diff options
| author | Eric Dumazet <edumazet@google.com> | 2026-08-12 08:54:39 +0000 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-08-17 10:27:48 -0700 |
| commit | 0c6c32a8c854e570998494b8368d314d526ddbd3 (patch) | |
| tree | cff3777bad39a4f4e9a6342bd8e90bfe79bd570d /include/linux | |
| parent | 21ef2d065ad3f0cfbf2ae51260bf962a9fa2c643 (diff) | |
net: add READ_ONCE()/WRITE_ONCE() annotations for dev->num_tc
Several fast-path and control-path lockless readers access dev->num_tc
(e.g., skb_tx_hash(), netdev_txq_to_tc(), netdev_get_num_tc(), and
qdisc/driver lookups) while concurrent writers update dev->num_tc
during TC setup, device reset, or channel configuration.
Add READ_ONCE() and WRITE_ONCE() annotations to prevent compiler
reordering and load/store tearing when accessing dev->num_tc.
Update inline helpers in netdevice.h (netdev_get_num_tc(),
netdev_set_prio_tc_map(), and netdev_get_sb_channel()) as well as
writers and lockless readers in core networking code and drivers.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260812085440.3917924-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/netdevice.h | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 9d22e6b0df60..fd1916261072 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2678,7 +2678,7 @@ int netdev_get_prio_tc_map(const struct net_device *dev, u32 prio) static inline int netdev_set_prio_tc_map(struct net_device *dev, u8 prio, u8 tc) { - if (tc >= dev->num_tc) + if (tc >= READ_ONCE(dev->num_tc)) return -EINVAL; dev->prio_tc_map[prio & TC_BITMASK] = tc & TC_BITMASK; @@ -2691,9 +2691,9 @@ int netdev_set_tc_queue(struct net_device *dev, u8 tc, u16 count, u16 offset); int netdev_set_num_tc(struct net_device *dev, u8 num_tc); static inline -int netdev_get_num_tc(struct net_device *dev) +int netdev_get_num_tc(const struct net_device *dev) { - return dev->num_tc; + return READ_ONCE(dev->num_tc); } static inline void net_prefetch(void *p) @@ -2720,7 +2720,7 @@ int netdev_bind_sb_channel_queue(struct net_device *dev, int netdev_set_sb_channel(struct net_device *dev, u16 channel); static inline int netdev_get_sb_channel(struct net_device *dev) { - return max_t(int, -dev->num_tc, 0); + return max_t(int, -READ_ONCE(dev->num_tc), 0); } static inline |