On Wed, Sep 7, 2022 at 3:50 PM Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> wrote: > > On Tue, Sep 06, 2022 at 04:11:58PM -0700, Eric Dumazet wrote: > > > > WRITE_ONCE(sysctl_tcp_authopt, val), or even better: > > > > if (val) > > cmpxchg(&sysctl_tcp_authopt, 0, val); > > What's the point of the cmpxchg? Since you're simply trying to prevent > sysctl_tcp_authopt from going back to zero, then the if clause > by itself is enough: > > if (val) > WRITE_ONCE(sysctl_tcp_authopt, val); > Ack. Original patch was doing something racy, I have not though about the most efficient way to deal with it.
