Re: [PATCH 04/51] drm: Set final_kfree in drm_dev_alloc

[Daniel Vetter <daniel@ffwll.ch>]

On Sat, Mar 07, 2020 at 09:06:08AM +0100, Sam Ravnborg wrote:
> On Mon, Mar 02, 2020 at 11:25:44PM +0100, 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.
> 
> So ~40 callers - phew..
> 
> > 
> > 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@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@redhat.com>
> > Date:   Tue Feb 11 14:58:04 2020 +0100
> > 
> >     drm/virtio: add drm_driver.release callback.
> > 
> > Cc: Gerd Hoffmann <kraxel@redhat.com>
> > Cc: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
> > Cc: xen-devel@lists.xenproject.org
> 
> The above will be picked up by tools as regular Cc: lines.
> But I guess it is fine.

That was the idea, I've deleted the spurious blank line to make this less
confusing.
-Daniel

> 
> > 
> > Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
> > Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
> > Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> > Cc: Maxime Ripard <mripard@kernel.org>
> > Cc: Thomas Zimmermann <tzimmermann@suse.de>
> > Cc: David Airlie <airlied@linux.ie>
> > Cc: Daniel Vetter <daniel@ffwll.ch>
> > Cc: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
> > Cc: xen-devel@lists.xenproject.org
> 
> For the drivers I looked at everything looked fine.
> 
> Acked-by: Sam Ravnborg <sam@ravnborg.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 153050fc926c..7b84ee8a5eb5 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;
> > -- 
> > 2.24.1
> > 
> > _______________________________________________
> > dri-devel mailing list
> > dri-devel@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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