Merge branches 'release', 'bugzilla-6217', 'bugzilla-6629', 'bugzilla-6933', 'bugzill...
[linux-2.6] / 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 <linux/utsname.h>
35 #include <asm/system.h>
36 #include <asm/uaccess.h>
37 #include <asm/io.h>
38 #include <asm/atomic.h>
39 #include <asm/mathemu.h>
40 #include <asm/cpcmd.h>
41 #include <asm/s390_ext.h>
42 #include <asm/lowcore.h>
43 #include <asm/debug.h>
44
45 /* Called from entry.S only */
46 extern void handle_per_exception(struct pt_regs *regs);
47
48 typedef void pgm_check_handler_t(struct pt_regs *, long);
49 pgm_check_handler_t *pgm_check_table[128];
50
51 #ifdef CONFIG_SYSCTL
52 #ifdef CONFIG_PROCESS_DEBUG
53 int sysctl_userprocess_debug = 1;
54 #else
55 int sysctl_userprocess_debug = 0;
56 #endif
57 #endif
58
59 extern pgm_check_handler_t do_protection_exception;
60 extern pgm_check_handler_t do_dat_exception;
61 extern pgm_check_handler_t do_monitor_call;
62
63 #define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
64
65 #ifndef CONFIG_64BIT
66 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
67 static int kstack_depth_to_print = 12;
68 #else /* CONFIG_64BIT */
69 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
70 static int kstack_depth_to_print = 20;
71 #endif /* CONFIG_64BIT */
72
73 /*
74  * For show_trace we have tree different stack to consider:
75  *   - the panic stack which is used if the kernel stack has overflown
76  *   - the asynchronous interrupt stack (cpu related)
77  *   - the synchronous kernel stack (process related)
78  * The stack trace can start at any of the three stack and can potentially
79  * touch all of them. The order is: panic stack, async stack, sync stack.
80  */
81 static unsigned long
82 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
83 {
84         struct stack_frame *sf;
85         struct pt_regs *regs;
86
87         while (1) {
88                 sp = sp & PSW_ADDR_INSN;
89                 if (sp < low || sp > high - sizeof(*sf))
90                         return sp;
91                 sf = (struct stack_frame *) sp;
92                 printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
93                 print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
94                 /* Follow the backchain. */
95                 while (1) {
96                         low = sp;
97                         sp = sf->back_chain & PSW_ADDR_INSN;
98                         if (!sp)
99                                 break;
100                         if (sp <= low || sp > high - sizeof(*sf))
101                                 return sp;
102                         sf = (struct stack_frame *) sp;
103                         printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
104                         print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
105                 }
106                 /* Zero backchain detected, check for interrupt frame. */
107                 sp = (unsigned long) (sf + 1);
108                 if (sp <= low || sp > high - sizeof(*regs))
109                         return sp;
110                 regs = (struct pt_regs *) sp;
111                 printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
112                 print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
113                 low = sp;
114                 sp = regs->gprs[15];
115         }
116 }
117
118 void show_trace(struct task_struct *task, unsigned long *stack)
119 {
120         register unsigned long __r15 asm ("15");
121         unsigned long sp;
122
123         sp = (unsigned long) stack;
124         if (!sp)
125                 sp = task ? task->thread.ksp : __r15;
126         printk("Call Trace:\n");
127 #ifdef CONFIG_CHECK_STACK
128         sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
129                           S390_lowcore.panic_stack);
130 #endif
131         sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
132                           S390_lowcore.async_stack);
133         if (task)
134                 __show_trace(sp, (unsigned long) task_stack_page(task),
135                              (unsigned long) task_stack_page(task) + THREAD_SIZE);
136         else
137                 __show_trace(sp, S390_lowcore.thread_info,
138                              S390_lowcore.thread_info + THREAD_SIZE);
139         printk("\n");
140         if (!task)
141                 task = current;
142         debug_show_held_locks(task);
143 }
144
145 void show_stack(struct task_struct *task, unsigned long *sp)
146 {
147         register unsigned long * __r15 asm ("15");
148         unsigned long *stack;
149         int i;
150
151         if (!sp)
152                 stack = task ? (unsigned long *) task->thread.ksp : __r15;
153         else
154                 stack = sp;
155
156         for (i = 0; i < kstack_depth_to_print; i++) {
157                 if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
158                         break;
159                 if (i && ((i * sizeof (long) % 32) == 0))
160                         printk("\n       ");
161                 printk("%p ", (void *)*stack++);
162         }
163         printk("\n");
164         show_trace(task, sp);
165 }
166
167 /*
168  * The architecture-independent dump_stack generator
169  */
170 void dump_stack(void)
171 {
172         printk("CPU: %d %s %s %.*s\n",
173                task_thread_info(current)->cpu, print_tainted(),
174                init_utsname()->release,
175                (int)strcspn(init_utsname()->version, " "),
176                init_utsname()->version);
177         printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
178                current->comm, current->pid, current,
179                (void *) current->thread.ksp);
180         show_stack(NULL, NULL);
181 }
182 EXPORT_SYMBOL(dump_stack);
183
184 static inline int mask_bits(struct pt_regs *regs, unsigned long bits)
185 {
186         return (regs->psw.mask & bits) / ((~bits + 1) & bits);
187 }
188
189 void show_registers(struct pt_regs *regs)
190 {
191         char *mode;
192
193         mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
194         printk("%s PSW : %p %p",
195                mode, (void *) regs->psw.mask,
196                (void *) regs->psw.addr);
197         print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
198         printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
199                "P:%x AS:%x CC:%x PM:%x", mask_bits(regs, PSW_MASK_PER),
200                mask_bits(regs, PSW_MASK_DAT), mask_bits(regs, PSW_MASK_IO),
201                mask_bits(regs, PSW_MASK_EXT), mask_bits(regs, PSW_MASK_KEY),
202                mask_bits(regs, PSW_MASK_MCHECK), mask_bits(regs, PSW_MASK_WAIT),
203                mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC),
204                mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM));
205 #ifdef CONFIG_64BIT
206         printk(" EA:%x", mask_bits(regs, PSW_BASE_BITS));
207 #endif
208         printk("\n%s GPRS: " FOURLONG, mode,
209                regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
210         printk("           " FOURLONG,
211                regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
212         printk("           " FOURLONG,
213                regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
214         printk("           " FOURLONG,
215                regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
216
217         show_code(regs);
218 }       
219
220 /* This is called from fs/proc/array.c */
221 char *task_show_regs(struct task_struct *task, char *buffer)
222 {
223         struct pt_regs *regs;
224
225         regs = task_pt_regs(task);
226         buffer += sprintf(buffer, "task: %p, ksp: %p\n",
227                        task, (void *)task->thread.ksp);
228         buffer += sprintf(buffer, "User PSW : %p %p\n",
229                        (void *) regs->psw.mask, (void *)regs->psw.addr);
230
231         buffer += sprintf(buffer, "User GPRS: " FOURLONG,
232                           regs->gprs[0], regs->gprs[1],
233                           regs->gprs[2], regs->gprs[3]);
234         buffer += sprintf(buffer, "           " FOURLONG,
235                           regs->gprs[4], regs->gprs[5],
236                           regs->gprs[6], regs->gprs[7]);
237         buffer += sprintf(buffer, "           " FOURLONG,
238                           regs->gprs[8], regs->gprs[9],
239                           regs->gprs[10], regs->gprs[11]);
240         buffer += sprintf(buffer, "           " FOURLONG,
241                           regs->gprs[12], regs->gprs[13],
242                           regs->gprs[14], regs->gprs[15]);
243         buffer += sprintf(buffer, "User ACRS: %08x %08x %08x %08x\n",
244                           task->thread.acrs[0], task->thread.acrs[1],
245                           task->thread.acrs[2], task->thread.acrs[3]);
246         buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
247                           task->thread.acrs[4], task->thread.acrs[5],
248                           task->thread.acrs[6], task->thread.acrs[7]);
249         buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
250                           task->thread.acrs[8], task->thread.acrs[9],
251                           task->thread.acrs[10], task->thread.acrs[11]);
252         buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
253                           task->thread.acrs[12], task->thread.acrs[13],
254                           task->thread.acrs[14], task->thread.acrs[15]);
255         return buffer;
256 }
257
258 static DEFINE_SPINLOCK(die_lock);
259
260 void die(const char * str, struct pt_regs * regs, long err)
261 {
262         static int die_counter;
263
264         oops_enter();
265         debug_stop_all();
266         console_verbose();
267         spin_lock_irq(&die_lock);
268         bust_spinlocks(1);
269         printk("%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
270 #ifdef CONFIG_PREEMPT
271         printk("PREEMPT ");
272 #endif
273 #ifdef CONFIG_SMP
274         printk("SMP ");
275 #endif
276 #ifdef CONFIG_DEBUG_PAGEALLOC
277         printk("DEBUG_PAGEALLOC");
278 #endif
279         printk("\n");
280         notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
281         show_regs(regs);
282         bust_spinlocks(0);
283         add_taint(TAINT_DIE);
284         spin_unlock_irq(&die_lock);
285         if (in_interrupt())
286                 panic("Fatal exception in interrupt");
287         if (panic_on_oops)
288                 panic("Fatal exception: panic_on_oops");
289         oops_exit();
290         do_exit(SIGSEGV);
291 }
292
293 static void inline
294 report_user_fault(long interruption_code, struct pt_regs *regs)
295 {
296 #if defined(CONFIG_SYSCTL)
297         if (!sysctl_userprocess_debug)
298                 return;
299 #endif
300 #if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG)
301         printk("User process fault: interruption code 0x%lX\n",
302                interruption_code);
303         show_regs(regs);
304 #endif
305 }
306
307 int is_valid_bugaddr(unsigned long addr)
308 {
309         return 1;
310 }
311
312 static void __kprobes inline do_trap(long interruption_code, int signr,
313                                         char *str, struct pt_regs *regs,
314                                         siginfo_t *info)
315 {
316         /*
317          * We got all needed information from the lowcore and can
318          * now safely switch on interrupts.
319          */
320         if (regs->psw.mask & PSW_MASK_PSTATE)
321                 local_irq_enable();
322
323         if (notify_die(DIE_TRAP, str, regs, interruption_code,
324                                 interruption_code, signr) == NOTIFY_STOP)
325                 return;
326
327         if (regs->psw.mask & PSW_MASK_PSTATE) {
328                 struct task_struct *tsk = current;
329
330                 tsk->thread.trap_no = interruption_code & 0xffff;
331                 force_sig_info(signr, info, tsk);
332                 report_user_fault(interruption_code, regs);
333         } else {
334                 const struct exception_table_entry *fixup;
335                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
336                 if (fixup)
337                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
338                 else {
339                         enum bug_trap_type btt;
340
341                         btt = report_bug(regs->psw.addr & PSW_ADDR_INSN, regs);
342                         if (btt == BUG_TRAP_TYPE_WARN)
343                                 return;
344                         die(str, regs, interruption_code);
345                 }
346         }
347 }
348
349 static inline void __user *get_check_address(struct pt_regs *regs)
350 {
351         return (void __user *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
352 }
353
354 void __kprobes do_single_step(struct pt_regs *regs)
355 {
356         if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0,
357                                         SIGTRAP) == NOTIFY_STOP){
358                 return;
359         }
360         if ((current->ptrace & PT_PTRACED) != 0)
361                 force_sig(SIGTRAP, current);
362 }
363
364 static void default_trap_handler(struct pt_regs * regs, long interruption_code)
365 {
366         if (regs->psw.mask & PSW_MASK_PSTATE) {
367                 local_irq_enable();
368                 do_exit(SIGSEGV);
369                 report_user_fault(interruption_code, regs);
370         } else
371                 die("Unknown program exception", regs, interruption_code);
372 }
373
374 #define DO_ERROR_INFO(signr, str, name, sicode, siaddr) \
375 static void name(struct pt_regs * regs, long interruption_code) \
376 { \
377         siginfo_t info; \
378         info.si_signo = signr; \
379         info.si_errno = 0; \
380         info.si_code = sicode; \
381         info.si_addr = siaddr; \
382         do_trap(interruption_code, signr, str, regs, &info); \
383 }
384
385 DO_ERROR_INFO(SIGILL, "addressing exception", addressing_exception,
386               ILL_ILLADR, get_check_address(regs))
387 DO_ERROR_INFO(SIGILL,  "execute exception", execute_exception,
388               ILL_ILLOPN, get_check_address(regs))
389 DO_ERROR_INFO(SIGFPE,  "fixpoint divide exception", divide_exception,
390               FPE_INTDIV, get_check_address(regs))
391 DO_ERROR_INFO(SIGFPE,  "fixpoint overflow exception", overflow_exception,
392               FPE_INTOVF, get_check_address(regs))
393 DO_ERROR_INFO(SIGFPE,  "HFP overflow exception", hfp_overflow_exception,
394               FPE_FLTOVF, get_check_address(regs))
395 DO_ERROR_INFO(SIGFPE,  "HFP underflow exception", hfp_underflow_exception,
396               FPE_FLTUND, get_check_address(regs))
397 DO_ERROR_INFO(SIGFPE,  "HFP significance exception", hfp_significance_exception,
398               FPE_FLTRES, get_check_address(regs))
399 DO_ERROR_INFO(SIGFPE,  "HFP divide exception", hfp_divide_exception,
400               FPE_FLTDIV, get_check_address(regs))
401 DO_ERROR_INFO(SIGFPE,  "HFP square root exception", hfp_sqrt_exception,
402               FPE_FLTINV, get_check_address(regs))
403 DO_ERROR_INFO(SIGILL,  "operand exception", operand_exception,
404               ILL_ILLOPN, get_check_address(regs))
405 DO_ERROR_INFO(SIGILL,  "privileged operation", privileged_op,
406               ILL_PRVOPC, get_check_address(regs))
407 DO_ERROR_INFO(SIGILL,  "special operation exception", special_op_exception,
408               ILL_ILLOPN, get_check_address(regs))
409 DO_ERROR_INFO(SIGILL,  "translation exception", translation_exception,
410               ILL_ILLOPN, get_check_address(regs))
411
412 static inline void
413 do_fp_trap(struct pt_regs *regs, void __user *location,
414            int fpc, long interruption_code)
415 {
416         siginfo_t si;
417
418         si.si_signo = SIGFPE;
419         si.si_errno = 0;
420         si.si_addr = location;
421         si.si_code = 0;
422         /* FPC[2] is Data Exception Code */
423         if ((fpc & 0x00000300) == 0) {
424                 /* bits 6 and 7 of DXC are 0 iff IEEE exception */
425                 if (fpc & 0x8000) /* invalid fp operation */
426                         si.si_code = FPE_FLTINV;
427                 else if (fpc & 0x4000) /* div by 0 */
428                         si.si_code = FPE_FLTDIV;
429                 else if (fpc & 0x2000) /* overflow */
430                         si.si_code = FPE_FLTOVF;
431                 else if (fpc & 0x1000) /* underflow */
432                         si.si_code = FPE_FLTUND;
433                 else if (fpc & 0x0800) /* inexact */
434                         si.si_code = FPE_FLTRES;
435         }
436         current->thread.ieee_instruction_pointer = (addr_t) location;
437         do_trap(interruption_code, SIGFPE,
438                 "floating point exception", regs, &si);
439 }
440
441 static void illegal_op(struct pt_regs * regs, long interruption_code)
442 {
443         siginfo_t info;
444         __u8 opcode[6];
445         __u16 __user *location;
446         int signal = 0;
447
448         location = get_check_address(regs);
449
450         /*
451          * We got all needed information from the lowcore and can
452          * now safely switch on interrupts.
453          */
454         if (regs->psw.mask & PSW_MASK_PSTATE)
455                 local_irq_enable();
456
457         if (regs->psw.mask & PSW_MASK_PSTATE) {
458                 if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
459                         return;
460                 if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
461                         if (current->ptrace & PT_PTRACED)
462                                 force_sig(SIGTRAP, current);
463                         else
464                                 signal = SIGILL;
465 #ifdef CONFIG_MATHEMU
466                 } else if (opcode[0] == 0xb3) {
467                         if (get_user(*((__u16 *) (opcode+2)), location+1))
468                                 return;
469                         signal = math_emu_b3(opcode, regs);
470                 } else if (opcode[0] == 0xed) {
471                         if (get_user(*((__u32 *) (opcode+2)),
472                                      (__u32 __user *)(location+1)))
473                                 return;
474                         signal = math_emu_ed(opcode, regs);
475                 } else if (*((__u16 *) opcode) == 0xb299) {
476                         if (get_user(*((__u16 *) (opcode+2)), location+1))
477                                 return;
478                         signal = math_emu_srnm(opcode, regs);
479                 } else if (*((__u16 *) opcode) == 0xb29c) {
480                         if (get_user(*((__u16 *) (opcode+2)), location+1))
481                                 return;
482                         signal = math_emu_stfpc(opcode, regs);
483                 } else if (*((__u16 *) opcode) == 0xb29d) {
484                         if (get_user(*((__u16 *) (opcode+2)), location+1))
485                                 return;
486                         signal = math_emu_lfpc(opcode, regs);
487 #endif
488                 } else
489                         signal = SIGILL;
490         } else {
491                 /*
492                  * If we get an illegal op in kernel mode, send it through the
493                  * kprobes notifier. If kprobes doesn't pick it up, SIGILL
494                  */
495                 if (notify_die(DIE_BPT, "bpt", regs, interruption_code,
496                                3, SIGTRAP) != NOTIFY_STOP)
497                         signal = SIGILL;
498         }
499
500 #ifdef CONFIG_MATHEMU
501         if (signal == SIGFPE)
502                 do_fp_trap(regs, location,
503                            current->thread.fp_regs.fpc, interruption_code);
504         else if (signal == SIGSEGV) {
505                 info.si_signo = signal;
506                 info.si_errno = 0;
507                 info.si_code = SEGV_MAPERR;
508                 info.si_addr = (void __user *) location;
509                 do_trap(interruption_code, signal,
510                         "user address fault", regs, &info);
511         } else
512 #endif
513         if (signal) {
514                 info.si_signo = signal;
515                 info.si_errno = 0;
516                 info.si_code = ILL_ILLOPC;
517                 info.si_addr = (void __user *) location;
518                 do_trap(interruption_code, signal,
519                         "illegal operation", regs, &info);
520         }
521 }
522
523
524 #ifdef CONFIG_MATHEMU
525 asmlinkage void 
526 specification_exception(struct pt_regs * regs, long interruption_code)
527 {
528         __u8 opcode[6];
529         __u16 __user *location = NULL;
530         int signal = 0;
531
532         location = (__u16 __user *) get_check_address(regs);
533
534         /*
535          * We got all needed information from the lowcore and can
536          * now safely switch on interrupts.
537          */
538         if (regs->psw.mask & PSW_MASK_PSTATE)
539                 local_irq_enable();
540
541         if (regs->psw.mask & PSW_MASK_PSTATE) {
542                 get_user(*((__u16 *) opcode), location);
543                 switch (opcode[0]) {
544                 case 0x28: /* LDR Rx,Ry   */
545                         signal = math_emu_ldr(opcode);
546                         break;
547                 case 0x38: /* LER Rx,Ry   */
548                         signal = math_emu_ler(opcode);
549                         break;
550                 case 0x60: /* STD R,D(X,B) */
551                         get_user(*((__u16 *) (opcode+2)), location+1);
552                         signal = math_emu_std(opcode, regs);
553                         break;
554                 case 0x68: /* LD R,D(X,B) */
555                         get_user(*((__u16 *) (opcode+2)), location+1);
556                         signal = math_emu_ld(opcode, regs);
557                         break;
558                 case 0x70: /* STE R,D(X,B) */
559                         get_user(*((__u16 *) (opcode+2)), location+1);
560                         signal = math_emu_ste(opcode, regs);
561                         break;
562                 case 0x78: /* LE R,D(X,B) */
563                         get_user(*((__u16 *) (opcode+2)), location+1);
564                         signal = math_emu_le(opcode, regs);
565                         break;
566                 default:
567                         signal = SIGILL;
568                         break;
569                 }
570         } else
571                 signal = SIGILL;
572
573         if (signal == SIGFPE)
574                 do_fp_trap(regs, location,
575                            current->thread.fp_regs.fpc, interruption_code);
576         else if (signal) {
577                 siginfo_t info;
578                 info.si_signo = signal;
579                 info.si_errno = 0;
580                 info.si_code = ILL_ILLOPN;
581                 info.si_addr = location;
582                 do_trap(interruption_code, signal, 
583                         "specification exception", regs, &info);
584         }
585 }
586 #else
587 DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
588               ILL_ILLOPN, get_check_address(regs));
589 #endif
590
591 static void data_exception(struct pt_regs * regs, long interruption_code)
592 {
593         __u16 __user *location;
594         int signal = 0;
595
596         location = get_check_address(regs);
597
598         /*
599          * We got all needed information from the lowcore and can
600          * now safely switch on interrupts.
601          */
602         if (regs->psw.mask & PSW_MASK_PSTATE)
603                 local_irq_enable();
604
605         if (MACHINE_HAS_IEEE)
606                 asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
607
608 #ifdef CONFIG_MATHEMU
609         else if (regs->psw.mask & PSW_MASK_PSTATE) {
610                 __u8 opcode[6];
611                 get_user(*((__u16 *) opcode), location);
612                 switch (opcode[0]) {
613                 case 0x28: /* LDR Rx,Ry   */
614                         signal = math_emu_ldr(opcode);
615                         break;
616                 case 0x38: /* LER Rx,Ry   */
617                         signal = math_emu_ler(opcode);
618                         break;
619                 case 0x60: /* STD R,D(X,B) */
620                         get_user(*((__u16 *) (opcode+2)), location+1);
621                         signal = math_emu_std(opcode, regs);
622                         break;
623                 case 0x68: /* LD R,D(X,B) */
624                         get_user(*((__u16 *) (opcode+2)), location+1);
625                         signal = math_emu_ld(opcode, regs);
626                         break;
627                 case 0x70: /* STE R,D(X,B) */
628                         get_user(*((__u16 *) (opcode+2)), location+1);
629                         signal = math_emu_ste(opcode, regs);
630                         break;
631                 case 0x78: /* LE R,D(X,B) */
632                         get_user(*((__u16 *) (opcode+2)), location+1);
633                         signal = math_emu_le(opcode, regs);
634                         break;
635                 case 0xb3:
636                         get_user(*((__u16 *) (opcode+2)), location+1);
637                         signal = math_emu_b3(opcode, regs);
638                         break;
639                 case 0xed:
640                         get_user(*((__u32 *) (opcode+2)),
641                                  (__u32 __user *)(location+1));
642                         signal = math_emu_ed(opcode, regs);
643                         break;
644                 case 0xb2:
645                         if (opcode[1] == 0x99) {
646                                 get_user(*((__u16 *) (opcode+2)), location+1);
647                                 signal = math_emu_srnm(opcode, regs);
648                         } else if (opcode[1] == 0x9c) {
649                                 get_user(*((__u16 *) (opcode+2)), location+1);
650                                 signal = math_emu_stfpc(opcode, regs);
651                         } else if (opcode[1] == 0x9d) {
652                                 get_user(*((__u16 *) (opcode+2)), location+1);
653                                 signal = math_emu_lfpc(opcode, regs);
654                         } else
655                                 signal = SIGILL;
656                         break;
657                 default:
658                         signal = SIGILL;
659                         break;
660                 }
661         }
662 #endif 
663         if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
664                 signal = SIGFPE;
665         else
666                 signal = SIGILL;
667         if (signal == SIGFPE)
668                 do_fp_trap(regs, location,
669                            current->thread.fp_regs.fpc, interruption_code);
670         else if (signal) {
671                 siginfo_t info;
672                 info.si_signo = signal;
673                 info.si_errno = 0;
674                 info.si_code = ILL_ILLOPN;
675                 info.si_addr = location;
676                 do_trap(interruption_code, signal, 
677                         "data exception", regs, &info);
678         }
679 }
680
681 static void space_switch_exception(struct pt_regs * regs, long int_code)
682 {
683         siginfo_t info;
684
685         /* Set user psw back to home space mode. */
686         if (regs->psw.mask & PSW_MASK_PSTATE)
687                 regs->psw.mask |= PSW_ASC_HOME;
688         /* Send SIGILL. */
689         info.si_signo = SIGILL;
690         info.si_errno = 0;
691         info.si_code = ILL_PRVOPC;
692         info.si_addr = get_check_address(regs);
693         do_trap(int_code, SIGILL, "space switch event", regs, &info);
694 }
695
696 asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
697 {
698         bust_spinlocks(1);
699         printk("Kernel stack overflow.\n");
700         show_regs(regs);
701         bust_spinlocks(0);
702         panic("Corrupt kernel stack, can't continue.");
703 }
704
705 /* init is done in lowcore.S and head.S */
706
707 void __init trap_init(void)
708 {
709         int i;
710
711         for (i = 0; i < 128; i++)
712           pgm_check_table[i] = &default_trap_handler;
713         pgm_check_table[1] = &illegal_op;
714         pgm_check_table[2] = &privileged_op;
715         pgm_check_table[3] = &execute_exception;
716         pgm_check_table[4] = &do_protection_exception;
717         pgm_check_table[5] = &addressing_exception;
718         pgm_check_table[6] = &specification_exception;
719         pgm_check_table[7] = &data_exception;
720         pgm_check_table[8] = &overflow_exception;
721         pgm_check_table[9] = &divide_exception;
722         pgm_check_table[0x0A] = &overflow_exception;
723         pgm_check_table[0x0B] = &divide_exception;
724         pgm_check_table[0x0C] = &hfp_overflow_exception;
725         pgm_check_table[0x0D] = &hfp_underflow_exception;
726         pgm_check_table[0x0E] = &hfp_significance_exception;
727         pgm_check_table[0x0F] = &hfp_divide_exception;
728         pgm_check_table[0x10] = &do_dat_exception;
729         pgm_check_table[0x11] = &do_dat_exception;
730         pgm_check_table[0x12] = &translation_exception;
731         pgm_check_table[0x13] = &special_op_exception;
732 #ifdef CONFIG_64BIT
733         pgm_check_table[0x38] = &do_dat_exception;
734         pgm_check_table[0x39] = &do_dat_exception;
735         pgm_check_table[0x3A] = &do_dat_exception;
736         pgm_check_table[0x3B] = &do_dat_exception;
737 #endif /* CONFIG_64BIT */
738         pgm_check_table[0x15] = &operand_exception;
739         pgm_check_table[0x1C] = &space_switch_exception;
740         pgm_check_table[0x1D] = &hfp_sqrt_exception;
741         pgm_check_table[0x40] = &do_monitor_call;
742         pfault_irq_init();
743 }