Re: [PATCH v7 8/8] kbuild: rebuild multi-object modules when objtool is updated

From: Masahiro Yamada
Date: Fri May 27 2022 - 13:42:59 EST


On Sat, May 28, 2022 at 12:50 AM Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote:
>
> On Fri, May 27, 2022 at 07:01:55PM +0900, Masahiro Yamada wrote:
> > When CONFIG_LTO_CLANG or CONFIG_X86_KERNEL_IBT is enabled, objtool for
> > multi-object modules is postponed until the objects are linked together.
> >
> > Make sure to re-run objtool and re-link multi-object modules when
> > objtool is updated.
> >
> > Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
> > Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
> > Acked-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> > Tested-by: Nathan Chancellor <nathan@xxxxxxxxxx>
> > Reviewed-by: Nicolas Schier <n.schier@xxxxxx>
> > Tested-by: Sedat Dilek <sedat.dilek@xxxxxxxxx> # LLVM-14 (x86-64)
>
> Hi Masahiro,
>
> Is it also possible to rebuild vmlinux.o when objtool changes, for
> CONFIG_LTO_CLANG, CONFIG_X86_KERNEL_IBT, or CONFIG_NOINSTR_VALIDATION?
> That doesn't seem to be happening.
>
> --
> Josh

Yes.
Actually, it is already on my TODO list,
but it requires more effort.

I will aim for v5.20.







--
Best Regards
Masahiro Yamada