Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

Pull networking updates from David Miller:

 1) Support ipv6 checksum offload in sunvnet driver, from Shannon
    Nelson.

 2) Move to RB-tree instead of custom AVL code in inetpeer, from Eric
    Dumazet.

 3) Allow generic XDP to work on virtual devices, from John Fastabend.

 4) Add bpf device maps and XDP_REDIRECT, which can be used to build
    arbitrary switching frameworks using XDP. From John Fastabend.

 5) Remove UFO offloads from the tree, gave us little other than bugs.

 6) Remove the IPSEC flow cache, from Florian Westphal.

 7) Support ipv6 route offload in mlxsw driver.

 8) Support VF representors in bnxt_en, from Sathya Perla.

 9) Add support for forward error correction modes to ethtool, from
    Vidya Sagar Ravipati.

10) Add time filter for packet scheduler action dumping, from Jamal Hadi
    Salim.

11) Extend the zerocopy sendmsg() used by virtio and tap to regular
    sockets via MSG_ZEROCOPY. From Willem de Bruijn.

12) Significantly rework value tracking in the BPF verifier, from Edward
    Cree.

13) Add new jump instructions to eBPF, from Daniel Borkmann.

14) Rework rtnetlink plumbing so that operations can be run without
    taking the RTNL semaphore. From Florian Westphal.

15) Support XDP in tap driver, from Jason Wang.

16) Add 32-bit eBPF JIT for ARM, from Shubham Bansal.

17) Add Huawei hinic ethernet driver.

18) Allow to report MD5 keys in TCP inet_diag dumps, from Ivan
    Delalande.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1780 commits)
  i40e: point wb_desc at the nvm_wb_desc during i40e_read_nvm_aq
  i40e: avoid NVM acquire deadlock during NVM update
  drivers: net: xgene: Remove return statement from void function
  drivers: net: xgene: Configure tx/rx delay for ACPI
  drivers: net: xgene: Read tx/rx delay for ACPI
  rocker: fix kcalloc parameter order
  rds: Fix non-atomic operation on shared flag variable
  net: sched: don't use GFP_KERNEL under spin lock
  vhost_net: correctly check tx avail during rx busy polling
  net: mdio-mux: add mdio_mux parameter to mdio_mux_init()
  rxrpc: Make service connection lookup always check for retry
  net: stmmac: Delete dead code for MDIO registration
  gianfar: Fix Tx flow control deactivation
  cxgb4: Ignore MPS_TX_INT_CAUSE[Bubble] for T6
  cxgb4: Fix pause frame count in t4_get_port_stats
  cxgb4: fix memory leak
  tun: rename generic_xdp to skb_xdp
  tun: reserve extra headroom only when XDP is set
  net: dsa: bcm_sf2: Configure IMP port TC2QOS mapping
  net: dsa: bcm_sf2: Advertise number of egress queues
  ...

1 files changed, 33 insertions, 12 deletions

diff --git a/drivers/net/ethernet/intel/i40evf/i40evf_ethtool.c b/drivers/net/ethernet/intel/i40evf/i40evf_ethtool.c
index 9bb2cc7dd4e4..65874d6b3ab9 100644
--- a/drivers/net/ethernet/intel/i40evf/i40evf_ethtool.c
+++ b/drivers/net/ethernet/intel/i40evf/i40evf_ethtool.c
@@ -165,7 +165,7 @@ static void i40evf_get_ethtool_stats(struct net_device *netdev,
 				     struct ethtool_stats *stats, u64 *data)
 {
 	struct i40evf_adapter *adapter = netdev_priv(netdev);
-	int i, j;
+	unsigned int i, j;
 	char *p;
 
 	for (i = 0; i < I40EVF_GLOBAL_STATS_LEN; i++) {
@@ -197,7 +197,7 @@ static void i40evf_get_strings(struct net_device *netdev, u32 sset, u8 *data)
 	int i;
 
 	if (sset == ETH_SS_STATS) {
-		for (i = 0; i < I40EVF_GLOBAL_STATS_LEN; i++) {
+		for (i = 0; i < (int)I40EVF_GLOBAL_STATS_LEN; i++) {
 			memcpy(p, i40evf_gstrings_stats[i].stat_string,
 			       ETH_GSTRING_LEN);
 			p += ETH_GSTRING_LEN;
@@ -258,29 +258,50 @@ static u32 i40evf_get_priv_flags(struct net_device *netdev)
 static int i40evf_set_priv_flags(struct net_device *netdev, u32 flags)
 {
 	struct i40evf_adapter *adapter = netdev_priv(netdev);
-	u64 changed_flags;
+	u32 orig_flags, new_flags, changed_flags;
 	u32 i;
 
-	changed_flags = adapter->flags;
+	orig_flags = READ_ONCE(adapter->flags);
+	new_flags = orig_flags;
 
 	for (i = 0; i < I40EVF_PRIV_FLAGS_STR_LEN; i++) {
 		const struct i40evf_priv_flags *priv_flags;
 
 		priv_flags = &i40evf_gstrings_priv_flags[i];
 
-		if (priv_flags->read_only)
-			continue;
-
 		if (flags & BIT(i))
-			adapter->flags |= priv_flags->flag;
+			new_flags |= priv_flags->flag;
 		else
-			adapter->flags &= ~(priv_flags->flag);
+			new_flags &= ~(priv_flags->flag);
+
+		if (priv_flags->read_only &&
+		    ((orig_flags ^ new_flags) & ~BIT(i)))
+			return -EOPNOTSUPP;
+	}
+
+	/* Before we finalize any flag changes, any checks which we need to
+	 * perform to determine if the new flags will be supported should go
+	 * here...
+	 */
+
+	/* Compare and exchange the new flags into place. If we failed, that
+	 * is if cmpxchg returns anything but the old value, this means
+	 * something else must have modified the flags variable since we
+	 * copied it. We'll just punt with an error and log something in the
+	 * message buffer.
+	 */
+	if (cmpxchg(&adapter->flags, orig_flags, new_flags) != orig_flags) {
+		dev_warn(&adapter->pdev->dev,
+			 "Unable to update adapter->flags as it was modified by another thread...\n");
+		return -EAGAIN;
 	}
 
-	/* check for flags that changed */
-	changed_flags ^= adapter->flags;
+	changed_flags = orig_flags ^ new_flags;
 
-	/* Process any additional changes needed as a result of flag changes. */
+	/* Process any additional changes needed as a result of flag changes.
+	 * The changed_flags value reflects the list of bits that were changed
+	 * in the code above.
+	 */
 
 	/* issue a reset to force legacy-rx change to take effect */
 	if (changed_flags & I40EVF_FLAG_LEGACY_RX) {