def get_op(ea, op, stkvars=None):
'''ea_t -> int -> opt:{int : tinfo_t} -> op_ret'''
cmd = idautils.DecodeInstruction(ea)
cmd.Operands = get_operands(cmd) # for mips_op_hack
op = mips_op_hack(cmd, op)
opd = cmd[op]
if opd.type == idaapi.o_reg: # gpr, XXX sorta MIPS-specific
return op_ret(op_ty.reg, regs.gpr(opd.reg), 0)
elif opd.type == idaapi.o_idpspec1: # fpr, XXX sorta MIPS-specific
return op_ret(op_ty.reg, regs.fpr(opd.reg), 0)
elif opd.type in [idaapi.o_near, idaapi.o_mem]:
return op_ret(op_ty.name, idc.Name(opd.addr), 0)
elif idc.isStkvar1(idc.GetFlags(ea)):
# IDA seems to set this flag even for operands beyond the second,
# i.e. both of these are true for isStkvar1:
# .text:10003A84 sd $a1, 0x2E0+var_58($sp)
# .text:10003A68 addiu $a1, $sp, 0x2E0+var_2D8
try:
func = idaapi.get_func(ea)
off = idaapi.calc_stkvar_struc_offset(func, ea, op)
(name, ti) = stkvars[off]
return op_ret_for_ti(ti, name, off, off)
except KeyError:
raise OperandUnresolvableError('unable to get operand %u at %s' % (op, idc.atoa(ea)))
elif opd.type in [idaapi.o_imm, idaapi.o_displ]:
return cpu_ida.ida_current_cpu().data.get_op_addrmode(ea, op, cmd)
else:
raise OperandUnresolvableError('unable to get operand %u at %s' % (op, idc.atoa(ea)))
def get_op(ea, op, stkvars=None):
'''ea_t -> int -> opt:{int : tinfo_t} -> op_ret'''
cmd = idautils.DecodeInstruction(ea)
cmd.Operands = get_operands(cmd) # for mips_op_hack
op = mips_op_hack(cmd, op)
opd = cmd[op]
if opd.type == idaapi.o_reg: # gpr, XXX sorta MIPS-specific
return op_ret(op_ty.reg, regs.gpr(opd.reg), 0)
elif opd.type == idaapi.o_idpspec1: # fpr, XXX sorta MIPS-specific
return op_ret(op_ty.reg, regs.fpr(opd.reg), 0)
elif opd.type in [idaapi.o_near, idaapi.o_mem]:
return op_ret(op_ty.name, idc.Name(opd.addr), 0)
elif idc.isStkvar1(idc.GetFlags(ea)):
# IDA seems to set this flag even for operands beyond the second,
# i.e. both of these are true for isStkvar1:
# .text:10003A84 sd $a1, 0x2E0+var_58($sp)
# .text:10003A68 addiu $a1, $sp, 0x2E0+var_2D8
try:
func = idaapi.get_func(ea)
off = idaapi.calc_stkvar_struc_offset(func, ea, op)
(name, ti) = stkvars[off]
return op_ret_for_ti(ti, name, off, off)
except KeyError:
raise OperandUnresolvableError('unable to get operand %u at %s' %
(op, idc.atoa(ea)))
elif opd.type in [idaapi.o_imm, idaapi.o_displ]:
return cpu_ida.ida_current_cpu().data.get_op_addrmode(ea, op, cmd)
else:
raise OperandUnresolvableError('unable to get operand %u at %s' %
(op, idc.atoa(ea)))
def type_to_reg_and_slot(node, chooser, i):
'''c_ast -> fn -> int -> (reg_type, slot_type) | None'''
def yield_void():
# return an empty list for (void) arglists
raise StopIteration
def maybe_fail(node):
if type(node) is c_ast.Struct:
raise StructByValueError('structs by value not yet supported')
return type_to_reg_and_slot(node.type, chooser, i)
def get(names):
'''[str] -> (gpr|fpr, slot_ty)'''
if 'void' in names:
return yield_void()
ti = ida.parse_decl(' '.join(names))
(ty, base, slot) = chooser(ti)
return (ty(base + i), slot)
sw = {
c_ast.Decl: lambda x: type_to_reg_and_slot(x.type, chooser, i),
c_ast.TypeDecl: lambda x: type_to_reg_and_slot(x.type, chooser, i),
c_ast.Typename: lambda x: type_to_reg_and_slot(x.type, chooser, i),
c_ast.IdentifierType: lambda x: get(x.names)
}
if i > 7:
raise RegSpillError('spilling registers to stack not yet supported')
# in order to use chooser we need a tinfo_t--make one suitable for an
# an int (which is also suitable for a pointer on N32)
dummy_ti = ida.parse_decl('int')
(_, base, _) = chooser(dummy_ti)
node_ty = type(node)
if node_ty in [c_ast.ArrayDecl, c_ast.PtrDecl]:
return (regs.gpr(base + i), ep_ct.slot_types.u64)
elif node_ty is c_ast.Enum:
return (regs.gpr(base + i), ep_ct.slot_types.i64)
else:
return utils.dictswitch(node_ty, sw, node, maybe_fail, node)
def type_to_reg_and_slot(node, chooser, i):
'''c_ast -> fn -> int -> (reg_type, slot_type) | None'''
def yield_void():
# return an empty list for (void) arglists
raise StopIteration
def maybe_fail(node):
if type(node) is c_ast.Struct:
raise StructByValueError('structs by value not yet supported')
return type_to_reg_and_slot(node.type, chooser, i)
def get(names):
'''[str] -> (gpr|fpr, slot_ty)'''
if 'void' in names:
return yield_void()
ti = ida.parse_decl(' '.join(names))
(ty, base, slot) = chooser(ti)
return (ty(base + i), slot)
sw = {
c_ast.Decl : lambda x: type_to_reg_and_slot(x.type, chooser, i),
c_ast.TypeDecl : lambda x: type_to_reg_and_slot(x.type, chooser, i),
c_ast.Typename : lambda x: type_to_reg_and_slot(x.type, chooser, i),
c_ast.IdentifierType : lambda x: get(x.names)
}
if i > 7:
raise RegSpillError('spilling registers to stack not yet supported')
# in order to use chooser we need a tinfo_t--make one suitable for an
# an int (which is also suitable for a pointer on N32)
dummy_ti = ida.parse_decl('int')
(_, base, _) = chooser(dummy_ti)
node_ty = type(node)
if node_ty in [c_ast.ArrayDecl, c_ast.PtrDecl]:
return (regs.gpr(base + i), ep_ct.slot_types.u64)
elif node_ty is c_ast.Enum:
return (regs.gpr(base + i), ep_ct.slot_types.i64)
else:
return utils.dictswitch(node_ty, sw, node, maybe_fail, node)
def get_arg_for_va_function(callee, start_ea):
'''str -> ea_t -> str'''
# XXX hacky; not a very general function
# XXX imperative
# get a relevant item needed for processing a variadic function
sw = {
'printf' : regs.gpr(abi.arg_regs[0]),
'scanf' : regs.gpr(abi.arg_regs[0]),
'sscanf' : regs.gpr(abi.arg_regs[1])
}
try:
wanted_reg = sw[callee]
except KeyError:
raise utils.BugError('unrecognized callee %s' % callee)
distance = 0
fn = ida.get_func(start_ea)
# first, look at the delay slot
ea = ida.next_head(start_ea, fn.endEA)
while True:
if distance > 10:
raise VarargsError(
'gave up looking for needed varargs argument for %s between ' +
'%s..%s' % (ida.atoa(ea), ida.atoa(start_ea)))
if ea == start_ea:
ea = ida.prev_head(ea)
continue # skip the call insn
elif list(ida.code_refs_from(ea, 0)) != []:
raise VarargsError(
'encountered branch/jump while looking for varargs argument ' +
'between %s..%s' % (ida.atoa(ea), ida.atoa(start_ea)))
rd = ida.get_op(ea, 0)
if rd.val == wanted_reg:
opvals = ida.get_opvals(ea) # XXX should try to track stkvar values
s = ida.get_string(opvals[-1].target)
if s is not None:
return s
ea = ida.prev_head(ea)
distance += 1
def get_arg_for_va_function(callee, start_ea):
"""str -> ea_t -> str"""
# XXX hacky; not a very general function
# XXX imperative
# get a relevant item needed for processing a variadic function
sw = {"printf": regs.gpr(abi.arg_regs[0]), "scanf": regs.gpr(abi.arg_regs[0]), "sscanf": regs.gpr(abi.arg_regs[1])}
try:
wanted_reg = sw[callee]
except KeyError:
raise utils.BugError("unrecognized callee %s" % callee)
distance = 0
fn = ida.get_func(start_ea)
# first, look at the delay slot
ea = ida.next_head(start_ea, fn.endEA)
while True:
if distance > 10:
raise VarargsError(
"gave up looking for needed varargs argument for %s between "
+ "%s..%s" % (ida.atoa(ea), ida.atoa(start_ea))
)
if ea == start_ea:
ea = ida.prev_head(ea)
continue # skip the call insn
elif list(ida.code_refs_from(ea, 0)) != []:
raise VarargsError(
"encountered branch/jump while looking for varargs argument "
+ "between %s..%s" % (ida.atoa(ea), ida.atoa(start_ea))
)
rd = ida.get_op(ea, 0)
if rd.val == wanted_reg:
opvals = ida.get_opvals(ea) # XXX should try to track stkvar values
s = ida.get_string(opvals[-1].target)
if s is not None:
return s
ea = ida.prev_head(ea)
distance += 1
def get_op_addrmode(ea, op, cmd):
'''ea_t -> int -> insn_t -> op_ret'''
# the ida module calls back into this module to deal with some MIPS-specific
# operand handling here
mnem = ida.get_mnem(ea)
op = ida.mips_op_hack(cmd, op)
if cmd[op].type == ida.o_imm:
val = cmd[op].value
elif cmd[op].type == ida.o_displ:
val = cmd[op].addr
else:
raise utils.BugError('neither imm nor displ passed to get_op_addrmode')
if mnem in insns.has_special_opnd:
target = val
return ida.resolve_opnd(target, val)
# addiu is often used for address calculation, which IDA will resolve to a
# name, so handle addiu's immval only if we fail to resolve it later
elif mnem != 'addiu' and mnem in insns.has_imm:
return ida.op_ret(ida.op_ty.value, immval(val), 0)
else:
target = ida.calc_target(ea, ea, op, immval(val))
if target == ida.BADADDR and cmd[op].type == ida.o_displ:
reg = cmd[op].reg
if reg >= 0 and reg <= 31:
reg = regs.gpr(reg)
elif reg >= 32 and reg <= 63:
reg = regs.fpr(reg)
else:
raise utils.BugError('bogus register %u' % reg)
return ida.op_ret(ida.op_ty.displ,
ida.displ(reg=reg,
displ=immval(val)),
0)
else:
opnd = ida.resolve_opnd(target, val)
if mnem == 'addiu' and opnd.ty == ida.op_ty.value:
# addiu is being used for regular addition; handle its third
# operand as an immediate value
return ida.op_ret(ida.op_ty.value, immval(opnd.val), 0)
else:
return opnd
def fmt_reg(mnem, arg, slot=None):
'''str -> int -> reg -> opt:slot_types -> str'''
if arg == regs.gpr(0):
return c_ast.Constant('int', '0')
else:
insn = insns.insns[mnem]
stripped = reg_strip(arg)
# XXX FIXME: we store the register gpr/fpr register number, but
# regs_by_reference is offsets into IDA's register list
regnum = arg.reg + (abi.fpr_off if type(arg) is regs.fpr else 0)
if regnum in abi.regs_by_reference:
# refer to argument via ARGS->
r = c_ast.StructRef(c_ast.ID(utils.args_tag), '->', c_ast.ID(stripped))
else:
r = c_ast.ID(stripped)
if slot is not None and slot != ep_ct.slot_types._:
# use a union slot
return c_ast.StructRef(r, '.', c_ast.ID(slot.name))
else:
return r
def get_op_addrmode(ea, op, cmd):
"""ea_t -> int -> insn_t -> op_ret"""
# the ida module calls back into this module to deal with some MIPS-specific
# operand handling here
mnem = ida.get_mnem(ea)
op = ida.mips_op_hack(cmd, op)
if cmd[op].type == ida.o_imm:
val = cmd[op].value
elif cmd[op].type == ida.o_displ:
val = cmd[op].addr
else:
raise utils.BugError("neither imm nor displ passed to get_op_addrmode")
if mnem in insns.has_special_opnd:
target = val
return ida.resolve_opnd(target, val)
# addiu is often used for address calculation, which IDA will resolve to a
# name, so handle addiu's immval only if we fail to resolve it later
elif mnem != "addiu" and mnem in insns.has_imm:
return ida.op_ret(ida.op_ty.value, immval(val), 0)
else:
target = ida.calc_target(ea, ea, op, immval(val))
if target == ida.BADADDR and cmd[op].type == ida.o_displ:
reg = cmd[op].reg
if reg >= 0 and reg <= 31:
reg = regs.gpr(reg)
elif reg >= 32 and reg <= 63:
reg = regs.fpr(reg)
else:
raise utils.BugError("bogus register %u" % reg)
return ida.op_ret(ida.op_ty.displ, ida.displ(reg=reg, displ=immval(val)), 0)
else:
opnd = ida.resolve_opnd(target, val)
if mnem == "addiu" and opnd.ty == ida.op_ty.value:
# addiu is being used for regular addition; handle its third
# operand as an immediate value
return ida.op_ret(ida.op_ty.value, immval(opnd.val), 0)
else:
return opnd
