From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Vetter Subject: Re: [PATCH 1/2] drm: Make control nodes master-less Date: Tue, 4 Mar 2014 09:27:30 +0100 Message-ID: <20140304082730.GL17001@phenom.ffwll.local> References: <1392817242-15889-1-git-send-email-thellstrom@vmware.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-ee0-f42.google.com (mail-ee0-f42.google.com [74.125.83.42]) by gabe.freedesktop.org (Postfix) with ESMTP id 29830FB3F3 for ; Tue, 4 Mar 2014 00:27:36 -0800 (PST) Received: by mail-ee0-f42.google.com with SMTP id d17so4582456eek.15 for ; Tue, 04 Mar 2014 00:27:35 -0800 (PST) Content-Disposition: inline In-Reply-To: <1392817242-15889-1-git-send-email-thellstrom@vmware.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dri-devel-bounces@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org To: Thomas Hellstrom Cc: airlied@redhat.com, linux-graphics-maintainer@vmware.com, dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org On Wed, Feb 19, 2014 at 02:40:41PM +0100, Thomas Hellstrom wrote: > Like for render-nodes, there is no point in maintaining the master concept > for control nodes, so set the struct drm_file::master pointer to NULL. > > At the same time, make sure DRM_MASTER | DRM_CONTROL_ALLOW ioctls are always > allowed when called through the control node. Previously the caller also > needed to be master. > > Signed-off-by: Thomas Hellstrom > --- > drivers/gpu/drm/drm_drv.c | 5 +++-- > drivers/gpu/drm/drm_fops.c | 5 +++-- > include/drm/drmP.h | 5 +++++ > 3 files changed, 11 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c > index 345be03..42af8bd 100644 > --- a/drivers/gpu/drm/drm_drv.c > +++ b/drivers/gpu/drm/drm_drv.c > @@ -355,8 +355,9 @@ long drm_ioctl(struct file *filp, > retcode = -EINVAL; > } else if (((ioctl->flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)) || > ((ioctl->flags & DRM_AUTH) && !drm_is_render_client(file_priv) && !file_priv->authenticated) || > - ((ioctl->flags & DRM_MASTER) && !file_priv->is_master) || > - (!(ioctl->flags & DRM_CONTROL_ALLOW) && (file_priv->minor->type == DRM_MINOR_CONTROL)) || > + (((ioctl->flags & DRM_MASTER) && !file_priv->is_master) && > + !(drm_is_control(file_priv) && (ioctl->flags & DRM_CONTROL_ALLOW))) || > + (!(ioctl->flags & DRM_CONTROL_ALLOW) && drm_is_control(file_priv)) || > (!(ioctl->flags & DRM_RENDER_ALLOW) && drm_is_render_client(file_priv))) { This is hideous to review ;-) I think it would be really good to extract this entire condition into a drm_check_ioctl_acces(ioctl, file_priv) helper and untangle all the different cases a bit by splitting it up into if checks with individual return false/true; statements. With that bit of polish for the next reviewer's sanity applied both patches are Reviewed-by: Daniel Vetter I guess with this change we could move the master pointer from drm_minor to drm_device, which would make it really clear that there's only ever one master per device. But that's one giant sed job, so meh ;-) One thing I'm unsure about is whether we want/need to have the master concept on the control node, too. logind uses set/dropmaster as a kms-specific revoke support, so if we ever want to switch to using control nodes for display servers we'd need to shuffle this a bit again. Otoh no one is using control nodes for real afaik, so we likely need some interface polishing anyway. And for non-root display servers we can block out all the awful legacy drm ioctls easily, so just keeping on using legacy nodes isn't a security issue for that use-case. Cheers, Daniel > retcode = -EACCES; > } else { > diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c > index 7f2af9a..08a3196 100644 > --- a/drivers/gpu/drm/drm_fops.c > +++ b/drivers/gpu/drm/drm_fops.c > @@ -259,7 +259,8 @@ static int drm_open_helper(struct inode *inode, struct file *filp, > /* if there is no current master make this fd it, but do not create > * any master object for render clients */ > mutex_lock(&dev->struct_mutex); > - if (!priv->minor->master && !drm_is_render_client(priv)) { > + if (!priv->minor->master && !drm_is_render_client(priv) && > + !drm_is_control(priv)) { > /* create a new master */ > priv->minor->master = drm_master_create(priv->minor); > if (!priv->minor->master) { > @@ -297,7 +298,7 @@ static int drm_open_helper(struct inode *inode, struct file *filp, > goto out_close; > } > } > - } else if (!drm_is_render_client(priv)) { > + } else if (!drm_is_render_client(priv) && !drm_is_control(priv)) { > /* get a reference to the master */ > priv->master = drm_master_get(priv->minor->master); > } > diff --git a/include/drm/drmP.h b/include/drm/drmP.h > index 04a7f31..ff68e26 100644 > --- a/include/drm/drmP.h > +++ b/include/drm/drmP.h > @@ -1246,6 +1246,11 @@ static inline bool drm_is_render_client(struct drm_file *file_priv) > return file_priv->minor->type == DRM_MINOR_RENDER; > } > > +static inline bool drm_is_control(struct drm_file *file_priv) > +{ > + return file_priv->minor->type == DRM_MINOR_CONTROL; > +} > + > /******************************************************************/ > /** \name Internal function definitions */ > /*@{*/ > -- > 1.7.10.4 > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/dri-devel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch