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 #include <linux/kprobes.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 #include <asm/kdebug.h>
  44
  45 /* Called from entry.S only */
  46 extern void handle_per_exception(struct pt_regs *regs);
  47
  48 typedef void pgm_check_handler_t(struct pt_regs *, long);
  49 pgm_check_handler_t *pgm_check_table[128];
  50
  51 #ifdef CONFIG_SYSCTL
  52 #ifdef CONFIG_PROCESS_DEBUG
  53 int sysctl_userprocess_debug = 1;
  54 #else
  55 int sysctl_userprocess_debug = 0;
  56 #endif
  57 #endif
  58
  59 extern pgm_check_handler_t do_protection_exception;
  60 extern pgm_check_handler_t do_dat_exception;
  61 #ifdef CONFIG_PFAULT
  62 extern int pfault_init(void);
  63 extern void pfault_fini(void);
  64 extern void pfault_interrupt(struct pt_regs *regs, __u16 error_code);
  65 static ext_int_info_t ext_int_pfault;
  66 #endif
  67 extern pgm_check_handler_t do_monitor_call;
  68
  69 #define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
  70
  71 #ifndef CONFIG_64BIT
  72 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
  73 static int kstack_depth_to_print = 12;
  74 #else /* CONFIG_64BIT */
  75 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
  76 static int kstack_depth_to_print = 20;
  77 #endif /* CONFIG_64BIT */
  78
  79 ATOMIC_NOTIFIER_HEAD(s390die_chain);
  80
  81 int register_die_notifier(struct notifier_block *nb)
  82 {
  83         return atomic_notifier_chain_register(&s390die_chain, nb);
  84 }
  85 EXPORT_SYMBOL(register_die_notifier);
  86
  87 int unregister_die_notifier(struct notifier_block *nb)
  88 {
  89         return atomic_notifier_chain_unregister(&s390die_chain, nb);
  90 }
  91 EXPORT_SYMBOL(unregister_die_notifier);
  92
  93 /*
  94  * For show_trace we have tree different stack to consider:
  95  *   - the panic stack which is used if the kernel stack has overflown
  96  *   - the asynchronous interrupt stack (cpu related)
  97  *   - the synchronous kernel stack (process related)
  98  * The stack trace can start at any of the three stack and can potentially
  99  * touch all of them. The order is: panic stack, async stack, sync stack.
 100  */
 101 static unsigned long
 102 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
 103 {
 104         struct stack_frame *sf;
 105         struct pt_regs *regs;
 106
 107         while (1) {
 108                 sp = sp & PSW_ADDR_INSN;
 109                 if (sp < low || sp > high - sizeof(*sf))
 110                         return sp;
 111                 sf = (struct stack_frame *) sp;
 112                 printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
 113                 print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
 114                 /* Follow the backchain. */
 115                 while (1) {
 116                         low = sp;
 117                         sp = sf->back_chain & PSW_ADDR_INSN;
 118                         if (!sp)
 119                                 break;
 120                         if (sp <= low || sp > high - sizeof(*sf))
 121                                 return sp;
 122                         sf = (struct stack_frame *) sp;
 123                         printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
 124                         print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
 125                 }
 126                 /* Zero backchain detected, check for interrupt frame. */
 127                 sp = (unsigned long) (sf + 1);
 128                 if (sp <= low || sp > high - sizeof(*regs))
 129                         return sp;
 130                 regs = (struct pt_regs *) sp;
 131                 printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
 132                 print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
 133                 low = sp;
 134                 sp = regs->gprs[15];
 135         }
 136 }
 137
 138 void show_trace(struct task_struct *task, unsigned long * stack)
 139 {
 140         register unsigned long __r15 asm ("15");
 141         unsigned long sp;
 142
 143         sp = (unsigned long) stack;
 144         if (!sp)
 145                 sp = task ? task->thread.ksp : __r15;
 146         printk("Call Trace:\n");
 147 #ifdef CONFIG_CHECK_STACK
 148         sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
 149                           S390_lowcore.panic_stack);
 150 #endif
 151         sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
 152                           S390_lowcore.async_stack);
 153         if (task)
 154                 __show_trace(sp, (unsigned long) task_stack_page(task),
 155                              (unsigned long) task_stack_page(task) + THREAD_SIZE);
 156         else
 157                 __show_trace(sp, S390_lowcore.thread_info,
 158                              S390_lowcore.thread_info + THREAD_SIZE);
 159         printk("\n");
 160 }
 161
 162 void show_stack(struct task_struct *task, unsigned long *sp)
 163 {
 164         register unsigned long * __r15 asm ("15");
 165         unsigned long *stack;
 166         int i;
 167
 168         if (!sp)
 169                 stack = task ? (unsigned long *) task->thread.ksp : __r15;
 170         else
 171                 stack = sp;
 172
 173         for (i = 0; i < kstack_depth_to_print; i++) {
 174                 if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
 175                         break;
 176                 if (i && ((i * sizeof (long) % 32) == 0))
 177                         printk("\n       ");
 178                 printk("%p ", (void *)*stack++);
 179         }
 180         printk("\n");
 181         show_trace(task, sp);
 182 }
 183
 184 /*
 185  * The architecture-independent dump_stack generator
 186  */
 187 void dump_stack(void)
 188 {
 189         show_stack(NULL, NULL);
 190 }
 191
 192 EXPORT_SYMBOL(dump_stack);
 193
 194 void show_registers(struct pt_regs *regs)
 195 {
 196         mm_segment_t old_fs;
 197         char *mode;
 198         int i;
 199
 200         mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
 201         printk("%s PSW : %p %p",
 202                mode, (void *) regs->psw.mask,
 203                (void *) regs->psw.addr);
 204         print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
 205         printk("%s GPRS: " FOURLONG, mode,
 206                regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
 207         printk("           " FOURLONG,
 208                regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
 209         printk("           " FOURLONG,
 210                regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
 211         printk("           " FOURLONG,
 212                regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
 213
 214 #if 0
 215         /* FIXME: this isn't needed any more but it changes the ksymoops
 216          * input. To remove or not to remove ... */
 217         save_access_regs(regs->acrs);
 218         printk("%s ACRS: %08x %08x %08x %08x\n", mode,
 219                regs->acrs[0], regs->acrs[1], regs->acrs[2], regs->acrs[3]);
 220         printk("           %08x %08x %08x %08x\n",
 221                regs->acrs[4], regs->acrs[5], regs->acrs[6], regs->acrs[7]);
 222         printk("           %08x %08x %08x %08x\n",
 223                regs->acrs[8], regs->acrs[9], regs->acrs[10], regs->acrs[11]);
 224         printk("           %08x %08x %08x %08x\n",
 225                regs->acrs[12], regs->acrs[13], regs->acrs[14], regs->acrs[15]);
 226 #endif
 227
 228         /*
 229          * Print the first 20 byte of the instruction stream at the
 230          * time of the fault.
 231          */
 232         old_fs = get_fs();
 233         if (regs->psw.mask & PSW_MASK_PSTATE)
 234                 set_fs(USER_DS);
 235         else
 236                 set_fs(KERNEL_DS);
 237         printk("%s Code: ", mode);
 238         for (i = 0; i < 20; i++) {
 239                 unsigned char c;
 240                 if (__get_user(c, (char __user *)(regs->psw.addr + i))) {
 241                         printk(" Bad PSW.");
 242                         break;
 243                 }
 244                 printk("%02x ", c);
 245         }
 246         set_fs(old_fs);
 247
 248         printk("\n");
 249 }
 250
 251 /* This is called from fs/proc/array.c */
 252 char *task_show_regs(struct task_struct *task, char *buffer)
 253 {
 254         struct pt_regs *regs;
 255
 256         regs = task_pt_regs(task);
 257         buffer += sprintf(buffer, "task: %p, ksp: %p\n",
 258                        task, (void *)task->thread.ksp);
 259         buffer += sprintf(buffer, "User PSW : %p %p\n",
 260                        (void *) regs->psw.mask, (void *)regs->psw.addr);
 261
 262         buffer += sprintf(buffer, "User GPRS: " FOURLONG,
 263                           regs->gprs[0], regs->gprs[1],
 264                           regs->gprs[2], regs->gprs[3]);
 265         buffer += sprintf(buffer, "           " FOURLONG,
 266                           regs->gprs[4], regs->gprs[5],
 267                           regs->gprs[6], regs->gprs[7]);
 268         buffer += sprintf(buffer, "           " FOURLONG,
 269                           regs->gprs[8], regs->gprs[9],
 270                           regs->gprs[10], regs->gprs[11]);
 271         buffer += sprintf(buffer, "           " FOURLONG,
 272                           regs->gprs[12], regs->gprs[13],
 273                           regs->gprs[14], regs->gprs[15]);
 274         buffer += sprintf(buffer, "User ACRS: %08x %08x %08x %08x\n",
 275                           task->thread.acrs[0], task->thread.acrs[1],
 276                           task->thread.acrs[2], task->thread.acrs[3]);
 277         buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
 278                           task->thread.acrs[4], task->thread.acrs[5],
 279                           task->thread.acrs[6], task->thread.acrs[7]);
 280         buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
 281                           task->thread.acrs[8], task->thread.acrs[9],
 282                           task->thread.acrs[10], task->thread.acrs[11]);
 283         buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
 284                           task->thread.acrs[12], task->thread.acrs[13],
 285                           task->thread.acrs[14], task->thread.acrs[15]);
 286         return buffer;
 287 }
 288
 289 DEFINE_SPINLOCK(die_lock);
 290
 291 void die(const char * str, struct pt_regs * regs, long err)
 292 {
 293         static int die_counter;
 294
 295         debug_stop_all();
 296         console_verbose();
 297         spin_lock_irq(&die_lock);
 298         bust_spinlocks(1);
 299         printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
 300         show_regs(regs);
 301         bust_spinlocks(0);
 302         spin_unlock_irq(&die_lock);
 303         if (in_interrupt())
 304                 panic("Fatal exception in interrupt");
 305         if (panic_on_oops)
 306                 panic("Fatal exception: panic_on_oops");
 307         do_exit(SIGSEGV);
 308 }
 309
 310 static void inline
 311 report_user_fault(long interruption_code, struct pt_regs *regs)
 312 {
 313 #if defined(CONFIG_SYSCTL)
 314         if (!sysctl_userprocess_debug)
 315                 return;
 316 #endif
 317 #if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG)
 318         printk("User process fault: interruption code 0x%lX\n",
 319                interruption_code);
 320         show_regs(regs);
 321 #endif
 322 }
 323
 324 static void __kprobes inline do_trap(long interruption_code, int signr,
 325                                         char *str, struct pt_regs *regs,
 326                                         siginfo_t *info)
 327 {
 328         /*
 329          * We got all needed information from the lowcore and can
 330          * now safely switch on interrupts.
 331          */
 332         if (regs->psw.mask & PSW_MASK_PSTATE)
 333                 local_irq_enable();
 334
 335         if (notify_die(DIE_TRAP, str, regs, interruption_code,
 336                                 interruption_code, signr) == NOTIFY_STOP)
 337                 return;
 338
 339         if (regs->psw.mask & PSW_MASK_PSTATE) {
 340                 struct task_struct *tsk = current;
 341
 342                 tsk->thread.trap_no = interruption_code & 0xffff;
 343                 force_sig_info(signr, info, tsk);
 344                 report_user_fault(interruption_code, regs);
 345         } else {
 346                 const struct exception_table_entry *fixup;
 347                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
 348                 if (fixup)
 349                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
 350                 else
 351                         die(str, regs, interruption_code);
 352         }
 353 }
 354
 355 static inline void __user *get_check_address(struct pt_regs *regs)
 356 {
 357         return (void __user *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
 358 }
 359
 360 void __kprobes do_single_step(struct pt_regs *regs)
 361 {
 362         if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0,
 363                                         SIGTRAP) == NOTIFY_STOP){
 364                 return;
 365         }
 366         if ((current->ptrace & PT_PTRACED) != 0)
 367                 force_sig(SIGTRAP, current);
 368 }
 369
 370 asmlinkage void
 371 default_trap_handler(struct pt_regs * regs, long interruption_code)
 372 {
 373         if (regs->psw.mask & PSW_MASK_PSTATE) {
 374                 local_irq_enable();
 375                 do_exit(SIGSEGV);
 376                 report_user_fault(interruption_code, regs);
 377         } else
 378                 die("Unknown program exception", regs, interruption_code);
 379 }
 380
 381 #define DO_ERROR_INFO(signr, str, name, sicode, siaddr) \
 382 asmlinkage void name(struct pt_regs * regs, long interruption_code) \
 383 { \
 384         siginfo_t info; \
 385         info.si_signo = signr; \
 386         info.si_errno = 0; \
 387         info.si_code = sicode; \
 388         info.si_addr = siaddr; \
 389         do_trap(interruption_code, signr, str, regs, &info); \
 390 }
 391
 392 DO_ERROR_INFO(SIGILL, "addressing exception", addressing_exception,
 393               ILL_ILLADR, get_check_address(regs))
 394 DO_ERROR_INFO(SIGILL,  "execute exception", execute_exception,
 395               ILL_ILLOPN, get_check_address(regs))
 396 DO_ERROR_INFO(SIGFPE,  "fixpoint divide exception", divide_exception,
 397               FPE_INTDIV, get_check_address(regs))
 398 DO_ERROR_INFO(SIGFPE,  "fixpoint overflow exception", overflow_exception,
 399               FPE_INTOVF, get_check_address(regs))
 400 DO_ERROR_INFO(SIGFPE,  "HFP overflow exception", hfp_overflow_exception,
 401               FPE_FLTOVF, get_check_address(regs))
 402 DO_ERROR_INFO(SIGFPE,  "HFP underflow exception", hfp_underflow_exception,
 403               FPE_FLTUND, get_check_address(regs))
 404 DO_ERROR_INFO(SIGFPE,  "HFP significance exception", hfp_significance_exception,
 405               FPE_FLTRES, get_check_address(regs))
 406 DO_ERROR_INFO(SIGFPE,  "HFP divide exception", hfp_divide_exception,
 407               FPE_FLTDIV, get_check_address(regs))
 408 DO_ERROR_INFO(SIGFPE,  "HFP square root exception", hfp_sqrt_exception,
 409               FPE_FLTINV, get_check_address(regs))
 410 DO_ERROR_INFO(SIGILL,  "operand exception", operand_exception,
 411               ILL_ILLOPN, get_check_address(regs))
 412 DO_ERROR_INFO(SIGILL,  "privileged operation", privileged_op,
 413               ILL_PRVOPC, get_check_address(regs))
 414 DO_ERROR_INFO(SIGILL,  "special operation exception", special_op_exception,
 415               ILL_ILLOPN, get_check_address(regs))
 416 DO_ERROR_INFO(SIGILL,  "translation exception", translation_exception,
 417               ILL_ILLOPN, get_check_address(regs))
 418
 419 static inline void
 420 do_fp_trap(struct pt_regs *regs, void __user *location,
 421            int fpc, long interruption_code)
 422 {
 423         siginfo_t si;
 424
 425         si.si_signo = SIGFPE;
 426         si.si_errno = 0;
 427         si.si_addr = location;
 428         si.si_code = 0;
 429         /* FPC[2] is Data Exception Code */
 430         if ((fpc & 0x00000300) == 0) {
 431                 /* bits 6 and 7 of DXC are 0 iff IEEE exception */
 432                 if (fpc & 0x8000) /* invalid fp operation */
 433                         si.si_code = FPE_FLTINV;
 434                 else if (fpc & 0x4000) /* div by 0 */
 435                         si.si_code = FPE_FLTDIV;
 436                 else if (fpc & 0x2000) /* overflow */
 437                         si.si_code = FPE_FLTOVF;
 438                 else if (fpc & 0x1000) /* underflow */
 439                         si.si_code = FPE_FLTUND;
 440                 else if (fpc & 0x0800) /* inexact */
 441                         si.si_code = FPE_FLTRES;
 442         }
 443         current->thread.ieee_instruction_pointer = (addr_t) location;
 444         do_trap(interruption_code, SIGFPE,
 445                 "floating point exception", regs, &si);
 446 }
 447
 448 asmlinkage void illegal_op(struct pt_regs * regs, long interruption_code)
 449 {
 450         siginfo_t info;
 451         __u8 opcode[6];
 452         __u16 __user *location;
 453         int signal = 0;
 454
 455         location = get_check_address(regs);
 456
 457         /*
 458          * We got all needed information from the lowcore and can
 459          * now safely switch on interrupts.
 460          */
 461         if (regs->psw.mask & PSW_MASK_PSTATE)
 462                 local_irq_enable();
 463
 464         if (regs->psw.mask & PSW_MASK_PSTATE) {
 465                 get_user(*((__u16 *) opcode), (__u16 __user *) location);
 466                 if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
 467                         if (current->ptrace & PT_PTRACED)
 468                                 force_sig(SIGTRAP, current);
 469                         else
 470                                 signal = SIGILL;
 471 #ifdef CONFIG_MATHEMU
 472                 } else if (opcode[0] == 0xb3) {
 473                         get_user(*((__u16 *) (opcode+2)), location+1);
 474                         signal = math_emu_b3(opcode, regs);
 475                 } else if (opcode[0] == 0xed) {
 476                         get_user(*((__u32 *) (opcode+2)),
 477                                  (__u32 *)(location+1));
 478                         signal = math_emu_ed(opcode, regs);
 479                 } else if (*((__u16 *) opcode) == 0xb299) {
 480                         get_user(*((__u16 *) (opcode+2)), location+1);
 481                         signal = math_emu_srnm(opcode, regs);
 482                 } else if (*((__u16 *) opcode) == 0xb29c) {
 483                         get_user(*((__u16 *) (opcode+2)), location+1);
 484                         signal = math_emu_stfpc(opcode, regs);
 485                 } else if (*((__u16 *) opcode) == 0xb29d) {
 486                         get_user(*((__u16 *) (opcode+2)), location+1);
 487                         signal = math_emu_lfpc(opcode, regs);
 488 #endif
 489                 } else
 490                         signal = SIGILL;
 491         } else
 492                 signal = SIGILL;
 493
 494 #ifdef CONFIG_MATHEMU
 495         if (signal == SIGFPE)
 496                 do_fp_trap(regs, location,
 497                            current->thread.fp_regs.fpc, interruption_code);
 498         else if (signal == SIGSEGV) {
 499                 info.si_signo = signal;
 500                 info.si_errno = 0;
 501                 info.si_code = SEGV_MAPERR;
 502                 info.si_addr = (void *) location;
 503                 do_trap(interruption_code, signal,
 504                         "user address fault", regs, &info);
 505         } else
 506 #endif
 507         if (signal) {
 508                 info.si_signo = signal;
 509                 info.si_errno = 0;
 510                 info.si_code = ILL_ILLOPC;
 511                 info.si_addr = (void __user *) location;
 512                 do_trap(interruption_code, signal,
 513                         "illegal operation", regs, &info);
 514         }
 515 }
 516
 517
 518 #ifdef CONFIG_MATHEMU
 519 asmlinkage void
 520 specification_exception(struct pt_regs * regs, long interruption_code)
 521 {
 522         __u8 opcode[6];
 523         __u16 *location = NULL;
 524         int signal = 0;
 525
 526         location = (__u16 *) get_check_address(regs);
 527
 528         /*
 529          * We got all needed information from the lowcore and can
 530          * now safely switch on interrupts.
 531          */
 532         if (regs->psw.mask & PSW_MASK_PSTATE)
 533                 local_irq_enable();
 534
 535         if (regs->psw.mask & PSW_MASK_PSTATE) {
 536                 get_user(*((__u16 *) opcode), location);
 537                 switch (opcode[0]) {
 538                 case 0x28: /* LDR Rx,Ry   */
 539                         signal = math_emu_ldr(opcode);
 540                         break;
 541                 case 0x38: /* LER Rx,Ry   */
 542                         signal = math_emu_ler(opcode);
 543                         break;
 544                 case 0x60: /* STD R,D(X,B) */
 545                         get_user(*((__u16 *) (opcode+2)), location+1);
 546                         signal = math_emu_std(opcode, regs);
 547                         break;
 548                 case 0x68: /* LD R,D(X,B) */
 549                         get_user(*((__u16 *) (opcode+2)), location+1);
 550                         signal = math_emu_ld(opcode, regs);
 551                         break;
 552                 case 0x70: /* STE R,D(X,B) */
 553                         get_user(*((__u16 *) (opcode+2)), location+1);
 554                         signal = math_emu_ste(opcode, regs);
 555                         break;
 556                 case 0x78: /* LE R,D(X,B) */
 557                         get_user(*((__u16 *) (opcode+2)), location+1);
 558                         signal = math_emu_le(opcode, regs);
 559                         break;
 560                 default:
 561                         signal = SIGILL;
 562                         break;
 563                 }
 564         } else
 565                 signal = SIGILL;
 566
 567         if (signal == SIGFPE)
 568                 do_fp_trap(regs, location,
 569                            current->thread.fp_regs.fpc, interruption_code);
 570         else if (signal) {
 571                 siginfo_t info;
 572                 info.si_signo = signal;
 573                 info.si_errno = 0;
 574                 info.si_code = ILL_ILLOPN;
 575                 info.si_addr = location;
 576                 do_trap(interruption_code, signal,
 577                         "specification exception", regs, &info);
 578         }
 579 }
 580 #else
 581 DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
 582               ILL_ILLOPN, get_check_address(regs));
 583 #endif
 584
 585 asmlinkage void data_exception(struct pt_regs * regs, long interruption_code)
 586 {
 587         __u16 __user *location;
 588         int signal = 0;
 589
 590         location = get_check_address(regs);
 591
 592         /*
 593          * We got all needed information from the lowcore and can
 594          * now safely switch on interrupts.
 595          */
 596         if (regs->psw.mask & PSW_MASK_PSTATE)
 597                 local_irq_enable();
 598
 599         if (MACHINE_HAS_IEEE)
 600                 __asm__ volatile ("stfpc %0\n\t"
 601                                   : "=m" (current->thread.fp_regs.fpc));
 602
 603 #ifdef CONFIG_MATHEMU
 604         else if (regs->psw.mask & PSW_MASK_PSTATE) {
 605                 __u8 opcode[6];
 606                 get_user(*((__u16 *) opcode), location);
 607                 switch (opcode[0]) {
 608                 case 0x28: /* LDR Rx,Ry   */
 609                         signal = math_emu_ldr(opcode);
 610                         break;
 611                 case 0x38: /* LER Rx,Ry   */
 612                         signal = math_emu_ler(opcode);
 613                         break;
 614                 case 0x60: /* STD R,D(X,B) */
 615                         get_user(*((__u16 *) (opcode+2)), location+1);
 616                         signal = math_emu_std(opcode, regs);
 617                         break;
 618                 case 0x68: /* LD R,D(X,B) */
 619                         get_user(*((__u16 *) (opcode+2)), location+1);
 620                         signal = math_emu_ld(opcode, regs);
 621                         break;
 622                 case 0x70: /* STE R,D(X,B) */
 623                         get_user(*((__u16 *) (opcode+2)), location+1);
 624                         signal = math_emu_ste(opcode, regs);
 625                         break;
 626                 case 0x78: /* LE R,D(X,B) */
 627                         get_user(*((__u16 *) (opcode+2)), location+1);
 628                         signal = math_emu_le(opcode, regs);
 629                         break;
 630                 case 0xb3:
 631                         get_user(*((__u16 *) (opcode+2)), location+1);
 632                         signal = math_emu_b3(opcode, regs);
 633                         break;
 634                 case 0xed:
 635                         get_user(*((__u32 *) (opcode+2)),
 636                                  (__u32 *)(location+1));
 637                         signal = math_emu_ed(opcode, regs);
 638                         break;
 639                 case 0xb2:
 640                         if (opcode[1] == 0x99) {
 641                                 get_user(*((__u16 *) (opcode+2)), location+1);
 642                                 signal = math_emu_srnm(opcode, regs);
 643                         } else if (opcode[1] == 0x9c) {
 644                                 get_user(*((__u16 *) (opcode+2)), location+1);
 645                                 signal = math_emu_stfpc(opcode, regs);
 646                         } else if (opcode[1] == 0x9d) {
 647                                 get_user(*((__u16 *) (opcode+2)), location+1);
 648                                 signal = math_emu_lfpc(opcode, regs);
 649                         } else
 650                                 signal = SIGILL;
 651                         break;
 652                 default:
 653                         signal = SIGILL;
 654                         break;
 655                 }
 656         }
 657 #endif
 658         if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
 659                 signal = SIGFPE;
 660         else
 661                 signal = SIGILL;
 662         if (signal == SIGFPE)
 663                 do_fp_trap(regs, location,
 664                            current->thread.fp_regs.fpc, interruption_code);
 665         else if (signal) {
 666                 siginfo_t info;
 667                 info.si_signo = signal;
 668                 info.si_errno = 0;
 669                 info.si_code = ILL_ILLOPN;
 670                 info.si_addr = location;
 671                 do_trap(interruption_code, signal,
 672                         "data exception", regs, &info);
 673         }
 674 }
 675
 676 asmlinkage void space_switch_exception(struct pt_regs * regs, long int_code)
 677 {
 678         siginfo_t info;
 679
 680         /* Set user psw back to home space mode. */
 681         if (regs->psw.mask & PSW_MASK_PSTATE)
 682                 regs->psw.mask |= PSW_ASC_HOME;
 683         /* Send SIGILL. */
 684         info.si_signo = SIGILL;
 685         info.si_errno = 0;
 686         info.si_code = ILL_PRVOPC;
 687         info.si_addr = get_check_address(regs);
 688         do_trap(int_code, SIGILL, "space switch event", regs, &info);
 689 }
 690
 691 asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
 692 {
 693         bust_spinlocks(1);
 694         printk("Kernel stack overflow.\n");
 695         show_regs(regs);
 696         bust_spinlocks(0);
 697         panic("Corrupt kernel stack, can't continue.");
 698 }
 699
 700 /* init is done in lowcore.S and head.S */
 701
 702 void __init trap_init(void)
 703 {
 704         int i;
 705
 706         for (i = 0; i < 128; i++)
 707           pgm_check_table[i] = &default_trap_handler;
 708         pgm_check_table[1] = &illegal_op;
 709         pgm_check_table[2] = &privileged_op;
 710         pgm_check_table[3] = &execute_exception;
 711         pgm_check_table[4] = &do_protection_exception;
 712         pgm_check_table[5] = &addressing_exception;
 713         pgm_check_table[6] = &specification_exception;
 714         pgm_check_table[7] = &data_exception;
 715         pgm_check_table[8] = &overflow_exception;
 716         pgm_check_table[9] = &divide_exception;
 717         pgm_check_table[0x0A] = &overflow_exception;
 718         pgm_check_table[0x0B] = &divide_exception;
 719         pgm_check_table[0x0C] = &hfp_overflow_exception;
 720         pgm_check_table[0x0D] = &hfp_underflow_exception;
 721         pgm_check_table[0x0E] = &hfp_significance_exception;
 722         pgm_check_table[0x0F] = &hfp_divide_exception;
 723         pgm_check_table[0x10] = &do_dat_exception;
 724         pgm_check_table[0x11] = &do_dat_exception;
 725         pgm_check_table[0x12] = &translation_exception;
 726         pgm_check_table[0x13] = &special_op_exception;
 727 #ifdef CONFIG_64BIT
 728         pgm_check_table[0x38] = &do_dat_exception;
 729         pgm_check_table[0x39] = &do_dat_exception;
 730         pgm_check_table[0x3A] = &do_dat_exception;
 731         pgm_check_table[0x3B] = &do_dat_exception;
 732 #endif /* CONFIG_64BIT */
 733         pgm_check_table[0x15] = &operand_exception;
 734         pgm_check_table[0x1C] = &space_switch_exception;
 735         pgm_check_table[0x1D] = &hfp_sqrt_exception;
 736         pgm_check_table[0x40] = &do_monitor_call;
 737
 738         if (MACHINE_IS_VM) {
 739 #ifdef CONFIG_PFAULT
 740                 /*
 741                  * Try to get pfault pseudo page faults going.
 742                  */
 743                 if (register_early_external_interrupt(0x2603, pfault_interrupt,
 744                                                       &ext_int_pfault) != 0)
 745                         panic("Couldn't request external interrupt 0x2603");
 746
 747                 if (pfault_init() == 0)
 748                         return;
 749
 750                 /* Tough luck, no pfault. */
 751                 unregister_early_external_interrupt(0x2603, pfault_interrupt,
 752                                                     &ext_int_pfault);
 753 #endif
 754         }
 755 }