From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Jan Beulich" <JBeulich@suse.com>
Subject: Re: [V6 PATCH 6.2/7] pvh dom0: Add and remove foreign
 pages
Date: Wed, 11 Dec 2013 09:23:09 +0000
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References: <1386297524-15483-1-git-send-email-mukesh.rathor@oracle.com>
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	<52A7C14C.2020504@linaro.org>
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To: Mukesh Rathor <mukesh.rathor@oracle.com>
Cc: Xen-devel@lists.xensource.com, Ian Campbell <Ian.Campbell@citrix.com>, george.dunlap@eu.citrix.com, Julien Grall <julien.grall@linaro.org>, tim@xen.org, keir.xen@gmail.com
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>>> On 11.12.13 at 02:47, Mukesh Rathor <mukesh.rathor@oracle.com> wrote:
> On Wed, 11 Dec 2013 01:35:08 +0000
> Julien Grall <julien.grall@linaro.org> wrote:
> 
>> >       unsigned long mfn = gmfn_to_mfn(d, gfn);
>> >
>> > -    ASSERT(t == NULL);
>> > +    ASSERT(*t == INT_MAX);
>> 
>> There is various place where get_page_from_gfn where t == NULL. With 
>> this solution it will segfault every time.
>> 
>> I would do something like that:
>>    if (*t)
>>      t = INT_MAX;
>...
> @@ -83,7 +83,8 @@ static inline struct page_info *get_page_from_gfn(
>      struct page_info *page;
>      unsigned long mfn = gmfn_to_mfn(d, gfn);
>  
> -    ASSERT(t == NULL);
> +    if ( t )
> +        ASSERT(*t == INT_MAX);

If you already don't follow Julien's suggestion, then please

    ASSERT(!t || *t == INT_MAX);

Jan