From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Subject: Re: [PATCH 2/4] swait: add the missing killable swaits Date: Thu, 29 Jun 2017 14:54:02 +0200 Message-ID: <20170629125402.GH26046@kroah.com> References: <20170614222017.14653-1-mcgrof@kernel.org> <20170614222017.14653-3-mcgrof@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20170614222017.14653-3-mcgrof-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Luis R. Rodriguez" Cc: mfuzzey-mB3Nsq4MPf1BDgjK7y7TUQ@public.gmane.org, ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org, dmitry.torokhov-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, wagi-kQCPcA+X3s7YtjvyW6yDsg@public.gmane.org, dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, jewalt-d4N2ExZK1jaSe5ORCPIMD9BPR1lH4CV8@public.gmane.org, rafal-g1n6cQUeyibVItvQsEIGlw@public.gmane.org, arend.vanspriel-dY08KVG/lbpWk0Htik3J/w@public.gmane.org, rjw-LthD3rsA81gm4RdzfppkhA@public.gmane.org, yi1.li-VuQAYsv1563Yd54FQh9/CA@public.gmane.org, atull-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, moritz.fischer-+aYTwkv1SeIAvxtiuMwx3w@public.gmane.org, pmladek-IBi9RG/b67k@public.gmane.org, johannes.berg-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, emmanuel.grumbach-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, luciano.coelho-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, kvalo-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, luto-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, keescook-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org, takahiro.akashi-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, dhowells-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, pjones-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, hdegoede-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, alan-VuQAYsv1563Yd54FQh9/CA@public.gmane.org, tytso-3s7WtUTddSA@public.gmane.org, mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, paul.gortmaker-CWA4WttNNZF54TAoqtyWWQ@public.gmane.org, mtosatti-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, mawilcox-0li6OtcxBFHby3iVrkZq2A@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.orgs List-Id: linux-api@vger.kernel.org On Wed, Jun 14, 2017 at 03:20:15PM -0700, Luis R. Rodriguez wrote: > Code in kernel which incorrectly used the non-killable variants could > end up having waits killed improperly. The respective killable waits > have been upstream for a while: > > o wait_for_completion_killable() > o wait_for_completion_killable_timeout() > > swait has been upstream since v4.6. Older kernels have had the > above variants in place for a long time. > > Cc: stable # 4.6 > Signed-off-by: Luis R. Rodriguez > --- > include/linux/swait.h | 25 +++++++++++++++++++++++++ > 1 file changed, 25 insertions(+) > > diff --git a/include/linux/swait.h b/include/linux/swait.h > index c1f9c62a8a50..2c700694d50a 100644 > --- a/include/linux/swait.h > +++ b/include/linux/swait.h > @@ -169,4 +169,29 @@ do { \ > __ret; \ > }) > > +#define __swait_event_killable(wq, condition) \ > + ___swait_event(wq, condition, TASK_KILLABLE, 0, schedule()) > + > +#define swait_event_killable(wq, condition) \ > +({ \ > + int __ret = 0; \ > + if (!(condition)) \ > + __ret = __swait_event_killable(wq, condition); \ > + __ret; \ > +}) > + > +#define __swait_event_killable_timeout(wq, condition, timeout) \ > + ___swait_event(wq, ___wait_cond_timeout(condition), \ > + TASK_KILLABLE, timeout, \ > + __ret = schedule_timeout(__ret)) > + > +#define swait_event_killable_timeout(wq, condition, timeout) \ > +({ \ > + long __ret = timeout; \ > + if (!___wait_cond_timeout(condition)) \ > + __ret = __swait_event_killable_timeout(wq, \ > + condition, timeout); \ > + __ret; \ > +}) > + > #endif /* _LINUX_SWAIT_H */ Do you really still want to add these, now that we know we shouldn't be using swait in "real" code? :) thanks, greg k-h From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:41362 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752796AbdF2MyE (ORCPT ); Thu, 29 Jun 2017 08:54:04 -0400 Date: Thu, 29 Jun 2017 14:54:02 +0200 From: Greg KH To: "Luis R. Rodriguez" Cc: mfuzzey@parkeon.com, ebiederm@xmission.com, dmitry.torokhov@gmail.com, wagi@monom.org, dwmw2@infradead.org, jewalt@lgsinnovations.com, rafal@milecki.pl, arend.vanspriel@broadcom.com, rjw@rjwysocki.net, yi1.li@linux.intel.com, atull@kernel.org, moritz.fischer@ettus.com, pmladek@suse.com, johannes.berg@intel.com, emmanuel.grumbach@intel.com, luciano.coelho@intel.com, kvalo@codeaurora.org, luto@kernel.org, torvalds@linux-foundation.org, keescook@chromium.org, takahiro.akashi@linaro.org, dhowells@redhat.com, pjones@redhat.com, hdegoede@redhat.com, alan@linux.intel.com, tytso@mit.edu, mtk.manpages@gmail.com, paul.gortmaker@windriver.com, mtosatti@redhat.com, mawilcox@microsoft.com, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, "stable # 4 . 6" Subject: Re: [PATCH 2/4] swait: add the missing killable swaits Message-ID: <20170629125402.GH26046@kroah.com> References: <20170614222017.14653-1-mcgrof@kernel.org> <20170614222017.14653-3-mcgrof@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170614222017.14653-3-mcgrof@kernel.org> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Wed, Jun 14, 2017 at 03:20:15PM -0700, Luis R. Rodriguez wrote: > Code in kernel which incorrectly used the non-killable variants could > end up having waits killed improperly. The respective killable waits > have been upstream for a while: > > o wait_for_completion_killable() > o wait_for_completion_killable_timeout() > > swait has been upstream since v4.6. Older kernels have had the > above variants in place for a long time. > > Cc: stable # 4.6 > Signed-off-by: Luis R. Rodriguez > --- > include/linux/swait.h | 25 +++++++++++++++++++++++++ > 1 file changed, 25 insertions(+) > > diff --git a/include/linux/swait.h b/include/linux/swait.h > index c1f9c62a8a50..2c700694d50a 100644 > --- a/include/linux/swait.h > +++ b/include/linux/swait.h > @@ -169,4 +169,29 @@ do { \ > __ret; \ > }) > > +#define __swait_event_killable(wq, condition) \ > + ___swait_event(wq, condition, TASK_KILLABLE, 0, schedule()) > + > +#define swait_event_killable(wq, condition) \ > +({ \ > + int __ret = 0; \ > + if (!(condition)) \ > + __ret = __swait_event_killable(wq, condition); \ > + __ret; \ > +}) > + > +#define __swait_event_killable_timeout(wq, condition, timeout) \ > + ___swait_event(wq, ___wait_cond_timeout(condition), \ > + TASK_KILLABLE, timeout, \ > + __ret = schedule_timeout(__ret)) > + > +#define swait_event_killable_timeout(wq, condition, timeout) \ > +({ \ > + long __ret = timeout; \ > + if (!___wait_cond_timeout(condition)) \ > + __ret = __swait_event_killable_timeout(wq, \ > + condition, timeout); \ > + __ret; \ > +}) > + > #endif /* _LINUX_SWAIT_H */ Do you really still want to add these, now that we know we shouldn't be using swait in "real" code? :) thanks, greg k-h