[S390] kernel: show last breaking-event-address on oops
[safe/jmp/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/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 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 #ifdef CONFIG_64BIT
165 void show_last_breaking_event(struct pt_regs *regs)
166 {
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 }
171 #endif
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 /* This is called from fs/proc/array.c */
227 void task_show_regs(struct seq_file *m, struct task_struct *task)
228 {
229         struct pt_regs *regs;
230
231         regs = task_pt_regs(task);
232         seq_printf(m, "task: %p, ksp: %p\n",
233                        task, (void *)task->thread.ksp);
234         seq_printf(m, "User PSW : %p %p\n",
235                        (void *) regs->psw.mask, (void *)regs->psw.addr);
236
237         seq_printf(m, "User GPRS: " FOURLONG,
238                           regs->gprs[0], regs->gprs[1],
239                           regs->gprs[2], regs->gprs[3]);
240         seq_printf(m, "           " FOURLONG,
241                           regs->gprs[4], regs->gprs[5],
242                           regs->gprs[6], regs->gprs[7]);
243         seq_printf(m, "           " FOURLONG,
244                           regs->gprs[8], regs->gprs[9],
245                           regs->gprs[10], regs->gprs[11]);
246         seq_printf(m, "           " FOURLONG,
247                           regs->gprs[12], regs->gprs[13],
248                           regs->gprs[14], regs->gprs[15]);
249         seq_printf(m, "User ACRS: %08x %08x %08x %08x\n",
250                           task->thread.acrs[0], task->thread.acrs[1],
251                           task->thread.acrs[2], task->thread.acrs[3]);
252         seq_printf(m, "           %08x %08x %08x %08x\n",
253                           task->thread.acrs[4], task->thread.acrs[5],
254                           task->thread.acrs[6], task->thread.acrs[7]);
255         seq_printf(m, "           %08x %08x %08x %08x\n",
256                           task->thread.acrs[8], task->thread.acrs[9],
257                           task->thread.acrs[10], task->thread.acrs[11]);
258         seq_printf(m, "           %08x %08x %08x %08x\n",
259                           task->thread.acrs[12], task->thread.acrs[13],
260                           task->thread.acrs[14], task->thread.acrs[15]);
261 }
262
263 static DEFINE_SPINLOCK(die_lock);
264
265 void die(const char * str, struct pt_regs * regs, long err)
266 {
267         static int die_counter;
268
269         oops_enter();
270         debug_stop_all();
271         console_verbose();
272         spin_lock_irq(&die_lock);
273         bust_spinlocks(1);
274         printk("%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
275 #ifdef CONFIG_PREEMPT
276         printk("PREEMPT ");
277 #endif
278 #ifdef CONFIG_SMP
279         printk("SMP ");
280 #endif
281 #ifdef CONFIG_DEBUG_PAGEALLOC
282         printk("DEBUG_PAGEALLOC");
283 #endif
284         printk("\n");
285         notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
286         show_regs(regs);
287         bust_spinlocks(0);
288         add_taint(TAINT_DIE);
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         oops_exit();
295         do_exit(SIGSEGV);
296 }
297
298 static void inline
299 report_user_fault(long interruption_code, struct pt_regs *regs)
300 {
301 #if defined(CONFIG_SYSCTL)
302         if (!sysctl_userprocess_debug)
303                 return;
304 #endif
305 #if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG)
306         printk("User process fault: interruption code 0x%lX\n",
307                interruption_code);
308         show_regs(regs);
309 #endif
310 }
311
312 int is_valid_bugaddr(unsigned long addr)
313 {
314         return 1;
315 }
316
317 static void __kprobes inline do_trap(long interruption_code, int signr,
318                                         char *str, struct pt_regs *regs,
319                                         siginfo_t *info)
320 {
321         /*
322          * We got all needed information from the lowcore and can
323          * now safely switch on interrupts.
324          */
325         if (regs->psw.mask & PSW_MASK_PSTATE)
326                 local_irq_enable();
327
328         if (notify_die(DIE_TRAP, str, regs, interruption_code,
329                                 interruption_code, signr) == NOTIFY_STOP)
330                 return;
331
332         if (regs->psw.mask & PSW_MASK_PSTATE) {
333                 struct task_struct *tsk = current;
334
335                 tsk->thread.trap_no = interruption_code & 0xffff;
336                 force_sig_info(signr, info, tsk);
337                 report_user_fault(interruption_code, regs);
338         } else {
339                 const struct exception_table_entry *fixup;
340                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
341                 if (fixup)
342                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
343                 else {
344                         enum bug_trap_type btt;
345
346                         btt = report_bug(regs->psw.addr & PSW_ADDR_INSN, regs);
347                         if (btt == BUG_TRAP_TYPE_WARN)
348                                 return;
349                         die(str, regs, interruption_code);
350                 }
351         }
352 }
353
354 static inline void __user *get_check_address(struct pt_regs *regs)
355 {
356         return (void __user *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
357 }
358
359 void __kprobes do_single_step(struct pt_regs *regs)
360 {
361         if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0,
362                                         SIGTRAP) == NOTIFY_STOP){
363                 return;
364         }
365         if ((current->ptrace & PT_PTRACED) != 0)
366                 force_sig(SIGTRAP, current);
367 }
368
369 static void default_trap_handler(struct pt_regs * regs, long interruption_code)
370 {
371         if (regs->psw.mask & PSW_MASK_PSTATE) {
372                 local_irq_enable();
373                 do_exit(SIGSEGV);
374                 report_user_fault(interruption_code, regs);
375         } else
376                 die("Unknown program exception", regs, interruption_code);
377 }
378
379 #define DO_ERROR_INFO(signr, str, name, sicode, siaddr) \
380 static void name(struct pt_regs * regs, long interruption_code) \
381 { \
382         siginfo_t info; \
383         info.si_signo = signr; \
384         info.si_errno = 0; \
385         info.si_code = sicode; \
386         info.si_addr = siaddr; \
387         do_trap(interruption_code, signr, str, regs, &info); \
388 }
389
390 DO_ERROR_INFO(SIGILL, "addressing exception", addressing_exception,
391               ILL_ILLADR, get_check_address(regs))
392 DO_ERROR_INFO(SIGILL,  "execute exception", execute_exception,
393               ILL_ILLOPN, get_check_address(regs))
394 DO_ERROR_INFO(SIGFPE,  "fixpoint divide exception", divide_exception,
395               FPE_INTDIV, get_check_address(regs))
396 DO_ERROR_INFO(SIGFPE,  "fixpoint overflow exception", overflow_exception,
397               FPE_INTOVF, get_check_address(regs))
398 DO_ERROR_INFO(SIGFPE,  "HFP overflow exception", hfp_overflow_exception,
399               FPE_FLTOVF, get_check_address(regs))
400 DO_ERROR_INFO(SIGFPE,  "HFP underflow exception", hfp_underflow_exception,
401               FPE_FLTUND, get_check_address(regs))
402 DO_ERROR_INFO(SIGFPE,  "HFP significance exception", hfp_significance_exception,
403               FPE_FLTRES, get_check_address(regs))
404 DO_ERROR_INFO(SIGFPE,  "HFP divide exception", hfp_divide_exception,
405               FPE_FLTDIV, get_check_address(regs))
406 DO_ERROR_INFO(SIGFPE,  "HFP square root exception", hfp_sqrt_exception,
407               FPE_FLTINV, get_check_address(regs))
408 DO_ERROR_INFO(SIGILL,  "operand exception", operand_exception,
409               ILL_ILLOPN, get_check_address(regs))
410 DO_ERROR_INFO(SIGILL,  "privileged operation", privileged_op,
411               ILL_PRVOPC, get_check_address(regs))
412 DO_ERROR_INFO(SIGILL,  "special operation exception", special_op_exception,
413               ILL_ILLOPN, get_check_address(regs))
414 DO_ERROR_INFO(SIGILL,  "translation exception", translation_exception,
415               ILL_ILLOPN, get_check_address(regs))
416
417 static inline void
418 do_fp_trap(struct pt_regs *regs, void __user *location,
419            int fpc, long interruption_code)
420 {
421         siginfo_t si;
422
423         si.si_signo = SIGFPE;
424         si.si_errno = 0;
425         si.si_addr = location;
426         si.si_code = 0;
427         /* FPC[2] is Data Exception Code */
428         if ((fpc & 0x00000300) == 0) {
429                 /* bits 6 and 7 of DXC are 0 iff IEEE exception */
430                 if (fpc & 0x8000) /* invalid fp operation */
431                         si.si_code = FPE_FLTINV;
432                 else if (fpc & 0x4000) /* div by 0 */
433                         si.si_code = FPE_FLTDIV;
434                 else if (fpc & 0x2000) /* overflow */
435                         si.si_code = FPE_FLTOVF;
436                 else if (fpc & 0x1000) /* underflow */
437                         si.si_code = FPE_FLTUND;
438                 else if (fpc & 0x0800) /* inexact */
439                         si.si_code = FPE_FLTRES;
440         }
441         current->thread.ieee_instruction_pointer = (addr_t) location;
442         do_trap(interruption_code, SIGFPE,
443                 "floating point exception", regs, &si);
444 }
445
446 static void illegal_op(struct pt_regs * regs, long interruption_code)
447 {
448         siginfo_t info;
449         __u8 opcode[6];
450         __u16 __user *location;
451         int signal = 0;
452
453         location = get_check_address(regs);
454
455         /*
456          * We got all needed information from the lowcore and can
457          * now safely switch on interrupts.
458          */
459         if (regs->psw.mask & PSW_MASK_PSTATE)
460                 local_irq_enable();
461
462         if (regs->psw.mask & PSW_MASK_PSTATE) {
463                 if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
464                         return;
465                 if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
466                         if (current->ptrace & PT_PTRACED)
467                                 force_sig(SIGTRAP, current);
468                         else
469                                 signal = SIGILL;
470 #ifdef CONFIG_MATHEMU
471                 } else if (opcode[0] == 0xb3) {
472                         if (get_user(*((__u16 *) (opcode+2)), location+1))
473                                 return;
474                         signal = math_emu_b3(opcode, regs);
475                 } else if (opcode[0] == 0xed) {
476                         if (get_user(*((__u32 *) (opcode+2)),
477                                      (__u32 __user *)(location+1)))
478                                 return;
479                         signal = math_emu_ed(opcode, regs);
480                 } else if (*((__u16 *) opcode) == 0xb299) {
481                         if (get_user(*((__u16 *) (opcode+2)), location+1))
482                                 return;
483                         signal = math_emu_srnm(opcode, regs);
484                 } else if (*((__u16 *) opcode) == 0xb29c) {
485                         if (get_user(*((__u16 *) (opcode+2)), location+1))
486                                 return;
487                         signal = math_emu_stfpc(opcode, regs);
488                 } else if (*((__u16 *) opcode) == 0xb29d) {
489                         if (get_user(*((__u16 *) (opcode+2)), location+1))
490                                 return;
491                         signal = math_emu_lfpc(opcode, regs);
492 #endif
493                 } else
494                         signal = SIGILL;
495         } else {
496                 /*
497                  * If we get an illegal op in kernel mode, send it through the
498                  * kprobes notifier. If kprobes doesn't pick it up, SIGILL
499                  */
500                 if (notify_die(DIE_BPT, "bpt", regs, interruption_code,
501                                3, SIGTRAP) != NOTIFY_STOP)
502                         signal = SIGILL;
503         }
504
505 #ifdef CONFIG_MATHEMU
506         if (signal == SIGFPE)
507                 do_fp_trap(regs, location,
508                            current->thread.fp_regs.fpc, interruption_code);
509         else if (signal == SIGSEGV) {
510                 info.si_signo = signal;
511                 info.si_errno = 0;
512                 info.si_code = SEGV_MAPERR;
513                 info.si_addr = (void __user *) location;
514                 do_trap(interruption_code, signal,
515                         "user address fault", regs, &info);
516         } else
517 #endif
518         if (signal) {
519                 info.si_signo = signal;
520                 info.si_errno = 0;
521                 info.si_code = ILL_ILLOPC;
522                 info.si_addr = (void __user *) location;
523                 do_trap(interruption_code, signal,
524                         "illegal operation", regs, &info);
525         }
526 }
527
528
529 #ifdef CONFIG_MATHEMU
530 asmlinkage void 
531 specification_exception(struct pt_regs * regs, long interruption_code)
532 {
533         __u8 opcode[6];
534         __u16 __user *location = NULL;
535         int signal = 0;
536
537         location = (__u16 __user *) get_check_address(regs);
538
539         /*
540          * We got all needed information from the lowcore and can
541          * now safely switch on interrupts.
542          */
543         if (regs->psw.mask & PSW_MASK_PSTATE)
544                 local_irq_enable();
545
546         if (regs->psw.mask & PSW_MASK_PSTATE) {
547                 get_user(*((__u16 *) opcode), location);
548                 switch (opcode[0]) {
549                 case 0x28: /* LDR Rx,Ry   */
550                         signal = math_emu_ldr(opcode);
551                         break;
552                 case 0x38: /* LER Rx,Ry   */
553                         signal = math_emu_ler(opcode);
554                         break;
555                 case 0x60: /* STD R,D(X,B) */
556                         get_user(*((__u16 *) (opcode+2)), location+1);
557                         signal = math_emu_std(opcode, regs);
558                         break;
559                 case 0x68: /* LD R,D(X,B) */
560                         get_user(*((__u16 *) (opcode+2)), location+1);
561                         signal = math_emu_ld(opcode, regs);
562                         break;
563                 case 0x70: /* STE R,D(X,B) */
564                         get_user(*((__u16 *) (opcode+2)), location+1);
565                         signal = math_emu_ste(opcode, regs);
566                         break;
567                 case 0x78: /* LE R,D(X,B) */
568                         get_user(*((__u16 *) (opcode+2)), location+1);
569                         signal = math_emu_le(opcode, regs);
570                         break;
571                 default:
572                         signal = SIGILL;
573                         break;
574                 }
575         } else
576                 signal = SIGILL;
577
578         if (signal == SIGFPE)
579                 do_fp_trap(regs, location,
580                            current->thread.fp_regs.fpc, interruption_code);
581         else if (signal) {
582                 siginfo_t info;
583                 info.si_signo = signal;
584                 info.si_errno = 0;
585                 info.si_code = ILL_ILLOPN;
586                 info.si_addr = location;
587                 do_trap(interruption_code, signal, 
588                         "specification exception", regs, &info);
589         }
590 }
591 #else
592 DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
593               ILL_ILLOPN, get_check_address(regs));
594 #endif
595
596 static void data_exception(struct pt_regs * regs, long interruption_code)
597 {
598         __u16 __user *location;
599         int signal = 0;
600
601         location = get_check_address(regs);
602
603         /*
604          * We got all needed information from the lowcore and can
605          * now safely switch on interrupts.
606          */
607         if (regs->psw.mask & PSW_MASK_PSTATE)
608                 local_irq_enable();
609
610         if (MACHINE_HAS_IEEE)
611                 asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
612
613 #ifdef CONFIG_MATHEMU
614         else if (regs->psw.mask & PSW_MASK_PSTATE) {
615                 __u8 opcode[6];
616                 get_user(*((__u16 *) opcode), location);
617                 switch (opcode[0]) {
618                 case 0x28: /* LDR Rx,Ry   */
619                         signal = math_emu_ldr(opcode);
620                         break;
621                 case 0x38: /* LER Rx,Ry   */
622                         signal = math_emu_ler(opcode);
623                         break;
624                 case 0x60: /* STD R,D(X,B) */
625                         get_user(*((__u16 *) (opcode+2)), location+1);
626                         signal = math_emu_std(opcode, regs);
627                         break;
628                 case 0x68: /* LD R,D(X,B) */
629                         get_user(*((__u16 *) (opcode+2)), location+1);
630                         signal = math_emu_ld(opcode, regs);
631                         break;
632                 case 0x70: /* STE R,D(X,B) */
633                         get_user(*((__u16 *) (opcode+2)), location+1);
634                         signal = math_emu_ste(opcode, regs);
635                         break;
636                 case 0x78: /* LE R,D(X,B) */
637                         get_user(*((__u16 *) (opcode+2)), location+1);
638                         signal = math_emu_le(opcode, regs);
639                         break;
640                 case 0xb3:
641                         get_user(*((__u16 *) (opcode+2)), location+1);
642                         signal = math_emu_b3(opcode, regs);
643                         break;
644                 case 0xed:
645                         get_user(*((__u32 *) (opcode+2)),
646                                  (__u32 __user *)(location+1));
647                         signal = math_emu_ed(opcode, regs);
648                         break;
649                 case 0xb2:
650                         if (opcode[1] == 0x99) {
651                                 get_user(*((__u16 *) (opcode+2)), location+1);
652                                 signal = math_emu_srnm(opcode, regs);
653                         } else if (opcode[1] == 0x9c) {
654                                 get_user(*((__u16 *) (opcode+2)), location+1);
655                                 signal = math_emu_stfpc(opcode, regs);
656                         } else if (opcode[1] == 0x9d) {
657                                 get_user(*((__u16 *) (opcode+2)), location+1);
658                                 signal = math_emu_lfpc(opcode, regs);
659                         } else
660                                 signal = SIGILL;
661                         break;
662                 default:
663                         signal = SIGILL;
664                         break;
665                 }
666         }
667 #endif 
668         if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
669                 signal = SIGFPE;
670         else
671                 signal = SIGILL;
672         if (signal == SIGFPE)
673                 do_fp_trap(regs, location,
674                            current->thread.fp_regs.fpc, interruption_code);
675         else if (signal) {
676                 siginfo_t info;
677                 info.si_signo = signal;
678                 info.si_errno = 0;
679                 info.si_code = ILL_ILLOPN;
680                 info.si_addr = location;
681                 do_trap(interruption_code, signal, 
682                         "data exception", regs, &info);
683         }
684 }
685
686 static void space_switch_exception(struct pt_regs * regs, long int_code)
687 {
688         siginfo_t info;
689
690         /* Set user psw back to home space mode. */
691         if (regs->psw.mask & PSW_MASK_PSTATE)
692                 regs->psw.mask |= PSW_ASC_HOME;
693         /* Send SIGILL. */
694         info.si_signo = SIGILL;
695         info.si_errno = 0;
696         info.si_code = ILL_PRVOPC;
697         info.si_addr = get_check_address(regs);
698         do_trap(int_code, SIGILL, "space switch event", regs, &info);
699 }
700
701 asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
702 {
703         bust_spinlocks(1);
704         printk("Kernel stack overflow.\n");
705         show_regs(regs);
706         bust_spinlocks(0);
707         panic("Corrupt kernel stack, can't continue.");
708 }
709
710 /* init is done in lowcore.S and head.S */
711
712 void __init trap_init(void)
713 {
714         int i;
715
716         for (i = 0; i < 128; i++)
717           pgm_check_table[i] = &default_trap_handler;
718         pgm_check_table[1] = &illegal_op;
719         pgm_check_table[2] = &privileged_op;
720         pgm_check_table[3] = &execute_exception;
721         pgm_check_table[4] = &do_protection_exception;
722         pgm_check_table[5] = &addressing_exception;
723         pgm_check_table[6] = &specification_exception;
724         pgm_check_table[7] = &data_exception;
725         pgm_check_table[8] = &overflow_exception;
726         pgm_check_table[9] = &divide_exception;
727         pgm_check_table[0x0A] = &overflow_exception;
728         pgm_check_table[0x0B] = &divide_exception;
729         pgm_check_table[0x0C] = &hfp_overflow_exception;
730         pgm_check_table[0x0D] = &hfp_underflow_exception;
731         pgm_check_table[0x0E] = &hfp_significance_exception;
732         pgm_check_table[0x0F] = &hfp_divide_exception;
733         pgm_check_table[0x10] = &do_dat_exception;
734         pgm_check_table[0x11] = &do_dat_exception;
735         pgm_check_table[0x12] = &translation_exception;
736         pgm_check_table[0x13] = &special_op_exception;
737 #ifdef CONFIG_64BIT
738         pgm_check_table[0x38] = &do_asce_exception;
739         pgm_check_table[0x39] = &do_dat_exception;
740         pgm_check_table[0x3A] = &do_dat_exception;
741         pgm_check_table[0x3B] = &do_dat_exception;
742 #endif /* CONFIG_64BIT */
743         pgm_check_table[0x15] = &operand_exception;
744         pgm_check_table[0x1C] = &space_switch_exception;
745         pgm_check_table[0x1D] = &hfp_sqrt_exception;
746         pfault_irq_init();
747 }