[sanitizer] Intercept __pthread_mutex_lock and __pthread_mutex_unlock

[dvyukov]

Interesting. Who calls these functions? Why? Can we change them to call normal functions instead?

In pthread they are no more than aliases to normal functions, can we do it with aliases too? like we do it for __libc_mutex_lock:

sanitizer_common/sanitizer_common_interceptors.inc-INTERCEPTOR(int, __libc_mutex_lock, void *m) \
sanitizer_common/sanitizer_common_interceptors.inc: ALIAS(WRAPPER_NAME(pthread_mutex_lock));

[vitalybuka]

In D46793#1096839, @dvyukov wrote:

Interesting. Who calls these functions? Why? Can we change them to call normal functions instead?

I've cc'd you on the internal bug.

In pthread they are no more than aliases to normal functions, can we do it with aliases too? like we do it for __libc_mutex_lock:

sanitizer_common/sanitizer_common_interceptors.inc-INTERCEPTOR(int, __libc_mutex_lock, void *m) \
sanitizer_common/sanitizer_common_interceptors.inc: ALIAS(WRAPPER_NAME(pthread_mutex_lock));

Alias version works.

[vitalybuka]

use alias

[vitalybuka]

rebase

[vitalybuka]

Fix tsan tests

[vitalybuka]

I need to fall back to "return WRAP(pthread_mutex_lock)(m)"
I've forgot to rerun tsan tests with ALIAS. With ALIAS stacks became __pthread_mutex_lock for regular pthread_mutex_lock calls which breaks some tests.

[eugenis]

LGTM

lib/sanitizer_common/sanitizer_common_interceptors.inc

 #define INIT_PTHREAD_MUTEX_LOCK COMMON_INTERCEPT_FUNCTION(pthread_mutex_lock)
 #define INIT_PTHREAD_MUTEX_UNLOCK \
   COMMON_INTERCEPT_FUNCTION(pthread_mutex_unlock)
 #else
 #define INIT_PTHREAD_MUTEX_LOCK
 #define INIT_PTHREAD_MUTEX_UNLOCK
 #endif
 
+#if SANITIZER_INTERCEPT___PTHREAD_MUTEX
+INTERCEPTOR(int, __pthread_mutex_lock, void *m) {
+  return WRAP(pthread_mutex_lock)(m);
+}
+
+INTERCEPTOR(int, __pthread_mutex_unlock, void *m) {
+  return WRAP(pthread_mutex_unlock)(m);
+}
+
+#define INIT___PTHREAD_MUTEX_LOCK \
+  COMMON_INTERCEPT_FUNCTION(__pthread_mutex_lock)
+#define INIT___PTHREAD_MUTEX_UNLOCK \
+  COMMON_INTERCEPT_FUNCTION(__pthread_mutex_unlock)
+#else
+#define INIT___PTHREAD_MUTEX_LOCK
+#define INIT___PTHREAD_MUTEX_UNLOCK
+#endif
+
 #if SANITIZER_INTERCEPT___LIBC_MUTEX
 INTERCEPTOR(int, __libc_mutex_lock, void *m)
 ALIAS(WRAPPER_NAME(pthread_mutex_lock));
 
 INTERCEPTOR(int, __libc_mutex_unlock, void *m)
 ALIAS(WRAPPER_NAME(pthread_mutex_unlock));
 
 INTERCEPTOR(int, __libc_thr_setcancelstate, int state, int *oldstate)
static void InitializeCommonInterceptors() {
   INIT_SIGTIMEDWAIT;
   INIT_SIGSETOPS;
   INIT_SIGPENDING;
   INIT_SIGPROCMASK;
   INIT_BACKTRACE;
   INIT__EXIT;
   INIT_PTHREAD_MUTEX_LOCK;
   INIT_PTHREAD_MUTEX_UNLOCK;
+  INIT___PTHREAD_MUTEX_LOCK;
+  INIT___PTHREAD_MUTEX_UNLOCK;
   INIT___LIBC_MUTEX_LOCK;
   INIT___LIBC_MUTEX_UNLOCK;
   INIT___LIBC_THR_SETCANCELSTATE;
   INIT_GETMNTENT;
   INIT_GETMNTENT_R;
   INIT_STATFS;
   INIT_STATFS64;
   INIT_STATVFS;

lib/sanitizer_common/sanitizer_platform_interceptors.h

 // FIXME: getline seems to be available on OSX 10.7
 #define SANITIZER_INTERCEPT_GETLINE \
   (SI_FREEBSD || SI_NETBSD || SI_OPENBSD || SI_LINUX_NOT_ANDROID || SI_SOLARIS)
 
 #define SANITIZER_INTERCEPT__EXIT \
   (SI_LINUX || SI_FREEBSD || SI_NETBSD || SI_OPENBSD || SI_MAC || SI_SOLARIS)
 
 #define SANITIZER_INTERCEPT_PTHREAD_MUTEX SI_POSIX
+#define SANITIZER_INTERCEPT___PTHREAD_MUTEX SI_LINUX_NOT_ANDROID
 #define SANITIZER_INTERCEPT___LIBC_MUTEX SI_NETBSD
 #define SANITIZER_INTERCEPT_PTHREAD_SETNAME_NP \
   (SI_FREEBSD || SI_NETBSD || SI_OPENBSD || SI_LINUX_NOT_ANDROID || SI_SOLARIS)
 #define SANITIZER_INTERCEPT_PTHREAD_GETNAME_NP \
   (SI_FREEBSD || SI_LINUX_NOT_ANDROID || SI_SOLARIS)
 
 #define SANITIZER_INTERCEPT_TLS_GET_ADDR \
   (SI_FREEBSD || SI_NETBSD || SI_OPENBSD || SI_LINUX_NOT_ANDROID || SI_SOLARIS)

test/sanitizer_common/TestCases/Linux/pthread_mutex.cc

+// RUN: %clangxx -O1 %s -o %t && %run %t
+// RUN: %clangxx -O1 -DUSE_GLIBC %s -o %t && %run %t
+// UNSUPPORTED: android
+
+#include <pthread.h>
+
+#ifdef USE_GLIBC
+extern "C" int __pthread_mutex_lock(pthread_mutex_t *__mutex);
+extern "C" int __pthread_mutex_unlock(pthread_mutex_t *__mutex);
+#define LOCK __pthread_mutex_lock
+#define UNLOCK __pthread_mutex_unlock
+#else
+#define LOCK pthread_mutex_lock
+#define UNLOCK pthread_mutex_unlock
+#endif
+
+pthread_mutex_t m = PTHREAD_MUTEX_INITIALIZER;
+int x;
+
+static void *Start(void *arg) {
+  LOCK(&m);
+  ++x;
+  UNLOCK(&m);
+  return nullptr;
+}
+
+int main() {
+  pthread_t threads[2] = {};
+  for (pthread_t &t : threads)
+    pthread_create(&t, 0, &Start, 0);
+  for (pthread_t &t : threads)
+    pthread_join(t, 0);
+  return 0;
+}