linux-kernel - Re: [PATCH 1/3] ACPI: fix incorrect counts returned by acpi_parse_entries

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Date:	Fri, 1 Jul 2016 16:38:42 -0600
From:	Al Stone <ahs3@...hat.com>
To:	"Rafael J. Wysocki" <rafael@...nel.org>
Cc:	ACPI Devel Maling List <linux-acpi@...r.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	"Rafael J . Wysocki" <rjw@...ysocki.net>,
	Len Brown <lenb@...nel.org>
Subject: Re: [PATCH 1/3] ACPI: fix incorrect counts returned by
 acpi_parse_entries_array()

On 07/01/2016 03:56 PM, Rafael J. Wysocki wrote:
> On Fri, Jul 1, 2016 at 11:50 PM, Al Stone <ahs3@...hat.com> wrote:
>> On 07/01/2016 03:44 PM, Rafael J. Wysocki wrote:
>>> On Fri, Jul 1, 2016 at 11:36 PM, Al Stone <ahs3@...hat.com> wrote:
>>>> On 07/01/2016 03:25 PM, Rafael J. Wysocki wrote:
>>>>> On Fri, Jul 1, 2016 at 11:21 PM, Al Stone <ahs3@...hat.com> wrote:
>>>>>> The static function acpi_parse_entries_array() is provided an array of
>>>>>> type struct acpi_subtable_proc that has a callback function and a count.
>>>>>> The count should reflect how many times the callback has been successfully
>>>>>> called.  However, the current code only increments the 0th element of the
>>>>>> array, regardless of the number of entries in the array, or which callback
>>>>>> has been invoked.  The fix is to use the index into the array, instead of
>>>>>> a pointer to the beginning of the array.
>>>>>
>>>>> OK, so it would be good to say what the consequences of the problem are too.
>>>>>
>>>>
>>>> Hrm.  So replace the last sentence with something like:
>>>>
>>>>    The fix is to use the index into the array, instead of
>>>>    a pointer to the beginning of the array, so that the count
>>>>    for each element in the array in incremented by the
>>>>    corresponding callback.
>>>>
>>>> That feels a little clunky but is it closer to what you were
>>>> thinking?
>>>
>>> Well, not really.
>>>
>>> The code is arguably incorrect, but is there anything that does not
>>> work as expected as a result?  Any functional breakage?  Any
>>> misleading messages printed?
>>>
>>
>> That's the odd thing; there is no breakage.  Of any sort.
>>
>> But, no one relies on those values for anything at this point.  I've got a
>> couple of ideas I'm working on that are easier if it does work right, however.
> 
> That's information that should go into the changelog too.
> 
> "There are no functional consequences of the issue, but fixing it is
> necessary for future work."
> 
> Or similar.
> 

Will do in v2.

-- 
ciao,
al
-----------------------------------
Al Stone
Software Engineer
Red Hat, Inc.
ahs3@...hat.com
-----------------------------------