commit 2a3723ef114d467179d463539dd73974b87ccf85
author Evgenii Stepanov <eugenis@google.com> Thu Feb 27 15:43:53 2020 -0800
committer Evgenii Stepanov <eugenis@google.com> Mon Mar 16 16:35:25 2020 -0700
tree 6311cd9b5af66f31c0695c8e707ec0e46d520e53
parent 78ce190803c921e62bc159b27bf694a7d1d56d19

[memtag] Plug in stack safety analysis.

Summary:
Run StackSafetyAnalysis at the end of the IR pipeline and annotate
proven safe allocas with !stack-safe metadata. Do not instrument such
allocas in the AArch64StackTagging pass.

Reviewers: pcc, vitalybuka, ostannard

Reviewed By: vitalybuka

Subscribers: merge_guards_bot, kristof.beyls, hiraditya, cfe-commits, gilang, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D73513

clang/lib/CodeGen/BackendUtil.cpp

diff --git a/clang/lib/CodeGen/BackendUtil.cpp b/clang/lib/CodeGen/BackendUtil.cpp
index b6ca46e7..28e4ecc 100644
--- a/clang/lib/CodeGen/BackendUtil.cpp
+++ b/clang/lib/CodeGen/BackendUtil.cpp
@@ -18,6 +18,7 @@
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/ADT/Triple.h"
+#include "llvm/Analysis/StackSafetyAnalysis.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/Analysis/TargetTransformInfo.h"
 #include "llvm/Bitcode/BitcodeReader.h"
@@ -345,6 +346,11 @@
   PM.add(createDataFlowSanitizerPass(LangOpts.SanitizerBlacklistFiles));
 }
 
+static void addMemTagOptimizationPasses(const PassManagerBuilder &Builder,
+                                        legacy::PassManagerBase &PM) {
+  PM.add(createStackSafetyGlobalInfoWrapperPass(/*SetMetadata=*/true));
+}
+
 static TargetLibraryInfoImpl *createTLII(llvm::Triple &TargetTriple,
                                          const CodeGenOptions &CodeGenOpts) {
   TargetLibraryInfoImpl *TLII = new TargetLibraryInfoImpl(TargetTriple);
@@ -696,6 +702,11 @@
                            addDataFlowSanitizerPass);
   }
 
+  if (LangOpts.Sanitize.has(SanitizerKind::MemTag)) {
+    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
+                           addMemTagOptimizationPasses);
+  }
+
   // Set up the per-function pass manager.
   FPM.add(new TargetLibraryInfoWrapperPass(*TLII));
   if (CodeGenOpts.VerifyModule)
@@ -1300,6 +1311,11 @@
           /*CompileKernel=*/true, /*Recover=*/true));
     }
 
+    if (CodeGenOpts.OptimizationLevel > 0 &&
+        LangOpts.Sanitize.has(SanitizerKind::MemTag)) {
+      MPM.addPass(StackSafetyGlobalAnnotatorPass());
+    }
+
     if (CodeGenOpts.OptimizationLevel == 0) {
       addCoroutinePassesAtO0(MPM, LangOpts, CodeGenOpts);
       addSanitizersAtO0(MPM, TargetTriple, LangOpts, CodeGenOpts);