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From:   Jinjie Ruan <ruanjinjie@huawei.com>
To:     <sj@kernel.org>, <akpm@linux-foundation.org>,
        <brendan.higgins@linux.dev>, <feng.tang@intel.com>,
        <damon@lists.linux.dev>, <linux-mm@kvack.org>,
        <kunit-dev@googlegroups.com>, <linux-kselftest@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
CC:     <ruanjinjie@huawei.com>
Subject: [PATCH RESEND 1/2] mm/damon/core-test: Fix memory leak in damon_new_region()
Date:   Mon, 18 Sep 2023 13:10:43 +0800
Message-ID: <20230918051044.3814018-2-ruanjinjie@huawei.com>
In-Reply-To: <20230918051044.3814018-1-ruanjinjie@huawei.com>
References: <20230918051044.3814018-1-ruanjinjie@huawei.com>
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Precedence: bulk

The damon_region which is allocated by kmem_cache_alloc() in
damon_new_region() in damon_test_regions() and
damon_test_update_monitoring_result() are not freed and it causes below
memory leak. So use damon_free_region() to free it.

unreferenced object 0xffff2b49c3edc000 (size 56):
  comm "kunit_try_catch", pid 338, jiffies 4294895280 (age 557.084s)
  hex dump (first 32 bytes):
    01 00 00 00 00 00 00 00 02 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 49 2b ff ff  ............I+..
  backtrace:
    [<0000000088e71769>] slab_post_alloc_hook+0xb8/0x368
    [<00000000b528f67c>] kmem_cache_alloc+0x168/0x284
    [<000000008603f022>] damon_new_region+0x28/0x54
    [<00000000a3b8c64e>] damon_test_regions+0x38/0x270
    [<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 0xffff2b49c5b20000 (size 56):
  comm "kunit_try_catch", pid 354, jiffies 4294895304 (age 556.988s)
  hex dump (first 32 bytes):
    03 00 00 00 00 00 00 00 07 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 96 00 00 00 49 2b ff ff  ............I+..
  backtrace:
    [<0000000088e71769>] slab_post_alloc_hook+0xb8/0x368
    [<00000000b528f67c>] kmem_cache_alloc+0x168/0x284
    [<000000008603f022>] damon_new_region+0x28/0x54
    [<00000000ca019f80>] damon_test_update_monitoring_result+0x18/0x34
    [<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: 17ccae8bb5c9 ("mm/damon: add kunit tests")
Fixes: f4c978b6594b ("mm/damon/core-test: add a test for damon_update_monitoring_results()")
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
 mm/damon/core-test.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/mm/damon/core-test.h b/mm/damon/core-test.h
index 6cc8b245586d..255f8c925c00 100644
--- a/mm/damon/core-test.h
+++ b/mm/damon/core-test.h
@@ -34,6 +34,7 @@ static void damon_test_regions(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, 0u, damon_nr_regions(t));
 
 	damon_free_target(t);
+	damon_free_region(r);
 }
 
 static unsigned int nr_damon_targets(struct damon_ctx *ctx)
@@ -316,6 +317,8 @@ static void damon_test_update_monitoring_result(struct kunit *test)
 	damon_update_monitoring_result(r, &old_attrs, &new_attrs);
 	KUNIT_EXPECT_EQ(test, r->nr_accesses, 150);
 	KUNIT_EXPECT_EQ(test, r->age, 20);
+
+	damon_free_region(r);
 }
 
 static void damon_test_set_attrs(struct kunit *test)
-- 
2.34.1