Messages in this thread | | | Date | Fri, 22 Nov 2013 17:31:46 +0100 | From | Daniel Lezcano <> | Subject | Re: [PATCH] clocksource: Do not drop unheld reference on device node |
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On 11/22/2013 05:16 PM, Thierry Reding wrote: > On Sat, Oct 19, 2013 at 12:49:48AM +0200, Thierry Reding wrote: >> When booting a recent kernel on ARM with OF_DYNAMIC enabled, the kernel >> warns about the following: >> >> [ 0.000000] ERROR: Bad of_node_put() on /timer@50004600 >> [ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.12.0-rc5-next-20131017-00077-gedfd827-dirty #406 >> [ 0.000000] [<c0015b68>] (unwind_backtrace+0x0/0xf4) from [<c00117e4>] (show_stack+0x10/0x14) >> [ 0.000000] [<c00117e4>] (show_stack+0x10/0x14) from [<c055f734>] (dump_stack+0x9c/0xc8) >> [ 0.000000] [<c055f734>] (dump_stack+0x9c/0xc8) from [<c03b47d4>] (of_node_release+0x90/0x9c) >> [ 0.000000] [<c03b47d4>] (of_node_release+0x90/0x9c) from [<c03b5084>] (of_find_matching_node_and_match+0x78/0xb4) >> [ 0.000000] [<c03b5084>] (of_find_matching_node_and_match+0x78/0xb4) from [<c07887c8>] (clocksource_of_init+0x60/0x70) >> [ 0.000000] [<c07887c8>] (clocksource_of_init+0x60/0x70) from [<c076e99c>] (start_kernel+0x1f4/0x33c) >> [ 0.000000] [<c076e99c>] (start_kernel+0x1f4/0x33c) from [<80008074>] (0x80008074) >> >> This is caused by clocksource_of_init() dropping a reference on the >> device node that it never took. The reference taken by the loop is >> implicitly dropped on subsequent iterations. See the implementation of >> and the comment on top of the of_find_matching_node_and_match() >> function for reference (no pun intended). >> >> Signed-off-by: Thierry Reding <treding@nvidia.com> >> --- >> drivers/clocksource/clksrc-of.c | 1 - >> 1 file changed, 1 deletion(-) > > Can someone look at this?
Yes. Sounds like I missed it.
This regression has been introduced by:
commit 326e31eebe61dc838e031ea16968b2cfb43443e3 Author: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Date: Tue Oct 1 11:00:53 2013 +0200
clocksource: Put nodes passed to CLOCKSOURCE_OF_DECLARE callbacks centrally
Instead of letting each driver call of_node_put do it centrally in the loop that also calls the CLOCKSOURCE_OF_DECLARE callbacks. This is less prone to error and also moves getting and putting the references into the same function.
Consequently all respective of_node_put calls in drivers are removed.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: David Brown <davidb@codeaurora.org>
>> diff --git a/drivers/clocksource/clksrc-of.c b/drivers/clocksource/clksrc-of.c >> index 35639cf4..b9ddd9e 100644 >> --- a/drivers/clocksource/clksrc-of.c >> +++ b/drivers/clocksource/clksrc-of.c >> @@ -35,6 +35,5 @@ void __init clocksource_of_init(void) >> >> init_func = match->data; >> init_func(np); >> - of_node_put(np); >> } >> } >> -- >> 1.8.4 >>
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