Re: build failure with crosstools gcc 15.1.0

[Mark Rutland <mark.rutland@arm.com>]

On Fri, Jul 04, 2025 at 03:25:49PM +0200, Arnd Bergmann wrote:
> On Mon, Jun 23, 2025, at 21:52, Jeff Johnson wrote:
> > I've been using crosstools gcc 14.2.0.
> >
> > Today I saw that gcc 15.1.0 has been added to crosstools:
> > https://www.kernel.org/pub/tools/crosstool/files/bin/x86_64/15.1.0/
> >
> > But when I try it I'm getting an error:
> >   LD      vmlinux.o
> > vmlinux.o: warning: objtool: ncsi_process_next_channel() falls through 
> > to next function ncsi_channel_monitor.cold()
> > vmlinux.o: error: objtool [elf.c:1360]: elf_write: elf_update failed: 
> > invalid section alignment
> > make[5]: *** [scripts/Makefile.vmlinux_o:72: vmlinux.o] Error 1
> > make[5]: *** Deleting file 'vmlinux.o'
> > make[5]: Target '__default' not remade because of errors.
> > make[4]: *** [Makefile:1217: vmlinux_o] Error 2
> > make[4]: Target 'all' not remade because of errors.
> > make[3]: *** [debian/rules:80: build-arch] Error 2
> > make[3]: Target 'binary' not remade because of errors.
> > dpkg-buildpackage: error: make -f debian/rules binary subprocess 
> > returned exit status 2
> > make[2]: *** [scripts/Makefile.package:126: bindeb-pkg] Error 2
> > make[1]: *** 
> > [/local/mnt/workspace/jjohnson/kernel/laptop-debug/Makefile:1635: 
> > bindeb-pkg] Error 2
> > make: *** [Makefile:248: __sub-make] Error 2
> > make: Target 'bindeb-pkg' not remade because of errors.
> >
> > This is with a simple x86 make C=1 W=1 -j8 bindeb-pkg
> >
> > Any thoughts?
> 
> Hi Jeff,
> 
> Sorry for the late reply, have you figured it out in the meantime?
> 
> I couldn't immediately reproduce it, so it may already be fixed
> in linux-next.

FWIW, I consistently see the same objtool splat for v6.16-rc7 and
next-20250724, built with GCC 15.1.0 from the kernel.org cross
toolchains page, e.g.

$ git clean -fdx
$ usekorg 15.1.0 make ARCH=x86_64 CROSS_COMPILE=x86_64-linux- defconfig
$ usekorg 15.1.0 make ARCH=x86_64 CROSS_COMPILE=x86_64-linux- -j56

The build machine is Debian 11.10 on x86-64., and 'usekorg ${VERSION}'
is my script to put the relevant kernel.org cross toolchain binaries
into my $PATH.

Doing the same with the 14.2.0 binaries, e.g.

$ git clean -fdx
$ usekorg 14.2.0 make ARCH=x86_64 CROSS_COMPILE=x86_64-linux- defconfig
$ usekorg 14.2.0 make ARCH=x86_64 CROSS_COMPILE=x86_64-linux- -j56

... builds successfully, but there are some objtool warnings:

|   LD      vmlinux.o
| vmlinux.o: warning: objtool: x86_init_dev_msi_info+0x58: relocation to !ENDBR: irq_chip_retrigger_hierarchy+0x0
| vmlinux.o: warning: objtool: .export_symbol+0x3e78: data relocation to !ENDBR: irq_chip_retrigger_hierarchy+0x0
| vmlinux.o: warning: objtool: .export_symbol+0x31140: data relocation to !ENDBR: stpcpy+0x0
| vmlinux.o: warning: objtool: dmar_msi_controller+0x58: data relocation to !ENDBR: irq_chip_retrigger_hierarchy+0x0
| vmlinux.o: warning: objtool: intcapxt_controller+0x58: data relocation to !ENDBR: irq_chip_retrigger_hierarchy+0x0
| vmlinux.o: warning: objtool: hpet_msi_controller+0x58: data relocation to !ENDBR: irq_chip_retrigger_hierarchy+0x0
| vmlinux.o: warning: objtool: ioapic_ir_chip+0x58: data relocation to !ENDBR: irq_chip_retrigger_hierarchy+0x0
| vmlinux.o: warning: objtool: ioapic_chip+0x58: data relocation to !ENDBR: irq_chip_retrigger_hierarchy+0x0

Mark.