release/src-rt-6.x.4708/linux/linux-2.6.36/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/tracehook.h>
  22 #include <linux/timer.h>
  23 #include <linux/mm.h>
  24 #include <linux/smp.h>
  25 #include <linux/init.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/seq_file.h>
  28 #include <linux/delay.h>
  29 #include <linux/module.h>
  30 #include <linux/kdebug.h>
  31 #include <linux/kallsyms.h>
  32 #include <linux/reboot.h>
  33 #include <linux/kprobes.h>
  34 #include <linux/bug.h>
  35 #include <linux/utsname.h>
  36 #include <asm/system.h>
  37 #include <asm/uaccess.h>
  38 #include <asm/io.h>
  39 #include <asm/atomic.h>
  40 #include <asm/mathemu.h>
  41 #include <asm/cpcmd.h>
  42 #include <asm/s390_ext.h>
  43 #include <asm/lowcore.h>
  44 #include <asm/debug.h>
  45 #include "entry.h"
  46
  47 pgm_check_handler_t *pgm_check_table[128];
  48
  49 int show_unhandled_signals;
  50
  51 extern pgm_check_handler_t do_protection_exception;
  52 extern pgm_check_handler_t do_dat_exception;
  53 extern pgm_check_handler_t do_asce_exception;
  54
  55 #define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
  56
  57 #ifndef CONFIG_64BIT
  58 #define LONG "%08lx "
  59 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
  60 static int kstack_depth_to_print = 12;
  61 #else /* CONFIG_64BIT */
  62 #define LONG "%016lx "
  63 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
  64 static int kstack_depth_to_print = 20;
  65 #endif /* CONFIG_64BIT */
  66
  67 /*
  68  * For show_trace we have tree different stack to consider:
  69  *   - the panic stack which is used if the kernel stack has overflown
  70  *   - the asynchronous interrupt stack (cpu related)
  71  *   - the synchronous kernel stack (process related)
  72  * The stack trace can start at any of the three stack and can potentially
  73  * touch all of them. The order is: panic stack, async stack, sync stack.
  74  */
  75 static unsigned long
  76 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
  77 {
  78         struct stack_frame *sf;
  79         struct pt_regs *regs;
  80
  81         while (1) {
  82                 sp = sp & PSW_ADDR_INSN;
  83                 if (sp < low || sp > high - sizeof(*sf))
  84                         return sp;
  85                 sf = (struct stack_frame *) sp;
  86                 printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
  87                 print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
  88                 /* Follow the backchain. */
  89                 while (1) {
  90                         low = sp;
  91                         sp = sf->back_chain & PSW_ADDR_INSN;
  92                         if (!sp)
  93                                 break;
  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                 }
 100                 /* Zero backchain detected, check for interrupt frame. */
 101                 sp = (unsigned long) (sf + 1);
 102                 if (sp <= low || sp > high - sizeof(*regs))
 103                         return sp;
 104                 regs = (struct pt_regs *) sp;
 105                 printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
 106                 print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
 107                 low = sp;
 108                 sp = regs->gprs[15];
 109         }
 110 }
 111
 112 static void show_trace(struct task_struct *task, unsigned long *stack)
 113 {
 114         register unsigned long __r15 asm ("15");
 115         unsigned long sp;
 116
 117         sp = (unsigned long) stack;
 118         if (!sp)
 119                 sp = task ? task->thread.ksp : __r15;
 120         printk("Call Trace:\n");
 121 #ifdef CONFIG_CHECK_STACK
 122         sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
 123                           S390_lowcore.panic_stack);
 124 #endif
 125         sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
 126                           S390_lowcore.async_stack);
 127         if (task)
 128                 __show_trace(sp, (unsigned long) task_stack_page(task),
 129                              (unsigned long) task_stack_page(task) + THREAD_SIZE);
 130         else
 131                 __show_trace(sp, S390_lowcore.thread_info,
 132                              S390_lowcore.thread_info + THREAD_SIZE);
 133         if (!task)
 134                 task = current;
 135         debug_show_held_locks(task);
 136 }
 137
 138 void show_stack(struct task_struct *task, unsigned long *sp)
 139 {
 140         register unsigned long * __r15 asm ("15");
 141         unsigned long *stack;
 142         int i;
 143
 144         if (!sp)
 145                 stack = task ? (unsigned long *) task->thread.ksp : __r15;
 146         else
 147                 stack = sp;
 148
 149         for (i = 0; i < kstack_depth_to_print; i++) {
 150                 if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
 151                         break;
 152                 if (i && ((i * sizeof (long) % 32) == 0))
 153                         printk("\n       ");
 154                 printk(LONG, *stack++);
 155         }
 156         printk("\n");
 157         show_trace(task, sp);
 158 }
 159
 160 static void show_last_breaking_event(struct pt_regs *regs)
 161 {
 162 #ifdef CONFIG_64BIT
 163         printk("Last Breaking-Event-Address:\n");
 164         printk(" [<%016lx>] ", regs->args[0] & PSW_ADDR_INSN);
 165         print_symbol("%s\n", regs->args[0] & PSW_ADDR_INSN);
 166 #endif
 167 }
 168
 169 /*
 170  * The architecture-independent dump_stack generator
 171  */
 172 void dump_stack(void)
 173 {
 174         printk("CPU: %d %s %s %.*s\n",
 175                task_thread_info(current)->cpu, print_tainted(),
 176                init_utsname()->release,
 177                (int)strcspn(init_utsname()->version, " "),
 178                init_utsname()->version);
 179         printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
 180                current->comm, current->pid, current,
 181                (void *) current->thread.ksp);
 182         show_stack(NULL, NULL);
 183 }
 184 EXPORT_SYMBOL(dump_stack);
 185
 186 static inline int mask_bits(struct pt_regs *regs, unsigned long bits)
 187 {
 188         return (regs->psw.mask & bits) / ((~bits + 1) & bits);
 189 }
 190
 191 void show_registers(struct pt_regs *regs)
 192 {
 193         char *mode;
 194
 195         mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
 196         printk("%s PSW : %p %p",
 197                mode, (void *) regs->psw.mask,
 198                (void *) regs->psw.addr);
 199         print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
 200         printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
 201                "P:%x AS:%x CC:%x PM:%x", mask_bits(regs, PSW_MASK_PER),
 202                mask_bits(regs, PSW_MASK_DAT), mask_bits(regs, PSW_MASK_IO),
 203                mask_bits(regs, PSW_MASK_EXT), mask_bits(regs, PSW_MASK_KEY),
 204                mask_bits(regs, PSW_MASK_MCHECK), mask_bits(regs, PSW_MASK_WAIT),
 205                mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC),
 206                mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM));
 207 #ifdef CONFIG_64BIT
 208         printk(" EA:%x", mask_bits(regs, PSW_BASE_BITS));
 209 #endif
 210         printk("\n%s GPRS: " FOURLONG, mode,
 211                regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
 212         printk("           " FOURLONG,
 213                regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
 214         printk("           " FOURLONG,
 215                regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
 216         printk("           " FOURLONG,
 217                regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
 218
 219         show_code(regs);
 220 }
 221
 222 void show_regs(struct pt_regs *regs)
 223 {
 224         print_modules();
 225         printk("CPU: %d %s %s %.*s\n",
 226                task_thread_info(current)->cpu, print_tainted(),
 227                init_utsname()->release,
 228                (int)strcspn(init_utsname()->version, " "),
 229                init_utsname()->version);
 230         printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
 231                current->comm, current->pid, current,
 232                (void *) current->thread.ksp);
 233         show_registers(regs);
 234         /* Show stack backtrace if pt_regs is from kernel mode */
 235         if (!(regs->psw.mask & PSW_MASK_PSTATE))
 236                 show_trace(NULL, (unsigned long *) regs->gprs[15]);
 237         show_last_breaking_event(regs);
 238 }
 239
 240 /* This is called from fs/proc/array.c */
 241 void task_show_regs(struct seq_file *m, struct task_struct *task)
 242 {
 243         struct pt_regs *regs;
 244
 245         regs = task_pt_regs(task);
 246         seq_printf(m, "task: %p, ksp: %p\n",
 247                        task, (void *)task->thread.ksp);
 248         seq_printf(m, "User PSW : %p %p\n",
 249                        (void *) regs->psw.mask, (void *)regs->psw.addr);
 250
 251         seq_printf(m, "User GPRS: " FOURLONG,
 252                           regs->gprs[0], regs->gprs[1],
 253                           regs->gprs[2], regs->gprs[3]);
 254         seq_printf(m, "           " FOURLONG,
 255                           regs->gprs[4], regs->gprs[5],
 256                           regs->gprs[6], regs->gprs[7]);
 257         seq_printf(m, "           " FOURLONG,
 258                           regs->gprs[8], regs->gprs[9],
 259                           regs->gprs[10], regs->gprs[11]);
 260         seq_printf(m, "           " FOURLONG,
 261                           regs->gprs[12], regs->gprs[13],
 262                           regs->gprs[14], regs->gprs[15]);
 263         seq_printf(m, "User ACRS: %08x %08x %08x %08x\n",
 264                           task->thread.acrs[0], task->thread.acrs[1],
 265                           task->thread.acrs[2], task->thread.acrs[3]);
 266         seq_printf(m, "           %08x %08x %08x %08x\n",
 267                           task->thread.acrs[4], task->thread.acrs[5],
 268                           task->thread.acrs[6], task->thread.acrs[7]);
 269         seq_printf(m, "           %08x %08x %08x %08x\n",
 270                           task->thread.acrs[8], task->thread.acrs[9],
 271                           task->thread.acrs[10], task->thread.acrs[11]);
 272         seq_printf(m, "           %08x %08x %08x %08x\n",
 273                           task->thread.acrs[12], task->thread.acrs[13],
 274                           task->thread.acrs[14], task->thread.acrs[15]);
 275 }
 276
 277 static DEFINE_SPINLOCK(die_lock);
 278
 279 void die(const char * str, struct pt_regs * regs, long err)
 280 {
 281         static int die_counter;
 282
 283         oops_enter();
 284         debug_stop_all();
 285         console_verbose();
 286         spin_lock_irq(&die_lock);
 287         bust_spinlocks(1);
 288         printk("%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
 289 #ifdef CONFIG_PREEMPT
 290         printk("PREEMPT ");
 291 #endif
 292 #ifdef CONFIG_SMP
 293         printk("SMP ");
 294 #endif
 295 #ifdef CONFIG_DEBUG_PAGEALLOC
 296         printk("DEBUG_PAGEALLOC");
 297 #endif
 298         printk("\n");
 299         notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
 300         show_regs(regs);
 301         bust_spinlocks(0);
 302         add_taint(TAINT_DIE);
 303         spin_unlock_irq(&die_lock);
 304         if (in_interrupt())
 305                 panic("Fatal exception in interrupt");
 306         if (panic_on_oops)
 307                 panic("Fatal exception: panic_on_oops");
 308         oops_exit();
 309         do_exit(SIGSEGV);
 310 }
 311
 312 static void inline report_user_fault(struct pt_regs *regs, long int_code,
 313                                      int signr)
 314 {
 315         if ((task_pid_nr(current) > 1) && !show_unhandled_signals)
 316                 return;
 317         if (!unhandled_signal(current, signr))
 318                 return;
 319         if (!printk_ratelimit())
 320                 return;
 321         printk("User process fault: interruption code 0x%lX ", int_code);
 322         print_vma_addr("in ", regs->psw.addr & PSW_ADDR_INSN);
 323         printk("\n");
 324         show_regs(regs);
 325 }
 326
 327 int is_valid_bugaddr(unsigned long addr)
 328 {
 329         return 1;
 330 }
 331
 332 static void __kprobes inline do_trap(long interruption_code, int signr,
 333                                         char *str, struct pt_regs *regs,
 334                                         siginfo_t *info)
 335 {
 336         /*
 337          * We got all needed information from the lowcore and can
 338          * now safely switch on interrupts.
 339          */
 340         if (regs->psw.mask & PSW_MASK_PSTATE)
 341                 local_irq_enable();
 342
 343         if (notify_die(DIE_TRAP, str, regs, interruption_code,
 344                                 interruption_code, signr) == NOTIFY_STOP)
 345                 return;
 346
 347         if (regs->psw.mask & PSW_MASK_PSTATE) {
 348                 struct task_struct *tsk = current;
 349
 350                 tsk->thread.trap_no = interruption_code & 0xffff;
 351                 force_sig_info(signr, info, tsk);
 352                 report_user_fault(regs, interruption_code, signr);
 353         } else {
 354                 const struct exception_table_entry *fixup;
 355                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
 356                 if (fixup)
 357                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
 358                 else {
 359                         enum bug_trap_type btt;
 360
 361                         btt = report_bug(regs->psw.addr & PSW_ADDR_INSN, regs);
 362                         if (btt == BUG_TRAP_TYPE_WARN)
 363                                 return;
 364                         die(str, regs, interruption_code);
 365                 }
 366         }
 367 }
 368
 369 static inline void __user *get_check_address(struct pt_regs *regs)
 370 {
 371         return (void __user *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
 372 }
 373
 374 void __kprobes do_single_step(struct pt_regs *regs)
 375 {
 376         if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0,
 377                                         SIGTRAP) == NOTIFY_STOP){
 378                 return;
 379         }
 380         if (tracehook_consider_fatal_signal(current, SIGTRAP))
 381                 force_sig(SIGTRAP, current);
 382 }
 383
 384 static void default_trap_handler(struct pt_regs * regs, long interruption_code)
 385 {
 386         if (regs->psw.mask & PSW_MASK_PSTATE) {
 387                 local_irq_enable();
 388                 report_user_fault(regs, interruption_code, SIGSEGV);
 389                 do_exit(SIGSEGV);
 390         } else
 391                 die("Unknown program exception", regs, interruption_code);
 392 }
 393
 394 #define DO_ERROR_INFO(signr, str, name, sicode, siaddr) \
 395 static void name(struct pt_regs * regs, long interruption_code) \
 396 { \
 397         siginfo_t info; \
 398         info.si_signo = signr; \
 399         info.si_errno = 0; \
 400         info.si_code = sicode; \
 401         info.si_addr = siaddr; \
 402         do_trap(interruption_code, signr, str, regs, &info); \
 403 }
 404
 405 DO_ERROR_INFO(SIGILL, "addressing exception", addressing_exception,
 406               ILL_ILLADR, get_check_address(regs))
 407 DO_ERROR_INFO(SIGILL,  "execute exception", execute_exception,
 408               ILL_ILLOPN, get_check_address(regs))
 409 DO_ERROR_INFO(SIGFPE,  "fixpoint divide exception", divide_exception,
 410               FPE_INTDIV, get_check_address(regs))
 411 DO_ERROR_INFO(SIGFPE,  "fixpoint overflow exception", overflow_exception,
 412               FPE_INTOVF, get_check_address(regs))
 413 DO_ERROR_INFO(SIGFPE,  "HFP overflow exception", hfp_overflow_exception,
 414               FPE_FLTOVF, get_check_address(regs))
 415 DO_ERROR_INFO(SIGFPE,  "HFP underflow exception", hfp_underflow_exception,
 416               FPE_FLTUND, get_check_address(regs))
 417 DO_ERROR_INFO(SIGFPE,  "HFP significance exception", hfp_significance_exception,
 418               FPE_FLTRES, get_check_address(regs))
 419 DO_ERROR_INFO(SIGFPE,  "HFP divide exception", hfp_divide_exception,
 420               FPE_FLTDIV, get_check_address(regs))
 421 DO_ERROR_INFO(SIGFPE,  "HFP square root exception", hfp_sqrt_exception,
 422               FPE_FLTINV, get_check_address(regs))
 423 DO_ERROR_INFO(SIGILL,  "operand exception", operand_exception,
 424               ILL_ILLOPN, get_check_address(regs))
 425 DO_ERROR_INFO(SIGILL,  "privileged operation", privileged_op,
 426               ILL_PRVOPC, get_check_address(regs))
 427 DO_ERROR_INFO(SIGILL,  "special operation exception", special_op_exception,
 428               ILL_ILLOPN, get_check_address(regs))
 429 DO_ERROR_INFO(SIGILL,  "translation exception", translation_exception,
 430               ILL_ILLOPN, get_check_address(regs))
 431
 432 static inline void
 433 do_fp_trap(struct pt_regs *regs, void __user *location,
 434            int fpc, long interruption_code)
 435 {
 436         siginfo_t si;
 437
 438         si.si_signo = SIGFPE;
 439         si.si_errno = 0;
 440         si.si_addr = location;
 441         si.si_code = 0;
 442         /* FPC[2] is Data Exception Code */
 443         if ((fpc & 0x00000300) == 0) {
 444                 /* bits 6 and 7 of DXC are 0 iff IEEE exception */
 445                 if (fpc & 0x8000) /* invalid fp operation */
 446                         si.si_code = FPE_FLTINV;
 447                 else if (fpc & 0x4000) /* div by 0 */
 448                         si.si_code = FPE_FLTDIV;
 449                 else if (fpc & 0x2000) /* overflow */
 450                         si.si_code = FPE_FLTOVF;
 451                 else if (fpc & 0x1000) /* underflow */
 452                         si.si_code = FPE_FLTUND;
 453                 else if (fpc & 0x0800) /* inexact */
 454                         si.si_code = FPE_FLTRES;
 455         }
 456         current->thread.ieee_instruction_pointer = (addr_t) location;
 457         do_trap(interruption_code, SIGFPE,
 458                 "floating point exception", regs, &si);
 459 }
 460
 461 static void illegal_op(struct pt_regs * regs, long interruption_code)
 462 {
 463         siginfo_t info;
 464         __u8 opcode[6];
 465         __u16 __user *location;
 466         int signal = 0;
 467
 468         location = get_check_address(regs);
 469
 470         /*
 471          * We got all needed information from the lowcore and can
 472          * now safely switch on interrupts.
 473          */
 474         if (regs->psw.mask & PSW_MASK_PSTATE)
 475                 local_irq_enable();
 476
 477         if (regs->psw.mask & PSW_MASK_PSTATE) {
 478                 if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
 479                         return;
 480                 if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
 481                         if (tracehook_consider_fatal_signal(current, SIGTRAP))
 482                                 force_sig(SIGTRAP, current);
 483                         else
 484                                 signal = SIGILL;
 485 #ifdef CONFIG_MATHEMU
 486                 } else if (opcode[0] == 0xb3) {
 487                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 488                                 return;
 489                         signal = math_emu_b3(opcode, regs);
 490                 } else if (opcode[0] == 0xed) {
 491                         if (get_user(*((__u32 *) (opcode+2)),
 492                                      (__u32 __user *)(location+1)))
 493                                 return;
 494                         signal = math_emu_ed(opcode, regs);
 495                 } else if (*((__u16 *) opcode) == 0xb299) {
 496                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 497                                 return;
 498                         signal = math_emu_srnm(opcode, regs);
 499                 } else if (*((__u16 *) opcode) == 0xb29c) {
 500                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 501                                 return;
 502                         signal = math_emu_stfpc(opcode, regs);
 503                 } else if (*((__u16 *) opcode) == 0xb29d) {
 504                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 505                                 return;
 506                         signal = math_emu_lfpc(opcode, regs);
 507 #endif
 508                 } else
 509                         signal = SIGILL;
 510         } else {
 511                 /*
 512                  * If we get an illegal op in kernel mode, send it through the
 513                  * kprobes notifier. If kprobes doesn't pick it up, SIGILL
 514                  */
 515                 if (notify_die(DIE_BPT, "bpt", regs, interruption_code,
 516                                3, SIGTRAP) != NOTIFY_STOP)
 517                         signal = SIGILL;
 518         }
 519
 520 #ifdef CONFIG_MATHEMU
 521         if (signal == SIGFPE)
 522                 do_fp_trap(regs, location,
 523                            current->thread.fp_regs.fpc, interruption_code);
 524         else if (signal == SIGSEGV) {
 525                 info.si_signo = signal;
 526                 info.si_errno = 0;
 527                 info.si_code = SEGV_MAPERR;
 528                 info.si_addr = (void __user *) location;
 529                 do_trap(interruption_code, signal,
 530                         "user address fault", regs, &info);
 531         } else
 532 #endif
 533         if (signal) {
 534                 info.si_signo = signal;
 535                 info.si_errno = 0;
 536                 info.si_code = ILL_ILLOPC;
 537                 info.si_addr = (void __user *) location;
 538                 do_trap(interruption_code, signal,
 539                         "illegal operation", regs, &info);
 540         }
 541 }
 542
 543
 544 #ifdef CONFIG_MATHEMU
 545 asmlinkage void
 546 specification_exception(struct pt_regs * regs, long interruption_code)
 547 {
 548         __u8 opcode[6];
 549         __u16 __user *location = NULL;
 550         int signal = 0;
 551
 552         location = (__u16 __user *) get_check_address(regs);
 553
 554         /*
 555          * We got all needed information from the lowcore and can
 556          * now safely switch on interrupts.
 557          */
 558         if (regs->psw.mask & PSW_MASK_PSTATE)
 559                 local_irq_enable();
 560
 561         if (regs->psw.mask & PSW_MASK_PSTATE) {
 562                 get_user(*((__u16 *) opcode), location);
 563                 switch (opcode[0]) {
 564                 case 0x28: /* LDR Rx,Ry   */
 565                         signal = math_emu_ldr(opcode);
 566                         break;
 567                 case 0x38: /* LER Rx,Ry   */
 568                         signal = math_emu_ler(opcode);
 569                         break;
 570                 case 0x60: /* STD R,D(X,B) */
 571                         get_user(*((__u16 *) (opcode+2)), location+1);
 572                         signal = math_emu_std(opcode, regs);
 573                         break;
 574                 case 0x68: /* LD R,D(X,B) */
 575                         get_user(*((__u16 *) (opcode+2)), location+1);
 576                         signal = math_emu_ld(opcode, regs);
 577                         break;
 578                 case 0x70: /* STE R,D(X,B) */
 579                         get_user(*((__u16 *) (opcode+2)), location+1);
 580                         signal = math_emu_ste(opcode, regs);
 581                         break;
 582                 case 0x78: /* LE R,D(X,B) */
 583                         get_user(*((__u16 *) (opcode+2)), location+1);
 584                         signal = math_emu_le(opcode, regs);
 585                         break;
 586                 default:
 587                         signal = SIGILL;
 588                         break;
 589                 }
 590         } else
 591                 signal = SIGILL;
 592
 593         if (signal == SIGFPE)
 594                 do_fp_trap(regs, location,
 595                            current->thread.fp_regs.fpc, interruption_code);
 596         else if (signal) {
 597                 siginfo_t info;
 598                 info.si_signo = signal;
 599                 info.si_errno = 0;
 600                 info.si_code = ILL_ILLOPN;
 601                 info.si_addr = location;
 602                 do_trap(interruption_code, signal,
 603                         "specification exception", regs, &info);
 604         }
 605 }
 606 #else
 607 DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
 608               ILL_ILLOPN, get_check_address(regs));
 609 #endif
 610
 611 static void data_exception(struct pt_regs * regs, long interruption_code)
 612 {
 613         __u16 __user *location;
 614         int signal = 0;
 615
 616         location = get_check_address(regs);
 617
 618         /*
 619          * We got all needed information from the lowcore and can
 620          * now safely switch on interrupts.
 621          */
 622         if (regs->psw.mask & PSW_MASK_PSTATE)
 623                 local_irq_enable();
 624
 625         if (MACHINE_HAS_IEEE)
 626                 asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
 627
 628 #ifdef CONFIG_MATHEMU
 629         else if (regs->psw.mask & PSW_MASK_PSTATE) {
 630                 __u8 opcode[6];
 631                 get_user(*((__u16 *) opcode), location);
 632                 switch (opcode[0]) {
 633                 case 0x28: /* LDR Rx,Ry   */
 634                         signal = math_emu_ldr(opcode);
 635                         break;
 636                 case 0x38: /* LER Rx,Ry   */
 637                         signal = math_emu_ler(opcode);
 638                         break;
 639                 case 0x60: /* STD R,D(X,B) */
 640                         get_user(*((__u16 *) (opcode+2)), location+1);
 641                         signal = math_emu_std(opcode, regs);
 642                         break;
 643                 case 0x68: /* LD R,D(X,B) */
 644                         get_user(*((__u16 *) (opcode+2)), location+1);
 645                         signal = math_emu_ld(opcode, regs);
 646                         break;
 647                 case 0x70: /* STE R,D(X,B) */
 648                         get_user(*((__u16 *) (opcode+2)), location+1);
 649                         signal = math_emu_ste(opcode, regs);
 650                         break;
 651                 case 0x78: /* LE R,D(X,B) */
 652                         get_user(*((__u16 *) (opcode+2)), location+1);
 653                         signal = math_emu_le(opcode, regs);
 654                         break;
 655                 case 0xb3:
 656                         get_user(*((__u16 *) (opcode+2)), location+1);
 657                         signal = math_emu_b3(opcode, regs);
 658                         break;
 659                 case 0xed:
 660                         get_user(*((__u32 *) (opcode+2)),
 661                                  (__u32 __user *)(location+1));
 662                         signal = math_emu_ed(opcode, regs);
 663                         break;
 664                 case 0xb2:
 665                         if (opcode[1] == 0x99) {
 666                                 get_user(*((__u16 *) (opcode+2)), location+1);
 667                                 signal = math_emu_srnm(opcode, regs);
 668                         } else if (opcode[1] == 0x9c) {
 669                                 get_user(*((__u16 *) (opcode+2)), location+1);
 670                                 signal = math_emu_stfpc(opcode, regs);
 671                         } else if (opcode[1] == 0x9d) {
 672                                 get_user(*((__u16 *) (opcode+2)), location+1);
 673                                 signal = math_emu_lfpc(opcode, regs);
 674                         } else
 675                                 signal = SIGILL;
 676                         break;
 677                 default:
 678                         signal = SIGILL;
 679                         break;
 680                 }
 681         }
 682 #endif
 683         if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
 684                 signal = SIGFPE;
 685         else
 686                 signal = SIGILL;
 687         if (signal == SIGFPE)
 688                 do_fp_trap(regs, location,
 689                            current->thread.fp_regs.fpc, interruption_code);
 690         else if (signal) {
 691                 siginfo_t info;
 692                 info.si_signo = signal;
 693                 info.si_errno = 0;
 694                 info.si_code = ILL_ILLOPN;
 695                 info.si_addr = location;
 696                 do_trap(interruption_code, signal,
 697                         "data exception", regs, &info);
 698         }
 699 }
 700
 701 static void space_switch_exception(struct pt_regs * regs, long int_code)
 702 {
 703         siginfo_t info;
 704
 705         /* Set user psw back to home space mode. */
 706         if (regs->psw.mask & PSW_MASK_PSTATE)
 707                 regs->psw.mask |= PSW_ASC_HOME;
 708         /* Send SIGILL. */
 709         info.si_signo = SIGILL;
 710         info.si_errno = 0;
 711         info.si_code = ILL_PRVOPC;
 712         info.si_addr = get_check_address(regs);
 713         do_trap(int_code, SIGILL, "space switch event", regs, &info);
 714 }
 715
 716 asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
 717 {
 718         bust_spinlocks(1);
 719         printk("Kernel stack overflow.\n");
 720         show_regs(regs);
 721         bust_spinlocks(0);
 722         panic("Corrupt kernel stack, can't continue.");
 723 }
 724
 725 /* init is done in lowcore.S and head.S */
 726
 727 void __init trap_init(void)
 728 {
 729         int i;
 730
 731         for (i = 0; i < 128; i++)
 732           pgm_check_table[i] = &default_trap_handler;
 733         pgm_check_table[1] = &illegal_op;
 734         pgm_check_table[2] = &privileged_op;
 735         pgm_check_table[3] = &execute_exception;
 736         pgm_check_table[4] = &do_protection_exception;
 737         pgm_check_table[5] = &addressing_exception;
 738         pgm_check_table[6] = &specification_exception;
 739         pgm_check_table[7] = &data_exception;
 740         pgm_check_table[8] = &overflow_exception;
 741         pgm_check_table[9] = &divide_exception;
 742         pgm_check_table[0x0A] = &overflow_exception;
 743         pgm_check_table[0x0B] = &divide_exception;
 744         pgm_check_table[0x0C] = &hfp_overflow_exception;
 745         pgm_check_table[0x0D] = &hfp_underflow_exception;
 746         pgm_check_table[0x0E] = &hfp_significance_exception;
 747         pgm_check_table[0x0F] = &hfp_divide_exception;
 748         pgm_check_table[0x10] = &do_dat_exception;
 749         pgm_check_table[0x11] = &do_dat_exception;
 750         pgm_check_table[0x12] = &translation_exception;
 751         pgm_check_table[0x13] = &special_op_exception;
 752 #ifdef CONFIG_64BIT
 753         pgm_check_table[0x38] = &do_asce_exception;
 754         pgm_check_table[0x39] = &do_dat_exception;
 755         pgm_check_table[0x3A] = &do_dat_exception;
 756         pgm_check_table[0x3B] = &do_dat_exception;
 757 #endif /* CONFIG_64BIT */
 758         pgm_check_table[0x15] = &operand_exception;
 759         pgm_check_table[0x1C] = &space_switch_exception;
 760         pgm_check_table[0x1D] = &hfp_sqrt_exception;
 761         pfault_irq_init();
 762 }