linux-kernel - Re: Lots of bugs with current->state = TASK

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 21 Jan 2010 11:47:41 +0100 (CET)
From:	Julia Lawall <julia@...u.dk>
To:	Steven Rostedt <rostedt@...dmis.org>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	kernel-janitors <kernel-janitors@...r.kernel.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	linux-arch@...r.kernel.org, Greg KH <greg@...ah.com>,
	Andy Whitcroft <apw@...onical.com>
Subject: Re: Lots of bugs with current->state = TASK_*INTERRUPTIBLE

What about something like the following (drivers/macintosh/adb.c):

        add_wait_queue(&state->wait_queue, &wait);
        current->state = TASK_INTERRUPTIBLE;

	for (;;) {
	        req = state->completed;
                if (req != NULL)
                        state->completed = req->next;
                else if (atomic_read(&state->n_pending) == 0)
                        ret = -EIO;
		if (req != NULL || ret != 0)
			break;

                if (file->f_flags & O_NONBLOCK) {
                        ret = -EAGAIN;
                        break;
		}
                if (signal_pending(current)) {
                        ret = -ERESTARTSYS;
                        break;
                }
                spin_unlock_irqrestore(&state->lock, flags);
                schedule();
        	spin_lock_irqsave(&state->lock, flags);
        }

        current->state = TASK_RUNNING;
        remove_wait_queue(&state->wait_queue, &wait);

There is a call to schedule eventually after the first current->state 
assignment, but it is not right after.

thanks,
julia
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/