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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/config.h>
  18 #include <linux/sched.h>
  19 #include <linux/kernel.h>
  20 #include <linux/string.h>
  21 #include <linux/errno.h>
  22 #include <linux/ptrace.h>
  23 #include <linux/timer.h>
  24 #include <linux/mm.h>
  25 #include <linux/smp.h>
  26 #include <linux/smp_lock.h>
  27 #include <linux/init.h>
  28 #include <linux/interrupt.h>
  29 #include <linux/delay.h>
  30 #include <linux/module.h>
  31 #include <linux/kallsyms.h>
  32 #include <linux/reboot.h>
  33
  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
  44 /* Called from entry.S only */
  45 extern void handle_per_exception(struct pt_regs *regs);
  46
  47 typedef void pgm_check_handler_t(struct pt_regs *, long);
  48 pgm_check_handler_t *pgm_check_table[128];
  49
  50 #ifdef CONFIG_SYSCTL
  51 #ifdef CONFIG_PROCESS_DEBUG
  52 int sysctl_userprocess_debug = 1;
  53 #else
  54 int sysctl_userprocess_debug = 0;
  55 #endif
  56 #endif
  57
  58 extern pgm_check_handler_t do_protection_exception;
  59 extern pgm_check_handler_t do_dat_exception;
  60 #ifdef CONFIG_PFAULT
  61 extern int pfault_init(void);
  62 extern void pfault_fini(void);
  63 extern void pfault_interrupt(struct pt_regs *regs, __u16 error_code);
  64 static ext_int_info_t ext_int_pfault;
  65 #endif
  66 extern pgm_check_handler_t do_monitor_call;
  67
  68 #define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
  69
  70 #ifndef CONFIG_64BIT
  71 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
  72 static int kstack_depth_to_print = 12;
  73 #else /* CONFIG_64BIT */
  74 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
  75 static int kstack_depth_to_print = 20;
  76 #endif /* CONFIG_64BIT */
  77
  78 /*
  79  * For show_trace we have tree different stack to consider:
  80  *   - the panic stack which is used if the kernel stack has overflown
  81  *   - the asynchronous interrupt stack (cpu related)
  82  *   - the synchronous kernel stack (process related)
  83  * The stack trace can start at any of the three stack and can potentially
  84  * touch all of them. The order is: panic stack, async stack, sync stack.
  85  */
  86 static unsigned long
  87 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
  88 {
  89         struct stack_frame *sf;
  90         struct pt_regs *regs;
  91
  92         while (1) {
  93                 sp = sp & PSW_ADDR_INSN;
  94                 if (sp < low || sp > high - sizeof(*sf))
  95                         return sp;
  96                 sf = (struct stack_frame *) sp;
  97                 printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
  98                 print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
  99                 /* Follow the backchain. */
 100                 while (1) {
 101                         low = sp;
 102                         sp = sf->back_chain & PSW_ADDR_INSN;
 103                         if (!sp)
 104                                 break;
 105                         if (sp <= low || sp > high - sizeof(*sf))
 106                                 return sp;
 107                         sf = (struct stack_frame *) sp;
 108                         printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
 109                         print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
 110                 }
 111                 /* Zero backchain detected, check for interrupt frame. */
 112                 sp = (unsigned long) (sf + 1);
 113                 if (sp <= low || sp > high - sizeof(*regs))
 114                         return sp;
 115                 regs = (struct pt_regs *) sp;
 116                 printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
 117                 print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
 118                 low = sp;
 119                 sp = regs->gprs[15];
 120         }
 121 }
 122
 123 void show_trace(struct task_struct *task, unsigned long * stack)
 124 {
 125         register unsigned long __r15 asm ("15");
 126         unsigned long sp;
 127
 128         sp = (unsigned long) stack;
 129         if (!sp)
 130                 sp = task ? task->thread.ksp : __r15;
 131         printk("Call Trace:\n");
 132 #ifdef CONFIG_CHECK_STACK
 133         sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
 134                           S390_lowcore.panic_stack);
 135 #endif
 136         sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
 137                           S390_lowcore.async_stack);
 138         if (task)
 139                 __show_trace(sp, (unsigned long) task_stack_page(task),
 140                              (unsigned long) task_stack_page(task) + THREAD_SIZE);
 141         else
 142                 __show_trace(sp, S390_lowcore.thread_info,
 143                              S390_lowcore.thread_info + THREAD_SIZE);
 144         printk("\n");
 145 }
 146
 147 void show_stack(struct task_struct *task, unsigned long *sp)
 148 {
 149         register unsigned long * __r15 asm ("15");
 150         unsigned long *stack;
 151         int i;
 152
 153         if (!sp)
 154                 stack = task ? (unsigned long *) task->thread.ksp : __r15;
 155         else
 156                 stack = sp;
 157
 158         for (i = 0; i < kstack_depth_to_print; i++) {
 159                 if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
 160                         break;
 161                 if (i && ((i * sizeof (long) % 32) == 0))
 162                         printk("\n       ");
 163                 printk("%p ", (void *)*stack++);
 164         }
 165         printk("\n");
 166         show_trace(task, sp);
 167 }
 168
 169 /*
 170  * The architecture-independent dump_stack generator
 171  */
 172 void dump_stack(void)
 173 {
 174         show_stack(0, 0);
 175 }
 176
 177 EXPORT_SYMBOL(dump_stack);
 178
 179 void show_registers(struct pt_regs *regs)
 180 {
 181         mm_segment_t old_fs;
 182         char *mode;
 183         int i;
 184
 185         mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
 186         printk("%s PSW : %p %p",
 187                mode, (void *) regs->psw.mask,
 188                (void *) regs->psw.addr);
 189         print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
 190         printk("%s GPRS: " FOURLONG, mode,
 191                regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
 192         printk("           " FOURLONG,
 193                regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
 194         printk("           " FOURLONG,
 195                regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
 196         printk("           " FOURLONG,
 197                regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
 198
 199 #if 0
 200         /* FIXME: this isn't needed any more but it changes the ksymoops
 201          * input. To remove or not to remove ... */
 202         save_access_regs(regs->acrs);
 203         printk("%s ACRS: %08x %08x %08x %08x\n", mode,
 204                regs->acrs[0], regs->acrs[1], regs->acrs[2], regs->acrs[3]);
 205         printk("           %08x %08x %08x %08x\n",
 206                regs->acrs[4], regs->acrs[5], regs->acrs[6], regs->acrs[7]);
 207         printk("           %08x %08x %08x %08x\n",
 208                regs->acrs[8], regs->acrs[9], regs->acrs[10], regs->acrs[11]);
 209         printk("           %08x %08x %08x %08x\n",
 210                regs->acrs[12], regs->acrs[13], regs->acrs[14], regs->acrs[15]);
 211 #endif
 212
 213         /*
 214          * Print the first 20 byte of the instruction stream at the
 215          * time of the fault.
 216          */
 217         old_fs = get_fs();
 218         if (regs->psw.mask & PSW_MASK_PSTATE)
 219                 set_fs(USER_DS);
 220         else
 221                 set_fs(KERNEL_DS);
 222         printk("%s Code: ", mode);
 223         for (i = 0; i < 20; i++) {
 224                 unsigned char c;
 225                 if (__get_user(c, (char __user *)(regs->psw.addr + i))) {
 226                         printk(" Bad PSW.");
 227                         break;
 228                 }
 229                 printk("%02x ", c);
 230         }
 231         set_fs(old_fs);
 232
 233         printk("\n");
 234 }
 235
 236 /* This is called from fs/proc/array.c */
 237 char *task_show_regs(struct task_struct *task, char *buffer)
 238 {
 239         struct pt_regs *regs;
 240
 241         regs = task_pt_regs(task);
 242         buffer += sprintf(buffer, "task: %p, ksp: %p\n",
 243                        task, (void *)task->thread.ksp);
 244         buffer += sprintf(buffer, "User PSW : %p %p\n",
 245                        (void *) regs->psw.mask, (void *)regs->psw.addr);
 246
 247         buffer += sprintf(buffer, "User GPRS: " FOURLONG,
 248                           regs->gprs[0], regs->gprs[1],
 249                           regs->gprs[2], regs->gprs[3]);
 250         buffer += sprintf(buffer, "           " FOURLONG,
 251                           regs->gprs[4], regs->gprs[5],
 252                           regs->gprs[6], regs->gprs[7]);
 253         buffer += sprintf(buffer, "           " FOURLONG,
 254                           regs->gprs[8], regs->gprs[9],
 255                           regs->gprs[10], regs->gprs[11]);
 256         buffer += sprintf(buffer, "           " FOURLONG,
 257                           regs->gprs[12], regs->gprs[13],
 258                           regs->gprs[14], regs->gprs[15]);
 259         buffer += sprintf(buffer, "User ACRS: %08x %08x %08x %08x\n",
 260                           task->thread.acrs[0], task->thread.acrs[1],
 261                           task->thread.acrs[2], task->thread.acrs[3]);
 262         buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
 263                           task->thread.acrs[4], task->thread.acrs[5],
 264                           task->thread.acrs[6], task->thread.acrs[7]);
 265         buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
 266                           task->thread.acrs[8], task->thread.acrs[9],
 267                           task->thread.acrs[10], task->thread.acrs[11]);
 268         buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
 269                           task->thread.acrs[12], task->thread.acrs[13],
 270                           task->thread.acrs[14], task->thread.acrs[15]);
 271         return buffer;
 272 }
 273
 274 DEFINE_SPINLOCK(die_lock);
 275
 276 void die(const char * str, struct pt_regs * regs, long err)
 277 {
 278         static int die_counter;
 279
 280         debug_stop_all();
 281         console_verbose();
 282         spin_lock_irq(&die_lock);
 283         bust_spinlocks(1);
 284         printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
 285         show_regs(regs);
 286         bust_spinlocks(0);
 287         spin_unlock_irq(&die_lock);
 288         if (in_interrupt())
 289                 panic("Fatal exception in interrupt");
 290         if (panic_on_oops)
 291                 panic("Fatal exception: panic_on_oops");
 292         do_exit(SIGSEGV);
 293 }
 294
 295 static void inline
 296 report_user_fault(long interruption_code, struct pt_regs *regs)
 297 {
 298 #if defined(CONFIG_SYSCTL)
 299         if (!sysctl_userprocess_debug)
 300                 return;
 301 #endif
 302 #if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG)
 303         printk("User process fault: interruption code 0x%lX\n",
 304                interruption_code);
 305         show_regs(regs);
 306 #endif
 307 }
 308
 309 static void inline do_trap(long interruption_code, int signr, char *str,
 310                            struct pt_regs *regs, siginfo_t *info)
 311 {
 312         /*
 313          * We got all needed information from the lowcore and can
 314          * now safely switch on interrupts.
 315          */
 316         if (regs->psw.mask & PSW_MASK_PSTATE)
 317                 local_irq_enable();
 318
 319         if (regs->psw.mask & PSW_MASK_PSTATE) {
 320                 struct task_struct *tsk = current;
 321
 322                 tsk->thread.trap_no = interruption_code & 0xffff;
 323                 force_sig_info(signr, info, tsk);
 324                 report_user_fault(interruption_code, regs);
 325         } else {
 326                 const struct exception_table_entry *fixup;
 327                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
 328                 if (fixup)
 329                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
 330                 else
 331                         die(str, regs, interruption_code);
 332         }
 333 }
 334
 335 static inline void *get_check_address(struct pt_regs *regs)
 336 {
 337         return (void *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
 338 }
 339
 340 void do_single_step(struct pt_regs *regs)
 341 {
 342         if ((current->ptrace & PT_PTRACED) != 0)
 343                 force_sig(SIGTRAP, current);
 344 }
 345
 346 asmlinkage void
 347 default_trap_handler(struct pt_regs * regs, long interruption_code)
 348 {
 349         if (regs->psw.mask & PSW_MASK_PSTATE) {
 350                 local_irq_enable();
 351                 do_exit(SIGSEGV);
 352                 report_user_fault(interruption_code, regs);
 353         } else
 354                 die("Unknown program exception", regs, interruption_code);
 355 }
 356
 357 #define DO_ERROR_INFO(signr, str, name, sicode, siaddr) \
 358 asmlinkage void name(struct pt_regs * regs, long interruption_code) \
 359 { \
 360         siginfo_t info; \
 361         info.si_signo = signr; \
 362         info.si_errno = 0; \
 363         info.si_code = sicode; \
 364         info.si_addr = (void *)siaddr; \
 365         do_trap(interruption_code, signr, str, regs, &info); \
 366 }
 367
 368 DO_ERROR_INFO(SIGILL, "addressing exception", addressing_exception,
 369               ILL_ILLADR, get_check_address(regs))
 370 DO_ERROR_INFO(SIGILL,  "execute exception", execute_exception,
 371               ILL_ILLOPN, get_check_address(regs))
 372 DO_ERROR_INFO(SIGFPE,  "fixpoint divide exception", divide_exception,
 373               FPE_INTDIV, get_check_address(regs))
 374 DO_ERROR_INFO(SIGFPE,  "fixpoint overflow exception", overflow_exception,
 375               FPE_INTOVF, get_check_address(regs))
 376 DO_ERROR_INFO(SIGFPE,  "HFP overflow exception", hfp_overflow_exception,
 377               FPE_FLTOVF, get_check_address(regs))
 378 DO_ERROR_INFO(SIGFPE,  "HFP underflow exception", hfp_underflow_exception,
 379               FPE_FLTUND, get_check_address(regs))
 380 DO_ERROR_INFO(SIGFPE,  "HFP significance exception", hfp_significance_exception,
 381               FPE_FLTRES, get_check_address(regs))
 382 DO_ERROR_INFO(SIGFPE,  "HFP divide exception", hfp_divide_exception,
 383               FPE_FLTDIV, get_check_address(regs))
 384 DO_ERROR_INFO(SIGFPE,  "HFP square root exception", hfp_sqrt_exception,
 385               FPE_FLTINV, get_check_address(regs))
 386 DO_ERROR_INFO(SIGILL,  "operand exception", operand_exception,
 387               ILL_ILLOPN, get_check_address(regs))
 388 DO_ERROR_INFO(SIGILL,  "privileged operation", privileged_op,
 389               ILL_PRVOPC, get_check_address(regs))
 390 DO_ERROR_INFO(SIGILL,  "special operation exception", special_op_exception,
 391               ILL_ILLOPN, get_check_address(regs))
 392 DO_ERROR_INFO(SIGILL,  "translation exception", translation_exception,
 393               ILL_ILLOPN, get_check_address(regs))
 394
 395 static inline void
 396 do_fp_trap(struct pt_regs *regs, void *location,
 397            int fpc, long interruption_code)
 398 {
 399         siginfo_t si;
 400
 401         si.si_signo = SIGFPE;
 402         si.si_errno = 0;
 403         si.si_addr = location;
 404         si.si_code = 0;
 405         /* FPC[2] is Data Exception Code */
 406         if ((fpc & 0x00000300) == 0) {
 407                 /* bits 6 and 7 of DXC are 0 iff IEEE exception */
 408                 if (fpc & 0x8000) /* invalid fp operation */
 409                         si.si_code = FPE_FLTINV;
 410                 else if (fpc & 0x4000) /* div by 0 */
 411                         si.si_code = FPE_FLTDIV;
 412                 else if (fpc & 0x2000) /* overflow */
 413                         si.si_code = FPE_FLTOVF;
 414                 else if (fpc & 0x1000) /* underflow */
 415                         si.si_code = FPE_FLTUND;
 416                 else if (fpc & 0x0800) /* inexact */
 417                         si.si_code = FPE_FLTRES;
 418         }
 419         current->thread.ieee_instruction_pointer = (addr_t) location;
 420         do_trap(interruption_code, SIGFPE,
 421                 "floating point exception", regs, &si);
 422 }
 423
 424 asmlinkage void illegal_op(struct pt_regs * regs, long interruption_code)
 425 {
 426         siginfo_t info;
 427         __u8 opcode[6];
 428         __u16 *location;
 429         int signal = 0;
 430
 431         location = (__u16 *) get_check_address(regs);
 432
 433         /*
 434          * We got all needed information from the lowcore and can
 435          * now safely switch on interrupts.
 436          */
 437         if (regs->psw.mask & PSW_MASK_PSTATE)
 438                 local_irq_enable();
 439
 440         if (regs->psw.mask & PSW_MASK_PSTATE) {
 441                 get_user(*((__u16 *) opcode), (__u16 __user *) location);
 442                 if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
 443                         if (current->ptrace & PT_PTRACED)
 444                                 force_sig(SIGTRAP, current);
 445                         else
 446                                 signal = SIGILL;
 447 #ifdef CONFIG_MATHEMU
 448                 } else if (opcode[0] == 0xb3) {
 449                         get_user(*((__u16 *) (opcode+2)), location+1);
 450                         signal = math_emu_b3(opcode, regs);
 451                 } else if (opcode[0] == 0xed) {
 452                         get_user(*((__u32 *) (opcode+2)),
 453                                  (__u32 *)(location+1));
 454                         signal = math_emu_ed(opcode, regs);
 455                 } else if (*((__u16 *) opcode) == 0xb299) {
 456                         get_user(*((__u16 *) (opcode+2)), location+1);
 457                         signal = math_emu_srnm(opcode, regs);
 458                 } else if (*((__u16 *) opcode) == 0xb29c) {
 459                         get_user(*((__u16 *) (opcode+2)), location+1);
 460                         signal = math_emu_stfpc(opcode, regs);
 461                 } else if (*((__u16 *) opcode) == 0xb29d) {
 462                         get_user(*((__u16 *) (opcode+2)), location+1);
 463                         signal = math_emu_lfpc(opcode, regs);
 464 #endif
 465                 } else
 466                         signal = SIGILL;
 467         } else
 468                 signal = SIGILL;
 469
 470 #ifdef CONFIG_MATHEMU
 471         if (signal == SIGFPE)
 472                 do_fp_trap(regs, location,
 473                            current->thread.fp_regs.fpc, interruption_code);
 474         else if (signal == SIGSEGV) {
 475                 info.si_signo = signal;
 476                 info.si_errno = 0;
 477                 info.si_code = SEGV_MAPERR;
 478                 info.si_addr = (void *) location;
 479                 do_trap(interruption_code, signal,
 480                         "user address fault", regs, &info);
 481         } else
 482 #endif
 483         if (signal) {
 484                 info.si_signo = signal;
 485                 info.si_errno = 0;
 486                 info.si_code = ILL_ILLOPC;
 487                 info.si_addr = (void __user *) location;
 488                 do_trap(interruption_code, signal,
 489                         "illegal operation", regs, &info);
 490         }
 491 }
 492
 493
 494 #ifdef CONFIG_MATHEMU
 495 asmlinkage void
 496 specification_exception(struct pt_regs * regs, long interruption_code)
 497 {
 498         __u8 opcode[6];
 499         __u16 *location = NULL;
 500         int signal = 0;
 501
 502         location = (__u16 *) get_check_address(regs);
 503
 504         /*
 505          * We got all needed information from the lowcore and can
 506          * now safely switch on interrupts.
 507          */
 508         if (regs->psw.mask & PSW_MASK_PSTATE)
 509                 local_irq_enable();
 510
 511         if (regs->psw.mask & PSW_MASK_PSTATE) {
 512                 get_user(*((__u16 *) opcode), location);
 513                 switch (opcode[0]) {
 514                 case 0x28: /* LDR Rx,Ry   */
 515                         signal = math_emu_ldr(opcode);
 516                         break;
 517                 case 0x38: /* LER Rx,Ry   */
 518                         signal = math_emu_ler(opcode);
 519                         break;
 520                 case 0x60: /* STD R,D(X,B) */
 521                         get_user(*((__u16 *) (opcode+2)), location+1);
 522                         signal = math_emu_std(opcode, regs);
 523                         break;
 524                 case 0x68: /* LD R,D(X,B) */
 525                         get_user(*((__u16 *) (opcode+2)), location+1);
 526                         signal = math_emu_ld(opcode, regs);
 527                         break;
 528                 case 0x70: /* STE R,D(X,B) */
 529                         get_user(*((__u16 *) (opcode+2)), location+1);
 530                         signal = math_emu_ste(opcode, regs);
 531                         break;
 532                 case 0x78: /* LE R,D(X,B) */
 533                         get_user(*((__u16 *) (opcode+2)), location+1);
 534                         signal = math_emu_le(opcode, regs);
 535                         break;
 536                 default:
 537                         signal = SIGILL;
 538                         break;
 539                 }
 540         } else
 541                 signal = SIGILL;
 542
 543         if (signal == SIGFPE)
 544                 do_fp_trap(regs, location,
 545                            current->thread.fp_regs.fpc, interruption_code);
 546         else if (signal) {
 547                 siginfo_t info;
 548                 info.si_signo = signal;
 549                 info.si_errno = 0;
 550                 info.si_code = ILL_ILLOPN;
 551                 info.si_addr = location;
 552                 do_trap(interruption_code, signal,
 553                         "specification exception", regs, &info);
 554         }
 555 }
 556 #else
 557 DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
 558               ILL_ILLOPN, get_check_address(regs));
 559 #endif
 560
 561 asmlinkage void data_exception(struct pt_regs * regs, long interruption_code)
 562 {
 563         __u16 *location;
 564         int signal = 0;
 565
 566         location = (__u16 *) get_check_address(regs);
 567
 568         /*
 569          * We got all needed information from the lowcore and can
 570          * now safely switch on interrupts.
 571          */
 572         if (regs->psw.mask & PSW_MASK_PSTATE)
 573                 local_irq_enable();
 574
 575         if (MACHINE_HAS_IEEE)
 576                 __asm__ volatile ("stfpc %0\n\t"
 577                                   : "=m" (current->thread.fp_regs.fpc));
 578
 579 #ifdef CONFIG_MATHEMU
 580         else if (regs->psw.mask & PSW_MASK_PSTATE) {
 581                 __u8 opcode[6];
 582                 get_user(*((__u16 *) opcode), location);
 583                 switch (opcode[0]) {
 584                 case 0x28: /* LDR Rx,Ry   */
 585                         signal = math_emu_ldr(opcode);
 586                         break;
 587                 case 0x38: /* LER Rx,Ry   */
 588                         signal = math_emu_ler(opcode);
 589                         break;
 590                 case 0x60: /* STD R,D(X,B) */
 591                         get_user(*((__u16 *) (opcode+2)), location+1);
 592                         signal = math_emu_std(opcode, regs);
 593                         break;
 594                 case 0x68: /* LD R,D(X,B) */
 595                         get_user(*((__u16 *) (opcode+2)), location+1);
 596                         signal = math_emu_ld(opcode, regs);
 597                         break;
 598                 case 0x70: /* STE R,D(X,B) */
 599                         get_user(*((__u16 *) (opcode+2)), location+1);
 600                         signal = math_emu_ste(opcode, regs);
 601                         break;
 602                 case 0x78: /* LE R,D(X,B) */
 603                         get_user(*((__u16 *) (opcode+2)), location+1);
 604                         signal = math_emu_le(opcode, regs);
 605                         break;
 606                 case 0xb3:
 607                         get_user(*((__u16 *) (opcode+2)), location+1);
 608                         signal = math_emu_b3(opcode, regs);
 609                         break;
 610                 case 0xed:
 611                         get_user(*((__u32 *) (opcode+2)),
 612                                  (__u32 *)(location+1));
 613                         signal = math_emu_ed(opcode, regs);
 614                         break;
 615                 case 0xb2:
 616                         if (opcode[1] == 0x99) {
 617                                 get_user(*((__u16 *) (opcode+2)), location+1);
 618                                 signal = math_emu_srnm(opcode, regs);
 619                         } else if (opcode[1] == 0x9c) {
 620                                 get_user(*((__u16 *) (opcode+2)), location+1);
 621                                 signal = math_emu_stfpc(opcode, regs);
 622                         } else if (opcode[1] == 0x9d) {
 623                                 get_user(*((__u16 *) (opcode+2)), location+1);
 624                                 signal = math_emu_lfpc(opcode, regs);
 625                         } else
 626                                 signal = SIGILL;
 627                         break;
 628                 default:
 629                         signal = SIGILL;
 630                         break;
 631                 }
 632         }
 633 #endif
 634         if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
 635                 signal = SIGFPE;
 636         else
 637                 signal = SIGILL;
 638         if (signal == SIGFPE)
 639                 do_fp_trap(regs, location,
 640                            current->thread.fp_regs.fpc, interruption_code);
 641         else if (signal) {
 642                 siginfo_t info;
 643                 info.si_signo = signal;
 644                 info.si_errno = 0;
 645                 info.si_code = ILL_ILLOPN;
 646                 info.si_addr = location;
 647                 do_trap(interruption_code, signal,
 648                         "data exception", regs, &info);
 649         }
 650 }
 651
 652 asmlinkage void space_switch_exception(struct pt_regs * regs, long int_code)
 653 {
 654         siginfo_t info;
 655
 656         /* Set user psw back to home space mode. */
 657         if (regs->psw.mask & PSW_MASK_PSTATE)
 658                 regs->psw.mask |= PSW_ASC_HOME;
 659         /* Send SIGILL. */
 660         info.si_signo = SIGILL;
 661         info.si_errno = 0;
 662         info.si_code = ILL_PRVOPC;
 663         info.si_addr = get_check_address(regs);
 664         do_trap(int_code, SIGILL, "space switch event", regs, &info);
 665 }
 666
 667 asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
 668 {
 669         bust_spinlocks(1);
 670         printk("Kernel stack overflow.\n");
 671         show_regs(regs);
 672         bust_spinlocks(0);
 673         panic("Corrupt kernel stack, can't continue.");
 674 }
 675
 676 /* init is done in lowcore.S and head.S */
 677
 678 void __init trap_init(void)
 679 {
 680         int i;
 681
 682         for (i = 0; i < 128; i++)
 683           pgm_check_table[i] = &default_trap_handler;
 684         pgm_check_table[1] = &illegal_op;
 685         pgm_check_table[2] = &privileged_op;
 686         pgm_check_table[3] = &execute_exception;
 687         pgm_check_table[4] = &do_protection_exception;
 688         pgm_check_table[5] = &addressing_exception;
 689         pgm_check_table[6] = &specification_exception;
 690         pgm_check_table[7] = &data_exception;
 691         pgm_check_table[8] = &overflow_exception;
 692         pgm_check_table[9] = &divide_exception;
 693         pgm_check_table[0x0A] = &overflow_exception;
 694         pgm_check_table[0x0B] = &divide_exception;
 695         pgm_check_table[0x0C] = &hfp_overflow_exception;
 696         pgm_check_table[0x0D] = &hfp_underflow_exception;
 697         pgm_check_table[0x0E] = &hfp_significance_exception;
 698         pgm_check_table[0x0F] = &hfp_divide_exception;
 699         pgm_check_table[0x10] = &do_dat_exception;
 700         pgm_check_table[0x11] = &do_dat_exception;
 701         pgm_check_table[0x12] = &translation_exception;
 702         pgm_check_table[0x13] = &special_op_exception;
 703 #ifdef CONFIG_64BIT
 704         pgm_check_table[0x38] = &do_dat_exception;
 705         pgm_check_table[0x39] = &do_dat_exception;
 706         pgm_check_table[0x3A] = &do_dat_exception;
 707         pgm_check_table[0x3B] = &do_dat_exception;
 708 #endif /* CONFIG_64BIT */
 709         pgm_check_table[0x15] = &operand_exception;
 710         pgm_check_table[0x1C] = &space_switch_exception;
 711         pgm_check_table[0x1D] = &hfp_sqrt_exception;
 712         pgm_check_table[0x40] = &do_monitor_call;
 713
 714         if (MACHINE_IS_VM) {
 715 #ifdef CONFIG_PFAULT
 716                 /*
 717                  * Try to get pfault pseudo page faults going.
 718                  */
 719                 if (register_early_external_interrupt(0x2603, pfault_interrupt,
 720                                                       &ext_int_pfault) != 0)
 721                         panic("Couldn't request external interrupt 0x2603");
 722
 723                 if (pfault_init() == 0)
 724                         return;
 725
 726                 /* Tough luck, no pfault. */
 727                 unregister_early_external_interrupt(0x2603, pfault_interrupt,
 728                                                     &ext_int_pfault);
 729 #endif
 730         }
 731 }