[tip:irq/urgent] genirq: try_one_irq() must be called with irq disabled

From: tip-bot for Yong Zhang
Date: Sat Nov 07 2009 - 15:49:18 EST


Commit-ID: e7e7e0c084ef862d5754701108d4a038514d6314
Gitweb: http://git.kernel.org/tip/e7e7e0c084ef862d5754701108d4a038514d6314
Author: Yong Zhang <yong.zhang0@xxxxxxxxx>
AuthorDate: Sat, 7 Nov 2009 11:16:13 +0800
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Sat, 7 Nov 2009 21:44:45 +0100

genirq: try_one_irq() must be called with irq disabled

Prarit reported:
=================================
[ INFO: inconsistent lock state ]
2.6.32-rc5 #1
---------------------------------
inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
swapper/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
(&irq_desc_lock_class){?.-...}, at: [<ffffffff810c264e>] try_one_irq+0x32/0x138
{IN-HARDIRQ-W} state was registered at:
[<ffffffff81095160>] __lock_acquire+0x2fc/0xd5d
[<ffffffff81095cb4>] lock_acquire+0xf3/0x12d
[<ffffffff814cdadd>] _spin_lock+0x40/0x89
[<ffffffff810c3389>] handle_level_irq+0x30/0x105
[<ffffffff81014e0e>] handle_irq+0x95/0xb7
[<ffffffff810141bd>] do_IRQ+0x6a/0xe0
[<ffffffff81012813>] ret_from_intr+0x0/0x16
irq event stamp: 195096
hardirqs last enabled at (195096): [<ffffffff814cd7f7>] _spin_unlock_irq+0x3a/0x5c
hardirqs last disabled at (195095): [<ffffffff814cdbdd>] _spin_lock_irq+0x29/0x95
softirqs last enabled at (195088): [<ffffffff81068c92>] __do_softirq+0x1c1/0x1ef
softirqs last disabled at (195093): [<ffffffff8101304c>] call_softirq+0x1c/0x30

other info that might help us debug this:
1 lock held by swapper/0:
#0: (kernel/irq/spurious.c:21){+.-...}, at: [<ffffffff81070cf2>]
run_timer_softirq+0x1a9/0x315

stack backtrace:
Pid: 0, comm: swapper Not tainted 2.6.32-rc5 #1
Call Trace:
<IRQ> [<ffffffff81093e94>] valid_state+0x187/0x1ae
[<ffffffff81093fe4>] mark_lock+0x129/0x253
[<ffffffff810951d4>] __lock_acquire+0x370/0xd5d
[<ffffffff81095cb4>] lock_acquire+0xf3/0x12d
[<ffffffff814cdadd>] _spin_lock+0x40/0x89
[<ffffffff810c264e>] try_one_irq+0x32/0x138
[<ffffffff810c2795>] poll_all_shared_irqs+0x41/0x6d
[<ffffffff810c27dd>] poll_spurious_irqs+0x1c/0x49
[<ffffffff81070d82>] run_timer_softirq+0x239/0x315
[<ffffffff81068bd3>] __do_softirq+0x102/0x1ef
[<ffffffff8101304c>] call_softirq+0x1c/0x30
[<ffffffff81014b65>] do_softirq+0x59/0xca
[<ffffffff810686ad>] irq_exit+0x58/0xae
[<ffffffff81029b84>] smp_apic_timer_interrupt+0x94/0xba
[<ffffffff81012a33>] apic_timer_interrupt+0x13/0x20

The reason is that try_one_irq() is called from hardirq context with
interrupts disabled and from softirq context (poll_all_shared_irqs())
with interrupts enabled.

Disable interrupts before calling it from poll_all_shared_irqs().

Reported-and-tested-by: Prarit Bhargava <prarit@xxxxxxxxxx>
Signed-off-by: Yong Zhang <yong.zhang0@xxxxxxxxx>
LKML-Reference: <1257563773-4620-1-git-send-email-yong.zhang0@xxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
kernel/irq/spurious.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index 114e704..bd7273e 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -121,7 +121,9 @@ static void poll_all_shared_irqs(void)
if (!(status & IRQ_SPURIOUS_DISABLED))
continue;

+ local_irq_disable();
try_one_irq(i, desc);
+ local_irq_enable();
}
}

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