kbuild: fail kernel compilation in case of unresolved module symbols

At stage 2 modpost utility is used to check modules. In case of unresolved symbols modpost only prints warning. IMHO it is a good idea to fail compilation process in case of unresolved symbols (at least in modules coming with kernel), since usually such errors are left unnoticed, but kernel modules are broken. - new option '-w' is added to modpost: if option is specified, modpost only warns about unresolved symbols - modpost is called with '-w' for external modules in Makefile.modpost Signed-off-by: Andrey Mirkin <amirkin@sw.ru> Signed-off-by: Kirill Korotaev <dev@openvz.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

kbuild: fail kernel compilation in case of unresolved module symbols
At stage 2 modpost utility is used to check modules. In case of unresolved symbols modpost only prints warning. IMHO it is a good idea to fail compilation process in case of unresolved symbols (at least in modules coming with kernel), since usually such errors are left unnoticed, but kernel modules are broken. - new option '-w' is added to modpost: if option is specified, modpost only warns about unresolved symbols - modpost is called with '-w' for external modules in Makefile.modpost Signed-off-by: Andrey Mirkin <amirkin@sw.ru> Signed-off-by: Kirill Korotaev <dev@openvz.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Kirill Korotaev · Sam Ravnborg
1 parent 2212692913
Showing 2 changed files with 20 additions and 6 deletions Side-by-side Diff
scripts/Makefile.modpost
scripts/mod/modpost.c
@@ -58,6 +58,7 @@
 	$(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile) \
 	$(if $(KBUILD_EXTMOD),-I $(modulesymfile)) \
 	$(if $(KBUILD_EXTMOD),-o $(modulesymfile)) \
+	$(if $(KBUILD_EXTMOD),-w) \
 	$(wildcard vmlinux) $(filter-out FORCE,$^)
  
 PHONY += __modpost
@@ -23,6 +23,8 @@
 static int all_versions = 0;
 /* If we are modposting external module set to 1 */
 static int external_module = 0;
+/* Only warn about unresolved symbols */
+static int warn_unresolved = 0;
 /* How a symbol is exported */
 enum export {
 	export_plain,      export_unused,     export_gpl,
  
  
  
@@ -1196,16 +1198,19 @@
 /**
  * Record CRCs for unresolved symbols
  **/
-static void add_versions(struct buffer *b, struct module *mod)
+static int add_versions(struct buffer *b, struct module *mod)
 {
 	struct symbol *s, *exp;
+	int err = 0;
  
 	for (s = mod->unres; s; s = s->next) {
 		exp = find_symbol(s->name);
 		if (!exp || exp->module == mod) {
-			if (have_vmlinux && !s->weak)
+			if (have_vmlinux && !s->weak) {
 				warn("\"%s\" [%s.ko] undefined!\n",
 				     s->name, mod->name);
+				err = warn_unresolved ? 0 : 1;
+			}
 			continue;
 		}
 		s->module = exp->module;
@@ -1214,7 +1219,7 @@
 	}
  
 	if (!modversions)
-		return;
+		return err;
  
 	buf_printf(b, "\n");
 	buf_printf(b, "static const struct modversion_info ____versions[]\n");
@@ -1234,6 +1239,8 @@
 	}
  
 	buf_printf(b, "};\n");
+
+	return err;
 }
  
 static void add_depends(struct buffer *b, struct module *mod,
  
@@ -1411,8 +1418,9 @@
 	char *kernel_read = NULL, *module_read = NULL;
 	char *dump_write = NULL;
 	int opt;
+	int err;
  
-	while ((opt = getopt(argc, argv, "i:I:mo:a")) != -1) {
+	while ((opt = getopt(argc, argv, "i:I:mo:aw")) != -1) {
 		switch(opt) {
 			case 'i':
 				kernel_read = optarg;
@@ -1430,6 +1438,9 @@
 			case 'a':
 				all_versions = 1;
 				break;
+			case 'w':
+				warn_unresolved = 1;
+				break;
 			default:
 				exit(1);
 		}
@@ -1450,6 +1461,8 @@
 		check_exports(mod);
 	}
  
+	err = 0;
+
 	for (mod = modules; mod; mod = mod->next) {
 		if (mod->skip)
 			continue;
@@ -1457,7 +1470,7 @@
 		buf.pos = 0;
  
 		add_header(&buf, mod);
-		add_versions(&buf, mod);
+		err |= add_versions(&buf, mod);
 		add_depends(&buf, mod, modules);
 		add_moddevtable(&buf, mod);
 		add_srcversion(&buf, mod);
@@ -1469,6 +1482,6 @@
 	if (dump_write)
 		write_dump(dump_write);
  
-	return 0;
+	return err;
 }
...	...	@@ -58,6 +58,7 @@
58	58	$(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile) \
59	59	$(if $(KBUILD_EXTMOD),-I $(modulesymfile)) \
60	60	$(if $(KBUILD_EXTMOD),-o $(modulesymfile)) \
	61	+ $(if $(KBUILD_EXTMOD),-w) \
61	62	$(wildcard vmlinux) $(filter-out FORCE,$^)
62	63
63	64	PHONY += __modpost
...	...	@@ -23,6 +23,8 @@
23	23	static int all_versions = 0;
24	24	/* If we are modposting external module set to 1 */
25	25	static int external_module = 0;
	26	+/* Only warn about unresolved symbols */
	27	+static int warn_unresolved = 0;
26	28	/* How a symbol is exported */
27	29	enum export {
28	30	export_plain, export_unused, export_gpl,
29	31
30	32
31	33
...	...	@@ -1196,16 +1198,19 @@
1196	1198	/**
1197	1199	* Record CRCs for unresolved symbols
1198	1200	**/
1199		-static void add_versions(struct buffer b, struct module mod)
	1201	+static int add_versions(struct buffer b, struct module mod)
1200	1202	{
1201	1203	struct symbol s, exp;
	1204	+ int err = 0;
1202	1205
1203	1206	for (s = mod->unres; s; s = s->next) {
1204	1207	exp = find_symbol(s->name);
1205	1208	if (!exp \|\| exp->module == mod) {
1206		- if (have_vmlinux && !s->weak)
	1209	+ if (have_vmlinux && !s->weak) {
1207	1210	warn("\"%s\" [%s.ko] undefined!\n",
1208	1211	s->name, mod->name);
	1212	+ err = warn_unresolved ? 0 : 1;
	1213	+ }
1209	1214	continue;
1210	1215	}
1211	1216	s->module = exp->module;
...	...	@@ -1214,7 +1219,7 @@
1214	1219	}
1215	1220
1216	1221	if (!modversions)
1217		- return;
	1222	+ return err;
1218	1223
1219	1224	buf_printf(b, "\n");
1220	1225	buf_printf(b, "static const struct modversion_info ____versions[]\n");
...	...	@@ -1234,6 +1239,8 @@
1234	1239	}
1235	1240
1236	1241	buf_printf(b, "};\n");
	1242	+
	1243	+ return err;
1237	1244	}
1238	1245
1239	1246	static void add_depends(struct buffer b, struct module mod,
1240	1247
...	...	@@ -1411,8 +1418,9 @@
1411	1418	char kernel_read = NULL, module_read = NULL;
1412	1419	char *dump_write = NULL;
1413	1420	int opt;
	1421	+ int err;
1414	1422
1415		- while ((opt = getopt(argc, argv, "i:I:mo:a")) != -1) {
	1423	+ while ((opt = getopt(argc, argv, "i:I:mo:aw")) != -1) {
1416	1424	switch(opt) {
1417	1425	case 'i':
1418	1426	kernel_read = optarg;
...	...	@@ -1430,6 +1438,9 @@
1430	1438	case 'a':
1431	1439	all_versions = 1;
1432	1440	break;
	1441	+ case 'w':
	1442	+ warn_unresolved = 1;
	1443	+ break;
1433	1444	default:
1434	1445	exit(1);
1435	1446	}
...	...	@@ -1450,6 +1461,8 @@
1450	1461	check_exports(mod);
1451	1462	}
1452	1463
	1464	+ err = 0;
	1465	+
1453	1466	for (mod = modules; mod; mod = mod->next) {
1454	1467	if (mod->skip)
1455	1468	continue;
...	...	@@ -1457,7 +1470,7 @@
1457	1470	buf.pos = 0;
1458	1471
1459	1472	add_header(&buf, mod);
1460		- add_versions(&buf, mod);
	1473	+ err \|= add_versions(&buf, mod);
1461	1474	add_depends(&buf, mod, modules);
1462	1475	add_moddevtable(&buf, mod);
1463	1476	add_srcversion(&buf, mod);
...	...	@@ -1469,6 +1482,6 @@
1469	1482	if (dump_write)
1470	1483	write_dump(dump_write);
1471	1484
1472		- return 0;
	1485	+ return err;
1473	1486	}