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

From: Isaku Yamahata
Date: Tue Mar 05 2024 - 03:13:15 EST


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.
--
Isaku Yamahata <isaku.yamahata@xxxxxxxxxxxxxxx>