From patchwork Tue Aug 23 10:51:02 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leon Romanovsky X-Patchwork-Id: 12952140 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1FD66C32772 for ; Tue, 23 Aug 2022 15:22:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241971AbiHWPWo (ORCPT ); Tue, 23 Aug 2022 11:22:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49240 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242234AbiHWPW0 (ORCPT ); Tue, 23 Aug 2022 11:22:26 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0E44011C3CE for ; Tue, 23 Aug 2022 03:52:06 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0309261527 for ; Tue, 23 Aug 2022 10:51:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DAF04C433D6; Tue, 23 Aug 2022 10:51:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1661251868; bh=hxxUOpB4NbSFuSV90hycsk0bdHxB3CKP7udhzCtaWnM=; h=From:To:Cc:Subject:Date:From; b=PwmKv4+nNzCCP2lbznjYLp/+ItW7Az3vTvzYReFISncHVmFtfVeYgtrLiQcpt4omL 9+z2YuPvbZssi3yc63kfU5jozx8G8szRDKD+9Oa9krPATA1Py6Q/KnHilHOo6O7X3W xs4UhjR4TbwLk2g5dt5gmelxphcnrNMVnDER3wZjzz739l6LaOwquf2PposqnjKJwP zbOw4erDyBwr9fQ5ntfnU4qAXiMxJT6PT4rA56aRHToBg/iAvAP+DQjXbguwtH9sWb 5pe3qVI/O60ipi9Ayw5cWLAWjpJGmMCP21jqsP7ztk4Tje+0s5vmaiNXeti4aesCxZ GbcGLzuCpl9NA== From: Leon Romanovsky To: Jason Gunthorpe Cc: Yishai Hadas , linux-rdma@vger.kernel.org, Maor Gottlieb Subject: [PATCH rdma-rc] IB/core: Fix a nested dead lock as part of ODP flow Date: Tue, 23 Aug 2022 13:51:02 +0300 Message-Id: <74d93541ea533ef7daec6f126deb1072500aeb16.1661251841.git.leonro@nvidia.com> X-Mailer: git-send-email 2.37.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org From: Yishai Hadas Fix a nested dead lock as part of ODP flow by using mmput_async(). From the below call trace [1] can see that calling mmput() once we have the umem_odp->umem_mutex locked as required by ib_umem_odp_map_dma_and_lock() might trigger in the same task the exit_mmap()->__mmu_notifier_release()->mlx5_ib_invalidate_range() which may dead lock when trying to lock the same mutex. Moving to use mmput_async() will solve the problem as the above exit_mmap() flow will be called in other task and will be executed once the lock will be available. [1] [64843.077665] task:kworker/u133:2 state:D stack: 0 pid:80906 ppid: 2 flags:0x00004000 [64843.077672] Workqueue: mlx5_ib_page_fault mlx5_ib_eqe_pf_action [mlx5_ib] [64843.077719] Call Trace: [64843.077722] [64843.077724] __schedule+0x23d/0x590 [64843.077729] schedule+0x4e/0xb0 [64843.077735] schedule_preempt_disabled+0xe/0x10 [64843.077740] __mutex_lock.constprop.0+0x263/0x490 [64843.077747] __mutex_lock_slowpath+0x13/0x20 [64843.077752] mutex_lock+0x34/0x40 [64843.077758] mlx5_ib_invalidate_range+0x48/0x270 [mlx5_ib] [64843.077808] __mmu_notifier_release+0x1a4/0x200 [64843.077816] exit_mmap+0x1bc/0x200 [64843.077822] ? walk_page_range+0x9c/0x120 [64843.077828] ? __cond_resched+0x1a/0x50 [64843.077833] ? mutex_lock+0x13/0x40 [64843.077839] ? uprobe_clear_state+0xac/0x120 [64843.077860] mmput+0x5f/0x140 [64843.077867] ib_umem_odp_map_dma_and_lock+0x21b/0x580 [ib_core] [64843.077931] pagefault_real_mr+0x9a/0x140 [mlx5_ib] [64843.077962] pagefault_mr+0xb4/0x550 [mlx5_ib] [64843.077992] pagefault_single_data_segment.constprop.0+0x2ac/0x560 [mlx5_ib] [64843.078022] mlx5_ib_eqe_pf_action+0x528/0x780 [mlx5_ib] [64843.078051] process_one_work+0x22b/0x3d0 [64843.078059] worker_thread+0x53/0x410 [64843.078065] ? process_one_work+0x3d0/0x3d0 [64843.078073] kthread+0x12a/0x150 [64843.078079] ? set_kthread_struct+0x50/0x50 [64843.078085] ret_from_fork+0x22/0x30 [64843.078093] Fixes: 36f30e486dce ("IB/core: Improve ODP to use hmm_range_fault()") Reviewed-by: Maor Gottlieb Signed-off-by: Yishai Hadas Signed-off-by: Leon Romanovsky --- drivers/infiniband/core/umem_odp.c | 2 +- kernel/fork.c | 1 + 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/infiniband/core/umem_odp.c b/drivers/infiniband/core/umem_odp.c index 186ed8859920..d39e16c211e8 100644 --- a/drivers/infiniband/core/umem_odp.c +++ b/drivers/infiniband/core/umem_odp.c @@ -462,7 +462,7 @@ int ib_umem_odp_map_dma_and_lock(struct ib_umem_odp *umem_odp, u64 user_virt, mutex_unlock(&umem_odp->umem_mutex); out_put_mm: - mmput(owning_mm); + mmput_async(owning_mm); out_put_task: if (owning_process) put_task_struct(owning_process); diff --git a/kernel/fork.c b/kernel/fork.c index 90c85b17bf69..8a9e92068b15 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1225,6 +1225,7 @@ void mmput_async(struct mm_struct *mm) schedule_work(&mm->async_put_work); } } +EXPORT_SYMBOL_GPL(mmput_async); #endif /**