simplify errno implementation

the motivation for the errno_ptr field in the thread structure, which
this commit removes, was to allow the main thread's errno to keep its
address when lazy thread pointer initialization was used. &errno was
evaluated prior to setting up the thread pointer and stored in
errno_ptr for the main thread; subsequently created threads would have
errno_ptr pointing to their own errno_val in the thread structure.

since lazy initialization was removed, there is no need for this extra
level of indirection; __errno_location can simply return the address
of the thread's errno_val directly. this does cause &errno to change,
but the change happens before entry to application code, and thus is
not observable.

1 files changed, 0 insertions, 1 deletions

diff --git a/src/env/__init_tls.c b/src/env/__init_tls.c
index e1a2b614..f7eab8d6 100644
--- a/src/env/__init_tls.c
+++ b/src/env/__init_tls.c
@@ -16,7 +16,6 @@ int __init_tp(void *p)
 	if (!r) libc.can_do_threads = 1;
 	libc.has_thread_pointer = 1;
 	td->tid = td->pid = __syscall(SYS_set_tid_address, &td->tid);
-	td->errno_ptr = &td->errno_val;
 	return 0;
 }