Branch data     Line data    Source code

       1                 :            : /* Return number of program headers in the ELF file.
       2                 :            :    Copyright (C) 2010, 2014, 2015, 2016 Red Hat, Inc.
       3                 :            :    This file is part of elfutils.
       4                 :            : 
       5                 :            :    This file is free software; you can redistribute it and/or modify
       6                 :            :    it under the terms of either
       7                 :            : 
       8                 :            :      * the GNU Lesser General Public License as published by the Free
       9                 :            :        Software Foundation; either version 3 of the License, or (at
      10                 :            :        your option) any later version
      11                 :            : 
      12                 :            :    or
      13                 :            : 
      14                 :            :      * the GNU General Public License as published by the Free
      15                 :            :        Software Foundation; either version 2 of the License, or (at
      16                 :            :        your option) any later version
      17                 :            : 
      18                 :            :    or both in parallel, as here.
      19                 :            : 
      20                 :            :    elfutils is distributed in the hope that it will be useful, but
      21                 :            :    WITHOUT ANY WARRANTY; without even the implied warranty of
      22                 :            :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      23                 :            :    General Public License for more details.
      24                 :            : 
      25                 :            :    You should have received copies of the GNU General Public License and
      26                 :            :    the GNU Lesser General Public License along with this program.  If
      27                 :            :    not, see <http://www.gnu.org/licenses/>.  */
      28                 :            : 
      29                 :            : #ifdef HAVE_CONFIG_H
      30                 :            : # include <config.h>
      31                 :            : #endif
      32                 :            : 
      33                 :            : #include <assert.h>
      34                 :            : #include <gelf.h>
      35                 :            : #include <stddef.h>
      36                 :            : 
      37                 :            : #include "libelfP.h"
      38                 :            : 
      39                 :            : 
      40                 :            : int
      41                 :            : internal_function
      42                 :     159702 : __elf_getphdrnum_rdlock (Elf *elf, size_t *dst)
      43                 :            : {
      44         [ -  + ]:     159702 :  if (unlikely (elf->state.elf64.ehdr == NULL))
      45                 :            :    {
      46                 :            :      /* Maybe no ELF header was created yet.  */
      47                 :          0 :      *dst = 0;
      48                 :          0 :      __libelf_seterrno (ELF_E_WRONG_ORDER_EHDR);
      49                 :          0 :      return -1;
      50                 :            :    }
      51                 :            : 
      52                 :     319404 :  *dst = (elf->class == ELFCLASS32
      53                 :      28630 :          ? elf->state.elf32.ehdr->e_phnum
      54         [ +  + ]:     159702 :          : elf->state.elf64.ehdr->e_phnum);
      55                 :            : 
      56         [ +  + ]:     159702 :  if (*dst == PN_XNUM)
      57                 :            :    {
      58                 :         12 :      const Elf_ScnList *const scns = (elf->class == ELFCLASS32
      59                 :            :                                       ? &elf->state.elf32.scns
      60                 :            :                                       : &elf->state.elf64.scns);
      61                 :            : 
      62                 :            :      /* If there are no section headers, perhaps this is really just 65536
      63                 :            :         written without PN_XNUM support.  Either that or it's bad data.  */
      64                 :            : 
      65         [ -  + ]:         12 :      if (elf->class == ELFCLASS32)
      66                 :            :        {
      67         [ #  # ]:          0 :          if (likely (scns->cnt > 0))
      68                 :            :            {
      69                 :          0 :              Elf_Scn *scn = &elf->state.elf32.scns.data[0];
      70         [ #  # ]:          0 :              Elf32_Shdr *shdr = scn->shdr.e32 ?: __elf32_getshdr_rdlock (scn);
      71         [ #  # ]:          0 :              if (shdr)
      72                 :          0 :                *dst = shdr->sh_info;
      73                 :            :            }
      74                 :            :        }
      75                 :            :      else
      76                 :            :        {
      77         [ -  + ]:         12 :          if (likely (scns->cnt > 0))
      78                 :            :            {
      79                 :         12 :              Elf_Scn *scn = &elf->state.elf64.scns.data[0];
      80         [ +  + ]:         12 :              Elf64_Shdr *shdr = scn->shdr.e64 ?: __elf64_getshdr_rdlock (scn);
      81         [ -  + ]:          2 :              if (shdr)
      82                 :         12 :                *dst = shdr->sh_info;
      83                 :            :            }
      84                 :            :        }
      85                 :            :    }
      86                 :            : 
      87                 :            :  return 0;
      88                 :            : }
      89                 :            : 
      90                 :            : int
      91                 :            : internal_function
      92                 :     142904 : __elf_getphdrnum_chk_rdlock (Elf *elf, size_t *dst)
      93                 :            : {
      94                 :     142904 :   int result = __elf_getphdrnum_rdlock (elf, dst);
      95                 :            : 
      96                 :            :   /* If the phdrs haven't been created or read in yet then do some
      97                 :            :      sanity checking to make sure phnum and phoff are consistent.  */
      98         [ +  + ]:     142904 :   if (elf->state.elf.phdr == NULL)
      99                 :            :     {
     100                 :      32248 :       Elf64_Off off = (elf->class == ELFCLASS32
     101                 :       1904 :                        ? elf->state.elf32.ehdr->e_phoff
     102         [ +  + ]:      16124 :                        : elf->state.elf64.ehdr->e_phoff);
     103         [ +  + ]:      16124 :       if (unlikely (off == 0))
     104                 :            :         {
     105                 :       2328 :           *dst = 0;
     106                 :       2328 :           return result;
     107                 :            :         }
     108                 :            : 
     109         [ -  + ]:      13796 :       if (unlikely (off >= elf->maximum_size))
     110                 :            :         {
     111                 :          0 :           __libelf_seterrno (ELF_E_INVALID_DATA);
     112                 :          0 :           return -1;
     113                 :            :         }
     114                 :            : 
     115                 :            :       /* Check for too many sections.  */
     116                 :      27592 :       size_t phdr_size = (elf->class == ELFCLASS32
     117         [ +  + ]:      13796 :                           ? sizeof (Elf32_Phdr) : sizeof (Elf64_Phdr));
     118         [ -  + ]:      13796 :       if (unlikely (*dst > SIZE_MAX / phdr_size))
     119                 :            :         {
     120                 :          0 :           __libelf_seterrno (ELF_E_INVALID_DATA);
     121                 :          0 :           return -1;
     122                 :            :         }
     123                 :            : 
     124                 :            :       /* Truncated file?  Don't return more than can be indexed.  */
     125         [ +  - ]:      13796 :       if (unlikely (elf->maximum_size - off < *dst * phdr_size))
     126                 :          0 :         *dst = (elf->maximum_size - off) / phdr_size;
     127                 :            :     }
     128                 :            : 
     129                 :            :   return result;
     130                 :            : }
     131                 :            : 
     132                 :            : int
     133                 :      18330 : elf_getphdrnum (Elf *elf, size_t *dst)
     134                 :            : {
     135                 :      18330 :   int result;
     136                 :            : 
     137         [ -  + ]:      18330 :   if (elf == NULL)
     138                 :            :     return -1;
     139                 :            : 
     140         [ -  + ]:      18330 :   if (unlikely (elf->kind != ELF_K_ELF))
     141                 :            :     {
     142                 :          0 :       __libelf_seterrno (ELF_E_INVALID_HANDLE);
     143                 :          0 :       return -1;
     144                 :            :     }
     145                 :            : 
     146                 :      18330 :   rwlock_rdlock (elf->lock);
     147                 :      18330 :   result = __elf_getphdrnum_chk_rdlock (elf, dst);
     148                 :      18330 :   rwlock_unlock (elf->lock);
     149                 :            : 
     150                 :      18330 :   return result;
     151                 :            : }