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

Arnd Bergmann
2023-03-29T15:42:30Z

On Wed, Mar 29, 2023, at 17:15, Oleg Nesterov wrote:
>
> This look as if access_ok() or __access_ok() doesn't depend on task, but
> this is not true in general. Say, TASK_SIZE_MAX can check is_32bit_task()
> test_thread_flag(TIF_32BIT...) and this uses "current".
>
> Again, we probably do not care, but I don't like the fact task_access_ok()
> looks as if task_access_ok(task) returns the same result as "task" calling
> access_ok().

I think the idea of TASK_SIZE_MAX is that it is a compile-time constant and in fact independent of current, while TASK_SIZE
takes TIF_32BIT into account.

Arnd