xref: /freebsd/lib/libkvm/kvm_proc.c (revision 6af83ee0d2941d18880b6aaa2b4facd1d30c6106)
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  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *	This product includes software developed by the University of
20  *	California, Berkeley and its contributors.
21  * 4. Neither the name of the University nor the names of its contributors
22  *    may be used to endorse or promote products derived from this software
23  *    without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  */
37 
38 #if 0
39 #if defined(LIBC_SCCS) && !defined(lint)
40 static char sccsid[] = "@(#)kvm_proc.c	8.3 (Berkeley) 9/23/93";
41 #endif /* LIBC_SCCS and not lint */
42 #endif
43 
44 #include <sys/cdefs.h>
45 __FBSDID("$FreeBSD$");
46 
47 /*
48  * Proc traversal interface for kvm.  ps and w are (probably) the exclusive
49  * users of this code, so we've factored it out into a separate module.
50  * Thus, we keep this grunge out of the other kvm applications (i.e.,
51  * most other applications are interested only in open/close/read/nlist).
52  */
53 
54 #include <sys/param.h>
55 #define _WANT_UCRED	/* make ucred.h give us 'struct ucred' */
56 #include <sys/ucred.h>
57 #include <sys/user.h>
58 #include <sys/proc.h>
59 #include <sys/exec.h>
60 #include <sys/stat.h>
61 #include <sys/sysent.h>
62 #include <sys/ioctl.h>
63 #include <sys/tty.h>
64 #include <sys/file.h>
65 #include <sys/conf.h>
66 #include <stdio.h>
67 #include <stdlib.h>
68 #include <unistd.h>
69 #include <nlist.h>
70 #include <kvm.h>
71 
72 #include <vm/vm.h>
73 #include <vm/vm_param.h>
74 
75 #include <sys/sysctl.h>
76 
77 #include <limits.h>
78 #include <memory.h>
79 #include <paths.h>
80 
81 #include "kvm_private.h"
82 
83 #define KREAD(kd, addr, obj) \
84 	(kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj))
85 
86 /*
87  * Read proc's from memory file into buffer bp, which has space to hold
88  * at most maxcnt procs.
89  */
90 static int
91 kvm_proclist(kd, what, arg, p, bp, maxcnt)
92 	kvm_t *kd;
93 	int what, arg;
94 	struct proc *p;
95 	struct kinfo_proc *bp;
96 	int maxcnt;
97 {
98 	int cnt = 0;
99 	struct kinfo_proc kinfo_proc, *kp;
100 	struct pgrp pgrp;
101 	struct session sess;
102 	struct cdev t_cdev;
103 	struct tty tty;
104 	struct vmspace vmspace;
105 	struct sigacts sigacts;
106 	struct pstats pstats;
107 	struct ucred ucred;
108 	struct thread mtd;
109 	/*struct kse mke;*/
110 	struct ksegrp mkg;
111 	struct proc proc;
112 	struct proc pproc;
113 	struct timeval tv;
114 	struct sysentvec sysent;
115 	char svname[KI_EMULNAMELEN];
116 
117 	kp = &kinfo_proc;
118 	kp->ki_structsize = sizeof(kinfo_proc);
119 	for (; cnt < maxcnt && p != NULL; p = LIST_NEXT(&proc, p_list)) {
120 		memset(kp, 0, sizeof *kp);
121 		if (KREAD(kd, (u_long)p, &proc)) {
122 			_kvm_err(kd, kd->program, "can't read proc at %x", p);
123 			return (-1);
124 		}
125 		if (proc.p_state != PRS_ZOMBIE) {
126 			if (KREAD(kd, (u_long)TAILQ_FIRST(&proc.p_threads),
127 			    &mtd)) {
128 				_kvm_err(kd, kd->program,
129 				    "can't read thread at %x",
130 				    TAILQ_FIRST(&proc.p_threads));
131 				return (-1);
132 			}
133 			if ((proc.p_flag & P_SA) == 0) {
134 				if (KREAD(kd,
135 				    (u_long)TAILQ_FIRST(&proc.p_ksegrps),
136 				    &mkg)) {
137 					_kvm_err(kd, kd->program,
138 					    "can't read ksegrp at %x",
139 					    TAILQ_FIRST(&proc.p_ksegrps));
140 					return (-1);
141 				}
142 #if 0
143 				if (KREAD(kd,
144 				    (u_long)TAILQ_FIRST(&mkg.kg_kseq), &mke)) {
145 					_kvm_err(kd, kd->program,
146 					    "can't read kse at %x",
147 					    TAILQ_FIRST(&mkg.kg_kseq));
148 					return (-1);
149 				}
150 #endif
151 			}
152 		}
153 		if (KREAD(kd, (u_long)proc.p_ucred, &ucred) == 0) {
154 			kp->ki_ruid = ucred.cr_ruid;
155 			kp->ki_svuid = ucred.cr_svuid;
156 			kp->ki_rgid = ucred.cr_rgid;
157 			kp->ki_svgid = ucred.cr_svgid;
158 			kp->ki_ngroups = ucred.cr_ngroups;
159 			bcopy(ucred.cr_groups, kp->ki_groups,
160 			    NGROUPS * sizeof(gid_t));
161 			kp->ki_uid = ucred.cr_uid;
162 		}
163 
164 		switch(what & ~KERN_PROC_INC_THREAD) {
165 
166 		case KERN_PROC_GID:
167 			if (kp->ki_groups[0] != (gid_t)arg)
168 				continue;
169 			break;
170 
171 		case KERN_PROC_PID:
172 			if (proc.p_pid != (pid_t)arg)
173 				continue;
174 			break;
175 
176 		case KERN_PROC_RGID:
177 			if (kp->ki_rgid != (gid_t)arg)
178 				continue;
179 			break;
180 
181 		case KERN_PROC_UID:
182 			if (kp->ki_uid != (uid_t)arg)
183 				continue;
184 			break;
185 
186 		case KERN_PROC_RUID:
187 			if (kp->ki_ruid != (uid_t)arg)
188 				continue;
189 			break;
190 		}
191 		/*
192 		 * We're going to add another proc to the set.  If this
193 		 * will overflow the buffer, assume the reason is because
194 		 * nprocs (or the proc list) is corrupt and declare an error.
195 		 */
196 		if (cnt >= maxcnt) {
197 			_kvm_err(kd, kd->program, "nprocs corrupt");
198 			return (-1);
199 		}
200 		/*
201 		 * gather kinfo_proc
202 		 */
203 		kp->ki_paddr = p;
204 		kp->ki_addr = 0;	/* XXX uarea */
205 		/* kp->ki_kstack = proc.p_thread.td_kstack; XXXKSE */
206 		kp->ki_args = proc.p_args;
207 		kp->ki_tracep = proc.p_tracevp;
208 		kp->ki_textvp = proc.p_textvp;
209 		kp->ki_fd = proc.p_fd;
210 		kp->ki_vmspace = proc.p_vmspace;
211 		if (proc.p_sigacts != NULL) {
212 			if (KREAD(kd, (u_long)proc.p_sigacts, &sigacts)) {
213 				_kvm_err(kd, kd->program,
214 				    "can't read sigacts at %x", proc.p_sigacts);
215 				return (-1);
216 			}
217 			kp->ki_sigignore = sigacts.ps_sigignore;
218 			kp->ki_sigcatch = sigacts.ps_sigcatch;
219 		}
220 		if ((proc.p_sflag & PS_INMEM) && proc.p_stats != NULL) {
221 			if (KREAD(kd, (u_long)proc.p_stats, &pstats)) {
222 				_kvm_err(kd, kd->program,
223 				    "can't read stats at %x", proc.p_stats);
224 				return (-1);
225 			}
226 			kp->ki_start = pstats.p_start;
227 
228 			/*
229 			 * XXX: The times here are probably zero and need
230 			 * to be calculated from the raw data in p_rux and
231 			 * p_crux.
232 			 */
233 			kp->ki_rusage = pstats.p_ru;
234 			kp->ki_childstime = pstats.p_cru.ru_stime;
235 			kp->ki_childutime = pstats.p_cru.ru_utime;
236 			/* Some callers want child-times in a single value */
237 			timeradd(&kp->ki_childstime, &kp->ki_childutime,
238 			    &kp->ki_childtime);
239 		}
240 		if (proc.p_oppid)
241 			kp->ki_ppid = proc.p_oppid;
242 		else if (proc.p_pptr) {
243 			if (KREAD(kd, (u_long)proc.p_pptr, &pproc)) {
244 				_kvm_err(kd, kd->program,
245 				    "can't read pproc at %x", proc.p_pptr);
246 				return (-1);
247 			}
248 			kp->ki_ppid = pproc.p_pid;
249 		} else
250 			kp->ki_ppid = 0;
251 		if (proc.p_pgrp == NULL)
252 			goto nopgrp;
253 		if (KREAD(kd, (u_long)proc.p_pgrp, &pgrp)) {
254 			_kvm_err(kd, kd->program, "can't read pgrp at %x",
255 				 proc.p_pgrp);
256 			return (-1);
257 		}
258 		kp->ki_pgid = pgrp.pg_id;
259 		kp->ki_jobc = pgrp.pg_jobc;
260 		if (KREAD(kd, (u_long)pgrp.pg_session, &sess)) {
261 			_kvm_err(kd, kd->program, "can't read session at %x",
262 				pgrp.pg_session);
263 			return (-1);
264 		}
265 		kp->ki_sid = sess.s_sid;
266 		(void)memcpy(kp->ki_login, sess.s_login,
267 						sizeof(kp->ki_login));
268 		kp->ki_kiflag = sess.s_ttyvp ? KI_CTTY : 0;
269 		if (sess.s_leader == p)
270 			kp->ki_kiflag |= KI_SLEADER;
271 		if ((proc.p_flag & P_CONTROLT) && sess.s_ttyp != NULL) {
272 			if (KREAD(kd, (u_long)sess.s_ttyp, &tty)) {
273 				_kvm_err(kd, kd->program,
274 					 "can't read tty at %x", sess.s_ttyp);
275 				return (-1);
276 			}
277 			if (tty.t_dev != NULL) {
278 				if (KREAD(kd, (u_long)tty.t_dev, &t_cdev)) {
279 					_kvm_err(kd, kd->program,
280 						 "can't read cdev at %x",
281 						tty.t_dev);
282 					return (-1);
283 				}
284 				kp->ki_tdev = t_cdev.si_udev;
285 			}
286 			if (tty.t_pgrp != NULL) {
287 				if (KREAD(kd, (u_long)tty.t_pgrp, &pgrp)) {
288 					_kvm_err(kd, kd->program,
289 						 "can't read tpgrp at %x",
290 						tty.t_pgrp);
291 					return (-1);
292 				}
293 				kp->ki_tpgid = pgrp.pg_id;
294 			} else
295 				kp->ki_tpgid = -1;
296 			if (tty.t_session != NULL) {
297 				if (KREAD(kd, (u_long)tty.t_session, &sess)) {
298 					_kvm_err(kd, kd->program,
299 					    "can't read session at %x",
300 					    tty.t_session);
301 					return (-1);
302 				}
303 				kp->ki_tsid = sess.s_sid;
304 			}
305 		} else {
306 nopgrp:
307 			kp->ki_tdev = NODEV;
308 		}
309 		if ((proc.p_state != PRS_ZOMBIE) && mtd.td_wmesg)
310 			(void)kvm_read(kd, (u_long)mtd.td_wmesg,
311 			    kp->ki_wmesg, WMESGLEN);
312 
313 		(void)kvm_read(kd, (u_long)proc.p_vmspace,
314 		    (char *)&vmspace, sizeof(vmspace));
315 		kp->ki_size = vmspace.vm_map.size;
316 		kp->ki_rssize = vmspace.vm_swrss; /* XXX */
317 		kp->ki_swrss = vmspace.vm_swrss;
318 		kp->ki_tsize = vmspace.vm_tsize;
319 		kp->ki_dsize = vmspace.vm_dsize;
320 		kp->ki_ssize = vmspace.vm_ssize;
321 
322 		switch (what & ~KERN_PROC_INC_THREAD) {
323 
324 		case KERN_PROC_PGRP:
325 			if (kp->ki_pgid != (pid_t)arg)
326 				continue;
327 			break;
328 
329 		case KERN_PROC_SESSION:
330 			if (kp->ki_sid != (pid_t)arg)
331 				continue;
332 			break;
333 
334 		case KERN_PROC_TTY:
335 			if ((proc.p_flag & P_CONTROLT) == 0 ||
336 			     kp->ki_tdev != (dev_t)arg)
337 				continue;
338 			break;
339 		}
340 		if (proc.p_comm[0] != 0)
341 			strlcpy(kp->ki_comm, proc.p_comm, MAXCOMLEN);
342 		(void)kvm_read(kd, (u_long)proc.p_sysent, (char *)&sysent,
343 		    sizeof(sysent));
344 		(void)kvm_read(kd, (u_long)sysent.sv_name, (char *)&svname,
345 		    sizeof(svname));
346 		if (svname[0] != 0)
347 			strlcpy(kp->ki_emul, svname, KI_EMULNAMELEN);
348 		if ((proc.p_state != PRS_ZOMBIE) &&
349 		    (mtd.td_blocked != 0)) {
350 			kp->ki_kiflag |= KI_LOCKBLOCK;
351 			if (mtd.td_lockname)
352 				(void)kvm_read(kd,
353 				    (u_long)mtd.td_lockname,
354 				    kp->ki_lockname, LOCKNAMELEN);
355 			kp->ki_lockname[LOCKNAMELEN] = 0;
356 		}
357 		bintime2timeval(&proc.p_rux.rux_runtime, &tv);
358 		kp->ki_runtime = (u_int64_t)tv.tv_sec * 1000000 + tv.tv_usec;
359 		kp->ki_pid = proc.p_pid;
360 		kp->ki_siglist = proc.p_siglist;
361 		SIGSETOR(kp->ki_siglist, mtd.td_siglist);
362 		kp->ki_sigmask = mtd.td_sigmask;
363 		kp->ki_xstat = proc.p_xstat;
364 		kp->ki_acflag = proc.p_acflag;
365 		kp->ki_lock = proc.p_lock;
366 		if (proc.p_state != PRS_ZOMBIE) {
367 			kp->ki_swtime = proc.p_swtime;
368 			kp->ki_flag = proc.p_flag;
369 			kp->ki_sflag = proc.p_sflag;
370 			kp->ki_nice = proc.p_nice;
371 			kp->ki_traceflag = proc.p_traceflag;
372 			if (proc.p_state == PRS_NORMAL) {
373 				if (TD_ON_RUNQ(&mtd) ||
374 				    TD_CAN_RUN(&mtd) ||
375 				    TD_IS_RUNNING(&mtd)) {
376 					kp->ki_stat = SRUN;
377 				} else if (mtd.td_state ==
378 				    TDS_INHIBITED) {
379 					if (P_SHOULDSTOP(&proc)) {
380 						kp->ki_stat = SSTOP;
381 					} else if (
382 					    TD_IS_SLEEPING(&mtd)) {
383 						kp->ki_stat = SSLEEP;
384 					} else if (TD_ON_LOCK(&mtd)) {
385 						kp->ki_stat = SLOCK;
386 					} else {
387 						kp->ki_stat = SWAIT;
388 					}
389 				}
390 			} else {
391 				kp->ki_stat = SIDL;
392 			}
393 			/* Stuff from the thread */
394 			kp->ki_pri.pri_level = mtd.td_priority;
395 			kp->ki_pri.pri_native = mtd.td_base_pri;
396 			kp->ki_lastcpu = mtd.td_lastcpu;
397 			kp->ki_wchan = mtd.td_wchan;
398 			kp->ki_oncpu = mtd.td_oncpu;
399 
400 			if (!(proc.p_flag & P_SA)) {
401 				/* stuff from the ksegrp */
402 				kp->ki_slptime = mkg.kg_slptime;
403 				kp->ki_pri.pri_class = mkg.kg_pri_class;
404 				kp->ki_pri.pri_user = mkg.kg_user_pri;
405 				kp->ki_estcpu = mkg.kg_estcpu;
406 
407 #if 0
408 				/* Stuff from the kse */
409 				kp->ki_pctcpu = mke.ke_pctcpu;
410 				kp->ki_rqindex = mke.ke_rqindex;
411 #else
412 				kp->ki_pctcpu = 0;
413 				kp->ki_rqindex = 0;
414 #endif
415 			} else {
416 				kp->ki_tdflags = -1;
417 				/* All the rest are 0 for now */
418 			}
419 		} else {
420 			kp->ki_stat = SZOMB;
421 		}
422 		bcopy(&kinfo_proc, bp, sizeof(kinfo_proc));
423 		++bp;
424 		++cnt;
425 	}
426 	return (cnt);
427 }
428 
429 /*
430  * Build proc info array by reading in proc list from a crash dump.
431  * Return number of procs read.  maxcnt is the max we will read.
432  */
433 static int
434 kvm_deadprocs(kd, what, arg, a_allproc, a_zombproc, maxcnt)
435 	kvm_t *kd;
436 	int what, arg;
437 	u_long a_allproc;
438 	u_long a_zombproc;
439 	int maxcnt;
440 {
441 	struct kinfo_proc *bp = kd->procbase;
442 	int acnt, zcnt;
443 	struct proc *p;
444 
445 	if (KREAD(kd, a_allproc, &p)) {
446 		_kvm_err(kd, kd->program, "cannot read allproc");
447 		return (-1);
448 	}
449 	acnt = kvm_proclist(kd, what, arg, p, bp, maxcnt);
450 	if (acnt < 0)
451 		return (acnt);
452 
453 	if (KREAD(kd, a_zombproc, &p)) {
454 		_kvm_err(kd, kd->program, "cannot read zombproc");
455 		return (-1);
456 	}
457 	zcnt = kvm_proclist(kd, what, arg, p, bp + acnt, maxcnt - acnt);
458 	if (zcnt < 0)
459 		zcnt = 0;
460 
461 	return (acnt + zcnt);
462 }
463 
464 struct kinfo_proc *
465 kvm_getprocs(kd, op, arg, cnt)
466 	kvm_t *kd;
467 	int op, arg;
468 	int *cnt;
469 {
470 	int mib[4], st, nprocs;
471 	size_t size;
472 	int temp_op;
473 
474 	if (kd->procbase != 0) {
475 		free((void *)kd->procbase);
476 		/*
477 		 * Clear this pointer in case this call fails.  Otherwise,
478 		 * kvm_close() will free it again.
479 		 */
480 		kd->procbase = 0;
481 	}
482 	if (ISALIVE(kd)) {
483 		size = 0;
484 		mib[0] = CTL_KERN;
485 		mib[1] = KERN_PROC;
486 		mib[2] = op;
487 		mib[3] = arg;
488 		temp_op = op & ~KERN_PROC_INC_THREAD;
489 		st = sysctl(mib,
490 		    temp_op == KERN_PROC_ALL || temp_op == KERN_PROC_PROC ?
491 		    3 : 4, NULL, &size, NULL, 0);
492 		if (st == -1) {
493 			_kvm_syserr(kd, kd->program, "kvm_getprocs");
494 			return (0);
495 		}
496 		/*
497 		 * We can't continue with a size of 0 because we pass
498 		 * it to realloc() (via _kvm_realloc()), and passing 0
499 		 * to realloc() results in undefined behavior.
500 		 */
501 		if (size == 0) {
502 			/*
503 			 * XXX: We should probably return an invalid,
504 			 * but non-NULL, pointer here so any client
505 			 * program trying to dereference it will
506 			 * crash.  However, _kvm_freeprocs() calls
507 			 * free() on kd->procbase if it isn't NULL,
508 			 * and free()'ing a junk pointer isn't good.
509 			 * Then again, _kvm_freeprocs() isn't used
510 			 * anywhere . . .
511 			 */
512 			kd->procbase = _kvm_malloc(kd, 1);
513 			goto liveout;
514 		}
515 		do {
516 			size += size / 10;
517 			kd->procbase = (struct kinfo_proc *)
518 			    _kvm_realloc(kd, kd->procbase, size);
519 			if (kd->procbase == 0)
520 				return (0);
521 			st = sysctl(mib, temp_op == KERN_PROC_ALL ||
522 			    temp_op == KERN_PROC_PROC ? 3 : 4,
523 			    kd->procbase, &size, NULL, 0);
524 		} while (st == -1 && errno == ENOMEM);
525 		if (st == -1) {
526 			_kvm_syserr(kd, kd->program, "kvm_getprocs");
527 			return (0);
528 		}
529 		/*
530 		 * We have to check the size again because sysctl()
531 		 * may "round up" oldlenp if oldp is NULL; hence it
532 		 * might've told us that there was data to get when
533 		 * there really isn't any.
534 		 */
535 		if (size > 0 &&
536 		    kd->procbase->ki_structsize != sizeof(struct kinfo_proc)) {
537 			_kvm_err(kd, kd->program,
538 			    "kinfo_proc size mismatch (expected %d, got %d)",
539 			    sizeof(struct kinfo_proc),
540 			    kd->procbase->ki_structsize);
541 			return (0);
542 		}
543 liveout:
544 		nprocs = size == 0 ? 0 : size / kd->procbase->ki_structsize;
545 	} else {
546 		struct nlist nl[4], *p;
547 
548 		nl[0].n_name = "_nprocs";
549 		nl[1].n_name = "_allproc";
550 		nl[2].n_name = "_zombproc";
551 		nl[3].n_name = 0;
552 
553 		if (kvm_nlist(kd, nl) != 0) {
554 			for (p = nl; p->n_type != 0; ++p)
555 				;
556 			_kvm_err(kd, kd->program,
557 				 "%s: no such symbol", p->n_name);
558 			return (0);
559 		}
560 		if (KREAD(kd, nl[0].n_value, &nprocs)) {
561 			_kvm_err(kd, kd->program, "can't read nprocs");
562 			return (0);
563 		}
564 		size = nprocs * sizeof(struct kinfo_proc);
565 		kd->procbase = (struct kinfo_proc *)_kvm_malloc(kd, size);
566 		if (kd->procbase == 0)
567 			return (0);
568 
569 		nprocs = kvm_deadprocs(kd, op, arg, nl[1].n_value,
570 				      nl[2].n_value, nprocs);
571 #ifdef notdef
572 		size = nprocs * sizeof(struct kinfo_proc);
573 		(void)realloc(kd->procbase, size);
574 #endif
575 	}
576 	*cnt = nprocs;
577 	return (kd->procbase);
578 }
579 
580 void
581 _kvm_freeprocs(kd)
582 	kvm_t *kd;
583 {
584 	if (kd->procbase) {
585 		free(kd->procbase);
586 		kd->procbase = 0;
587 	}
588 }
589 
590 void *
591 _kvm_realloc(kd, p, n)
592 	kvm_t *kd;
593 	void *p;
594 	size_t n;
595 {
596 	void *np = (void *)realloc(p, n);
597 
598 	if (np == 0) {
599 		free(p);
600 		_kvm_err(kd, kd->program, "out of memory");
601 	}
602 	return (np);
603 }
604 
605 #ifndef MAX
606 #define MAX(a, b) ((a) > (b) ? (a) : (b))
607 #endif
608 
609 /*
610  * Read in an argument vector from the user address space of process kp.
611  * addr if the user-space base address of narg null-terminated contiguous
612  * strings.  This is used to read in both the command arguments and
613  * environment strings.  Read at most maxcnt characters of strings.
614  */
615 static char **
616 kvm_argv(kd, kp, addr, narg, maxcnt)
617 	kvm_t *kd;
618 	struct kinfo_proc *kp;
619 	u_long addr;
620 	int narg;
621 	int maxcnt;
622 {
623 	char *np, *cp, *ep, *ap;
624 	u_long oaddr = -1;
625 	int len, cc;
626 	char **argv;
627 
628 	/*
629 	 * Check that there aren't an unreasonable number of agruments,
630 	 * and that the address is in user space.
631 	 */
632 	if (narg > 512 || addr < VM_MIN_ADDRESS || addr >= VM_MAXUSER_ADDRESS)
633 		return (0);
634 
635 	/*
636 	 * kd->argv : work space for fetching the strings from the target
637 	 *            process's space, and is converted for returning to caller
638 	 */
639 	if (kd->argv == 0) {
640 		/*
641 		 * Try to avoid reallocs.
642 		 */
643 		kd->argc = MAX(narg + 1, 32);
644 		kd->argv = (char **)_kvm_malloc(kd, kd->argc *
645 						sizeof(*kd->argv));
646 		if (kd->argv == 0)
647 			return (0);
648 	} else if (narg + 1 > kd->argc) {
649 		kd->argc = MAX(2 * kd->argc, narg + 1);
650 		kd->argv = (char **)_kvm_realloc(kd, kd->argv, kd->argc *
651 						sizeof(*kd->argv));
652 		if (kd->argv == 0)
653 			return (0);
654 	}
655 	/*
656 	 * kd->argspc : returned to user, this is where the kd->argv
657 	 *              arrays are left pointing to the collected strings.
658 	 */
659 	if (kd->argspc == 0) {
660 		kd->argspc = (char *)_kvm_malloc(kd, PAGE_SIZE);
661 		if (kd->argspc == 0)
662 			return (0);
663 		kd->arglen = PAGE_SIZE;
664 	}
665 	/*
666 	 * kd->argbuf : used to pull in pages from the target process.
667 	 *              the strings are copied out of here.
668 	 */
669 	if (kd->argbuf == 0) {
670 		kd->argbuf = (char *)_kvm_malloc(kd, PAGE_SIZE);
671 		if (kd->argbuf == 0)
672 			return (0);
673 	}
674 
675 	/* Pull in the target process'es argv vector */
676 	cc = sizeof(char *) * narg;
677 	if (kvm_uread(kd, kp, addr, (char *)kd->argv, cc) != cc)
678 		return (0);
679 	/*
680 	 * ap : saved start address of string we're working on in kd->argspc
681 	 * np : pointer to next place to write in kd->argspc
682 	 * len: length of data in kd->argspc
683 	 * argv: pointer to the argv vector that we are hunting around the
684 	 *       target process space for, and converting to addresses in
685 	 *       our address space (kd->argspc).
686 	 */
687 	ap = np = kd->argspc;
688 	argv = kd->argv;
689 	len = 0;
690 	/*
691 	 * Loop over pages, filling in the argument vector.
692 	 * Note that the argv strings could be pointing *anywhere* in
693 	 * the user address space and are no longer contiguous.
694 	 * Note that *argv is modified when we are going to fetch a string
695 	 * that crosses a page boundary.  We copy the next part of the string
696 	 * into to "np" and eventually convert the pointer.
697 	 */
698 	while (argv < kd->argv + narg && *argv != 0) {
699 
700 		/* get the address that the current argv string is on */
701 		addr = (u_long)*argv & ~(PAGE_SIZE - 1);
702 
703 		/* is it the same page as the last one? */
704 		if (addr != oaddr) {
705 			if (kvm_uread(kd, kp, addr, kd->argbuf, PAGE_SIZE) !=
706 			    PAGE_SIZE)
707 				return (0);
708 			oaddr = addr;
709 		}
710 
711 		/* offset within the page... kd->argbuf */
712 		addr = (u_long)*argv & (PAGE_SIZE - 1);
713 
714 		/* cp = start of string, cc = count of chars in this chunk */
715 		cp = kd->argbuf + addr;
716 		cc = PAGE_SIZE - addr;
717 
718 		/* dont get more than asked for by user process */
719 		if (maxcnt > 0 && cc > maxcnt - len)
720 			cc = maxcnt - len;
721 
722 		/* pointer to end of string if we found it in this page */
723 		ep = memchr(cp, '\0', cc);
724 		if (ep != 0)
725 			cc = ep - cp + 1;
726 		/*
727 		 * at this point, cc is the count of the chars that we are
728 		 * going to retrieve this time. we may or may not have found
729 		 * the end of it.  (ep points to the null if the end is known)
730 		 */
731 
732 		/* will we exceed the malloc/realloced buffer? */
733 		if (len + cc > kd->arglen) {
734 			int off;
735 			char **pp;
736 			char *op = kd->argspc;
737 
738 			kd->arglen *= 2;
739 			kd->argspc = (char *)_kvm_realloc(kd, kd->argspc,
740 							  kd->arglen);
741 			if (kd->argspc == 0)
742 				return (0);
743 			/*
744 			 * Adjust argv pointers in case realloc moved
745 			 * the string space.
746 			 */
747 			off = kd->argspc - op;
748 			for (pp = kd->argv; pp < argv; pp++)
749 				*pp += off;
750 			ap += off;
751 			np += off;
752 		}
753 		/* np = where to put the next part of the string in kd->argspc*/
754 		/* np is kinda redundant.. could use "kd->argspc + len" */
755 		memcpy(np, cp, cc);
756 		np += cc;	/* inc counters */
757 		len += cc;
758 
759 		/*
760 		 * if end of string found, set the *argv pointer to the
761 		 * saved beginning of string, and advance. argv points to
762 		 * somewhere in kd->argv..  This is initially relative
763 		 * to the target process, but when we close it off, we set
764 		 * it to point in our address space.
765 		 */
766 		if (ep != 0) {
767 			*argv++ = ap;
768 			ap = np;
769 		} else {
770 			/* update the address relative to the target process */
771 			*argv += cc;
772 		}
773 
774 		if (maxcnt > 0 && len >= maxcnt) {
775 			/*
776 			 * We're stopping prematurely.  Terminate the
777 			 * current string.
778 			 */
779 			if (ep == 0) {
780 				*np = '\0';
781 				*argv++ = ap;
782 			}
783 			break;
784 		}
785 	}
786 	/* Make sure argv is terminated. */
787 	*argv = 0;
788 	return (kd->argv);
789 }
790 
791 static void
792 ps_str_a(p, addr, n)
793 	struct ps_strings *p;
794 	u_long *addr;
795 	int *n;
796 {
797 	*addr = (u_long)p->ps_argvstr;
798 	*n = p->ps_nargvstr;
799 }
800 
801 static void
802 ps_str_e(p, addr, n)
803 	struct ps_strings *p;
804 	u_long *addr;
805 	int *n;
806 {
807 	*addr = (u_long)p->ps_envstr;
808 	*n = p->ps_nenvstr;
809 }
810 
811 /*
812  * Determine if the proc indicated by p is still active.
813  * This test is not 100% foolproof in theory, but chances of
814  * being wrong are very low.
815  */
816 static int
817 proc_verify(curkp)
818 	struct kinfo_proc *curkp;
819 {
820 	struct kinfo_proc newkp;
821 	int mib[4];
822 	size_t len;
823 
824 	mib[0] = CTL_KERN;
825 	mib[1] = KERN_PROC;
826 	mib[2] = KERN_PROC_PID;
827 	mib[3] = curkp->ki_pid;
828 	len = sizeof(newkp);
829 	if (sysctl(mib, 4, &newkp, &len, NULL, 0) == -1)
830 		return (0);
831 	return (curkp->ki_pid == newkp.ki_pid &&
832 	    (newkp.ki_stat != SZOMB || curkp->ki_stat == SZOMB));
833 }
834 
835 static char **
836 kvm_doargv(kd, kp, nchr, info)
837 	kvm_t *kd;
838 	struct kinfo_proc *kp;
839 	int nchr;
840 	void (*info)(struct ps_strings *, u_long *, int *);
841 {
842 	char **ap;
843 	u_long addr;
844 	int cnt;
845 	static struct ps_strings arginfo;
846 	static u_long ps_strings;
847 	size_t len;
848 
849 	if (ps_strings == 0) {
850 		len = sizeof(ps_strings);
851 		if (sysctlbyname("kern.ps_strings", &ps_strings, &len, NULL,
852 		    0) == -1)
853 			ps_strings = PS_STRINGS;
854 	}
855 
856 	/*
857 	 * Pointers are stored at the top of the user stack.
858 	 */
859 	if (kp->ki_stat == SZOMB ||
860 	    kvm_uread(kd, kp, ps_strings, (char *)&arginfo,
861 		      sizeof(arginfo)) != sizeof(arginfo))
862 		return (0);
863 
864 	(*info)(&arginfo, &addr, &cnt);
865 	if (cnt == 0)
866 		return (0);
867 	ap = kvm_argv(kd, kp, addr, cnt, nchr);
868 	/*
869 	 * For live kernels, make sure this process didn't go away.
870 	 */
871 	if (ap != 0 && ISALIVE(kd) && !proc_verify(kp))
872 		ap = 0;
873 	return (ap);
874 }
875 
876 /*
877  * Get the command args.  This code is now machine independent.
878  */
879 char **
880 kvm_getargv(kd, kp, nchr)
881 	kvm_t *kd;
882 	const struct kinfo_proc *kp;
883 	int nchr;
884 {
885 	int oid[4];
886 	int i;
887 	size_t bufsz;
888 	static unsigned long buflen;
889 	static char *buf, *p;
890 	static char **bufp;
891 	static int argc;
892 
893 	if (!ISALIVE(kd)) {
894 		_kvm_err(kd, kd->program,
895 		    "cannot read user space from dead kernel");
896 		return (0);
897 	}
898 
899 	if (!buflen) {
900 		bufsz = sizeof(buflen);
901 		i = sysctlbyname("kern.ps_arg_cache_limit",
902 		    &buflen, &bufsz, NULL, 0);
903 		if (i == -1) {
904 			buflen = 0;
905 		} else {
906 			buf = malloc(buflen);
907 			if (buf == NULL)
908 				buflen = 0;
909 			argc = 32;
910 			bufp = malloc(sizeof(char *) * argc);
911 		}
912 	}
913 	if (buf != NULL) {
914 		oid[0] = CTL_KERN;
915 		oid[1] = KERN_PROC;
916 		oid[2] = KERN_PROC_ARGS;
917 		oid[3] = kp->ki_pid;
918 		bufsz = buflen;
919 		i = sysctl(oid, 4, buf, &bufsz, 0, 0);
920 		if (i == 0 && bufsz > 0) {
921 			i = 0;
922 			p = buf;
923 			do {
924 				bufp[i++] = p;
925 				p += strlen(p) + 1;
926 				if (i >= argc) {
927 					argc += argc;
928 					bufp = realloc(bufp,
929 					    sizeof(char *) * argc);
930 				}
931 			} while (p < buf + bufsz);
932 			bufp[i++] = 0;
933 			return (bufp);
934 		}
935 	}
936 	if (kp->ki_flag & P_SYSTEM)
937 		return (NULL);
938 	return (kvm_doargv(kd, kp, nchr, ps_str_a));
939 }
940 
941 char **
942 kvm_getenvv(kd, kp, nchr)
943 	kvm_t *kd;
944 	const struct kinfo_proc *kp;
945 	int nchr;
946 {
947 	return (kvm_doargv(kd, kp, nchr, ps_str_e));
948 }
949 
950 /*
951  * Read from user space.  The user context is given by p.
952  */
953 ssize_t
954 kvm_uread(kd, kp, uva, buf, len)
955 	kvm_t *kd;
956 	struct kinfo_proc *kp;
957 	u_long uva;
958 	char *buf;
959 	size_t len;
960 {
961 	char *cp;
962 	char procfile[MAXPATHLEN];
963 	ssize_t amount;
964 	int fd;
965 
966 	if (!ISALIVE(kd)) {
967 		_kvm_err(kd, kd->program,
968 		    "cannot read user space from dead kernel");
969 		return (0);
970 	}
971 
972 	sprintf(procfile, "/proc/%d/mem", kp->ki_pid);
973 	fd = open(procfile, O_RDONLY, 0);
974 	if (fd < 0) {
975 		_kvm_err(kd, kd->program, "cannot open %s", procfile);
976 		return (0);
977 	}
978 
979 	cp = buf;
980 	while (len > 0) {
981 		errno = 0;
982 		if (lseek(fd, (off_t)uva, 0) == -1 && errno != 0) {
983 			_kvm_err(kd, kd->program, "invalid address (%x) in %s",
984 			    uva, procfile);
985 			break;
986 		}
987 		amount = read(fd, cp, len);
988 		if (amount < 0) {
989 			_kvm_syserr(kd, kd->program, "error reading %s",
990 			    procfile);
991 			break;
992 		}
993 		if (amount == 0) {
994 			_kvm_err(kd, kd->program, "EOF reading %s", procfile);
995 			break;
996 		}
997 		cp += amount;
998 		uva += amount;
999 		len -= amount;
1000 	}
1001 
1002 	close(fd);
1003 	return ((ssize_t)(cp - buf));
1004 }
1005