1 /* |
|
2 * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved. |
|
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
|
4 * |
|
5 * This code is free software; you can redistribute it and/or modify it |
|
6 * under the terms of the GNU General Public License version 2 only, as |
|
7 * published by the Free Software Foundation. |
|
8 * |
|
9 * This code is distributed in the hope that it will be useful, but WITHOUT |
|
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
|
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
|
12 * version 2 for more details (a copy is included in the LICENSE file that |
|
13 * accompanied this code). |
|
14 * |
|
15 * You should have received a copy of the GNU General Public License version |
|
16 * 2 along with this work; if not, write to the Free Software Foundation, |
|
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
|
18 * |
|
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
|
20 * or visit www.oracle.com if you need additional information or have any |
|
21 * questions. |
|
22 * |
|
23 */ |
|
24 |
|
25 /* |
|
26 * Name: add_gnu_debuglink.c |
|
27 * |
|
28 * Description: Add a ".gnu_debuglink" section that refers to the specified |
|
29 * debug_info_path to the specified ELF object. |
|
30 * |
|
31 * This program is adapted from the example program shown on the |
|
32 * elf(3elf) man page and from code from the Solaris compiler |
|
33 * driver. |
|
34 */ |
|
35 |
|
36 /* |
|
37 * needed to define SHF_EXCLUDE |
|
38 */ |
|
39 #define ELF_TARGET_ALL |
|
40 |
|
41 #include <fcntl.h> |
|
42 #include <stdio.h> |
|
43 #include <libelf.h> |
|
44 #include <stdlib.h> |
|
45 #include <string.h> |
|
46 #include <unistd.h> |
|
47 |
|
48 static void failure(void); |
|
49 static unsigned int gnu_debuglink_crc32(unsigned int crc, unsigned char *buf, |
|
50 size_t len); |
|
51 |
|
52 void |
|
53 main(int argc, char ** argv) { |
|
54 /* new ELF section name */ |
|
55 static char SEC_NAME[] = ".gnu_debuglink"; |
|
56 |
|
57 unsigned char buffer[8 * 1024]; /* I/O buffer */ |
|
58 int buffer_len; /* buffer length */ |
|
59 char * debug_info_path; /* debug info path */ |
|
60 void * ehdr; /* ELF header */ |
|
61 Elf * elf; /* ELF descriptor */ |
|
62 char * elf_ident; /* ELF identity string */ |
|
63 char * elf_obj; /* elf_obj file */ |
|
64 int fd; /* descriptor for files */ |
|
65 unsigned int file_crc = 0; /* CRC for debug info file */ |
|
66 int is_elfclass64; /* is an ELFCLASS64 file? */ |
|
67 Elf_Data * link_dat; /* ELF data for new debug info link */ |
|
68 Elf_Data * name_dat; /* ELF data for new section name */ |
|
69 Elf_Scn * new_scn; /* new ELF section descriptor */ |
|
70 void * new_shdr; /* new ELF section header */ |
|
71 Elf_Scn * scn; /* ELF section descriptor */ |
|
72 void * shdr; /* ELF section header */ |
|
73 |
|
74 if (argc != 3) { |
|
75 (void) fprintf(stderr, "Usage: %s debug_info_path elf_obj\n", argv[0]); |
|
76 exit(2); |
|
77 } |
|
78 |
|
79 debug_info_path = argv[1]; /* save for later */ |
|
80 if ((fd = open(debug_info_path, O_RDONLY)) == -1) { |
|
81 (void) fprintf(stderr, "%s: cannot open file.\n", debug_info_path); |
|
82 exit(3); |
|
83 } |
|
84 |
|
85 (void) printf("Computing CRC for '%s'\n", debug_info_path); |
|
86 (void) fflush(stdout); |
|
87 /* compute CRC for the debug info file */ |
|
88 for (;;) { |
|
89 int len = read(fd, buffer, sizeof buffer); |
|
90 if (len <= 0) { |
|
91 break; |
|
92 } |
|
93 file_crc = gnu_debuglink_crc32(file_crc, buffer, len); |
|
94 } |
|
95 (void) close(fd); |
|
96 |
|
97 /* open the elf_obj */ |
|
98 elf_obj = argv[2]; |
|
99 if ((fd = open(elf_obj, O_RDWR)) == -1) { |
|
100 (void) fprintf(stderr, "%s: cannot open file.\n", elf_obj); |
|
101 exit(4); |
|
102 } |
|
103 |
|
104 (void) printf("Opening '%s' for update\n", elf_obj); |
|
105 (void) fflush(stdout); |
|
106 (void) elf_version(EV_CURRENT); /* coordinate ELF versions */ |
|
107 |
|
108 /* obtain the ELF descriptors from the input file */ |
|
109 if ((elf = elf_begin(fd, ELF_C_RDWR, NULL)) == NULL) { |
|
110 failure(); |
|
111 } |
|
112 |
|
113 /* determine if ELFCLASS64 or not? */ |
|
114 elf_ident = elf_getident(elf, NULL); |
|
115 is_elfclass64 = (elf_ident[EI_CLASS] == ELFCLASS64); |
|
116 |
|
117 /* get the ELF header */ |
|
118 if (is_elfclass64) { |
|
119 ehdr = elf64_getehdr(elf); |
|
120 } else { |
|
121 ehdr = elf32_getehdr(elf); |
|
122 } |
|
123 if (ehdr == NULL) { |
|
124 failure(); |
|
125 } |
|
126 |
|
127 /* get the ELF section descriptor */ |
|
128 if (is_elfclass64) { |
|
129 scn = elf_getscn(elf, ((Elf64_Ehdr *) ehdr)->e_shstrndx); |
|
130 } else { |
|
131 scn = elf_getscn(elf, ((Elf32_Ehdr *) ehdr)->e_shstrndx); |
|
132 } |
|
133 if (scn == NULL) { |
|
134 failure(); |
|
135 } |
|
136 |
|
137 /* get the section header */ |
|
138 if (is_elfclass64) { |
|
139 shdr = elf64_getshdr(scn); |
|
140 } else { |
|
141 shdr = elf32_getshdr(scn); |
|
142 } |
|
143 if (shdr == NULL) { |
|
144 failure(); |
|
145 } |
|
146 |
|
147 (void) printf("Adding ELF data for new section name\n"); |
|
148 (void) fflush(stdout); |
|
149 name_dat = elf_newdata(scn); |
|
150 name_dat->d_buf = (void *) SEC_NAME; |
|
151 if (is_elfclass64) { |
|
152 name_dat->d_off = ((Elf64_Shdr *) shdr)->sh_size + 1; |
|
153 } else { |
|
154 name_dat->d_off = ((Elf32_Shdr *) shdr)->sh_size + 1; |
|
155 } |
|
156 name_dat->d_align = 1; |
|
157 name_dat->d_size = strlen(SEC_NAME) + 1; |
|
158 |
|
159 new_scn = elf_newscn(elf); |
|
160 |
|
161 if (is_elfclass64) { |
|
162 new_shdr = elf64_getshdr(new_scn); |
|
163 ((Elf64_Shdr *) new_shdr)->sh_flags = SHF_EXCLUDE; |
|
164 ((Elf64_Shdr *) new_shdr)->sh_type = SHT_PROGBITS; |
|
165 ((Elf64_Shdr *) new_shdr)->sh_name = ((Elf64_Shdr *) shdr)->sh_size; |
|
166 ((Elf64_Shdr *) new_shdr)->sh_addralign = 1; |
|
167 ((Elf64_Shdr *) shdr)->sh_size += (strlen(SEC_NAME) + 1); |
|
168 } else { |
|
169 new_shdr = elf32_getshdr(new_scn); |
|
170 ((Elf32_Shdr *) new_shdr)->sh_flags = SHF_EXCLUDE; |
|
171 ((Elf32_Shdr *) new_shdr)->sh_type = SHT_PROGBITS; |
|
172 ((Elf32_Shdr *) new_shdr)->sh_name = ((Elf32_Shdr *) shdr)->sh_size; |
|
173 ((Elf32_Shdr *) new_shdr)->sh_addralign = 1; |
|
174 ((Elf32_Shdr *) shdr)->sh_size += (strlen(SEC_NAME) + 1); |
|
175 } |
|
176 |
|
177 (void) printf("Adding ELF data for debug_info_path value\n"); |
|
178 (void) fflush(stdout); |
|
179 (void) memset(buffer, 0, sizeof buffer); |
|
180 buffer_len = strlen(debug_info_path) + 1; /* +1 for NUL */ |
|
181 (void) strncpy((char *) buffer, debug_info_path, buffer_len); |
|
182 if (buffer_len % 4 != 0) { |
|
183 /* not on a 4 byte boundary so pad to the next one */ |
|
184 buffer_len += (4 - buffer_len % 4); |
|
185 } |
|
186 /* save the CRC */ |
|
187 (void) memcpy(&buffer[buffer_len], &file_crc, sizeof file_crc); |
|
188 buffer_len += sizeof file_crc; |
|
189 |
|
190 link_dat = elf_newdata(new_scn); |
|
191 link_dat->d_type = ELF_T_BYTE; |
|
192 link_dat->d_size = buffer_len; |
|
193 link_dat->d_buf = buffer; |
|
194 link_dat->d_align = 1; |
|
195 |
|
196 (void) printf("Saving updates to '%s'\n", elf_obj); |
|
197 (void) fflush(stdout); |
|
198 (void) elf_update(elf, ELF_C_NULL); /* recalc ELF memory structures */ |
|
199 (void) elf_update(elf, ELF_C_WRITE); /* write out changes to ELF obj */ |
|
200 (void) elf_end(elf); /* done with ELF obj */ |
|
201 (void) close(fd); |
|
202 |
|
203 (void) printf("Done updating '%s'\n", elf_obj); |
|
204 (void) fflush(stdout); |
|
205 exit(0); |
|
206 } /* end main */ |
|
207 |
|
208 |
|
209 static void |
|
210 failure() { |
|
211 (void) fprintf(stderr, "%s\n", elf_errmsg(elf_errno())); |
|
212 exit(5); |
|
213 } |
|
214 |
|
215 |
|
216 /* |
|
217 * The CRC used in gnu_debuglink, retrieved from |
|
218 * http://sourceware.org/gdb/current/onlinedocs/gdb/Separate-Debug-Files.html#Separate-Debug-Files. |
|
219 */ |
|
220 |
|
221 static unsigned int |
|
222 gnu_debuglink_crc32(unsigned int crc, unsigned char *buf, size_t len) { |
|
223 static const unsigned int crc32_table[256] = { |
|
224 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, |
|
225 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, |
|
226 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, |
|
227 0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, |
|
228 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, |
|
229 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, |
|
230 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, |
|
231 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, |
|
232 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, |
|
233 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a, |
|
234 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, |
|
235 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, |
|
236 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, |
|
237 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, |
|
238 0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e, |
|
239 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01, |
|
240 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, |
|
241 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950, |
|
242 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, |
|
243 0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, |
|
244 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, |
|
245 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, |
|
246 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010, |
|
247 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, |
|
248 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, |
|
249 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, |
|
250 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, |
|
251 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, |
|
252 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344, |
|
253 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, |
|
254 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, |
|
255 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, |
|
256 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, |
|
257 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c, |
|
258 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, |
|
259 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, |
|
260 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, |
|
261 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, |
|
262 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c, |
|
263 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, |
|
264 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, |
|
265 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242, |
|
266 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, |
|
267 0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, |
|
268 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278, |
|
269 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, |
|
270 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66, |
|
271 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, |
|
272 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, |
|
273 0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, |
|
274 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, |
|
275 0x2d02ef8d |
|
276 }; |
|
277 |
|
278 unsigned char *end; |
|
279 |
|
280 crc = ~crc & 0xffffffff; |
|
281 for (end = buf + len; buf < end; ++buf) { |
|
282 crc = crc32_table[(crc ^ *buf) & 0xff] ^ (crc >> 8); |
|
283 } |
|
284 return ~crc & 0xffffffff; |
|
285 } |
|