Snap for 7445263 from 07a37c4ba75e5c0317422583254e743d3404ec4c to sc-d2-release

Change-Id: I21ae4191ce7afbc167eb1b15cccc6d6241f35fad

3 files changed, 33 insertions, 10 deletions

diff --git a/libc/bionic/pthread_create.cpp b/libc/bionic/pthread_create.cpp
index 46d9e8672..121b26f82 100644
--- a/libc/bionic/pthread_create.cpp
+++ b/libc/bionic/pthread_create.cpp
@@ -331,6 +331,11 @@ void __set_stack_and_tls_vma_name(bool is_main_thread) {
 extern "C" int __rt_sigprocmask(int, const sigset64_t*, sigset64_t*, size_t);
 
 __attribute__((no_sanitize("hwaddress")))
+#ifdef __aarch64__
+// This function doesn't return, but it does appear in stack traces. Avoid using return PAC in this
+// function because we may end up resetting IA, which may confuse unwinders due to mismatching keys.
+__attribute__((target("branch-protection=bti")))
+#endif
 static int __pthread_start(void* arg) {
   pthread_internal_t* thread = reinterpret_cast<pthread_internal_t*>(arg);
 
diff --git a/tests/dl_test.cpp b/tests/dl_test.cpp
index 766f27a0b..47bf13374 100644
--- a/tests/dl_test.cpp
+++ b/tests/dl_test.cpp
@@ -264,8 +264,11 @@ static void create_ld_config_file(const char* config_file) {
 #endif
 
 #if defined(__BIONIC__)
-static bool is_debuggable_build() {
-  return android::base::GetBoolProperty("ro.debuggable", false);
+// This test can't rely on ro.debuggable, because it might have been forced on
+// in a user build ("Force Debuggable"). In that configuration, ro.debuggable is
+// true, but Bionic's LD_CONFIG_FILE testing support is still disabled.
+static bool is_user_build() {
+  return android::base::GetProperty("ro.build.type", "user") == std::string("user");
 }
 #endif
 
@@ -282,7 +285,7 @@ static bool is_debuggable_build() {
 TEST(dl, exec_with_ld_config_file) {
 #if defined(__BIONIC__)
   SKIP_WITH_HWASAN << "libclang_rt.hwasan is not found with custom ld config";
-  if (!is_debuggable_build()) {
+  if (is_user_build()) {
     GTEST_SKIP() << "LD_CONFIG_FILE is not supported on user build";
   }
   std::string helper = GetTestlibRoot() +
@@ -319,7 +322,7 @@ TEST(dl, exec_with_ld_config_file) {
 TEST(dl, exec_with_ld_config_file_with_ld_preload) {
 #if defined(__BIONIC__)
   SKIP_WITH_HWASAN << "libclang_rt.hwasan is not found with custom ld config";
-  if (!is_debuggable_build()) {
+  if (is_user_build()) {
     GTEST_SKIP() << "LD_CONFIG_FILE is not supported on user build";
   }
   std::string helper = GetTestlibRoot() +
@@ -356,8 +359,8 @@ TEST(dl, disable_ld_config_file) {
     // This test is only for CTS.
     GTEST_SKIP() << "test is not supported with root uid";
   }
-  if (is_debuggable_build()) {
-    GTEST_SKIP() << "test is not supported on debuggable build";
+  if (!is_user_build()) {
+    GTEST_SKIP() << "test requires user build";
   }
 
   std::string error_message = std::string("CANNOT LINK EXECUTABLE ") +
diff --git a/tests/stack_unwinding_test.cpp b/tests/stack_unwinding_test.cpp
index 0ff6f30a6..2f891a6e1 100644
--- a/tests/stack_unwinding_test.cpp
+++ b/tests/stack_unwinding_test.cpp
@@ -66,13 +66,28 @@ static int noinline unwind_one_frame_deeper() {
   return count;
 }
 
-TEST(stack_unwinding, easy) {
+static void UnwindTest() {
   int count = 0;
   _Unwind_Backtrace(FrameCounter, &count);
   int deeper_count = unwind_one_frame_deeper();
   ASSERT_EQ(count + 1, deeper_count);
 }
 
+TEST(stack_unwinding, easy) {
+  UnwindTest();
+}
+
+TEST(stack_unwinding, thread) {
+  pthread_t thread;
+  ASSERT_EQ(0, pthread_create(&thread, nullptr, [](void*) -> void* {
+    UnwindTest();
+    return nullptr;
+  }, nullptr));
+  void *retval;
+  ASSERT_EQ(0, pthread_join(thread, &retval));
+  EXPECT_EQ(nullptr, retval);
+}
+
 struct UnwindData {
   volatile bool signal_handler_complete = false;
   int expected_frame_count = 0;
@@ -98,7 +113,7 @@ static void verify_unwind_data(const UnwindData& unwind_data) {
   EXPECT_EQ(unwind_data.handler_frame_count + 1, unwind_data.handler_one_deeper_frame_count);
 }
 
-static void noinline UnwindTest() {
+static void noinline SignalUnwindTest() {
   g_unwind_data = {};
 
   _Unwind_Backtrace(FrameCounter, &g_unwind_data.expected_frame_count);
@@ -114,12 +129,12 @@ static void noinline UnwindTest() {
 TEST(stack_unwinding, unwind_through_signal_frame) {
   ScopedSignalHandler ssh(SIGUSR1, UnwindSignalHandler);
 
-  UnwindTest();
+  SignalUnwindTest();
 }
 
 // On LP32, the SA_SIGINFO flag gets you __restore_rt instead of __restore.
 TEST(stack_unwinding, unwind_through_signal_frame_SA_SIGINFO) {
   ScopedSignalHandler ssh(SIGUSR1, UnwindSignalHandler, SA_SIGINFO);
 
-  UnwindTest();
+  SignalUnwindTest();
 }