NetBSD/sys/miscfs/procfs/procfs_subr.c

470 lines
12 KiB
C

/* $NetBSD: procfs_subr.c,v 1.40 2001/12/05 00:58:05 thorpej Exp $ */
/*
* Copyright (c) 1994 Christopher G. Demetriou. All rights reserved.
* Copyright (c) 1993 Jan-Simon Pendry
* Copyright (c) 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Jan-Simon Pendry.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)procfs_subr.c 8.6 (Berkeley) 5/14/95
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: procfs_subr.c,v 1.40 2001/12/05 00:58:05 thorpej Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/malloc.h>
#include <sys/stat.h>
#include <miscfs/procfs/procfs.h>
void procfs_hashins __P((struct pfsnode *));
void procfs_hashrem __P((struct pfsnode *));
struct vnode *procfs_hashget __P((pid_t, pfstype, struct mount *));
LIST_HEAD(pfs_hashhead, pfsnode) *pfs_hashtbl;
u_long pfs_ihash; /* size of hash table - 1 */
#define PFSPIDHASH(pid) ((pid) & pfs_ihash)
struct lock pfs_hashlock;
struct simplelock pfs_hash_slock;
#define ISSET(t, f) ((t) & (f))
/*
* allocate a pfsnode/vnode pair. the vnode is
* referenced, and locked.
*
* the pid, pfs_type, and mount point uniquely
* identify a pfsnode. the mount point is needed
* because someone might mount this filesystem
* twice.
*
* all pfsnodes are maintained on a singly-linked
* list. new nodes are only allocated when they cannot
* be found on this list. entries on the list are
* removed when the vfs reclaim entry is called.
*
* a single lock is kept for the entire list. this is
* needed because the getnewvnode() function can block
* waiting for a vnode to become free, in which case there
* may be more than one process trying to get the same
* vnode. this lock is only taken if we are going to
* call getnewvnode, since the kernel itself is single-threaded.
*
* if an entry is found on the list, then call vget() to
* take a reference. this is done because there may be
* zero references to it and so it needs to removed from
* the vnode free list.
*/
int
procfs_allocvp(mp, vpp, pid, pfs_type)
struct mount *mp;
struct vnode **vpp;
long pid;
pfstype pfs_type;
{
struct pfsnode *pfs;
struct vnode *vp;
int error;
do {
if ((*vpp = procfs_hashget(pid, pfs_type, mp)) != NULL)
return (0);
} while (lockmgr(&pfs_hashlock, LK_EXCLUSIVE|LK_SLEEPFAIL, 0));
if ((error = getnewvnode(VT_PROCFS, mp, procfs_vnodeop_p, vpp)) != 0) {
*vpp = NULL;
lockmgr(&pfs_hashlock, LK_RELEASE, NULL);
return (error);
}
vp = *vpp;
MALLOC(pfs, void *, sizeof(struct pfsnode), M_TEMP, M_WAITOK);
vp->v_data = pfs;
pfs->pfs_pid = (pid_t) pid;
pfs->pfs_type = pfs_type;
pfs->pfs_vnode = vp;
pfs->pfs_flags = 0;
pfs->pfs_fileno = PROCFS_FILENO(pid, pfs_type);
switch (pfs_type) {
case Proot: /* /proc = dr-xr-xr-x */
pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH;
vp->v_type = VDIR;
vp->v_flag = VROOT;
break;
case Pcurproc: /* /proc/curproc = lr-xr-xr-x */
case Pself: /* /proc/self = lr-xr-xr-x */
pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH;
vp->v_type = VLNK;
break;
case Pproc: /* /proc/N = dr-xr-xr-x */
pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH;
vp->v_type = VDIR;
break;
case Pfile: /* /proc/N/file = -rw------- */
case Pmem: /* /proc/N/mem = -rw------- */
case Pregs: /* /proc/N/regs = -rw------- */
case Pfpregs: /* /proc/N/fpregs = -rw------- */
pfs->pfs_mode = S_IRUSR|S_IWUSR;
vp->v_type = VREG;
break;
case Pctl: /* /proc/N/ctl = --w------ */
case Pnote: /* /proc/N/note = --w------ */
case Pnotepg: /* /proc/N/notepg = --w------ */
pfs->pfs_mode = S_IWUSR;
vp->v_type = VREG;
break;
case Pmap: /* /proc/N/map = -r--r--r-- */
case Pmaps: /* /proc/N/maps = -r--r--r-- */
case Pstatus: /* /proc/N/status = -r--r--r-- */
case Pcmdline: /* /proc/N/cmdline = -r--r--r-- */
case Pmeminfo: /* /proc/meminfo = -r--r--r-- */
case Pcpuinfo: /* /proc/cpuinfo = -r--r--r-- */
pfs->pfs_mode = S_IRUSR|S_IRGRP|S_IROTH;
vp->v_type = VREG;
break;
#ifdef __HAVE_PROCFS_MACHDEP
PROCFS_MACHDEP_NODETYPE_CASES
procfs_machdep_allocvp(vp);
break;
#endif
default:
panic("procfs_allocvp");
}
procfs_hashins(pfs);
uvm_vnp_setsize(vp, 0);
lockmgr(&pfs_hashlock, LK_RELEASE, NULL);
return (error);
}
int
procfs_freevp(vp)
struct vnode *vp;
{
struct pfsnode *pfs = VTOPFS(vp);
procfs_hashrem(pfs);
FREE(vp->v_data, M_TEMP);
vp->v_data = 0;
return (0);
}
int
procfs_rw(v)
void *v;
{
struct vop_read_args *ap = v;
struct vnode *vp = ap->a_vp;
struct uio *uio = ap->a_uio;
struct proc *curp = uio->uio_procp;
struct pfsnode *pfs = VTOPFS(vp);
struct proc *p;
p = PFIND(pfs->pfs_pid);
if (p == 0)
return (EINVAL);
switch (pfs->pfs_type) {
case Pregs:
case Pfpregs:
case Pmem:
#if defined(__HAVE_PROCFS_MACHDEP) && defined(PROCFS_MACHDEP_PROTECT_CASES)
PROCFS_MACHDEP_PROTECT_CASES
#endif
/*
* Do not allow init to be modified while in secure mode; it
* could be duped into changing the security level.
*/
if (uio->uio_rw == UIO_WRITE &&
p == initproc && securelevel > -1)
return (EPERM);
break;
default:
break;
}
switch (pfs->pfs_type) {
case Pnote:
case Pnotepg:
return (procfs_donote(curp, p, pfs, uio));
case Pregs:
return (procfs_doregs(curp, p, pfs, uio));
case Pfpregs:
return (procfs_dofpregs(curp, p, pfs, uio));
case Pctl:
return (procfs_doctl(curp, p, pfs, uio));
case Pstatus:
return (procfs_dostatus(curp, p, pfs, uio));
case Pmap:
return (procfs_domap(curp, p, pfs, uio, 0));
case Pmaps:
return (procfs_domap(curp, p, pfs, uio, 1));
case Pmem:
return (procfs_domem(curp, p, pfs, uio));
case Pcmdline:
return (procfs_docmdline(curp, p, pfs, uio));
case Pmeminfo:
return (procfs_domeminfo(curp, p, pfs, uio));
case Pcpuinfo:
return (procfs_docpuinfo(curp, p, pfs, uio));
#ifdef __HAVE_PROCFS_MACHDEP
PROCFS_MACHDEP_NODETYPE_CASES
return (procfs_machdep_rw(curp, p, pfs, uio));
#endif
default:
return (EOPNOTSUPP);
}
}
/*
* Get a string from userland into (buf). Strip a trailing
* nl character (to allow easy access from the shell).
* The buffer should be *buflenp + 1 chars long. vfs_getuserstr
* will automatically add a nul char at the end.
*
* Returns 0 on success or the following errors
*
* EINVAL: file offset is non-zero.
* EMSGSIZE: message is longer than kernel buffer
* EFAULT: user i/o buffer is not addressable
*/
int
vfs_getuserstr(uio, buf, buflenp)
struct uio *uio;
char *buf;
int *buflenp;
{
int xlen;
int error;
if (uio->uio_offset != 0)
return (EINVAL);
xlen = *buflenp;
/* must be able to read the whole string in one go */
if (xlen < uio->uio_resid)
return (EMSGSIZE);
xlen = uio->uio_resid;
if ((error = uiomove(buf, xlen, uio)) != 0)
return (error);
/* allow multiple writes without seeks */
uio->uio_offset = 0;
/* cleanup string and remove trailing newline */
buf[xlen] = '\0';
xlen = strlen(buf);
if (xlen > 0 && buf[xlen-1] == '\n')
buf[--xlen] = '\0';
*buflenp = xlen;
return (0);
}
const vfs_namemap_t *
vfs_findname(nm, buf, buflen)
const vfs_namemap_t *nm;
const char *buf;
int buflen;
{
for (; nm->nm_name; nm++)
if (memcmp(buf, nm->nm_name, buflen+1) == 0)
return (nm);
return (0);
}
/*
* Initialize pfsnode hash table.
*/
void
procfs_hashinit()
{
lockinit(&pfs_hashlock, PINOD, "pfs_hashlock", 0, 0);
pfs_hashtbl = hashinit(desiredvnodes / 4, HASH_LIST, M_UFSMNT,
M_WAITOK, &pfs_ihash);
simple_lock_init(&pfs_hash_slock);
}
void
procfs_hashreinit()
{
struct pfsnode *pp;
struct pfs_hashhead *oldhash, *hash;
u_long oldmask, mask, val;
int i;
hash = hashinit(desiredvnodes / 4, HASH_LIST, M_UFSMNT, M_WAITOK,
&mask);
simple_lock(&pfs_hash_slock);
oldhash = pfs_hashtbl;
oldmask = pfs_ihash;
pfs_hashtbl = hash;
pfs_ihash = mask;
for (i = 0; i <= oldmask; i++) {
while ((pp = LIST_FIRST(&oldhash[i])) != NULL) {
LIST_REMOVE(pp, pfs_hash);
val = PFSPIDHASH(pp->pfs_pid);
LIST_INSERT_HEAD(&hash[val], pp, pfs_hash);
}
}
simple_unlock(&pfs_hash_slock);
hashdone(oldhash, M_UFSMNT);
}
/*
* Free pfsnode hash table.
*/
void
procfs_hashdone()
{
hashdone(pfs_hashtbl, M_UFSMNT);
}
struct vnode *
procfs_hashget(pid, type, mp)
pid_t pid;
pfstype type;
struct mount *mp;
{
struct pfs_hashhead *ppp;
struct pfsnode *pp;
struct vnode *vp;
loop:
simple_lock(&pfs_hash_slock);
ppp = &pfs_hashtbl[PFSPIDHASH(pid)];
LIST_FOREACH(pp, ppp, pfs_hash) {
vp = PFSTOV(pp);
if (pid == pp->pfs_pid && pp->pfs_type == type &&
vp->v_mount == mp) {
simple_lock(&vp->v_interlock);
simple_unlock(&pfs_hash_slock);
if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK))
goto loop;
return (vp);
}
}
simple_unlock(&pfs_hash_slock);
return (NULL);
}
/*
* Insert the pfsnode into the hash table and lock it.
*/
void
procfs_hashins(pp)
struct pfsnode *pp;
{
struct pfs_hashhead *ppp;
/* lock the pfsnode, then put it on the appropriate hash list */
lockmgr(&pp->pfs_vnode->v_lock, LK_EXCLUSIVE, (struct simplelock *)0);
simple_lock(&pfs_hash_slock);
ppp = &pfs_hashtbl[PFSPIDHASH(pp->pfs_pid)];
LIST_INSERT_HEAD(ppp, pp, pfs_hash);
simple_unlock(&pfs_hash_slock);
}
/*
* Remove the pfsnode from the hash table.
*/
void
procfs_hashrem(pp)
struct pfsnode *pp;
{
simple_lock(&pfs_hash_slock);
LIST_REMOVE(pp, pfs_hash);
simple_unlock(&pfs_hash_slock);
}
void
procfs_revoke_vnodes(p, arg)
struct proc *p;
void *arg;
{
struct pfsnode *pfs, *pnext;
struct vnode *vp;
struct mount *mp = (struct mount *)arg;
struct pfs_hashhead *ppp;
if (!(p->p_flag & P_SUGID))
return;
ppp = &pfs_hashtbl[PFSPIDHASH(p->p_pid)];
for (pfs = LIST_FIRST(ppp); pfs; pfs = pnext) {
vp = PFSTOV(pfs);
pnext = LIST_NEXT(pfs, pfs_hash);
if (vp->v_usecount > 0 && pfs->pfs_pid == p->p_pid &&
vp->v_mount == mp)
VOP_REVOKE(vp, REVOKEALL);
}
}