From: Nicolin Chen nicolinc@nvidia.com Sent: Friday, July 28, 2023 12:37 PM
On Fri, Jul 28, 2023 at 04:23:03AM +0000, Tian, Kevin wrote:
From: Nicolin Chen nicolinc@nvidia.com Sent: Friday, July 28, 2023 4:25 AM
+static int iommufd_access_change_ioas(struct iommufd_access *access,
struct iommufd_ioas *new_ioas)+{
u32 iopt_access_list_id = access->iopt_access_list_id;struct iommufd_ioas *cur_ioas = access->ioas;int rc;lockdep_assert_held(&access->ioas_lock);/* We are racing with a concurrent detach, bail */if (cur_ioas != access->ioas_unpin)return -EBUSY;if (IS_ERR(new_ioas))return PTR_ERR(new_ioas);iommufd_access_change_ioas_id() already checks errors.
I've thought about that: given that iommufd_access_change_ioas is a standalone API, though it's not used anywhere else at the moment, it might be safer to have this check again. Otherwise, we would need a line of comments saying that "caller must make sure that the input new_ioas is not holding an error code" or so?
I don't think it's a common practice for the caller to pass in an error pointer when it already knows it's an error...