Re: [PATCHv4 01/30] x86/mm: Fix warning on build with X86_MEM_ENCRYPT=y

Kirill A. Shutemov
2022-02-28T16:21:30Z

On Sun, Feb 27, 2022 at 02:01:30PM -0800, Josh Poimboeuf wrote:
> On Thu, Feb 24, 2022 at 06:56:01PM +0300, Kirill A. Shutemov wrote:
> > So far, AMD_MEM_ENCRYPT is the only user of X86_MEM_ENCRYPT. TDX will be
> > the second. It will make mem_encrypt.c build without AMD_MEM_ENCRYPT,
> > which triggers a warning:
> >
> > arch/x86/mm/mem_encrypt.c:69:13: warning: no previous prototype for
> > function 'mem_encrypt_init' [-Wmissing-prototypes]
> >
> > Fix it by moving mem_encrypt_init() declaration outside of #ifdef
> > CONFIG_AMD_MEM_ENCRYPT.
> >
> > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> > Fixes: 20f07a044a76 ("x86/sev: Move common memory encryption code to mem_encrypt.c")
> > Acked-by: David Rientjes <rientjes@google.com>
>
> The patch title, warning, and "Fixes" tag tend to give the impression
> this is fixing a real user-visible bug. But the bug is theoretical, as
> it's not possible to enable X86_MEM_ENCRYPT without AMD_MEM_ENCRYPT,
> until patch 27.
>
> IMO it would be preferable to just squash this change with patch 27.
>
> Having it as a separate patch is also fine, but it shouldn't be
> described as a fix or use the Fixes tag. It's more of a preparatory
> patch.

maintainer-tip.rst seems disagree with you:

A Fixes tag should be added even for changes which do not need to be
backported to stable kernels, i.e. when addressing a recently introduced
issue which only affects tip or the current head of mainline.

I will leave it as is.

--
Kirill A. Shutemov