Re: crosstool: x86 kernel compiled with GCC 14.1 fails to boot

[Arnd Bergmann]

On Tue, Jul 9, 2024, at 17:29, Jeff Johnson wrote:
> On 7/8/2024 10:44 PM, Arnd Bergmann wrote:
>> On Tue, Jul 9, 2024, at 05:55, Jeff Johnson wrote:
>
> I picked my favorite to begin with, enabling KASAN (which in turn enabled a
> few others). The resulting kernel did not boot for me (just saw a black screen
> after the GRUB menu). Diff between working and non-working config is below.

Ok, good to know. I've added the KASAN developers to Cc now, maybe
they have already seen reports of x86 kernels failing with gcc-14?

> I then downloaded and built the config you supplied. With that I have the same
> behavior as my original config, the display is frozen with:
> Loading initial ramdisk ...

Interesting, so the same config that works for me fails on your
machine. I can see three possible reasons for this:

- qemu vs hardware -- Can you try running this kernel in
qemu-system-x86_64 to see if that still boots

- kernel version -- it's possible that this is a known bug
that was already fixed in the 6.10-rc7 kernel source I
tried, or that your source tree has a new bug that I don't.
Which version did you try?

- cross-compile vs native compile -- It's possible that my
cross-built native x86_64 compiler has a bug that is not
in natively built gcc binaries, or in the cross compiler
I have on ARM. I've mostly ruled this one out by building
the same kernel using the x86 compilers through qemu-user.

Arnd