1 /* $NetBSD: compat_16_machdep.c,v 1.9 2007/03/04 06:00:12 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 1998, 2001 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, 9 * NASA Ames Research Center and by Chris Demetriou. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the NetBSD 22 * Foundation, Inc. and its contributors. 23 * 4. Neither the name of The NetBSD Foundation nor the names of its 24 * contributors may be used to endorse or promote products derived 25 * from this software without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 37 * POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40 /* 41 * Copyright 1996 The Board of Trustees of The Leland Stanford 42 * Junior University. All Rights Reserved. 43 * 44 * Permission to use, copy, modify, and distribute this 45 * software and its documentation for any purpose and without 46 * fee is hereby granted, provided that the above copyright 47 * notice appear in all copies. Stanford University 48 * makes no representations about the suitability of this 49 * software for any purpose. It is provided "as is" without 50 * express or implied warranty. 51 */ 52 53 #include <sys/cdefs.h> /* RCS ID & Copyright macro defns */ 54 55 __KERNEL_RCSID(0, "$NetBSD: compat_16_machdep.c,v 1.9 2007/03/04 06:00:12 christos Exp $"); 56 57 #include "opt_cputype.h" 58 #include "opt_compat_netbsd.h" 59 #include "opt_compat_ultrix.h" 60 61 #include <sys/param.h> 62 #include <sys/systm.h> 63 #include <sys/kernel.h> 64 #include <sys/proc.h> 65 #include <sys/user.h> 66 #include <sys/signal.h> 67 #include <sys/signalvar.h> 68 #include <sys/mount.h> 69 #include <sys/syscallargs.h> 70 71 #include <compat/sys/signal.h> 72 #include <compat/sys/signalvar.h> 73 74 #include <machine/cpu.h> 75 76 #include <mips/regnum.h> 77 #include <mips/frame.h> 78 79 #ifdef DEBUG 80 int sigdebug = 0; 81 int sigpid = 0; 82 #define SDB_FOLLOW 0x01 83 #define SDB_KSTACK 0x02 84 #define SDB_FPSTATE 0x04 85 #endif 86 87 /* 88 * Send a signal to process. 89 */ 90 void 91 sendsig_sigcontext(const ksiginfo_t *ksi, const sigset_t *returnmask) 92 { 93 int sig = ksi->ksi_signo; 94 struct lwp *l = curlwp; 95 struct proc *p = l->l_proc; 96 struct sigacts *ps = p->p_sigacts; 97 int onstack, error; 98 struct sigcontext *scp = getframe(l, sig, &onstack), ksc; 99 struct frame *f; 100 sig_t catcher = SIGACTION(p, sig).sa_handler; 101 102 f = (struct frame *)l->l_md.md_regs; 103 104 scp--; 105 106 #ifdef DEBUG 107 if ((sigdebug & SDB_FOLLOW) || 108 ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid)) 109 printf("sendsig(%d): sig %d ssp %p scp %p\n", 110 p->p_pid, sig, &onstack, scp); 111 #endif 112 113 /* Build stack frame for signal trampoline. */ 114 ksc.sc_pc = f->f_regs[_R_PC]; 115 ksc.mullo = f->f_regs[_R_MULLO]; 116 ksc.mulhi = f->f_regs[_R_MULHI]; 117 118 /* Save register context. */ 119 ksc.sc_regs[_R_ZERO] = 0xACEDBADE; /* magic number */ 120 memcpy(&ksc.sc_regs[1], &f->f_regs[1], 121 sizeof(ksc.sc_regs) - sizeof(ksc.sc_regs[0])); 122 123 /* Save the FP state, if necessary, then copy it. */ 124 #ifndef SOFTFLOAT 125 ksc.sc_fpused = l->l_md.md_flags & MDP_FPUSED; 126 if (ksc.sc_fpused) { 127 /* if FPU has current state, save it first */ 128 if (l == fpcurlwp) 129 savefpregs(l); 130 *(struct fpreg *)ksc.sc_fpregs = l->l_addr->u_pcb.pcb_fpregs; 131 } 132 #else 133 *(struct fpreg *)ksc.sc_fpregs = l->l_addr->u_pcb.pcb_fpregs; 134 #endif 135 136 /* Save signal stack. */ 137 ksc.sc_onstack = l->l_sigstk.ss_flags & SS_ONSTACK; 138 139 /* Save signal mask. */ 140 ksc.sc_mask = *returnmask; 141 142 #if defined(COMPAT_13) || defined(COMPAT_ULTRIX) 143 /* 144 * XXX We always have to save an old style signal mask because 145 * XXX we might be delivering a signal to a process which will 146 * XXX escape from the signal in a non-standard way and invoke 147 * XXX sigreturn() directly. 148 */ 149 native_sigset_to_sigset13(returnmask, &ksc.__sc_mask13); 150 #endif 151 152 sendsig_reset(l, sig); 153 154 mutex_exit(&p->p_smutex); 155 error = copyout(&ksc, (void *)scp, sizeof(ksc)); 156 mutex_enter(&p->p_smutex); 157 158 if (error != 0) { 159 /* 160 * Process has trashed its stack; give it an illegal 161 * instruction to halt it in its tracks. 162 */ 163 #ifdef DEBUG 164 if ((sigdebug & SDB_FOLLOW) || 165 ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid)) 166 printf("sendsig(%d): copyout failed on sig %d\n", 167 p->p_pid, sig); 168 #endif 169 sigexit(l, SIGILL); 170 /* NOTREACHED */ 171 } 172 173 /* 174 * Set up the registers to directly invoke the signal 175 * handler. The return address will be set up to point 176 * to the signal trampoline to bounce us back. 177 */ 178 f->f_regs[_R_A0] = sig; 179 f->f_regs[_R_A1] = ksi->ksi_trap; 180 f->f_regs[_R_A2] = (intptr_t)scp; 181 f->f_regs[_R_A3] = (intptr_t)catcher; /* XXX ??? */ 182 183 f->f_regs[_R_PC] = (intptr_t)catcher; 184 f->f_regs[_R_T9] = (intptr_t)catcher; 185 f->f_regs[_R_SP] = (intptr_t)scp; 186 187 switch (ps->sa_sigdesc[sig].sd_vers) { 188 case 0: /* legacy on-stack sigtramp */ 189 f->f_regs[_R_RA] = (intptr_t)p->p_sigctx.ps_sigcode; 190 break; 191 #ifdef COMPAT_16 192 case 1: 193 f->f_regs[_R_RA] = (intptr_t)ps->sa_sigdesc[sig].sd_tramp; 194 break; 195 #endif 196 default: 197 /* Don't know what trampoline version; kill it. */ 198 sigexit(l, SIGILL); 199 } 200 201 /* Remember that we're now on the signal stack. */ 202 if (onstack) 203 l->l_sigstk.ss_flags |= SS_ONSTACK; 204 205 #ifdef DEBUG 206 if ((sigdebug & SDB_FOLLOW) || 207 ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid)) 208 printf("sendsig(%d): sig %d returns\n", 209 p->p_pid, sig); 210 #endif 211 } 212 213 #ifdef COMPAT_16 /* not needed if COMPAT_ULTRIX only */ 214 /* 215 * System call to cleanup state after a signal 216 * has been taken. Reset signal mask and 217 * stack state from context left by sendsig (above). 218 * Return to previous pc and psl as specified by 219 * context left by sendsig. Check carefully to 220 * make sure that the user has not modified the 221 * psl to gain improper privileges or to cause 222 * a machine fault. 223 */ 224 /* ARGSUSED */ 225 int 226 compat_16_sys___sigreturn14(struct lwp *l, void *v, register_t *retval) 227 { 228 struct compat_16_sys___sigreturn14_args /* { 229 syscallarg(struct sigcontext *) sigcntxp; 230 } */ *uap = v; 231 struct sigcontext *scp, ksc; 232 struct frame *f; 233 struct proc *p = l->l_proc; 234 int error; 235 236 /* 237 * The trampoline code hands us the context. 238 * It is unsafe to keep track of it ourselves, in the event that a 239 * program jumps out of a signal handler. 240 */ 241 scp = SCARG(uap, sigcntxp); 242 #ifdef DEBUG 243 if (sigdebug & SDB_FOLLOW) 244 printf("sigreturn: pid %d, scp %p\n", l->l_proc->p_pid, scp); 245 #endif 246 if ((error = copyin(scp, &ksc, sizeof(ksc))) != 0) 247 return (error); 248 249 if ((u_int) ksc.sc_regs[_R_ZERO] != 0xacedbadeU)/* magic number */ 250 return (EINVAL); 251 252 /* Restore the register context. */ 253 f = (struct frame *)l->l_md.md_regs; 254 f->f_regs[_R_PC] = ksc.sc_pc; 255 f->f_regs[_R_MULLO] = ksc.mullo; 256 f->f_regs[_R_MULHI] = ksc.mulhi; 257 memcpy(&f->f_regs[1], &scp->sc_regs[1], 258 sizeof(scp->sc_regs) - sizeof(scp->sc_regs[0])); 259 #ifndef SOFTFLOAT 260 if (scp->sc_fpused) { 261 /* Disable the FPU to fault in FP registers. */ 262 f->f_regs[_R_SR] &= ~MIPS_SR_COP_1_BIT; 263 if (l == fpcurlwp) 264 fpcurlwp = NULL; 265 l->l_addr->u_pcb.pcb_fpregs = *(struct fpreg *)scp->sc_fpregs; 266 } 267 #else 268 l->l_addr->u_pcb.pcb_fpregs = *(struct fpreg *)scp->sc_fpregs; 269 #endif 270 271 mutex_enter(&p->p_smutex); 272 /* Restore signal stack. */ 273 if (ksc.sc_onstack & SS_ONSTACK) 274 l->l_sigstk.ss_flags |= SS_ONSTACK; 275 else 276 l->l_sigstk.ss_flags &= ~SS_ONSTACK; 277 /* Restore signal mask. */ 278 (void) sigprocmask1(l, SIG_SETMASK, &ksc.sc_mask, 0); 279 mutex_exit(&p->p_smutex); 280 281 return (EJUSTRETURN); 282 } 283 #endif /* COMPAT_16 */ 284