| 1 | /* $NetBSD: uvm_unix.c,v 1.47 2016/04/07 12:07:36 christos 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. Neither the name of the University nor the names of its contributors |
| 23 | * may be used to endorse or promote products derived from this software |
| 24 | * without specific prior written permission. |
| 25 | * |
| 26 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 27 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 28 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 29 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 30 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 31 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 32 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 33 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 34 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 35 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 36 | * SUCH DAMAGE. |
| 37 | * |
| 38 | * from: Utah $Hdr: vm_unix.c 1.1 89/11/07$ |
| 39 | * @(#)vm_unix.c 8.1 (Berkeley) 6/11/93 |
| 40 | * from: Id: uvm_unix.c,v 1.1.2.2 1997/08/25 18:52:30 chuck Exp |
| 41 | */ |
| 42 | |
| 43 | /* |
| 44 | * uvm_unix.c: traditional sbrk/grow interface to vm. |
| 45 | */ |
| 46 | |
| 47 | #include <sys/cdefs.h> |
| 48 | __KERNEL_RCSID(0, "$NetBSD: uvm_unix.c,v 1.47 2016/04/07 12:07:36 christos Exp $" ); |
| 49 | |
| 50 | #include "opt_pax.h" |
| 51 | |
| 52 | #include <sys/param.h> |
| 53 | #include <sys/systm.h> |
| 54 | #include <sys/proc.h> |
| 55 | #include <sys/resourcevar.h> |
| 56 | |
| 57 | #include <sys/mount.h> |
| 58 | #include <sys/syscallargs.h> |
| 59 | #include <sys/pax.h> |
| 60 | |
| 61 | #include <uvm/uvm.h> |
| 62 | |
| 63 | /* |
| 64 | * sys_obreak: set break |
| 65 | */ |
| 66 | |
| 67 | int |
| 68 | sys_obreak(struct lwp *l, const struct sys_obreak_args *uap, register_t *retval) |
| 69 | { |
| 70 | /* { |
| 71 | syscallarg(char *) nsize; |
| 72 | } */ |
| 73 | struct proc *p = l->l_proc; |
| 74 | struct vmspace *vm = p->p_vmspace; |
| 75 | vaddr_t nbreak, obreak; |
| 76 | int error; |
| 77 | |
| 78 | mutex_enter(&p->p_auxlock); |
| 79 | obreak = (vaddr_t)vm->vm_daddr; |
| 80 | nbreak = round_page((vaddr_t)SCARG(uap, nsize)); |
| 81 | if (nbreak == 0 |
| 82 | || ((nbreak - obreak) > p->p_rlimit[RLIMIT_DATA].rlim_cur |
| 83 | && nbreak > obreak)) { |
| 84 | mutex_exit(&p->p_auxlock); |
| 85 | return (ENOMEM); |
| 86 | } |
| 87 | |
| 88 | obreak = round_page(obreak + ptoa(vm->vm_dsize)); |
| 89 | |
| 90 | if (nbreak == obreak) { |
| 91 | mutex_exit(&p->p_auxlock); |
| 92 | return (0); |
| 93 | } |
| 94 | |
| 95 | /* |
| 96 | * grow or shrink? |
| 97 | */ |
| 98 | |
| 99 | if (nbreak > obreak) { |
| 100 | vm_prot_t prot = UVM_PROT_READ | UVM_PROT_WRITE; |
| 101 | vm_prot_t maxprot = UVM_PROT_ALL; |
| 102 | |
| 103 | PAX_MPROTECT_ADJUST(l, &prot, &maxprot); |
| 104 | |
| 105 | error = uvm_map(&vm->vm_map, &obreak, nbreak - obreak, NULL, |
| 106 | UVM_UNKNOWN_OFFSET, 0, |
| 107 | UVM_MAPFLAG(prot, maxprot, |
| 108 | UVM_INH_COPY, |
| 109 | UVM_ADV_NORMAL, UVM_FLAG_AMAPPAD|UVM_FLAG_FIXED| |
| 110 | UVM_FLAG_OVERLAY|UVM_FLAG_COPYONW)); |
| 111 | if (error) { |
| 112 | #ifdef DEBUG |
| 113 | uprintf("sbrk: grow %#" PRIxVADDR" failed, error = %d\n" , |
| 114 | nbreak - obreak, error); |
| 115 | #endif |
| 116 | mutex_exit(&p->p_auxlock); |
| 117 | return (error); |
| 118 | } |
| 119 | vm->vm_dsize += atop(nbreak - obreak); |
| 120 | } else { |
| 121 | uvm_deallocate(&vm->vm_map, nbreak, obreak - nbreak); |
| 122 | vm->vm_dsize -= atop(obreak - nbreak); |
| 123 | } |
| 124 | mutex_exit(&p->p_auxlock); |
| 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 | #ifdef __MACHINE_STACK_GROWS_UP |
| 143 | if (sp < (vaddr_t)vm->vm_minsaddr) |
| 144 | #else |
| 145 | if (sp < (vaddr_t)vm->vm_maxsaddr) |
| 146 | #endif |
| 147 | return (0); |
| 148 | |
| 149 | /* |
| 150 | * For common case of already allocated (from trap). |
| 151 | */ |
| 152 | #ifdef __MACHINE_STACK_GROWS_UP |
| 153 | if (sp < USRSTACK + ctob(vm->vm_ssize)) |
| 154 | #else |
| 155 | if (sp >= USRSTACK - ctob(vm->vm_ssize)) |
| 156 | #endif |
| 157 | return (1); |
| 158 | |
| 159 | /* |
| 160 | * Really need to check vs limit and increment stack size if ok. |
| 161 | */ |
| 162 | #ifdef __MACHINE_STACK_GROWS_UP |
| 163 | nss = btoc(sp - USRSTACK); |
| 164 | #else |
| 165 | nss = btoc(USRSTACK - sp); |
| 166 | #endif |
| 167 | if (nss > btoc(p->p_rlimit[RLIMIT_STACK].rlim_cur)) |
| 168 | return (0); |
| 169 | vm->vm_ssize = nss; |
| 170 | return (1); |
| 171 | } |
| 172 | |
| 173 | /* |
| 174 | * sys_oadvise: old advice system call |
| 175 | */ |
| 176 | |
| 177 | /* ARGSUSED */ |
| 178 | int |
| 179 | sys_ovadvise(struct lwp *l, const struct sys_ovadvise_args *uap, register_t *retval) |
| 180 | { |
| 181 | #if 0 |
| 182 | /* { |
| 183 | syscallarg(int) anom; |
| 184 | } */ |
| 185 | #endif |
| 186 | |
| 187 | return (EINVAL); |
| 188 | } |
| 189 | |