Re: [PATCH] Add build time guard to detect off_t mismatch

On 12.05.26 15:01, Richard Weinberger wrote:
> On Thu, May 7, 2026 at 4:22 PM Jan Kiszka <[email protected]> wrote:
>> OK, given that Xenomai intercepts the mmap path, we could argue that
>> this is also stable relevant.
>>
>> Can you confirm that this issue is truly gone in next, whatever mode you
>> choose on both sides?
> 
> Still had no chance to build or run tests with Xenomai next on my ARM boards.
> But I had a look at the code.
> 
> I think it's still broken, at least for the following scenario:
> - 32 bit application built with  _FILE_OFFSET_BITS=64
> - 32 bit libcobalt without
> - application calls mmap() using __RT(mmap), so __cobalt_mmap() in libcobalt
> - off_t differs in size ass seen by caller and callee

A 32-bit app built with _FILE_OFFSET_BITS=64 is supposed to call mmap64
(as symbol). In you scenario above, it should run into an unresolvable
symbol error.

Jan

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