am 93a91f0c: Force cts to only run one test at a time.

* commit '93a91f0cf4f015762ac1ed57395c4c0de8ba7db3':
  Force cts to only run one test at a time.

libc/bionic/pthread_internal.h

@@ -130,8 +130,13 @@ __LIBC_HIDDEN__ void pthread_key_clean_all(void);
  */
 #define PTHREAD_STACK_SIZE_DEFAULT ((1 * 1024 * 1024) - SIGSTKSZ)
 
-/* Leave room for a guard page in the internally created signal stacks. */
+// Leave room for a guard page in the internally created signal stacks.
+#if defined(__LP64__)
+// SIGSTKSZ is not big enough for 64-bit arch. See http://b/23041777.
+#define SIGNAL_STACK_SIZE (16 * 1024 + PAGE_SIZE)
+#else
 #define SIGNAL_STACK_SIZE (SIGSTKSZ + PAGE_SIZE)
+#endif
 
 /* Needed by fork. */
 __LIBC_HIDDEN__ extern void __bionic_atfork_run_prepare();

tests/pthread_test.cpp

@@ -27,6 +27,7 @@
 #include <sys/syscall.h>
 #include <time.h>
 #include <unistd.h>
+#include <unwind.h>
 
 #include <atomic>
 #include <regex>
@@ -1244,11 +1245,8 @@ TEST(pthread, pthread_attr_getstack_18908062) {
 }
 
 #if defined(__BIONIC__)
-static pthread_mutex_t gettid_mutex;
 static void* pthread_gettid_np_helper(void* arg) {
-  pthread_mutex_lock(&gettid_mutex);
   *reinterpret_cast<pid_t*>(arg) = gettid();
-  pthread_mutex_unlock(&gettid_mutex);
   return NULL;
 }
 #endif
@@ -1259,15 +1257,11 @@ TEST(pthread, pthread_gettid_np) {
 
   pid_t t_gettid_result;
   pthread_t t;
-  pthread_mutex_init(&gettid_mutex, NULL);
-  pthread_mutex_lock(&gettid_mutex);
   pthread_create(&t, NULL, pthread_gettid_np_helper, &t_gettid_result);
 
   pid_t t_pthread_gettid_np_result = pthread_gettid_np(t);
-  pthread_mutex_unlock(&gettid_mutex);
 
   pthread_join(t, NULL);
-  pthread_mutex_destroy(&gettid_mutex);
 
   ASSERT_EQ(t_gettid_result, t_pthread_gettid_np_result);
 #else
@@ -1578,3 +1572,26 @@ TEST_F(pthread_DeathTest, pthread_mutex_unlock_null_64) {
   GTEST_LOG_(INFO) << "This test tests bionic implementation details on 64 bit devices.";
 #endif
 }
+
+extern _Unwind_Reason_Code FrameCounter(_Unwind_Context* ctx, void* arg);
+
+static volatile bool signal_handler_on_altstack_done;
+
+static void SignalHandlerOnAltStack(int signo, siginfo_t*, void*) {
+  ASSERT_EQ(SIGUSR1, signo);
+  // Check if we have enough stack space for unwinding.
+  int count = 0;
+  _Unwind_Backtrace(FrameCounter, &count);
+  ASSERT_GT(count, 0);
+  // Check if we have enough stack space for logging.
+  std::string s(2048, '*');
+  GTEST_LOG_(INFO) << s;
+  signal_handler_on_altstack_done = true;
+}
+
+TEST(pthread, big_enough_signal_stack_for_64bit_arch) {
+  signal_handler_on_altstack_done = false;
+  ScopedSignalHandler handler(SIGUSR1, SignalHandlerOnAltStack, SA_SIGINFO | SA_ONSTACK);
+  kill(getpid(), SIGUSR1);
+  ASSERT_TRUE(signal_handler_on_altstack_done);
+}

tests/stack_unwinding_test.cpp

@@ -34,7 +34,7 @@
 #define noinline __attribute__((__noinline__))
 #define __unused __attribute__((__unused__))
 
-static _Unwind_Reason_Code FrameCounter(_Unwind_Context* ctx __unused, void* arg) {
+_Unwind_Reason_Code FrameCounter(_Unwind_Context* ctx __unused, void* arg) {
   int* count_ptr = reinterpret_cast<int*>(arg);
 
 #if SHOW_FRAME_LOCATIONS