Greg Kroah-Hartman | b244131 | 2017-11-01 15:07:57 +0100 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
Andy Lutomirski | 0eb1d0f | 2017-02-22 07:36:17 -0800 | [diff] [blame] | 2 | /* |
| 3 | * ioperm.c - Test case for ioperm(2) |
| 4 | * Copyright (c) 2015 Andrew Lutomirski |
| 5 | */ |
| 6 | |
| 7 | #define _GNU_SOURCE |
| 8 | #include <err.h> |
| 9 | #include <stdio.h> |
| 10 | #include <stdint.h> |
| 11 | #include <signal.h> |
| 12 | #include <setjmp.h> |
| 13 | #include <stdlib.h> |
| 14 | #include <string.h> |
| 15 | #include <errno.h> |
| 16 | #include <unistd.h> |
| 17 | #include <sys/types.h> |
| 18 | #include <sys/wait.h> |
| 19 | #include <stdbool.h> |
| 20 | #include <sched.h> |
| 21 | #include <sys/io.h> |
| 22 | |
| 23 | static int nerrs = 0; |
| 24 | |
| 25 | static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *), |
| 26 | int flags) |
| 27 | { |
| 28 | struct sigaction sa; |
| 29 | memset(&sa, 0, sizeof(sa)); |
| 30 | sa.sa_sigaction = handler; |
| 31 | sa.sa_flags = SA_SIGINFO | flags; |
| 32 | sigemptyset(&sa.sa_mask); |
| 33 | if (sigaction(sig, &sa, 0)) |
| 34 | err(1, "sigaction"); |
| 35 | |
| 36 | } |
| 37 | |
| 38 | static void clearhandler(int sig) |
| 39 | { |
| 40 | struct sigaction sa; |
| 41 | memset(&sa, 0, sizeof(sa)); |
| 42 | sa.sa_handler = SIG_DFL; |
| 43 | sigemptyset(&sa.sa_mask); |
| 44 | if (sigaction(sig, &sa, 0)) |
| 45 | err(1, "sigaction"); |
| 46 | } |
| 47 | |
| 48 | static jmp_buf jmpbuf; |
| 49 | |
| 50 | static void sigsegv(int sig, siginfo_t *si, void *ctx_void) |
| 51 | { |
| 52 | siglongjmp(jmpbuf, 1); |
| 53 | } |
| 54 | |
| 55 | static bool try_outb(unsigned short port) |
| 56 | { |
| 57 | sethandler(SIGSEGV, sigsegv, SA_RESETHAND); |
| 58 | if (sigsetjmp(jmpbuf, 1) != 0) { |
| 59 | return false; |
| 60 | } else { |
| 61 | asm volatile ("outb %%al, %w[port]" |
| 62 | : : [port] "Nd" (port), "a" (0)); |
| 63 | return true; |
| 64 | } |
| 65 | clearhandler(SIGSEGV); |
| 66 | } |
| 67 | |
| 68 | static void expect_ok(unsigned short port) |
| 69 | { |
| 70 | if (!try_outb(port)) { |
| 71 | printf("[FAIL]\toutb to 0x%02hx failed\n", port); |
| 72 | exit(1); |
| 73 | } |
| 74 | |
| 75 | printf("[OK]\toutb to 0x%02hx worked\n", port); |
| 76 | } |
| 77 | |
| 78 | static void expect_gp(unsigned short port) |
| 79 | { |
| 80 | if (try_outb(port)) { |
| 81 | printf("[FAIL]\toutb to 0x%02hx worked\n", port); |
| 82 | exit(1); |
| 83 | } |
| 84 | |
| 85 | printf("[OK]\toutb to 0x%02hx failed\n", port); |
| 86 | } |
| 87 | |
| 88 | int main(void) |
| 89 | { |
| 90 | cpu_set_t cpuset; |
| 91 | CPU_ZERO(&cpuset); |
| 92 | CPU_SET(0, &cpuset); |
| 93 | if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0) |
| 94 | err(1, "sched_setaffinity to CPU 0"); |
| 95 | |
| 96 | expect_gp(0x80); |
| 97 | expect_gp(0xed); |
| 98 | |
| 99 | /* |
| 100 | * Probe for ioperm support. Note that clearing ioperm bits |
| 101 | * works even as nonroot. |
| 102 | */ |
| 103 | printf("[RUN]\tenable 0x80\n"); |
| 104 | if (ioperm(0x80, 1, 1) != 0) { |
| 105 | printf("[OK]\tioperm(0x80, 1, 1) failed (%d) -- try running as root\n", |
| 106 | errno); |
| 107 | return 0; |
| 108 | } |
| 109 | expect_ok(0x80); |
| 110 | expect_gp(0xed); |
| 111 | |
| 112 | printf("[RUN]\tdisable 0x80\n"); |
| 113 | if (ioperm(0x80, 1, 0) != 0) { |
| 114 | printf("[FAIL]\tioperm(0x80, 1, 0) failed (%d)", errno); |
| 115 | return 1; |
| 116 | } |
| 117 | expect_gp(0x80); |
| 118 | expect_gp(0xed); |
| 119 | |
| 120 | /* Make sure that fork() preserves ioperm. */ |
| 121 | if (ioperm(0x80, 1, 1) != 0) { |
| 122 | printf("[FAIL]\tioperm(0x80, 1, 0) failed (%d)", errno); |
| 123 | return 1; |
| 124 | } |
| 125 | |
| 126 | pid_t child = fork(); |
| 127 | if (child == -1) |
| 128 | err(1, "fork"); |
| 129 | |
| 130 | if (child == 0) { |
| 131 | printf("[RUN]\tchild: check that we inherited permissions\n"); |
| 132 | expect_ok(0x80); |
| 133 | expect_gp(0xed); |
| 134 | return 0; |
| 135 | } else { |
| 136 | int status; |
| 137 | if (waitpid(child, &status, 0) != child || |
| 138 | !WIFEXITED(status)) { |
| 139 | printf("[FAIL]\tChild died\n"); |
| 140 | nerrs++; |
| 141 | } else if (WEXITSTATUS(status) != 0) { |
| 142 | printf("[FAIL]\tChild failed\n"); |
| 143 | nerrs++; |
| 144 | } else { |
| 145 | printf("[OK]\tChild succeeded\n"); |
| 146 | } |
| 147 | } |
| 148 | |
| 149 | /* Test the capability checks. */ |
| 150 | |
| 151 | printf("\tDrop privileges\n"); |
| 152 | if (setresuid(1, 1, 1) != 0) { |
| 153 | printf("[WARN]\tDropping privileges failed\n"); |
| 154 | return 0; |
| 155 | } |
| 156 | |
| 157 | printf("[RUN]\tdisable 0x80\n"); |
| 158 | if (ioperm(0x80, 1, 0) != 0) { |
| 159 | printf("[FAIL]\tioperm(0x80, 1, 0) failed (%d)", errno); |
| 160 | return 1; |
| 161 | } |
| 162 | printf("[OK]\tit worked\n"); |
| 163 | |
| 164 | printf("[RUN]\tenable 0x80 again\n"); |
| 165 | if (ioperm(0x80, 1, 1) == 0) { |
| 166 | printf("[FAIL]\tit succeeded but should have failed.\n"); |
| 167 | return 1; |
| 168 | } |
| 169 | printf("[OK]\tit failed\n"); |
| 170 | return 0; |
| 171 | } |