Yi Liu <yi.l.liu@xxxxxxxxx> writes: [...] > +static int vfio_get_devicefd(const char *sysfs_path, Error **errp) > +{ > + long int ret = -ENOTTY; > + char *path, *vfio_dev_path = NULL, *vfio_path = NULL; > + DIR *dir; > + struct dirent *dent; > + gchar *contents; > + struct stat st; > + gsize length; > + int major, minor; > + dev_t vfio_devt; > + > + path = g_strdup_printf("%s/vfio-device", sysfs_path); > + if (stat(path, &st) < 0) { > + error_setg_errno(errp, errno, "no such host device"); > + goto out_free_path; > + } > + > + dir = opendir(path); > + if (!dir) { > + error_setg_errno(errp, errno, "couldn't open dirrectory %s", path); > + goto out_free_path; > + } > + > + while ((dent = readdir(dir))) { > + if (!strncmp(dent->d_name, "vfio", 4)) { > + vfio_dev_path = g_strdup_printf("%s/%s/dev", path, dent->d_name); > + break; > + } > + } > + > + if (!vfio_dev_path) { > + error_setg(errp, "failed to find vfio-device/vfioX/dev"); > + goto out_free_path; > + } > + > + if (!g_file_get_contents(vfio_dev_path, &contents, &length, NULL)) { > + error_setg(errp, "failed to load \"%s\"", vfio_dev_path); > + goto out_free_dev_path; > + } > + > + if (sscanf(contents, "%d:%d", &major, &minor) != 2) { > + error_setg(errp, "failed to get major:mino for \"%s\"", vfio_dev_path); > + goto out_free_dev_path; > + } > + g_free(contents); > + vfio_devt = makedev(major, minor); > + > + vfio_path = g_strdup_printf("/dev/vfio/devices/%s", dent->d_name); > + ret = open_cdev(vfio_path, vfio_devt); > + if (ret < 0) { > + error_setg(errp, "Failed to open %s", vfio_path); > + } > + > + trace_vfio_iommufd_get_devicefd(vfio_path, ret); > + g_free(vfio_path); > + > +out_free_dev_path: > + g_free(vfio_dev_path); > +out_free_path: > + g_free(path); > + > + if (*errp) { > + error_prepend(errp, VFIO_MSG_PREFIX, path); I ran into this while trying to get things running, so haven't reviewed the patch but noticed path is used after it's freed if !!*errp. - Alistair > + } > + return ret; > +}