Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 1 | /* CFI program execution. |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 2 | Copyright (C) 2009-2010, 2014 Red Hat, Inc. |
| 3 | This file is part of elfutils. |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 4 | |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 5 | This file is free software; you can redistribute it and/or modify |
| 6 | it under the terms of either |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 7 | |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 8 | * the GNU Lesser General Public License as published by the Free |
| 9 | Software Foundation; either version 3 of the License, or (at |
| 10 | your option) any later version |
| 11 | |
| 12 | or |
| 13 | |
| 14 | * the GNU General Public License as published by the Free |
| 15 | Software Foundation; either version 2 of the License, or (at |
| 16 | your option) any later version |
| 17 | |
| 18 | or both in parallel, as here. |
| 19 | |
| 20 | elfutils is distributed in the hope that it will be useful, but |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 21 | WITHOUT ANY WARRANTY; without even the implied warranty of |
| 22 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 23 | General Public License for more details. |
| 24 | |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 25 | You should have received copies of the GNU General Public License and |
| 26 | the GNU Lesser General Public License along with this program. If |
| 27 | not, see <http://www.gnu.org/licenses/>. */ |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 28 | |
| 29 | #ifdef HAVE_CONFIG_H |
| 30 | # include <config.h> |
| 31 | #endif |
| 32 | |
| 33 | #include <dwarf.h> |
| 34 | #include "../libebl/libebl.h" |
| 35 | #include "cfi.h" |
| 36 | #include "memory-access.h" |
| 37 | #include "encoded-value.h" |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 38 | #include "system.h" |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 39 | #include <assert.h> |
| 40 | #include <stdlib.h> |
| 41 | #include <string.h> |
| 42 | |
| 43 | #define CFI_PRIMARY_MAX 0x3f |
| 44 | |
| 45 | static Dwarf_Frame * |
| 46 | duplicate_frame_state (const Dwarf_Frame *original, |
| 47 | Dwarf_Frame *prev) |
| 48 | { |
| 49 | size_t size = offsetof (Dwarf_Frame, regs[original->nregs]); |
| 50 | Dwarf_Frame *copy = malloc (size); |
| 51 | if (likely (copy != NULL)) |
| 52 | { |
| 53 | memcpy (copy, original, size); |
| 54 | copy->prev = prev; |
| 55 | } |
| 56 | return copy; |
| 57 | } |
| 58 | |
| 59 | /* Returns a DWARF_E_* error code, usually NOERROR or INVALID_CFI. |
| 60 | Frees *STATE on failure. */ |
| 61 | static int |
| 62 | execute_cfi (Dwarf_CFI *cache, |
| 63 | const struct dwarf_cie *cie, |
| 64 | Dwarf_Frame **state, |
| 65 | const uint8_t *program, const uint8_t *const end, bool abi_cfi, |
| 66 | Dwarf_Addr loc, Dwarf_Addr find_pc) |
| 67 | { |
| 68 | /* The caller should not give us anything out of range. */ |
| 69 | assert (loc <= find_pc); |
| 70 | |
| 71 | int result = DWARF_E_NOERROR; |
| 72 | |
| 73 | #define cfi_assert(ok) do { \ |
| 74 | if (likely (ok)) break; \ |
| 75 | result = DWARF_E_INVALID_CFI; \ |
| 76 | goto out; \ |
| 77 | } while (0) |
| 78 | |
| 79 | Dwarf_Frame *fs = *state; |
| 80 | inline bool enough_registers (Dwarf_Word reg) |
| 81 | { |
| 82 | if (fs->nregs <= reg) |
| 83 | { |
| 84 | size_t size = offsetof (Dwarf_Frame, regs[reg + 1]); |
| 85 | Dwarf_Frame *bigger = realloc (fs, size); |
| 86 | if (unlikely (bigger == NULL)) |
| 87 | { |
| 88 | result = DWARF_E_NOMEM; |
| 89 | return false; |
| 90 | } |
| 91 | else |
| 92 | { |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 93 | eu_static_assert (reg_unspecified == 0); |
| 94 | memset (bigger->regs + bigger->nregs, 0, |
| 95 | (reg + 1 - bigger->nregs) * sizeof bigger->regs[0]); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 96 | bigger->nregs = reg + 1; |
| 97 | fs = bigger; |
| 98 | } |
| 99 | } |
| 100 | return true; |
| 101 | } |
| 102 | |
| 103 | inline void require_cfa_offset (void) |
| 104 | { |
| 105 | if (unlikely (fs->cfa_rule != cfa_offset)) |
| 106 | fs->cfa_rule = cfa_invalid; |
| 107 | } |
| 108 | |
| 109 | #define register_rule(regno, r_rule, r_value) do { \ |
| 110 | if (unlikely (! enough_registers (regno))) \ |
| 111 | goto out; \ |
| 112 | fs->regs[regno].rule = reg_##r_rule; \ |
| 113 | fs->regs[regno].value = (r_value); \ |
| 114 | } while (0) |
| 115 | |
| 116 | while (program < end) |
| 117 | { |
| 118 | uint8_t opcode = *program++; |
| 119 | Dwarf_Word regno; |
| 120 | Dwarf_Word offset; |
| 121 | Dwarf_Word sf_offset; |
| 122 | Dwarf_Word operand = opcode & CFI_PRIMARY_MAX; |
| 123 | switch (opcode) |
| 124 | { |
| 125 | /* These cases move LOC, i.e. "create a new table row". */ |
| 126 | |
| 127 | case DW_CFA_advance_loc1: |
| 128 | operand = *program++; |
| 129 | case DW_CFA_advance_loc + 0 ... DW_CFA_advance_loc + CFI_PRIMARY_MAX: |
| 130 | advance_loc: |
| 131 | loc += operand * cie->code_alignment_factor; |
| 132 | break; |
| 133 | |
| 134 | case DW_CFA_advance_loc2: |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 135 | cfi_assert (program + 2 <= end); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 136 | operand = read_2ubyte_unaligned_inc (cache, program); |
| 137 | goto advance_loc; |
| 138 | case DW_CFA_advance_loc4: |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 139 | cfi_assert (program + 4 <= end); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 140 | operand = read_4ubyte_unaligned_inc (cache, program); |
| 141 | goto advance_loc; |
| 142 | case DW_CFA_MIPS_advance_loc8: |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 143 | cfi_assert (program + 8 <= end); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 144 | operand = read_8ubyte_unaligned_inc (cache, program); |
| 145 | goto advance_loc; |
| 146 | |
| 147 | case DW_CFA_set_loc: |
| 148 | if (likely (!read_encoded_value (cache, cie->fde_encoding, |
| 149 | &program, &loc))) |
| 150 | break; |
| 151 | result = INTUSE(dwarf_errno) (); |
| 152 | goto out; |
| 153 | |
| 154 | /* Now all following cases affect this row, but do not touch LOC. |
| 155 | These cases end with 'continue'. We only get out of the |
| 156 | switch block for the row-copying (LOC-moving) cases above. */ |
| 157 | |
| 158 | case DW_CFA_def_cfa: |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 159 | get_uleb128 (operand, program, end); |
| 160 | cfi_assert (program < end); |
| 161 | get_uleb128 (offset, program, end); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 162 | def_cfa: |
| 163 | fs->cfa_rule = cfa_offset; |
| 164 | fs->cfa_val_reg = operand; |
| 165 | fs->cfa_val_offset = offset; |
| 166 | /* Prime the rest of the Dwarf_Op so dwarf_frame_cfa can use it. */ |
| 167 | fs->cfa_data.offset.atom = DW_OP_bregx; |
| 168 | fs->cfa_data.offset.offset = 0; |
| 169 | continue; |
| 170 | |
| 171 | case DW_CFA_def_cfa_register: |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 172 | get_uleb128 (regno, program, end); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 173 | require_cfa_offset (); |
| 174 | fs->cfa_val_reg = regno; |
| 175 | continue; |
| 176 | |
| 177 | case DW_CFA_def_cfa_sf: |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 178 | get_uleb128 (operand, program, end); |
| 179 | cfi_assert (program < end); |
| 180 | get_sleb128 (sf_offset, program, end); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 181 | offset = sf_offset * cie->data_alignment_factor; |
| 182 | goto def_cfa; |
| 183 | |
| 184 | case DW_CFA_def_cfa_offset: |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 185 | get_uleb128 (offset, program, end); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 186 | def_cfa_offset: |
| 187 | require_cfa_offset (); |
| 188 | fs->cfa_val_offset = offset; |
| 189 | continue; |
| 190 | |
| 191 | case DW_CFA_def_cfa_offset_sf: |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 192 | get_sleb128 (sf_offset, program, end); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 193 | offset = sf_offset * cie->data_alignment_factor; |
| 194 | goto def_cfa_offset; |
| 195 | |
| 196 | case DW_CFA_def_cfa_expression: |
| 197 | /* DW_FORM_block is a ULEB128 length followed by that many bytes. */ |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 198 | get_uleb128 (operand, program, end); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 199 | cfi_assert (operand <= (Dwarf_Word) (end - program)); |
| 200 | fs->cfa_rule = cfa_expr; |
| 201 | fs->cfa_data.expr.data = (unsigned char *) program; |
| 202 | fs->cfa_data.expr.length = operand; |
| 203 | program += operand; |
| 204 | continue; |
| 205 | |
| 206 | case DW_CFA_undefined: |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 207 | get_uleb128 (regno, program, end); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 208 | register_rule (regno, undefined, 0); |
| 209 | continue; |
| 210 | |
| 211 | case DW_CFA_same_value: |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 212 | get_uleb128 (regno, program, end); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 213 | register_rule (regno, same_value, 0); |
| 214 | continue; |
| 215 | |
| 216 | case DW_CFA_offset_extended: |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 217 | get_uleb128 (operand, program, end); |
| 218 | cfi_assert (program < end); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 219 | case DW_CFA_offset + 0 ... DW_CFA_offset + CFI_PRIMARY_MAX: |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 220 | get_uleb128 (offset, program, end); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 221 | offset *= cie->data_alignment_factor; |
| 222 | offset_extended: |
| 223 | register_rule (operand, offset, offset); |
| 224 | continue; |
| 225 | |
| 226 | case DW_CFA_offset_extended_sf: |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 227 | get_uleb128 (operand, program, end); |
| 228 | get_sleb128 (sf_offset, program, end); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 229 | offset_extended_sf: |
| 230 | offset = sf_offset * cie->data_alignment_factor; |
| 231 | goto offset_extended; |
| 232 | |
| 233 | case DW_CFA_GNU_negative_offset_extended: |
| 234 | /* GNU extension obsoleted by DW_CFA_offset_extended_sf. */ |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 235 | get_uleb128 (operand, program, end); |
| 236 | cfi_assert (program < end); |
| 237 | get_uleb128 (offset, program, end); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 238 | sf_offset = -offset; |
| 239 | goto offset_extended_sf; |
| 240 | |
| 241 | case DW_CFA_val_offset: |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 242 | get_uleb128 (operand, program, end); |
| 243 | cfi_assert (program < end); |
| 244 | get_uleb128 (offset, program, end); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 245 | offset *= cie->data_alignment_factor; |
| 246 | val_offset: |
| 247 | register_rule (operand, val_offset, offset); |
| 248 | continue; |
| 249 | |
| 250 | case DW_CFA_val_offset_sf: |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 251 | get_uleb128 (operand, program, end); |
| 252 | cfi_assert (program < end); |
| 253 | get_sleb128 (sf_offset, program, end); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 254 | offset = sf_offset * cie->data_alignment_factor; |
| 255 | goto val_offset; |
| 256 | |
| 257 | case DW_CFA_register: |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 258 | get_uleb128 (regno, program, end); |
| 259 | cfi_assert (program < end); |
| 260 | get_uleb128 (operand, program, end); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 261 | register_rule (regno, register, operand); |
| 262 | continue; |
| 263 | |
| 264 | case DW_CFA_expression: |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 265 | /* Expression rule relies on section data, abi_cfi cannot use it. */ |
| 266 | assert (! abi_cfi); |
| 267 | get_uleb128 (regno, program, end); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 268 | offset = program - (const uint8_t *) cache->data->d.d_buf; |
| 269 | /* DW_FORM_block is a ULEB128 length followed by that many bytes. */ |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 270 | cfi_assert (program < end); |
| 271 | get_uleb128 (operand, program, end); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 272 | cfi_assert (operand <= (Dwarf_Word) (end - program)); |
| 273 | program += operand; |
| 274 | register_rule (regno, expression, offset); |
| 275 | continue; |
| 276 | |
| 277 | case DW_CFA_val_expression: |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 278 | /* Expression rule relies on section data, abi_cfi cannot use it. */ |
| 279 | assert (! abi_cfi); |
| 280 | get_uleb128 (regno, program, end); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 281 | /* DW_FORM_block is a ULEB128 length followed by that many bytes. */ |
| 282 | offset = program - (const uint8_t *) cache->data->d.d_buf; |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 283 | get_uleb128 (operand, program, end); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 284 | cfi_assert (operand <= (Dwarf_Word) (end - program)); |
| 285 | program += operand; |
| 286 | register_rule (regno, val_expression, offset); |
| 287 | continue; |
| 288 | |
| 289 | case DW_CFA_restore_extended: |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 290 | get_uleb128 (operand, program, end); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 291 | case DW_CFA_restore + 0 ... DW_CFA_restore + CFI_PRIMARY_MAX: |
| 292 | |
| 293 | if (unlikely (abi_cfi) && likely (opcode == DW_CFA_restore)) |
| 294 | { |
| 295 | /* Special case hack to give backend abi_cfi a shorthand. */ |
| 296 | cache->default_same_value = true; |
| 297 | continue; |
| 298 | } |
| 299 | |
| 300 | /* This can't be used in the CIE's own initial instructions. */ |
| 301 | cfi_assert (cie->initial_state != NULL); |
| 302 | |
| 303 | /* Restore the CIE's initial rule for this register. */ |
| 304 | if (unlikely (! enough_registers (operand))) |
| 305 | goto out; |
| 306 | if (cie->initial_state->nregs > operand) |
| 307 | fs->regs[operand] = cie->initial_state->regs[operand]; |
| 308 | else |
| 309 | fs->regs[operand].rule = reg_unspecified; |
| 310 | continue; |
| 311 | |
| 312 | case DW_CFA_remember_state: |
| 313 | { |
| 314 | /* Duplicate the state and chain the copy on. */ |
| 315 | Dwarf_Frame *copy = duplicate_frame_state (fs, fs); |
| 316 | if (unlikely (copy == NULL)) |
| 317 | { |
| 318 | result = DWARF_E_NOMEM; |
| 319 | goto out; |
| 320 | } |
| 321 | fs = copy; |
| 322 | continue; |
| 323 | } |
| 324 | |
| 325 | case DW_CFA_restore_state: |
| 326 | { |
| 327 | /* Pop the current state off and use the old one instead. */ |
| 328 | Dwarf_Frame *prev = fs->prev; |
| 329 | cfi_assert (prev != NULL); |
| 330 | free (fs); |
| 331 | fs = prev; |
| 332 | continue; |
| 333 | } |
| 334 | |
| 335 | case DW_CFA_nop: |
| 336 | continue; |
| 337 | |
| 338 | case DW_CFA_GNU_window_save: |
| 339 | /* This is magic shorthand used only by SPARC. It's equivalent |
| 340 | to a bunch of DW_CFA_register and DW_CFA_offset operations. */ |
| 341 | if (unlikely (! enough_registers (31))) |
| 342 | goto out; |
| 343 | for (regno = 8; regno < 16; ++regno) |
| 344 | { |
| 345 | /* Find each %oN in %iN. */ |
| 346 | fs->regs[regno].rule = reg_register; |
| 347 | fs->regs[regno].value = regno + 16; |
| 348 | } |
| 349 | unsigned int address_size = (cache->e_ident[EI_CLASS] == ELFCLASS32 |
| 350 | ? 4 : 8); |
| 351 | for (; regno < 32; ++regno) |
| 352 | { |
| 353 | /* Find %l0..%l7 and %i0..%i7 in a block at the CFA. */ |
| 354 | fs->regs[regno].rule = reg_offset; |
| 355 | fs->regs[regno].value = (regno - 16) * address_size; |
| 356 | } |
| 357 | continue; |
| 358 | |
| 359 | case DW_CFA_GNU_args_size: |
| 360 | /* XXX is this useful for anything? */ |
Elliott Hughes | 0333382 | 2015-02-18 22:19:45 -0800 | [diff] [blame] | 361 | get_uleb128 (operand, program, end); |
Ben Cheng | 25b3c04 | 2013-11-20 14:45:36 -0800 | [diff] [blame] | 362 | continue; |
| 363 | |
| 364 | default: |
| 365 | cfi_assert (false); |
| 366 | continue; |
| 367 | } |
| 368 | |
| 369 | /* We get here only for the cases that have just moved LOC. */ |
| 370 | cfi_assert (cie->initial_state != NULL); |
| 371 | if (find_pc >= loc) |
| 372 | /* This advance has not yet reached FIND_PC. */ |
| 373 | fs->start = loc; |
| 374 | else |
| 375 | { |
| 376 | /* We have just advanced past the address we're looking for. |
| 377 | The state currently described is what we want to see. */ |
| 378 | fs->end = loc; |
| 379 | break; |
| 380 | } |
| 381 | } |
| 382 | |
| 383 | /* "The end of the instruction stream can be thought of as a |
| 384 | DW_CFA_set_loc (initial_location + address_range) instruction." |
| 385 | (DWARF 3.0 Section 6.4.3) |
| 386 | |
| 387 | When we fall off the end of the program without an advance_loc/set_loc |
| 388 | that put us past FIND_PC, the final state left by the FDE program |
| 389 | applies to this address (the caller ensured it was inside the FDE). |
| 390 | This address (FDE->end) is already in FS->end as set by the caller. */ |
| 391 | |
| 392 | #undef register_rule |
| 393 | #undef cfi_assert |
| 394 | |
| 395 | out: |
| 396 | |
| 397 | /* Pop any remembered states left on the stack. */ |
| 398 | while (fs->prev != NULL) |
| 399 | { |
| 400 | Dwarf_Frame *prev = fs->prev; |
| 401 | fs->prev = prev->prev; |
| 402 | free (prev); |
| 403 | } |
| 404 | |
| 405 | if (likely (result == DWARF_E_NOERROR)) |
| 406 | *state = fs; |
| 407 | else |
| 408 | free (fs); |
| 409 | |
| 410 | return result; |
| 411 | } |
| 412 | |
| 413 | static int |
| 414 | cie_cache_initial_state (Dwarf_CFI *cache, struct dwarf_cie *cie) |
| 415 | { |
| 416 | int result = DWARF_E_NOERROR; |
| 417 | |
| 418 | if (likely (cie->initial_state != NULL)) |
| 419 | return result; |
| 420 | |
| 421 | /* This CIE has not been used before. Play out its initial |
| 422 | instructions and cache the initial state that results. |
| 423 | First we'll let the backend fill in the default initial |
| 424 | state for this machine's ABI. */ |
| 425 | |
| 426 | Dwarf_CIE abi_info = { DW_CIE_ID_64, NULL, NULL, 1, 1, -1, "", NULL, 0, 0 }; |
| 427 | |
| 428 | /* Make sure we have a backend handle cached. */ |
| 429 | if (unlikely (cache->ebl == NULL)) |
| 430 | { |
| 431 | cache->ebl = ebl_openbackend (cache->data->s->elf); |
| 432 | if (unlikely (cache->ebl == NULL)) |
| 433 | cache->ebl = (void *) -1l; |
| 434 | } |
| 435 | |
| 436 | /* Fetch the ABI's default CFI program. */ |
| 437 | if (likely (cache->ebl != (void *) -1l) |
| 438 | && unlikely (ebl_abi_cfi (cache->ebl, &abi_info) < 0)) |
| 439 | return DWARF_E_UNKNOWN_ERROR; |
| 440 | |
| 441 | Dwarf_Frame *cie_fs = calloc (1, sizeof (Dwarf_Frame)); |
| 442 | if (unlikely (cie_fs == NULL)) |
| 443 | return DWARF_E_NOMEM; |
| 444 | |
| 445 | /* If the default state of any register is not "undefined" |
| 446 | (i.e. call-clobbered), then the backend supplies instructions |
| 447 | for the standard initial state. */ |
| 448 | if (abi_info.initial_instructions_end > abi_info.initial_instructions) |
| 449 | { |
| 450 | /* Dummy CIE for backend's instructions. */ |
| 451 | struct dwarf_cie abi_cie = |
| 452 | { |
| 453 | .code_alignment_factor = abi_info.code_alignment_factor, |
| 454 | .data_alignment_factor = abi_info.data_alignment_factor, |
| 455 | }; |
| 456 | result = execute_cfi (cache, &abi_cie, &cie_fs, |
| 457 | abi_info.initial_instructions, |
| 458 | abi_info.initial_instructions_end, true, |
| 459 | 0, (Dwarf_Addr) -1l); |
| 460 | } |
| 461 | |
| 462 | /* Now run the CIE's initial instructions. */ |
| 463 | if (cie->initial_instructions_end > cie->initial_instructions |
| 464 | && likely (result == DWARF_E_NOERROR)) |
| 465 | result = execute_cfi (cache, cie, &cie_fs, |
| 466 | cie->initial_instructions, |
| 467 | cie->initial_instructions_end, false, |
| 468 | 0, (Dwarf_Addr) -1l); |
| 469 | |
| 470 | if (likely (result == DWARF_E_NOERROR)) |
| 471 | { |
| 472 | /* Now we have the initial state of things that all |
| 473 | FDEs using this CIE will start from. */ |
| 474 | cie_fs->cache = cache; |
| 475 | cie->initial_state = cie_fs; |
| 476 | } |
| 477 | |
| 478 | return result; |
| 479 | } |
| 480 | |
| 481 | int |
| 482 | internal_function |
| 483 | __libdw_frame_at_address (Dwarf_CFI *cache, struct dwarf_fde *fde, |
| 484 | Dwarf_Addr address, Dwarf_Frame **frame) |
| 485 | { |
| 486 | int result = cie_cache_initial_state (cache, fde->cie); |
| 487 | if (likely (result == DWARF_E_NOERROR)) |
| 488 | { |
| 489 | Dwarf_Frame *fs = duplicate_frame_state (fde->cie->initial_state, NULL); |
| 490 | if (unlikely (fs == NULL)) |
| 491 | return DWARF_E_NOMEM; |
| 492 | |
| 493 | fs->fde = fde; |
| 494 | fs->start = fde->start; |
| 495 | fs->end = fde->end; |
| 496 | |
| 497 | result = execute_cfi (cache, fde->cie, &fs, |
| 498 | fde->instructions, fde->instructions_end, false, |
| 499 | fde->start, address); |
| 500 | if (likely (result == DWARF_E_NOERROR)) |
| 501 | *frame = fs; |
| 502 | } |
| 503 | return result; |
| 504 | } |