Re: [PATCH][RESEND] arm: Fix flush_dcache_page() for usage from irq context

[Russell King (Oracle)]

On Fri, Aug 18, 2023 at 10:58:09PM +0200, Helge Deller wrote:
> Since at least kernel 6.1, flush_dcache_page() is called with IRQs
> disabled, e.g. from aio_complete().
> 
> But the current implementation for flush_dcache_page() on ARM (32-bit)
> unintentionally re-enables IRQs, which may lead to deadlocks.
> 
> Fix it by using xa_lock_irqsave() and xa_unlock_irqrestore()
> for the flush_dcache_mmap_*lock() macros instead.
> 
> Cc: "Russell King (Oracle)" <linux@xxxxxxxxxxxxxxx>
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx>
> Signed-off-by: Helge Deller <deller@xxxxxx>

Please submit to the patch system, details can be found in my email
signature below.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!