From patchwork Wed Aug 25 14:21:58 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: 12457697 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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,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 71A6FC4320E for ; Wed, 25 Aug 2021 14:22:53 +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 1007161073 for ; Wed, 25 Aug 2021 14:22:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 1007161073 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 B1A0E6E221; Wed, 25 Aug 2021 14:22:51 +0000 (UTC) Received: from mail-pj1-x102c.google.com (mail-pj1-x102c.google.com [IPv6:2607:f8b0:4864:20::102c]) by gabe.freedesktop.org (Postfix) with ESMTPS id BA7AF6E21C; Wed, 25 Aug 2021 14:22:50 +0000 (UTC) Received: by mail-pj1-x102c.google.com with SMTP id h1so10796068pjs.2; Wed, 25 Aug 2021 07:22:50 -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:mime-version :content-transfer-encoding; bh=PyEUKLbqZIq1NMqrQWfaTXN/Z5gCejfRXXNJ7X/27zI=; b=Otb4pO56XogV3OPnTsbSnwXqDcs6r0tKYcZR1iNssiuYkYcMQ8PckQQk5CD/miFvvB YZnG4332bu9ZsuemG388tzhNs61duJY0Y/KMjR5S08oDCI/f54z5swJSvVfKtWrPVs6T OuNoyKyH75/wKOeVDs9BPzGZoaW4WgmwokdZAk10r16AriZK8yWzshiJ7QPD1tIiR4j4 QzPkHke0ApkC7BmIel9NpOhZX6skVucQ5cDWBE1sEkxud+kBXt03CWPE54DZpYbaPcNZ CGpeksEdBwtBmUERj/lWgptGdsYMR8NniWurGI+HmBGYyKp86SYp3LYEv8Bwuy5BttNW kemw== 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:mime-version :content-transfer-encoding; bh=PyEUKLbqZIq1NMqrQWfaTXN/Z5gCejfRXXNJ7X/27zI=; b=siAAIqkZmhqNxdH3YIPoGn01P5d7JMA5vOlcG0OlPeueVDa9opEh0tjmaxBseGedyi auPyt1Syq2trJrTZL6aHkYDRrckg4uWS82uCxg8myb4keJmhthV6d/37+WPj4qwiQRFS r8j0VhbFMHUilz3fRBiJtE3eYBXMeh45QQpNBKUaUwPs5G+lQ9g7ZzGOWvKg0xp2znsd o0ZOKhs+0GUX6A0woGwihBbHBCS/hbW9Wv7XxNJdgM9SlnRrK0hf8p90zGXZHgGSnzKS qqCNKv5bwfO731yVcalyUMLJ15WGTsKDjgyPZ54WnOXjmdh7Vx8Hcc/3TGh/943McRkg szIg== X-Gm-Message-State: AOAM532I4GSZYvPl31RaQCw6uc69Zn29U/iQQz1EYk6jfG7Xb92PDgnn /zzjUW2ygbEYwljnmgmkqgY= X-Google-Smtp-Source: ABdhPJxehXmLzPU7JznTC/D2Rq9/EqmHv+0cvyHdGLCWoO8H0/6/JPBhLtcGKA9lw/2OCfOujrZx3w== X-Received: by 2002:a17:90a:ae18:: with SMTP id t24mr9049661pjq.92.1629901370243; Wed, 25 Aug 2021 07:22:50 -0700 (PDT) Received: from localhost.localdomain ([118.200.190.93]) by smtp.gmail.com with ESMTPSA id n3sm54431pfo.101.2021.08.25.07.22.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Aug 2021 07:22:49 -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 v7 0/7] drm: update locking for modesetting Date: Wed, 25 Aug 2021 22:21:58 +0800 Message-Id: <20210825142205.1376789-1-desmondcheongzx@gmail.com> X-Mailer: git-send-email 2.25.1 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" Sorry for the noise. Sending out a new version because the Intel-gfx CI caught that __drm_mode_object_find has to be exported for loadable modules like the Intel and VMware DRM drivers. Hi, Updated the series again to avoid recursive locking caught by the Intel-gfx CI. Patch 5 touches a number of files, including the Intel and VMware drivers, but most changes are simply switching a function call to the appropriate locked/unlocked version. Overall, this series fixes races with modesetting rights, converts drm_device.master_mutex into master_rwsem, and removes drm_file.master_lookup_lock. - Patch 1: Fix a potential null ptr dereference in drm_master_release - Patch 2: Convert master_mutex into rwsem (avoids creating a new lock) - Patch 3: Update global mutex locking in the ioctl handler (avoids deadlock when grabbing read lock on master_rwsem in drm_ioctl_kernel) - Patch 4: Plug races with drm modesetting rights - Patch 5: Modify drm_mode_object_find to fix potential recursive locking of master_rwsem and lock inversions between modeset_mutex and master_rwsem - Patch 6: Remove remaining potential lock inversions between modeset_mutex and master_rwsem - Patch 7: Replace master_lookup_lock with master_rwsem v6 -> v7: - Export __drm_mode_object_find for loadable modules, caught by the Intel-gfx CI (patch 5) v5 -> v6: - Fix recursive locking on master_rwsem, caught by the Intel-gfx CI (patch 5 & 6) v4 -> v5: - Avoid calling drm_file_get_master while holding on to the modeset mutex, caught by the Intel-gfx CI (patch 5 & 6) v3 -> v4 (suggested by Daniel Vetter): - Drop a patch that added an unnecessary master_lookup_lock in drm_master_release - Drop a patch that addressed a non-existent race in drm_is_current_master_locked - Remove fixes for non-existent null ptr dereferences - Protect drm_master.magic_map,unique{_len} with master_rwsem instead of master_lookup_lock - Drop the patch that moved master_lookup_lock into struct drm_device - Drop a patch to export task_work_add - Revert the check for the global mutex in the ioctl handler to use drm_core_check_feature instead of drm_dev_needs_global_mutex - Push down master_rwsem locking for selected ioctls to avoid lock hierarchy inversions, and to allow us to hold write locks on master_rwsem instead of flushing readers - Remove master_lookup_lock by replacing it with master_rwsem v2 -> v3: - Unexport drm_master_flush, as suggested by Daniel Vetter. - Merge master_mutex and master_rwsem, as suggested by Daniel Vetter. - Export task_work_add, reported by kernel test robot. - Make master_flush static, reported by kernel test robot. - Move master_lookup_lock into struct drm_device. - Add a missing lock on master_lookup_lock in drm_master_release. - Fix a potential race in drm_is_current_master_locked. - Fix potential null ptr dereferences in drm_{auth, ioctl}. - Protect magic_map,unique{_len} with master_lookup_lock. - Convert master_mutex into a rwsem. - Update global mutex locking in the ioctl handler. v1 -> v2 (suggested by Daniel Vetter): - Address an additional race when drm_open runs. - Switch from SRCU to rwsem to synchronise readers and writers. - Implement drm_master_flush with task_work so that flushes can be queued to run before returning to userspace without creating a new DRM_MASTER_FLUSH ioctl flag. Best wishes, Desmond Desmond Cheong Zhi Xi (7): drm: fix null ptr dereference in drm_master_release drm: convert drm_device.master_mutex into a rwsem drm: lock drm_global_mutex earlier in the ioctl handler drm: avoid races with modesetting rights drm: avoid circular locks in drm_mode_object_find drm: avoid circular locks with modeset_mutex and master_rwsem drm: remove drm_file.master_lookup_lock drivers/gpu/drm/drm_atomic_uapi.c | 7 +- drivers/gpu/drm/drm_auth.c | 57 ++++++------ drivers/gpu/drm/drm_color_mgmt.c | 2 +- drivers/gpu/drm/drm_crtc.c | 5 +- drivers/gpu/drm/drm_debugfs.c | 4 +- drivers/gpu/drm/drm_drv.c | 3 +- drivers/gpu/drm/drm_encoder.c | 7 +- drivers/gpu/drm/drm_file.c | 7 +- drivers/gpu/drm/drm_framebuffer.c | 2 +- drivers/gpu/drm/drm_internal.h | 1 + drivers/gpu/drm/drm_ioctl.c | 48 ++++++---- drivers/gpu/drm/drm_lease.c | 94 ++++++++++---------- drivers/gpu/drm/drm_mode_object.c | 28 +++++- drivers/gpu/drm/drm_plane.c | 22 +++-- drivers/gpu/drm/drm_property.c | 6 +- drivers/gpu/drm/i915/display/intel_overlay.c | 2 +- drivers/gpu/drm/i915/display/intel_sprite.c | 2 +- drivers/gpu/drm/vmwgfx/vmwgfx_kms.c | 2 +- include/drm/drm_auth.h | 6 +- include/drm/drm_connector.h | 23 +++++ include/drm/drm_crtc.h | 22 +++++ include/drm/drm_device.h | 15 +++- include/drm/drm_file.h | 17 ++-- include/drm/drm_lease.h | 2 + include/drm/drm_mode_object.h | 3 + include/drm/drm_plane.h | 20 +++++ 26 files changed, 264 insertions(+), 143 deletions(-)