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procfs_subr.c revision 1.112.2.1
      1 /*	$NetBSD: procfs_subr.c,v 1.112.2.1 2019/06/10 22:09:06 christos 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 1.112.2.1 2019/06/10 22:09:06 christos 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/fstrans.h>
    113 #include <sys/vnode.h>
    114 #include <sys/stat.h>
    115 #include <sys/file.h>
    116 #include <sys/filedesc.h>
    117 #include <sys/kauth.h>
    118 #include <sys/sysctl.h>
    119 
    120 #include <miscfs/procfs/procfs.h>
    121 
    122 /*
    123  * Allocate a pfsnode/vnode pair.  The vnode is referenced.
    124  * The pid, type, and file descriptor uniquely identify a pfsnode.
    125  */
    126 int
    127 procfs_allocvp(struct mount *mp, struct vnode **vpp, pid_t pid,
    128     pfstype type, int fd)
    129 {
    130 	struct pfskey key;
    131 
    132 	memset(&key, 0, sizeof(key));
    133 	key.pk_type = type;
    134 	key.pk_pid = pid;
    135 	key.pk_fd = fd;
    136 
    137 	return vcache_get(mp, &key, sizeof(key), vpp);
    138 }
    139 
    140 int
    141 procfs_rw(void *v)
    142 {
    143 	struct vop_read_args *ap = v;
    144 	struct vnode *vp = ap->a_vp;
    145 	struct uio *uio = ap->a_uio;
    146 	struct lwp *curl;
    147 	struct lwp *l;
    148 	struct pfsnode *pfs = VTOPFS(vp);
    149 	struct proc *p;
    150 	int error;
    151 
    152 	if (uio->uio_offset < 0)
    153 		return EINVAL;
    154 
    155 	if ((error = procfs_proc_lock(pfs->pfs_pid, &p, ESRCH)) != 0)
    156 		return error;
    157 
    158 	curl = curlwp;
    159 
    160 	/*
    161 	 * Do not allow init to be modified while in secure mode; it
    162 	 * could be duped into changing the security level.
    163 	 */
    164 #define	M2K(m)	((m) == UIO_READ ? KAUTH_REQ_PROCESS_PROCFS_READ : \
    165 		 KAUTH_REQ_PROCESS_PROCFS_WRITE)
    166 	mutex_enter(p->p_lock);
    167 	error = kauth_authorize_process(curl->l_cred, KAUTH_PROCESS_PROCFS,
    168 	    p, pfs, KAUTH_ARG(M2K(uio->uio_rw)), NULL);
    169 	mutex_exit(p->p_lock);
    170 	if (error) {
    171 		procfs_proc_unlock(p);
    172 		return (error);
    173 	}
    174 #undef	M2K
    175 
    176 	mutex_enter(p->p_lock);
    177 	LIST_FOREACH(l, &p->p_lwps, l_sibling) {
    178 		if (l->l_stat != LSZOMB)
    179 			break;
    180 	}
    181 	/* Process is exiting if no-LWPS or all LWPs are LSZOMB */
    182 	if (l == NULL) {
    183 		mutex_exit(p->p_lock);
    184 		procfs_proc_unlock(p);
    185 		return ESRCH;
    186 	}
    187 
    188 	lwp_addref(l);
    189 	mutex_exit(p->p_lock);
    190 
    191 	switch (pfs->pfs_type) {
    192 	case PFSnote:
    193 	case PFSnotepg:
    194 		error = procfs_donote(curl, p, pfs, uio);
    195 		break;
    196 
    197 	case PFSregs:
    198 		error = procfs_doregs(curl, l, pfs, uio);
    199 		break;
    200 
    201 	case PFSfpregs:
    202 		error = procfs_dofpregs(curl, l, pfs, uio);
    203 		break;
    204 
    205 	case PFSstatus:
    206 		error = procfs_dostatus(curl, l, pfs, uio);
    207 		break;
    208 
    209 	case PFSstat:
    210 		error = procfs_do_pid_stat(curl, l, pfs, uio);
    211 		break;
    212 
    213 	case PFSlimit:
    214 		error = procfs_dolimit(curl, p, pfs, uio);
    215 		break;
    216 
    217 	case PFSmap:
    218 		error = procfs_domap(curl, p, pfs, uio, 0);
    219 		break;
    220 
    221 	case PFSmaps:
    222 		error = procfs_domap(curl, p, pfs, uio, 1);
    223 		break;
    224 
    225 	case PFSmem:
    226 		error = procfs_domem(curl, l, pfs, uio);
    227 		break;
    228 
    229 	case PFScmdline:
    230 		error = procfs_doprocargs(curl, p, pfs, uio, KERN_PROC_ARGV);
    231 		break;
    232 
    233 	case PFSenviron:
    234 		error = procfs_doprocargs(curl, p, pfs, uio, KERN_PROC_ENV);
    235 		break;
    236 
    237 	case PFSmeminfo:
    238 		error = procfs_domeminfo(curl, p, pfs, uio);
    239 		break;
    240 
    241 	case PFSdevices:
    242 		error = procfs_dodevices(curl, p, pfs, uio);
    243 		break;
    244 
    245 	case PFScpuinfo:
    246 		error = procfs_docpuinfo(curl, p, pfs, uio);
    247 		break;
    248 
    249 	case PFScpustat:
    250 		error = procfs_docpustat(curl, p, pfs, uio);
    251 		break;
    252 
    253 	case PFSloadavg:
    254 		error = procfs_doloadavg(curl, p, pfs, uio);
    255 		break;
    256 
    257 	case PFSstatm:
    258 		error = procfs_do_pid_statm(curl, l, pfs, uio);
    259 		break;
    260 
    261 	case PFSfd:
    262 		error = procfs_dofd(curl, p, pfs, uio);
    263 		break;
    264 
    265 	case PFSuptime:
    266 		error = procfs_douptime(curl, p, pfs, uio);
    267 		break;
    268 
    269 	case PFSmounts:
    270 		error = procfs_domounts(curl, p, pfs, uio);
    271 		break;
    272 
    273 	case PFSemul:
    274 		error = procfs_doemul(curl, p, pfs, uio);
    275 		break;
    276 
    277 	case PFSversion:
    278 		error = procfs_doversion(curl, p, pfs, uio);
    279 		break;
    280 
    281 	case PFSauxv:
    282 		error = procfs_doauxv(curl, p, pfs, uio);
    283 		break;
    284 
    285 #ifdef __HAVE_PROCFS_MACHDEP
    286 	PROCFS_MACHDEP_NODETYPE_CASES
    287 		error = procfs_machdep_rw(curl, l, pfs, uio);
    288 		break;
    289 #endif
    290 
    291 	default:
    292 		error = EOPNOTSUPP;
    293 		break;
    294 	}
    295 
    296 	/*
    297 	 * Release the references that we acquired earlier.
    298 	 */
    299 	lwp_delref(l);
    300 	procfs_proc_unlock(p);
    301 
    302 	return (error);
    303 }
    304 
    305 /*
    306  * Get a string from userland into (bf).  Strip a trailing
    307  * nl character (to allow easy access from the shell).
    308  * The buffer should be *buflenp + 1 chars long.  vfs_getuserstr
    309  * will automatically add a nul char at the end.
    310  *
    311  * Returns 0 on success or the following errors
    312  *
    313  * EINVAL:    file offset is non-zero.
    314  * EMSGSIZE:  message is longer than kernel buffer
    315  * EFAULT:    user i/o buffer is not addressable
    316  */
    317 int
    318 vfs_getuserstr(struct uio *uio, char *bf, int *buflenp)
    319 {
    320 	int xlen;
    321 	int error;
    322 
    323 	if (uio->uio_offset != 0)
    324 		return (EINVAL);
    325 
    326 	xlen = *buflenp;
    327 
    328 	/* must be able to read the whole string in one go */
    329 	if (xlen < uio->uio_resid)
    330 		return (EMSGSIZE);
    331 	xlen = uio->uio_resid;
    332 
    333 	if ((error = uiomove(bf, xlen, uio)) != 0)
    334 		return (error);
    335 
    336 	/* allow multiple writes without seeks */
    337 	uio->uio_offset = 0;
    338 
    339 	/* cleanup string and remove trailing newline */
    340 	bf[xlen] = '\0';
    341 	xlen = strlen(bf);
    342 	if (xlen > 0 && bf[xlen-1] == '\n')
    343 		bf[--xlen] = '\0';
    344 	*buflenp = xlen;
    345 
    346 	return (0);
    347 }
    348 
    349 const vfs_namemap_t *
    350 vfs_findname(const vfs_namemap_t *nm, const char *bf, int buflen)
    351 {
    352 
    353 	for (; nm->nm_name; nm++)
    354 		if (memcmp(bf, nm->nm_name, buflen+1) == 0)
    355 			return (nm);
    356 
    357 	return (0);
    358 }
    359 
    360 static bool
    361 procfs_revoke_selector(void *arg, struct vnode *vp)
    362 {
    363 	struct proc *p = arg;
    364 	struct pfsnode *pfs;
    365 
    366 	KASSERT(mutex_owned(vp->v_interlock));
    367 
    368 	pfs = VTOPFS(vp);
    369 
    370 	return (pfs != NULL && pfs->pfs_pid == p->p_pid);
    371 }
    372 
    373 void
    374 procfs_revoke_vnodes(struct proc *p, void *arg)
    375 {
    376 	int error;
    377 	bool suspended;
    378 	struct vnode *vp;
    379 	struct vnode_iterator *marker;
    380 	struct mount *mp = (struct mount *)arg;
    381 
    382 	if (!(p->p_flag & PK_SUGID))
    383 		return;
    384 
    385 	suspended = false;
    386 	vfs_vnode_iterator_init(mp, &marker);
    387 
    388 	while ((vp = vfs_vnode_iterator_next(marker,
    389 	    procfs_revoke_selector, p)) != NULL) {
    390 		if (vrecycle(vp))
    391 			continue;
    392 		/* Vnode is busy, we have to suspend the mount for vgone(). */
    393 		while (! suspended) {
    394 			error = vfs_suspend(mp, 0);
    395 			if (error == 0) {
    396 				suspended = true;
    397 			} else if (error != EINTR && error != ERESTART) {
    398 				KASSERT(error == EOPNOTSUPP);
    399 				break;
    400 			}
    401 		}
    402 		vgone(vp);
    403 	}
    404 
    405 	if (suspended)
    406 		vfs_resume(mp);
    407 
    408 	vfs_vnode_iterator_destroy(marker);
    409 }
    410 
    411 int
    412 procfs_proc_lock(int pid, struct proc **bunghole, int notfound)
    413 {
    414 	struct proc *tp;
    415 	int error = 0;
    416 
    417 	mutex_enter(proc_lock);
    418 
    419 	if (pid == 0)
    420 		tp = &proc0;
    421 	else if ((tp = proc_find(pid)) == NULL)
    422 		error = notfound;
    423 	if (tp != NULL && !rw_tryenter(&tp->p_reflock, RW_READER))
    424 		error = EBUSY;
    425 
    426 	mutex_exit(proc_lock);
    427 
    428 	*bunghole = tp;
    429 	return error;
    430 }
    431 
    432 void
    433 procfs_proc_unlock(struct proc *p)
    434 {
    435 
    436 	rw_exit(&p->p_reflock);
    437 }
    438 
    439 int
    440 procfs_doemul(struct lwp *curl, struct proc *p,
    441     struct pfsnode *pfs, struct uio *uio)
    442 {
    443 	const char *ename = p->p_emul->e_name;
    444 	return uiomove_frombuf(__UNCONST(ename), strlen(ename), uio);
    445 }
    446