[PATCH v3 4/4] um: Prohibit the VM_CLONE flag in run_helper_thread()

[Johannes Berg]

On Wed, 2025-03-19 at 21:55 +0800, Tiwei Bie wrote:
> Directly creating helper threads with VM_CLONE using clone can
> compromise the thread safety of errno. Since all these helper
> threads have been converted to use os_run_helper_thread(), let's
> prevent using this flag in run_helper_thread().
> 

I notice that now there's only one user left, the SIGWINCH handler,
maybe we could change that too? Anyway not related to this patch, of
course.

johannes