[PATCH 1/2] arm64/mm: Use generic __pud_free() helper in pud_free() implementation

[Ryan Roberts]

On 01/03/2024 10:40, Ard Biesheuvel wrote:
> From: Ard Biesheuvel <ardb at kernel.org>
> 
> Commit 0dd4f60a2c76 ("arm64: mm: Add support for folding PUDs at
> runtime") implements specialized PUD alloc/free helpers to allow the
> decision whether or not to fold PUDs to be made at runtime when the
> number of paging levels is 4 or higher.
> 
> Its implementation of pud_free() is based on the generic version that
> existed when the patch was first written, but in the meantime, the
> freeing of a PUD has become a bit more involved, and so instead of
> simply freeing the page, we should invoke the generic __pud_free() that
> encapsulates whatever needs doing at this point.
> 
> This fixes a reported warning emitted by the page flags
> self-diagnostics.
> 
> Reported-by: Ryan Roberts <ryan.roberts at arm.com>
> Signed-off-by: Ard Biesheuvel <ardb at kernel.org>

Tested-by: Ryan Roberts <ryan.roberts at arm.com>

> ---
>  arch/arm64/include/asm/pgalloc.h | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/pgalloc.h b/arch/arm64/include/asm/pgalloc.h
> index aeba2cf15a25..8ff5f2a2579e 100644
> --- a/arch/arm64/include/asm/pgalloc.h
> +++ b/arch/arm64/include/asm/pgalloc.h
> @@ -60,8 +60,7 @@ static inline void pud_free(struct mm_struct *mm, pud_t *pud)
>  {
>  	if (!pgtable_l4_enabled())
>  		return;
> -	BUG_ON((unsigned long)pud & (PAGE_SIZE-1));
> -	free_page((unsigned long)pud);
> +	__pud_free(mm, pud);
>  }
>  #else
>  static inline void __p4d_populate(p4d_t *p4dp, phys_addr_t pudp, p4dval_t prot)