Hi, Nikolaus,

On Wed, Apr 7, 2021 at 2:57 PM H. Nikolaus Schaller hns@goldelico.com wrote:

...

Am 07.04.2021 um 08:29 schrieb Huacai Chen chenhuacai@kernel.org:

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@vger.kernel.org Signed-off-by: Huacai Chen chenhuacai@loongson.cn

---

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