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uvm_unix.c revision 1.33 
      1 /*	$NetBSD: uvm_unix.c,v 1.33 2006/05/20 15:45:38 elad 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 1.33 2006/05/20 15:45:38 elad Exp $");
     54 
     55 #include "opt_pax.h"
     56 
     57 #include <sys/param.h>
     58 #include <sys/systm.h>
     59 #include <sys/proc.h>
     60 #include <sys/resourcevar.h>
     61 #include <sys/vnode.h>
     62 
     63 #include <sys/mount.h>
     64 #include <sys/sa.h>
     65 #include <sys/syscallargs.h>
     66 
     67 #ifdef PAX_MPROTECT
     68 #include <sys/pax.h>
     69 #endif /* PAX_MPROTECT */
     70 
     71 #include <uvm/uvm.h>
     72 
     73 /*
     74  * sys_obreak: set break
     75  */
     76 
     77 int
     78 sys_obreak(struct lwp *l, void *v, register_t *retval)
     79 {
     80 	struct sys_obreak_args /* {
     81 		syscallarg(char *) nsize;
     82 	} */ *uap = v;
     83 	struct proc *p = l->l_proc;
     84 	struct vmspace *vm = p->p_vmspace;
     85 	vaddr_t new, old;
     86 	int error;
     87 
     88 	old = (vaddr_t)vm->vm_daddr;
     89 	new = round_page((vaddr_t)SCARG(uap, nsize));
     90 	if ((new - old) > p->p_rlimit[RLIMIT_DATA].rlim_cur && new > old)
     91 		return (ENOMEM);
     92 
     93 	old = round_page(old + ptoa(vm->vm_dsize));
     94 
     95 	if (new == old)
     96 		return (0);
     97 
     98 	/*
     99 	 * grow or shrink?
    100 	 */
    101 
    102 	if (new > old) {
    103 		vm_prot_t prot = UVM_PROT_READ | UVM_PROT_WRITE;
    104 		vm_prot_t maxprot = UVM_PROT_ALL;
    105 
    106 #ifdef PAX_MPROTECT
    107 		pax_mprotect(l, &prot, &maxprot);
    108 #endif /* PAX_MPROTECT */
    109 
    110 		error = uvm_map(&vm->vm_map, &old, new - old, NULL,
    111 		    UVM_UNKNOWN_OFFSET, 0,
    112 		    UVM_MAPFLAG(prot, maxprot,
    113 				UVM_INH_COPY,
    114 				UVM_ADV_NORMAL, UVM_FLAG_AMAPPAD|UVM_FLAG_FIXED|
    115 				UVM_FLAG_OVERLAY|UVM_FLAG_COPYONW));
    116 		if (error) {
    117 			uprintf("sbrk: grow %ld failed, error = %d\n",
    118 				new - old, error);
    119 			return (error);
    120 		}
    121 		vm->vm_dsize += atop(new - old);
    122 	} else {
    123 		uvm_deallocate(&vm->vm_map, new, old - new);
    124 		vm->vm_dsize -= atop(old - new);
    125 	}
    126 	return (0);
    127 }
    128 
    129 /*
    130  * uvm_grow: enlarge the "stack segment" to include sp.
    131  */
    132 
    133 int
    134 uvm_grow(struct proc *p, vaddr_t sp)
    135 {
    136 	struct vmspace *vm = p->p_vmspace;
    137 	vsize_t nss;
    138 
    139 	/*
    140 	 * For user defined stacks (from sendsig).
    141 	 */
    142 	if (sp < (vaddr_t)vm->vm_maxsaddr)
    143 		return (0);
    144 
    145 	/*
    146 	 * For common case of already allocated (from trap).
    147 	 */
    148 	if (sp >= USRSTACK - ctob(vm->vm_ssize))
    149 		return (1);
    150 
    151 	/*
    152 	 * Really need to check vs limit and increment stack size if ok.
    153 	 */
    154 	nss = btoc(USRSTACK - sp);
    155 	if (nss > btoc(p->p_rlimit[RLIMIT_STACK].rlim_cur))
    156 		return (0);
    157 	vm->vm_ssize = nss;
    158 	return (1);
    159 }
    160 
    161 /*
    162  * sys_oadvise: old advice system call
    163  */
    164 
    165 /* ARGSUSED */
    166 int
    167 sys_ovadvise(struct lwp *l, void *v, register_t *retval)
    168 {
    169 #if 0
    170 	struct sys_ovadvise_args /* {
    171 		syscallarg(int) anom;
    172 	} */ *uap = v;
    173 #endif
    174 
    175 	return (EINVAL);
    176 }
    177