From 386f6c07d28cf1b51e5d0f398faf67d396ff62a1 Mon Sep 17 00:00:00 2001 From: Markus Armbruster Date: Tue, 7 Jul 2020 18:06:10 +0200 Subject: error: Avoid error_propagate() after migrate_add_blocker() When migrate_add_blocker(blocker, &errp) is followed by error_propagate(errp, err), we can often just as well do migrate_add_blocker(..., errp). Do that with this Coccinelle script: @@ expression blocker, err, errp; expression ret; @@ - ret = migrate_add_blocker(blocker, &err); - if (err) { + ret = migrate_add_blocker(blocker, errp); + if (ret < 0) { ... when != err; - error_propagate(errp, err); ... } @@ expression blocker, err, errp; @@ - migrate_add_blocker(blocker, &err); - if (err) { + if (migrate_add_blocker(blocker, errp) < 0) { ... when != err; - error_propagate(errp, err); ... } Double-check @err is not used afterwards. Dereferencing it would be use after free, but checking whether it's null would be legitimate. Signed-off-by: Markus Armbruster Reviewed-by: Eric Blake Reviewed-by: Vladimir Sementsov-Ogievskiy Message-Id: <20200707160613.848843-43-armbru@redhat.com> --- hw/display/virtio-gpu-base.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'hw/display/virtio-gpu-base.c') diff --git a/hw/display/virtio-gpu-base.c b/hw/display/virtio-gpu-base.c index c159351be3..7961308606 100644 --- a/hw/display/virtio-gpu-base.c +++ b/hw/display/virtio-gpu-base.c @@ -128,7 +128,6 @@ virtio_gpu_base_device_realize(DeviceState *qdev, { VirtIODevice *vdev = VIRTIO_DEVICE(qdev); VirtIOGPUBase *g = VIRTIO_GPU_BASE(qdev); - Error *local_err = NULL; int i; if (g->conf.max_outputs > VIRTIO_GPU_MAX_SCANOUTS) { @@ -139,9 +138,7 @@ virtio_gpu_base_device_realize(DeviceState *qdev, g->use_virgl_renderer = false; if (virtio_gpu_virgl_enabled(g->conf)) { error_setg(&g->migration_blocker, "virgl is not yet migratable"); - migrate_add_blocker(g->migration_blocker, &local_err); - if (local_err) { - error_propagate(errp, local_err); + if (migrate_add_blocker(g->migration_blocker, errp) < 0) { error_free(g->migration_blocker); return false; } -- cgit v1.2.3-55-g7522