Re: [libvirt] [PATCH 5/6] libxl: Add refcnt for args->conn during migration

On Tue, Apr 24, 2018 at 08:28:08AM -0400, John Ferlan wrote: > Since the @dconn reference via args->conn will be used via a thread > or callback, let's make sure memory associated with it isn't free'd > unexpectedly before we use it. The Unref will be done when the object > is Dispose'd. > > Signed-off-by: John Ferlan <jferlan(a)redhat.com&gt; > --- > src/libxl/libxl_migration.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/src/libxl/libxl_migration.c b/src/libxl/libxl_migration.c > index 7fe352306c..d37a4a687a 100644 > --- a/src/libxl/libxl_migration.c > +++ b/src/libxl/libxl_migration.c > @@ -239,6 +239,7 @@ libxlMigrationDstArgsDispose(void *obj) > > libxlMigrationCookieFree(args->migcookie); > VIR_FREE(args->socks); > + virObjectUnref(args->conn); > virObjectUnref(args->vm); > } > > @@ -608,7 +609,7 @@ libxlDomainMigrationDstPrepareTunnel3(virConnectPtr dconn, > if (!(args = virObjectNew(libxlMigrationDstArgsClass))) > goto error; > > - args->conn = dconn; > + args->conn = virObjectRef(dconn); > args->vm = virObjectRef(vm); > args->flags = flags; > args->migcookie = mig; > @@ -763,7 +764,7 @@ libxlDomainMigrationDstPrepare(virConnectPtr dconn, > if (!(args = virObjectNew(libxlMigrationDstArgsClass))) > goto error; > > - args->conn = dconn; > + args->conn = virObjectRef(dconn); > args->vm = virObjectRef(vm); > args->flags = flags; > args->socks = socks; Do you actually have a use case, where the conn object would be destroyed before the migration finishes in a way that this could cause a SIGSEGV?