diff options
Diffstat (limited to 'libdwelf')
| -rw-r--r-- | libdwelf/ChangeLog | 7 | ||||
| -rw-r--r-- | libdwelf/Makefile.am | 4 | ||||
| -rw-r--r-- | libdwelf/dwelf_scn_gnu_compressed_size.c | 77 | ||||
| -rw-r--r-- | libdwelf/libdwelf.h | 9 |
4 files changed, 94 insertions, 3 deletions
diff --git a/libdwelf/ChangeLog b/libdwelf/ChangeLog index f182ecf4..fe8af1b4 100644 --- a/libdwelf/ChangeLog +++ b/libdwelf/ChangeLog @@ -1,3 +1,10 @@ +2015-10-28 Mark Wielaard <[email protected]> + + * Makefile.am (libdwelf_a_SOURCES): Add + dwelf_scn_gnu_compressed_size.c. + * dwelf_scn_gnu_compressed_size.c: Likewise. + * libdwelf.h (dwelf_scn_gnu_compressed_size): New declaration. + 2015-10-14 Chih-Hung Hsieh <[email protected]> * dwelf_elf_gnu_build_id.c (find_elf_build_id): Move nested function diff --git a/libdwelf/Makefile.am b/libdwelf/Makefile.am index cd4b7ddf..4de4b2ed 100644 --- a/libdwelf/Makefile.am +++ b/libdwelf/Makefile.am @@ -2,7 +2,7 @@ ## ## Process this file with automake to create Makefile.in ## -## Copyright (C) 2014 Red Hat, Inc. +## Copyright (C) 2014, 2015 Red Hat, Inc. ## This file is part of elfutils. ## ## This file is free software; you can redistribute it and/or modify @@ -40,7 +40,7 @@ pkginclude_HEADERS = libdwelf.h noinst_HEADERS = libdwelfP.h libdwelf_a_SOURCES = dwelf_elf_gnu_debuglink.c dwelf_dwarf_gnu_debugaltlink.c \ - dwelf_elf_gnu_build_id.c + dwelf_elf_gnu_build_id.c dwelf_scn_gnu_compressed_size.c libdwelf = $(libdw) diff --git a/libdwelf/dwelf_scn_gnu_compressed_size.c b/libdwelf/dwelf_scn_gnu_compressed_size.c new file mode 100644 index 00000000..d39b702a --- /dev/null +++ b/libdwelf/dwelf_scn_gnu_compressed_size.c @@ -0,0 +1,77 @@ +/* Return size of GNU compressed section. + Copyright (C) 2015 Red Hat, Inc. + This file is part of elfutils. + + This file is free software; you can redistribute it and/or modify + it under the terms of either + + * the GNU Lesser General Public License as published by the Free + Software Foundation; either version 3 of the License, or (at + your option) any later version + + or + + * the GNU General Public License as published by the Free + Software Foundation; either version 2 of the License, or (at + your option) any later version + + or both in parallel, as here. + + elfutils 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 copies of the GNU General Public License and + the GNU Lesser General Public License along with this program. If + not, see <http://www.gnu.org/licenses/>. */ + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif + +#include "libdwelfP.h" +#include "libelfP.h" + +ssize_t +dwelf_scn_gnu_compressed_size (Elf_Scn *scn) +{ + if (scn == NULL) + return -1; + + GElf_Shdr shdr; + if (gelf_getshdr (scn, &shdr) == NULL) + return -1; + + /* Allocated or no bits sections can never be compressed. */ + if ((shdr.sh_flags & SHF_ALLOC) != 0 + || shdr.sh_type == SHT_NULL + || shdr.sh_type == SHT_NOBITS) + return -1; + + Elf_Data *d = elf_rawdata (scn, NULL); + if (d == NULL) + return -1; + + if (d->d_size >= 4 + 8 + && memcmp (d->d_buf, "ZLIB", 4) == 0) + { + /* There is a 12-byte header of "ZLIB" followed by + an 8-byte big-endian size. There is only one type and + alignment isn't preserved separately. */ + uint64_t size; + memcpy (&size, d->d_buf + 4, sizeof size); + size = be64toh (size); + + /* One more sanity check, size should be bigger than original + data size plus some overhead (4 chars ZLIB + 8 bytes size + 6 + bytes zlib stream overhead + 5 bytes overhead max for one 16K + block) and should fit into a size_t. */ + if (size + 4 + 8 + 6 + 5 < d->d_size || size > SIZE_MAX) + return -1; + + return size; + } + + return -1; +} diff --git a/libdwelf/libdwelf.h b/libdwelf/libdwelf.h index e16dc0f3..7f7f679a 100644 --- a/libdwelf/libdwelf.h +++ b/libdwelf/libdwelf.h @@ -1,5 +1,5 @@ /* Interfaces for libdwelf. DWARF ELF Low-level Functions. - Copyright (C) 2014 Red Hat, Inc. + Copyright (C) 2014, 2015 Red Hat, Inc. This file is part of elfutils. This file is free software; you can redistribute it and/or modify @@ -65,6 +65,13 @@ extern ssize_t dwelf_dwarf_gnu_debugaltlink (Dwarf *dwarf, note. Returns -1 in case of malformed data or other errors. */ extern ssize_t dwelf_elf_gnu_build_id (Elf *elf, const void **build_idp); +/* Returns the size of the uncompressed data of a GNU compressed + section. The section name should start with .zdebug (but this + isn't checked by this function). If the section isn't compressed + (the section data doesn't start with ZLIB) -1 is returned. If an + error occured -1 is returned and elf_errno is set. */ +extern ssize_t dwelf_scn_gnu_compressed_size (Elf_Scn *scn); + #ifdef __cplusplus } #endif |