[External] Re: [PATCH v8 1/3] riscv: io: avoid null-pointer arithmetic in PIO helpers

[yunhui cui]

Hi Paul,

On Tue, Jul 14, 2026 at 2:04 AM Paul Walmsley <pjw at kernel.org> wrote:
>
> On Fri, 3 Jul 2026, Yunhui Cui wrote:
>
> > When port I/O is not supported, exposing the port-string helpers is both
> > unnecessary and can make clang diagnose null-pointer arithmetic from the
> > PCI_IOBASE based address expression.  Keep the MMIO string helpers
> > available as before, but only provide the port I/O variants when
> > CONFIG_HAS_IOPORT is enabled.
> >
> > Signed-off-by: Yunhui Cui <cuiyunhui at bytedance.com>
> > Reviewed-by: Arnd Bergmann <arnd at arndb.de>
>
> Thanks, queued for v7.2-rc.

Thanks for queuing patch 1.

That patch is independent and safe to take as-is.

For patches 2/3, we later found that the percpu try_cmpxchg fallback path can
expose a variable-shadowing issue in the current RISC-V cmpxchg macro
implementation in arch/riscv/include/asm/cmpxchg.h.

I'll address that in the next revision of the percpu patches, so please just
take patch 1 from v8 for now.

>
>
> - Paul


Thanks,
Yunhui