diff options
| author | Breno Leitao <leitao@debian.org> | 2024-11-18 03:15:18 -0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-11-18 19:01:39 -0800 |
| commit | a57d5a72f8dec7db8a79d0016fb0a3bdecc82b56 (patch) | |
| tree | 8689e499621e0d7e495ef6ee3edb36dba7de1726 | |
| parent | c69c5e10adb903ae2438d4f9c16eccf43d1fcbc1 (diff) | |
netpoll: Use rcu_access_pointer() in netpoll_poll_lock
The ndev->npinfo pointer in netpoll_poll_lock() is RCU-protected but is
being accessed directly for a NULL check. While no RCU read lock is held
in this context, we should still use proper RCU primitives for
consistency and correctness.
Replace the direct NULL check with rcu_access_pointer(), which is the
appropriate primitive when only checking for NULL without dereferencing
the pointer. This function provides the necessary ordering guarantees
without requiring RCU read-side protection.
Fixes: bea3348eef27 ("[NET]: Make NAPI polling independent of struct net_device objects.")
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Michal Kubiak <michal.kubiak@intel.com>
Link: https://patch.msgid.link/20241118-netpoll_rcu-v1-2-a1888dcb4a02@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | include/linux/netpoll.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h index cd4e28db0cbd..959a4daacea1 100644 --- a/include/linux/netpoll.h +++ b/include/linux/netpoll.h @@ -72,7 +72,7 @@ static inline void *netpoll_poll_lock(struct napi_struct *napi) { struct net_device *dev = napi->dev; - if (dev && dev->npinfo) { + if (dev && rcu_access_pointer(dev->npinfo)) { int owner = smp_processor_id(); while (cmpxchg(&napi->poll_owner, -1, owner) != -1) |