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 <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
  97         if (cpu_tick_frequency == 0)
  98                 return (0);
  99         if (tick > 18446744073709551)           /* floor(2^64 / 1000) */
 100                 return (tick / (cpu_tick_frequency / 1000000));
 101         else if (tick > 18446744073709) /* floor(2^64 / 1000000) */
 102                 return ((tick * 1000) / (cpu_tick_frequency / 1000));
 103         else
 104                 return ((tick * 1000000) / cpu_tick_frequency);
 105 }
 106
 107 /*
 108  * Read proc's from memory file into buffer bp, which has space to hold
 109  * at most maxcnt procs.
 110  */
 111 static int
 112 kvm_proclist(kvm_t *kd, int what, int arg, struct proc *p,
 113     struct kinfo_proc *bp, int maxcnt)
 114 {
 115         int cnt = 0;
 116         struct kinfo_proc kinfo_proc, *kp;
 117         struct pgrp pgrp;
 118         struct session sess;
 119         struct cdev t_cdev;
 120         struct tty tty;
 121         struct vmspace vmspace;
 122         struct sigacts sigacts;
 123 #if 0
 124         struct pstats pstats;
 125 #endif
 126         struct ucred ucred;
 127         struct prison pr;
 128         struct thread mtd;
 129         struct proc proc;
 130         struct proc pproc;
 131         struct sysentvec sysent;
 132         char svname[KI_EMULNAMELEN];
 133
 134         kp = &kinfo_proc;
 135         kp->ki_structsize = sizeof(kinfo_proc);
 136         /*
 137          * Loop on the processes. this is completely broken because we need to be
 138          * able to loop on the threads and merge the ones that are the same process some how.
 139          */
 140         for (; cnt < maxcnt && p != NULL; p = LIST_NEXT(&proc, p_list)) {
 141                 memset(kp, 0, sizeof *kp);
 142                 if (KREAD(kd, (u_long)p, &proc)) {
 143                         _kvm_err(kd, kd->program, "can't read proc at %p", p);
 144                         return (-1);
 145                 }
 146                 if (proc.p_state == PRS_NEW)
 147                         continue;
 148                 if (proc.p_state != PRS_ZOMBIE) {
 149                         if (KREAD(kd, (u_long)TAILQ_FIRST(&proc.p_threads),
 150                             &mtd)) {
 151                                 _kvm_err(kd, kd->program,
 152                                     "can't read thread at %p",
 153                                     TAILQ_FIRST(&proc.p_threads));
 154                                 return (-1);
 155                         }
 156                 }
 157                 if (KREAD(kd, (u_long)proc.p_ucred, &ucred) == 0) {
 158                         kp->ki_ruid = ucred.cr_ruid;
 159                         kp->ki_svuid = ucred.cr_svuid;
 160                         kp->ki_rgid = ucred.cr_rgid;
 161                         kp->ki_svgid = ucred.cr_svgid;
 162                         kp->ki_cr_flags = ucred.cr_flags;
 163                         if (ucred.cr_ngroups > KI_NGROUPS) {
 164                                 kp->ki_ngroups = KI_NGROUPS;
 165                                 kp->ki_cr_flags |= KI_CRF_GRP_OVERFLOW;
 166                         } else
 167                                 kp->ki_ngroups = ucred.cr_ngroups;
 168                         kvm_read(kd, (u_long)ucred.cr_groups, kp->ki_groups,
 169                             kp->ki_ngroups * sizeof(gid_t));
 170                         kp->ki_uid = ucred.cr_uid;
 171                         if (ucred.cr_prison != NULL) {
 172                                 if (KREAD(kd, (u_long)ucred.cr_prison, &pr)) {
 173                                         _kvm_err(kd, kd->program,
 174                                             "can't read prison at %p",
 175                                             ucred.cr_prison);
 176                                         return (-1);
 177                                 }
 178                                 kp->ki_jid = pr.pr_id;
 179                         }
 180                 }
 181
 182                 switch(what & ~KERN_PROC_INC_THREAD) {
 183
 184                 case KERN_PROC_GID:
 185                         if (kp->ki_groups[0] != (gid_t)arg)
 186                                 continue;
 187                         break;
 188
 189                 case KERN_PROC_PID:
 190                         if (proc.p_pid != (pid_t)arg)
 191                                 continue;
 192                         break;
 193
 194                 case KERN_PROC_RGID:
 195                         if (kp->ki_rgid != (gid_t)arg)
 196                                 continue;
 197                         break;
 198
 199                 case KERN_PROC_UID:
 200                         if (kp->ki_uid != (uid_t)arg)
 201                                 continue;
 202                         break;
 203
 204                 case KERN_PROC_RUID:
 205                         if (kp->ki_ruid != (uid_t)arg)
 206                                 continue;
 207                         break;
 208                 }
 209                 /*
 210                  * We're going to add another proc to the set.  If this
 211                  * will overflow the buffer, assume the reason is because
 212                  * nprocs (or the proc list) is corrupt and declare an error.
 213                  */
 214                 if (cnt >= maxcnt) {
 215                         _kvm_err(kd, kd->program, "nprocs corrupt");
 216                         return (-1);
 217                 }
 218                 /*
 219                  * gather kinfo_proc
 220                  */
 221                 kp->ki_paddr = p;
 222                 kp->ki_addr = 0;        /* XXX uarea */
 223                 /* kp->ki_kstack = proc.p_thread.td_kstack; XXXKSE */
 224                 kp->ki_args = proc.p_args;
 225                 kp->ki_tracep = proc.p_tracevp;
 226                 kp->ki_textvp = proc.p_textvp;
 227                 kp->ki_fd = proc.p_fd;
 228                 kp->ki_vmspace = proc.p_vmspace;
 229                 if (proc.p_sigacts != NULL) {
 230                         if (KREAD(kd, (u_long)proc.p_sigacts, &sigacts)) {
 231                                 _kvm_err(kd, kd->program,
 232                                     "can't read sigacts at %p", proc.p_sigacts);
 233                                 return (-1);
 234                         }
 235                         kp->ki_sigignore = sigacts.ps_sigignore;
 236                         kp->ki_sigcatch = sigacts.ps_sigcatch;
 237                 }
 238 #if 0
 239                 if ((proc.p_flag & P_INMEM) && proc.p_stats != NULL) {
 240                         if (KREAD(kd, (u_long)proc.p_stats, &pstats)) {
 241                                 _kvm_err(kd, kd->program,
 242                                     "can't read stats at %x", proc.p_stats);
 243                                 return (-1);
 244                         }
 245                         kp->ki_start = pstats.p_start;
 246
 247                         /*
 248                          * XXX: The times here are probably zero and need
 249                          * to be calculated from the raw data in p_rux and
 250                          * p_crux.
 251                          */
 252                         kp->ki_rusage = pstats.p_ru;
 253                         kp->ki_childstime = pstats.p_cru.ru_stime;
 254                         kp->ki_childutime = pstats.p_cru.ru_utime;
 255                         /* Some callers want child-times in a single value */
 256                         timeradd(&kp->ki_childstime, &kp->ki_childutime,
 257                             &kp->ki_childtime);
 258                 }
 259 #endif
 260                 if (proc.p_oppid)
 261                         kp->ki_ppid = proc.p_oppid;
 262                 else if (proc.p_pptr) {
 263                         if (KREAD(kd, (u_long)proc.p_pptr, &pproc)) {
 264                                 _kvm_err(kd, kd->program,
 265                                     "can't read pproc at %p", proc.p_pptr);
 266                                 return (-1);
 267                         }
 268                         kp->ki_ppid = pproc.p_pid;
 269                 } else
 270                         kp->ki_ppid = 0;
 271                 if (proc.p_pgrp == NULL)
 272                         goto nopgrp;
 273                 if (KREAD(kd, (u_long)proc.p_pgrp, &pgrp)) {
 274                         _kvm_err(kd, kd->program, "can't read pgrp at %p",
 275                                  proc.p_pgrp);
 276                         return (-1);
 277                 }
 278                 kp->ki_pgid = pgrp.pg_id;
 279                 kp->ki_jobc = pgrp.pg_jobc;
 280                 if (KREAD(kd, (u_long)pgrp.pg_session, &sess)) {
 281                         _kvm_err(kd, kd->program, "can't read session at %p",
 282                                 pgrp.pg_session);
 283                         return (-1);
 284                 }
 285                 kp->ki_sid = sess.s_sid;
 286                 (void)memcpy(kp->ki_login, sess.s_login,
 287                                                 sizeof(kp->ki_login));
 288                 kp->ki_kiflag = sess.s_ttyvp ? KI_CTTY : 0;
 289                 if (sess.s_leader == p)
 290                         kp->ki_kiflag |= KI_SLEADER;
 291                 if ((proc.p_flag & P_CONTROLT) && sess.s_ttyp != NULL) {
 292                         if (KREAD(kd, (u_long)sess.s_ttyp, &tty)) {
 293                                 _kvm_err(kd, kd->program,
 294                                          "can't read tty at %p", sess.s_ttyp);
 295                                 return (-1);
 296                         }
 297                         if (tty.t_dev != NULL) {
 298                                 if (KREAD(kd, (u_long)tty.t_dev, &t_cdev)) {
 299                                         _kvm_err(kd, kd->program,
 300                                                  "can't read cdev at %p",
 301                                                 tty.t_dev);
 302                                         return (-1);
 303                                 }
 304 #if 0
 305                                 kp->ki_tdev = t_cdev.si_udev;
 306 #else
 307                                 kp->ki_tdev = NODEV;
 308 #endif
 309                         }
 310                         if (tty.t_pgrp != NULL) {
 311                                 if (KREAD(kd, (u_long)tty.t_pgrp, &pgrp)) {
 312                                         _kvm_err(kd, kd->program,
 313                                                  "can't read tpgrp at %p",
 314                                                 tty.t_pgrp);
 315                                         return (-1);
 316                                 }
 317                                 kp->ki_tpgid = pgrp.pg_id;
 318                         } else
 319                                 kp->ki_tpgid = -1;
 320                         if (tty.t_session != NULL) {
 321                                 if (KREAD(kd, (u_long)tty.t_session, &sess)) {
 322                                         _kvm_err(kd, kd->program,
 323                                             "can't read session at %p",
 324                                             tty.t_session);
 325                                         return (-1);
 326                                 }
 327                                 kp->ki_tsid = sess.s_sid;
 328                         }
 329                 } else {
 330 nopgrp:
 331                         kp->ki_tdev = NODEV;
 332                 }
 333                 if ((proc.p_state != PRS_ZOMBIE) && mtd.td_wmesg)
 334                         (void)kvm_read(kd, (u_long)mtd.td_wmesg,
 335                             kp->ki_wmesg, WMESGLEN);
 336
 337                 (void)kvm_read(kd, (u_long)proc.p_vmspace,
 338                     (char *)&vmspace, sizeof(vmspace));
 339                 kp->ki_size = vmspace.vm_map.size;
 340                 /*
 341                  * Approximate the kernel's method of calculating
 342                  * this field.
 343                  */
 344 #define         pmap_resident_count(pm) ((pm)->pm_stats.resident_count)
 345                 kp->ki_rssize = pmap_resident_count(&vmspace.vm_pmap);
 346                 kp->ki_swrss = vmspace.vm_swrss;
 347                 kp->ki_tsize = vmspace.vm_tsize;
 348                 kp->ki_dsize = vmspace.vm_dsize;
 349                 kp->ki_ssize = vmspace.vm_ssize;
 350
 351                 switch (what & ~KERN_PROC_INC_THREAD) {
 352
 353                 case KERN_PROC_PGRP:
 354                         if (kp->ki_pgid != (pid_t)arg)
 355                                 continue;
 356                         break;
 357
 358                 case KERN_PROC_SESSION:
 359                         if (kp->ki_sid != (pid_t)arg)
 360                                 continue;
 361                         break;
 362
 363                 case KERN_PROC_TTY:
 364                         if ((proc.p_flag & P_CONTROLT) == 0 ||
 365                              kp->ki_tdev != (dev_t)arg)
 366                                 continue;
 367                         break;
 368                 }
 369                 if (proc.p_comm[0] != 0)
 370                         strlcpy(kp->ki_comm, proc.p_comm, MAXCOMLEN);
 371                 (void)kvm_read(kd, (u_long)proc.p_sysent, (char *)&sysent,
 372                     sizeof(sysent));
 373                 (void)kvm_read(kd, (u_long)sysent.sv_name, (char *)&svname,
 374                     sizeof(svname));
 375                 if (svname[0] != 0)
 376                         strlcpy(kp->ki_emul, svname, KI_EMULNAMELEN);
 377                 if ((proc.p_state != PRS_ZOMBIE) &&
 378                     (mtd.td_blocked != 0)) {
 379                         kp->ki_kiflag |= KI_LOCKBLOCK;
 380                         if (mtd.td_lockname)
 381                                 (void)kvm_read(kd,
 382                                     (u_long)mtd.td_lockname,
 383                                     kp->ki_lockname, LOCKNAMELEN);
 384                         kp->ki_lockname[LOCKNAMELEN] = 0;
 385                 }
 386                 kp->ki_runtime = cputick2usec(proc.p_rux.rux_runtime);
 387                 kp->ki_pid = proc.p_pid;
 388                 kp->ki_siglist = proc.p_siglist;
 389                 SIGSETOR(kp->ki_siglist, mtd.td_siglist);
 390                 kp->ki_sigmask = mtd.td_sigmask;
 391                 kp->ki_xstat = KW_EXITCODE(proc.p_xexit, proc.p_xsig);
 392                 kp->ki_acflag = proc.p_acflag;
 393                 kp->ki_lock = proc.p_lock;
 394                 if (proc.p_state != PRS_ZOMBIE) {
 395                         kp->ki_swtime = (ticks - proc.p_swtick) / hz;
 396                         kp->ki_flag = proc.p_flag;
 397                         kp->ki_sflag = 0;
 398                         kp->ki_nice = proc.p_nice;
 399                         kp->ki_traceflag = proc.p_traceflag;
 400                         if (proc.p_state == PRS_NORMAL) {
 401                                 if (TD_ON_RUNQ(&mtd) ||
 402                                     TD_CAN_RUN(&mtd) ||
 403                                     TD_IS_RUNNING(&mtd)) {
 404                                         kp->ki_stat = SRUN;
 405                                 } else if (mtd.td_state ==
 406                                     TDS_INHIBITED) {
 407                                         if (P_SHOULDSTOP(&proc)) {
 408                                                 kp->ki_stat = SSTOP;
 409                                         } else if (
 410                                             TD_IS_SLEEPING(&mtd)) {
 411                                                 kp->ki_stat = SSLEEP;
 412                                         } else if (TD_ON_LOCK(&mtd)) {
 413                                                 kp->ki_stat = SLOCK;
 414                                         } else {
 415                                                 kp->ki_stat = SWAIT;
 416                                         }
 417                                 }
 418                         } else {
 419                                 kp->ki_stat = SIDL;
 420                         }
 421                         /* Stuff from the thread */
 422                         kp->ki_pri.pri_level = mtd.td_priority;
 423                         kp->ki_pri.pri_native = mtd.td_base_pri;
 424                         kp->ki_lastcpu = mtd.td_lastcpu;
 425                         kp->ki_wchan = mtd.td_wchan;
 426                         kp->ki_oncpu = mtd.td_oncpu;
 427                         if (mtd.td_name[0] != '\0')
 428                                 strlcpy(kp->ki_tdname, mtd.td_name, sizeof(kp->ki_tdname));
 429                         kp->ki_pctcpu = 0;
 430                         kp->ki_rqindex = 0;
 431
 432                         /*
 433                          * Note: legacy fields; wraps at NO_CPU_OLD or the
 434                          * old max CPU value as appropriate
 435                          */
 436                         if (mtd.td_lastcpu == NOCPU)
 437                                 kp->ki_lastcpu_old = NOCPU_OLD;
 438                         else if (mtd.td_lastcpu > MAXCPU_OLD)
 439                                 kp->ki_lastcpu_old = MAXCPU_OLD;
 440                         else
 441                                 kp->ki_lastcpu_old = mtd.td_lastcpu;
 442
 443                         if (mtd.td_oncpu == NOCPU)
 444                                 kp->ki_oncpu_old = NOCPU_OLD;
 445                         else if (mtd.td_oncpu > MAXCPU_OLD)
 446                                 kp->ki_oncpu_old = MAXCPU_OLD;
 447                         else
 448                                 kp->ki_oncpu_old = mtd.td_oncpu;
 449                 } else {
 450                         kp->ki_stat = SZOMB;
 451                 }
 452                 kp->ki_tdev_freebsd11 = kp->ki_tdev; /* truncate */
 453                 bcopy(&kinfo_proc, bp, sizeof(kinfo_proc));
 454                 ++bp;
 455                 ++cnt;
 456         }
 457         return (cnt);
 458 }
 459
 460 /*
 461  * Build proc info array by reading in proc list from a crash dump.
 462  * Return number of procs read.  maxcnt is the max we will read.
 463  */
 464 static int
 465 kvm_deadprocs(kvm_t *kd, int what, int arg, u_long a_allproc,
 466     u_long a_zombproc, int maxcnt)
 467 {
 468         struct kinfo_proc *bp = kd->procbase;
 469         int acnt, zcnt;
 470         struct proc *p;
 471
 472         if (KREAD(kd, a_allproc, &p)) {
 473                 _kvm_err(kd, kd->program, "cannot read allproc");
 474                 return (-1);
 475         }
 476         acnt = kvm_proclist(kd, what, arg, p, bp, maxcnt);
 477         if (acnt < 0)
 478                 return (acnt);
 479
 480         if (KREAD(kd, a_zombproc, &p)) {
 481                 _kvm_err(kd, kd->program, "cannot read zombproc");
 482                 return (-1);
 483         }
 484         zcnt = kvm_proclist(kd, what, arg, p, bp + acnt, maxcnt - acnt);
 485         if (zcnt < 0)
 486                 zcnt = 0;
 487
 488         return (acnt + zcnt);
 489 }
 490
 491 struct kinfo_proc *
 492 kvm_getprocs(kvm_t *kd, int op, int arg, int *cnt)
 493 {
 494         int mib[4], st, nprocs;
 495         size_t size, osize;
 496         int temp_op;
 497
 498         if (kd->procbase != 0) {
 499                 free((void *)kd->procbase);
 500                 /*
 501                  * Clear this pointer in case this call fails.  Otherwise,
 502                  * kvm_close() will free it again.
 503                  */
 504                 kd->procbase = 0;
 505         }
 506         if (ISALIVE(kd)) {
 507                 size = 0;
 508                 mib[0] = CTL_KERN;
 509                 mib[1] = KERN_PROC;
 510                 mib[2] = op;
 511                 mib[3] = arg;
 512                 temp_op = op & ~KERN_PROC_INC_THREAD;
 513                 st = sysctl(mib,
 514                     temp_op == KERN_PROC_ALL || temp_op == KERN_PROC_PROC ?
 515                     3 : 4, NULL, &size, NULL, 0);
 516                 if (st == -1) {
 517                         _kvm_syserr(kd, kd->program, "kvm_getprocs");
 518                         return (0);
 519                 }
 520                 /*
 521                  * We can't continue with a size of 0 because we pass
 522                  * it to realloc() (via _kvm_realloc()), and passing 0
 523                  * to realloc() results in undefined behavior.
 524                  */
 525                 if (size == 0) {
 526                         /*
 527                          * XXX: We should probably return an invalid,
 528                          * but non-NULL, pointer here so any client
 529                          * program trying to dereference it will
 530                          * crash.  However, _kvm_freeprocs() calls
 531                          * free() on kd->procbase if it isn't NULL,
 532                          * and free()'ing a junk pointer isn't good.
 533                          * Then again, _kvm_freeprocs() isn't used
 534                          * anywhere . . .
 535                          */
 536                         kd->procbase = _kvm_malloc(kd, 1);
 537                         goto liveout;
 538                 }
 539                 do {
 540                         size += size / 10;
 541                         kd->procbase = (struct kinfo_proc *)
 542                             _kvm_realloc(kd, kd->procbase, size);
 543                         if (kd->procbase == NULL)
 544                                 return (0);
 545                         osize = size;
 546                         st = sysctl(mib, temp_op == KERN_PROC_ALL ||
 547                             temp_op == KERN_PROC_PROC ? 3 : 4,
 548                             kd->procbase, &size, NULL, 0);
 549                 } while (st == -1 && errno == ENOMEM && size == osize);
 550                 if (st == -1) {
 551                         _kvm_syserr(kd, kd->program, "kvm_getprocs");
 552                         return (0);
 553                 }
 554                 /*
 555                  * We have to check the size again because sysctl()
 556                  * may "round up" oldlenp if oldp is NULL; hence it
 557                  * might've told us that there was data to get when
 558                  * there really isn't any.
 559                  */
 560                 if (size > 0 &&
 561                     kd->procbase->ki_structsize != sizeof(struct kinfo_proc)) {
 562                         _kvm_err(kd, kd->program,
 563                             "kinfo_proc size mismatch (expected %zu, got %d)",
 564                             sizeof(struct kinfo_proc),
 565                             kd->procbase->ki_structsize);
 566                         return (0);
 567                 }
 568 liveout:
 569                 nprocs = size == 0 ? 0 : size / kd->procbase->ki_structsize;
 570         } else {
 571                 struct nlist nl[7], *p;
 572
 573                 nl[0].n_name = "_nprocs";
 574                 nl[1].n_name = "_allproc";
 575                 nl[2].n_name = "_zombproc";
 576                 nl[3].n_name = "_ticks";
 577                 nl[4].n_name = "_hz";
 578                 nl[5].n_name = "_cpu_tick_frequency";
 579                 nl[6].n_name = 0;
 580
 581                 if (!kd->arch->ka_native(kd)) {
 582                         _kvm_err(kd, kd->program,
 583                             "cannot read procs from non-native core");
 584                         return (0);
 585                 }
 586
 587                 if (kvm_nlist(kd, nl) != 0) {
 588                         for (p = nl; p->n_type != 0; ++p)
 589                                 ;
 590                         _kvm_err(kd, kd->program,
 591                                  "%s: no such symbol", p->n_name);
 592                         return (0);
 593                 }
 594                 if (KREAD(kd, nl[0].n_value, &nprocs)) {
 595                         _kvm_err(kd, kd->program, "can't read nprocs");
 596                         return (0);
 597                 }
 598                 if (KREAD(kd, nl[3].n_value, &ticks)) {
 599                         _kvm_err(kd, kd->program, "can't read ticks");
 600                         return (0);
 601                 }
 602                 if (KREAD(kd, nl[4].n_value, &hz)) {
 603                         _kvm_err(kd, kd->program, "can't read hz");
 604                         return (0);
 605                 }
 606                 if (KREAD(kd, nl[5].n_value, &cpu_tick_frequency)) {
 607                         _kvm_err(kd, kd->program,
 608                             "can't read cpu_tick_frequency");
 609                         return (0);
 610                 }
 611                 size = nprocs * sizeof(struct kinfo_proc);
 612                 kd->procbase = (struct kinfo_proc *)_kvm_malloc(kd, size);
 613                 if (kd->procbase == NULL)
 614                         return (0);
 615
 616                 nprocs = kvm_deadprocs(kd, op, arg, nl[1].n_value,
 617                                       nl[2].n_value, nprocs);
 618                 if (nprocs <= 0) {
 619                         _kvm_freeprocs(kd);
 620                         nprocs = 0;
 621                 }
 622 #ifdef notdef
 623                 else {
 624                         size = nprocs * sizeof(struct kinfo_proc);
 625                         kd->procbase = realloc(kd->procbase, size);
 626                 }
 627 #endif
 628         }
 629         *cnt = nprocs;
 630         return (kd->procbase);
 631 }
 632
 633 void
 634 _kvm_freeprocs(kvm_t *kd)
 635 {
 636
 637         free(kd->procbase);
 638         kd->procbase = NULL;
 639 }
 640
 641 void *
 642 _kvm_realloc(kvm_t *kd, void *p, size_t n)
 643 {
 644         void *np;
 645
 646         np = reallocf(p, n);
 647         if (np == NULL)
 648                 _kvm_err(kd, kd->program, "out of memory");
 649         return (np);
 650 }
 651
 652 /*
 653  * Get the command args or environment.
 654  */
 655 static char **
 656 kvm_argv(kvm_t *kd, const struct kinfo_proc *kp, int env, int nchr)
 657 {
 658         int oid[4];
 659         int i;
 660         size_t bufsz;
 661         static int buflen;
 662         static char *buf, *p;
 663         static char **bufp;
 664         static int argc;
 665         char **nbufp;
 666
 667         if (!ISALIVE(kd)) {
 668                 _kvm_err(kd, kd->program,
 669                     "cannot read user space from dead kernel");
 670                 return (NULL);
 671         }
 672
 673         if (nchr == 0 || nchr > ARG_MAX)
 674                 nchr = ARG_MAX;
 675         if (buflen == 0) {
 676                 buf = malloc(nchr);
 677                 if (buf == NULL) {
 678                         _kvm_err(kd, kd->program, "cannot allocate memory");
 679                         return (NULL);
 680                 }
 681                 argc = 32;
 682                 bufp = malloc(sizeof(char *) * argc);
 683                 if (bufp == NULL) {
 684                         free(buf);
 685                         buf = NULL;
 686                         _kvm_err(kd, kd->program, "cannot allocate memory");
 687                         return (NULL);
 688                 }
 689                 buflen = nchr;
 690         } else if (nchr > buflen) {
 691                 p = realloc(buf, nchr);
 692                 if (p != NULL) {
 693                         buf = p;
 694                         buflen = nchr;
 695                 }
 696         }
 697         oid[0] = CTL_KERN;
 698         oid[1] = KERN_PROC;
 699         oid[2] = env ? KERN_PROC_ENV : KERN_PROC_ARGS;
 700         oid[3] = kp->ki_pid;
 701         bufsz = buflen;
 702         if (sysctl(oid, 4, buf, &bufsz, 0, 0) == -1) {
 703                 /*
 704                  * If the supplied buf is too short to hold the requested
 705                  * value the sysctl returns with ENOMEM. The buf is filled
 706                  * with the truncated value and the returned bufsz is equal
 707                  * to the requested len.
 708                  */
 709                 if (errno != ENOMEM || bufsz != (size_t)buflen)
 710                         return (NULL);
 711                 buf[bufsz - 1] = '\0';
 712                 errno = 0;
 713         } else if (bufsz == 0)
 714                 return (NULL);
 715         i = 0;
 716         p = buf;
 717         do {
 718                 bufp[i++] = p;
 719                 p += strlen(p) + 1;
 720                 if (i >= argc) {
 721                         argc += argc;
 722                         nbufp = realloc(bufp, sizeof(char *) * argc);
 723                         if (nbufp == NULL)
 724                                 return (NULL);
 725                         bufp = nbufp;
 726                 }
 727         } while (p < buf + bufsz);
 728         bufp[i++] = 0;
 729         return (bufp);
 730 }
 731
 732 char **
 733 kvm_getargv(kvm_t *kd, const struct kinfo_proc *kp, int nchr)
 734 {
 735         return (kvm_argv(kd, kp, 0, nchr));
 736 }
 737
 738 char **
 739 kvm_getenvv(kvm_t *kd, const struct kinfo_proc *kp, int nchr)
 740 {
 741         return (kvm_argv(kd, kp, 1, nchr));
 742 }