lkml.org 
[lkml]   [2022]   [Jun]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe:Re: [PATCH] arch: x86: kernel: Add missing of_node_put() in devicetree.c


Hi, rob, thanks for your reply.

The of_find_xx will increase the refcounter for the local reference, so when
the function return, we need a decrease for the destroy of the local reference.
The device will not be freed as its refcounter will be sure larger than 0 when
the function returns.

All we need is to keep the refcounting balance, right?




At 2022-06-16 00:26:16, "Rob Herring" <robh@kernel.org> wrote:
>On Wed, Jun 15, 2022 at 9:03 AM Liang He <windhl@126.com> wrote:
>>
>> In dtb_setup_hpet(), of_find_compatible_node() will return a node
>> pointer with refcount incremented. We should use of_node_put() when it
>> is not used anymore.
>>
>> Signed-off-by: Liang He <windhl@126.com>
>> ---
>> arch/x86/kernel/devicetree.c | 3 +++
>> 1 file changed, 3 insertions(+)
>>
>> diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c
>> index 5cd51f25f446..6a386424ddf7 100644
>> --- a/arch/x86/kernel/devicetree.c
>> +++ b/arch/x86/kernel/devicetree.c
>> @@ -120,6 +120,9 @@ static void __init dtb_setup_hpet(void)
>> if (!dn)
>> return;
>> ret = of_address_to_resource(dn, 0, &r);
>> +
>> + of_node_put(dn);
>> +
>
>You don't want a put on success. If you are using the device, then you
>want to hold a reference to it.
>
>I would guess that if you have an error here and don't have your
>timer, you're not going to finish booting anyways.
>
>Finally, wouldn't dtb_lapic_setup() and dtb_add_ioapic() also need a
>similar change? But again, if those aren't initialized, you probably
>aren't getting very far.
>
>
>> if (ret) {
>> WARN_ON(1);
>> return;
>> --
>> 2.25.1
>>
\
 
 \ /
  Last update: 2022-06-15 18:52    [W:1.871 / U:0.008 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site