// 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/uaccess.h>#include <asm/sections.h> static const int rodata_test_data = 0xC3; void rodata_test(void){	unsigned long start, end;	int zero = 0; 	/* test 1: read the value */	/* If this test fails, some previous testrun has clobbered the state */	if (!rodata_test_data) {		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 (rodata_test_data == zero) {		pr_err("test data was changed\n");		return;	} 	/* test 4: check if the rodata section is PAGE_SIZE aligned */	start = (unsigned long)__start_rodata;	end = (unsigned long)__end_rodata;	if (start & (PAGE_SIZE - 1)) {		pr_err("start of .rodata is not page size aligned\n");		return;	}	if (end & (PAGE_SIZE - 1)) {		pr_err("end of .rodata is not page size aligned\n");		return;	} 	pr_info("all tests were successful\n");}