LXR linux/arch/sparc/kernel/traps

   1/*
   2 * arch/sparc/kernel/traps.c
   3 *
   4 * Copyright 1995, 2008 David S. Miller (davem@davemloft.net)
   5 * Copyright 2000 Jakub Jelinek (jakub@redhat.com)
   6 */
   7
   8/*
   9 * I hate traps on the sparc, grrr...
  10 */
  11
  12#include <linux/sched.h>  /* for jiffies */
  13#include <linux/kernel.h>
  14#include <linux/signal.h>
  15#include <linux/smp.h>
  16#include <linux/kdebug.h>
  17
  18#include <asm/delay.h>
  19#include <asm/system.h>
  20#include <asm/ptrace.h>
  21#include <asm/oplib.h>
  22#include <asm/page.h>
  23#include <asm/pgtable.h>
  24#include <asm/unistd.h>
  25#include <asm/traps.h>
  26
  27#include "entry.h"
  28#include "kernel.h"
  29
  30/* #define TRAP_DEBUG */
  31
  32static void instruction_dump(unsigned long *pc)
  33{
  34        int i;
  35        
  36        if((((unsigned long) pc) & 3))
  37                return;
  38
  39        for(i = -3; i < 6; i++)
  40                printk("%c%08lx%c",i?' ':'<',pc[i],i?' ':'>');
  41        printk("\n");
  42}
  43
  44#define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
  45#define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
  46
  47void die_if_kernel(char *str, struct pt_regs *regs)
  48{
  49        static int die_counter;
  50        int count = 0;
  51
  52        /* Amuse the user. */
  53        printk(
  54"              \\|/ ____ \\|/\n"
  55"              \"@'/ ,. \\`@\"\n"
  56"              /_| \\__/ |_\\\n"
  57"                 \\__U_/\n");
  58
  59        printk("%s(%d): %s [#%d]\n", current->comm, task_pid_nr(current), str, ++die_counter);
  60        show_regs(regs);
  61        add_taint(TAINT_DIE);
  62
  63        __SAVE; __SAVE; __SAVE; __SAVE;
  64        __SAVE; __SAVE; __SAVE; __SAVE;
  65        __RESTORE; __RESTORE; __RESTORE; __RESTORE;
  66        __RESTORE; __RESTORE; __RESTORE; __RESTORE;
  67
  68        {
  69                struct reg_window32 *rw = (struct reg_window32 *)regs->u_regs[UREG_FP];
  70
  71                /* Stop the back trace when we hit userland or we
  72                 * find some badly aligned kernel stack. Set an upper
  73                 * bound in case our stack is trashed and we loop.
  74                 */
  75                while(rw                                        &&
  76                      count++ < 30                              &&
  77                      (((unsigned long) rw) >= PAGE_OFFSET)     &&
  78                      !(((unsigned long) rw) & 0x7)) {
  79                        printk("Caller[%08lx]: %pS\n", rw->ins[7],
  80                               (void *) rw->ins[7]);
  81                        rw = (struct reg_window32 *)rw->ins[6];
  82                }
  83        }
  84        printk("Instruction DUMP:");
  85        instruction_dump ((unsigned long *) regs->pc);
  86        if(regs->psr & PSR_PS)
  87                do_exit(SIGKILL);
  88        do_exit(SIGSEGV);
  89}
  90
  91void do_hw_interrupt(struct pt_regs *regs, unsigned long type)
  92{
  93        siginfo_t info;
  94
  95        if(type < 0x80) {
  96                /* Sun OS's puke from bad traps, Linux survives! */
  97                printk("Unimplemented Sparc TRAP, type = %02lx\n", type);
  98                die_if_kernel("Whee... Hello Mr. Penguin", regs);
  99        }       
 100
 101        if(regs->psr & PSR_PS)
 102                die_if_kernel("Kernel bad trap", regs);
 103
 104        info.si_signo = SIGILL;
 105        info.si_errno = 0;
 106        info.si_code = ILL_ILLTRP;
 107        info.si_addr = (void __user *)regs->pc;
 108        info.si_trapno = type - 0x80;
 109        force_sig_info(SIGILL, &info, current);
 110}
 111
 112void do_illegal_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 113                            unsigned long psr)
 114{
 115        siginfo_t info;
 116
 117        if(psr & PSR_PS)
 118                die_if_kernel("Kernel illegal instruction", regs);
 119#ifdef TRAP_DEBUG
 120        printk("Ill instr. at pc=%08lx instruction is %08lx\n",
 121               regs->pc, *(unsigned long *)regs->pc);
 122#endif
 123        if (!do_user_muldiv (regs, pc))
 124                return;
 125
 126        info.si_signo = SIGILL;
 127        info.si_errno = 0;
 128        info.si_code = ILL_ILLOPC;
 129        info.si_addr = (void __user *)pc;
 130        info.si_trapno = 0;
 131        send_sig_info(SIGILL, &info, current);
 132}
 133
 134void do_priv_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 135                         unsigned long psr)
 136{
 137        siginfo_t info;
 138
 139        if(psr & PSR_PS)
 140                die_if_kernel("Penguin instruction from Penguin mode??!?!", regs);
 141        info.si_signo = SIGILL;
 142        info.si_errno = 0;
 143        info.si_code = ILL_PRVOPC;
 144        info.si_addr = (void __user *)pc;
 145        info.si_trapno = 0;
 146        send_sig_info(SIGILL, &info, current);
 147}
 148
 149/* XXX User may want to be allowed to do this. XXX */
 150
 151void do_memaccess_unaligned(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 152                            unsigned long psr)
 153{
 154        siginfo_t info;
 155
 156        if(regs->psr & PSR_PS) {
 157                printk("KERNEL MNA at pc %08lx npc %08lx called by %08lx\n", pc, npc,
 158                       regs->u_regs[UREG_RETPC]);
 159                die_if_kernel("BOGUS", regs);
 160                /* die_if_kernel("Kernel MNA access", regs); */
 161        }
 162#if 0
 163        show_regs (regs);
 164        instruction_dump ((unsigned long *) regs->pc);
 165        printk ("do_MNA!\n");
 166#endif
 167        info.si_signo = SIGBUS;
 168        info.si_errno = 0;
 169        info.si_code = BUS_ADRALN;
 170        info.si_addr = /* FIXME: Should dig out mna address */ (void *)0;
 171        info.si_trapno = 0;
 172        send_sig_info(SIGBUS, &info, current);
 173}
 174
 175static unsigned long init_fsr = 0x0UL;
 176static unsigned long init_fregs[32] __attribute__ ((aligned (8))) =
 177                { ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
 178                  ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
 179                  ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL,
 180                  ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL };
 181
 182void do_fpd_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 183                 unsigned long psr)
 184{
 185        /* Sanity check... */
 186        if(psr & PSR_PS)
 187                die_if_kernel("Kernel gets FloatingPenguinUnit disabled trap", regs);
 188
 189        put_psr(get_psr() | PSR_EF);    /* Allow FPU ops. */
 190        regs->psr |= PSR_EF;
 191#ifndef CONFIG_SMP
 192        if(last_task_used_math == current)
 193                return;
 194        if(last_task_used_math) {
 195                /* Other processes fpu state, save away */
 196                struct task_struct *fptask = last_task_used_math;
 197                fpsave(&fptask->thread.float_regs[0], &fptask->thread.fsr,
 198                       &fptask->thread.fpqueue[0], &fptask->thread.fpqdepth);
 199        }
 200        last_task_used_math = current;
 201        if(used_math()) {
 202                fpload(&current->thread.float_regs[0], &current->thread.fsr);
 203        } else {
 204                /* Set initial sane state. */
 205                fpload(&init_fregs[0], &init_fsr);
 206                set_used_math();
 207        }
 208#else
 209        if(!used_math()) {
 210                fpload(&init_fregs[0], &init_fsr);
 211                set_used_math();
 212        } else {
 213                fpload(&current->thread.float_regs[0], &current->thread.fsr);
 214        }
 215        set_thread_flag(TIF_USEDFPU);
 216#endif
 217}
 218
 219static unsigned long fake_regs[32] __attribute__ ((aligned (8)));
 220static unsigned long fake_fsr;
 221static unsigned long fake_queue[32] __attribute__ ((aligned (8)));
 222static unsigned long fake_depth;
 223
 224extern int do_mathemu(struct pt_regs *, struct task_struct *);
 225
 226void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 227                 unsigned long psr)
 228{
 229        static int calls;
 230        siginfo_t info;
 231        unsigned long fsr;
 232        int ret = 0;
 233#ifndef CONFIG_SMP
 234        struct task_struct *fpt = last_task_used_math;
 235#else
 236        struct task_struct *fpt = current;
 237#endif
 238        put_psr(get_psr() | PSR_EF);
 239        /* If nobody owns the fpu right now, just clear the
 240         * error into our fake static buffer and hope it don't
 241         * happen again.  Thank you crashme...
 242         */
 243#ifndef CONFIG_SMP
 244        if(!fpt) {
 245#else
 246        if (!test_tsk_thread_flag(fpt, TIF_USEDFPU)) {
 247#endif
 248                fpsave(&fake_regs[0], &fake_fsr, &fake_queue[0], &fake_depth);
 249                regs->psr &= ~PSR_EF;
 250                return;
 251        }
 252        fpsave(&fpt->thread.float_regs[0], &fpt->thread.fsr,
 253               &fpt->thread.fpqueue[0], &fpt->thread.fpqdepth);
 254#ifdef DEBUG_FPU
 255        printk("Hmm, FP exception, fsr was %016lx\n", fpt->thread.fsr);
 256#endif
 257
 258        switch ((fpt->thread.fsr & 0x1c000)) {
 259        /* switch on the contents of the ftt [floating point trap type] field */
 260#ifdef DEBUG_FPU
 261        case (1 << 14):
 262                printk("IEEE_754_exception\n");
 263                break;
 264#endif
 265        case (2 << 14):  /* unfinished_FPop (underflow & co) */
 266        case (3 << 14):  /* unimplemented_FPop (quad stuff, maybe sqrt) */
 267                ret = do_mathemu(regs, fpt);
 268                break;
 269#ifdef DEBUG_FPU
 270        case (4 << 14):
 271                printk("sequence_error (OS bug...)\n");
 272                break;
 273        case (5 << 14):
 274                printk("hardware_error (uhoh!)\n");
 275                break;
 276        case (6 << 14):
 277                printk("invalid_fp_register (user error)\n");
 278                break;
 279#endif /* DEBUG_FPU */
 280        }
 281        /* If we successfully emulated the FPop, we pretend the trap never happened :-> */
 282        if (ret) {
 283                fpload(&current->thread.float_regs[0], &current->thread.fsr);
 284                return;
 285        }
 286        /* nope, better SIGFPE the offending process... */
 287               
 288#ifdef CONFIG_SMP
 289        clear_tsk_thread_flag(fpt, TIF_USEDFPU);
 290#endif
 291        if(psr & PSR_PS) {
 292                /* The first fsr store/load we tried trapped,
 293                 * the second one will not (we hope).
 294                 */
 295                printk("WARNING: FPU exception from kernel mode. at pc=%08lx\n",
 296                       regs->pc);
 297                regs->pc = regs->npc;
 298                regs->npc += 4;
 299                calls++;
 300                if(calls > 2)
 301                        die_if_kernel("Too many Penguin-FPU traps from kernel mode",
 302                                      regs);
 303                return;
 304        }
 305
 306        fsr = fpt->thread.fsr;
 307        info.si_signo = SIGFPE;
 308        info.si_errno = 0;
 309        info.si_addr = (void __user *)pc;
 310        info.si_trapno = 0;
 311        info.si_code = __SI_FAULT;
 312        if ((fsr & 0x1c000) == (1 << 14)) {
 313                if (fsr & 0x10)
 314                        info.si_code = FPE_FLTINV;
 315                else if (fsr & 0x08)
 316                        info.si_code = FPE_FLTOVF;
 317                else if (fsr & 0x04)
 318                        info.si_code = FPE_FLTUND;
 319                else if (fsr & 0x02)
 320                        info.si_code = FPE_FLTDIV;
 321                else if (fsr & 0x01)
 322                        info.si_code = FPE_FLTRES;
 323        }
 324        send_sig_info(SIGFPE, &info, fpt);
 325#ifndef CONFIG_SMP
 326        last_task_used_math = NULL;
 327#endif
 328        regs->psr &= ~PSR_EF;
 329        if(calls > 0)
 330                calls=0;
 331}
 332
 333void handle_tag_overflow(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 334                         unsigned long psr)
 335{
 336        siginfo_t info;
 337
 338        if(psr & PSR_PS)
 339                die_if_kernel("Penguin overflow trap from kernel mode", regs);
 340        info.si_signo = SIGEMT;
 341        info.si_errno = 0;
 342        info.si_code = EMT_TAGOVF;
 343        info.si_addr = (void __user *)pc;
 344        info.si_trapno = 0;
 345        send_sig_info(SIGEMT, &info, current);
 346}
 347
 348void handle_watchpoint(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 349                       unsigned long psr)
 350{
 351#ifdef TRAP_DEBUG
 352        printk("Watchpoint detected at PC %08lx NPC %08lx PSR %08lx\n",
 353               pc, npc, psr);
 354#endif
 355        if(psr & PSR_PS)
 356                panic("Tell me what a watchpoint trap is, and I'll then deal "
 357                      "with such a beast...");
 358}
 359
 360void handle_reg_access(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 361                       unsigned long psr)
 362{
 363        siginfo_t info;
 364
 365#ifdef TRAP_DEBUG
 366        printk("Register Access Exception at PC %08lx NPC %08lx PSR %08lx\n",
 367               pc, npc, psr);
 368#endif
 369        info.si_signo = SIGBUS;
 370        info.si_errno = 0;
 371        info.si_code = BUS_OBJERR;
 372        info.si_addr = (void __user *)pc;
 373        info.si_trapno = 0;
 374        force_sig_info(SIGBUS, &info, current);
 375}
 376
 377void handle_cp_disabled(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 378                        unsigned long psr)
 379{
 380        siginfo_t info;
 381
 382        info.si_signo = SIGILL;
 383        info.si_errno = 0;
 384        info.si_code = ILL_COPROC;
 385        info.si_addr = (void __user *)pc;
 386        info.si_trapno = 0;
 387        send_sig_info(SIGILL, &info, current);
 388}
 389
 390void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 391                         unsigned long psr)
 392{
 393        siginfo_t info;
 394
 395#ifdef TRAP_DEBUG
 396        printk("Co-Processor Exception at PC %08lx NPC %08lx PSR %08lx\n",
 397               pc, npc, psr);
 398#endif
 399        info.si_signo = SIGILL;
 400        info.si_errno = 0;
 401        info.si_code = ILL_COPROC;
 402        info.si_addr = (void __user *)pc;
 403        info.si_trapno = 0;
 404        send_sig_info(SIGILL, &info, current);
 405}
 406
 407void handle_hw_divzero(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 408                       unsigned long psr)
 409{
 410        siginfo_t info;
 411
 412        info.si_signo = SIGFPE;
 413        info.si_errno = 0;
 414        info.si_code = FPE_INTDIV;
 415        info.si_addr = (void __user *)pc;
 416        info.si_trapno = 0;
 417        send_sig_info(SIGFPE, &info, current);
 418}
 419
 420#ifdef CONFIG_DEBUG_BUGVERBOSE
 421void do_BUG(const char *file, int line)
 422{
 423        // bust_spinlocks(1);   XXX Not in our original BUG()
 424        printk("kernel BUG at %s:%d!\n", file, line);
 425}
 426EXPORT_SYMBOL(do_BUG);
 427#endif
 428
 429/* Since we have our mappings set up, on multiprocessors we can spin them
 430 * up here so that timer interrupts work during initialization.
 431 */
 432
 433void trap_init(void)
 434{
 435        extern void thread_info_offsets_are_bolixed_pete(void);
 436
 437        /* Force linker to barf if mismatched */
 438        if (TI_UWINMASK    != offsetof(struct thread_info, uwinmask) ||
 439            TI_TASK        != offsetof(struct thread_info, task) ||
 440            TI_EXECDOMAIN  != offsetof(struct thread_info, exec_domain) ||
 441            TI_FLAGS       != offsetof(struct thread_info, flags) ||
 442            TI_CPU         != offsetof(struct thread_info, cpu) ||
 443            TI_PREEMPT     != offsetof(struct thread_info, preempt_count) ||
 444            TI_SOFTIRQ     != offsetof(struct thread_info, softirq_count) ||
 445            TI_HARDIRQ     != offsetof(struct thread_info, hardirq_count) ||
 446            TI_KSP         != offsetof(struct thread_info, ksp) ||
 447            TI_KPC         != offsetof(struct thread_info, kpc) ||
 448            TI_KPSR        != offsetof(struct thread_info, kpsr) ||
 449            TI_KWIM        != offsetof(struct thread_info, kwim) ||
 450            TI_REG_WINDOW  != offsetof(struct thread_info, reg_window) ||
 451            TI_RWIN_SPTRS  != offsetof(struct thread_info, rwbuf_stkptrs) ||
 452            TI_W_SAVED     != offsetof(struct thread_info, w_saved))
 453                thread_info_offsets_are_bolixed_pete();
 454
 455        /* Attach to the address space of init_task. */
 456        atomic_inc(&init_mm.mm_count);
 457        current->active_mm = &init_mm;
 458
 459        /* NOTE: Other cpus have this done as they are started
 460         *       up on SMP.
 461         */
 462}
 463