1 /* Generate an index to speed access to archives.
2 Copyright (C) 2005-2012 Red Hat, Inc.
3 This file is part of elfutils.
4 Written by Ulrich Drepper <drepper@redhat.com>, 2005.
5
6 This file is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
10
11 elfutils is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>. */
18
19 #ifdef HAVE_CONFIG_H
20 # include <config.h>
21 #endif
22
23 #include <ar.h>
24 #include <argp.h>
25 #include <assert.h>
26 #include <errno.h>
27 #include <fcntl.h>
28 #include <gelf.h>
29 #include <libintl.h>
30 #include <locale.h>
31 #include <obstack.h>
32 #include <stdlib.h>
33 #include <stdio.h>
34 #include <stdio_ext.h>
35 #include <unistd.h>
36 #include <sys/mman.h>
37 #include <sys/stat.h>
38
39 #include <system.h>
40 #include <printversion.h>
41
42 #include "arlib.h"
43
44
45 /* Prototypes for local functions. */
46 static int handle_file (const char *fname);
47
48
49 /* Name and version of program. */
50 ARGP_PROGRAM_VERSION_HOOK_DEF = print_version;
51
52 /* Bug report address. */
53 ARGP_PROGRAM_BUG_ADDRESS_DEF = PACKAGE_BUGREPORT;
54
55
56 /* Definitions of arguments for argp functions. */
57 static const struct argp_option options[] =
58 {
59 { NULL, 0, NULL, 0, NULL, 0 }
60 };
61
62 /* Short description of program. */
63 static const char doc[] = N_("Generate an index to speed access to archives.");
64
65 /* Strings for arguments in help texts. */
66 static const char args_doc[] = N_("ARCHIVE");
67
68 /* Data structure to communicate with argp functions. */
69 static const struct argp argp =
70 {
71 options, NULL, args_doc, doc, arlib_argp_children, NULL, NULL
72 };
73
74
75 int
main(int argc,char * argv[])76 main (int argc, char *argv[])
77 {
78 /* We use no threads here which can interfere with handling a stream. */
79 (void) __fsetlocking (stdin, FSETLOCKING_BYCALLER);
80 (void) __fsetlocking (stdout, FSETLOCKING_BYCALLER);
81 (void) __fsetlocking (stderr, FSETLOCKING_BYCALLER);
82
83 /* Set locale. */
84 (void) setlocale (LC_ALL, "");
85
86 /* Make sure the message catalog can be found. */
87 (void) bindtextdomain (PACKAGE_TARNAME, LOCALEDIR);
88
89 /* Initialize the message catalog. */
90 (void) textdomain (PACKAGE_TARNAME);
91
92 /* Parse and process arguments. */
93 int remaining;
94 (void) argp_parse (&argp, argc, argv, ARGP_IN_ORDER, &remaining, NULL);
95
96 /* Tell the library which version we are expecting. */
97 (void) elf_version (EV_CURRENT);
98
99 /* There must at least be one more parameter specifying the archive. */
100 if (remaining == argc)
101 {
102 error (0, 0, gettext ("Archive name required"));
103 argp_help (&argp, stderr, ARGP_HELP_SEE, "ranlib");
104 exit (EXIT_FAILURE);
105 }
106
107 /* We accept the names of multiple archives. */
108 int status = 0;
109 do
110 status |= handle_file (argv[remaining]);
111 while (++remaining < argc);
112
113 return status;
114 }
115
116
117 static int
copy_content(Elf * elf,int newfd,off_t off,size_t n)118 copy_content (Elf *elf, int newfd, off_t off, size_t n)
119 {
120 size_t len;
121 char *rawfile = elf_rawfile (elf, &len);
122
123 assert (off + n <= len);
124
125 /* Tell the kernel we will read all the pages sequentially. */
126 size_t ps = sysconf (_SC_PAGESIZE);
127 if (n > 2 * ps)
128 posix_madvise (rawfile + (off & ~(ps - 1)), n, POSIX_MADV_SEQUENTIAL);
129
130 return write_retry (newfd, rawfile + off, n) != (ssize_t) n;
131 }
132
133
134 /* Handle a file given on the command line. */
135 static int
handle_file(const char * fname)136 handle_file (const char *fname)
137 {
138 int fd = open (fname, O_RDONLY);
139 if (fd == -1)
140 {
141 error (0, errno, gettext ("cannot open '%s'"), fname);
142 return 1;
143 }
144
145 struct stat st;
146 if (fstat (fd, &st) != 0)
147 {
148 error (0, errno, gettext ("cannot stat '%s'"), fname);
149 close (fd);
150 return 1;
151 }
152
153 /* First we walk through the file, looking for all ELF files to
154 collect symbols from. */
155 Elf *arelf = elf_begin (fd, ELF_C_READ_MMAP, NULL);
156 if (arelf == NULL)
157 {
158 error (0, 0, gettext ("cannot create ELF descriptor for '%s': %s"),
159 fname, elf_errmsg (-1));
160 close (fd);
161 return 1;
162 }
163
164 if (elf_kind (arelf) != ELF_K_AR)
165 {
166 error (0, 0, gettext ("'%s' is no archive"), fname);
167 elf_end (arelf);
168 close (fd);
169 return 1;
170 }
171
172 arlib_init ();
173
174 /* Iterate over the content of the archive. */
175 off_t index_off = -1;
176 size_t index_size = 0;
177 off_t cur_off = SARMAG;
178 Elf *elf;
179 Elf_Cmd cmd = ELF_C_READ_MMAP;
180 while ((elf = elf_begin (fd, cmd, arelf)) != NULL)
181 {
182 Elf_Arhdr *arhdr = elf_getarhdr (elf);
183 assert (arhdr != NULL);
184
185 /* If this is the index, remember the location. */
186 if (strcmp (arhdr->ar_name, "/") == 0)
187 {
188 index_off = elf_getaroff (elf);
189 index_size = arhdr->ar_size;
190 }
191 else
192 {
193 arlib_add_symbols (elf, fname, arhdr->ar_name, cur_off);
194 cur_off += (((arhdr->ar_size + 1) & ~((off_t) 1))
195 + sizeof (struct ar_hdr));
196 }
197
198 /* Get next archive element. */
199 cmd = elf_next (elf);
200 if (elf_end (elf) != 0)
201 error (0, 0, gettext ("error while freeing sub-ELF descriptor: %s"),
202 elf_errmsg (-1));
203 }
204
205 arlib_finalize ();
206
207 /* If the file contains no symbols we need not do anything. */
208 int status = 0;
209 if (symtab.symsnamelen != 0
210 /* We have to rewrite the file also if it initially had an index
211 but now does not need one anymore. */
212 || (symtab.symsnamelen == 0 && index_size != 0))
213 {
214 /* Create a new, temporary file in the same directory as the
215 original file. */
216 char tmpfname[strlen (fname) + 7];
217 strcpy (stpcpy (tmpfname, fname), "XXXXXX");
218 int newfd = mkstemp (tmpfname);
219 if (unlikely (newfd == -1))
220 {
221 nonew:
222 error (0, errno, gettext ("cannot create new file"));
223 status = 1;
224 }
225 else
226 {
227 /* Create the header. */
228 if (unlikely (write_retry (newfd, ARMAG, SARMAG) != SARMAG))
229 {
230 // XXX Use /prof/self/fd/%d ???
231 nonew_unlink:
232 unlink (tmpfname);
233 if (newfd != -1)
234 close (newfd);
235 goto nonew;
236 }
237
238 /* Create the new file. There are three parts as far we are
239 concerned: 1. original context before the index, 2. the
240 new index, 3. everything after the new index. */
241 off_t rest_off;
242 if (index_off != -1)
243 rest_off = (index_off + sizeof (struct ar_hdr)
244 + ((index_size + 1) & ~1ul));
245 else
246 rest_off = SARMAG;
247
248 if ((symtab.symsnamelen != 0
249 && ((write_retry (newfd, symtab.symsoff,
250 symtab.symsofflen)
251 != (ssize_t) symtab.symsofflen)
252 || (write_retry (newfd, symtab.symsname,
253 symtab.symsnamelen)
254 != (ssize_t) symtab.symsnamelen)))
255 /* Even if the original file had content before the
256 symbol table, we write it in the correct order. */
257 || (index_off > SARMAG
258 && copy_content (arelf, newfd, SARMAG, index_off - SARMAG))
259 || copy_content (arelf, newfd, rest_off, st.st_size - rest_off)
260 /* Set the mode of the new file to the same values the
261 original file has. */
262 || fchmod (newfd, st.st_mode & ALLPERMS) != 0
263 /* Never complain about fchown failing. */
264 || (({asm ("" :: "r" (fchown (newfd, st.st_uid, st.st_gid))); }),
265 close (newfd) != 0)
266 || (newfd = -1, rename (tmpfname, fname) != 0))
267 goto nonew_unlink;
268 }
269 }
270
271 elf_end (arelf);
272
273 arlib_fini ();
274
275 close (fd);
276
277 return status;
278 }
279
280
281 #include "debugpred.h"
282