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 1.11 2004/08/17 18:57:32 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 if ((error = getnewvnode(VT_PROCFS, mp, mp->mnt_vn_ops, vpp)) != 0) {
137 pfs->pfs_pid = (pid_t) pid;
138 pfs->pfs_type = pfs_type;
141 pfs->pfs_lockowner = NULL;
142 pfs->pfs_fileno = PROCFS_FILENO(pid, pfs_type);
145 case Proot: /* /proc = dr-xr-xr-x */
146 pfs->pfs_mode = (VREAD|VEXEC) |
153 case Pself: /* /proc/self = lr--r--r-- */
154 pfs->pfs_mode = (VREAD) |
161 pfs->pfs_mode = (VREAD|VEXEC) |
168 pfs->pfs_mode = (VREAD|VEXEC) |
175 pfs->pfs_mode = (VREAD|VWRITE) |
190 pfs->pfs_mode = (VREAD) |
197 panic("linprocfs_allocvp");
200 /* add to procfs vnode list */
201 for (pp = &pfshead; *pp; pp = &(*pp)->pfs_next)
206 pfsvplock &= ~PROCFS_LOCKED;
208 if (pfsvplock & PROCFS_WANT) {
209 pfsvplock &= ~PROCFS_WANT;
210 wakeup((caddr_t) &pfsvplock);
220 struct pfsnode **pfspp;
221 struct pfsnode *pfs = VTOPFS(vp);
223 for (pfspp = &pfshead; *pfspp != 0; pfspp = &(*pfspp)->pfs_next) {
225 *pfspp = pfs->pfs_next;
230 FREE(vp->v_data, M_TEMP);
237 struct vop_read_args *ap;
239 struct vnode *vp = ap->a_vp;
240 struct uio *uio = ap->a_uio;
241 struct thread *td = uio->uio_td;
242 struct pfsnode *pfs = VTOPFS(vp);
250 p = PFIND(pfs->pfs_pid);
253 if (p->p_pid == 1 && securelevel > 0 && uio->uio_rw == UIO_WRITE)
256 while (pfs->pfs_lockowner) {
257 tsleep(&pfs->pfs_lockowner, 0, "pfslck", 0);
259 pfs->pfs_lockowner = curthread;
261 switch (pfs->pfs_type) {
263 rtval = procfs_domem(curp, p, pfs, uio);
266 rtval = linprocfs_doprocstat(curp, p, pfs, uio);
269 rtval = linprocfs_doprocstatus(curp, p, pfs, uio);
272 rtval = linprocfs_domeminfo(curp, p, pfs, uio);
275 rtval = linprocfs_docpuinfo(curp, p, pfs, uio);
278 rtval = linprocfs_dostat(curp, p, pfs, uio);
281 rtval = linprocfs_douptime(curp, p, pfs, uio);
284 rtval = linprocfs_doversion(curp, p, pfs, uio);
287 rtval = linprocfs_doloadavg(curp, p, pfs, uio);
293 pfs->pfs_lockowner = NULL;
294 wakeup(&pfs->pfs_lockowner);
300 * Get a string from userland into (buf). Strip a trailing
301 * nl character (to allow easy access from the shell).
302 * The buffer should be *buflenp + 1 chars long. vfs_getuserstr
303 * will automatically add a nul char at the end.
305 * Returns 0 on success or the following errors
307 * EINVAL: file offset is non-zero.
308 * EMSGSIZE: message is longer than kernel buffer
309 * EFAULT: user i/o buffer is not addressable
312 vfs_getuserstr(uio, buf, buflenp)
320 if (uio->uio_offset != 0)
325 /* must be able to read the whole string in one go */
326 if (xlen < uio->uio_resid)
328 xlen = uio->uio_resid;
330 if ((error = uiomove(buf, xlen, uio)) != 0)
333 /* allow multiple writes without seeks */
336 /* cleanup string and remove trailing newline */
339 if (xlen > 0 && buf[xlen-1] == '\n')
347 vfs_findname(nm, buf, buflen)
353 for (; nm->nm_name; nm++)
354 if (bcmp(buf, nm->nm_name, buflen+1) == 0)
362 linprocfs_exit(struct thread *td)
365 pid_t pid = (td->td_proc) ? td->td_proc->p_pid : -1; /* YYY */
368 * The reason for this loop is not obvious -- basicly,
369 * linprocfs_freevp(), which is called via vgone() (eventually),
370 * removes the specified procfs node from the pfshead list.
371 * It does this by *pfsp = pfs->pfs_next, meaning that it
372 * overwrites the node. So when we do pfs = pfs->next, we
373 * end up skipping the node that replaces the one that was
374 * vgone'd. Since it may have been the last one on the list,
375 * it may also have been set to null -- but *our* pfs pointer,
376 * here, doesn't see this. So the loop starts from the beginning
379 * This is not a for() loop because the final event
380 * would be "pfs = pfs->pfs_next"; in the case where
381 * pfs is set to pfshead again, that would mean that
382 * pfshead is skipped over.
387 if (pfs->pfs_pid == pid) {