From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762090AbZCTKOX (ORCPT ); Fri, 20 Mar 2009 06:14:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1762012AbZCTKNq (ORCPT ); Fri, 20 Mar 2009 06:13:46 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:32902 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757926AbZCTKNp (ORCPT ); Fri, 20 Mar 2009 06:13:45 -0400 Subject: lockdep: fix deadlock in lockdep_trace_alloc From: Peter Zijlstra To: Heiko Carstens , Ingo Molnar Cc: Nick Piggin , "lkml," Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: Fri, 20 Mar 2009 11:13:20 +0100 Message-Id: <1237544000.24626.52.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.24.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Heiko reported that we grab the graph lock with irqs enabled. Fix this by providng the same wrapper as all other lockdep entry functions have. Reported-by: Heiko Carstens Signed-off-by: Peter Zijlstra --- diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 3e1cc47..a39cb6d 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -2258,7 +2258,7 @@ void trace_softirqs_off(unsigned long ip) debug_atomic_inc(&redundant_softirqs_off); } -void lockdep_trace_alloc(gfp_t gfp_mask) +static void __lockdep_trace_alloc(gfp_t gfp_mask) { struct task_struct *curr = current; @@ -2283,6 +2283,20 @@ void lockdep_trace_alloc(gfp_t gfp_mask) mark_held_locks(curr, RECLAIM_FS); } +void lockdep_trace_alloc(gfp_t gfp_mask) +{ + unsigned long flags; + + if (unlikely(current->lockdep_recursion)) + return; + + raw_local_irq_save(flags); + current->lockdep_recursion = 1; + __lockdep_trace_alloc(gfp_mask); + current->lockdep_recursion = 0; + raw_local_irq_restore(flags); +} + static int mark_irqflags(struct task_struct *curr, struct held_lock *hlock) { /*