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/misc/ivshmem.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'hw/misc') diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c index a8dc9b377d..fc128b25e2 100644 --- a/hw/misc/ivshmem.c +++ b/hw/misc/ivshmem.c @@ -898,9 +898,7 @@ static void ivshmem_common_realize(PCIDevice *dev, Error **errp) if (!ivshmem_is_master(s)) { error_setg(&s->migration_blocker, "Migration is disabled when using feature 'peer mode' in device 'ivshmem'"); - migrate_add_blocker(s->migration_blocker, &err); - if (err) { - error_propagate(errp, err); + if (migrate_add_blocker(s->migration_blocker, errp) < 0) { error_free(s->migration_blocker); return; } -- cgit v1.2.3-55-g7522