Disable return PAC in __pthread_start.
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.
Bug: 189808795
Change-Id: I953da9078acd1d43eb7a47fb11f75caa0099fa12
diff --git a/libc/bionic/pthread_create.cpp b/libc/bionic/pthread_create.cpp
index 46d9e86..121b26f 100644
--- a/libc/bionic/pthread_create.cpp
+++ b/libc/bionic/pthread_create.cpp
@@ -331,6 +331,11 @@
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);