87 lines
2.2 KiB
C
87 lines
2.2 KiB
C
|
/*
|
||
|
|
* test_rodata.c: functional test for mark_rodata_ro function
|
||
|
|
*
|
||
|
|
* (C) Copyright 2008 Intel Corporation
|
||
|
|
* Author: Arjan van de Ven <arjan@linux.intel.com>
|
||
|
|
*
|
||
|
|
* This program is free software; you can redistribute it and/or
|
||
|
|
* modify it under the terms of the GNU General Public License
|
||
|
|
* as published by the Free Software Foundation; version 2
|
||
|
|
* of the License.
|
||
|
|
*/
|
||
|
|
#include <linux/module.h>
|
||
|
|
#include <asm/sections.h>
|
||
|
|
extern int rodata_test_data;
|
||
|
|
|
||
|
|
int rodata_test(void)
|
||
|
|
{
|
||
|
|
unsigned long result;
|
||
|
|
unsigned long start, end;
|
||
|
|
|
||
|
|
/* test 1: read the value */
|
||
|
|
/* If this test fails, some previous testrun has clobbered the state */
|
||
|
|
if (!rodata_test_data) {
|
||
|
|
printk(KERN_ERR "rodata_test: test 1 fails (start data)\n");
|
||
|
|
return -ENODEV;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* test 2: write to the variable; this should fault */
|
||
|
|
/*
|
||
|
|
* If this test fails, we managed to overwrite the data
|
||
|
|
*
|
||
|
|
* This is written in assembly to be able to catch the
|
||
|
|
* exception that is supposed to happen in the correct
|
||
|
|
* case
|
||
|
|
*/
|
||
|
|
|
||
|
|
result = 1;
|
||
|
|
asm volatile(
|
||
|
|
"0: mov %[zero],(%[rodata_test])\n"
|
||
|
|
" mov %[zero], %[rslt]\n"
|
||
|
|
"1:\n"
|
||
|
|
".section .fixup,\"ax\"\n"
|
||
|
|
"2: jmp 1b\n"
|
||
|
|
".previous\n"
|
||
|
|
".section __ex_table,\"a\"\n"
|
||
|
|
" .align 16\n"
|
||
|
|
#ifdef CONFIG_X86_32
|
||
|
|
" .long 0b,2b\n"
|
||
|
|
#else
|
||
|
|
" .quad 0b,2b\n"
|
||
|
|
#endif
|
||
|
|
".previous"
|
||
|
|
: [rslt] "=r" (result)
|
||
|
|
: [rodata_test] "r" (&rodata_test_data), [zero] "r" (0UL)
|
||
|
|
);
|
||
|
|
|
||
|
|
|
||
|
|
if (!result) {
|
||
|
|
printk(KERN_ERR "rodata_test: test data was not read only\n");
|
||
|
|
return -ENODEV;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* test 3: check the value hasn't changed */
|
||
|
|
/* If this test fails, we managed to overwrite the data */
|
||
|
|
if (!rodata_test_data) {
|
||
|
|
printk(KERN_ERR "rodata_test: Test 3 failes (end data)\n");
|
||
|
|
return -ENODEV;
|
||
|
|
}
|
||
|
|
/* test 4: check if the rodata section is 4Kb aligned */
|
||
|
|
start = (unsigned long)__start_rodata;
|
||
|
|
end = (unsigned long)__end_rodata;
|
||
|
|
if (start & (PAGE_SIZE - 1)) {
|
||
|
|
printk(KERN_ERR "rodata_test: .rodata is not 4k aligned\n");
|
||
|
|
return -ENODEV;
|
||
|
|
}
|
||
|
|
if (end & (PAGE_SIZE - 1)) {
|
||
|
|
printk(KERN_ERR "rodata_test: .rodata end is not 4k aligned\n");
|
||
|
|
return -ENODEV;
|
||
|
|
}
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
MODULE_LICENSE("GPL");
|
||
|
|
MODULE_DESCRIPTION("Testcase for the DEBUG_RODATA infrastructure");
|
||
|
|
MODULE_AUTHOR("Arjan van de Ven <arjan@linux.intel.com>");
|