Re: [PATCH 6/7] kbuild: move include/config/ksym/* to include/ksym/*

From: Masahiro Yamada
Date: Thu Mar 15 2018 - 06:05:46 EST


2018-03-15 3:47 GMT+09:00 Nicolas Pitre <nicolas.pitre@xxxxxxxxxx>:
> On Thu, 15 Mar 2018, Masahiro Yamada wrote:
>
>> The idea of using fixdep was inspired by Kconfig, but autoksyms
>> is unrelated to Kconfig. So, I want to get those touched files
>> out of include/config/. The directory include/ksym/ is removed
>> by "make clean". We do not need to keep it for external module
>> building.
>
> It could be argued that include/config/ is not strictly containing
> configuration data either and is slightly misleading.

But, slightly related to configuration, IMHO.
At least they carry timestamps that are updated
when kernel configuration is changed.

The difference between include/config/ and include/ksym/ is that
files under include/config/ are necessary for building
external modules (so should be cleaned away by mrproper)
whereas include/ksym/ is unnecessary for external modules
since vmlinux and in-kernel modules do not depend on
external modules.


I wonder if trimming symbols makes sense for external modules.

EXPORT_SYMBOL(_GPL) in external modules are always trimmed
since vmlinux and in-kernel modules never rely on them.

If an external module exports symbols,
it expects they will be used by other external modules.

So, the patch like follows make sense?




kbuild: do not trim symbols in external modules

diff --git a/Makefile b/Makefile
index 0a7bab6..bdf565e 100644
--- a/Makefile
+++ b/Makefile
@@ -998,6 +998,7 @@ autoksyms_recursive: $(vmlinux-deps)
# (this can be evaluated only once include/config/auto.conf has been included)
ifdef CONFIG_TRIM_UNUSED_KSYMS
KBUILD_MODULES := 1
+ export KBUILD_TRIM_UNUSED_KSYMS := 1
endif

autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index 045971e..3249d5f 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -345,7 +345,7 @@ if_changed_dep = $(if $(strip $(any-prereq)
$(arg-check) ), \
@set -e; \
$(cmd_and_fixdep), @:)

-ifndef CONFIG_TRIM_UNUSED_KSYMS
+ifndef KBUILD_TRIM_UNUSED_KSYMS

cmd_and_fixdep = \
$(echo-cmd) $(cmd_$(1)); \




> What about moving include/config/ and include/ksym/ under
> include/depfiles/ ? In fact that could even be
> include/generated/depfiles/config/ and include/generated/depfiles/ksym/
> to trim down the top include directory.
>
>> Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
>> ---
>>
>> .gitignore | 1 +
>> Makefile | 2 +-
>> scripts/Kbuild.include | 2 +-
>> scripts/adjust_autoksyms.sh | 2 +-
>> scripts/basic/fixdep.c | 8 ++++----
>> 5 files changed, 8 insertions(+), 7 deletions(-)
>>
>> diff --git a/.gitignore b/.gitignore
>> index 1be78fd..85bcc26 100644
>> --- a/.gitignore
>> +++ b/.gitignore
>> @@ -87,6 +87,7 @@ modules.builtin
>> #
>> include/config
>> include/generated
>> +include/ksym
>> arch/*/include/generated
>>
>> # stgit generated dirs
>> diff --git a/Makefile b/Makefile
>> index e60b16f..1dab647 100644
>> --- a/Makefile
>> +++ b/Makefile
>> @@ -1327,7 +1327,7 @@ endif # CONFIG_MODULES
>> # make distclean Remove editor backup files, patch leftover files and the like
>>
>> # Directories & files removed with 'make clean'
>> -CLEAN_DIRS += $(MODVERDIR)
>> +CLEAN_DIRS += $(MODVERDIR) include/ksym
>>
>> # Directories & files removed with 'make mrproper'
>> MRPROPER_DIRS += include/config usr/include include/generated \
>> diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
>> index 065324a..045971e 100644
>> --- a/scripts/Kbuild.include
>> +++ b/scripts/Kbuild.include
>> @@ -368,7 +368,7 @@ ksym_dep_filter = \
>> $(CPP) $(call flags_nodeps,a_flags) -D__KSYM_DEPS__ $< ;; \
>> boot*|build*|cpp_its_S|*cpp_lds_S|dtc|host*|vdso*) : ;; \
>> *) echo "Don't know how to preprocess $(1)" >&2; false ;; \
>> - esac | tr ";" "\n" | sed -rn 's/^.*=== __KSYM_(.*) ===.*$$/KSYM_\1/p'
>> + esac | tr ";" "\n" | sed -rn 's/^.*=== __KSYM_(.*) ===.*$$/\1/p'
>>
>> cmd_and_fixdep = \
>> $(echo-cmd) $(cmd_$(1)); \
>> diff --git a/scripts/adjust_autoksyms.sh b/scripts/adjust_autoksyms.sh
>> index a52210b..7bb3618 100755
>> --- a/scripts/adjust_autoksyms.sh
>> +++ b/scripts/adjust_autoksyms.sh
>> @@ -81,7 +81,7 @@ sort "$cur_ksyms_file" "$new_ksyms_file" | uniq -u |
>> sed -n 's/^#define __KSYM_\(.*\) 1/\1/p' | tr "A-Z_" "a-z/" |
>> while read sympath; do
>> if [ -z "$sympath" ]; then continue; fi
>> - depfile="include/config/ksym/${sympath}.h"
>> + depfile="include/ksym/${sympath}.h"
>> mkdir -p "$(dirname "$depfile")"
>> touch "$depfile"
>> echo $((count += 1))
>> diff --git a/scripts/basic/fixdep.c b/scripts/basic/fixdep.c
>> index 449b68c..f387538 100644
>> --- a/scripts/basic/fixdep.c
>> +++ b/scripts/basic/fixdep.c
>> @@ -113,11 +113,11 @@ static void usage(void)
>> /*
>> * Print out a dependency path from a symbol name
>> */
>> -static void print_config(const char *m, int slen)
>> +static void print_dep(const char *m, int slen, const char *dir)
>> {
>> int c, i;
>>
>> - printf(" $(wildcard include/config/");
>> + printf(" $(wildcard %s/", dir);
>> for (i = 0; i < slen; i++) {
>> c = m[i];
>> if (c == '_')
>> @@ -140,7 +140,7 @@ static void do_extra_deps(void)
>> fprintf(stderr, "fixdep: bad data on stdin\n");
>> exit(1);
>> }
>> - print_config(buf, len - 1);
>> + print_dep(buf, len - 1, "include/ksym");
>> }
>> }
>>
>> @@ -208,7 +208,7 @@ static void use_config(const char *m, int slen)
>> return;
>>
>> define_config(m, slen, hash);
>> - print_config(m, slen);
>> + print_dep(m, slen, "include/config");
>> }
>>
>> /* test if s ends in sub */
>> --
>> 2.7.4
>>
>>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html



--
Best Regards
Masahiro Yamada