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/delay.h>
  28 #include <linux/module.h>
  29 #include <linux/kdebug.h>
  30 #include <linux/kallsyms.h>
  31 #include <linux/reboot.h>
  32 #include <linux/kprobes.h>
  33 #include <linux/bug.h>
  34 #include <asm/system.h>
  35 #include <asm/uaccess.h>
  36 #include <asm/io.h>
  37 #include <asm/atomic.h>
  38 #include <asm/mathemu.h>
  39 #include <asm/cpcmd.h>
  40 #include <asm/s390_ext.h>
  41 #include <asm/lowcore.h>
  42 #include <asm/debug.h>
  43
  44 /* Called from entry.S only */
  45 extern void handle_per_exception(struct pt_regs *regs);
  46
  47 typedef void pgm_check_handler_t(struct pt_regs *, long);
  48 pgm_check_handler_t *pgm_check_table[128];
  49
  50 #ifdef CONFIG_SYSCTL
  51 #ifdef CONFIG_PROCESS_DEBUG
  52 int sysctl_userprocess_debug = 1;
  53 #else
  54 int sysctl_userprocess_debug = 0;
  55 #endif
  56 #endif
  57
  58 extern pgm_check_handler_t do_protection_exception;
  59 extern pgm_check_handler_t do_dat_exception;
  60 extern pgm_check_handler_t do_monitor_call;
  61
  62 #define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
  63
  64 #ifndef CONFIG_64BIT
  65 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
  66 static int kstack_depth_to_print = 12;
  67 #else /* CONFIG_64BIT */
  68 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
  69 static int kstack_depth_to_print = 20;
  70 #endif /* CONFIG_64BIT */
  71
  72 /*
  73  * For show_trace we have tree different stack to consider:
  74  *   - the panic stack which is used if the kernel stack has overflown
  75  *   - the asynchronous interrupt stack (cpu related)
  76  *   - the synchronous kernel stack (process related)
  77  * The stack trace can start at any of the three stack and can potentially
  78  * touch all of them. The order is: panic stack, async stack, sync stack.
  79  */
  80 static unsigned long
  81 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
  82 {
  83         struct stack_frame *sf;
  84         struct pt_regs *regs;
  85
  86         while (1) {
  87                 sp = sp & PSW_ADDR_INSN;
  88                 if (sp < low || sp > high - sizeof(*sf))
  89                         return sp;
  90                 sf = (struct stack_frame *) sp;
  91                 printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
  92                 print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
  93                 /* Follow the backchain. */
  94                 while (1) {
  95                         low = sp;
  96                         sp = sf->back_chain & PSW_ADDR_INSN;
  97                         if (!sp)
  98                                 break;
  99                         if (sp <= low || sp > high - sizeof(*sf))
 100                                 return sp;
 101                         sf = (struct stack_frame *) sp;
 102                         printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
 103                         print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
 104                 }
 105                 /* Zero backchain detected, check for interrupt frame. */
 106                 sp = (unsigned long) (sf + 1);
 107                 if (sp <= low || sp > high - sizeof(*regs))
 108                         return sp;
 109                 regs = (struct pt_regs *) sp;
 110                 printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
 111                 print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
 112                 low = sp;
 113                 sp = regs->gprs[15];
 114         }
 115 }
 116
 117 void show_trace(struct task_struct *task, unsigned long *stack)
 118 {
 119         register unsigned long __r15 asm ("15");
 120         unsigned long sp;
 121
 122         sp = (unsigned long) stack;
 123         if (!sp)
 124                 sp = task ? task->thread.ksp : __r15;
 125         printk("Call Trace:\n");
 126 #ifdef CONFIG_CHECK_STACK
 127         sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
 128                           S390_lowcore.panic_stack);
 129 #endif
 130         sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
 131                           S390_lowcore.async_stack);
 132         if (task)
 133                 __show_trace(sp, (unsigned long) task_stack_page(task),
 134                              (unsigned long) task_stack_page(task) + THREAD_SIZE);
 135         else
 136                 __show_trace(sp, S390_lowcore.thread_info,
 137                              S390_lowcore.thread_info + THREAD_SIZE);
 138         printk("\n");
 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("%p ", (void *)*stack++);
 161         }
 162         printk("\n");
 163         show_trace(task, sp);
 164 }
 165
 166 /*
 167  * The architecture-independent dump_stack generator
 168  */
 169 void dump_stack(void)
 170 {
 171         show_stack(NULL, NULL);
 172 }
 173
 174 EXPORT_SYMBOL(dump_stack);
 175
 176 static inline int mask_bits(struct pt_regs *regs, unsigned long bits)
 177 {
 178         return (regs->psw.mask & bits) / ((~bits + 1) & bits);
 179 }
 180
 181 void show_registers(struct pt_regs *regs)
 182 {
 183         char *mode;
 184
 185         mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
 186         printk("%s PSW : %p %p",
 187                mode, (void *) regs->psw.mask,
 188                (void *) regs->psw.addr);
 189         print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
 190         printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
 191                "P:%x AS:%x CC:%x PM:%x", mask_bits(regs, PSW_MASK_PER),
 192                mask_bits(regs, PSW_MASK_DAT), mask_bits(regs, PSW_MASK_IO),
 193                mask_bits(regs, PSW_MASK_EXT), mask_bits(regs, PSW_MASK_KEY),
 194                mask_bits(regs, PSW_MASK_MCHECK), mask_bits(regs, PSW_MASK_WAIT),
 195                mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC),
 196                mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM));
 197 #ifdef CONFIG_64BIT
 198         printk(" EA:%x", mask_bits(regs, PSW_BASE_BITS));
 199 #endif
 200         printk("\n%s GPRS: " FOURLONG, mode,
 201                regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
 202         printk("           " FOURLONG,
 203                regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
 204         printk("           " FOURLONG,
 205                regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
 206         printk("           " FOURLONG,
 207                regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
 208
 209         show_code(regs);
 210 }
 211
 212 /* This is called from fs/proc/array.c */
 213 char *task_show_regs(struct task_struct *task, char *buffer)
 214 {
 215         struct pt_regs *regs;
 216
 217         regs = task_pt_regs(task);
 218         buffer += sprintf(buffer, "task: %p, ksp: %p\n",
 219                        task, (void *)task->thread.ksp);
 220         buffer += sprintf(buffer, "User PSW : %p %p\n",
 221                        (void *) regs->psw.mask, (void *)regs->psw.addr);
 222
 223         buffer += sprintf(buffer, "User GPRS: " FOURLONG,
 224                           regs->gprs[0], regs->gprs[1],
 225                           regs->gprs[2], regs->gprs[3]);
 226         buffer += sprintf(buffer, "           " FOURLONG,
 227                           regs->gprs[4], regs->gprs[5],
 228                           regs->gprs[6], regs->gprs[7]);
 229         buffer += sprintf(buffer, "           " FOURLONG,
 230                           regs->gprs[8], regs->gprs[9],
 231                           regs->gprs[10], regs->gprs[11]);
 232         buffer += sprintf(buffer, "           " FOURLONG,
 233                           regs->gprs[12], regs->gprs[13],
 234                           regs->gprs[14], regs->gprs[15]);
 235         buffer += sprintf(buffer, "User ACRS: %08x %08x %08x %08x\n",
 236                           task->thread.acrs[0], task->thread.acrs[1],
 237                           task->thread.acrs[2], task->thread.acrs[3]);
 238         buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
 239                           task->thread.acrs[4], task->thread.acrs[5],
 240                           task->thread.acrs[6], task->thread.acrs[7]);
 241         buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
 242                           task->thread.acrs[8], task->thread.acrs[9],
 243                           task->thread.acrs[10], task->thread.acrs[11]);
 244         buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
 245                           task->thread.acrs[12], task->thread.acrs[13],
 246                           task->thread.acrs[14], task->thread.acrs[15]);
 247         return buffer;
 248 }
 249
 250 static DEFINE_SPINLOCK(die_lock);
 251
 252 void die(const char * str, struct pt_regs * regs, long err)
 253 {
 254         static int die_counter;
 255
 256         debug_stop_all();
 257         console_verbose();
 258         spin_lock_irq(&die_lock);
 259         bust_spinlocks(1);
 260         printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
 261         show_regs(regs);
 262         bust_spinlocks(0);
 263         spin_unlock_irq(&die_lock);
 264         if (in_interrupt())
 265                 panic("Fatal exception in interrupt");
 266         if (panic_on_oops)
 267                 panic("Fatal exception: panic_on_oops");
 268         do_exit(SIGSEGV);
 269 }
 270
 271 static void inline
 272 report_user_fault(long interruption_code, struct pt_regs *regs)
 273 {
 274 #if defined(CONFIG_SYSCTL)
 275         if (!sysctl_userprocess_debug)
 276                 return;
 277 #endif
 278 #if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG)
 279         printk("User process fault: interruption code 0x%lX\n",
 280                interruption_code);
 281         show_regs(regs);
 282 #endif
 283 }
 284
 285 int is_valid_bugaddr(unsigned long addr)
 286 {
 287         return 1;
 288 }
 289
 290 static void __kprobes inline do_trap(long interruption_code, int signr,
 291                                         char *str, struct pt_regs *regs,
 292                                         siginfo_t *info)
 293 {
 294         /*
 295          * We got all needed information from the lowcore and can
 296          * now safely switch on interrupts.
 297          */
 298         if (regs->psw.mask & PSW_MASK_PSTATE)
 299                 local_irq_enable();
 300
 301         if (notify_die(DIE_TRAP, str, regs, interruption_code,
 302                                 interruption_code, signr) == NOTIFY_STOP)
 303                 return;
 304
 305         if (regs->psw.mask & PSW_MASK_PSTATE) {
 306                 struct task_struct *tsk = current;
 307
 308                 tsk->thread.trap_no = interruption_code & 0xffff;
 309                 force_sig_info(signr, info, tsk);
 310                 report_user_fault(interruption_code, regs);
 311         } else {
 312                 const struct exception_table_entry *fixup;
 313                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
 314                 if (fixup)
 315                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
 316                 else {
 317                         enum bug_trap_type btt;
 318
 319                         btt = report_bug(regs->psw.addr & PSW_ADDR_INSN);
 320                         if (btt == BUG_TRAP_TYPE_WARN)
 321                                 return;
 322                         die(str, regs, interruption_code);
 323                 }
 324         }
 325 }
 326
 327 static inline void __user *get_check_address(struct pt_regs *regs)
 328 {
 329         return (void __user *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
 330 }
 331
 332 void __kprobes do_single_step(struct pt_regs *regs)
 333 {
 334         if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0,
 335                                         SIGTRAP) == NOTIFY_STOP){
 336                 return;
 337         }
 338         if ((current->ptrace & PT_PTRACED) != 0)
 339                 force_sig(SIGTRAP, current);
 340 }
 341
 342 static void default_trap_handler(struct pt_regs * regs, long interruption_code)
 343 {
 344         if (regs->psw.mask & PSW_MASK_PSTATE) {
 345                 local_irq_enable();
 346                 do_exit(SIGSEGV);
 347                 report_user_fault(interruption_code, regs);
 348         } else
 349                 die("Unknown program exception", regs, interruption_code);
 350 }
 351
 352 #define DO_ERROR_INFO(signr, str, name, sicode, siaddr) \
 353 static void name(struct pt_regs * regs, long interruption_code) \
 354 { \
 355         siginfo_t info; \
 356         info.si_signo = signr; \
 357         info.si_errno = 0; \
 358         info.si_code = sicode; \
 359         info.si_addr = siaddr; \
 360         do_trap(interruption_code, signr, str, regs, &info); \
 361 }
 362
 363 DO_ERROR_INFO(SIGILL, "addressing exception", addressing_exception,
 364               ILL_ILLADR, get_check_address(regs))
 365 DO_ERROR_INFO(SIGILL,  "execute exception", execute_exception,
 366               ILL_ILLOPN, get_check_address(regs))
 367 DO_ERROR_INFO(SIGFPE,  "fixpoint divide exception", divide_exception,
 368               FPE_INTDIV, get_check_address(regs))
 369 DO_ERROR_INFO(SIGFPE,  "fixpoint overflow exception", overflow_exception,
 370               FPE_INTOVF, get_check_address(regs))
 371 DO_ERROR_INFO(SIGFPE,  "HFP overflow exception", hfp_overflow_exception,
 372               FPE_FLTOVF, get_check_address(regs))
 373 DO_ERROR_INFO(SIGFPE,  "HFP underflow exception", hfp_underflow_exception,
 374               FPE_FLTUND, get_check_address(regs))
 375 DO_ERROR_INFO(SIGFPE,  "HFP significance exception", hfp_significance_exception,
 376               FPE_FLTRES, get_check_address(regs))
 377 DO_ERROR_INFO(SIGFPE,  "HFP divide exception", hfp_divide_exception,
 378               FPE_FLTDIV, get_check_address(regs))
 379 DO_ERROR_INFO(SIGFPE,  "HFP square root exception", hfp_sqrt_exception,
 380               FPE_FLTINV, get_check_address(regs))
 381 DO_ERROR_INFO(SIGILL,  "operand exception", operand_exception,
 382               ILL_ILLOPN, get_check_address(regs))
 383 DO_ERROR_INFO(SIGILL,  "privileged operation", privileged_op,
 384               ILL_PRVOPC, get_check_address(regs))
 385 DO_ERROR_INFO(SIGILL,  "special operation exception", special_op_exception,
 386               ILL_ILLOPN, get_check_address(regs))
 387 DO_ERROR_INFO(SIGILL,  "translation exception", translation_exception,
 388               ILL_ILLOPN, get_check_address(regs))
 389
 390 static inline void
 391 do_fp_trap(struct pt_regs *regs, void __user *location,
 392            int fpc, long interruption_code)
 393 {
 394         siginfo_t si;
 395
 396         si.si_signo = SIGFPE;
 397         si.si_errno = 0;
 398         si.si_addr = location;
 399         si.si_code = 0;
 400         /* FPC[2] is Data Exception Code */
 401         if ((fpc & 0x00000300) == 0) {
 402                 /* bits 6 and 7 of DXC are 0 iff IEEE exception */
 403                 if (fpc & 0x8000) /* invalid fp operation */
 404                         si.si_code = FPE_FLTINV;
 405                 else if (fpc & 0x4000) /* div by 0 */
 406                         si.si_code = FPE_FLTDIV;
 407                 else if (fpc & 0x2000) /* overflow */
 408                         si.si_code = FPE_FLTOVF;
 409                 else if (fpc & 0x1000) /* underflow */
 410                         si.si_code = FPE_FLTUND;
 411                 else if (fpc & 0x0800) /* inexact */
 412                         si.si_code = FPE_FLTRES;
 413         }
 414         current->thread.ieee_instruction_pointer = (addr_t) location;
 415         do_trap(interruption_code, SIGFPE,
 416                 "floating point exception", regs, &si);
 417 }
 418
 419 static void illegal_op(struct pt_regs * regs, long interruption_code)
 420 {
 421         siginfo_t info;
 422         __u8 opcode[6];
 423         __u16 __user *location;
 424         int signal = 0;
 425
 426         location = get_check_address(regs);
 427
 428         /*
 429          * We got all needed information from the lowcore and can
 430          * now safely switch on interrupts.
 431          */
 432         if (regs->psw.mask & PSW_MASK_PSTATE)
 433                 local_irq_enable();
 434
 435         if (regs->psw.mask & PSW_MASK_PSTATE) {
 436                 if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
 437                         return;
 438                 if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
 439                         if (current->ptrace & PT_PTRACED)
 440                                 force_sig(SIGTRAP, current);
 441                         else
 442                                 signal = SIGILL;
 443 #ifdef CONFIG_MATHEMU
 444                 } else if (opcode[0] == 0xb3) {
 445                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 446                                 return;
 447                         signal = math_emu_b3(opcode, regs);
 448                 } else if (opcode[0] == 0xed) {
 449                         if (get_user(*((__u32 *) (opcode+2)),
 450                                      (__u32 __user *)(location+1)))
 451                                 return;
 452                         signal = math_emu_ed(opcode, regs);
 453                 } else if (*((__u16 *) opcode) == 0xb299) {
 454                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 455                                 return;
 456                         signal = math_emu_srnm(opcode, regs);
 457                 } else if (*((__u16 *) opcode) == 0xb29c) {
 458                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 459                                 return;
 460                         signal = math_emu_stfpc(opcode, regs);
 461                 } else if (*((__u16 *) opcode) == 0xb29d) {
 462                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 463                                 return;
 464                         signal = math_emu_lfpc(opcode, regs);
 465 #endif
 466                 } else
 467                         signal = SIGILL;
 468         } else {
 469                 /*
 470                  * If we get an illegal op in kernel mode, send it through the
 471                  * kprobes notifier. If kprobes doesn't pick it up, SIGILL
 472                  */
 473                 if (notify_die(DIE_BPT, "bpt", regs, interruption_code,
 474                                3, SIGTRAP) != NOTIFY_STOP)
 475                         signal = SIGILL;
 476         }
 477
 478 #ifdef CONFIG_MATHEMU
 479         if (signal == SIGFPE)
 480                 do_fp_trap(regs, location,
 481                            current->thread.fp_regs.fpc, interruption_code);
 482         else if (signal == SIGSEGV) {
 483                 info.si_signo = signal;
 484                 info.si_errno = 0;
 485                 info.si_code = SEGV_MAPERR;
 486                 info.si_addr = (void __user *) location;
 487                 do_trap(interruption_code, signal,
 488                         "user address fault", regs, &info);
 489         } else
 490 #endif
 491         if (signal) {
 492                 info.si_signo = signal;
 493                 info.si_errno = 0;
 494                 info.si_code = ILL_ILLOPC;
 495                 info.si_addr = (void __user *) location;
 496                 do_trap(interruption_code, signal,
 497                         "illegal operation", regs, &info);
 498         }
 499 }
 500
 501
 502 #ifdef CONFIG_MATHEMU
 503 asmlinkage void
 504 specification_exception(struct pt_regs * regs, long interruption_code)
 505 {
 506         __u8 opcode[6];
 507         __u16 __user *location = NULL;
 508         int signal = 0;
 509
 510         location = (__u16 __user *) get_check_address(regs);
 511
 512         /*
 513          * We got all needed information from the lowcore and can
 514          * now safely switch on interrupts.
 515          */
 516         if (regs->psw.mask & PSW_MASK_PSTATE)
 517                 local_irq_enable();
 518
 519         if (regs->psw.mask & PSW_MASK_PSTATE) {
 520                 get_user(*((__u16 *) opcode), location);
 521                 switch (opcode[0]) {
 522                 case 0x28: /* LDR Rx,Ry   */
 523                         signal = math_emu_ldr(opcode);
 524                         break;
 525                 case 0x38: /* LER Rx,Ry   */
 526                         signal = math_emu_ler(opcode);
 527                         break;
 528                 case 0x60: /* STD R,D(X,B) */
 529                         get_user(*((__u16 *) (opcode+2)), location+1);
 530                         signal = math_emu_std(opcode, regs);
 531                         break;
 532                 case 0x68: /* LD R,D(X,B) */
 533                         get_user(*((__u16 *) (opcode+2)), location+1);
 534                         signal = math_emu_ld(opcode, regs);
 535                         break;
 536                 case 0x70: /* STE R,D(X,B) */
 537                         get_user(*((__u16 *) (opcode+2)), location+1);
 538                         signal = math_emu_ste(opcode, regs);
 539                         break;
 540                 case 0x78: /* LE R,D(X,B) */
 541                         get_user(*((__u16 *) (opcode+2)), location+1);
 542                         signal = math_emu_le(opcode, regs);
 543                         break;
 544                 default:
 545                         signal = SIGILL;
 546                         break;
 547                 }
 548         } else
 549                 signal = SIGILL;
 550
 551         if (signal == SIGFPE)
 552                 do_fp_trap(regs, location,
 553                            current->thread.fp_regs.fpc, interruption_code);
 554         else if (signal) {
 555                 siginfo_t info;
 556                 info.si_signo = signal;
 557                 info.si_errno = 0;
 558                 info.si_code = ILL_ILLOPN;
 559                 info.si_addr = location;
 560                 do_trap(interruption_code, signal,
 561                         "specification exception", regs, &info);
 562         }
 563 }
 564 #else
 565 DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
 566               ILL_ILLOPN, get_check_address(regs));
 567 #endif
 568
 569 static void data_exception(struct pt_regs * regs, long interruption_code)
 570 {
 571         __u16 __user *location;
 572         int signal = 0;
 573
 574         location = get_check_address(regs);
 575
 576         /*
 577          * We got all needed information from the lowcore and can
 578          * now safely switch on interrupts.
 579          */
 580         if (regs->psw.mask & PSW_MASK_PSTATE)
 581                 local_irq_enable();
 582
 583         if (MACHINE_HAS_IEEE)
 584                 asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
 585
 586 #ifdef CONFIG_MATHEMU
 587         else if (regs->psw.mask & PSW_MASK_PSTATE) {
 588                 __u8 opcode[6];
 589                 get_user(*((__u16 *) opcode), location);
 590                 switch (opcode[0]) {
 591                 case 0x28: /* LDR Rx,Ry   */
 592                         signal = math_emu_ldr(opcode);
 593                         break;
 594                 case 0x38: /* LER Rx,Ry   */
 595                         signal = math_emu_ler(opcode);
 596                         break;
 597                 case 0x60: /* STD R,D(X,B) */
 598                         get_user(*((__u16 *) (opcode+2)), location+1);
 599                         signal = math_emu_std(opcode, regs);
 600                         break;
 601                 case 0x68: /* LD R,D(X,B) */
 602                         get_user(*((__u16 *) (opcode+2)), location+1);
 603                         signal = math_emu_ld(opcode, regs);
 604                         break;
 605                 case 0x70: /* STE R,D(X,B) */
 606                         get_user(*((__u16 *) (opcode+2)), location+1);
 607                         signal = math_emu_ste(opcode, regs);
 608                         break;
 609                 case 0x78: /* LE R,D(X,B) */
 610                         get_user(*((__u16 *) (opcode+2)), location+1);
 611                         signal = math_emu_le(opcode, regs);
 612                         break;
 613                 case 0xb3:
 614                         get_user(*((__u16 *) (opcode+2)), location+1);
 615                         signal = math_emu_b3(opcode, regs);
 616                         break;
 617                 case 0xed:
 618                         get_user(*((__u32 *) (opcode+2)),
 619                                  (__u32 __user *)(location+1));
 620                         signal = math_emu_ed(opcode, regs);
 621                         break;
 622                 case 0xb2:
 623                         if (opcode[1] == 0x99) {
 624                                 get_user(*((__u16 *) (opcode+2)), location+1);
 625                                 signal = math_emu_srnm(opcode, regs);
 626                         } else if (opcode[1] == 0x9c) {
 627                                 get_user(*((__u16 *) (opcode+2)), location+1);
 628                                 signal = math_emu_stfpc(opcode, regs);
 629                         } else if (opcode[1] == 0x9d) {
 630                                 get_user(*((__u16 *) (opcode+2)), location+1);
 631                                 signal = math_emu_lfpc(opcode, regs);
 632                         } else
 633                                 signal = SIGILL;
 634                         break;
 635                 default:
 636                         signal = SIGILL;
 637                         break;
 638                 }
 639         }
 640 #endif
 641         if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
 642                 signal = SIGFPE;
 643         else
 644                 signal = SIGILL;
 645         if (signal == SIGFPE)
 646                 do_fp_trap(regs, location,
 647                            current->thread.fp_regs.fpc, interruption_code);
 648         else if (signal) {
 649                 siginfo_t info;
 650                 info.si_signo = signal;
 651                 info.si_errno = 0;
 652                 info.si_code = ILL_ILLOPN;
 653                 info.si_addr = location;
 654                 do_trap(interruption_code, signal,
 655                         "data exception", regs, &info);
 656         }
 657 }
 658
 659 static void space_switch_exception(struct pt_regs * regs, long int_code)
 660 {
 661         siginfo_t info;
 662
 663         /* Set user psw back to home space mode. */
 664         if (regs->psw.mask & PSW_MASK_PSTATE)
 665                 regs->psw.mask |= PSW_ASC_HOME;
 666         /* Send SIGILL. */
 667         info.si_signo = SIGILL;
 668         info.si_errno = 0;
 669         info.si_code = ILL_PRVOPC;
 670         info.si_addr = get_check_address(regs);
 671         do_trap(int_code, SIGILL, "space switch event", regs, &info);
 672 }
 673
 674 asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
 675 {
 676         bust_spinlocks(1);
 677         printk("Kernel stack overflow.\n");
 678         show_regs(regs);
 679         bust_spinlocks(0);
 680         panic("Corrupt kernel stack, can't continue.");
 681 }
 682
 683 /* init is done in lowcore.S and head.S */
 684
 685 void __init trap_init(void)
 686 {
 687         int i;
 688
 689         for (i = 0; i < 128; i++)
 690           pgm_check_table[i] = &default_trap_handler;
 691         pgm_check_table[1] = &illegal_op;
 692         pgm_check_table[2] = &privileged_op;
 693         pgm_check_table[3] = &execute_exception;
 694         pgm_check_table[4] = &do_protection_exception;
 695         pgm_check_table[5] = &addressing_exception;
 696         pgm_check_table[6] = &specification_exception;
 697         pgm_check_table[7] = &data_exception;
 698         pgm_check_table[8] = &overflow_exception;
 699         pgm_check_table[9] = &divide_exception;
 700         pgm_check_table[0x0A] = &overflow_exception;
 701         pgm_check_table[0x0B] = &divide_exception;
 702         pgm_check_table[0x0C] = &hfp_overflow_exception;
 703         pgm_check_table[0x0D] = &hfp_underflow_exception;
 704         pgm_check_table[0x0E] = &hfp_significance_exception;
 705         pgm_check_table[0x0F] = &hfp_divide_exception;
 706         pgm_check_table[0x10] = &do_dat_exception;
 707         pgm_check_table[0x11] = &do_dat_exception;
 708         pgm_check_table[0x12] = &translation_exception;
 709         pgm_check_table[0x13] = &special_op_exception;
 710 #ifdef CONFIG_64BIT
 711         pgm_check_table[0x38] = &do_dat_exception;
 712         pgm_check_table[0x39] = &do_dat_exception;
 713         pgm_check_table[0x3A] = &do_dat_exception;
 714         pgm_check_table[0x3B] = &do_dat_exception;
 715 #endif /* CONFIG_64BIT */
 716         pgm_check_table[0x15] = &operand_exception;
 717         pgm_check_table[0x1C] = &space_switch_exception;
 718         pgm_check_table[0x1D] = &hfp_sqrt_exception;
 719         pgm_check_table[0x40] = &do_monitor_call;
 720         pfault_irq_init();
 721 }