arch/s390/kernel/traps.c

   1 /*
   2  *  arch/s390/kernel/traps.c
   3  *
   4  *  S390 version
   5  *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
   6  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
   7  *               Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
   8  *
   9  *  Derived from "arch/i386/kernel/traps.c"
  10  *    Copyright (C) 1991, 1992 Linus Torvalds
  11  */
  12
  13 /*
  14  * 'Traps.c' handles hardware traps and faults after we have saved some
  15  * state in 'asm.s'.
  16  */
  17 #include <linux/sched.h>
  18 #include <linux/kernel.h>
  19 #include <linux/string.h>
  20 #include <linux/errno.h>
  21 #include <linux/ptrace.h>
  22 #include <linux/timer.h>
  23 #include <linux/mm.h>
  24 #include <linux/smp.h>
  25 #include <linux/init.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/seq_file.h>
  28 #include <linux/delay.h>
  29 #include <linux/module.h>
  30 #include <linux/kdebug.h>
  31 #include <linux/kallsyms.h>
  32 #include <linux/reboot.h>
  33 #include <linux/kprobes.h>
  34 #include <linux/bug.h>
  35 #include <linux/utsname.h>
  36 #include <asm/system.h>
  37 #include <asm/uaccess.h>
  38 #include <asm/io.h>
  39 #include <asm/atomic.h>
  40 #include <asm/mathemu.h>
  41 #include <asm/cpcmd.h>
  42 #include <asm/lowcore.h>
  43 #include <asm/debug.h>
  44 #include "entry.h"
  45
  46 void (*pgm_check_table[128])(struct pt_regs *, long, unsigned long);
  47
  48 int show_unhandled_signals;
  49
  50 #define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
  51
  52 #ifndef CONFIG_64BIT
  53 #define LONG "%08lx "
  54 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
  55 static int kstack_depth_to_print = 12;
  56 #else /* CONFIG_64BIT */
  57 #define LONG "%016lx "
  58 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
  59 static int kstack_depth_to_print = 20;
  60 #endif /* CONFIG_64BIT */
  61
  62 /*
  63  * For show_trace we have tree different stack to consider:
  64  *   - the panic stack which is used if the kernel stack has overflown
  65  *   - the asynchronous interrupt stack (cpu related)
  66  *   - the synchronous kernel stack (process related)
  67  * The stack trace can start at any of the three stack and can potentially
  68  * touch all of them. The order is: panic stack, async stack, sync stack.
  69  */
  70 static unsigned long
  71 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
  72 {
  73         struct stack_frame *sf;
  74         struct pt_regs *regs;
  75
  76         while (1) {
  77                 sp = sp & PSW_ADDR_INSN;
  78                 if (sp < low || sp > high - sizeof(*sf))
  79                         return sp;
  80                 sf = (struct stack_frame *) sp;
  81                 printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
  82                 print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
  83                 /* Follow the backchain. */
  84                 while (1) {
  85                         low = sp;
  86                         sp = sf->back_chain & PSW_ADDR_INSN;
  87                         if (!sp)
  88                                 break;
  89                         if (sp <= low || sp > high - sizeof(*sf))
  90                                 return sp;
  91                         sf = (struct stack_frame *) sp;
  92                         printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
  93                         print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
  94                 }
  95                 /* Zero backchain detected, check for interrupt frame. */
  96                 sp = (unsigned long) (sf + 1);
  97                 if (sp <= low || sp > high - sizeof(*regs))
  98                         return sp;
  99                 regs = (struct pt_regs *) sp;
 100                 printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
 101                 print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
 102                 low = sp;
 103                 sp = regs->gprs[15];
 104         }
 105 }
 106
 107 static void show_trace(struct task_struct *task, unsigned long *stack)
 108 {
 109         register unsigned long __r15 asm ("15");
 110         unsigned long sp;
 111
 112         sp = (unsigned long) stack;
 113         if (!sp)
 114                 sp = task ? task->thread.ksp : __r15;
 115         printk("Call Trace:\n");
 116 #ifdef CONFIG_CHECK_STACK
 117         sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
 118                           S390_lowcore.panic_stack);
 119 #endif
 120         sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
 121                           S390_lowcore.async_stack);
 122         if (task)
 123                 __show_trace(sp, (unsigned long) task_stack_page(task),
 124                              (unsigned long) task_stack_page(task) + THREAD_SIZE);
 125         else
 126                 __show_trace(sp, S390_lowcore.thread_info,
 127                              S390_lowcore.thread_info + THREAD_SIZE);
 128         if (!task)
 129                 task = current;
 130         debug_show_held_locks(task);
 131 }
 132
 133 void show_stack(struct task_struct *task, unsigned long *sp)
 134 {
 135         register unsigned long * __r15 asm ("15");
 136         unsigned long *stack;
 137         int i;
 138
 139         if (!sp)
 140                 stack = task ? (unsigned long *) task->thread.ksp : __r15;
 141         else
 142                 stack = sp;
 143
 144         for (i = 0; i < kstack_depth_to_print; i++) {
 145                 if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
 146                         break;
 147                 if (i && ((i * sizeof (long) % 32) == 0))
 148                         printk("\n       ");
 149                 printk(LONG, *stack++);
 150         }
 151         printk("\n");
 152         show_trace(task, sp);
 153 }
 154
 155 static void show_last_breaking_event(struct pt_regs *regs)
 156 {
 157 #ifdef CONFIG_64BIT
 158         printk("Last Breaking-Event-Address:\n");
 159         printk(" [<%016lx>] ", regs->args[0] & PSW_ADDR_INSN);
 160         print_symbol("%s\n", regs->args[0] & PSW_ADDR_INSN);
 161 #endif
 162 }
 163
 164 /*
 165  * The architecture-independent dump_stack generator
 166  */
 167 void dump_stack(void)
 168 {
 169         printk("CPU: %d %s %s %.*s\n",
 170                task_thread_info(current)->cpu, print_tainted(),
 171                init_utsname()->release,
 172                (int)strcspn(init_utsname()->version, " "),
 173                init_utsname()->version);
 174         printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
 175                current->comm, current->pid, current,
 176                (void *) current->thread.ksp);
 177         show_stack(NULL, NULL);
 178 }
 179 EXPORT_SYMBOL(dump_stack);
 180
 181 static inline int mask_bits(struct pt_regs *regs, unsigned long bits)
 182 {
 183         return (regs->psw.mask & bits) / ((~bits + 1) & bits);
 184 }
 185
 186 void show_registers(struct pt_regs *regs)
 187 {
 188         char *mode;
 189
 190         mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
 191         printk("%s PSW : %p %p",
 192                mode, (void *) regs->psw.mask,
 193                (void *) regs->psw.addr);
 194         print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
 195         printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
 196                "P:%x AS:%x CC:%x PM:%x", mask_bits(regs, PSW_MASK_PER),
 197                mask_bits(regs, PSW_MASK_DAT), mask_bits(regs, PSW_MASK_IO),
 198                mask_bits(regs, PSW_MASK_EXT), mask_bits(regs, PSW_MASK_KEY),
 199                mask_bits(regs, PSW_MASK_MCHECK), mask_bits(regs, PSW_MASK_WAIT),
 200                mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC),
 201                mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM));
 202 #ifdef CONFIG_64BIT
 203         printk(" EA:%x", mask_bits(regs, PSW_BASE_BITS));
 204 #endif
 205         printk("\n%s GPRS: " FOURLONG, mode,
 206                regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
 207         printk("           " FOURLONG,
 208                regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
 209         printk("           " FOURLONG,
 210                regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
 211         printk("           " FOURLONG,
 212                regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
 213
 214         show_code(regs);
 215 }
 216
 217 void show_regs(struct pt_regs *regs)
 218 {
 219         print_modules();
 220         printk("CPU: %d %s %s %.*s\n",
 221                task_thread_info(current)->cpu, print_tainted(),
 222                init_utsname()->release,
 223                (int)strcspn(init_utsname()->version, " "),
 224                init_utsname()->version);
 225         printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
 226                current->comm, current->pid, current,
 227                (void *) current->thread.ksp);
 228         show_registers(regs);
 229         /* Show stack backtrace if pt_regs is from kernel mode */
 230         if (!(regs->psw.mask & PSW_MASK_PSTATE))
 231                 show_trace(NULL, (unsigned long *) regs->gprs[15]);
 232         show_last_breaking_event(regs);
 233 }
 234
 235 static DEFINE_SPINLOCK(die_lock);
 236
 237 void die(const char * str, struct pt_regs * regs, long err)
 238 {
 239         static int die_counter;
 240
 241         oops_enter();
 242         debug_stop_all();
 243         console_verbose();
 244         spin_lock_irq(&die_lock);
 245         bust_spinlocks(1);
 246         printk("%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
 247 #ifdef CONFIG_PREEMPT
 248         printk("PREEMPT ");
 249 #endif
 250 #ifdef CONFIG_SMP
 251         printk("SMP ");
 252 #endif
 253 #ifdef CONFIG_DEBUG_PAGEALLOC
 254         printk("DEBUG_PAGEALLOC");
 255 #endif
 256         printk("\n");
 257         notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
 258         show_regs(regs);
 259         bust_spinlocks(0);
 260         add_taint(TAINT_DIE);
 261         spin_unlock_irq(&die_lock);
 262         if (in_interrupt())
 263                 panic("Fatal exception in interrupt");
 264         if (panic_on_oops)
 265                 panic("Fatal exception: panic_on_oops");
 266         oops_exit();
 267         do_exit(SIGSEGV);
 268 }
 269
 270 static void inline report_user_fault(struct pt_regs *regs, long int_code,
 271                                      int signr)
 272 {
 273         if ((task_pid_nr(current) > 1) && !show_unhandled_signals)
 274                 return;
 275         if (!unhandled_signal(current, signr))
 276                 return;
 277         if (!printk_ratelimit())
 278                 return;
 279         printk("User process fault: interruption code 0x%lX ", int_code);
 280         print_vma_addr("in ", regs->psw.addr & PSW_ADDR_INSN);
 281         printk("\n");
 282         show_regs(regs);
 283 }
 284
 285 int is_valid_bugaddr(unsigned long addr)
 286 {
 287         return 1;
 288 }
 289
 290 static inline void __kprobes do_trap(long pgm_int_code, int signr, char *str,
 291                                      struct pt_regs *regs, siginfo_t *info)
 292 {
 293         if (notify_die(DIE_TRAP, str, regs, pgm_int_code,
 294                        pgm_int_code, signr) == NOTIFY_STOP)
 295                 return;
 296
 297         if (regs->psw.mask & PSW_MASK_PSTATE) {
 298                 struct task_struct *tsk = current;
 299
 300                 tsk->thread.trap_no = pgm_int_code & 0xffff;
 301                 force_sig_info(signr, info, tsk);
 302                 report_user_fault(regs, pgm_int_code, signr);
 303         } else {
 304                 const struct exception_table_entry *fixup;
 305                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
 306                 if (fixup)
 307                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
 308                 else {
 309                         enum bug_trap_type btt;
 310
 311                         btt = report_bug(regs->psw.addr & PSW_ADDR_INSN, regs);
 312                         if (btt == BUG_TRAP_TYPE_WARN)
 313                                 return;
 314                         die(str, regs, pgm_int_code);
 315                 }
 316         }
 317 }
 318
 319 static inline void __user *get_psw_address(struct pt_regs *regs,
 320                                            long pgm_int_code)
 321 {
 322         return (void __user *)
 323                 ((regs->psw.addr - (pgm_int_code >> 16)) & PSW_ADDR_INSN);
 324 }
 325
 326 void __kprobes do_per_trap(struct pt_regs *regs)
 327 {
 328         siginfo_t info;
 329
 330         if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
 331                 return;
 332         if (!current->ptrace)
 333                 return;
 334         info.si_signo = SIGTRAP;
 335         info.si_errno = 0;
 336         info.si_code = TRAP_HWBKPT;
 337         info.si_addr = (void *) current->thread.per_event.address;
 338         force_sig_info(SIGTRAP, &info, current);
 339 }
 340
 341 static void default_trap_handler(struct pt_regs *regs, long pgm_int_code,
 342                                  unsigned long trans_exc_code)
 343 {
 344         if (regs->psw.mask & PSW_MASK_PSTATE) {
 345                 report_user_fault(regs, pgm_int_code, SIGSEGV);
 346                 do_exit(SIGSEGV);
 347         } else
 348                 die("Unknown program exception", regs, pgm_int_code);
 349 }
 350
 351 #define DO_ERROR_INFO(name, signr, sicode, str) \
 352 static void name(struct pt_regs *regs, long pgm_int_code, \
 353                  unsigned long trans_exc_code) \
 354 { \
 355         siginfo_t info; \
 356         info.si_signo = signr; \
 357         info.si_errno = 0; \
 358         info.si_code = sicode; \
 359         info.si_addr = get_psw_address(regs, pgm_int_code); \
 360         do_trap(pgm_int_code, signr, str, regs, &info);     \
 361 }
 362
 363 DO_ERROR_INFO(addressing_exception, SIGILL, ILL_ILLADR,
 364               "addressing exception")
 365 DO_ERROR_INFO(execute_exception, SIGILL, ILL_ILLOPN,
 366               "execute exception")
 367 DO_ERROR_INFO(divide_exception, SIGFPE, FPE_INTDIV,
 368               "fixpoint divide exception")
 369 DO_ERROR_INFO(overflow_exception, SIGFPE, FPE_INTOVF,
 370               "fixpoint overflow exception")
 371 DO_ERROR_INFO(hfp_overflow_exception, SIGFPE, FPE_FLTOVF,
 372               "HFP overflow exception")
 373 DO_ERROR_INFO(hfp_underflow_exception, SIGFPE, FPE_FLTUND,
 374               "HFP underflow exception")
 375 DO_ERROR_INFO(hfp_significance_exception, SIGFPE, FPE_FLTRES,
 376               "HFP significance exception")
 377 DO_ERROR_INFO(hfp_divide_exception, SIGFPE, FPE_FLTDIV,
 378               "HFP divide exception")
 379 DO_ERROR_INFO(hfp_sqrt_exception, SIGFPE, FPE_FLTINV,
 380               "HFP square root exception")
 381 DO_ERROR_INFO(operand_exception, SIGILL, ILL_ILLOPN,
 382               "operand exception")
 383 DO_ERROR_INFO(privileged_op, SIGILL, ILL_PRVOPC,
 384               "privileged operation")
 385 DO_ERROR_INFO(special_op_exception, SIGILL, ILL_ILLOPN,
 386               "special operation exception")
 387 DO_ERROR_INFO(translation_exception, SIGILL, ILL_ILLOPN,
 388               "translation exception")
 389
 390 static inline void do_fp_trap(struct pt_regs *regs, void __user *location,
 391                               int fpc, long pgm_int_code)
 392 {
 393         siginfo_t si;
 394
 395         si.si_signo = SIGFPE;
 396         si.si_errno = 0;
 397         si.si_addr = location;
 398         si.si_code = 0;
 399         /* FPC[2] is Data Exception Code */
 400         if ((fpc & 0x00000300) == 0) {
 401                 /* bits 6 and 7 of DXC are 0 iff IEEE exception */
 402                 if (fpc & 0x8000) /* invalid fp operation */
 403                         si.si_code = FPE_FLTINV;
 404                 else if (fpc & 0x4000) /* div by 0 */
 405                         si.si_code = FPE_FLTDIV;
 406                 else if (fpc & 0x2000) /* overflow */
 407                         si.si_code = FPE_FLTOVF;
 408                 else if (fpc & 0x1000) /* underflow */
 409                         si.si_code = FPE_FLTUND;
 410                 else if (fpc & 0x0800) /* inexact */
 411                         si.si_code = FPE_FLTRES;
 412         }
 413         do_trap(pgm_int_code, SIGFPE,
 414                 "floating point exception", regs, &si);
 415 }
 416
 417 static void __kprobes illegal_op(struct pt_regs *regs, long pgm_int_code,
 418                                  unsigned long trans_exc_code)
 419 {
 420         siginfo_t info;
 421         __u8 opcode[6];
 422         __u16 __user *location;
 423         int signal = 0;
 424
 425         location = get_psw_address(regs, pgm_int_code);
 426
 427         if (regs->psw.mask & PSW_MASK_PSTATE) {
 428                 if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
 429                         return;
 430                 if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
 431                         if (current->ptrace) {
 432                                 info.si_signo = SIGTRAP;
 433                                 info.si_errno = 0;
 434                                 info.si_code = TRAP_BRKPT;
 435                                 info.si_addr = location;
 436                                 force_sig_info(SIGTRAP, &info, current);
 437                         } else
 438                                 signal = SIGILL;
 439 #ifdef CONFIG_MATHEMU
 440                 } else if (opcode[0] == 0xb3) {
 441                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 442                                 return;
 443                         signal = math_emu_b3(opcode, regs);
 444                 } else if (opcode[0] == 0xed) {
 445                         if (get_user(*((__u32 *) (opcode+2)),
 446                                      (__u32 __user *)(location+1)))
 447                                 return;
 448                         signal = math_emu_ed(opcode, regs);
 449                 } else if (*((__u16 *) opcode) == 0xb299) {
 450                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 451                                 return;
 452                         signal = math_emu_srnm(opcode, regs);
 453                 } else if (*((__u16 *) opcode) == 0xb29c) {
 454                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 455                                 return;
 456                         signal = math_emu_stfpc(opcode, regs);
 457                 } else if (*((__u16 *) opcode) == 0xb29d) {
 458                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 459                                 return;
 460                         signal = math_emu_lfpc(opcode, regs);
 461 #endif
 462                 } else
 463                         signal = SIGILL;
 464         } else {
 465                 /*
 466                  * If we get an illegal op in kernel mode, send it through the
 467                  * kprobes notifier. If kprobes doesn't pick it up, SIGILL
 468                  */
 469                 if (notify_die(DIE_BPT, "bpt", regs, pgm_int_code,
 470                                3, SIGTRAP) != NOTIFY_STOP)
 471                         signal = SIGILL;
 472         }
 473
 474 #ifdef CONFIG_MATHEMU
 475         if (signal == SIGFPE)
 476                 do_fp_trap(regs, location,
 477                            current->thread.fp_regs.fpc, pgm_int_code);
 478         else if (signal == SIGSEGV) {
 479                 info.si_signo = signal;
 480                 info.si_errno = 0;
 481                 info.si_code = SEGV_MAPERR;
 482                 info.si_addr = (void __user *) location;
 483                 do_trap(pgm_int_code, signal,
 484                         "user address fault", regs, &info);
 485         } else
 486 #endif
 487         if (signal) {
 488                 info.si_signo = signal;
 489                 info.si_errno = 0;
 490                 info.si_code = ILL_ILLOPC;
 491                 info.si_addr = (void __user *) location;
 492                 do_trap(pgm_int_code, signal,
 493                         "illegal operation", regs, &info);
 494         }
 495 }
 496
 497
 498 #ifdef CONFIG_MATHEMU
 499 void specification_exception(struct pt_regs *regs, long pgm_int_code,
 500                              unsigned long trans_exc_code)
 501 {
 502         __u8 opcode[6];
 503         __u16 __user *location = NULL;
 504         int signal = 0;
 505
 506         location = (__u16 __user *) get_psw_address(regs, pgm_int_code);
 507
 508         if (regs->psw.mask & PSW_MASK_PSTATE) {
 509                 get_user(*((__u16 *) opcode), location);
 510                 switch (opcode[0]) {
 511                 case 0x28: /* LDR Rx,Ry   */
 512                         signal = math_emu_ldr(opcode);
 513                         break;
 514                 case 0x38: /* LER Rx,Ry   */
 515                         signal = math_emu_ler(opcode);
 516                         break;
 517                 case 0x60: /* STD R,D(X,B) */
 518                         get_user(*((__u16 *) (opcode+2)), location+1);
 519                         signal = math_emu_std(opcode, regs);
 520                         break;
 521                 case 0x68: /* LD R,D(X,B) */
 522                         get_user(*((__u16 *) (opcode+2)), location+1);
 523                         signal = math_emu_ld(opcode, regs);
 524                         break;
 525                 case 0x70: /* STE R,D(X,B) */
 526                         get_user(*((__u16 *) (opcode+2)), location+1);
 527                         signal = math_emu_ste(opcode, regs);
 528                         break;
 529                 case 0x78: /* LE R,D(X,B) */
 530                         get_user(*((__u16 *) (opcode+2)), location+1);
 531                         signal = math_emu_le(opcode, regs);
 532                         break;
 533                 default:
 534                         signal = SIGILL;
 535                         break;
 536                 }
 537         } else
 538                 signal = SIGILL;
 539
 540         if (signal == SIGFPE)
 541                 do_fp_trap(regs, location,
 542                            current->thread.fp_regs.fpc, pgm_int_code);
 543         else if (signal) {
 544                 siginfo_t info;
 545                 info.si_signo = signal;
 546                 info.si_errno = 0;
 547                 info.si_code = ILL_ILLOPN;
 548                 info.si_addr = location;
 549                 do_trap(pgm_int_code, signal,
 550                         "specification exception", regs, &info);
 551         }
 552 }
 553 #else
 554 DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
 555               "specification exception");
 556 #endif
 557
 558 static void data_exception(struct pt_regs *regs, long pgm_int_code,
 559                            unsigned long trans_exc_code)
 560 {
 561         __u16 __user *location;
 562         int signal = 0;
 563
 564         location = get_psw_address(regs, pgm_int_code);
 565
 566         if (MACHINE_HAS_IEEE)
 567                 asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
 568
 569 #ifdef CONFIG_MATHEMU
 570         else if (regs->psw.mask & PSW_MASK_PSTATE) {
 571                 __u8 opcode[6];
 572                 get_user(*((__u16 *) opcode), location);
 573                 switch (opcode[0]) {
 574                 case 0x28: /* LDR Rx,Ry   */
 575                         signal = math_emu_ldr(opcode);
 576                         break;
 577                 case 0x38: /* LER Rx,Ry   */
 578                         signal = math_emu_ler(opcode);
 579                         break;
 580                 case 0x60: /* STD R,D(X,B) */
 581                         get_user(*((__u16 *) (opcode+2)), location+1);
 582                         signal = math_emu_std(opcode, regs);
 583                         break;
 584                 case 0x68: /* LD R,D(X,B) */
 585                         get_user(*((__u16 *) (opcode+2)), location+1);
 586                         signal = math_emu_ld(opcode, regs);
 587                         break;
 588                 case 0x70: /* STE R,D(X,B) */
 589                         get_user(*((__u16 *) (opcode+2)), location+1);
 590                         signal = math_emu_ste(opcode, regs);
 591                         break;
 592                 case 0x78: /* LE R,D(X,B) */
 593                         get_user(*((__u16 *) (opcode+2)), location+1);
 594                         signal = math_emu_le(opcode, regs);
 595                         break;
 596                 case 0xb3:
 597                         get_user(*((__u16 *) (opcode+2)), location+1);
 598                         signal = math_emu_b3(opcode, regs);
 599                         break;
 600                 case 0xed:
 601                         get_user(*((__u32 *) (opcode+2)),
 602                                  (__u32 __user *)(location+1));
 603                         signal = math_emu_ed(opcode, regs);
 604                         break;
 605                 case 0xb2:
 606                         if (opcode[1] == 0x99) {
 607                                 get_user(*((__u16 *) (opcode+2)), location+1);
 608                                 signal = math_emu_srnm(opcode, regs);
 609                         } else if (opcode[1] == 0x9c) {
 610                                 get_user(*((__u16 *) (opcode+2)), location+1);
 611                                 signal = math_emu_stfpc(opcode, regs);
 612                         } else if (opcode[1] == 0x9d) {
 613                                 get_user(*((__u16 *) (opcode+2)), location+1);
 614                                 signal = math_emu_lfpc(opcode, regs);
 615                         } else
 616                                 signal = SIGILL;
 617                         break;
 618                 default:
 619                         signal = SIGILL;
 620                         break;
 621                 }
 622         }
 623 #endif
 624         if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
 625                 signal = SIGFPE;
 626         else
 627                 signal = SIGILL;
 628         if (signal == SIGFPE)
 629                 do_fp_trap(regs, location,
 630                            current->thread.fp_regs.fpc, pgm_int_code);
 631         else if (signal) {
 632                 siginfo_t info;
 633                 info.si_signo = signal;
 634                 info.si_errno = 0;
 635                 info.si_code = ILL_ILLOPN;
 636                 info.si_addr = location;
 637                 do_trap(pgm_int_code, signal, "data exception", regs, &info);
 638         }
 639 }
 640
 641 static void space_switch_exception(struct pt_regs *regs, long pgm_int_code,
 642                                    unsigned long trans_exc_code)
 643 {
 644         siginfo_t info;
 645
 646         /* Set user psw back to home space mode. */
 647         if (regs->psw.mask & PSW_MASK_PSTATE)
 648                 regs->psw.mask |= PSW_ASC_HOME;
 649         /* Send SIGILL. */
 650         info.si_signo = SIGILL;
 651         info.si_errno = 0;
 652         info.si_code = ILL_PRVOPC;
 653         info.si_addr = get_psw_address(regs, pgm_int_code);
 654         do_trap(pgm_int_code, SIGILL, "space switch event", regs, &info);
 655 }
 656
 657 void __kprobes kernel_stack_overflow(struct pt_regs * regs)
 658 {
 659         bust_spinlocks(1);
 660         printk("Kernel stack overflow.\n");
 661         show_regs(regs);
 662         bust_spinlocks(0);
 663         panic("Corrupt kernel stack, can't continue.");
 664 }
 665
 666 /* init is done in lowcore.S and head.S */
 667
 668 void __init trap_init(void)
 669 {
 670         int i;
 671
 672         for (i = 0; i < 128; i++)
 673           pgm_check_table[i] = &default_trap_handler;
 674         pgm_check_table[1] = &illegal_op;
 675         pgm_check_table[2] = &privileged_op;
 676         pgm_check_table[3] = &execute_exception;
 677         pgm_check_table[4] = &do_protection_exception;
 678         pgm_check_table[5] = &addressing_exception;
 679         pgm_check_table[6] = &specification_exception;
 680         pgm_check_table[7] = &data_exception;
 681         pgm_check_table[8] = &overflow_exception;
 682         pgm_check_table[9] = &divide_exception;
 683         pgm_check_table[0x0A] = &overflow_exception;
 684         pgm_check_table[0x0B] = &divide_exception;
 685         pgm_check_table[0x0C] = &hfp_overflow_exception;
 686         pgm_check_table[0x0D] = &hfp_underflow_exception;
 687         pgm_check_table[0x0E] = &hfp_significance_exception;
 688         pgm_check_table[0x0F] = &hfp_divide_exception;
 689         pgm_check_table[0x10] = &do_dat_exception;
 690         pgm_check_table[0x11] = &do_dat_exception;
 691         pgm_check_table[0x12] = &translation_exception;
 692         pgm_check_table[0x13] = &special_op_exception;
 693 #ifdef CONFIG_64BIT
 694         pgm_check_table[0x38] = &do_asce_exception;
 695         pgm_check_table[0x39] = &do_dat_exception;
 696         pgm_check_table[0x3A] = &do_dat_exception;
 697         pgm_check_table[0x3B] = &do_dat_exception;
 698 #endif /* CONFIG_64BIT */
 699         pgm_check_table[0x15] = &operand_exception;
 700         pgm_check_table[0x1C] = &space_switch_exception;
 701         pgm_check_table[0x1D] = &hfp_sqrt_exception;
 702         /* Enable machine checks early. */
 703         local_mcck_enable();
 704 }