• Ingo Molnar's avatar
    [PATCH] lockdep: fix static keys in module-allocated percpu areas · 1ff56830
    Ingo Molnar authored
    lockdep got confused by certain locks in modules:
    
     INFO: trying to register non-static key.
     the code is fine but needs lockdep annotation.
     turning off the locking correctness validator.
    
     Call Trace:
      [<ffffffff8026f40d>] dump_trace+0xaa/0x3f2
      [<ffffffff8026f78f>] show_trace+0x3a/0x60
      [<ffffffff8026f9d1>] dump_stack+0x15/0x17
      [<ffffffff802abfe8>] __lock_acquire+0x724/0x9bb
      [<ffffffff802ac52b>] lock_acquire+0x4d/0x67
      [<ffffffff80267139>] rt_spin_lock+0x3d/0x41
      [<ffffffff8839ed3f>] :ip_conntrack:__ip_ct_refresh_acct+0x131/0x174
      [<ffffffff883a1334>] :ip_conntrack:udp_packet+0xbf/0xcf
      [<ffffffff8839f9af>] :ip_conntrack:ip_conntrack_in+0x394/0x4a7
      [<ffffffff8023551f>] nf_iterate+0x41/0x7f
      [<ffffffff8025946a>] nf_hook_slow+0x64/0xd5
      [<ffffffff802369a2>] ip_rcv+0x24e/0x506
      [...]
    
    Steven Rostedt found the bug: static_obj() check did not take
    PERCPU_ENOUGH_ROOM into account, so in-module DEFINE_PER_CPU-area locks
    were triggering this message.
    Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
    Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
    1ff56830
lockdep.c 68.1 KB