Messages in this thread | | | Date | Fri, 24 Apr 2009 17:55:09 +1000 | From | Stephen Rothwell <> | Subject | Re: Next April 24 : BUG: lock held at task exit time! |
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Hi Sachin,
On Fri, 24 Apr 2009 12:25:41 +0530 Sachin Sant <sachinp@in.ibm.com> wrote: > > While booting today's next tree on a powerpc box [ power 6 blade] > observed the following : > > khelper used greatest stack depth: 10176 bytes left > > ===================================== > [ BUG: lock held at task exit time! ] > ------------------------------------- > khelper/21 is exiting with locks still held! > 2 locks held by khelper/21: > #0: (rcu_read_lock){.+.+.+}, at: [<c0000000001382fc>] > .check_unsafe_exec+0x44/0x148 > #1: (rcu_read_lock){.+.+.+}, at: [<c000000000138368>] > .check_unsafe_exec+0xb0/0x148 > > stack backtrace: > Call Trace: > [c000000044483cf0] [c000000000011a54] .show_stack+0x6c/0x16c (unreliable) > [c000000044483da0] [c00000000009ae14] .debug_check_no_locks_held+0x98/0xb4 > [c000000044483e20] [c000000000073b1c] .do_exit+0x758/0x7b0 > [c000000044483f00] [c0000000000853d8] .____call_usermodehelper+0x170/0x174 > [c000000044483f90] [c00000000002bd8c] .kernel_thread+0x54/0x70 > net_namespace: 2000 bytes > > Complete dmesg attached. Let me know if you need any other info. I will > try yesterday's next > tree to check if this problem can be recreated.
Almost certainly commit 874a9e18f25c86dbc199ad32ddd9ca44d25290e8 ("check_unsafe_exec: s/lock_task_sighand/rcu_read_lock/") which has a typo (two locks instead of lock/unlock) as pointed out by Hugh Dickins (<Pine.LNX.4.64.0904240526080.15735@blonde.anvils> on LKML).
-- Cheers, Stephen Rothwell sfr@canb.auug.org.au http://www.canb.auug.org.au/~sfr/ [unhandled content-type:application/pgp-signature] | |