[RFC,6/7] kstate, test: add test module for testing kstate subsystem.

Commit Message

Andrey Ryabinin Oct. 2, 2024, 4:07 p.m. UTC

This is simple test and playground useful kstate subsystem development.
It contains some structure with different kind of data which migrated
across kexec to the new kernel using kstate.

Signed-off-by: Andrey Ryabinin <[e-mail]>
---
 include/linux/kstate.h |  1 +
 lib/Makefile           |  2 +
 lib/test_kstate.c      | 89 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 92 insertions(+)
 create mode 100644 lib/test_kstate.c

Patch

diff --git a/include/linux/kstate.h b/include/linux/kstate.h
index 855acb339d5d7..2ddbe41a1f171 100644
--- a/include/linux/kstate.h
+++ b/include/linux/kstate.h
@@ -31,6 +31,7 @@  struct kstate_field {
 enum kstate_ids {
 	KSTATE_PAGE_ID,
 	KSTATE_RSVD_MEM_ID,
+	KSTATE_TEST_ID,
 	KSTATE_LAST_ID = -1,
 };
 
diff --git a/lib/Makefile b/lib/Makefile
index 773adf88af416..2432e47664c35 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -354,6 +354,8 @@  obj-$(CONFIG_PARMAN) += parman.o
 
 obj-y += group_cpus.o
 
+obj-$(CONFIG_KSTATE) += test_kstate.o
+
 # GCC library routines
 obj-$(CONFIG_GENERIC_LIB_ASHLDI3) += ashldi3.o
 obj-$(CONFIG_GENERIC_LIB_ASHRDI3) += ashrdi3.o
diff --git a/lib/test_kstate.c b/lib/test_kstate.c
new file mode 100644
index 0000000000000..e95e3110f8949
--- /dev/null
+++ b/lib/test_kstate.c
@@ -0,0 +1,89 @@ 
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/io.h>
+#include <linux/kstate.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+
+unsigned long ulong_val;
+struct kstate_test_data {
+	int i;
+	unsigned long *p_ulong;
+	char s[10];
+	struct page *page;
+};
+
+struct kstate_description test_state = {
+	.name = "test",
+	.version_id = 1,
+	.id = KSTATE_TEST_ID,
+	.state_list = LIST_HEAD_INIT(test_state.state_list),
+	.fields = (const struct kstate_field[]) {
+		KSTATE_SIMPLE(i, struct kstate_test_data),
+		KSTATE_SIMPLE(s, struct kstate_test_data),
+		KSTATE_POINTER(p_ulong, struct kstate_test_data),
+		{
+			.name = "page",
+			.flags = KS_CUSTOM,
+			.offset = offsetof(struct kstate_test_data, page),
+			.save = kstate_page_save,
+		},
+		KSTATE_SIMPLE(page, struct kstate_test_data),
+		KSTATE_END_OF_LIST()
+	},
+};
+
+static struct kstate_test_data test_data;
+
+static int init_test_data(void)
+{
+	struct page *page;
+	int i;
+
+	test_data.i = 10;
+	ulong_val = 20;
+	memcpy(test_data.s, "abcdefghk", sizeof(test_data.s));
+	page = alloc_page(GFP_KERNEL);
+	if (!page)
+		return -ENOMEM;
+
+	for (i = 0; i < PAGE_SIZE/4; i += 4)
+		*((u32 *)page_address(page) + i) = 0xdeadbeef;
+	test_data.page = page;
+	return 0;
+}
+
+static void validate_test_data(void)
+{
+	int i;
+
+	WARN_ON(test_data.i != 10);
+	WARN_ON(*test_data.p_ulong != 20);
+	WARN_ON(strcmp(test_data.s, "abcdefghk") != 0);
+
+	for (i = 0; i < PAGE_SIZE/4; i += 4) {
+		u32 val = *((u32 *)page_address(test_data.page) + i);
+
+		WARN_ON(val != 0xdeadbeef);
+	}
+}
+
+static int __init test_kstate_init(void)
+{
+	int ret = 0;
+
+	test_data.p_ulong = &ulong_val;
+
+	if (!is_migrate_kernel()) {
+		ret = init_test_data();
+		if (ret)
+			goto out;
+	}
+
+	kstate_register(&test_state, &test_data);
+
+	validate_test_data();
+
+out:
+	return ret;
+}
+__initcall(test_kstate_init);