On Wed, Jun 17, 2020 at 10:45:46AM +0300, Yishai Hadas wrote:
> +static struct ibv_context *verbs_import_device(int cmd_fd)
> +{
> + struct verbs_device *verbs_device = NULL;
> + struct verbs_context *context_ex;
> + struct ibv_device **dev_list;
> + struct ibv_context *ctx = NULL;
> + struct stat st;
> + int i;
> +
> + if (fstat(cmd_fd, &st) || !S_ISCHR(st.st_mode)) {
> + errno = EINVAL;
> + return NULL;
> + }
> +
> + dev_list = ibv_get_device_list(NULL);
> + if (!dev_list) {
> + errno = ENODEV;
> + return NULL;
> + }
> +
> + for (i = 0; dev_list[i]; ++i) {
> + if (verbs_get_device(dev_list[i])->sysfs->sysfs_cdev ==
> + st.st_rdev) {
> + verbs_device = verbs_get_device(dev_list[i]);
> + break;
> + }
> + }
Unfortunately it looks like there is a small race here, the struct
ib_uverbs_file can exist beyond the lifetime of the cdev number - the
uverbs_ida is freed in ib_uverbs_remove_one() and files can still be
open past that point.
I guess we should add a special ioctl to return the driver_id and
match that way?
> + if (!verbs_device) {
> + errno = ENODEV;
> + goto out;
> + }
> +
> + if (!verbs_device->ops->import_context) {
> + errno = EOPNOTSUPP;
> + goto out;
> + }
> +
> + context_ex = verbs_device->ops->import_context(&verbs_device->device, cmd_fd);
> + if (!context_ex)
> + goto out;
> +
> + set_lib_ops(context_ex);
> +
> + ctx = &context_ex->context;
> +out:
> + ibv_free_device_list(dev_list);
> + return ctx;
> +}
> +
> +struct ibv_context *ibv_import_device(int cmd_fd)
> +{
> + return verbs_import_device(cmd_fd);
> +}
Why two functions? No reason for verbs_import_device()..
Jason
