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| author | Breno Leitao <leitao@debian.org> | 2024-11-18 03:15:18 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-12-05 14:02:01 +0100 |
| commit | 6b8b9d9b06fba7ff430a7885a79ee07c518d8618 (patch) | |
| tree | 8d3ee57eabf86498dea5db0f61d3f777f809d1da /include | |
| parent | fc1ed75f381f78e5555475f8de931eefc0769caf (diff) | |
| download | linux-6b8b9d9b06fba7ff430a7885a79ee07c518d8618.tar.gz linux-6b8b9d9b06fba7ff430a7885a79ee07c518d8618.tar.bz2 linux-6b8b9d9b06fba7ff430a7885a79ee07c518d8618.zip | |
netpoll: Use rcu_access_pointer() in netpoll_poll_lock
[ Upstream commit a57d5a72f8dec7db8a79d0016fb0a3bdecc82b56 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'include')
| -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) |