[Sanitizer] Add interceptor for pthread_sigmask

Summary:
pthread_sigmask is just like sigprocmask, except that its behavior in
multithreaded programs is explicitly specified. Sanitizers were lacking
a common interceptor for pthread_sigmask (although some specific
sanitizers defined custom version), which lead to false positives
(at least in msan) when using this function.

The interceptor implementation, and its test are based on the equivalent
code for sigprocmask.

Reviewers: eugenis, vitalybuka

Subscribers: kubamracek, delcypher, jfb, jdoerfert, llvm-commits, #sanitizers

Tags: #llvm, #sanitizers

Differential Revision: https://reviews.llvm.org/D58382

llvm-svn: 354874

5 files changed, 31 insertions, 0 deletions

diff --git a/compiler-rt/lib/esan/esan_interceptors.cpp b/compiler-rt/lib/esan/esan_interceptors.cpp
index 2f454f07ca7..1e8e67c4bb3 100644
--- a/compiler-rt/lib/esan/esan_interceptors.cpp
+++ b/compiler-rt/lib/esan/esan_interceptors.cpp
@@ -45,6 +45,7 @@ DECLARE_REAL_AND_INTERCEPTOR(void *, malloc, uptr)
 
 // We provide our own version:
 #undef SANITIZER_INTERCEPT_SIGPROCMASK
+#undef SANITIZER_INTERCEPT_PTHREAD_SIGMASK
 
 #define COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED (!EsanIsInitialized)
 
diff --git a/compiler-rt/lib/msan/tests/msan_test.cc b/compiler-rt/lib/msan/tests/msan_test.cc
index 4bac6f92a72..a3a98301c64 100644
--- a/compiler-rt/lib/msan/tests/msan_test.cc
+++ b/compiler-rt/lib/msan/tests/msan_test.cc
@@ -2579,6 +2579,14 @@ TEST(MemorySanitizer, sigprocmask) {
   EXPECT_NOT_POISONED(s);
 }
 
+TEST(MemorySanitizer, pthread_sigmask) {
+  sigset_t s;
+  EXPECT_POISONED(s);
+  int res = pthread_sigmask(SIG_BLOCK, 0, &s);
+  ASSERT_EQ(0, res);
+  EXPECT_NOT_POISONED(s);
+}
+
 struct StructWithDtor {
   ~StructWithDtor();
 };
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
index 6e0538d5cee..5e0be8bb7d0 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
@@ -4036,6 +4036,25 @@ INTERCEPTOR(int, sigprocmask, int how, __sanitizer_sigset_t *set,
 #define INIT_SIGPROCMASK
 #endif
 
+#if SANITIZER_INTERCEPT_PTHREAD_SIGMASK
+INTERCEPTOR(int, pthread_sigmask, int how, __sanitizer_sigset_t *set,
+            __sanitizer_sigset_t *oldset) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, pthread_sigmask, how, set, oldset);
+  if (set) COMMON_INTERCEPTOR_READ_RANGE(ctx, set, sizeof(*set));
+  // FIXME: under ASan the call below may write to freed memory and corrupt
+  // its metadata. See
+  // https://github.com/google/sanitizers/issues/321.
+  int res = REAL(pthread_sigmask)(how, set, oldset);
+  if (!res && oldset)
+    COMMON_INTERCEPTOR_WRITE_RANGE(ctx, oldset, sizeof(*oldset));
+  return res;
+}
+#define INIT_PTHREAD_SIGMASK COMMON_INTERCEPT_FUNCTION(pthread_sigmask);
+#else
+#define INIT_PTHREAD_SIGMASK
+#endif
+
 #if SANITIZER_INTERCEPT_BACKTRACE
 INTERCEPTOR(int, backtrace, void **buffer, int size) {
   void *ctx;
@@ -9595,6 +9614,7 @@ static void InitializeCommonInterceptors() {
   INIT_SIGSETOPS;
   INIT_SIGPENDING;
   INIT_SIGPROCMASK;
+  INIT_PTHREAD_SIGMASK;
   INIT_BACKTRACE;
   INIT__EXIT;
   INIT_PTHREAD_MUTEX_LOCK;
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h b/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h
index b49eb555a5e..9c71714fa1b 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h
@@ -311,6 +311,7 @@
   (SI_FREEBSD || SI_NETBSD || SI_MAC || SI_LINUX_NOT_ANDROID || SI_SOLARIS)
 #define SANITIZER_INTERCEPT_SIGPENDING SI_POSIX
 #define SANITIZER_INTERCEPT_SIGPROCMASK SI_POSIX
+#define SANITIZER_INTERCEPT_PTHREAD_SIGMASK SI_POSIX
 #define SANITIZER_INTERCEPT_BACKTRACE \
   (SI_FREEBSD || SI_NETBSD || SI_OPENBSD || SI_LINUX_NOT_ANDROID || SI_SOLARIS)
 #define SANITIZER_INTERCEPT_GETMNTENT SI_LINUX
diff --git a/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc b/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc
index e4b8def7831..9ea7d89b403 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc
+++ b/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc
@@ -2221,6 +2221,7 @@ static void HandleRecvmsg(ThreadState *thr, uptr pc,
 #define NEED_TLS_GET_ADDR
 #endif
 #undef SANITIZER_INTERCEPT_TLS_GET_ADDR
+#undef SANITIZER_INTERCEPT_PTHREAD_SIGMASK
 
 #define COMMON_INTERCEPT_FUNCTION(name) INTERCEPT_FUNCTION(name)
 #define COMMON_INTERCEPT_FUNCTION_VER(name, ver)                          \