PROTECTED int
unw_get_save_loc (unw_cursor_t *cursor, int reg, unw_save_loc_t *sloc)
{
struct cursor *c = (struct cursor *) cursor;
dwarf_loc_t loc;
loc = DWARF_NULL_LOC; /* default to "not saved" */
#warning FIX ME!
memset (sloc, 0, sizeof (sloc));
if (DWARF_IS_NULL_LOC (loc))
{
sloc->type = UNW_SLT_NONE;
return 0;
}
#if !defined(UNW_LOCAL_ONLY)
if (DWARF_IS_REG_LOC (loc))
{
sloc->type = UNW_SLT_REG;
sloc->u.regnum = DWARF_GET_LOC (loc);
}
else
#endif
{
sloc->type = UNW_SLT_MEMORY;
sloc->u.addr = DWARF_GET_LOC (loc);
}
return 0;
}
PROTECTED int
unw_get_save_loc (unw_cursor_t *cursor, int reg, unw_save_loc_t *sloc)
{
struct cursor *c = (struct cursor *) cursor;
dwarf_loc_t loc;
switch (reg)
{
case UNW_SH_R0:
case UNW_SH_R1:
case UNW_SH_R2:
case UNW_SH_R3:
case UNW_SH_R4:
case UNW_SH_R5:
case UNW_SH_R6:
case UNW_SH_R7:
case UNW_SH_R8:
case UNW_SH_R9:
case UNW_SH_R10:
case UNW_SH_R11:
case UNW_SH_R12:
case UNW_SH_R13:
case UNW_SH_R14:
case UNW_SH_R15:
case UNW_SH_PC:
case UNW_SH_PR:
loc = c->dwarf.loc[reg];
break;
default:
loc = DWARF_NULL_LOC; /* default to "not saved" */
break;
}
memset (sloc, 0, sizeof (*sloc));
if (DWARF_IS_NULL_LOC (loc))
{
sloc->type = UNW_SLT_NONE;
return 0;
}
#if !defined(UNW_LOCAL_ONLY)
if (DWARF_IS_REG_LOC (loc))
{
sloc->type = UNW_SLT_REG;
sloc->u.regnum = DWARF_GET_LOC (loc);
}
else
#endif
{
sloc->type = UNW_SLT_MEMORY;
sloc->u.addr = DWARF_GET_LOC (loc);
}
return 0;
}
PROTECTED int
unw_get_save_loc (unw_cursor_t *cursor, int reg, unw_save_loc_t *sloc)
{
struct cursor *c = (struct cursor *) cursor;
dwarf_loc_t loc;
loc = DWARF_NULL_LOC; /* default to "not saved" */
switch (reg)
{
case UNW_X86_64_RBX: loc = c->dwarf.loc[RBX]; break;
case UNW_X86_64_RSP: loc = c->dwarf.loc[RSP]; break;
case UNW_X86_64_RBP: loc = c->dwarf.loc[RBP]; break;
case UNW_X86_64_R12: loc = c->dwarf.loc[R12]; break;
case UNW_X86_64_R13: loc = c->dwarf.loc[R13]; break;
case UNW_X86_64_R14: loc = c->dwarf.loc[R14]; break;
case UNW_X86_64_R15: loc = c->dwarf.loc[R15]; break;
default:
break;
}
memset (sloc, 0, sizeof (unw_save_loc_t));
if (DWARF_IS_NULL_LOC (loc))
{
sloc->type = UNW_SLT_NONE;
return 0;
}
#if !defined(UNW_LOCAL_ONLY)
if (DWARF_IS_REG_LOC (loc))
{
sloc->type = UNW_SLT_REG;
sloc->u.regnum = DWARF_GET_LOC (loc);
}
else
#endif
{
sloc->type = UNW_SLT_MEMORY;
sloc->u.addr = DWARF_GET_LOC (loc);
}
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;
case DWARF_WHERE_VAL_EXPR:
addr = rs->reg[i].val;
if ((ret = eval_location_expr (c, as, a, addr, c->loc + i, arg)) < 0)
return ret;
c->loc[i] = DWARF_VAL_LOC (c, DWARF_GET_LOC (c->loc[i]));
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;
}
HIDDEN void
tdep_stash_frame (struct dwarf_cursor *d, struct dwarf_reg_state *rs)
{
struct cursor *c = (struct cursor *) dwarf_to_cursor (d);
unw_tdep_frame_t *f = &c->frame_info;
Debug (4, "ip=0x%lx cfa=0x%lx type %d cfa [where=%d val=%ld] cfaoff=%ld"
" ra=0x%lx fp [where=%d val=%ld @0x%lx] lr [where=%d val=%ld @0x%lx] "
"sp [where=%d val=%ld @0x%lx]\n",
d->ip, d->cfa, f->frame_type,
rs->reg.where[DWARF_CFA_REG_COLUMN],
rs->reg.val[DWARF_CFA_REG_COLUMN],
rs->reg.val[DWARF_CFA_OFF_COLUMN],
DWARF_GET_LOC(d->loc[rs->ret_addr_column]),
rs->reg.where[FP], rs->reg.val[FP], DWARF_GET_LOC(d->loc[FP]),
rs->reg.where[LR], rs->reg.val[LR], DWARF_GET_LOC(d->loc[LR]),
rs->reg.where[SP], rs->reg.val[SP], DWARF_GET_LOC(d->loc[SP]));
/* A standard frame is defined as:
- CFA is register-relative offset off FP or SP;
- Return address is saved in LR;
- FP is unsaved or saved at CFA+offset, offset != -1;
- LR is unsaved or saved at CFA+offset, offset != -1;
- SP is unsaved or saved at CFA+offset, offset != -1. */
if (f->frame_type == UNW_AARCH64_FRAME_OTHER
&& (rs->reg.where[DWARF_CFA_REG_COLUMN] == DWARF_WHERE_REG)
&& (rs->reg.val[DWARF_CFA_REG_COLUMN] == FP
|| rs->reg.val[DWARF_CFA_REG_COLUMN] == SP)
&& labs(rs->reg.val[DWARF_CFA_OFF_COLUMN]) < (1 << 29)
&& rs->ret_addr_column == LR
&& (rs->reg.where[FP] == DWARF_WHERE_UNDEF
|| rs->reg.where[FP] == DWARF_WHERE_SAME
|| (rs->reg.where[FP] == DWARF_WHERE_CFAREL
&& labs(rs->reg.val[FP]) < (1 << 29)
&& rs->reg.val[FP]+1 != 0))
&& (rs->reg.where[LR] == DWARF_WHERE_UNDEF
|| rs->reg.where[LR] == DWARF_WHERE_SAME
|| (rs->reg.where[LR] == DWARF_WHERE_CFAREL
&& labs(rs->reg.val[LR]) < (1 << 29)
&& rs->reg.val[LR]+1 != 0))
&& (rs->reg.where[SP] == DWARF_WHERE_UNDEF
|| rs->reg.where[SP] == DWARF_WHERE_SAME
|| (rs->reg.where[SP] == DWARF_WHERE_CFAREL
&& labs(rs->reg.val[SP]) < (1 << 29)
&& rs->reg.val[SP]+1 != 0)))
{
/* Save information for a standard frame. */
f->frame_type = UNW_AARCH64_FRAME_STANDARD;
f->cfa_reg_sp = (rs->reg.val[DWARF_CFA_REG_COLUMN] == SP);
f->cfa_reg_offset = rs->reg.val[DWARF_CFA_OFF_COLUMN];
if (rs->reg.where[FP] == DWARF_WHERE_CFAREL)
f->fp_cfa_offset = rs->reg.val[FP];
if (rs->reg.where[LR] == DWARF_WHERE_CFAREL)
f->lr_cfa_offset = rs->reg.val[LR];
if (rs->reg.where[SP] == DWARF_WHERE_CFAREL)
f->sp_cfa_offset = rs->reg.val[SP];
Debug (4, " standard frame\n");
}
else
Debug (4, " unusual frame\n");
}
HIDDEN void
tdep_stash_frame (struct dwarf_cursor *d, struct dwarf_reg_state *rs)
{
struct cursor *c = (struct cursor *) dwarf_to_cursor (d);
unw_tdep_frame_t *f = &c->frame_info;
Debug (4, "ip=0x%lx cfa=0x%lx type %d cfa [where=%d val=%ld] cfaoff=%ld"
" ra=0x%lx rbp [where=%d val=%ld @0x%lx] rsp [where=%d val=%ld @0x%lx]\n",
d->ip, d->cfa, f->frame_type,
rs->reg[DWARF_CFA_REG_COLUMN].where,
rs->reg[DWARF_CFA_REG_COLUMN].val,
rs->reg[DWARF_CFA_OFF_COLUMN].val,
DWARF_GET_LOC(d->loc[d->ret_addr_column]),
rs->reg[RBP].where, rs->reg[RBP].val, DWARF_GET_LOC(d->loc[RBP]),
rs->reg[RSP].where, rs->reg[RSP].val, DWARF_GET_LOC(d->loc[RSP]));
/* A standard frame is defined as:
- CFA is register-relative offset off RBP or RSP;
- Return address is saved at CFA-8;
- RBP is unsaved or saved at CFA+offset, offset != -1;
- RSP is unsaved or saved at CFA+offset, offset != -1. */
if (f->frame_type == UNW_X86_64_FRAME_OTHER
&& (rs->reg[DWARF_CFA_REG_COLUMN].where == DWARF_WHERE_REG)
&& (rs->reg[DWARF_CFA_REG_COLUMN].val == RBP
|| rs->reg[DWARF_CFA_REG_COLUMN].val == RSP)
&& labs((long) rs->reg[DWARF_CFA_OFF_COLUMN].val) < (1 << 29)
&& DWARF_GET_LOC(d->loc[d->ret_addr_column]) == d->cfa-8
&& (rs->reg[RBP].where == DWARF_WHERE_UNDEF
|| rs->reg[RBP].where == DWARF_WHERE_SAME
|| (rs->reg[RBP].where == DWARF_WHERE_CFAREL
&& labs((long) rs->reg[RBP].val) < (1 << 14)
&& rs->reg[RBP].val+1 != 0))
&& (rs->reg[RSP].where == DWARF_WHERE_UNDEF
|| rs->reg[RSP].where == DWARF_WHERE_SAME
|| (rs->reg[RSP].where == DWARF_WHERE_CFAREL
&& labs((long) rs->reg[RSP].val) < (1 << 14)
&& rs->reg[RSP].val+1 != 0)))
{
/* Save information for a standard frame. */
f->frame_type = UNW_X86_64_FRAME_STANDARD;
f->cfa_reg_rsp = (rs->reg[DWARF_CFA_REG_COLUMN].val == RSP);
f->cfa_reg_offset = rs->reg[DWARF_CFA_OFF_COLUMN].val;
if (rs->reg[RBP].where == DWARF_WHERE_CFAREL)
f->rbp_cfa_offset = rs->reg[RBP].val;
if (rs->reg[RSP].where == DWARF_WHERE_CFAREL)
f->rsp_cfa_offset = rs->reg[RSP].val;
Debug (4, " standard frame\n");
}
/* Signal frame was detected via augmentation in tdep_fetch_frame() */
else if (f->frame_type == UNW_X86_64_FRAME_SIGRETURN)
{
/* Later we are going to fish out {RBP,RSP,RIP} from sigcontext via
their ucontext_t offsets. Confirm DWARF info agrees with the
offsets we expect. */
#ifndef NDEBUG
const unw_word_t uc = c->sigcontext_addr;
assert (DWARF_GET_LOC(d->loc[RIP]) - uc == UC_MCONTEXT_GREGS_RIP);
assert (DWARF_GET_LOC(d->loc[RBP]) - uc == UC_MCONTEXT_GREGS_RBP);
assert (DWARF_GET_LOC(d->loc[RSP]) - uc == UC_MCONTEXT_GREGS_RSP);
#endif
Debug (4, " sigreturn frame\n");
}
/* PLT and guessed RBP-walked frames are handled in unw_step(). */
else
Debug (4, " unusual frame\n");
}
PROTECTED int
unw_step (unw_cursor_t *cursor)
{
struct cursor *c = (struct cursor *) cursor;
int ret, i;
Debug (1, "(cursor=%p, ip=0x%08x)\n", c, (unsigned) c->dwarf.ip);
/* ANDROID support update. */
/* Save the current ip/cfa to prevent looping if the decode yields
the same ip/cfa as before. */
unw_word_t old_ip = c->dwarf.ip;
unw_word_t old_cfa = c->dwarf.cfa;
/* End of ANDROID update. */
/* Try DWARF-based unwinding... */
ret = dwarf_step (&c->dwarf);
#if !defined(UNW_LOCAL_ONLY)
/* Do not use this method on a local unwind. There is a very high
* probability this method will try to access unmapped memory, which
* will crash the process. Since this almost never actually works,
* it should be okay to skip.
*/
if (ret < 0)
{
/* DWARF failed, let's see if we can follow the frame-chain
or skip over the signal trampoline. */
struct dwarf_loc ebp_loc, eip_loc;
/* We could get here because of missing/bad unwind information.
Validate all addresses before dereferencing. */
c->validate = 1;
Debug (13, "dwarf_step() failed (ret=%d), trying frame-chain\n", ret);
if (unw_is_signal_frame (cursor))
{
ret = unw_handle_signal_frame(cursor);
if (ret < 0)
{
Debug (2, "returning 0\n");
return 0;
}
}
else
{
ret = dwarf_get (&c->dwarf, c->dwarf.loc[EBP], &c->dwarf.cfa);
if (ret < 0)
{
Debug (2, "returning %d\n", ret);
return ret;
}
Debug (13, "[EBP=0x%x] = 0x%x\n", DWARF_GET_LOC (c->dwarf.loc[EBP]),
c->dwarf.cfa);
ebp_loc = DWARF_LOC (c->dwarf.cfa, 0);
eip_loc = DWARF_LOC (c->dwarf.cfa + 4, 0);
c->dwarf.cfa += 8;
/* Mark all registers unsaved, since we don't know where
they are saved (if at all), except for the EBP and
EIP. */
for (i = 0; i < DWARF_NUM_PRESERVED_REGS; ++i)
c->dwarf.loc[i] = DWARF_NULL_LOC;
c->dwarf.loc[EBP] = ebp_loc;
c->dwarf.loc[EIP] = eip_loc;
}
c->dwarf.ret_addr_column = EIP;
if (!DWARF_IS_NULL_LOC (c->dwarf.loc[EBP]))
{
ret = dwarf_get (&c->dwarf, c->dwarf.loc[EIP], &c->dwarf.ip);
if (ret < 0)
{
Debug (13, "dwarf_get([EIP=0x%x]) failed\n", DWARF_GET_LOC (c->dwarf.loc[EIP]));
Debug (2, "returning %d\n", ret);
return ret;
}
else
{
Debug (13, "[EIP=0x%x] = 0x%x\n", DWARF_GET_LOC (c->dwarf.loc[EIP]),
c->dwarf.ip);
}
}
else
c->dwarf.ip = 0;
}
#endif
/* ANDROID support update. */
if (ret >= 0)
{
if (c->dwarf.ip)
{
/* Adjust the pc to the instruction before. */
c->dwarf.ip--;
}
/* If the decode yields the exact same ip/cfa as before, then indicate
the unwind is complete. */
if (old_ip == c->dwarf.ip && old_cfa == c->dwarf.cfa)
{
Dprintf ("%s: ip and cfa unchanged; stopping here (ip=0x%lx)\n",
__FUNCTION__, (long) c->dwarf.ip);
return -UNW_EBADFRAME;
}
c->dwarf.frame++;
}
/* End of ANDROID update. */
if (unlikely (ret <= 0))
return 0;
return (c->dwarf.ip == 0) ? 0 : 1;
}
PROTECTED int
unw_step (unw_cursor_t *cursor)
{
struct cursor *c = (struct cursor *) cursor;
int ret, i;
Debug (1, "(cursor=%p, ip=0x%08x)\n", c, (unsigned) c->dwarf.ip);
/* Try DWARF-based unwinding... */
ret = dwarf_step (&c->dwarf);
if (ret < 0 && ret != -UNW_ENOINFO)
{
Debug (2, "returning %d\n", ret);
return ret;
}
if (unlikely (ret < 0))
{
/* DWARF failed, let's see if we can follow the frame-chain
or skip over the signal trampoline. */
struct dwarf_loc ebp_loc, eip_loc;
/* We could get here because of missing/bad unwind information.
Validate all addresses before dereferencing. */
c->validate = 1;
Debug (13, "dwarf_step() failed (ret=%d), trying frame-chain\n", ret);
if (unw_is_signal_frame (cursor))
{
ret = unw_handle_signal_frame(cursor);
if (ret < 0)
{
Debug (2, "returning 0\n");
return 0;
}
}
else
{
ret = dwarf_get (&c->dwarf, c->dwarf.loc[EBP], &c->dwarf.cfa);
if (ret < 0)
{
Debug (2, "returning %d\n", ret);
return ret;
}
Debug (13, "[EBP=0x%x] = 0x%x\n", DWARF_GET_LOC (c->dwarf.loc[EBP]),
c->dwarf.cfa);
ebp_loc = DWARF_LOC (c->dwarf.cfa, 0);
eip_loc = DWARF_LOC (c->dwarf.cfa + 4, 0);
c->dwarf.cfa += 8;
/* Mark all registers unsaved, since we don't know where
they are saved (if at all), except for the EBP and
EIP. */
for (i = 0; i < DWARF_NUM_PRESERVED_REGS; ++i)
c->dwarf.loc[i] = DWARF_NULL_LOC;
c->dwarf.loc[EBP] = ebp_loc;
c->dwarf.loc[EIP] = eip_loc;
}
c->dwarf.ret_addr_column = EIP;
if (!DWARF_IS_NULL_LOC (c->dwarf.loc[EBP]))
{
ret = dwarf_get (&c->dwarf, c->dwarf.loc[EIP], &c->dwarf.ip);
if (ret < 0)
{
Debug (13, "dwarf_get([EIP=0x%x]) failed\n", DWARF_GET_LOC (c->dwarf.loc[EIP]));
Debug (2, "returning %d\n", ret);
return ret;
}
else
{
Debug (13, "[EIP=0x%x] = 0x%x\n", DWARF_GET_LOC (c->dwarf.loc[EIP]),
c->dwarf.ip);
}
}
else
c->dwarf.ip = 0;
}
ret = (c->dwarf.ip == 0) ? 0 : 1;
Debug (2, "returning %d\n", ret);
return ret;
}