[PATCH v2] All arch: remove system call sys_sysctl

[Will Deacon]

On Thu, Jun 11, 2020 at 11:54:00AM +0800, Xiaoming Ni wrote:
> Since the commit 61a47c1ad3a4dc ("sysctl: Remove the sysctl system call"),
> sys_sysctl is actually unavailable: any input can only return an error.
> 
> We have been warning about people using the sysctl system call for years
> and believe there are no more users.  Even if there are users of this
> interface if they have not complained or fixed their code by now they
> probably are not going to, so there is no point in warning them any
> longer.
> 
> So completely remove sys_sysctl on all architectures.
> 
> Signed-off-by: Xiaoming Ni <nixiaoming at huawei.com>
> 
> changes in v2:
>   According to Kees Cook's suggestion, completely remove sys_sysctl on all arch
>   According to Eric W. Biederman's suggestion, update the commit log
> 
> V1: https://lore.kernel.org/lkml/1591683605-8585-1-git-send-email-nixiaoming@huawei.com/
>   Delete the code of sys_sysctl and return -ENOSYS directly at the function entry
> ---
>  arch/alpha/kernel/syscalls/syscall.tbl             |   2 +-
>  arch/arm/configs/am200epdkit_defconfig             |   1 -
>  arch/arm/tools/syscall.tbl                         |   2 +-
>  arch/arm64/include/asm/unistd32.h                  |   4 +-

For the arm/arm64 parts:

Acked-by: Will Deacon <will at kernel.org>

Will