2 * Copyright (c) 1993 Jan-Simon Pendry
4 * The Regents of the University of California. All rights reserved.
6 * This code is derived from software contributed to Berkeley by
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed by the University of
20 * California, Berkeley and its contributors.
21 * 4. Neither the name of the University nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * @(#)procfs_subr.c 8.6 (Berkeley) 5/14/95
39 * $FreeBSD: src/sys/miscfs/procfs/procfs_subr.c,v 1.26.2.3 2002/02/18 21:28:04 des Exp $
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/sysctl.h>
46 #include <sys/mount.h>
47 #include <sys/vnode.h>
48 #include <sys/malloc.h>
50 #include <miscfs/procfs/procfs.h>
52 static struct pfsnode *pfshead;
56 * allocate a pfsnode/vnode pair. the vnode is
57 * referenced, but not locked.
59 * the pid, pfs_type, and mount point uniquely
60 * identify a pfsnode. the mount point is needed
61 * because someone might mount this filesystem
64 * all pfsnodes are maintained on a singly-linked
65 * list. new nodes are only allocated when they cannot
66 * be found on this list. entries on the list are
67 * removed when the vfs reclaim entry is called.
69 * a single lock is kept for the entire list. this is
70 * needed because the getnewvnode() function can block
71 * waiting for a vnode to become free, in which case there
72 * may be more than one process trying to get the same
73 * vnode. this lock is only taken if we are going to
74 * call getnewvnode, since the kernel itself is single-threaded.
76 * if an entry is found on the list, then call vget() to
77 * take a reference. this is done because there may be
78 * zero references to it and so it needs to removed from
79 * the vnode free list.
82 procfs_allocvp(mp, vpp, pid, pfs_type)
88 struct proc *p = curproc; /* XXX */
95 for (pfs = pfshead; pfs != 0; pfs = pfs->pfs_next) {
97 if (pfs->pfs_pid == pid &&
98 pfs->pfs_type == pfs_type &&
108 * otherwise lock the vp list while we call getnewvnode
109 * since that can block.
111 if (pfsvplock & PROCFS_LOCKED) {
112 pfsvplock |= PROCFS_WANT;
113 (void) tsleep((caddr_t) &pfsvplock, PINOD, "pfsavp", 0);
116 pfsvplock |= PROCFS_LOCKED;
119 * Do the MALLOC before the getnewvnode since doing so afterward
120 * might cause a bogus v_data pointer to get dereferenced
121 * elsewhere if MALLOC should block.
123 MALLOC(pfs, struct pfsnode *, sizeof(struct pfsnode), M_TEMP, M_WAITOK);
125 if ((error = getnewvnode(VT_PROCFS, mp, procfs_vnodeop_p, vpp)) != 0) {
134 pfs->pfs_pid = (pid_t) pid;
135 pfs->pfs_type = pfs_type;
138 pfs->pfs_lockowner = 0;
139 pfs->pfs_fileno = PROCFS_FILENO(pid, pfs_type);
142 case Proot: /* /proc = dr-xr-xr-x */
143 pfs->pfs_mode = (VREAD|VEXEC) |
150 case Pcurproc: /* /proc/curproc = lr--r--r-- */
151 pfs->pfs_mode = (VREAD) |
158 pfs->pfs_mode = (VREAD|VEXEC) |
165 pfs->pfs_mode = (VREAD|VEXEC) |
172 pfs->pfs_mode = (VREAD|VWRITE);
179 pfs->pfs_mode = (VREAD|VWRITE);
186 pfs->pfs_mode = (VWRITE);
195 pfs->pfs_mode = (VREAD) |
202 panic("procfs_allocvp");
205 /* add to procfs vnode list */
206 for (pp = &pfshead; *pp; pp = &(*pp)->pfs_next)
211 pfsvplock &= ~PROCFS_LOCKED;
213 if (pfsvplock & PROCFS_WANT) {
214 pfsvplock &= ~PROCFS_WANT;
215 wakeup((caddr_t) &pfsvplock);
225 struct pfsnode **pfspp;
226 struct pfsnode *pfs = VTOPFS(vp);
228 for (pfspp = &pfshead; *pfspp != 0; pfspp = &(*pfspp)->pfs_next) {
230 *pfspp = pfs->pfs_next;
235 FREE(vp->v_data, M_TEMP);
242 struct vop_read_args *ap;
244 struct vnode *vp = ap->a_vp;
245 struct uio *uio = ap->a_uio;
246 struct proc *curp = uio->uio_procp;
247 struct pfsnode *pfs = VTOPFS(vp);
251 p = PFIND(pfs->pfs_pid);
254 if (p->p_pid == 1 && securelevel > 0 && uio->uio_rw == UIO_WRITE)
257 while (pfs->pfs_lockowner) {
258 tsleep(&pfs->pfs_lockowner, PRIBIO, "pfslck", 0);
260 pfs->pfs_lockowner = curproc->p_pid;
262 switch (pfs->pfs_type) {
265 rtval = procfs_donote(curp, p, pfs, uio);
269 rtval = procfs_doregs(curp, p, pfs, uio);
273 rtval = procfs_dofpregs(curp, p, pfs, uio);
277 rtval = procfs_dodbregs(curp, p, pfs, uio);
281 rtval = procfs_doctl(curp, p, pfs, uio);
285 rtval = procfs_dostatus(curp, p, pfs, uio);
289 rtval = procfs_domap(curp, p, pfs, uio);
293 rtval = procfs_domem(curp, p, pfs, uio);
297 rtval = procfs_dotype(curp, p, pfs, uio);
301 rtval = procfs_docmdline(curp, p, pfs, uio);
305 rtval = procfs_dorlimit(curp, p, pfs, uio);
312 pfs->pfs_lockowner = 0;
313 wakeup(&pfs->pfs_lockowner);
318 * Get a string from userland into (buf). Strip a trailing
319 * nl character (to allow easy access from the shell).
320 * The buffer should be *buflenp + 1 chars long. vfs_getuserstr
321 * will automatically add a nul char at the end.
323 * Returns 0 on success or the following errors
325 * EINVAL: file offset is non-zero.
326 * EMSGSIZE: message is longer than kernel buffer
327 * EFAULT: user i/o buffer is not addressable
330 vfs_getuserstr(uio, buf, buflenp)
338 if (uio->uio_offset != 0)
343 /* must be able to read the whole string in one go */
344 if (xlen < uio->uio_resid)
346 xlen = uio->uio_resid;
348 if ((error = uiomove(buf, xlen, uio)) != 0)
351 /* allow multiple writes without seeks */
354 /* cleanup string and remove trailing newline */
357 if (xlen > 0 && buf[xlen-1] == '\n')
365 vfs_findname(nm, buf, buflen)
371 for (; nm->nm_name; nm++)
372 if (bcmp(buf, nm->nm_name, buflen+1) == 0)
379 procfs_exit(struct proc *p)
382 pid_t pid = p->p_pid;
385 * The reason for this loop is not obvious -- basicly,
386 * procfs_freevp(), which is called via vgone() (eventually),
387 * removes the specified procfs node from the pfshead list.
388 * It does this by *pfsp = pfs->pfs_next, meaning that it
389 * overwrites the node. So when we do pfs = pfs->next, we
390 * end up skipping the node that replaces the one that was
391 * vgone'd. Since it may have been the last one on the list,
392 * it may also have been set to null -- but *our* pfs pointer,
393 * here, doesn't see this. So the loop starts from the beginning
396 * This is not a for() loop because the final event
397 * would be "pfs = pfs->pfs_next"; in the case where
398 * pfs is set to pfshead again, that would mean that
399 * pfshead is skipped over.
404 if (pfs->pfs_pid == pid) {