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| author | Lai Jiangshan <laijs@cn.fujitsu.com> | 2010-03-16 17:00:29 +0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2010-03-16 10:10:40 +0100 |
| commit | 7f5b774275df8c76a959eae7488128b637fcbfc8 (patch) | |
| tree | cf6526c53c319f78e4209ada6017e0c735b987eb /include | |
| parent | e3818b8dce2a934cd1521dbc4827e5238d8f45d8 (diff) | |
| download | linux-0-day-7f5b774275df8c76a959eae7488128b637fcbfc8.tar.gz linux-0-day-7f5b774275df8c76a959eae7488128b637fcbfc8.tar.xz | |
rcu: Fix tracepoints & lockdep false positive
tracepoint.h uses rcu_dereference(), which triggers this warning:
[ 0.701161] ===================================================
[ 0.702211] [ INFO: suspicious rcu_dereference_check() usage. ]
[ 0.702716] ---------------------------------------------------
[ 0.703203] include/trace/events/workqueue.h:68 invoked rcu_dereference_check() without protection!
[ 0.703971] [ 0.703990] other info that might help us debug this:
[ 0.703993]
[ 0.705590]
[ 0.705604] rcu_scheduler_active = 1, debug_locks = 0
[ 0.706712] 1 lock held by swapper/1:
[ 0.707229] #0: (cpu_add_remove_lock){+.+.+.}, at: [<c0142f54>] cpu_maps_update_begin+0x14/0x20
[ 0.710097]
[ 0.710106] stack backtrace:
[ 0.712602] Pid: 1, comm: swapper Not tainted 2.6.34-rc1-tip-01613-g72662bb #168
[ 0.713231] Call Trace:
[ 0.713997] [<c017174d>] lockdep_rcu_dereference+0x9d/0xb0
[ 0.714746] [<c015a117>] create_workqueue_thread+0x107/0x110
[ 0.715353] [<c015aee0>] ? worker_thread+0x0/0x340
[ 0.715845] [<c015a8e8>] __create_workqueue_key+0x138/0x240
[ 0.716427] [<c0142f92>] ? cpu_maps_update_done+0x12/0x20
[ 0.717012] [<c086b12f>] init_workqueues+0x6f/0x80
[ 0.717530] [<c08576d2>] kernel_init+0x102/0x1f0
[ 0.717570] [<c08575d0>] ? kernel_init+0x0/0x1f0
[ 0.718944] [<c01030fa>] kernel_thread_helper+0x6/0x10
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4B9F48AD.4000404@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/tracepoint.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index f59604ed0ec60..78b4bd3be496c 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -49,7 +49,7 @@ struct tracepoint { void **it_func; \ \ rcu_read_lock_sched_notrace(); \ - it_func = rcu_dereference((tp)->funcs); \ + it_func = rcu_dereference_sched((tp)->funcs); \ if (it_func) { \ do { \ ((void(*)(proto))(*it_func))(args); \ |