[PATCH v10 06/11] modpost: Add -b option for emitting built-in aliases

From: Allen Webb
Date: Thu Apr 06 2023 - 15:01:41 EST


This adds a command line option for writing the match-id based built-in
aliases to a file. A future patch extends file2alias.c to support this
command.

The -b option accepts the output path as a parameter and requires
vmlinuz.o to be one of the input files for the aliases to be found.

Signed-off-by: Allen Webb <allenwebb@xxxxxxxxxx>
---
scripts/mod/modpost.c | 30 ++++++++++++++++++++++++++++--
scripts/mod/modpost.h | 1 +
2 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index efff8078e395..2e452aec0fc6 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -2173,6 +2173,19 @@ static void write_if_changed(struct buffer *b, const char *fname)
write_buf(b, fname);
}

+/* Write the builtin aliases to the specified file. */
+static void write_builtin(const char *fname)
+{
+ struct buffer buf = { };
+ struct module *mod;
+
+ list_for_each_entry(mod, &modules, list)
+ buf_write(&buf, mod->modalias_buf.p, mod->modalias_buf.pos);
+
+ write_if_changed(&buf, fname);
+ free(buf.p);
+}
+
static void write_vmlinux_export_c_file(struct module *mod)
{
struct buffer buf = { };
@@ -2329,13 +2342,23 @@ int main(int argc, char **argv)
{
struct module *mod;
char *missing_namespace_deps = NULL;
- char *dump_write = NULL, *files_source = NULL;
+ char *builtin_write = NULL, *dump_write = NULL, *files_source = NULL;
int opt;
LIST_HEAD(dump_lists);
struct dump_list *dl, *dl2;

- while ((opt = getopt(argc, argv, "ei:mnT:o:awENd:")) != -1) {
+ while ((opt = getopt(argc, argv, "b:ei:mnT:o:awENd:")) != -1) {
switch (opt) {
+ case 'b':
+ /*
+ * Writes the match-id based built-in module aliases to
+ * the specified path.
+ *
+ * vmlinuz.o needs to be one of the input files for the
+ * aliases to be found.
+ */
+ builtin_write = optarg;
+ break;
case 'e':
external_module = true;
break;
@@ -2398,6 +2421,9 @@ int main(int argc, char **argv)
write_mod_c_file(mod);
}

+ if (builtin_write)
+ write_builtin(builtin_write);
+
if (missing_namespace_deps)
write_namespace_deps_files(missing_namespace_deps);

diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
index 34fe5fc0b02c..c55a6aeb46bf 100644
--- a/scripts/mod/modpost.h
+++ b/scripts/mod/modpost.h
@@ -123,6 +123,7 @@ struct module {
bool has_init;
bool has_cleanup;
struct buffer dev_table_buf;
+ struct buffer modalias_buf;
char srcversion[25];
// Missing namespace dependencies
struct list_head missing_namespaces;
--
2.39.2