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From: George Dunlap <george.dunlap@citrix.com>
To: Wei Liu <wei.liu2@citrix.com>,
	Xen-devel <xen-devel@lists.xenproject.org>
Cc: George Dunlap <george.dunlap@eu.citrix.com>,
	Ian Jackson <ian.jackson@eu.citrix.com>,
	Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Subject: Re: [PATCH] xentrace: simplify map_page function in xenctx
Date: Thu, 17 Mar 2016 11:48:39 +0000	[thread overview]
Message-ID: <56EA9997.6000109@citrix.com> (raw)
In-Reply-To: <1457010607-8223-1-git-send-email-wei.liu2@citrix.com>

On 03/03/16 13:10, Wei Liu wrote:
> There were several problems:
> 
> 1. Variable mapped was set to NULL so the following two "if"s were
>    useless.
> 2. Variable previous_mfn was set but never used.

mapped and previous_mfn are static, which (in this context) means they
persists across invocations of the function. mapped is only set to NULL
for the first call. Subsequent calls it's used to unmap the previous
mapping; and previous_mfn is used to avoid unmap'ing and re-map'ing the
same mfn.

This change will cause xenctx to leak virtual address space.

 -George


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  reply	other threads:[~2016-03-17 11:49 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-03-03 13:10 Wei Liu
2016-03-17 11:48 ` George Dunlap [this message]
2016-03-17 11:54   ` Wei Liu

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