Re: ld.lld: error: Function Import: link error: linking module flags 'Code Model': IDs have conflicting values: 'i32 3' from vmlinux.a(init.o at 899876), and 'i32 1' from vmlinux.a(security.o at 937376)

[Palmer Dabbelt]

On Sun, 29 Jun 2025 23:45:06 PDT (-0700), namcao@xxxxxxxxxxxxx wrote:
> +Cc: linux-riscv@xxxxxxxxxxxxxxxxxxx
>
> On Sun, Jun 29, 2025 at 02:25:33AM +0800, kernel test robot wrote:
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > head:   aaf724ed69264719550ec4f194d3ab17b886af9a
> > commit: 890ba5be6335dbbbc99af14ea007befb5f83f174 Revert "riscv: Define TASK_SIZE_MAX for __access_ok()"
> > date:   5 days ago
> > config: riscv-randconfig-001-20250628 (https://download.01.org/0day-ci/archive/20250629/202506290255.KBVM83vZ-lkp@xxxxxxxxx/config)
> > compiler: clang version 21.0.0git (https://github.com/llvm/llvm-project e04c938cc08a90ae60440ce22d072ebc69d67ee8)
> > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250629/202506290255.KBVM83vZ-lkp@xxxxxxxxx/reproduce)
> >
> > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > the same patch/commit), kindly add following tags
> > | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > | Closes: https://lore.kernel.org/oe-kbuild-all/202506290255.KBVM83vZ-lkp@xxxxxxxxx/
> >
> > All errors (new ones prefixed by >>):
> >
> >    ld.lld: error: Function Import: link error: linking module flags 'Code Model': IDs have conflicting values: 'i32 3' from vmlinux.a(init.o at 899876), and 'i32 1' from vmlinux.a(net-traces.o at 1014596)
> >    ld.lld: error: Function Import: link error: linking module flags 'Code Model': IDs have conflicting values: 'i32 3' from vmlinux.a(init.o at 899876), and 'i32 1' from vmlinux.a(e1000_main.o at 992876)
> >    ld.lld: error: Function Import: link error: linking module flags 'Code Model': IDs have conflicting values: 'i32 3' from vmlinux.a(init.o at 899876), and 'i32 1' from vmlinux.a(core.o at 912236)
> > >> ld.lld: error: Function Import: link error: linking module flags 'Code Model': IDs have conflicting values: 'i32 3' from vmlinux.a(init.o at 899876), and 'i32 1' from vmlinux.a(security.o at 937376)
> > >> ld.lld: error: Function Import: link error: linking module flags 'Code Model': IDs have conflicting values: 'i32 3' from vmlinux.a(init.o at 899876), and 'i32 1' from vmlinux.a(sock.o at 1012256)
> >    ld.lld: error: Function Import: link error: linking module flags 'Code Model': IDs have conflicting values: 'i32 3' from vmlinux.a(init.o at 899876), and 'i32 1' from vmlinux.a(ioctl.o at 1015736)
> > >> ld.lld: error: Function Import: link error: linking module flags 'Code Model': IDs have conflicting values: 'i32 3' from vmlinux.a(init.o at 899876), and 'i32 1' from vmlinux.a(socket.o at 1012196)
> >    ld.lld: error: Function Import: link error: linking module flags 'Code Model': IDs have conflicting values: 'i32 3' from vmlinux.a(init.o at 899876), and 'i32 1' from vmlinux.a(ring_buffer.o at 910076)
> >    ld.lld: error: Function Import: link error: linking module flags 'Code Model': IDs have conflicting values: 'i32 3' from vmlinux.a(init.o at 899876), and 'i32 1' from vmlinux.a(hugetlb.o at 919016)
> > >> ld.lld: error: Function Import: link error: linking module flags 'Code Model': IDs have conflicting values: 'i32 3' from vmlinux.a(init.o at 899876), and 'i32 1' from vmlinux.a(btf.o at 913916)
> >    ld.lld: error: Function Import: link error: linking module flags 'Code Model': IDs have conflicting values: 'i32 3' from vmlinux.a(init.o at 899876), and 'i32 1' from vmlinux.a(page_alloc.o at 918536)
> >    ld.lld: error: Function Import: link error: linking module flags 'Code Model': IDs have conflicting values: 'i32 3' from vmlinux.a(init.o at 899876), and 'i32 1' from vmlinux.a(slub.o at 918836)
> >    ld.lld: error: Function Import: link error: linking module flags 'Code Model': IDs have conflicting values: 'i32 3' from vmlinux.a(init.o at 899876), and 'i32 1' from vmlinux.a(spi.o at 992036)
> >    ld.lld: error: Function Import: link error: linking module flags 'Code Model': IDs have conflicting values: 'i32 3' from vmlinux.a(init.o at 899876), and 'i32 1' from vmlinux.a(vmalloc.o at 918296)
> >    ld.lld: error: Function Import: link error: linking module flags 'Code Model': IDs have conflicting values: 'i32 3' from vmlinux.a(init.o at 899876), and 'i32 1' from vmlinux.a(syscall.o at 912296)
> >    ld.lld: error: Function Import: link error: linking module flags 'Code Model': IDs have conflicting values: 'i32 3' from vmlinux.a(init.o at 899876), and 'i32 1' from vmlinux.a(trace.o at 910136)
> >    ld.lld: error: Function Import: link error: linking module flags 'Code Model': IDs have conflicting values: 'i32 3' from vmlinux.a(init.o at 899876), and 'i32 1' from vmlinux.a(skbuff.o at 1012376)
> >    ld.lld: error: Function Import: link error: linking module flags 'Code Model': IDs have conflicting values: 'i32 3' from vmlinux.a(init.o at 899876), and 'i32 1' from vmlinux.a(vmscan.o at 916376)
> >    ld.lld: error: Function Import: link error: linking module flags 'Code Model': IDs have conflicting values: 'i32 3' from vmlinux.a(init.o at 899876), and 'i32 1' from vmlinux.a(xprtsock.o at 1024196)
> >    ld.lld: error: Function Import: link error: linking module flags 'Code Model': IDs have conflicting values: 'i32 3' from vmlinux.a(init.o at 899876), and 'i32 1' from vmlinux.a(filemap.o at 915776)
> >    ld.lld: error: too many errors emitted, stopping now (use --error-limit=0 to see all errors)
>
> I'm not sure what lld is saying here. It seems this problem has always been
> there, the revert commit just made it appears more.
>
> These errors should still be investigated, but I think the revert commit is
> fine.

Ya, I agree.

> I see CONFIG_CMODEL_MEDLOW=y, so probably has something to do with
> arch/riscv/mm/init.c is compiled with -mcmodel=medany, while the others are
> compiled with -mcmodel=medlow. I leave it to smarter minds..

LLVM has a blurb that says

   // Linking object files with different code models is undefined behavior
   // because the compiler would have to generate additional code (to span
   // longer jumps) if a larger code model is used with a smaller one.
   // Therefore we will treat attempts to mix code models as an error.

which is just wacky, so I'm moaning about it over here 
<https://github.com/ClangBuiltLinux/linux/issues/2097>...