| //===-- xray_AArch64.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 AArch64-specific routines (64-bit). |
| // |
| //===----------------------------------------------------------------------===// |
| #include "sanitizer_common/sanitizer_common.h" |
| #include "xray_defs.h" |
| #include "xray_interface_internal.h" |
| #include <atomic> |
| #include <cassert> |
| |
| extern "C" void __clear_cache(void *start, void *end); |
| |
| namespace __xray { |
| |
| // The machine codes for some instructions used in runtime patching. |
| enum class PatchOpcodes : uint32_t { |
| PO_StpX0X30SP_m16e = 0xA9BF7BE0, // STP X0, X30, [SP, #-16]! |
| PO_LdrW0_12 = 0x18000060, // LDR W0, #12 |
| PO_LdrX16_12 = 0x58000070, // LDR X16, #12 |
| PO_BlrX16 = 0xD63F0200, // BLR X16 |
| PO_LdpX0X30SP_16 = 0xA8C17BE0, // LDP X0, X30, [SP], #16 |
| PO_B32 = 0x14000008 // B #32 |
| }; |
| |
| 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 #32 |
| // 7 NOPs (24 bytes) |
| // |
| // With the following runtime patch: |
| // |
| // xray_sled_n: |
| // STP X0, X30, [SP, #-16]! ; PUSH {r0, lr} |
| // LDR W0, #12 ; W0 := function ID |
| // LDR X16,#12 ; X16 := address of the trampoline |
| // BLR X16 |
| // ;DATA: 32 bits of function ID |
| // ;DATA: lower 32 bits of the address of the trampoline |
| // ;DATA: higher 32 bits of the address of the trampoline |
| // LDP X0, X30, [SP], #16 ; POP {r0, lr} |
| // |
| // 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 #32 |
| |
| uint32_t *FirstAddress = reinterpret_cast<uint32_t *>(Sled.Address); |
| uint32_t *CurAddress = FirstAddress + 1; |
| if (Enable) { |
| *CurAddress = uint32_t(PatchOpcodes::PO_LdrW0_12); |
| CurAddress++; |
| *CurAddress = uint32_t(PatchOpcodes::PO_LdrX16_12); |
| CurAddress++; |
| *CurAddress = uint32_t(PatchOpcodes::PO_BlrX16); |
| CurAddress++; |
| *CurAddress = FuncId; |
| CurAddress++; |
| *reinterpret_cast<void (**)()>(CurAddress) = TracingHook; |
| CurAddress += 2; |
| *CurAddress = uint32_t(PatchOpcodes::PO_LdpX0X30SP_16); |
| CurAddress++; |
| std::atomic_store_explicit( |
| reinterpret_cast<std::atomic<uint32_t> *>(FirstAddress), |
| uint32_t(PatchOpcodes::PO_StpX0X30SP_m16e), std::memory_order_release); |
| } else { |
| std::atomic_store_explicit( |
| reinterpret_cast<std::atomic<uint32_t> *>(FirstAddress), |
| uint32_t(PatchOpcodes::PO_B32), std::memory_order_release); |
| } |
| __clear_cache(reinterpret_cast<char *>(FirstAddress), |
| reinterpret_cast<char *>(CurAddress)); |
| 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 { |
| return patchSled(Enable, FuncId, Sled, __xray_FunctionTailExit); |
| } |
| |
| bool patchCustomEvent(const bool Enable, const uint32_t FuncId, |
| const XRaySledEntry &Sled) |
| XRAY_NEVER_INSTRUMENT { // FIXME: Implement in aarch64? |
| return false; |
| } |
| |
| bool patchTypedEvent(const bool Enable, const uint32_t FuncId, |
| const XRaySledEntry &Sled) XRAY_NEVER_INSTRUMENT { |
| // FIXME: Implement in aarch64? |
| return false; |
| } |
| |
| // FIXME: Maybe implement this better? |
| bool probeRequiredCPUFeatures() XRAY_NEVER_INSTRUMENT { return true; } |
| |
| } // namespace __xray |
| |
| extern "C" void __xray_ArgLoggerEntry() XRAY_NEVER_INSTRUMENT { |
| // FIXME: this will have to be implemented in the trampoline assembly file |
| } |