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