On Thu, 21 Sept 2023 at 09:41, '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/
> ---
> v2:
> - Add the memory leak backtrace.
> - Remove the unused func kfree_at_end() kernel test robot noticed.
We have some plans to reintroduce a similar function later as a
general kunit feature, but it's fine removing it here.
> - Update the commit message.
> ---
This mostly looks good, but as Rae pointed out, the cleanup won't get
called if some of the assertions fail.
Using something more like kfree_at_end(), such as
kunit_add_action(test, (kunit_action_t *)kunit_free_suite_set, got)
would resolve all of these issues.
(You may need to write a wrapper around kunit_free_suite_set to make
it work as an action if you go down that path.)
Cheers,
-- David
> 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 (!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)
Because of the KUNIT_ASSERT_EQ(test, err, 0) call above, we know err
is nonzero here, so this conditional shouldn't be required. But it
also wouldn't be if you used a deferred action to clean up.
> + kunit_free_suite_set(got);
> }
>
> 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);
> }
>
> 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);
> }
>
> 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);
> }
>
> 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);
> }
>
> 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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