Commit b16b3855 authored by Jens Axboe's avatar Jens Axboe
Browse files

kernel: stop masking signals in create_io_thread() 



This is racy - move the blocking into when the task is created and
we're marking it as PF_IO_WORKER anyway. The IO threads are now
prepared to handle signals like SIGSTOP as well, so clear that from
the mask to allow proper stopping of IO threads.

Acked-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
Reported-by: default avatarOleg Nesterov <oleg@redhat.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent dbe1bdbb

kernel/fork.c

+8 −8
Original line number Diff line number Diff line
@@ -1940,8 +1940,14 @@ static __latent_entropy struct task_struct *copy_process( 
	p = dup_task_struct(current, node);

	if (!p)

		goto fork_out;

	if (args->io_thread)

	if (args->io_thread) {

		/*

		 * Mark us an IO worker, and block any signal that isn't

		 * fatal or STOP

		 */

		p->flags |= PF_IO_WORKER;

		siginitsetinv(&p->blocked, sigmask(SIGKILL)|sigmask(SIGSTOP));

	}



	/*

	 * This _must_ happen before we call free_task(), i.e. before we jump
@@ -2430,14 +2436,8 @@ struct task_struct *create_io_thread(int (*fn)(void *), void *arg, int node) 
		.stack_size	= (unsigned long)arg,

		.io_thread	= 1,

	};

	struct task_struct *tsk;



	tsk = copy_process(NULL, 0, node, &args);

	if (!IS_ERR(tsk)) {

		sigfillset(&tsk->blocked);

		sigdelsetmask(&tsk->blocked, sigmask(SIGKILL));

	}

	return tsk;

	return copy_process(NULL, 0, node, &args);

}



/*