[XRay][RISCV] RISCV support for XRay

clang/lib/Driver/XRayArgs.cpp

@@ -51,6 +51,8 @@ XRayArgs::XRayArgs(const ToolChain &TC, const ArgList &Args) {
     case llvm::Triple::mips64:
     case llvm::Triple::mips64el:
     case llvm::Triple::systemz:
+    case llvm::Triple::riscv32:
+    case llvm::Triple::riscv64:
       break;
     default:
       D.Diag(diag::err_drv_unsupported_opt_for_target)

compiler-rt/cmake/Modules/AllSupportedArchDefs.cmake

@@ -102,7 +102,7 @@ if(APPLE)
 set(ALL_XRAY_SUPPORTED_ARCH ${X86_64} ${ARM64})
 else()
 set(ALL_XRAY_SUPPORTED_ARCH ${X86_64} ${ARM32} ${ARM64} ${MIPS32} ${MIPS64}
-		powerpc64le ${HEXAGON} ${LOONGARCH64})
+               powerpc64le ${HEXAGON} ${LOONGARCH64} ${RISCV32} ${RISCV64})
 endif()
 set(ALL_XRAY_DSO_SUPPORTED_ARCH ${X86_64} ${ARM64})
 set(ALL_SHADOWCALLSTACK_SUPPORTED_ARCH ${ARM64})

compiler-rt/lib/xray/CMakeLists.txt

@@ -96,6 +96,16 @@ set(hexagon_SOURCES
   xray_trampoline_hexagon.S
   )
 
+set(riscv32_SOURCES
+  xray_riscv.cpp
+  xray_trampoline_riscv32.S
+  )
+
+set(riscv64_SOURCES
+  xray_riscv.cpp
+  xray_trampoline_riscv64.S
+  )
+
 set(XRAY_SOURCE_ARCHS
   arm
   armhf
@@ -156,6 +166,8 @@ set(XRAY_ALL_SOURCE_FILES
   ${mips64_SOURCES}
   ${mips64el_SOURCES}
   ${powerpc64le_SOURCES}
+  ${riscv32_SOURCES}
+  ${riscv64_SOURCES}
   ${XRAY_IMPL_HEADERS}
   )
 list(REMOVE_DUPLICATES XRAY_ALL_SOURCE_FILES)

compiler-rt/lib/xray/xray_interface.cpp

@@ -57,6 +57,10 @@ static const int16_t cSledLength = 64;
 static const int16_t cSledLength = 8;
 #elif defined(__hexagon__)
 static const int16_t cSledLength = 20;
+#elif defined(__riscv) && (__riscv_xlen == 64)
+static const int16_t cSledLength = 68;
+#elif defined(__riscv) && (__riscv_xlen == 32)
+static const int16_t cSledLength = 52;
 #else
 #error "Unsupported CPU Architecture"
 #endif /* CPU architecture */

compiler-rt/lib/xray/xray_riscv.cpp

@@ -0,0 +1,266 @@
+//===-- xray_riscv.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 RISC-V specific routines (32- and 64-bit).
+//
+//===----------------------------------------------------------------------===//
+#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_ADDI = 0x00000013, // addi rd, rs1, imm
+  PO_ADD = 0x00000033,  // add rd, rs1, rs2
+  PO_SW = 0x00002023,   // sw rs2, imm(rs1)
+  PO_SD = 0x00003023,   // sd rs2, imm(rs1)
+  PO_LUI = 0x00000037,  // lui rd, imm
+  PO_OR = 0x00006033,   // or rd, rs1, rs2
+  PO_SLLI = 0x00001013, // slli rd, rs1, shamt
+  PO_JALR = 0x00000067, // jalr rd, rs1
+  PO_LW = 0x00002003,   // lw rd, imm(rs1)
+  PO_LD = 0x00003003,   // ld rd, imm(rs1)
+  PO_J = 0x0000006f,    // jal imm
+  PO_NOP = PO_ADDI,     // addi x0, x0, 0
+};
+
+enum RegNum : uint32_t {
+  RN_X0 = 0,
+  RN_RA = 1,
+  RN_SP = 2,
+  RN_T1 = 6,
+  RN_A0 = 10,
+};
+
+static inline uint32_t encodeRTypeInstruction(uint32_t Opcode, uint32_t Rs1,
+                                              uint32_t Rs2, uint32_t Rd) {
+  return Rs2 << 20 | Rs1 << 15 | Rd << 7 | Opcode;
+}
+
+static inline uint32_t encodeITypeInstruction(uint32_t Opcode, uint32_t Rs1,
+                                              uint32_t Rd, uint32_t Imm) {
+  return Imm << 20 | Rs1 << 15 | Rd << 7 | Opcode;
+}
+
+static inline uint32_t encodeSTypeInstruction(uint32_t Opcode, uint32_t Rs1,
+                                              uint32_t Rs2, uint32_t Imm) {
+  uint32_t ImmMSB = (Imm & 0xfe0) << 20;
+  uint32_t ImmLSB = (Imm & 0x01f) << 7;
+  return ImmMSB | Rs2 << 20 | Rs1 << 15 | ImmLSB | Opcode;
+}
+
+static inline uint32_t encodeUTypeInstruction(uint32_t Opcode, uint32_t Rd,
+                                              uint32_t Imm) {
+  return Imm << 12 | Rd << 7 | Opcode;
+}
+
+static inline uint32_t encodeJTypeInstruction(uint32_t Opcode, uint32_t Rd,
+                                              uint32_t Imm) {
+  uint32_t ImmMSB = (Imm & 0x100000) << 11;
+  uint32_t ImmLSB = (Imm & 0x7fe) << 20;
+  uint32_t Imm11 = (Imm & 0x800) << 9;
+  uint32_t Imm1912 = (Imm & 0xff000);
+  return ImmMSB | ImmLSB | Imm11 | Imm1912 | Rd << 7 | Opcode;
+}
+
+static uint32_t hi20(uint32_t val) { return (val + 0x800) >> 12; }
+static uint32_t lo12(uint32_t val) { return val & 0xfff; }
+
+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):
+  //
+  // xray_sled_n:
+  //	J .tmpN
+  //	21 or 33 C.NOPs (42 or 66 bytes)
+  //	.tmpN
+  //
+  // With one of the following runtime patches:
+  //
+  // xray_sled_n (32-bit):
+  //    addi sp, sp, -16                                ;create stack frame
+  //    sw ra, 12(sp)                                   ;save return address
+  //    sw a0, 8(sp)                                    ;save register a0
+  //    lui ra, %hi(__xray_FunctionEntry/Exit)
+  //    addi ra, ra, %lo(__xray_FunctionEntry/Exit)
+  //    lui a0, %hi(function_id)
+  //    addi a0, a0, %lo(function_id)                   ;pass function id
+  //    jalr ra                                         ;call Tracing hook
+  //    lw a0, 8(sp)                                    ;restore register a0
+  //    lw ra, 12(sp)                                   ;restore return address
+  //    addi sp, sp, 16                                 ;delete stack frame
+  //
+  // xray_sled_n (64-bit):
+  //    addi sp, sp, -32                                ;create stack frame
+  //    sd ra, 24(sp)                                   ;save return address
+  //    sd a0, 16(sp)                                   ;save register a0
+  //    sd t1, 8(sp)                                    ;save register t1
+  //    lui t1, %highest(__xray_FunctionEntry/Exit)
+  //    addi t1, t1, %higher(__xray_FunctionEntry/Exit)
+  //    slli t1, t1, 32
+  //    lui ra, ra, %hi(__xray_FunctionEntry/Exit)
+  //    addi ra, ra, %lo(__xray_FunctionEntry/Exit)
+  //    add ra, t1, ra
+  //    lui a0, %hi(function_id)
+  //    addi a0, a0, %lo(function_id)                   ;pass function id
+  //    jalr ra                                         ;call Tracing hook
+  //    ld t1, 8(sp)                                    ;restore register t1
+  //    ld a0, 16(sp)                                   ;restore register a0
+  //    ld ra, 24(sp)                                   ;restore return address
+  //    addi sp, sp, 32                                 ;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
+  //   J 44 bytes (rv32)
+  //   J 68 bytes (rv64)
+
+  uint32_t *Address = reinterpret_cast<uint32_t *>(Sled.address());
+  if (Enable) {
+#if __riscv_xlen == 64
+    // If the ISA is RV64, the Tracing Hook needs to be typecast to a 64 bit
+    // value.
+    uint32_t LoTracingHookAddr = lo12(reinterpret_cast<uint64_t>(TracingHook));
+    uint32_t HiTracingHookAddr = hi20(reinterpret_cast<uint64_t>(TracingHook));
+    uint32_t HigherTracingHookAddr =
+        lo12((reinterpret_cast<uint64_t>(TracingHook) + 0x80000000) >> 32);
+    uint32_t HighestTracingHookAddr =
+        hi20((reinterpret_cast<uint64_t>(TracingHook) + 0x80000000) >> 32);
+#elif __riscv_xlen == 32
+    // We typecast the Tracing Hook to a 32 bit value for RV32
+    uint32_t LoTracingHookAddr = lo12(reinterpret_cast<uint32_t>(TracingHook));
+    uint32_t HiTracingHookAddr = hi20((reinterpret_cast<uint32_t>(TracingHook));
+#endif
+    uint32_t LoFunctionID = lo12(FuncId);
+    uint32_t HiFunctionID = hi20(FuncId);
+
+    // The sled that is patched in for RISCV64 defined below. We need the entire
+    // sleds corresponding to both ISAs to be protected by defines because the
+    // first few instructions are all different, because we store doubles in
+    // case of RV64 and store words for RV32. Subsequently, we have LUI - and in
+    // case of RV64, we need extra instructions from this point on, so we see
+    // differences in addresses to which instructions are stored.
+    size_t Idx = 1U;
+    const uint32_t XLenBytes = __riscv_xlen / 8;
+#if __riscv_xlen == 64
+    const uint32_t LoadOp = PatchOpcodes::PO_LD;
+    const uint32_t StoreOp = PatchOpcodes::PO_SD;
+#elif __riscv_xlen == 32
+    const uint32_t LoadOp = PatchOpcodes::PO_LW;
+    const uint32_t StoreOp = PatchOpcodes::PO_SW;
+#endif
+
+    Address[Idx++] = encodeSTypeInstruction(StoreOp, RegNum::RN_SP,
+                                            RegNum::RN_RA, 3 * XLenBytes);
+    Address[Idx++] = encodeSTypeInstruction(StoreOp, RegNum::RN_SP,
+                                            RegNum::RN_A0, 2 * XLenBytes);
+
+#if __riscv_xlen == 64
+    Address[Idx++] = encodeSTypeInstruction(StoreOp, RegNum::RN_SP,
+                                            RegNum::RN_T1, XLenBytes);
+    Address[Idx++] = encodeUTypeInstruction(PatchOpcodes::PO_LUI, RegNum::RN_T1,
+                                            HighestTracingHookAddr);
+    Address[Idx++] =
+        encodeITypeInstruction(PatchOpcodes::PO_ADDI, RegNum::RN_T1,
+                               RegNum::RN_T1, HigherTracingHookAddr);
+    Address[Idx++] = encodeITypeInstruction(PatchOpcodes::PO_SLLI,
+                                            RegNum::RN_T1, RegNum::RN_T1, 32);
+#endif
+    Address[Idx++] = encodeUTypeInstruction(PatchOpcodes::PO_LUI, RegNum::RN_RA,
+                                            HiTracingHookAddr);
+    Address[Idx++] = encodeITypeInstruction(
+        PatchOpcodes::PO_ADDI, RegNum::RN_RA, RegNum::RN_RA, LoTracingHookAddr);
+#if __riscv_xlen == 64
+    Address[Idx++] = encodeRTypeInstruction(PatchOpcodes::PO_ADD, RegNum::RN_RA,
+                                            RegNum::RN_T1, RegNum::RN_RA);
+#endif
+    Address[Idx++] = encodeUTypeInstruction(PatchOpcodes::PO_LUI, RegNum::RN_A0,
+                                            HiFunctionID);
+    Address[Idx++] = encodeITypeInstruction(
+        PatchOpcodes::PO_ADDI, RegNum::RN_A0, RegNum::RN_A0, LoFunctionID);
+    Address[Idx++] = encodeITypeInstruction(PatchOpcodes::PO_JALR,
+                                            RegNum::RN_RA, RegNum::RN_RA, 0);
+
+#if __riscv_xlen == 64
+    Address[Idx++] =
+        encodeITypeInstruction(LoadOp, RegNum::RN_SP, RegNum::RN_T1, XLenBytes);
+#endif
+    Address[Idx++] = encodeITypeInstruction(LoadOp, RegNum::RN_SP,
+                                            RegNum::RN_A0, 2 * XLenBytes);
+    Address[Idx++] = encodeITypeInstruction(LoadOp, RegNum::RN_SP,
+                                            RegNum::RN_RA, 3 * XLenBytes);
+    Address[Idx++] = encodeITypeInstruction(
+        PatchOpcodes::PO_ADDI, RegNum::RN_SP, RegNum::RN_SP, 4 * XLenBytes);
+
+    uint32_t CreateStackSpace = encodeITypeInstruction(
+        PatchOpcodes::PO_ADDI, RegNum::RN_SP, RegNum::RN_SP, -4 * XLenBytes);
+
+    std::atomic_store_explicit(
+        reinterpret_cast<std::atomic<uint32_t> *>(Address), CreateStackSpace,
+        std::memory_order_release);
+  } else {
+    uint32_t CreateBranch = encodeJTypeInstruction(
+    // Jump distance is different in both ISAs due to difference in size of
+    // sleds
+#if __riscv_xlen == 64
+        PatchOpcodes::PO_J, RegNum::RN_X0,
+        68); // jump encodes an offset of 68
+#elif __riscv_xlen == 32
+        PatchOpcodes::PO_J, RegNum::RN_X0,
+        44); // jump encodes an offset of 44
+#endif
+    std::atomic_store_explicit(
+        reinterpret_cast<std::atomic<uint32_t> *>(Address), CreateBranch,
+        std::memory_order_release);
+  }
+  return true;
+}
+
+bool patchFunctionEntry(const bool Enable, const uint32_t FuncId,
+                        const XRaySledEntry &Sled,
+                        const XRayTrampolines &Trampolines,
+                        bool LogArgs) XRAY_NEVER_INSTRUMENT {
+  // We don't support logging argument at this moment, so we always
+  // use EntryTrampoline.
+  return patchSled(Enable, FuncId, Sled, Trampolines.EntryTrampoline);
+}
+
+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 {
+  return patchSled(Enable, FuncId, Sled, Trampolines.TailExitTrampoline);
+}
+
+bool patchCustomEvent(const bool Enable, const uint32_t FuncId,
+                      const XRaySledEntry &Sled) XRAY_NEVER_INSTRUMENT {
+  return false;
+}
+
+bool patchTypedEvent(const bool Enable, const uint32_t FuncId,
+                     const XRaySledEntry &Sled) XRAY_NEVER_INSTRUMENT {
+  return false;
+}
+} // namespace __xray
+
+extern "C" void __xray_ArgLoggerEntry() XRAY_NEVER_INSTRUMENT {}