Index: lib/CodeGen/CodeGenFunction.cpp
===================================================================
--- lib/CodeGen/CodeGenFunction.cpp
+++ lib/CodeGen/CodeGenFunction.cpp
@@ -714,6 +714,13 @@
   if (SanOpts.has(SanitizerKind::SafeStack))
     Fn->addFnAttr(llvm::Attribute::SafeStack);
 
+  // Ignore TSan memory acesses from within dealloc and all of its calees at
+  // run time.
+  if (SanOpts.has(SanitizerKind::Thread))
+    if (const auto *M = dyn_cast_or_null<ObjCMethodDecl>(D))
+      if (M->getMethodFamily() == OMF_dealloc)
+        Fn->addFnAttr("sanitize_thread_no_checking_at_run_time");
+
   // Apply xray attributes to the function (as a string, for now)
   if (D && ShouldXRayInstrumentFunction()) {
     if (const auto *XRayAttr = D->getAttr<XRayInstrumentAttr>()) {
Index: test/CodeGen/sanitize-thread-attr-dealloc.m
===================================================================
--- /dev/null
+++ test/CodeGen/sanitize-thread-attr-dealloc.m
@@ -0,0 +1,23 @@
+// RUN: %clang_cc1 -triple x86_64-apple-darwin -emit-llvm -o - %s | FileCheck -check-prefix=WITHOUT %s
+// RUN: %clang_cc1 -triple x86_64-apple-darwin -emit-llvm -o - %s -fsanitize=thread | FileCheck -check-prefix=TSAN %s
+
+__attribute__((objc_root_class))
+@interface NSObject
+- (void)dealloc;
+@end
+
+@interface MyObject : NSObject
+- (void) dealloc;
+@end
+
+@implementation MyObject
+- (void)dealloc {
+  [super dealloc];
+}
+@end
+
+// WITHOUT-NOT: "sanitize_thread_no_checking_at_run_time"
+
+// TSAN: dealloc{{.*}}) [[ATTR:#[0-9]+]]
+// TSAN: attributes [[ATTR]] = { nounwind sanitize_thread {{.*}} "sanitize_thread_no_checking_at_run_time" {{.*}} }
+