Re: irq_desc_lock_class is held when it is freed

[Yinghai Lu <yinghai@kernel.org>]

Eric Paris wrote:
> I have an hp dl785g5 which is unable to successfully run
> 2.6.29-0.66.rc3.fc11.x86_64 or 2.6.29-rc2-next-20090126.  During bootup
> (early in userspace daemons starting) I get the below BUG, which quickly
> renders the machine dead.  I assume it is because sparse_irq_lock never
> gets released when the BUG kills that task.  But maybe it dies for some
> other reason, but the machine is dead, gotta hit the vitual power
> button.
> 
> setting CONFIG_NUMA_MIGRATE_IRQ_DESC=n allowed me to successfully boot
> the linux-next kernel.  2.6.28 booted and worked fine (although it
> doesn't have this config option, so that isn't surprising.)
> 
> attached you will find the linux-next config and dmesg output from the
> machine in question when booted using linux-next WITHOUT the
> MIGRATE_IRQ_DESC.  The only difference between the working and broken
> config is if CONFIG_NUMA_MIGRATE_IRQ_DESC is set or not.
> 
> Please if there is anything I can collect, test, or do, don't hesitate
> to let me know.
> 
it seems there is some merge problem... also there could be another problem...

please check

diff --git a/arch/x86/kernel/io_apic.c b/arch/x86/kernel/io_apic.c
index 6c02c25..610ce0a 100644
--- a/arch/x86/kernel/io_apic.c
+++ b/arch/x86/kernel/io_apic.c
@@ -2511,14 +2511,15 @@ static void irq_complete_move(struct irq_desc **descp)
 
 	vector = ~get_irq_regs()->orig_ax;
 	me = smp_processor_id();
+
+	if (vector == cfg->vector && cpumask_test_cpu(me, cfg->domain)) {
 #ifdef CONFIG_NUMA_MIGRATE_IRQ_DESC
 		*descp = desc = move_irq_desc(desc, me);
 		/* get the new one */
 		cfg = desc->chip_data;
 #endif
-
-	if (vector == cfg->vector && cpumask_test_cpu(me, cfg->domain))
 		send_cleanup_vector(cfg);
+	}
 }
 #else
 static inline void irq_complete_move(struct irq_desc **descp) {}