// SPDX-License-Identifier: GPL-2.0-only/* * rodata_test.c: functional test for mark_rodata_ro function * * (C) Copyright 2008 Intel Corporation * Author: Arjan van de Ven <arjan@linux.intel.com> */#define pr_fmt(fmt) "rodata_test: " fmt #include <linux/rodata_test.h>#include <linux/uaccess.h>#include <linux/mm.h>#include <asm/sections.h> #define TEST_VALUE 0xC3static const int rodata_test_data = TEST_VALUE; void rodata_test(void){	int zero = 0; 	/* test 1: read the value */	/* If this test fails, some previous testrun has clobbered the state */	if (unlikely(READ_ONCE(rodata_test_data) != TEST_VALUE)) {		pr_err("test 1 fails (start data)\n");		return;	} 	/* test 2: write to the variable; this should fault */	if (!copy_to_kernel_nofault((void *)&rodata_test_data,				(void *)&zero, sizeof(zero))) {		pr_err("test data was not read only\n");		return;	} 	/* test 3: check the value hasn't changed */	if (unlikely(READ_ONCE(rodata_test_data) != TEST_VALUE)) {		pr_err("test data was changed\n");		return;	} 	/* test 4: check if the rodata section is PAGE_SIZE aligned */	if (!PAGE_ALIGNED(__start_rodata)) {		pr_err("start of .rodata is not page size aligned\n");		return;	}	if (!PAGE_ALIGNED(__end_rodata)) {		pr_err("end of .rodata is not page size aligned\n");		return;	} 	pr_info("all tests were successful\n");}