1 /* $NetBSD: sig_machdep.c,v 1.23 2011/07/10 23:21:59 matt Exp $ */ 2 3 /*- 4 * Copyright (c) 2003 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Christos Zoulas. 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> /* RCS ID & Copyright macro defns */ 33 34 __KERNEL_RCSID(0, "$NetBSD: sig_machdep.c,v 1.23 2011/07/10 23:21:59 matt Exp $"); 35 36 #include "opt_cputype.h" 37 38 #include <sys/param.h> 39 #include <sys/cpu.h> 40 #include <sys/kernel.h> 41 #include <sys/proc.h> 42 #include <sys/signal.h> 43 #include <sys/signalvar.h> 44 #include <sys/mount.h> 45 #include <sys/syscallargs.h> 46 47 #include <mips/frame.h> 48 #include <mips/regnum.h> 49 #include <mips/locore.h> 50 51 void * 52 getframe(struct lwp *l, int sig, int *onstack) 53 { 54 struct proc * const p = l->l_proc; 55 struct trapframe * const tf = l->l_md.md_utf; 56 57 /* Do we need to jump onto the signal stack? */ 58 *onstack = (l->l_sigstk.ss_flags & (SS_DISABLE | SS_ONSTACK)) == 0 59 && (SIGACTION(p, sig).sa_flags & SA_ONSTACK) != 0; 60 if (*onstack) 61 return (char *)l->l_sigstk.ss_sp + l->l_sigstk.ss_size; 62 return (void *)(intptr_t)tf->tf_regs[_R_SP]; 63 } 64 65 struct sigframe_siginfo { 66 siginfo_t sf_si; 67 ucontext_t sf_uc; 68 }; 69 70 /* 71 * Send a signal to process. 72 */ 73 void 74 sendsig_siginfo(const ksiginfo_t *ksi, const sigset_t *mask) 75 { 76 struct lwp * const l = curlwp; 77 struct proc * const p = l->l_proc; 78 struct sigacts * const sa = p->p_sigacts; 79 struct trapframe * const tf = l->l_md.md_utf; 80 int onstack, error; 81 const int signo = ksi->ksi_signo; 82 struct sigframe_siginfo *sf = getframe(l, signo, &onstack); 83 struct sigframe_siginfo ksf; 84 const sig_t catcher = SIGACTION(p, signo).sa_handler; 85 86 sf--; 87 88 ksf.sf_si._info = ksi->ksi_info; 89 ksf.sf_uc.uc_flags = _UC_SIGMASK 90 | (l->l_sigstk.ss_flags & SS_ONSTACK ? _UC_SETSTACK : _UC_CLRSTACK); 91 ksf.sf_uc.uc_sigmask = *mask; 92 ksf.sf_uc.uc_link = l->l_ctxlink; 93 memset(&ksf.sf_uc.uc_stack, 0, sizeof(ksf.sf_uc.uc_stack)); 94 sendsig_reset(l, signo); 95 96 mutex_exit(p->p_lock); 97 cpu_getmcontext(l, &ksf.sf_uc.uc_mcontext, &ksf.sf_uc.uc_flags); 98 error = copyout(&ksf, sf, sizeof(ksf)); 99 mutex_enter(p->p_lock); 100 101 if (error != 0) { 102 /* 103 * Process has trashed its stack; give it an illegal 104 * instruction to halt it in its tracks. 105 */ 106 sigexit(l, SIGILL); 107 /* NOTREACHED */ 108 } 109 110 /* 111 * Set up the registers to directly invoke the signal 112 * handler. The return address will be set up to point 113 * to the signal trampoline to bounce us back. 114 */ 115 tf->tf_regs[_R_A0] = signo; 116 tf->tf_regs[_R_A1] = (intptr_t)&sf->sf_si; 117 tf->tf_regs[_R_A2] = (intptr_t)&sf->sf_uc; 118 119 tf->tf_regs[_R_PC] = (intptr_t)catcher; 120 tf->tf_regs[_R_T9] = (intptr_t)catcher; 121 tf->tf_regs[_R_SP] = (intptr_t)sf; 122 tf->tf_regs[_R_RA] = (intptr_t)sa->sa_sigdesc[signo].sd_tramp; 123 124 /* Remember that we're now on the signal stack. */ 125 if (onstack) 126 l->l_sigstk.ss_flags |= SS_ONSTACK; 127 } 128