Re: Cannot compile 6.1.2 kernel release

[Willy Tarreau <w@1wt.eu>]

On Sun, Jan 01, 2023 at 09:01:22AM +0000, Lukasz Kalamlacki wrote:
> 
> On 1.01.2023 09:47, Greg KH wrote:
> > On Sun, Jan 01, 2023 at 08:14:12AM +0000, Lukasz Kalamlacki wrote:
> >> On 1.01.2023 07:53, Willy Tarreau wrote:
> >>> On Sat, Dec 31, 2022 at 04:58:51PM +0000, Lukasz Kalamlacki wrote:
> >>>> Hey,
> >>>>
> >>>>
> >>>> Do you have an issue compiling 6.1.2 linux kernel?
> >>>>
> >>>> I cannot compile it.
> >>> For me it compiles and boots. You'll need to share your config and error
> >>> report if you want to get some help.
> >>>
> >>> Willy
> >> I was trying to compile on Debian Bullseye where default gcc is version
> >> 10, when I upgraded gcc to version 12 from sid repo i Was able to
> >> compile too. On stable Debian without addition during compile
> >> "segmentation fault" occurs at the compilation of cx8-i2c.c file. You
> >> can try on kvm or virtualbox this compilation.
> > Sounds like a gcc bug you should be notifying the gcc developers about.
> >
> > good luck!
> >
> > greg k-h
> 
> To be precise I have this on gcc 10 in Debian:
> 
> 
> during GIMPLE pass: fre
> drivers/media/pci/cx18/cx18-i2c.c: In function 'init_cx18_i2c':
> drivers/media/pci/cx18/cx18-i2c.c:300:1: internal compiler error:
> Segmentation fault
>    300 | }

As Greg said it's definitely a compiler bug, so it will interest Gcc
developers, or your distro's gcc package maintainers in case it's not
up to date. There are toolchains available on kernel.org here:

   https://mirrors.edge.kernel.org/pub/tools/crosstool/

The laest 10.x available is 10.4. If it works with this one it may indicate
that your package is lacking some recent fixes, so it might be a question
for your distro's gcc package maintainers. If it fails it indicates a bug
not yet fixed in gcc and your distro maintainers won't be of any help here,
you'll have to report it to the gcc devs instead.

Note that they'll very likely ask about a reproducer (and most likely your
config). But a quick test for me with this driver built as a module on
x86_64 with gcc-10.4 from kernel.org doesn't show any problem:

  $ make CROSS_COMPILE=/f/tc/nolibc/gcc-10.4.0-nolibc/x86_64-linux/bin/x86_64-linux- drivers/media/pci/cx18/cx18-i2c.o
  (...)
    CC [M]  drivers/media/pci/cx18/cx18-i2c.o
  $ ll drivers/media/pci/cx18/cx18-i2c.o 
  -rw-rw-r-- 1 willy users 33920 Jan  1 11:00 drivers/media/pci/cx18/cx18-i2c.o

Hoping this helps,
Willy