Re: [RFC PATCH -next V2 2/7] arm64: fix page_address return value in copy_highpage

[Tong Tiangen]

在 2022/4/6 18:22, Mark Rutland 写道:
> On Wed, Apr 06, 2022 at 09:13:06AM +0000, Tong Tiangen wrote:
> > Function page_address return void, fix it.
> >
> > Signed-off-by: Tong Tiangen <tongtiangen@xxxxxxxxxx>
>
> This looks like a sensible cleanup, but the commit title and message aren't
> that clear.
>
> Can you please make this:
>
> | arm64: fix types in copy_highpage()
> |
> | In copy_highpage() the `kto` and `kfrom` local variables are pointers to
> | struct page, but these are used to hold arbitrary pointers to kernel memory.
> | Each call to page_address() returns a void pointer to memory associated with
> | the relevant page, and copy_page() expects void pointers to this memory.
> |
> | This inconsistency was introduced in commit:
> |
> |   2563776b41c31908 ("arm64: mte: Tags-aware copy_{user_,}highpage() implementations")
> |
> | ... and while this doesn't appear to be harmful in practice it is clearly wrong.
> |
> | Correct this by making `kto` and `kfrom` void pointers.
> |
> | Fixes: 2563776b41c31908 ("arm64: mte: Tags-aware copy_{user_,}highpage() implementations")
>
> With that:
>
> Acked-by: Mark Rutland <mark.rutland@xxxxxxx>
>
> Thanks,
> Mark.

OK, sure , will do in next version.

Thanks.
Tong.

> > ---
> >   arch/arm64/mm/copypage.c | 4 ++--
> >   1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c
> > index b5447e53cd73..0dea80bf6de4 100644
> > --- a/arch/arm64/mm/copypage.c
> > +++ b/arch/arm64/mm/copypage.c
> > @@ -16,8 +16,8 @@
> >   
> >   void copy_highpage(struct page *to, struct page *from)
> >   {
> > -	struct page *kto = page_address(to);
> > -	struct page *kfrom = page_address(from);
> > +	void *kto = page_address(to);
> > +	void *kfrom = page_address(from);
> >   
> >   	copy_page(kto, kfrom);
> >   
> > --
> > 2.18.0.huawei.25
> >
> >
> > _______________________________________________
> > linux-arm-kernel mailing list
> > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> .