1 /* $NetBSD: sig_machdep.c,v 1.4 2003/01/17 23:36:18 thorpej 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: sig_machdep.c,v 1.4 2003/01/17 23:36:18 thorpej 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/sa.h> 70 #include <sys/syscallargs.h> 71 72 #include <machine/cpu.h> 73 74 #include <mips/regnum.h> 75 76 #ifdef DEBUG 77 int sigdebug = 0; 78 int sigpid = 0; 79 #define SDB_FOLLOW 0x01 80 #define SDB_KSTACK 0x02 81 #define SDB_FPSTATE 0x04 82 #endif 83 84 /* 85 * Send a signal to process. 86 */ 87 void 88 sendsig(int sig, sigset_t *returnmask, u_long code) 89 { 90 struct lwp *l = curlwp; 91 struct proc *p = l->l_proc; 92 struct sigacts *ps = p->p_sigacts; 93 struct sigcontext *scp, ksc; 94 struct frame *f; 95 int onstack; 96 sig_t catcher = SIGACTION(p, sig).sa_handler; 97 98 f = (struct frame *)l->l_md.md_regs; 99 100 /* Do we need to jump onto the signal stack? */ 101 onstack = 102 (p->p_sigctx.ps_sigstk.ss_flags & (SS_DISABLE | SS_ONSTACK)) == 0 && 103 (SIGACTION(p, sig).sa_flags & SA_ONSTACK) != 0; 104 105 /* Allocate space for the signal handler context. */ 106 if (onstack) 107 scp = (struct sigcontext *)((caddr_t)p->p_sigctx.ps_sigstk.ss_sp 108 + p->p_sigctx.ps_sigstk.ss_size); 109 else 110 /* cast for _MIPS_BSD_API == _MIPS_BSD_API_LP32_64CLEAN case */ 111 scp = (struct sigcontext *)(u_int32_t)f->f_regs[SP]; 112 scp--; 113 114 #ifdef DEBUG 115 if ((sigdebug & SDB_FOLLOW) || 116 ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid)) 117 printf("sendsig(%d): sig %d ssp %p scp %p\n", 118 p->p_pid, sig, &onstack, scp); 119 #endif 120 121 /* Build stack frame for signal trampoline. */ 122 ksc.sc_pc = f->f_regs[PC]; 123 ksc.mullo = f->f_regs[MULLO]; 124 ksc.mulhi = f->f_regs[MULHI]; 125 126 /* Save register context. */ 127 ksc.sc_regs[ZERO] = 0xACEDBADE; /* magic number */ 128 memcpy(&ksc.sc_regs[1], &f->f_regs[1], 129 sizeof(ksc.sc_regs) - sizeof(ksc.sc_regs[0])); 130 131 /* Save the FP state, if necessary, then copy it. */ 132 #ifndef SOFTFLOAT 133 ksc.sc_fpused = l->l_md.md_flags & MDP_FPUSED; 134 if (ksc.sc_fpused) { 135 /* if FPU has current state, save it first */ 136 if (l == fpcurlwp) 137 savefpregs(l); 138 *(struct fpreg *)ksc.sc_fpregs = l->l_addr->u_pcb.pcb_fpregs; 139 } 140 #else 141 *(struct fpreg *)ksc.sc_fpregs = l->l_addr->u_pcb.pcb_fpregs; 142 #endif 143 144 /* Save signal stack. */ 145 ksc.sc_onstack = p->p_sigctx.ps_sigstk.ss_flags & SS_ONSTACK; 146 147 /* Save signal mask. */ 148 ksc.sc_mask = *returnmask; 149 150 #if defined(COMPAT_13) || defined(COMPAT_ULTRIX) 151 /* 152 * XXX We always have to save an old style signal mask because 153 * XXX we might be delivering a signal to a process which will 154 * XXX escape from the signal in a non-standard way and invoke 155 * XXX sigreturn() directly. 156 */ 157 native_sigset_to_sigset13(returnmask, &ksc.__sc_mask13); 158 #endif 159 160 if (copyout(&ksc, (caddr_t)scp, sizeof(ksc))) { 161 /* 162 * Process has trashed its stack; give it an illegal 163 * instruction to halt it in its tracks. 164 */ 165 #ifdef DEBUG 166 if ((sigdebug & SDB_FOLLOW) || 167 ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid)) 168 printf("sendsig(%d): copyout failed on sig %d\n", 169 p->p_pid, sig); 170 #endif 171 sigexit(l, SIGILL); 172 /* NOTREACHED */ 173 } 174 175 /* 176 * Set up the registers to directly invoke the signal 177 * handler. The return address will be set up to point 178 * to the signal trampoline to bounce us back. 179 */ 180 f->f_regs[A0] = sig; 181 f->f_regs[A1] = code; 182 f->f_regs[A2] = (int)scp; 183 f->f_regs[A3] = (int)catcher; /* XXX ??? */ 184 185 f->f_regs[PC] = (int)catcher; 186 f->f_regs[T9] = (int)catcher; 187 f->f_regs[SP] = (int)scp; 188 189 switch (ps->sa_sigdesc[sig].sd_vers) { 190 #if 1 /* COMPAT_16 */ 191 case 0: /* legacy on-stack sigtramp */ 192 f->f_regs[RA] = (int)p->p_sigctx.ps_sigcode; 193 break; 194 #endif /* COMPAT_16 */ 195 196 case 1: 197 f->f_regs[RA] = (int)ps->sa_sigdesc[sig].sd_tramp; 198 break; 199 200 default: 201 /* Don't know what trampoline version; kill it. */ 202 sigexit(l, SIGILL); 203 } 204 205 /* Remember that we're now on the signal stack. */ 206 if (onstack) 207 p->p_sigctx.ps_sigstk.ss_flags |= SS_ONSTACK; 208 209 #ifdef DEBUG 210 if ((sigdebug & SDB_FOLLOW) || 211 ((sigdebug & SDB_KSTACK) && p->p_pid == sigpid)) 212 printf("sendsig(%d): sig %d returns\n", 213 p->p_pid, sig); 214 #endif 215 } 216 217 /* 218 * System call to cleanup state after a signal 219 * has been taken. Reset signal mask and 220 * stack state from context left by sendsig (above). 221 * Return to previous pc and psl as specified by 222 * context left by sendsig. Check carefully to 223 * make sure that the user has not modified the 224 * psl to gain improper privileges or to cause 225 * a machine fault. 226 */ 227 /* ARGSUSED */ 228 int 229 sys___sigreturn14(struct lwp *l, void *v, register_t *retval) 230 { 231 struct sys___sigreturn14_args /* { 232 syscallarg(struct sigcontext *) sigcntxp; 233 } */ *uap = v; 234 struct sigcontext *scp, ksc; 235 struct frame *f; 236 struct proc *p = l->l_proc; 237 int error; 238 239 /* 240 * The trampoline code hands us the context. 241 * It is unsafe to keep track of it ourselves, in the event that a 242 * program jumps out of a signal handler. 243 */ 244 scp = SCARG(uap, sigcntxp); 245 #ifdef DEBUG 246 if (sigdebug & SDB_FOLLOW) 247 printf("sigreturn: pid %d, scp %p\n", l->l_proc->p_pid, scp); 248 #endif 249 if ((error = copyin(scp, &ksc, sizeof(ksc))) != 0) 250 return (error); 251 252 if ((u_int) ksc.sc_regs[ZERO] != 0xacedbadeU) /* magic number */ 253 return (EINVAL); 254 255 /* Restore the register context. */ 256 f = (struct frame *)l->l_md.md_regs; 257 f->f_regs[PC] = ksc.sc_pc; 258 f->f_regs[MULLO] = ksc.mullo; 259 f->f_regs[MULHI] = ksc.mulhi; 260 memcpy(&f->f_regs[1], &scp->sc_regs[1], 261 sizeof(scp->sc_regs) - sizeof(scp->sc_regs[0])); 262 #ifndef SOFTFLOAT 263 if (scp->sc_fpused) { 264 /* Disable the FPU to fault in FP registers. */ 265 f->f_regs[SR] &= ~MIPS_SR_COP_1_BIT; 266 if (l == fpcurlwp) { 267 fpcurlwp = (struct lwp *)0; 268 } 269 l->l_addr->u_pcb.pcb_fpregs = *(struct fpreg *)scp->sc_fpregs; 270 } 271 #else 272 l->l_addr->u_pcb.pcb_fpregs = *(struct fpreg *)scp->sc_fpregs; 273 #endif 274 275 /* Restore signal stack. */ 276 if (ksc.sc_onstack & SS_ONSTACK) 277 p->p_sigctx.ps_sigstk.ss_flags |= SS_ONSTACK; 278 else 279 p->p_sigctx.ps_sigstk.ss_flags &= ~SS_ONSTACK; 280 281 /* Restore signal mask. */ 282 (void) sigprocmask1(p, SIG_SETMASK, &ksc.sc_mask, 0); 283 284 return (EJUSTRETURN); 285 } 286