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=-8.8 required=3.0 tests=DATE_IN_FUTURE_06_12, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 4774FC28D16 for ; Mon, 10 Jun 2019 12:52:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2B039207E0 for ; Mon, 10 Jun 2019 12:52:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390059AbfFJMwI (ORCPT ); Mon, 10 Jun 2019 08:52:08 -0400 Received: from ex13-edg-ou-001.vmware.com ([208.91.0.189]:26243 "EHLO EX13-EDG-OU-001.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388373AbfFJMwH (ORCPT ); Mon, 10 Jun 2019 08:52:07 -0400 Received: from sc9-mailhost3.vmware.com (10.113.161.73) by EX13-EDG-OU-001.vmware.com (10.113.208.155) with Microsoft SMTP Server id 15.0.1156.6; Mon, 10 Jun 2019 05:51:59 -0700 Received: from akaher-lnx-dev.eng.vmware.com (unknown [10.110.19.203]) by sc9-mailhost3.vmware.com (Postfix) with ESMTP id 6C6AE40E0B; Mon, 10 Jun 2019 05:52:01 -0700 (PDT) From: Ajay Kaher To: , , , , , , CC: , , , , , , , , , , , Subject: [PATCH] [v4.14.y] infiniband: fix race condition between infiniband mlx4, mlx5 driver and core dumping Date: Tue, 11 Jun 2019 02:22:17 +0530 Message-ID: <1560199937-23476-1-git-send-email-akaher@vmware.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 Content-Type: text/plain Received-SPF: None (EX13-EDG-OU-001.vmware.com: akaher@vmware.com does not designate permitted sender hosts) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch is the extension of following upstream commit to fix the race condition between get_task_mm() and core dumping for IB->mlx4 and IB->mlx5 drivers: commit 04f5866e41fb ("coredump: fix race condition between mmget_not_zero()/get_task_mm() and core dumping")' Thanks to Jason for pointing this. Signed-off-by: Ajay Kaher --- drivers/infiniband/hw/mlx4/main.c | 4 +++- drivers/infiniband/hw/mlx5/main.c | 3 +++ 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/infiniband/hw/mlx4/main.c b/drivers/infiniband/hw/mlx4/main.c index e2beb18..0299c06 100644 --- a/drivers/infiniband/hw/mlx4/main.c +++ b/drivers/infiniband/hw/mlx4/main.c @@ -1197,6 +1197,8 @@ static void mlx4_ib_disassociate_ucontext(struct ib_ucontext *ibcontext) * mlx4_ib_vma_close(). */ down_write(&owning_mm->mmap_sem); + if (!mmget_still_valid(owning_mm)) + goto skip_mm; for (i = 0; i < HW_BAR_COUNT; i++) { vma = context->hw_bar_info[i].vma; if (!vma) @@ -1215,7 +1217,7 @@ static void mlx4_ib_disassociate_ucontext(struct ib_ucontext *ibcontext) /* context going to be destroyed, should not access ops any more */ context->hw_bar_info[i].vma->vm_ops = NULL; } - +skip_mm: up_write(&owning_mm->mmap_sem); mmput(owning_mm); put_task_struct(owning_process); diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c index 13a9206..3fbe396 100644 --- a/drivers/infiniband/hw/mlx5/main.c +++ b/drivers/infiniband/hw/mlx5/main.c @@ -1646,6 +1646,8 @@ static void mlx5_ib_disassociate_ucontext(struct ib_ucontext *ibcontext) * mlx5_ib_vma_close. */ down_write(&owning_mm->mmap_sem); + if (!mmget_still_valid(owning_mm)) + goto skip_mm; mutex_lock(&context->vma_private_list_mutex); list_for_each_entry_safe(vma_private, n, &context->vma_private_list, list) { @@ -1662,6 +1664,7 @@ static void mlx5_ib_disassociate_ucontext(struct ib_ucontext *ibcontext) kfree(vma_private); } mutex_unlock(&context->vma_private_list_mutex); +skip_mm: up_write(&owning_mm->mmap_sem); mmput(owning_mm); put_task_struct(owning_process); -- 2.7.4