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Diffstat (limited to 'lib/xray/xray_mips64.cc')
| -rw-r--r-- | lib/xray/xray_mips64.cc | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/lib/xray/xray_mips64.cc b/lib/xray/xray_mips64.cc new file mode 100644 index 000000000000..21136848c8af --- /dev/null +++ b/lib/xray/xray_mips64.cc @@ -0,0 +1,167 @@ +//===-- xray_mips64.cc ------------------------------------------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file is a part of XRay, a dynamic runtime instrumentation system. +// +// Implementation of MIPS64-specific routines. +// +//===----------------------------------------------------------------------===// +#include "sanitizer_common/sanitizer_common.h" +#include "xray_defs.h" +#include "xray_interface_internal.h" +#include <atomic> + +namespace __xray { + +// The machine codes for some instructions used in runtime patching. +enum PatchOpcodes : uint32_t { + PO_DADDIU = 0x64000000, // daddiu rt, rs, imm + PO_SD = 0xFC000000, // sd rt, base(offset) + PO_LUI = 0x3C000000, // lui rt, imm + PO_ORI = 0x34000000, // ori rt, rs, imm + PO_DSLL = 0x00000038, // dsll rd, rt, sa + PO_JALR = 0x00000009, // jalr rs + PO_LD = 0xDC000000, // ld rt, base(offset) + PO_B60 = 0x1000000f, // b #60 + PO_NOP = 0x0, // nop +}; + +enum RegNum : uint32_t { + RN_T0 = 0xC, + RN_T9 = 0x19, + RN_RA = 0x1F, + RN_SP = 0x1D, +}; + +inline static uint32_t encodeInstruction(uint32_t Opcode, uint32_t Rs, + uint32_t Rt, + uint32_t Imm) XRAY_NEVER_INSTRUMENT { + return (Opcode | Rs << 21 | Rt << 16 | Imm); +} + +inline static uint32_t +encodeSpecialInstruction(uint32_t Opcode, uint32_t Rs, uint32_t Rt, uint32_t Rd, + uint32_t Imm) XRAY_NEVER_INSTRUMENT { + return (Rs << 21 | Rt << 16 | Rd << 11 | Imm << 6 | Opcode); +} + +inline static 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): + // + // xray_sled_n: + // B .tmpN + // 15 NOPs (60 bytes) + // .tmpN + // + // With the following runtime patch: + // + // xray_sled_n (64-bit): + // daddiu sp, sp, -16 ;create stack frame + // nop + // sd ra, 8(sp) ;save return address + // sd t9, 0(sp) ;save register t9 + // lui t9, %highest(__xray_FunctionEntry/Exit) + // ori t9, t9, %higher(__xray_FunctionEntry/Exit) + // dsll t9, t9, 16 + // ori t9, t9, %hi(__xray_FunctionEntry/Exit) + // dsll t9, t9, 16 + // ori t9, t9, %lo(__xray_FunctionEntry/Exit) + // lui t0, %hi(function_id) + // jalr t9 ;call Tracing hook + // ori t0, t0, %lo(function_id) ;pass function id (delay slot) + // ld t9, 0(sp) ;restore register t9 + // ld ra, 8(sp) ;restore return address + // daddiu sp, sp, 16 ;delete 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 back the first instruction in the sled to be + // B #60 + + if (Enable) { + uint32_t LoTracingHookAddr = + reinterpret_cast<int64_t>(TracingHook) & 0xffff; + uint32_t HiTracingHookAddr = (reinterpret_cast<int64_t>(TracingHook) >> 16) & 0xffff; + uint32_t HigherTracingHookAddr = + (reinterpret_cast<int64_t>(TracingHook) >> 32) & 0xffff; + uint32_t HighestTracingHookAddr = + (reinterpret_cast<int64_t>(TracingHook) >> 48) & 0xffff; + uint32_t LoFunctionID = FuncId & 0xffff; + uint32_t HiFunctionID = (FuncId >> 16) & 0xffff; + *reinterpret_cast<uint32_t *>(Sled.Address + 8) = encodeInstruction( + PatchOpcodes::PO_SD, RegNum::RN_SP, RegNum::RN_RA, 0x8); + *reinterpret_cast<uint32_t *>(Sled.Address + 12) = encodeInstruction( + PatchOpcodes::PO_SD, RegNum::RN_SP, RegNum::RN_T9, 0x0); + *reinterpret_cast<uint32_t *>(Sled.Address + 16) = encodeInstruction( + PatchOpcodes::PO_LUI, 0x0, RegNum::RN_T9, HighestTracingHookAddr); + *reinterpret_cast<uint32_t *>(Sled.Address + 20) = + encodeInstruction(PatchOpcodes::PO_ORI, RegNum::RN_T9, RegNum::RN_T9, + HigherTracingHookAddr); + *reinterpret_cast<uint32_t *>(Sled.Address + 24) = encodeSpecialInstruction( + PatchOpcodes::PO_DSLL, 0x0, RegNum::RN_T9, RegNum::RN_T9, 0x10); + *reinterpret_cast<uint32_t *>(Sled.Address + 28) = encodeInstruction( + PatchOpcodes::PO_ORI, RegNum::RN_T9, RegNum::RN_T9, HiTracingHookAddr); + *reinterpret_cast<uint32_t *>(Sled.Address + 32) = encodeSpecialInstruction( + PatchOpcodes::PO_DSLL, 0x0, RegNum::RN_T9, RegNum::RN_T9, 0x10); + *reinterpret_cast<uint32_t *>(Sled.Address + 36) = encodeInstruction( + PatchOpcodes::PO_ORI, RegNum::RN_T9, RegNum::RN_T9, LoTracingHookAddr); + *reinterpret_cast<uint32_t *>(Sled.Address + 40) = encodeInstruction( + PatchOpcodes::PO_LUI, 0x0, RegNum::RN_T0, HiFunctionID); + *reinterpret_cast<uint32_t *>(Sled.Address + 44) = encodeSpecialInstruction( + PatchOpcodes::PO_JALR, RegNum::RN_T9, 0x0, RegNum::RN_RA, 0X0); + *reinterpret_cast<uint32_t *>(Sled.Address + 48) = encodeInstruction( + PatchOpcodes::PO_ORI, RegNum::RN_T0, RegNum::RN_T0, LoFunctionID); + *reinterpret_cast<uint32_t *>(Sled.Address + 52) = encodeInstruction( + PatchOpcodes::PO_LD, RegNum::RN_SP, RegNum::RN_T9, 0x0); + *reinterpret_cast<uint32_t *>(Sled.Address + 56) = encodeInstruction( + PatchOpcodes::PO_LD, RegNum::RN_SP, RegNum::RN_RA, 0x8); + *reinterpret_cast<uint32_t *>(Sled.Address + 60) = encodeInstruction( + PatchOpcodes::PO_DADDIU, RegNum::RN_SP, RegNum::RN_SP, 0x10); + uint32_t CreateStackSpace = encodeInstruction( + PatchOpcodes::PO_DADDIU, RegNum::RN_SP, RegNum::RN_SP, 0xfff0); + std::atomic_store_explicit( + reinterpret_cast<std::atomic<uint32_t> *>(Sled.Address), + CreateStackSpace, std::memory_order_release); + } else { + std::atomic_store_explicit( + reinterpret_cast<std::atomic<uint32_t> *>(Sled.Address), + uint32_t(PatchOpcodes::PO_B60), std::memory_order_release); + } + return true; +} + +bool patchFunctionEntry(const bool Enable, const uint32_t FuncId, + const XRaySledEntry &Sled, + void (*Trampoline)()) XRAY_NEVER_INSTRUMENT { + return patchSled(Enable, FuncId, Sled, Trampoline); +} + +bool patchFunctionExit(const bool Enable, const uint32_t FuncId, + const XRaySledEntry &Sled) XRAY_NEVER_INSTRUMENT { + return patchSled(Enable, FuncId, Sled, __xray_FunctionExit); +} + +bool patchFunctionTailExit(const bool Enable, const uint32_t FuncId, + const XRaySledEntry &Sled) XRAY_NEVER_INSTRUMENT { + // FIXME: In the future we'd need to distinguish between non-tail exits and + // tail exits for better information preservation. + return patchSled(Enable, FuncId, Sled, __xray_FunctionExit); +} + +} // namespace __xray + +extern "C" void __xray_ArgLoggerEntry() XRAY_NEVER_INSTRUMENT { + // FIXME: this will have to be implemented in the trampoline assembly file +} |