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uvm_unix.c revision 1.31 
      1 /*	$NetBSD: uvm_unix.c,v 1.31 2005/06/27 02:19:48 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 1.31 2005/06/27 02:19:48 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/sa.h>
     63 #include <sys/syscallargs.h>
     64 
     65 #include <uvm/uvm.h>
     66 
     67 /*
     68  * sys_obreak: set break
     69  */
     70 
     71 int
     72 sys_obreak(struct lwp *l, void *v, register_t *retval)
     73 {
     74 	struct sys_obreak_args /* {
     75 		syscallarg(char *) nsize;
     76 	} */ *uap = v;
     77 	struct proc *p = l->l_proc;
     78 	struct vmspace *vm = p->p_vmspace;
     79 	vaddr_t new, old;
     80 	int error;
     81 
     82 	old = (vaddr_t)vm->vm_daddr;
     83 	new = round_page((vaddr_t)SCARG(uap, nsize));
     84 	if ((new - old) > p->p_rlimit[RLIMIT_DATA].rlim_cur && new > old)
     85 		return (ENOMEM);
     86 
     87 	old = round_page(old + ptoa(vm->vm_dsize));
     88 
     89 	if (new == old)
     90 		return (0);
     91 
     92 	/*
     93 	 * grow or shrink?
     94 	 */
     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_READ | UVM_PROT_WRITE, UVM_PROT_ALL,
    100 				UVM_INH_COPY,
    101 				UVM_ADV_NORMAL, UVM_FLAG_AMAPPAD|UVM_FLAG_FIXED|
    102 				UVM_FLAG_OVERLAY|UVM_FLAG_COPYONW));
    103 		if (error) {
    104 			uprintf("sbrk: grow %ld failed, error = %d\n",
    105 				new - old, error);
    106 			return (error);
    107 		}
    108 		vm->vm_dsize += atop(new - old);
    109 	} else {
    110 		uvm_deallocate(&vm->vm_map, new, old - new);
    111 		vm->vm_dsize -= atop(old - new);
    112 	}
    113 	return (0);
    114 }
    115 
    116 /*
    117  * uvm_grow: enlarge the "stack segment" to include sp.
    118  */
    119 
    120 int
    121 uvm_grow(struct proc *p, vaddr_t sp)
    122 {
    123 	struct vmspace *vm = p->p_vmspace;
    124 	vsize_t nss;
    125 
    126 	/*
    127 	 * For user defined stacks (from sendsig).
    128 	 */
    129 	if (sp < (vaddr_t)vm->vm_maxsaddr)
    130 		return (0);
    131 
    132 	/*
    133 	 * For common case of already allocated (from trap).
    134 	 */
    135 	if (sp >= USRSTACK - ctob(vm->vm_ssize))
    136 		return (1);
    137 
    138 	/*
    139 	 * Really need to check vs limit and increment stack size if ok.
    140 	 */
    141 	nss = btoc(USRSTACK - sp);
    142 	if (nss > btoc(p->p_rlimit[RLIMIT_STACK].rlim_cur))
    143 		return (0);
    144 	vm->vm_ssize = nss;
    145 	return (1);
    146 }
    147 
    148 /*
    149  * sys_oadvise: old advice system call
    150  */
    151 
    152 /* ARGSUSED */
    153 int
    154 sys_ovadvise(struct lwp *l, void *v, register_t *retval)
    155 {
    156 #if 0
    157 	struct sys_ovadvise_args /* {
    158 		syscallarg(int) anom;
    159 	} */ *uap = v;
    160 #endif
    161 
    162 	return (EINVAL);
    163 }
    164