[PATCH v3 2/5] fortify: Allow KUnit test to build without FORTIFY

[Kees Cook]

In order for CI systems to notice all the skipped tests related to
CONFIG_FORTIFY_SOURCE, allow the FORTIFY_SOURCE KUnit tests to build
with or without CONFIG_FORTIFY_SOURCE.

Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
Cc: linux-hardening@xxxxxxxxxxxxxxx
---
 lib/Kconfig.debug   |  2 +-
 lib/fortify_kunit.c | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 975a07f9f1cc..4e2febe3b568 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2748,7 +2748,7 @@ config STACKINIT_KUNIT_TEST
 
 config FORTIFY_KUNIT_TEST
 	tristate "Test fortified str*() and mem*() function internals at runtime" if !KUNIT_ALL_TESTS
-	depends on KUNIT && FORTIFY_SOURCE
+	depends on KUNIT
 	default KUNIT_ALL_TESTS
 	help
 	  Builds unit tests for checking internals of FORTIFY_SOURCE as used
diff --git a/lib/fortify_kunit.c b/lib/fortify_kunit.c
index 2e4fedc81621..7a88b5dd3d27 100644
--- a/lib/fortify_kunit.c
+++ b/lib/fortify_kunit.c
@@ -22,6 +22,11 @@
 #include <linux/string.h>
 #include <linux/vmalloc.h>
 
+/* Handle being built without CONFIG_FORTIFY_SOURCE */
+#ifndef __compiletime_strlen
+# define __compiletime_strlen __builtin_strlen
+#endif
+
 static const char array_of_10[] = "this is 10";
 static const char *ptr_of_11 = "this is 11!";
 static char array_unknown[] = "compiler thinks I might change";
@@ -308,6 +313,14 @@ DEFINE_ALLOC_SIZE_TEST_PAIR(kvmalloc)
 } while (0)
 DEFINE_ALLOC_SIZE_TEST_PAIR(devm_kmalloc)
 
+static int fortify_test_init(struct kunit *test)
+{
+	if (!IS_ENABLED(CONFIG_FORTIFY_SOURCE))
+		kunit_skip(test, "Not built with CONFIG_FORTIFY_SOURCE=y");
+
+	return 0;
+}
+
 static struct kunit_case fortify_test_cases[] = {
 	KUNIT_CASE(known_sizes_test),
 	KUNIT_CASE(control_flow_split_test),
@@ -324,6 +337,7 @@ static struct kunit_case fortify_test_cases[] = {
 
 static struct kunit_suite fortify_test_suite = {
 	.name = "fortify",
+	.init = fortify_test_init,
 	.test_cases = fortify_test_cases,
 };
 
-- 
2.34.1