xref: /openbsd-src/lib/libkvm/kvm_proc.c (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1 /*	$OpenBSD: kvm_proc.c,v 1.8 2001/06/27 06:16:45 art Exp $	*/
2 /*	$NetBSD: kvm_proc.c,v 1.30 1999/03/24 05:50:50 mrg Exp $	*/
3 /*-
4  * Copyright (c) 1998 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Charles M. Hannum.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 /*-
39  * Copyright (c) 1994, 1995 Charles M. Hannum.  All rights reserved.
40  * Copyright (c) 1989, 1992, 1993
41  *	The Regents of the University of California.  All rights reserved.
42  *
43  * This code is derived from software developed by the Computer Systems
44  * Engineering group at Lawrence Berkeley Laboratory under DARPA contract
45  * BG 91-66 and contributed to Berkeley.
46  *
47  * Redistribution and use in source and binary forms, with or without
48  * modification, are permitted provided that the following conditions
49  * are met:
50  * 1. Redistributions of source code must retain the above copyright
51  *    notice, this list of conditions and the following disclaimer.
52  * 2. Redistributions in binary form must reproduce the above copyright
53  *    notice, this list of conditions and the following disclaimer in the
54  *    documentation and/or other materials provided with the distribution.
55  * 3. All advertising materials mentioning features or use of this software
56  *    must display the following acknowledgement:
57  *	This product includes software developed by the University of
58  *	California, Berkeley and its contributors.
59  * 4. Neither the name of the University nor the names of its contributors
60  *    may be used to endorse or promote products derived from this software
61  *    without specific prior written permission.
62  *
63  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
64  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
65  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
66  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
67  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
68  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
69  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
70  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
71  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
72  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
73  * SUCH DAMAGE.
74  */
75 
76 #if defined(LIBC_SCCS) && !defined(lint)
77 #if 0
78 static char sccsid[] = "@(#)kvm_proc.c	8.3 (Berkeley) 9/23/93";
79 #else
80 static char *rcsid = "$OpenBSD: kvm_proc.c,v 1.8 2001/06/27 06:16:45 art Exp $";
81 #endif
82 #endif /* LIBC_SCCS and not lint */
83 
84 /*
85  * Proc traversal interface for kvm.  ps and w are (probably) the exclusive
86  * users of this code, so we've factored it out into a separate module.
87  * Thus, we keep this grunge out of the other kvm applications (i.e.,
88  * most other applications are interested only in open/close/read/nlist).
89  */
90 
91 #include <sys/param.h>
92 #include <sys/user.h>
93 #include <sys/proc.h>
94 #include <sys/exec.h>
95 #include <sys/stat.h>
96 #include <sys/ioctl.h>
97 #include <sys/tty.h>
98 #include <stdlib.h>
99 #include <string.h>
100 #include <unistd.h>
101 #include <nlist.h>
102 #include <kvm.h>
103 
104 #include <vm/vm.h>
105 #include <vm/vm_param.h>
106 
107 #include <uvm/uvm_extern.h>
108 #include <uvm/uvm_amap.h>
109 
110 #include <sys/sysctl.h>
111 
112 #include <limits.h>
113 #include <db.h>
114 #include <paths.h>
115 
116 #include "kvm_private.h"
117 
118 #define KREAD(kd, addr, obj) \
119 	(kvm_read(kd, addr, (void *)(obj), sizeof(*obj)) != sizeof(*obj))
120 
121 ssize_t		kvm_uread __P((kvm_t *, const struct proc *, u_long, char *,
122 		    size_t));
123 
124 static char	**kvm_argv __P((kvm_t *, const struct proc *, u_long, int,
125 		    int));
126 static int	kvm_deadprocs __P((kvm_t *, int, int, u_long, u_long, int));
127 static char	**kvm_doargv __P((kvm_t *, const struct kinfo_proc *, int,
128 		    void (*)(struct ps_strings *, u_long *, int *)));
129 static int	kvm_proclist __P((kvm_t *, int, int, struct proc *,
130 		    struct kinfo_proc *, int));
131 static int	proc_verify __P((kvm_t *, u_long, const struct proc *));
132 static void	ps_str_a __P((struct ps_strings *, u_long *, int *));
133 static void	ps_str_e __P((struct ps_strings *, u_long *, int *));
134 
135 char *
136 _kvm_uread(kd, p, va, cnt)
137 	kvm_t *kd;
138 	const struct proc *p;
139 	u_long va;
140 	u_long *cnt;
141 {
142 	u_long addr, head;
143 	u_long offset;
144 	struct vm_map_entry vme;
145 	struct vm_amap amap;
146 	struct vm_anon *anonp, anon;
147 	struct vm_page pg;
148 	u_long slot;
149 
150 	if (kd->swapspc == 0) {
151 		kd->swapspc = (char *)_kvm_malloc(kd, kd->nbpg);
152 		if (kd->swapspc == 0)
153 			return (0);
154 	}
155 
156 	/*
157 	 * Look through the address map for the memory object
158 	 * that corresponds to the given virtual address.
159 	 * The header just has the entire valid range.
160 	 */
161 	head = (u_long)&p->p_vmspace->vm_map.header;
162 	addr = head;
163 	while (1) {
164 		if (KREAD(kd, addr, &vme))
165 			return (0);
166 
167 		if (va >= vme.start && va < vme.end &&
168 		    vme.aref.ar_amap != NULL)
169 			break;
170 
171 		addr = (u_long)vme.next;
172 		if (addr == head)
173 			return (0);
174 	}
175 
176 	/*
177 	 * we found the map entry, now to find the object...
178 	 */
179 	if (vme.aref.ar_amap == NULL)
180 		return NULL;
181 
182 	addr = (u_long)vme.aref.ar_amap;
183 	if (KREAD(kd, addr, &amap))
184 		return NULL;
185 
186 	offset = va - vme.start;
187 	slot = offset / kd->nbpg + vme.aref.ar_pageoff;
188 	/* sanity-check slot number */
189 	if (slot > amap.am_nslot)
190 		return NULL;
191 
192 	addr = (u_long)amap.am_anon + (offset / kd->nbpg) * sizeof(anonp);
193 	if (KREAD(kd, addr, &anonp))
194 		return NULL;
195 
196 	addr = (u_long)anonp;
197 	if (KREAD(kd, addr, &anon))
198 		return NULL;
199 
200 	addr = (u_long)anon.u.an_page;
201 	if (addr) {
202 		if (KREAD(kd, addr, &pg))
203 			return NULL;
204 
205 		if (_kvm_pread(kd, kd->pmfd, (void *)kd->swapspc, (size_t)kd->nbpg, (off_t)pg.phys_addr) != kd->nbpg) {
206 			return NULL;
207 		}
208 	} else {
209 		if (_kvm_pread(kd, kd->swfd, (void *)kd->swapspc, (size_t)kd->nbpg, (off_t)(anon.an_swslot * kd->nbpg)) != kd->nbpg) {
210 			return NULL;
211 		}
212 	}
213 
214 	/* Found the page. */
215 	offset %= kd->nbpg;
216 	*cnt = kd->nbpg - offset;
217 	return (&kd->swapspc[offset]);
218 }
219 
220 /*
221  * Read proc's from memory file into buffer bp, which has space to hold
222  * at most maxcnt procs.
223  */
224 static int
225 kvm_proclist(kd, what, arg, p, bp, maxcnt)
226 	kvm_t *kd;
227 	int what, arg;
228 	struct proc *p;
229 	struct kinfo_proc *bp;
230 	int maxcnt;
231 {
232 	int cnt = 0;
233 	struct eproc eproc;
234 	struct pgrp pgrp;
235 	struct session sess;
236 	struct tty tty;
237 	struct proc proc;
238 
239 	for (; cnt < maxcnt && p != NULL; p = proc.p_list.le_next) {
240 		if (KREAD(kd, (u_long)p, &proc)) {
241 			_kvm_err(kd, kd->program, "can't read proc at %x", p);
242 			return (-1);
243 		}
244 		if (KREAD(kd, (u_long)proc.p_cred, &eproc.e_pcred) == 0)
245 			KREAD(kd, (u_long)eproc.e_pcred.pc_ucred,
246 			      &eproc.e_ucred);
247 
248 		switch(what) {
249 
250 		case KERN_PROC_PID:
251 			if (proc.p_pid != (pid_t)arg)
252 				continue;
253 			break;
254 
255 		case KERN_PROC_UID:
256 			if (eproc.e_ucred.cr_uid != (uid_t)arg)
257 				continue;
258 			break;
259 
260 		case KERN_PROC_RUID:
261 			if (eproc.e_pcred.p_ruid != (uid_t)arg)
262 				continue;
263 			break;
264 
265 		case KERN_PROC_ALL:
266 			if (proc.p_flag & P_SYSTEM)
267 				continue;
268 			break;
269 		}
270 		/*
271 		 * We're going to add another proc to the set.  If this
272 		 * will overflow the buffer, assume the reason is because
273 		 * nprocs (or the proc list) is corrupt and declare an error.
274 		 */
275 		if (cnt >= maxcnt) {
276 			_kvm_err(kd, kd->program, "nprocs corrupt");
277 			return (-1);
278 		}
279 		/*
280 		 * gather eproc
281 		 */
282 		eproc.e_paddr = p;
283 		if (KREAD(kd, (u_long)proc.p_pgrp, &pgrp)) {
284 			_kvm_err(kd, kd->program, "can't read pgrp at %x",
285 				 proc.p_pgrp);
286 			return (-1);
287 		}
288 		eproc.e_sess = pgrp.pg_session;
289 		eproc.e_pgid = pgrp.pg_id;
290 		eproc.e_jobc = pgrp.pg_jobc;
291 		if (KREAD(kd, (u_long)pgrp.pg_session, &sess)) {
292 			_kvm_err(kd, kd->program, "can't read session at %x",
293 				pgrp.pg_session);
294 			return (-1);
295 		}
296 		if ((proc.p_flag & P_CONTROLT) && sess.s_ttyp != NULL) {
297 			if (KREAD(kd, (u_long)sess.s_ttyp, &tty)) {
298 				_kvm_err(kd, kd->program,
299 					 "can't read tty at %x", sess.s_ttyp);
300 				return (-1);
301 			}
302 			eproc.e_tdev = tty.t_dev;
303 			eproc.e_tsess = tty.t_session;
304 			if (tty.t_pgrp != NULL) {
305 				if (KREAD(kd, (u_long)tty.t_pgrp, &pgrp)) {
306 					_kvm_err(kd, kd->program,
307 						 "can't read tpgrp at &x",
308 						tty.t_pgrp);
309 					return (-1);
310 				}
311 				eproc.e_tpgid = pgrp.pg_id;
312 			} else
313 				eproc.e_tpgid = -1;
314 		} else
315 			eproc.e_tdev = NODEV;
316 		eproc.e_flag = sess.s_ttyvp ? EPROC_CTTY : 0;
317 		if (sess.s_leader == p)
318 			eproc.e_flag |= EPROC_SLEADER;
319 		if (proc.p_wmesg)
320 			(void)kvm_read(kd, (u_long)proc.p_wmesg,
321 			    eproc.e_wmesg, WMESGLEN);
322 
323 		(void)kvm_read(kd, (u_long)proc.p_vmspace,
324 		    &eproc.e_vm, sizeof(eproc.e_vm));
325 
326 		eproc.e_xsize = eproc.e_xrssize = 0;
327 		eproc.e_xccount = eproc.e_xswrss = 0;
328 
329 		switch (what) {
330 
331 		case KERN_PROC_PGRP:
332 			if (eproc.e_pgid != (pid_t)arg)
333 				continue;
334 			break;
335 
336 		case KERN_PROC_TTY:
337 			if ((proc.p_flag & P_CONTROLT) == 0 ||
338 			     eproc.e_tdev != (dev_t)arg)
339 				continue;
340 			break;
341 		}
342 		bcopy(&proc, &bp->kp_proc, sizeof(proc));
343 		bcopy(&eproc, &bp->kp_eproc, sizeof(eproc));
344 		++bp;
345 		++cnt;
346 	}
347 	return (cnt);
348 }
349 
350 /*
351  * Build proc info array by reading in proc list from a crash dump.
352  * Return number of procs read.  maxcnt is the max we will read.
353  */
354 static int
355 kvm_deadprocs(kd, what, arg, a_allproc, a_zombproc, maxcnt)
356 	kvm_t *kd;
357 	int what, arg;
358 	u_long a_allproc;
359 	u_long a_zombproc;
360 	int maxcnt;
361 {
362 	struct kinfo_proc *bp = kd->procbase;
363 	int acnt, zcnt;
364 	struct proc *p;
365 
366 	if (KREAD(kd, a_allproc, &p)) {
367 		_kvm_err(kd, kd->program, "cannot read allproc");
368 		return (-1);
369 	}
370 	acnt = kvm_proclist(kd, what, arg, p, bp, maxcnt);
371 	if (acnt < 0)
372 		return (acnt);
373 
374 	if (KREAD(kd, a_zombproc, &p)) {
375 		_kvm_err(kd, kd->program, "cannot read zombproc");
376 		return (-1);
377 	}
378 	zcnt = kvm_proclist(kd, what, arg, p, bp + acnt, maxcnt - acnt);
379 	if (zcnt < 0)
380 		zcnt = 0;
381 
382 	return (acnt + zcnt);
383 }
384 
385 struct kinfo_proc *
386 kvm_getprocs(kd, op, arg, cnt)
387 	kvm_t *kd;
388 	int op, arg;
389 	int *cnt;
390 {
391 	size_t size;
392 	int mib[4], st, nprocs;
393 
394 	if (kd->procbase != 0) {
395 		free((void *)kd->procbase);
396 		/*
397 		 * Clear this pointer in case this call fails.  Otherwise,
398 		 * kvm_close() will free it again.
399 		 */
400 		kd->procbase = 0;
401 	}
402 	if (ISALIVE(kd)) {
403 		size = 0;
404 		mib[0] = CTL_KERN;
405 		mib[1] = KERN_PROC;
406 		mib[2] = op;
407 		mib[3] = arg;
408 		st = sysctl(mib, 4, NULL, &size, NULL, 0);
409 		if (st == -1) {
410 			_kvm_syserr(kd, kd->program, "kvm_getprocs");
411 			return (0);
412 		}
413 		kd->procbase = (struct kinfo_proc *)_kvm_malloc(kd, size);
414 		if (kd->procbase == 0)
415 			return (0);
416 		st = sysctl(mib, 4, kd->procbase, &size, NULL, 0);
417 		if (st == -1) {
418 			_kvm_syserr(kd, kd->program, "kvm_getprocs");
419 			return (0);
420 		}
421 		if (size % sizeof(struct kinfo_proc) != 0) {
422 			_kvm_err(kd, kd->program,
423 				"proc size mismatch (%d total, %d chunks)",
424 				size, sizeof(struct kinfo_proc));
425 			return (0);
426 		}
427 		nprocs = size / sizeof(struct kinfo_proc);
428 	} else {
429 		struct nlist nl[4], *p;
430 
431 		nl[0].n_name = "_nprocs";
432 		nl[1].n_name = "_allproc";
433 		nl[2].n_name = "_zombproc";
434 		nl[3].n_name = 0;
435 
436 		if (kvm_nlist(kd, nl) != 0) {
437 			for (p = nl; p->n_type != 0; ++p)
438 				;
439 			_kvm_err(kd, kd->program,
440 				 "%s: no such symbol", p->n_name);
441 			return (0);
442 		}
443 		if (KREAD(kd, nl[0].n_value, &nprocs)) {
444 			_kvm_err(kd, kd->program, "can't read nprocs");
445 			return (0);
446 		}
447 		size = nprocs * sizeof(struct kinfo_proc);
448 		kd->procbase = (struct kinfo_proc *)_kvm_malloc(kd, size);
449 		if (kd->procbase == 0)
450 			return (0);
451 
452 		nprocs = kvm_deadprocs(kd, op, arg, nl[1].n_value,
453 				      nl[2].n_value, nprocs);
454 #ifdef notdef
455 		size = nprocs * sizeof(struct kinfo_proc);
456 		(void)realloc(kd->procbase, size);
457 #endif
458 	}
459 	*cnt = nprocs;
460 	return (kd->procbase);
461 }
462 
463 void
464 _kvm_freeprocs(kd)
465 	kvm_t *kd;
466 {
467 	if (kd->procbase) {
468 		free(kd->procbase);
469 		kd->procbase = 0;
470 	}
471 }
472 
473 void *
474 _kvm_realloc(kd, p, n)
475 	kvm_t *kd;
476 	void *p;
477 	size_t n;
478 {
479 	void *np = (void *)realloc(p, n);
480 
481 	if (np == 0)
482 		_kvm_err(kd, kd->program, "out of memory");
483 	return (np);
484 }
485 
486 #ifndef MAX
487 #define MAX(a, b) ((a) > (b) ? (a) : (b))
488 #endif
489 
490 /*
491  * Read in an argument vector from the user address space of process p.
492  * addr if the user-space base address of narg null-terminated contiguous
493  * strings.  This is used to read in both the command arguments and
494  * environment strings.  Read at most maxcnt characters of strings.
495  */
496 static char **
497 kvm_argv(kd, p, addr, narg, maxcnt)
498 	kvm_t *kd;
499 	const struct proc *p;
500 	u_long addr;
501 	int narg;
502 	int maxcnt;
503 {
504 	char *np, *cp, *ep, *ap;
505 	u_long oaddr = -1;
506 	int len, cc;
507 	char **argv;
508 
509 	/*
510 	 * Check that there aren't an unreasonable number of agruments,
511 	 * and that the address is in user space.
512 	 */
513 	if (narg > ARG_MAX || addr < VM_MIN_ADDRESS || addr >= VM_MAXUSER_ADDRESS)
514 		return (0);
515 
516 	if (kd->argv == 0) {
517 		/*
518 		 * Try to avoid reallocs.
519 		 */
520 		kd->argc = MAX(narg + 1, 32);
521 		kd->argv = (char **)_kvm_malloc(kd, kd->argc *
522 						sizeof(*kd->argv));
523 		if (kd->argv == 0)
524 			return (0);
525 	} else if (narg + 1 > kd->argc) {
526 		kd->argc = MAX(2 * kd->argc, narg + 1);
527 		kd->argv = (char **)_kvm_realloc(kd, kd->argv, kd->argc *
528 						sizeof(*kd->argv));
529 		if (kd->argv == 0)
530 			return (0);
531 	}
532 	if (kd->argspc == 0) {
533 		kd->argspc = (char *)_kvm_malloc(kd, kd->nbpg);
534 		if (kd->argspc == 0)
535 			return (0);
536 		kd->arglen = kd->nbpg;
537 	}
538 	if (kd->argbuf == 0) {
539 		kd->argbuf = (char *)_kvm_malloc(kd, kd->nbpg);
540 		if (kd->argbuf == 0)
541 			return (0);
542 	}
543 	cc = sizeof(char *) * narg;
544 	if (kvm_uread(kd, p, addr, (char *)kd->argv, cc) != cc)
545 		return (0);
546 	ap = np = kd->argspc;
547 	argv = kd->argv;
548 	len = 0;
549 	/*
550 	 * Loop over pages, filling in the argument vector.
551 	 */
552 	while (argv < kd->argv + narg && *argv != 0) {
553 		addr = (u_long)*argv & ~(kd->nbpg - 1);
554 		if (addr != oaddr) {
555 			if (kvm_uread(kd, p, addr, kd->argbuf, kd->nbpg) !=
556 			    kd->nbpg)
557 				return (0);
558 			oaddr = addr;
559 		}
560 		addr = (u_long)*argv & (kd->nbpg - 1);
561 		cp = kd->argbuf + addr;
562 		cc = kd->nbpg - addr;
563 		if (maxcnt > 0 && cc > maxcnt - len)
564 			cc = maxcnt - len;;
565 		ep = memchr(cp, '\0', cc);
566 		if (ep != 0)
567 			cc = ep - cp + 1;
568 		if (len + cc > kd->arglen) {
569 			int off;
570 			char **pp;
571 			char *op = kd->argspc;
572 
573 			kd->arglen *= 2;
574 			kd->argspc = (char *)_kvm_realloc(kd, kd->argspc,
575 							  kd->arglen);
576 			if (kd->argspc == 0)
577 				return (0);
578 			/*
579 			 * Adjust argv pointers in case realloc moved
580 			 * the string space.
581 			 */
582 			off = kd->argspc - op;
583 			for (pp = kd->argv; pp < argv; pp++)
584 				*pp += off;
585 			ap += off;
586 			np += off;
587 		}
588 		memcpy(np, cp, cc);
589 		np += cc;
590 		len += cc;
591 		if (ep != 0) {
592 			*argv++ = ap;
593 			ap = np;
594 		} else
595 			*argv += cc;
596 		if (maxcnt > 0 && len >= maxcnt) {
597 			/*
598 			 * We're stopping prematurely.  Terminate the
599 			 * current string.
600 			 */
601 			if (ep == 0) {
602 				*np = '\0';
603 				*argv++ = ap;
604 			}
605 			break;
606 		}
607 	}
608 	/* Make sure argv is terminated. */
609 	*argv = 0;
610 	return (kd->argv);
611 }
612 
613 static void
614 ps_str_a(p, addr, n)
615 	struct ps_strings *p;
616 	u_long *addr;
617 	int *n;
618 {
619 	*addr = (u_long)p->ps_argvstr;
620 	*n = p->ps_nargvstr;
621 }
622 
623 static void
624 ps_str_e(p, addr, n)
625 	struct ps_strings *p;
626 	u_long *addr;
627 	int *n;
628 {
629 	*addr = (u_long)p->ps_envstr;
630 	*n = p->ps_nenvstr;
631 }
632 
633 /*
634  * Determine if the proc indicated by p is still active.
635  * This test is not 100% foolproof in theory, but chances of
636  * being wrong are very low.
637  */
638 static int
639 proc_verify(kd, kernp, p)
640 	kvm_t *kd;
641 	u_long kernp;
642 	const struct proc *p;
643 {
644 	struct proc kernproc;
645 
646 	/*
647 	 * Just read in the whole proc.  It's not that big relative
648 	 * to the cost of the read system call.
649 	 */
650 	if (kvm_read(kd, kernp, &kernproc, sizeof(kernproc)) !=
651 	    sizeof(kernproc))
652 		return (0);
653 	return (p->p_pid == kernproc.p_pid &&
654 		(kernproc.p_stat != SZOMB || p->p_stat == SZOMB));
655 }
656 
657 static char **
658 kvm_doargv(kd, kp, nchr, info)
659 	kvm_t *kd;
660 	const struct kinfo_proc *kp;
661 	int nchr;
662 	void (*info)(struct ps_strings *, u_long *, int *);
663 {
664 	const struct proc *p = &kp->kp_proc;
665 	char **ap;
666 	u_long addr;
667 	int cnt;
668 	struct ps_strings arginfo;
669 	static struct ps_strings *ps;
670 
671 	if (ps == NULL) {
672 		struct _ps_strings _ps;
673 		int mib[2];
674 		size_t len;
675 
676 		mib[0] = CTL_VM;
677 		mib[1] = VM_PSSTRINGS;
678 		len = sizeof(_ps);
679 		sysctl(mib, 2, &_ps, &len, NULL, 0);
680 		ps = (struct ps_strings *)_ps.val;
681 	}
682 
683 	/*
684 	 * Pointers are stored at the top of the user stack.
685 	 */
686 	if (p->p_stat == SZOMB ||
687 	    kvm_uread(kd, p, (u_long)ps, (char *)&arginfo,
688 		      sizeof(arginfo)) != sizeof(arginfo))
689 		return (0);
690 
691 	(*info)(&arginfo, &addr, &cnt);
692 	if (cnt == 0)
693 		return (0);
694 	ap = kvm_argv(kd, p, addr, cnt, nchr);
695 	/*
696 	 * For live kernels, make sure this process didn't go away.
697 	 */
698 	if (ap != 0 && ISALIVE(kd) &&
699 	    !proc_verify(kd, (u_long)kp->kp_eproc.e_paddr, p))
700 		ap = 0;
701 	return (ap);
702 }
703 
704 /*
705  * Get the command args.  This code is now machine independent.
706  */
707 char **
708 kvm_getargv(kd, kp, nchr)
709 	kvm_t *kd;
710 	const struct kinfo_proc *kp;
711 	int nchr;
712 {
713 	return (kvm_doargv(kd, kp, nchr, ps_str_a));
714 }
715 
716 char **
717 kvm_getenvv(kd, kp, nchr)
718 	kvm_t *kd;
719 	const struct kinfo_proc *kp;
720 	int nchr;
721 {
722 	return (kvm_doargv(kd, kp, nchr, ps_str_e));
723 }
724 
725 /*
726  * Read from user space.  The user context is given by p.
727  */
728 ssize_t
729 kvm_uread(kd, p, uva, buf, len)
730 	kvm_t *kd;
731 	const struct proc *p;
732 	u_long uva;
733 	char *buf;
734 	size_t len;
735 {
736 	char *cp;
737 
738 	cp = buf;
739 	while (len > 0) {
740 		int cc;
741 		char *dp;
742 		u_long cnt;
743 
744 		dp = _kvm_uread(kd, p, uva, &cnt);
745 		if (dp == 0) {
746 			_kvm_err(kd, 0, "invalid address (%lx)", uva);
747 			return (0);
748 		}
749 		cc = MIN(cnt, len);
750 		bcopy(dp, cp, cc);
751 
752 		cp += cc;
753 		uva += cc;
754 		len -= cc;
755 	}
756 	return (ssize_t)(cp - buf);
757 }
758