[hwasan] also omit safe mem[cpy|mov|set].

Reviewed By: eugenis

Differential Revision: https://reviews.llvm.org/D109816

1 files changed, 12 insertions, 10 deletions

diff --git a/llvm/lib/Analysis/StackSafetyAnalysis.cpp b/llvm/lib/Analysis/StackSafetyAnalysis.cpp
index 0e981d1..44f8a18 100644
--- a/llvm/lib/Analysis/StackSafetyAnalysis.cpp
+++ b/llvm/lib/Analysis/StackSafetyAnalysis.cpp
@@ -230,7 +230,7 @@ struct StackSafetyInfo::InfoTy {
 struct StackSafetyGlobalInfo::InfoTy {
   GVToSSI Info;
   SmallPtrSet<const AllocaInst *, 8> SafeAllocas;
-  SmallPtrSet<const Instruction *, 8> SafeAccesses;
+  std::map<const Instruction *, bool> AccessIsUnsafe;
 };
 
 namespace {
@@ -820,7 +820,6 @@ const StackSafetyGlobalInfo::InfoTy &StackSafetyGlobalInfo::getInfo() const {
     Info.reset(new InfoTy{
         createGlobalStackSafetyInfo(std::move(Functions), Index), {}, {}});
 
-    std::map<const Instruction *, bool> AccessIsUnsafe;
     for (auto &FnKV : Info->Info) {
       for (auto &KV : FnKV.second.Allocas) {
         ++NumAllocaTotal;
@@ -831,14 +830,10 @@ const StackSafetyGlobalInfo::InfoTy &StackSafetyGlobalInfo::getInfo() const {
           ++NumAllocaStackSafe;
         }
         for (const auto &A : KV.second.Accesses)
-          AccessIsUnsafe[A.first] |= !AIRange.contains(A.second);
+          Info->AccessIsUnsafe[A.first] |= !AIRange.contains(A.second);
       }
     }
 
-    for (const auto &KV : AccessIsUnsafe)
-      if (!KV.second)
-        Info->SafeAccesses.insert(KV.first);
-
     if (StackSafetyPrint)
       print(errs());
   }
@@ -908,9 +903,13 @@ bool StackSafetyGlobalInfo::isSafe(const AllocaInst &AI) const {
   return Info.SafeAllocas.count(&AI);
 }
 
-bool StackSafetyGlobalInfo::accessIsSafe(const Instruction &I) const {
+bool StackSafetyGlobalInfo::stackAccessIsSafe(const Instruction &I) const {
   const auto &Info = getInfo();
-  return Info.SafeAccesses.count(&I);
+  auto It = Info.AccessIsUnsafe.find(&I);
+  if (It == Info.AccessIsUnsafe.end()) {
+    return true;
+  }
+  return !It->second;
 }
 
 void StackSafetyGlobalInfo::print(raw_ostream &O) const {
@@ -924,7 +923,10 @@ void StackSafetyGlobalInfo::print(raw_ostream &O) const {
       O << "    safe accesses:"
         << "\n";
       for (const auto &I : instructions(F)) {
-        if (accessIsSafe(I)) {
+        const CallInst *Call = dyn_cast<CallInst>(&I);
+        if ((isa<StoreInst>(I) || isa<LoadInst>(I) || isa<MemIntrinsic>(I) ||
+             (Call && Call->hasByValArgument())) &&
+            stackAccessIsSafe(I)) {
           O << "     " << I << "\n";
         }
       }