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llvm-project/lldb/source/Plugins/Instruction/ARM64/EmulateInstructionARM64.cpp

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//===-- EmulateInstructionARM64.cpp ---------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "EmulateInstructionARM64.h"
#include "lldb/Core/Address.h"
#include "lldb/Core/PluginManager.h"
#include "lldb/Symbol/UnwindPlan.h"
#include "lldb/Utility/ArchSpec.h"
#include "lldb/Utility/ConstString.h"
#include "lldb/Utility/RegisterValue.h"
#include "lldb/Utility/Stream.h"
#include "llvm/Support/CheckedArithmetic.h"
#include "Plugins/Process/Utility/ARMDefines.h"
#include "Plugins/Process/Utility/ARMUtils.h"
#include "Plugins/Process/Utility/lldb-arm64-register-enums.h"
#include <cstdlib>
#define GPR_OFFSET(idx) ((idx)*8)
#define GPR_OFFSET_NAME(reg) 0
#define FPU_OFFSET(idx) ((idx)*16)
#define FPU_OFFSET_NAME(reg) 0
#define EXC_OFFSET_NAME(reg) 0
#define DBG_OFFSET_NAME(reg) 0
#define DBG_OFFSET_NAME(reg) 0
#define DEFINE_DBG(re, y) \
"na", nullptr, 8, 0, lldb::eEncodingUint, lldb::eFormatHex, \
{LLDB_INVALID_REGNUM, LLDB_INVALID_REGNUM, LLDB_INVALID_REGNUM, \
LLDB_INVALID_REGNUM, LLDB_INVALID_REGNUM}, \
nullptr, nullptr, nullptr, 0
#define DECLARE_REGISTER_INFOS_ARM64_STRUCT
#include "Plugins/Process/Utility/RegisterInfos_arm64.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/MathExtras.h"
#include "Plugins/Process/Utility/InstructionUtils.h"
using namespace lldb;
using namespace lldb_private;
LLDB_PLUGIN_DEFINE_ADV(EmulateInstructionARM64, InstructionARM64)
static bool LLDBTableGetRegisterInfo(uint32_t reg_num, RegisterInfo &reg_info) {
if (reg_num >= llvm::array_lengthof(g_register_infos_arm64_le))
return false;
reg_info = g_register_infos_arm64_le[reg_num];
return true;
}
#define No_VFP 0
#define VFPv1 (1u << 1)
#define VFPv2 (1u << 2)
#define VFPv3 (1u << 3)
#define AdvancedSIMD (1u << 4)
#define VFPv1_ABOVE (VFPv1 | VFPv2 | VFPv3 | AdvancedSIMD)
#define VFPv2_ABOVE (VFPv2 | VFPv3 | AdvancedSIMD)
#define VFPv2v3 (VFPv2 | VFPv3)
#define UInt(x) ((uint64_t)x)
#define SInt(x) ((int64_t)x)
#define bit bool
#define boolean bool
#define integer int64_t
static inline bool IsZero(uint64_t x) { return x == 0; }
static inline uint64_t NOT(uint64_t x) { return ~x; }
// LSL()
// =====
static inline uint64_t LSL(uint64_t x, integer shift) {
if (shift == 0)
return x;
return x << shift;
}
// ConstrainUnpredictable()
// ========================
EmulateInstructionARM64::ConstraintType
ConstrainUnpredictable(EmulateInstructionARM64::Unpredictable which) {
EmulateInstructionARM64::ConstraintType result =
EmulateInstructionARM64::Constraint_UNKNOWN;
switch (which) {
case EmulateInstructionARM64::Unpredictable_WBOVERLAP:
case EmulateInstructionARM64::Unpredictable_LDPOVERLAP:
// TODO: don't know what to really do here? Pseudo code says:
// set result to one of above Constraint behaviours or UNDEFINED
break;
}
return result;
}
//
// EmulateInstructionARM implementation
//
void EmulateInstructionARM64::Initialize() {
PluginManager::RegisterPlugin(GetPluginNameStatic(),
GetPluginDescriptionStatic(), CreateInstance);
}
void EmulateInstructionARM64::Terminate() {
PluginManager::UnregisterPlugin(CreateInstance);
}
ConstString EmulateInstructionARM64::GetPluginNameStatic() {
ConstString g_plugin_name("lldb.emulate-instruction.arm64");
return g_plugin_name;
}
lldb_private::ConstString EmulateInstructionARM64::GetPluginName() {
static ConstString g_plugin_name("EmulateInstructionARM64");
return g_plugin_name;
}
const char *EmulateInstructionARM64::GetPluginDescriptionStatic() {
return "Emulate instructions for the ARM64 architecture.";
}
EmulateInstruction *
EmulateInstructionARM64::CreateInstance(const ArchSpec &arch,
InstructionType inst_type) {
if (EmulateInstructionARM64::SupportsEmulatingInstructionsOfTypeStatic(
inst_type)) {
if (arch.GetTriple().getArch() == llvm::Triple::aarch64 ||
arch.GetTriple().getArch() == llvm::Triple::aarch64_32) {
return new EmulateInstructionARM64(arch);
}
}
return nullptr;
}
bool EmulateInstructionARM64::SetTargetTriple(const ArchSpec &arch) {
if (arch.GetTriple().getArch() == llvm::Triple::arm)
return true;
else if (arch.GetTriple().getArch() == llvm::Triple::thumb)
return true;
return false;
}
bool EmulateInstructionARM64::GetRegisterInfo(RegisterKind reg_kind,
uint32_t reg_num,
RegisterInfo &reg_info) {
if (reg_kind == eRegisterKindGeneric) {
switch (reg_num) {
case LLDB_REGNUM_GENERIC_PC:
reg_kind = eRegisterKindLLDB;
reg_num = gpr_pc_arm64;
break;
case LLDB_REGNUM_GENERIC_SP:
reg_kind = eRegisterKindLLDB;
reg_num = gpr_sp_arm64;
break;
case LLDB_REGNUM_GENERIC_FP:
reg_kind = eRegisterKindLLDB;
reg_num = gpr_fp_arm64;
break;
case LLDB_REGNUM_GENERIC_RA:
reg_kind = eRegisterKindLLDB;
reg_num = gpr_lr_arm64;
break;
case LLDB_REGNUM_GENERIC_FLAGS:
reg_kind = eRegisterKindLLDB;
reg_num = gpr_cpsr_arm64;
break;
default:
return false;
}
}
if (reg_kind == eRegisterKindLLDB)
return LLDBTableGetRegisterInfo(reg_num, reg_info);
return false;
}
EmulateInstructionARM64::Opcode *
EmulateInstructionARM64::GetOpcodeForInstruction(const uint32_t opcode) {
static EmulateInstructionARM64::Opcode g_opcodes[] = {
// Prologue instructions
// push register(s)
{0xff000000, 0xd1000000, No_VFP,
&EmulateInstructionARM64::EmulateADDSUBImm,
"SUB <Xd|SP>, <Xn|SP>, #<imm> {, <shift>}"},
{0xff000000, 0xf1000000, No_VFP,
&EmulateInstructionARM64::EmulateADDSUBImm,
"SUBS <Xd>, <Xn|SP>, #<imm> {, <shift>}"},
{0xff000000, 0x91000000, No_VFP,
&EmulateInstructionARM64::EmulateADDSUBImm,
"ADD <Xd|SP>, <Xn|SP>, #<imm> {, <shift>}"},
{0xff000000, 0xb1000000, No_VFP,
&EmulateInstructionARM64::EmulateADDSUBImm,
"ADDS <Xd>, <Xn|SP>, #<imm> {, <shift>}"},
{0xff000000, 0x51000000, No_VFP,
&EmulateInstructionARM64::EmulateADDSUBImm,
"SUB <Wd|WSP>, <Wn|WSP>, #<imm> {, <shift>}"},
{0xff000000, 0x71000000, No_VFP,
&EmulateInstructionARM64::EmulateADDSUBImm,
"SUBS <Wd>, <Wn|WSP>, #<imm> {, <shift>}"},
{0xff000000, 0x11000000, No_VFP,
&EmulateInstructionARM64::EmulateADDSUBImm,
"ADD <Wd|WSP>, <Wn|WSP>, #<imm> {, <shift>}"},
{0xff000000, 0x31000000, No_VFP,
&EmulateInstructionARM64::EmulateADDSUBImm,
"ADDS <Wd>, <Wn|WSP>, #<imm> {, <shift>}"},
{0xffc00000, 0x29000000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_OFF>,
"STP <Wt>, <Wt2>, [<Xn|SP>{, #<imm>}]"},
{0xffc00000, 0xa9000000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_OFF>,
"STP <Xt>, <Xt2>, [<Xn|SP>{, #<imm>}]"},
{0xffc00000, 0x2d000000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_OFF>,
"STP <St>, <St2>, [<Xn|SP>{, #<imm>}]"},
{0xffc00000, 0x6d000000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_OFF>,
"STP <Dt>, <Dt2>, [<Xn|SP>{, #<imm>}]"},
{0xffc00000, 0xad000000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_OFF>,
"STP <Qt>, <Qt2>, [<Xn|SP>{, #<imm>}]"},
{0xffc00000, 0x29800000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_PRE>,
"STP <Wt>, <Wt2>, [<Xn|SP>, #<imm>]!"},
{0xffc00000, 0xa9800000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_PRE>,
"STP <Xt>, <Xt2>, [<Xn|SP>, #<imm>]!"},
{0xffc00000, 0x2d800000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_PRE>,
"STP <St>, <St2>, [<Xn|SP>, #<imm>]!"},
{0xffc00000, 0x6d800000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_PRE>,
"STP <Dt>, <Dt2>, [<Xn|SP>, #<imm>]!"},
{0xffc00000, 0xad800000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_PRE>,
"STP <Qt>, <Qt2>, [<Xn|SP>, #<imm>]!"},
{0xffc00000, 0x28800000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_POST>,
"STP <Wt>, <Wt2>, [<Xn|SP>, #<imm>]!"},
{0xffc00000, 0xa8800000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_POST>,
"STP <Xt>, <Xt2>, [<Xn|SP>, #<imm>]!"},
{0xffc00000, 0x2c800000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_POST>,
"STP <St>, <St2>, [<Xn|SP>, #<imm>]!"},
{0xffc00000, 0x6c800000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_POST>,
"STP <Dt>, <Dt2>, [<Xn|SP>, #<imm>]!"},
{0xffc00000, 0xac800000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_POST>,
"STP <Qt>, <Qt2>, [<Xn|SP>, #<imm>]!"},
{0xffc00000, 0x29400000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_OFF>,
"LDP <Wt>, <Wt2>, [<Xn|SP>{, #<imm>}]"},
{0xffc00000, 0xa9400000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_OFF>,
"LDP <Xt>, <Xt2>, [<Xn|SP>{, #<imm>}]"},
{0xffc00000, 0x2d400000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_OFF>,
"LDP <St>, <St2>, [<Xn|SP>{, #<imm>}]"},
{0xffc00000, 0x6d400000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_OFF>,
"LDP <Dt>, <Dt2>, [<Xn|SP>{, #<imm>}]"},
{0xffc00000, 0xad400000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_OFF>,
"LDP <Qt>, <Qt2>, [<Xn|SP>{, #<imm>}]"},
{0xffc00000, 0x29c00000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_PRE>,
"LDP <Wt>, <Wt2>, [<Xn|SP>, #<imm>]!"},
{0xffc00000, 0xa9c00000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_PRE>,
"LDP <Xt>, <Xt2>, [<Xn|SP>, #<imm>]!"},
{0xffc00000, 0x2dc00000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_PRE>,
"LDP <St>, <St2>, [<Xn|SP>, #<imm>]!"},
{0xffc00000, 0x6dc00000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_PRE>,
"LDP <Dt>, <Dt2>, [<Xn|SP>, #<imm>]!"},
{0xffc00000, 0xadc00000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_PRE>,
"LDP <Qt>, <Qt2>, [<Xn|SP>, #<imm>]!"},
{0xffc00000, 0x28c00000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_POST>,
"LDP <Wt>, <Wt2>, [<Xn|SP>, #<imm>]!"},
{0xffc00000, 0xa8c00000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_POST>,
"LDP <Xt>, <Xt2>, [<Xn|SP>, #<imm>]!"},
{0xffc00000, 0x2cc00000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_POST>,
"LDP <St>, <St2>, [<Xn|SP>, #<imm>]!"},
{0xffc00000, 0x6cc00000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_POST>,
"LDP <Dt>, <Dt2>, [<Xn|SP>, #<imm>]!"},
{0xffc00000, 0xacc00000, No_VFP,
&EmulateInstructionARM64::EmulateLDPSTP<AddrMode_POST>,
"LDP <Qt>, <Qt2>, [<Xn|SP>, #<imm>]!"},
{0xffe00c00, 0xb8000400, No_VFP,
&EmulateInstructionARM64::EmulateLDRSTRImm<AddrMode_POST>,
"STR <Wt>, [<Xn|SP>], #<simm>"},
{0xffe00c00, 0xf8000400, No_VFP,
&EmulateInstructionARM64::EmulateLDRSTRImm<AddrMode_POST>,
"STR <Xt>, [<Xn|SP>], #<simm>"},
{0xffe00c00, 0xb8000c00, No_VFP,
&EmulateInstructionARM64::EmulateLDRSTRImm<AddrMode_PRE>,
"STR <Wt>, [<Xn|SP>, #<simm>]!"},
{0xffe00c00, 0xf8000c00, No_VFP,
&EmulateInstructionARM64::EmulateLDRSTRImm<AddrMode_PRE>,
"STR <Xt>, [<Xn|SP>, #<simm>]!"},
{0xffc00000, 0xb9000000, No_VFP,
&EmulateInstructionARM64::EmulateLDRSTRImm<AddrMode_OFF>,
"STR <Wt>, [<Xn|SP>{, #<pimm>}]"},
{0xffc00000, 0xf9000000, No_VFP,
&EmulateInstructionARM64::EmulateLDRSTRImm<AddrMode_OFF>,
"STR <Xt>, [<Xn|SP>{, #<pimm>}]"},
{0xffe00c00, 0xb8400400, No_VFP,
&EmulateInstructionARM64::EmulateLDRSTRImm<AddrMode_POST>,
"LDR <Wt>, [<Xn|SP>], #<simm>"},
{0xffe00c00, 0xf8400400, No_VFP,
&EmulateInstructionARM64::EmulateLDRSTRImm<AddrMode_POST>,
"LDR <Xt>, [<Xn|SP>], #<simm>"},
{0xffe00c00, 0xb8400c00, No_VFP,
&EmulateInstructionARM64::EmulateLDRSTRImm<AddrMode_PRE>,
"LDR <Wt>, [<Xn|SP>, #<simm>]!"},
{0xffe00c00, 0xf8400c00, No_VFP,
&EmulateInstructionARM64::EmulateLDRSTRImm<AddrMode_PRE>,
"LDR <Xt>, [<Xn|SP>, #<simm>]!"},
{0xffc00000, 0xb9400000, No_VFP,
&EmulateInstructionARM64::EmulateLDRSTRImm<AddrMode_OFF>,
"LDR <Wt>, [<Xn|SP>{, #<pimm>}]"},
{0xffc00000, 0xf9400000, No_VFP,
&EmulateInstructionARM64::EmulateLDRSTRImm<AddrMode_OFF>,
"LDR <Xt>, [<Xn|SP>{, #<pimm>}]"},
{0xfc000000, 0x14000000, No_VFP, &EmulateInstructionARM64::EmulateB,
"B <label>"},
{0xff000010, 0x54000000, No_VFP, &EmulateInstructionARM64::EmulateBcond,
"B.<cond> <label>"},
{0x7f000000, 0x34000000, No_VFP, &EmulateInstructionARM64::EmulateCBZ,
"CBZ <Wt>, <label>"},
{0x7f000000, 0x35000000, No_VFP, &EmulateInstructionARM64::EmulateCBZ,
"CBNZ <Wt>, <label>"},
{0x7f000000, 0x36000000, No_VFP, &EmulateInstructionARM64::EmulateTBZ,
"TBZ <R><t>, #<imm>, <label>"},
{0x7f000000, 0x37000000, No_VFP, &EmulateInstructionARM64::EmulateTBZ,
"TBNZ <R><t>, #<imm>, <label>"},
};
static const size_t k_num_arm_opcodes = llvm::array_lengthof(g_opcodes);
for (size_t i = 0; i < k_num_arm_opcodes; ++i) {
if ((g_opcodes[i].mask & opcode) == g_opcodes[i].value)
return &g_opcodes[i];
}
return nullptr;
}
bool EmulateInstructionARM64::ReadInstruction() {
bool success = false;
m_addr = ReadRegisterUnsigned(eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC,
LLDB_INVALID_ADDRESS, &success);
if (success) {
Context read_inst_context;
read_inst_context.type = eContextReadOpcode;
read_inst_context.SetNoArgs();
m_opcode.SetOpcode32(
ReadMemoryUnsigned(read_inst_context, m_addr, 4, 0, &success),
GetByteOrder());
}
if (!success)
m_addr = LLDB_INVALID_ADDRESS;
return success;
}
bool EmulateInstructionARM64::EvaluateInstruction(uint32_t evaluate_options) {
const uint32_t opcode = m_opcode.GetOpcode32();
Opcode *opcode_data = GetOpcodeForInstruction(opcode);
if (opcode_data == nullptr)
return false;
const bool auto_advance_pc =
evaluate_options & eEmulateInstructionOptionAutoAdvancePC;
m_ignore_conditions =
evaluate_options & eEmulateInstructionOptionIgnoreConditions;
bool success = false;
// Only return false if we are unable to read the CPSR if we care about
// conditions
if (!success && !m_ignore_conditions)
return false;
uint32_t orig_pc_value = 0;
if (auto_advance_pc) {
orig_pc_value =
ReadRegisterUnsigned(eRegisterKindLLDB, gpr_pc_arm64, 0, &success);
if (!success)
return false;
}
// Call the Emulate... function.
success = (this->*opcode_data->callback)(opcode);
if (!success)
return false;
if (auto_advance_pc) {
uint32_t new_pc_value =
ReadRegisterUnsigned(eRegisterKindLLDB, gpr_pc_arm64, 0, &success);
if (!success)
return false;
if (new_pc_value == orig_pc_value) {
EmulateInstruction::Context context;
context.type = eContextAdvancePC;
context.SetNoArgs();
if (!WriteRegisterUnsigned(context, eRegisterKindLLDB, gpr_pc_arm64,
orig_pc_value + 4))
return false;
}
}
return true;
}
bool EmulateInstructionARM64::CreateFunctionEntryUnwind(
UnwindPlan &unwind_plan) {
unwind_plan.Clear();
unwind_plan.SetRegisterKind(eRegisterKindLLDB);
UnwindPlan::RowSP row(new UnwindPlan::Row);
// Our previous Call Frame Address is the stack pointer
row->GetCFAValue().SetIsRegisterPlusOffset(gpr_sp_arm64, 0);
unwind_plan.AppendRow(row);
unwind_plan.SetSourceName("EmulateInstructionARM64");
unwind_plan.SetSourcedFromCompiler(eLazyBoolNo);
unwind_plan.SetUnwindPlanValidAtAllInstructions(eLazyBoolYes);
unwind_plan.SetUnwindPlanForSignalTrap(eLazyBoolNo);
unwind_plan.SetReturnAddressRegister(gpr_lr_arm64);
return true;
}
uint32_t EmulateInstructionARM64::GetFramePointerRegisterNumber() const {
if (m_arch.GetTriple().isAndroid())
return LLDB_INVALID_REGNUM; // Don't use frame pointer on android
return gpr_fp_arm64;
}
bool EmulateInstructionARM64::UsingAArch32() {
bool aarch32 = m_opcode_pstate.RW == 1;
// if !HaveAnyAArch32() then assert !aarch32;
// if HighestELUsingAArch32() then assert aarch32;
return aarch32;
}
bool EmulateInstructionARM64::BranchTo(const Context &context, uint32_t N,
addr_t target) {
#if 0
// Set program counter to a new address, with a branch reason hint for
// possible use by hardware fetching the next instruction.
BranchTo(bits(N) target, BranchType branch_type)
Hint_Branch(branch_type);
if N == 32 then
assert UsingAArch32();
_PC = ZeroExtend(target);
else
assert N == 64 && !UsingAArch32();
// Remove the tag bits from a tagged target
case PSTATE.EL of
when EL0, EL1
if target<55> == '1' && TCR_EL1.TBI1 == '1' then
target<63:56> = '11111111';
if target<55> == '0' && TCR_EL1.TBI0 == '1' then
target<63:56> = '00000000';
when EL2
if TCR_EL2.TBI == '1' then
target<63:56> = '00000000';
when EL3
if TCR_EL3.TBI == '1' then
target<63:56> = '00000000';
_PC = target<63:0>;
return;
#endif
addr_t addr;
// Hint_Branch(branch_type);
if (N == 32) {
if (!UsingAArch32())
return false;
addr = target;
} else if (N == 64) {
if (UsingAArch32())
return false;
// TODO: Remove the tag bits from a tagged target
addr = target;
} else
return false;
return WriteRegisterUnsigned(context, eRegisterKindGeneric,
LLDB_REGNUM_GENERIC_PC, addr);
}
bool EmulateInstructionARM64::ConditionHolds(const uint32_t cond) {
// If we are ignoring conditions, then always return true. this allows us to
// iterate over disassembly code and still emulate an instruction even if we
// don't have all the right bits set in the CPSR register...
if (m_ignore_conditions)
return true;
bool result = false;
switch (UnsignedBits(cond, 3, 1)) {
case 0:
result = (m_opcode_pstate.Z == 1);
break;
case 1:
result = (m_opcode_pstate.C == 1);
break;
case 2:
result = (m_opcode_pstate.N == 1);
break;
case 3:
result = (m_opcode_pstate.V == 1);
break;
case 4:
result = (m_opcode_pstate.C == 1 && m_opcode_pstate.Z == 0);
break;
case 5:
result = (m_opcode_pstate.N == m_opcode_pstate.V);
break;
case 6:
result = (m_opcode_pstate.N == m_opcode_pstate.V && m_opcode_pstate.Z == 0);
break;
case 7:
// Always execute (cond == 0b1110, or the special 0b1111 which gives
// opcodes different meanings, but always means execution happens.
return true;
}
if (cond & 1)
result = !result;
return result;
}
uint64_t EmulateInstructionARM64::
AddWithCarry(uint32_t N, uint64_t x, uint64_t y, bit carry_in,
EmulateInstructionARM64::ProcState &proc_state) {
uint64_t unsigned_sum = UInt(x) + UInt(y) + UInt(carry_in);
llvm::Optional<int64_t> signed_sum = llvm::checkedAdd(SInt(x), SInt(y));
bool overflow = !signed_sum;
if (!overflow)
overflow |= !llvm::checkedAdd(*signed_sum, SInt(carry_in));
uint64_t result = unsigned_sum;
if (N < 64)
result = Bits64(result, N - 1, 0);
proc_state.N = Bit64(result, N - 1);
proc_state.Z = IsZero(result);
proc_state.C = UInt(result) != unsigned_sum;
proc_state.V = overflow;
return result;
}
bool EmulateInstructionARM64::EmulateADDSUBImm(const uint32_t opcode) {
// integer d = UInt(Rd);
// integer n = UInt(Rn);
// integer datasize = if sf == 1 then 64 else 32;
// boolean sub_op = (op == 1);
// boolean setflags = (S == 1);
// bits(datasize) imm;
//
// case shift of
// when '00' imm = ZeroExtend(imm12, datasize);
// when '01' imm = ZeroExtend(imm12 : Zeros(12), datasize);
// when '1x' UNDEFINED;
//
//
// bits(datasize) result;
// bits(datasize) operand1 = if n == 31 then SP[] else X[n];
// bits(datasize) operand2 = imm;
// bits(4) nzcv;
// bit carry_in;
//
// if sub_op then
// operand2 = NOT(operand2);
// carry_in = 1;
// else
// carry_in = 0;
//
// (result, nzcv) = AddWithCarry(operand1, operand2, carry_in);
//
// if setflags then
// PSTATE.NZCV = nzcv;
//
// if d == 31 && !setflags then
// SP[] = result;
// else
// X[d] = result;
const uint32_t sf = Bit32(opcode, 31);
const uint32_t op = Bit32(opcode, 30);
const uint32_t S = Bit32(opcode, 29);
const uint32_t shift = Bits32(opcode, 23, 22);
const uint32_t imm12 = Bits32(opcode, 21, 10);
const uint32_t Rn = Bits32(opcode, 9, 5);
const uint32_t Rd = Bits32(opcode, 4, 0);
bool success = false;
const uint32_t d = UInt(Rd);
const uint32_t n = UInt(Rn);
const uint32_t datasize = (sf == 1) ? 64 : 32;
boolean sub_op = op == 1;
boolean setflags = S == 1;
uint64_t imm;
switch (shift) {
case 0:
imm = imm12;
break;
case 1:
imm = imm12 << 12;
break;
default:
return false; // UNDEFINED;
}
uint64_t result;
uint64_t operand1 =
ReadRegisterUnsigned(eRegisterKindLLDB, gpr_x0_arm64 + n, 0, &success);
uint64_t operand2 = imm;
bit carry_in;
if (sub_op) {
operand2 = NOT(operand2);
carry_in = true;
imm = -imm; // For the Register plug offset context below
} else {
carry_in = false;
}
ProcState proc_state;
result = AddWithCarry(datasize, operand1, operand2, carry_in, proc_state);
if (setflags) {
m_emulated_pstate.N = proc_state.N;
m_emulated_pstate.Z = proc_state.Z;
m_emulated_pstate.C = proc_state.C;
m_emulated_pstate.V = proc_state.V;
}
Context context;
RegisterInfo reg_info_Rn;
if (GetRegisterInfo(eRegisterKindLLDB, n, reg_info_Rn))
context.SetRegisterPlusOffset(reg_info_Rn, imm);
if (n == GetFramePointerRegisterNumber() && d == gpr_sp_arm64 && !setflags) {
// 'mov sp, fp' - common epilogue instruction, CFA is now in terms of the
// stack pointer, instead of frame pointer.
context.type = EmulateInstruction::eContextRestoreStackPointer;
} else if ((n == gpr_sp_arm64 || n == GetFramePointerRegisterNumber()) &&
d == gpr_sp_arm64 && !setflags) {
context.type = EmulateInstruction::eContextAdjustStackPointer;
} else if (d == GetFramePointerRegisterNumber() && n == gpr_sp_arm64 &&
!setflags) {
context.type = EmulateInstruction::eContextSetFramePointer;
} else {
context.type = EmulateInstruction::eContextImmediate;
}
// If setflags && d == gpr_sp_arm64 then d = WZR/XZR. See CMN, CMP
if (!setflags || d != gpr_sp_arm64)
WriteRegisterUnsigned(context, eRegisterKindLLDB, gpr_x0_arm64 + d, result);
return false;
}
template <EmulateInstructionARM64::AddrMode a_mode>
bool EmulateInstructionARM64::EmulateLDPSTP(const uint32_t opcode) {
uint32_t opc = Bits32(opcode, 31, 30);
uint32_t V = Bit32(opcode, 26);
uint32_t L = Bit32(opcode, 22);
uint32_t imm7 = Bits32(opcode, 21, 15);
uint32_t Rt2 = Bits32(opcode, 14, 10);
uint32_t Rn = Bits32(opcode, 9, 5);
uint32_t Rt = Bits32(opcode, 4, 0);
integer n = UInt(Rn);
integer t = UInt(Rt);
integer t2 = UInt(Rt2);
uint64_t idx;
MemOp memop = L == 1 ? MemOp_LOAD : MemOp_STORE;
boolean vector = (V == 1);
// AccType acctype = AccType_NORMAL;
boolean is_signed = false;
boolean wback = a_mode != AddrMode_OFF;
boolean wb_unknown = false;
boolean rt_unknown = false;
integer scale;
integer size;
if (opc == 3)
return false; // UNDEFINED
if (vector) {
scale = 2 + UInt(opc);
} else {
scale = (opc & 2) ? 3 : 2;
is_signed = (opc & 1) != 0;
if (is_signed && memop == MemOp_STORE)
return false; // UNDEFINED
}
if (!vector && wback && ((t == n) || (t2 == n))) {
switch (ConstrainUnpredictable(Unpredictable_WBOVERLAP)) {
case Constraint_UNKNOWN:
wb_unknown = true; // writeback is UNKNOWN
break;
case Constraint_SUPPRESSWB:
wback = false; // writeback is suppressed
break;
case Constraint_NOP:
memop = MemOp_NOP; // do nothing
wback = false;
break;
case Constraint_NONE:
break;
}
}
if (memop == MemOp_LOAD && t == t2) {
switch (ConstrainUnpredictable(Unpredictable_LDPOVERLAP)) {
case Constraint_UNKNOWN:
rt_unknown = true; // result is UNKNOWN
break;
case Constraint_NOP:
memop = MemOp_NOP; // do nothing
wback = false;
break;
default:
break;
}
}
idx = LSL(llvm::SignExtend64<7>(imm7), scale);
size = (integer)1 << scale;
uint64_t datasize = size * 8;
uint64_t address;
uint64_t wb_address;
RegisterValue data_Rt;
RegisterValue data_Rt2;
RegisterInfo reg_info_base;
RegisterInfo reg_info_Rt;
RegisterInfo reg_info_Rt2;
if (!GetRegisterInfo(eRegisterKindLLDB, gpr_x0_arm64 + n, reg_info_base))
return false;
if (vector) {
if (!GetRegisterInfo(eRegisterKindLLDB, fpu_d0_arm64 + t, reg_info_Rt))
return false;
if (!GetRegisterInfo(eRegisterKindLLDB, fpu_d0_arm64 + t2, reg_info_Rt2))
return false;
} else {
if (!GetRegisterInfo(eRegisterKindLLDB, gpr_x0_arm64 + t, reg_info_Rt))
return false;
if (!GetRegisterInfo(eRegisterKindLLDB, gpr_x0_arm64 + t2, reg_info_Rt2))
return false;
}
bool success = false;
if (n == 31) {
// CheckSPAlignment();
address =
ReadRegisterUnsigned(eRegisterKindLLDB, gpr_sp_arm64, 0, &success);
} else
address =
ReadRegisterUnsigned(eRegisterKindLLDB, gpr_x0_arm64 + n, 0, &success);
wb_address = address + idx;
if (a_mode != AddrMode_POST)
address = wb_address;
Context context_t;
Context context_t2;
uint8_t buffer[RegisterValue::kMaxRegisterByteSize];
Status error;
switch (memop) {
case MemOp_STORE: {
if (n == 31 || n == GetFramePointerRegisterNumber()) // if this store is
// based off of the sp
// or fp register
{
context_t.type = eContextPushRegisterOnStack;
context_t2.type = eContextPushRegisterOnStack;
} else {
context_t.type = eContextRegisterStore;
context_t2.type = eContextRegisterStore;
}
context_t.SetRegisterToRegisterPlusOffset(reg_info_Rt, reg_info_base, 0);
context_t2.SetRegisterToRegisterPlusOffset(reg_info_Rt2, reg_info_base,
size);
if (!ReadRegister(&reg_info_Rt, data_Rt))
return false;
if (data_Rt.GetAsMemoryData(&reg_info_Rt, buffer, reg_info_Rt.byte_size,
eByteOrderLittle, error) == 0)
return false;
if (!WriteMemory(context_t, address + 0, buffer, reg_info_Rt.byte_size))
return false;
if (!ReadRegister(&reg_info_Rt2, data_Rt2))
return false;
if (data_Rt2.GetAsMemoryData(&reg_info_Rt2, buffer, reg_info_Rt2.byte_size,
eByteOrderLittle, error) == 0)
return false;
if (!WriteMemory(context_t2, address + size, buffer,
reg_info_Rt2.byte_size))
return false;
} break;
case MemOp_LOAD: {
if (n == 31 || n == GetFramePointerRegisterNumber()) // if this load is
// based off of the sp
// or fp register
{
context_t.type = eContextPopRegisterOffStack;
context_t2.type = eContextPopRegisterOffStack;
} else {
context_t.type = eContextRegisterLoad;
context_t2.type = eContextRegisterLoad;
}
context_t.SetAddress(address);
context_t2.SetAddress(address + size);
if (rt_unknown)
memset(buffer, 'U', reg_info_Rt.byte_size);
else {
if (!ReadMemory(context_t, address, buffer, reg_info_Rt.byte_size))
return false;
}
if (data_Rt.SetFromMemoryData(&reg_info_Rt, buffer, reg_info_Rt.byte_size,
eByteOrderLittle, error) == 0)
return false;
if (!vector && is_signed && !data_Rt.SignExtend(datasize))
return false;
if (!WriteRegister(context_t, &reg_info_Rt, data_Rt))
return false;
if (!rt_unknown) {
if (!ReadMemory(context_t2, address + size, buffer,
reg_info_Rt2.byte_size))
return false;
}
if (data_Rt2.SetFromMemoryData(&reg_info_Rt2, buffer,
reg_info_Rt2.byte_size, eByteOrderLittle,
error) == 0)
return false;
if (!vector && is_signed && !data_Rt2.SignExtend(datasize))
return false;
if (!WriteRegister(context_t2, &reg_info_Rt2, data_Rt2))
return false;
} break;
default:
break;
}
if (wback) {
if (wb_unknown)
wb_address = LLDB_INVALID_ADDRESS;
Context context;
context.SetImmediateSigned(idx);
if (n == 31)
context.type = eContextAdjustStackPointer;
else
context.type = eContextAdjustBaseRegister;
WriteRegisterUnsigned(context, &reg_info_base, wb_address);
}
return true;
}
template <EmulateInstructionARM64::AddrMode a_mode>
bool EmulateInstructionARM64::EmulateLDRSTRImm(const uint32_t opcode) {
uint32_t size = Bits32(opcode, 31, 30);
uint32_t opc = Bits32(opcode, 23, 22);
uint32_t n = Bits32(opcode, 9, 5);
uint32_t t = Bits32(opcode, 4, 0);
bool wback;
bool postindex;
uint64_t offset;
switch (a_mode) {
case AddrMode_POST:
wback = true;
postindex = true;
offset = llvm::SignExtend64<9>(Bits32(opcode, 20, 12));
break;
case AddrMode_PRE:
wback = true;
postindex = false;
offset = llvm::SignExtend64<9>(Bits32(opcode, 20, 12));
break;
case AddrMode_OFF:
wback = false;
postindex = false;
offset = LSL(Bits32(opcode, 21, 10), size);
break;
}
MemOp memop;
if (Bit32(opc, 1) == 0) {
memop = Bit32(opc, 0) == 1 ? MemOp_LOAD : MemOp_STORE;
} else {
memop = MemOp_LOAD;
if (size == 2 && Bit32(opc, 0) == 1)
return false;
}
Status error;
bool success = false;
uint64_t address;
uint8_t buffer[RegisterValue::kMaxRegisterByteSize];
RegisterValue data_Rt;
if (n == 31)
address =
ReadRegisterUnsigned(eRegisterKindLLDB, gpr_sp_arm64, 0, &success);
else
address =
ReadRegisterUnsigned(eRegisterKindLLDB, gpr_x0_arm64 + n, 0, &success);
if (!success)
return false;
if (!postindex)
address += offset;
RegisterInfo reg_info_base;
if (!GetRegisterInfo(eRegisterKindLLDB, gpr_x0_arm64 + n, reg_info_base))
return false;
RegisterInfo reg_info_Rt;
if (!GetRegisterInfo(eRegisterKindLLDB, gpr_x0_arm64 + t, reg_info_Rt))
return false;
Context context;
switch (memop) {
case MemOp_STORE:
if (n == 31 || n == GetFramePointerRegisterNumber()) // if this store is
// based off of the sp
// or fp register
context.type = eContextPushRegisterOnStack;
else
context.type = eContextRegisterStore;
context.SetRegisterToRegisterPlusOffset(reg_info_Rt, reg_info_base,
postindex ? 0 : offset);
if (!ReadRegister(&reg_info_Rt, data_Rt))
return false;
if (data_Rt.GetAsMemoryData(&reg_info_Rt, buffer, reg_info_Rt.byte_size,
eByteOrderLittle, error) == 0)
return false;
if (!WriteMemory(context, address, buffer, reg_info_Rt.byte_size))
return false;
break;
case MemOp_LOAD:
if (n == 31 || n == GetFramePointerRegisterNumber()) // if this store is
// based off of the sp
// or fp register
context.type = eContextPopRegisterOffStack;
else
context.type = eContextRegisterLoad;
context.SetAddress(address);
if (!ReadMemory(context, address, buffer, reg_info_Rt.byte_size))
return false;
if (data_Rt.SetFromMemoryData(&reg_info_Rt, buffer, reg_info_Rt.byte_size,
eByteOrderLittle, error) == 0)
return false;
if (!WriteRegister(context, &reg_info_Rt, data_Rt))
return false;
break;
default:
return false;
}
if (wback) {
if (postindex)
address += offset;
if (n == 31)
context.type = eContextAdjustStackPointer;
else
context.type = eContextAdjustBaseRegister;
context.SetImmediateSigned(offset);
if (!WriteRegisterUnsigned(context, &reg_info_base, address))
return false;
}
return true;
}
bool EmulateInstructionARM64::EmulateB(const uint32_t opcode) {
#if 0
// ARM64 pseudo code...
if branch_type == BranchType_CALL then X[30] = PC[] + 4;
BranchTo(PC[] + offset, branch_type);
#endif
bool success = false;
EmulateInstruction::Context context;
context.type = EmulateInstruction::eContextRelativeBranchImmediate;
const uint64_t pc = ReadRegisterUnsigned(eRegisterKindGeneric,
LLDB_REGNUM_GENERIC_PC, 0, &success);
if (!success)
return false;
int64_t offset = llvm::SignExtend64<28>(Bits32(opcode, 25, 0) << 2);
BranchType branch_type = Bit32(opcode, 31) ? BranchType_CALL : BranchType_JMP;
addr_t target = pc + offset;
context.SetImmediateSigned(offset);
switch (branch_type) {
case BranchType_CALL: {
addr_t x30 = pc + 4;
if (!WriteRegisterUnsigned(context, eRegisterKindLLDB, gpr_lr_arm64, x30))
return false;
} break;
case BranchType_JMP:
break;
default:
return false;
}
return BranchTo(context, 64, target);
}
bool EmulateInstructionARM64::EmulateBcond(const uint32_t opcode) {
#if 0
// ARM64 pseudo code...
bits(64) offset = SignExtend(imm19:'00', 64);
bits(4) condition = cond;
if ConditionHolds(condition) then
BranchTo(PC[] + offset, BranchType_JMP);
#endif
if (ConditionHolds(Bits32(opcode, 3, 0))) {
bool success = false;
const uint64_t pc = ReadRegisterUnsigned(
eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC, 0, &success);
if (!success)
return false;
int64_t offset = llvm::SignExtend64<21>(Bits32(opcode, 23, 5) << 2);
addr_t target = pc + offset;
EmulateInstruction::Context context;
context.type = EmulateInstruction::eContextRelativeBranchImmediate;
context.SetImmediateSigned(offset);
if (!BranchTo(context, 64, target))
return false;
}
return true;
}
bool EmulateInstructionARM64::EmulateCBZ(const uint32_t opcode) {
#if 0
integer t = UInt(Rt);
integer datasize = if sf == '1' then 64 else 32;
boolean iszero = (op == '0');
bits(64) offset = SignExtend(imm19:'00', 64);
bits(datasize) operand1 = X[t];
if IsZero(operand1) == iszero then
BranchTo(PC[] + offset, BranchType_JMP);
#endif
bool success = false;
uint32_t t = Bits32(opcode, 4, 0);
bool is_zero = Bit32(opcode, 24) == 0;
int32_t offset = llvm::SignExtend64<21>(Bits32(opcode, 23, 5) << 2);
const uint64_t operand =
ReadRegisterUnsigned(eRegisterKindLLDB, gpr_x0_arm64 + t, 0, &success);
if (!success)
return false;
if (m_ignore_conditions || ((operand == 0) == is_zero)) {
const uint64_t pc = ReadRegisterUnsigned(
eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC, 0, &success);
if (!success)
return false;
EmulateInstruction::Context context;
context.type = EmulateInstruction::eContextRelativeBranchImmediate;
context.SetImmediateSigned(offset);
if (!BranchTo(context, 64, pc + offset))
return false;
}
return true;
}
bool EmulateInstructionARM64::EmulateTBZ(const uint32_t opcode) {
#if 0
integer t = UInt(Rt);
integer datasize = if b5 == '1' then 64 else 32;
integer bit_pos = UInt(b5:b40);
bit bit_val = op;
bits(64) offset = SignExtend(imm14:'00', 64);
#endif
bool success = false;
uint32_t t = Bits32(opcode, 4, 0);
uint32_t bit_pos = (Bit32(opcode, 31) << 6) | (Bits32(opcode, 23, 19));
uint32_t bit_val = Bit32(opcode, 24);
int64_t offset = llvm::SignExtend64<16>(Bits32(opcode, 18, 5) << 2);
const uint64_t operand =
ReadRegisterUnsigned(eRegisterKindLLDB, gpr_x0_arm64 + t, 0, &success);
if (!success)
return false;
if (m_ignore_conditions || Bit32(operand, bit_pos) == bit_val) {
const uint64_t pc = ReadRegisterUnsigned(
eRegisterKindGeneric, LLDB_REGNUM_GENERIC_PC, 0, &success);
if (!success)
return false;
EmulateInstruction::Context context;
context.type = EmulateInstruction::eContextRelativeBranchImmediate;
context.SetImmediateSigned(offset);
if (!BranchTo(context, 64, pc + offset))
return false;
}
return true;
}
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