Re: [PATCH 0/6] Allow signals for IO threads

[Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>]

On Thu, Apr 1, 2021 at 7:58 AM Stefan Metzmacher <metze@xxxxxxxxx> wrote:
>
> >
> > Ok, the following makes gdb happy again:
> >
> > --- a/arch/x86/kernel/process.c
> > +++ b/arch/x86/kernel/process.c
> > @@ -163,6 +163,8 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg,
> >         /* Kernel thread ? */
> >         if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
> >                 memset(childregs, 0, sizeof(struct pt_regs));
> > +               if (p->flags & PF_IO_WORKER)
> > +                       childregs->cs = current_pt_regs()->cs;
> >                 kthread_frame_init(frame, sp, arg);
> >                 return 0;
> >         }
>
> Would it be possible to fix this remaining problem before 5.12 final?

Please not that way.

But doing something like

        childregs->cs = __USER_CS;
        childregs->ss = __USER_DS;
        childregs->ds = __USER_DS;
        childregs->es = __USER_DS;

might make sense (just do it unconditionally, rather than making it
special to PF_IO_WORKER).

Does that make gdb happy too?

           Linus