Re: [PATCHv3] irqchip: arm-gic: take gic_lock when updating irq type

[Greg KH <gregkh@linuxfoundation.org>]

On Wed, Mar 28, 2018 at 02:24:30PM +0530, Aniruddha Banerjee wrote:
> The kernel documentation states that the locking of the irq-chip
> registers should be handled by the irq-chip driver. In the irq-gic,
> the accesses to the irqchip are seemingly not protected and multiple
> writes to SPIs from different irq descriptors do RMW requests without
> taking the irq-chip lock. When multiple irqs call the request_irq at
> the same time, there can be a simultaneous write at the gic
> distributor, leading to a race. Acquire the gic_lock when the
> irq_type is updated.
> 
> Signed-off-by: Aniruddha Banerjee <aniruddhab@nvidia.com>
> ---
> Changes from V1:
> 
> * Moved the spinlock from irq-gic to irq-gic common, so that the fix
> is valid for GIC v1/v2/v3.
> 
> Change from V2:
> 
> * Fixup the Signed-off-by line.
> 
>  drivers/irqchip/irq-gic-common.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)

<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree.  Please read:
    https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.

</formletter>