From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754426AbbANTVP (ORCPT ); Wed, 14 Jan 2015 14:21:15 -0500 Received: from terminus.zytor.com ([198.137.202.10]:39892 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754384AbbANTVM (ORCPT ); Wed, 14 Jan 2015 14:21:12 -0500 Date: Wed, 14 Jan 2015 11:20:32 -0800 From: tip-bot for Heiko Carstens Message-ID: Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, hpa@zytor.com, tglx@linutronix.de, paulmck@linux.vnet.ibm.com, mingo@kernel.org, heiko.carstens@de.ibm.com Reply-To: tglx@linutronix.de, hpa@zytor.com, akpm@linux-foundation.org, torvalds@linux-foundation.org, peterz@infradead.org, linux-kernel@vger.kernel.org, heiko.carstens@de.ibm.com, mingo@kernel.org, paulmck@linux.vnet.ibm.com In-Reply-To: <20150107090441.GC4365@osiris> References: <20150107090441.GC4365@osiris> To: linux-tip-commits@vger.kernel.org Subject: [tip:locking/core] softirq/preempt: Add missing current-> preempt_disable_ip update Git-Commit-ID: 0f1ba9a2cea52896448ef4e14a4cb1880b8e5bee X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 0f1ba9a2cea52896448ef4e14a4cb1880b8e5bee Gitweb: http://git.kernel.org/tip/0f1ba9a2cea52896448ef4e14a4cb1880b8e5bee Author: Heiko Carstens AuthorDate: Wed, 7 Jan 2015 10:04:41 +0100 Committer: Ingo Molnar CommitDate: Wed, 14 Jan 2015 15:16:21 +0100 softirq/preempt: Add missing current->preempt_disable_ip update While debugging some "sleeping function called from invalid context" bug I realized that the debugging message "Preemption disabled at:" pointed to an incorrect function. In particular if the last function/action that disabled preemption was spin_lock_bh() then current->preempt_disable_ip won't be updated. The reason for this is that __local_bh_disable_ip() will increase preempt_count manually instead of calling preempt_count_add(), which would handle the update correctly. It look like the manual handling was done to work around some lockdep issue. So add the missing update of current->preempt_disable_ip to __local_bh_disable_ip() as well. Signed-off-by: Heiko Carstens Signed-off-by: Peter Zijlstra (Intel) Cc: Paul E. McKenney Cc: Andrew Morton Cc: Linus Torvalds Link: http://lkml.kernel.org/r/20150107090441.GC4365@osiris Signed-off-by: Ingo Molnar --- kernel/softirq.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/kernel/softirq.c b/kernel/softirq.c index 501baa9..b9ae816 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -114,8 +114,12 @@ void __local_bh_disable_ip(unsigned long ip, unsigned int cnt) trace_softirqs_off(ip); raw_local_irq_restore(flags); - if (preempt_count() == cnt) + if (preempt_count() == cnt) { +#ifdef CONFIG_DEBUG_PREEMPT + current->preempt_disable_ip = get_parent_ip(CALLER_ADDR1); +#endif trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); + } } EXPORT_SYMBOL(__local_bh_disable_ip); #endif /* CONFIG_TRACE_IRQFLAGS */