From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e23smtp04.au.ibm.com (e23smtp04.au.ibm.com [202.81.31.146]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id B10B21A020A for ; Tue, 10 Mar 2015 01:08:30 +1100 (AEDT) Received: from /spool/local by e23smtp04.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 10 Mar 2015 00:08:29 +1000 Received: from d23relay09.au.ibm.com (d23relay09.au.ibm.com [9.185.63.181]) by d23dlp01.au.ibm.com (Postfix) with ESMTP id 58DFE2CE8040 for ; Tue, 10 Mar 2015 01:08:26 +1100 (EST) Received: from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138]) by d23relay09.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t29E8Hjb46858484 for ; Tue, 10 Mar 2015 01:08:26 +1100 Received: from d23av02.au.ibm.com (localhost [127.0.0.1]) by d23av02.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t29E7qD7021656 for ; Tue, 10 Mar 2015 01:07:52 +1100 From: Alexey Kardashevskiy To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH v5 03/29] vfio: powerpc/spapr: Check that TCE page size is equal to it_page_size Date: Tue, 10 Mar 2015 01:06:59 +1100 Message-Id: <1425910045-26167-4-git-send-email-aik@ozlabs.ru> In-Reply-To: <1425910045-26167-1-git-send-email-aik@ozlabs.ru> References: <1425910045-26167-1-git-send-email-aik@ozlabs.ru> Cc: kvm@vger.kernel.org, Alexey Kardashevskiy , linux-kernel@vger.kernel.org, Alex Williamson , Paul Mackerras List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , This checks that the TCE table page size is not bigger that the size of a page we just pinned and going to put its physical address to the table. Otherwise the hardware gets unwanted access to physical memory between the end of the actual page and the end of the aligned up TCE page. Since compound_order() and compound_head() work correctly on non-huge pages, there is no need for additional check whether the page is huge. Signed-off-by: Alexey Kardashevskiy --- Changes: v4: * s/tce_check_page_size/tce_page_is_contained/ --- drivers/vfio/vfio_iommu_spapr_tce.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c index 756831f..91e7599 100644 --- a/drivers/vfio/vfio_iommu_spapr_tce.c +++ b/drivers/vfio/vfio_iommu_spapr_tce.c @@ -49,6 +49,22 @@ struct tce_container { bool enabled; }; +static bool tce_page_is_contained(struct page *page, unsigned page_shift) +{ + unsigned shift; + + /* + * Check that the TCE table granularity is not bigger than the size of + * a page we just found. Otherwise the hardware can get access to + * a bigger memory chunk that it should. + */ + shift = PAGE_SHIFT + compound_order(compound_head(page)); + if (shift >= page_shift) + return true; + + return false; +} + static int tce_iommu_enable(struct tce_container *container) { int ret = 0; @@ -197,6 +213,12 @@ static long tce_iommu_build(struct tce_container *container, ret = -EFAULT; break; } + + if (!tce_page_is_contained(page, tbl->it_page_shift)) { + ret = -EPERM; + break; + } + hva = (unsigned long) page_address(page) + (tce & IOMMU_PAGE_MASK(tbl) & ~PAGE_MASK); -- 2.0.0