From patchwork Wed Aug 18 07:38:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Desmond Cheong Zhi Xi X-Patchwork-Id: 12443519 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=-10.7 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, UNWANTED_LANGUAGE_BODY,USER_AGENT_GIT autolearn=ham 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 74776C4338F for ; Wed, 18 Aug 2021 07:41:03 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3B53A60FDA for ; Wed, 18 Aug 2021 07:41:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 3B53A60FDA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id DF5576E461; Wed, 18 Aug 2021 07:41:01 +0000 (UTC) Received: from mail-pl1-x636.google.com (mail-pl1-x636.google.com [IPv6:2607:f8b0:4864:20::636]) by gabe.freedesktop.org (Postfix) with ESMTPS id 936CD6E461; Wed, 18 Aug 2021 07:40:59 +0000 (UTC) Received: by mail-pl1-x636.google.com with SMTP id n12so1277895plf.4; Wed, 18 Aug 2021 00:40:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=QEHuccOxvqNtSxSgci59cP9jo3dJUSb2vZvhFR8kmBM=; b=kyrTRnECEHbET1U8ahqUBcDC2k+PuuaNd2ZFISYrMAgnQWFXBkgRULnxtJd3D4A0Qk sv6Dy6gL1tZXoZf95+l5ZqMuBedFp7tD2JJ9vpU9tJZmG80Ru6fRUUErQa00tQF7JXal q4nkcdIu7vZAVlo48jb1ep26SNhQpD49gwhKdP9DhDK71KDMigl0pXVj+xgph1iYTpCV GEdyfy7nD9jCd6cWDxnfHI1Pl3E996Z52giWcXylPXYNY8AzLtKn/qEwWl6u46KGiJ2f tXSdXtqI2+YMaHhJ9XwkIBJrMaTN/Tr85hDUyG0oe6NBmufq+MqHUnY8beTAAQ7dkVvb zMZQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=QEHuccOxvqNtSxSgci59cP9jo3dJUSb2vZvhFR8kmBM=; b=KpS4gd/x26OSanW5TmWHFh8Kabvu7Bbtui7KWwdDkyHjscgozB4VbmLuxHrUTdSd8d dPV6q4yJl/1surYFeDEpCiOXtfndoN1EGwVzAzoCCuUtdByGXnpdBoHbWLuqbuANAda2 86RjbyFrxeFUgDVmVNyn9AZLnLf8ibU8/r9TDpJU0mQgM7QFcLCV0X+YYYmOee6KAnXs e3+kv5taf0VLdrnWHJbK5//eD2F8JFmkmfQYaKlpMFV+K0cDaPew2u3uoc6qBOl5GwD7 QrHIrg0xR8YKlbuh01FrqH6NSUrFUI46I+xkBI4aJfdcrqIMOxY73J4VZQVNBLNjC9xl 9xmw== X-Gm-Message-State: AOAM5310FWvncSkhHLNtMXwdo7JvYSyk2UgAXUxOF3zgjLgHQWBCk102 54qe7MHw0Uce3r3roZ8Y0Yw= X-Google-Smtp-Source: ABdhPJxoBfNvfFHKP3I6P1QO1863L8cr1aqR7zIgRwfSUR+ThNMh9rENh0OPTK/qPRiwQJIg/iQTmg== X-Received: by 2002:a17:90a:bf85:: with SMTP id d5mr8198209pjs.210.1629272459270; Wed, 18 Aug 2021 00:40:59 -0700 (PDT) Received: from localhost.localdomain ([118.200.190.93]) by smtp.gmail.com with ESMTPSA id u3sm3886729pjr.2.2021.08.18.00.40.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 18 Aug 2021 00:40:58 -0700 (PDT) From: Desmond Cheong Zhi Xi To: maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de, airlied@linux.ie, daniel@ffwll.ch, sumit.semwal@linaro.org, christian.koenig@amd.com, axboe@kernel.dk, oleg@redhat.com, tglx@linutronix.de, dvyukov@google.com, walter-zh.wu@mediatek.com Cc: Desmond Cheong Zhi Xi , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org, linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, skhan@linuxfoundation.org, gregkh@linuxfoundation.org, linux-kernel-mentees@lists.linuxfoundation.org Subject: [PATCH v3 5/9] drm: protect magic_map, unique{_len} with master_lookup_lock Date: Wed, 18 Aug 2021 15:38:20 +0800 Message-Id: <20210818073824.1560124-6-desmondcheongzx@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210818073824.1560124-1-desmondcheongzx@gmail.com> References: <20210818073824.1560124-1-desmondcheongzx@gmail.com> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Currently, drm_device.master_mutex is used to serialize writes to the drm_master.magic_map idr and to protect drm_master.unique{_len}. In preparation for converting drm_device.master_mutex into an outer rwsem that might be read locked before entering some of these functions, we can instead serialize access to drm_master.magic_map and drm_master.unique{_len} using drm_device.master_lookup_lock which is an inner lock. Signed-off-by: Desmond Cheong Zhi Xi --- drivers/gpu/drm/drm_auth.c | 12 +++++++----- drivers/gpu/drm/drm_ioctl.c | 10 ++++++---- include/drm/drm_auth.h | 6 +++--- include/drm/drm_device.h | 7 ++++++- 4 files changed, 22 insertions(+), 13 deletions(-) diff --git a/drivers/gpu/drm/drm_auth.c b/drivers/gpu/drm/drm_auth.c index b7230604496b..0acb444fbbac 100644 --- a/drivers/gpu/drm/drm_auth.c +++ b/drivers/gpu/drm/drm_auth.c @@ -98,10 +98,10 @@ int drm_getmagic(struct drm_device *dev, void *data, struct drm_file *file_priv) struct drm_master *master; int ret = 0; - mutex_lock(&dev->master_mutex); + spin_lock(&dev->master_lookup_lock); master = file_priv->master; if (!master) { - mutex_unlock(&dev->master_mutex); + spin_unlock(&dev->master_lookup_lock); return -EINVAL; } @@ -112,7 +112,7 @@ int drm_getmagic(struct drm_device *dev, void *data, struct drm_file *file_priv) file_priv->magic = ret; } auth->magic = file_priv->magic; - mutex_unlock(&dev->master_mutex); + spin_unlock(&dev->master_lookup_lock); DRM_DEBUG("%u\n", auth->magic); @@ -127,13 +127,13 @@ int drm_authmagic(struct drm_device *dev, void *data, DRM_DEBUG("%u\n", auth->magic); - mutex_lock(&dev->master_mutex); + spin_lock(&dev->master_lookup_lock); file = idr_find(&file_priv->master->magic_map, auth->magic); if (file) { file->authenticated = 1; idr_replace(&file_priv->master->magic_map, NULL, auth->magic); } - mutex_unlock(&dev->master_mutex); + spin_unlock(&dev->master_lookup_lock); return file ? 0 : -EINVAL; } @@ -366,8 +366,10 @@ void drm_master_release(struct drm_file *file_priv) if (!master) goto unlock; + spin_lock(&dev->master_lookup_lock); if (file_priv->magic) idr_remove(&master->magic_map, file_priv->magic); + spin_unlock(&dev->master_lookup_lock); if (!drm_is_current_master_locked(file_priv)) goto out; diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c index 4d029d3061d9..e5c3845b6e62 100644 --- a/drivers/gpu/drm/drm_ioctl.c +++ b/drivers/gpu/drm/drm_ioctl.c @@ -119,21 +119,21 @@ int drm_getunique(struct drm_device *dev, void *data, struct drm_unique *u = data; struct drm_master *master; - mutex_lock(&dev->master_mutex); + spin_lock(&dev->master_lookup_lock); master = file_priv->master; if (!master) { - mutex_unlock(&dev->master_mutex); + spin_unlock(&dev->master_lookup_lock); return -EINVAL; } if (u->unique_len >= master->unique_len) { if (copy_to_user(u->unique, master->unique, master->unique_len)) { - mutex_unlock(&dev->master_mutex); + spin_unlock(&dev->master_lookup_lock); return -EFAULT; } } u->unique_len = master->unique_len; - mutex_unlock(&dev->master_mutex); + spin_unlock(&dev->master_lookup_lock); return 0; } @@ -405,7 +405,9 @@ static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *f * Version 1.1 includes tying of DRM to specific device * Version 1.4 has proper PCI domain support */ + spin_lock(&dev->master_lookup_lock); retcode = drm_set_busid(dev, file_priv); + spin_unlock(&dev->master_lookup_lock); if (retcode) goto done; } diff --git a/include/drm/drm_auth.h b/include/drm/drm_auth.h index ba248ca8866f..f5be73153798 100644 --- a/include/drm/drm_auth.h +++ b/include/drm/drm_auth.h @@ -67,17 +67,17 @@ struct drm_master { struct drm_device *dev; /** * @unique: Unique identifier: e.g. busid. Protected by - * &drm_device.master_mutex. + * &drm_device.master_lookup_lock. */ char *unique; /** * @unique_len: Length of unique field. Protected by - * &drm_device.master_mutex. + * &drm_device.master_lookup_lock. */ int unique_len; /** * @magic_map: Map of used authentication tokens. Protected by - * &drm_device.master_mutex. + * &drm_device.master_lookup_lock. */ struct idr magic_map; void *driver_priv; diff --git a/include/drm/drm_device.h b/include/drm/drm_device.h index 506eb2784819..cf5d15aeb25f 100644 --- a/include/drm/drm_device.h +++ b/include/drm/drm_device.h @@ -152,7 +152,12 @@ struct drm_device { */ struct mutex master_mutex; - /** @master_lookup_lock: Serializes &drm_file.master. */ + /** + * @master_lookup_lock: + * + * Serializes &drm_file.master, &drm_master.magic_map, + * &drm_master.unique, and &drm_master.unique_len. + */ spinlock_t master_lookup_lock; /**