Hi Jinjie,
On Mon, 18 Sep 2023 15:47:59 +0800 Jinjie Ruan <ruanjinjie@xxxxxxxxxx> wrote:
> When CONFIG_DAMON_KUNIT_TEST=y and making CONFIG_DEBUG_KMEMLEAK=y
> and CONFIG_DEBUG_KMEMLEAK_AUTO_SCAN=y, the below memory leak is detected.
>
> The damon_ctx which is allocated by kzalloc() in damon_new_ctx() in
> damon_test_ops_registration() and damon_test_set_attrs() are not freed.
> So use damon_destroy_ctx() to free it. After applying this patch, the
> following memory leak is never detected
>
> unreferenced object 0xffff2b49c6968800 (size 512):
> comm "kunit_try_catch", pid 350, jiffies 4294895294 (age 557.028s)
> hex dump (first 32 bytes):
> 88 13 00 00 00 00 00 00 a0 86 01 00 00 00 00 00 ................
> 00 87 93 03 00 00 00 00 0a 00 00 00 00 00 00 00 ................
> backtrace:
> [<0000000088e71769>] slab_post_alloc_hook+0xb8/0x368
> [<0000000073acab3b>] __kmem_cache_alloc_node+0x174/0x290
> [<00000000b5f89cef>] kmalloc_trace+0x40/0x164
> [<00000000eb19e83f>] damon_new_ctx+0x28/0xb4
> [<00000000daf6227b>] damon_test_ops_registration+0x34/0x328
> [<00000000559c4801>] kunit_try_run_case+0x50/0xac
> [<000000003932ed49>] kunit_generic_run_threadfn_adapter+0x20/0x2c
> [<000000003c3e9211>] kthread+0x124/0x130
> [<0000000028f85bdd>] ret_from_fork+0x10/0x20
> unreferenced object 0xffff2b49c1a9cc00 (size 512):
> comm "kunit_try_catch", pid 356, jiffies 4294895306 (age 557.000s)
> hex dump (first 32 bytes):
> 88 13 00 00 00 00 00 00 a0 86 01 00 00 00 00 00 ................
> 00 00 00 00 00 00 00 00 0a 00 00 00 00 00 00 00 ................
> backtrace:
> [<0000000088e71769>] slab_post_alloc_hook+0xb8/0x368
> [<0000000073acab3b>] __kmem_cache_alloc_node+0x174/0x290
> [<00000000b5f89cef>] kmalloc_trace+0x40/0x164
> [<00000000eb19e83f>] damon_new_ctx+0x28/0xb4
> [<00000000058495c4>] damon_test_set_attrs+0x30/0x1a8
> [<00000000559c4801>] kunit_try_run_case+0x50/0xac
> [<000000003932ed49>] kunit_generic_run_threadfn_adapter+0x20/0x2c
> [<000000003c3e9211>] kthread+0x124/0x130
> [<0000000028f85bdd>] ret_from_fork+0x10/0x20
>
> Fixes: d1836a3b2a9a ("mm/damon/core-test: initialise context before test in damon_test_set_attrs()")
> Fixes: 4f540f5ab4f2 ("mm/damon/core-test: add a kunit test case for ops registration")
> Signed-off-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
> Reviewed-by: Feng Tang <feng.tang@xxxxxxxxx>
Reviewed-by: SeongJae Park <sj@xxxxxxxxxx>
Thanks,
SJ
> ---
> v2:
> - Add Reviewed-by.
> - Rebased on mm-unstable.
> - Update the commit message.
> ---
> mm/damon/core-test.h | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/mm/damon/core-test.h b/mm/damon/core-test.h
> index 3959be35b901..649adf91ebc5 100644
> --- a/mm/damon/core-test.h
> +++ b/mm/damon/core-test.h
> @@ -269,6 +269,8 @@ static void damon_test_ops_registration(struct kunit *test)
>
> /* Check double-registration failure again */
> KUNIT_EXPECT_EQ(test, damon_register_ops(&ops), -EINVAL);
> +
> + damon_destroy_ctx(c);
> }
>
> static void damon_test_set_regions(struct kunit *test)
> @@ -346,6 +348,8 @@ static void damon_test_set_attrs(struct kunit *test)
> invalid_attrs = valid_attrs;
> invalid_attrs.aggr_interval = 4999;
> KUNIT_EXPECT_EQ(test, damon_set_attrs(c, &invalid_attrs), -EINVAL);
> +
> + damon_destroy_ctx(c);
> }
>
> static void damon_test_moving_sum(struct kunit *test)
> --
> 2.34.1
>
>
