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* [PATCH] arm64: annotate irq off before schedule
@ 2015-12-09  7:23 Ming Lei
  2015-12-09 10:55 ` Catalin Marinas
  0 siblings, 1 reply; 4+ messages in thread
From: Ming Lei @ 2015-12-09  7:23 UTC (permalink / raw)
  To: linux-arm-kernel

Before schedule in ret_to_user(), irq has been disabled,
so irq off should be annotated for killing the following
lockdep warning during kernel booting:

[   13.762775] DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled)
[   13.768065] ------------[ cut here ]------------
[   13.772843] WARNING: at kernel/locking/lockdep.c:3519
[   13.777866] Modules linked in:
[   13.782398] CPU: 1 PID: 1 Comm: init Not tainted 4.4.0-rc4+ #54
[   13.788287] Hardware name: AppliedMicro Mustang/Mustang, BIOS 2.0.0 Oct 23 2015
[   13.795557] task: fffffe07c0440000 ti: fffffe07c0480000 task.ti: fffffe07c0480000
[   13.803005] PC is at check_flags.part.35+0x144/0x19c
[   13.807943] LR is at check_flags.part.35+0x144/0x19c
[   13.812882] pc : [<fffffe000011479c>] lr : [<fffffe000011479c>] pstate: 800001c5
[   13.820238] sp : fffffe07c0483d90
[   13.823534] x29: fffffe07c0483d90 x28: fffffe07c0480000
[   13.828839] x27: fffffe0000cc2000 x26: fffffe0000861bd0
[   13.834144] x25: 0000000000000001 x24: 000003ffe3504d50
[   13.839450] x23: 0000000000000000 x22: fffffe0000db5000
[   13.844755] x21: fffffe0000aba788 x20: fffffe0000ceaa98
[   13.850059] x19: fffffe0001b7e000 x18: 0000000000000000
[   13.855364] x17: 000003ffb2ba4440 x16: 000003ffb2bbd000
[   13.860670] x15: 000003ffb27241a0 x14: 0ffffffffffffffd
[   13.865975] x13: 0000000000000008 x12: 0101010101010101
[   13.871280] x11: 7f7f7f7f7f7f7f7f x10: fefefefefefeff63
[   13.876585] x9 : 000000000000013d x8 : fffffe07c0483ae0
[   13.881889] x7 : fffffe07c0440000 x6 : fffffe0000122008
[   13.887196] x5 : 0000000000000000 x4 : fffffe0000cc2000
[   13.892501] x3 : fffffe07c0483c10 x2 : 0000000000000002
[   13.897807] x1 : 0000000000000000 x0 : 000000000000002e
[   13.904593] ---[ end trace 42e2299dc2cf1b7d ]---
[   13.909184] Call trace:
[   13.911618] [<fffffe000011479c>] check_flags.part.35+0x144/0x19c
[   13.917594] [<fffffe00001151a4>] lock_is_held+0x7c/0x88
[   13.922793] [<fffffe000012c514>] rcu_read_lock_sched_held+0xa0/0xac
[   13.929028] [<fffffe0000132fe4>] rcu_note_context_switch+0x28c/0x56c
[   13.935350] [<fffffe0000861020>] __schedule+0x4c/0xa28
[   13.940462] [<fffffe0000861bd0>] schedule+0x40/0xa0
[   13.945315] [<fffffe0000093bb0>] ret_to_user+0x0/0x24
[   13.950339] possible reason: unannotated irqs-off.
[   13.955104] irq event stamp: 2488963
[   13.958660] hardirqs last  enabled at (2488963): [<fffffe0000093a98>] el0_irq_naked+0x1c/0x24
[   13.967151] hardirqs last disabled at (2488962): [<fffffe0000093a84>] el0_irq_naked+0x8/0x24
[   13.975557] softirqs last  enabled at (2488958): [<fffffe00000cb1f4>] __do_softirq+0x308/0x4f8
[   13.984137] softirqs last disabled at (2488935): [<fffffe00000cb6f0>] irq_exit+0x9c/0xec

Signed-off-by: Ming Lei <ming.lei@canonical.com>
---
 arch/arm64/kernel/entry.S | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 7ed3d75..4769190 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -634,6 +634,9 @@ work_pending:
 	bl	do_notify_resume
 	b	ret_to_user
 work_resched:
+#ifdef CONFIG_TRACE_IRQFLAGS
+	bl	trace_hardirqs_off
+#endif
 	bl	schedule
 
 /*
-- 
1.9.1

^ permalink raw reply related	[flat|nested] 4+ messages in thread

* [PATCH] arm64: annotate irq off before schedule
  2015-12-09  7:23 [PATCH] arm64: annotate irq off before schedule Ming Lei
@ 2015-12-09 10:55 ` Catalin Marinas
  2015-12-10  6:04   ` Ming Lei
  0 siblings, 1 reply; 4+ messages in thread
From: Catalin Marinas @ 2015-12-09 10:55 UTC (permalink / raw)
  To: linux-arm-kernel

On Wed, Dec 09, 2015 at 03:23:49PM +0800, Ming Lei wrote:
> diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
> index 7ed3d75..4769190 100644
> --- a/arch/arm64/kernel/entry.S
> +++ b/arch/arm64/kernel/entry.S
> @@ -634,6 +634,9 @@ work_pending:
>  	bl	do_notify_resume
>  	b	ret_to_user
>  work_resched:
> +#ifdef CONFIG_TRACE_IRQFLAGS
> +	bl	trace_hardirqs_off
> +#endif
>  	bl	schedule

I think Will already queued a similar patch, though he hasn't pushed it
out yet.

-- 
Catalin

^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH] arm64: annotate irq off before schedule
  2015-12-09 10:55 ` Catalin Marinas
@ 2015-12-10  6:04   ` Ming Lei
  2015-12-10 10:31     ` Will Deacon
  0 siblings, 1 reply; 4+ messages in thread
From: Ming Lei @ 2015-12-10  6:04 UTC (permalink / raw)
  To: linux-arm-kernel

On Wed, Dec 9, 2015 at 6:55 PM, Catalin Marinas <catalin.marinas@arm.com> wrote:
> On Wed, Dec 09, 2015 at 03:23:49PM +0800, Ming Lei wrote:
>> diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
>> index 7ed3d75..4769190 100644
>> --- a/arch/arm64/kernel/entry.S
>> +++ b/arch/arm64/kernel/entry.S
>> @@ -634,6 +634,9 @@ work_pending:
>>       bl      do_notify_resume
>>       b       ret_to_user
>>  work_resched:
>> +#ifdef CONFIG_TRACE_IRQFLAGS
>> +     bl      trace_hardirqs_off
>> +#endif
>>       bl      schedule
>
> I think Will already queued a similar patch, though he hasn't pushed it
> out yet.

I tested the misc-patches branch of Will's tree on kerne.org, and looks
the locpdep warning still can be observed.

Thanks,

>
> --
> Catalin
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH] arm64: annotate irq off before schedule
  2015-12-10  6:04   ` Ming Lei
@ 2015-12-10 10:31     ` Will Deacon
  0 siblings, 0 replies; 4+ messages in thread
From: Will Deacon @ 2015-12-10 10:31 UTC (permalink / raw)
  To: linux-arm-kernel

On Thu, Dec 10, 2015 at 02:04:41PM +0800, Ming Lei wrote:
> On Wed, Dec 9, 2015 at 6:55 PM, Catalin Marinas <catalin.marinas@arm.com> wrote:
> > On Wed, Dec 09, 2015 at 03:23:49PM +0800, Ming Lei wrote:
> >> diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
> >> index 7ed3d75..4769190 100644
> >> --- a/arch/arm64/kernel/entry.S
> >> +++ b/arch/arm64/kernel/entry.S
> >> @@ -634,6 +634,9 @@ work_pending:
> >>       bl      do_notify_resume
> >>       b       ret_to_user
> >>  work_resched:
> >> +#ifdef CONFIG_TRACE_IRQFLAGS
> >> +     bl      trace_hardirqs_off
> >> +#endif
> >>       bl      schedule
> >
> > I think Will already queued a similar patch, though he hasn't pushed it
> > out yet.
> 
> I tested the misc-patches branch of Will's tree on kerne.org, and looks
> the locpdep warning still can be observed.

That's the wrong tree. Try the arm64 for-next queue:

  git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core

Will

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2015-12-10 10:31 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2015-12-09  7:23 [PATCH] arm64: annotate irq off before schedule Ming Lei
2015-12-09 10:55 ` Catalin Marinas
2015-12-10  6:04   ` Ming Lei
2015-12-10 10:31     ` Will Deacon

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