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

damon_test_split_at() 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/20251101182021.74868-6-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 fd1e1ecaa2c911300a4640aabc433975548a6310..f5f3152cb8df3261e21572cdae704150ac3fb690 100644 (file)
--- a/mm/damon/tests/core-kunit.h
+++ b/mm/damon/tests/core-kunit.h
@@ -148,8 +148,19 @@ static void damon_test_split_at(struct kunit *test)
        struct damon_target *t;
        struct damon_region *r, *r_new;
 
+       if (!c)
+               kunit_skip(test, "ctx alloc fail");
        t = damon_new_target();
+       if (!t) {
+               damon_destroy_ctx(c);
+               kunit_skip(test, "target alloc fail");
+       }
        r = damon_new_region(0, 100);
+       if (!r) {
+               damon_destroy_ctx(c);
+               damon_free_target(t);
+               kunit_skip(test, "region alloc fail");
+       }
        r->nr_accesses_bp = 420000;
        r->nr_accesses = 42;
        r->last_nr_accesses = 15;