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kbuild: remove partial section mismatch detection for built-in.a

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When built-in.o was incrementally linked with 'ld -r', the section
mismatch analysis for the individual built-in.o was possible when
CONFIG_DEBUG_SECTION_MISMATCH was enabled.

With the migration to the thin archive, built-in.a (former, built-in.o)
is no longer an ELF file.  So, the modpost does nothing useful.
scripts/mod/modpost.c just checks the header to bail out, as follows:

        /* Is this a valid ELF file? */
        if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
            (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
            (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
            (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
                /* Not an ELF file - silently ignore it */
                return 0;
        }

We have the full analysis in the final link stage anyway, so we would
not miss the section mismatching.

I do not see a good reason to require extra linking only for the
purpose of the per-directory analysis.  Just get rid of this part.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
This commit is contained in:
Masahiro Yamada 2018-03-19 20:26:11 +09:00
parent f605005a50
commit 7657f60e8f
1 changed files with 1 additions and 2 deletions
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3
scripts/Makefile.build
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@ -456,8 +456,7 @@ quiet_cmd_link_o_target = AR $@
# If the list of objects to link is empty, just create an empty built-in.a
cmd_link_o_target = $(if $(strip $(real-obj-y)),\
$(cmd_make_builtin) $@ $(filter $(real-obj-y), $^) \
$(cmd_secanalysis),\
$(cmd_make_builtin) $@ $(filter $(real-obj-y), $^), \
$(cmd_make_empty_builtin) $@)
$(builtin-target): $(real-obj-y) FORCE