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