Re: [PATCH v2 03/15] NTB: Fix UB/bug in ntb_mw_get_align()

Jon Mason
2017-12-05T17:08:28Z

On Tue, Dec 5, 2017 at 12:01 PM, Logan Gunthorpe <logang@deltatee.com> wrote:
>
>
> On 05/12/17 09:52 AM, Jon Mason wrote:
>>
>> On Sun, Dec 3, 2017 at 2:17 PM, Serge Semin <fancer.lancer@gmail.com>
>> wrote:
>>>
>>> Simple (1 << pidx) operation causes undefined behaviour when
>>> pidx >= 32. It must be casted to u64 to match the actual return
>>> value of ntb_link_is_up() method, so to have all the possible
>>> peer indexes covered and to get rid of undefined behaviour.
>>> Additionally there are special macros in "linux/bitops.h" to perform
>>> the bit-set-shift operations, so it's recommended to have them used
>>> for proper bit setting.
>>
>>
>> This looks good to me, but also seems like a bug fix. Please comment
>> on if this is not noticed.
>
>
> It would be a bug on any system that has more than 32 partitions which is
> run on a 32 bit machine (or 64 partitions on a 64bit machine). Such a system
> is theoretical for the foreseeable future. But it would be good to fix it
> now.

Seems like a non-issue then. Disregard.

>
> Logan
>
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