xref: /openbsd-src/sys/uvm/uvm_unix.c (revision 91f110e064cd7c194e59e019b83bb7496c1c84d4)
1 /*	$OpenBSD: uvm_unix.c,v 1.47 2013/01/16 21:47:08 deraadt 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, base;
77 	int error;
78 
79 	base = (vaddr_t)vm->vm_daddr;
80 	new = round_page((vaddr_t)SCARG(uap, nsize));
81 	if (new < base || (new - base) > p->p_rlimit[RLIMIT_DATA].rlim_cur)
82 		return (ENOMEM);
83 
84 	old = round_page(base + 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, safe;
163 	vaddr_t start, end, top;
164 	struct coreseg cseg;
165 	off_t offset, coffset;
166 	int csize, chunk, flag, error = 0;
167 
168 	offset = chdr->c_hdrsize + chdr->c_seghdrsize + chdr->c_cpusize;
169 
170 	RB_FOREACH_SAFE(entry, uvm_map_addr, &map->addr, safe) {
171 		/* should never happen for a user process */
172 		if (UVM_ET_ISSUBMAP(entry)) {
173 			panic("uvm_coredump: user process with submap?");
174 		}
175 
176 		if (!(entry->protection & VM_PROT_WRITE) &&
177 		    entry->start != p->p_sigcode)
178 			continue;
179 
180 		/*
181 		 * Don't dump mmaped devices.
182 		 */
183 		if (entry->object.uvm_obj != NULL &&
184 		    UVM_OBJ_IS_DEVICE(entry->object.uvm_obj))
185 			continue;
186 
187 		start = entry->start;
188 		end = entry->end;
189 
190 		if (start >= VM_MAXUSER_ADDRESS)
191 			continue;
192 
193 		if (end > VM_MAXUSER_ADDRESS)
194 			end = VM_MAXUSER_ADDRESS;
195 
196 #ifdef MACHINE_STACK_GROWS_UP
197 		if (USRSTACK <= start && start < (USRSTACK + MAXSSIZ)) {
198 			top = round_page(USRSTACK + ptoa(vm->vm_ssize));
199 			if (end > top)
200 				end = top;
201 
202 			if (start >= end)
203 				continue;
204 #else
205 		if (start >= (vaddr_t)vm->vm_maxsaddr) {
206 			top = trunc_page(USRSTACK - ptoa(vm->vm_ssize));
207 			if (start < top)
208 				start = top;
209 
210 			if (start >= end)
211 				continue;
212 #endif
213 			flag = CORE_STACK;
214 		} else
215 			flag = CORE_DATA;
216 
217 		/*
218 		 * Set up a new core file segment.
219 		 */
220 		CORE_SETMAGIC(cseg, CORESEGMAGIC, CORE_GETMID(*chdr), flag);
221 		cseg.c_addr = start;
222 		cseg.c_size = end - start;
223 
224 		error = vn_rdwr(UIO_WRITE, vp,
225 		    (caddr_t)&cseg, chdr->c_seghdrsize,
226 		    offset, UIO_SYSSPACE, IO_UNIT, cred, NULL, p);
227 		/*
228 		 * We might get an EFAULT on objects mapped beyond
229 		 * EOF. Ignore the error.
230 		 */
231 		if (error && error != EFAULT)
232 			break;
233 
234 		offset += chdr->c_seghdrsize;
235 
236 		coffset = 0;
237 		csize = (int)cseg.c_size;
238 		do {
239 			if (p->p_siglist & sigmask(SIGKILL))
240 				return (EINTR);
241 
242 			/* Rest of the loop sleeps with lock held, so... */
243 			yield();
244 
245 			chunk = MIN(csize, MAXPHYS);
246 			error = vn_rdwr(UIO_WRITE, vp,
247 			    (caddr_t)(u_long)cseg.c_addr + coffset,
248 			    chunk, offset + coffset, UIO_USERSPACE,
249 			    IO_UNIT, cred, NULL, p);
250 			if (error)
251 				return (error);
252 
253 			coffset += chunk;
254 			csize -= chunk;
255 		} while (csize > 0);
256 		offset += cseg.c_size;
257 
258 		/* Discard the memory */
259 		uvm_unmap(map, cseg.c_addr, cseg.c_addr + cseg.c_size);
260 
261 		chdr->c_nseg++;
262 	}
263 
264 	return (error);
265 }
266 
267 int
268 uvm_coredump_walkmap(struct proc *p, void *iocookie,
269     int (*func)(struct proc *, void *, struct uvm_coredump_state *),
270     void *cookie)
271 {
272 	struct uvm_coredump_state state;
273 	struct vmspace *vm = p->p_vmspace;
274 	struct vm_map *map = &vm->vm_map;
275 	struct vm_map_entry *entry;
276 	vaddr_t top;
277 	int error;
278 
279 	RB_FOREACH(entry, uvm_map_addr, &map->addr) {
280 		state.cookie = cookie;
281 		state.prot = entry->protection;
282 		state.flags = 0;
283 
284 		/* should never happen for a user process */
285 		if (UVM_ET_ISSUBMAP(entry)) {
286 			panic("uvm_coredump: user process with submap?");
287 		}
288 
289 		if (!(entry->protection & VM_PROT_WRITE) &&
290 		    entry->start != p->p_sigcode)
291 			continue;
292 
293 		/*
294 		 * Don't dump mmaped devices.
295 		 */
296 		if (entry->object.uvm_obj != NULL &&
297 		    UVM_OBJ_IS_DEVICE(entry->object.uvm_obj))
298 			continue;
299 
300 		state.start = entry->start;
301 		state.realend = entry->end;
302 		state.end = entry->end;
303 
304 		if (state.start >= VM_MAXUSER_ADDRESS)
305 			continue;
306 
307 		if (state.end > VM_MAXUSER_ADDRESS)
308 			state.end = VM_MAXUSER_ADDRESS;
309 
310 #ifdef MACHINE_STACK_GROWS_UP
311 		if (USRSTACK <= state.start &&
312 		    state.start < (USRSTACK + MAXSSIZ)) {
313 			top = round_page(USRSTACK + ptoa(vm->vm_ssize));
314 			if (state.end > top)
315 				state.end = top;
316 
317 			if (state.start >= state.end)
318 				continue;
319 #else
320 		if (state.start >= (vaddr_t)vm->vm_maxsaddr) {
321 			top = trunc_page(USRSTACK - ptoa(vm->vm_ssize));
322 			if (state.start < top)
323 				state.start = top;
324 
325 			if (state.start >= state.end)
326 				continue;
327 #endif
328 			state.flags |= UVM_COREDUMP_STACK;
329 		}
330 
331 		error = (*func)(p, iocookie, &state);
332 		if (error)
333 			return (error);
334 	}
335 
336 	return (0);
337 }
338 
339 #endif	/* !SMALL_KERNEL */
340