sys/uvm/uvm_unix.c

   1 /*      $NetBSD: uvm_unix.c,v 1.42 2009/11/27 12:25:10 njoly 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 1.42 2009/11/27 12:25:10 njoly 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         mutex_enter(&p->p_auxlock);
  87         old = (vaddr_t)vm->vm_daddr;
  88         new = round_page((vaddr_t)SCARG(uap, nsize));
  89         if (new == 0 ||
  90             ((new - old) > p->p_rlimit[RLIMIT_DATA].rlim_cur && new > old)) {
  91                 mutex_exit(&p->p_auxlock);
  92                 return (ENOMEM);
  93         }
  94
  95         old = round_page(old + ptoa(vm->vm_dsize));
  96
  97         if (new == old) {
  98                 mutex_exit(&p->p_auxlock);
  99                 return (0);
 100         }
 101
 102         /*
 103          * grow or shrink?
 104          */
 105
 106         if (new > old) {
 107                 vm_prot_t prot = UVM_PROT_READ | UVM_PROT_WRITE;
 108                 vm_prot_t maxprot = UVM_PROT_ALL;
 109
 110 #ifdef PAX_MPROTECT
 111                 pax_mprotect(l, &prot, &maxprot);
 112 #endif /* PAX_MPROTECT */
 113
 114                 error = uvm_map(&vm->vm_map, &old, new - old, NULL,
 115                     UVM_UNKNOWN_OFFSET, 0,
 116                     UVM_MAPFLAG(prot, maxprot,
 117                                 UVM_INH_COPY,
 118                                 UVM_ADV_NORMAL, UVM_FLAG_AMAPPAD|UVM_FLAG_FIXED|
 119                                 UVM_FLAG_OVERLAY|UVM_FLAG_COPYONW));
 120                 if (error) {
 121 #ifdef DEBUG
 122                         uprintf("sbrk: grow %#"PRIxVADDR" failed, error = %d\n",
 123                             new - old, error);
 124 #endif
 125                         mutex_exit(&p->p_auxlock);
 126                         return (error);
 127                 }
 128                 vm->vm_dsize += atop(new - old);
 129         } else {
 130                 uvm_deallocate(&vm->vm_map, new, old - new);
 131                 vm->vm_dsize -= atop(old - new);
 132         }
 133         mutex_exit(&p->p_auxlock);
 134
 135         return (0);
 136 }
 137
 138 /*
 139  * uvm_grow: enlarge the "stack segment" to include sp.
 140  */
 141
 142 int
 143 uvm_grow(struct proc *p, vaddr_t sp)
 144 {
 145         struct vmspace *vm = p->p_vmspace;
 146         vsize_t nss;
 147
 148         /*
 149          * For user defined stacks (from sendsig).
 150          */
 151 #ifdef __MACHINE_STACK_GROWS_UP
 152         if (sp < (vaddr_t)vm->vm_minsaddr)
 153 #else
 154         if (sp < (vaddr_t)vm->vm_maxsaddr)
 155 #endif
 156                 return (0);
 157
 158         /*
 159          * For common case of already allocated (from trap).
 160          */
 161 #ifdef __MACHINE_STACK_GROWS_UP
 162         if (sp < USRSTACK + ctob(vm->vm_ssize))
 163 #else
 164         if (sp >= USRSTACK - ctob(vm->vm_ssize))
 165 #endif
 166                 return (1);
 167
 168         /*
 169          * Really need to check vs limit and increment stack size if ok.
 170          */
 171 #ifdef __MACHINE_STACK_GROWS_UP
 172         nss = btoc(sp - USRSTACK);
 173 #else
 174         nss = btoc(USRSTACK - sp);
 175 #endif
 176         if (nss > btoc(p->p_rlimit[RLIMIT_STACK].rlim_cur))
 177                 return (0);
 178         vm->vm_ssize = nss;
 179         return (1);
 180 }
 181
 182 /*
 183  * sys_oadvise: old advice system call
 184  */
 185
 186 /* ARGSUSED */
 187 int
 188 sys_ovadvise(struct lwp *l, const struct sys_ovadvise_args *uap, register_t *retval)
 189 {
 190 #if 0
 191         /* {
 192                 syscallarg(int) anom;
 193         } */
 194 #endif
 195
 196         return (EINVAL);
 197 }