diff options
Diffstat (limited to 'tools/testing/selftests/x86/ioperm.c')
| -rw-r--r-- | tools/testing/selftests/x86/ioperm.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/tools/testing/selftests/x86/ioperm.c b/tools/testing/selftests/x86/ioperm.c new file mode 100644 index 0000000000..57ec5e99ed --- /dev/null +++ b/tools/testing/selftests/x86/ioperm.c @@ -0,0 +1,185 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * ioperm.c - Test case for ioperm(2) + * Copyright (c) 2015 Andrew Lutomirski + */ + +#define _GNU_SOURCE +#include <err.h> +#include <stdio.h> +#include <stdint.h> +#include <signal.h> +#include <setjmp.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> +#include <unistd.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <stdbool.h> +#include <sched.h> +#include <sys/io.h> + +static int nerrs = 0; + +static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *), + int flags) +{ + struct sigaction sa; + memset(&sa, 0, sizeof(sa)); + sa.sa_sigaction = handler; + sa.sa_flags = SA_SIGINFO | flags; + sigemptyset(&sa.sa_mask); + if (sigaction(sig, &sa, 0)) + err(1, "sigaction"); + +} + +static void clearhandler(int sig) +{ + struct sigaction sa; + memset(&sa, 0, sizeof(sa)); + sa.sa_handler = SIG_DFL; + sigemptyset(&sa.sa_mask); + if (sigaction(sig, &sa, 0)) + err(1, "sigaction"); +} + +static jmp_buf jmpbuf; + +static void sigsegv(int sig, siginfo_t *si, void *ctx_void) +{ + siglongjmp(jmpbuf, 1); +} + +static bool try_outb(unsigned short port) +{ + sethandler(SIGSEGV, sigsegv, SA_RESETHAND); + if (sigsetjmp(jmpbuf, 1) != 0) { + return false; + } else { + asm volatile ("outb %%al, %w[port]" + : : [port] "Nd" (port), "a" (0)); + return true; + } + clearhandler(SIGSEGV); +} + +static void expect_ok(unsigned short port) +{ + if (!try_outb(port)) { + printf("[FAIL]\toutb to 0x%02hx failed\n", port); + exit(1); + } + + printf("[OK]\toutb to 0x%02hx worked\n", port); +} + +static void expect_gp(unsigned short port) +{ + if (try_outb(port)) { + printf("[FAIL]\toutb to 0x%02hx worked\n", port); + exit(1); + } + + printf("[OK]\toutb to 0x%02hx failed\n", port); +} + +int main(void) +{ + cpu_set_t cpuset; + CPU_ZERO(&cpuset); + CPU_SET(0, &cpuset); + if (sched_setaffinity(0, sizeof(cpuset), &cpuset) != 0) + err(1, "sched_setaffinity to CPU 0"); + + expect_gp(0x80); + expect_gp(0xed); + + /* + * Probe for ioperm support. Note that clearing ioperm bits + * works even as nonroot. + */ + printf("[RUN]\tenable 0x80\n"); + if (ioperm(0x80, 1, 1) != 0) { + printf("[OK]\tioperm(0x80, 1, 1) failed (%d) -- try running as root\n", + errno); + return 0; + } + expect_ok(0x80); + expect_gp(0xed); + + printf("[RUN]\tdisable 0x80\n"); + if (ioperm(0x80, 1, 0) != 0) { + printf("[FAIL]\tioperm(0x80, 1, 0) failed (%d)", errno); + return 1; + } + expect_gp(0x80); + expect_gp(0xed); + + /* Make sure that fork() preserves ioperm. */ + if (ioperm(0x80, 1, 1) != 0) { + printf("[FAIL]\tioperm(0x80, 1, 0) failed (%d)", errno); + return 1; + } + + pid_t child = fork(); + if (child == -1) + err(1, "fork"); + + if (child == 0) { + printf("[RUN]\tchild: check that we inherited permissions\n"); + expect_ok(0x80); + expect_gp(0xed); + printf("[RUN]\tchild: Extend permissions to 0x81\n"); + if (ioperm(0x81, 1, 1) != 0) { + printf("[FAIL]\tioperm(0x81, 1, 1) failed (%d)", errno); + return 1; + } + printf("[RUN]\tchild: Drop permissions to 0x80\n"); + if (ioperm(0x80, 1, 0) != 0) { + printf("[FAIL]\tioperm(0x80, 1, 0) failed (%d)", errno); + return 1; + } + expect_gp(0x80); + return 0; + } else { + int status; + if (waitpid(child, &status, 0) != child || + !WIFEXITED(status)) { + printf("[FAIL]\tChild died\n"); + nerrs++; + } else if (WEXITSTATUS(status) != 0) { + printf("[FAIL]\tChild failed\n"); + nerrs++; + } else { + printf("[OK]\tChild succeeded\n"); + } + } + + /* Verify that the child dropping 0x80 did not affect the parent */ + printf("\tVerify that unsharing the bitmap worked\n"); + expect_ok(0x80); + + /* Test the capability checks. */ + printf("\tDrop privileges\n"); + if (setresuid(1, 1, 1) != 0) { + printf("[WARN]\tDropping privileges failed\n"); + return 0; + } + + printf("[RUN]\tdisable 0x80\n"); + if (ioperm(0x80, 1, 0) != 0) { + printf("[FAIL]\tioperm(0x80, 1, 0) failed (%d)", errno); + return 1; + } + printf("[OK]\tit worked\n"); + + printf("[RUN]\tenable 0x80 again\n"); + if (ioperm(0x80, 1, 1) == 0) { + printf("[FAIL]\tit succeeded but should have failed.\n"); + return 1; + } + printf("[OK]\tit failed\n"); + return 0; +} |