[asan] Fix size/alignment issues with non-default shadow scale
Fix a couple places where the minimum alignment/size should be a
function of the shadow granularity:
- alignment of AllGlobals
- the minimum left redzone size on the stack
Added a test to verify that the metadata_array is properly aligned
for shadow scale of 5, to be enabled when we add build support
for testing shadow scale of 5.
Differential Revision: https://reviews.llvm.org/D39470
llvm-svn: 318395
diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index 967464f..190efce2 100644
--- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -1978,6 +1978,8 @@
auto AllGlobals = new GlobalVariable(
M, ArrayOfGlobalStructTy, false, GlobalVariable::InternalLinkage,
ConstantArray::get(ArrayOfGlobalStructTy, MetadataInitializers), "");
+ if (Mapping.Scale > 3)
+ AllGlobals->setAlignment(1ULL << Mapping.Scale);
IRB.CreateCall(AsanRegisterGlobals,
{IRB.CreatePointerCast(AllGlobals, IntptrTy),
@@ -2817,9 +2819,10 @@
// Minimal header size (left redzone) is 4 pointers,
// i.e. 32 bytes on 64-bit platforms and 16 bytes in 32-bit platforms.
- size_t MinHeaderSize = ASan.LongSize / 2;
+ size_t Granularity = 1ULL << Mapping.Scale;
+ size_t MinHeaderSize = std::max((size_t)ASan.LongSize / 2, Granularity);
const ASanStackFrameLayout &L =
- ComputeASanStackFrameLayout(SVD, 1ULL << Mapping.Scale, MinHeaderSize);
+ ComputeASanStackFrameLayout(SVD, Granularity, MinHeaderSize);
// Build AllocaToSVDMap for ASanStackVariableDescription lookup.
DenseMap<const AllocaInst *, ASanStackVariableDescription *> AllocaToSVDMap;