno == EINTR);
 557
 558   clear_sigint_trap ();
 559
 560   if (pid == -1)
 561     perror_with_name (_("Child process unexpectedly missing"));
 562
 563   *ourstatus = host_status_to_waitstatus (status);
 564   return pid;
 565 }
 566
 567 /* Wait for the child specified by PTID to do something.  Return the
 568    process ID of the child, or MINUS_ONE_PTID in case of error; store
 569    the status in *OURSTATUS.  */
 570
 571 ptid_t
 572 nbsd_nat_target::wait (ptid_t ptid, struct target_waitstatus *ourstatus,
 573                        target_wait_flags target_options)
 574 {
 575   pid_t pid = nbsd_wait (ptid, ourstatus, target_options);
 576   ptid_t wptid = ptid_t (pid);
 577
 578   /* If the child stopped, keep investigating its status.  */
 579   if (ourstatus->kind () != TARGET_WAITKIND_STOPPED)
 580     return wptid;
 581
 582   /* Extract the event and thread that received a signal.  */
 583   ptrace_siginfo_t psi;
 584   if (ptrace (PT_GET_SIGINFO, pid, &psi, sizeof (psi)) == -1)
 585     perror_with_name (("ptrace"));
 586
 587   /* Pick child's siginfo_t.  */
 588   siginfo_t *si = &psi.psi_siginfo;
 589
 590   int lwp = psi.psi_lwpid;
 591
 592   int signo = si->si_signo;
 593   const int code = si->si_code;
 594
 595   /* Construct PTID with a specified thread that received the event.
 596      If a signal was targeted to the whole process, lwp is 0.  */
 597   wptid = ptid_t (pid, lwp, 0);
 598
 599   /* Bail out on non-debugger oriented signals..  */
 600   if (signo != SIGTRAP)
 601     return wptid;
 602
 603   /* Stop examining non-debugger oriented SIGTRAP codes.  */
 604   if (code <= SI_USER || code == SI_NOINFO)
 605     return wptid;
 606
 607   /* Process state for threading events */
 608   ptrace_state_t pst = {};
 609   if (code == TRAP_LWP)
 610     {
 611       if (ptrace (PT_GET_PROCESS_STATE, pid, &pst, sizeof (pst)) == -1)
 612         perror_with_name (("ptrace"));
 613     }
 614
 615   if (code == TRAP_LWP && pst.pe_report_event == PTRACE_LWP_EXIT)
 616     {
 617       /* If GDB attaches to a multi-threaded process, exiting
 618          threads might be skipped during post_attach that
 619          have not yet reported their PTRACE_LWP_EXIT event.
 620          Ignore exited events for an unknown LWP.  */
 621       thread_info *thr = this->find_thread (wptid);
 622       if (thr == nullptr)
 623           ourstatus->set_spurious ();
 624       else
 625         {
 626           /* NetBSD does not store an LWP exit status.  */
 627           ourstatus->set_thread_exited (0);
 628
 629           delete_thread (thr);
 630         }
 631
 632       /* The GDB core expects that the rest of the threads are running.  */
 633       if (ptrace (PT_CONTINUE, pid, (void *) 1, 0) == -1)
 634         perror_with_name (("ptrace"));
 635
 636       return wptid;
 637     }
 638
 639   if (in_thread_list (this, ptid_t (pid)))
 640       thread_change_ptid (this, ptid_t (pid), wptid);
 641
 642   if (code == TRAP_LWP && pst.pe_report_event == PTRACE_LWP_CREATE)
 643     {
 644       /* If GDB attaches to a multi-threaded process, newborn
 645          threads might be added by nbsd_add_threads that have
 646          not yet reported their PTRACE_LWP_CREATE event.  Ignore
 647          born events for an already-known LWP.  */
 648       if (in_thread_list (this, wptid))
 649           ourstatus->set_spurious ();
 650       else
 651         {
 652           add_thread (this, wptid);
 653           ourstatus->set_thread_created ();
 654         }
 655       return wptid;
 656     }
 657
 658   if (code == TRAP_EXEC)
 659     {
 660       ourstatus->set_execd (make_unique_xstrdup (pid_to_exec_file (pid)));
 661       return wptid;
 662     }
 663
 664   if (code == TRAP_TRACE)
 665     {
 666       /* Unhandled at this level.  */
 667       return wptid;
 668     }
 669
 670   if (code == TRAP_SCE || code == TRAP_SCX)
 671     {
 672       int sysnum = si->si_sysnum;
 673
 674       if (!catch_syscall_enabled () || !catching_syscall_number (sysnum))
 675         {
 676           /* If the core isn't interested in this event, ignore it.  */
 677           ourstatus->set_spurious ();
 678           return wptid;
 679         }
 680
 681       if (code == TRAP_SCE)
 682         ourstatus->set_syscall_entry (sysnum);
 683       else
 684         ourstatus->set_syscall_return (sysnum);
 685       return wptid;
 686     }
 687
 688   if (code == TRAP_BRKPT)
 689     {
 690       /* Unhandled at this level.  */
 691       return wptid;
 692     }
 693
 694   /* Unclassified SIGTRAP event.  */
 695   ourstatus->set_spurious ();
 696   return wptid;
 697 }
 698
 699 /* Implement the "insert_exec_catchpoint" target_ops method.  */
 700
 701 int
 702 nbsd_nat_target::insert_exec_catchpoint (int pid)
 703 {
 704   /* Nothing to do.  */
 705   return 0;
 706 }
 707
 708 /* Implement the "remove_exec_catchpoint" target_ops method.  */
 709
 710 int
 711 nbsd_nat_target::remove_exec_catchpoint (int pid)
 712 {
 713   /* Nothing to do.  */
 714   return 0;
 715 }
 716
 717 /* Implement the "set_syscall_catchpoint" target_ops method.  */
 718
 719 int
 720 nbsd_nat_target::set_syscall_catchpoint (int pid, bool needed,
 721                                          int any_count,
 722                                          gdb::array_view<const int> syscall_counts)
 723 {
 724   /* Ignore the arguments.  inf-ptrace.c will use PT_SYSCALL which
 725      will catch all system call entries and exits.  The system calls
 726      are filtered by GDB rather than the kernel.  */
 727   return 0;
 728 }
 729
 730 /* Implement the "supports_multi_process" target_ops method. */
 731
 732 bool
 733 nbsd_nat_target::supports_multi_process ()
 734 {
 735   return true;
 736 }
 737
 738 /* Implement the "xfer_partial" target_ops method.  */
 739
 740 enum target_xfer_status
 741 nbsd_nat_target::xfer_partial (enum target_object object,
 742                                const char *annex, gdb_byte *readbuf,
 743                                const gdb_byte *writebuf,
 744                                ULONGEST offset, ULONGEST len,
 745                                ULONGEST *xfered_len)
 746 {
 747   pid_t pid = inferior_ptid.pid ();
 748
 749   switch (object)
 750     {
 751     case TARGET_OBJECT_SIGNAL_INFO:
 752       {
 753         len = netbsd_nat::qxfer_siginfo(pid, annex, readbuf, writebuf, offset,
 754                                         len);
 755
 756         if (len == -1)
 757           return TARGET_XFER_E_IO;
 758
 759         *xfered_len = len;
 760         return TARGET_XFER_OK;
 761       }
 762     case TARGET_OBJECT_MEMORY:
 763       {
 764         size_t xfered;
 765         int res;
 766         if (writebuf != nullptr)
 767           res = netbsd_nat::write_memory (pid, writebuf, offset, len, &xfered);
 768         else
 769           res = netbsd_nat::read_memory (pid, readbuf, offset, len, &xfered);
 770         if (res != 0)
 771           {
 772             if (res == EACCES)
 773               gdb_printf (gdb_stderr, "Cannot %s process at %s (%s). "
 774                           "Is PaX MPROTECT active? See security(7), "
 775                           "sysctl(7), paxctl(8)\n",
 776                           (writebuf ? "write to" : "read from"),
 777                           pulongest (offset), safe_strerror (errno));
 778             return TARGET_XFER_E_IO;
 779           }
 780         if (xfered == 0)
 781           return TARGET_XFER_EOF;
 782         *xfered_len = (ULONGEST) xfered;
 783         return TARGET_XFER_OK;
 784       }
 785     default:
 786       return inf_ptrace_target::xfer_partial (object, annex,
 787                                               readbuf, writebuf, offset,
 788                                               len, xfered_len);
 789     }
 790 }
 791
 792 /* Implement the "supports_dumpcore" target_ops method.  */
 793
 794 bool
 795 nbsd_nat_target::supports_dumpcore ()
 796 {
 797   return true;
 798 }
 799
 800 /* Implement the "dumpcore" target_ops method.  */
 801
 802 void
 803 nbsd_nat_target::dumpcore (const char *filename)
 804 {
 805   pid_t pid = inferior_ptid.pid ();
 806
 807   if (ptrace (PT_DUMPCORE, pid, const_cast<char *>(filename),
 808               strlen (filename)) == -1)
 809     perror_with_name (("ptrace"));
 810 }