Re: [PATCH v14 1/4] asm-generic,arm64: create task variant of access_ok

From: Arnd Bergmann
Date: Tue Mar 28 2023 - 14:46:38 EST


On Tue, Mar 28, 2023, at 18:48, Gregory Price wrote:
> On arm64, access_ok makes adjustments to pointers based on whether
> memory tagging is enabled for a task (ARM MTE). When leveraging ptrace,
> it's possible for a task to enable/disable various kernel features (such
> as syscall user dispatch) which require user points as arguments.
>
> To enable Task A to set these features via ptrace with Task B's
> pointers, a task variant of access_ok is required for architectures with
> features such as memory tagging.
>
> If the architecture does not implement task_access_ok, the operation
> reduces to access_ok and the task argument is discarded.
>
> Signed-off-by: Gregory Price <gregory.price@xxxxxxxxxxxx>

For asm-generic:

Acked-by: Arnd Bergmann <arnd@xxxxxxxx>