Re: [RFC 00/31] objtool, livepatch: Livepatch module generation

[Joe Lawrence]

On Fri, Sep 06, 2024 at 06:47:06PM -0700, Josh Poimboeuf wrote:
> 
> Normally I build objtool with
> 
>   make tools/objtool
> 
> or just
> 
>   make
> 
> Those use the objtool Makefile without all the extra kernel flags.
> 
> How do you normally build objtool?
>

Usually as part of the kernel build, for example:

  $ git clone \
      git://git.kernel.org/pub/scm/linux/kernel/git/jpoimboe/linux.git \
      --branch klp-build-rfc

  $ cd linux && make -s defconfig && make -j$(nproc)

Results in the same implicit function declaration and uninitialized
variables errors.  (Thanks to tools/objtool/Makefile's OBJTOOL_CFLAGS :=
-Werror I believe.)

Re-reading my report, I thought building the two object files (check.o
and klp-diff.o) individually would report their respective problems, but
I see now that the invocation seems to want to build all the .o's, so
disregard that build wrinkle.  I almost always build objtool by a
top-level `make` or `make tools/objtool`, so sorry for any confusion.

--
Joe