[PATCH v3] drivers/char: kmem: disable on arm64

gregkh at linuxfoundation.org gregkh at linuxfoundation.org
Mon Jul 17 07:18:40 PDT 2017


On Tue, Jun 20, 2017 at 01:20:49PM +0200, Ard Biesheuvel wrote:
> On 20 June 2017 at 08:59, Ard Biesheuvel <ard.biesheuvel at linaro.org> wrote:
> > As it turns out, arm64 deviates from other architectures in the way it
> > maps the VMALLOC region: on most (all?) other architectures, it resides
> > strictly above the kernel's direct mapping of DRAM, but on arm64, this
> > is the other way around. For instance, for a 48-bit VA configuration,
> > we have
> >
> >   modules : 0xffff000000000000 - 0xffff000008000000   (   128 MB)
> >   vmalloc : 0xffff000008000000 - 0xffff7dffbfff0000   (129022 GB)
> >   ...
> >   vmemmap : 0xffff7e0000000000 - 0xffff800000000000   (  2048 GB maximum)
> >             0xffff7e0000000000 - 0xffff7e0003ff0000   (    63 MB actual)
> >   memory  : 0xffff800000000000 - 0xffff8000ffc00000   (  4092 MB)
> >
> > This has mostly gone unnoticed until now, but it does appear that it
> > breaks an assumption in the kcore
> 
> s/kcore/kmem/

v4?  :)




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