Re: [PATCH v5 1/4] kbuild: add mod(name,file)_flags to assembler flags for module objects

[Steven Rostedt <rostedt@goodmis.org>]

On Mon, 15 Jul 2024 23:10:42 -0400
Kris Van Hees <kris.van.hees@oracle.com> wrote:


As mentioned before, should start off with the goal.

  In order to create the file at build time, modules.builtin.ranges, that
  contains the range of addresses for all built-in modules, there needs to
  be a way to identify what code is compiled into modules.

  To identify what code is compiled into modules during a kernel build, ...



> In order to be able to identify what code is compiled into modules (even
> built-in modules) during a kernel build, one can look for the presence
> of the -DKBUILD_MODFILE and -DKBUILD_MODNAME options in the compile
> command lines.  A simple grep in .*.cmd files for those options is
> sufficient for this.
> 
> Unfortunately, these options are only passed when compiling C source files.
> Various modules also include objects built from assembler source, and these
> options are not passed in that case.
> 
> Adding $(modfile_flags) to modkern_aflags (similar to modkern_cflahs), and
> adding $(modname_flags) to a_flags (similar to c_flags) makes it possible
> to identify which objects are compiled into modules for both C and
> assembler soure files.

The rest looks good.

Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>

-- Steve

> 
> Signed-off-by: Kris Van Hees <kris.van.hees@oracle.com>
> ---
>  scripts/Makefile.lib | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
> index 9f06f6aaf7fc..f4aec3553ff2 100644
> --- a/scripts/Makefile.lib
> +++ b/scripts/Makefile.lib
> @@ -238,7 +238,7 @@ modkern_rustflags =                                              \
>  
>  modkern_aflags = $(if $(part-of-module),				\
>  			$(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE),	\
> -			$(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL))
> +			$(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL) $(modfile_flags))
>  
>  c_flags        = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE)     \
>  		 -include $(srctree)/include/linux/compiler_types.h       \
> @@ -248,7 +248,7 @@ c_flags        = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE)     \
>  rust_flags     = $(_rust_flags) $(modkern_rustflags) @$(objtree)/include/generated/rustc_cfg
>  
>  a_flags        = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE)     \
> -		 $(_a_flags) $(modkern_aflags)
> +		 $(_a_flags) $(modkern_aflags) $(modname_flags)
>  
>  cpp_flags      = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE)     \
>  		 $(_cpp_flags)