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;
68 bfd_compress_section_contents
71 bfd_boolean bfd_compress_section_contents
72 (bfd *abfd, asection *section, bfd_byte *uncompressed_buffer,
73 bfd_size_type uncompressed_size);
77 Compress data of the size specified in @var{uncompressed_size}
78 and pointed to by @var{uncompressed_buffer} using zlib and store
79 as the contents field. This function assumes the contents
80 field was allocated using bfd_malloc() or equivalent. If zlib
81 is not installed on this machine, the input is unmodified.
83 Return @code{TRUE} if the full section contents is compressed
88 bfd_compress_section_contents (bfd *abfd ATTRIBUTE_UNUSED,
89 sec_ptr sec ATTRIBUTE_UNUSED,
90 bfd_byte *uncompressed_buffer ATTRIBUTE_UNUSED,
91 bfd_size_type uncompressed_size ATTRIBUTE_UNUSED)
94 bfd_set_error (bfd_error_invalid_operation);
97 uLong compressed_size;
98 bfd_byte *compressed_buffer;
100 compressed_size = compressBound (uncompressed_size) + 12;
101 compressed_buffer = (bfd_byte *) bfd_malloc (compressed_size);
103 if (compressed_buffer == NULL)
106 if (compress ((Bytef*) compressed_buffer + 12,
108 (const Bytef*) uncompressed_buffer,
109 uncompressed_size) != Z_OK)
111 free (compressed_buffer);
112 bfd_set_error (bfd_error_bad_value);
116 /* Write the zlib header. In this case, it should be "ZLIB" followed
117 by the uncompressed section size, 8 bytes in big-endian order. */
118 memcpy (compressed_buffer, "ZLIB", 4);
119 compressed_buffer[11] = uncompressed_size; uncompressed_size >>= 8;
120 compressed_buffer[10] = uncompressed_size; uncompressed_size >>= 8;
121 compressed_buffer[9] = uncompressed_size; uncompressed_size >>= 8;
122 compressed_buffer[8] = uncompressed_size; uncompressed_size >>= 8;
123 compressed_buffer[7] = uncompressed_size; uncompressed_size >>= 8;
124 compressed_buffer[6] = uncompressed_size; uncompressed_size >>= 8;
125 compressed_buffer[5] = uncompressed_size; uncompressed_size >>= 8;
126 compressed_buffer[4] = uncompressed_size;
127 compressed_size += 12;
129 /* Free the uncompressed contents if we compress in place. */
130 if (uncompressed_buffer == sec->contents)
131 free (uncompressed_buffer);
133 sec->contents = compressed_buffer;
134 sec->size = compressed_size;
135 sec->compress_status = COMPRESS_SECTION_DONE;
138 #endif /* HAVE_ZLIB_H */
143 bfd_get_full_section_contents
146 bfd_boolean bfd_get_full_section_contents
147 (bfd *abfd, asection *section, bfd_byte **ptr);
150 Read all data from @var{section} in BFD @var{abfd}, decompress
151 if needed, and store in @var{*ptr}. If @var{*ptr} is NULL,
152 return @var{*ptr} with memory malloc'd by this function.
154 Return @code{TRUE} if the full section contents is retrieved
155 successfully. If the section has no contents then this function
156 returns @code{TRUE} but @var{*ptr} is set to NULL.
160 bfd_get_full_section_contents (bfd *abfd, sec_ptr sec, bfd_byte **ptr)
166 bfd_size_type save_size;
167 bfd_size_type save_rawsize;
168 bfd_byte *compressed_buffer;
171 if (abfd->direction != write_direction && sec->rawsize != 0)
181 switch (sec->compress_status)
183 case COMPRESS_SECTION_NONE:
186 p = (bfd_byte *) bfd_malloc (sz);
191 if (!bfd_get_section_contents (abfd, sec, p, 0, sz))
200 case DECOMPRESS_SECTION_SIZED:
202 bfd_set_error (bfd_error_invalid_operation);
205 /* Read in the full compressed section contents. */
206 compressed_buffer = (bfd_byte *) bfd_malloc (sec->compressed_size);
207 if (compressed_buffer == NULL)
209 save_rawsize = sec->rawsize;
210 save_size = sec->size;
211 /* Clear rawsize, set size to compressed size and set compress_status
212 to COMPRESS_SECTION_NONE. If the compressed size is bigger than
213 the uncompressed size, bfd_get_section_contents will fail. */
215 sec->size = sec->compressed_size;
216 sec->compress_status = COMPRESS_SECTION_NONE;
217 ret = bfd_get_section_contents (abfd, sec, compressed_buffer,
218 0, sec->compressed_size);
219 /* Restore rawsize and size. */
220 sec->rawsize = save_rawsize;
221 sec->size = save_size;
222 sec->compress_status = DECOMPRESS_SECTION_SIZED;
224 goto fail_compressed;
227 p = (bfd_byte *) bfd_malloc (sz);
229 goto fail_compressed;
231 if (!decompress_contents (compressed_buffer, sec->compressed_size, p, sz))
233 bfd_set_error (bfd_error_bad_value);
237 free (compressed_buffer);
241 free (compressed_buffer);
246 case COMPRESS_SECTION_DONE:
247 if (sec->contents == NULL)
251 p = (bfd_byte *) bfd_malloc (sz);
256 /* PR 17512; file: 5bc29788. */
257 if (p != sec->contents)
258 memcpy (p, sec->contents, sz);
268 bfd_cache_section_contents
271 void bfd_cache_section_contents
272 (asection *sec, void *contents);
275 Stash @var(contents) so any following reads of @var(sec) do
276 not need to decompress again.
280 bfd_cache_section_contents (asection *sec, void *contents)
282 if (sec->compress_status == DECOMPRESS_SECTION_SIZED)
283 sec->compress_status = COMPRESS_SECTION_DONE;
284 sec->contents = contents;
285 sec->flags |= SEC_IN_MEMORY;
291 bfd_is_section_compressed
294 bfd_boolean bfd_is_section_compressed
295 (bfd *abfd, asection *section);
298 Return @code{TRUE} if @var{section} is compressed.
302 bfd_is_section_compressed (bfd *abfd, sec_ptr sec)
304 bfd_byte compressed_buffer [12];
305 unsigned int saved = sec->compress_status;
306 bfd_boolean compressed;
308 /* Don't decompress the section. */
309 sec->compress_status = COMPRESS_SECTION_NONE;
311 /* Read the zlib header. In this case, it should be "ZLIB" followed
312 by the uncompressed section size, 8 bytes in big-endian order. */
313 compressed = (bfd_get_section_contents (abfd, sec, compressed_buffer, 0, 12)
314 && CONST_STRNEQ ((char*) compressed_buffer, "ZLIB"));
316 /* Check for the pathalogical case of a debug string section that
317 contains the string ZLIB.... as the first entry. We assume that
318 no uncompressed .debug_str section would ever be big enough to
319 have the first byte of its (big-endian) size be non-zero. */
321 && strcmp (sec->name, ".debug_str") == 0
322 && ISPRINT (compressed_buffer[4]))
325 /* Restore compress_status. */
326 sec->compress_status = saved;
332 bfd_init_section_decompress_status
335 bfd_boolean bfd_init_section_decompress_status
336 (bfd *abfd, asection *section);
339 Record compressed section size, update section size with
340 decompressed size and set compress_status to
341 DECOMPRESS_SECTION_SIZED.
343 Return @code{FALSE} if the section is not a valid compressed
344 section or zlib is not installed on this machine. Otherwise,
349 bfd_init_section_decompress_status (bfd *abfd ATTRIBUTE_UNUSED,
350 sec_ptr sec ATTRIBUTE_UNUSED)
353 bfd_set_error (bfd_error_invalid_operation);
356 bfd_byte compressed_buffer [12];
357 bfd_size_type uncompressed_size;
359 if (sec->rawsize != 0
360 || sec->contents != NULL
361 || sec->compress_status != COMPRESS_SECTION_NONE
362 || !bfd_get_section_contents (abfd, sec, compressed_buffer, 0, 12))
364 bfd_set_error (bfd_error_invalid_operation);
368 /* Read the zlib header. In this case, it should be "ZLIB" followed
369 by the uncompressed section size, 8 bytes in big-endian order. */
370 if (! CONST_STRNEQ ((char*) compressed_buffer, "ZLIB"))
372 bfd_set_error (bfd_error_wrong_format);
376 uncompressed_size = compressed_buffer[4]; uncompressed_size <<= 8;
377 uncompressed_size += compressed_buffer[5]; uncompressed_size <<= 8;
378 uncompressed_size += compressed_buffer[6]; uncompressed_size <<= 8;
379 uncompressed_size += compressed_buffer[7]; uncompressed_size <<= 8;
380 uncompressed_size += compressed_buffer[8]; uncompressed_size <<= 8;
381 uncompressed_size += compressed_buffer[9]; uncompressed_size <<= 8;
382 uncompressed_size += compressed_buffer[10]; uncompressed_size <<= 8;
383 uncompressed_size += compressed_buffer[11];
385 sec->compressed_size = sec->size;
386 sec->size = uncompressed_size;
387 sec->compress_status = DECOMPRESS_SECTION_SIZED;
395 bfd_init_section_compress_status
398 bfd_boolean bfd_init_section_compress_status
399 (bfd *abfd, asection *section);
402 If open for read, compress section, update section size with
403 compressed size and set compress_status to COMPRESS_SECTION_DONE.
405 Return @code{FALSE} if the section is not a valid compressed
406 section or zlib is not installed on this machine. Otherwise,
411 bfd_init_section_compress_status (bfd *abfd ATTRIBUTE_UNUSED,
412 sec_ptr sec ATTRIBUTE_UNUSED)
415 bfd_set_error (bfd_error_invalid_operation);
418 bfd_size_type uncompressed_size;
419 bfd_byte *uncompressed_buffer;
422 /* Error if not opened for read. */
423 if (abfd->direction != read_direction
426 || sec->contents != NULL
427 || sec->compress_status != COMPRESS_SECTION_NONE)
429 bfd_set_error (bfd_error_invalid_operation);
433 /* Read in the full section contents and compress it. */
434 uncompressed_size = sec->size;
435 uncompressed_buffer = (bfd_byte *) bfd_malloc (uncompressed_size);
436 if (!bfd_get_section_contents (abfd, sec, uncompressed_buffer,
437 0, uncompressed_size))
440 ret = bfd_compress_section_contents (abfd, sec,
444 free (uncompressed_buffer);