// SPDX-License-Identifier: GPL-2.0-only#include <linux/module.h>#include <linux/printk.h>#include <linux/slab.h>#include <linux/string.h> static __init int memset16_selftest(void){	unsigned i, j, k;	u16 v, *p; 	p = kmalloc(256 * 2 * 2, GFP_KERNEL);	if (!p)		return -1; 	for (i = 0; i < 256; i++) {		for (j = 0; j < 256; j++) {			memset(p, 0xa1, 256 * 2 * sizeof(v));			memset16(p + i, 0xb1b2, j);			for (k = 0; k < 512; k++) {				v = p[k];				if (k < i) {					if (v != 0xa1a1)						goto fail;				} else if (k < i + j) {					if (v != 0xb1b2)						goto fail;				} else {					if (v != 0xa1a1)						goto fail;				}			}		}	} fail:	kfree(p);	if (i < 256)		return (i << 24) | (j << 16) | k | 0x8000;	return 0;} static __init int memset32_selftest(void){	unsigned i, j, k;	u32 v, *p; 	p = kmalloc(256 * 2 * 4, GFP_KERNEL);	if (!p)		return -1; 	for (i = 0; i < 256; i++) {		for (j = 0; j < 256; j++) {			memset(p, 0xa1, 256 * 2 * sizeof(v));			memset32(p + i, 0xb1b2b3b4, j);			for (k = 0; k < 512; k++) {				v = p[k];				if (k < i) {					if (v != 0xa1a1a1a1)						goto fail;				} else if (k < i + j) {					if (v != 0xb1b2b3b4)						goto fail;				} else {					if (v != 0xa1a1a1a1)						goto fail;				}			}		}	} fail:	kfree(p);	if (i < 256)		return (i << 24) | (j << 16) | k | 0x8000;	return 0;} static __init int memset64_selftest(void){	unsigned i, j, k;	u64 v, *p; 	p = kmalloc(256 * 2 * 8, GFP_KERNEL);	if (!p)		return -1; 	for (i = 0; i < 256; i++) {		for (j = 0; j < 256; j++) {			memset(p, 0xa1, 256 * 2 * sizeof(v));			memset64(p + i, 0xb1b2b3b4b5b6b7b8ULL, j);			for (k = 0; k < 512; k++) {				v = p[k];				if (k < i) {					if (v != 0xa1a1a1a1a1a1a1a1ULL)						goto fail;				} else if (k < i + j) {					if (v != 0xb1b2b3b4b5b6b7b8ULL)						goto fail;				} else {					if (v != 0xa1a1a1a1a1a1a1a1ULL)						goto fail;				}			}		}	} fail:	kfree(p);	if (i < 256)		return (i << 24) | (j << 16) | k | 0x8000;	return 0;} static __init int strchr_selftest(void){	const char *test_string = "abcdefghijkl";	const char *empty_string = "";	char *result;	int i; 	for (i = 0; i < strlen(test_string) + 1; i++) {		result = strchr(test_string, test_string[i]);		if (result - test_string != i)			return i + 'a';	} 	result = strchr(empty_string, '\0');	if (result != empty_string)		return 0x101; 	result = strchr(empty_string, 'a');	if (result)		return 0x102; 	result = strchr(test_string, 'z');	if (result)		return 0x103; 	return 0;} static __init int strnchr_selftest(void){	const char *test_string = "abcdefghijkl";	const char *empty_string = "";	char *result;	int i, j; 	for (i = 0; i < strlen(test_string) + 1; i++) {		for (j = 0; j < strlen(test_string) + 2; j++) {			result = strnchr(test_string, j, test_string[i]);			if (j <= i) {				if (!result)					continue;				return ((i + 'a') << 8) | j;			}			if (result - test_string != i)				return ((i + 'a') << 8) | j;		}	} 	result = strnchr(empty_string, 0, '\0');	if (result)		return 0x10001; 	result = strnchr(empty_string, 1, '\0');	if (result != empty_string)		return 0x10002; 	result = strnchr(empty_string, 1, 'a');	if (result)		return 0x10003; 	result = strnchr(NULL, 0, '\0');	if (result)		return 0x10004; 	return 0;} static __init int string_selftest_init(void){	int test, subtest; 	test = 1;	subtest = memset16_selftest();	if (subtest)		goto fail; 	test = 2;	subtest = memset32_selftest();	if (subtest)		goto fail; 	test = 3;	subtest = memset64_selftest();	if (subtest)		goto fail; 	test = 4;	subtest = strchr_selftest();	if (subtest)		goto fail; 	test = 5;	subtest = strnchr_selftest();	if (subtest)		goto fail; 	pr_info("String selftests succeeded\n");	return 0;fail:	pr_crit("String selftest failure %d.%08x\n", test, subtest);	return 0;} module_init(string_selftest_init);MODULE_LICENSE("GPL v2");