module: include other structures in module version check

With CONFIG_MODVERSIONS, we version 'struct module' using a dummy
export, but other things matter too:

1) 'struct modversion_info' determines the layout of the __versions section,
2) 'struct kernel_param' determines the layout of the __params section,
3) 'struct kernel_symbol' determines __ksymtab*.
4) 'struct marker' determines __markers.
5) 'struct tracepoint' determines __tracepoints.

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

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

2 files changed, 15 insertions, 7 deletions

diff --git a/kernel/module.c b/kernel/module.c
index 784bf6d..e8cf636 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1052,9 +1052,9 @@ static inline int check_modstruct_version(Elf_Shdr *sechdrs,
 {
 	const unsigned long *crc;
 
-	if (!find_symbol("struct_module", NULL, &crc, true, false))
+	if (!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. */
@@ -2858,9 +2858,17 @@ 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 all relevant module structures here.
+ * If these change, we don't want to try to parse the module. */
+void module_layout(struct module *mod,
+		   struct modversion_info *ver,
+		   struct kernel_param *kp,
+		   struct kernel_symbol *ks,
+		   struct marker *marker,
+		   struct tracepoint *tp)
+{
+}
+EXPORT_SYMBOL(module_layout);
 #endif
 
 #ifdef CONFIG_MARKERS
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 7e62303..8cc7061 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -1607,12 +1607,12 @@ 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