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=-15.8 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,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 53CC9C432BE for ; Wed, 25 Aug 2021 10:27:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4025C61184 for ; Wed, 25 Aug 2021 10:27:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240277AbhHYK16 (ORCPT ); Wed, 25 Aug 2021 06:27:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40992 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240091AbhHYK1n (ORCPT ); Wed, 25 Aug 2021 06:27:43 -0400 Received: from mail-pl1-x630.google.com (mail-pl1-x630.google.com [IPv6:2607:f8b0:4864:20::630]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1499AC0613C1; Wed, 25 Aug 2021 03:26:58 -0700 (PDT) Received: by mail-pl1-x630.google.com with SMTP id b9so9678439plx.2; Wed, 25 Aug 2021 03:26:58 -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=uk23yrQj2bYGx5iUQvrvtVaf8WaEKXc6e3h1Qpr0Wxc=; b=BWSKA8AUjVQ50e47odJHTUdgySf+Ui5SxD63HSnvhT3Y2nW/W0LeIK7ED0XXqlgOPp CnsORRw46Z0JjgWe4AAS+3YKmgLO8GFneYav7pypBwEoTFNCsPlberP+D66TxmKp9zGl bDgTWZNHKNUbpQ/UlWFVE2rwq4pfH/42C3u/yCdpo4ffhPFp9xooRzeQTPl79EEtYNqT 7uXvOAApPrrARRsuZmogj9TBFTMqJfZnALu0o8OujnrBJ1Eo0AOSSOadPyLqxxfhkURH ve+E6G3HuuqLW4pSke2ZTWl4gScZpH/UHzFkdbpvUfaykvjzBjYoXchp8pFKfaNqH21u wO9Q== 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=uk23yrQj2bYGx5iUQvrvtVaf8WaEKXc6e3h1Qpr0Wxc=; b=nZsSv6aJdO6/SLL6kJd91C1wKjbStCEoGot536s4qt6061DKMM2SKASkLQhyfiDayJ vWh5O/VDa9kS/vQBoImbHy6sqJZFmWeoh0Y8Vem2tqGKVDAnP+BppZRVW5KQHl5Alp5P QulSUXRy1b9WStaFS1uEUILQM3wcbyfjjk2WCsaR/2iSuNOdWRi+5uM0rOHSPkeA4onY Y/m5kNR/9PZMQfZc0RrhC9J2DNRSXk9RcNQKg7ZxrZEeEBQ8alaWJRzNcgFmRGR9HK7N nrdxj6ozLmbWFTJc7HPo3xdgN+bs3nspAjbpS2quAgAAD2kaYN93ow/FvL3bXjbjVFh0 BabA== X-Gm-Message-State: AOAM531uQEmq67JByBvwFr5zMejXnYQGkJ/QbL0A/ru/wLsm5g333C1B +BYJDkCp+qGpb4ym4ZeCb6g= X-Google-Smtp-Source: ABdhPJytkjiDZ8qPb5DBfLVt7ff+o3cMdp+LthsSPCnnII0Plz6+Bb78f8IMUv18k6LCIVbqrGYgJA== X-Received: by 2002:a17:90b:384a:: with SMTP id nl10mr9780352pjb.65.1629887217646; Wed, 25 Aug 2021 03:26:57 -0700 (PDT) Received: from localhost.localdomain ([118.200.190.93]) by smtp.gmail.com with ESMTPSA id t42sm10228377pfg.30.2021.08.25.03.26.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Aug 2021 03:26:57 -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, jani.nikula@linux.intel.com, joonas.lahtinen@linux.intel.com, rodrigo.vivi@intel.com, chris@chris-wilson.co.uk, ville.syrjala@linux.intel.com, matthew.auld@intel.com, dan.carpenter@oracle.com, tvrtko.ursulin@intel.com, matthew.d.roper@intel.com, lucas.demarchi@intel.com, karthik.b.s@intel.com, jose.souza@intel.com, manasi.d.navare@intel.com, airlied@redhat.com, aditya.swarup@intel.com, andrescj@chromium.org, linux-graphics-maintainer@vmware.com, zackr@vmware.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 v6 6/7] drm: avoid circular locks with modeset_mutex and master_rwsem Date: Wed, 25 Aug 2021 18:24:10 +0800 Message-Id: <20210825102411.1084220-7-desmondcheongzx@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210825102411.1084220-1-desmondcheongzx@gmail.com> References: <20210825102411.1084220-1-desmondcheongzx@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org drm_lease_held calls drm_file_get_master. However, this function is sometimes called while holding on to modeset_mutex. Since drm_device.master_rwsem will replace drm_file.master_lookup_lock in drm_file_get_master in a future patch, this inverts the master_rwsem --> modeset_mutex lock hierarchy. To fix this, we create a new drm_lease_held_master helper function that enables us to avoid calling drm_file_get_master after locking modeset_mutex. Signed-off-by: Desmond Cheong Zhi Xi --- drivers/gpu/drm/drm_auth.c | 3 +++ drivers/gpu/drm/drm_encoder.c | 7 ++++++- drivers/gpu/drm/drm_lease.c | 30 +++++++++++++++--------------- drivers/gpu/drm/drm_plane.c | 14 +++++++++++--- include/drm/drm_lease.h | 2 ++ 5 files changed, 37 insertions(+), 19 deletions(-) diff --git a/drivers/gpu/drm/drm_auth.c b/drivers/gpu/drm/drm_auth.c index 65065f7e1499..f2b2f197052a 100644 --- a/drivers/gpu/drm/drm_auth.c +++ b/drivers/gpu/drm/drm_auth.c @@ -410,6 +410,9 @@ struct drm_master *drm_file_get_master(struct drm_file *file_priv) { struct drm_master *master = NULL; + if (!file_priv) + return NULL; + spin_lock(&file_priv->master_lookup_lock); if (!file_priv->master) goto unlock; diff --git a/drivers/gpu/drm/drm_encoder.c b/drivers/gpu/drm/drm_encoder.c index 72e982323a5e..bacb2f6a325c 100644 --- a/drivers/gpu/drm/drm_encoder.c +++ b/drivers/gpu/drm/drm_encoder.c @@ -22,6 +22,7 @@ #include +#include #include #include #include @@ -281,6 +282,7 @@ int drm_mode_getencoder(struct drm_device *dev, void *data, struct drm_mode_get_encoder *enc_resp = data; struct drm_encoder *encoder; struct drm_crtc *crtc; + struct drm_master *master; if (!drm_core_check_feature(dev, DRIVER_MODESET)) return -EOPNOTSUPP; @@ -289,13 +291,16 @@ int drm_mode_getencoder(struct drm_device *dev, void *data, if (!encoder) return -ENOENT; + master = drm_file_get_master(file_priv); drm_modeset_lock(&dev->mode_config.connection_mutex, NULL); crtc = drm_encoder_get_crtc(encoder); - if (crtc && drm_lease_held(file_priv, crtc->base.id)) + if (crtc && drm_lease_held_master(master, crtc->base.id)) enc_resp->crtc_id = crtc->base.id; else enc_resp->crtc_id = 0; drm_modeset_unlock(&dev->mode_config.connection_mutex); + if (master) + drm_master_put(&master); enc_resp->encoder_type = encoder->encoder_type; enc_resp->encoder_id = encoder->base.id; diff --git a/drivers/gpu/drm/drm_lease.c b/drivers/gpu/drm/drm_lease.c index 1b156c85d1c8..15bf3a3c76d1 100644 --- a/drivers/gpu/drm/drm_lease.c +++ b/drivers/gpu/drm/drm_lease.c @@ -114,27 +114,30 @@ bool _drm_lease_held(struct drm_file *file_priv, int id) return _drm_lease_held_master(file_priv->master, id); } -bool drm_lease_held(struct drm_file *file_priv, int id) +bool drm_lease_held_master(struct drm_master *master, int id) { - struct drm_master *master; bool ret; - if (!file_priv) + if (!master || !master->lessor) return true; - master = drm_file_get_master(file_priv); - if (!master) - return true; - if (!master->lessor) { - ret = true; - goto out; - } mutex_lock(&master->dev->mode_config.idr_mutex); ret = _drm_lease_held_master(master, id); mutex_unlock(&master->dev->mode_config.idr_mutex); -out: - drm_master_put(&master); + return ret; +} + +bool drm_lease_held(struct drm_file *file_priv, int id) +{ + struct drm_master *master; + bool ret; + + master = drm_file_get_master(file_priv); + ret = drm_lease_held_master(master, id); + if (master) + drm_master_put(&master); + return ret; } @@ -150,9 +153,6 @@ 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) - return crtcs_in; - master = drm_file_get_master(file_priv); if (!master) return crtcs_in; diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c index b5566167a798..af9f65bf74d4 100644 --- a/drivers/gpu/drm/drm_plane.c +++ b/drivers/gpu/drm/drm_plane.c @@ -23,6 +23,7 @@ #include #include +#include #include #include #include @@ -687,6 +688,7 @@ int drm_mode_getplane(struct drm_device *dev, void *data, struct drm_mode_get_plane *plane_resp = data; struct drm_plane *plane; uint32_t __user *format_ptr; + struct drm_master *master; if (!drm_core_check_feature(dev, DRIVER_MODESET)) return -EOPNOTSUPP; @@ -695,10 +697,13 @@ int drm_mode_getplane(struct drm_device *dev, void *data, if (!plane) return -ENOENT; + master = drm_file_get_master(file_priv); drm_modeset_lock(&plane->mutex, NULL); - if (plane->state && plane->state->crtc && drm_lease_held(file_priv, plane->state->crtc->base.id)) + if (plane->state && plane->state->crtc && + drm_lease_held_master(master, plane->state->crtc->base.id)) plane_resp->crtc_id = plane->state->crtc->base.id; - else if (!plane->state && plane->crtc && drm_lease_held(file_priv, plane->crtc->base.id)) + else if (!plane->state && plane->crtc && + drm_lease_held_master(master, plane->crtc->base.id)) plane_resp->crtc_id = plane->crtc->base.id; else plane_resp->crtc_id = 0; @@ -710,6 +715,8 @@ int drm_mode_getplane(struct drm_device *dev, void *data, else plane_resp->fb_id = 0; drm_modeset_unlock(&plane->mutex); + if (master) + drm_master_put(&master); plane_resp->plane_id = plane->base.id; plane_resp->possible_crtcs = drm_lease_filter_crtcs(file_priv, @@ -1114,6 +1121,7 @@ static int drm_mode_cursor_common(struct drm_device *dev, return -ENOENT; } + lockdep_assert_held_once(&dev->master_rwsem); drm_modeset_acquire_init(&ctx, DRM_MODESET_ACQUIRE_INTERRUPTIBLE); retry: ret = drm_modeset_lock(&crtc->mutex, &ctx); @@ -1128,7 +1136,7 @@ static int drm_mode_cursor_common(struct drm_device *dev, if (ret) goto out; - if (!drm_lease_held(file_priv, crtc->cursor->base.id)) { + if (file_priv && !drm_lease_held_master(file_priv->master, crtc->cursor->base.id)) { ret = -EACCES; goto out; } diff --git a/include/drm/drm_lease.h b/include/drm/drm_lease.h index 5c9ef6a2aeae..426ea86d3c6a 100644 --- a/include/drm/drm_lease.h +++ b/include/drm/drm_lease.h @@ -18,6 +18,8 @@ bool drm_lease_held(struct drm_file *file_priv, int id); bool _drm_lease_held(struct drm_file *file_priv, int id); +bool drm_lease_held_master(struct drm_master *master, int id); + void drm_lease_revoke(struct drm_master *master); uint32_t drm_lease_filter_crtcs(struct drm_file *file_priv, uint32_t crtcs); -- 2.25.1