[tsan] Provide API for libraries for race detection on custom objects

This patch allows a non-instrumented library to call into TSan runtime, and tell us about "readonly" and "modifying" accesses to an arbitrary "object" and provide the caller and tag (type of object).  This allows TSan to detect violations of API threading contracts where "read-only" methods can be called simulatenously from multiple threads, while modifying methods must be exclusive.

Differential Revision: https://reviews.llvm.org/D28836



git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@293885 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 153 insertions, 0 deletions

diff --git a/test/tsan/Darwin/external.cc b/test/tsan/Darwin/external.cc
new file mode 100644
index 000000000..f1c6ebb80
--- /dev/null
+++ b/test/tsan/Darwin/external.cc
@@ -0,0 +1,153 @@
+// RUN: %clangxx_tsan %s -o %t-lib-instrumented.dylib              -shared -DSHARED_LIB
+// RUN: %clangxx_tsan %s -o %t-lib-noninstrumented.dylib           -shared -DSHARED_LIB -fno-sanitize=thread
+// RUN: %clangxx_tsan %s -o %t-lib-noninstrumented-callbacks.dylib -shared -DSHARED_LIB -fno-sanitize=thread -DUSE_TSAN_CALLBACKS
+// RUN: %clangxx_tsan %s %t-lib-instrumented.dylib -o %t-lib-instrumented
+// RUN: %clangxx_tsan %s %t-lib-noninstrumented.dylib -o %t-lib-noninstrumented
+// RUN: %clangxx_tsan %s %t-lib-noninstrumented-callbacks.dylib -o %t-lib-noninstrumented-callbacks
+
+// RUN: %deflake %run %t-lib-instrumented              2>&1 \
+// RUN:   | FileCheck %s --check-prefix=CHECK --check-prefix=TEST1
+// RUN:          %run %t-lib-noninstrumented           2>&1 \
+// RUN:   | FileCheck %s --check-prefix=CHECK --check-prefix=TEST2
+// RUN: %deflake %run %t-lib-noninstrumented-callbacks 2>&1 \
+// RUN:   | FileCheck %s --check-prefix=CHECK --check-prefix=TEST3
+
+#include <thread>
+
+#include <dlfcn.h>
+#include <pthread.h>
+#include <stdio.h>
+
+struct MyObject;
+typedef MyObject *MyObjectRef;
+extern "C" {
+  void InitializeLibrary();
+  MyObject *ObjectCreate();
+  long ObjectRead(MyObject *);
+  void ObjectWrite(MyObject *, long);
+  void ObjectWriteAnother(MyObject *, long);
+}
+
+#if defined(SHARED_LIB)
+
+struct MyObject {
+  long _val;
+  long _another;
+};
+
+#if defined(USE_TSAN_CALLBACKS)
+static void *tag;
+void *(*callback_register_tag)(const char *object_type);
+void *(*callback_assign_tag)(void *addr, void *tag);
+void (*callback_read)(void *addr, void *caller_pc, void *tag);
+void (*callback_write)(void *addr, void *caller_pc, void *tag);
+#endif
+
+void InitializeLibrary() {
+#if defined(USE_TSAN_CALLBACKS)
+  callback_register_tag = (decltype(callback_register_tag))dlsym(RTLD_DEFAULT, "__tsan_external_register_tag");
+  callback_assign_tag = (decltype(callback_assign_tag))dlsym(RTLD_DEFAULT, "__tsan_external_assign_tag");
+  callback_read = (decltype(callback_read))dlsym(RTLD_DEFAULT, "__tsan_external_read");
+  callback_write = (decltype(callback_write))dlsym(RTLD_DEFAULT, "__tsan_external_write");
+  tag = callback_register_tag("MyLibrary::MyObject");
+#endif
+}
+
+MyObject *ObjectCreate() {
+  MyObject *ref = (MyObject *)malloc(sizeof(MyObject));
+#if defined(USE_TSAN_CALLBACKS)
+  callback_assign_tag(ref, tag);
+#endif
+  return ref;
+}
+
+long ObjectRead(MyObject *ref) {
+#if defined(USE_TSAN_CALLBACKS)
+  callback_read(ref, __builtin_return_address(0), tag);
+#endif
+  return ref->_val;
+}
+
+void ObjectWrite(MyObject *ref, long val) {
+#if defined(USE_TSAN_CALLBACKS)
+  callback_write(ref, __builtin_return_address(0), tag);
+#endif
+  ref->_val = val;
+}
+
+void ObjectWriteAnother(MyObject *ref, long val) {
+#if defined(USE_TSAN_CALLBACKS)
+  callback_write(ref, __builtin_return_address(0), tag);
+#endif
+  ref->_another = val;
+}
+
+#else  // defined(SHARED_LIB)
+
+int main(int argc, char *argv[]) {
+  InitializeLibrary();
+  
+  {
+    MyObjectRef ref = ObjectCreate();
+    std::thread t1([ref]{ ObjectRead(ref); });
+    std::thread t2([ref]{ ObjectRead(ref); });
+    t1.join();
+    t2.join();
+  }
+  
+  // CHECK-NOT: WARNING: ThreadSanitizer
+  
+  fprintf(stderr, "RR test done\n");
+  // CHECK: RR test done
+
+  {
+    MyObjectRef ref = ObjectCreate();
+    std::thread t1([ref]{ ObjectRead(ref); });
+    std::thread t2([ref]{ ObjectWrite(ref, 66); });
+    t1.join();
+    t2.join();
+  }
+  
+  // TEST1: WARNING: ThreadSanitizer: data race
+  // TEST1: {{Write|Read}} of size 8 at
+  // TEST1: Previous {{write|read}} of size 8 at
+  // TEST1: Location is heap block of size 16 at
+  
+  // TEST2-NOT: WARNING: ThreadSanitizer
+  
+  // TEST3: WARNING: ThreadSanitizer: race on a library object
+  // TEST3: {{Mutating|read-only}} access of object MyLibrary::MyObject at
+  // TEST3: {{ObjectWrite|ObjectRead}}
+  // TEST3: Previous {{mutating|read-only}} access of object MyLibrary::MyObject at
+  // TEST3: {{ObjectWrite|ObjectRead}}
+  // TEST3: Location is MyLibrary::MyObject object of size 16 at
+  // TEST3: {{ObjectCreate}}
+
+  fprintf(stderr, "RW test done\n");
+  // CHECK: RW test done
+
+  {
+    MyObjectRef ref = ObjectCreate();
+    std::thread t1([ref]{ ObjectWrite(ref, 76); });
+    std::thread t2([ref]{ ObjectWriteAnother(ref, 77); });
+    t1.join();
+    t2.join();
+  }
+  
+  // TEST1-NOT: WARNING: ThreadSanitizer: data race
+  
+  // TEST2-NOT: WARNING: ThreadSanitizer
+  
+  // TEST3: WARNING: ThreadSanitizer: race on a library object
+  // TEST3: Mutating access of object MyLibrary::MyObject at
+  // TEST3: {{ObjectWrite|ObjectWriteAnother}}
+  // TEST3: Previous mutating access of object MyLibrary::MyObject at
+  // TEST3: {{ObjectWrite|ObjectWriteAnother}}
+  // TEST3: Location is MyLibrary::MyObject object of size 16 at
+  // TEST3: {{ObjectCreate}}
+
+  fprintf(stderr, "WW test done\n");
+  // CHECK: WW test done
+}
+
+#endif  // defined(SHARED_LIB)