xref: /openbmc/linux/arch/s390/kernel/traps.c (revision 54525552)
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/tracehook.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 int show_unhandled_signals;
50 
51 extern pgm_check_handler_t do_protection_exception;
52 extern pgm_check_handler_t do_dat_exception;
53 extern pgm_check_handler_t do_asce_exception;
54 
55 #define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
56 
57 #ifndef CONFIG_64BIT
58 #define LONG "%08lx "
59 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
60 static int kstack_depth_to_print = 12;
61 #else /* CONFIG_64BIT */
62 #define LONG "%016lx "
63 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
64 static int kstack_depth_to_print = 20;
65 #endif /* CONFIG_64BIT */
66 
67 /*
68  * For show_trace we have tree different stack to consider:
69  *   - the panic stack which is used if the kernel stack has overflown
70  *   - the asynchronous interrupt stack (cpu related)
71  *   - the synchronous kernel stack (process related)
72  * The stack trace can start at any of the three stack and can potentially
73  * touch all of them. The order is: panic stack, async stack, sync stack.
74  */
75 static unsigned long
76 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
77 {
78 	struct stack_frame *sf;
79 	struct pt_regs *regs;
80 
81 	while (1) {
82 		sp = sp & PSW_ADDR_INSN;
83 		if (sp < low || sp > high - sizeof(*sf))
84 			return sp;
85 		sf = (struct stack_frame *) sp;
86 		printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
87 		print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
88 		/* Follow the backchain. */
89 		while (1) {
90 			low = sp;
91 			sp = sf->back_chain & PSW_ADDR_INSN;
92 			if (!sp)
93 				break;
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 		}
100 		/* Zero backchain detected, check for interrupt frame. */
101 		sp = (unsigned long) (sf + 1);
102 		if (sp <= low || sp > high - sizeof(*regs))
103 			return sp;
104 		regs = (struct pt_regs *) sp;
105 		printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
106 		print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
107 		low = sp;
108 		sp = regs->gprs[15];
109 	}
110 }
111 
112 static void show_trace(struct task_struct *task, unsigned long *stack)
113 {
114 	register unsigned long __r15 asm ("15");
115 	unsigned long sp;
116 
117 	sp = (unsigned long) stack;
118 	if (!sp)
119 		sp = task ? task->thread.ksp : __r15;
120 	printk("Call Trace:\n");
121 #ifdef CONFIG_CHECK_STACK
122 	sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
123 			  S390_lowcore.panic_stack);
124 #endif
125 	sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
126 			  S390_lowcore.async_stack);
127 	if (task)
128 		__show_trace(sp, (unsigned long) task_stack_page(task),
129 			     (unsigned long) task_stack_page(task) + THREAD_SIZE);
130 	else
131 		__show_trace(sp, S390_lowcore.thread_info,
132 			     S390_lowcore.thread_info + THREAD_SIZE);
133 	if (!task)
134 		task = current;
135 	debug_show_held_locks(task);
136 }
137 
138 void show_stack(struct task_struct *task, unsigned long *sp)
139 {
140 	register unsigned long * __r15 asm ("15");
141 	unsigned long *stack;
142 	int i;
143 
144 	if (!sp)
145 		stack = task ? (unsigned long *) task->thread.ksp : __r15;
146 	else
147 		stack = sp;
148 
149 	for (i = 0; i < kstack_depth_to_print; i++) {
150 		if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
151 			break;
152 		if (i && ((i * sizeof (long) % 32) == 0))
153 			printk("\n       ");
154 		printk(LONG, *stack++);
155 	}
156 	printk("\n");
157 	show_trace(task, sp);
158 }
159 
160 static void show_last_breaking_event(struct pt_regs *regs)
161 {
162 #ifdef CONFIG_64BIT
163 	printk("Last Breaking-Event-Address:\n");
164 	printk(" [<%016lx>] ", regs->args[0] & PSW_ADDR_INSN);
165 	print_symbol("%s\n", regs->args[0] & PSW_ADDR_INSN);
166 #endif
167 }
168 
169 /*
170  * The architecture-independent dump_stack generator
171  */
172 void dump_stack(void)
173 {
174 	printk("CPU: %d %s %s %.*s\n",
175 	       task_thread_info(current)->cpu, print_tainted(),
176 	       init_utsname()->release,
177 	       (int)strcspn(init_utsname()->version, " "),
178 	       init_utsname()->version);
179 	printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
180 	       current->comm, current->pid, current,
181 	       (void *) current->thread.ksp);
182 	show_stack(NULL, NULL);
183 }
184 EXPORT_SYMBOL(dump_stack);
185 
186 static inline int mask_bits(struct pt_regs *regs, unsigned long bits)
187 {
188 	return (regs->psw.mask & bits) / ((~bits + 1) & bits);
189 }
190 
191 void show_registers(struct pt_regs *regs)
192 {
193 	char *mode;
194 
195 	mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
196 	printk("%s PSW : %p %p",
197 	       mode, (void *) regs->psw.mask,
198 	       (void *) regs->psw.addr);
199 	print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
200 	printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
201 	       "P:%x AS:%x CC:%x PM:%x", mask_bits(regs, PSW_MASK_PER),
202 	       mask_bits(regs, PSW_MASK_DAT), mask_bits(regs, PSW_MASK_IO),
203 	       mask_bits(regs, PSW_MASK_EXT), mask_bits(regs, PSW_MASK_KEY),
204 	       mask_bits(regs, PSW_MASK_MCHECK), mask_bits(regs, PSW_MASK_WAIT),
205 	       mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC),
206 	       mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM));
207 #ifdef CONFIG_64BIT
208 	printk(" EA:%x", mask_bits(regs, PSW_BASE_BITS));
209 #endif
210 	printk("\n%s GPRS: " FOURLONG, mode,
211 	       regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
212 	printk("           " FOURLONG,
213 	       regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
214 	printk("           " FOURLONG,
215 	       regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
216 	printk("           " FOURLONG,
217 	       regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
218 
219 	show_code(regs);
220 }
221 
222 void show_regs(struct pt_regs *regs)
223 {
224 	print_modules();
225 	printk("CPU: %d %s %s %.*s\n",
226 	       task_thread_info(current)->cpu, print_tainted(),
227 	       init_utsname()->release,
228 	       (int)strcspn(init_utsname()->version, " "),
229 	       init_utsname()->version);
230 	printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
231 	       current->comm, current->pid, current,
232 	       (void *) current->thread.ksp);
233 	show_registers(regs);
234 	/* Show stack backtrace if pt_regs is from kernel mode */
235 	if (!(regs->psw.mask & PSW_MASK_PSTATE))
236 		show_trace(NULL, (unsigned long *) regs->gprs[15]);
237 	show_last_breaking_event(regs);
238 }
239 
240 static DEFINE_SPINLOCK(die_lock);
241 
242 void die(const char * str, struct pt_regs * regs, long err)
243 {
244 	static int die_counter;
245 
246 	oops_enter();
247 	debug_stop_all();
248 	console_verbose();
249 	spin_lock_irq(&die_lock);
250 	bust_spinlocks(1);
251 	printk("%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
252 #ifdef CONFIG_PREEMPT
253 	printk("PREEMPT ");
254 #endif
255 #ifdef CONFIG_SMP
256 	printk("SMP ");
257 #endif
258 #ifdef CONFIG_DEBUG_PAGEALLOC
259 	printk("DEBUG_PAGEALLOC");
260 #endif
261 	printk("\n");
262 	notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
263 	show_regs(regs);
264 	bust_spinlocks(0);
265 	add_taint(TAINT_DIE);
266 	spin_unlock_irq(&die_lock);
267 	if (in_interrupt())
268 		panic("Fatal exception in interrupt");
269 	if (panic_on_oops)
270 		panic("Fatal exception: panic_on_oops");
271 	oops_exit();
272 	do_exit(SIGSEGV);
273 }
274 
275 static void inline report_user_fault(struct pt_regs *regs, long int_code,
276 				     int signr)
277 {
278 	if ((task_pid_nr(current) > 1) && !show_unhandled_signals)
279 		return;
280 	if (!unhandled_signal(current, signr))
281 		return;
282 	if (!printk_ratelimit())
283 		return;
284 	printk("User process fault: interruption code 0x%lX ", int_code);
285 	print_vma_addr("in ", regs->psw.addr & PSW_ADDR_INSN);
286 	printk("\n");
287 	show_regs(regs);
288 }
289 
290 int is_valid_bugaddr(unsigned long addr)
291 {
292 	return 1;
293 }
294 
295 static inline void __kprobes do_trap(long pgm_int_code, int signr, char *str,
296 				     struct pt_regs *regs, siginfo_t *info)
297 {
298 	if (notify_die(DIE_TRAP, str, regs, pgm_int_code,
299 		       pgm_int_code, signr) == NOTIFY_STOP)
300 		return;
301 
302         if (regs->psw.mask & PSW_MASK_PSTATE) {
303                 struct task_struct *tsk = current;
304 
305 		tsk->thread.trap_no = pgm_int_code & 0xffff;
306 		force_sig_info(signr, info, tsk);
307 		report_user_fault(regs, pgm_int_code, signr);
308         } else {
309                 const struct exception_table_entry *fixup;
310                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
311                 if (fixup)
312                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
313 		else {
314 			enum bug_trap_type btt;
315 
316 			btt = report_bug(regs->psw.addr & PSW_ADDR_INSN, regs);
317 			if (btt == BUG_TRAP_TYPE_WARN)
318 				return;
319 			die(str, regs, pgm_int_code);
320 		}
321         }
322 }
323 
324 static inline void __user *get_psw_address(struct pt_regs *regs,
325 					   long pgm_int_code)
326 {
327 	return (void __user *)
328 		((regs->psw.addr - (pgm_int_code >> 16)) & PSW_ADDR_INSN);
329 }
330 
331 void __kprobes do_per_trap(struct pt_regs *regs)
332 {
333 	if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0, SIGTRAP) == NOTIFY_STOP)
334 		return;
335 	if (tracehook_consider_fatal_signal(current, SIGTRAP))
336 		force_sig(SIGTRAP, current);
337 }
338 
339 static void default_trap_handler(struct pt_regs *regs, long pgm_int_code,
340 				 unsigned long trans_exc_code)
341 {
342         if (regs->psw.mask & PSW_MASK_PSTATE) {
343 		report_user_fault(regs, pgm_int_code, SIGSEGV);
344 		do_exit(SIGSEGV);
345 	} else
346 		die("Unknown program exception", regs, pgm_int_code);
347 }
348 
349 #define DO_ERROR_INFO(name, signr, sicode, str) \
350 static void name(struct pt_regs *regs, long pgm_int_code, \
351 		 unsigned long trans_exc_code) \
352 { \
353         siginfo_t info; \
354         info.si_signo = signr; \
355         info.si_errno = 0; \
356         info.si_code = sicode; \
357 	info.si_addr = get_psw_address(regs, pgm_int_code); \
358 	do_trap(pgm_int_code, signr, str, regs, &info);	    \
359 }
360 
361 DO_ERROR_INFO(addressing_exception, SIGILL, ILL_ILLADR,
362 	      "addressing exception")
363 DO_ERROR_INFO(execute_exception, SIGILL, ILL_ILLOPN,
364 	      "execute exception")
365 DO_ERROR_INFO(divide_exception, SIGFPE, FPE_INTDIV,
366 	      "fixpoint divide exception")
367 DO_ERROR_INFO(overflow_exception, SIGFPE, FPE_INTOVF,
368 	      "fixpoint overflow exception")
369 DO_ERROR_INFO(hfp_overflow_exception, SIGFPE, FPE_FLTOVF,
370 	      "HFP overflow exception")
371 DO_ERROR_INFO(hfp_underflow_exception, SIGFPE, FPE_FLTUND,
372 	      "HFP underflow exception")
373 DO_ERROR_INFO(hfp_significance_exception, SIGFPE, FPE_FLTRES,
374 	      "HFP significance exception")
375 DO_ERROR_INFO(hfp_divide_exception, SIGFPE, FPE_FLTDIV,
376 	      "HFP divide exception")
377 DO_ERROR_INFO(hfp_sqrt_exception, SIGFPE, FPE_FLTINV,
378 	      "HFP square root exception")
379 DO_ERROR_INFO(operand_exception, SIGILL, ILL_ILLOPN,
380 	      "operand exception")
381 DO_ERROR_INFO(privileged_op, SIGILL, ILL_PRVOPC,
382 	      "privileged operation")
383 DO_ERROR_INFO(special_op_exception, SIGILL, ILL_ILLOPN,
384 	      "special operation exception")
385 DO_ERROR_INFO(translation_exception, SIGILL, ILL_ILLOPN,
386 	      "translation exception")
387 
388 static inline void do_fp_trap(struct pt_regs *regs, void __user *location,
389 			      int fpc, long pgm_int_code)
390 {
391 	siginfo_t si;
392 
393 	si.si_signo = SIGFPE;
394 	si.si_errno = 0;
395 	si.si_addr = location;
396 	si.si_code = 0;
397 	/* FPC[2] is Data Exception Code */
398 	if ((fpc & 0x00000300) == 0) {
399 		/* bits 6 and 7 of DXC are 0 iff IEEE exception */
400 		if (fpc & 0x8000) /* invalid fp operation */
401 			si.si_code = FPE_FLTINV;
402 		else if (fpc & 0x4000) /* div by 0 */
403 			si.si_code = FPE_FLTDIV;
404 		else if (fpc & 0x2000) /* overflow */
405 			si.si_code = FPE_FLTOVF;
406 		else if (fpc & 0x1000) /* underflow */
407 			si.si_code = FPE_FLTUND;
408 		else if (fpc & 0x0800) /* inexact */
409 			si.si_code = FPE_FLTRES;
410 	}
411 	do_trap(pgm_int_code, SIGFPE,
412 		"floating point exception", regs, &si);
413 }
414 
415 static void __kprobes illegal_op(struct pt_regs *regs, long pgm_int_code,
416 				 unsigned long trans_exc_code)
417 {
418 	siginfo_t info;
419         __u8 opcode[6];
420 	__u16 __user *location;
421 	int signal = 0;
422 
423 	location = get_psw_address(regs, pgm_int_code);
424 
425 	if (regs->psw.mask & PSW_MASK_PSTATE) {
426 		if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
427 			return;
428 		if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
429 			if (tracehook_consider_fatal_signal(current, SIGTRAP))
430 				force_sig(SIGTRAP, current);
431 			else
432 				signal = SIGILL;
433 #ifdef CONFIG_MATHEMU
434 		} else if (opcode[0] == 0xb3) {
435 			if (get_user(*((__u16 *) (opcode+2)), location+1))
436 				return;
437 			signal = math_emu_b3(opcode, regs);
438                 } else if (opcode[0] == 0xed) {
439 			if (get_user(*((__u32 *) (opcode+2)),
440 				     (__u32 __user *)(location+1)))
441 				return;
442 			signal = math_emu_ed(opcode, regs);
443 		} else if (*((__u16 *) opcode) == 0xb299) {
444 			if (get_user(*((__u16 *) (opcode+2)), location+1))
445 				return;
446 			signal = math_emu_srnm(opcode, regs);
447 		} else if (*((__u16 *) opcode) == 0xb29c) {
448 			if (get_user(*((__u16 *) (opcode+2)), location+1))
449 				return;
450 			signal = math_emu_stfpc(opcode, regs);
451 		} else if (*((__u16 *) opcode) == 0xb29d) {
452 			if (get_user(*((__u16 *) (opcode+2)), location+1))
453 				return;
454 			signal = math_emu_lfpc(opcode, regs);
455 #endif
456 		} else
457 			signal = SIGILL;
458 	} else {
459 		/*
460 		 * If we get an illegal op in kernel mode, send it through the
461 		 * kprobes notifier. If kprobes doesn't pick it up, SIGILL
462 		 */
463 		if (notify_die(DIE_BPT, "bpt", regs, pgm_int_code,
464 			       3, SIGTRAP) != NOTIFY_STOP)
465 			signal = SIGILL;
466 	}
467 
468 #ifdef CONFIG_MATHEMU
469         if (signal == SIGFPE)
470 		do_fp_trap(regs, location,
471 			   current->thread.fp_regs.fpc, pgm_int_code);
472         else if (signal == SIGSEGV) {
473 		info.si_signo = signal;
474 		info.si_errno = 0;
475 		info.si_code = SEGV_MAPERR;
476 		info.si_addr = (void __user *) location;
477 		do_trap(pgm_int_code, signal,
478 			"user address fault", regs, &info);
479 	} else
480 #endif
481         if (signal) {
482 		info.si_signo = signal;
483 		info.si_errno = 0;
484 		info.si_code = ILL_ILLOPC;
485 		info.si_addr = (void __user *) location;
486 		do_trap(pgm_int_code, signal,
487 			"illegal operation", regs, &info);
488 	}
489 }
490 
491 
492 #ifdef CONFIG_MATHEMU
493 asmlinkage void specification_exception(struct pt_regs *regs,
494 					long pgm_int_code,
495 					unsigned long trans_exc_code)
496 {
497         __u8 opcode[6];
498 	__u16 __user *location = NULL;
499 	int signal = 0;
500 
501 	location = (__u16 __user *) get_psw_address(regs, pgm_int_code);
502 
503         if (regs->psw.mask & PSW_MASK_PSTATE) {
504 		get_user(*((__u16 *) opcode), location);
505 		switch (opcode[0]) {
506 		case 0x28: /* LDR Rx,Ry   */
507 			signal = math_emu_ldr(opcode);
508 			break;
509 		case 0x38: /* LER Rx,Ry   */
510 			signal = math_emu_ler(opcode);
511 			break;
512 		case 0x60: /* STD R,D(X,B) */
513 			get_user(*((__u16 *) (opcode+2)), location+1);
514 			signal = math_emu_std(opcode, regs);
515 			break;
516 		case 0x68: /* LD R,D(X,B) */
517 			get_user(*((__u16 *) (opcode+2)), location+1);
518 			signal = math_emu_ld(opcode, regs);
519 			break;
520 		case 0x70: /* STE R,D(X,B) */
521 			get_user(*((__u16 *) (opcode+2)), location+1);
522 			signal = math_emu_ste(opcode, regs);
523 			break;
524 		case 0x78: /* LE R,D(X,B) */
525 			get_user(*((__u16 *) (opcode+2)), location+1);
526 			signal = math_emu_le(opcode, regs);
527 			break;
528 		default:
529 			signal = SIGILL;
530 			break;
531                 }
532         } else
533 		signal = SIGILL;
534 
535         if (signal == SIGFPE)
536 		do_fp_trap(regs, location,
537 			   current->thread.fp_regs.fpc, pgm_int_code);
538         else if (signal) {
539 		siginfo_t info;
540 		info.si_signo = signal;
541 		info.si_errno = 0;
542 		info.si_code = ILL_ILLOPN;
543 		info.si_addr = location;
544 		do_trap(pgm_int_code, signal,
545 			"specification exception", regs, &info);
546 	}
547 }
548 #else
549 DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
550 	      "specification exception");
551 #endif
552 
553 static void data_exception(struct pt_regs *regs, long pgm_int_code,
554 			   unsigned long trans_exc_code)
555 {
556 	__u16 __user *location;
557 	int signal = 0;
558 
559 	location = get_psw_address(regs, pgm_int_code);
560 
561 	if (MACHINE_HAS_IEEE)
562 		asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
563 
564 #ifdef CONFIG_MATHEMU
565         else if (regs->psw.mask & PSW_MASK_PSTATE) {
566         	__u8 opcode[6];
567 		get_user(*((__u16 *) opcode), location);
568 		switch (opcode[0]) {
569 		case 0x28: /* LDR Rx,Ry   */
570 			signal = math_emu_ldr(opcode);
571 			break;
572 		case 0x38: /* LER Rx,Ry   */
573 			signal = math_emu_ler(opcode);
574 			break;
575 		case 0x60: /* STD R,D(X,B) */
576 			get_user(*((__u16 *) (opcode+2)), location+1);
577 			signal = math_emu_std(opcode, regs);
578 			break;
579 		case 0x68: /* LD R,D(X,B) */
580 			get_user(*((__u16 *) (opcode+2)), location+1);
581 			signal = math_emu_ld(opcode, regs);
582 			break;
583 		case 0x70: /* STE R,D(X,B) */
584 			get_user(*((__u16 *) (opcode+2)), location+1);
585 			signal = math_emu_ste(opcode, regs);
586 			break;
587 		case 0x78: /* LE R,D(X,B) */
588 			get_user(*((__u16 *) (opcode+2)), location+1);
589 			signal = math_emu_le(opcode, regs);
590 			break;
591 		case 0xb3:
592 			get_user(*((__u16 *) (opcode+2)), location+1);
593 			signal = math_emu_b3(opcode, regs);
594 			break;
595                 case 0xed:
596 			get_user(*((__u32 *) (opcode+2)),
597 				 (__u32 __user *)(location+1));
598 			signal = math_emu_ed(opcode, regs);
599 			break;
600 	        case 0xb2:
601 			if (opcode[1] == 0x99) {
602 				get_user(*((__u16 *) (opcode+2)), location+1);
603 				signal = math_emu_srnm(opcode, regs);
604 			} else if (opcode[1] == 0x9c) {
605 				get_user(*((__u16 *) (opcode+2)), location+1);
606 				signal = math_emu_stfpc(opcode, regs);
607 			} else if (opcode[1] == 0x9d) {
608 				get_user(*((__u16 *) (opcode+2)), location+1);
609 				signal = math_emu_lfpc(opcode, regs);
610 			} else
611 				signal = SIGILL;
612 			break;
613 		default:
614 			signal = SIGILL;
615 			break;
616                 }
617         }
618 #endif
619 	if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
620 		signal = SIGFPE;
621 	else
622 		signal = SIGILL;
623         if (signal == SIGFPE)
624 		do_fp_trap(regs, location,
625 			   current->thread.fp_regs.fpc, pgm_int_code);
626         else if (signal) {
627 		siginfo_t info;
628 		info.si_signo = signal;
629 		info.si_errno = 0;
630 		info.si_code = ILL_ILLOPN;
631 		info.si_addr = location;
632 		do_trap(pgm_int_code, signal, "data exception", regs, &info);
633 	}
634 }
635 
636 static void space_switch_exception(struct pt_regs *regs, long pgm_int_code,
637 				   unsigned long trans_exc_code)
638 {
639         siginfo_t info;
640 
641 	/* Set user psw back to home space mode. */
642 	if (regs->psw.mask & PSW_MASK_PSTATE)
643 		regs->psw.mask |= PSW_ASC_HOME;
644 	/* Send SIGILL. */
645         info.si_signo = SIGILL;
646         info.si_errno = 0;
647         info.si_code = ILL_PRVOPC;
648 	info.si_addr = get_psw_address(regs, pgm_int_code);
649 	do_trap(pgm_int_code, SIGILL, "space switch event", regs, &info);
650 }
651 
652 asmlinkage void __kprobes kernel_stack_overflow(struct pt_regs * regs)
653 {
654 	bust_spinlocks(1);
655 	printk("Kernel stack overflow.\n");
656 	show_regs(regs);
657 	bust_spinlocks(0);
658 	panic("Corrupt kernel stack, can't continue.");
659 }
660 
661 /* init is done in lowcore.S and head.S */
662 
663 void __init trap_init(void)
664 {
665         int i;
666 
667         for (i = 0; i < 128; i++)
668           pgm_check_table[i] = &default_trap_handler;
669         pgm_check_table[1] = &illegal_op;
670         pgm_check_table[2] = &privileged_op;
671         pgm_check_table[3] = &execute_exception;
672         pgm_check_table[4] = &do_protection_exception;
673         pgm_check_table[5] = &addressing_exception;
674         pgm_check_table[6] = &specification_exception;
675         pgm_check_table[7] = &data_exception;
676         pgm_check_table[8] = &overflow_exception;
677         pgm_check_table[9] = &divide_exception;
678         pgm_check_table[0x0A] = &overflow_exception;
679         pgm_check_table[0x0B] = &divide_exception;
680         pgm_check_table[0x0C] = &hfp_overflow_exception;
681         pgm_check_table[0x0D] = &hfp_underflow_exception;
682         pgm_check_table[0x0E] = &hfp_significance_exception;
683         pgm_check_table[0x0F] = &hfp_divide_exception;
684         pgm_check_table[0x10] = &do_dat_exception;
685         pgm_check_table[0x11] = &do_dat_exception;
686         pgm_check_table[0x12] = &translation_exception;
687         pgm_check_table[0x13] = &special_op_exception;
688 #ifdef CONFIG_64BIT
689 	pgm_check_table[0x38] = &do_asce_exception;
690 	pgm_check_table[0x39] = &do_dat_exception;
691 	pgm_check_table[0x3A] = &do_dat_exception;
692         pgm_check_table[0x3B] = &do_dat_exception;
693 #endif /* CONFIG_64BIT */
694         pgm_check_table[0x15] = &operand_exception;
695         pgm_check_table[0x1C] = &space_switch_exception;
696         pgm_check_table[0x1D] = &hfp_sqrt_exception;
697 	/* Enable machine checks early. */
698 	local_mcck_enable();
699 }
700