[PATCH] modpost: abort if a module name is too long

[Xie XiuQi]

From: Wanlong Gao <gaowanlong@xxxxxxxxxx>

Module name has a limited length, but currently the build system
allows the build finishing even if the module name is too long.

  CC      /root/kprobe_example/abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz.mod.o
/root/kprobe_example/abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz.mod.c:9:2:
warning: initializer-string for array of chars is too long [enabled by default]
  .name = KBUILD_MODNAME,
  ^

but it's merely a warning.

This patch adds the check of the module name length in modpost and stops
the build properly.

Signed-off-by: Wanlong Gao <gaowanlong@xxxxxxxxxx>
Signed-off-by: Xie XiuQi <xiexiuqi@xxxxxxxxxx>
---
 scripts/mod/modpost.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 30d752a..db11c57 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -2166,6 +2166,17 @@ static int add_versions(struct buffer *b, struct module *mod)
 {
 	struct symbol *s, *exp;
 	int err = 0;
+	const char *mod_name;
+
+	mod_name = strrchr(mod->name, '/');
+	if (mod_name == NULL)
+		mod_name = mod->name;
+	else
+		mod_name++;
+	if (strlen(mod_name) >= MODULE_NAME_LEN) {
+		merror("module name is too long [%s.ko]\n", mod->name);
+		return 1;
+	}
 
 	for (s = mod->unres; s; s = s->next) {
 		exp = find_symbol(s->name);
-- 
1.8.3.1