lib/libkvm/kvm_proc.c

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