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generic-ipi: Fix kexec boot crash by initializing call_single_queue before enabling interrupts

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There is a problem that kdump(2nd kernel) sometimes hangs up due
to a pending IPI from 1st kernel. Kernel panic occurs because IPI
comes before call_single_queue is initialized.

To fix the crash, rename init_call_single_data() to call_function_init()
and call it in start_kernel() so that call_single_queue can be
initialized before enabling interrupts.

The details of the crash are:

 (1) 2nd kernel boots up

 (2) A pending IPI from 1st kernel comes when irqs are first enabled
     in start_kernel().

 (3) Kernel tries to handle the interrupt, but call_single_queue
     is not initialized yet at this point. As a result, in the
     generic_smp_call_function_single_interrupt(), NULL pointer
     dereference occurs when list_replace_init() tries to access
     &q->list.next.

Therefore this patch changes the name of init_call_single_data()
to call_function_init() and calls it before local_irq_enable()
in start_kernel().

Signed-off-by: Takao Indoh <[email protected]>
Reviewed-by: WANG Cong <[email protected]>
Acked-by: Neil Horman <[email protected]>
Acked-by: Vivek Goyal <[email protected]>
Acked-by: Peter Zijlstra <[email protected]>
Cc: Milton Miller <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
This commit is contained in:
Takao Indoh 2011-03-29 12:35:04 -04:00 • committed by Ingo Molnar
commit d8ad7d1123
3 changed files with 6 additions and 5 deletions
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5
kernel/smp.c
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@ -74,7 +74,7 @@ static struct notifier_block __cpuinitdata hotplug_cfd_notifier = {
.notifier_call = hotplug_cfd,
};
static int __cpuinit init_call_single_data(void)
void __init call_function_init(void)
{
void *cpu = (void *)(long)smp_processor_id();
int i;
@ -88,10 +88,7 @@ static int __cpuinit init_call_single_data(void)
hotplug_cfd(&hotplug_cfd_notifier, CPU_UP_PREPARE, cpu);
register_cpu_notifier(&hotplug_cfd_notifier);
return 0;
}
early_initcall(init_call_single_data);
/*
* csd_lock/csd_unlock used to serialize access to per-cpu csd resources