> > On Tue, Aug 16, 2016 at 01:13:28PM +0100, Leif Lindholm wrote:
> > >
> > > Package: linux
> > > Version: 4.6.4-1
> > > > > > > > > X-Debbugs-CC: steve@einval.com, wookey@wookware.org, zheng.xu@linaro.org
> > >
> > > Upstream commit 211102d85 ("arm64: defconfig: enable 48-bit virtual
> > > addresses") changed the default configuration for arm64 to be 48-bit
> > > VA (CONFIG_ARM64_VA_BITS_48). This is required in order to be able to
> > > access the full amount of RAM available on some current arm64 systems
> > > (currently with large memory holes, but could apply to any system with
> > > >
> > > > 512GB of RAM). Without this, on these systems, the kernel will fail
> > > to access the initrd, which will have been located near top of RAM by
> > > GRUB. Error message given is:
> > > ---
> > > initrd not fully accessible via the linear mapping -- please check
> > > your bootloader ...
> > > ---
> > >
> > > So please enable CONFIG_ARM64_VA_BITS_48 for arm64 kernels.
> > >
> > > Note: this change _will_ cause breakage in certain userland software
> > > making non-portable assumptions about available of top address bits
> > > for pointer tagging - including luajit and mozilla-js (and hence
> > > everything using mozilla-js).
[...]
Could we possibly work around that by reducing
CONFIG_ARCH_MMAP_RND_BITS_MAX? (That's not directly configurable; it
requires patching arch/arm64/Kconfig.)
Ben.
--
Ben Hutchings
Make three consecutive correct guesses and you will be considered an
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