xref: /freebsd/lib/libkvm/kvm_proc.c (revision f0a75d274af375d15b97b830966b99a02b7db911)
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 #define	_WANT_PRISON	/* make jail.h give us 'struct prison' */
58 #include <sys/jail.h>
59 #include <sys/user.h>
60 #include <sys/proc.h>
61 #include <sys/exec.h>
62 #include <sys/stat.h>
63 #include <sys/sysent.h>
64 #include <sys/ioctl.h>
65 #include <sys/tty.h>
66 #include <sys/file.h>
67 #include <sys/conf.h>
68 #include <stdio.h>
69 #include <stdlib.h>
70 #include <unistd.h>
71 #include <nlist.h>
72 #include <kvm.h>
73 
74 #include <vm/vm.h>
75 #include <vm/vm_param.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 
88 /*
89  * Read proc's from memory file into buffer bp, which has space to hold
90  * at most maxcnt procs.
91  */
92 static int
93 kvm_proclist(kd, what, arg, p, bp, maxcnt)
94 	kvm_t *kd;
95 	int what, arg;
96 	struct proc *p;
97 	struct kinfo_proc *bp;
98 	int maxcnt;
99 {
100 	int cnt = 0;
101 	struct kinfo_proc kinfo_proc, *kp;
102 	struct pgrp pgrp;
103 	struct session sess;
104 	struct cdev t_cdev;
105 	struct tty tty;
106 	struct vmspace vmspace;
107 	struct sigacts sigacts;
108 	struct pstats pstats;
109 	struct ucred ucred;
110 	struct prison pr;
111 	struct thread mtd;
112 	struct proc proc;
113 	struct proc pproc;
114 	struct timeval tv;
115 	struct sysentvec sysent;
116 	char svname[KI_EMULNAMELEN];
117 
118 	kp = &kinfo_proc;
119 	kp->ki_structsize = sizeof(kinfo_proc);
120 	for (; cnt < maxcnt && p != NULL; p = LIST_NEXT(&proc, p_list)) {
121 		memset(kp, 0, sizeof *kp);
122 		if (KREAD(kd, (u_long)p, &proc)) {
123 			_kvm_err(kd, kd->program, "can't read proc at %x", p);
124 			return (-1);
125 		}
126 		if (proc.p_state != PRS_ZOMBIE) {
127 			if (KREAD(kd, (u_long)TAILQ_FIRST(&proc.p_threads),
128 			    &mtd)) {
129 				_kvm_err(kd, kd->program,
130 				    "can't read thread at %x",
131 				    TAILQ_FIRST(&proc.p_threads));
132 				return (-1);
133 			}
134 		}
135 		if (KREAD(kd, (u_long)proc.p_ucred, &ucred) == 0) {
136 			kp->ki_ruid = ucred.cr_ruid;
137 			kp->ki_svuid = ucred.cr_svuid;
138 			kp->ki_rgid = ucred.cr_rgid;
139 			kp->ki_svgid = ucred.cr_svgid;
140 			kp->ki_ngroups = ucred.cr_ngroups;
141 			bcopy(ucred.cr_groups, kp->ki_groups,
142 			    NGROUPS * sizeof(gid_t));
143 			kp->ki_uid = ucred.cr_uid;
144 			if (ucred.cr_prison != NULL) {
145 				if (KREAD(kd, (u_long)ucred.cr_prison, &pr)) {
146 					_kvm_err(kd, kd->program,
147 					    "can't read prison at %x",
148 					    ucred.cr_prison);
149 					return (-1);
150 				}
151 				kp->ki_jid = pr.pr_id;
152 			}
153 		}
154 
155 		switch(what & ~KERN_PROC_INC_THREAD) {
156 
157 		case KERN_PROC_GID:
158 			if (kp->ki_groups[0] != (gid_t)arg)
159 				continue;
160 			break;
161 
162 		case KERN_PROC_PID:
163 			if (proc.p_pid != (pid_t)arg)
164 				continue;
165 			break;
166 
167 		case KERN_PROC_RGID:
168 			if (kp->ki_rgid != (gid_t)arg)
169 				continue;
170 			break;
171 
172 		case KERN_PROC_UID:
173 			if (kp->ki_uid != (uid_t)arg)
174 				continue;
175 			break;
176 
177 		case KERN_PROC_RUID:
178 			if (kp->ki_ruid != (uid_t)arg)
179 				continue;
180 			break;
181 		}
182 		/*
183 		 * We're going to add another proc to the set.  If this
184 		 * will overflow the buffer, assume the reason is because
185 		 * nprocs (or the proc list) is corrupt and declare an error.
186 		 */
187 		if (cnt >= maxcnt) {
188 			_kvm_err(kd, kd->program, "nprocs corrupt");
189 			return (-1);
190 		}
191 		/*
192 		 * gather kinfo_proc
193 		 */
194 		kp->ki_paddr = p;
195 		kp->ki_addr = 0;	/* XXX uarea */
196 		/* kp->ki_kstack = proc.p_thread.td_kstack; XXXKSE */
197 		kp->ki_args = proc.p_args;
198 		kp->ki_tracep = proc.p_tracevp;
199 		kp->ki_textvp = proc.p_textvp;
200 		kp->ki_fd = proc.p_fd;
201 		kp->ki_vmspace = proc.p_vmspace;
202 		if (proc.p_sigacts != NULL) {
203 			if (KREAD(kd, (u_long)proc.p_sigacts, &sigacts)) {
204 				_kvm_err(kd, kd->program,
205 				    "can't read sigacts at %x", proc.p_sigacts);
206 				return (-1);
207 			}
208 			kp->ki_sigignore = sigacts.ps_sigignore;
209 			kp->ki_sigcatch = sigacts.ps_sigcatch;
210 		}
211 		if ((proc.p_sflag & PS_INMEM) && proc.p_stats != NULL) {
212 			if (KREAD(kd, (u_long)proc.p_stats, &pstats)) {
213 				_kvm_err(kd, kd->program,
214 				    "can't read stats at %x", proc.p_stats);
215 				return (-1);
216 			}
217 			kp->ki_start = pstats.p_start;
218 
219 			/*
220 			 * XXX: The times here are probably zero and need
221 			 * to be calculated from the raw data in p_rux and
222 			 * p_crux.
223 			 */
224 			kp->ki_rusage = pstats.p_ru;
225 			kp->ki_childstime = pstats.p_cru.ru_stime;
226 			kp->ki_childutime = pstats.p_cru.ru_utime;
227 			/* Some callers want child-times in a single value */
228 			timeradd(&kp->ki_childstime, &kp->ki_childutime,
229 			    &kp->ki_childtime);
230 		}
231 		if (proc.p_oppid)
232 			kp->ki_ppid = proc.p_oppid;
233 		else if (proc.p_pptr) {
234 			if (KREAD(kd, (u_long)proc.p_pptr, &pproc)) {
235 				_kvm_err(kd, kd->program,
236 				    "can't read pproc at %x", proc.p_pptr);
237 				return (-1);
238 			}
239 			kp->ki_ppid = pproc.p_pid;
240 		} else
241 			kp->ki_ppid = 0;
242 		if (proc.p_pgrp == NULL)
243 			goto nopgrp;
244 		if (KREAD(kd, (u_long)proc.p_pgrp, &pgrp)) {
245 			_kvm_err(kd, kd->program, "can't read pgrp at %x",
246 				 proc.p_pgrp);
247 			return (-1);
248 		}
249 		kp->ki_pgid = pgrp.pg_id;
250 		kp->ki_jobc = pgrp.pg_jobc;
251 		if (KREAD(kd, (u_long)pgrp.pg_session, &sess)) {
252 			_kvm_err(kd, kd->program, "can't read session at %x",
253 				pgrp.pg_session);
254 			return (-1);
255 		}
256 		kp->ki_sid = sess.s_sid;
257 		(void)memcpy(kp->ki_login, sess.s_login,
258 						sizeof(kp->ki_login));
259 		kp->ki_kiflag = sess.s_ttyvp ? KI_CTTY : 0;
260 		if (sess.s_leader == p)
261 			kp->ki_kiflag |= KI_SLEADER;
262 		if ((proc.p_flag & P_CONTROLT) && sess.s_ttyp != NULL) {
263 			if (KREAD(kd, (u_long)sess.s_ttyp, &tty)) {
264 				_kvm_err(kd, kd->program,
265 					 "can't read tty at %x", sess.s_ttyp);
266 				return (-1);
267 			}
268 			if (tty.t_dev != NULL) {
269 				if (KREAD(kd, (u_long)tty.t_dev, &t_cdev)) {
270 					_kvm_err(kd, kd->program,
271 						 "can't read cdev at %x",
272 						tty.t_dev);
273 					return (-1);
274 				}
275 #if 0
276 				kp->ki_tdev = t_cdev.si_udev;
277 #else
278 				kp->ki_tdev = NODEV;
279 #endif
280 			}
281 			if (tty.t_pgrp != NULL) {
282 				if (KREAD(kd, (u_long)tty.t_pgrp, &pgrp)) {
283 					_kvm_err(kd, kd->program,
284 						 "can't read tpgrp at %x",
285 						tty.t_pgrp);
286 					return (-1);
287 				}
288 				kp->ki_tpgid = pgrp.pg_id;
289 			} else
290 				kp->ki_tpgid = -1;
291 			if (tty.t_session != NULL) {
292 				if (KREAD(kd, (u_long)tty.t_session, &sess)) {
293 					_kvm_err(kd, kd->program,
294 					    "can't read session at %x",
295 					    tty.t_session);
296 					return (-1);
297 				}
298 				kp->ki_tsid = sess.s_sid;
299 			}
300 		} else {
301 nopgrp:
302 			kp->ki_tdev = NODEV;
303 		}
304 		if ((proc.p_state != PRS_ZOMBIE) && mtd.td_wmesg)
305 			(void)kvm_read(kd, (u_long)mtd.td_wmesg,
306 			    kp->ki_wmesg, WMESGLEN);
307 
308 		(void)kvm_read(kd, (u_long)proc.p_vmspace,
309 		    (char *)&vmspace, sizeof(vmspace));
310 		kp->ki_size = vmspace.vm_map.size;
311 		kp->ki_rssize = vmspace.vm_swrss; /* XXX */
312 		kp->ki_swrss = vmspace.vm_swrss;
313 		kp->ki_tsize = vmspace.vm_tsize;
314 		kp->ki_dsize = vmspace.vm_dsize;
315 		kp->ki_ssize = vmspace.vm_ssize;
316 
317 		switch (what & ~KERN_PROC_INC_THREAD) {
318 
319 		case KERN_PROC_PGRP:
320 			if (kp->ki_pgid != (pid_t)arg)
321 				continue;
322 			break;
323 
324 		case KERN_PROC_SESSION:
325 			if (kp->ki_sid != (pid_t)arg)
326 				continue;
327 			break;
328 
329 		case KERN_PROC_TTY:
330 			if ((proc.p_flag & P_CONTROLT) == 0 ||
331 			     kp->ki_tdev != (dev_t)arg)
332 				continue;
333 			break;
334 		}
335 		if (proc.p_comm[0] != 0)
336 			strlcpy(kp->ki_comm, proc.p_comm, MAXCOMLEN);
337 		(void)kvm_read(kd, (u_long)proc.p_sysent, (char *)&sysent,
338 		    sizeof(sysent));
339 		(void)kvm_read(kd, (u_long)sysent.sv_name, (char *)&svname,
340 		    sizeof(svname));
341 		if (svname[0] != 0)
342 			strlcpy(kp->ki_emul, svname, KI_EMULNAMELEN);
343 		if ((proc.p_state != PRS_ZOMBIE) &&
344 		    (mtd.td_blocked != 0)) {
345 			kp->ki_kiflag |= KI_LOCKBLOCK;
346 			if (mtd.td_lockname)
347 				(void)kvm_read(kd,
348 				    (u_long)mtd.td_lockname,
349 				    kp->ki_lockname, LOCKNAMELEN);
350 			kp->ki_lockname[LOCKNAMELEN] = 0;
351 		}
352 		/*
353 		 * XXX: This is plain wrong, rux_runtime has nothing
354 		 * to do with struct bintime, rux_runtime is just a 64-bit
355 		 * integer counter of cputicks.  What we need here is a way
356 		 * to convert cputicks to usecs.  The kernel does it in
357 		 * kern/kern_tc.c, but the function can't be just copied.
358 		 */
359 		bintime2timeval(&proc.p_rux.rux_runtime, &tv);
360 		kp->ki_runtime = (u_int64_t)tv.tv_sec * 1000000 + tv.tv_usec;
361 		kp->ki_pid = proc.p_pid;
362 		kp->ki_siglist = proc.p_siglist;
363 		SIGSETOR(kp->ki_siglist, mtd.td_siglist);
364 		kp->ki_sigmask = mtd.td_sigmask;
365 		kp->ki_xstat = proc.p_xstat;
366 		kp->ki_acflag = proc.p_acflag;
367 		kp->ki_lock = proc.p_lock;
368 		if (proc.p_state != PRS_ZOMBIE) {
369 			kp->ki_swtime = proc.p_swtime;
370 			kp->ki_flag = proc.p_flag;
371 			kp->ki_sflag = proc.p_sflag;
372 			kp->ki_nice = proc.p_nice;
373 			kp->ki_traceflag = proc.p_traceflag;
374 			if (proc.p_state == PRS_NORMAL) {
375 				if (TD_ON_RUNQ(&mtd) ||
376 				    TD_CAN_RUN(&mtd) ||
377 				    TD_IS_RUNNING(&mtd)) {
378 					kp->ki_stat = SRUN;
379 				} else if (mtd.td_state ==
380 				    TDS_INHIBITED) {
381 					if (P_SHOULDSTOP(&proc)) {
382 						kp->ki_stat = SSTOP;
383 					} else if (
384 					    TD_IS_SLEEPING(&mtd)) {
385 						kp->ki_stat = SSLEEP;
386 					} else if (TD_ON_LOCK(&mtd)) {
387 						kp->ki_stat = SLOCK;
388 					} else {
389 						kp->ki_stat = SWAIT;
390 					}
391 				}
392 			} else {
393 				kp->ki_stat = SIDL;
394 			}
395 			/* Stuff from the thread */
396 			kp->ki_pri.pri_level = mtd.td_priority;
397 			kp->ki_pri.pri_native = mtd.td_base_pri;
398 			kp->ki_lastcpu = mtd.td_lastcpu;
399 			kp->ki_wchan = mtd.td_wchan;
400 			kp->ki_oncpu = mtd.td_oncpu;
401 
402 			if (!(proc.p_flag & P_SA)) {
403 				kp->ki_pctcpu = 0;
404 				kp->ki_rqindex = 0;
405 			} else {
406 				kp->ki_tdflags = -1;
407 				/* All the rest are 0 for now */
408 			}
409 		} else {
410 			kp->ki_stat = SZOMB;
411 		}
412 		bcopy(&kinfo_proc, bp, sizeof(kinfo_proc));
413 		++bp;
414 		++cnt;
415 	}
416 	return (cnt);
417 }
418 
419 /*
420  * Build proc info array by reading in proc list from a crash dump.
421  * Return number of procs read.  maxcnt is the max we will read.
422  */
423 static int
424 kvm_deadprocs(kd, what, arg, a_allproc, a_zombproc, maxcnt)
425 	kvm_t *kd;
426 	int what, arg;
427 	u_long a_allproc;
428 	u_long a_zombproc;
429 	int maxcnt;
430 {
431 	struct kinfo_proc *bp = kd->procbase;
432 	int acnt, zcnt;
433 	struct proc *p;
434 
435 	if (KREAD(kd, a_allproc, &p)) {
436 		_kvm_err(kd, kd->program, "cannot read allproc");
437 		return (-1);
438 	}
439 	acnt = kvm_proclist(kd, what, arg, p, bp, maxcnt);
440 	if (acnt < 0)
441 		return (acnt);
442 
443 	if (KREAD(kd, a_zombproc, &p)) {
444 		_kvm_err(kd, kd->program, "cannot read zombproc");
445 		return (-1);
446 	}
447 	zcnt = kvm_proclist(kd, what, arg, p, bp + acnt, maxcnt - acnt);
448 	if (zcnt < 0)
449 		zcnt = 0;
450 
451 	return (acnt + zcnt);
452 }
453 
454 struct kinfo_proc *
455 kvm_getprocs(kd, op, arg, cnt)
456 	kvm_t *kd;
457 	int op, arg;
458 	int *cnt;
459 {
460 	int mib[4], st, nprocs;
461 	size_t size;
462 	int temp_op;
463 
464 	if (kd->procbase != 0) {
465 		free((void *)kd->procbase);
466 		/*
467 		 * Clear this pointer in case this call fails.  Otherwise,
468 		 * kvm_close() will free it again.
469 		 */
470 		kd->procbase = 0;
471 	}
472 	if (ISALIVE(kd)) {
473 		size = 0;
474 		mib[0] = CTL_KERN;
475 		mib[1] = KERN_PROC;
476 		mib[2] = op;
477 		mib[3] = arg;
478 		temp_op = op & ~KERN_PROC_INC_THREAD;
479 		st = sysctl(mib,
480 		    temp_op == KERN_PROC_ALL || temp_op == KERN_PROC_PROC ?
481 		    3 : 4, NULL, &size, NULL, 0);
482 		if (st == -1) {
483 			_kvm_syserr(kd, kd->program, "kvm_getprocs");
484 			return (0);
485 		}
486 		/*
487 		 * We can't continue with a size of 0 because we pass
488 		 * it to realloc() (via _kvm_realloc()), and passing 0
489 		 * to realloc() results in undefined behavior.
490 		 */
491 		if (size == 0) {
492 			/*
493 			 * XXX: We should probably return an invalid,
494 			 * but non-NULL, pointer here so any client
495 			 * program trying to dereference it will
496 			 * crash.  However, _kvm_freeprocs() calls
497 			 * free() on kd->procbase if it isn't NULL,
498 			 * and free()'ing a junk pointer isn't good.
499 			 * Then again, _kvm_freeprocs() isn't used
500 			 * anywhere . . .
501 			 */
502 			kd->procbase = _kvm_malloc(kd, 1);
503 			goto liveout;
504 		}
505 		do {
506 			size += size / 10;
507 			kd->procbase = (struct kinfo_proc *)
508 			    _kvm_realloc(kd, kd->procbase, size);
509 			if (kd->procbase == 0)
510 				return (0);
511 			st = sysctl(mib, temp_op == KERN_PROC_ALL ||
512 			    temp_op == KERN_PROC_PROC ? 3 : 4,
513 			    kd->procbase, &size, NULL, 0);
514 		} while (st == -1 && errno == ENOMEM);
515 		if (st == -1) {
516 			_kvm_syserr(kd, kd->program, "kvm_getprocs");
517 			return (0);
518 		}
519 		/*
520 		 * We have to check the size again because sysctl()
521 		 * may "round up" oldlenp if oldp is NULL; hence it
522 		 * might've told us that there was data to get when
523 		 * there really isn't any.
524 		 */
525 		if (size > 0 &&
526 		    kd->procbase->ki_structsize != sizeof(struct kinfo_proc)) {
527 			_kvm_err(kd, kd->program,
528 			    "kinfo_proc size mismatch (expected %d, got %d)",
529 			    sizeof(struct kinfo_proc),
530 			    kd->procbase->ki_structsize);
531 			return (0);
532 		}
533 liveout:
534 		nprocs = size == 0 ? 0 : size / kd->procbase->ki_structsize;
535 	} else {
536 		struct nlist nl[4], *p;
537 
538 		nl[0].n_name = "_nprocs";
539 		nl[1].n_name = "_allproc";
540 		nl[2].n_name = "_zombproc";
541 		nl[3].n_name = 0;
542 
543 		if (kvm_nlist(kd, nl) != 0) {
544 			for (p = nl; p->n_type != 0; ++p)
545 				;
546 			_kvm_err(kd, kd->program,
547 				 "%s: no such symbol", p->n_name);
548 			return (0);
549 		}
550 		if (KREAD(kd, nl[0].n_value, &nprocs)) {
551 			_kvm_err(kd, kd->program, "can't read nprocs");
552 			return (0);
553 		}
554 		size = nprocs * sizeof(struct kinfo_proc);
555 		kd->procbase = (struct kinfo_proc *)_kvm_malloc(kd, size);
556 		if (kd->procbase == 0)
557 			return (0);
558 
559 		nprocs = kvm_deadprocs(kd, op, arg, nl[1].n_value,
560 				      nl[2].n_value, nprocs);
561 #ifdef notdef
562 		size = nprocs * sizeof(struct kinfo_proc);
563 		(void)realloc(kd->procbase, size);
564 #endif
565 	}
566 	*cnt = nprocs;
567 	return (kd->procbase);
568 }
569 
570 void
571 _kvm_freeprocs(kd)
572 	kvm_t *kd;
573 {
574 	if (kd->procbase) {
575 		free(kd->procbase);
576 		kd->procbase = 0;
577 	}
578 }
579 
580 void *
581 _kvm_realloc(kd, p, n)
582 	kvm_t *kd;
583 	void *p;
584 	size_t n;
585 {
586 	void *np = (void *)realloc(p, n);
587 
588 	if (np == 0) {
589 		free(p);
590 		_kvm_err(kd, kd->program, "out of memory");
591 	}
592 	return (np);
593 }
594 
595 #ifndef MAX
596 #define MAX(a, b) ((a) > (b) ? (a) : (b))
597 #endif
598 
599 /*
600  * Read in an argument vector from the user address space of process kp.
601  * addr if the user-space base address of narg null-terminated contiguous
602  * strings.  This is used to read in both the command arguments and
603  * environment strings.  Read at most maxcnt characters of strings.
604  */
605 static char **
606 kvm_argv(kd, kp, addr, narg, maxcnt)
607 	kvm_t *kd;
608 	struct kinfo_proc *kp;
609 	u_long addr;
610 	int narg;
611 	int maxcnt;
612 {
613 	char *np, *cp, *ep, *ap;
614 	u_long oaddr = -1;
615 	int len, cc;
616 	char **argv;
617 
618 	/*
619 	 * Check that there aren't an unreasonable number of agruments,
620 	 * and that the address is in user space.
621 	 */
622 	if (narg > 512 || addr < VM_MIN_ADDRESS || addr >= VM_MAXUSER_ADDRESS)
623 		return (0);
624 
625 	/*
626 	 * kd->argv : work space for fetching the strings from the target
627 	 *            process's space, and is converted for returning to caller
628 	 */
629 	if (kd->argv == 0) {
630 		/*
631 		 * Try to avoid reallocs.
632 		 */
633 		kd->argc = MAX(narg + 1, 32);
634 		kd->argv = (char **)_kvm_malloc(kd, kd->argc *
635 						sizeof(*kd->argv));
636 		if (kd->argv == 0)
637 			return (0);
638 	} else if (narg + 1 > kd->argc) {
639 		kd->argc = MAX(2 * kd->argc, narg + 1);
640 		kd->argv = (char **)_kvm_realloc(kd, kd->argv, kd->argc *
641 						sizeof(*kd->argv));
642 		if (kd->argv == 0)
643 			return (0);
644 	}
645 	/*
646 	 * kd->argspc : returned to user, this is where the kd->argv
647 	 *              arrays are left pointing to the collected strings.
648 	 */
649 	if (kd->argspc == 0) {
650 		kd->argspc = (char *)_kvm_malloc(kd, PAGE_SIZE);
651 		if (kd->argspc == 0)
652 			return (0);
653 		kd->arglen = PAGE_SIZE;
654 	}
655 	/*
656 	 * kd->argbuf : used to pull in pages from the target process.
657 	 *              the strings are copied out of here.
658 	 */
659 	if (kd->argbuf == 0) {
660 		kd->argbuf = (char *)_kvm_malloc(kd, PAGE_SIZE);
661 		if (kd->argbuf == 0)
662 			return (0);
663 	}
664 
665 	/* Pull in the target process'es argv vector */
666 	cc = sizeof(char *) * narg;
667 	if (kvm_uread(kd, kp, addr, (char *)kd->argv, cc) != cc)
668 		return (0);
669 	/*
670 	 * ap : saved start address of string we're working on in kd->argspc
671 	 * np : pointer to next place to write in kd->argspc
672 	 * len: length of data in kd->argspc
673 	 * argv: pointer to the argv vector that we are hunting around the
674 	 *       target process space for, and converting to addresses in
675 	 *       our address space (kd->argspc).
676 	 */
677 	ap = np = kd->argspc;
678 	argv = kd->argv;
679 	len = 0;
680 	/*
681 	 * Loop over pages, filling in the argument vector.
682 	 * Note that the argv strings could be pointing *anywhere* in
683 	 * the user address space and are no longer contiguous.
684 	 * Note that *argv is modified when we are going to fetch a string
685 	 * that crosses a page boundary.  We copy the next part of the string
686 	 * into to "np" and eventually convert the pointer.
687 	 */
688 	while (argv < kd->argv + narg && *argv != 0) {
689 
690 		/* get the address that the current argv string is on */
691 		addr = (u_long)*argv & ~(PAGE_SIZE - 1);
692 
693 		/* is it the same page as the last one? */
694 		if (addr != oaddr) {
695 			if (kvm_uread(kd, kp, addr, kd->argbuf, PAGE_SIZE) !=
696 			    PAGE_SIZE)
697 				return (0);
698 			oaddr = addr;
699 		}
700 
701 		/* offset within the page... kd->argbuf */
702 		addr = (u_long)*argv & (PAGE_SIZE - 1);
703 
704 		/* cp = start of string, cc = count of chars in this chunk */
705 		cp = kd->argbuf + addr;
706 		cc = PAGE_SIZE - addr;
707 
708 		/* dont get more than asked for by user process */
709 		if (maxcnt > 0 && cc > maxcnt - len)
710 			cc = maxcnt - len;
711 
712 		/* pointer to end of string if we found it in this page */
713 		ep = memchr(cp, '\0', cc);
714 		if (ep != 0)
715 			cc = ep - cp + 1;
716 		/*
717 		 * at this point, cc is the count of the chars that we are
718 		 * going to retrieve this time. we may or may not have found
719 		 * the end of it.  (ep points to the null if the end is known)
720 		 */
721 
722 		/* will we exceed the malloc/realloced buffer? */
723 		if (len + cc > kd->arglen) {
724 			int off;
725 			char **pp;
726 			char *op = kd->argspc;
727 
728 			kd->arglen *= 2;
729 			kd->argspc = (char *)_kvm_realloc(kd, kd->argspc,
730 							  kd->arglen);
731 			if (kd->argspc == 0)
732 				return (0);
733 			/*
734 			 * Adjust argv pointers in case realloc moved
735 			 * the string space.
736 			 */
737 			off = kd->argspc - op;
738 			for (pp = kd->argv; pp < argv; pp++)
739 				*pp += off;
740 			ap += off;
741 			np += off;
742 		}
743 		/* np = where to put the next part of the string in kd->argspc*/
744 		/* np is kinda redundant.. could use "kd->argspc + len" */
745 		memcpy(np, cp, cc);
746 		np += cc;	/* inc counters */
747 		len += cc;
748 
749 		/*
750 		 * if end of string found, set the *argv pointer to the
751 		 * saved beginning of string, and advance. argv points to
752 		 * somewhere in kd->argv..  This is initially relative
753 		 * to the target process, but when we close it off, we set
754 		 * it to point in our address space.
755 		 */
756 		if (ep != 0) {
757 			*argv++ = ap;
758 			ap = np;
759 		} else {
760 			/* update the address relative to the target process */
761 			*argv += cc;
762 		}
763 
764 		if (maxcnt > 0 && len >= maxcnt) {
765 			/*
766 			 * We're stopping prematurely.  Terminate the
767 			 * current string.
768 			 */
769 			if (ep == 0) {
770 				*np = '\0';
771 				*argv++ = ap;
772 			}
773 			break;
774 		}
775 	}
776 	/* Make sure argv is terminated. */
777 	*argv = 0;
778 	return (kd->argv);
779 }
780 
781 static void
782 ps_str_a(p, addr, n)
783 	struct ps_strings *p;
784 	u_long *addr;
785 	int *n;
786 {
787 	*addr = (u_long)p->ps_argvstr;
788 	*n = p->ps_nargvstr;
789 }
790 
791 static void
792 ps_str_e(p, addr, n)
793 	struct ps_strings *p;
794 	u_long *addr;
795 	int *n;
796 {
797 	*addr = (u_long)p->ps_envstr;
798 	*n = p->ps_nenvstr;
799 }
800 
801 /*
802  * Determine if the proc indicated by p is still active.
803  * This test is not 100% foolproof in theory, but chances of
804  * being wrong are very low.
805  */
806 static int
807 proc_verify(curkp)
808 	struct kinfo_proc *curkp;
809 {
810 	struct kinfo_proc newkp;
811 	int mib[4];
812 	size_t len;
813 
814 	mib[0] = CTL_KERN;
815 	mib[1] = KERN_PROC;
816 	mib[2] = KERN_PROC_PID;
817 	mib[3] = curkp->ki_pid;
818 	len = sizeof(newkp);
819 	if (sysctl(mib, 4, &newkp, &len, NULL, 0) == -1)
820 		return (0);
821 	return (curkp->ki_pid == newkp.ki_pid &&
822 	    (newkp.ki_stat != SZOMB || curkp->ki_stat == SZOMB));
823 }
824 
825 static char **
826 kvm_doargv(kd, kp, nchr, info)
827 	kvm_t *kd;
828 	struct kinfo_proc *kp;
829 	int nchr;
830 	void (*info)(struct ps_strings *, u_long *, int *);
831 {
832 	char **ap;
833 	u_long addr;
834 	int cnt;
835 	static struct ps_strings arginfo;
836 	static u_long ps_strings;
837 	size_t len;
838 
839 	if (ps_strings == 0) {
840 		len = sizeof(ps_strings);
841 		if (sysctlbyname("kern.ps_strings", &ps_strings, &len, NULL,
842 		    0) == -1)
843 			ps_strings = PS_STRINGS;
844 	}
845 
846 	/*
847 	 * Pointers are stored at the top of the user stack.
848 	 */
849 	if (kp->ki_stat == SZOMB ||
850 	    kvm_uread(kd, kp, ps_strings, (char *)&arginfo,
851 		      sizeof(arginfo)) != sizeof(arginfo))
852 		return (0);
853 
854 	(*info)(&arginfo, &addr, &cnt);
855 	if (cnt == 0)
856 		return (0);
857 	ap = kvm_argv(kd, kp, addr, cnt, nchr);
858 	/*
859 	 * For live kernels, make sure this process didn't go away.
860 	 */
861 	if (ap != 0 && ISALIVE(kd) && !proc_verify(kp))
862 		ap = 0;
863 	return (ap);
864 }
865 
866 /*
867  * Get the command args.  This code is now machine independent.
868  */
869 char **
870 kvm_getargv(kd, kp, nchr)
871 	kvm_t *kd;
872 	const struct kinfo_proc *kp;
873 	int nchr;
874 {
875 	int oid[4];
876 	int i;
877 	size_t bufsz;
878 	static unsigned long buflen;
879 	static char *buf, *p;
880 	static char **bufp;
881 	static int argc;
882 
883 	if (!ISALIVE(kd)) {
884 		_kvm_err(kd, kd->program,
885 		    "cannot read user space from dead kernel");
886 		return (0);
887 	}
888 
889 	if (!buflen) {
890 		bufsz = sizeof(buflen);
891 		i = sysctlbyname("kern.ps_arg_cache_limit",
892 		    &buflen, &bufsz, NULL, 0);
893 		if (i == -1) {
894 			buflen = 0;
895 		} else {
896 			buf = malloc(buflen);
897 			if (buf == NULL)
898 				buflen = 0;
899 			argc = 32;
900 			bufp = malloc(sizeof(char *) * argc);
901 		}
902 	}
903 	if (buf != NULL) {
904 		oid[0] = CTL_KERN;
905 		oid[1] = KERN_PROC;
906 		oid[2] = KERN_PROC_ARGS;
907 		oid[3] = kp->ki_pid;
908 		bufsz = buflen;
909 		i = sysctl(oid, 4, buf, &bufsz, 0, 0);
910 		if (i == 0 && bufsz > 0) {
911 			i = 0;
912 			p = buf;
913 			do {
914 				bufp[i++] = p;
915 				p += strlen(p) + 1;
916 				if (i >= argc) {
917 					argc += argc;
918 					bufp = realloc(bufp,
919 					    sizeof(char *) * argc);
920 				}
921 			} while (p < buf + bufsz);
922 			bufp[i++] = 0;
923 			return (bufp);
924 		}
925 	}
926 	if (kp->ki_flag & P_SYSTEM)
927 		return (NULL);
928 	return (kvm_doargv(kd, kp, nchr, ps_str_a));
929 }
930 
931 char **
932 kvm_getenvv(kd, kp, nchr)
933 	kvm_t *kd;
934 	const struct kinfo_proc *kp;
935 	int nchr;
936 {
937 	return (kvm_doargv(kd, kp, nchr, ps_str_e));
938 }
939 
940 /*
941  * Read from user space.  The user context is given by p.
942  */
943 ssize_t
944 kvm_uread(kd, kp, uva, buf, len)
945 	kvm_t *kd;
946 	struct kinfo_proc *kp;
947 	u_long uva;
948 	char *buf;
949 	size_t len;
950 {
951 	char *cp;
952 	char procfile[MAXPATHLEN];
953 	ssize_t amount;
954 	int fd;
955 
956 	if (!ISALIVE(kd)) {
957 		_kvm_err(kd, kd->program,
958 		    "cannot read user space from dead kernel");
959 		return (0);
960 	}
961 
962 	sprintf(procfile, "/proc/%d/mem", kp->ki_pid);
963 	fd = open(procfile, O_RDONLY, 0);
964 	if (fd < 0) {
965 		_kvm_err(kd, kd->program, "cannot open %s", procfile);
966 		return (0);
967 	}
968 
969 	cp = buf;
970 	while (len > 0) {
971 		errno = 0;
972 		if (lseek(fd, (off_t)uva, 0) == -1 && errno != 0) {
973 			_kvm_err(kd, kd->program, "invalid address (%x) in %s",
974 			    uva, procfile);
975 			break;
976 		}
977 		amount = read(fd, cp, len);
978 		if (amount < 0) {
979 			_kvm_syserr(kd, kd->program, "error reading %s",
980 			    procfile);
981 			break;
982 		}
983 		if (amount == 0) {
984 			_kvm_err(kd, kd->program, "EOF reading %s", procfile);
985 			break;
986 		}
987 		cp += amount;
988 		uva += amount;
989 		len -= amount;
990 	}
991 
992 	close(fd);
993 	return ((ssize_t)(cp - buf));
994 }
995