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Message-ID: <9005c77f-c929-21f7-a735-3ab4e6d89832@suse.cz>
Date:   Thu, 12 Jan 2023 11:38:44 +0100
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Subject: Re: [PATCH v3 3/5] m68k/mm/motorola: specify pmd_page() type
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To:     Lorenzo Stoakes <lstoakes@gmail.com>, linux-mm@kvack.org,
        Andrew Morton <akpm@linux-foundation.org>,
        linux-kernel@vger.kernel.org
Cc:     Matthew Wilcox <willy@infradead.org>,
        Hugh Dickins <hughd@google.com>,
        Liam Howlett <liam.howlett@oracle.com>,
        William Kucharski <william.kucharski@oracle.com>,
        Christian Brauner <brauner@kernel.org>,
        Jonathan Corbet <corbet@lwn.net>,
        Mike Rapoport <rppt@kernel.org>,
        Joel Fernandes <joel@joelfernandes.org>,
        Geert Uytterhoeven <geert@linux-m68k.org>
References: <cover.1672043615.git.lstoakes@gmail.com>
 <4b59f47ff4cd89ff76a5b6edbef6e8e0b37046f1.1672043615.git.lstoakes@gmail.com>
From:   Vlastimil Babka <vbabka@suse.cz>
In-Reply-To: <4b59f47ff4cd89ff76a5b6edbef6e8e0b37046f1.1672043615.git.lstoakes@gmail.com>
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On 12/26/22 09:44, Lorenzo Stoakes wrote:
> Failing to specify a specific type here breaks anything that relies on the type
> being explicitly known, such as page_folio().
> 
> Make explicit the type of null pointer returned here.
> 
> Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>

Acked-by: Vlastimil Babka <vbabka@suse.cz>

> ---
>  arch/m68k/include/asm/motorola_pgtable.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/m68k/include/asm/motorola_pgtable.h b/arch/m68k/include/asm/motorola_pgtable.h
> index 7ac3d64c6b33..562b54e09850 100644
> --- a/arch/m68k/include/asm/motorola_pgtable.h
> +++ b/arch/m68k/include/asm/motorola_pgtable.h
> @@ -124,7 +124,7 @@ static inline void pud_set(pud_t *pudp, pmd_t *pmdp)
>   * expects pmd_page() to exists, only to then DCE it all. Provide a dummy to
>   * make the compiler happy.
>   */
> -#define pmd_page(pmd)		NULL
> +#define pmd_page(pmd)		((struct page *)NULL)
>  
>  
>  #define pud_none(pud)		(!pud_val(pud))