[PATCH -v2 5/7] module: Extend the MODULE_ namespace parsing

Peter Zijlstra
2024-12-02T15:11:36Z

Instead of only accepting "MODULE_${name}", extend it with a comma
separated list of module names and add tail glob support.

That is, something like: "MODULE_foo-*,bar" is now possible.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
kernel/module/main.c | 39 ++++++++++++++++++++++++++++++++++-----
scripts/mod/modpost.c | 40 ++++++++++++++++++++++++++++++++++------
2 files changed, 68 insertions(+), 11 deletions(-)

--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -1061,6 +1061,38 @@ static char *get_modinfo(const struct lo
return get_next_modinfo(info, tag, NULL);
}

+/*
+ * @namespace ~= "MODULE_foo-*,bar", match @modname to 'foo-*' or 'bar'
+ */
+static bool verify_module_namespace(const char *namespace, const char *modname)
+{
+ size_t len, modlen = strlen(modname);
+ const char *sep;
+ bool glob;
+
+ if (strncmp(namespace, "MODULE_", 7) != 0)
+ return false;
+
+ for (namespace += 7; *namespace; namespace = sep) {
+ sep = strchrnul(namespace, ',');
+ len = sep - namespace;
+
+ glob = false;
+ if (sep[-1] == '*') {
+ len--;
+ glob = true;
+ }
+
+ if (*sep)
+ sep++;
+
+ if (strncmp(namespace, modname, len) == 0 && (glob || len == modlen))
+ return true;
+ }
+
+ return false;
+}
+
static int verify_namespace_is_imported(const struct load_info *info,
const struct kernel_symbol *sym,
struct module *mod)
@@ -1070,11 +1102,8 @@ static int verify_namespace_is_imported(

namespace = kernel_symbol_namespace(sym);
if (namespace && namespace[0]) {
- /*
- * Implicitly import MODULE_${mod->name} namespace.
- */
- if (strncmp(namespace, "MODULE_", 7) == 0 &&
- strcmp(namespace+7, mod->name) == 0)
+
+ if (verify_module_namespace(namespace, mod->name))
return 0;

for_each_modinfo_entry(imported_namespace, info, "import_ns") {
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -1565,7 +1565,6 @@ static const char *mod_basename(const ch

static void read_symbols(const char *modname)
{
- char module_namespace[MODULE_NAME_LEN + 8];
const char *symname;
char *version;
char *license;
@@ -1601,10 +1600,6 @@ static void read_symbols(const char *mod
namespace = get_next_modinfo(&info, "import_ns", namespace))
add_namespace(&mod->imported_namespaces, namespace);

- snprintf(module_namespace, sizeof(module_namespace), "MODULE_%s",
- mod_basename(mod->name));
- add_namespace(&mod->imported_namespaces, module_namespace);
-
if (extra_warn && !get_modinfo(&info, "description"))
warn("missing MODULE_DESCRIPTION() in %s\n", modname);
}
@@ -1687,6 +1682,38 @@ void buf_write(struct buffer *buf, const
buf->pos += len;
}

+/*
+ * @namespace ~= "MODULE_foo-*,bar", match @modname to 'foo-*' or 'bar'
+ */
+static bool module_namespace(const char *namespace, const char *modname)
+{
+ size_t len, modlen = strlen(modname);
+ const char *sep;
+ bool glob;
+
+ if (strncmp(namespace, "MODULE_", 7) != 0)
+ return false;
+
+ for (namespace += 7; *namespace; namespace = sep) {
+ sep = strchrnul(namespace, ',');
+ len = sep - namespace;
+
+ glob = false;
+ if (sep[-1] == '*') {
+ len--;
+ glob = true;
+ }
+
+ if (*sep)
+ sep++;
+
+ if (strncmp(namespace, modname, len) == 0 && (glob || len == modlen))
+ return true;
+ }
+
+ return false;
+}
+
static void check_exports(struct module *mod)
{
struct symbol *s, *exp;
@@ -1714,7 +1741,8 @@ static void check_exports(struct module

basename = mod_basename(mod->name);

- if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) {
+ if (!module_namespace(exp->namespace, basename) &&
+ !contains_namespace(&mod->imported_namespaces, exp->namespace)) {
modpost_log(!allow_missing_ns_imports,
"module %s uses symbol %s from namespace %s, but does not import it.\n",
basename, exp->name, exp->namespace);