linux-bk/arch/sparc/kernel/traps.c
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   1/* $Id: traps.c,v 1.64 2000/09/03 15:00:49 anton Exp $
   2 * arch/sparc/kernel/traps.c
   3 *
   4 * Copyright 1995 David S. Miller (davem@caip.rutgers.edu)
   5 * Copyright 2000 Jakub Jelinek (jakub@redhat.com)
   6 */
   7
   8/*
   9 * I hate traps on the sparc, grrr...
  10 */
  11
  12#include <linux/config.h>
  13#include <linux/sched.h>  /* for jiffies */
  14#include <linux/kernel.h>
  15#include <linux/kallsyms.h>
  16#include <linux/signal.h>
  17#include <linux/smp.h>
  18#include <linux/smp_lock.h>
  19
  20#include <asm/delay.h>
  21#include <asm/system.h>
  22#include <asm/ptrace.h>
  23#include <asm/oplib.h>
  24#include <asm/page.h>
  25#include <asm/pgtable.h>
  26#include <asm/kdebug.h>
  27#include <asm/unistd.h>
  28#include <asm/traps.h>
  29
  30/* #define TRAP_DEBUG */
  31
  32struct trap_trace_entry {
  33        unsigned long pc;
  34        unsigned long type;
  35};
  36
  37int trap_curbuf = 0;
  38struct trap_trace_entry trapbuf[1024];
  39
  40void syscall_trace_entry(struct pt_regs *regs)
  41{
  42        printk("%s[%d]: ", current->comm, current->pid);
  43        printk("scall<%d> (could be %d)\n", (int) regs->u_regs[UREG_G1],
  44               (int) regs->u_regs[UREG_I0]);
  45}
  46
  47void syscall_trace_exit(struct pt_regs *regs)
  48{
  49}
  50
  51void sun4m_nmi(struct pt_regs *regs)
  52{
  53        unsigned long afsr, afar;
  54
  55        printk("Aieee: sun4m NMI received!\n");
  56        /* XXX HyperSparc hack XXX */
  57        __asm__ __volatile__("mov 0x500, %%g1\n\t"
  58                             "lda [%%g1] 0x4, %0\n\t"
  59                             "mov 0x600, %%g1\n\t"
  60                             "lda [%%g1] 0x4, %1\n\t" :
  61                             "=r" (afsr), "=r" (afar));
  62        printk("afsr=%08lx afar=%08lx\n", afsr, afar);
  63        printk("you lose buddy boy...\n");
  64        show_regs(regs);
  65        prom_halt();
  66}
  67
  68void sun4d_nmi(struct pt_regs *regs)
  69{
  70        printk("Aieee: sun4d NMI received!\n");
  71        printk("you lose buddy boy...\n");
  72        show_regs(regs);
  73        prom_halt();
  74}
  75
  76void instruction_dump (unsigned long *pc)
  77{
  78        int i;
  79        
  80        if((((unsigned long) pc) & 3))
  81                return;
  82
  83        for(i = -3; i < 6; i++)
  84                printk("%c%08lx%c",i?' ':'<',pc[i],i?' ':'>');
  85        printk("\n");
  86}
  87
  88#define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
  89#define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
  90
  91void die_if_kernel(char *str, struct pt_regs *regs)
  92{
  93        static int die_counter;
  94        int count = 0;
  95
  96        /* Amuse the user. */
  97        printk(
  98"              \\|/ ____ \\|/\n"
  99"              \"@'/ ,. \\`@\"\n"
 100"              /_| \\__/ |_\\\n"
 101"                 \\__U_/\n");
 102
 103        printk("%s(%d): %s [#%d]\n", current->comm, current->pid, str, ++die_counter);
 104        show_regs(regs);
 105
 106        __SAVE; __SAVE; __SAVE; __SAVE;
 107        __SAVE; __SAVE; __SAVE; __SAVE;
 108        __RESTORE; __RESTORE; __RESTORE; __RESTORE;
 109        __RESTORE; __RESTORE; __RESTORE; __RESTORE;
 110
 111        {
 112                struct reg_window *rw = (struct reg_window *)regs->u_regs[UREG_FP];
 113
 114                /* Stop the back trace when we hit userland or we
 115                 * find some badly aligned kernel stack. Set an upper
 116                 * bound in case our stack is trashed and we loop.
 117                 */
 118                while(rw                                        &&
 119                      count++ < 30                              &&
 120                      (((unsigned long) rw) >= PAGE_OFFSET)     &&
 121                      !(((unsigned long) rw) & 0x7)) {
 122                        printk("Caller[%08lx]", rw->ins[7]);
 123                        print_symbol(": %s\n", rw->ins[7]);
 124                        rw = (struct reg_window *)rw->ins[6];
 125                }
 126        }
 127        printk("Instruction DUMP:");
 128        instruction_dump ((unsigned long *) regs->pc);
 129        if(regs->psr & PSR_PS)
 130                do_exit(SIGKILL);
 131        do_exit(SIGSEGV);
 132}
 133
 134void do_hw_interrupt(struct pt_regs *regs, unsigned long type)
 135{
 136        siginfo_t info;
 137
 138        if(type < 0x80) {
 139                /* Sun OS's puke from bad traps, Linux survives! */
 140                printk("Unimplemented Sparc TRAP, type = %02lx\n", type);
 141                die_if_kernel("Whee... Hello Mr. Penguin", regs);
 142        }       
 143
 144        if(regs->psr & PSR_PS)
 145                die_if_kernel("Kernel bad trap", regs);
 146
 147        info.si_signo = SIGILL;
 148        info.si_errno = 0;
 149        info.si_code = ILL_ILLTRP;
 150        info.si_addr = (void __user *)regs->pc;
 151        info.si_trapno = type - 0x80;
 152        force_sig_info(SIGILL, &info, current);
 153}
 154
 155void do_illegal_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 156                            unsigned long psr)
 157{
 158        extern int do_user_muldiv (struct pt_regs *, unsigned long);
 159        siginfo_t info;
 160
 161        if(psr & PSR_PS)
 162                die_if_kernel("Kernel illegal instruction", regs);
 163#ifdef TRAP_DEBUG
 164        printk("Ill instr. at pc=%08lx instruction is %08lx\n",
 165               regs->pc, *(unsigned long *)regs->pc);
 166#endif
 167        if (!do_user_muldiv (regs, pc))
 168                return;
 169
 170        info.si_signo = SIGILL;
 171        info.si_errno = 0;
 172        info.si_code = ILL_ILLOPC;
 173        info.si_addr = (void __user *)pc;
 174        info.si_trapno = 0;
 175        send_sig_info(SIGILL, &info, current);
 176}
 177
 178void do_priv_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 179                         unsigned long psr)
 180{
 181        siginfo_t info;
 182
 183        if(psr & PSR_PS)
 184                die_if_kernel("Penguin instruction from Penguin mode??!?!", regs);
 185        info.si_signo = SIGILL;
 186        info.si_errno = 0;
 187        info.si_code = ILL_PRVOPC;
 188        info.si_addr = (void __user *)pc;
 189        info.si_trapno = 0;
 190        send_sig_info(SIGILL, &info, current);
 191}
 192
 193/* XXX User may want to be allowed to do this. XXX */
 194
 195void do_memaccess_unaligned(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 196                            unsigned long psr)
 197{
 198        siginfo_t info;
 199
 200        if(regs->psr & PSR_PS) {
 201                printk("KERNEL MNA at pc %08lx npc %08lx called by %08lx\n", pc, npc,
 202                       regs->u_regs[UREG_RETPC]);
 203                die_if_kernel("BOGUS", regs);
 204                /* die_if_kernel("Kernel MNA access", regs); */
 205        }
 206#if 0
 207        show_regs (regs);
 208        instruction_dump ((unsigned long *) regs->pc);
 209        printk ("do_MNA!\n");
 210#endif
 211        info.si_signo = SIGBUS;
 212        info.si_errno = 0;
 213        info.si_code = BUS_ADRALN;
 214        info.si_addr = /* FIXME: Should dig out mna address */ (void *)0;
 215        info.si_trapno = 0;
 216        send_sig_info(SIGBUS, &info, current);
 217}
 218
 219extern void fpsave(unsigned long *fpregs, unsigned long *fsr,
 220                   void *fpqueue, unsigned long *fpqdepth);
 221extern void fpload(unsigned long *fpregs, unsigned long *fsr);
 222
 223static unsigned long init_fsr = 0x0UL;
 224static unsigned long init_fregs[32] __attribute__ ((aligned (8))) =
 225                { ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
 226                  ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
 227                  ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
 228                  ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL };
 229
 230void do_fpd_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 231                 unsigned long psr)
 232{
 233        /* Sanity check... */
 234        if(psr & PSR_PS)
 235                die_if_kernel("Kernel gets FloatingPenguinUnit disabled trap", regs);
 236
 237        put_psr(get_psr() | PSR_EF);    /* Allow FPU ops. */
 238        regs->psr |= PSR_EF;
 239#ifndef CONFIG_SMP
 240        if(last_task_used_math == current)
 241                return;
 242        if(last_task_used_math) {
 243                /* Other processes fpu state, save away */
 244                struct task_struct *fptask = last_task_used_math;
 245                fpsave(&fptask->thread.float_regs[0], &fptask->thread.fsr,
 246                       &fptask->thread.fpqueue[0], &fptask->thread.fpqdepth);
 247        }
 248        last_task_used_math = current;
 249        if(used_math()) {
 250                fpload(&current->thread.float_regs[0], &current->thread.fsr);
 251        } else {
 252                /* Set initial sane state. */
 253                fpload(&init_fregs[0], &init_fsr);
 254                set_used_math();
 255        }
 256#else
 257        if(!used_math()) {
 258                fpload(&init_fregs[0], &init_fsr);
 259                set_used_math();
 260        } else {
 261                fpload(&current->thread.float_regs[0], &current->thread.fsr);
 262        }
 263        current_thread_info()->flags |= _TIF_USEDFPU;
 264#endif
 265}
 266
 267static unsigned long fake_regs[32] __attribute__ ((aligned (8)));
 268static unsigned long fake_fsr;
 269static unsigned long fake_queue[32] __attribute__ ((aligned (8)));
 270static unsigned long fake_depth;
 271
 272extern int do_mathemu(struct pt_regs *, struct task_struct *);
 273
 274void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 275                 unsigned long psr)
 276{
 277        static int calls;
 278        siginfo_t info;
 279        unsigned long fsr;
 280        int ret = 0;
 281#ifndef CONFIG_SMP
 282        struct task_struct *fpt = last_task_used_math;
 283#else
 284        struct task_struct *fpt = current;
 285#endif
 286        put_psr(get_psr() | PSR_EF);
 287        /* If nobody owns the fpu right now, just clear the
 288         * error into our fake static buffer and hope it don't
 289         * happen again.  Thank you crashme...
 290         */
 291#ifndef CONFIG_SMP
 292        if(!fpt) {
 293#else
 294        if(!(fpt->thread_info->flags & _TIF_USEDFPU)) {
 295#endif
 296                fpsave(&fake_regs[0], &fake_fsr, &fake_queue[0], &fake_depth);
 297                regs->psr &= ~PSR_EF;
 298                return;
 299        }
 300        fpsave(&fpt->thread.float_regs[0], &fpt->thread.fsr,
 301               &fpt->thread.fpqueue[0], &fpt->thread.fpqdepth);
 302#ifdef DEBUG_FPU
 303        printk("Hmm, FP exception, fsr was %016lx\n", fpt->thread.fsr);
 304#endif
 305
 306        switch ((fpt->thread.fsr & 0x1c000)) {
 307        /* switch on the contents of the ftt [floating point trap type] field */
 308#ifdef DEBUG_FPU
 309        case (1 << 14):
 310                printk("IEEE_754_exception\n");
 311                break;
 312#endif
 313        case (2 << 14):  /* unfinished_FPop (underflow & co) */
 314        case (3 << 14):  /* unimplemented_FPop (quad stuff, maybe sqrt) */
 315                ret = do_mathemu(regs, fpt);
 316                break;
 317#ifdef DEBUG_FPU
 318        case (4 << 14):
 319                printk("sequence_error (OS bug...)\n");
 320                break;
 321        case (5 << 14):
 322                printk("hardware_error (uhoh!)\n");
 323                break;
 324        case (6 << 14):
 325                printk("invalid_fp_register (user error)\n");
 326                break;
 327#endif /* DEBUG_FPU */
 328        }
 329        /* If we successfully emulated the FPop, we pretend the trap never happened :-> */
 330        if (ret) {
 331                fpload(&current->thread.float_regs[0], &current->thread.fsr);
 332                return;
 333        }
 334        /* nope, better SIGFPE the offending process... */
 335               
 336#ifdef CONFIG_SMP
 337        fpt->thread_info->flags &= ~_TIF_USEDFPU;
 338#endif
 339        if(psr & PSR_PS) {
 340                /* The first fsr store/load we tried trapped,
 341                 * the second one will not (we hope).
 342                 */
 343                printk("WARNING: FPU exception from kernel mode. at pc=%08lx\n",
 344                       regs->pc);
 345                regs->pc = regs->npc;
 346                regs->npc += 4;
 347                calls++;
 348                if(calls > 2)
 349                        die_if_kernel("Too many Penguin-FPU traps from kernel mode",
 350                                      regs);
 351                return;
 352        }
 353
 354        fsr = fpt->thread.fsr;
 355        info.si_signo = SIGFPE;
 356        info.si_errno = 0;
 357        info.si_addr = (void __user *)pc;
 358        info.si_trapno = 0;
 359        info.si_code = __SI_FAULT;
 360        if ((fsr & 0x1c000) == (1 << 14)) {
 361                if (fsr & 0x10)
 362                        info.si_code = FPE_FLTINV;
 363                else if (fsr & 0x08)
 364                        info.si_code = FPE_FLTOVF;
 365                else if (fsr & 0x04)
 366                        info.si_code = FPE_FLTUND;
 367                else if (fsr & 0x02)
 368                        info.si_code = FPE_FLTDIV;
 369                else if (fsr & 0x01)
 370                        info.si_code = FPE_FLTRES;
 371        }
 372        send_sig_info(SIGFPE, &info, fpt);
 373#ifndef CONFIG_SMP
 374        last_task_used_math = NULL;
 375#endif
 376        regs->psr &= ~PSR_EF;
 377        if(calls > 0)
 378                calls=0;
 379}
 380
 381void handle_tag_overflow(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 382                         unsigned long psr)
 383{
 384        siginfo_t info;
 385
 386        if(psr & PSR_PS)
 387                die_if_kernel("Penguin overflow trap from kernel mode", regs);
 388        info.si_signo = SIGEMT;
 389        info.si_errno = 0;
 390        info.si_code = EMT_TAGOVF;
 391        info.si_addr = (void __user *)pc;
 392        info.si_trapno = 0;
 393        send_sig_info(SIGEMT, &info, current);
 394}
 395
 396void handle_watchpoint(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 397                       unsigned long psr)
 398{
 399#ifdef TRAP_DEBUG
 400        printk("Watchpoint detected at PC %08lx NPC %08lx PSR %08lx\n",
 401               pc, npc, psr);
 402#endif
 403        if(psr & PSR_PS)
 404                panic("Tell me what a watchpoint trap is, and I'll then deal "
 405                      "with such a beast...");
 406}
 407
 408void handle_reg_access(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 409                       unsigned long psr)
 410{
 411        siginfo_t info;
 412
 413#ifdef TRAP_DEBUG
 414        printk("Register Access Exception at PC %08lx NPC %08lx PSR %08lx\n",
 415               pc, npc, psr);
 416#endif
 417        info.si_signo = SIGBUS;
 418        info.si_errno = 0;
 419        info.si_code = BUS_OBJERR;
 420        info.si_addr = (void __user *)pc;
 421        info.si_trapno = 0;
 422        force_sig_info(SIGBUS, &info, current);
 423}
 424
 425void handle_cp_disabled(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 426                        unsigned long psr)
 427{
 428        siginfo_t info;
 429
 430        info.si_signo = SIGILL;
 431        info.si_errno = 0;
 432        info.si_code = ILL_COPROC;
 433        info.si_addr = (void __user *)pc;
 434        info.si_trapno = 0;
 435        send_sig_info(SIGILL, &info, current);
 436}
 437
 438void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 439                         unsigned long psr)
 440{
 441        siginfo_t info;
 442
 443#ifdef TRAP_DEBUG
 444        printk("Co-Processor Exception at PC %08lx NPC %08lx PSR %08lx\n",
 445               pc, npc, psr);
 446#endif
 447        info.si_signo = SIGILL;
 448        info.si_errno = 0;
 449        info.si_code = ILL_COPROC;
 450        info.si_addr = (void __user *)pc;
 451        info.si_trapno = 0;
 452        send_sig_info(SIGILL, &info, current);
 453}
 454
 455void handle_hw_divzero(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 456                       unsigned long psr)
 457{
 458        siginfo_t info;
 459
 460        info.si_signo = SIGFPE;
 461        info.si_errno = 0;
 462        info.si_code = FPE_INTDIV;
 463        info.si_addr = (void __user *)pc;
 464        info.si_trapno = 0;
 465        send_sig_info(SIGFPE, &info, current);
 466}
 467
 468#ifdef CONFIG_DEBUG_BUGVERBOSE
 469void do_BUG(const char *file, int line)
 470{
 471        // bust_spinlocks(1);   XXX Not in our original BUG()
 472        printk("kernel BUG at %s:%d!\n", file, line);
 473}
 474#endif
 475
 476/* Since we have our mappings set up, on multiprocessors we can spin them
 477 * up here so that timer interrupts work during initialization.
 478 */
 479
 480extern void sparc_cpu_startup(void);
 481
 482int linux_smp_still_initting;
 483unsigned int thiscpus_tbr;
 484int thiscpus_mid;
 485
 486void trap_init(void)
 487{
 488        extern void thread_info_offsets_are_bolixed_pete(void);
 489
 490        /* Force linker to barf if mismatched */
 491        if (TI_UWINMASK    != offsetof(struct thread_info, uwinmask) ||
 492            TI_TASK        != offsetof(struct thread_info, task) ||
 493            TI_EXECDOMAIN  != offsetof(struct thread_info, exec_domain) ||
 494            TI_FLAGS       != offsetof(struct thread_info, flags) ||
 495            TI_CPU         != offsetof(struct thread_info, cpu) ||
 496            TI_PREEMPT     != offsetof(struct thread_info, preempt_count) ||
 497            TI_SOFTIRQ     != offsetof(struct thread_info, softirq_count) ||
 498            TI_HARDIRQ     != offsetof(struct thread_info, hardirq_count) ||
 499            TI_KSP         != offsetof(struct thread_info, ksp) ||
 500            TI_KPC         != offsetof(struct thread_info, kpc) ||
 501            TI_KPSR        != offsetof(struct thread_info, kpsr) ||
 502            TI_KWIM        != offsetof(struct thread_info, kwim) ||
 503            TI_REG_WINDOW  != offsetof(struct thread_info, reg_window) ||
 504            TI_RWIN_SPTRS  != offsetof(struct thread_info, rwbuf_stkptrs) ||
 505            TI_W_SAVED     != offsetof(struct thread_info, w_saved))
 506                thread_info_offsets_are_bolixed_pete();
 507
 508        /* Attach to the address space of init_task. */
 509        atomic_inc(&init_mm.mm_count);
 510        current->active_mm = &init_mm;
 511
 512        /* NOTE: Other cpus have this done as they are started
 513         *       up on SMP.
 514         */
 515}
 516
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