From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752749Ab2H2EtG (ORCPT ); Wed, 29 Aug 2012 00:49:06 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:65129 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752055Ab2H2EtD (ORCPT ); Wed, 29 Aug 2012 00:49:03 -0400 Date: Wed, 29 Aug 2012 07:47:16 +0300 From: Sergey Senozhatsky To: Borislav Petkov , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Steven Rostedt , Srikar Dronamraju , Peter Zijlstra , "Paul E. McKenney" , linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH] x86: use new exception_enter()/exception_exit() API in do_device_not_available() (v2) Message-ID: <20120829044716.GB3147@swordfish> References: <20120828210047.GA22279@swordfish> <20120828221111.GC9297@liondog.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120828221111.GC9297@liondog.tnic> 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 x86: use new exception_enter()/exception_exit() API in do_device_not_available() RCU can be in extended quiescent state when do_device_not_available() called. [ 676.400274] RCU used illegally from idle CPU! [ 676.400274] rcu_scheduler_active = 1, debug_locks = 0 [ 676.400278] RCU used illegally from extended quiescent state! [ 676.400282] 2 locks held by sed/9468: [ 676.400285] #0: (&rq->lock){-.-.-.}, at: [] __schedule+0x1c0/0x992 [ 676.400304] #1: (rcu_read_lock){.+.+..}, at: [] cpuacct_charge+0x27/0x1e0 [ 676.400321] [ 676.400329] Call Trace: [ 676.400340] [] lockdep_rcu_suspicious+0x109/0x112 [ 676.400347] [] cpuacct_charge+0x9e/0x1e0 [ 676.400353] [] ? cpuacct_charge+0x27/0x1e0 [ 676.400359] [] ? __schedule+0x1c0/0x992 [ 676.400366] [] update_curr+0x159/0x200 [ 676.400375] [] ? init_fpu+0x4e/0x8f [ 676.400382] [] put_prev_task_fair+0x2a/0xac [ 676.400388] [] __schedule+0x398/0x992 [ 676.400397] [] ? rcu_irq_exit+0x83/0x99 [ 676.400404] [] ? retint_restore_args+0x13/0x13 [ 676.400411] [] ? lock_is_held+0x2d/0xa5 [ 676.400414] [] ? init_fpu+0x4e/0x8f [ 676.400417] [] __cond_resched+0x28/0x34 [ 676.400420] [] _cond_resched+0x2e/0x35 [ 676.400425] [] kmem_cache_alloc+0x4c/0x1c5 [ 676.400430] [] ? math_state_restore+0x1f/0xdc [ 676.400433] [] init_fpu+0x4e/0x8f [ 676.400437] [] math_state_restore+0x2e/0xdc [ 676.400440] [] do_device_not_available+0xe/0x10 [ 676.400445] [] device_not_available+0x1b/0x20 Signed-off-by: Sergey Senozhatsky --- arch/x86/kernel/traps.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index ab82cbd..fa226ef 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -654,7 +654,9 @@ do_device_not_available(struct pt_regs *regs, long error_code) return; } #endif + exception_enter(regs); math_state_restore(); /* interrupts still off */ + exception_exit(regs); #ifdef CONFIG_X86_32 conditional_sti(regs); #endif