// SPDX-License-Identifier: GPL-2.0-only#include <kunit/test.h> #include <linux/kernel.h>#include <linux/list_sort.h>#include <linux/list.h>#include <linux/module.h>#include <linux/printk.h>#include <linux/slab.h>#include <linux/random.h> /* * The pattern of set bits in the list length determines which cases * are hit in list_sort(). */#define TEST_LIST_LEN (512+128+2) /* not including head */ #define TEST_POISON1 0xDEADBEEF#define TEST_POISON2 0xA324354C struct debug_el {	unsigned int poison1;	struct list_head list;	unsigned int poison2;	int value;	unsigned int serial;}; static void check(struct kunit *test, const struct debug_el *ela, const struct debug_el *elb){	struct debug_el **elts = test->priv; 	KUNIT_EXPECT_LT_MSG(test, ela->serial, (unsigned int)TEST_LIST_LEN, "incorrect serial");	KUNIT_EXPECT_LT_MSG(test, elb->serial, (unsigned int)TEST_LIST_LEN, "incorrect serial"); 	KUNIT_EXPECT_PTR_EQ_MSG(test, elts[ela->serial], ela, "phantom element");	KUNIT_EXPECT_PTR_EQ_MSG(test, elts[elb->serial], elb, "phantom element"); 	KUNIT_EXPECT_EQ_MSG(test, ela->poison1, TEST_POISON1, "bad poison");	KUNIT_EXPECT_EQ_MSG(test, ela->poison2, TEST_POISON2, "bad poison"); 	KUNIT_EXPECT_EQ_MSG(test, elb->poison1, TEST_POISON1, "bad poison");	KUNIT_EXPECT_EQ_MSG(test, elb->poison2, TEST_POISON2, "bad poison");} /* `priv` is the test pointer so check() can fail the test if the list is invalid. */static int cmp(void *priv, const struct list_head *a, const struct list_head *b){	const struct debug_el *ela, *elb; 	ela = container_of(a, struct debug_el, list);	elb = container_of(b, struct debug_el, list); 	check(priv, ela, elb);	return ela->value - elb->value;} static void list_sort_test(struct kunit *test){	int i, count = 1;	struct debug_el *el, **elts;	struct list_head *cur;	LIST_HEAD(head); 	elts = kunit_kcalloc(test, TEST_LIST_LEN, sizeof(*elts), GFP_KERNEL);	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, elts);	test->priv = elts; 	for (i = 0; i < TEST_LIST_LEN; i++) {		el = kunit_kmalloc(test, sizeof(*el), GFP_KERNEL);		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, el); 		 /* force some equivalencies */		el->value = get_random_u32_below(TEST_LIST_LEN / 3);		el->serial = i;		el->poison1 = TEST_POISON1;		el->poison2 = TEST_POISON2;		elts[i] = el;		list_add_tail(&el->list, &head);	} 	list_sort(test, &head, cmp); 	for (cur = head.next; cur->next != &head; cur = cur->next) {		struct debug_el *el1;		int cmp_result; 		KUNIT_ASSERT_PTR_EQ_MSG(test, cur->next->prev, cur,					"list is corrupted"); 		cmp_result = cmp(test, cur, cur->next);		KUNIT_ASSERT_LE_MSG(test, cmp_result, 0, "list is not sorted"); 		el = container_of(cur, struct debug_el, list);		el1 = container_of(cur->next, struct debug_el, list);		if (cmp_result == 0) {			KUNIT_ASSERT_LE_MSG(test, el->serial, el1->serial,					    "order of equivalent elements not preserved");		} 		check(test, el, el1);		count++;	}	KUNIT_EXPECT_PTR_EQ_MSG(test, head.prev, cur, "list is corrupted"); 	KUNIT_EXPECT_EQ_MSG(test, count, TEST_LIST_LEN,			    "list length changed after sorting!");} static struct kunit_case list_sort_cases[] = {	KUNIT_CASE(list_sort_test),	{}}; static struct kunit_suite list_sort_suite = {	.name = "list_sort",	.test_cases = list_sort_cases,}; kunit_test_suites(&list_sort_suite); MODULE_DESCRIPTION("list_sort() KUnit test suite");MODULE_LICENSE("GPL");