1 /* $NetBSD: uvm_unix.c,v 1.51 2022/01/10 18:04:20 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 1.51 2022/01/10 18:04:20 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_RW; 101 vm_prot_t maxprot; 102 103 maxprot = PAX_MPROTECT_MAXPROTECT(l, prot, 0, UVM_PROT_ALL); 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 < p->p_stackbase + ctob(vm->vm_ssize)) 154 #else 155 if (sp >= p->p_stackbase - 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 - p->p_stackbase); 164 #else 165 nss = btoc(p->p_stackbase - 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
Indexes created Sat Sep 20 22:09:52 GMT 2025