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SubjectRe: [PATCH] irqchip/atmel-aic: Fix potential deadlock in ->xlate()
On Tue, 13 Sep 2016, Boris Brezillon wrote:

> aic5_irq_domain_xlate() and aic_irq_domain_xlate() take the generic chip
> lock without disabling interrupts, which can lead to a deadlock if an
> interrupt occurs while the lock is held in one of these functions.
>
> Replace irq_gc_{lock,unlock}() calls by
> raw_spin_{lock_irqsave,unlock_irqrestore}() ones to prevent this bug from
> happening.
>
> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> Fixes: b1479ebb7720 ("irqchip: atmel-aic: Add atmel AIC/AIC5 drivers")
> Cc: <stable@kernel.vger.org>
> ---
> drivers/irqchip/irq-atmel-aic.c | 5 +++--
> drivers/irqchip/irq-atmel-aic5.c | 5 +++--
> 2 files changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/irqchip/irq-atmel-aic.c b/drivers/irqchip/irq-atmel-aic.c
> index 112e17c2768b..447a8b0f1395 100644
> --- a/drivers/irqchip/irq-atmel-aic.c
> +++ b/drivers/irqchip/irq-atmel-aic.c
> @@ -176,6 +176,7 @@ static int aic_irq_domain_xlate(struct irq_domain *d,
> {
> struct irq_domain_chip_generic *dgc = d->gc;
> struct irq_chip_generic *gc;
> + unsigned long flags;
> unsigned smr;
> int idx;
> int ret;
> @@ -194,11 +195,11 @@ static int aic_irq_domain_xlate(struct irq_domain *d,
>
> gc = dgc->gc[idx];
>
> - irq_gc_lock(gc);
> + raw_spin_lock_irqsave(&gc->lock, flags);

Please provide a primitive, i.e. irq_gc_lock_irqsave(), for it.

Thanks,

tglx

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