From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YTwg5-0007KF-1K for kexec@lists.infradead.org; Fri, 06 Mar 2015 18:08:50 +0000 Date: Fri, 6 Mar 2015 13:08:19 -0500 From: Vivek Goyal Subject: Re: [PATCH v2] kernel/panic/kexec: fix "crash_kexec_post_notifiers" option issue in oops path Message-ID: <20150306180819.GB15736@redhat.com> References: <54F9D645.2050008@jp.fujitsu.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <54F9D645.2050008@jp.fujitsu.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: =?utf-8?B?IkhhdGF5YW1hLCBEYWlzdWtlL+eVkeWxsSDlpKfovJQi?= Cc: bhe@redhat.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, 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X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fCmtleGVjIG1haWxpbmcgbGlzdAprZXhl Y0BsaXN0cy5pbmZyYWRlYWQub3JnCmh0dHA6Ly9saXN0cy5pbmZyYWRlYWQub3JnL21haWxtYW4v bGlzdGluZm8va2V4ZWMK From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754516AbbCFSIw (ORCPT ); Fri, 6 Mar 2015 13:08:52 -0500 Received: from mx1.redhat.com ([209.132.183.28]:39151 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752697AbbCFSIu (ORCPT ); Fri, 6 Mar 2015 13:08:50 -0500 Date: Fri, 6 Mar 2015 13:08:19 -0500 From: Vivek Goyal To: =?utf-8?B?IkhhdGF5YW1hLCBEYWlzdWtlL+eVkeWxsSDlpKfovJQi?= Cc: ebiederm@xmission.com, masami.hiramatsu.pt@hitachi.com, hidehiro.kawai.ez@hitachi.com, bhe@redhat.com, linux-kernel@vger.kernel.org, kexec@lists.infradead.org Subject: Re: [PATCH v2] kernel/panic/kexec: fix "crash_kexec_post_notifiers" option issue in oops path Message-ID: <20150306180819.GB15736@redhat.com> References: <54F9D645.2050008@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <54F9D645.2050008@jp.fujitsu.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Mar 07, 2015 at 01:31:01AM +0900, "Hatayama, Daisuke/畑山 大輔" wrote: > The commit f06e5153f4ae2e2f3b0300f0e260e40cb7fefd45 introduced > "crash_kexec_post_notifiers" kernel boot option, which toggles > wheather panic() calls crash_kexec() before panic_notifiers and dump > kmsg or after. > > The problem is that the commit overlooks panic_on_oops kernel boot > option. If it is enabled, crash_kexec() is called directly without > going through panic() in oops path. > > To fix this issue, this patch adds a check to > "crash_kexec_post_notifiers" in the condition of kexec_should_crash(). > > Also, put a comment in kexec_should_crash() to explain not obvious > things on this patch. > > Signed-off-by: HATAYAMA Daisuke > Acked-by: Baoquan He > Tested-by: Hidehiro Kawai > Reviewed-by: Masami Hiramatsu Looks good to me. Acked-by: Vivek Goyal Thanks Vivek > --- > include/linux/kernel.h | 3 +++ > kernel/kexec.c | 11 +++++++++++ > kernel/panic.c | 2 +- > 3 files changed, 15 insertions(+), 1 deletion(-) > > diff --git a/include/linux/kernel.h b/include/linux/kernel.h > index d6d630d..07483c7 100644 > --- a/include/linux/kernel.h > +++ b/include/linux/kernel.h > @@ -426,6 +426,9 @@ extern int panic_on_unrecovered_nmi; > extern int panic_on_io_nmi; > extern int panic_on_warn; > extern int sysctl_panic_on_stackoverflow; > + > +extern bool crash_kexec_post_notifiers; > + > /* > * Only to be used by arch init code. If the user over-wrote the default > * CONFIG_PANIC_TIMEOUT, honor it. > diff --git a/kernel/kexec.c b/kernel/kexec.c > index 38c25b1..5bf6077 100644 > --- a/kernel/kexec.c > +++ b/kernel/kexec.c > @@ -84,6 +84,17 @@ struct resource crashk_low_res = { > > int kexec_should_crash(struct task_struct *p) > { > + /* > + * If crash_kexec_post_notifiers is enabled, don't run > + * crash_kexec() here yet, which must be run after panic > + * notifiers in panic(). > + */ > + if (crash_kexec_post_notifiers) > + return 0; > + /* > + * There are 4 panic() calls in do_exit() path, each of which > + * calls corresponds to each of these 4 conditions. > + */ > if (in_interrupt() || !p->pid || is_global_init(p) || panic_on_oops) > return 1; > return 0; > diff --git a/kernel/panic.c b/kernel/panic.c > index 8136ad7..79ca912 100644 > --- a/kernel/panic.c > +++ b/kernel/panic.c > @@ -32,7 +32,7 @@ static unsigned long tainted_mask; > static int pause_on_oops; > static int pause_on_oops_flag; > static DEFINE_SPINLOCK(pause_on_oops_lock); > -static bool crash_kexec_post_notifiers; > +bool crash_kexec_post_notifiers; > int panic_on_warn __read_mostly; > > int panic_timeout = CONFIG_PANIC_TIMEOUT; > -- > 1.9.3 >