From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1BAB9C43219 for ; Fri, 3 May 2019 17:03:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E831F206C3 for ; Fri, 3 May 2019 17:03:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728749AbfECRDV (ORCPT ); Fri, 3 May 2019 13:03:21 -0400 Received: from foss.arm.com ([217.140.101.70]:37368 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726720AbfECRDU (ORCPT ); Fri, 3 May 2019 13:03:20 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B389915A2; Fri, 3 May 2019 10:03:19 -0700 (PDT) Received: from arrakis.emea.arm.com (arrakis.cambridge.arm.com [10.1.196.78]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2A5D43F557; Fri, 3 May 2019 10:03:13 -0700 (PDT) Date: Fri, 3 May 2019 18:03:10 +0100 From: Catalin Marinas To: Andrey Konovalov Cc: linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org, linux-media@vger.kernel.org, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org, Vincenzo Frascino , Will Deacon , Mark Rutland , Andrew Morton , Greg Kroah-Hartman , Kees Cook , Yishai Hadas , Kuehling@google.com, Felix , Deucher@google.com, Alexander , Koenig@google.com, Christian , Mauro Carvalho Chehab , Jens Wiklander , Alex Williamson , Leon Romanovsky , Dmitry Vyukov , Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Robin Murphy , Chintan Pandya , Luc Van Oostenryck , Dave Martin , Kevin Brodsky , Szabolcs Nagy , Leon Romanovsky Subject: Re: [PATCH v14 13/17] IB/mlx4, arm64: untag user pointers in mlx4_get_umem_mr Message-ID: <20190503170310.GL55449@arrakis.emea.arm.com> References: <05c0c078b8b5984af4cc3b105a58c711dcd83342.1556630205.git.andreyknvl@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <05c0c078b8b5984af4cc3b105a58c711dcd83342.1556630205.git.andreyknvl@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 30, 2019 at 03:25:09PM +0200, Andrey Konovalov wrote: > This patch is a part of a series that extends arm64 kernel ABI to allow to > pass tagged user pointers (with the top byte set to something else other > than 0x00) as syscall arguments. > > mlx4_get_umem_mr() uses provided user pointers for vma lookups, which can > only by done with untagged pointers. > > Untag user pointers in this function. > > Signed-off-by: Andrey Konovalov > Reviewed-by: Leon Romanovsky > --- > drivers/infiniband/hw/mlx4/mr.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/infiniband/hw/mlx4/mr.c b/drivers/infiniband/hw/mlx4/mr.c > index 395379a480cb..9a35ed2c6a6f 100644 > --- a/drivers/infiniband/hw/mlx4/mr.c > +++ b/drivers/infiniband/hw/mlx4/mr.c > @@ -378,6 +378,7 @@ static struct ib_umem *mlx4_get_umem_mr(struct ib_udata *udata, u64 start, > * again > */ > if (!ib_access_writable(access_flags)) { > + unsigned long untagged_start = untagged_addr(start); > struct vm_area_struct *vma; > > down_read(¤t->mm->mmap_sem); > @@ -386,9 +387,9 @@ static struct ib_umem *mlx4_get_umem_mr(struct ib_udata *udata, u64 start, > * cover the memory, but for now it requires a single vma to > * entirely cover the MR to support RO mappings. > */ > - vma = find_vma(current->mm, start); > - if (vma && vma->vm_end >= start + length && > - vma->vm_start <= start) { > + vma = find_vma(current->mm, untagged_start); > + if (vma && vma->vm_end >= untagged_start + length && > + vma->vm_start <= untagged_start) { > if (vma->vm_flags & VM_WRITE) > access_flags |= IB_ACCESS_LOCAL_WRITE; > } else { Discussion ongoing on the previous version of the patch but I'm more inclined to do this in ib_uverbs_(re)reg_mr() on cmd.start. -- Catalin