[PATCH 0/9] Fix unsafe disable_irq usage

From: Ben Nizette
Date: Thu Apr 16 2009 - 01:54:49 EST


After being bitten by unsafe usage of disable_irq from within that irq's
handler [1], I went through and used Coccinelle to audit the rest of
drivers/ too. This turned up 9 more unsafe usages.

As Haavard pointed out in that thread, disable_irq waits for running
handlers of an irq to complete before returning. When a handler
disable_irq's its own irq then we see a deadlock.

Note that this wasn't actually observed in the wild until the recent
merge of

commit 3aa551c9b4c40018f0e261a178e3d25478dc04a9
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Date: Mon Mar 23 18:28:15 2009 +0100

genirq: add threaded interrupt handler support

Add support for threaded interrupt handlers



Regards,
--Ben.


[1] http://lkml.org/lkml/2009/4/15/498

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/