From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: Re: [PATCH v3 1/9] mm: Introduce new vm_insert_range API Date: Fri, 7 Dec 2018 09:11:16 -0800 Message-ID: <20181207171116.GA29923@bombadil.infradead.org> References: <20181206183945.GA20932@jordon-HP-15-Notebook-PC> <53bbc095-c9f5-5d6a-6e50-6e060d17eb68@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <53bbc095-c9f5-5d6a-6e50-6e060d17eb68@arm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Robin Murphy Cc: mhocko@suse.com, heiko@sntech.de, peterz@infradead.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux1394-devel@lists.sourceforge.net, m.szyprowski@samsung.com, sfr@canb.auug.org.au, oleksandr_andrushchenko@epam.com, joro@8bytes.org, linux@armlinux.org.uk, iommu@lists.linux-foundation.org, airlied@linux.ie, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, treding@nvidia.com, linux-media@vger.kernel.org, keescook@chromium.org, pawel@osciak.com, riel@surriel.com, rppt@linux.vnet.ibm.com, boris.ostrovsky@oracle.com, mchehab@kernel.org, iamjoonsoo.kim@lge.com, vbabka@suse.cz, jgross@suse.com, hjc@rock-chips.com, xen-devel@lists.xen.org, kyungmin.park@samsung.com, stefanr@s5r6.in-berlin.de, Souptick Joarder , akpm@linux-foundation.org, kirill.shutemov@linux.intel.com List-Id: linux-rockchip.vger.kernel.org On Fri, Dec 07, 2018 at 03:34:56PM +0000, Robin Murphy wrote: > > +int vm_insert_range(struct vm_area_struct *vma, unsigned long addr, > > + struct page **pages, unsigned long page_count) > > +{ > > + unsigned long uaddr = addr; > > + int ret = 0, i; > > Some of the sites being replaced were effectively ensuring that vma and > pages were mutually compatible as an initial condition - would it be worth > adding something here for robustness, e.g.: > > + if (page_count != vma_pages(vma)) > + return -ENXIO; I think we want to allow this to be used to populate part of a VMA. So perhaps: if (page_count > vma_pages(vma)) return -ENXIO;