Merge "Initialize main thread TLS before the global stack guard."

libc/bionic/__libc_init_main_thread.cpp

@@ -69,7 +69,9 @@ void __libc_init_main_thread(KernelArgumentBlock& args) {
 
   // The -fstack-protector implementation uses TLS, so make sure that's
   // set up before we call any function that might get a stack check inserted.
+  // TLS also needs to be set up before errno (and therefore syscalls) can be used.
   __set_tls(main_thread.tls);
+  __init_tls(&main_thread);
 
   // Tell the kernel to clear our tid field when we exit, so we're like any other pthread.
   // As a side-effect, this tells us our pid (which is the same as the main thread's tid).
@@ -91,9 +93,9 @@ void __libc_init_main_thread(KernelArgumentBlock& args) {
   // before we initialize the TLS. Dynamic executables will initialize their copy of the global
   // stack protector from the one in the main thread's TLS.
   __libc_init_global_stack_chk_guard(args);
+  __init_thread_stack_guard(&main_thread);
 
   __init_thread(&main_thread);
-  __init_tls(&main_thread);
 
   // Store a pointer to the kernel argument block in a TLS slot to be
   // picked up by the libc constructor.

libc/bionic/pthread_create.cpp

@@ -56,7 +56,6 @@ void __init_tls(pthread_internal_t* thread) {
   // Slot 0 must point to itself. The x86 Linux kernel reads the TLS from %fs:0.
   thread->tls[TLS_SLOT_SELF] = thread->tls;
   thread->tls[TLS_SLOT_THREAD_ID] = thread;
-  __init_thread_stack_guard(thread);
 }
 
 void __init_thread_stack_guard(pthread_internal_t* thread) {
@@ -182,6 +181,7 @@ static int __allocate_thread(pthread_attr_t* attr, pthread_internal_t** threadp,
   thread->mmap_size = mmap_size;
   thread->attr = *attr;
   __init_tls(thread);
+  __init_thread_stack_guard(thread);
 
   *threadp = thread;
   *child_stack = stack_top;