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 EEB7FC43334 for ; Mon, 20 Jun 2022 12:53:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241786AbiFTMxL (ORCPT ); Mon, 20 Jun 2022 08:53:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36510 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241511AbiFTMxI (ORCPT ); Mon, 20 Jun 2022 08:53:08 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4598CD11B; Mon, 20 Jun 2022 05:53:07 -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 0BB59B811A6; Mon, 20 Jun 2022 12:53:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 685A8C3411B; Mon, 20 Jun 2022 12:53:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1655729584; bh=osKyJ1+KTbP33abJvrFOEn7PkpMGgyBTQRpahpLYjcc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PpBlVjuv5IZdpi9pVyLov2O70llMCEYFl6auDUe8o+pKCTrAjYxwJZZDqLD71JxZK WvyP45Q2cjnSro5sOE/PDM5+EIt0NLskwflppN9enz06cb7XCxP8iNTSTn2iMTbAIk EKMlUjmmCF/dAUqEOrODQc9HsGOtHSxq8WxyBmIc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Philip Yang , Felix Kuehling , Alex Deucher , Sasha Levin Subject: [PATCH 5.18 010/141] drm/amdkfd: Use mmget_not_zero in MMU notifier Date: Mon, 20 Jun 2022 14:49:08 +0200 Message-Id: <20220620124729.823328758@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220620124729.509745706@linuxfoundation.org> References: <20220620124729.509745706@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: 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 3b8856b4cece..5979335d7afd 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c @@ -2286,6 +2286,8 @@ 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; @@ -2312,6 +2314,7 @@ svm_range_cpu_invalidate_pagetables(struct mmu_interval_notifier *mni, } svm_range_unlock(prange); + mmput(mni->mm); return true; } -- 2.35.1