next-20250407: qemu_x86_64 clang-20, clang-nightly no console log but gcc-13 boot pass

next-20250407: qemu_x86_64 clang-20, clang-nightly no console log but gcc-13 boot pass

[Naresh Kamboju]

Regressions on qemu-x86_64 with clang-20 and clang-nightly on the
Linux next-20250407 and no console output.

The gcc-13 builds boot pass on qemu-x86_64.

First seen on the next-20250407.
Bad: next-20250407
Good:next-20250404

* qemu-x86_64, boot
 - boot/clang-20-lkftconfig
 - boot/clang-20-lkftconfig-compat
 - boot/clang-nightly-lkftconfig

Regression Analysis:
- New regression? Yes
- Reproducibility? Yes

Boot regression: qemu_x86_64 clang-20, clang-nightly no console log
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>

## Boot log
<no console output>

Clang-20 versions:
  "name": "clang",
  "version": "20.1.2",
  "version_full": "Debian clang version 20.1.2
(++20250330123306+5ba194972878-1~exp1~20250330003423.94)"

Clang-nightly versions:
  "name": "clang",
  "version": "21.0.0",
  "version_full": "Debian clang version 21.0.0
(++20250402105505+c57b9c233a87-1~exp1~20250402225526.1363)"

qemu-system-x86:
   installed at version: 9.2.2+ds-1+b2

## Source
* Kernel version: 6.15.0-rc1-next-20250407
* Git tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
* Git sha: 2bdde620f7f2bff2ff1cb7dc166859eaa0c78a7c
* Git describe: 6.15.0-rc1-next-20250407
* Project details:
https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20250407/

## Test
* Test log: https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20250407/testrun/27930289/suite/boot/test/clang-20-lkftconfig/log
* Test details:
https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20250407/testrun/27930289/suite/boot/test/clang-20-lkftconfig/details/
* Test history:
https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20250407/testrun/27930289/suite/boot/test/clang-20-lkftconfig/history/
* Test history:
https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20250407/testrun/27930138/suite/boot/test/clang-nightly-lkftconfig/history/
* Build link: https://storage.tuxsuite.com/public/linaro/lkft/builds/2vNpFdnHoEolEu77VmTYD8bmuBd/
* Kernel config:
https://storage.tuxsuite.com/public/linaro/lkft/builds/2vNpFdnHoEolEu77VmTYD8bmuBd/config

--
Linaro LKFT
https://lkft.linaro.org

Re: next-20250407: qemu_x86_64 clang-20, clang-nightly no console log but gcc-13 boot pass

[Naresh Kamboju]

On Mon, 7 Apr 2025 at 17:15, Naresh Kamboju <naresh.kamboju@linaro.org> wrote:
>
> Regressions on qemu-x86_64 with clang-20 and clang-nightly on the
> Linux next-20250407 and no console output.
>
> The gcc-13 builds boot pass on qemu-x86_64.
>
> First seen on the next-20250407.
> Bad: next-20250407
> Good:next-20250404
>
> * qemu-x86_64, boot
>  - boot/clang-20-lkftconfig
>  - boot/clang-20-lkftconfig-compat
>  - boot/clang-nightly-lkftconfig
>
> Regression Analysis:
> - New regression? Yes
> - Reproducibility? Yes
>
> Boot regression: qemu_x86_64 clang-20, clang-nightly no console log
> Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>

Anders bisected this and found,
# first bad commit:
   [cc34e658c6db493c1524077e95b42d478de58f2b]
   x86/boot: Move the early GDT/IDT setup code into startup/

Lore report link,
 - https://lore.kernel.org/all/CA+G9fYt4VVa3kUDR+ze05xM+fRmMBVfbBTsypUq5oOpAfuzjfg@mail.gmail.com/

- Naresh

Re: next-20250407: qemu_x86_64 clang-20, clang-nightly no console log but gcc-13 boot pass

[Ard Biesheuvel]

On Mon, 7 Apr 2025 at 18:17, Naresh Kamboju <naresh.kamboju@linaro.org> wrote:
>
> On Mon, 7 Apr 2025 at 17:15, Naresh Kamboju <naresh.kamboju@linaro.org> wrote:
> >
> > Regressions on qemu-x86_64 with clang-20 and clang-nightly on the
> > Linux next-20250407 and no console output.
> >
> > The gcc-13 builds boot pass on qemu-x86_64.
> >
> > First seen on the next-20250407.
> > Bad: next-20250407
> > Good:next-20250404
> >
> > * qemu-x86_64, boot
> >  - boot/clang-20-lkftconfig
> >  - boot/clang-20-lkftconfig-compat
> >  - boot/clang-nightly-lkftconfig
> >
> > Regression Analysis:
> > - New regression? Yes
> > - Reproducibility? Yes
> >
> > Boot regression: qemu_x86_64 clang-20, clang-nightly no console log
> > Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
>
> Anders bisected this and found,
> # first bad commit:
>    [cc34e658c6db493c1524077e95b42d478de58f2b]
>    x86/boot: Move the early GDT/IDT setup code into startup/
>
> Lore report link,
>  - https://lore.kernel.org/all/CA+G9fYt4VVa3kUDR+ze05xM+fRmMBVfbBTsypUq5oOpAfuzjfg@mail.gmail.com/
>

Thanks for the report. I'll look into this.

Re: next-20250407: qemu_x86_64 clang-20, clang-nightly no console log but gcc-13 boot pass

[Ingo Molnar]

* Ard Biesheuvel <ardb@kernel.org> wrote:

> On Mon, 7 Apr 2025 at 18:17, Naresh Kamboju <naresh.kamboju@linaro.org> wrote:
> >
> > On Mon, 7 Apr 2025 at 17:15, Naresh Kamboju <naresh.kamboju@linaro.org> wrote:
> > >
> > > Regressions on qemu-x86_64 with clang-20 and clang-nightly on the
> > > Linux next-20250407 and no console output.
> > >
> > > The gcc-13 builds boot pass on qemu-x86_64.
> > >
> > > First seen on the next-20250407.
> > > Bad: next-20250407
> > > Good:next-20250404
> > >
> > > * qemu-x86_64, boot
> > >  - boot/clang-20-lkftconfig
> > >  - boot/clang-20-lkftconfig-compat
> > >  - boot/clang-nightly-lkftconfig
> > >
> > > Regression Analysis:
> > > - New regression? Yes
> > > - Reproducibility? Yes
> > >
> > > Boot regression: qemu_x86_64 clang-20, clang-nightly no console log
> > > Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
> >
> > Anders bisected this and found,
> > # first bad commit:
> >    [cc34e658c6db493c1524077e95b42d478de58f2b]
> >    x86/boot: Move the early GDT/IDT setup code into startup/
> >
> > Lore report link,
> >  - https://lore.kernel.org/all/CA+G9fYt4VVa3kUDR+ze05xM+fRmMBVfbBTsypUq5oOpAfuzjfg@mail.gmail.com/
> >
> 
> Thanks for the report. I'll look into this.

I've zapped cc34e658c6db from tip:x86/boot for the time being.

I have the same request as for the other patches applies, please split 
it up into ~3 patches for better bisectability and ease of review:

 - first the mechanic movement of code, with very few changes (if the 
   result builds & boots),

 - then drop the RIP_REL_REF() uses in the second patch,

 - and drop __head annotations in the third patch.

Thanks,

	Ingo