xref: /linux/arch/s390/kernel/traps.c (revision f8343685643f2901fe11aa9d0358cafbeaf7b4c3)
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 <asm/system.h>
35 #include <asm/uaccess.h>
36 #include <asm/io.h>
37 #include <asm/atomic.h>
38 #include <asm/mathemu.h>
39 #include <asm/cpcmd.h>
40 #include <asm/s390_ext.h>
41 #include <asm/lowcore.h>
42 #include <asm/debug.h>
43 
44 /* Called from entry.S only */
45 extern void handle_per_exception(struct pt_regs *regs);
46 
47 typedef void pgm_check_handler_t(struct pt_regs *, long);
48 pgm_check_handler_t *pgm_check_table[128];
49 
50 #ifdef CONFIG_SYSCTL
51 #ifdef CONFIG_PROCESS_DEBUG
52 int sysctl_userprocess_debug = 1;
53 #else
54 int sysctl_userprocess_debug = 0;
55 #endif
56 #endif
57 
58 extern pgm_check_handler_t do_protection_exception;
59 extern pgm_check_handler_t do_dat_exception;
60 extern pgm_check_handler_t do_monitor_call;
61 
62 #define stack_pointer ({ void **sp; asm("la %0,0(15)" : "=&d" (sp)); sp; })
63 
64 #ifndef CONFIG_64BIT
65 #define FOURLONG "%08lx %08lx %08lx %08lx\n"
66 static int kstack_depth_to_print = 12;
67 #else /* CONFIG_64BIT */
68 #define FOURLONG "%016lx %016lx %016lx %016lx\n"
69 static int kstack_depth_to_print = 20;
70 #endif /* CONFIG_64BIT */
71 
72 /*
73  * For show_trace we have tree different stack to consider:
74  *   - the panic stack which is used if the kernel stack has overflown
75  *   - the asynchronous interrupt stack (cpu related)
76  *   - the synchronous kernel stack (process related)
77  * The stack trace can start at any of the three stack and can potentially
78  * touch all of them. The order is: panic stack, async stack, sync stack.
79  */
80 static unsigned long
81 __show_trace(unsigned long sp, unsigned long low, unsigned long high)
82 {
83 	struct stack_frame *sf;
84 	struct pt_regs *regs;
85 
86 	while (1) {
87 		sp = sp & PSW_ADDR_INSN;
88 		if (sp < low || sp > high - sizeof(*sf))
89 			return sp;
90 		sf = (struct stack_frame *) sp;
91 		printk("([<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
92 		print_symbol("%s)\n", sf->gprs[8] & PSW_ADDR_INSN);
93 		/* Follow the backchain. */
94 		while (1) {
95 			low = sp;
96 			sp = sf->back_chain & PSW_ADDR_INSN;
97 			if (!sp)
98 				break;
99 			if (sp <= low || sp > high - sizeof(*sf))
100 				return sp;
101 			sf = (struct stack_frame *) sp;
102 			printk(" [<%016lx>] ", sf->gprs[8] & PSW_ADDR_INSN);
103 			print_symbol("%s\n", sf->gprs[8] & PSW_ADDR_INSN);
104 		}
105 		/* Zero backchain detected, check for interrupt frame. */
106 		sp = (unsigned long) (sf + 1);
107 		if (sp <= low || sp > high - sizeof(*regs))
108 			return sp;
109 		regs = (struct pt_regs *) sp;
110 		printk(" [<%016lx>] ", regs->psw.addr & PSW_ADDR_INSN);
111 		print_symbol("%s\n", regs->psw.addr & PSW_ADDR_INSN);
112 		low = sp;
113 		sp = regs->gprs[15];
114 	}
115 }
116 
117 void show_trace(struct task_struct *task, unsigned long *stack)
118 {
119 	register unsigned long __r15 asm ("15");
120 	unsigned long sp;
121 
122 	sp = (unsigned long) stack;
123 	if (!sp)
124 		sp = task ? task->thread.ksp : __r15;
125 	printk("Call Trace:\n");
126 #ifdef CONFIG_CHECK_STACK
127 	sp = __show_trace(sp, S390_lowcore.panic_stack - 4096,
128 			  S390_lowcore.panic_stack);
129 #endif
130 	sp = __show_trace(sp, S390_lowcore.async_stack - ASYNC_SIZE,
131 			  S390_lowcore.async_stack);
132 	if (task)
133 		__show_trace(sp, (unsigned long) task_stack_page(task),
134 			     (unsigned long) task_stack_page(task) + THREAD_SIZE);
135 	else
136 		__show_trace(sp, S390_lowcore.thread_info,
137 			     S390_lowcore.thread_info + THREAD_SIZE);
138 	printk("\n");
139 	if (!task)
140 		task = current;
141 	debug_show_held_locks(task);
142 }
143 
144 void show_stack(struct task_struct *task, unsigned long *sp)
145 {
146 	register unsigned long * __r15 asm ("15");
147 	unsigned long *stack;
148 	int i;
149 
150 	if (!sp)
151 		stack = task ? (unsigned long *) task->thread.ksp : __r15;
152 	else
153 		stack = sp;
154 
155 	for (i = 0; i < kstack_depth_to_print; i++) {
156 		if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
157 			break;
158 		if (i && ((i * sizeof (long) % 32) == 0))
159 			printk("\n       ");
160 		printk("%p ", (void *)*stack++);
161 	}
162 	printk("\n");
163 	show_trace(task, sp);
164 }
165 
166 /*
167  * The architecture-independent dump_stack generator
168  */
169 void dump_stack(void)
170 {
171 	show_stack(NULL, NULL);
172 }
173 
174 EXPORT_SYMBOL(dump_stack);
175 
176 static inline int mask_bits(struct pt_regs *regs, unsigned long bits)
177 {
178 	return (regs->psw.mask & bits) / ((~bits + 1) & bits);
179 }
180 
181 void show_registers(struct pt_regs *regs)
182 {
183 	char *mode;
184 
185 	mode = (regs->psw.mask & PSW_MASK_PSTATE) ? "User" : "Krnl";
186 	printk("%s PSW : %p %p",
187 	       mode, (void *) regs->psw.mask,
188 	       (void *) regs->psw.addr);
189 	print_symbol(" (%s)\n", regs->psw.addr & PSW_ADDR_INSN);
190 	printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
191 	       "P:%x AS:%x CC:%x PM:%x", mask_bits(regs, PSW_MASK_PER),
192 	       mask_bits(regs, PSW_MASK_DAT), mask_bits(regs, PSW_MASK_IO),
193 	       mask_bits(regs, PSW_MASK_EXT), mask_bits(regs, PSW_MASK_KEY),
194 	       mask_bits(regs, PSW_MASK_MCHECK), mask_bits(regs, PSW_MASK_WAIT),
195 	       mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC),
196 	       mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM));
197 #ifdef CONFIG_64BIT
198 	printk(" EA:%x", mask_bits(regs, PSW_BASE_BITS));
199 #endif
200 	printk("\n%s GPRS: " FOURLONG, mode,
201 	       regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
202 	printk("           " FOURLONG,
203 	       regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
204 	printk("           " FOURLONG,
205 	       regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
206 	printk("           " FOURLONG,
207 	       regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
208 
209 	show_code(regs);
210 }
211 
212 /* This is called from fs/proc/array.c */
213 char *task_show_regs(struct task_struct *task, char *buffer)
214 {
215 	struct pt_regs *regs;
216 
217 	regs = task_pt_regs(task);
218 	buffer += sprintf(buffer, "task: %p, ksp: %p\n",
219 		       task, (void *)task->thread.ksp);
220 	buffer += sprintf(buffer, "User PSW : %p %p\n",
221 		       (void *) regs->psw.mask, (void *)regs->psw.addr);
222 
223 	buffer += sprintf(buffer, "User GPRS: " FOURLONG,
224 			  regs->gprs[0], regs->gprs[1],
225 			  regs->gprs[2], regs->gprs[3]);
226 	buffer += sprintf(buffer, "           " FOURLONG,
227 			  regs->gprs[4], regs->gprs[5],
228 			  regs->gprs[6], regs->gprs[7]);
229 	buffer += sprintf(buffer, "           " FOURLONG,
230 			  regs->gprs[8], regs->gprs[9],
231 			  regs->gprs[10], regs->gprs[11]);
232 	buffer += sprintf(buffer, "           " FOURLONG,
233 			  regs->gprs[12], regs->gprs[13],
234 			  regs->gprs[14], regs->gprs[15]);
235 	buffer += sprintf(buffer, "User ACRS: %08x %08x %08x %08x\n",
236 			  task->thread.acrs[0], task->thread.acrs[1],
237 			  task->thread.acrs[2], task->thread.acrs[3]);
238 	buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
239 			  task->thread.acrs[4], task->thread.acrs[5],
240 			  task->thread.acrs[6], task->thread.acrs[7]);
241 	buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
242 			  task->thread.acrs[8], task->thread.acrs[9],
243 			  task->thread.acrs[10], task->thread.acrs[11]);
244 	buffer += sprintf(buffer, "           %08x %08x %08x %08x\n",
245 			  task->thread.acrs[12], task->thread.acrs[13],
246 			  task->thread.acrs[14], task->thread.acrs[15]);
247 	return buffer;
248 }
249 
250 static DEFINE_SPINLOCK(die_lock);
251 
252 void die(const char * str, struct pt_regs * regs, long err)
253 {
254 	static int die_counter;
255 
256 	debug_stop_all();
257 	console_verbose();
258 	spin_lock_irq(&die_lock);
259 	bust_spinlocks(1);
260 	printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
261         show_regs(regs);
262 	bust_spinlocks(0);
263         spin_unlock_irq(&die_lock);
264 	if (in_interrupt())
265 		panic("Fatal exception in interrupt");
266 	if (panic_on_oops)
267 		panic("Fatal exception: panic_on_oops");
268         do_exit(SIGSEGV);
269 }
270 
271 static void inline
272 report_user_fault(long interruption_code, struct pt_regs *regs)
273 {
274 #if defined(CONFIG_SYSCTL)
275 	if (!sysctl_userprocess_debug)
276 		return;
277 #endif
278 #if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG)
279 	printk("User process fault: interruption code 0x%lX\n",
280 	       interruption_code);
281 	show_regs(regs);
282 #endif
283 }
284 
285 int is_valid_bugaddr(unsigned long addr)
286 {
287 	return 1;
288 }
289 
290 static void __kprobes inline do_trap(long interruption_code, int signr,
291 					char *str, struct pt_regs *regs,
292 					siginfo_t *info)
293 {
294 	/*
295 	 * We got all needed information from the lowcore and can
296 	 * now safely switch on interrupts.
297 	 */
298         if (regs->psw.mask & PSW_MASK_PSTATE)
299 		local_irq_enable();
300 
301 	if (notify_die(DIE_TRAP, str, regs, interruption_code,
302 				interruption_code, signr) == NOTIFY_STOP)
303 		return;
304 
305         if (regs->psw.mask & PSW_MASK_PSTATE) {
306                 struct task_struct *tsk = current;
307 
308                 tsk->thread.trap_no = interruption_code & 0xffff;
309 		force_sig_info(signr, info, tsk);
310 		report_user_fault(interruption_code, regs);
311         } else {
312                 const struct exception_table_entry *fixup;
313                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
314                 if (fixup)
315                         regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE;
316 		else {
317 			enum bug_trap_type btt;
318 
319 			btt = report_bug(regs->psw.addr & PSW_ADDR_INSN);
320 			if (btt == BUG_TRAP_TYPE_WARN)
321 				return;
322 			die(str, regs, interruption_code);
323 		}
324         }
325 }
326 
327 static inline void __user *get_check_address(struct pt_regs *regs)
328 {
329 	return (void __user *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
330 }
331 
332 void __kprobes do_single_step(struct pt_regs *regs)
333 {
334 	if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0,
335 					SIGTRAP) == NOTIFY_STOP){
336 		return;
337 	}
338 	if ((current->ptrace & PT_PTRACED) != 0)
339 		force_sig(SIGTRAP, current);
340 }
341 
342 static void default_trap_handler(struct pt_regs * regs, long interruption_code)
343 {
344         if (regs->psw.mask & PSW_MASK_PSTATE) {
345 		local_irq_enable();
346 		do_exit(SIGSEGV);
347 		report_user_fault(interruption_code, regs);
348 	} else
349 		die("Unknown program exception", regs, interruption_code);
350 }
351 
352 #define DO_ERROR_INFO(signr, str, name, sicode, siaddr) \
353 static void name(struct pt_regs * regs, long interruption_code) \
354 { \
355         siginfo_t info; \
356         info.si_signo = signr; \
357         info.si_errno = 0; \
358         info.si_code = sicode; \
359 	info.si_addr = siaddr; \
360         do_trap(interruption_code, signr, str, regs, &info); \
361 }
362 
363 DO_ERROR_INFO(SIGILL, "addressing exception", addressing_exception,
364 	      ILL_ILLADR, get_check_address(regs))
365 DO_ERROR_INFO(SIGILL,  "execute exception", execute_exception,
366 	      ILL_ILLOPN, get_check_address(regs))
367 DO_ERROR_INFO(SIGFPE,  "fixpoint divide exception", divide_exception,
368 	      FPE_INTDIV, get_check_address(regs))
369 DO_ERROR_INFO(SIGFPE,  "fixpoint overflow exception", overflow_exception,
370 	      FPE_INTOVF, get_check_address(regs))
371 DO_ERROR_INFO(SIGFPE,  "HFP overflow exception", hfp_overflow_exception,
372 	      FPE_FLTOVF, get_check_address(regs))
373 DO_ERROR_INFO(SIGFPE,  "HFP underflow exception", hfp_underflow_exception,
374 	      FPE_FLTUND, get_check_address(regs))
375 DO_ERROR_INFO(SIGFPE,  "HFP significance exception", hfp_significance_exception,
376 	      FPE_FLTRES, get_check_address(regs))
377 DO_ERROR_INFO(SIGFPE,  "HFP divide exception", hfp_divide_exception,
378 	      FPE_FLTDIV, get_check_address(regs))
379 DO_ERROR_INFO(SIGFPE,  "HFP square root exception", hfp_sqrt_exception,
380 	      FPE_FLTINV, get_check_address(regs))
381 DO_ERROR_INFO(SIGILL,  "operand exception", operand_exception,
382 	      ILL_ILLOPN, get_check_address(regs))
383 DO_ERROR_INFO(SIGILL,  "privileged operation", privileged_op,
384 	      ILL_PRVOPC, get_check_address(regs))
385 DO_ERROR_INFO(SIGILL,  "special operation exception", special_op_exception,
386 	      ILL_ILLOPN, get_check_address(regs))
387 DO_ERROR_INFO(SIGILL,  "translation exception", translation_exception,
388 	      ILL_ILLOPN, get_check_address(regs))
389 
390 static inline void
391 do_fp_trap(struct pt_regs *regs, void __user *location,
392            int fpc, long interruption_code)
393 {
394 	siginfo_t si;
395 
396 	si.si_signo = SIGFPE;
397 	si.si_errno = 0;
398 	si.si_addr = location;
399 	si.si_code = 0;
400 	/* FPC[2] is Data Exception Code */
401 	if ((fpc & 0x00000300) == 0) {
402 		/* bits 6 and 7 of DXC are 0 iff IEEE exception */
403 		if (fpc & 0x8000) /* invalid fp operation */
404 			si.si_code = FPE_FLTINV;
405 		else if (fpc & 0x4000) /* div by 0 */
406 			si.si_code = FPE_FLTDIV;
407 		else if (fpc & 0x2000) /* overflow */
408 			si.si_code = FPE_FLTOVF;
409 		else if (fpc & 0x1000) /* underflow */
410 			si.si_code = FPE_FLTUND;
411 		else if (fpc & 0x0800) /* inexact */
412 			si.si_code = FPE_FLTRES;
413 	}
414 	current->thread.ieee_instruction_pointer = (addr_t) location;
415 	do_trap(interruption_code, SIGFPE,
416 		"floating point exception", regs, &si);
417 }
418 
419 static void illegal_op(struct pt_regs * regs, long interruption_code)
420 {
421 	siginfo_t info;
422         __u8 opcode[6];
423 	__u16 __user *location;
424 	int signal = 0;
425 
426 	location = get_check_address(regs);
427 
428 	/*
429 	 * We got all needed information from the lowcore and can
430 	 * now safely switch on interrupts.
431 	 */
432 	if (regs->psw.mask & PSW_MASK_PSTATE)
433 		local_irq_enable();
434 
435 	if (regs->psw.mask & PSW_MASK_PSTATE) {
436 		if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
437 			return;
438 		if (*((__u16 *) opcode) == S390_BREAKPOINT_U16) {
439 			if (current->ptrace & PT_PTRACED)
440 				force_sig(SIGTRAP, current);
441 			else
442 				signal = SIGILL;
443 #ifdef CONFIG_MATHEMU
444 		} else if (opcode[0] == 0xb3) {
445 			if (get_user(*((__u16 *) (opcode+2)), location+1))
446 				return;
447 			signal = math_emu_b3(opcode, regs);
448                 } else if (opcode[0] == 0xed) {
449 			if (get_user(*((__u32 *) (opcode+2)),
450 				     (__u32 __user *)(location+1)))
451 				return;
452 			signal = math_emu_ed(opcode, regs);
453 		} else if (*((__u16 *) opcode) == 0xb299) {
454 			if (get_user(*((__u16 *) (opcode+2)), location+1))
455 				return;
456 			signal = math_emu_srnm(opcode, regs);
457 		} else if (*((__u16 *) opcode) == 0xb29c) {
458 			if (get_user(*((__u16 *) (opcode+2)), location+1))
459 				return;
460 			signal = math_emu_stfpc(opcode, regs);
461 		} else if (*((__u16 *) opcode) == 0xb29d) {
462 			if (get_user(*((__u16 *) (opcode+2)), location+1))
463 				return;
464 			signal = math_emu_lfpc(opcode, regs);
465 #endif
466 		} else
467 			signal = SIGILL;
468 	} else {
469 		/*
470 		 * If we get an illegal op in kernel mode, send it through the
471 		 * kprobes notifier. If kprobes doesn't pick it up, SIGILL
472 		 */
473 		if (notify_die(DIE_BPT, "bpt", regs, interruption_code,
474 			       3, SIGTRAP) != NOTIFY_STOP)
475 			signal = SIGILL;
476 	}
477 
478 #ifdef CONFIG_MATHEMU
479         if (signal == SIGFPE)
480 		do_fp_trap(regs, location,
481                            current->thread.fp_regs.fpc, interruption_code);
482         else if (signal == SIGSEGV) {
483 		info.si_signo = signal;
484 		info.si_errno = 0;
485 		info.si_code = SEGV_MAPERR;
486 		info.si_addr = (void __user *) location;
487 		do_trap(interruption_code, signal,
488 			"user address fault", regs, &info);
489 	} else
490 #endif
491         if (signal) {
492 		info.si_signo = signal;
493 		info.si_errno = 0;
494 		info.si_code = ILL_ILLOPC;
495 		info.si_addr = (void __user *) location;
496 		do_trap(interruption_code, signal,
497 			"illegal operation", regs, &info);
498 	}
499 }
500 
501 
502 #ifdef CONFIG_MATHEMU
503 asmlinkage void
504 specification_exception(struct pt_regs * regs, long interruption_code)
505 {
506         __u8 opcode[6];
507 	__u16 __user *location = NULL;
508 	int signal = 0;
509 
510 	location = (__u16 __user *) get_check_address(regs);
511 
512 	/*
513 	 * We got all needed information from the lowcore and can
514 	 * now safely switch on interrupts.
515 	 */
516         if (regs->psw.mask & PSW_MASK_PSTATE)
517 		local_irq_enable();
518 
519         if (regs->psw.mask & PSW_MASK_PSTATE) {
520 		get_user(*((__u16 *) opcode), location);
521 		switch (opcode[0]) {
522 		case 0x28: /* LDR Rx,Ry   */
523 			signal = math_emu_ldr(opcode);
524 			break;
525 		case 0x38: /* LER Rx,Ry   */
526 			signal = math_emu_ler(opcode);
527 			break;
528 		case 0x60: /* STD R,D(X,B) */
529 			get_user(*((__u16 *) (opcode+2)), location+1);
530 			signal = math_emu_std(opcode, regs);
531 			break;
532 		case 0x68: /* LD R,D(X,B) */
533 			get_user(*((__u16 *) (opcode+2)), location+1);
534 			signal = math_emu_ld(opcode, regs);
535 			break;
536 		case 0x70: /* STE R,D(X,B) */
537 			get_user(*((__u16 *) (opcode+2)), location+1);
538 			signal = math_emu_ste(opcode, regs);
539 			break;
540 		case 0x78: /* LE R,D(X,B) */
541 			get_user(*((__u16 *) (opcode+2)), location+1);
542 			signal = math_emu_le(opcode, regs);
543 			break;
544 		default:
545 			signal = SIGILL;
546 			break;
547                 }
548         } else
549 		signal = SIGILL;
550 
551         if (signal == SIGFPE)
552 		do_fp_trap(regs, location,
553                            current->thread.fp_regs.fpc, interruption_code);
554         else if (signal) {
555 		siginfo_t info;
556 		info.si_signo = signal;
557 		info.si_errno = 0;
558 		info.si_code = ILL_ILLOPN;
559 		info.si_addr = location;
560 		do_trap(interruption_code, signal,
561 			"specification exception", regs, &info);
562 	}
563 }
564 #else
565 DO_ERROR_INFO(SIGILL, "specification exception", specification_exception,
566 	      ILL_ILLOPN, get_check_address(regs));
567 #endif
568 
569 static void data_exception(struct pt_regs * regs, long interruption_code)
570 {
571 	__u16 __user *location;
572 	int signal = 0;
573 
574 	location = get_check_address(regs);
575 
576 	/*
577 	 * We got all needed information from the lowcore and can
578 	 * now safely switch on interrupts.
579 	 */
580 	if (regs->psw.mask & PSW_MASK_PSTATE)
581 		local_irq_enable();
582 
583 	if (MACHINE_HAS_IEEE)
584 		asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
585 
586 #ifdef CONFIG_MATHEMU
587         else if (regs->psw.mask & PSW_MASK_PSTATE) {
588         	__u8 opcode[6];
589 		get_user(*((__u16 *) opcode), location);
590 		switch (opcode[0]) {
591 		case 0x28: /* LDR Rx,Ry   */
592 			signal = math_emu_ldr(opcode);
593 			break;
594 		case 0x38: /* LER Rx,Ry   */
595 			signal = math_emu_ler(opcode);
596 			break;
597 		case 0x60: /* STD R,D(X,B) */
598 			get_user(*((__u16 *) (opcode+2)), location+1);
599 			signal = math_emu_std(opcode, regs);
600 			break;
601 		case 0x68: /* LD R,D(X,B) */
602 			get_user(*((__u16 *) (opcode+2)), location+1);
603 			signal = math_emu_ld(opcode, regs);
604 			break;
605 		case 0x70: /* STE R,D(X,B) */
606 			get_user(*((__u16 *) (opcode+2)), location+1);
607 			signal = math_emu_ste(opcode, regs);
608 			break;
609 		case 0x78: /* LE R,D(X,B) */
610 			get_user(*((__u16 *) (opcode+2)), location+1);
611 			signal = math_emu_le(opcode, regs);
612 			break;
613 		case 0xb3:
614 			get_user(*((__u16 *) (opcode+2)), location+1);
615 			signal = math_emu_b3(opcode, regs);
616 			break;
617                 case 0xed:
618 			get_user(*((__u32 *) (opcode+2)),
619 				 (__u32 __user *)(location+1));
620 			signal = math_emu_ed(opcode, regs);
621 			break;
622 	        case 0xb2:
623 			if (opcode[1] == 0x99) {
624 				get_user(*((__u16 *) (opcode+2)), location+1);
625 				signal = math_emu_srnm(opcode, regs);
626 			} else if (opcode[1] == 0x9c) {
627 				get_user(*((__u16 *) (opcode+2)), location+1);
628 				signal = math_emu_stfpc(opcode, regs);
629 			} else if (opcode[1] == 0x9d) {
630 				get_user(*((__u16 *) (opcode+2)), location+1);
631 				signal = math_emu_lfpc(opcode, regs);
632 			} else
633 				signal = SIGILL;
634 			break;
635 		default:
636 			signal = SIGILL;
637 			break;
638                 }
639         }
640 #endif
641 	if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
642 		signal = SIGFPE;
643 	else
644 		signal = SIGILL;
645         if (signal == SIGFPE)
646 		do_fp_trap(regs, location,
647                            current->thread.fp_regs.fpc, interruption_code);
648         else if (signal) {
649 		siginfo_t info;
650 		info.si_signo = signal;
651 		info.si_errno = 0;
652 		info.si_code = ILL_ILLOPN;
653 		info.si_addr = location;
654 		do_trap(interruption_code, signal,
655 			"data exception", regs, &info);
656 	}
657 }
658 
659 static void space_switch_exception(struct pt_regs * regs, long int_code)
660 {
661         siginfo_t info;
662 
663 	/* Set user psw back to home space mode. */
664 	if (regs->psw.mask & PSW_MASK_PSTATE)
665 		regs->psw.mask |= PSW_ASC_HOME;
666 	/* Send SIGILL. */
667         info.si_signo = SIGILL;
668         info.si_errno = 0;
669         info.si_code = ILL_PRVOPC;
670         info.si_addr = get_check_address(regs);
671         do_trap(int_code, SIGILL, "space switch event", regs, &info);
672 }
673 
674 asmlinkage void kernel_stack_overflow(struct pt_regs * regs)
675 {
676 	bust_spinlocks(1);
677 	printk("Kernel stack overflow.\n");
678 	show_regs(regs);
679 	bust_spinlocks(0);
680 	panic("Corrupt kernel stack, can't continue.");
681 }
682 
683 /* init is done in lowcore.S and head.S */
684 
685 void __init trap_init(void)
686 {
687         int i;
688 
689         for (i = 0; i < 128; i++)
690           pgm_check_table[i] = &default_trap_handler;
691         pgm_check_table[1] = &illegal_op;
692         pgm_check_table[2] = &privileged_op;
693         pgm_check_table[3] = &execute_exception;
694         pgm_check_table[4] = &do_protection_exception;
695         pgm_check_table[5] = &addressing_exception;
696         pgm_check_table[6] = &specification_exception;
697         pgm_check_table[7] = &data_exception;
698         pgm_check_table[8] = &overflow_exception;
699         pgm_check_table[9] = &divide_exception;
700         pgm_check_table[0x0A] = &overflow_exception;
701         pgm_check_table[0x0B] = &divide_exception;
702         pgm_check_table[0x0C] = &hfp_overflow_exception;
703         pgm_check_table[0x0D] = &hfp_underflow_exception;
704         pgm_check_table[0x0E] = &hfp_significance_exception;
705         pgm_check_table[0x0F] = &hfp_divide_exception;
706         pgm_check_table[0x10] = &do_dat_exception;
707         pgm_check_table[0x11] = &do_dat_exception;
708         pgm_check_table[0x12] = &translation_exception;
709         pgm_check_table[0x13] = &special_op_exception;
710 #ifdef CONFIG_64BIT
711         pgm_check_table[0x38] = &do_dat_exception;
712 	pgm_check_table[0x39] = &do_dat_exception;
713 	pgm_check_table[0x3A] = &do_dat_exception;
714         pgm_check_table[0x3B] = &do_dat_exception;
715 #endif /* CONFIG_64BIT */
716         pgm_check_table[0x15] = &operand_exception;
717         pgm_check_table[0x1C] = &space_switch_exception;
718         pgm_check_table[0x1D] = &hfp_sqrt_exception;
719 	pgm_check_table[0x40] = &do_monitor_call;
720 	pfault_irq_init();
721 }
722