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 inline void __kprobes do_trap(long pgm_int_code, int signr, char *str,
 333                                      struct pt_regs *regs, siginfo_t *info)
 334 {
 335         if (notify_die(DIE_TRAP, str, regs, pgm_int_code,
 336                        pgm_int_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 = pgm_int_code & 0xffff;
 343                 force_sig_info(signr, info, tsk);
 344                 report_user_fault(regs, pgm_int_code, signr);
 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                         enum bug_trap_type btt;
 352
 353                         btt = report_bug(regs->psw.addr & PSW_ADDR_INSN, regs);
 354                         if (btt == BUG_TRAP_TYPE_WARN)
 355                                 return;
 356                         die(str, regs, pgm_int_code);
 357                 }
 358         }
 359 }
 360
 361 static inline void __user *get_psw_address(struct pt_regs *regs,
 362                                            long pgm_int_code)
 363 {
 364         return (void __user *)
 365                 ((regs->psw.addr - (pgm_int_code >> 16)) & PSW_ADDR_INSN);
 366 }
 367
 368 void __kprobes do_per_trap(struct pt_regs *regs)
 369 {
 370         if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
 371                 return;
 372         if (tracehook_consider_fatal_signal(current, SIGTRAP))
 373                 force_sig(SIGTRAP, current);
 374 }
 375
 376 static void default_trap_handler(struct pt_regs *regs, long pgm_int_code,
 377                                  unsigned long trans_exc_code)
 378 {
 379         if (regs->psw.mask & PSW_MASK_PSTATE) {
 380                 report_user_fault(regs, pgm_int_code, SIGSEGV);
 381                 do_exit(SIGSEGV);
 382         } else
 383                 die("Unknown program exception", regs, pgm_int_code);
 384 }
 385
 386 #define DO_ERROR_INFO(name, signr, sicode, str) \
 387 static void name(struct pt_regs *regs, long pgm_int_code, \
 388                  unsigned long trans_exc_code) \
 389 { \
 390         siginfo_t info; \
 391         info.si_signo = signr; \
 392         info.si_errno = 0; \
 393         info.si_code = sicode; \
 394         info.si_addr = get_psw_address(regs, pgm_int_code); \
 395         do_trap(pgm_int_code, signr, str, regs, &info);     \
 396 }
 397
 398 DO_ERROR_INFO(addressing_exception, SIGILL, ILL_ILLADR,
 399               "addressing exception")
 400 DO_ERROR_INFO(execute_exception, SIGILL, ILL_ILLOPN,
 401               "execute exception")
 402 DO_ERROR_INFO(divide_exception, SIGFPE, FPE_INTDIV,
 403               "fixpoint divide exception")
 404 DO_ERROR_INFO(overflow_exception, SIGFPE, FPE_INTOVF,
 405               "fixpoint overflow exception")
 406 DO_ERROR_INFO(hfp_overflow_exception, SIGFPE, FPE_FLTOVF,
 407               "HFP overflow exception")
 408 DO_ERROR_INFO(hfp_underflow_exception, SIGFPE, FPE_FLTUND,
 409               "HFP underflow exception")
 410 DO_ERROR_INFO(hfp_significance_exception, SIGFPE, FPE_FLTRES,
 411               "HFP significance exception")
 412 DO_ERROR_INFO(hfp_divide_exception, SIGFPE, FPE_FLTDIV,
 413               "HFP divide exception")
 414 DO_ERROR_INFO(hfp_sqrt_exception, SIGFPE, FPE_FLTINV,
 415               "HFP square root exception")
 416 DO_ERROR_INFO(operand_exception, SIGILL, ILL_ILLOPN,
 417               "operand exception")
 418 DO_ERROR_INFO(privileged_op, SIGILL, ILL_PRVOPC,
 419               "privileged operation")
 420 DO_ERROR_INFO(special_op_exception, SIGILL, ILL_ILLOPN,
 421               "special operation exception")
 422 DO_ERROR_INFO(translation_exception, SIGILL, ILL_ILLOPN,
 423               "translation exception")
 424
 425 static inline void do_fp_trap(struct pt_regs *regs, void __user *location,
 426                               int fpc, long pgm_int_code)
 427 {
 428         siginfo_t si;
 429
 430         si.si_signo = SIGFPE;
 431         si.si_errno = 0;
 432         si.si_addr = location;
 433         si.si_code = 0;
 434         /* FPC[2] is Data Exception Code */
 435         if ((fpc & 0x00000300) == 0) {
 436                 /* bits 6 and 7 of DXC are 0 iff IEEE exception */
 437                 if (fpc & 0x8000) /* invalid fp operation */
 438                         si.si_code = FPE_FLTINV;
 439                 else if (fpc & 0x4000) /* div by 0 */
 440                         si.si_code = FPE_FLTDIV;
 441                 else if (fpc & 0x2000) /* overflow */
 442                         si.si_code = FPE_FLTOVF;
 443                 else if (fpc & 0x1000) /* underflow */
 444                         si.si_code = FPE_FLTUND;
 445                 else if (fpc & 0x0800) /* inexact */
 446                         si.si_code = FPE_FLTRES;
 447         }
 448         do_trap(pgm_int_code, SIGFPE,
 449                 "floating point exception", regs, &si);
 450 }
 451
 452 static void __kprobes illegal_op(struct pt_regs *regs, long pgm_int_code,
 453                                  unsigned long trans_exc_code)
 454 {
 455         siginfo_t info;
 456         __u8 opcode[6];
 457         __u16 __user *location;
 458         int signal = 0;
 459
 460         location = get_psw_address(regs, pgm_int_code);
 461
 462         if (regs->psw.mask & PSW_MASK_PSTATE) {
 463                 if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
 464                         return;
 465                 if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
 466                         if (tracehook_consider_fatal_signal(current, SIGTRAP))
 467                                 force_sig(SIGTRAP, current);
 468                         else
 469                                 signal = SIGILL;
 470 #ifdef CONFIG_MATHEMU
 471                 } else if (opcode[0] == 0xb3) {
 472                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 473                                 return;
 474                         signal = math_emu_b3(opcode, regs);
 475                 } else if (opcode[0] == 0xed) {
 476                         if (get_user(*((__u32 *) (opcode+2)),
 477                                      (__u32 __user *)(location+1)))
 478                                 return;
 479                         signal = math_emu_ed(opcode, regs);
 480                 } else if (*((__u16 *) opcode) == 0xb299) {
 481                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 482                                 return;
 483                         signal = math_emu_srnm(opcode, regs);
 484                 } else if (*((__u16 *) opcode) == 0xb29c) {
 485                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 486                                 return;
 487                         signal = math_emu_stfpc(opcode, regs);
 488                 } else if (*((__u16 *) opcode) == 0xb29d) {
 489                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 490                                 return;
 491                         signal = math_emu_lfpc(opcode, regs);
 492 #endif
 493                 } else
 494                         signal = SIGILL;
 495         } else {
 496                 /*
 497                  * If we get an illegal op in kernel mode, send it through the
 498                  * kprobes notifier. If kprobes doesn't pick it up, SIGILL
 499                  */
 500                 if (notify_die(DIE_BPT, "bpt", regs, pgm_int_code,
 501                                3, SIGTRAP) != NOTIFY_STOP)
 502                         signal = SIGILL;
 503         }
 504
 505 #ifdef CONFIG_MATHEMU
 506         if (signal == SIGFPE)
 507                 do_fp_trap(regs, location,
 508                            current->thread.fp_regs.fpc, pgm_int_code);
 509         else if (signal == SIGSEGV) {
 510                 info.si_signo = signal;
 511                 info.si_errno = 0;
 512                 info.si_code = SEGV_MAPERR;
 513                 info.si_addr = (void __user *) location;
 514                 do_trap(pgm_int_code, signal,
 515                         "user address fault", regs, &info);
 516         } else
 517 #endif
 518         if (signal) {
 519                 info.si_signo = signal;
 520                 info.si_errno = 0;
 521                 info.si_code = ILL_ILLOPC;
 522                 info.si_addr = (void __user *) location;
 523                 do_trap(pgm_int_code, signal,
 524                         "illegal operation", regs, &info);
 525         }
 526 }
 527
 528
 529 #ifdef CONFIG_MATHEMU
 530 asmlinkage void specification_exception(struct pt_regs *regs,
 531                                         long pgm_int_code,
 532                                         unsigned long trans_exc_code)
 533 {
 534         __u8 opcode[6];
 535         __u16 __user *location = NULL;
 536         int signal = 0;
 537
 538         location = (__u16 __user *) get_psw_address(regs, pgm_int_code);
 539
 540         if (regs->psw.mask & PSW_MASK_PSTATE) {
 541                 get_user(*((__u16 *) opcode), location);
 542                 switch (opcode[0]) {
 543                 case 0x28: /* LDR Rx,Ry   */
 544                         signal = math_emu_ldr(opcode);
 545                         break;
 546                 case 0x38: /* LER Rx,Ry   */
 547                         signal = math_emu_ler(opcode);
 548                         break;
 549                 case 0x60: /* STD R,D(X,B) */
 550                         get_user(*((__u16 *) (opcode+2)), location+1);
 551                         signal = math_emu_std(opcode, regs);
 552                         break;
 553                 case 0x68: /* LD R,D(X,B) */
 554                         get_user(*((__u16 *) (opcode+2)), location+1);
 555                         signal = math_emu_ld(opcode, regs);
 556                         break;
 557                 case 0x70: /* STE R,D(X,B) */
 558                         get_user(*((__u16 *) (opcode+2)), location+1);
 559                         signal = math_emu_ste(opcode, regs);
 560                         break;
 561                 case 0x78: /* LE R,D(X,B) */
 562                         get_user(*((__u16 *) (opcode+2)), location+1);
 563                         signal = math_emu_le(opcode, regs);
 564                         break;
 565                 default:
 566                         signal = SIGILL;
 567                         break;
 568                 }
 569         } else
 570                 signal = SIGILL;
 571
 572         if (signal == SIGFPE)
 573                 do_fp_trap(regs, location,
 574                            current->thread.fp_regs.fpc, pgm_int_code);
 575         else if (signal) {
 576                 siginfo_t info;
 577                 info.si_signo = signal;
 578                 info.si_errno = 0;
 579                 info.si_code = ILL_ILLOPN;
 580                 info.si_addr = location;
 581                 do_trap(pgm_int_code, signal,
 582                         "specification exception", regs, &info);
 583         }
 584 }
 585 #else
 586 DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
 587               "specification exception");
 588 #endif
 589
 590 static void data_exception(struct pt_regs *regs, long pgm_int_code,
 591                            unsigned long trans_exc_code)
 592 {
 593         __u16 __user *location;
 594         int signal = 0;
 595
 596         location = get_psw_address(regs, pgm_int_code);
 597
 598         if (MACHINE_HAS_IEEE)
 599                 asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
 600
 601 #ifdef CONFIG_MATHEMU
 602         else if (regs->psw.mask & PSW_MASK_PSTATE) {
 603                 __u8 opcode[6];
 604                 get_user(*((__u16 *) opcode), location);
 605                 switch (opcode[0]) {
 606                 case 0x28: /* LDR Rx,Ry   */
 607                         signal = math_emu_ldr(opcode);
 608                         break;
 609                 case 0x38: /* LER Rx,Ry   */
 610                         signal = math_emu_ler(opcode);
 611                         break;
 612                 case 0x60: /* STD R,D(X,B) */
 613                         get_user(*((__u16 *) (opcode+2)), location+1);
 614                         signal = math_emu_std(opcode, regs);
 615                         break;
 616                 case 0x68: /* LD R,D(X,B) */
 617                         get_user(*((__u16 *) (opcode+2)), location+1);
 618                         signal = math_emu_ld(opcode, regs);
 619                         break;
 620                 case 0x70: /* STE R,D(X,B) */
 621                         get_user(*((__u16 *) (opcode+2)), location+1);
 622                         signal = math_emu_ste(opcode, regs);
 623                         break;
 624                 case 0x78: /* LE R,D(X,B) */
 625                         get_user(*((__u16 *) (opcode+2)), location+1);
 626                         signal = math_emu_le(opcode, regs);
 627                         break;
 628                 case 0xb3:
 629                         get_user(*((__u16 *) (opcode+2)), location+1);
 630                         signal = math_emu_b3(opcode, regs);
 631                         break;
 632                 case 0xed:
 633                         get_user(*((__u32 *) (opcode+2)),
 634                                  (__u32 __user *)(location+1));
 635                         signal = math_emu_ed(opcode, regs);
 636                         break;
 637                 case 0xb2:
 638                         if (opcode[1] == 0x99) {
 639                                 get_user(*((__u16 *) (opcode+2)), location+1);
 640                                 signal = math_emu_srnm(opcode, regs);
 641                         } else if (opcode[1] == 0x9c) {
 642                                 get_user(*((__u16 *) (opcode+2)), location+1);
 643                                 signal = math_emu_stfpc(opcode, regs);
 644                         } else if (opcode[1] == 0x9d) {
 645                                 get_user(*((__u16 *) (opcode+2)), location+1);
 646                                 signal = math_emu_lfpc(opcode, regs);
 647                         } else
 648                                 signal = SIGILL;
 649                         break;
 650                 default:
 651                         signal = SIGILL;
 652                         break;
 653                 }
 654         }
 655 #endif
 656         if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
 657                 signal = SIGFPE;
 658         else
 659                 signal = SIGILL;
 660         if (signal == SIGFPE)
 661                 do_fp_trap(regs, location,
 662                            current->thread.fp_regs.fpc, pgm_int_code);
 663         else if (signal) {
 664                 siginfo_t info;
 665                 info.si_signo = signal;
 666                 info.si_errno = 0;
 667                 info.si_code = ILL_ILLOPN;
 668                 info.si_addr = location;
 669                 do_trap(pgm_int_code, signal, "data exception", regs, &info);
 670         }
 671 }
 672
 673 static void space_switch_exception(struct pt_regs *regs, long pgm_int_code,
 674                                    unsigned long trans_exc_code)
 675 {
 676         siginfo_t info;
 677
 678         /* Set user psw back to home space mode. */
 679         if (regs->psw.mask & PSW_MASK_PSTATE)
 680                 regs->psw.mask |= PSW_ASC_HOME;
 681         /* Send SIGILL. */
 682         info.si_signo = SIGILL;
 683         info.si_errno = 0;
 684         info.si_code = ILL_PRVOPC;
 685         info.si_addr = get_psw_address(regs, pgm_int_code);
 686         do_trap(pgm_int_code, SIGILL, "space switch event", regs, &info);
 687 }
 688
 689 asmlinkage void __kprobes kernel_stack_overflow(struct pt_regs * regs)
 690 {
 691         bust_spinlocks(1);
 692         printk("Kernel stack overflow.\n");
 693         show_regs(regs);
 694         bust_spinlocks(0);
 695         panic("Corrupt kernel stack, can't continue.");
 696 }
 697
 698 /* init is done in lowcore.S and head.S */
 699
 700 void __init trap_init(void)
 701 {
 702         int i;
 703
 704         for (i = 0; i < 128; i++)
 705           pgm_check_table[i] = &default_trap_handler;
 706         pgm_check_table[1] = &illegal_op;
 707         pgm_check_table[2] = &privileged_op;
 708         pgm_check_table[3] = &execute_exception;
 709         pgm_check_table[4] = &do_protection_exception;
 710         pgm_check_table[5] = &addressing_exception;
 711         pgm_check_table[6] = &specification_exception;
 712         pgm_check_table[7] = &data_exception;
 713         pgm_check_table[8] = &overflow_exception;
 714         pgm_check_table[9] = &divide_exception;
 715         pgm_check_table[0x0A] = &overflow_exception;
 716         pgm_check_table[0x0B] = &divide_exception;
 717         pgm_check_table[0x0C] = &hfp_overflow_exception;
 718         pgm_check_table[0x0D] = &hfp_underflow_exception;
 719         pgm_check_table[0x0E] = &hfp_significance_exception;
 720         pgm_check_table[0x0F] = &hfp_divide_exception;
 721         pgm_check_table[0x10] = &do_dat_exception;
 722         pgm_check_table[0x11] = &do_dat_exception;
 723         pgm_check_table[0x12] = &translation_exception;
 724         pgm_check_table[0x13] = &special_op_exception;
 725 #ifdef CONFIG_64BIT
 726         pgm_check_table[0x38] = &do_asce_exception;
 727         pgm_check_table[0x39] = &do_dat_exception;
 728         pgm_check_table[0x3A] = &do_dat_exception;
 729         pgm_check_table[0x3B] = &do_dat_exception;
 730 #endif /* CONFIG_64BIT */
 731         pgm_check_table[0x15] = &operand_exception;
 732         pgm_check_table[0x1C] = &space_switch_exception;
 733         pgm_check_table[0x1D] = &hfp_sqrt_exception;
 734         /* Enable machine checks early. */
 735         local_mcck_enable();
 736 }