1 /* $NetBSD: uvm_coredump.c,v 1.8 2020/02/23 15:46:43 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. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * @(#)vm_glue.c 8.6 (Berkeley) 1/5/94
37 * from: Id: uvm_glue.c,v 1.1.2.8 1998/02/07 01:16:54 chs Exp
38 *
39 *
40 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
41 * All rights reserved.
42 *
43 * Permission to use, copy, modify and distribute this software and
44 * its documentation is hereby granted, provided that both the copyright
45 * notice and this permission notice appear in all copies of the
46 * software, derivative works or modified versions, and any portions
47 * thereof, and that both notices appear in supporting documentation.
48 *
49 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
50 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
51 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
52 *
53 * Carnegie Mellon requests users of this software to return to
54 *
55 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
56 * School of Computer Science
57 * Carnegie Mellon University
58 * Pittsburgh PA 15213-3890
59 *
60 * any improvements or extensions that they make and grant Carnegie the
61 * rights to redistribute these changes.
62 */
63
64 #include <sys/cdefs.h>
65 __KERNEL_RCSID(0, "$NetBSD: uvm_coredump.c,v 1.8 2020/02/23 15:46:43 ad Exp $");
66
67 /*
68 * uvm_coredump.c: glue functions for coredump
69 */
70
71 #include <sys/param.h>
72 #include <sys/systm.h>
73 #include <sys/proc.h>
74
75 #include <uvm/uvm.h>
76
77 /*
78 * uvm_coredump_walkmap: walk a process's map for the purpose of dumping
79 * a core file.
80 * XXX: I'm not entirely sure the locking is this function is in anyway
81 * correct. If the process isn't actually stopped then the data passed
82 * to func() is at best stale, and horrid things might happen if the
83 * entry being processed is deleted (dsl).
84 */
85
86 int
uvm_coredump_walkmap(struct proc * p,int (* func)(struct uvm_coredump_state *),void * cookie)87 uvm_coredump_walkmap(struct proc *p, int (*func)(struct uvm_coredump_state *),
88 void *cookie)
89 {
90 struct uvm_coredump_state state;
91 struct vmspace *vm = p->p_vmspace;
92 struct vm_map *map = &vm->vm_map;
93 struct vm_map_entry *entry;
94 int error;
95
96 entry = NULL;
97 vm_map_lock_read(map);
98 state.end = 0;
99 for (;;) {
100 if (entry == NULL)
101 entry = map->header.next;
102 else if (!uvm_map_lookup_entry(map, state.end, &entry))
103 entry = entry->next;
104 if (entry == &map->header)
105 break;
106
107 state.cookie = cookie;
108 if (state.end > entry->start) {
109 state.start = state.end;
110 } else {
111 state.start = entry->start;
112 }
113 state.realend = entry->end;
114 state.end = entry->end;
115 state.prot = entry->protection;
116 state.flags = 0;
117
118 /*
119 * Dump the region unless one of the following is true:
120 *
121 * (1) the region has neither object nor amap behind it
122 * (ie. it has never been accessed).
123 *
124 * (2) the region has no amap and is read-only
125 * (eg. an executable text section).
126 *
127 * (3) the region's object is a device.
128 *
129 * (4) the region is unreadable by the process.
130 */
131
132 KASSERT(!UVM_ET_ISSUBMAP(entry));
133 #ifdef VM_MAXUSER_ADDRESS
134 KASSERT(state.start < VM_MAXUSER_ADDRESS);
135 KASSERT(state.end <= VM_MAXUSER_ADDRESS);
136 #endif
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, RW_READER);
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 vm_map_unlock_read(map);
192 error = (*func)(&state);
193 if (error)
194 return (error);
195 vm_map_lock_read(map);
196 }
197 vm_map_unlock_read(map);
198
199 return (0);
200 }
201
202 static int
count_segs(struct uvm_coredump_state * s)203 count_segs(struct uvm_coredump_state *s)
204 {
205 (*(int *)s->cookie)++;
206
207 return 0;
208 }
209
210 int
uvm_coredump_count_segs(struct proc * p)211 uvm_coredump_count_segs(struct proc *p)
212 {
213 int count = 0;
214
215 uvm_coredump_walkmap(p, count_segs, &count);
216 return count;
217 }
218