2 * rodata_test.c: functional test for mark_rodata_ro function
4 * (C) Copyright 2008 Intel Corporation
5 * Author: Arjan van de Ven <arjan@linux.intel.com>
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; version 2
12 #define pr_fmt(fmt) "rodata_test: " fmt
14 #include <linux/uaccess.h>
15 #include <asm/sections.h>
17 const int rodata_test_data = 0xC3;
19 void rodata_test(void)
21 unsigned long start, end;
24 /* test 1: read the value */
25 /* If this test fails, some previous testrun has clobbered the state */
26 if (!rodata_test_data) {
27 pr_err("test 1 fails (start data)\n");
31 /* test 2: write to the variable; this should fault */
32 if (!probe_kernel_write((void *)&rodata_test_data,
33 (void *)&zero, sizeof(zero))) {
34 pr_err("test data was not read only\n");
38 /* test 3: check the value hasn't changed */
39 if (rodata_test_data == zero) {
40 pr_err("test data was changed\n");
44 /* test 4: check if the rodata section is PAGE_SIZE aligned */
45 start = (unsigned long)__start_rodata;
46 end = (unsigned long)__end_rodata;
47 if (start & (PAGE_SIZE - 1)) {
48 pr_err("start of .rodata is not page size aligned\n");
51 if (end & (PAGE_SIZE - 1)) {
52 pr_err("end of .rodata is not page size aligned\n");
56 pr_info("all tests were successful\n");