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   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 FOURLONG "%08lx %08lx %08lx %08lx\n"
  65 static int kstack_depth_to_print = 12;
  66 #else /* CONFIG_64BIT */
  67 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
  68 static int kstack_depth_to_print = 20;
  69 #endif /* CONFIG_64BIT */
  70
  71 /*
  72  * For show_trace we have tree different stack to consider:
  73  *   - the panic stack which is used if the kernel stack has overflown
  74  *   - the asynchronous interrupt stack (cpu related)
  75  *   - the synchronous kernel stack (process related)
  76  * The stack trace can start at any of the three stack and can potentially
  77  * touch all of them. The order is: panic stack, async stack, sync stack.
  78  */
  79 static unsigned long
  80 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
  81 {
  82         struct stack_frame *sf;
  83         struct pt_regs *regs;
  84
  85         while (1) {
  86                 sp = sp & PSW_ADDR_INSN;
  87                 if (sp < low || sp > high - sizeof(*sf))
  88                         return sp;
  89                 sf = (struct stack_frame *) sp;
  90                 printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
  91                 print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
  92                 /* Follow the backchain. */
  93                 while (1) {
  94                         low = sp;
  95                         sp = sf->back_chain & PSW_ADDR_INSN;
  96                         if (!sp)
  97                                 break;
  98                         if (sp <= low || sp > high - sizeof(*sf))
  99                                 return sp;
 100                         sf = (struct stack_frame *) sp;
 101                         printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
 102                         print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
 103                 }
 104                 /* Zero backchain detected, check for interrupt frame. */
 105                 sp = (unsigned long) (sf + 1);
 106                 if (sp <= low || sp > high - sizeof(*regs))
 107                         return sp;
 108                 regs = (struct pt_regs *) sp;
 109                 printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
 110                 print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
 111                 low = sp;
 112                 sp = regs->gprs[15];
 113         }
 114 }
 115
 116 static void show_trace(struct task_struct *task, unsigned long *stack)
 117 {
 118         register unsigned long __r15 asm ("15");
 119         unsigned long sp;
 120
 121         sp = (unsigned long) stack;
 122         if (!sp)
 123                 sp = task ? task->thread.ksp : __r15;
 124         printk("Call Trace:\n");
 125 #ifdef CONFIG_CHECK_STACK
 126         sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
 127                           S390_lowcore.panic_stack);
 128 #endif
 129         sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
 130                           S390_lowcore.async_stack);
 131         if (task)
 132                 __show_trace(sp, (unsigned long) task_stack_page(task),
 133                              (unsigned long) task_stack_page(task) + THREAD_SIZE);
 134         else
 135                 __show_trace(sp, S390_lowcore.thread_info,
 136                              S390_lowcore.thread_info + THREAD_SIZE);
 137         if (!task)
 138                 task = current;
 139         debug_show_held_locks(task);
 140 }
 141
 142 void show_stack(struct task_struct *task, unsigned long *sp)
 143 {
 144         register unsigned long * __r15 asm ("15");
 145         unsigned long *stack;
 146         int i;
 147
 148         if (!sp)
 149                 stack = task ? (unsigned long *) task->thread.ksp : __r15;
 150         else
 151                 stack = sp;
 152
 153         for (i = 0; i < kstack_depth_to_print; i++) {
 154                 if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
 155                         break;
 156                 if (i && ((i * sizeof (long) % 32) == 0))
 157                         printk("\n       ");
 158                 printk("%p ", (void *)*stack++);
 159         }
 160         printk("\n");
 161         show_trace(task, sp);
 162 }
 163
 164 static void show_last_breaking_event(struct pt_regs *regs)
 165 {
 166 #ifdef CONFIG_64BIT
 167         printk("Last Breaking-Event-Address:\n");
 168         printk(" [<%016lx>] ", regs->args[0] & PSW_ADDR_INSN);
 169         print_symbol("%s\n", regs->args[0] & PSW_ADDR_INSN);
 170 #endif
 171 }
 172
 173 /*
 174  * The architecture-independent dump_stack generator
 175  */
 176 void dump_stack(void)
 177 {
 178         printk("CPU: %d %s %s %.*s\n",
 179                task_thread_info(current)->cpu, print_tainted(),
 180                init_utsname()->release,
 181                (int)strcspn(init_utsname()->version, " "),
 182                init_utsname()->version);
 183         printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
 184                current->comm, current->pid, current,
 185                (void *) current->thread.ksp);
 186         show_stack(NULL, NULL);
 187 }
 188 EXPORT_SYMBOL(dump_stack);
 189
 190 static inline int mask_bits(struct pt_regs *regs, unsigned long bits)
 191 {
 192         return (regs->psw.mask & bits) / ((~bits + 1) & bits);
 193 }
 194
 195 void show_registers(struct pt_regs *regs)
 196 {
 197         char *mode;
 198
 199         mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
 200         printk("%s PSW : %p %p",
 201                mode, (void *) regs->psw.mask,
 202                (void *) regs->psw.addr);
 203         print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
 204         printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
 205                "P:%x AS:%x CC:%x PM:%x", mask_bits(regs, PSW_MASK_PER),
 206                mask_bits(regs, PSW_MASK_DAT), mask_bits(regs, PSW_MASK_IO),
 207                mask_bits(regs, PSW_MASK_EXT), mask_bits(regs, PSW_MASK_KEY),
 208                mask_bits(regs, PSW_MASK_MCHECK), mask_bits(regs, PSW_MASK_WAIT),
 209                mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC),
 210                mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM));
 211 #ifdef CONFIG_64BIT
 212         printk(" EA:%x", mask_bits(regs, PSW_BASE_BITS));
 213 #endif
 214         printk("\n%s GPRS: " FOURLONG, mode,
 215                regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
 216         printk("           " FOURLONG,
 217                regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
 218         printk("           " FOURLONG,
 219                regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
 220         printk("           " FOURLONG,
 221                regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
 222
 223         show_code(regs);
 224 }
 225
 226 void show_regs(struct pt_regs *regs)
 227 {
 228         print_modules();
 229         printk("CPU: %d %s %s %.*s\n",
 230                task_thread_info(current)->cpu, print_tainted(),
 231                init_utsname()->release,
 232                (int)strcspn(init_utsname()->version, " "),
 233                init_utsname()->version);
 234         printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
 235                current->comm, current->pid, current,
 236                (void *) current->thread.ksp);
 237         show_registers(regs);
 238         /* Show stack backtrace if pt_regs is from kernel mode */
 239         if (!(regs->psw.mask & PSW_MASK_PSTATE))
 240                 show_trace(NULL, (unsigned long *) regs->gprs[15]);
 241         show_last_breaking_event(regs);
 242 }
 243
 244 /* This is called from fs/proc/array.c */
 245 void task_show_regs(struct seq_file *m, struct task_struct *task)
 246 {
 247         struct pt_regs *regs;
 248
 249         regs = task_pt_regs(task);
 250         seq_printf(m, "task: %p, ksp: %p\n",
 251                        task, (void *)task->thread.ksp);
 252         seq_printf(m, "User PSW : %p %p\n",
 253                        (void *) regs->psw.mask, (void *)regs->psw.addr);
 254
 255         seq_printf(m, "User GPRS: " FOURLONG,
 256                           regs->gprs[0], regs->gprs[1],
 257                           regs->gprs[2], regs->gprs[3]);
 258         seq_printf(m, "           " FOURLONG,
 259                           regs->gprs[4], regs->gprs[5],
 260                           regs->gprs[6], regs->gprs[7]);
 261         seq_printf(m, "           " FOURLONG,
 262                           regs->gprs[8], regs->gprs[9],
 263                           regs->gprs[10], regs->gprs[11]);
 264         seq_printf(m, "           " FOURLONG,
 265                           regs->gprs[12], regs->gprs[13],
 266                           regs->gprs[14], regs->gprs[15]);
 267         seq_printf(m, "User ACRS: %08x %08x %08x %08x\n",
 268                           task->thread.acrs[0], task->thread.acrs[1],
 269                           task->thread.acrs[2], task->thread.acrs[3]);
 270         seq_printf(m, "           %08x %08x %08x %08x\n",
 271                           task->thread.acrs[4], task->thread.acrs[5],
 272                           task->thread.acrs[6], task->thread.acrs[7]);
 273         seq_printf(m, "           %08x %08x %08x %08x\n",
 274                           task->thread.acrs[8], task->thread.acrs[9],
 275                           task->thread.acrs[10], task->thread.acrs[11]);
 276         seq_printf(m, "           %08x %08x %08x %08x\n",
 277                           task->thread.acrs[12], task->thread.acrs[13],
 278                           task->thread.acrs[14], task->thread.acrs[15]);
 279 }
 280
 281 static DEFINE_SPINLOCK(die_lock);
 282
 283 void die(const char * str, struct pt_regs * regs, long err)
 284 {
 285         static int die_counter;
 286
 287         oops_enter();
 288         debug_stop_all();
 289         console_verbose();
 290         spin_lock_irq(&die_lock);
 291         bust_spinlocks(1);
 292         printk("%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
 293 #ifdef CONFIG_PREEMPT
 294         printk("PREEMPT ");
 295 #endif
 296 #ifdef CONFIG_SMP
 297         printk("SMP ");
 298 #endif
 299 #ifdef CONFIG_DEBUG_PAGEALLOC
 300         printk("DEBUG_PAGEALLOC");
 301 #endif
 302         printk("\n");
 303         notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
 304         show_regs(regs);
 305         bust_spinlocks(0);
 306         add_taint(TAINT_DIE);
 307         spin_unlock_irq(&die_lock);
 308         if (in_interrupt())
 309                 panic("Fatal exception in interrupt");
 310         if (panic_on_oops)
 311                 panic("Fatal exception: panic_on_oops");
 312         oops_exit();
 313         do_exit(SIGSEGV);
 314 }
 315
 316 static void inline
 317 report_user_fault(long interruption_code, struct pt_regs *regs)
 318 {
 319 #if defined(CONFIG_SYSCTL)
 320         if (!sysctl_userprocess_debug)
 321                 return;
 322 #endif
 323 #if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG)
 324         printk("User process fault: interruption code 0x%lX\n",
 325                interruption_code);
 326         show_regs(regs);
 327 #endif
 328 }
 329
 330 int is_valid_bugaddr(unsigned long addr)
 331 {
 332         return 1;
 333 }
 334
 335 static void __kprobes inline do_trap(long interruption_code, int signr,
 336                                         char *str, struct pt_regs *regs,
 337                                         siginfo_t *info)
 338 {
 339         /*
 340          * We got all needed information from the lowcore and can
 341          * now safely switch on interrupts.
 342          */
 343         if (regs->psw.mask & PSW_MASK_PSTATE)
 344                 local_irq_enable();
 345
 346         if (notify_die(DIE_TRAP, str, regs, interruption_code,
 347                                 interruption_code, signr) == NOTIFY_STOP)
 348                 return;
 349
 350         if (regs->psw.mask & PSW_MASK_PSTATE) {
 351                 struct task_struct *tsk = current;
 352
 353                 tsk->thread.trap_no = interruption_code & 0xffff;
 354                 force_sig_info(signr, info, tsk);
 355                 report_user_fault(interruption_code, regs);
 356         } else {
 357                 const struct exception_table_entry *fixup;
 358                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
 359                 if (fixup)
 360                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
 361                 else {
 362                         enum bug_trap_type btt;
 363
 364                         btt = report_bug(regs->psw.addr & PSW_ADDR_INSN, regs);
 365                         if (btt == BUG_TRAP_TYPE_WARN)
 366                                 return;
 367                         die(str, regs, interruption_code);
 368                 }
 369         }
 370 }
 371
 372 static inline void __user *get_check_address(struct pt_regs *regs)
 373 {
 374         return (void __user *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
 375 }
 376
 377 void __kprobes do_single_step(struct pt_regs *regs)
 378 {
 379         if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0,
 380                                         SIGTRAP) == NOTIFY_STOP){
 381                 return;
 382         }
 383         if ((current->ptrace & PT_PTRACED) != 0)
 384                 force_sig(SIGTRAP, current);
 385 }
 386
 387 static void default_trap_handler(struct pt_regs * regs, long interruption_code)
 388 {
 389         if (regs->psw.mask & PSW_MASK_PSTATE) {
 390                 local_irq_enable();
 391                 do_exit(SIGSEGV);
 392                 report_user_fault(interruption_code, regs);
 393         } else
 394                 die("Unknown program exception", regs, interruption_code);
 395 }
 396
 397 #define DO_ERROR_INFO(signr, str, name, sicode, siaddr) \
 398 static void name(struct pt_regs * regs, long interruption_code) \
 399 { \
 400         siginfo_t info; \
 401         info.si_signo = signr; \
 402         info.si_errno = 0; \
 403         info.si_code = sicode; \
 404         info.si_addr = siaddr; \
 405         do_trap(interruption_code, signr, str, regs, &info); \
 406 }
 407
 408 DO_ERROR_INFO(SIGILL, "addressing exception", addressing_exception,
 409               ILL_ILLADR, get_check_address(regs))
 410 DO_ERROR_INFO(SIGILL,  "execute exception", execute_exception,
 411               ILL_ILLOPN, get_check_address(regs))
 412 DO_ERROR_INFO(SIGFPE,  "fixpoint divide exception", divide_exception,
 413               FPE_INTDIV, get_check_address(regs))
 414 DO_ERROR_INFO(SIGFPE,  "fixpoint overflow exception", overflow_exception,
 415               FPE_INTOVF, get_check_address(regs))
 416 DO_ERROR_INFO(SIGFPE,  "HFP overflow exception", hfp_overflow_exception,
 417               FPE_FLTOVF, get_check_address(regs))
 418 DO_ERROR_INFO(SIGFPE,  "HFP underflow exception", hfp_underflow_exception,
 419               FPE_FLTUND, get_check_address(regs))
 420 DO_ERROR_INFO(SIGFPE,  "HFP significance exception", hfp_significance_exception,
 421               FPE_FLTRES, get_check_address(regs))
 422 DO_ERROR_INFO(SIGFPE,  "HFP divide exception", hfp_divide_exception,
 423               FPE_FLTDIV, get_check_address(regs))
 424 DO_ERROR_INFO(SIGFPE,  "HFP square root exception", hfp_sqrt_exception,
 425               FPE_FLTINV, get_check_address(regs))
 426 DO_ERROR_INFO(SIGILL,  "operand exception", operand_exception,
 427               ILL_ILLOPN, get_check_address(regs))
 428 DO_ERROR_INFO(SIGILL,  "privileged operation", privileged_op,
 429               ILL_PRVOPC, get_check_address(regs))
 430 DO_ERROR_INFO(SIGILL,  "special operation exception", special_op_exception,
 431               ILL_ILLOPN, get_check_address(regs))
 432 DO_ERROR_INFO(SIGILL,  "translation exception", translation_exception,
 433               ILL_ILLOPN, get_check_address(regs))
 434
 435 static inline void
 436 do_fp_trap(struct pt_regs *regs, void __user *location,
 437            int fpc, long interruption_code)
 438 {
 439         siginfo_t si;
 440
 441         si.si_signo = SIGFPE;
 442         si.si_errno = 0;
 443         si.si_addr = location;
 444         si.si_code = 0;
 445         /* FPC[2] is Data Exception Code */
 446         if ((fpc & 0x00000300) == 0) {
 447                 /* bits 6 and 7 of DXC are 0 iff IEEE exception */
 448                 if (fpc & 0x8000) /* invalid fp operation */
 449                         si.si_code = FPE_FLTINV;
 450                 else if (fpc & 0x4000) /* div by 0 */
 451                         si.si_code = FPE_FLTDIV;
 452                 else if (fpc & 0x2000) /* overflow */
 453                         si.si_code = FPE_FLTOVF;
 454                 else if (fpc & 0x1000) /* underflow */
 455                         si.si_code = FPE_FLTUND;
 456                 else if (fpc & 0x0800) /* inexact */
 457                         si.si_code = FPE_FLTRES;
 458         }
 459         current->thread.ieee_instruction_pointer = (addr_t) location;
 460         do_trap(interruption_code, SIGFPE,
 461                 "floating point exception", regs, &si);
 462 }
 463
 464 static void illegal_op(struct pt_regs * regs, long interruption_code)
 465 {
 466         siginfo_t info;
 467         __u8 opcode[6];
 468         __u16 __user *location;
 469         int signal = 0;
 470
 471         location = get_check_address(regs);
 472
 473         /*
 474          * We got all needed information from the lowcore and can
 475          * now safely switch on interrupts.
 476          */
 477         if (regs->psw.mask & PSW_MASK_PSTATE)
 478                 local_irq_enable();
 479
 480         if (regs->psw.mask & PSW_MASK_PSTATE) {
 481                 if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
 482                         return;
 483                 if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
 484                         if (current->ptrace & PT_PTRACED)
 485                                 force_sig(SIGTRAP, current);
 486                         else
 487                                 signal = SIGILL;
 488 #ifdef CONFIG_MATHEMU
 489                 } else if (opcode[0] == 0xb3) {
 490                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 491                                 return;
 492                         signal = math_emu_b3(opcode, regs);
 493                 } else if (opcode[0] == 0xed) {
 494                         if (get_user(*((__u32 *) (opcode+2)),
 495                                      (__u32 __user *)(location+1)))
 496                                 return;
 497                         signal = math_emu_ed(opcode, regs);
 498                 } else if (*((__u16 *) opcode) == 0xb299) {
 499                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 500                                 return;
 501                         signal = math_emu_srnm(opcode, regs);
 502                 } else if (*((__u16 *) opcode) == 0xb29c) {
 503                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 504                                 return;
 505                         signal = math_emu_stfpc(opcode, regs);
 506                 } else if (*((__u16 *) opcode) == 0xb29d) {
 507                         if (get_user(*((__u16 *) (opcode+2)), location+1))
 508                                 return;
 509                         signal = math_emu_lfpc(opcode, regs);
 510 #endif
 511                 } else
 512                         signal = SIGILL;
 513         } else {
 514                 /*
 515                  * If we get an illegal op in kernel mode, send it through the
 516                  * kprobes notifier. If kprobes doesn't pick it up, SIGILL
 517                  */
 518                 if (notify_die(DIE_BPT, "bpt", regs, interruption_code,
 519                                3, SIGTRAP) != NOTIFY_STOP)
 520                         signal = SIGILL;
 521         }
 522
 523 #ifdef CONFIG_MATHEMU
 524         if (signal == SIGFPE)
 525                 do_fp_trap(regs, location,
 526                            current->thread.fp_regs.fpc, interruption_code);
 527         else if (signal == SIGSEGV) {
 528                 info.si_signo = signal;
 529                 info.si_errno = 0;
 530                 info.si_code = SEGV_MAPERR;
 531                 info.si_addr = (void __user *) location;
 532                 do_trap(interruption_code, signal,
 533                         "user address fault", regs, &info);
 534         } else
 535 #endif
 536         if (signal) {
 537                 info.si_signo = signal;
 538                 info.si_errno = 0;
 539                 info.si_code = ILL_ILLOPC;
 540                 info.si_addr = (void __user *) location;
 541                 do_trap(interruption_code, signal,
 542                         "illegal operation", regs, &info);
 543         }
 544 }
 545
 546
 547 #ifdef CONFIG_MATHEMU
 548 asmlinkage void
 549 specification_exception(struct pt_regs * regs, long interruption_code)
 550 {
 551         __u8 opcode[6];
 552         __u16 __user *location = NULL;
 553         int signal = 0;
 554
 555         location = (__u16 __user *) get_check_address(regs);
 556
 557         /*
 558          * We got all needed information from the lowcore and can
 559          * now safely switch on interrupts.
 560          */
 561         if (regs->psw.mask & PSW_MASK_PSTATE)
 562                 local_irq_enable();
 563
 564         if (regs->psw.mask & PSW_MASK_PSTATE) {
 565                 get_user(*((__u16 *) opcode), location);
 566                 switch (opcode[0]) {
 567                 case 0x28: /* LDR Rx,Ry   */
 568                         signal = math_emu_ldr(opcode);
 569                         break;
 570                 case 0x38: /* LER Rx,Ry   */
 571                         signal = math_emu_ler(opcode);
 572                         break;
 573                 case 0x60: /* STD R,D(X,B) */
 574                         get_user(*((__u16 *) (opcode+2)), location+1);
 575                         signal = math_emu_std(opcode, regs);
 576                         break;
 577                 case 0x68: /* LD R,D(X,B) */
 578                         get_user(*((__u16 *) (opcode+2)), location+1);
 579                         signal = math_emu_ld(opcode, regs);
 580                         break;
 581                 case 0x70: /* STE R,D(X,B) */
 582                         get_user(*((__u16 *) (opcode+2)), location+1);
 583                         signal = math_emu_ste(opcode, regs);
 584                         break;
 585                 case 0x78: /* LE R,D(X,B) */
 586                         get_user(*((__u16 *) (opcode+2)), location+1);
 587                         signal = math_emu_le(opcode, regs);
 588                         break;
 589                 default:
 590                         signal = SIGILL;
 591                         break;
 592                 }
 593         } else
 594                 signal = SIGILL;
 595
 596         if (signal == SIGFPE)
 597                 do_fp_trap(regs, location,
 598                            current->thread.fp_regs.fpc, interruption_code);
 599         else if (signal) {
 600                 siginfo_t info;
 601                 info.si_signo = signal;
 602                 info.si_errno = 0;
 603                 info.si_code = ILL_ILLOPN;
 604                 info.si_addr = location;
 605                 do_trap(interruption_code, signal,
 606                         "specification exception", regs, &info);
 607         }
 608 }
 609 #else
 610 DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
 611               ILL_ILLOPN, get_check_address(regs));
 612 #endif
 613
 614 static void data_exception(struct pt_regs * regs, long interruption_code)
 615 {
 616         __u16 __user *location;
 617         int signal = 0;
 618
 619         location = get_check_address(regs);
 620
 621         /*
 622          * We got all needed information from the lowcore and can
 623          * now safely switch on interrupts.
 624          */
 625         if (regs->psw.mask & PSW_MASK_PSTATE)
 626                 local_irq_enable();
 627
 628         if (MACHINE_HAS_IEEE)
 629                 asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
 630
 631 #ifdef CONFIG_MATHEMU
 632         else if (regs->psw.mask & PSW_MASK_PSTATE) {
 633                 __u8 opcode[6];
 634                 get_user(*((__u16 *) opcode), location);
 635                 switch (opcode[0]) {
 636                 case 0x28: /* LDR Rx,Ry   */
 637                         signal = math_emu_ldr(opcode);
 638                         break;
 639                 case 0x38: /* LER Rx,Ry   */
 640                         signal = math_emu_ler(opcode);
 641                         break;
 642                 case 0x60: /* STD R,D(X,B) */
 643                         get_user(*((__u16 *) (opcode+2)), location+1);
 644                         signal = math_emu_std(opcode, regs);
 645                         break;
 646                 case 0x68: /* LD R,D(X,B) */
 647                         get_user(*((__u16 *) (opcode+2)), location+1);
 648                         signal = math_emu_ld(opcode, regs);
 649                         break;
 650                 case 0x70: /* STE R,D(X,B) */
 651                         get_user(*((__u16 *) (opcode+2)), location+1);
 652                         signal = math_emu_ste(opcode, regs);
 653                         break;
 654                 case 0x78: /* LE R,D(X,B) */
 655                         get_user(*((__u16 *) (opcode+2)), location+1);
 656                         signal = math_emu_le(opcode, regs);
 657                         break;
 658                 case 0xb3:
 659                         get_user(*((__u16 *) (opcode+2)), location+1);
 660                         signal = math_emu_b3(opcode, regs);
 661                         break;
 662                 case 0xed:
 663                         get_user(*((__u32 *) (opcode+2)),
 664                                  (__u32 __user *)(location+1));
 665                         signal = math_emu_ed(opcode, regs);
 666                         break;
 667                 case 0xb2:
 668                         if (opcode[1] == 0x99) {
 669                                 get_user(*((__u16 *) (opcode+2)), location+1);
 670                                 signal = math_emu_srnm(opcode, regs);
 671                         } else if (opcode[1] == 0x9c) {
 672                                 get_user(*((__u16 *) (opcode+2)), location+1);
 673                                 signal = math_emu_stfpc(opcode, regs);
 674                         } else if (opcode[1] == 0x9d) {
 675                                 get_user(*((__u16 *) (opcode+2)), location+1);
 676                                 signal = math_emu_lfpc(opcode, regs);
 677                         } else
 678                                 signal = SIGILL;
 679                         break;
 680                 default:
 681                         signal = SIGILL;
 682                         break;
 683                 }
 684         }
 685 #endif
 686         if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
 687                 signal = SIGFPE;
 688         else
 689                 signal = SIGILL;
 690         if (signal == SIGFPE)
 691                 do_fp_trap(regs, location,
 692                            current->thread.fp_regs.fpc, interruption_code);
 693         else if (signal) {
 694                 siginfo_t info;
 695                 info.si_signo = signal;
 696                 info.si_errno = 0;
 697                 info.si_code = ILL_ILLOPN;
 698                 info.si_addr = location;
 699                 do_trap(interruption_code, signal,
 700                         "data exception", regs, &info);
 701         }
 702 }
 703
 704 static void space_switch_exception(struct pt_regs * regs, long int_code)
 705 {
 706         siginfo_t info;
 707
 708         /* Set user psw back to home space mode. */
 709         if (regs->psw.mask & PSW_MASK_PSTATE)
 710                 regs->psw.mask |= PSW_ASC_HOME;
 711         /* Send SIGILL. */
 712         info.si_signo = SIGILL;
 713         info.si_errno = 0;
 714         info.si_code = ILL_PRVOPC;
 715         info.si_addr = get_check_address(regs);
 716         do_trap(int_code, SIGILL, "space switch event", regs, &info);
 717 }
 718
 719 asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
 720 {
 721         bust_spinlocks(1);
 722         printk("Kernel stack overflow.\n");
 723         show_regs(regs);
 724         bust_spinlocks(0);
 725         panic("Corrupt kernel stack, can't continue.");
 726 }
 727
 728 /* init is done in lowcore.S and head.S */
 729
 730 void __init trap_init(void)
 731 {
 732         int i;
 733
 734         for (i = 0; i < 128; i++)
 735           pgm_check_table[i] = &default_trap_handler;
 736         pgm_check_table[1] = &illegal_op;
 737         pgm_check_table[2] = &privileged_op;
 738         pgm_check_table[3] = &execute_exception;
 739         pgm_check_table[4] = &do_protection_exception;
 740         pgm_check_table[5] = &addressing_exception;
 741         pgm_check_table[6] = &specification_exception;
 742         pgm_check_table[7] = &data_exception;
 743         pgm_check_table[8] = &overflow_exception;
 744         pgm_check_table[9] = &divide_exception;
 745         pgm_check_table[0x0A] = &overflow_exception;
 746         pgm_check_table[0x0B] = &divide_exception;
 747         pgm_check_table[0x0C] = &hfp_overflow_exception;
 748         pgm_check_table[0x0D] = &hfp_underflow_exception;
 749         pgm_check_table[0x0E] = &hfp_significance_exception;
 750         pgm_check_table[0x0F] = &hfp_divide_exception;
 751         pgm_check_table[0x10] = &do_dat_exception;
 752         pgm_check_table[0x11] = &do_dat_exception;
 753         pgm_check_table[0x12] = &translation_exception;
 754         pgm_check_table[0x13] = &special_op_exception;
 755 #ifdef CONFIG_64BIT
 756         pgm_check_table[0x38] = &do_asce_exception;
 757         pgm_check_table[0x39] = &do_dat_exception;
 758         pgm_check_table[0x3A] = &do_dat_exception;
 759         pgm_check_table[0x3B] = &do_dat_exception;
 760 #endif /* CONFIG_64BIT */
 761         pgm_check_table[0x15] = &operand_exception;
 762         pgm_check_table[0x1C] = &space_switch_exception;
 763         pgm_check_table[0x1D] = &hfp_sqrt_exception;
 764         pfault_irq_init();
 765 }