linux-kernel - Re: 2.6.39-rc2 regression: X201s fails to resume b77dcf8460ae57d4eb9fd3633eb4f97b8fb20716

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 for Android: free password hash cracker in your pocket

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

Date:	Mon, 11 Apr 2011 23:40:33 +0200
From:	Marcel Holtmann <marcel@...tmann.org>
To:	Thomas Gleixner <tglx@...utronix.de>
Cc:	Vinicius Costa Gomes <vinicius.gomes@...nbossa.org>,
	Keith Packard <keithp@...thp.com>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	linux-bluetooth@...r.kernel.org
Subject: Re: 2.6.39-rc2 regression: X201s fails to resume
 b77dcf8460ae57d4eb9fd3633eb4f97b8fb20716

Hi Thomas,

> > > > Can the bluetooth folks please have a look at that ASAP? The obvious
> > > > fast fix for Linus tree is to revert the second hunk for now, but this
> > > > needs to be fixed proper.
> > > 
> > > Who will submit this patch? I'd rather have your name on it so that
> > > people come complain at you...
> > 
> > I took a shot at it and just sent a patch (also attached for convenience) 
> > that should solve the problem.
> 
> Aaarg. No. That patch reverts both hunks.
> 
> --- a/net/bluetooth/hci_core.c
> +++ b/net/bluetooth/hci_core.c
> @@ -586,9 +586,6 @@ static int hci_dev_do_close(struct hci_dev *hdev)
>  	hci_req_cancel(hdev, ENODEV);
>  	hci_req_lock(hdev);
>  
> -	/* Stop timer, it might be running */
> -	del_timer_sync(&hdev->cmd_timer);
> -
>  	if (!test_and_clear_bit(HCI_UP, &hdev->flags)) {
>  		hci_req_unlock(hdev);
>  		return 0;
> 
> As I said before you need that first hunk to stay for the case where
> there is no device up and you return via the !HCI_UP check. You just
> moved back to the state before as the stupid timer is active for
> whatever reason even when HCI_UP is not set.

if I read this right then we have the case that we arm this timer for no
real reason. A device in !HCI_UP should have nothing running. Certainly
not the cmd_timer since it will never process any commands.

According to Gustavo, the problem is really in the hci_reset logic were
we arm the timer even when shutting down the device.

Regards

Marcel


--
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/