From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ian Campbell Subject: [PATCH 06/21] xen/arm: create_p2m_entries should not call free_domheap_page Date: Fri, 5 Oct 2012 10:38:12 +0000 Message-ID: <1349433507-21148-6-git-send-email-ian.campbell@citrix.com> References: <1349433418.20946.46.camel@zakaz.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1349433418.20946.46.camel@zakaz.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel@lists.xen.org Cc: Stefano Stabellini , tim@xen.org, stefano.stabelini@citrix.com List-Id: xen-devel@lists.xenproject.org From: Stefano Stabellini The guest is entitled to leak a page from its p2m (by overwriting it) if it wants to. Since the memory is effectively lost to it (can't even be recovered by XENMEM increase reservation etc). In these cases we shouldn't call free_domheap_page to free the existing page from create_p2m_entries, because it resets the reference counting but the page is still allocated to the guest (even if not in the p2m anymore) and common grant_table code is also going to call put_page on it. Signed-off-by: Stefano Stabellini Acked-by: Ian Campbell --- xen/arch/arm/p2m.c | 5 ----- 1 files changed, 0 insertions(+), 5 deletions(-) diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c index 7c23b7d..7ae4515 100644 --- a/xen/arch/arm/p2m.c +++ b/xen/arch/arm/p2m.c @@ -189,12 +189,7 @@ static int create_p2m_entries(struct domain *d, /* else: third already valid */ if ( third[third_table_offset(addr)].p2m.valid ) - { - /* p2m entry already present */ - free_domheap_page( - mfn_to_page(third[third_table_offset(addr)].p2m.base)); flush_tlb_all_local(); - } /* Allocate a new RAM page and attach */ switch (op) { -- 1.7.9.1