Re: [PATCH v7 2/4] uaccess: always export _copy_[from|to]_user with CONFIG_RUST

[Andrew Morton]

On Tue, 28 May 2024 14:58:03 +0000 Alice Ryhl <aliceryhl@xxxxxxxxxx> wrote:

> Rust code needs to be able to access _copy_from_user and _copy_to_user
> so that it can skip the check_copy_size check in cases where the length
> is known at compile-time, mirroring the logic for when C code will skip
> check_copy_size. To do this, we ensure that exported versions of these
> methods are available when CONFIG_RUST is enabled.
> 
> Alice has verified that this patch passes the CONFIG_TEST_USER_COPY test
> on x86 using the Android cuttlefish emulator.
> 
> ...
>
>  include/linux/uaccess.h | 46 ++++++++++++++++++++++++++++++++--------------
>  lib/usercopy.c          | 30 ++++--------------------------
>  2 files changed, 36 insertions(+), 40 deletions(-)

Acked-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>