[PATCH] kunit: Move kunit_abort() call out of kunit_do_failed_assertion()

[David Gow]

KUnit aborts the current thread when an assertion fails. Currently, this
is done conditionally as part of the kunit_do_failed_assertion()
function, but this hides the kunit_abort() call from the compiler
(particularly if it's in another module). This, in turn, can lead to
both suboptimal code generation (the compiler can't know if
kunit_do_failed_assertion() will return), and to static analysis tools
like smatch giving false positives.

Moving the kunit_abort() call into the macro should give the compiler
and tools a better chance at understanding what's going on. Doing so
requires exporting kunit_abort(), though it's recommended to continue to
use assertions in lieu of aborting directly.

In addition, kunit_abort() and kunit_do_failed_assertion() are renamed
to make it clear they they're intended for internal KUnit use, to:
__kunit_do_failed_assertion() and __kunit_abort()

Suggested-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: David Gow <davidgow@xxxxxxxxxx>
---

Changes since RFCv1:
https://lore.kernel.org/linux-kselftest/20230526075355.586335-1-davidgow@xxxxxxxxxx/
- Add missing MODULE_EXPORT_GPL() (Thanks kernel test robot)
- Rename kunit_abort() and kunit_do_failed_assertion() to make it clear
  they're intended for internal use.
  - Thanks Daniel Latypov!

---
 include/kunit/test.h | 20 ++++++++++++--------
 lib/kunit/test.c     | 10 ++++------
 2 files changed, 16 insertions(+), 14 deletions(-)

diff --git a/include/kunit/test.h b/include/kunit/test.h
index 2f23d6efa505..f40e65adfb1f 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -481,7 +481,9 @@ void __printf(2, 3) kunit_log_append(char *log, const char *fmt, ...);
  */
 #define KUNIT_SUCCEED(test) do {} while (0)
 
-void kunit_do_failed_assertion(struct kunit *test,
+void __noreturn __kunit_abort(struct kunit *test);
+
+void __kunit_do_failed_assertion(struct kunit *test,
 			       const struct kunit_loc *loc,
 			       enum kunit_assert_type type,
 			       const struct kunit_assert *assert,
@@ -491,13 +493,15 @@ void kunit_do_failed_assertion(struct kunit *test,
 #define _KUNIT_FAILED(test, assert_type, assert_class, assert_format, INITIALIZER, fmt, ...) do { \
 	static const struct kunit_loc __loc = KUNIT_CURRENT_LOC;	       \
 	const struct assert_class __assertion = INITIALIZER;		       \
-	kunit_do_failed_assertion(test,					       \
-				  &__loc,				       \
-				  assert_type,				       \
-				  &__assertion.assert,			       \
-				  assert_format,			       \
-				  fmt,					       \
-				  ##__VA_ARGS__);			       \
+	__kunit_do_failed_assertion(test,				       \
+				    &__loc,				       \
+				    assert_type,			       \
+				    &__assertion.assert,		       \
+				    assert_format,			       \
+				    fmt,				       \
+				    ##__VA_ARGS__);			       \
+	if (assert_type == KUNIT_ASSERTION)				       \
+		__kunit_abort(test);					       \
 } while (0)
 
 
diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index d3fb93a23ccc..e652ab0d9996 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -310,7 +310,7 @@ static void kunit_fail(struct kunit *test, const struct kunit_loc *loc,
 	string_stream_destroy(stream);
 }
 
-static void __noreturn kunit_abort(struct kunit *test)
+void __noreturn __kunit_abort(struct kunit *test)
 {
 	kunit_try_catch_throw(&test->try_catch); /* Does not return. */
 
@@ -322,8 +322,9 @@ static void __noreturn kunit_abort(struct kunit *test)
 	 */
 	WARN_ONCE(true, "Throw could not abort from test!\n");
 }
+EXPORT_SYMBOL_GPL(__kunit_abort);
 
-void kunit_do_failed_assertion(struct kunit *test,
+void __kunit_do_failed_assertion(struct kunit *test,
 			       const struct kunit_loc *loc,
 			       enum kunit_assert_type type,
 			       const struct kunit_assert *assert,
@@ -340,11 +341,8 @@ void kunit_do_failed_assertion(struct kunit *test,
 	kunit_fail(test, loc, type, assert, assert_format, &message);
 
 	va_end(args);
-
-	if (type == KUNIT_ASSERTION)
-		kunit_abort(test);
 }
-EXPORT_SYMBOL_GPL(kunit_do_failed_assertion);
+EXPORT_SYMBOL_GPL(__kunit_do_failed_assertion);
 
 void kunit_init_test(struct kunit *test, const char *name, char *log)
 {
-- 
2.41.0.rc0.172.g3f132b7071-goog