Messages in this thread | | | Date | Wed, 29 Aug 2012 07:42:55 +0300 | From | Sergey Senozhatsky <> | Subject | Re: [RFC PATCH] x86: use new exception_enter()/exception_exit() API in do_device_not_available() |
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On (08/29/12 00:11), Borislav Petkov wrote: > Date: Wed, 29 Aug 2012 00:11:13 +0200 > From: Borislav Petkov <bp@alien8.de> > To: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> > Cc: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, > "H. Peter Anvin" <hpa@zytor.com>, x86@kernel.org, Steven Rostedt > <rostedt@goodmis.org>, Srikar Dronamraju <srikar@linux.vnet.ibm.com>, > Peter Zijlstra <a.p.zijlstra@chello.nl>, "Paul E. McKenney" > <paulmck@linux.vnet.ibm.com>, linux-kernel@vger.kernel.org > Subject: Re: [RFC PATCH] x86: use new exception_enter()/exception_exit() > API in do_device_not_available() > User-Agent: Mutt/1.5.21 (2010-09-15) > > On Wed, Aug 29, 2012 at 12:00:47AM +0300, Sergey Senozhatsky wrote: > > 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: [<ffffffff814c67cf>] __schedule+0x1c0/0x992 > > [ 676.400304] #1: (rcu_read_lock){.+.+..}, at: [<ffffffff8106a880>] cpuacct_charge+0x27/0x1e0 > > [ 676.400321] > > [ 676.400329] Call Trace: > > [ 676.400340] [<ffffffff8108933a>] lockdep_rcu_suspicious+0x109/0x112 > > [ 676.400347] [<ffffffff8106a8f7>] cpuacct_charge+0x9e/0x1e0 > > [ 676.400353] [<ffffffff8106a880>] ? cpuacct_charge+0x27/0x1e0 > > [ 676.400359] [<ffffffff814c67cf>] ? __schedule+0x1c0/0x992 > > [ 676.400366] [<ffffffff8106d525>] update_curr+0x159/0x200 > > [ 676.400375] [<ffffffff8100a04f>] ? init_fpu+0x4e/0x8f > > [ 676.400382] [<ffffffff8106e0da>] put_prev_task_fair+0x2a/0xac > > [ 676.400388] [<ffffffff814c69a7>] __schedule+0x398/0x992 > > [ 676.400397] [<ffffffff810b4f0a>] ? rcu_irq_exit+0x83/0x99 > > [ 676.400404] [<ffffffff814c8bf0>] ? retint_restore_args+0x13/0x13 > > [ 676.400411] [<ffffffff810889e9>] ? lock_is_held+0x2d/0xa5 > > [ 676.400414] [<ffffffff8100a04f>] ? init_fpu+0x4e/0x8f > > [ 676.400417] [<ffffffff81065d0a>] __cond_resched+0x28/0x34 > > [ 676.400420] [<ffffffff814c701a>] _cond_resched+0x2e/0x35 > > [ 676.400425] [<ffffffff8111cad4>] kmem_cache_alloc+0x4c/0x1c5 > > [ 676.400430] [<ffffffff810021ff>] ? math_state_restore+0x1f/0xdc > > [ 676.400433] [<ffffffff8100a04f>] init_fpu+0x4e/0x8f > > [ 676.400437] [<ffffffff8100220e>] math_state_restore+0x2e/0xdc > > [ 676.400440] [<ffffffff814c982e>] do_device_not_available+0xe/0x10 > > [ 676.400445] [<ffffffff814d161b>] device_not_available+0x1b/0x20 > > > > > > Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> > > > > --- > > > > 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..dff3e72 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_enter(regs); > > Shouldn't that be exception_exit actually? >
OH! NO WAY I did that mistake! That was some last minute in-text-editor changes and somehow I screwed this up. Will re-send in a second.
Sorry, and thank you.
-ss
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