@@ -208,6 +208,16 @@ config ASM_MODVERSIONS
assembly. This can be enabled only when the target architecture
supports it.
+config EXTENDED_MODVERSIONS
+ bool "Extended Module Versioning Support"
+ depends on MODVERSIONS
+ help
+ This enables extended MODVERSIONs support, allowing long symbol
+ names to be versioned.
+
+ The most likely reason you would enable this is to enable Rust
+ support. If unsure, say N.
+
config MODULE_SRCVERSION_ALL
bool "Source checksum for all modules"
help
@@ -43,6 +43,7 @@ MODPOST = scripts/mod/modpost
modpost-args = \
$(if $(CONFIG_MODULES),-M) \
$(if $(CONFIG_MODVERSIONS),-m) \
+ $(if $(CONFIG_EXTENDED_MODVERSIONS),-x) \
$(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \
$(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \
$(if $(KBUILD_MODPOST_WARN),-w) \
@@ -32,6 +32,8 @@ static bool module_enabled;
static bool modversions;
/* Is CONFIG_MODULE_SRCVERSION_ALL set? */
static bool all_versions;
+/* Is CONFIG_EXTENDED_MODVERSIONS set? */
+static bool extended_modversions;
/* If we are modposting external module set to 1 */
static bool external_module;
/* Only warn about unresolved symbols */
@@ -1817,6 +1819,52 @@ static void add_exported_symbols(struct buffer *buf, struct module *mod)
}
}
+/**
+ * Record CRCs for unresolved symbols, supporting long names
+ */
+static void add_extended_versions(struct buffer *b, struct module *mod)
+{
+ struct symbol *s;
+
+ if (!extended_modversions)
+ return;
+
+ buf_printf(b, "\n");
+ buf_printf(b, "static const s32 ____version_ext_crcs[]\n");
+ buf_printf(b, "__used __section(\"__version_ext_crcs\") = {\n");
+ list_for_each_entry(s, &mod->unresolved_symbols, list) {
+ if (!s->module)
+ continue;
+ if (!s->crc_valid) {
+ /*
+ * We already warned on this when producing the legacy
+ * modversions table.
+ */
+ continue;
+ }
+ buf_printf(b, "\t%#8x,\n", s->crc);
+ }
+ buf_printf(b, "};\n");
+
+ buf_printf(b, "static const char ____version_ext_names[]\n");
+ buf_printf(b, "__used __section(\"__version_ext_names\") =\n");
+ list_for_each_entry(s, &mod->unresolved_symbols, list) {
+ if (!s->module)
+ continue;
+ if (!s->crc_valid) {
+ /*
+ * We already warned on this when producing the legacy
+ * modversions table.
+ * We need to skip its name too, as the indexes in
+ * both tables need to align.
+ */
+ continue;
+ }
+ buf_printf(b, "\t\"%s\\0\"\n", s->name);
+ }
+ buf_printf(b, ";\n");
+}
+
/**
* Record CRCs for unresolved symbols
**/
@@ -1840,9 +1888,14 @@ static void add_versions(struct buffer *b, struct module *mod)
continue;
}
if (strlen(s->name) >= MODULE_NAME_LEN) {
- error("too long symbol \"%s\" [%s.ko]\n",
- s->name, mod->name);
- break;
+ if (extended_modversions)
+ /* this symbol will only be in the extended info */
+ continue;
+ else {
+ error("too long symbol \"%s\" [%s.ko]\n",
+ s->name, mod->name);
+ break;
+ }
}
buf_printf(b, "\t{ %#8x, \"%s\" },\n",
s->crc, s->name);
@@ -1972,6 +2025,7 @@ static void write_mod_c_file(struct module *mod)
add_header(&buf, mod);
add_exported_symbols(&buf, mod);
add_versions(&buf, mod);
+ add_extended_versions(&buf, mod);
add_depends(&buf, mod);
add_moddevtable(&buf, mod);
add_srcversion(&buf, mod);
@@ -2130,7 +2184,7 @@ int main(int argc, char **argv)
LIST_HEAD(dump_lists);
struct dump_list *dl, *dl2;
- while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:")) != -1) {
+ while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:x")) != -1) {
switch (opt) {
case 'e':
external_module = true;
@@ -2179,6 +2233,9 @@ int main(int argc, char **argv)
case 'd':
missing_namespace_deps = optarg;
break;
+ case 'x':
+ extended_modversions = true;
+ break;
default:
exit(1);
}
Generate both the existing modversions format and the new extended one when running modpost. Presence of this metadata in the final .ko is guarded by CONFIG_EXTENDED_MODVERSIONS. We no longer generate an error on long symbols in modpost if CONFIG_EXTENDED_MODVERSIONS is set, as they can now be appropriately encoded in the extended section. These symbols will be skipped in the previous encoding. An error will still be generated if CONFIG_EXTENDED_MODVERSIONS is not set. Signed-off-by: Matthew Maurer <mmaurer@google.com> --- kernel/module/Kconfig | 10 ++++++++ scripts/Makefile.modpost | 1 + scripts/mod/modpost.c | 65 +++++++++++++++++++++++++++++++++++++++++++++--- 3 files changed, 72 insertions(+), 4 deletions(-)