[PATCH 2/4] modpost: dump missing namespaces into a single modules.nsdeps file

From: Masahiro Yamada
Date: Tue Oct 29 2019 - 08:39:13 EST


The modpost, with the -d option given, generates per-module .ns_deps
files.

Kbuild generates per-module .mod files to carry module information.
This is convenient because Make handles multiple jobs when the -j
option is given.

On the other hand, the modpost always runs as a single thread.
I do not see a strong reason to produce separate .ns_deps files.

This commit changes the modpost to generate just one file,
modules.nsdeps, each line of which has the following format:

<module_name>: <list of missing namespaces>

Please note it contains *missing* namespaces instead of required ones.
So, modules.nsdeps is empty if the namespace dependency is all good.

This will work more efficiently because spatch will no longer process
already imported namespaces. I removed the '(if needed)' from the
nsdeps log since spatch is invoked only when needed.

This also solved the stale .ns_deps files problem reported by
Jessica Yu:

https://lkml.org/lkml/2019/10/28/467

While I was here, I improved the modpost code a little more;
I freed ns_deps_bus.p because buf_write() allocates memory.

Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
---

.gitignore | 2 +-
Documentation/dontdiff | 1 +
Makefile | 4 ++--
scripts/Makefile.modpost | 2 +-
scripts/mod/modpost.c | 44 +++++++++++++++++-----------------------
scripts/mod/modpost.h | 4 ++--
scripts/nsdeps | 21 +++++++++----------
7 files changed, 36 insertions(+), 42 deletions(-)

diff --git a/.gitignore b/.gitignore
index 70580bdd352c..72ef86a5570d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -32,7 +32,6 @@
*.lzo
*.mod
*.mod.c
-*.ns_deps
*.o
*.o.*
*.patch
@@ -61,6 +60,7 @@ modules.order
/System.map
/Module.markers
/modules.builtin.modinfo
+/modules.nsdeps

#
# RPM spec file (make rpm-pkg)
diff --git a/Documentation/dontdiff b/Documentation/dontdiff
index 9f4392876099..72fc2e9e2b63 100644
--- a/Documentation/dontdiff
+++ b/Documentation/dontdiff
@@ -179,6 +179,7 @@ mkutf8data
modpost
modules.builtin
modules.builtin.modinfo
+modules.nsdeps
modules.order
modversions.h*
nconf
diff --git a/Makefile b/Makefile
index 0ef897fd9cfd..1e3f307bd49b 100644
--- a/Makefile
+++ b/Makefile
@@ -1356,7 +1356,7 @@ endif # CONFIG_MODULES

# Directories & files removed with 'make clean'
CLEAN_DIRS += include/ksym
-CLEAN_FILES += modules.builtin.modinfo
+CLEAN_FILES += modules.builtin.modinfo modules.nsdeps

# Directories & files removed with 'make mrproper'
MRPROPER_DIRS += include/config include/generated \
@@ -1660,7 +1660,7 @@ clean: $(clean-dirs)
-o -name '*.ko.*' \
-o -name '*.dtb' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
-o -name '*.dwo' -o -name '*.lst' \
- -o -name '*.su' -o -name '*.mod' -o -name '*.ns_deps' \
+ -o -name '*.su' -o -name '*.mod' \
-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.modpost b/scripts/Makefile.modpost
index c9757b20b048..da37128c3f9f 100644
--- a/scripts/Makefile.modpost
+++ b/scripts/Makefile.modpost
@@ -66,7 +66,7 @@ __modpost:
else

MODPOST += $(subst -i,-n,$(filter -i,$(MAKEFLAGS))) -s -T - \
- $(if $(KBUILD_NSDEPS),-d)
+ $(if $(KBUILD_NSDEPS),-d modules.nsdeps)

ifeq ($(KBUILD_EXTMOD),)
MODPOST += $(wildcard vmlinux)
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index dcd90d563ce8..f7425f5d4ab0 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -38,8 +38,6 @@ static int sec_mismatch_count = 0;
static int sec_mismatch_fatal = 0;
/* ignore missing files */
static int ignore_missing_files;
-/* write namespace dependencies */
-static int write_namespace_deps;

enum export {
export_plain, export_unused, export_gpl,
@@ -2217,14 +2215,11 @@ static int check_exports(struct module *mod)
else
basename = mod->name;

- if (exp->namespace) {
- add_namespace(&mod->required_namespaces,
- exp->namespace);
-
- if (!module_imports_namespace(mod, exp->namespace)) {
- warn("module %s uses symbol %s from namespace %s, but does not import it.\n",
- basename, exp->name, exp->namespace);
- }
+ if (exp->namespace &&
+ !module_imports_namespace(mod, exp->namespace)) {
+ warn("module %s uses symbol %s from namespace %s, but does not import it.\n",
+ basename, exp->name, exp->namespace);
+ add_namespace(&mod->missing_namespaces, exp->namespace);
}

if (!mod->gpl_compatible)
@@ -2525,29 +2520,27 @@ static void write_dump(const char *fname)
free(buf.p);
}

-static void write_namespace_deps_files(void)
+static void write_namespace_deps_files(const char *fname)
{
struct module *mod;
struct namespace_list *ns;
struct buffer ns_deps_buf = {};

for (mod = modules; mod; mod = mod->next) {
- char fname[PATH_MAX];

- if (mod->skip)
+ if (mod->skip || !mod->missing_namespaces)
continue;

- ns_deps_buf.pos = 0;
+ buf_printf(&ns_deps_buf, "%s.ko:", mod->name);

- for (ns = mod->required_namespaces; ns; ns = ns->next)
- buf_printf(&ns_deps_buf, "%s\n", ns->namespace);
+ for (ns = mod->missing_namespaces; ns; ns = ns->next)
+ buf_printf(&ns_deps_buf, " %s", ns->namespace);

- if (ns_deps_buf.pos == 0)
- continue;
-
- sprintf(fname, "%s.ns_deps", mod->name);
- write_if_changed(&ns_deps_buf, fname);
+ buf_printf(&ns_deps_buf, "\n");
}
+
+ write_if_changed(&ns_deps_buf, fname);
+ free(ns_deps_buf.p);
}

struct ext_sym_list {
@@ -2560,6 +2553,7 @@ int main(int argc, char **argv)
struct module *mod;
struct buffer buf = { };
char *kernel_read = NULL;
+ char *missing_namespace_deps = NULL;
char *dump_write = NULL, *files_source = NULL;
int opt;
int err;
@@ -2567,7 +2561,7 @@ int main(int argc, char **argv)
struct ext_sym_list *extsym_iter;
struct ext_sym_list *extsym_start = NULL;

- while ((opt = getopt(argc, argv, "i:e:mnsT:o:awEd")) != -1) {
+ while ((opt = getopt(argc, argv, "i:e:mnsT:o:awEd:")) != -1) {
switch (opt) {
case 'i':
kernel_read = optarg;
@@ -2606,7 +2600,7 @@ int main(int argc, char **argv)
sec_mismatch_fatal = 1;
break;
case 'd':
- write_namespace_deps = 1;
+ missing_namespace_deps = optarg;
break;
default:
exit(1);
@@ -2654,8 +2648,8 @@ int main(int argc, char **argv)
write_if_changed(&buf, fname);
}

- if (write_namespace_deps)
- write_namespace_deps_files();
+ if (missing_namespace_deps)
+ write_namespace_deps_files(missing_namespace_deps);

if (dump_write)
write_dump(dump_write);
diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
index ad271bc6c313..fe6652535e4b 100644
--- a/scripts/mod/modpost.h
+++ b/scripts/mod/modpost.h
@@ -126,8 +126,8 @@ struct module {
struct buffer dev_table_buf;
char srcversion[25];
int is_dot_o;
- // Required namespace dependencies
- struct namespace_list *required_namespaces;
+ // Missing namespace dependencies
+ struct namespace_list *missing_namespaces;
// Actual imported namespaces
struct namespace_list *imported_namespaces;
};
diff --git a/scripts/nsdeps b/scripts/nsdeps
index dda6fbac016e..08db427a7fe5 100644
--- a/scripts/nsdeps
+++ b/scripts/nsdeps
@@ -27,15 +27,14 @@ generate_deps_for_ns() {
}

generate_deps() {
- local mod_name=`basename $@ .ko`
- local mod_file=`echo $@ | sed -e 's/\.ko/\.mod/'`
- local ns_deps_file=`echo $@ | sed -e 's/\.ko/\.ns_deps/'`
- if [ ! -f "$ns_deps_file" ]; then return; fi
- local mod_source_files=`cat $mod_file | sed -n 1p \
+ local mod=${1%.ko:}
+ shift
+ local namespaces="$*"
+ local mod_source_files=`cat $mod.mod | sed -n 1p \
| sed -e 's/\.o/\.c/g' \
| sed "s|[^ ]* *|${srctree}/&|g"`
- for ns in `cat $ns_deps_file`; do
- echo "Adding namespace $ns to module $mod_name (if needed)."
+ for ns in $namespaces; do
+ echo "Adding namespace $ns to module $mod.ko."
generate_deps_for_ns $ns $mod_source_files
# sort the imports
for source_file in $mod_source_files; do
@@ -52,7 +51,7 @@ generate_deps() {
done
}

-for f in `cat $objtree/modules.order`; do
- generate_deps $f
-done
-
+while read line
+do
+ generate_deps $line
+done < modules.nsdeps
--
2.17.1