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From:   Marco Pagani <marpagan@redhat.com>
To:     Brendan Higgins <brendan.higgins@linux.dev>,
        David Gow <davidgow@google.com>, Rae Moar <rmoar@google.com>,
        Shuah Khan <skhan@linuxfoundation.org>,
        Jinjie Ruan <ruanjinjie@huawei.com>
Cc:     Marco Pagani <marpagan@redhat.com>,
        linux-kselftest@vger.kernel.org, kunit-dev@googlegroups.com,
        linux-kernel@vger.kernel.org
Subject: [PATCH] kunit: run test suites only after module initialization completes
Date:   Mon, 16 Oct 2023 22:35:47 +0200
Message-ID: <20231016203548.21993-1-marpagan@redhat.com>
MIME-Version: 1.0
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Precedence: bulk

Commit 2810c1e99867 ("kunit: Fix wild-memory-access bug in
kunit_free_suite_set()") is causing all test suites to run (when
built as modules) while still in MODULE_STATE_COMING. In that state,
test modules are not fully initialized and lack sysfs kobjects.
This behavior can cause a crash if the test module tries to register
fake devices.

This patch restores the normal execution flow, waiting for the module
initialization to complete before running the test suites.
The issue reported in the commit mentioned above is addressed using
virt_addr_valid() to detect if the module loading has failed
and mod->kunit_suites has not been allocated using kmalloc_array().

Fixes: 2810c1e99867 ("kunit: Fix wild-memory-access bug in kunit_free_suite_set()")
Signed-off-by: Marco Pagani <marpagan@redhat.com>
---
 lib/kunit/test.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index 421f13981412..1a49569186fc 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -769,12 +769,14 @@ static void kunit_module_exit(struct module *mod)
 	};
 	const char *action = kunit_action();
 
+	if (!suite_set.start || !virt_addr_valid(suite_set.start))
+		return;
+
 	if (!action)
 		__kunit_test_suites_exit(mod->kunit_suites,
 					 mod->num_kunit_suites);
 
-	if (suite_set.start)
-		kunit_free_suite_set(suite_set);
+	kunit_free_suite_set(suite_set);
 }
 
 static int kunit_module_notify(struct notifier_block *nb, unsigned long val,
@@ -784,12 +786,12 @@ static int kunit_module_notify(struct notifier_block *nb, unsigned long val,
 
 	switch (val) {
 	case MODULE_STATE_LIVE:
+		kunit_module_init(mod);
 		break;
 	case MODULE_STATE_GOING:
 		kunit_module_exit(mod);
 		break;
 	case MODULE_STATE_COMING:
-		kunit_module_init(mod);
 		break;
 	case MODULE_STATE_UNFORMED:
 		break;
-- 
2.41.0