[PATCH] D106315: [HIP] Preserve ASAN bitcode library functions

[Yaxun Liu via Phabricator via cfe-commits]

yaxunl created this revision.
yaxunl added reviewers: tra, b-sumner.
Herald added subscribers: kerbowa, nhaehnle, jvesely.
yaxunl requested review of this revision.

Address sanitizer passes may generate call of ASAN bitcode library
functions after bitcode linking in lld, therefore lld cannot add
those symbols since it does not know they will be used later.

To solve this issue, clang emits a reference to a bicode library
function which calls all ASAN functions which need to be
preserved. This basically force all ASAN functions to be
linked in.


https://reviews.llvm.org/D106315

Files:
  clang/lib/CodeGen/CodeGenModule.cpp
  clang/lib/Driver/Driver.cpp
  clang/test/CodeGenCUDA/amdgpu-asan.cu
  clang/test/Driver/hip-sanitize-options.hip


Index: clang/test/Driver/hip-sanitize-options.hip
===================================================================
--- clang/test/Driver/hip-sanitize-options.hip
+++ clang/test/Driver/hip-sanitize-options.hip
@@ -34,7 +34,7 @@
 // CHECK-NOT: {{"[^"]*lld(\.exe){0,1}".* ".*hip.bc"}}
 // CHECK: {{"[^"]*clang[^"]*".* "-triple" "x86_64-unknown-linux-gnu".* "-fsanitize=address"}}
 
-// NORDC: {{"[^"]*clang[^"]*".* "-fcuda-is-device".* "-fsanitize=address".*}} "-o" "[[OUT:[^"]*.bc]]"
+// NORDC: {{"[^"]*clang[^"]*".* "-emit-obj".* "-fcuda-is-device".* "-fsanitize=address".*}} "-o" "[[OUT:[^"]*.o]]"
 // NORDC: {{"[^"]*lld(\.exe){0,1}".*}} "[[OUT]]" {{".*asanrtl.bc" ".*hip.bc"}}
 // NORDC: {{"[^"]*clang[^"]*".* "-triple" "x86_64-unknown-linux-gnu".* "-fsanitize=address"}}
 
Index: clang/test/CodeGenCUDA/amdgpu-asan.cu
===================================================================
--- /dev/null
+++ clang/test/CodeGenCUDA/amdgpu-asan.cu
@@ -0,0 +1,15 @@
+// RUN: %clang_cc1 %s -emit-llvm -o - -triple=amdgcn-amd-amdhsa \
+// RUN:   -fcuda-is-device -target-cpu gfx906 -fsanitize=address \
+// RUN:   -x hip | FileCheck -check-prefix=ASAN %s
+
+// RUN: %clang_cc1 %s -emit-llvm -o - -triple=amdgcn-amd-amdhsa \
+// RUN:   -fcuda-is-device -target-cpu gfx906 -x hip \
+// RUN:   | FileCheck %s
+
+// REQUIRES: amdgpu-registered-target
+
+// ASAN-DAG: declare void @__amdgpu_device_library_preserve_asan_functions() 
+// ASAN-DAG: @__amdgpu_device_library_preserve_asan_functions_ptr = weak addrspace(1) constant void ()* @__amdgpu_device_library_preserve_asan_functions
+// ASAN-DAG: @llvm.compiler.used = {{.*}}@__amdgpu_device_library_preserve_asan_functions_ptr
+
+// CHECK-NOT: @__amdgpu_device_library_preserve_asan_functions_ptr
Index: clang/lib/Driver/Driver.cpp
===================================================================
--- clang/lib/Driver/Driver.cpp
+++ clang/lib/Driver/Driver.cpp
@@ -2973,12 +2973,9 @@
         // a fat binary containing all the code objects for different GPU's.
         // The fat binary is then an input to the host action.
         for (unsigned I = 0, E = GpuArchList.size(); I != E; ++I) {
-          if (GPUSanitize || C.getDriver().isUsingLTO(/*IsOffload=*/true)) {
-            // When GPU sanitizer is enabled, since we need to link in the
-            // the sanitizer runtime library after the sanitize pass, we have
-            // to skip the backend and assemble phases and use lld to link
-            // the bitcode. The same happens if users request to use LTO
-            // explicitly.
+          if (C.getDriver().isUsingLTO(/*IsOffload=*/true)) {
+            // When LTO is enabled, skip the backend and assemble phases and
+            // use lld to link the bitcode.
             ActionList AL;
             AL.push_back(CudaDeviceActions[I]);
             // Create a link action to link device IR with device library
@@ -2986,7 +2983,7 @@
             CudaDeviceActions[I] =
                 C.MakeAction<LinkJobAction>(AL, types::TY_Image);
           } else {
-            // When GPU sanitizer is not enabled, we follow the conventional
+            // When LTO is not enabled, we follow the conventional
             // compiler phases, including backend and assemble phases.
             ActionList AL;
             auto BackendAction = C.getDriver().ConstructPhaseAction(
Index: clang/lib/CodeGen/CodeGenModule.cpp
===================================================================
--- clang/lib/CodeGen/CodeGenModule.cpp
+++ clang/lib/CodeGen/CodeGenModule.cpp
@@ -523,6 +523,22 @@
       !Context.getTargetInfo().getTriple().isOSEmscripten()) {
     EmitMainVoidAlias();
   }
+
+  // Emit reference of __amdgpu_device_library_preserve_asan_functions to
+  // preserve ASAN functions in bitcode libraries.
+  if (LangOpts.Sanitize.has(SanitizerKind::Address) && getTriple().isAMDGPU()) {
+    auto *FT = llvm::FunctionType::get(VoidTy, {});
+    auto *F = llvm::Function::Create(FT, llvm::GlobalValue::ExternalLinkage,
+        "__amdgpu_device_library_preserve_asan_functions",
+        &getModule());
+    auto *Var = new llvm::GlobalVariable(
+      getModule(), FT->getPointerTo(),
+      /*isConstant=*/true, llvm::GlobalValue::WeakAnyLinkage, F,
+      "__amdgpu_device_library_preserve_asan_functions_ptr", nullptr,
+      llvm::GlobalVariable::NotThreadLocal);
+    addCompilerUsedGlobal(Var);
+  }
+
   emitLLVMUsed();
   if (SanStats)
     SanStats->finish();


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