Re: [patch 2/9] x86/process: Unify copy_thread_tls()

Thomas Gleixner
2019-11-08T23:43:16Z

On Fri, 8 Nov 2019, Andy Lutomirski wrote:
> On 11/6/19 11:35 AM, Thomas Gleixner wrote:
> > +static inline int copy_io_bitmap(struct task_struct *tsk)
> > +{
> > + if (likely(!test_tsk_thread_flag(current, TIF_IO_BITMAP)))
> > + return 0;
> > +
> > + tsk->thread.io_bitmap_ptr = kmemdup(current->thread.io_bitmap_ptr,
> > + IO_BITMAP_BYTES, GFP_KERNEL);
>
> tsk->thread.io_bitmap_max = current->thread.io_bitmap_max?
>
> I realize you inherited this from the code you're refactoring, but it
> does seem to be missing.

It already got copied with the task struct :)

> > +#ifdef CONFIG_X86_64
> > + savesegment(gs, p->thread.gsindex);
> > + p->thread.gsbase = p->thread.gsindex ? 0 : current->thread.gsbase;
> > + savesegment(fs, p->thread.fsindex);
> > + p->thread.fsbase = p->thread.fsindex ? 0 : current->thread.fsbase;
> > + savesegment(es, p->thread.es);
> > + savesegment(ds, p->thread.ds);
> > +#else
> > + /* Clear all status flags including IF and set fixed bit. */
> > + frame->flags = X86_EFLAGS_FIXED;
> > +#endif
>
> Want to do another commit to make the eflags fixup unconditional? I'm
> wondering if we have a bug.

Let me look at that.

Thanks,

tglx