On 12/06, Ard Biesheuvel wrote:
>
> On Fri, 6 Dec 2024 at 13:32, Oleg Nesterov <oleg@redhat.com> wrote:
> >
> > +#ifdef CONFIG_STACKPROTECTOR
> >  /* needed for Clang - see arch/x86/entry/entry.S */
> >  PROVIDE(__ref_stack_chk_guard = __stack_chk_guard);
> > +#endif
> >
> >  #ifdef CONFIG_X86_64
> >  /*
>
> This shouldn't be necessary - PROVIDE() is only evaluated if a
> reference exists to the symbol it defines.
>
> Also, I'm failing to reproduce this. Could you share your .config,
> please, and the error that you get during the build?

Please see the attached .config

without the change above:

	$ make bzImage
	  CALL    scripts/checksyscalls.sh
	  DESCEND objtool
	  INSTALL libsubcmd_headers
	  UPD     include/generated/utsversion.h
	  CC      init/version-timestamp.o
	  KSYMS   .tmp_vmlinux0.kallsyms.S
	  AS      .tmp_vmlinux0.kallsyms.o
	  LD      .tmp_vmlinux1
	./arch/x86/kernel/vmlinux.lds:154: undefined symbol `__stack_chk_guard' referenced in expression
	scripts/Makefile.vmlinux:77: recipe for target 'vmlinux' failed
	make[2]: *** [vmlinux] Error 1
	/home/oleg/tmp/LINUX/Makefile:1225: recipe for target 'vmlinux' failed
	make[1]: *** [vmlinux] Error 2
	Makefile:251: recipe for target '__sub-make' failed
	make: *** [__sub-make] Error 2

perhaps this is because my toolchain is quite old,

	$ ld -v
	GNU ld version 2.25-17.fc23

but according to Documentation/process/changes.rst

	binutils               2.25             ld -v

it is still supported.

Oleg.