diff options
Diffstat (limited to 'src/libelf/elf_strptr.c')
| -rw-r--r-- | src/libelf/elf_strptr.c | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/src/libelf/elf_strptr.c b/src/libelf/elf_strptr.c new file mode 100644 index 00000000..7b837b09 --- /dev/null +++ b/src/libelf/elf_strptr.c @@ -0,0 +1,182 @@ +/* Return string pointer from string section. + Copyright (C) 1998, 1999, 2000, 2001, 2002, 2004, 2008, 2009 Red Hat, Inc. + This file is part of Red Hat elfutils. + Contributed by Ulrich Drepper <drepper@redhat.com>, 1998. + + Red Hat elfutils 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; version 2 of the License. + + Red Hat 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 a copy of the GNU General Public License along + with Red Hat elfutils; if not, write to the Free Software Foundation, + Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. + + In addition, as a special exception, Red Hat, Inc. gives You the + additional right to link the code of Red Hat elfutils with code licensed + under any Open Source Initiative certified open source license + (http://www.opensource.org/licenses/index.php) which requires the + distribution of source code with any binary distribution and to + distribute linked combinations of the two. Non-GPL Code permitted under + this exception must only link to the code of Red Hat elfutils through + those well defined interfaces identified in the file named EXCEPTION + found in the source code files (the "Approved Interfaces"). The files + of Non-GPL Code may instantiate templates or use macros or inline + functions from the Approved Interfaces without causing the resulting + work to be covered by the GNU General Public License. Only Red Hat, + Inc. may make changes or additions to the list of Approved Interfaces. + Red Hat's grant of this exception is conditioned upon your not adding + any new exceptions. If you wish to add a new Approved Interface or + exception, please contact Red Hat. You must obey the GNU General Public + License in all respects for all of the Red Hat elfutils code and other + code used in conjunction with Red Hat elfutils except the Non-GPL Code + covered by this exception. If you modify this file, you may extend this + exception to your version of the file, but you are not obligated to do + so. If you do not wish to provide this exception without modification, + you must delete this exception statement from your version and license + this file solely under the GPL without exception. + + Red Hat elfutils is an included package of the Open Invention Network. + An included package of the Open Invention Network is a package for which + Open Invention Network licensees cross-license their patents. No patent + license is granted, either expressly or impliedly, by designation as an + included package. Should you wish to participate in the Open Invention + Network licensing program, please visit www.openinventionnetwork.com + <http://www.openinventionnetwork.com>. */ + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif + +#include <libelf.h> +#include <stddef.h> + +#include "libelfP.h" + + +char * +elf_strptr (elf, idx, offset) + Elf *elf; + size_t idx; + size_t offset; +{ + if (elf == NULL) + return NULL; + + if (elf->kind != ELF_K_ELF) + { + __libelf_seterrno (ELF_E_INVALID_HANDLE); + return NULL; + } + + rwlock_rdlock (elf->lock); + + char *result = NULL; + Elf_Scn *strscn; + + /* Find the section in the list. */ + Elf_ScnList *runp = (elf->class == ELFCLASS32 + || (offsetof (struct Elf, state.elf32.scns) + == offsetof (struct Elf, state.elf64.scns)) + ? &elf->state.elf32.scns : &elf->state.elf64.scns); + while (1) + { + if (idx < runp->max) + { + if (idx < runp->cnt) + strscn = &runp->data[idx]; + else + { + __libelf_seterrno (ELF_E_INVALID_INDEX); + goto out; + } + break; + } + + idx -= runp->max; + + runp = runp->next; + if (runp == NULL) + { + __libelf_seterrno (ELF_E_INVALID_INDEX); + goto out; + } + } + + if (elf->class == ELFCLASS32) + { + if (unlikely (strscn->shdr.e32->sh_type != SHT_STRTAB)) + { + /* This is no string section. */ + __libelf_seterrno (ELF_E_INVALID_SECTION); + goto out; + } + + if (unlikely (offset >= strscn->shdr.e32->sh_size)) + { + /* The given offset is too big, it is beyond this section. */ + __libelf_seterrno (ELF_E_OFFSET_RANGE); + goto out; + } + } + else + { + if (unlikely (strscn->shdr.e64->sh_type != SHT_STRTAB)) + { + /* This is no string section. */ + __libelf_seterrno (ELF_E_INVALID_SECTION); + goto out; + } + + if (unlikely (offset >= strscn->shdr.e64->sh_size)) + { + /* The given offset is too big, it is beyond this section. */ + __libelf_seterrno (ELF_E_OFFSET_RANGE); + goto out; + } + } + + if (strscn->rawdata_base == NULL && ! strscn->data_read) + { + rwlock_unlock (elf->lock); + rwlock_wrlock (elf->lock); + if (strscn->rawdata_base == NULL && ! strscn->data_read + /* Read the section data. */ + && __libelf_set_rawdata_wrlock (strscn) != 0) + goto out; + } + + if (likely (strscn->rawdata_base != NULL)) + // XXX Is this correct if a file is read and then new data is added + // XXX to the string section? Likely needs to check offset against + // XXX size of rawdata_base buffer and then iterate over rest of the + // XXX list. + result = &strscn->rawdata_base[offset]; + else + { + /* This is a file which is currently created. Use the list of + data blocks. */ + struct Elf_Data_List *dl = &strscn->data_list; + while (dl != NULL) + { + if (offset >= (size_t) dl->data.d.d_off + && offset < dl->data.d.d_off + dl->data.d.d_size) + { + result = (char *) dl->data.d.d_buf + (offset - dl->data.d.d_off); + break; + } + + dl = dl->next; + } + } + + out: + rwlock_unlock (elf->lock); + + return result; +} +INTDEF(elf_strptr) |