Re: [PATCH] of: Fix issue where code would fall through to error case.

From: Frank Rowand
Date: Sat Nov 26 2016 - 16:40:40 EST


On 11/23/16 13:58, Rob Herring wrote:
> On Thu, Nov 17, 2016 at 6:10 PM, Moritz Fischer
> <moritz.fischer.private@xxxxxxxxx> wrote:
>> On Thu, Nov 17, 2016 at 4:02 PM, Frank Rowand <frowand.list@xxxxxxxxx> wrote:
>>> On 11/17/16 15:40, Frank Rowand wrote:
>>>> On 11/17/16 15:25, Moritz Fischer wrote:
>>>>> No longer fall through into the error case that prints out
>>>>> an error if no error (err = 0) occurred.
>>>>>
>>>>> Fixes d9181b20a83(of: Add back an error message, restructured)
>>>>> Signed-off-by: Moritz Fischer <moritz.fischer@xxxxxxxxx>
>>>>> ---
>>>>> drivers/of/resolver.c | 6 +++++-
>>>>> 1 file changed, 5 insertions(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/drivers/of/resolver.c b/drivers/of/resolver.c
>>>>> index 783bd09..785076d 100644
>>>>> --- a/drivers/of/resolver.c
>>>>> +++ b/drivers/of/resolver.c
>>>>> @@ -358,9 +358,13 @@ int of_resolve_phandles(struct device_node *overlay)
>>>>>
>>>>> err = update_usages_of_a_phandle_reference(overlay, prop, phandle);
>>>>> if (err)
>>>>> - break;
>>>>> + goto err_out;
>>>>> }
>>>>>
>>>>> + of_node_put(tree_symbols);
>>>>> +
>>>>> + return 0;
>>>>> +
>>>>> err_out:
>>>>> pr_err("overlay phandle fixup failed: %d\n", err);
>>>>> out:
>>>>
>>>> Thanks for catching that.
>>>>
>>>> Rob, please apply.
>>>>
>>>> Reviewed-by: Frank Rowand <frank.rowand@xxxxxxxxxxx>
>>>>
>>>> -Frank
>>>
>>> On second thought, isn't the common pattern when clean up is needed for
>>> both the no-error path and the error path something like:
>>>
>>>
>>> out:
>>> of_node_put(tree_symbols);
>>> return err;
>>>
>>> err_out:
>>> pr_err("overlay phandle fixup failed: %d\n", err);
>>> goto out;
>>> }
>>>
>>>
>>> I don't have a strong opinion, whatever Rob wants to take is fine with me.
>>
>> Same here. I tried to avoid the jumping back part, but if that's the
>> common pattern,
>> I can submit a v2 doing that instead.
>
> Both are ugly. Just do:
>
> if (err)
> pr_err(...);
>
> Rob

Agreed. Thanks for the touch of sanity Rob.

-Frank