Message ID | 1411406513.26859.136.camel@edumazet-glaptop2.roam.corp.google.com |
---|---|
State | Superseded, archived |
Delegated to: | David Miller |
Headers | show |
On Mon, 2014-09-22 at 10:21 -0700, Eric Dumazet wrote: > From: Eric Dumazet <edumazet@google.com> > > this_cpu_ptr() in preemptible context is generally bad > > Sep 22 05:05:55 br kernel: [ 94.608310] BUG: using smp_processor_id() in > preemptible [00000000] code: ip/2261 > Sep 22 05:05:55 br kernel: [ 94.608316] caller is > tunnel_dst_set.isra.28+0x20/0x60 [ip_tunnel] > Sep 22 05:05:55 br kernel: [ 94.608319] CPU: 3 PID: 2261 Comm: ip Not tainted > 3.17.0-rc5 #82 > > We can simply use __this_cpu_ptr(), as preemption is safe in these contexts. > > Should fix https://bugzilla.kernel.org/show_bug.cgi?id=84991 > > Signed-off-by: Eric Dumazet <edumazet@google.com> > Reported-by: Joe <joe9mail@gmail.com> > Fixes: 9a4aa9af447f ("ipv4: Use percpu Cache route in IP tunnels") > --- Hmm, I just saw raw_cpu_ptr() should be used. I'll send a v2 -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c index afed1aac2638..421b4f01ee29 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -82,7 +82,7 @@ static void __tunnel_dst_set(struct ip_tunnel_dst *idst, static void tunnel_dst_set(struct ip_tunnel *t, struct dst_entry *dst, __be32 saddr) { - __tunnel_dst_set(this_cpu_ptr(t->dst_cache), dst, saddr); + __tunnel_dst_set(__this_cpu_ptr(t->dst_cache), dst, saddr); } static void tunnel_dst_reset(struct ip_tunnel *t) @@ -106,7 +106,7 @@ static struct rtable *tunnel_rtable_get(struct ip_tunnel *t, struct dst_entry *dst; rcu_read_lock(); - idst = this_cpu_ptr(t->dst_cache); + idst = __this_cpu_ptr(t->dst_cache); dst = rcu_dereference(idst->dst); if (dst && !atomic_inc_not_zero(&dst->__refcnt)) dst = NULL;