LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>,
	Russell King <linux@armlinux.org.uk>,
	Adrian Salido <salidoa@google.com>,
	Nicolai Stange <nstange@suse.de>,
	Sasha Levin <Alexander.Levin@microsoft.com>,
	Todd Kjos <tkjos@android.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 2/4] ARM: amba: Fix race condition with driver_override
Date: Thu, 26 Apr 2018 10:35:42 +0200	[thread overview]
Message-ID: <20180426083542.GA31073@kroah.com> (raw)
In-Reply-To: <CAMuHMdWLCQoHzuW1UZNP9gdRV3EE6_yPcdyX1NDy65q7Nt4tZw@mail.gmail.com>

On Thu, Apr 26, 2018 at 09:40:08AM +0200, Geert Uytterhoeven wrote:
> Hi Greg,
> 
> On Thu, Apr 26, 2018 at 9:04 AM, Greg Kroah-Hartman
> <gregkh@linuxfoundation.org> wrote:
> > On Wed, Apr 25, 2018 at 07:53:06PM +0200, Geert Uytterhoeven wrote:
> >> On Wed, Apr 25, 2018 at 6:06 PM, Greg Kroah-Hartman
> >> <gregkh@linuxfoundation.org> wrote:
> >> > On Tue, Apr 10, 2018 at 03:21:44PM +0200, Geert Uytterhoeven wrote:
> >> >> The driver_override implementation is susceptible to a race condition
> >> >> when different threads are reading vs storing a different driver
> >> >> override.  Add locking to avoid this race condition.
> >> >>
> >> >> Cfr. commits 6265539776a0810b ("driver core: platform: fix race
> >> >> condition with driver_override") and 9561475db680f714 ("PCI: Fix race
> >> >> condition with driver_override").
> >> >>
> >> >> Fixes: 3cf385713460eb2b ("ARM: 8256/1: driver coamba: add device binding path 'driver_override'")
> >> >> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> >> >> Reviewed-by: Todd Kjos <tkjos@google.com>
> >> >> Cc: stable <stable@vger.kernel.org>
> >>
> >> > As this should go to stable kernels, I've fixed it up to apply without
> >> > patch 1 as that's not a real "fix" that anyone needs...
> >> >
> >> > Please try to remember to put fixes first, and then "trivial" things
> >> > later on in a series.
> >>
> >> I did it on purpose, as the fix is much more ugly without patch 1 applied.
> >> Can't you just take patch 1, too? More consistency is always nice, even for
> >> stable ;-)
> >
> > Consistency is nice, but when you have bug fixes that rely on "trivial"
> > patches, it's usually not nice :(
> >
> > I already committed patch 2 to my tree without 1, so let's leave it
> > as-is for now.
> 
> Unfortunately the version you committed is buggy: the race condition
> also covers the NULL check removed by the trivial patch you skipped,
> so now you can get inconsistent behavior (no output or "(null)") on the
> same running kernel version...
> 
> Please revert and apply both. Thanks!

Ugh, you are right, sorry about that.

I've reverted the offending patch, and added them in the correct order
now, I should have listened to you :)

greg k-h

  reply	other threads:[~2018-04-26  8:35 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-10 13:21 [PATCH v2 0/4] ARM: amba: driver_override improvements and fixes Geert Uytterhoeven
2018-04-10 13:21 ` [PATCH v2 1/4] ARM: amba: Make driver_override output consistent with other buses Geert Uytterhoeven
2018-04-25 15:53   ` Todd Kjos
2018-04-10 13:21 ` [PATCH v2 2/4] ARM: amba: Fix race condition with driver_override Geert Uytterhoeven
2018-04-25 15:56   ` Todd Kjos
2018-04-25 16:06   ` Greg Kroah-Hartman
2018-04-25 17:53     ` Geert Uytterhoeven
2018-04-26  7:04       ` Greg Kroah-Hartman
2018-04-26  7:40         ` Geert Uytterhoeven
2018-04-26  8:35           ` Greg Kroah-Hartman [this message]
2018-04-26  8:45             ` Geert Uytterhoeven
2018-05-09 10:39               ` Russell King - ARM Linux
2018-05-09 13:32                 ` Geert Uytterhoeven
2018-05-09 14:50                   ` Greg Kroah-Hartman
2018-04-10 13:21 ` [PATCH v2 3/4] ARM: amba: Don't read past the end of sysfs "driver_override" buffer Geert Uytterhoeven
2018-04-25 15:56   ` Todd Kjos
2018-04-10 13:21 ` [PATCH v2 4/4] ARM: amba: Fix wrong indentation in driver_override_store() Geert Uytterhoeven
2018-04-25 15:58   ` Todd Kjos
2018-04-10 22:19 ` [PATCH v2 0/4] ARM: amba: driver_override improvements and fixes Russell King - ARM Linux
2018-04-25 16:08   ` Greg Kroah-Hartman
2018-04-25 17:27   ` Geert Uytterhoeven

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180426083542.GA31073@kroah.com \
    --to=gregkh@linuxfoundation.org \
    --cc=Alexander.Levin@microsoft.com \
    --cc=geert+renesas@glider.be \
    --cc=geert@linux-m68k.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux@armlinux.org.uk \
    --cc=nstange@suse.de \
    --cc=salidoa@google.com \
    --cc=tkjos@android.com \
    --subject='Re: [PATCH v2 2/4] ARM: amba: Fix race condition with driver_override' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).