From nobody Sun Sep 14 22:45:44 2025 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 3C91FC54EE9 for ; Tue, 13 Sep 2022 14:40:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231268AbiIMOkr (ORCPT ); Tue, 13 Sep 2022 10:40:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42924 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234292AbiIMOiI (ORCPT ); Tue, 13 Sep 2022 10:38:08 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 374556BCFA; Tue, 13 Sep 2022 07:20:39 -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 ams.source.kernel.org (Postfix) with ESMTPS id E8086B80FBD; Tue, 13 Sep 2022 14:20:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 47622C433D6; Tue, 13 Sep 2022 14:20:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1663078804; bh=421CXfGyWKaHoPTBniDK3uktGVnaGF0Eg++IBY2VVPk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SE2rqT+IaUT+T6PtiRK7OeZsqwvmfy4Dg8yTk6QnDLKt/rO3f93MWarYlB6YZD8Rh WEGxMxA//CZCvzYEVnMWRiiW8AJbYR4JsqNdm4KDW+49/azBwgl0wT5PsmV+t6nIEW NpAT5bY5OjHxybBuxucf/9VeCBFEq2rq4gJ4IHRM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Maor Gottlieb , Yishai Hadas , Leon Romanovsky , Sasha Levin Subject: [PATCH 5.15 088/121] IB/core: Fix a nested dead lock as part of ODP flow Date: Tue, 13 Sep 2022 16:04:39 +0200 Message-Id: <20220913140401.146920262@linuxfoundation.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220913140357.323297659@linuxfoundation.org> References: <20220913140357.323297659@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Yishai Hadas [ Upstream commit 85eaeb5058f0f04dffb124c97c86b4f18db0b833 ] 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 Link: https://lore.kernel.org/r/74d93541ea533ef7daec6f126deb1072500aeb16.16= 61251841.git.leonro@nvidia.com Signed-off-by: Leon Romanovsky Signed-off-by: Sasha Levin --- 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/u= mem_odp.c index 7a47343d11f9f..b052de1b9ccb9 100644 --- a/drivers/infiniband/core/umem_odp.c +++ b/drivers/infiniband/core/umem_odp.c @@ -463,7 +463,7 @@ int ib_umem_odp_map_dma_and_lock(struct ib_umem_odp *um= em_odp, u64 user_virt, mutex_unlock(&umem_odp->umem_mutex); =20 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 89475c994ca91..908ba3c93893f 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1153,6 +1153,7 @@ void mmput_async(struct mm_struct *mm) schedule_work(&mm->async_put_work); } } +EXPORT_SYMBOL_GPL(mmput_async); #endif =20 /** --=20 2.35.1