From e047c5eaa76324575e1f95664be4c74ce0e2571b Mon Sep 17 00:00:00 2001 From: David Gow Date: Tue, 31 Jan 2023 14:46:40 +0800 Subject: kunit: Expose 'static stub' API to redirect functions Add a simple way of redirecting calls to functions by including a special prologue in the "real" function which checks to see if the replacement function should be called (and, if so, calls it). To redirect calls to a function, make the first (non-declaration) line of the function: KUNIT_STATIC_STUB_REDIRECT(function_name, [function arguments]); (This will compile away to nothing if KUnit is not enabled, otherwise it will check if a redirection is active, call the replacement function, and return. This check is protected by a static branch, so has very little overhead when there are no KUnit tests running.) Calls to the real function can be redirected to a replacement using: kunit_activate_static_stub(test, real_fn, replacement_fn); The redirection will only affect calls made from within the kthread of the current test, and will be automatically disabled when the test completes. It can also be manually disabled with kunit_deactivate_static_stub(). The 'example' KUnit test suite has a more complete example. Co-developed-by: Daniel Latypov Signed-off-by: Daniel Latypov Signed-off-by: David Gow Reviewed-by: Brendan Higgins Signed-off-by: Shuah Khan --- include/kunit/test-bug.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/kunit/test-bug.h') diff --git a/include/kunit/test-bug.h b/include/kunit/test-bug.h index 2b505a95b641..30ca541b6ff2 100644 --- a/include/kunit/test-bug.h +++ b/include/kunit/test-bug.h @@ -20,6 +20,7 @@ DECLARE_STATIC_KEY_FALSE(kunit_running); /* Hooks table: a table of function pointers filled in when kunit loads */ extern struct kunit_hooks_table { __printf(3, 4) void (*fail_current_test)(const char*, int, const char*, ...); + void *(*get_static_stub_address)(struct kunit *test, void *real_fn_addr); } kunit_hooks; /** -- cgit v1.2.3