xref: /netbsd-src/sys/miscfs/procfs/procfs_subr.c (revision 88fcb00c0357f2d7c1774f86a352637bfda96184)
1 /*	$NetBSD: procfs_subr.c,v 1.99 2011/06/12 03:35:58 rmind Exp $	*/
2 
3 /*-
4  * Copyright (c) 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 Andrew Doran.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * Copyright (c) 1993
34  *	The Regents of the University of California.  All rights reserved.
35  *
36  * This code is derived from software contributed to Berkeley by
37  * Jan-Simon Pendry.
38  *
39  * Redistribution and use in source and binary forms, with or without
40  * modification, are permitted provided that the following conditions
41  * are met:
42  * 1. Redistributions of source code must retain the above copyright
43  *    notice, this list of conditions and the following disclaimer.
44  * 2. Redistributions in binary form must reproduce the above copyright
45  *    notice, this list of conditions and the following disclaimer in the
46  *    documentation and/or other materials provided with the distribution.
47  * 3. Neither the name of the University nor the names of its contributors
48  *    may be used to endorse or promote products derived from this software
49  *    without specific prior written permission.
50  *
51  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
61  * SUCH DAMAGE.
62  *
63  *	@(#)procfs_subr.c	8.6 (Berkeley) 5/14/95
64  */
65 
66 /*
67  * Copyright (c) 1994 Christopher G. Demetriou.  All rights reserved.
68  * Copyright (c) 1993 Jan-Simon Pendry
69  *
70  * This code is derived from software contributed to Berkeley by
71  * Jan-Simon Pendry.
72  *
73  * Redistribution and use in source and binary forms, with or without
74  * modification, are permitted provided that the following conditions
75  * are met:
76  * 1. Redistributions of source code must retain the above copyright
77  *    notice, this list of conditions and the following disclaimer.
78  * 2. Redistributions in binary form must reproduce the above copyright
79  *    notice, this list of conditions and the following disclaimer in the
80  *    documentation and/or other materials provided with the distribution.
81  * 3. All advertising materials mentioning features or use of this software
82  *    must display the following acknowledgement:
83  *	This product includes software developed by the University of
84  *	California, Berkeley and its contributors.
85  * 4. Neither the name of the University nor the names of its contributors
86  *    may be used to endorse or promote products derived from this software
87  *    without specific prior written permission.
88  *
89  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
90  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
91  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
92  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
93  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
94  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
95  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
96  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
97  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
98  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
99  * SUCH DAMAGE.
100  *
101  *	@(#)procfs_subr.c	8.6 (Berkeley) 5/14/95
102  */
103 
104 #include <sys/cdefs.h>
105 __KERNEL_RCSID(0, "$NetBSD: procfs_subr.c,v 1.99 2011/06/12 03:35:58 rmind Exp $");
106 
107 #include <sys/param.h>
108 #include <sys/systm.h>
109 #include <sys/time.h>
110 #include <sys/kernel.h>
111 #include <sys/proc.h>
112 #include <sys/vnode.h>
113 #include <sys/malloc.h>
114 #include <sys/stat.h>
115 #include <sys/file.h>
116 #include <sys/filedesc.h>
117 #include <sys/kauth.h>
118 
119 #include <miscfs/procfs/procfs.h>
120 
121 void procfs_hashins(struct pfsnode *);
122 void procfs_hashrem(struct pfsnode *);
123 struct vnode *procfs_hashget(pid_t, pfstype, int, struct mount *, int);
124 
125 LIST_HEAD(pfs_hashhead, pfsnode) *pfs_hashtbl;
126 u_long	pfs_ihash;	/* size of hash table - 1 */
127 #define PFSPIDHASH(pid)	((pid) & pfs_ihash)
128 
129 kmutex_t pfs_hashlock;
130 kmutex_t pfs_ihash_lock;
131 
132 #define	ISSET(t, f)	((t) & (f))
133 
134 /*
135  * allocate a pfsnode/vnode pair.  the vnode is
136  * referenced, and locked.
137  *
138  * the pid, pfs_type, and mount point uniquely
139  * identify a pfsnode.  the mount point is needed
140  * because someone might mount this filesystem
141  * twice.
142  *
143  * all pfsnodes are maintained on a singly-linked
144  * list.  new nodes are only allocated when they cannot
145  * be found on this list.  entries on the list are
146  * removed when the vfs reclaim entry is called.
147  *
148  * a single lock is kept for the entire list.  this is
149  * needed because the getnewvnode() function can block
150  * waiting for a vnode to become free, in which case there
151  * may be more than one process trying to get the same
152  * vnode.  this lock is only taken if we are going to
153  * call getnewvnode, since the kernel itself is single-threaded.
154  *
155  * if an entry is found on the list, then call vget() to
156  * take a reference.  this is done because there may be
157  * zero references to it and so it needs to removed from
158  * the vnode free list.
159  */
160 int
161 procfs_allocvp(struct mount *mp, struct vnode **vpp, pid_t pid,
162     pfstype pfs_type, int fd, struct proc *p)
163 {
164 	struct pfsnode *pfs;
165 	struct vnode *vp;
166 	int error;
167 
168  retry:
169 	*vpp = procfs_hashget(pid, pfs_type, fd, mp, LK_EXCLUSIVE);
170 	if (*vpp != NULL)
171 		return (0);
172 
173 	error = getnewvnode(VT_PROCFS, mp, procfs_vnodeop_p, NULL, &vp);
174 	if (error) {
175 		*vpp = NULL;
176 		return (error);
177 	}
178 	pfs = malloc(sizeof(struct pfsnode), M_TEMP, M_WAITOK);
179 
180 	mutex_enter(&pfs_hashlock);
181 	if ((*vpp = procfs_hashget(pid, pfs_type, fd, mp, 0)) != NULL) {
182 		mutex_exit(&pfs_hashlock);
183 		ungetnewvnode(vp);
184 		free(pfs, M_TEMP);
185 		goto retry;
186 	}
187 
188 	vp->v_data = pfs;
189 	pfs->pfs_pid = pid;
190 	pfs->pfs_type = pfs_type;
191 	pfs->pfs_vnode = vp;
192 	pfs->pfs_flags = 0;
193 	pfs->pfs_fileno = PROCFS_FILENO(pid, pfs_type, fd);
194 	pfs->pfs_fd = fd;
195 
196 	switch (pfs_type) {
197 	case PFSroot:	/* /proc = dr-xr-xr-x */
198 		vp->v_vflag |= VV_ROOT;
199 		/*FALLTHROUGH*/
200 	case PFSproc:	/* /proc/N = dr-xr-xr-x */
201 		pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH;
202 		vp->v_type = VDIR;
203 		break;
204 
205 	case PFScurproc:	/* /proc/curproc = lr-xr-xr-x */
206 	case PFSself:	/* /proc/self    = lr-xr-xr-x */
207 	case PFScwd:	/* /proc/N/cwd = lr-xr-xr-x */
208 	case PFSchroot:	/* /proc/N/chroot = lr-xr-xr-x */
209 	case PFSexe:	/* /proc/N/exe = lr-xr-xr-x */
210 		pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH;
211 		vp->v_type = VLNK;
212 		break;
213 
214 	case PFSfd:
215 		if (fd == -1) {	/* /proc/N/fd = dr-xr-xr-x */
216 			pfs->pfs_mode = S_IRUSR|S_IXUSR;
217 			vp->v_type = VDIR;
218 		} else {	/* /proc/N/fd/M = [ps-]rw------- */
219 			file_t *fp;
220 			vnode_t *vxp;
221 
222 			if ((fp = fd_getfile2(p, pfs->pfs_fd)) == NULL) {
223 				error = EBADF;
224 				goto bad;
225 			}
226 
227 			pfs->pfs_mode = S_IRUSR|S_IWUSR;
228 			switch (fp->f_type) {
229 			case DTYPE_VNODE:
230 				vxp = fp->f_data;
231 
232 				/*
233 				 * We make symlinks for directories
234 				 * to avoid cycles.
235 				 */
236 				if (vxp->v_type == VDIR)
237 					goto symlink;
238 				vp->v_type = vxp->v_type;
239 				break;
240 			case DTYPE_PIPE:
241 				vp->v_type = VFIFO;
242 				break;
243 			case DTYPE_SOCKET:
244 				vp->v_type = VSOCK;
245 				break;
246 			case DTYPE_KQUEUE:
247 			case DTYPE_MISC:
248 			symlink:
249 				pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|
250 				    S_IXGRP|S_IROTH|S_IXOTH;
251 				vp->v_type = VLNK;
252 				break;
253 			default:
254 				error = EOPNOTSUPP;
255 				closef(fp);
256 				goto bad;
257 			}
258 			closef(fp);
259 		}
260 		break;
261 
262 	case PFSfile:	/* /proc/N/file = -rw------- */
263 	case PFSmem:	/* /proc/N/mem = -rw------- */
264 	case PFSregs:	/* /proc/N/regs = -rw------- */
265 	case PFSfpregs:	/* /proc/N/fpregs = -rw------- */
266 		pfs->pfs_mode = S_IRUSR|S_IWUSR;
267 		vp->v_type = VREG;
268 		break;
269 
270 	case PFSctl:	/* /proc/N/ctl = --w------ */
271 	case PFSnote:	/* /proc/N/note = --w------ */
272 	case PFSnotepg:	/* /proc/N/notepg = --w------ */
273 		pfs->pfs_mode = S_IWUSR;
274 		vp->v_type = VREG;
275 		break;
276 
277 	case PFSmap:	/* /proc/N/map = -r--r--r-- */
278 	case PFSmaps:	/* /proc/N/maps = -r--r--r-- */
279 	case PFSstatus:	/* /proc/N/status = -r--r--r-- */
280 	case PFSstat:	/* /proc/N/stat = -r--r--r-- */
281 	case PFScmdline:	/* /proc/N/cmdline = -r--r--r-- */
282 	case PFSemul:	/* /proc/N/emul = -r--r--r-- */
283 	case PFSmeminfo:	/* /proc/meminfo = -r--r--r-- */
284 	case PFScpustat:	/* /proc/stat = -r--r--r-- */
285 	case PFSdevices:	/* /proc/devices = -r--r--r-- */
286 	case PFScpuinfo:	/* /proc/cpuinfo = -r--r--r-- */
287 	case PFSuptime:	/* /proc/uptime = -r--r--r-- */
288 	case PFSmounts:	/* /proc/mounts = -r--r--r-- */
289 	case PFSloadavg:	/* /proc/loadavg = -r--r--r-- */
290 	case PFSstatm:	/* /proc/N/statm = -r--r--r-- */
291 		pfs->pfs_mode = S_IRUSR|S_IRGRP|S_IROTH;
292 		vp->v_type = VREG;
293 		break;
294 
295 #ifdef __HAVE_PROCFS_MACHDEP
296 	PROCFS_MACHDEP_NODETYPE_CASES
297 		procfs_machdep_allocvp(vp);
298 		break;
299 #endif
300 
301 	default:
302 		panic("procfs_allocvp");
303 	}
304 
305 	procfs_hashins(pfs);
306 	uvm_vnp_setsize(vp, 0);
307 	mutex_exit(&pfs_hashlock);
308 
309 	*vpp = vp;
310 	return (0);
311 
312  bad:
313 	mutex_exit(&pfs_hashlock);
314 	free(pfs, M_TEMP);
315 	vp->v_data = NULL;
316 	ungetnewvnode(vp);
317 	return (error);
318 }
319 
320 int
321 procfs_freevp(struct vnode *vp)
322 {
323 	struct pfsnode *pfs = VTOPFS(vp);
324 
325 	procfs_hashrem(pfs);
326 
327 	free(vp->v_data, M_TEMP);
328 	vp->v_data = NULL;
329 	return (0);
330 }
331 
332 int
333 procfs_rw(void *v)
334 {
335 	struct vop_read_args *ap = v;
336 	struct vnode *vp = ap->a_vp;
337 	struct uio *uio = ap->a_uio;
338 	struct lwp *curl;
339 	struct lwp *l;
340 	struct pfsnode *pfs = VTOPFS(vp);
341 	struct proc *p;
342 	int error;
343 
344 	if (uio->uio_offset < 0)
345 		return EINVAL;
346 
347 	if ((error = procfs_proc_lock(pfs->pfs_pid, &p, ESRCH)) != 0)
348 		return error;
349 
350 	curl = curlwp;
351 
352 	/*
353 	 * Do not allow init to be modified while in secure mode; it
354 	 * could be duped into changing the security level.
355 	 */
356 #define	M2K(m)	((m) == UIO_READ ? KAUTH_REQ_PROCESS_PROCFS_READ : \
357 		 KAUTH_REQ_PROCESS_PROCFS_WRITE)
358 	mutex_enter(p->p_lock);
359 	error = kauth_authorize_process(curl->l_cred, KAUTH_PROCESS_PROCFS,
360 	    p, pfs, KAUTH_ARG(M2K(uio->uio_rw)), NULL);
361 	mutex_exit(p->p_lock);
362 	if (error) {
363 		procfs_proc_unlock(p);
364 		return (error);
365 	}
366 #undef	M2K
367 
368 	mutex_enter(p->p_lock);
369 	LIST_FOREACH(l, &p->p_lwps, l_sibling) {
370 		if (l->l_stat != LSZOMB)
371 			break;
372 	}
373 	/* Process is exiting if no-LWPS or all LWPs are LSZOMB */
374 	if (l == NULL) {
375 		mutex_exit(p->p_lock);
376 		procfs_proc_unlock(p);
377 		return ESRCH;
378 	}
379 
380 	lwp_addref(l);
381 	mutex_exit(p->p_lock);
382 
383 	switch (pfs->pfs_type) {
384 	case PFSnote:
385 	case PFSnotepg:
386 		error = procfs_donote(curl, p, pfs, uio);
387 		break;
388 
389 	case PFSregs:
390 		error = procfs_doregs(curl, l, pfs, uio);
391 		break;
392 
393 	case PFSfpregs:
394 		error = procfs_dofpregs(curl, l, pfs, uio);
395 		break;
396 
397 	case PFSctl:
398 		error = procfs_doctl(curl, l, pfs, uio);
399 		break;
400 
401 	case PFSstatus:
402 		error = procfs_dostatus(curl, l, pfs, uio);
403 		break;
404 
405 	case PFSstat:
406 		error = procfs_do_pid_stat(curl, l, pfs, uio);
407 		break;
408 
409 	case PFSmap:
410 		error = procfs_domap(curl, p, pfs, uio, 0);
411 		break;
412 
413 	case PFSmaps:
414 		error = procfs_domap(curl, p, pfs, uio, 1);
415 		break;
416 
417 	case PFSmem:
418 		error = procfs_domem(curl, l, pfs, uio);
419 		break;
420 
421 	case PFScmdline:
422 		error = procfs_docmdline(curl, p, pfs, uio);
423 		break;
424 
425 	case PFSmeminfo:
426 		error = procfs_domeminfo(curl, p, pfs, uio);
427 		break;
428 
429 	case PFSdevices:
430 		error = procfs_dodevices(curl, p, pfs, uio);
431 		break;
432 
433 	case PFScpuinfo:
434 		error = procfs_docpuinfo(curl, p, pfs, uio);
435 		break;
436 
437 	case PFScpustat:
438 		error = procfs_docpustat(curl, p, pfs, uio);
439 		break;
440 
441 	case PFSloadavg:
442 		error = procfs_doloadavg(curl, p, pfs, uio);
443 		break;
444 
445 	case PFSstatm:
446 		error = procfs_do_pid_statm(curl, l, pfs, uio);
447 		break;
448 
449 	case PFSfd:
450 		error = procfs_dofd(curl, p, pfs, uio);
451 		break;
452 
453 	case PFSuptime:
454 		error = procfs_douptime(curl, p, pfs, uio);
455 		break;
456 
457 	case PFSmounts:
458 		error = procfs_domounts(curl, p, pfs, uio);
459 		break;
460 
461 	case PFSemul:
462 		error = procfs_doemul(curl, p, pfs, uio);
463 		break;
464 
465 #ifdef __HAVE_PROCFS_MACHDEP
466 	PROCFS_MACHDEP_NODETYPE_CASES
467 		error = procfs_machdep_rw(curl, l, pfs, uio);
468 		break;
469 #endif
470 
471 	default:
472 		error = EOPNOTSUPP;
473 		break;
474 	}
475 
476 	/*
477 	 * Release the references that we acquired earlier.
478 	 */
479 	lwp_delref(l);
480 	procfs_proc_unlock(p);
481 
482 	return (error);
483 }
484 
485 /*
486  * Get a string from userland into (bf).  Strip a trailing
487  * nl character (to allow easy access from the shell).
488  * The buffer should be *buflenp + 1 chars long.  vfs_getuserstr
489  * will automatically add a nul char at the end.
490  *
491  * Returns 0 on success or the following errors
492  *
493  * EINVAL:    file offset is non-zero.
494  * EMSGSIZE:  message is longer than kernel buffer
495  * EFAULT:    user i/o buffer is not addressable
496  */
497 int
498 vfs_getuserstr(struct uio *uio, char *bf, int *buflenp)
499 {
500 	int xlen;
501 	int error;
502 
503 	if (uio->uio_offset != 0)
504 		return (EINVAL);
505 
506 	xlen = *buflenp;
507 
508 	/* must be able to read the whole string in one go */
509 	if (xlen < uio->uio_resid)
510 		return (EMSGSIZE);
511 	xlen = uio->uio_resid;
512 
513 	if ((error = uiomove(bf, xlen, uio)) != 0)
514 		return (error);
515 
516 	/* allow multiple writes without seeks */
517 	uio->uio_offset = 0;
518 
519 	/* cleanup string and remove trailing newline */
520 	bf[xlen] = '\0';
521 	xlen = strlen(bf);
522 	if (xlen > 0 && bf[xlen-1] == '\n')
523 		bf[--xlen] = '\0';
524 	*buflenp = xlen;
525 
526 	return (0);
527 }
528 
529 const vfs_namemap_t *
530 vfs_findname(const vfs_namemap_t *nm, const char *bf, int buflen)
531 {
532 
533 	for (; nm->nm_name; nm++)
534 		if (memcmp(bf, nm->nm_name, buflen+1) == 0)
535 			return (nm);
536 
537 	return (0);
538 }
539 
540 /*
541  * Initialize pfsnode hash table.
542  */
543 void
544 procfs_hashinit(void)
545 {
546 	mutex_init(&pfs_hashlock, MUTEX_DEFAULT, IPL_NONE);
547 	mutex_init(&pfs_ihash_lock, MUTEX_DEFAULT, IPL_NONE);
548 	pfs_hashtbl = hashinit(desiredvnodes / 4, HASH_LIST, true, &pfs_ihash);
549 }
550 
551 void
552 procfs_hashreinit(void)
553 {
554 	struct pfsnode *pp;
555 	struct pfs_hashhead *oldhash, *hash;
556 	u_long i, oldmask, mask, val;
557 
558 	hash = hashinit(desiredvnodes / 4, HASH_LIST, true, &mask);
559 
560 	mutex_enter(&pfs_ihash_lock);
561 	oldhash = pfs_hashtbl;
562 	oldmask = pfs_ihash;
563 	pfs_hashtbl = hash;
564 	pfs_ihash = mask;
565 	for (i = 0; i <= oldmask; i++) {
566 		while ((pp = LIST_FIRST(&oldhash[i])) != NULL) {
567 			LIST_REMOVE(pp, pfs_hash);
568 			val = PFSPIDHASH(pp->pfs_pid);
569 			LIST_INSERT_HEAD(&hash[val], pp, pfs_hash);
570 		}
571 	}
572 	mutex_exit(&pfs_ihash_lock);
573 	hashdone(oldhash, HASH_LIST, oldmask);
574 }
575 
576 /*
577  * Free pfsnode hash table.
578  */
579 void
580 procfs_hashdone(void)
581 {
582 	hashdone(pfs_hashtbl, HASH_LIST, pfs_ihash);
583 	mutex_destroy(&pfs_hashlock);
584 	mutex_destroy(&pfs_ihash_lock);
585 }
586 
587 struct vnode *
588 procfs_hashget(pid_t pid, pfstype type, int fd, struct mount *mp, int flags)
589 {
590 	struct pfs_hashhead *ppp;
591 	struct pfsnode *pp;
592 	struct vnode *vp;
593 
594 loop:
595 	mutex_enter(&pfs_ihash_lock);
596 	ppp = &pfs_hashtbl[PFSPIDHASH(pid)];
597 	LIST_FOREACH(pp, ppp, pfs_hash) {
598 		vp = PFSTOV(pp);
599 		if (pid == pp->pfs_pid && pp->pfs_type == type &&
600 		    pp->pfs_fd == fd && vp->v_mount == mp) {
601 		    	if (flags == 0) {
602 				mutex_exit(&pfs_ihash_lock);
603 			} else {
604 				mutex_enter(vp->v_interlock);
605 				mutex_exit(&pfs_ihash_lock);
606 				if (vget(vp, flags))
607 					goto loop;
608 			}
609 			return (vp);
610 		}
611 	}
612 	mutex_exit(&pfs_ihash_lock);
613 	return (NULL);
614 }
615 
616 /*
617  * Insert the pfsnode into the hash table and lock it.
618  */
619 void
620 procfs_hashins(struct pfsnode *pp)
621 {
622 	struct pfs_hashhead *ppp;
623 
624 	/* lock the pfsnode, then put it on the appropriate hash list */
625 	VOP_LOCK(PFSTOV(pp), LK_EXCLUSIVE);
626 
627 	mutex_enter(&pfs_ihash_lock);
628 	ppp = &pfs_hashtbl[PFSPIDHASH(pp->pfs_pid)];
629 	LIST_INSERT_HEAD(ppp, pp, pfs_hash);
630 	mutex_exit(&pfs_ihash_lock);
631 }
632 
633 /*
634  * Remove the pfsnode from the hash table.
635  */
636 void
637 procfs_hashrem(struct pfsnode *pp)
638 {
639 	mutex_enter(&pfs_ihash_lock);
640 	LIST_REMOVE(pp, pfs_hash);
641 	mutex_exit(&pfs_ihash_lock);
642 }
643 
644 void
645 procfs_revoke_vnodes(struct proc *p, void *arg)
646 {
647 	struct pfsnode *pfs, *pnext;
648 	struct vnode *vp;
649 	struct mount *mp = (struct mount *)arg;
650 	struct pfs_hashhead *ppp;
651 
652 	if (!(p->p_flag & PK_SUGID))
653 		return;
654 
655 	mutex_enter(&pfs_ihash_lock);
656 	ppp = &pfs_hashtbl[PFSPIDHASH(p->p_pid)];
657 	for (pfs = LIST_FIRST(ppp); pfs; pfs = pnext) {
658 		vp = PFSTOV(pfs);
659 		pnext = LIST_NEXT(pfs, pfs_hash);
660 		mutex_enter(vp->v_interlock);
661 		if (vp->v_usecount > 0 && pfs->pfs_pid == p->p_pid &&
662 		    vp->v_mount == mp) {
663 		    	vp->v_usecount++;
664 		    	mutex_exit(vp->v_interlock);
665 			mutex_exit(&pfs_ihash_lock);
666 			VOP_REVOKE(vp, REVOKEALL);
667 			vrele(vp);
668 			mutex_enter(&pfs_ihash_lock);
669 		} else {
670 			mutex_exit(vp->v_interlock);
671 		}
672 	}
673 	mutex_exit(&pfs_ihash_lock);
674 }
675 
676 int
677 procfs_proc_lock(int pid, struct proc **bunghole, int notfound)
678 {
679 	struct proc *tp;
680 	int error = 0;
681 
682 	mutex_enter(proc_lock);
683 
684 	if (pid == 0)
685 		tp = &proc0;
686 	else if ((tp = proc_find(pid)) == NULL)
687 		error = notfound;
688 	if (tp != NULL && !rw_tryenter(&tp->p_reflock, RW_READER))
689 		error = EBUSY;
690 
691 	mutex_exit(proc_lock);
692 
693 	*bunghole = tp;
694 	return error;
695 }
696 
697 void
698 procfs_proc_unlock(struct proc *p)
699 {
700 
701 	rw_exit(&p->p_reflock);
702 }
703 
704 int
705 procfs_doemul(struct lwp *curl, struct proc *p,
706     struct pfsnode *pfs, struct uio *uio)
707 {
708 	const char *ename = p->p_emul->e_name;
709 	return uiomove_frombuf(__UNCONST(ename), strlen(ename), uio);
710 }
711