2 * Copyright (c) 2000 Dag-Erling Coïdan Smørgrav
3 * Copyright (c) 1999 Pierre Beyssac
4 * Copyright (c) 1993 Jan-Simon Pendry
6 * The Regents of the University of California. All rights reserved.
8 * This code is derived from software contributed to Berkeley by
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21 * This product includes software developed by the University of
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39 * @(#)procfs_subr.c 8.6 (Berkeley) 5/14/95
41 * $FreeBSD: src/sys/i386/linux/linprocfs/linprocfs_subr.c,v 1.3.2.4 2001/06/25 19:46:47 pirzyk Exp $
42 * $DragonFly: src/sys/emulation/linux/i386/linprocfs/linprocfs_subr.c,v 1.12 2004/08/28 19:02:04 dillon Exp $
45 #include <sys/param.h>
46 #include <sys/systm.h>
48 #include <sys/vnode.h>
49 #include <sys/malloc.h>
50 #include <sys/mount.h>
51 #include "linprocfs.h"
53 static struct pfsnode *pfshead;
56 extern int procfs_domem (struct proc *, struct proc *, struct pfsnode *pfsp, struct uio *uio);
59 * allocate a pfsnode/vnode pair. the vnode is
60 * referenced, but not locked.
62 * the pid, pfs_type, and mount point uniquely
63 * identify a pfsnode. the mount point is needed
64 * because someone might mount this filesystem
67 * all pfsnodes are maintained on a singly-linked
68 * list. new nodes are only allocated when they cannot
69 * be found on this list. entries on the list are
70 * removed when the vfs reclaim entry is called.
72 * a single lock is kept for the entire list. this is
73 * needed because the getnewvnode() function can block
74 * waiting for a vnode to become free, in which case there
75 * may be more than one process trying to get the same
76 * vnode. this lock is only taken if we are going to
77 * call getnewvnode, since the kernel itself is single-threaded.
79 * if an entry is found on the list, then call vget() to
80 * take a reference. this is done because there may be
81 * zero references to it and so it needs to removed from
82 * the vnode free list.
85 linprocfs_allocvp(mp, vpp, pid, pfs_type)
91 struct thread *td = curthread; /* XXX */
98 for (pfs = pfshead; pfs != 0; pfs = pfs->pfs_next) {
100 if (pfs->pfs_pid == pid &&
101 pfs->pfs_type == pfs_type &&
103 if (vget(vp, NULL, 0, td))
111 * otherwise lock the vp list while we call getnewvnode
112 * since that can block.
114 if (pfsvplock & PROCFS_LOCKED) {
115 pfsvplock |= PROCFS_WANT;
116 (void) tsleep((caddr_t) &pfsvplock, 0, "pfsavp", 0);
119 pfsvplock |= PROCFS_LOCKED;
122 * Do the MALLOC before the getnewvnode since doing so afterward
123 * might cause a bogus v_data pointer to get dereferenced
124 * elsewhere if MALLOC should block.
126 MALLOC(pfs, struct pfsnode *, sizeof(struct pfsnode), M_TEMP, M_WAITOK);
128 error = getnewvnode(VT_PROCFS, mp, mp->mnt_vn_ops, vpp, 0, 0);
138 pfs->pfs_pid = (pid_t) pid;
139 pfs->pfs_type = pfs_type;
142 pfs->pfs_lockowner = NULL;
143 pfs->pfs_fileno = PROCFS_FILENO(pid, pfs_type);
146 case Proot: /* /proc = dr-xr-xr-x */
147 pfs->pfs_mode = (VREAD|VEXEC) |
154 case Pself: /* /proc/self = lr--r--r-- */
155 pfs->pfs_mode = (VREAD) |
162 pfs->pfs_mode = (VREAD|VEXEC) |
169 pfs->pfs_mode = (VREAD|VEXEC) |
176 pfs->pfs_mode = (VREAD|VWRITE) |
191 pfs->pfs_mode = (VREAD) |
198 panic("linprocfs_allocvp");
201 /* add to procfs vnode list */
202 for (pp = &pfshead; *pp; pp = &(*pp)->pfs_next)
207 pfsvplock &= ~PROCFS_LOCKED;
209 if (pfsvplock & PROCFS_WANT) {
210 pfsvplock &= ~PROCFS_WANT;
211 wakeup((caddr_t) &pfsvplock);
221 struct pfsnode **pfspp;
222 struct pfsnode *pfs = VTOPFS(vp);
224 for (pfspp = &pfshead; *pfspp != 0; pfspp = &(*pfspp)->pfs_next) {
226 *pfspp = pfs->pfs_next;
231 FREE(vp->v_data, M_TEMP);
238 struct vop_read_args *ap;
240 struct vnode *vp = ap->a_vp;
241 struct uio *uio = ap->a_uio;
242 struct thread *td = uio->uio_td;
243 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, 0, "pfslck", 0);
260 pfs->pfs_lockowner = curthread;
262 switch (pfs->pfs_type) {
264 rtval = procfs_domem(curp, p, pfs, uio);
267 rtval = linprocfs_doprocstat(curp, p, pfs, uio);
270 rtval = linprocfs_doprocstatus(curp, p, pfs, uio);
273 rtval = linprocfs_domeminfo(curp, p, pfs, uio);
276 rtval = linprocfs_docpuinfo(curp, p, pfs, uio);
279 rtval = linprocfs_dostat(curp, p, pfs, uio);
282 rtval = linprocfs_douptime(curp, p, pfs, uio);
285 rtval = linprocfs_doversion(curp, p, pfs, uio);
288 rtval = linprocfs_doloadavg(curp, p, pfs, uio);
294 pfs->pfs_lockowner = NULL;
295 wakeup(&pfs->pfs_lockowner);
301 * Get a string from userland into (buf). Strip a trailing
302 * nl character (to allow easy access from the shell).
303 * The buffer should be *buflenp + 1 chars long. vfs_getuserstr
304 * will automatically add a nul char at the end.
306 * Returns 0 on success or the following errors
308 * EINVAL: file offset is non-zero.
309 * EMSGSIZE: message is longer than kernel buffer
310 * EFAULT: user i/o buffer is not addressable
313 vfs_getuserstr(uio, buf, buflenp)
321 if (uio->uio_offset != 0)
326 /* must be able to read the whole string in one go */
327 if (xlen < uio->uio_resid)
329 xlen = uio->uio_resid;
331 if ((error = uiomove(buf, xlen, uio)) != 0)
334 /* allow multiple writes without seeks */
337 /* cleanup string and remove trailing newline */
340 if (xlen > 0 && buf[xlen-1] == '\n')
348 vfs_findname(nm, buf, buflen)
354 for (; nm->nm_name; nm++)
355 if (bcmp(buf, nm->nm_name, buflen+1) == 0)
363 linprocfs_exit(struct thread *td)
366 pid_t pid = (td->td_proc) ? td->td_proc->p_pid : -1; /* YYY */
369 * The reason for this loop is not obvious -- basicly,
370 * linprocfs_freevp(), which is called via vgone() (eventually),
371 * removes the specified procfs node from the pfshead list.
372 * It does this by *pfsp = pfs->pfs_next, meaning that it
373 * overwrites the node. So when we do pfs = pfs->next, we
374 * end up skipping the node that replaces the one that was
375 * vgone'd. Since it may have been the last one on the list,
376 * it may also have been set to null -- but *our* pfs pointer,
377 * here, doesn't see this. So the loop starts from the beginning
380 * This is not a for() loop because the final event
381 * would be "pfs = pfs->pfs_next"; in the case where
382 * pfs is set to pfshead again, that would mean that
383 * pfshead is skipped over.
388 if (pfs->pfs_pid == pid) {