FAILED: patch "[PATCH] mm/damon/core-kunit: extend damos_commit_filter_for() for wrong input" failed to apply to 6.6-stable tree

[Sasha Levin <sashal@kernel.org>]

The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x a1c7fdaf165755fff928a6c25b69d7e0966b6910
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '20261107053357-failed-6.6-a1c7fdaf1657@kernel.org' --subject-prefix 'PATCH 6.6.y' 'HEAD^..'

Thanks,
Sasha

------------------ original commit in Linus's tree ------------------

From a1c7fdaf165755fff928a6c25b69d7e0966b6910 Mon Sep 17 00:00:00 2001
From: SJ Park <sj@kernel.org>
Date: Mon, 14 Sep 2026 07:23:24 -0700
Subject: [PATCH] mm/damon/core-kunit: extend damos_commit_filter_for() for
 wrong input

damos_commit_filter_for() supposes damos_commit_filter() to always succeed
with given inputs.  damos_commit_filter() could return an error for
invalid inputs.  Existing callers always pass only valid inputs, but they
may pass invalid inputs in future, for test purposes.  Extend the function
to be able to be used for wrong inputs-caused error testing.

Link: https://lore.kernel.org/20260914142327.92510-8-sj@kernel.org
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Gow <davidgow@davidgow.net>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: <stable@vger.kernel.org>
---
 mm/damon/tests/core-kunit.h | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h
index c01e6a75cadc1..2b0931cf6fb32 100644
--- a/mm/damon/tests/core-kunit.h
+++ b/mm/damon/tests/core-kunit.h
@@ -1116,9 +1116,15 @@ static void damos_test_commit_dests(struct kunit *test)
 }
 
 static void damos_test_commit_filter_for(struct kunit *test,
-		struct damos_filter *dst, struct damos_filter *src)
+		struct damos_filter *dst, struct damos_filter *src,
+		bool expect_fail)
 {
-	damos_commit_filter(dst, src);
+	int err;
+
+	err = damos_commit_filter(dst, src);
+	KUNIT_EXPECT_EQ(test, err != 0, expect_fail);
+	if (expect_fail)
+		return;
 	KUNIT_EXPECT_EQ(test, dst->type, src->type);
 	KUNIT_EXPECT_EQ(test, dst->matching, src->matching);
 	KUNIT_EXPECT_EQ(test, dst->allow, src->allow);
@@ -1157,47 +1163,47 @@ static void damos_test_commit_filter(struct kunit *test)
 			.type = DAMOS_FILTER_TYPE_ANON,
 			.matching = true,
 			.allow = true,
-			});
+			}, false);
 	damos_test_commit_filter_for(test, &dst,
 			&(struct damos_filter){
 			.type = DAMOS_FILTER_TYPE_MEMCG,
 			.matching = false,
 			.allow = false,
 			.memcg_id = 123,
-			});
+			}, false);
 	damos_test_commit_filter_for(test, &dst,
 			&(struct damos_filter){
 			.type = DAMOS_FILTER_TYPE_YOUNG,
 			.matching = true,
 			.allow = true,
-			});
+			}, false);
 	damos_test_commit_filter_for(test, &dst,
 			&(struct damos_filter){
 			.type = DAMOS_FILTER_TYPE_HUGEPAGE_SIZE,
 			.matching = false,
 			.allow = false,
 			.sz_range = {.min = 234, .max = 345},
-			});
+			}, false);
 	damos_test_commit_filter_for(test, &dst,
 			&(struct damos_filter){
 			.type = DAMOS_FILTER_TYPE_UNMAPPED,
 			.matching = true,
 			.allow = true,
-			});
+			}, false);
 	damos_test_commit_filter_for(test, &dst,
 			&(struct damos_filter){
 			.type = DAMOS_FILTER_TYPE_ADDR,
 			.matching = false,
 			.allow = false,
 			.addr_range = {.start = 456, .end = 567},
-			});
+			}, false);
 	damos_test_commit_filter_for(test, &dst,
 			&(struct damos_filter){
 			.type = DAMOS_FILTER_TYPE_TARGET,
 			.matching = true,
 			.allow = true,
 			.target_idx = 6,
-			});
+			}, false);
 }
 
 static void damos_test_help_initailize_scheme(struct damos *scheme)
-- 
2.53.0