[Letux-kernel] [PATCH] MIPS: Fix a longstanding error in div64.h

[Huacai Chen]

Hi, Maciej,

On Wed, Apr 7, 2021 at 6:22 AM Maciej W. Rozycki <macro at orcam.me.uk> wrote:
>
> On Tue, 6 Apr 2021, Zhou Yanjie wrote:
>
> > So it seems not a compiler problem.
>
>  This code is rather broken in an obvious way, starting from:
>
>         unsigned long long __n;                                         \
>                                                                         \
>         __high = *__n >> 32;                                            \
>         __low = __n;                                                    \
>
> where `__n' is used uninitialised.  Since this is my code originally I'll
> look into it; we may want to reinstate `do_div' too, which didn't have to
> be removed in the first place.
I think we can reuse the generic do_div().

>
>  Also commit e8e4eb0fbeda ("asm-generic/div64: Fix documentation of
> do_div() parameter") was an incomplete documentation fix.
>
>  Huacai, thanks for your investigation!  Please be more careful in
> verifying your future submissions however.
Sorry, I thought there is only one bug in div64.h, but in fact there
are three...

Huacai
>
>   Maciej