From 968029057192e46dd78e807b81c2aba2d7648c38 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Mon, 5 Nov 2018 11:12:11 +0100 Subject: [PATCH] drm/lease: look at ->universal_planes only once It's lockless, and userspace might chance it underneath us. That's not really a problem, all userspace gets is a slightly dysfunctional lease with the current code. But this might change, and gcc might decide to reload a few too many times, and then boom. So better safe than sorry. v2: Remove the now unused lessor_priv argument from validate_lease() (Keith). v3: Actually add everything ... silly me. Cc: Keith Packard Cc: Dave Airlie Acked-by: Keith Packard Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20181105101211.22737-1-daniel.vetter@ffwll.ch --- drivers/gpu/drm/drm_lease.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/drm_lease.c b/drivers/gpu/drm/drm_lease.c index 4cfd8fe25536..3b367e07c87e 100644 --- a/drivers/gpu/drm/drm_lease.c +++ b/drivers/gpu/drm/drm_lease.c @@ -353,9 +353,9 @@ void drm_lease_revoke(struct drm_master *top) } static int validate_lease(struct drm_device *dev, - struct drm_file *lessor_priv, int object_count, - struct drm_mode_object **objects) + struct drm_mode_object **objects, + bool universal_planes) { int o; int has_crtc = -1; @@ -372,14 +372,14 @@ static int validate_lease(struct drm_device *dev, if (objects[o]->type == DRM_MODE_OBJECT_CONNECTOR && has_connector == -1) has_connector = o; - if (lessor_priv->universal_planes) { + if (universal_planes) { if (objects[o]->type == DRM_MODE_OBJECT_PLANE && has_plane == -1) has_plane = o; } } if (has_crtc == -1 || has_connector == -1) return -EINVAL; - if (lessor_priv->universal_planes && has_plane == -1) + if (universal_planes && has_plane == -1) return -EINVAL; return 0; } @@ -393,6 +393,8 @@ static int fill_object_idr(struct drm_device *dev, struct drm_mode_object **objects; u32 o; int ret; + bool universal_planes = READ_ONCE(lessor_priv->universal_planes); + objects = kcalloc(object_count, sizeof(struct drm_mode_object *), GFP_KERNEL); if (!objects) @@ -421,7 +423,7 @@ static int fill_object_idr(struct drm_device *dev, } } - ret = validate_lease(dev, lessor_priv, object_count, objects); + ret = validate_lease(dev, object_count, objects, universal_planes); if (ret) { DRM_DEBUG_LEASE("lease validation failed\n"); goto out_free_objects; @@ -448,7 +450,7 @@ static int fill_object_idr(struct drm_device *dev, object_id, ret); goto out_free_objects; } - if (obj->type == DRM_MODE_OBJECT_CRTC && !lessor_priv->universal_planes) { + if (obj->type == DRM_MODE_OBJECT_CRTC && !universal_planes) { struct drm_crtc *crtc = obj_to_crtc(obj); ret = idr_alloc(leases, &drm_lease_idr_object, crtc->primary->base.id, crtc->primary->base.id + 1, GFP_KERNEL); if (ret < 0) { -- 2.30.2