bc7b7be7acbe7b9858992e75fcc86309d59de79b
[linux-2.6.git] / 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/config.h>
18 #include <linux/sched.h>
19 #include <linux/kernel.h>
20 #include <linux/string.h>
21 #include <linux/errno.h>
22 #include <linux/ptrace.h>
23 #include <linux/timer.h>
24 #include <linux/mm.h>
25 #include <linux/smp.h>
26 #include <linux/smp_lock.h>
27 #include <linux/init.h>
28 #include <linux/interrupt.h>
29 #include <linux/delay.h>
30 #include <linux/module.h>
31 #include <linux/kallsyms.h>
32
33 #include <asm/system.h>
34 #include <asm/uaccess.h>
35 #include <asm/io.h>
36 #include <asm/atomic.h>
37 #include <asm/mathemu.h>
38 #include <asm/cpcmd.h>
39 #include <asm/s390_ext.h>
40 #include <asm/lowcore.h>
41 #include <asm/debug.h>
42
43 /* Called from entry.S only */
44 extern void handle_per_exception(struct pt_regs *regs);
45
46 typedef void pgm_check_handler_t(struct pt_regs *, long);
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_pseudo_page_fault;
60 #ifdef CONFIG_PFAULT
61 extern int pfault_init(void);
62 extern void pfault_fini(void);
63 extern void pfault_interrupt(struct pt_regs *regs, __u16 error_code);
64 static ext_int_info_t ext_int_pfault;
65 #endif
66 extern pgm_check_handler_t do_monitor_call;
67
68 #define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
69
70 #ifndef CONFIG_ARCH_S390X
71 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
72 static int kstack_depth_to_print = 12;
73 #else /* CONFIG_ARCH_S390X */
74 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
75 static int kstack_depth_to_print = 20;
76 #endif /* CONFIG_ARCH_S390X */
77
78 /*
79  * For show_trace we have tree different stack to consider:
80  *   - the panic stack which is used if the kernel stack has overflown
81  *   - the asynchronous interrupt stack (cpu related)
82  *   - the synchronous kernel stack (process related)
83  * The stack trace can start at any of the three stack and can potentially
84  * touch all of them. The order is: panic stack, async stack, sync stack.
85  */
86 static unsigned long
87 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
88 {
89         struct stack_frame *sf;
90         struct pt_regs *regs;
91
92         while (1) {
93                 sp = sp & PSW_ADDR_INSN;
94                 if (sp < low || sp > high - sizeof(*sf))
95                         return sp;
96                 sf = (struct stack_frame *) sp;
97                 printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
98                 print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
99                 /* Follow the backchain. */
100                 while (1) {
101                         low = sp;
102                         sp = sf->back_chain & PSW_ADDR_INSN;
103                         if (!sp)
104                                 break;
105                         if (sp <= low || sp > high - sizeof(*sf))
106                                 return sp;
107                         sf = (struct stack_frame *) sp;
108                         printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
109                         print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
110                 }
111                 /* Zero backchain detected, check for interrupt frame. */
112                 sp = (unsigned long) (sf + 1);
113                 if (sp <= low || sp > high - sizeof(*regs))
114                         return sp;
115                 regs = (struct pt_regs *) sp;
116                 printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
117                 print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
118                 low = sp;
119                 sp = regs->gprs[15];
120         }
121 }
122
123 void show_trace(struct task_struct *task, unsigned long * stack)
124 {
125         register unsigned long __r15 asm ("15");
126         unsigned long sp;
127
128         sp = (unsigned long) stack;
129         if (!sp)
130                 sp = task ? task->thread.ksp : __r15;
131         printk("Call Trace:\n");
132 #ifdef CONFIG_CHECK_STACK
133         sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
134                           S390_lowcore.panic_stack);
135 #endif
136         sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
137                           S390_lowcore.async_stack);
138         if (task)
139                 __show_trace(sp, (unsigned long) task->thread_info,
140                              (unsigned long) task->thread_info + THREAD_SIZE);
141         else
142                 __show_trace(sp, S390_lowcore.thread_info,
143                              S390_lowcore.thread_info + THREAD_SIZE);
144         printk("\n");
145 }
146
147 void show_stack(struct task_struct *task, unsigned long *sp)
148 {
149         register unsigned long * __r15 asm ("15");
150         unsigned long *stack;
151         int i;
152
153         // debugging aid: "show_stack(NULL);" prints the
154         // back trace for this cpu.
155
156         if (!sp)
157                 sp = task ? (unsigned long *) task->thread.ksp : __r15;
158
159         stack = sp;
160         for (i = 0; i < kstack_depth_to_print; i++) {
161                 if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
162                         break;
163                 if (i && ((i * sizeof (long) % 32) == 0))
164                         printk("\n       ");
165                 printk("%p ", (void *)*stack++);
166         }
167         printk("\n");
168         show_trace(task, sp);
169 }
170
171 /*
172  * The architecture-independent dump_stack generator
173  */
174 void dump_stack(void)
175 {
176         show_stack(0, 0);
177 }
178
179 EXPORT_SYMBOL(dump_stack);
180
181 void show_registers(struct pt_regs *regs)
182 {
183         mm_segment_t old_fs;
184         char *mode;
185         int i;
186
187         mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
188         printk("%s PSW : %p %p",
189                mode, (void *) regs->psw.mask,
190                (void *) regs->psw.addr);
191         print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
192         printk("%s GPRS: " FOURLONG, mode,
193                regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
194         printk("           " FOURLONG,
195                regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
196         printk("           " FOURLONG,
197                regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
198         printk("           " FOURLONG,
199                regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
200
201 #if 0
202         /* FIXME: this isn't needed any more but it changes the ksymoops
203          * input. To remove or not to remove ... */
204         save_access_regs(regs->acrs);
205         printk("%s ACRS: %08x %08x %08x %08x\n", mode,
206                regs->acrs[0], regs->acrs[1], regs->acrs[2], regs->acrs[3]);
207         printk("           %08x %08x %08x %08x\n",
208                regs->acrs[4], regs->acrs[5], regs->acrs[6], regs->acrs[7]);
209         printk("           %08x %08x %08x %08x\n",
210                regs->acrs[8], regs->acrs[9], regs->acrs[10], regs->acrs[11]);
211         printk("           %08x %08x %08x %08x\n",
212                regs->acrs[12], regs->acrs[13], regs->acrs[14], regs->acrs[15]);
213 #endif
214
215         /*
216          * Print the first 20 byte of the instruction stream at the
217          * time of the fault.
218          */
219         old_fs = get_fs();
220         if (regs->psw.mask & PSW_MASK_PSTATE)
221                 set_fs(USER_DS);
222         else
223                 set_fs(KERNEL_DS);
224         printk("%s Code: ", mode);
225         for (i = 0; i < 20; i++) {
226                 unsigned char c;
227                 if (__get_user(c, (char __user *)(regs->psw.addr + i))) {
228                         printk(" Bad PSW.");
229                         break;
230                 }
231                 printk("%02x ", c);
232         }
233         set_fs(old_fs);
234
235         printk("\n");
236 }       
237
238 /* This is called from fs/proc/array.c */
239 char *task_show_regs(struct task_struct *task, char *buffer)
240 {
241         struct pt_regs *regs;
242
243         regs = __KSTK_PTREGS(task);
244         buffer += sprintf(buffer, "task: %p, ksp: %p\n",
245                        task, (void *)task->thread.ksp);
246         buffer += sprintf(buffer, "User PSW : %p %p\n",
247                        (void *) regs->psw.mask, (void *)regs->psw.addr);
248
249         buffer += sprintf(buffer, "User GPRS: " FOURLONG,
250                           regs->gprs[0], regs->gprs[1],
251                           regs->gprs[2], regs->gprs[3]);
252         buffer += sprintf(buffer, "           " FOURLONG,
253                           regs->gprs[4], regs->gprs[5],
254                           regs->gprs[6], regs->gprs[7]);
255         buffer += sprintf(buffer, "           " FOURLONG,
256                           regs->gprs[8], regs->gprs[9],
257                           regs->gprs[10], regs->gprs[11]);
258         buffer += sprintf(buffer, "           " FOURLONG,
259                           regs->gprs[12], regs->gprs[13],
260                           regs->gprs[14], regs->gprs[15]);
261         buffer += sprintf(buffer, "User ACRS: %08x %08x %08x %08x\n",
262                           task->thread.acrs[0], task->thread.acrs[1],
263                           task->thread.acrs[2], task->thread.acrs[3]);
264         buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
265                           task->thread.acrs[4], task->thread.acrs[5],
266                           task->thread.acrs[6], task->thread.acrs[7]);
267         buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
268                           task->thread.acrs[8], task->thread.acrs[9],
269                           task->thread.acrs[10], task->thread.acrs[11]);
270         buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
271                           task->thread.acrs[12], task->thread.acrs[13],
272                           task->thread.acrs[14], task->thread.acrs[15]);
273         return buffer;
274 }
275
276 DEFINE_SPINLOCK(die_lock);
277
278 void die(const char * str, struct pt_regs * regs, long err)
279 {
280         static int die_counter;
281
282         debug_stop_all();
283         console_verbose();
284         spin_lock_irq(&die_lock);
285         bust_spinlocks(1);
286         printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
287         show_regs(regs);
288         bust_spinlocks(0);
289         spin_unlock_irq(&die_lock);
290         if (in_interrupt())
291                 panic("Fatal exception in interrupt");
292         if (panic_on_oops)
293                 panic("Fatal exception: panic_on_oops");
294         do_exit(SIGSEGV);
295 }
296
297 static void inline
298 report_user_fault(long interruption_code, struct pt_regs *regs)
299 {
300 #if defined(CONFIG_SYSCTL)
301         if (!sysctl_userprocess_debug)
302                 return;
303 #endif
304 #if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG)
305         printk("User process fault: interruption code 0x%lX\n",
306                interruption_code);
307         show_regs(regs);
308 #endif
309 }
310
311 static void inline do_trap(long interruption_code, int signr, char *str,
312                            struct pt_regs *regs, siginfo_t *info)
313 {
314         /*
315          * We got all needed information from the lowcore and can
316          * now safely switch on interrupts.
317          */
318         if (regs->psw.mask & PSW_MASK_PSTATE)
319                 local_irq_enable();
320
321         if (regs->psw.mask & PSW_MASK_PSTATE) {
322                 struct task_struct *tsk = current;
323
324                 tsk->thread.trap_no = interruption_code & 0xffff;
325                 force_sig_info(signr, info, tsk);
326                 report_user_fault(interruption_code, regs);
327         } else {
328                 const struct exception_table_entry *fixup;
329                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
330                 if (fixup)
331                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
332                 else
333                         die(str, regs, interruption_code);
334         }
335 }
336
337 static inline void *get_check_address(struct pt_regs *regs)
338 {
339         return (void *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
340 }
341
342 void do_single_step(struct pt_regs *regs)
343 {
344         if ((current->ptrace & PT_PTRACED) != 0)
345                 force_sig(SIGTRAP, current);
346 }
347
348 asmlinkage void
349 default_trap_handler(struct pt_regs * regs, long interruption_code)
350 {
351         if (regs->psw.mask & PSW_MASK_PSTATE) {
352                 local_irq_enable();
353                 do_exit(SIGSEGV);
354                 report_user_fault(interruption_code, regs);
355         } else
356                 die("Unknown program exception", regs, interruption_code);
357 }
358
359 #define DO_ERROR_INFO(signr, str, name, sicode, siaddr) \
360 asmlinkage void name(struct pt_regs * regs, long interruption_code) \
361 { \
362         siginfo_t info; \
363         info.si_signo = signr; \
364         info.si_errno = 0; \
365         info.si_code = sicode; \
366         info.si_addr = (void *)siaddr; \
367         do_trap(interruption_code, signr, str, regs, &info); \
368 }
369
370 DO_ERROR_INFO(SIGILL, "addressing exception", addressing_exception,
371               ILL_ILLADR, get_check_address(regs))
372 DO_ERROR_INFO(SIGILL,  "execute exception", execute_exception,
373               ILL_ILLOPN, get_check_address(regs))
374 DO_ERROR_INFO(SIGFPE,  "fixpoint divide exception", divide_exception,
375               FPE_INTDIV, get_check_address(regs))
376 DO_ERROR_INFO(SIGFPE,  "fixpoint overflow exception", overflow_exception,
377               FPE_INTOVF, get_check_address(regs))
378 DO_ERROR_INFO(SIGFPE,  "HFP overflow exception", hfp_overflow_exception,
379               FPE_FLTOVF, get_check_address(regs))
380 DO_ERROR_INFO(SIGFPE,  "HFP underflow exception", hfp_underflow_exception,
381               FPE_FLTUND, get_check_address(regs))
382 DO_ERROR_INFO(SIGFPE,  "HFP significance exception", hfp_significance_exception,
383               FPE_FLTRES, get_check_address(regs))
384 DO_ERROR_INFO(SIGFPE,  "HFP divide exception", hfp_divide_exception,
385               FPE_FLTDIV, get_check_address(regs))
386 DO_ERROR_INFO(SIGFPE,  "HFP square root exception", hfp_sqrt_exception,
387               FPE_FLTINV, get_check_address(regs))
388 DO_ERROR_INFO(SIGILL,  "operand exception", operand_exception,
389               ILL_ILLOPN, get_check_address(regs))
390 DO_ERROR_INFO(SIGILL,  "privileged operation", privileged_op,
391               ILL_PRVOPC, get_check_address(regs))
392 DO_ERROR_INFO(SIGILL,  "special operation exception", special_op_exception,
393               ILL_ILLOPN, get_check_address(regs))
394 DO_ERROR_INFO(SIGILL,  "translation exception", translation_exception,
395               ILL_ILLOPN, get_check_address(regs))
396
397 static inline void
398 do_fp_trap(struct pt_regs *regs, void *location,
399            int fpc, long interruption_code)
400 {
401         siginfo_t si;
402
403         si.si_signo = SIGFPE;
404         si.si_errno = 0;
405         si.si_addr = location;
406         si.si_code = 0;
407         /* FPC[2] is Data Exception Code */
408         if ((fpc & 0x00000300) == 0) {
409                 /* bits 6 and 7 of DXC are 0 iff IEEE exception */
410                 if (fpc & 0x8000) /* invalid fp operation */
411                         si.si_code = FPE_FLTINV;
412                 else if (fpc & 0x4000) /* div by 0 */
413                         si.si_code = FPE_FLTDIV;
414                 else if (fpc & 0x2000) /* overflow */
415                         si.si_code = FPE_FLTOVF;
416                 else if (fpc & 0x1000) /* underflow */
417                         si.si_code = FPE_FLTUND;
418                 else if (fpc & 0x0800) /* inexact */
419                         si.si_code = FPE_FLTRES;
420         }
421         current->thread.ieee_instruction_pointer = (addr_t) location;
422         do_trap(interruption_code, SIGFPE,
423                 "floating point exception", regs, &si);
424 }
425
426 asmlinkage void illegal_op(struct pt_regs * regs, long interruption_code)
427 {
428         siginfo_t info;
429         __u8 opcode[6];
430         __u16 *location;
431         int signal = 0;
432
433         location = (__u16 *) get_check_address(regs);
434
435         /*
436          * We got all needed information from the lowcore and can
437          * now safely switch on interrupts.
438          */
439         if (regs->psw.mask & PSW_MASK_PSTATE)
440                 local_irq_enable();
441
442         if (regs->psw.mask & PSW_MASK_PSTATE) {
443                 get_user(*((__u16 *) opcode), (__u16 __user *) location);
444                 if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
445                         if (current->ptrace & PT_PTRACED)
446                                 force_sig(SIGTRAP, current);
447                         else
448                                 signal = SIGILL;
449 #ifdef CONFIG_MATHEMU
450                 } else if (opcode[0] == 0xb3) {
451                         get_user(*((__u16 *) (opcode+2)), location+1);
452                         signal = math_emu_b3(opcode, regs);
453                 } else if (opcode[0] == 0xed) {
454                         get_user(*((__u32 *) (opcode+2)),
455                                  (__u32 *)(location+1));
456                         signal = math_emu_ed(opcode, regs);
457                 } else if (*((__u16 *) opcode) == 0xb299) {
458                         get_user(*((__u16 *) (opcode+2)), location+1);
459                         signal = math_emu_srnm(opcode, regs);
460                 } else if (*((__u16 *) opcode) == 0xb29c) {
461                         get_user(*((__u16 *) (opcode+2)), location+1);
462                         signal = math_emu_stfpc(opcode, regs);
463                 } else if (*((__u16 *) opcode) == 0xb29d) {
464                         get_user(*((__u16 *) (opcode+2)), location+1);
465                         signal = math_emu_lfpc(opcode, regs);
466 #endif
467                 } else
468                         signal = SIGILL;
469         } else
470                 signal = SIGILL;
471
472 #ifdef CONFIG_MATHEMU
473         if (signal == SIGFPE)
474                 do_fp_trap(regs, location,
475                            current->thread.fp_regs.fpc, interruption_code);
476         else if (signal == SIGSEGV) {
477                 info.si_signo = signal;
478                 info.si_errno = 0;
479                 info.si_code = SEGV_MAPERR;
480                 info.si_addr = (void *) location;
481                 do_trap(interruption_code, signal,
482                         "user address fault", regs, &info);
483         } else
484 #endif
485         if (signal) {
486                 info.si_signo = signal;
487                 info.si_errno = 0;
488                 info.si_code = ILL_ILLOPC;
489                 info.si_addr = (void *) location;
490                 do_trap(interruption_code, signal,
491                         "illegal operation", regs, &info);
492         }
493 }
494
495
496 #ifdef CONFIG_MATHEMU
497 asmlinkage void 
498 specification_exception(struct pt_regs * regs, long interruption_code)
499 {
500         __u8 opcode[6];
501         __u16 *location = NULL;
502         int signal = 0;
503
504         location = (__u16 *) get_check_address(regs);
505
506         /*
507          * We got all needed information from the lowcore and can
508          * now safely switch on interrupts.
509          */
510         if (regs->psw.mask & PSW_MASK_PSTATE)
511                 local_irq_enable();
512
513         if (regs->psw.mask & PSW_MASK_PSTATE) {
514                 get_user(*((__u16 *) opcode), location);
515                 switch (opcode[0]) {
516                 case 0x28: /* LDR Rx,Ry   */
517                         signal = math_emu_ldr(opcode);
518                         break;
519                 case 0x38: /* LER Rx,Ry   */
520                         signal = math_emu_ler(opcode);
521                         break;
522                 case 0x60: /* STD R,D(X,B) */
523                         get_user(*((__u16 *) (opcode+2)), location+1);
524                         signal = math_emu_std(opcode, regs);
525                         break;
526                 case 0x68: /* LD R,D(X,B) */
527                         get_user(*((__u16 *) (opcode+2)), location+1);
528                         signal = math_emu_ld(opcode, regs);
529                         break;
530                 case 0x70: /* STE R,D(X,B) */
531                         get_user(*((__u16 *) (opcode+2)), location+1);
532                         signal = math_emu_ste(opcode, regs);
533                         break;
534                 case 0x78: /* LE R,D(X,B) */
535                         get_user(*((__u16 *) (opcode+2)), location+1);
536                         signal = math_emu_le(opcode, regs);
537                         break;
538                 default:
539                         signal = SIGILL;
540                         break;
541                 }
542         } else
543                 signal = SIGILL;
544
545         if (signal == SIGFPE)
546                 do_fp_trap(regs, location,
547                            current->thread.fp_regs.fpc, interruption_code);
548         else if (signal) {
549                 siginfo_t info;
550                 info.si_signo = signal;
551                 info.si_errno = 0;
552                 info.si_code = ILL_ILLOPN;
553                 info.si_addr = location;
554                 do_trap(interruption_code, signal, 
555                         "specification exception", regs, &info);
556         }
557 }
558 #else
559 DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
560               ILL_ILLOPN, get_check_address(regs));
561 #endif
562
563 asmlinkage void data_exception(struct pt_regs * regs, long interruption_code)
564 {
565         __u16 *location;
566         int signal = 0;
567
568         location = (__u16 *) get_check_address(regs);
569
570         /*
571          * We got all needed information from the lowcore and can
572          * now safely switch on interrupts.
573          */
574         if (regs->psw.mask & PSW_MASK_PSTATE)
575                 local_irq_enable();
576
577         if (MACHINE_HAS_IEEE)
578                 __asm__ volatile ("stfpc %0\n\t" 
579                                   : "=m" (current->thread.fp_regs.fpc));
580
581 #ifdef CONFIG_MATHEMU
582         else if (regs->psw.mask & PSW_MASK_PSTATE) {
583                 __u8 opcode[6];
584                 get_user(*((__u16 *) opcode), location);
585                 switch (opcode[0]) {
586                 case 0x28: /* LDR Rx,Ry   */
587                         signal = math_emu_ldr(opcode);
588                         break;
589                 case 0x38: /* LER Rx,Ry   */
590                         signal = math_emu_ler(opcode);
591                         break;
592                 case 0x60: /* STD R,D(X,B) */
593                         get_user(*((__u16 *) (opcode+2)), location+1);
594                         signal = math_emu_std(opcode, regs);
595                         break;
596                 case 0x68: /* LD R,D(X,B) */
597                         get_user(*((__u16 *) (opcode+2)), location+1);
598                         signal = math_emu_ld(opcode, regs);
599                         break;
600                 case 0x70: /* STE R,D(X,B) */
601                         get_user(*((__u16 *) (opcode+2)), location+1);
602                         signal = math_emu_ste(opcode, regs);
603                         break;
604                 case 0x78: /* LE R,D(X,B) */
605                         get_user(*((__u16 *) (opcode+2)), location+1);
606                         signal = math_emu_le(opcode, regs);
607                         break;
608                 case 0xb3:
609                         get_user(*((__u16 *) (opcode+2)), location+1);
610                         signal = math_emu_b3(opcode, regs);
611                         break;
612                 case 0xed:
613                         get_user(*((__u32 *) (opcode+2)),
614                                  (__u32 *)(location+1));
615                         signal = math_emu_ed(opcode, regs);
616                         break;
617                 case 0xb2:
618                         if (opcode[1] == 0x99) {
619                                 get_user(*((__u16 *) (opcode+2)), location+1);
620                                 signal = math_emu_srnm(opcode, regs);
621                         } else if (opcode[1] == 0x9c) {
622                                 get_user(*((__u16 *) (opcode+2)), location+1);
623                                 signal = math_emu_stfpc(opcode, regs);
624                         } else if (opcode[1] == 0x9d) {
625                                 get_user(*((__u16 *) (opcode+2)), location+1);
626                                 signal = math_emu_lfpc(opcode, regs);
627                         } else
628                                 signal = SIGILL;
629                         break;
630                 default:
631                         signal = SIGILL;
632                         break;
633                 }
634         }
635 #endif 
636         if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
637                 signal = SIGFPE;
638         else
639                 signal = SIGILL;
640         if (signal == SIGFPE)
641                 do_fp_trap(regs, location,
642                            current->thread.fp_regs.fpc, interruption_code);
643         else if (signal) {
644                 siginfo_t info;
645                 info.si_signo = signal;
646                 info.si_errno = 0;
647                 info.si_code = ILL_ILLOPN;
648                 info.si_addr = location;
649                 do_trap(interruption_code, signal, 
650                         "data exception", regs, &info);
651         }
652 }
653
654 asmlinkage void space_switch_exception(struct pt_regs * regs, long int_code)
655 {
656         siginfo_t info;
657
658         /* Set user psw back to home space mode. */
659         if (regs->psw.mask & PSW_MASK_PSTATE)
660                 regs->psw.mask |= PSW_ASC_HOME;
661         /* Send SIGILL. */
662         info.si_signo = SIGILL;
663         info.si_errno = 0;
664         info.si_code = ILL_PRVOPC;
665         info.si_addr = get_check_address(regs);
666         do_trap(int_code, SIGILL, "space switch event", regs, &info);
667 }
668
669 asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
670 {
671         bust_spinlocks(1);
672         printk("Kernel stack overflow.\n");
673         show_regs(regs);
674         bust_spinlocks(0);
675         panic("Corrupt kernel stack, can't continue.");
676 }
677
678
679 /* init is done in lowcore.S and head.S */
680
681 void __init trap_init(void)
682 {
683         int i;
684
685         for (i = 0; i < 128; i++)
686           pgm_check_table[i] = &default_trap_handler;
687         pgm_check_table[1] = &illegal_op;
688         pgm_check_table[2] = &privileged_op;
689         pgm_check_table[3] = &execute_exception;
690         pgm_check_table[4] = &do_protection_exception;
691         pgm_check_table[5] = &addressing_exception;
692         pgm_check_table[6] = &specification_exception;
693         pgm_check_table[7] = &data_exception;
694         pgm_check_table[8] = &overflow_exception;
695         pgm_check_table[9] = &divide_exception;
696         pgm_check_table[0x0A] = &overflow_exception;
697         pgm_check_table[0x0B] = &divide_exception;
698         pgm_check_table[0x0C] = &hfp_overflow_exception;
699         pgm_check_table[0x0D] = &hfp_underflow_exception;
700         pgm_check_table[0x0E] = &hfp_significance_exception;
701         pgm_check_table[0x0F] = &hfp_divide_exception;
702         pgm_check_table[0x10] = &do_dat_exception;
703         pgm_check_table[0x11] = &do_dat_exception;
704         pgm_check_table[0x12] = &translation_exception;
705         pgm_check_table[0x13] = &special_op_exception;
706 #ifndef CONFIG_ARCH_S390X
707         pgm_check_table[0x14] = &do_pseudo_page_fault;
708 #else /* CONFIG_ARCH_S390X */
709         pgm_check_table[0x38] = &do_dat_exception;
710         pgm_check_table[0x39] = &do_dat_exception;
711         pgm_check_table[0x3A] = &do_dat_exception;
712         pgm_check_table[0x3B] = &do_dat_exception;
713 #endif /* CONFIG_ARCH_S390X */
714         pgm_check_table[0x15] = &operand_exception;
715         pgm_check_table[0x1C] = &space_switch_exception;
716         pgm_check_table[0x1D] = &hfp_sqrt_exception;
717         pgm_check_table[0x40] = &do_monitor_call;
718
719         if (MACHINE_IS_VM) {
720                 /*
721                  * First try to get pfault pseudo page faults going.
722                  * If this isn't available turn on pagex page faults.
723                  */
724 #ifdef CONFIG_PFAULT
725                 /* request the 0x2603 external interrupt */
726                 if (register_early_external_interrupt(0x2603, pfault_interrupt,
727                                                       &ext_int_pfault) != 0)
728                         panic("Couldn't request external interrupt 0x2603");
729
730                 if (pfault_init() == 0) 
731                         return;
732                 
733                 /* Tough luck, no pfault. */
734                 unregister_early_external_interrupt(0x2603, pfault_interrupt,
735                                                     &ext_int_pfault);
736 #endif
737 #ifndef CONFIG_ARCH_S390X
738                 cpcmd("SET PAGEX ON", NULL, 0, NULL);
739 #endif
740         }
741 }