1 /* Enumerate the PC ranges covered by a DIE. 2 Copyright (C) 2005, 2007, 2009 Red Hat, Inc. 3 This file is part of Red Hat elfutils. 4 5 Red Hat elfutils is free software; you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by the 7 Free Software Foundation; version 2 of the License. 8 9 Red Hat elfutils is distributed in the hope that it will be useful, but 10 WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 General Public License for more details. 13 14 You should have received a copy of the GNU General Public License along 15 with Red Hat elfutils; if not, write to the Free Software Foundation, 16 Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. 17 18 In addition, as a special exception, Red Hat, Inc. gives You the 19 additional right to link the code of Red Hat elfutils with code licensed 20 under any Open Source Initiative certified open source license 21 (http://www.opensource.org/licenses/index.php) which requires the 22 distribution of source code with any binary distribution and to 23 distribute linked combinations of the two. Non-GPL Code permitted under 24 this exception must only link to the code of Red Hat elfutils through 25 those well defined interfaces identified in the file named EXCEPTION 26 found in the source code files (the "Approved Interfaces"). The files 27 of Non-GPL Code may instantiate templates or use macros or inline 28 functions from the Approved Interfaces without causing the resulting 29 work to be covered by the GNU General Public License. Only Red Hat, 30 Inc. may make changes or additions to the list of Approved Interfaces. 31 Red Hat's grant of this exception is conditioned upon your not adding 32 any new exceptions. If you wish to add a new Approved Interface or 33 exception, please contact Red Hat. You must obey the GNU General Public 34 License in all respects for all of the Red Hat elfutils code and other 35 code used in conjunction with Red Hat elfutils except the Non-GPL Code 36 covered by this exception. If you modify this file, you may extend this 37 exception to your version of the file, but you are not obligated to do 38 so. If you do not wish to provide this exception without modification, 39 you must delete this exception statement from your version and license 40 this file solely under the GPL without exception. 41 42 Red Hat elfutils is an included package of the Open Invention Network. 43 An included package of the Open Invention Network is a package for which 44 Open Invention Network licensees cross-license their patents. No patent 45 license is granted, either expressly or impliedly, by designation as an 46 included package. Should you wish to participate in the Open Invention 47 Network licensing program, please visit www.openinventionnetwork.com 48 <http://www.openinventionnetwork.com>. */ 49 50 #ifdef HAVE_CONFIG_H 51 # include <config.h> 52 #endif 53 54 #include "libdwP.h" 55 #include <dwarf.h> 56 #include <assert.h> 57 58 /* Read up begin/end pair and increment read pointer. 59 - If it's normal range record, set up `*beginp' and `*endp' and return 0. 60 - If it's base address selection record, set up `*basep' and return 1. 61 - If it's end of rangelist, don't set anything and return 2 62 - If an error occurs, don't set anything and return -1. */ 63 internal_function int 64 __libdw_read_begin_end_pair_inc (Dwarf *dbg, int sec_index, 65 unsigned char **addrp, int width, 66 Dwarf_Addr *beginp, Dwarf_Addr *endp, 67 Dwarf_Addr *basep) 68 { 69 Dwarf_Addr escape = (width == 8 ? (Elf64_Addr) -1 70 : (Elf64_Addr) (Elf32_Addr) -1); 71 Dwarf_Addr begin; 72 Dwarf_Addr end; 73 74 unsigned char *addr = *addrp; 75 bool begin_relocated = READ_AND_RELOCATE (__libdw_relocate_address, begin); 76 bool end_relocated = READ_AND_RELOCATE (__libdw_relocate_address, end); 77 *addrp = addr; 78 79 /* Unrelocated escape for begin means base address selection. */ 80 if (begin == escape && !begin_relocated) 81 { 82 if (unlikely (end == escape)) 83 { 84 __libdw_seterrno (DWARF_E_INVALID_DWARF); 85 return -1; 86 } 87 88 if (basep != NULL) 89 *basep = end; 90 return 1; 91 } 92 93 /* Unrelocated pair of zeroes means end of range list. */ 94 if (begin == 0 && end == 0 && !begin_relocated && !end_relocated) 95 return 2; 96 97 /* Don't check for begin_relocated == end_relocated. Serve the data 98 to the client even though it may be buggy. */ 99 *beginp = begin; 100 *endp = end; 101 102 return 0; 103 } 104 105 ptrdiff_t 106 dwarf_ranges (Dwarf_Die *die, ptrdiff_t offset, Dwarf_Addr *basep, 107 Dwarf_Addr *startp, Dwarf_Addr *endp) 108 { 109 if (die == NULL) 110 return -1; 111 112 if (offset == 0 113 /* Usually there is a single contiguous range. */ 114 && INTUSE(dwarf_highpc) (die, endp) == 0 115 && INTUSE(dwarf_lowpc) (die, startp) == 0) 116 /* A offset into .debug_ranges will never be 1, it must be at least a 117 multiple of 4. So we can return 1 as a special case value to mark 118 there are no ranges to look for on the next call. */ 119 return 1; 120 121 if (offset == 1) 122 return 0; 123 124 /* We have to look for a noncontiguous range. */ 125 126 const Elf_Data *d = die->cu->dbg->sectiondata[IDX_debug_ranges]; 127 if (d == NULL && offset != 0) 128 { 129 __libdw_seterrno (DWARF_E_NO_DEBUG_RANGES); 130 return -1; 131 } 132 133 unsigned char *readp; 134 unsigned char *readendp; 135 if (offset == 0) 136 { 137 Dwarf_Attribute attr_mem; 138 Dwarf_Attribute *attr = INTUSE(dwarf_attr) (die, DW_AT_ranges, 139 &attr_mem); 140 if (attr == NULL) 141 /* No PC attributes in this DIE at all, so an empty range list. */ 142 return 0; 143 144 Dwarf_Word start_offset; 145 if ((readp = __libdw_formptr (attr, IDX_debug_ranges, 146 DWARF_E_NO_DEBUG_RANGES, 147 &readendp, &start_offset)) == NULL) 148 return -1; 149 150 offset = start_offset; 151 assert ((Dwarf_Word) offset == start_offset); 152 153 /* Fetch the CU's base address. */ 154 Dwarf_Die cudie = CUDIE (attr->cu); 155 156 /* Find the base address of the compilation unit. It will 157 normally be specified by DW_AT_low_pc. In DWARF-3 draft 4, 158 the base address could be overridden by DW_AT_entry_pc. It's 159 been removed, but GCC emits DW_AT_entry_pc and not DW_AT_lowpc 160 for compilation units with discontinuous ranges. */ 161 if (unlikely (INTUSE(dwarf_lowpc) (&cudie, basep) != 0) 162 && INTUSE(dwarf_formaddr) (INTUSE(dwarf_attr) (&cudie, 163 DW_AT_entry_pc, 164 &attr_mem), 165 basep) != 0) 166 { 167 if (INTUSE(dwarf_errno) () == 0) 168 { 169 invalid: 170 __libdw_seterrno (DWARF_E_INVALID_DWARF); 171 } 172 return -1; 173 } 174 } 175 else 176 { 177 if (__libdw_offset_in_section (die->cu->dbg, 178 IDX_debug_ranges, offset, 1)) 179 return -1l; 180 181 readp = d->d_buf + offset; 182 readendp = d->d_buf + d->d_size; 183 } 184 185 next: 186 if (readendp - readp < die->cu->address_size * 2) 187 goto invalid; 188 189 Dwarf_Addr begin; 190 Dwarf_Addr end; 191 192 switch (__libdw_read_begin_end_pair_inc (die->cu->dbg, IDX_debug_ranges, 193 &readp, die->cu->address_size, 194 &begin, &end, basep)) 195 { 196 case 0: 197 break; 198 case 1: 199 goto next; 200 case 2: 201 return 0; 202 default: 203 return -1l; 204 } 205 206 /* We have an address range entry. */ 207 *startp = *basep + begin; 208 *endp = *basep + end; 209 return readp - (unsigned char *) d->d_buf; 210 } 211 INTDEF (dwarf_ranges) 212
