On 2017-01-24 01:24, qhou wrote:
>
> On 2017年01月24日 00:27, Peter Rosin wrote:
>> On 2017-01-23 11:40, Qi Hou wrote:
>>> During stepping down the tree, parent node is gotten first and its refcount is
>>> increased with of_node_get() in __of_get_next_child(). Since it just being used
>>> as step node, its refcount must be decreased with of_node_put() after traversing
>>> its child nodes.
>>>
>>> Or, its refcount will never be descreased to ZERO, then it will never be freed,
>>> as well as other related memory blocks.
>>>
>>> To fix this, decrease refcount of parent with of_node_put() after
>>> __of_find_node_by_path().
>>>
>>> Signed-off-by: Qi Hou <qi.hou@xxxxxxxxxxxxx>
>>> Acked-by: Peter Rosin <peda@xxxxxxxxxx>
>>> ---
>>> drivers/of/base.c | 4 +++-
>>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/of/base.c b/drivers/of/base.c
>>> index d4bea3c..091ad29 100644
>>> --- a/drivers/of/base.c
>>> +++ b/drivers/of/base.c
>>> @@ -842,8 +842,10 @@ struct device_node *of_find_node_opts_by_path(const char *path, const char **opt
>>> if (!np)
>>> np = of_node_get(of_root);
>>> while (np && *path == '/') {
>>> + struct device_node *npp = np;
>> Hi,
>>
>> You failed to add a blank line here...
> Sorry, I miss it, I will add.
>>> path++; /* Increment past '/' delimiter */
>>> - np = __of_find_node_by_path(np, path);
>>> + np = __of_find_node_by_path(npp, path);
>> ...and there's no need to change the above line if you
>> want to make a minimal change.
> Just want the code readable, as npp is parent and np is a some child of
> parent.
If you go for readable, name the variable 'parent' instead of 'npp'.
But 'prev', 'old', 'last', 'tmp' or something like that would also
work, at least for me. The thing is just a temporary holding space
for the of_node_put call and the fact that it's the parent of 'np'
is kind of irrelevant...
Not my code though, and I don't really care.
Cheers,
peda
> -- Best regards,
> Qi Hou
>>
>> Cheers,
>> peda
>>
>>> + of_node_put(npp);
>>> path = strchrnul(path, '/');
>>> if (separator && separator < path)
>>> break;
>>>
>
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