1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright 2016, Michael Ellerman, IBM Corp.
4  */
5 
6 #include <stdio.h>
7 #include <stdlib.h>
8 #include <string.h>
9 #include <sys/mman.h>
10 
11 #include <asm/cputable.h>
12 
13 #include "utils.h"
14 
15 #define SIZE (64 * 1024)
16 
17 int test_prot_sao(void)
18 {
19 	char *p;
20 
21 	/* SAO was introduced in 2.06 and removed in 3.1 */
22 	SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06) ||
23 		have_hwcap2(PPC_FEATURE2_ARCH_3_1));
24 
25 	/*
26 	 * Ensure we can ask for PROT_SAO.
27 	 * We can't really verify that it does the right thing, but at least we
28 	 * confirm the kernel will accept it.
29 	 */
30 	p = mmap(NULL, SIZE, PROT_READ | PROT_WRITE | PROT_SAO,
31 		 MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
32 	FAIL_IF(p == MAP_FAILED);
33 
34 	/* Write to the mapping, to at least cause a fault */
35 	memset(p, 0xaa, SIZE);
36 
37 	return 0;
38 }
39 
40 int main(void)
41 {
42 	return test_harness(test_prot_sao, "prot-sao");
43 }
44