On 11/03/2024 04.38, Zhao Liu wrote:
From: Zhao Liu <zhao1....@intel.com>As the comment in qapi/error, passing @errp to error_prepend() requires ERRP_GUARD(): * = Why, when and how to use ERRP_GUARD() = * * Without ERRP_GUARD(), use of the @errp parameter is restricted: ... * - It should not be passed to error_prepend(), error_vprepend() or * error_append_hint(), because that doesn't work with &error_fatal. * ERRP_GUARD() lifts these restrictions. * * To use ERRP_GUARD(), add it right at the beginning of the function. * @errp can then be used without worrying about the argument being * NULL or &error_fatal. ERRP_GUARD() could avoid the case when @errp is &error_fatal, the user can't see this additional information, because exit() happens in error_setg earlier than information is added [1]. In hw/virtio/vhost.c, there are 2 functions passing @errp to error_prepend() without ERRP_GUARD(): - vhost_save_backend_state() - vhost_load_backend_state() Their @errp both points to callers' @local_err. However, as the APIs defined in include/hw/virtio/vhost.h, it is necessary to protect their @errp with ERRP_GUARD(). To follow the requirement of @errp, add missing ERRP_GUARD() at their beginning. [1]: Issue description in the commit message of commit ae7c80a7bd73 ("error: New macro ERRP_GUARD()"). Cc: "Michael S. Tsirkin" <m...@redhat.com> Signed-off-by: Zhao Liu <zhao1....@intel.com> --- hw/virtio/vhost.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index 2c9ac794680e..2e4e040db87a 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -2199,6 +2199,7 @@ int vhost_check_device_state(struct vhost_dev *dev, Error **errp)int vhost_save_backend_state(struct vhost_dev *dev, QEMUFile *f, Error **errp){ + ERRP_GUARD(); /* Maximum chunk size in which to transfer the state */ const size_t chunk_size = 1 * 1024 * 1024; g_autofree void *transfer_buf = NULL; @@ -2291,6 +2292,7 @@ fail:int vhost_load_backend_state(struct vhost_dev *dev, QEMUFile *f, Error **errp){ + ERRP_GUARD(); size_t transfer_buf_size = 0; g_autofree void *transfer_buf = NULL; g_autoptr(GError) g_err = NULL;
Reviewed-by: Thomas Huth <th...@redhat.com>
