BUG: warning at kernel/cpu.c:51/unlock_cpu_hotplug() - 2.6.18.6

BUG: warning at kernel/cpu.c:51/unlock_cpu_hotplug() - 2.6.18.6

[Antoine Martin]

I just caught this in the log whilst running some unit tests.
(the test was in the process of starting 900 Java threads)

audit(1171565587.887:96): enforcing=0 old_enforcing=1 auid=4294967295
BUG: warning at kernel/cpu.c:51/unlock_cpu_hotplug()

Call Trace:
  [<ffffffff80269c98>] dump_stack+0x12/0x17
  [<ffffffff8029dfe6>] unlock_cpu_hotplug+0x3f/0x6c
  [<ffffffff802876b6>] sched_getaffinity+0x7d/0xa2
  [<ffffffff80287701>] sys_sched_getaffinity+0x26/0x55
  [<ffffffff8025cb0e>] system_call+0x7e/0x83
DWARF2 unwinder stuck at system_call+0x7e/0x83
Leftover inexact backtrace:

audit(1171579693.653:97): avc:  denied  { connectto } for  pid=9211 
comm="mount" name=".setrans-unix" scontext=system_u:system_r:mount_t:s0 
tcontext=system_u:system_r:initrc_t:s0 tclass=unix_stream_socket
kjournald starting.  Commit interval 5 seconds
EXT3 FS on sdb3, internal journal
EXT3-fs: mounted filesystem with ordered data mode.
SELinux: initialized (dev sdb3, type ext3), uses xattr

Re: BUG: warning at kernel/cpu.c:51/unlock_cpu_hotplug() - 2.6.18.6

[Gautham R Shenoy]

Hi Antoine,

On Thu, Feb 15, 2007 at 08:59:05PM +0000, Antoine Martin wrote:
> I just caught this in the log whilst running some unit tests.
> (the test was in the process of starting 900 Java threads)
> 
> audit(1171565587.887:96): enforcing=0 old_enforcing=1 auid=4294967295
> BUG: warning at kernel/cpu.c:51/unlock_cpu_hotplug()
> 
> Call Trace:
>  [<ffffffff80269c98>] dump_stack+0x12/0x17
>  [<ffffffff8029dfe6>] unlock_cpu_hotplug+0x3f/0x6c
>  [<ffffffff802876b6>] sched_getaffinity+0x7d/0xa2
>  [<ffffffff80287701>] sys_sched_getaffinity+0x26/0x55
>  [<ffffffff8025cb0e>] system_call+0x7e/0x83

Looks like one of those spurious unlock_cpu_hotplug warnings.

Let me know if this fix works for you or not. 

regards
gautham.

Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>

 kernel/cpu.c |    2 +-
 1 files changed, 1 insertion(+), 1 deletion(-)

Index: linux-2.6.18/kernel/cpu.c
===================================================================
--- linux-2.6.18.orig/kernel/cpu.c
+++ linux-2.6.18/kernel/cpu.c
@@ -53,8 +53,8 @@ void unlock_cpu_hotplug(void)
 		recursive_depth--;
 		return;
 	}
-	mutex_unlock(&cpu_bitmask_lock);
 	recursive = NULL;
+	mutex_unlock(&cpu_bitmask_lock);
 }
 EXPORT_SYMBOL_GPL(unlock_cpu_hotplug);
 
-- 
Gautham R Shenoy
Linux Technology Center
IBM India.
"Freedom comes with a price tag of responsibility, which is still a bargain,
because Freedom is priceless!"