[v7,bpf-next,2/6] netdevice: check for net_device::priv_flags bitfield overflow
diff mbox series

Message ID 20210217120003.7938-3-alobakin@pm.me
State New, archived
Headers show
Series
  • xsk: build skb by page (aka generic zerocopy xmit)
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Commit Message

Alexander Lobakin Feb. 17, 2021, 12:01 p.m. UTC
We almost ran out of unsigned int bitwidth. Define priv flags and
check for potential overflow in the fashion of netdev_features_t.
Defined this way, priv_flags can be easily expanded later with
just changing its typedef.

Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Reported-by: kernel test robot <lkp@intel.com> # Inverted assert condition
---
 include/linux/netdevice.h | 199 ++++++++++++++++++++------------------
 1 file changed, 105 insertions(+), 94 deletions(-)

Patch
diff mbox series

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 3b6f82c2c271..2c1a642ecdc0 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1483,107 +1483,118 @@  struct net_device_ops {
  *
  * You should have a pretty good reason to be extending these flags.
  *
- * @IFF_802_1Q_VLAN: 802.1Q VLAN device
- * @IFF_EBRIDGE: Ethernet bridging device
- * @IFF_BONDING: bonding master or slave
- * @IFF_ISATAP: ISATAP interface (RFC4214)
- * @IFF_WAN_HDLC: WAN HDLC device
- * @IFF_XMIT_DST_RELEASE: dev_hard_start_xmit() is allowed to
+ * @IFF_802_1Q_VLAN_BIT: 802.1Q VLAN device
+ * @IFF_EBRIDGE_BIT: Ethernet bridging device
+ * @IFF_BONDING_BIT: bonding master or slave
+ * @IFF_ISATAP_BIT: ISATAP interface (RFC4214)
+ * @IFF_WAN_HDLC_BIT: WAN HDLC device
+ * @IFF_XMIT_DST_RELEASE_BIT: dev_hard_start_xmit() is allowed to
  *	release skb->dst
- * @IFF_DONT_BRIDGE: disallow bridging this ether dev
- * @IFF_DISABLE_NETPOLL: disable netpoll at run-time
- * @IFF_MACVLAN_PORT: device used as macvlan port
- * @IFF_BRIDGE_PORT: device used as bridge port
- * @IFF_OVS_DATAPATH: device used as Open vSwitch datapath port
- * @IFF_TX_SKB_SHARING: The interface supports sharing skbs on transmit
- * @IFF_UNICAST_FLT: Supports unicast filtering
- * @IFF_TEAM_PORT: device used as team port
- * @IFF_SUPP_NOFCS: device supports sending custom FCS
- * @IFF_LIVE_ADDR_CHANGE: device supports hardware address
+ * @IFF_DONT_BRIDGE_BIT: disallow bridging this ether dev
+ * @IFF_DISABLE_NETPOLL_BIT: disable netpoll at run-time
+ * @IFF_MACVLAN_PORT_BIT: device used as macvlan port
+ * @IFF_BRIDGE_PORT_BIT: device used as bridge port
+ * @IFF_OVS_DATAPATH_BIT: device used as Open vSwitch datapath port
+ * @IFF_TX_SKB_SHARING_BIT: The interface supports sharing skbs on transmit
+ * @IFF_UNICAST_FLT_BIT: Supports unicast filtering
+ * @IFF_TEAM_PORT_BIT: device used as team port
+ * @IFF_SUPP_NOFCS_BIT: device supports sending custom FCS
+ * @IFF_LIVE_ADDR_CHANGE_BIT: device supports hardware address
  *	change when it's running
- * @IFF_MACVLAN: Macvlan device
- * @IFF_XMIT_DST_RELEASE_PERM: IFF_XMIT_DST_RELEASE not taking into account
+ * @IFF_MACVLAN_BIT: Macvlan device
+ * @IFF_XMIT_DST_RELEASE_PERM_BIT: IFF_XMIT_DST_RELEASE not taking into account
  *	underlying stacked devices
- * @IFF_L3MDEV_MASTER: device is an L3 master device
- * @IFF_NO_QUEUE: device can run without qdisc attached
- * @IFF_OPENVSWITCH: device is a Open vSwitch master
- * @IFF_L3MDEV_SLAVE: device is enslaved to an L3 master device
- * @IFF_TEAM: device is a team device
- * @IFF_RXFH_CONFIGURED: device has had Rx Flow indirection table configured
- * @IFF_PHONY_HEADROOM: the headroom value is controlled by an external
+ * @IFF_L3MDEV_MASTER_BIT: device is an L3 master device
+ * @IFF_NO_QUEUE_BIT: device can run without qdisc attached
+ * @IFF_OPENVSWITCH_BIT: device is a Open vSwitch master
+ * @IFF_L3MDEV_SLAVE_BIT: device is enslaved to an L3 master device
+ * @IFF_TEAM_BIT: device is a team device
+ * @IFF_RXFH_CONFIGURED_BIT: device has had Rx Flow indirection table configured
+ * @IFF_PHONY_HEADROOM_BIT: the headroom value is controlled by an external
  *	entity (i.e. the master device for bridged veth)
- * @IFF_MACSEC: device is a MACsec device
- * @IFF_NO_RX_HANDLER: device doesn't support the rx_handler hook
- * @IFF_FAILOVER: device is a failover master device
- * @IFF_FAILOVER_SLAVE: device is lower dev of a failover master device
- * @IFF_L3MDEV_RX_HANDLER: only invoke the rx handler of L3 master device
- * @IFF_LIVE_RENAME_OK: rename is allowed while device is up and running
+ * @IFF_MACSEC_BIT: device is a MACsec device
+ * @IFF_NO_RX_HANDLER_BIT: device doesn't support the rx_handler hook
+ * @IFF_FAILOVER_BIT: device is a failover master device
+ * @IFF_FAILOVER_SLAVE_BIT: device is lower dev of a failover master device
+ * @IFF_L3MDEV_RX_HANDLER_BIT: only invoke the rx handler of L3 master device
+ * @IFF_LIVE_RENAME_OK_BIT: rename is allowed while device is up and running
+ *
+ * @NETDEV_PRIV_FLAG_COUNT: total priv flags count
  */
 enum netdev_priv_flags {
-	IFF_802_1Q_VLAN			= 1<<0,
-	IFF_EBRIDGE			= 1<<1,
-	IFF_BONDING			= 1<<2,
-	IFF_ISATAP			= 1<<3,
-	IFF_WAN_HDLC			= 1<<4,
-	IFF_XMIT_DST_RELEASE		= 1<<5,
-	IFF_DONT_BRIDGE			= 1<<6,
-	IFF_DISABLE_NETPOLL		= 1<<7,
-	IFF_MACVLAN_PORT		= 1<<8,
-	IFF_BRIDGE_PORT			= 1<<9,
-	IFF_OVS_DATAPATH		= 1<<10,
-	IFF_TX_SKB_SHARING		= 1<<11,
-	IFF_UNICAST_FLT			= 1<<12,
-	IFF_TEAM_PORT			= 1<<13,
-	IFF_SUPP_NOFCS			= 1<<14,
-	IFF_LIVE_ADDR_CHANGE		= 1<<15,
-	IFF_MACVLAN			= 1<<16,
-	IFF_XMIT_DST_RELEASE_PERM	= 1<<17,
-	IFF_L3MDEV_MASTER		= 1<<18,
-	IFF_NO_QUEUE			= 1<<19,
-	IFF_OPENVSWITCH			= 1<<20,
-	IFF_L3MDEV_SLAVE		= 1<<21,
-	IFF_TEAM			= 1<<22,
-	IFF_RXFH_CONFIGURED		= 1<<23,
-	IFF_PHONY_HEADROOM		= 1<<24,
-	IFF_MACSEC			= 1<<25,
-	IFF_NO_RX_HANDLER		= 1<<26,
-	IFF_FAILOVER			= 1<<27,
-	IFF_FAILOVER_SLAVE		= 1<<28,
-	IFF_L3MDEV_RX_HANDLER		= 1<<29,
-	IFF_LIVE_RENAME_OK		= 1<<30,
+	IFF_802_1Q_VLAN_BIT,
+	IFF_EBRIDGE_BIT,
+	IFF_BONDING_BIT,
+	IFF_ISATAP_BIT,
+	IFF_WAN_HDLC_BIT,
+	IFF_XMIT_DST_RELEASE_BIT,
+	IFF_DONT_BRIDGE_BIT,
+	IFF_DISABLE_NETPOLL_BIT,
+	IFF_MACVLAN_PORT_BIT,
+	IFF_BRIDGE_PORT_BIT,
+	IFF_OVS_DATAPATH_BIT,
+	IFF_TX_SKB_SHARING_BIT,
+	IFF_UNICAST_FLT_BIT,
+	IFF_TEAM_PORT_BIT,
+	IFF_SUPP_NOFCS_BIT,
+	IFF_LIVE_ADDR_CHANGE_BIT,
+	IFF_MACVLAN_BIT,
+	IFF_XMIT_DST_RELEASE_PERM_BIT,
+	IFF_L3MDEV_MASTER_BIT,
+	IFF_NO_QUEUE_BIT,
+	IFF_OPENVSWITCH_BIT,
+	IFF_L3MDEV_SLAVE_BIT,
+	IFF_TEAM_BIT,
+	IFF_RXFH_CONFIGURED_BIT,
+	IFF_PHONY_HEADROOM_BIT,
+	IFF_MACSEC_BIT,
+	IFF_NO_RX_HANDLER_BIT,
+	IFF_FAILOVER_BIT,
+	IFF_FAILOVER_SLAVE_BIT,
+	IFF_L3MDEV_RX_HANDLER_BIT,
+	IFF_LIVE_RENAME_OK_BIT,
+
+	NETDEV_PRIV_FLAG_COUNT,
 };
 
-#define IFF_802_1Q_VLAN			IFF_802_1Q_VLAN
-#define IFF_EBRIDGE			IFF_EBRIDGE
-#define IFF_BONDING			IFF_BONDING
-#define IFF_ISATAP			IFF_ISATAP
-#define IFF_WAN_HDLC			IFF_WAN_HDLC
-#define IFF_XMIT_DST_RELEASE		IFF_XMIT_DST_RELEASE
-#define IFF_DONT_BRIDGE			IFF_DONT_BRIDGE
-#define IFF_DISABLE_NETPOLL		IFF_DISABLE_NETPOLL
-#define IFF_MACVLAN_PORT		IFF_MACVLAN_PORT
-#define IFF_BRIDGE_PORT			IFF_BRIDGE_PORT
-#define IFF_OVS_DATAPATH		IFF_OVS_DATAPATH
-#define IFF_TX_SKB_SHARING		IFF_TX_SKB_SHARING
-#define IFF_UNICAST_FLT			IFF_UNICAST_FLT
-#define IFF_TEAM_PORT			IFF_TEAM_PORT
-#define IFF_SUPP_NOFCS			IFF_SUPP_NOFCS
-#define IFF_LIVE_ADDR_CHANGE		IFF_LIVE_ADDR_CHANGE
-#define IFF_MACVLAN			IFF_MACVLAN
-#define IFF_XMIT_DST_RELEASE_PERM	IFF_XMIT_DST_RELEASE_PERM
-#define IFF_L3MDEV_MASTER		IFF_L3MDEV_MASTER
-#define IFF_NO_QUEUE			IFF_NO_QUEUE
-#define IFF_OPENVSWITCH			IFF_OPENVSWITCH
-#define IFF_L3MDEV_SLAVE		IFF_L3MDEV_SLAVE
-#define IFF_TEAM			IFF_TEAM
-#define IFF_RXFH_CONFIGURED		IFF_RXFH_CONFIGURED
-#define IFF_PHONY_HEADROOM		IFF_PHONY_HEADROOM
-#define IFF_MACSEC			IFF_MACSEC
-#define IFF_NO_RX_HANDLER		IFF_NO_RX_HANDLER
-#define IFF_FAILOVER			IFF_FAILOVER
-#define IFF_FAILOVER_SLAVE		IFF_FAILOVER_SLAVE
-#define IFF_L3MDEV_RX_HANDLER		IFF_L3MDEV_RX_HANDLER
-#define IFF_LIVE_RENAME_OK		IFF_LIVE_RENAME_OK
+typedef u32 netdev_priv_flags_t;
+static_assert(sizeof(netdev_priv_flags_t) * BITS_PER_BYTE >=
+	      NETDEV_PRIV_FLAG_COUNT);
+
+#define __IFF_BIT(bit)			((netdev_priv_flags_t)1 << (bit))
+#define __IFF(name)			__IFF_BIT(IFF_##name##_BIT)
+
+#define IFF_802_1Q_VLAN			__IFF(802_1Q_VLAN)
+#define IFF_EBRIDGE			__IFF(EBRIDGE)
+#define IFF_BONDING			__IFF(BONDING)
+#define IFF_ISATAP			__IFF(ISATAP)
+#define IFF_WAN_HDLC			__IFF(WAN_HDLC)
+#define IFF_XMIT_DST_RELEASE		__IFF(XMIT_DST_RELEASE)
+#define IFF_DONT_BRIDGE			__IFF(DONT_BRIDGE)
+#define IFF_DISABLE_NETPOLL		__IFF(DISABLE_NETPOLL)
+#define IFF_MACVLAN_PORT		__IFF(MACVLAN_PORT)
+#define IFF_BRIDGE_PORT			__IFF(BRIDGE_PORT)
+#define IFF_OVS_DATAPATH		__IFF(OVS_DATAPATH)
+#define IFF_TX_SKB_SHARING		__IFF(TX_SKB_SHARING)
+#define IFF_UNICAST_FLT			__IFF(UNICAST_FLT)
+#define IFF_TEAM_PORT			__IFF(TEAM_PORT)
+#define IFF_SUPP_NOFCS			__IFF(SUPP_NOFCS)
+#define IFF_LIVE_ADDR_CHANGE		__IFF(LIVE_ADDR_CHANGE)
+#define IFF_MACVLAN			__IFF(MACVLAN)
+#define IFF_XMIT_DST_RELEASE_PERM	__IFF(XMIT_DST_RELEASE_PERM)
+#define IFF_L3MDEV_MASTER		__IFF(L3MDEV_MASTER)
+#define IFF_NO_QUEUE			__IFF(NO_QUEUE)
+#define IFF_OPENVSWITCH			__IFF(OPENVSWITCH)
+#define IFF_L3MDEV_SLAVE		__IFF(L3MDEV_SLAVE)
+#define IFF_TEAM			__IFF(TEAM)
+#define IFF_RXFH_CONFIGURED		__IFF(RXFH_CONFIGURED)
+#define IFF_PHONY_HEADROOM		__IFF(PHONY_HEADROOM)
+#define IFF_MACSEC			__IFF(MACSEC)
+#define IFF_NO_RX_HANDLER		__IFF(NO_RX_HANDLER)
+#define IFF_FAILOVER			__IFF(FAILOVER)
+#define IFF_FAILOVER_SLAVE		__IFF(FAILOVER_SLAVE)
+#define IFF_L3MDEV_RX_HANDLER		__IFF(L3MDEV_RX_HANDLER)
+#define IFF_LIVE_RENAME_OK		__IFF(LIVE_RENAME_OK)
 
 /**
  *	struct net_device - The DEVICE structure.
@@ -1876,7 +1887,7 @@  struct net_device {
 
 	/* Read-mostly cache-line for fast-path access */
 	unsigned int		flags;
-	unsigned int		priv_flags;
+	netdev_priv_flags_t	priv_flags;
 	const struct net_device_ops *netdev_ops;
 	int			ifindex;
 	unsigned short		gflags;