xref: /netbsd-src/sys/uvm/uvm_coredump.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: uvm_coredump.c,v 1.1 2008/11/19 18:36:10 ad 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  *
7  * All rights reserved.
8  *
9  * This code is derived from software contributed to Berkeley by
10  * The Mach Operating System project at Carnegie-Mellon University.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. All advertising materials mentioning features or use of this software
21  *    must display the following acknowledgement:
22  *	This product includes software developed by Charles D. Cranor,
23  *      Washington University, the University of California, Berkeley and
24  *      its contributors.
25  * 4. Neither the name of the University nor the names of its contributors
26  *    may be used to endorse or promote products derived from this software
27  *    without specific prior written permission.
28  *
29  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
30  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
31  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
32  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
33  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
34  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
35  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
37  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
38  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39  * SUCH DAMAGE.
40  *
41  *	@(#)vm_glue.c	8.6 (Berkeley) 1/5/94
42  * from: Id: uvm_glue.c,v 1.1.2.8 1998/02/07 01:16:54 chs Exp
43  *
44  *
45  * Copyright (c) 1987, 1990 Carnegie-Mellon University.
46  * All rights reserved.
47  *
48  * Permission to use, copy, modify and distribute this software and
49  * its documentation is hereby granted, provided that both the copyright
50  * notice and this permission notice appear in all copies of the
51  * software, derivative works or modified versions, and any portions
52  * thereof, and that both notices appear in supporting documentation.
53  *
54  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
55  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
56  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
57  *
58  * Carnegie Mellon requests users of this software to return to
59  *
60  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
61  *  School of Computer Science
62  *  Carnegie Mellon University
63  *  Pittsburgh PA 15213-3890
64  *
65  * any improvements or extensions that they make and grant Carnegie the
66  * rights to redistribute these changes.
67  */
68 
69 #include <sys/cdefs.h>
70 __KERNEL_RCSID(0, "$NetBSD: uvm_coredump.c,v 1.1 2008/11/19 18:36:10 ad Exp $");
71 
72 /*
73  * uvm_coredump.c: glue functions for coredump
74  */
75 
76 #include <sys/param.h>
77 #include <sys/systm.h>
78 #include <sys/proc.h>
79 
80 #include <uvm/uvm.h>
81 
82 /*
83  * uvm_coredump_walkmap: walk a process's map for the purpose of dumping
84  * a core file.
85  */
86 
87 int
88 uvm_coredump_walkmap(struct proc *p, void *iocookie,
89     int (*func)(struct proc *, void *, struct uvm_coredump_state *),
90     void *cookie)
91 {
92 	struct uvm_coredump_state state;
93 	struct vmspace *vm = p->p_vmspace;
94 	struct vm_map *map = &vm->vm_map;
95 	struct vm_map_entry *entry;
96 	int error;
97 
98 	entry = NULL;
99 	vm_map_lock_read(map);
100 	state.end = 0;
101 	for (;;) {
102 		if (entry == NULL)
103 			entry = map->header.next;
104 		else if (!uvm_map_lookup_entry(map, state.end, &entry))
105 			entry = entry->next;
106 		if (entry == &map->header)
107 			break;
108 
109 		state.cookie = cookie;
110 		if (state.end > entry->start) {
111 			state.start = state.end;
112 		} else {
113 			state.start = entry->start;
114 		}
115 		state.realend = entry->end;
116 		state.end = entry->end;
117 		state.prot = entry->protection;
118 		state.flags = 0;
119 
120 		/*
121 		 * Dump the region unless one of the following is true:
122 		 *
123 		 * (1) the region has neither object nor amap behind it
124 		 *     (ie. it has never been accessed).
125 		 *
126 		 * (2) the region has no amap and is read-only
127 		 *     (eg. an executable text section).
128 		 *
129 		 * (3) the region's object is a device.
130 		 *
131 		 * (4) the region is unreadable by the process.
132 		 */
133 
134 		KASSERT(!UVM_ET_ISSUBMAP(entry));
135 		KASSERT(state.start < VM_MAXUSER_ADDRESS);
136 		KASSERT(state.end <= VM_MAXUSER_ADDRESS);
137 		if (entry->object.uvm_obj == NULL &&
138 		    entry->aref.ar_amap == NULL) {
139 			state.realend = state.start;
140 		} else if ((entry->protection & VM_PROT_WRITE) == 0 &&
141 		    entry->aref.ar_amap == NULL) {
142 			state.realend = state.start;
143 		} else if (entry->object.uvm_obj != NULL &&
144 		    UVM_OBJ_IS_DEVICE(entry->object.uvm_obj)) {
145 			state.realend = state.start;
146 		} else if ((entry->protection & VM_PROT_READ) == 0) {
147 			state.realend = state.start;
148 		} else {
149 			if (state.start >= (vaddr_t)vm->vm_maxsaddr)
150 				state.flags |= UVM_COREDUMP_STACK;
151 
152 			/*
153 			 * If this an anonymous entry, only dump instantiated
154 			 * pages.
155 			 */
156 			if (entry->object.uvm_obj == NULL) {
157 				vaddr_t end;
158 
159 				amap_lock(entry->aref.ar_amap);
160 				for (end = state.start;
161 				     end < state.end; end += PAGE_SIZE) {
162 					struct vm_anon *anon;
163 					anon = amap_lookup(&entry->aref,
164 					    end - entry->start);
165 					/*
166 					 * If we have already encountered an
167 					 * uninstantiated page, stop at the
168 					 * first instantied page.
169 					 */
170 					if (anon != NULL &&
171 					    state.realend != state.end) {
172 						state.end = end;
173 						break;
174 					}
175 
176 					/*
177 					 * If this page is the first
178 					 * uninstantiated page, mark this as
179 					 * the real ending point.  Continue to
180 					 * counting uninstantiated pages.
181 					 */
182 					if (anon == NULL &&
183 					    state.realend == state.end) {
184 						state.realend = end;
185 					}
186 				}
187 				amap_unlock(entry->aref.ar_amap);
188 			}
189 		}
190 
191 
192 		vm_map_unlock_read(map);
193 		error = (*func)(p, iocookie, &state);
194 		if (error)
195 			return (error);
196 		vm_map_lock_read(map);
197 	}
198 	vm_map_unlock_read(map);
199 
200 	return (0);
201 }
202