| //===-------- xray_loongarch64.cpp ------------------------------*- C++ -*-===// |
| // |
| // 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 |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file is a part of XRay, a dynamic runtime instrumentation system. |
| // |
| // Implementation of loongarch-specific routines. |
| // |
| //===----------------------------------------------------------------------===// |
| #include "sanitizer_common/sanitizer_common.h" |
| #include "xray_defs.h" |
| #include "xray_interface_internal.h" |
| #include <atomic> |
| |
| namespace __xray { |
| |
| enum RegNum : uint32_t { |
| RN_RA = 1, |
| RN_SP = 3, |
| RN_T0 = 12, |
| RN_T1 = 13, |
| }; |
| |
| // Encode instructions in the 2RIx format, where the primary formats here |
| // are 2RI12-type and 2RI16-type. |
| static inline uint32_t |
| encodeInstruction2RIx(uint32_t Opcode, uint32_t Rd, uint32_t Rj, |
| uint32_t Imm) XRAY_NEVER_INSTRUMENT { |
| return Opcode | (Imm << 10) | (Rj << 5) | Rd; |
| } |
| |
| // Encode instructions in 1RI20 format, e.g. lu12i.w/lu32i.d. |
| static inline uint32_t |
| encodeInstruction1RI20(uint32_t Opcode, uint32_t Rd, |
| uint32_t Imm) XRAY_NEVER_INSTRUMENT { |
| return Opcode | (Imm << 5) | Rd; |
| } |
| |
| static inline bool patchSled(const bool Enable, const uint32_t FuncId, |
| const XRaySledEntry &Sled, |
| void (*TracingHook)()) XRAY_NEVER_INSTRUMENT { |
| // When |Enable| == true, |
| // We replace the following compile-time stub (sled): |
| // |
| // .Lxray_sled_beginN: |
| // B .Lxray_sled_endN |
| // 11 NOPs (44 bytes) |
| // .Lxray_sled_endN: |
| // |
| // With the following runtime patch: |
| // |
| // xray_sled_n: |
| // addi.d sp, sp, -16 ; create the stack frame |
| // st.d ra, sp, 8 ; save the return address |
| // lu12i.w t0, %abs_hi20(__xray_FunctionEntry/Exit) |
| // ori t0, t0, %abs_lo12(__xray_FunctionEntry/Exit) |
| // lu32i.d t0, %abs64_lo20(__xray_FunctionEntry/Exit) |
| // lu52i.d t0, t0, %abs64_hi12(__xray_FunctionEntry/Exit) |
| // lu12i.w t1, %abs_hi20(function_id) |
| // ori t1, t1, %abs_lo12(function_id) ; pass the function id |
| // jirl ra, t0, 0 ; call the tracing hook |
| // ld.d ra, sp, 8 ; restore the return address |
| // addi.d sp, sp, 16 ; de-allocate the stack frame |
| // |
| // Replacement of the first 4-byte instruction should be the last and atomic |
| // operation, so that the user code which reaches the sled concurrently |
| // either jumps over the whole sled, or executes the whole sled when the |
| // latter is ready. |
| // |
| // When |Enable|==false, we set the first instruction in the sled back to |
| // B #48 |
| |
| uint32_t *Address = reinterpret_cast<uint32_t *>(Sled.address()); |
| if (Enable) { |
| uint32_t LoTracingHookAddr = reinterpret_cast<int64_t>(TracingHook) & 0xfff; |
| uint32_t HiTracingHookAddr = |
| (reinterpret_cast<int64_t>(TracingHook) >> 12) & 0xfffff; |
| uint32_t HigherTracingHookAddr = |
| (reinterpret_cast<int64_t>(TracingHook) >> 32) & 0xfffff; |
| uint32_t HighestTracingHookAddr = |
| (reinterpret_cast<int64_t>(TracingHook) >> 52) & 0xfff; |
| uint32_t LoFunctionID = FuncId & 0xfff; |
| uint32_t HiFunctionID = (FuncId >> 12) & 0xfffff; |
| Address[1] = encodeInstruction2RIx(0x29c00000, RegNum::RN_RA, RegNum::RN_SP, |
| 0x8); // st.d ra, sp, 8 |
| Address[2] = encodeInstruction1RI20( |
| 0x14000000, RegNum::RN_T0, |
| HiTracingHookAddr); // lu12i.w t0, HiTracingHookAddr |
| Address[3] = encodeInstruction2RIx( |
| 0x03800000, RegNum::RN_T0, RegNum::RN_T0, |
| LoTracingHookAddr); // ori t0, t0, LoTracingHookAddr |
| Address[4] = encodeInstruction1RI20( |
| 0x16000000, RegNum::RN_T0, |
| HigherTracingHookAddr); // lu32i.d t0, HigherTracingHookAddr |
| Address[5] = encodeInstruction2RIx( |
| 0x03000000, RegNum::RN_T0, RegNum::RN_T0, |
| HighestTracingHookAddr); // lu52i.d t0, t0, HighestTracingHookAddr |
| Address[6] = |
| encodeInstruction1RI20(0x14000000, RegNum::RN_T1, |
| HiFunctionID); // lu12i.w t1, HiFunctionID |
| Address[7] = |
| encodeInstruction2RIx(0x03800000, RegNum::RN_T1, RegNum::RN_T1, |
| LoFunctionID); // ori t1, t1, LoFunctionID |
| Address[8] = encodeInstruction2RIx(0x4c000000, RegNum::RN_RA, RegNum::RN_T0, |
| 0); // jirl ra, t0, 0 |
| Address[9] = encodeInstruction2RIx(0x28c00000, RegNum::RN_RA, RegNum::RN_SP, |
| 0x8); // ld.d ra, sp, 8 |
| Address[10] = encodeInstruction2RIx( |
| 0x02c00000, RegNum::RN_SP, RegNum::RN_SP, 0x10); // addi.d sp, sp, 16 |
| uint32_t CreateStackSpace = encodeInstruction2RIx( |
| 0x02c00000, RegNum::RN_SP, RegNum::RN_SP, 0xff0); // addi.d sp, sp, -16 |
| std::atomic_store_explicit( |
| reinterpret_cast<std::atomic<uint32_t> *>(Address), CreateStackSpace, |
| std::memory_order_release); |
| } else { |
| std::atomic_store_explicit( |
| reinterpret_cast<std::atomic<uint32_t> *>(Address), |
| uint32_t(0x50003000), std::memory_order_release); // b #48 |
| } |
| return true; |
| } |
| |
| bool patchFunctionEntry(const bool Enable, const uint32_t FuncId, |
| const XRaySledEntry &Sled, |
| const XRayTrampolines &Trampolines, |
| bool LogArgs) XRAY_NEVER_INSTRUMENT { |
| auto Trampoline = |
| LogArgs ? Trampolines.LogArgsTrampoline : Trampolines.EntryTrampoline; |
| return patchSled(Enable, FuncId, Sled, Trampoline); |
| } |
| |
| bool patchFunctionExit( |
| const bool Enable, const uint32_t FuncId, const XRaySledEntry &Sled, |
| const XRayTrampolines &Trampolines) XRAY_NEVER_INSTRUMENT { |
| return patchSled(Enable, FuncId, Sled, Trampolines.ExitTrampoline); |
| } |
| |
| bool patchFunctionTailExit( |
| const bool Enable, const uint32_t FuncId, const XRaySledEntry &Sled, |
| const XRayTrampolines &Trampolines) XRAY_NEVER_INSTRUMENT { |
| // TODO: In the future we'd need to distinguish between non-tail exits and |
| // tail exits for better information preservation. |
| return patchSled(Enable, FuncId, Sled, Trampolines.ExitTrampoline); |
| } |
| |
| bool patchCustomEvent(const bool Enable, const uint32_t FuncId, |
| const XRaySledEntry &Sled) XRAY_NEVER_INSTRUMENT { |
| // FIXME: Implement in loongarch? |
| return false; |
| } |
| |
| bool patchTypedEvent(const bool Enable, const uint32_t FuncId, |
| const XRaySledEntry &Sled) XRAY_NEVER_INSTRUMENT { |
| // FIXME: Implement in loongarch? |
| return false; |
| } |
| } // namespace __xray |
| |
| extern "C" void __xray_ArgLoggerEntry() XRAY_NEVER_INSTRUMENT { |
| // TODO: This will have to be implemented in the trampoline assembly file. |
| } |
| |
| extern "C" void __xray_FunctionTailExit() XRAY_NEVER_INSTRUMENT { |
| // FIXME: this will have to be implemented in the trampoline assembly file |
| } |
