xref: /openbsd-src/sys/uvm/uvm_unix.c (revision 5c7bcd7eaef67423bb4a9e46c9af663e1c2eb4b0)
1 /*	$OpenBSD: uvm_unix.c,v 1.57 2016/03/15 18:16:47 stefan Exp $	*/
2 /*	$NetBSD: uvm_unix.c,v 1.18 2000/09/13 15:00:25 thorpej Exp $	*/
3 
4 /*
5  * Copyright (c) 1997 Charles D. Cranor and Washington University.
6  * Copyright (c) 1991, 1993 The Regents of the University of California.
7  * Copyright (c) 1988 University of Utah.
8  *
9  * All rights reserved.
10  *
11  * This code is derived from software contributed to Berkeley by
12  * the Systems Programming Group of the University of Utah Computer
13  * Science Department.
14  *
15  * Redistribution and use in source and binary forms, with or without
16  * modification, are permitted provided that the following conditions
17  * are met:
18  * 1. Redistributions of source code must retain the above copyright
19  *    notice, this list of conditions and the following disclaimer.
20  * 2. Redistributions in binary form must reproduce the above copyright
21  *    notice, this list of conditions and the following disclaimer in the
22  *    documentation and/or other materials provided with the distribution.
23  * 3. Neither the name of the University nor the names of its contributors
24  *    may be used to endorse or promote products derived from this software
25  *    without specific prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37  * SUCH DAMAGE.
38  *
39  * from: Utah $Hdr: vm_unix.c 1.1 89/11/07$
40  *      @(#)vm_unix.c   8.1 (Berkeley) 6/11/93
41  * from: Id: uvm_unix.c,v 1.1.2.2 1997/08/25 18:52:30 chuck Exp
42  */
43 
44 /*
45  * uvm_unix.c: traditional sbrk/grow interface to vm.
46  */
47 
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/proc.h>
51 #include <sys/resourcevar.h>
52 #include <sys/vnode.h>
53 
54 #include <sys/mount.h>
55 #include <sys/syscallargs.h>
56 
57 #include <uvm/uvm.h>
58 
59 /*
60  * sys_obreak: set break
61  */
62 
63 int
64 sys_obreak(struct proc *p, void *v, register_t *retval)
65 {
66 	struct sys_obreak_args /* {
67 		syscallarg(char *) nsize;
68 	} */ *uap = v;
69 	struct vmspace *vm = p->p_vmspace;
70 	vaddr_t new, old, base;
71 	int error;
72 
73 	base = (vaddr_t)vm->vm_daddr;
74 	new = round_page((vaddr_t)SCARG(uap, nsize));
75 	if (new < base || (new - base) > p->p_rlimit[RLIMIT_DATA].rlim_cur)
76 		return (ENOMEM);
77 
78 	old = round_page(base + ptoa(vm->vm_dsize));
79 
80 	if (new == old)
81 		return (0);
82 
83 	/* grow or shrink? */
84 	if (new > old) {
85 		error = uvm_map(&vm->vm_map, &old, new - old, NULL,
86 		    UVM_UNKNOWN_OFFSET, 0,
87 		    UVM_MAPFLAG(PROT_READ | PROT_WRITE,
88 		    PROT_READ | PROT_WRITE | PROT_EXEC, MAP_INHERIT_COPY,
89 		    MADV_NORMAL, UVM_FLAG_AMAPPAD|UVM_FLAG_FIXED|
90 		    UVM_FLAG_COPYONW));
91 		if (error) {
92 			uprintf("sbrk: grow %ld failed, error = %d\n",
93 			    new - old, error);
94 			return (ENOMEM);
95 		}
96 		vm->vm_dsize += atop(new - old);
97 	} else {
98 		uvm_deallocate(&vm->vm_map, new, old - new);
99 		vm->vm_dsize -= atop(old - new);
100 	}
101 
102 	return (0);
103 }
104 
105 /*
106  * uvm_grow: enlarge the "stack segment" to include sp.
107  */
108 void
109 uvm_grow(struct proc *p, vaddr_t sp)
110 {
111 	struct vmspace *vm = p->p_vmspace;
112 	int si;
113 
114 	/* For user defined stacks (from sendsig). */
115 	if (sp < (vaddr_t)vm->vm_maxsaddr)
116 		return;
117 
118 	/* For common case of already allocated (from trap). */
119 #ifdef MACHINE_STACK_GROWS_UP
120 	if (sp < (vaddr_t)vm->vm_maxsaddr + ptoa(vm->vm_ssize))
121 #else
122 	if (sp >= (vaddr_t)vm->vm_minsaddr - ptoa(vm->vm_ssize))
123 #endif
124 		return;
125 
126 	/* Really need to check vs limit and increment stack size if ok. */
127 #ifdef MACHINE_STACK_GROWS_UP
128 	si = atop(sp - (vaddr_t)vm->vm_maxsaddr) - vm->vm_ssize + 1;
129 #else
130 	si = atop((vaddr_t)vm->vm_minsaddr - sp) - vm->vm_ssize;
131 #endif
132 	if (vm->vm_ssize + si <= atop(p->p_rlimit[RLIMIT_STACK].rlim_cur))
133 		vm->vm_ssize += si;
134 }
135 
136 #ifndef SMALL_KERNEL
137 
138 /*
139  * Walk the VA space for a process, invoking 'func' on each present range
140  * that should be included in a coredump.
141  */
142 int
143 uvm_coredump_walkmap(struct proc *p, void *iocookie,
144     int (*func)(struct proc *, void *, struct uvm_coredump_state *),
145     void *cookie)
146 {
147 	struct uvm_coredump_state state;
148 	struct vmspace *vm = p->p_vmspace;
149 	struct vm_map *map = &vm->vm_map;
150 	struct vm_map_entry *entry;
151 	vaddr_t top;
152 	int error;
153 
154 	RB_FOREACH(entry, uvm_map_addr, &map->addr) {
155 		state.cookie = cookie;
156 		state.prot = entry->protection;
157 		state.flags = 0;
158 
159 		/* should never happen for a user process */
160 		if (UVM_ET_ISSUBMAP(entry)) {
161 			panic("%s: user process with submap?", __func__);
162 		}
163 
164 		if (!(entry->protection & PROT_WRITE) &&
165 		    entry->start != p->p_p->ps_sigcode)
166 			continue;
167 
168 		/* Don't dump mmaped devices. */
169 		if (entry->object.uvm_obj != NULL &&
170 		    UVM_OBJ_IS_DEVICE(entry->object.uvm_obj))
171 			continue;
172 
173 		state.start = entry->start;
174 		state.realend = entry->end;
175 		state.end = entry->end;
176 
177 		if (state.start >= VM_MAXUSER_ADDRESS)
178 			continue;
179 
180 		if (state.end > VM_MAXUSER_ADDRESS)
181 			state.end = VM_MAXUSER_ADDRESS;
182 
183 #ifdef MACHINE_STACK_GROWS_UP
184 		if ((vaddr_t)vm->vm_maxsaddr <= state.start &&
185 		    state.start < ((vaddr_t)vm->vm_maxsaddr + MAXSSIZ)) {
186 			top = round_page((vaddr_t)vm->vm_maxsaddr +
187 			    ptoa(vm->vm_ssize));
188 			if (state.end > top)
189 				state.end = top;
190 
191 			if (state.start >= state.end)
192 				continue;
193 #else
194 		if (state.start >= (vaddr_t)vm->vm_maxsaddr) {
195 			top = trunc_page((vaddr_t)vm->vm_minsaddr -
196 			    ptoa(vm->vm_ssize));
197 			if (state.start < top)
198 				state.start = top;
199 
200 			if (state.start >= state.end)
201 				continue;
202 #endif
203 			state.flags |= UVM_COREDUMP_STACK;
204 		}
205 
206 		error = (*func)(p, iocookie, &state);
207 		if (error)
208 			return (error);
209 	}
210 
211 	return (0);
212 }
213 
214 #endif	/* !SMALL_KERNEL */
215