ARM MTE stack sanitizer.

Add "memtag" sanitizer that detects and mitigates stack memory issues
using armv8.5 Memory Tagging Extension.

It is similar in principle to HWASan, which is a software implementation
of the same idea, but there are enough differencies to warrant a new
sanitizer type IMHO. It is also expected to have very different
performance properties.

The new sanitizer does not have a runtime library (it may grow one
later, along with a "debugging" mode). Similar to SafeStack and
StackProtector, the instrumentation pass (in a follow up change) will be
inserted in all cases, but will only affect functions marked with the
new sanitize_memtag attribute.

Reviewers: pcc, hctim, vitalybuka, ostannard

Subscribers: srhines, mehdi_amini, javed.absar, kristof.beyls, hiraditya, cryptoad, steven_wu, dexonsmith, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D64169

llvm-svn: 366123

1 files changed, 4 insertions, 2 deletions

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index ba501d645c2c..7ab960e8bcee 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -2239,9 +2239,11 @@ bool CodeGenModule::isInSanitizerBlacklist(llvm::GlobalVariable *GV,
                                            SourceLocation Loc, QualType Ty,
                                            StringRef Category) const {
   // For now globals can be blacklisted only in ASan and KASan.
-  const SanitizerMask EnabledAsanMask = LangOpts.Sanitize.Mask &
+  const SanitizerMask EnabledAsanMask =
+      LangOpts.Sanitize.Mask &
       (SanitizerKind::Address | SanitizerKind::KernelAddress |
-       SanitizerKind::HWAddress | SanitizerKind::KernelHWAddress);
+       SanitizerKind::HWAddress | SanitizerKind::KernelHWAddress |
+       SanitizerKind::MemTag);
   if (!EnabledAsanMask)
     return false;
   const auto &SanitizerBL = getContext().getSanitizerBlacklist();