Re: [PATCH 6/9] kunit: Enable direct registration of parameter arrays to a KUnit test

[Dan Carpenter <dan.carpenter@linaro.org>]

Hi Marie,

kernel test robot noticed the following build warnings:

https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Marie-Zhussupova/kunit-Add-parent-kunit-for-parameterized-test-context/20250730-033818
base:   https://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git kunit
patch link:    https://lore.kernel.org/r/20250729193647.3410634-7-marievic%40google.com
patch subject: [PATCH 6/9] kunit: Enable direct registration of parameter arrays to a KUnit test
config: nios2-randconfig-r072-20250731 (https://download.01.org/0day-ci/archive/20250731/202507310854.pZvIcswn-lkp@intel.com/config)
compiler: nios2-linux-gcc (GCC) 8.5.0

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202507310854.pZvIcswn-lkp@intel.com/

New smatch warnings:
lib/kunit/test.c:723 kunit_run_tests() error: we previously assumed 'test_case->generate_params' could be null (see line 714)

vim +723 lib/kunit/test.c

914cc63eea6fbe Brendan Higgins     2019-09-23  681  int kunit_run_tests(struct kunit_suite *suite)
914cc63eea6fbe Brendan Higgins     2019-09-23  682  {
fadb08e7c7501e Arpitha Raghunandan 2020-11-16  683  	char param_desc[KUNIT_PARAM_DESC_SIZE];
914cc63eea6fbe Brendan Higgins     2019-09-23  684  	struct kunit_case *test_case;
acd8e8407b8fcc David Gow           2021-08-03  685  	struct kunit_result_stats suite_stats = { 0 };
acd8e8407b8fcc David Gow           2021-08-03  686  	struct kunit_result_stats total_stats = { 0 };
8631cd2cf5fbf2 Marie Zhussupova    2025-07-29  687  	const void *curr_param;
914cc63eea6fbe Brendan Higgins     2019-09-23  688  
c272612cb4a2f7 David Gow           2022-07-01  689  	/* Taint the kernel so we know we've run tests. */
c272612cb4a2f7 David Gow           2022-07-01  690  	add_taint(TAINT_TEST, LOCKDEP_STILL_OK);
c272612cb4a2f7 David Gow           2022-07-01  691  
1cdba21db2ca31 Daniel Latypov      2022-04-29  692  	if (suite->suite_init) {
1cdba21db2ca31 Daniel Latypov      2022-04-29  693  		suite->suite_init_err = suite->suite_init(suite);
1cdba21db2ca31 Daniel Latypov      2022-04-29  694  		if (suite->suite_init_err) {
1cdba21db2ca31 Daniel Latypov      2022-04-29  695  			kunit_err(suite, KUNIT_SUBTEST_INDENT
1cdba21db2ca31 Daniel Latypov      2022-04-29  696  				  "# failed to initialize (%d)", suite->suite_init_err);
1cdba21db2ca31 Daniel Latypov      2022-04-29  697  			goto suite_end;
1cdba21db2ca31 Daniel Latypov      2022-04-29  698  		}
1cdba21db2ca31 Daniel Latypov      2022-04-29  699  	}
1cdba21db2ca31 Daniel Latypov      2022-04-29  700  
cae56e1740f559 Daniel Latypov      2022-04-29  701  	kunit_print_suite_start(suite);
914cc63eea6fbe Brendan Higgins     2019-09-23  702  
fadb08e7c7501e Arpitha Raghunandan 2020-11-16  703  	kunit_suite_for_each_test_case(suite, test_case) {
fadb08e7c7501e Arpitha Raghunandan 2020-11-16  704  		struct kunit test = { .param_value = NULL, .param_index = 0 };
acd8e8407b8fcc David Gow           2021-08-03  705  		struct kunit_result_stats param_stats = { 0 };
fadb08e7c7501e Arpitha Raghunandan 2020-11-16  706  
887d85a0736ff3 Rae Moar            2023-03-08  707  		kunit_init_test(&test, test_case->name, test_case->log);
03806177fa4cbb Marie Zhussupova    2025-07-29  708  		__kunit_init_parent_test(test_case, &test);
03806177fa4cbb Marie Zhussupova    2025-07-29  709  
529534e8cba3e6 Rae Moar            2023-07-25  710  		if (test_case->status == KUNIT_SKIPPED) {
529534e8cba3e6 Rae Moar            2023-07-25  711  			/* Test marked as skip */
529534e8cba3e6 Rae Moar            2023-07-25  712  			test.status = KUNIT_SKIPPED;
529534e8cba3e6 Rae Moar            2023-07-25  713  			kunit_update_stats(&param_stats, test.status);
44c50ed8e59936 Marie Zhussupova    2025-07-29 @714  		} else if (!test_case->generate_params && !test.params_data.params) {
                                                                            ^^^^^^^^^^^^^^^^^^^^^^^^^^
Imagine ->generate_parms is NULL but test.params_data.params is
non-NULL.

37dbb4c7c7442d David Gow           2021-11-02  715  			/* Non-parameterised test. */
529534e8cba3e6 Rae Moar            2023-07-25  716  			test_case->status = KUNIT_SKIPPED;
37dbb4c7c7442d David Gow           2021-11-02  717  			kunit_run_case_catch_errors(suite, test_case, &test);
37dbb4c7c7442d David Gow           2021-11-02  718  			kunit_update_stats(&param_stats, test.status);
03806177fa4cbb Marie Zhussupova    2025-07-29  719  		} else if (test_case->status != KUNIT_FAILURE) {
fadb08e7c7501e Arpitha Raghunandan 2020-11-16  720  			/* Get initial param. */
fadb08e7c7501e Arpitha Raghunandan 2020-11-16  721  			param_desc[0] = '\0';
8631cd2cf5fbf2 Marie Zhussupova    2025-07-29  722  			/* TODO: Make generate_params try-catch */
13ee0c64bd88a3 Marie Zhussupova    2025-07-29 @723  			curr_param = test_case->generate_params(&test, NULL, param_desc);
                                                                                     ^^^^^^^^^^^^^^^^^^^^^^^^^^
Then this could crash.

I suspect that this is fine, but I bet that in the previous
condition, just testing one would probably have been sufficient
or maybe we could have change && to ||.

529534e8cba3e6 Rae Moar            2023-07-25  724  			test_case->status = KUNIT_SKIPPED;
6c738b52316c58 Rae Moar            2022-11-23  725  			kunit_log(KERN_INFO, &test, KUNIT_SUBTEST_INDENT KUNIT_SUBTEST_INDENT
6c738b52316c58 Rae Moar            2022-11-23  726  				  "KTAP version 1\n");
44b7da5fcd4c99 David Gow           2021-11-02  727  			kunit_log(KERN_INFO, &test, KUNIT_SUBTEST_INDENT KUNIT_SUBTEST_INDENT
44b7da5fcd4c99 David Gow           2021-11-02  728  				  "# Subtest: %s", test_case->name);
fadb08e7c7501e Arpitha Raghunandan 2020-11-16  729  
8631cd2cf5fbf2 Marie Zhussupova    2025-07-29  730  			while (curr_param) {

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