Re: [PATCH v1] microblaze: tag highmem_setup() with __meminit

[Oscar Salvador]

On Mon, Mar 01, 2021 at 12:47:49PM +0100, David Hildenbrand wrote:
> With commit a0cd7a7c4bc0 ("mm: simplify free_highmem_page() and
> free_reserved_page()") the kernel test robot complains about a warning:
> 
> WARNING: modpost: vmlinux.o(.text.unlikely+0x23ac): Section mismatch in
>   reference from the function highmem_setup() to the function
>   .meminit.text:memblock_is_reserved()
> 
> This has been broken ever since microblaze added highmem support,
> because memblock_is_reserved() was already tagged with "__init" back then -
> most probably the function always got inlined, so we never stumbled over
> it.

It might be good to point out that we need __meminit instead of __init
because microblaze platform does not define CONFIG_ARCH_KEEP_MEMBLOCK,
and __init_memblock fallsback to that.

(I had to go and look as I was puzzled :-) )

Reviewed-by: Oscar Salvador <osalvador@xxxxxxx>

> 
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Fixes: 2f2f371f8907 ("microblaze: Highmem support")
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Michal Simek <monstr@xxxxxxxxx>
> Cc: Mike Rapoport <rppt@xxxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Arvind Sankar <nivedita@xxxxxxxxxxxx>
> Cc: Ira Weiny <ira.weiny@xxxxxxxxx>
> Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> Cc: Oscar Salvador <osalvador@xxxxxxx>
> Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx>
> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
> ---
>  arch/microblaze/mm/init.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/microblaze/mm/init.c b/arch/microblaze/mm/init.c
> index 181e48782e6c..05cf1fb3f5ff 100644
> --- a/arch/microblaze/mm/init.c
> +++ b/arch/microblaze/mm/init.c
> @@ -52,7 +52,7 @@ static void __init highmem_init(void)
>  	pkmap_page_table = virt_to_kpte(PKMAP_BASE);
>  }
>  
> -static void highmem_setup(void)
> +static void __meminit highmem_setup(void)
>  {
>  	unsigned long pfn;
>  
> -- 
> 2.29.2
> 
> 

-- 
Oscar Salvador
SUSE L3