Re: [PATCH] kmemleak: Ignore the aperture memory hole on x86_64

[Ingo Molnar <mingo@elte.hu>]

* Catalin Marinas <catalin.marinas@arm.com> wrote:

> This block is allocated with alloc_bootmem() and scanned by kmemleak but
> the kernel direct mapping may no longer exist. This patch tells kmemleak
> to ignore this memory hole.
> 
> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Ingo Molnar <mingo@elte.hu>
> ---
>  arch/x86/kernel/aperture_64.c |    5 +++++
>  1 files changed, 5 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/x86/kernel/aperture_64.c b/arch/x86/kernel/aperture_64.c
> index 676debf..cb690b3 100644
> --- a/arch/x86/kernel/aperture_64.c
> +++ b/arch/x86/kernel/aperture_64.c
> @@ -94,6 +94,11 @@ static u32 __init allocate_aperture(void)
>  	 * code for safe
>  	 */
>  	p = __alloc_bootmem_nopanic(aper_size, aper_size, 512ULL<<20);
> +	/*
> +	 * Kmemleak should not scan this block as it may not be mapped via the
> +	 * kernel direct mapping.
> +	 */
> +	kmemleak_ignore(p);

i tried this in -tip, it causes this build error:

arch/x86/kernel/aperture_64.c: In function ‘allocate_aperture’:
arch/x86/kernel/aperture_64.c:101: error: implicit declaration of function ‘kmemleak_ignore’

	Ingo