[PATCH] x86/MTRR: fix range check in mtrr_add_page()

[PATCH] x86/MTRR: fix range check in mtrr_add_page()

[Jan Beulich]

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Extracted from Yinghai Lu's Linux commit d5c78673 ("x86: Fix /proc/mtrr
with base/size more than 44bits").

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/arch/x86/cpu/mtrr/main.c
+++ b/xen/arch/x86/cpu/mtrr/main.c
@@ -340,7 +340,7 @@ int mtrr_add_page(unsigned long base, un
 		return -EINVAL;
 	}
 
-	if (base & size_or_mask || size & size_or_mask) {
+	if ((base | (base + size - 1)) >> (paddr_bits - PAGE_SHIFT)) {
 		printk(KERN_WARNING "mtrr: base or size exceeds the MTRR width\n");
 		return -EINVAL;
 	}




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x86/MTRR: fix range check in mtrr_add_page()

Extracted from Yinghai Lu's Linux commit d5c78673 ("x86: Fix /proc/mtrr
with base/size more than 44bits").

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/arch/x86/cpu/mtrr/main.c
+++ b/xen/arch/x86/cpu/mtrr/main.c
@@ -340,7 +340,7 @@ int mtrr_add_page(unsigned long base, un
 		return -EINVAL;
 	}
 
-	if (base & size_or_mask || size & size_or_mask) {
+	if ((base | (base + size - 1)) >> (paddr_bits - PAGE_SHIFT)) {
 		printk(KERN_WARNING "mtrr: base or size exceeds the MTRR width\n");
 		return -EINVAL;
 	}

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Re: [PATCH] x86/MTRR: fix range check in mtrr_add_page()

[Andrew Cooper]

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On 13/08/13 16:45, Jan Beulich wrote:
> Extracted from Yinghai Lu's Linux commit d5c78673 ("x86: Fix /proc/mtrr
> with base/size more than 44bits").
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

>
> --- a/xen/arch/x86/cpu/mtrr/main.c
> +++ b/xen/arch/x86/cpu/mtrr/main.c
> @@ -340,7 +340,7 @@ int mtrr_add_page(unsigned long base, un
>  		return -EINVAL;
>  	}
>  
> -	if (base & size_or_mask || size & size_or_mask) {
> +	if ((base | (base + size - 1)) >> (paddr_bits - PAGE_SHIFT)) {
>  		printk(KERN_WARNING "mtrr: base or size exceeds the MTRR width\n");
>  		return -EINVAL;
>  	}
>
>
>
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel


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Re: [PATCH] x86/MTRR: fix range check in mtrr_add_page()

[Keir Fraser]

On 13/08/2013 16:45, "Jan Beulich" <JBeulich@suse.com> wrote:

> Extracted from Yinghai Lu's Linux commit d5c78673 ("x86: Fix /proc/mtrr
> with base/size more than 44bits").
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Acked-by: Keir Fraser <keir@xen.org>

> --- a/xen/arch/x86/cpu/mtrr/main.c
> +++ b/xen/arch/x86/cpu/mtrr/main.c
> @@ -340,7 +340,7 @@ int mtrr_add_page(unsigned long base, un
> return -EINVAL;
> }
>  
> - if (base & size_or_mask || size & size_or_mask) {
> + if ((base | (base + size - 1)) >> (paddr_bits - PAGE_SHIFT)) {
> printk(KERN_WARNING "mtrr: base or size exceeds the MTRR width\n");
> return -EINVAL;
> }
> 
> 
>