child_device_obj->device cannot perform DMA properly if dma_set_mask()
returns non-zero. Add check for dma_set_mask() and return the error if it
fails. child_device_obj->device is not initialized here, so use kfree() to
free child_device_obj->device.

Fixes: 3a5469582c24 ("Drivers: hv: vmbus: Fix initialization of device object in vmbus_device_register()")
Signed-off-by: Haoxiang Li <make24@iscas.ac.cn>
---
 drivers/hv/vmbus_drv.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 12a707ab73f8..daa584eaa2af 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -1897,7 +1897,13 @@ int vmbus_device_register(struct hv_device *child_device_obj)
 
 	child_device_obj->device.dma_parms = &child_device_obj->dma_parms;
 	child_device_obj->device.dma_mask = &child_device_obj->dma_mask;
-	dma_set_mask(&child_device_obj->device, DMA_BIT_MASK(64));
+	ret = dma_set_mask(&child_device_obj->device, DMA_BIT_MASK(64));
+
+	if (ret) {
+		pr_err("64-bit DMA enable failed\n");
+		kfree(&child_device_obj->device);
+		return ret;
+	}
 
 	/*
 	 * Register with the LDM. This will kick off the driver/device
-- 
2.25.1

> child_device_obj->device cannot perform DMA properly if dma_set_mask()
> returns non-zero. …

Another wording suggestion:
  Direct memory access can not be properly performed any more
  after a dma_set_mask() call failed.


See also:
https://elixir.bootlin.com/linux/v6.10-rc6/source/kernel/dma/mapping.c#L804


>      … child_device_obj->device is not initialized here, so use kfree() to
> free child_device_obj->device.

How did you come to the conclusion that meaningful data processing
would still be possible according to such information?


…
> Signed-off-by: Haoxiang Li <make24@iscas.ac.cn>

I find it interesting that another personal name is presented here.
I noticed that some patches were published with the name “Ma Ke” previously.
How will requirements be resolved for the Developer's Certificate of Origin?
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.10-rc6#n398


Would you like to append parentheses to another function name in the summary phrase?

Regards,
Markus