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

Kirill A. Shutemov
2024-03-01T11:36:47Z

On Thu, Feb 29, 2024 at 11:49:13AM +1300, Huang, Kai wrote:
>
>
> On 26/02/2024 9:25 pm, isaku.yamahata@intel.com wrote:
> > From: Isaku Yamahata <isaku.yamahata@intel.com>
> >
> > 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.

--
Kiryl Shutsemau / Kirill A. Shutemov