Re: [linux-next:master 10159/12060] arch/arm64/include/asm/pgtable.h:1102:16: error: implicit declaration of function 'pud_valid'; did you mean 'pmd_valid'?

[Ryan Roberts <ryan.roberts@arm.com>]

On 08/05/2024 15:24, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> head:   e7b4ef8fffaca247809337bb78daceb406659f2d
> commit: f0f5863a0fb0fb48a5881c3f6acca1958899dd76 [10159/12060] arm64/mm: Remove PTE_PROT_NONE bit
> config: arm64-randconfig-r013-20230528 (https://download.01.org/0day-ci/archive/20240508/202405082221.43rfWxz5-lkp@intel.com/config)
> compiler: aarch64-linux-gcc (GCC) 13.2.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240508/202405082221.43rfWxz5-lkp@intel.com/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202405082221.43rfWxz5-lkp@intel.com/
> 
> All errors (new ones prefixed by >>):
> 
>    In file included from include/linux/pgtable.h:6,
>                     from arch/arm64/include/asm/io.h:12,
>                     from include/linux/io.h:13,
>                     from include/linux/irq.h:20,
>                     from include/asm-generic/hardirq.h:17,
>                     from arch/arm64/include/asm/hardirq.h:17,
>                     from include/linux/hardirq.h:11,
>                     from include/linux/interrupt.h:11,
>                     from include/linux/trace_recursion.h:5,
>                     from include/linux/ftrace.h:10,
>                     from arch/arm64/kernel/asm-offsets.c:12:
>    arch/arm64/include/asm/pgtable.h: In function 'pud_user_accessible_page':
>>> arch/arm64/include/asm/pgtable.h:1102:16: error: implicit declaration of function 'pud_valid'; did you mean 'pmd_valid'? [-Werror=implicit-function-declaration]
>     1102 |         return pud_valid(pud) && !pud_table(pud) && (pud_user(pud) || pud_user_exec(pud));
>          |                ^~~~~~~~~
>          |                pmd_valid

Hi Will,

Looks like this is due to pud_valid() not being defined for
CONFIG_PGTABLE_LEVELS <= 2. Seems to me that this is the cleanest solution. But
pgtable folding breaks my brain so perhaps there is a better way?

What's the process here? Can you just merge this into the broken patch, or do I
need to re-post the series, or post a fix patch formally?

--8<----

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index c60dcb455ebd..f8efbc128446 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -810,6 +810,7 @@ static inline pmd_t *pud_pgtable(pud_t pud)

 #else

+#define pud_valid(pud)         false
 #define pud_page_paddr(pud)    ({ BUILD_BUG(); 0; })
 #define pud_user_exec(pud)     pud_user(pud) /* Always 0 with folding */

--8<----

Thanks,
Ryan


>    cc1: some warnings being treated as errors
>    make[3]: *** [scripts/Makefile.build:117: arch/arm64/kernel/asm-offsets.s] Error 1
>    make[3]: Target 'prepare' not remade because of errors.
>    make[2]: *** [Makefile:1197: prepare0] Error 2
>    make[2]: Target 'prepare' not remade because of errors.
>    make[1]: *** [Makefile:240: __sub-make] Error 2
>    make[1]: Target 'prepare' not remade because of errors.
>    make: *** [Makefile:240: __sub-make] Error 2
>    make: Target 'prepare' not remade because of errors.
> 
> 
> vim +1102 arch/arm64/include/asm/pgtable.h
> 
>   1099	
>   1100	static inline bool pud_user_accessible_page(pud_t pud)
>   1101	{
>> 1102		return pud_valid(pud) && !pud_table(pud) && (pud_user(pud) || pud_user_exec(pud));
>   1103	}
>   1104	#endif
>   1105	
>