1 /* $NetBSD: undefined.c,v 1.14 2002/04/12 18:50:31 thorpej 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 51 #include <sys/param.h> 52 53 __KERNEL_RCSID(0, "$NetBSD: undefined.c,v 1.14 2002/04/12 18:50:31 thorpej Exp $"); 54 55 #include <sys/malloc.h> 56 #include <sys/queue.h> 57 #include <sys/signal.h> 58 #include <sys/systm.h> 59 #include <sys/proc.h> 60 #include <sys/user.h> 61 #include <sys/syslog.h> 62 #include <sys/vmmeter.h> 63 #ifdef FAST_FPE 64 #include <sys/acct.h> 65 #endif 66 67 #include <uvm/uvm_extern.h> 68 69 #include <machine/cpu.h> 70 #include <machine/frame.h> 71 #include <arm/undefined.h> 72 #include <machine/trap.h> 73 74 #include <arch/arm/arm/disassem.h> 75 76 #ifdef acorn26 77 #include <machine/machdep.h> 78 #endif 79 80 static int gdb_trapper(u_int, u_int, struct trapframe *, int); 81 82 #ifdef FAST_FPE 83 extern int want_resched; 84 #endif 85 86 LIST_HEAD(, undefined_handler) undefined_handlers[MAX_COPROCS]; 87 88 89 void * 90 install_coproc_handler(int coproc, undef_handler_t handler) 91 { 92 struct undefined_handler *uh; 93 94 KASSERT(coproc >= 0 && coproc < MAX_COPROCS); 95 KASSERT(handler != NULL); /* Used to be legal. */ 96 97 /* XXX: M_TEMP??? */ 98 MALLOC(uh, struct undefined_handler *, sizeof(*uh), M_TEMP, M_WAITOK); 99 uh->uh_handler = handler; 100 install_coproc_handler_static(coproc, uh); 101 return uh; 102 } 103 104 void 105 install_coproc_handler_static(int coproc, struct undefined_handler *uh) 106 { 107 108 LIST_INSERT_HEAD(&undefined_handlers[coproc], uh, uh_link); 109 } 110 111 void 112 remove_coproc_handler(void *cookie) 113 { 114 struct undefined_handler *uh = cookie; 115 116 LIST_REMOVE(uh, uh_link); 117 FREE(uh, M_TEMP); 118 } 119 120 121 static int 122 gdb_trapper(u_int addr, u_int insn, struct trapframe *frame, int code) 123 { 124 125 if ((insn == GDB_BREAKPOINT || insn == GDB5_BREAKPOINT) && 126 code == FAULT_USER) { 127 trapsignal(curproc, SIGTRAP, 0); 128 return 0; 129 } 130 return 1; 131 } 132 133 static struct undefined_handler gdb_uh; 134 135 void 136 undefined_init() 137 { 138 int loop; 139 140 /* Not actually necessary -- the initialiser is just NULL */ 141 for (loop = 0; loop < MAX_COPROCS; ++loop) 142 LIST_INIT(&undefined_handlers[loop]); 143 144 /* Install handler for GDB breakpoints */ 145 gdb_uh.uh_handler = gdb_trapper; 146 install_coproc_handler_static(0, &gdb_uh); 147 } 148 149 150 void 151 undefinedinstruction(trapframe_t *frame) 152 { 153 struct proc *p; 154 u_int fault_pc; 155 int fault_instruction; 156 int fault_code; 157 int coprocessor; 158 struct undefined_handler *uh; 159 160 /* Enable interrupts if they were enabled before the exception. */ 161 #ifdef acorn26 162 if ((frame->tf_r15 & R15_IRQ_DISABLE) == 0) 163 int_on(); 164 #else 165 if (!(frame->tf_spsr & I32_bit)) 166 enable_interrupts(I32_bit); 167 #endif 168 169 #ifndef acorn26 170 frame->tf_pc -= INSN_SIZE; 171 #endif 172 173 #ifdef __PROG26 174 fault_pc = frame->tf_r15 & R15_PC; 175 #else 176 fault_pc = frame->tf_pc; 177 #endif 178 179 /* 180 * Should use fuword() here .. but in the interests of squeezing every 181 * bit of speed we will just use ReadWord(). We know the instruction 182 * can be read as was just executed so this will never fail unless the 183 * kernel is screwed up in which case it does not really matter does 184 * it ? 185 */ 186 187 fault_instruction = *(u_int32_t *)fault_pc; 188 189 /* Update vmmeter statistics */ 190 uvmexp.traps++; 191 192 /* Check for coprocessor instruction */ 193 194 /* 195 * According to the datasheets you only need to look at bit 27 of the 196 * instruction to tell the difference between and undefined 197 * instruction and a coprocessor instruction following an undefined 198 * instruction trap. 199 */ 200 201 if ((fault_instruction & (1 << 27)) != 0) 202 coprocessor = (fault_instruction >> 8) & 0x0f; 203 else 204 coprocessor = 0; 205 206 /* Get the current proc structure or proc0 if there is none. */ 207 208 if ((p = curproc) == 0) 209 p = &proc0; 210 211 #ifdef __PROG26 212 if ((frame->tf_r15 & R15_MODE) == R15_MODE_USR) { 213 #else 214 if ((frame->tf_spsr & PSR_MODE) == PSR_USR32_MODE) { 215 #endif 216 /* 217 * Modify the fault_code to reflect the USR/SVC state at 218 * time of fault. 219 */ 220 fault_code = FAULT_USER; 221 p->p_addr->u_pcb.pcb_tf = frame; 222 } else 223 fault_code = 0; 224 225 /* OK this is were we do something about the instruction. */ 226 LIST_FOREACH(uh, &undefined_handlers[coprocessor], uh_link) 227 if (uh->uh_handler(fault_pc, fault_instruction, frame, 228 fault_code) == 0) 229 break; 230 231 if (uh == NULL) { 232 /* Fault has not been handled */ 233 234 #ifdef VERBOSE_ARM32 235 s = spltty(); 236 237 if ((fault_instruction & 0x0f000010) == 0x0e000000) { 238 printf("CDP\n"); 239 disassemble(fault_pc); 240 } else if ((fault_instruction & 0x0e000000) == 0x0c000000) { 241 printf("LDC/STC\n"); 242 disassemble(fault_pc); 243 } else if ((fault_instruction & 0x0f000010) == 0x0e000010) { 244 printf("MRC/MCR\n"); 245 disassemble(fault_pc); 246 } else if ((fault_instruction & ~INSN_COND_MASK) 247 != (KERNEL_BREAKPOINT & ~INSN_COND_MASK)) { 248 printf("Undefined instruction\n"); 249 disassemble(fault_pc); 250 } 251 252 splx(s); 253 #endif 254 255 if ((fault_code & FAULT_USER) == 0) { 256 printf("Undefined instruction in kernel\n"); 257 #ifdef DDB 258 Debugger(); 259 #endif 260 } 261 262 trapsignal(p, SIGILL, fault_instruction); 263 } 264 265 if ((fault_code & FAULT_USER) == 0) 266 return; 267 268 #ifdef FAST_FPE 269 /* Optimised exit code */ 270 { 271 int sig; 272 273 /* take pending signals */ 274 275 while ((sig = (CURSIG(p))) != 0) { 276 postsig(sig); 277 } 278 279 p->p_priority = p->p_usrpri; 280 281 /* 282 * Check for reschedule request, at the moment there is only 283 * 1 ast so this code should always be run 284 */ 285 286 if (want_resched) { 287 /* 288 * We are being preempted. 289 */ 290 preempt(NULL); 291 while ((sig = (CURSIG(p))) != 0) { 292 postsig(sig); 293 } 294 } 295 296 curcpu()->ci_schedstate.spc_curpriority = p->p_priority; 297 } 298 299 #else 300 userret(p); 301 #endif 302 } 303