From: Breno Leitao Date: Mon, 18 Nov 2024 11:15:17 +0000 (-0800) Subject: netpoll: Use rcu_access_pointer() in __netpoll_setup X-Git-Tag: microblaze-v6.16~280^2~23^2~3^2~1 X-Git-Url: http://git.monstr.eu/?a=commitdiff_plain;h=c69c5e10adb903ae2438d4f9c16eccf43d1fcbc1;p=linux-2.6-microblaze.git netpoll: Use rcu_access_pointer() in __netpoll_setup The ndev->npinfo pointer in __netpoll_setup() 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. Reviewed-by: Michal Kubiak Signed-off-by: Breno Leitao Link: https://patch.msgid.link/20241118-netpoll_rcu-v1-1-a1888dcb4a02@debian.org Signed-off-by: Jakub Kicinski --- diff --git a/net/core/netpoll.c b/net/core/netpoll.c index aa49b92e9194..45fb60bc4803 100644 --- a/net/core/netpoll.c +++ b/net/core/netpoll.c @@ -626,7 +626,7 @@ int __netpoll_setup(struct netpoll *np, struct net_device *ndev) goto out; } - if (!ndev->npinfo) { + if (!rcu_access_pointer(ndev->npinfo)) { npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); if (!npinfo) { err = -ENOMEM;