Hi, Nikolaus,
On Wed, Apr 7, 2021 at 2:57 PM H. Nikolaus Schaller <hns@xxxxxxxxxxxxx> wrote:
>
>
> > Am 07.04.2021 um 08:29 schrieb Huacai Chen <chenhuacai@xxxxxxxxxx>:
> >
> > There are three errors in div64.h caused by commit c21004cd5b4cb7d479514
> > ("MIPS: Rewrite <asm/div64.h> to work with gcc 4.4.0."):
> >
> > 1, Only 32bit kernel need __div64_32(), but the above commit makes it
> > depend on 64bit kernel by mistake.
> >
> > 2, asm-generic/div64.h should be included after __div64_32() definition.
> >
> > 3, __n should be initialized as *n before use (and "*__n >> 32" should
> > be "__n >> 32") in __div64_32() definition.
> >
> > Fixes: c21004cd5b4cb7d479514 ("MIPS: Rewrite <asm/div64.h> to work with gcc 4.4.0.")
> > Cc: stable@xxxxxxxxxxxxxxx
> > Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
> > ---
> > arch/mips/include/asm/div64.h | 10 +++++-----
> > 1 file changed, 5 insertions(+), 5 deletions(-)
> >
> > diff --git a/arch/mips/include/asm/div64.h b/arch/mips/include/asm/div64.h
> > index dc5ea5736440..3be2318f8e0e 100644
> > --- a/arch/mips/include/asm/div64.h
> > +++ b/arch/mips/include/asm/div64.h
> > @@ -9,9 +9,7 @@
> > #ifndef __ASM_DIV64_H
> > #define __ASM_DIV64_H
> >
> > -#include <asm-generic/div64.h>
> > -
> > -#if BITS_PER_LONG == 64
> > +#if BITS_PER_LONG == 32
> >
> > #include <linux/types.h>
> >
> > @@ -24,9 +22,9 @@
> > unsigned long __cf, __tmp, __tmp2, __i; \
> > unsigned long __quot32, __mod32; \
> > unsigned long __high, __low; \
> > - unsigned long long __n; \
> > + unsigned long long __n = *n; \
> > \
> > - __high = *__n >> 32; \
> > + __high = __n >> 32; \
> > __low = __n; \
> > __asm__( \
> > " .set push \n" \
> > @@ -65,4 +63,6 @@
> >
> > #endif /* BITS_PER_LONG == 64 */
>
> IMHO these #if/else/endif comments should also be fixed.
>
> >
> > +#include <asm-generic/div64.h>
> > +
> > #endif /* __ASM_DIV64_H */
> > --
> > 2.27.0
> >
>
> compiles fine now. But I still get a linker issue:
>
> fs/ubifs/budget.o: In function `div_u64_rem':
> fs/ubifs/budget.c:(.text+0x1fc): undefined reference to `__div64_32'
> fs/ubifs/lpt.o: In function `div_u64_rem':
> fs/ubifs/lpt.c:(.text+0x8fc): undefined reference to `__div64_32'
> make[2]: *** [vmlinux] Error 1
> make[1]: *** [__build_one_by_one] Error 2
> make: *** [__sub-make] Error 2
Oh, there is the 4th bug in this file....
linux/types.h should be included at the first place, otherwise
BITS_PER_LONG is not defined...
Huacai
>
> BR and thanks,
> Nikolaus Schaller
>
