/* Compressed section support (intended for debug sections). Copyright (C) 2008-2024 Free Software Foundation, Inc. This file is part of BFD, the Binary File Descriptor library. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */ #include "sysdep.h" #include <zlib.h> #ifdef HAVE_ZSTD #include <zstd.h> #endif #include "bfd.h" #include "elf-bfd.h" #include "libbfd.h" #include "safe-ctype.h" #include "libiberty.h" #define MAX_COMPRESSION_HEADER_SIZE 24 /* EXTERNAL .{* Types of compressed DWARF debug sections. *} .enum compressed_debug_section_type .{ . COMPRESS_DEBUG_NONE = 0, . COMPRESS_DEBUG_GNU_ZLIB = 1 << 1, . COMPRESS_DEBUG_GABI_ZLIB = 1 << 2, . COMPRESS_DEBUG_ZSTD = 1 << 3, . COMPRESS_UNKNOWN = 1 << 4 .}; . .{* Tuple for compressed_debug_section_type and their name. *} .struct compressed_type_tuple .{ . enum compressed_debug_section_type type; . const char *name; .}; . .{* Compression header ch_type values. *} .enum compression_type .{ . ch_none = 0, . ch_compress_zlib = 1 , {* Compressed with zlib. *} . ch_compress_zstd = 2 {* Compressed with zstd (www.zstandard.org). *} .}; . .static inline char * .bfd_debug_name_to_zdebug (bfd *abfd, const char *name) .{ . size_t len = strlen (name); . char *new_name = (char *) bfd_alloc (abfd, len + 2); . if (new_name == NULL) . return NULL; . new_name[0] = '.'; . new_name[1] = 'z'; . memcpy (new_name + 2, name + 1, len); . return new_name; .} . .static inline char * .bfd_zdebug_name_to_debug (bfd *abfd, const char *name) .{ . size_t len = strlen (name); . char *new_name = (char *) bfd_alloc (abfd, len); . if (new_name == NULL) . return NULL; . new_name[0] = '.'; . memcpy (new_name + 1, name + 2, len - 1); . return new_name; .} . */ /* Display texts for type of compressed DWARF debug sections. */ static const struct compressed_type_tuple compressed_debug_section_names[] = { { COMPRESS_DEBUG_NONE, "none" }, { COMPRESS_DEBUG_GABI_ZLIB, "zlib" }, { COMPRESS_DEBUG_GNU_ZLIB, "zlib-gnu" }, { COMPRESS_DEBUG_GABI_ZLIB, "zlib-gabi" }, { COMPRESS_DEBUG_ZSTD, "zstd" }, }; /* FUNCTION bfd_get_compression_algorithm SYNOPSIS enum compressed_debug_section_type bfd_get_compression_algorithm (const char *name); DESCRIPTION Return compressed_debug_section_type from a string representation. */ enum compressed_debug_section_type bfd_get_compression_algorithm (const char *name) { for (unsigned i = 0; i < ARRAY_SIZE (compressed_debug_section_names); ++i) if (strcasecmp (compressed_debug_section_names[i].name, name) == 0) return compressed_debug_section_names[i].type; return COMPRESS_UNKNOWN; } /* FUNCTION bfd_get_compression_algorithm_name SYNOPSIS const char *bfd_get_compression_algorithm_name (enum compressed_debug_section_type type); DESCRIPTION Return compression algorithm name based on the type. */ const char * bfd_get_compression_algorithm_name (enum compressed_debug_section_type type) { for (unsigned i = 0; i < ARRAY_SIZE (compressed_debug_section_names); ++i) if (type == compressed_debug_section_names[i].type) return compressed_debug_section_names[i].name; return NULL; } /* FUNCTION bfd_update_compression_header SYNOPSIS void bfd_update_compression_header (bfd *abfd, bfd_byte *contents, asection *sec); DESCRIPTION Set the compression header at CONTENTS of SEC in ABFD and update elf_section_flags for compression. */ void bfd_update_compression_header (bfd *abfd, bfd_byte *contents, asection *sec) { if ((abfd->flags & BFD_COMPRESS) == 0) abort (); switch (bfd_get_flavour (abfd)) { case bfd_target_elf_flavour: if ((abfd->flags & BFD_COMPRESS_GABI) != 0) { const struct elf_backend_data *bed = get_elf_backend_data (abfd); struct bfd_elf_section_data * esd = elf_section_data (sec); enum compression_type ch_type = (abfd->flags & BFD_COMPRESS_ZSTD ? ch_compress_zstd : ch_compress_zlib); /* Set the SHF_COMPRESSED bit. */ elf_section_flags (sec) |= SHF_COMPRESSED; if (bed->s->elfclass == ELFCLASS32) { Elf32_External_Chdr *echdr = (Elf32_External_Chdr *) contents; bfd_put_32 (abfd, ch_type, &echdr->ch_type); bfd_put_32 (abfd, sec->size, &echdr->ch_size); bfd_put_32 (abfd, 1u << sec->alignment_power, &echdr->ch_addralign); /* bfd_log2 (alignof (Elf32_Chdr)) */ bfd_set_section_alignment (sec, 2); esd->this_hdr.sh_addralign = 4; } else { Elf64_External_Chdr *echdr = (Elf64_External_Chdr *) contents; bfd_put_32 (abfd, ch_type, &echdr->ch_type); bfd_put_32 (abfd, 0, &echdr->ch_reserved); bfd_put_64 (abfd, sec->size, &echdr->ch_size); bfd_put_64 (abfd, UINT64_C (1) << sec->alignment_power, &echdr->ch_addralign); /* bfd_log2 (alignof (Elf64_Chdr)) */ bfd_set_section_alignment (sec, 3); esd->this_hdr.sh_addralign = 8; } break; } /* Clear the SHF_COMPRESSED bit. */ elf_section_flags (sec) &= ~SHF_COMPRESSED; /* Fall through. */ default: /* Write the zlib header. It should be "ZLIB" followed by the uncompressed section size, 8 bytes in big-endian order. */ memcpy (contents, "ZLIB", 4); bfd_putb64 (sec->size, contents + 4); /* No way to keep the original alignment, just use 1 always. */ bfd_set_section_alignment (sec, 0); break; } } /* Check the compression header at CONTENTS of SEC in ABFD and store the ch_type in CH_TYPE, uncompressed size in UNCOMPRESSED_SIZE, and the uncompressed data alignment in UNCOMPRESSED_ALIGNMENT_POWER if the compression header is valid. */ static bool bfd_check_compression_header (bfd *abfd, bfd_byte *contents, asection *sec, enum compression_type *ch_type, bfd_size_type *uncompressed_size, unsigned int *uncompressed_alignment_power) { if (bfd_get_flavour (abfd) == bfd_target_elf_flavour && (elf_section_flags (sec) & SHF_COMPRESSED) != 0) { Elf_Internal_Chdr chdr; const struct elf_backend_data *bed = get_elf_backend_data (abfd); if (bed->s->elfclass == ELFCLASS32) { Elf32_External_Chdr *echdr = (Elf32_External_Chdr *) contents; chdr.ch_type = bfd_get_32 (abfd, &echdr->ch_type); chdr.ch_size = bfd_get_32 (abfd, &echdr->ch_size); chdr.ch_addralign = bfd_get_32 (abfd, &echdr->ch_addralign); } else { Elf64_External_Chdr *echdr = (Elf64_External_Chdr *) contents; chdr.ch_type = bfd_get_32 (abfd, &echdr->ch_type); chdr.ch_size = bfd_get_64 (abfd, &echdr->ch_size); chdr.ch_addralign = bfd_get_64 (abfd, &echdr->ch_addralign); } *ch_type = chdr.ch_type; if ((chdr.ch_type == ch_compress_zlib || chdr.ch_type == ch_compress_zstd) && chdr.ch_addralign == (chdr.ch_addralign & -chdr.ch_addralign)) { *uncompressed_size = chdr.ch_size; *uncompressed_alignment_power = bfd_log2 (chdr.ch_addralign); return true; } } return false; } /* FUNCTION bfd_get_compression_header_size SYNOPSIS int bfd_get_compression_header_size (bfd *abfd, asection *sec); DESCRIPTION Return the size of the compression header of SEC in ABFD. */ int bfd_get_compression_header_size (bfd *abfd, asection *sec) { if (bfd_get_flavour (abfd) == bfd_target_elf_flavour) { if (sec == NULL) { if (!(abfd->flags & BFD_COMPRESS_GABI)) return 0; } else if (!(elf_section_flags (sec) & SHF_COMPRESSED)) return 0; if (get_elf_backend_data (abfd)->s->elfclass == ELFCLASS32) return sizeof (Elf32_External_Chdr); else return sizeof (Elf64_External_Chdr); } return 0; } /* FUNCTION bfd_convert_section_setup SYNOPSIS bool bfd_convert_section_setup (bfd *ibfd, asection *isec, bfd *obfd, const char **new_name, bfd_size_type *new_size); DESCRIPTION Do early setup for objcopy, when copying @var{isec} in input BFD @var{ibfd} to output BFD @var{obfd}. Returns the name and size of the output section. */ bool bfd_convert_section_setup (bfd *ibfd, asection *isec, bfd *obfd, const char **new_name, bfd_size_type *new_size) { bfd_size_type hdr_size; if ((isec->flags & SEC_DEBUGGING) != 0 && (isec->flags & SEC_HAS_CONTENTS) != 0) { const char *name = *new_name; if ((obfd->flags & (BFD_DECOMPRESS | BFD_COMPRESS_GABI)) != 0) { /* When we decompress or compress with SHF_COMPRESSED, convert section name from .zdebug_* to .debug_*. */ if (startswith (name, ".zdebug_")) { name = bfd_zdebug_name_to_debug (obfd, name); if (name == NULL) return false; } } /* PR binutils/18087: Compression does not always make a section smaller. So only rename the section when compression has actually taken place. If input section name is .zdebug_*, we should never compress it again. */ else if (isec->compress_status == COMPRESS_SECTION_DONE && startswith (name, ".debug_")) { name = bfd_debug_name_to_zdebug (obfd, name); if (name == NULL) return false; } *new_name = name; } *new_size = bfd_section_size (isec); /* Do nothing if either input or output aren't ELF. */ if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour || bfd_get_flavour (obfd) != bfd_target_elf_flavour) return true; /* Do nothing if ELF classes of input and output are the same. */ if (get_elf_backend_data (ibfd)->s->elfclass == get_elf_backend_data (obfd)->s->elfclass) return true; /* Convert GNU property size. */ if (startswith (isec->name, NOTE_GNU_PROPERTY_SECTION_NAME)) { *new_size = _bfd_elf_convert_gnu_property_size (ibfd, obfd); return true; } /* Do nothing if input file will be decompressed. */ if ((ibfd->flags & BFD_DECOMPRESS)) return true; /* Do nothing if the input section isn't a SHF_COMPRESSED section. */ hdr_size = bfd_get_compression_header_size (ibfd, isec); if (hdr_size == 0) return true; /* Adjust the size of the output SHF_COMPRESSED section. */ if (hdr_size == sizeof (Elf32_External_Chdr)) *new_size += sizeof (Elf64_External_Chdr) - sizeof (Elf32_External_Chdr); else *new_size -= sizeof (Elf64_External_Chdr) - sizeof (Elf32_External_Chdr); return true; } /* FUNCTION bfd_convert_section_contents SYNOPSIS bool bfd_convert_section_contents (bfd *ibfd, asection *isec, bfd *obfd, bfd_byte **ptr, bfd_size_type *ptr_size); DESCRIPTION Convert the contents, stored in @var{*ptr}, of the section @var{isec} in input BFD @var{ibfd} to output BFD @var{obfd} if needed. The original buffer pointed to by @var{*ptr} may be freed and @var{*ptr} is returned with memory malloc'd by this function, and the new size written to @var{ptr_size}. */ bool bfd_convert_section_contents (bfd *ibfd, sec_ptr isec, bfd *obfd, bfd_byte **ptr, bfd_size_type *ptr_size) { bfd_byte *contents; bfd_size_type ihdr_size, ohdr_size, size; Elf_Internal_Chdr chdr; bool use_memmove; /* Do nothing if either input or output aren't ELF. */ if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour || bfd_get_flavour (obfd) != bfd_target_elf_flavour) return true; /* Do nothing if ELF classes of input and output are the same. */ if (get_elf_backend_data (ibfd)->s->elfclass == get_elf_backend_data (obfd)->s->elfclass) return true; /* Convert GNU properties. */ if (startswith (isec->name, NOTE_GNU_PROPERTY_SECTION_NAME)) return _bfd_elf_convert_gnu_properties (ibfd, isec, obfd, ptr, ptr_size); /* Do nothing if input file will be decompressed. */ if ((ibfd->flags & BFD_DECOMPRESS)) return true; /* Do nothing if the input section isn't a SHF_COMPRESSED section. */ ihdr_size = bfd_get_compression_header_size (ibfd, isec); if (ihdr_size == 0) return true; /* PR 25221. Check for corrupt input sections. */ if (ihdr_size > bfd_get_section_limit (ibfd, isec)) /* FIXME: Issue a warning about a corrupt compression header size field ? */ return false; contents = *ptr; /* Convert the contents of the input SHF_COMPRESSED section to output. Get the input compression header and the size of the output compression header. */ if (ihdr_size == sizeof (Elf32_External_Chdr)) { Elf32_External_Chdr *echdr = (Elf32_External_Chdr *) contents; chdr.ch_type = bfd_get_32 (ibfd, &echdr->ch_type); chdr.ch_size = bfd_get_32 (ibfd, &echdr->ch_size); chdr.ch_addralign = bfd_get_32 (ibfd, &echdr->ch_addralign); ohdr_size = sizeof (Elf64_External_Chdr); use_memmove = false; } else if (ihdr_size != sizeof (Elf64_External_Chdr)) { /* FIXME: Issue a warning about a corrupt compression header size field ? */ return false; } else { Elf64_External_Chdr *echdr = (Elf64_External_Chdr *) contents; chdr.ch_type = bfd_get_32 (ibfd, &echdr->ch_type); chdr.ch_size = bfd_get_64 (ibfd, &echdr->ch_size); chdr.ch_addralign = bfd_get_64 (ibfd, &echdr->ch_addralign); ohdr_size = sizeof (Elf32_External_Chdr); use_memmove = true; } size = bfd_section_size (isec) - ihdr_size + ohdr_size; if (!use_memmove) { contents = (bfd_byte *) bfd_malloc (size); if (contents == NULL) return false; } /* Write out the output compression header. */ if (ohdr_size == sizeof (Elf32_External_Chdr)) { Elf32_External_Chdr *echdr = (Elf32_External_Chdr *) contents; bfd_put_32 (obfd, chdr.ch_type, &echdr->ch_type); bfd_put_32 (obfd, chdr.ch_size, &echdr->ch_size); bfd_put_32 (obfd, chdr.ch_addralign, &echdr->ch_addralign); } else { Elf64_External_Chdr *echdr = (Elf64_External_Chdr *) contents; bfd_put_32 (obfd, chdr.ch_type, &echdr->ch_type); bfd_put_32 (obfd, 0, &echdr->ch_reserved); bfd_put_64 (obfd, chdr.ch_size, &echdr->ch_size); bfd_put_64 (obfd, chdr.ch_addralign, &echdr->ch_addralign); } /* Copy the compressed contents. */ if (use_memmove) memmove (contents + ohdr_size, *ptr + ihdr_size, size - ohdr_size); else { memcpy (contents + ohdr_size, *ptr + ihdr_size, size - ohdr_size); free (*ptr); *ptr = contents; } *ptr_size = size; return true; } static bool decompress_contents (bool is_zstd, bfd_byte *compressed_buffer, bfd_size_type compressed_size, bfd_byte *uncompressed_buffer, bfd_size_type uncompressed_size) { if (is_zstd) { #ifdef HAVE_ZSTD size_t ret = ZSTD_decompress (uncompressed_buffer, uncompressed_size, compressed_buffer, compressed_size); return !ZSTD_isError (ret); #endif } z_stream strm; int rc; /* It is possible the section consists of several compressed buffers concatenated together, so we uncompress in a loop. */ /* 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; /* FIXME: strm.avail_in and strm.avail_out are typically unsigned int. Supporting sizes that don't fit in an unsigned int is possible but will require some rewriting of this function. */ if (strm.avail_in != compressed_size || strm.avail_out != uncompressed_size) return false; BFD_ASSERT (Z_OK == 0); rc = inflateInit (&strm); while (strm.avail_in > 0 && strm.avail_out > 0) { if (rc != Z_OK) break; strm.next_out = ((Bytef*) uncompressed_buffer + (uncompressed_size - strm.avail_out)); rc = inflate (&strm, Z_FINISH); if (rc != Z_STREAM_END) break; rc = inflateReset (&strm); } return inflateEnd (&strm) == Z_OK && rc == Z_OK && strm.avail_out == 0; } /* Compress section contents using zlib/zstd 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 (bfd_size_type) -1. */ static bfd_size_type bfd_compress_section_contents (bfd *abfd, sec_ptr sec) { bfd_byte *input_buffer; uLong compressed_size; bfd_byte *buffer; bfd_size_type buffer_size; int zlib_size = 0; int orig_header_size; bfd_size_type uncompressed_size; unsigned int uncompressed_alignment_pow; enum compression_type ch_type = ch_none; int new_header_size = bfd_get_compression_header_size (abfd, NULL); bool compressed = bfd_is_section_compressed_info (abfd, sec, &orig_header_size, &uncompressed_size, &uncompressed_alignment_pow, &ch_type); bool update = false; /* We shouldn't be trying to decompress unsupported compressed sections. */ if (compressed && orig_header_size < 0) abort (); /* PR 31455: Check for a corrupt uncompressed size. */ if (uncompressed_size == (bfd_size_type) -1) return uncompressed_size; /* Either ELF compression header or the 12-byte, "ZLIB" + 8-byte size, overhead in .zdebug* section. */ if (!new_header_size) new_header_size = 12; if (ch_type == ch_none) orig_header_size = 12; input_buffer = sec->contents; if (compressed) { zlib_size = sec->size - orig_header_size; compressed_size = zlib_size + new_header_size; /* If we are converting between zlib-gnu and zlib-gabi then the compressed contents just need to be moved. */ update = (ch_type < ch_compress_zstd && (abfd->flags & BFD_COMPRESS_ZSTD) == 0); /* Uncompress when not just moving contents or when compressed is not smaller than uncompressed. */ if (!update || compressed_size >= uncompressed_size) { buffer_size = uncompressed_size; buffer = bfd_malloc (buffer_size); if (buffer == NULL) return (bfd_size_type) -1; if (!decompress_contents (ch_type == ch_compress_zstd, input_buffer + orig_header_size, zlib_size, buffer, buffer_size)) { bfd_set_error (bfd_error_bad_value); free (buffer); return (bfd_size_type) -1; } free (input_buffer); bfd_set_section_alignment (sec, uncompressed_alignment_pow); sec->contents = buffer; sec->flags |= SEC_IN_MEMORY; sec->compress_status = COMPRESS_SECTION_NONE; sec->size = uncompressed_size; input_buffer = buffer; } } if (!update) compressed_size = compressBound (uncompressed_size) + new_header_size; buffer_size = compressed_size; buffer = bfd_alloc (abfd, buffer_size); if (buffer == NULL) return (bfd_size_type) -1; if (update) { if (compressed_size < uncompressed_size) memcpy (buffer + new_header_size, input_buffer + orig_header_size, zlib_size); } else { if (abfd->flags & BFD_COMPRESS_ZSTD) { #if HAVE_ZSTD compressed_size = ZSTD_compress (buffer + new_header_size, compressed_size, input_buffer, uncompressed_size, ZSTD_CLEVEL_DEFAULT); if (ZSTD_isError (compressed_size)) { bfd_release (abfd, buffer); bfd_set_error (bfd_error_bad_value); return (bfd_size_type) -1; } #endif } else if (compress ((Bytef *) buffer + new_header_size, &compressed_size, (const Bytef *) input_buffer, uncompressed_size) != Z_OK) { bfd_release (abfd, buffer); bfd_set_error (bfd_error_bad_value); return (bfd_size_type) -1; } compressed_size += new_header_size; } /* If compression didn't make the section smaller, keep it uncompressed. */ if (compressed_size >= uncompressed_size) { memcpy (buffer, input_buffer, uncompressed_size); if (bfd_get_flavour (abfd) == bfd_target_elf_flavour) elf_section_flags (sec) &= ~SHF_COMPRESSED; sec->compress_status = COMPRESS_SECTION_NONE; } else { sec->size = uncompressed_size; bfd_update_compression_header (abfd, buffer, sec); sec->size = compressed_size; sec->compress_status = COMPRESS_SECTION_DONE; } sec->contents = buffer; sec->flags |= SEC_IN_MEMORY; free (input_buffer); return uncompressed_size; } /* FUNCTION bfd_get_full_section_contents SYNOPSIS bool 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. */ bool bfd_get_full_section_contents (bfd *abfd, sec_ptr sec, bfd_byte **ptr) { bfd_size_type readsz = bfd_get_section_limit_octets (abfd, sec); bfd_size_type allocsz = bfd_get_section_alloc_size (abfd, sec); bfd_byte *p = *ptr; bool ret; bfd_size_type save_size; bfd_size_type save_rawsize; bfd_byte *compressed_buffer; unsigned int compression_header_size; const unsigned int compress_status = sec->compress_status; if (allocsz == 0) { *ptr = NULL; return true; } if (p == NULL && compress_status != COMPRESS_SECTION_DONE && bfd_section_size_insane (abfd, sec)) { /* PR 24708: Avoid attempts to allocate a ridiculous amount of memory. */ _bfd_error_handler /* xgettext:c-format */ (_("error: %pB(%pA) is too large (%#" PRIx64 " bytes)"), abfd, sec, (uint64_t) readsz); return false; } switch (compress_status) { case COMPRESS_SECTION_NONE: if (p == NULL && !sec->mmapped_p) { p = (bfd_byte *) bfd_malloc (allocsz); 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: %pB(%pA) is too large (%#" PRIx64 " bytes)"), abfd, sec, (uint64_t) allocsz); return false; } } if (!bfd_get_section_contents (abfd, sec, p, 0, readsz)) { if (*ptr != p) free (p); return false; } *ptr = p; return true; case DECOMPRESS_SECTION_ZLIB: case DECOMPRESS_SECTION_ZSTD: /* 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 = compress_status; if (!ret) goto fail_compressed; if (p == NULL) p = (bfd_byte *) bfd_malloc (allocsz); 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; bool is_zstd = compress_status == DECOMPRESS_SECTION_ZSTD; if (!decompress_contents ( is_zstd, compressed_buffer + compression_header_size, sec->compressed_size - compression_header_size, p, readsz)) { 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 (allocsz); if (p == NULL) return false; *ptr = p; } /* PR 17512; file: 5bc29788. */ if (p != sec->contents) memcpy (p, sec->contents, readsz); return true; default: abort (); } } /* FUNCTION bfd_is_section_compressed_info SYNOPSIS bool bfd_is_section_compressed_info (bfd *abfd, asection *section, int *compression_header_size_p, bfd_size_type *uncompressed_size_p, unsigned int *uncompressed_alignment_power_p, enum compression_type *ch_type); DESCRIPTION Return @code{TRUE} if @var{section} is compressed. Compression header size is returned in @var{compression_header_size_p}, uncompressed size is returned in @var{uncompressed_size_p} and the uncompressed data alignement power is returned in @var{uncompressed_align_pow_p}. If compression is unsupported, compression header size is returned with -1 and uncompressed size is returned with 0. */ bool bfd_is_section_compressed_info (bfd *abfd, sec_ptr sec, int *compression_header_size_p, bfd_size_type *uncompressed_size_p, unsigned int *uncompressed_align_pow_p, enum compression_type *ch_type) { bfd_byte header[MAX_COMPRESSION_HEADER_SIZE]; int compression_header_size; int header_size; unsigned int saved = sec->compress_status; bool compressed; *uncompressed_align_pow_p = 0; 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 = startswith ((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, ch_type, uncompressed_size_p, uncompressed_align_pow_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 bool bfd_is_section_compressed (bfd *abfd, asection *section); DESCRIPTION Return @code{TRUE} if @var{section} is compressed. */ bool bfd_is_section_compressed (bfd *abfd, sec_ptr sec) { int compression_header_size; bfd_size_type uncompressed_size; unsigned int uncompressed_align_power; enum compression_type ch_type; return (bfd_is_section_compressed_info (abfd, sec, &compression_header_size, &uncompressed_size, &uncompressed_align_power, &ch_type) && compression_header_size >= 0 && uncompressed_size > 0); } /* FUNCTION bfd_init_section_decompress_status SYNOPSIS bool 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_{ZLIB,ZSTD}. Return @code{FALSE} if the section is not a valid compressed section. Otherwise, return @code{TRUE}. */ bool 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; unsigned int uncompressed_alignment_power = 0; enum compression_type ch_type; z_stream strm; 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 (! startswith ((char*) header, "ZLIB")) { bfd_set_error (bfd_error_wrong_format); return false; } uncompressed_size = bfd_getb64 (header + 4); ch_type = ch_none; } else if (!bfd_check_compression_header (abfd, header, sec, &ch_type, &uncompressed_size, &uncompressed_alignment_power)) { bfd_set_error (bfd_error_wrong_format); return false; } /* PR28530, reject sizes unsupported by decompress_contents. */ strm.avail_in = sec->size; strm.avail_out = uncompressed_size; if (strm.avail_in != sec->size || strm.avail_out != uncompressed_size) { bfd_set_error (bfd_error_nonrepresentable_section); return false; } sec->compressed_size = sec->size; sec->size = uncompressed_size; bfd_set_section_alignment (sec, uncompressed_alignment_power); sec->compress_status = (ch_type == ch_compress_zstd ? DECOMPRESS_SECTION_ZSTD : DECOMPRESS_SECTION_ZLIB); return true; } /* FUNCTION bfd_init_section_compress_status SYNOPSIS bool 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}. */ bool bfd_init_section_compress_status (bfd *abfd, sec_ptr sec) { bfd_size_type uncompressed_size; bfd_byte *uncompressed_buffer; /* 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_section_size_insane (abfd, sec)) { 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); /* PR 21431 */ if (uncompressed_buffer == NULL) return false; if (!bfd_get_section_contents (abfd, sec, uncompressed_buffer, 0, uncompressed_size)) { free (uncompressed_buffer); return false; } sec->contents = uncompressed_buffer; if (bfd_compress_section_contents (abfd, sec) == (bfd_size_type) -1) { free (sec->contents); sec->contents = NULL; return false; } return true; } /* FUNCTION bfd_compress_section SYNOPSIS bool 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}. UNCOMPRESSED_BUFFER is freed in both cases. */ bool 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; } sec->contents = uncompressed_buffer; if (bfd_compress_section_contents (abfd, sec) == (bfd_size_type) -1) { free (sec->contents); sec->contents = NULL; return false; } return true; }