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#include <unistd.h>
11
12#include <asm/cputable.h>
13
14#include "utils.h"
15
16#define SIZE (64 * 1024)
17
18int test_prot_sao(void)
19{
20	char *p;
21
22	/*
23	 * SAO was introduced in 2.06 and removed in 3.1. It's disabled in
24	 * guests/LPARs by default, so also skip if we are running in a guest.
25	 */
26	SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06) ||
27		have_hwcap2(PPC_FEATURE2_ARCH_3_1) ||
28		access("/proc/device-tree/rtas/ibm,hypertas-functions", F_OK) == 0);
29
30	/*
31	 * Ensure we can ask for PROT_SAO.
32	 * We can't really verify that it does the right thing, but at least we
33	 * confirm the kernel will accept it.
34	 */
35	p = mmap(NULL, SIZE, PROT_READ | PROT_WRITE | PROT_SAO,
36		 MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
37	FAIL_IF(p == MAP_FAILED);
38
39	/* Write to the mapping, to at least cause a fault */
40	memset(p, 0xaa, SIZE);
41
42	return 0;
43}
44
45int main(void)
46{
47	return test_harness(test_prot_sao, "prot-sao");
48}
49