am335x: 5.18.x: system stalling

[Arnd Bergmann]

On Sat, May 28, 2022 at 7:48 AM Yegor Yefremov
<yegorslists at googlemail.com> wrote:
>
> On Fri, May 27, 2022 at 4:13 PM Arnd Bergmann <arnd at arndb.de> wrote:
> >
> > On Fri, May 27, 2022 at 3:12 PM Ard Biesheuvel <ardb at kernel.org> wrote:
> > > On Fri, 27 May 2022 at 14:54, Arnd Bergmann <arnd at arndb.de> wrote:
> > > > On Fri, May 27, 2022 at 11:50 AM Yegor Yefremov <yegorslists at googlemail.com> wrote:
> > >
> > > Not just per-cpu data: there is also the 'current' global variable
> > > which gets used now instead of the user thread ID register, and this
> > > is also different between modules and the core kernel (unless
> > > CONFIG_ARM_MODULE_PLTS is disabled)
> >
> > Right, so if the percpu hack doesn't address it, this one might:
> >
> > diff --git a/arch/arm/include/asm/current.h b/arch/arm/include/asm/current.h
> > index 1e1178bf176d..306d1a4cae40 100644
> > --- a/arch/arm/include/asm/current.h
> > +++ b/arch/arm/include/asm/current.h
> > @@ -18,6 +18,8 @@ static __always_inline __attribute_const__ struct
> > task_struct *get_current(void)
> >  {
> >         struct task_struct *cur;
> >
> > +       return __current;
> > +
> >  #if __has_builtin(__builtin_thread_pointer) && \
> >      defined(CONFIG_CURRENT_POINTER_IN_TPIDRURO) && \
> >      !(defined(CONFIG_THUMB2_KERNEL) && \
>
> I have tried this patch and the system still stalls.

Ok, thanks for testing. To clarify: did you test with both the get_current() and
__my_cpu_offset() changes applied, or just the get_current() one?

       Arnd