Messages in this thread | ![/](/images/icornerl.gif) | | Date | Sat, 6 Apr 2024 10:12:04 +0200 | From | Petr Tesařík <> | Subject | Re: [PATCH net] u64_stats: fix u64_stats_init() for lockdep when used repeatedly in one file |
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On Fri, 5 Apr 2024 20:51:17 +0100 Simon Horman <horms@kernel.org> wrote:
> On Thu, Apr 04, 2024 at 09:57:40AM +0200, Petr Tesarik wrote: > > Fix bogus lockdep warnings if multiple u64_stats_sync variables are > > initialized in the same file. > > > > With CONFIG_LOCKDEP, seqcount_init() is a macro which declares: > > > > static struct lock_class_key __key; > > > > Since u64_stats_init() is a function (albeit an inline one), all calls > > within the same file end up using the same instance, effectively treating > > them all as a single lock-class. > > > > Fixes: 9464ca650008 ("net: make u64_stats_init() a function") > > Closes: https://lore.kernel.org/netdev/ea1567d9-ce66-45e6-8168-ac40a47d1821@roeck-us.net/ > > Signed-off-by: Petr Tesarik <petr@tesarici.cz> > > Reviewed-by: Simon Horman <horms@kernel.org> > > Interesting bug. I'm wondering if you also looked over other users of > u64_stats_init() to see if any of them can result in unexpected aliasing of > lock keys too.
I didn't.
I have now run `git grep u64_stats_init | sed -e 's/:.*//' | uniq -d` and there indeed appears to be some aliasing in other files.
block/blk-cgroup.c: - struct blkg_iostat_set.sync - struct blkg_iostat_set.sync
drivers/net/ethernet/amazon/ena/ena_netdev.c: - struct ena_ring.syncp struct ena_adapter.syncp
drivers/net/ethernet/aquantia/atlantic/aq_ring.c: - struct aq_ring_stats_tx_s.syncp - struct aq_ring_stats_rx_s.syncp
drivers/net/ethernet/emulex/benet/be_main.c: - struct be_tx_stats.sync + aliasing between this struct in - struct be_tx_obj - struct be_rx_obj - struct be_tx_stats.sync_compl
drivers/net/ethernet/google/gve/gve_main.c: - struct gve_priv.rx[].statss - struct gve_priv.tx[].statss
drivers/net/ethernet/intel/fm10k/fm10k_netdev.c: - tx_ring->syncp - rx_ring->syncp
drivers/net/ethernet/intel/i40e/i40e_txrx.c: - tx_ring->syncp - rx_ring->syncp
drivers/net/ethernet/intel/igb/igb_main.c: - struct igb_ring.tx_syncp - struct igb_ring.tx_syncp2 - struct igb_ring.rx_syncp
drivers/net/ethernet/intel/ixgbe/ixgbe_main.c: - struct ixgbe_adapter.rx_ring[]->syncp - struct ixgbe_adapter.tx_ring[]->syncp - struct ixgbe_adapter.xdp_ring[]->syncp
drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c: - tx_ring->syncp - rx_ring->syncp
drivers/net/ethernet/marvell/sky2.c: - struct sky2_port.tx_stats.syncp - struct sky2_port.rx_stats.syncp
drivers/net/ethernet/microsoft/mana/mana_en.c: - struct mana_txq.stats.syncp - struct mana_rxq.stats.syncp
drivers/net/ethernet/netronome/nfp/nfp_net_dp.c: - struct nfp_net_tx_ring.r_vec->tx_sync - struct nfp_net_rx_ring.r_vec->rx_sync
drivers/net/ethernet/nvidia/forcedeth.c: - struct fe_priv.swstats_tx_syncp - struct fe_priv.swstats_rx_syncp
drivers/net/ethernet/realtek/8139too.c: - struct rtl8139_private.tx_stats.syncp - struct rtl8139_private.rx_stats.syncp
drivers/net/ethernet/socionext/sni_ave.c: - struct ave_private.stats_tx.syncp - struct ave_private.stats_rx.syncp
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c: - this was the trigger ;-)
drivers/net/ethernet/ti/netcp_core.c: - struct netcp_stats.syncp_tx - struct netcp_stats.syncp_rx
drivers/net/ethernet/via/via-rhine.c: - struct rhine_private.tx_stats.syncp - struct rhine_private.rx_stats.syncp
drivers/net/ethernet/xilinx/xilinx_axienet_main.c: - struct axienet_local.tx_stat_sync - struct axienet_local.rx_stat_sync
drivers/net/hyperv/netvsc.c: - struct netvsc_channel.tx_stats.syncp - struct netvsc_channel.rx_stats.syncp
drivers/net/ifb.c: - struct ifb_q_private.tx_stats.sync - struct ifb_q_private.rx_stats.sync
drivers/net/mhi_net.c: - struct mhi_net_stats.tx_syncp - struct mhi_net_stats.rx_syncp
drivers/net/virtio_net.c: - struct virtnet_info.rq[].stats.syncp - struct virtnet_info.sq[].stats.syncp
drivers/net/wwan/mhi_wwan_mbim.c: - struct mhi_mbim_link.tx_syncp - struct mhi_mbim_link.rx_syncp
drivers/vdpa/vdpa_sim/vdpa_sim_net.c: - struct vdpasim_net.tx_stats.syncp - struct vdpasim_net.rx_stats.syncp - struct vdpasim_net.cq_stats.syncp
HTH Petr T
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