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authorMahesh Bandewar <maheshb@google.com>2019-07-02 23:16:31 -0700
committerDavid S. Miller <davem@davemloft.net>2019-07-03 11:24:38 -0700
commitd62962b37cebdc936e2bfcd69ea685da2c433727 (patch)
tree125dc85e5fb0edf767edf12f2e25bf98de66c7eb
parentdbcdb61aaf1add3fb15f24f7fcbf30c17d5c11db (diff)
downloadlinux-d62962b37cebdc936e2bfcd69ea685da2c433727.tar.bz2
loopback: fix lockdep splat
dev_init_scheduler() and dev_activate() expect the caller to hold RTNL. Since we don't want blackhole device to be initialized per ns, we are initializing at init. [ 3.855027] Call Trace: [ 3.855034] dump_stack+0x67/0x95 [ 3.855037] lockdep_rcu_suspicious+0xd5/0x110 [ 3.855044] dev_init_scheduler+0xe3/0x120 [ 3.855048] ? net_olddevs_init+0x60/0x60 [ 3.855050] blackhole_netdev_init+0x45/0x6e [ 3.855052] do_one_initcall+0x6c/0x2fa [ 3.855058] ? rcu_read_lock_sched_held+0x8c/0xa0 [ 3.855066] kernel_init_freeable+0x1e5/0x288 [ 3.855071] ? rest_init+0x260/0x260 [ 3.855074] kernel_init+0xf/0x180 [ 3.855076] ? rest_init+0x260/0x260 [ 3.855078] ret_from_fork+0x24/0x30 Fixes: 4de83b88c66 ("loopback: create blackhole net device similar to loopack.") Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Mahesh Bandewar <maheshb@google.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/loopback.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
index 3b39def5471e..14545a8797a8 100644
--- a/drivers/net/loopback.c
+++ b/drivers/net/loopback.c
@@ -261,8 +261,10 @@ static int __init blackhole_netdev_init(void)
if (!blackhole_netdev)
return -ENOMEM;
+ rtnl_lock();
dev_init_scheduler(blackhole_netdev);
dev_activate(blackhole_netdev);
+ rtnl_unlock();
blackhole_netdev->flags |= IFF_UP | IFF_RUNNING;
dev_net_set(blackhole_netdev, &init_net);