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From: SeongJae Park <sj@kernel.org>
To: Jinjie Ruan <ruanjinjie@huawei.com>
Cc: linux-mm@kvack.org, damon@lists.linux.dev,
	SeongJae Park <sj@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] mm/damon/vaddr-test: Fix memory leak in damon_do_test_apply_three_regions()
Date: Mon, 25 Sep 2023 16:03:29 +0000	[thread overview]
Message-ID: <20230925160329.83109-1-sj@kernel.org> (raw)
In-Reply-To: <20230925072100.3725620-1-ruanjinjie@huawei.com>

Hi Jinjie,

On Mon, 25 Sep 2023 15:20:59 +0800 Jinjie Ruan <ruanjinjie@huawei.com> wrote:

> When CONFIG_DAMON_VADDR_KUNIT_TEST=y and making CONFIG_DEBUG_KMEMLEAK=y
> and CONFIG_DEBUG_KMEMLEAK_AUTO_SCAN=y, the below memory leak is detected.
> 
> Since commit 9f86d624292c ("mm/damon/vaddr-test: remove unnecessary
> variables"), the damon_destroy_ctx() is removed, but still call
> damon_new_target() and damon_new_region(), the damon_region which is
> allocated by kmem_cache_alloc() in damon_new_region() and the damon_target
> which is allocated by kmalloc in damon_new_target() are not freed. And the
> damon_region which is allocated in damon_new_region() in
> damon_set_regions() is also not freed.
> 
> So use damon_destroy_target to free all the damon_regions and damon_target.

Thank you for finding this bug and sending this patch!

> 
>     unreferenced object 0xffff888107c9a940 (size 64):
>       comm "kunit_try_catch", pid 1069, jiffies 4294670592 (age 732.761s)
>       hex dump (first 32 bytes):
>         00 00 00 00 00 00 00 00 06 00 00 00 6b 6b 6b 6b  ............kkkk
>         60 c7 9c 07 81 88 ff ff f8 cb 9c 07 81 88 ff ff  `...............
>       backtrace:
>         [<ffffffff817e0167>] kmalloc_trace+0x27/0xa0
>         [<ffffffff819c11cf>] damon_new_target+0x3f/0x1b0
>         [<ffffffff819c7d55>] damon_do_test_apply_three_regions.constprop.0+0x95/0x3e0
>         [<ffffffff819c82be>] damon_test_apply_three_regions1+0x21e/0x260
>         [<ffffffff829fce6a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
>         [<ffffffff81237cf6>] kthread+0x2b6/0x380
>         [<ffffffff81097add>] ret_from_fork+0x2d/0x70
>         [<ffffffff81003791>] ret_from_fork_asm+0x11/0x20
>     unreferenced object 0xffff8881079cc740 (size 56):
>       comm "kunit_try_catch", pid 1069, jiffies 4294670592 (age 732.761s)
>       hex dump (first 32 bytes):
>         05 00 00 00 00 00 00 00 14 00 00 00 00 00 00 00  ................
>         6b 6b 6b 6b 6b 6b 6b 6b 00 00 00 00 6b 6b 6b 6b  kkkkkkkk....kkkk
>       backtrace:
>         [<ffffffff819bc492>] damon_new_region+0x22/0x1c0
>         [<ffffffff819c7d91>] damon_do_test_apply_three_regions.constprop.0+0xd1/0x3e0
>         [<ffffffff819c82be>] damon_test_apply_three_regions1+0x21e/0x260
>         [<ffffffff829fce6a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
>         [<ffffffff81237cf6>] kthread+0x2b6/0x380
>         [<ffffffff81097add>] ret_from_fork+0x2d/0x70
>         [<ffffffff81003791>] ret_from_fork_asm+0x11/0x20
>     unreferenced object 0xffff888107c9ac40 (size 64):
>       comm "kunit_try_catch", pid 1071, jiffies 4294670595 (age 732.843s)
>       hex dump (first 32 bytes):
>         00 00 00 00 00 00 00 00 06 00 00 00 6b 6b 6b 6b  ............kkkk
>         a0 cc 9c 07 81 88 ff ff 78 a1 76 07 81 88 ff ff  ........x.v.....
>       backtrace:
>         [<ffffffff817e0167>] kmalloc_trace+0x27/0xa0
>         [<ffffffff819c11cf>] damon_new_target+0x3f/0x1b0
>         [<ffffffff819c7d55>] damon_do_test_apply_three_regions.constprop.0+0x95/0x3e0
>         [<ffffffff819c851e>] damon_test_apply_three_regions2+0x21e/0x260
>         [<ffffffff829fce6a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
>         [<ffffffff81237cf6>] kthread+0x2b6/0x380
>         [<ffffffff81097add>] ret_from_fork+0x2d/0x70
>         [<ffffffff81003791>] ret_from_fork_asm+0x11/0x20
>     unreferenced object 0xffff8881079ccc80 (size 56):
>       comm "kunit_try_catch", pid 1071, jiffies 4294670595 (age 732.843s)
>       hex dump (first 32 bytes):
>         05 00 00 00 00 00 00 00 14 00 00 00 00 00 00 00  ................
>         6b 6b 6b 6b 6b 6b 6b 6b 00 00 00 00 6b 6b 6b 6b  kkkkkkkk....kkkk
>       backtrace:
>         [<ffffffff819bc492>] damon_new_region+0x22/0x1c0
>         [<ffffffff819c7d91>] damon_do_test_apply_three_regions.constprop.0+0xd1/0x3e0
>         [<ffffffff819c851e>] damon_test_apply_three_regions2+0x21e/0x260
>         [<ffffffff829fce6a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
>         [<ffffffff81237cf6>] kthread+0x2b6/0x380
>         [<ffffffff81097add>] ret_from_fork+0x2d/0x70
>         [<ffffffff81003791>] ret_from_fork_asm+0x11/0x20
>     unreferenced object 0xffff888107c9af40 (size 64):
>       comm "kunit_try_catch", pid 1073, jiffies 4294670597 (age 733.011s)
>       hex dump (first 32 bytes):
>         00 00 00 00 00 00 00 00 06 00 00 00 6b 6b 6b 6b  ............kkkk
>         20 a2 76 07 81 88 ff ff b8 a6 76 07 81 88 ff ff   .v.......v.....
>       backtrace:
>         [<ffffffff817e0167>] kmalloc_trace+0x27/0xa0
>         [<ffffffff819c11cf>] damon_new_target+0x3f/0x1b0
>         [<ffffffff819c7d55>] damon_do_test_apply_three_regions.constprop.0+0x95/0x3e0
>         [<ffffffff819c877e>] damon_test_apply_three_regions3+0x21e/0x260
>         [<ffffffff829fce6a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
>         [<ffffffff81237cf6>] kthread+0x2b6/0x380
>         [<ffffffff81097add>] ret_from_fork+0x2d/0x70
>         [<ffffffff81003791>] ret_from_fork_asm+0x11/0x20
>     unreferenced object 0xffff88810776a200 (size 56):
>       comm "kunit_try_catch", pid 1073, jiffies 4294670597 (age 733.011s)
>       hex dump (first 32 bytes):
>         05 00 00 00 00 00 00 00 14 00 00 00 00 00 00 00  ................
>         6b 6b 6b 6b 6b 6b 6b 6b 00 00 00 00 6b 6b 6b 6b  kkkkkkkk....kkkk
>       backtrace:
>         [<ffffffff819bc492>] damon_new_region+0x22/0x1c0
>         [<ffffffff819c7d91>] damon_do_test_apply_three_regions.constprop.0+0xd1/0x3e0
>         [<ffffffff819c877e>] damon_test_apply_three_regions3+0x21e/0x260
>         [<ffffffff829fce6a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
>         [<ffffffff81237cf6>] kthread+0x2b6/0x380
>         [<ffffffff81097add>] ret_from_fork+0x2d/0x70
>         [<ffffffff81003791>] ret_from_fork_asm+0x11/0x20
>     unreferenced object 0xffff88810776a740 (size 56):
>       comm "kunit_try_catch", pid 1073, jiffies 4294670597 (age 733.025s)
>       hex dump (first 32 bytes):
>         3d 00 00 00 00 00 00 00 3f 00 00 00 00 00 00 00  =.......?.......
>         6b 6b 6b 6b 6b 6b 6b 6b 00 00 00 00 6b 6b 6b 6b  kkkkkkkk....kkkk
>       backtrace:
>         [<ffffffff819bc492>] damon_new_region+0x22/0x1c0
>         [<ffffffff819bfcc2>] damon_set_regions+0x4c2/0x8e0
>         [<ffffffff819c7dbb>] damon_do_test_apply_three_regions.constprop.0+0xfb/0x3e0
>         [<ffffffff819c877e>] damon_test_apply_three_regions3+0x21e/0x260
>         [<ffffffff829fce6a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
>         [<ffffffff81237cf6>] kthread+0x2b6/0x380
>         [<ffffffff81097add>] ret_from_fork+0x2d/0x70
>         [<ffffffff81003791>] ret_from_fork_asm+0x11/0x20
>     unreferenced object 0xffff888108038240 (size 64):
>       comm "kunit_try_catch", pid 1075, jiffies 4294670600 (age 733.022s)
>       hex dump (first 32 bytes):
>         00 00 00 00 00 00 00 00 03 00 00 00 6b 6b 6b 6b  ............kkkk
>         48 ad 76 07 81 88 ff ff 98 ae 76 07 81 88 ff ff  H.v.......v.....
>       backtrace:
>         [<ffffffff817e0167>] kmalloc_trace+0x27/0xa0
>         [<ffffffff819c11cf>] damon_new_target+0x3f/0x1b0
>         [<ffffffff819c7d55>] damon_do_test_apply_three_regions.constprop.0+0x95/0x3e0
>         [<ffffffff819c898d>] damon_test_apply_three_regions4+0x1cd/0x210
>         [<ffffffff829fce6a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
>         [<ffffffff81237cf6>] kthread+0x2b6/0x380
>         [<ffffffff81097add>] ret_from_fork+0x2d/0x70
>         [<ffffffff81003791>] ret_from_fork_asm+0x11/0x20
>     unreferenced object 0xffff88810776ad28 (size 56):
>       comm "kunit_try_catch", pid 1075, jiffies 4294670600 (age 733.022s)
>       hex dump (first 32 bytes):
>         05 00 00 00 00 00 00 00 07 00 00 00 00 00 00 00  ................
>         6b 6b 6b 6b 6b 6b 6b 6b 00 00 00 00 6b 6b 6b 6b  kkkkkkkk....kkkk
>       backtrace:
>         [<ffffffff819bc492>] damon_new_region+0x22/0x1c0
>         [<ffffffff819bfcc2>] damon_set_regions+0x4c2/0x8e0
>         [<ffffffff819c7dbb>] damon_do_test_apply_three_regions.constprop.0+0xfb/0x3e0
>         [<ffffffff819c898d>] damon_test_apply_three_regions4+0x1cd/0x210
>         [<ffffffff829fce6a>] kunit_generic_run_threadfn_adapter+0x4a/0x90
>         [<ffffffff81237cf6>] kthread+0x2b6/0x380
>         [<ffffffff81097add>] ret_from_fork+0x2d/0x70
>         [<ffffffff81003791>] ret_from_fork_asm+0x11/0x20
> 
> Fixes: 9f86d624292c ("mm/damon/vaddr-test: remove unnecessary variables")
> Fixes: dae0087aeff4 ("mm/damon/vaddr: remove damon_va_apply_three_regions()")

Seems this patch fixes only 9f86d624292c if I'm not missing something?  So,
could we simply remove above 'Fixes: dae0087aeff4' line?

Seems Andrew also found[1] this and made the change[2] when adding this into
the queue.  Thank you, Andrew!  If something wrong, please let us know, Jinjie.

> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>

Other than above trivial nit,

Reviewed-by: SeongJae Park <sj@kernel.org>

[1] https://lore.kernel.org/damon/20230925081400.9593189a7665c6ff1f812855@linux-foundation.org/
[2] https://lore.kernel.org/mm-commits/20230925151450.EC64BC433C9@smtp.kernel.org/


Thanks,
SJ

> ---
>  mm/damon/vaddr-test.h | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/mm/damon/vaddr-test.h b/mm/damon/vaddr-test.h
> index c4b455b5ee30..dcf1ca6b31cc 100644
> --- a/mm/damon/vaddr-test.h
> +++ b/mm/damon/vaddr-test.h
> @@ -148,6 +148,8 @@ static void damon_do_test_apply_three_regions(struct kunit *test,
>  		KUNIT_EXPECT_EQ(test, r->ar.start, expected[i * 2]);
>  		KUNIT_EXPECT_EQ(test, r->ar.end, expected[i * 2 + 1]);
>  	}
> +
> +	damon_destroy_target(t);
>  }
>  
>  /*
> -- 
> 2.34.1


  parent reply	other threads:[~2023-09-25 16:03 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-09-25  7:20 Jinjie Ruan
2023-09-25 15:14 ` Andrew Morton
2023-09-26  1:39   ` Ruan Jinjie
2023-09-25 16:03 ` SeongJae Park [this message]
2023-09-26  1:37   ` Ruan Jinjie

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