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From: Wei Liu <wei.liu@kernel•org>
To: Michael Kelley <mikelley@microsoft•com>
Cc: hpa@zytor•com, kys@microsoft•com, haiyangz@microsoft•com,
	wei.liu@kernel•org, decui@microsoft•com, luto@kernel•org,
	peterz@infradead•org, davem@davemloft•net, edumazet@google•com,
	kuba@kernel•org, pabeni@redhat•com, lpieralisi@kernel•org,
	robh@kernel•org, kw@linux•com, bhelgaas@google•com,
	arnd@arndb•de, hch@infradead•org, m.szyprowski@samsung•com,
	robin.murphy@arm•com, thomas.lendacky@amd•com,
	brijesh.singh@amd•com, tglx@linutronix•de, mingo@redhat•com,
	bp@alien8•de, dave.hansen@linux•intel.com,
	Tianyu.Lan@microsoft•com, kirill.shutemov@linux•intel.com,
	sathyanarayanan.kuppuswamy@linux•intel.com, ak@linux•intel.com,
	isaku.yamahata@intel•com, dan.j.williams@intel•com,
	jane.chu@oracle•com, seanjc@google•com, tony.luck@intel•com,
	x86@kernel•org, linux-kernel@vger•kernel.org,
	linux-hyperv@vger•kernel.org, netdev@vger•kernel.org,
	linux-pci@vger•kernel.org, linux-arch@vger•kernel.org,
	iommu@lists•linux.dev
Subject: Re: [PATCH v4 1/1] x86/ioremap: Fix page aligned size calculation in __ioremap_caller()
Date: Fri, 25 Nov 2022 15:19:36 +0000	[thread overview]
Message-ID: <Y4DdCD7555d2SpkZ@liuwe-devbox-debian-v2> (raw)
In-Reply-To: <1669138842-30100-1-git-send-email-mikelley@microsoft.com>

On Tue, Nov 22, 2022 at 09:40:42AM -0800, Michael Kelley wrote:
> Current code re-calculates the size after aligning the starting and
> ending physical addresses on a page boundary. But the re-calculation
> also embeds the masking of high order bits that exceed the size of
> the physical address space (via PHYSICAL_PAGE_MASK). If the masking
> removes any high order bits, the size calculation results in a huge
> value that is likely to immediately fail.
> 
> Fix this by re-calculating the page-aligned size first. Then mask any
> high order bits using PHYSICAL_PAGE_MASK.
> 
> Fixes: ffa71f33a820 ("x86, ioremap: Fix incorrect physical address handling in PAE mode")
> Acked-by: Dave Hansen <dave.hansen@linux•intel.com>
> Signed-off-by: Michael Kelley <mikelley@microsoft•com>

Reviewed-by: Wei Liu <wei.liu@kernel•org>

> ---
> 
> This patch was previously Patch 1 of a larger series[1].  Breaking
> it out separately per discussion with Dave Hansen and Boris Petkov.
> 
> [1] https://lore.kernel.org/linux-hyperv/1668624097-14884-1-git-send-email-mikelley@microsoft.com/
> 
>  arch/x86/mm/ioremap.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
> index 78c5bc6..6453fba 100644
> --- a/arch/x86/mm/ioremap.c
> +++ b/arch/x86/mm/ioremap.c
> @@ -217,9 +217,15 @@ static void __ioremap_check_mem(resource_size_t addr, unsigned long size,
>  	 * Mappings have to be page-aligned
>  	 */
>  	offset = phys_addr & ~PAGE_MASK;
> -	phys_addr &= PHYSICAL_PAGE_MASK;
> +	phys_addr &= PAGE_MASK;
>  	size = PAGE_ALIGN(last_addr+1) - phys_addr;
>  
> +	/*
> +	 * Mask out any bits not part of the actual physical
> +	 * address, like memory encryption bits.
> +	 */
> +	phys_addr &= PHYSICAL_PAGE_MASK;
> +
>  	retval = memtype_reserve(phys_addr, (u64)phys_addr + size,
>  						pcm, &new_pcm);
>  	if (retval) {
> -- 
> 1.8.3.1
> 

  reply	other threads:[~2022-11-25 15:19 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-22 17:40 [PATCH v4 1/1] x86/ioremap: Fix page aligned size calculation in __ioremap_caller() Michael Kelley
2022-11-25 15:19 ` Wei Liu [this message]
2022-11-28 14:43   ` Michael Kelley (LINUX)
2022-11-28 15:45     ` Borislav Petkov
2022-11-28 16:04       ` Michael Kelley (LINUX)

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