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/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
  33 #include <asm/system.h>
  34 #include <asm/uaccess.h>
  35 #include <asm/io.h>
  36 #include <asm/atomic.h>
  37 #include <asm/mathemu.h>
  38 #include <asm/cpcmd.h>
  39 #include <asm/s390_ext.h>
  40 #include <asm/lowcore.h>
  41 #include <asm/debug.h>
  42
  43 /* Called from entry.S only */
  44 extern void handle_per_exception(struct pt_regs *regs);
  45
  46 typedef void pgm_check_handler_t(struct pt_regs *, long);
  47 pgm_check_handler_t *pgm_check_table[128];
  48
  49 #ifdef CONFIG_SYSCTL
  50 #ifdef CONFIG_PROCESS_DEBUG
  51 int sysctl_userprocess_debug = 1;
  52 #else
  53 int sysctl_userprocess_debug = 0;
  54 #endif
  55 #endif
  56
  57 extern pgm_check_handler_t do_protection_exception;
  58 extern pgm_check_handler_t do_dat_exception;
  59 #ifdef CONFIG_PFAULT
  60 extern int pfault_init(void);
  61 extern void pfault_fini(void);
  62 extern void pfault_interrupt(struct pt_regs *regs, __u16 error_code);
  63 static ext_int_info_t ext_int_pfault;
  64 #endif
  65 extern pgm_check_handler_t do_monitor_call;
  66
  67 #define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
  68
  69 #ifndef CONFIG_64BIT
  70 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
  71 static int kstack_depth_to_print = 12;
  72 #else /* CONFIG_64BIT */
  73 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
  74 static int kstack_depth_to_print = 20;
  75 #endif /* CONFIG_64BIT */
  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 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         printk("\n");
 144 }
 145
 146 void show_stack(struct task_struct *task, unsigned long *sp)
 147 {
 148         register unsigned long * __r15 asm ("15");
 149         unsigned long *stack;
 150         int i;
 151
 152         if (!sp)
 153                 stack = task ? (unsigned long *) task->thread.ksp : __r15;
 154         else
 155                 stack = sp;
 156
 157         for (i = 0; i < kstack_depth_to_print; i++) {
 158                 if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
 159                         break;
 160                 if (i && ((i * sizeof (long) % 32) == 0))
 161                         printk("\n       ");
 162                 printk("%p ", (void *)*stack++);
 163         }
 164         printk("\n");
 165         show_trace(task, sp);
 166 }
 167
 168 /*
 169  * The architecture-independent dump_stack generator
 170  */
 171 void dump_stack(void)
 172 {
 173         show_stack(0, 0);
 174 }
 175
 176 EXPORT_SYMBOL(dump_stack);
 177
 178 void show_registers(struct pt_regs *regs)
 179 {
 180         mm_segment_t old_fs;
 181         char *mode;
 182         int i;
 183
 184         mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
 185         printk("%s PSW : %p %p",
 186                mode, (void *) regs->psw.mask,
 187                (void *) regs->psw.addr);
 188         print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
 189         printk("%s GPRS: " FOURLONG, mode,
 190                regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
 191         printk("           " FOURLONG,
 192                regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
 193         printk("           " FOURLONG,
 194                regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
 195         printk("           " FOURLONG,
 196                regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
 197
 198 #if 0
 199         /* FIXME: this isn't needed any more but it changes the ksymoops
 200          * input. To remove or not to remove ... */
 201         save_access_regs(regs->acrs);
 202         printk("%s ACRS: %08x %08x %08x %08x\n", mode,
 203                regs->acrs[0], regs->acrs[1], regs->acrs[2], regs->acrs[3]);
 204         printk("           %08x %08x %08x %08x\n",
 205                regs->acrs[4], regs->acrs[5], regs->acrs[6], regs->acrs[7]);
 206         printk("           %08x %08x %08x %08x\n",
 207                regs->acrs[8], regs->acrs[9], regs->acrs[10], regs->acrs[11]);
 208         printk("           %08x %08x %08x %08x\n",
 209                regs->acrs[12], regs->acrs[13], regs->acrs[14], regs->acrs[15]);
 210 #endif
 211
 212         /*
 213          * Print the first 20 byte of the instruction stream at the
 214          * time of the fault.
 215          */
 216         old_fs = get_fs();
 217         if (regs->psw.mask & PSW_MASK_PSTATE)
 218                 set_fs(USER_DS);
 219         else
 220                 set_fs(KERNEL_DS);
 221         printk("%s Code: ", mode);
 222         for (i = 0; i < 20; i++) {
 223                 unsigned char c;
 224                 if (__get_user(c, (char __user *)(regs->psw.addr + i))) {
 225                         printk(" Bad PSW.");
 226                         break;
 227                 }
 228                 printk("%02x ", c);
 229         }
 230         set_fs(old_fs);
 231
 232         printk("\n");
 233 }
 234
 235 /* This is called from fs/proc/array.c */
 236 char *task_show_regs(struct task_struct *task, char *buffer)
 237 {
 238         struct pt_regs *regs;
 239
 240         regs = task_pt_regs(task);
 241         buffer += sprintf(buffer, "task: %p, ksp: %p\n",
 242                        task, (void *)task->thread.ksp);
 243         buffer += sprintf(buffer, "User PSW : %p %p\n",
 244                        (void *) regs->psw.mask, (void *)regs->psw.addr);
 245
 246         buffer += sprintf(buffer, "User GPRS: " FOURLONG,
 247                           regs->gprs[0], regs->gprs[1],
 248                           regs->gprs[2], regs->gprs[3]);
 249         buffer += sprintf(buffer, "           " FOURLONG,
 250                           regs->gprs[4], regs->gprs[5],
 251                           regs->gprs[6], regs->gprs[7]);
 252         buffer += sprintf(buffer, "           " FOURLONG,
 253                           regs->gprs[8], regs->gprs[9],
 254                           regs->gprs[10], regs->gprs[11]);
 255         buffer += sprintf(buffer, "           " FOURLONG,
 256                           regs->gprs[12], regs->gprs[13],
 257                           regs->gprs[14], regs->gprs[15]);
 258         buffer += sprintf(buffer, "User ACRS: %08x %08x %08x %08x\n",
 259                           task->thread.acrs[0], task->thread.acrs[1],
 260                           task->thread.acrs[2], task->thread.acrs[3]);
 261         buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
 262                           task->thread.acrs[4], task->thread.acrs[5],
 263                           task->thread.acrs[6], task->thread.acrs[7]);
 264         buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
 265                           task->thread.acrs[8], task->thread.acrs[9],
 266                           task->thread.acrs[10], task->thread.acrs[11]);
 267         buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
 268                           task->thread.acrs[12], task->thread.acrs[13],
 269                           task->thread.acrs[14], task->thread.acrs[15]);
 270         return buffer;
 271 }
 272
 273 DEFINE_SPINLOCK(die_lock);
 274
 275 void die(const char * str, struct pt_regs * regs, long err)
 276 {
 277         static int die_counter;
 278
 279         debug_stop_all();
 280         console_verbose();
 281         spin_lock_irq(&die_lock);
 282         bust_spinlocks(1);
 283         printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
 284         show_regs(regs);
 285         bust_spinlocks(0);
 286         spin_unlock_irq(&die_lock);
 287         if (in_interrupt())
 288                 panic("Fatal exception in interrupt");
 289         if (panic_on_oops)
 290                 panic("Fatal exception: panic_on_oops");
 291         do_exit(SIGSEGV);
 292 }
 293
 294 static void inline
 295 report_user_fault(long interruption_code, struct pt_regs *regs)
 296 {
 297 #if defined(CONFIG_SYSCTL)
 298         if (!sysctl_userprocess_debug)
 299                 return;
 300 #endif
 301 #if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG)
 302         printk("User process fault: interruption code 0x%lX\n",
 303                interruption_code);
 304         show_regs(regs);
 305 #endif
 306 }
 307
 308 static void inline do_trap(long interruption_code, int signr, char *str,
 309                            struct pt_regs *regs, siginfo_t *info)
 310 {
 311         /*
 312          * We got all needed information from the lowcore and can
 313          * now safely switch on interrupts.
 314          */
 315         if (regs->psw.mask & PSW_MASK_PSTATE)
 316                 local_irq_enable();
 317
 318         if (regs->psw.mask & PSW_MASK_PSTATE) {
 319                 struct task_struct *tsk = current;
 320
 321                 tsk->thread.trap_no = interruption_code & 0xffff;
 322                 force_sig_info(signr, info, tsk);
 323                 report_user_fault(interruption_code, regs);
 324         } else {
 325                 const struct exception_table_entry *fixup;
 326                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
 327                 if (fixup)
 328                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
 329                 else
 330                         die(str, regs, interruption_code);
 331         }
 332 }
 333
 334 static inline void *get_check_address(struct pt_regs *regs)
 335 {
 336         return (void *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
 337 }
 338
 339 void do_single_step(struct pt_regs *regs)
 340 {
 341         if ((current->ptrace & PT_PTRACED) != 0)
 342                 force_sig(SIGTRAP, current);
 343 }
 344
 345 asmlinkage void
 346 default_trap_handler(struct pt_regs * regs, long interruption_code)
 347 {
 348         if (regs->psw.mask & PSW_MASK_PSTATE) {
 349                 local_irq_enable();
 350                 do_exit(SIGSEGV);
 351                 report_user_fault(interruption_code, regs);
 352         } else
 353                 die("Unknown program exception", regs, interruption_code);
 354 }
 355
 356 #define DO_ERROR_INFO(signr, str, name, sicode, siaddr) \
 357 asmlinkage void name(struct pt_regs * regs, long interruption_code) \
 358 { \
 359         siginfo_t info; \
 360         info.si_signo = signr; \
 361         info.si_errno = 0; \
 362         info.si_code = sicode; \
 363         info.si_addr = (void *)siaddr; \
 364         do_trap(interruption_code, signr, str, regs, &info); \
 365 }
 366
 367 DO_ERROR_INFO(SIGILL, "addressing exception", addressing_exception,
 368               ILL_ILLADR, get_check_address(regs))
 369 DO_ERROR_INFO(SIGILL,  "execute exception", execute_exception,
 370               ILL_ILLOPN, get_check_address(regs))
 371 DO_ERROR_INFO(SIGFPE,  "fixpoint divide exception", divide_exception,
 372               FPE_INTDIV, get_check_address(regs))
 373 DO_ERROR_INFO(SIGFPE,  "fixpoint overflow exception", overflow_exception,
 374               FPE_INTOVF, get_check_address(regs))
 375 DO_ERROR_INFO(SIGFPE,  "HFP overflow exception", hfp_overflow_exception,
 376               FPE_FLTOVF, get_check_address(regs))
 377 DO_ERROR_INFO(SIGFPE,  "HFP underflow exception", hfp_underflow_exception,
 378               FPE_FLTUND, get_check_address(regs))
 379 DO_ERROR_INFO(SIGFPE,  "HFP significance exception", hfp_significance_exception,
 380               FPE_FLTRES, get_check_address(regs))
 381 DO_ERROR_INFO(SIGFPE,  "HFP divide exception", hfp_divide_exception,
 382               FPE_FLTDIV, get_check_address(regs))
 383 DO_ERROR_INFO(SIGFPE,  "HFP square root exception", hfp_sqrt_exception,
 384               FPE_FLTINV, get_check_address(regs))
 385 DO_ERROR_INFO(SIGILL,  "operand exception", operand_exception,
 386               ILL_ILLOPN, get_check_address(regs))
 387 DO_ERROR_INFO(SIGILL,  "privileged operation", privileged_op,
 388               ILL_PRVOPC, get_check_address(regs))
 389 DO_ERROR_INFO(SIGILL,  "special operation exception", special_op_exception,
 390               ILL_ILLOPN, get_check_address(regs))
 391 DO_ERROR_INFO(SIGILL,  "translation exception", translation_exception,
 392               ILL_ILLOPN, get_check_address(regs))
 393
 394 static inline void
 395 do_fp_trap(struct pt_regs *regs, void *location,
 396            int fpc, long interruption_code)
 397 {
 398         siginfo_t si;
 399
 400         si.si_signo = SIGFPE;
 401         si.si_errno = 0;
 402         si.si_addr = location;
 403         si.si_code = 0;
 404         /* FPC[2] is Data Exception Code */
 405         if ((fpc & 0x00000300) == 0) {
 406                 /* bits 6 and 7 of DXC are 0 iff IEEE exception */
 407                 if (fpc & 0x8000) /* invalid fp operation */
 408                         si.si_code = FPE_FLTINV;
 409                 else if (fpc & 0x4000) /* div by 0 */
 410                         si.si_code = FPE_FLTDIV;
 411                 else if (fpc & 0x2000) /* overflow */
 412                         si.si_code = FPE_FLTOVF;
 413                 else if (fpc & 0x1000) /* underflow */
 414                         si.si_code = FPE_FLTUND;
 415                 else if (fpc & 0x0800) /* inexact */
 416                         si.si_code = FPE_FLTRES;
 417         }
 418         current->thread.ieee_instruction_pointer = (addr_t) location;
 419         do_trap(interruption_code, SIGFPE,
 420                 "floating point exception", regs, &si);
 421 }
 422
 423 asmlinkage void illegal_op(struct pt_regs * regs, long interruption_code)
 424 {
 425         siginfo_t info;
 426         __u8 opcode[6];
 427         __u16 *location;
 428         int signal = 0;
 429
 430         location = (__u16 *) get_check_address(regs);
 431
 432         /*
 433          * We got all needed information from the lowcore and can
 434          * now safely switch on interrupts.
 435          */
 436         if (regs->psw.mask & PSW_MASK_PSTATE)
 437                 local_irq_enable();
 438
 439         if (regs->psw.mask & PSW_MASK_PSTATE) {
 440                 get_user(*((__u16 *) opcode), (__u16 __user *) location);
 441                 if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
 442                         if (current->ptrace & PT_PTRACED)
 443                                 force_sig(SIGTRAP, current);
 444                         else
 445                                 signal = SIGILL;
 446 #ifdef CONFIG_MATHEMU
 447                 } else if (opcode[0] == 0xb3) {
 448                         get_user(*((__u16 *) (opcode+2)), location+1);
 449                         signal = math_emu_b3(opcode, regs);
 450                 } else if (opcode[0] == 0xed) {
 451                         get_user(*((__u32 *) (opcode+2)),
 452                                  (__u32 *)(location+1));
 453                         signal = math_emu_ed(opcode, regs);
 454                 } else if (*((__u16 *) opcode) == 0xb299) {
 455                         get_user(*((__u16 *) (opcode+2)), location+1);
 456                         signal = math_emu_srnm(opcode, regs);
 457                 } else if (*((__u16 *) opcode) == 0xb29c) {
 458                         get_user(*((__u16 *) (opcode+2)), location+1);
 459                         signal = math_emu_stfpc(opcode, regs);
 460                 } else if (*((__u16 *) opcode) == 0xb29d) {
 461                         get_user(*((__u16 *) (opcode+2)), location+1);
 462                         signal = math_emu_lfpc(opcode, regs);
 463 #endif
 464                 } else
 465                         signal = SIGILL;
 466         } else
 467                 signal = SIGILL;
 468
 469 #ifdef CONFIG_MATHEMU
 470         if (signal == SIGFPE)
 471                 do_fp_trap(regs, location,
 472                            current->thread.fp_regs.fpc, interruption_code);
 473         else if (signal == SIGSEGV) {
 474                 info.si_signo = signal;
 475                 info.si_errno = 0;
 476                 info.si_code = SEGV_MAPERR;
 477                 info.si_addr = (void *) location;
 478                 do_trap(interruption_code, signal,
 479                         "user address fault", regs, &info);
 480         } else
 481 #endif
 482         if (signal) {
 483                 info.si_signo = signal;
 484                 info.si_errno = 0;
 485                 info.si_code = ILL_ILLOPC;
 486                 info.si_addr = (void __user *) location;
 487                 do_trap(interruption_code, signal,
 488                         "illegal operation", regs, &info);
 489         }
 490 }
 491
 492
 493 #ifdef CONFIG_MATHEMU
 494 asmlinkage void
 495 specification_exception(struct pt_regs * regs, long interruption_code)
 496 {
 497         __u8 opcode[6];
 498         __u16 *location = NULL;
 499         int signal = 0;
 500
 501         location = (__u16 *) get_check_address(regs);
 502
 503         /*
 504          * We got all needed information from the lowcore and can
 505          * now safely switch on interrupts.
 506          */
 507         if (regs->psw.mask & PSW_MASK_PSTATE)
 508                 local_irq_enable();
 509
 510         if (regs->psw.mask & PSW_MASK_PSTATE) {
 511                 get_user(*((__u16 *) opcode), location);
 512                 switch (opcode[0]) {
 513                 case 0x28: /* LDR Rx,Ry   */
 514                         signal = math_emu_ldr(opcode);
 515                         break;
 516                 case 0x38: /* LER Rx,Ry   */
 517                         signal = math_emu_ler(opcode);
 518                         break;
 519                 case 0x60: /* STD R,D(X,B) */
 520                         get_user(*((__u16 *) (opcode+2)), location+1);
 521                         signal = math_emu_std(opcode, regs);
 522                         break;
 523                 case 0x68: /* LD R,D(X,B) */
 524                         get_user(*((__u16 *) (opcode+2)), location+1);
 525                         signal = math_emu_ld(opcode, regs);
 526                         break;
 527                 case 0x70: /* STE R,D(X,B) */
 528                         get_user(*((__u16 *) (opcode+2)), location+1);
 529                         signal = math_emu_ste(opcode, regs);
 530                         break;
 531                 case 0x78: /* LE R,D(X,B) */
 532                         get_user(*((__u16 *) (opcode+2)), location+1);
 533                         signal = math_emu_le(opcode, regs);
 534                         break;
 535                 default:
 536                         signal = SIGILL;
 537                         break;
 538                 }
 539         } else
 540                 signal = SIGILL;
 541
 542         if (signal == SIGFPE)
 543                 do_fp_trap(regs, location,
 544                            current->thread.fp_regs.fpc, interruption_code);
 545         else if (signal) {
 546                 siginfo_t info;
 547                 info.si_signo = signal;
 548                 info.si_errno = 0;
 549                 info.si_code = ILL_ILLOPN;
 550                 info.si_addr = location;
 551                 do_trap(interruption_code, signal,
 552                         "specification exception", regs, &info);
 553         }
 554 }
 555 #else
 556 DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
 557               ILL_ILLOPN, get_check_address(regs));
 558 #endif
 559
 560 asmlinkage void data_exception(struct pt_regs * regs, long interruption_code)
 561 {
 562         __u16 *location;
 563         int signal = 0;
 564
 565         location = (__u16 *) get_check_address(regs);
 566
 567         /*
 568          * We got all needed information from the lowcore and can
 569          * now safely switch on interrupts.
 570          */
 571         if (regs->psw.mask & PSW_MASK_PSTATE)
 572                 local_irq_enable();
 573
 574         if (MACHINE_HAS_IEEE)
 575                 __asm__ volatile ("stfpc %0\n\t"
 576                                   : "=m" (current->thread.fp_regs.fpc));
 577
 578 #ifdef CONFIG_MATHEMU
 579         else if (regs->psw.mask & PSW_MASK_PSTATE) {
 580                 __u8 opcode[6];
 581                 get_user(*((__u16 *) opcode), location);
 582                 switch (opcode[0]) {
 583                 case 0x28: /* LDR Rx,Ry   */
 584                         signal = math_emu_ldr(opcode);
 585                         break;
 586                 case 0x38: /* LER Rx,Ry   */
 587                         signal = math_emu_ler(opcode);
 588                         break;
 589                 case 0x60: /* STD R,D(X,B) */
 590                         get_user(*((__u16 *) (opcode+2)), location+1);
 591                         signal = math_emu_std(opcode, regs);
 592                         break;
 593                 case 0x68: /* LD R,D(X,B) */
 594                         get_user(*((__u16 *) (opcode+2)), location+1);
 595                         signal = math_emu_ld(opcode, regs);
 596                         break;
 597                 case 0x70: /* STE R,D(X,B) */
 598                         get_user(*((__u16 *) (opcode+2)), location+1);
 599                         signal = math_emu_ste(opcode, regs);
 600                         break;
 601                 case 0x78: /* LE R,D(X,B) */
 602                         get_user(*((__u16 *) (opcode+2)), location+1);
 603                         signal = math_emu_le(opcode, regs);
 604                         break;
 605                 case 0xb3:
 606                         get_user(*((__u16 *) (opcode+2)), location+1);
 607                         signal = math_emu_b3(opcode, regs);
 608                         break;
 609                 case 0xed:
 610                         get_user(*((__u32 *) (opcode+2)),
 611                                  (__u32 *)(location+1));
 612                         signal = math_emu_ed(opcode, regs);
 613                         break;
 614                 case 0xb2:
 615                         if (opcode[1] == 0x99) {
 616                                 get_user(*((__u16 *) (opcode+2)), location+1);
 617                                 signal = math_emu_srnm(opcode, regs);
 618                         } else if (opcode[1] == 0x9c) {
 619                                 get_user(*((__u16 *) (opcode+2)), location+1);
 620                                 signal = math_emu_stfpc(opcode, regs);
 621                         } else if (opcode[1] == 0x9d) {
 622                                 get_user(*((__u16 *) (opcode+2)), location+1);
 623                                 signal = math_emu_lfpc(opcode, regs);
 624                         } else
 625                                 signal = SIGILL;
 626                         break;
 627                 default:
 628                         signal = SIGILL;
 629                         break;
 630                 }
 631         }
 632 #endif
 633         if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
 634                 signal = SIGFPE;
 635         else
 636                 signal = SIGILL;
 637         if (signal == SIGFPE)
 638                 do_fp_trap(regs, location,
 639                            current->thread.fp_regs.fpc, interruption_code);
 640         else if (signal) {
 641                 siginfo_t info;
 642                 info.si_signo = signal;
 643                 info.si_errno = 0;
 644                 info.si_code = ILL_ILLOPN;
 645                 info.si_addr = location;
 646                 do_trap(interruption_code, signal,
 647                         "data exception", regs, &info);
 648         }
 649 }
 650
 651 asmlinkage void space_switch_exception(struct pt_regs * regs, long int_code)
 652 {
 653         siginfo_t info;
 654
 655         /* Set user psw back to home space mode. */
 656         if (regs->psw.mask & PSW_MASK_PSTATE)
 657                 regs->psw.mask |= PSW_ASC_HOME;
 658         /* Send SIGILL. */
 659         info.si_signo = SIGILL;
 660         info.si_errno = 0;
 661         info.si_code = ILL_PRVOPC;
 662         info.si_addr = get_check_address(regs);
 663         do_trap(int_code, SIGILL, "space switch event", regs, &info);
 664 }
 665
 666 asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
 667 {
 668         bust_spinlocks(1);
 669         printk("Kernel stack overflow.\n");
 670         show_regs(regs);
 671         bust_spinlocks(0);
 672         panic("Corrupt kernel stack, can't continue.");
 673 }
 674
 675 /* init is done in lowcore.S and head.S */
 676
 677 void __init trap_init(void)
 678 {
 679         int i;
 680
 681         for (i = 0; i < 128; i++)
 682           pgm_check_table[i] = &default_trap_handler;
 683         pgm_check_table[1] = &illegal_op;
 684         pgm_check_table[2] = &privileged_op;
 685         pgm_check_table[3] = &execute_exception;
 686         pgm_check_table[4] = &do_protection_exception;
 687         pgm_check_table[5] = &addressing_exception;
 688         pgm_check_table[6] = &specification_exception;
 689         pgm_check_table[7] = &data_exception;
 690         pgm_check_table[8] = &overflow_exception;
 691         pgm_check_table[9] = &divide_exception;
 692         pgm_check_table[0x0A] = &overflow_exception;
 693         pgm_check_table[0x0B] = &divide_exception;
 694         pgm_check_table[0x0C] = &hfp_overflow_exception;
 695         pgm_check_table[0x0D] = &hfp_underflow_exception;
 696         pgm_check_table[0x0E] = &hfp_significance_exception;
 697         pgm_check_table[0x0F] = &hfp_divide_exception;
 698         pgm_check_table[0x10] = &do_dat_exception;
 699         pgm_check_table[0x11] = &do_dat_exception;
 700         pgm_check_table[0x12] = &translation_exception;
 701         pgm_check_table[0x13] = &special_op_exception;
 702 #ifdef CONFIG_64BIT
 703         pgm_check_table[0x38] = &do_dat_exception;
 704         pgm_check_table[0x39] = &do_dat_exception;
 705         pgm_check_table[0x3A] = &do_dat_exception;
 706         pgm_check_table[0x3B] = &do_dat_exception;
 707 #endif /* CONFIG_64BIT */
 708         pgm_check_table[0x15] = &operand_exception;
 709         pgm_check_table[0x1C] = &space_switch_exception;
 710         pgm_check_table[0x1D] = &hfp_sqrt_exception;
 711         pgm_check_table[0x40] = &do_monitor_call;
 712
 713         if (MACHINE_IS_VM) {
 714 #ifdef CONFIG_PFAULT
 715                 /*
 716                  * Try to get pfault pseudo page faults going.
 717                  */
 718                 if (register_early_external_interrupt(0x2603, pfault_interrupt,
 719                                                       &ext_int_pfault) != 0)
 720                         panic("Couldn't request external interrupt 0x2603");
 721
 722                 if (pfault_init() == 0)
 723                         return;
 724
 725                 /* Tough luck, no pfault. */
 726                 unregister_early_external_interrupt(0x2603, pfault_interrupt,
 727                                                     &ext_int_pfault);
 728 #endif
 729         }
 730 }