initial import of NetBSD tree

1 files changed, 832 insertions, 0 deletions

diff --git a/lib/libkvm/kvm_proc.c b/lib/libkvm/kvm_proc.c
new file mode 100644
index 00000000000..2e92a482980
--- /dev/null
+++ b/lib/libkvm/kvm_proc.c
@@ -0,0 +1,832 @@
+/*-
+ * Copyright (c) 1994, 1995 Charles M. Hannum.  All rights reserved.
+ * Copyright (c) 1989, 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software developed by the Computer Systems
+ * Engineering group at Lawrence Berkeley Laboratory under DARPA contract
+ * BG 91-66 and contributed to Berkeley.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)kvm_proc.c	8.3 (Berkeley) 9/23/93";
+#endif /* LIBC_SCCS and not lint */
+
+/*
+ * Proc traversal interface for kvm.  ps and w are (probably) the exclusive
+ * users of this code, so we've factored it out into a separate module.
+ * Thus, we keep this grunge out of the other kvm applications (i.e.,
+ * most other applications are interested only in open/close/read/nlist).
+ */
+
+#include <sys/param.h>
+#include <sys/user.h>
+#include <sys/proc.h>
+#include <sys/exec.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/tty.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <nlist.h>
+#include <kvm.h>
+
+#include <vm/vm.h>
+#include <vm/vm_param.h>
+#include <vm/swap_pager.h>
+
+#include <sys/sysctl.h>
+
+#include <limits.h>
+#include <db.h>
+#include <paths.h>
+
+#include "kvm_private.h"
+
+#define KREAD(kd, addr, obj) \
+	(kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj))
+
+int		_kvm_readfromcore __P((kvm_t *, u_long, u_long));
+int		_kvm_readfrompager __P((kvm_t *, struct vm_object *, u_long));
+ssize_t		kvm_uread __P((kvm_t *, const struct proc *, u_long, char *,
+		    size_t));
+
+static char	**kvm_argv __P((kvm_t *, const struct proc *, u_long, int,
+		    int));
+static int	kvm_deadprocs __P((kvm_t *, int, int, u_long, u_long, int));
+static char	**kvm_doargv __P((kvm_t *, const struct kinfo_proc *, int,
+		    void (*)(struct ps_strings *, u_long *, int *)));
+static int	kvm_proclist __P((kvm_t *, int, int, struct proc *,
+		    struct kinfo_proc *, int));
+static int	proc_verify __P((kvm_t *, u_long, const struct proc *));
+static void	ps_str_a __P((struct ps_strings *, u_long *, int *));
+static void	ps_str_e __P((struct ps_strings *, u_long *, int *));
+
+char *
+_kvm_uread(kd, p, va, cnt)
+	kvm_t *kd;
+	const struct proc *p;
+	u_long va;
+	u_long *cnt;
+{
+	register u_long addr, head;
+	register u_long offset;
+	struct vm_map_entry vme;
+	struct vm_object vmo;
+	int rv;
+
+	if (kd->swapspc == 0) {
+		kd->swapspc = (char *)_kvm_malloc(kd, kd->nbpg);
+		if (kd->swapspc == 0)
+			return (0);
+	}
+
+	/*
+	 * Look through the address map for the memory object
+	 * that corresponds to the given virtual address.
+	 * The header just has the entire valid range.
+	 */
+	head = (u_long)&p->p_vmspace->vm_map.header;
+	addr = head;
+	while (1) {
+		if (KREAD(kd, addr, &vme))
+			return (0);
+
+		if (va >= vme.start && va < vme.end && 
+		    vme.object.vm_object != 0)
+			break;
+
+		addr = (u_long)vme.next;
+		if (addr == head)
+			return (0);
+	}
+
+	/*
+	 * We found the right object -- follow shadow links.
+	 */
+	offset = va - vme.start + vme.offset;
+	addr = (u_long)vme.object.vm_object;
+
+	while (1) {
+		/* Try reading the page from core first. */
+		if ((rv = _kvm_readfromcore(kd, addr, offset)))
+			break;
+
+		if (KREAD(kd, addr, &vmo))
+			return (0);
+
+		/* If there is a pager here, see if it has the page. */
+		if (vmo.pager != 0 &&
+		    (rv = _kvm_readfrompager(kd, &vmo, offset)))
+			break;
+
+		/* Move down the shadow chain. */
+		addr = (u_long)vmo.shadow;
+		if (addr == 0)
+			return (0);
+		offset += vmo.shadow_offset;
+	}
+
+	if (rv == -1)
+		return (0);
+
+	/* Found the page. */
+	offset %= kd->nbpg;
+	*cnt = kd->nbpg - offset;
+	return (&kd->swapspc[offset]);
+}
+
+#define	vm_page_hash(kd, object, offset) \
+	(((u_long)object + (u_long)(offset / kd->nbpg)) & kd->vm_page_hash_mask)
+
+int
+_kvm_coreinit(kd)
+	kvm_t *kd;
+{
+	struct nlist nlist[3];
+
+	nlist[0].n_name = "_vm_page_buckets";
+	nlist[1].n_name = "_vm_page_hash_mask";
+	nlist[2].n_name = 0;
+	if (kvm_nlist(kd, nlist) != 0)
+		return (-1);
+
+	if (KREAD(kd, nlist[0].n_value, &kd->vm_page_buckets) ||
+	    KREAD(kd, nlist[1].n_value, &kd->vm_page_hash_mask))
+		return (-1);
+
+	return (0);
+}
+
+int
+_kvm_readfromcore(kd, object, offset)
+	kvm_t *kd;
+	u_long object, offset;
+{
+	u_long addr;
+	struct pglist bucket;
+	struct vm_page mem;
+	off_t seekpoint;
+
+	if (kd->vm_page_buckets == 0 &&
+	    _kvm_coreinit(kd))
+		return (-1);
+
+	addr = (u_long)&kd->vm_page_buckets[vm_page_hash(kd, object, offset)];
+	if (KREAD(kd, addr, &bucket))
+		return (-1);
+
+	addr = (u_long)bucket.tqh_first;
+	offset &= ~(kd->nbpg -1);
+	while (1) {
+		if (addr == 0)
+			return (0);
+
+		if (KREAD(kd, addr, &mem))
+			return (-1);
+
+		if ((u_long)mem.object == object &&
+		    (u_long)mem.offset == offset)
+			break;
+
+		addr = (u_long)mem.hashq.tqe_next;
+	}
+
+	seekpoint = mem.phys_addr;
+
+	if (lseek(kd->pmfd, seekpoint, 0) == -1)
+		return (-1);
+	if (read(kd->pmfd, kd->swapspc, kd->nbpg) != kd->nbpg)
+		return (-1);
+
+	return (1);
+}
+
+int
+_kvm_readfrompager(kd, vmop, offset)
+	kvm_t *kd;
+	struct vm_object *vmop;
+	u_long offset;
+{
+	u_long addr;
+	struct pager_struct pager;
+	struct swpager swap;
+	int ix;
+	struct swblock swb;
+	off_t seekpoint;
+
+	/* Read in the pager info and make sure it's a swap device. */
+	addr = (u_long)vmop->pager;
+	if (KREAD(kd, addr, &pager) || pager.pg_type != PG_SWAP)
+		return (-1);
+
+	/* Read in the swap_pager private data. */
+	addr = (u_long)pager.pg_data;
+	if (KREAD(kd, addr, &swap))
+		return (-1);
+
+	/*
+	 * Calculate the paging offset, and make sure it's within the
+	 * bounds of the pager.
+	 */
+	offset += vmop->paging_offset;
+	ix = offset / dbtob(swap.sw_bsize);
+#if 0
+	if (swap.sw_blocks == 0 || ix >= swap.sw_nblocks)
+		return (-1);
+#else
+	if (swap.sw_blocks == 0 || ix >= swap.sw_nblocks) {
+		int i;
+		printf("BUG BUG BUG BUG:\n");
+		printf("object %x offset %x pgoffset %x pager %x swpager %x\n",
+		    vmop, offset - vmop->paging_offset, vmop->paging_offset,
+		    vmop->pager, pager.pg_data);
+		printf("osize %x bsize %x blocks %x nblocks %x\n",
+		    swap.sw_osize, swap.sw_bsize, swap.sw_blocks,
+		    swap.sw_nblocks);
+		for (ix = 0; ix < swap.sw_nblocks; ix++) {
+			addr = (u_long)&swap.sw_blocks[ix];
+			if (KREAD(kd, addr, &swb))
+				return (0);
+			printf("sw_blocks[%d]: block %x mask %x\n", ix,
+			    swb.swb_block, swb.swb_mask);
+		}
+		return (-1);
+	}
+#endif
+
+	/* Read in the swap records. */
+	addr = (u_long)&swap.sw_blocks[ix];
+	if (KREAD(kd, addr, &swb))
+		return (-1);
+
+	/* Calculate offset within pager. */
+	offset %= dbtob(swap.sw_bsize);
+
+	/* Check that the page is actually present. */
+	if ((swb.swb_mask & (1 << (offset / kd->nbpg))) == 0)
+		return (0);
+
+	if (!ISALIVE(kd))
+		return (-1);
+
+	/* Calculate the physical address and read the page. */
+	seekpoint = dbtob(swb.swb_block) + (offset & ~(kd->nbpg -1));
+
+	if (lseek(kd->swfd, seekpoint, 0) == -1)
+		return (-1);
+	if (read(kd->swfd, kd->swapspc, kd->nbpg) != kd->nbpg)
+		return (-1);
+
+	return (1);
+}
+
+/*
+ * Read proc's from memory file into buffer bp, which has space to hold
+ * at most maxcnt procs.
+ */
+static int
+kvm_proclist(kd, what, arg, p, bp, maxcnt)
+	kvm_t *kd;
+	int what, arg;
+	struct proc *p;
+	struct kinfo_proc *bp;
+	int maxcnt;
+{
+	register int cnt = 0;
+	struct eproc eproc;
+	struct pgrp pgrp;
+	struct session sess;
+	struct tty tty;
+	struct proc proc;
+
+	for (; cnt < maxcnt && p != NULL; p = proc.p_list.le_next) {
+		if (KREAD(kd, (u_long)p, &proc)) {
+			_kvm_err(kd, kd->program, "can't read proc at %x", p);
+			return (-1);
+		}
+		if (KREAD(kd, (u_long)proc.p_cred, &eproc.e_pcred) == 0)
+			KREAD(kd, (u_long)eproc.e_pcred.pc_ucred,
+			      &eproc.e_ucred);
+
+		switch(what) {
+			
+		case KERN_PROC_PID:
+			if (proc.p_pid != (pid_t)arg)
+				continue;
+			break;
+
+		case KERN_PROC_UID:
+			if (eproc.e_ucred.cr_uid != (uid_t)arg)
+				continue;
+			break;
+
+		case KERN_PROC_RUID:
+			if (eproc.e_pcred.p_ruid != (uid_t)arg)
+				continue;
+			break;
+		}
+		/*
+		 * We're going to add another proc to the set.  If this
+		 * will overflow the buffer, assume the reason is because
+		 * nprocs (or the proc list) is corrupt and declare an error.
+		 */
+		if (cnt >= maxcnt) {
+			_kvm_err(kd, kd->program, "nprocs corrupt");
+			return (-1);
+		}
+		/*
+		 * gather eproc
+		 */
+		eproc.e_paddr = p;
+		if (KREAD(kd, (u_long)proc.p_pgrp, &pgrp)) {
+			_kvm_err(kd, kd->program, "can't read pgrp at %x",
+				 proc.p_pgrp);
+			return (-1);
+		}
+		eproc.e_sess = pgrp.pg_session;
+		eproc.e_pgid = pgrp.pg_id;
+		eproc.e_jobc = pgrp.pg_jobc;
+		if (KREAD(kd, (u_long)pgrp.pg_session, &sess)) {
+			_kvm_err(kd, kd->program, "can't read session at %x", 
+				pgrp.pg_session);
+			return (-1);
+		}
+		if ((proc.p_flag & P_CONTROLT) && sess.s_ttyp != NULL) {
+			if (KREAD(kd, (u_long)sess.s_ttyp, &tty)) {
+				_kvm_err(kd, kd->program,
+					 "can't read tty at %x", sess.s_ttyp);
+				return (-1);
+			}
+			eproc.e_tdev = tty.t_dev;
+			eproc.e_tsess = tty.t_session;
+			if (tty.t_pgrp != NULL) {
+				if (KREAD(kd, (u_long)tty.t_pgrp, &pgrp)) {
+					_kvm_err(kd, kd->program,
+						 "can't read tpgrp at &x", 
+						tty.t_pgrp);
+					return (-1);
+				}
+				eproc.e_tpgid = pgrp.pg_id;
+			} else
+				eproc.e_tpgid = -1;
+		} else
+			eproc.e_tdev = NODEV;
+		eproc.e_flag = sess.s_ttyvp ? EPROC_CTTY : 0;
+		if (sess.s_leader == p)
+			eproc.e_flag |= EPROC_SLEADER;
+		if (proc.p_wmesg)
+			(void)kvm_read(kd, (u_long)proc.p_wmesg, 
+			    eproc.e_wmesg, WMESGLEN);
+
+		(void)kvm_read(kd, (u_long)proc.p_vmspace,
+		    (char *)&eproc.e_vm, sizeof(eproc.e_vm));
+
+		eproc.e_xsize = eproc.e_xrssize = 0;
+		eproc.e_xccount = eproc.e_xswrss = 0;
+
+		switch (what) {
+
+		case KERN_PROC_PGRP:
+			if (eproc.e_pgid != (pid_t)arg)
+				continue;
+			break;
+
+		case KERN_PROC_TTY:
+			if ((proc.p_flag & P_CONTROLT) == 0 || 
+			     eproc.e_tdev != (dev_t)arg)
+				continue;
+			break;
+		}
+		bcopy(&proc, &bp->kp_proc, sizeof(proc));
+		bcopy(&eproc, &bp->kp_eproc, sizeof(eproc));
+		++bp;
+		++cnt;
+	}
+	return (cnt);
+}
+
+/*
+ * Build proc info array by reading in proc list from a crash dump.
+ * Return number of procs read.  maxcnt is the max we will read.
+ */
+static int
+kvm_deadprocs(kd, what, arg, a_allproc, a_zombproc, maxcnt)
+	kvm_t *kd;
+	int what, arg;
+	u_long a_allproc;
+	u_long a_zombproc;
+	int maxcnt;
+{
+	register struct kinfo_proc *bp = kd->procbase;
+	register int acnt, zcnt;
+	struct proc *p;
+
+	if (KREAD(kd, a_allproc, &p)) {
+		_kvm_err(kd, kd->program, "cannot read allproc");
+		return (-1);
+	}
+	acnt = kvm_proclist(kd, what, arg, p, bp, maxcnt);
+	if (acnt < 0)
+		return (acnt);
+
+	if (KREAD(kd, a_zombproc, &p)) {
+		_kvm_err(kd, kd->program, "cannot read zombproc");
+		return (-1);
+	}
+	zcnt = kvm_proclist(kd, what, arg, p, bp + acnt, maxcnt - acnt);
+	if (zcnt < 0)
+		zcnt = 0;
+
+	return (acnt + zcnt);
+}
+
+struct kinfo_proc *
+kvm_getprocs(kd, op, arg, cnt)
+	kvm_t *kd;
+	int op, arg;
+	int *cnt;
+{
+	size_t size;
+	int mib[4], st, nprocs;
+
+	if (kd->procbase != 0) {
+		free((void *)kd->procbase);
+		/* 
+		 * Clear this pointer in case this call fails.  Otherwise,
+		 * kvm_close() will free it again.
+		 */
+		kd->procbase = 0;
+	}
+	if (ISALIVE(kd)) {
+		size = 0;
+		mib[0] = CTL_KERN;
+		mib[1] = KERN_PROC;
+		mib[2] = op;
+		mib[3] = arg;
+		st = sysctl(mib, 4, NULL, &size, NULL, 0);
+		if (st == -1) {
+			_kvm_syserr(kd, kd->program, "kvm_getprocs");
+			return (0);
+		}
+		kd->procbase = (struct kinfo_proc *)_kvm_malloc(kd, size);
+		if (kd->procbase == 0)
+			return (0);
+		st = sysctl(mib, 4, kd->procbase, &size, NULL, 0);
+		if (st == -1) {
+			_kvm_syserr(kd, kd->program, "kvm_getprocs");
+			return (0);
+		}
+		if (size % sizeof(struct kinfo_proc) != 0) {
+			_kvm_err(kd, kd->program,
+				"proc size mismatch (%d total, %d chunks)",
+				size, sizeof(struct kinfo_proc));
+			return (0);
+		}
+		nprocs = size / sizeof(struct kinfo_proc);
+	} else {
+		struct nlist nl[4], *p;
+
+		nl[0].n_name = "_nprocs";
+		nl[1].n_name = "_allproc";
+		nl[2].n_name = "_zombproc";
+		nl[3].n_name = 0;
+
+		if (kvm_nlist(kd, nl) != 0) {
+			for (p = nl; p->n_type != 0; ++p)
+				;
+			_kvm_err(kd, kd->program,
+				 "%s: no such symbol", p->n_name);
+			return (0);
+		}
+		if (KREAD(kd, nl[0].n_value, &nprocs)) {
+			_kvm_err(kd, kd->program, "can't read nprocs");
+			return (0);
+		}
+		size = nprocs * sizeof(struct kinfo_proc);
+		kd->procbase = (struct kinfo_proc *)_kvm_malloc(kd, size);
+		if (kd->procbase == 0)
+			return (0);
+
+		nprocs = kvm_deadprocs(kd, op, arg, nl[1].n_value,
+				      nl[2].n_value, nprocs);
+#ifdef notdef
+		size = nprocs * sizeof(struct kinfo_proc);
+		(void)realloc(kd->procbase, size);
+#endif
+	}
+	*cnt = nprocs;
+	return (kd->procbase);
+}
+
+void
+_kvm_freeprocs(kd)
+	kvm_t *kd;
+{
+	if (kd->procbase) {
+		free(kd->procbase);
+		kd->procbase = 0;
+	}
+}
+
+void *
+_kvm_realloc(kd, p, n)
+	kvm_t *kd;
+	void *p;
+	size_t n;
+{
+	void *np = (void *)realloc(p, n);
+
+	if (np == 0)
+		_kvm_err(kd, kd->program, "out of memory");
+	return (np);
+}
+
+#ifndef MAX
+#define MAX(a, b) ((a) > (b) ? (a) : (b))
+#endif
+
+/*
+ * Read in an argument vector from the user address space of process p.
+ * addr if the user-space base address of narg null-terminated contiguous 
+ * strings.  This is used to read in both the command arguments and
+ * environment strings.  Read at most maxcnt characters of strings.
+ */
+static char **
+kvm_argv(kd, p, addr, narg, maxcnt)
+	kvm_t *kd;
+	const struct proc *p;
+	register u_long addr;
+	register int narg;
+	register int maxcnt;
+{
+	register char *np, *cp, *ep, *ap;
+	register u_long oaddr = -1;
+	register int len, cc;
+	register char **argv;
+
+	/*
+	 * Check that there aren't an unreasonable number of agruments,
+	 * and that the address is in user space.
+	 */
+	if (narg > ARG_MAX || addr < VM_MIN_ADDRESS || addr >= VM_MAXUSER_ADDRESS)
+		return (0);
+
+	if (kd->argv == 0) {
+		/*
+		 * Try to avoid reallocs.
+		 */
+		kd->argc = MAX(narg + 1, 32);
+		kd->argv = (char **)_kvm_malloc(kd, kd->argc * 
+						sizeof(*kd->argv));
+		if (kd->argv == 0)
+			return (0);
+	} else if (narg + 1 > kd->argc) {
+		kd->argc = MAX(2 * kd->argc, narg + 1);
+		kd->argv = (char **)_kvm_realloc(kd, kd->argv, kd->argc * 
+						sizeof(*kd->argv));
+		if (kd->argv == 0)
+			return (0);
+	}
+	if (kd->argspc == 0) {
+		kd->argspc = (char *)_kvm_malloc(kd, kd->nbpg);
+		if (kd->argspc == 0)
+			return (0);
+		kd->arglen = kd->nbpg;
+	}
+	if (kd->argbuf == 0) {
+		kd->argbuf = (char *)_kvm_malloc(kd, kd->nbpg);
+		if (kd->argbuf == 0)
+			return (0);
+	}
+	cc = sizeof(char *) * narg;
+	if (kvm_uread(kd, p, addr, (char *)kd->argv, cc) != cc)
+		return (0);
+	ap = np = kd->argspc;
+	argv = kd->argv;
+	len = 0;
+	/*
+	 * Loop over pages, filling in the argument vector.
+	 */
+	while (argv < kd->argv + narg && *argv != 0) {
+		addr = (u_long)*argv & ~(kd->nbpg - 1);
+		if (addr != oaddr) {
+			if (kvm_uread(kd, p, addr, kd->argbuf, kd->nbpg) !=
+			    kd->nbpg)
+				return (0);
+			oaddr = addr;
+		}
+		addr = (u_long)*argv & (kd->nbpg - 1);
+		cp = kd->argbuf + addr;
+		cc = kd->nbpg - addr;
+		if (maxcnt > 0 && cc > maxcnt - len)
+			cc = maxcnt - len;;
+		ep = memchr(cp, '\0', cc);
+		if (ep != 0)
+			cc = ep - cp + 1;
+		if (len + cc > kd->arglen) {
+			register int off;
+			register char **pp;
+			register char *op = kd->argspc;
+
+			kd->arglen *= 2;
+			kd->argspc = (char *)_kvm_realloc(kd, kd->argspc,
+							  kd->arglen);
+			if (kd->argspc == 0)
+				return (0);
+			/*
+			 * Adjust argv pointers in case realloc moved
+			 * the string space.
+			 */
+			off = kd->argspc - op;
+			for (pp = kd->argv; pp < argv; pp++)
+				*pp += off;
+			ap += off;
+			np += off;
+		}
+		memcpy(np, cp, cc);
+		np += cc;
+		len += cc;
+		if (ep != 0) {
+			*argv++ = ap;
+			ap = np;
+		} else
+			*argv += cc;
+		if (maxcnt > 0 && len >= maxcnt) {
+			/*
+			 * We're stopping prematurely.  Terminate the
+			 * current string.
+			 */
+			if (ep == 0) {
+				*np = '\0';
+				*argv++ = ap;
+			}
+			break;
+		}
+	}
+	/* Make sure argv is terminated. */
+	*argv = 0;
+	return (kd->argv);
+}
+
+static void
+ps_str_a(p, addr, n)
+	struct ps_strings *p;
+	u_long *addr;
+	int *n;
+{
+	*addr = (u_long)p->ps_argvstr;
+	*n = p->ps_nargvstr;
+}
+
+static void
+ps_str_e(p, addr, n)
+	struct ps_strings *p;
+	u_long *addr;
+	int *n;
+{
+	*addr = (u_long)p->ps_envstr;
+	*n = p->ps_nenvstr;
+}
+
+/*
+ * Determine if the proc indicated by p is still active.
+ * This test is not 100% foolproof in theory, but chances of
+ * being wrong are very low.
+ */
+static int
+proc_verify(kd, kernp, p)
+	kvm_t *kd;
+	u_long kernp;
+	const struct proc *p;
+{
+	struct proc kernproc;
+
+	/*
+	 * Just read in the whole proc.  It's not that big relative
+	 * to the cost of the read system call.
+	 */
+	if (kvm_read(kd, kernp, (char *)&kernproc, sizeof(kernproc)) != 
+	    sizeof(kernproc))
+		return (0);
+	return (p->p_pid == kernproc.p_pid &&
+		(kernproc.p_stat != SZOMB || p->p_stat == SZOMB));
+}
+
+static char **
+kvm_doargv(kd, kp, nchr, info)
+	kvm_t *kd;
+	const struct kinfo_proc *kp;
+	int nchr;
+	void (*info)(struct ps_strings *, u_long *, int *);
+{
+	register const struct proc *p = &kp->kp_proc;
+	register char **ap;
+	u_long addr;
+	int cnt;
+	struct ps_strings arginfo;
+
+	/*
+	 * Pointers are stored at the top of the user stack.
+	 */
+	if (p->p_stat == SZOMB || 
+	    kvm_uread(kd, p, USRSTACK - sizeof(arginfo), (char *)&arginfo,
+		      sizeof(arginfo)) != sizeof(arginfo))
+		return (0);
+
+	(*info)(&arginfo, &addr, &cnt);
+	if (cnt == 0)
+		return (0);
+	ap = kvm_argv(kd, p, addr, cnt, nchr);
+	/*
+	 * For live kernels, make sure this process didn't go away.
+	 */
+	if (ap != 0 && ISALIVE(kd) &&
+	    !proc_verify(kd, (u_long)kp->kp_eproc.e_paddr, p))
+		ap = 0;
+	return (ap);
+}
+
+/*
+ * Get the command args.  This code is now machine independent.
+ */
+char **
+kvm_getargv(kd, kp, nchr)
+	kvm_t *kd;
+	const struct kinfo_proc *kp;
+	int nchr;
+{
+	return (kvm_doargv(kd, kp, nchr, ps_str_a));
+}
+
+char **
+kvm_getenvv(kd, kp, nchr)
+	kvm_t *kd;
+	const struct kinfo_proc *kp;
+	int nchr;
+{
+	return (kvm_doargv(kd, kp, nchr, ps_str_e));
+}
+
+/*
+ * Read from user space.  The user context is given by p.
+ */
+ssize_t
+kvm_uread(kd, p, uva, buf, len)
+	kvm_t *kd;
+	register const struct proc *p;
+	register u_long uva;
+	register char *buf;
+	register size_t len;
+{
+	register char *cp;
+
+	cp = buf;
+	while (len > 0) {
+		register int cc;
+		register char *dp;
+		u_long cnt;
+
+		dp = _kvm_uread(kd, p, uva, &cnt);
+		if (dp == 0) {
+			_kvm_err(kd, 0, "invalid address (%x)", uva);
+			return (0);
+		}
+		cc = MIN(cnt, len);
+		bcopy(dp, cp, cc);
+
+		cp += cc;
+		uva += cc;
+		len -= cc;
+	}
+	return (ssize_t)(cp - buf);
+}