kmsan: introduce test_unpoison_memory()

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.

[glider@google.com: change description, remove comment about failing test case]
Link: https://lkml.kernel.org/r/20240528104807.738758-2-glider@google.com
Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com>
Link: https://lore.kernel.org/lkml/20240524232804.1984355-1-bjohannesmeyer@gmail.com/T/
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Brian Johannesmeyer 2024-05-28 12:48:07 +02:00 committed by Andrew Morton
parent f56810c94c
commit 7005e7ec28

View File

@ -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),
{},
};