[PATCH 4/5] arm64: mte: Add asymmetric mode support

[Catalin Marinas]

On Mon, Sep 13, 2021 at 09:14:23AM +0100, Vincenzo Frascino wrote:
> MTE provides an asymmetric mode for detecting tag exceptions. In
> particular, when such a mode is present, the CPU triggers a fault
> on a tag mismatch during a load operation and asynchronously updates
> a register when a tag mismatch is detected during a store operation.
> 
> Add support for MTE asymmetric mode.
> 
> Note: If the CPU does not support MTE asymmetric mode the kernel falls
> back on synchronous mode which is the default for kasan=on.
> 
> Cc: Will Deacon <will at kernel.org>
> Cc: Catalin Marinas <catalin.marinas at arm.com>
> Cc: Andrey Konovalov <andreyknvl at gmail.com>
> Signed-off-by: Vincenzo Frascino <vincenzo.frascino at arm.com>

Reviewed-by: Catalin Marinas <catalin.marinas at arm.com>