mm/damon/tests/core-kunit: handle alloc failures on damon_test_merge_two()

damon_test_merge_two() 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/20251101182021.74868-7-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 f5f3152cb8df3261e21572cdae704150ac3fb690..e8219fd23318dcca46423f2aa0021de08fbded11 100644 (file)
--- a/mm/damon/tests/core-kunit.h
+++ b/mm/damon/tests/core-kunit.h
@@ -188,11 +188,21 @@ static void damon_test_merge_two(struct kunit *test)
        int i;
 
        t = damon_new_target();
+       if (!t)
+               kunit_skip(test, "target alloc fail");
        r = damon_new_region(0, 100);
+       if (!r) {
+               damon_free_target(t);
+               kunit_skip(test, "region alloc fail");
+       }
        r->nr_accesses = 10;
        r->nr_accesses_bp = 100000;
        damon_add_region(r, t);
        r2 = damon_new_region(100, 300);
+       if (!r2) {
+               damon_free_target(t);
+               kunit_skip(test, "second region alloc fail");
+       }
        r2->nr_accesses = 20;
        r2->nr_accesses_bp = 200000;
        damon_add_region(r2, t);