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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 : : }