From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>,
Rolf Eike Beer <eb@emlix.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Matt Fleming <matt@codeblueprint.co.uk>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
linux-efi <linux-efi@vger.kernel.org>,
Linux Kernel Developers List <linux-kernel@vger.kernel.org>,
stable <stable@vger.kernel.org>,
clang-built-linux <clang-built-linux@googlegroups.com>
Subject: Re: Building arm64 EFI stub with -fpie breaks build of 4.9.x (undefined reference to `__efistub__GLOBAL_OFFSET_TABLE_')
Date: Thu, 6 Jun 2019 10:58:45 +0200 [thread overview]
Message-ID: <CAKv+Gu_=aUmN76Wzy5kokgP6hcZPWAwW_7=ekqOawkfg7LPE3g@mail.gmail.com> (raw)
In-Reply-To: <20190606070807.GA17985@kroah.com>
On Thu, 6 Jun 2019 at 09:08, Greg KH <gregkh@linuxfoundation.org> wrote:
>
> On Thu, Jun 06, 2019 at 08:55:29AM +0200, Ard Biesheuvel wrote:
> > On Wed, 5 Jun 2019 at 22:48, Nick Desaulniers <ndesaulniers@google.com> wrote:
> > >
> > > On Wed, Jun 5, 2019 at 11:42 AM Ard Biesheuvel
> > > <ard.biesheuvel@linaro.org> wrote:
> > > > For the record, this is an example of why I think backporting those
> > > > clang enablement patches is a bad idea.
> > >
> > > There's always a risk involved with backports of any kind; more CI
> > > coverage can help us mitigate some of these risks in an automated
> > > fashion before we get user reports like this. I meet with the
> > > KernelCI folks weekly, so I'll double check on the coverage of the
> > > stable tree's branches. The 0day folks are also very responsive and
> > > I've spoken with them a few times, so I'll try to get to the bottom of
> > > why this wasn't reported by either of those.
> > >
> > > Also, these patches help keep Android, CrOS, and Google internal
> > > production kernels closer to their upstream sources.
> > >
> > > > We can't actually build those
> > > > kernels with clang, can we? So what is the point? </grumpy>
> > >
> > > Here's last night's build:
> > > https://travis-ci.com/ClangBuiltLinux/continuous-integration/builds/114388434
> > >
> >
> > If you are saying that plain upstream 4.9-stable defconfig can be
> > built with Clang, then I am pleasantly surprised.
>
> I know some specific configs can, there's no rule that I know of that
> 'defconfig' support is required. But then again, it might also work,
> try it and see :)
>
Well, it is the rule that the arm64 maintainers use.
> > > Also, Android and CrOS have shipped X million devices w/ 4.9 kernels
> > > built with Clang. I think this number will grow at least one order of
> > > magnitude imminently.
> > >
> >
> > I know that (since you keep reminding me :-)), but obviously, Google
> > does not care about changes that regress GCC support.
>
> What are you talking about? Bugs happen all the time, what specifically
> did "Google" do to break gcc support? If you are referring to this
> patch, and it is a regression, of course I will revert it. But note
> that gcc and 4.9 works just fine for all of the other users right now,
> remember we do do a lot of testing of these releases.
>
Don't get me wrong: I am not blaming Google for this. But having
strict Documented/ stable-rules, violating them by backporting patches
that are clearly not bug fixes, and *then* saying 'bugs happen all the
time' makes no sense to me at all.
next prev parent reply other threads:[~2019-06-06 8:59 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <779905244.a0lJJiZRjM@devpool35>
2019-06-05 16:26 ` Building arm64 EFI stub with -fpie breaks build of 4.9.x (undefined reference to `__efistub__GLOBAL_OFFSET_TABLE_') Greg KH
2019-06-05 17:27 ` Nick Desaulniers
2019-06-05 17:50 ` Nick Desaulniers
2019-06-06 7:11 ` Rolf Eike Beer
2019-08-02 7:57 ` Greg KH
2019-08-02 8:09 ` Nathan Chancellor
2019-08-02 8:16 ` Rolf Eike Beer
2019-06-05 18:42 ` Ard Biesheuvel
2019-06-05 19:26 ` Greg KH
2019-06-05 20:48 ` Nick Desaulniers
2019-06-06 6:55 ` Ard Biesheuvel
2019-06-06 7:08 ` Greg KH
2019-06-06 8:58 ` Ard Biesheuvel [this message]
2019-06-06 9:34 ` Ard Biesheuvel
2019-06-06 7:38 ` Rolf Eike Beer
2019-06-06 7:50 ` Rolf Eike Beer
2019-06-06 9:01 ` Ard Biesheuvel
2019-06-06 9:40 ` Rolf Eike Beer
2019-06-06 9:54 ` Ard Biesheuvel
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAKv+Gu_=aUmN76Wzy5kokgP6hcZPWAwW_7=ekqOawkfg7LPE3g@mail.gmail.com' \
--to=ard.biesheuvel@linaro.org \
--cc=clang-built-linux@googlegroups.com \
--cc=eb@emlix.com \
--cc=gregkh@linuxfoundation.org \
--cc=linux-efi@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=matt@codeblueprint.co.uk \
--cc=ndesaulniers@google.com \
--cc=peterz@infradead.org \
--cc=stable@vger.kernel.org \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).