1 /* 2 * Copyright (c) 1988 University of Utah. 3 * Copyright (c) 1991, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * the Systems Programming Group of the University of Utah Computer 8 * Science Department. 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 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * from: Utah $Hdr: vm_unix.c 1.1 89/11/07$ 39 * 40 * @(#)vm_unix.c 8.1 (Berkeley) 6/11/93 41 * $FreeBSD: src/sys/vm/vm_unix.c,v 1.24.2.2 2002/07/02 20:06:19 dillon Exp $ 42 * $DragonFly: src/sys/vm/vm_unix.c,v 1.7 2006/11/07 17:51:24 dillon Exp $ 43 */ 44 45 /* 46 * Traditional sbrk/grow interface to VM 47 */ 48 #include <sys/param.h> 49 #include <sys/sysproto.h> 50 #include <sys/proc.h> 51 #include <sys/resourcevar.h> 52 53 #include <vm/vm.h> 54 #include <vm/vm_param.h> 55 #include <sys/lock.h> 56 #include <vm/pmap.h> 57 #include <vm/vm_map.h> 58 59 /* 60 * obreak_args(char *nsize) 61 */ 62 /* ARGSUSED */ 63 int 64 sys_obreak(struct obreak_args *uap) 65 { 66 struct proc *p = curproc; 67 struct vmspace *vm = p->p_vmspace; 68 vm_offset_t new, old, base; 69 int rv; 70 71 base = round_page((vm_offset_t) vm->vm_daddr); 72 new = round_page((vm_offset_t)uap->nsize); 73 old = base + ctob(vm->vm_dsize); 74 if (new > base) { 75 /* 76 * We check resource limits here, but alow processes to 77 * reduce their usage, even if they remain over the limit. 78 */ 79 if (new > old && 80 (new - base) > (unsigned) p->p_rlimit[RLIMIT_DATA].rlim_cur) 81 return ENOMEM; 82 if (new >= VM_MAX_USER_ADDRESS) 83 return (ENOMEM); 84 } else if (new < base) { 85 /* 86 * This is simply an invalid value. If someone wants to 87 * do fancy address space manipulations, mmap and munmap 88 * can do most of what the user would want. 89 */ 90 return EINVAL; 91 } 92 93 if (new > old) { 94 vm_size_t diff; 95 96 diff = new - old; 97 if (vm->vm_map.size + diff > p->p_rlimit[RLIMIT_VMEM].rlim_cur) 98 return(ENOMEM); 99 rv = vm_map_find(&vm->vm_map, NULL, 0, 100 &old, diff, 101 FALSE, 102 VM_MAPTYPE_NORMAL, 103 VM_PROT_ALL, VM_PROT_ALL, 104 0); 105 if (rv != KERN_SUCCESS) { 106 return (ENOMEM); 107 } 108 vm->vm_dsize += btoc(diff); 109 } else if (new < old) { 110 rv = vm_map_remove(&vm->vm_map, new, old); 111 if (rv != KERN_SUCCESS) { 112 return (ENOMEM); 113 } 114 vm->vm_dsize -= btoc(old - new); 115 } 116 return (0); 117 } 118