migration: Stop postcopy fault thread before notifying

POSTCOPY_NOTIFY_INBOUND_END handlers will remove userfault fds
from the postcopy_remote_fds array which could be still in
use by the fault thread. Let's stop the thread before
notification to avoid possible accessing wrong memory.

Fixes: 46343570c0 ("vhost+postcopy: Wire up POSTCOPY_END notify")
Cc: qemu-stable@nongnu.org
Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
Message-Id: <20181008160536.6332-2-i.maximets@samsung.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
stable-3.1
Ilya Maximets 2018-10-08 19:05:35 +03:00 committed by Dr. David Alan Gilbert
parent 5571dc824b
commit 55d0fe8254
1 changed files with 6 additions and 5 deletions

View File

@ -533,6 +533,12 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis)
if (mis->have_fault_thread) {
Error *local_err = NULL;
/* Let the fault thread quit */
atomic_set(&mis->fault_thread_quit, 1);
postcopy_fault_thread_notify(mis);
trace_postcopy_ram_incoming_cleanup_join();
qemu_thread_join(&mis->fault_thread);
if (postcopy_notify(POSTCOPY_NOTIFY_INBOUND_END, &local_err)) {
error_report_err(local_err);
return -1;
@ -541,11 +547,6 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis)
if (qemu_ram_foreach_migratable_block(cleanup_range, mis)) {
return -1;
}
/* Let the fault thread quit */
atomic_set(&mis->fault_thread_quit, 1);
postcopy_fault_thread_notify(mis);
trace_postcopy_ram_incoming_cleanup_join();
qemu_thread_join(&mis->fault_thread);
trace_postcopy_ram_incoming_cleanup_closeuf();
close(mis->userfault_fd);