1 //===-- xray_mips64.cc ------------------------------------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file is a part of XRay, a dynamic runtime instrumentation system. 11 // 12 // Implementation of MIPS64-specific routines. 13 // 14 //===----------------------------------------------------------------------===// 15 #include "sanitizer_common/sanitizer_common.h" 16 #include "xray_defs.h" 17 #include "xray_interface_internal.h" 18 #include <atomic> 19 20 namespace __xray { 21 22 // The machine codes for some instructions used in runtime patching. 23 enum PatchOpcodes : uint32_t { 24 PO_DADDIU = 0x64000000, // daddiu rt, rs, imm 25 PO_SD = 0xFC000000, // sd rt, base(offset) 26 PO_LUI = 0x3C000000, // lui rt, imm 27 PO_ORI = 0x34000000, // ori rt, rs, imm 28 PO_DSLL = 0x00000038, // dsll rd, rt, sa 29 PO_JALR = 0x00000009, // jalr rs 30 PO_LD = 0xDC000000, // ld rt, base(offset) 31 PO_B60 = 0x1000000f, // b #60 32 PO_NOP = 0x0, // nop 33 }; 34 35 enum RegNum : uint32_t { 36 RN_T0 = 0xC, 37 RN_T9 = 0x19, 38 RN_RA = 0x1F, 39 RN_SP = 0x1D, 40 }; 41 42 inline static uint32_t encodeInstruction(uint32_t Opcode, uint32_t Rs, 43 uint32_t Rt, 44 uint32_t Imm) XRAY_NEVER_INSTRUMENT { 45 return (Opcode | Rs << 21 | Rt << 16 | Imm); 46 } 47 48 inline static uint32_t 49 encodeSpecialInstruction(uint32_t Opcode, uint32_t Rs, uint32_t Rt, uint32_t Rd, 50 uint32_t Imm) XRAY_NEVER_INSTRUMENT { 51 return (Rs << 21 | Rt << 16 | Rd << 11 | Imm << 6 | Opcode); 52 } 53 54 inline static bool patchSled(const bool Enable, const uint32_t FuncId, 55 const XRaySledEntry &Sled, 56 void (*TracingHook)()) XRAY_NEVER_INSTRUMENT { 57 // When |Enable| == true, 58 // We replace the following compile-time stub (sled): 59 // 60 // xray_sled_n: 61 // B .tmpN 62 // 15 NOPs (60 bytes) 63 // .tmpN 64 // 65 // With the following runtime patch: 66 // 67 // xray_sled_n (64-bit): 68 // daddiu sp, sp, -16 ;create stack frame 69 // nop 70 // sd ra, 8(sp) ;save return address 71 // sd t9, 0(sp) ;save register t9 72 // lui t9, %highest(__xray_FunctionEntry/Exit) 73 // ori t9, t9, %higher(__xray_FunctionEntry/Exit) 74 // dsll t9, t9, 16 75 // ori t9, t9, %hi(__xray_FunctionEntry/Exit) 76 // dsll t9, t9, 16 77 // ori t9, t9, %lo(__xray_FunctionEntry/Exit) 78 // lui t0, %hi(function_id) 79 // jalr t9 ;call Tracing hook 80 // ori t0, t0, %lo(function_id) ;pass function id (delay slot) 81 // ld t9, 0(sp) ;restore register t9 82 // ld ra, 8(sp) ;restore return address 83 // daddiu sp, sp, 16 ;delete stack frame 84 // 85 // Replacement of the first 4-byte instruction should be the last and atomic 86 // operation, so that the user code which reaches the sled concurrently 87 // either jumps over the whole sled, or executes the whole sled when the 88 // latter is ready. 89 // 90 // When |Enable|==false, we set back the first instruction in the sled to be 91 // B #60 92 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 *reinterpret_cast<uint32_t *>(Sled.Address + 8) = encodeInstruction( 105 PatchOpcodes::PO_SD, RegNum::RN_SP, RegNum::RN_RA, 0x8); 106 *reinterpret_cast<uint32_t *>(Sled.Address + 12) = encodeInstruction( 107 PatchOpcodes::PO_SD, RegNum::RN_SP, RegNum::RN_T9, 0x0); 108 *reinterpret_cast<uint32_t *>(Sled.Address + 16) = encodeInstruction( 109 PatchOpcodes::PO_LUI, 0x0, RegNum::RN_T9, HighestTracingHookAddr); 110 *reinterpret_cast<uint32_t *>(Sled.Address + 20) = 111 encodeInstruction(PatchOpcodes::PO_ORI, RegNum::RN_T9, RegNum::RN_T9, 112 HigherTracingHookAddr); 113 *reinterpret_cast<uint32_t *>(Sled.Address + 24) = encodeSpecialInstruction( 114 PatchOpcodes::PO_DSLL, 0x0, RegNum::RN_T9, RegNum::RN_T9, 0x10); 115 *reinterpret_cast<uint32_t *>(Sled.Address + 28) = encodeInstruction( 116 PatchOpcodes::PO_ORI, RegNum::RN_T9, RegNum::RN_T9, HiTracingHookAddr); 117 *reinterpret_cast<uint32_t *>(Sled.Address + 32) = encodeSpecialInstruction( 118 PatchOpcodes::PO_DSLL, 0x0, RegNum::RN_T9, RegNum::RN_T9, 0x10); 119 *reinterpret_cast<uint32_t *>(Sled.Address + 36) = encodeInstruction( 120 PatchOpcodes::PO_ORI, RegNum::RN_T9, RegNum::RN_T9, LoTracingHookAddr); 121 *reinterpret_cast<uint32_t *>(Sled.Address + 40) = encodeInstruction( 122 PatchOpcodes::PO_LUI, 0x0, RegNum::RN_T0, HiFunctionID); 123 *reinterpret_cast<uint32_t *>(Sled.Address + 44) = encodeSpecialInstruction( 124 PatchOpcodes::PO_JALR, RegNum::RN_T9, 0x0, RegNum::RN_RA, 0X0); 125 *reinterpret_cast<uint32_t *>(Sled.Address + 48) = encodeInstruction( 126 PatchOpcodes::PO_ORI, RegNum::RN_T0, RegNum::RN_T0, LoFunctionID); 127 *reinterpret_cast<uint32_t *>(Sled.Address + 52) = encodeInstruction( 128 PatchOpcodes::PO_LD, RegNum::RN_SP, RegNum::RN_T9, 0x0); 129 *reinterpret_cast<uint32_t *>(Sled.Address + 56) = encodeInstruction( 130 PatchOpcodes::PO_LD, RegNum::RN_SP, RegNum::RN_RA, 0x8); 131 *reinterpret_cast<uint32_t *>(Sled.Address + 60) = encodeInstruction( 132 PatchOpcodes::PO_DADDIU, RegNum::RN_SP, RegNum::RN_SP, 0x10); 133 uint32_t CreateStackSpace = encodeInstruction( 134 PatchOpcodes::PO_DADDIU, RegNum::RN_SP, RegNum::RN_SP, 0xfff0); 135 std::atomic_store_explicit( 136 reinterpret_cast<std::atomic<uint32_t> *>(Sled.Address), 137 CreateStackSpace, std::memory_order_release); 138 } else { 139 std::atomic_store_explicit( 140 reinterpret_cast<std::atomic<uint32_t> *>(Sled.Address), 141 uint32_t(PatchOpcodes::PO_B60), std::memory_order_release); 142 } 143 return true; 144 } 145 146 bool patchFunctionEntry(const bool Enable, const uint32_t FuncId, 147 const XRaySledEntry &Sled, 148 void (*Trampoline)()) XRAY_NEVER_INSTRUMENT { 149 return patchSled(Enable, FuncId, Sled, Trampoline); 150 } 151 152 bool patchFunctionExit(const bool Enable, const uint32_t FuncId, 153 const XRaySledEntry &Sled) XRAY_NEVER_INSTRUMENT { 154 return patchSled(Enable, FuncId, Sled, __xray_FunctionExit); 155 } 156 157 bool patchFunctionTailExit(const bool Enable, const uint32_t FuncId, 158 const XRaySledEntry &Sled) XRAY_NEVER_INSTRUMENT { 159 // FIXME: In the future we'd need to distinguish between non-tail exits and 160 // tail exits for better information preservation. 161 return patchSled(Enable, FuncId, Sled, __xray_FunctionExit); 162 } 163 164 bool patchCustomEvent(const bool Enable, const uint32_t FuncId, 165 const XRaySledEntry &Sled) XRAY_NEVER_INSTRUMENT { 166 // FIXME: Implement in mips64? 167 return false; 168 } 169 170 bool patchTypedEvent(const bool Enable, const uint32_t FuncId, 171 const XRaySledEntry &Sled) XRAY_NEVER_INSTRUMENT { 172 // FIXME: Implement in mips64? 173 return false; 174 } 175 } // namespace __xray 176 177 extern "C" void __xray_ArgLoggerEntry() XRAY_NEVER_INSTRUMENT { 178 // FIXME: this will have to be implemented in the trampoline assembly file 179 } 180