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uvm_unix.c revision 1.26 
      1 /*	$NetBSD: uvm_unix.c,v 1.26 2001/12/08 00:35:34 thorpej Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1997 Charles D. Cranor and Washington University.
      5  * Copyright (c) 1991, 1993 The Regents of the University of California.
      6  * Copyright (c) 1988 University of Utah.
      7  *
      8  * All rights reserved.
      9  *
     10  * This code is derived from software contributed to Berkeley by
     11  * the Systems Programming Group of the University of Utah Computer
     12  * Science Department.
     13  *
     14  * Redistribution and use in source and binary forms, with or without
     15  * modification, are permitted provided that the following conditions
     16  * are met:
     17  * 1. Redistributions of source code must retain the above copyright
     18  *    notice, this list of conditions and the following disclaimer.
     19  * 2. Redistributions in binary form must reproduce the above copyright
     20  *    notice, this list of conditions and the following disclaimer in the
     21  *    documentation and/or other materials provided with the distribution.
     22  * 3. All advertising materials mentioning features or use of this software
     23  *    must display the following acknowledgement:
     24  *      This product includes software developed by Charles D. Cranor,
     25  *	Washington University, the University of California, Berkeley and
     26  *	its contributors.
     27  * 4. Neither the name of the University nor the names of its contributors
     28  *    may be used to endorse or promote products derived from this software
     29  *    without specific prior written permission.
     30  *
     31  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     32  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     33  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     34  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     35  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     39  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     40  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     41  * SUCH DAMAGE.
     42  *
     43  * from: Utah $Hdr: vm_unix.c 1.1 89/11/07$
     44  *      @(#)vm_unix.c   8.1 (Berkeley) 6/11/93
     45  * from: Id: uvm_unix.c,v 1.1.2.2 1997/08/25 18:52:30 chuck Exp
     46  */
     47 
     48 /*
     49  * uvm_unix.c: traditional sbrk/grow interface to vm.
     50  */
     51 
     52 #include <sys/cdefs.h>
     53 __KERNEL_RCSID(0, "$NetBSD: uvm_unix.c,v 1.26 2001/12/08 00:35:34 thorpej Exp $");
     54 
     55 #include <sys/param.h>
     56 #include <sys/systm.h>
     57 #include <sys/proc.h>
     58 #include <sys/resourcevar.h>
     59 #include <sys/vnode.h>
     60 
     61 #include <sys/mount.h>
     62 #include <sys/syscallargs.h>
     63 
     64 #include <uvm/uvm.h>
     65 
     66 /*
     67  * sys_obreak: set break
     68  */
     69 
     70 int
     71 sys_obreak(p, v, retval)
     72 	struct proc *p;
     73 	void *v;
     74 	register_t *retval;
     75 {
     76 	struct sys_obreak_args /* {
     77 		syscallarg(char *) nsize;
     78 	} */ *uap = v;
     79 	struct vmspace *vm = p->p_vmspace;
     80 	vaddr_t new, old;
     81 	int error;
     82 
     83 	old = (vaddr_t)vm->vm_daddr;
     84 	new = round_page((vaddr_t)SCARG(uap, nsize));
     85 	if ((new - old) > p->p_rlimit[RLIMIT_DATA].rlim_cur && new > old)
     86 		return (ENOMEM);
     87 
     88 	old = round_page(old + ptoa(vm->vm_dsize));
     89 
     90 	if (new == old)
     91 		return (0);
     92 
     93 	/*
     94 	 * grow or shrink?
     95 	 */
     96 	if (new > old) {
     97 		error = uvm_map(&vm->vm_map, &old, new - old, NULL,
     98 		    UVM_UNKNOWN_OFFSET, 0,
     99 		    UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_COPY,
    100 		    UVM_ADV_NORMAL, UVM_FLAG_AMAPPAD|UVM_FLAG_FIXED|
    101 		    UVM_FLAG_OVERLAY|UVM_FLAG_COPYONW));
    102 		if (error) {
    103 			uprintf("sbrk: grow %ld failed, error = %d\n",
    104 				new - old, error);
    105 			return error;
    106 		}
    107 		vm->vm_dsize += atop(new - old);
    108 	} else {
    109 		uvm_deallocate(&vm->vm_map, new, old - new);
    110 		vm->vm_dsize -= atop(old - new);
    111 	}
    112 	return 0;
    113 }
    114 
    115 /*
    116  * uvm_grow: enlarge the "stack segment" to include sp.
    117  */
    118 
    119 int
    120 uvm_grow(p, sp)
    121 	struct proc *p;
    122 	vaddr_t sp;
    123 {
    124 	struct vmspace *vm = p->p_vmspace;
    125 	int si;
    126 
    127 	/*
    128 	 * For user defined stacks (from sendsig).
    129 	 */
    130 	if (sp < (vaddr_t)vm->vm_maxsaddr)
    131 		return (0);
    132 
    133 	/*
    134 	 * For common case of already allocated (from trap).
    135 	 */
    136 	if (sp >= USRSTACK - ctob(vm->vm_ssize))
    137 		return (1);
    138 
    139 	/*
    140 	 * Really need to check vs limit and increment stack size if ok.
    141 	 */
    142 	si = btoc(USRSTACK-sp) - vm->vm_ssize;
    143 	if (vm->vm_ssize + si > btoc(p->p_rlimit[RLIMIT_STACK].rlim_cur))
    144 		return (0);
    145 	vm->vm_ssize += si;
    146 	return (1);
    147 }
    148 
    149 /*
    150  * sys_oadvise: old advice system call
    151  */
    152 
    153 /* ARGSUSED */
    154 int
    155 sys_ovadvise(p, v, retval)
    156 	struct proc *p;
    157 	void *v;
    158 	register_t *retval;
    159 {
    160 #if 0
    161 	struct sys_ovadvise_args /* {
    162 		syscallarg(int) anom;
    163 	} */ *uap = v;
    164 #endif
    165 
    166 	return (EINVAL);
    167 }
    168