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- /* libunwind - a platform-independent unwind library
- Copyright (c) 2003, 2005 Hewlett-Packard Development Company, L.P.
- Contributed by David Mosberger-Tang <davidm@hpl.hp.com>
- This file is part of libunwind.
- Permission is hereby granted, free of charge, to any person obtaining
- a copy of this software and associated documentation files (the
- "Software"), to deal in the Software without restriction, including
- without limitation the rights to use, copy, modify, merge, publish,
- distribute, sublicense, and/or sell copies of the Software, and to
- permit persons to whom the Software is furnished to do so, subject to
- the following conditions:
- The above copyright notice and this permission notice shall be
- included in all copies or substantial portions of the Software.
- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
- EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
- MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
- NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
- LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
- OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
- WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
- #include <stddef.h>
- #include "dwarf_i.h"
- #include "libunwind_i.h"
- #define alloc_reg_state() (mempool_alloc (&dwarf_reg_state_pool))
- #define free_reg_state(rs) (mempool_free (&dwarf_reg_state_pool, rs))
- static inline int
- read_regnum (unw_addr_space_t as, unw_accessors_t *a, unw_word_t *addr,
- unw_word_t *valp, void *arg)
- {
- int ret;
- if ((ret = dwarf_read_uleb128 (as, a, addr, valp, arg)) < 0)
- return ret;
- if (*valp >= DWARF_NUM_PRESERVED_REGS)
- {
- Debug (1, "Invalid register number %u\n", (unsigned int) *valp);
- return -UNW_EBADREG;
- }
- return 0;
- }
- static inline void
- set_reg (dwarf_state_record_t *sr, unw_word_t regnum, dwarf_where_t where,
- unw_word_t val)
- {
- sr->rs_current.reg[regnum].where = where;
- sr->rs_current.reg[regnum].val = val;
- }
- /* Run a CFI program to update the register state. */
- static int
- run_cfi_program (struct dwarf_cursor *c, dwarf_state_record_t *sr,
- unw_word_t ip, unw_word_t *addr, unw_word_t end_addr,
- struct dwarf_cie_info *dci)
- {
- unw_word_t curr_ip, operand = 0, regnum, val, len, fde_encoding;
- dwarf_reg_state_t *rs_stack = NULL, *new_rs, *old_rs;
- unw_addr_space_t as;
- unw_accessors_t *a;
- uint8_t u8, op;
- uint16_t u16;
- uint32_t u32;
- void *arg;
- int ret;
- as = c->as;
- arg = c->as_arg;
- if (c->pi.flags & UNW_PI_FLAG_DEBUG_FRAME)
- {
- /* .debug_frame CFI is stored in local address space. */
- as = unw_local_addr_space;
- arg = NULL;
- }
- a = unw_get_accessors (as);
- curr_ip = c->pi.start_ip;
- /* Process everything up to and including the current 'ip',
- including all the DW_CFA_advance_loc instructions. See
- 'c->use_prev_instr' use in 'fetch_proc_info' for details. */
- while (curr_ip <= ip && *addr < end_addr)
- {
- if ((ret = dwarf_readu8 (as, a, addr, &op, arg)) < 0)
- return ret;
- if (op & DWARF_CFA_OPCODE_MASK)
- {
- operand = op & DWARF_CFA_OPERAND_MASK;
- op &= ~DWARF_CFA_OPERAND_MASK;
- }
- switch ((dwarf_cfa_t) op)
- {
- case DW_CFA_advance_loc:
- curr_ip += operand * dci->code_align;
- Debug (15, "CFA_advance_loc to 0x%lx\n", (long) curr_ip);
- break;
- case DW_CFA_advance_loc1:
- if ((ret = dwarf_readu8 (as, a, addr, &u8, arg)) < 0)
- goto fail;
- curr_ip += u8 * dci->code_align;
- Debug (15, "CFA_advance_loc1 to 0x%lx\n", (long) curr_ip);
- break;
- case DW_CFA_advance_loc2:
- if ((ret = dwarf_readu16 (as, a, addr, &u16, arg)) < 0)
- goto fail;
- curr_ip += u16 * dci->code_align;
- Debug (15, "CFA_advance_loc2 to 0x%lx\n", (long) curr_ip);
- break;
- case DW_CFA_advance_loc4:
- if ((ret = dwarf_readu32 (as, a, addr, &u32, arg)) < 0)
- goto fail;
- curr_ip += u32 * dci->code_align;
- Debug (15, "CFA_advance_loc4 to 0x%lx\n", (long) curr_ip);
- break;
- case DW_CFA_MIPS_advance_loc8:
- #ifdef UNW_TARGET_MIPS
- {
- uint64_t u64;
- if ((ret = dwarf_readu64 (as, a, addr, &u64, arg)) < 0)
- goto fail;
- curr_ip += u64 * dci->code_align;
- Debug (15, "CFA_MIPS_advance_loc8\n");
- break;
- }
- #else
- Debug (1, "DW_CFA_MIPS_advance_loc8 on non-MIPS target\n");
- ret = -UNW_EINVAL;
- goto fail;
- #endif
- case DW_CFA_offset:
- regnum = operand;
- if (regnum >= DWARF_NUM_PRESERVED_REGS)
- {
- Debug (1, "Invalid register number %u in DW_cfa_OFFSET\n",
- (unsigned int) regnum);
- ret = -UNW_EBADREG;
- goto fail;
- }
- if ((ret = dwarf_read_uleb128 (as, a, addr, &val, arg)) < 0)
- goto fail;
- set_reg (sr, regnum, DWARF_WHERE_CFAREL, val * dci->data_align);
- Debug (15, "CFA_offset r%lu at cfa+0x%lx\n",
- (long) regnum, (long) (val * dci->data_align));
- break;
- case DW_CFA_offset_extended:
- if (((ret = read_regnum (as, a, addr, ®num, arg)) < 0)
- || ((ret = dwarf_read_uleb128 (as, a, addr, &val, arg)) < 0))
- goto fail;
- set_reg (sr, regnum, DWARF_WHERE_CFAREL, val * dci->data_align);
- Debug (15, "CFA_offset_extended r%lu at cf+0x%lx\n",
- (long) regnum, (long) (val * dci->data_align));
- break;
- case DW_CFA_offset_extended_sf:
- if (((ret = read_regnum (as, a, addr, ®num, arg)) < 0)
- || ((ret = dwarf_read_sleb128 (as, a, addr, &val, arg)) < 0))
- goto fail;
- set_reg (sr, regnum, DWARF_WHERE_CFAREL, val * dci->data_align);
- Debug (15, "CFA_offset_extended_sf r%lu at cf+0x%lx\n",
- (long) regnum, (long) (val * dci->data_align));
- break;
- case DW_CFA_restore:
- regnum = operand;
- if (regnum >= DWARF_NUM_PRESERVED_REGS)
- {
- Debug (1, "Invalid register number %u in DW_CFA_restore\n",
- (unsigned int) regnum);
- ret = -UNW_EINVAL;
- goto fail;
- }
- sr->rs_current.reg[regnum] = sr->rs_initial.reg[regnum];
- Debug (15, "CFA_restore r%lu\n", (long) regnum);
- break;
- case DW_CFA_restore_extended:
- if ((ret = dwarf_read_uleb128 (as, a, addr, ®num, arg)) < 0)
- goto fail;
- if (regnum >= DWARF_NUM_PRESERVED_REGS)
- {
- Debug (1, "Invalid register number %u in "
- "DW_CFA_restore_extended\n", (unsigned int) regnum);
- ret = -UNW_EINVAL;
- goto fail;
- }
- sr->rs_current.reg[regnum] = sr->rs_initial.reg[regnum];
- Debug (15, "CFA_restore_extended r%lu\n", (long) regnum);
- break;
- case DW_CFA_nop:
- break;
- case DW_CFA_set_loc:
- fde_encoding = dci->fde_encoding;
- if ((ret = dwarf_read_encoded_pointer (as, a, addr, fde_encoding,
- &c->pi, &curr_ip,
- arg)) < 0)
- goto fail;
- Debug (15, "CFA_set_loc to 0x%lx\n", (long) curr_ip);
- break;
- case DW_CFA_undefined:
- if ((ret = read_regnum (as, a, addr, ®num, arg)) < 0)
- goto fail;
- set_reg (sr, regnum, DWARF_WHERE_UNDEF, 0);
- Debug (15, "CFA_undefined r%lu\n", (long) regnum);
- break;
- case DW_CFA_same_value:
- if ((ret = read_regnum (as, a, addr, ®num, arg)) < 0)
- goto fail;
- set_reg (sr, regnum, DWARF_WHERE_SAME, 0);
- Debug (15, "CFA_same_value r%lu\n", (long) regnum);
- break;
- case DW_CFA_register:
- if (((ret = read_regnum (as, a, addr, ®num, arg)) < 0)
- || ((ret = dwarf_read_uleb128 (as, a, addr, &val, arg)) < 0))
- goto fail;
- set_reg (sr, regnum, DWARF_WHERE_REG, val);
- Debug (15, "CFA_register r%lu to r%lu\n", (long) regnum, (long) val);
- break;
- case DW_CFA_remember_state:
- new_rs = alloc_reg_state ();
- if (!new_rs)
- {
- Debug (1, "Out of memory in DW_CFA_remember_state\n");
- ret = -UNW_ENOMEM;
- goto fail;
- }
- memcpy (new_rs->reg, sr->rs_current.reg, sizeof (new_rs->reg));
- new_rs->next = rs_stack;
- rs_stack = new_rs;
- Debug (15, "CFA_remember_state\n");
- break;
- case DW_CFA_restore_state:
- if (!rs_stack)
- {
- Debug (1, "register-state stack underflow\n");
- ret = -UNW_EINVAL;
- goto fail;
- }
- memcpy (&sr->rs_current.reg, &rs_stack->reg, sizeof (rs_stack->reg));
- old_rs = rs_stack;
- rs_stack = rs_stack->next;
- free_reg_state (old_rs);
- Debug (15, "CFA_restore_state\n");
- break;
- case DW_CFA_def_cfa:
- if (((ret = read_regnum (as, a, addr, ®num, arg)) < 0)
- || ((ret = dwarf_read_uleb128 (as, a, addr, &val, arg)) < 0))
- goto fail;
- set_reg (sr, DWARF_CFA_REG_COLUMN, DWARF_WHERE_REG, regnum);
- set_reg (sr, DWARF_CFA_OFF_COLUMN, 0, val); /* NOT factored! */
- Debug (15, "CFA_def_cfa r%lu+0x%lx\n", (long) regnum, (long) val);
- break;
- case DW_CFA_def_cfa_sf:
- if (((ret = read_regnum (as, a, addr, ®num, arg)) < 0)
- || ((ret = dwarf_read_sleb128 (as, a, addr, &val, arg)) < 0))
- goto fail;
- set_reg (sr, DWARF_CFA_REG_COLUMN, DWARF_WHERE_REG, regnum);
- set_reg (sr, DWARF_CFA_OFF_COLUMN, 0,
- val * dci->data_align); /* factored! */
- Debug (15, "CFA_def_cfa_sf r%lu+0x%lx\n",
- (long) regnum, (long) (val * dci->data_align));
- break;
- case DW_CFA_def_cfa_register:
- if ((ret = read_regnum (as, a, addr, ®num, arg)) < 0)
- goto fail;
- set_reg (sr, DWARF_CFA_REG_COLUMN, DWARF_WHERE_REG, regnum);
- Debug (15, "CFA_def_cfa_register r%lu\n", (long) regnum);
- break;
- case DW_CFA_def_cfa_offset:
- if ((ret = dwarf_read_uleb128 (as, a, addr, &val, arg)) < 0)
- goto fail;
- set_reg (sr, DWARF_CFA_OFF_COLUMN, 0, val); /* NOT factored! */
- Debug (15, "CFA_def_cfa_offset 0x%lx\n", (long) val);
- break;
- case DW_CFA_def_cfa_offset_sf:
- if ((ret = dwarf_read_sleb128 (as, a, addr, &val, arg)) < 0)
- goto fail;
- set_reg (sr, DWARF_CFA_OFF_COLUMN, 0,
- val * dci->data_align); /* factored! */
- Debug (15, "CFA_def_cfa_offset_sf 0x%lx\n",
- (long) (val * dci->data_align));
- break;
- case DW_CFA_def_cfa_expression:
- /* Save the address of the DW_FORM_block for later evaluation. */
- set_reg (sr, DWARF_CFA_REG_COLUMN, DWARF_WHERE_EXPR, *addr);
- if ((ret = dwarf_read_uleb128 (as, a, addr, &len, arg)) < 0)
- goto fail;
- Debug (15, "CFA_def_cfa_expr @ 0x%lx [%lu bytes]\n",
- (long) *addr, (long) len);
- *addr += len;
- break;
- case DW_CFA_expression:
- if ((ret = read_regnum (as, a, addr, ®num, arg)) < 0)
- goto fail;
- /* Save the address of the DW_FORM_block for later evaluation. */
- set_reg (sr, regnum, DWARF_WHERE_EXPR, *addr);
- if ((ret = dwarf_read_uleb128 (as, a, addr, &len, arg)) < 0)
- goto fail;
- Debug (15, "CFA_expression r%lu @ 0x%lx [%lu bytes]\n",
- (long) regnum, (long) addr, (long) len);
- *addr += len;
- break;
- case DW_CFA_GNU_args_size:
- if ((ret = dwarf_read_uleb128 (as, a, addr, &val, arg)) < 0)
- goto fail;
- sr->args_size = val;
- Debug (15, "CFA_GNU_args_size %lu\n", (long) val);
- break;
- case DW_CFA_GNU_negative_offset_extended:
- /* A comment in GCC says that this is obsoleted by
- DW_CFA_offset_extended_sf, but that it's used by older
- PowerPC code. */
- if (((ret = read_regnum (as, a, addr, ®num, arg)) < 0)
- || ((ret = dwarf_read_uleb128 (as, a, addr, &val, arg)) < 0))
- goto fail;
- set_reg (sr, regnum, DWARF_WHERE_CFAREL, -(val * dci->data_align));
- Debug (15, "CFA_GNU_negative_offset_extended cfa+0x%lx\n",
- (long) -(val * dci->data_align));
- break;
- case DW_CFA_GNU_window_save:
- #ifdef UNW_TARGET_SPARC
- /* This is a special CFA to handle all 16 windowed registers
- on SPARC. */
- for (regnum = 16; regnum < 32; ++regnum)
- set_reg (sr, regnum, DWARF_WHERE_CFAREL,
- (regnum - 16) * sizeof (unw_word_t));
- Debug (15, "CFA_GNU_window_save\n");
- break;
- #else
- /* FALL THROUGH */
- #endif
- case DW_CFA_lo_user:
- case DW_CFA_hi_user:
- Debug (1, "Unexpected CFA opcode 0x%x\n", op);
- ret = -UNW_EINVAL;
- goto fail;
- }
- }
- ret = 0;
- fail:
- /* Free the register-state stack, if not empty already. */
- while (rs_stack)
- {
- old_rs = rs_stack;
- rs_stack = rs_stack->next;
- free_reg_state (old_rs);
- }
- return ret;
- }
- static int
- fetch_proc_info (struct dwarf_cursor *c, unw_word_t ip, int need_unwind_info)
- {
- int ret, dynamic = 1;
- /* The 'ip' can point either to the previous or next instruction
- depending on what type of frame we have: normal call or a place
- to resume execution (e.g. after signal frame).
- For a normal call frame we need to back up so we point within the
- call itself; this is important because a) the call might be the
- very last instruction of the function and the edge of the FDE,
- and b) so that run_cfi_program() runs locations up to the call
- but not more.
- For execution resume, we need to do the exact opposite and look
- up using the current 'ip' value. That is where execution will
- continue, and it's important we get this right, as 'ip' could be
- right at the function entry and hence FDE edge, or at instruction
- that manipulates CFA (push/pop). */
- if (c->use_prev_instr)
- --ip;
- if (c->pi_valid && !need_unwind_info)
- return 0;
- memset (&c->pi, 0, sizeof (c->pi));
- /* check dynamic info first --- it overrides everything else */
- ret = unwi_find_dynamic_proc_info (c->as, ip, &c->pi, need_unwind_info,
- c->as_arg);
- if (ret == -UNW_ENOINFO)
- {
- dynamic = 0;
- if ((ret = tdep_find_proc_info (c, ip, need_unwind_info)) < 0)
- return ret;
- }
- if (c->pi.format != UNW_INFO_FORMAT_DYNAMIC
- && c->pi.format != UNW_INFO_FORMAT_TABLE
- && c->pi.format != UNW_INFO_FORMAT_REMOTE_TABLE)
- return -UNW_ENOINFO;
- c->pi_valid = 1;
- c->pi_is_dynamic = dynamic;
- /* Let system/machine-dependent code determine frame-specific attributes. */
- if (ret >= 0)
- tdep_fetch_frame (c, ip, need_unwind_info);
- /* Update use_prev_instr for the next frame. */
- if (need_unwind_info)
- {
- assert(c->pi.unwind_info);
- struct dwarf_cie_info *dci = c->pi.unwind_info;
- c->use_prev_instr = ! dci->signal_frame;
- }
- return ret;
- }
- static int
- parse_dynamic (struct dwarf_cursor *c, unw_word_t ip, dwarf_state_record_t *sr)
- {
- Debug (1, "Not yet implemented\n");
- #if 0
- /* Don't forget to set the ret_addr_column! */
- c->ret_addr_column = XXX;
- #endif
- return -UNW_ENOINFO;
- }
- static inline void
- put_unwind_info (struct dwarf_cursor *c, unw_proc_info_t *pi)
- {
- if (!c->pi_valid)
- return;
- if (c->pi_is_dynamic)
- unwi_put_dynamic_unwind_info (c->as, pi, c->as_arg);
- else if (pi->unwind_info)
- {
- mempool_free (&dwarf_cie_info_pool, pi->unwind_info);
- pi->unwind_info = NULL;
- }
- }
- static inline int
- parse_fde (struct dwarf_cursor *c, unw_word_t ip, dwarf_state_record_t *sr)
- {
- struct dwarf_cie_info *dci;
- unw_word_t addr;
- int ret;
- dci = c->pi.unwind_info;
- c->ret_addr_column = dci->ret_addr_column;
- addr = dci->cie_instr_start;
- if ((ret = run_cfi_program (c, sr, ~(unw_word_t) 0, &addr,
- dci->cie_instr_end, dci)) < 0)
- return ret;
- memcpy (&sr->rs_initial, &sr->rs_current, sizeof (sr->rs_initial));
- addr = dci->fde_instr_start;
- if ((ret = run_cfi_program (c, sr, ip, &addr, dci->fde_instr_end, dci)) < 0)
- return ret;
- return 0;
- }
- static inline void
- flush_rs_cache (struct dwarf_rs_cache *cache)
- {
- int i;
- cache->lru_head = DWARF_UNW_CACHE_SIZE - 1;
- cache->lru_tail = 0;
- for (i = 0; i < DWARF_UNW_CACHE_SIZE; ++i)
- {
- if (i > 0)
- cache->buckets[i].lru_chain = (i - 1);
- cache->buckets[i].coll_chain = -1;
- cache->buckets[i].ip = 0;
- cache->buckets[i].valid = 0;
- }
- for (i = 0; i<DWARF_UNW_HASH_SIZE; ++i)
- cache->hash[i] = -1;
- }
- static inline struct dwarf_rs_cache *
- get_rs_cache (unw_addr_space_t as, intrmask_t *saved_maskp)
- {
- struct dwarf_rs_cache *cache = &as->global_cache;
- unw_caching_policy_t caching = as->caching_policy;
- if (caching == UNW_CACHE_NONE)
- return NULL;
- if (likely (caching == UNW_CACHE_GLOBAL))
- {
- Debug (16, "%s: acquiring lock\n", __FUNCTION__);
- lock_acquire (&cache->lock, *saved_maskp);
- }
- if (atomic_read (&as->cache_generation) != atomic_read (&cache->generation))
- {
- flush_rs_cache (cache);
- cache->generation = as->cache_generation;
- }
- return cache;
- }
- static inline void
- put_rs_cache (unw_addr_space_t as, struct dwarf_rs_cache *cache,
- intrmask_t *saved_maskp)
- {
- assert (as->caching_policy != UNW_CACHE_NONE);
- Debug (16, "unmasking signals/interrupts and releasing lock\n");
- if (likely (as->caching_policy == UNW_CACHE_GLOBAL))
- lock_release (&cache->lock, *saved_maskp);
- }
- static inline unw_hash_index_t
- hash (unw_word_t ip)
- {
- /* based on (sqrt(5)/2-1)*2^64 */
- # define magic ((unw_word_t) 0x9e3779b97f4a7c16ULL)
- return ip * magic >> ((sizeof(unw_word_t) * 8) - DWARF_LOG_UNW_HASH_SIZE);
- }
- static inline long
- cache_match (dwarf_reg_state_t *rs, unw_word_t ip)
- {
- if (rs->valid && (ip == rs->ip))
- return 1;
- return 0;
- }
- static dwarf_reg_state_t *
- rs_lookup (struct dwarf_rs_cache *cache, struct dwarf_cursor *c)
- {
- dwarf_reg_state_t *rs = cache->buckets + c->hint;
- unsigned short index;
- unw_word_t ip;
- ip = c->ip;
- if (cache_match (rs, ip))
- return rs;
- index = cache->hash[hash (ip)];
- if (index >= DWARF_UNW_CACHE_SIZE)
- return 0;
- rs = cache->buckets + index;
- while (1)
- {
- if (cache_match (rs, ip))
- {
- /* update hint; no locking needed: single-word writes are atomic */
- c->hint = cache->buckets[c->prev_rs].hint =
- (rs - cache->buckets);
- return rs;
- }
- if (rs->coll_chain >= DWARF_UNW_HASH_SIZE)
- return 0;
- rs = cache->buckets + rs->coll_chain;
- }
- }
- static inline dwarf_reg_state_t *
- rs_new (struct dwarf_rs_cache *cache, struct dwarf_cursor * c)
- {
- dwarf_reg_state_t *rs, *prev, *tmp;
- unw_hash_index_t index;
- unsigned short head;
- head = cache->lru_head;
- rs = cache->buckets + head;
- cache->lru_head = rs->lru_chain;
- /* re-insert rs at the tail of the LRU chain: */
- cache->buckets[cache->lru_tail].lru_chain = head;
- cache->lru_tail = head;
- /* remove the old rs from the hash table (if it's there): */
- if (rs->ip)
- {
- index = hash (rs->ip);
- tmp = cache->buckets + cache->hash[index];
- prev = 0;
- while (1)
- {
- if (tmp == rs)
- {
- if (prev)
- prev->coll_chain = tmp->coll_chain;
- else
- cache->hash[index] = tmp->coll_chain;
- break;
- }
- else
- prev = tmp;
- if (tmp->coll_chain >= DWARF_UNW_CACHE_SIZE)
- /* old rs wasn't in the hash-table */
- break;
- tmp = cache->buckets + tmp->coll_chain;
- }
- }
- /* enter new rs in the hash table */
- index = hash (c->ip);
- rs->coll_chain = cache->hash[index];
- cache->hash[index] = rs - cache->buckets;
- rs->hint = 0;
- rs->ip = c->ip;
- rs->valid = 1;
- rs->ret_addr_column = c->ret_addr_column;
- rs->signal_frame = 0;
- tdep_cache_frame (c, rs);
- return rs;
- }
- static int
- create_state_record_for (struct dwarf_cursor *c, dwarf_state_record_t *sr,
- unw_word_t ip)
- {
- int i, ret;
- assert (c->pi_valid);
- memset (sr, 0, sizeof (*sr));
- for (i = 0; i < DWARF_NUM_PRESERVED_REGS + 2; ++i)
- set_reg (sr, i, DWARF_WHERE_SAME, 0);
- switch (c->pi.format)
- {
- case UNW_INFO_FORMAT_TABLE:
- case UNW_INFO_FORMAT_REMOTE_TABLE:
- ret = parse_fde (c, ip, sr);
- break;
- case UNW_INFO_FORMAT_DYNAMIC:
- ret = parse_dynamic (c, ip, sr);
- break;
- default:
- Debug (1, "Unexpected unwind-info format %d\n", c->pi.format);
- ret = -UNW_EINVAL;
- }
- return ret;
- }
- static inline int
- eval_location_expr (struct dwarf_cursor *c, unw_addr_space_t as,
- unw_accessors_t *a, unw_word_t addr,
- dwarf_loc_t *locp, void *arg)
- {
- int ret, is_register;
- unw_word_t len, val;
- /* read the length of the expression: */
- if ((ret = dwarf_read_uleb128 (as, a, &addr, &len, arg)) < 0)
- return ret;
- /* evaluate the expression: */
- if ((ret = dwarf_eval_expr (c, &addr, len, &val, &is_register)) < 0)
- return ret;
- if (is_register)
- *locp = DWARF_REG_LOC (c, dwarf_to_unw_regnum (val));
- else
- *locp = DWARF_MEM_LOC (c, val);
- return 0;
- }
- static int
- apply_reg_state (struct dwarf_cursor *c, struct dwarf_reg_state *rs)
- {
- unw_word_t regnum, addr, cfa, ip;
- unw_word_t prev_ip, prev_cfa;
- unw_addr_space_t as;
- dwarf_loc_t cfa_loc;
- unw_accessors_t *a;
- int i, ret;
- void *arg;
- prev_ip = c->ip;
- prev_cfa = c->cfa;
- as = c->as;
- arg = c->as_arg;
- a = unw_get_accessors (as);
- /* Evaluate the CFA first, because it may be referred to by other
- expressions. */
- if (rs->reg[DWARF_CFA_REG_COLUMN].where == DWARF_WHERE_REG)
- {
- /* CFA is equal to [reg] + offset: */
- /* As a special-case, if the stack-pointer is the CFA and the
- stack-pointer wasn't saved, popping the CFA implicitly pops
- the stack-pointer as well. */
- if ((rs->reg[DWARF_CFA_REG_COLUMN].val == UNW_TDEP_SP)
- && (UNW_TDEP_SP < ARRAY_SIZE(rs->reg))
- && (rs->reg[UNW_TDEP_SP].where == DWARF_WHERE_SAME))
- cfa = c->cfa;
- else
- {
- regnum = dwarf_to_unw_regnum (rs->reg[DWARF_CFA_REG_COLUMN].val);
- if ((ret = unw_get_reg ((unw_cursor_t *) c, regnum, &cfa)) < 0)
- return ret;
- }
- cfa += rs->reg[DWARF_CFA_OFF_COLUMN].val;
- }
- else
- {
- /* CFA is equal to EXPR: */
- assert (rs->reg[DWARF_CFA_REG_COLUMN].where == DWARF_WHERE_EXPR);
- addr = rs->reg[DWARF_CFA_REG_COLUMN].val;
- if ((ret = eval_location_expr (c, as, a, addr, &cfa_loc, arg)) < 0)
- return ret;
- /* the returned location better be a memory location... */
- if (DWARF_IS_REG_LOC (cfa_loc))
- return -UNW_EBADFRAME;
- cfa = DWARF_GET_LOC (cfa_loc);
- }
- for (i = 0; i < DWARF_NUM_PRESERVED_REGS; ++i)
- {
- switch ((dwarf_where_t) rs->reg[i].where)
- {
- case DWARF_WHERE_UNDEF:
- c->loc[i] = DWARF_NULL_LOC;
- break;
- case DWARF_WHERE_SAME:
- break;
- case DWARF_WHERE_CFAREL:
- c->loc[i] = DWARF_MEM_LOC (c, cfa + rs->reg[i].val);
- break;
- case DWARF_WHERE_REG:
- c->loc[i] = DWARF_REG_LOC (c, dwarf_to_unw_regnum (rs->reg[i].val));
- break;
- case DWARF_WHERE_EXPR:
- addr = rs->reg[i].val;
- if ((ret = eval_location_expr (c, as, a, addr, c->loc + i, arg)) < 0)
- return ret;
- break;
- }
- }
- c->cfa = cfa;
- /* DWARF spec says undefined return address location means end of stack. */
- if (DWARF_IS_NULL_LOC (c->loc[c->ret_addr_column]))
- c->ip = 0;
- else
- {
- ret = dwarf_get (c, c->loc[c->ret_addr_column], &ip);
- if (ret < 0)
- return ret;
- c->ip = ip;
- }
- /* XXX: check for ip to be code_aligned */
- if (c->ip == prev_ip && c->cfa == prev_cfa)
- {
- Dprintf ("%s: ip and cfa unchanged; stopping here (ip=0x%lx)\n",
- __FUNCTION__, (long) c->ip);
- return -UNW_EBADFRAME;
- }
- if (c->stash_frames)
- tdep_stash_frame (c, rs);
- return 0;
- }
- static int
- uncached_dwarf_find_save_locs (struct dwarf_cursor *c)
- {
- dwarf_state_record_t sr;
- int ret;
- if ((ret = fetch_proc_info (c, c->ip, 1)) < 0)
- return ret;
- if ((ret = create_state_record_for (c, &sr, c->ip)) < 0)
- return ret;
- if ((ret = apply_reg_state (c, &sr.rs_current)) < 0)
- return ret;
- put_unwind_info (c, &c->pi);
- return 0;
- }
- /* The function finds the saved locations and applies the register
- state as well. */
- HIDDEN int
- dwarf_find_save_locs (struct dwarf_cursor *c)
- {
- dwarf_state_record_t sr;
- dwarf_reg_state_t *rs, rs_copy;
- struct dwarf_rs_cache *cache;
- int ret = 0;
- intrmask_t saved_mask;
- if (c->as->caching_policy == UNW_CACHE_NONE)
- return uncached_dwarf_find_save_locs (c);
- cache = get_rs_cache(c->as, &saved_mask);
- rs = rs_lookup(cache, c);
- if (rs)
- {
- c->ret_addr_column = rs->ret_addr_column;
- c->use_prev_instr = ! rs->signal_frame;
- }
- else
- {
- if ((ret = fetch_proc_info (c, c->ip, 1)) < 0 ||
- (ret = create_state_record_for (c, &sr, c->ip)) < 0)
- {
- put_rs_cache (c->as, cache, &saved_mask);
- return ret;
- }
- rs = rs_new (cache, c);
- memcpy(rs, &sr.rs_current, offsetof(struct dwarf_reg_state, ip));
- cache->buckets[c->prev_rs].hint = rs - cache->buckets;
- c->hint = rs->hint;
- c->prev_rs = rs - cache->buckets;
- put_unwind_info (c, &c->pi);
- }
- memcpy (&rs_copy, rs, sizeof (rs_copy));
- put_rs_cache (c->as, cache, &saved_mask);
- tdep_reuse_frame (c, &rs_copy);
- if ((ret = apply_reg_state (c, &rs_copy)) < 0)
- return ret;
- return 0;
- }
- /* The proc-info must be valid for IP before this routine can be
- called. */
- HIDDEN int
- dwarf_create_state_record (struct dwarf_cursor *c, dwarf_state_record_t *sr)
- {
- return create_state_record_for (c, sr, c->ip);
- }
- HIDDEN int
- dwarf_make_proc_info (struct dwarf_cursor *c)
- {
- #if 0
- if (c->as->caching_policy == UNW_CACHE_NONE
- || get_cached_proc_info (c) < 0)
- #endif
- /* Lookup it up the slow way... */
- return fetch_proc_info (c, c->ip, 0);
- return 0;
- }
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