linux-kernel - Re: [PATCH] usb_storage: make usb-stor-scan task non-freezable

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]

Message-ID: <Pine.LNX.4.44L0.1107181708590.1663-100000@iolanthe.rowland.org>
Date:	Mon, 18 Jul 2011 17:12:35 -0400 (EDT)
From:	Alan Stern <stern@...land.harvard.edu>
To:	Seth Forshee <seth.forshee@...onical.com>
cc:	Matthew Dharm <mdharm-usb@...-eyed-alien.net>,
	Greg Kroah-Hartman <gregkh@...e.de>,
	<linux-usb@...r.kernel.org>,
	<usb-storage@...ts.one-eyed-alien.net>,
	<linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] usb_storage: make usb-stor-scan task non-freezable

On Mon, 18 Jul 2011, Seth Forshee wrote:

> The following patch is in response to a consistently reproducible
> failure to freeze tasks prior to restoring a hibernation image on a
> Toshiba NB505 netbook. This machine has a built-in USB card reader.
> Since the usb-stor-scan task is freezable but the code in
> quiesce_and_remove_host() that waits for scanning to complete is not,
> khubd can fail to freeze when processing the disconnect for the card
> reader.

What card-reader disconnect?

> It seems that both should either be freezable or not freezable. Since
> there doesn't currently seem to be any freezable way to wait on a
> completion, I started with the simpler approach of making usb-stor-scan
> non-freezable. If it would be preferable to make both freezable I can
> take that approach instead.

I'm not sure what the best approach is.  usb-stor-scan has to be
freezable, because the scanning code registers new child device
structures, which isn't allowed during suspend or hibernation.

Alan Stern

--
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/