xref: /openbsd-src/sys/uvm/uvm_unix.c (revision 9084c3374b43b2e9a8cc7a32c22f235e1ecd6ee8)
1 /*	$OpenBSD: uvm_unix.c,v 1.52 2014/11/17 03:15:58 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. 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 #include <sys/core.h>
54 
55 #include <sys/mount.h>
56 #include <sys/syscallargs.h>
57 
58 #include <uvm/uvm.h>
59 
60 /*
61  * sys_obreak: set break
62  */
63 
64 int
65 sys_obreak(struct proc *p, void *v, register_t *retval)
66 {
67 	struct sys_obreak_args /* {
68 		syscallarg(char *) nsize;
69 	} */ *uap = v;
70 	struct vmspace *vm = p->p_vmspace;
71 	vaddr_t new, old, base;
72 	int error;
73 
74 	base = (vaddr_t)vm->vm_daddr;
75 	new = round_page((vaddr_t)SCARG(uap, nsize));
76 	if (new < base || (new - base) > p->p_rlimit[RLIMIT_DATA].rlim_cur)
77 		return (ENOMEM);
78 
79 	old = round_page(base + ptoa(vm->vm_dsize));
80 
81 	if (new == old)
82 		return (0);
83 
84 	/* grow or shrink? */
85 	if (new > old) {
86 		error = uvm_map(&vm->vm_map, &old, new - old, NULL,
87 		    UVM_UNKNOWN_OFFSET, 0,
88 		    UVM_MAPFLAG(PROT_READ | PROT_WRITE,
89 		    PROT_READ | PROT_WRITE | PROT_EXEC, UVM_INH_COPY,
90 		    POSIX_MADV_NORMAL, UVM_FLAG_AMAPPAD|UVM_FLAG_FIXED|
91 		    UVM_FLAG_OVERLAY|UVM_FLAG_COPYONW));
92 		if (error) {
93 			uprintf("sbrk: grow %ld failed, error = %d\n",
94 			    new - old, error);
95 			return (ENOMEM);
96 		}
97 		vm->vm_dsize += atop(new - old);
98 	} else {
99 		uvm_deallocate(&vm->vm_map, new, old - new);
100 		vm->vm_dsize -= atop(old - new);
101 	}
102 
103 	return (0);
104 }
105 
106 /*
107  * uvm_grow: enlarge the "stack segment" to include sp.
108  */
109 void
110 uvm_grow(struct proc *p, vaddr_t sp)
111 {
112 	struct vmspace *vm = p->p_vmspace;
113 	int si;
114 
115 	/* For user defined stacks (from sendsig). */
116 	if (sp < (vaddr_t)vm->vm_maxsaddr)
117 		return;
118 
119 	/* For common case of already allocated (from trap). */
120 #ifdef MACHINE_STACK_GROWS_UP
121 	if (sp < USRSTACK + ptoa(vm->vm_ssize))
122 #else
123 	if (sp >= USRSTACK - ptoa(vm->vm_ssize))
124 #endif
125 		return;
126 
127 	/* Really need to check vs limit and increment stack size if ok. */
128 #ifdef MACHINE_STACK_GROWS_UP
129 	si = atop(sp - USRSTACK) - vm->vm_ssize + 1;
130 #else
131 	si = atop(USRSTACK - sp) - vm->vm_ssize;
132 #endif
133 	if (vm->vm_ssize + si <= atop(p->p_rlimit[RLIMIT_STACK].rlim_cur))
134 		vm->vm_ssize += si;
135 }
136 
137 #ifndef SMALL_KERNEL
138 
139 /*
140  * uvm_coredump: dump core!
141  */
142 
143 int
144 uvm_coredump(struct proc *p, struct vnode *vp, struct ucred *cred,
145     struct core *chdr)
146 {
147 	struct vmspace *vm = p->p_vmspace;
148 	vm_map_t map = &vm->vm_map;
149 	vm_map_entry_t entry, safe;
150 	vaddr_t start, end, top;
151 	struct coreseg cseg;
152 	off_t offset, coffset;
153 	int csize, chunk, flag, error = 0;
154 
155 	offset = chdr->c_hdrsize + chdr->c_seghdrsize + chdr->c_cpusize;
156 
157 	RB_FOREACH_SAFE(entry, uvm_map_addr, &map->addr, safe) {
158 		/* should never happen for a user process */
159 		if (UVM_ET_ISSUBMAP(entry)) {
160 			panic("uvm_coredump: user process with submap?");
161 		}
162 
163 		if (!(entry->protection & PROT_WRITE) &&
164 		    entry->start != p->p_p->ps_sigcode)
165 			continue;
166 
167 		/* Don't dump mmaped devices. */
168 		if (entry->object.uvm_obj != NULL &&
169 		    UVM_OBJ_IS_DEVICE(entry->object.uvm_obj))
170 			continue;
171 
172 		start = entry->start;
173 		end = entry->end;
174 
175 		if (start >= VM_MAXUSER_ADDRESS)
176 			continue;
177 
178 		if (end > VM_MAXUSER_ADDRESS)
179 			end = VM_MAXUSER_ADDRESS;
180 
181 #ifdef MACHINE_STACK_GROWS_UP
182 		if (USRSTACK <= start && start < (USRSTACK + MAXSSIZ)) {
183 			top = round_page(USRSTACK + ptoa(vm->vm_ssize));
184 			if (end > top)
185 				end = top;
186 
187 			if (start >= end)
188 				continue;
189 #else
190 		if (start >= (vaddr_t)vm->vm_maxsaddr) {
191 			top = trunc_page(USRSTACK - ptoa(vm->vm_ssize));
192 			if (start < top)
193 				start = top;
194 
195 			if (start >= end)
196 				continue;
197 #endif
198 			flag = CORE_STACK;
199 		} else
200 			flag = CORE_DATA;
201 
202 		/* Set up a new core file segment. */
203 		CORE_SETMAGIC(cseg, CORESEGMAGIC, CORE_GETMID(*chdr), flag);
204 		cseg.c_addr = start;
205 		cseg.c_size = end - start;
206 
207 		error = vn_rdwr(UIO_WRITE, vp,
208 		    (caddr_t)&cseg, chdr->c_seghdrsize,
209 		    offset, UIO_SYSSPACE, IO_UNIT, cred, NULL, p);
210 		/*
211 		 * We might get an EFAULT on objects mapped beyond
212 		 * EOF. Ignore the error.
213 		 */
214 		if (error && error != EFAULT)
215 			break;
216 
217 		offset += chdr->c_seghdrsize;
218 
219 		coffset = 0;
220 		csize = (int)cseg.c_size;
221 		do {
222 			if (p->p_siglist & sigmask(SIGKILL))
223 				return (EINTR);
224 
225 			/* Rest of the loop sleeps with lock held, so... */
226 			yield();
227 
228 			chunk = MIN(csize, MAXPHYS);
229 			error = vn_rdwr(UIO_WRITE, vp,
230 			    (caddr_t)(u_long)cseg.c_addr + coffset,
231 			    chunk, offset + coffset, UIO_USERSPACE,
232 			    IO_UNIT, cred, NULL, p);
233 			if (error)
234 				return (error);
235 
236 			coffset += chunk;
237 			csize -= chunk;
238 		} while (csize > 0);
239 		offset += cseg.c_size;
240 
241 		/* Discard the memory */
242 		uvm_unmap(map, cseg.c_addr, cseg.c_addr + cseg.c_size);
243 
244 		chdr->c_nseg++;
245 	}
246 
247 	return (error);
248 }
249 
250 int
251 uvm_coredump_walkmap(struct proc *p, void *iocookie,
252     int (*func)(struct proc *, void *, struct uvm_coredump_state *),
253     void *cookie)
254 {
255 	struct uvm_coredump_state state;
256 	struct vmspace *vm = p->p_vmspace;
257 	struct vm_map *map = &vm->vm_map;
258 	struct vm_map_entry *entry;
259 	vaddr_t top;
260 	int error;
261 
262 	RB_FOREACH(entry, uvm_map_addr, &map->addr) {
263 		state.cookie = cookie;
264 		state.prot = entry->protection;
265 		state.flags = 0;
266 
267 		/* should never happen for a user process */
268 		if (UVM_ET_ISSUBMAP(entry)) {
269 			panic("uvm_coredump: user process with submap?");
270 		}
271 
272 		if (!(entry->protection & PROT_WRITE) &&
273 		    entry->start != p->p_p->ps_sigcode)
274 			continue;
275 
276 		/* Don't dump mmaped devices. */
277 		if (entry->object.uvm_obj != NULL &&
278 		    UVM_OBJ_IS_DEVICE(entry->object.uvm_obj))
279 			continue;
280 
281 		state.start = entry->start;
282 		state.realend = entry->end;
283 		state.end = entry->end;
284 
285 		if (state.start >= VM_MAXUSER_ADDRESS)
286 			continue;
287 
288 		if (state.end > VM_MAXUSER_ADDRESS)
289 			state.end = VM_MAXUSER_ADDRESS;
290 
291 #ifdef MACHINE_STACK_GROWS_UP
292 		if (USRSTACK <= state.start &&
293 		    state.start < (USRSTACK + MAXSSIZ)) {
294 			top = round_page(USRSTACK + ptoa(vm->vm_ssize));
295 			if (state.end > top)
296 				state.end = top;
297 
298 			if (state.start >= state.end)
299 				continue;
300 #else
301 		if (state.start >= (vaddr_t)vm->vm_maxsaddr) {
302 			top = trunc_page(USRSTACK - ptoa(vm->vm_ssize));
303 			if (state.start < top)
304 				state.start = top;
305 
306 			if (state.start >= state.end)
307 				continue;
308 #endif
309 			state.flags |= UVM_COREDUMP_STACK;
310 		}
311 
312 		error = (*func)(p, iocookie, &state);
313 		if (error)
314 			return (error);
315 	}
316 
317 	return (0);
318 }
319 
320 #endif	/* !SMALL_KERNEL */
321