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=-18.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 E3B92C49EAB for ; Mon, 14 Jun 2021 11:39:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CEE6E61105 for ; Mon, 14 Jun 2021 11:39:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237030AbhFNLk3 (ORCPT ); Mon, 14 Jun 2021 07:40:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:52108 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235331AbhFNL0J (ORCPT ); Mon, 14 Jun 2021 07:26:09 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9FC4C619A8; Mon, 14 Jun 2021 10:54:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1623668078; bh=Rg7F1m83b52OiaoNHjBlrgjdIHijKWG8aoBQUVF00Dw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=puOP3IqI9iP+CDqUgY+AGJzbXB3Mh2GkoDl/8G4nH8g4Z9l3RSda98XbGWmHkRlOs 20OOENm1HwEo9IYLeE8JFEGS95iR23H/yk67Ll6ezDhtwpVLgMUHwvUF1YXhcHkeBw UV0199eHAWTbugF/KZAqsgV024H0LVMkGqDm9u8I= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jason Gunthorpe , Mark Zhang , Leon Romanovsky Subject: [PATCH 5.12 138/173] RDMA/mlx5: Use different doorbell memory for different processes Date: Mon, 14 Jun 2021 12:27:50 +0200 Message-Id: <20210614102702.754312557@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210614102658.137943264@linuxfoundation.org> References: <20210614102658.137943264@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mark Zhang commit a0ffb4c12f7fa89163e228e6f27df09b46631db1 upstream. In a fork scenario, the parent and child can have same virtual address and also share the uverbs fd. That causes to the list_for_each_entry search return same doorbell physical page for all processes, even though that page has been COW' or copied. This patch takes the mm_struct into consideration during search, to make sure that VA's belonging to different processes are not intermixed. Resolves the malfunction of uverbs after fork in some specific cases. Fixes: e126ba97dba9 ("mlx5: Add driver for Mellanox Connect-IB adapters") Link: https://lore.kernel.org/r/feacc23fe0bc6e1088c6824d5583798745e72405.1622726212.git.leonro@nvidia.com Reviewed-by: Jason Gunthorpe Signed-off-by: Mark Zhang Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe Signed-off-by: Greg Kroah-Hartman --- drivers/infiniband/hw/mlx5/doorbell.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/drivers/infiniband/hw/mlx5/doorbell.c +++ b/drivers/infiniband/hw/mlx5/doorbell.c @@ -41,6 +41,7 @@ struct mlx5_ib_user_db_page { struct ib_umem *umem; unsigned long user_virt; int refcnt; + struct mm_struct *mm; }; int mlx5_ib_db_map_user(struct mlx5_ib_ucontext *context, @@ -53,7 +54,8 @@ int mlx5_ib_db_map_user(struct mlx5_ib_u mutex_lock(&context->db_page_mutex); list_for_each_entry(page, &context->db_page_list, list) - if (page->user_virt == (virt & PAGE_MASK)) + if ((current->mm == page->mm) && + (page->user_virt == (virt & PAGE_MASK))) goto found; page = kmalloc(sizeof(*page), GFP_KERNEL); @@ -71,6 +73,8 @@ int mlx5_ib_db_map_user(struct mlx5_ib_u kfree(page); goto out; } + mmgrab(current->mm); + page->mm = current->mm; list_add(&page->list, &context->db_page_list); @@ -91,6 +95,7 @@ void mlx5_ib_db_unmap_user(struct mlx5_i if (!--db->u.user_page->refcnt) { list_del(&db->u.user_page->list); + mmdrop(db->u.user_page->mm); ib_umem_release(db->u.user_page->umem); kfree(db->u.user_page); }