1 /* $NetBSD: compat_13_machdep.c,v 1.7 2001/11/15 07:03:29 lukem Exp $ */ 2 3 /*- 4 * Copyright (c) 1996, 1997, 1998, 2000 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Charles M. Hannum. 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 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 __KERNEL_RCSID(0, "$NetBSD: compat_13_machdep.c,v 1.7 2001/11/15 07:03:29 lukem Exp $"); 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/signalvar.h> 45 #include <sys/kernel.h> 46 #include <sys/map.h> 47 #include <sys/proc.h> 48 #include <sys/user.h> 49 #include <sys/mount.h> 50 #include <sys/syscallargs.h> 51 52 #ifdef VM86 53 #include <machine/vm86.h> 54 #endif 55 56 int 57 compat_13_sys_sigreturn(p, v, retval) 58 struct proc *p; 59 void *v; 60 register_t *retval; 61 { 62 struct compat_13_sys_sigreturn_args /* { 63 syscallarg(struct sigcontext13 *) sigcntxp; 64 } */ *uap = v; 65 struct sigcontext13 *scp, context; 66 struct trapframe *tf; 67 sigset_t mask; 68 69 /* 70 * The trampoline code hands us the context. 71 * It is unsafe to keep track of it ourselves, in the event that a 72 * program jumps out of a signal handler. 73 */ 74 scp = SCARG(uap, sigcntxp); 75 if (copyin((caddr_t)scp, &context, sizeof(*scp)) != 0) 76 return (EFAULT); 77 78 /* Restore register context. */ 79 tf = p->p_md.md_regs; 80 #ifdef VM86 81 if (context.sc_eflags & PSL_VM) { 82 void syscall_vm86 __P((struct trapframe)); 83 84 tf->tf_vm86_gs = context.sc_gs; 85 tf->tf_vm86_fs = context.sc_fs; 86 tf->tf_vm86_es = context.sc_es; 87 tf->tf_vm86_ds = context.sc_ds; 88 set_vflags(p, context.sc_eflags); 89 p->p_md.md_syscall = syscall_vm86; 90 } else 91 #endif 92 { 93 /* 94 * Check for security violations. If we're returning to 95 * protected mode, the CPU will validate the segment registers 96 * automatically and generate a trap on violations. We handle 97 * the trap, rather than doing all of the checking here. 98 */ 99 if (((context.sc_eflags ^ tf->tf_eflags) & PSL_USERSTATIC) != 0 || 100 !USERMODE(context.sc_cs, context.sc_eflags)) 101 return (EINVAL); 102 103 tf->tf_gs = context.sc_gs; 104 tf->tf_fs = context.sc_fs; 105 tf->tf_es = context.sc_es; 106 tf->tf_ds = context.sc_ds; 107 tf->tf_eflags = context.sc_eflags; 108 } 109 tf->tf_edi = context.sc_edi; 110 tf->tf_esi = context.sc_esi; 111 tf->tf_ebp = context.sc_ebp; 112 tf->tf_ebx = context.sc_ebx; 113 tf->tf_edx = context.sc_edx; 114 tf->tf_ecx = context.sc_ecx; 115 tf->tf_eax = context.sc_eax; 116 tf->tf_eip = context.sc_eip; 117 tf->tf_cs = context.sc_cs; 118 tf->tf_esp = context.sc_esp; 119 tf->tf_ss = context.sc_ss; 120 121 /* Restore signal stack. */ 122 if (context.sc_onstack & SS_ONSTACK) 123 p->p_sigctx.ps_sigstk.ss_flags |= SS_ONSTACK; 124 else 125 p->p_sigctx.ps_sigstk.ss_flags &= ~SS_ONSTACK; 126 127 /* Restore signal mask. */ 128 native_sigset13_to_sigset(&context.sc_mask, &mask); 129 (void) sigprocmask1(p, SIG_SETMASK, &mask, 0); 130 131 return (EJUSTRETURN); 132 } 133