[PATCH v2 2/2] mm: kmsan: add test_uninit_page

[Alexander Potapenko <glider@google.com>]

Test that pages allocated with alloc_page() are uninitialized
by default.

Signed-off-by: Alexander Potapenko <glider@google.com>
---
 mm/kmsan/kmsan_test.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/mm/kmsan/kmsan_test.c b/mm/kmsan/kmsan_test.c
index ba44bf2072bbe..81e642db6e239 100644
--- a/mm/kmsan/kmsan_test.c
+++ b/mm/kmsan/kmsan_test.c
@@ -378,6 +378,20 @@ static void test_uaf(struct kunit *test)
 	KUNIT_EXPECT_TRUE(test, report_matches(&expect));
 }
 
+static void test_uninit_page(struct kunit *test)
+{
+	EXPECTATION_UNINIT_VALUE(expect);
+	struct page *page;
+	int *ptr;
+
+	kunit_info(test, "uninitialized page allocation (UMR report)\n");
+	page = alloc_pages(GFP_KERNEL, 0);
+	ptr = page_address(page);
+	USE(*ptr);
+	__free_pages(page, 0);
+	KUNIT_EXPECT_TRUE(test, report_matches(&expect));
+}
+
 static volatile char *test_uaf_pages_helper(int order, int offset)
 {
 	struct page *page;
@@ -727,6 +741,7 @@ static struct kunit_case kmsan_test_cases[] = {
 	KUNIT_CASE(test_uninit_kmsan_check_memory),
 	KUNIT_CASE(test_init_kmsan_vmap_vunmap),
 	KUNIT_CASE(test_init_vmalloc),
+	KUNIT_CASE(test_uninit_page),
 	KUNIT_CASE(test_uaf),
 	KUNIT_CASE(test_uaf_pages),
 	KUNIT_CASE(test_uaf_high_order_pages),
-- 
2.52.0.457.g6b5491de43-goog