Re: [PATCH v2 1/2] ras: fix an off-by-one error in __find_elem()

[Cong Wang]

On Sat, Apr 20, 2019 at 12:04 PM Borislav Petkov <bp@xxxxxxxxx> wrote:
>
> On Sat, Apr 20, 2019 at 11:25:43AM -0700, Cong Wang wrote:
> > If you want to go that far, you can choose to use lib/bsearch.c too in
> > case you want to reinvent the wheel.
>
> Well, that doesn't give me the @to functionality which points to the
> slot where the new element should be inserted, when the search was
> unsuccessful.

No one stops you from adding it, as you are going far you can always
go further. :)


>
> > What's your point here?
>
> My point is to fix it properly. Obviously.

Of course, no one can stop you from rewriting the whole ras code by
doing it properly.


>
> > You know my fix is targeted for -stable,
>
> Well, first you sent me this:
>
> https://lkml.kernel.org/r/20190416012001.5338-1-xiyou.wangcong@xxxxxxxxx
>
> then this:
>
> https://lkml.kernel.org/r/20190416213351.28999-1-xiyou.wangcong@xxxxxxxxx


Yes, one is V1 and the other is V2. Is it hard to understand V2 is to replace
V1?


>
> Tony liked this second version more and if you look at the final result of mine:


Sorry, I have no reason to look into a 83-line change.


> it has basically *both*: the correct [min:max] range *and* the return of
> ithe ndex when found. But the algorithm this time is the correct one.

I don't review it, so I don't know. Feel free to believe you are correct here,
until someone finds a bug later.


>
> > I doubt your 83-line change could fit for -stable.
>
> My 83-line change has debug output only for experimentation. It will,
> *of* *course* be removed before committing it upstream. That's why I
> called it "a conglomerate patch" and I said "It has some debug output
> for easier debugging, that will be removed in the final version, of
> course." I guess you didn't read that either.

Why should I read a debugging patch?


>
> And the sanity_check() piece will be a separate patch, of course.
>
> In the end the diffstat will be 30-40 lines max.
>
> > Feel free to drop my patch to favor yours. I am really tired.
>
> Suit yourself. Thanks for the reporting.

There is no bug here, your code is perfect. :) Sorry for wasting
your time to believe this it is bug, it is not. :-)

Thanks.