PROTECTED int
unw_step (unw_cursor_t *cursor)
{
struct cursor *c = (struct cursor *) cursor;
int ret = -UNW_EUNSPEC;
Debug (1, "(cursor=%p)\n", c);
/* Check if this is a signal frame. */
if (unw_is_signal_frame (cursor))
return unw_handle_signal_frame (cursor);
#ifdef CONFIG_DEBUG_FRAME
/* First, try DWARF-based unwinding. */
if (UNW_TRY_METHOD(UNW_ARM_METHOD_DWARF))
{
ret = dwarf_step (&c->dwarf);
Debug(1, "dwarf_step()=%d\n", ret);
if (likely (ret > 0))
return 1;
else if (unlikely (ret == -UNW_ESTOPUNWIND))
return ret;
if (ret < 0 && ret != -UNW_ENOINFO)
{
Debug (2, "returning %d\n", ret);
return ret;
}
}
#endif /* CONFIG_DEBUG_FRAME */
/* Next, try extbl-based unwinding. */
if (UNW_TRY_METHOD (UNW_ARM_METHOD_EXIDX))
{
ret = arm_exidx_step (c);
if (ret > 0)
return 1;
if (ret == -UNW_ESTOPUNWIND || ret == 0)
return ret;
}
/* Fall back on APCS frame parsing.
Note: This won't work in case the ARM EABI is used. */
if (unlikely (ret < 0))
{
if (UNW_TRY_METHOD(UNW_ARM_METHOD_FRAME))
{
ret = UNW_ESUCCESS;
/* DWARF unwinding failed, try to follow APCS/optimized APCS frame chain */
unw_word_t instr, i;
Debug (13, "dwarf_step() failed (ret=%d), trying frame-chain\n", ret);
dwarf_loc_t ip_loc, fp_loc;
unw_word_t frame;
/* Mark all registers unsaved, since we don't know where
they are saved (if at all), except for the EBP and
EIP. */
if (dwarf_get(&c->dwarf, c->dwarf.loc[UNW_ARM_R11], &frame) < 0)
{
return 0;
}
for (i = 0; i < DWARF_NUM_PRESERVED_REGS; ++i) {
c->dwarf.loc[i] = DWARF_NULL_LOC;
}
if (frame)
{
if (dwarf_get(&c->dwarf, DWARF_LOC(frame, 0), &instr) < 0)
{
return 0;
}
instr -= 8;
if (dwarf_get(&c->dwarf, DWARF_LOC(instr, 0), &instr) < 0)
{
return 0;
}
if ((instr & 0xFFFFD800) == 0xE92DD800)
{
/* Standard APCS frame. */
ip_loc = DWARF_LOC(frame - 4, 0);
fp_loc = DWARF_LOC(frame - 12, 0);
}
else
{
/* Codesourcery optimized normal frame. */
ip_loc = DWARF_LOC(frame, 0);
fp_loc = DWARF_LOC(frame - 4, 0);
}
if (dwarf_get(&c->dwarf, ip_loc, &c->dwarf.ip) < 0)
{
return 0;
}
c->dwarf.loc[UNW_ARM_R12] = ip_loc;
c->dwarf.loc[UNW_ARM_R11] = fp_loc;
Debug(15, "ip=%lx\n", c->dwarf.ip);
}
else
{
ret = -UNW_ENOINFO;
}
}
}
return ret == -UNW_ENOINFO ? 0 : 1;
}
PROTECTED int
unw_step (unw_cursor_t *cursor)
{
struct cursor *c = (struct cursor *) cursor;
int ret = -UNW_EUNSPEC;
Debug (1, "(cursor=%p)\n", c);
/* Try DWARF-based unwinding... this is the only method likely to work for
ARM. */
if (UNW_TRY_METHOD(UNW_ARM_METHOD_DWARF))
{
ret = dwarf_step (&c->dwarf);
Debug(1, "dwarf_step()=%d\n", ret);
if (unlikely (ret == -UNW_ESTOPUNWIND))
return ret;
if (ret < 0 && ret != -UNW_ENOINFO)
{
Debug (2, "returning %d\n", ret);
return ret;
}
}
if (unlikely (ret < 0))
{
if (UNW_TRY_METHOD(UNW_ARM_METHOD_FRAME))
{
ret = UNW_ESUCCESS;
/* DWARF unwinding failed, try to follow APCS/optimized APCS frame chain */
unw_word_t instr, i;
Debug (13, "dwarf_step() failed (ret=%d), trying frame-chain\n", ret);
dwarf_loc_t ip_loc, fp_loc;
unw_word_t frame;
/* Mark all registers unsaved, since we don't know where
they are saved (if at all), except for the EBP and
EIP. */
if (dwarf_get(&c->dwarf, c->dwarf.loc[UNW_ARM_R11], &frame) < 0)
{
return 0;
}
for (i = 0; i < DWARF_NUM_PRESERVED_REGS; ++i) {
c->dwarf.loc[i] = DWARF_NULL_LOC;
}
if (frame)
{
if (dwarf_get(&c->dwarf, DWARF_LOC(frame, 0), &instr) < 0)
{
return 0;
}
instr -= 8;
if (dwarf_get(&c->dwarf, DWARF_LOC(instr, 0), &instr) < 0)
{
return 0;
}
if ((instr & 0xFFFFD800) == 0xE92DD800)
{
/* Standard APCS frame. */
ip_loc = DWARF_LOC(frame - 4, 0);
fp_loc = DWARF_LOC(frame - 12, 0);
}
else
{
/* Codesourcery optimized normal frame. */
ip_loc = DWARF_LOC(frame, 0);
fp_loc = DWARF_LOC(frame - 4, 0);
}
if (dwarf_get(&c->dwarf, ip_loc, &c->dwarf.ip) < 0)
{
return 0;
}
c->dwarf.loc[UNW_ARM_R12] = ip_loc;
c->dwarf.loc[UNW_ARM_R11] = fp_loc;
Debug(15, "ip=%lx\n", c->dwarf.ip);
}
else
{
ret = -UNW_ENOINFO;
}
}
}
return ret == -UNW_ENOINFO ? 0 : 1;
}
