[LLVMdev] Sporadic "RealOffset <= INT32_MAX && RealOffset >= INT32_MIN" failures with MCJIT on Windows

[Keno Fischer]

This might be related to GOT relocations. I rewrote that part of
RuntimeDyldELFbecause I was seeing this issue. Have you tried trunk?

On Fri, May 22, 2015 at 5:10 PM, Ramkumar Ramachandra <artagnon at gmail.com>
wrote:

> So it appears that we get about half the crashes with the large code
> model. The rest are crashing in the same way. It could either mean that
> large code model still takes that crashing codepath and that the number of
> crashes only went down by chance, or that in one place in the flow, large
> code model is not matched to mean ELF::R_X86_64_PC64. I'm digging into this
> issue further, but any hints along the way would be appreciated.
>
> Thanks.
>
> Ram
>
> On Tue, May 19, 2015 at 12:06 PM, Reid Kleckner <rnk at google.com> wrote:
>
>> That sounds like a PC-relative relocation failure. Usually this happens
>> when the relocation target is more than 2 GB away from the source. Try
>> using the large code model or tweaking the memory manager.
>>
>> It turns out it's surprisingly hard to portably allocate some memory and
>> then allocate some more within a 2 GB offset of the first allocation in a
>> 64-bit process. For various reasons that I don't understand, reserving 2 GB
>> of address space upfront and allocating from that is not workable for some
>> MCJIT clients.
>>
>> On Tue, May 19, 2015 at 7:19 AM, Ramkumar Ramachandra <artagnon at gmail.com
>> > wrote:
>>
>>> Hi,
>>>
>>> We are seeing sporadic crashes since we migrated to MCJIT on Win64. The
>>> same tests pass without issues on Mac64 and Linux64. The issue is this
>>> assertion failure in RuntimeDyldELF.c:
>>>
>>>   RealOffset <= INT32_MAX && RealOffset >= INT32_MIN
>>>
>>> I haven't managed to successfully catch the failure in Visual to try and
>>> debug it. Any tips on how to make progress?
>>>
>>> Oh, and we're on LLVM 3.5.
>>>
>>> Thanks.
>>>
>>> Ram
>>>
>>> _______________________________________________
>>> LLVM Developers mailing list
>>> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>>>
>>>
>>
>
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20150522/476a9e14/attachment.html>