From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44867) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gAgaZ-0004vf-PT for qemu-devel@nongnu.org; Thu, 11 Oct 2018 15:25:40 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gAgaU-0001dS-Tz for qemu-devel@nongnu.org; Thu, 11 Oct 2018 15:25:39 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47238) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gAgaU-0001X0-Fm for qemu-devel@nongnu.org; Thu, 11 Oct 2018 15:25:34 -0400 From: "Dr. David Alan Gilbert (git)" Date: Thu, 11 Oct 2018 20:25:09 +0100 Message-Id: <20181011192513.63634-4-dgilbert@redhat.com> In-Reply-To: <20181011192513.63634-1-dgilbert@redhat.com> References: <20181011192513.63634-1-dgilbert@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PULL 3/7] migration: Stop postcopy fault thread before notifying List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, quintela@redhat.com Cc: wei@redhat.com, thuth@redhat.com, i.maximets@samsung.com, den@openvz.org From: Ilya Maximets 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: 46343570c06e ("vhost+postcopy: Wire up POSTCOPY_END notify") Cc: qemu-stable@nongnu.org Signed-off-by: Ilya Maximets Message-Id: <20181008160536.6332-2-i.maximets@samsung.com> Reviewed-by: Dr. David Alan Gilbert Reviewed-by: Maxime Coquelin Signed-off-by: Dr. David Alan Gilbert --- migration/postcopy-ram.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c index 853d8b32ca..e5c02a32c5 100644 --- a/migration/postcopy-ram.c +++ b/migration/postcopy-ram.c @@ -533,6 +533,12 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingS= tate *mis) if (mis->have_fault_thread) { Error *local_err =3D NULL; =20 + /* 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(MigrationIncomingS= tate *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); =20 trace_postcopy_ram_incoming_cleanup_closeuf(); close(mis->userfault_fd); --=20 2.19.0