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     4153561 : __libdw_form_val_compute_len (struct Dwarf_CU *cu, unsigned int form,
      43             :                               const unsigned char *valp)
      44             : {
      45     4153561 :   const unsigned char *startp = valp;
      46     4153561 :   const unsigned char *endp = cu->endp;
      47             :   Dwarf_Word u128;
      48             :   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     4153561 :   switch (form)
      53             :     {
      54             :     case DW_FORM_addr:
      55      408760 :       result = cu->address_size;
      56      408760 :       break;
      57             : 
      58             :     case DW_FORM_ref_addr:
      59       62547 :       result = cu->version == 2 ? cu->address_size : cu->offset_size;
      60             :       break;
      61             : 
      62             :     case DW_FORM_strp:
      63             :     case DW_FORM_sec_offset:
      64             :     case DW_FORM_GNU_ref_alt:
      65             :     case DW_FORM_GNU_strp_alt:
      66     3117954 :       result = cu->offset_size;
      67     3117954 :       break;
      68             : 
      69             :     case DW_FORM_block1:
      70        2589 :       if (unlikely ((size_t) (endp - startp) < 1))
      71             :         goto invalid;
      72        2589 :       result = *valp + 1;
      73        2589 :       break;
      74             : 
      75             :     case DW_FORM_block2:
      76           2 :       if (unlikely ((size_t) (endp - startp) < 2))
      77             :         goto invalid;
      78           2 :       result = read_2ubyte_unaligned (cu->dbg, valp) + 2;
      79             :       break;
      80             : 
      81             :     case DW_FORM_block4:
      82           0 :       if (unlikely ((size_t) (endp - startp) < 4))
      83             :         goto invalid;
      84           0 :       result = read_4ubyte_unaligned (cu->dbg, valp) + 4;
      85             :       break;
      86             : 
      87             :     case DW_FORM_block:
      88             :     case DW_FORM_exprloc:
      89      344483 :       get_uleb128 (u128, valp, endp);
      90      344483 :       result = u128 + (valp - startp);
      91      344483 :       break;
      92             : 
      93             :     case DW_FORM_string:
      94             :       {
      95      130290 :         const unsigned char *endstrp = memchr (valp, '\0',
      96      130290 :                                                (size_t) (endp - startp));
      97      130290 :         if (unlikely (endstrp == NULL))
      98             :           goto invalid;
      99      130290 :         result = (size_t) (endstrp - startp) + 1;
     100      130290 :         break;
     101             :       }
     102             : 
     103             :     case DW_FORM_sdata:
     104             :     case DW_FORM_udata:
     105             :     case DW_FORM_ref_udata:
     106       86936 :       get_uleb128 (u128, valp, endp);
     107       86936 :       result = valp - startp;
     108       86936 :       break;
     109             : 
     110             :     case DW_FORM_indirect:
     111           0 :       get_uleb128 (u128, valp, endp);
     112             :       // XXX Is this really correct?
     113           0 :       result = __libdw_form_val_len (cu, u128, valp);
     114           0 :       if (result != (size_t) -1)
     115           0 :         result += valp - startp;
     116             :       else
     117             :         return (size_t) -1;
     118           0 :       break;
     119             : 
     120             :     default:
     121             :       goto invalid;
     122             :     }
     123             : 
     124     4153561 :   if (unlikely (result > (size_t) (endp - startp)))
     125             :     {
     126             :     invalid:
     127           0 :       __libdw_seterrno (DWARF_E_INVALID_DWARF);
     128           0 :       result = (size_t) -1;
     129             :     }
     130             : 
     131             :   return result;
     132             : }