linux-kernel - Re: [PATCH] xen: correct size of level2_kernel

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Date:	Fri, 29 Oct 2010 09:18:51 -0700
From:	Jeremy Fitzhardinge <jeremy@...p.org>
To:	Ian Campbell <ian.campbell@...rix.com>
CC:	xen-devel@...ts.xensource.com, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] xen: correct size of level2_kernel_pgt

 On 10/29/2010 08:56 AM, Ian Campbell wrote:
> sizeof(pmd_t *) is 4 bytes on PAE leading to an allocation of only
> 2048 bytes. The correct size is sizeof(pmd_t) giving us a full page
> allocation.

Oooooh.  Nasty.

    J
> Signed-off-by: Ian Campbell <ian.campbell@...rix.com>
> Cc: Jeremy Fitzhardinge <jeremy@...p.org>
> ---
>
> Applies to mainline since 2.6.36 and to xen.git 2.6.32 based trees
>
>  arch/x86/xen/mmu.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
> index c237b81..21ed8d7 100644
> --- a/arch/x86/xen/mmu.c
> +++ b/arch/x86/xen/mmu.c
> @@ -2126,7 +2126,7 @@ __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd,
>  {
>  	pmd_t *kernel_pmd;
>  
> -	level2_kernel_pgt = extend_brk(sizeof(pmd_t *) * PTRS_PER_PMD, PAGE_SIZE);
> +	level2_kernel_pgt = extend_brk(sizeof(pmd_t) * PTRS_PER_PMD, PAGE_SIZE);
>  
>  	max_pfn_mapped = PFN_DOWN(__pa(xen_start_info->pt_base) +
>  				  xen_start_info->nr_pt_frames * PAGE_SIZE +

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