[RESEND] amdkfd: check ret code for ioctls

[Zhu Lingshan]

The ioctl functions may fail, causing the args unreliable.
Therefore, the args should not be copied to user space.

The return code provides enough information for
error handling in user space.

This commit checks the return code of the ioctl functions
and handles errors appropriately when they fail.

Signed-off-by: Zhu Lingshan <lingshan.zhu at amd.com>
---
 drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
index 3e6b4736a7fe..a184ca0023b5 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
@@ -3327,6 +3327,8 @@ static long kfd_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
 	}
 
 	retcode = func(filep, process, kdata);
+	if (retcode)
+		goto err_retcode;
 
 	if (cmd & IOC_OUT)
 		if (copy_to_user((void __user *)arg, kdata, usize) != 0)
@@ -3340,6 +3342,7 @@ static long kfd_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
 	if (kdata != stack_kdata)
 		kfree(kdata);
 
+err_retcode:
 	if (retcode)
 		dev_dbg(kfd_device, "ioctl cmd (#0x%x), arg 0x%lx, ret = %d\n",
 				nr, arg, retcode);
-- 
2.43.5