It took me a while to understand the intent of "exp->module == mod". This code goes back to 2003 (pre-git era). The commit is not in this git repository, and might be worth a little explanation. You can add EXPORT_SYMBOL() with no definition in the same file (but you need to put a declaration). int foo(void); EXPORT_SYMBOL(foo); This is typical when EXPORT_SYMBOL() is defined in a C file, but the actual implementation is in a separate assembly file. In old days, EXPORT_SYMBOL() were only available in C files (but this limitation does not exist any more). Add a separate, clearer message if an exported symbol has no definition. It should be an error even if KBUILD_MODPOST_WARN is given. [1]: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=2763b6bcb96e6a38a2fe31108fe5759ec5bcc80a Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx> --- scripts/mod/modpost.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index c7cfeeb088f7..969a081dba62 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -2147,13 +2147,18 @@ static void check_exports(struct module *mod) for (s = mod->unres; s; s = s->next) { const char *basename; exp = find_symbol(s->name); - if (!exp || exp->module == mod) { + if (!exp) { if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS) modpost_log(warn_unresolved ? LOG_WARN : LOG_ERROR, "\"%s\" [%s.ko] undefined!\n", s->name, mod->name); continue; } + if (exp->module == mod) { + error("\"%s\" [%s.ko] was exported without definition\n", + s->name, mod->name); + continue; + } basename = strrchr(mod->name, '/'); if (basename) basename++; -- 2.32.0
