lib/libkvm/kvm_proc.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-3-Clause
   3  *
   4  * Copyright (c) 1989, 1992, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software developed by the Computer Systems
   8  * Engineering group at Lawrence Berkeley Laboratory under DARPA contract
   9  * BG 91-66 and contributed to Berkeley.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include <sys/cdefs.h>
  37 __FBSDID("$FreeBSD$");
  38 __SCCSID("@(#)kvm_proc.c        8.3 (Berkeley) 9/23/93");
  39
  40 /*
  41  * Proc traversal interface for kvm.  ps and w are (probably) the exclusive
  42  * users of this code, so we've factored it out into a separate module.
  43  * Thus, we keep this grunge out of the other kvm applications (i.e.,
  44  * most other applications are interested only in open/close/read/nlist).
  45  */
  46
  47 #include <sys/param.h>
  48 #define _WANT_UCRED     /* make ucred.h give us 'struct ucred' */
  49 #include <sys/ucred.h>
  50 #include <sys/queue.h>
  51 #include <sys/_lock.h>
  52 #include <sys/_mutex.h>
  53 #include <sys/_task.h>
  54 #include <sys/cpuset.h>
  55 #include <sys/user.h>
  56 #include <sys/proc.h>
  57 #define _WANT_PRISON    /* make jail.h give us 'struct prison' */
  58 #include <sys/jail.h>
  59 #include <sys/exec.h>
  60 #include <sys/stat.h>
  61 #include <sys/sysent.h>
  62 #include <sys/ioctl.h>
  63 #include <sys/tty.h>
  64 #include <sys/file.h>
  65 #include <sys/conf.h>
  66 #define _WANT_KW_EXITCODE
  67 #include <sys/wait.h>
  68 #include <stdio.h>
  69 #include <stdlib.h>
  70 #include <stdbool.h>
  71 #include <unistd.h>
  72 #include <nlist.h>
  73 #include <kvm.h>
  74
  75 #include <sys/sysctl.h>
  76
  77 #include <limits.h>
  78 #include <memory.h>
  79 #include <paths.h>
  80
  81 #include "kvm_private.h"
  82
  83 #define KREAD(kd, addr, obj) \
  84         (kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj))
  85
  86 static int ticks;
  87 static int hz;
  88 static uint64_t cpu_tick_frequency;
  89
  90 /*
  91  * From sys/kern/kern_tc.c. Depends on cpu_tick_frequency, which is
  92  * read/initialized before this function is ever called.
  93  */
  94 static uint64_t
  95 cputick2usec(uint64_t tick)
  96 {
  97
  98         if (cpu_tick_frequency == 0)
  99                 return (0);
 100         if (tick > 18446744073709551)           /* floor(2^64 / 1000) */
 101                 return (tick / (cpu_tick_frequency / 1000000));
 102         else if (tick > 18446744073709) /* floor(2^64 / 1000000) */
 103                 return ((tick * 1000) / (cpu_tick_frequency / 1000));
 104         else
 105                 return ((tick * 1000000) / cpu_tick_frequency);
 106 }
 107
 108 /*
 109  * Read proc's from memory file into buffer bp, which has space to hold
 110  * at most maxcnt procs.
 111  */
 112 static int
 113 kvm_proclist(kvm_t *kd, int what, int arg, struct proc *p,
 114     struct kinfo_proc *bp, int maxcnt)
 115 {
 116         int cnt = 0;
 117         struct kinfo_proc kinfo_proc, *kp;
 118         struct pgrp pgrp;
 119         struct session sess;
 120         struct cdev t_cdev;
 121         struct tty tty;
 122         struct vmspace vmspace;
 123         struct sigacts sigacts;
 124 #if 0
 125         struct pstats pstats;
 126 #endif
 127         struct ucred ucred;
 128         struct prison pr;
 129         struct thread mtd;
 130         struct proc proc;
 131         struct proc pproc;
 132         struct sysentvec sysent;
 133         char svname[KI_EMULNAMELEN];
 134         struct thread *td = NULL;
 135         bool first_thread;
 136
 137         kp = &kinfo_proc;
 138         kp->ki_structsize = sizeof(kinfo_proc);
 139         /*
 140          * Loop on the processes, then threads within the process if requested.
 141          */
 142         if (what == KERN_PROC_ALL)
 143                 what |= KERN_PROC_INC_THREAD;
 144         for (; cnt < maxcnt && p != NULL; p = LIST_NEXT(&proc, p_list)) {
 145                 memset(kp, 0, sizeof *kp);
 146                 if (KREAD(kd, (u_long)p, &proc)) {
 147                         _kvm_err(kd, kd->program, "can't read proc at %p", p);
 148                         return (-1);
 149                 }
 150                 if (proc.p_state == PRS_NEW)
 151                         continue;
 152                 if (KREAD(kd, (u_long)proc.p_ucred, &ucred) == 0) {
 153                         kp->ki_ruid = ucred.cr_ruid;
 154                         kp->ki_svuid = ucred.cr_svuid;
 155                         kp->ki_rgid = ucred.cr_rgid;
 156                         kp->ki_svgid = ucred.cr_svgid;
 157                         kp->ki_cr_flags = ucred.cr_flags;
 158                         if (ucred.cr_ngroups > KI_NGROUPS) {
 159                                 kp->ki_ngroups = KI_NGROUPS;
 160                                 kp->ki_cr_flags |= KI_CRF_GRP_OVERFLOW;
 161                         } else
 162                                 kp->ki_ngroups = ucred.cr_ngroups;
 163                         kvm_read(kd, (u_long)ucred.cr_groups, kp->ki_groups,
 164                             kp->ki_ngroups * sizeof(gid_t));
 165                         kp->ki_uid = ucred.cr_uid;
 166                         if (ucred.cr_prison != NULL) {
 167                                 if (KREAD(kd, (u_long)ucred.cr_prison, &pr)) {
 168                                         _kvm_err(kd, kd->program,
 169                                             "can't read prison at %p",
 170                                             ucred.cr_prison);
 171                                         return (-1);
 172                                 }
 173                                 kp->ki_jid = pr.pr_id;
 174                         }
 175                 }
 176
 177                 switch(what & ~KERN_PROC_INC_THREAD) {
 178
 179                 case KERN_PROC_GID:
 180                         if (kp->ki_groups[0] != (gid_t)arg)
 181                                 continue;
 182                         break;
 183
 184                 case KERN_PROC_PID:
 185                         if (proc.p_pid != (pid_t)arg)
 186                                 continue;
 187                         break;
 188
 189                 case KERN_PROC_RGID:
 190                         if (kp->ki_rgid != (gid_t)arg)
 191                                 continue;
 192                         break;
 193
 194                 case KERN_PROC_UID:
 195                         if (kp->ki_uid != (uid_t)arg)
 196                                 continue;
 197                         break;
 198
 199                 case KERN_PROC_RUID:
 200                         if (kp->ki_ruid != (uid_t)arg)
 201                                 continue;
 202                         break;
 203                 }
 204                 /*
 205                  * We're going to add another proc to the set.  If this
 206                  * will overflow the buffer, assume the reason is because
 207                  * nprocs (or the proc list) is corrupt and declare an error.
 208                  */
 209                 if (cnt >= maxcnt) {
 210                         _kvm_err(kd, kd->program, "nprocs corrupt");
 211                         return (-1);
 212                 }
 213                 /*
 214                  * gather kinfo_proc
 215                  */
 216                 kp->ki_paddr = p;
 217                 kp->ki_addr = 0;        /* XXX uarea */
 218                 /* kp->ki_kstack = proc.p_thread.td_kstack; XXXKSE */
 219                 kp->ki_args = proc.p_args;
 220                 kp->ki_numthreads = proc.p_numthreads;
 221                 kp->ki_tracep = proc.p_tracevp;
 222                 kp->ki_textvp = proc.p_textvp;
 223                 kp->ki_fd = proc.p_fd;
 224                 kp->ki_vmspace = proc.p_vmspace;
 225                 if (proc.p_sigacts != NULL) {
 226                         if (KREAD(kd, (u_long)proc.p_sigacts, &sigacts)) {
 227                                 _kvm_err(kd, kd->program,
 228                                     "can't read sigacts at %p", proc.p_sigacts);
 229                                 return (-1);
 230                         }
 231                         kp->ki_sigignore = sigacts.ps_sigignore;
 232                         kp->ki_sigcatch = sigacts.ps_sigcatch;
 233                 }
 234 #if 0
 235                 if ((proc.p_flag & P_INMEM) && proc.p_stats != NULL) {
 236                         if (KREAD(kd, (u_long)proc.p_stats, &pstats)) {
 237                                 _kvm_err(kd, kd->program,
 238                                     "can't read stats at %x", proc.p_stats);
 239                                 return (-1);
 240                         }
 241                         kp->ki_start = pstats.p_start;
 242
 243                         /*
 244                          * XXX: The times here are probably zero and need
 245                          * to be calculated from the raw data in p_rux and
 246                          * p_crux.
 247                          */
 248                         kp->ki_rusage = pstats.p_ru;
 249                         kp->ki_childstime = pstats.p_cru.ru_stime;
 250                         kp->ki_childutime = pstats.p_cru.ru_utime;
 251                         /* Some callers want child-times in a single value */
 252                         timeradd(&kp->ki_childstime, &kp->ki_childutime,
 253                             &kp->ki_childtime);
 254                 }
 255 #endif
 256                 if (proc.p_oppid)
 257                         kp->ki_ppid = proc.p_oppid;
 258                 else if (proc.p_pptr) {
 259                         if (KREAD(kd, (u_long)proc.p_pptr, &pproc)) {
 260                                 _kvm_err(kd, kd->program,
 261                                     "can't read pproc at %p", proc.p_pptr);
 262                                 return (-1);
 263                         }
 264                         kp->ki_ppid = pproc.p_pid;
 265                 } else
 266                         kp->ki_ppid = 0;
 267                 if (proc.p_pgrp == NULL)
 268                         goto nopgrp;
 269                 if (KREAD(kd, (u_long)proc.p_pgrp, &pgrp)) {
 270                         _kvm_err(kd, kd->program, "can't read pgrp at %p",
 271                                  proc.p_pgrp);
 272                         return (-1);
 273                 }
 274                 kp->ki_pgid = pgrp.pg_id;
 275                 kp->ki_jobc = pgrp.pg_jobc;
 276                 if (KREAD(kd, (u_long)pgrp.pg_session, &sess)) {
 277                         _kvm_err(kd, kd->program, "can't read session at %p",
 278                                 pgrp.pg_session);
 279                         return (-1);
 280                 }
 281                 kp->ki_sid = sess.s_sid;
 282                 (void)memcpy(kp->ki_login, sess.s_login,
 283                                                 sizeof(kp->ki_login));
 284                 if ((proc.p_flag & P_CONTROLT) && sess.s_ttyp != NULL) {
 285                         if (KREAD(kd, (u_long)sess.s_ttyp, &tty)) {
 286                                 _kvm_err(kd, kd->program,
 287                                          "can't read tty at %p", sess.s_ttyp);
 288                                 return (-1);
 289                         }
 290                         if (tty.t_dev != NULL) {
 291                                 if (KREAD(kd, (u_long)tty.t_dev, &t_cdev)) {
 292                                         _kvm_err(kd, kd->program,
 293                                                  "can't read cdev at %p",
 294                                                 tty.t_dev);
 295                                         return (-1);
 296                                 }
 297 #if 0
 298                                 kp->ki_tdev = t_cdev.si_udev;
 299 #else
 300                                 kp->ki_tdev = NODEV;
 301 #endif
 302                         }
 303                         if (tty.t_pgrp != NULL) {
 304                                 if (KREAD(kd, (u_long)tty.t_pgrp, &pgrp)) {
 305                                         _kvm_err(kd, kd->program,
 306                                                  "can't read tpgrp at %p",
 307                                                 tty.t_pgrp);
 308                                         return (-1);
 309                                 }
 310                                 kp->ki_tpgid = pgrp.pg_id;
 311                         } else
 312                                 kp->ki_tpgid = -1;
 313                         if (tty.t_session != NULL) {
 314                                 if (KREAD(kd, (u_long)tty.t_session, &sess)) {
 315                                         _kvm_err(kd, kd->program,
 316                                             "can't read session at %p",
 317                                             tty.t_session);
 318                                         return (-1);
 319                                 }
 320                                 kp->ki_tsid = sess.s_sid;
 321                         }
 322                 } else {
 323 nopgrp:
 324                         kp->ki_tdev = NODEV;
 325                 }
 326
 327                 (void)kvm_read(kd, (u_long)proc.p_vmspace,
 328                     (char *)&vmspace, sizeof(vmspace));
 329                 kp->ki_size = vmspace.vm_map.size;
 330                 /*
 331                  * Approximate the kernel's method of calculating
 332                  * this field.
 333                  */
 334 #define         pmap_resident_count(pm) ((pm)->pm_stats.resident_count)
 335                 kp->ki_rssize = pmap_resident_count(&vmspace.vm_pmap);
 336                 kp->ki_swrss = vmspace.vm_swrss;
 337                 kp->ki_tsize = vmspace.vm_tsize;
 338                 kp->ki_dsize = vmspace.vm_dsize;
 339                 kp->ki_ssize = vmspace.vm_ssize;
 340
 341                 switch (what & ~KERN_PROC_INC_THREAD) {
 342
 343                 case KERN_PROC_PGRP:
 344                         if (kp->ki_pgid != (pid_t)arg)
 345                                 continue;
 346                         break;
 347
 348                 case KERN_PROC_SESSION:
 349                         if (kp->ki_sid != (pid_t)arg)
 350                                 continue;
 351                         break;
 352
 353                 case KERN_PROC_TTY:
 354                         if ((proc.p_flag & P_CONTROLT) == 0 ||
 355                              kp->ki_tdev != (dev_t)arg)
 356                                 continue;
 357                         break;
 358                 }
 359                 if (proc.p_comm[0] != 0)
 360                         strlcpy(kp->ki_comm, proc.p_comm, MAXCOMLEN);
 361                 (void)kvm_read(kd, (u_long)proc.p_sysent, (char *)&sysent,
 362                     sizeof(sysent));
 363                 (void)kvm_read(kd, (u_long)sysent.sv_name, (char *)&svname,
 364                     sizeof(svname));
 365                 if (svname[0] != 0)
 366                         strlcpy(kp->ki_emul, svname, KI_EMULNAMELEN);
 367                 kp->ki_runtime = cputick2usec(proc.p_rux.rux_runtime);
 368                 kp->ki_pid = proc.p_pid;
 369                 kp->ki_xstat = KW_EXITCODE(proc.p_xexit, proc.p_xsig);
 370                 kp->ki_acflag = proc.p_acflag;
 371                 kp->ki_lock = proc.p_lock;
 372                 kp->ki_tdev_freebsd11 = kp->ki_tdev; /* truncate */
 373
 374                 /* Per-thread items; iterate as appropriate. */
 375                 td = TAILQ_FIRST(&proc.p_threads);
 376                 for (first_thread = true; cnt < maxcnt && td != NULL &&
 377                     (first_thread || (what & KERN_PROC_INC_THREAD));
 378                     first_thread = false) {
 379                         if (proc.p_state != PRS_ZOMBIE) {
 380                                 if (KREAD(kd, (u_long)td, &mtd)) {
 381                                         _kvm_err(kd, kd->program,
 382                                             "can't read thread at %p", td);
 383                                         return (-1);
 384                                 }
 385                                 if (what & KERN_PROC_INC_THREAD)
 386                                         td = TAILQ_NEXT(&mtd, td_plist);
 387                         } else
 388                                 td = NULL;
 389                         if ((proc.p_state != PRS_ZOMBIE) && mtd.td_wmesg)
 390                                 (void)kvm_read(kd, (u_long)mtd.td_wmesg,
 391                                     kp->ki_wmesg, WMESGLEN);
 392                         else
 393                                 memset(kp->ki_wmesg, 0, WMESGLEN);
 394                         if (proc.p_pgrp == NULL) {
 395                                 kp->ki_kiflag = 0;
 396                         } else {
 397                                 kp->ki_kiflag = sess.s_ttyvp ? KI_CTTY : 0;
 398                                 if (sess.s_leader == p)
 399                                         kp->ki_kiflag |= KI_SLEADER;
 400                         }
 401                         if ((proc.p_state != PRS_ZOMBIE) &&
 402                             (mtd.td_blocked != 0)) {
 403                                 kp->ki_kiflag |= KI_LOCKBLOCK;
 404                                 if (mtd.td_lockname)
 405                                         (void)kvm_read(kd,
 406                                             (u_long)mtd.td_lockname,
 407                                             kp->ki_lockname, LOCKNAMELEN);
 408                                 else
 409                                         memset(kp->ki_lockname, 0,
 410                                             LOCKNAMELEN);
 411                                 kp->ki_lockname[LOCKNAMELEN] = 0;
 412                         } else
 413                                 kp->ki_kiflag &= ~KI_LOCKBLOCK;
 414                         kp->ki_siglist = proc.p_siglist;
 415                         if (proc.p_state != PRS_ZOMBIE) {
 416                                 SIGSETOR(kp->ki_siglist, mtd.td_siglist);
 417                                 kp->ki_sigmask = mtd.td_sigmask;
 418                                 kp->ki_swtime = (ticks - proc.p_swtick) / hz;
 419                                 kp->ki_flag = proc.p_flag;
 420                                 kp->ki_sflag = 0;
 421                                 kp->ki_nice = proc.p_nice;
 422                                 kp->ki_traceflag = proc.p_traceflag;
 423                                 if (proc.p_state == PRS_NORMAL) {
 424                                         if (TD_ON_RUNQ(&mtd) ||
 425                                             TD_CAN_RUN(&mtd) ||
 426                                             TD_IS_RUNNING(&mtd)) {
 427                                                 kp->ki_stat = SRUN;
 428                                         } else if (mtd.td_state ==
 429                                             TDS_INHIBITED) {
 430                                                 if (P_SHOULDSTOP(&proc)) {
 431                                                         kp->ki_stat = SSTOP;
 432                                                 } else if (
 433                                                     TD_IS_SLEEPING(&mtd)) {
 434                                                         kp->ki_stat = SSLEEP;
 435                                                 } else if (TD_ON_LOCK(&mtd)) {
 436                                                         kp->ki_stat = SLOCK;
 437                                                 } else {
 438                                                         kp->ki_stat = SWAIT;
 439                                                 }
 440                                         }
 441                                 } else {
 442                                         kp->ki_stat = SIDL;
 443                                 }
 444                                 /* Stuff from the thread */
 445                                 kp->ki_pri.pri_level = mtd.td_priority;
 446                                 kp->ki_pri.pri_native = mtd.td_base_pri;
 447                                 kp->ki_lastcpu = mtd.td_lastcpu;
 448                                 kp->ki_wchan = mtd.td_wchan;
 449                                 kp->ki_oncpu = mtd.td_oncpu;
 450                                 if (mtd.td_name[0] != '\0')
 451                                         strlcpy(kp->ki_tdname, mtd.td_name,
 452                                             sizeof(kp->ki_tdname));
 453                                 else
 454                                         memset(kp->ki_tdname, 0,
 455                                             sizeof(kp->ki_tdname));
 456                                 kp->ki_pctcpu = 0;
 457                                 kp->ki_rqindex = 0;
 458
 459                                 /*
 460                                  * Note: legacy fields; wraps at NO_CPU_OLD
 461                                  * or the old max CPU value as appropriate
 462                                  */
 463                                 if (mtd.td_lastcpu == NOCPU)
 464                                         kp->ki_lastcpu_old = NOCPU_OLD;
 465                                 else if (mtd.td_lastcpu > MAXCPU_OLD)
 466                                         kp->ki_lastcpu_old = MAXCPU_OLD;
 467                                 else
 468                                         kp->ki_lastcpu_old = mtd.td_lastcpu;
 469
 470                                 if (mtd.td_oncpu == NOCPU)
 471                                         kp->ki_oncpu_old = NOCPU_OLD;
 472                                 else if (mtd.td_oncpu > MAXCPU_OLD)
 473                                         kp->ki_oncpu_old = MAXCPU_OLD;
 474                                 else
 475                                         kp->ki_oncpu_old = mtd.td_oncpu;
 476                                 kp->ki_tid = mtd.td_tid;
 477                         } else {
 478                                 memset(&kp->ki_sigmask, 0,
 479                                     sizeof(kp->ki_sigmask));
 480                                 kp->ki_stat = SZOMB;
 481                                 kp->ki_tid = 0;
 482                         }
 483
 484                         bcopy(&kinfo_proc, bp, sizeof(kinfo_proc));
 485                         ++bp;
 486                         ++cnt;
 487                 }
 488         }
 489         return (cnt);
 490 }
 491
 492 /*
 493  * Build proc info array by reading in proc list from a crash dump.
 494  * Return number of procs read.  maxcnt is the max we will read.
 495  */
 496 static int
 497 kvm_deadprocs(kvm_t *kd, int what, int arg, u_long a_allproc,
 498     u_long a_zombproc, int maxcnt)
 499 {
 500         struct kinfo_proc *bp = kd->procbase;
 501         int acnt, zcnt = 0;
 502         struct proc *p;
 503
 504         if (KREAD(kd, a_allproc, &p)) {
 505                 _kvm_err(kd, kd->program, "cannot read allproc");
 506                 return (-1);
 507         }
 508         acnt = kvm_proclist(kd, what, arg, p, bp, maxcnt);
 509         if (acnt < 0)
 510                 return (acnt);
 511
 512         if (a_zombproc != 0) {
 513                 if (KREAD(kd, a_zombproc, &p)) {
 514                         _kvm_err(kd, kd->program, "cannot read zombproc");
 515                         return (-1);
 516                 }
 517                 zcnt = kvm_proclist(kd, what, arg, p, bp + acnt, maxcnt - acnt);
 518                 if (zcnt < 0)
 519                         zcnt = 0;
 520         }
 521
 522         return (acnt + zcnt);
 523 }
 524
 525 struct kinfo_proc *
 526 kvm_getprocs(kvm_t *kd, int op, int arg, int *cnt)
 527 {
 528         int mib[4], st, nprocs;
 529         size_t size, osize;
 530         int temp_op;
 531
 532         if (kd->procbase != 0) {
 533                 free((void *)kd->procbase);
 534                 /*
 535                  * Clear this pointer in case this call fails.  Otherwise,
 536                  * kvm_close() will free it again.
 537                  */
 538                 kd->procbase = 0;
 539         }
 540         if (ISALIVE(kd)) {
 541                 size = 0;
 542                 mib[0] = CTL_KERN;
 543                 mib[1] = KERN_PROC;
 544                 mib[2] = op;
 545                 mib[3] = arg;
 546                 temp_op = op & ~KERN_PROC_INC_THREAD;
 547                 st = sysctl(mib,
 548                     temp_op == KERN_PROC_ALL || temp_op == KERN_PROC_PROC ?
 549                     3 : 4, NULL, &size, NULL, 0);
 550                 if (st == -1) {
 551                         _kvm_syserr(kd, kd->program, "kvm_getprocs");
 552                         return (0);
 553                 }
 554                 /*
 555                  * We can't continue with a size of 0 because we pass
 556                  * it to realloc() (via _kvm_realloc()), and passing 0
 557                  * to realloc() results in undefined behavior.
 558                  */
 559                 if (size == 0) {
 560                         /*
 561                          * XXX: We should probably return an invalid,
 562                          * but non-NULL, pointer here so any client
 563                          * program trying to dereference it will
 564                          * crash.  However, _kvm_freeprocs() calls
 565                          * free() on kd->procbase if it isn't NULL,
 566                          * and free()'ing a junk pointer isn't good.
 567                          * Then again, _kvm_freeprocs() isn't used
 568                          * anywhere . . .
 569                          */
 570                         kd->procbase = _kvm_malloc(kd, 1);
 571                         goto liveout;
 572                 }
 573                 do {
 574                         size += size / 10;
 575                         kd->procbase = (struct kinfo_proc *)
 576                             _kvm_realloc(kd, kd->procbase, size);
 577                         if (kd->procbase == NULL)
 578                                 return (0);
 579                         osize = size;
 580                         st = sysctl(mib, temp_op == KERN_PROC_ALL ||
 581                             temp_op == KERN_PROC_PROC ? 3 : 4,
 582                             kd->procbase, &size, NULL, 0);
 583                 } while (st == -1 && errno == ENOMEM && size == osize);
 584                 if (st == -1) {
 585                         _kvm_syserr(kd, kd->program, "kvm_getprocs");
 586                         return (0);
 587                 }
 588                 /*
 589                  * We have to check the size again because sysctl()
 590                  * may "round up" oldlenp if oldp is NULL; hence it
 591                  * might've told us that there was data to get when
 592                  * there really isn't any.
 593                  */
 594                 if (size > 0 &&
 595                     kd->procbase->ki_structsize != sizeof(struct kinfo_proc)) {
 596                         _kvm_err(kd, kd->program,
 597                             "kinfo_proc size mismatch (expected %zu, got %d)",
 598                             sizeof(struct kinfo_proc),
 599                             kd->procbase->ki_structsize);
 600                         return (0);
 601                 }
 602 liveout:
 603                 nprocs = size == 0 ? 0 : size / kd->procbase->ki_structsize;
 604         } else {
 605                 struct nlist nl[6], *p;
 606                 struct nlist nlz[2];
 607
 608                 nl[0].n_name = "_nprocs";
 609                 nl[1].n_name = "_allproc";
 610                 nl[2].n_name = "_ticks";
 611                 nl[3].n_name = "_hz";
 612                 nl[4].n_name = "_cpu_tick_frequency";
 613                 nl[5].n_name = 0;
 614
 615                 nlz[0].n_name = "_zombproc";
 616                 nlz[1].n_name = 0;
 617
 618                 if (!kd->arch->ka_native(kd)) {
 619                         _kvm_err(kd, kd->program,
 620                             "cannot read procs from non-native core");
 621                         return (0);
 622                 }
 623
 624                 if (kvm_nlist(kd, nl) != 0) {
 625                         for (p = nl; p->n_type != 0; ++p)
 626                                 ;
 627                         _kvm_err(kd, kd->program,
 628                                  "%s: no such symbol", p->n_name);
 629                         return (0);
 630                 }
 631                 (void) kvm_nlist(kd, nlz);      /* attempt to get zombproc */
 632                 if (KREAD(kd, nl[0].n_value, &nprocs)) {
 633                         _kvm_err(kd, kd->program, "can't read nprocs");
 634                         return (0);
 635                 }
 636                 /*
 637                  * If returning all threads, we don't know how many that
 638                  * might be.  Presume that there are, on average, no more
 639                  * than 10 threads per process.
 640                  */
 641                 if (op == KERN_PROC_ALL || (op & KERN_PROC_INC_THREAD))
 642                         nprocs *= 10;           /* XXX */
 643                 if (KREAD(kd, nl[2].n_value, &ticks)) {
 644                         _kvm_err(kd, kd->program, "can't read ticks");
 645                         return (0);
 646                 }
 647                 if (KREAD(kd, nl[3].n_value, &hz)) {
 648                         _kvm_err(kd, kd->program, "can't read hz");
 649                         return (0);
 650                 }
 651                 if (KREAD(kd, nl[4].n_value, &cpu_tick_frequency)) {
 652                         _kvm_err(kd, kd->program,
 653                             "can't read cpu_tick_frequency");
 654                         return (0);
 655                 }
 656                 size = nprocs * sizeof(struct kinfo_proc);
 657                 kd->procbase = (struct kinfo_proc *)_kvm_malloc(kd, size);
 658                 if (kd->procbase == NULL)
 659                         return (0);
 660
 661                 nprocs = kvm_deadprocs(kd, op, arg, nl[1].n_value,
 662                                       nlz[0].n_value, nprocs);
 663                 if (nprocs <= 0) {
 664                         _kvm_freeprocs(kd);
 665                         nprocs = 0;
 666                 }
 667 #ifdef notdef
 668                 else {
 669                         size = nprocs * sizeof(struct kinfo_proc);
 670                         kd->procbase = realloc(kd->procbase, size);
 671                 }
 672 #endif
 673         }
 674         *cnt = nprocs;
 675         return (kd->procbase);
 676 }
 677
 678 void
 679 _kvm_freeprocs(kvm_t *kd)
 680 {
 681
 682         free(kd->procbase);
 683         kd->procbase = NULL;
 684 }
 685
 686 void *
 687 _kvm_realloc(kvm_t *kd, void *p, size_t n)
 688 {
 689         void *np;
 690
 691         np = reallocf(p, n);
 692         if (np == NULL)
 693                 _kvm_err(kd, kd->program, "out of memory");
 694         return (np);
 695 }
 696
 697 /*
 698  * Get the command args or environment.
 699  */
 700 static char **
 701 kvm_argv(kvm_t *kd, const struct kinfo_proc *kp, int env, int nchr)
 702 {
 703         int oid[4];
 704         int i;
 705         size_t bufsz;
 706         static int buflen;
 707         static char *buf, *p;
 708         static char **bufp;
 709         static int argc;
 710         char **nbufp;
 711
 712         if (!ISALIVE(kd)) {
 713                 _kvm_err(kd, kd->program,
 714                     "cannot read user space from dead kernel");
 715                 return (NULL);
 716         }
 717
 718         if (nchr == 0 || nchr > ARG_MAX)
 719                 nchr = ARG_MAX;
 720         if (buflen == 0) {
 721                 buf = malloc(nchr);
 722                 if (buf == NULL) {
 723                         _kvm_err(kd, kd->program, "cannot allocate memory");
 724                         return (NULL);
 725                 }
 726                 argc = 32;
 727                 bufp = malloc(sizeof(char *) * argc);
 728                 if (bufp == NULL) {
 729                         free(buf);
 730                         buf = NULL;
 731                         _kvm_err(kd, kd->program, "cannot allocate memory");
 732                         return (NULL);
 733                 }
 734                 buflen = nchr;
 735         } else if (nchr > buflen) {
 736                 p = realloc(buf, nchr);
 737                 if (p != NULL) {
 738                         buf = p;
 739                         buflen = nchr;
 740                 }
 741         }
 742         oid[0] = CTL_KERN;
 743         oid[1] = KERN_PROC;
 744         oid[2] = env ? KERN_PROC_ENV : KERN_PROC_ARGS;
 745         oid[3] = kp->ki_pid;
 746         bufsz = buflen;
 747         if (sysctl(oid, 4, buf, &bufsz, 0, 0) == -1) {
 748                 /*
 749                  * If the supplied buf is too short to hold the requested
 750                  * value the sysctl returns with ENOMEM. The buf is filled
 751                  * with the truncated value and the returned bufsz is equal
 752                  * to the requested len.
 753                  */
 754                 if (errno != ENOMEM || bufsz != (size_t)buflen)
 755                         return (NULL);
 756                 buf[bufsz - 1] = '\0';
 757                 errno = 0;
 758         } else if (bufsz == 0)
 759                 return (NULL);
 760         i = 0;
 761         p = buf;
 762         do {
 763                 bufp[i++] = p;
 764                 p += strlen(p) + 1;
 765                 if (i >= argc) {
 766                         argc += argc;
 767                         nbufp = realloc(bufp, sizeof(char *) * argc);
 768                         if (nbufp == NULL)
 769                                 return (NULL);
 770                         bufp = nbufp;
 771                 }
 772         } while (p < buf + bufsz);
 773         bufp[i++] = 0;
 774         return (bufp);
 775 }
 776
 777 char **
 778 kvm_getargv(kvm_t *kd, const struct kinfo_proc *kp, int nchr)
 779 {
 780         return (kvm_argv(kd, kp, 0, nchr));
 781 }
 782
 783 char **
 784 kvm_getenvv(kvm_t *kd, const struct kinfo_proc *kp, int nchr)
 785 {
 786         return (kvm_argv(kd, kp, 1, nchr));
 787 }