From: Brian Johannesmeyer <bjohannesmeyer@xxxxxxxxx> Add a regression test to ensure that kmsan_unpoison_memory() works the same as an unpoisoning operation added by the instrumentation. The test has two subtests: one that checks the instrumentation, and one that checks kmsan_unpoison_memory(). Each subtest initializes the first byte of a 4-byte buffer, then checks that the other 3 bytes are uninitialized. Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@xxxxxxxxx> Link: https://lore.kernel.org/lkml/20240524232804.1984355-1-bjohannesmeyer@xxxxxxxxx/T/ [glider@xxxxxxxxxx: change description, remove comment about failing test case] Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx> --- mm/kmsan/kmsan_test.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/mm/kmsan/kmsan_test.c b/mm/kmsan/kmsan_test.c index 07d3a3a5a9c52..018069aba92be 100644 --- a/mm/kmsan/kmsan_test.c +++ b/mm/kmsan/kmsan_test.c @@ -614,6 +614,32 @@ static void test_stackdepot_roundtrip(struct kunit *test) KUNIT_EXPECT_TRUE(test, report_matches(&expect)); } +/* + * Test case: ensure that kmsan_unpoison_memory() and the instrumentation work + * the same. + */ +static void test_unpoison_memory(struct kunit *test) +{ + EXPECTATION_UNINIT_VALUE_FN(expect, "test_unpoison_memory"); + volatile char a[4], b[4]; + + kunit_info( + test, + "unpoisoning via the instrumentation vs. kmsan_unpoison_memory() (2 UMR reports)\n"); + + /* Initialize a[0] and check a[1]--a[3]. */ + a[0] = 0; + kmsan_check_memory((char *)&a[1], 3); + KUNIT_EXPECT_TRUE(test, report_matches(&expect)); + + report_reset(); + + /* Initialize b[0] and check b[1]--b[3]. */ + kmsan_unpoison_memory((char *)&b[0], 1); + kmsan_check_memory((char *)&b[1], 3); + KUNIT_EXPECT_TRUE(test, report_matches(&expect)); +} + static struct kunit_case kmsan_test_cases[] = { KUNIT_CASE(test_uninit_kmalloc), KUNIT_CASE(test_init_kmalloc), @@ -637,6 +663,7 @@ static struct kunit_case kmsan_test_cases[] = { KUNIT_CASE(test_memset64), KUNIT_CASE(test_long_origin_chain), KUNIT_CASE(test_stackdepot_roundtrip), + KUNIT_CASE(test_unpoison_memory), {}, }; -- 2.45.1.288.g0e0cd299f1-goog
