From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:40746) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1guLRP-0003Sf-Pv for qemu-devel@nongnu.org; Thu, 14 Feb 2019 13:08:56 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1guLRO-00008Y-VY for qemu-devel@nongnu.org; Thu, 14 Feb 2019 13:08:55 -0500 Received: from mail-ot1-x344.google.com ([2607:f8b0:4864:20::344]:36597) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1guLRO-000081-QS for qemu-devel@nongnu.org; Thu, 14 Feb 2019 13:08:54 -0500 Received: by mail-ot1-x344.google.com with SMTP id v62so3239698otb.3 for ; Thu, 14 Feb 2019 10:08:54 -0800 (PST) MIME-Version: 1.0 References: <20190122173111.29821-1-dgilbert@redhat.com> In-Reply-To: <20190122173111.29821-1-dgilbert@redhat.com> From: Peter Maydell Date: Thu, 14 Feb 2019 18:08:41 +0000 Message-ID: Content-Type: text/plain; charset="UTF-8" Subject: Re: [Qemu-devel] [PATCH] migration/rdma: unegister fd handler List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert (git)" Cc: QEMU Developers , jemmy858585@gmail.com, Juan Quintela , Peter Xu On Tue, 22 Jan 2019 at 19:08, Dr. David Alan Gilbert (git) wrote: > > From: "Dr. David Alan Gilbert" > > Unregister the fd handler before we destroy the channel, > otherwise we've got a race where we might land in the > fd handler just as we're closing the device. > > (The race is quite data dependent, you just have to have > the right set of devices for it to trigger). > > Corresponds to RH bz: https://bugzilla.redhat.com/show_bug.cgi?id=1666601 > > Signed-off-by: Dr. David Alan Gilbert > --- > migration/rdma.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/migration/rdma.c b/migration/rdma.c > index 9b2e7e10aa..54a3c11540 100644 > --- a/migration/rdma.c > +++ b/migration/rdma.c > @@ -2321,6 +2321,7 @@ static void qemu_rdma_cleanup(RDMAContext *rdma) > rdma->connected = false; > } > > + qemu_set_fd_handler(rdma->channel->fd, NULL, NULL, NULL); > g_free(rdma->dest_blocks); > rdma->dest_blocks = NULL; Hi -- this patch makes coverity complain (CID 1398634), because here we use rdma->channel without checking that it is NULL, but later in the function we have an "if (rdma->channel)" test. Should this code be conditional on rmda->channel being non-NULL, or is the later test incorrect? thanks -- PMM