From: Dmitry Vyukov Date: Tue, 27 Jan 2015 20:19:17 +0000 (+0000) Subject: tsan: properly instrument unaligned accesses X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=a18b3e06fca71e9f3e45b767c802436794668bdd;p=oota-llvm.git tsan: properly instrument unaligned accesses If a memory access is unaligned, emit __tsan_unaligned_read/write callbacks instead of __tsan_read/write. Required to change semantics of __tsan_unaligned_read/write to not do the user memory. But since they were unused (other than through __sanitizer_unaligned_load/store) this is fine. Fixes long standing issue 17: https://code.google.com/p/thread-sanitizer/issues/detail?id=17 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227231 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/lib/Transforms/Instrumentation/ThreadSanitizer.cpp b/lib/Transforms/Instrumentation/ThreadSanitizer.cpp index 1b86ae5acf7..e9999c486fa 100644 --- a/lib/Transforms/Instrumentation/ThreadSanitizer.cpp +++ b/lib/Transforms/Instrumentation/ThreadSanitizer.cpp @@ -99,6 +99,8 @@ struct ThreadSanitizer : public FunctionPass { static const size_t kNumberOfAccessSizes = 5; Function *TsanRead[kNumberOfAccessSizes]; Function *TsanWrite[kNumberOfAccessSizes]; + Function *TsanUnalignedRead[kNumberOfAccessSizes]; + Function *TsanUnalignedWrite[kNumberOfAccessSizes]; Function *TsanAtomicLoad[kNumberOfAccessSizes]; Function *TsanAtomicStore[kNumberOfAccessSizes]; Function *TsanAtomicRMW[AtomicRMWInst::LAST_BINOP + 1][kNumberOfAccessSizes]; @@ -150,6 +152,16 @@ void ThreadSanitizer::initializeCallbacks(Module &M) { TsanWrite[i] = checkInterfaceFunction(M.getOrInsertFunction( WriteName, IRB.getVoidTy(), IRB.getInt8PtrTy(), nullptr)); + SmallString<64> UnalignedReadName("__tsan_unaligned_read" + + itostr(ByteSize)); + TsanUnalignedRead[i] = checkInterfaceFunction(M.getOrInsertFunction( + UnalignedReadName, IRB.getVoidTy(), IRB.getInt8PtrTy(), nullptr)); + + SmallString<64> UnalignedWriteName("__tsan_unaligned_write" + + itostr(ByteSize)); + TsanUnalignedWrite[i] = checkInterfaceFunction(M.getOrInsertFunction( + UnalignedWriteName, IRB.getVoidTy(), IRB.getInt8PtrTy(), nullptr)); + Type *Ty = Type::getIntNTy(M.getContext(), BitSize); Type *PtrTy = Ty->getPointerTo(); SmallString<32> AtomicLoadName("__tsan_atomic" + itostr(BitSize) + @@ -412,7 +424,16 @@ bool ThreadSanitizer::instrumentLoadOrStore(Instruction *I) { NumInstrumentedVtableReads++; return true; } - Value *OnAccessFunc = IsWrite ? TsanWrite[Idx] : TsanRead[Idx]; + const unsigned Alignment = IsWrite + ? cast(I)->getAlignment() + : cast(I)->getAlignment(); + Type *OrigTy = cast(Addr->getType())->getElementType(); + const uint32_t TypeSize = DL->getTypeStoreSizeInBits(OrigTy); + Value *OnAccessFunc = nullptr; + if (Alignment == 0 || Alignment >= 8 || (Alignment % (TypeSize / 8)) == 0) + OnAccessFunc = IsWrite ? TsanWrite[Idx] : TsanRead[Idx]; + else + OnAccessFunc = IsWrite ? TsanUnalignedWrite[Idx] : TsanUnalignedRead[Idx]; IRB.CreateCall(OnAccessFunc, IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy())); if (IsWrite) NumInstrumentedWrites++; else NumInstrumentedReads++; diff --git a/test/Instrumentation/ThreadSanitizer/unaligned.ll b/test/Instrumentation/ThreadSanitizer/unaligned.ll new file mode 100644 index 00000000000..7a240e32831 --- /dev/null +++ b/test/Instrumentation/ThreadSanitizer/unaligned.ll @@ -0,0 +1,143 @@ +; RUN: opt < %s -tsan -S | FileCheck %s + +target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128" + +define i16 @test_unaligned_read2(i16* %a) sanitize_thread { +entry: + %tmp1 = load i16* %a, align 1 + ret i16 %tmp1 +} + +; CHECK-LABEL: define i16 @test_unaligned_read2(i16* %a) +; CHECK: call void @__tsan_func_entry(i8* %0) +; CHECK-NEXT: %1 = bitcast i16* %a to i8* +; CHECK-NEXT: call void @__tsan_unaligned_read2(i8* %1) +; CHECK-NEXT: %tmp1 = load i16* %a, align 1 +; CHECK-NEXT: call void @__tsan_func_exit() +; CHECK: ret i16 + +define i32 @test_unaligned_read4(i32* %a) sanitize_thread { +entry: + %tmp1 = load i32* %a, align 2 + ret i32 %tmp1 +} + +; CHECK-LABEL: define i32 @test_unaligned_read4(i32* %a) +; CHECK: call void @__tsan_func_entry(i8* %0) +; CHECK-NEXT: %1 = bitcast i32* %a to i8* +; CHECK-NEXT: call void @__tsan_unaligned_read4(i8* %1) +; CHECK-NEXT: %tmp1 = load i32* %a, align 2 +; CHECK-NEXT: call void @__tsan_func_exit() +; CHECK: ret i32 + +define i64 @test_unaligned_read8(i64* %a) sanitize_thread { +entry: + %tmp1 = load i64* %a, align 4 + ret i64 %tmp1 +} + +; CHECK-LABEL: define i64 @test_unaligned_read8(i64* %a) +; CHECK: call void @__tsan_func_entry(i8* %0) +; CHECK-NEXT: %1 = bitcast i64* %a to i8* +; CHECK-NEXT: call void @__tsan_unaligned_read8(i8* %1) +; CHECK-NEXT: %tmp1 = load i64* %a, align 4 +; CHECK-NEXT: call void @__tsan_func_exit() +; CHECK: ret i64 + +define i128 @test_unaligned_read16(i128* %a) sanitize_thread { +entry: + %tmp1 = load i128* %a, align 1 + ret i128 %tmp1 +} + +; CHECK-LABEL: define i128 @test_unaligned_read16(i128* %a) +; CHECK: call void @__tsan_func_entry(i8* %0) +; CHECK-NEXT: %1 = bitcast i128* %a to i8* +; CHECK-NEXT: call void @__tsan_unaligned_read16(i8* %1) +; CHECK-NEXT: %tmp1 = load i128* %a, align 1 +; CHECK-NEXT: call void @__tsan_func_exit() +; CHECK: ret i128 + +define i128 @test_aligned_read16(i128* %a) sanitize_thread { +entry: + %tmp1 = load i128* %a, align 8 + ret i128 %tmp1 +} + +; CHECK-LABEL: define i128 @test_aligned_read16(i128* %a) +; CHECK: call void @__tsan_func_entry(i8* %0) +; CHECK-NEXT: %1 = bitcast i128* %a to i8* +; CHECK-NEXT: call void @__tsan_read16(i8* %1) +; CHECK-NEXT: %tmp1 = load i128* %a, align 8 +; CHECK-NEXT: call void @__tsan_func_exit() +; CHECK: ret i128 + +define void @test_unaligned_write2(i16* %a) sanitize_thread { +entry: + store i16 1, i16* %a, align 1 + ret void +} + +; CHECK-LABEL: define void @test_unaligned_write2(i16* %a) +; CHECK: call void @__tsan_func_entry(i8* %0) +; CHECK-NEXT: %1 = bitcast i16* %a to i8* +; CHECK-NEXT: call void @__tsan_unaligned_write2(i8* %1) +; CHECK-NEXT: store i16 1, i16* %a, align 1 +; CHECK-NEXT: call void @__tsan_func_exit() +; CHECK: ret void + +define void @test_unaligned_write4(i32* %a) sanitize_thread { +entry: + store i32 1, i32* %a, align 1 + ret void +} + +; CHECK-LABEL: define void @test_unaligned_write4(i32* %a) +; CHECK: call void @__tsan_func_entry(i8* %0) +; CHECK-NEXT: %1 = bitcast i32* %a to i8* +; CHECK-NEXT: call void @__tsan_unaligned_write4(i8* %1) +; CHECK-NEXT: store i32 1, i32* %a, align 1 +; CHECK-NEXT: call void @__tsan_func_exit() +; CHECK: ret void + +define void @test_unaligned_write8(i64* %a) sanitize_thread { +entry: + store i64 1, i64* %a, align 1 + ret void +} + +; CHECK-LABEL: define void @test_unaligned_write8(i64* %a) +; CHECK: call void @__tsan_func_entry(i8* %0) +; CHECK-NEXT: %1 = bitcast i64* %a to i8* +; CHECK-NEXT: call void @__tsan_unaligned_write8(i8* %1) +; CHECK-NEXT: store i64 1, i64* %a, align 1 +; CHECK-NEXT: call void @__tsan_func_exit() +; CHECK: ret void + +define void @test_unaligned_write16(i128* %a) sanitize_thread { +entry: + store i128 1, i128* %a, align 1 + ret void +} + +; CHECK-LABEL: define void @test_unaligned_write16(i128* %a) +; CHECK: call void @__tsan_func_entry(i8* %0) +; CHECK-NEXT: %1 = bitcast i128* %a to i8* +; CHECK-NEXT: call void @__tsan_unaligned_write16(i8* %1) +; CHECK-NEXT: store i128 1, i128* %a, align 1 +; CHECK-NEXT: call void @__tsan_func_exit() +; CHECK: ret void + +define void @test_aligned_write16(i128* %a) sanitize_thread { +entry: + store i128 1, i128* %a, align 8 + ret void +} + +; CHECK-LABEL: define void @test_aligned_write16(i128* %a) +; CHECK: call void @__tsan_func_entry(i8* %0) +; CHECK-NEXT: %1 = bitcast i128* %a to i8* +; CHECK-NEXT: call void @__tsan_write16(i8* %1) +; CHECK-NEXT: store i128 1, i128* %a, align 8 +; CHECK-NEXT: call void @__tsan_func_exit() +; CHECK: ret void