[ASan] Initial support for Kernel AddressSanitizer

This patch adds initial support for the -fsanitize=kernel-address flag to Clang.
Right now it's quite restricted: only out-of-line instrumentation is supported, globals are not instrumented, some GCC kasan flags are not supported.
Using this patch I am able to build and boot the KASan tree with LLVMLinux patches from github.com/ramosian-glider/kasan/tree/kasan_llvmlinux.
To disable KASan instrumentation for a certain function attribute((no_sanitize("kernel-address"))) can be used.

llvm-svn: 240131

1 files changed, 4 insertions, 1 deletions

diff --git a/clang/lib/Driver/SanitizerArgs.cpp b/clang/lib/Driver/SanitizerArgs.cpp
index 9918fcbd5e1..4d27a393182 100644
--- a/clang/lib/Driver/SanitizerArgs.cpp
+++ b/clang/lib/Driver/SanitizerArgs.cpp
@@ -305,7 +305,10 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
   std::pair<SanitizerMask, SanitizerMask> IncompatibleGroups[] = {
       std::make_pair(Address, Thread), std::make_pair(Address, Memory),
       std::make_pair(Thread, Memory), std::make_pair(Leak, Thread),
-      std::make_pair(Leak, Memory)};
+      std::make_pair(Leak, Memory), std::make_pair(KernelAddress, Address),
+      std::make_pair(KernelAddress, Leak),
+      std::make_pair(KernelAddress, Thread),
+      std::make_pair(KernelAddress, Memory)};
   for (auto G : IncompatibleGroups) {
     SanitizerMask Group = G.first;
     if (Kinds & Group) {