Re: [Xenomai] Xenomai 3: comapt issues with RTDM

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2015-07-23 11:22, Philippe Gerum wrote:
> On 07/23/2015 11:08 AM, Jan Kiszka wrote:
>> On 2015-07-23 10:40, Philippe Gerum wrote:
>>> On 07/21/2015 04:54 PM, Jan Kiszka wrote:
>>>> On 2015-07-21 14:51, Philippe Gerum wrote:
>>>>> On 07/21/2015 02:27 PM, Jan Kiszka wrote:
>>>>>> Hi Philippe,
>>>>>>
>>>>>> just a heads up, I'll try to address this later:
>>>>>>
>>>>>> I received a report that include/rtdm/uapi/rtdm.h contains some data
>>>>>> structures that are used between the kernel and the userspace library
>>>>>> (so not directly by applications) and are not compatible with
>>>>>> 32-on-64-bit (compat) scenarios. We should probably promote anything
>>>>>> that is longer on 64-bit to that size, unconditionally. As this affects
>>>>>> the ABI, it should be fixed before 3.0 release, ideally.
>>>>>>
>>>>>
>>>>> That would require to fix up the client drivers (setsockopt, getsockopt
>>>>> typically). Ok, I'll have a look when I'm done with testing the blackfin
>>>>> port.
>>>>
>>>> Indeed. Just realized that there are already compat structs for the
>>>> socket stuff. However, and that was what our user stumbled over, there
>>>> is none for _rtdm_mmap_request. But that should be really internal, right?
>>>>
>>>
>>> mmap() has the compat thunk for 32<->64 bit conversion already, so this
>>> is ok.
>>
>> Ok... Rechecking the bug report here, the issue is rather the case that
>> off_t becomes 64 bit when defining -D_FILE_OFFSET_BITS=64 for your
>> userland. We are apparently required to account for that case as well.
>>
> 
> Ok, so let's move the offset member to loff_t and compat_loff_t in the
> mmap request descriptors, that should do the trick.
> 

I only forwarded this suggestion internally, unfortunately cannot tell
yet how it was implemented, just received the early feedback that it is
not yet working. Maybe we are overseeing something, maybe something went
wrong with the implementation. Will be checked tomorrow.

Jan

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