Re: [PATCH v2 net-next 5/7] rtnetlink: protect handler table with rcu
flat view
From: Ido Schimmel <hidden>
Date: 2017-08-10 08:26:52
On Wed, Aug 09, 2017 at 08:41:51PM +0200, Florian Westphal wrote:
Note that netlink dumps still acquire rtnl mutex via the netlink dump infrastructure. Signed-off-by: Florian Westphal <fw@strlen.de> Reviewed-by: Hannes Frederic Sowa <redacted>
Florian, can you please check the following splat? I didn't bisect, but looks like it's related to this patch. Thanks [ 2.940093] ============================= [ 2.944145] WARNING: suspicious RCU usage [ 2.948147] 4.13.0-rc4-idosch-next-custom #565 Not tainted [ 2.954116] ----------------------------- [ 2.958113] net/core/rtnetlink.c:175 suspicious rcu_dereference_check() usage! [ 2.965116] [ 2.965116] other info that might help us debug this: [ 2.965116] [ 2.973123] [ 2.973123] rcu_scheduler_active = 1, debug_locks = 1 [ 2.979119] no locks held by swapper/0/1. [ 2.983109] [ 2.983109] stack backtrace: [ 2.988117] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.13.0-rc4-idosch-next-custom #565 [ 2.989000] Hardware name: Mellanox Technologies Ltd. Mellanox switch/Mellanox switch, BIOS 4.6.5 05/21/2015 [ 2.989000] Call Trace: [ 2.989000] dump_stack+0xb1/0x10c [ 2.989000] ? _atomic_dec_and_lock+0x124/0x124 [ 2.989000] ? lockdep_print_held_locks+0x9b/0xf0 [ 2.989000] lockdep_rcu_suspicious+0xdd/0x110 [ 2.989000] __rtnl_register+0x1c1/0x320 [ 2.989000] ? rtnetlink_bind+0x50/0x50 [ 2.989000] ? net_defaults_init+0x29/0x29 [ 2.989000] rtnl_register+0x11/0x30 [ 2.989000] net_ns_init+0x1bd/0x1fd [ 2.989000] ? net_defaults_init+0x29/0x29 [ 2.989000] ? __init_srcu_struct+0x54/0x60 [ 2.989000] ? srcu_init_notifier_head+0x4a/0x80 [ 2.989000] do_one_initcall+0x9a/0x241 [ 2.989000] ? initcall_blacklisted+0x140/0x140 [ 2.989000] ? up_read+0x40/0x40 [ 2.989000] ? _raw_spin_unlock_irqrestore+0x3d/0x60 [ 2.989000] ? __wake_up+0x3f/0x50 [ 2.989000] kernel_init_freeable+0x3ea/0x485 [ 2.989000] ? rest_init+0x100/0x100 [ 2.989000] kernel_init+0xe/0x140 [ 2.989000] ? rest_init+0x100/0x100 [ 2.989000] ? rest_init+0x100/0x100 [ 2.989000] ret_from_fork+0x27/0x40