linux-bk/arch/parisc/kernel/traps.c
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   1/*
   2 *  linux/arch/parisc/traps.c
   3 *
   4 *  Copyright (C) 1991, 1992  Linus Torvalds
   5 *  Copyright (C) 1999, 2000  Philipp Rumpf <prumpf@tux.org>
   6 */
   7
   8/*
   9 * 'Traps.c' handles hardware traps and faults after we have saved some
  10 * state in 'asm.s'.
  11 */
  12
  13#include <linux/config.h>
  14#include <linux/sched.h>
  15#include <linux/kernel.h>
  16#include <linux/string.h>
  17#include <linux/errno.h>
  18#include <linux/ptrace.h>
  19#include <linux/timer.h>
  20#include <linux/mm.h>
  21#include <linux/module.h>
  22#include <linux/smp.h>
  23#include <linux/smp_lock.h>
  24#include <linux/spinlock.h>
  25#include <linux/init.h>
  26#include <linux/interrupt.h>
  27#include <linux/console.h>
  28#include <linux/kallsyms.h>
  29
  30#include <asm/assembly.h>
  31#include <asm/system.h>
  32#include <asm/uaccess.h>
  33#include <asm/io.h>
  34#include <asm/irq.h>
  35#include <asm/traps.h>
  36#include <asm/unaligned.h>
  37#include <asm/atomic.h>
  38#include <asm/smp.h>
  39#include <asm/pdc.h>
  40#include <asm/pdc_chassis.h>
  41#include <asm/unwind.h>
  42
  43#include "../math-emu/math-emu.h"       /* for handle_fpe() */
  44
  45#define PRINT_USER_FAULTS /* (turn this on if you want user faults to be */
  46                          /*  dumped to the console via printk)          */
  47
  48#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
  49DEFINE_SPINLOCK(pa_dbit_lock);
  50#endif
  51
  52int printbinary(char *buf, unsigned long x, int nbits)
  53{
  54        unsigned long mask = 1UL << (nbits - 1);
  55        while (mask != 0) {
  56                *buf++ = (mask & x ? '1' : '0');
  57                mask >>= 1;
  58        }
  59        *buf = '\0';
  60
  61        return nbits;
  62}
  63
  64#ifdef __LP64__
  65#define RFMT "%016lx"
  66#else
  67#define RFMT "%08lx"
  68#endif
  69
  70void show_regs(struct pt_regs *regs)
  71{
  72        int i;
  73        char buf[128], *p;
  74        char *level;
  75        unsigned long cr30;
  76        unsigned long cr31;
  77
  78        level = user_mode(regs) ? KERN_DEBUG : KERN_CRIT;
  79
  80        printk("%s\n", level); /* don't want to have that pretty register dump messed up */
  81
  82        printk("%s     YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI\n", level);
  83        printbinary(buf, regs->gr[0], 32);
  84        printk("%sPSW: %s %s\n", level, buf, print_tainted());
  85
  86        for (i = 0; i < 32; i += 4) {
  87                int j;
  88                p = buf;
  89                p += sprintf(p, "%sr%02d-%02d ", level, i, i + 3);
  90                for (j = 0; j < 4; j++) {
  91                        p += sprintf(p, " " RFMT, (i+j) == 0 ? 0 : regs->gr[i + j]);
  92                }
  93                printk("%s\n", buf);
  94        }
  95
  96        for (i = 0; i < 8; i += 4) {
  97                int j;
  98                p = buf;
  99                p += sprintf(p, "%ssr%d-%d  ", level, i, i + 3);
 100                for (j = 0; j < 4; j++) {
 101                        p += sprintf(p, " " RFMT, regs->sr[i + j]);
 102                }
 103                printk("%s\n", buf);
 104        }
 105
 106#if RIDICULOUSLY_VERBOSE
 107        for (i = 0; i < 32; i += 2)
 108                printk("%sFR%02d : %016lx  FR%2d : %016lx", level, i,
 109                                regs->fr[i], i+1, regs->fr[i+1]);
 110#endif
 111
 112        cr30 = mfctl(30);
 113        cr31 = mfctl(31);
 114        printk("%s\n", level);
 115        printk("%sIASQ: " RFMT " " RFMT " IAOQ: " RFMT " " RFMT "\n",
 116               level, regs->iasq[0], regs->iasq[1], regs->iaoq[0], regs->iaoq[1]);
 117        printk("%s IIR: %08lx    ISR: " RFMT "  IOR: " RFMT "\n",
 118               level, regs->iir, regs->isr, regs->ior);
 119        printk("%s CPU: %8d   CR30: " RFMT " CR31: " RFMT "\n",
 120               level, current_thread_info()->cpu, cr30, cr31);
 121        printk("%s ORIG_R28: " RFMT "\n", level, regs->orig_r28);
 122        printk(level);
 123        print_symbol(" IAOQ[0]: %s\n", regs->iaoq[0]);
 124        printk(level);
 125        print_symbol(" IAOQ[1]: %s\n", regs->iaoq[1]);
 126        printk(level);
 127        print_symbol(" RP(r2): %s\n", regs->gr[2]);
 128}
 129
 130
 131void dump_stack(void)
 132{
 133        show_stack(NULL, NULL);
 134}
 135
 136EXPORT_SYMBOL(dump_stack);
 137
 138static void do_show_stack(struct unwind_frame_info *info)
 139{
 140        int i = 1;
 141
 142        printk("Backtrace:\n");
 143        while (i <= 16) {
 144                if (unwind_once(info) < 0 || info->ip == 0)
 145                        break;
 146
 147                if (__kernel_text_address(info->ip)) {
 148                        printk(" [<" RFMT ">] ", info->ip);
 149#ifdef CONFIG_KALLSYMS
 150                        print_symbol("%s\n", info->ip);
 151#else
 152                        if ((i & 0x03) == 0)
 153                                printk("\n");
 154#endif
 155                        i++;
 156                }
 157        }
 158        printk("\n");
 159}
 160
 161void show_stack(struct task_struct *task, unsigned long *s)
 162{
 163        struct unwind_frame_info info;
 164
 165        if (!task) {
 166                unsigned long sp, ip, rp;
 167
 168HERE:
 169                asm volatile ("copy %%r30, %0" : "=r"(sp));
 170                ip = (unsigned long)&&HERE;
 171                rp = (unsigned long)__builtin_return_address(0);
 172                unwind_frame_init(&info, current, sp, ip, rp);
 173        } else {
 174                unwind_frame_init_from_blocked_task(&info, task);
 175        }
 176
 177        do_show_stack(&info);
 178}
 179
 180void die_if_kernel(char *str, struct pt_regs *regs, long err)
 181{
 182        if (user_mode(regs)) {
 183                if (err == 0)
 184                        return; /* STFU */
 185
 186                printk(KERN_CRIT "%s (pid %d): %s (code %ld) at " RFMT "\n",
 187                        current->comm, current->pid, str, err, regs->iaoq[0]);
 188#ifdef PRINT_USER_FAULTS
 189                /* XXX for debugging only */
 190                show_regs(regs);
 191#endif
 192                return;
 193        }
 194
 195        oops_in_progress = 1;
 196
 197        /* Amuse the user in a SPARC fashion */
 198        printk(
 199"      _______________________________ \n"
 200"     < Your System ate a SPARC! Gah! >\n"
 201"      ------------------------------- \n"
 202"             \\   ^__^\n"
 203"              \\  (xx)\\_______\n"
 204"                 (__)\\       )\\/\\\n"
 205"                  U  ||----w |\n"
 206"                     ||     ||\n");
 207        
 208        /* unlock the pdc lock if necessary */
 209        pdc_emergency_unlock();
 210
 211        /* maybe the kernel hasn't booted very far yet and hasn't been able 
 212         * to initialize the serial or STI console. In that case we should 
 213         * re-enable the pdc console, so that the user will be able to 
 214         * identify the problem. */
 215        if (!console_drivers)
 216                pdc_console_restart();
 217        
 218        printk(KERN_CRIT "%s (pid %d): %s (code %ld)\n",
 219                current->comm, current->pid, str, err);
 220        show_regs(regs);
 221
 222        /* Wot's wrong wif bein' racy? */
 223        if (current->thread.flags & PARISC_KERNEL_DEATH) {
 224                printk(KERN_CRIT "%s() recursion detected.\n", __FUNCTION__);
 225                local_irq_enable();
 226                while (1);
 227        }
 228
 229        current->thread.flags |= PARISC_KERNEL_DEATH;
 230        do_exit(SIGSEGV);
 231}
 232
 233int syscall_ipi(int (*syscall) (struct pt_regs *), struct pt_regs *regs)
 234{
 235        return syscall(regs);
 236}
 237
 238/* gdb uses break 4,8 */
 239#define GDB_BREAK_INSN 0x10004
 240void handle_gdb_break(struct pt_regs *regs, int wot)
 241{
 242        struct siginfo si;
 243
 244        si.si_code = wot;
 245        si.si_addr = (void *) (regs->iaoq[0] & ~3);
 246        si.si_signo = SIGTRAP;
 247        si.si_errno = 0;
 248        force_sig_info(SIGTRAP, &si, current);
 249}
 250
 251void handle_break(unsigned iir, struct pt_regs *regs)
 252{
 253        struct siginfo si;
 254
 255        switch(iir) {
 256        case 0x00:
 257#ifdef PRINT_USER_FAULTS
 258                printk(KERN_DEBUG "break 0,0: pid=%d command='%s'\n",
 259                       current->pid, current->comm);
 260#endif
 261                die_if_kernel("Breakpoint", regs, 0);
 262#ifdef PRINT_USER_FAULTS
 263                show_regs(regs);
 264#endif
 265                si.si_code = TRAP_BRKPT;
 266                si.si_addr = (void *) (regs->iaoq[0] & ~3);
 267                si.si_signo = SIGTRAP;
 268                force_sig_info(SIGTRAP, &si, current);
 269                break;
 270
 271        case GDB_BREAK_INSN:
 272                die_if_kernel("Breakpoint", regs, 0);
 273                handle_gdb_break(regs, TRAP_BRKPT);
 274                break;
 275
 276        default:
 277#ifdef PRINT_USER_FAULTS
 278                printk(KERN_DEBUG "break %#08x: pid=%d command='%s'\n",
 279                       iir, current->pid, current->comm);
 280                show_regs(regs);
 281#endif
 282                si.si_signo = SIGTRAP;
 283                si.si_code = TRAP_BRKPT;
 284                si.si_addr = (void *) (regs->iaoq[0] & ~3);
 285                force_sig_info(SIGTRAP, &si, current);
 286                return;
 287        }
 288}
 289
 290
 291int handle_toc(void)
 292{
 293        printk(KERN_CRIT "TOC call.\n");
 294        return 0;
 295}
 296
 297static void default_trap(int code, struct pt_regs *regs)
 298{
 299        printk(KERN_ERR "Trap %d on CPU %d\n", code, smp_processor_id());
 300        show_regs(regs);
 301}
 302
 303void (*cpu_lpmc) (int code, struct pt_regs *regs) = default_trap;
 304
 305
 306void transfer_pim_to_trap_frame(struct pt_regs *regs)
 307{
 308    register int i;
 309    extern unsigned int hpmc_pim_data[];
 310    struct pdc_hpmc_pim_11 *pim_narrow;
 311    struct pdc_hpmc_pim_20 *pim_wide;
 312
 313    if (boot_cpu_data.cpu_type >= pcxu) {
 314
 315        pim_wide = (struct pdc_hpmc_pim_20 *)hpmc_pim_data;
 316
 317        /*
 318         * Note: The following code will probably generate a
 319         * bunch of truncation error warnings from the compiler.
 320         * Could be handled with an ifdef, but perhaps there
 321         * is a better way.
 322         */
 323
 324        regs->gr[0] = pim_wide->cr[22];
 325
 326        for (i = 1; i < 32; i++)
 327            regs->gr[i] = pim_wide->gr[i];
 328
 329        for (i = 0; i < 32; i++)
 330            regs->fr[i] = pim_wide->fr[i];
 331
 332        for (i = 0; i < 8; i++)
 333            regs->sr[i] = pim_wide->sr[i];
 334
 335        regs->iasq[0] = pim_wide->cr[17];
 336        regs->iasq[1] = pim_wide->iasq_back;
 337        regs->iaoq[0] = pim_wide->cr[18];
 338        regs->iaoq[1] = pim_wide->iaoq_back;
 339
 340        regs->sar  = pim_wide->cr[11];
 341        regs->iir  = pim_wide->cr[19];
 342        regs->isr  = pim_wide->cr[20];
 343        regs->ior  = pim_wide->cr[21];
 344    }
 345    else {
 346        pim_narrow = (struct pdc_hpmc_pim_11 *)hpmc_pim_data;
 347
 348        regs->gr[0] = pim_narrow->cr[22];
 349
 350        for (i = 1; i < 32; i++)
 351            regs->gr[i] = pim_narrow->gr[i];
 352
 353        for (i = 0; i < 32; i++)
 354            regs->fr[i] = pim_narrow->fr[i];
 355
 356        for (i = 0; i < 8; i++)
 357            regs->sr[i] = pim_narrow->sr[i];
 358
 359        regs->iasq[0] = pim_narrow->cr[17];
 360        regs->iasq[1] = pim_narrow->iasq_back;
 361        regs->iaoq[0] = pim_narrow->cr[18];
 362        regs->iaoq[1] = pim_narrow->iaoq_back;
 363
 364        regs->sar  = pim_narrow->cr[11];
 365        regs->iir  = pim_narrow->cr[19];
 366        regs->isr  = pim_narrow->cr[20];
 367        regs->ior  = pim_narrow->cr[21];
 368    }
 369
 370    /*
 371     * The following fields only have meaning if we came through
 372     * another path. So just zero them here.
 373     */
 374
 375    regs->ksp = 0;
 376    regs->kpc = 0;
 377    regs->orig_r28 = 0;
 378}
 379
 380
 381/*
 382 * This routine is called as a last resort when everything else
 383 * has gone clearly wrong. We get called for faults in kernel space,
 384 * and HPMC's.
 385 */
 386void parisc_terminate(char *msg, struct pt_regs *regs, int code, unsigned long offset)
 387{
 388        static DEFINE_SPINLOCK(terminate_lock);
 389
 390        oops_in_progress = 1;
 391
 392        set_eiem(0);
 393        local_irq_disable();
 394        spin_lock(&terminate_lock);
 395
 396        /* unlock the pdc lock if necessary */
 397        pdc_emergency_unlock();
 398
 399        /* restart pdc console if necessary */
 400        if (!console_drivers)
 401                pdc_console_restart();
 402
 403        /* Not all paths will gutter the processor... */
 404        switch(code){
 405
 406        case 1:
 407                transfer_pim_to_trap_frame(regs);
 408                break;
 409
 410        default:
 411                /* Fall through */
 412                break;
 413
 414        }
 415            
 416        {
 417                /* show_stack(NULL, (unsigned long *)regs->gr[30]); */
 418                struct unwind_frame_info info;
 419                unwind_frame_init(&info, current, regs->gr[30], regs->iaoq[0], regs->gr[2]);
 420                do_show_stack(&info);
 421        }
 422
 423        printk("\n");
 424        printk(KERN_CRIT "%s: Code=%d regs=%p (Addr=" RFMT ")\n",
 425                        msg, code, regs, offset);
 426        show_regs(regs);
 427
 428        spin_unlock(&terminate_lock);
 429
 430        /* put soft power button back under hardware control;
 431         * if the user had pressed it once at any time, the 
 432         * system will shut down immediately right here. */
 433        pdc_soft_power_button(0);
 434        
 435        /* Call kernel panic() so reboot timeouts work properly 
 436         * FIXME: This function should be on the list of
 437         * panic notifiers, and we should call panic
 438         * directly from the location that we wish. 
 439         * e.g. We should not call panic from
 440         * parisc_terminate, but rather the oter way around.
 441         * This hack works, prints the panic message twice,
 442         * and it enables reboot timers!
 443         */
 444        panic(msg);
 445}
 446
 447void handle_interruption(int code, struct pt_regs *regs)
 448{
 449        unsigned long fault_address = 0;
 450        unsigned long fault_space = 0;
 451        struct siginfo si;
 452
 453        if (code == 1)
 454            pdc_console_restart();  /* switch back to pdc if HPMC */
 455        else
 456            local_irq_enable();
 457
 458        /* Security check:
 459         * If the priority level is still user, and the
 460         * faulting space is not equal to the active space
 461         * then the user is attempting something in a space
 462         * that does not belong to them. Kill the process.
 463         *
 464         * This is normally the situation when the user
 465         * attempts to jump into the kernel space at the
 466         * wrong offset, be it at the gateway page or a
 467         * random location.
 468         *
 469         * We cannot normally signal the process because it
 470         * could *be* on the gateway page, and processes
 471         * executing on the gateway page can't have signals
 472         * delivered.
 473         * 
 474         * We merely readjust the address into the users
 475         * space, at a destination address of zero, and
 476         * allow processing to continue.
 477         */
 478        if (((unsigned long)regs->iaoq[0] & 3) &&
 479            ((unsigned long)regs->iasq[0] != (unsigned long)regs->sr[7])) { 
 480                /* Kill the user process later */
 481                regs->iaoq[0] = 0 | 3;
 482                regs->iaoq[1] = regs->iaoq[0] + 4;
 483                regs->iasq[0] = regs->iasq[0] = regs->sr[7];
 484                regs->gr[0] &= ~PSW_B;
 485                return;
 486        }
 487        
 488#if 0
 489        printk(KERN_CRIT "Interruption # %d\n", code);
 490#endif
 491
 492        switch(code) {
 493
 494        case  1:
 495                /* High-priority machine check (HPMC) */
 496                
 497                /* set up a new led state on systems shipped with a LED State panel */
 498                pdc_chassis_send_status(PDC_CHASSIS_DIRECT_HPMC);
 499                    
 500                parisc_terminate("High Priority Machine Check (HPMC)",
 501                                regs, code, 0);
 502                /* NOT REACHED */
 503                
 504        case  2:
 505                /* Power failure interrupt */
 506                printk(KERN_CRIT "Power failure interrupt !\n");
 507                return;
 508
 509        case  3:
 510                /* Recovery counter trap */
 511                regs->gr[0] &= ~PSW_R;
 512                if (user_space(regs))
 513                        handle_gdb_break(regs, TRAP_TRACE);
 514                /* else this must be the start of a syscall - just let it run */
 515                return;
 516
 517        case  5:
 518                /* Low-priority machine check */
 519                pdc_chassis_send_status(PDC_CHASSIS_DIRECT_LPMC);
 520                
 521                flush_all_caches();
 522                cpu_lpmc(5, regs);
 523                return;
 524
 525        case  6:
 526                /* Instruction TLB miss fault/Instruction page fault */
 527                fault_address = regs->iaoq[0];
 528                fault_space   = regs->iasq[0];
 529                break;
 530
 531        case  8:
 532                /* Illegal instruction trap */
 533                die_if_kernel("Illegal instruction", regs, code);
 534                si.si_code = ILL_ILLOPC;
 535                goto give_sigill;
 536
 537        case  9:
 538                /* Break instruction trap */
 539                handle_break(regs->iir,regs);
 540                return;
 541        
 542        case 10:
 543                /* Privileged operation trap */
 544                die_if_kernel("Privileged operation", regs, code);
 545                si.si_code = ILL_PRVOPC;
 546                goto give_sigill;
 547        
 548        case 11:
 549                /* Privileged register trap */
 550                if ((regs->iir & 0xffdfffe0) == 0x034008a0) {
 551
 552                        /* This is a MFCTL cr26/cr27 to gr instruction.
 553                         * PCXS traps on this, so we need to emulate it.
 554                         */
 555
 556                        if (regs->iir & 0x00200000)
 557                                regs->gr[regs->iir & 0x1f] = mfctl(27);
 558                        else
 559                                regs->gr[regs->iir & 0x1f] = mfctl(26);
 560
 561                        regs->iaoq[0] = regs->iaoq[1];
 562                        regs->iaoq[1] += 4;
 563                        regs->iasq[0] = regs->iasq[1];
 564                        return;
 565                }
 566
 567                die_if_kernel("Privileged register usage", regs, code);
 568                si.si_code = ILL_PRVREG;
 569        give_sigill:
 570                si.si_signo = SIGILL;
 571                si.si_errno = 0;
 572                si.si_addr = (void *) regs->iaoq[0];
 573                force_sig_info(SIGILL, &si, current);
 574                return;
 575
 576        case 12:
 577                /* Overflow Trap, let the userland signal handler do the cleanup */
 578                si.si_signo = SIGFPE;
 579                si.si_code = FPE_INTOVF;
 580                si.si_addr = (void *) regs->iaoq[0];
 581                force_sig_info(SIGFPE, &si, current);
 582                return;
 583                
 584        case 13:
 585                /* Conditional Trap
 586                   The condition succees in an instruction which traps 
 587                   on condition  */
 588                if(user_mode(regs)){
 589                        si.si_signo = SIGFPE;
 590                        /* Set to zero, and let the userspace app figure it out from
 591                           the insn pointed to by si_addr */
 592                        si.si_code = 0;
 593                        si.si_addr = (void __user *) regs->iaoq[0];
 594                        force_sig_info(SIGFPE, &si, current);
 595                        return;
 596                } 
 597                /* The kernel doesn't want to handle condition codes */
 598                break;
 599                
 600        case 14:
 601                /* Assist Exception Trap, i.e. floating point exception. */
 602                die_if_kernel("Floating point exception", regs, 0); /* quiet */
 603                handle_fpe(regs);
 604                return;
 605                
 606        case 15:
 607                /* Data TLB miss fault/Data page fault */
 608                /* Fall through */
 609        case 16:
 610                /* Non-access instruction TLB miss fault */
 611                /* The instruction TLB entry needed for the target address of the FIC
 612                   is absent, and hardware can't find it, so we get to cleanup */
 613                /* Fall through */
 614        case 17:
 615                /* Non-access data TLB miss fault/Non-access data page fault */
 616                /* FIXME: 
 617                         Still need to add slow path emulation code here!
 618                         If the insn used a non-shadow register, then the tlb
 619                         handlers could not have their side-effect (e.g. probe
 620                         writing to a target register) emulated since rfir would
 621                         erase the changes to said register. Instead we have to
 622                         setup everything, call this function we are in, and emulate
 623                         by hand. Technically we need to emulate:
 624                         fdc,fdce,pdc,"fic,4f",prober,probeir,probew, probeiw
 625                */                        
 626                fault_address = regs->ior;
 627                fault_space = regs->isr;
 628                break;
 629
 630        case 18:
 631                /* PCXS only -- later cpu's split this into types 26,27 & 28 */
 632                /* Check for unaligned access */
 633                if (check_unaligned(regs)) {
 634                        handle_unaligned(regs);
 635                        return;
 636                }
 637                /* Fall Through */
 638        case 26: 
 639                /* PCXL: Data memory access rights trap */
 640                fault_address = regs->ior;
 641                fault_space   = regs->isr;
 642                break;
 643
 644        case 19:
 645                /* Data memory break trap */
 646                regs->gr[0] |= PSW_X; /* So we can single-step over the trap */
 647                /* fall thru */
 648        case 21:
 649                /* Page reference trap */
 650                handle_gdb_break(regs, TRAP_HWBKPT);
 651                return;
 652
 653        case 25:
 654                /* Taken branch trap */
 655                regs->gr[0] &= ~PSW_T;
 656                if (user_space(regs))
 657                        handle_gdb_break(regs, TRAP_BRANCH);
 658                /* else this must be the start of a syscall - just let it
 659                 * run.
 660                 */
 661                return;
 662
 663        case  7:  
 664                /* Instruction access rights */
 665                /* PCXL: Instruction memory protection trap */
 666
 667                /*
 668                 * This could be caused by either: 1) a process attempting
 669                 * to execute within a vma that does not have execute
 670                 * permission, or 2) an access rights violation caused by a
 671                 * flush only translation set up by ptep_get_and_clear().
 672                 * So we check the vma permissions to differentiate the two.
 673                 * If the vma indicates we have execute permission, then
 674                 * the cause is the latter one. In this case, we need to
 675                 * call do_page_fault() to fix the problem.
 676                 */
 677
 678                if (user_mode(regs)) {
 679                        struct vm_area_struct *vma;
 680
 681                        down_read(&current->mm->mmap_sem);
 682                        vma = find_vma(current->mm,regs->iaoq[0]);
 683                        if (vma && (regs->iaoq[0] >= vma->vm_start)
 684                                && (vma->vm_flags & VM_EXEC)) {
 685
 686                                fault_address = regs->iaoq[0];
 687                                fault_space = regs->iasq[0];
 688
 689                                up_read(&current->mm->mmap_sem);
 690                                break; /* call do_page_fault() */
 691                        }
 692                        up_read(&current->mm->mmap_sem);
 693                }
 694                /* Fall Through */
 695        case 27: 
 696                /* Data memory protection ID trap */
 697                die_if_kernel("Protection id trap", regs, code);
 698                si.si_code = SEGV_MAPERR;
 699                si.si_signo = SIGSEGV;
 700                si.si_errno = 0;
 701                if (code == 7)
 702                    si.si_addr = (void *) regs->iaoq[0];
 703                else
 704                    si.si_addr = (void *) regs->ior;
 705                force_sig_info(SIGSEGV, &si, current);
 706                return;
 707
 708        case 28: 
 709                /* Unaligned data reference trap */
 710                handle_unaligned(regs);
 711                return;
 712
 713        default:
 714                if (user_mode(regs)) {
 715#ifdef PRINT_USER_FAULTS
 716                        printk(KERN_DEBUG "\nhandle_interruption() pid=%d command='%s'\n",
 717                            current->pid, current->comm);
 718                        show_regs(regs);
 719#endif
 720                        /* SIGBUS, for lack of a better one. */
 721                        si.si_signo = SIGBUS;
 722                        si.si_code = BUS_OBJERR;
 723                        si.si_errno = 0;
 724                        si.si_addr = (void *) regs->ior;
 725                        force_sig_info(SIGBUS, &si, current);
 726                        return;
 727                }
 728                pdc_chassis_send_status(PDC_CHASSIS_DIRECT_PANIC);
 729                
 730                parisc_terminate("Unexpected interruption", regs, code, 0);
 731                /* NOT REACHED */
 732        }
 733
 734        if (user_mode(regs)) {
 735            if ((fault_space>>SPACEID_SHIFT) != (regs->sr[7] >> SPACEID_SHIFT)) {
 736#ifdef PRINT_USER_FAULTS
 737                if (fault_space == 0)
 738                        printk(KERN_DEBUG "User Fault on Kernel Space ");
 739                else
 740                        printk(KERN_DEBUG "User Fault (long pointer) (fault %d) ",
 741                               code);
 742                printk("pid=%d command='%s'\n", current->pid, current->comm);
 743                show_regs(regs);
 744#endif
 745                si.si_signo = SIGSEGV;
 746                si.si_errno = 0;
 747                si.si_code = SEGV_MAPERR;
 748                si.si_addr = (void *) regs->ior;
 749                force_sig_info(SIGSEGV, &si, current);
 750                return;
 751            }
 752        }
 753        else {
 754
 755            /*
 756             * The kernel should never fault on its own address space.
 757             */
 758
 759            if (fault_space == 0) 
 760            {
 761                pdc_chassis_send_status(PDC_CHASSIS_DIRECT_PANIC);
 762                parisc_terminate("Kernel Fault", regs, code, fault_address);
 763        
 764            }
 765        }
 766
 767        do_page_fault(regs, code, fault_address);
 768}
 769
 770
 771int __init check_ivt(void *iva)
 772{
 773        int i;
 774        u32 check = 0;
 775        u32 *ivap;
 776        u32 *hpmcp;
 777        u32 length;
 778        extern void os_hpmc(void);
 779        extern void os_hpmc_end(void);
 780
 781        if (strcmp((char *)iva, "cows can fly"))
 782                return -1;
 783
 784        ivap = (u32 *)iva;
 785
 786        for (i = 0; i < 8; i++)
 787            *ivap++ = 0;
 788
 789        /* Compute Checksum for HPMC handler */
 790
 791        length = (u32)((unsigned long)os_hpmc_end - (unsigned long)os_hpmc);
 792        ivap[7] = length;
 793
 794        hpmcp = (u32 *)os_hpmc;
 795
 796        for (i=0; i<length/4; i++)
 797            check += *hpmcp++;
 798
 799        for (i=0; i<8; i++)
 800            check += ivap[i];
 801
 802        ivap[5] = -check;
 803
 804        return 0;
 805}
 806        
 807#ifndef __LP64__
 808extern const void fault_vector_11;
 809#endif
 810extern const void fault_vector_20;
 811
 812void __init trap_init(void)
 813{
 814        void *iva;
 815
 816        if (boot_cpu_data.cpu_type >= pcxu)
 817                iva = (void *) &fault_vector_20;
 818        else
 819#ifdef __LP64__
 820                panic("Can't boot 64-bit OS on PA1.1 processor!");
 821#else
 822                iva = (void *) &fault_vector_11;
 823#endif
 824
 825        if (check_ivt(iva))
 826                panic("IVT invalid");
 827}
 828
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