[PATCH] D45487: [tsan] Add interceptors for objc_sync_enter and objc_sync_exit

[Kuba (Brecka) Mracek via Phabricator via llvm-commits]

kubamracek created this revision.
kubamracek added reviewers: dvyukov, delcypher, george.karpenkov.
kubamracek added a project: Sanitizers.
Herald added subscribers: Sanitizers, mgorny.

Objective-C's `@synchronize` synchronization primitive uses calls to objc_sync_enter and objc_sync_exit runtime functions. In most cases, they end up just calling pthread_mutex_lock/pthread_mutex_unlock, but there are some cases where the synchronization from pthread_mutex_lock/pthread_mutex_unlock interceptors isn't enough. Let's add explicit interceptors for objc_sync_enter and objc_sync_exit to handle all cases.


Repository:
  rCRT Compiler Runtime

https://reviews.llvm.org/D45487

Files:
  lib/tsan/CMakeLists.txt
  lib/tsan/rtl/tsan_interceptors_mac.cc


Index: lib/tsan/rtl/tsan_interceptors_mac.cc
===================================================================
--- lib/tsan/rtl/tsan_interceptors_mac.cc
+++ lib/tsan/rtl/tsan_interceptors_mac.cc
@@ -294,6 +294,19 @@
 
 #endif  // #if defined(__has_include) && __has_include(<xpc/xpc.h>)
 
+TSAN_INTERCEPTOR(int, objc_sync_enter, void *obj) {
+  SCOPED_TSAN_INTERCEPTOR(objc_sync_enter, obj);
+  int result = REAL(objc_sync_enter)(obj);
+  if (obj) Acquire(thr, pc, (uptr)obj);
+  return result;
+}
+
+TSAN_INTERCEPTOR(int, objc_sync_exit, void *obj) {
+  SCOPED_TSAN_INTERCEPTOR(objc_sync_enter, obj);
+  if (obj) Release(thr, pc, (uptr)obj);
+  return REAL(objc_sync_exit)(obj);
+}
+
 // On macOS, libc++ is always linked dynamically, so intercepting works the
 // usual way.
 #define STDCXX_INTERCEPTOR TSAN_INTERCEPTOR
Index: lib/tsan/CMakeLists.txt
===================================================================
--- lib/tsan/CMakeLists.txt
+++ lib/tsan/CMakeLists.txt
@@ -118,7 +118,7 @@
                 RTUbsan
     CFLAGS ${TSAN_RTL_CFLAGS}
     LINK_FLAGS ${SANITIZER_COMMON_LINK_FLAGS} ${WEAK_SYMBOL_LINK_FLAGS}
-    LINK_LIBS ${TSAN_LINK_LIBS}
+    LINK_LIBS ${TSAN_LINK_LIBS} objc
     PARENT_TARGET tsan)
   add_compiler_rt_object_libraries(RTTsan_dynamic
     OS ${TSAN_SUPPORTED_OS}


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