188 lines · cpp
1//===-- xray_mips64.cpp -----------------------------------------*- C++ -*-===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8//9// This file is a part of XRay, a dynamic runtime instrumentation system.10//11// Implementation of MIPS64-specific routines.12//13//===----------------------------------------------------------------------===//14#include "sanitizer_common/sanitizer_common.h"15#include "xray_defs.h"16#include "xray_interface_internal.h"17#include <atomic>18 19namespace __xray {20 21// The machine codes for some instructions used in runtime patching.22enum PatchOpcodes : uint32_t {23 PO_DADDIU = 0x64000000, // daddiu rt, rs, imm24 PO_SD = 0xFC000000, // sd rt, base(offset)25 PO_LUI = 0x3C000000, // lui rt, imm26 PO_ORI = 0x34000000, // ori rt, rs, imm27 PO_DSLL = 0x00000038, // dsll rd, rt, sa28 PO_JALR = 0x00000009, // jalr rs29 PO_LD = 0xDC000000, // ld rt, base(offset)30 PO_B60 = 0x1000000f, // b #6031 PO_NOP = 0x0, // nop32};33 34enum RegNum : uint32_t {35 RN_T0 = 0xC,36 RN_T9 = 0x19,37 RN_RA = 0x1F,38 RN_SP = 0x1D,39};40 41inline static uint32_t encodeInstruction(uint32_t Opcode, uint32_t Rs,42 uint32_t Rt,43 uint32_t Imm) XRAY_NEVER_INSTRUMENT {44 return (Opcode | Rs << 21 | Rt << 16 | Imm);45}46 47inline static uint32_t48encodeSpecialInstruction(uint32_t Opcode, uint32_t Rs, uint32_t Rt, uint32_t Rd,49 uint32_t Imm) XRAY_NEVER_INSTRUMENT {50 return (Rs << 21 | Rt << 16 | Rd << 11 | Imm << 6 | Opcode);51}52 53inline static bool patchSled(const bool Enable, const uint32_t FuncId,54 const XRaySledEntry &Sled,55 void (*TracingHook)()) XRAY_NEVER_INSTRUMENT {56 // When |Enable| == true,57 // We replace the following compile-time stub (sled):58 //59 // xray_sled_n:60 // B .tmpN61 // 15 NOPs (60 bytes)62 // .tmpN63 //64 // With the following runtime patch:65 //66 // xray_sled_n (64-bit):67 // daddiu sp, sp, -16 ;create stack frame68 // nop69 // sd ra, 8(sp) ;save return address70 // sd t9, 0(sp) ;save register t971 // lui t9, %highest(__xray_FunctionEntry/Exit)72 // ori t9, t9, %higher(__xray_FunctionEntry/Exit)73 // dsll t9, t9, 1674 // ori t9, t9, %hi(__xray_FunctionEntry/Exit)75 // dsll t9, t9, 1676 // ori t9, t9, %lo(__xray_FunctionEntry/Exit)77 // lui t0, %hi(function_id)78 // jalr t9 ;call Tracing hook79 // ori t0, t0, %lo(function_id) ;pass function id (delay slot)80 // ld t9, 0(sp) ;restore register t981 // ld ra, 8(sp) ;restore return address82 // daddiu sp, sp, 16 ;delete stack frame83 //84 // Replacement of the first 4-byte instruction should be the last and atomic85 // operation, so that the user code which reaches the sled concurrently86 // either jumps over the whole sled, or executes the whole sled when the87 // latter is ready.88 //89 // When |Enable|==false, we set back the first instruction in the sled to be90 // B #6091 92 uint32_t *Address = reinterpret_cast<uint32_t *>(Sled.address());93 if (Enable) {94 uint32_t LoTracingHookAddr =95 reinterpret_cast<int64_t>(TracingHook) & 0xffff;96 uint32_t HiTracingHookAddr =97 (reinterpret_cast<int64_t>(TracingHook) >> 16) & 0xffff;98 uint32_t HigherTracingHookAddr =99 (reinterpret_cast<int64_t>(TracingHook) >> 32) & 0xffff;100 uint32_t HighestTracingHookAddr =101 (reinterpret_cast<int64_t>(TracingHook) >> 48) & 0xffff;102 uint32_t LoFunctionID = FuncId & 0xffff;103 uint32_t HiFunctionID = (FuncId >> 16) & 0xffff;104 Address[2] = encodeInstruction(PatchOpcodes::PO_SD, RegNum::RN_SP,105 RegNum::RN_RA, 0x8);106 Address[3] = encodeInstruction(PatchOpcodes::PO_SD, RegNum::RN_SP,107 RegNum::RN_T9, 0x0);108 Address[4] = encodeInstruction(PatchOpcodes::PO_LUI, 0x0, RegNum::RN_T9,109 HighestTracingHookAddr);110 Address[5] = encodeInstruction(PatchOpcodes::PO_ORI, RegNum::RN_T9,111 RegNum::RN_T9, HigherTracingHookAddr);112 Address[6] = encodeSpecialInstruction(PatchOpcodes::PO_DSLL, 0x0,113 RegNum::RN_T9, RegNum::RN_T9, 0x10);114 Address[7] = encodeInstruction(PatchOpcodes::PO_ORI, RegNum::RN_T9,115 RegNum::RN_T9, HiTracingHookAddr);116 Address[8] = encodeSpecialInstruction(PatchOpcodes::PO_DSLL, 0x0,117 RegNum::RN_T9, RegNum::RN_T9, 0x10);118 Address[9] = encodeInstruction(PatchOpcodes::PO_ORI, RegNum::RN_T9,119 RegNum::RN_T9, LoTracingHookAddr);120 Address[10] = encodeInstruction(PatchOpcodes::PO_LUI, 0x0, RegNum::RN_T0,121 HiFunctionID);122 Address[11] = encodeSpecialInstruction(PatchOpcodes::PO_JALR, RegNum::RN_T9,123 0x0, RegNum::RN_RA, 0X0);124 Address[12] = encodeInstruction(PatchOpcodes::PO_ORI, RegNum::RN_T0,125 RegNum::RN_T0, LoFunctionID);126 Address[13] = encodeInstruction(PatchOpcodes::PO_LD, RegNum::RN_SP,127 RegNum::RN_T9, 0x0);128 Address[14] = encodeInstruction(PatchOpcodes::PO_LD, RegNum::RN_SP,129 RegNum::RN_RA, 0x8);130 Address[15] = encodeInstruction(PatchOpcodes::PO_DADDIU, RegNum::RN_SP,131 RegNum::RN_SP, 0x10);132 uint32_t CreateStackSpace = encodeInstruction(133 PatchOpcodes::PO_DADDIU, RegNum::RN_SP, RegNum::RN_SP, 0xfff0);134 std::atomic_store_explicit(135 reinterpret_cast<std::atomic<uint32_t> *>(Address), CreateStackSpace,136 std::memory_order_release);137 } else {138 std::atomic_store_explicit(139 reinterpret_cast<std::atomic<uint32_t> *>(Address),140 uint32_t(PatchOpcodes::PO_B60), std::memory_order_release);141 }142 return true;143}144 145bool patchFunctionEntry(const bool Enable, const uint32_t FuncId,146 const XRaySledEntry &Sled,147 const XRayTrampolines &Trampolines,148 bool LogArgs) XRAY_NEVER_INSTRUMENT {149 auto Trampoline =150 LogArgs ? Trampolines.LogArgsTrampoline : Trampolines.EntryTrampoline;151 return patchSled(Enable, FuncId, Sled, Trampoline);152}153 154bool patchFunctionExit(155 const bool Enable, const uint32_t FuncId, const XRaySledEntry &Sled,156 const XRayTrampolines &Trampolines) XRAY_NEVER_INSTRUMENT {157 return patchSled(Enable, FuncId, Sled, Trampolines.ExitTrampoline);158}159 160bool patchFunctionTailExit(161 const bool Enable, const uint32_t FuncId, const XRaySledEntry &Sled,162 const XRayTrampolines &Trampolines) XRAY_NEVER_INSTRUMENT {163 // FIXME: In the future we'd need to distinguish between non-tail exits and164 // tail exits for better information preservation.165 return patchSled(Enable, FuncId, Sled, Trampolines.ExitTrampoline);166}167 168bool patchCustomEvent(const bool Enable, const uint32_t FuncId,169 const XRaySledEntry &Sled) XRAY_NEVER_INSTRUMENT {170 // FIXME: Implement in mips64?171 return false;172}173 174bool patchTypedEvent(const bool Enable, const uint32_t FuncId,175 const XRaySledEntry &Sled) XRAY_NEVER_INSTRUMENT {176 // FIXME: Implement in mips64?177 return false;178}179} // namespace __xray180 181extern "C" void __xray_ArgLoggerEntry() XRAY_NEVER_INSTRUMENT {182 // FIXME: this will have to be implemented in the trampoline assembly file183}184 185extern "C" void __xray_FunctionTailExit() XRAY_NEVER_INSTRUMENT {186 // FIXME: this will have to be implemented in the trampoline assembly file187}188