Re: FAILED: patch "[PATCH] mm/damon/tests/core-kunit: handle alloc failures on" failed to apply to 6.6-stable tree

[SeongJae Park <sj@kernel.org>]

On Mon, 05 Jan 2026 12:05:33 +0100 <gregkh@linuxfoundation.org> wrote:

> 
> The patch below does not apply to the 6.6-stable tree.
[...]
> ------------------ original commit in Linus's tree ------------------
> 
> >From eded254cb69044bd4abde87394ea44909708d7c0 Mon Sep 17 00:00:00 2001
> From: SeongJae Park <sj@kernel.org>
> Date: Sat, 1 Nov 2025 11:20:02 -0700
> Subject: [PATCH] mm/damon/tests/core-kunit: handle alloc failures on
>  damon_test_split_regions_of()
> 
> damon_test_split_regions_of() is assuming all dynamic memory allocation in
> it will succeed.  Those are indeed likely in the real use cases since
> those allocations are too small to fail, but theoretically those could
> fail.  In the case, inappropriate memory access can happen.  Fix it by
> appropriately cleanup pre-allocated memory and skip the execution of the
> remaining tests in the failure cases.
> 
> Link: https://lkml.kernel.org/r/20251101182021.74868-9-sj@kernel.org
> Fixes: 17ccae8bb5c9 ("mm/damon: add kunit tests")
> Signed-off-by: SeongJae Park <sj@kernel.org>
> Cc: Brendan Higgins <brendan.higgins@linux.dev>
> Cc: David Gow <davidgow@google.com>
> Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
> Cc: <stable@vger.kernel.org>	[5.15+]
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> 
> diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h
> index 98f2a3de7cea..10618cdd188e 100644
> --- a/mm/damon/tests/core-kunit.h
> +++ b/mm/damon/tests/core-kunit.h
> @@ -278,15 +278,35 @@ static void damon_test_split_regions_of(struct kunit *test)
>  	struct damon_target *t;
>  	struct damon_region *r;
>  
> +	if (!c)
> +		kunit_skip("ctx alloc fail");

FYI, the above diff breaks build because kunit_skip() receives two arguments.
Yes, the upstreamed patch is broken.  But, it was not noticed because a patch
[1] silently fixing the issue has merged into the mainline together, as a part
of the same patch series.

My ported patch that just sent as a reply to this mail fixes this together.

[1] 80d725f96c44 ("mm/damon/tests/core-kunit: remove unused ctx in damon_test_split_regions_of()")


Thanks,
SJ

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