1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
|
/* $OpenBSD: rdsetroot.c,v 1.7 2001/05/11 15:21:35 deraadt Exp $ */
/* $NetBSD: rdsetroot.c,v 1.2 1995/10/13 16:38:39 gwr Exp $ */
/*
* Copyright (c) 1994 Gordon W. Ross
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Copy a ramdisk image into the space reserved for it.
* Kernel variables: rd_root_size, rd_root_image
*/
#include <sys/types.h>
#include <sys/file.h>
#include <sys/mman.h>
#include <stdio.h>
#include <unistd.h>
#include <a.out.h>
extern off_t lseek();
struct exec head;
char *file;
/* Virtual addresses of the symbols we frob. */
long rd_root_image_va, rd_root_size_va;
/* Offsets relative to start of data segment. */
long rd_root_image_off, rd_root_size_off;
/* value in the location at rd_root_size_off */
int rd_root_size_val;
/* pointers to pieces of mapped file */
char *dataseg;
/* and lengths */
int data_len;
int data_off;
int data_pgoff;
void find_rd_root_image(char *);
int
main(argc,argv)
char **argv;
{
int fd, n;
int *ip;
char *cp;
if (argc < 2) {
printf("%s: missing file name\n", argv[0]);
exit(1);
}
file = argv[1];
fd = open(file, O_RDWR);
if (fd < 0) {
perror(file);
exit(1);
}
n = read(fd, &head, sizeof(head));
if (n < sizeof(head)) {
printf("%s: reading header\n", file);
exit(1);
}
if (N_BADMAG(head)) {
printf("%s: bad magic number\n", file);
exit(1);
}
#ifdef DEBUG
printf(" text: %9d\n", head.a_text);
printf(" data: %9d\n", head.a_data);
printf(" bss: %9d\n", head.a_bss);
printf(" syms: %9d\n", head.a_syms);
printf("entry: 0x%08X\n", head.a_entry);
printf("trsiz: %9d\n", head.a_trsize);
printf("drsiz: %9d\n", head.a_drsize);
#endif
if (head.a_syms <= 0) {
printf("%s: no symbols\n", file);
exit(1);
}
if (head.a_trsize ||
head.a_drsize)
{
printf("%s: has relocations\n");
exit(1);
}
find_rd_root_image(file);
/*
* Map in the whole data segment.
* The file offset needs to be page aligned.
*/
data_off = N_DATOFF(head);
#ifdef BROKEN_NMAGIC
/*
* XXX it seems that our ld has a bug when generating NMAGIC files.
* the data segment ends up one page too far into the file.
*/
if (N_GETMAGIC(head) == NMAGIC)
data_off += __LDPGSZ;
#endif
data_len = head.a_data;
/* align... */
data_pgoff = N_PAGSIZ(head) - 1;
data_pgoff &= data_off;
data_off -= data_pgoff;
data_len += data_pgoff;
/* map in in... */
dataseg = mmap(NULL, /* any address is ok */
data_len, /* length */
PROT_READ | PROT_WRITE,
MAP_SHARED,
fd, data_off);
if (dataseg == MAP_FAILED) {
printf("%s: can not map data seg\n", file);
perror(file);
exit(1);
}
dataseg += data_pgoff;
/*
* Find value in the location: rd_root_size
*/
ip = (int*) (dataseg + rd_root_size_off);
rd_root_size_val = *ip;
#ifdef DEBUG
printf("rd_root_size val: 0x%08X (%d blocks)\n",
rd_root_size_val, (rd_root_size_val >> 9));
#endif
/*
* Copy the symbol table and string table.
*/
#ifdef DEBUG
printf("copying root image...\n");
#endif
n = read(0, dataseg + rd_root_image_off,
rd_root_size_val);
if (n < 0) {
perror("read");
exit(1);
}
msync(dataseg - data_pgoff, data_len, 0);
#ifdef DEBUG
printf("...copied %d bytes\n", n);
#endif
close(fd);
exit(0);
}
/*
* Find locations of the symbols to patch.
*/
struct nlist wantsyms[] = {
{ "_rd_root_size", 0 },
{ "_rd_root_image", 0 },
{ NULL, 0 },
};
void
find_rd_root_image(file)
char *file;
{
int data_va;
int std_entry;
if (nlist(file, wantsyms)) {
printf("%s: no rd_root_image symbols?\n", file);
exit(1);
}
std_entry = N_TXTADDR(head) +
(head.a_entry & (N_PAGSIZ(head)-1));
data_va = N_DATADDR(head);
if (head.a_entry != std_entry) {
printf("%s: warning: non-standard entry point: 0x%08x\n",
file, head.a_entry);
printf("\texpecting entry=0x%X\n", std_entry);
data_va += (head.a_entry - std_entry);
}
rd_root_size_off = wantsyms[0].n_value - data_va;
rd_root_image_off = wantsyms[1].n_value - data_va;
#ifdef DEBUG
printf(".data segment va: 0x%08X\n", data_va);
printf("rd_root_size va: 0x%08X\n", wantsyms[0].n_value);
printf("rd_root_image va: 0x%08X\n", wantsyms[1].n_value);
printf("rd_root_size off: 0x%08X\n", rd_root_size_off);
printf("rd_root_image off: 0x%08X\n", rd_root_image_off);
#endif
/*
* Sanity check locations of db_* symbols
*/
if (rd_root_image_off < 0 || rd_root_image_off >= head.a_data) {
printf("%s: rd_root_image not in data segment?\n", file);
exit(1);
}
if (rd_root_size_off < 0 || rd_root_size_off >= head.a_data) {
printf("%s: rd_root_size not in data segment?\n", file);
exit(1);
}
}
|
