Orange Pi5 kernel

// 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 <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");
}