Without the rwlock and with PREEMPT_RCU we're no longer guaranteed to be
in non-preemptible context when performing a route lookup, so use
raw_cpu_ptr() instead.
Takes care of the following splat:
[ 122.221814] BUG: using smp_processor_id() in preemptible [00000000] code:
sshd/2672
[ 122.221845] caller is debug_smp_processor_id+0x17/0x20
[ 122.221866] CPU: 0 PID: 2672 Comm: sshd Not tainted
4.14.0-rc3-idosch-next-custom #639
[ 122.221880] Hardware name: Mellanox Technologies Ltd.
MSN2100-CB2FO/SA001017, BIOS 5.6.5 06/07/2016
[ 122.221893] Call Trace:
[ 122.221919] dump_stack+0xb1/0x10c
[ 122.221946] ? _atomic_dec_and_lock+0x124/0x124
[ 122.221974] ? ___ratelimit+0xfe/0x240
[ 122.222020] check_preemption_disabled+0x173/0x1b0
[ 122.222060] debug_smp_processor_id+0x17/0x20
[ 122.222083] ip6_pol_route+0x1482/0x24a0
...
Fixes: 66f5d6ce53e6 ("ipv6: replace rwlock with rcu and spinlock in fib6_table")
Signed-off-by: Ido Schimmel <[email protected]>
---
net/ipv6/route.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 399d1bceec4a..579d4b73beb1 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1112,7 +1112,7 @@ static struct rt6_info *rt6_get_pcpu_route(struct
rt6_info *rt)
{
struct rt6_info *pcpu_rt, **p;
- p = this_cpu_ptr(rt->rt6i_pcpu);
+ p = raw_cpu_ptr(rt->rt6i_pcpu);
pcpu_rt = *p;
if (pcpu_rt && ip6_hold_safe(NULL, &pcpu_rt, false))
@@ -1134,7 +1134,7 @@ static struct rt6_info *rt6_make_pcpu_route(struct
rt6_info *rt)
}
dst_hold(&pcpu_rt->dst);
- p = this_cpu_ptr(rt->rt6i_pcpu);
+ p = raw_cpu_ptr(rt->rt6i_pcpu);
prev = cmpxchg(p, NULL, pcpu_rt);
if (prev) {
/* If someone did it before us, return prev instead */
--
2.13.6
