undefined.c revision 278613
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 48#include "opt_ddb.h" 49 50#include <sys/cdefs.h> 51__FBSDID("$FreeBSD: stable/10/sys/arm/arm/undefined.c 278613 2015-02-12 03:50:33Z ian $"); 52 53#include <sys/param.h> 54#include <sys/malloc.h> 55#include <sys/queue.h> 56#include <sys/signal.h> 57#include <sys/systm.h> 58#include <sys/proc.h> 59#include <sys/syslog.h> 60#include <sys/vmmeter.h> 61#include <sys/lock.h> 62#include <sys/mutex.h> 63#include <sys/signalvar.h> 64#include <sys/ptrace.h> 65#ifdef KDB 66#include <sys/kdb.h> 67#endif 68 69#include <vm/vm.h> 70#include <vm/vm_extern.h> 71 72#include <machine/armreg.h> 73#include <machine/asm.h> 74#include <machine/cpu.h> 75#include <machine/frame.h> 76#include <machine/undefined.h> 77#include <machine/trap.h> 78 79#include <machine/disassem.h> 80 81#ifdef DDB 82#include <ddb/db_output.h> 83#endif 84 85#ifdef KDB 86#include <machine/db_machdep.h> 87#endif 88 89static int gdb_trapper(u_int, u_int, struct trapframe *, int); 90 91LIST_HEAD(, undefined_handler) undefined_handlers[MAX_COPROCS]; 92 93 94void * 95install_coproc_handler(int coproc, undef_handler_t handler) 96{ 97 struct undefined_handler *uh; 98 99 KASSERT(coproc >= 0 && coproc < MAX_COPROCS, ("bad coproc")); 100 KASSERT(handler != NULL, ("handler is NULL")); /* Used to be legal. */ 101 102 /* XXX: M_TEMP??? */ 103 uh = malloc(sizeof(*uh), M_TEMP, M_WAITOK); 104 uh->uh_handler = handler; 105 install_coproc_handler_static(coproc, uh); 106 return uh; 107} 108 109void 110install_coproc_handler_static(int coproc, struct undefined_handler *uh) 111{ 112 113 LIST_INSERT_HEAD(&undefined_handlers[coproc], uh, uh_link); 114} 115 116void 117remove_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 126static int 127gdb_trapper(u_int addr, u_int insn, struct trapframe *frame, int code) 128{ 129 struct thread *td; 130 ksiginfo_t ksi; 131 132 td = (curthread == NULL) ? &thread0 : curthread; 133 134 if (insn == GDB_BREAKPOINT || insn == GDB5_BREAKPOINT) { 135 if (code == FAULT_USER) { 136 ksiginfo_init_trap(&ksi); 137 ksi.ksi_signo = SIGTRAP; 138 ksi.ksi_code = TRAP_BRKPT; 139 ksi.ksi_addr = (u_int32_t *)addr; 140 trapsignal(td, &ksi); 141 return 0; 142 } 143#if 0 144#ifdef KGDB 145 return !kgdb_trap(T_BREAKPOINT, frame); 146#endif 147#endif 148 } 149 return 1; 150} 151 152static struct undefined_handler gdb_uh; 153 154void 155undefined_init() 156{ 157 int loop; 158 159 /* Not actually necessary -- the initialiser is just NULL */ 160 for (loop = 0; loop < MAX_COPROCS; ++loop) 161 LIST_INIT(&undefined_handlers[loop]); 162 163 /* Install handler for GDB breakpoints */ 164 gdb_uh.uh_handler = gdb_trapper; 165 install_coproc_handler_static(0, &gdb_uh); 166} 167 168 169void 170undefinedinstruction(struct trapframe *frame) 171{ 172 struct thread *td; 173 u_int fault_pc; 174 int fault_instruction; 175 int fault_code; 176 int coprocessor; 177 struct undefined_handler *uh; 178#ifdef VERBOSE_ARM32 179 int s; 180#endif 181 ksiginfo_t ksi; 182 183 /* Enable interrupts if they were enabled before the exception. */ 184 if (__predict_true(frame->tf_spsr & PSR_I) == 0) 185 enable_interrupts(PSR_I); 186 if (__predict_true(frame->tf_spsr & PSR_F) == 0) 187 enable_interrupts(PSR_F); 188 189 PCPU_INC(cnt.v_trap); 190 191 fault_pc = frame->tf_pc; 192 193 /* 194 * Get the current thread/proc structure or thread0/proc0 if there is 195 * none. 196 */ 197 td = curthread == NULL ? &thread0 : curthread; 198 199 /* 200 * Make sure the program counter is correctly aligned so we 201 * don't take an alignment fault trying to read the opcode. 202 */ 203 if (__predict_false((fault_pc & 3) != 0)) { 204 ksiginfo_init_trap(&ksi); 205 ksi.ksi_signo = SIGILL; 206 ksi.ksi_code = ILL_ILLADR; 207 ksi.ksi_addr = (u_int32_t *)(intptr_t) fault_pc; 208 trapsignal(td, &ksi); 209 userret(td, frame); 210 return; 211 } 212 213 /* 214 * Should use fuword() here .. but in the interests of squeezing every 215 * bit of speed we will just use ReadWord(). We know the instruction 216 * can be read as was just executed so this will never fail unless the 217 * kernel is screwed up in which case it does not really matter does 218 * it ? 219 */ 220 221 fault_instruction = *(u_int32_t *)fault_pc; 222 223 /* Update vmmeter statistics */ 224#if 0 225 uvmexp.traps++; 226#endif 227 /* Check for coprocessor instruction */ 228 229 /* 230 * According to the datasheets you only need to look at bit 27 of the 231 * instruction to tell the difference between and undefined 232 * instruction and a coprocessor instruction following an undefined 233 * instruction trap. 234 */ 235 236 coprocessor = 0; 237 if ((fault_instruction & (1 << 27)) != 0) 238 coprocessor = (fault_instruction >> 8) & 0x0f; 239#ifdef VFP 240 else { /* check for special instructions */ 241 if (((fault_instruction & 0xfe000000) == 0xf2000000) || 242 ((fault_instruction & 0xff100000) == 0xf4000000)) 243 coprocessor = 10; /* vfp / simd */ 244 } 245#endif /* VFP */ 246 247 if ((frame->tf_spsr & PSR_MODE) == PSR_USR32_MODE) { 248 /* 249 * Modify the fault_code to reflect the USR/SVC state at 250 * time of fault. 251 */ 252 fault_code = FAULT_USER; 253 td->td_frame = frame; 254 } else 255 fault_code = 0; 256 257 /* OK this is were we do something about the instruction. */ 258 LIST_FOREACH(uh, &undefined_handlers[coprocessor], uh_link) 259 if (uh->uh_handler(fault_pc, fault_instruction, frame, 260 fault_code) == 0) 261 break; 262 263 if (fault_code & FAULT_USER && fault_instruction == PTRACE_BREAKPOINT) { 264 PROC_LOCK(td->td_proc); 265 _PHOLD(td->td_proc); 266 ptrace_clear_single_step(td); 267 _PRELE(td->td_proc); 268 PROC_UNLOCK(td->td_proc); 269 return; 270 } 271 272 if (uh == NULL && (fault_code & FAULT_USER)) { 273 /* Fault has not been handled */ 274 ksiginfo_init_trap(&ksi); 275 ksi.ksi_signo = SIGILL; 276 ksi.ksi_code = ILL_ILLOPC; 277 ksi.ksi_addr = (u_int32_t *)(intptr_t) fault_pc; 278 trapsignal(td, &ksi); 279 } 280 281 if ((fault_code & FAULT_USER) == 0) { 282 if (fault_instruction == KERNEL_BREAKPOINT) { 283#ifdef KDB 284 kdb_trap(T_BREAKPOINT, 0, frame); 285#else 286 printf("No debugger in kernel.\n"); 287#endif 288 return; 289 } else 290 panic("Undefined instruction in kernel.\n"); 291 } 292 293 userret(td, frame); 294} 295