[PATCH v7 bpf-next 2/6] netdevice: check for net_device::priv_flags bitfield overflow
From: Alexander Lobakin
Date: Wed Feb 17 2021 - 07:05:32 EST
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@xxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx> # Inverted assert condition
---
include/linux/netdevice.h | 199 ++++++++++++++++++++------------------
1 file changed, 105 insertions(+), 94 deletions(-)
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;
--
2.30.1