def bregN(self, regnum):
'''The single operand of the DW_OP_bregn operations provides a signed LEB128 offset from the specified
register.'''
offset = SLEB.decode(self.expression)
if offset > 0:
self.push('(char *) get_reg(%i) + %#x' % (regnum, offset))
elif offset < 0:
self.push('(char *) get_reg(%i) - %#x' % (regnum, abs(offset)))
else:
self.push('(char *) get_reg(%i)' % (regnum))
def bregN(self, regnum):
'''The single operand of the DW_OP_bregn operations provides a signed LEB128 offset from the specified
register.'''
offset = SLEB.decode(self.expression)
if offset > 0:
self.push('(char *) get_reg(%i) + %#x' % (regnum, offset))
elif offset < 0:
self.push('(char *) get_reg(%i) - %#x' % (regnum, abs(offset)))
else:
self.push('(char *) get_reg(%i)' % (regnum))
def fbreg(self):
'''The DW_OP_fbreg operation provides a signed LEB128 offset from the address specified by the location
description in the DW_AT_frame_base attribute of the current function. (This is typically a "stack pointer"
register plus or minus some offset. On more sophisticated systems it might be a location list that adjusts
the offset according to changes in the stack pointer as the PC changes.)'''
offset = SLEB.decode(self.expression)
if offset > 0:
self.push('__adbi_frame__ + %#x' % offset)
elif offset < 0:
self.push('__adbi_frame__ - %#x' % abs(offset))
else:
self.push('__adbi_frame__')
self.uses_frame = True
def fbreg(self):
'''The DW_OP_fbreg operation provides a signed LEB128 offset from the address specified by the location
description in the DW_AT_frame_base attribute of the current function. (This is typically a "stack pointer"
register plus or minus some offset. On more sophisticated systems it might be a location list that adjusts
the offset according to changes in the stack pointer as the PC changes.)'''
offset = SLEB.decode(self.expression)
if offset > 0:
self.push('__adbi_frame__ + %#x' % offset)
elif offset < 0:
self.push('__adbi_frame__ - %#x' % abs(offset))
else:
self.push('__adbi_frame__')
self.uses_frame = True
def iter_entries():
if not self.debug_info.dwarf.has_CFI():
logging.warn('ELF has no call frame information.')
return
for fde in self.debug_info.dwarf.CFI_entries():
if not isinstance(fde, FDE):
continue
low = fde.header.initial_location
high = low + fde.header.address_range
invalid = False
decoded = fde.get_decoded().table
for n, each in enumerate(decoded, 0):
try:
entry_low = debug_info.addr2fo(each['pc'])
entry_high = debug_info.addr2fo(
high if n >= len(decoded) -
1 else decoded[n + 1]['pc'])
except ValueError:
invalid = True
continue
cfa_rule = each['cfa']
if cfa_rule.expr is not None:
# CFA is a regular DWARF expressions
expr = cfa_rule.expr
else:
assert cfa_rule.reg is not None
# CFA is a register + offset -- convert it to a DWARF expression
expr = bytearray([0x92]) # DW_OP_bregx
expr += LEB.encode(cfa_rule.reg) # Register index
expr += SLEB.encode(
cfa_rule.offset) # Offset from register
yield CallFrameInfoEntry(entry_low, entry_high,
b64encode(expr))
if invalid:
logging.warn(
'Invalid call frame information entry encountered in FDE at %#x.',
fde.offset)
def iter_entries():
if not self.debug_info.dwarf.has_CFI():
logging.warn('ELF has no call frame information.')
return
for fde in self.debug_info.dwarf.CFI_entries():
if not isinstance(fde, FDE):
continue
low = fde.header.initial_location
high = low + fde.header.address_range
invalid = False
decoded = fde.get_decoded().table
for n, each in enumerate(decoded, 0):
try:
entry_low = debug_info.addr2fo(each['pc'])
entry_high = debug_info.addr2fo(high if n >= len(decoded) - 1 else decoded[n + 1]['pc'])
except ValueError:
invalid = True
continue
cfa_rule = each['cfa']
if cfa_rule.expr is not None:
# CFA is a regular DWARF expressions
expr = cfa_rule.expr
else:
assert cfa_rule.reg is not None
# CFA is a register + offset -- convert it to a DWARF expression
expr = bytearray([0x92]) # DW_OP_bregx
expr += LEB.encode(cfa_rule.reg) # Register index
expr += SLEB.encode(cfa_rule.offset) # Offset from register
yield CallFrameInfoEntry(entry_low, entry_high, b64encode(expr))
if invalid:
logging.warn('Invalid call frame information entry encountered in FDE at %#x.', fde.offset)
def consts(self):
'''The single operand of the DW_OP_consts operation provides a signed LEB128 integer constant.'''
val = SLEB.decode(self.expression)
self.push('%#x' % val)
def consts(self):
'''The single operand of the DW_OP_consts operation provides a signed LEB128 integer constant.'''
val = SLEB.decode(self.expression)
self.push('%#x' % val)
