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:   Tue, 6 Jun 2017 19:54:13 +0200
From:   "Luis R. Rodriguez" <mcgrof@...nel.org>
To:     linux-fsdevel@...r.kernel.org
Cc:     Alan Cox <alan@...ux.intel.com>, fsdevel@...r.kernel.org,
        "Luis R. Rodriguez" <mcgrof@...nel.org>,
        Stephen Boyd <stephen.boyd@...aro.org>,
        "Li, Yi" <yi1.li@...ux.intel.com>,
        Dmitry Torokhov <dmitry.torokhov@...il.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Jonathan Corbet <corbet@....net>,
        "Eric W. Biederman" <ebiederm@...ssion.com>,
        "Michael Kerrisk (man-pages)" <mtk.manpages@...il.com>,
        Andy Lutomirski <luto@...nel.org>,
        Greg KH <gregkh@...uxfoundation.org>,
        "Fuzzey, Martin" <mfuzzey@...keon.com>,
        Linux API <linux-api@...r.kernel.org>,
        Daniel Wagner <wagi@...om.org>,
        David Woodhouse <dwmw2@...radead.org>,
        jewalt@...innovations.com, rafal@...ecki.pl,
        Arend Van Spriel <arend.vanspriel@...adcom.com>,
        "Rafael J. Wysocki" <rjw@...ysocki.net>,
        atull@...nsource.altera.com,
        Moritz Fischer <moritz.fischer@...us.com>,
        Petr Mladek <pmladek@...e.com>,
        Johannes Berg <johannes.berg@...el.com>,
        Emmanuel Grumbach <emmanuel.grumbach@...el.com>,
        Luca Coelho <luciano.coelho@...el.com>,
        Kalle Valo <kvalo@...eaurora.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Kees Cook <keescook@...omium.org>,
        AKASHI Takahiro <takahiro.akashi@...aro.org>,
        David Howells <dhowells@...hat.com>,
        Peter Jones <pjones@...hat.com>,
        Hans de G oede <hdegoede@...hat.com>,
        Ted Ts'o <tytso@....edu>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2] firmware: fix sending -ERESTARTSYS due to signal on
 fallback

Using the right linux-fsdevel this time also, this was the second reply.

  Luis

On Tue, Jun 06, 2017 at 06:47:34PM +0200, Luis R. Rodriguez wrote:
> Adding fsdevel folks.
> 
> On Tue, Jun 06, 2017 at 03:53:16PM +0100, Alan Cox wrote:
> > > "Unix tradition (and thus almost all applications) believe file store
> > > writes to
> > > be non signal interruptible. It would not be safe or practical to
> > > change that
> > > guarantee."
> > 
> > Yep everyone codes
> > 
> > 	write(disk_file, "foo", 3);
> > 
> > not while(..) blah around it.
> 
> Thanks for the confirmation! That's a simple enough explanation.
> 
> > > For these two reasons then it would seem best we do two things
> > > actually:
> > > 
> > > 1) return -EINTR instead of -EAGAIN when we detect
> > > swait_event_interruptible_timeout()
> > > got interrupted by a signal (it returns -ERESTARTSYS)
> > > 2) Do as you note below and add wait_event_killable_timeout()
> > 
> > Pedantic detail that I don't think affects you
> > 
> > If you have completed a part of the I/O then you should return the byte
> > processed count not EINTR, but -1,EINTR if no progress was made.
> 
> You are right with some new exceptions and with regards to the future:
> 
> The syfs loading interface for firmware currently goes through the
> data file exposed on syfs, the respective write op firmware_data_write()
> only checks for signals at the beginning. After that its a full one
> swoop try to write if you are following the old tradition and are using
> a buffer allocated by the firmware API.
> 
> If you are using the relatively new request_firmware_into_buf() added
> by Stephen Boyd which lets the driver provide the allocated buffer then
> we have a loop in firmware_rw() which should be fixed to:
> 
> 1) Check for signals
> 2) Do what you noted above.
> 
> Furthermore Yi Li over at Intel is adding some new API calls which would
> re-use some of this for FPGA firmwares which are also very large, that
> work should consider the above and fix appropriately as well.
> 
>   Luis
> 

-- 
Luis Rodriguez, SUSE LINUX GmbH
Maxfeldstrasse 5; D-90409 Nuernberg

Powered by blists - more mailing lists