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/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
  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 extern pgm_check_handler_t do_pseudo_page_fault;
  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_ARCH_S390X
  71 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
  72 static int kstack_depth_to_print = 12;
  73 #else /* CONFIG_ARCH_S390X */
  74 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
  75 static int kstack_depth_to_print = 20;
  76 #endif /* CONFIG_ARCH_S390X */
  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->thread_info,
 140                              (unsigned long) task->thread_info + 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         // debugging aid: "show_stack(NULL);" prints the
 154         // back trace for this cpu.
 155
 156         if (!sp)
 157                 sp = task ? (unsigned long *) task->thread.ksp : __r15;
 158
 159         stack = sp;
 160         for (i = 0; i < kstack_depth_to_print; i++) {
 161                 if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
 162                         break;
 163                 if (i && ((i * sizeof (long) % 32) == 0))
 164                         printk("\n       ");
 165                 printk("%p ", (void *)*stack++);
 166         }
 167         printk("\n");
 168         show_trace(task, sp);
 169 }
 170
 171 /*
 172  * The architecture-independent dump_stack generator
 173  */
 174 void dump_stack(void)
 175 {
 176         show_stack(0, 0);
 177 }
 178
 179 EXPORT_SYMBOL(dump_stack);
 180
 181 void show_registers(struct pt_regs *regs)
 182 {
 183         mm_segment_t old_fs;
 184         char *mode;
 185         int i;
 186
 187         mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
 188         printk("%s PSW : %p %p",
 189                mode, (void *) regs->psw.mask,
 190                (void *) regs->psw.addr);
 191         print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
 192         printk("%s GPRS: " FOURLONG, mode,
 193                regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
 194         printk("           " FOURLONG,
 195                regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
 196         printk("           " FOURLONG,
 197                regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
 198         printk("           " FOURLONG,
 199                regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
 200
 201 #if 0
 202         /* FIXME: this isn't needed any more but it changes the ksymoops
 203          * input. To remove or not to remove ... */
 204         save_access_regs(regs->acrs);
 205         printk("%s ACRS: %08x %08x %08x %08x\n", mode,
 206                regs->acrs[0], regs->acrs[1], regs->acrs[2], regs->acrs[3]);
 207         printk("           %08x %08x %08x %08x\n",
 208                regs->acrs[4], regs->acrs[5], regs->acrs[6], regs->acrs[7]);
 209         printk("           %08x %08x %08x %08x\n",
 210                regs->acrs[8], regs->acrs[9], regs->acrs[10], regs->acrs[11]);
 211         printk("           %08x %08x %08x %08x\n",
 212                regs->acrs[12], regs->acrs[13], regs->acrs[14], regs->acrs[15]);
 213 #endif
 214
 215         /*
 216          * Print the first 20 byte of the instruction stream at the
 217          * time of the fault.
 218          */
 219         old_fs = get_fs();
 220         if (regs->psw.mask & PSW_MASK_PSTATE)
 221                 set_fs(USER_DS);
 222         else
 223                 set_fs(KERNEL_DS);
 224         printk("%s Code: ", mode);
 225         for (i = 0; i < 20; i++) {
 226                 unsigned char c;
 227                 if (__get_user(c, (char __user *)(regs->psw.addr + i))) {
 228                         printk(" Bad PSW.");
 229                         break;
 230                 }
 231                 printk("%02x ", c);
 232         }
 233         set_fs(old_fs);
 234
 235         printk("\n");
 236 }
 237
 238 /* This is called from fs/proc/array.c */
 239 char *task_show_regs(struct task_struct *task, char *buffer)
 240 {
 241         struct pt_regs *regs;
 242
 243         regs = __KSTK_PTREGS(task);
 244         buffer += sprintf(buffer, "task: %p, ksp: %p\n",
 245                        task, (void *)task->thread.ksp);
 246         buffer += sprintf(buffer, "User PSW : %p %p\n",
 247                        (void *) regs->psw.mask, (void *)regs->psw.addr);
 248
 249         buffer += sprintf(buffer, "User GPRS: " FOURLONG,
 250                           regs->gprs[0], regs->gprs[1],
 251                           regs->gprs[2], regs->gprs[3]);
 252         buffer += sprintf(buffer, "           " FOURLONG,
 253                           regs->gprs[4], regs->gprs[5],
 254                           regs->gprs[6], regs->gprs[7]);
 255         buffer += sprintf(buffer, "           " FOURLONG,
 256                           regs->gprs[8], regs->gprs[9],
 257                           regs->gprs[10], regs->gprs[11]);
 258         buffer += sprintf(buffer, "           " FOURLONG,
 259                           regs->gprs[12], regs->gprs[13],
 260                           regs->gprs[14], regs->gprs[15]);
 261         buffer += sprintf(buffer, "User ACRS: %08x %08x %08x %08x\n",
 262                           task->thread.acrs[0], task->thread.acrs[1],
 263                           task->thread.acrs[2], task->thread.acrs[3]);
 264         buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
 265                           task->thread.acrs[4], task->thread.acrs[5],
 266                           task->thread.acrs[6], task->thread.acrs[7]);
 267         buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
 268                           task->thread.acrs[8], task->thread.acrs[9],
 269                           task->thread.acrs[10], task->thread.acrs[11]);
 270         buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
 271                           task->thread.acrs[12], task->thread.acrs[13],
 272                           task->thread.acrs[14], task->thread.acrs[15]);
 273         return buffer;
 274 }
 275
 276 DEFINE_SPINLOCK(die_lock);
 277
 278 void die(const char * str, struct pt_regs * regs, long err)
 279 {
 280         static int die_counter;
 281
 282         debug_stop_all();
 283         console_verbose();
 284         spin_lock_irq(&die_lock);
 285         bust_spinlocks(1);
 286         printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
 287         show_regs(regs);
 288         bust_spinlocks(0);
 289         spin_unlock_irq(&die_lock);
 290         if (in_interrupt())
 291                 panic("Fatal exception in interrupt");
 292         if (panic_on_oops)
 293                 panic("Fatal exception: panic_on_oops");
 294         do_exit(SIGSEGV);
 295 }
 296
 297 static void inline
 298 report_user_fault(long interruption_code, struct pt_regs *regs)
 299 {
 300 #if defined(CONFIG_SYSCTL)
 301         if (!sysctl_userprocess_debug)
 302                 return;
 303 #endif
 304 #if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG)
 305         printk("User process fault: interruption code 0x%lX\n",
 306                interruption_code);
 307         show_regs(regs);
 308 #endif
 309 }
 310
 311 static void inline do_trap(long interruption_code, int signr, char *str,
 312                            struct pt_regs *regs, siginfo_t *info)
 313 {
 314         /*
 315          * We got all needed information from the lowcore and can
 316          * now safely switch on interrupts.
 317          */
 318         if (regs->psw.mask & PSW_MASK_PSTATE)
 319                 local_irq_enable();
 320
 321         if (regs->psw.mask & PSW_MASK_PSTATE) {
 322                 struct task_struct *tsk = current;
 323
 324                 tsk->thread.trap_no = interruption_code & 0xffff;
 325                 force_sig_info(signr, info, tsk);
 326                 report_user_fault(interruption_code, regs);
 327         } else {
 328                 const struct exception_table_entry *fixup;
 329                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
 330                 if (fixup)
 331                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
 332                 else
 333                         die(str, regs, interruption_code);
 334         }
 335 }
 336
 337 static inline void *get_check_address(struct pt_regs *regs)
 338 {
 339         return (void *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
 340 }
 341
 342 void do_single_step(struct pt_regs *regs)
 343 {
 344         if ((current->ptrace & PT_PTRACED) != 0)
 345                 force_sig(SIGTRAP, current);
 346 }
 347
 348 asmlinkage void
 349 default_trap_handler(struct pt_regs * regs, long interruption_code)
 350 {
 351         if (regs->psw.mask & PSW_MASK_PSTATE) {
 352                 local_irq_enable();
 353                 do_exit(SIGSEGV);
 354                 report_user_fault(interruption_code, regs);
 355         } else
 356                 die("Unknown program exception", regs, interruption_code);
 357 }
 358
 359 #define DO_ERROR_INFO(signr, str, name, sicode, siaddr) \
 360 asmlinkage void name(struct pt_regs * regs, long interruption_code) \
 361 { \
 362         siginfo_t info; \
 363         info.si_signo = signr; \
 364         info.si_errno = 0; \
 365         info.si_code = sicode; \
 366         info.si_addr = (void *)siaddr; \
 367         do_trap(interruption_code, signr, str, regs, &info); \
 368 }
 369
 370 DO_ERROR_INFO(SIGILL, "addressing exception", addressing_exception,
 371               ILL_ILLADR, get_check_address(regs))
 372 DO_ERROR_INFO(SIGILL,  "execute exception", execute_exception,
 373               ILL_ILLOPN, get_check_address(regs))
 374 DO_ERROR_INFO(SIGFPE,  "fixpoint divide exception", divide_exception,
 375               FPE_INTDIV, get_check_address(regs))
 376 DO_ERROR_INFO(SIGFPE,  "fixpoint overflow exception", overflow_exception,
 377               FPE_INTOVF, get_check_address(regs))
 378 DO_ERROR_INFO(SIGFPE,  "HFP overflow exception", hfp_overflow_exception,
 379               FPE_FLTOVF, get_check_address(regs))
 380 DO_ERROR_INFO(SIGFPE,  "HFP underflow exception", hfp_underflow_exception,
 381               FPE_FLTUND, get_check_address(regs))
 382 DO_ERROR_INFO(SIGFPE,  "HFP significance exception", hfp_significance_exception,
 383               FPE_FLTRES, get_check_address(regs))
 384 DO_ERROR_INFO(SIGFPE,  "HFP divide exception", hfp_divide_exception,
 385               FPE_FLTDIV, get_check_address(regs))
 386 DO_ERROR_INFO(SIGFPE,  "HFP square root exception", hfp_sqrt_exception,
 387               FPE_FLTINV, get_check_address(regs))
 388 DO_ERROR_INFO(SIGILL,  "operand exception", operand_exception,
 389               ILL_ILLOPN, get_check_address(regs))
 390 DO_ERROR_INFO(SIGILL,  "privileged operation", privileged_op,
 391               ILL_PRVOPC, get_check_address(regs))
 392 DO_ERROR_INFO(SIGILL,  "special operation exception", special_op_exception,
 393               ILL_ILLOPN, get_check_address(regs))
 394 DO_ERROR_INFO(SIGILL,  "translation exception", translation_exception,
 395               ILL_ILLOPN, get_check_address(regs))
 396
 397 static inline void
 398 do_fp_trap(struct pt_regs *regs, void *location,
 399            int fpc, long interruption_code)
 400 {
 401         siginfo_t si;
 402
 403         si.si_signo = SIGFPE;
 404         si.si_errno = 0;
 405         si.si_addr = location;
 406         si.si_code = 0;
 407         /* FPC[2] is Data Exception Code */
 408         if ((fpc & 0x00000300) == 0) {
 409                 /* bits 6 and 7 of DXC are 0 iff IEEE exception */
 410                 if (fpc & 0x8000) /* invalid fp operation */
 411                         si.si_code = FPE_FLTINV;
 412                 else if (fpc & 0x4000) /* div by 0 */
 413                         si.si_code = FPE_FLTDIV;
 414                 else if (fpc & 0x2000) /* overflow */
 415                         si.si_code = FPE_FLTOVF;
 416                 else if (fpc & 0x1000) /* underflow */
 417                         si.si_code = FPE_FLTUND;
 418                 else if (fpc & 0x0800) /* inexact */
 419                         si.si_code = FPE_FLTRES;
 420         }
 421         current->thread.ieee_instruction_pointer = (addr_t) location;
 422         do_trap(interruption_code, SIGFPE,
 423                 "floating point exception", regs, &si);
 424 }
 425
 426 asmlinkage void illegal_op(struct pt_regs * regs, long interruption_code)
 427 {
 428         siginfo_t info;
 429         __u8 opcode[6];
 430         __u16 *location;
 431         int signal = 0;
 432
 433         location = (__u16 *) get_check_address(regs);
 434
 435         /*
 436          * We got all needed information from the lowcore and can
 437          * now safely switch on interrupts.
 438          */
 439         if (regs->psw.mask & PSW_MASK_PSTATE)
 440                 local_irq_enable();
 441
 442         if (regs->psw.mask & PSW_MASK_PSTATE) {
 443                 get_user(*((__u16 *) opcode), (__u16 __user *) location);
 444                 if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
 445                         if (current->ptrace & PT_PTRACED)
 446                                 force_sig(SIGTRAP, current);
 447                         else
 448                                 signal = SIGILL;
 449 #ifdef CONFIG_MATHEMU
 450                 } else if (opcode[0] == 0xb3) {
 451                         get_user(*((__u16 *) (opcode+2)), location+1);
 452                         signal = math_emu_b3(opcode, regs);
 453                 } else if (opcode[0] == 0xed) {
 454                         get_user(*((__u32 *) (opcode+2)),
 455                                  (__u32 *)(location+1));
 456                         signal = math_emu_ed(opcode, regs);
 457                 } else if (*((__u16 *) opcode) == 0xb299) {
 458                         get_user(*((__u16 *) (opcode+2)), location+1);
 459                         signal = math_emu_srnm(opcode, regs);
 460                 } else if (*((__u16 *) opcode) == 0xb29c) {
 461                         get_user(*((__u16 *) (opcode+2)), location+1);
 462                         signal = math_emu_stfpc(opcode, regs);
 463                 } else if (*((__u16 *) opcode) == 0xb29d) {
 464                         get_user(*((__u16 *) (opcode+2)), location+1);
 465                         signal = math_emu_lfpc(opcode, regs);
 466 #endif
 467                 } else
 468                         signal = SIGILL;
 469         } else
 470                 signal = SIGILL;
 471
 472 #ifdef CONFIG_MATHEMU
 473         if (signal == SIGFPE)
 474                 do_fp_trap(regs, location,
 475                            current->thread.fp_regs.fpc, interruption_code);
 476         else if (signal == SIGSEGV) {
 477                 info.si_signo = signal;
 478                 info.si_errno = 0;
 479                 info.si_code = SEGV_MAPERR;
 480                 info.si_addr = (void *) location;
 481                 do_trap(interruption_code, signal,
 482                         "user address fault", regs, &info);
 483         } else
 484 #endif
 485         if (signal) {
 486                 info.si_signo = signal;
 487                 info.si_errno = 0;
 488                 info.si_code = ILL_ILLOPC;
 489                 info.si_addr = (void *) location;
 490                 do_trap(interruption_code, signal,
 491                         "illegal operation", regs, &info);
 492         }
 493 }
 494
 495
 496 #ifdef CONFIG_MATHEMU
 497 asmlinkage void
 498 specification_exception(struct pt_regs * regs, long interruption_code)
 499 {
 500         __u8 opcode[6];
 501         __u16 *location = NULL;
 502         int signal = 0;
 503
 504         location = (__u16 *) get_check_address(regs);
 505
 506         /*
 507          * We got all needed information from the lowcore and can
 508          * now safely switch on interrupts.
 509          */
 510         if (regs->psw.mask & PSW_MASK_PSTATE)
 511                 local_irq_enable();
 512
 513         if (regs->psw.mask & PSW_MASK_PSTATE) {
 514                 get_user(*((__u16 *) opcode), location);
 515                 switch (opcode[0]) {
 516                 case 0x28: /* LDR Rx,Ry   */
 517                         signal = math_emu_ldr(opcode);
 518                         break;
 519                 case 0x38: /* LER Rx,Ry   */
 520                         signal = math_emu_ler(opcode);
 521                         break;
 522                 case 0x60: /* STD R,D(X,B) */
 523                         get_user(*((__u16 *) (opcode+2)), location+1);
 524                         signal = math_emu_std(opcode, regs);
 525                         break;
 526                 case 0x68: /* LD R,D(X,B) */
 527                         get_user(*((__u16 *) (opcode+2)), location+1);
 528                         signal = math_emu_ld(opcode, regs);
 529                         break;
 530                 case 0x70: /* STE R,D(X,B) */
 531                         get_user(*((__u16 *) (opcode+2)), location+1);
 532                         signal = math_emu_ste(opcode, regs);
 533                         break;
 534                 case 0x78: /* LE R,D(X,B) */
 535                         get_user(*((__u16 *) (opcode+2)), location+1);
 536                         signal = math_emu_le(opcode, regs);
 537                         break;
 538                 default:
 539                         signal = SIGILL;
 540                         break;
 541                 }
 542         } else
 543                 signal = SIGILL;
 544
 545         if (signal == SIGFPE)
 546                 do_fp_trap(regs, location,
 547                            current->thread.fp_regs.fpc, interruption_code);
 548         else if (signal) {
 549                 siginfo_t info;
 550                 info.si_signo = signal;
 551                 info.si_errno = 0;
 552                 info.si_code = ILL_ILLOPN;
 553                 info.si_addr = location;
 554                 do_trap(interruption_code, signal,
 555                         "specification exception", regs, &info);
 556         }
 557 }
 558 #else
 559 DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
 560               ILL_ILLOPN, get_check_address(regs));
 561 #endif
 562
 563 asmlinkage void data_exception(struct pt_regs * regs, long interruption_code)
 564 {
 565         __u16 *location;
 566         int signal = 0;
 567
 568         location = (__u16 *) get_check_address(regs);
 569
 570         /*
 571          * We got all needed information from the lowcore and can
 572          * now safely switch on interrupts.
 573          */
 574         if (regs->psw.mask & PSW_MASK_PSTATE)
 575                 local_irq_enable();
 576
 577         if (MACHINE_HAS_IEEE)
 578                 __asm__ volatile ("stfpc %0\n\t"
 579                                   : "=m" (current->thread.fp_regs.fpc));
 580
 581 #ifdef CONFIG_MATHEMU
 582         else if (regs->psw.mask & PSW_MASK_PSTATE) {
 583                 __u8 opcode[6];
 584                 get_user(*((__u16 *) opcode), location);
 585                 switch (opcode[0]) {
 586                 case 0x28: /* LDR Rx,Ry   */
 587                         signal = math_emu_ldr(opcode);
 588                         break;
 589                 case 0x38: /* LER Rx,Ry   */
 590                         signal = math_emu_ler(opcode);
 591                         break;
 592                 case 0x60: /* STD R,D(X,B) */
 593                         get_user(*((__u16 *) (opcode+2)), location+1);
 594                         signal = math_emu_std(opcode, regs);
 595                         break;
 596                 case 0x68: /* LD R,D(X,B) */
 597                         get_user(*((__u16 *) (opcode+2)), location+1);
 598                         signal = math_emu_ld(opcode, regs);
 599                         break;
 600                 case 0x70: /* STE R,D(X,B) */
 601                         get_user(*((__u16 *) (opcode+2)), location+1);
 602                         signal = math_emu_ste(opcode, regs);
 603                         break;
 604                 case 0x78: /* LE R,D(X,B) */
 605                         get_user(*((__u16 *) (opcode+2)), location+1);
 606                         signal = math_emu_le(opcode, regs);
 607                         break;
 608                 case 0xb3:
 609                         get_user(*((__u16 *) (opcode+2)), location+1);
 610                         signal = math_emu_b3(opcode, regs);
 611                         break;
 612                 case 0xed:
 613                         get_user(*((__u32 *) (opcode+2)),
 614                                  (__u32 *)(location+1));
 615                         signal = math_emu_ed(opcode, regs);
 616                         break;
 617                 case 0xb2:
 618                         if (opcode[1] == 0x99) {
 619                                 get_user(*((__u16 *) (opcode+2)), location+1);
 620                                 signal = math_emu_srnm(opcode, regs);
 621                         } else if (opcode[1] == 0x9c) {
 622                                 get_user(*((__u16 *) (opcode+2)), location+1);
 623                                 signal = math_emu_stfpc(opcode, regs);
 624                         } else if (opcode[1] == 0x9d) {
 625                                 get_user(*((__u16 *) (opcode+2)), location+1);
 626                                 signal = math_emu_lfpc(opcode, regs);
 627                         } else
 628                                 signal = SIGILL;
 629                         break;
 630                 default:
 631                         signal = SIGILL;
 632                         break;
 633                 }
 634         }
 635 #endif
 636         if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
 637                 signal = SIGFPE;
 638         else
 639                 signal = SIGILL;
 640         if (signal == SIGFPE)
 641                 do_fp_trap(regs, location,
 642                            current->thread.fp_regs.fpc, interruption_code);
 643         else if (signal) {
 644                 siginfo_t info;
 645                 info.si_signo = signal;
 646                 info.si_errno = 0;
 647                 info.si_code = ILL_ILLOPN;
 648                 info.si_addr = location;
 649                 do_trap(interruption_code, signal,
 650                         "data exception", regs, &info);
 651         }
 652 }
 653
 654 asmlinkage void space_switch_exception(struct pt_regs * regs, long int_code)
 655 {
 656         siginfo_t info;
 657
 658         /* Set user psw back to home space mode. */
 659         if (regs->psw.mask & PSW_MASK_PSTATE)
 660                 regs->psw.mask |= PSW_ASC_HOME;
 661         /* Send SIGILL. */
 662         info.si_signo = SIGILL;
 663         info.si_errno = 0;
 664         info.si_code = ILL_PRVOPC;
 665         info.si_addr = get_check_address(regs);
 666         do_trap(int_code, SIGILL, "space switch event", regs, &info);
 667 }
 668
 669 asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
 670 {
 671         die("Kernel stack overflow", regs, 0);
 672         panic("Corrupt kernel stack, can't continue.");
 673 }
 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 #ifndef CONFIG_ARCH_S390X
 704         pgm_check_table[0x14] = &do_pseudo_page_fault;
 705 #else /* CONFIG_ARCH_S390X */
 706         pgm_check_table[0x38] = &do_dat_exception;
 707         pgm_check_table[0x39] = &do_dat_exception;
 708         pgm_check_table[0x3A] = &do_dat_exception;
 709         pgm_check_table[0x3B] = &do_dat_exception;
 710 #endif /* CONFIG_ARCH_S390X */
 711         pgm_check_table[0x15] = &operand_exception;
 712         pgm_check_table[0x1C] = &space_switch_exception;
 713         pgm_check_table[0x1D] = &hfp_sqrt_exception;
 714         pgm_check_table[0x40] = &do_monitor_call;
 715
 716         if (MACHINE_IS_VM) {
 717                 /*
 718                  * First try to get pfault pseudo page faults going.
 719                  * If this isn't available turn on pagex page faults.
 720                  */
 721 #ifdef CONFIG_PFAULT
 722                 /* request the 0x2603 external interrupt */
 723                 if (register_early_external_interrupt(0x2603, pfault_interrupt,
 724                                                       &ext_int_pfault) != 0)
 725                         panic("Couldn't request external interrupt 0x2603");
 726
 727                 if (pfault_init() == 0)
 728                         return;
 729
 730                 /* Tough luck, no pfault. */
 731                 unregister_early_external_interrupt(0x2603, pfault_interrupt,
 732                                                     &ext_int_pfault);
 733 #endif
 734 #ifndef CONFIG_ARCH_S390X
 735                 cpcmd("SET PAGEX ON", NULL, 0);
 736 #endif
 737         }
 738 }