[sanitizers] Add DFSan support for AArch64 42-bit VMA

This patch adds support for dfsan on aarch64-linux with 42-bit VMA
(current default config for 64K pagesize kernels).  The support is
enabled by defining the SANITIZER_AARCH64_VMA to 42 at build time
for both clang/llvm and compiler-rt.  The default VMA is 39 bits.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@245840 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp b/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
index 8344e087a9593ad4ee922d190981b935d08b6616..c613f2577a688ae6fdc90d47afc6cd2b3f6be874 100644 (file)
--- a/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
+++ b/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
@@ -72,6 +72,16 @@
 
 using namespace llvm;
 
+// VMA size definition for architecture that support multiple sizes.
+// AArch64 has 3 VMA sizes: 39, 42 and 48.
+#ifndef SANITIZER_AARCH64_VMA
+# define SANITIZER_AARCH64_VMA 39
+#else
+# if SANITIZER_AARCH64_VMA != 39 && SANITIZER_AARCH64_VMA != 42
+#  error "invalid SANITIZER_AARCH64_VMA size"
+# endif
+#endif
+
 // The -dfsan-preserve-alignment flag controls whether this pass assumes that
 // alignment requirements provided by the input IR are correct.  For example,
 // if the input IR contains a load with alignment 8, this flag will cause
@@ -437,7 +447,11 @@ bool DataFlowSanitizer::doInitialization(Module &M) {
   else if (IsMIPS64)
     ShadowPtrMask = ConstantInt::getSigned(IntptrTy, ~0xF000000000LL);
   else if (IsAArch64)
+#if SANITIZER_AARCH64_VMA == 39
     ShadowPtrMask = ConstantInt::getSigned(IntptrTy, ~0x7800000000LL);
+#else
+    ShadowPtrMask = ConstantInt::getSigned(IntptrTy, ~0x3c000000000LL);
+#endif
   else
     report_fatal_error("unsupported triple");