[lkml]   [2006]   [Nov]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[patch] lockdep: fix static keys in module-allocated percpu areas
Subject: [patch] lockdep: fix static keys in module-allocated percpu areas
From: Ingo Molnar <>

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: Ingo Molnar <>
Signed-off-by: Steven Rostedt <>
kernel/lockdep.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

Index: linux/kernel/lockdep.c
--- linux.orig/kernel/lockdep.c
+++ linux/kernel/lockdep.c
@@ -1083,7 +1083,8 @@ static int static_obj(void *obj)
for_each_possible_cpu(i) {
start = (unsigned long) &__per_cpu_start + per_cpu_offset(i);
- end = (unsigned long) &__per_cpu_end + per_cpu_offset(i);
+ end = (unsigned long) &__per_cpu_start + PERCPU_ENOUGH_ROOM
+ + per_cpu_offset(i);

if ((addr >= start) && (addr < end))
return 1;
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at
 \ /
  Last update: 2006-11-17 20:01    [W:0.034 / U:0.668 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site