xref: /netbsd-src/sys/kern/kern_proc.c (revision e0ea3921ea68e51b93ffc215f08ae1647c8e1796)
1 /*	$NetBSD: kern_proc.c,v 1.217 2018/09/04 16:03:56 maxv Exp $	*/
2 
3 /*-
4  * Copyright (c) 1999, 2006, 2007, 2008 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9  * NASA Ames Research Center, and by Andrew Doran.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 /*
34  * Copyright (c) 1982, 1986, 1989, 1991, 1993
35  *	The Regents of the University of California.  All rights reserved.
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  * 3. Neither the name of the University nor the names of its contributors
46  *    may be used to endorse or promote products derived from this software
47  *    without specific prior written permission.
48  *
49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59  * SUCH DAMAGE.
60  *
61  *	@(#)kern_proc.c	8.7 (Berkeley) 2/14/95
62  */
63 
64 #include <sys/cdefs.h>
65 __KERNEL_RCSID(0, "$NetBSD: kern_proc.c,v 1.217 2018/09/04 16:03:56 maxv Exp $");
66 
67 #ifdef _KERNEL_OPT
68 #include "opt_kstack.h"
69 #include "opt_maxuprc.h"
70 #include "opt_dtrace.h"
71 #include "opt_compat_netbsd32.h"
72 #endif
73 
74 #if defined(__HAVE_COMPAT_NETBSD32) && !defined(COMPAT_NETBSD32) \
75     && !defined(_RUMPKERNEL)
76 #define COMPAT_NETBSD32
77 #endif
78 
79 #include <sys/param.h>
80 #include <sys/systm.h>
81 #include <sys/kernel.h>
82 #include <sys/proc.h>
83 #include <sys/resourcevar.h>
84 #include <sys/buf.h>
85 #include <sys/acct.h>
86 #include <sys/wait.h>
87 #include <sys/file.h>
88 #include <ufs/ufs/quota.h>
89 #include <sys/uio.h>
90 #include <sys/pool.h>
91 #include <sys/pset.h>
92 #include <sys/mbuf.h>
93 #include <sys/ioctl.h>
94 #include <sys/tty.h>
95 #include <sys/signalvar.h>
96 #include <sys/ras.h>
97 #include <sys/filedesc.h>
98 #include <sys/syscall_stats.h>
99 #include <sys/kauth.h>
100 #include <sys/sleepq.h>
101 #include <sys/atomic.h>
102 #include <sys/kmem.h>
103 #include <sys/namei.h>
104 #include <sys/dtrace_bsd.h>
105 #include <sys/sysctl.h>
106 #include <sys/exec.h>
107 #include <sys/cpu.h>
108 
109 #include <uvm/uvm_extern.h>
110 #include <uvm/uvm.h>
111 
112 #ifdef COMPAT_NETBSD32
113 #include <compat/netbsd32/netbsd32.h>
114 #endif
115 
116 /*
117  * Process lists.
118  */
119 
120 struct proclist		allproc		__cacheline_aligned;
121 struct proclist		zombproc	__cacheline_aligned;
122 
123 kmutex_t *		proc_lock	__cacheline_aligned;
124 
125 /*
126  * pid to proc lookup is done by indexing the pid_table array.
127  * Since pid numbers are only allocated when an empty slot
128  * has been found, there is no need to search any lists ever.
129  * (an orphaned pgrp will lock the slot, a session will lock
130  * the pgrp with the same number.)
131  * If the table is too small it is reallocated with twice the
132  * previous size and the entries 'unzipped' into the two halves.
133  * A linked list of free entries is passed through the pt_proc
134  * field of 'free' items - set odd to be an invalid ptr.
135  */
136 
137 struct pid_table {
138 	struct proc	*pt_proc;
139 	struct pgrp	*pt_pgrp;
140 	pid_t		pt_pid;
141 };
142 #if 1	/* strongly typed cast - should be a noop */
143 static inline uint p2u(struct proc *p) { return (uint)(uintptr_t)p; }
144 #else
145 #define p2u(p) ((uint)p)
146 #endif
147 #define P_VALID(p) (!(p2u(p) & 1))
148 #define P_NEXT(p) (p2u(p) >> 1)
149 #define P_FREE(pid) ((struct proc *)(uintptr_t)((pid) << 1 | 1))
150 
151 /*
152  * Table of process IDs (PIDs).
153  */
154 static struct pid_table *pid_table	__read_mostly;
155 
156 #define	INITIAL_PID_TABLE_SIZE		(1 << 5)
157 
158 /* Table mask, threshold for growing and number of allocated PIDs. */
159 static u_int		pid_tbl_mask	__read_mostly;
160 static u_int		pid_alloc_lim	__read_mostly;
161 static u_int		pid_alloc_cnt	__cacheline_aligned;
162 
163 /* Next free, last free and maximum PIDs. */
164 static u_int		next_free_pt	__cacheline_aligned;
165 static u_int		last_free_pt	__cacheline_aligned;
166 static pid_t		pid_max		__read_mostly;
167 
168 /* Components of the first process -- never freed. */
169 
170 extern struct emul emul_netbsd;	/* defined in kern_exec.c */
171 
172 struct session session0 = {
173 	.s_count = 1,
174 	.s_sid = 0,
175 };
176 struct pgrp pgrp0 = {
177 	.pg_members = LIST_HEAD_INITIALIZER(&pgrp0.pg_members),
178 	.pg_session = &session0,
179 };
180 filedesc_t filedesc0;
181 struct cwdinfo cwdi0 = {
182 	.cwdi_cmask = CMASK,
183 	.cwdi_refcnt = 1,
184 };
185 struct plimit limit0;
186 struct pstats pstat0;
187 struct vmspace vmspace0;
188 struct sigacts sigacts0;
189 struct proc proc0 = {
190 	.p_lwps = LIST_HEAD_INITIALIZER(&proc0.p_lwps),
191 	.p_sigwaiters = LIST_HEAD_INITIALIZER(&proc0.p_sigwaiters),
192 	.p_nlwps = 1,
193 	.p_nrlwps = 1,
194 	.p_nlwpid = 1,		/* must match lwp0.l_lid */
195 	.p_pgrp = &pgrp0,
196 	.p_comm = "system",
197 	/*
198 	 * Set P_NOCLDWAIT so that kernel threads are reparented to init(8)
199 	 * when they exit.  init(8) can easily wait them out for us.
200 	 */
201 	.p_flag = PK_SYSTEM | PK_NOCLDWAIT,
202 	.p_stat = SACTIVE,
203 	.p_nice = NZERO,
204 	.p_emul = &emul_netbsd,
205 	.p_cwdi = &cwdi0,
206 	.p_limit = &limit0,
207 	.p_fd = &filedesc0,
208 	.p_vmspace = &vmspace0,
209 	.p_stats = &pstat0,
210 	.p_sigacts = &sigacts0,
211 #ifdef PROC0_MD_INITIALIZERS
212 	PROC0_MD_INITIALIZERS
213 #endif
214 };
215 kauth_cred_t cred0;
216 
217 static const int	nofile	= NOFILE;
218 static const int	maxuprc	= MAXUPRC;
219 
220 static int sysctl_doeproc(SYSCTLFN_PROTO);
221 static int sysctl_kern_proc_args(SYSCTLFN_PROTO);
222 
223 /*
224  * The process list descriptors, used during pid allocation and
225  * by sysctl.  No locking on this data structure is needed since
226  * it is completely static.
227  */
228 const struct proclist_desc proclists[] = {
229 	{ &allproc	},
230 	{ &zombproc	},
231 	{ NULL		},
232 };
233 
234 static struct pgrp *	pg_remove(pid_t);
235 static void		pg_delete(pid_t);
236 static void		orphanpg(struct pgrp *);
237 
238 static specificdata_domain_t proc_specificdata_domain;
239 
240 static pool_cache_t proc_cache;
241 
242 static kauth_listener_t proc_listener;
243 
244 static int fill_pathname(struct lwp *, pid_t, void *, size_t *);
245 
246 static int
247 proc_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie,
248     void *arg0, void *arg1, void *arg2, void *arg3)
249 {
250 	struct proc *p;
251 	int result;
252 
253 	result = KAUTH_RESULT_DEFER;
254 	p = arg0;
255 
256 	switch (action) {
257 	case KAUTH_PROCESS_CANSEE: {
258 		enum kauth_process_req req;
259 
260 		req = (enum kauth_process_req)arg1;
261 
262 		switch (req) {
263 		case KAUTH_REQ_PROCESS_CANSEE_ARGS:
264 		case KAUTH_REQ_PROCESS_CANSEE_ENTRY:
265 		case KAUTH_REQ_PROCESS_CANSEE_OPENFILES:
266 		case KAUTH_REQ_PROCESS_CANSEE_EPROC:
267 			result = KAUTH_RESULT_ALLOW;
268 			break;
269 
270 		case KAUTH_REQ_PROCESS_CANSEE_ENV:
271 			if (kauth_cred_getuid(cred) !=
272 			    kauth_cred_getuid(p->p_cred) ||
273 			    kauth_cred_getuid(cred) !=
274 			    kauth_cred_getsvuid(p->p_cred))
275 				break;
276 
277 			result = KAUTH_RESULT_ALLOW;
278 
279 			break;
280 
281 		case KAUTH_REQ_PROCESS_CANSEE_KPTR:
282 		default:
283 			break;
284 		}
285 
286 		break;
287 		}
288 
289 	case KAUTH_PROCESS_FORK: {
290 		int lnprocs = (int)(unsigned long)arg2;
291 
292 		/*
293 		 * Don't allow a nonprivileged user to use the last few
294 		 * processes. The variable lnprocs is the current number of
295 		 * processes, maxproc is the limit.
296 		 */
297 		if (__predict_false((lnprocs >= maxproc - 5)))
298 			break;
299 
300 		result = KAUTH_RESULT_ALLOW;
301 
302 		break;
303 		}
304 
305 	case KAUTH_PROCESS_CORENAME:
306 	case KAUTH_PROCESS_STOPFLAG:
307 		if (proc_uidmatch(cred, p->p_cred) == 0)
308 			result = KAUTH_RESULT_ALLOW;
309 
310 		break;
311 
312 	default:
313 		break;
314 	}
315 
316 	return result;
317 }
318 
319 /*
320  * Initialize global process hashing structures.
321  */
322 void
323 procinit(void)
324 {
325 	const struct proclist_desc *pd;
326 	u_int i;
327 #define	LINK_EMPTY ((PID_MAX + INITIAL_PID_TABLE_SIZE) & ~(INITIAL_PID_TABLE_SIZE - 1))
328 
329 	for (pd = proclists; pd->pd_list != NULL; pd++)
330 		LIST_INIT(pd->pd_list);
331 
332 	proc_lock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NONE);
333 	pid_table = kmem_alloc(INITIAL_PID_TABLE_SIZE
334 	    * sizeof(struct pid_table), KM_SLEEP);
335 	pid_tbl_mask = INITIAL_PID_TABLE_SIZE - 1;
336 	pid_max = PID_MAX;
337 
338 	/* Set free list running through table...
339 	   Preset 'use count' above PID_MAX so we allocate pid 1 next. */
340 	for (i = 0; i <= pid_tbl_mask; i++) {
341 		pid_table[i].pt_proc = P_FREE(LINK_EMPTY + i + 1);
342 		pid_table[i].pt_pgrp = 0;
343 		pid_table[i].pt_pid = 0;
344 	}
345 	/* slot 0 is just grabbed */
346 	next_free_pt = 1;
347 	/* Need to fix last entry. */
348 	last_free_pt = pid_tbl_mask;
349 	pid_table[last_free_pt].pt_proc = P_FREE(LINK_EMPTY);
350 	/* point at which we grow table - to avoid reusing pids too often */
351 	pid_alloc_lim = pid_tbl_mask - 1;
352 #undef LINK_EMPTY
353 
354 	proc_specificdata_domain = specificdata_domain_create();
355 	KASSERT(proc_specificdata_domain != NULL);
356 
357 	proc_cache = pool_cache_init(sizeof(struct proc), 0, 0, 0,
358 	    "procpl", NULL, IPL_NONE, NULL, NULL, NULL);
359 
360 	proc_listener = kauth_listen_scope(KAUTH_SCOPE_PROCESS,
361 	    proc_listener_cb, NULL);
362 }
363 
364 void
365 procinit_sysctl(void)
366 {
367 	static struct sysctllog *clog;
368 
369 	sysctl_createv(&clog, 0, NULL, NULL,
370 		       CTLFLAG_PERMANENT,
371 		       CTLTYPE_NODE, "proc",
372 		       SYSCTL_DESCR("System-wide process information"),
373 		       sysctl_doeproc, 0, NULL, 0,
374 		       CTL_KERN, KERN_PROC, CTL_EOL);
375 	sysctl_createv(&clog, 0, NULL, NULL,
376 		       CTLFLAG_PERMANENT,
377 		       CTLTYPE_NODE, "proc2",
378 		       SYSCTL_DESCR("Machine-independent process information"),
379 		       sysctl_doeproc, 0, NULL, 0,
380 		       CTL_KERN, KERN_PROC2, CTL_EOL);
381 	sysctl_createv(&clog, 0, NULL, NULL,
382 		       CTLFLAG_PERMANENT,
383 		       CTLTYPE_NODE, "proc_args",
384 		       SYSCTL_DESCR("Process argument information"),
385 		       sysctl_kern_proc_args, 0, NULL, 0,
386 		       CTL_KERN, KERN_PROC_ARGS, CTL_EOL);
387 
388 	/*
389 	  "nodes" under these:
390 
391 	  KERN_PROC_ALL
392 	  KERN_PROC_PID pid
393 	  KERN_PROC_PGRP pgrp
394 	  KERN_PROC_SESSION sess
395 	  KERN_PROC_TTY tty
396 	  KERN_PROC_UID uid
397 	  KERN_PROC_RUID uid
398 	  KERN_PROC_GID gid
399 	  KERN_PROC_RGID gid
400 
401 	  all in all, probably not worth the effort...
402 	*/
403 }
404 
405 /*
406  * Initialize process 0.
407  */
408 void
409 proc0_init(void)
410 {
411 	struct proc *p;
412 	struct pgrp *pg;
413 	struct rlimit *rlim;
414 	rlim_t lim;
415 	int i;
416 
417 	p = &proc0;
418 	pg = &pgrp0;
419 
420 	mutex_init(&p->p_stmutex, MUTEX_DEFAULT, IPL_HIGH);
421 	mutex_init(&p->p_auxlock, MUTEX_DEFAULT, IPL_NONE);
422 	p->p_lock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NONE);
423 
424 	rw_init(&p->p_reflock);
425 	cv_init(&p->p_waitcv, "wait");
426 	cv_init(&p->p_lwpcv, "lwpwait");
427 
428 	LIST_INSERT_HEAD(&p->p_lwps, &lwp0, l_sibling);
429 
430 	pid_table[0].pt_proc = p;
431 	LIST_INSERT_HEAD(&allproc, p, p_list);
432 
433 	pid_table[0].pt_pgrp = pg;
434 	LIST_INSERT_HEAD(&pg->pg_members, p, p_pglist);
435 
436 #ifdef __HAVE_SYSCALL_INTERN
437 	(*p->p_emul->e_syscall_intern)(p);
438 #endif
439 
440 	/* Create credentials. */
441 	cred0 = kauth_cred_alloc();
442 	p->p_cred = cred0;
443 
444 	/* Create the CWD info. */
445 	rw_init(&cwdi0.cwdi_lock);
446 
447 	/* Create the limits structures. */
448 	mutex_init(&limit0.pl_lock, MUTEX_DEFAULT, IPL_NONE);
449 
450 	rlim = limit0.pl_rlimit;
451 	for (i = 0; i < __arraycount(limit0.pl_rlimit); i++) {
452 		rlim[i].rlim_cur = RLIM_INFINITY;
453 		rlim[i].rlim_max = RLIM_INFINITY;
454 	}
455 
456 	rlim[RLIMIT_NOFILE].rlim_max = maxfiles;
457 	rlim[RLIMIT_NOFILE].rlim_cur = maxfiles < nofile ? maxfiles : nofile;
458 
459 	rlim[RLIMIT_NPROC].rlim_max = maxproc;
460 	rlim[RLIMIT_NPROC].rlim_cur = maxproc < maxuprc ? maxproc : maxuprc;
461 
462 	lim = MIN(VM_MAXUSER_ADDRESS, ctob((rlim_t)uvmexp.free));
463 	rlim[RLIMIT_RSS].rlim_max = lim;
464 	rlim[RLIMIT_MEMLOCK].rlim_max = lim;
465 	rlim[RLIMIT_MEMLOCK].rlim_cur = lim / 3;
466 
467 	rlim[RLIMIT_NTHR].rlim_max = maxlwp;
468 	rlim[RLIMIT_NTHR].rlim_cur = maxlwp < maxuprc ? maxlwp : maxuprc;
469 
470 	/* Note that default core name has zero length. */
471 	limit0.pl_corename = defcorename;
472 	limit0.pl_cnlen = 0;
473 	limit0.pl_refcnt = 1;
474 	limit0.pl_writeable = false;
475 	limit0.pl_sv_limit = NULL;
476 
477 	/* Configure virtual memory system, set vm rlimits. */
478 	uvm_init_limits(p);
479 
480 	/* Initialize file descriptor table for proc0. */
481 	fd_init(&filedesc0);
482 
483 	/*
484 	 * Initialize proc0's vmspace, which uses the kernel pmap.
485 	 * All kernel processes (which never have user space mappings)
486 	 * share proc0's vmspace, and thus, the kernel pmap.
487 	 */
488 	uvmspace_init(&vmspace0, pmap_kernel(), round_page(VM_MIN_ADDRESS),
489 	    trunc_page(VM_MAXUSER_ADDRESS),
490 #ifdef __USE_TOPDOWN_VM
491 	    true
492 #else
493 	    false
494 #endif
495 	    );
496 
497 	/* Initialize signal state for proc0. XXX IPL_SCHED */
498 	mutex_init(&p->p_sigacts->sa_mutex, MUTEX_DEFAULT, IPL_SCHED);
499 	siginit(p);
500 
501 	proc_initspecific(p);
502 	kdtrace_proc_ctor(NULL, p);
503 }
504 
505 /*
506  * Session reference counting.
507  */
508 
509 void
510 proc_sesshold(struct session *ss)
511 {
512 
513 	KASSERT(mutex_owned(proc_lock));
514 	ss->s_count++;
515 }
516 
517 void
518 proc_sessrele(struct session *ss)
519 {
520 
521 	KASSERT(mutex_owned(proc_lock));
522 	/*
523 	 * We keep the pgrp with the same id as the session in order to
524 	 * stop a process being given the same pid.  Since the pgrp holds
525 	 * a reference to the session, it must be a 'zombie' pgrp by now.
526 	 */
527 	if (--ss->s_count == 0) {
528 		struct pgrp *pg;
529 
530 		pg = pg_remove(ss->s_sid);
531 		mutex_exit(proc_lock);
532 
533 		kmem_free(pg, sizeof(struct pgrp));
534 		kmem_free(ss, sizeof(struct session));
535 	} else {
536 		mutex_exit(proc_lock);
537 	}
538 }
539 
540 /*
541  * Check that the specified process group is in the session of the
542  * specified process.
543  * Treats -ve ids as process ids.
544  * Used to validate TIOCSPGRP requests.
545  */
546 int
547 pgid_in_session(struct proc *p, pid_t pg_id)
548 {
549 	struct pgrp *pgrp;
550 	struct session *session;
551 	int error;
552 
553 	mutex_enter(proc_lock);
554 	if (pg_id < 0) {
555 		struct proc *p1 = proc_find(-pg_id);
556 		if (p1 == NULL) {
557 			error = EINVAL;
558 			goto fail;
559 		}
560 		pgrp = p1->p_pgrp;
561 	} else {
562 		pgrp = pgrp_find(pg_id);
563 		if (pgrp == NULL) {
564 			error = EINVAL;
565 			goto fail;
566 		}
567 	}
568 	session = pgrp->pg_session;
569 	error = (session != p->p_pgrp->pg_session) ? EPERM : 0;
570 fail:
571 	mutex_exit(proc_lock);
572 	return error;
573 }
574 
575 /*
576  * p_inferior: is p an inferior of q?
577  */
578 static inline bool
579 p_inferior(struct proc *p, struct proc *q)
580 {
581 
582 	KASSERT(mutex_owned(proc_lock));
583 
584 	for (; p != q; p = p->p_pptr)
585 		if (p->p_pid == 0)
586 			return false;
587 	return true;
588 }
589 
590 /*
591  * proc_find: locate a process by the ID.
592  *
593  * => Must be called with proc_lock held.
594  */
595 proc_t *
596 proc_find_raw(pid_t pid)
597 {
598 	struct pid_table *pt;
599 	proc_t *p;
600 
601 	KASSERT(mutex_owned(proc_lock));
602 	pt = &pid_table[pid & pid_tbl_mask];
603 	p = pt->pt_proc;
604 	if (__predict_false(!P_VALID(p) || pt->pt_pid != pid)) {
605 		return NULL;
606 	}
607 	return p;
608 }
609 
610 proc_t *
611 proc_find(pid_t pid)
612 {
613 	proc_t *p;
614 
615 	p = proc_find_raw(pid);
616 	if (__predict_false(p == NULL)) {
617 		return NULL;
618 	}
619 
620 	/*
621 	 * Only allow live processes to be found by PID.
622 	 * XXX: p_stat might change, since unlocked.
623 	 */
624 	if (__predict_true(p->p_stat == SACTIVE || p->p_stat == SSTOP)) {
625 		return p;
626 	}
627 	return NULL;
628 }
629 
630 /*
631  * pgrp_find: locate a process group by the ID.
632  *
633  * => Must be called with proc_lock held.
634  */
635 struct pgrp *
636 pgrp_find(pid_t pgid)
637 {
638 	struct pgrp *pg;
639 
640 	KASSERT(mutex_owned(proc_lock));
641 
642 	pg = pid_table[pgid & pid_tbl_mask].pt_pgrp;
643 
644 	/*
645 	 * Cannot look up a process group that only exists because the
646 	 * session has not died yet (traditional).
647 	 */
648 	if (pg == NULL || pg->pg_id != pgid || LIST_EMPTY(&pg->pg_members)) {
649 		return NULL;
650 	}
651 	return pg;
652 }
653 
654 static void
655 expand_pid_table(void)
656 {
657 	size_t pt_size, tsz;
658 	struct pid_table *n_pt, *new_pt;
659 	struct proc *proc;
660 	struct pgrp *pgrp;
661 	pid_t pid, rpid;
662 	u_int i;
663 	uint new_pt_mask;
664 
665 	pt_size = pid_tbl_mask + 1;
666 	tsz = pt_size * 2 * sizeof(struct pid_table);
667 	new_pt = kmem_alloc(tsz, KM_SLEEP);
668 	new_pt_mask = pt_size * 2 - 1;
669 
670 	mutex_enter(proc_lock);
671 	if (pt_size != pid_tbl_mask + 1) {
672 		/* Another process beat us to it... */
673 		mutex_exit(proc_lock);
674 		kmem_free(new_pt, tsz);
675 		return;
676 	}
677 
678 	/*
679 	 * Copy entries from old table into new one.
680 	 * If 'pid' is 'odd' we need to place in the upper half,
681 	 * even pid's to the lower half.
682 	 * Free items stay in the low half so we don't have to
683 	 * fixup the reference to them.
684 	 * We stuff free items on the front of the freelist
685 	 * because we can't write to unmodified entries.
686 	 * Processing the table backwards maintains a semblance
687 	 * of issuing pid numbers that increase with time.
688 	 */
689 	i = pt_size - 1;
690 	n_pt = new_pt + i;
691 	for (; ; i--, n_pt--) {
692 		proc = pid_table[i].pt_proc;
693 		pgrp = pid_table[i].pt_pgrp;
694 		if (!P_VALID(proc)) {
695 			/* Up 'use count' so that link is valid */
696 			pid = (P_NEXT(proc) + pt_size) & ~pt_size;
697 			rpid = 0;
698 			proc = P_FREE(pid);
699 			if (pgrp)
700 				pid = pgrp->pg_id;
701 		} else {
702 			pid = pid_table[i].pt_pid;
703 			rpid = pid;
704 		}
705 
706 		/* Save entry in appropriate half of table */
707 		n_pt[pid & pt_size].pt_proc = proc;
708 		n_pt[pid & pt_size].pt_pgrp = pgrp;
709 		n_pt[pid & pt_size].pt_pid = rpid;
710 
711 		/* Put other piece on start of free list */
712 		pid = (pid ^ pt_size) & ~pid_tbl_mask;
713 		n_pt[pid & pt_size].pt_proc =
714 			P_FREE((pid & ~pt_size) | next_free_pt);
715 		n_pt[pid & pt_size].pt_pgrp = 0;
716 		n_pt[pid & pt_size].pt_pid = 0;
717 
718 		next_free_pt = i | (pid & pt_size);
719 		if (i == 0)
720 			break;
721 	}
722 
723 	/* Save old table size and switch tables */
724 	tsz = pt_size * sizeof(struct pid_table);
725 	n_pt = pid_table;
726 	pid_table = new_pt;
727 	pid_tbl_mask = new_pt_mask;
728 
729 	/*
730 	 * pid_max starts as PID_MAX (= 30000), once we have 16384
731 	 * allocated pids we need it to be larger!
732 	 */
733 	if (pid_tbl_mask > PID_MAX) {
734 		pid_max = pid_tbl_mask * 2 + 1;
735 		pid_alloc_lim |= pid_alloc_lim << 1;
736 	} else
737 		pid_alloc_lim <<= 1;	/* doubles number of free slots... */
738 
739 	mutex_exit(proc_lock);
740 	kmem_free(n_pt, tsz);
741 }
742 
743 struct proc *
744 proc_alloc(void)
745 {
746 	struct proc *p;
747 
748 	p = pool_cache_get(proc_cache, PR_WAITOK);
749 	p->p_stat = SIDL;			/* protect against others */
750 	proc_initspecific(p);
751 	kdtrace_proc_ctor(NULL, p);
752 	p->p_pid = -1;
753 	proc_alloc_pid(p);
754 	return p;
755 }
756 
757 /*
758  * proc_alloc_pid: allocate PID and record the given proc 'p' so that
759  * proc_find_raw() can find it by the PID.
760  */
761 
762 pid_t
763 proc_alloc_pid(struct proc *p)
764 {
765 	struct pid_table *pt;
766 	pid_t pid;
767 	int nxt;
768 
769 	for (;;expand_pid_table()) {
770 		if (__predict_false(pid_alloc_cnt >= pid_alloc_lim))
771 			/* ensure pids cycle through 2000+ values */
772 			continue;
773 		mutex_enter(proc_lock);
774 		pt = &pid_table[next_free_pt];
775 #ifdef DIAGNOSTIC
776 		if (__predict_false(P_VALID(pt->pt_proc) || pt->pt_pgrp))
777 			panic("proc_alloc: slot busy");
778 #endif
779 		nxt = P_NEXT(pt->pt_proc);
780 		if (nxt & pid_tbl_mask)
781 			break;
782 		/* Table full - expand (NB last entry not used....) */
783 		mutex_exit(proc_lock);
784 	}
785 
786 	/* pid is 'saved use count' + 'size' + entry */
787 	pid = (nxt & ~pid_tbl_mask) + pid_tbl_mask + 1 + next_free_pt;
788 	if ((uint)pid > (uint)pid_max)
789 		pid &= pid_tbl_mask;
790 	next_free_pt = nxt & pid_tbl_mask;
791 
792 	/* Grab table slot */
793 	pt->pt_proc = p;
794 
795 	KASSERT(pt->pt_pid == 0);
796 	pt->pt_pid = pid;
797 	if (p->p_pid == -1) {
798 		p->p_pid = pid;
799 	}
800 	pid_alloc_cnt++;
801 	mutex_exit(proc_lock);
802 
803 	return pid;
804 }
805 
806 /*
807  * Free a process id - called from proc_free (in kern_exit.c)
808  *
809  * Called with the proc_lock held.
810  */
811 void
812 proc_free_pid(pid_t pid)
813 {
814 	struct pid_table *pt;
815 
816 	KASSERT(mutex_owned(proc_lock));
817 
818 	pt = &pid_table[pid & pid_tbl_mask];
819 
820 	/* save pid use count in slot */
821 	pt->pt_proc = P_FREE(pid & ~pid_tbl_mask);
822 	KASSERT(pt->pt_pid == pid);
823 	pt->pt_pid = 0;
824 
825 	if (pt->pt_pgrp == NULL) {
826 		/* link last freed entry onto ours */
827 		pid &= pid_tbl_mask;
828 		pt = &pid_table[last_free_pt];
829 		pt->pt_proc = P_FREE(P_NEXT(pt->pt_proc) | pid);
830 		pt->pt_pid = 0;
831 		last_free_pt = pid;
832 		pid_alloc_cnt--;
833 	}
834 
835 	atomic_dec_uint(&nprocs);
836 }
837 
838 void
839 proc_free_mem(struct proc *p)
840 {
841 
842 	kdtrace_proc_dtor(NULL, p);
843 	pool_cache_put(proc_cache, p);
844 }
845 
846 /*
847  * proc_enterpgrp: move p to a new or existing process group (and session).
848  *
849  * If we are creating a new pgrp, the pgid should equal
850  * the calling process' pid.
851  * If is only valid to enter a process group that is in the session
852  * of the process.
853  * Also mksess should only be set if we are creating a process group
854  *
855  * Only called from sys_setsid, sys_setpgid and posix_spawn/spawn_return.
856  */
857 int
858 proc_enterpgrp(struct proc *curp, pid_t pid, pid_t pgid, bool mksess)
859 {
860 	struct pgrp *new_pgrp, *pgrp;
861 	struct session *sess;
862 	struct proc *p;
863 	int rval;
864 	pid_t pg_id = NO_PGID;
865 
866 	sess = mksess ? kmem_alloc(sizeof(*sess), KM_SLEEP) : NULL;
867 
868 	/* Allocate data areas we might need before doing any validity checks */
869 	mutex_enter(proc_lock);		/* Because pid_table might change */
870 	if (pid_table[pgid & pid_tbl_mask].pt_pgrp == 0) {
871 		mutex_exit(proc_lock);
872 		new_pgrp = kmem_alloc(sizeof(*new_pgrp), KM_SLEEP);
873 		mutex_enter(proc_lock);
874 	} else
875 		new_pgrp = NULL;
876 	rval = EPERM;	/* most common error (to save typing) */
877 
878 	/* Check pgrp exists or can be created */
879 	pgrp = pid_table[pgid & pid_tbl_mask].pt_pgrp;
880 	if (pgrp != NULL && pgrp->pg_id != pgid)
881 		goto done;
882 
883 	/* Can only set another process under restricted circumstances. */
884 	if (pid != curp->p_pid) {
885 		/* Must exist and be one of our children... */
886 		p = proc_find(pid);
887 		if (p == NULL || !p_inferior(p, curp)) {
888 			rval = ESRCH;
889 			goto done;
890 		}
891 		/* ... in the same session... */
892 		if (sess != NULL || p->p_session != curp->p_session)
893 			goto done;
894 		/* ... existing pgid must be in same session ... */
895 		if (pgrp != NULL && pgrp->pg_session != p->p_session)
896 			goto done;
897 		/* ... and not done an exec. */
898 		if (p->p_flag & PK_EXEC) {
899 			rval = EACCES;
900 			goto done;
901 		}
902 	} else {
903 		/* ... setsid() cannot re-enter a pgrp */
904 		if (mksess && (curp->p_pgid == curp->p_pid ||
905 		    pgrp_find(curp->p_pid)))
906 			goto done;
907 		p = curp;
908 	}
909 
910 	/* Changing the process group/session of a session
911 	   leader is definitely off limits. */
912 	if (SESS_LEADER(p)) {
913 		if (sess == NULL && p->p_pgrp == pgrp)
914 			/* unless it's a definite noop */
915 			rval = 0;
916 		goto done;
917 	}
918 
919 	/* Can only create a process group with id of process */
920 	if (pgrp == NULL && pgid != pid)
921 		goto done;
922 
923 	/* Can only create a session if creating pgrp */
924 	if (sess != NULL && pgrp != NULL)
925 		goto done;
926 
927 	/* Check we allocated memory for a pgrp... */
928 	if (pgrp == NULL && new_pgrp == NULL)
929 		goto done;
930 
931 	/* Don't attach to 'zombie' pgrp */
932 	if (pgrp != NULL && LIST_EMPTY(&pgrp->pg_members))
933 		goto done;
934 
935 	/* Expect to succeed now */
936 	rval = 0;
937 
938 	if (pgrp == p->p_pgrp)
939 		/* nothing to do */
940 		goto done;
941 
942 	/* Ok all setup, link up required structures */
943 
944 	if (pgrp == NULL) {
945 		pgrp = new_pgrp;
946 		new_pgrp = NULL;
947 		if (sess != NULL) {
948 			sess->s_sid = p->p_pid;
949 			sess->s_leader = p;
950 			sess->s_count = 1;
951 			sess->s_ttyvp = NULL;
952 			sess->s_ttyp = NULL;
953 			sess->s_flags = p->p_session->s_flags & ~S_LOGIN_SET;
954 			memcpy(sess->s_login, p->p_session->s_login,
955 			    sizeof(sess->s_login));
956 			p->p_lflag &= ~PL_CONTROLT;
957 		} else {
958 			sess = p->p_pgrp->pg_session;
959 			proc_sesshold(sess);
960 		}
961 		pgrp->pg_session = sess;
962 		sess = NULL;
963 
964 		pgrp->pg_id = pgid;
965 		LIST_INIT(&pgrp->pg_members);
966 #ifdef DIAGNOSTIC
967 		if (__predict_false(pid_table[pgid & pid_tbl_mask].pt_pgrp))
968 			panic("enterpgrp: pgrp table slot in use");
969 		if (__predict_false(mksess && p != curp))
970 			panic("enterpgrp: mksession and p != curproc");
971 #endif
972 		pid_table[pgid & pid_tbl_mask].pt_pgrp = pgrp;
973 		pgrp->pg_jobc = 0;
974 	}
975 
976 	/*
977 	 * Adjust eligibility of affected pgrps to participate in job control.
978 	 * Increment eligibility counts before decrementing, otherwise we
979 	 * could reach 0 spuriously during the first call.
980 	 */
981 	fixjobc(p, pgrp, 1);
982 	fixjobc(p, p->p_pgrp, 0);
983 
984 	/* Interlock with ttread(). */
985 	mutex_spin_enter(&tty_lock);
986 
987 	/* Move process to requested group. */
988 	LIST_REMOVE(p, p_pglist);
989 	if (LIST_EMPTY(&p->p_pgrp->pg_members))
990 		/* defer delete until we've dumped the lock */
991 		pg_id = p->p_pgrp->pg_id;
992 	p->p_pgrp = pgrp;
993 	LIST_INSERT_HEAD(&pgrp->pg_members, p, p_pglist);
994 
995 	/* Done with the swap; we can release the tty mutex. */
996 	mutex_spin_exit(&tty_lock);
997 
998     done:
999 	if (pg_id != NO_PGID) {
1000 		/* Releases proc_lock. */
1001 		pg_delete(pg_id);
1002 	} else {
1003 		mutex_exit(proc_lock);
1004 	}
1005 	if (sess != NULL)
1006 		kmem_free(sess, sizeof(*sess));
1007 	if (new_pgrp != NULL)
1008 		kmem_free(new_pgrp, sizeof(*new_pgrp));
1009 #ifdef DEBUG_PGRP
1010 	if (__predict_false(rval))
1011 		printf("enterpgrp(%d,%d,%d), curproc %d, rval %d\n",
1012 			pid, pgid, mksess, curp->p_pid, rval);
1013 #endif
1014 	return rval;
1015 }
1016 
1017 /*
1018  * proc_leavepgrp: remove a process from its process group.
1019  *  => must be called with the proc_lock held, which will be released;
1020  */
1021 void
1022 proc_leavepgrp(struct proc *p)
1023 {
1024 	struct pgrp *pgrp;
1025 
1026 	KASSERT(mutex_owned(proc_lock));
1027 
1028 	/* Interlock with ttread() */
1029 	mutex_spin_enter(&tty_lock);
1030 	pgrp = p->p_pgrp;
1031 	LIST_REMOVE(p, p_pglist);
1032 	p->p_pgrp = NULL;
1033 	mutex_spin_exit(&tty_lock);
1034 
1035 	if (LIST_EMPTY(&pgrp->pg_members)) {
1036 		/* Releases proc_lock. */
1037 		pg_delete(pgrp->pg_id);
1038 	} else {
1039 		mutex_exit(proc_lock);
1040 	}
1041 }
1042 
1043 /*
1044  * pg_remove: remove a process group from the table.
1045  *  => must be called with the proc_lock held;
1046  *  => returns process group to free;
1047  */
1048 static struct pgrp *
1049 pg_remove(pid_t pg_id)
1050 {
1051 	struct pgrp *pgrp;
1052 	struct pid_table *pt;
1053 
1054 	KASSERT(mutex_owned(proc_lock));
1055 
1056 	pt = &pid_table[pg_id & pid_tbl_mask];
1057 	pgrp = pt->pt_pgrp;
1058 
1059 	KASSERT(pgrp != NULL);
1060 	KASSERT(pgrp->pg_id == pg_id);
1061 	KASSERT(LIST_EMPTY(&pgrp->pg_members));
1062 
1063 	pt->pt_pgrp = NULL;
1064 
1065 	if (!P_VALID(pt->pt_proc)) {
1066 		/* Orphaned pgrp, put slot onto free list. */
1067 		KASSERT((P_NEXT(pt->pt_proc) & pid_tbl_mask) == 0);
1068 		pg_id &= pid_tbl_mask;
1069 		pt = &pid_table[last_free_pt];
1070 		pt->pt_proc = P_FREE(P_NEXT(pt->pt_proc) | pg_id);
1071 		KASSERT(pt->pt_pid == 0);
1072 		last_free_pt = pg_id;
1073 		pid_alloc_cnt--;
1074 	}
1075 	return pgrp;
1076 }
1077 
1078 /*
1079  * pg_delete: delete and free a process group.
1080  *  => must be called with the proc_lock held, which will be released.
1081  */
1082 static void
1083 pg_delete(pid_t pg_id)
1084 {
1085 	struct pgrp *pg;
1086 	struct tty *ttyp;
1087 	struct session *ss;
1088 
1089 	KASSERT(mutex_owned(proc_lock));
1090 
1091 	pg = pid_table[pg_id & pid_tbl_mask].pt_pgrp;
1092 	if (pg == NULL || pg->pg_id != pg_id || !LIST_EMPTY(&pg->pg_members)) {
1093 		mutex_exit(proc_lock);
1094 		return;
1095 	}
1096 
1097 	ss = pg->pg_session;
1098 
1099 	/* Remove reference (if any) from tty to this process group */
1100 	mutex_spin_enter(&tty_lock);
1101 	ttyp = ss->s_ttyp;
1102 	if (ttyp != NULL && ttyp->t_pgrp == pg) {
1103 		ttyp->t_pgrp = NULL;
1104 		KASSERT(ttyp->t_session == ss);
1105 	}
1106 	mutex_spin_exit(&tty_lock);
1107 
1108 	/*
1109 	 * The leading process group in a session is freed by proc_sessrele(),
1110 	 * if last reference.  Note: proc_sessrele() releases proc_lock.
1111 	 */
1112 	pg = (ss->s_sid != pg->pg_id) ? pg_remove(pg_id) : NULL;
1113 	proc_sessrele(ss);
1114 
1115 	if (pg != NULL) {
1116 		/* Free it, if was not done by proc_sessrele(). */
1117 		kmem_free(pg, sizeof(struct pgrp));
1118 	}
1119 }
1120 
1121 /*
1122  * Adjust pgrp jobc counters when specified process changes process group.
1123  * We count the number of processes in each process group that "qualify"
1124  * the group for terminal job control (those with a parent in a different
1125  * process group of the same session).  If that count reaches zero, the
1126  * process group becomes orphaned.  Check both the specified process'
1127  * process group and that of its children.
1128  * entering == 0 => p is leaving specified group.
1129  * entering == 1 => p is entering specified group.
1130  *
1131  * Call with proc_lock held.
1132  */
1133 void
1134 fixjobc(struct proc *p, struct pgrp *pgrp, int entering)
1135 {
1136 	struct pgrp *hispgrp;
1137 	struct session *mysession = pgrp->pg_session;
1138 	struct proc *child;
1139 
1140 	KASSERT(mutex_owned(proc_lock));
1141 
1142 	/*
1143 	 * Check p's parent to see whether p qualifies its own process
1144 	 * group; if so, adjust count for p's process group.
1145 	 */
1146 	hispgrp = p->p_pptr->p_pgrp;
1147 	if (hispgrp != pgrp && hispgrp->pg_session == mysession) {
1148 		if (entering) {
1149 			pgrp->pg_jobc++;
1150 			p->p_lflag &= ~PL_ORPHANPG;
1151 		} else if (--pgrp->pg_jobc == 0)
1152 			orphanpg(pgrp);
1153 	}
1154 
1155 	/*
1156 	 * Check this process' children to see whether they qualify
1157 	 * their process groups; if so, adjust counts for children's
1158 	 * process groups.
1159 	 */
1160 	LIST_FOREACH(child, &p->p_children, p_sibling) {
1161 		hispgrp = child->p_pgrp;
1162 		if (hispgrp != pgrp && hispgrp->pg_session == mysession &&
1163 		    !P_ZOMBIE(child)) {
1164 			if (entering) {
1165 				child->p_lflag &= ~PL_ORPHANPG;
1166 				hispgrp->pg_jobc++;
1167 			} else if (--hispgrp->pg_jobc == 0)
1168 				orphanpg(hispgrp);
1169 		}
1170 	}
1171 }
1172 
1173 /*
1174  * A process group has become orphaned;
1175  * if there are any stopped processes in the group,
1176  * hang-up all process in that group.
1177  *
1178  * Call with proc_lock held.
1179  */
1180 static void
1181 orphanpg(struct pgrp *pg)
1182 {
1183 	struct proc *p;
1184 
1185 	KASSERT(mutex_owned(proc_lock));
1186 
1187 	LIST_FOREACH(p, &pg->pg_members, p_pglist) {
1188 		if (p->p_stat == SSTOP) {
1189 			p->p_lflag |= PL_ORPHANPG;
1190 			psignal(p, SIGHUP);
1191 			psignal(p, SIGCONT);
1192 		}
1193 	}
1194 }
1195 
1196 #ifdef DDB
1197 #include <ddb/db_output.h>
1198 void pidtbl_dump(void);
1199 void
1200 pidtbl_dump(void)
1201 {
1202 	struct pid_table *pt;
1203 	struct proc *p;
1204 	struct pgrp *pgrp;
1205 	int id;
1206 
1207 	db_printf("pid table %p size %x, next %x, last %x\n",
1208 		pid_table, pid_tbl_mask+1,
1209 		next_free_pt, last_free_pt);
1210 	for (pt = pid_table, id = 0; id <= pid_tbl_mask; id++, pt++) {
1211 		p = pt->pt_proc;
1212 		if (!P_VALID(p) && !pt->pt_pgrp)
1213 			continue;
1214 		db_printf("  id %x: ", id);
1215 		if (P_VALID(p))
1216 			db_printf("slotpid %d proc %p id %d (0x%x) %s\n",
1217 				pt->pt_pid, p, p->p_pid, p->p_pid, p->p_comm);
1218 		else
1219 			db_printf("next %x use %x\n",
1220 				P_NEXT(p) & pid_tbl_mask,
1221 				P_NEXT(p) & ~pid_tbl_mask);
1222 		if ((pgrp = pt->pt_pgrp)) {
1223 			db_printf("\tsession %p, sid %d, count %d, login %s\n",
1224 			    pgrp->pg_session, pgrp->pg_session->s_sid,
1225 			    pgrp->pg_session->s_count,
1226 			    pgrp->pg_session->s_login);
1227 			db_printf("\tpgrp %p, pg_id %d, pg_jobc %d, members %p\n",
1228 			    pgrp, pgrp->pg_id, pgrp->pg_jobc,
1229 			    LIST_FIRST(&pgrp->pg_members));
1230 			LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
1231 				db_printf("\t\tpid %d addr %p pgrp %p %s\n",
1232 				    p->p_pid, p, p->p_pgrp, p->p_comm);
1233 			}
1234 		}
1235 	}
1236 }
1237 #endif /* DDB */
1238 
1239 #ifdef KSTACK_CHECK_MAGIC
1240 
1241 #define	KSTACK_MAGIC	0xdeadbeaf
1242 
1243 /* XXX should be per process basis? */
1244 static int	kstackleftmin = KSTACK_SIZE;
1245 static int	kstackleftthres = KSTACK_SIZE / 8;
1246 
1247 void
1248 kstack_setup_magic(const struct lwp *l)
1249 {
1250 	uint32_t *ip;
1251 	uint32_t const *end;
1252 
1253 	KASSERT(l != NULL);
1254 	KASSERT(l != &lwp0);
1255 
1256 	/*
1257 	 * fill all the stack with magic number
1258 	 * so that later modification on it can be detected.
1259 	 */
1260 	ip = (uint32_t *)KSTACK_LOWEST_ADDR(l);
1261 	end = (uint32_t *)((char *)KSTACK_LOWEST_ADDR(l) + KSTACK_SIZE);
1262 	for (; ip < end; ip++) {
1263 		*ip = KSTACK_MAGIC;
1264 	}
1265 }
1266 
1267 void
1268 kstack_check_magic(const struct lwp *l)
1269 {
1270 	uint32_t const *ip, *end;
1271 	int stackleft;
1272 
1273 	KASSERT(l != NULL);
1274 
1275 	/* don't check proc0 */ /*XXX*/
1276 	if (l == &lwp0)
1277 		return;
1278 
1279 #ifdef __MACHINE_STACK_GROWS_UP
1280 	/* stack grows upwards (eg. hppa) */
1281 	ip = (uint32_t *)((void *)KSTACK_LOWEST_ADDR(l) + KSTACK_SIZE);
1282 	end = (uint32_t *)KSTACK_LOWEST_ADDR(l);
1283 	for (ip--; ip >= end; ip--)
1284 		if (*ip != KSTACK_MAGIC)
1285 			break;
1286 
1287 	stackleft = (void *)KSTACK_LOWEST_ADDR(l) + KSTACK_SIZE - (void *)ip;
1288 #else /* __MACHINE_STACK_GROWS_UP */
1289 	/* stack grows downwards (eg. i386) */
1290 	ip = (uint32_t *)KSTACK_LOWEST_ADDR(l);
1291 	end = (uint32_t *)((char *)KSTACK_LOWEST_ADDR(l) + KSTACK_SIZE);
1292 	for (; ip < end; ip++)
1293 		if (*ip != KSTACK_MAGIC)
1294 			break;
1295 
1296 	stackleft = ((const char *)ip) - (const char *)KSTACK_LOWEST_ADDR(l);
1297 #endif /* __MACHINE_STACK_GROWS_UP */
1298 
1299 	if (kstackleftmin > stackleft) {
1300 		kstackleftmin = stackleft;
1301 		if (stackleft < kstackleftthres)
1302 			printf("warning: kernel stack left %d bytes"
1303 			    "(pid %u:lid %u)\n", stackleft,
1304 			    (u_int)l->l_proc->p_pid, (u_int)l->l_lid);
1305 	}
1306 
1307 	if (stackleft <= 0) {
1308 		panic("magic on the top of kernel stack changed for "
1309 		    "pid %u, lid %u: maybe kernel stack overflow",
1310 		    (u_int)l->l_proc->p_pid, (u_int)l->l_lid);
1311 	}
1312 }
1313 #endif /* KSTACK_CHECK_MAGIC */
1314 
1315 int
1316 proclist_foreach_call(struct proclist *list,
1317     int (*callback)(struct proc *, void *arg), void *arg)
1318 {
1319 	struct proc marker;
1320 	struct proc *p;
1321 	int ret = 0;
1322 
1323 	marker.p_flag = PK_MARKER;
1324 	mutex_enter(proc_lock);
1325 	for (p = LIST_FIRST(list); ret == 0 && p != NULL;) {
1326 		if (p->p_flag & PK_MARKER) {
1327 			p = LIST_NEXT(p, p_list);
1328 			continue;
1329 		}
1330 		LIST_INSERT_AFTER(p, &marker, p_list);
1331 		ret = (*callback)(p, arg);
1332 		KASSERT(mutex_owned(proc_lock));
1333 		p = LIST_NEXT(&marker, p_list);
1334 		LIST_REMOVE(&marker, p_list);
1335 	}
1336 	mutex_exit(proc_lock);
1337 
1338 	return ret;
1339 }
1340 
1341 int
1342 proc_vmspace_getref(struct proc *p, struct vmspace **vm)
1343 {
1344 
1345 	/* XXXCDC: how should locking work here? */
1346 
1347 	/* curproc exception is for coredump. */
1348 
1349 	if ((p != curproc && (p->p_sflag & PS_WEXIT) != 0) ||
1350 	    (p->p_vmspace->vm_refcnt < 1)) { /* XXX */
1351 		return EFAULT;
1352 	}
1353 
1354 	uvmspace_addref(p->p_vmspace);
1355 	*vm = p->p_vmspace;
1356 
1357 	return 0;
1358 }
1359 
1360 /*
1361  * Acquire a write lock on the process credential.
1362  */
1363 void
1364 proc_crmod_enter(void)
1365 {
1366 	struct lwp *l = curlwp;
1367 	struct proc *p = l->l_proc;
1368 	kauth_cred_t oc;
1369 
1370 	/* Reset what needs to be reset in plimit. */
1371 	if (p->p_limit->pl_corename != defcorename) {
1372 		lim_setcorename(p, defcorename, 0);
1373 	}
1374 
1375 	mutex_enter(p->p_lock);
1376 
1377 	/* Ensure the LWP cached credentials are up to date. */
1378 	if ((oc = l->l_cred) != p->p_cred) {
1379 		kauth_cred_hold(p->p_cred);
1380 		l->l_cred = p->p_cred;
1381 		kauth_cred_free(oc);
1382 	}
1383 }
1384 
1385 /*
1386  * Set in a new process credential, and drop the write lock.  The credential
1387  * must have a reference already.  Optionally, free a no-longer required
1388  * credential.  The scheduler also needs to inspect p_cred, so we also
1389  * briefly acquire the sched state mutex.
1390  */
1391 void
1392 proc_crmod_leave(kauth_cred_t scred, kauth_cred_t fcred, bool sugid)
1393 {
1394 	struct lwp *l = curlwp, *l2;
1395 	struct proc *p = l->l_proc;
1396 	kauth_cred_t oc;
1397 
1398 	KASSERT(mutex_owned(p->p_lock));
1399 
1400 	/* Is there a new credential to set in? */
1401 	if (scred != NULL) {
1402 		p->p_cred = scred;
1403 		LIST_FOREACH(l2, &p->p_lwps, l_sibling) {
1404 			if (l2 != l)
1405 				l2->l_prflag |= LPR_CRMOD;
1406 		}
1407 
1408 		/* Ensure the LWP cached credentials are up to date. */
1409 		if ((oc = l->l_cred) != scred) {
1410 			kauth_cred_hold(scred);
1411 			l->l_cred = scred;
1412 		}
1413 	} else
1414 		oc = NULL;	/* XXXgcc */
1415 
1416 	if (sugid) {
1417 		/*
1418 		 * Mark process as having changed credentials, stops
1419 		 * tracing etc.
1420 		 */
1421 		p->p_flag |= PK_SUGID;
1422 	}
1423 
1424 	mutex_exit(p->p_lock);
1425 
1426 	/* If there is a credential to be released, free it now. */
1427 	if (fcred != NULL) {
1428 		KASSERT(scred != NULL);
1429 		kauth_cred_free(fcred);
1430 		if (oc != scred)
1431 			kauth_cred_free(oc);
1432 	}
1433 }
1434 
1435 /*
1436  * proc_specific_key_create --
1437  *	Create a key for subsystem proc-specific data.
1438  */
1439 int
1440 proc_specific_key_create(specificdata_key_t *keyp, specificdata_dtor_t dtor)
1441 {
1442 
1443 	return (specificdata_key_create(proc_specificdata_domain, keyp, dtor));
1444 }
1445 
1446 /*
1447  * proc_specific_key_delete --
1448  *	Delete a key for subsystem proc-specific data.
1449  */
1450 void
1451 proc_specific_key_delete(specificdata_key_t key)
1452 {
1453 
1454 	specificdata_key_delete(proc_specificdata_domain, key);
1455 }
1456 
1457 /*
1458  * proc_initspecific --
1459  *	Initialize a proc's specificdata container.
1460  */
1461 void
1462 proc_initspecific(struct proc *p)
1463 {
1464 	int error __diagused;
1465 
1466 	error = specificdata_init(proc_specificdata_domain, &p->p_specdataref);
1467 	KASSERT(error == 0);
1468 }
1469 
1470 /*
1471  * proc_finispecific --
1472  *	Finalize a proc's specificdata container.
1473  */
1474 void
1475 proc_finispecific(struct proc *p)
1476 {
1477 
1478 	specificdata_fini(proc_specificdata_domain, &p->p_specdataref);
1479 }
1480 
1481 /*
1482  * proc_getspecific --
1483  *	Return proc-specific data corresponding to the specified key.
1484  */
1485 void *
1486 proc_getspecific(struct proc *p, specificdata_key_t key)
1487 {
1488 
1489 	return (specificdata_getspecific(proc_specificdata_domain,
1490 					 &p->p_specdataref, key));
1491 }
1492 
1493 /*
1494  * proc_setspecific --
1495  *	Set proc-specific data corresponding to the specified key.
1496  */
1497 void
1498 proc_setspecific(struct proc *p, specificdata_key_t key, void *data)
1499 {
1500 
1501 	specificdata_setspecific(proc_specificdata_domain,
1502 				 &p->p_specdataref, key, data);
1503 }
1504 
1505 int
1506 proc_uidmatch(kauth_cred_t cred, kauth_cred_t target)
1507 {
1508 	int r = 0;
1509 
1510 	if (kauth_cred_getuid(cred) != kauth_cred_getuid(target) ||
1511 	    kauth_cred_getuid(cred) != kauth_cred_getsvuid(target)) {
1512 		/*
1513 		 * suid proc of ours or proc not ours
1514 		 */
1515 		r = EPERM;
1516 	} else if (kauth_cred_getgid(target) != kauth_cred_getsvgid(target)) {
1517 		/*
1518 		 * sgid proc has sgid back to us temporarily
1519 		 */
1520 		r = EPERM;
1521 	} else {
1522 		/*
1523 		 * our rgid must be in target's group list (ie,
1524 		 * sub-processes started by a sgid process)
1525 		 */
1526 		int ismember = 0;
1527 
1528 		if (kauth_cred_ismember_gid(cred,
1529 		    kauth_cred_getgid(target), &ismember) != 0 ||
1530 		    !ismember)
1531 			r = EPERM;
1532 	}
1533 
1534 	return (r);
1535 }
1536 
1537 /*
1538  * sysctl stuff
1539  */
1540 
1541 #define KERN_PROCSLOP	(5 * sizeof(struct kinfo_proc))
1542 
1543 static const u_int sysctl_flagmap[] = {
1544 	PK_ADVLOCK, P_ADVLOCK,
1545 	PK_EXEC, P_EXEC,
1546 	PK_NOCLDWAIT, P_NOCLDWAIT,
1547 	PK_32, P_32,
1548 	PK_CLDSIGIGN, P_CLDSIGIGN,
1549 	PK_SUGID, P_SUGID,
1550 	0
1551 };
1552 
1553 static const u_int sysctl_sflagmap[] = {
1554 	PS_NOCLDSTOP, P_NOCLDSTOP,
1555 	PS_WEXIT, P_WEXIT,
1556 	PS_STOPFORK, P_STOPFORK,
1557 	PS_STOPEXEC, P_STOPEXEC,
1558 	PS_STOPEXIT, P_STOPEXIT,
1559 	0
1560 };
1561 
1562 static const u_int sysctl_slflagmap[] = {
1563 	PSL_TRACED, P_TRACED,
1564 	PSL_CHTRACED, P_CHTRACED,
1565 	PSL_SYSCALL, P_SYSCALL,
1566 	0
1567 };
1568 
1569 static const u_int sysctl_lflagmap[] = {
1570 	PL_CONTROLT, P_CONTROLT,
1571 	PL_PPWAIT, P_PPWAIT,
1572 	0
1573 };
1574 
1575 static const u_int sysctl_stflagmap[] = {
1576 	PST_PROFIL, P_PROFIL,
1577 	0
1578 
1579 };
1580 
1581 /* used by kern_lwp also */
1582 const u_int sysctl_lwpflagmap[] = {
1583 	LW_SINTR, L_SINTR,
1584 	LW_SYSTEM, L_SYSTEM,
1585 	0
1586 };
1587 
1588 /*
1589  * Find the most ``active'' lwp of a process and return it for ps display
1590  * purposes
1591  */
1592 static struct lwp *
1593 proc_active_lwp(struct proc *p)
1594 {
1595 	static const int ostat[] = {
1596 		0,
1597 		2,	/* LSIDL */
1598 		6,	/* LSRUN */
1599 		5,	/* LSSLEEP */
1600 		4,	/* LSSTOP */
1601 		0,	/* LSZOMB */
1602 		1,	/* LSDEAD */
1603 		7,	/* LSONPROC */
1604 		3	/* LSSUSPENDED */
1605 	};
1606 
1607 	struct lwp *l, *lp = NULL;
1608 	LIST_FOREACH(l, &p->p_lwps, l_sibling) {
1609 		KASSERT(l->l_stat >= 0 && l->l_stat < __arraycount(ostat));
1610 		if (lp == NULL ||
1611 		    ostat[l->l_stat] > ostat[lp->l_stat] ||
1612 		    (ostat[l->l_stat] == ostat[lp->l_stat] &&
1613 		    l->l_cpticks > lp->l_cpticks)) {
1614 			lp = l;
1615 			continue;
1616 		}
1617 	}
1618 	return lp;
1619 }
1620 
1621 static int
1622 sysctl_doeproc(SYSCTLFN_ARGS)
1623 {
1624 	union {
1625 		struct kinfo_proc kproc;
1626 		struct kinfo_proc2 kproc2;
1627 	} *kbuf;
1628 	struct proc *p, *next, *marker;
1629 	char *where, *dp;
1630 	int type, op, arg, error;
1631 	u_int elem_size, kelem_size, elem_count;
1632 	size_t buflen, needed;
1633 	bool match, zombie, mmmbrains;
1634 
1635 	if (namelen == 1 && name[0] == CTL_QUERY)
1636 		return (sysctl_query(SYSCTLFN_CALL(rnode)));
1637 
1638 	dp = where = oldp;
1639 	buflen = where != NULL ? *oldlenp : 0;
1640 	error = 0;
1641 	needed = 0;
1642 	type = rnode->sysctl_num;
1643 
1644 	if (type == KERN_PROC) {
1645 		if (namelen == 0)
1646 			return EINVAL;
1647 		switch (op = name[0]) {
1648 		case KERN_PROC_ALL:
1649 			if (namelen != 1)
1650 				return EINVAL;
1651 			arg = 0;
1652 			break;
1653 		default:
1654 			if (namelen != 2)
1655 				return EINVAL;
1656 			arg = name[1];
1657 			break;
1658 		}
1659 		elem_count = 0;	/* Hush little compiler, don't you cry */
1660 		kelem_size = elem_size = sizeof(kbuf->kproc);
1661 	} else {
1662 		if (namelen != 4)
1663 			return EINVAL;
1664 		op = name[0];
1665 		arg = name[1];
1666 		elem_size = name[2];
1667 		elem_count = name[3];
1668 		kelem_size = sizeof(kbuf->kproc2);
1669 	}
1670 
1671 	sysctl_unlock();
1672 
1673 	kbuf = kmem_alloc(sizeof(*kbuf), KM_SLEEP);
1674 	marker = kmem_alloc(sizeof(*marker), KM_SLEEP);
1675 	marker->p_flag = PK_MARKER;
1676 
1677 	mutex_enter(proc_lock);
1678 	/*
1679 	 * Start with zombies to prevent reporting processes twice, in case they
1680 	 * are dying and being moved from the list of alive processes to zombies.
1681 	 */
1682 	mmmbrains = true;
1683 	for (p = LIST_FIRST(&zombproc);; p = next) {
1684 		if (p == NULL) {
1685 			if (mmmbrains) {
1686 				p = LIST_FIRST(&allproc);
1687 				mmmbrains = false;
1688 			}
1689 			if (p == NULL)
1690 				break;
1691 		}
1692 		next = LIST_NEXT(p, p_list);
1693 		if ((p->p_flag & PK_MARKER) != 0)
1694 			continue;
1695 
1696 		/*
1697 		 * Skip embryonic processes.
1698 		 */
1699 		if (p->p_stat == SIDL)
1700 			continue;
1701 
1702 		mutex_enter(p->p_lock);
1703 		error = kauth_authorize_process(l->l_cred,
1704 		    KAUTH_PROCESS_CANSEE, p,
1705 		    KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_EPROC), NULL, NULL);
1706 		if (error != 0) {
1707 			mutex_exit(p->p_lock);
1708 			continue;
1709 		}
1710 
1711 		/*
1712 		 * Hande all the operations in one switch on the cost of
1713 		 * algorithm complexity is on purpose. The win splitting this
1714 		 * function into several similar copies makes maintenance burden
1715 		 * burden, code grow and boost is neglible in practical systems.
1716 		 */
1717 		switch (op) {
1718 		case KERN_PROC_PID:
1719 			match = (p->p_pid == (pid_t)arg);
1720 			break;
1721 
1722 		case KERN_PROC_PGRP:
1723 			match = (p->p_pgrp->pg_id == (pid_t)arg);
1724 			break;
1725 
1726 		case KERN_PROC_SESSION:
1727 			match = (p->p_session->s_sid == (pid_t)arg);
1728 			break;
1729 
1730 		case KERN_PROC_TTY:
1731 			match = true;
1732 			if (arg == (int) KERN_PROC_TTY_REVOKE) {
1733 				if ((p->p_lflag & PL_CONTROLT) == 0 ||
1734 				    p->p_session->s_ttyp == NULL ||
1735 				    p->p_session->s_ttyvp != NULL) {
1736 				    	match = false;
1737 				}
1738 			} else if ((p->p_lflag & PL_CONTROLT) == 0 ||
1739 			    p->p_session->s_ttyp == NULL) {
1740 				if ((dev_t)arg != KERN_PROC_TTY_NODEV) {
1741 					match = false;
1742 				}
1743 			} else if (p->p_session->s_ttyp->t_dev != (dev_t)arg) {
1744 				match = false;
1745 			}
1746 			break;
1747 
1748 		case KERN_PROC_UID:
1749 			match = (kauth_cred_geteuid(p->p_cred) == (uid_t)arg);
1750 			break;
1751 
1752 		case KERN_PROC_RUID:
1753 			match = (kauth_cred_getuid(p->p_cred) == (uid_t)arg);
1754 			break;
1755 
1756 		case KERN_PROC_GID:
1757 			match = (kauth_cred_getegid(p->p_cred) == (uid_t)arg);
1758 			break;
1759 
1760 		case KERN_PROC_RGID:
1761 			match = (kauth_cred_getgid(p->p_cred) == (uid_t)arg);
1762 			break;
1763 
1764 		case KERN_PROC_ALL:
1765 			match = true;
1766 			/* allow everything */
1767 			break;
1768 
1769 		default:
1770 			error = EINVAL;
1771 			mutex_exit(p->p_lock);
1772 			goto cleanup;
1773 		}
1774 		if (!match) {
1775 			mutex_exit(p->p_lock);
1776 			continue;
1777 		}
1778 
1779 		/*
1780 		 * Grab a hold on the process.
1781 		 */
1782 		if (mmmbrains) {
1783 			zombie = true;
1784 		} else {
1785 			zombie = !rw_tryenter(&p->p_reflock, RW_READER);
1786 		}
1787 		if (zombie) {
1788 			LIST_INSERT_AFTER(p, marker, p_list);
1789 		}
1790 
1791 		if (buflen >= elem_size &&
1792 		    (type == KERN_PROC || elem_count > 0)) {
1793 			if (type == KERN_PROC) {
1794 				kbuf->kproc.kp_proc = *p;
1795 				fill_eproc(p, &kbuf->kproc.kp_eproc, zombie);
1796 			} else {
1797 				fill_kproc2(p, &kbuf->kproc2, zombie);
1798 				elem_count--;
1799 			}
1800 			mutex_exit(p->p_lock);
1801 			mutex_exit(proc_lock);
1802 			/*
1803 			 * Copy out elem_size, but not larger than kelem_size
1804 			 */
1805 			error = sysctl_copyout(l, kbuf, dp,
1806 			    uimin(kelem_size, elem_size));
1807 			mutex_enter(proc_lock);
1808 			if (error) {
1809 				goto bah;
1810 			}
1811 			dp += elem_size;
1812 			buflen -= elem_size;
1813 		} else {
1814 			mutex_exit(p->p_lock);
1815 		}
1816 		needed += elem_size;
1817 
1818 		/*
1819 		 * Release reference to process.
1820 		 */
1821 	 	if (zombie) {
1822 			next = LIST_NEXT(marker, p_list);
1823  			LIST_REMOVE(marker, p_list);
1824 		} else {
1825 			rw_exit(&p->p_reflock);
1826 			next = LIST_NEXT(p, p_list);
1827 		}
1828 
1829 		/*
1830 		 * Short-circuit break quickly!
1831 		 */
1832 		if (op == KERN_PROC_PID)
1833                 	break;
1834 	}
1835 	mutex_exit(proc_lock);
1836 
1837 	if (where != NULL) {
1838 		*oldlenp = dp - where;
1839 		if (needed > *oldlenp) {
1840 			error = ENOMEM;
1841 			goto out;
1842 		}
1843 	} else {
1844 		needed += KERN_PROCSLOP;
1845 		*oldlenp = needed;
1846 	}
1847 	kmem_free(kbuf, sizeof(*kbuf));
1848 	kmem_free(marker, sizeof(*marker));
1849 	sysctl_relock();
1850 	return 0;
1851  bah:
1852  	if (zombie)
1853  		LIST_REMOVE(marker, p_list);
1854 	else
1855 		rw_exit(&p->p_reflock);
1856  cleanup:
1857 	mutex_exit(proc_lock);
1858  out:
1859 	kmem_free(kbuf, sizeof(*kbuf));
1860 	kmem_free(marker, sizeof(*marker));
1861 	sysctl_relock();
1862 	return error;
1863 }
1864 
1865 int
1866 copyin_psstrings(struct proc *p, struct ps_strings *arginfo)
1867 {
1868 
1869 #ifdef COMPAT_NETBSD32
1870 	if (p->p_flag & PK_32) {
1871 		struct ps_strings32 arginfo32;
1872 
1873 		int error = copyin_proc(p, (void *)p->p_psstrp, &arginfo32,
1874 		    sizeof(arginfo32));
1875 		if (error)
1876 			return error;
1877 		arginfo->ps_argvstr = (void *)(uintptr_t)arginfo32.ps_argvstr;
1878 		arginfo->ps_nargvstr = arginfo32.ps_nargvstr;
1879 		arginfo->ps_envstr = (void *)(uintptr_t)arginfo32.ps_envstr;
1880 		arginfo->ps_nenvstr = arginfo32.ps_nenvstr;
1881 		return 0;
1882 	}
1883 #endif
1884 	return copyin_proc(p, (void *)p->p_psstrp, arginfo, sizeof(*arginfo));
1885 }
1886 
1887 static int
1888 copy_procargs_sysctl_cb(void *cookie_, const void *src, size_t off, size_t len)
1889 {
1890 	void **cookie = cookie_;
1891 	struct lwp *l = cookie[0];
1892 	char *dst = cookie[1];
1893 
1894 	return sysctl_copyout(l, src, dst + off, len);
1895 }
1896 
1897 /*
1898  * sysctl helper routine for kern.proc_args pseudo-subtree.
1899  */
1900 static int
1901 sysctl_kern_proc_args(SYSCTLFN_ARGS)
1902 {
1903 	struct ps_strings pss;
1904 	struct proc *p;
1905 	pid_t pid;
1906 	int type, error;
1907 	void *cookie[2];
1908 
1909 	if (namelen == 1 && name[0] == CTL_QUERY)
1910 		return (sysctl_query(SYSCTLFN_CALL(rnode)));
1911 
1912 	if (newp != NULL || namelen != 2)
1913 		return (EINVAL);
1914 	pid = name[0];
1915 	type = name[1];
1916 
1917 	switch (type) {
1918 	case KERN_PROC_PATHNAME:
1919 		sysctl_unlock();
1920 		error = fill_pathname(l, pid, oldp, oldlenp);
1921 		sysctl_relock();
1922 		return error;
1923 
1924 	case KERN_PROC_ARGV:
1925 	case KERN_PROC_NARGV:
1926 	case KERN_PROC_ENV:
1927 	case KERN_PROC_NENV:
1928 		/* ok */
1929 		break;
1930 	default:
1931 		return (EINVAL);
1932 	}
1933 
1934 	sysctl_unlock();
1935 
1936 	/* check pid */
1937 	mutex_enter(proc_lock);
1938 	if ((p = proc_find(pid)) == NULL) {
1939 		error = EINVAL;
1940 		goto out_locked;
1941 	}
1942 	mutex_enter(p->p_lock);
1943 
1944 	/* Check permission. */
1945 	if (type == KERN_PROC_ARGV || type == KERN_PROC_NARGV)
1946 		error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_CANSEE,
1947 		    p, KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ARGS), NULL, NULL);
1948 	else if (type == KERN_PROC_ENV || type == KERN_PROC_NENV)
1949 		error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_CANSEE,
1950 		    p, KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ENV), NULL, NULL);
1951 	else
1952 		error = EINVAL; /* XXXGCC */
1953 	if (error) {
1954 		mutex_exit(p->p_lock);
1955 		goto out_locked;
1956 	}
1957 
1958 	if (oldp == NULL) {
1959 		if (type == KERN_PROC_NARGV || type == KERN_PROC_NENV)
1960 			*oldlenp = sizeof (int);
1961 		else
1962 			*oldlenp = ARG_MAX;	/* XXX XXX XXX */
1963 		error = 0;
1964 		mutex_exit(p->p_lock);
1965 		goto out_locked;
1966 	}
1967 
1968 	/*
1969 	 * Zombies don't have a stack, so we can't read their psstrings.
1970 	 * System processes also don't have a user stack.
1971 	 */
1972 	if (P_ZOMBIE(p) || (p->p_flag & PK_SYSTEM) != 0) {
1973 		error = EINVAL;
1974 		mutex_exit(p->p_lock);
1975 		goto out_locked;
1976 	}
1977 
1978 	error = rw_tryenter(&p->p_reflock, RW_READER) ? 0 : EBUSY;
1979 	mutex_exit(p->p_lock);
1980 	if (error) {
1981 		goto out_locked;
1982 	}
1983 	mutex_exit(proc_lock);
1984 
1985 	if (type == KERN_PROC_NARGV || type == KERN_PROC_NENV) {
1986 		int value;
1987 		if ((error = copyin_psstrings(p, &pss)) == 0) {
1988 			if (type == KERN_PROC_NARGV)
1989 				value = pss.ps_nargvstr;
1990 			else
1991 				value = pss.ps_nenvstr;
1992 			error = sysctl_copyout(l, &value, oldp, sizeof(value));
1993 			*oldlenp = sizeof(value);
1994 		}
1995 	} else {
1996 		cookie[0] = l;
1997 		cookie[1] = oldp;
1998 		error = copy_procargs(p, type, oldlenp,
1999 		    copy_procargs_sysctl_cb, cookie);
2000 	}
2001 	rw_exit(&p->p_reflock);
2002 	sysctl_relock();
2003 	return error;
2004 
2005 out_locked:
2006 	mutex_exit(proc_lock);
2007 	sysctl_relock();
2008 	return error;
2009 }
2010 
2011 int
2012 copy_procargs(struct proc *p, int oid, size_t *limit,
2013     int (*cb)(void *, const void *, size_t, size_t), void *cookie)
2014 {
2015 	struct ps_strings pss;
2016 	size_t len, i, loaded, entry_len;
2017 	struct uio auio;
2018 	struct iovec aiov;
2019 	int error, argvlen;
2020 	char *arg;
2021 	char **argv;
2022 	vaddr_t user_argv;
2023 	struct vmspace *vmspace;
2024 
2025 	/*
2026 	 * Allocate a temporary buffer to hold the argument vector and
2027 	 * the arguments themselve.
2028 	 */
2029 	arg = kmem_alloc(PAGE_SIZE, KM_SLEEP);
2030 	argv = kmem_alloc(PAGE_SIZE, KM_SLEEP);
2031 
2032 	/*
2033 	 * Lock the process down in memory.
2034 	 */
2035 	vmspace = p->p_vmspace;
2036 	uvmspace_addref(vmspace);
2037 
2038 	/*
2039 	 * Read in the ps_strings structure.
2040 	 */
2041 	if ((error = copyin_psstrings(p, &pss)) != 0)
2042 		goto done;
2043 
2044 	/*
2045 	 * Now read the address of the argument vector.
2046 	 */
2047 	switch (oid) {
2048 	case KERN_PROC_ARGV:
2049 		user_argv = (uintptr_t)pss.ps_argvstr;
2050 		argvlen = pss.ps_nargvstr;
2051 		break;
2052 	case KERN_PROC_ENV:
2053 		user_argv = (uintptr_t)pss.ps_envstr;
2054 		argvlen = pss.ps_nenvstr;
2055 		break;
2056 	default:
2057 		error = EINVAL;
2058 		goto done;
2059 	}
2060 
2061 	if (argvlen < 0) {
2062 		error = EIO;
2063 		goto done;
2064 	}
2065 
2066 
2067 	/*
2068 	 * Now copy each string.
2069 	 */
2070 	len = 0; /* bytes written to user buffer */
2071 	loaded = 0; /* bytes from argv already processed */
2072 	i = 0; /* To make compiler happy */
2073 	entry_len = PROC_PTRSZ(p);
2074 
2075 	for (; argvlen; --argvlen) {
2076 		int finished = 0;
2077 		vaddr_t base;
2078 		size_t xlen;
2079 		int j;
2080 
2081 		if (loaded == 0) {
2082 			size_t rem = entry_len * argvlen;
2083 			loaded = MIN(rem, PAGE_SIZE);
2084 			error = copyin_vmspace(vmspace,
2085 			    (const void *)user_argv, argv, loaded);
2086 			if (error)
2087 				break;
2088 			user_argv += loaded;
2089 			i = 0;
2090 		}
2091 
2092 #ifdef COMPAT_NETBSD32
2093 		if (p->p_flag & PK_32) {
2094 			netbsd32_charp *argv32;
2095 
2096 			argv32 = (netbsd32_charp *)argv;
2097 			base = (vaddr_t)NETBSD32PTR64(argv32[i++]);
2098 		} else
2099 #endif
2100 			base = (vaddr_t)argv[i++];
2101 		loaded -= entry_len;
2102 
2103 		/*
2104 		 * The program has messed around with its arguments,
2105 		 * possibly deleting some, and replacing them with
2106 		 * NULL's. Treat this as the last argument and not
2107 		 * a failure.
2108 		 */
2109 		if (base == 0)
2110 			break;
2111 
2112 		while (!finished) {
2113 			xlen = PAGE_SIZE - (base & PAGE_MASK);
2114 
2115 			aiov.iov_base = arg;
2116 			aiov.iov_len = PAGE_SIZE;
2117 			auio.uio_iov = &aiov;
2118 			auio.uio_iovcnt = 1;
2119 			auio.uio_offset = base;
2120 			auio.uio_resid = xlen;
2121 			auio.uio_rw = UIO_READ;
2122 			UIO_SETUP_SYSSPACE(&auio);
2123 			error = uvm_io(&vmspace->vm_map, &auio, 0);
2124 			if (error)
2125 				goto done;
2126 
2127 			/* Look for the end of the string */
2128 			for (j = 0; j < xlen; j++) {
2129 				if (arg[j] == '\0') {
2130 					xlen = j + 1;
2131 					finished = 1;
2132 					break;
2133 				}
2134 			}
2135 
2136 			/* Check for user buffer overflow */
2137 			if (len + xlen > *limit) {
2138 				finished = 1;
2139 				if (len > *limit)
2140 					xlen = 0;
2141 				else
2142 					xlen = *limit - len;
2143 			}
2144 
2145 			/* Copyout the page */
2146 			error = (*cb)(cookie, arg, len, xlen);
2147 			if (error)
2148 				goto done;
2149 
2150 			len += xlen;
2151 			base += xlen;
2152 		}
2153 	}
2154 	*limit = len;
2155 
2156 done:
2157 	kmem_free(argv, PAGE_SIZE);
2158 	kmem_free(arg, PAGE_SIZE);
2159 	uvmspace_free(vmspace);
2160 	return error;
2161 }
2162 
2163 #define SET_KERN_ADDR(dst, src, allow)	\
2164 	do {				\
2165 		if (allow)		\
2166 			dst = src;	\
2167 	} while (0);
2168 
2169 /*
2170  * Fill in an eproc structure for the specified process.
2171  */
2172 void
2173 fill_eproc(struct proc *p, struct eproc *ep, bool zombie)
2174 {
2175 	bool allowaddr;
2176 	struct tty *tp;
2177 	struct lwp *l;
2178 	int error;
2179 
2180 	KASSERT(mutex_owned(proc_lock));
2181 	KASSERT(mutex_owned(p->p_lock));
2182 
2183 	memset(ep, 0, sizeof(*ep));
2184 
2185 	/* If not privileged, don't expose kernel addresses. */
2186 	error = kauth_authorize_process(kauth_cred_get(), KAUTH_PROCESS_CANSEE,
2187 	    curproc, KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_KPTR), NULL, NULL);
2188 	allowaddr = (error == 0);
2189 
2190 	SET_KERN_ADDR(ep->e_paddr, p, allowaddr);
2191 	SET_KERN_ADDR(ep->e_sess, p->p_session, allowaddr);
2192 	if (p->p_cred) {
2193 		kauth_cred_topcred(p->p_cred, &ep->e_pcred);
2194 		kauth_cred_toucred(p->p_cred, &ep->e_ucred);
2195 	}
2196 	if (p->p_stat != SIDL && !P_ZOMBIE(p) && !zombie) {
2197 		struct vmspace *vm = p->p_vmspace;
2198 
2199 		ep->e_vm.vm_rssize = vm_resident_count(vm);
2200 		ep->e_vm.vm_tsize = vm->vm_tsize;
2201 		ep->e_vm.vm_dsize = vm->vm_dsize;
2202 		ep->e_vm.vm_ssize = vm->vm_ssize;
2203 		ep->e_vm.vm_map.size = vm->vm_map.size;
2204 
2205 		/* Pick the primary (first) LWP */
2206 		l = proc_active_lwp(p);
2207 		KASSERT(l != NULL);
2208 		lwp_lock(l);
2209 		if (l->l_wchan)
2210 			strncpy(ep->e_wmesg, l->l_wmesg, WMESGLEN);
2211 		lwp_unlock(l);
2212 	}
2213 	ep->e_ppid = p->p_ppid;
2214 	if (p->p_pgrp && p->p_session) {
2215 		ep->e_pgid = p->p_pgrp->pg_id;
2216 		ep->e_jobc = p->p_pgrp->pg_jobc;
2217 		ep->e_sid = p->p_session->s_sid;
2218 		if ((p->p_lflag & PL_CONTROLT) &&
2219 		    (tp = p->p_session->s_ttyp)) {
2220 			ep->e_tdev = tp->t_dev;
2221 			ep->e_tpgid = tp->t_pgrp ? tp->t_pgrp->pg_id : NO_PGID;
2222 			SET_KERN_ADDR(ep->e_tsess, tp->t_session, allowaddr);
2223 		} else
2224 			ep->e_tdev = (uint32_t)NODEV;
2225 		ep->e_flag = p->p_session->s_ttyvp ? EPROC_CTTY : 0;
2226 		if (SESS_LEADER(p))
2227 			ep->e_flag |= EPROC_SLEADER;
2228 		strncpy(ep->e_login, p->p_session->s_login, MAXLOGNAME);
2229 	}
2230 	ep->e_xsize = ep->e_xrssize = 0;
2231 	ep->e_xccount = ep->e_xswrss = 0;
2232 }
2233 
2234 /*
2235  * Fill in a kinfo_proc2 structure for the specified process.
2236  */
2237 void
2238 fill_kproc2(struct proc *p, struct kinfo_proc2 *ki, bool zombie)
2239 {
2240 	struct tty *tp;
2241 	struct lwp *l, *l2;
2242 	struct timeval ut, st, rt;
2243 	sigset_t ss1, ss2;
2244 	struct rusage ru;
2245 	struct vmspace *vm;
2246 	bool allowaddr;
2247 	int error;
2248 
2249 	KASSERT(mutex_owned(proc_lock));
2250 	KASSERT(mutex_owned(p->p_lock));
2251 
2252 	/* If not privileged, don't expose kernel addresses. */
2253 	error = kauth_authorize_process(kauth_cred_get(), KAUTH_PROCESS_CANSEE,
2254 	    curproc, KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_KPTR), NULL, NULL);
2255 	allowaddr = (error == 0);
2256 
2257 	sigemptyset(&ss1);
2258 	sigemptyset(&ss2);
2259 	memset(ki, 0, sizeof(*ki));
2260 
2261 	SET_KERN_ADDR(ki->p_paddr, PTRTOUINT64(p), allowaddr);
2262 	SET_KERN_ADDR(ki->p_fd, PTRTOUINT64(p->p_fd), allowaddr);
2263 	SET_KERN_ADDR(ki->p_cwdi, PTRTOUINT64(p->p_cwdi), allowaddr);
2264 	SET_KERN_ADDR(ki->p_stats, PTRTOUINT64(p->p_stats), allowaddr);
2265 	SET_KERN_ADDR(ki->p_limit, PTRTOUINT64(p->p_limit), allowaddr);
2266 	SET_KERN_ADDR(ki->p_vmspace, PTRTOUINT64(p->p_vmspace), allowaddr);
2267 	SET_KERN_ADDR(ki->p_sigacts, PTRTOUINT64(p->p_sigacts), allowaddr);
2268 	SET_KERN_ADDR(ki->p_sess, PTRTOUINT64(p->p_session), allowaddr);
2269 	ki->p_tsess = 0;	/* may be changed if controlling tty below */
2270 	SET_KERN_ADDR(ki->p_ru, PTRTOUINT64(&p->p_stats->p_ru), allowaddr);
2271 	ki->p_eflag = 0;
2272 	ki->p_exitsig = p->p_exitsig;
2273 	ki->p_flag = L_INMEM;   /* Process never swapped out */
2274 	ki->p_flag |= sysctl_map_flags(sysctl_flagmap, p->p_flag);
2275 	ki->p_flag |= sysctl_map_flags(sysctl_sflagmap, p->p_sflag);
2276 	ki->p_flag |= sysctl_map_flags(sysctl_slflagmap, p->p_slflag);
2277 	ki->p_flag |= sysctl_map_flags(sysctl_lflagmap, p->p_lflag);
2278 	ki->p_flag |= sysctl_map_flags(sysctl_stflagmap, p->p_stflag);
2279 	ki->p_pid = p->p_pid;
2280 	ki->p_ppid = p->p_ppid;
2281 	ki->p_uid = kauth_cred_geteuid(p->p_cred);
2282 	ki->p_ruid = kauth_cred_getuid(p->p_cred);
2283 	ki->p_gid = kauth_cred_getegid(p->p_cred);
2284 	ki->p_rgid = kauth_cred_getgid(p->p_cred);
2285 	ki->p_svuid = kauth_cred_getsvuid(p->p_cred);
2286 	ki->p_svgid = kauth_cred_getsvgid(p->p_cred);
2287 	ki->p_ngroups = kauth_cred_ngroups(p->p_cred);
2288 	kauth_cred_getgroups(p->p_cred, ki->p_groups,
2289 	    uimin(ki->p_ngroups, sizeof(ki->p_groups) / sizeof(ki->p_groups[0])),
2290 	    UIO_SYSSPACE);
2291 
2292 	ki->p_uticks = p->p_uticks;
2293 	ki->p_sticks = p->p_sticks;
2294 	ki->p_iticks = p->p_iticks;
2295 	ki->p_tpgid = NO_PGID;	/* may be changed if controlling tty below */
2296 	SET_KERN_ADDR(ki->p_tracep, PTRTOUINT64(p->p_tracep), allowaddr);
2297 	ki->p_traceflag = p->p_traceflag;
2298 
2299 	memcpy(&ki->p_sigignore, &p->p_sigctx.ps_sigignore,sizeof(ki_sigset_t));
2300 	memcpy(&ki->p_sigcatch, &p->p_sigctx.ps_sigcatch, sizeof(ki_sigset_t));
2301 
2302 	ki->p_cpticks = 0;
2303 	ki->p_pctcpu = p->p_pctcpu;
2304 	ki->p_estcpu = 0;
2305 	ki->p_stat = p->p_stat; /* Will likely be overridden by LWP status */
2306 	ki->p_realstat = p->p_stat;
2307 	ki->p_nice = p->p_nice;
2308 	ki->p_xstat = P_WAITSTATUS(p);
2309 	ki->p_acflag = p->p_acflag;
2310 
2311 	strncpy(ki->p_comm, p->p_comm,
2312 	    uimin(sizeof(ki->p_comm), sizeof(p->p_comm)));
2313 	strncpy(ki->p_ename, p->p_emul->e_name, sizeof(ki->p_ename));
2314 
2315 	ki->p_nlwps = p->p_nlwps;
2316 	ki->p_realflag = ki->p_flag;
2317 
2318 	if (p->p_stat != SIDL && !P_ZOMBIE(p) && !zombie) {
2319 		vm = p->p_vmspace;
2320 		ki->p_vm_rssize = vm_resident_count(vm);
2321 		ki->p_vm_tsize = vm->vm_tsize;
2322 		ki->p_vm_dsize = vm->vm_dsize;
2323 		ki->p_vm_ssize = vm->vm_ssize;
2324 		ki->p_vm_vsize = atop(vm->vm_map.size);
2325 		/*
2326 		 * Since the stack is initially mapped mostly with
2327 		 * PROT_NONE and grown as needed, adjust the "mapped size"
2328 		 * to skip the unused stack portion.
2329 		 */
2330 		ki->p_vm_msize =
2331 		    atop(vm->vm_map.size) - vm->vm_issize + vm->vm_ssize;
2332 
2333 		/* Pick the primary (first) LWP */
2334 		l = proc_active_lwp(p);
2335 		KASSERT(l != NULL);
2336 		lwp_lock(l);
2337 		ki->p_nrlwps = p->p_nrlwps;
2338 		ki->p_forw = 0;
2339 		ki->p_back = 0;
2340 		SET_KERN_ADDR(ki->p_addr, PTRTOUINT64(l->l_addr), allowaddr);
2341 		ki->p_stat = l->l_stat;
2342 		ki->p_flag |= sysctl_map_flags(sysctl_lwpflagmap, l->l_flag);
2343 		ki->p_swtime = l->l_swtime;
2344 		ki->p_slptime = l->l_slptime;
2345 		if (l->l_stat == LSONPROC)
2346 			ki->p_schedflags = l->l_cpu->ci_schedstate.spc_flags;
2347 		else
2348 			ki->p_schedflags = 0;
2349 		ki->p_priority = lwp_eprio(l);
2350 		ki->p_usrpri = l->l_priority;
2351 		if (l->l_wchan)
2352 			strncpy(ki->p_wmesg, l->l_wmesg, sizeof(ki->p_wmesg));
2353 		SET_KERN_ADDR(ki->p_wchan, PTRTOUINT64(l->l_wchan), allowaddr);
2354 		ki->p_cpuid = cpu_index(l->l_cpu);
2355 		lwp_unlock(l);
2356 		LIST_FOREACH(l, &p->p_lwps, l_sibling) {
2357 			/* This is hardly correct, but... */
2358 			sigplusset(&l->l_sigpend.sp_set, &ss1);
2359 			sigplusset(&l->l_sigmask, &ss2);
2360 			ki->p_cpticks += l->l_cpticks;
2361 			ki->p_pctcpu += l->l_pctcpu;
2362 			ki->p_estcpu += l->l_estcpu;
2363 		}
2364 	}
2365 	sigplusset(&p->p_sigpend.sp_set, &ss2);
2366 	memcpy(&ki->p_siglist, &ss1, sizeof(ki_sigset_t));
2367 	memcpy(&ki->p_sigmask, &ss2, sizeof(ki_sigset_t));
2368 
2369 	if (p->p_session != NULL) {
2370 		ki->p_sid = p->p_session->s_sid;
2371 		ki->p__pgid = p->p_pgrp->pg_id;
2372 		if (p->p_session->s_ttyvp)
2373 			ki->p_eflag |= EPROC_CTTY;
2374 		if (SESS_LEADER(p))
2375 			ki->p_eflag |= EPROC_SLEADER;
2376 		strncpy(ki->p_login, p->p_session->s_login,
2377 		    uimin(sizeof ki->p_login - 1, sizeof p->p_session->s_login));
2378 		ki->p_jobc = p->p_pgrp->pg_jobc;
2379 		if ((p->p_lflag & PL_CONTROLT) && (tp = p->p_session->s_ttyp)) {
2380 			ki->p_tdev = tp->t_dev;
2381 			ki->p_tpgid = tp->t_pgrp ? tp->t_pgrp->pg_id : NO_PGID;
2382 			SET_KERN_ADDR(ki->p_tsess, PTRTOUINT64(tp->t_session),
2383 			    allowaddr);
2384 		} else {
2385 			ki->p_tdev = (int32_t)NODEV;
2386 		}
2387 	}
2388 
2389 	if (!P_ZOMBIE(p) && !zombie) {
2390 		ki->p_uvalid = 1;
2391 		ki->p_ustart_sec = p->p_stats->p_start.tv_sec;
2392 		ki->p_ustart_usec = p->p_stats->p_start.tv_usec;
2393 
2394 		calcru(p, &ut, &st, NULL, &rt);
2395 		ki->p_rtime_sec = rt.tv_sec;
2396 		ki->p_rtime_usec = rt.tv_usec;
2397 		ki->p_uutime_sec = ut.tv_sec;
2398 		ki->p_uutime_usec = ut.tv_usec;
2399 		ki->p_ustime_sec = st.tv_sec;
2400 		ki->p_ustime_usec = st.tv_usec;
2401 
2402 		memcpy(&ru, &p->p_stats->p_ru, sizeof(ru));
2403 		ki->p_uru_nvcsw = 0;
2404 		ki->p_uru_nivcsw = 0;
2405 		LIST_FOREACH(l2, &p->p_lwps, l_sibling) {
2406 			ki->p_uru_nvcsw += (l2->l_ncsw - l2->l_nivcsw);
2407 			ki->p_uru_nivcsw += l2->l_nivcsw;
2408 			ruadd(&ru, &l2->l_ru);
2409 		}
2410 		ki->p_uru_maxrss = ru.ru_maxrss;
2411 		ki->p_uru_ixrss = ru.ru_ixrss;
2412 		ki->p_uru_idrss = ru.ru_idrss;
2413 		ki->p_uru_isrss = ru.ru_isrss;
2414 		ki->p_uru_minflt = ru.ru_minflt;
2415 		ki->p_uru_majflt = ru.ru_majflt;
2416 		ki->p_uru_nswap = ru.ru_nswap;
2417 		ki->p_uru_inblock = ru.ru_inblock;
2418 		ki->p_uru_oublock = ru.ru_oublock;
2419 		ki->p_uru_msgsnd = ru.ru_msgsnd;
2420 		ki->p_uru_msgrcv = ru.ru_msgrcv;
2421 		ki->p_uru_nsignals = ru.ru_nsignals;
2422 
2423 		timeradd(&p->p_stats->p_cru.ru_utime,
2424 			 &p->p_stats->p_cru.ru_stime, &ut);
2425 		ki->p_uctime_sec = ut.tv_sec;
2426 		ki->p_uctime_usec = ut.tv_usec;
2427 	}
2428 }
2429 
2430 
2431 int
2432 proc_find_locked(struct lwp *l, struct proc **p, pid_t pid)
2433 {
2434 	int error;
2435 
2436 	mutex_enter(proc_lock);
2437 	if (pid == -1)
2438 		*p = l->l_proc;
2439 	else
2440 		*p = proc_find(pid);
2441 
2442 	if (*p == NULL) {
2443 		if (pid != -1)
2444 			mutex_exit(proc_lock);
2445 		return ESRCH;
2446 	}
2447 	if (pid != -1)
2448 		mutex_enter((*p)->p_lock);
2449 	mutex_exit(proc_lock);
2450 
2451 	error = kauth_authorize_process(l->l_cred,
2452 	    KAUTH_PROCESS_CANSEE, *p,
2453 	    KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ENTRY), NULL, NULL);
2454 	if (error) {
2455 		if (pid != -1)
2456 			mutex_exit((*p)->p_lock);
2457 	}
2458 	return error;
2459 }
2460 
2461 static int
2462 fill_pathname(struct lwp *l, pid_t pid, void *oldp, size_t *oldlenp)
2463 {
2464 	int error;
2465 	struct proc *p;
2466 
2467 	if ((error = proc_find_locked(l, &p, pid)) != 0)
2468 		return error;
2469 
2470 	if (p->p_path == NULL) {
2471 		if (pid != -1)
2472 			mutex_exit(p->p_lock);
2473 		return ENOENT;
2474 	}
2475 
2476 	size_t len = strlen(p->p_path) + 1;
2477 	if (oldp != NULL) {
2478 		error = sysctl_copyout(l, p->p_path, oldp, *oldlenp);
2479 		if (error == 0 && *oldlenp < len)
2480 			error = ENOSPC;
2481 	}
2482 	*oldlenp = len;
2483 	if (pid != -1)
2484 		mutex_exit(p->p_lock);
2485 	return error;
2486 }
2487 
2488 int
2489 proc_getauxv(struct proc *p, void **buf, size_t *len)
2490 {
2491 	struct ps_strings pss;
2492 	int error;
2493 	void *uauxv, *kauxv;
2494 	size_t size;
2495 
2496 	if ((error = copyin_psstrings(p, &pss)) != 0)
2497 		return error;
2498 	if (pss.ps_envstr == NULL)
2499 		return EIO;
2500 
2501 	size = p->p_execsw->es_arglen;
2502 	if (size == 0)
2503 		return EIO;
2504 
2505 	size_t ptrsz = PROC_PTRSZ(p);
2506 	uauxv = (void *)((char *)pss.ps_envstr + (pss.ps_nenvstr + 1) * ptrsz);
2507 
2508 	kauxv = kmem_alloc(size, KM_SLEEP);
2509 
2510 	error = copyin_proc(p, uauxv, kauxv, size);
2511 	if (error) {
2512 		kmem_free(kauxv, size);
2513 		return error;
2514 	}
2515 
2516 	*buf = kauxv;
2517 	*len = size;
2518 
2519 	return 0;
2520 }
2521