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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 F0522C43603 for ; Thu, 19 Dec 2019 18:58:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BC256227BF for ; Thu, 19 Dec 2019 18:58:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576781907; bh=jM4AaFsdUm+PCgilD4TxVD2a/AGAmFNdPl4DlFC+EvU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ttfa/lwxHcf5CuEistUP/WzsXqkMl6Rl+zjxed6oUv4tvb0n97qX12PYruNQHHRlW HvJAi0hKXc4+psYv2B7odp97BATbcg9Vjgawpq+Xf7qymY74wV2dz6I5RC0C/wNVij Jlk8jzlTvuBlktxY9i9yH0qRe5AYQx3ALwFKFUKo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726959AbfLSS6W (ORCPT ); Thu, 19 Dec 2019 13:58:22 -0500 Received: from mail.kernel.org ([198.145.29.99]:50536 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730273AbfLSSyz (ORCPT ); Thu, 19 Dec 2019 13:54:55 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9334D206EC; Thu, 19 Dec 2019 18:54:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576781695; bh=jM4AaFsdUm+PCgilD4TxVD2a/AGAmFNdPl4DlFC+EvU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Nwpdwecqpy74LXwL7VivJDnDmds/T6W3ciX2Cd5CHPGlxtUEaMVE2QAn+23C5M1A4 6cMV3h4eDytV5X07Eqxy9lMTX65fcum3wX74yw1XIBYk6gqzBRMlTPPtt/qrYlkgGz UfC4+PVqHLt5eaDOjy/qBD/ctQXqFX889KGQ6zM8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Boris Brezillon , Steven Price , Alyssa Rosenzweig , Rob Herring Subject: [PATCH 5.4 43/80] drm/panfrost: Fix a race in panfrost_ioctl_madvise() Date: Thu, 19 Dec 2019 19:34:35 +0100 Message-Id: <20191219183111.174687637@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20191219183031.278083125@linuxfoundation.org> References: <20191219183031.278083125@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Boris Brezillon commit 70cc77952efebf6722d483cb83cfb563ac9768db upstream. If 2 threads change the MADVISE property of the same BO in parallel we might end up with an shmem->madv value that's inconsistent with the presence of the BO in the shrinker list. The easiest solution to fix that is to protect the drm_gem_shmem_madvise() call with the shrinker lock. Fixes: 013b65101315 ("drm/panfrost: Add madvise and shrinker support") Cc: Signed-off-by: Boris Brezillon Reviewed-by: Steven Price Acked-by: Alyssa Rosenzweig Signed-off-by: Rob Herring Link: https://patchwork.freedesktop.org/patch/msgid/20191129135908.2439529-3-boris.brezillon@collabora.com Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/panfrost/panfrost_drv.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) --- a/drivers/gpu/drm/panfrost/panfrost_drv.c +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c @@ -347,20 +347,19 @@ static int panfrost_ioctl_madvise(struct return -ENOENT; } + mutex_lock(&pfdev->shrinker_lock); args->retained = drm_gem_shmem_madvise(gem_obj, args->madv); if (args->retained) { struct panfrost_gem_object *bo = to_panfrost_bo(gem_obj); - mutex_lock(&pfdev->shrinker_lock); - if (args->madv == PANFROST_MADV_DONTNEED) - list_add_tail(&bo->base.madv_list, &pfdev->shrinker_list); + list_add_tail(&bo->base.madv_list, + &pfdev->shrinker_list); else if (args->madv == PANFROST_MADV_WILLNEED) list_del_init(&bo->base.madv_list); - - mutex_unlock(&pfdev->shrinker_lock); } + mutex_unlock(&pfdev->shrinker_lock); drm_gem_object_put_unlocked(gem_obj); return 0;