[PATCH v2] igb: Add lock to avoid data race
From: Lin Ma <hidden>
Date: 2022-08-09 04:49:21
Also in:
bpf, intel-wired-lan, lkml
Subsystem:
intel ethernet drivers, networking drivers, the rest · Maintainers:
Tony Nguyen, Przemek Kitszel, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
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, just as commit 1e53834ce541 ("ixgbe: Add locking to
prevent panic when setting sriov_numvfs to zero") shows. The
igb_disable_sriov function also need to watch out the requests from VF
driver.
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 just as
1d53834ce541 did.
Fixes: c23d92b80e0b ("igb: Teardown SR-IOV before unregister_netdev()")
Signed-off-by: Lin Ma <redacted>
---
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 { struct igb_mac_addr *mac_table; struct vf_mac_filter vf_macs; struct vf_mac_filter *vf_mac_list; + /* lock for VF resources */ + spinlock_t vfs_lock; }; /* flags controlling PTP/1588 function */
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index d8b836a85cc3..2796e81d2726 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c@@ -3637,6 +3637,7 @@ static int igb_disable_sriov(struct pci_dev *pdev) struct net_device *netdev = pci_get_drvdata(pdev); struct igb_adapter *adapter = netdev_priv(netdev); struct e1000_hw *hw = &adapter->hw; + unsigned long flags; /* reclaim resources allocated to VFs */ if (adapter->vf_data) {
@@ -3649,12 +3650,13 @@ static int igb_disable_sriov(struct pci_dev *pdev) pci_disable_sriov(pdev); msleep(500); } - + spin_lock_irqsave(&adapter->vfs_lock, flags); kfree(adapter->vf_mac_list); adapter->vf_mac_list = NULL; kfree(adapter->vf_data); adapter->vf_data = NULL; adapter->vfs_allocated_count = 0; + spin_unlock_irqrestore(&adapter->vfs_lock, flags); wr32(E1000_IOVCTL, E1000_IOVCTL_REUSE_VFQ); wrfl(); msleep(100);
@@ -3814,7 +3816,9 @@ static void igb_remove(struct pci_dev *pdev) igb_release_hw_control(adapter); #ifdef CONFIG_PCI_IOV + rtnl_lock(); igb_disable_sriov(pdev); + rtnl_unlock(); #endif unregister_netdev(netdev);
@@ -3974,6 +3978,9 @@ static int igb_sw_init(struct igb_adapter *adapter) spin_lock_init(&adapter->nfc_lock); spin_lock_init(&adapter->stats64_lock); + + /* init spinlock to avoid concurrency of VF resources */ + spin_lock_init(&adapter->vfs_lock); #ifdef CONFIG_PCI_IOV switch (hw->mac.type) { case e1000_82576:
@@ -7958,8 +7965,10 @@ static void igb_rcv_msg_from_vf(struct igb_adapter *adapter, u32 vf) static void igb_msg_task(struct igb_adapter *adapter) { struct e1000_hw *hw = &adapter->hw; + unsigned long flags; u32 vf; + spin_lock_irqsave(&adapter->vfs_lock, flags); for (vf = 0; vf < adapter->vfs_allocated_count; vf++) { /* process any reset requests */ if (!igb_check_for_rst(hw, vf))
@@ -7973,6 +7982,7 @@ static void igb_msg_task(struct igb_adapter *adapter) if (!igb_check_for_ack(hw, vf)) igb_rcv_ack_from_vf(adapter, vf); } + spin_unlock_irqrestore(&adapter->vfs_lock, flags); } /**
--
2.36.1