Messages in this thread | | | Date | Mon, 7 Aug 2023 21:37:00 +0100 (BST) | From | "Maciej W. Rozycki" <> | Subject | Re: [PATCH 2/5] [RESEND] x86: avoid unneeded __div64_32 function definition |
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On Wed, 2 Aug 2023, Borislav Petkov wrote:
> > --- a/arch/x86/include/asm/div64.h > > +++ b/arch/x86/include/asm/div64.h > > @@ -71,6 +71,11 @@ static inline u64 mul_u32_u32(u32 a, u32 b) > > } > > #define mul_u32_u32 mul_u32_u32 > > > > +/* > > + * __div64_32() is never called on x86, so prevent the > > + * generic definition from getting built. > > + */ > > +#define __div64_32 > > > > #else > > # include <asm-generic/div64.h> > > Yap.
Hmm, shouldn't this be something like:
#define __div64_32(n, base) BUILD_BUG()
instead?
Otherwise you risk `__div64_32(n, base)' getting expanded to `(n, base)', if the macro does get called mistakenly for some reason, and the expansion is a valid expression which may not produce a warning even, depending on usage.
Maciej
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