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#include <linux/export.h>
  18
  19#include <asm/delay.h>
  20#include <asm/system.h>
  21#include <asm/ptrace.h>
  22#include <asm/oplib.h>
  23#include <asm/page.h>
  24#include <asm/pgtable.h>
  25#include <asm/unistd.h>
  26#include <asm/traps.h>
  27
  28#include "entry.h"
  29#include "kernel.h"
  30
  31/* #define TRAP_DEBUG */
  32
  33static void instruction_dump(unsigned long *pc)
  34{
  35        int i;
  36        
  37        if((((unsigned long) pc) & 3))
  38                return;
  39
  40        for(i = -3; i < 6; i++)
  41                printk("%c%08lx%c",i?' ':'<',pc[i],i?' ':'>');
  42        printk("\n");
  43}
  44
  45#define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
  46#define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
  47
  48void die_if_kernel(char *str, struct pt_regs *regs)
  49{
  50        static int die_counter;
  51        int count = 0;
  52
  53        /* Amuse the user. */
  54        printk(
  55"              \\|/ ____ \\|/\n"
  56"              \"@'/ ,. \\`@\"\n"
  57"              /_| \\__/ |_\\\n"
  58"                 \\__U_/\n");
  59
  60        printk("%s(%d): %s [#%d]\n", current->comm, task_pid_nr(current), str, ++die_counter);
  61        show_regs(regs);
  62        add_taint(TAINT_DIE);
  63
  64        __SAVE; __SAVE; __SAVE; __SAVE;
  65        __SAVE; __SAVE; __SAVE; __SAVE;
  66        __RESTORE; __RESTORE; __RESTORE; __RESTORE;
  67        __RESTORE; __RESTORE; __RESTORE; __RESTORE;
  68
  69        {
  70                struct reg_window32 *rw = (struct reg_window32 *)regs->u_regs[UREG_FP];
  71
  72                /* Stop the back trace when we hit userland or we
  73                 * find some badly aligned kernel stack. Set an upper
  74                 * bound in case our stack is trashed and we loop.
  75                 */
  76                while(rw                                        &&
  77                      count++ < 30                              &&
  78                      (((unsigned long) rw) >= PAGE_OFFSET)     &&
  79                      !(((unsigned long) rw) & 0x7)) {
  80                        printk("Caller[%08lx]: %pS\n", rw->ins[7],
  81                               (void *) rw->ins[7]);
  82                        rw = (struct reg_window32 *)rw->ins[6];
  83                }
  84        }
  85        printk("Instruction DUMP:");
  86        instruction_dump ((unsigned long *) regs->pc);
  87        if(regs->psr & PSR_PS)
  88                do_exit(SIGKILL);
  89        do_exit(SIGSEGV);
  90}
  91
  92void do_hw_interrupt(struct pt_regs *regs, unsigned long type)
  93{
  94        siginfo_t info;
  95
  96        if(type < 0x80) {
  97                /* Sun OS's puke from bad traps, Linux survives! */
  98                printk("Unimplemented Sparc TRAP, type = %02lx\n", type);
  99                die_if_kernel("Whee... Hello Mr. Penguin", regs);
 100        }       
 101
 102        if(regs->psr & PSR_PS)
 103                die_if_kernel("Kernel bad trap", regs);
 104
 105        info.si_signo = SIGILL;
 106        info.si_errno = 0;
 107        info.si_code = ILL_ILLTRP;
 108        info.si_addr = (void __user *)regs->pc;
 109        info.si_trapno = type - 0x80;
 110        force_sig_info(SIGILL, &info, current);
 111}
 112
 113void do_illegal_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 114                            unsigned long psr)
 115{
 116        siginfo_t info;
 117
 118        if(psr & PSR_PS)
 119                die_if_kernel("Kernel illegal instruction", regs);
 120#ifdef TRAP_DEBUG
 121        printk("Ill instr. at pc=%08lx instruction is %08lx\n",
 122               regs->pc, *(unsigned long *)regs->pc);
 123#endif
 124        if (!do_user_muldiv (regs, pc))
 125                return;
 126
 127        info.si_signo = SIGILL;
 128        info.si_errno = 0;
 129        info.si_code = ILL_ILLOPC;
 130        info.si_addr = (void __user *)pc;
 131        info.si_trapno = 0;
 132        send_sig_info(SIGILL, &info, current);
 133}
 134
 135void do_priv_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 136                         unsigned long psr)
 137{
 138        siginfo_t info;
 139
 140        if(psr & PSR_PS)
 141                die_if_kernel("Penguin instruction from Penguin mode??!?!", regs);
 142        info.si_signo = SIGILL;
 143        info.si_errno = 0;
 144        info.si_code = ILL_PRVOPC;
 145        info.si_addr = (void __user *)pc;
 146        info.si_trapno = 0;
 147        send_sig_info(SIGILL, &info, current);
 148}
 149
 150/* XXX User may want to be allowed to do this. XXX */
 151
 152void do_memaccess_unaligned(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 153                            unsigned long psr)
 154{
 155        siginfo_t info;
 156
 157        if(regs->psr & PSR_PS) {
 158                printk("KERNEL MNA at pc %08lx npc %08lx called by %08lx\n", pc, npc,
 159                       regs->u_regs[UREG_RETPC]);
 160                die_if_kernel("BOGUS", regs);
 161                /* die_if_kernel("Kernel MNA access", regs); */
 162        }
 163#if 0
 164        show_regs (regs);
 165        instruction_dump ((unsigned long *) regs->pc);
 166        printk ("do_MNA!\n");
 167#endif
 168        info.si_signo = SIGBUS;
 169        info.si_errno = 0;
 170        info.si_code = BUS_ADRALN;
 171        info.si_addr = /* FIXME: Should dig out mna address */ (void *)0;
 172        info.si_trapno = 0;
 173        send_sig_info(SIGBUS, &info, current);
 174}
 175
 176static unsigned long init_fsr = 0x0UL;
 177static unsigned long init_fregs[32] __attribute__ ((aligned (8))) =
 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                  ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL, ~0UL };
 182
 183void do_fpd_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 184                 unsigned long psr)
 185{
 186        /* Sanity check... */
 187        if(psr & PSR_PS)
 188                die_if_kernel("Kernel gets FloatingPenguinUnit disabled trap", regs);
 189
 190        put_psr(get_psr() | PSR_EF);    /* Allow FPU ops. */
 191        regs->psr |= PSR_EF;
 192#ifndef CONFIG_SMP
 193        if(last_task_used_math == current)
 194                return;
 195        if(last_task_used_math) {
 196                /* Other processes fpu state, save away */
 197                struct task_struct *fptask = last_task_used_math;
 198                fpsave(&fptask->thread.float_regs[0], &fptask->thread.fsr,
 199                       &fptask->thread.fpqueue[0], &fptask->thread.fpqdepth);
 200        }
 201        last_task_used_math = current;
 202        if(used_math()) {
 203                fpload(&current->thread.float_regs[0], &current->thread.fsr);
 204        } else {
 205                /* Set initial sane state. */
 206                fpload(&init_fregs[0], &init_fsr);
 207                set_used_math();
 208        }
 209#else
 210        if(!used_math()) {
 211                fpload(&init_fregs[0], &init_fsr);
 212                set_used_math();
 213        } else {
 214                fpload(&current->thread.float_regs[0], &current->thread.fsr);
 215        }
 216        set_thread_flag(TIF_USEDFPU);
 217#endif
 218}
 219
 220static unsigned long fake_regs[32] __attribute__ ((aligned (8)));
 221static unsigned long fake_fsr;
 222static unsigned long fake_queue[32] __attribute__ ((aligned (8)));
 223static unsigned long fake_depth;
 224
 225extern int do_mathemu(struct pt_regs *, struct task_struct *);
 226
 227void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 228                 unsigned long psr)
 229{
 230        static int calls;
 231        siginfo_t info;
 232        unsigned long fsr;
 233        int ret = 0;
 234#ifndef CONFIG_SMP
 235        struct task_struct *fpt = last_task_used_math;
 236#else
 237        struct task_struct *fpt = current;
 238#endif
 239        put_psr(get_psr() | PSR_EF);
 240        /* If nobody owns the fpu right now, just clear the
 241         * error into our fake static buffer and hope it don't
 242         * happen again.  Thank you crashme...
 243         */
 244#ifndef CONFIG_SMP
 245        if(!fpt) {
 246#else
 247        if (!test_tsk_thread_flag(fpt, TIF_USEDFPU)) {
 248#endif
 249                fpsave(&fake_regs[0], &fake_fsr, &fake_queue[0], &fake_depth);
 250                regs->psr &= ~PSR_EF;
 251                return;
 252        }
 253        fpsave(&fpt->thread.float_regs[0], &fpt->thread.fsr,
 254               &fpt->thread.fpqueue[0], &fpt->thread.fpqdepth);
 255#ifdef DEBUG_FPU
 256        printk("Hmm, FP exception, fsr was %016lx\n", fpt->thread.fsr);
 257#endif
 258
 259        switch ((fpt->thread.fsr & 0x1c000)) {
 260        /* switch on the contents of the ftt [floating point trap type] field */
 261#ifdef DEBUG_FPU
 262        case (1 << 14):
 263                printk("IEEE_754_exception\n");
 264                break;
 265#endif
 266        case (2 << 14):  /* unfinished_FPop (underflow & co) */
 267        case (3 << 14):  /* unimplemented_FPop (quad stuff, maybe sqrt) */
 268                ret = do_mathemu(regs, fpt);
 269                break;
 270#ifdef DEBUG_FPU
 271        case (4 << 14):
 272                printk("sequence_error (OS bug...)\n");
 273                break;
 274        case (5 << 14):
 275                printk("hardware_error (uhoh!)\n");
 276                break;
 277        case (6 << 14):
 278                printk("invalid_fp_register (user error)\n");
 279                break;
 280#endif /* DEBUG_FPU */
 281        }
 282        /* If we successfully emulated the FPop, we pretend the trap never happened :-> */
 283        if (ret) {
 284                fpload(&current->thread.float_regs[0], &current->thread.fsr);
 285                return;
 286        }
 287        /* nope, better SIGFPE the offending process... */
 288               
 289#ifdef CONFIG_SMP
 290        clear_tsk_thread_flag(fpt, TIF_USEDFPU);
 291#endif
 292        if(psr & PSR_PS) {
 293                /* The first fsr store/load we tried trapped,
 294                 * the second one will not (we hope).
 295                 */
 296                printk("WARNING: FPU exception from kernel mode. at pc=%08lx\n",
 297                       regs->pc);
 298                regs->pc = regs->npc;
 299                regs->npc += 4;
 300                calls++;
 301                if(calls > 2)
 302                        die_if_kernel("Too many Penguin-FPU traps from kernel mode",
 303                                      regs);
 304                return;
 305        }
 306
 307        fsr = fpt->thread.fsr;
 308        info.si_signo = SIGFPE;
 309        info.si_errno = 0;
 310        info.si_addr = (void __user *)pc;
 311        info.si_trapno = 0;
 312        info.si_code = __SI_FAULT;
 313        if ((fsr & 0x1c000) == (1 << 14)) {
 314                if (fsr & 0x10)
 315                        info.si_code = FPE_FLTINV;
 316                else if (fsr & 0x08)
 317                        info.si_code = FPE_FLTOVF;
 318                else if (fsr & 0x04)
 319                        info.si_code = FPE_FLTUND;
 320                else if (fsr & 0x02)
 321                        info.si_code = FPE_FLTDIV;
 322                else if (fsr & 0x01)
 323                        info.si_code = FPE_FLTRES;
 324        }
 325        send_sig_info(SIGFPE, &info, fpt);
 326#ifndef CONFIG_SMP
 327        last_task_used_math = NULL;
 328#endif
 329        regs->psr &= ~PSR_EF;
 330        if(calls > 0)
 331                calls=0;
 332}
 333
 334void handle_tag_overflow(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 335                         unsigned long psr)
 336{
 337        siginfo_t info;
 338
 339        if(psr & PSR_PS)
 340                die_if_kernel("Penguin overflow trap from kernel mode", regs);
 341        info.si_signo = SIGEMT;
 342        info.si_errno = 0;
 343        info.si_code = EMT_TAGOVF;
 344        info.si_addr = (void __user *)pc;
 345        info.si_trapno = 0;
 346        send_sig_info(SIGEMT, &info, current);
 347}
 348
 349void handle_watchpoint(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 350                       unsigned long psr)
 351{
 352#ifdef TRAP_DEBUG
 353        printk("Watchpoint detected at PC %08lx NPC %08lx PSR %08lx\n",
 354               pc, npc, psr);
 355#endif
 356        if(psr & PSR_PS)
 357                panic("Tell me what a watchpoint trap is, and I'll then deal "
 358                      "with such a beast...");
 359}
 360
 361void handle_reg_access(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 362                       unsigned long psr)
 363{
 364        siginfo_t info;
 365
 366#ifdef TRAP_DEBUG
 367        printk("Register Access Exception at PC %08lx NPC %08lx PSR %08lx\n",
 368               pc, npc, psr);
 369#endif
 370        info.si_signo = SIGBUS;
 371        info.si_errno = 0;
 372        info.si_code = BUS_OBJERR;
 373        info.si_addr = (void __user *)pc;
 374        info.si_trapno = 0;
 375        force_sig_info(SIGBUS, &info, current);
 376}
 377
 378void handle_cp_disabled(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 379                        unsigned long psr)
 380{
 381        siginfo_t info;
 382
 383        info.si_signo = SIGILL;
 384        info.si_errno = 0;
 385        info.si_code = ILL_COPROC;
 386        info.si_addr = (void __user *)pc;
 387        info.si_trapno = 0;
 388        send_sig_info(SIGILL, &info, current);
 389}
 390
 391void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 392                         unsigned long psr)
 393{
 394        siginfo_t info;
 395
 396#ifdef TRAP_DEBUG
 397        printk("Co-Processor Exception at PC %08lx NPC %08lx PSR %08lx\n",
 398               pc, npc, psr);
 399#endif
 400        info.si_signo = SIGILL;
 401        info.si_errno = 0;
 402        info.si_code = ILL_COPROC;
 403        info.si_addr = (void __user *)pc;
 404        info.si_trapno = 0;
 405        send_sig_info(SIGILL, &info, current);
 406}
 407
 408void handle_hw_divzero(struct pt_regs *regs, unsigned long pc, unsigned long npc,
 409                       unsigned long psr)
 410{
 411        siginfo_t info;
 412
 413        info.si_signo = SIGFPE;
 414        info.si_errno = 0;
 415        info.si_code = FPE_INTDIV;
 416        info.si_addr = (void __user *)pc;
 417        info.si_trapno = 0;
 418        send_sig_info(SIGFPE, &info, current);
 419}
 420
 421#ifdef CONFIG_DEBUG_BUGVERBOSE
 422void do_BUG(const char *file, int line)
 423{
 424        // bust_spinlocks(1);   XXX Not in our original BUG()
 425        printk("kernel BUG at %s:%d!\n", file, line);
 426}
 427EXPORT_SYMBOL(do_BUG);
 428#endif
 429
 430/* Since we have our mappings set up, on multiprocessors we can spin them
 431 * up here so that timer interrupts work during initialization.
 432 */
 433
 434void trap_init(void)
 435{
 436        extern void thread_info_offsets_are_bolixed_pete(void);
 437
 438        /* Force linker to barf if mismatched */
 439        if (TI_UWINMASK    != offsetof(struct thread_info, uwinmask) ||
 440            TI_TASK        != offsetof(struct thread_info, task) ||
 441            TI_EXECDOMAIN  != offsetof(struct thread_info, exec_domain) ||
 442            TI_FLAGS       != offsetof(struct thread_info, flags) ||
 443            TI_CPU         != offsetof(struct thread_info, cpu) ||
 444            TI_PREEMPT     != offsetof(struct thread_info, preempt_count) ||
 445            TI_SOFTIRQ     != offsetof(struct thread_info, softirq_count) ||
 446            TI_HARDIRQ     != offsetof(struct thread_info, hardirq_count) ||
 447            TI_KSP         != offsetof(struct thread_info, ksp) ||
 448            TI_KPC         != offsetof(struct thread_info, kpc) ||
 449            TI_KPSR        != offsetof(struct thread_info, kpsr) ||
 450            TI_KWIM        != offsetof(struct thread_info, kwim) ||
 451            TI_REG_WINDOW  != offsetof(struct thread_info, reg_window) ||
 452            TI_RWIN_SPTRS  != offsetof(struct thread_info, rwbuf_stkptrs) ||
 453            TI_W_SAVED     != offsetof(struct thread_info, w_saved))
 454                thread_info_offsets_are_bolixed_pete();
 455
 456        /* Attach to the address space of init_task. */
 457        atomic_inc(&init_mm.mm_count);
 458        current->active_mm = &init_mm;
 459
 460        /* NOTE: Other cpus have this done as they are started
 461         *       up on SMP.
 462         */
 463}
 464