Commit 06a101ca authored by Jens Axboe's avatar Jens Axboe
Browse files

exit: move core of do_wait() into helper 



Rather than have a maze of gotos, put the actual logic in __do_wait()
and have do_wait() loop deal with waitqueue setup/teardown and whether
to call __do_wait() again.

No functional changes intended in this patch.

Acked-by: default avatarChristian Brauner <brauner@kernel.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 9d900d4e

kernel/exit.c

+31 −20
Original line number Diff line number Diff line
@@ -1590,16 +1590,10 @@ static int do_wait_pid(struct wait_opts *wo) 
	return 0;

}



static long do_wait(struct wait_opts *wo)

static long __do_wait(struct wait_opts *wo)

{

	int retval;

	long retval;



	trace_sched_process_wait(wo->wo_pid);



	init_waitqueue_func_entry(&wo->child_wait, child_wait_callback);

	wo->child_wait.private = current;

	add_wait_queue(&current->signal->wait_chldexit, &wo->child_wait);

repeat:

	/*

	 * If there is nothing that can match our criteria, just get out.

	 * We will clear ->notask_error to zero if we see any child that
@@ -1611,24 +1605,23 @@ static long do_wait(struct wait_opts *wo) 
	   (!wo->wo_pid || !pid_has_task(wo->wo_pid, wo->wo_type)))

		goto notask;



	set_current_state(TASK_INTERRUPTIBLE);

	read_lock(&tasklist_lock);



	if (wo->wo_type == PIDTYPE_PID) {

		retval = do_wait_pid(wo);

		if (retval)

			goto end;

			return retval;

	} else {

		struct task_struct *tsk = current;



		do {

			retval = do_wait_thread(wo, tsk);

			if (retval)

				goto end;

				return retval;



			retval = ptrace_do_wait(wo, tsk);

			if (retval)

				goto end;

				return retval;



			if (wo->wo_flags & __WNOTHREAD)

				break;
@@ -1638,14 +1631,32 @@ static long do_wait(struct wait_opts *wo) 


notask:

	retval = wo->notask_error;

	if (!retval && !(wo->wo_flags & WNOHANG)) {

		retval = -ERESTARTSYS;

		if (!signal_pending(current)) {

			schedule();

			goto repeat;

		}

	if (!retval && !(wo->wo_flags & WNOHANG))

		return -ERESTARTSYS;



	return retval;

}

end:



static long do_wait(struct wait_opts *wo)

{

	int retval;



	trace_sched_process_wait(wo->wo_pid);



	init_waitqueue_func_entry(&wo->child_wait, child_wait_callback);

	wo->child_wait.private = current;

	add_wait_queue(&current->signal->wait_chldexit, &wo->child_wait);



	do {

		set_current_state(TASK_INTERRUPTIBLE);

		retval = __do_wait(wo);

		if (retval != -ERESTARTSYS)

			break;

		if (signal_pending(current))

			break;

		schedule();

	} while (1);



	__set_current_state(TASK_RUNNING);

	remove_wait_queue(&current->signal->wait_chldexit, &wo->child_wait);

	return retval;