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authorLinus Torvalds2024-05-13 10:13:39 -0700
committerLinus Torvalds2024-05-13 10:13:39 -0700
commitc07ea940a011343fdaec12cd74b4ff947ba6f893 (patch)
tree2c3f2cba024008409e948d56e29c58697af918f8 /kernel
parentee20260136095c8037d8f94f0471eb9f7e3da99f (diff)
parent31f605a308e627f06e4e6ab77254473f1c90f0bf (diff)
Merge tag 'kcsan.2024.05.10a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
Pull kcsan update from Paul McKenney: "Introduce __data_racy type qualifier This adds a __data_racy type qualifier that enables kernel developers to inform KCSAN that a given variable is a shared variable without needing to mark each and every access. This allows pre-KCSAN code to be correctly (if approximately) instrumented withh very little effort, and also provides people reading the code a clear indication that the variable is in fact shared. In addition, it permits incremental transition to per-access KCSAN marking, so that (for example) a given subsystem can be transitioned one variable at a time, while avoiding large numbers of KCSAN warnings during this transition" * tag 'kcsan.2024.05.10a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: kcsan, compiler_types: Introduce __data_racy type qualifier
Diffstat (limited to 'kernel')
-rw-r--r--kernel/kcsan/kcsan_test.c17
1 files changed, 17 insertions, 0 deletions
diff --git a/kernel/kcsan/kcsan_test.c b/kernel/kcsan/kcsan_test.c
index 015586217875..0c17b4c83e1c 100644
--- a/kernel/kcsan/kcsan_test.c
+++ b/kernel/kcsan/kcsan_test.c
@@ -304,6 +304,7 @@ static long test_array[3 * PAGE_SIZE / sizeof(long)];
static struct {
long val[8];
} test_struct;
+static long __data_racy test_data_racy;
static DEFINE_SEQLOCK(test_seqlock);
static DEFINE_SPINLOCK(test_spinlock);
static DEFINE_MUTEX(test_mutex);
@@ -358,6 +359,8 @@ static noinline void test_kernel_write_uninstrumented(void) { test_var++; }
static noinline void test_kernel_data_race(void) { data_race(test_var++); }
+static noinline void test_kernel_data_racy_qualifier(void) { test_data_racy++; }
+
static noinline void test_kernel_assert_writer(void)
{
ASSERT_EXCLUSIVE_WRITER(test_var);
@@ -1009,6 +1012,19 @@ static void test_data_race(struct kunit *test)
KUNIT_EXPECT_FALSE(test, match_never);
}
+/* Test the __data_racy type qualifier. */
+__no_kcsan
+static void test_data_racy_qualifier(struct kunit *test)
+{
+ bool match_never = false;
+
+ begin_test_checks(test_kernel_data_racy_qualifier, test_kernel_data_racy_qualifier);
+ do {
+ match_never = report_available();
+ } while (!end_test_checks(match_never));
+ KUNIT_EXPECT_FALSE(test, match_never);
+}
+
__no_kcsan
static void test_assert_exclusive_writer(struct kunit *test)
{
@@ -1424,6 +1440,7 @@ static struct kunit_case kcsan_test_cases[] = {
KCSAN_KUNIT_CASE(test_read_plain_atomic_rmw),
KCSAN_KUNIT_CASE(test_zero_size_access),
KCSAN_KUNIT_CASE(test_data_race),
+ KCSAN_KUNIT_CASE(test_data_racy_qualifier),
KCSAN_KUNIT_CASE(test_assert_exclusive_writer),
KCSAN_KUNIT_CASE(test_assert_exclusive_access),
KCSAN_KUNIT_CASE(test_assert_exclusive_access_writer),