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 /* $Id: vm86_test.c,v 1.10 2018/05/12 11:35:58 kostik Exp kostik $ */ 34 35 #include <sys/param.h> 36 #include <sys/mman.h> 37 #include <sys/ucontext.h> 38 39 #include <machine/cpufunc.h> 40 #include <machine/psl.h> 41 #include <machine/sysarch.h> 42 #include <machine/vm86.h> 43 44 #include <err.h> 45 #include <signal.h> 46 #include <stdio.h> 47 #include <stdlib.h> 48 #include <string.h> 49 50 static u_int gs; 51 52 static void 53 sig_handler(int signo, siginfo_t *si __unused, void *ucp) 54 { 55 ucontext_t *uc; 56 mcontext_t *mc; 57 58 uc = ucp; 59 mc = &uc->uc_mcontext; 60 61 /* 62 * Reload pointer to the TLS base, so that malloc inside 63 * printf() works. 64 */ 65 load_gs(gs); 66 67 printf("sig %d %%eax %#x %%ecx %#x %%eip %#x\n", signo, 68 mc->mc_eax, mc->mc_ecx, mc->mc_eip); 69 exit(0); 70 } 71 72 extern char vm86_code_start[], vm86_code_end[]; 73 74 int 75 main(void) 76 { 77 ucontext_t uc; 78 struct sigaction sa; 79 struct vm86_init_args va; 80 stack_t ssa; 81 char *vm86_code; 82 83 gs = rgs(); 84 85 memset(&ssa, 0, sizeof(ssa)); 86 ssa.ss_size = PAGE_SIZE * 128; 87 ssa.ss_sp = mmap(NULL, ssa.ss_size, PROT_READ | PROT_WRITE | 88 PROT_EXEC, MAP_ANON, -1, 0); 89 if (ssa.ss_sp == MAP_FAILED) 90 err(1, "mmap sigstack"); 91 if (sigaltstack(&ssa, NULL) == -1) 92 err(1, "sigaltstack"); 93 94 memset(&sa, 0, sizeof(sa)); 95 sa.sa_sigaction = sig_handler; 96 sa.sa_flags = SA_SIGINFO | SA_ONSTACK; 97 if (sigaction(SIGBUS, &sa, NULL) == -1) 98 err(1, "sigaction SIGBUS"); 99 if (sigaction(SIGSEGV, &sa, NULL) == -1) 100 err(1, "sigaction SIGSEGV"); 101 if (sigaction(SIGILL, &sa, NULL) == -1) 102 err(1, "sigaction SIGILL"); 103 104 vm86_code = mmap((void *)0x10000, PAGE_SIZE, PROT_READ | PROT_WRITE | 105 PROT_EXEC, MAP_ANON | MAP_FIXED, -1, 0); 106 if (vm86_code == MAP_FAILED) 107 err(1, "mmap"); 108 memcpy(vm86_code, vm86_code_start, vm86_code_end - vm86_code_start); 109 110 memset(&va, 0, sizeof(va)); 111 if (i386_vm86(VM86_INIT, &va) == -1) 112 err(1, "VM86_INIT"); 113 114 memset(&uc, 0, sizeof(uc)); 115 uc.uc_mcontext.mc_ecx = 0x2345; 116 uc.uc_mcontext.mc_eflags = PSL_VM | PSL_USER; 117 uc.uc_mcontext.mc_cs = uc.uc_mcontext.mc_ds = uc.uc_mcontext.mc_es = 118 uc.uc_mcontext.mc_ss = (uintptr_t)vm86_code >> 4; 119 uc.uc_mcontext.mc_esp = 0xfffe; 120 sigreturn(&uc); 121 } 122