Branch data     Line data    Source code

       1                 :            : /* Helper functions for form handling.
       2                 :            :    Copyright (C) 2003-2009, 2014 Red Hat, Inc.
       3                 :            :    This file is part of elfutils.
       4                 :            :    Written by Ulrich Drepper <drepper@redhat.com>, 2003.
       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 <dwarf.h>
      35                 :            : #include <string.h>
      36                 :            : 
      37                 :            : #include "libdwP.h"
      38                 :            : 
      39                 :            : 
      40                 :            : size_t
      41                 :            : internal_function
      42                 :   52532348 : __libdw_form_val_compute_len (struct Dwarf_CU *cu, unsigned int form,
      43                 :            :                               const unsigned char *valp)
      44                 :            : {
      45                 :   52532348 :   const unsigned char *startp = valp;
      46                 :   52532348 :   const unsigned char *endp = cu->endp;
      47                 :   52532348 :   Dwarf_Word u128;
      48                 :   52532348 :   size_t result;
      49                 :            : 
      50                 :            :   /* NB: This doesn't cover constant form lengths, which are
      51                 :            :      already handled by the inlined __libdw_form_val_len.  */
      52   [ +  +  +  +  :   52532348 :   switch (form)
          -  -  +  +  +  
                   -  - ]
      53                 :            :     {
      54                 :    6708748 :     case DW_FORM_addr:
      55                 :    6708748 :       result = cu->address_size;
      56                 :    6708748 :       break;
      57                 :            : 
      58                 :        452 :     case DW_FORM_ref_addr:
      59         [ -  + ]:        452 :       result = cu->version == 2 ? cu->address_size : cu->offset_size;
      60                 :            :       break;
      61                 :            : 
      62                 :   37610728 :     case DW_FORM_strp:
      63                 :            :     case DW_FORM_strp_sup:
      64                 :            :     case DW_FORM_line_strp:
      65                 :            :     case DW_FORM_sec_offset:
      66                 :            :     case DW_FORM_GNU_ref_alt:
      67                 :            :     case DW_FORM_GNU_strp_alt:
      68                 :   37610728 :       result = cu->offset_size;
      69                 :   37610728 :       break;
      70                 :            : 
      71                 :       7636 :     case DW_FORM_block1:
      72         [ -  + ]:       7636 :       if (unlikely ((size_t) (endp - startp) < 1))
      73                 :          0 :         goto invalid;
      74                 :       7636 :       result = *valp + 1;
      75                 :       7636 :       break;
      76                 :            : 
      77                 :          0 :     case DW_FORM_block2:
      78         [ #  # ]:          0 :       if (unlikely ((size_t) (endp - startp) < 2))
      79                 :          0 :         goto invalid;
      80         [ #  # ]:          0 :       result = read_2ubyte_unaligned (cu->dbg, valp) + 2;
      81                 :            :       break;
      82                 :            : 
      83                 :          0 :     case DW_FORM_block4:
      84         [ #  # ]:          0 :       if (unlikely ((size_t) (endp - startp) < 4))
      85                 :          0 :         goto invalid;
      86         [ #  # ]:          0 :       result = read_4ubyte_unaligned (cu->dbg, valp) + 4;
      87                 :            :       break;
      88                 :            : 
      89                 :    5552322 :     case DW_FORM_block:
      90                 :            :     case DW_FORM_exprloc:
      91         [ -  + ]:    5552322 :       if (valp >= endp)
      92                 :          0 :        goto invalid;
      93                 :    5552322 :       get_uleb128 (u128, valp, endp);
      94                 :    5552322 :       result = u128 + (valp - startp);
      95                 :    5552322 :       break;
      96                 :            : 
      97                 :    1769982 :     case DW_FORM_string:
      98                 :            :       {
      99                 :    1769982 :         const unsigned char *endstrp = memchr (valp, '\0',
     100                 :    1769982 :                                                (size_t) (endp - startp));
     101         [ -  + ]:    1769982 :         if (unlikely (endstrp == NULL))
     102                 :          0 :           goto invalid;
     103                 :    1769982 :         result = (size_t) (endstrp - startp) + 1;
     104                 :    1769982 :         break;
     105                 :            :       }
     106                 :            : 
     107                 :     882480 :     case DW_FORM_sdata:
     108                 :            :     case DW_FORM_udata:
     109                 :            :     case DW_FORM_ref_udata:
     110                 :            :     case DW_FORM_addrx:
     111                 :            :     case DW_FORM_loclistx:
     112                 :            :     case DW_FORM_rnglistx:
     113                 :            :     case DW_FORM_strx:
     114                 :            :     case DW_FORM_GNU_addr_index:
     115                 :            :     case DW_FORM_GNU_str_index:
     116         [ -  + ]:     882480 :       if (valp >= endp)
     117                 :          0 :        goto invalid;
     118                 :     882480 :       get_uleb128 (u128, valp, endp);
     119                 :     882480 :       result = valp - startp;
     120                 :     882480 :       break;
     121                 :            : 
     122                 :          0 :     case DW_FORM_indirect:
     123                 :            :       /* The amount of data to skip in the DIE is the size of the actual
     124                 :            :          FORM data (which is __libdw_form_val_len) plus the size of the
     125                 :            :          uleb128 encoding that FORM (which is valp - startp).  */
     126         [ #  # ]:          0 :       if (valp >= endp)
     127                 :          0 :         goto invalid;
     128                 :          0 :       get_uleb128 (u128, valp, endp);
     129         [ #  # ]:          0 :       if (*valp == DW_FORM_indirect || *valp == DW_FORM_implicit_const)
     130                 :            :         return (size_t) -1;
     131                 :          0 :       result = __libdw_form_val_len (cu, u128, valp);
     132         [ #  # ]:          0 :       if (result != (size_t) -1)
     133                 :          0 :         result += valp - startp;
     134                 :            :       else
     135                 :            :         return (size_t) -1;
     136                 :          0 :       break;
     137                 :            : 
     138                 :          0 :     default:
     139                 :          0 :       goto invalid;
     140                 :            :     }
     141                 :            : 
     142         [ -  + ]:   52532348 :   if (unlikely (result > (size_t) (endp - startp)))
     143                 :            :     {
     144                 :          0 :     invalid:
     145                 :          0 :       __libdw_seterrno (DWARF_E_INVALID_DWARF);
     146                 :          0 :       result = (size_t) -1;
     147                 :            :     }
     148                 :            : 
     149                 :            :   return result;
     150                 :            : }