Re: [PATCH rdma-next 1/4] gcov: Open-code kmemdup() to work correctly with kernel and user space pointers

From: Linus Torvalds
Date: Wed Sep 02 2020 - 13:38:46 EST


On Wed, Sep 2, 2020 at 1:55 AM Leon Romanovsky <leon@xxxxxxxxxx> wrote:
>
> The kernel with KASAN and GCOV enabled generates the following splat
> due to the situation that gcov_info can be both user and kernel pointer.

I can't parse the above explanation..

> It is triggered by the memcpy() inside kmemdup(), so as a possible solution
> let's copy fields manually.

.. and I don't see why copying the fields manually makes a difference.

Can you explain more?

Linus