[PATCH] Revert "fortify: Allow KUnit test to build without FORTIFY"

[Kees Cook]

This reverts commit a9dc8d0442294b426b1ebd4ec6097c82ebe282e0.

The standard for KUnit is to not build tests at all when required
functionality is missing, rather than doing test "skip". Restore this
for the fortify tests, so that architectures without
CONFIG_ARCH_HAS_FORTIFY_SOURCE do not emit unsolvable warnings.

Reported-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Closes: https://lore.kernel.org/all/CAMuHMdUrxOEroHVUt7-mAnKSBjY=a-D3jr+XiAifuwv06Ob9Pw@xxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
I'll take this via my hardening tree and send a PR to Linus before -rc1.
---
 lib/Kconfig.debug   |  2 +-
 lib/fortify_kunit.c | 14 --------------
 2 files changed, 1 insertion(+), 15 deletions(-)

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index c2a7608ff585..6c6a7ee9f1f9 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2645,7 +2645,7 @@ 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
+	depends on KUNIT && FORTIFY_SOURCE
 	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 524132f33cf0..c8c33cbaae9e 100644
--- a/lib/fortify_kunit.c
+++ b/lib/fortify_kunit.c
@@ -25,11 +25,6 @@ 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";
 
-/* Handle being built without CONFIG_FORTIFY_SOURCE */
-#ifndef __compiletime_strlen
-# define __compiletime_strlen __builtin_strlen
-#endif
-
 static void known_sizes_test(struct kunit *test)
 {
 	KUNIT_EXPECT_EQ(test, __compiletime_strlen("88888888"), 8);
@@ -312,14 +307,6 @@ 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),
@@ -336,7 +323,6 @@ 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