From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicolai Stange Subject: Re: Linux 4.4-rc4 regression, bisected to "net: fix sock_wake_async() rcu protection" Date: Wed, 30 Dec 2015 12:32:07 +0100 Message-ID: <8760zgnpe0.fsf@gmail.com> References: Mime-Version: 1.0 Content-Type: text/plain Cc: "linux-kernel\@vger.kernel.org" , Network Development , Dmitry Vyukov , Eric Dumazet , "David S. Miller" , Linus Torvalds To: Andy Lutomirski Return-path: In-Reply-To: (Andy Lutomirski's message of "Wed, 30 Dec 2015 03:18:11 -0800") Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Andy Lutomirski writes: > On recent v4.4-rc releases, I can't run emacs. No, really, running > "emacs" in a GNOME 3 session makes gnome-shell think that emacs is > running, but no window is drawn, and the overall system UI is a bit > weird when the invisible emacs window is focused. > > This is 100% reproducible. > > There might be other symptoms involving gdb malfunctioning, but those > are, at best, sporadic. The emacs failure is entirely reliable. I > have no idea what the underlying failure mode is, but failure to wake > a socket waiter seems plausible, I also have no idea why oocalc, > gimp, vim, gedit, firefox, etc aren't affected. > > A somewhat unorthodox "git bisect" run blames: > > commit ceb5d58b217098a657f3850b7a2640f995032e62 > Author: Eric Dumazet > Date: Sun Nov 29 20:03:11 2015 -0800 > > net: fix sock_wake_async() rcu protection > > I've confirmed that v4.4-rc7 with that patch reverted works fine. > > Since the offending commit was apparently a security fix, simply > reverting it might not be the best idea. Please have a look at https://lkml.kernel.org/g/87ege73bma.fsf@gmail.com I ran into the same issue and this one fixes it for me. Best, Nicolai