linux/arch/mn10300/kernel/traps.c
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   1/* MN10300 Exception handling
   2 *
   3 * Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
   4 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   5 * Modified by David Howells (dhowells@redhat.com)
   6 *
   7 * This program is free software; you can redistribute it and/or
   8 * modify it under the terms of the GNU General Public Licence
   9 * as published by the Free Software Foundation; either version
  10 * 2 of the Licence, or (at your option) any later version.
  11 */
  12#include <linux/sched.h>
  13#include <linux/kernel.h>
  14#include <linux/string.h>
  15#include <linux/errno.h>
  16#include <linux/ptrace.h>
  17#include <linux/timer.h>
  18#include <linux/mm.h>
  19#include <linux/smp.h>
  20#include <linux/init.h>
  21#include <linux/delay.h>
  22#include <linux/spinlock.h>
  23#include <linux/interrupt.h>
  24#include <linux/kallsyms.h>
  25#include <linux/pci.h>
  26#include <linux/kdebug.h>
  27#include <linux/bug.h>
  28#include <linux/irq.h>
  29#include <asm/processor.h>
  30#include <asm/system.h>
  31#include <asm/uaccess.h>
  32#include <asm/io.h>
  33#include <asm/atomic.h>
  34#include <asm/smp.h>
  35#include <asm/pgalloc.h>
  36#include <asm/cacheflush.h>
  37#include <asm/cpu-regs.h>
  38#include <asm/busctl-regs.h>
  39#include <unit/leds.h>
  40#include <asm/fpu.h>
  41#include <asm/gdb-stub.h>
  42#include <asm/sections.h>
  43
  44#if (CONFIG_INTERRUPT_VECTOR_BASE & 0xffffff)
  45#error "INTERRUPT_VECTOR_BASE not aligned to 16MiB boundary!"
  46#endif
  47
  48struct pt_regs *__frame; /* current frame pointer */
  49EXPORT_SYMBOL(__frame);
  50
  51int kstack_depth_to_print = 24;
  52
  53spinlock_t die_lock = __SPIN_LOCK_UNLOCKED(die_lock);
  54
  55ATOMIC_NOTIFIER_HEAD(mn10300_die_chain);
  56
  57/*
  58 * These constants are for searching for possible module text
  59 * segments. MODULE_RANGE is a guess of how much space is likely
  60 * to be vmalloced.
  61 */
  62#define MODULE_RANGE (8 * 1024 * 1024)
  63
  64#define DO_ERROR(signr, prologue, str, name)                    \
  65asmlinkage void name(struct pt_regs *regs, u32 intcode)         \
  66{                                                               \
  67        prologue;                                               \
  68        if (die_if_no_fixup(str, regs, intcode))                \
  69                return;                                         \
  70        force_sig(signr, current);                              \
  71}
  72
  73#define DO_EINFO(signr, prologue, str, name, sicode)                    \
  74asmlinkage void name(struct pt_regs *regs, u32 intcode)                 \
  75{                                                                       \
  76        siginfo_t info;                                                 \
  77        prologue;                                                       \
  78        if (die_if_no_fixup(str, regs, intcode))                        \
  79                return;                                                 \
  80        info.si_signo = signr;                                          \
  81        if (signr == SIGILL && sicode == ILL_ILLOPC) {                  \
  82                uint8_t opcode;                                         \
  83                if (get_user(opcode, (uint8_t __user *)regs->pc) == 0)  \
  84                        if (opcode == 0xff)                             \
  85                                info.si_signo = SIGTRAP;                \
  86        }                                                               \
  87        info.si_errno = 0;                                              \
  88        info.si_code = sicode;                                          \
  89        info.si_addr = (void *) regs->pc;                               \
  90        force_sig_info(info.si_signo, &info, current);                  \
  91}
  92
  93DO_ERROR(SIGTRAP, {}, "trap",                   trap);
  94DO_ERROR(SIGSEGV, {}, "ibreak",                 ibreak);
  95DO_ERROR(SIGSEGV, {}, "obreak",                 obreak);
  96DO_EINFO(SIGSEGV, {}, "access error",           access_error,   SEGV_ACCERR);
  97DO_EINFO(SIGSEGV, {}, "insn access error",      insn_acc_error, SEGV_ACCERR);
  98DO_EINFO(SIGSEGV, {}, "data access error",      data_acc_error, SEGV_ACCERR);
  99DO_EINFO(SIGILL,  {}, "privileged opcode",      priv_op,        ILL_PRVOPC);
 100DO_EINFO(SIGILL,  {}, "invalid opcode",         invalid_op,     ILL_ILLOPC);
 101DO_EINFO(SIGILL,  {}, "invalid ex opcode",      invalid_exop,   ILL_ILLOPC);
 102DO_EINFO(SIGBUS,  {}, "invalid address",        mem_error,      BUS_ADRERR);
 103DO_EINFO(SIGBUS,  {}, "bus error",              bus_error,      BUS_ADRERR);
 104DO_EINFO(SIGILL,  {}, "FPU invalid opcode",     fpu_invalid_op, ILL_COPROC);
 105
 106DO_ERROR(SIGTRAP,
 107#ifndef CONFIG_MN10300_USING_JTAG
 108         DCR &= ~0x0001,
 109#else
 110         {},
 111#endif
 112         "single step", istep);
 113
 114/*
 115 * handle NMI
 116 */
 117asmlinkage void nmi(struct pt_regs *regs, enum exception_code code)
 118{
 119        /* see if gdbstub wants to deal with it */
 120#ifdef CONFIG_GDBSTUB
 121        if (gdbstub_intercept(regs, code))
 122                return;
 123#endif
 124
 125        printk(KERN_WARNING "--- Register Dump ---\n");
 126        show_registers(regs);
 127        printk(KERN_WARNING "---------------------\n");
 128}
 129
 130/*
 131 * show a stack trace from the specified stack pointer
 132 */
 133void show_trace(unsigned long *sp)
 134{
 135        unsigned long *stack, addr, module_start, module_end;
 136        int i;
 137
 138        printk(KERN_EMERG "\nCall Trace:");
 139
 140        stack = sp;
 141        i = 0;
 142        module_start = VMALLOC_START;
 143        module_end = VMALLOC_END;
 144
 145        while (((long) stack & (THREAD_SIZE - 1)) != 0) {
 146                addr = *stack++;
 147                if (__kernel_text_address(addr)) {
 148#if 1
 149                        printk(" [<%08lx>]", addr);
 150                        print_symbol(" %s", addr);
 151                        printk("\n");
 152#else
 153                        if ((i % 6) == 0)
 154                                printk(KERN_EMERG "  ");
 155                        printk("[<%08lx>] ", addr);
 156                        i++;
 157#endif
 158                }
 159        }
 160
 161        printk("\n");
 162}
 163
 164/*
 165 * show the raw stack from the specified stack pointer
 166 */
 167void show_stack(struct task_struct *task, unsigned long *sp)
 168{
 169        unsigned long *stack;
 170        int i;
 171
 172        if (!sp)
 173                sp = (unsigned long *) &sp;
 174
 175        stack = sp;
 176        printk(KERN_EMERG "Stack:");
 177        for (i = 0; i < kstack_depth_to_print; i++) {
 178                if (((long) stack & (THREAD_SIZE - 1)) == 0)
 179                        break;
 180                if ((i % 8) == 0)
 181                        printk(KERN_EMERG "  ");
 182                printk("%08lx ", *stack++);
 183        }
 184
 185        show_trace(sp);
 186}
 187
 188/*
 189 * the architecture-independent dump_stack generator
 190 */
 191void dump_stack(void)
 192{
 193        unsigned long stack;
 194
 195        show_stack(current, &stack);
 196}
 197EXPORT_SYMBOL(dump_stack);
 198
 199/*
 200 * dump the register file in the specified exception frame
 201 */
 202void show_registers_only(struct pt_regs *regs)
 203{
 204        unsigned long ssp;
 205
 206        ssp = (unsigned long) regs + sizeof(*regs);
 207
 208        printk(KERN_EMERG "PC:  %08lx EPSW:  %08lx  SSP: %08lx mode: %s\n",
 209               regs->pc, regs->epsw, ssp, user_mode(regs) ? "User" : "Super");
 210        printk(KERN_EMERG "d0:  %08lx   d1:  %08lx   d2: %08lx   d3: %08lx\n",
 211               regs->d0, regs->d1, regs->d2, regs->d3);
 212        printk(KERN_EMERG "a0:  %08lx   a1:  %08lx   a2: %08lx   a3: %08lx\n",
 213               regs->a0, regs->a1, regs->a2, regs->a3);
 214        printk(KERN_EMERG "e0:  %08lx   e1:  %08lx   e2: %08lx   e3: %08lx\n",
 215               regs->e0, regs->e1, regs->e2, regs->e3);
 216        printk(KERN_EMERG "e4:  %08lx   e5:  %08lx   e6: %08lx   e7: %08lx\n",
 217               regs->e4, regs->e5, regs->e6, regs->e7);
 218        printk(KERN_EMERG "lar: %08lx   lir: %08lx  mdr: %08lx  usp: %08lx\n",
 219               regs->lar, regs->lir, regs->mdr, regs->sp);
 220        printk(KERN_EMERG "cvf: %08lx   crl: %08lx  crh: %08lx  drq: %08lx\n",
 221               regs->mcvf, regs->mcrl, regs->mcrh, regs->mdrq);
 222        printk(KERN_EMERG "threadinfo=%p task=%p)\n",
 223               current_thread_info(), current);
 224
 225        if ((unsigned long) current >= 0x90000000UL &&
 226            (unsigned long) current < 0x94000000UL)
 227                printk(KERN_EMERG "Process %s (pid: %d)\n",
 228                       current->comm, current->pid);
 229
 230        printk(KERN_EMERG "CPUP:   %04hx\n", CPUP);
 231        printk(KERN_EMERG "TBR:    %08x\n", TBR);
 232        printk(KERN_EMERG "DEAR:   %08x\n", DEAR);
 233        printk(KERN_EMERG "sISR:   %08x\n", sISR);
 234        printk(KERN_EMERG "NMICR:  %04hx\n", NMICR);
 235        printk(KERN_EMERG "BCBERR: %08x\n", BCBERR);
 236        printk(KERN_EMERG "BCBEAR: %08x\n", BCBEAR);
 237        printk(KERN_EMERG "MMUFCR: %08x\n", MMUFCR);
 238        printk(KERN_EMERG "IPTEU : %08x  IPTEL2: %08x\n", IPTEU, IPTEL2);
 239        printk(KERN_EMERG "DPTEU:  %08x  DPTEL2: %08x\n", DPTEU, DPTEL2);
 240}
 241
 242/*
 243 * dump the registers and the stack
 244 */
 245void show_registers(struct pt_regs *regs)
 246{
 247        unsigned long sp;
 248        int i;
 249
 250        show_registers_only(regs);
 251
 252        if (!user_mode(regs))
 253                sp = (unsigned long) regs + sizeof(*regs);
 254        else
 255                sp = regs->sp;
 256
 257        /* when in-kernel, we also print out the stack and code at the
 258         * time of the fault..
 259         */
 260        if (!user_mode(regs)) {
 261                printk(KERN_EMERG "\n");
 262                show_stack(current, (unsigned long *) sp);
 263
 264#if 0
 265                printk(KERN_EMERG "\nCode: ");
 266                if (regs->pc < PAGE_OFFSET)
 267                        goto bad;
 268
 269                for (i = 0; i < 20; i++) {
 270                        unsigned char c;
 271                        if (__get_user(c, &((unsigned char *) regs->pc)[i]))
 272                                goto bad;
 273                        printk("%02x ", c);
 274                }
 275#else
 276                i = 0;
 277#endif
 278        }
 279
 280        printk("\n");
 281        return;
 282
 283#if 0
 284bad:
 285        printk(KERN_EMERG " Bad PC value.");
 286        break;
 287#endif
 288}
 289
 290/*
 291 *
 292 */
 293void show_trace_task(struct task_struct *tsk)
 294{
 295        unsigned long sp = tsk->thread.sp;
 296
 297        /* User space on another CPU? */
 298        if ((sp ^ (unsigned long) tsk) & (PAGE_MASK << 1))
 299                return;
 300
 301        show_trace((unsigned long *) sp);
 302}
 303
 304/*
 305 * note the untimely death of part of the kernel
 306 */
 307void die(const char *str, struct pt_regs *regs, enum exception_code code)
 308{
 309        console_verbose();
 310        spin_lock_irq(&die_lock);
 311        printk(KERN_EMERG "\n%s: %04x\n",
 312               str, code & 0xffff);
 313        show_registers(regs);
 314
 315        if (regs->pc >= 0x02000000 && regs->pc < 0x04000000 &&
 316            (regs->epsw & (EPSW_IM | EPSW_IE)) != (EPSW_IM | EPSW_IE)) {
 317                printk(KERN_EMERG "Exception in usermode interrupt handler\n");
 318                printk(KERN_EMERG "\nPlease connect to kernel debugger !!\n");
 319                asm volatile ("0: bra 0b");
 320        }
 321
 322        spin_unlock_irq(&die_lock);
 323        do_exit(SIGSEGV);
 324}
 325
 326/*
 327 * see if there's a fixup handler we can force a jump to when an exception
 328 * happens due to something kernel code did
 329 */
 330int die_if_no_fixup(const char *str, struct pt_regs *regs,
 331                    enum exception_code code)
 332{
 333        if (user_mode(regs))
 334                return 0;
 335
 336        peripheral_leds_display_exception(code);
 337
 338        switch (code) {
 339                /* see if we can fixup the kernel accessing memory */
 340        case EXCEP_ITLBMISS:
 341        case EXCEP_DTLBMISS:
 342        case EXCEP_IAERROR:
 343        case EXCEP_DAERROR:
 344        case EXCEP_MEMERR:
 345        case EXCEP_MISALIGN:
 346        case EXCEP_BUSERROR:
 347        case EXCEP_ILLDATACC:
 348        case EXCEP_IOINSACC:
 349        case EXCEP_PRIVINSACC:
 350        case EXCEP_PRIVDATACC:
 351        case EXCEP_DATINSACC:
 352                if (fixup_exception(regs))
 353                        return 1;
 354        case EXCEP_UNIMPINS:
 355                if (regs->pc && *(uint8_t *)regs->pc == 0xff)
 356                        if (notify_die(DIE_BREAKPOINT, str, regs, code, 0, 0))
 357                                return 1;
 358                break;
 359        default:
 360                break;
 361        }
 362
 363        /* see if gdbstub wants to deal with it */
 364#ifdef CONFIG_GDBSTUB
 365        if (gdbstub_intercept(regs, code))
 366                return 1;
 367#endif
 368
 369        if (notify_die(DIE_GPF, str, regs, code, 0, 0))
 370                return 1;
 371
 372        /* make the process die as the last resort */
 373        die(str, regs, code);
 374}
 375
 376/*
 377 * handle unsupported syscall instructions (syscall 1-15)
 378 */
 379static asmlinkage void unsupported_syscall(struct pt_regs *regs,
 380                                           enum exception_code code)
 381{
 382        struct task_struct *tsk = current;
 383        siginfo_t info;
 384
 385        /* catch a kernel BUG() */
 386        if (code == EXCEP_SYSCALL15 && !user_mode(regs)) {
 387                if (report_bug(regs->pc, regs) == BUG_TRAP_TYPE_BUG) {
 388#ifdef CONFIG_GDBSTUB
 389                        gdbstub_intercept(regs, code);
 390#endif
 391                }
 392        }
 393
 394        regs->pc -= 2; /* syscall return addr is _after_ the instruction */
 395
 396        die_if_no_fixup("An unsupported syscall insn was used by the kernel\n",
 397                        regs, code);
 398
 399        info.si_signo   = SIGILL;
 400        info.si_errno   = ENOSYS;
 401        info.si_code    = ILL_ILLTRP;
 402        info.si_addr    = (void *) regs->pc;
 403        force_sig_info(SIGILL, &info, tsk);
 404}
 405
 406/*
 407 * display the register file when the stack pointer gets clobbered
 408 */
 409asmlinkage void do_double_fault(struct pt_regs *regs)
 410{
 411        struct task_struct *tsk = current;
 412
 413        strcpy(tsk->comm, "emergency tsk");
 414        tsk->pid = 0;
 415        console_verbose();
 416        printk(KERN_EMERG "--- double fault ---\n");
 417        show_registers(regs);
 418}
 419
 420/*
 421 * asynchronous bus error (external, usually I/O DMA)
 422 */
 423asmlinkage void io_bus_error(u32 bcberr, u32 bcbear, struct pt_regs *regs)
 424{
 425        console_verbose();
 426
 427        printk(KERN_EMERG "Asynchronous I/O Bus Error\n");
 428        printk(KERN_EMERG "==========================\n");
 429
 430        if (bcberr & BCBERR_BEME)
 431                printk(KERN_EMERG "- Multiple recorded errors\n");
 432
 433        printk(KERN_EMERG "- Faulting Buses:%s%s%s\n",
 434               bcberr & BCBERR_BEMR_CI  ? " CPU-Ins-Fetch" : "",
 435               bcberr & BCBERR_BEMR_CD  ? " CPU-Data" : "",
 436               bcberr & BCBERR_BEMR_DMA ? " DMA" : "");
 437
 438        printk(KERN_EMERG "- %s %s access made to %s at address %08x\n",
 439               bcberr & BCBERR_BEBST ? "Burst" : "Single",
 440               bcberr & BCBERR_BERW ? "Read" : "Write",
 441               bcberr & BCBERR_BESB_MON  ? "Monitor Space" :
 442               bcberr & BCBERR_BESB_IO   ? "Internal CPU I/O Space" :
 443               bcberr & BCBERR_BESB_EX   ? "External I/O Bus" :
 444               bcberr & BCBERR_BESB_OPEX ? "External Memory Bus" :
 445               "On Chip Memory",
 446               bcbear
 447               );
 448
 449        printk(KERN_EMERG "- Detected by the %s\n",
 450               bcberr&BCBERR_BESD ? "Bus Control Unit" : "Slave Bus");
 451
 452#ifdef CONFIG_PCI
 453#define BRIDGEREGB(X) (*(volatile __u8  *)(0xBE040000 + (X)))
 454#define BRIDGEREGW(X) (*(volatile __u16 *)(0xBE040000 + (X)))
 455#define BRIDGEREGL(X) (*(volatile __u32 *)(0xBE040000 + (X)))
 456
 457        printk(KERN_EMERG "- PCI Memory Paging Reg:         %08x\n",
 458               *(volatile __u32 *) (0xBFFFFFF4));
 459        printk(KERN_EMERG "- PCI Bridge Base Address 0:     %08x\n",
 460               BRIDGEREGL(PCI_BASE_ADDRESS_0));
 461        printk(KERN_EMERG "- PCI Bridge AMPCI Base Address: %08x\n",
 462               BRIDGEREGL(0x48));
 463        printk(KERN_EMERG "- PCI Bridge Command:                %04hx\n",
 464               BRIDGEREGW(PCI_COMMAND));
 465        printk(KERN_EMERG "- PCI Bridge Status:                 %04hx\n",
 466               BRIDGEREGW(PCI_STATUS));
 467        printk(KERN_EMERG "- PCI Bridge Int Status:         %08hx\n",
 468               BRIDGEREGL(0x4c));
 469#endif
 470
 471        printk(KERN_EMERG "\n");
 472        show_registers(regs);
 473
 474        panic("Halted due to asynchronous I/O Bus Error\n");
 475}
 476
 477/*
 478 * handle an exception for which a handler has not yet been installed
 479 */
 480asmlinkage void uninitialised_exception(struct pt_regs *regs,
 481                                        enum exception_code code)
 482{
 483
 484        /* see if gdbstub wants to deal with it */
 485#ifdef CONFIG_GDBSTUB
 486        if (gdbstub_intercept(regs, code))
 487                return;
 488#endif
 489
 490        peripheral_leds_display_exception(code);
 491        printk(KERN_EMERG "Uninitialised Exception 0x%04x\n", code & 0xFFFF);
 492        show_registers(regs);
 493
 494        for (;;)
 495                continue;
 496}
 497
 498/*
 499 * set an interrupt stub to jump to a handler
 500 * ! NOTE: this does *not* flush the caches
 501 */
 502void __init __set_intr_stub(enum exception_code code, void *handler)
 503{
 504        unsigned long addr;
 505        u8 *vector = (u8 *)(CONFIG_INTERRUPT_VECTOR_BASE + code);
 506
 507        addr = (unsigned long) handler - (unsigned long) vector;
 508        vector[0] = 0xdc;               /* JMP handler */
 509        vector[1] = addr;
 510        vector[2] = addr >> 8;
 511        vector[3] = addr >> 16;
 512        vector[4] = addr >> 24;
 513        vector[5] = 0xcb;
 514        vector[6] = 0xcb;
 515        vector[7] = 0xcb;
 516}
 517
 518/*
 519 * set an interrupt stub to jump to a handler
 520 */
 521void __init set_intr_stub(enum exception_code code, void *handler)
 522{
 523        unsigned long addr;
 524        u8 *vector = (u8 *)(CONFIG_INTERRUPT_VECTOR_BASE + code);
 525
 526        addr = (unsigned long) handler - (unsigned long) vector;
 527        vector[0] = 0xdc;               /* JMP handler */
 528        vector[1] = addr;
 529        vector[2] = addr >> 8;
 530        vector[3] = addr >> 16;
 531        vector[4] = addr >> 24;
 532        vector[5] = 0xcb;
 533        vector[6] = 0xcb;
 534        vector[7] = 0xcb;
 535
 536        mn10300_dcache_flush_inv();
 537        mn10300_icache_inv();
 538}
 539
 540/*
 541 * set an interrupt stub to invoke the JTAG unit and then jump to a handler
 542 */
 543void __init set_jtag_stub(enum exception_code code, void *handler)
 544{
 545        unsigned long addr;
 546        u8 *vector = (u8 *)(CONFIG_INTERRUPT_VECTOR_BASE + code);
 547
 548        addr = (unsigned long) handler - ((unsigned long) vector + 1);
 549        vector[0] = 0xff;               /* PI to jump into JTAG debugger */
 550        vector[1] = 0xdc;               /* jmp handler */
 551        vector[2] = addr;
 552        vector[3] = addr >> 8;
 553        vector[4] = addr >> 16;
 554        vector[5] = addr >> 24;
 555        vector[6] = 0xcb;
 556        vector[7] = 0xcb;
 557
 558        mn10300_dcache_flush_inv();
 559        flush_icache_range((unsigned long) vector, (unsigned long) vector + 8);
 560}
 561
 562/*
 563 * initialise the exception table
 564 */
 565void __init trap_init(void)
 566{
 567        set_excp_vector(EXCEP_TRAP,             trap);
 568        set_excp_vector(EXCEP_ISTEP,            istep);
 569        set_excp_vector(EXCEP_IBREAK,           ibreak);
 570        set_excp_vector(EXCEP_OBREAK,           obreak);
 571
 572        set_excp_vector(EXCEP_PRIVINS,          priv_op);
 573        set_excp_vector(EXCEP_UNIMPINS,         invalid_op);
 574        set_excp_vector(EXCEP_UNIMPEXINS,       invalid_exop);
 575        set_excp_vector(EXCEP_MEMERR,           mem_error);
 576        set_excp_vector(EXCEP_MISALIGN,         misalignment);
 577        set_excp_vector(EXCEP_BUSERROR,         bus_error);
 578        set_excp_vector(EXCEP_ILLINSACC,        insn_acc_error);
 579        set_excp_vector(EXCEP_ILLDATACC,        data_acc_error);
 580        set_excp_vector(EXCEP_IOINSACC,         insn_acc_error);
 581        set_excp_vector(EXCEP_PRIVINSACC,       insn_acc_error);
 582        set_excp_vector(EXCEP_PRIVDATACC,       data_acc_error);
 583        set_excp_vector(EXCEP_DATINSACC,        insn_acc_error);
 584        set_excp_vector(EXCEP_FPU_DISABLED,     fpu_disabled);
 585        set_excp_vector(EXCEP_FPU_UNIMPINS,     fpu_invalid_op);
 586        set_excp_vector(EXCEP_FPU_OPERATION,    fpu_exception);
 587
 588        set_excp_vector(EXCEP_NMI,              nmi);
 589
 590        set_excp_vector(EXCEP_SYSCALL1,         unsupported_syscall);
 591        set_excp_vector(EXCEP_SYSCALL2,         unsupported_syscall);
 592        set_excp_vector(EXCEP_SYSCALL3,         unsupported_syscall);
 593        set_excp_vector(EXCEP_SYSCALL4,         unsupported_syscall);
 594        set_excp_vector(EXCEP_SYSCALL5,         unsupported_syscall);
 595        set_excp_vector(EXCEP_SYSCALL6,         unsupported_syscall);
 596        set_excp_vector(EXCEP_SYSCALL7,         unsupported_syscall);
 597        set_excp_vector(EXCEP_SYSCALL8,         unsupported_syscall);
 598        set_excp_vector(EXCEP_SYSCALL9,         unsupported_syscall);
 599        set_excp_vector(EXCEP_SYSCALL10,        unsupported_syscall);
 600        set_excp_vector(EXCEP_SYSCALL11,        unsupported_syscall);
 601        set_excp_vector(EXCEP_SYSCALL12,        unsupported_syscall);
 602        set_excp_vector(EXCEP_SYSCALL13,        unsupported_syscall);
 603        set_excp_vector(EXCEP_SYSCALL14,        unsupported_syscall);
 604        set_excp_vector(EXCEP_SYSCALL15,        unsupported_syscall);
 605}
 606
 607/*
 608 * determine if a program counter value is a valid bug address
 609 */
 610int is_valid_bugaddr(unsigned long pc)
 611{
 612        return pc >= PAGE_OFFSET;
 613}
 614