Ulrich Drepper | b08d5a8 | 2005-07-26 05:00:05 +0000 | [diff] [blame^] | 1 | /* Get frame descriptions. GCC version using .eh_frame. |
| 2 | Copyright (C) 2000, 2001, 2002 Red Hat, Inc. |
| 3 | Written by Ulrich Drepper <drepper@redhat.com>, 2000. |
| 4 | |
| 5 | This program is Open Source software; you can redistribute it and/or |
| 6 | modify it under the terms of the Open Software License version 1.0 as |
| 7 | published by the Open Source Initiative. |
| 8 | |
| 9 | You should have received a copy of the Open Software License along |
| 10 | with this program; if not, you may obtain a copy of the Open Software |
| 11 | License version 1.0 from http://www.opensource.org/licenses/osl.php or |
| 12 | by writing the Open Source Initiative c/o Lawrence Rosen, Esq., |
| 13 | 3001 King Ranch Road, Ukiah, CA 95482. */ |
| 14 | |
| 15 | #ifdef HAVE_CONFIG_H |
| 16 | # include <config.h> |
| 17 | #endif |
| 18 | |
| 19 | #include <stdlib.h> |
| 20 | #include <string.h> |
| 21 | |
| 22 | #include <libdwarfP.h> |
| 23 | |
| 24 | |
| 25 | struct cielist |
| 26 | { |
| 27 | Dwarf_Cie cie; |
| 28 | struct cielist *next; |
| 29 | }; |
| 30 | |
| 31 | |
| 32 | struct fdelist |
| 33 | { |
| 34 | Dwarf_Fde fde; |
| 35 | Dwarf_Small *cie_id_ptr; |
| 36 | struct fdelist *next; |
| 37 | }; |
| 38 | |
| 39 | |
| 40 | int |
| 41 | dwarf_get_fde_list_eh (dbg, cie_data, cie_element_count, fde_data, |
| 42 | fde_element_count, error) |
| 43 | Dwarf_Debug dbg; |
| 44 | Dwarf_Cie **cie_data; |
| 45 | Dwarf_Signed *cie_element_count; |
| 46 | Dwarf_Fde **fde_data; |
| 47 | Dwarf_Signed *fde_element_count; |
| 48 | Dwarf_Error *error; |
| 49 | { |
| 50 | Dwarf_Small *readp; |
| 51 | Dwarf_Small *readendp; |
| 52 | struct cielist *cielist = NULL; |
| 53 | struct cielist *copy_cielist; |
| 54 | unsigned int ncielist = 0; |
| 55 | struct fdelist *fdelist = NULL; |
| 56 | unsigned int nfdelist = 0; |
| 57 | |
| 58 | if (dbg->sections[IDX_eh_frame].addr == NULL) |
| 59 | return DW_DLV_NO_ENTRY; |
| 60 | |
| 61 | readp = (Dwarf_Small *) dbg->sections[IDX_eh_frame].addr; |
| 62 | readendp = readp + dbg->sections[IDX_eh_frame].size; |
| 63 | |
| 64 | while (readp < readendp) |
| 65 | { |
| 66 | /* Each CIE contains the following: |
| 67 | |
| 68 | 1. CIE_length (initial length) |
| 69 | |
| 70 | A constant that gives the number of bytes of the CIE |
| 71 | structure, not including the length field, itself [...]. |
| 72 | |
| 73 | 2. CIE_id |
| 74 | |
| 75 | A constant that is used to distinguish CIEs from FDEs. |
| 76 | |
| 77 | 3. version (ubyte) [...] |
| 78 | |
| 79 | 4. augmentation (array of ubyte) |
| 80 | |
| 81 | A null-terminated string that identifies the augmentation to |
| 82 | this CIE or to the FDEs that use it. |
| 83 | |
| 84 | 5. code_alignment_factor (unsigned LEB128) |
| 85 | |
| 86 | A constant that is factored out of all advance location |
| 87 | instructions (see below). |
| 88 | |
| 89 | 6. data_alignment_factor (signed LEB128) |
| 90 | |
| 91 | A constant that is factored out of all offset instructions |
| 92 | [...]. |
| 93 | |
| 94 | 7. return_address_register (ubyte) |
| 95 | |
| 96 | A constant that indicates which column in the rule table |
| 97 | represents the return address of the function. |
| 98 | |
| 99 | 8. initial_instructions (array of ubyte) [...] */ |
| 100 | Dwarf_Small *fde_cie_start; |
| 101 | Dwarf_Small *readstartp; |
| 102 | Dwarf_Small *cie_id_ptr; |
| 103 | Dwarf_Unsigned length; |
| 104 | unsigned int address_size; |
| 105 | Dwarf_Unsigned start_offset; |
| 106 | Dwarf_Unsigned cie_id; |
| 107 | |
| 108 | /* Remember where this entry started. */ |
| 109 | fde_cie_start = readp; |
| 110 | start_offset = (readp |
| 111 | - (Dwarf_Small *) dbg->sections[IDX_eh_frame].addr); |
| 112 | |
| 113 | length = read_4ubyte_unaligned (dbg, readp); |
| 114 | address_size = 4; |
| 115 | readp += 4; |
| 116 | if (length == 0xffffffff) |
| 117 | { |
| 118 | length = read_8ubyte_unaligned (dbg, readp); |
| 119 | readp += 8; |
| 120 | address_size = 8; |
| 121 | } |
| 122 | readstartp = readp; |
| 123 | |
| 124 | /* Requirement from the DWARF specification. */ |
| 125 | if (unlikely (length % address_size != 0)) |
| 126 | { |
| 127 | /* XXX Free resources. */ |
| 128 | __libdwarf_error (dbg, error, DW_E_INVALID_DWARF); |
| 129 | return DW_DLV_ERROR; |
| 130 | } |
| 131 | |
| 132 | /* No more entries. */ |
| 133 | if (length == 0) |
| 134 | break; |
| 135 | |
| 136 | cie_id_ptr = readp; |
| 137 | if (address_size == 4) |
| 138 | { |
| 139 | cie_id = read_4sbyte_unaligned (dbg, readp); |
| 140 | readp += 4; |
| 141 | } |
| 142 | else |
| 143 | { |
| 144 | cie_id = read_8sbyte_unaligned (dbg, readp); |
| 145 | readp += 8; |
| 146 | } |
| 147 | |
| 148 | /* Now we can distinguish between CIEs and FDEs. gcc uses 0 to |
| 149 | signal the record is a CIE. */ |
| 150 | if (cie_id == 0) |
| 151 | { |
| 152 | char *augmentation; |
| 153 | Dwarf_Unsigned code_alignment_factor; |
| 154 | Dwarf_Signed data_alignment_factor; |
| 155 | Dwarf_Small *initial_instructions; |
| 156 | Dwarf_Small return_address_register; |
| 157 | struct cielist *new_cie; |
| 158 | |
| 159 | if (unlikely (*readp++ != CIE_VERSION)) |
| 160 | { |
| 161 | __libdwarf_error (dbg, error, DW_E_INVALID_DWARF); |
| 162 | return DW_DLV_ERROR; |
| 163 | } |
| 164 | |
| 165 | augmentation = (char *) readp; |
| 166 | readp += strlen (augmentation) + 1; |
| 167 | |
| 168 | if (strcmp (augmentation, "") == 0) |
| 169 | { |
| 170 | get_uleb128 (code_alignment_factor, readp); |
| 171 | get_sleb128 (data_alignment_factor, readp); |
| 172 | return_address_register = *readp++; |
| 173 | initial_instructions = readp; |
| 174 | } |
| 175 | else if (strcmp (augmentation, "eh") == 0) |
| 176 | { |
| 177 | /* GCC exception handling. It has an extra field next |
| 178 | which is the address of a exception table. We ignore |
| 179 | this value since it's only used at runtime by the |
| 180 | exception handling. */ |
| 181 | readp += address_size; |
| 182 | |
| 183 | /* Now the standard fields. */ |
| 184 | get_uleb128 (code_alignment_factor, readp); |
| 185 | get_sleb128 (data_alignment_factor, readp); |
| 186 | return_address_register = *readp++; |
| 187 | initial_instructions = readp; |
| 188 | } |
| 189 | else |
| 190 | { |
| 191 | /* We don't know this augmentation. Skip the rest. The |
| 192 | specification says that nothing after the augmentation |
| 193 | string is usable. */ |
| 194 | code_alignment_factor = 0; |
| 195 | data_alignment_factor = 0; |
| 196 | return_address_register = 0; |
| 197 | initial_instructions = NULL; |
| 198 | } |
| 199 | |
| 200 | /* Go to the next record. */ |
| 201 | readp = readstartp + length; |
| 202 | |
| 203 | /* Create the new CIE record. */ |
| 204 | new_cie = (struct cielist *) alloca (sizeof (struct cielist)); |
| 205 | new_cie->cie = (Dwarf_Cie) malloc (sizeof (struct Dwarf_Cie_s)); |
| 206 | if (new_cie->cie == NULL) |
| 207 | { |
| 208 | __libdwarf_error (dbg, error, DW_E_NOMEM); |
| 209 | return DW_DLV_ERROR; |
| 210 | } |
| 211 | |
| 212 | new_cie->cie->dbg = dbg; |
| 213 | new_cie->cie->length = length; |
| 214 | new_cie->cie->augmentation = augmentation; |
| 215 | new_cie->cie->code_alignment_factor = code_alignment_factor; |
| 216 | new_cie->cie->data_alignment_factor = data_alignment_factor; |
| 217 | new_cie->cie->return_address_register = return_address_register; |
| 218 | new_cie->cie->initial_instructions = initial_instructions; |
| 219 | new_cie->cie->initial_instructions_length = |
| 220 | readp - initial_instructions; |
| 221 | |
| 222 | new_cie->cie->offset = start_offset; |
| 223 | new_cie->cie->index = ncielist; |
| 224 | new_cie->next = cielist; |
| 225 | cielist = new_cie; |
| 226 | ++ncielist; |
| 227 | } |
| 228 | else |
| 229 | { |
| 230 | Dwarf_Addr initial_location; |
| 231 | Dwarf_Unsigned address_range; |
| 232 | Dwarf_Small *instructions; |
| 233 | struct fdelist *new_fde; |
| 234 | struct cielist *cie; |
| 235 | |
| 236 | if (address_size == 4) |
| 237 | { |
| 238 | initial_location = read_4ubyte_unaligned (dbg, readp); |
| 239 | readp += 4; |
| 240 | address_range = read_4ubyte_unaligned (dbg, readp); |
| 241 | readp += 4; |
| 242 | } |
| 243 | else |
| 244 | { |
| 245 | initial_location = read_8ubyte_unaligned (dbg, readp); |
| 246 | readp += 8; |
| 247 | address_range = read_8ubyte_unaligned (dbg, readp); |
| 248 | readp += 8; |
| 249 | } |
| 250 | |
| 251 | instructions = readp; |
| 252 | |
| 253 | /* Go to the next record. */ |
| 254 | readp = readstartp + length; |
| 255 | |
| 256 | /* Create the new FDE record. */ |
| 257 | new_fde = (struct fdelist *) alloca (sizeof (struct fdelist)); |
| 258 | new_fde->fde = (Dwarf_Fde) malloc (sizeof (struct Dwarf_Fde_s)); |
| 259 | if (new_fde->fde == NULL) |
| 260 | { |
| 261 | __libdwarf_error (dbg, error, DW_E_NOMEM); |
| 262 | return DW_DLV_ERROR; |
| 263 | } |
| 264 | |
| 265 | new_fde->fde->initial_location = initial_location; |
| 266 | new_fde->fde->address_range = address_range; |
| 267 | new_fde->fde->instructions = instructions; |
| 268 | new_fde->fde->instructions_length = readp - instructions; |
| 269 | new_fde->fde->fde_bytes = fde_cie_start; |
| 270 | new_fde->fde->fde_byte_length = readstartp + length - fde_cie_start; |
| 271 | new_fde->fde->cie = NULL; |
| 272 | new_fde->cie_id_ptr = cie_id_ptr; |
| 273 | |
| 274 | for (cie = cielist; cie != NULL; cie = cie->next) |
| 275 | /* This test takes the non-standard way of using the CIE ID |
| 276 | in the GNU .eh_frame sectio into account. Instead of being |
| 277 | a direct offset in the section it is a offset from the |
| 278 | location of the FDE'S CIE ID value itself to the CIE entry. */ |
| 279 | if (cie->cie->offset |
| 280 | == (size_t) (cie_id_ptr - cie_id |
| 281 | - (Dwarf_Small *) dbg->sections[IDX_eh_frame].addr)) |
| 282 | { |
| 283 | new_fde->fde->cie = cie->cie; |
| 284 | break; |
| 285 | } |
| 286 | |
| 287 | new_fde->fde->offset = cie_id; |
| 288 | new_fde->next = fdelist; |
| 289 | fdelist = new_fde; |
| 290 | ++nfdelist; |
| 291 | } |
| 292 | } |
| 293 | |
| 294 | /* There must always be at least one CIE. */ |
| 295 | if (unlikely (ncielist == 0)) |
| 296 | { |
| 297 | __libdwarf_error (dbg, error, DW_E_INVALID_DWARF); |
| 298 | return DW_DLV_ERROR; |
| 299 | } |
| 300 | |
| 301 | /* Create the lists. */ |
| 302 | *cie_data = (Dwarf_Cie *) malloc (ncielist * sizeof (struct Dwarf_Cie_s)); |
| 303 | if (nfdelist > 0) |
| 304 | *fde_data = (Dwarf_Fde *) malloc (nfdelist * sizeof (struct Dwarf_Fde_s)); |
| 305 | else |
| 306 | *fde_data = NULL; |
| 307 | if ((nfdelist > 0 && *fde_data == NULL) || *cie_data == NULL) |
| 308 | { |
| 309 | __libdwarf_error (dbg, error, DW_E_NOMEM); |
| 310 | return DW_DLV_ERROR; |
| 311 | } |
| 312 | |
| 313 | /* Remember the counts. */ |
| 314 | dbg->fde_cnt = nfdelist; |
| 315 | dbg->cie_cnt = ncielist; |
| 316 | |
| 317 | /* Add all the CIEs. */ |
| 318 | copy_cielist = cielist; |
| 319 | *cie_element_count = ncielist; |
| 320 | while (ncielist-- > 0) |
| 321 | { |
| 322 | (*cie_data)[ncielist] = cielist->cie; |
| 323 | cielist = cielist->next; |
| 324 | } |
| 325 | |
| 326 | /* Add all the FDEs. */ |
| 327 | *fde_element_count = nfdelist; |
| 328 | while (nfdelist-- > 0) |
| 329 | { |
| 330 | (*fde_data)[nfdelist] = fdelist->fde; |
| 331 | |
| 332 | if (fdelist->fde->cie == NULL) |
| 333 | { |
| 334 | /* We have not yet found the CIE. Search now that we know |
| 335 | about all of them. */ |
| 336 | cielist = copy_cielist; |
| 337 | do |
| 338 | { |
| 339 | if (cielist->cie->offset |
| 340 | == (size_t) (fdelist->cie_id_ptr - fdelist->fde->offset |
| 341 | - (Dwarf_Small *) dbg->sections[IDX_eh_frame].addr)) |
| 342 | { |
| 343 | fdelist->fde->cie = cielist->cie; |
| 344 | break; |
| 345 | } |
| 346 | cielist = cielist->next; |
| 347 | } |
| 348 | while (cielist != NULL); |
| 349 | |
| 350 | if (cielist == NULL) |
| 351 | { |
| 352 | /* There is no matching CIE. This is bad. */ |
| 353 | /* XXX Free everything. */ |
| 354 | __libdwarf_error (dbg, error, DW_E_INVALID_DWARF); |
| 355 | return DW_DLV_ERROR; |
| 356 | } |
| 357 | } |
| 358 | |
| 359 | fdelist = fdelist->next; |
| 360 | } |
| 361 | |
| 362 | return DW_DLV_OK; |
| 363 | } |