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 <libunwind.h> 30 #include <stdatomic.h> 31 32 struct dwarf_cursor; /* forward-declaration */ 33 struct elf_dyn_info; 34 35 #include "dwarf-config.h" 36 37 #ifdef HAVE_CONFIG_H 38 # include "config.h" 39 #endif 40 41 #ifndef UNW_REMOTE_ONLY 42 #if defined(HAVE_LINK_H) 43 #include <link.h> 44 #elif defined(HAVE_SYS_LINK_H) 45 #include <sys/link.h> 46 #else 47 #error Could not find <link.h> 48 #endif 49 #if defined(__ANDROID__) && defined(__arm__) && __ANDROID_API__ < 21 50 int dl_iterate_phdr(int (*)(struct dl_phdr_info *, size_t, void *), void *); 51 #endif 52 #endif 53 54 #include <pthread.h> 55 56 /* DWARF expression opcodes. */ 57 58 typedef enum 59 { 60 DW_OP_addr = 0x03, 61 DW_OP_deref = 0x06, 62 DW_OP_const1u = 0x08, 63 DW_OP_const1s = 0x09, 64 DW_OP_const2u = 0x0a, 65 DW_OP_const2s = 0x0b, 66 DW_OP_const4u = 0x0c, 67 DW_OP_const4s = 0x0d, 68 DW_OP_const8u = 0x0e, 69 DW_OP_const8s = 0x0f, 70 DW_OP_constu = 0x10, 71 DW_OP_consts = 0x11, 72 DW_OP_dup = 0x12, 73 DW_OP_drop = 0x13, 74 DW_OP_over = 0x14, 75 DW_OP_pick = 0x15, 76 DW_OP_swap = 0x16, 77 DW_OP_rot = 0x17, 78 DW_OP_xderef = 0x18, 79 DW_OP_abs = 0x19, 80 DW_OP_and = 0x1a, 81 DW_OP_div = 0x1b, 82 DW_OP_minus = 0x1c, 83 DW_OP_mod = 0x1d, 84 DW_OP_mul = 0x1e, 85 DW_OP_neg = 0x1f, 86 DW_OP_not = 0x20, 87 DW_OP_or = 0x21, 88 DW_OP_plus = 0x22, 89 DW_OP_plus_uconst = 0x23, 90 DW_OP_shl = 0x24, 91 DW_OP_shr = 0x25, 92 DW_OP_shra = 0x26, 93 DW_OP_xor = 0x27, 94 DW_OP_skip = 0x2f, 95 DW_OP_bra = 0x28, 96 DW_OP_eq = 0x29, 97 DW_OP_ge = 0x2a, 98 DW_OP_gt = 0x2b, 99 DW_OP_le = 0x2c, 100 DW_OP_lt = 0x2d, 101 DW_OP_ne = 0x2e, 102 DW_OP_lit0 = 0x30, 103 DW_OP_lit1, DW_OP_lit2, DW_OP_lit3, DW_OP_lit4, DW_OP_lit5, 104 DW_OP_lit6, DW_OP_lit7, DW_OP_lit8, DW_OP_lit9, DW_OP_lit10, 105 DW_OP_lit11, DW_OP_lit12, DW_OP_lit13, DW_OP_lit14, DW_OP_lit15, 106 DW_OP_lit16, DW_OP_lit17, DW_OP_lit18, DW_OP_lit19, DW_OP_lit20, 107 DW_OP_lit21, DW_OP_lit22, DW_OP_lit23, DW_OP_lit24, DW_OP_lit25, 108 DW_OP_lit26, DW_OP_lit27, DW_OP_lit28, DW_OP_lit29, DW_OP_lit30, 109 DW_OP_lit31, 110 DW_OP_reg0 = 0x50, 111 DW_OP_reg1, DW_OP_reg2, DW_OP_reg3, DW_OP_reg4, DW_OP_reg5, 112 DW_OP_reg6, DW_OP_reg7, DW_OP_reg8, DW_OP_reg9, DW_OP_reg10, 113 DW_OP_reg11, DW_OP_reg12, DW_OP_reg13, DW_OP_reg14, DW_OP_reg15, 114 DW_OP_reg16, DW_OP_reg17, DW_OP_reg18, DW_OP_reg19, DW_OP_reg20, 115 DW_OP_reg21, DW_OP_reg22, DW_OP_reg23, DW_OP_reg24, DW_OP_reg25, 116 DW_OP_reg26, DW_OP_reg27, DW_OP_reg28, DW_OP_reg29, DW_OP_reg30, 117 DW_OP_reg31, 118 DW_OP_breg0 = 0x70, 119 DW_OP_breg1, DW_OP_breg2, DW_OP_breg3, DW_OP_breg4, DW_OP_breg5, 120 DW_OP_breg6, DW_OP_breg7, DW_OP_breg8, DW_OP_breg9, DW_OP_breg10, 121 DW_OP_breg11, DW_OP_breg12, DW_OP_breg13, DW_OP_breg14, DW_OP_breg15, 122 DW_OP_breg16, DW_OP_breg17, DW_OP_breg18, DW_OP_breg19, DW_OP_breg20, 123 DW_OP_breg21, DW_OP_breg22, DW_OP_breg23, DW_OP_breg24, DW_OP_breg25, 124 DW_OP_breg26, DW_OP_breg27, DW_OP_breg28, DW_OP_breg29, DW_OP_breg30, 125 DW_OP_breg31, 126 DW_OP_regx = 0x90, 127 DW_OP_fbreg = 0x91, 128 DW_OP_bregx = 0x92, 129 DW_OP_piece = 0x93, 130 DW_OP_deref_size = 0x94, 131 DW_OP_xderef_size = 0x95, 132 DW_OP_nop = 0x96, 133 DW_OP_push_object_address = 0x97, 134 DW_OP_call2 = 0x98, 135 DW_OP_call4 = 0x99, 136 DW_OP_call_ref = 0x9a, 137 DW_OP_lo_user = 0xe0, 138 DW_OP_hi_user = 0xff 139 } 140 dwarf_expr_op_t; 141 142 #define DWARF_CIE_VERSION 3 143 #define DWARF_CIE_VERSION_MAX 4 144 145 #define DWARF_CFA_OPCODE_MASK 0xc0 146 #define DWARF_CFA_OPERAND_MASK 0x3f 147 148 typedef enum 149 { 150 DW_CFA_advance_loc = 0x40, 151 DW_CFA_offset = 0x80, 152 DW_CFA_restore = 0xc0, 153 DW_CFA_nop = 0x00, 154 DW_CFA_set_loc = 0x01, 155 DW_CFA_advance_loc1 = 0x02, 156 DW_CFA_advance_loc2 = 0x03, 157 DW_CFA_advance_loc4 = 0x04, 158 DW_CFA_offset_extended = 0x05, 159 DW_CFA_restore_extended = 0x06, 160 DW_CFA_undefined = 0x07, 161 DW_CFA_same_value = 0x08, 162 DW_CFA_register = 0x09, 163 DW_CFA_remember_state = 0x0a, 164 DW_CFA_restore_state = 0x0b, 165 DW_CFA_def_cfa = 0x0c, 166 DW_CFA_def_cfa_register = 0x0d, 167 DW_CFA_def_cfa_offset = 0x0e, 168 DW_CFA_def_cfa_expression = 0x0f, 169 DW_CFA_expression = 0x10, 170 DW_CFA_offset_extended_sf = 0x11, 171 DW_CFA_def_cfa_sf = 0x12, 172 DW_CFA_def_cfa_offset_sf = 0x13, 173 DW_CFA_val_expression = 0x16, 174 DW_CFA_lo_user = 0x1c, 175 DW_CFA_MIPS_advance_loc8 = 0x1d, 176 DW_CFA_GNU_window_save = 0x2d, 177 DW_CFA_GNU_args_size = 0x2e, 178 DW_CFA_GNU_negative_offset_extended = 0x2f, 179 DW_CFA_hi_user = 0x3c 180 } 181 dwarf_cfa_t; 182 183 /* DWARF Pointer-Encoding (PEs). 184 185 Pointer-Encodings were invented for the GCC exception-handling 186 support for C++, but they represent a rather generic way of 187 describing the format in which an address/pointer is stored and 188 hence we include the definitions here, in the main dwarf.h file. 189 The Pointer-Encoding format is partially documented in Linux Base 190 Spec v1.3 (http://www.linuxbase.org/spec/). The rest is reverse 191 engineered from GCC. 192 193 */ 194 #define DW_EH_PE_FORMAT_MASK 0x0f /* format of the encoded value */ 195 #define DW_EH_PE_APPL_MASK 0x70 /* how the value is to be applied */ 196 /* Flag bit. If set, the resulting pointer is the address of the word 197 that contains the final address. */ 198 #define DW_EH_PE_indirect 0x80 199 200 /* Pointer-encoding formats: */ 201 #define DW_EH_PE_omit 0xff 202 #define DW_EH_PE_ptr 0x00 /* pointer-sized unsigned value */ 203 #define DW_EH_PE_uleb128 0x01 /* unsigned LE base-128 value */ 204 #define DW_EH_PE_udata2 0x02 /* unsigned 16-bit value */ 205 #define DW_EH_PE_udata4 0x03 /* unsigned 32-bit value */ 206 #define DW_EH_PE_udata8 0x04 /* unsigned 64-bit value */ 207 #define DW_EH_PE_sleb128 0x09 /* signed LE base-128 value */ 208 #define DW_EH_PE_sdata2 0x0a /* signed 16-bit value */ 209 #define DW_EH_PE_sdata4 0x0b /* signed 32-bit value */ 210 #define DW_EH_PE_sdata8 0x0c /* signed 64-bit value */ 211 212 /* Pointer-encoding application: */ 213 #define DW_EH_PE_absptr 0x00 /* absolute value */ 214 #define DW_EH_PE_pcrel 0x10 /* rel. to addr. of encoded value */ 215 #define DW_EH_PE_textrel 0x20 /* text-relative (GCC-specific???) */ 216 #define DW_EH_PE_datarel 0x30 /* data-relative */ 217 /* The following are not documented by LSB v1.3, yet they are used by 218 GCC, presumably they aren't documented by LSB since they aren't 219 used on Linux: */ 220 #define DW_EH_PE_funcrel 0x40 /* start-of-procedure-relative */ 221 #define DW_EH_PE_aligned 0x50 /* aligned pointer */ 222 223 extern struct mempool dwarf_reg_state_pool; 224 extern struct mempool dwarf_cie_info_pool; 225 226 typedef enum 227 { 228 DWARF_WHERE_UNDEF, /* register isn't saved at all */ 229 DWARF_WHERE_SAME, /* register has same value as in prev. frame */ 230 DWARF_WHERE_CFAREL, /* register saved at CFA-relative address */ 231 DWARF_WHERE_REG, /* register saved in another register */ 232 DWARF_WHERE_EXPR, /* register saved */ 233 DWARF_WHERE_VAL_EXPR, /* register has computed value */ 234 } 235 dwarf_where_t; 236 237 /* For uniformity, we'd like to treat the CFA save-location like any 238 other register save-location, but this doesn't quite work, because 239 the CFA can be expressed as a (REGISTER,OFFSET) pair. To handle 240 this, we use two dwarf_save_loc structures to describe the CFA. 241 The first one (CFA_REG_COLUMN), tells us where the CFA is saved. 242 In the case of DWARF_WHERE_EXPR, the CFA is defined by a DWARF 243 location expression whose address is given by member "val". In the 244 case of DWARF_WHERE_REG, member "val" gives the number of the 245 base-register and the "val" member of DWARF_CFA_OFF_COLUMN gives 246 the offset value. */ 247 #define DWARF_CFA_REG_COLUMN DWARF_NUM_PRESERVED_REGS 248 #define DWARF_CFA_OFF_COLUMN (DWARF_NUM_PRESERVED_REGS + 1) 249 250 typedef struct dwarf_reg_only_state 251 { 252 char where[DWARF_NUM_PRESERVED_REGS + 2]; /* how is the register saved? */ 253 unw_word_t val[DWARF_NUM_PRESERVED_REGS + 2]; /* where it's saved */ 254 } 255 dwarf_reg_only_state_t; 256 257 typedef struct dwarf_reg_state 258 { 259 unw_word_t ret_addr_column; /* which column in rule table represents return address */ 260 dwarf_reg_only_state_t reg; 261 } 262 dwarf_reg_state_t; 263 264 typedef struct dwarf_stackable_reg_state 265 { 266 struct dwarf_stackable_reg_state *next; /* for rs_stack */ 267 dwarf_reg_state_t state; 268 } 269 dwarf_stackable_reg_state_t; 270 271 typedef struct dwarf_reg_cache_entry 272 { 273 unw_word_t ip; /* ip this rs is for */ 274 unsigned short coll_chain; /* used for hash collisions */ 275 unsigned short hint; /* hint for next rs to try (or -1) */ 276 unsigned short valid : 1; /* optional machine-dependent signal info */ 277 unsigned short signal_frame : 1; /* optional machine-dependent signal info */ 278 } 279 dwarf_reg_cache_entry_t; 280 281 typedef struct dwarf_cie_info 282 { 283 unw_word_t cie_instr_start; /* start addr. of CIE "initial_instructions" */ 284 unw_word_t cie_instr_end; /* end addr. of CIE "initial_instructions" */ 285 unw_word_t fde_instr_start; /* start addr. of FDE "instructions" */ 286 unw_word_t fde_instr_end; /* end addr. of FDE "instructions" */ 287 unw_word_t code_align; /* code-alignment factor */ 288 unw_word_t data_align; /* data-alignment factor */ 289 unw_word_t ret_addr_column; /* column of return-address register */ 290 unw_word_t handler; /* address of personality-routine */ 291 uint16_t abi; 292 uint16_t tag; 293 uint8_t fde_encoding; 294 uint8_t lsda_encoding; 295 unsigned int sized_augmentation : 1; 296 unsigned int have_abi_marker : 1; 297 unsigned int signal_frame : 1; 298 } 299 dwarf_cie_info_t; 300 301 typedef struct dwarf_state_record 302 { 303 unsigned char fde_encoding; 304 unw_word_t args_size; 305 306 dwarf_reg_state_t rs_initial; /* reg-state after CIE instructions */ 307 dwarf_reg_state_t rs_current; /* current reg-state */ 308 } 309 dwarf_state_record_t; 310 311 typedef struct dwarf_cursor 312 { 313 void *as_arg; /* argument to address-space callbacks */ 314 unw_addr_space_t as; /* reference to per-address-space info */ 315 316 unw_word_t cfa; /* canonical frame address; aka frame-/stack-pointer */ 317 unw_word_t ip; /* instruction pointer */ 318 unw_word_t args_size; /* size of arguments */ 319 unw_word_t eh_args[UNW_TDEP_NUM_EH_REGS]; 320 unsigned int eh_valid_mask; 321 322 dwarf_loc_t loc[DWARF_NUM_PRESERVED_REGS]; 323 324 unsigned int stash_frames :1; /* stash frames for fast lookup */ 325 unsigned int use_prev_instr :1; /* use previous (= call) or current (= signal) instruction? */ 326 unsigned int pi_valid :1; /* is proc_info valid? */ 327 unsigned int pi_is_dynamic :1; /* proc_info found via dynamic proc info? */ 328 unw_proc_info_t pi; /* info about current procedure */ 329 330 short hint; /* faster lookup of the rs cache */ 331 short prev_rs; 332 } 333 dwarf_cursor_t; 334 335 #define DWARF_DEFAULT_LOG_UNW_CACHE_SIZE 7 336 #define DWARF_DEFAULT_UNW_CACHE_SIZE (1 << DWARF_DEFAULT_LOG_UNW_CACHE_SIZE) 337 338 #define DWARF_DEFAULT_LOG_UNW_HASH_SIZE (DWARF_DEFAULT_LOG_UNW_CACHE_SIZE + 1) 339 #define DWARF_DEFAULT_UNW_HASH_SIZE (1 << DWARF_DEFAULT_LOG_UNW_HASH_SIZE) 340 341 typedef unsigned char unw_hash_index_t; 342 343 struct dwarf_rs_cache 344 { 345 pthread_mutex_t lock; 346 unsigned short rr_head; /* index of least-recently allocated rs */ 347 348 unsigned short log_size; 349 unsigned short prev_log_size; 350 351 /* hash table that maps instruction pointer to rs index: */ 352 unsigned short *hash; 353 354 _Atomic uint32_t generation; /* generation number */ 355 356 /* rs cache: */ 357 dwarf_reg_state_t *buckets; 358 dwarf_reg_cache_entry_t *links; 359 360 /* default memory, loaded in BSS segment */ 361 unsigned short default_hash[DWARF_DEFAULT_UNW_HASH_SIZE]; 362 dwarf_reg_state_t default_buckets[DWARF_DEFAULT_UNW_CACHE_SIZE]; 363 dwarf_reg_cache_entry_t default_links[DWARF_DEFAULT_UNW_CACHE_SIZE]; 364 }; 365 366 /* A list of descriptors for loaded .debug_frame sections. */ 367 368 struct unw_debug_frame_list 369 { 370 /* The start (inclusive) and end (exclusive) of the described region. */ 371 unw_word_t start; 372 unw_word_t end; 373 /* ELF load offset */ 374 unw_word_t load_offset; 375 /* The debug frame itself. */ 376 char *debug_frame; 377 size_t debug_frame_size; 378 /* Index (for binary search). */ 379 struct table_entry *index; 380 size_t index_size; 381 /* Pointer to next descriptor. */ 382 struct unw_debug_frame_list *next; 383 }; 384 385 /* Convenience macros: */ 386 #define dwarf_init UNW_ARCH_OBJ (dwarf_init) 387 #define dwarf_callback UNW_OBJ (dwarf_callback) 388 #define dwarf_find_proc_info UNW_OBJ (dwarf_find_proc_info) 389 #define dwarf_find_debug_frame UNW_OBJ (dwarf_find_debug_frame) 390 #define dwarf_search_unwind_table UNW_OBJ (dwarf_search_unwind_table) 391 #define dwarf_find_unwind_table UNW_OBJ (dwarf_find_unwind_table) 392 #define dwarf_put_unwind_info UNW_OBJ (dwarf_put_unwind_info) 393 #define dwarf_put_unwind_info UNW_OBJ (dwarf_put_unwind_info) 394 #define dwarf_eval_expr UNW_OBJ (dwarf_eval_expr) 395 #define dwarf_stack_aligned UNW_OBJ (dwarf_stack_aligned) 396 #define dwarf_extract_proc_info_from_fde \ 397 UNW_OBJ (dwarf_extract_proc_info_from_fde) 398 #define dwarf_find_save_locs UNW_OBJ (dwarf_find_save_locs) 399 #define dwarf_make_proc_info UNW_OBJ (dwarf_make_proc_info) 400 #define dwarf_apply_reg_state UNW_OBJ (dwarf_apply_reg_state) 401 #define dwarf_reg_states_iterate UNW_OBJ (dwarf_reg_states_iterate) 402 #define dwarf_read_encoded_pointer UNW_OBJ (dwarf_read_encoded_pointer) 403 #define dwarf_step UNW_OBJ (dwarf_step) 404 #define dwarf_flush_rs_cache UNW_OBJ (dwarf_flush_rs_cache) 405 406 extern int dwarf_init (void); 407 #ifndef UNW_REMOTE_ONLY 408 extern int dwarf_callback (struct dl_phdr_info *info, size_t size, void *ptr); 409 extern int dwarf_find_proc_info (unw_addr_space_t as, unw_word_t ip, 410 unw_proc_info_t *pi, 411 int need_unwind_info, void *arg); 412 #endif /* !UNW_REMOTE_ONLY */ 413 extern int dwarf_find_debug_frame (int found, unw_dyn_info_t *di_debug, 414 unw_word_t ip, unw_word_t segbase, 415 const char* obj_name, unw_word_t start, 416 unw_word_t end); 417 extern int dwarf_search_unwind_table (unw_addr_space_t as, 418 unw_word_t ip, 419 unw_dyn_info_t *di, 420 unw_proc_info_t *pi, 421 int need_unwind_info, void *arg); 422 423 extern int dwarf_find_unwind_table (struct elf_dyn_info *edi, unw_addr_space_t as, 424 char *path, unw_word_t segbase, unw_word_t mapoff, 425 unw_word_t ip); 426 extern void dwarf_put_unwind_info (unw_addr_space_t as, 427 unw_proc_info_t *pi, void *arg); 428 extern int dwarf_eval_expr (struct dwarf_cursor *c, unw_word_t stack_val, unw_word_t *addr, 429 unw_word_t len, unw_word_t *valp, 430 int *is_register); 431 extern int 432 dwarf_stack_aligned(struct dwarf_cursor *c, unw_word_t cfa_addr, 433 unw_word_t rbp_addr, unw_word_t *offset); 434 435 extern int dwarf_extract_proc_info_from_fde (unw_addr_space_t as, 436 unw_accessors_t *a, 437 unw_word_t *fde_addr, 438 unw_proc_info_t *pi, 439 unw_word_t base, 440 int need_unwind_info, 441 int is_debug_frame, 442 void *arg); 443 extern int dwarf_find_save_locs (struct dwarf_cursor *c); 444 extern int dwarf_make_proc_info (struct dwarf_cursor *c); 445 extern int dwarf_apply_reg_state (struct dwarf_cursor *c, struct dwarf_reg_state *rs); 446 extern int dwarf_reg_states_iterate (struct dwarf_cursor *c, unw_reg_states_callback cb, void *token); 447 extern int dwarf_read_encoded_pointer (unw_addr_space_t as, 448 unw_accessors_t *a, 449 unw_word_t *addr, 450 unsigned char encoding, 451 const unw_proc_info_t *pi, 452 unw_word_t *valp, void *arg); 453 extern int dwarf_step (struct dwarf_cursor *c); 454 extern int dwarf_flush_rs_cache (struct dwarf_rs_cache *cache); 455 456 #endif /* dwarf_h */ 457