1 /* $OpenBSD: undefined.c,v 1.2 2004/02/23 19:09:57 drahn Exp $ */ 2 /* $NetBSD: undefined.c,v 1.22 2003/11/29 22:21:29 bjh21 Exp $ */ 3 4 /* 5 * Copyright (c) 2001 Ben Harris. 6 * Copyright (c) 1995 Mark Brinicombe. 7 * Copyright (c) 1995 Brini. 8 * All rights reserved. 9 * 10 * This code is derived from software written for Brini by Mark Brinicombe 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by Brini. 23 * 4. The name of the company nor the name of the author may be used to 24 * endorse or promote products derived from this software without specific 25 * prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY BRINI ``AS IS'' AND ANY EXPRESS OR IMPLIED 28 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 29 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 30 * IN NO EVENT SHALL BRINI OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 31 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 32 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 33 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 * 39 * RiscBSD kernel project 40 * 41 * undefined.c 42 * 43 * Fault handler 44 * 45 * Created : 06/01/95 46 */ 47 48 #define FAST_FPE 49 50 #include <sys/param.h> 51 52 #include <sys/malloc.h> 53 #include <sys/queue.h> 54 #include <sys/signal.h> 55 #include <sys/signalvar.h> 56 #include <sys/systm.h> 57 #include <sys/proc.h> 58 #include <sys/user.h> 59 #include <sys/syslog.h> 60 #include <sys/vmmeter.h> 61 #ifdef FAST_FPE 62 #include <sys/acct.h> 63 #endif 64 65 #include <uvm/uvm_extern.h> 66 67 #include <machine/cpu.h> 68 #include <machine/frame.h> 69 #include <arm/undefined.h> 70 #include <machine/trap.h> 71 72 73 #ifdef acorn26 74 #include <machine/machdep.h> 75 #endif 76 77 static int gdb_trapper(u_int, u_int, struct trapframe *, int); 78 79 #ifdef FAST_FPE 80 extern int want_resched; 81 #endif 82 83 LIST_HEAD(, undefined_handler) undefined_handlers[MAX_COPROCS]; 84 85 86 void * 87 install_coproc_handler(int coproc, undef_handler_t handler) 88 { 89 struct undefined_handler *uh; 90 91 KASSERT(coproc >= 0 && coproc < MAX_COPROCS); 92 KASSERT(handler != NULL); /* Used to be legal. */ 93 94 /* XXX: M_TEMP??? */ 95 MALLOC(uh, struct undefined_handler *, sizeof(*uh), M_TEMP, M_WAITOK); 96 uh->uh_handler = handler; 97 install_coproc_handler_static(coproc, uh); 98 return uh; 99 } 100 101 void 102 install_coproc_handler_static(int coproc, struct undefined_handler *uh) 103 { 104 105 LIST_INSERT_HEAD(&undefined_handlers[coproc], uh, uh_link); 106 } 107 108 void 109 remove_coproc_handler(void *cookie) 110 { 111 struct undefined_handler *uh = cookie; 112 113 LIST_REMOVE(uh, uh_link); 114 FREE(uh, M_TEMP); 115 } 116 117 118 static int 119 gdb_trapper(u_int addr, u_int insn, struct trapframe *frame, int code) 120 { 121 union sigval sv; 122 struct proc *p; 123 p = (curproc == NULL) ? &proc0 : curproc; 124 125 if (insn == GDB_BREAKPOINT || insn == GDB5_BREAKPOINT) { 126 if (code == FAULT_USER) { 127 sv.sival_int = addr; 128 trapsignal(p, SIGTRAP, 0, TRAP_BRKPT, sv); 129 return 0; 130 } 131 #ifdef KGDB 132 return !kgdb_trap(T_BREAKPOINT, frame); 133 #endif 134 } 135 return 1; 136 } 137 138 static struct undefined_handler gdb_uh; 139 140 void 141 undefined_init() 142 { 143 int loop; 144 145 /* Not actually necessary -- the initialiser is just NULL */ 146 for (loop = 0; loop < MAX_COPROCS; ++loop) 147 LIST_INIT(&undefined_handlers[loop]); 148 149 /* Install handler for GDB breakpoints */ 150 gdb_uh.uh_handler = gdb_trapper; 151 install_coproc_handler_static(0, &gdb_uh); 152 } 153 154 155 void 156 undefinedinstruction(trapframe_t *frame) 157 { 158 struct proc *p; 159 u_int fault_pc; 160 int fault_instruction; 161 int fault_code; 162 int coprocessor; 163 struct undefined_handler *uh; 164 #ifdef VERBOSE_ARM32 165 int s; 166 #endif 167 union sigval sv; 168 169 /* Enable interrupts if they were enabled before the exception. */ 170 #ifdef acorn26 171 if ((frame->tf_r15 & R15_IRQ_DISABLE) == 0) 172 int_on(); 173 #else 174 if (!(frame->tf_spsr & I32_bit)) 175 enable_interrupts(I32_bit); 176 #endif 177 178 #ifndef acorn26 179 frame->tf_pc -= INSN_SIZE; 180 #endif 181 182 #ifdef __PROG26 183 fault_pc = frame->tf_r15 & R15_PC; 184 #else 185 fault_pc = frame->tf_pc; 186 #endif 187 188 /* Get the current proc structure or proc0 if there is none. */ 189 p = (curproc == NULL) ? &proc0 : curproc; 190 191 /* 192 * Make sure the program counter is correctly aligned so we 193 * don't take an alignment fault trying to read the opcode. 194 */ 195 if (__predict_false((fault_pc & 3) != 0)) { 196 /* Give the user an illegal instruction signal. */ 197 sv.sival_int = (u_int32_t) fault_pc; 198 trapsignal(p, SIGILL, 0, ILL_ILLOPC, sv); 199 userret(p, fault_pc, p->p_sticks); 200 return; 201 } 202 203 /* 204 * Should use fuword() here .. but in the interests of squeezing every 205 * bit of speed we will just use ReadWord(). We know the instruction 206 * can be read as was just executed so this will never fail unless the 207 * kernel is screwed up in which case it does not really matter does 208 * it ? 209 */ 210 211 fault_instruction = *(u_int32_t *)fault_pc; 212 213 /* Update vmmeter statistics */ 214 uvmexp.traps++; 215 216 /* Check for coprocessor instruction */ 217 218 /* 219 * According to the datasheets you only need to look at bit 27 of the 220 * instruction to tell the difference between and undefined 221 * instruction and a coprocessor instruction following an undefined 222 * instruction trap. 223 */ 224 225 if ((fault_instruction & (1 << 27)) != 0) 226 coprocessor = (fault_instruction >> 8) & 0x0f; 227 else 228 coprocessor = 0; 229 230 /* Get the current proc structure or proc0 if there is none. */ 231 232 if ((p = curproc) == 0) 233 p = &proc0; 234 235 #ifdef __PROG26 236 if ((frame->tf_r15 & R15_MODE) == R15_MODE_USR) 237 #else 238 if ((frame->tf_spsr & PSR_MODE) == PSR_USR32_MODE) 239 #endif 240 { 241 /* 242 * Modify the fault_code to reflect the USR/SVC state at 243 * time of fault. 244 */ 245 fault_code = FAULT_USER; 246 p->p_addr->u_pcb.pcb_tf = frame; 247 } else 248 fault_code = 0; 249 250 /* OK this is were we do something about the instruction. */ 251 LIST_FOREACH(uh, &undefined_handlers[coprocessor], uh_link) 252 if (uh->uh_handler(fault_pc, fault_instruction, frame, 253 fault_code) == 0) 254 break; 255 256 if (uh == NULL) { 257 /* Fault has not been handled */ 258 259 #ifdef VERBOSE_ARM32 260 s = spltty(); 261 262 if ((fault_instruction & 0x0f000010) == 0x0e000000) { 263 printf("CDP\n"); 264 disassemble(fault_pc); 265 } else if ((fault_instruction & 0x0e000000) == 0x0c000000) { 266 printf("LDC/STC\n"); 267 disassemble(fault_pc); 268 } else if ((fault_instruction & 0x0f000010) == 0x0e000010) { 269 printf("MRC/MCR\n"); 270 disassemble(fault_pc); 271 } else if ((fault_instruction & ~INSN_COND_MASK) 272 != (KERNEL_BREAKPOINT & ~INSN_COND_MASK)) { 273 printf("Undefined instruction\n"); 274 disassemble(fault_pc); 275 } 276 277 splx(s); 278 #endif 279 280 if ((fault_code & FAULT_USER) == 0) { 281 printf("Undefined instruction in kernel\n"); 282 #ifdef DDB 283 Debugger(); 284 #endif 285 } 286 287 sv.sival_int = frame->tf_pc; 288 trapsignal(p, SIGILL, 0, ILL_ILLOPC, sv); 289 } 290 291 if ((fault_code & FAULT_USER) == 0) 292 return; 293 294 #ifdef FAST_FPE 295 /* Optimised exit code */ 296 { 297 int sig; 298 299 /* take pending signals */ 300 301 while ((sig = (CURSIG(p))) != 0) { 302 postsig(sig); 303 } 304 305 p->p_priority = p->p_usrpri; 306 307 /* 308 * Check for reschedule request, at the moment there is only 309 * 1 ast so this code should always be run 310 */ 311 312 if (want_resched) { 313 /* 314 * We are being preempted. 315 */ 316 preempt(NULL); 317 while ((sig = (CURSIG(p))) != 0) { 318 postsig(sig); 319 } 320 } 321 322 /* XXX 323 curcpu()->ci_schedstate.spc_curpriority = p->p_priority; 324 */ 325 } 326 327 #else 328 userret(p); 329 userret(p, frame->tf_pc, p->p_sticks); 330 #endif 331 } 332