arch/openrisc/kernel/traps.c

   1 /*
   2  * OpenRISC traps.c
   3  *
   4  * Linux architectural port borrowing liberally from similar works of
   5  * others.  All original copyrights apply as per the original source
   6  * declaration.
   7  *
   8  * Modifications for the OpenRISC architecture:
   9  * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
  10  * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
  11  *
  12  *      This program is free software; you can redistribute it and/or
  13  *      modify it under the terms of the GNU General Public License
  14  *      as published by the Free Software Foundation; either version
  15  *      2 of the License, or (at your option) any later version.
  16  *
  17  *  Here we handle the break vectors not used by the system call
  18  *  mechanism, as well as some general stack/register dumping
  19  *  things.
  20  *
  21  */
  22
  23 #include <linux/init.h>
  24 #include <linux/sched.h>
  25 #include <linux/kernel.h>
  26 #include <linux/extable.h>
  27 #include <linux/kmod.h>
  28 #include <linux/string.h>
  29 #include <linux/errno.h>
  30 #include <linux/ptrace.h>
  31 #include <linux/timer.h>
  32 #include <linux/mm.h>
  33 #include <linux/kallsyms.h>
  34 #include <linux/uaccess.h>
  35
  36 #include <asm/segment.h>
  37 #include <asm/io.h>
  38 #include <asm/pgtable.h>
  39
  40 extern char _etext, _stext;
  41
  42 int kstack_depth_to_print = 0x180;
  43 int lwa_flag;
  44 unsigned long __user *lwa_addr;
  45
  46 static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
  47 {
  48         return p > (void *)tinfo && p < (void *)tinfo + THREAD_SIZE - 3;
  49 }
  50
  51 void show_trace(struct task_struct *task, unsigned long *stack)
  52 {
  53         struct thread_info *context;
  54         unsigned long addr;
  55
  56         context = (struct thread_info *)
  57             ((unsigned long)stack & (~(THREAD_SIZE - 1)));
  58
  59         while (valid_stack_ptr(context, stack)) {
  60                 addr = *stack++;
  61                 if (__kernel_text_address(addr)) {
  62                         printk(" [<%08lx>]", addr);
  63                         print_symbol(" %s", addr);
  64                         printk("\n");
  65                 }
  66         }
  67         printk(" =======================\n");
  68 }
  69
  70 /* displays a short stack trace */
  71 void show_stack(struct task_struct *task, unsigned long *esp)
  72 {
  73         unsigned long addr, *stack;
  74         int i;
  75
  76         if (esp == NULL)
  77                 esp = (unsigned long *)&esp;
  78
  79         stack = esp;
  80
  81         printk("Stack dump [0x%08lx]:\n", (unsigned long)esp);
  82         for (i = 0; i < kstack_depth_to_print; i++) {
  83                 if (kstack_end(stack))
  84                         break;
  85                 if (__get_user(addr, stack)) {
  86                         /* This message matches "failing address" marked
  87                            s390 in ksymoops, so lines containing it will
  88                            not be filtered out by ksymoops.  */
  89                         printk("Failing address 0x%lx\n", (unsigned long)stack);
  90                         break;
  91                 }
  92                 stack++;
  93
  94                 printk("sp + %02d: 0x%08lx\n", i * 4, addr);
  95         }
  96         printk("\n");
  97
  98         show_trace(task, esp);
  99
 100         return;
 101 }
 102
 103 void show_trace_task(struct task_struct *tsk)
 104 {
 105         /*
 106          * TODO: SysRq-T trace dump...
 107          */
 108 }
 109
 110 void show_registers(struct pt_regs *regs)
 111 {
 112         int i;
 113         int in_kernel = 1;
 114         unsigned long esp;
 115
 116         esp = (unsigned long)(&regs->sp);
 117         if (user_mode(regs))
 118                 in_kernel = 0;
 119
 120         printk("CPU #: %d\n"
 121                "   PC: %08lx    SR: %08lx    SP: %08lx\n",
 122                smp_processor_id(), regs->pc, regs->sr, regs->sp);
 123         printk("GPR00: %08lx GPR01: %08lx GPR02: %08lx GPR03: %08lx\n",
 124                0L, regs->gpr[1], regs->gpr[2], regs->gpr[3]);
 125         printk("GPR04: %08lx GPR05: %08lx GPR06: %08lx GPR07: %08lx\n",
 126                regs->gpr[4], regs->gpr[5], regs->gpr[6], regs->gpr[7]);
 127         printk("GPR08: %08lx GPR09: %08lx GPR10: %08lx GPR11: %08lx\n",
 128                regs->gpr[8], regs->gpr[9], regs->gpr[10], regs->gpr[11]);
 129         printk("GPR12: %08lx GPR13: %08lx GPR14: %08lx GPR15: %08lx\n",
 130                regs->gpr[12], regs->gpr[13], regs->gpr[14], regs->gpr[15]);
 131         printk("GPR16: %08lx GPR17: %08lx GPR18: %08lx GPR19: %08lx\n",
 132                regs->gpr[16], regs->gpr[17], regs->gpr[18], regs->gpr[19]);
 133         printk("GPR20: %08lx GPR21: %08lx GPR22: %08lx GPR23: %08lx\n",
 134                regs->gpr[20], regs->gpr[21], regs->gpr[22], regs->gpr[23]);
 135         printk("GPR24: %08lx GPR25: %08lx GPR26: %08lx GPR27: %08lx\n",
 136                regs->gpr[24], regs->gpr[25], regs->gpr[26], regs->gpr[27]);
 137         printk("GPR28: %08lx GPR29: %08lx GPR30: %08lx GPR31: %08lx\n",
 138                regs->gpr[28], regs->gpr[29], regs->gpr[30], regs->gpr[31]);
 139         printk("  RES: %08lx oGPR11: %08lx\n",
 140                regs->gpr[11], regs->orig_gpr11);
 141
 142         printk("Process %s (pid: %d, stackpage=%08lx)\n",
 143                current->comm, current->pid, (unsigned long)current);
 144         /*
 145          * When in-kernel, we also print out the stack and code at the
 146          * time of the fault..
 147          */
 148         if (in_kernel) {
 149
 150                 printk("\nStack: ");
 151                 show_stack(NULL, (unsigned long *)esp);
 152
 153                 printk("\nCode: ");
 154                 if (regs->pc < PAGE_OFFSET)
 155                         goto bad;
 156
 157                 for (i = -24; i < 24; i++) {
 158                         unsigned char c;
 159                         if (__get_user(c, &((unsigned char *)regs->pc)[i])) {
 160 bad:
 161                                 printk(" Bad PC value.");
 162                                 break;
 163                         }
 164
 165                         if (i == 0)
 166                                 printk("(%02x) ", c);
 167                         else
 168                                 printk("%02x ", c);
 169                 }
 170         }
 171         printk("\n");
 172 }
 173
 174 void nommu_dump_state(struct pt_regs *regs,
 175                       unsigned long ea, unsigned long vector)
 176 {
 177         int i;
 178         unsigned long addr, stack = regs->sp;
 179
 180         printk("\n\r[nommu_dump_state] :: ea %lx, vector %lx\n\r", ea, vector);
 181
 182         printk("CPU #: %d\n"
 183                "   PC: %08lx    SR: %08lx    SP: %08lx\n",
 184                0, regs->pc, regs->sr, regs->sp);
 185         printk("GPR00: %08lx GPR01: %08lx GPR02: %08lx GPR03: %08lx\n",
 186                0L, regs->gpr[1], regs->gpr[2], regs->gpr[3]);
 187         printk("GPR04: %08lx GPR05: %08lx GPR06: %08lx GPR07: %08lx\n",
 188                regs->gpr[4], regs->gpr[5], regs->gpr[6], regs->gpr[7]);
 189         printk("GPR08: %08lx GPR09: %08lx GPR10: %08lx GPR11: %08lx\n",
 190                regs->gpr[8], regs->gpr[9], regs->gpr[10], regs->gpr[11]);
 191         printk("GPR12: %08lx GPR13: %08lx GPR14: %08lx GPR15: %08lx\n",
 192                regs->gpr[12], regs->gpr[13], regs->gpr[14], regs->gpr[15]);
 193         printk("GPR16: %08lx GPR17: %08lx GPR18: %08lx GPR19: %08lx\n",
 194                regs->gpr[16], regs->gpr[17], regs->gpr[18], regs->gpr[19]);
 195         printk("GPR20: %08lx GPR21: %08lx GPR22: %08lx GPR23: %08lx\n",
 196                regs->gpr[20], regs->gpr[21], regs->gpr[22], regs->gpr[23]);
 197         printk("GPR24: %08lx GPR25: %08lx GPR26: %08lx GPR27: %08lx\n",
 198                regs->gpr[24], regs->gpr[25], regs->gpr[26], regs->gpr[27]);
 199         printk("GPR28: %08lx GPR29: %08lx GPR30: %08lx GPR31: %08lx\n",
 200                regs->gpr[28], regs->gpr[29], regs->gpr[30], regs->gpr[31]);
 201         printk("  RES: %08lx oGPR11: %08lx\n",
 202                regs->gpr[11], regs->orig_gpr11);
 203
 204         printk("Process %s (pid: %d, stackpage=%08lx)\n",
 205                ((struct task_struct *)(__pa(current)))->comm,
 206                ((struct task_struct *)(__pa(current)))->pid,
 207                (unsigned long)current);
 208
 209         printk("\nStack: ");
 210         printk("Stack dump [0x%08lx]:\n", (unsigned long)stack);
 211         for (i = 0; i < kstack_depth_to_print; i++) {
 212                 if (((long)stack & (THREAD_SIZE - 1)) == 0)
 213                         break;
 214                 stack++;
 215
 216                 printk("%lx :: sp + %02d: 0x%08lx\n", stack, i * 4,
 217                        *((unsigned long *)(__pa(stack))));
 218         }
 219         printk("\n");
 220
 221         printk("Call Trace:   ");
 222         i = 1;
 223         while (((long)stack & (THREAD_SIZE - 1)) != 0) {
 224                 addr = *((unsigned long *)__pa(stack));
 225                 stack++;
 226
 227                 if (kernel_text_address(addr)) {
 228                         if (i && ((i % 6) == 0))
 229                                 printk("\n ");
 230                         printk(" [<%08lx>]", addr);
 231                         i++;
 232                 }
 233         }
 234         printk("\n");
 235
 236         printk("\nCode: ");
 237
 238         for (i = -24; i < 24; i++) {
 239                 unsigned char c;
 240                 c = ((unsigned char *)(__pa(regs->pc)))[i];
 241
 242                 if (i == 0)
 243                         printk("(%02x) ", c);
 244                 else
 245                         printk("%02x ", c);
 246         }
 247         printk("\n");
 248 }
 249
 250 /* This is normally the 'Oops' routine */
 251 void die(const char *str, struct pt_regs *regs, long err)
 252 {
 253
 254         console_verbose();
 255         printk("\n%s#: %04lx\n", str, err & 0xffff);
 256         show_registers(regs);
 257 #ifdef CONFIG_JUMP_UPON_UNHANDLED_EXCEPTION
 258         printk("\n\nUNHANDLED_EXCEPTION: entering infinite loop\n");
 259
 260         /* shut down interrupts */
 261         local_irq_disable();
 262
 263         __asm__ __volatile__("l.nop   1");
 264         do {} while (1);
 265 #endif
 266         do_exit(SIGSEGV);
 267 }
 268
 269 /* This is normally the 'Oops' routine */
 270 void die_if_kernel(const char *str, struct pt_regs *regs, long err)
 271 {
 272         if (user_mode(regs))
 273                 return;
 274
 275         die(str, regs, err);
 276 }
 277
 278 void unhandled_exception(struct pt_regs *regs, int ea, int vector)
 279 {
 280         printk("Unable to handle exception at EA =0x%x, vector 0x%x",
 281                ea, vector);
 282         die("Oops", regs, 9);
 283 }
 284
 285 void __init trap_init(void)
 286 {
 287         /* Nothing needs to be done */
 288 }
 289
 290 asmlinkage void do_trap(struct pt_regs *regs, unsigned long address)
 291 {
 292         siginfo_t info;
 293         memset(&info, 0, sizeof(info));
 294         info.si_signo = SIGTRAP;
 295         info.si_code = TRAP_TRACE;
 296         info.si_addr = (void *)address;
 297         force_sig_info(SIGTRAP, &info, current);
 298
 299         regs->pc += 4;
 300 }
 301
 302 asmlinkage void do_unaligned_access(struct pt_regs *regs, unsigned long address)
 303 {
 304         siginfo_t info;
 305
 306         if (user_mode(regs)) {
 307                 /* Send a SIGSEGV */
 308                 info.si_signo = SIGSEGV;
 309                 info.si_errno = 0;
 310                 /* info.si_code has been set above */
 311                 info.si_addr = (void *)address;
 312                 force_sig_info(SIGSEGV, &info, current);
 313         } else {
 314                 printk("KERNEL: Unaligned Access 0x%.8lx\n", address);
 315                 show_registers(regs);
 316                 die("Die:", regs, address);
 317         }
 318
 319 }
 320
 321 asmlinkage void do_bus_fault(struct pt_regs *regs, unsigned long address)
 322 {
 323         siginfo_t info;
 324
 325         if (user_mode(regs)) {
 326                 /* Send a SIGBUS */
 327                 info.si_signo = SIGBUS;
 328                 info.si_errno = 0;
 329                 info.si_code = BUS_ADRERR;
 330                 info.si_addr = (void *)address;
 331                 force_sig_info(SIGBUS, &info, current);
 332         } else {                /* Kernel mode */
 333                 printk("KERNEL: Bus error (SIGBUS) 0x%.8lx\n", address);
 334                 show_registers(regs);
 335                 die("Die:", regs, address);
 336         }
 337 }
 338
 339 static inline int in_delay_slot(struct pt_regs *regs)
 340 {
 341 #ifdef CONFIG_OPENRISC_NO_SPR_SR_DSX
 342         /* No delay slot flag, do the old way */
 343         unsigned int op, insn;
 344
 345         insn = *((unsigned int *)regs->pc);
 346         op = insn >> 26;
 347         switch (op) {
 348         case 0x00: /* l.j */
 349         case 0x01: /* l.jal */
 350         case 0x03: /* l.bnf */
 351         case 0x04: /* l.bf */
 352         case 0x11: /* l.jr */
 353         case 0x12: /* l.jalr */
 354                 return 1;
 355         default:
 356                 return 0;
 357         }
 358 #else
 359         return regs->sr & SPR_SR_DSX;
 360 #endif
 361 }
 362
 363 static inline void adjust_pc(struct pt_regs *regs, unsigned long address)
 364 {
 365         int displacement;
 366         unsigned int rb, op, jmp;
 367
 368         if (unlikely(in_delay_slot(regs))) {
 369                 /* In delay slot, instruction at pc is a branch, simulate it */
 370                 jmp = *((unsigned int *)regs->pc);
 371
 372                 displacement = sign_extend32(((jmp) & 0x3ffffff) << 2, 27);
 373                 rb = (jmp & 0x0000ffff) >> 11;
 374                 op = jmp >> 26;
 375
 376                 switch (op) {
 377                 case 0x00: /* l.j */
 378                         regs->pc += displacement;
 379                         return;
 380                 case 0x01: /* l.jal */
 381                         regs->pc += displacement;
 382                         regs->gpr[9] = regs->pc + 8;
 383                         return;
 384                 case 0x03: /* l.bnf */
 385                         if (regs->sr & SPR_SR_F)
 386                                 regs->pc += 8;
 387                         else
 388                                 regs->pc += displacement;
 389                         return;
 390                 case 0x04: /* l.bf */
 391                         if (regs->sr & SPR_SR_F)
 392                                 regs->pc += displacement;
 393                         else
 394                                 regs->pc += 8;
 395                         return;
 396                 case 0x11: /* l.jr */
 397                         regs->pc = regs->gpr[rb];
 398                         return;
 399                 case 0x12: /* l.jalr */
 400                         regs->pc = regs->gpr[rb];
 401                         regs->gpr[9] = regs->pc + 8;
 402                         return;
 403                 default:
 404                         break;
 405                 }
 406         } else {
 407                 regs->pc += 4;
 408         }
 409 }
 410
 411 static inline void simulate_lwa(struct pt_regs *regs, unsigned long address,
 412                                 unsigned int insn)
 413 {
 414         unsigned int ra, rd;
 415         unsigned long value;
 416         unsigned long orig_pc;
 417         long imm;
 418
 419         const struct exception_table_entry *entry;
 420
 421         orig_pc = regs->pc;
 422         adjust_pc(regs, address);
 423
 424         ra = (insn >> 16) & 0x1f;
 425         rd = (insn >> 21) & 0x1f;
 426         imm = (short)insn;
 427         lwa_addr = (unsigned long __user *)(regs->gpr[ra] + imm);
 428
 429         if ((unsigned long)lwa_addr & 0x3) {
 430                 do_unaligned_access(regs, address);
 431                 return;
 432         }
 433
 434         if (get_user(value, lwa_addr)) {
 435                 if (user_mode(regs)) {
 436                         force_sig(SIGSEGV, current);
 437                         return;
 438                 }
 439
 440                 if ((entry = search_exception_tables(orig_pc))) {
 441                         regs->pc = entry->fixup;
 442                         return;
 443                 }
 444
 445                 /* kernel access in kernel space, load it directly */
 446                 value = *((unsigned long *)lwa_addr);
 447         }
 448
 449         lwa_flag = 1;
 450         regs->gpr[rd] = value;
 451 }
 452
 453 static inline void simulate_swa(struct pt_regs *regs, unsigned long address,
 454                                 unsigned int insn)
 455 {
 456         unsigned long __user *vaddr;
 457         unsigned long orig_pc;
 458         unsigned int ra, rb;
 459         long imm;
 460
 461         const struct exception_table_entry *entry;
 462
 463         orig_pc = regs->pc;
 464         adjust_pc(regs, address);
 465
 466         ra = (insn >> 16) & 0x1f;
 467         rb = (insn >> 11) & 0x1f;
 468         imm = (short)(((insn & 0x2200000) >> 10) | (insn & 0x7ff));
 469         vaddr = (unsigned long __user *)(regs->gpr[ra] + imm);
 470
 471         if (!lwa_flag || vaddr != lwa_addr) {
 472                 regs->sr &= ~SPR_SR_F;
 473                 return;
 474         }
 475
 476         if ((unsigned long)vaddr & 0x3) {
 477                 do_unaligned_access(regs, address);
 478                 return;
 479         }
 480
 481         if (put_user(regs->gpr[rb], vaddr)) {
 482                 if (user_mode(regs)) {
 483                         force_sig(SIGSEGV, current);
 484                         return;
 485                 }
 486
 487                 if ((entry = search_exception_tables(orig_pc))) {
 488                         regs->pc = entry->fixup;
 489                         return;
 490                 }
 491
 492                 /* kernel access in kernel space, store it directly */
 493                 *((unsigned long *)vaddr) = regs->gpr[rb];
 494         }
 495
 496         lwa_flag = 0;
 497         regs->sr |= SPR_SR_F;
 498 }
 499
 500 #define INSN_LWA        0x1b
 501 #define INSN_SWA        0x33
 502
 503 asmlinkage void do_illegal_instruction(struct pt_regs *regs,
 504                                        unsigned long address)
 505 {
 506         siginfo_t info;
 507         unsigned int op;
 508         unsigned int insn = *((unsigned int *)address);
 509
 510         op = insn >> 26;
 511
 512         switch (op) {
 513         case INSN_LWA:
 514                 simulate_lwa(regs, address, insn);
 515                 return;
 516
 517         case INSN_SWA:
 518                 simulate_swa(regs, address, insn);
 519                 return;
 520
 521         default:
 522                 break;
 523         }
 524
 525         if (user_mode(regs)) {
 526                 /* Send a SIGILL */
 527                 info.si_signo = SIGILL;
 528                 info.si_errno = 0;
 529                 info.si_code = ILL_ILLOPC;
 530                 info.si_addr = (void *)address;
 531                 force_sig_info(SIGBUS, &info, current);
 532         } else {                /* Kernel mode */
 533                 printk("KERNEL: Illegal instruction (SIGILL) 0x%.8lx\n",
 534                        address);
 535                 show_registers(regs);
 536                 die("Die:", regs, address);
 537         }
 538 }