1 /* $NetBSD: undefined.c,v 1.17 2003/04/28 01:54:49 briggs 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 1.17 2003/04/28 01:54:49 briggs 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 72 #include <uvm/uvm_extern.h> 73 74 #include <machine/cpu.h> 75 #include <machine/frame.h> 76 #include <arm/undefined.h> 77 #include <machine/trap.h> 78 79 #include <arch/arm/arm/disassem.h> 80 81 #ifdef acorn26 82 #include <machine/machdep.h> 83 #endif 84 85 static int gdb_trapper(u_int, u_int, struct trapframe *, int); 86 87 #ifdef FAST_FPE 88 extern int want_resched; 89 #endif 90 91 LIST_HEAD(, undefined_handler) undefined_handlers[MAX_COPROCS]; 92 93 94 void * 95 install_coproc_handler(int coproc, undef_handler_t handler) 96 { 97 struct undefined_handler *uh; 98 99 KASSERT(coproc >= 0 && coproc < MAX_COPROCS); 100 KASSERT(handler != NULL); /* Used to be legal. */ 101 102 /* XXX: M_TEMP??? */ 103 MALLOC(uh, struct undefined_handler *, sizeof(*uh), M_TEMP, M_WAITOK); 104 uh->uh_handler = handler; 105 install_coproc_handler_static(coproc, uh); 106 return uh; 107 } 108 109 void 110 install_coproc_handler_static(int coproc, struct undefined_handler *uh) 111 { 112 113 LIST_INSERT_HEAD(&undefined_handlers[coproc], uh, uh_link); 114 } 115 116 void 117 remove_coproc_handler(void *cookie) 118 { 119 struct undefined_handler *uh = cookie; 120 121 LIST_REMOVE(uh, uh_link); 122 FREE(uh, M_TEMP); 123 } 124 125 126 static int 127 gdb_trapper(u_int addr, u_int insn, struct trapframe *frame, int code) 128 { 129 130 if (insn == GDB_BREAKPOINT || insn == GDB5_BREAKPOINT) { 131 if (code == FAULT_USER) { 132 trapsignal(curlwp, SIGTRAP, 0); 133 return 0; 134 } 135 #ifdef KGDB 136 return !kgdb_trap(T_BREAKPOINT, frame); 137 #endif 138 } 139 return 1; 140 } 141 142 static struct undefined_handler gdb_uh; 143 144 void 145 undefined_init() 146 { 147 int loop; 148 149 /* Not actually necessary -- the initialiser is just NULL */ 150 for (loop = 0; loop < MAX_COPROCS; ++loop) 151 LIST_INIT(&undefined_handlers[loop]); 152 153 /* Install handler for GDB breakpoints */ 154 gdb_uh.uh_handler = gdb_trapper; 155 install_coproc_handler_static(0, &gdb_uh); 156 } 157 158 159 void 160 undefinedinstruction(trapframe_t *frame) 161 { 162 struct proc *p; 163 struct lwp *l; 164 u_int fault_pc; 165 int fault_instruction; 166 int fault_code; 167 int coprocessor; 168 struct undefined_handler *uh; 169 #ifdef VERBOSE_ARM32 170 int s; 171 #endif 172 173 /* Enable interrupts if they were enabled before the exception. */ 174 #ifdef acorn26 175 if ((frame->tf_r15 & R15_IRQ_DISABLE) == 0) 176 int_on(); 177 #else 178 if (!(frame->tf_spsr & I32_bit)) 179 enable_interrupts(I32_bit); 180 #endif 181 182 #ifndef acorn26 183 frame->tf_pc -= INSN_SIZE; 184 #endif 185 186 #ifdef __PROG26 187 fault_pc = frame->tf_r15 & R15_PC; 188 #else 189 fault_pc = frame->tf_pc; 190 #endif 191 192 /* 193 * Should use fuword() here .. but in the interests of squeezing every 194 * bit of speed we will just use ReadWord(). We know the instruction 195 * can be read as was just executed so this will never fail unless the 196 * kernel is screwed up in which case it does not really matter does 197 * it ? 198 */ 199 200 fault_instruction = *(u_int32_t *)fault_pc; 201 202 /* Update vmmeter statistics */ 203 uvmexp.traps++; 204 205 /* Check for coprocessor instruction */ 206 207 /* 208 * According to the datasheets you only need to look at bit 27 of the 209 * instruction to tell the difference between and undefined 210 * instruction and a coprocessor instruction following an undefined 211 * instruction trap. 212 */ 213 214 if ((fault_instruction & (1 << 27)) != 0) 215 coprocessor = (fault_instruction >> 8) & 0x0f; 216 else 217 coprocessor = 0; 218 219 /* Get the current lwp/proc structure or lwp0/proc0 if there is none. */ 220 l = curlwp == NULL ? &lwp0 : curlwp; 221 p = l->l_proc; 222 223 #ifdef __PROG26 224 if ((frame->tf_r15 & R15_MODE) == R15_MODE_USR) { 225 #else 226 if ((frame->tf_spsr & PSR_MODE) == PSR_USR32_MODE) { 227 #endif 228 /* 229 * Modify the fault_code to reflect the USR/SVC state at 230 * time of fault. 231 */ 232 fault_code = FAULT_USER; 233 l->l_addr->u_pcb.pcb_tf = frame; 234 } else 235 fault_code = 0; 236 237 /* OK this is were we do something about the instruction. */ 238 LIST_FOREACH(uh, &undefined_handlers[coprocessor], uh_link) 239 if (uh->uh_handler(fault_pc, fault_instruction, frame, 240 fault_code) == 0) 241 break; 242 243 if (uh == NULL) { 244 /* Fault has not been handled */ 245 246 #ifdef VERBOSE_ARM32 247 s = spltty(); 248 249 if ((fault_instruction & 0x0f000010) == 0x0e000000) { 250 printf("CDP\n"); 251 disassemble(fault_pc); 252 } else if ((fault_instruction & 0x0e000000) == 0x0c000000) { 253 printf("LDC/STC\n"); 254 disassemble(fault_pc); 255 } else if ((fault_instruction & 0x0f000010) == 0x0e000010) { 256 printf("MRC/MCR\n"); 257 disassemble(fault_pc); 258 } else if ((fault_instruction & ~INSN_COND_MASK) 259 != (KERNEL_BREAKPOINT & ~INSN_COND_MASK)) { 260 printf("Undefined instruction\n"); 261 disassemble(fault_pc); 262 } 263 264 splx(s); 265 #endif 266 267 if ((fault_code & FAULT_USER) == 0) { 268 printf("Undefined instruction in kernel\n"); 269 #ifdef DDB 270 Debugger(); 271 #endif 272 } 273 274 trapsignal(l, SIGILL, fault_instruction); 275 } 276 277 if ((fault_code & FAULT_USER) == 0) 278 return; 279 280 #ifdef FAST_FPE 281 /* Optimised exit code */ 282 { 283 int sig; 284 285 /* 286 * Check for reschedule request, at the moment there is only 287 * 1 ast so this code should always be run 288 */ 289 290 if (want_resched) { 291 /* 292 * We are being preempted. 293 */ 294 preempt(0); 295 } 296 297 /* take pending signals */ 298 while ((sig = (CURSIG(l))) != 0) { 299 postsig(sig); 300 } 301 302 /* Invoke per-process kernel-exit handling, if any */ 303 if (p->p_userret) 304 (p->p_userret)(l, p->p_userret_arg); 305 306 /* Invoke any pending upcalls. */ 307 while (l->l_flag & L_SA_UPCALL) 308 sa_upcall_userret(l); 309 310 l->l_priority = l->l_usrpri; 311 312 curcpu()->ci_schedstate.spc_curpriority = l->l_priority; 313 } 314 315 #else 316 userret(p); 317 #endif 318 } 319