LCOV - code coverage report
Current view: top level - elfutils/libelf - elf_getshdrstrndx.c (source / functions) Hit Total Coverage
Test: lcov.out Lines: 11 44 25.0 %
Date: 2013-03-08 Functions: 1 1 100.0 %
Legend: Lines: hit not hit | Branches: + taken - not taken # not executed Branches: 6 32 18.8 %

           Branch data     Line data    Source code
       1                 :            : /* Return section index of section header string table.
       2                 :            :    Copyright (C) 2002, 2005, 2009 Red Hat, Inc.
       3                 :            :    This file is part of elfutils.
       4                 :            :    Written by Ulrich Drepper <drepper@redhat.com>, 2002.
       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 <errno.h>
      36                 :            : #include <gelf.h>
      37                 :            : #include <stddef.h>
      38                 :            : #include <unistd.h>
      39                 :            : 
      40                 :            : #include <system.h>
      41                 :            : #include "libelfP.h"
      42                 :            : #include "common.h"
      43                 :            : 
      44                 :            : 
      45                 :            : int
      46                 :      89652 : elf_getshdrstrndx (elf, dst)
      47                 :            :      Elf *elf;
      48                 :            :      size_t *dst;
      49                 :            : {
      50                 :      89652 :   int result = 0;
      51                 :            : 
      52         [ +  - ]:      89652 :   if (elf == NULL)
      53                 :            :     return -1;
      54                 :            : 
      55         [ -  + ]:      89652 :   if (unlikely (elf->kind != ELF_K_ELF))
      56                 :            :     {
      57                 :          0 :       __libelf_seterrno (ELF_E_INVALID_HANDLE);
      58                 :          0 :       return -1;
      59                 :            :     }
      60                 :            : 
      61                 :            :   rwlock_rdlock (elf->lock);
      62                 :            : 
      63                 :            :   /* We rely here on the fact that the `elf' element is a common prefix
      64                 :            :      of `elf32' and `elf64'.  */
      65                 :            :   assert (offsetof (struct Elf, state.elf.ehdr)
      66                 :            :           == offsetof (struct Elf, state.elf32.ehdr));
      67                 :            :   assert (sizeof (elf->state.elf.ehdr)
      68                 :            :           == sizeof (elf->state.elf32.ehdr));
      69                 :            :   assert (offsetof (struct Elf, state.elf.ehdr)
      70                 :            :           == offsetof (struct Elf, state.elf64.ehdr));
      71                 :            :   assert (sizeof (elf->state.elf.ehdr)
      72                 :            :           == sizeof (elf->state.elf64.ehdr));
      73                 :            : 
      74         [ -  + ]:      89652 :   if (unlikely (elf->state.elf.ehdr == NULL))
      75                 :            :     {
      76                 :          0 :       __libelf_seterrno (ELF_E_WRONG_ORDER_EHDR);
      77                 :          0 :       result = -1;
      78                 :            :     }
      79                 :            :   else
      80                 :            :     {
      81                 :            :       Elf32_Word num;
      82                 :            : 
      83         [ +  + ]:      89652 :       num = (elf->class == ELFCLASS32
      84                 :        115 :              ? elf->state.elf32.ehdr->e_shstrndx
      85                 :      89537 :              : elf->state.elf64.ehdr->e_shstrndx);
      86                 :            : 
      87                 :            :       /* Determine whether the index is too big to fit in the ELF
      88                 :            :          header.  */
      89         [ -  + ]:      89652 :       if (unlikely (num == SHN_XINDEX))
      90                 :            :         {
      91                 :            :           /* Yes.  Search the zeroth section header.  */
      92         [ #  # ]:          0 :           if (elf->class == ELFCLASS32)
      93                 :            :             {
      94                 :            :               size_t offset;
      95                 :            : 
      96         [ #  # ]:          0 :               if (elf->state.elf32.scns.data[0].shdr.e32 != NULL)
      97                 :            :                 {
      98                 :          0 :                   num = elf->state.elf32.scns.data[0].shdr.e32->sh_link;
      99                 :          0 :                   goto success;
     100                 :            :                 }
     101                 :            : 
     102                 :          0 :               offset = elf->state.elf32.ehdr->e_shoff;
     103                 :            : 
     104         [ #  # ]:          0 :               if (elf->map_address != NULL
     105                 :          0 :                   && elf->state.elf32.ehdr->e_ident[EI_DATA] == MY_ELFDATA
     106         [ #  # ]:          0 :                   && (ALLOW_UNALIGNED
     107                 :            :                       || (((size_t) ((char *) elf->map_address + offset))
     108                 :            :                           & (__alignof__ (Elf32_Shdr) - 1)) == 0))
     109                 :            :                 /* We can directly access the memory.  */
     110                 :          0 :                 num = ((Elf32_Shdr *) (elf->map_address + offset))->sh_link;
     111                 :            :               else
     112                 :            :                 {
     113                 :            :                   /* We avoid reading in all the section headers.  Just read
     114                 :            :                      the first one.  */
     115                 :            :                   Elf32_Shdr shdr_mem;
     116                 :            : 
     117         [ #  # ]:          0 :                   if (unlikely (pread_retry (elf->fildes, &shdr_mem,
     118                 :            :                                              sizeof (Elf32_Shdr), offset)
     119                 :            :                                 != sizeof (Elf32_Shdr)))
     120                 :            :                     {
     121                 :            :                       /* We must be able to read this ELF section header.  */
     122                 :          0 :                       __libelf_seterrno (ELF_E_INVALID_FILE);
     123                 :          0 :                       result = -1;
     124                 :            :                       goto out;
     125                 :            :                     }
     126                 :            : 
     127         [ #  # ]:          0 :                   if (elf->state.elf32.ehdr->e_ident[EI_DATA] != MY_ELFDATA)
     128                 :          0 :                     CONVERT (shdr_mem.sh_link);
     129                 :          0 :                   num = shdr_mem.sh_link;
     130                 :            :                 }
     131                 :            :             }
     132                 :            :           else
     133                 :            :             {
     134         [ #  # ]:          0 :               if (elf->state.elf64.scns.data[0].shdr.e64 != NULL)
     135                 :            :                 {
     136                 :          0 :                   num = elf->state.elf64.scns.data[0].shdr.e64->sh_link;
     137                 :          0 :                   goto success;
     138                 :            :                 }
     139                 :            : 
     140                 :          0 :               size_t offset = elf->state.elf64.ehdr->e_shoff;
     141                 :            : 
     142         [ #  # ]:          0 :               if (elf->map_address != NULL
     143                 :          0 :                   && elf->state.elf64.ehdr->e_ident[EI_DATA] == MY_ELFDATA
     144         [ #  # ]:          0 :                   && (ALLOW_UNALIGNED
     145                 :            :                       || (((size_t) ((char *) elf->map_address + offset))
     146                 :            :                           & (__alignof__ (Elf64_Shdr) - 1)) == 0))
     147                 :            :                 /* We can directly access the memory.  */
     148                 :          0 :                 num = ((Elf64_Shdr *) (elf->map_address + offset))->sh_link;
     149                 :            :               else
     150                 :            :                 {
     151                 :            :                   /* We avoid reading in all the section headers.  Just read
     152                 :            :                      the first one.  */
     153                 :            :                   Elf64_Shdr shdr_mem;
     154                 :            : 
     155         [ #  # ]:          0 :                   if (unlikely (pread_retry (elf->fildes, &shdr_mem,
     156                 :            :                                              sizeof (Elf64_Shdr), offset)
     157                 :            :                                 != sizeof (Elf64_Shdr)))
     158                 :            :                     {
     159                 :            :                       /* We must be able to read this ELF section header.  */
     160                 :          0 :                       __libelf_seterrno (ELF_E_INVALID_FILE);
     161                 :          0 :                       result = -1;
     162                 :            :                       goto out;
     163                 :            :                     }
     164                 :            : 
     165         [ #  # ]:          0 :                   if (elf->state.elf64.ehdr->e_ident[EI_DATA] != MY_ELFDATA)
     166                 :          0 :                     CONVERT (shdr_mem.sh_link);
     167                 :          0 :                   num = shdr_mem.sh_link;
     168                 :            :                 }
     169                 :            :             }
     170                 :            :         }
     171                 :            : 
     172                 :            :       /* Store the result.  */
     173                 :            :     success:
     174                 :      89652 :       *dst = num;
     175                 :            :     }
     176                 :            : 
     177                 :            :  out:
     178                 :            :   rwlock_unlock (elf->lock);
     179                 :            : 
     180                 :      89652 :   return result;
     181                 :            : }
     182                 :            : INTDEF(elf_getshdrstrndx)
     183                 :            : /* Alias for the deprecated name.  */
     184                 :            : strong_alias (elf_getshdrstrndx, elf_getshstrndx)

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