Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759211AbbBICmb (ORCPT ); Sun, 8 Feb 2015 21:42:31 -0500 Received: from mx1.redhat.com ([209.132.183.28]:37554 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755180AbbBICma (ORCPT ); Sun, 8 Feb 2015 21:42:30 -0500 Date: Mon, 9 Feb 2015 10:40:30 +0800 From: Baoquan He To: HATAYAMA Daisuke Cc: ebiederm@xmission.com, vgoyal@redhat.com, masami.hiramatsu.pt@hitachi.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] kernel/panic/kexec: fix "crash_kexec_post_notifiers" option issue in oops path Message-ID: <20150209024030.GA1847@dhcp-16-105.nay.redhat.com> References: <20150205.175943.381586636.d.hatayama@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150205.175943.381586636.d.hatayama@jp.fujitsu.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2658 Lines: 79 On 02/05/15 at 05:59pm, HATAYAMA Daisuke wrote: > The commit f06e5153f4ae2e2f3b0300f0e260e40cb7fefd45 introduced > "crash_kexec_post_notifiers" kernel boot option, which toggles > wheather panic() calls crash_kexec() before or after panic_notifiers > and dump kmsg. > > 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(). > > Signed-off-by: HATAYAMA Daisuke > --- > include/linux/kernel.h | 3 +++ > kernel/kexec.c | 2 ++ > kernel/panic.c | 2 +- > 3 files changed, 6 insertions(+), 1 deletion(-) > > diff --git a/include/linux/kernel.h b/include/linux/kernel.h > index 64ce58b..f47379f 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 9a8a01a..0ecf252 100644 > --- a/kernel/kexec.c > +++ b/kernel/kexec.c > @@ -84,6 +84,8 @@ struct resource crashk_low_res = { > > int kexec_should_crash(struct task_struct *p) > { > + if (crash_kexec_post_notifiers) > + return 0; > if (in_interrupt() || !p->pid || is_global_init(p) || panic_on_oops) > return 1; What if these two conditions !p->pid || is_global_init(p) are satisfied? Seems the behavious is changed. > return 0; > diff --git a/kernel/panic.c b/kernel/panic.c > index 4d8d6f9..6582546 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 > > > > _______________________________________________ > kexec mailing list > kexec@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/kexec -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/