uvm_unix.c revision 1.46
1 /* $NetBSD: uvm_unix.c,v 1.46 2016/04/07 03:31:12 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 1.46 2016/04/07 03:31:12 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 60 #ifdef PAX_MPROTECT 61 #include <sys/pax.h> 62 #endif /* PAX_MPROTECT */ 63 64 #include <uvm/uvm.h> 65 66 /* 67 * sys_obreak: set break 68 */ 69 70 int 71 sys_obreak(struct lwp *l, const struct sys_obreak_args *uap, register_t *retval) 72 { 73 /* { 74 syscallarg(char *) nsize; 75 } */ 76 struct proc *p = l->l_proc; 77 struct vmspace *vm = p->p_vmspace; 78 vaddr_t nbreak, obreak; 79 int error; 80 81 mutex_enter(&p->p_auxlock); 82 obreak = (vaddr_t)vm->vm_daddr; 83 nbreak = round_page((vaddr_t)SCARG(uap, nsize)); 84 if (nbreak == 0 85 || ((nbreak - obreak) > p->p_rlimit[RLIMIT_DATA].rlim_cur 86 && nbreak > obreak)) { 87 mutex_exit(&p->p_auxlock); 88 return (ENOMEM); 89 } 90 91 obreak = round_page(obreak + ptoa(vm->vm_dsize)); 92 93 if (nbreak == obreak) { 94 mutex_exit(&p->p_auxlock); 95 return (0); 96 } 97 98 /* 99 * grow or shrink? 100 */ 101 102 if (nbreak > obreak) { 103 vm_prot_t prot = UVM_PROT_READ | UVM_PROT_WRITE; 104 vm_prot_t maxprot = UVM_PROT_ALL; 105 106 PAX_MPROTECT_ADJUST(l, &prot, &maxprot); 107 108 error = uvm_map(&vm->vm_map, &obreak, nbreak - obreak, 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 #ifdef DEBUG 116 uprintf("sbrk: grow %#"PRIxVADDR" failed, error = %d\n", 117 nbreak - obreak, error); 118 #endif 119 mutex_exit(&p->p_auxlock); 120 return (error); 121 } 122 vm->vm_dsize += atop(nbreak - obreak); 123 } else { 124 uvm_deallocate(&vm->vm_map, nbreak, obreak - nbreak); 125 vm->vm_dsize -= atop(obreak - nbreak); 126 } 127 mutex_exit(&p->p_auxlock); 128 129 return (0); 130 } 131 132 /* 133 * uvm_grow: enlarge the "stack segment" to include sp. 134 */ 135 136 int 137 uvm_grow(struct proc *p, vaddr_t sp) 138 { 139 struct vmspace *vm = p->p_vmspace; 140 vsize_t nss; 141 142 /* 143 * For user defined stacks (from sendsig). 144 */ 145 #ifdef __MACHINE_STACK_GROWS_UP 146 if (sp < (vaddr_t)vm->vm_minsaddr) 147 #else 148 if (sp < (vaddr_t)vm->vm_maxsaddr) 149 #endif 150 return (0); 151 152 /* 153 * For common case of already allocated (from trap). 154 */ 155 #ifdef __MACHINE_STACK_GROWS_UP 156 if (sp < USRSTACK + ctob(vm->vm_ssize)) 157 #else 158 if (sp >= USRSTACK - ctob(vm->vm_ssize)) 159 #endif 160 return (1); 161 162 /* 163 * Really need to check vs limit and increment stack size if ok. 164 */ 165 #ifdef __MACHINE_STACK_GROWS_UP 166 nss = btoc(sp - USRSTACK); 167 #else 168 nss = btoc(USRSTACK - sp); 169 #endif 170 if (nss > btoc(p->p_rlimit[RLIMIT_STACK].rlim_cur)) 171 return (0); 172 vm->vm_ssize = nss; 173 return (1); 174 } 175 176 /* 177 * sys_oadvise: old advice system call 178 */ 179 180 /* ARGSUSED */ 181 int 182 sys_ovadvise(struct lwp *l, const struct sys_ovadvise_args *uap, register_t *retval) 183 { 184 #if 0 185 /* { 186 syscallarg(int) anom; 187 } */ 188 #endif 189 190 return (EINVAL); 191 } 192
Indexes created Mon Sep 29 21:09:56 GMT 2025