1 /* CIE reading. 2 Copyright (C) 2009-2010 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 "cfi.h" 55 #include "encoded-value.h" 56 #include <assert.h> 57 #include <search.h> 58 #include <stdlib.h> 59 60 61 static int 62 compare_cie (const void *a, const void *b) 63 { 64 const struct dwarf_cie *cie1 = a; 65 const struct dwarf_cie *cie2 = b; 66 if (cie1->offset < cie2->offset) 67 return -1; 68 if (cie1->offset > cie2->offset) 69 return 1; 70 return 0; 71 } 72 73 /* There is no CIE at OFFSET in the tree. Add it. */ 74 static struct dwarf_cie * 75 intern_new_cie (Dwarf_CFI *cache, Dwarf_Off offset, const Dwarf_CIE *info) 76 { 77 struct dwarf_cie *cie = malloc (sizeof (struct dwarf_cie)); 78 if (cie == NULL) 79 { 80 __libdw_seterrno (DWARF_E_NOMEM); 81 return NULL; 82 } 83 84 cie->offset = offset; 85 cie->code_alignment_factor = info->code_alignment_factor; 86 cie->data_alignment_factor = info->data_alignment_factor; 87 cie->return_address_register = info->return_address_register; 88 89 cie->fde_augmentation_data_size = 0; 90 cie->sized_augmentation_data = false; 91 cie->signal_frame = false; 92 93 cie->fde_encoding = DW_EH_PE_absptr; 94 cie->lsda_encoding = DW_EH_PE_omit; 95 96 /* Grok the augmentation string and its data. */ 97 const uint8_t *data = info->augmentation_data; 98 for (const char *ap = info->augmentation; *ap != '\0'; ++ap) 99 { 100 uint8_t encoding; 101 switch (*ap) 102 { 103 case 'z': 104 cie->sized_augmentation_data = true; 105 continue; 106 107 case 'S': 108 cie->signal_frame = true; 109 continue; 110 111 case 'L': /* LSDA pointer encoding byte. */ 112 cie->lsda_encoding = *data++; 113 if (!cie->sized_augmentation_data) 114 cie->fde_augmentation_data_size 115 += encoded_value_size (&cache->data->d, cache->e_ident, 116 cie->lsda_encoding, NULL); 117 continue; 118 119 case 'R': /* FDE address encoding byte. */ 120 cie->fde_encoding = *data++; 121 continue; 122 123 case 'P': /* Skip personality routine. */ 124 encoding = *data++; 125 data += encoded_value_size (&cache->data->d, cache->e_ident, 126 encoding, data); 127 continue; 128 129 default: 130 /* Unknown augmentation string. If we have 'z' we can ignore it, 131 otherwise we must bail out. */ 132 if (cie->sized_augmentation_data) 133 continue; 134 } 135 /* We only get here when we need to bail out. */ 136 break; 137 } 138 139 if ((cie->fde_encoding & 0x0f) == DW_EH_PE_absptr) 140 { 141 /* Canonicalize encoding to a specific size. */ 142 assert (DW_EH_PE_absptr == 0); 143 144 /* XXX should get from dwarf_next_cfi with v4 header. */ 145 uint_fast8_t address_size 146 = cache->e_ident[EI_CLASS] == ELFCLASS32 ? 4 : 8; 147 switch (address_size) 148 { 149 case 8: 150 cie->fde_encoding |= DW_EH_PE_udata8; 151 break; 152 case 4: 153 cie->fde_encoding |= DW_EH_PE_udata4; 154 break; 155 default: 156 free (cie); 157 __libdw_seterrno (DWARF_E_INVALID_DWARF); 158 return NULL; 159 } 160 } 161 162 /* Save the initial instructions to be played out into initial state. */ 163 cie->initial_instructions = info->initial_instructions; 164 cie->initial_instructions_end = info->initial_instructions_end; 165 cie->initial_state = NULL; 166 167 /* Add the new entry to the search tree. */ 168 if (tsearch (cie, &cache->cie_tree, &compare_cie) == NULL) 169 { 170 free (cie); 171 __libdw_seterrno (DWARF_E_NOMEM); 172 return NULL; 173 } 174 175 return cie; 176 } 177 178 /* Look up a CIE_pointer for random access. */ 179 struct dwarf_cie * 180 internal_function 181 __libdw_find_cie (Dwarf_CFI *cache, Dwarf_Off offset) 182 { 183 const struct dwarf_cie cie_key = { .offset = offset }; 184 struct dwarf_cie **found = tfind (&cie_key, &cache->cie_tree, &compare_cie); 185 if (found != NULL) 186 return *found; 187 188 /* We have not read this CIE yet. Go find it. */ 189 Dwarf_Off next_offset = offset; 190 Dwarf_CFI_Entry entry; 191 int result = INTUSE(dwarf_next_cfi) (cache->e_ident, 192 &cache->data->d, CFI_IS_EH (cache), 193 offset, &next_offset, &entry); 194 if (result != 0 || entry.cie.CIE_id != DW_CIE_ID_64) 195 { 196 __libdw_seterrno (DWARF_E_INVALID_DWARF); 197 return NULL; 198 } 199 200 /* If this happened to be what we would have read next, notice it. */ 201 if (cache->next_offset == offset) 202 cache->next_offset = next_offset; 203 204 return intern_new_cie (cache, offset, &entry.cie); 205 } 206 207 /* Enter a CIE encountered while reading through for FDEs. */ 208 void 209 internal_function 210 __libdw_intern_cie (Dwarf_CFI *cache, Dwarf_Off offset, const Dwarf_CIE *info) 211 { 212 const struct dwarf_cie cie_key = { .offset = offset }; 213 struct dwarf_cie **found = tfind (&cie_key, &cache->cie_tree, &compare_cie); 214 if (found == NULL) 215 /* We have not read this CIE yet. Enter it. */ 216 (void) intern_new_cie (cache, offset, info); 217 } 218
