xref: /openbsd-src/sys/uvm/uvm_unix.c (revision 43003dfe3ad45d1698bed8a37f2b0f5b14f20d4f)
1 /*	$OpenBSD: uvm_unix.c,v 1.39 2009/06/17 22:19:12 kettenis 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. All advertising materials mentioning features or use of this software
24  *    must display the following acknowledgement:
25  *      This product includes software developed by Charles D. Cranor,
26  *	Washington University, the University of California, Berkeley and
27  *	its contributors.
28  * 4. Neither the name of the University nor the names of its contributors
29  *    may be used to endorse or promote products derived from this software
30  *    without specific prior written permission.
31  *
32  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
33  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
34  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
35  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
36  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
37  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
38  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
39  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
40  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
41  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
42  * SUCH DAMAGE.
43  *
44  * from: Utah $Hdr: vm_unix.c 1.1 89/11/07$
45  *      @(#)vm_unix.c   8.1 (Berkeley) 6/11/93
46  * from: Id: uvm_unix.c,v 1.1.2.2 1997/08/25 18:52:30 chuck Exp
47  */
48 
49 /*
50  * uvm_unix.c: traditional sbrk/grow interface to vm.
51  */
52 
53 #include <sys/param.h>
54 #include <sys/systm.h>
55 #include <sys/proc.h>
56 #include <sys/resourcevar.h>
57 #include <sys/vnode.h>
58 #include <sys/core.h>
59 
60 #include <sys/mount.h>
61 #include <sys/syscallargs.h>
62 
63 #include <uvm/uvm.h>
64 
65 /*
66  * sys_obreak: set break
67  */
68 
69 int
70 sys_obreak(struct proc *p, void *v, register_t *retval)
71 {
72 	struct sys_obreak_args /* {
73 		syscallarg(char *) nsize;
74 	} */ *uap = v;
75 	struct vmspace *vm = p->p_vmspace;
76 	vaddr_t new, old;
77 	int error;
78 
79 	old = (vaddr_t)vm->vm_daddr;
80 	new = round_page((vaddr_t)SCARG(uap, nsize));
81 	if ((new - old) > p->p_rlimit[RLIMIT_DATA].rlim_cur)
82 		return (ENOMEM);
83 
84 	old = round_page(old + ptoa(vm->vm_dsize));
85 
86 	if (new == old)
87 		return (0);
88 
89 	/*
90 	 * grow or shrink?
91 	 */
92 	if (new > old) {
93 		error = uvm_map(&vm->vm_map, &old, new - old, NULL,
94 		    UVM_UNKNOWN_OFFSET, 0,
95 		    UVM_MAPFLAG(UVM_PROT_RW, UVM_PROT_RWX, UVM_INH_COPY,
96 		    UVM_ADV_NORMAL, UVM_FLAG_AMAPPAD|UVM_FLAG_FIXED|
97 		    UVM_FLAG_OVERLAY|UVM_FLAG_COPYONW));
98 		if (error) {
99 			uprintf("sbrk: grow %ld failed, error = %d\n",
100 			    new - old, error);
101 			return (ENOMEM);
102 		}
103 		vm->vm_dsize += atop(new - old);
104 	} else {
105 		uvm_deallocate(&vm->vm_map, new, old - new);
106 		vm->vm_dsize -= atop(old - new);
107 	}
108 
109 	return (0);
110 }
111 
112 /*
113  * uvm_grow: enlarge the "stack segment" to include sp.
114  */
115 
116 void
117 uvm_grow(struct proc *p, vaddr_t sp)
118 {
119 	struct vmspace *vm = p->p_vmspace;
120 	int si;
121 
122 	/*
123 	 * For user defined stacks (from sendsig).
124 	 */
125 	if (sp < (vaddr_t)vm->vm_maxsaddr)
126 		return;
127 
128 	/*
129 	 * For common case of already allocated (from trap).
130 	 */
131 #ifdef MACHINE_STACK_GROWS_UP
132 	if (sp < USRSTACK + ptoa(vm->vm_ssize))
133 #else
134 	if (sp >= USRSTACK - ptoa(vm->vm_ssize))
135 #endif
136 		return;
137 
138 	/*
139 	 * Really need to check vs limit and increment stack size if ok.
140 	 */
141 #ifdef MACHINE_STACK_GROWS_UP
142 	si = atop(sp - USRSTACK) - vm->vm_ssize + 1;
143 #else
144 	si = atop(USRSTACK - sp) - vm->vm_ssize;
145 #endif
146 	if (vm->vm_ssize + si <= atop(p->p_rlimit[RLIMIT_STACK].rlim_cur))
147 		vm->vm_ssize += si;
148 }
149 
150 #ifndef SMALL_KERNEL
151 
152 /*
153  * uvm_coredump: dump core!
154  */
155 
156 int
157 uvm_coredump(struct proc *p, struct vnode *vp, struct ucred *cred,
158     struct core *chdr)
159 {
160 	struct vmspace *vm = p->p_vmspace;
161 	vm_map_t map = &vm->vm_map;
162 	vm_map_entry_t entry;
163 	vaddr_t start, end, top;
164 	struct coreseg cseg;
165 	off_t offset;
166 	int flag, error = 0;
167 
168 	offset = chdr->c_hdrsize + chdr->c_seghdrsize + chdr->c_cpusize;
169 
170 	for (entry = map->header.next; entry != &map->header;
171 	    entry = entry->next) {
172 
173 		/* should never happen for a user process */
174 		if (UVM_ET_ISSUBMAP(entry)) {
175 			panic("uvm_coredump: user process with submap?");
176 		}
177 
178 		if (!(entry->protection & VM_PROT_WRITE) &&
179 		    entry->start != p->p_sigcode)
180 			continue;
181 
182 		/*
183 		 * Don't dump mmaped devices.
184 		 */
185 		if (entry->object.uvm_obj != NULL &&
186 		    UVM_OBJ_IS_DEVICE(entry->object.uvm_obj))
187 			continue;
188 
189 		start = entry->start;
190 		end = entry->end;
191 
192 		if (start >= VM_MAXUSER_ADDRESS)
193 			continue;
194 
195 		if (end > VM_MAXUSER_ADDRESS)
196 			end = VM_MAXUSER_ADDRESS;
197 
198 #ifdef MACHINE_STACK_GROWS_UP
199 		if (USRSTACK <= start && start < (USRSTACK + MAXSSIZ)) {
200 			top = round_page(USRSTACK + ptoa(vm->vm_ssize));
201 			if (end > top)
202 				end = top;
203 
204 			if (start >= end)
205 				continue;
206 #else
207 		if (start >= (vaddr_t)vm->vm_maxsaddr) {
208 			top = trunc_page(USRSTACK - ptoa(vm->vm_ssize));
209 			if (start < top)
210 				start = top;
211 
212 			if (start >= end)
213 				continue;
214 #endif
215 			flag = CORE_STACK;
216 		} else
217 			flag = CORE_DATA;
218 
219 		/*
220 		 * Set up a new core file segment.
221 		 */
222 		CORE_SETMAGIC(cseg, CORESEGMAGIC, CORE_GETMID(*chdr), flag);
223 		cseg.c_addr = start;
224 		cseg.c_size = end - start;
225 
226 		error = vn_rdwr(UIO_WRITE, vp,
227 		    (caddr_t)&cseg, chdr->c_seghdrsize,
228 		    offset, UIO_SYSSPACE,
229 		    IO_NODELOCKED|IO_UNIT, cred, NULL, p);
230 		/*
231 		 * We might get an EFAULT on objects mapped beyond
232 		 * EOF. Ignore the error.
233 		 */
234 		if (error && error != EFAULT)
235 			break;
236 
237 		offset += chdr->c_seghdrsize;
238 		error = vn_rdwr(UIO_WRITE, vp,
239 		    (caddr_t)(u_long)cseg.c_addr, (int)cseg.c_size,
240 		    offset, UIO_USERSPACE,
241 		    IO_NODELOCKED|IO_UNIT, cred, NULL, p);
242 		if (error)
243 			break;
244 
245 		offset += cseg.c_size;
246 		chdr->c_nseg++;
247 	}
248 
249 	return (error);
250 }
251 
252 int
253 uvm_coredump_walkmap(struct proc *p, void *iocookie,
254     int (*func)(struct proc *, void *, struct uvm_coredump_state *),
255     void *cookie)
256 {
257 	struct uvm_coredump_state state;
258 	struct vmspace *vm = p->p_vmspace;
259 	struct vm_map *map = &vm->vm_map;
260 	struct vm_map_entry *entry;
261 	vaddr_t top;
262 	int error;
263 
264 	for (entry = map->header.next; entry != &map->header;
265 	    entry = entry->next) {
266 
267 		state.cookie = cookie;
268 		state.prot = entry->protection;
269 		state.flags = 0;
270 
271 		/* should never happen for a user process */
272 		if (UVM_ET_ISSUBMAP(entry)) {
273 			panic("uvm_coredump: user process with submap?");
274 		}
275 
276 		if (!(entry->protection & VM_PROT_WRITE) &&
277 		    entry->start != p->p_sigcode)
278 			continue;
279 
280 		/*
281 		 * Don't dump mmaped devices.
282 		 */
283 		if (entry->object.uvm_obj != NULL &&
284 		    UVM_OBJ_IS_DEVICE(entry->object.uvm_obj))
285 			continue;
286 
287 		state.start = entry->start;
288 		state.realend = entry->end;
289 		state.end = entry->end;
290 
291 		if (state.start >= VM_MAXUSER_ADDRESS)
292 			continue;
293 
294 		if (state.end > VM_MAXUSER_ADDRESS)
295 			state.end = VM_MAXUSER_ADDRESS;
296 
297 #ifdef MACHINE_STACK_GROWS_UP
298 		if (USRSTACK <= state.start &&
299 		    state.start < (USRSTACK + MAXSSIZ)) {
300 			top = round_page(USRSTACK + ptoa(vm->vm_ssize));
301 			if (state.end > top)
302 				state.end = top;
303 
304 			if (state.start >= state.end)
305 				continue;
306 #else
307 		if (state.start >= (vaddr_t)vm->vm_maxsaddr) {
308 			top = trunc_page(USRSTACK - ptoa(vm->vm_ssize));
309 			if (state.start < top)
310 				state.start = top;
311 
312 			if (state.start >= state.end)
313 				continue;
314 #endif
315 			state.flags |= UVM_COREDUMP_STACK;
316 		}
317 
318 		error = (*func)(p, iocookie, &state);
319 		if (error)
320 			return (error);
321 	}
322 
323 	return (0);
324 }
325 
326 #endif	/* !SMALL_KERNEL */
327