Home | History | Annotate | Line # | Download | only in uvm
uvm_unix.c revision 1.39
      1 /*	$NetBSD: uvm_unix.c,v 1.39 2007/12/20 23:03:15 dsl 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 1.39 2007/12/20 23:03:15 dsl 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 
     62 #include <sys/mount.h>
     63 #include <sys/syscallargs.h>
     64 
     65 #ifdef PAX_MPROTECT
     66 #include <sys/pax.h>
     67 #endif /* PAX_MPROTECT */
     68 
     69 #include <uvm/uvm.h>
     70 
     71 /*
     72  * sys_obreak: set break
     73  */
     74 
     75 int
     76 sys_obreak(struct lwp *l, const struct sys_obreak_args *uap, register_t *retval)
     77 {
     78 	/* {
     79 		syscallarg(char *) nsize;
     80 	} */
     81 	struct proc *p = l->l_proc;
     82 	struct vmspace *vm = p->p_vmspace;
     83 	vaddr_t new, old;
     84 	int error;
     85 
     86 	old = (vaddr_t)vm->vm_daddr;
     87 	new = round_page((vaddr_t)SCARG(uap, nsize));
     88 	if ((new - old) > p->p_rlimit[RLIMIT_DATA].rlim_cur && new > old)
     89 		return (ENOMEM);
     90 
     91 	old = round_page(old + ptoa(vm->vm_dsize));
     92 
     93 	if (new == old)
     94 		return (0);
     95 
     96 	/*
     97 	 * grow or shrink?
     98 	 */
     99 
    100 	if (new > old) {
    101 		vm_prot_t prot = UVM_PROT_READ | UVM_PROT_WRITE;
    102 		vm_prot_t maxprot = UVM_PROT_ALL;
    103 
    104 #ifdef PAX_MPROTECT
    105 		pax_mprotect(l, &prot, &maxprot);
    106 #endif /* PAX_MPROTECT */
    107 
    108 		error = uvm_map(&vm->vm_map, &old, new - old, NULL,
    109 		    UVM_UNKNOWN_OFFSET, 0,
    110 		    UVM_MAPFLAG(prot, maxprot,
    111 				UVM_INH_COPY,
    112 				UVM_ADV_NORMAL, UVM_FLAG_AMAPPAD|UVM_FLAG_FIXED|
    113 				UVM_FLAG_OVERLAY|UVM_FLAG_COPYONW));
    114 		if (error) {
    115 			uprintf("sbrk: grow %ld failed, error = %d\n",
    116 				new - old, error);
    117 			return (error);
    118 		}
    119 		vm->vm_dsize += atop(new - old);
    120 	} else {
    121 		uvm_deallocate(&vm->vm_map, new, old - new);
    122 		vm->vm_dsize -= atop(old - new);
    123 	}
    124 	return (0);
    125 }
    126 
    127 /*
    128  * uvm_grow: enlarge the "stack segment" to include sp.
    129  */
    130 
    131 int
    132 uvm_grow(struct proc *p, vaddr_t sp)
    133 {
    134 	struct vmspace *vm = p->p_vmspace;
    135 	vsize_t nss;
    136 
    137 	/*
    138 	 * For user defined stacks (from sendsig).
    139 	 */
    140 #ifdef __MACHINE_STACK_GROWS_UP
    141 	if (sp < (vaddr_t)vm->vm_minsaddr)
    142 #else
    143 	if (sp < (vaddr_t)vm->vm_maxsaddr)
    144 #endif
    145 		return (0);
    146 
    147 	/*
    148 	 * For common case of already allocated (from trap).
    149 	 */
    150 #ifdef __MACHINE_STACK_GROWS_UP
    151 	if (sp < USRSTACK + ctob(vm->vm_ssize))
    152 #else
    153 	if (sp >= USRSTACK - ctob(vm->vm_ssize))
    154 #endif
    155 		return (1);
    156 
    157 	/*
    158 	 * Really need to check vs limit and increment stack size if ok.
    159 	 */
    160 #ifdef __MACHINE_STACK_GROWS_UP
    161 	nss = btoc(sp - USRSTACK);
    162 #else
    163 	nss = btoc(USRSTACK - sp);
    164 #endif
    165 	if (nss > btoc(p->p_rlimit[RLIMIT_STACK].rlim_cur))
    166 		return (0);
    167 	vm->vm_ssize = nss;
    168 	return (1);
    169 }
    170 
    171 /*
    172  * sys_oadvise: old advice system call
    173  */
    174 
    175 /* ARGSUSED */
    176 int
    177 sys_ovadvise(struct lwp *l, const struct sys_ovadvise_args *uap, register_t *retval)
    178 {
    179 #if 0
    180 	/* {
    181 		syscallarg(int) anom;
    182 	} */
    183 #endif
    184 
    185 	return (EINVAL);
    186 }
    187