[PATCH] D106888: [RISC-V] Implement jump tables for CFI-icall

[Wende Tan via Phabricator via llvm-commits]

twd2 created this revision.
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This patch implements jump tables for RISC-V so that CFI-icall can be enabled for it.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D106888

Files:
  clang/lib/Driver/ToolChain.cpp
  clang/test/Driver/fsanitize.c
  llvm/lib/Transforms/IPO/LowerTypeTests.cpp


Index: llvm/lib/Transforms/IPO/LowerTypeTests.cpp
===================================================================
--- llvm/lib/Transforms/IPO/LowerTypeTests.cpp
+++ llvm/lib/Transforms/IPO/LowerTypeTests.cpp
@@ -1211,6 +1211,7 @@
 static const unsigned kX86JumpTableEntrySize = 8;
 static const unsigned kARMJumpTableEntrySize = 4;
 static const unsigned kARMBTIJumpTableEntrySize = 8;
+static const unsigned kRISCVJumpTableEntrySize = 8;
 
 unsigned LowerTypeTestsModule::getJumpTableEntrySize() {
   switch (Arch) {
@@ -1226,6 +1227,9 @@
         if (BTE->getZExtValue())
           return kARMBTIJumpTableEntrySize;
       return kARMJumpTableEntrySize;
+    case Triple::riscv32:
+    case Triple::riscv64:
+      return kRISCVJumpTableEntrySize;
     default:
       report_fatal_error("Unsupported architecture for jump tables");
   }
@@ -1253,6 +1257,10 @@
     AsmOS << "b $" << ArgIndex << "\n";
   } else if (JumpTableArch == Triple::thumb) {
     AsmOS << "b.w $" << ArgIndex << "\n";
+  } else if (JumpTableArch == Triple::riscv32 ||
+             JumpTableArch == Triple::riscv64) {
+    AsmOS << "1: auipc t0, %pcrel_hi($" << ArgIndex << ")\n"
+          << "jr %pcrel_lo(1b)(t0)\n";
   } else {
     report_fatal_error("Unsupported architecture for jump tables");
   }
@@ -1270,7 +1278,8 @@
 void LowerTypeTestsModule::buildBitSetsFromFunctions(
     ArrayRef<Metadata *> TypeIds, ArrayRef<GlobalTypeMember *> Functions) {
   if (Arch == Triple::x86 || Arch == Triple::x86_64 || Arch == Triple::arm ||
-      Arch == Triple::thumb || Arch == Triple::aarch64)
+      Arch == Triple::thumb || Arch == Triple::aarch64 ||
+      Arch == Triple::riscv32 || Arch == Triple::riscv64)
     buildBitSetsFromFunctionsNative(TypeIds, Functions);
   else if (Arch == Triple::wasm32 || Arch == Triple::wasm64)
     buildBitSetsFromFunctionsWASM(TypeIds, Functions);
@@ -1415,6 +1424,11 @@
     F->addFnAttr("branch-target-enforcement", "false");
     F->addFnAttr("sign-return-address", "none");
   }
+  if (JumpTableArch == Triple::riscv32 || JumpTableArch == Triple::riscv64) {
+    // Make sure the jump table assembly is not modified by the assembler or
+    // the linker.
+    F->addFnAttr("target-features", "-c,-relax");
+  }
   // Make sure we don't emit .eh_frame for this function.
   F->addFnAttr(Attribute::NoUnwind);
 
Index: clang/test/Driver/fsanitize.c
===================================================================
--- clang/test/Driver/fsanitize.c
+++ clang/test/Driver/fsanitize.c
@@ -603,6 +603,8 @@
 // RUN: %clang -target arm-linux-android -fvisibility=hidden -fsanitize=cfi -flto -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CFI
 // RUN: %clang -target aarch64-linux-android -fvisibility=hidden -fsanitize=cfi -flto -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CFI
 // RUN: %clang -target aarch64_be -fvisibility=hidden -fsanitize=cfi -flto -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CFI
+// RUN: %clang -target riscv32 -fvisibility=hidden -fsanitize=cfi -flto -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CFI
+// RUN: %clang -target riscv64 -fvisibility=hidden -fsanitize=cfi -flto -c %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-CFI
 // CHECK-CFI: -emit-llvm-bc{{.*}}-fsanitize=cfi-derived-cast,cfi-icall,cfi-mfcall,cfi-unrelated-cast,cfi-nvcall,cfi-vcall
 // CHECK-CFI-NOMFCALL: -emit-llvm-bc{{.*}}-fsanitize=cfi-derived-cast,cfi-icall,cfi-unrelated-cast,cfi-nvcall,cfi-vcall
 // CHECK-CFI-DCAST: -emit-llvm-bc{{.*}}-fsanitize=cfi-derived-cast
Index: clang/lib/Driver/ToolChain.cpp
===================================================================
--- clang/lib/Driver/ToolChain.cpp
+++ clang/lib/Driver/ToolChain.cpp
@@ -1008,7 +1008,7 @@
   if (getTriple().getArch() == llvm::Triple::x86 ||
       getTriple().getArch() == llvm::Triple::x86_64 ||
       getTriple().getArch() == llvm::Triple::arm || getTriple().isWasm() ||
-      getTriple().isAArch64())
+      getTriple().isAArch64() || getTriple().isRISCV())
     Res |= SanitizerKind::CFIICall;
   if (getTriple().getArch() == llvm::Triple::x86_64 ||
       getTriple().isAArch64(64) || getTriple().isRISCV())


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