[PATCH 04/52] drm: Set final_kfree in drm_dev_alloc

[Oleksandr Andrushchenko]

On 2/19/20 12:20 PM, Daniel Vetter wrote:
> I also did a full review of all callers, and only the xen driver
> forgot to call drm_dev_put in the failure path. Fix that up too.
>
> v2: I noticed that xen has a drm_driver.release hook, and uses
> drm_dev_alloc(). We need to remove the kfree from
> xen_drm_drv_release().
>
> bochs also has a release hook, but leaked the drm_device ever since
>
> commit 0a6659bdc5e8221da99eebb176fd9591435e38de
> Author: Gerd Hoffmann <kraxel at redhat.com>
> Date:   Tue Dec 17 18:04:46 2013 +0100
>
>      drm/bochs: new driver
>
> This patch here fixes that leak.
>
> Same for virtio, started leaking with
>
> commit b1df3a2b24a917f8853d43fe9683c0e360d2c33a
> Author: Gerd Hoffmann <kraxel at redhat.com>
> Date:   Tue Feb 11 14:58:04 2020 +0100
>
>      drm/virtio: add drm_driver.release callback.
>
> Cc: Gerd Hoffmann <kraxel at redhat.com>
> Cc: Oleksandr Andrushchenko <oleksandr_andrushchenko at epam.com>
> Cc: xen-devel at lists.xenproject.org
>
> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
Thank you,
Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko at epam.com>
> Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> Cc: Maxime Ripard <mripard at kernel.org>
> Cc: Thomas Zimmermann <tzimmermann at suse.de>
> Cc: David Airlie <airlied at linux.ie>
> Cc: Daniel Vetter <daniel at ffwll.ch>
> Cc: Oleksandr Andrushchenko <oleksandr_andrushchenko at epam.com>
> Cc: xen-devel at lists.xenproject.org
> ---
>   drivers/gpu/drm/drm_drv.c           | 3 +++
>   drivers/gpu/drm/xen/xen_drm_front.c | 2 +-
>   2 files changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> index 3e5627d6eba6..9e62e28bbc62 100644
> --- a/drivers/gpu/drm/drm_drv.c
> +++ b/drivers/gpu/drm/drm_drv.c
> @@ -39,6 +39,7 @@
>   #include <drm/drm_color_mgmt.h>
>   #include <drm/drm_drv.h>
>   #include <drm/drm_file.h>
> +#include <drm/drm_managed.h>
>   #include <drm/drm_mode_object.h>
>   #include <drm/drm_print.h>
>   
> @@ -819,6 +820,8 @@ struct drm_device *drm_dev_alloc(struct drm_driver *driver,
>   		return ERR_PTR(ret);
>   	}
>   
> +	drmm_add_final_kfree(dev, dev);
> +
>   	return dev;
>   }
>   EXPORT_SYMBOL(drm_dev_alloc);
> diff --git a/drivers/gpu/drm/xen/xen_drm_front.c b/drivers/gpu/drm/xen/xen_drm_front.c
> index 4be49c1aef51..d22b5da38935 100644
> --- a/drivers/gpu/drm/xen/xen_drm_front.c
> +++ b/drivers/gpu/drm/xen/xen_drm_front.c
> @@ -461,7 +461,6 @@ static void xen_drm_drv_release(struct drm_device *dev)
>   	drm_mode_config_cleanup(dev);
>   
>   	drm_dev_fini(dev);
> -	kfree(dev);
>   
>   	if (front_info->cfg.be_alloc)
>   		xenbus_switch_state(front_info->xb_dev,
> @@ -561,6 +560,7 @@ static int xen_drm_drv_init(struct xen_drm_front_info *front_info)
>   fail_modeset:
>   	drm_kms_helper_poll_fini(drm_dev);
>   	drm_mode_config_cleanup(drm_dev);
> +	drm_dev_put(drm_dev);
>   fail:
>   	kfree(drm_info);
>   	return ret;