Re: [PATCH v1 3/9] powerpc/vdso: don't clear PG_reserved

[Michael Ellerman]

David Hildenbrand <david@xxxxxxxxxx> writes:

> The VDSO is part of the kernel image and therefore the struct pages are
> marked as reserved during boot.
>
> As we install a special mapping, the actual struct pages will never be
> exposed to MM via the page tables. We can therefore leave the pages
> marked as reserved.
>
> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
> Cc: Paul Mackerras <paulus@xxxxxxxxx>
> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> Cc: Christophe Leroy <christophe.leroy@xxxxxx>
> Cc: Kees Cook <keescook@xxxxxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Michal Hocko <mhocko@xxxxxxxxxx>
> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
> ---
>  arch/powerpc/kernel/vdso.c | 2 --
>  1 file changed, 2 deletions(-)

Thanks.

Acked-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> (powerpc)

cheers

> diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
> index 65b3bdb99f0b..d59dc2e9a695 100644
> --- a/arch/powerpc/kernel/vdso.c
> +++ b/arch/powerpc/kernel/vdso.c
> @@ -795,7 +795,6 @@ static int __init vdso_init(void)
>  	BUG_ON(vdso32_pagelist == NULL);
>  	for (i = 0; i < vdso32_pages; i++) {
>  		struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
> -		ClearPageReserved(pg);
>  		get_page(pg);
>  		vdso32_pagelist[i] = pg;
>  	}
> @@ -809,7 +808,6 @@ static int __init vdso_init(void)
>  	BUG_ON(vdso64_pagelist == NULL);
>  	for (i = 0; i < vdso64_pages; i++) {
>  		struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
> -		ClearPageReserved(pg);
>  		get_page(pg);
>  		vdso64_pagelist[i] = pg;
>  	}
> -- 
> 2.17.2