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)
36static 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: stable/11/lib/libkvm/kvm_proc.c 310120 2016-12-15 16:51:33Z vangyzen $");
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#define	_WANT_KW_EXITCODE
70#include <sys/wait.h>
71#include <stdio.h>
72#include <stdlib.h>
73#include <unistd.h>
74#include <nlist.h>
75#include <kvm.h>
76
77#include <sys/sysctl.h>
78
79#include <limits.h>
80#include <memory.h>
81#include <paths.h>
82
83#include "kvm_private.h"
84
85#define KREAD(kd, addr, obj) \
86	(kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj))
87
88static int ticks;
89static int hz;
90static uint64_t cpu_tick_frequency;
91
92/*
93 * From sys/kern/kern_tc.c. Depends on cpu_tick_frequency, which is
94 * read/initialized before this function is ever called.
95 */
96static uint64_t
97cputick2usec(uint64_t tick)
98{
99
100	if (cpu_tick_frequency == 0)
101		return (0);
102	if (tick > 18446744073709551)		/* floor(2^64 / 1000) */
103		return (tick / (cpu_tick_frequency / 1000000));
104	else if (tick > 18446744073709)	/* floor(2^64 / 1000000) */
105		return ((tick * 1000) / (cpu_tick_frequency / 1000));
106	else
107		return ((tick * 1000000) / cpu_tick_frequency);
108}
109
110/*
111 * Read proc's from memory file into buffer bp, which has space to hold
112 * at most maxcnt procs.
113 */
114static int
115kvm_proclist(kvm_t *kd, int what, int arg, struct proc *p,
116    struct kinfo_proc *bp, int maxcnt)
117{
118	int cnt = 0;
119	struct kinfo_proc kinfo_proc, *kp;
120	struct pgrp pgrp;
121	struct session sess;
122	struct cdev t_cdev;
123	struct tty tty;
124	struct vmspace vmspace;
125	struct sigacts sigacts;
126#if 0
127	struct pstats pstats;
128#endif
129	struct ucred ucred;
130	struct prison pr;
131	struct thread mtd;
132	struct proc proc;
133	struct proc pproc;
134	struct sysentvec sysent;
135	char svname[KI_EMULNAMELEN];
136
137	kp = &kinfo_proc;
138	kp->ki_structsize = sizeof(kinfo_proc);
139	/*
140	 * Loop on the processes. this is completely broken because we need to be
141	 * able to loop on the threads and merge the ones that are the same process some how.
142	 */
143	for (; cnt < maxcnt && p != NULL; p = LIST_NEXT(&proc, p_list)) {
144		memset(kp, 0, sizeof *kp);
145		if (KREAD(kd, (u_long)p, &proc)) {
146			_kvm_err(kd, kd->program, "can't read proc at %p", p);
147			return (-1);
148		}
149		if (proc.p_state == PRS_NEW)
150			continue;
151		if (proc.p_state != PRS_ZOMBIE) {
152			if (KREAD(kd, (u_long)TAILQ_FIRST(&proc.p_threads),
153			    &mtd)) {
154				_kvm_err(kd, kd->program,
155				    "can't read thread at %p",
156				    TAILQ_FIRST(&proc.p_threads));
157				return (-1);
158			}
159		}
160		if (KREAD(kd, (u_long)proc.p_ucred, &ucred) == 0) {
161			kp->ki_ruid = ucred.cr_ruid;
162			kp->ki_svuid = ucred.cr_svuid;
163			kp->ki_rgid = ucred.cr_rgid;
164			kp->ki_svgid = ucred.cr_svgid;
165			kp->ki_cr_flags = ucred.cr_flags;
166			if (ucred.cr_ngroups > KI_NGROUPS) {
167				kp->ki_ngroups = KI_NGROUPS;
168				kp->ki_cr_flags |= KI_CRF_GRP_OVERFLOW;
169			} else
170				kp->ki_ngroups = ucred.cr_ngroups;
171			kvm_read(kd, (u_long)ucred.cr_groups, kp->ki_groups,
172			    kp->ki_ngroups * sizeof(gid_t));
173			kp->ki_uid = ucred.cr_uid;
174			if (ucred.cr_prison != NULL) {
175				if (KREAD(kd, (u_long)ucred.cr_prison, &pr)) {
176					_kvm_err(kd, kd->program,
177					    "can't read prison at %p",
178					    ucred.cr_prison);
179					return (-1);
180				}
181				kp->ki_jid = pr.pr_id;
182			}
183		}
184
185		switch(what & ~KERN_PROC_INC_THREAD) {
186
187		case KERN_PROC_GID:
188			if (kp->ki_groups[0] != (gid_t)arg)
189				continue;
190			break;
191
192		case KERN_PROC_PID:
193			if (proc.p_pid != (pid_t)arg)
194				continue;
195			break;
196
197		case KERN_PROC_RGID:
198			if (kp->ki_rgid != (gid_t)arg)
199				continue;
200			break;
201
202		case KERN_PROC_UID:
203			if (kp->ki_uid != (uid_t)arg)
204				continue;
205			break;
206
207		case KERN_PROC_RUID:
208			if (kp->ki_ruid != (uid_t)arg)
209				continue;
210			break;
211		}
212		/*
213		 * We're going to add another proc to the set.  If this
214		 * will overflow the buffer, assume the reason is because
215		 * nprocs (or the proc list) is corrupt and declare an error.
216		 */
217		if (cnt >= maxcnt) {
218			_kvm_err(kd, kd->program, "nprocs corrupt");
219			return (-1);
220		}
221		/*
222		 * gather kinfo_proc
223		 */
224		kp->ki_paddr = p;
225		kp->ki_addr = 0;	/* XXX uarea */
226		/* kp->ki_kstack = proc.p_thread.td_kstack; XXXKSE */
227		kp->ki_args = proc.p_args;
228		kp->ki_tracep = proc.p_tracevp;
229		kp->ki_textvp = proc.p_textvp;
230		kp->ki_fd = proc.p_fd;
231		kp->ki_vmspace = proc.p_vmspace;
232		if (proc.p_sigacts != NULL) {
233			if (KREAD(kd, (u_long)proc.p_sigacts, &sigacts)) {
234				_kvm_err(kd, kd->program,
235				    "can't read sigacts at %p", proc.p_sigacts);
236				return (-1);
237			}
238			kp->ki_sigignore = sigacts.ps_sigignore;
239			kp->ki_sigcatch = sigacts.ps_sigcatch;
240		}
241#if 0
242		if ((proc.p_flag & P_INMEM) && proc.p_stats != NULL) {
243			if (KREAD(kd, (u_long)proc.p_stats, &pstats)) {
244				_kvm_err(kd, kd->program,
245				    "can't read stats at %x", proc.p_stats);
246				return (-1);
247			}
248			kp->ki_start = pstats.p_start;
249
250			/*
251			 * XXX: The times here are probably zero and need
252			 * to be calculated from the raw data in p_rux and
253			 * p_crux.
254			 */
255			kp->ki_rusage = pstats.p_ru;
256			kp->ki_childstime = pstats.p_cru.ru_stime;
257			kp->ki_childutime = pstats.p_cru.ru_utime;
258			/* Some callers want child-times in a single value */
259			timeradd(&kp->ki_childstime, &kp->ki_childutime,
260			    &kp->ki_childtime);
261		}
262#endif
263		if (proc.p_oppid)
264			kp->ki_ppid = proc.p_oppid;
265		else if (proc.p_pptr) {
266			if (KREAD(kd, (u_long)proc.p_pptr, &pproc)) {
267				_kvm_err(kd, kd->program,
268				    "can't read pproc at %p", proc.p_pptr);
269				return (-1);
270			}
271			kp->ki_ppid = pproc.p_pid;
272		} else
273			kp->ki_ppid = 0;
274		if (proc.p_pgrp == NULL)
275			goto nopgrp;
276		if (KREAD(kd, (u_long)proc.p_pgrp, &pgrp)) {
277			_kvm_err(kd, kd->program, "can't read pgrp at %p",
278				 proc.p_pgrp);
279			return (-1);
280		}
281		kp->ki_pgid = pgrp.pg_id;
282		kp->ki_jobc = pgrp.pg_jobc;
283		if (KREAD(kd, (u_long)pgrp.pg_session, &sess)) {
284			_kvm_err(kd, kd->program, "can't read session at %p",
285				pgrp.pg_session);
286			return (-1);
287		}
288		kp->ki_sid = sess.s_sid;
289		(void)memcpy(kp->ki_login, sess.s_login,
290						sizeof(kp->ki_login));
291		kp->ki_kiflag = sess.s_ttyvp ? KI_CTTY : 0;
292		if (sess.s_leader == p)
293			kp->ki_kiflag |= KI_SLEADER;
294		if ((proc.p_flag & P_CONTROLT) && sess.s_ttyp != NULL) {
295			if (KREAD(kd, (u_long)sess.s_ttyp, &tty)) {
296				_kvm_err(kd, kd->program,
297					 "can't read tty at %p", sess.s_ttyp);
298				return (-1);
299			}
300			if (tty.t_dev != NULL) {
301				if (KREAD(kd, (u_long)tty.t_dev, &t_cdev)) {
302					_kvm_err(kd, kd->program,
303						 "can't read cdev at %p",
304						tty.t_dev);
305					return (-1);
306				}
307#if 0
308				kp->ki_tdev = t_cdev.si_udev;
309#else
310				kp->ki_tdev = NODEV;
311#endif
312			}
313			if (tty.t_pgrp != NULL) {
314				if (KREAD(kd, (u_long)tty.t_pgrp, &pgrp)) {
315					_kvm_err(kd, kd->program,
316						 "can't read tpgrp at %p",
317						tty.t_pgrp);
318					return (-1);
319				}
320				kp->ki_tpgid = pgrp.pg_id;
321			} else
322				kp->ki_tpgid = -1;
323			if (tty.t_session != NULL) {
324				if (KREAD(kd, (u_long)tty.t_session, &sess)) {
325					_kvm_err(kd, kd->program,
326					    "can't read session at %p",
327					    tty.t_session);
328					return (-1);
329				}
330				kp->ki_tsid = sess.s_sid;
331			}
332		} else {
333nopgrp:
334			kp->ki_tdev = NODEV;
335		}
336		if ((proc.p_state != PRS_ZOMBIE) && mtd.td_wmesg)
337			(void)kvm_read(kd, (u_long)mtd.td_wmesg,
338			    kp->ki_wmesg, WMESGLEN);
339
340		(void)kvm_read(kd, (u_long)proc.p_vmspace,
341		    (char *)&vmspace, sizeof(vmspace));
342		kp->ki_size = vmspace.vm_map.size;
343		/*
344		 * Approximate the kernel's method of calculating
345		 * this field.
346		 */
347#define		pmap_resident_count(pm) ((pm)->pm_stats.resident_count)
348		kp->ki_rssize = pmap_resident_count(&vmspace.vm_pmap);
349		kp->ki_swrss = vmspace.vm_swrss;
350		kp->ki_tsize = vmspace.vm_tsize;
351		kp->ki_dsize = vmspace.vm_dsize;
352		kp->ki_ssize = vmspace.vm_ssize;
353
354		switch (what & ~KERN_PROC_INC_THREAD) {
355
356		case KERN_PROC_PGRP:
357			if (kp->ki_pgid != (pid_t)arg)
358				continue;
359			break;
360
361		case KERN_PROC_SESSION:
362			if (kp->ki_sid != (pid_t)arg)
363				continue;
364			break;
365
366		case KERN_PROC_TTY:
367			if ((proc.p_flag & P_CONTROLT) == 0 ||
368			     kp->ki_tdev != (dev_t)arg)
369				continue;
370			break;
371		}
372		if (proc.p_comm[0] != 0)
373			strlcpy(kp->ki_comm, proc.p_comm, MAXCOMLEN);
374		(void)kvm_read(kd, (u_long)proc.p_sysent, (char *)&sysent,
375		    sizeof(sysent));
376		(void)kvm_read(kd, (u_long)sysent.sv_name, (char *)&svname,
377		    sizeof(svname));
378		if (svname[0] != 0)
379			strlcpy(kp->ki_emul, svname, KI_EMULNAMELEN);
380		if ((proc.p_state != PRS_ZOMBIE) &&
381		    (mtd.td_blocked != 0)) {
382			kp->ki_kiflag |= KI_LOCKBLOCK;
383			if (mtd.td_lockname)
384				(void)kvm_read(kd,
385				    (u_long)mtd.td_lockname,
386				    kp->ki_lockname, LOCKNAMELEN);
387			kp->ki_lockname[LOCKNAMELEN] = 0;
388		}
389		kp->ki_runtime = cputick2usec(proc.p_rux.rux_runtime);
390		kp->ki_pid = proc.p_pid;
391		kp->ki_siglist = proc.p_siglist;
392		SIGSETOR(kp->ki_siglist, mtd.td_siglist);
393		kp->ki_sigmask = mtd.td_sigmask;
394		kp->ki_xstat = KW_EXITCODE(proc.p_xexit, proc.p_xsig);
395		kp->ki_acflag = proc.p_acflag;
396		kp->ki_lock = proc.p_lock;
397		if (proc.p_state != PRS_ZOMBIE) {
398			kp->ki_swtime = (ticks - proc.p_swtick) / hz;
399			kp->ki_flag = proc.p_flag;
400			kp->ki_sflag = 0;
401			kp->ki_nice = proc.p_nice;
402			kp->ki_traceflag = proc.p_traceflag;
403			if (proc.p_state == PRS_NORMAL) {
404				if (TD_ON_RUNQ(&mtd) ||
405				    TD_CAN_RUN(&mtd) ||
406				    TD_IS_RUNNING(&mtd)) {
407					kp->ki_stat = SRUN;
408				} else if (mtd.td_state ==
409				    TDS_INHIBITED) {
410					if (P_SHOULDSTOP(&proc)) {
411						kp->ki_stat = SSTOP;
412					} else if (
413					    TD_IS_SLEEPING(&mtd)) {
414						kp->ki_stat = SSLEEP;
415					} else if (TD_ON_LOCK(&mtd)) {
416						kp->ki_stat = SLOCK;
417					} else {
418						kp->ki_stat = SWAIT;
419					}
420				}
421			} else {
422				kp->ki_stat = SIDL;
423			}
424			/* Stuff from the thread */
425			kp->ki_pri.pri_level = mtd.td_priority;
426			kp->ki_pri.pri_native = mtd.td_base_pri;
427			kp->ki_lastcpu = mtd.td_lastcpu;
428			kp->ki_wchan = mtd.td_wchan;
429			kp->ki_oncpu = mtd.td_oncpu;
430			if (mtd.td_name[0] != '\0')
431				strlcpy(kp->ki_tdname, mtd.td_name, sizeof(kp->ki_tdname));
432			kp->ki_pctcpu = 0;
433			kp->ki_rqindex = 0;
434
435			/*
436			 * Note: legacy fields; wraps at NO_CPU_OLD or the
437			 * old max CPU value as appropriate
438			 */
439			if (mtd.td_lastcpu == NOCPU)
440				kp->ki_lastcpu_old = NOCPU_OLD;
441			else if (mtd.td_lastcpu > MAXCPU_OLD)
442				kp->ki_lastcpu_old = MAXCPU_OLD;
443			else
444				kp->ki_lastcpu_old = mtd.td_lastcpu;
445
446			if (mtd.td_oncpu == NOCPU)
447				kp->ki_oncpu_old = NOCPU_OLD;
448			else if (mtd.td_oncpu > MAXCPU_OLD)
449				kp->ki_oncpu_old = MAXCPU_OLD;
450			else
451				kp->ki_oncpu_old = mtd.td_oncpu;
452		} else {
453			kp->ki_stat = SZOMB;
454		}
455		bcopy(&kinfo_proc, bp, sizeof(kinfo_proc));
456		++bp;
457		++cnt;
458	}
459	return (cnt);
460}
461
462/*
463 * Build proc info array by reading in proc list from a crash dump.
464 * Return number of procs read.  maxcnt is the max we will read.
465 */
466static int
467kvm_deadprocs(kvm_t *kd, int what, int arg, u_long a_allproc,
468    u_long a_zombproc, int maxcnt)
469{
470	struct kinfo_proc *bp = kd->procbase;
471	int acnt, zcnt;
472	struct proc *p;
473
474	if (KREAD(kd, a_allproc, &p)) {
475		_kvm_err(kd, kd->program, "cannot read allproc");
476		return (-1);
477	}
478	acnt = kvm_proclist(kd, what, arg, p, bp, maxcnt);
479	if (acnt < 0)
480		return (acnt);
481
482	if (KREAD(kd, a_zombproc, &p)) {
483		_kvm_err(kd, kd->program, "cannot read zombproc");
484		return (-1);
485	}
486	zcnt = kvm_proclist(kd, what, arg, p, bp + acnt, maxcnt - acnt);
487	if (zcnt < 0)
488		zcnt = 0;
489
490	return (acnt + zcnt);
491}
492
493struct kinfo_proc *
494kvm_getprocs(kvm_t *kd, int op, int arg, int *cnt)
495{
496	int mib[4], st, nprocs;
497	size_t size, osize;
498	int temp_op;
499
500	if (kd->procbase != 0) {
501		free((void *)kd->procbase);
502		/*
503		 * Clear this pointer in case this call fails.  Otherwise,
504		 * kvm_close() will free it again.
505		 */
506		kd->procbase = 0;
507	}
508	if (ISALIVE(kd)) {
509		size = 0;
510		mib[0] = CTL_KERN;
511		mib[1] = KERN_PROC;
512		mib[2] = op;
513		mib[3] = arg;
514		temp_op = op & ~KERN_PROC_INC_THREAD;
515		st = sysctl(mib,
516		    temp_op == KERN_PROC_ALL || temp_op == KERN_PROC_PROC ?
517		    3 : 4, NULL, &size, NULL, 0);
518		if (st == -1) {
519			_kvm_syserr(kd, kd->program, "kvm_getprocs");
520			return (0);
521		}
522		/*
523		 * We can't continue with a size of 0 because we pass
524		 * it to realloc() (via _kvm_realloc()), and passing 0
525		 * to realloc() results in undefined behavior.
526		 */
527		if (size == 0) {
528			/*
529			 * XXX: We should probably return an invalid,
530			 * but non-NULL, pointer here so any client
531			 * program trying to dereference it will
532			 * crash.  However, _kvm_freeprocs() calls
533			 * free() on kd->procbase if it isn't NULL,
534			 * and free()'ing a junk pointer isn't good.
535			 * Then again, _kvm_freeprocs() isn't used
536			 * anywhere . . .
537			 */
538			kd->procbase = _kvm_malloc(kd, 1);
539			goto liveout;
540		}
541		do {
542			size += size / 10;
543			kd->procbase = (struct kinfo_proc *)
544			    _kvm_realloc(kd, kd->procbase, size);
545			if (kd->procbase == NULL)
546				return (0);
547			osize = size;
548			st = sysctl(mib, temp_op == KERN_PROC_ALL ||
549			    temp_op == KERN_PROC_PROC ? 3 : 4,
550			    kd->procbase, &size, NULL, 0);
551		} while (st == -1 && errno == ENOMEM && size == osize);
552		if (st == -1) {
553			_kvm_syserr(kd, kd->program, "kvm_getprocs");
554			return (0);
555		}
556		/*
557		 * We have to check the size again because sysctl()
558		 * may "round up" oldlenp if oldp is NULL; hence it
559		 * might've told us that there was data to get when
560		 * there really isn't any.
561		 */
562		if (size > 0 &&
563		    kd->procbase->ki_structsize != sizeof(struct kinfo_proc)) {
564			_kvm_err(kd, kd->program,
565			    "kinfo_proc size mismatch (expected %zu, got %d)",
566			    sizeof(struct kinfo_proc),
567			    kd->procbase->ki_structsize);
568			return (0);
569		}
570liveout:
571		nprocs = size == 0 ? 0 : size / kd->procbase->ki_structsize;
572	} else {
573		struct nlist nl[7], *p;
574
575		nl[0].n_name = "_nprocs";
576		nl[1].n_name = "_allproc";
577		nl[2].n_name = "_zombproc";
578		nl[3].n_name = "_ticks";
579		nl[4].n_name = "_hz";
580		nl[5].n_name = "_cpu_tick_frequency";
581		nl[6].n_name = 0;
582
583		if (!kd->arch->ka_native(kd)) {
584			_kvm_err(kd, kd->program,
585			    "cannot read procs from non-native core");
586			return (0);
587		}
588
589		if (kvm_nlist(kd, nl) != 0) {
590			for (p = nl; p->n_type != 0; ++p)
591				;
592			_kvm_err(kd, kd->program,
593				 "%s: no such symbol", p->n_name);
594			return (0);
595		}
596		if (KREAD(kd, nl[0].n_value, &nprocs)) {
597			_kvm_err(kd, kd->program, "can't read nprocs");
598			return (0);
599		}
600		if (KREAD(kd, nl[3].n_value, &ticks)) {
601			_kvm_err(kd, kd->program, "can't read ticks");
602			return (0);
603		}
604		if (KREAD(kd, nl[4].n_value, &hz)) {
605			_kvm_err(kd, kd->program, "can't read hz");
606			return (0);
607		}
608		if (KREAD(kd, nl[5].n_value, &cpu_tick_frequency)) {
609			_kvm_err(kd, kd->program,
610			    "can't read cpu_tick_frequency");
611			return (0);
612		}
613		size = nprocs * sizeof(struct kinfo_proc);
614		kd->procbase = (struct kinfo_proc *)_kvm_malloc(kd, size);
615		if (kd->procbase == NULL)
616			return (0);
617
618		nprocs = kvm_deadprocs(kd, op, arg, nl[1].n_value,
619				      nl[2].n_value, nprocs);
620		if (nprocs <= 0) {
621			_kvm_freeprocs(kd);
622			nprocs = 0;
623		}
624#ifdef notdef
625		else {
626			size = nprocs * sizeof(struct kinfo_proc);
627			kd->procbase = realloc(kd->procbase, size);
628		}
629#endif
630	}
631	*cnt = nprocs;
632	return (kd->procbase);
633}
634
635void
636_kvm_freeprocs(kvm_t *kd)
637{
638
639	free(kd->procbase);
640	kd->procbase = NULL;
641}
642
643void *
644_kvm_realloc(kvm_t *kd, void *p, size_t n)
645{
646	void *np;
647
648	np = reallocf(p, n);
649	if (np == NULL)
650		_kvm_err(kd, kd->program, "out of memory");
651	return (np);
652}
653
654/*
655 * Get the command args or environment.
656 */
657static char **
658kvm_argv(kvm_t *kd, const struct kinfo_proc *kp, int env, int nchr)
659{
660	int oid[4];
661	int i;
662	size_t bufsz;
663	static int buflen;
664	static char *buf, *p;
665	static char **bufp;
666	static int argc;
667	char **nbufp;
668
669	if (!ISALIVE(kd)) {
670		_kvm_err(kd, kd->program,
671		    "cannot read user space from dead kernel");
672		return (NULL);
673	}
674
675	if (nchr == 0 || nchr > ARG_MAX)
676		nchr = ARG_MAX;
677	if (buflen == 0) {
678		buf = malloc(nchr);
679		if (buf == NULL) {
680			_kvm_err(kd, kd->program, "cannot allocate memory");
681			return (NULL);
682		}
683		argc = 32;
684		bufp = malloc(sizeof(char *) * argc);
685		if (bufp == NULL) {
686			free(buf);
687			buf = NULL;
688			_kvm_err(kd, kd->program, "cannot allocate memory");
689			return (NULL);
690		}
691		buflen = nchr;
692	} else if (nchr > buflen) {
693		p = realloc(buf, nchr);
694		if (p != NULL) {
695			buf = p;
696			buflen = nchr;
697		}
698	}
699	oid[0] = CTL_KERN;
700	oid[1] = KERN_PROC;
701	oid[2] = env ? KERN_PROC_ENV : KERN_PROC_ARGS;
702	oid[3] = kp->ki_pid;
703	bufsz = buflen;
704	if (sysctl(oid, 4, buf, &bufsz, 0, 0) == -1) {
705		/*
706		 * If the supplied buf is too short to hold the requested
707		 * value the sysctl returns with ENOMEM. The buf is filled
708		 * with the truncated value and the returned bufsz is equal
709		 * to the requested len.
710		 */
711		if (errno != ENOMEM || bufsz != (size_t)buflen)
712			return (NULL);
713		buf[bufsz - 1] = '\0';
714		errno = 0;
715	} else if (bufsz == 0)
716		return (NULL);
717	i = 0;
718	p = buf;
719	do {
720		bufp[i++] = p;
721		p += strlen(p) + 1;
722		if (i >= argc) {
723			argc += argc;
724			nbufp = realloc(bufp, sizeof(char *) * argc);
725			if (nbufp == NULL)
726				return (NULL);
727			bufp = nbufp;
728		}
729	} while (p < buf + bufsz);
730	bufp[i++] = 0;
731	return (bufp);
732}
733
734char **
735kvm_getargv(kvm_t *kd, const struct kinfo_proc *kp, int nchr)
736{
737	return (kvm_argv(kd, kp, 0, nchr));
738}
739
740char **
741kvm_getenvv(kvm_t *kd, const struct kinfo_proc *kp, int nchr)
742{
743	return (kvm_argv(kd, kp, 1, nchr));
744}
745