From 2412e54d26084737d59d26e1296b24fd03258431 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Tue, 19 Jun 2018 17:42:35 +0200 Subject: drm/atomic-helpers: remove legacy_cursor_update hacks MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The stuff never really worked, and leads to lots of fun because it out-of-order frees atomic states. Which upsets KASAN, among other things. For async updates we now have a more solid solution with the ->atomic_async_check and ->atomic_async_commit hooks. Support for that for msm and vc4 landed. nouveau and i915 have their own commit routines, doing something similar. For everyone else it's probably better to remove the use-after-free bug, and encourage folks to use the async support instead. The affected drivers which register a legacy cursor plane and don't either use the new async stuff or their own commit routine are: amdgpu, atmel, mediatek, qxl, rockchip, sti, sun4i, tegra, virtio, and vmwgfx. Inspired by an amdgpu bug report. v2: Drop RFC, I think with amdgpu converted over to use atomic_async_check/commit done in commit 674e78acae0dfb4beb56132e41cbae5b60f7d662 Author: Nicholas Kazlauskas Date: Wed Dec 5 14:59:07 2018 -0500 drm/amd/display: Add fast path for cursor plane updates we don't have any driver anymore where we have userspace expecting solid legacy cursor support _and_ they are using the atomic helpers in their fully glory. So we can retire this. v3: Paper over msm and i915 regression. The complete_all is the only thing missing afaict. v4: Fixup i915 fixup ... v5: Unallocate the crtc->event in msm to avoid hitting a WARN_ON in dpu_crtc_atomic_flush(). This is a bit a hack, but simplest way to untangle this all. Thanks to Abhinav Kumar for the debug help. Cc: Abhinav Kumar Cc: Thomas Zimmermann Cc: Maxime Ripard References: https://bugzilla.kernel.org/show_bug.cgi?id=199425 References: https://lore.kernel.org/all/20220221134155.125447-9-maxime@cerno.tech/ References: https://bugzilla.kernel.org/show_bug.cgi?id=199425 Cc: Maxime Ripard Tested-by: Maxime Ripard Cc: mikita.lipski@amd.com Cc: Michel Dänzer Cc: harry.wentland@amd.com Cc: Rob Clark Cc: "Kazlauskas, Nicholas" Cc: Dmitry Osipenko Cc: Maarten Lankhorst Cc: Dmitry Baryshkov Cc: Sean Paul Cc: Matthias Brugger Cc: AngeloGioacchino Del Regno Cc: "Ville Syrjälä" Cc: Jani Nikula Cc: Lucas De Marchi Cc: Imre Deak Cc: Manasi Navare Cc: linux-arm-msm@vger.kernel.org Cc: freedreno@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mediatek@lists.infradead.org Signed-off-by: Daniel Vetter --- drivers/gpu/drm/drm_atomic_helper.c | 13 ------------- drivers/gpu/drm/i915/display/intel_display.c | 14 ++++++++++++++ drivers/gpu/drm/msm/msm_atomic.c | 15 +++++++++++++++ 3 files changed, 29 insertions(+), 13 deletions(-) diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index 39ef0a6addeb..40c2bd3e62e8 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -1650,13 +1650,6 @@ drm_atomic_helper_wait_for_vblanks(struct drm_device *dev, int i, ret; unsigned int crtc_mask = 0; - /* - * Legacy cursor ioctls are completely unsynced, and userspace - * relies on that (by doing tons of cursor updates). - */ - if (old_state->legacy_cursor_update) - return; - for_each_oldnew_crtc_in_state(old_state, crtc, old_crtc_state, new_crtc_state, i) { if (!new_crtc_state->active) continue; @@ -2307,12 +2300,6 @@ int drm_atomic_helper_setup_commit(struct drm_atomic_state *state, continue; } - /* Legacy cursor updates are fully unsynced. */ - if (state->legacy_cursor_update) { - complete_all(&commit->flip_done); - continue; - } - if (!new_crtc_state->event) { commit->event = kzalloc(sizeof(*commit->event), GFP_KERNEL); diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c index 927d124457b6..65c45269d6e4 100644 --- a/drivers/gpu/drm/i915/display/intel_display.c +++ b/drivers/gpu/drm/i915/display/intel_display.c @@ -7360,6 +7360,20 @@ int intel_atomic_commit(struct drm_device *dev, struct drm_atomic_state *_state, intel_runtime_pm_put(&dev_priv->runtime_pm, state->wakeref); return ret; } + + /* + * FIXME: Cut over to (async) commit helpers instead of hand-rolling + * everything. + */ + if (state->base.legacy_cursor_update) { + struct intel_crtc_state *new_crtc_state; + struct intel_crtc *crtc; + int i; + + for_each_new_intel_crtc_in_state(state, crtc, new_crtc_state, i) + complete_all(&new_crtc_state->uapi.commit->flip_done); + } + intel_shared_dpll_swap_state(state); intel_atomic_track_fbs(state); diff --git a/drivers/gpu/drm/msm/msm_atomic.c b/drivers/gpu/drm/msm/msm_atomic.c index 9c45d641b521..92591d35775a 100644 --- a/drivers/gpu/drm/msm/msm_atomic.c +++ b/drivers/gpu/drm/msm/msm_atomic.c @@ -208,6 +208,19 @@ void msm_atomic_commit_tail(struct drm_atomic_state *state) unsigned crtc_mask = get_crtc_mask(state); bool async = can_do_async(state, &async_crtc); + /* + * FIXME: Convert to async plane helpers and remove the various hacks to + * keep the old legacy_cursor_way of doing async commits working for the + * dpu code, like the expectation that these don't have a crtc->event. + */ + if (async) { + /* both ->event itself and the pointer hold a reference! */ + drm_crtc_commit_put(async_crtc->state->commit); + drm_crtc_commit_put(async_crtc->state->commit); + kfree(async_crtc->state->event); + async_crtc->state->event = NULL; + } + trace_msm_atomic_commit_tail_start(async, crtc_mask); kms->funcs->enable_commit(kms); @@ -242,6 +255,8 @@ void msm_atomic_commit_tail(struct drm_atomic_state *state) /* async updates are limited to single-crtc updates: */ WARN_ON(crtc_mask != drm_crtc_mask(async_crtc)); + complete_all(&async_crtc->state->commit->flip_done); + /* * Start timer if we don't already have an update pending * on this crtc: -- cgit v1.2.3