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 #include <sys/lwp.h> 46 47 #include <machine/trap.h> 48 #include <machine/md_var.h> 49 #include <machine/segments.h> 50 #include <machine/cpu.h> 51 #include <machine/smp.h> 52 53 #include <err.h> 54 #include <signal.h> 55 #include <stdio.h> 56 #include <unistd.h> 57 58 int _ucodesel = GSEL(GUCODE_SEL, SEL_UPL); 59 int _udatasel = GSEL(GUDATA_SEL, SEL_UPL); 60 61 static void exc_segfault(int signo, siginfo_t *info, void *ctx); 62 #ifdef DDB 63 static void exc_debugger(int signo, siginfo_t *info, void *ctx); 64 #endif 65 66 /* 67 * IPIs are 'fast' interrupts, so we deal with them directly from our 68 * signal handler. 69 * 70 * WARNING: Signals are not physically disabled here so we have to enter 71 * our critical section before bumping gd_intr_nesting_level or another 72 * interrupt can come along and get really confused. 73 */ 74 static 75 void 76 ipisig(int nada, siginfo_t *info, void *ctxp) 77 { 78 globaldata_t gd = mycpu; 79 thread_t td = gd->gd_curthread; 80 81 if (td->td_critcount == 0) { 82 ++td->td_critcount; 83 ++gd->gd_cnt.v_ipi; 84 ++gd->gd_intr_nesting_level; 85 atomic_swap_int(&gd->gd_npoll, 0); 86 lwkt_process_ipiq(); 87 --gd->gd_intr_nesting_level; 88 --td->td_critcount; 89 } else { 90 need_ipiq(); 91 } 92 } 93 94 /* 95 * Unconditionally stop or restart a cpu. 96 * 97 * Note: cpu_mask_all_signals() masks all signals except SIGXCPU itself. 98 * SIGXCPU itself is blocked on entry to stopsig() by the signal handler 99 * itself. 100 * 101 * WARNING: Signals are not physically disabled here so we have to enter 102 * our critical section before bumping gd_intr_nesting_level or another 103 * interrupt can come along and get really confused. 104 */ 105 static 106 void 107 stopsig(int nada, siginfo_t *info, void *ctxp) 108 { 109 globaldata_t gd = mycpu; 110 thread_t td = gd->gd_curthread; 111 sigset_t ss; 112 113 sigemptyset(&ss); 114 sigaddset(&ss, SIGALRM); 115 sigaddset(&ss, SIGIO); 116 sigaddset(&ss, SIGURG); 117 sigaddset(&ss, SIGQUIT); 118 sigaddset(&ss, SIGUSR1); 119 sigaddset(&ss, SIGUSR2); 120 sigaddset(&ss, SIGTERM); 121 sigaddset(&ss, SIGWINCH); 122 123 ++td->td_critcount; 124 ++gd->gd_intr_nesting_level; 125 while (CPUMASK_TESTMASK(stopped_cpus, gd->gd_cpumask)) { 126 sigsuspend(&ss); 127 } 128 --gd->gd_intr_nesting_level; 129 --td->td_critcount; 130 } 131 132 /* 133 * SIGIO is used by cothreads to signal back into the virtual kernel. 134 */ 135 static 136 void 137 kqueuesig(int nada, siginfo_t *info, void *ctxp) 138 { 139 globaldata_t gd = mycpu; 140 thread_t td = gd->gd_curthread; 141 142 if (td->td_critcount == 0) { 143 ++td->td_critcount; 144 ++gd->gd_intr_nesting_level; 145 kqueue_intr(NULL); 146 --gd->gd_intr_nesting_level; 147 --td->td_critcount; 148 } else { 149 need_kqueue(); 150 } 151 } 152 153 static 154 void 155 timersig(int nada, siginfo_t *info, void *ctxp) 156 { 157 globaldata_t gd = mycpu; 158 thread_t td = gd->gd_curthread; 159 160 if (td->td_critcount == 0) { 161 ++td->td_critcount; 162 ++gd->gd_intr_nesting_level; 163 vktimer_intr(NULL); 164 --gd->gd_intr_nesting_level; 165 --td->td_critcount; 166 } else { 167 need_timer(); 168 } 169 } 170 171 static 172 void 173 cosig(int nada, siginfo_t *info, void *ctxp) 174 { 175 /* handles critical section checks */ 176 signalintr(1); 177 } 178 179 static 180 void 181 infosig(int nada, siginfo_t *info, void *ctxp) 182 { 183 ucontext_t *ctx = ctxp; 184 char buf[256]; 185 186 snprintf(buf, sizeof(buf), "lwp %d pc=%p sp=%p\n", 187 (lwpid_t)lwp_gettid(), 188 (void *)(intptr_t)ctx->uc_mcontext.mc_rip, 189 (void *)(intptr_t)ctx->uc_mcontext.mc_rsp); 190 write(2, buf, strlen(buf)); 191 } 192 193 void 194 init_exceptions(void) 195 { 196 struct sigaction sa; 197 198 bzero(&sa, sizeof(sa)); 199 sa.sa_sigaction = exc_segfault; 200 sa.sa_flags |= SA_SIGINFO | SA_NODEFER; 201 sigemptyset(&sa.sa_mask); 202 sigaction(SIGBUS, &sa, NULL); 203 sigaction(SIGSEGV, &sa, NULL); 204 sigaction(SIGTRAP, &sa, NULL); 205 sigaction(SIGFPE, &sa, NULL); 206 207 sa.sa_flags &= ~SA_NODEFER; 208 209 #ifdef DDB 210 sa.sa_sigaction = exc_debugger; 211 sigaction(SIGQUIT, &sa, NULL); 212 #endif 213 sa.sa_sigaction = ipisig; 214 sigaction(SIGUSR1, &sa, NULL); 215 216 sa.sa_sigaction = stopsig; 217 sigaction(SIGXCPU, &sa, NULL); 218 219 sa.sa_sigaction = kqueuesig; 220 sigaction(SIGIO, &sa, NULL); 221 222 sa.sa_sigaction = timersig; 223 sigaction(SIGURG, &sa, NULL); 224 225 sa.sa_sigaction = cosig; 226 sigaction(SIGALRM, &sa, NULL); 227 228 sa.sa_sigaction = infosig; 229 sigaction(SIGINFO, &sa, NULL); 230 } 231 232 /* 233 * This function handles a segmentation fault. 234 * 235 * XXX We assume that trapframe is a subset of ucontext. It is as of 236 * this writing. 237 */ 238 static void 239 exc_segfault(int signo, siginfo_t *info, void *ctxp) 240 { 241 ucontext_t *ctx = ctxp; 242 243 #if 0 244 kprintf("CAUGHT SIG %d RIP %08lx ERR %08lx TRAPNO %ld " 245 "err %ld addr %08lx\n", 246 signo, 247 ctx->uc_mcontext.mc_rip, 248 ctx->uc_mcontext.mc_err, 249 ctx->uc_mcontext.mc_trapno & 0xFFFF, 250 ctx->uc_mcontext.mc_trapno >> 16, 251 ctx->uc_mcontext.mc_addr); 252 #endif 253 kern_trap((struct trapframe *)&ctx->uc_mcontext.mc_rdi); 254 splz(); 255 } 256 257 #ifdef DDB 258 259 static void 260 exc_debugger(int signo, siginfo_t *info, void *ctxp) 261 { 262 ucontext_t *ctx = ctxp; 263 264 kprintf("CAUGHT SIG %d RIP %08lx RSP %08lx TD %p\n", 265 signo, 266 ctx->uc_mcontext.mc_rip, 267 ctx->uc_mcontext.mc_rsp, 268 curthread); 269 Debugger("interrupt from console"); 270 } 271 272 #endif 273