v4.14.9 on ARMv5: OK with gcc 4.8/5.4, NOK with gcc 7.2

[linux@armlinux.org.uk (Russell King - ARM Linux)]

On Thu, Jan 04, 2018 at 06:02:38PM +0100, Thomas Petazzoni wrote:
> Hello,
> 
> I'm pretty sure it has already been reported, but just in case: I'm
> testing v4.14.9 on an ARMv5 platform (Kirkwood-based OpenBlocks A7).
> mvebu_v5_defconfig boots fine when built with gcc 4.8 (good old
> Sourcery toolchain) or gcc 5.4 (some old Linaro toolchain), but doesn't
> boot at all when built with gcc 7.2 (Fedora toolchain). Even when
> configured and booted with earlyprintk, the kernel doesn't say anything.
> 
> The toolchain being used is the default ARM toolchain provided by
> Fedora 27. It says:
> 
> gcc version 7.2.1 20170915 (Red Hat Cross 7.2.1-1) (GCC)
> GNU ld version 2.29.1-1.fc27
> 
> So it's quite bleeding edge.
> 
> Let me know if this has already been fixed, or if I should test a
> patch. I have not tested 4.15-rc or next at this point, assuming that
> if a fix had been made, it would have been backported to 4.14-stable.

It's a known issue -

http://archive.armlinux.org.uk/lurker/message/20171018.095713.a56a717b.en.html

but so far no patches have been forthcoming for the kernel, because
(I guess) it's deemed to be a gcc bug.

It's one of those discussions that just seemed to die without any
real conclusion.

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
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