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