[PATCH v1] kunit: add support for kunit_suites that reference init code

[Brendan Higgins <brendanhiggins@google.com>]

Add support for a new kind of kunit_suite registration macro called
kunit_test_init_suite(); this new registration macro allows the
registration of kunit_suites that reference functions marked __init and
data marked __initdata.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Martin Fernandez <martin.fernandez@eclypsium.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Gow <davidgow@google.com>
---

This is a follow-up to the RFC here[1].

This patch is in response to a KUnit user issue[2] in which the user was
attempting to test some init functions; although this is a functional
solution as long as KUnit tests only run during the init phase, we will
need to do more work if we ever allow tests to run after the init phase
is over; it is for this reason that this patch adds a new registration
macro rather than simply modifying the existing macros.

Changes since last version:
 - I added more to the kunit_test_init_suites() kernel-doc comment
   detailing "how" the modpost warnings are suppressed in addition to
   the existing information regarding "why" it is OK for the modpost
   warnings to be suppressed.

[1] https://lore.kernel.org/linux-kselftest/20220310210210.2124637-1-brendanhiggins@google.com/
[2] https://groups.google.com/g/kunit-dev/c/XDjieRHEneg/m/D0rFCwVABgAJ

---
 include/kunit/test.h | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/include/kunit/test.h b/include/kunit/test.h
index b26400731c02..7f303a06bc97 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -379,6 +379,32 @@ static inline int kunit_run_all_tests(void)
 
 #define kunit_test_suite(suite)	kunit_test_suites(&suite)
 
+/**
+ * kunit_test_init_suites() - used to register one or more &struct kunit_suite
+ *			      containing init functions or init data.
+ *
+ * @__suites: a statically allocated list of &struct kunit_suite.
+ *
+ * This functions identically as &kunit_test_suites() except that it suppresses
+ * modpost warnings for referencing functions marked __init or data marked
+ * __initdata; this is OK because currently KUnit only runs tests upon boot
+ * during the init phase or upon loading a module during the init phase.
+ *
+ * NOTE TO KUNIT DEVS: If we ever allow KUnit tests to be run after boot, these
+ * tests must be excluded.
+ *
+ * The only thing this macro does that's different from kunit_test_suites is
+ * that it suffixes the array and suite declarations it makes with _probe;
+ * modpost suppresses warnings about referencing init data for symbols named in
+ * this manner.
+ */
+#define kunit_test_init_suites(__suites...)				\
+	__kunit_test_suites(CONCATENATE(__UNIQUE_ID(array), _probe),	\
+			    CONCATENATE(__UNIQUE_ID(suites), _probe),	\
+			    ##__suites)
+
+#define kunit_test_init_suite(suite)	kunit_test_init_suites(&suite)
+
 #define kunit_suite_for_each_test_case(suite, test_case)		\
 	for (test_case = suite->test_cases; test_case->run_case; test_case++)
 

base-commit: 330f4c53d3c2d8b11d86ec03a964b86dc81452f5
-- 
2.35.1.723.g4982287a31-goog