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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 007BBC11F6A for ; Wed, 30 Jun 2021 00:16:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D3A6B61D1A for ; Wed, 30 Jun 2021 00:16:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235618AbhF3ASx (ORCPT ); Tue, 29 Jun 2021 20:18:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34898 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233056AbhF3ASw (ORCPT ); Tue, 29 Jun 2021 20:18:52 -0400 Received: from mail-ot1-x334.google.com (mail-ot1-x334.google.com [IPv6:2607:f8b0:4864:20::334]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 45D16C061760; Tue, 29 Jun 2021 17:16:23 -0700 (PDT) Received: by mail-ot1-x334.google.com with SMTP id o17-20020a9d76510000b02903eabfc221a9so837069otl.0; Tue, 29 Jun 2021 17:16:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=TeU+3+BSYIPpIeuTqgZDRxi1yeuqH6v4tOX7y63fgHw=; b=XKDqX3TPtx+FM7XOGFT5ZxxIRnOGdcF7kmoOpeRxvJSLbMexAdV711roiibP4qR76q KT76AWQgueP1tZo03SIm3YWwMpUcHfF3jKmNbrm+XwvnbzZDcmGbFiVFNkv6db1TtrGf DGIgsilQzPkOKh0TKSnJ/MGueuZFhCQB0kSIwOb7CU2RSO+5GT8JMUvUWELpgGhRJYG9 zoc5Yq/PetkBCi9nvCuSFE/DIJWYVnn3GuAIuwPrXnWt/OeNTOE4Nyy9uMPdS1gSGmHA 5Kz2gJgQjVrKojgqR6WDet/Di5tgLLQqlXIJ5jyoS8fTZSk0PyD1Z5K52Gjezw/vmrK+ qiuA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=TeU+3+BSYIPpIeuTqgZDRxi1yeuqH6v4tOX7y63fgHw=; b=oslnvladO20tibh+lJmk4eOUXC2BKpC+Dvx4qWZ6fz+DjzJMkjraVyP4pUsr8AzY7C f3mtz5Va3O77YHdCS8yMQMZsFThdO8S1+neCl3aJ47MQ5UoWavbva0Hg0ZEQQ/uWKVVi zkmZPkTbeN2SjfJAJg5ssCgs+t1DhmjQ1i59Rgrn6BeAvvE1AUu83BImh8I+wW0zzxlZ JCWZFoHvNr22ULK9syG7D3GOyXURMtvn0s7ZutKD8IEOFuqbAh6Gv2zJmSwxyeZ2txF/ NVjpGcsvhVRoJm/YQIn/3AkPFehN5m7yBJ1BgIM6tNjFeRI5CVfkGIOipK4ayKDEvCvo 0iOQ== X-Gm-Message-State: AOAM532iPpch0X75lbXT566BtZAUKrtYsaTTD/PgOYQKcgIjKRzSyK7b bPEX8P4aivx/ZReKqZ3qUT2xAbC4zZntmR0pJ8k= X-Google-Smtp-Source: ABdhPJx34XXa9kHNh6uvHXEDImmKhDaL6BZO5KazFWN+0la39xePneKq3e4T3vbCD/IXdwpTxTXiC0j8xj4riZHpj8M= X-Received: by 2002:a9d:1b41:: with SMTP id l59mr6810295otl.8.1625012182689; Tue, 29 Jun 2021 17:16:22 -0700 (PDT) MIME-Version: 1.0 References: <20210629033706.20537-1-desmondcheongzx@gmail.com> <20210629033706.20537-4-desmondcheongzx@gmail.com> In-Reply-To: <20210629033706.20537-4-desmondcheongzx@gmail.com> From: Emil Velikov Date: Wed, 30 Jun 2021 01:16:10 +0100 Message-ID: Subject: Re: [PATCH v5 3/3] drm: protect drm_master pointers in drm_lease.c To: Desmond Cheong Zhi Xi Cc: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Dave Airlie , Daniel Vetter , Sumit Semwal , =?UTF-8?Q?Christian_K=C3=B6nig?= , ML dri-devel , Intel Graphics Development , "Linux-Kernel@Vger. Kernel. Org" , linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, skhan@linuxfoundation.org, Greg Kroah-Hartman , linux-kernel-mentees@lists.linuxfoundation.org, Daniel Vetter Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Desmond, Couple of small suggestions, with those the series is: Reviewed-by: Emil Velikov On Tue, 29 Jun 2021 at 04:38, Desmond Cheong Zhi Xi wrote: > @@ -128,13 +137,20 @@ bool drm_lease_held(struct drm_file *file_priv, int id) > struct drm_master *master; > bool ret; > > - if (!file_priv || !file_priv->master || !file_priv->master->lessor) > + if (!file_priv) > return true; > > - master = file_priv->master; > + master = drm_file_get_master(file_priv); > + if (master == NULL) > + return true; > + if (!master->lessor) { > + drm_master_put(&master); > + return true; Let's add a "ret = true; goto unlock;" here, so we can have a single drm_master_put() in the function. Nearly all code paths touched by this patch already follow this approach. > @@ -154,10 +170,16 @@ uint32_t drm_lease_filter_crtcs(struct drm_file *file_priv, uint32_t crtcs_in) > int count_in, count_out; > uint32_t crtcs_out = 0; > > - if (!file_priv || !file_priv->master || !file_priv->master->lessor) > + if (!file_priv) > return crtcs_in; > > - master = file_priv->master; > + master = drm_file_get_master(file_priv); > + if (master == NULL) > + return crtcs_in; > + if (!master->lessor) { > + drm_master_put(&master); > + return crtcs_in; Ditto Thanks Emil