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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E6BF9C433EF for ; Tue, 14 Jun 2022 02:20:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353341AbiFNCUK (ORCPT ); Mon, 13 Jun 2022 22:20:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57640 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1353740AbiFNCOD (ORCPT ); Mon, 13 Jun 2022 22:14:03 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 91E6C344C5; Mon, 13 Jun 2022 19:08:10 -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 58B26B816A4; Tue, 14 Jun 2022 02:07:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DCE74C3411B; Tue, 14 Jun 2022 02:07:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1655172438; bh=0G8hn+LDRdvLcmIuBLbKikNM+6KmtRGefFtgmQdTpPE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PhC/+/kJ/23UsEteE2On2ABpjwLxEdOZsHcu6xArZoDHBVnnGHQnx4gVmGXw3u5E7 4SS+qy/ePF5Hh5QGzILZhJibHPpIrcWqniZmHdM3W9dBt7Xu/WTBridCNa/TXk7eMI d8cK4dZroCt91Ug6q/KdVb7uJrihN6JqhkjbiTahVdwVWjKpSvtO52ki8G3ta79jzf vaYVovmmpxoRtHwNOOb15ZbK8NeotVjj6sZW/cWNCpODZ2VqtdWT6ooQBnQW5L0Bs6 hZx7wmmYxVYeyWsZldvdYrPsgZ55mhTzK8wk5ePwn/7Z+rZAoObyeULAOEi1+eGimR CN8mSRObv8NmQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Philip Yang , Felix Kuehling , Alex Deucher , Sasha Levin , oded.gabbay@gmail.com, christian.koenig@amd.com, airlied@linux.ie, dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 5.15 05/41] drm/amdkfd: Use mmget_not_zero in MMU notifier Date: Mon, 13 Jun 2022 22:06:30 -0400 Message-Id: <20220614020707.1099487-5-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220614020707.1099487-1-sashal@kernel.org> References: <20220614020707.1099487-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Philip Yang [ Upstream commit fa582c6f3684ac0098a9d02ddf0ed52a02b37127 ] MMU notifier callback may pass in mm with mm->mm_users==0 when process is exiting, use mmget_no_zero to avoid accessing invalid mm in deferred list work after mm is gone. Signed-off-by: Philip Yang Reviewed-by: Felix Kuehling Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c index 830809b694dd..74e6f613be02 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c @@ -2181,6 +2181,8 @@ svm_range_cpu_invalidate_pagetables(struct mmu_interval_notifier *mni, if (range->event == MMU_NOTIFY_RELEASE) return true; + if (!mmget_not_zero(mni->mm)) + return true; start = mni->interval_tree.start; last = mni->interval_tree.last; @@ -2207,6 +2209,7 @@ svm_range_cpu_invalidate_pagetables(struct mmu_interval_notifier *mni, } svm_range_unlock(prange); + mmput(mni->mm); return true; } -- 2.35.1