Messages in this thread | | | From | "Jankowski, Konrad0" <> | Subject | RE: [Intel-wired-lan] [PATCH v3] igb: Add lock to avoid data race | Date | Tue, 16 Aug 2022 10:35:05 +0000 |
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> -----Original Message----- > From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of > Lin Ma > Sent: Tuesday, August 9, 2022 9:36 AM > To: Brandeburg, Jesse <jesse.brandeburg@intel.com>; Nguyen, Anthony L > <anthony.l.nguyen@intel.com>; davem@davemloft.net; > edumazet@google.com; kuba@kernel.org; pabeni@redhat.com; > ast@kernel.org; daniel@iogearbox.net; hawk@kernel.org; > john.fastabend@gmail.com; intel-wired-lan@lists.osuosl.org; > netdev@vger.kernel.org; linux-kernel@vger.kernel.org; > bpf@vger.kernel.org > Cc: Lin Ma <linma@zju.edu.cn> > Subject: [Intel-wired-lan] [PATCH v3] igb: Add lock to avoid data race > > The commit c23d92b80e0b ("igb: Teardown SR-IOV before > unregister_netdev()") places the unregister_netdev() call after the > igb_disable_sriov() call to avoid functionality issue. > > However, it introduces several race conditions when detaching a device. > For example, when .remove() is called, the below interleaving leads to use- > after-free. > > (FREE from device detaching) | (USE from netdev core) > igb_remove | igb_ndo_get_vf_config > igb_disable_sriov | vf >= adapter->vfs_allocated_count? > kfree(adapter->vf_data) | > adapter->vfs_allocated_count = 0 | > | memcpy(... adapter->vf_data[vf] > > Moreover, the igb_disable_sriov() also suffers from data race with the > requests from VF driver. > > (FREE from device detaching) | (USE from requests) > igb_remove | igb_msix_other > igb_disable_sriov | igb_msg_task > kfree(adapter->vf_data) | vf < adapter->vfs_allocated_count > adapter->vfs_allocated_count = 0 | > > To this end, this commit first eliminates the data races from netdev core by > using rtnl_lock (similar to commit 719479230893 ("dpaa2-eth: add MAC/PHY > support through phylink")). And then adds a spinlock to eliminate races from > driver requests. (similar to commit 1e53834ce541 > ("ixgbe: Add locking to prevent panic when setting sriov_numvfs to zero") > > > Fixes: c23d92b80e0b ("igb: Teardown SR-IOV before unregister_netdev()") > Signed-off-by: Lin Ma <linma@zju.edu.cn> > --- > V2 -> V3: make the commit message much clear > V1 -> V2: fix typo in title idb -> igb > V0 -> V1: change title from "Add rtnl_lock" to "Add lock" > add additional spinlock as suggested by Jakub, according to > 1e53834ce541 ("ixgbe: Add locking to prevent panic when setting > sriov_numvfs to zero") > > drivers/net/ethernet/intel/igb/igb.h | 2 ++ > drivers/net/ethernet/intel/igb/igb_main.c | 12 +++++++++++- > 2 files changed, 13 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/ethernet/intel/igb/igb.h > b/drivers/net/ethernet/intel/igb/igb.h > index 2d3daf022651..015b78144114 100644 > --- a/drivers/net/ethernet/intel/igb/igb.h > +++ b/drivers/net/ethernet/intel/igb/igb.h > @@ -664,6 +664,8 @@ struct igb_adapter {
Tested-by: Konrad Jankowski <konrad0.jankowski@intel.com>
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