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
18 int 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
45 int main(void)
46 {
47 return test_harness(test_prot_sao, "prot-sao");
48 }
49
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