2021-06-17 10:03:39

by Qiang Ma

Subject: [PATCH] drm/auth: Move master pointer from drm_device to drm_file

The drm_file pointer clears to zero during multi-user switching,
so it needs to call drm_new_set_master for master pointer from drm_file.

Signed-off-by: Qiang Ma <[email protected]>
---
drivers/gpu/drm/drm_auth.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_auth.c b/drivers/gpu/drm/drm_auth.c
index f2d46b7ac6f9..02431af6d0c5 100644
--- a/drivers/gpu/drm/drm_auth.c
+++ b/drivers/gpu/drm/drm_auth.c
@@ -302,7 +302,7 @@ int drm_master_open(struct drm_file *file_priv)
/* if there is no current master make this fd it, but do not create
* any master object for render clients */
mutex_lock(&dev->master_mutex);
- if (!dev->master)
+ if (!file_priv->master)
ret = drm_new_set_master(dev, file_priv);
else
file_priv->master = drm_master_get(dev->master);
--
2.20.1

2021-06-17 20:52:14

by Daniel Vetter

Subject: Re: [PATCH] drm/auth: Move master pointer from drm_device to drm_file

On Thu, Jun 17, 2021 at 05:47:33PM +0800, Qiang Ma wrote:
> The drm_file pointer clears to zero during multi-user switching,
> so it needs to call drm_new_set_master for master pointer from drm_file.

That sounds like a bug. drm_file->master should be always the same -
either you become a new stand-alone thing, our you get linked to the
current master.

Or I'm completely missing what you're trying to fix here.
-Daniel

>
> Signed-off-by: Qiang Ma <[email protected]>
> ---
> drivers/gpu/drm/drm_auth.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_auth.c b/drivers/gpu/drm/drm_auth.c
> index f2d46b7ac6f9..02431af6d0c5 100644
> --- a/drivers/gpu/drm/drm_auth.c
> +++ b/drivers/gpu/drm/drm_auth.c
> @@ -302,7 +302,7 @@ int drm_master_open(struct drm_file *file_priv)
> /* if there is no current master make this fd it, but do not create
> * any master object for render clients */
> mutex_lock(&dev->master_mutex);
> - if (!dev->master)
> + if (!file_priv->master)
> ret = drm_new_set_master(dev, file_priv);
> else
> file_priv->master = drm_master_get(dev->master);
> --
> 2.20.1
>
>
>

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