Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1689086 > unrolled thread

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

Started by"gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>
First post2017-07-17 16:20 +0200
Last post2017-07-17 19:10 +0200
Articles 2 — 2 participants

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.


Contents

  Re: [PATCH v3] drivers/char: kmem: disable on arm64 "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org> - 2017-07-17 16:20 +0200
    Re: [PATCH v3] drivers/char: kmem: disable on arm64 Ard Biesheuvel <ard.biesheuvel@linaro.org> - 2017-07-17 19:10 +0200

#1689086 — Re: [PATCH v3] drivers/char: kmem: disable on arm64

From"gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>
Date2017-07-17 16:20 +0200
SubjectRe: [PATCH v3] drivers/char: kmem: disable on arm64
Message-ID<u4f2p-69R-3@gated-at.bofh.it>
On Tue, Jun 20, 2017 at 01:20:49PM +0200, Ard Biesheuvel wrote:
> On 20 June 2017 at 08:59, Ard Biesheuvel <ard.biesheuvel@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?  :)

[toc] | [next] | [standalone]


#1689277

FromArd Biesheuvel <ard.biesheuvel@linaro.org>
Date2017-07-17 19:10 +0200
Message-ID<u4hGX-7SW-37@gated-at.bofh.it>
In reply to#1689086
On 17 July 2017 at 15:18, gregkh@linuxfoundation.org
<gregkh@linuxfoundation.org> wrote:
> On Tue, Jun 20, 2017 at 01:20:49PM +0200, Ard Biesheuvel wrote:
>> On 20 June 2017 at 08:59, Ard Biesheuvel <ard.biesheuvel@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?  :)
>

This is already in mainline as 06c35ef1fdf8d955684448683f7e48ac5f15ccfd

[toc] | [prev] | [standalone]


Back to top | Article view | linux.kernel


csiph-web