modpost: add sym_find_with_module() helper

find_symbol() returns the first symbol found in the hash table. This
table is global, so it may return a symbol from an unexpected module.

There is a case where we want to search for a symbol with a given name
in a specified module.

Add sym_find_with_module(), which receives the module pointer as the
second argument. It is equivalent to find_module() if NULL is passed
as the module pointer.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64)

Author: masahir0y

scripts/mod/modpost.c

@@ -266,7 +266,7 @@ static void sym_add_unresolved(const char *name, struct module *mod, bool weak)
 	list_add_tail(&sym->list, &mod->unresolved_symbols);
 }
 
-static struct symbol *find_symbol(const char *name)
+static struct symbol *sym_find_with_module(const char *name, struct module *mod)
 {
 	struct symbol *s;
 
@@ -275,12 +275,17 @@ static struct symbol *find_symbol(const char *name)
 		name++;
 
 	for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
-		if (strcmp(s->name, name) == 0)
+		if (strcmp(s->name, name) == 0 && (!mod || s->module == mod))
 			return s;
 	}
 	return NULL;
 }
 
+static struct symbol *find_symbol(const char *name)
+{
+	return sym_find_with_module(name, NULL);
+}
+
 struct namespace_list {
 	struct list_head list;
 	char namespace[];