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

[Johannes Berg]

On Wed, 2025-03-26 at 14:54 +0800, Tiwei Bie wrote:
> On 2025/3/20 16:32, Johannes Berg wrote:
> > 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.
> 
> After taking a closer look, changing the SIGWINCH handler seems to
> be tricky. It requires setting itself up as a session leader and
> configuring the controlling terminal. So it seems that it can't be
> turned into a real thread..
> 

Fair enough. Thanks for checking!

johannes