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>
5 This file is part of libunwind.
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:
15 The above copyright notice and this permission notice shall be
16 included in all copies or substantial portions of the Software.
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. */
29 #include <libunwind.h>
31 struct dwarf_cursor; /* forward-declaration */
34 #include "dwarf-config.h"
35 #ifndef UNW_REMOTE_ONLY
40 /* DWARF expression opcodes. */
73 DW_OP_plus_uconst = 0x23,
87 DW_OP_lit1, DW_OP_lit2, DW_OP_lit3, DW_OP_lit4, DW_OP_lit5,
88 DW_OP_lit6, DW_OP_lit7, DW_OP_lit8, DW_OP_lit9, DW_OP_lit10,
89 DW_OP_lit11, DW_OP_lit12, DW_OP_lit13, DW_OP_lit14, DW_OP_lit15,
90 DW_OP_lit16, DW_OP_lit17, DW_OP_lit18, DW_OP_lit19, DW_OP_lit20,
91 DW_OP_lit21, DW_OP_lit22, DW_OP_lit23, DW_OP_lit24, DW_OP_lit25,
92 DW_OP_lit26, DW_OP_lit27, DW_OP_lit28, DW_OP_lit29, DW_OP_lit30,
95 DW_OP_reg1, DW_OP_reg2, DW_OP_reg3, DW_OP_reg4, DW_OP_reg5,
96 DW_OP_reg6, DW_OP_reg7, DW_OP_reg8, DW_OP_reg9, DW_OP_reg10,
97 DW_OP_reg11, DW_OP_reg12, DW_OP_reg13, DW_OP_reg14, DW_OP_reg15,
98 DW_OP_reg16, DW_OP_reg17, DW_OP_reg18, DW_OP_reg19, DW_OP_reg20,
99 DW_OP_reg21, DW_OP_reg22, DW_OP_reg23, DW_OP_reg24, DW_OP_reg25,
100 DW_OP_reg26, DW_OP_reg27, DW_OP_reg28, DW_OP_reg29, DW_OP_reg30,
103 DW_OP_breg1, DW_OP_breg2, DW_OP_breg3, DW_OP_breg4, DW_OP_breg5,
104 DW_OP_breg6, DW_OP_breg7, DW_OP_breg8, DW_OP_breg9, DW_OP_breg10,
105 DW_OP_breg11, DW_OP_breg12, DW_OP_breg13, DW_OP_breg14, DW_OP_breg15,
106 DW_OP_breg16, DW_OP_breg17, DW_OP_breg18, DW_OP_breg19, DW_OP_breg20,
107 DW_OP_breg21, DW_OP_breg22, DW_OP_breg23, DW_OP_breg24, DW_OP_breg25,
108 DW_OP_breg26, DW_OP_breg27, DW_OP_breg28, DW_OP_breg29, DW_OP_breg30,
114 DW_OP_deref_size = 0x94,
115 DW_OP_xderef_size = 0x95,
117 DW_OP_push_object_address = 0x97,
120 DW_OP_call_ref = 0x9a,
121 DW_OP_lo_user = 0xe0,
126 #define DWARF_CIE_VERSION 3 /* GCC emits version 1??? */
128 #define DWARF_CFA_OPCODE_MASK 0xc0
129 #define DWARF_CFA_OPERAND_MASK 0x3f
133 DW_CFA_advance_loc = 0x40,
134 DW_CFA_offset = 0x80,
135 DW_CFA_restore = 0xc0,
137 DW_CFA_set_loc = 0x01,
138 DW_CFA_advance_loc1 = 0x02,
139 DW_CFA_advance_loc2 = 0x03,
140 DW_CFA_advance_loc4 = 0x04,
141 DW_CFA_offset_extended = 0x05,
142 DW_CFA_restore_extended = 0x06,
143 DW_CFA_undefined = 0x07,
144 DW_CFA_same_value = 0x08,
145 DW_CFA_register = 0x09,
146 DW_CFA_remember_state = 0x0a,
147 DW_CFA_restore_state = 0x0b,
148 DW_CFA_def_cfa = 0x0c,
149 DW_CFA_def_cfa_register = 0x0d,
150 DW_CFA_def_cfa_offset = 0x0e,
151 DW_CFA_def_cfa_expression = 0x0f,
152 DW_CFA_expression = 0x10,
153 DW_CFA_offset_extended_sf = 0x11,
154 DW_CFA_def_cfa_sf = 0x12,
155 DW_CFA_def_cfa_offset_sf = 0x13,
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
165 /* DWARF Pointer-Encoding (PEs).
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
176 #define DW_EH_PE_FORMAT_MASK 0x0f /* format of the encoded value */
177 #define DW_EH_PE_APPL_MASK 0x70 /* how the value is to be applied */
178 /* Flag bit. If set, the resulting pointer is the address of the word
179 that contains the final address. */
180 #define DW_EH_PE_indirect 0x80
182 /* Pointer-encoding formats: */
183 #define DW_EH_PE_omit 0xff
184 #define DW_EH_PE_ptr 0x00 /* pointer-sized unsigned value */
185 #define DW_EH_PE_uleb128 0x01 /* unsigned LE base-128 value */
186 #define DW_EH_PE_udata2 0x02 /* unsigned 16-bit value */
187 #define DW_EH_PE_udata4 0x03 /* unsigned 32-bit value */
188 #define DW_EH_PE_udata8 0x04 /* unsigned 64-bit value */
189 #define DW_EH_PE_sleb128 0x09 /* signed LE base-128 value */
190 #define DW_EH_PE_sdata2 0x0a /* signed 16-bit value */
191 #define DW_EH_PE_sdata4 0x0b /* signed 32-bit value */
192 #define DW_EH_PE_sdata8 0x0c /* signed 64-bit value */
194 /* Pointer-encoding application: */
195 #define DW_EH_PE_absptr 0x00 /* absolute value */
196 #define DW_EH_PE_pcrel 0x10 /* rel. to addr. of encoded value */
197 #define DW_EH_PE_textrel 0x20 /* text-relative (GCC-specific???) */
198 #define DW_EH_PE_datarel 0x30 /* data-relative */
199 /* The following are not documented by LSB v1.3, yet they are used by
200 GCC, presumably they aren't documented by LSB since they aren't
202 #define DW_EH_PE_funcrel 0x40 /* start-of-procedure-relative */
203 #define DW_EH_PE_aligned 0x50 /* aligned pointer */
205 extern struct mempool dwarf_reg_state_pool;
206 extern struct mempool dwarf_cie_info_pool;
210 DWARF_WHERE_UNDEF, /* register isn't saved at all */
211 DWARF_WHERE_SAME, /* register has same value as in prev. frame */
212 DWARF_WHERE_CFAREL, /* register saved at CFA-relative address */
213 DWARF_WHERE_REG, /* register saved in another register */
214 DWARF_WHERE_EXPR, /* register saved */
220 dwarf_where_t where; /* how is the register saved? */
221 unw_word_t val; /* where it's saved */
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
235 #define DWARF_CFA_REG_COLUMN DWARF_NUM_PRESERVED_REGS
236 #define DWARF_CFA_OFF_COLUMN (DWARF_NUM_PRESERVED_REGS + 1)
238 typedef struct dwarf_reg_state
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 */
252 typedef struct dwarf_cie_info
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 */
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;
272 typedef struct dwarf_state_record
274 unsigned char fde_encoding;
275 unw_word_t args_size;
277 dwarf_reg_state_t rs_initial; /* reg-state after CIE instructions */
278 dwarf_reg_state_t rs_current; /* current reg-state */
280 dwarf_state_record_t;
282 typedef struct dwarf_cursor
284 void *as_arg; /* argument to address-space callbacks */
285 unw_addr_space_t as; /* reference to per-address-space info */
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;
294 dwarf_loc_t loc[DWARF_NUM_PRESERVED_REGS];
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 */
302 short hint; /* faster lookup of the rs cache */
307 #define DWARF_LOG_UNW_CACHE_SIZE 7
308 #define DWARF_UNW_CACHE_SIZE (1 << DWARF_LOG_UNW_CACHE_SIZE)
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)
313 typedef unsigned char unw_hash_index_t;
315 struct dwarf_rs_cache
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 */
321 /* hash table that maps instruction pointer to rs index: */
322 unsigned short hash[DWARF_UNW_HASH_SIZE];
324 uint32_t generation; /* generation number */
327 dwarf_reg_state_t buckets[DWARF_UNW_CACHE_SIZE];
330 /* A list of descriptors for loaded .debug_frame sections. */
332 struct unw_debug_frame_list
334 /* The start (inclusive) and end (exclusive) of the described region. */
337 /* The debug frame itself. */
339 size_t debug_frame_size;
340 /* Index (for binary search). */
341 struct table_entry *index;
343 /* Pointer to next descriptor. */
344 struct unw_debug_frame_list *next;
347 struct dwarf_callback_data
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;
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 */
359 /* Convenience macros: */
360 #define dwarf_init UNW_ARCH_OBJ (dwarf_init)
361 #define dwarf_callback UNW_OBJ (dwarf_callback)
362 #define dwarf_find_proc_info UNW_OBJ (dwarf_find_proc_info)
363 #define dwarf_find_debug_frame UNW_OBJ (dwarf_find_debug_frame)
364 #define dwarf_search_unwind_table UNW_OBJ (dwarf_search_unwind_table)
365 #define dwarf_find_unwind_table UNW_OBJ (dwarf_find_unwind_table)
366 #define dwarf_put_unwind_info UNW_OBJ (dwarf_put_unwind_info)
367 #define dwarf_put_unwind_info UNW_OBJ (dwarf_put_unwind_info)
368 #define dwarf_eval_expr UNW_OBJ (dwarf_eval_expr)
369 #define dwarf_extract_proc_info_from_fde \
370 UNW_OBJ (dwarf_extract_proc_info_from_fde)
371 #define dwarf_find_save_locs UNW_OBJ (dwarf_find_save_locs)
372 #define dwarf_create_state_record UNW_OBJ (dwarf_create_state_record)
373 #define dwarf_make_proc_info UNW_OBJ (dwarf_make_proc_info)
374 #define dwarf_read_encoded_pointer UNW_OBJ (dwarf_read_encoded_pointer)
375 #define dwarf_step UNW_OBJ (dwarf_step)
377 extern int dwarf_init (void);
378 #ifndef UNW_REMOTE_ONLY
379 extern int dwarf_callback (struct dl_phdr_info *info, size_t size, void *ptr);
380 extern int dwarf_find_proc_info (unw_addr_space_t as, unw_word_t ip,
382 int need_unwind_info, void *arg);
383 #endif /* !UNW_REMOTE_ONLY */
384 extern int dwarf_find_debug_frame (int found, unw_dyn_info_t *di_debug,
385 unw_word_t ip, unw_word_t segbase,
386 const char* obj_name, unw_word_t start,
388 extern int dwarf_search_unwind_table (unw_addr_space_t as,
392 int need_unwind_info, void *arg);
393 extern int dwarf_find_unwind_table (struct elf_dyn_info *edi, unw_addr_space_t as,
394 char *path, unw_word_t segbase, unw_word_t mapoff,
396 extern void dwarf_put_unwind_info (unw_addr_space_t as,
397 unw_proc_info_t *pi, void *arg);
398 extern int dwarf_eval_expr (struct dwarf_cursor *c, unw_word_t *addr,
399 unw_word_t len, unw_word_t *valp,
401 extern int dwarf_extract_proc_info_from_fde (unw_addr_space_t as,
403 unw_word_t *fde_addr,
405 int need_unwind_info,
408 extern int dwarf_find_save_locs (struct dwarf_cursor *c);
409 extern int dwarf_create_state_record (struct dwarf_cursor *c,
410 dwarf_state_record_t *sr);
411 extern int dwarf_make_proc_info (struct dwarf_cursor *c);
412 extern int dwarf_read_encoded_pointer (unw_addr_space_t as,
415 unsigned char encoding,
416 const unw_proc_info_t *pi,
417 unw_word_t *valp, void *arg);
418 extern int dwarf_step (struct dwarf_cursor *c);