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procfs_limit.c revision 1.4 
      1 /*	$NetBSD: procfs_limit.c,v 1.4 2020/05/23 23:42:43 ad Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2019 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Christos Zoulas.
      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 #include <sys/cdefs.h>
     33 __KERNEL_RCSID(0, "$NetBSD: procfs_limit.c,v 1.4 2020/05/23 23:42:43 ad Exp $");
     34 
     35 #include <sys/param.h>
     36 #include <sys/systm.h>
     37 #include <sys/proc.h>
     38 #include <sys/malloc.h>
     39 #include <sys/resource.h>
     40 #include <miscfs/procfs/procfs.h>
     41 
     42 #define MAXBUFFERSIZE (256 * 1024)
     43 
     44 static size_t
     45 prl(char *buf, size_t len, intmax_t lim, char sep)
     46 {
     47 	if (lim == RLIM_INFINITY)
     48 		return snprintf(buf, len, "%#20jx%c", lim, sep);
     49 	else
     50 		return snprintf(buf, len, "%20jd%c", lim, sep);
     51 }
     52 
     53 int
     54 procfs_dolimit(struct lwp *curl, struct proc *p, struct pfsnode *pfs,
     55      struct uio *uio)
     56 {
     57 	static const char *label[] = RLIM_STRINGS;
     58 	int error;
     59 	char *buffer;
     60 	size_t bufsize, pos, i;
     61 	struct rlimit rl[RLIM_NLIMITS];
     62 
     63 	if (uio->uio_rw != UIO_READ)
     64 		return EOPNOTSUPP;
     65 
     66 	mutex_enter(&proc_lock);
     67 	mutex_enter(p->p_lock);
     68 	memcpy(rl, p->p_rlimit, sizeof(rl));
     69 	mutex_exit(p->p_lock);
     70 	mutex_exit(&proc_lock);
     71 
     72 	error = 0;
     73 
     74 	bufsize = (64 * 3) * __arraycount(rl);
     75 	buffer = malloc(bufsize, M_TEMP, M_WAITOK);
     76 	pos = 0;
     77 	for (i = 0; i < __arraycount(rl); i++) {
     78 		pos += snprintf(buffer + pos, bufsize - pos, "%20.20s ",
     79 		    label[i]);
     80 		pos += prl(buffer + pos, bufsize - pos, rl[i].rlim_cur, ' ');
     81 		pos += prl(buffer + pos, bufsize - pos, rl[i].rlim_max, '\n');
     82 	}
     83 
     84 	if ((uintmax_t)uio->uio_offset < pos)
     85 		error = uiomove(buffer + uio->uio_offset,
     86 		    pos - uio->uio_offset, uio);
     87 	else
     88 		error = 0;
     89 
     90 	if (buffer != NULL)
     91 		free(buffer, M_TEMP);
     92 
     93 	return error;
     94 }
     95