[PATCH v2 08/10] kbuild: split the second line of *.mod into *.usyms

From: Masahiro Yamada
Date: Tue Apr 05 2022 - 17:18:33 EST


The *.mod files have two lines; the first line lists the member objects
of the module, and the second line, if CONFIG_TRIM_UNUSED_KSYMS=y, lists
the undefined symbols.

These two are orthogonal. For further cleanups, lets' split the second
line out to separate *.usyms files, which are generated only when
CONFIG_TRIM_UNUSED_KSYMS=y.

Previously, the list of undefined symbols ended up with a very long
line, but now symbols are split by new lines.

Use 'sed' like we did before commit 7d32358be8ac ("kbuild: avoid split
lines in .mod files").

Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
---

Changes in v2:
- new

.gitignore | 1 +
Makefile | 2 +-
scripts/Makefile.build | 17 +++++++++--------
scripts/adjust_autoksyms.sh | 2 +-
scripts/gen_autoksyms.sh | 18 +++++++++++-------
scripts/mod/sumversion.c | 11 ++---------
6 files changed, 25 insertions(+), 26 deletions(-)

diff --git a/.gitignore b/.gitignore
index 7afd412dadd2..265959544978 100644
--- a/.gitignore
+++ b/.gitignore
@@ -45,6 +45,7 @@
*.symversions
*.tab.[ch]
*.tar
+*.usyms
*.xz
*.zst
Module.symvers
diff --git a/Makefile b/Makefile
index d9336e783be3..82ee893909e9 100644
--- a/Makefile
+++ b/Makefile
@@ -1848,7 +1848,7 @@ clean: $(clean-dirs)
-o -name '*.ko.*' \
-o -name '*.dtb' -o -name '*.dtbo' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
-o -name '*.dwo' -o -name '*.lst' \
- -o -name '*.su' -o -name '*.mod' \
+ -o -name '*.su' -o -name '*.mod' -o -name '*.usyms' \
-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
-o -name '*.lex.c' -o -name '*.tab.[ch]' \
-o -name '*.asn1.[ch]' \
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 63625877aeae..d934bdf84de4 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -85,7 +85,8 @@ ifdef need-builtin
targets-for-builtin += $(obj)/built-in.a
endif

-targets-for-modules := $(patsubst %.o, %.mod, $(filter %.o, $(obj-m)))
+targets-for-modules := $(foreach suffix, mod $(if $(CONFIG_TRIM_UNUSED_KSYMS), usyms), \
+ $(patsubst %.o, %.$(suffix), $(filter %.o, $(obj-m))))

ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
targets-for-modules += $(patsubst %.o, %.prelink.o, $(filter %.o, $(obj-m)))
@@ -260,9 +261,6 @@ endif
ifdef CONFIG_TRIM_UNUSED_KSYMS
cmd_gen_ksymdeps = \
$(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd
-
-# List module undefined symbols
-undefined_syms = $(NM) $< | $(AWK) '$$1 == "U" { printf("%s%s", x++ ? " " : "", $$2) }';
endif

define rule_cc_o_c
@@ -309,14 +307,17 @@ endif

multi-m-prereqs = $(sort $(addprefix $(obj)/, $($*-objs) $($*-y) $($*-m)))

-cmd_mod = { \
- echo $(if $(multi-m-prereqs), $(multi-m-prereqs), $(@:.mod=.o)); \
- $(undefined_syms) echo; \
- } > $@
+cmd_mod = echo $(if $(multi-m-prereqs), $(multi-m-prereqs), $(@:.mod=.o)) > $@

$(obj)/%.mod: $(obj)/%$(mod-prelink-ext).o FORCE
$(call if_changed,mod)

+# List module undefined symbols
+cmd_undefined_syms = $(NM) $< | sed -n 's/^ *U //p' > $@
+
+$(obj)/%.usyms: $(obj)/%$(mod-prelink-ext).o FORCE
+ $(call if_changed,undefined_syms)
+
quiet_cmd_cc_lst_c = MKLST $@
cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
$(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
diff --git a/scripts/adjust_autoksyms.sh b/scripts/adjust_autoksyms.sh
index 59fdb875e818..f1b5ac818411 100755
--- a/scripts/adjust_autoksyms.sh
+++ b/scripts/adjust_autoksyms.sh
@@ -35,7 +35,7 @@ case "$KBUILD_VERBOSE" in
esac

# Generate a new symbol list file
-$CONFIG_SHELL $srctree/scripts/gen_autoksyms.sh "$new_ksyms_file"
+$CONFIG_SHELL $srctree/scripts/gen_autoksyms.sh --modorder "$new_ksyms_file"

# Extract changes between old and new list and touch corresponding
# dependency files.
diff --git a/scripts/gen_autoksyms.sh b/scripts/gen_autoksyms.sh
index 120225c541c5..faacf7062122 100755
--- a/scripts/gen_autoksyms.sh
+++ b/scripts/gen_autoksyms.sh
@@ -2,13 +2,10 @@
# SPDX-License-Identifier: GPL-2.0-only

# Create an autoksyms.h header file from the list of all module's needed symbols
-# as recorded on the second line of *.mod files and the user-provided symbol
-# whitelist.
+# as recorded in *.usyms files and the user-provided symbol whitelist.

set -e

-output_file="$1"
-
# Use "make V=1" to debug this script.
case "$KBUILD_VERBOSE" in
*1*)
@@ -16,6 +13,15 @@ case "$KBUILD_VERBOSE" in
;;
esac

+read_modorder=
+
+if [ "$1" = --modorder ]; then
+ shift
+ read_modorder=1
+fi
+
+output_file="$1"
+
needed_symbols=

# Special case for modversions (see modpost.c)
@@ -41,10 +47,8 @@ cat > "$output_file" << EOT

EOT

-[ -f modules.order ] && modlist=modules.order || modlist=/dev/null
-
{
- sed 's/ko$/mod/' $modlist | xargs -n1 sed -n -e '2p'
+ [ -n "${read_modorder}" ] && sed 's/ko$/usyms/' modules.order | xargs cat
echo "$needed_symbols"
[ -n "$ksym_wl" ] && cat "$ksym_wl"
} | sed -e 's/ /\n/g' | sed -n -e '/^$/!p' |
diff --git a/scripts/mod/sumversion.c b/scripts/mod/sumversion.c
index 905c0ec291e1..0125698f2037 100644
--- a/scripts/mod/sumversion.c
+++ b/scripts/mod/sumversion.c
@@ -387,7 +387,7 @@ static int parse_source_files(const char *objfile, struct md4_ctx *md)
/* Calc and record src checksum. */
void get_src_version(const char *modname, char sum[], unsigned sumlen)
{
- char *buf, *pos, *firstline;
+ char *buf;
struct md4_ctx md;
char *fname;
char filelist[PATH_MAX + 1];
@@ -397,15 +397,8 @@ void get_src_version(const char *modname, char sum[], unsigned sumlen)

buf = read_text_file(filelist);

- pos = buf;
- firstline = get_line(&pos);
- if (!firstline) {
- warn("bad ending versions file for %s\n", modname);
- goto free;
- }
-
md4_init(&md);
- while ((fname = strsep(&firstline, " "))) {
+ while ((fname = strsep(&buf, " \n"))) {
if (!*fname)
continue;
if (!(is_static_library(fname)) &&
--
2.32.0