Line data Source code
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
76 4 : main (int argc, char *argv[])
77 : {
78 : /* We use no threads here which can interfere with handling a stream. */
79 4 : (void) __fsetlocking (stdin, FSETLOCKING_BYCALLER);
80 4 : (void) __fsetlocking (stdout, FSETLOCKING_BYCALLER);
81 4 : (void) __fsetlocking (stderr, FSETLOCKING_BYCALLER);
82 :
83 : /* Set locale. */
84 4 : (void) setlocale (LC_ALL, "");
85 :
86 : /* Make sure the message catalog can be found. */
87 4 : (void) bindtextdomain (PACKAGE_TARNAME, LOCALEDIR);
88 :
89 : /* Initialize the message catalog. */
90 4 : (void) textdomain (PACKAGE_TARNAME);
91 :
92 : /* Parse and process arguments. */
93 4 : int remaining;
94 4 : (void) argp_parse (&argp, argc, argv, ARGP_IN_ORDER, &remaining, NULL);
95 :
96 : /* Tell the library which version we are expecting. */
97 4 : (void) elf_version (EV_CURRENT);
98 :
99 : /* There must at least be one more parameter specifying the archive. */
100 4 : if (remaining == argc)
101 : {
102 0 : error (0, 0, gettext ("Archive name required"));
103 0 : argp_help (&argp, stderr, ARGP_HELP_SEE, "ranlib");
104 0 : exit (EXIT_FAILURE);
105 : }
106 :
107 : /* We accept the names of multiple archives. */
108 : int status = 0;
109 4 : do
110 4 : status |= handle_file (argv[remaining]);
111 4 : while (++remaining < argc);
112 :
113 4 : return status;
114 : }
115 :
116 :
117 : static int
118 3 : copy_content (Elf *elf, int newfd, off_t off, size_t n)
119 : {
120 3 : size_t len;
121 3 : char *rawfile = elf_rawfile (elf, &len);
122 :
123 3 : assert (off + n <= len);
124 :
125 : /* Tell the kernel we will read all the pages sequentially. */
126 3 : size_t ps = sysconf (_SC_PAGESIZE);
127 3 : if (n > 2 * ps)
128 0 : posix_madvise (rawfile + (off & ~(ps - 1)), n, POSIX_MADV_SEQUENTIAL);
129 :
130 3 : 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
136 4 : handle_file (const char *fname)
137 : {
138 4 : int fd = open (fname, O_RDONLY);
139 4 : if (fd == -1)
140 : {
141 0 : error (0, errno, gettext ("cannot open '%s'"), fname);
142 0 : return 1;
143 : }
144 :
145 4 : struct stat st;
146 4 : if (fstat (fd, &st) != 0)
147 : {
148 0 : error (0, errno, gettext ("cannot stat '%s'"), fname);
149 0 : close (fd);
150 0 : return 1;
151 : }
152 :
153 : /* First we walk through the file, looking for all ELF files to
154 : collect symbols from. */
155 4 : Elf *arelf = elf_begin (fd, ELF_C_READ_MMAP, NULL);
156 4 : if (arelf == NULL)
157 : {
158 0 : error (0, 0, gettext ("cannot create ELF descriptor for '%s': %s"),
159 : fname, elf_errmsg (-1));
160 0 : close (fd);
161 0 : return 1;
162 : }
163 :
164 4 : if (elf_kind (arelf) != ELF_K_AR)
165 : {
166 0 : error (0, 0, gettext ("'%s' is no archive"), fname);
167 0 : elf_end (arelf);
168 0 : close (fd);
169 0 : return 1;
170 : }
171 :
172 4 : arlib_init ();
173 :
174 : /* Iterate over the content of the archive. */
175 4 : off_t index_off = -1;
176 4 : size_t index_size = 0;
177 4 : off_t cur_off = SARMAG;
178 4 : Elf *elf;
179 4 : Elf_Cmd cmd = ELF_C_READ_MMAP;
180 17 : while ((elf = elf_begin (fd, cmd, arelf)) != NULL)
181 : {
182 13 : Elf_Arhdr *arhdr = elf_getarhdr (elf);
183 13 : assert (arhdr != NULL);
184 :
185 : /* If this is the index, remember the location. */
186 13 : if (strcmp (arhdr->ar_name, "/") == 0)
187 : {
188 2 : index_off = elf_getaroff (elf);
189 2 : index_size = arhdr->ar_size;
190 : }
191 : else
192 : {
193 11 : arlib_add_symbols (elf, fname, arhdr->ar_name, cur_off);
194 11 : cur_off += (((arhdr->ar_size + 1) & ~((off_t) 1))
195 : + sizeof (struct ar_hdr));
196 : }
197 :
198 : /* Get next archive element. */
199 13 : cmd = elf_next (elf);
200 13 : if (elf_end (elf) != 0)
201 0 : error (0, 0, gettext ("error while freeing sub-ELF descriptor: %s"),
202 : elf_errmsg (-1));
203 : }
204 :
205 4 : arlib_finalize ();
206 :
207 : /* If the file contains no symbols we need not do anything. */
208 4 : int status = 0;
209 8 : 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 4 : || (symtab.symsnamelen == 0 && index_size != 0))
213 3 : {
214 : /* Create a new, temporary file in the same directory as the
215 : original file. */
216 3 : char tmpfname[strlen (fname) + 7];
217 6 : strcpy (stpcpy (tmpfname, fname), "XXXXXX");
218 3 : int newfd = mkstemp (tmpfname);
219 3 : if (unlikely (newfd == -1))
220 : {
221 0 : nonew:
222 0 : error (0, errno, gettext ("cannot create new file"));
223 0 : status = 1;
224 : }
225 : else
226 : {
227 : /* Create the header. */
228 3 : if (unlikely (write_retry (newfd, ARMAG, SARMAG) != SARMAG))
229 : {
230 : // XXX Use /prof/self/fd/%d ???
231 0 : nonew_unlink:
232 0 : unlink (tmpfname);
233 0 : if (newfd != -1)
234 0 : close (newfd);
235 0 : 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 3 : off_t rest_off;
242 3 : if (index_off != -1)
243 4 : rest_off = (index_off + sizeof (struct ar_hdr)
244 2 : + ((index_size + 1) & ~1ul));
245 : else
246 : rest_off = SARMAG;
247 :
248 3 : if ((symtab.symsnamelen != 0
249 2 : && ((write_retry (newfd, symtab.symsoff,
250 : symtab.symsofflen)
251 2 : != (ssize_t) symtab.symsofflen)
252 2 : || (write_retry (newfd, symtab.symsname,
253 : symtab.symsnamelen)
254 2 : != (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 3 : || (index_off > SARMAG
258 0 : && copy_content (arelf, newfd, SARMAG, index_off - SARMAG))
259 3 : || 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 3 : || fchmod (newfd, st.st_mode & ALLPERMS) != 0
263 : /* Never complain about fchown failing. */
264 6 : || (({asm ("" :: "r" (fchown (newfd, st.st_uid, st.st_gid))); }),
265 3 : close (newfd) != 0)
266 3 : || (newfd = -1, rename (tmpfname, fname) != 0))
267 0 : goto nonew_unlink;
268 : }
269 : }
270 :
271 4 : elf_end (arelf);
272 :
273 4 : arlib_fini ();
274 :
275 4 : close (fd);
276 :
277 4 : return status;
278 : }
279 :
280 :
281 : #include "debugpred.h"
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