Re: [PATCH] usb: gadget: ffs: ffs_aio_cancel(): Save/restore IRQ flags

["Ardelean, Alexandru" <alexandru.Ardelean@xxxxxxxxxx>]

On Wed, 2019-11-06 at 14:02 +0200, Alexandru Ardelean wrote:
> From: Lars-Peter Clausen <lars@xxxxxxxxxx>
> 
> ffs_aio_cancel() can be called from both interrupt and thread context.
> Make
> sure that the current IRQ state is saved and restored by using
> spin_{un,}lock_irq{save,restore}().
> 
> Otherwise undefined behavior might occur.

Hey,

This is a patch-ping.

Thanks
Alex

> 
> Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx>
> ---
>  drivers/usb/gadget/function/f_fs.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/gadget/function/f_fs.c
> b/drivers/usb/gadget/function/f_fs.c
> index 59d9d512dcda..ed3bcbb84b95 100644
> --- a/drivers/usb/gadget/function/f_fs.c
> +++ b/drivers/usb/gadget/function/f_fs.c
> @@ -1160,18 +1160,19 @@ static int ffs_aio_cancel(struct kiocb *kiocb)
>  {
>  	struct ffs_io_data *io_data = kiocb->private;
>  	struct ffs_epfile *epfile = kiocb->ki_filp->private_data;
> +	unsigned long flags;
>  	int value;
>  
>  	ENTER();
>  
> -	spin_lock_irq(&epfile->ffs->eps_lock);
> +	spin_lock_irqsave(&epfile->ffs->eps_lock, flags);
>  
>  	if (likely(io_data && io_data->ep && io_data->req))
>  		value = usb_ep_dequeue(io_data->ep, io_data->req);
>  	else
>  		value = -EINVAL;
>  
> -	spin_unlock_irq(&epfile->ffs->eps_lock);
> +	spin_unlock_irqrestore(&epfile->ffs->eps_lock, flags);
>  
>  	return value;
>  }