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      1 /* Update symbol information and section index in symbol table at the
      2    given index.
      3    Copyright (C) 2000, 2001, 2002 Red Hat, Inc.
      4    This file is part of Red Hat elfutils.
      5    Written by Ulrich Drepper <drepper (at) redhat.com>, 2000.
      6 
      7    Red Hat elfutils is free software; you can redistribute it and/or modify
      8    it under the terms of the GNU General Public License as published by the
      9    Free Software Foundation; version 2 of the License.
     10 
     11    Red Hat elfutils is distributed in the hope that it will be useful, but
     12    WITHOUT ANY WARRANTY; without even the implied warranty of
     13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     14    General Public License for more details.
     15 
     16    You should have received a copy of the GNU General Public License along
     17    with Red Hat elfutils; if not, write to the Free Software Foundation,
     18    Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.
     19 
     20    In addition, as a special exception, Red Hat, Inc. gives You the
     21    additional right to link the code of Red Hat elfutils with code licensed
     22    under any Open Source Initiative certified open source license
     23    (http://www.opensource.org/licenses/index.php) which requires the
     24    distribution of source code with any binary distribution and to
     25    distribute linked combinations of the two.  Non-GPL Code permitted under
     26    this exception must only link to the code of Red Hat elfutils through
     27    those well defined interfaces identified in the file named EXCEPTION
     28    found in the source code files (the "Approved Interfaces").  The files
     29    of Non-GPL Code may instantiate templates or use macros or inline
     30    functions from the Approved Interfaces without causing the resulting
     31    work to be covered by the GNU General Public License.  Only Red Hat,
     32    Inc. may make changes or additions to the list of Approved Interfaces.
     33    Red Hat's grant of this exception is conditioned upon your not adding
     34    any new exceptions.  If you wish to add a new Approved Interface or
     35    exception, please contact Red Hat.  You must obey the GNU General Public
     36    License in all respects for all of the Red Hat elfutils code and other
     37    code used in conjunction with Red Hat elfutils except the Non-GPL Code
     38    covered by this exception.  If you modify this file, you may extend this
     39    exception to your version of the file, but you are not obligated to do
     40    so.  If you do not wish to provide this exception without modification,
     41    you must delete this exception statement from your version and license
     42    this file solely under the GPL without exception.
     43 
     44    Red Hat elfutils is an included package of the Open Invention Network.
     45    An included package of the Open Invention Network is a package for which
     46    Open Invention Network licensees cross-license their patents.  No patent
     47    license is granted, either expressly or impliedly, by designation as an
     48    included package.  Should you wish to participate in the Open Invention
     49    Network licensing program, please visit www.openinventionnetwork.com
     50    <http://www.openinventionnetwork.com>.  */
     51 
     52 #ifdef HAVE_CONFIG_H
     53 # include <config.h>
     54 #endif
     55 
     56 #include <gelf.h>
     57 #include <stdlib.h>
     58 #include <string.h>
     59 
     60 #include "libelfP.h"
     61 
     62 
     63 int
     64 gelf_update_symshndx (symdata, shndxdata, ndx, src, srcshndx)
     65      Elf_Data *symdata;
     66      Elf_Data *shndxdata;
     67      int ndx;
     68      GElf_Sym *src;
     69      Elf32_Word srcshndx;
     70 {
     71   Elf_Data_Scn *symdata_scn = (Elf_Data_Scn *) symdata;
     72   Elf_Data_Scn *shndxdata_scn = (Elf_Data_Scn *) shndxdata;
     73   Elf_Scn *scn;
     74   Elf32_Word *shndx = NULL;
     75   int result = 0;
     76 
     77   if (symdata == NULL)
     78     return 0;
     79 
     80   if (unlikely (ndx < 0))
     81     {
     82       __libelf_seterrno (ELF_E_INVALID_INDEX);
     83       return 0;
     84     }
     85 
     86   if (unlikely (symdata_scn->d.d_type != ELF_T_SYM))
     87     {
     88       /* The type of the data better should match.  */
     89       __libelf_seterrno (ELF_E_DATA_MISMATCH);
     90       return 0;
     91     }
     92 
     93   scn = symdata_scn->s;
     94   /* We simply have to believe the user that the two sections belong to
     95      the same ELF file.  */
     96   rwlock_wrlock (scn->elf->lock);
     97 
     98   /* The user is not required to pass a data descriptor for an extended
     99      section index table.  */
    100   if (shndxdata_scn != NULL)
    101     {
    102       if (unlikely ((ndx + 1) * sizeof (Elf32_Word) > shndxdata_scn->d.d_size))
    103 	{
    104 	  __libelf_seterrno (ELF_E_INVALID_INDEX);
    105 	  goto out;
    106 	}
    107 
    108       shndx = &((Elf32_Word *) shndxdata_scn->d.d_buf)[ndx];
    109     }
    110   /* But if s/he does not the extended sectio index must be zero.  */
    111   else if (unlikely (srcshndx != 0))
    112     {
    113       __libelf_seterrno (ELF_E_INVALID_INDEX);
    114       goto out;
    115     }
    116 
    117   if (scn->elf->class == ELFCLASS32)
    118     {
    119       Elf32_Sym *sym;
    120 
    121       /* There is the possibility that the values in the input are
    122 	 too large.  */
    123       if (unlikely (src->st_value > 0xffffffffull)
    124 	  || unlikely (src->st_size > 0xffffffffull))
    125 	{
    126 	  __libelf_seterrno (ELF_E_INVALID_DATA);
    127 	  goto out;
    128 	}
    129 
    130       /* Check whether we have to resize the data buffer.  */
    131       if (unlikely ((ndx + 1) * sizeof (Elf32_Sym) > symdata_scn->d.d_size))
    132 	{
    133 	  __libelf_seterrno (ELF_E_INVALID_INDEX);
    134 	  goto out;
    135 	}
    136 
    137       sym = &((Elf32_Sym *) symdata_scn->d.d_buf)[ndx];
    138 
    139 #define COPY(name) \
    140       sym->name = src->name
    141       COPY (st_name);
    142       COPY (st_value);
    143       COPY (st_size);
    144       /* Please note that we can simply copy the `st_info' element since
    145 	 the definitions of ELFxx_ST_BIND and ELFxx_ST_TYPE are the same
    146 	 for the 64 bit variant.  */
    147       COPY (st_info);
    148       COPY (st_other);
    149       COPY (st_shndx);
    150     }
    151   else
    152     {
    153       /* Check whether we have to resize the data buffer.  */
    154       if (unlikely ((ndx + 1) * sizeof (Elf64_Sym) > symdata_scn->d.d_size))
    155 	{
    156 	  __libelf_seterrno (ELF_E_INVALID_INDEX);
    157 	  goto out;
    158 	}
    159 
    160       ((Elf64_Sym *) symdata_scn->d.d_buf)[ndx] = *src;
    161     }
    162 
    163   /* Now we can store the section index.  */
    164   if (shndx != NULL)
    165     *shndx = srcshndx;
    166 
    167   result = 1;
    168 
    169   /* Mark the section as modified.  */
    170   scn->flags |= ELF_F_DIRTY;
    171 
    172  out:
    173   rwlock_unlock (scn->elf->lock);
    174 
    175   return result;
    176 }
    177