Re: [BUG] next-20081216 - WARNING: at kernel/smp.c:333smp_call_function_mask

[Ingo Molnar]

* Kamalesh Babulal <kamalesh@xxxxxxxxxxxxxxxxxx> wrote:

> * Ingo Molnar <mingo@xxxxxxx> [2008-12-27 09:39:36]:
> 
> > 
> > * Ingo Molnar <mingo@xxxxxxx> wrote:
> > 
> > > * Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
> > > 
> > > > +extern int arch_init_chip_data(struct irq_desc *desc, int cpu);
> > > 
> > > when you change a function declaration's return type, you _must_ double 
> > > check whether you properly updated all instances of that function. In 
> > > this case you forgot about the io_apic.c instance.
> > 
> > the corrected patch is below.
> > 
> > 	Ingo
> >
> 
> > --------------->
> > From d353c528bbb29be434f7688cba9b59781e9151e3 Mon Sep 17 00:00:00 2001
> > From: Yinghai Lu <yinghai@xxxxxxxxxx>
> > Date: Fri, 26 Dec 2008 02:05:47 -0800
> > Subject: [PATCH] sparseirq: work around compiler optimizing away __weak functions
> > 
> > Impact: fix panic on null pointer with sparseirq
> > 
> > Some GCC versions seem to inline the weak global function,
> > when that function is empty.
> > 
> > Work it around, by making the functions return a (dummy) integer.
> > 
> > Signed-off-by: Yinghai <yinghai@xxxxxxxxxx>
> > Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
> > ---
> >  arch/x86/kernel/io_apic.c |    6 ++++--
> >  include/linux/irq.h       |    6 +++---
> >  init/main.c               |    7 ++++---
> >  kernel/irq/handle.c       |    7 ++++---
> >  4 files changed, 15 insertions(+), 11 deletions(-)
> > 
> > diff --git a/arch/x86/kernel/io_apic.c b/arch/x86/kernel/io_apic.c
> > index 2fe543f..e4d4d19 100644
> > --- a/arch/x86/kernel/io_apic.c
> > +++ b/arch/x86/kernel/io_apic.c
> > @@ -170,7 +170,7 @@ static struct irq_cfg irq_cfgx[NR_IRQS] = {
> >  	[15] = { .domain = CPU_MASK_ALL, .vector = IRQ15_VECTOR, },
> >  };
> > 
> > -void __init arch_early_irq_init(void)
> > +int __init arch_early_irq_init(void)
> >  {
> >  	struct irq_cfg *cfg;
> >  	struct irq_desc *desc;
> > @@ -184,6 +184,8 @@ void __init arch_early_irq_init(void)
> >  		desc = irq_to_desc(i);
> >  		desc->chip_data = &cfg[i];
> >  	}
> > +
> > +	return 0;
> >  }
> > 
> >  #ifdef CONFIG_SPARSE_IRQ
> > @@ -212,7 +214,7 @@ static struct irq_cfg *get_one_free_irq_cfg(int cpu)
> >  	return cfg;
> >  }
> > 
> > -void arch_init_chip_data(struct irq_desc *desc, int cpu)
> > +int arch_init_chip_data(struct irq_desc *desc, int cpu)
> >  {
> >  	struct irq_cfg *cfg;
> 
> the return statement is missing in the patch.

yes, indeed - updated patch below.

	Ingo

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