From: Jeff Xu <jeffxu@chromium.org>
To: Dave Hansen <dave.hansen@intel.com>
Cc: linux-mm@kvack.org, "Stephen Röttger" <sroettger@chromium.org>,
"tglx@linutronix.de" <tglx@linutronix.de>,
"Jorge Lucangeli Obes" <jorgelo@chromium.org>,
"Kees Cook" <keescook@chromium.org>
Subject: Re: x86/pkeys in early kernel version
Date: Wed, 25 Jan 2023 17:43:07 -0800 [thread overview]
Message-ID: <CABi2SkX9Oud5uiu6wZTPRV19WF_rOHchSAjQDyNi-CeiALeCiA@mail.gmail.com> (raw)
In-Reply-To: <e1c2738c-3f34-b0fc-94b1-c9c578191598@intel.com>
On Wed, Jan 25, 2023 at 11:13 AM Dave Hansen <dave.hansen@intel.com> wrote:
>
> On 1/25/23 11:02, Jeff Xu wrote:
> > I'm investigating if there is a need to backport x86/pkeys
> > fix/feature into earlier kernel versions, Chrome is starting to use
> > PKEY in x86, and I hope experts here can give advice on this.
> >
> > For background, ChromeOS regularly syncs with upstream kernel
> > versions, and has production that uses 4.4/4.14/4.19/5.4/5.10/5.15.
> To be honest, I haven't got the foggiest idea what you need to backport.
> I can barely keep track of mainline.
>
> Are there really production 4.4 kernels that you need to run on
> pkey-capable hardware? That would mean running a 2015-era kernel on a
> CPU released in late 2020. I think Q3'2020 is when the 11th gen CPUs
> came out which were the first non-server CPUs that had pkeys.
>
Thanks!
For 11th gen CPUs, chromebook uses 5.4 and above, so that eliminate
half of the versions.
> On a positive note, the pkeys selftest has been pretty consistently
> updated as we find bugs. I'd be curious how well a mainline version of
> that selftests runs on old kernels. But, I'm too scared to find out
> what's down that particular rabbit hole myself.
I can start with 5.10 or 5.15, it seems there are quite some changes though,
for example, this one by Thomas
https://lore.kernel.org/lkml/20210623120127.327154589@linutronix.de/
My question is, if I have to pick a version that doesn't require a lot
of backporting,
and functionality is stable enough, what version would this be ? 5.4/5.10/5.15 ?
-Jeff
next prev parent reply other threads:[~2023-01-26 1:43 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-25 19:02 Jeff Xu
2023-01-25 19:12 ` Dave Hansen
2023-01-26 1:43 ` Jeff Xu [this message]
2023-01-27 5:36 ` Jeff Xu
2023-01-27 5:55 ` Kyle Huey
2023-01-27 19:08 ` Jeff Xu
2023-01-27 19:22 ` Kyle Huey
2023-01-27 19:30 ` Kyle Huey
2023-01-27 21:12 ` Jeff Xu
2023-03-13 23:24 ` Jeff Xu
2023-03-14 0:24 ` Dave Hansen
2023-01-27 15:22 ` Dave Hansen
2023-01-27 17:58 ` Jeff Xu
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