damon_sysfs_set_targets() had a bug that can result in unexpected memory
usage and monitoring overhead increase. The bug has fixed by a previous
commit. Add a unit test for avoiding a similar bug of future.
Signed-off-by: SeongJae Park <sj@xxxxxxxxxx>
---
mm/damon/Kconfig | 12 ++++++
mm/damon/sysfs-test.h | 86 +++++++++++++++++++++++++++++++++++++++++++
mm/damon/sysfs.c | 2 +
3 files changed, 100 insertions(+)
create mode 100644 mm/damon/sysfs-test.h
diff --git a/mm/damon/Kconfig b/mm/damon/Kconfig
index 436c6b4cb5ec..29f43fbc2eff 100644
--- a/mm/damon/Kconfig
+++ b/mm/damon/Kconfig
@@ -59,6 +59,18 @@ config DAMON_SYSFS
This builds the sysfs interface for DAMON. The user space can use
the interface for arbitrary data access monitoring.
+config DAMON_SYSFS_KUNIT_TEST
+ bool "Test for damon debugfs interface" if !KUNIT_ALL_TESTS
+ depends on DAMON_SYSFS && KUNIT=y
+ default KUNIT_ALL_TESTS
+ help
+ This builds the DAMON sysfs interface Kunit test suite.
+
+ For more information on KUnit and unit tests in general, please refer
+ to the KUnit documentation.
+
+ If unsure, say N.
+
config DAMON_DBGFS
bool "DAMON debugfs interface (DEPRECATED!)"
depends on DAMON_VADDR && DAMON_PADDR && DEBUG_FS
diff --git a/mm/damon/sysfs-test.h b/mm/damon/sysfs-test.h
new file mode 100644
index 000000000000..73bdce2452c1
--- /dev/null
+++ b/mm/damon/sysfs-test.h
@@ -0,0 +1,86 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Data Access Monitor Unit Tests
+ *
+ * Author: SeongJae Park <sj@xxxxxxxxxx>
+ */
+
+#ifdef CONFIG_DAMON_SYSFS_KUNIT_TEST
+
+#ifndef _DAMON_SYSFS_TEST_H
+#define _DAMON_SYSFS_TEST_H
+
+#include <kunit/test.h>
+
+static unsigned int nr_damon_targets(struct damon_ctx *ctx)
+{
+ struct damon_target *t;
+ unsigned int nr_targets = 0;
+
+ damon_for_each_target(t, ctx)
+ nr_targets++;
+
+ return nr_targets;
+}
+
+static int __damon_sysfs_test_get_any_pid(int min, int max)
+{
+ struct pid *pid;
+ int i;
+
+ for (i = min; i <= max; i++) {
+ pid = find_get_pid(i);
+ if (pid) {
+ put_pid(pid);
+ return i;
+ }
+ }
+ return -1;
+}
+
+static void damon_sysfs_test_set_targets(struct kunit *test)
+{
+ struct damon_sysfs_targets *sysfs_targets;
+ struct damon_sysfs_target *sysfs_target;
+ struct damon_ctx *ctx;
+
+ sysfs_targets = damon_sysfs_targets_alloc();
+ sysfs_targets->nr = 1;
+ sysfs_targets->targets_arr = kmalloc_array(1,
+ sizeof(*sysfs_targets->targets_arr), GFP_KERNEL);
+
+ sysfs_target = damon_sysfs_target_alloc();
+ sysfs_target->pid = __damon_sysfs_test_get_any_pid(12, 100);
+ sysfs_target->regions = damon_sysfs_regions_alloc();
+ sysfs_targets->targets_arr[0] = sysfs_target;
+
+ ctx = damon_new_ctx();
+
+ damon_sysfs_set_targets(ctx, sysfs_targets);
+ KUNIT_EXPECT_EQ(test, 1u, nr_damon_targets(ctx));
+
+ sysfs_target->pid = __damon_sysfs_test_get_any_pid(
+ sysfs_target->pid + 1, 200);
+ damon_sysfs_set_targets(ctx, sysfs_targets);
+ KUNIT_EXPECT_EQ(test, 1u, nr_damon_targets(ctx));
+
+ damon_destroy_ctx(ctx);
+ kfree(sysfs_targets->targets_arr);
+ kfree(sysfs_targets);
+ kfree(sysfs_target);
+}
+
+static struct kunit_case damon_sysfs_test_cases[] = {
+ KUNIT_CASE(damon_sysfs_test_set_targets),
+ {},
+};
+
+static struct kunit_suite damon_sysfs_test_suite = {
+ .name = "damon-sysfs",
+ .test_cases = damon_sysfs_test_cases,
+};
+kunit_test_suite(damon_sysfs_test_suite);
+
+#endif /* _DAMON_SYSFS_TEST_H */
+
+#endif /* CONFIG_DAMON_SYSFS_KUNIT_TEST */
diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c
index 5268e8503722..d13e353bee52 100644
--- a/mm/damon/sysfs.c
+++ b/mm/damon/sysfs.c
@@ -1804,3 +1804,5 @@ static int __init damon_sysfs_init(void)
return err;
}
subsys_initcall(damon_sysfs_init);
+
+#include "sysfs-test.h"
--
2.34.1
