1 2 /* 3 * Copyright (c) 2006 The DragonFly Project. All rights reserved. 4 * 5 * This code is derived from software contributed to The DragonFly Project 6 * by Matthew Dillon <dillon@backplane.com> 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in 16 * the documentation and/or other materials provided with the 17 * distribution. 18 * 3. Neither the name of The DragonFly Project nor the names of its 19 * contributors may be used to endorse or promote products derived 20 * from this software without specific, prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 25 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 26 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 27 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 28 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 29 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 30 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 31 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 32 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include "opt_ddb.h" 37 #include <sys/types.h> 38 #include <sys/systm.h> 39 #include <sys/reboot.h> 40 #include <sys/kernel.h> 41 #include <sys/kthread.h> 42 #include <ddb/ddb.h> 43 44 #include <sys/thread2.h> 45 46 #include <machine/trap.h> 47 #include <machine/md_var.h> 48 #include <machine/segments.h> 49 #include <machine/cpu.h> 50 #include <machine/smp.h> 51 52 #include <err.h> 53 #include <signal.h> 54 #include <stdio.h> 55 #include <unistd.h> 56 57 int _ucodesel = GSEL(GUCODE_SEL, SEL_UPL); 58 int _udatasel = GSEL(GUDATA_SEL, SEL_UPL); 59 60 static void exc_segfault(int signo, siginfo_t *info, void *ctx); 61 #ifdef DDB 62 static void exc_debugger(int signo, siginfo_t *info, void *ctx); 63 #endif 64 65 /* 66 * IPIs are 'fast' interrupts, so we deal with them directly from our 67 * signal handler. 68 * 69 * WARNING: Signals are not physically disabled here so we have to enter 70 * our critical section before bumping gd_intr_nesting_level or another 71 * interrupt can come along and get really confused. 72 */ 73 static 74 void 75 ipisig(int nada, siginfo_t *info, void *ctxp) 76 { 77 globaldata_t gd = mycpu; 78 thread_t td = gd->gd_curthread; 79 80 if (td->td_critcount == 0) { 81 ++td->td_critcount; 82 ++gd->gd_intr_nesting_level; 83 atomic_swap_int(&gd->gd_npoll, 0); 84 lwkt_process_ipiq(); 85 --gd->gd_intr_nesting_level; 86 --td->td_critcount; 87 } else { 88 need_ipiq(); 89 } 90 } 91 92 /* 93 * Unconditionally stop or restart a cpu. 94 * 95 * Note: cpu_mask_all_signals() masks all signals except SIGXCPU itself. 96 * SIGXCPU itself is blocked on entry to stopsig() by the signal handler 97 * itself. 98 * 99 * WARNING: Signals are not physically disabled here so we have to enter 100 * our critical section before bumping gd_intr_nesting_level or another 101 * interrupt can come along and get really confused. 102 */ 103 static 104 void 105 stopsig(int nada, siginfo_t *info, void *ctxp) 106 { 107 globaldata_t gd = mycpu; 108 thread_t td = gd->gd_curthread; 109 sigset_t ss; 110 111 sigemptyset(&ss); 112 sigaddset(&ss, SIGALRM); 113 sigaddset(&ss, SIGIO); 114 sigaddset(&ss, SIGQUIT); 115 sigaddset(&ss, SIGUSR1); 116 sigaddset(&ss, SIGUSR2); 117 sigaddset(&ss, SIGTERM); 118 sigaddset(&ss, SIGWINCH); 119 120 ++td->td_critcount; 121 ++gd->gd_intr_nesting_level; 122 while (CPUMASK_TESTMASK(stopped_cpus, gd->gd_cpumask)) { 123 sigsuspend(&ss); 124 } 125 --gd->gd_intr_nesting_level; 126 --td->td_critcount; 127 } 128 129 #if 0 130 131 /* 132 * SIGIO is used by cothreads to signal back into the virtual kernel. 133 */ 134 static 135 void 136 iosig(int nada, siginfo_t *info, void *ctxp) 137 { 138 signalintr(4); 139 } 140 141 #endif 142 143 static 144 void 145 infosig(int nada, siginfo_t *info, void *ctxp) 146 { 147 ucontext_t *ctx = ctxp; 148 char buf[256]; 149 150 snprintf(buf, sizeof(buf), "lwp %d pc=%p sp=%p\n", 151 (int)lwp_gettid(), 152 (void *)(intptr_t)ctx->uc_mcontext.mc_rip, 153 (void *)(intptr_t)ctx->uc_mcontext.mc_rsp); 154 write(2, buf, strlen(buf)); 155 } 156 157 void 158 init_exceptions(void) 159 { 160 struct sigaction sa; 161 162 bzero(&sa, sizeof(sa)); 163 sa.sa_sigaction = exc_segfault; 164 sa.sa_flags |= SA_SIGINFO | SA_NODEFER; 165 sigemptyset(&sa.sa_mask); 166 sigaction(SIGBUS, &sa, NULL); 167 sigaction(SIGSEGV, &sa, NULL); 168 sigaction(SIGTRAP, &sa, NULL); 169 sigaction(SIGFPE, &sa, NULL); 170 171 sa.sa_flags &= ~SA_NODEFER; 172 173 #ifdef DDB 174 sa.sa_sigaction = exc_debugger; 175 sigaction(SIGQUIT, &sa, NULL); 176 #endif 177 sa.sa_sigaction = ipisig; 178 sigaction(SIGUSR1, &sa, NULL); 179 sa.sa_sigaction = stopsig; 180 sigaction(SIGXCPU, &sa, NULL); 181 #if 0 182 sa.sa_sigaction = iosig; 183 sigaction(SIGIO, &sa, NULL); 184 #endif 185 sa.sa_sigaction = infosig; 186 sigaction(SIGINFO, &sa, NULL); 187 } 188 189 /* 190 * This function handles a segmentation fault. 191 * 192 * XXX We assume that trapframe is a subset of ucontext. It is as of 193 * this writing. 194 */ 195 static void 196 exc_segfault(int signo, siginfo_t *info, void *ctxp) 197 { 198 ucontext_t *ctx = ctxp; 199 200 #if 0 201 kprintf("CAUGHT SIG %d RIP %08lx ERR %08lx TRAPNO %ld " 202 "err %ld addr %08lx\n", 203 signo, 204 ctx->uc_mcontext.mc_rip, 205 ctx->uc_mcontext.mc_err, 206 ctx->uc_mcontext.mc_trapno & 0xFFFF, 207 ctx->uc_mcontext.mc_trapno >> 16, 208 ctx->uc_mcontext.mc_addr); 209 #endif 210 kern_trap((struct trapframe *)&ctx->uc_mcontext.mc_rdi); 211 splz(); 212 } 213 214 #ifdef DDB 215 216 static void 217 exc_debugger(int signo, siginfo_t *info, void *ctxp) 218 { 219 ucontext_t *ctx = ctxp; 220 221 kprintf("CAUGHT SIG %d RIP %08lx RSP %08lx TD %p\n", 222 signo, 223 ctx->uc_mcontext.mc_rip, 224 ctx->uc_mcontext.mc_rsp, 225 curthread); 226 Debugger("interrupt from console"); 227 } 228 229 #endif 230