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

Andy Lutomirski
2019-11-10T16:57:05Z

On Sun, Nov 10, 2019 at 4:36 AM Thomas Gleixner <tglx@linutronix.de> wrote:
>
> On Sat, 9 Nov 2019, Thomas Gleixner wrote:
> > 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.
>
> 64bit does not have flags in the inactive_task_frame ...
>

Hmm. One more thing to unify, I guess.

--Andy