1 /* Compressed section support (intended for debug sections).
2 Copyright (C) 2008-2015 Free Software Foundation, Inc.
4 This file is part of BFD, the Binary File Descriptor library.
6 This program 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.
11 This program is distributed in the hope that it will be useful,
12 but 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.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
19 MA 02110-1301, USA. */
27 #include "safe-ctype.h"
31 decompress_contents (bfd_byte *compressed_buffer,
32 bfd_size_type compressed_size,
33 bfd_byte *uncompressed_buffer,
34 bfd_size_type uncompressed_size)
39 /* It is possible the section consists of several compressed
40 buffers concatenated together, so we uncompress in a loop. */
44 strm.avail_in = compressed_size - 12;
45 strm.next_in = (Bytef*) compressed_buffer + 12;
46 strm.avail_out = uncompressed_size;
48 BFD_ASSERT (Z_OK == 0);
49 rc = inflateInit (&strm);
50 while (strm.avail_in > 0 && strm.avail_out > 0)
54 strm.next_out = ((Bytef*) uncompressed_buffer
55 + (uncompressed_size - strm.avail_out));
56 rc = inflate (&strm, Z_FINISH);
57 if (rc != Z_STREAM_END)
59 rc = inflateReset (&strm);
61 rc |= inflateEnd (&strm);
62 return rc == Z_OK && strm.avail_out == 0;
65 /* Compress data of the size specified in @var{uncompressed_size}
66 and pointed to by @var{uncompressed_buffer} using zlib and store
67 as the contents field. This function assumes the contents
68 field was allocated using bfd_malloc() or equivalent. If zlib
69 is not installed on this machine, the input is unmodified.
71 Return @code{TRUE} if the full section contents is compressed
75 bfd_compress_section_contents (bfd *abfd ATTRIBUTE_UNUSED,
76 sec_ptr sec ATTRIBUTE_UNUSED,
77 bfd_byte *uncompressed_buffer ATTRIBUTE_UNUSED,
78 bfd_size_type uncompressed_size ATTRIBUTE_UNUSED)
80 uLong compressed_size;
81 bfd_byte *compressed_buffer;
83 compressed_size = compressBound (uncompressed_size) + 12;
84 compressed_buffer = (bfd_byte *) bfd_malloc (compressed_size);
86 if (compressed_buffer == NULL)
89 if (compress ((Bytef*) compressed_buffer + 12,
91 (const Bytef*) uncompressed_buffer,
92 uncompressed_size) != Z_OK)
94 free (compressed_buffer);
95 bfd_set_error (bfd_error_bad_value);
99 /* Write the zlib header. In this case, it should be "ZLIB" followed
100 by the uncompressed section size, 8 bytes in big-endian order. */
101 memcpy (compressed_buffer, "ZLIB", 4);
102 compressed_buffer[11] = uncompressed_size; uncompressed_size >>= 8;
103 compressed_buffer[10] = uncompressed_size; uncompressed_size >>= 8;
104 compressed_buffer[9] = uncompressed_size; uncompressed_size >>= 8;
105 compressed_buffer[8] = uncompressed_size; uncompressed_size >>= 8;
106 compressed_buffer[7] = uncompressed_size; uncompressed_size >>= 8;
107 compressed_buffer[6] = uncompressed_size; uncompressed_size >>= 8;
108 compressed_buffer[5] = uncompressed_size; uncompressed_size >>= 8;
109 compressed_buffer[4] = uncompressed_size;
110 compressed_size += 12;
112 /* Free the uncompressed contents if we compress in place. */
113 if (uncompressed_buffer == sec->contents)
114 free (uncompressed_buffer);
116 sec->contents = compressed_buffer;
117 sec->size = compressed_size;
118 sec->compress_status = COMPRESS_SECTION_DONE;
122 #endif /* HAVE_ZLIB_H */
126 bfd_get_full_section_contents
129 bfd_boolean bfd_get_full_section_contents
130 (bfd *abfd, asection *section, bfd_byte **ptr);
133 Read all data from @var{section} in BFD @var{abfd}, decompress
134 if needed, and store in @var{*ptr}. If @var{*ptr} is NULL,
135 return @var{*ptr} with memory malloc'd by this function.
137 Return @code{TRUE} if the full section contents is retrieved
138 successfully. If the section has no contents then this function
139 returns @code{TRUE} but @var{*ptr} is set to NULL.
143 bfd_get_full_section_contents (bfd *abfd, sec_ptr sec, bfd_byte **ptr)
149 bfd_size_type save_size;
150 bfd_size_type save_rawsize;
151 bfd_byte *compressed_buffer;
154 if (abfd->direction != write_direction && sec->rawsize != 0)
164 switch (sec->compress_status)
166 case COMPRESS_SECTION_NONE:
169 p = (bfd_byte *) bfd_malloc (sz);
174 if (!bfd_get_section_contents (abfd, sec, p, 0, sz))
183 case DECOMPRESS_SECTION_SIZED:
185 bfd_set_error (bfd_error_invalid_operation);
188 /* Read in the full compressed section contents. */
189 compressed_buffer = (bfd_byte *) bfd_malloc (sec->compressed_size);
190 if (compressed_buffer == NULL)
192 save_rawsize = sec->rawsize;
193 save_size = sec->size;
194 /* Clear rawsize, set size to compressed size and set compress_status
195 to COMPRESS_SECTION_NONE. If the compressed size is bigger than
196 the uncompressed size, bfd_get_section_contents will fail. */
198 sec->size = sec->compressed_size;
199 sec->compress_status = COMPRESS_SECTION_NONE;
200 ret = bfd_get_section_contents (abfd, sec, compressed_buffer,
201 0, sec->compressed_size);
202 /* Restore rawsize and size. */
203 sec->rawsize = save_rawsize;
204 sec->size = save_size;
205 sec->compress_status = DECOMPRESS_SECTION_SIZED;
207 goto fail_compressed;
210 p = (bfd_byte *) bfd_malloc (sz);
212 goto fail_compressed;
214 if (!decompress_contents (compressed_buffer, sec->compressed_size, p, sz))
216 bfd_set_error (bfd_error_bad_value);
220 free (compressed_buffer);
224 free (compressed_buffer);
229 case COMPRESS_SECTION_DONE:
230 if (sec->contents == NULL)
234 p = (bfd_byte *) bfd_malloc (sz);
239 /* PR 17512; file: 5bc29788. */
240 if (p != sec->contents)
241 memcpy (p, sec->contents, sz);
251 bfd_cache_section_contents
254 void bfd_cache_section_contents
255 (asection *sec, void *contents);
258 Stash @var(contents) so any following reads of @var(sec) do
259 not need to decompress again.
263 bfd_cache_section_contents (asection *sec, void *contents)
265 if (sec->compress_status == DECOMPRESS_SECTION_SIZED)
266 sec->compress_status = COMPRESS_SECTION_DONE;
267 sec->contents = contents;
268 sec->flags |= SEC_IN_MEMORY;
274 bfd_is_section_compressed
277 bfd_boolean bfd_is_section_compressed
278 (bfd *abfd, asection *section);
281 Return @code{TRUE} if @var{section} is compressed.
285 bfd_is_section_compressed (bfd *abfd, sec_ptr sec)
287 bfd_byte compressed_buffer [12];
288 unsigned int saved = sec->compress_status;
289 bfd_boolean compressed;
291 /* Don't decompress the section. */
292 sec->compress_status = COMPRESS_SECTION_NONE;
294 /* Read the zlib header. In this case, it should be "ZLIB" followed
295 by the uncompressed section size, 8 bytes in big-endian order. */
296 compressed = (bfd_get_section_contents (abfd, sec, compressed_buffer, 0, 12)
297 && CONST_STRNEQ ((char*) compressed_buffer, "ZLIB"));
299 /* Check for the pathalogical case of a debug string section that
300 contains the string ZLIB.... as the first entry. We assume that
301 no uncompressed .debug_str section would ever be big enough to
302 have the first byte of its (big-endian) size be non-zero. */
304 && strcmp (sec->name, ".debug_str") == 0
305 && ISPRINT (compressed_buffer[4]))
308 /* Restore compress_status. */
309 sec->compress_status = saved;
315 bfd_init_section_decompress_status
318 bfd_boolean bfd_init_section_decompress_status
319 (bfd *abfd, asection *section);
322 Record compressed section size, update section size with
323 decompressed size and set compress_status to
324 DECOMPRESS_SECTION_SIZED.
326 Return @code{FALSE} if the section is not a valid compressed
327 section or zlib is not installed on this machine. Otherwise,
332 bfd_init_section_decompress_status (bfd *abfd ATTRIBUTE_UNUSED,
333 sec_ptr sec ATTRIBUTE_UNUSED)
336 bfd_set_error (bfd_error_invalid_operation);
339 bfd_byte compressed_buffer [12];
340 bfd_size_type uncompressed_size;
342 if (sec->rawsize != 0
343 || sec->contents != NULL
344 || sec->compress_status != COMPRESS_SECTION_NONE
345 || !bfd_get_section_contents (abfd, sec, compressed_buffer, 0, 12))
347 bfd_set_error (bfd_error_invalid_operation);
351 /* Read the zlib header. In this case, it should be "ZLIB" followed
352 by the uncompressed section size, 8 bytes in big-endian order. */
353 if (! CONST_STRNEQ ((char*) compressed_buffer, "ZLIB"))
355 bfd_set_error (bfd_error_wrong_format);
359 uncompressed_size = compressed_buffer[4]; uncompressed_size <<= 8;
360 uncompressed_size += compressed_buffer[5]; uncompressed_size <<= 8;
361 uncompressed_size += compressed_buffer[6]; uncompressed_size <<= 8;
362 uncompressed_size += compressed_buffer[7]; uncompressed_size <<= 8;
363 uncompressed_size += compressed_buffer[8]; uncompressed_size <<= 8;
364 uncompressed_size += compressed_buffer[9]; uncompressed_size <<= 8;
365 uncompressed_size += compressed_buffer[10]; uncompressed_size <<= 8;
366 uncompressed_size += compressed_buffer[11];
368 sec->compressed_size = sec->size;
369 sec->size = uncompressed_size;
370 sec->compress_status = DECOMPRESS_SECTION_SIZED;
378 bfd_init_section_compress_status
381 bfd_boolean bfd_init_section_compress_status
382 (bfd *abfd, asection *section);
385 If open for read, compress section, update section size with
386 compressed size and set compress_status to COMPRESS_SECTION_DONE.
388 Return @code{FALSE} if the section is not a valid compressed
389 section or zlib is not installed on this machine. Otherwise,
394 bfd_init_section_compress_status (bfd *abfd ATTRIBUTE_UNUSED,
395 sec_ptr sec ATTRIBUTE_UNUSED)
398 bfd_set_error (bfd_error_invalid_operation);
401 bfd_size_type uncompressed_size;
402 bfd_byte *uncompressed_buffer;
405 /* Error if not opened for read. */
406 if (abfd->direction != read_direction
409 || sec->contents != NULL
410 || sec->compress_status != COMPRESS_SECTION_NONE)
412 bfd_set_error (bfd_error_invalid_operation);
416 /* Read in the full section contents and compress it. */
417 uncompressed_size = sec->size;
418 uncompressed_buffer = (bfd_byte *) bfd_malloc (uncompressed_size);
419 if (!bfd_get_section_contents (abfd, sec, uncompressed_buffer,
420 0, uncompressed_size))
423 ret = bfd_compress_section_contents (abfd, sec,
427 /* PR binutils/18087: If compression didn't make
428 the section smaller, just keep it uncompressed. */
429 if (ret && uncompressed_size < sec->size)
431 free (sec->contents);
432 sec->contents = uncompressed_buffer;
433 sec->size = uncompressed_size;
434 sec->compress_status = COMPRESS_SECTION_NONE;
437 free (uncompressed_buffer);