From c83c81a62efd1fc8312630a9202761b785ac7eb2 Mon Sep 17 00:00:00 2001 From: Evgeniy Stepanov Date: Fri, 17 Oct 2014 23:29:44 +0000 Subject: [PATCH] [msan] Fix handling of byval arguments with large alignment. MSan param-tls slots are 8-byte aligned. This change clips alignment of memcpy into param-tls to 8. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220101 91177308-0d34-0410-b5e6-96231b3b80d8 --- .../Instrumentation/MemorySanitizer.cpp | 3 ++- .../MemorySanitizer/byval-alignment.ll | 20 +++++++++++++++++++ 2 files changed, 22 insertions(+), 1 deletion(-) create mode 100644 test/Instrumentation/MemorySanitizer/byval-alignment.ll diff --git a/lib/Transforms/Instrumentation/MemorySanitizer.cpp b/lib/Transforms/Instrumentation/MemorySanitizer.cpp index 3a311edf5e3..5a261c62f22 100644 --- a/lib/Transforms/Instrumentation/MemorySanitizer.cpp +++ b/lib/Transforms/Instrumentation/MemorySanitizer.cpp @@ -2329,7 +2329,8 @@ struct MemorySanitizerVisitor : public InstVisitor { assert(A->getType()->isPointerTy() && "ByVal argument is not a pointer!"); Size = MS.DL->getTypeAllocSize(A->getType()->getPointerElementType()); - unsigned Alignment = CS.getParamAlignment(i + 1); + unsigned ParamAlignment = CS.getParamAlignment(i + 1); + unsigned Alignment = std::min(ParamAlignment, kShadowTLSAlignment); Store = IRB.CreateMemCpy(ArgShadowBase, getShadowPtr(A, Type::getInt8Ty(*MS.C), IRB), Size, Alignment); diff --git a/test/Instrumentation/MemorySanitizer/byval-alignment.ll b/test/Instrumentation/MemorySanitizer/byval-alignment.ll new file mode 100644 index 00000000000..43e204a6a96 --- /dev/null +++ b/test/Instrumentation/MemorySanitizer/byval-alignment.ll @@ -0,0 +1,20 @@ +; Test that copy alignment for byval arguments is limited by param-tls slot alignment. + +; RUN: opt < %s -msan -msan-check-access-address=0 -S | FileCheck %s + +target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-unknown-linux-gnu" + +%struct.S = type { i64, i64, i64, [8 x i8] } + +; CHECK: [[A:%.*]] = bitcast i64* {{.*}} add {{.*}} ptrtoint {{.*}} @__msan_param_tls {{.*}} i64 8) +; CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* [[A]], i8* {{.*}}, i64 32, i32 8, i1 false) + +define void @Caller() sanitize_memory { +entry: + %agg.tmp = alloca %struct.S, align 16 + call void @Callee(i32 1, %struct.S* byval align 16 %agg.tmp) + ret void +} + +declare void @Callee(i32, %struct.S* byval align 16) -- 2.34.1