Re: [PATCH v19 008/130] x86/tdx: Warning with 32bit build shift-count-overflow

[Huang, Kai]

On 5/03/2024 9:12 pm, Isaku Yamahata wrote:
> On Fri, Mar 01, 2024 at 01:36:43PM +0200,
> "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> wrote:
>
> > On Thu, Feb 29, 2024 at 11:49:13AM +1300, Huang, Kai wrote:
> > > On 26/02/2024 9:25 pm, isaku.yamahata@xxxxxxxxx wrote:
> > > > From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
> > > >
> > > > This patch fixes the following warnings.
> > > >
> > > >      In file included from arch/x86/kernel/asm-offsets.c:22:
> > > >      arch/x86/include/asm/tdx.h:92:87: warning: shift count >= width of type [-Wshift-count-overflow]
> > > >      arch/x86/include/asm/tdx.h:20:21: note: expanded from macro 'TDX_ERROR'
> > > >      #define TDX_ERROR                       _BITUL(63)
> > > >
> > > >                                              ^~~~~~~~~~
> >
> > I think you trim the warning message. I don't see the actual user of the
> > define. Define itself will not generate the warning. You need to actually
> > use it outside of preprocessor. I don't understand who would use it in
> > 32-bit code. Maybe fixing it this way masking other issue.
> >
> > That said, I don't object the change itself. We just need to understand
> > the context more.
>
> v18 used it as stub function. v19 dropped it as the stub was not needed.

Sorry I literally don't understand what you are talking about here.

Please just clarify (at least):

 - Does this problem exist in upstream code?
 - If it does, what is the root cause, and how to reproduce?