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;
66 /* Compress data of the size specified in @var{uncompressed_size}
67 and pointed to by @var{uncompressed_buffer} using zlib and store
68 as the contents field. This function assumes the contents
69 field was allocated using bfd_malloc() or equivalent. If zlib
70 is not installed on this machine, the input is unmodified.
72 Return @code{TRUE} if the full section contents is compressed
76 bfd_compress_section_contents (bfd *abfd ATTRIBUTE_UNUSED,
77 sec_ptr sec ATTRIBUTE_UNUSED,
78 bfd_byte *uncompressed_buffer ATTRIBUTE_UNUSED,
79 bfd_size_type uncompressed_size ATTRIBUTE_UNUSED)
82 bfd_set_error (bfd_error_invalid_operation);
85 uLong compressed_size;
86 bfd_byte *compressed_buffer;
88 compressed_size = compressBound (uncompressed_size) + 12;
89 compressed_buffer = (bfd_byte *) bfd_malloc (compressed_size);
91 if (compressed_buffer == NULL)
94 if (compress ((Bytef*) compressed_buffer + 12,
96 (const Bytef*) uncompressed_buffer,
97 uncompressed_size) != Z_OK)
99 free (compressed_buffer);
100 bfd_set_error (bfd_error_bad_value);
104 /* Write the zlib header. In this case, it should be "ZLIB" followed
105 by the uncompressed section size, 8 bytes in big-endian order. */
106 memcpy (compressed_buffer, "ZLIB", 4);
107 compressed_buffer[11] = uncompressed_size; uncompressed_size >>= 8;
108 compressed_buffer[10] = uncompressed_size; uncompressed_size >>= 8;
109 compressed_buffer[9] = uncompressed_size; uncompressed_size >>= 8;
110 compressed_buffer[8] = uncompressed_size; uncompressed_size >>= 8;
111 compressed_buffer[7] = uncompressed_size; uncompressed_size >>= 8;
112 compressed_buffer[6] = uncompressed_size; uncompressed_size >>= 8;
113 compressed_buffer[5] = uncompressed_size; uncompressed_size >>= 8;
114 compressed_buffer[4] = uncompressed_size;
115 compressed_size += 12;
117 /* Free the uncompressed contents if we compress in place. */
118 if (uncompressed_buffer == sec->contents)
119 free (uncompressed_buffer);
121 sec->contents = compressed_buffer;
122 sec->size = compressed_size;
123 sec->compress_status = COMPRESS_SECTION_DONE;
126 #endif /* HAVE_ZLIB_H */
131 bfd_get_full_section_contents
134 bfd_boolean bfd_get_full_section_contents
135 (bfd *abfd, asection *section, bfd_byte **ptr);
138 Read all data from @var{section} in BFD @var{abfd}, decompress
139 if needed, and store in @var{*ptr}. If @var{*ptr} is NULL,
140 return @var{*ptr} with memory malloc'd by this function.
142 Return @code{TRUE} if the full section contents is retrieved
143 successfully. If the section has no contents then this function
144 returns @code{TRUE} but @var{*ptr} is set to NULL.
148 bfd_get_full_section_contents (bfd *abfd, sec_ptr sec, bfd_byte **ptr)
154 bfd_size_type save_size;
155 bfd_size_type save_rawsize;
156 bfd_byte *compressed_buffer;
159 if (abfd->direction != write_direction && sec->rawsize != 0)
169 switch (sec->compress_status)
171 case COMPRESS_SECTION_NONE:
174 p = (bfd_byte *) bfd_malloc (sz);
179 if (!bfd_get_section_contents (abfd, sec, p, 0, sz))
188 case DECOMPRESS_SECTION_SIZED:
190 bfd_set_error (bfd_error_invalid_operation);
193 /* Read in the full compressed section contents. */
194 compressed_buffer = (bfd_byte *) bfd_malloc (sec->compressed_size);
195 if (compressed_buffer == NULL)
197 save_rawsize = sec->rawsize;
198 save_size = sec->size;
199 /* Clear rawsize, set size to compressed size and set compress_status
200 to COMPRESS_SECTION_NONE. If the compressed size is bigger than
201 the uncompressed size, bfd_get_section_contents will fail. */
203 sec->size = sec->compressed_size;
204 sec->compress_status = COMPRESS_SECTION_NONE;
205 ret = bfd_get_section_contents (abfd, sec, compressed_buffer,
206 0, sec->compressed_size);
207 /* Restore rawsize and size. */
208 sec->rawsize = save_rawsize;
209 sec->size = save_size;
210 sec->compress_status = DECOMPRESS_SECTION_SIZED;
212 goto fail_compressed;
215 p = (bfd_byte *) bfd_malloc (sz);
217 goto fail_compressed;
219 if (!decompress_contents (compressed_buffer, sec->compressed_size, p, sz))
221 bfd_set_error (bfd_error_bad_value);
225 free (compressed_buffer);
229 free (compressed_buffer);
234 case COMPRESS_SECTION_DONE:
235 if (sec->contents == NULL)
239 p = (bfd_byte *) bfd_malloc (sz);
244 /* PR 17512; file: 5bc29788. */
245 if (p != sec->contents)
246 memcpy (p, sec->contents, sz);
256 bfd_cache_section_contents
259 void bfd_cache_section_contents
260 (asection *sec, void *contents);
263 Stash @var(contents) so any following reads of @var(sec) do
264 not need to decompress again.
268 bfd_cache_section_contents (asection *sec, void *contents)
270 if (sec->compress_status == DECOMPRESS_SECTION_SIZED)
271 sec->compress_status = COMPRESS_SECTION_DONE;
272 sec->contents = contents;
273 sec->flags |= SEC_IN_MEMORY;
279 bfd_is_section_compressed
282 bfd_boolean bfd_is_section_compressed
283 (bfd *abfd, asection *section);
286 Return @code{TRUE} if @var{section} is compressed.
290 bfd_is_section_compressed (bfd *abfd, sec_ptr sec)
292 bfd_byte compressed_buffer [12];
293 unsigned int saved = sec->compress_status;
294 bfd_boolean compressed;
296 /* Don't decompress the section. */
297 sec->compress_status = COMPRESS_SECTION_NONE;
299 /* Read the zlib header. In this case, it should be "ZLIB" followed
300 by the uncompressed section size, 8 bytes in big-endian order. */
301 compressed = (bfd_get_section_contents (abfd, sec, compressed_buffer, 0, 12)
302 && CONST_STRNEQ ((char*) compressed_buffer, "ZLIB"));
304 /* Check for the pathalogical case of a debug string section that
305 contains the string ZLIB.... as the first entry. We assume that
306 no uncompressed .debug_str section would ever be big enough to
307 have the first byte of its (big-endian) size be non-zero. */
309 && strcmp (sec->name, ".debug_str") == 0
310 && ISPRINT (compressed_buffer[4]))
313 /* Restore compress_status. */
314 sec->compress_status = saved;
320 bfd_init_section_decompress_status
323 bfd_boolean bfd_init_section_decompress_status
324 (bfd *abfd, asection *section);
327 Record compressed section size, update section size with
328 decompressed size and set compress_status to
329 DECOMPRESS_SECTION_SIZED.
331 Return @code{FALSE} if the section is not a valid compressed
332 section or zlib is not installed on this machine. Otherwise,
337 bfd_init_section_decompress_status (bfd *abfd ATTRIBUTE_UNUSED,
338 sec_ptr sec ATTRIBUTE_UNUSED)
341 bfd_set_error (bfd_error_invalid_operation);
344 bfd_byte compressed_buffer [12];
345 bfd_size_type uncompressed_size;
347 if (sec->rawsize != 0
348 || sec->contents != NULL
349 || sec->compress_status != COMPRESS_SECTION_NONE
350 || !bfd_get_section_contents (abfd, sec, compressed_buffer, 0, 12))
352 bfd_set_error (bfd_error_invalid_operation);
356 /* Read the zlib header. In this case, it should be "ZLIB" followed
357 by the uncompressed section size, 8 bytes in big-endian order. */
358 if (! CONST_STRNEQ ((char*) compressed_buffer, "ZLIB"))
360 bfd_set_error (bfd_error_wrong_format);
364 uncompressed_size = compressed_buffer[4]; uncompressed_size <<= 8;
365 uncompressed_size += compressed_buffer[5]; uncompressed_size <<= 8;
366 uncompressed_size += compressed_buffer[6]; uncompressed_size <<= 8;
367 uncompressed_size += compressed_buffer[7]; uncompressed_size <<= 8;
368 uncompressed_size += compressed_buffer[8]; uncompressed_size <<= 8;
369 uncompressed_size += compressed_buffer[9]; uncompressed_size <<= 8;
370 uncompressed_size += compressed_buffer[10]; uncompressed_size <<= 8;
371 uncompressed_size += compressed_buffer[11];
373 sec->compressed_size = sec->size;
374 sec->size = uncompressed_size;
375 sec->compress_status = DECOMPRESS_SECTION_SIZED;
383 bfd_init_section_compress_status
386 bfd_boolean bfd_init_section_compress_status
387 (bfd *abfd, asection *section);
390 If open for read, compress section, update section size with
391 compressed size and set compress_status to COMPRESS_SECTION_DONE.
393 Return @code{FALSE} if the section is not a valid compressed
394 section or zlib is not installed on this machine. Otherwise,
399 bfd_init_section_compress_status (bfd *abfd ATTRIBUTE_UNUSED,
400 sec_ptr sec ATTRIBUTE_UNUSED)
403 bfd_set_error (bfd_error_invalid_operation);
406 bfd_size_type uncompressed_size;
407 bfd_byte *uncompressed_buffer;
410 /* Error if not opened for read. */
411 if (abfd->direction != read_direction
414 || sec->contents != NULL
415 || sec->compress_status != COMPRESS_SECTION_NONE)
417 bfd_set_error (bfd_error_invalid_operation);
421 /* Read in the full section contents and compress it. */
422 uncompressed_size = sec->size;
423 uncompressed_buffer = (bfd_byte *) bfd_malloc (uncompressed_size);
424 if (!bfd_get_section_contents (abfd, sec, uncompressed_buffer,
425 0, uncompressed_size))
428 ret = bfd_compress_section_contents (abfd, sec,
432 /* PR binutils/18087: If compression didn't make
433 the section smaller, just keep it uncompressed. */
434 if (ret && uncompressed_size < sec->size)
436 free (sec->contents);
437 sec->contents = uncompressed_buffer;
438 sec->size = uncompressed_size;
439 sec->compress_status = COMPRESS_SECTION_NONE;
442 free (uncompressed_buffer);