Re: [bug report] powerpc/mm/radix: Add tlbflush routines

[Dan Carpenter <dan.carpenter@oracle.com>]

On Wed, Jan 31, 2018 at 08:58:50PM -0800, Michael Ellerman wrote:
> Dan Carpenter <dan.carpenter@oracle.com> writes:
> 
> > Hello Aneesh Kumar K.V,
> >
> > The patch 1a472c9dba6b: "powerpc/mm/radix: Add tlbflush routines"
> > from Apr 29, 2016, leads to the following static checker warning:
> >
> > 	arch/powerpc/mm/tlb_nohash.c:218 __local_flush_tlb_page()
> > 	warn: always true condition '(pid != ~0) => (0-u32max != u64max)'
> >
> > arch/powerpc/mm/tlb_nohash.c
> >    211  void __local_flush_tlb_page(struct mm_struct *mm, unsigned long vmaddr,
> >    212                              int tsize, int ind)
> >    213  {
> >    214          unsigned int pid;
> >    215  
> >    216          preempt_disable();
> >    217          pid = mm ? mm->context.id : 0;
> >    218          if (pid != MMU_NO_CONTEXT)
> >                     ^^^^^^^^^^^^^^^^^^^^^
> >    219                  _tlbil_va(vmaddr, pid, tsize, ind);
> >    220          preempt_enable();
> >    221  }
> >
> > I don't know very much about PowerPC.  The static checker is guessing
> > which headers to pull in instead of relying on the build system so there
> > are a lot of false positives.
> 
> O_o 
> 
> That's a bit nuts ... :)
> 

Heh.

Thanks for looking into this.

regards,
dan carpenter