Messages in this thread Patch in this message | | | Date | Thu, 3 Feb 2011 17:12:27 +0800 | From | Yong Zhang <> | Subject | Re: Regression: WARNINGS and lockdep spews in 2.6.38-rc3+ (bisected). |
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Hi Nick,
Thanks for reporting this. Could you please try below patch?
Thanks, Yong
--- From: Yong Zhang <yong.zhang0@gmail.com> Subject: [PATCH] timer: use _local_bh_enable() in del_timer_sync()
Nick Bowler reported: ================================= [ INFO: inconsistent lock state ] 2.6.38-rc3-bisect-00062-g8c007a1 #92 --------------------------------- inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage. swapper/0 [HC1[1]:SC0[0]:HE0:SE1] takes: (&(&dev->event_lock)->rlock){?.+...}, at: [<ffffffff8125def6>] input_event+0x41/0x83 {HARDIRQ-ON-W} state was registered at: [<ffffffff810656d4>] mark_held_locks+0x52/0x70 [<ffffffff8106593a>] trace_hardirqs_on_caller+0xf7/0x135 [<ffffffff81065985>] trace_hardirqs_on+0xd/0xf [<ffffffff81044ac2>] __do_softirq+0x62/0x160 [<ffffffff8100395c>] call_softirq+0x1c/0x28 [<ffffffff81044cf2>] _local_bh_enable_ip+0xb3/0xe3 [<ffffffff81044d3a>] local_bh_enable+0xd/0xf [<ffffffff8104a418>] del_timer_sync+0x4f/0x8e [<ffffffffa00947fe>] rfkill_schedule_global_op+0x41/0x84 [rfkill] [<ffffffffa0094858>] rfkill_schedule_evsw_rfkillall+0x17/0x19 [rfkill] [<ffffffffa009495f>] rfkill_event+0x58/0x5a [rfkill] [<ffffffff8125c980>] input_pass_event+0x97/0xea [<ffffffff8125de13>] input_handle_event+0x460/0x46f [<ffffffff8125df1b>] input_event+0x66/0x83 [<ffffffffa009becb>] tpacpi_send_radiosw_update+0x7f/0xc4 [thinkpad_acpi] [<ffffffffa009c417>] hotkey_notify+0x507/0x581 [thinkpad_acpi] [<ffffffffa009b029>] dispatch_acpi_notify+0x29/0x2b [thinkpad_acpi] [<ffffffff8119a18a>] acpi_ev_notify_dispatch+0x62/0x7c [<ffffffff8118b323>] acpi_os_execute_deferred+0x24/0x31 [<ffffffff810511bf>] process_one_work+0x204/0x33b [<ffffffff81053384>] worker_thread+0x136/0x255 [<ffffffff810566da>] kthread+0x7d/0x85 [<ffffffff81003864>] kernel_thread_helper+0x4/0x10 irq event stamp: 559266 hardirqs last enabled at (559263): [<ffffffff811b40a5>] acpi_idle_enter_bm+0x236/0x275 hardirqs last disabled at (559264): [<ffffffff812ffd6a>] save_args+0x6a/0x70 softirqs last enabled at (559266): [<ffffffff81044bce>] _local_bh_enable+0xe/0x10 softirqs last disabled at (559265): [<ffffffff81044c0d>] irq_enter+0x3d/0x6f
other info that might help us debug this: 1 lock held by swapper/0: #0: (&serio->lock){-.-...}, at: [<ffffffff81259018>] serio_interrupt+0x24/0x7e
stack backtrace: Pid: 0, comm: swapper Tainted: G W 2.6.38-rc3-bisect-00062-g8c007a1 #92 Call Trace: <IRQ> [<ffffffff81065442>] ? valid_state+0x17e/0x191 [<ffffffff8100e159>] ? save_stack_trace+0x28/0x45 [<ffffffff81065d18>] ? check_usage_forwards+0x0/0x87 [<ffffffff81065568>] ? mark_lock+0x113/0x22d [<ffffffff8106687f>] ? __lock_acquire+0x2ac/0xd01 [<ffffffff81065482>] ? mark_lock+0x2d/0x22d [<ffffffff81065482>] ? mark_lock+0x2d/0x22d [<ffffffff81065482>] ? mark_lock+0x2d/0x22d [<ffffffff81067338>] ? lock_acquire+0x64/0x81 [<ffffffff8125def6>] ? input_event+0x41/0x83 [<ffffffff812ff378>] ? _raw_spin_lock_irqsave+0x53/0x65 [<ffffffff8125def6>] ? input_event+0x41/0x83 [<ffffffff8125def6>] ? input_event+0x41/0x83 [<ffffffff81261fb6>] ? atkbd_interrupt+0x9a/0x574 [<ffffffff81259034>] ? serio_interrupt+0x40/0x7e [<ffffffff8125a31c>] ? i8042_interrupt+0x28e/0x2a8 [<ffffffff8107e834>] ? handle_IRQ_event+0x20/0xae [<ffffffff810805e6>] ? handle_edge_irq+0xde/0x12a [<ffffffff810055c9>] ? handle_irq+0x1f/0x2a [<ffffffff81004c37>] ? do_IRQ+0x48/0xaf [<ffffffff812ffe13>] ? ret_from_intr+0x0/0x1a <EOI> [<ffffffff8100a1aa>] ? native_sched_clock+0x2d/0x5f [<ffffffff811b40ac>] ? acpi_idle_enter_bm+0x23d/0x275 [<ffffffff811b40a5>] ? acpi_idle_enter_bm+0x236/0x275 [<ffffffff8126c2ae>] ? cpuidle_idle_call+0x9f/0xd5 [<ffffffff81001e75>] ? cpu_idle+0x61/0xaa [<ffffffff812ecdc9>] ? rest_init+0xcd/0xd4 [<ffffffff812eccfc>] ? rest_init+0x0/0xd4 [<ffffffff81682d3d>] ? start_kernel+0x3a6/0x3b1 [<ffffffff816822b1>] ? x86_64_start_reservations+0xb8/0xbc [<ffffffff816823bb>] ? x86_64_start_kernel+0x106/0x115
The cause is that local_bh_enable() could call do_softirq() in certain time, thus break irq status and make lock bite us.
Reported-and-bisected-by: Nick Bowler <nbowler@elliptictech.com> Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> --- kernel/timer.c | 7 ++++++- 1 files changed, 6 insertions(+), 1 deletions(-)
diff --git a/kernel/timer.c b/kernel/timer.c index 43ca993..253aefe 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -969,10 +969,15 @@ EXPORT_SYMBOL(try_to_del_timer_sync); int del_timer_sync(struct timer_list *timer) { #ifdef CONFIG_LOCKDEP + unsigned long flags; + local_bh_disable(); lock_map_acquire(&timer->lockdep_map); lock_map_release(&timer->lockdep_map); - local_bh_enable(); + /* raw_local_irq_[save|restore] is to protect _local_bh_enable() */ + raw_local_irq_save(flags); + _local_bh_enable(); + raw_local_irq_restore(flags); #endif /* * don't use it in hardirq context, because it -- 1.7.1
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