Re: [PATCH] x86/kexec: Add a comment to relocate_kernel() for better readability

From: Huang, Kai
Date: Thu Jun 08 2023 - 00:44:19 EST


On Wed, 2023-06-07 at 14:19 +0300, kirill.shutemov@xxxxxxxxxxxxxxx wrote:
> On Wed, Jun 07, 2023 at 10:39:10PM +1200, Kai Huang wrote:
> > The reason to save %rcx to %r11 before calling swap_pages isn't that
> > obvious w/o looking into the swap_pages itself. Add a comment to
> > improve the readability.
> >
> > Signed-off-by: Kai Huang <kai.huang@xxxxxxxxx>
> > ---
> > arch/x86/kernel/relocate_kernel_64.S | 4 ++++
> > 1 file changed, 4 insertions(+)
> >
> > diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S
> > index 56cab1bb25f5..97deae3c5e6c 100644
> > --- a/arch/x86/kernel/relocate_kernel_64.S
> > +++ b/arch/x86/kernel/relocate_kernel_64.S
> > @@ -169,6 +169,10 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
> > wbinvd
> > 1:
> >
> > + /*
> > + * Save the preserve_context to %r11 as
> > + * swap_pages clobbers %rcx.
> > + */
>
> Line split is not needed. It fits nicely under 80-characters.
>
> + /* Save the preserve_context to %r11 as swap_pages clobbers %rcx. */
>
> Otherwise, LGTM.

Sure. Will do.

With above change, may I add your Acked-by ? :)

>
> > movq %rcx, %r11
> > call swap_pages
> >
> >
> > base-commit: 409bf2895d71bb68bc5b8589036e5ed1ca30bada
> > --
> > 2.40.1
> >
>