Re: [PATCH] mm: move phys_mem_access_prot_allowed to header

[Rosen Penev]

On Mon, May 4, 2026 at 10:54 PM Arnd Bergmann <arnd@xxxxxxxx> wrote:
>
> On Tue, May 5, 2026, at 03:01, Rosen Penev wrote:
> > phys_mem_access_prot_allowed is only implemented for X86. For others, it
> > returns 1. Move it to header to avoid using __weak.
> >
> > Fixes compilation with make LLVM=1 ARCH=mips
>
> Can you describe what exactly goes wrong here on mips?
Cannot find symbol for section 4: .text.phys_mem_access_prot_allowed.
drivers/char/mem.o: failed

It's full of similar errors in drivers/pci/ as well. clang on MIPS
doesn't seem to like __weak.
>
> > @@ -239,12 +239,6 @@ static ssize_t write_mem(struct file *file, const
> > char __user *buf,
> >       return written;
> >  }
> >
> > -int __weak phys_mem_access_prot_allowed(struct file *file,
> > -     unsigned long pfn, unsigned long size, pgprot_t *vma_prot)
> > -{
> > -     return 1;
> > -}
> > -
>
> Removing __weak functions is usually an improvement, but I think
> we can go further here, see the discussion from last year at
>
> https://lore.kernel.org/all/20250520152030.1499670-1-arnd@xxxxxxxxxx/#t
I hold no opinion on that.
>
>      Arnd