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
sys_obreak(struct lwp * l,const struct sys_obreak_args * uap,register_t * retval)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
uvm_grow(struct proc * p,vaddr_t sp)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
sys_ovadvise(struct lwp * l,const struct sys_ovadvise_args * uap,register_t * retval)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