maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

[MSan] [X86] Fix vararg helper for fixed arguments in overflow area. 

This fixes http://llvm.org/PR27646 on x86_64.

Differential Revision: http://reviews.llvm.org/D19997

llvm-svn: 268783
This commit is contained in:
Marcin Koscielnicki 2016-05-06 19:36:56 +00:00
parent 144eafd9ee
commit b088ad1e09
2 changed files with 12 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
View File

@ -2891,9 +2891,14 @@ struct VarArgAMD64Helper : public VarArgHelper {
ArgIt != End; ++ArgIt) {
Value *A = *ArgIt;
unsigned ArgNo = CS.getArgumentNo(ArgIt);
bool IsFixed = ArgNo < CS.getFunctionType()->getNumParams();
bool IsByVal = CS.paramHasAttr(ArgNo + 1, Attribute::ByVal);
if (IsByVal) {
// ByVal arguments always go to the overflow area.
// Fixed arguments passed through the overflow area will be stepped
// over by va_start, so don't count them towards the offset.
if (IsFixed)
continue;
assert(A->getType()->isPointerTy());
Type *RealTy = A->getType()->getPointerElementType();
uint64_t ArgSize = DL.getTypeAllocSize(RealTy);
@ -2918,10 +2923,16 @@ struct VarArgAMD64Helper : public VarArgHelper {
FpOffset += 16;
break;
case AK_Memory:
if (IsFixed)
continue;
uint64_t ArgSize = DL.getTypeAllocSize(A->getType());
Base = getShadowPtrForVAArgument(A->getType(), IRB, OverflowOffset);
OverflowOffset += alignTo(ArgSize, 8);
}
// Take fixed arguments into account for GpOffset and FpOffset,
// but don't actually store shadows for them.
if (IsFixed)
continue;
IRB.CreateAlignedStore(MSV.getShadow(A), Base, kShadowTLSAlignment);
}
}

3
llvm/test/Instrumentation/MemorySanitizer/msan_basic.ll
View File

@ -914,8 +914,7 @@ entry:
; the third struct goes to the overflow area byval
; CHECK-LABEL: @VAArgStruct
; undef
; CHECK: store i32 -1, i32* {{.*}}@__msan_va_arg_tls {{.*}}, align 8
; undef not stored to __msan_va_arg_tls - it's a fixed argument
; first struct through general purpose registers
; CHECK: store i64 {{.*}}, i64* {{.*}}@__msan_va_arg_tls{{.*}}, i64 8){{.*}}, align 8
; CHECK: store i64 {{.*}}, i64* {{.*}}@__msan_va_arg_tls{{.*}}, i64 16){{.*}}, align 8