Re: [tip:irq/urgent] mfd/asic3: Fix race in installing chained IRQ handler

[Lee Jones <lee.jones@linaro.org>]

On Fri, 26 Jun 2015, tip-bot for Thomas Gleixner wrote:

> Commit-ID:  c30e30478c74e5be2fa3bbe954084a31f0d60570
> Gitweb:     http://git.kernel.org/tip/c30e30478c74e5be2fa3bbe954084a31f0d60570
> Author:     Thomas Gleixner <tglx@linutronix.de>
> AuthorDate: Sun, 21 Jun 2015 20:16:06 +0200
> Committer:  Thomas Gleixner <tglx@linutronix.de>
> CommitDate: Thu, 25 Jun 2015 11:56:52 +0200
> 
> mfd/asic3: Fix race in installing chained IRQ handler
> 
> Fix a race where a pending interrupt could be received and the handler
> called before the handler's data has been setup, by converting to
> irq_set_chained_handler_and_data().
> 
> Search and conversion was done with coccinelle:
> 
> @@
> expression E1, E2, E3;
> @@
> (
> -if (irq_set_chained_handler(E1, E3) != 0)
> -   BUG();
> |
> -irq_set_chained_handler(E1, E3);
> )
> -irq_set_handler_data(E1, E2);
> +irq_set_chained_handler_and_data(E1, E3, E2);
> 
> @@
> expression E1, E2, E3;
> @@
> (
> -if (irq_set_chained_handler(E1, E3) != 0)
> -   BUG();
> ...
> |
> -irq_set_chained_handler(E1, E3);
> ...
> )
> -irq_set_handler_data(E1, E2);
> +irq_set_chained_handler_and_data(E1, E3, E2);
> 
> Reported-by: Russell King <rmk+kernel@arm.linux.org.uk>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Cc: Julia Lawall <Julia.Lawall@lip6.fr>
> Cc: Samuel Ortiz <sameo@linux.intel.com>
> Cc: Lee Jones <lee.jones@linaro.org>
> ---
>  drivers/mfd/asic3.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)

Applied to MFD -fixes.

> diff --git a/drivers/mfd/asic3.c b/drivers/mfd/asic3.c
> index 977bd3a..120df5c 100644
> --- a/drivers/mfd/asic3.c
> +++ b/drivers/mfd/asic3.c
> @@ -417,9 +417,8 @@ static int __init asic3_irq_probe(struct platform_device *pdev)
>  	asic3_write_register(asic, ASIC3_OFFSET(INTR, INT_MASK),
>  			     ASIC3_INTMASK_GINTMASK);
>  
> -	irq_set_chained_handler(asic->irq_nr, asic3_irq_demux);
> +	irq_set_chained_handler_and_data(asic->irq_nr, asic3_irq_demux, asic);
>  	irq_set_irq_type(asic->irq_nr, IRQ_TYPE_EDGE_RISING);
> -	irq_set_handler_data(asic->irq_nr, asic);
>  
>  	return 0;
>  }

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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