Re: [Qemu-devel] [PATCH] hw/rdma: Verify that ptr is not NULL before freeing

[Yuval Shaia <yuval.shaia@oracle.com>]

On Mon, Jan 14, 2019 at 04:11:22PM +0100, Philippe Mathieu-Daudé wrote:
> Hi Yuval,
> 
> On 1/14/19 3:10 PM, Yuval Shaia wrote:
> > Make sure objects are not NULL before calling to non-nulll-safe
> 
> null

will fix

> 
> > destructors.
> > 
> > Signed-off-by: Yuval Shaia <yuval.shaia@oracle.com>
> > ---
> >  hw/rdma/rdma_backend.c | 6 ++++--
> >  hw/rdma/rdma_rm.c      | 7 ++++++-
> >  2 files changed, 10 insertions(+), 3 deletions(-)
> > 
> > diff --git a/hw/rdma/rdma_backend.c b/hw/rdma/rdma_backend.c
> > index b49edaacaf..3ee5172c96 100644
> > --- a/hw/rdma/rdma_backend.c
> > +++ b/hw/rdma/rdma_backend.c
> > @@ -1066,8 +1066,10 @@ static void mad_fini(RdmaBackendDev *backend_dev)
> >      pr_dbg("Stopping MAD\n");
> >      disable_rdmacm_mux_async(backend_dev);
> >      qemu_chr_fe_disconnect(backend_dev->rdmacm_mux.chr_be);
> > -    qlist_destroy_obj(QOBJECT(backend_dev->recv_mads_list.list));
> > -    qemu_mutex_destroy(&backend_dev->recv_mads_list.lock);
> > +    if (backend_dev->recv_mads_list.list) {
> 
> This is only reachable when the backend didn't success at initializing,
> right?

Yes, just to cover the case where fini() was called even when init() fails.

> 
> > +        qlist_destroy_obj(QOBJECT(backend_dev->recv_mads_list.list));
> > +        qemu_mutex_destroy(&backend_dev->recv_mads_list.lock);
> > +    }
> >  }
> >  
> >  int rdma_backend_get_gid_index(RdmaBackendDev *backend_dev,
> > diff --git a/hw/rdma/rdma_rm.c b/hw/rdma/rdma_rm.c
> > index f5b1295890..8bf241e91f 100644
> > --- a/hw/rdma/rdma_rm.c
> > +++ b/hw/rdma/rdma_rm.c
> > @@ -41,6 +41,9 @@ static inline void res_tbl_init(const char *name, RdmaRmResTbl *tbl,
> >  
> >  static inline void res_tbl_free(RdmaRmResTbl *tbl)
> >  {
> > +    if (!tbl->bitmap) {
> > +        return;
> > +    }
> >      qemu_mutex_destroy(&tbl->lock);
> >      g_free(tbl->tbl);
> >      g_free(tbl->bitmap);
> > @@ -655,5 +658,7 @@ void rdma_rm_fini(RdmaDeviceResources *dev_res, RdmaBackendDev *backend_dev,
> >      res_tbl_free(&dev_res->cq_tbl);
> >      res_tbl_free(&dev_res->pd_tbl);
> >  
> > -    g_hash_table_destroy(dev_res->qp_hash);
> > +    if (dev_res->qp_hash) {
> > +        g_hash_table_destroy(dev_res->qp_hash);
> > +    }
> >  }
> >