1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2018 The FreeBSD Foundation 5 * All rights reserved. 6 * 7 * This software was developed by Konstantin Belousov <kib@FreeBSD.org> 8 * under sponsorship from the FreeBSD Foundation. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 /* $Id: vm86_test.c,v 1.10 2018/05/12 11:35:58 kostik Exp kostik $ */ 35 36 #include <sys/param.h> 37 #include <sys/mman.h> 38 #include <sys/ucontext.h> 39 40 #include <machine/cpufunc.h> 41 #include <machine/psl.h> 42 #include <machine/sysarch.h> 43 #include <machine/vm86.h> 44 45 #include <err.h> 46 #include <signal.h> 47 #include <stdio.h> 48 #include <stdlib.h> 49 #include <string.h> 50 51 static u_int gs; 52 53 static void 54 sig_handler(int signo, siginfo_t *si __unused, void *ucp) 55 { 56 ucontext_t *uc; 57 mcontext_t *mc; 58 59 uc = ucp; 60 mc = &uc->uc_mcontext; 61 62 /* 63 * Reload pointer to the TLS base, so that malloc inside 64 * printf() works. 65 */ 66 load_gs(gs); 67 68 printf("sig %d %%eax %#x %%ecx %#x %%eip %#x\n", signo, 69 mc->mc_eax, mc->mc_ecx, mc->mc_eip); 70 exit(0); 71 } 72 73 extern char vm86_code_start[], vm86_code_end[]; 74 75 int 76 main(void) 77 { 78 ucontext_t uc; 79 struct sigaction sa; 80 struct vm86_init_args va; 81 stack_t ssa; 82 char *vm86_code; 83 84 gs = rgs(); 85 86 memset(&ssa, 0, sizeof(ssa)); 87 ssa.ss_size = PAGE_SIZE * 128; 88 ssa.ss_sp = mmap(NULL, ssa.ss_size, PROT_READ | PROT_WRITE | 89 PROT_EXEC, MAP_ANON, -1, 0); 90 if (ssa.ss_sp == MAP_FAILED) 91 err(1, "mmap sigstack"); 92 if (sigaltstack(&ssa, NULL) == -1) 93 err(1, "sigaltstack"); 94 95 memset(&sa, 0, sizeof(sa)); 96 sa.sa_sigaction = sig_handler; 97 sa.sa_flags = SA_SIGINFO | SA_ONSTACK; 98 if (sigaction(SIGBUS, &sa, NULL) == -1) 99 err(1, "sigaction SIGBUS"); 100 if (sigaction(SIGSEGV, &sa, NULL) == -1) 101 err(1, "sigaction SIGSEGV"); 102 if (sigaction(SIGILL, &sa, NULL) == -1) 103 err(1, "sigaction SIGILL"); 104 105 vm86_code = mmap((void *)0x10000, PAGE_SIZE, PROT_READ | PROT_WRITE | 106 PROT_EXEC, MAP_ANON | MAP_FIXED, -1, 0); 107 if (vm86_code == MAP_FAILED) 108 err(1, "mmap"); 109 memcpy(vm86_code, vm86_code_start, vm86_code_end - vm86_code_start); 110 111 memset(&va, 0, sizeof(va)); 112 if (i386_vm86(VM86_INIT, &va) == -1) 113 err(1, "VM86_INIT"); 114 115 memset(&uc, 0, sizeof(uc)); 116 uc.uc_mcontext.mc_ecx = 0x2345; 117 uc.uc_mcontext.mc_eflags = PSL_VM | PSL_USER; 118 uc.uc_mcontext.mc_cs = uc.uc_mcontext.mc_ds = uc.uc_mcontext.mc_es = 119 uc.uc_mcontext.mc_ss = (uintptr_t)vm86_code >> 4; 120 uc.uc_mcontext.mc_esp = 0xfffe; 121 sigreturn(&uc); 122 } 123