1 /* $NetBSD: undefined.c,v 1.22 2003/11/29 22:21:29 bjh21 Exp $ */ 2 3 /* 4 * Copyright (c) 2001 Ben Harris. 5 * Copyright (c) 1995 Mark Brinicombe. 6 * Copyright (c) 1995 Brini. 7 * All rights reserved. 8 * 9 * This code is derived from software written for Brini by Mark Brinicombe 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 Brini. 22 * 4. The name of the company nor the name of the author may be used to 23 * endorse or promote products derived from this software without specific 24 * prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY BRINI ``AS IS'' AND ANY EXPRESS OR IMPLIED 27 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 28 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 29 * IN NO EVENT SHALL BRINI OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 30 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 31 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 32 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * RiscBSD kernel project 39 * 40 * undefined.c 41 * 42 * Fault handler 43 * 44 * Created : 06/01/95 45 */ 46 47 #define FAST_FPE 48 49 #include "opt_ddb.h" 50 #include "opt_kgdb.h" 51 52 #include <sys/param.h> 53 #ifdef KGDB 54 #include <sys/kgdb.h> 55 #endif 56 57 __KERNEL_RCSID(0, "$NetBSD: undefined.c,v 1.22 2003/11/29 22:21:29 bjh21 Exp $"); 58 59 #include <sys/malloc.h> 60 #include <sys/queue.h> 61 #include <sys/signal.h> 62 #include <sys/systm.h> 63 #include <sys/proc.h> 64 #include <sys/user.h> 65 #include <sys/syslog.h> 66 #include <sys/vmmeter.h> 67 #include <sys/savar.h> 68 #ifdef FAST_FPE 69 #include <sys/acct.h> 70 #endif 71 #include <sys/userret.h> 72 73 #include <uvm/uvm_extern.h> 74 75 #include <machine/cpu.h> 76 #include <machine/frame.h> 77 #include <arm/undefined.h> 78 #include <machine/trap.h> 79 80 #include <arch/arm/arm/disassem.h> 81 82 #ifdef DDB 83 #include <ddb/db_output.h> 84 #include <machine/db_machdep.h> 85 #endif 86 87 #ifdef acorn26 88 #include <machine/machdep.h> 89 #endif 90 91 static int gdb_trapper(u_int, u_int, struct trapframe *, int); 92 93 #ifdef FAST_FPE 94 extern int want_resched; 95 #endif 96 97 LIST_HEAD(, undefined_handler) undefined_handlers[MAX_COPROCS]; 98 99 100 void * 101 install_coproc_handler(int coproc, undef_handler_t handler) 102 { 103 struct undefined_handler *uh; 104 105 KASSERT(coproc >= 0 && coproc < MAX_COPROCS); 106 KASSERT(handler != NULL); /* Used to be legal. */ 107 108 /* XXX: M_TEMP??? */ 109 MALLOC(uh, struct undefined_handler *, sizeof(*uh), M_TEMP, M_WAITOK); 110 uh->uh_handler = handler; 111 install_coproc_handler_static(coproc, uh); 112 return uh; 113 } 114 115 void 116 install_coproc_handler_static(int coproc, struct undefined_handler *uh) 117 { 118 119 LIST_INSERT_HEAD(&undefined_handlers[coproc], uh, uh_link); 120 } 121 122 void 123 remove_coproc_handler(void *cookie) 124 { 125 struct undefined_handler *uh = cookie; 126 127 LIST_REMOVE(uh, uh_link); 128 FREE(uh, M_TEMP); 129 } 130 131 132 static int 133 gdb_trapper(u_int addr, u_int insn, struct trapframe *frame, int code) 134 { 135 struct lwp *l; 136 l = (curlwp == NULL) ? &lwp0 : curlwp; 137 138 if (insn == GDB_BREAKPOINT || insn == GDB5_BREAKPOINT) { 139 if (code == FAULT_USER) { 140 ksiginfo_t ksi; 141 142 KSI_INIT_TRAP(&ksi); 143 ksi.ksi_signo = SIGTRAP; 144 ksi.ksi_code = TRAP_BRKPT; 145 ksi.ksi_addr = (u_int32_t *)addr; 146 ksi.ksi_trap = 0; 147 KERNEL_PROC_LOCK(l->l_proc); 148 trapsignal(l, &ksi); 149 KERNEL_PROC_UNLOCK(l->l_proc); 150 return 0; 151 } 152 #ifdef KGDB 153 return !kgdb_trap(T_BREAKPOINT, frame); 154 #endif 155 } 156 return 1; 157 } 158 159 static struct undefined_handler gdb_uh; 160 161 void 162 undefined_init() 163 { 164 int loop; 165 166 /* Not actually necessary -- the initialiser is just NULL */ 167 for (loop = 0; loop < MAX_COPROCS; ++loop) 168 LIST_INIT(&undefined_handlers[loop]); 169 170 /* Install handler for GDB breakpoints */ 171 gdb_uh.uh_handler = gdb_trapper; 172 install_coproc_handler_static(0, &gdb_uh); 173 } 174 175 176 void 177 undefinedinstruction(trapframe_t *frame) 178 { 179 struct lwp *l; 180 u_int fault_pc; 181 int fault_instruction; 182 int fault_code; 183 int coprocessor; 184 struct undefined_handler *uh; 185 #ifdef VERBOSE_ARM32 186 int s; 187 #endif 188 189 /* Enable interrupts if they were enabled before the exception. */ 190 #ifdef acorn26 191 if ((frame->tf_r15 & R15_IRQ_DISABLE) == 0) 192 int_on(); 193 #else 194 if (!(frame->tf_spsr & I32_bit)) 195 enable_interrupts(I32_bit); 196 #endif 197 198 #ifndef acorn26 199 frame->tf_pc -= INSN_SIZE; 200 #endif 201 202 #ifdef __PROG26 203 fault_pc = frame->tf_r15 & R15_PC; 204 #else 205 fault_pc = frame->tf_pc; 206 #endif 207 208 /* Get the current lwp/proc structure or lwp0/proc0 if there is none. */ 209 l = curlwp == NULL ? &lwp0 : curlwp; 210 211 /* 212 * Make sure the program counter is correctly aligned so we 213 * don't take an alignment fault trying to read the opcode. 214 */ 215 if (__predict_false((fault_pc & 3) != 0)) { 216 ksiginfo_t ksi; 217 /* Give the user an illegal instruction signal. */ 218 KSI_INIT_TRAP(&ksi); 219 ksi.ksi_signo = SIGILL; 220 ksi.ksi_code = ILL_ILLOPC; 221 ksi.ksi_addr = (u_int32_t *)(intptr_t) fault_pc; 222 KERNEL_PROC_LOCK(l); 223 trapsignal(l, &ksi); 224 KERNEL_PROC_UNLOCK(l); 225 userret(l); 226 return; 227 } 228 229 /* 230 * Should use fuword() here .. but in the interests of squeezing every 231 * bit of speed we will just use ReadWord(). We know the instruction 232 * can be read as was just executed so this will never fail unless the 233 * kernel is screwed up in which case it does not really matter does 234 * it ? 235 */ 236 237 fault_instruction = *(u_int32_t *)fault_pc; 238 239 /* Update vmmeter statistics */ 240 uvmexp.traps++; 241 242 /* Check for coprocessor instruction */ 243 244 /* 245 * According to the datasheets you only need to look at bit 27 of the 246 * instruction to tell the difference between and undefined 247 * instruction and a coprocessor instruction following an undefined 248 * instruction trap. 249 */ 250 251 if ((fault_instruction & (1 << 27)) != 0) 252 coprocessor = (fault_instruction >> 8) & 0x0f; 253 else 254 coprocessor = 0; 255 256 #ifdef __PROG26 257 if ((frame->tf_r15 & R15_MODE) == R15_MODE_USR) { 258 #else 259 if ((frame->tf_spsr & PSR_MODE) == PSR_USR32_MODE) { 260 #endif 261 /* 262 * Modify the fault_code to reflect the USR/SVC state at 263 * time of fault. 264 */ 265 fault_code = FAULT_USER; 266 l->l_addr->u_pcb.pcb_tf = frame; 267 } else 268 fault_code = 0; 269 270 /* OK this is were we do something about the instruction. */ 271 LIST_FOREACH(uh, &undefined_handlers[coprocessor], uh_link) 272 if (uh->uh_handler(fault_pc, fault_instruction, frame, 273 fault_code) == 0) 274 break; 275 276 if (uh == NULL) { 277 /* Fault has not been handled */ 278 ksiginfo_t ksi; 279 280 #ifdef VERBOSE_ARM32 281 s = spltty(); 282 283 if ((fault_instruction & 0x0f000010) == 0x0e000000) { 284 printf("CDP\n"); 285 disassemble(fault_pc); 286 } else if ((fault_instruction & 0x0e000000) == 0x0c000000) { 287 printf("LDC/STC\n"); 288 disassemble(fault_pc); 289 } else if ((fault_instruction & 0x0f000010) == 0x0e000010) { 290 printf("MRC/MCR\n"); 291 disassemble(fault_pc); 292 } else if ((fault_instruction & ~INSN_COND_MASK) 293 != (KERNEL_BREAKPOINT & ~INSN_COND_MASK)) { 294 printf("Undefined instruction\n"); 295 disassemble(fault_pc); 296 } 297 298 splx(s); 299 #endif 300 301 if ((fault_code & FAULT_USER) == 0) { 302 #ifdef DDB 303 db_printf("Undefined instruction in kernel\n"); 304 kdb_trap(T_FAULT, frame); 305 #else 306 panic("undefined instruction in kernel"); 307 #endif 308 } 309 KSI_INIT_TRAP(&ksi); 310 ksi.ksi_signo = SIGILL; 311 ksi.ksi_code = ILL_ILLOPC; 312 ksi.ksi_addr = (u_int32_t *)fault_pc; 313 ksi.ksi_trap = fault_instruction; 314 KERNEL_PROC_LOCK(l); 315 trapsignal(l, &ksi); 316 KERNEL_PROC_UNLOCK(l); 317 } 318 319 if ((fault_code & FAULT_USER) == 0) 320 return; 321 322 #ifdef FAST_FPE 323 /* Optimised exit code */ 324 { 325 326 /* 327 * Check for reschedule request, at the moment there is only 328 * 1 ast so this code should always be run 329 */ 330 331 if (want_resched) { 332 /* 333 * We are being preempted. 334 */ 335 preempt(0); 336 } 337 338 /* Invoke MI userret code */ 339 mi_userret(l); 340 341 l->l_priority = l->l_usrpri; 342 343 curcpu()->ci_schedstate.spc_curpriority = l->l_priority; 344 } 345 346 #else 347 userret(l); 348 #endif 349 } 350