From patchwork Wed Aug 25 10:24:04 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: 503143 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=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 3DB9CC4338F for ; Wed, 25 Aug 2021 10:25:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1499D60F58 for ; Wed, 25 Aug 2021 10:25:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239901AbhHYK0n (ORCPT ); Wed, 25 Aug 2021 06:26:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40642 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239889AbhHYK0m (ORCPT ); Wed, 25 Aug 2021 06:26:42 -0400 Received: from mail-pj1-x102c.google.com (mail-pj1-x102c.google.com [IPv6:2607:f8b0:4864:20::102c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D7DE5C061757; Wed, 25 Aug 2021 03:25:56 -0700 (PDT) Received: by mail-pj1-x102c.google.com with SMTP id oc2-20020a17090b1c0200b00179e56772d6so3823765pjb.4; Wed, 25 Aug 2021 03:25:56 -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=Ba/aDvD1tkluhQ4EKS9mJop10MbwBdBq8p8q4FF7hME=; b=ERW9eAq0Yrphg27JkPRPoE9hi5ScahnBoNwNuz7HulCP62HFkrhXWI0nyJcIddIFn7 x9v/kxVidsNMcf+nTHom40evTH/p8ND8jqD3OS/vQtRzDdVvNsMuKCG9sUqIQL4To3EM hyNb7khUoqPlL/5qNG61XXHvm2smKgPyXj9NR5qFeSi1SnMGy9MQRa1ZpfuctgFw9rIP 1Jsx2sSz2YPUYO45juwlfJo3Q15Etj0c7enDb+styb1YpHQBOE2wQWJRUVQDwp4vNLDq 6yfvMoboiwSdcOp4nBSoEYBiUtH5IxObynxBbd5Nc6qiWjduuECQxYvcb2PLgL7buvOL BZ5Q== 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=Ba/aDvD1tkluhQ4EKS9mJop10MbwBdBq8p8q4FF7hME=; b=bfCsCOqnnldpTItdWKcz4lASbGZqLZE8cv6MgCUU4Wv3c50gCML3RT9n5uSkJWXreK ctQOeLRyn1Ce+2JuBXVqI79B5aWeokp9Jt2Pt/O+wM9RnunLDuC6WoUtoLxDkglwzs+G OmxsS4xM21wny0zP8VepsqS8bNMk1cKH05p/kG3RTcht4Nu8f0lCmqvIRGEBUfSlHB4N /Fa1/3Qv5vizURDC2VfyKsGJo6D0Q/eAI/0cRLxC68O2pR9egN262Q2goichQpLdt567 DucPRT6iVp4TzLJeDvgiooIb0DWQ0byiZnyNjVnX88M+SSBli5tlb2hJVQREBbtAS5cj pJzw== X-Gm-Message-State: AOAM533oip1Gzqm3wyW0XCYvPzcFXv32431jDiAWDUqigtQDphZcSMeE 9a5pFADBcnnIprxtuaeuEz8= X-Google-Smtp-Source: ABdhPJxh+Vt9oDZRXNiLgQBph5qkOp3i9zD+1yOu+rnkCFbGG36RMeKJz2sTzFwpPEwsICDPT2HhbQ== X-Received: by 2002:a17:90a:f696:: with SMTP id cl22mr4536225pjb.216.1629887156307; Wed, 25 Aug 2021 03:25:56 -0700 (PDT) Received: from localhost.localdomain ([118.200.190.93]) by smtp.gmail.com with ESMTPSA id t42sm10228377pfg.30.2021.08.25.03.25.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Aug 2021 03:25:55 -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 0/7] drm: update locking for modesetting Date: Wed, 25 Aug 2021 18:24:04 +0800 Message-Id: <20210825102411.1084220-1-desmondcheongzx@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org 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 v5 -> v6: - Fix recursive locking on master_rwsem, caught by the Intel-gfx CI (only current patch 5 & 6 changed) v4 -> v5: - Avoid calling drm_file_get_master while holding on to the modeset mutex, caught by the Intel-gfx CI 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 | 13 ++- 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, 249 insertions(+), 143 deletions(-)