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authorAlexander Potapenko <glider@google.com>2023-03-06 14:13:22 +0300
committerAndrew Morton <akpm@linux-foundation.org>2023-03-29 02:20:14 +0300
commit6204c9ab4a5a05a72e04c12276fffdd6c6636489 (patch)
treeebc38eb9dace54e83e0a0649f2ba6fdc92abb8ac /mm/kmsan
parent8e00b2dffd822b34d8d1c627dc19f0743f9f5ac6 (diff)
downloadlinux-6204c9ab4a5a05a72e04c12276fffdd6c6636489.tar.xz
kmsan: add test_stackdepot_roundtrip
Ensure that KMSAN does not report false positives in instrumented callers of stack_depot_save(), stack_depot_print(), and stack_depot_fetch(). Link: https://lkml.kernel.org/r/20230306111322.205724-2-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Marco Elver <elver@google.com> Cc: syzbot <syzkaller@googlegroups.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/kmsan')
-rw-r--r--mm/kmsan/kmsan_test.c31
1 files changed, 31 insertions, 0 deletions
diff --git a/mm/kmsan/kmsan_test.c b/mm/kmsan/kmsan_test.c
index 7095d3fbb23a..d9eb141c27aa 100644
--- a/mm/kmsan/kmsan_test.c
+++ b/mm/kmsan/kmsan_test.c
@@ -551,6 +551,36 @@ static void test_long_origin_chain(struct kunit *test)
KUNIT_EXPECT_TRUE(test, report_matches(&expect));
}
+/*
+ * Test case: ensure that saving/restoring/printing stacks to/from stackdepot
+ * does not trigger errors.
+ *
+ * KMSAN uses stackdepot to store origin stack traces, that's why we do not
+ * instrument lib/stackdepot.c. Yet it must properly mark its outputs as
+ * initialized because other kernel features (e.g. netdev tracker) may also
+ * access stackdepot from instrumented code.
+ */
+static void test_stackdepot_roundtrip(struct kunit *test)
+{
+ unsigned long src_entries[16], *dst_entries;
+ unsigned int src_nentries, dst_nentries;
+ EXPECTATION_NO_REPORT(expect);
+ depot_stack_handle_t handle;
+
+ kunit_info(test, "testing stackdepot roundtrip (no reports)\n");
+
+ src_nentries =
+ stack_trace_save(src_entries, ARRAY_SIZE(src_entries), 1);
+ handle = stack_depot_save(src_entries, src_nentries, GFP_KERNEL);
+ stack_depot_print(handle);
+ dst_nentries = stack_depot_fetch(handle, &dst_entries);
+ KUNIT_EXPECT_TRUE(test, src_nentries == dst_nentries);
+
+ kmsan_check_memory((void *)dst_entries,
+ sizeof(*dst_entries) * dst_nentries);
+ KUNIT_EXPECT_TRUE(test, report_matches(&expect));
+}
+
static struct kunit_case kmsan_test_cases[] = {
KUNIT_CASE(test_uninit_kmalloc),
KUNIT_CASE(test_init_kmalloc),
@@ -573,6 +603,7 @@ static struct kunit_case kmsan_test_cases[] = {
KUNIT_CASE(test_memset32),
KUNIT_CASE(test_memset64),
KUNIT_CASE(test_long_origin_chain),
+ KUNIT_CASE(test_stackdepot_roundtrip),
{},
};