2 files changed, 6 insertions, 9 deletions
diff --git a/llvm/lib/Analysis/InlineCost.cpp b/llvm/lib/Analysis/InlineCost.cpp
index ff31e81..5dce896 100644
--- a/llvm/lib/Analysis/InlineCost.cpp
+++ b/llvm/lib/Analysis/InlineCost.cpp
@@ -2898,15 +2898,6 @@ Optional<InlineResult> llvm::getAttributeBasedInliningDecision(
   if (Call.isNoInline())
     return InlineResult::failure("noinline call site attribute");
 
-  // Don't inline functions if one does not have any stack protector attribute
-  // but the other does.
-  if (Caller->hasStackProtectorFnAttr() && !Callee->hasStackProtectorFnAttr())
-    return InlineResult::failure(
-        "stack protected caller but callee requested no stack protector");
-  if (Callee->hasStackProtectorFnAttr() && !Caller->hasStackProtectorFnAttr())
-    return InlineResult::failure(
-        "stack protected callee but caller requested no stack protector");
-
   return None;
 }
 
diff --git a/llvm/lib/IR/Attributes.cpp b/llvm/lib/IR/Attributes.cpp
index 9726397..542b470 100644
--- a/llvm/lib/IR/Attributes.cpp
+++ b/llvm/lib/IR/Attributes.cpp
@@ -1921,6 +1921,12 @@ static void setOR(Function &Caller, const Function &Callee) {
 /// If the inlined function had a higher stack protection level than the
 /// calling function, then bump up the caller's stack protection level.
 static void adjustCallerSSPLevel(Function &Caller, const Function &Callee) {
+  // If the calling function has *no* stack protection level (e.g. it was built
+  // with Clang's -fno-stack-protector or no_stack_protector attribute), don't
+  // change it as that could change the program's semantics.
+  if (!Caller.hasStackProtectorFnAttr())
+    return;
+
   // If upgrading the SSP attribute, clear out the old SSP Attributes first.
   // Having multiple SSP attributes doesn't actually hurt, but it adds useless
   // clutter to the IR.