[PATCH] D25467: [ELF] - Alternative fix to prevent possible crash on large output.

[Ed Maste via llvm-commits]

On 25 October 2016 at 09:50, Ed Maste <emaste at freebsd.org> wrote:
> On 17 October 2016 at 17:26, Rui Ueyama via llvm-commits
> <llvm-commits at lists.llvm.org> wrote:
>>
>>  - FreeBSD: what is the status of building the entire FreeBSD system with
>> LLD? Can it build everything including the kernel?
>
> Outstanding FreeBSD/lld issues are tracked in http://llvm.org/pr23214 .
>
> I have booted a lld-linked FreeBSD x86-64 kernel in the past, maybe
> two months or so ago, but it has since regressed. It still builds but
> the kernel crashes early on, and I haven't yet bisected to find out
> when this started happening. I've been testing ToT FreeBSD built with
> ToT LLD, so it's possible it's a FreeBSD change that's responsible.

It turns out this is due to r282560
(https://reviews.llvm.org/rL282560) which changed MAXPAGESIZE to
0x1000 from 0x200000.

This ends up with the kernel's reported phys address at 0x1000, and
then none of the "low" memory under 640K is available.