-/* ELF attributes support (based on ARM EABI attributes).
- Copyright 2008
- Free Software Foundation, Inc.
+/* Compressed section support (intended for debug sections).
+ Copyright (C) 2008-2017 Free Software Foundation, Inc.
This file is part of BFD, the Binary File Descriptor library.
Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
MA 02110-1301, USA. */
-#include "config.h"
#include "sysdep.h"
+#include <zlib.h>
#include "bfd.h"
#include "libbfd.h"
-#ifdef HAVE_ZLIB_H
-#include <zlib.h>
-#endif
-
-/*
-FUNCTION
- bfd_uncompress_section_contents
+#include "safe-ctype.h"
-SYNOPSIS
- bfd_boolean bfd_uncompress_section_contents
- (bfd_byte **buffer, bfd_size_type *size);
+#define MAX_COMPRESSION_HEADER_SIZE 24
-DESCRIPTION
-
- Uncompresses a section that was compressed using zlib, in place. At
- the call to this function, *@var{buffer} and *@var{size} should point
- to the section contents to be uncompressed. At the end of the
- function, *@var{buffer} and *@var{size} will point to the uncompressed
- contents. This function assumes *BUFFER was allocated using
- bfd_malloc() or equivalent. If the section is not a valid compressed
- section, or zlib is not installed on this machine, the input is
- unmodified.
-
- Returns @code{FALSE} if unable to uncompress successfully; in that case
- the input is unmodified. Otherwise, returns @code{TRUE}.
-*/
-
-bfd_boolean
-bfd_uncompress_section_contents (bfd_byte **buffer, bfd_size_type *size)
+static bfd_boolean
+decompress_contents (bfd_byte *compressed_buffer,
+ bfd_size_type compressed_size,
+ bfd_byte *uncompressed_buffer,
+ bfd_size_type uncompressed_size)
{
-#ifndef HAVE_ZLIB_H
- /* These are just to quiet gcc. */
- buffer = 0;
- size = 0;
- return FALSE;
-#else
- bfd_size_type compressed_size = *size;
- bfd_byte *compressed_buffer = *buffer;
- bfd_size_type uncompressed_size;
- bfd_byte *uncompressed_buffer;
z_stream strm;
int rc;
- bfd_size_type header_size = 12;
-
- /* Read the zlib header. In this case, it should be "ZLIB" followed
- by the uncompressed section size, 8 bytes in big-endian order. */
- if (compressed_size < header_size
- || ! CONST_STRNEQ ((char*) compressed_buffer, "ZLIB"))
- return FALSE;
- uncompressed_size = compressed_buffer[4]; uncompressed_size <<= 8;
- uncompressed_size += compressed_buffer[5]; uncompressed_size <<= 8;
- uncompressed_size += compressed_buffer[6]; uncompressed_size <<= 8;
- uncompressed_size += compressed_buffer[7]; uncompressed_size <<= 8;
- uncompressed_size += compressed_buffer[8]; uncompressed_size <<= 8;
- uncompressed_size += compressed_buffer[9]; uncompressed_size <<= 8;
- uncompressed_size += compressed_buffer[10]; uncompressed_size <<= 8;
- uncompressed_size += compressed_buffer[11];
/* It is possible the section consists of several compressed
buffers concatenated together, so we uncompress in a loop. */
- strm.zalloc = NULL;
- strm.zfree = NULL;
- strm.opaque = NULL;
- strm.avail_in = compressed_size - header_size;
- strm.next_in = (Bytef*) compressed_buffer + header_size;
+ /* PR 18313: The state field in the z_stream structure is supposed
+ to be invisible to the user (ie us), but some compilers will
+ still complain about it being used without initialisation. So
+ we first zero the entire z_stream structure and then set the fields
+ that we need. */
+ memset (& strm, 0, sizeof strm);
+ strm.avail_in = compressed_size;
+ strm.next_in = (Bytef*) compressed_buffer;
strm.avail_out = uncompressed_size;
- uncompressed_buffer = (bfd_byte *) bfd_malloc (uncompressed_size);
- if (! uncompressed_buffer)
- return FALSE;
+ BFD_ASSERT (Z_OK == 0);
rc = inflateInit (&strm);
- while (strm.avail_in > 0)
+ while (strm.avail_in > 0 && strm.avail_out > 0)
{
if (rc != Z_OK)
- goto fail;
+ break;
strm.next_out = ((Bytef*) uncompressed_buffer
+ (uncompressed_size - strm.avail_out));
rc = inflate (&strm, Z_FINISH);
if (rc != Z_STREAM_END)
- goto fail;
+ break;
rc = inflateReset (&strm);
}
- rc = inflateEnd (&strm);
- if (rc != Z_OK
- || strm.avail_out != 0)
- goto fail;
+ rc |= inflateEnd (&strm);
+ return rc == Z_OK && strm.avail_out == 0;
+}
- free (compressed_buffer);
- *buffer = uncompressed_buffer;
- *size = uncompressed_size;
- return TRUE;
+/* Compress data of the size specified in @var{uncompressed_size}
+ and pointed to by @var{uncompressed_buffer} using zlib and store
+ as the contents field. This function assumes the contents
+ field was allocated using bfd_malloc() or equivalent.
+
+ Return the uncompressed size if the full section contents is
+ compressed successfully. Otherwise return 0. */
+
+static bfd_size_type
+bfd_compress_section_contents (bfd *abfd, sec_ptr sec,
+ bfd_byte *uncompressed_buffer,
+ bfd_size_type uncompressed_size)
+{
+ uLong compressed_size;
+ bfd_byte *buffer;
+ bfd_size_type buffer_size;
+ bfd_boolean decompress;
+ int zlib_size = 0;
+ int orig_compression_header_size;
+ bfd_size_type orig_uncompressed_size;
+ int header_size = bfd_get_compression_header_size (abfd, NULL);
+ bfd_boolean compressed
+ = bfd_is_section_compressed_with_header (abfd, sec,
+ &orig_compression_header_size,
+ &orig_uncompressed_size);
+
+ /* Either ELF compression header or the 12-byte, "ZLIB" + 8-byte size,
+ overhead in .zdebug* section. */
+ if (!header_size)
+ header_size = 12;
+
+ if (compressed)
+ {
+ /* We shouldn't decompress unsupported compressed section. */
+ if (orig_compression_header_size < 0)
+ abort ();
+
+ /* Different compression schemes. Just move the compressed section
+ contents to the right position. */
+ if (orig_compression_header_size == 0)
+ {
+ /* Convert it from .zdebug* section. Get the uncompressed
+ size first. We need to substract the 12-byte overhead in
+ .zdebug* section. Set orig_compression_header_size to
+ the 12-bye overhead. */
+ orig_compression_header_size = 12;
+ zlib_size = uncompressed_size - 12;
+ }
+ else
+ {
+ /* Convert it to .zdebug* section. */
+ zlib_size = uncompressed_size - orig_compression_header_size;
+ }
+
+ /* Add the header size. */
+ compressed_size = zlib_size + header_size;
+ }
+ else
+ compressed_size = compressBound (uncompressed_size) + header_size;
+
+ /* Uncompress if it leads to smaller size. */
+ if (compressed && compressed_size > orig_uncompressed_size)
+ {
+ decompress = TRUE;
+ buffer_size = orig_uncompressed_size;
+ }
+ else
+ {
+ decompress = FALSE;
+ buffer_size = compressed_size;
+ }
+ buffer = (bfd_byte *) bfd_alloc (abfd, buffer_size);
+ if (buffer == NULL)
+ return 0;
+
+ if (compressed)
+ {
+ sec->size = orig_uncompressed_size;
+ if (decompress)
+ {
+ if (!decompress_contents (uncompressed_buffer
+ + orig_compression_header_size,
+ zlib_size, buffer, buffer_size))
+ {
+ bfd_set_error (bfd_error_bad_value);
+ bfd_release (abfd, buffer);
+ return 0;
+ }
+ free (uncompressed_buffer);
+ sec->contents = buffer;
+ sec->compress_status = COMPRESS_SECTION_DONE;
+ return orig_uncompressed_size;
+ }
+ else
+ {
+ bfd_update_compression_header (abfd, buffer, sec);
+ memmove (buffer + header_size,
+ uncompressed_buffer + orig_compression_header_size,
+ zlib_size);
+ }
+ }
+ else
+ {
+ if (compress ((Bytef*) buffer + header_size,
+ &compressed_size,
+ (const Bytef*) uncompressed_buffer,
+ uncompressed_size) != Z_OK)
+ {
+ bfd_release (abfd, buffer);
+ bfd_set_error (bfd_error_bad_value);
+ return 0;
+ }
+
+ compressed_size += header_size;
+ /* PR binutils/18087: If compression didn't make the section smaller,
+ just keep it uncompressed. */
+ if (compressed_size < uncompressed_size)
+ bfd_update_compression_header (abfd, buffer, sec);
+ else
+ {
+ /* NOTE: There is a small memory leak here since
+ uncompressed_buffer is malloced and won't be freed. */
+ bfd_release (abfd, buffer);
+ sec->contents = uncompressed_buffer;
+ sec->compress_status = COMPRESS_SECTION_NONE;
+ return uncompressed_size;
+ }
+ }
- fail:
free (uncompressed_buffer);
- return FALSE;
-#endif /* HAVE_ZLIB_H */
+ sec->contents = buffer;
+ sec->size = compressed_size;
+ sec->compress_status = COMPRESS_SECTION_DONE;
+
+ return uncompressed_size;
+}
+
+/*
+FUNCTION
+ bfd_get_full_section_contents
+
+SYNOPSIS
+ bfd_boolean bfd_get_full_section_contents
+ (bfd *abfd, asection *section, bfd_byte **ptr);
+
+DESCRIPTION
+ Read all data from @var{section} in BFD @var{abfd}, decompress
+ if needed, and store in @var{*ptr}. If @var{*ptr} is NULL,
+ return @var{*ptr} with memory malloc'd by this function.
+
+ Return @code{TRUE} if the full section contents is retrieved
+ successfully. If the section has no contents then this function
+ returns @code{TRUE} but @var{*ptr} is set to NULL.
+*/
+
+bfd_boolean
+bfd_get_full_section_contents (bfd *abfd, sec_ptr sec, bfd_byte **ptr)
+{
+ bfd_size_type sz;
+ bfd_byte *p = *ptr;
+ bfd_boolean ret;
+ bfd_size_type save_size;
+ bfd_size_type save_rawsize;
+ bfd_byte *compressed_buffer;
+ unsigned int compression_header_size;
+
+ if (abfd->direction != write_direction && sec->rawsize != 0)
+ sz = sec->rawsize;
+ else
+ sz = sec->size;
+ if (sz == 0)
+ {
+ *ptr = NULL;
+ return TRUE;
+ }
+
+ switch (sec->compress_status)
+ {
+ case COMPRESS_SECTION_NONE:
+ if (p == NULL)
+ {
+ p = (bfd_byte *) bfd_malloc (sz);
+ if (p == NULL)
+ {
+ /* PR 20801: Provide a more helpful error message. */
+ if (bfd_get_error () == bfd_error_no_memory)
+ _bfd_error_handler
+ /* xgettext:c-format */
+ (_("error: %B(%A) is too large (%#lx bytes)"),
+ abfd, sec, (long) sz);
+ return FALSE;
+ }
+ }
+
+ if (!bfd_get_section_contents (abfd, sec, p, 0, sz))
+ {
+ if (*ptr != p)
+ free (p);
+ return FALSE;
+ }
+ *ptr = p;
+ return TRUE;
+
+ case DECOMPRESS_SECTION_SIZED:
+ /* Read in the full compressed section contents. */
+ compressed_buffer = (bfd_byte *) bfd_malloc (sec->compressed_size);
+ if (compressed_buffer == NULL)
+ return FALSE;
+ save_rawsize = sec->rawsize;
+ save_size = sec->size;
+ /* Clear rawsize, set size to compressed size and set compress_status
+ to COMPRESS_SECTION_NONE. If the compressed size is bigger than
+ the uncompressed size, bfd_get_section_contents will fail. */
+ sec->rawsize = 0;
+ sec->size = sec->compressed_size;
+ sec->compress_status = COMPRESS_SECTION_NONE;
+ ret = bfd_get_section_contents (abfd, sec, compressed_buffer,
+ 0, sec->compressed_size);
+ /* Restore rawsize and size. */
+ sec->rawsize = save_rawsize;
+ sec->size = save_size;
+ sec->compress_status = DECOMPRESS_SECTION_SIZED;
+ if (!ret)
+ goto fail_compressed;
+
+ if (p == NULL)
+ p = (bfd_byte *) bfd_malloc (sz);
+ if (p == NULL)
+ goto fail_compressed;
+
+ compression_header_size = bfd_get_compression_header_size (abfd, sec);
+ if (compression_header_size == 0)
+ /* Set header size to the zlib header size if it is a
+ SHF_COMPRESSED section. */
+ compression_header_size = 12;
+ if (!decompress_contents (compressed_buffer + compression_header_size,
+ sec->compressed_size - compression_header_size, p, sz))
+ {
+ bfd_set_error (bfd_error_bad_value);
+ if (p != *ptr)
+ free (p);
+ fail_compressed:
+ free (compressed_buffer);
+ return FALSE;
+ }
+
+ free (compressed_buffer);
+ *ptr = p;
+ return TRUE;
+
+ case COMPRESS_SECTION_DONE:
+ if (sec->contents == NULL)
+ return FALSE;
+ if (p == NULL)
+ {
+ p = (bfd_byte *) bfd_malloc (sz);
+ if (p == NULL)
+ return FALSE;
+ *ptr = p;
+ }
+ /* PR 17512; file: 5bc29788. */
+ if (p != sec->contents)
+ memcpy (p, sec->contents, sz);
+ return TRUE;
+
+ default:
+ abort ();
+ }
+}
+
+/*
+FUNCTION
+ bfd_cache_section_contents
+
+SYNOPSIS
+ void bfd_cache_section_contents
+ (asection *sec, void *contents);
+
+DESCRIPTION
+ Stash @var(contents) so any following reads of @var(sec) do
+ not need to decompress again.
+*/
+
+void
+bfd_cache_section_contents (asection *sec, void *contents)
+{
+ if (sec->compress_status == DECOMPRESS_SECTION_SIZED)
+ sec->compress_status = COMPRESS_SECTION_DONE;
+ sec->contents = contents;
+ sec->flags |= SEC_IN_MEMORY;
+}
+
+/*
+FUNCTION
+ bfd_is_section_compressed_with_header
+
+SYNOPSIS
+ bfd_boolean bfd_is_section_compressed_with_header
+ (bfd *abfd, asection *section,
+ int *compression_header_size_p,
+ bfd_size_type *uncompressed_size_p);
+
+DESCRIPTION
+ Return @code{TRUE} if @var{section} is compressed. Compression
+ header size is returned in @var{compression_header_size_p} and
+ uncompressed size is returned in @var{uncompressed_size_p}. If
+ compression is unsupported, compression header size is returned
+ with -1 and uncompressed size is returned with 0.
+*/
+
+bfd_boolean
+bfd_is_section_compressed_with_header (bfd *abfd, sec_ptr sec,
+ int *compression_header_size_p,
+ bfd_size_type *uncompressed_size_p)
+{
+ bfd_byte header[MAX_COMPRESSION_HEADER_SIZE];
+ int compression_header_size;
+ int header_size;
+ unsigned int saved = sec->compress_status;
+ bfd_boolean compressed;
+
+ compression_header_size = bfd_get_compression_header_size (abfd, sec);
+ if (compression_header_size > MAX_COMPRESSION_HEADER_SIZE)
+ abort ();
+ header_size = compression_header_size ? compression_header_size : 12;
+
+ /* Don't decompress the section. */
+ sec->compress_status = COMPRESS_SECTION_NONE;
+
+ /* Read the header. */
+ if (bfd_get_section_contents (abfd, sec, header, 0, header_size))
+ {
+ if (compression_header_size == 0)
+ /* In this case, it should be "ZLIB" followed by the uncompressed
+ section size, 8 bytes in big-endian order. */
+ compressed = CONST_STRNEQ ((char*) header , "ZLIB");
+ else
+ compressed = TRUE;
+ }
+ else
+ compressed = FALSE;
+
+ *uncompressed_size_p = sec->size;
+ if (compressed)
+ {
+ if (compression_header_size != 0)
+ {
+ if (!bfd_check_compression_header (abfd, header, sec,
+ uncompressed_size_p))
+ compression_header_size = -1;
+ }
+ /* Check for the pathalogical case of a debug string section that
+ contains the string ZLIB.... as the first entry. We assume that
+ no uncompressed .debug_str section would ever be big enough to
+ have the first byte of its (big-endian) size be non-zero. */
+ else if (strcmp (sec->name, ".debug_str") == 0
+ && ISPRINT (header[4]))
+ compressed = FALSE;
+ else
+ *uncompressed_size_p = bfd_getb64 (header + 4);
+ }
+
+ /* Restore compress_status. */
+ sec->compress_status = saved;
+ *compression_header_size_p = compression_header_size;
+ return compressed;
+}
+
+/*
+FUNCTION
+ bfd_is_section_compressed
+
+SYNOPSIS
+ bfd_boolean bfd_is_section_compressed
+ (bfd *abfd, asection *section);
+
+DESCRIPTION
+ Return @code{TRUE} if @var{section} is compressed.
+*/
+
+bfd_boolean
+bfd_is_section_compressed (bfd *abfd, sec_ptr sec)
+{
+ int compression_header_size;
+ bfd_size_type uncompressed_size;
+ return (bfd_is_section_compressed_with_header (abfd, sec,
+ &compression_header_size,
+ &uncompressed_size)
+ && compression_header_size >= 0
+ && uncompressed_size > 0);
+}
+
+/*
+FUNCTION
+ bfd_init_section_decompress_status
+
+SYNOPSIS
+ bfd_boolean bfd_init_section_decompress_status
+ (bfd *abfd, asection *section);
+
+DESCRIPTION
+ Record compressed section size, update section size with
+ decompressed size and set compress_status to
+ DECOMPRESS_SECTION_SIZED.
+
+ Return @code{FALSE} if the section is not a valid compressed
+ section. Otherwise, return @code{TRUE}.
+*/
+
+bfd_boolean
+bfd_init_section_decompress_status (bfd *abfd, sec_ptr sec)
+{
+ bfd_byte header[MAX_COMPRESSION_HEADER_SIZE];
+ int compression_header_size;
+ int header_size;
+ bfd_size_type uncompressed_size;
+
+ compression_header_size = bfd_get_compression_header_size (abfd, sec);
+ if (compression_header_size > MAX_COMPRESSION_HEADER_SIZE)
+ abort ();
+ header_size = compression_header_size ? compression_header_size : 12;
+
+ /* Read the header. */
+ if (sec->rawsize != 0
+ || sec->contents != NULL
+ || sec->compress_status != COMPRESS_SECTION_NONE
+ || !bfd_get_section_contents (abfd, sec, header, 0, header_size))
+ {
+ bfd_set_error (bfd_error_invalid_operation);
+ return FALSE;
+ }
+
+ if (compression_header_size == 0)
+ {
+ /* In this case, it should be "ZLIB" followed by the uncompressed
+ section size, 8 bytes in big-endian order. */
+ if (! CONST_STRNEQ ((char*) header, "ZLIB"))
+ {
+ bfd_set_error (bfd_error_wrong_format);
+ return FALSE;
+ }
+ uncompressed_size = bfd_getb64 (header + 4);
+ }
+ else if (!bfd_check_compression_header (abfd, header, sec,
+ &uncompressed_size))
+ {
+ bfd_set_error (bfd_error_wrong_format);
+ return FALSE;
+ }
+
+ sec->compressed_size = sec->size;
+ sec->size = uncompressed_size;
+ sec->compress_status = DECOMPRESS_SECTION_SIZED;
+
+ return TRUE;
+}
+
+/*
+FUNCTION
+ bfd_init_section_compress_status
+
+SYNOPSIS
+ bfd_boolean bfd_init_section_compress_status
+ (bfd *abfd, asection *section);
+
+DESCRIPTION
+ If open for read, compress section, update section size with
+ compressed size and set compress_status to COMPRESS_SECTION_DONE.
+
+ Return @code{FALSE} if the section is not a valid compressed
+ section. Otherwise, return @code{TRUE}.
+*/
+
+bfd_boolean
+bfd_init_section_compress_status (bfd *abfd, sec_ptr sec)
+{
+ bfd_size_type uncompressed_size;
+ bfd_byte *uncompressed_buffer;
+ bfd_boolean ret;
+
+ /* Error if not opened for read. */
+ if (abfd->direction != read_direction
+ || sec->size == 0
+ || sec->rawsize != 0
+ || sec->contents != NULL
+ || sec->compress_status != COMPRESS_SECTION_NONE)
+ {
+ bfd_set_error (bfd_error_invalid_operation);
+ return FALSE;
+ }
+
+ /* Read in the full section contents and compress it. */
+ uncompressed_size = sec->size;
+ uncompressed_buffer = (bfd_byte *) bfd_malloc (uncompressed_size);
+ if (!bfd_get_section_contents (abfd, sec, uncompressed_buffer,
+ 0, uncompressed_size))
+ ret = FALSE;
+ else
+ {
+ uncompressed_size = bfd_compress_section_contents (abfd, sec,
+ uncompressed_buffer,
+ uncompressed_size);
+ ret = uncompressed_size != 0;
+ }
+
+ return ret;
+}
+
+/*
+FUNCTION
+ bfd_compress_section
+
+SYNOPSIS
+ bfd_boolean bfd_compress_section
+ (bfd *abfd, asection *section, bfd_byte *uncompressed_buffer);
+
+DESCRIPTION
+ If open for write, compress section, update section size with
+ compressed size and set compress_status to COMPRESS_SECTION_DONE.
+
+ Return @code{FALSE} if compression fail. Otherwise, return
+ @code{TRUE}.
+*/
+
+bfd_boolean
+bfd_compress_section (bfd *abfd, sec_ptr sec, bfd_byte *uncompressed_buffer)
+{
+ bfd_size_type uncompressed_size = sec->size;
+
+ /* Error if not opened for write. */
+ if (abfd->direction != write_direction
+ || uncompressed_size == 0
+ || uncompressed_buffer == NULL
+ || sec->contents != NULL
+ || sec->compressed_size != 0
+ || sec->compress_status != COMPRESS_SECTION_NONE)
+ {
+ bfd_set_error (bfd_error_invalid_operation);
+ return FALSE;
+ }
+
+ /* Compress it. */
+ return bfd_compress_section_contents (abfd, sec, uncompressed_buffer,
+ uncompressed_size) != 0;
}