[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, 6 insertions, 3 deletions

diff --git a/clang/lib/CodeGen/SanitizerMetadata.cpp b/clang/lib/CodeGen/SanitizerMetadata.cpp
index 7c38b2807e9..2a338bac4b4 100644
--- a/clang/lib/CodeGen/SanitizerMetadata.cpp
+++ b/clang/lib/CodeGen/SanitizerMetadata.cpp
@@ -25,7 +25,8 @@ void SanitizerMetadata::reportGlobalToASan(llvm::GlobalVariable *GV,
                                            SourceLocation Loc, StringRef Name,
                                            QualType Ty, bool IsDynInit,
                                            bool IsBlacklisted) {
-  if (!CGM.getLangOpts().Sanitize.has(SanitizerKind::Address))
+  if (!CGM.getLangOpts().Sanitize.hasOneOf(SanitizerKind::Address |
+                                           SanitizerKind::KernelAddress))
     return;
   IsDynInit &= !CGM.isInSanitizerBlacklist(GV, Loc, Ty, "init");
   IsBlacklisted |= CGM.isInSanitizerBlacklist(GV, Loc, Ty);
@@ -56,7 +57,8 @@ void SanitizerMetadata::reportGlobalToASan(llvm::GlobalVariable *GV,
 
 void SanitizerMetadata::reportGlobalToASan(llvm::GlobalVariable *GV,
                                            const VarDecl &D, bool IsDynInit) {
-  if (!CGM.getLangOpts().Sanitize.has(SanitizerKind::Address))
+  if (!CGM.getLangOpts().Sanitize.hasOneOf(SanitizerKind::Address |
+                                           SanitizerKind::KernelAddress))
     return;
   std::string QualName;
   llvm::raw_string_ostream OS(QualName);
@@ -67,7 +69,8 @@ void SanitizerMetadata::reportGlobalToASan(llvm::GlobalVariable *GV,
 void SanitizerMetadata::disableSanitizerForGlobal(llvm::GlobalVariable *GV) {
   // For now, just make sure the global is not modified by the ASan
   // instrumentation.
-  if (CGM.getLangOpts().Sanitize.has(SanitizerKind::Address))
+  if (CGM.getLangOpts().Sanitize.hasOneOf(SanitizerKind::Address |
+                                          SanitizerKind::KernelAddress))
     reportGlobalToASan(GV, SourceLocation(), "", QualType(), false, true);
 }