On 2023/9/22 3:50, Rae Moar wrote:
> On Wed, Sep 20, 2023 at 9:41 PM 'Jinjie Ruan' via KUnit Development
> <kunit-dev@xxxxxxxxxxxxxxxx> wrote:
>>
>> When CONFIG_KUNIT_ALL_TESTS=y, making CONFIG_DEBUG_KMEMLEAK=y and
>> CONFIG_DEBUG_KMEMLEAK_AUTO_SCAN=y, the below memory leak is detected.
>>
>> If kunit_filter_suites() succeeds, not only copy but also filtered_suite
>> and filtered_suite->test_cases should be freed.
>>
>> So use kunit_free_suite_set() to free the filtered_suite,
>> filtered_suite->test_cases and copy as kunit_module_exit() and
>> kunit_run_all_tests() do it. And the func kfree_at_end() is not used so
>> remove it. After applying this patch, the following memory leak is never
>> detected.
>>
>> unreferenced object 0xffff8881001de400 (size 1024):
>> comm "kunit_try_catch", pid 1396, jiffies 4294720452 (age 932.801s)
>> hex dump (first 32 bytes):
>> 73 75 69 74 65 32 00 00 00 00 00 00 00 00 00 00 suite2..........
>> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
>> backtrace:
>> [<ffffffff817db753>] __kmalloc_node_track_caller+0x53/0x150
>> [<ffffffff817bd242>] kmemdup+0x22/0x50
>> [<ffffffff829e961d>] kunit_filter_suites+0x44d/0xcc0
>> [<ffffffff829eb69f>] filter_suites_test+0x12f/0x360
>> [<ffffffff829e802a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
>> [<ffffffff81236fc6>] kthread+0x2b6/0x380
>> [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
>> [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
>> unreferenced object 0xffff8881052cd388 (size 192):
>> comm "kunit_try_catch", pid 1396, jiffies 4294720452 (age 932.801s)
>> hex dump (first 32 bytes):
>> a0 85 9e 82 ff ff ff ff 80 cd 7c 84 ff ff ff ff ..........|.....
>> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
>> backtrace:
>> [<ffffffff817dbad2>] __kmalloc+0x52/0x150
>> [<ffffffff829e9651>] kunit_filter_suites+0x481/0xcc0
>> [<ffffffff829eb69f>] filter_suites_test+0x12f/0x360
>> [<ffffffff829e802a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
>> [<ffffffff81236fc6>] kthread+0x2b6/0x380
>> [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
>> [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
>>
>> unreferenced object 0xffff888100da8400 (size 1024):
>> comm "kunit_try_catch", pid 1398, jiffies 4294720454 (age 781.945s)
>> hex dump (first 32 bytes):
>> 73 75 69 74 65 32 00 00 00 00 00 00 00 00 00 00 suite2..........
>> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
>> backtrace:
>> [<ffffffff817db753>] __kmalloc_node_track_caller+0x53/0x150
>> [<ffffffff817bd242>] kmemdup+0x22/0x50
>> [<ffffffff829e961d>] kunit_filter_suites+0x44d/0xcc0
>> [<ffffffff829eb13f>] filter_suites_test_glob_test+0x12f/0x560
>> [<ffffffff829e802a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
>> [<ffffffff81236fc6>] kthread+0x2b6/0x380
>> [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
>> [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
>> unreferenced object 0xffff888105117878 (size 96):
>> comm "kunit_try_catch", pid 1398, jiffies 4294720454 (age 781.945s)
>> hex dump (first 32 bytes):
>> a0 85 9e 82 ff ff ff ff a0 ac 7c 84 ff ff ff ff ..........|.....
>> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
>> backtrace:
>> [<ffffffff817dbad2>] __kmalloc+0x52/0x150
>> [<ffffffff829e9651>] kunit_filter_suites+0x481/0xcc0
>> [<ffffffff829eb13f>] filter_suites_test_glob_test+0x12f/0x560
>> [<ffffffff829e802a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
>> [<ffffffff81236fc6>] kthread+0x2b6/0x380
>> [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
>> [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
>> unreferenced object 0xffff888102c31c00 (size 1024):
>> comm "kunit_try_catch", pid 1404, jiffies 4294720460 (age 781.948s)
>> hex dump (first 32 bytes):
>> 6e 6f 72 6d 61 6c 5f 73 75 69 74 65 00 00 00 00 normal_suite....
>> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
>> backtrace:
>> [<ffffffff817db753>] __kmalloc_node_track_caller+0x53/0x150
>> [<ffffffff817bd242>] kmemdup+0x22/0x50
>> [<ffffffff829ecf17>] kunit_filter_attr_tests+0xf7/0x860
>> [<ffffffff829e99ff>] kunit_filter_suites+0x82f/0xcc0
>> [<ffffffff829ea975>] filter_attr_test+0x195/0x5f0
>> [<ffffffff829e802a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
>> [<ffffffff81236fc6>] kthread+0x2b6/0x380
>> [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
>> [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
>> unreferenced object 0xffff8881052cd250 (size 192):
>> comm "kunit_try_catch", pid 1404, jiffies 4294720460 (age 781.948s)
>> hex dump (first 32 bytes):
>> a0 85 9e 82 ff ff ff ff 00 a9 7c 84 ff ff ff ff ..........|.....
>> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
>> backtrace:
>> [<ffffffff817dbad2>] __kmalloc+0x52/0x150
>> [<ffffffff829ecfc1>] kunit_filter_attr_tests+0x1a1/0x860
>> [<ffffffff829e99ff>] kunit_filter_suites+0x82f/0xcc0
>> [<ffffffff829ea975>] filter_attr_test+0x195/0x5f0
>> [<ffffffff829e802a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
>> [<ffffffff81236fc6>] kthread+0x2b6/0x380
>> [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
>> [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
>> unreferenced object 0xffff888104f4e400 (size 1024):
>> comm "kunit_try_catch", pid 1408, jiffies 4294720464 (age 781.944s)
>> hex dump (first 32 bytes):
>> 73 75 69 74 65 00 00 00 00 00 00 00 00 00 00 00 suite...........
>> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
>> backtrace:
>> [<ffffffff817db753>] __kmalloc_node_track_caller+0x53/0x150
>> [<ffffffff817bd242>] kmemdup+0x22/0x50
>> [<ffffffff829ecf17>] kunit_filter_attr_tests+0xf7/0x860
>> [<ffffffff829e99ff>] kunit_filter_suites+0x82f/0xcc0
>> [<ffffffff829e9fc3>] filter_attr_skip_test+0x133/0x6e0
>> [<ffffffff829e802a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
>> [<ffffffff81236fc6>] kthread+0x2b6/0x380
>> [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
>> [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
>> unreferenced object 0xffff8881052cc620 (size 192):
>> comm "kunit_try_catch", pid 1408, jiffies 4294720464 (age 781.944s)
>> hex dump (first 32 bytes):
>> a0 85 9e 82 ff ff ff ff c0 a8 7c 84 ff ff ff ff ..........|.....
>> 00 00 00 00 00 00 00 00 02 00 00 00 02 00 00 00 ................
>> backtrace:
>> [<ffffffff817dbad2>] __kmalloc+0x52/0x150
>> [<ffffffff829ecfc1>] kunit_filter_attr_tests+0x1a1/0x860
>> [<ffffffff829e99ff>] kunit_filter_suites+0x82f/0xcc0
>> [<ffffffff829e9fc3>] filter_attr_skip_test+0x133/0x6e0
>> [<ffffffff829e802a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
>> [<ffffffff81236fc6>] kthread+0x2b6/0x380
>> [<ffffffff81096afd>] ret_from_fork+0x2d/0x70
>> [<ffffffff81003511>] ret_from_fork_asm+0x11/0x20
>>
>> Fixes: e5857d396f35 ("kunit: flatten kunit_suite*** to kunit_suite** in .kunit_test_suites")
>> Signed-off-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
>> Reported-by: kernel test robot <lkp@xxxxxxxxx>
>> Closes: https://lore.kernel.org/oe-kbuild-all/202309142251.uJ8saAZv-lkp@xxxxxxxxx/
>
> Hello!
>
> Thanks for sending out a new version and responding to my comments. I
> do have one issue below.
>
> Thanks!
> -Rae
>
>> ---
>> v2:
>> - Add the memory leak backtrace.
>> - Remove the unused func kfree_at_end() kernel test robot noticed.
>> - Update the commit message.
>> ---
>> lib/kunit/executor_test.c | 40 ++++++++++++++++++---------------------
>> 1 file changed, 18 insertions(+), 22 deletions(-)
>>
>> diff --git a/lib/kunit/executor_test.c b/lib/kunit/executor_test.c
>> index b4f6f96b2844..88d26c9cdce8 100644
>> --- a/lib/kunit/executor_test.c
>> +++ b/lib/kunit/executor_test.c
>> @@ -9,7 +9,6 @@
>> #include <kunit/test.h>
>> #include <kunit/attributes.h>
>>
>> -static void kfree_at_end(struct kunit *test, const void *to_free);
>> static struct kunit_suite *alloc_fake_suite(struct kunit *test,
>> const char *suite_name,
>> struct kunit_case *test_cases);
>> @@ -56,7 +55,6 @@ static void filter_suites_test(struct kunit *test)
>> got = kunit_filter_suites(&suite_set, "suite2", NULL, NULL, &err);
>> KUNIT_ASSERT_NOT_ERR_OR_NULL(test, got.start);
>> KUNIT_ASSERT_EQ(test, err, 0);
>> - kfree_at_end(test, got.start);
>>
>> /* Validate we just have suite2 */
>> KUNIT_ASSERT_NOT_ERR_OR_NULL(test, got.start[0]);
>> @@ -64,6 +62,9 @@ static void filter_suites_test(struct kunit *test)
>>
>> /* Contains one element (end is 1 past end) */
>> KUNIT_ASSERT_EQ(test, got.end - got.start, 1);
>
> If filtering incorrectly outputs more than one suite, the line above
> will fail. This will cause the test to exit immediately because this
> is an ASSERT statement instead of an EXPECT statement.
>
> If this happens, the suite set will never be freed. Instead we should
> change this to KUNIT_EXPECT_EQ so the test will continue to the below
> if statement.
>
> We should change this for all similar lines where we still want to
> free the suite if they fail.
Right! It is better to update the kfree_at_end() func to solve these
problems. I'll try to do it sooner.
>
>> +
>> + if (!err)
>> + kunit_free_suite_set(got);
>
>> }
>>
>> static void filter_suites_test_glob_test(struct kunit *test)
>> @@ -82,7 +83,6 @@ static void filter_suites_test_glob_test(struct kunit *test)
>> got = kunit_filter_suites(&suite_set, "suite2.test2", NULL, NULL, &err);
>> KUNIT_ASSERT_NOT_ERR_OR_NULL(test, got.start);
>> KUNIT_ASSERT_EQ(test, err, 0);
>> - kfree_at_end(test, got.start);
>>
>> /* Validate we just have suite2 */
>> KUNIT_ASSERT_NOT_ERR_OR_NULL(test, got.start[0]);
>> @@ -93,6 +93,9 @@ static void filter_suites_test_glob_test(struct kunit *test)
>> KUNIT_ASSERT_NOT_ERR_OR_NULL(test, got.start[0]->test_cases);
>> KUNIT_EXPECT_STREQ(test, (const char *)got.start[0]->test_cases[0].name, "test2");
>> KUNIT_EXPECT_FALSE(test, got.start[0]->test_cases[1].name);
>> +
>> + if (!err)
>> + kunit_free_suite_set(got);
>
> Again I recommend changing the line in this test from
> "KUNIT_ASSERT_EQ(test, got.end - got.start, 1);" to an EXPECT
> statement.
>
>> }
>>
>> static void filter_suites_to_empty_test(struct kunit *test)
>> @@ -109,10 +112,12 @@ static void filter_suites_to_empty_test(struct kunit *test)
>>
>> got = kunit_filter_suites(&suite_set, "not_found", NULL, NULL, &err);
>> KUNIT_ASSERT_EQ(test, err, 0);
>> - kfree_at_end(test, got.start); /* just in case */
>>
>> KUNIT_EXPECT_PTR_EQ_MSG(test, got.start, got.end,
>> "should be empty to indicate no match");
>> +
>> + if (!err)
>> + kunit_free_suite_set(got);
>
> This test seems good.
>
>> }
>>
>> static void parse_filter_attr_test(struct kunit *test)
>> @@ -172,7 +177,6 @@ static void filter_attr_test(struct kunit *test)
>> got = kunit_filter_suites(&suite_set, NULL, filter, NULL, &err);
>> KUNIT_ASSERT_NOT_ERR_OR_NULL(test, got.start);
>> KUNIT_ASSERT_EQ(test, err, 0);
>> - kfree_at_end(test, got.start);
>>
>> /* Validate we just have normal_suite */
>> KUNIT_ASSERT_NOT_ERR_OR_NULL(test, got.start[0]);
>> @@ -183,6 +187,9 @@ static void filter_attr_test(struct kunit *test)
>> KUNIT_ASSERT_NOT_ERR_OR_NULL(test, got.start[0]->test_cases);
>> KUNIT_EXPECT_STREQ(test, got.start[0]->test_cases[0].name, "normal");
>> KUNIT_EXPECT_FALSE(test, got.start[0]->test_cases[1].name);
>> +
>> + if (!err)
>> + kunit_free_suite_set(got);
>
> Again I recommend changing the line in this test from
> "KUNIT_ASSERT_EQ(test, got.end - got.start, 1);" to an EXPECT
> statement.
>
>> }
>>
>> static void filter_attr_empty_test(struct kunit *test)
>> @@ -200,10 +207,12 @@ static void filter_attr_empty_test(struct kunit *test)
>>
>> got = kunit_filter_suites(&suite_set, NULL, filter, NULL, &err);
>> KUNIT_ASSERT_EQ(test, err, 0);
>> - kfree_at_end(test, got.start); /* just in case */
>>
>> KUNIT_EXPECT_PTR_EQ_MSG(test, got.start, got.end,
>> "should be empty to indicate no match");
>> +
>> + if (!err)
>> + kunit_free_suite_set(got);
>
> This test seems good.
>
>> }
>>
>> static void filter_attr_skip_test(struct kunit *test)
>> @@ -222,7 +231,6 @@ static void filter_attr_skip_test(struct kunit *test)
>> got = kunit_filter_suites(&suite_set, NULL, filter, "skip", &err);
>> KUNIT_ASSERT_NOT_ERR_OR_NULL(test, got.start);
>> KUNIT_ASSERT_EQ(test, err, 0);
>> - kfree_at_end(test, got.start);
>>
>> /* Validate we have both the slow and normal test */
>> KUNIT_ASSERT_NOT_ERR_OR_NULL(test, got.start[0]->test_cases);
>> @@ -233,6 +241,9 @@ static void filter_attr_skip_test(struct kunit *test)
>> /* Now ensure slow is skipped and normal is not */
>> KUNIT_EXPECT_EQ(test, got.start[0]->test_cases[0].status, KUNIT_SKIPPED);
>> KUNIT_EXPECT_FALSE(test, got.start[0]->test_cases[1].status);
>> +
>> + if (!err)
>> + kunit_free_suite_set(got);
>
> Similarly, the line "KUNIT_ASSERT_EQ(test,
> kunit_suite_num_test_cases(got.start[0]), 2)" may exit causing the
> suite to not be freed. This should be changed to an EXPECT statement.
> However, we may then want to check before accessing the test cases.
>
>> }
>>
>> static struct kunit_case executor_test_cases[] = {
>> @@ -255,21 +266,6 @@ static struct kunit_suite executor_test_suite = {
>> kunit_test_suites(&executor_test_suite);
>>
>> /* Test helpers */
>> -
>> -/* Use the resource API to register a call to kfree(to_free).
>> - * Since we never actually use the resource, it's safe to use on const data.
>> - */
>> -static void kfree_at_end(struct kunit *test, const void *to_free)
>> -{
>> - /* kfree() handles NULL already, but avoid allocating a no-op cleanup. */
>> - if (IS_ERR_OR_NULL(to_free))
>> - return;
>> -
>> - kunit_add_action(test,
>> - (kunit_action_t *)kfree,
>> - (void *)to_free);
>> -}
>> -
>> static struct kunit_suite *alloc_fake_suite(struct kunit *test,
>> const char *suite_name,
>> struct kunit_case *test_cases)
>> --
>> 2.34.1
>>
>> --
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>
