merge in mnc-release history after reset to mnc-dev

Bug: http://b/22047255
Bug: http://b/22091640
Change-Id: I6c51cff43287a6ac4b25fa9ce6a6fc3d232fd047

libc/bionic/pthread_internal.h

@@ -130,13 +130,8 @@ __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

@@ -27,7 +27,6 @@
 #include <sys/syscall.h>
 #include <time.h>
 #include <unistd.h>
-#include <unwind.h>
 
 #include <atomic>
 #include <regex>
@@ -1572,26 +1571,3 @@ 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__))
 
-_Unwind_Reason_Code FrameCounter(_Unwind_Context* ctx __unused, void* arg) {
+static _Unwind_Reason_Code FrameCounter(_Unwind_Context* ctx __unused, void* arg) {
   int* count_ptr = reinterpret_cast<int*>(arg);
 
 #if SHOW_FRAME_LOCATIONS