On Fri, Mar 6, 2020 at 7:06 PM <[email protected]> wrote: > > From: Tonghao Zhang <[email protected]> > > The order of mempool initiation affects mempool index in the > rte_mempool_ops_table. For example, when building APPs with: > > $ gcc -lrte_mempool_bucket -lrte_mempool_ring ... > > The "bucket" mempool will be registered firstly, and its index > in table is 0 while the index of "ring" mempool is 1. DPDK > uses the mk/rte.app.mk to build APPs, and others, for example, > Open vSwitch, use the libdpdk.a or libdpdk.so to build it. > The mempool lib linked in dpdk and Open vSwitch is different. > > The mempool can be used between primary and secondary process, > such as dpdk-pdump and pdump-pmd/Open vSwitch(pdump enabled). > There will be a crash because dpdk-pdump creates the "ring_mp_mc" > ring which index in table is 0, but the index of "bucket" ring > is 0 in Open vSwitch. If Open vSwitch use the index 0 to get > mempool ops and malloc memory from mempool. The crash will occur: > > bucket_dequeue (access null and crash) > rte_mempool_get_ops (should get "ring_mp_mc", > but get "bucket" mempool) > rte_mempool_ops_dequeue_bulk > ... > rte_pktmbuf_alloc > rte_pktmbuf_copy > pdump_copy > pdump_rx > rte_eth_rx_burst > > To avoid the crash, there are some solution: > * constructor priority: Different mempool uses different > priority in RTE_INIT, but it's not easy to maintain. > > * change mk/rte.app.mk: Change the order in mk/rte.app.mk to > be same as libdpdk.a/libdpdk.so, but when adding a new mempool > driver in future, we must make sure the order. > > * register mempool orderly: Sort the mempool when registering, > so the lib linked will not affect the index in mempool table. > > Signed-off-by: Tonghao Zhang <[email protected]> > Acked-by: Olivier Matz <[email protected]>
Acked-by: Jerin Jacob <[email protected]> > --- > v3: > * fix checkpatches.sh WARNING > * change "initiation -> initialization" > > v2: > * use the qsort to sort the mempool_ops. > * tested: > https://travis-ci.com/ovn-open-virtual-networks/dpdk-next-net/builds/151894026 > --- > lib/librte_mempool/rte_mempool_ops.c | 16 ++++++++++++++++ > 1 file changed, 16 insertions(+) > > diff --git a/lib/librte_mempool/rte_mempool_ops.c > b/lib/librte_mempool/rte_mempool_ops.c > index 22c5251..b0da096 100644 > --- a/lib/librte_mempool/rte_mempool_ops.c > +++ b/lib/librte_mempool/rte_mempool_ops.c > @@ -17,6 +17,15 @@ struct rte_mempool_ops_table rte_mempool_ops_table = { > .num_ops = 0 > }; > > +static int > +compare_mempool_ops(const void *a, const void *b) > +{ > + const struct rte_mempool_ops *m_a = a; > + const struct rte_mempool_ops *m_b = b; > + > + return strcmp(m_a->name, m_b->name); > +} > + > /* add a new ops struct in rte_mempool_ops_table, return its index. */ > int > rte_mempool_register_ops(const struct rte_mempool_ops *h) > @@ -63,6 +72,13 @@ struct rte_mempool_ops_table rte_mempool_ops_table = { > ops->get_info = h->get_info; > ops->dequeue_contig_blocks = h->dequeue_contig_blocks; > > + /* > + * sort the rte_mempool_ops by name. the order of the mempool > + * lib initialization will not affect rte_mempool_ops index. > + */ > + qsort(rte_mempool_ops_table.ops, rte_mempool_ops_table.num_ops, > + sizeof(rte_mempool_ops_table.ops[0]), compare_mempool_ops); > + > rte_spinlock_unlock(&rte_mempool_ops_table.sl); > > return ops_index; > -- > 1.8.3.1 >
