[clang] 44dbbe6 - [HIP] Preserve ASAN bitcode library functions

[Yaxun Liu via cfe-commits]

Author: Yaxun (Sam) Liu
Date: 2021-07-23T10:35:52-04:00
New Revision: 44dbbe61060acac4d0991a15decac4c909e26844

URL: https://github.com/llvm/llvm-project/commit/44dbbe61060acac4d0991a15decac4c909e26844
DIFF: https://github.com/llvm/llvm-project/commit/44dbbe61060acac4d0991a15decac4c909e26844.diff

LOG: [HIP] Preserve ASAN bitcode library functions

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.

Reviewed by: Artem Belevich

Differential Revision: https://reviews.llvm.org/D106315

Added: 
    clang/test/CodeGenCUDA/amdgpu-asan.cu

Modified: 
    clang/lib/CodeGen/CodeGenModule.cpp
    clang/lib/Driver/Driver.cpp
    clang/test/Driver/hip-sanitize-options.hip

Removed: 
    


################################################################################
diff  --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index fc1d8d924349..9b40b88ea3c9 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -523,6 +523,22 @@ void CodeGenModule::Release() {
       !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();

diff  --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index cbc853370e89..9714c3c42e84 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -2973,12 +2973,9 @@ class OffloadingActionBuilder final {
         // a fat binary containing all the code objects for 
diff erent 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 @@ class OffloadingActionBuilder final {
             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(

diff  --git a/clang/test/CodeGenCUDA/amdgpu-asan.cu b/clang/test/CodeGenCUDA/amdgpu-asan.cu
new file mode 100644
index 000000000000..fab0d48ef3c9
--- /dev/null
+++ b/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

diff  --git a/clang/test/Driver/hip-sanitize-options.hip b/clang/test/Driver/hip-sanitize-options.hip
index 3b0328b5abc2..7df800f0c04f 100644
--- a/clang/test/Driver/hip-sanitize-options.hip
+++ b/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"}}