| Message ID | 1662996766-19304-1-git-send-email-ssengar@linux.microsoft.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/hyperv: Don't overwrite dirt_needed value set by host | expand |
> From: Saurabh Sengar <ssengar@linux.microsoft.com> > Sent: Monday, September 12, 2022 8:33 AM > ... > Existing code is causing a race condition where dirt_needed value is > already set by the host and gets overwritten with default value. Remove > this default setting of dirt_needed, to avoid overwriting the value > received in the channel callback set by vmbus_open. Removing this > setting also means the default value for dirt_needed is changed to false > as it's allocated by kzalloc which is similar to legacy hyperv_fb driver. > > Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com> Reviewed-by: Dexuan Cui <decui@microsoft.com>
From: Saurabh Sengar <ssengar@linux.microsoft.com> Sent: Monday, September 12, 2022 8:33 AM > > Existing code is causing a race condition where dirt_needed value is > already set by the host and gets overwritten with default value. Remove > this default setting of dirt_needed, to avoid overwriting the value > received in the channel callback set by vmbus_open. Removing this > setting also means the default value for dirt_needed is changed to false > as it's allocated by kzalloc which is similar to legacy hyperv_fb driver. > > Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com> > --- > drivers/gpu/drm/hyperv/hyperv_drm_drv.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/drivers/gpu/drm/hyperv/hyperv_drm_drv.c > b/drivers/gpu/drm/hyperv/hyperv_drm_drv.c > index 4a8941fa0815..57d49a08b37f 100644 > --- a/drivers/gpu/drm/hyperv/hyperv_drm_drv.c > +++ b/drivers/gpu/drm/hyperv/hyperv_drm_drv.c > @@ -198,8 +198,6 @@ static int hyperv_vmbus_probe(struct hv_device *hdev, > if (ret) > drm_warn(dev, "Failed to update vram location.\n"); > > - hv->dirt_needed = true; > - > ret = hyperv_mode_config_init(hv); > if (ret) > goto err_vmbus_close; > -- > 2.31.1 Reviewed-by: Michael Kelley <mikelley@microsoft.com>
On Mon, Sep 12, 2022 at 08:32:46AM -0700, Saurabh Sengar wrote: > Existing code is causing a race condition where dirt_needed value is > already set by the host and gets overwritten with default value. Remove > this default setting of dirt_needed, to avoid overwriting the value > received in the channel callback set by vmbus_open. Removing this > setting also means the default value for dirt_needed is changed to false > as it's allocated by kzalloc which is similar to legacy hyperv_fb driver. > > Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com> Applied to hyperv-next. Thanks. I ended up reconstructing the patch myself since the said driver changed. It is only a one line change so that's fine. If the committed patch is wrong, please let me know.
diff --git a/drivers/gpu/drm/hyperv/hyperv_drm_drv.c b/drivers/gpu/drm/hyperv/hyperv_drm_drv.c index 4a8941fa0815..57d49a08b37f 100644 --- a/drivers/gpu/drm/hyperv/hyperv_drm_drv.c +++ b/drivers/gpu/drm/hyperv/hyperv_drm_drv.c @@ -198,8 +198,6 @@ static int hyperv_vmbus_probe(struct hv_device *hdev, if (ret) drm_warn(dev, "Failed to update vram location.\n"); - hv->dirt_needed = true; - ret = hyperv_mode_config_init(hv); if (ret) goto err_vmbus_close;
Existing code is causing a race condition where dirt_needed value is already set by the host and gets overwritten with default value. Remove this default setting of dirt_needed, to avoid overwriting the value received in the channel callback set by vmbus_open. Removing this setting also means the default value for dirt_needed is changed to false as it's allocated by kzalloc which is similar to legacy hyperv_fb driver. Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com> --- drivers/gpu/drm/hyperv/hyperv_drm_drv.c | 2 -- 1 file changed, 2 deletions(-)