diff options
Diffstat (limited to 'libelf/gelf_getsymshndx.c')
| -rw-r--r-- | libelf/gelf_getsymshndx.c | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/libelf/gelf_getsymshndx.c b/libelf/gelf_getsymshndx.c new file mode 100644 index 00000000..856f4919 --- /dev/null +++ b/libelf/gelf_getsymshndx.c @@ -0,0 +1,128 @@ +/* Get symbol information and separate section index from symbol table + at the given index. + Copyright (C) 2000, 2001, 2002 Red Hat, Inc. + Written by Ulrich Drepper <drepper@redhat.com>, 2000. + + 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, version 2. + + 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif + +#include <assert.h> +#include <gelf.h> +#include <string.h> + +#include "libelfP.h" + + +GElf_Sym * +gelf_getsymshndx (symdata, shndxdata, ndx, dst, dstshndx) + Elf_Data *symdata; + Elf_Data *shndxdata; + int ndx; + GElf_Sym *dst; + Elf32_Word *dstshndx; +{ + Elf_Data_Scn *symdata_scn = (Elf_Data_Scn *) symdata; + Elf_Data_Scn *shndxdata_scn = (Elf_Data_Scn *) shndxdata; + GElf_Sym *result = NULL; + Elf32_Word shndx = 0; + + if (symdata == NULL) + return NULL; + + if (unlikely (symdata->d_type != ELF_T_SYM) + || (likely (shndxdata_scn != NULL) + && unlikely (shndxdata->d_type != ELF_T_WORD))) + { + __libelf_seterrno (ELF_E_INVALID_HANDLE); + return NULL; + } + + rwlock_rdlock (symdata_scn->s->elf->lock); + + /* The user is not required to pass a data descriptor for an extended + section index table. */ + if (likely (shndxdata_scn != NULL)) + { + if (unlikely ((ndx + 1) * sizeof (Elf32_Word) > shndxdata_scn->d.d_size)) + { + __libelf_seterrno (ELF_E_INVALID_INDEX); + goto out; + } + + shndx = ((Elf32_Word *) shndxdata_scn->d.d_buf)[ndx]; + } + + /* This is the one place where we have to take advantage of the fact + that an `Elf_Data' pointer is also a pointer to `Elf_Data_Scn'. + The interface is broken so that it requires this hack. */ + if (symdata_scn->s->elf->class == ELFCLASS32) + { + Elf32_Sym *src; + + /* Here it gets a bit more complicated. The format of the symbol + table entries has to be adopted. The user better has provided + a buffer where we can store the information. While copying the + data we are converting the format. */ + if (unlikely ((ndx + 1) * sizeof (Elf32_Sym) > symdata->d_size)) + { + __libelf_seterrno (ELF_E_INVALID_INDEX); + goto out; + } + + src = &((Elf32_Sym *) symdata->d_buf)[ndx]; + + /* This might look like a simple copy operation but it's + not. There are zero- and sign-extensions going on. */ +#define COPY(name) \ + dst->name = src->name + COPY (st_name); + /* Please note that we can simply copy the `st_info' element since + the definitions of ELFxx_ST_BIND and ELFxx_ST_TYPE are the same + for the 64 bit variant. */ + COPY (st_info); + COPY (st_other); + COPY (st_shndx); + COPY (st_value); + COPY (st_size); + } + else + { + /* If this is a 64 bit object it's easy. */ + assert (sizeof (GElf_Sym) == sizeof (Elf64_Sym)); + + /* The data is already in the correct form. Just make sure the + index is OK. */ + if (unlikely ((ndx + 1) * sizeof (GElf_Sym) > symdata->d_size)) + { + __libelf_seterrno (ELF_E_INVALID_INDEX); + goto out; + } + + *dst = ((GElf_Sym *) symdata->d_buf)[ndx]; + } + + /* Now we can store the section index. */ + if (dstshndx != NULL) + *dstshndx = shndx; + + result = dst; + + out: + rwlock_unlock (symdata_scn->s->elf->lock); + + return result; +} |