[PATCH 2/6] module: include struct modversion_info in module version check

[PATCH 2/6] module: include struct modversion_info in module version check

[Rusty Russell]

With CONFIG_MODVERSIONS, we version 'struct module' using a dummy
export, but other things matter too: we are about to change 'struct
modversion_info' which means the layout of the __versions section
would change, and this should be reflected in modversions.

So we rename 'struct_module' to 'module_layout' and include the
'struct modversion_info' in the signature.  Now it's general we can
add others later on without confusion.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 kernel/module.c       |   11 ++++++-----
 scripts/mod/modpost.c |    4 ++--
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/kernel/module.c b/kernel/module.c
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1023,9 +1023,9 @@ static inline int check_modstruct_versio
 {
 	const unsigned long *crc;
 
-	if (IS_ERR_VALUE(find_symbol("struct_module", NULL, &crc, true, false)))
+	if (IS_ERR_VALUE(find_symbol("module_layout", NULL, &crc, true, false)))
 		BUG();
-	return check_version(sechdrs, versindex, "struct_module", mod, crc);
+	return check_version(sechdrs, versindex, "module_layout", mod, crc);
 }
 
 /* First part is kernel version, which we ignore if module has crcs. */
@@ -2778,9 +2778,10 @@ void print_modules(void)
 }
 
 #ifdef CONFIG_MODVERSIONS
-/* Generate the signature for struct module here, too, for modversions. */
-void struct_module(struct module *mod) { return; }
-EXPORT_SYMBOL(struct_module);
+/* Generate the signature for module structures here, too, for modversions.
+ * If these change, we don't want to try to parse the module. */
+void module_layout(struct module *mod, struct modversion_info *ver) { return; }
+EXPORT_SYMBOL(module_layout);
 #endif
 
 #ifdef CONFIG_MARKERS
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -1604,12 +1604,12 @@ static void read_symbols(char *modname)
 
 	parse_elf_finish(&info);
 
-	/* Our trick to get versioning for struct_module - it's
+	/* Our trick to get versioning for module struct etc. - it's
 	 * never passed as an argument to an exported function, so
 	 * the automatic versioning doesn't pick it up, but it's really
 	 * important anyhow */
 	if (modversions)
-		mod->unres = alloc_symbol("struct_module", 0, mod->unres);
+		mod->unres = alloc_symbol("module_layout", 0, mod->unres);
 }
 
 #define SZ 500