Re: [PATCH 0/7] Fix CLONE_SETTLS with clone3

From: Christian Brauner
Date: Thu Jan 02 2020 - 13:11:21 EST

On Thu, Jan 02, 2020 at 06:24:06PM +0100, Amanieu d'Antras wrote:
> The clone3 syscall is currently broken when used with CLONE_SETTLS on all
> architectures that don't have an implementation of copy_thread_tls. The old
> copy_thread function handles CLONE_SETTLS by reading the new TLS value from
> pt_regs containing the clone syscall parameters. Since clone3 passes the TLS
> value in clone_args, this results in the TLS register being initialized to a
> garbage value.
> This patch series implements copy_thread_tls on all architectures that currently
> define __ARCH_WANT_SYS_CLONE3 and adds a compile-time check to ensure that any
> architecture that enables clone3 in the future also implements copy_thread_tls.
> I have also included a minor fix for the arm64 uapi headers which caused
> __NR_clone3 to be missing from the exported user headers.
> I have only tested this on arm64, but the copy_thread_tls implementations for
> the various architectures are fairly straightforward.

The series looks straightforward to me but I'd like a few Acks from some
of the arch maintainers before taking this.

Acked-by: Christian Brauner <christian.brauner@xxxxxxxxxx>