1 /* libunwind - a platform-independent unwind library 2 Copyright (c) 2003-2005 Hewlett-Packard Development Company, L.P. 3 Contributed by David Mosberger-Tang <davidm@hpl.hp.com> 4 5 This file is part of libunwind. 6 7 Permission is hereby granted, free of charge, to any person obtaining 8 a copy of this software and associated documentation files (the 9 "Software"), to deal in the Software without restriction, including 10 without limitation the rights to use, copy, modify, merge, publish, 11 distribute, sublicense, and/or sell copies of the Software, and to 12 permit persons to whom the Software is furnished to do so, subject to 13 the following conditions: 14 15 The above copyright notice and this permission notice shall be 16 included in all copies or substantial portions of the Software. 17 18 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 19 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 20 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 21 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 22 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 23 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 24 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ 25 26 #ifndef dwarf_h 27 #define dwarf_h 28 29 #include <link.h> 30 #include <pthread.h> 31 32 #include "libunwind.h" 33 #include "private/mempool.h" 34 #include "private/dwarf-config.h" 35 36 struct elf_dyn_info; 37 struct as_elf_dyn_info; 38 39 /* DWARF expression opcodes. */ 40 41 typedef enum 42 { 43 DW_OP_addr = 0x03, 44 DW_OP_deref = 0x06, 45 DW_OP_const1u = 0x08, 46 DW_OP_const1s = 0x09, 47 DW_OP_const2u = 0x0a, 48 DW_OP_const2s = 0x0b, 49 DW_OP_const4u = 0x0c, 50 DW_OP_const4s = 0x0d, 51 DW_OP_const8u = 0x0e, 52 DW_OP_const8s = 0x0f, 53 DW_OP_constu = 0x10, 54 DW_OP_consts = 0x11, 55 DW_OP_dup = 0x12, 56 DW_OP_drop = 0x13, 57 DW_OP_over = 0x14, 58 DW_OP_pick = 0x15, 59 DW_OP_swap = 0x16, 60 DW_OP_rot = 0x17, 61 DW_OP_xderef = 0x18, 62 DW_OP_abs = 0x19, 63 DW_OP_and = 0x1a, 64 DW_OP_div = 0x1b, 65 DW_OP_minus = 0x1c, 66 DW_OP_mod = 0x1d, 67 DW_OP_mul = 0x1e, 68 DW_OP_neg = 0x1f, 69 DW_OP_not = 0x20, 70 DW_OP_or = 0x21, 71 DW_OP_plus = 0x22, 72 DW_OP_plus_uconst = 0x23, 73 DW_OP_shl = 0x24, 74 DW_OP_shr = 0x25, 75 DW_OP_shra = 0x26, 76 DW_OP_xor = 0x27, 77 DW_OP_skip = 0x2f, 78 DW_OP_bra = 0x28, 79 DW_OP_eq = 0x29, 80 DW_OP_ge = 0x2a, 81 DW_OP_gt = 0x2b, 82 DW_OP_le = 0x2c, 83 DW_OP_lt = 0x2d, 84 DW_OP_ne = 0x2e, 85 DW_OP_lit0 = 0x30, 86 DW_OP_lit1, DW_OP_lit2, DW_OP_lit3, DW_OP_lit4, DW_OP_lit5, 87 DW_OP_lit6, DW_OP_lit7, DW_OP_lit8, DW_OP_lit9, DW_OP_lit10, 88 DW_OP_lit11, DW_OP_lit12, DW_OP_lit13, DW_OP_lit14, DW_OP_lit15, 89 DW_OP_lit16, DW_OP_lit17, DW_OP_lit18, DW_OP_lit19, DW_OP_lit20, 90 DW_OP_lit21, DW_OP_lit22, DW_OP_lit23, DW_OP_lit24, DW_OP_lit25, 91 DW_OP_lit26, DW_OP_lit27, DW_OP_lit28, DW_OP_lit29, DW_OP_lit30, 92 DW_OP_lit31, 93 DW_OP_reg0 = 0x50, 94 DW_OP_reg1, DW_OP_reg2, DW_OP_reg3, DW_OP_reg4, DW_OP_reg5, 95 DW_OP_reg6, DW_OP_reg7, DW_OP_reg8, DW_OP_reg9, DW_OP_reg10, 96 DW_OP_reg11, DW_OP_reg12, DW_OP_reg13, DW_OP_reg14, DW_OP_reg15, 97 DW_OP_reg16, DW_OP_reg17, DW_OP_reg18, DW_OP_reg19, DW_OP_reg20, 98 DW_OP_reg21, DW_OP_reg22, DW_OP_reg23, DW_OP_reg24, DW_OP_reg25, 99 DW_OP_reg26, DW_OP_reg27, DW_OP_reg28, DW_OP_reg29, DW_OP_reg30, 100 DW_OP_reg31, 101 DW_OP_breg0 = 0x70, 102 DW_OP_breg1, DW_OP_breg2, DW_OP_breg3, DW_OP_breg4, DW_OP_breg5, 103 DW_OP_breg6, DW_OP_breg7, DW_OP_breg8, DW_OP_breg9, DW_OP_breg10, 104 DW_OP_breg11, DW_OP_breg12, DW_OP_breg13, DW_OP_breg14, DW_OP_breg15, 105 DW_OP_breg16, DW_OP_breg17, DW_OP_breg18, DW_OP_breg19, DW_OP_breg20, 106 DW_OP_breg21, DW_OP_breg22, DW_OP_breg23, DW_OP_breg24, DW_OP_breg25, 107 DW_OP_breg26, DW_OP_breg27, DW_OP_breg28, DW_OP_breg29, DW_OP_breg30, 108 DW_OP_breg31, 109 DW_OP_regx = 0x90, 110 DW_OP_fbreg = 0x91, 111 DW_OP_bregx = 0x92, 112 DW_OP_piece = 0x93, 113 DW_OP_deref_size = 0x94, 114 DW_OP_xderef_size = 0x95, 115 DW_OP_nop = 0x96, 116 DW_OP_push_object_address = 0x97, 117 DW_OP_call2 = 0x98, 118 DW_OP_call4 = 0x99, 119 DW_OP_call_ref = 0x9a, 120 DW_OP_lo_user = 0xe0, 121 DW_OP_hi_user = 0xff 122 } 123 dwarf_expr_op_t; 124 125 #define DWARF_CIE_VERSION 3 /* GCC emits version 1??? */ 126 127 #define DWARF_CFA_OPCODE_MASK 0xc0 128 #define DWARF_CFA_OPERAND_MASK 0x3f 129 130 typedef enum 131 { 132 DW_CFA_advance_loc = 0x40, 133 DW_CFA_offset = 0x80, 134 DW_CFA_restore = 0xc0, 135 DW_CFA_nop = 0x00, 136 DW_CFA_set_loc = 0x01, 137 DW_CFA_advance_loc1 = 0x02, 138 DW_CFA_advance_loc2 = 0x03, 139 DW_CFA_advance_loc4 = 0x04, 140 DW_CFA_offset_extended = 0x05, 141 DW_CFA_restore_extended = 0x06, 142 DW_CFA_undefined = 0x07, 143 DW_CFA_same_value = 0x08, 144 DW_CFA_register = 0x09, 145 DW_CFA_remember_state = 0x0a, 146 DW_CFA_restore_state = 0x0b, 147 DW_CFA_def_cfa = 0x0c, 148 DW_CFA_def_cfa_register = 0x0d, 149 DW_CFA_def_cfa_offset = 0x0e, 150 DW_CFA_def_cfa_expression = 0x0f, 151 DW_CFA_expression = 0x10, 152 DW_CFA_offset_extended_sf = 0x11, 153 DW_CFA_def_cfa_sf = 0x12, 154 DW_CFA_def_cfa_offset_sf = 0x13, 155 DW_CFA_val_expression = 0x16, 156 DW_CFA_lo_user = 0x1c, 157 DW_CFA_MIPS_advance_loc8 = 0x1d, 158 DW_CFA_GNU_window_save = 0x2d, 159 DW_CFA_GNU_args_size = 0x2e, 160 DW_CFA_GNU_negative_offset_extended = 0x2f, 161 DW_CFA_hi_user = 0x3c 162 } 163 dwarf_cfa_t; 164 165 /* DWARF Pointer-Encoding (PEs). 166 167 Pointer-Encodings were invented for the GCC exception-handling 168 support for C++, but they represent a rather generic way of 169 describing the format in which an address/pointer is stored and 170 hence we include the definitions here, in the main dwarf.h file. 171 The Pointer-Encoding format is partially documented in Linux Base 172 Spec v1.3 (http://www.linuxbase.org/spec/). The rest is reverse 173 engineered from GCC. 174 */ 175 #define DW_EH_PE_FORMAT_MASK 0x0f /* format of the encoded value */ 176 #define DW_EH_PE_APPL_MASK 0x70 /* how the value is to be applied */ 177 /* Flag bit. If set, the resulting pointer is the address of the word 178 that contains the final address. */ 179 #define DW_EH_PE_indirect 0x80 180 181 /* Pointer-encoding formats: */ 182 #define DW_EH_PE_omit 0xff 183 #define DW_EH_PE_ptr 0x00 /* pointer-sized unsigned value */ 184 #define DW_EH_PE_uleb128 0x01 /* unsigned LE base-128 value */ 185 #define DW_EH_PE_udata2 0x02 /* unsigned 16-bit value */ 186 #define DW_EH_PE_udata4 0x03 /* unsigned 32-bit value */ 187 #define DW_EH_PE_udata8 0x04 /* unsigned 64-bit value */ 188 #define DW_EH_PE_sleb128 0x09 /* signed LE base-128 value */ 189 #define DW_EH_PE_sdata2 0x0a /* signed 16-bit value */ 190 #define DW_EH_PE_sdata4 0x0b /* signed 32-bit value */ 191 #define DW_EH_PE_sdata8 0x0c /* signed 64-bit value */ 192 193 /* Pointer-encoding application: */ 194 #define DW_EH_PE_absptr 0x00 /* absolute value */ 195 #define DW_EH_PE_pcrel 0x10 /* rel. to addr. of encoded value */ 196 #define DW_EH_PE_textrel 0x20 /* text-relative (GCC-specific???) */ 197 #define DW_EH_PE_datarel 0x30 /* data-relative */ 198 /* The following are not documented by LSB v1.3, yet they are used by 199 GCC, presumably they aren't documented by LSB since they aren't 200 used on Linux: */ 201 #define DW_EH_PE_funcrel 0x40 /* start-of-procedure-relative */ 202 #define DW_EH_PE_aligned 0x50 /* aligned pointer */ 203 204 extern struct mempool dwarf_reg_state_pool; 205 extern struct mempool dwarf_cie_info_pool; 206 207 typedef enum 208 { 209 DWARF_WHERE_UNDEF, /* register isn't saved at all */ 210 DWARF_WHERE_SAME, /* register has same value as in prev. frame */ 211 DWARF_WHERE_CFAREL, /* register saved at CFA-relative address */ 212 DWARF_WHERE_REG, /* register saved in another register */ 213 DWARF_WHERE_EXPR, /* register saved */ 214 DWARF_WHERE_VAL_EXPR, /* register has computed value */ 215 } 216 dwarf_where_t; 217 218 typedef struct 219 { 220 dwarf_where_t where; /* how is the register saved? */ 221 unw_word_t val; /* where it's saved */ 222 } 223 dwarf_save_loc_t; 224 225 /* For uniformity, we'd like to treat the CFA save-location like any 226 other register save-location, but this doesn't quite work, because 227 the CFA can be expressed as a (REGISTER,OFFSET) pair. To handle 228 this, we use two dwarf_save_loc structures to describe the CFA. 229 The first one (CFA_REG_COLUMN), tells us where the CFA is saved. 230 In the case of DWARF_WHERE_EXPR, the CFA is defined by a DWARF 231 location expression whose address is given by member "val". In the 232 case of DWARF_WHERE_REG, member "val" gives the number of the 233 base-register and the "val" member of DWARF_CFA_OFF_COLUMN gives 234 the offset value. */ 235 #define DWARF_CFA_REG_COLUMN DWARF_NUM_PRESERVED_REGS 236 #define DWARF_CFA_OFF_COLUMN (DWARF_NUM_PRESERVED_REGS + 1) 237 238 typedef struct dwarf_reg_state 239 { 240 struct dwarf_reg_state *next; /* for rs_stack */ 241 dwarf_save_loc_t reg[DWARF_NUM_PRESERVED_REGS + 2]; 242 unw_word_t ip; /* ip this rs is for */ 243 unw_word_t ret_addr_column; /* indicates which column in the rule table represents return address */ 244 unsigned short lru_chain; /* used for least-recently-used chain */ 245 unsigned short coll_chain; /* used for hash collisions */ 246 unsigned short hint; /* hint for next rs to try (or -1) */ 247 unsigned short valid : 1; /* optional machine-dependent signal info */ 248 unsigned short signal_frame : 1; /* optional machine-dependent signal info */ 249 } 250 dwarf_reg_state_t; 251 252 typedef struct dwarf_cie_info 253 { 254 unw_word_t cie_instr_start; /* start addr. of CIE "initial_instructions" */ 255 unw_word_t cie_instr_end; /* end addr. of CIE "initial_instructions" */ 256 unw_word_t fde_instr_start; /* start addr. of FDE "instructions" */ 257 unw_word_t fde_instr_end; /* end addr. of FDE "instructions" */ 258 unw_word_t code_align; /* code-alignment factor */ 259 unw_word_t data_align; /* data-alignment factor */ 260 unw_word_t ret_addr_column; /* column of return-address register */ 261 unw_word_t handler; /* address of personality-routine */ 262 uint16_t abi; 263 uint16_t tag; 264 uint8_t fde_encoding; 265 uint8_t lsda_encoding; 266 unsigned int sized_augmentation : 1; 267 unsigned int have_abi_marker : 1; 268 unsigned int signal_frame : 1; 269 } 270 dwarf_cie_info_t; 271 272 typedef struct dwarf_state_record 273 { 274 unsigned char fde_encoding; 275 unw_word_t args_size; 276 277 dwarf_reg_state_t rs_initial; /* reg-state after CIE instructions */ 278 dwarf_reg_state_t rs_current; /* current reg-state */ 279 } 280 dwarf_state_record_t; 281 282 typedef struct dwarf_cursor 283 { 284 void *as_arg; /* argument to address-space callbacks */ 285 unw_addr_space_t as; /* reference to per-address-space info */ 286 287 unw_word_t cfa; /* canonical frame address; aka frame-/stack-pointer */ 288 unw_word_t ip; /* instruction pointer */ 289 unw_word_t args_size; /* size of arguments */ 290 unw_word_t ret_addr_column; /* column for return-address */ 291 unw_word_t eh_args[UNW_TDEP_NUM_EH_REGS]; 292 unsigned int eh_valid_mask; 293 294 dwarf_loc_t loc[DWARF_NUM_PRESERVED_REGS]; 295 296 unsigned int stash_frames :1; /* stash frames for fast lookup */ 297 unsigned int use_prev_instr :1; /* use previous (= call) or current (= signal) instruction? */ 298 unsigned int pi_valid :1; /* is proc_info valid? */ 299 unsigned int pi_is_dynamic :1; /* proc_info found via dynamic proc info? */ 300 unw_proc_info_t pi; /* info about current procedure */ 301 302 short hint; /* faster lookup of the rs cache */ 303 short prev_rs; 304 } 305 dwarf_cursor_t; 306 307 #define DWARF_LOG_UNW_CACHE_SIZE 7 308 #define DWARF_UNW_CACHE_SIZE (1 << DWARF_LOG_UNW_CACHE_SIZE) 309 310 #define DWARF_LOG_UNW_HASH_SIZE (DWARF_LOG_UNW_CACHE_SIZE + 1) 311 #define DWARF_UNW_HASH_SIZE (1 << DWARF_LOG_UNW_HASH_SIZE) 312 313 typedef unsigned char unw_hash_index_t; 314 315 struct dwarf_rs_cache 316 { 317 pthread_mutex_t lock; 318 unsigned short lru_head; /* index of lead-recently used rs */ 319 unsigned short lru_tail; /* index of most-recently used rs */ 320 321 /* hash table that maps instruction pointer to rs index: */ 322 unsigned short hash[DWARF_UNW_HASH_SIZE]; 323 324 uint32_t generation; /* generation number */ 325 326 /* rs cache: */ 327 dwarf_reg_state_t buckets[DWARF_UNW_CACHE_SIZE]; 328 }; 329 330 /* A list of descriptors for loaded .debug_frame sections. */ 331 332 struct unw_debug_frame_list 333 { 334 /* The start (inclusive) and end (exclusive) of the described region. */ 335 unw_word_t start; 336 unw_word_t end; 337 /* The debug frame itself. */ 338 char *debug_frame; 339 size_t debug_frame_size; 340 /* Index (for binary search). */ 341 struct table_entry *index; 342 size_t index_size; 343 /* Pointer to next descriptor. */ 344 struct unw_debug_frame_list *next; 345 }; 346 347 struct dwarf_callback_data 348 { 349 /* in: */ 350 unw_word_t ip; /* instruction-pointer we're looking for */ 351 unw_proc_info_t *pi; /* proc-info pointer */ 352 int need_unwind_info; 353 /* out: */ 354 int single_fde; /* did we find a single FDE? (vs. a table) */ 355 unw_dyn_info_t di; /* table info (if single_fde is false) */ 356 unw_dyn_info_t di_debug; /* additional table info for .debug_frame */ 357 }; 358 359 extern int dwarf_init (void); 360 361 extern int dwarf_callback (struct dl_phdr_info *info, size_t size, void *ptr); 362 extern int dwarf_find_proc_info (unw_addr_space_t as, unw_word_t ip, 363 unw_proc_info_t *pi, 364 int need_unwind_info, void *arg); 365 366 extern int dwarf_find_debug_frame (int found, unw_dyn_info_t *di_debug, 367 unw_word_t ip, unw_word_t segbase, 368 const char* obj_name, unw_word_t start, 369 unw_word_t end); 370 extern int dwarf_search_unwind_table (unw_addr_space_t as, 371 unw_word_t ip, 372 unw_dyn_info_t *di, 373 unw_proc_info_t *pi, 374 int need_unwind_info, void *arg); 375 extern int dwarf_find_unwind_table (struct elf_dyn_info *edi, unw_addr_space_t as, 376 char *path, unw_word_t segbase, unw_word_t mapoff, 377 unw_word_t ip); 378 extern void dwarf_put_unwind_info (unw_addr_space_t as, 379 unw_proc_info_t *pi, void *arg); 380 extern int dwarf_eval_expr (struct dwarf_cursor *c, unw_word_t *addr, 381 unw_word_t len, unw_word_t *valp, 382 int *is_register); 383 extern int dwarf_extract_proc_info_from_fde (unw_addr_space_t as, 384 unw_accessors_t *a, 385 unw_word_t *fde_addr, 386 unw_proc_info_t *pi, 387 unw_word_t base, 388 int need_unwind_info, 389 int is_debug_frame, 390 void *arg); 391 extern int dwarf_find_save_locs (struct dwarf_cursor *c); 392 extern int dwarf_create_state_record (struct dwarf_cursor *c, 393 dwarf_state_record_t *sr); 394 extern int dwarf_make_proc_info (struct dwarf_cursor *c); 395 extern int dwarf_read_encoded_pointer (unw_addr_space_t as, 396 unw_accessors_t *a, 397 unw_word_t *addr, 398 unsigned char encoding, 399 const unw_proc_info_t *pi, 400 unw_word_t *valp, void *arg); 401 extern int dwarf_step (struct dwarf_cursor *c); 402 403 #if 0 // Keep for now, used to find .debug_frame. 404 extern int dwarf_as_find_debug_frame (int found, unw_dyn_info_t *di_debug, 405 unw_word_t ip, 406 unw_word_t segbase, 407 const char* obj_name, 408 unw_word_t start, unw_word_t end, 409 unw_addr_space_t as); 410 #endif 411 412 extern int dwarf_as_find_unwind_table (struct as_elf_dyn_info *edi, 413 unw_addr_space_t as, 414 const char *path, 415 unw_word_t segbase, unw_word_t mapoff, 416 unw_word_t ip); 417 418 #endif /* dwarf_h */ 419