Merge all *.o.symversions in scripts/link-vmlinux.sh instead of incrementally merging them in the unit of built-in.a or lib.a. This is a preparation for further code cleanups. The initial patch version was implemented in a shell script, but it was slow due to the slowness of the 'cat' command [1]. This version was implemented in Perl. [1]: https://lore.kernel.org/lkml/CAK7LNATyNAu6sa-TT9JXy=BXr5d2Q5K-sp-mVXXtJDuJyi6_bA@xxxxxxxxxxxxxx/ Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx> --- scripts/Makefile.build | 10 ++------ scripts/link-vmlinux.sh | 9 ++----- scripts/merge-symvers.pl | 52 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 56 insertions(+), 15 deletions(-) create mode 100644 scripts/merge-symvers.pl diff --git a/scripts/Makefile.build b/scripts/Makefile.build index afc906cd7256..3ad1b1227371 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -434,11 +434,8 @@ endif quiet_cmd_ar_builtin = AR $@ cmd_ar_builtin = rm -f $@; $(AR) cDPrST $@ $(real-prereqs) -quiet_cmd_ar_and_symver = AR $@ - cmd_ar_and_symver = $(cmd_update_lto_symversions); $(cmd_ar_builtin) - $(obj)/built-in.a: $(real-obj-y) FORCE - $(call if_changed,ar_and_symver) + $(call if_changed,ar_builtin) # # Rule to create modules.order file @@ -458,11 +455,8 @@ $(obj)/modules.order: $(obj-m) FORCE # # Rule to compile a set of .o files into one .a file (with symbol table) # -quiet_cmd_ar_lib = AR $@ - cmd_ar_lib = $(cmd_update_lto_symversions); $(cmd_ar) - $(obj)/lib.a: $(lib-y) FORCE - $(call if_changed,ar_lib) + $(call if_changed,ar) # NOTE: # Do not replace $(filter %.o,^) with $(real-prereqs). When a single object diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index d74cee5c4326..0cc6a03f2cb1 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -57,13 +57,8 @@ gen_initcalls() gen_symversions() { info GEN .tmp_symversions.lds - rm -f .tmp_symversions.lds - - for o in ${KBUILD_VMLINUX_OBJS} ${KBUILD_VMLINUX_LIBS}; do - if [ -f ${o}.symversions ]; then - cat ${o}.symversions >> .tmp_symversions.lds - fi - done + ${PERL} scripts/merge-symvers.pl -a ${AR} -o .tmp_symversions.lds \ + ${KBUILD_VMLINUX_OBJS} ${KBUILD_VMLINUX_LIBS} } # Link of vmlinux.o used for section mismatch analysis diff --git a/scripts/merge-symvers.pl b/scripts/merge-symvers.pl new file mode 100644 index 000000000000..0bd092d24eff --- /dev/null +++ b/scripts/merge-symvers.pl @@ -0,0 +1,52 @@ +#!/usr/bin/env perl +# SPDX-License-Identifier: GPL-2.0-only + +use autodie; +use strict; +use warnings; +use Getopt::Long 'GetOptions'; + +my $ar; +my $output; + +GetOptions( + 'a|ar=s' => \$ar, + 'o|output=s' => \$output, +); + +# Collect all objects +my @objects; + +foreach (@ARGV) { + if (/\.o$/) { + # Some objects (head-y) are linked to vmlinux directly. + push(@objects, $_); + } elsif (/\.a$/) { + # Most of built-in objects are contained in built-in.a or lib.a. + # Use 'ar -t' to get the list of the contained objects. + $_ = `$ar -t $_`; + push(@objects, split(/\n/)); + } else { + die "$_: unknown file type\n"; + } +} + +open(my $out_fh, '>', "$output"); + +foreach (@objects) { + # The symbol CRCs for foo/bar/baz.o is output to foo/bar/baz.o.symversions + s/(.*)/$1.symversions/; + + if (! -e $_) { + # .symversions does not exist if the object does not contain + # EXPORT_SYMBOL at all. Skip it. + next; + } + + open(my $in_fh, '<', "$_"); + # Concatenate all the existing *.symversions files. + print $out_fh do { local $/; <$in_fh> }; + close $in_fh; +} + +close $out_fh; -- 2.30.2
