| Message ID | 20190214185351.5927-1-dgilbert@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | migration/rdma: Fix qemu_rdma_cleanup null check | expand |
On Thu, Feb 14, 2019 at 06:53:51PM +0000, Dr. David Alan Gilbert (git) wrote: > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com> > > If the migration fails before the channel is open (e.g. a bad > address) we end up in the cleanup with rdma->channel==NULL. > > Spotted by Coverity: CID 1398634 > Fixes: fbbaacab2758cb3f32a0 > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> > --- > migration/rdma.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/migration/rdma.c b/migration/rdma.c > index 54a3c11540..9fa3b176eb 100644 > --- a/migration/rdma.c > +++ b/migration/rdma.c > @@ -2321,7 +2321,9 @@ static void qemu_rdma_cleanup(RDMAContext *rdma) > rdma->connected = false; > } > > - qemu_set_fd_handler(rdma->channel->fd, NULL, NULL, NULL); > + if (rdma->channel) { > + qemu_set_fd_handler(rdma->channel->fd, NULL, NULL, NULL); > + } IIUC there's no strict ordering constraint on resetting the fd handler, then how about simply moving this line into the below "if (rdma->channel)" altogether? Regards,
* Peter Xu (peterx@redhat.com) wrote: > On Thu, Feb 14, 2019 at 06:53:51PM +0000, Dr. David Alan Gilbert (git) wrote: > > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com> > > > > If the migration fails before the channel is open (e.g. a bad > > address) we end up in the cleanup with rdma->channel==NULL. > > > > Spotted by Coverity: CID 1398634 > > Fixes: fbbaacab2758cb3f32a0 > > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> > > --- > > migration/rdma.c | 4 +++- > > 1 file changed, 3 insertions(+), 1 deletion(-) > > > > diff --git a/migration/rdma.c b/migration/rdma.c > > index 54a3c11540..9fa3b176eb 100644 > > --- a/migration/rdma.c > > +++ b/migration/rdma.c > > @@ -2321,7 +2321,9 @@ static void qemu_rdma_cleanup(RDMAContext *rdma) > > rdma->connected = false; > > } > > > > - qemu_set_fd_handler(rdma->channel->fd, NULL, NULL, NULL); > > + if (rdma->channel) { > > + qemu_set_fd_handler(rdma->channel->fd, NULL, NULL, NULL); > > + } > > IIUC there's no strict ordering constraint on resetting the fd > handler, then how about simply moving this line into the below "if > (rdma->channel)" altogether? The logic around the closing of the return path makes that check later a bit messy; rdma->channel can get set to Null before the other check. Dave > Regards, > > -- > Peter Xu -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
On 2/14/19 7:53 PM, Dr. David Alan Gilbert (git) wrote: > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com> > > If the migration fails before the channel is open (e.g. a bad > address) we end up in the cleanup with rdma->channel==NULL. > > Spotted by Coverity: CID 1398634 > Fixes: fbbaacab2758cb3f32a0 > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> > --- > migration/rdma.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/migration/rdma.c b/migration/rdma.c > index 54a3c11540..9fa3b176eb 100644 > --- a/migration/rdma.c > +++ b/migration/rdma.c > @@ -2321,7 +2321,9 @@ static void qemu_rdma_cleanup(RDMAContext *rdma) > rdma->connected = false; > } > > - qemu_set_fd_handler(rdma->channel->fd, NULL, NULL, NULL); > + if (rdma->channel) { > + qemu_set_fd_handler(rdma->channel->fd, NULL, NULL, NULL); > + } > g_free(rdma->dest_blocks); > rdma->dest_blocks = NULL; > > Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
On Fri, Feb 15, 2019 at 11:00:56AM +0000, Dr. David Alan Gilbert wrote: > * Peter Xu (peterx@redhat.com) wrote: > > On Thu, Feb 14, 2019 at 06:53:51PM +0000, Dr. David Alan Gilbert (git) wrote: > > > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com> > > > > > > If the migration fails before the channel is open (e.g. a bad > > > address) we end up in the cleanup with rdma->channel==NULL. > > > > > > Spotted by Coverity: CID 1398634 > > > Fixes: fbbaacab2758cb3f32a0 > > > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> > > > --- > > > migration/rdma.c | 4 +++- > > > 1 file changed, 3 insertions(+), 1 deletion(-) > > > > > > diff --git a/migration/rdma.c b/migration/rdma.c > > > index 54a3c11540..9fa3b176eb 100644 > > > --- a/migration/rdma.c > > > +++ b/migration/rdma.c > > > @@ -2321,7 +2321,9 @@ static void qemu_rdma_cleanup(RDMAContext *rdma) > > > rdma->connected = false; > > > } > > > > > > - qemu_set_fd_handler(rdma->channel->fd, NULL, NULL, NULL); > > > + if (rdma->channel) { > > > + qemu_set_fd_handler(rdma->channel->fd, NULL, NULL, NULL); > > > + } > > > > IIUC there's no strict ordering constraint on resetting the fd > > handler, then how about simply moving this line into the below "if > > (rdma->channel)" altogether? > > The logic around the closing of the return path makes that check later a > bit messy; rdma->channel can get set to Null before the other check. Ah I see, it's the mess by sharing listen_id and channel on destination side... Maybe we can clean them up along the way? I gave it a shot: if (rdma->listen_id && rdma->is_return_path) { /* * The return path on the destination side, both listen_id and * channel are shared with the other context so we skip * freeing those but simply clear the pointers no matter what. * The main context will help us to clean these. */ rdma->listen_id = NULL; rdma->channel = NULL; } else { /* * Either the source side, or the main context of the * destination side: we are responsible for listen_id/channel */ if (rdma->listen_id) { rdma_destroy_id(rdma->listen_id); rdma->listen_id = NULL; } if (rdma->channel) { qemu_set_fd_handler(rdma->channel->fd, NULL, NULL, NULL); rdma_destroy_event_channel(rdma->channel); rdma->channel = NULL; } } I slightly prefer to clean it up (if someone is still going to maintain the RDMA code... :), but either way is fine to me. No matter what you prefer: Reviewed-by: Peter Xu <peterx@redhat.com> Thanks,
* Dr. David Alan Gilbert (git) (dgilbert@redhat.com) wrote: > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com> > > If the migration fails before the channel is open (e.g. a bad > address) we end up in the cleanup with rdma->channel==NULL. > > Spotted by Coverity: CID 1398634 > Fixes: fbbaacab2758cb3f32a0 > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Queued > --- > migration/rdma.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/migration/rdma.c b/migration/rdma.c > index 54a3c11540..9fa3b176eb 100644 > --- a/migration/rdma.c > +++ b/migration/rdma.c > @@ -2321,7 +2321,9 @@ static void qemu_rdma_cleanup(RDMAContext *rdma) > rdma->connected = false; > } > > - qemu_set_fd_handler(rdma->channel->fd, NULL, NULL, NULL); > + if (rdma->channel) { > + qemu_set_fd_handler(rdma->channel->fd, NULL, NULL, NULL); > + } > g_free(rdma->dest_blocks); > rdma->dest_blocks = NULL; > > -- > 2.20.1 > > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
diff --git a/migration/rdma.c b/migration/rdma.c index 54a3c11540..9fa3b176eb 100644 --- a/migration/rdma.c +++ b/migration/rdma.c @@ -2321,7 +2321,9 @@ static void qemu_rdma_cleanup(RDMAContext *rdma) rdma->connected = false; } - qemu_set_fd_handler(rdma->channel->fd, NULL, NULL, NULL); + if (rdma->channel) { + qemu_set_fd_handler(rdma->channel->fd, NULL, NULL, NULL); + } g_free(rdma->dest_blocks); rdma->dest_blocks = NULL;