1. 21 Jul, 2020 1 commit
    • Jiri Pirko's avatar
      sched: sch_api: add missing rcu read lock to silence the warning · a8b7b2d0
      Jiri Pirko authored
      In case the qdisc_match_from_root function() is called from non-rcu path
      with rtnl mutex held, a suspiciout rcu usage warning appears:
      
      [  241.504354] =============================
      [  241.504358] WARNING: suspicious RCU usage
      [  241.504366] 5.8.0-rc4-custom-01521-g72a7c7d549c3 #32 Not tainted
      [  241.504370] -----------------------------
      [  241.504378] net/sched/sch_api.c:270 RCU-list traversed in non-reader section!!
      [  241.504382]
                     other info that might help us debug this:
      [  241.504388]
                     rcu_scheduler_active = 2, debug_locks = 1
      [  241.504394] 1 lock held by tc/1391:
      [  241.504398]  #0: ffffffff85a27850 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x49a/0xbd0
      [  241.504431]
                     stack backtrace:
      [  241.504440] CPU: 0 PID: 1391 Comm: tc Not tainted 5.8.0-rc4-custom-01521-g72a7c7d549c3 #32
      [  241.504446] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-2.fc32 04/01/2014
      [  241.504453] Call Trace:
      [  241.504465]  dump_stack+0x100/0x184
      [  241.504482]  lockdep_rcu_suspicious+0x153/0x15d
      [  241.504499]  qdisc_match_from_root+0x293/0x350
      
      Fix this by passing the rtnl held lockdep condition down to
      hlist_for_each_entry_rcu()
      Reported-by: default avatarIdo Schimmel <idosch@mellanox.com>
      Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      a8b7b2d0
  2. 20 Jul, 2020 39 commits