Pileus Git - ~andy/linux/blob - 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 <linux/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 *regs);
  47
  48 int show_unhandled_signals = 1;
  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_MASK_EA | PSW_MASK_BA));
 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(struct pt_regs *regs, const char *str)
 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: %04x [#%d] ", str, regs->int_code & 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, 0, regs->int_code & 0xffff, 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 inline void report_user_fault(struct pt_regs *regs, int signr)
 271 {
 272         if ((task_pid_nr(current) > 1) && !show_unhandled_signals)
 273                 return;
 274         if (!unhandled_signal(current, signr))
 275                 return;
 276         if (!printk_ratelimit())
 277                 return;
 278         printk("User process fault: interruption code 0x%X ", regs->int_code);
 279         print_vma_addr("in ", regs->psw.addr & PSW_ADDR_INSN);
 280         printk("\n");
 281         show_regs(regs);
 282 }
 283
 284 int is_valid_bugaddr(unsigned long addr)
 285 {
 286         return 1;
 287 }
 288
 289 static inline void __user *get_psw_address(struct pt_regs *regs)
 290 {
 291         return (void __user *)
 292                 ((regs->psw.addr - (regs->int_code >> 16)) & PSW_ADDR_INSN);
 293 }
 294
 295 static void __kprobes do_trap(struct pt_regs *regs,
 296                               int si_signo, int si_code, char *str)
 297 {
 298         siginfo_t info;
 299
 300         if (notify_die(DIE_TRAP, str, regs, 0,
 301                        regs->int_code, si_signo) == NOTIFY_STOP)
 302                 return;
 303
 304         if (regs->psw.mask & PSW_MASK_PSTATE) {
 305                 info.si_signo = si_signo;
 306                 info.si_errno = 0;
 307                 info.si_code = si_code;
 308                 info.si_addr = get_psw_address(regs);
 309                 force_sig_info(si_signo, &info, current);
 310                 report_user_fault(regs, si_signo);
 311         } else {
 312                 const struct exception_table_entry *fixup;
 313                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
 314                 if (fixup)
 315                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
 316                 else {
 317                         enum bug_trap_type btt;
 318
 319                         btt = report_bug(regs->psw.addr & PSW_ADDR_INSN, regs);
 320                         if (btt == BUG_TRAP_TYPE_WARN)
 321                                 return;
 322                         die(regs, str);
 323                 }
 324         }
 325 }
 326
 327 void __kprobes do_per_trap(struct pt_regs *regs)
 328 {
 329         siginfo_t info;
 330
 331         if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
 332                 return;
 333         if (!current->ptrace)
 334                 return;
 335         info.si_signo = SIGTRAP;
 336         info.si_errno = 0;
 337         info.si_code = TRAP_HWBKPT;
 338         info.si_addr =
 339                 (void __force __user *) current->thread.per_event.address;
 340         force_sig_info(SIGTRAP, &info, current);
 341 }
 342
 343 static void default_trap_handler(struct pt_regs *regs)
 344 {
 345         if (regs->psw.mask & PSW_MASK_PSTATE) {
 346                 report_user_fault(regs, SIGSEGV);
 347                 do_exit(SIGSEGV);
 348         } else
 349                 die(regs, "Unknown program exception");
 350 }
 351
 352 #define DO_ERROR_INFO(name, signr, sicode, str) \
 353 static void name(struct pt_regs *regs) \
 354 { \
 355         do_trap(regs, signr, sicode, str); \
 356 }
 357
 358 DO_ERROR_INFO(addressing_exception, SIGILL, ILL_ILLADR,
 359               "addressing exception")
 360 DO_ERROR_INFO(execute_exception, SIGILL, ILL_ILLOPN,
 361               "execute exception")
 362 DO_ERROR_INFO(divide_exception, SIGFPE, FPE_INTDIV,
 363               "fixpoint divide exception")
 364 DO_ERROR_INFO(overflow_exception, SIGFPE, FPE_INTOVF,
 365               "fixpoint overflow exception")
 366 DO_ERROR_INFO(hfp_overflow_exception, SIGFPE, FPE_FLTOVF,
 367               "HFP overflow exception")
 368 DO_ERROR_INFO(hfp_underflow_exception, SIGFPE, FPE_FLTUND,
 369               "HFP underflow exception")
 370 DO_ERROR_INFO(hfp_significance_exception, SIGFPE, FPE_FLTRES,
 371               "HFP significance exception")
 372 DO_ERROR_INFO(hfp_divide_exception, SIGFPE, FPE_FLTDIV,
 373               "HFP divide exception")
 374 DO_ERROR_INFO(hfp_sqrt_exception, SIGFPE, FPE_FLTINV,
 375               "HFP square root exception")
 376 DO_ERROR_INFO(operand_exception, SIGILL, ILL_ILLOPN,
 377               "operand exception")
 378 DO_ERROR_INFO(privileged_op, SIGILL, ILL_PRVOPC,
 379               "privileged operation")
 380 DO_ERROR_INFO(special_op_exception, SIGILL, ILL_ILLOPN,
 381               "special operation exception")
 382 DO_ERROR_INFO(translation_exception, SIGILL, ILL_ILLOPN,
 383               "translation exception")
 384
 385 static inline void do_fp_trap(struct pt_regs *regs, int fpc)
 386 {
 387         int si_code = 0;
 388         /* FPC[2] is Data Exception Code */
 389         if ((fpc & 0x00000300) == 0) {
 390                 /* bits 6 and 7 of DXC are 0 iff IEEE exception */
 391                 if (fpc & 0x8000) /* invalid fp operation */
 392                         si_code = FPE_FLTINV;
 393                 else if (fpc & 0x4000) /* div by 0 */
 394                         si_code = FPE_FLTDIV;
 395                 else if (fpc & 0x2000) /* overflow */
 396                         si_code = FPE_FLTOVF;
 397                 else if (fpc & 0x1000) /* underflow */
 398                         si_code = FPE_FLTUND;
 399                 else if (fpc & 0x0800) /* inexact */
 400                         si_code = FPE_FLTRES;
 401         }
 402         do_trap(regs, SIGFPE, si_code, "floating point exception");
 403 }
 404
 405 static void __kprobes illegal_op(struct pt_regs *regs)
 406 {
 407         siginfo_t info;
 408         __u8 opcode[6];
 409         __u16 __user *location;
 410         int signal = 0;
 411
 412         location = get_psw_address(regs);
 413
 414         if (regs->psw.mask & PSW_MASK_PSTATE) {
 415                 if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
 416                         return;
 417                 if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
 418                         if (current->ptrace) {
 419                                 info.si_signo = SIGTRAP;
 420                                 info.si_errno = 0;
 421                                 info.si_code = TRAP_BRKPT;
 422                                 info.si_addr = location;
 423                                 force_sig_info(SIGTRAP, &info, current);
 424                         } else
 425                                 signal = SIGILL;
 426 #ifdef CONFIG_MATHEMU
 427                 } else if (opcode[0] == 0xb3) {
 428                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 429                                 return;
 430                         signal = math_emu_b3(opcode, regs);
 431                 } else if (opcode[0] == 0xed) {
 432                         if (get_user(*((__u32 *) (opcode+2)),
 433                                      (__u32 __user *)(location+1)))
 434                                 return;
 435                         signal = math_emu_ed(opcode, regs);
 436                 } else if (*((__u16 *) opcode) == 0xb299) {
 437                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 438                                 return;
 439                         signal = math_emu_srnm(opcode, regs);
 440                 } else if (*((__u16 *) opcode) == 0xb29c) {
 441                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 442                                 return;
 443                         signal = math_emu_stfpc(opcode, regs);
 444                 } else if (*((__u16 *) opcode) == 0xb29d) {
 445                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 446                                 return;
 447                         signal = math_emu_lfpc(opcode, regs);
 448 #endif
 449                 } else
 450                         signal = SIGILL;
 451         } else {
 452                 /*
 453                  * If we get an illegal op in kernel mode, send it through the
 454                  * kprobes notifier. If kprobes doesn't pick it up, SIGILL
 455                  */
 456                 if (notify_die(DIE_BPT, "bpt", regs, 0,
 457                                3, SIGTRAP) != NOTIFY_STOP)
 458                         signal = SIGILL;
 459         }
 460
 461 #ifdef CONFIG_MATHEMU
 462         if (signal == SIGFPE)
 463                 do_fp_trap(regs, current->thread.fp_regs.fpc);
 464         else if (signal == SIGSEGV)
 465                 do_trap(regs, signal, SEGV_MAPERR, "user address fault");
 466         else
 467 #endif
 468         if (signal)
 469                 do_trap(regs, signal, ILL_ILLOPC, "illegal operation");
 470 }
 471
 472
 473 #ifdef CONFIG_MATHEMU
 474 void specification_exception(struct pt_regs *regs)
 475 {
 476         __u8 opcode[6];
 477         __u16 __user *location = NULL;
 478         int signal = 0;
 479
 480         location = (__u16 __user *) get_psw_address(regs);
 481
 482         if (regs->psw.mask & PSW_MASK_PSTATE) {
 483                 get_user(*((__u16 *) opcode), location);
 484                 switch (opcode[0]) {
 485                 case 0x28: /* LDR Rx,Ry   */
 486                         signal = math_emu_ldr(opcode);
 487                         break;
 488                 case 0x38: /* LER Rx,Ry   */
 489                         signal = math_emu_ler(opcode);
 490                         break;
 491                 case 0x60: /* STD R,D(X,B) */
 492                         get_user(*((__u16 *) (opcode+2)), location+1);
 493                         signal = math_emu_std(opcode, regs);
 494                         break;
 495                 case 0x68: /* LD R,D(X,B) */
 496                         get_user(*((__u16 *) (opcode+2)), location+1);
 497                         signal = math_emu_ld(opcode, regs);
 498                         break;
 499                 case 0x70: /* STE R,D(X,B) */
 500                         get_user(*((__u16 *) (opcode+2)), location+1);
 501                         signal = math_emu_ste(opcode, regs);
 502                         break;
 503                 case 0x78: /* LE R,D(X,B) */
 504                         get_user(*((__u16 *) (opcode+2)), location+1);
 505                         signal = math_emu_le(opcode, regs);
 506                         break;
 507                 default:
 508                         signal = SIGILL;
 509                         break;
 510                 }
 511         } else
 512                 signal = SIGILL;
 513
 514         if (signal == SIGFPE)
 515                 do_fp_trap(regs, current->thread.fp_regs.fpc);
 516         else if (signal)
 517                 do_trap(regs, signal, ILL_ILLOPN, "specification exception");
 518 }
 519 #else
 520 DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
 521               "specification exception");
 522 #endif
 523
 524 static void data_exception(struct pt_regs *regs)
 525 {
 526         __u16 __user *location;
 527         int signal = 0;
 528
 529         location = get_psw_address(regs);
 530
 531         if (MACHINE_HAS_IEEE)
 532                 asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
 533
 534 #ifdef CONFIG_MATHEMU
 535         else if (regs->psw.mask & PSW_MASK_PSTATE) {
 536                 __u8 opcode[6];
 537                 get_user(*((__u16 *) opcode), location);
 538                 switch (opcode[0]) {
 539                 case 0x28: /* LDR Rx,Ry   */
 540                         signal = math_emu_ldr(opcode);
 541                         break;
 542                 case 0x38: /* LER Rx,Ry   */
 543                         signal = math_emu_ler(opcode);
 544                         break;
 545                 case 0x60: /* STD R,D(X,B) */
 546                         get_user(*((__u16 *) (opcode+2)), location+1);
 547                         signal = math_emu_std(opcode, regs);
 548                         break;
 549                 case 0x68: /* LD R,D(X,B) */
 550                         get_user(*((__u16 *) (opcode+2)), location+1);
 551                         signal = math_emu_ld(opcode, regs);
 552                         break;
 553                 case 0x70: /* STE R,D(X,B) */
 554                         get_user(*((__u16 *) (opcode+2)), location+1);
 555                         signal = math_emu_ste(opcode, regs);
 556                         break;
 557                 case 0x78: /* LE R,D(X,B) */
 558                         get_user(*((__u16 *) (opcode+2)), location+1);
 559                         signal = math_emu_le(opcode, regs);
 560                         break;
 561                 case 0xb3:
 562                         get_user(*((__u16 *) (opcode+2)), location+1);
 563                         signal = math_emu_b3(opcode, regs);
 564                         break;
 565                 case 0xed:
 566                         get_user(*((__u32 *) (opcode+2)),
 567                                  (__u32 __user *)(location+1));
 568                         signal = math_emu_ed(opcode, regs);
 569                         break;
 570                 case 0xb2:
 571                         if (opcode[1] == 0x99) {
 572                                 get_user(*((__u16 *) (opcode+2)), location+1);
 573                                 signal = math_emu_srnm(opcode, regs);
 574                         } else if (opcode[1] == 0x9c) {
 575                                 get_user(*((__u16 *) (opcode+2)), location+1);
 576                                 signal = math_emu_stfpc(opcode, regs);
 577                         } else if (opcode[1] == 0x9d) {
 578                                 get_user(*((__u16 *) (opcode+2)), location+1);
 579                                 signal = math_emu_lfpc(opcode, regs);
 580                         } else
 581                                 signal = SIGILL;
 582                         break;
 583                 default:
 584                         signal = SIGILL;
 585                         break;
 586                 }
 587         }
 588 #endif
 589         if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
 590                 signal = SIGFPE;
 591         else
 592                 signal = SIGILL;
 593         if (signal == SIGFPE)
 594                 do_fp_trap(regs, current->thread.fp_regs.fpc);
 595         else if (signal)
 596                 do_trap(regs, signal, ILL_ILLOPN, "data exception");
 597 }
 598
 599 static void space_switch_exception(struct pt_regs *regs)
 600 {
 601         /* Set user psw back to home space mode. */
 602         if (regs->psw.mask & PSW_MASK_PSTATE)
 603                 regs->psw.mask |= PSW_ASC_HOME;
 604         /* Send SIGILL. */
 605         do_trap(regs, SIGILL, ILL_PRVOPC, "space switch event");
 606 }
 607
 608 void __kprobes kernel_stack_overflow(struct pt_regs * regs)
 609 {
 610         bust_spinlocks(1);
 611         printk("Kernel stack overflow.\n");
 612         show_regs(regs);
 613         bust_spinlocks(0);
 614         panic("Corrupt kernel stack, can't continue.");
 615 }
 616
 617 /* init is done in lowcore.S and head.S */
 618
 619 void __init trap_init(void)
 620 {
 621         int i;
 622
 623         for (i = 0; i < 128; i++)
 624           pgm_check_table[i] = &default_trap_handler;
 625         pgm_check_table[1] = &illegal_op;
 626         pgm_check_table[2] = &privileged_op;
 627         pgm_check_table[3] = &execute_exception;
 628         pgm_check_table[4] = &do_protection_exception;
 629         pgm_check_table[5] = &addressing_exception;
 630         pgm_check_table[6] = &specification_exception;
 631         pgm_check_table[7] = &data_exception;
 632         pgm_check_table[8] = &overflow_exception;
 633         pgm_check_table[9] = &divide_exception;
 634         pgm_check_table[0x0A] = &overflow_exception;
 635         pgm_check_table[0x0B] = &divide_exception;
 636         pgm_check_table[0x0C] = &hfp_overflow_exception;
 637         pgm_check_table[0x0D] = &hfp_underflow_exception;
 638         pgm_check_table[0x0E] = &hfp_significance_exception;
 639         pgm_check_table[0x0F] = &hfp_divide_exception;
 640         pgm_check_table[0x10] = &do_dat_exception;
 641         pgm_check_table[0x11] = &do_dat_exception;
 642         pgm_check_table[0x12] = &translation_exception;
 643         pgm_check_table[0x13] = &special_op_exception;
 644 #ifdef CONFIG_64BIT
 645         pgm_check_table[0x38] = &do_asce_exception;
 646         pgm_check_table[0x39] = &do_dat_exception;
 647         pgm_check_table[0x3A] = &do_dat_exception;
 648         pgm_check_table[0x3B] = &do_dat_exception;
 649 #endif /* CONFIG_64BIT */
 650         pgm_check_table[0x15] = &operand_exception;
 651         pgm_check_table[0x1C] = &space_switch_exception;
 652         pgm_check_table[0x1D] = &hfp_sqrt_exception;
 653         /* Enable machine checks early. */
 654         local_mcck_enable();
 655 }