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       1                 :            : /* Get symbol information from symbol table at the given index.
       2                 :            :    Copyright (C) 1999, 2000, 2001, 2002, 2005, 2009, 2014, 2015 Red Hat, Inc.
       3                 :            :    This file is part of elfutils.
       4                 :            :    Written by Ulrich Drepper <drepper@redhat.com>, 1999.
       5                 :            : 
       6                 :            :    This file is free software; you can redistribute it and/or modify
       7                 :            :    it under the terms of either
       8                 :            : 
       9                 :            :      * the GNU Lesser General Public License as published by the Free
      10                 :            :        Software Foundation; either version 3 of the License, or (at
      11                 :            :        your option) any later version
      12                 :            : 
      13                 :            :    or
      14                 :            : 
      15                 :            :      * the GNU General Public License as published by the Free
      16                 :            :        Software Foundation; either version 2 of the License, or (at
      17                 :            :        your option) any later version
      18                 :            : 
      19                 :            :    or both in parallel, as here.
      20                 :            : 
      21                 :            :    elfutils is distributed in the hope that it will be useful, but
      22                 :            :    WITHOUT ANY WARRANTY; without even the implied warranty of
      23                 :            :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      24                 :            :    General Public License for more details.
      25                 :            : 
      26                 :            :    You should have received copies of the GNU General Public License and
      27                 :            :    the GNU Lesser General Public License along with this program.  If
      28                 :            :    not, see <http://www.gnu.org/licenses/>.  */
      29                 :            : 
      30                 :            : #ifdef HAVE_CONFIG_H
      31                 :            : # include <config.h>
      32                 :            : #endif
      33                 :            : 
      34                 :            : #include <assert.h>
      35                 :            : #include <gelf.h>
      36                 :            : #include <string.h>
      37                 :            : 
      38                 :            : #include "libelfP.h"
      39                 :            : 
      40                 :            : 
      41                 :            : GElf_Sym *
      42                 :     193840 : gelf_getsym (Elf_Data *data, int ndx, GElf_Sym *dst)
      43                 :            : {
      44                 :     193840 :   Elf_Data_Scn *data_scn = (Elf_Data_Scn *) data;
      45                 :     193840 :   GElf_Sym *result = NULL;
      46                 :            : 
      47         [ -  + ]:     193840 :   if (data == NULL)
      48                 :            :     return NULL;
      49                 :            : 
      50         [ -  + ]:     193840 :   if (unlikely (data->d_type != ELF_T_SYM))
      51                 :            :     {
      52                 :          0 :       __libelf_seterrno (ELF_E_INVALID_HANDLE);
      53                 :          0 :       return NULL;
      54                 :            :     }
      55                 :            : 
      56                 :     193840 :   rwlock_rdlock (data_scn->s->elf->lock);
      57                 :            : 
      58                 :            :   /* This is the one place where we have to take advantage of the fact
      59                 :            :      that an `Elf_Data' pointer is also a pointer to `Elf_Data_Scn'.
      60                 :            :      The interface is broken so that it requires this hack.  */
      61         [ +  + ]:     193840 :   if (data_scn->s->elf->class == ELFCLASS32)
      62                 :            :     {
      63                 :      34678 :       Elf32_Sym *src;
      64                 :            : 
      65                 :            :       /* Here it gets a bit more complicated.  The format of the symbol
      66                 :            :          table entries has to be adopted.  The user better has provided
      67                 :            :          a buffer where we can store the information.  While copying the
      68                 :            :          data we are converting the format.  */
      69         [ -  + ]:      34678 :       if (INVALID_NDX (ndx, Elf32_Sym, data))
      70                 :            :         {
      71                 :          0 :           __libelf_seterrno (ELF_E_INVALID_INDEX);
      72                 :          0 :           goto out;
      73                 :            :         }
      74                 :            : 
      75                 :      34678 :       src = &((Elf32_Sym *) data->d_buf)[ndx];
      76                 :            : 
      77                 :            :       /* This might look like a simple copy operation but it's
      78                 :            :          not.  There are zero- and sign-extensions going on.  */
      79                 :            : #define COPY(name) \
      80                 :            :       dst->name = src->name
      81                 :      34678 :       COPY (st_name);
      82                 :            :       /* Please note that we can simply copy the `st_info' element since
      83                 :            :          the definitions of ELFxx_ST_BIND and ELFxx_ST_TYPE are the same
      84                 :            :          for the 64 bit variant.  */
      85                 :      34678 :       COPY (st_info);
      86                 :      34678 :       COPY (st_other);
      87                 :      34678 :       COPY (st_shndx);
      88                 :      34678 :       COPY (st_value);
      89                 :      34678 :       COPY (st_size);
      90                 :            :     }
      91                 :            :   else
      92                 :            :     {
      93                 :            :       /* If this is a 64 bit object it's easy.  */
      94                 :     159162 :       assert (sizeof (GElf_Sym) == sizeof (Elf64_Sym));
      95                 :            : 
      96                 :            :       /* The data is already in the correct form.  Just make sure the
      97                 :            :          index is OK.  */
      98         [ -  + ]:     159162 :       if (INVALID_NDX (ndx, GElf_Sym, data))
      99                 :            :         {
     100                 :          0 :           __libelf_seterrno (ELF_E_INVALID_INDEX);
     101                 :          0 :           goto out;
     102                 :            :         }
     103                 :            : 
     104                 :     159162 :       *dst = ((GElf_Sym *) data->d_buf)[ndx];
     105                 :            :     }
     106                 :            : 
     107                 :            :   result = dst;
     108                 :            : 
     109                 :     193840 :  out:
     110                 :     193840 :   rwlock_unlock (data_scn->s->elf->lock);
     111                 :            : 
     112                 :     193840 :   return result;
     113                 :            : }
     114                 :            : INTDEF(gelf_getsym)