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   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/smp_lock.h>
  26 #include <linux/init.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/delay.h>
  29 #include <linux/module.h>
  30 #include <linux/kallsyms.h>
  31 #include <linux/reboot.h>
  32 #include <linux/kprobes.h>
  33 #include <linux/bug.h>
  34 #include <asm/system.h>
  35 #include <asm/uaccess.h>
  36 #include <asm/io.h>
  37 #include <asm/atomic.h>
  38 #include <asm/mathemu.h>
  39 #include <asm/cpcmd.h>
  40 #include <asm/s390_ext.h>
  41 #include <asm/lowcore.h>
  42 #include <asm/debug.h>
  43 #include <asm/kdebug.h>
  44
  45 /* Called from entry.S only */
  46 extern void handle_per_exception(struct pt_regs *regs);
  47
  48 typedef void pgm_check_handler_t(struct pt_regs *, long);
  49 pgm_check_handler_t *pgm_check_table[128];
  50
  51 #ifdef CONFIG_SYSCTL
  52 #ifdef CONFIG_PROCESS_DEBUG
  53 int sysctl_userprocess_debug = 1;
  54 #else
  55 int sysctl_userprocess_debug = 0;
  56 #endif
  57 #endif
  58
  59 extern pgm_check_handler_t do_protection_exception;
  60 extern pgm_check_handler_t do_dat_exception;
  61 extern pgm_check_handler_t do_monitor_call;
  62
  63 #define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
  64
  65 #ifndef CONFIG_64BIT
  66 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
  67 static int kstack_depth_to_print = 12;
  68 #else /* CONFIG_64BIT */
  69 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
  70 static int kstack_depth_to_print = 20;
  71 #endif /* CONFIG_64BIT */
  72
  73 ATOMIC_NOTIFIER_HEAD(s390die_chain);
  74
  75 int register_die_notifier(struct notifier_block *nb)
  76 {
  77         return atomic_notifier_chain_register(&s390die_chain, nb);
  78 }
  79 EXPORT_SYMBOL(register_die_notifier);
  80
  81 int unregister_die_notifier(struct notifier_block *nb)
  82 {
  83         return atomic_notifier_chain_unregister(&s390die_chain, nb);
  84 }
  85 EXPORT_SYMBOL(unregister_die_notifier);
  86
  87 /*
  88  * For show_trace we have tree different stack to consider:
  89  *   - the panic stack which is used if the kernel stack has overflown
  90  *   - the asynchronous interrupt stack (cpu related)
  91  *   - the synchronous kernel stack (process related)
  92  * The stack trace can start at any of the three stack and can potentially
  93  * touch all of them. The order is: panic stack, async stack, sync stack.
  94  */
  95 static unsigned long
  96 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
  97 {
  98         struct stack_frame *sf;
  99         struct pt_regs *regs;
 100
 101         while (1) {
 102                 sp = sp & PSW_ADDR_INSN;
 103                 if (sp < low || sp > high - sizeof(*sf))
 104                         return sp;
 105                 sf = (struct stack_frame *) sp;
 106                 printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
 107                 print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
 108                 /* Follow the backchain. */
 109                 while (1) {
 110                         low = sp;
 111                         sp = sf->back_chain & PSW_ADDR_INSN;
 112                         if (!sp)
 113                                 break;
 114                         if (sp <= low || sp > high - sizeof(*sf))
 115                                 return sp;
 116                         sf = (struct stack_frame *) sp;
 117                         printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
 118                         print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
 119                 }
 120                 /* Zero backchain detected, check for interrupt frame. */
 121                 sp = (unsigned long) (sf + 1);
 122                 if (sp <= low || sp > high - sizeof(*regs))
 123                         return sp;
 124                 regs = (struct pt_regs *) sp;
 125                 printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
 126                 print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
 127                 low = sp;
 128                 sp = regs->gprs[15];
 129         }
 130 }
 131
 132 void show_trace(struct task_struct *task, unsigned long *stack)
 133 {
 134         register unsigned long __r15 asm ("15");
 135         unsigned long sp;
 136
 137         sp = (unsigned long) stack;
 138         if (!sp)
 139                 sp = task ? task->thread.ksp : __r15;
 140         printk("Call Trace:\n");
 141 #ifdef CONFIG_CHECK_STACK
 142         sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
 143                           S390_lowcore.panic_stack);
 144 #endif
 145         sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
 146                           S390_lowcore.async_stack);
 147         if (task)
 148                 __show_trace(sp, (unsigned long) task_stack_page(task),
 149                              (unsigned long) task_stack_page(task) + THREAD_SIZE);
 150         else
 151                 __show_trace(sp, S390_lowcore.thread_info,
 152                              S390_lowcore.thread_info + THREAD_SIZE);
 153         printk("\n");
 154         if (!task)
 155                 task = current;
 156         debug_show_held_locks(task);
 157 }
 158
 159 void show_stack(struct task_struct *task, unsigned long *sp)
 160 {
 161         register unsigned long * __r15 asm ("15");
 162         unsigned long *stack;
 163         int i;
 164
 165         if (!sp)
 166                 stack = task ? (unsigned long *) task->thread.ksp : __r15;
 167         else
 168                 stack = sp;
 169
 170         for (i = 0; i < kstack_depth_to_print; i++) {
 171                 if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
 172                         break;
 173                 if (i && ((i * sizeof (long) % 32) == 0))
 174                         printk("\n       ");
 175                 printk("%p ", (void *)*stack++);
 176         }
 177         printk("\n");
 178         show_trace(task, sp);
 179 }
 180
 181 /*
 182  * The architecture-independent dump_stack generator
 183  */
 184 void dump_stack(void)
 185 {
 186         show_stack(NULL, NULL);
 187 }
 188
 189 EXPORT_SYMBOL(dump_stack);
 190
 191 static inline int mask_bits(struct pt_regs *regs, unsigned long bits)
 192 {
 193         return (regs->psw.mask & bits) / ((~bits + 1) & bits);
 194 }
 195
 196 void show_registers(struct pt_regs *regs)
 197 {
 198         char *mode;
 199
 200         mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
 201         printk("%s PSW : %p %p",
 202                mode, (void *) regs->psw.mask,
 203                (void *) regs->psw.addr);
 204         print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
 205         printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
 206                "P:%x AS:%x CC:%x PM:%x", mask_bits(regs, PSW_MASK_PER),
 207                mask_bits(regs, PSW_MASK_DAT), mask_bits(regs, PSW_MASK_IO),
 208                mask_bits(regs, PSW_MASK_EXT), mask_bits(regs, PSW_MASK_KEY),
 209                mask_bits(regs, PSW_MASK_MCHECK), mask_bits(regs, PSW_MASK_WAIT),
 210                mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC),
 211                mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM));
 212 #ifdef CONFIG_64BIT
 213         printk(" EA:%x", mask_bits(regs, PSW_BASE_BITS));
 214 #endif
 215         printk("\n%s GPRS: " FOURLONG, mode,
 216                regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
 217         printk("           " FOURLONG,
 218                regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
 219         printk("           " FOURLONG,
 220                regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
 221         printk("           " FOURLONG,
 222                regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
 223
 224         show_code(regs);
 225 }
 226
 227 /* This is called from fs/proc/array.c */
 228 char *task_show_regs(struct task_struct *task, char *buffer)
 229 {
 230         struct pt_regs *regs;
 231
 232         regs = task_pt_regs(task);
 233         buffer += sprintf(buffer, "task: %p, ksp: %p\n",
 234                        task, (void *)task->thread.ksp);
 235         buffer += sprintf(buffer, "User PSW : %p %p\n",
 236                        (void *) regs->psw.mask, (void *)regs->psw.addr);
 237
 238         buffer += sprintf(buffer, "User GPRS: " FOURLONG,
 239                           regs->gprs[0], regs->gprs[1],
 240                           regs->gprs[2], regs->gprs[3]);
 241         buffer += sprintf(buffer, "           " FOURLONG,
 242                           regs->gprs[4], regs->gprs[5],
 243                           regs->gprs[6], regs->gprs[7]);
 244         buffer += sprintf(buffer, "           " FOURLONG,
 245                           regs->gprs[8], regs->gprs[9],
 246                           regs->gprs[10], regs->gprs[11]);
 247         buffer += sprintf(buffer, "           " FOURLONG,
 248                           regs->gprs[12], regs->gprs[13],
 249                           regs->gprs[14], regs->gprs[15]);
 250         buffer += sprintf(buffer, "User ACRS: %08x %08x %08x %08x\n",
 251                           task->thread.acrs[0], task->thread.acrs[1],
 252                           task->thread.acrs[2], task->thread.acrs[3]);
 253         buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
 254                           task->thread.acrs[4], task->thread.acrs[5],
 255                           task->thread.acrs[6], task->thread.acrs[7]);
 256         buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
 257                           task->thread.acrs[8], task->thread.acrs[9],
 258                           task->thread.acrs[10], task->thread.acrs[11]);
 259         buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
 260                           task->thread.acrs[12], task->thread.acrs[13],
 261                           task->thread.acrs[14], task->thread.acrs[15]);
 262         return buffer;
 263 }
 264
 265 static DEFINE_SPINLOCK(die_lock);
 266
 267 void die(const char * str, struct pt_regs * regs, long err)
 268 {
 269         static int die_counter;
 270
 271         debug_stop_all();
 272         console_verbose();
 273         spin_lock_irq(&die_lock);
 274         bust_spinlocks(1);
 275         printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
 276         show_regs(regs);
 277         bust_spinlocks(0);
 278         spin_unlock_irq(&die_lock);
 279         if (in_interrupt())
 280                 panic("Fatal exception in interrupt");
 281         if (panic_on_oops)
 282                 panic("Fatal exception: panic_on_oops");
 283         do_exit(SIGSEGV);
 284 }
 285
 286 static void inline
 287 report_user_fault(long interruption_code, struct pt_regs *regs)
 288 {
 289 #if defined(CONFIG_SYSCTL)
 290         if (!sysctl_userprocess_debug)
 291                 return;
 292 #endif
 293 #if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG)
 294         printk("User process fault: interruption code 0x%lX\n",
 295                interruption_code);
 296         show_regs(regs);
 297 #endif
 298 }
 299
 300 int is_valid_bugaddr(unsigned long addr)
 301 {
 302         return 1;
 303 }
 304
 305 static void __kprobes inline do_trap(long interruption_code, int signr,
 306                                         char *str, struct pt_regs *regs,
 307                                         siginfo_t *info)
 308 {
 309         /*
 310          * We got all needed information from the lowcore and can
 311          * now safely switch on interrupts.
 312          */
 313         if (regs->psw.mask & PSW_MASK_PSTATE)
 314                 local_irq_enable();
 315
 316         if (notify_die(DIE_TRAP, str, regs, interruption_code,
 317                                 interruption_code, signr) == NOTIFY_STOP)
 318                 return;
 319
 320         if (regs->psw.mask & PSW_MASK_PSTATE) {
 321                 struct task_struct *tsk = current;
 322
 323                 tsk->thread.trap_no = interruption_code & 0xffff;
 324                 force_sig_info(signr, info, tsk);
 325                 report_user_fault(interruption_code, regs);
 326         } else {
 327                 const struct exception_table_entry *fixup;
 328                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
 329                 if (fixup)
 330                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
 331                 else {
 332                         enum bug_trap_type btt;
 333
 334                         btt = report_bug(regs->psw.addr & PSW_ADDR_INSN);
 335                         if (btt == BUG_TRAP_TYPE_WARN)
 336                                 return;
 337                         die(str, regs, interruption_code);
 338                 }
 339         }
 340 }
 341
 342 static inline void __user *get_check_address(struct pt_regs *regs)
 343 {
 344         return (void __user *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
 345 }
 346
 347 void __kprobes do_single_step(struct pt_regs *regs)
 348 {
 349         if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0,
 350                                         SIGTRAP) == NOTIFY_STOP){
 351                 return;
 352         }
 353         if ((current->ptrace & PT_PTRACED) != 0)
 354                 force_sig(SIGTRAP, current);
 355 }
 356
 357 static void default_trap_handler(struct pt_regs * regs, long interruption_code)
 358 {
 359         if (regs->psw.mask & PSW_MASK_PSTATE) {
 360                 local_irq_enable();
 361                 do_exit(SIGSEGV);
 362                 report_user_fault(interruption_code, regs);
 363         } else
 364                 die("Unknown program exception", regs, interruption_code);
 365 }
 366
 367 #define DO_ERROR_INFO(signr, str, name, sicode, siaddr) \
 368 static void name(struct pt_regs * regs, long interruption_code) \
 369 { \
 370         siginfo_t info; \
 371         info.si_signo = signr; \
 372         info.si_errno = 0; \
 373         info.si_code = sicode; \
 374         info.si_addr = siaddr; \
 375         do_trap(interruption_code, signr, str, regs, &info); \
 376 }
 377
 378 DO_ERROR_INFO(SIGILL, "addressing exception", addressing_exception,
 379               ILL_ILLADR, get_check_address(regs))
 380 DO_ERROR_INFO(SIGILL,  "execute exception", execute_exception,
 381               ILL_ILLOPN, get_check_address(regs))
 382 DO_ERROR_INFO(SIGFPE,  "fixpoint divide exception", divide_exception,
 383               FPE_INTDIV, get_check_address(regs))
 384 DO_ERROR_INFO(SIGFPE,  "fixpoint overflow exception", overflow_exception,
 385               FPE_INTOVF, get_check_address(regs))
 386 DO_ERROR_INFO(SIGFPE,  "HFP overflow exception", hfp_overflow_exception,
 387               FPE_FLTOVF, get_check_address(regs))
 388 DO_ERROR_INFO(SIGFPE,  "HFP underflow exception", hfp_underflow_exception,
 389               FPE_FLTUND, get_check_address(regs))
 390 DO_ERROR_INFO(SIGFPE,  "HFP significance exception", hfp_significance_exception,
 391               FPE_FLTRES, get_check_address(regs))
 392 DO_ERROR_INFO(SIGFPE,  "HFP divide exception", hfp_divide_exception,
 393               FPE_FLTDIV, get_check_address(regs))
 394 DO_ERROR_INFO(SIGFPE,  "HFP square root exception", hfp_sqrt_exception,
 395               FPE_FLTINV, get_check_address(regs))
 396 DO_ERROR_INFO(SIGILL,  "operand exception", operand_exception,
 397               ILL_ILLOPN, get_check_address(regs))
 398 DO_ERROR_INFO(SIGILL,  "privileged operation", privileged_op,
 399               ILL_PRVOPC, get_check_address(regs))
 400 DO_ERROR_INFO(SIGILL,  "special operation exception", special_op_exception,
 401               ILL_ILLOPN, get_check_address(regs))
 402 DO_ERROR_INFO(SIGILL,  "translation exception", translation_exception,
 403               ILL_ILLOPN, get_check_address(regs))
 404
 405 static inline void
 406 do_fp_trap(struct pt_regs *regs, void __user *location,
 407            int fpc, long interruption_code)
 408 {
 409         siginfo_t si;
 410
 411         si.si_signo = SIGFPE;
 412         si.si_errno = 0;
 413         si.si_addr = location;
 414         si.si_code = 0;
 415         /* FPC[2] is Data Exception Code */
 416         if ((fpc & 0x00000300) == 0) {
 417                 /* bits 6 and 7 of DXC are 0 iff IEEE exception */
 418                 if (fpc & 0x8000) /* invalid fp operation */
 419                         si.si_code = FPE_FLTINV;
 420                 else if (fpc & 0x4000) /* div by 0 */
 421                         si.si_code = FPE_FLTDIV;
 422                 else if (fpc & 0x2000) /* overflow */
 423                         si.si_code = FPE_FLTOVF;
 424                 else if (fpc & 0x1000) /* underflow */
 425                         si.si_code = FPE_FLTUND;
 426                 else if (fpc & 0x0800) /* inexact */
 427                         si.si_code = FPE_FLTRES;
 428         }
 429         current->thread.ieee_instruction_pointer = (addr_t) location;
 430         do_trap(interruption_code, SIGFPE,
 431                 "floating point exception", regs, &si);
 432 }
 433
 434 static void illegal_op(struct pt_regs * regs, long interruption_code)
 435 {
 436         siginfo_t info;
 437         __u8 opcode[6];
 438         __u16 __user *location;
 439         int signal = 0;
 440
 441         location = get_check_address(regs);
 442
 443         /*
 444          * We got all needed information from the lowcore and can
 445          * now safely switch on interrupts.
 446          */
 447         if (regs->psw.mask & PSW_MASK_PSTATE)
 448                 local_irq_enable();
 449
 450         if (regs->psw.mask & PSW_MASK_PSTATE) {
 451                 if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
 452                         return;
 453                 if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
 454                         if (current->ptrace & PT_PTRACED)
 455                                 force_sig(SIGTRAP, current);
 456                         else
 457                                 signal = SIGILL;
 458 #ifdef CONFIG_MATHEMU
 459                 } else if (opcode[0] == 0xb3) {
 460                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 461                                 return;
 462                         signal = math_emu_b3(opcode, regs);
 463                 } else if (opcode[0] == 0xed) {
 464                         if (get_user(*((__u32 *) (opcode+2)),
 465                                      (__u32 __user *)(location+1)))
 466                                 return;
 467                         signal = math_emu_ed(opcode, regs);
 468                 } else if (*((__u16 *) opcode) == 0xb299) {
 469                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 470                                 return;
 471                         signal = math_emu_srnm(opcode, regs);
 472                 } else if (*((__u16 *) opcode) == 0xb29c) {
 473                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 474                                 return;
 475                         signal = math_emu_stfpc(opcode, regs);
 476                 } else if (*((__u16 *) opcode) == 0xb29d) {
 477                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 478                                 return;
 479                         signal = math_emu_lfpc(opcode, regs);
 480 #endif
 481                 } else
 482                         signal = SIGILL;
 483         } else {
 484                 /*
 485                  * If we get an illegal op in kernel mode, send it through the
 486                  * kprobes notifier. If kprobes doesn't pick it up, SIGILL
 487                  */
 488                 if (notify_die(DIE_BPT, "bpt", regs, interruption_code,
 489                                3, SIGTRAP) != NOTIFY_STOP)
 490                         signal = SIGILL;
 491         }
 492
 493 #ifdef CONFIG_MATHEMU
 494         if (signal == SIGFPE)
 495                 do_fp_trap(regs, location,
 496                            current->thread.fp_regs.fpc, interruption_code);
 497         else if (signal == SIGSEGV) {
 498                 info.si_signo = signal;
 499                 info.si_errno = 0;
 500                 info.si_code = SEGV_MAPERR;
 501                 info.si_addr = (void __user *) location;
 502                 do_trap(interruption_code, signal,
 503                         "user address fault", regs, &info);
 504         } else
 505 #endif
 506         if (signal) {
 507                 info.si_signo = signal;
 508                 info.si_errno = 0;
 509                 info.si_code = ILL_ILLOPC;
 510                 info.si_addr = (void __user *) location;
 511                 do_trap(interruption_code, signal,
 512                         "illegal operation", regs, &info);
 513         }
 514 }
 515
 516
 517 #ifdef CONFIG_MATHEMU
 518 asmlinkage void
 519 specification_exception(struct pt_regs * regs, long interruption_code)
 520 {
 521         __u8 opcode[6];
 522         __u16 __user *location = NULL;
 523         int signal = 0;
 524
 525         location = (__u16 __user *) get_check_address(regs);
 526
 527         /*
 528          * We got all needed information from the lowcore and can
 529          * now safely switch on interrupts.
 530          */
 531         if (regs->psw.mask & PSW_MASK_PSTATE)
 532                 local_irq_enable();
 533
 534         if (regs->psw.mask & PSW_MASK_PSTATE) {
 535                 get_user(*((__u16 *) opcode), location);
 536                 switch (opcode[0]) {
 537                 case 0x28: /* LDR Rx,Ry   */
 538                         signal = math_emu_ldr(opcode);
 539                         break;
 540                 case 0x38: /* LER Rx,Ry   */
 541                         signal = math_emu_ler(opcode);
 542                         break;
 543                 case 0x60: /* STD R,D(X,B) */
 544                         get_user(*((__u16 *) (opcode+2)), location+1);
 545                         signal = math_emu_std(opcode, regs);
 546                         break;
 547                 case 0x68: /* LD R,D(X,B) */
 548                         get_user(*((__u16 *) (opcode+2)), location+1);
 549                         signal = math_emu_ld(opcode, regs);
 550                         break;
 551                 case 0x70: /* STE R,D(X,B) */
 552                         get_user(*((__u16 *) (opcode+2)), location+1);
 553                         signal = math_emu_ste(opcode, regs);
 554                         break;
 555                 case 0x78: /* LE R,D(X,B) */
 556                         get_user(*((__u16 *) (opcode+2)), location+1);
 557                         signal = math_emu_le(opcode, regs);
 558                         break;
 559                 default:
 560                         signal = SIGILL;
 561                         break;
 562                 }
 563         } else
 564                 signal = SIGILL;
 565
 566         if (signal == SIGFPE)
 567                 do_fp_trap(regs, location,
 568                            current->thread.fp_regs.fpc, interruption_code);
 569         else if (signal) {
 570                 siginfo_t info;
 571                 info.si_signo = signal;
 572                 info.si_errno = 0;
 573                 info.si_code = ILL_ILLOPN;
 574                 info.si_addr = location;
 575                 do_trap(interruption_code, signal,
 576                         "specification exception", regs, &info);
 577         }
 578 }
 579 #else
 580 DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
 581               ILL_ILLOPN, get_check_address(regs));
 582 #endif
 583
 584 static void data_exception(struct pt_regs * regs, long interruption_code)
 585 {
 586         __u16 __user *location;
 587         int signal = 0;
 588
 589         location = get_check_address(regs);
 590
 591         /*
 592          * We got all needed information from the lowcore and can
 593          * now safely switch on interrupts.
 594          */
 595         if (regs->psw.mask & PSW_MASK_PSTATE)
 596                 local_irq_enable();
 597
 598         if (MACHINE_HAS_IEEE)
 599                 asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
 600
 601 #ifdef CONFIG_MATHEMU
 602         else if (regs->psw.mask & PSW_MASK_PSTATE) {
 603                 __u8 opcode[6];
 604                 get_user(*((__u16 *) opcode), location);
 605                 switch (opcode[0]) {
 606                 case 0x28: /* LDR Rx,Ry   */
 607                         signal = math_emu_ldr(opcode);
 608                         break;
 609                 case 0x38: /* LER Rx,Ry   */
 610                         signal = math_emu_ler(opcode);
 611                         break;
 612                 case 0x60: /* STD R,D(X,B) */
 613                         get_user(*((__u16 *) (opcode+2)), location+1);
 614                         signal = math_emu_std(opcode, regs);
 615                         break;
 616                 case 0x68: /* LD R,D(X,B) */
 617                         get_user(*((__u16 *) (opcode+2)), location+1);
 618                         signal = math_emu_ld(opcode, regs);
 619                         break;
 620                 case 0x70: /* STE R,D(X,B) */
 621                         get_user(*((__u16 *) (opcode+2)), location+1);
 622                         signal = math_emu_ste(opcode, regs);
 623                         break;
 624                 case 0x78: /* LE R,D(X,B) */
 625                         get_user(*((__u16 *) (opcode+2)), location+1);
 626                         signal = math_emu_le(opcode, regs);
 627                         break;
 628                 case 0xb3:
 629                         get_user(*((__u16 *) (opcode+2)), location+1);
 630                         signal = math_emu_b3(opcode, regs);
 631                         break;
 632                 case 0xed:
 633                         get_user(*((__u32 *) (opcode+2)),
 634                                  (__u32 __user *)(location+1));
 635                         signal = math_emu_ed(opcode, regs);
 636                         break;
 637                 case 0xb2:
 638                         if (opcode[1] == 0x99) {
 639                                 get_user(*((__u16 *) (opcode+2)), location+1);
 640                                 signal = math_emu_srnm(opcode, regs);
 641                         } else if (opcode[1] == 0x9c) {
 642                                 get_user(*((__u16 *) (opcode+2)), location+1);
 643                                 signal = math_emu_stfpc(opcode, regs);
 644                         } else if (opcode[1] == 0x9d) {
 645                                 get_user(*((__u16 *) (opcode+2)), location+1);
 646                                 signal = math_emu_lfpc(opcode, regs);
 647                         } else
 648                                 signal = SIGILL;
 649                         break;
 650                 default:
 651                         signal = SIGILL;
 652                         break;
 653                 }
 654         }
 655 #endif
 656         if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
 657                 signal = SIGFPE;
 658         else
 659                 signal = SIGILL;
 660         if (signal == SIGFPE)
 661                 do_fp_trap(regs, location,
 662                            current->thread.fp_regs.fpc, interruption_code);
 663         else if (signal) {
 664                 siginfo_t info;
 665                 info.si_signo = signal;
 666                 info.si_errno = 0;
 667                 info.si_code = ILL_ILLOPN;
 668                 info.si_addr = location;
 669                 do_trap(interruption_code, signal,
 670                         "data exception", regs, &info);
 671         }
 672 }
 673
 674 static void space_switch_exception(struct pt_regs * regs, long int_code)
 675 {
 676         siginfo_t info;
 677
 678         /* Set user psw back to home space mode. */
 679         if (regs->psw.mask & PSW_MASK_PSTATE)
 680                 regs->psw.mask |= PSW_ASC_HOME;
 681         /* Send SIGILL. */
 682         info.si_signo = SIGILL;
 683         info.si_errno = 0;
 684         info.si_code = ILL_PRVOPC;
 685         info.si_addr = get_check_address(regs);
 686         do_trap(int_code, SIGILL, "space switch event", regs, &info);
 687 }
 688
 689 asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
 690 {
 691         bust_spinlocks(1);
 692         printk("Kernel stack overflow.\n");
 693         show_regs(regs);
 694         bust_spinlocks(0);
 695         panic("Corrupt kernel stack, can't continue.");
 696 }
 697
 698 /* init is done in lowcore.S and head.S */
 699
 700 void __init trap_init(void)
 701 {
 702         int i;
 703
 704         for (i = 0; i < 128; i++)
 705           pgm_check_table[i] = &default_trap_handler;
 706         pgm_check_table[1] = &illegal_op;
 707         pgm_check_table[2] = &privileged_op;
 708         pgm_check_table[3] = &execute_exception;
 709         pgm_check_table[4] = &do_protection_exception;
 710         pgm_check_table[5] = &addressing_exception;
 711         pgm_check_table[6] = &specification_exception;
 712         pgm_check_table[7] = &data_exception;
 713         pgm_check_table[8] = &overflow_exception;
 714         pgm_check_table[9] = &divide_exception;
 715         pgm_check_table[0x0A] = &overflow_exception;
 716         pgm_check_table[0x0B] = &divide_exception;
 717         pgm_check_table[0x0C] = &hfp_overflow_exception;
 718         pgm_check_table[0x0D] = &hfp_underflow_exception;
 719         pgm_check_table[0x0E] = &hfp_significance_exception;
 720         pgm_check_table[0x0F] = &hfp_divide_exception;
 721         pgm_check_table[0x10] = &do_dat_exception;
 722         pgm_check_table[0x11] = &do_dat_exception;
 723         pgm_check_table[0x12] = &translation_exception;
 724         pgm_check_table[0x13] = &special_op_exception;
 725 #ifdef CONFIG_64BIT
 726         pgm_check_table[0x38] = &do_dat_exception;
 727         pgm_check_table[0x39] = &do_dat_exception;
 728         pgm_check_table[0x3A] = &do_dat_exception;
 729         pgm_check_table[0x3B] = &do_dat_exception;
 730 #endif /* CONFIG_64BIT */
 731         pgm_check_table[0x15] = &operand_exception;
 732         pgm_check_table[0x1C] = &space_switch_exception;
 733         pgm_check_table[0x1D] = &hfp_sqrt_exception;
 734         pgm_check_table[0x40] = &do_monitor_call;
 735         pfault_irq_init();
 736 }