1 /* $NetBSD: compat_13_machdep.c,v 1.25 2009/11/21 03:11:00 rmind 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 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 __KERNEL_RCSID(0, "$NetBSD: compat_13_machdep.c,v 1.25 2009/11/21 03:11:00 rmind Exp $"); 34 35 #ifdef _KERNEL_OPT 36 #include "opt_vm86.h" 37 #endif 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/signalvar.h> 42 #include <sys/kernel.h> 43 #include <sys/proc.h> 44 #include <sys/mount.h> 45 #include <sys/syscallargs.h> 46 47 #include <compat/sys/signal.h> 48 #include <compat/sys/signalvar.h> 49 50 #ifdef VM86 51 #include <machine/vm86.h> 52 #endif 53 54 int 55 compat_13_sys_sigreturn(struct lwp *l, const struct compat_13_sys_sigreturn_args *uap, register_t *retval) 56 { 57 /* { 58 syscallarg(struct sigcontext13 *) sigcntxp; 59 } */ 60 struct proc *p = l->l_proc; 61 struct sigcontext13 *scp, context; 62 struct trapframe *tf; 63 sigset_t mask; 64 65 /* 66 * The trampoline code hands us the context. 67 * It is unsafe to keep track of it ourselves, in the event that a 68 * program jumps out of a signal handler. 69 */ 70 scp = SCARG(uap, sigcntxp); 71 if (copyin((void *)scp, &context, sizeof(*scp)) != 0) 72 return (EFAULT); 73 74 /* Restore register context. */ 75 tf = l->l_md.md_regs; 76 #ifdef VM86 77 if (context.sc_eflags & PSL_VM) { 78 void syscall_vm86(struct trapframe *); 79 80 tf->tf_vm86_gs = context.sc_gs; 81 tf->tf_vm86_fs = context.sc_fs; 82 tf->tf_vm86_es = context.sc_es; 83 tf->tf_vm86_ds = context.sc_ds; 84 set_vflags(l, context.sc_eflags); 85 p->p_md.md_syscall = syscall_vm86; 86 } else 87 #endif 88 { 89 /* 90 * Check for security violations. If we're returning to 91 * protected mode, the CPU will validate the segment registers 92 * automatically and generate a trap on violations. We handle 93 * the trap, rather than doing all of the checking here. 94 */ 95 if (((context.sc_eflags ^ tf->tf_eflags) & PSL_USERSTATIC) != 0 || 96 !USERMODE(context.sc_cs, context.sc_eflags)) 97 return (EINVAL); 98 99 tf->tf_gs = context.sc_gs; 100 tf->tf_fs = context.sc_fs; 101 tf->tf_es = context.sc_es; 102 tf->tf_ds = context.sc_ds; 103 tf->tf_eflags &= ~PSL_USER; 104 tf->tf_eflags |= context.sc_eflags & PSL_USER; 105 } 106 tf->tf_edi = context.sc_edi; 107 tf->tf_esi = context.sc_esi; 108 tf->tf_ebp = context.sc_ebp; 109 tf->tf_ebx = context.sc_ebx; 110 tf->tf_edx = context.sc_edx; 111 tf->tf_ecx = context.sc_ecx; 112 tf->tf_eax = context.sc_eax; 113 tf->tf_eip = context.sc_eip; 114 tf->tf_cs = context.sc_cs; 115 tf->tf_esp = context.sc_esp; 116 tf->tf_ss = context.sc_ss; 117 118 mutex_enter(p->p_lock); 119 /* Restore signal stack. */ 120 if (context.sc_onstack & SS_ONSTACK) 121 l->l_sigstk.ss_flags |= SS_ONSTACK; 122 else 123 l->l_sigstk.ss_flags &= ~SS_ONSTACK; 124 /* Restore signal mask. */ 125 native_sigset13_to_sigset(&context.sc_mask, &mask); 126 (void) sigprocmask1(l, SIG_SETMASK, &mask, 0); 127 mutex_exit(p->p_lock); 128 129 return (EJUSTRETURN); 130 } 131