[22/52] drm: Use drmm_ for drm_dev_init cleanup
diff mbox series

Message ID 20200219102122.1607365-23-daniel.vetter@ffwll.ch
State New
Headers show
Series
  • drm_device managed resources
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Commit Message

Daniel Vetter Feb. 19, 2020, 10:20 a.m. UTC
Well for the simple stuff at least, vblank, gem and minor cleanup I
want to further split up as a demonstration.

v2: We need to clear drm_device->dev otherwise the debug drm printing
after our cleanup hook (e.g. in drm_manged_release) will chase
released memory and result in a use-after-free. Not really pretty, but
oh well.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
---
 drivers/gpu/drm/drm_drv.c | 48 ++++++++++++++++++++-------------------
 1 file changed, 25 insertions(+), 23 deletions(-)

Comments

Laurent Pinchart Feb. 19, 2020, 2:35 p.m. UTC | #1
Hi Daniel,

Thank you for the patch.

On Wed, Feb 19, 2020 at 11:20:52AM +0100, Daniel Vetter wrote:
> Well for the simple stuff at least, vblank, gem and minor cleanup I
> want to further split up as a demonstration.
> 
> v2: We need to clear drm_device->dev otherwise the debug drm printing
> after our cleanup hook (e.g. in drm_manged_release) will chase
> released memory and result in a use-after-free. Not really pretty, but
> oh well.
> 
> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
> ---
>  drivers/gpu/drm/drm_drv.c | 48 ++++++++++++++++++++-------------------
>  1 file changed, 25 insertions(+), 23 deletions(-)

Is the managed API overhead, coupled with the fact that the code size
doesn't get reduced, worth it for core code ?

> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> index 782fd5d6f8b2..1f7ab88d9435 100644
> --- a/drivers/gpu/drm/drm_drv.c
> +++ b/drivers/gpu/drm/drm_drv.c
> @@ -580,6 +580,23 @@ static void drm_fs_inode_free(struct inode *inode)
>   *    used.
>   */
>  
> +static void drm_dev_init_release(struct drm_device *dev, void *res)
> +{
> +	drm_legacy_ctxbitmap_cleanup(dev);
> +	drm_legacy_remove_map_hash(dev);
> +	drm_fs_inode_free(dev->anon_inode);
> +
> +	put_device(dev->dev);
> +	/* Prevent use-after-free in drm_managed_release when debugging is
> +	 * enabled. Slightly awkward, but can't really be helped. */
> +	dev->dev = NULL;
> +	mutex_destroy(&dev->master_mutex);
> +	mutex_destroy(&dev->clientlist_mutex);
> +	mutex_destroy(&dev->filelist_mutex);
> +	mutex_destroy(&dev->struct_mutex);
> +	drm_legacy_destroy_members(dev);
> +}
> +
>  /**
>   * drm_dev_init - Initialise new DRM device
>   * @dev: DRM device
> @@ -647,11 +664,15 @@ int drm_dev_init(struct drm_device *dev,
>  	mutex_init(&dev->clientlist_mutex);
>  	mutex_init(&dev->master_mutex);
>  
> +	ret = drmm_add_action(dev, drm_dev_init_release, NULL);
> +	if (ret)
> +		return ret;
> +
>  	dev->anon_inode = drm_fs_inode_new();
>  	if (IS_ERR(dev->anon_inode)) {
>  		ret = PTR_ERR(dev->anon_inode);
>  		DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);
> -		goto err_free;
> +		goto err;
>  	}
>  
>  	if (drm_core_check_feature(dev, DRIVER_RENDER)) {
> @@ -688,19 +709,12 @@ int drm_dev_init(struct drm_device *dev,
>  	if (drm_core_check_feature(dev, DRIVER_GEM))
>  		drm_gem_destroy(dev);
>  err_ctxbitmap:
> -	drm_legacy_ctxbitmap_cleanup(dev);
> -	drm_legacy_remove_map_hash(dev);
>  err_minors:
>  	drm_minor_free(dev, DRM_MINOR_PRIMARY);
>  	drm_minor_free(dev, DRM_MINOR_RENDER);
> -	drm_fs_inode_free(dev->anon_inode);
> -err_free:
> -	put_device(dev->dev);
> -	mutex_destroy(&dev->master_mutex);
> -	mutex_destroy(&dev->clientlist_mutex);
> -	mutex_destroy(&dev->filelist_mutex);
> -	mutex_destroy(&dev->struct_mutex);
> -	drm_legacy_destroy_members(dev);
> +err:
> +	drm_managed_release(dev);
> +
>  	return ret;
>  }
>  EXPORT_SYMBOL(drm_dev_init);
> @@ -763,20 +777,8 @@ void drm_dev_fini(struct drm_device *dev)
>  	if (drm_core_check_feature(dev, DRIVER_GEM))
>  		drm_gem_destroy(dev);
>  
> -	drm_legacy_ctxbitmap_cleanup(dev);
> -	drm_legacy_remove_map_hash(dev);
> -	drm_fs_inode_free(dev->anon_inode);
> -
>  	drm_minor_free(dev, DRM_MINOR_PRIMARY);
>  	drm_minor_free(dev, DRM_MINOR_RENDER);
> -
> -	put_device(dev->dev);
> -
> -	mutex_destroy(&dev->master_mutex);
> -	mutex_destroy(&dev->clientlist_mutex);
> -	mutex_destroy(&dev->filelist_mutex);
> -	mutex_destroy(&dev->struct_mutex);
> -	drm_legacy_destroy_members(dev);
>  }
>  EXPORT_SYMBOL(drm_dev_fini);
>
Daniel Vetter Feb. 19, 2020, 3:27 p.m. UTC | #2
On Wed, Feb 19, 2020 at 3:35 PM Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
>
> Hi Daniel,
>
> Thank you for the patch.
>
> On Wed, Feb 19, 2020 at 11:20:52AM +0100, Daniel Vetter wrote:
> > Well for the simple stuff at least, vblank, gem and minor cleanup I
> > want to further split up as a demonstration.
> >
> > v2: We need to clear drm_device->dev otherwise the debug drm printing
> > after our cleanup hook (e.g. in drm_manged_release) will chase
> > released memory and result in a use-after-free. Not really pretty, but
> > oh well.
> >
> > Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
> > ---
> >  drivers/gpu/drm/drm_drv.c | 48 ++++++++++++++++++++-------------------
> >  1 file changed, 25 insertions(+), 23 deletions(-)
>
> Is the managed API overhead, coupled with the fact that the code size
> doesn't get reduced, worth it for core code ?

I've mostly done this as an example, to show how if you do this
consistently, you can drop a few if (is_it_set_up) checks and remove
the onion unwinding with lots of gotos. I do think it's worth it from
that pov, since long-term I want to get to a world where everything
related to drm_device gets unwound with drmm_ actions. The logging
output becomes fairly nice if you enable it :-)

But yeah stand-alone it's not a good pitch. Heck even the overall
patch series is still a net loss I think, simply because this is just
the bare minimum to get started.
-Daniel

> > diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> > index 782fd5d6f8b2..1f7ab88d9435 100644
> > --- a/drivers/gpu/drm/drm_drv.c
> > +++ b/drivers/gpu/drm/drm_drv.c
> > @@ -580,6 +580,23 @@ static void drm_fs_inode_free(struct inode *inode)
> >   *    used.
> >   */
> >
> > +static void drm_dev_init_release(struct drm_device *dev, void *res)
> > +{
> > +     drm_legacy_ctxbitmap_cleanup(dev);
> > +     drm_legacy_remove_map_hash(dev);
> > +     drm_fs_inode_free(dev->anon_inode);
> > +
> > +     put_device(dev->dev);
> > +     /* Prevent use-after-free in drm_managed_release when debugging is
> > +      * enabled. Slightly awkward, but can't really be helped. */
> > +     dev->dev = NULL;
> > +     mutex_destroy(&dev->master_mutex);
> > +     mutex_destroy(&dev->clientlist_mutex);
> > +     mutex_destroy(&dev->filelist_mutex);
> > +     mutex_destroy(&dev->struct_mutex);
> > +     drm_legacy_destroy_members(dev);
> > +}
> > +
> >  /**
> >   * drm_dev_init - Initialise new DRM device
> >   * @dev: DRM device
> > @@ -647,11 +664,15 @@ int drm_dev_init(struct drm_device *dev,
> >       mutex_init(&dev->clientlist_mutex);
> >       mutex_init(&dev->master_mutex);
> >
> > +     ret = drmm_add_action(dev, drm_dev_init_release, NULL);
> > +     if (ret)
> > +             return ret;
> > +
> >       dev->anon_inode = drm_fs_inode_new();
> >       if (IS_ERR(dev->anon_inode)) {
> >               ret = PTR_ERR(dev->anon_inode);
> >               DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);
> > -             goto err_free;
> > +             goto err;
> >       }
> >
> >       if (drm_core_check_feature(dev, DRIVER_RENDER)) {
> > @@ -688,19 +709,12 @@ int drm_dev_init(struct drm_device *dev,
> >       if (drm_core_check_feature(dev, DRIVER_GEM))
> >               drm_gem_destroy(dev);
> >  err_ctxbitmap:
> > -     drm_legacy_ctxbitmap_cleanup(dev);
> > -     drm_legacy_remove_map_hash(dev);
> >  err_minors:
> >       drm_minor_free(dev, DRM_MINOR_PRIMARY);
> >       drm_minor_free(dev, DRM_MINOR_RENDER);
> > -     drm_fs_inode_free(dev->anon_inode);
> > -err_free:
> > -     put_device(dev->dev);
> > -     mutex_destroy(&dev->master_mutex);
> > -     mutex_destroy(&dev->clientlist_mutex);
> > -     mutex_destroy(&dev->filelist_mutex);
> > -     mutex_destroy(&dev->struct_mutex);
> > -     drm_legacy_destroy_members(dev);
> > +err:
> > +     drm_managed_release(dev);
> > +
> >       return ret;
> >  }
> >  EXPORT_SYMBOL(drm_dev_init);
> > @@ -763,20 +777,8 @@ void drm_dev_fini(struct drm_device *dev)
> >       if (drm_core_check_feature(dev, DRIVER_GEM))
> >               drm_gem_destroy(dev);
> >
> > -     drm_legacy_ctxbitmap_cleanup(dev);
> > -     drm_legacy_remove_map_hash(dev);
> > -     drm_fs_inode_free(dev->anon_inode);
> > -
> >       drm_minor_free(dev, DRM_MINOR_PRIMARY);
> >       drm_minor_free(dev, DRM_MINOR_RENDER);
> > -
> > -     put_device(dev->dev);
> > -
> > -     mutex_destroy(&dev->master_mutex);
> > -     mutex_destroy(&dev->clientlist_mutex);
> > -     mutex_destroy(&dev->filelist_mutex);
> > -     mutex_destroy(&dev->struct_mutex);
> > -     drm_legacy_destroy_members(dev);
> >  }
> >  EXPORT_SYMBOL(drm_dev_fini);
> >
>
> --
> Regards,
>
> Laurent Pinchart
Laurent Pinchart Feb. 19, 2020, 3:37 p.m. UTC | #3
Hi Daniel,

On Wed, Feb 19, 2020 at 04:27:57PM +0100, Daniel Vetter wrote:
> On Wed, Feb 19, 2020 at 3:35 PM Laurent Pinchart wrote:
> > On Wed, Feb 19, 2020 at 11:20:52AM +0100, Daniel Vetter wrote:
> > > Well for the simple stuff at least, vblank, gem and minor cleanup I
> > > want to further split up as a demonstration.
> > >
> > > v2: We need to clear drm_device->dev otherwise the debug drm printing
> > > after our cleanup hook (e.g. in drm_manged_release) will chase
> > > released memory and result in a use-after-free. Not really pretty, but
> > > oh well.
> > >
> > > Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
> > > ---
> > >  drivers/gpu/drm/drm_drv.c | 48 ++++++++++++++++++++-------------------
> > >  1 file changed, 25 insertions(+), 23 deletions(-)
> >
> > Is the managed API overhead, coupled with the fact that the code size
> > doesn't get reduced, worth it for core code ?
> 
> I've mostly done this as an example, to show how if you do this
> consistently, you can drop a few if (is_it_set_up) checks and remove
> the onion unwinding with lots of gotos.

That's however more a matter of making the cleanup handlers idempotent
than using a managed API, isn't it ?

> I do think it's worth it from
> that pov, since long-term I want to get to a world where everything
> related to drm_device gets unwound with drmm_ actions. The logging
> output becomes fairly nice if you enable it :-)
> 
> But yeah stand-alone it's not a good pitch. Heck even the overall
> patch series is still a net loss I think, simply because this is just
> the bare minimum to get started.
> -Daniel
> 
> > > diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> > > index 782fd5d6f8b2..1f7ab88d9435 100644
> > > --- a/drivers/gpu/drm/drm_drv.c
> > > +++ b/drivers/gpu/drm/drm_drv.c
> > > @@ -580,6 +580,23 @@ static void drm_fs_inode_free(struct inode *inode)
> > >   *    used.
> > >   */
> > >
> > > +static void drm_dev_init_release(struct drm_device *dev, void *res)
> > > +{
> > > +     drm_legacy_ctxbitmap_cleanup(dev);
> > > +     drm_legacy_remove_map_hash(dev);
> > > +     drm_fs_inode_free(dev->anon_inode);
> > > +
> > > +     put_device(dev->dev);
> > > +     /* Prevent use-after-free in drm_managed_release when debugging is
> > > +      * enabled. Slightly awkward, but can't really be helped. */
> > > +     dev->dev = NULL;
> > > +     mutex_destroy(&dev->master_mutex);
> > > +     mutex_destroy(&dev->clientlist_mutex);
> > > +     mutex_destroy(&dev->filelist_mutex);
> > > +     mutex_destroy(&dev->struct_mutex);
> > > +     drm_legacy_destroy_members(dev);
> > > +}
> > > +
> > >  /**
> > >   * drm_dev_init - Initialise new DRM device
> > >   * @dev: DRM device
> > > @@ -647,11 +664,15 @@ int drm_dev_init(struct drm_device *dev,
> > >       mutex_init(&dev->clientlist_mutex);
> > >       mutex_init(&dev->master_mutex);
> > >
> > > +     ret = drmm_add_action(dev, drm_dev_init_release, NULL);
> > > +     if (ret)
> > > +             return ret;
> > > +
> > >       dev->anon_inode = drm_fs_inode_new();
> > >       if (IS_ERR(dev->anon_inode)) {
> > >               ret = PTR_ERR(dev->anon_inode);
> > >               DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);
> > > -             goto err_free;
> > > +             goto err;
> > >       }
> > >
> > >       if (drm_core_check_feature(dev, DRIVER_RENDER)) {
> > > @@ -688,19 +709,12 @@ int drm_dev_init(struct drm_device *dev,
> > >       if (drm_core_check_feature(dev, DRIVER_GEM))
> > >               drm_gem_destroy(dev);
> > >  err_ctxbitmap:
> > > -     drm_legacy_ctxbitmap_cleanup(dev);
> > > -     drm_legacy_remove_map_hash(dev);
> > >  err_minors:
> > >       drm_minor_free(dev, DRM_MINOR_PRIMARY);
> > >       drm_minor_free(dev, DRM_MINOR_RENDER);
> > > -     drm_fs_inode_free(dev->anon_inode);
> > > -err_free:
> > > -     put_device(dev->dev);
> > > -     mutex_destroy(&dev->master_mutex);
> > > -     mutex_destroy(&dev->clientlist_mutex);
> > > -     mutex_destroy(&dev->filelist_mutex);
> > > -     mutex_destroy(&dev->struct_mutex);
> > > -     drm_legacy_destroy_members(dev);
> > > +err:
> > > +     drm_managed_release(dev);
> > > +
> > >       return ret;
> > >  }
> > >  EXPORT_SYMBOL(drm_dev_init);
> > > @@ -763,20 +777,8 @@ void drm_dev_fini(struct drm_device *dev)
> > >       if (drm_core_check_feature(dev, DRIVER_GEM))
> > >               drm_gem_destroy(dev);
> > >
> > > -     drm_legacy_ctxbitmap_cleanup(dev);
> > > -     drm_legacy_remove_map_hash(dev);
> > > -     drm_fs_inode_free(dev->anon_inode);
> > > -
> > >       drm_minor_free(dev, DRM_MINOR_PRIMARY);
> > >       drm_minor_free(dev, DRM_MINOR_RENDER);
> > > -
> > > -     put_device(dev->dev);
> > > -
> > > -     mutex_destroy(&dev->master_mutex);
> > > -     mutex_destroy(&dev->clientlist_mutex);
> > > -     mutex_destroy(&dev->filelist_mutex);
> > > -     mutex_destroy(&dev->struct_mutex);
> > > -     drm_legacy_destroy_members(dev);
> > >  }
> > >  EXPORT_SYMBOL(drm_dev_fini);
> > >
Daniel Vetter Feb. 19, 2020, 3:44 p.m. UTC | #4
On Wed, Feb 19, 2020 at 4:38 PM Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
>
> Hi Daniel,
>
> On Wed, Feb 19, 2020 at 04:27:57PM +0100, Daniel Vetter wrote:
> > On Wed, Feb 19, 2020 at 3:35 PM Laurent Pinchart wrote:
> > > On Wed, Feb 19, 2020 at 11:20:52AM +0100, Daniel Vetter wrote:
> > > > Well for the simple stuff at least, vblank, gem and minor cleanup I
> > > > want to further split up as a demonstration.
> > > >
> > > > v2: We need to clear drm_device->dev otherwise the debug drm printing
> > > > after our cleanup hook (e.g. in drm_manged_release) will chase
> > > > released memory and result in a use-after-free. Not really pretty, but
> > > > oh well.
> > > >
> > > > Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
> > > > ---
> > > >  drivers/gpu/drm/drm_drv.c | 48 ++++++++++++++++++++-------------------
> > > >  1 file changed, 25 insertions(+), 23 deletions(-)
> > >
> > > Is the managed API overhead, coupled with the fact that the code size
> > > doesn't get reduced, worth it for core code ?
> >
> > I've mostly done this as an example, to show how if you do this
> > consistently, you can drop a few if (is_it_set_up) checks and remove
> > the onion unwinding with lots of gotos.
>
> That's however more a matter of making the cleanup handlers idempotent
> than using a managed API, isn't it ?

With the managed api you can drop the if (is_it_set_up/allocated)
checks since you no longer need them to be idempotent for simpler code
flow. That's at least the point I've tried to make with this patch.
-Daniel

> > I do think it's worth it from
> > that pov, since long-term I want to get to a world where everything
> > related to drm_device gets unwound with drmm_ actions. The logging
> > output becomes fairly nice if you enable it :-)
> >
> > But yeah stand-alone it's not a good pitch. Heck even the overall
> > patch series is still a net loss I think, simply because this is just
> > the bare minimum to get started.
> > -Daniel
> >
> > > > diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> > > > index 782fd5d6f8b2..1f7ab88d9435 100644
> > > > --- a/drivers/gpu/drm/drm_drv.c
> > > > +++ b/drivers/gpu/drm/drm_drv.c
> > > > @@ -580,6 +580,23 @@ static void drm_fs_inode_free(struct inode *inode)
> > > >   *    used.
> > > >   */
> > > >
> > > > +static void drm_dev_init_release(struct drm_device *dev, void *res)
> > > > +{
> > > > +     drm_legacy_ctxbitmap_cleanup(dev);
> > > > +     drm_legacy_remove_map_hash(dev);
> > > > +     drm_fs_inode_free(dev->anon_inode);
> > > > +
> > > > +     put_device(dev->dev);
> > > > +     /* Prevent use-after-free in drm_managed_release when debugging is
> > > > +      * enabled. Slightly awkward, but can't really be helped. */
> > > > +     dev->dev = NULL;
> > > > +     mutex_destroy(&dev->master_mutex);
> > > > +     mutex_destroy(&dev->clientlist_mutex);
> > > > +     mutex_destroy(&dev->filelist_mutex);
> > > > +     mutex_destroy(&dev->struct_mutex);
> > > > +     drm_legacy_destroy_members(dev);
> > > > +}
> > > > +
> > > >  /**
> > > >   * drm_dev_init - Initialise new DRM device
> > > >   * @dev: DRM device
> > > > @@ -647,11 +664,15 @@ int drm_dev_init(struct drm_device *dev,
> > > >       mutex_init(&dev->clientlist_mutex);
> > > >       mutex_init(&dev->master_mutex);
> > > >
> > > > +     ret = drmm_add_action(dev, drm_dev_init_release, NULL);
> > > > +     if (ret)
> > > > +             return ret;
> > > > +
> > > >       dev->anon_inode = drm_fs_inode_new();
> > > >       if (IS_ERR(dev->anon_inode)) {
> > > >               ret = PTR_ERR(dev->anon_inode);
> > > >               DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);
> > > > -             goto err_free;
> > > > +             goto err;
> > > >       }
> > > >
> > > >       if (drm_core_check_feature(dev, DRIVER_RENDER)) {
> > > > @@ -688,19 +709,12 @@ int drm_dev_init(struct drm_device *dev,
> > > >       if (drm_core_check_feature(dev, DRIVER_GEM))
> > > >               drm_gem_destroy(dev);
> > > >  err_ctxbitmap:
> > > > -     drm_legacy_ctxbitmap_cleanup(dev);
> > > > -     drm_legacy_remove_map_hash(dev);
> > > >  err_minors:
> > > >       drm_minor_free(dev, DRM_MINOR_PRIMARY);
> > > >       drm_minor_free(dev, DRM_MINOR_RENDER);
> > > > -     drm_fs_inode_free(dev->anon_inode);
> > > > -err_free:
> > > > -     put_device(dev->dev);
> > > > -     mutex_destroy(&dev->master_mutex);
> > > > -     mutex_destroy(&dev->clientlist_mutex);
> > > > -     mutex_destroy(&dev->filelist_mutex);
> > > > -     mutex_destroy(&dev->struct_mutex);
> > > > -     drm_legacy_destroy_members(dev);
> > > > +err:
> > > > +     drm_managed_release(dev);
> > > > +
> > > >       return ret;
> > > >  }
> > > >  EXPORT_SYMBOL(drm_dev_init);
> > > > @@ -763,20 +777,8 @@ void drm_dev_fini(struct drm_device *dev)
> > > >       if (drm_core_check_feature(dev, DRIVER_GEM))
> > > >               drm_gem_destroy(dev);
> > > >
> > > > -     drm_legacy_ctxbitmap_cleanup(dev);
> > > > -     drm_legacy_remove_map_hash(dev);
> > > > -     drm_fs_inode_free(dev->anon_inode);
> > > > -
> > > >       drm_minor_free(dev, DRM_MINOR_PRIMARY);
> > > >       drm_minor_free(dev, DRM_MINOR_RENDER);
> > > > -
> > > > -     put_device(dev->dev);
> > > > -
> > > > -     mutex_destroy(&dev->master_mutex);
> > > > -     mutex_destroy(&dev->clientlist_mutex);
> > > > -     mutex_destroy(&dev->filelist_mutex);
> > > > -     mutex_destroy(&dev->struct_mutex);
> > > > -     drm_legacy_destroy_members(dev);
> > > >  }
> > > >  EXPORT_SYMBOL(drm_dev_fini);
> > > >
>
> --
> Regards,
>
> Laurent Pinchart

Patch
diff mbox series

diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 782fd5d6f8b2..1f7ab88d9435 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -580,6 +580,23 @@  static void drm_fs_inode_free(struct inode *inode)
  *    used.
  */
 
+static void drm_dev_init_release(struct drm_device *dev, void *res)
+{
+	drm_legacy_ctxbitmap_cleanup(dev);
+	drm_legacy_remove_map_hash(dev);
+	drm_fs_inode_free(dev->anon_inode);
+
+	put_device(dev->dev);
+	/* Prevent use-after-free in drm_managed_release when debugging is
+	 * enabled. Slightly awkward, but can't really be helped. */
+	dev->dev = NULL;
+	mutex_destroy(&dev->master_mutex);
+	mutex_destroy(&dev->clientlist_mutex);
+	mutex_destroy(&dev->filelist_mutex);
+	mutex_destroy(&dev->struct_mutex);
+	drm_legacy_destroy_members(dev);
+}
+
 /**
  * drm_dev_init - Initialise new DRM device
  * @dev: DRM device
@@ -647,11 +664,15 @@  int drm_dev_init(struct drm_device *dev,
 	mutex_init(&dev->clientlist_mutex);
 	mutex_init(&dev->master_mutex);
 
+	ret = drmm_add_action(dev, drm_dev_init_release, NULL);
+	if (ret)
+		return ret;
+
 	dev->anon_inode = drm_fs_inode_new();
 	if (IS_ERR(dev->anon_inode)) {
 		ret = PTR_ERR(dev->anon_inode);
 		DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);
-		goto err_free;
+		goto err;
 	}
 
 	if (drm_core_check_feature(dev, DRIVER_RENDER)) {
@@ -688,19 +709,12 @@  int drm_dev_init(struct drm_device *dev,
 	if (drm_core_check_feature(dev, DRIVER_GEM))
 		drm_gem_destroy(dev);
 err_ctxbitmap:
-	drm_legacy_ctxbitmap_cleanup(dev);
-	drm_legacy_remove_map_hash(dev);
 err_minors:
 	drm_minor_free(dev, DRM_MINOR_PRIMARY);
 	drm_minor_free(dev, DRM_MINOR_RENDER);
-	drm_fs_inode_free(dev->anon_inode);
-err_free:
-	put_device(dev->dev);
-	mutex_destroy(&dev->master_mutex);
-	mutex_destroy(&dev->clientlist_mutex);
-	mutex_destroy(&dev->filelist_mutex);
-	mutex_destroy(&dev->struct_mutex);
-	drm_legacy_destroy_members(dev);
+err:
+	drm_managed_release(dev);
+
 	return ret;
 }
 EXPORT_SYMBOL(drm_dev_init);
@@ -763,20 +777,8 @@  void drm_dev_fini(struct drm_device *dev)
 	if (drm_core_check_feature(dev, DRIVER_GEM))
 		drm_gem_destroy(dev);
 
-	drm_legacy_ctxbitmap_cleanup(dev);
-	drm_legacy_remove_map_hash(dev);
-	drm_fs_inode_free(dev->anon_inode);
-
 	drm_minor_free(dev, DRM_MINOR_PRIMARY);
 	drm_minor_free(dev, DRM_MINOR_RENDER);
-
-	put_device(dev->dev);
-
-	mutex_destroy(&dev->master_mutex);
-	mutex_destroy(&dev->clientlist_mutex);
-	mutex_destroy(&dev->filelist_mutex);
-	mutex_destroy(&dev->struct_mutex);
-	drm_legacy_destroy_members(dev);
 }
 EXPORT_SYMBOL(drm_dev_fini);