arch/s390/kernel/traps.c

   1 /*
   2  *  S390 version
   3  *    Copyright IBM Corp. 1999, 2000
   4  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
   5  *               Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
   6  *
   7  *  Derived from "arch/i386/kernel/traps.c"
   8  *    Copyright (C) 1991, 1992 Linus Torvalds
   9  */
  10
  11 /*
  12  * 'Traps.c' handles hardware traps and faults after we have saved some
  13  * state in 'asm.s'.
  14  */
  15 #include <linux/sched.h>
  16 #include <linux/kernel.h>
  17 #include <linux/string.h>
  18 #include <linux/errno.h>
  19 #include <linux/ptrace.h>
  20 #include <linux/timer.h>
  21 #include <linux/mm.h>
  22 #include <linux/smp.h>
  23 #include <linux/init.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/seq_file.h>
  26 #include <linux/delay.h>
  27 #include <linux/module.h>
  28 #include <linux/kdebug.h>
  29 #include <linux/kallsyms.h>
  30 #include <linux/reboot.h>
  31 #include <linux/kprobes.h>
  32 #include <linux/bug.h>
  33 #include <linux/utsname.h>
  34 #include <asm/uaccess.h>
  35 #include <asm/io.h>
  36 #include <linux/atomic.h>
  37 #include <asm/mathemu.h>
  38 #include <asm/cpcmd.h>
  39 #include <asm/lowcore.h>
  40 #include <asm/debug.h>
  41 #include <asm/ipl.h>
  42 #include "entry.h"
  43
  44 void (*pgm_check_table[128])(struct pt_regs *regs);
  45
  46 int show_unhandled_signals = 1;
  47
  48 #define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
  49
  50 #ifndef CONFIG_64BIT
  51 #define LONG "%08lx "
  52 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
  53 static int kstack_depth_to_print = 12;
  54 #else /* CONFIG_64BIT */
  55 #define LONG "%016lx "
  56 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
  57 static int kstack_depth_to_print = 20;
  58 #endif /* CONFIG_64BIT */
  59
  60 static inline void __user *get_trap_ip(struct pt_regs *regs)
  61 {
  62 #ifdef CONFIG_64BIT
  63         unsigned long address;
  64
  65         if (regs->int_code & 0x200)
  66                 address = *(unsigned long *)(current->thread.trap_tdb + 24);
  67         else
  68                 address = regs->psw.addr;
  69         return (void __user *)
  70                 ((address - (regs->int_code >> 16)) & PSW_ADDR_INSN);
  71 #else
  72         return (void __user *)
  73                 ((regs->psw.addr - (regs->int_code >> 16)) & PSW_ADDR_INSN);
  74 #endif
  75 }
  76
  77 /*
  78  * For show_trace we have tree different stack to consider:
  79  *   - the panic stack which is used if the kernel stack has overflown
  80  *   - the asynchronous interrupt stack (cpu related)
  81  *   - the synchronous kernel stack (process related)
  82  * The stack trace can start at any of the three stack and can potentially
  83  * touch all of them. The order is: panic stack, async stack, sync stack.
  84  */
  85 static unsigned long
  86 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
  87 {
  88         struct stack_frame *sf;
  89         struct pt_regs *regs;
  90
  91         while (1) {
  92                 sp = sp & PSW_ADDR_INSN;
  93                 if (sp < low || sp > high - sizeof(*sf))
  94                         return sp;
  95                 sf = (struct stack_frame *) sp;
  96                 printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
  97                 print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
  98                 /* Follow the backchain. */
  99                 while (1) {
 100                         low = sp;
 101                         sp = sf->back_chain & PSW_ADDR_INSN;
 102                         if (!sp)
 103                                 break;
 104                         if (sp <= low || sp > high - sizeof(*sf))
 105                                 return sp;
 106                         sf = (struct stack_frame *) sp;
 107                         printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
 108                         print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
 109                 }
 110                 /* Zero backchain detected, check for interrupt frame. */
 111                 sp = (unsigned long) (sf + 1);
 112                 if (sp <= low || sp > high - sizeof(*regs))
 113                         return sp;
 114                 regs = (struct pt_regs *) sp;
 115                 printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
 116                 print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
 117                 low = sp;
 118                 sp = regs->gprs[15];
 119         }
 120 }
 121
 122 static void show_trace(struct task_struct *task, unsigned long *stack)
 123 {
 124         register unsigned long __r15 asm ("15");
 125         unsigned long sp;
 126
 127         sp = (unsigned long) stack;
 128         if (!sp)
 129                 sp = task ? task->thread.ksp : __r15;
 130         printk("Call Trace:\n");
 131 #ifdef CONFIG_CHECK_STACK
 132         sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
 133                           S390_lowcore.panic_stack);
 134 #endif
 135         sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
 136                           S390_lowcore.async_stack);
 137         if (task)
 138                 __show_trace(sp, (unsigned long) task_stack_page(task),
 139                              (unsigned long) task_stack_page(task) + THREAD_SIZE);
 140         else
 141                 __show_trace(sp, S390_lowcore.thread_info,
 142                              S390_lowcore.thread_info + THREAD_SIZE);
 143         if (!task)
 144                 task = current;
 145         debug_show_held_locks(task);
 146 }
 147
 148 void show_stack(struct task_struct *task, unsigned long *sp)
 149 {
 150         register unsigned long * __r15 asm ("15");
 151         unsigned long *stack;
 152         int i;
 153
 154         if (!sp)
 155                 stack = task ? (unsigned long *) task->thread.ksp : __r15;
 156         else
 157                 stack = sp;
 158
 159         for (i = 0; i < kstack_depth_to_print; i++) {
 160                 if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
 161                         break;
 162                 if ((i * sizeof(long) % 32) == 0)
 163                         printk("%s       ", i == 0 ? "" : "\n");
 164                 printk(LONG, *stack++);
 165         }
 166         printk("\n");
 167         show_trace(task, sp);
 168 }
 169
 170 static void show_last_breaking_event(struct pt_regs *regs)
 171 {
 172 #ifdef CONFIG_64BIT
 173         printk("Last Breaking-Event-Address:\n");
 174         printk(" [<%016lx>] ", regs->args[0] & PSW_ADDR_INSN);
 175         print_symbol("%s\n", regs->args[0] & PSW_ADDR_INSN);
 176 #endif
 177 }
 178
 179 /*
 180  * The architecture-independent dump_stack generator
 181  */
 182 void dump_stack(void)
 183 {
 184         printk("CPU: %d %s %s %.*s\n",
 185                task_thread_info(current)->cpu, print_tainted(),
 186                init_utsname()->release,
 187                (int)strcspn(init_utsname()->version, " "),
 188                init_utsname()->version);
 189         printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
 190                current->comm, current->pid, current,
 191                (void *) current->thread.ksp);
 192         show_stack(NULL, NULL);
 193 }
 194 EXPORT_SYMBOL(dump_stack);
 195
 196 static inline int mask_bits(struct pt_regs *regs, unsigned long bits)
 197 {
 198         return (regs->psw.mask & bits) / ((~bits + 1) & bits);
 199 }
 200
 201 void show_registers(struct pt_regs *regs)
 202 {
 203         char *mode;
 204
 205         mode = user_mode(regs) ? "User" : "Krnl";
 206         printk("%s PSW : %p %p",
 207                mode, (void *) regs->psw.mask,
 208                (void *) regs->psw.addr);
 209         print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
 210         printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
 211                "P:%x AS:%x CC:%x PM:%x", mask_bits(regs, PSW_MASK_PER),
 212                mask_bits(regs, PSW_MASK_DAT), mask_bits(regs, PSW_MASK_IO),
 213                mask_bits(regs, PSW_MASK_EXT), mask_bits(regs, PSW_MASK_KEY),
 214                mask_bits(regs, PSW_MASK_MCHECK), mask_bits(regs, PSW_MASK_WAIT),
 215                mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC),
 216                mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM));
 217 #ifdef CONFIG_64BIT
 218         printk(" EA:%x", mask_bits(regs, PSW_MASK_EA | PSW_MASK_BA));
 219 #endif
 220         printk("\n%s GPRS: " FOURLONG, mode,
 221                regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
 222         printk("           " FOURLONG,
 223                regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
 224         printk("           " FOURLONG,
 225                regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
 226         printk("           " FOURLONG,
 227                regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
 228
 229         show_code(regs);
 230 }
 231
 232 void show_regs(struct pt_regs *regs)
 233 {
 234         print_modules();
 235         printk("CPU: %d %s %s %.*s\n",
 236                task_thread_info(current)->cpu, print_tainted(),
 237                init_utsname()->release,
 238                (int)strcspn(init_utsname()->version, " "),
 239                init_utsname()->version);
 240         printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
 241                current->comm, current->pid, current,
 242                (void *) current->thread.ksp);
 243         show_registers(regs);
 244         /* Show stack backtrace if pt_regs is from kernel mode */
 245         if (!user_mode(regs))
 246                 show_trace(NULL, (unsigned long *) regs->gprs[15]);
 247         show_last_breaking_event(regs);
 248 }
 249
 250 static DEFINE_SPINLOCK(die_lock);
 251
 252 void die(struct pt_regs *regs, const char *str)
 253 {
 254         static int die_counter;
 255
 256         oops_enter();
 257         lgr_info_log();
 258         debug_stop_all();
 259         console_verbose();
 260         spin_lock_irq(&die_lock);
 261         bust_spinlocks(1);
 262         printk("%s: %04x [#%d] ", str, regs->int_code & 0xffff, ++die_counter);
 263 #ifdef CONFIG_PREEMPT
 264         printk("PREEMPT ");
 265 #endif
 266 #ifdef CONFIG_SMP
 267         printk("SMP ");
 268 #endif
 269 #ifdef CONFIG_DEBUG_PAGEALLOC
 270         printk("DEBUG_PAGEALLOC");
 271 #endif
 272         printk("\n");
 273         notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);
 274         show_regs(regs);
 275         bust_spinlocks(0);
 276         add_taint(TAINT_DIE);
 277         spin_unlock_irq(&die_lock);
 278         if (in_interrupt())
 279                 panic("Fatal exception in interrupt");
 280         if (panic_on_oops)
 281                 panic("Fatal exception: panic_on_oops");
 282         oops_exit();
 283         do_exit(SIGSEGV);
 284 }
 285
 286 static inline void report_user_fault(struct pt_regs *regs, int signr)
 287 {
 288         if ((task_pid_nr(current) > 1) && !show_unhandled_signals)
 289                 return;
 290         if (!unhandled_signal(current, signr))
 291                 return;
 292         if (!printk_ratelimit())
 293                 return;
 294         printk("User process fault: interruption code 0x%X ", regs->int_code);
 295         print_vma_addr("in ", regs->psw.addr & PSW_ADDR_INSN);
 296         printk("\n");
 297         show_regs(regs);
 298 }
 299
 300 int is_valid_bugaddr(unsigned long addr)
 301 {
 302         return 1;
 303 }
 304
 305 static void __kprobes do_trap(struct pt_regs *regs,
 306                               int si_signo, int si_code, char *str)
 307 {
 308         siginfo_t info;
 309
 310         if (notify_die(DIE_TRAP, str, regs, 0,
 311                        regs->int_code, si_signo) == NOTIFY_STOP)
 312                 return;
 313
 314         if (user_mode(regs)) {
 315                 info.si_signo = si_signo;
 316                 info.si_errno = 0;
 317                 info.si_code = si_code;
 318                 info.si_addr = get_trap_ip(regs);
 319                 force_sig_info(si_signo, &info, current);
 320                 report_user_fault(regs, si_signo);
 321         } else {
 322                 const struct exception_table_entry *fixup;
 323                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
 324                 if (fixup)
 325                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
 326                 else {
 327                         enum bug_trap_type btt;
 328
 329                         btt = report_bug(regs->psw.addr & PSW_ADDR_INSN, regs);
 330                         if (btt == BUG_TRAP_TYPE_WARN)
 331                                 return;
 332                         die(regs, str);
 333                 }
 334         }
 335 }
 336
 337 void __kprobes do_per_trap(struct pt_regs *regs)
 338 {
 339         siginfo_t info;
 340
 341         if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
 342                 return;
 343         if (!current->ptrace)
 344                 return;
 345         info.si_signo = SIGTRAP;
 346         info.si_errno = 0;
 347         info.si_code = TRAP_HWBKPT;
 348         info.si_addr =
 349                 (void __force __user *) current->thread.per_event.address;
 350         force_sig_info(SIGTRAP, &info, current);
 351 }
 352
 353 static void default_trap_handler(struct pt_regs *regs)
 354 {
 355         if (user_mode(regs)) {
 356                 report_user_fault(regs, SIGSEGV);
 357                 do_exit(SIGSEGV);
 358         } else
 359                 die(regs, "Unknown program exception");
 360 }
 361
 362 #define DO_ERROR_INFO(name, signr, sicode, str) \
 363 static void name(struct pt_regs *regs) \
 364 { \
 365         do_trap(regs, signr, sicode, str); \
 366 }
 367
 368 DO_ERROR_INFO(addressing_exception, SIGILL, ILL_ILLADR,
 369               "addressing exception")
 370 DO_ERROR_INFO(execute_exception, SIGILL, ILL_ILLOPN,
 371               "execute exception")
 372 DO_ERROR_INFO(divide_exception, SIGFPE, FPE_INTDIV,
 373               "fixpoint divide exception")
 374 DO_ERROR_INFO(overflow_exception, SIGFPE, FPE_INTOVF,
 375               "fixpoint overflow exception")
 376 DO_ERROR_INFO(hfp_overflow_exception, SIGFPE, FPE_FLTOVF,
 377               "HFP overflow exception")
 378 DO_ERROR_INFO(hfp_underflow_exception, SIGFPE, FPE_FLTUND,
 379               "HFP underflow exception")
 380 DO_ERROR_INFO(hfp_significance_exception, SIGFPE, FPE_FLTRES,
 381               "HFP significance exception")
 382 DO_ERROR_INFO(hfp_divide_exception, SIGFPE, FPE_FLTDIV,
 383               "HFP divide exception")
 384 DO_ERROR_INFO(hfp_sqrt_exception, SIGFPE, FPE_FLTINV,
 385               "HFP square root exception")
 386 DO_ERROR_INFO(operand_exception, SIGILL, ILL_ILLOPN,
 387               "operand exception")
 388 DO_ERROR_INFO(privileged_op, SIGILL, ILL_PRVOPC,
 389               "privileged operation")
 390 DO_ERROR_INFO(special_op_exception, SIGILL, ILL_ILLOPN,
 391               "special operation exception")
 392 DO_ERROR_INFO(translation_exception, SIGILL, ILL_ILLOPN,
 393               "translation exception")
 394
 395 #ifdef CONFIG_64BIT
 396 DO_ERROR_INFO(transaction_exception, SIGILL, ILL_ILLOPN,
 397               "transaction constraint exception")
 398 #endif
 399
 400 static inline void do_fp_trap(struct pt_regs *regs, int fpc)
 401 {
 402         int si_code = 0;
 403         /* FPC[2] is Data Exception Code */
 404         if ((fpc & 0x00000300) == 0) {
 405                 /* bits 6 and 7 of DXC are 0 iff IEEE exception */
 406                 if (fpc & 0x8000) /* invalid fp operation */
 407                         si_code = FPE_FLTINV;
 408                 else if (fpc & 0x4000) /* div by 0 */
 409                         si_code = FPE_FLTDIV;
 410                 else if (fpc & 0x2000) /* overflow */
 411                         si_code = FPE_FLTOVF;
 412                 else if (fpc & 0x1000) /* underflow */
 413                         si_code = FPE_FLTUND;
 414                 else if (fpc & 0x0800) /* inexact */
 415                         si_code = FPE_FLTRES;
 416         }
 417         do_trap(regs, SIGFPE, si_code, "floating point exception");
 418 }
 419
 420 static void __kprobes illegal_op(struct pt_regs *regs)
 421 {
 422         siginfo_t info;
 423         __u8 opcode[6];
 424         __u16 __user *location;
 425         int signal = 0;
 426
 427         location = get_trap_ip(regs);
 428
 429         if (user_mode(regs)) {
 430                 if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
 431                         return;
 432                 if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
 433                         if (current->ptrace) {
 434                                 info.si_signo = SIGTRAP;
 435                                 info.si_errno = 0;
 436                                 info.si_code = TRAP_BRKPT;
 437                                 info.si_addr = location;
 438                                 force_sig_info(SIGTRAP, &info, current);
 439                         } else
 440                                 signal = SIGILL;
 441 #ifdef CONFIG_MATHEMU
 442                 } else if (opcode[0] == 0xb3) {
 443                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 444                                 return;
 445                         signal = math_emu_b3(opcode, regs);
 446                 } else if (opcode[0] == 0xed) {
 447                         if (get_user(*((__u32 *) (opcode+2)),
 448                                      (__u32 __user *)(location+1)))
 449                                 return;
 450                         signal = math_emu_ed(opcode, regs);
 451                 } else if (*((__u16 *) opcode) == 0xb299) {
 452                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 453                                 return;
 454                         signal = math_emu_srnm(opcode, regs);
 455                 } else if (*((__u16 *) opcode) == 0xb29c) {
 456                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 457                                 return;
 458                         signal = math_emu_stfpc(opcode, regs);
 459                 } else if (*((__u16 *) opcode) == 0xb29d) {
 460                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 461                                 return;
 462                         signal = math_emu_lfpc(opcode, regs);
 463 #endif
 464                 } else
 465                         signal = SIGILL;
 466         } else {
 467                 /*
 468                  * If we get an illegal op in kernel mode, send it through the
 469                  * kprobes notifier. If kprobes doesn't pick it up, SIGILL
 470                  */
 471                 if (notify_die(DIE_BPT, "bpt", regs, 0,
 472                                3, SIGTRAP) != NOTIFY_STOP)
 473                         signal = SIGILL;
 474         }
 475
 476 #ifdef CONFIG_MATHEMU
 477         if (signal == SIGFPE)
 478                 do_fp_trap(regs, current->thread.fp_regs.fpc);
 479         else if (signal == SIGSEGV)
 480                 do_trap(regs, signal, SEGV_MAPERR, "user address fault");
 481         else
 482 #endif
 483         if (signal)
 484                 do_trap(regs, signal, ILL_ILLOPC, "illegal operation");
 485 }
 486
 487
 488 #ifdef CONFIG_MATHEMU
 489 void specification_exception(struct pt_regs *regs)
 490 {
 491         __u8 opcode[6];
 492         __u16 __user *location = NULL;
 493         int signal = 0;
 494
 495         location = (__u16 __user *) get_trap_ip(regs);
 496
 497         if (user_mode(regs)) {
 498                 get_user(*((__u16 *) opcode), location);
 499                 switch (opcode[0]) {
 500                 case 0x28: /* LDR Rx,Ry   */
 501                         signal = math_emu_ldr(opcode);
 502                         break;
 503                 case 0x38: /* LER Rx,Ry   */
 504                         signal = math_emu_ler(opcode);
 505                         break;
 506                 case 0x60: /* STD R,D(X,B) */
 507                         get_user(*((__u16 *) (opcode+2)), location+1);
 508                         signal = math_emu_std(opcode, regs);
 509                         break;
 510                 case 0x68: /* LD R,D(X,B) */
 511                         get_user(*((__u16 *) (opcode+2)), location+1);
 512                         signal = math_emu_ld(opcode, regs);
 513                         break;
 514                 case 0x70: /* STE R,D(X,B) */
 515                         get_user(*((__u16 *) (opcode+2)), location+1);
 516                         signal = math_emu_ste(opcode, regs);
 517                         break;
 518                 case 0x78: /* LE R,D(X,B) */
 519                         get_user(*((__u16 *) (opcode+2)), location+1);
 520                         signal = math_emu_le(opcode, regs);
 521                         break;
 522                 default:
 523                         signal = SIGILL;
 524                         break;
 525                 }
 526         } else
 527                 signal = SIGILL;
 528
 529         if (signal == SIGFPE)
 530                 do_fp_trap(regs, current->thread.fp_regs.fpc);
 531         else if (signal)
 532                 do_trap(regs, signal, ILL_ILLOPN, "specification exception");
 533 }
 534 #else
 535 DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
 536               "specification exception");
 537 #endif
 538
 539 static void data_exception(struct pt_regs *regs)
 540 {
 541         __u16 __user *location;
 542         int signal = 0;
 543
 544         location = get_trap_ip(regs);
 545
 546         if (MACHINE_HAS_IEEE)
 547                 asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
 548
 549 #ifdef CONFIG_MATHEMU
 550         else if (user_mode(regs)) {
 551                 __u8 opcode[6];
 552                 get_user(*((__u16 *) opcode), location);
 553                 switch (opcode[0]) {
 554                 case 0x28: /* LDR Rx,Ry   */
 555                         signal = math_emu_ldr(opcode);
 556                         break;
 557                 case 0x38: /* LER Rx,Ry   */
 558                         signal = math_emu_ler(opcode);
 559                         break;
 560                 case 0x60: /* STD R,D(X,B) */
 561                         get_user(*((__u16 *) (opcode+2)), location+1);
 562                         signal = math_emu_std(opcode, regs);
 563                         break;
 564                 case 0x68: /* LD R,D(X,B) */
 565                         get_user(*((__u16 *) (opcode+2)), location+1);
 566                         signal = math_emu_ld(opcode, regs);
 567                         break;
 568                 case 0x70: /* STE R,D(X,B) */
 569                         get_user(*((__u16 *) (opcode+2)), location+1);
 570                         signal = math_emu_ste(opcode, regs);
 571                         break;
 572                 case 0x78: /* LE R,D(X,B) */
 573                         get_user(*((__u16 *) (opcode+2)), location+1);
 574                         signal = math_emu_le(opcode, regs);
 575                         break;
 576                 case 0xb3:
 577                         get_user(*((__u16 *) (opcode+2)), location+1);
 578                         signal = math_emu_b3(opcode, regs);
 579                         break;
 580                 case 0xed:
 581                         get_user(*((__u32 *) (opcode+2)),
 582                                  (__u32 __user *)(location+1));
 583                         signal = math_emu_ed(opcode, regs);
 584                         break;
 585                 case 0xb2:
 586                         if (opcode[1] == 0x99) {
 587                                 get_user(*((__u16 *) (opcode+2)), location+1);
 588                                 signal = math_emu_srnm(opcode, regs);
 589                         } else if (opcode[1] == 0x9c) {
 590                                 get_user(*((__u16 *) (opcode+2)), location+1);
 591                                 signal = math_emu_stfpc(opcode, regs);
 592                         } else if (opcode[1] == 0x9d) {
 593                                 get_user(*((__u16 *) (opcode+2)), location+1);
 594                                 signal = math_emu_lfpc(opcode, regs);
 595                         } else
 596                                 signal = SIGILL;
 597                         break;
 598                 default:
 599                         signal = SIGILL;
 600                         break;
 601                 }
 602         }
 603 #endif
 604         if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
 605                 signal = SIGFPE;
 606         else
 607                 signal = SIGILL;
 608         if (signal == SIGFPE)
 609                 do_fp_trap(regs, current->thread.fp_regs.fpc);
 610         else if (signal)
 611                 do_trap(regs, signal, ILL_ILLOPN, "data exception");
 612 }
 613
 614 static void space_switch_exception(struct pt_regs *regs)
 615 {
 616         /* Set user psw back to home space mode. */
 617         if (user_mode(regs))
 618                 regs->psw.mask |= PSW_ASC_HOME;
 619         /* Send SIGILL. */
 620         do_trap(regs, SIGILL, ILL_PRVOPC, "space switch event");
 621 }
 622
 623 void __kprobes kernel_stack_overflow(struct pt_regs * regs)
 624 {
 625         bust_spinlocks(1);
 626         printk("Kernel stack overflow.\n");
 627         show_regs(regs);
 628         bust_spinlocks(0);
 629         panic("Corrupt kernel stack, can't continue.");
 630 }
 631
 632 /* init is done in lowcore.S and head.S */
 633
 634 void __init trap_init(void)
 635 {
 636         int i;
 637
 638         for (i = 0; i < 128; i++)
 639           pgm_check_table[i] = &default_trap_handler;
 640         pgm_check_table[1] = &illegal_op;
 641         pgm_check_table[2] = &privileged_op;
 642         pgm_check_table[3] = &execute_exception;
 643         pgm_check_table[4] = &do_protection_exception;
 644         pgm_check_table[5] = &addressing_exception;
 645         pgm_check_table[6] = &specification_exception;
 646         pgm_check_table[7] = &data_exception;
 647         pgm_check_table[8] = &overflow_exception;
 648         pgm_check_table[9] = &divide_exception;
 649         pgm_check_table[0x0A] = &overflow_exception;
 650         pgm_check_table[0x0B] = &divide_exception;
 651         pgm_check_table[0x0C] = &hfp_overflow_exception;
 652         pgm_check_table[0x0D] = &hfp_underflow_exception;
 653         pgm_check_table[0x0E] = &hfp_significance_exception;
 654         pgm_check_table[0x0F] = &hfp_divide_exception;
 655         pgm_check_table[0x10] = &do_dat_exception;
 656         pgm_check_table[0x11] = &do_dat_exception;
 657         pgm_check_table[0x12] = &translation_exception;
 658         pgm_check_table[0x13] = &special_op_exception;
 659 #ifdef CONFIG_64BIT
 660         pgm_check_table[0x18] = &transaction_exception;
 661         pgm_check_table[0x38] = &do_asce_exception;
 662         pgm_check_table[0x39] = &do_dat_exception;
 663         pgm_check_table[0x3A] = &do_dat_exception;
 664         pgm_check_table[0x3B] = &do_dat_exception;
 665 #endif /* CONFIG_64BIT */
 666         pgm_check_table[0x15] = &operand_exception;
 667         pgm_check_table[0x1C] = &space_switch_exception;
 668         pgm_check_table[0x1D] = &hfp_sqrt_exception;
 669         /* Enable machine checks early. */
 670         local_mcck_enable();
 671 }