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

damon_test_merge_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/20251101182021.74868-8-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 e8219fd23318dcca46423f2aa0021de08fbded11..98f2a3de7cea7d6b235aa210aaad6fd34b2c4d9d 100644 (file)
--- a/mm/damon/tests/core-kunit.h
+++ b/mm/damon/tests/core-kunit.h
@@ -248,8 +248,14 @@ static void damon_test_merge_regions_of(struct kunit *test)
        int i;
 
        t = damon_new_target();
+       if (!t)
+               kunit_skip(test, "target alloc fail");
        for (i = 0; i < ARRAY_SIZE(sa); i++) {
                r = damon_new_region(sa[i], ea[i]);
+               if (!r) {
+                       damon_free_target(t);
+                       kunit_skip(test, "region alloc fail");
+               }
                r->nr_accesses = nrs[i];
                r->nr_accesses_bp = nrs[i] * 10000;
                damon_add_region(r, t);